HYDROXY RESIN, STYRENE RESIN, METHOD FOR PRODUCING HYDROXY RESIN, METHOD FOR PRODUCING STYRENE RESIN, AND APPLICATIONS THEREOF

Abstract
Provided is a styrene resin, a hydroxy resin, a method for producing a hydroxy resin, a method for producing a styrene resin, a resin composition containing a styrene resin, a cured product, a prepreg, a metal foil-clad laminate, a resin composite sheet, a printed wiring board, and a semiconductor device. Provided is a hydroxy resin represented by Formula (T-OH) and having a number average molecular weight of 850 to 4000. In Formula (T-OH), R is a group containing structural units represented by Formula (Tx-OH).
Description
TECHNICAL FIELD

The present invention relates to a hydroxy resin, a styrene resin, a method for producing a hydroxy resin, a method for producing a styrene resin, a resin composition, a cured product, a prepreg, a metal foil-clad laminate, a resin composite sheet, a printed wiring board, and a semiconductor device.


BACKGROUND ART

In recent years, a trend for higher integration and finer configuration have been accelerated for semiconductor devices that are used in electronic devices and communication devices, including mobile terminals. Along with this trend, a technology that enables high-density mounting of semiconductor devices is required, and an improvement is also required for printed wiring boards, which hold an important role in the technology.


Meanwhile, applications of electronic devices are diversified and continuously expanding. Accordingly, properties required for printed wiring boards, and metal foil-clad laminates, prepregs, and the like used in the printed wiring boards have also been diversified, and the requirements have become more demanding. To obtain improved printed wiring boards in consideration of such requirements, various materials and processing methods have been proposed. One of these includes development to improve a resin material constituting a prepreg or a resin composite sheet.


For example, Patent Document 1 discloses a resin serving as such an electronic material.


CITATION LIST
Patent Document



  • Patent Document 1: JP 6-172242 A



SUMMARY OF INVENTION
Technical Problem

As described above, the hydroxy resin described in Patent Document 1 can be used as a raw material of an electronic material. However, as a result of examination by the present inventor, it has been found that when the styrene resin produced from the hydroxy resin described in Patent Document 1 is formed into a cured product, the cured product is inferior in low dielectric properties (Dk and/or Df).


The present invention aims to solve such problems, and an object of the present invention is to obtain a styrene resin capable of providing a cured product having excellent low dielectric properties (Dk and/or Df) and excellent thermal resistance. Furthermore, an object of the present invention is to provide a hydroxy resin as a raw material of a styrene resin, a method for producing the hydroxy resin, a method for producing the styrene resin, a resin composition containing the styrene resin, a cured product, a prepreg, a metal foil-clad laminate, a resin composite sheet, a printed wiring board, and a semiconductor device.


Solution to Problem

As described above, it has been found that when a styrene resin is produced from the hydroxy resin described in Patent Document 1, a cured product of the styrene resin is inferior in low dielectric properties (Dk and/or Df) and is difficult to use as an electronic material. As a result of examining the reason, the present inventor has inferred that the reason is that the hydroxy resin described in Patent Document 1 has a low molecular weight. Specifically, Patent Document 1 discloses a hydroxy resin in which the average number (n) of repeating units containing an indane skeleton is 2.3 in Examples of the document. This resin has a number average molecular weight of about 766. That is, the molecular weight is low, and the proportion of the indane skeleton in the resin is low. Thus, it has been presumed that the low dielectric properties (Dk and/or Df) of the cured product of the styrene resin produced using such a hydroxy resin are inferior.


In the present embodiment, as described below in detail, the low dielectric properties (Dk and/or Df) of the cured product to be produced can be further improved by removing an excessive styrene compound that reacts with the hydroxy resin.


Under such circumstances, the problems described above are solved by the following means.


<1> A hydroxy resin represented by Formula (T-OH) and having a number average molecular weight of 850 to 4000:




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(in Formula (T-OH), R is a group containing structural units represented by Formula (Tx-OH); Arm is each independently a benzene ring, a naphthalene ring, or an anthracene ring; Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; Mb each independently represents a hydroxyl group, a halogen atom, or a hydrocarbon group having from 1 to 20 carbons which may be substituted with a hydroxyl group or a halogen atom; and x and y each independently represent an integer of 0 to 4)




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(in Formula (Tx-OH), n, o, and p each represent an average number of repeating units; n represents a number of more than 0 and 20 or less; o and p each independently represent a number of 0 to 20; 1.0≤n+o+p≤20.0; Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; x represents an integer of 0 to 4; structural units (a), (b), and (c) are each bonded to the structural unit (a), (b), or (c), or an additional group by *; and the structural units may be randomly bonded).


<2> The hydroxy resin according to <1>, wherein the number average molecular weight is 900 to 2500.


<3> The hydroxy resin according to <1> or <2>, wherein Formula (T-OH) is represented by Formula (T-OH2):




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(in Formula (T-OH2), R is a group containing structural units represented by Formula (Tx-OH); Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; Mb each independently represents a hydroxyl group, a halogen atom, or a hydrocarbon group having from 1 to 20 carbons which may be substituted with a hydroxyl group or a halogen atom; and x and y each independently represent an integer of 0 to 4)




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(in Formula (Tx-OH), n, o, and p each represent an average number of repeating units; n represents a number of more than 0 and 20 or less, o and p each independently represent a number of 0 to 20; 1.0≤n+o+p≤520.0; Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; x represents an integer of 0 to 4; structural units (a), (b), and (c) are each bonded to the structural unit (a), (b), or (c), or an additional group by *; and the structural units may be randomly bonded).


<4> A styrene resin represented by Formula (T-St) and having a number average molecular weight of 1050 to 4000:




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(in Formula (T-St), R is a group containing structural units represented by Formula (Tx-St); Arm is each independently a benzene ring, a naphthalene ring, or an anthracene ring; Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; Mb each independently represents a hydroxyl group, a halogen atom, or a hydrocarbon group having from 1 to 20 carbons which may be substituted with a hydroxyl group or a halogen atom; Mc each independently represents a hydrocarbon group having from 1 to 12 carbons; x, y, and z each independently represent an integer of 0 to 4; r represents an integer of 1 to 6; and R1, R2, and R3 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group)




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(in Formula (Tx-St), n, o, and p each represent an average number of repeating units; n represents a number of more than 0 and 20 or less; o and p each independently represent a number of 0 to 20; 1.0≤n+o+p≤20.0; Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; x represents an integer of 0 to 4; structural units (a), (b), and (c) are each bonded to the structural unit (a), (b), or (c), or an additional group by *; and the structural units may be randomly bonded).


<5> The styrene resin according to <4>, wherein Formula (T-St) is represented by Formula (T-St2):




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(in Formula (T-St2), R is a group containing structural units represented by Formula (Tx-St); Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; Mb each independently represents a hydroxyl group, a halogen atom, or a hydrocarbon group having from 1 to 20 carbons which may be substituted with a hydroxyl group or a halogen atom; Mc each independently represents a hydrocarbon group having from 1 to 12 carbons; x, y, and z each independently represent an integer of 0 to 4; r represents an integer of 1 to 6; and R1, R2, and R3 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group)




embedded image


(in Formula (Tx-St), n, o, and p each represent an average number of repeating units; n represents a number of more than 0 and 20 or less; o and p each independently represent a number of 0 to 20; 1.0≤n+o+p≤20.0; Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; x represents an integer of 0 to 4; structural units are each bonded to the structural unit (a), (b), or (c), or an additional group; and the structural units may be randomly bonded).


<6> The styrene resin according to <4> or <5>, wherein the number average molecular weight is 1050 to 2500.


<7> The styrene resin according to any one of <4> to <6>, wherein a sum of a total chlorine amount and a total bromine amount is 2500 ppm by mass or less.


<8> The styrene resin according to any one of <4> to <7>, wherein a cured product of the styrene resin has a dielectric loss tangent of 0.0030 or less at a frequency of 10 GHz.


<9′> A method for producing the hydroxy resin described in any one of <1> to <3>, the method including using a resin (T), wherein the resin (T) is a resin represented by Formula (T):




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(in Formula (T), R is a group containing structural units represented by Formula (Tx); Ma represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; and x represents an integer of 0 to 4




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(in Formula (Tx), n, o, and p each represent an average number of repeating units; n represents a number of more than 0 and 20 or less; o and p each independently represent a number of 0 to 20; 1.0≤n+o+p≤20.0; Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; x represents an integer of 0 to 4; structural units are each bonded to the structural unit (a), (b), or (c), or an additional group; and the structural units may be randomly bonded).


<10> The method for producing the hydroxy resin according to <9>, the method including reacting the resin (T) with compound represented by Formula (P):




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(in Formula (P), Arm is each independently a benzene ring, a naphthalene ring, or an anthracene ring; Mb each independently represents a hydroxyl group, a halogen atom, or a hydrocarbon group having from 1 to 20 carbons which may be substituted with a hydroxyl group or a halogen atom; and y represents an integer of 0 to 4).


<11> The method for producing the hydroxy resin according to <10>, wherein the compound represented by Formula (P) contains a compound represented by Formula (P1):




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(in Formula (P1), Mb each independently represents a hydroxyl group, a halogen atom, or a hydrocarbon group having from 1 to 20 carbons which may be substituted with a hydroxyl group or a halogen atom; and y represents an integer of 0 to 4).


<12> The method for producing the hydroxy resin according to <10> or <11>, wherein, in a reaction system for reacting the resin (T) with a compound represented by Formula (P), a total content of m-bis(α-hydroxyisopropyl)benzene, p-bis(α-hydroxyisopropyl)benzene, 1,3-diisopropenylbenzene, and 1,4-diisopropenylbenzene is 10 mass % or less relative to an amount of the resin (T).


<13> A method for producing the styrene resin described in any one of <4> to <8>, the method including using the hydroxy resin described in any one of <1> to <3>.


<14> The method for producing the styrene resin according to <13>, the method including reacting the hydroxy resin with a compound represented by Formula (S):




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(in Formula (S), Hr represents a chlorine atom or a bromine atom; Mc represents a hydrocarbon group having from 1 to 12 carbons; z represents an integer of 0 to 4; r represents an integer of 1 to 6; and R1, R2, and R3 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group).


<15> A resin composition containing the styrene resin described in any one of <4> to <8>.


<16> A cured product of the resin composition described in <15>.


<17> A prepreg formed from a substrate and the resin composition described in <15>.


<18> A metal foil-clad laminate including at least one layer formed from the prepreg described in <17>; and a metal foil disposed on one surface or both surfaces of the layer formed from the prepreg.


<19> A resin composite sheet including a support and a layer disposed on a surface of the support, the layer being formed from the resin composition described in <15>.


<20> A printed wiring board including an insulating layer and a conductor layer disposed on a surface of the insulating layer, wherein the insulating layer includes at least one of a layer formed from the resin composition described in <15> and a layer formed from the prepreg described in <17>.


<21> A semiconductor device including the printed wiring board described in <20>.


Advantageous Effects of Invention

According to the present invention, there can be produced a styrene resin capable of providing a cured product having excellent low dielectric properties (Dk and/or Df) and excellent thermal resistance. Furthermore, according to the present invention, there can be provided a hydroxy resin as a raw material of a styrene resin, a method for producing the hydroxy resin, a method for producing the styrene resin, a resin composition containing the styrene resin, a cured product, a prepreg, a metal foil-clad laminate, a resin composite sheet, a printed wiring board, and a semiconductor device.





BRIEF DESCRIPTION OF DRAWINGS


FIG. 1 illustrates an NMR chart of a hydroxy resin (C) synthesized in Example 3.



FIG. 2 illustrates an NMR chart of the styrene resin (C) synthesized in Example 3.



FIG. 3 illustrates a GPC chart of the styrene resin (C) synthesized in Example 3.





DESCRIPTION OF EMBODIMENTS

Embodiments for carrying out the present invention (hereinafter referred to simply as “the present embodiment”) will next be described in detail. The present embodiment described below is an example for describing the present invention, and the present invention is not limited only to the present embodiment.


In the present specification, numerical values described before and after the term “to” are respectively the lower limit and the upper limit of a range including the numerical values.


In the present specification, various physical property values and characteristic values are those at 23° C. unless otherwise noted.


In a description of a group (atomic group) in the present specification, a description not specifying whether the group is a substituted group or an unsubstituted group is meant to include a group (atomic group) having a substituent as well as a group (atomic group) having no substituent. For example, an “alkyl group” includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group). In the present specification, a description not specifying whether the group is a substituted group or an unsubstituted group means that the group is preferably an unsubstituted group.


In the present specification, a (meth)allyl group represents both or either of allyl and methallyl, a “(meth)acrylate” represents both or either of acrylate and methacrylate, a “(meth)acryl” represents both or either of acryl and methacryl, and a “(meth)acryloyl” represents both or either of acryloyl and methacryloyl.


The term “step” in the present specification includes not only an independent step, but also a case in which the desired action of a step is achieved, though the step cannot be clearly differentiated from another step.


When a measurement method described in a standard set forth in the present specification differs depending on the year, it is based on the standard as of Jan. 1, 2022 unless otherwise stated.


In the present specification, the resin solid content refers to components excluding a filler and a solvent, and is intended to include a styrene resin, and an additional thermosetting compound and another resin additive component (an additive such as a flame retardant) which are blended as necessary.


In this specification, the relative dielectric constant and the dielectric constant have the same meaning.


Hydroxy Resin

The hydroxy resin of the present embodiment is characterized by being represented by Formula (T-OH) and having a number average molecular weight of 850 to 4000.




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(In Formula (T-OH), R is a group containing structural units represented by Formula (Ix-OH); Arm is each independently a benzene ring, a naphthalene ring, or an anthracene ring; Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; Mb each independently represents a hydroxyl group, a halogen atom, or a hydrocarbon group having from 1 to 20 carbons which may be substituted with a hydroxyl group or a halogen atom; and x and y each independently represent an integer of 0 to 4.)




embedded image


(in Formula (Tx-OH), n, o, and p each represent an average number of repeating units; n represents a number of more than 0 and 20 or less; o and p each independently represent a number of 0 to 20; 1.0≤n+o+p≤20.0; Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; x represents an integer of 0 to 4; structural units are each bonded to the structural unit (a), (b), or (c), or an additional group; and the structural units may be randomly bonded.)


In Formula (T-OH), R is a group containing structural units represented by Formula (Tx-OH).


In Formula (Tx-OH), n, o, and p each mean the average number of repeating units in all molecules in the resin.


In Formula (Tx-OH), the sum of n, o, and p is preferably 1.1≤n+o+p, more preferably 1.2≤n+o+p, still more preferably 1.5≤n+o+p, even more preferably 2.0≤n+o+p, further more preferably 2.5≤n+o+p, still further more preferably 3.0≤n+o+p, and particularly preferably 3.3≤n+o+p, and much more preferably 3.5≤n+o+p, 3.7≤n+o+p, 4.0≤n+o+p, and 4.2≤n+o+p in this order. In Formula (Tx-OH), the sum of n, o, and p is also preferably n+o+p≤20.0, more preferably n+o+p≤10.0, still more preferably n+o+p≤8.0, even more preferably n+o+p≤7.0, further more preferably n+o+p<6.8, and still further more preferably n+o+p≤6.5. The sum of n, o, and p can be calculated by the method described in Examples below.


In Formula (Tx-OH), Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom, and is each independently preferably a hydrocarbon group having from 1 to 10 carbons which may be substituted with a halogen atom, more preferably a hydrocarbon group having from 1 to 5 carbons which may be substituted with a halogen atom, and still more preferably a hydrocarbon group having from 1 to 3 carbons which may be substituted with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom, and a fluorine atom or a chlorine atom is preferred. Ma is each independently preferably a hydrocarbon group having from 1 to 12 carbons which is not substituted with a halogen atom. The hydrocarbon group is preferably an alkyl group, and more preferably a linear alkyl group.


Ma is particularly preferably a methyl group or an ethyl group.


In Formula (Tx-OH), x represents an integer of 0 to 4, and is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, still more preferably 0 or 1, and even more preferably 0.


In Formula (T-OH), Arm is each independently a benzene ring, a naphthalene ring, or an anthracene ring, and is preferably a benzene ring or a naphthalene ring, and more preferably a benzene ring.


When Arm is a benzene ring and y is an integer of 1 to 4, it is preferable that an OH group bonded to Arm and Mb are bonded to each other at one or two of an ortho-position and a para-position (preferably at least one or two ortho-positions).


In Formula (T-OH), Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom, and has the same meaning as Ma in Formula (Tx-OH), and a preferred range is also the same.


In Formula (T-OH), Mb each independently represents a hydroxyl group, a halogen atom, or a hydrocarbon group having from 1 to 20 carbons which may be substituted with a hydroxyl group or a halogen atom, and is preferably a hydroxyl group, a halogen atom, or a hydrocarbon group having from 1 to 20 carbons which may be substituted with a halogen atom, and more preferably a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a linear or branched alkyl group having from 1 to 10 carbons, an alicyclic alkyl group having from 4 to 8 carbons, a cumyl group, a phenyl group, or a benzyl group. The halogen atom is preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, and more preferably a fluorine atom or a chlorine atom. The linear or branched alkyl group having from 1 to 10 carbons is preferably a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a t-butyl group, a pentyl group, an octyl group, or a nonyl group. The alicyclic alkyl group having from 4 to 8 carbons is preferably a cyclohexyl group. In the present embodiment, Mb is more preferably a hydroxyl group, a linear or branched alkyl group having from 1 to 10 carbons, or a benzyl group, and still more preferably a hydroxyl group, a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a t-butyl group, or a benzyl group.


In Formula (T-OH), x independently represents an integer of 0 to 4 and has the same meaning as x in Formula (Tx-OH), and a preferred range is also the same.


In Formula (T-OH), y each independently represents an integer of 0 to 4, and is preferably an integer of 0 to 3 and more preferably an integer of 0 to 2.


Formula (T-OH) is preferably represented by Formula (T-OH2).




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(in Formula (T-OH12), R is a group containing structural units represented by Formula (Tx-OH); Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; Mb each independently represents a hydroxyl group, a halogen atom, or a hydrocarbon group having from 1 to 20 carbons which may be substituted with a hydroxyl group or a halogen atom; and x and y each independently represent an integer of 0 to 4.)




embedded image


(In Formula (Tx-OH), n, o, and p each represent an average number of repeating units; n represents a number of more than 0 and 20 or less; o and p each independently represent a number of 0 to 20; 1.0≤n+o+p≤20.0; Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; x represents an integer of 0 to 4; structural units are each bonded to the structural unit (a), (b), or (c), or an additional group, and the structural units may be randomly bonded.)


In Formula (T-OH2), R, Ma, Mb, x, and y have the same meanings as R, Ma, Mb, x, and y in Formula (T-OH), respectively, and a preferred range is also the same.


In Formula (T-OH2), when y is an integer of 1 to 4, it is preferable that an OH group bonded to a benzene ring and Mb are bonded to each other at one or two of an ortho-position and a para-position (preferably at least one or two ortho-positions).


In addition, the hydroxy resin of the present embodiment preferably has a parameter α of 0.55 or more and 1.00 or less as calculated from Formula (α).










Parameter


α

=


(


2.55

ppm



2.31

ppm


)






(


6.24

ppm



5.91

ppm


)

+


(


2.98

ppm



2.55

ppm


)

/







2
+

(


2.55

ppm



2.31

ppm


)










α
)







(Each of the values in parentheses in Formula (α) indicates an integral value between the corresponding chemical shift values in 1H-NMR.)


Here, α represents the proportion of a structural unit having an indane skeleton (the structural unit (a) in Formula (Tx-OH)). More specifically, it is presumed that when the proportion of the structural unit having an indane skeleton is adjusted so as to satisfy the range of the parameter α, the rigidity of the resulting resin molecule can be enhanced, and the glass transition temperature of a cured product can be increased. More specifically, the parameter α in the hydroxy resin of the present embodiment can be increased by adjusting the parameter α in the resin (T) described below and reacting the compound represented by Formula (P) with the resin (T) in which the parameter α is adjusted to fall within a predetermined range. In the present embodiment, the proportion of the structural unit (a) in Formula (Tx-OH) can be further increased during the addition reaction of the compound represented by Formula (P).


The parameter α in the hydroxy resin is preferably 0.57 or more, more preferably 0.59 or more, still more preferably 0.60 or more, even more preferably 0.62 or more, and may be 0.63 or more, 0.65 or more, 0.70 or more, 0.75 or more, or 0.80 or more. When the parameter α is equal to or higher than the above lower limit, the low dielectric properties (low relative dielectric constant and/or low dielectric loss tangent) and the thermal resistance tend to be further improved when a hydroxy group is converted into a styrene group. Practically, the parameter α is preferably large from the viewpoint that the low dielectric properties and the thermal resistance tend to be excellent. However the parameter α may be 0.95 or less, 0.94 or less, 0.93 or less, 0.91 or less, or 0.90 or less.


The hydroxy resin of the present embodiment has a number average molecular weight of 850 to 4000. When the number average molecular weight is equal to or higher than the above lower limit, the low dielectric properties (Dk and/or Df, especially low dielectric loss tangent) tend to be further improved when a hydroxy group is converted into a styrene group. When the number average molecular weight is equal to or lower than the above upper limit, solvent solubility tends to further improved, and the moldability and solvent solubility tend to be further improved when a hydroxy group is converted into a styrene group.


The number average molecular weight of the hydroxy resin is preferably 900 or more, more preferably 950 or more, still more preferably 1000 or more, and even more preferably 1050 or more, and may be 1100 or more, 1150 or more, 1200 or more, 1250 or more, or 1300 or more. The number average molecular weight of the hydroxy resin is preferably 4000 or less, more preferably 3000 or less, still more preferably 2700 or less, even more preferably 2500 or less, further more preferably 2300 or less, 2200 or less, 2100 or less, and much more preferably 2000 or less, 1900 or less, and 1800 or less in this order, and the number average molecular weight may be 1700 or less, 1600 or less, or 1500 or less.


The weight average molecular weight of the hydroxy resin of the present embodiment is preferably 1000 or more, more preferably 1100 or more, still more preferably 1200 or more, even more preferably 1350 or more, further more preferably 1450 or more, and still further more preferably 1500 or more, and may be 1550 or more, 1600 or more, 1650 or more, 1700 or more, 1750 or more, or 1800 or more. When the weight average molecular weight is equal to or higher than the above lower limit, the low dielectric properties (Dk and/or Df, especially low dielectric loss tangent) tend to be further improved when a hydroxy group is converted into a styrene group. The weight average molecular weight of the hydroxy resin is preferably 5000 or less, more preferably 4000 or less, still preferably 3000 or less, even more preferably 2500 or less, further more preferably 2400 or less, and still further more preferably 2300 or less. When the weight average molecular weight is equal to or lower than the above upper limit, the solvent solubility tends to further improved, and the moldability and solvent solubility tend to be further improved when a hydroxy group is converted into a styrene group.


The dispersity (Mw/Mn) of the hydroxy resin of the present embodiment is preferably 1.20 or more, more preferably 1.22 or more, still more preferably 1.25 or more, even more preferably 1.30 or more, and further more preferably 1.32 or more. The dispersity (Mw/Mn) of the hydroxy resin is preferably 2.00 or less, more preferably 1.90 or less, still more preferably 1.80 or less, even more preferably 1.70 or less, and further more preferably 1.60 or less.


The hydroxyl group equivalent of the hydroxy resin of the present embodiment is preferably 365 g/eq. or more, more preferably 400 g/eq. or more, still more preferably 450 g/eq. or more, even more preferably 500 g/eq. or more, and further more preferably 550 g/eq. or more, and much more preferably 570 g/eq. or more, 600 g/eq. or more, 650 g/eq. or more, 660 g/eq. or more, 670 g/eq. or more, 680 g/eq. or more, 700 g/eq. or more, 750 g/eq. or more, and 800 g/eq. or more in this order. When the hydroxyl group equivalent is equal to or higher than the above lower limit, the relative dielectric constant (Dk) and the dielectric loss tangent (Df) tend to be further decreased when a hydroxy group is converted into a styrene group. The hydroxyl group equivalent of the hydroxy resin is preferably 2000 g/eq. or less, more preferably 1500 g/eq. or less, still more preferably 1400 g/eq. or less, even more preferably 1200 g/eq. or less, and further more preferably 1000 g/eq. or less, and may be 900 g/eq. or less. When the hydroxyl group equivalent is equal to or lower than the above upper limit, the solvent solubility tends to be further improved, and the moldability and solvent solubility tend to be further improved when a hydroxy group is converted into a styrene group.


The hydroxyl group equivalent of the hydroxy resin of the present embodiment is measured according to the method described in Examples below.


Styrene Resin

The styrene resin of the present embodiment is represented by Formula (T-St) and has a number average molecular weight of 1050 to 4000.




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(In Formula (T-St), R is a group containing structural units represented by Formula (Tx-St); Arm is each independently a benzene ring, a naphthalene ring, or an anthracene ring; Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; Mb each independently represents a hydroxyl group, a halogen atom, or a hydrocarbon group having from 1 to 20 carbons which may be substituted with a hydroxyl group or a halogen atom; Mc each independently represents a hydrocarbon group having from 1 to 12 carbons; x, y, and z each independently represent an integer of 0 to 4; r represents an integer of 1 to 6; and R1, R2, and R3 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group.)




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(In Formula (Tx-St), n, o, and p each represent an average number of repeating units; n P represents a number of more than 0 and 20 or less; o and p each independently represent a number of 0 to 20; 1.0≤n+o+p<20.0; Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; x represents an integer of 0 to 4; structural units are each bonded to the structural unit (a), (b), or (c), or an additional group; and the structural units may be randomly bonded.)


In Formula (T-St), R is a group containing structural units represented by Formula (Tx-St).


In Formula (Tx-St), n, o, and p each mean the average number of repeating units in all molecules in the resin.


In Formula (Tx-St), the sum of n, o, and p is preferably 1.1≤n+o+p, more preferably 1.2≤n+o+p, still more preferably 1.5≤n+o+p, even more preferably 2.0≤n+o+p, further more preferably 2.5≤n+o+p, still further more preferably 3.0≤n+o+p, and particularly preferably 3.3≤n+o+p, and much more preferably 3.5≤n+o+p, 3.7≤n+o+p, 4.0≤n+o+p, and 4.2≤n+o+p in this order. In Formula (Tx-St), the sum of n, o, and p is preferably n+o+p, 20.0, more preferably n+o+p<10.0, still more preferably n+o+p<8.0, even more preferably n+o+p≤7.0, further more preferably n+o+p≤6.5, and still further more preferably n+o+p≤6.4. The sum of n, o, and p can be calculated by the method described in Examples below. In Formula (Tx-St), the sum of n, o, and p is usually the same as the sum of n, o, and p in Formula (Tx).


In Formula (Tx-St), Ma and x have the same meanings as Ma and x in Formula (Tx-OH), respectively, and preferred ranges thereof are also the same.


In Formula (T-St), Arm is each independently a benzene ring, a naphthalene ring, or an anthracene ring, and has the same meaning as Arm in Formula (T-OH)), and a preferred range is also the same.


In Formula (T-St), Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom, and has the same meaning as Ma in Formula (Tx-St), and a preferred range is also the same.


In Formula (T-St), Mb each independently represents a hydroxyl group, a halogen atom, or a hydrocarbon group having from 1 to 20 carbons which may be substituted with a hydroxyl group or a halogen atom, and has the same meaning as Mb in Formula (T-OH), and a preferred range is also the same.


In Formula (T-St), Mc each independently represents a hydrocarbon group having from 1 to 12 carbons, and is preferably a hydrocarbon group having from 1 to 10 carbons, more preferably a linear or branched alkyl group having from 1 to 10 carbons, still more preferably a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a t-butyl group, a pentyl group, an octyl group, or a nonyl group, and even more preferably a methyl group, an ethyl group, an isopropyl group, an isobutyl group, or a t-butyl group.


In Formula (T-St), x and y have the same meanings as x and y in Formula (T-OH), and preferred ranges thereof are also the same.


In Formula (T-St), z each independently represents an integer of 0 to 4, and is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, still more preferably 0 or 1, and even more preferably 0.


In Formula (T-St), r represents an integer of 1 to 6, and is preferably an integer of 1 to 5, more preferably an integer of 1 to 4, still more preferably an integer of 1 to 3, even more preferably 1 or 2, and further more preferably 1.


In Formula (T-St), R3, R2, and R3 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group, and are each preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a methyl group, and still more preferably a hydrogen atom. The number of carbons of the alkyl group, the alkenyl group, or the alkynyl group as R1, R2, or R3 is preferably 5 or less, and more preferably 3 or less.


In the present embodiment. Formula (T-St) is preferably represented by Formula (T-St2).




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(In Formula (T-St2), R is a group containing structural units represented by Formula (Tx-St); Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; Mb each independently represents a hydroxyl group, a halogen atom, or a hydrocarbon group having from 1 to 20 carbons which may be substituted with a hydroxyl group or a halogen atom; Mc each independently represents a hydrocarbon group having from 1 to 12 carbons; x, y, and z each independently represent an integer of 0 to 4; r represents an integer of 1 to 6; and R1, R2, and R; each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group.)




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(in Formula (Tx-St), n, o, and p each represent an average number of repeating units; n represents a number of more than 0 and 20 or less; o and p each independently represent a number of 0 to 20; 1.0≤n+o+p≤20.0; Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; x represents an integer of 0 to 4; structural units are each bonded to the structural unit (a), (b), or (c), or an additional group; and the structural units may be randomly bonded.)


In Formula (T-St2), R, Ma, Mb, Mc, x, y, z, r, R1, R2, and R3 have the same meanings as R, Ma, Mb, Mc, x, y, z, r, R1, R2, and R; in Formula (T-St), respectively, and preferred ranges thereof are also the same.


The styrene resin of the present embodiment preferably has a parameter α of 0.55 or more and 1.00 or less as calculated from Formula (α).










Parameter


α

=


(


2.55

ppm



2.31

ppm


)






(


6.24

ppm



5.91

ppm


)

+


(


2.98

ppm



2.55

ppm


)

/







2
+

(


2.55

ppm



2.31

ppm


)










(
α
)







(Each of the values in parentheses in Formula (α) indicates an integral value between the corresponding chemical shift values in 1H-NMR.)


Here, α represents the proportion of a structural unit having an indane skeleton (the structural unit (a) in Formula (Tx-St)). More specifically, it is presumed that when the proportion of the structural unit having an indane skeleton is adjusted so as to satisfy the range of the parameter α, the rigidity of the resulting resin molecule can be enhanced, and the glass transition temperature of a cured product can be increased. More specifically, it is preferable to react a compound represented by Formula (S) with a hydroxy resin obtained by reacting a compound represented by Formula (P) with the resin (T) having the parameter α adjusted to a predetermined range by adjusting the parameter α in the resin (T) as described below.


The parameter α in the styrene resin is preferably 0.57 or more, more preferably 0.59 or more, still more preferably 0.60 or more, even more preferably 0.62 or more, and may be 0.65 or more, 0.70 or more, 0.75 or more, or 0.80 or more. When the parameter α is equal to or higher than the above lower limit, the low dielectric properties (low relative dielectric constant and/or low dielectric loss tangent) and the thermal resistance of the resulting cured product tend to be further improved. Practically, the parameter α is preferably large from the viewpoint that the low dielectric properties and the thermal resistance of the resulting cured product tend to be excellent. However, the parameter α may be 0.95 or less, 0.94 or less, 0.93 or less, or 0.92 or less.


The styrene resin of the present embodiment has a number average molecular weight of 1050 to 4000. When the number average molecular weight is equal to or higher than the above lower limit, the low dielectric properties (Dk and/or Df, especially low dielectric loss tangent) of the resulting cured product tend to be further improved. It is considered that an increase in molecular weight causes an increase in the proportion of the indane skeleton (structural unit (a) in Formula (Tx-St)) in the molecule. When the number average molecular weight is equal to or lower than the above upper limit, the moldability and the solvent solubility tend to be further improved. The number average molecular weight of the styrene resin is preferably 1100 or more, more preferably 1150 or more, still more preferably 1200 or more, even more preferably 1250 or more, and further more preferably 1280 or more, and may be 1300 or more, 1400 or more, 1500 or more, 1550 or more, or 1590 or more. The number average molecular weight of the styrene resin is preferably 3000 or less, more preferably 2500 or less, still more preferably 2000 or less, even more preferably 1800 or less, and further more preferably 1700 or less.


The styrene resin of the present embodiment preferably has a weight average molecular weight of 1200 or more, more preferably 1250 or more, still more preferably 1300 or more, and even more preferably 1400 or more, and much more preferably 1500 or more, 1550 or more, 1600 or more, 1650 or more, 1700 or more, 1750 or more, 1790 or more, 1810 or more, 2050 or more, and 2250 or more in this order. When the weight average molecular weight is equal to or higher than the above lower limit, the low dielectric properties (Dk and/or Df, especially low dielectric loss tangent) of the resulting cured product tend to be further improved. The weight average molecular weight of the styrene resin is preferably 5000 or less, more preferably 4000 or less, still more preferably 3000 or less, even more preferably 2800 or less, and further more preferably 2500 or less. When the weight average molecular weight is equal to or lower than the above upper limit, the moldability and the solvent solubility tend to be further improved.


The dispersity (Mw/Mn) of the styrene resin used in the present embodiment is preferably 1.18 or more, more preferably 1.20 or more, still more preferably 1.25 or more, even more preferably 1.30 or more, and further more preferably 1.32 or more, and may be 1.34 or more. The dispersity (Mw/Mn) of the styrene resin is preferably 2.00 or less, more preferably 1.85 or less, still more preferably 1.70 or less, even more preferably 1.60 or less, and further more preferably 1.50 or less.


In the present embodiment, the total amount of chlorine and bromine in the styrene resin is small. Since the carbon atom, the chlorine atom, and the bromine atom are strongly polarized, the polarization in the molecule can be suppressed by reducing the number of molecules having these halogen atoms, so that the low dielectric properties (Dk and/or Df) of the resulting cured product can be achieved, and the low dielectric properties can be further improved. When a large amount of a compound containing hydrolyzable chlorine and bromine is contained in the resin, the compound is hydrolyzed at the time of moisture absorption to liberate chlorine ions and bromine ions, and migration characteristics tend to deteriorate. However, the migration characteristics can be improved by reducing molecules having these halogen atoms.


From the above viewpoint, more specifically, the sum of a total chlorine amount and a total bromine amount in the styrene resin is preferably 2500 ppm by mass or less, more preferably 2000 ppm by muss or less, still more preferably 1500 ppm by mass or less, even more preferably 1000 ppm by mass or less, further more preferably 500 ppm by mass or less, still further more preferably 450 ppm by mass or less, and particularly preferably 400 ppm by mass or less. The lower limit of the sum of the total chlorine amount and the total bromine amount in the styrene resin is ideally 0 ppm by mass, and is practically 10 ppm by mass or more. Even when the lower limit is 100 ppm by mass or more, required performance is satisfied.


In particular, in the present embodiment, the chlorine amount in the styrene resin is preferably 2500 ppm by mass or less, more preferably 2000 ppm by mass or less, still more preferably 1500 ppm by mass or less, even more preferably 1000 ppm by mass or less, further more preferably 500 ppm by mass or less, and particularly preferably 400 ppm by mass or less. The lower limit of the chlorine amount in the styrene resin is ideally 0 ppm by mass, and is practically 10 ppm by mass or more, and even when the lower limit is 100 ppm by mass or more, required performance is satisfied.


Such a styrene resin having few chlorine atoms and bromine atoms is achieved, for example, by removing a low molecular weight compound (compound having a molecular weight of 400 or less) containing a chlorine atom and/or a bromine atom, particularly, a compound represented by Formula (S) and impurities of the compound represented by Formula (S) in the styrene resin production method described below.


Examples of the impurity of the compound represented by Formula (S) include those in which an α carbon or a β carbon of the compound represented by Formula (S) is substituted with a chlorine atom or a bromine atom, and a dichloro-substituted product or dibromo-substituted product of the compound represented by Formula (S). More specific examples include compounds described below.




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The styrene resin of the present embodiment has a hydroxyl group equivalent of preferably 13000 g/eq. or more, more preferably 15000 g/eq. or more, still more preferably 20000 g/eq. or more, even more preferably 30000 g/eq. or more, further more preferably 35000 g/eq. or more, still further more preferably 40000 g/eq., even further more preferably 60000 g/eq. or more, and particularly preferably 80000 g/eq. or more. When the hydroxyl equivalent is equal to or higher than the above lower limit, the relative dielectric constant (Dk) and the dielectric loss tangent (Df) tend to be decreased. The upper limit of the hydroxyl group equivalent is not particularly limited, and is practically 100000 g/eq. or less, for example.


The hydroxyl group equivalent in the styrene resin is measured according to the description in Examples below.


When the styrene resin of the present embodiment is formed into a cured product, the cured product has a low dielectric loss tangent. Specifically, the dielectric loss tangent of the cured product of the styrene resin of the present embodiment at a frequency of 10 GHz is preferably 0.0030 or less, more preferably 0.0028 or less, still more preferably 0.0025 or less, even more preferably 0.0023 or less, and even more preferably 0.0021 or less, and may be 0.0019 or less, 0.0018 or less, 0.0017 or less, 0.0016 or less, or 0.0015 or less. The lower limit of the dielectric loss tangent is ideally 0, and is practically 0.0001 or more.


When the styrene resin of the present embodiment is formed into a cured product, the cured product has a low relative dielectric constant. Specifically, the relative dielectric constant of the cured product of the styrene resin of the present embodiment at a frequency of 10 GHz is preferably 2.37 or less, more preferably 2.36 or less, still more preferably 2.35 or less, even more preferably 2.33 or less, and further more preferably 2.32 or less. The lower limit of the relative dielectric constant is ideally 0, and is practically 0.01 or more.


The dielectric loss tangent and the relative dielectric constant of the cured product of the styrene resin are measured according to the method described in Examples below.


The cured product of the styrene resin of the present embodiment preferably has a high glass transition temperature. Specifically, the glass transition temperature is preferably 180° C. or higher, more preferably 200° C. or higher, still more preferably 210° C. or higher, even more preferably 213° C. or higher, and further more preferably 214° C. or higher. The upper limit of the glass transition temperature is not particularly limited, and is practically 350° C. or lower.


The glass transition temperature of the cured product of the styrene resin is measured according to the method described in Examples below.


Method for Producing Hydroxy Resin

The method for producing the hydroxy resin of the present embodiment preferably includes using the resin (T), and the resin (T) is a resin represented by Formula (T), preferably a resin represented by Formula (T1).




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(In Formula (T), R is a group containing structural units represented by Formula (Tx); Ma represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; and x represents an integer of 0 to 4.




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(In Formula (Tx), n, o, and p each represent an average number of repeating units; n represents a number of more than 0 and 20 or less; o and p each independently represent a number of 0 to 20; 1.0≤n+o+p≤20.0; Ma each independently represents a hydrocarbon group having from 1 to 12 carbons which may be substituted with a halogen atom; x represents an integer of 0 to 4; structural units are each bonded to the structural unit (a), (b), or (c), or an additional group; and the structural units may be randomly bonded.)




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(in Formula (T1). R is a group containing structural units represented by Formula (Tx).)


The hydroxy resin produced using the resin (T) as described above is an advantageous raw material of the styrene resin of the present embodiment.


In Formula (T), Ma and x each independently have the same meanings as Ma and x in Formula (Tx-OH), respectively, and preferred ranges thereof are also the same.


In Formula (Tx), n, o, and p each mean the average number of repeating units in all molecules in the resin.


In Formula (Tx), the sum of n, o, and p is preferably 1.1≤n+o+p, more preferably 1.2≤n+o+p, still more preferably 1.5≤n+o+p, even more preferably 2.0≤n+o+p, further more preferably 2.5≤n+o+p, still further more preferably 3.0≤n+o+p, and particularly preferably 3.3≤n+o+p, and much more preferably 3.55≤n+o+p, 3.7≤n+o+p, 4.0≤n+o+p, and 4.2≤n+o+p in this order. In Formula (Tx-OH), the sum of n, o, and p is also preferably n+o+p≤20.0, more preferably n+o+p≤10.0, still more preferably n+o+p≤8.0, even more preferably n+o+p≤7.0, further more preferably n+o+p≤6.5, and still further more preferably n+o+p≤6.4. The sum of n, o, and p can be calculated by the method described in Examples below.


In Formula (Tx), Ma and x have the same meanings as Ma and x in Formula (Tx-OH), respectively, and preferred ranges thereof are also the same.


However, when the compound represented by Formula (P) is reacted with the resin (T), the molecular weight tends to increase, and the value of n+o+p tends to be further increased. During the aforementioned reaction, since the structural unit (b) and the structural unit (c) in Formula (Tx) become the structural unit (a), there is a tendency that the proportion of the structural unit (a) can be increased in the hydroxy resin and the styrene resin synthesized using the hydroxy resin. As a result, lower Dk and Df can be achieved.


The resin represented by Formula (T) preferably has a parameter α calculated from Formula (α) of 0.55 or more and 1.00 or less, and a parameter β calculated from Formula (β) of 0.20 or more and 3.00 or less.










Parameter


α

=


(


2.55

ppm



2.31

ppm


)






(


6.24

ppm



5.91

ppm


)

+


(


2.98

ppm



2.55

ppm


)

/







2
+

(


2.55

ppm



2.31

ppm


)










(
α
)













Parameter


β

=




[


(


5.49

ppm



4.89

ppm


)

-

(


4.89

ppm



4.45

ppm


)



}

×
1.5



(


2.31

ppm



1.96

ppm


)

-

(


2.55

ppm



2.31

ppm


)







(
β
)







(Each of the values in parentheses in Formulae (α) and (β) indicates an integral value between the corresponding chemical shift values in 1H-NMR.)


Here, α represents the proportion of a structural unit having an indane skeleton (the structural unit (a) in Formula (Tx)). More specifically, it is presumed that when the proportion of the structural unit having an indane skeleton is adjusted so as to satisfy the range of the parameter α, the rigidity of the resulting resin molecule can be enhanced, and the glass transition temperature of a cured product can be increased. In addition, it is presumed that since a molecule having high rigidity has lower mobility than a molecule having low rigidity, a relaxation time for dielectric relaxation becomes longer, and Df can be lowered. When the resin represented by Formula (T) is synthesized, a can be increased by controlling conditions, such as decreasing the concentration of a raw material, using a highly polar solvent, increasing the amount of catalyst, and increasing the reaction temperature.


Meanwhile, β defines the proportion of a terminal double bond. β can be increased by controlling conditions, such as decreasing the amount of catalyst, decreasing the reaction temperature, and using a low-polarity solvent when the resin represented by Formula (T) is synthesized.


The parameters α and β of the resin are adjusted at the time of synthesis using the method of increasing the parameters α and β described above. Needless to say, the parameters α and β may be adjusted by a method other than that described above.


The parameter α in the resin represented by Formula (T) is preferably 0.57 or more, more preferably 0.59 or more, still more preferably 0.60 or more, and even more preferably 0.62 or more, and may be 0.65 or more, 0.70 or more, 0.75 or more, or 0.80 or more. When the parameter α is equal to or more than the above lower limit, the thermal resistance of the resulting cured product tends to be further improved. Practically, the parameter α preferably is large from the viewpoint that the low dielectric properties (Dk and/or Df) and the thermal resistance of the resulting cured product tend to be excellent. However, the parameter α may be 0.95 or less, 0.90 or less, 0.85 or less, 0.82 or less, 0.80 or less, 0.77 or less, 0.75 or less, or 0.74 or less.


The parameter β is preferably 0.25 or more, more preferably 0.30 or more, still more preferably 0.35 or more, even more preferably 0.40 or more, further more preferably 0.43 or more, and still further more preferably 0.50 or more, and may be 0.60 or more, 0.65 or more, 0.70 or more, 0.77 or more, 0.80 or more, 0.90 or more, or 0.95 or more. When the parameter s is equal to or more than the above lower limit, the thermal resistance of the resulting cured product tends to be improved, and Df tends to be lowered. The parameter β is preferably 2.50 or less, more preferably 2.00 or less, still more preferably 1.50 or less, even more preferably 1.30 or less, further more preferably 1.20 or less, and still further more preferably 1.10 or less, and may be 1.00 or less, 0.95 or less, 0.90 or less, 0.85 or less, 0.83 or less, or 0.80 or less. When the parameter 1 is equal to or lower than the above upper limit, the thermal resistance of the resulting cured product tends to be improved, and Df tends to be lowered.


The number average molecular weight (Mn) of the resin represented by Formula (T) in terms of polystyrene measured by a GPC (gel permeation chromatography) method (the details are according to the method described in Examples below) is preferably 400 or more, more preferably 500 or more, still more preferably 550 or more, even more preferably 600 or more, and further more preferably 650 or more. When the number average molecular weight is equal to or more than the above lower limit, the thermal resistance of the resulting cured product tends to be improved, and Df tends to be lowered. The upper limit of the number average molecular weight (Mn) of the resin represented by Formula (T) in terms of polystyrene measured by the GPC (gel permeation chromatography) method is preferably 3000 or less, more preferably 2500 or less, still more preferably 2000 or less, even more preferably 1500 or less, and further more preferably 1250 or less. When the number average molecular weight is equal to or lower than the above upper limit, the thermal resistance of the resulting cured product tends to be improved, and Df tends to be lowered.


The weight average molecular weight (Mw) of the resin represented by Formula (T) in terms of polystyrene measured by the GPC (the details are according to the method described in Examples below) is preferably 500 or more, more preferably 800 or more, still more preferably 900 or more, and even more preferably 1000 or more. When the weight average molecular weight is equal to or higher than the above lower limit, the thermal resistance of the resulting cured product tends to be improved, and Df tends to be lowered. The upper limit of the weight average molecular weight (Mw) of the resin represented by Formula (T) in terms of polystyrene measured by the GPC (the details are according to the method described in Examples below) is preferably 6000 or less, more preferably 5000 or less, still more preferably 4000 or less, even more preferably 3000 or less, and further more preferably 2800 or less. When the weight average molecular weight is equal to or lower than the above upper limit, the thermal resistance of the resulting cured product tends to be improved, and Df tends to be lowered.


The Mw/Mn of the resin represented by Formula (T) is more preferably 1.2 or more, still more preferably 1.3 or more, even more preferably 1.4 or more, further more preferably 1.5 or more, and still further more preferably 1.6 or more. The Mw/Mn of the resin represented by Formula (T) is more preferably 2.5 or less, still more preferably 2.4 or less, and even more preferably 2.3 or less, and may be 2.0 or less, or 1.8 or less.


The weight average molecular weight and the number average molecular weight are measured in accordance with methods described in Examples below.


The method of producing the resin (T) is not particularly limited, and a resin produced by a known production method can be used. When the resin (T) is synthesized, the raw material, the reaction temperature, the type of a catalyst, the amount of the catalyst, the reaction solvent, and the raw material concentration are not particularly limited, and can be appropriately selected or controlled depending on the desired physical properties described above.


As an example of the raw material in synthesizing the resin (T), m-bis(α-hydroxyisopropyl)benzene, p-bis(α-hydroxyisopropyl)benzene, 1,3-diisopropenylbenzene, or 1,4-diisopropenylbenzene can be used.


The reaction temperature at the time of synthesizing the resin (T) is preferably 40° C. or higher, more preferably 50° C. or higher, and still more preferably 60° C. or higher, and may be 70° C. or higher, 80° C. or higher, 90° C. or higher, 100° C. or higher, 110° C. or higher, or 120° C. or higher. When the reaction temperature is equal to or higher than the above lower limit, the reaction rate tends to be improved, and the proportion of an indane skeleton (the structural unit (a) in Formula (Tx)) tends to be improved, which is preferred. The reaction temperature is preferably 180° C. or lower, more preferably 150° C. or lower, and still more preferably 140° C. or lower. When the reaction temperature is equal to or lower than the upper limit, the production of a by-product tends to be effectively suppressed.


The reaction temperature does not need to be constant from the start to the end of the reaction, and the temperature may be varied. In this case, the average temperature of reaction temperatures in all processes preferably falls within the above range.


The catalyst used for synthesizing the resin (T) is not particularly limited, and an acid catalyst is exemplified. Examples of the acid catalyst that can be used include inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid, organic acids such as oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, and fluoromethanesulfonic acid, a BF3 ether complex, a BF3 phenol complex, Lewis acids such as aluminum chloride, zinc chloride, and indium chloride, solid acids such as activated clay, acid clay, silica alumina, and zeolite, heteropolyhydrochloric acid, and a strongly acidic ion exchange resin.


When the catalyst is used, the amount thereof is, for example, 0.01 to 20.0 parts by mass relative to 100 parts by mass of the raw material of the resin (T).


The catalyst is usually used alone, but two or more types may be used in combination. When two or more catalysts are used in combination, the total amount thereof preferably falls within the above range.


The reaction solvent for synthesizing the resin (T) is not particularly limited, and can be used in combination with an aromatic hydrocarbon-based solvent such as toluene, benzene, chlorobenzene, or xylene, a halogenated hydrocarbon-based solvent such as methylene chloride or chloroform, an aliphatic hydrocarbon-based solvent such as hexane or heptane, an ester-based solvent such as ethyl acetate or propyl acetate, an amide-based solvent such as dimethylformamide or dimethylacetamide, an alcohol solvent, or a ketone solvent, and water can also be added. Examples of the alcohol solvent include methanol, ethanol, butanol, propanol, methyl propylene diglycol, diethylene glycol ethyl ether, butyl propylene glycol, and propyl propylene glycol, and examples of the ketone solvent include acetone, methyl ethyl ketone, diethyl ketone, methyl butyl ketone, and methyl isobutyl ketone. Other examples include, but are not limited to, tetrahydrofuran and dioxane.


An example of the reaction solvent in the present embodiment contains an aromatic hydrocarbon solvent.


The concentration of the above-described raw material at the time of synthesizing the resin (T) is preferably 5% or more, more preferably 8% or more, and preferably 10% or more, and may be 12% or more, 15% or more, 17% or more, 20% or more, 22% or more, or 25% or more. When the concentration is equal to or higher than the above lower limit, the reaction rate tends to be improved, and the proportion of an indane skeleton (the structural unit (a) in Formula (Tx)) tends to be improved, which is preferred. The concentration of the above-described raw material is preferably 49% or less, and more preferably 40% or less. When the concentration is equal to or lower than the above upper limit, the production of a by-product tends to be effectively suppressed.


The concentration does not need to be constant from the start to the end of the reaction, and the concentration may be varied.


The production of the hydroxy resin of the present embodiment preferably includes reacting a compound represented by Formula (P) with the resin (T) described above. In the present embodiment, it is presumed that the proportion of the structural unit (a) in Formula (Tx) can be further increased during the addition reaction of the compound represented by Formula (P). This is presumed to be because the structural unit (b) and the structural unit (c) in Formula (Tx) become the structural unit (a) during the addition reaction. It is presumed that cationic polymerization of the resin (T) also proceeds during the addition reaction of the compound represented by Formula (P), and the total value of n+o+p in Formula (Tx) increases. As a result, it is assumed that the molecular weight of the resulting styrene resin increases, and lower Dk and lower Df can be achieved.




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(In Formula (P), Arm is each independently a benzene ring, a naphthalene ring, or an anthracene ring; Mb each independently represents a hydroxyl group, a halogen atom, or a hydrocarbon group having from 1 to 20 carbons which may be substituted with a hydroxyl group or a halogen atom; and y represents an integer of 0 to 4.)


In Formula (P), Arm is each independently a benzene ring, a naphthalene ring, or an anthracene ring, and has the same meaning as Arm in Formula (T-OH), and a preferred range is also the same.


When Arm is a benzene ring and y is an integer of 1 to 4, it is preferable that an OH group bonded to Arm and Mb are bonded to each other at one or two of an ortho-position and a para-position (preferably at least one or two ortho-positions).


In Formula (P), Mb each independently represents a hydroxyl group, a halogen atom, or a hydrocarbon group having from 1 to 20 carbons which may be substituted with a hydroxyl group or a halogen atom, and has the same meaning as Mb in Formula (T-OH), and a preferred range is also the same.


In Formula (P), y represents an integer of 0 to 4 and has the same meaning as y in Formula (T-OH), and a preferred range is also the same.


The compound represented by Formula (P) preferably contains a compound represented by Formula (P1).




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(In Formula (P1), Mb each independently represents a hydroxyl group, a halogen atom, or a hydrocarbon group having from 1 to 20 carbons which may be substituted with a hydroxyl group or a halogen atom; and y represents an integer of 0 to 4.)


In Formula (P1), Mb and y have the same meanings as Mb and y in Formula (P), respectively, and preferred ranges thereof are also the same.


In Formula (P1), when y is an integer of 1 to 4, it is preferable that an OH group bonded to a benzene ring and Mb are bonded to each other at one or two of an ortho-position and a para-position (preferably at least one or two ortho-positions).


Specific examples of the compound represented by Formula (P) include cresols such as o-cresol, m-cresol and p-cresol; phenol; xylenols such as 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol (2,6-dimethylphenol), 3,4-xylenol, and 3,5-xylenol; ethylphenols such as o-ethylphenol, m-ethylphenol, and p-ethylphenol; butylphenols such as isopropylphenol, butylphenol, and p-t-butylphenol; alkylphenols such as p-pentylphenol, p-octylphenol, p-nonylphenol, and p-cumylphenol; halogenated phenols such as fluorophenol, chlorophenol, bromophenol, and iodophenol; mono-substituted phenols such as o-phenylphenol, p-phenylphenol, 2-cyclohexylphenol, and 2-benzylphenol; fused polycyclic phenols such as 1-naphthol, 2-naphthol, 1-anthracenol, and 2-anthracenol; and polyhydric phenols such as resorcin, alkylresorcin, pyrogallol, catechol, alkylcatechol, hydroquinone, alkylhydroquinone, and phloroglucin. These phenols or derivatives thereof may be used alone or in combination of two or more types thereof.


Among them, the compound represented by Formula (P) is more preferably, for example, a compound (preferably a linear alkyl-substituted compound, more preferably a compound substituted with a methyl group) in which two of an ortho-position and a para-position are alkyl-substituted with respect to a phenolic hydroxyl group such as 2,6-xylenol, 2,4-xylenol, or 2-cyclohexyl-6-methylphenol (preferably 2,6-xylenol or 2,4-xylenol).


The compound represented by Formula (P) is also preferably a compound having a group having a cyclic structure at an ortho-position of a phenolic hydroxyl group, such as 2-cyclohexylphenol or 2-benzylphenol.


More specifically, the compound represented by Formula (P) is preferably phenol, 2,6-xylenol, 2,4-xylenol, 2-cyclohexylphenol, 2-cyclohexyl-6-methylphenol, or 2-benzylphenol, and more preferably phenol, 2,6-xylenol, or 2-benzylphenol.


In the present embodiment, when the compound represented by Formula (P) is reacted with the resin (T), the total content of m-bis(α-hydroxyisopropyl)benzene, p-bis(α-hydroxyisopropyl)benzene, 1,3-diisopropenylbenzene, and 1,4-diisopropenylbenzene in the reaction system is preferably 10 mass % or less, more preferably 8 mass % or less, still more preferably 5 mass % or less, even more preferably 3 mass % or less, further more preferably 2 mass % or less, and still further more preferably 1 mass % or less, relative to the amount of the resin (T). When the total content is equal to or lower than the above upper limit, the molecular weight of the hydroxy resin tends to be increased, which is preferred.


The molecular weight (Mw, Mn) of the hydroxy resin of the present embodiment can be controlled by, for example, synthesis via the resin (T), the reaction temperature, the catalyst type, the catalyst amount, and the reaction solvent.


In the present embodiment, the amount of the compound represented by Formula (P) used during reaction of the compound represented by Formula (P) with the resin (T) is preferably 1 to 200 parts by mass relative to 100 parts by mass of the resin (T).


In the present embodiment, the reaction temperature during reaction of the compound represented by Formula (P) with the resin (T) is preferably 50° C. or higher, more preferably 60° C. or higher, still more preferably 70° C. or higher, even more preferably 80° C. or higher, further more preferably 100° C. or higher, and still further more preferably 120° C. or higher. When the reaction temperature is equal to or higher than the above lower limit, the reaction rate tends to be improved and the proportion of the indane skeleton (the structural unit (a) in Formula (Tx-OH)) tends to be increased, which is preferred. The reaction temperature is preferably 200° C. or lower, and more preferably 150° C. or lower. When the reaction temperature is equal to or lower than the above upper limit, the production of a by-product tends to be effectively suppressed.


The reaction temperature does not need to be constant from the start to the end of the reaction, and the temperature may be varied. In this case, the average temperature of reaction temperatures in all processes preferably falls within the above range.


In the present embodiment, the catalyst used for reacting the compound represented by Formula (P) with the resin (T) is not particularly limited, and an acid catalyst is exemplified. Examples of the acid catalyst that can be used include inorganic acids such as hydrochloric acid, sulfuric acid, and phosphoric acid, organic acids such as oxalic acid, benzenesulfonic acid, toluenesulfonic acid, methanesulfonic acid, and fluoromethanesulfonic acid, a BF3 ether complex, a BF3 phenol complex, Lewis acids such as aluminum chloride, zinc chloride, and indium chloride, solid acids such as activated clay, acid clay, silica alumina, and zeolite, heteropolyhydrochloric acid, and a strongly acidic ion exchange resin.


When the catalyst is used, the amount of the catalyst is, for example, 0.01 to 30.0 parts by mass relative to 100 parts by mass of the resin (T) as the raw material.


The catalyst is usually used alone, but two or more types may be used in combination. When two or more catalysts are used in combination, the total amount thereof preferably falls within the above range.


In the present embodiment, the reaction solvent used for reacting the compound represented by Formula (P) with the resin (T) is not particularly limited, and can be used in combination with an aromatic hydrocarbon-based solvent such as toluene, benzene, chlorobenzene, or xylene, a halogenated hydrocarbon-based solvent such as methylene chloride or chloroform, an aliphatic hydrocarbon-based solvent such as hexane or heptane, an ester-based solvent such as ethyl acetate or propyl acetate, an amide-based solvent such as dimethylformamide or dimethylacetamide, an alcohol solvent, or a ketone solvent. Examples of the alcohol solvent include methanol, ethanol, butanol, propanol, methyl propylene diglycol, diethylene glycol ethyl ether, butyl propylene glycol, and propyl propylene glycol, and examples of the ketone solvent include acetone, methyl ethyl ketone, diethyl ketone, methyl butyl ketone, and methyl isobutyl ketone. Other examples include, but are not limited to, tetrahydrofuran and dioxane.


An example of the reaction solvent in the present embodiment contains an aromatic hydrocarbon solvent.


In the present embodiment, when a solvent having high polarity is used, a carbocation as an intermediate can be stabilized, and a hydroxy resin of higher molecular weight can be produced.


When the solvent is used, the amount of the solvent is, for example, 10 to 1000 parts by mass relative to 100 parts by mass of the resin (T) as the raw material.


These solvents may be used alone or in combination of two or more types. When two or more solvents are used, the amount of the mixture preferably falls within the above range.


Method for Producing Styrene Resin

The styrene resin of the present embodiment can be produced by using the hydroxy resin of the present embodiment.


More specifically, the method for producing the styrene resin of the present embodiment preferably includes reacting a compound represented by Formula (S) with the hydroxy resin of the present embodiment.




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(In Formula (S), Hr represents a chlorine atom or a bromine atom; Mc represents a hydrocarbon group having from 1 to 12 carbons; z represents an integer of 0 to 4; r represents an integer of 1 to 6; and R1, R2, and R3 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group.)


In Formula (S), Hr represents a chlorine atom or a bromine atom, and is preferably a chlorine atom.


In Formula (S), Mc has the same meaning as Mc in Formula (T-St), and a preferred range is also the same.


In Formula (S), z represents an integer of 0 to 4 and has the same meaning as z in Formula (T-St), and a preferred range is also the same.


In Formula (S), r represents an integer of 1 to 6 and has the same meaning as r in Formula (T-St), and a preferred range is also the same.


In Formula (S), R1, R2, and R3 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group, and have the same meanings as R1, R2, and R3 in Formula (T-St), respectively, and preferred ranges thereof are also the same.


The amount of the compound represented by Formula (S) used during reaction of the compound represented by Formula (S) with the hydroxy resin of the present embodiment is preferably 1 to 100 parts by mass relative to 100 parts by mass of the hydroxy resin.


The reaction temperature during reaction of the compound represented by Formula (S) with the hydroxy resin of the present embodiment is preferably 50° C. or higher, and preferably 100° C. or lower.


When the compound represented by Formula (S) is reacted with the hydroxy resin of the present embodiment, the reaction is preferably carried out in the presence of a solvent. The solvent can be used in combination with an aromatic hydrocarbon-based solvent such as toluene, benzene, chlorobenzene, or xylene, a halogenated hydrocarbon-based solvent such as methylene chloride or chloroform, an aliphatic hydrocarbon-based solvent such as hexane or heptane, an ester-based solvent such as ethyl acetate or propyl acetate, an amide-based solvent such as dimethylformamide or dimethylacetamide, an alcohol solvent, or a ketone solvent. Examples of the alcohol solvent include methanol, ethanol, butanol, propanol, methyl propylene diglycol, diethylene glycol ethyl ether, butyl propylene glycol, and propyl propylene glycol, and examples of the ketone solvent include acetone, methyl ethyl ketone, diethyl ketone, methyl butyl ketone, and methyl isobutyl ketone. Other examples include, but are not limited to, tetrahydrofuran and dioxane.


The solvent is, for example, used in an amount of about 100 to 1000 parts by mass relative to 100 parts by mass of the hydroxy resin as a raw material.


As for the method for producing the styrene resin of the present embodiment, synthesizing the styrene resin by a dehydrohalogenation reaction of the hydroxy resin of the present embodiment and the compound represented by Formula (S) under basic conditions in the presence of a phase transfer catalyst is preferred.


Typical examples of the phase transfer catalyst include, but are not limited to, tertiary amines such as triethylamine and tetramethylethylenediamine, and quaternary ammonium salts or a quaternary phosphonium salts such as tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, benzyltri-n-butylammonium chloride, benzyltri-n-butylammonium bromide, and benzyl-n-butylammonium iodide. In the present embodiment, examples of the phase transfer catalyst include a quaternary ammonium salt.


The phase transfer catalyst is, for example, used in an amount of about 1 to 100 parts by mass relative to 100 parts by mass of the hydroxy resin as a raw material.


Examples of the base include an alkali metal-containing compound and/or an alkaline earth metal salt-containing compound. More specifically, typical examples of the base include sodium hydroxide, potassium hydroxide, sodium methoxide, sodium ethoxide, calcium hydroxide, sodium carbonate, potassium carbonate, and sodium bicarbonate. It goes without saying that a base other than these bases may be used.


The base is, for example, used in an amount of about 1 to 100 parts by mass relative to 100 parts by mass of the hydroxy resin as a raw material.


The method for producing the styrene resin of the present embodiment preferably includes a step of removing at least the compound represented by Formula (S), preferably a low molecular weight compound (compound having a molecular weight of 400 or less) containing a chlorine atom and/or a bromine atom. By removing such a compound, the thermal resistance of the resulting styrene resin is improved. The cured product of the resulting styrene resin tends to have lower Dk and lower Df. The step of removing the compound represented by Formula (S) is more preferably performed after washing following the reaction of the hydroxy resin and the compound represented by Formula (S).


Resin Composition

The resin composition of the present embodiment contains the styrene resin of the present embodiment. Since the styrene resin of the present embodiment is contained, the resulting cured product has excellent thermal resistance and excellent low dielectric properties (Dk and/or Df).


The content of the styrene resin in the resin composition of the present embodiment is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and may be 10 parts by mass or more, and may be 15 parts by mass or more, or 20 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. The upper limit of the content of the styrene resin in the resin composition of the present embodiment may be 100 parts by mass relative to 100 parts by mass of the resin solid content in the resin composition, and is preferably 70 parts by mass or less, more preferably 65 parts by mass or less, still more preferably 60 parts by mass or less, even more preferably 55 parts by mass or less, and further more preferably 50 parts by mass or less.


The resin composition of the present embodiment may contain only one type of the styrene resin of the present embodiment or may contain two or more types thereof. When two or more types of the styrene resin are contained, the total amount thereof preferably falls within the above range.


Additional Resin Component

The resin composition of the present embodiment may contain, in addition to the styrene resin of the present embodiment, a thermoplastic resin and/or an additional resin component other than the styrene resin of the present embodiment. In particular, the resin composition of the present embodiment preferably contains an additional curable compound (C) (preferably, a thermosetting compound). The thermoplastic resin preferably includes an elastomer and a petroleum resin.


The additional curable compound (C) preferably contains one or more selected from the group consisting of a polyphenylene ether compound having an unsaturated carbon-carbon double bond at a terminal, a polymer having a structural unit represented by Formula (V), a maleimide compound, a cyanate ester compound, an epoxy compound, a phenol compound, a compound containing a (meth)allyl group, an oxetane resin, a benzoxazine compound, an arylcyclobutene resin, a polyamide resin, a polyimide resin, a perfluorovinyl ether resin, a compound having a styrene group other than the polyphenylene ether compound having an unsaturated carbon-carbon double bond at a terminal and the styrene resin represented by Formula (T-St), a compound having an isopropenyl group other than the resin represented by Formula (T) above, and a polyfunctional (meth)acrylate compound other than the polyphenylene ether compound having an unsaturated carbon-carbon double bond at a terminal, and more preferably contains one or more selected from the group consisting of a polyphenylene ether compound having an unsaturated carbon-carbon double bond at a terminal, a polymer having a structural unit represented by Formula (V), and a maleimide compound. When such a component is contained, it is possible to more effectively achieve a desired performance required for a printed wiring board.




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(In Formula (V), Ar represents an aromatic hydrocarbon linking group; and * represents a bonding position.)


When the resin composition of the present embodiment contains the additional curable compound (C), the content (total amount) of the additional curable compound is preferably 1 part by mass or more, more preferably 10 parts by mass or more, and still more preferably 15 parts by mass or more, and may be 20 parts by mass or more and 30 parts by mass or more relative to 100 parts by mass of the resin solid content. When the content is equal to or higher than the above lower limit, thermal resistance, plating adhesion, and low thermal expansion tend to be further improved. The upper limit of the content of the additional curable compound (C) is preferably 99 parts by mass or less, more preferably 90 parts by mass or less, and still more preferably 85 parts by mass or less, and may be 80 parts by mass or less or 70 parts by mass or less, relative to 100 parts by mass of the resin solid content. When the content is equal to or lower than the above upper limit, the low dielectric properties (Dk and/or Df) and the low water absorbability of the resulting cured product tend to be further improved.


The resin composition of the present embodiment may contain only one, or two or more additional curable compounds (C). When two or more additional curable compounds are contained, the total amount thereof preferably falls within the above range.


Polyphenylene Ether Compound Containing Unsaturated Carbon-Carbon Double Bond at Terminal

The resin composition of the present embodiment contains the polyphenylene ether compound having an unsaturated carbon-carbon double bond at a terminal. In the present embodiment, the polyphenylene ether compound preferably contains a polyphenylene ether compound containing two or more unsaturated carbon-carbon double bonds.


The polyphenylene ether compound having an unsaturated carbon-carbon double bond at a terminal is preferably a polyphenylene ether compound having, at a terminal, a group selected from the group consisting of a group represented by Formula (Rx-1) such as a vinylbenzyl group, a group represented by Formula (Rx-2) such as a (meth)acrylic group, and a maleimide group, more preferably a polyphenylene ether compound having a group represented by Formula (Rx-1) such as a vinylbenzyl group and/or a group represented by Formula (Rx-2) such as a (meth)acrylic group, and still more preferably a polyphenylene ether compound having two or more groups represented by Formula (Rx-1) such as a vinylbenzyl group and/or two or more groups represented by Formula (Rx-2) such as a (meth)acrylic group at a terminal.




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(In Formula (Rx-1) and Formula (Rx-2), R1, R2, and R3 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group; * is a bonding site to an oxygen atom; Mc each independently represents a hydrocarbon group having from 1 to 12 carbons; z represents an integer of 0 to 4; and r represents an integer of 1 to 6.)


When such a polyphenylene ether compound is used, the low dielectric properties (Dk and/or Df) and low water absorbability of a printed wiring board or the like tend to be more effectively improved. In the present embodiment, a polyphenylene ether compound having a vinylbenzyl group at a terminal is particularly preferred. A polyphenylene ether compound having a vinylbenzyl group tends to have significantly improved compatibility with the resin (A).


Hereinafter, these details will be described.


Examples of the polyphenylene ether compound having an unsaturated carbon-carbon double bond at a terminal (preferably, the polyphenylene ether compound having two or more unsaturated carbon-carbon double bonds) include a compound having a phenylene ether skeleton represented by Formula (X1) below.




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(In Formula (X1), R24, R25, R26, and R27 may be identical to or different from one another, and each represent an alkyl group having 6 or less carbons, an aryl group, a halogen atom, or a hydrogen atom.)


The polyphenylene ether compound having an unsaturated carbon-carbon double bond at a terminal (preferably, the polyphenylene ether compound having two or more unsaturated carbon-carbon double bonds) may further contain a repeating unit represented by Formula (X2):




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(in Formula (X2), R28, R29, R30, R34, and R35 may be identical to or different from one another, and each represent an alkyl group having 6 or less carbons or a phenyl group; R31, R32, and R33 may be identical to or different from one another, and each represent a hydrogen atom, an alkyl group having 6 or less carbons, or a phenyl group, and/or a repeating unit represented by Formula (X3):




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(in Formula (X3), R36, R37, R38, R39, R40, R41, R42, and R43 may be identical to or different from one another, and each represent a hydrogen atom, an alkyl group having 6 or less carbons, or a phenyl group; and -A- is a linear, branched, or cyclic divalent hydrocarbon group having 20 or less carbons).


The polyphenylene ether compound having an unsaturated carbon-carbon double bond at a terminal (preferably, the polyphenylene ether compound having two or more unsaturated carbon-carbon double bonds) is preferably a modified polyphenylene ether compound in which a portion or the entirety of the terminal is functionalized with an ethylenically unsaturated group (hereinafter may be referred to as a “modified polyphenylene ether compound (g)”), more preferably a modified polyphenylene ether compound having, at a terminal, two or more groups selected from the group consisting of a group represented by Formula (Rx-1) such as a vinylbenzyl group, a group represented by Formula (Rx-2) such as a (meth)acrylic group, and a maleimide group, and still more preferably a group represented by Formula (Rx-1) such as a vinylbenzyl group and/or a group represented by Formula (Rx-2) such as a (meth)acrylic group. By employing such a modified polyphenylene ether compound (g), it is possible to further reduce the low dielectric properties (Dk and/or Df) of the cured product of the resin composition, improve the low water absorbability, and increase metal foil peel strength. One of these may be used, or two or more may be used in combination.


Examples of the modified polyphenylene ether compound (g) include a polyphenylene ether compound represented by Formula (OP).




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(In Formula (OP), X represents an aromatic group; —(Y—O)n1— represents a polyphenylene ether structure; n1 represents an integer of 1 to 100; and n2 represents an integer of 1 to 4; and Rx is a group represented by Formula (Rx-1) or Formula (Rx-2))




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(In Formula (Rx-1) and Formula (Rx-2), R1, R2, and R3 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group; * is a bonding site to an oxygen atom; Mc each independently represents a hydrocarbon group having from 1 to 12 carbons; z represents an integer of 0 to 4; and r represents an integer of 1 to 6.)


When n1 and/or n2 is an integer of 2 or more, n1 structural units (Y—O) and/or n2 structural units may be identical to or different from one another. n2 is preferably 2 or more, and more preferably 2.


In Formula (Rx-1) and Formula (Rx-2), R1, R2, and R3 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group.


R1 is preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a methyl group, and still more preferably a hydrogen atom.


R2 and R3 are each independently preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a methyl group, and still more preferably a hydrogen atom.


The number of carbons of the alkyl group, the alkenyl group, or the alkynyl group represented by each of R1, R2, and R3 is preferably 5 or less, and more preferably 3 or less.


In Formula (Rx-1), r represents an integer of 1 to 6, and is preferably an integer of 1 to 5, more preferably an integer of 1 to 4, still more preferably an integer of 1 to 3, even more preferably 1 or 2, and further more preferably 1.


In Formula (Rx-1), Mc each independently represents a hydrocarbon group having from 1 to 12 carbons, and is preferably a hydrocarbon group having from 1 to 10 carbons, more preferably a linear or branched alkyl group having from 1 to 10 carbons, still more preferably a methyl group, an ethyl group, an isopropyl group, an isobutyl group, a t-butyl group, a pentyl group, an octyl group, or a nonyl group, and even more preferably a methyl group, an ethyl group, an isopropyl group, an isobutyl group, or a t-butyl group.


In Formula (Rx-1), z represents an integer of 0 to 4, and is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, still more preferably 0 or 1, and even more preferably 0.


A specific example of the group represented by Formula (Rx-1) is a vinylbenzyl group, and a specific example of the group represented by Formula (Rx-2) is a (meth)acryloyl group.


Rx is preferably a group represented by Formula (Rx-1).


Examples of the modified polyphenylene ether compound (g) include a polyphenylene ether compound represented by Formula (OP-1).




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(In Formula (OP-1), X represents an aromatic group; —(Y—O)n2- represents a polyphenylene ether structure; R1, R2, and R3 each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group; n1 represents an integer of from 1 to 6; n2 represents an integer of from 1 to 100; and n3 represents an integer of from 1 to 4.)


When n2 and/or n3 is an integer of 2 or more, n2 structural units (Y—O) and/or n3 structural units may be identical to or different from each other. n3 is preferably 2 or more, and more preferably 2.


The modified polyphenylene ether compound (g) in the present embodiment is also preferably a compound represented by Formula (OP-2), and more preferably a compound represented by Formula (OP-2-2).




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In this case, —(O—X—O)— is preferably represented by Formula (OP-3):




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(in Formula (OP-3), R4, R5, R6, R10, and R11 may be identical to or different from one another, and are each an alkyl group having 6 or less carbons or a phenyl group; R7, R8, and R9 may be identical to or different from one another, and are each a hydrogen atom, an alkyl group having 6 or less carbons, or a phenyl group;


and/or Formula (OP-4):




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(in Formula (OP-4), R12, R13, R14, R15, R16, R17, R18, and R19 may be identical to or different from one another, and are each a hydrogen atom, an alkyl group having 6 or less carbons, or a phenyl group; and -A- is a linear, branched, or cyclic divalent hydrocarbon group having 20 or less carbons).


Moreover, —(Y—O)— is preferably represented by Formula (OP-5):




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(in Formula (OP-5), R20 and R21 may be identical to or different from each other, and are each an alkyl group having 6 or less carbons or a phenyl group; R22 and R23 may be identical to or different from each other, and are each a hydrogen atom, an alkyl group having 6 or less carbons, or a phenyl group). In particular, when R20 and R21 are each independently a group having one or more methyl groups and/or cyclohexyl groups, the rigidity of the resulting resin molecule is increased, and a molecule having high rigidity has lower mobility than a molecule having low rigidity, so that a relaxation time during dielectric relaxation is lengthened, and the low dielectric properties (Dk and/or Df) are improved, which is preferred.


An example of Formula (OP-5) is the following structure.




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For the polyphenylene compound having the above structure, reference can be made to the description of JP 2019-194312 A, the content of which is incorporated herein by reference.


In Formula (OP-2), a and b each independently represent an integer of 0 to 100, and at least one of a and b is an integer of 1 to 100. a and b are each independently preferably an integer of 0 to 50, more preferably an integer of 1 to 30, and preferably an integer of 1 to 10. When a and/or b is an integer of 2 or more, two or more —(Y—O)— may each independently be in an arrangement of one type of structure or, a block or random arrangement of two or more types of structures.


When a plurality of compounds represented by Formula (OP-2) are contained, an average value of a is preferably 1<a<10, and an average value of b is preferably 1<b<10.


Examples of -A- in Formula (OP-4) include, but are not limited to, divalent organic groups such as a methylene group, an ethylidene group, a 1-methylethylidene group, a 1,1-propylidene group, a 1,4-phenylenebis(1-methylethylidene) group, a 1,3-phenylenebis(l-methylethylidene) group, a cyclohexylidene group, a phenylmethylene group, a naphthylmethylene group, and a 1-phenylethylidene group.


Rx has the same meaning as Rx in Formula (OP), and the preferred range is also the same.


Among the compounds represented by Formula (OP-2), preferred is a polyphenylene ether compound in which R4, R5, R6, R10, R11, R20, and R21 are each an alkyl group having 3 or less carbons, and R7, R8, R9, R12, R13, R14, R15, R16, R17, R18, R19, R22, and R23 are each a hydrogen atom or an alkyl group having 3 or less carbons, and in particular, —(O—X—O)— represented by Formula (OP-3) or Formula (OP-4) is preferably Formula (OP-9), Formula (OP-10), and/or Formula (OP-11), and —(Y—O)— represented by Formula (OP-5) is preferably Formula (OP-12) or Formula (OP-13). When a and/or b is an integer of 2 or more, two or more —(Y—O)— may each independently have a structure in which two or more of Formula (OP-12) and/or Formula (OP-13) are arranged, or a structure in which Formula (OP-12) and Formula (OP-13) are arranged in a block or random manner.




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(In Formula (OP-10), R44, R45, R46, and R47 may be identical to or different from one another, and are each a hydrogen atom or a methyl group; and —B— is a linear, branched, or cyclic divalent hydrocarbon group having 20 or less carbons.)


Specific examples of —B— include the same as those for the specific examples of -A- in Formula (OP-4).




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(In Formula (OP-11), —B— is a linear, branched, or cyclic divalent hydrocarbon group having 20 or less carbons.)


Specific examples of —B— include the same as those for the specific examples of -A- in Formula (OP-4).




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The modified polyphenylene ether compound (g) used in the present embodiment is more preferably a compound represented by Formula (OP-14) and/or a compound represented by Formula (OP-15).




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(In Formula (OP-14), a and b each independently represent an integer of 0 to 100, and at least one of a and b is an integer of 1 to 100.)


In Formula (OP-14), a and b each have the same meanings as a and b in Formula (OP-2), and preferred ranges thereof are also the same.




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(In Formula (OP-15), a and b each independently represent an integer of 0 to 100, and at least one of a and b is an integer of 1 to 100.)


In Formula (OP-15), a and b each have the same meanings as a and b in Formula (OP-2), and preferred ranges thereof are also the same.


The number average molecular weight (Mn) of the polyphenylene ether compound having an unsaturated carbon-carbon double bond at a terminal (preferably, the polyphenylene ether compound having two or more unsaturated carbon-carbon double bonds, more preferably the modified polyphenylene ether compound (g)) in terms of polystyrene measured by the GPC (gel permeation chromatography) method (the details are according to the method described in Examples below) is, for example, preferably 500 or more and further preferably 800 or more, and preferably 3000 or less. When the number average molecular weight is 500 or more, stickiness tends to be further prevented when the resin composition of the present embodiment is formed into a coating film. When the number average molecular weight is 3000 or less, the solubility in a solvent tends to be further improved.


The weight average molecular weight (Mw) of the polyphenylene ether compound having an unsaturated carbon-carbon double bond at a terminal (preferably, the polyphenylene ether compound having two or more unsaturated carbon-carbon double bonds, more preferably the modified polyphenylene ether compound (g)) in terms of polystyrene measured by the GPC (the details are according to the method described in Examples below) is preferably 800 or more and 6000 or less, and more preferably 800 or more and 5000 or less. When the weight average molecular weight is equal to or higher than the lower limit, the relative dielectric constant (Dk) and dielectric loss tangent (Df) of a cured product of the resin composition tends to further decrease, whereas when the weight average molecular weight is equal to or lower than the upper limit, the solubility of the resin composition in a solvent, and the low viscosity properties and the moldability of the resin composition tend to be further improved during production of the below-described varnish.


Furthermore, in the case of the modified polyphenylene ether compound (g), the terminal unsaturated carbon-carbon double bond equivalent is preferably from 400 g to 5000 g and more preferably from 400 g to 2500 g per unsaturated carbon-carbon double bond. When the terminal unsaturated carbon-carbon double bond equivalent is equal to or more than the above lower limit, the relative dielectric constant (Dk) and dielectric loss tangent (Df) of the cured product of the resin composition tend to further decrease. When the terminal unsaturated carbon-carbon double bond equivalent is equal to or lower than the above upper limit, the solubility of the resin composition in a solvent, and the low viscosity properties and moldability of the resin composition tend to be further improved.


The lower limit of the content of the polyphenylene ether compound having an unsaturated carbon-carbon double bond at a terminal (preferably, the polyphenylene ether compound having two or more unsaturated carbon-carbon double bonds) in the resin composition of the present embodiment is 10 parts by mass or more, preferably 50 parts by mass or more, more preferably 100 parts by mass or more, still more preferably 150 parts by mass or more, and may be 180 parts by mass or more, relative to 100 parts by mass of the resin (A). When the content is equal to or higher than the above lower limit, the moldability of the resin composition, the low water absorbability and the low dielectric properties (Dk and/or Df) of the resulting cured product tend to be further improved. The upper limit of the content of the polyphenylene ether compound having an unsaturated carbon-carbon double bond at a terminal (preferably, the polyphenylene ether compound having two or more unsaturated carbon-carbon double bonds) is 300 parts by mass or less, preferably 280 parts by mass or less, more preferably parts by mass or less, may be 250 parts by mass or less, and may be further 220 parts by mass or less, relative to 100 parts by mass of the resin (A). When the content is equal to or lower than the above upper limit, the low dielectric properties (Dk and/or Df), thermal resistance, and chemical resistance of the resulting cured product tend to be further improved.


The total content of the resin (A) and the polyphenylene ether compound relative to 100 parts by mass of the resin solid content in the resin composition of the present embodiment is preferably 40 parts by mass or more, more preferably 45 parts by mass or more, still more preferably 50 parts by mass or more, and may be 55 parts by mass or more. When the total content of the resin (A) and the polyphenylene ether compound is equal to or higher than the above lower limit, the low water absorbability and the low dielectric properties (Dk and/or Df) of the resulting cured product tend to be further improved. The total content of the resin (A) and the polyphenylene ether compound relative to 100 parts by mass of the resin solid content in the resin composition is preferably 80 parts by mass or less. When the total content of the resin (A) and the polyphenylene ether compound is equal to or lower than the above upper limit, there is a tendency that the moldability of the resin composition, and the low dielectric properties (Dk and/or Df) of the thermal resistance, and the chemical resistance of the resulting cured product are well-balanced.


The resin composition of the present embodiment may contain only one type, or two or more types of polyphenylene ether compounds containing an unsaturated carbon-carbon double bond at a terminal. When two or more types of polyphenylene ether compounds are contained, the total amount thereof preferably falls within the above range.


Polymer Having Structural Unit Represented by Formula (V)

The resin composition of the present embodiment preferably contains a polymer having a structural unit represented by Formula (V). When the polymer having a structural unit represented by Formula (V) is contained, a resin composition capable of providing a cured product having excellent low dielectric properties (Dk and/or Df) is obtained.




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(In Formula (V), Ar represents an aromatic hydrocarbon linking group; and * represents a bonding position.)


The aromatic hydrocarbon linking group may be a group containing only an aromatic hydrocarbon that may have a substituent, or a group containing a combination of an aromatic hydrocarbon that may have a substituent and any other linking group, and is preferably a group containing only an aromatic hydrocarbon that may have a substituent. Examples of the substituent which may be possessed by the aromatic hydrocarbon include a substituent Z (for example, an alkyl group having from 1 to 6 carbons, an alkenyl group having from 2 to 6 carbons, an alkynyl group having from 2 to 6 carbons, an alkoxy group having from 1 to 6 carbons, a hydroxy group, an amino group, a carboxy group, or a halogen atom). Preferably, the aromatic hydrocarbon has no substituent.


The aromatic hydrocarbon linking group is typically a divalent linking group.


Specific examples of the aromatic hydrocarbon linking group include a phenylene group, a naphthalenediyl group, an anthracenediyl group, a phenanthrenediyl group, a biphenyldiyl group, and a fluorenediyl group, all of which may have a substituent. Among these, a phenylene group that may have a substituent is preferred. The substituent is exemplified by the substituent Z described above, while the group described above such as a phenylene group preferably has no substituent.


The structural unit represented by Formula (V) more preferably contains at least one of a structural unit represented by Formula (V1) below, a structural unit represented by Formula (V2) below, or a structural unit represented by Formula (V3) below. In Formulae below, * represents a bonding position. Hereinafter, structural units represented by Formulae (V1) to (V3) may be collectively referred to as “structural unit (a)”.




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In Formulae (V1) to (V3), L1 is an aromatic hydrocarbon linking group (having preferably from 6 to 22, more preferably from 6 to 18, and even more preferably from 6 to 10 carbons). Specific examples of the aromatic hydrocarbon linking group include a phenylene group, a naphthalenediyl group, an anthracenediyl group, a phenanthrenediyl group, a biphenyldiyl group, and a fluorenediyl group, all of which may have a substituent. Among these, a phenylene group that may have a substituent is preferred. The substituent is exemplified by the substituent Z described above, while the group described above such as a phenylene group preferably has no substituent.


The compound forming the structural unit (a) is preferably a divinyl aromatic compound, and examples thereof include divinylbenzene, bis(1-methylvinyl)benzene, divinylnaphthalene, divinylanthracene, divinylbiphenyl, and divinylphenanthrene. Among these, divinylbenzene is particularly preferred. One of these divinyl aromatic compounds may be used, or two or more types may be used as necessary.


The polymer having the structural unit represented by Formula (V) may be a homopolymer of the structural unit (a) as described above, but it may be a copolymer with a structural unit derived from an additional monomer.


When the polymer having the structural unit represented by Formula (V) is a copolymer, the copolymerization ratio of the structural unit (a) is preferably 3 mol % or more, more preferably 5 mol % or more, even more preferably 10 mol % or more, and yet even more preferably 15 mol % or more. The upper limit is preferably 90 mol % or less, more preferably 85 mol % or less, even more preferably 80 mol % or less, yet even more preferably 70 mol % or less, yet even more preferably 60 mol % or less, yet even more preferably 50 mol % or less, yet even more preferably 40 mol % or less, and particularly preferably 30 mol % or less, and further may be 25 mol % or less, or 20 mol % or less.


Examples of the structural unit derived from an additional monomer include a structural unit (b) derived from an aromatic compound having one vinyl group (monovinyl aromatic compound).


The structural unit (b) derived from the monovinyl aromatic compound is preferably a structural unit represented by Formula (V4) below.




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In Formula (V4), L2 is an aromatic hydrocarbon linking group, and specific preferred examples include the above-exemplified ones for L1.


RV1 is a hydrogen atom or a hydrocarbon group having from 1 to 12 carbons (preferably an alkyl group). When RV1 is a hydrocarbon group, the number of its carbons is preferably from 1 to 6 and more preferably from 1 to 3. RV1 and L2 may have the substituent Z described above.


When the polymer having the structural unit represented by Formula (V) is a copolymer containing the structural unit (b) derived from a monovinyl aromatic compound, examples of the monovinyl aromatic compound include vinyl aromatic compounds such as styrene, vinylnaphthalene, and vinylbiphenyl; and nuclear alkyl-substituted vinyl aromatic compounds such as o-methylstyrene, m-methylstyrene, p-methylstyrene, o,p-dimethylstyrene, o-ethylvinylbenzene, m-ethylvinylbenzene, p-ethylvinylbenzene, methylvinylbiphenyl, and ethylvinylbiphenyl. The monovinyl aromatic compound exemplified here may have the substituent Z described above as appropriate. In addition, one, or two or more of these monovinyl aromatic compounds may be used.


When the polymer having the structural unit represented by Formula (V) is a copolymer containing the structural unit (b), the copolymerization ratio of the structural unit (b) is preferably 10 mol % or more, and more preferably 15 mol % or more, and further may be 20 mol % or more, 30 mol % or more, 40 mol % or more, 50 mol % or more, 60 mol % or more, 70 mol % or more, or 75 mol % or more. The upper limit is preferably 98 mol % or less, more preferably 90 mol % or less, and even more preferably 85 mol % or less.


The polymer having the structural unit represented by Formula (V) may have an additional structural unit other than the structural unit (a) and the structural unit (b). Examples of the additional structural unit include a structural unit (c) derived from a cycloolefin compound. Examples of the cycloolefin compound include hydrocarbons having a double bond in the ring structure. Specific examples include monocyclic olefins, such as cyclobutene, cyclopentene, cyclohexene, and cyclooctene; compounds having a norbornene ring structure, such as norbornene and dicyclopentadiene; and cycloolefin compounds in which an aromatic ring is fused, such as indene and acenaphthylene. Examples of the norbornene compound include those described in paragraphs [0037] to [0043] of JP 2018-39995 A, the content of which is incorporated herein by reference. The cycloolefin compounds exemplified here may further have the substituent Z described above.


When the polymer having the structural unit represented by Formula (V) is a copolymer containing the structural unit (c), the copolymerization ratio of the structural unit (c) is preferably 10 mol % or more, more preferably 20 mol % or more, and still more preferably 30 mol % or more. The upper limit is preferably 90 mol % or less, more preferably 80 mol % or less, even more preferably 70 mol % or less, and may be 50 mol % or less or 30 mol % or less.


The polymer having the structural unit represented by Formula (V) may further contain a structural unit (d) derived from a different polymerizable compound (hereinafter may be referred to as an additional polymerizable compound). Examples of the additional polymerizable compound (monomer) include compounds containing three vinyl groups. Specific examples include 1,3,5-trivinylbenzene, 1,3,5-trivinylnaphthalene, and 1,2,4-trivinylcyclohexane. Alternatively, ethylene glycol diacrylate or butadiene is exemplified. The copolymerization ratio of the structural unit (d) derived from the additional polymerizable compound is preferably 30 mol % or less, more preferably 20 mol % or less, and even more preferably 10 mol % or less.


An embodiment of the polymer having the structural unit represented by Formula (V) is exemplified by a polymer containing the structural unit (a) as an essential unit and at least one of the structural units (b) to (d). Furthermore, an aspect in which the total of the structural units (a) to (d) accounts for 95 mol % or more or even 98 mol % or more of all the structural units is exemplified.


Another embodiment of the polymer having the structural unit represented by Formula (V) is a polymer containing the structural unit (a) as an essential unit, in which a structural unit containing an aromatic ring accounts for preferably 90 mol % or more, and more preferably 95 mol % or more, or may account for 100 mol %, of all the structural units excluding the terminal.


In calculating the mol % relative to all the structural units, one structural unit is defined as a unit derived from one molecule of a monomer (for example, a divinyl aromatic compound, or a monovinyl aromatic compound) used for producing the polymer having the structural unit represented by Formula (V).


The method for producing the polymer having the structural unit represented by Formula (V) is not particularly limited, and the production may be performed according to a common method. Examples of the method include polymerizing a raw material containing a divinyl aromatic compound (in the coexistence of a monovinyl aromatic compound, a cycloolefin compound, or the like as necessary) in the presence of a Lewis acid catalyst. A metal fluoride such as boron trifluoride or its complex can be used as the Lewis acid catalyst.


The structure of the chain end of the polymer having the structural unit represented by Formula (V) is not particularly limited, but for the group derived from the divinyl aromatic compound, examples of the chain end structure include a structure of Formula (E1) below. In Formula (E1), L1 is the same meaning as defined in Formula (V1) above, and * represents a bonding position.





*—CH═CH-L1-CH═CH2  (E1)


When the group derived from the monovinyl aromatic compound is at a chain end, examples of the chain end structure include a structure of Formula (E2) below. In the formula, L2 and RV1 each have the same meaning as defined in Formula (V4) above, and * represents a bonding position.





*—CH═CH-L2-RV1  (E2)


The molecular weight of the polymer having the structural unit represented by Formula (V) in terms of number average molecular weight Mn is preferably 300 or more, more preferably 500 or more, still more preferably 1000 or more, and further preferably 1500 or more. The upper limit is preferably 130000 or less, more preferably 120000 or less, even more preferably 110000 or less, and still more preferably 100000 or less.


The molecular weight of the polymer having the structural unit represented by Formula (V) in terms of weight average molecular weight Mw is preferably 3000 or more, more preferably 5000 or more, and still more preferably 10000 or more. When the molecular weight is equal to or higher than the lower limit, a cured product of the resin composition can effectively exhibit the excellent low dielectric properties, particularly the Df and the dielectric properties after moisture absorption, which are originally possessed by the polymer having the structural unit represented by Formula (V). The upper limit is preferably 130000 or less, more preferably 100000 or less, still more preferably 80000 or less, and even more preferably 50000 or less. When the molecular weight is equal to or lower than the above upper limit, an embedding defect tends to hardly occur when the prepreg or the resin sheet is laminated on a circuit-forming substrate.


The monodispersity represented by the ratio of weight average molecular weight Mw to number average molecular weight Mn (Mw/Mn) is preferably 100 or less, more preferably 50 or less, and even more preferably 20 or less. The lower limit is practically 1.1 or more, preferably 5 or more, more preferably 7 or more, and still more preferably 10 or more.


The above-described Mw and Mn are measured according to the description of Examples below.


When the resin composition of the present embodiment contains two or more polymers having the structural unit represented by Formula (V), the Mw, Mn, and Mw/Mn of the mixture preferably satisfy the ranges described above.


The vinyl group equivalent of the polymer having the structural unit represented by Formula (V) is preferably 200 g/eq. or more, more preferably 230 g/eq. or more, and still more preferably 250 g/eq. or more. The vinyl group equivalent is preferably 1200 g/eq. or less, and more preferably 1000 g/eq. or less, and further may be 800 g/eq. or less, 600 g/eq. or less, 400 g/eq. or less, or 300 g/eq. or less. When the vinyl group equivalent is equal to or higher than the lower limit, the storage stability of the resin composition tends to be improved, and the fluidity of the resin composition tends to be improved. Therefore, there is a tendency that moldability is improved, voids are less likely to occur at the time of forming a prepreg, and a printed wiring board having higher reliability is obtained. Meanwhile, when the vinyl group equivalent is equal to or lower than the above upper limit, the thermal resistance of the resulting cured product tends to be improved.


For the polymer having the structural unit represented by Formula (V) in the present specification, reference can be made to compounds, their synthesis conditions, and the like described in paragraphs [0029] to [0058] of WO 2017/115813, compounds, their synthesis conditions, and the like described in paragraphs [0013] to [0058] of JP 2018-039995 A, compounds, their synthesis conditions, and the like described in paragraphs [0008] to [0043] of JP 2018-168347 A, compounds, their synthesis conditions, and the like described in paragraphs [0014] to [0042] of JP 2006-070136 A, compounds, their synthesis conditions, and the like described in paragraphs [0014] to [0061] of JP 2006-089683 A, and compounds, their synthesis conditions, and the like described in paragraphs [0008] to [0036] of JP 2008-248001 A, the contents of which are incorporated herein by reference.


The lower limit of the content of the polymer having the structural unit represented by Formula (V) is more preferably 5 parts by mass or more, still more preferably 10 parts by mass or more, even more preferably 15 parts by mass or more, and further more preferably 20 parts by mass or more, when the resin solid content in the resin composition is defined as 100 parts by mass. Meanwhile, the upper limit of the content of the polymer having the structural unit represented by Formula (V) is preferably 60 parts by mass or less, more preferably 55 parts by mass or less, still more preferably 50 parts by mass or less, and even more preferably 45 parts by mass or less, when the resin solid content in the resin composition is defined as 100 parts by mass.


Maleimide Compound

The resin composition of the present embodiment may contain a maleimide compound.


The maleimide compound is not particularly limited as long as it is a compound having one or more (preferably from 2 to 12, more preferably from 2 to 6, still more preferably from 2 to 4, even more preferably 2 or 3, and further more preferably) maleimide groups per molecule. The maleimide compound can be selected from a wide variety of compounds commonly used in the field of printed wiring boards.


In the present embodiment, the maleimide compound preferably contains one or more selected from the group consisting of a compound represented by Formula (M0), a compound represented by Formula (M1), a compound represented by Formula (M2), a compound represented by Formula (M3), a compound represented by Formula (M4), a compound represented by Formula (M5), a maleimide compound (M6), and a maleimide compound (M7); more preferably contains one or more selected from the group consisting of a compound represented by Formula (M0), a compound represented by Formula (M1), a compound represented by Formula (M3), a compound represented by Formula (M4), a compound represented by Formula (M5), and a maleimide compound (M6); still more preferably contains one or more selected from the group consisting of a compound represented by Formula (M1), a compound represented by Formula (M3), a compound represented by Formula (M4), and a compound represented by Formula (M5); even more preferably contains one or more selected from the group consisting of a compound represented by Formula (M1), a compound represented by Formula (M3), and a compound represented by Formula (M5); further more preferably contains a compound represented by Formula (M1) and/or a compound represented by Formula (M3); and still further more preferably is a compound represented by Formula (M1). When such a maleimide compound is used in a material for a printed wiring board (for example, a metal foil-clad laminate), the material can be provided with excellent thermal resistance.




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(In Formula (M0), R51 each independently represents a hydrogen atom, an alkyl group having from 1 to 8 carbons, or a phenyl group; RS2 each independently represents a hydrogen atom or a methyl group; and n1 represents an integer of 1 or more.)


R51 is each independently preferably one selected from the group consisting of a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, and a phenyl group, more preferably a hydrogen atom and/or a methyl group, and still more preferably a hydrogen atom.


R52 is preferably a methyl group.


n1 is preferably an integer of from 1 to 10, more preferably an integer of from 1 to 5, still more preferably an integer of from 1 to 3, further preferably 1 or 2, and further still more preferably 1.


Specifically, the following compound is a preferred example of a compound represented by Formula (M0).




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In the above formula, R8 each independently represents a hydrogen atom, a methyl group, or an ethyl group, and a methyl group is preferred.


The compound represented by Formula (M0) may be one type, or a mixture of two or more types. Examples of such a mixture include a mixture of compounds having different n1, a mixture of compounds having different types of substituents of R51 and/or R52, a mixture of compounds having different bonding positions (meta-position, para-position, ortho-position) of a maleimide group and an oxygen atom with respect to a benzene ring, and a mixture of compounds having a combination of two or more different points described above. The same shall apply to compounds represented by Formulae (M1) to (M6).




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(In Formula (M1), RM1, RM2, RM3, and RM4 each independently represent a hydrogen atom or an organic group; RM1 and RM6 each independently represent a hydrogen atom or an alkyl group; Arm represents a divalent aromatic group; A is a four- to six-membered alicyclic group; RM7 and RM8 are each independently an alkyl group; mx is 1 or 2; lx is 0 or 1; RM9 and RM10 each independently represent a hydrogen atom or an alkyl group; RM11, RM12, RM13, and RM14 each independently represent a hydrogen atom or an organic group; RM15 each independently represents an alkyl group having from 1 to 10 carbons, an alkyloxy group having from 1 to 10 carbons, an alkylthio group having from 1 to 10 carbons, a cycloalkyl group having from 3 to 10 carbons, an aryl group having from 6 to 10 carbons, an aryloxy group having from 6 to 10 carbons, an arylthio group having from 6 to 10 carbons, a halogen atom, a hydroxyl group, or a mercapto group; px represents an integer of from 0 to 3; and nx represents an integer of from 1 to 20.)


RM1, RM2, RM3, and RM4 in the formula each independently represent a hydrogen atom or an organic group. The organic group here is preferably an alkyl group, more preferably an alkyl group having from 1 to 12 carbons, even more preferably an alkyl group having from 1 to 6 carbons, still more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group. RM1 and RM3 are each independently preferably an alkyl group, and RM2 and RM4 are preferably a hydrogen atom.


RM5 and RM6 each independently represent a hydrogen atom or an alkyl group, and are preferably an alkyl group. The alkyl group here is preferably an alkyl group having from 1 to 12 carbons, more preferably an alkyl group having from 1 to 6 carbons, even more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group.


ArM represents a divalent aromatic group and is preferably a phenylene group, a naphthalenediyl group, a phenanthrenediyl group, or an anthracenediyl group, more preferably a phenylene group, and even more preferably an m-phenylene group. ArM may have a substituent, and the substituent is preferably an alkyl group, more preferably an alkyl group having from 1 to 12 carbons, even more preferably an alkyl group having from 1 to 6 carbons, still more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group. However, Arm is preferably unsubstituted.


A is a four- to six-membered alicyclic group and more preferably a five-membered alicyclic group (preferably a group to form an indane ring with a benzene ring). RM7 and RM8 are each independently an alkyl group, preferably an alkyl group having from 1 to 6 carbons, more preferably an alkyl group having from 1 to 3 carbons, and particularly preferably a methyl group.


mx is 1 or 2 and preferably 2.


lx is 0 or 1 and preferably 1.


RM9 and RM10 each independently represent a hydrogen atom or an alkyl group, and are more preferably an alkyl group. The alkyl group here is preferably an alkyl group having from 1 to 12 carbons, more preferably an alkyl group having from 1 to 6 carbons, even more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group.


RM11, RM12, RM13, and RM14 each independently represent a hydrogen atom or an organic group. The organic group here is preferably an alkyl group, more preferably an alkyl group having from 1 to 12 carbons, even more preferably an alkyl group having from 1 to 6 carbons, still more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group. RM12 and RM13 are each independently preferably an alkyl group, and RM11 and RM14 are preferably a hydrogen atom.


RM15 each independently represents an alkyl group having from 1 to 10 carbons, an alkyloxy group having from 1 to 10 carbons, an alkylthio group having from 1 to 10 carbons, a cycloalkyl group having from 3 to 10 carbons, an aryl group having from 6 to 10 carbons, an aryloxy group having from 6 to 10 carbons, an arylthio group having from 6 to 10 carbons, a halogen atom, a hydroxyl group, or a mercapto group, and is preferably an alkyl group having from 1 to 4 carbons, a cycloalkyl group having from 3 to 6 carbons, or an aryl group having from 6 to 10 carbons.


px represents an integer of from 0 to 3, and is preferably an integer of from 0 to 2, more preferably 0 or 1, and even more preferably 0.


nx represents an integer of from 1 to 20. nx may be an integer of 10 or less.


The resin composition of the present embodiment may contain only one type or two or more types of compounds represented by Formula (M1) having different values of at least nx. When the resin composition contains two or more types of compounds, the average value (average repeating unit number) n of nx in the compound represented by Formula (M1) in the resin composition is preferably 0.92 or more, more preferably 0.95 or more, still more preferably 1.0 or more, and further preferably 1.1 or more in order to lower the melting point (softening point), reduce the melt viscosity, and provide excellent handling properties. Also, n is preferably 10.0 or less, more preferably 8.0 or less, even more preferably 7.0 or less, and still more preferably 6.0 or less, and may be 5.0 or less. The same shall apply to compounds represented by Formula (M1-2) and Formula (M1-3) described below.


The compound represented by Formula (M1) is preferably a compound represented by Formula (M1-1) below.




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(In Formula (M1-1), RM21, RM22, RM23, and RM24 each independently represent a hydrogen atom or an organic group; RM25 and RM26 each independently represent a hydrogen atom or an alkyl group; RM27, RM28, RM29, and RM30 each independently represent a hydrogen atom or an organic group; RM31 and RM32 each independently represent a hydrogen atom or an alkyl group; RM33, RM34, RM35, and RM36 each independently represent a hydrogen atom or an organic group; RM37, RM38, and RM39 each independently represent a hydrogen atom or an alkyl group; and nx represents an integer of 1 or more and 20 or less.)


RM21, RM22, RM23, and RM24 in the formula each independently represent a hydrogen atom or an organic group. The organic group here is preferably an alkyl group, more preferably an alkyl group having from 1 to 12 carbons, even more preferably an alkyl group having from 1 to 6 carbons, still more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group. RM21 and RM23 are preferably an alkyl group, and RM22 and RM24 are preferably a hydrogen atom.


RM25 and RM26 each independently represent a hydrogen atom or an alkyl group, and are preferably an alkyl group. The alkyl group here is preferably an alkyl group having from 1 to 12 carbons, more preferably an alkyl group having from 1 to 6 carbons, even more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group.


RM27, RM28, RM29, and RM30 each independently represent a hydrogen atom or an organic group and are preferably hydrogen atoms. The organic group here is preferably an alkyl group, more preferably an alkyl group having from 1 to 12 carbons, even more preferably an alkyl group having from 1 to 6 carbons, still more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group.


RM31 and RM32 each independently represent a hydrogen atom or an alkyl group, and are preferably an alkyl group. The alkyl group here is preferably an alkyl group having from 1 to 12 carbons, more preferably an alkyl group having from 1 to 6 carbons, even more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group.


RM33, RM34, RM35, and RM36 each independently represent a hydrogen atom or an organic group. The organic group here is preferably an alkyl group, more preferably an alkyl group having from 1 to 12 carbons, even more preferably an alkyl group having from 1 to 6 carbons, still more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group.


RM33 and RM36 are preferably a hydrogen atom, and RM34 and RM35 are preferably an alkyl group.


RM37, RM38, and RM39 each independently represent a hydrogen atom or an alkyl group, and are preferably an alkyl group. The alkyl group here is preferably an alkyl group having from 1 to 12 carbons, more preferably an alkyl group having from 1 to 6 carbons, even more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group.


nx represents an integer of 1 or more and 20 or less. nx may be an integer of 10 or less.


The compound represented by Formula (M1-1) is preferably a compound represented by Formula (M1-2) below.




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(In Formula (M1-2), RM21, RM22, RM23, and RM24 each independently represent a hydrogen atom or an organic group; RM25 and RM26 each independently represent a hydrogen atom or an alkyl group; RM27, RM28, RM29, and RM30 each independently represent a hydrogen atom or an organic group; RM31 and RM32 each independently represent a hydrogen atom or an alkyl group; RM33, RM34, RM35, and RM36 each independently represent a hydrogen atom or an organic group; RM37, RM38, and RM39 each independently represent a hydrogen atom or an alkyl group; and nx represents an integer of 1 or more and 20 or less.)


In Formula (M1-2), RM21, RM22, RM23, RM24, RM25, RM26, RM27, RM28, RM29, RM30, RM31, RM32, RM33, RM34, RM35, RM36, RM37, RM38, RM39, and nx have the same meanings as RM21, RM22, RM23, RM24, RM25, RM26, RM27, RM28, RM29, RM30, RM31, RM32, RM33, RM34, RM35, RM36, RM37, RM38, RM39, and nx in Formula (M1-1), respectively, and preferred ranges thereof are also the same.


The compound represented by Formula (M1-1) is preferably a compound represented by Formula (M1-3) below, and more preferably a compound represented by Formula (M1-4) below.




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(In Formula (M1-3), nx represents an integer of 1 or more and 20 or less.)


nx may be an integer of 10 or less.




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(In Formula (M1-4), nx represents an integer of 1 or more and 20 or less.)


nx may be an integer of 10 or less.


The molecular weight of the compound represented by Formula (M1) is preferably 500 or more, more preferably 600 or more, and still more preferably 700 or more. When the molecular weight is equal to or higher than the above lower limit, the low dielectric properties (Dk and/or Df) and the low water absorbability of the resulting cured product tend to be further improved. The molecular weight of the compound represented by Formula (M1) is preferably 10000 or less, more preferably 9000 or less, still more preferably 7000 or less, further preferably 5000 or less, and further still more preferably 4000 or less. When the molecular weight is equal to or lower than the above upper limit, the thermal resistance and handling properties of the resulting cured product tend to be further improved.


The compound represented by Formula (M1) has a maleimide group equivalent of preferably 50 g/eq. or more, more preferably 100 g/eq. or more, and still more preferably 200 g/eq. or more. The upper limit of the maleimide equivalent is preferably 2000 g/eq. or less, more preferably 1000 g/eq. or less, and still more preferably 800 g/eq. or less. Here, the maleimide group equivalent represents the mass of the maleimide compound per equivalent of the maleimide group. When the maleimide group equivalent of the compound represented by Formula (M1) falls within the above range, the low dielectric properties (Dk and/or Df), low water absorbability, thermal resistance, and handleability of the resulting cured product tend to be further improved.


The compound represented by Formula (M1) has a molecular weight distribution Mw/Mn as calculated by gel permeation chromatography (GPC) measurement of preferably 1.0 to 4.0, more preferably 1.1 to 3.8, still more preferably 1.2 to 3.6, and even more preferably 1.3 to 3.4. When the Mw/Mn of the compound represented by Formula (M1) falls within the above range, the low dielectric properties (Dk and/or Df), low water absorbability, thermal resistance, and handleability of the resulting cured product tend to be further improved.


In addition, for details of the compound represented by Formula (M1), reference can be made to the description of WO 2020-217679, the content of which is incorporated herein by reference.




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(In Formula (M2), R54 each independently represents a hydrogen atom or a methyl group; and n4 represents an integer of 1 or more.)


n4 is preferably an integer of from 1 to 10, more preferably an integer of from 1 to 5, still more preferably an integer of from 1 to 3, further preferably 1 or 2, and may be 1.


The compound represented by Formula (M2) may be a mixture of compounds differing in n4, and is preferably the mixture. It may be a mixture of compounds differing in other portions as described for the compound represented by Formula (M0).




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(In Formula (M3), R55 each independently represents a hydrogen atom, an alkyl group having from 1 to 8 carbons, or a phenyl group; and n5 represents an integer of 1 or more and 10 or less.)


R55 is each independently preferably one selected from the group consisting of a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, or a phenyl group, more preferably a hydrogen atom and/or a methyl group, and still more preferably a hydrogen atom.


n5 is preferably an integer from 1 to 5, more preferably an integer from 1 to 3, and even more preferably 1 or 2.


The compound represented by Formula (M3) may be a mixture of compounds differing in n5, and is preferably the mixture. It may be a mixture of compounds differing in other portions as described for the compound represented by Formula (M0).




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(In Formula (M4), R56 each independently represents a hydrogen atom, a methyl group, or an ethyl group, and R57 each independently represents a hydrogen atom or a methyl group.)


R56 is each independently preferably a methyl group or an ethyl group, more preferably a methyl group or an ethyl group in each of the two benzene rings, and R57 is preferably a methyl group.




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(In Formula (M5), R58 each independently represents a hydrogen atom, an alkyl group having from 1 to 8 carbons, or a phenyl group; R9 each independently represents a hydrogen atom or a methyl group; and n6 represents an integer of 1 or more.)


R58 is each independently preferably one selected from the group consisting of a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, and a phenyl group, more preferably a hydrogen atom and/or a methyl group, and still more preferably a hydrogen atom.


R59 is preferably a methyl group.


n6 is preferably an integer of from 1 to 10, more preferably an integer of from 1 to 5, even more preferably an integer of from 1 to 3, and still more preferably 1 or 2, and may be 1.


The compound represented by Formula (M5) may be a mixture of compounds differing in n6, and is preferably the mixture. It may be a mixture of compounds differing in other portions as described for the compound represented by Formula (M0).


The maleimide compound (M6) is a compound having a structural unit represented by Formula (M6) and maleimide groups at both terminals of the molecular chain.




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(In Formula (M6), R61 represents a linear or branched alkylene group having from 1 to 16 carbons, or a linear or branched alkenylene group having from 2 to 16 carbons; R62 represents a linear or branched alkylene group having from 1 to 16 carbons, or a linear or branched alkenylene group having from 2 to 16 carbons; R63 each independently represents a linear or branched alkyl group having from 1 to 16 carbons or a linear or branched alkenyl group having from 2 to 16 carbons; and n each independently represents an integer of 0 to 10.)


For details of the maleimide compound (M6) and a method for producing the maleimide compound, reference can be made to the description in paragraphs [0061] to [0066] of WO 2020/262577, the content of which is incorporated herein by reference.


The maleimide compound (M7) is a maleimide compound formed from reaction raw materials (1); i.e., an aromatic amine compound (a1) having one or more and three or less alkyl groups in an aromatic ring, an aromatic divinyl compound (a2) having two ethenyl groups, and maleic anhydride.


The maleimide compound (M7) is preferably a compound represented by Formula (M7).




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(In Formula (M7) above, R1 each independently represents the alkyl group, R2 each independently represents an alkyl, alkoxy, or alkylthio group having from 1 to 10 carbons; an aryl, aryloxy, or arylthio group having from 6 to 10 carbons; a cycloalkyl group having from 3 to 10 carbons; a halogen atom; a hydroxyl group; or a mercapto group;

    • R3, R4, R5 and R6 each independently represent a hydrogen atom or a methyl group; one of R3 and R4 is a hydrogen atom; the other is a methyl group; one of R5 and R6 is a hydrogen atom; the other is a methyl group; and
    • X1 represents a substituent represented by Formula (x) below:




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(in Formula (x), R7 and R8 each independently represent a hydrogen atom or a methyl group; one of R7 and R8 is a hydrogen atom; the other is a methyl group; R9 each independently represents an alkyl, alkoxy, or alkylthio group having from 1 to 10 carbons; an aryl, aryloxy, or arylthio group having from 6 to 10 carbons; a cycloalkyl group having from 3 to 10 carbons; a halogen atom; a hydroxyl group; or a mercapto group; and t represents an integer of 0 to 4);

    • r represents an average value of the number of substituents of X1 per one benzene ring to which X1 is bonded and a number of 0 to 4, p represents an integer of 1 to 3, q represents an integer of 0 to 4, and k represents an integer of 1 to 100.)


For details of the polymaleimide compound (M7) used in the present embodiment, reference can be made to the description of JP 7160151 B, the content of which is incorporated herein by reference.


The maleimide compound may be produced by a known method, or may be a commercially available product. For the commercially available product, examples of the compound represented by Formula (M0) include “BMI-80” available from K—I Chemical Industry Co., Ltd., examples of the compound represented by Formula (M1) include “NE-X-9470S” available from DIC Corporation, examples of the compound represented by Formula (M2) include “BMI-2300” available from Daiwa Kasei Industry Co., Ltd., examples of the compound represented by Formula (M3) include “MIR-3000-70MT” available from Nippon Kayaku Co., Ltd., examples of the compound represented by Formula (M4) include “BMI-70” available from K—I Chemical Industry Co., Ltd., examples of the compound represented by Formula (M5) include “MIR-5000” available from Nippon Kayaku Co., Ltd., examples of the maleimide compound (M6) include “MIZ-001” available from Nippon Kayaku Co., Ltd., and examples of the maleimide compound (M7) include “NE-X-9500” available from DIC Corporation.


Examples of the maleimide compound other than those described above include oligomers of N-phenylmaleimide, N-cyclohexylmaleimide, or phenylmethane maleimide, m-phenylene bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 1,6-bismaleimide-(2,2,4-trimethyl)hexane, 4,4′-diphenylether bismaleimide, 4,4′-diphenylsulfone bismaleimide, 1,3-bis(3-maleimidophenoxy)benzene, 1,3-bis(4-maleimidophenoxy)benzene, and prepolymers of these, and prepolymers of such a maleimide and an amine.


In particular, a monofunctional maleimide compound such as N-phenylmaleimide or N-cyclohexylmaleimide tends to be used in combination with a polymer having a structural unit represented by Formula (V) below to yield a resin composition capable of providing a cured product having more excellent low dielectric properties.


When the resin composition of the present embodiment contains a maleimide compound, the lower limit of the content of the maleimide compound is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, still more preferably 20 parts by mass or more, and yet still more preferably 25 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the maleimide compound is 1 part by mass or more, the flame resistance of the resulting cured product tends to be improved. The upper limit of the content of the maleimide compound is preferably 70 parts by mass or less, and more preferably 50 parts by mass or less, and may be 40 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the maleimide compound is 70 parts by mass or less, the metal foil peel strength and low water absorbability of the resulting cured product tend to be improved.


The resin composition of the present embodiment may contain only one type or two or more types of maleimide compounds. When two or more types of maleimide compounds are contained, the total amount thereof preferably falls within the above range.


The resin composition of the present embodiment may contain substantially no maleimide compound. The phrase “contain substantially no maleimide compound” means that the content of the maleimide compound is less than 1 part by mass relative to 100 parts by mass of the resin solid content in the resin composition, and the content is preferably less than 0.1 parts by mass, and more preferably less than 0.01 parts by mass.


Cyanate Ester Compound

The resin composition of the present embodiment may contain a cyanate ester compound.


The cyanate ester compound is not particularly limited as long as the compound contains one or more (preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, even more preferably 2 or 3, and further more preferably 2) cyanate groups (cyanato groups) per molecule, and can be selected from a wide variety of compounds commonly used in the field of printed wiring boards.


The cyanate ester compound is preferably a cyanate ester compound that is commonly used in a printed wiring board and contains two or more aromatic moieties per molecule, each of the aromatic moieties being substituted with at least one cyanato group.


Specifically, the lower limit of the number of cyanato groups contained in the cyanate ester compound is preferably 2 or more and more preferably 3 or more. When the number of cyanato groups is equal to or more than the above lower limit, the thermal resistance tends to be further improved. The upper limit of the number of cyanato groups is preferably 100 or less, and more preferably 50 or less.


Preferably, a cured product of the cyanate ester compound has excellent low dielectric properties (Dk and/or Df). For example, the cured product of the cyanate ester compound has a dielectric constant (Dk) at a frequency of 10 GHz as measured according to a cavity resonator perturbation method of preferably 4.0 or less and more preferably of 3.5 or less. The lower limit of the dielectric constant is, for example, practically 2.0 or higher. The cured product of the cyanate ester compound (B) has a dielectric loss tangent (Df) at a frequency of 10 GHz as measured according to a cavity resonator perturbation method of preferably 0.02 or less and more preferably of 0.015 or less. The lower limit of the dielectric loss tangent is, for example, practically 0.0001 or higher. The dielectric constant and the dielectric loss tangent can be measured according to, for example, the method described in Examples (curing conditions, measurement conditions).


Preferably, the cured product of the cyanate ester compound has high thermal resistance. The cured product of the cyanate ester compound has a glass transition temperature as measured according to the JIS C 6481 dynamic viscoelasticity measurement of preferably 150° C. or higher, more preferably 180° C. or higher, and still more preferably 200° C. or higher. When the glass transition temperature is equal to or higher than the above lower limit, a cured product having excellent thermal resistance is obtained.


The cyanate ester compound has a weight average molecular weight in terms of polystyrene measured by the GPC method of preferably 200 or more, more preferably 300 or more, and still more preferably 400 or more. When the weight average molecular weight is equal to or higher than the above lower limit, the thermal resistance tends to be further improved. The weight average molecular weight of the cyanate ester compound is preferably 1000 or less, more preferably 900 or less, and still more preferably 800 or less. When the weight average molecular weight is equal to or lower than the above upper limit, the moldability and the handling properties tend to be further improved.


For preferred cyanate ester compounds, reference can be made to paragraphs [0028] to [0033] of WO 2021/172317, the content of which is incorporated herein by reference.


Preferred examples of the cyanate ester compound include at least one selected from the group consisting of phenol novolac-type cyanate ester compounds, naphthol aralkyl-type cyanate ester compounds (naphthol aralkyl-type cyanates), naphthylene ether-type cyanate ester compounds, biphenyl aralkyl-type cyanate ester compounds, xylene resin-type cyanate ester compounds, trisphenol methane-type cyanate ester compounds, adamantane skeleton-type cyanate ester compounds, bisphenol M-type cyanate ester compounds, and bisphenol A-type cyanate ester compounds. Among them, from the viewpoint of further improving the low water absorbability, the cyanate ester compound is preferably at least one selected from the group consisting of phenol novolac-type cyanate ester compounds, naphthol aralkyl-type cyanate ester compounds, naphthylene ether-type cyanate ester compounds, xylene resin-type cyanate ester compounds, bisphenol M-type cyanate ester compounds, and bisphenol A-type cyanate ester compounds, more preferably at least one selected from the group consisting of phenol novolac-type cyanate ester compounds, naphthol aralkyl-type cyanate ester compounds, naphthylene ether-type cyanate ester compounds, bisphenol A-type cyanate ester compounds, and bisphenol M-type cyanate ester compounds, still more preferably at least one selected from the group consisting of phenol novolac-type cyanate ester compounds, naphthol aralkyl-type cyanate ester compounds, and bisphenol A-type cyanate ester compounds, even more preferably a naphthol aralkyl-type cyanate ester compound and/or a bisphenol A-type cyanate ester compound, and further more preferably a naphthol aralkyl-type cyanate ester compound.


The naphthol aralkyl-type cyanate ester compound is more preferably a compound represented by Formula (N1).




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(In Formula (N1), R3 each independently represents a hydrogen atom or a methyl group, and n3 represents an integer of 1 or more.)


In Formula (N1), R3 each independently represents a hydrogen atom or a methyl group, and is preferably a hydrogen atom among these.


In Formula (N1), n3 is an integer of 1 or more, preferably an integer of 1 to 50, more preferably an integer of 1 to 20, still more preferably an integer of 1 to 10, and even more preferably an integer of 1 to 6.


The phenol novolac-type cyanate ester compound is not particularly limited, and, for example, is preferably a compound represented by Formula (VII).




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(In Formula (VII), R6 each independently represents a hydrogen atom or a methyl group; and n7 represents an integer of 1 or more.)


In Formula (VII), R6 each independently represents a hydrogen atom or a methyl group, and is preferably a hydrogen atom among these.


In Formula (Vii), n7 is an integer of 1 or more, and preferably an integer of from 1 to 20, more preferably an integer of from 1 to 10, and even more preferably an integer of from 1 to 6.


The bisphenol A-type cyanate ester compound used may be one or more selected from the group consisting of 2,2-bis(4-cyanatophenyl)propane and a prepolymer of 2,2-bis(4-cyanatophenyl)propane.


Such a cyanate ester compound may be prepared by a known method, or a commercially available product may be used. A cyanate ester compound having a naphthol aralkyl skeleton, a naphthylene ether skeleton, a xylene skeleton, a trisphenol methane skeleton, or an adamantane skeleton has a relatively large functional group equivalents and a small number of unreacted cyanate ester groups, and thus the resin composition formed using such a cyanate ester compound tends to have even better low water absorbability. In addition, the plating adhesion tends to be further improved mainly due to having an aromatic skeleton or an adamantane skeleton.


When the resin composition of the present embodiment contains a cyanate ester compound, the cyanate ester compound is preferably contained in such an amount that the effects of the present invention are not impaired. When the resin composition of the present embodiment contains a cyanate ester compound, the lower limit of the content of the cyanate ester compound is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and even more preferably 7 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the cyanate ester compound is 1 part by mass or more, the thermal resistance, combustion resistance, chemical resistance, and insulation of the resulting cured product tend to be improved. When the resin composition of the present embodiment contains a cyanate ester compound, the upper limit of the content of the cyanate ester compound is preferably 70 parts by mass or less, more preferably 50 parts by mass or less, even more preferably 40 parts by mass or less, still more preferably 30 parts by mass or less, yet still more preferably 20 parts by mass or less, and further preferably 15 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition.


The resin composition of the present embodiment may contain only one type of cyanate ester compound or may contain two or more types of cyanate ester compounds. When two or more types of cyanate ester compounds are contained, the total amount thereof preferably falls within the above range.


The resin composition of the present embodiment may contain substantially no cyanate ester compound. The phrase “contain substantially no” means that the content of the cyanate ester compound is less than 1 part by mass relative to 100 parts by mass of the resin solid content in the resin composition, and the content is preferably less than 0.1 parts by mass, and more preferably less than 0.01 parts by mass.


Epoxy Compound

The resin composition of the present embodiment may contain an epoxy compound.


The epoxy compound is not particularly limited as long as it is a compound or resin having one or more (preferably from 2 to 12, more preferably from 2 to 6, even more preferably from 2 to 4, still more preferably 2 or 3, and yet more preferably 2) epoxy groups per molecule, and can be selected from a wide variety of compounds commonly used in the field of printed wiring boards.


Examples of the epoxy compound include bisphenol A-type epoxy resins, bisphenol E-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, phenol novolac-type epoxy resins, bisphenol A novolac-type epoxy resins, glycidyl ester-type epoxy resins, aralkyl novolac-type epoxy resins, biphenyl aralkyl-type epoxy resins, naphthylene ether-type epoxy resins, cresol novolac-type epoxy resins, multifunctional phenol-type epoxy resins, naphthalene-type epoxy resins, anthracene-type epoxy resins, naphthalene skeleton-modified novolac-type epoxy resins, phenol aralkyl-type epoxy resins, naphthol aralkyl-type epoxy resins, dicyclopentadiene-type epoxy resins, biphenyl-type epoxy resins, alicyclic epoxy resins, polyol-type epoxy resins, phosphorus-containing epoxy resins, glycidyl amine, glycidyl ester, compounds obtained by epoxidation of a double bond of butadiene, and compounds obtained by reaction of a hydroxyl group-containing silicone resin with epichlorohydrin. The use of such a compound improves the moldability and adhesion of the resin composition. Among these, the epoxy compound is preferably a biphenyl aralkyl-type epoxy resin, a naphthylene ether-type epoxy resin, a multifunctional phenol-type epoxy resin, or a naphthalene-type epoxy resin, and more preferably a biphenyl aralkyl-type epoxy resin, from the viewpoint of further improving the flame resistance and thermal resistance.


The resin composition of the present embodiment preferably contains the epoxy compound to such an extent that the effects of the present invention are not impaired. When the resin composition of the present embodiment contains the epoxy compound, the content of the epoxy compound is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and still more preferably 2 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition, from the viewpoint of the moldability and the adhesion. When the content of the epoxy compound is 0.1 parts by mass or more, the metal foil peel strength and toughness tend to be improved. When the resin composition of the present embodiment contains the epoxy compound, the upper limit of the content of the epoxy compound is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, still more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less, and may be 8 parts by mass or less or 5 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the epoxy compound is 50 parts by mass or less, the electrical properties of the resulting cured product tend to be improved.


The resin composition of the present embodiment may contain only one type of epoxy compound or may contain two or more types of epoxy compounds. When two or more types of epoxy compounds are contained, the total amount thereof preferably falls within the above range.


In addition, the resin composition of the present embodiment may contain substantially no epoxy compound. The phrase “contain substantially no” means that the content of the epoxy compound is less than 0.1 parts by mass relative to 100 parts by mass of the resin solid content in the resin composition, and the content is preferably less than 0.01 parts by mass and may be less than 0.001 parts by mass.


Phenol Compound

The resin composition of the present embodiment may contain a phenol compound.


For details of the phenol resin, reference can be made to the description in paragraph [0049] of WO 2021/172317, the content of which is incorporated herein by reference.


The resin composition of the present embodiment preferably contains the phenol compound to such an extent that the effects of the present invention are not impaired. When the resin composition of the present embodiment contains the phenol compound, the content of the phenol compound is preferably 0.1 parts by mass or more and preferably 50 parts by mass or less relative to 100 parts by mass of the resin solid content in the resin composition.


The resin composition of the present embodiment may contain only one phenol compound or may contain two or more phenol compounds. When two or more types of phenol compounds are contained, the total amount thereof preferably falls within the above range.


In addition, the resin composition of the present embodiment may contain substantially no phenol compound. The phrase “contain substantially no” means that the content of the phenol compound is less than 0.1 parts by mass relative to 100 parts by mass of the resin solid content in the resin composition.


Compound Containing (Meth)Allyl Group

The resin composition of the present embodiment preferably contains a compound containing a (meth)allyl group, and more preferably contains a compound containing an allyl group.


The compound containing a (meth)allyl group is preferably a compound containing two or more (meth)allyl groups, and more preferably a compound containing two or more allyl groups.


The compound containing a (meth)allyl group preferably contains at least one selected from the group consisting of a (meth)allyl isocyanurate compound, a tri(meth)allyl cyanurate compound, a (meth)allyl group-substituted nadiimide compound, a (meth)allyl compound having a glycoluril structure, and diallyl phthalate, more preferably contains at least one selected from the group consisting of a (meth)allyl isocyanurate compound, a (meth)allyl group-substituted nadiimide compound, and a (meth)allyl compound having a glycoluril structure, still more preferably contains a (meth)allyl isocyanurate compound and/or a (meth)allyl group-substituted nadiimide compound, and even more preferably contains a (meth)allyl group-substituted nadiimide compound.


Examples of the tri(meth)allyl cyanurate compound include a tri(meth)allyl cyanurate compound (for example, triallyl cyanurate having the following structure).




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Examples of the compound containing a (meth)allyl group include a resin having an allyl group described in WO 2022/210095 (for example, compounds described in Synthesis Examples 3, 4, 6, 20, and 22 of the same publication), the content of which is incorporated herein by reference.


When the resin composition of the present embodiment contains a compound containing a (meth)allyl group, the molecular weight thereof is preferably 195 or more, more preferably 300 or more, still more preferably 400 or more, and even more preferably 500 or more. When the molecular weight is equal to or higher than the above lower limit, the low dielectric properties and the thermal resistance tend to be further improved. The molecular weight of the compound containing a (meth)allyl group is preferably 3000 or less, more preferably 2000 or less, still more preferably 1000 or less, and even more preferably 800 or less. When the molecular weight is equal to or lower than the above upper limit, the low thermal expansion tends to be further improved.


When the resin composition of the present embodiment contains a compound containing a (meth)allyl group, the content of the compound is preferably 1 part by mass or more, more preferably 3 parts by mass or more, still more preferably 5 parts by mass or more, and may be 10 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the compound containing a (meth)allyl group is equal to or higher than the above lower limit, the moldability tends to be excellent, and the thermal resistance tends to be further improved. The upper limit of the content of the compound containing a (meth)allyl group is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and still more preferably 20 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the compound containing a (meth)allyl group is equal to or lower than the above upper limit, the low thermal expansion tends to be further improved.


The resin composition of the present embodiment may contain only one compound containing a (meth)allyl group, or may contain two or more compounds containing a (meth)allyl group. When two or more types of such compounds are contained, the total amount thereof preferably falls within the above range.


(Meth)Allyl Isocyanurate Compound

The (meth)allyl isocyanurate compound is not particularly limited as long as it is a compound having two or more (meth)allyl groups and having an isocyanurate ring (nurate skeleton). Since the (meth)allyl isocyanurate compound has a large number of (meth)allyl groups as crosslinking points, the (meth)allyl isocyanurate compound tends to be firmly cured together with the resin (A), the polyphenylene ether compound (B), and an additional resin component, so that a cured product having excellent low dielectric properties (Dk and/or Df) and thermal resistance is produced. The (meth)allyl isocyanurate compound is preferably a compound represented by Formula (TA).




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(In Formula (TA), RA represents a substituent.)


In Formula (TA), RA represents a substituent, and is more preferably a substituent having a formula weight of 15 to 500.


A first example of RA is an alkyl group having from 1 to 22 carbons or an alkenyl group having from 2 to 22 carbons. By using an allyl compound having an alkyl group having from 1 to 22 carbons or an alkenyl group having from 2 to 22 carbons, it is possible to provide a resin composition capable of producing a cured product having excellent crosslinkability and high toughness. As a result, even when a substrate such as glass cloth is not contained in the resin composition, it is possible to suppress cracking during etching treatment or the like.


The number of carbons in the alkyl group and/or the alkenyl group is preferably 3 or more, and more preferably 8 or more, and may be further 12 or more or 18 or less from the viewpoint of improving handleability. It is considered that the resin flowability of the resin composition is accordingly improved, and circuit filling properties are more excellent when a multilayer circuit board or the like is produced using the resin composition of the present embodiment.


A second example of RA is a group containing an allyl isocyanurate group. When RA contains an allyl isocyanurate group, the compound represented by Formula (TA) is preferably a compound represented by Formula (TA-1).




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(In Formula (TA-1), RA2 is a divalent linking group.)


In Formula (TA-1), RA2 is preferably a divalent linking group having a formula weight of 54 to 250, more preferably a divalent linking group having a formula weight of 54 to 250 and having carbon atoms at both terminals, and still more preferably an aliphatic hydrocarbon group having from 2 to 20 carbons (note: the aliphatic hydrocarbon group may contain an ether group or may have a hydroxyl group). More specifically, RA is preferably a group represented by any one of Formulae (i) to (iii) below.




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(In Formulae (i) to (iii), pc1 represents the number of repeating units of a methylene group, and is an integer of 2 to 18; pc2 represents the number of repeating units of an oxyethylene group and is 0 or 1; and * is a bonding site.)


The pc1 is preferably an integer of 2 to 10, more preferably an integer of 3 to 8, and still more preferably an integer of 3 to 5.


The pc2 may be 0 or 1, and is preferably 1.


A third example of RA is a phosphorus-based substituent.


RA2 is preferably the first example.


In the present embodiment, the reactive group (allyl group) equivalent of the compound represented by Formula (TA) is preferably 1000 g/eq. or less. When the equivalent is 1000 g/eq. or less, it is considered that a high Tg can be more reliably obtained.


Examples of the alkyl group having from 1 to 22 carbons include linear or branched alkyl groups, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, an eicosyl group, and a docosyl group. Examples of the alkenyl group having from 2 to 22 carbons include an allyl group and a decenyl group.


Specific examples of the compound represented by Formula (TA) include triallyl isocyanurate, 5-octyl-1,3-diallyl isocyanurate, 5-dodecyl-1,3-diallyl isocyanurate, 5-tetradecyl-1,3-diallyl isocyanurate, 5-hexadecyl-1,3-diallyl isocyanurate, 5-octadecyl-1,3-diallyl isocyanurate, 5-eicosyl-1,3-diallyl isocyanurate, 5-docosyl-1,3-diallyl isocyanurate, and 5-decenyl-1,3-diallyl isocyanurate. These may be used singly or in combination of two or more types thereof, or may be used as a prepolymer.


The method of producing the compound represented by Formula (TA) is not particularly limited, and for example, the compound can be produced by reacting diallyl isocyanurate and an alkyl halide in an aprotic polar solvent such as N,N′-dimethylformamide in the presence of a basic substance such as sodium hydroxide, potassium carbonate, or triethylamine at a temperature of about 60° C. to 150° C.


The compound represented by Formula (TA) may also be a commercially available compound. The commercially available product is not particularly limited, and examples thereof include L-DAIC available from Shikoku Chemicals Corporation and P-DAIC having a phosphorus-based substituent available from Shikoku Chemicals Corporation. Examples of the triallyl isocyanurate include TAIC available from Shinryo Corporation. Examples of the compound represented by Formula (TA-1) include DD-1 available from Shikoku Chemicals Corporation.


The molecular weight of the (meth)allyl isocyanurate compound (preferably, the compound represented by Formula (TA)) is preferably 200 or more, more preferably 300 or more, still more preferably 400 or more, and even more preferably 500 or more. When the molecular weight is equal to or higher than the above lower limit, the low dielectric properties (Dk and/or Df) and the thermal resistance of the resulting cured product tend to be further improved. The molecular weight of the (meth)allyl isocyanurate compound (preferably, the compound represented by Formula (TA)) is preferably 3000 or less, more preferably 2000 or less, still more preferably 1000 or less, and even more preferably 800 or less. When the molecular weight is equal to or lower than the above upper limit, the low thermal expansion of the resulting cured product tends to be further improved.


When the resin composition of the present embodiment contains a (meth)allyl isocyanurate compound, the content of the compound is preferably 1 part by mass or more, more preferably 3 parts by mass or more, still more preferably 5 parts by mass or more, and may be 10 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the (meth)allyl isocyanurate compound is equal to or higher than the above lower limit, the resin composition tends to have excellent moldability, and the thermal resistance and low thermal expansion of the resulting cured product tend to be further improved. The upper limit of the content of the (meth)allyl isocyanurate compound is preferably 40 parts by mass or less, and more preferably 30 parts by mass or less, and may be 20 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the (meth)allyl isocyanurate compound is equal to or lower than the above upper limit, the thermal resistance and low dielectric properties (Dk and/or Df) of the resulting cured product tend to be further improved.


The resin composition of the present embodiment may contain only one (meth)allyl isocyanurate compound, or may contain two or more (meth)allyl isocyanurate compounds. When two or more types of (meth)allyl isocyanurate compounds are contained, the total amount thereof preferably falls within the above range.


(Meth)Allyl Group-Substituted Nadiimide Compound

The (meth)allyl group-substituted nadiimide compound is not particularly limited as long as it is a compound having two or more (meth)allyl group-substituted nadiimide groups per molecule. Specific examples thereof include a compound represented by Formula (AN) below.




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(In Formula (AN), R1 each independently represents a hydrogen atom or an alkyl group having from 1 to 6 carbons, and R2 represents an alkylene group having from 1 to 6 carbons, a phenylene group, a biphenylene group, a naphthylene group, or a group represented by Formula (AN-2) or (AN-3).)




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(In Formula (AN-2), R3 represents a methylene group, an isopropylidene group, or a group represented by —C(═O), —O—, —S—, or —S(═O)2—.)




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(In Formula (AN-3), R4 each independently represents an alkylene group having from 1 to 4 carbons or a cycloalkylene group having from 5 to 8 carbons.)


The compound represented by Formula (AN) may also be a commercially available compound. Examples of the commercially available product include, but are not particularly limited to, a compound represented by Formula (AN-4) (BANI-M (available from Maruzen Petrochemical Co., Ltd.)) and a compound represented by Formula (AN-5) (BANI-X (available from Maruzen Petrochemical Co., Ltd.)). One of these may be used, or two or more may be used in combination.




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The molecular weight of the (meth)allyl group-substituted nadiimide compound (preferably, the compound represented by Formula (AN)) is preferably 400 or more, more preferably 500 or more, and may be 550 or more. When the molecular weight of the (meth)allyl group-substituted nadiimide compound is equal to or higher than the above lower limit, the low dielectric properties, the low thermal expansion, and the thermal resistance tend to be further improved. The molecular weight of the (meth)allyl group-substituted nadiimide compound (preferably the compound represented by Formula (AN)) is preferably 1500 or less, more preferably 1000 or less, and still more preferably 800 or less, and may be 700 or less or 600 or less. When the molecular weight of the (meth)allyl group-substituted nadiimide compound is equal to or lower than the above upper limit, moldability and peel strength tend to be further improved.


When the resin composition of the present embodiment contains the (meth)allyl group-substituted nadiimide compound (preferably the compound represented by Formula (AN)), the content of the compound is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and still more preferably 5 parts by mass or more, and may be 10 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the (meth)allyl group-substituted nadiimide compound is equal to or higher than the above lower limit, the moldability tends to be excellent, and the low dielectric properties, the low thermal expansion, and the thermal resistance tend to be further improved. The upper limit of the content of the (meth)allyl group-substituted nadiimide compound (preferably, the compound represented by Formula (AN)) is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and still more preferably 25 parts by mass or less, and may be 20 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the (meth)allyl group-substituted nadiimide compound is equal to or lower than the above upper limit, the moldability and the peel strength tend to be further improved.


The resin composition of the present embodiment may contain only one (meth)allyl group-substituted nadiimide compound, or may contain two or more (meth)allyl group-substituted nadiimide compounds. When two or more types of (meth)allyl group-substituted nadiimide compounds are contained, the total amount thereof preferably falls within the above range.


(Meth)Allyl Compound Having Glycoluril Structure

The (meth)allyl compound having a glycoluril structure is not particularly limited as long as it is a compound containing a glycoluril structure and two or more (meth)allyl groups. Even when the (meth)allyl compound having a glycoluril structure is blended in the resin composition, the number of (meth)allyl groups can be increased, that is, the number of crosslinking points can be increased. Thus, similarly to the case of the (meth)allyl isocyanurate compound, the (meth)allyl compound having a glycoluril structure tends to be firmly cured together with the resin (A), the polyphenylene ether compound (B), and an additional resin component, so that a cured product having excellent low dielectric properties (Dk and/or Df) and thermal resistance is produced.


In the present embodiment, the (meth)allyl compound having a glycoluril structure is preferably a compound represented by Formula (GU).




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(In Formula (GU), each R is independently a hydrogen atom or a substituent, and at least two of the groups represented by R contain a (meth)allyl group.)


In Formula (GU), each R is independently preferably a hydrogen atom, an alkyl group having from 1 to 5 carbons, or an alkenyl group having from 2 to 5 carbons, preferably an alkenyl group having from 2 to 5 carbons, more preferably a (meth)allyl group, and still more preferably an allyl group.


In Formula (GU), preferably, three or four of Rs are groups containing a (meth)allyl group, and more preferably, four of Rs are groups containing a (meth)allyl group.


Specific examples of the compound represented by Formula (GU) include 1,3,4,6-tetraallylglycoluril (compound of Formula (GU) in which all Rs are allyl groups).


The compound represented by Formula (GU) may also be a commercially available compound. The commercially available product is not particularly limited, and examples thereof include TA-G available from Shikoku Chemicals Corporation.


The molecular weight of the (meth)allyl compound having a glycoluril structure (preferably, the compound represented by Formula (GU)) is preferably 195 or more, more preferably 220 or more, and still more preferably 250 or more, and may be 300 or more or 400 or more. When the molecular weight of the (meth)allyl compound having a glycoluril structure is equal to or higher than the above lower limit, the thermal resistance and low thermal expansion of the resulting cured product tend to be further improved. The molecular weight of the (meth)allyl compound having a glycoluril structure (preferably, the compound represented by Formula (GU)) is preferably 1500 or less, more preferably 1000 or less, still more preferably 800 or less, and may be 700 or less or 600 or less. When the molecular weight of the (meth)allyl compound having a glycoluril structure is equal to or lower than the above upper limit, the low dielectric properties (Dk and/or Df) and the thermal resistance of the resulting cured product tend to be further improved.


When the resin composition of the present embodiment contains the (meth)allyl compound having a glycoluril structure (preferably, the compound represented by Formula (GU)), the content of the compound is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and still more preferably 5 parts by mass or more, and may be 10 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the (meth)allyl compound having a glycoluril structure is equal to or higher than the above lower limit, the resin composition tends to have excellent moldability, and the thermal resistance and low thermal expansion of the resulting cured product tend to be further improved. The upper limit of the content of the (meth)allyl compound having a glycoluril structure (preferably, the compound represented by Formula (GU)) is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and still more preferably 25 parts by mass or less, and may be 20 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the (meth)allyl compound having a glycoluril structure is equal to or lower than the above upper limit, the low dielectric properties (Dk and/or Df) of the resulting cured product tend to be further improved.


The resin composition of the present embodiment may contain only one (meth)allyl compound having a glycoluril structure, or may contain two or more (meth)allyl compounds having a glycoluril structure. When two or more types of (meth)allyl compounds having a glycoluril structure are contained, the total amount thereof preferably falls within the above range.


Oxetane Resin

The resin composition of the present embodiment may contain an oxetane resin.


The oxetane resin is not particularly limited as long as it is a compound having one or more (preferably from 2 to 12, more preferably from 2 to 6, even more preferably from 2 to 4, still more preferably 2 or 3, and yet more preferably 2) oxetanyl groups, and can be selected from a wide variety of compounds commonly used in the field of printed wiring boards.


Examples of the oxetane resin include oxetane, alkyloxetanes (e.g., 2-methyloxetane, 2,2-dimethyloxetane, 3-methyloxetane, and 3,3-dimethyloxatane), 3-methyl-3-methoxymethyloxetane, 3,3-di(trifluoromethyl)oxetane, 2-chloromethyloxetane, 3,3-bis(chloromethyl)oxetane, biphenyl-type oxetane, OXT-101 (available from Toagosei Co., Ltd.), and OXT-121 (available from Toagosei Co., Ltd.).


The resin composition of the present embodiment preferably contains the oxetane resin to such an extent that the effects of the present invention are not impaired. When the resin composition of the present embodiment contains the oxetane resin, the content of the oxetane resin is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 2 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the oxetane resin is 0.1 parts by mass or more, the metal foil peel strength and toughness of the resulting cured product tend to be improved. When the resin composition of the present embodiment contains the oxetane resin, the upper limit of the content of the oxetane resin is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, still more preferably 10 parts by mass or less, and yet more preferably 8 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the oxetane resin is 50 parts by mass or less, the electrical properties of the resulting cured product tend to be improved.


The resin composition of the present embodiment may contain only one oxetane resin or may contain two or more oxetane resins. When two or more types of oxetane resins are contained, the total amount thereof preferably falls within the above range.


The resin composition of the present embodiment may also contain substantially no oxetane resin. The phrase “contain substantially no” means that the content of the oxetane resin is less than 0.1 parts by mass relative to 100 parts by mass of the resin solid content in the resin composition.


Benzoxazine Compound

The resin composition of the present embodiment may contain a benzoxazine compound.


The benzoxazine compound is not particularly limited as long as it is a compound having two or more (preferably from 2 to 12, more preferably from 2 to 6, even more preferably from 2 to 4, still more preferably 2 or 3, and yet more preferably 2) dihydrobenzoxazine rings per molecule, and can be selected from a wide variety of compounds commonly used in the field of printed wiring boards.


Examples of the benzoxazine compound include a bisphenol A-type benzoxazine BA-BXZ (available from Konishi Chemical Ind. Co., Ltd.), a bisphenol F-type benzoxazine BF—BXZ (available from Konishi Chemical Industry Co., Ltd.), and a bisphenol S-type benzoxazine BS—BXZ (available from Konishi Chemical Industry Co., Ltd.).


The resin composition of the present embodiment preferably contains the benzoxazine compound to such an extent that the effects of the present invention are not impaired. When the resin composition of the present embodiment contains the benzoxazine compound, the content of the benzoxazine compound is preferably 0.1 parts by mass or more and preferably 50 parts by mass or less relative to 100 parts by mass of the resin solid content in the resin composition.


The resin composition of the present embodiment may contain only one benzoxazine compound or may contain two or more benzoxazine compounds. When two or more types of benzoxazine compounds are contained, the total amount thereof preferably falls within the above range.


The resin composition of the present embodiment may also contain substantially no benzoxazine compound. The phrase “contain substantially no” means that the content of the benzoxazine compound is less than 0.1 parts by mass relative to 100 parts by mass of the resin solid content in the resin composition.


Arylcyclobutene Resin

The resin composition of the present embodiment may contain an arylcyclobutene resin.


For details thereof, the arylcyclobutene resins described in paragraph [0042] of JP 2019-194312 A are exemplified, the content of which is incorporated herein by reference.


Polyamide Resin

The resin composition of the present embodiment may contain a polyamide resin or a thermosetting polyamide resin.


For details thereof, reference can be made to the polyamide described in paragraph [0065] of JP 2019-194312 A, and the polyamide described in paragraph [0063] of JP 6951829 B, the contents of which are incorporated herein by reference.


Polyimide Resin

The resin composition of the present embodiment may contain a polyimide resin or a thermosetting polyimide resin.


For details thereof, reference can be made to the polyimide described in paragraphs [0063] to [0064] of JP 6951829 B, the content of which is incorporated herein by reference.


Perfluorovinyl Ether Resin

The resin composition of the present embodiment may contain a perfluorovinyl ether resin or a perfluorovinyl benzyl ether resin.


For details thereof, the perfluorovinyl ether resins described in paragraph [0043] of JP 2019-194312 A are exemplified, the content of which is incorporated herein by reference.


Polyphenylene Ether Compound Having Unsaturated Carbon-Carbon Double Bond at Terminal and Compound Having Styrene Group Other than Styrene Resin Represented by Formula (T-St)


The resin composition of the present embodiment may contain the polyphenylene ether compound having an unsaturated carbon-carbon double bond at a terminal and a compound having a styrene group other than the styrene resin represented by Formula (T-St).


For details thereof, the compound having styrene at a terminal described in WO 2022/210095 (for example, compounds described in Synthesis Examples 12 to 16 of the same publication), the description in paragraphs [0029] to [0038] of JP 2022-85610 A, and the vinyl benzyl ether resin described in paragraph [0041] of JP 2019-194312 A are exemplified, the contents of which are incorporated herein by reference.


Compound Having Isopropenyl Group Other than Resin Represented by Formula (T)


The resin composition of the present embodiment may contain a compound having an isopropenyl group other than the resin represented by Formula (T).


For details thereof, the resin having an isopropenyl group described in WO 2022/210095 (for example, compounds described in Synthesis Examples 1, 2, 7, and 8 of the same publication) are exemplified, the content of which is incorporated herein by reference.


Polyfunctional (Meth)Acrylate Compound Other than Polyphenylene Ether Compound Having Unsaturated Carbon-Carbon Double Bond at Terminal


The resin composition of the present embodiment may contain a polyfunctional (meth)acrylate compound other than the polyphenylene ether compound having an unsaturated carbon-carbon double bond at a terminal. Here, the polyfunctional (meth)acrylate compound means a compound containing two or more (meth)acryloyloxy groups in one molecule, and preferably contains three or more (meth)acryloyloxy groups in one molecule.


The polyfunctional (meth)acrylate compound is preferably a compound having three to five (meth)acryloyloxy groups, more preferably a compound having three or four (meth)acryloyloxy groups, and still more preferably a compound having three (meth)acryloyloxy groups. The (meth)acrylate compound is preferably a compound having a methacryloyloxy group.


Since the polyfunctional (meth)acrylate compound has a large number of (meth)acrylate groups as crosslinking points, the polyfunctional (meth)acrylate compound is firmly cured together with an additional resin component, so that a cured product having excellent low dielectric properties (Dk and/or Df) and thermal resistance is produced. The polyfunctional (meth)acrylate compound is preferably a compound represented by Formula (MA).




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(In Formula (MA), R1 represents a hydrogen atom or a substituent, and R2 each independently represents a hydrogen atom or a methyl group.)


In Formula (MA), R1 represents a hydrogen atom or a substituent, and is more preferably a substituent having a formula weight of 15 to 500, more preferably a substituent having a formula weight of 15 to 300, still more preferably a substituent having a formula weight of 15 to 100, and even more preferably a substituent having a formula weight of 15 to 50.


R1 is preferably a hydrocarbon group or a (meth)acryloyloxy group, more preferably a hydrocarbon group having 22 or less carbons, and still more preferably an alkyl group having from 1 to 22 carbons or an alkenyl group having from 2 to 22 carbons. The use of a compound having an alkyl group having from 1 to 22 carbons or an alkenyl group having from 2 to 22 carbons can provide a resin composition capable of producing a cured product having excellent crosslinkability and high toughness. Thus, even when a substrate such as glass cloth is not contained in the resin composition, it is possible to suppress cracking during etching treatment.


The number of carbons in the alkyl group and/or the alkenyl group is preferably 2 or more, may be 8 or more, and may be 12 or more or 18 or less from the viewpoint of improving handleability. It is considered that the resin flowability of the resin composition is accordingly improved, and circuit filling properties are more excellent when a multilayer circuit board or the like is produced using the resin composition of the present embodiment.


In the present embodiment, the (meth)acrylic group equivalent of the compound represented by Formula (MA) is preferably 1000 g/eq. or less. When the equivalent is 1000 g/eq. or less, a high Tg tends to be achieved more reliably. The lower limit of the (meth)acrylic group equivalent is, for example, 99 g/eq. or more.


The alkyl group having from 1 to 22 carbons is preferably a linear alkyl group having from 1 to 22 carbons or a branched alkyl group having from 3 to 22 carbons, and examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, an eicosyl group, and a docosyl group. The alkenyl group having from 2 to 22 carbons is preferably an alkenyl group having 2 to 15 carbons, and examples thereof include an allyl group and a decenyl group.


Specific examples of the compound represented by Formula (MA) include trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, and pentaerythritol tetra(meth)acrylate. These may be used singly or in combination of two or more types thereof, or may be used as a prepolymer.


The compound represented by Formula (MA) to be used may be a commercially available product. The commercially available product is not particularly limited, and examples of trimethylolpropane trimethacrylate include “NK Ester TMPT” available from Shin-Nakamura Chemical Co., Ltd.


The molecular weight of the polyfunctional (meth)acrylate compound is preferably 300 or more, more preferably 330 or more, and may be 400 or more or 500 or more. When the molecular weight is equal to or higher than the above lower limit, the low dielectric properties (Dk and/or Df) and the thermal resistance of the resulting cured product tend to be further improved. The molecular weight of the (meth)acrylate compound (preferably, the compound represented by Formula (MA)) is preferably 3000 or less, more preferably 2000 or less, still more preferably 1000 or less, and even more preferably 800 or less. When the molecular weight is equal to or lower than the above upper limit, the low thermal expansion of the resulting cured product tends to be further improved.


For details thereof, the resin having a (meth)acrylic group described in WO 2022/210095 (for example, compounds described in Synthesis Examples 5 and 21 of the same publication) and the resin having a (meth)acrylic group described in JP 6962507 B (for example, compounds described in Examples 1 to 9) are exemplified, the contents of which are incorporated herein by reference.


When the resin composition of the present embodiment contains a polyfunctional (meth)acrylate compound, the content of the compound is preferably 1 part by mass or more, more preferably 3 parts by mass or more, still more preferably 5 parts by mass or more, and may be 10 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the polyfunctional (meth)acrylate compound is equal to or higher than the above lower limit, the resin composition tends to have excellent moldability, and the thermal resistance and low thermal expansion of the resulting cured product tend to be further improved. The upper limit of the content of the (meth)acrylate compound is preferably 40 parts by mass or less, and more preferably 30 parts by mass or less, and may be 20 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the content of the polyfunctional (meth)acrylate compound is equal to or lower than the above upper limit, the thermal resistance and low dielectric properties (Dk and/or Df) of the resulting cured product tend to be further improved.


The resin composition of the present embodiment may contain only one polyfunctional (meth)acrylate compound, or may contain two or more polyfunctional (meth)acrylate compounds. When two or more types of polyfunctional (meth)acrylate compounds are contained, the total amount thereof preferably falls within the above range.


Elastomer

The resin composition of the present embodiment may contain an elastomer. The elastomer may be thermoplastic, thermosetting, or neither thermoplastic nor thermosetting, and is preferably thermoplastic.


The elastomer in the present embodiment is not particularly limited, and examples of the elastomer include at least one selected from the group consisting of polyisoprene, polybutadiene, styrene-butadiene, butyl rubber, ethylene-propylene rubber, styrene-butadiene-ethylene, styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-ethylene-butylene-styrene, styrene-propylene-styrene, styrene-ethylene-propylene-styrene, fluororubber, silicone rubber, their hydrogenated compounds, their alkylated compounds, and their copolymers.


Other examples of the elastomer include oligomers or polymers having a curable vinyl functional group and polybutadiene resins described in paragraphs [0044] and [0045] of JP 2019-194312 A, the content of which is incorporated herein by reference.


The number average molecular weight of the elastomer (preferably, thermoplastic elastomer) used in the present embodiment is preferably 1000 or more. When the number average molecular weight is 1000 or more, the resulting cured product tends to have more excellent low dielectric properties (Dk and/or Df, in particular, low dielectric loss tangent). The number average molecular weight is preferably 1500 or more, more preferably 2000 or more, and may be 600000 or more, 700000 or more, or 800000 or more depending on the intended use. The upper limit of the number average molecular weight of the elastomer is preferably 400000 or less, more preferably 350000 or less, and still more preferably 300000 or less. When the number average molecular weight is equal to or lower than the above upper limit, the solubility of the elastomer component in the resin composition tends to be improved.


In a case where the resin composition of the present embodiment contains two or more elastomers, the number average molecular weight of a mixture thereof preferably satisfies the range described above.


Examples of the elastomer used in the present embodiment include a resin containing a polybutadiene structure. The polybutadiene structure may be partially or fully hydrogenated. Specific examples thereof include B-1000, B-2000, B-3000, BI-2000, and BI-3000 available from Nippon Soda Co., Ltd., and Ricon 100, Ricon 130, Ricon 131, Ricon 142, Ricon 150, Ricon 181, and Ricon 184 available from CRAY VALLEY.


Examples of the elastomer used in the present embodiment include a resin containing a poly(meth)acrylate structure. Specific examples thereof include Teisan Resin available from Nagase ChemteX Corporation, and ME-2000, W-197C, KG-15, and KG-3000 available from Negami Chemical Industrial Co., Ltd.


Examples of the elastomer used in the present embodiment include a resin containing a polycarbonate structure. The resin containing a polycarbonate structure may be referred to as a “polycarbonate resin”. Examples of such a resin include a carbonate resin having no reactive group, a hydroxy group-containing carbonate resin, a phenolic hydroxyl group-containing carbonate resin, a carboxy group-containing carbonate resin, an acid anhydride group-containing carbonate resin, an isocyanate group-containing carbonate resin, a urethane group-containing carbonate resin, and an epoxy group-containing carbonate resin. Here, the reactive group refers to a functional group capable of reacting with other components such as a hydroxy group, a phenolic hydroxyl group, a carboxy group, an acid anhydride group, an isocyanate group, a urethane group, and an epoxy group.


Specific examples of the polycarbonate resin include FPC 0220 and FPC 2136 available from MITSUBISHI GAS CHEMICAL COMPANY, INC., and T6002 and T6001 (polycarbonate diol) available from Asahi Kasei Chemicals Corporation.


Examples of the elastomer used in the present embodiment include a resin containing a polysiloxane structure. Specific examples thereof include SMP-2006, SMP-2003 PGMEA, SMP-5005 PGMEA, KR-510, and SMP-7014-3S available from Shin-Etsu Chemical Co., Ltd.


Examples of the elastomer used in the present embodiment include a resin containing a polyalkylene structure and/or a polyalkyleneoxy structure. The polyalkyleneoxy structure is preferably a polyalkyleneoxy structure having from 2 to 15 carbons, more preferably a polyalkyleneoxy structure having from 3 to 10 carbons, and particularly preferably a polyalkyleneoxy structure having from 5 to 6 carbons. Specific examples of the resin containing a polyalkylene structure and/or a polyalkyleneoxy structure include PTXG-1000 and PTXG-1800 available from Asahi Kasei Fibers Corporation.


Examples of the elastomer used in the present embodiment include a resin containing a polyisoprene structure. Specific examples thereof include KL-610 and KL613 available from Kuraray Co., Ltd.


Examples of the elastomer used in the present embodiment include a resin containing a polyisobutylene structure. Specific examples thereof include SIBSTAR-073T (styrene-isobutylene-styrene triblock copolymer) and SIBSTAR-042D (styrene-isobutylene diblock copolymer) available from KANEKA CORPORATION.


In the present embodiment, the elastomer is preferably an elastomer containing a styrene monomer unit and a conjugated diene monomer unit (hereinafter referred to as “elastomer (e)”). By using such an elastomer (e), the resulting cured product has more excellent low dielectric properties (Dk and/or Df, in particular, low dielectric loss tangent).


The elastomer (e) contains a styrene monomer unit. When the elastomer (e) contains the styrene monomer unit, the solubility of the elastomer (e) in the resin composition is improved. Examples of the styrene monomer include styrene, α-methylstyrene, p-methylstyrene, divinylbenzene (vinylstyrene), N,N-dimethyl-p-aminoethylstyrene, and N,N-diethyl-p-aminoethylstyrene. Of these, styrene, α-methylstyrene, and p-methylstyrene are preferred from the viewpoint of availability and productivity. Of these, styrene is particularly preferred.


The content of the styrene monomer unit in the elastomer (e) is preferably in a range of from 10 to 50 mass %, more preferably in a range of from 13 to 45 mass %, and still more preferably in a range of from 15 to 40 mass % of all the monomer units. When the content of the styrene monomer unit is 50 mass % or less, adhesion and pressure sensitive adhesion to a substrate or the like are further improved. In addition, the content of 10 mass % or more is preferred because there is a tendency that it is possible to suppress an increase in pressure sensitive adhesion, an adhesive residue or a stop mark is less likely to occur, and easy peelability between pressure sensitive adhesive surfaces is improved.


The elastomer (e) may contain only one styrene monomer unit, or two or more styrene monomer units. When two or more styrene monomer units are contained, the total amount thereof preferably falls within the above range.


As for a method for measuring the content of the styrene monomer unit in the elastomer (e) of the present embodiment, reference can be made to WO 2017/126469, the content of which is incorporated herein by reference. The same shall apply to the conjugated diene monomer unit described below.


The elastomer (e) contains a conjugated diene monomer unit. When the elastomer (e) contains the conjugated diene monomer unit, the solubility of the elastomer (e) in the resin composition is improved. The conjugated diene monomer is not particularly limited as long as it is a diolefin having a pair of conjugated double bonds. Examples of the conjugated diene monomer include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, and farnesene. Of these, 1,3-butadiene and isoprene are preferred, and 1,3-butadiene is more preferred.


The elastomer (e) may contain only one conjugated diene monomer unit, or two or more conjugated diene monomer units.


In the elastomer (e), the mass ratio of the styrene monomer unit to the conjugated diene monomer unit (styrene monomer unit/conjugated diene monomer unit) is preferably in a range of from 5/95 to 80/20, more preferably in a range of from 7/93 to 77/23, and still more preferably in a range of from 10/90 to 70/30. When the mass ratio of the styrene polymer unit to the conjugated diene monomer unit is in a range of from 5/95 to 80/20, it is possible to suppress an increase in pressure sensitive adhesion and to maintain the pressure sensitive adhesive strength at a high level, and easy peelability between pressure sensitive adhesive surfaces is improved.


In the elastomer (e), all of the conjugated diene bonds of the elastomer may be hydrogenated, some of the conjugated diene bonds may be hydrogenated, or the conjugated diene bonds may not be hydrogenated.


The elastomer (e) may or may not contain an additional monomer unit in addition to the styrene monomer unit and the conjugated diene monomer unit. Examples of the additional monomer unit include an aromatic vinyl compound unit other than the styrene monomer unit.


In the elastomer (e), the total of the styrene monomer unit and the conjugated diene monomer unit is preferably 90 mass % or more, more preferably 95 mass % or more, still more preferably 97 mass % or more, and even more preferably 99 mass % or more of all the monomer units.


As described above, the elastomer (e) may contain only one type of each of the styrene monomer unit and the conjugated diene monomer unit, or may contain two or more types of each of the styrene monomer unit and the conjugated diene monomer unit. When two or more types of each of the monomer units are contained, the total amount thereof preferably falls within the above range.


The elastomer (e) used in the present embodiment may be a block polymer or a random polymer. The elastomer (e) may be a hydrogenated elastomer in which the conjugated diene monomer units are hydrogenated, an unhydrogenated elastomer in which the conjugated diene monomer units are not hydrogenated, or a partially hydrogenated elastomer in which the conjugated diene monomer units are partially hydrogenated, and is preferably an unhydrogenated elastomer or a partially hydrogenated elastomer.


In one embodiment of the present embodiment, the elastomer (e) is a hydrogenated elastomer. Here, the hydrogenated elastomer means, for example, one in which double bonds based on a conjugated diene monomer unit in an elastomer is hydrogenated, and is intended to include one having a hydrogenation percentage (hydrogenation rate) of 80% or more in addition to one having a hydrogenation rate of 100%. The hydrogenation rate of the hydrogenated elastomer is preferably 85% or more, more preferably 90% or more, and even more preferably 95% or more. In the present embodiment, the hydrogenation rate is calculated from the measurement results of 1H-NMR spectrum measurement.


In one embodiment of the present embodiment, the elastomer (e) is an unhydrogenated elastomer. Here, the “unhydrogenated elastomer” is intended to include an elastomer in which the proportion of hydrogenated double bonds among double bonds based on a conjugated diene monomer unit; i.e., a hydrogenation percentage (hydrogenation rate) is 20% or less. The hydrogenation rate is preferably 15% or less, more preferably 10% or less, and still more preferably 5% or less.


Meanwhile, the partially hydrogenated elastomer means one in which some of double bonds based on a conjugated diene monomer unit in an elastomer are hydrogenated, and usually refers to one having a hydrogenation percentage (hydrogenation rate) of less than 80% and more than 20%.


Examples of commercially available products of the elastomer (e) used in the present embodiment include SEPTON (registered trademark) 2104, V9461, and S8104 available from Kuraray Co., Ltd., S.O.E. (registered trademark) S1606, S1613, S1609, and S1605 available from Asahi Kasei Corporation, TUFTEC (registered trademark) H1041, H1043, P2000, and MP10 available from Asahi Kasei Corporation, and DYNARON (registered trademark) 9901P and TR2250 available from JSR Corporation.


The elastomer used in the present embodiment may also be a liquid diene. The liquid diene means a liquid elastomer containing a conjugated diene monomer unit. Examples of the conjugated diene monomer include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, and farnesene. Of these, 1,3-butadiene and isoprene are preferred, and 1,3-butadiene is more preferred.


Examples of the liquid diene used in the present embodiment include liquid polybutadiene, liquid polyisoprene, a modified product of liquid polybutadiene, a modified product of liquid polyisoprene, a liquid acrylonitrile-butadiene copolymer, and a liquid styrene-butadiene copolymer.


The number average molecular weight of the liquid diene is not particularly limited as long as it is liquid at 20° C., and is preferably 500 or more and 10000 or less.


When the resin composition of the present embodiment contains the elastomer (preferably, the elastomer (e)), the content thereof is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and still more preferably 8 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition, and may be 10 parts by mass or more, or 12 parts by mass or more depending on the intended use. When the content is equal to or higher than the above lower limit, the dielectric properties (low dielectric loss tangent) tend to be further improved. The upper limit of the content of the elastomer is preferably 45 parts by mass or less, more preferably 40 parts by mass or less, still more preferably 35 parts by mass or less, even more preferably 32 parts by mass or less, and further more preferably 28 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the content is equal to or lower than the above upper limit, the heat resistance tends to be further improved.


The resin composition of the present embodiment may contain only one elastomer or may contain two or more elastomers. When two or more types of elastomers are contained, the total amount thereof preferably falls within the above range.


The resin composition in the present embodiment may also contain substantially no elastomer. The phrase “contain substantially no elastomer” means that the content of the elastomer is less than 1 part by mass relative to 100 parts by mass of the resin solid content in the resin composition, and the content is preferably less than 0.1 parts by mass, and more preferably less than 0.01 parts by mass.


Petroleum Resin

The resin composition of the present embodiment may contain a petroleum resin. The incorporation of the petroleum resin can reduce the melt viscosity.


The petroleum resin is a resin produced by thermally decomposing petroleum naphtha, collecting necessary fractions, and polymerizing the remaining fraction without isolating an unsaturated hydrocarbon in the absence of a catalyst or in the presence of a catalyst. The remaining fraction is mainly a fraction containing C5 fractions (e.g., isoprene, piperylene, cyclopentadiene, pentenes, and pentanes) or C9 fractions (e.g., vinyltoluene, indene, and dicyclopentadiene).


The catalyst used for the production of the petroleum resin is preferably an acidic catalyst. Specific examples of the usable catalyst include Lewis acids such as a boron trifluoride phenol complex, a boron trifluoride ether complex, aluminum chloride, aluminum bromide, iron (III) chloride, and iron (III) bromide, solid acids such as zeolite, silica, montmorillonite, and alumina, ion exchange resins such as a sulfonate group-containing fluororesin and a sulfonate group-containing polystyrene resin, and protic acids such as sulfuric acid, hydrochloric acid, acetic acid, phosphoric acid, oxalic acid, nitric acid, paratoluenesulfonic acid, and trifluoroacetic acid. Among them, a Lewis acid or a solid acid, which hardly causes a side reaction and achieves a high reaction rate, is preferably used, and any complex of boron trifluoride or aluminum chloride is more preferred from the viewpoint of availability and high reactivity.


The weight average molecular weight of the petroleum resin is not particularly limited, and is preferably 500 to 10000 and more preferably 500 to 5000. When the weight average molecular weight is equal to or lower than the above upper limit, the resin is easily compatible with other resins, and the solubility in a solvent tends to be increased. When the weight average molecular weight is equal to or higher than the above lower limit, the thermal resistance and mechanical strength of the resulting cured product tends to be further improved.


The softening point of the petroleum resin is not particularly limited, and is preferably high, preferably 80° C. or higher, and more preferably 100° C. or higher. When the softening point is equal to or higher than the above lower limit, the thermal resistance of the resulting cured product tends to be further improved.


Examples of the petroleum resin include aliphatic petroleum resins, aromatic petroleum resins, copolymer-based petroleum resins, and dicyclopentadiene-based petroleum resins, and dicyclopentadiene-based petroleum resins are preferred.


Examples of the dicyclopentadiene-based petroleum resin include resins produced by polymerizing a dicyclopentadiene-based fraction such as dicyclopentadiene, isopropenylnorbornene, dimethyldicyclopentadiene, or tricyclopentadiene, and resins produced by polymerizing a dicyclopentadiene-based fraction and an additional monomer having an unsaturated bond, preferably an unsaturated cyclic olefin.


Examples of the unsaturated cyclic olefin include cyclopentadiene; norbornene-based monomers such as 2-norbornene, 5-methyl-2-norbornene, 5-ethylidene-2-norbornene, 5-phenylnorbornene, 5-propenyl-2-norbornene, and 5-ethylidene-2-norbornene; and tri- or more-cyclic norbornene-based monomers, for example, tricyclic compounds other than dicyclopentadiene-based fractions, such as diethyldicyclopentadiene and dihydrodicyclopentadiene, tetracyclic compounds such as tetracyclododecene, pentacyclic compounds such as tricyclopentadiene, heptacyclic compounds such as tetracyclopentadiene, and alkyl-substituted, alkylidene-substituted, and aryl-substituted compounds of these polycyclic compounds. Examples of the alkyl-substituted compound of the polycyclic compound include methyl, ethyl, propyl, and butyl-substituted compounds, examples of the alkylidene-substituted compound of the polycyclic compound include ethylidene-substituted compounds, and examples of the aryl-substituted compound of the polycyclic compound include phenyl, tolyl, and naphthyl-substituted compounds.


In addition, as an additional monomer having an unsaturated bond other than the unsaturated cyclic olefin, an olefin having from 3 to 12 carbons may be copolymerized, and examples of such an olefin include α-olefins such as propylene, butene-1, pentene-1, 1,3-pentadiene, hexene-1, heptene-1, octene-1, diisobutylene, nonene-1, decene-1, 4-phenylbutene-1, 6-phenylhexene-1, 3-methylbutene-1, 4-methylpentene-1, 3-methylpentene-1, 3-methylhexene-1, 4-methylhexene-1, 5-methylhexene-1, 3,3-dimethylpentene-1, 3,4-dimethylpentene-1, 4,4-dimethylpentene-1, vinylcyclohexane, and vinylcyclohexene; and halogen-substituted α-olefins such as hexafluoropropene, 2-fluoropropene, 3-fluoropropene, and 3,4-dichlorobutene-1.


Examples of additional monomers having an unsaturated bond other than the above-described monomers include ethylene, tetrafluoroethylene, fluoroethylene, 1,1-difluoroethylene, and trifluoroethylene; alkylstyrenes such as styrene, p-methylstyrene, o-methylstyrene, m-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, 3,4-dimethylstyrene, 3,5-dimethylstyrene, and p-t-butylstyrene; halogenated styrenes such as p-chlorostyrene, m-chlorostyrene, o-chlorostyrene, p-bromostyrene, m-bromostyrene, o-bromostyrene, p-fluorostyrene, m-fluorostyrene, o-fluorostyrene, and o-methyl-p-fluorostyrene; maleic anhydride, maleic acid, fumaric acid, allyl alcohol, 3-butene-2-ol, methylbutene-1-ol, vinyl acetate, and vinyl chloride.


The aforementioned monomers may be used singly, or two or more types may be used in combination.


Commercially available petroleum resins can be appropriately used. Examples of the aliphatic petroleum resin include Quintone A100, Quintone B170, Quintone K100, Quintone M100, Quintone R100, and Quintone C200S available from Zeon Corporation, and Marukarez T-100AS and Marukarez R-100AS available from Maruzen Petrochemical Co., Ltd., examples of the aromatic petroleum resin include Neopolymer L-90, Neopolymer 120, Neopolymer 130, Neopolymer 140, Neopolymer 150, Neopolymer 170S, Neopolymer 160, Neopolymer E-100, Neopolymer E-130, Neopolymer 130S, and Neopolymer S available from JXTG Nippon Oil & Energy Corporation, and Petcol LX, Petcol LX-HS, Petcol 100T, Petcol 120, Petcol 120HS, Petcol 130, Petcol 140, Petcol 140HM, Petcol 140HM5, Petcol 150, Petcol 150AS available from Tosoh Corporation, examples of the copolymer-based petroleum resins include Quintone D100, Quintone N180, Quintone P195N, Quintone S100, Quintone S195, Quintone U185, Quintone G100B, Quintone G115, Quintone D200, Quintone E200SN, and Quintone N295 available from Zeon Corporation, Petrotac 60, Petrotac 70, Petrotac 90, Petrotac 90V, Petrotac 100, Petrotac 100V, and Petrotac 90HM available from Tosoh Corporation, and examples of DCPD (dicyclopentadiene)-based petroleum resins Marukarez M-890A and Marukarez M-845A available from Maruzen Petrochemical Co., Ltd., Quintone 1325, Quintone 1345, Quintone 1500, Quintone 1525L, and Quintone 1700 available from Zeon Corporation, and HA085, HA103, HA105, HA125, HB103, and HB125 available from ENEOS Corporation.


The petroleum resin to be employed may be those described in Organic Synthetic Chemistry, Vol. 25, No. 6 (1967).


When the resin composition of the present embodiment contains a petroleum resin, the lower limit of the content thereof is preferably 1 part by mass or more, more preferably 5 parts by mass or more, still more preferably 10 parts by mass or more, even more preferably 20 parts by mass or more, and further more preferably 25 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. When the content is equal to or higher than the lower limit, the melt viscosity tends to be decreased. The upper limit of the content of the petroleum resin is preferably 70 parts by mass or less, more preferably 50 parts by mass or less, and may be 40 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the content is equal to or lower than the upper limit, Df tends to be decreased.


The resin composition of the present embodiment may contain only one type of petroleum resin, or may contain two or more types thereof. When two or more types of petroleum resins are contained, the total amount thereof preferably falls within the above range.


The resin composition of the present embodiment may also contain substantially no petroleum resin. The phrase “contain substantially no petroleum resin” means that the content of the petroleum resin is less than 1 part by mass relative to 100 parts by mass of the resin solid content in the resin composition, and the content is preferably less than 0.1 parts by mass, and more preferably less than 0.01 parts by mass.


Filler (D)

The resin composition of the present embodiment preferably contains a filler (D). The incorporation of the filler (D) can further improve the physical properties of the resin composition or a cured product thereof, such as low dielectric properties (Dk and/or Df), flame resistance, and low thermal expansion.


The filler (D) used in the present embodiment more preferably has excellent low dielectric properties (Dk and/or Df). For example, the filler (D) used in the present embodiment has a relative dielectric constant (Dk) at a frequency of 10 GHz as measured according to a cavity resonator perturbation method of preferably 8.0 or less, more preferably 6.0 or less, and still more preferably 4.0 or less. Furthermore, the lower limit of the relative dielectric constant is, for example, practically 2.0 or more. The filler (D) used in the present embodiment has a dielectric loss tangent (Df) at a frequency of 10 GHz as measured according to a cavity resonator perturbation method of preferably 0.05 or less, and more preferably 0.01 or less. The lower limit of the dielectric loss tangent is, for example, practically 0.0001 or more.


The type of the filler (D) used in the present embodiment is not particularly limited, and any filler commonly used in the art can be suitably used. Specific examples of the filler include silicas such as natural silica, fused silica, synthetic silica, amorphous silica, aerosil, and hollow silica; metal oxides such as alumina, white carbon, titanium white, titanium oxide, zinc oxide, magnesium oxide, and zirconium oxide; composite oxides such as zinc borate, zinc stannate, forsterite, barium titanate, strontium titanate, and calcium titanate; nitrides such as boron nitride, aggregated boron nitride, silicon nitride, and aluminum nitride; metal hydroxides such as aluminum hydroxide, aluminum hydroxide heat treated products (aluminum hydroxide subjected to heat treatment to reduce a part of crystal water), boehmite, and magnesium hydroxide (including hydrates); molybdenum compounds such as molybdenum oxide and zinc molybdate; inorganic fillers such as barium sulfate, clay, kaolin, talc, fired clay, fired kaolin, fired talc, mica, E-glass, A-glass, NE-glass, NER-glass, C-glass, L-glass, D-glass, S-glass, M-glass G20, short glass fibers (including fine powders of glass such as E glass, T glass, D glass, S glass, and Q glass), hollow glass, and spherical glass; and organic fillers such as styrene type, butadiene type, and acrylic type rubber powders, core-shell type rubber powders, silicone resin powders, silicone rubber powders, and silicone composite powders.


In the present embodiment, an inorganic filler is preferred, and more preferably the filler contains one or more selected from the group consisting of silica, aluminum hydroxide, aluminum nitride, boron nitride, forsterite, titanium oxide, barium titanate, strontium titanate, and calcium titanate. From the viewpoint of the low dielectric properties (Dk and/or Df), the filler more preferably contains one or more selected from the group consisting of silica and aluminum hydroxide, and even more preferably contains silica. The use of such an inorganic filler further improves the properties of the cured product of the resin composition, such as thermal resistance, low dielectric properties (Dk and/or Df), thermal expansion characteristics, dimensional stability, and flame resistance.


The content of the filler (D) in the resin composition of the present embodiment can be appropriately determined depending on the desired properties, and is not particularly limited. The content is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 40 parts by mass or more, yet even more preferably 60 parts by mass or more, and yet even more preferably 80 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. When the content is equal to or higher than the above lower limit, the thermal resistance, the low thermal expansion, and the dielectric loss tangent of the resulting cured product tend to be further improved. The upper limit of the content of the filler (D) is preferably 1000 parts by mass or less, more preferably 500 parts by mass or less, still more preferably 300 parts by mass or less, and even more preferably 250 parts by mass or less, and may be 200 parts by mass or less or 120 parts by mass or less, relative to 100 parts by mass of the resin solid content. When the content is equal to or lower than the above upper limit, the moldability of the resin composition tends to be further improved.


In one preferred embodiment of the resin composition of the present embodiment, the content of the filler (D) is from 30 mass % to 90 mass % of components excluding a solvent.


The resin composition of the present embodiment may contain only one type of filler (D) or may contain two or more types of fillers (D). When two or more types of fillers are contained, the total amount thereof preferably falls within the above range.


When the filler (D), in particular, an inorganic filler, is used in the resin composition of the present embodiment, a silane coupling agent may be further contained. The resin composition containing a silane coupling agent tends to further improve dispersibility of the filler (D) and adhesive strength between the resin components, the filler (D), and a substrate described below.


Examples of the silane coupling agent include, but are not particularly limited to, a silane coupling agent that is ordinarily used for surface treatment of an inorganic material. Examples of the silane coupling agent include aminosilane-based compounds (e.g., γ-aminopropyltriethoxysilane and N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane), epoxysilane-based compounds (e.g., γ-glycidoxypropyltrimethoxysilane), vinylsilane-based compounds (e.g., vinyltrimethoxysilane), styrylsilane-based compounds, acrylic silane-based compounds (e.g., γ-acryloxypropyltrimethoxysilane), cationic silane-based compounds (e.g., N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride), and phenylsilane-based compounds. The silane coupling agents may be used singly or in combination of two or more types.


The content of the silane coupling agent is not particularly limited, but may be from 0.1 to 5.0 parts by mass relative to 100 parts by mass of resin solid content.


Monomer or Oligomer Having Ethylenically Unsaturated Group

In the resin composition of the present embodiment, a monomer or oligomer having an ethylenically unsaturated group may be used in combination in order to enhance the thermosetting property and the curability with an active energy ray (for example, photocurability with ultraviolet rays). The oligomer or monomer having an ethylenically unsaturated group used in the present embodiment is not particularly limited as long as it is an oligomer or monomer having one or more ethylenically unsaturated groups per molecule. Examples thereof include a monomer or oligomer having a vinyl group, an isopropenyl group, an allyl group, or a (meth)acryloyl group, and a monomer or oligomer having a vinyl group is preferred.


In the present specification, a compound corresponding to a monomer or oligomer having an ethylenically unsaturated group and also corresponding to the polyphenylene ether compound (B) is defined as the polyphenylene ether compound (B).


More specific examples of the monomer having an ethylenically unsaturated group include a compound (F1) (compound (F1)) having a molecular weight of less than 1000 and containing one organic group containing an ethylenically unsaturated bond in the molecule.


The ethylenically unsaturated bond forming the ethylenically unsaturated bond-containing organic group does not include one contained as a part of an aromatic ring. Meanwhile, the ethylenically unsaturated bond includes an ethylenically unsaturated bond contained as a part of a non-aromatic ring. Examples of the ethylenically unsaturated bond contained as a part of a non-aromatic ring include a cyclohexenyl group in the molecule. It is also intended to include an ethylenically unsaturated bond contained in a portion other than a terminal of a linear or branched organic group, that is, in a linear or branched chain.


The organic group containing an ethylenically unsaturated bond is more preferably one selected from the group consisting of a vinyl group, an isopropenyl group, an allyl group, an acryloyl group, and a methacryl group, and still more preferably a vinyl group.


In the present specification, a compound corresponding to a monomer or oligomer having an ethylenically unsaturated group and also corresponding to a silane coupling agent is referred to as a silane coupling agent.


Compound (F1) used in the present embodiment preferably contains only atoms selected from a carbon atom, a hydrogen atom, an oxygen atom, a nitrogen atom, and a silicon atom, more preferably contains only atoms selected from a carbon atom, a hydrogen atom, an oxygen atom, and a silicon atom, and still more preferably contains only atoms selected from a carbon atom, a hydrogen atom, an oxygen atom, and an oxygen atom.


Compound (F1) used in the present embodiment may have a polar group or may have no polar group. Compound (F1) used in the present embodiment preferably has no polar group. Examples of the polar group include an amino group, a carboxyl group, a hydroxy group, and a nitro group.


In the present embodiment, the molecular weight of compound (F1) is preferably 70 or more, more preferably 80 or more, and still more preferably 90 or more. When the molecular weight is equal to or higher than the above lower limit, volatilization of compound (F1) from the resin composition of the present embodiment or a cured product thereof tends to be suppressed. The upper limit of the molecular weight of compound (F1) is preferably 500 or less, more preferably 400 or less, still more preferably 300 or less, further preferably 200 or less, and may be 150 or less. When the molecular weight is equal to or lower than the above upper limit, the effect of enhancing the reactivity with an additional resin compound tends to be further improved.


When two or more types of compounds (F1) are contained in the resin composition of the present embodiment, it is preferable that the average of the molecular weights of the compounds (F1) falls within the above range, and it is more preferable that the molecular weight of each of the compounds falls within the above preferable range.


In the present embodiment, the boiling point of compound (F1) is preferably 110° C. or higher, more preferably 115° C. or higher, and still more preferably 120° C. or higher. When the boiling point is equal to or higher than the above lower limit, volatilization of the compound (F1) when the resin composition is thermally cured is suppressed, thereby allowing for the reaction between the additional curable compound (C) and the compound (F1). The boiling point of compound (F1) is preferably 300° C. or lower, more preferably 250° C. or lower, and still more preferably 200° C. or lower. When the boiling point is equal to or lower than the above upper limit, the compound is less likely to remain as a residual solvent in the cured product.


When two or more types of compounds (F1) are contained in the resin composition of the present embodiment, the average value of the boiling points may fall within the above range, and the boiling point of each of the compounds preferably falls within the above preferable range.


Examples of compound (F1) include (meth)acrylic acid ester compounds, aromatic vinyl compounds (preferably styrenic compounds), isopropenyl group-containing compounds, saturated fatty acid vinyl compounds, vinyl cyanide compounds, ethylenically unsaturated carboxylic acids, ethylenically unsaturated carboxylic acid anhydrides, ethylenically unsaturated dicarboxylic acid monoalkyl esters, ethylenically unsaturated carboxylic acid amides, unsaturated polyester compounds based on maleic anhydride, fumaric acid, itaconic acid, and citraconic acid; unsaturated epoxy (meth)acrylate compounds containing an acryloyl group or a methacryloyl group; unsaturated epoxy compounds containing a vinyl group or a (meth)allyl group, urethane (meth)acrylate compounds, polyether (meth)acrylate compounds, polyalcohol (meth)acrylate compounds, alkyd acrylate compounds, polyester acrylate compounds, spiroacetal acrylate compounds, diallyl phthalate compounds, diallyl tetrabromophthalate compounds, diethylene glycol bisallyl carbonate, and polyethylene polythiol. Preferred is at least one selected from the group consisting of a (meth)acrylic acid ester compound, an aromatic vinyl compound, and a saturated fatty acid vinyl compound, and more preferred is an aromatic vinyl compound.


Specific examples of compound (F1) include methylstyrene (for example, 4-methylstyrene), ethylvinylbenzene, diethyl 4-vinylbenzylphosphonate, 4-vinylbenzylglycidyl ether, and α-methylstyrene. As specific examples of the compound (F1), reference can be made to the descriptions in paragraphs [0046] and [0049] of JP 2019-194312 A, the contents of which are incorporated herein by reference.


The resin composition according to the present embodiment preferably contains a styrene oligomer (F2) in order to improve the low dielectric constant and the low dielectric loss tangent. The styrene oligomer (F2) according to the present embodiment is preferably formed by polymerizing at least one selected from the group consisting of styrene, the aforementioned styrene derivative, and vinyltoluene. The number average molecular weight of the styrene oligomer (F2) is preferably 178 or more and preferably 1600 or less. The styrene oligomer (F2) is preferably a compound having no branched structure in which the average number of aromatic rings is 2 to 14, the total amount of 2 to 14 aromatic rings is 50 mass % or more, and the boiling point is 300° C. or higher.


Examples of the styrene oligomer (F2) used in the present embodiment include a styrene polymer, a vinyltoluene polymer, an α-methylstyrene polymer, a vinyltoluene-α-methylstyrene polymer, and a styrene-α-styrene polymer. The styrene polymer to be used may be a commercially available product, and examples thereof include Piccolastic A5 (available from Eastman Chemical), Piccolastic A-75 (available from Eastman Chemical), Piccotex 75 (available from Eastman Chemical), FTR-8100 (available from Mitsui Chemicals, Inc.), and FTR-8120 (available from Mitsui Chemicals, Inc.). Examples of the vinyltoluene-α-methylstyrene polymer include Piccotex LC (available from Eastman Chemical). Examples of the α-methylstyrene polymer include Crystalex 3070 (available from Eastman Chemical), Crystalex 3085 (available from Eastman Chemical), Crystalex (3100), Crystalex 5140 (available from Eastman Chemical), FMR-0100 (available from Mitsui Chemicals, Inc.), and FMR-0150 (available from Mitsui Chemicals, Inc.). Examples of the styrene-α-styrene polymer include FTR-2120 (available from Mitsui Chemicals, Inc.). These styrene oligomers may be used alone, or two or more types may be used in combination.


In the resin composition of the present embodiment, an α-methylstyrene oligomer is preferably used because it is thermally cured in a favorable manner and is excellent in fine wiring embeddability, solder heat resistance, low relative dielectric constant, and low dielectric loss tangent.


The resin composition according to the present embodiment preferably also contains a divinyl compound (F3) as a monomer having an ethylenically unsaturated group in order to improve the low dielectric constant and the low dielectric loss tangent.


The divinyl compound is a low molecular weight compound having two vinyl groups. Since the number of vinyl groups is two, the crosslinking density is such a favorable level that the crosslinking density is not excessively increased, and thus, the free volume of molecules increases, so that the dielectric loss tangent (Df) of the resulting cured product can be reduced. In addition, since the divinyl compound (F3) is used as a substitute for the resin (A), the polyphenylene ether compound (B), and some of the additional resin component (D), it is considered that a reduction in content of a component having a polar group itself also contributes to the reduction of the dielectric loss tangent (Df). It is considered that since each of the two functional groups of the divinyl compound is a vinyl group, the reactivity with the resin (A) and the polyphenylene ether compound (B) is improved, and as a result, the thermal resistance tends to be easily improved.


Here, the divinyl compound (F3) refers to a compound having a molecular weight of less than 600. The molecular weight is preferably 300 or less, and more preferably less than 195. The lower limit of the molecular weight is practically 54. Examples of the divinyl compound (F3) include divinylbenzene, 1-ethynyl-4-[2-(4-ethynylphenyl)ethyl]benzene (BVPE), and 1,3-vinyltetramethylsiloxane.


As the monomer or oligomer having an ethylenically unsaturated group, 1,3-diisopropenylbenzene and 1,4-diisopropenylbenzene are also preferably used.


For other details of the monomer or oligomer having an ethylenically unsaturated group, a reference can be made to paragraphs [0069] to [0087] of WO 2017/135168 and paragraphs [0065] to [0067] of WO 2019/230945, the contents of which are incorporated herein by reference.


When the resin composition of the present embodiment contains a monomer or oligomer having an ethylenically unsaturated group, the content thereof is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, still more preferably 2 parts by mass or more, and even more preferably 3 parts by mass or more, and may be 5 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. When the content is equal to or higher than the above lower limit, the low dielectric properties (Dk and/or Df) of the resulting cured product tend to be further improved. The upper limit of the content of the monomer or oligomer having an ethylenically unsaturated group is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, still more preferably 20 parts by mass or less, even more preferably 15 parts by mass or less, and further more preferably 10 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the content is equal to or lower than the above upper limit, the thermal resistance of the resulting cured product tends to be further improved. In addition, the low dielectric constant, the low dielectric loss tangent, and the chemical resistance tend to be further improved.


The resin composition of the present embodiment may contain only one type of monomer or oligomer having an ethylenically unsaturated group or may contain two or more types thereof. When two or more types are contained, the total amount thereof preferably falls within the above range.


Flame Retardant

The resin composition of the present embodiment may contain a flame retardant. Examples of the flame retardant include a phosphorus-based flame retardant, a halogen-based flame retardant, an inorganic flame retardant, and a silicone-based flame retardant, and a phosphorus-based flame retardant is preferred.


For the flame retardant, known flame retardants can be used, and examples include halogen-based flame retardants, such as a brominated epoxy resin, brominated polycarbonate, brominated polystyrene, brominated styrene, brominated phthalimide, tetrabromobisphenol A, pentabromobenzyl (meth)acrylate, pentabromotoluene, tribromophenol, hexabromobenzene, decabromodiphenyl ether, bis-1,2-pentabromophenylethane, chlorinated polystyrene, and chlorinated paraffin; phosphorus-based flame retardants, such as red phosphorus, tricresyl phosphate, triphenyl phosphate, cresyl diphenyl phosphate, trixylenyl phosphate, trialkyl phosphate, dialkyl phosphate, tris(chloroethyl) phosphate, phosphazene, 1,3-phenylene bis(2,6-dixylenyl phosphate), and 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide; inorganic flame retardants, such as aluminum hydroxide, magnesium hydroxide, partial boehmite, boehmite, zinc borate, and antimony trioxide; and silicone-based flame retardants, such as a silicone rubber and a silicone resin.


In the present embodiment, among these, 1,3-phenylene bis(2,6-dixylenyl phosphate) is preferred, since the low dielectric properties (Dk and/or Df) of the resulting cured product are not impaired.


When the resin composition of the present embodiment contains a flame retardant, the content of the flame retardant is preferably 1 part by mass or more, and more preferably 5 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. The lower limit of the content of the flame retardant is preferably 30 parts by mass or less, and more preferably 25 parts by mass or less.


One flame retardant may be used alone, or two or more flame retardants may be used in combination. When two or more types are used, the total amount thereof falls within the above range.


Active Ester Compound

The resin composition of the present embodiment may contain an active ester compound. The active ester compound is not particularly limited, and for example, reference can be made to the descriptions in paragraphs [0064] to [0066] of WO 2021/172317, the content of which is incorporated herein by reference.


When the resin composition of the present embodiment contains an active ester compound, the content of the active ester compound is preferably 1 part by mass or more and preferably 90 parts by mass or less relative to 100 parts by mass of the resin solid content in the resin composition.


The resin composition of the present embodiment may contain only one type of active ester compound or may contain two or more types of active ester compounds. When two or more types of active ester compounds are contained, the total amount thereof preferably falls within the above range.


The resin composition of the present embodiment may contain substantially no active ester compound. The phrase “contain substantially no” means that the content of the active ester compound is less than 1 part by mass relative to 100 parts by mass of the resin solid content in the resin composition, and the content is preferably less than 0.1 parts by mass, and more preferably less than 0.01 parts by mass.


Dispersant

The resin composition of the present embodiment may contain a dispersant. A dispersant commonly used in paints can be suitably used, and the type of the dispersant is not particularly limited. The dispersant to be used is preferably a copolymer-based wet dispersant or a fluorine-containing fluorine-based dispersant.


Specific examples of the dispersant include DISPERBYK (registered trademark)-110, 111, 161, 180, 2009, 2152, 2155, BYK (registered trademark)-W996, W9010, W903, and W940 available from BYK Japan KK, Ftergent available from NEOS COMPANY LIMITED, and MPT available from MITSUBISHI PENCIL COMPANY, LIMITED.


When the resin composition of the present embodiment contains a dispersant, the lower limit of the content of the dispersant is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and may be 0.3 parts by mass or more relative to 100 parts by mass of the resin solid content in the resin composition. The upper limit of the content of the dispersant is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less relative to 100 parts by mass of the resin solid content in the resin composition.


One type of dispersant may be used alone, or two or more types of dispersants may be used in combination. When two or more types are used, the total amount falls within the above range.


Curing Accelerator

The resin composition of the present embodiment may further contain a curing accelerator. The curing accelerator is not particularly limited, and examples thereof include imidazoles such as 2-ethyl-4-methylimidazole and triphenylimidazole; organic peroxides such as benzoyl peroxide, bis(1-methyl-1-phenylethyl) peroxide), di-t-butyl peroxide, lauroyl peroxide, acetyl peroxide, parachlorobenzoyl peroxide, di-tert-butyl-di-perphthalate, α,α′-di(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, and 2,5-dimethyl-2,5-bis(t-butylperoxy)hexine-3; azo compounds such as azobisnitriles (for example, azobisisobutyronitrile); tertiary amines such as N,N-dimethylbenzylamine, N,N-dimethylaniline, N,N-dimethyltoluidine, 2-N-ethylanilinoethanol, tri-n-butylamine, pyridine, quinoline, N-methylmorpholine, triethanolamine, triethylenediamine, tetramethylbutanediamine, and N-methylpiperidine; phenols such as phenol, xylenol, cresol, resorcin, and catechol; high-temperature decomposition type radical generators such as 2,3-dimethyl-2,3-diphenylbutane; organometallic salts such as lead naphthenate, lead stearate, zinc naphthenate, zinc octylate, manganese octylate, tin oleate, dibutyltin malate, manganese naphthenate, cobalt naphthenate, and iron acetylacetone; products formed by dissolving these organometallic salts in hydroxyl group-containing compounds such as phenol and bisphenol; inorganic metal salts such as tin chloride, zinc chloride, and aluminum chloride; and organotin compounds such as dioctyltin oxide, other alkyltins, and alkyltin oxides.


The curing accelerator is preferably at least one selected from the group consisting of imidazoles, organic peroxides, and organometallic salts, and more preferably at least one selected from the group consisting of imidazoles and organometallic salts.


In the present embodiment, the resin composition may contain substantially no polymerization initiator such as an organic peroxide or an azo compound. The phrase “contain substantially no polymerization initiator” means that the content of the polymerization initiator is less than 0.1 parts by mass relative to 100 parts by mass of the resin solid content in the resin composition, and the content is preferably less than 0.01 parts by mass, and more preferably less than 0.001 parts by mass.


When the resin composition of the present embodiment contains a curing accelerator, the lower limit of the content of the curing accelerator is preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, and even more preferably 0.1 parts by mass or more relative to 100 parts by mass of the resin solid content in the resin composition. The upper limit of the content of the curing accelerator is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and still more preferably 2 parts by mass or less with respect to 100 parts by mass of the resin solid content in the resin composition.


One type of curing accelerator may be used alone, or two or more types of curing accelerators may be used in combination. When two or more types are used, the total amount thereof falls within the above range.


Solvent

The resin composition of the present embodiment may contain a solvent and preferably contains an organic solvent. When the resin composition of the present embodiment contains a solvent, the resin composition is in a (solution or varnish) form in which at least some, or preferably all of the respective resin solid contents described above are dissolved or homogeneously mixed in the solvent. The solvent is not particularly limited as long as it is any polar organic solvent or non-polar organic solvent capable of dissolving or homogeneously mixing at least some, or preferably all of the respective resin solid contents described above. Examples of the polar organic solvent include ketones (e.g., acetone, methyl ethyl ketone, and methyl isobutyl ketone), cellosolves (e.g., propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate), esters (e.g., ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, isoamyl acetate, ethyl lactate, methyl methoxypropionate, and methyl hydroxyisobutyrate), and amides (e.g., dimethoxyacetamide and dimethylformamide). Examples of the non-polar organic solvent include aromatic hydrocarbons (e.g., toluene and xylene).


One type of solvent may be used alone, or two or more types of solvents may be used in combination. When two or more types are used, the total amount thereof falls within the above range.


Additional Component

The resin composition of the present embodiment may contain various polymer compounds such as a thermoplastic resin and its oligomer, and various additives in addition to the components described above. Examples of the additive include ultraviolet absorbers, antioxidants, photopolymerization initiators, fluorescent whitening agents, photosensitizers, dyes, pigments, thickeners, flow control agents, lubricants, antifoaming agents, leveling agents, brighteners, and polymerization inhibitors. One of these additives may be used alone, or two or more types thereof may be used in combination.


The resin composition of the present embodiment may contain substantially no polymerization inhibitor. The phrase “contain substantially no polymerization inhibitor” means that the resin composition contains no polymerization inhibitor, or the content of the polymerization inhibitor in the resin composition is, for example, less than 0.008 parts by mass, and preferably 0.007 parts by mass or less, more preferably 0.001 parts by mass or less, and still more preferably 0.0001 parts by mass or less, relative to 100 parts by mass of the resin solid content.


Applications

The resin composition of the present embodiment is used as a cured product. Specifically, the resin composition of the present embodiment can be suitably used as a material having low dielectric properties (Dk and/or Df), or as a resin composition for an electronic material, such as an insulating layer of a printed wiring board or a material for a semiconductor package. The resin composition of the present embodiment can be suitably used as a material for a prepreg, a metal foil-clad laminate including the prepreg, a resin composite sheet, and a printed wiring board.


The resin composition of the present embodiment is used in the form of a layered material (intended to include a film-like or sheet-like material), such as a prepreg or a resin composite sheet serving as an insulating layer of a printed wiring board. When the resin composition is formed into such a layered material, the thickness of the layered material is preferably 5 μm or more and more preferably 10 μm or more. The upper limit of the thickness is preferably 200 μm or less and more preferably 180 μm or less. The thickness of the layered material means, for example, a thickness including that of a glass cloth when the glass cloth is impregnated with the resin composition of the present embodiment.


The material formed from the resin composition of the present embodiment may be used in an application to form a pattern by exposure and development or may be used in an application not involving exposure and development. In particular, the material is suitable for an application not involving exposure and development.


Prepreg

The prepreg of the present embodiment is formed from a substrate (prepreg substrate) and the resin composition of the present embodiment. The prepreg of the present embodiment is produced by, for example, applying the resin composition of the present embodiment to a substrate (e.g., impregnating and/or coating the substrate with the resin composition) and then semi-curing the resin composition by heating (e.g., by a method of drying at 120 to 220° C. for 2 to 15 minutes). In this case, the amount of the resin composition adhered to the substrate, that is, the amount of the resin composition (including the filler (D)) relative to the total amount of the prepreg after semi-curing is preferably in a range of 20 to 99 mass % and more preferably in a range of 20 to 80 mass %.


The substrate is not particularly limited as long as it is a substrate used in various printed wiring board materials. Examples of the material of the substrate include glass fibers (e.g., E-glass, D-glass, L-glass, S-glass, T-glass, Q-glass, UN-glass, NE-glass, NER-glass, and spherical glass), inorganic fibers other than glass (e.g., quartz), and organic fibers (e.g., polyimide, polyamide, polyester, liquid crystal polyester, and polytetrafluoroethylene). The form of the substrate is not particularly limited, and examples of the form include woven fabrics, nonwoven fabrics, rovings, chopped strand mats, and surfacing mats. One of these substrates may be used alone, or two or more types may be used in combination. Among these substrates, from the viewpoint of dimensional stability, the substrate is preferably a woven fabric subjected to ultra fiber opening or fine weaving; from the viewpoints of strength and low water absorbability, the substrate is preferably a glass woven fabric having a thickness of 200 μm or less and a mass of 250 g/m2 or less; and from the viewpoint of moisture absorption and thermal resistance, the substrate is preferably a glass woven fabric having a surface treated with a silane coupling agent such as an epoxysilane or an aminosilane. From the viewpoint of electrical properties, the substrate is more preferably a low dielectric glass cloth made of a glass fiber exhibiting low dielectric properties (Dk and/or Df), such as L-glass, NE-glass, NER-glass, or Q-glass.


The substrate of low relative dielectric constant is exemplified by a substrate having a relative dielectric constant of 5.0 or less (preferably from 3.0 to 4.9). The substrate of low dielectric loss tangent is exemplified by a substrate having a dielectric loss tangent of 0.006 or lower (preferably from 0.001 to 0.005). The relative dielectric constant and the dielectric loss tangent are values measured at a frequency of 10 GHz with a cavity resonator for perturbation.


Metal Foil-Clad Laminate

The metal foil-clad laminate of the present embodiment includes at least one layer formed from the prepreg of the present embodiment, and a metal foil disposed on one surface or both surfaces of the layer formed from the prepreg. Examples of the method for producing the metal foil-clad laminate of the present embodiment include a method of disposing at least one prepreg (preferably stacking two or more prepregs) of the present embodiment, disposing a metal foil on one surface or both surfaces of the prepreg, and laminate-molding the metal foil and the prepreg. More specifically, the metal foil-clad laminate can be produced by disposing a metal foil of copper, aluminum, or the like on one surface or both surfaces of the prepreg, and laminate-molding the metal foil and the prepreg. The number of prepregs is preferably from 1 to 10, more preferably from 2 to 10, and even more preferably from 2 to 9. The metal foil is not particularly limited as long as it is any metal foil used in materials for printed wiring boards, and examples of the metal foil include copper foils, such as a rolled copper foil and an electrolytic copper foil. The thickness of the metal foil (preferably a copper foil) is not particularly limited and may be approximately from 1.5 to 70 μm. When a copper foil is used as the metal foil, the surface roughness Rz of the copper foil as measured in accordance with JIS B0601:2013 is adjusted to from 0.2 to 4.0 μm. When the copper foil surface roughness Rz is 0.2 μm or more, the roughness of the copper foil surface is adjusted to a suitable level, and the copper foil peel strength tends to be further improved. Meanwhile, when the copper foil surface roughness Rz is 4.0 μm or less, the roughness of the copper foil surface becomes a suitable level, and conductor loss tends to be further reduced. The copper foil surface roughness Rz is more preferably 0.5 μm or more, still more preferably 0.6 μm or more, particularly preferably 0.7 μm or more from the viewpoint of improving the peel strength, and is more preferably 3.5 μm or less, still more preferably 3.0 μm or less, particularly preferably 2.0 μm or less from the viewpoint of reducing the conductor loss.


Examples of the laminate-molding method include methods commonly used in molding a laminate and a multilayer board for a printed wiring board, and more specific examples include a method of laminate-molding using a multi-stage press, a multi-stage vacuum press, a continuous molding machine, or an autoclave molding machine at a temperature of approximately 180 to 350° C., a heating time of approximately 100 to 300 minutes, and a surface pressure of approximately 20 to 100 kg/cm2. The prepreg of the present embodiment can be combined and laminate-molded with a separately produced wiring board for an inner layer, to thereby form a multilayer board. According to a multilayer board production method, a multilayer board can be produced by, for example, disposing copper foils of approximately 35 μm on both surfaces of one prepreg of the present embodiment, laminate-molding them by the molding method described above, then forming an inner layer circuit, subjecting the inner layer circuit to a blackening treatment to form an inner layer circuit board, then alternately disposing the inner layer circuit board and the prepreg of the present embodiment one by one, and further disposing a copper foil on the outermost layer, followed by lamination molding under the conditions described above, preferably under vacuum. The metal foil-clad laminate of the present embodiment can be suitably used as a printed wiring board.


As described above, the resin composition for electronic materials prepared using the resin composition of the present embodiment (resin composition containing a combination of specific components) has excellent moldability. The cured product of the resin composition can be provided with excellent low dielectric properties (Dk and/or Df, especially low dielectric loss tangent), low relative dielectric constant, crack resistance, appearance, low thermal expansion, and moisture absorption thermal resistance.


Printed Wiring Board

The printed wiring board of the present embodiment is a printed wiring board including an insulating layer and a conductor layer disposed on the surface of the insulating layer, and the insulating layer includes at least one of a layer formed from the resin composition of the present embodiment or a layer formed from the prepreg of the present embodiment. Such a printed wiring board can be produced by a common method, and the production method is not particularly limited. An example of the method of producing the printed wiring board is described below. Firstly, the above-described metal foil-clad laminate, such as a copper foil-clad laminate, is prepared. Next, the surface of the metal foil-clad laminate is subjected to an etching treatment to form an inner layer circuit, and an inner layer substrate is produced. The inner layer circuit surface of the inner layer substrate is subjected to surface treatment to increase the adhesive strength as necessary, then a required number of the prepregs described above are layered on the inner layer circuit surface, a metal foil for an outer layer circuit is further laminated on the outer side, and the laminate is heated, pressurized, and integrally molded. This process produces a multilayer laminate including an insulating layer composed of a substrate and a cured product of the resin composition formed between the inner layer circuit and the metal foil for the outer layer circuit. Subsequently, the multilayer laminate is subjected to hole formation for a through hole or a via hole, then a plated metal film for conduction between the inner layer circuit and the metal foil for the outer layer circuit is formed on the wall surface of the hole, and the metal foil for the outer layer circuit is subjected to an etching treatment to form the outer layer circuit, to thereby produce the printed wiring board.


The printed wiring board produced in the above-described production example is configured to have an insulating layer and a conductor layer formed on the surface of the insulating layer, and the insulating layer is configured to contain the resin composition of the present embodiment described above and/or its cured product. That is, the prepreg of the present embodiment described above (e.g., a prepreg formed from a substrate and the resin composition of the present embodiment impregnated into or applied onto the substrate) and the layer formed from the resin composition on the metal foil-clad laminate of the present embodiment described above serve as the insulating layer of the present embodiment.


The present embodiment also relates to a semiconductor device including the printed wiring board. As for details of the semiconductor device, reference can be made to paragraphs [0200] to [0202] of JP 2021-021027 A, the content of which is incorporated herein by reference.


In the insulating layer formed of the cured product of the resin composition of the present embodiment, it is preferable to reduce surface roughness of the insulating layer after roughening treatment. Specifically, the arithmetic average roughness Ra of the surface of the insulating layer after the roughening treatment is preferably 200 nm or less, more preferably 150 nm or less, and particularly preferably 100 nm or less. The lower limit of the arithmetic average roughness Ra is not particularly limited, and may be, for example, 10 nm or more. The arithmetic average roughness Ra of the surface of the insulating layer is measured using a non-contact type surface roughness meter, a VSI mode, and a lens with a magnification of 50.


WYKONT 3300 available from Veeco Instruments Inc is used as a non-contact type surface roughness meter.


Resin Composite Sheet

The resin composite sheet of the present embodiment includes a support and a layer formed from the resin composition of the present embodiment and disposed on a surface of the support. The resin composite sheet can be used as a build-up film or a dry film solder resist. The method of producing the resin composite sheet is not particularly limited, and examples include a method of producing the resin composite sheet by coating (painting) the support with a solution prepared by dissolving the resin composition of the present embodiment described above in a solvent, and then drying.


Examples of the support used herein include, but are not particularly limited to, organic-based film substrates, such as polyethylene films, polypropylene films, polycarbonate films, poly(ethylene terephthalate) films, ethylene-tetrafluoroethylene copolymer films, as well as release films formed by coating a surface of such a film with a release agent, and polyimide films; conductive foils, such as copper foils and aluminum foils; and plate-like supports, such as glass plates, steel use stainless (SUS) plates, and fiber-reinforced plastics (FRPs).


For example, the application method (coating method) involves application of a solution prepared by dissolving the resin composition of the present embodiment in a solvent onto a support by using a bar coater, a die coater, a doctor blade, or a Baker applicator. A single-layer sheet can also be formed by peeling or etching the support after drying from the resin composite sheet in which the support and the resin composition are laminated. A single-layer sheet can also be produced without using a support by, for example, feeding a solution prepared by dissolving the resin composition of the present embodiment described above in a solvent into a mold having a sheet-shaped cavity and drying the solution to mold into a sheet shape.


In the production of the single-layer sheet or the resin composite sheet of the present embodiment, the drying conditions for removing the solvent are not particularly limited. However, drying at a low temperature is likely to cause the solvent to remain in the resin composition, and drying at a high temperature allows the curing of the resin composition to proceed. Thus, the drying is preferably performed at a temperature of from 20° C. to 200° C. for 1 to 90 minutes. The single-layer sheet or resin composite sheet can be used in an uncured state where the solvent is only dried or can be used as necessary in a semi-cured (B-staged) state. Further, the thickness of the resin layer in the single-layer sheet or resin composite sheet of the present embodiment can be adjusted by controlling the concentration of the solution of the resin composition of the present embodiment used for coating (application) and the coating thickness, and is not particularly limited. However, in general, the solvent is likely to remain during drying in accordance with an increase in coating thickness. Thus, the thickness is preferably from 0.1 to 500 m.


EXAMPLES

The present invention will next be described in more detail with reference to Examples. Materials, amounts used, proportions, processing details, and processing procedures described in the following Examples can be appropriately changed without departing from the spirit of the present invention. Thus, the scope of the present invention is not limited to the specific examples described below.


When a measuring device used in the Examples is not readily available due to, for example, discontinuation, another device with equivalent performance can be used for measurement.


Measurement of Weight Average Molecular Weight and Number Average Molecular Weight

The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the resin (T), the hydroxy resin, and the styrene resin were measured by a gel permeation chromatography (GPC) method. The measurement was conducted using a liquid feed pump (LC-20AD available from Shimadzu Corporation), a differential refractive index detector (RID-20A available from Shimadzu Corporation), and GPC columns (GPC KF-801, 802, 803, 804, available from Showa Denko Corporation), and also using tetrahydrofuran as a solvent, a flow rate of 1.0 mL/min, a column temperature of 40° C., and a calibration curve based on monodispersed polystyrene.


Measurement of Parameters α and β

The parameters α and β in the resin represented by Formula (T) (resin (T)), the hydroxy resin, and the styrene resin were calculated by 1H-NMR measurement. The synthesized resin was dissolved in a mixed solvent of heptane and methanol and repeatedly dried to remove a residual solvent contained in a recovered solid. Thereafter, the recovered solid was dissolved in CDCl3 and subjected to 1H-NMR measurement. The parameters α and β of each resin were calculated using the following formula in the measured 1H-NMR.










Parameter


α

=


(


2.55

ppm



2.31

ppm


)






(


6.24

ppm



5.91

ppm


)

+


(


2.98

ppm



2.55

ppm


)

/







2
+

(


2.55

ppm



2.31

ppm


)










(
α
)













Parameter


β

=




[


(


5.49

ppm



4.89

ppm


)

-

(


4.89

ppm



4.45

ppm


)



}

×
1.5



(


2.31

ppm



1.96

ppm


)

-

(


2.55

ppm



2.31

ppm


)







(
β
)







(Each or the values in parentheses in Formulae (α) and (β) indicates an integral value PGP between the corresponding chemical shift values in 1H-NMR.)


Example 1
Synthesis of Resin (T-A)

A flask equipped with a thermometer and a cooling tube was charged with 520 g of toluene, 0.75 g of activated clay, 150 g of 1,3-diisopropenylbenzene (available from Tokyo Chemical Industry), and a stirring bar, and the mixture was heated to an internal temperature of 50° C. while being stirred. Thereafter, the mixture was gradually heated to an internal temperature of 70° C. over 6 hours, and further reacted at an internal temperature of 70° C. for 1.2 hours. After cooling, the activated clay was removed by filtration, and the solvent was distilled off with heating under reduced pressure to produce 125 g of a solid resin.


The produced resin represented by Formula (T) (resin (T-A)) had an Mw of 1336, an Mn of 713, and an Mw/Mn of 1.87. In Formula (Tx), the parameter α was 0.70, the parameter β was 0.92, and n+o+p was 3.5. In this case, n+o+p was calculated on the assumption that the structures in parentheses represented by (a), (b), and (c) in Formula (Tx) all have the same molecular weight, and the Mn of the synthesized resin is the average molecular weight (the same shall apply to the following Examples and Comparative Examples). It was confirmed that the amount of a residual monomer was 1 mass % or less by GPC analysis.


Mn and Mw were measured according to the above-described method. The number of repeating units was calculated from the value of Mn.


Synthesis of Hydroxy Resin (A)

A reactor equipped with a stirrer, a thermometer, and a cooling tube was charged with 100 g of the resin (T-A), 400 g of toluene, 100 g of 2,6-xylenol, and 10 g of activated clay, and the mixture was heated to an internal temperature of 70° C. while being stirred. The mixture was further reacted at an internal temperature of 70° C. for 5 hours. After cooling, the activated clay was removed by filtration, and washing was performed twice with 1M aqueous sodium hydroxide solution to remove remaining 2,6-xylenol. The washing was repeated with pure water until neutral pH was achieved, and then the solvent was distilled off with heating under reduced pressure to produce a solid resin.


The produced resin represented by Formula (T-OH) (hydroxy resin (A)) had an Mw of 1604, an Mn of 1090, and an Mw/Mn of 1.47. In Formula (Tx-OH), n+o+p was 4.3, and the OH equivalent was 571 g/eq.


Mn and Mw were measured according to the above-described method. The number of repeating units was calculated from the value of Mn.


The OH equivalent (hydroxyl group equivalent) of the hydroxy resin was measured in accordance with the following method (the same shall apply to the following Examples and Comparative Examples).


The hydroxyl group equivalent was determined by adding a 10 vol % solution of pyridine in acetic anhydride to the hydroxy resin, reacting the hydroxy resin with acetic anhydride in an oil bath at 100° C., subsequently adding water, reacting unreacted acetic anhydride with water, then titrating with sodium hydroxide to determine the amount of acetic acid in the system, and determining the amount of reaction between the acetic anhydride and the hydroxy resin obtained by calculation as the mass of the hydroxy resin per 1 mol of the hydroxyl group.


Synthesis of Styrene Resin (A)

A reactor equipped with a stirrer, a thermometer, and a reflux tube was charged with 100 g of the hydroxy resin (A) produced above, 400 g of toluene, 29.40 g (0.193 mol) of vinylbenzyl chloride (“CMS-14” available from AGC SEIMI CHEMICAL CO., LTD.), 22.58 g (0.07 mol) of tetrabutylammonium bromide (available from FUJIFILM Wako Pure Chemical Corporation), 66.0 g of pure water, and 84.1 g of 25 mass % aqueous NaOH solution, and the mixture was stirred at a reaction temperature of 70° C. After stirring for 5 hours, the organic layer was washed with 1M aqueous hydrochloric acid solution and then with pure water until the pH reached 7. The resultant solution was concentrated, and then added dropwise to methanol for solidification. Subsequently, a low molecular weight compound (compound having a molecular weight of 400 or less) containing a chlorine atom and/or a bromine atom was removed, and the solid was collected by filtration, followed by vacuum drying to produce a solid resin.


The produced resin represented by Formula (T-St) (styrene resin (A)) had an Mw of 1800, an Mn of 1320, and an Mw/Mn of 1.36. In Formula (Tx-St), n+o+p was 4.3, the OH equivalent was 25500 g/eq., and the sum of total Cl and total Br was 250 ppm by mass.


Mn and Mw were measured according to the above-described method. The number of repeating units was calculated from the value of Mn.


The total chlorine atom concentration (total Cl) and the total bromine atom concentration (total Br) of the styrene resin were measured using ion chromatography with a combustion apparatus (combustion and absorption unit device: AQF-2100H available from Mitsubishi Chemical Analytech Co., Ltd., ion chromatograph device: Dionex Integrion CT (available from Thermo Fisher SCIENTIFIC)) (the same shall apply to the following Examples and Comparative Examples).


In the present reaction system, no materials other than the specified materials are added (the same shall apply to the following Examples and Comparative Examples).


The OH equivalent (hydroxyl group equivalent) [g/eq.] of the styrene resin was measured in accordance with the following method (the same shall apply to the following Examples and Comparative Examples).


A styrene resin powder was weighed, and its mass was recorded. The powder was placed in a measuring flask, and then the volume was increased to a predetermined amount with dichloromethane to prepare a sample solution for measurement (measurement sample). The sample solution was placed in a measurement cell and set in an infrared spectrophotometer (FT/IR-4600, available from JASCO Corporation).


The sample solution was subjected to infrared spectroscopic measurement, and a peak area of a spectrum around 3600 cm−1 was recorded. The hydroxyl group concentration [mol/L] is determined as a measured value from the area and the calibration curve.


Subsequently, the hydroxyl group equivalent was calculated b the following formula.







Hydroxyl


group



equivalent

[

g
/

eq
.


]


=

powder



mass

[
g
]



in


measurement


sample
/
hydroxyl


group



concentration

[

mol
/
L

]

×
measurement


sample


solution



amount

[
L
]






Physical Properties
Production of Test Piece of Cured Plate Having Thickness of 1.0 mm

4.5 g of the produced styrene resin powder was spread in a stainless steel mold frame of 100 mm×30 mm×1.0 mm in height, set in a vacuum press machine (available from KITAGAWA SEIKI CO., LTD.), held at 200° C. for 1.5 hours, and pressed at a surface pressure of 1.9 MPa to produce a cured plate.


The produced cured plate was used for evaluation of glass transition temperature, relative dielectric constant (Dk), and dielectric loss tangent (Df). The evaluation results are shown in Table 1.


Methods of Measurement and Evaluation
(1) Glass Transition Temperature

A sample obtained by downsizing the cured plate to 12.7 mm×30 mm was subjected to measurement by a DMA (dynamic mechanical analysis) bending method in accordance with JIS C6481 5.17.2 using a dynamic viscoelasticity measuring device, and the determined peak temperature of loss modulus was defined as the glass transition temperature. The glass transition temperature was expressed in units of ° C.


DMA Q800 available from TA Instruments was used as the dynamic viscoelasticity measuring device.


(2) Relative Dielectric Constant (Dk) and Dielectric Loss Tangent (Df)

The cured plate was downsized to have a width of 1.0 mm and then dried at 120° C. for 60 minutes, and the relative dielectric constant (Dk) and the dielectric loss tangent (Df) at a frequency of 10 GHz after drying were measured using a cavity resonator for perturbation. The measurement temperature was 23° C.


The cavity resonator for perturbation was Agilent 8722ES available from Agilent Technologies.


Example 2
Synthesis of Resin (T-B)

A flask equipped with a thermometer and a cooling tube was charged with 520 g of toluene, 0.75 g of activated clay, 150 g of 1,3-diisopropenylbenzene (available from Tokyo Chemical Industry), and a stirring bar, and the mixture was heated to an internal temperature of 50° C. while being stirred. Thereafter, the mixture was gradually heated to an internal temperature of 70° C. over 5 hours, and further reacted at an internal temperature of 70° C. for 1 hour. After cooling, the activated clay was removed by filtration, and the solvent was distilled off with heating under reduced pressure to produce 129 g of a solid resin.


The produced resin represented by Formula (T) (resin (T-B)) had an Mw of 1193, an Mn of 693, and an Mw/Mn of 1.72. In Formula (Tx), the parameter α was 0.63, the parameter β was 1.07, and n+o+p was 3.4. It was confirmed that the amount of a residual monomer was 1 mass % or less by GPC analysis.


Mn and Mw were measured according to the above-described method. The number of repeating units was calculated from the value of Mn.


Synthesis of Hydroxy Resin (B)

A hydroxy resin (B) was produced in the same manner as in Synthesis of hydroxy resin (A) of Example 1 except that the resin (T-A) was changed to the resin (T-B) and the reaction temperature was changed to 110° C.


The produced resin represented by Formula (T-OH) (hydroxy resin (B)) had an Mw of 1730, an Mn of 1290, and an Mw/Mn of 1.34. In Formula (Tx-OH), the parameter α was 0.92, n+o+p was 5.6, and the OH equivalent was 671 g/eq.


Synthesis of Styrene Resin (B)

A reactor equipped with a stirrer, a thermometer, and a reflux tube was charged with 100 g of the hydroxy resin (B) produced above, 400 g of toluene, 25.02 g (0.164 mol) of vinylbenzyl chloride (“CMS-14” available from AGC SEIMI CHEMICAL CO., LTD.), 19.22 g (0.06 mol) of tetrabutylammonium bromide (available from FUJIFILM Wako Pure Chemical Corporation), 56.2 g of pure water, and 71.5 g of 25 mass % aqueous NaOH solution, and the mixture was stirred at a reaction temperature of 70° C. After stirring for 5 hours, the organic layer was washed with 1M aqueous hydrochloric acid solution and then with pure water until the pH reached 7. The resultant solution was concentrated, and then added dropwise to methanol for solidification. Subsequently, a low molecular weight compound (compound having a molecular weight of 400 or less) containing a chlorine atom and/or a bromine atom was removed, and the solid was collected by filtration, followed by vacuum drying to produce a solid resin.


The produced resin represented by Formula (T-St) (styrene resin (B)) had an Mw of 2060, an Mn of 1520, and an Mw/Mn of 1.36. In Formula (Tx-St), n+o+p was 5.6, the OH equivalent was 72600 g/eq., and the sum of total Cl and total Br was 320 ppm by mass.


Mn and Mw were measured according to the above-described method. The number of repeating units was calculated from the value of Mn.


Physical Properties

The physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 1.


Example 3
<Synthesis of Hydroxy Resin (C)>

A hydroxy resin (C) was produced in the same manner as in Synthesis of hydroxy resin (A) of Example 1 except that the resin (T-A) was changed to the resin (T-B).


The produced resin represented by Formula (T-OH) (hydroxy resin (C)) had an Mw of 1551, an Mn of 1105, and an Mw/Mn of 1.40. In Formula (Tx-OH), the parameter α was 0.90, n+o+p was 4.4, and the OH equivalent was 556 g/eq.


Synthesis of Styrene Resin (C)

A reactor equipped with a stirrer, a thermometer, and a reflux tube was charged with 100 g of the hydroxy resin (C) produced above, 400 g of toluene, 30.20 g (0.198 mol) of vinylbenzyl chloride (“CMS-14” available from AGC SEIMI CHEMICAL CO., LTD.), 23.19 g (0.07 mol) of tetrabutylammonium bromide (available from FUJIFILM Wako Pure Chemical Corporation), 67.8 g of pure water, and 86.3 g of 25 mass % aqueous NaOH solution, and the mixture was stirred at a reaction temperature of 70° C. After stirring for 5 hours, the organic layer was washed with 1M aqueous hydrochloric acid solution and then with pure water until the pH reached 7. The resultant solution was concentrated, and then added dropwise to methanol for solidification. Subsequently, a low molecular weight compound (compound having a molecular weight of 400 or less) containing a chlorine atom and/or a bromine atom was removed, and the solid was collected by filtration, followed by vacuum-drying to produce a solid resin.


The produced resin represented by Formula (T-St) (styrene resin (C)) had an Mw of 1820, an Mn of 1330, and an Mw/Mn of 1.37. In Formula (Tx-St), the parameter α was 0.90, n+o+p was 4.4, the OH equivalent was 84600 g/eq., and the sum of total Cl and total Br was 200 ppm by mass.


Mn and Mw were measured according to the above-described method. The number of repeating units was calculated from the value of Mn.


Physical Properties

The physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 1.


Example 4
Synthesis of Hydroxy Resin (D)

A hydroxy resin (D) was produced in the same manner as in Synthesis of hydroxy resin (A) of Example 1 except that the resin (T-A) was changed to the resin (T-B), toluene as a reaction solvent was changed to chlorobenzene, and the reaction temperature was changed to 130° C.


The produced resin represented by Formula (T-OH) (hydroxy resin (D)) had an Mw of 1945, an Mn of 1368, and an Mw/Mn of 1.42. In Formula (Tx-OH), the parameter α was 0.90, n+o+p was 6.1, and the OH equivalent was 690 g/eq.


Synthesis of Styrene Resin (D)

A reactor equipped with a stirrer, a thermometer, and a reflux tube was charged with 100 g of the hydroxy resin (D) produced above, 400 g of toluene, 24.33 g (0.159 mol) of vinylbenzyl chloride (“CMS-14” available from AGC SEIMI CHEMICAL CO., LTD.), 18.69 g (0.06 mol) of tetrabutylammonium bromide (available from FUJIFILM Wako Pure Chemical Corporation), 54.7 g of pure water, and 69.6 g of 25 mass % aqueous NaOH solution, and the mixture was stirred at a reaction temperature of 70° C. After stirring for 5 hours, the organic layer was washed with 1M aqueous hydrochloric acid solution and then with pure water until the pH reached 7. The resultant solution was concentrated, and then added dropwise to methanol for solidification. Subsequently, a low molecular weight compound (compound having a molecular weight of 400 or less) containing a chlorine atom and/or a bromine atom was removed, and the solid was collected by filtration, followed by vacuum drying to produce a solid resin.


The produced resin represented by Formula (T-St) (hydroxy resin (D)) had an Mw of 2270, an Mn of 1600, and an Mw/Mn of 1.42. In Formula (Tx-St), the parameter α was 0.91, n+o+p was 6.1, the OH equivalent was 76200 g/eq., and the sum of total Cl and total Br was 220 ppm by mass.


Mn and Mw were measured according to the above-described method. The number of repeating units was calculated from the value of Mn.


Physical Properties

The physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 1.


Example 5
Synthesis of Resin (T-E)

A three-necked flask equipped with a thermometer and a cooling tube was charged with 520 g of toluene, 3 g of activated clay, and a stirring bar, and the mixture was heated to an internal temperature of 70° C. while being stirred. Thereafter, 150 g of 1,3-diisopropenylbenzene (available from Tokyo Chemical Industry) was added dropwise while a dropping rate was controlled so that the internal temperature did not exceed 80° C. After the dropwise addition, the mixture was stirred until the internal temperature decreased to 70° C., 150 g of 1,3-diisopropenylbenzene (available from Tokyo Chemical Industry) was added dropwise in the same manner, and the reaction was allowed to proceed for 2 hours after completion of the dropwise addition. At the end of the reaction, 433 g of toluene was added, and the activated clay was removed by filtration. The solvent was distilled off from the filtrate under heating and reduced pressure to produce 231 g of a solid resin.


The produced resin represented by Formula (T) (resin (T-E)) had an Mw of 2674, an Mn of 1153, and an Mw/Mn of 2.32. In Formula (Tx), the parameter α was 0.71, the parameter β was 0.50, and n+o+p was 6.3. It was confirmed that the amount of a residual monomer was 1 mass % or less by GPC analysis.


Synthesis of Hydroxy Resin (E)

A hydroxy resin (E) was produced in the same manner as in Synthesis of hydroxy resin (A) of Example 1 except that the resin (T-A) was changed to the resin (T-E), toluene as a reaction solvent was changed to chlorobenzene, and the reaction temperature was changed to 130° C.


The produced resin represented by Formula (T-OH) (hydroxy resin (E)) had an Mw of 2229, an Mn of 1411, and an Mw/Mn of 1.58. In Formula (Tx-OH), n+o+p was 6.4, and the OH equivalent was 860 g/eq.


Synthesis of Styrene Resin (E)

A reactor equipped with a stirrer, a thermometer, and a reflux tube was charged with 100 g of the hydroxy resin (E) produced above, 400 g of toluene, 19.52 g (0.128 mol) of vinylbenzyl chloride (“CMS-14” available from AGC SEIMI CHEMICAL CO., LTD.), 14.99 g (0.05 mol) of tetrabutylammonium bromide (available from FUJIFILM Wako Pure Chemical Corporation), 43.9 g of pure water, and 55.8 g of 25 mass % aqueous NaOH solution, and the mixture was stirred at a reaction temperature of 70° C. After stirring for 5 hours, the organic layer was washed with 1M aqueous hydrochloric acid solution and then with pure water until the pH reached 7. The resultant solution was concentrated, and then added dropwise to methanol for solidification. Subsequently, a low molecular weight compound (compound having a molecular weight of 400 or less) containing a chlorine atom and/or a bromine atom was removed, and the solid was collected by filtration, followed by vacuum drying to produce a solid resin.


The produced resin represented by Formula (T-St) (styrene resin (E)) had an Mw of 2360, an Mn of 1650, and an Mw/Mn of 1.43. In Formula (Tx-St), n+o+p was 6.4, the OH equivalent was 55600 g/eq., and the sum of total Cl and total Br was 240 ppm by mass.


Mn and Mw were measured according to the above-described method. The number of repeating units was calculated from the value of Mn.


Physical Properties

The physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 1.


Comparative Example 1
Synthesis of Hydroxy Resin (F)

According to Example 1 of JP 6-172242 A, synthesis was performed as follows.


A 2-liter four-necked round-bottom flask equipped with a thermometer, a stirrer, and a drain tube having a reflux condenser was charged with 549.0 g (4.5 mol) of 2,6-xylenol, 291.0 g (1.5 mol) of m-bis(α-hydroxyisopropyl)benzene, 840 g of toluene, and 84 g of acid clay (montmorillonite K10), and the temperature was raised to 110° C. and held for 8 hours while water was removed azeotropically. The mixture was concentrated with heating under reduced pressure to distill off the volatile matter, and then diluted with toluene, and the acid clay was removed by filtration. The filtrate was collected and concentrated with heating under reduced pressure to produce a resinous solid.


The produced resin (hydroxy resin (F)) had an Mw of 920, an Mn of 770, and an Mw/Mn of 1.19. In Formula (Tx-OH), n+o+p was 2.3, and the OH equivalent was 360 g/eq.


Mn and Mw were measured according to the above-described method. The number of repeating units was calculated from the value of Mn.


Synthesis of Styrene Resin (F)

According to Example 3 of JP 6-172242 A, synthesis was performed as follows.


A 2-liter four-necked round-bottom flask equipped with a thermometer, a stirrer, a reflux condenser, and a dropping funnel was charged with 90.0 g (0.25 mol eq) of the hydroxy resin (F) produced above, 150 ml of dimethyl sulfoxide, and 150 ml of tetrahydrofuran, and the mixture was dissolved at 40° C. 10.4 g (0.26 mol eq) of powdered NaOH and 161 mg of methylhydroquinone were added, and the mixture was stirred at 40° C. for 1 hour. While the temperature was maintained at 40° C., 39.7 g (0.26 mol eq) of p-chloromethylstyrene (trade name: CMS-14, available from SEIMI CHEMICAL CO., LTD.) was added dropwise over 1 hour, and the temperature was raised to 80° C. and held for 14 hours. The reaction solution was diluted with 300 g of toluene, filtered to remove the salt, and then washed with water, and the organic layer was dried over anhydrous sodium sulfate. The salt was removed by filtration, and the mixture was concentrated with heating under reduced pressure to produce a resinous product.


The produced resin (styrene resin (F)) had an Mw of 1150, an Mn of 995, and an Mw/Mn of 1.16. In Formula (Tx-St), n+o+p was 2.3, the OH equivalent was 27200 g/eq., and the sum of total Cl and total Br was 3850 ppm by mass.


Physical Properties

The physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 1.


Comparative Example 2
Synthesis of Styrene Resin (G)

The styrene resin (F) produced in Comparative Example 1 was dissolved in heptane, and the solution was added dropwise to methanol for solidification. Subsequently, a low molecular weight compound (compound having a molecular weight of 400 or less) containing a chlorine atom and/or a bromine atom was removed, and the solid was collected by filtration, followed by vacuum drying to produce a solid resin (styrene resin (G)).


The produced resin (styrene resin (G)) had an Mw of 1170, an Mn of 1005, and an Mw/Mn of 1.16. In Formula (Tx-St), n+o+p was 2.3, the OH equivalent was 27500 g/eq., and the sum of total Cl and total Br was 470 ppm by mass.


Physical Properties

The physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 1.


















TABLE 1








Example
Example
Example
Example
Example
Comparative
Comparative



Unit
1
2
3
4
5
Example 1
Example 2

























Resin
Mn

713
693
693
693
1153




(T)
Mw

1336
1193
1193
1193
2674





Number of

3.5
3.4
3.4
3.4
6.3





repeating units



Mw/Mn

1.87
1.72
1.72
1.72
2.32





α

0.70
0.63
0.63
0.63
0.71





β

0.92
1.07
1.07
1.07
0.50




Hydroxy
OH equivalent
g/eq.
571
671
556
690
860
360
360


resin
Reaction
° C.
70° C.
110° C.
70° C.
130° C.
130° C.
110° C.
110° C.



temperature














Reaction

Toluene
Chlorobenzene
Toluene
Toluene

















solvent











Mn

1090
1290
1105
1368
1411
770
770



Mw

1604
1730
1551
1945
2229
920
920



Mw/Mn

1.47
1.34
1.40
1.42
1.58
1.19
1.19



Number of

4.3
5.6
4.4
6.1
6.4
2.3
2.3



repeating units



Yield
g
125.0
119.6
124.5
118.1
117.3
142.0
142.0


Styrene
Type

A
B
C
D
E
F
G


resin
Presence or

Presence
Presence
Presence
Presence
Presence
Absence
Presence



absence of



CMS removal



step



Total Cl + Br
ppm
250
320
200
220
240
3850
470



OH equivalent
g/eq.
25500
72600
84600
76200
55600
27200
27500



Mn

1320
1520
1330
1600
1650
995
1005



Mw

1800
2060
1820
2270
2360
1150
1170



Mw/Mn

1.36
1.36
1.37
1.42
1.43
1.16
1.16



Number of

4.3
5.6
4.4
6.1
6.4
2.3
2.3



repeating units



Yield
g
108.3
106.8
108.8
105.2
102.2
120.6
107.1


Physical
Tg (DMA
° C.
215
211
216
222
206
212
216


properties
bending, E″)



Dk @10 GHz

2.30
2.31
2.32
2.31
2.29
2.38
2.38



Df @10 GHz

0.0020
0.0016
0.0019
0.0015
0.0017
0.0052
0.0032










FIG. 1 illustrates an NMR chart of the hydroxy resin (C) synthesized in Example 3. FIG. 2 illustrates an NMR chart of the styrene resin (C) synthesized in Example 3. FIG. 3 illustrates a GPC chart of the styrene resin (C) synthesized in Example 3.


Example 6
Synthesis of Hydroxy Resin (F)

A reactor equipped with a stirrer, a thermometer, and a cooling tube was charged with 100 g of the resin (T-B), 400 g of chlorobenzene, 100 g of phenol, and 10 g of activated clay, and the mixture was heated to an internal temperature of 130° C. while being stirred. The mixture was further reacted at an internal temperature of 130° C. for 3 hours. After cooling, the activated clay was removed by filtration, and washing was performed twice with 1M aqueous sodium hydroxide solution to remove remaining phenol. The washing was repeated with pure water until neutral pH was achieved, and then the solvent was distilled off with heating under reduced pressure to produce a solid resin.


The produced resin represented by Formula (T-1-OH) (resin represented by Formula (T-OH), hydroxy resin (F)) had an Mw of 2100, an Mn of 1355, a parameter α of 0.86, and an Mw/Mn of 1.55. In Formula (Tx-OH), n+o+p was 6.4, and the OH equivalent was 680 g/eq.


Mn and Mw were measured according to the above-described method. The number of repeating units was calculated from the value of Mn.


A reactor equipped with a stirrer, a thermometer, and a reflux tube was charged with 100 g of the hydroxy resin (F) produced above, 400 g of toluene, 24.69 g (0.162 mol) of vinylbenzyl chloride (“CMS-14” available from AGC SEIMI CHEMICAL CO., LTD.), 18.96 g (0.06 mol) of tetrabutylammonium bromide (available from FUJIFILM Wako Pure Chemical Corporation), 56 g of pure water, and 71 g of 25 mass % aqueous NaOH solution, and the mixture was stirred at a reaction temperature of 70° C. After stirring for 5 hours, the organic layer was washed with 1M aqueous hydrochloric acid solution and then with pure water until the pH reached 7. The resultant solution was concentrated, and then added dropwise to methanol for solidification. Subsequently, a low molecular weight compound (compound having a molecular weight of 400 or less) containing a chlorine atom and/or a bromine atom was removed, and the solid was collected by filtration, followed by vacuum drying to produce a solid resin.


The produced resin represented by Formula (T-1-St) (resin represented by Formula (T-St), styrene resin (F)) had an Mw of 2300, an Mn of 1600, and an Mw/Mn of 1.44. In Formula (Tx-St), the parameter α was 0.88, n+o+p was 6.5, the OH equivalent was 28500 g/eq., and the sum of total Cl and total Br was 170 ppm by mass.


Mn and Mw were measured according to the above-described method. The number of repeating units was calculated from the value of Mn.


Physical Properties

The physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 2.


Example 7
Synthesis of Hydroxy Resin (G)

A reactor equipped with a stirrer, a thermometer, and a cooling tube was charged with 100 g of the resin (T-B), 400 g of chlorobenzene, 122 g of 2-benzylphenol, and 40 g of activated clay, and the mixture was heated to an internal temperature of 130° C. while being stirred. The mixture was further reacted at an internal temperature of 130° C. for 3 hours. After cooling, the activated clay was removed by filtration, and washing was performed twice with 1M aqueous sodium hydroxide solution to remove remaining phenol. The washing was repeated with pure water until neutral pH was achieved, and then the solvent was distilled off with heating under reduced pressure to produce a solid resin.


The produced resin represented by Formula (T-1-OH) (resin represented by Formula (T-OH), hydroxy resin (G)) had an Mw of 2110, an Mn of 1120, and an Mw/Mn of 1.88. In Formula (Tx-OH), n+o+p was 3.8, and the OH equivalent was 560 g/eq.


Mn and Mw were measured according to the above-described method. The number of repeating units was calculated from the value of Mn.


A reactor equipped with a stirrer, a thermometer, and a reflux tube was charged with 100 g of the hydroxy resin (G) produced above, 400 g of toluene, 29.98 g (0.196 mol) of vinylbenzyl chloride (“CMS-14” available from AGC SEIMI CHEMICAL CO., LTD.), 23.03 g (0.07 mol) of tetrabutylammonium bromide (available from FUJIFILM Wako Pure Chemical Corporation), 67 g of pure water, and 86 g of 25 mass % aqueous NaOH solution, and the mixture was stirred at a reaction temperature of 70° C. After stirring for 5 hours, the organic layer was washed with 1M aqueous hydrochloric acid solution and then with pure water until the pH reached 7. The resultant solution was concentrated, and then added dropwise to methanol for solidification. Subsequently, a low molecular weight compound (compound having a molecular weight of 400 or less) containing a chlorine atom and/or a bromine atom was removed, and the solid was collected by filtration, followed by vacuum drying to produce a solid resin.


The produced resin represented by Formula (T-1-St) (resin represented by Formula (T-St), styrene resin (G)) had an Mw of 2350, an Mn of 1370, and an Mw/Mn of 1.72. In Formula (Tx-St), the parameter α was 0.86, n+o+p was 3.9, the OH equivalent was 39600 g/eq., and the sum of total Cl and total Br was 320 ppm by mass.


Mn and Mw were measured according to the above-described method. The number of repeating units was calculated from the value of Mn.


Physical Properties

The physical properties were evaluated in the same manner as in Example 1. The results are shown in Table 2.













TABLE 2







Unit
Example 6
Example 7




















Resin (T)
Mn

693
693



Mw

1193
1193



Number of repeating

3.4
3.4



units



Mw/Mn

1.72
1.72



α

0.63
0.63



β

1.07
1.07


Hydroxy
OH equivalent
g/eq.
680
560


resin
Reaction temperature
° C.
130° C.
130° C.











Reaction solvent

Chlorobenzene












Mn

1355
1120



Mw

2100
2110



Mw/Mn

1.55
1.88



Number of repeating

6.4
3.8



units



Yield
g
118.3
124.0


Styrene
Type

H
I


resin
Presence or absence of

Presence
Presence



CMS removal step



Total Cl + Br
ppm
170
320



OH equivalent
g/eq.
28500
39600



Mn

1600
1370



Mw

2300
2350



Mw/Mn

1.44
1.72



Number of repeating

6.5
3.9



units



Yield
g
107.7
109.6


Physical
Tg (DMA bending, E″)
° C.
203
185


properties
Dk @10 GHz

2.28
2.35



Df @10 GHz

0.0026
0.0014








Claims
  • 1. A hydroxy resin represented by Formula (T-OH) and having a number average molecular weight of 850 to 4000;
  • 2. The hydroxy resin according to claim 1, wherein the number average molecular weight is 900 to 2500.
  • 3. The hydroxy resin according to claim 1, wherein Formula (T-OH) is represented by Formula (T-OH2);
  • 4. A styrene resin represented by Formula (T-St) and having a number average molecular weight of 1050 to 4000;
  • 5. The styrene resin according to claim 4, wherein Formula (T-St) is represented by Formula (T-St2);
  • 6. The styrene resin according to claim 4, wherein the number average molecular weight is 1050 to 2500.
  • 7. The styrene resin according to claim 4, wherein a sum of a total chlorine amount and a total bromine amount is 2500 ppm by mass or less.
  • 8. The styrene resin according to claim 4, wherein a cured product of the styrene resin has a dielectric loss tangent of 0.0030 or less at a frequency of 10 GHz.
  • 9. A method for producing the hydroxy resin described in claim 1, the method comprising using a resin (T), wherein the resin (T) is a resin represented by Formula (T);
  • 10. The method for producing the hydroxy resin according to claim 9, the method comprising reacting the resin (T) with a compound represented by Formula (P);
  • 11. The method for producing the hydroxy resin according to claim 10, wherein the compound represented by the Formula (P) contains a compound represented by Formula (P1);
  • 12. The method for producing the hydroxy resin according to claim 10, wherein, in a reaction system for reacting the resin (T) with a compound represented by Formula (P), a total content of m-bis(α-hydroxyisopropyl)benzene, p-bis(α-hydroxyisopropyl)benzene, 1,3-diisopropenylbenzene, and 1,4-diisopropenylbenzene is 10 mass % or less relative to an amount of the resin (T).
  • 13. A method for producing the styrene resin described in claim 4, the method comprising using a hydroxy resin represented by Formula (T-OH) and having a number average molecular weight of 850 to 4000;
  • 14. The method for producing the styrene resin according to claim 13, the method comprising reacting the hydroxy resin with a compound represented by Formula (S);
  • 15. A resin composition comprising the styrene resin described in claim 4.
  • 16. A cured product of the resin composition described in claim 15.
  • 17. A prepreg formed from a substrate and the resin composition described in claim 15.
  • 18. A metal foil-clad laminate comprising: at least one layer formed from the prepreg described in claim 17; anda metal foil disposed on one surface or both surfaces of the layer formed from the prepreg.
  • 19. A resin composite sheet comprising: a support; anda layer disposed on a surface of the support, the layer being formed from the resin composition described in claim 15.
  • 20. A printed wiring board comprising: an insulating layer; anda conductor layer disposed on a surface of the insulating layer,wherein the insulating layer includes a layer formed from the resin composition described in claim 15.
  • 21. A semiconductor device comprising the printed wiring board described in claim 20.
  • 22. The resin composition according to claim 15, which comprises at least one or more selected from the group consisting of ultraviolet absorbers, antioxidants, photopolymerization initiators, fluorescent whitening agents, photosensitizers, dyes, pigments, thickeners, flow control agents, lubricants, antifoaming agents, leveling agents, brighteners, and polymerization inhibitors.
Priority Claims (1)
Number Date Country Kind
2022-039678 Mar 2022 JP national
PCT Information
Filing Document Filing Date Country Kind
PCT/JP2023/009587 3/13/2023 WO