Patent Application
20220002567
The present invention relates to a composition including silica particles, a film formed of the composition including silica particles, and a method of forming the same.
For example, an optical functional layer such as a low refractive index film is applied to a surface of a transparent substrate in order to prevent reflection of light to be incident. The application field of the optical functional layer is wide, and the optical functional layer is applied to products in various fields such as optical devices, construction materials, observation instruments, or window glass. As the material of the optical functional layer, various materials including not only organic materials but also inorganic materials are used and are targets to be developed. In particular, recently, the development of materials to be applied to the optical devices has progressed. Specifically, the search of materials having physical properties or workability suitable for a display panel, an optical lens, or an image sensor has progressed.
An optical functional layer that is applied to a precision optical device such as an image sensor is required to have fine and accurate processing formability. Therefore, in the related art, a gas phase method such as a vacuum deposition method or a sputtering method that is suitable for microfabrication has been adopted. As a material used in the gas phase method, for example, a single-layer film formed of MgF2 or cryolite has been put into practice. In addition, the application of a metal oxide such as SiO2, TiO2, or ZrO2 has also been attempted.
On the other hand, in the gas phase method such as a vacuum deposition method or a sputtering method, the device and the like are expensive, and thus the manufacturing costs may be high. Accordingly, recently, the manufacturing of the optical functional layer such as a low refractive index film using a composition including silica particles has been investigated (refer to JP2015-166449A, WO2015/190374A, and WO2019/017280A).
The present inventor conducted a further investigation on the composition including silica particles and found that, in a case where a composition including silica particles is applied using a spin coating method, wave-like coating unevenness may occur on the surface. This way, there is room for further improvement for the use of the composition including silica particles.
In addition, after forming a film using the composition including silica particles, another composition for forming a film such as a composition for forming a. top coat layer may also be applied to this film. Therefore, in a case where another composition for forming a film is applied to the film that is formed of the composition including silica particles, it is also desirable that coating properties of the other composition for forming a film are excellent.
Accordingly, an object of the present invention is to provide a composition with which a film having excellent coating properties of another composition for forming a film and having suppressed occurrence of wave-like coating unevenness, a film, and a film forming method.
According to the investigation, the present inventors found that the object can be achieved using a composition described below; thereby completing the present invention. Accordingly, the present invention provides the following.
<1> A composition comprising:
silica particles;
a silicone-based surfactant; and
a solvent,
in which a content of the silicone-based surfactant in the composition is 0.01 to 0.30 mass %, and
in a case where the composition is applied to a silicon wafer and is heated at 200° C. for 5 minutes to form a film having a thickness of 0.3 μm, a refractive index of the film with respect to light having a wavelength of 633 nm is 1.4 or lower.
<2> A composition comprising:
silica particles;
a silicone-based surfactant; and
a solvent,
in which a content of the silicone-based surfactant is 0.05 to 5.00 mass % with respect to a total solid content of the composition, and
in a case where the composition is applied to a silicon wafer and is heated at 200° C. for 5 minutes to form a film having a thickness of 0.3 μm, a refractive index of the film with respect to light having a wavelength of 633 nm is 1.4 or lower.
<3> A composition comprising:
silica particles;
a silicone-based surfactant; and
a solvent,
in which a content of the silicone-based surfactant in the composition is 0.01 to 0.30 mass %, and
the silica particles include at least one kind of silica particles selected from silica particles having a shape in which a plurality of spherical silica particles are linked in a beaded shape, silica particles having a shape in which a plurality of spherical silica particles are linked in a planar shape, and silica particles having a hollow structure.
<4> A composition comprising:
silica particles;
a silicone-based surfactant; and
a solvent,
in which a content of the silicone-based surfactant is 0.05 to 5.00 mass % with respect to a total solid content of the composition, and
the silica particles include at least one kind of silica particles selected from silica particles having a shape in which a plurality of spherical silica particles are linked in a beaded shape, silica particles having a shape in which a plurality of spherical silica particles are linked in a planar shape, and silica particles having a hollow structure.
<5> The composition according to any one of <1> to <4>,
in which a content of the silicone-based surfactant is 0.3 to 5.5 parts by mass with respect to 100 parts by mass of the silica particles.
<6> The composition according to any one of <1> to <5>,
in which the silica particles include at least one kind of silica particles selected from silica, particles having a shape in which a plurality of spherical silica particles are linked in a beaded shape and silica particles having a shape in which a plurality of spherical silica particles are linked in a planar shape.
<7> The composition according to any one of <1> to <6>,
in which a content of the silica particles is 50 mass % or higher with respect to a total solid content of the composition.
<8> The composition according to any one of <1> to <7>,
in which the silicone-based surfactant is a modified silicone compound.
<9> The composition according to any one of <1> to <8>,
in which a kinetic viscosity of the silicone-based surfactant at 25° C. is 20 to 3000 mm2/s.
<10> The composition according to any one of <1> to <9>,
in which in a case where 0.1 g of the silicone-based surfactant is dissolved in 100 g of propylene glycol monomethyl ether acetate to prepare a solution, a surface tension of the solution at 25° C. is 19.5 to 26.7 mN/m.
<11> The composition according to any one of <1> to <10>,
in which a surface tension of the composition at 25° C. is 27.0 mN/m or lower.
<12> The composition according to any one of <1> to <11>,
in which in a case where the composition is applied to a glass substrate and is heated at 200° C. for 5 minutes to form a film having a thickness of 0.5 μm, a contact angle of the film with water at 25° C. is 20° or more.
<13> A film which is formed using the composition according to any one of <1> to <12>.
<14> A film forming method comprising:
a step of applying the composition according to any one of <1> to <12> to a support using a spin coating method.
According to the present invention it is possible to provide a composition with which a film having excellent coating properties of another composition for forming a film and having suppressed occurrence of wave-like coating unevenness, a film, and a film forming method.
Hereinafter, the details of the present invention will be described.
In the present specification, numerical ranges represented by “to” include numerical values before and after “to” as lower limit values and upper limit values.
In the present specification, unless specified as a substituted group or as an unsubstituted group, a group (atomic group) denotes not only a group (atomic group) having no substituent but also a group (atomic group) having a substituent. For example, “alkyl group” denotes 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, unless specified otherwise, “exposure” denotes not only exposure using light but also drawing using a corpuscular beam such as an electron beam or an ion beam. Examples of the light used for exposure include an actinic ray or radiation, for example, a bright light spectrum of a mercury lamp, a far ultraviolet ray represented by excimer laser, an extreme ultraviolet ray (EUV ray), an X-ray, or an electron beam.
In the present specification, “(meth)acrylate” denotes either or both of acrylate and methacrylate, “(meth)acryl” denotes either or both of acryl and methacryl, and “(meth)acryloyl” denotes either or both of acryloyl and methacryloyl.
In the present specification, a weight-average molecular weight and a number-average molecular weight are defined as values in terms of standard polystyrene measured by gel permeation chromatography (GPC). As a measuring device and measurement conditions, the following condition 1 is basically used, and the following condition 2 is allowed depending on the solubility of a sample or the like. In this case, depending on the kind of a polymer, a more appropriate carrier (eluent) and a column suitable for the carrier may be selected and used. Other features can be found in JIS K 7252-1 to 4:2008.
(Condition 1)
Column: a column in which TOSOH TSK gel Super HZM-H, TOSOH TSK gel Super HZ4000, and TOSOH TSK gel Super HZ2000 are linked to each other
Carrier: tetrahydrofuran
Measurement temperature: 40° C.
Carrier flow rate: 1.0 ml/min
Sample concentration: 0.1 mass %
Detector: refractive index (RI) detector
Injection volume: 0.1 ml
(Condition 2)
Column: a column in which two TOSOH TSK gel Super AWM-H's are linked
Carrier: 10 mM LiBr/N-methylpyrrolidone
Measurement temperature: 40° C.
Carrier flow rate: 1.0 ml/min
Sample concentration: 0.1 mass %
Detector: refractive index (RI) detector
Injection volume: 0.1 ml
<Composition>
A first aspect of a composition according to an embodiment of the present invention comprises:
silica particles;
a silicone-based surfactant; and
a solvent,
in which a content of the silicone-based surfactant in the composition is 0.01 to 0.30 mass %, and
in a case where the composition is applied to a silicon wafer and is heated at 200° C. for 5 minutes to form a film having a thickness of 0.3 μm, a refractive index of the film with respect to light having a wavelength of 633 nm is 1.4 or lower.
In addition, a second aspect of a composition according to an embodiment of the present invention comprises:
silica particles;
a silicone-based surfactant; and
a solvent,
in which a content of the silicone-based surfactant is 0.05 to 5.00 mass % with respect to a total solid content of the composition, and
in a case where the composition is applied to a silicon wafer and is heated at 200° C. for 5 minutes to form a film having a thickness of 0.3 μm, a refractive index of the film with respect to light having a wavelength of 633 nm is 1.4 or lower.
In addition, a third aspect of a composition according to an embodiment of the present invention comprises:
silica particles;
a silicone-based surfactant; and
a solvent,
in which a content of the silicone-based surfactant in the composition is 0.01 to 0.30 mass %, and
the silica particles include at least one kind of silica particles selected from silica particles having a shape in which a plurality of spherical silica particles are linked in a beaded shape, silica particles having a shape in which a plurality of spherical silica particles are linked in a planar shape, or silica particles having a hollow structure.
In addition, a fourth aspect of a composition according to an embodiment of the present invention comprises:
silica particles;
a silicone-based surfactant; and
a solvent,
in which a content of the silicone-based surfactant is 0.05 to 5.00 mass % with respect to a total solid content of the composition, and
the silica particles include at least one kind of silica particles selected from silica particles having a shape in which a plurality of spherical silica particles are linked in a beaded shape, silica particles having a shape in which a plurality of spherical silica particles are linked in a planar shape, or silica particles having a hollow structure.
In the composition according to the embodiment of the present invention, a composition including silica particles and a solvent includes a silicone-based surfactant at the above-described proportion. As a result, in a case where this composition is applied using a spin coating method, the occurrence of wave-like coating unevenness on the surface can be suppressed, and a film having excellent surface shape can be formed. In addition, the content of the silicone-based surfactant is in the above-described range. Therefore, even in a case where another composition for forming a film is applied to a film that is formed of the composition according to the embodiment of the present invention, coating unevenness or the like is not likely to occur, and a film having excellent coating properties of the other composition for forming a film can be formed. Further, by using the composition according to the embodiment of the present invention, a film having a low refractive index can be formed. In general, it is known that a fluorine-based surfactant has a higher effect of decreasing the surface tension than a silicone-based surfactant. It is presumed that, by using the surfactant having a high effect of decreasing the surface tension, coating properties are improved. However, as shown in Examples described below, even in a case where a fluorine-based surfactant is used, the occurrence of wave-like coating unevenness cannot be sufficiently suppressed. The effect that, in a case where a composition including silica particles and a solvent includes a silicone-based surfactant at the above-described proportion, a film having excellent coating properties of another composition for forming a film and having suppressed occurrence of wave-like coating unevenness can be obtained is an effect that is unexpected and surprising to even those skilled in the art.
In addition, in a case where a film is formed using the composition according to the embodiment of the present invention to obtain a film and subsequently another composition for forming a film is applied to come into contact with the obtained film to form another film, transfer of components in the other composition for forming a film to the film obtained of the composition according to the embodiment of the present invention can be suppressed, and the occurrence of foreign matter or the like can be suppressed. The detailed reason why this effect can be obtained is not clear but is presumed to be as follows. Since the film formed of the composition according to the embodiment of the present invention has high affinity to the silica particles and the silicone-based surfactant, an interaction or the like between the silica particles and components in another composition for forming a film can be suppressed. Therefore, transfer of components in the other composition for forming a film to the film obtained of the composition according to the embodiment of the present invention can be suppressed.
As a quantitative evaluation method for coating uniformity of the composition on a support, point measurement can be performed using a film thickness measuring instrument or the like. Regarding coating properties (such as striation) on a support having a step, a change in the intensity of reflected light caused by interference may be evaluated using a line scan camera that detects light that is specularly reflected from a support. In the evaluation using the line scan camera, the speed of a stage for continuous processing, the magnification of a lens, and the irradiation light of an illumination can be freely selected.
The viscosity of the composition according to the embodiment of the present invention at 25° C. is preferably 3.6 mPa·s or lower, more preferably 3.4 mPa·s or lower, and still more preferably 3.2 mPa·s or lower. The lower limit is preferably 1.0 mPa·s or higher, more preferably 1.4 mPa·s or higher, and still more preferably 1.8 mPa·s or higher. In a case where the viscosity of the composition is in the above-described range, the coating properties of the composition are improved such that a film having suppressed occurrence of wave-like coating unevenness can be easily obtained.
The concentration of solid contents in the composition according to the embodiment of the present invention is preferably 5 mass % or higher, more preferably 7 mass % or higher, and still more preferably 8 mass % or higher. The upper limit is preferably 15 mass % or lower, more preferably 12 mass % or lower, and still more preferably 10 mass % or lower. In a case where the concentration of solid contents in the composition according to the embodiment of the present invention is in the above-described range, a film having suppressed occurrence of wave-like coating unevenness can be easily obtained.
From the viewpoint of stabilizing dispersion of the silica particles in the composition and easily suppressing the occurrence of aggregated foreign matter, an absolute value of a zeta potential of the composition according to the embodiment of the present invention is preferably 25 mV or higher, more preferably 29 mV or higher, still more preferably 33 mV or higher, and still more preferably 37 mV or higher. The upper limit of the absolute value of the zeta potential is preferably 90 mV or lower, more preferably 80 mV or lower, and still more preferably 70 mV or lower. In addition, from the viewpoint of easily stabilizing dispersion of the silica particles in the composition, the zeta potential of the present invention is preferably −70 to −25 mV. The lower limit is preferably −60 mV or higher, more preferably −50 mV or higher, and still more preferably −45 mV or higher. The upper limit is preferably −28 mV or lower, more preferably −31 mV or lower, and still more preferably −34 mV or lower. In a case where the potential of an electrically neutral solvent portion that is sufficiently spaced from the particles in the tine particle dispersion liquid is zero, the zeta potential refers to a potential on an internal plane (slipping plane) of an electric double layer that moves together with particles among potentials developed by surface charge of the particles and the electric double layer derived from the vicinity of the surface. In addition, in the present specification, the zeta potential of the composition is a value measured by electrophoresis. Specifically, the electrophoretic mobility of fine particles are measured using a zeta potential measuring device (Zetasizer Nano, manufactured by Malvern Panalytical Ltd.), and the zeta potential is measured from the Debye-Huckel equation. As measurement conditions, a universal dip cell is used, a voltage at which particles appropriately migrate even after application of a voltage of 40 V or 60 V is selected, and an attenuator and an analysis model are set to an automatic mode, the measurement is repeated 20 times, and the average value thereof is obtained as the zeta potential of a sample. The sample is used as it is without performing a pre-treatment such as dilution thereon.
The surface tension of the composition according to the embodiment of the present invention at 25° C. is preferably 27.0 mN/m or lower, more preferably 26.0 mN/m or lower, still more preferably 25.5 mN/m or lower, and still more preferably 25.0 mN/m or lower. The lower limit is preferably 20.0 mN/m or higher, more preferably 21.0 mN/m or higher, and still more preferably 22.0 mN/m or higher.
In a case where the composition according to the embodiment of the present invention is applied to a glass substrate and is heated at 200° C. for 5 minutes to form a film having a thickness of 0.5 μm, a contact angle of the above-described film with water at 25° C. is preferably 20° or more, more preferably 25° or more, and still more preferably 30° or more from the viewpoint of the stability of the composition. From the viewpoint of the coating properties of the composition, the upper limit is preferably 70° or less, more preferably 65° or less, and still more preferably 60° or less. The contact angle is a value measured using a contact angle meter (DM-701, manufactured by Kyowa Interface Science Co., Ltd.).
In a case where the composition according to the embodiment of the present invention is applied to a silicon wafer and is heated at 200° C. for 5 minutes to form a film having a thickness of 0.3 μm, the refractive index of the above-described film with respect to light having a wavelength of 633 nm is preferably 1.4 or lower, more preferably 1.35 or lower, still more preferably 1.3 or lower, and still more preferably 1.27 or lower. The lower limit is not particularly limited and may be 1.15 or higher. The refractive index is a value using an ellipsometer (VUV-vase (trade name), manufactured by J. A. Woollam Co., Inc.). The measurement temperature is 25° C.
Hereinafter, each component of the composition according to the embodiment of the present invention will be described.
<<Silica Particles>>
The composition according to the embodiment of the present invention includes silica particles. Examples of the silica particles include silica particles having a shape in which a plurality of spherical silica particles are linked in a beaded shape, silica particles having a shape in which a plurality of spherical silica particles are linked in a planar shape, silica particles having a hollow structure, and solid silica particles. Examples of a commercially available product of the solid silica particles include PL-2L-IPA (manufactured by Fuso Chemical Co., Ltd.).
As the silica particles used in the composition according to the embodiment of the present invention, from the viewpoint of easily forming a film having a lower refractive index, silica particles having a shape in which a plurality of spherical silica particles are linked in a beaded shape, silica particles having a shape in which a plurality of spherical silica particles are linked in a planar shape, or silica particles having a hollow structure are preferable, and silica particles having a shape in which a plurality of spherical silica particles are linked in a beaded shape, or silica particles having a shape in which a plurality of spherical silica particles are linked in a planar shape are preferable. Hereinafter, silica particles having a shape in which a plurality of spherical silica particles are linked in a beaded shape and silica particles having a shape in which a plurality of spherical silica particles are linked in a planar shape will also be collectively referred to as “beaded silica particles”. Silica particles having a shape in which a plurality of spherical silica particles are linked in a beaded shape may have a shape in which a plurality of spherical silica particles are linked in a planar shape.
In the present specification, “spherical” of “spherical silica” only has to be substantially spherical and may be deformed within a range where the effect of the present invention can be exhibited. For example, “spherical” refers to not only a shape having unevenness on a surface but also a flat shape having a major axis in a predetermined direction. In addition, “a plurality of spherical silica particles are linked in a beaded shape” refers to a structure in which silica particles having a shape in which a plurality of spherical silica particles are linked in a linear and/or branched shape. For example, a structure in which a plurality of spherical silica particles 1 are linked through bonding portions 2 having a smaller outer diameter than the spherical silica particles 1 as illustrated in
In the beaded silica particles, it is preferable that a ratio D1/D2 of an average particle diameter D1 that is measured using a dynamic light scattering method to an average particle diameter D2 that is obtained by Expression (1) is 3 or higher. The upper limit of the D1/D2 is not particularly limited and is preferably 1000 or lower, more preferably 800 or lower, and still more preferably 500 or lower. By adjusting D1/D2 to be in the above-described range, excellent optical characteristics can be exhibited. The value of D1/D2 in the beaded silica particles is also an index indicating the degree to which the spherical silica particles are linked.
D
2=2720/S (1)
In the expression D2 represents an average particle diameter of the beaded silica particles with a unit of nm and S represents a specific surface area of the beaded silica particles measured using a nitrogen adsorption method with a unit of m2/g.
The average particle diameter D2 of the beaded silica particles can be considered as an average particle diameter similar to that of primary particles of the spherical silica. The average particle diameter D2 is preferably 1 nm or more, more preferably 3 um or more, still more preferably 5 nm or more, and still more preferably 7 nm or more. The upper limit is preferably 100 nm or less, more preferably 80 nm or less, still more preferably 70 nm or less, still more preferably 60 nm or less, and still more preferably 50 nm or less.
The average particle diameter D2 can be replaced with a circle equivalent diameter (D0) of a projection image of a spherical portion measured using a transmission electron microscope (TEM). The average particle diameter as the circle equivalent diameter is evaluated as a number average value of 50 or more particles unless specified otherwise.
The average particle diameter D1 of the beaded silica particles can be considered as a number average particle diameter of secondary particles obtained by aggregation of the plurality of spherical silica particles. Accordingly, typically, a relationship of D1>D2 is satisfied. The average particle diameter D1 is preferably 25 nm or more, more preferably 30 nm or more, and still more preferably 35 nm or more. The upper limit is preferably 1000 nm or less, more preferably 700 nm or less, still more preferably 500 nm or less, and still more preferably 300 nm or less.
Unless specified otherwise, the average particle diameter D1 of the beaded silica particles is measured using a dynamic light scattering particle diameter distribution analyzer (manufactured by Nikkiso Co., Ltd., Nanotrac Wave-EX150 (trade name)). The procedure is as follows 20 ml of a dispersion liquid of beaded silica particles is collected in a sample bottle and is diluted with toluene such that the concentration of solid contents is 0.2 mass %. The diluted sample solution is used for the test immediately after being irradiated with ultrasonic waves of 40 kHz for 1 minute. Data is obtained 10 times using a 2 ml quartz cell for measurement at a temperature of 25° C., and the obtained “number average” is obtained as the average particle diameter. Other detailed conditions and the like can be found in JIS Z8828: 2013 “particle diameter Analysis-Dynamic Light Scattering” as necessary. For each level, five samples are prepared and the average value thereof is adopted.
In the present invention, it is preferable that, in the beaded silica particles, a plurality of spherical silica particles having an average particle diameter of 1 to 80 nm are linked through a linking material. The upper limit of the average particle diameter of the spherical silica particles is preferably 70 nm or less, more preferably 60 nm or less, and still more preferably 50 nm or less. In addition, the lower limit of the average particle diameter of the spherical silica particles is preferably 3 nm or more, more preferably 5 nm or more, and still more preferably 7 nm or more. As the value of the spherical silica particles in the present invention, an average particle diameter that is obtained from a circle equivalent diameter of a projection image of a spherical portion measured using a transmission electron microscope (TEM) is used.
Examples of the linking material through which the spherical silica particles are linked include a metal oxide-containing silica. Examples of the metal oxide include an oxide of a metal selected from Ca, Mg, Sr, Ba, Zn, Sn, Pb, Ni, Co, Fe, Al, In, Y, or Ti. Examples of the metal oxide-containing silica include a reactant and a mixture of the metal oxide and silica (SiO2). The details of the linking material can be found in WO2000/015552A, the content of which is incorporated herein by reference.
The number of spherical silica particles linked in the beaded silica particles is preferably 3 or more and more preferably 5 or more. The upper limit is preferably 1000 or less, more preferably 800 or less, and still more preferably 500 or less. The number of spherical silica particles linked can be measured using a TEM.
As the beaded silica particles, spherical silica particles having a surface treated with hexamethyldisilazane may be used.
As the silica particles, silica particles in a state of a particle solution (sol) may be used. Examples of a medium in which the silica particles are dispersed include an alcohol (for example, methanol, ethanol, or isopropanol), ethylene glycol, a glycol ether (for example, propylene glycol monomethyl ether), and a glycol ether acetate (for example, propylene glycol monomethyl ether acetate). In addition, a solvent A1, a solvent A2, and the like described below can also be used. The SiO2 concentration in the particle solution (sol) is preferably 5 to 40 mass %.
As the particle solution of the beaded silica particles, for example, a silica sol described in JP4328935B can be used. In addition, as the particle solution (sol) of the beaded silica particles, a commercially available product can also be used. Examples of the commercially available product include: “SNOWTEX OUP”, “SNOWTEX UP”, “IPA-ST-UP”, “SNOWTEX PS-M”, “SNOWTEX PS-MO” “SNOWTEX PS-S”, and “SNOWTEX PS-SO” manufactured by Nissan Chemical Industries Ltd.; “FINE CATALOID F-120” manufactured by JGC C&C.; and “QUARTRON PL” manufactured by Fuso Chemical Co., Ltd.
In addition, as the particle solution of the silica particles having a hollow structure, a commercially available product can also be used. Examples of the commercially available product include “THRULYA 4110” (manufactured by JGC C&C).
The content of the silica particles in the composition according to the embodiment of the present invention is preferably 4 mass % or higher, more preferably 6 mass % or higher, and still more preferably 7 mass % or higher. The upper limit is preferably 15 mass % or lower, more preferably 13 mass % or lower, and still more preferably 11 mass % or lower.
In addition, the content of the silica particles is preferably 50 mass % or higher, more preferably 60 mass % or higher, and still more preferably 70 mass % or higher with respect to the total solid content of the composition according to the embodiment of the present invention. The upper limit may be 99.95 mass % or lower, 99.9 mass % or lower, 99 mass % or lower, or 95 mass % or lower. In a case where the content of the silica particles is in the above-described range, a film having a high antireflection effect at a low refractive index and reduced defects can be easily obtained. In addition, in a case where a pattern is not formed or in a case where a pattern is formed using an etching method, the content of the silica particles with respect to the total solid content of the composition according to the embodiment of the present invention is preferably high and is, for example, preferably 95 mass % or higher, more preferably 97 mass % or higher, and still more preferably 99 mass % or higher.
<<Alkoxysilane Hydrolysate>>
It is preferable that the composition according to the embodiment of the present invention includes at least one component (referred to as “alkoxysilane hydrolysate”) selected from the group consisting of alkoxysilane and a hydrolysate of alkoxysilane. The composition according to the embodiment of the present invention includes the alkoxysilane hydrolysate such that the silica particles can be strongly bonded to each other during film formation and an effect of increasing the void volume in the film during film formation can be exhibited. In addition, by using the alkoxysilane hydrolysate, the wettability of the film surface can be improved. It is preferable that the alkoxysilane hydrolysate is produced by condensation due to hydrolysis of an alkoxysilane compound, and it is more preferable that the alkoxysilane hydrolysate is produced by condensation due to hydrolysis of an alkoxysilane compound and a fluoroalkyl group-containing alkoxysilane compound. Examples of the alkoxysilane hydrolysate include an alkoxysilane hydrolysate described in paragraphs “0022” to “0027” of WO2015/190374A, the content of which is incorporated herein by reference. In a case where the composition according to the embodiment of the present invention includes the alkoxysilane hydrolysate, the total content of the silica particles and the alkoxysilane hydrolysate is preferably 0.1 mass % or higher, more preferably 1 mass % or higher, and still more preferably 2 mass % or higher with respect to the total solid content in the composition. The upper limit is preferably 99.99 mass % or lower, more preferably 99.95 mass % or lower, and still more preferably 99.9 mass % or lower.
<<Silicone-Based Surfactant>>
The composition according to the embodiment of the present invention includes a silicone-based surfactant. In the present specification, the silicone-based surfactant refers to a compound that includes a repeating unit having a siloxane bond in the main chain and refers to a compound having a hydrophobic portion and a hydrophilic portion in one molecule.
It is preferable that the silicone-based surfactant used in the present invention is a compound not having a fluorine atom. According to this aspect, the uniformity of the surface tension can be easily increased, and the effects of the present invention easily obtained more significantly.
Regarding the silicone-based surfactant used in the present invention, it is preferable that, in a case where 0.1 g of the silicone-based surfactant is dissolved in 100 g of propylene glycol monomethyl ether acetate to prepare a solution, a surface tension of the solution at 25° C. is 19.5 to 26.7 mN/m.
The kinetic viscosity of the silicone-based surfactant at 25° C. is preferably 20 to 3000 mm2/s. The lower limit of the kinetic viscosity is preferably 22 mm2/s or higher, more preferably 25 mm2/s or higher, and still more preferably 30 mm2/s or higher. The upper limit of the kinetic viscosity is preferably 2500 mm2/s or lower, more preferably 2000 mm2/s or lower, and still more preferably 1500 mm2/s or lower. In a case where the kinetic viscosity of the silicone-based surfactant is in the above-described range, higher coating properties can be easily obtained, and the occurrence of wave-like coating unevenness can be more effectively suppressed.
The weight-average molecular weight of the silicone-based surfactant is preferably 500 to 50000. The lower limit of the weight-average molecular weight is preferably 600 or higher, more preferably 700 or higher, and still more preferably 800 or higher. The upper limit of the weight-average molecular weight is preferably 40000 or lower, more preferably 30000 or lower, and still more preferably 20000 or lower.
It is preferable that the silicone-based surfactant is a modified silicone compound. Examples of the modified silicone compound include a compound having a structure in which an organic group is introduced into a side chain and/or a terminal of polysiloxane. Examples of the organic group include a group having a functional group selected from an amino group, an epoxy group, an alicyclic epoxy group, a carbinol group, a mercapto group, a carboxyl group, a fatty acid ester group, and a fatty acid amide group, and a group having a polyether chain. From the viewpoint that the effects of the present invention can be easily obtained more significantly, the organic group is preferably a group having a carbinol group or a group having a polyether chain.
Examples of the group having a carbinol group include a group represented by Formula (G-1).
-LG1-CH2OH (G-1)
In Formula (G-1), LG1 represents a single bond or a linking group. Examples of the linking group represented by LG1 include an alkylene group (preferably an alkylene group having 1 to 12 carbon atoms and more preferably an alkylene group having 1 to 6 carbon atoms), an arylene group (preferably an arylene group having 6 to 20 carbon atoms and more preferably an arylene group having 6 to 12 carbon atoms), —NH—, —SO—, —SO2—, —CO—, —O—, —COO—, —OCO—, —S—, and a group including a combination of two or more thereof.
The group having a carbinol group is preferably a group represented by Formula (G-2).
-LG2-O-LG3-CH2OH (G-2)
In Formula (G-2), LG2 and LG3 each independently represent a single bond or an alkylene group (preferably an alkylene group having 1 to 12 carbon atoms and more preferably an alkylene group having 1 to 6 carbon atoms), and preferably represents an alkylene group.
Examples of the group having a polyether chain include a group represented by Formula (G-11) and a group represented by Formula (G-12).
-LG11-(RG1O)n1RG2 (G-11)
-LG11-(ORG1)n1ORG2 (G-12)
In Formula (G-11) and Formula (G-12), LG11 represents a single bond or a linking group. Examples of the linking group represented by LG11 include an alkylene group (preferably an alkylene group having 1 to 12 carbon atoms and more preferably an alkylene group having 1 to 6 carbon atoms), an arylene group (preferably an arylene group having 6 to 20 carbon atoms and more preferably an arylene group having 6 to 12 carbon atoms), —NH—, —SO—, —SO2—, —CO—, —O—, —COO—, —OCO—, —S—, and a group including a combination of two or more thereof.
In Formula (G-11) and Formula (G-12), n1 represents a number of 2 or more and preferably 2 to 200.
In Formula (G-11) and Formula (G-12), RG1 represents an alkylene group. The number of carbon atoms in the alkylene group is preferably 1 to 10, more preferably 1 to 5, still more preferably 1 to 3, and still more preferably 2 or 3. The alkylene group represented by RG1 may be linear or branched, n1 alkylene groups represented by RG1 may be the same as or different from each other.
In Formula (G-11) and Formula (G-12), RG2 represents a hydrogen atom, an alkyl group, or an aryl group. The number of carbon atoms in the alkyl group represented by RG2 is preferably 1 to 10, more preferably 1 to 5, and still more preferably 1 to 3. The alkyl group may be linear or branched. The number of carbon atoms in the aryl group represented by RG2 is preferably 6 to 20 and more preferably 6 to 10.
It is preferable that the group having a polyether chain is a group represented by Formula (G-13) or a group represented by (Formula (G-14).
-LG12-(C2H4O)n2(C3H6O)n3RG3 (G-13)
-LG12-(OC2H4)n2(OC3H6)n3ORG3 (G-14)
In Formula (G-13) and Formula (G-14), LG12 represents a single bond or a linking group. Examples of the linking group represented by LG12 include an alkylene group (preferably an alkylene group having 1 to 12 carbon atoms and more preferably an alkylene group having 1 to 6 carbon atoms), an arylene group (preferably an arylene group having 6 to 20 carbon atoms and more preferably an arylene group having 6 to 12 carbon atoms), —NH—, —SO—, —SO2—, —CO—, —O—, —COO—, —OCO—, —S—, and a group including a combination of two or more thereof.
In Formula (G-13) and Formula (G-14), n2 and n3 each independently represent a number of 1 or more and preferably 1 to 100.
In Formula (G-13) and Formula (G-14), RG3 represents a hydrogen atom, an alkyl group, or an aryl group. The number of carbon atoms in the alkyl group represented by RG3 is preferably 1 to 10, more preferably 1 to 5, and still more preferably 1 to 3. The alkyl group may be linear or branched. The number of carbon atoms in the aryl group represented by RG3 is preferably 6 to 20 and more preferably 6 to 10.
It is preferable that the modified silicone compound is a compound represented by any one of Formulae (Si-1) to (Si-5).
In Formula (Si-1), R1 to R7 each independently represent an alkyl group or an aryl group.
X1 represents a group having a functional group selected from an amino group, an epoxy group, an alicyclic epoxy group, a carbinol group, a mercapto group, a carboxyl group, a fatty acid ester group, and a fatty acid amide group, or a group having a polyether chain.
m1 represents a number of 2 to 200.
The number of carbon atoms in the alkyl group represented by R1 to R7 is preferably 1 to 10, more preferably 1 to 5, still more preferably 1 to 3, and still more preferably 1. The alkyl group represented by R1 to R7 may be linear or branched and is preferably linear. The number of carbon atoms in the aryl group represented by R1 to R7 is preferably 6 to 20, more preferably 6 to 12, and still more preferably 6. R1 to R7 each independently represent preferably a methyl group or a phenyl group and more preferably a methyl group.
X1 represents preferably a group having a carbinol group or a group having a polyether chain and more preferably a group having a carbinol group. A preferable range of the group having a carbinol group or the group having a polyether chain is synonymous with the above-described range.
In Formula (Si-2), R11 to R16 each independently represent an alkyl group or an aryl group.
X11 and X12 each independently represent a group having a functional group selected from an amino group, an epoxy group, an alicyclic epoxy group, a carbinol group, a mercapto group, a carboxyl group, a fatty acid ester group, and a fatty acid amide group, or a group having a polyether chain.
m11 represents a number of 2 to 200.
R11 to R16 in Formula (Si-2) has the same definitions and the same preferable ranges as R1 to R7 in Formula (Si-1). X11 and X12 in Formula (Si-2) have the same definition and the same preferable range as X1 in Formula (Si-1).
In Formula (Si-3), R21 to R29 each independently represent an alkyl group or an aryl group.
X21 represents a group having a functional group selected from an amino group, an epoxy group, an alicyclic epoxy group, a carbinol group, a mercapto group, a carboxyl group, a fatty acid ester group, and a fatty acid amide group, or a group having a polyether chain.
m21 and m22 each independently represent an integer of 1 to 199, and in a case where m22 represents 2 or more, m22 x21's may be the same as or different from each other.
R21 to R29 in Formula (Si-3) has the same definitions and the same preferable ranges as R1 to R7 in Formula (Si-1). X21 in Formula (Si-3) have the same definition and the same preferable range as X1 in Formula (Si-1).
In Formula (Si-4), R31 to R38 each independently represent an alkyl group or an aryl group.
X31 and X32 each independently represent a group having a functional group selected from an amino group, an epoxy group, an alicyclic epoxy group, a carbinol group, a mercapto group, a carboxyl group, a fatty acid ester group, and a fatty acid amide group, or a group having a polyether chain.
m31 and m32 each independently represent an integer of 1 to 199, and in a case where m32 represents 2 or more, m32 x31's may be the same as or different from each other.
R31 to R38 in Formula (Si-4) has the same definitions and the same preferable ranges as R1 to R7 in Formula (Si-1). X31 and X32 in Formula (Si-4) have the same definition and the same preferable range as X1 in Formula (Si-1).
In Formula (Si-5), R41 to R47 each independently represent an alkyl group or an aryl group.
X41 and X43 each independently represent a group having a functional group selected from an amino group, an epoxy group, an alicyclic epoxy group, a carbinol group, a mercapto group, a carboxyl group, a fatty acid ester group, and a fatty acid amide group, or a group having a polyether chain.
m41 and m42 each independently represent an integer of 1 to 199, and in a case where m42 represents 2 or more, m42 x42's may be the same as or different from each other.
R41 to R47 in Formula (Si-5) has the same definitions and the same preferable ranges as R1 to R7 in Formula (Si-1). X41 to X43 in Formula (Si-4) have the same definition and the same preferable range as X1 in Formula (Si-1).
Specific examples of the silicone-based surfactant include compounds described below in Examples. In addition, Examples of a commercially available product of the silicone-based surfactant include: TORAY SILICONE DC3PA, TORAY SILICONE SH7PA, TORAY SILICONE DC11PA, TORAY SILICONE SH21PA, TORAY SILICONE SH28PA, TORAY SILICONE SH29PA, TORAY SILICONE SH30PA, and TORAY SILICONE SH8400 (all of which are manufactured by Dow Corning Corporation); Silwet L-77, L-7280, L-7001, L-7002, L-7200, L-7210, L-7220, L-7230, L7500, L-7600, L-7602, L-7604, L-7605, L-7622, L-7657, L-8500, and L-8610 (all of which are manufactured by Momentive Performance Materials Inc.); KP-341, KF-6001, and KF-6002 (all of which are manufactured by Shin-Etsu Chemical Co., Ltd.); and BYK307, BYK323, and BYK330 (all of which are manufactured by BYK-Chemie Japan K.K.).
The content of the silicone-based surfactant in the composition according to the embodiment of the present invention is preferably 0.01 to 0.3 mass %. From the viewpoint of easily suppressing the occurrence of wave-like coating unevenness more effectively, the lower limit is preferably 0.05 mass % or higher, more preferably 0.1 mass % or higher, and still more preferably 0.15 mass % or higher. From the viewpoint of further improving the coating properties of another composition for forming a film, the upper limit is preferably 0.28 mass % or lower, more preferably 0.25 mass % or lower, and still more preferably 0.2 mass % or lower. The content of the silicone-based surfactant in the composition according to the embodiment of the present invention is preferably 0.05 to 5.00 mass % with respect to the total solid content of the composition according to the embodiment of the present invention. From the viewpoint of easily suppressing the occurrence of wave-like coating unevenness more effectively, the lower limit is preferably 0.1 mass % or higher, more preferably 0.5 mass % or higher, and still more preferably 1.2 mass % or higher. From the viewpoint of further improving the coating properties of another composition for forming a film, the upper limit is preferably 4 mass % or lower and more preferably 3 mass % or lower. In addition, the content of the silicone-based surfactant is preferably 0.3 to 5.5 parts by mass with respect to 100 parts by mass of the silica particles. From the viewpoint of easily suppressing the occurrence of wave-like coating unevenness more effectively, the lower limit is preferably 0.5 parts by mass or more and more preferably 1.0 parts by mass or more. From the viewpoint of further improving the coating properties of another composition for forming a film, the upper limit is preferably 5.0 parts by mass or less and more preferably 4.0 parts by mass or less. The composition according to the embodiment of the present invention may include one silicone-based surfactant or two or more silicone-based surfactants. In a case where the composition according to the embodiment of the present invention includes two or more silicone-based surfactants, it is preferable that the total content of the two or more silicone-based surfactants is in the above-described range.
<<Other Surfactants>>
The composition according to the embodiment of the present invention may include surfactants (hereinafter, also referred to as “the other surfactants”) other than the silicone-based surfactant. As the other surfactant, any one of a nonionic surfactant, a cationic surfactant, or an anionic surfactant may be used. Examples of the nonionic surfactant include a fluorine-based surfactant.
In a case where the surfactant is a polymer compound, the weight-average molecular weight of the surfactant is preferably 1500 or higher, more preferably 2500 or higher, still more preferably 5000 or higher, and still more preferably 10000 or higher. The upper limit is preferably 50000 or lower, more preferably 25000 or lower, and still more preferably 17500 or lower.
The fluorine-based surfactant is preferably a polymer surfactant having a polyethylene main chain. In particular, a polymer surfactant having a poly(meth)acrylate structure is preferable. In particular, in the present invention, a copolymer including a (meth)acrylate constitutional unit having the polyoxyalkylene structure and a fluorinated alkylacrylate constitutional unit is preferable.
In addition, as the fluorine-based surfactant, a compound having a fluoroalkyl group or a fluoroalkylene group (preferably having 1 to 24 carbon atoms and more preferably 2 to 12 carbon atoms) at any site can be suitably used. Preferably, a polymer compound having the fluoroalkyl group or the fluoroalkylene group at a side chain can be used. It is preferable that the fluorine-based surfactant further includes the polyoxyalkylene structure, and it is more preferable that the fluorine-based surfactant includes the polyoxyalkylene structure at a side chain. Examples of the compound having the fluoroalkyl group or the fluoroalkylene group include a compound described in paragraphs “0034” to “0040” of WO2015/190374A, the content of which is incorporated herein by reference.
Examples of the fluorine-based surfactant include MEGAFACE F171, F172, F173, F176, F177, F141, F142, F143, F144, R30, F437, F479, F482, F554, F559, F780, and F781F (all of which are manufactured by DIC Corporation); FLUORAD FC430, FC431, and FC171 (all of which are manufactured by Sumitomo 3M Ltd.); SURFLON S-382, S-141, S-145, SC-101, SC-103, SC-104, SC-105, SC1068, SC-381, SC-383, S-393, and KH-40 (all of which are manufactured by AGC Inc.), F-TOP EF301, EF303, EF351, EF352 (all of which are manufactured by Gemco Inc.); and PF636, PF656, PF6320, PF6520, and PF7002 (all of which manufactured by OMNOVA Solutions Inc.).
In addition, as the fluorine-based surfactant, a block polymer can also be used. Examples of the block polymer include a compound described in JP2011-089090A. As the fluorine-based surfactant, a fluorine-containing polymer compound can be preferably used, the fluorine-containing polymer compound including: a repeating unit derived from a (meth)acrylate compound having a fluorine atom; and a repeating unit derived from a (meth)acrylate compound having 2 or more (preferably 5 or more) alkyleneoxy groups (preferably an ethyleneoxy group and a propyleneoxy group). For example, the following compound can also be used as the fluorine-based surfactant used in the present invention.
The weight-average molecular weight of the compound is preferably 3000 to 50000 and, for example, 14000. In the compound, “%” representing the proportion of a repeating unit is mol %.
Examples of the nonionic surfactant, the anionic surfactant, and the cationic surfactant other than the fluorine-based surfactant include a surfactant described in paragraphs “0042” to “0045” of WO2015/190374A, the content of which is incorporated herein by reference.
As the other surfactant, a surfactant having a polyoxyalkylene structure can also be used. The polyoxyalkylene structure refers to a structure in which an alkylene group and a divalent oxygen atom are present adjacent to each other, and specific examples thereof include an ethylene oxide (EO) structure and a propylene oxide (PO) structure. The polyoxyalkylene structure may constitute a graft chain of an acrylic polymer.
The content of the other surfactants is preferably 5.0 parts by mass or less, more preferably 3.0 parts by mass or less, and still more preferably 1.0 part by mass or less with respect to 100 parts by mass of the total content of the silicone-based surfactant and the other surfactants. In addition, the content of the other surfactants in the composition according to the embodiment of the present invention is preferably 0.1 mass % or lower, more preferably 0.05 mass % or lower, and still more preferably 0.02 mass % or lower. In addition, the content of the other surfactants is preferably 1.0 mass % or lower, more preferably 0.5 mass % or lower, and still more preferably 0.2 mass % or lower with respect to the total solid content of the composition according to the embodiment of the present invention. In addition, it is also preferable that the composition according to the embodiment of the present invention does not substantially include the other surfactants. A case where the composition according to the embodiment of the present invention does not substantially include the other surfactants represents that the content of the other surfactants is 0.01 mass % or lower, preferably 0.005 mass % or lower, and more preferably 0 mass % with respect to the total solid content of the composition.
<<Solvent>>
The composition according to the embodiment of the present invention includes a solvent. Examples of the solvent include an organic solvent and water, and it is preferable that the solvent includes at least an organic solvent. Examples of the organic solvent include an aliphatic hydrocarbon solvent, a halogenated hydrocarbon solvent, an alcohol solvent, an ether solvent, an ester solvent, a ketone solvent, a nitrile solvent, an amide solvent, a sulfoxide solvent, and an aromatic solvent.
Examples of the aliphatic hydrocarbon solvent include hexane, cyclohexane, methylcyclohexane, pentane, cyclopentane, heptane, and octane.
Examples of the halogenated hydrocarbon solvent include methylene chloride, chloroform, dichloromethane, ethane dichloride, carbon tetrachloride, trichloroethylene, tetrachloroethylene, epichlorohydrin, monochlorobenzene, orthodichlorobenzene, allylchloride, methyl monochloroacetate, ethyl monochloroacetate, monochloroacetate, trichloroacetate, methyl bromide, and tri(tetra)chloroethylene.
Examples of the alcohol solvent include methanol, ethanol, 1-propanol, 2-propanol, 2-butanol, ethylene glycol, propylene glycol, glycerin, 1,6-hexanediol, cyclohexanediol, sorbitol, xylitol, 2-methyl-2,4-pentanediol, 3-methoxy-1-butanol, 1,3-butanediol, and 1,4-butanediol.
Examples of the ether solvent include dimethyl ether, diethyl ether, diisopropyl ether, dibutyl ether, t-butyl methyl ether, cyclohexyl methyl ether, anisole, tetrahydrofuran, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, diethylene glycol dibutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, dipropylene glycol methyl-n-propyl ether, triethylene glycol monomethyl ether, triethylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tripropylene glycol monobutyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol monomethyl ether, and polyethylene glycol dimethyl ether.
Examples of the ester solvent include propylene carbonate, dipropylene, 1,4-butanediol diacetate, 1,3-butylene glycol diacetate, 1,6-hexanediol diacetate, cyclohexanol acetate, dipropylene glycol methyl ether acetate, methyl acetate, ethyl acetate, isopropyl acetate, n-propyl acetate, butyl acetate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, 3-methoxy butyl acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, and triacetin.
Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, and 2-heptanone.
Examples of the nitrile solvent include acetonitrile.
Examples of the amide solvent include N,N-dimethylformamide, 1-methyl-2-pyrrolidone, 2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, formamide, N-methyl formamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropaneamide, hexamethylphosphoric amide, 3-methoxy-N,N-dimethylpropanamide, and 3-butoxy-N,N-dimethylpropanamide.
Examples of the sulfoxide solvent include dimethyl sulfoxide.
Examples of the aromatic solvent include benzene and toluene.
The content of the solvent in the composition according to the embodiment of the present invention is preferably 70 to 99 mass %. The upper limit is preferably 93 mass % or lower, more preferably 92 mass % or lower, and still more preferably 90 mass % or lower. The lower limit is preferably 75 mass % or higher, more preferably 80 mass % or higher, and still more preferably 85 mass % or higher.
In the present invention, it is preferable that the solvent includes the solvent A1 having a boiling point of 190° C. to 280° C. The boiling point of the solvent in the present specification refers to a value at 1 atm (0.1 MPa).
The boiling point of the solvent A1 is preferably 200° C. or higher, more preferably 210° C. or higher, and still more preferably 220° C. or higher. In addition, the boiling point of the solvent A1 is preferably 270° C. or lower and more preferably 265° C. or lower.
The viscosity of the solvent A1 is preferably 10 mPa·s or lower, more preferably 7 mPa·s or lower, and still more preferably 4 mPa·s or lower. From the viewpoint of coating properties, the lower limit of the viscosity of the solvent A1 is preferably 1.0 mPa·s or higher, more preferably 1.4 mPa·s or higher, and still more preferably 1.8 mPa·s or higher.
The molecular weight of the solvent A1 is preferably 100 or higher, more preferably 130 or higher, still more preferably 140 or higher, and still more preferably 150 or higher. From the viewpoint of coating properties, the upper limit is preferably 300 or lower, more preferably 290 or lower, still more preferably 280 or lower, and still more preferably 270 or lower.
A solubility parameter of the solvent A1 is preferably 8.5 to 13.3 (cal/cm3)0.5. The upper limit is preferably 12.5 (cal/cm3)0.5 or lower, more preferably 11.5 (cal/cm3)0.5 or lower, and still more preferably 10.5 (cal/cm3)0.5 or lower. The lower limit is preferably 8.7 (cal/cm3)0.5 or higher, more preferably 8.9 (cal/cm3)0.5 or higher, and still more preferably 9.1 (cal/cm3)0.5 or higher. In a case where the solubility parameter of the solvent A1 is in the above-described range, high affinity to silica particles A can be obtained, and excellent coating properties can be easily obtained. 1 (cal/cm3)0.5 is 2.0455 MPa0.5. In addition, the solubility parameter of the solvent is a value calculated using HSPiP.
In the present specification, as the solubility parameter of the solvent, a Hansen solubility parameter is used. Specifically, a value calculated using Hansen solubility parameter software “HSPiP 5.0.09” is used.
It is preferable that the solvent A1 is a non-protonic solvent. By using the non-protonic solvent as the solvent A1, aggregation of the silica particles A during film formation can be more effectively suppressed.
As the solvent A1, an ether solvent, or an ester solvent is preferable, and an ester solvent is more preferable. In addition, it is preferable that the ester solvent used as the solvent A1 is a compound not having a hydroxyl group or a terminal alkoxy group. By using the ester solvent not having the functional group, the effect of the present invention can be easily obtained more significantly.
From the viewpoint that high affinity to the silica particles A can be obtained and excellent coating properties can be easily obtained, it is preferable that the solvent A1 is at least one selected from alkylenediol diacetate or cyclic carbonate. Examples of the alkylenediol diacetate include propylene glycol diacetate, 1,4-butanediol diacetate, 1,3-butylene glycol diacetate, and 1,6-hexanediol diacetate. Examples of the cyclic carbonate include propylene carbonate and ethylene carbonate.
Specific examples of the solvent A1 include propylene carbonate (boiling point: 240° C.), ethylene carbonate (boiling point: 260° C.), propylene glycol diacetate (boiling point: 190° C.), dipropylene glycol methyl-n-propyl ether (boiling point: 203° C.), dipropylene glycol methyl ether acetate (boiling point: 213° C.), 1,4-butanediol diacetate (boiling point: 232° C.), 1,3-butylene glycol diacetate (boiling point: 232° C.), 1,6-hexanediol diacetate (boiling point: 260° C.), diethylene glycol monoethyl ether acetate (boiling point: 217° C.), diethylene glycol monobutyl ether acetate (boiling point: 247° C.), triacetin (boiling point: 260° C.), dipropylene glycol monomethyl ether (boiling point: 190° C.), diethylene glycol monoethyl ether (boiling point: 202° C.), dipropylene glycol monopropyl ether (boiling point: 212° C.), dipropylene glycol monobutyl ether (boiling point: 229° C.), tripropylene glycol monomethyl ether (boiling point: 242° C.), and tripropylene glycol monobutyl ether (boiling point: 274° C.).
In the solvent used in the composition according to the embodiment of the present invention, the content of the solvent A1 is preferably 3 mass % or higher, more preferably 4 mass % or higher, and still more preferably 5 mass % or higher. According to the aspect, the effect of the present invention can be easily obtained more significantly. The upper limit is preferably 20 mass % or lower, more preferably 15 mass % or lower, and still more preferably 12 mass % or lower. According to this aspect, a film having an excellent surface shape can be easily obtained. As the solvent A1, one kind may be used, or two or more kinds may be used in combination. In a case where the composition according to the embodiment of the present invention includes two or more solvents A1, it is preferable that the total content of the two or more solvents A1 is in the above-described range.
It is preferable that the solvent used in the composition according to the embodiment of the present invention further includes a solvent A2 having a boiling point of 110° C. or higher and lower than 190° C. According to this aspect, the drying properties of the composition are appropriately improved such that the occurrence of wave-like coating unevenness can be effectively suppressed, and a film having an excellent surface shape can be easily formed.
The boiling point of the solvent A2 is preferably 115° C. or higher, more preferably 120° C. or higher, and still more preferably 130° C. or higher. In addition, the boiling point of the solvent A2 is preferably 170° C. or lower and more preferably 150° C. or lower. In a case where the boiling point of the solvent A2 is in the above-described range, the above-described effect can be easily obtained more significantly.
From the viewpoint that the above-described effect can be easily obtained more significantly, the molecular weight of the solvent A2 is preferably 100 or higher, more preferably 130 or higher, still more preferably 140 or higher, and still more preferably 150 or higher. From the viewpoint of coating properties, the upper limit is preferably 300 or lower, more preferably 290 or lower, still more preferably 280 or lower, and still more preferably 270 or lower.
A solubility parameter of the solvent A2 is preferably 9.0 to 11.4 (cal/cm3)0.5. The upper limit is preferably 11.0 (cal/cm3)0.5 or lower, more preferably 10.6 (cal/cm3)0.5 or lower, and still more preferably 10.2 (cal/cm3)0.5 or lower. The lower limit is preferably 9.2 (cal/cm3)0.5 or higher, more preferably 9.4 (cal/cm3)0.5 or higher, and still more preferably 9.6 (cal/cm3)0.5 or higher. In a case where the solubility parameter of the solvent A2 is in the above-described range, high affinity to silica particles A can be obtained, and excellent coating properties can be easily obtained. In addition, an absolute value of a difference between the solubility parameter of the solvent A1 and the solubility parameter of the solvent A2 is preferably 0.01 to 1.1 (cal/cm3)0.5. The upper limit is preferably 0.9 (cal/cm3)0.5 or lower, more preferably 0.7 (cal/cm3)0.5 or lower, and still more preferably 0.5 (cal/cm3)0.5 or lower. The lower limit is preferably 0.03 (cal/cm3)0.5 or higher, more preferably 0.05 (cal/cm3)0.5 or higher, and still more preferably 0.08 (cal/cm3)0.5 or higher.
It is preferable that the solvent A2 is at least one selected from an ether solvent or an ester solvent, it is more preferable that the solvent A2 includes at least an ester solvent, and it is still more preferable that the solvent A2 includes an ether solvent and an ester solvent. Specific examples of the solvent A2 include cyclohexanol acetate (boiling point 173° C.), dipropylene glycol dimethyl ether (boiling point: 175° C.), butyl acetate (boiling point: 126° C.), ethylene glycol monomethyl ether acetate (boiling point: 145° C.), propylene glycol monomethyl ether acetate (boiling point: 146° C.), 3-methoxy butyl acetate (boiling point: 171° C.), propylene glycol monomethyl ether (boiling point: 120° C.), 3-methoxybutanol (boiling point: 161° C.), propylene glycol monopropyl ether (boiling point: 150° C.), propylene glycol monobutyl ether (boiling point: 170° C.), and ethylene glycol monobutyl ether acetate (boiling point: 188° C.). From the viewpoint of obtaining high affinity to the silica particles A such that excellent coating properties can be easily obtained, it is preferable that the solvent A2 includes at least propylene glycol monomethyl ether acetate.
In a case where the solvent used in the composition according to the embodiment of the present invention includes the solvent A2, the content of the solvent A2 is preferably 500 to 5000 parts by mass with respect to 100 parts by mass of the solvent A1. The upper limit is preferably 4500 parts by mass or less, more preferably 4000 parts by mass or less, and still more preferably 3500 parts by mass or less. The lower limit is preferably 600 parts by mass or more, more preferably 700 parts by mass or more, and still more preferably 750 parts by mass or more. In addition, the content of the solvent A2 is preferably 50 mass % or higher, more preferably 60 mass % or higher, and still more preferably 70 mass % or higher with respect to the total content of the solvent. The upper limit is preferably 95 mass % or lower, more preferably 90 mass % or lower, and still more preferably 85 mass % or lower. In a case where the content of the solvent A2 is in the above-described range, the effect of the present invention can be easily obtained more significantly. As the solvent A2, one kind may be used, or two or more kinds may be used in combination. In a case where the composition according to the embodiment of the present invention includes two or more solvents A2, it is preferable that the total content of the two or more solvents A2 is in the above-described range.
In addition, in the solvent used in the composition according to the embodiment of the present invention, the total content of the solvent A1 and the solvent A2 is preferably 62 mass % or higher, more preferably 72 mass % or higher, and still more preferably 82 mass % or higher. The upper limit may be 100 mass %, 96 mass % or lower, or 92 mass % or lower.
It is preferable that the solvent used in the composition according to the embodiment of the present invention further includes at least one solvent A3 selected from methanol, ethanol, or 2-propyl alcohol. According to this aspect, high affinity to the silica particles A can be obtained, and excellent coating properties can be easily obtained. In a case where the solvent used in the composition according to the embodiment of the present invention includes the solvent A3, the content of the solvent A3 is preferably 0.1 to 10 mass % with respect to the total content of the solvent. The upper limit is preferably 8 mass % or lower, more preferably 6 mass % or lower, and still more preferably 4 mass % or lower. The lower limit is preferably 0.3 mass % or higher, more preferably 0.5 mass % or higher, and still more preferably 1 mass % or higher. In a case where the content of the solvent A3 is in the above-described range, the above-described effect can be easily obtained more significantly. As the solvent A3, one kind may be used, or two or more kinds may be used in combination. In a case where the composition according to the embodiment of the present invention includes two or more solvents A3, it is preferable that the total content of the two or more solvents A3 is in the above-described range.
It is also preferable that the solvent used in the composition according to the embodiment of the present invention further includes water. According to this aspect, high affinity to the silica particles A can be obtained, and excellent coating properties can be easily obtained. In a case where the solvent used in the composition according to the embodiment of the present invention includes water, the content of water is preferably 0.1 to 5 mass % with respect to the total content of the solvent. The upper limit is preferably 4 mass % or lower, more preferably 2.5 mass % or lower, and still more preferably 1.5 mass % or lower. The lower limit is preferably 0.3 mass % or higher, more preferably 0.5 mass % or higher, and still more preferably 1.0 mass % or higher. In a case where the content of water is in the above-described range, the above-described effect can be easily obtained more significantly.
It is also preferable that the solvent used in the composition according to the embodiment of the present invention includes the solvent A3 and water. High affinity to the silica particles A can be obtained, and excellent coating properties can be easily obtained. In a case where the solvent used in the composition according to the embodiment of the present invention includes the solvent A3 and water, the total content of the solvent A3 and water is preferably 0.2 to 15 mass % with respect to the total content of the solvent. The upper limit is preferably 12 mass % or lower, more preferably 9 mass % or lower, and still more preferably 6 mass % or lower. The lower limit is preferably 0.4 mass % or higher, more preferably 0.7 mass % or higher, and still more preferably 1.5 mass % or higher. In a case where the total content of the solvent A3 and water is in the above-described range, the above-described effect can be easily obtained more significantly.
The solvent used in the composition according to the embodiment of the present invention may include a solvent A4 having a boiling point of higher than 280° C. According to this aspect, the drying properties of the composition are appropriately improved such that the occurrence of wave-like coating unevenness can be effectively suppressed, and a film having an excellent surface shape can be easily formed. The upper limit of the boiling point of the solvent A4 is preferably 400° C. or lower, more preferably 380° C. or lower, and still more preferably 350° C. or lower. It is preferable that the solvent A4 is at least one selected from an ether solvent or an ester solvent. Specific examples of the solvent A4 include polyethylene glycol monomethyl ether. In a case where the solvent used in the composition according to the embodiment of the present invention includes the solvent A4, the content of the solvent A4 is preferably 0.5 to 15 mass % with respect to the total content of the solvent. The upper limit is preferably 10 mass % or lower, more preferably 8 mass % or lower, and still more preferably 6 mass % or lower. The lower limit is preferably 1 mass % or higher, more preferably 1.5 mass % or higher, and still more preferably 2 mass % or higher. In addition, it is also preferable that the solvent used in the composition according to the embodiment of the present invention does not substantially include the solvent A4. A case where the solvent does not substantially include the solvent A4 represents that the content of the solvent A4 is 0.1 mass % or lower, preferably 0.05 mass % or lower, more preferably 0.01 mass % or lower, and still more preferably 0 mass % with respect to the total content of the solvent.
The solvent used in the composition according to the embodiment of the present invention may include solvents (other solvents) other than the solvent A1, the solvent A2, the solvent A3, the solvent A4, and water but preferably does not substantially include the other solvents. A case where the solvent does not substantially include the other solvents represents that the content of the other solvents is 0.1 mass % or lower, preferably 0.05 mass % or lower, more preferably 0.01 mass % or lower, and still more preferably 0 mass % with respect to the total content of the solvent.
In the solvent used in the composition according to the embodiment of the present invention, the content of a compound having a molecular weight (in the case of a polymer weight-average molecular weight) of higher than 300 is preferably 10 mass % or lower, more preferably 8 mass % or lower, still more preferably 5 mass % or lower, still more preferably 3 mass % or lower, and still more preferably 1 mass % or lower. According to this aspect, higher coating properties can be easily obtained, and a film having an excellent surface shape can be easily obtained.
In the solvent used in the composition according to the embodiment of the present invention, the content of a compound having a viscosity of higher than 10 mPa·s at 25° C. is preferably 10 mass % or lower, more preferably 8 mass % or lower, still more preferably 5 mass % or lower, still more preferably 3 mass % or lower, and still more preferably 1 mass % or lower. According to this aspect, higher coating properties can be easily obtained, and a film having an excellent surface shape can be easily obtained.
<<Dispersant>>
The composition according to the embodiment of the present invention may include a dispersant. Examples of the dispersant include: a polymer dispersant (for example, polyamideamine or a salt thereof, a polycarboxylic acid or a salt thereof, a high-molecular-weight unsaturated acid ester, a modified polyurethane, a modified polyester, a modified poly(meth)acrylate, a (meth)acrylic copolymer, or a naphthalene sulfonic acid formalin condensate), polyoxyethylene, alkyl phosphoric acid ester, polyoxyethylene alkyl amine, and alkanol amine. In terms of a structure, the polymer dispersant can be further classified into a linear polymer, a terminal-modified polymer, a graft polymer, and a block polymer. The polymer dispersant adsorbs on surfaces of particles and functions to prevent reaggregation. Therefore, for example, a terminal-modified polymer a graft polymer, or a block polymer having an anchor site to particle surfaces can be used as a preferable structure. As the dispersant, a commercially available product can also be used. Examples of the commercially available product include products described in paragraph “0050” of WO2016/190374A, the content of which is incorporated herein by reference.
The content of the dispersant is preferably 1 to 100 parts by mass, more preferably 3 to 100 parts by mass, and still more preferably 5 to 80 parts by mass with respect to 100 parts by mass of the silica particles. In addition, the content of the dispersant is preferably 1 to 30 mass % with respect to the total solid content of the composition. The composition may include one dispersant or two or more dispersants. In a case where the composition according to the embodiment of the present invention includes two or more dispersants, it is preferable that the total content of the two or more dispersants is in the above-described range.
<<Polymerizable Compounds>>
The composition according to the embodiment of the present invention includes a polymerizable compound. As the polymerizable compound, a well-known compound which is crosslinkable by a radical, an acid, or heat can be used. In the present invention, it is preferable that the polymerizable compound is a radically polymerizable compound. It is preferable that the radically polymerizable compound is a compound having an ethylenically unsaturated bond group.
The polymerizable compound may be in any chemical form of a monomer, a prepolymer, an oligomer, or the like and is preferably a monomer. The molecular weight of the polymerizable compound is preferably 100 to 3000. The upper limit is more preferably 2000 or lower and still more preferably 1500 or lower. The lower limit is more preferably 150 or higher and still more preferably 250 or higher.
As the polymerizable compound, a compound having two or more ethylenically unsaturated bond groups is preferable, and a compound having three or more ethylenically unsaturated bond groups is more preferable. The upper limit of the number of the ethylenically unsaturated bond groups is, for example, preferably 15 or less and more preferably 6 or less. Examples of the ethylenically unsaturated bond group include a vinyl group, a styrene group, a (meth)allyl group, and a (meth)acryloyl group. Among these, a (meth)acryloyl group is preferable. The polymerizable compound is preferably a (meth)acrylate compound having 3 to 15 functional groups and more preferably a (meth)acrylate compound having 3 to 6 functional groups. Specific examples of the polymerizable compound include a compound described in paragraphs “0059” to “0079” of WO2016/190374A.
As the polymerizable compound, dipentaerythritol triacrylate (KAYARAD D-330 as a commercially available product; manufactured by Nippon Kayaku Co., Ltd.), dipentaerythritol tetraacrylate (KAYARAD D-320 as a commercially available product; manufactured by Nippon Kayaku Co., Ltd.), dipentaerythritol penta(meth)acrylate (KAYARAD D-310 as a commercially available product; manufactured by Nippon Kayaku Co., Ltd.), dipentaerythritol hexa(meth)acrylate (KAYARAD DPHA as a commercially available product; manufactured by Nippon Kayaku Co., Ltd., NK ESTER A-DPH-12E as a commercially available product; manufactured by Shin-Nakamura Chemical Co., Ltd.), a compound (for example, SR454 or SR-499; commercially available from Sartomer) having a structure in which (meth)acryloyl groups of these compounds are bonded through an ethylene glycol and/or a propylene glycol residue, diglycerin ethylene oxide (EO)-modified (meth)acrylate (as a commercially available product, M-460 manufactured by Toagosei Co., Ltd.), pentaerythritol tetraacrylate (NK ESTER A-TMMT manufactured by Shin-Nakamura Chemical Co., Ltd.), 1,6-hexanediol diacrylate (KAYARAD HDDA manufactured by Nippon Kayaku Co., Ltd.), RP-1040 (manufactured by Nippon Kayaku Co., Ltd.), ARONIX TO-2349 (manufactured by Toagosei Co., Ltd.), NK OLIGO UA-7200 (manufactured by Shin-Nakamura Chemical Co., Ltd.), 8UH-1006 or 8UH-1012 (manufactured by Taisei Fine Chemical Co., Ltd.), or LIGHT ACRYLATE POB-A0 (manufactured by Kyoeisha Chemical Co., Ltd.) can be used. In addition, as the polymerizable compound, for example, a compound having the following structure can also be used.
In addition, as the polymerizable compound, a trifunctional (meth)acrylate compound such as trimethylolpropane tri(meth)acrylate, trimethylolpropane propyleneoxide-modified tri(meth)acrylate, trimethylolpropane ethyleneoxide-modified tri(meth)acrylate, isocyanuric acid ethyleneoxide-modified tri(meth)acrylate, or pentaerythritol tri(meth)acrylate can also be used. Examples of a commercially available product of the trifunctional (meth)acrylate compound include ARONIX M-309, M-310, M-321, M-350, M-360, M-313, M-315, M-306, M-305, M-303, M-452, and M-450 (all of which are manufactured by Toagosei Co., Ltd.), NK ESTER A9300, A-GLY-9E, A-GLY-20E, A-TMM-3, A-TMM-3L, A-TMM-3LM-N, A-TMPT, and TMPT (manufactured by Shin-Nakamura Chemical Co., Ltd.), KAYARAD GPO-303, TMPTA, THE-330, TPA-330, and PET-30 (manufactured by Nippon Kayaku Co., Ltd.).
As the polymerizable compound, a compound having an acid group can also be used. By using the polymerizable compound having an acid group, a non-exposed portion of the polymerizable compound is likely to be removed during development, and the occurrence of development residue can be suppressed. Examples of the acid group include a carboxyl group, a sulfo group, and a phosphate group. Among these, a carboxyl group is preferable. Examples of a commercially available product of the polymerizable compound having an acid group include ARONIX M-510, ARONIX M-520, and ARONIX TO-2349 (manufactured by Toagosei Co., Ltd.). The acid value of the polymerizable compound having an acid group is preferably 0.1 to 40 mgKOH/g and more preferably 5 to 30 mgKOH/g. In a case where the acid value of the polymerizable compound is 0.1 mgKOH/g or higher, solubility in the developer is excellent. In a case where the acid value of the polymerizable compound is 40 mgKOH/g or lower, there are advantageous effects in manufacturing and handleability.
In addition, as the polymerizable compound, a compound having a caprolactone structure can also be used. As the polymerizable compound having a caprolactone structure, for example, KAYARAD DPCA series (manufactured by manufactured by Nippon Kayaku Co., Ltd.) is commercially available, and examples thereof include DPCA-20, DPCA-30, DPCA-60, and DPCA-120.
As the polymerizable compound, a polymerizable compound having an alkyleneoxy group may also be used. As the polymerizable compound having an alkyleneoxy group, a polymerizable compound having an ethyleneoxy group and/or a propyleneoxy group is preferable, a polymerizable compound having an ethyleneoxy group is more preferable, and a trifunctional to hexafunctional (meth)acrylate compound having 4 to 20 ethyleneoxy groups is still more preferable. Examples of a commercially available product of the polymerizable compound having an alkyleneoxy group include SR-494 (manufactured by Sartomer) which is a tetrafunctional (meth)acrylate having four ethyleneoxy groups, and KAYARAD TPA-330 which is a trifunctional (meth)acrylate having three isobutyleneoxy groups.
As the polymerizable compound, a polymerizable compound having a fluorene skeleton can also be used. Examples of a commercially available product of the polymerizable compound having a fluorene skeleton include OGSOL EA-0200 and EA-0300 (manufactured by Osaka Gas Chemicals Co., Ltd., a (meth)acrylate monomer having a fluorene skeleton).
In addition, it is preferable that a compound substantially not including an environmentally regulated material such as toluene is also used as the polymerizable compound. Examples of a commercially available product of the compound include KAYARAD DPHA LT and KAYARAD DPEA-12 LT (manufactured by Nippon Kayaku Co., Ltd.).
In a case where the composition according to the embodiment of the present invention includes a polymerizable compound, the content of the polymerizable compound in the composition according to the embodiment of the present invention is preferably 0.1 mass % or higher, more preferably 0.2 mass % or higher, still more preferably 0.5 mass % or higher. The upper limit is preferably 10 mass % or lower, more preferably 5 mass % or lower, and still more preferably 3 mass % or lower. The content of the polymerizable compound is preferably 1 mass % or higher, more preferably 2 mass % or higher, and still more preferably 5 mass % or higher with respect to the total solid content of the composition according to the embodiment of the present invention. The upper limit is preferably 30 mass % or lower, more preferably 25 mass % or lower, and still more preferably 20 mass % or lower. The composition according to the embodiment of the present invention may include one polymerizable compound or two or more polymerizable compounds. In a case where the composition according to the embodiment of the present invention includes two or more polymerizable compounds, it is preferable that the total content of the two or more polymerizable compounds is in the above-described range.
In addition, it is also preferable that the composition according to the embodiment of the present invention does not substantially include a polymerizable compound. In a case where the composition according to the embodiment of the present invention does not substantially include a polymerizable compound, a film having a lower refractive index can be easily formed. Further, a film having a low haze can be easily formed. A case where the composition according to the embodiment of the present invention does not substantially include the polymerizable compound represents that the content of the polymerizable compound is 0.05 mass % or lower, preferably 0.01 mass % or lower, and more preferably 0 mass % with respect to the total solid content of the composition.
<<Photopolymerization Initiator>>
In a case where the composition according to the embodiment of the present invention includes a polymerizable compound, it is preferable that the composition further includes a photopolymerization initiator. In a case where the composition according to the embodiment of the present invention includes a polymerizable compound and a photopolymerization initiator, the composition according to the embodiment of the present invention can be preferably used as a composition for forming a pattern using a photolithography method.
The photopolymerization initiator is not particularly limited as long as it has an ability to initiate the polymerization of the polymerizable compound, and can be selected from well-known photopolymerization initiators. In a case where the radically polymerizable compound is used as the polymerizable compound, it is preferable that the photoradical polymerization initiator is used as the photopolymerization initiator. Examples of the photoradical polymerization initiator include a trihalomethyltriazine compound, a benzyldimethylketal compound, an α-hydroxyketone compound, an α-aminoketone compound, an acylphosphine compound, a phosphine oxide compound, a metallocene compound, an oxime compound, a triarylimidazole dimer, an onium compound, a benzothiazole compound, a benzophenone compound, an acetophenone compound, a cyclopentadiene-benzene-iron complex, a halomethyl oxadiazole compound, and a coumarin compound. Among these, an oxime compound, an α-hydroxyketone compound, an α-aminoketone compound, or an acylphosphine compound is preferable, an oxime compound or an α-aminoketone compound is more preferable, and an oxime compound is still more preferable. Examples of the photopolymerization initiator include a compound described in paragraphs “0099” to “0125” of JP2015-166449A, the content of which is incorporated herein by reference.
Examples of the oxime compound include a compound described in JP2001-233842A, a compound described in J. C. S. Perkin II (1979, pp. 1653 to 1660), a compound described in J. C. S. Perkin II (1979, pp. 156 to 162), a compound described in Journal of Photopolymer Science and Technology (1995, pp. 202 to 232), a compound described in JP2000-066385A, a compound described in JP2000-080068A, a compound described in JP2004-534797A, a compound described in JP2006-342166A, a compound described in JP2017-019766A, a compound described in JP6065596B, a compound described in WO2015/152153A, a compound described in WO2017/051680A, a compound described in JP2017-198865A, a compound described in paragraphs “0025” to “0038” of WO2017/164127A, a compound described in WO2013/167515A. Specific examples of the oxime compound include 3-benzoyloxyiminobutane-2-one, 3-acetoxyiminobutane-2-one, 3-propionyloxyiminobutane-2-one, 2-acetoxyiminopentane-3-one, 2-acetoxyimino-1-phenylpropane-1-one, 2-benzoyloxyimino-1-phenylpropane-1-one, 3-(4-toluene sulfonyloxy)iminobutane-2-one, and 2-ethoxycarbonyloxyimino-1-phenylpropane-1-one. Examples of a commercially available product of the oxime compound include IRGACURE-OXE01, IRGACURE-OXE02, IRGACURE-OXE03, or IRGACURE-OXE04 (all of which are manufactured by BASF SE), TR-PBG-304 (manufactured by Changzhou Tronly New Electronic Materials Co., Ltd.), and ADEKA OPTOMER N-1919 (manufactured by Adeka Corporation, a photopolymerization initiator 2 described in JP2012-014052A). As the oxime compound, a compound having no colorability or a compound having high transparency that is not likely to be discolored can also be preferably used. Examples of a commercially available product of the oxime compound include ADEKA ARKLS NCI-730, NCI-831, and NCI-930 (all of which are manufactured by Adeka Corporation).
In the present invention, an oxime compound having a fluorene ring can also be used as the photopolymerization initiator. Specific examples of the oxime compound having a fluorene ring include a compound described in JP2014-137466A. The content of this specification is incorporated herein by reference.
In the present invention, an oxime compound having a fluorine atom can also be used as the photopolymerization initiator. Specific examples of the oxime compound having a fluorine atom include a compound described in JP2010-262028A, Compound 24 and 36 to 40 described in JP2014-500852A, and Compound (C-3) described in JP2013-164471A.
In the present invention, as the photopolymerization initiator, an oxime compound having a nitro group can be used. It is preferable that the oxime compound having a nitro group is a dimer. Specific examples of the oxime compound having a nitro group include a compound described in paragraphs “0031” to “0047” of JP2013-114249A and paragraphs “0008” to “0012” and “0070” to “0079” of JP2014-137466A, a compound described in paragraphs “0007” to 0025” of JP4223071B, and ADEKA ARKLS NCI-831 (manufactured by Adeka Corporation).
In the present invention, as the photopolymerization initiator, an oxime compound having a benzofuran skeleton can also be used. Specific examples include OE-01 to OE-75 described in WO2015/036910A.
The oxime compound is preferably a compound having a maximal absorption wavelength in a wavelength range of 350 to 500 nm and more preferably a compound having a maximal absorption wavelength in a wavelength range of 360 to 480 nm. In addition, the molar absorption coefficient of the oxime compound at a wavelength of 365 nm or 405 nm is preferably high, more preferably 1000 to 300000, still more preferably 2000 to 300000, and still more preferably 5000 to 200000 from the viewpoint of sensitivity. The molar absorption coefficient of the compound can be measured using a well-known method. For example, it is preferable that the molar absorption coefficient can be measured using a spectrophotometer (Cary-5 spectrophotometer, manufactured by Varian Medical Systems, Inc.) and ethyl acetate at a concentration of 0.01 g/L.
As the photopolymerization initiator, a photoradical polymerization initiator having two functional groups or three or more functional groups may he used. By using this photoradical polymerization initiator, two or more radicals are generated from one molecule of the photoradical polymerization initiator. Therefore, excellent sensitivity can be obtained. In addition, in a case where a compound having an asymmetric structure is used, crystallinity deteriorates, solubility in an organic solvent or the like is improved, precipitation is not likely to occur over time, and temporal stability of the composition can be improved. Specific examples of the photoradical polymerization initiator having two functional groups or three or more functional groups include a dimer of an oxime compound described in JP2010-527339A, JP2011-524436A, WO2015/004565A, paragraphs “0407” to “0412” of JP2016-532675A, or paragraphs “0039” to “0055” of WO2017/033680A, a compound (E) and a compound (G) described in JP2013-522445A, Cmpd 1 to 7 described in WO2016/034963A, an oxime ester photoinitiator described in paragraph “0007” of JP2017-523465A, a photoinitiator described in paragraphs “0020” to “0033” of JP2017-167399A, and a photopolymerization initiator (A) described in paragraphs “0017” to “0026” of JP2017-151342A.
In a case where the composition according to the embodiment of the present invention includes a photopolymerization initiator, the content of the photopolymerization initiator in the composition according to the embodiment of the present invention is preferably 0.1 mass % or higher, more preferably 0.2 mass % or higher, still more preferably 0.5 mass % or higher. The upper limit is preferably 10 mass % or lower, more preferably 5 mass % or lower, and still more preferably 3 mass % or lower. The content of the photopolymerization initiator is preferably 1 mass % or higher, more preferably 2 mass % or higher, and still more preferably 5 mass % or higher with respect to the total solid content of the composition according to the embodiment of the present invention. The upper limit is preferably 30 mass % or lower, more preferably 25 mass % or lower, and still more preferably 20 mass % or lower. In addition, the content of the photopolymerization initiator is preferably 10 to 1000 parts by mass with respect to 100 parts by mass of the polymerizable compound. The upper limit is preferably 500 parts by mass or less, more preferably 300 parts by mass or less, and still more preferably 100 parts by mass or less. The lower limit is preferably 20 parts by mass or more, more preferably 40 parts by mass or more, and still more preferably 60 parts by mass or more. The composition according to the embodiment of the present invention may include one photopolymerization initiator or two or more photopolymerization initiators. In a case where the composition according to the embodiment of the present invention includes two or more photopolymerization initiators, it is preferable that the total content of the two or more photopolymerization initiators is in the above-described range.
In addition, it is also preferable that the composition according to the embodiment of the present invention does not substantially include a photopolymerization initiator. A case where the composition according to the embodiment of the present invention does not substantially include the photopolymerization initiator represents that the content of the photopolymerization initiator is 0.005 mass % or lower, preferably 0.001 mass % or lower, and more preferably 0 mass % with respect to the total solid content of the composition.
<<Resin>>
The composition according to the embodiment of the present invention may further include a resin. The weight-average molecular weight (Mw) of the resin is preferably 3000 to 2000000. The upper limit is preferably 1000000 or lower and more preferably 500000 or lower. The lower limit is preferably 4000 or higher and more preferably 5000 or higher.
Examples of the resin include a (meth)acrylic resin, an enethiol resin, a poly carbonate resin, a polyether resin, a polyarylate resin, a polysulfone resin, a polyethersulfone resin, a polyphenylene resin, a polyarylene ether phosphine oxide resin, a polyimide resin, a polyamide imide resin, a polyolefin resin, a cyclic olefin resin, a polyester resin, a styrene resin, and a silicone resin. Among these resins, one kind may be used alone, or a mixture of two or more kinds may be used. In addition, a resin described in paragraphs “0041” and “0060” of JP2017-206689A, a resin described in paragraphs “0022” and “0071” of JP2018-010856A, a resin described in JP2017-057265A, a resin described in JP2017-032685A, a resin described in JP2017-075248A, a resin described in JP2017-066240A, or a resin described in paragraph “0016” of JP2018-145339A can also be used.
In the present invention, it is preferable that a resin having an acid group is also used as the resin. According to this aspect, in a case where a pattern is formed using a photolithography method, the developability can be further improved. Examples of the acid group include a carboxyl group, a phosphate group, a sulfo group, and a phenolic hydroxy group. Among these, a carboxyl group is preferable. The resin having an acid group can be used as, for example, an alkali-soluble resin.
It is preferable that the resin having an acid group further includes a repeating unit having an acid group at a side chain, and it is more preferable that the content of the repeating unit having an acid group at a side chain is preferably 5 to 70 mol % with respect to all the repeating units of the resin. The upper limit of the content of the repeating unit having an acid group at a side chain is preferably 50 mol % or lower and more preferably 30 mol % or lower. The lower limit of the content of the repeating unit having an acid group at a side chain is preferably 10 mol % or higher and more preferably 20 mol % or higher.
The acid value of the resin having an acid group is preferably 30 to 500 mgKOH/g. The lower limit is preferably 50 mgKOH/g or higher and more preferably 70 mgKOH/g or higher. The upper limit is preferably 400 mgKOH/g or lower, more preferably 300 mgKOH/g or lower, and still more preferably 200 mgKOH/g or lower. The weight-average molecular weight (Mw) of the resin having an acid group is preferably 5000 to 100000. In addition, the number-average molecular weight (Mn) of the resin having an acid group is preferably 1000 to 20000.
In a case where the composition according to the embodiment of the present invention includes a resin, the content of the resin in the composition according to the embodiment of the present invention is preferably 0.01 mass % or higher, more preferably 0.05 mass % or higher, still more preferably 0.1 mass % or higher. The upper limit is preferably 2 mass % or lower, more preferably 1 mass % or lower, and still more preferably 0.5 mass % or lower. The content of the resin is preferably 0.2 mass % or higher, more preferably 0.7 mass % or higher, and still more preferably 1.2 mass % or higher with respect to the total solid content of the composition according to the embodiment of the present invention. The upper limit is preferably 18 mass % or lower, more preferably 12 mass % or lower, and still more preferably 5 mass % or lower. The composition according to the embodiment of the present invention may include one resin or two or more resins. In a case where the composition according to the embodiment of the present invention includes two or more resins, it is preferable that the total content of the two or more resins is in the above-described range.
<<Adherence Improving Agent>>
The composition according to the embodiment of the present invention may further include an adherence improving agent. By the composition including the adherence improving agent, a film having excellent adhesiveness with a support can be formed. Preferable examples of the adherence improving agent include adherence improving agents described in JP1993-011439A (JP-H05-011439A), JP1993-341532A (JP-H05-341532A), and JP1994-043638A (JP-H06-043638A). Specific examples of the adherence improving agent include benzimidazole, benzoxazole, benzothiazole, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 3-morpholinomethyl-1-phenyl-triazole-2-thione, 3-morpholinomethyl-5-phenyl-oxadiazole-2-thione, 5-amino-3-morpholinomethyl-thiadiazole-2-thione, 2-mercapto-5-methylthiothiadiazole, triazole, tetrazole, benzotriazole, carboxybenzotriazole, an amino group-containing benzotriazole, and a silane coupling agent. As the adherence improving agent, a silane coupling agent is preferable.
As the silane coupling agent, a compound having an alkoxysilyl group as a hydrolyzable group that can form a chemical bond with an inorganic material is preferable. In addition, a compound having a group which interacts with a resin or forms a bond with a resin to exhibit affinity is preferable, and examples of the group include a vinyl group, a styryl group, a (meth)acryloyl group, a mercapto group, an epoxy group, an oxetanyl group, an amino group, an ureido group, a sulfide group, and an isocyanate group. Among these, a (meth)acryloyl group or an epoxy group is preferable.
As the silane coupling agent, a silane compound that has at least two functional groups having different reactivities in one molecule is also preferable. In particular, a compound having an amino group and alkoxy group as functional groups is preferable. Examples of the silane coupling agent include N-β-aminoethyl-γ-aminopropyl-methyldimethoxysilane (KBM-602, manufactured by Shin-Etsu Chemical Co., Ltd.), N-β-aminoethyl-γ-aminopropyl-trimethoxysilane (KBM-603, manufactured by Shin-Etsu Chemical Co., Ltd.), N-β-aminoethyl-γ-aminopropyl-triethoxysilane (KBE-602, trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), γ-aminopropyl-trimethoxysilane (KBM-903, trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), γ-aminopropyl-triethoxysilane (KBE-903, trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), and 3-methacryloxypropyltrimethoxysilane (KBM-503, trade name, manufactured by Shin-Etsu Chemical Co., Ltd.). As the silane coupling agent, the following compounds can also be used. In the following structural formulae, Et represents an ethyl group.
In a case where the composition according to the embodiment of the present invention includes an adherence improving agent, the content of the adherence improving agent is preferably 0.001 mass % or higher, more preferably 0.01 mass % or higher, still more preferably 0.1 mass % or higher with respect to the total solid content in the composition according to the embodiment of the present invention. The upper limit is preferably 20 mass % or lower, more preferably 10 mass % or lower, and still more preferably 5 mass % or lower. The composition according to the embodiment of the present invention may include one adherence improving agent or two or more adherence improving agents. In a case where the composition according to the embodiment of the present invention includes two or more adherence improving agents, it is preferable that the total content of the two or more adherence improving agents is in the above-described range. In addition, it is also preferable that the composition according to the embodiment of the present invention does not substantially include an adherence improving agent. A case where the composition according to the embodiment of the present invention does not substantially include the adherence improving agent represents that the content of the adherence improving agent is 0.0005 mass % or lower, preferably 0.0001 mass % or lower, and more preferably 0 mass % with respect to the total solid content of the composition according to the embodiment of the present invention.
<<Other Components>>
In the composition according to the embodiment of the present invention, the content of free metal which is neither bonded nor coordinated to the silica particles or the like is preferably 300 ppm or lower, more preferably 250 ppm or lower, still more preferably 100 ppm or lower, and still more preferably 0 ppm. Examples of the kind of the free metal include K, Sc, Ti, Mn, Cu, Zn, Fe, Cr, Co, Mg, Sn, Zr, Ga, Ge, Ag, Au, Pt, Cs, Ni, Cd, Pb, and Bi. Examples of a method of reducing the free metal in the composition include cleaning using ion exchange water, filtration, ultrafiltration, and a method such as purification using an ion exchange resin.
<<Use of Composition>>
The composition according to the embodiment of the present invention can be preferably used as a composition for forming an optical functional layer in an optical device such as a display panel, a solar cell, an optical lens, a camera module, or an optical sensor. Examples of the optical functional layer include an antireflection layer, a low refractive index layer, and a waveguide.
In addition, the composition according to the embodiment of the present invention can he preferably used as a composition for forming a partition wall. Examples of the partition wall include a partition wall used for dividing pixels adjacent to each other in a case where pixels are formed on an imaging area of a solid-state imaging element. Examples of the pixel include a colored pixel, a transparent pixel, and a pixel of a near infrared transmitting filter layer. For example, a partition wall for forming a grid structure for dividing pixels can be used. Examples of the partition wall include structures described in JP2012-227478A, JP2010-232537A, JP2009-111225A, FIG. 1 of JP2017-028241A, and FIG. 4D of JP2016-201524A, the contents of which are incorporated herein by reference. In addition, for example, a partition wall for forming a frame structure around an optical filter such as a color filter or a near infrared transmitting filter can be used. Examples of the partition wall include a structure described in JP2014-048596A, the content of which is incorporated herein by reference.
In addition, the composition according to the embodiment of the present invention can also be used for manufacturing an optical sensor or the like. Examples of the optical sensor include an image sensor such as a solid-state imaging element. Examples of one aspect of the optical sensor include a. configuration in which the film firmed using the composition according to the embodiment of the present invention is applied to an antireflection film on a microlens, an intermediate film, or a partition wall such as a grid disposed in a frame of a color filter or a near infrared transmitting filter or between pixels. Examples of one embodiment of the optical sensor include a structure configured with a light-receiving element (photodiode), a lower planarizing film, an optical filter, an upper planarizing film, or a microlens. Examples of the optical filter include a filter including a colored pixel of red (R), green (G), blue (B), or the like or a pixel of a near infrared transmitting filter layer.
<Method of Manufacturing Composition>
The composition according to the embodiment of the present invention can be manufactured by mixing the above-described compositions. During the manufacturing of the composition, it is preferable that the composition is filtered through a filter, for example, in order to remove foreign matter or to reduce defects. As the filter, any filter which is used in the related art for filtering or the like can be used without any particular limitation. Examples of a material of the filter include: a fluororesin such as polytetrafluoroethylene (PTFE); a polyamide resin such as nylon; and a polyolefin resin (including a polyolefin resin having a high density and an ultrahigh molecular weight) such as polyethylene or polypropylene (PP). Among these materials, polypropylene (including high-density polypropylene) or nylon is preferable.
The pore diameter of the filter is preferably 0.1 to 7 μm, more preferably 0.2 to 2.5 μm, still more preferably 0.2 to 1.5 μm, and still more preferably 0.2 to 0.7 μm. In a case where the pore diameter of the filter is in the above-described range, fine foreign matter can be more reliably removed. The pore diameter value of the filter can refer to a nominal value of a manufacturer of the filter. As the filter, various filters manufactured by Pall Corporation (for example, DFA4201NIEY), Toyo Roshi Kaisha, Ltd., Entegris Japan Co., Ltd. (former Mykrolis Corporation), or Kits Microfilter Corporation can be used.
In a filter is used, a combination of different filters may be used. At this time, the filtering using each of the filters may be performed once, or twice or more. In addition, a combination of filters having different pore diameters may be used.
<Storage Container>
A storage container of the composition according to the embodiment of the present invention is not particularly limited, and a well-known storage container can be used. In addition, as the storage container, in order to suppress infiltration of impurities into the raw materials or the composition, a multilayer bottle in which a container interior wall having a six-layer structure is formed of six kinds of resins or a bottle in which a container interior wall having a seven-layer structure is formed of six kinds of resins is preferably used. Examples of the container include a container described in JP2015-123351A.
In addition, it is also preferable that the interior wall of the storage container is formed of glass or stainless steel. According to this aspect, elution of metal from the container interior wall can be prevented, the storage stability of the composition can be improved, and component deterioration of the composition can be suppressed.
<Film>
Next, a film according to the embodiment of the present invention is formed of the above-described composition according to the embodiment of the present invention.
The refractive index of the film according to the embodiment of the present invention with respect to light having a wavelength of 633 nm is preferably 1.4 or lower, more preferably 1.35 or lower, still more preferably 1.3 or lower, and still more preferably 1.27 or lower. The above-described value of refractive index is a value at the measurement temperature of 25° C.
It is preferable that the film according to the embodiment of the present invention has sufficient hardness. The Young's modulus of the film is preferably 2 or higher, more preferably 3 or higher, and still more preferably 4 or higher. The upper limit value is, for example, preferably 10 or lower.
The thickness of the film according to the embodiment of the present invention can be appropriately selected depending on the purpose. For example, the thickness of the film is preferably 5 μm or less, more preferably 3 μm or less, and still more preferably 1.5 μm or less. The lower limit value is not particularly limited and is preferably 50 nm or more.
The film according to the embodiment of the present invention can be used as an optical functional layer or the like in an optical device such as a display panel, a solar cell, an optical lens, a camera module, or an optical sensor. Examples of the optical functional layer include an antireflection layer, a low refractive index layer, and a waveguide. In addition, the film according to the embodiment of the present invention can be used as a partition wall used for dividing pixels adjacent to each other in a case where pixels are formed on an imaging area of a solid-state imaging element.
<Film Forming Method>
A film forming method according to the present invention includes a step of applying the composition according to the embodiment of the present invention to a support using a spin coating method. Regarding the application using a spin coating method, in a case where the composition is applied to the support, a method (static dispense method) of adding the composition dropwise from the nozzle in a state where the rotation of the support is stopped and subsequently rapidly rotating the support may be performed. Alternatively, in a case where the composition is applied to the support, a method (dynamic dispense method) of adding the composition dropwise from the nozzle while rotating the support without stopping the rotation of the support may be performed. It is also preferable that the application using a spin coating method is performed while changing the rotation speed stepwise. For example, it is preferable that the film forming method includes a main rotation step for determining the film thickness and a dry rotation step for performing drying as desired. In addition, in a case where the time of the main rotation step is short at 10 seconds or shorter, the rotation speed of the subsequent dry rotation step for performing drying as desired is preferably 400 rpm to 1200 rpm and more preferably 600 rpm to 1000 rpm. In addition, from the viewpoints of suppressing striation and performing drying as desired, the time of the main rotation step preferably 1 second to 20 seconds, more preferably 2 seconds to 15 seconds, and still more preferably 2.5 seconds to 10 seconds. As the time of the main rotation step decreases in the above-described range, the occurrence of striation can be more effectively suppressed. In addition, in the case of the dynamic dispense method, in order to suppress wave-like coating unevenness, it is also preferable that a difference between the rotation speed during the dropwise addition of the composition and the rotation speed during the main rotation step decreases. In addition, during the coating using a spin coating method, the rotation speed may be increased as described in JP1998-142603A (JP-H10-142603A), JP1999-302413A (JP-H11-302413A), or JP2000-157922A. In addition, a spin coating process described in “Process Technique and Chemicals for Latest Color Filter” (Jan. 31, 2006, CMC Publishing Co., Ltd.) can also be suitably used.
The support to which the composition is applied is appropriately selected depending on the use. Examples of the support include a substrate such as a wafer formed of a material such as silicon, non-alkali glass, soda glass, PYREX (registered trade name) glass, or quartz glass. In addition, for example, an InGaAs substrate is preferably used. The InGaAs substrate has excellent sensitivity to light having a wavelength of longer than 1000 nm. Therefore, by forming the respective near infrared transmitting filter layers on the InGaAs substrate, an optical sensor having excellent sensitivity to light having a wavelength of longer than 1000 nm is likely to be obtained. In addition, a charge coupled device (CCD), a complementary metal-oxide semiconductor (CMOS), a transparent conductive film, or the like may be formed on the support. In addition, a black matrix formed of a light shielding material such as tungsten may also be formed on the support. In addition, an underlayer may be provided on the support to improve adhesiveness with a layer above the support, to prevent diffusion of materials, or to make a surface of the substrate flat. In addition, as the support, a microlens can also be used. By applying the composition according to the embodiment of the present invention to the microlens, a microlens unit having a surface coated with a film formed of the composition according to the embodiment of the present invention can be obtained. This microlens unit can be used in combination with an optical sensor such as a solid-state imaging element.
In addition, in a case where a wafer is used as the support, the diameter of the wafer is not particularly limited. Even in a case where a wafer having a large diameter is used, wave-like coating unevenness can be significantly suppressed. Therefore, even in a case where a wafer having a large diameter is used, the effects of the present invention can be obtained significantly. For example, the diameter of the wafer is preferably 8 inch (=20.32 cm) or more and more preferably 12 inch (=30.48 cm) or more. According to the investigation by the present inventors, it was found that, as the diameter of the wafer increases, in a. case where a composition including silica particles is applied to a support using a spin coating method, wave-like coating unevenness is more likely to occur on the surface. By using the composition according to the embodiment of the present invention, a surprising effect that the occurrence of wave-like coating unevenness can be suppressed even in a case where the diameter of the water is large can be obtained.
In the present invention, the composition layer formed on the support may be dried (pre-baked). It is preferable that drying is performed using a hot plate, an oven, or the like at a temperature of 50° C. to 140° C. for 10 seconds to 300 seconds.
In addition, the composition layer may be further heated (post-baked) after drying. The post-baking temperature is preferably 250° C. or lower, more preferably 240° C. or lower, and still more preferably 230° C. or lower. The lower limit is not particularly limited, and is preferably 50° C. or higher and more preferably 100° C. or higher.
In addition, in the present invention, an adhesion treatment may be performed on the composition layer that is dried (post-baked in a case where post-baking is performed). Examples of the adhesion treatment include a HMDS treatment. As the treatment, hexamethyldisilazane (HMDS) is used. In a case where HMDS is applied to the composition layer formed using the composition according to the embodiment of the present invention, HMDS reacts with a Si—OH bond present on the surface to form Si—O—Si(CH3)3. As a result, the surface of the composition layer can be made hydrophobic. This way, by making the surface of the composition layer hydrophobic, in a case where a resist pattern described below is formed on the composition layer, the infiltration of a developer into the composition layer can be prevented while improving the adhesiveness of the resist pattern.
The film forming method according to the embodiment of the present invention may further include a step of forming a pattern. Examples of the step of forming a pattern include a pattern forming method using a photolithography method and a pattern forming method using an etching method.
(Pattern Formation Using Photolithography Method)
First, a case where a pattern is formed with a photolithography method using the composition according to the embodiment of the present invention will be described. It is preferable that the pattern formation using the photolithography method includes: a step of applying the composition according to the embodiment of the present invention to a support using a spin coating method to form a composition layer; a step of exposing the composition layer in a patterned manner; and a step of forming a pattern by removing a non-exposed portion of the composition layer by development.
In the step of forming a composition layer, the composition according to the embodiment of the present invention is applied to a support using a spin coating method to form a composition layer. Examples of the support include the above-described examples. The composition layer formed on the support may be dried (pre-baked). It is preferable that drying is performed using a hot plate, an oven, or the like at a temperature of 50° C. to 140° C. for 10 seconds to 300 seconds.
Next, the composition layer is exposed in a patterned manner (exposure step). For example, the composition layer can be exposed in a patterned manner using a stepper exposure device or a scanner exposure device through a mask having a predetermined mask pattern. As a result, an exposed portion can be cured.
Examples of radiation (light) used during the exposure include a g-ray and an i-ray. In addition, light having a wavelength of 300 nm or shorter (preferably light having a wavelength of 180 to 300 nm) can also be used. Specific examples of the light having a wavelength of 300 nm or shorter include a KrF ray (wavelength: 248 nm) and an ArF ray (wavelength: 193 nm). Among these, a KrF ray (wavelength: 248 nm) is preferable. In addition, a long-wavelength light source of 300 nm or longer can also be used.
In addition, during the exposure, the composition may be continuously irradiated with and exposed to light or may be irradiated with and exposed to pulses of the light (pulse exposure). The pulse exposure refers to an exposure method in which light irradiation and rest are repeated in a cycle of a short period of time (for example, a level of milliseconds or lower). In the case of pulse exposure, the pulse duration is preferably 100 nanoseconds (ns) or shorter, more preferably 50 nanoseconds or shorter, and still more preferably 30 nanoseconds or shorter. The lower limit of the pulse duration is not particularly limited and may be 1 femtosecond (fs) or longer or 10 femtoseconds (fs) or longer. The frequency is preferably 1 kHz or higher, more preferably 2 kHz or higher, and still more preferably 4 kHz or higher. The upper limit of the frequency is preferably 50 kHz or lower, more preferably 20 kHz or lower, and still more preferably 10 kHz or lower. The maximum instantaneous illuminance is preferably 50000000 W/m2 or higher, more preferably 100000000 W/m2 or higher, and still more preferably 200000000 W/m2 or higher. In addition, the upper limit of the maximum instantaneous illuminance is preferably 1000000000 W/m2 or lower, more preferably 800000000 W/m2 or lower, and still more preferably 500000000 W/m2 or lower. The pulse duration refers to the time during which light is irradiated during a pulse period. In addition, the frequency refers to the number of pulse periods per second. In addition, the maximum instantaneous illuminance refers to an average illuminance within a time during which light is irradiated in a pulse period. In addition, the pulse period refers to a period in which light irradiation and rest during pulse exposure are set as one cycle.
The irradiation dose (exposure dose) is preferably 0.03 to 2.5 J/cm2, and more preferably 0.05 to 1.0 J/cm2. The oxygen concentration during exposure can be appropriately selected. The exposure may be performed not only in air but also in a low-oxygen atmosphere having an oxygen concentration of 19 vol % or lower (for example, 15 vol %, 5 vol %, or substantially 0 vol %) or in a high-oxygen atmosphere having an oxygen concentration of higher than 21 vol % (for example, 22 vol %, 30 vol %, or 50 vol %). In addition, the exposure illuminance can be appropriately set and typically can be selected in a range of 1000 W/m2 to 100000 W/m2 (for example, 5000 W/m2, 15000 W/m2, or 35000 W/m2). Conditions of the oxygen concentration and conditions of the exposure illuminance may be appropriately combined. For example, conditions are oxygen concentration: 10 vol % and illuminance: 10000 W/m2, or oxygen concentration: 35 vol % and illuminance: 20000 W/m2.
Next, a pattern is formed by removing a non-exposed portion of the composition layer by development. The non-exposed portion of the composition layer can be removed by development using a developer. As a result, a non-exposed portion of the composition layer in the exposure step is eluted into the developer, and only the photocured portion remains. Examples of the developer include an alkali developer and an organic solvent. Among these, an alkali developer is preferable. For example, the temperature of the developer is preferably 20° C. to 30° C. The development time is preferably 20 to 180 seconds.
As the alkali developer, an alkaline aqueous solution in which the above alkaline agent (alkali developer) is diluted with pure water is preferable. Examples of the alkaline agent include: an organic alkaline compound such as ammonia, ethylamine, diethylamine, dimethylethanolamine, diglycolamine, diethanolamine, hydroxyamine, ethylenediamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, ethyltrimethylammonium hydroxide, benzyltrimethylammonium hydroxide, dimethyl bis(2-hydroxyethyl)ammonium hydroxide, choline, pyrrole, piperidine, or 1,8-diazabicyclo[5.4.0]-7-undecene; and an inorganic alkaline compound such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, sodium silicate, or sodium metasilicate. From the viewpoints of environment and safety, it is preferable that the alkaline agent is a compound having a high molecular weight. A concentration of the alkaline agent in the alkaline aqueous solution is preferably 0.001 to 10 mass % and more preferably 0.01 to 1 mass %. In addition, the developer may further include a surfactant. Examples of the surfactant include the above-described surfactants. Among these, a nonionic surfactant is preferable. From the viewpoint of easiness of transport, storage, and the like, the developer may be obtained by temporarily manufacturing a concentrated solution and diluting the concentrated solution to a necessary concentration during use. The dilution factor is not particularly limited and, for example, can be set to be in a range of 1.5 to 100 times. In addition, it is also preferable that the composition is rinsed with pure water after development. In addition, it is preferable that, during rinsing, a rinsing liquid is supplied to the developed composition layer while rotating the support on which the developed composition layer is formed. In addition, it is also preferable that, during rinsing, a nozzle through which the rinsing liquid is ejected is moved from a center portion of the support to a peripheral portion of the support. At this time, during the movement of the nozzle from the center portion to the peripheral portion of the support, the moving speed of the nozzle may be gradually decreased. By performing rinsing as described above, an in-plane variation of rinsing can be suppressed. In addition, even in a case where the rotation speed of the support is gradually decreased while moving the nozzle from the center portion to the peripheral portion of the support, the same effects can be obtained.
It is preferable that, after the development and drying, an additional exposure treatment or a heating treatment (post-baking) is performed. The additional exposure treatment or the post-baking is a curing treatment which is performed after development to completely cure the film. The heating temperature during post-baking is preferably 250° C. or lower, more preferably 240° C. or lower, and still more preferably 230° C. or lower. The lower limit is not particularly limited, and is preferably 50° C. or higher and more preferably 100° C. or higher. In a case where the additional exposure treatment is performed, the light used for exposure is preferably light having a wavelength of 400 nm or shorter. In addition, the additional exposure treatment may be performed using a method described in KR10-2017-0122130A.
(Pattern Formation Using Etching Method)
Next, a case where a pattern is formed with an etching method using the composition according to the embodiment of the present invention will be described. It is preferable that the pattern formation using an etching method includes: a step of applying the composition according to the embodiment of the present invention to a support using a spin coating method to form a. composition layer and curing the entire composition layer to form a cured composition layer; a step of forming a photoresist layer on the cured composition layer; a step of exposing the photoresist layer in a patterned manner and developing the exposed photoresist layer to form a resist pattern; a step of etching the cured composition layer using this resist pattern as a mask; and a step of peeling and removing the resist pattern from the cured composition layer.
A resist used for forming the resist pattern is not particularly limited. For example, a resist including an alkali-soluble phenol resin and naphthoquinone diazide described in pp. 16 to 22 of “Polymer New Material One Point 3, Microfabrication and Resist, Saburo Nonomura, Published by Kyoritsu Shuppan Co., Ltd. (First Edition, Nov. 15, 1987) can be used. In addition, a resist described in Examples of JP2568883B, JP2761786B, JP2711590B, JP2987526B, JP3133881B, JP3501427B, JP3373072B, JP3361636B, or JP1994-054383A (JP-H06-054383A) can also be used. In addition, as the resist, a so-called chemically amplified resist can also be used. Examples of the chemically amplified resist include a resist described in p. 129˜ of New Developments of Photo-functional Polymer Materials”, (May 31, 1996, first print, edited by Kunihiro Ichimura, published by CMC) (in particular, a resist including a polyhydroxystyrene resin in which a hydroxyl group is protected by an acid-decomposable group that is described in about page 131 or an ESCAP (Environmentally Stable Chemical Amplification Positive Resist) type resist that is described in about page 131 is preferable). In addition, a resist described in, for example, Examples of JP2008-268875A, JP2008-249890A, JP2009-244829A, JP2011-013581A, JP2011-232657A, JP2012-003070A, JP2012-003071A, JP3638068B, JP4006492B, JP4000407B, or JP4194249B can also be used.
A method of etching the cured composition layer may be dry etching or wet etching. Among these, dry etching is preferable.
It is preferable to dry-etching the cured composition layer by using mixed gas of fluorine gas and O2 as etching gas. A mixing ratio (fluorine gas/O2) of fluorine gas to O2 is preferably 4/1 to 1/5 and more preferably 1/2 to 1/4 by flow rate ratio. Examples of the fluorine gas include CF4, C2F6, C3F8, C2F4, C4F8, C4F6, C5F8, and CHF3. Among these, C4F6, C5F8, C4F8, or CHF3 is preferable, C4F6 or C5F8 is more preferable, and C4F6 is still more preferable. As the fluorine gas, one kind of gas can be selected from the above-described group, and a mixed gas including two or more kinds of gases may be used.
From the viewpoint of maintaining partial pressure control stability of etching plasma and verticality of an etched shape, the mixed gas may further include, in addition to the fluorine gas and O2, noble gas such as helium (He), neon (Ne), argon (Ar), krypton (Kr), or xenon (Xe). As another other gas that may be mixed, one kind of gas or two or more kinds of gases can be selected from the above-described group. In a case where the flow rate ratio of O2 is represented by 1, the mixing ratio of the other gas that may be used is preferably higher than 0 and 25 or lower, more preferably 10 to 20, and still more preferably 16.
The internal pressure of a chamber during dry etching is preferably 0.5 to 6.0 Pa and more preferably 1 to 5 Pa.
Examples of dry etching conditions include conditions described in paragraphs “0102” to “0108” of WO2015/190374A or JP2016-014856A, the contents of which are incorporated herein by reference.
The film forming method according to the embodiment of the present invention is also applicable to manufacturing of an optical sensor or the like.
Next, the present invention will be described using Examples, but the present invention is not limited thereto. Unless specified otherwise, amounts or ratios shown in Examples are represented by mass.
<Method of Measuring Kinetic Viscosity>
The kinetic viscosity of a measurement sample was measured using a Ubbelohde viscometer.
<Method of Measuring Surface Tension>
After adjusting the temperature of the measurement sample to 25° C., the surface tension of a measurement sample was measured with a plate method using a platinum plate and a surface tensiometer CBVP-Z (manufactured by Kyowa Interface Science Co., Ltd.) as a measuring device.
<Preparation of Composition>
The respective components were mixed to obtain a composition shown in the following table and were filtered through DFA4201NIEY (0.45 μm nylon filter, manufactured by Pall Corporation) to obtain a composition. Numerical values of the mixing amounts in the following table are represented by “part(s) by mass”. In addition, the mixing amount of a silica particle solution is the value of SiO2 in the silica particle solution. A numerical value of the mixing amount of the solvent is the sum of the amounts of the solvents included in the silica particle solution. In addition, the content of the silicone-based surfactant with respect to the total solid content of the composition is also shown in the following tables.
The raw materials shown above in the table are as follows.
(Silica Particle Solution)
P1: a solution of silica particles (beaded silica particles) having a shape in which a plurality of spherical silica particles having an average particle diameter of 15 nm were linked in a beaded shape through metal oxide-containing silica (linking material)
P2: THRULYA 4110 (manufactured by JGC C&C, a solution of silica particles (silica particles having a hollow structure) having an average particle diameter of 60 nm and a concentration of solid contents of 20 mass % in terms of SiO2; the solution of the silica particles not including silica particles having a shape in which a plurality of spherical silica particles were linked in a beaded shape and silica particles having a shape in which a plurality of spherical silica particles were linked in a planar shape)
As the average particle diameter of the spherical silica particles in the silica particle solution P1, a number average value of circle equivalent diameters of projection images of spherical portions of 50 spherical silica particles measured using a transmission electron microscope (TEM) was calculated and obtained. In addition, whether or not each of the silica particle solutions P1 and P2 included silica particles having a shape in which a plurality of spherical silica particles were linked in a beaded shape and silica particles having a shape in which a plurality of spherical silica particles were linked in a planar shape was investigated using a method of TEM observation.
(Silicone-Based Surfactant)
F1: a compound having the following structure (a carbinol-modified silicone compound, weight-average molecular weight=3000, kinetic viscosity at 25° C.=45 mm2/s)
F2: Silwet L-7220 (manufactured by Momentive Performance Materials Inc., a compound having the following structure (polyether-modified silicone compound, n:m=20:80 (molar ratio), weight-average molecular weight=17000, kinetic viscosity at 25° C.=1100 mm2/s)
(Other Surfactants)
rF1: MEGAFACE F-551 (manufactured by DIC Corporation, fluorine-based surfactant)
(Polymerizable Compound)
M1: KAYARAD DPHA (manufactured by Nippon Kayaku Co., Ltd.)
M2: a compound having the following structure
(Resin)
B1: a resin having the following structure (a numerical value added to a main chain represents a molar ratio; Mw=11000)
(Photopolymerization Initiator)
I1: IRGACURE-OXE01 (manufactured by BASF SE)
I2: a compound having the following structure
(Solvent)
S1: 1,4-butanediol diacetate (boiling point: 232° C., viscosity: 3.1 mPa·s, molecular weight: 174)
S2: propylene glycol monomethyl ether acetate (boiling point: 146° C. viscosity: 1.1 mPa·s, molecular weight: 132)
S3: propylene glycol monomethyl other boiling point: 120° C., molecular weight: 90, viscosity: 1.8 mPa·s)
S4: ethanol, methanol, a mixture thereof (boiling point of methanol: 64° C., viscosity of methanol: 0.6 mPa·s, boiling point of ethanol: 78° C., viscosity of ethanol: 1.2 mPa·s)
S5: water (boiling point: 100° C., viscosity: 0.9 mPa·s)
<Evaluation of Surface Tension>
The surface tension of the composition obtained as described above was measured using the above-described method.
<Evaluation of Contact Angle>
The composition obtained as described above was applied to a glass substrate and was heated at 200° C. for 5 minutes to form a film having a thickness of 0.5 μm. The contact angle of the obtained film with water at 25° C. was measured using a contact angle meter (DM-701, manufactured by Kyowa Interface Science Co., Ltd.).
<Evaluation of Refractive Index>
In a clean room of class 1000, the composition obtained as described above was applied to a silicon wafer having a diameter of 12 inch (=30.48 cm) using a spin coating method such that the thickness after the application was 0.3 μm. The rotation speed of the silicon wafer after the application was 1500 rpm. Next, the coating film was heated at 200° C. for 5 minutes such that a film having a thickness of 0.3 μm was formed. The refractive index of the obtained film was measured using an ellipsometer (VUV-vase (trade name), manufactured by J. A. Woollam Co., Inc.) (wavelength: 633 nm, measurement temperature: 25° C.).
<Evaluation of Coating Properties>
In a clean room of class 1000, the composition obtained as described above was applied to a silicon wafer having a diameter of 12 inch (=30.48 cm) using a spin coating method such that the thickness after the application was 0.6 μm. The rotation speed of the silicon wafer after the application was 1500 rpm. Next, the applied composition was heated at 100° C. for 2 minutes and was heated at 220° C. for 5 minutes. As a result, a film was formed.
A wafer end surface of the obtained film was observed with an optical microscope (magnification: 200-fold) to check whether or not wave-like coating unevenness occurred. Wave-like unevenness occurred at an angle of 45 degrees with respect to the normal line of the silicon water was wave-like coating unevenness.
3: wave-like coating unevenness was not observed
2: a small amount of wave-like coating unevenness was observed
1: a large amount of wave-like coating unevenness was observed
<Coating Properties of Composition for Forming Top Coat Layer>
In a clean room of class 1000, the composition obtained as described above was applied to a silicon wafer having a diameter of 12 inch (=30.48 cm) using a spin coating method such that the thickness after the application was 0.6 μm. The rotation speed of the silicon wafer after the application was 1500 rpm. Next, the applied composition was heated at 100° C. for 2 minutes and was heated at 220° C. for 5 minutes. As a result, a film was formed.
CT-4000L (manufactured by Fujifilm Electronic Materials Co., Ltd.) as a composition for forming a top coat layer was applied to the obtained film such that the thickness thereof after post-baking was 0.1 μm. Next, the coating film was heated (post-baked) using a hot plate at 220° C. for 5 minutes to form a top coat layer. The top coat layer was observed by visual inspection to evaluate the coating properties of the composition for forming a top coat layer based on the following standards.
1: a top coat layer having no cissing was able to be formed
2: cissing was observed on the top coat layer or the top coat layer was not able to be formed
As shown in the tables, with the composition according to Examples, a film having excellent coating properties and having suppressed occurrence of wave-like coating unevenness was able to be formed. In addition, a top coat layer having no cissing was also able to be formed on the film formed of the composition according to Examples, and the coating properties of the composition for forming a top coat layer were also excellent.
In a case where each of partition walls 40 to 43 shown in FIG. 1 of JP2017-028241A was formed using the composition according to Examples to form an image sensor shown in FIG. 1 of JP2017-028241A, this image sensor had excellent sensitivity.
<Manufacturing of Partition Wall>
The composition according to Examples was applied to a silicon wafer having a diameter of 12 inch (=30.48 cm) using a spin coating method. Next, the coating film was heated using a hot plate at 100° C. for 2 minutes and was further heated at 230° C., for 2 minutes. As a result, a composition layer having a thickness of 0.5 μm was formed. Next, a positive type photoresist (FFPS-0283, manufactured by Fujifilm Electronic Materials Co., Ltd.) was applied to the composition layer using a spin coating method and was heated at 90° C. for 1 minute. As a result, a photoresist layer having a thickness of 1.0 μm was formed. Next, using a KrF scanner exposure device (FPA6300ES6a, manufactured by Canon Inc.), the photoresist layer was exposed through a mask at an exposure dose of 16 J/cm2 and was heated at 100° C. for 1 minute. Next, the photoresist layer was developed using a developer (FHD-5, manufactured by Fujifilm Electronic Materials Co., Ltd.) for 1 minute and was heated at 100° C. for 1 minute. As a result, a mesh-like pattern having a line width of 0.12 μm and a pitch width of 1 μm was formed. By using this pattern as a photomask, the film was patterned using a dry etching method under conditions described in paragraphs “0129” and “0130” of JP2016-014856A. As a result, partition walls having a width of 0.1 μm and a height of 0.5 μm were formed in a lattice form at an interval of 1 μm. The dimension of an opening of the partition walls on the silicon wafer (a region corresponding to one pixel divided by the partition walls on the silicon water) was length 0.9 μm×width 0.9 μm.
1: spherical silica
2: bonding portion
This application is a Continuation of PCT International Application No. PCT/JP2020/012819 filed on Mar. 24, 2020, which claims priority under 35 U.S.C § 119(a) to Japanese Patent Application No. 2019-065537 filed on Mar. 29, 2019. Each of the above application(s) is hereby expressly incorporated by reference, in its entirety, into the present application.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2020/012819 | Mar 2020 | US |
| Child | 17477815 | US |
