Patent Application
20090081462
The present invention relates to a long fiber filler reinforced resin pellet. The present invention also relates to a resin pellet blend including the long fiber filler reinforced resin pellet, a molded article produced by melt-molding of the long fiber filler reinforced resin pellet, etc., a process for producing the long fiber filler reinforced resin pellet, and the like.
Since a thermoplastic resin has superior formability, it is used broadly for an automobile and machine related use, building materials, housing equipment parts and the like. Among others a thermoplastic resin composition reinforced by compounding glass fibers is very valuable for reduction of a part weight and the number of parts, by replacing metal materials owing to its superior mechanical strength and moldability. Further, since the reinforced thermoplastic resin compositions have excellent impact strength (especially, surface impact strength) and rigidity, they are used broadly for components receiving a high load, or components receiving repeated loads.
Patent Literature 1 discloses a pultrusion method, by which a glass fiber roving is impregnated while a resin strand being drawn to obtain pellets, in which the length of the reinforcing fiber and the length of the pellet are identical, as a realizing means for a long fiber filler reinforced composition. The method is still now most popularly utilized.
However a long fiber reinforced resin composition has difficulty in wettability of fibers with the resin, because the contact time between the resin and the fibers is limited, as compared with a usual short fiber reinforced resin composition, which is prepared by melt-blending in an extruder with short fibers such as chopped strand, so that studies have been made to improve the wettability.
For instance, Patent Literature 2 discloses a method to select a thermoplastic resin having a considerably low melt viscosity, so that continuous aligned filaments can be well wetted by the thermoplastic resin.
Further, Patent Literature 3 discloses a technique to improve flexibility or buckling strength of a long fiber strand by twisting the same, and Patent Literature 4 discloses a production process with high productivity by means of such twisting.
[Patent Literature 1] Japanese Patent Publication No. 52-3985
[Patent Literature 2] Japanese Patent Publication No. 63-37694
[Patent Literature 3] Japanese Patent Application Laid-Open No. 05-169445
[Patent Literature 4] Japanese Patent Application Laid-Open No. 2003-175512
However according to the technique disclosed by Patent Literature 2, the interface strength between a resin and fibers is insufficient that the produced pellets may cause longitudinal fractures during transportation, or a long fiber filler may detach from a pellet to cause such phenomenon that the detached long fiber filler sticks on a product bag or a hopper of a molding machine and, as a consequence, the market has been requesting improvement thereof. Further, since the interface strength between a resin and fibers is insufficient and the pellet surface is not glossy, the friction resistance between pellets becomes higher, which causes another problem of defective feeding into a molding machine.
In case, for example, polypropylene or polyamide is used as a resin, and subjected to strong twisting based on the technologies disclosed by Patent Literatures 3 and 4, the twisted long fibers are not well fibrillated due to the melt viscosity of the resin during fabrication in a molding machine, which results in insufficient exhibition of potential properties of high heat resistance or impact strength.
An object of the present invention is to provide a long fiber filler reinforced resin pellet, having good wettability between the long fiber filler and a thermoplastic resin blend, extremely suppressing longitudinal fracture of a pellet during pellet transportation and detachment of a long fiber filler from a pellet, showing good pellet appearance, and further having superior fibrillation property of a long fiber filler during molding, enabling to mold a molded article with extremely high heat resistance and impact strength.
The present inventors have intensively studied to find a solution for the above object and have discovered that, by aligning in a pellet the long fiber filler in a long fiber filler reinforced resin pellet forming a spiral with a central axis along the longitudinal direction of the pellet, the above object can be attained, thereby completing the invention.
The present invention provides a long fiber filler reinforced resin pellet, a resin pellet blend including the long fiber filler reinforced resin pellet, a molded article produced by melt-molding of the long fiber filler reinforced resin pellet, etc., a process for producing the long fiber filler reinforced resin pellet, and the like, as described below.
1.
A long fiber filler reinforced resin pellet, comprising a long fiber filler and a thermoplastic resin blend, wherein:
the long fiber filler is, in said pellet, to form a spiral with a central axis along a longitudinal direction of said pellet; and
said pellet has a skin layer part with a lower content of the long fiber filler, and a core part with a higher content of the long fiber filler, a cross-section of said core part being in a range from 30% to 70% of the cross-section of said pellet; and
said thermoplastic resin blend comprises polyphenylene ether and a thermoplastic resin other than polyphenylene ether.
2.
The long fiber filler reinforced resin pellet according to 1., wherein a ratio of an average fiber length of said long fiber filler to the length of said long fiber filler reinforced resin pellet exceeds 1.0.
3.
The long fiber filler reinforced resin pellet according to 1. or 2., wherein a rate of said long fiber filler in said long fiber filler reinforced resin pellet is 30 to 70% by mass.
4.
The long fiber filler reinforced resin pellet according to any one of 1.-3., wherein said long fiber filler is a glass fiber.
5.
The long fiber filler reinforced resin pellet according to any one of 1.-4., wherein a reduced viscosity (a chloroform solution of 0.5 g/dL concentration, measured at 30° C.) of said polyphenylene ether is in a range from 0.30 to 0.55 dL/g.
6.
The long fiber filler reinforced resin pellet according to any one of 1.-5., wherein said polyphenylene ether is a copolymer comprising 2,3,6-trimethylphenol, and a rate of a unit of said 2,3,6-trimethylphenol in the polyphenylene ether is from 10 to 30% by mass.
7.
The long fiber filler reinforced resin pellet according to any one of 1.-6., wherein said thermoplastic resin other than the polyphenylene ether is one or more selected from the group consisting of a styrenic resin, an olefinic resin, polyester, polyamide, polyarylene sulfide, polyarylate, polyetherimide, polyethersulfone, polysulfone and polyaryl ketone.
8.
The long fiber filler reinforced resin pellet according to any one of 1.-7., wherein said thermoplastic resin other than the polyphenylene ether is one or more selected from the group consisting of homo-polystyrene, rubber-modified polystyrene, acrylonitrile-styrene copolymer and N-phenylmaleimide-styrene copolymer.
9.
The long fiber filler reinforced resin pellet according to 8., wherein a rate of said polyphenylene ether in said thermoplastic resin blend is from 10 to 90% by mass.
10.
The long fiber filler reinforced resin pellet according to any one of 1.-7., wherein said thermoplastic resin other than the polyphenylene ether is one or more selected from the group consisting of polypropylene, liquid crystal polyester, polyamide, polyarylene sulfide, polyarylate, polyetherimide, polyethersulfone, polysulfone and polyaryl ketone.
11.
The long fiber filler reinforced resin pellet according to 10., wherein the rate of said polyphenylene ether in said thermoplastic resin blend is from 1 to 50% by mass.
12.
The long fiber filler reinforced resin pellet according to any one of 1.-11., further comprising a compatibilizer.
13.
The long fiber filler reinforced resin pellet according to 12., wherein said compatibilizer is a compound having one or more functional groups selected from the group consisting of an epoxy group, an oxazolyl group, an imide group, a carboxylic group and an acid anhydride group.
14.
The long fiber filler reinforced resin pellet according to any one of 1.-13., further comprising a sterically-hindered phenol-based antioxidant in an amount from 0.1 to 5 parts by mass based on 100 parts by mass of said thermoplastic resin blend.
15.
The long fiber filler reinforced resin pellet according to any one of 1.-14., further comprising a flame retardant without halogen in an amount from 5 to 50 parts by mass based on 100 parts by mass of said thermoplastic resin blend.
16.
The long fiber filler reinforced resin pellet according to any one of 1.-15., further comprising a filler other than the long fiber filler.
17.
A resin pellet blend comprising:
100 parts by mass of the long fiber filler reinforced resin pellet according to any one of 1.-16.; and
0.5 to 150 parts by mass of a resin pellet without the long fiber filler.
18.
The resin pellet blend according to 17., wherein a rate of said long fiber filler in said resin pellet blend is from 10 to 60% by mass.
19.
The resin pellet blend according to 17. or 18., wherein said resin pellet without the long fiber filler further comprises a filler other than the long fiber filler.
20.
The resin pellet blend according to 19., wherein said filler other than the long fiber filler is one or more fillers selected from the group consisting of a hydroxide of an element selected from magnesium and calcium, an oxide of an element selected from the group consisting of magnesium, titanium, iron, copper, zinc and aluminum; zinc sulfide, zinc borate, calcium carbonate, talc, wollastonite, glass, carbon black, carbon nanotube and silica; and an average particle size of said filler other than the long fiber filler is not more than 1 mm.
21.
A molded article produced by melt-molding of the long fiber filler reinforced resin pellet according to any one of 1.-16.
22.
A process for producing a long fiber filler reinforced resin pellet, wherein the pellet comprises a long fiber filler and a thermoplastic resin blend;
said long fiber filler is aligned, in said pellet, to form a spiral with a central axis along a longitudinal direction of said pellet; and
said pellet comprises a skin layer part with a lower content of the long fiber filler, and a core part with a higher content of the long fiber filler, the cross-section of said core part being in a range from 30% to 70% of the cross-section of said pellet;
said thermoplastic resin blend comprises polyphenylene ether and a thermoplastic resin other than polyphenylene ether; and
the process for producing the long fiber filler reinforced resin pellet comprises the steps of:
(1) producing said thermoplastic resin blend in a molten state by an extruder,
(2) impregnating said long fiber filler with said thermoplastic resin blend in the molten state,
(3) forming a resin strand by drawing and twisting, and
(4) cutting said resin strand to a pellet form.
23.
The process for producing the long fiber filler reinforced resin pellet according to 22., wherein the process for producing the long fiber filler reinforced resin pellet comprises the steps (1) to (4) in said successive order.
24.
The process for producing the long fiber filler reinforced resin pellet according to 22. or 23., wherein the step (1) further comprising producing said thermoplastic resin blend in the molten state by blending said polyphenylene ether and said thermoplastic resin other than the polyphenylene ether.
25.
The process for producing the long fiber filler reinforced resin pellet according to any one of 22.-24., wherein a set temperature of a dipping bath in the step (2), in which said long fiber filler is impregnated in said thermoplastic resin blend in the molten state, is higher by 20° C. or more than a set temperature of the extruder in said step (1).
26.
The process for producing the long fiber filler reinforced resin pellet according to any one of 22.-25., wherein a drawing speed in said step (3) is in a range from 10 to 150 m/min.
According to the present invention, a long fiber filler and a thermoplastic resin blend have good wettability, which suppresses extremely longitudinal fracture of a pellet during transportation and detachment of a long fiber filler from a pellet, offers good pellet appearance and superior fibrillation property of a long fiber filler during molding, and can provide a long fiber filler reinforced resin pellet able to mold a molded article with extremely high heat resistance and impact strength.
The best mode for carrying out the present invention (hereinafter referred to as “the Embodiment”) will be explained in more detail below. The present invention should not be limited to the following Embodiment, and various changes may be made therein within the spirit of the invention.
A long fiber filler reinforced resin pellet according to the Embodiment (hereinafter occasionally abbreviated simply as “the pellet”) is a pellet composed of a long fiber filler and a thermoplastic resin blend.
The long fiber filler is aligned in the pellet forming a spiral with the central axis along the longitudinal direction of the pellet, the lead of the spiral is 20 mm to 80 mm, the pellet has a skin layer part with a lower content of the long fiber filler and a core part with a higher content of the long fiber filler, and the cross-section of the core part is in a range of 30% to 70% of the cross-section of the pellet.
The thermoplastic resin blend (hereinafter occasionally abbreviated simply as “the resin”) contains polyphenylene ether and a thermoplastic resin other than polyphenylene ether.
The long fiber filler to be used in the long fiber filler reinforced resin pellet according to the Embodiment is aligned in the pellet forming a spiral with the central axis along the longitudinal direction of the pellet, the lead of the spiral is 20 mm to 80 mm, the pellet has a skin layer part with a lower content of the long fiber filler and a core part with a higher content of the long fiber filler, and the cross-section of the core part is in a range of 30% to 70% of the cross-section of the pellet.
In the Embodiment, the long fiber filler is aligned in the pellet forming a spiral with the central axis along the longitudinal direction of the pellet, thereby the longitudinal direction of the pellet means the extending direction of the long fiber filler, and, in case the pellet form is a cylindrical pellet, the direction of its height.
In the Embodiment, “aligned forming a spiral” means that the long fiber filler exists in the pellet in a twisted state.
In the Embodiment, since the long fiber filler is aligned in the pellet forming a spiral with the central axis along the longitudinal direction of the pellet, longitudinal fracture of the pellet during transportation and detachment of the long fiber filler from the pellet can be suppressed.
In the Embodiment, the long fiber filler may exist as a fiber bundle forming a spiral in the pellet, so that detachment of the long fiber filler from the pellet can be suppressed, forming the pellet of excellent appearance. More preferably, the fiber bundle of the long fiber filler forms a single bundle in the pellet.
In the Embodiment, a long fiber filler is “not aligned in a spiral form” means that the long fiber filler exists in the pellet in a not twisted state, and examples of a pellet without alignment in a spiral form include pellets disclosed by Patent Literature 1 and Patent Literature 2.
In the Embodiment, the lead of a spiral has the same meaning as the lead of a screw, and specifically, it means a distance along the longitudinal direction over the strand surface, which a long fiber filler aligned in spiral advances in rotating once (360°) around the outer surface of a strand.
In the Embodiment, with the lead of the spiral of 20 mm or longer, deterioration of the pellet appearance due to detachment at the interface between the resin and the long fiber filler, or deterioration of the fibrillation property during molding may be suppressed. Further, with the lead of the spiral of 80 mm or shorter, longitudinal fracture of the pellet during transportation, detachment of the long fiber filler from the pellet and defective feeding into a molding machine during molding may be suppressed.
In the Embodiment, the lead of the spiral is preferably 25 mm or longer, more preferably 27 mm or longer, and further preferably 30 mm or longer. Further, the lead of the spiral is preferably 75 mm or shorter, more preferably 60 mm or shorter, and further preferably 55 mm or shorter.
In the Embodiment, the pellet has a skin layer part with a lower content of the long fiber filler, and a core part with a higher content of the long fiber filler, and the cross-section of the core part is in a range of 30% to 70% of the cross-section of the pellet.
The skin layer part with a lower content of the long fiber filler means a region continued from the pellet surface composed of the resin, in which the fill content of the filled long fiber filler is less than half of the fill content of the filled long fiber filler in the pellet as a whole, and for example, if the fill content of the long fiber filler in the pellet is 40% by mass, the region with the fill content of the long fiber filler less than 20% by mass is meant as the skin layer part. In the Embodiment, however, a region with half or less of the fill content of the long fiber filler in the pellet is also deemed as the core part and excluded from the skin layer part, if categorized in the following case: as the long fiber filler exists in a twisted state, an envelope of the long fiber filler may be defined in the pellet, and the region inside the envelope surrounded by the region containing the long fiber filler, namely the region not continuing from the surface is excluded from the skin layer part.
In the Embodiment, the core part with a higher content of the long fiber filler means a part of the cross-section of the pellet excluding the skin layer part with a lower content of the long fiber filler. In the Embodiment, since the long fiber filler is added in the pellet in a twisted state, it exists in an aggregated form in the pellet, and the skin layer part and the core part can be easily discriminated by observing the cross-section of the pellet under a microscope.
In the Embodiment, by limiting the cross-section of the core part within 30 to 70% of the cross-section of the pellet, the appearance of the pellet can be substantially improved and an effect of improvement of the feed property into a molding machine is obtainable. As for the pellet appearance, glossy appearance can be obtained providing a pellet with high quality appearance.
In the Embodiment, the cross-section of the core part is preferably 35% or more of the cross-section of the pellet, more preferably 40% or more, and further preferably 45% or more. Further, the cross-section of the core part is preferably 65% or less of the cross-section of the pellet, and more preferably 60% or less.
In the Embodiment, the cross-section of the core part may be determined by observing at least 10 cross-sections of a pellet and averaging the cross-sections of the core part, as described in more detail in an Example below.
In the Embodiment, the length of the long fiber filler (“the fiber length”) is preferably 3 mm or longer, more preferably 4 mm or longer and further preferably 5-mm or longer, in order to make high enough the heat resistance and impact strength of a molded article produced by melt-molding of the long fiber filler reinforced resin pellet, etc. (hereinafter occasionally abbreviated simply as “molded article”). Further, the length of the long fiber filler is preferably 50 mm or shorter, from the viewpoint of the handling property at molding, more preferably 30 mm or shorter, and further preferably 20 mm or shorter.
In the Embodiment, concerning the fiber length of the long fiber filler, in order to obtain a pellet with excellent appearance and fewer longitudinal fracture, the fiber length of the contained long fiber filler is preferably longer than the length of the pellet containing the long fiber filler, and more preferably the ratio of the average fiber length of the long fiber filler to the length of the pellet exceeds 1.0.
Further preferably, the ratio of the average fiber length of the long fiber filler to the length of the pellet is in a range of 1.01 to 1.2, further preferably 1.02 or higher, and especially preferably 1.03 or higher. Meanwhile, the ratio of the average fiber length of the long fiber filler to the length of the pellet is more preferably 1.15 or lower, further preferably 1.1 or lower, and especially preferably 1.08 or lower.
In the Embodiment, the length of a pellet means the length of the longitudinal direction of the pellet, and for example in case of a cylindrical pellet it means the height.
In the Embodiment, the content of the long fiber filler in the pellet is preferably 30 to 70% by mass.
By keeping the content of the long fiber filler in the pellet at 30% by mass or higher, drawing property during pellet production can be improved and the viscosity of the strand during pellet production can be kept at an appropriate viscosity level. Further, by keeping the content of the long fiber filler in the pellet at 70% by mass or lower, penetration of the resin into the long fiber filler can be improved to enhance the wettability, by which the drawing speed of the strand during pellet production can be controlled comfortably.
More preferably, the content of the long fiber filler in the pellet is 40% by mass or higher, and further preferably 45% by mass or higher. And the content of the long fiber filler in the pellet is more preferably 60% by mass or lower, and further preferably is 55% by mass or lower.
In the Embodiment, examples of a long fiber filler to be used for the long fiber filler reinforced resin pellet include one or more long fiber filler selected from the group consisting of a carbon fiber, a glass fiber, a metal fiber and an aramid fiber may be exemplified.
In the Embodiment, the long fiber filler is preferably one or more selected from a carbon fiber and a glass fiber, and is more preferably a glass fiber from the viewpoint of enhancement of strength and rigidity of an molded article of the long fiber filler reinforced resin pellet according to the embodiment.
In the Embodiment, although there is no particular restriction on the diameter of the long fiber filler, it is preferably 5 μm or larger, more preferably 8 μm or larger, and further preferably 10 μm or larger. And preferably the diameter of the long fiber filler is 25 μm or shorter, more preferably 20 μm or shorter, and further preferably 17 μm or shorter.
In the Embodiment, the long fiber filler, which surface is coated appropriately with a coupling agent, a binder, etc. in order to improve the wettability or handling property of the resin, may be used.
Examples of a coupling agent include an amino, epoxy, chlor, mercapto and cationic silane coupling agents, and an amino silane coupling agent can be favorably used.
As a binder, a binder containing one or more selected from: a maleic anhydride compound, a urethane compound, an acryl compound, an epoxy compound and a copolymer of such compounds; may be exemplified, and a binder containing a urethane compound can be favorably used.
A favorable content of a binder in the long fiber filler is 0.1 to 0.5% by mass. By coating a binder on the surface of the long fiber filler at the content of 0.1% by mass or higher, the longitudinal fracture of the pellet can be prevented, and by coating a binder on the surface of the long fiber filler at the content of 0.5% by mass or lower, the fibrillation property of the long fiber filler at the step of impregnating the long fiber filler with the resin is not deteriorated and deterioration of the productivity can be suppressed.
The content of a binder is more preferably 0.15% by mass or higher, further preferably 0.2% by mass, and still further preferably 0.25% by mass or higher. And the content of a binder is more preferably 0.45% by mass or lower, further preferably 0.4% by mass or lower, and still further preferably 0.35% by mass or lower.
In the Embodiment, a thermoplastic resin blend used for the long fiber filler reinforced resin pellet is composed of polyphenylene ether and a thermoplastic resin other than polyphenylene ether.
In the Embodiment, by use of polyphenylene ether in the thermoplastic resin blend the melt viscosity of the resin is increased appropriately and the twisted long fiber filler can be extremely easily fibrillated during molding.
By the improved fibrillation property during molding, the effect of the use of the long fiber filler, namely high strength and rigidity of a molded article can be achieved to a maximum extent.
In the Embodiment, polyphenylene ether is a homo- or copolymer having a recurring structural unit represented by the following formula (1).
wherein O represents an oxygen atom, and R1 to R4 independently represent a group selected from the group consisting of hydrogen, halogen, a linear or branched C1 to C7 alkyl group, a phenyl group, a C1 to C7 haloalkyl group, a C1 to C7 aminoalkyl group, a C1 to C7 hydrocarbyloxy group and a halohydrocarbyloxy group, provided that a halogen atom and an oxygen atom are separated by at least 2 carbon atoms.
In the Embodiment, there is no particular restriction on the production process of polyphenylene ether, so far as it is a publicly known process. Examples of a production process include those disclosed by U.S. Pat. No. 3,306,874, U.S. Pat. No. 3,306,875, U.S. Pat. No. 3,257,357, U.S. Pat. No. 3,257,358, Japanese Patent Application Laid-Open No. 50-51197, Japanese Patent Publication No. 52-17880 and Japanese Patent Publication No. 63-152628.
Examples of polyphenylene ether include poly(2,6-dimethyl-1,4-phenylene ether), poly(2-methyl-6-ethyl-1,4-phenylene ether), poly(2-methyl-6-phenyl-1,4-phenylene ether), poly(2,6-dichloro-1,4-phenylene ether).
As a copolymer of polyphenylene ether, a copolymer of 2,6-dimethylphenol with other phenols may be exemplified, for example, a copolymer with 2,3,6-trimethylphenol or a copolymer with 2-methyl-6-butylphenol.
From the standpoint of commercial availability, poly(2,6-dimethyl-1,4-phenylene ether), a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol, or the blend thereof is preferable as polyphenylene ether. In case a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol is used, concerning the contents of the respective monomer units, a copolymer containing 10 to 30% by mass of the structural unit of 2,3,6-trimethylphenol in the polyphenylene ether copolymer is preferable, more preferable 15 to 25% by mass, and further preferable 20 to 25% by mass.
In the Embodiment, the reduced viscosity (ηsp/c: dL/g, a chloroform solution of 0.5 g/dL concentration, measured at 30° C.) of polyphenylene ether is preferably in a range of 0.30 to 0.55 dL/g. The reduced viscosity of the polyphenylene ether is more preferably 0.53 dL/g or lower, further preferably 0.45 dL/g or lower, and still further preferably 0.36 dL/g or lower.
By making the reduced viscosity of the polyphenylene ether at 0.30 dL/g or higher, a pellet with superior fibrillation property of the long fiber filler during molding can be obtained, and at 0.55 dL/g or lower, the wettability can be improved.
In the Embodiment, a blend of 2 or more types of polyphenylene ether having different reduced viscosities can be used without particular restrictions. Examples include a blend of a polyphenylene ether with the reduced viscosity of approximately 0.40 dL/g and a polyphenylene ether with the reduced viscosity of approximately 0.50 dL/g, and a blend of a low molecular weight polyphenylene ether with the reduced viscosity of approximately 0.08 to 0.12 dL/g and a polyphenylene ether with the reduced viscosity of approximately 0.50 dL/g.
In case a blend of 2 or more types of polyphenylene ether having different reduced viscosities is used, the reduced viscosity of the blended polyphenylene ether is preferably in a range of 0.30 to 0.55 dL/g.
In the Embodiment, the polyphenylene ether may be modified using a modifier, and examples of a modifier include saturated or unsaturated dicarboxylic acids and derivatives thereof, such as maleic anhydride, N-phenylmaleimide, malic acid, citric acid and fumaric acid; and vinyl compounds, such as styrene, acrylic ester and methacrylic ester.
In case a modified polyphenylene ether is used as the polyphenylene ether, the same may be modified in advance, or may be modified by adding a modifier during melt-extrusion to produce the resin.
(Thermoplastic Resin Other than Polyphenylene Ether)
Although there is no particular restriction on the thermoplastic resin other than polyphenylene ether, an example thereof is one or more selected from the group consisting of a styrenic resin, an olefinic resin, polyester, polyamide, polyarylene sulfide, polyarylate, polyetherimide, polyethersulfone, polysulfone and polyaryl ketone. The thermoplastic resin other than polyphenylene ether may be used alone or as a blend of the above thermoplastic resins.
A preferable thermoplastic resin other than the polyphenylene ether is one or more selected from the group consisting of polypropylene, liquid crystal polyester, polyamide, polyarylene sulfide, polyarylate, polyetherimide, polyethersulfone, polysulfone, polyaryl ketone, homo-polystyrene, rubber-modified polystyrene, acrylonitrile-styrene copolymer and N-phenylmaleimide-styrene copolymer.
In case, as a thermoplastic resin other than the polyphenylene ether, one or more thermoplastic resins having relatively low affinity to the polyphenylene ether selected from the group consisting of an olefinic resin such as polypropylene, polyester such as liquid crystal polyester, polyamide, polyarylene sulfide, polyarylate, polyetherimide, polyethersulfone, polysulfone and polyaryl ketone are used, the content of the polyphenylene ether in the resin is preferably in a range of 1 to 50% by mass. The content of the polyphenylene ether in the resin is more preferably 5% by mass or higher, further preferably 10% by mass or higher, and still further preferably 15% by mass or higher. And the content of the polyphenylene ether in the resin is more preferably 45% by mass or lower, further preferably 40% by mass or lower, and still further preferably 35% by mass or lower.
By making the content of the polyphenylene ether 1% by mass or higher, the heat resistance of the polymer can be favorably enhanced. From the standpoint of inhibition of deterioration of the wettability with the long fiber filler, the content of the polyphenylene ether is preferably 50% by mass or lower.
In case, as a thermoplastic resin other than the polyphenylene ether, one or more polystyrenic resins, which are thermoplastic resins having relatively high affinity to the polyphenylene ether, selected from the group consisting of homo-polystyrene, rubber-modified polystyrene, acrylonitrile-styrene copolymer and N-phenylmaleimide-styrene copolymer, the content of the polyphenylene ether in the resin is preferably in a range of 10 to 90% by mass. The content of the polyphenylene ether is more preferably 20% by mass or higher, and further preferably 30% by mass or higher. And the content of the polyphenylene ether is more preferably 80% by mass or lower, further preferably 70% by mass or lower, and still further preferably 60% by mass or lower.
In the Embodiment, examples of a styrenic resin include homo-polystyrene, rubber-modified polystyrene (generally called as high-impact polystyrene), styrene-butadiene block-copolymer and/or a hydrogenated product thereof, styrene-isoprene block-copolymer and/or a hydrogenated product thereof, and a copolymer of styrene and radically copolymerizable vinyl monomer.
Specific examples of a vinyl monomer radically copolymerizable with styrene include vinyl cyanide compounds, such as acrylonitrile and methacrylonitrile; vinyl carboxylic acids and esters thereof, such as acrylic acid, butyl acrylate, methacrylic acid, methyl methacrylate and ethylhexyl methacrylate; unsaturated dicarboxylic anhydrides and derivatives thereof, such as maleic anhydride and N-phenylmaleimide; and diene compounds, such as butadiene and isoprene, and two or more of them may be combined and copolymerized.
From the viewpoint of commercial availability, examples of a preferable styrenic resin include homo-polystyrene, rubber-modified polystyrene, acrylonitrile-styrene copolymer, N-phenylmaleimide-styrene copolymer and a blend thereof.
Concerning homo-polystyrene and rubber-modified polystyrene, from the viewpoint of maintenance of balance between flowability and mechanical strength of the obtained thermoplastic resin blend, homo-polystyrene and rubber-modified polystyrene having the reduced viscosity (measured at 30° C. in a toluene solution of 0.5 g/100 mL concentration) in a range 0.5 to 2.0 dL/g are preferable. The reduced viscosity of homo-polystyrene and rubber-modified polystyrene is more preferably 0.7 dL/g or higher and further preferably 0.8 dL/g or higher. And the reduced viscosity of homo-polystyrene and rubber-modified polystyrene is preferably 1.5 dL/g or lower and more preferably 1.2 dL/g or lower.
Concerning an acrylonitrile-styrene copolymer, from the viewpoint of chemical resistance and heat resistance of the obtained thermoplastic resin blend, an acrylonitrile-styrene copolymer containing 3 to 30% by mass of acrylonitrile in the copolymer as a structural unit is preferable.
The content of acrylonitrile in the copolymer is more preferably 5% by mass or higher, and further preferably 7% by mass or higher. And the content of acrylonitrile in the copolymer is more preferably 20% by mass or lower, further preferably 15% by mass or lower, and further preferably 10% by mass or lower.
The acrylonitrile-styrene copolymer may be a copolymer further copolymerized with butadiene in an amount of 30 parts by mass or less based on 100 parts by mass of the acrylonitrile-styrene copolymer.
As an N-phenylmaleimide-styrene copolymer, from the viewpoint of heat resistance of the obtained thermoplastic resin blend and affinity to polyphenylene ether, an N-phenylmaleimide-styrene copolymer having 15 to 70% by mass of N-phenylmaleimide in the copolymer as a structural unit is preferable.
The content of N-phenylmaleimide in the copolymer is more preferably 20% by mass or higher, and further preferably 25% by mass or higher. And the content of N-phenylmaleimide in the copolymer is more preferably 65% by mass or lower, and further preferably 60% by mass or lower.
The N-phenylmaleimide-styrene copolymer may be a copolymer further copolymerized with acrylonitrile in an amount of 30 parts by mass or less based on 100 parts by mass of the N-phenylmaleimide-styrene copolymer.
From the viewpoint of maintaining the heat resistance of the obtained thermoplastic resin blend, the glass transition temperature of an N-phenylmaleimide-styrene copolymer is preferably in a range of 140° C. to 220° C.
In the Embodiment, the glass transition temperature is, for example, the glass transition temperature observed by a DSC apparatus measured at the temperature elevation speed of 20° C./min.
In the Embodiment, examples of an olefinic resin include polyethylene, polypropylene, an ethylene-α-olefin copolymer and an ethylene-acrylate copolymer, and polypropylene (hereinafter occasionally abbreviated simply as “PP”) is preferable.
In the Embodiment, examples of polypropylene include a crystalline propylene homopolymer and a crystalline propylene-ethylene block copolymer composed of a crystalline propylene homopolymer portion produced in the first polymerization step and a propylene-ethylene random copolymer portion produced in the second or later polymerization step by copolymerizing propylene, ethylene and/or at least one other α-olefin, such as 1-butene and 1-hexene. Polypropylene may be a blend of a crystalline propylene homopolymer and a crystalline propylene-ethylene block copolymer.
In general, polypropylene is produced by polymerization using a titanium trichloride catalyst or a titanium halide catalyst supported on a magnesium chloride support or the like in the presence of an alkyl aluminum compound, in a polymerization temperature range of 0 to 100° C., and a polymerization pressure range of 3 to 100 atm. Thereby a chain transfer agent such as hydrogen may be added to regulate the molecular weight of a polymer. As a polymerization process, both a batch process and a continuous process are possible, and a solution polymerization or a slurry polymerization using a solvent, such as butane, pentane, hexane, heptane and octane may be selected, and further, a bulk polymerization in a monomer without a solvent, or a gas phase polymerization in a monomer gas may be applied.
In order to enhance the isotacticity of polypropylene and polymerization activity, as an third component an electron donating compound may be used as an internal donor component or an external donor component. As an electron donating compound, such publicly known compounds as exemplified may be used: ester compounds, such as ∈-caprolactone, methyl methacrylate, ethyl benzoate and methyl toluate; phosphites, such as triphenyl phosphite and tributyl phosphite; phosphoric acid derivatives, such as hexamethylphosphoric triamide; alkoxyester compounds; aromatic monocarboxylic acid esters and/or aromatic alkylalkoxysilanes; aliphatic hydrocarbon alkoxysilanes; various ether compounds; and various alcohols and/or various phenols.
In the Embodiment, the density of a propylene polymer portion in polypropylene is generally 0.90 g/cm3 or higher, preferably 0.90 to 0.93 g/cm3, and more preferably 0.90 to 0.92 g/cm3.
The density of a propylene polymer portion can be easily measured by an underwater replacement method according to JIS K-7112. In case polypropylene is a copolymer containing propylene as a main component and α-olefin, a copolymer portion is extracted from the polypropylene by a solvent such as hexane, and the density of the residual propylene polymer portion can be easily measured by the above underwater replacement method according to JIS K-7112.
In the Embodiment, it is effective to increase the density of the polypropylene by adding a publicly known nucleating agent. Although there is no restriction on the type of a nucleating agent insofar as crystallization of polypropylene can be promoted, examples may include organic nucleating agents, such as a metal salt of an aromatic carboxylic acid, a sorbitol derivative, an organic phosphate and an aromatic amide compound; and inorganic nucleating agents such as talc.
In the Embodiment, from the viewpoint of improving the wettability of the long fiber filler with the thermoplastic resin blend, the MFR (according to JIS K-6758: 230° C., load 21.2 N) of polypropylene is preferably 10 g/10 min or higher, more preferably 20 to 50 g/10 min, further preferably 25 to 40 g/10 min, and still further preferably 30 to 40 g/10 min.
In the Embodiment, examples of polyester include polybutylene terephthalate, polypropylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polypropylene naphthalate and liquid crystal polyesters; and among them liquid crystal polyesters are preferable.
In the Embodiment, the liquid crystal polyester means such polyester as is called as a thermotropic liquid crystal polymer. Examples of a thermotropic liquid crystal polymer include, but not limited thereto, a thermotropic liquid crystal polyester containing p-hydroxybenzoic acid, alkylene glycol or terephthalic acid as a main structural unit, a thermotropic liquid crystal polyester containing p-hydroxybenzoic acid and 2-hydroxy-6-naphthoic acid as main structural units, and a thermotropic liquid crystal polyester containing p-hydroxybenzoic acid and 4,4′-dihydroxybiphenyl as well as terephthalic acid as main structural units.
As the liquid crystal polyester to be used in the Embodiment, the following structural units (A) and (B) and, as necessary, (C) and/or (D) may be favorably used.
The structural units (A) and (B) are respectively a structural unit of polyester derived from p-hydroxybenzoic acid and a structural unit derived from 2-hydroxy-6-naphthoic acid.
By incorporating the structural units (A) and (B), a resin having a good balance of heat resistance, flowability and mechanical properties such as rigidity can be obtained.
The X in the structural units (C) and (D) is one or two or more groups independently selected from the following group:
The structural unit (C) is preferably a structural unit derived from ethylene glycol, hydroquinone, 4,4′-dihydroxybiphenyl, 2,6-dihyroxynaphthalene, bisphenol A, etc., more preferably a structural unit derived from ethylene glycol, 4,4′-dihydroxybiphenyl and hydroquinone, and further preferably a structural unit derived from ethylene glycol and 4,4′-dihydroxybiphenyl.
The structural unit (D) is preferably a structural unit derived respectively from terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, etc., and more preferably a structural unit derived from 2,6-naphthalenedicarboxylic acid and terephthalic acid.
The structural unit (C) or (D) may use one or more of the above-described structural units simultaneously. In case more than one are used simultaneously, concerning the structural unit (C), for example, a structural unit derived from ethylene glycol and a structural unit derived from hydroquinone, a structural unit derived from ethylene glycol and a structural unit derived from 4,4′-dihydroxybiphenyl, as well as a structural unit derived from hydroquinone and a structural unit derived from 4,4′-dihydroxybiphenyl may be exemplified. Concerning the structural unit (D), a structural unit derived from terephthalic acid and a structural unit derived from isophthalic acid as well as a structural unit derived from terephthalic acid and a structural unit derived from 2,6-naphthalenedicarboxylic acid may be exemplified.
Although there are no particular restrictions on the usage ratio among the structural units (A), (B), (C) and (D) in a liquid crystal polyester, it is basically preferable that the structural units (C) and (D) are used in substantially same molar quantities.
The following structural unit (E) constituted of the structural units (C) and (D) may be used as a structural unit in a liquid crystal polyester.
O—X—OCO—X—CO [Formula]7
(E)
The X in the structural unit (E) is same as described above.
Specific examples of the structural unit (E) include a structural unit derived from ethylene glycol and a structural unit derived from terephthalic acid, a structural unit derived from hydroquinone and a structural unit derived from terephthalic acid, a structural unit derived from 4,4′-dihydroxybiphenyl and a structural unit derived from terephthalic acid, a structural unit derived from 4,4′-dihydroxybiphenyl and a structural unit derived from isophthalic acid, a structural unit derived from bisphenol A and a structural unit derived from terephthalic acid, as well as a structural unit derived from hydroquinone and a structural unit derived from 2,6-naphthalenedicarboxylic acid.
In the Embodiment, the liquid crystal polyester may, according to need and in a small amount to the extent that the characteristics and effects of the Embodiment are not impaired, employ a structural unit derived from other aromatic dicarboxylic acids, aromatic diols and aromatic hydroxycarboxylic acids.
In the Embodiment, by melting a liquid crystal polyester, the temperature at which a liquid crystal phase starts to appear (hereinafter referred to as “LC transition temperature”) is preferably in the range from 150 to 350° C., and more preferably in the range from 180 to 320° C. By setting the LC transition temperature in said range, the obtained resin can have a favorable color tone and a good balance of heat resistance and moldability.
As a specific measuring method of the LC transition temperature in the Embodiment, the liquid crystal polyester is observed under a polarizing microscope with a heated stage by heating the same at a temperature elevating rate of 1° C./min, to find a temperature at which an anisotropic molten phase is observed.
In the Embodiment, the dielectric tangent (tan δ) of a liquid crystal polyester at 25° C., 1 MHz is preferably 0.03 or less, and more preferably 0.025 or less.
In the Embodiment, the dielectric tangent is a value determined by a measuring method according to JIS-K6911. The smaller the dielectric tangent is, the smaller the dielectric loss is, which is preferable for suppressing generation of electric noises, when the resin is used as a raw material for electrical/electronic parts. The dielectric tangent (tan δ), especially at 25° C. in a high frequency region, namely in a region of 1 to 10 GHz, is preferably 0.03 or less, and more preferably 0.025 or less.
In the Embodiment, the apparent melt viscosity of a liquid crystal polyester (at LC transition temperature+30° C., under a shear rate of 100 sec−1) is preferably 10 to 3,000 Pa·s, more preferably 10 to 2,000 Pa·s, and further preferably 10 to 1,000 Pa·s. By making the apparent melt viscosity in the above-described region, the flowability of the resin becomes favorable.
In the Embodiment, as a specific measuring method of the apparent melt viscosity, a method to measure a viscosity at the aforementioned shear rate with a capillary rheometer may be exemplified.
In the Embodiment, there is no restriction on the type of polyamide, insofar as an amide bond {—NH—C(═O)—} is included in a recurring structure of a polymer.
Examples of a manufacturing process of a polyamide include, but not limited thereto, ring-opening polymerization of lactams, polycondensation of a diamine and a dicarboxylic acid, and polycondensation of an aminocarboxylic acid.
In the Embodiment, examples of a diamine include aliphatic diamine, alicyclic diamine and aromatic diamine.
Specific examples of a diamine include tetramethylenediamine, hexamethylenediamine, undecamethylenediamine, dodecamethylenediamine, tridecamethylenediamine, 1,9-nonanediamine, 2-methyl-1,8-octanediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 5-methylnonamethylenediamine, 1,3-bisaminomethylcyclohexane, 1,4-bisaminomethylcyclohexane, m-phenylenediamine, p-phenylenediamine, m-xylylenediamine and p-xylylenediamine.
In the Embodiment, examples of a dicarboxylic acid include aliphatic dicarboxylic acid, alicyclic dicarboxylic acid and aromatic dicarboxylic acid.
Specific examples of a dicarboxylic acid include adipic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, 1,1,3-tridecanedioic acid, 1,3-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid and dimer acid.
In the Embodiment, examples of lactams include ∈-caprolactam, enantholactam and ω-laurolactam.
In the Embodiment, examples of an aminocarboxylic acid include ∈-aminocaproic acid, 7-aminoheptanoic acid, 8-aminooctanoic acid, 9-aminononanoic acid, 11-aminoundecanoic acid, 12-aminododecanoic acid and 13-aminotridodecanoic acid.
In the Embodiment, examples of polyamide copolymers obtained by polycondensation of one or a mixture of two or more of lactams, diamine, dicarboxylic acid and/or ω-aminocarboxylic acid may be used as a polyamide. Further, polyamide copolymers obtained by polymerizing lactams, diamine, dicarboxylic acid and/or ω-aminocarboxylic acid in a polymerization reactor to a low molecular weight oligomer stage, and then in an extruder or the like reacting it to a high molecular weight, may be also favorably used.
Examples of a polyamide resin to be used favorably as a polyamide of the Embodiment include polyamide 6, polyamide 66, polyamide 46, polyamide 11, polyamide 12, polyamide 610, polyamide 612, polyamide 6/66, polyamide 6/612, polyamide MXD (m-xylylenediamine) 6, polyamide 6T, polyamide 6I, polyamide 6/6T, polyamide 6/6I, polyamide 66/6T, polyamide 66/6I, polyamide 6T/6I, polyamide 6/6T/6I, polyamide 66/6T/6I, polyamide 6/12/6T, polyamide 66/12/6T, polyamide 6/12/6I, polyamide 66/12/6I and polyamide 9T; wherein polyamide 6I means a polyamide resin polymerized between hexamethylenediamine and isophthalic acid, and polyamide 6/6T means a polyamide copolymer resin among ∈-aminocarboxylic acid, hexamethylenediamine and terephthalic acid. Further, two or more of the above polyamide resins may be additionally copolymerized in an extruder or the like and used as a polyamide.
As the polyamide of the Embodiment, from the viewpoint of the improvement of the heat resistance of a molded article of the obtained long fiber filler reinforced pellet, a polyamide having an aromatic ring in a recurring structural unit is preferable. Specific examples include polyamide MXD (m-xylylenediamine) 6, polyamide 6T, polyamide 6I, polyamide 6/6T, polyamide 6/6I, polyamide 66/6T, polyamide 66/6I, polyamide 6T/6I, polyamide 6/6T/6I, polyamide 66/6T/6I, polyamide 6/12/6T, polyamide 66/12/6T, polyamide 6/12/6I, polyamide 66/12/6I and polyamide 9T; wherein polyamide 6T/6I, polyamide 66/6T/6I and polyamide 9T are more preferable, and polyamide 9T is further preferable. A mixture of the preferable polyamides may be also used.
In the Embodiment, the viscosity of a polyamide measured in 96% sulfuric acid according to ISO 307 is preferably in a range of 70 to 160 mL/g, and more preferably in a range of 80 to 150 mL/g.
If the viscosity of a polyamide is 70 mL/g or higher, the drawing property of a strand during pellet production can be well regulated, and if it is 160 mL/g or lower, the wettability between the long fiber filler and the resin can be well regulated.
As the polyamide of the Embodiment, a mixture of two or more polyamides of the same polyamide type but with different viscosity numbers may be used. Examples of a mixture of polyamides include a mixture of a polyamide with the viscosity number of 170 mL/g and a polyamide with the viscosity number of 80 mL/g, and a mixture of a polyamide with the viscosity number of 120 mL/g and a polyamide with the viscosity number of 115 mL/g.
The viscosity of a mixture of polyamides, which can be measured after dissolving the mixture of polyamides in 96% sulfuric acid according to ISO 307, is preferably in the above-described range.
In the Embodiment, the terminal amino group concentration of a polyamide is preferably 5 μmol/g or higher, more preferably 10 μmol/g or higher, further preferably 12 μmol/g or higher, and still further preferably 15 μmol/g or higher in order to improve the compatibility between a polyamide and a polyphenylene ether. In order to regulate well the wettability between the long fiber filler and the resin, the terminal amino group concentration of a polyamide is preferably 45 μmol/g or lower, more preferably 40 μmol/g or lower, further preferably 35 μmol/g or lower, and still further preferably 30 μmol/g or lower.
In the Embodiment, the terminal carboxyl group concentration of a polyamide is preferably 20 μmol/g or higher from the viewpoint of flowability or mechanical properties such as rigidity of the resin, and more preferably 30 μmol/g or higher; and preferably 150 μmol/g or lower, more preferably 100 μmol/g or lower, and further preferably 80 μmol/g or lower.
In the Embodiment, although there is no particular restriction on the ratio of the terminal amino group concentration to the terminal carboxyl group concentration of a polyamide (terminal amino group concentration/terminal carboxyl group concentration), it is preferably 1.0 or less from the viewpoint of mechanical properties, more preferably 0.9 or less, further preferably 0.8 or less, and still further preferably 0.7 or less. And by making the ratio of the terminal amino group concentration to the terminal carboxyl group concentration of a polyamide 0.1 or higher, the pellet can be stably produced.
In the Embodiment, a publicly known method can be used as a regulating method of the terminal amino group concentration and the terminal carboxyl group concentration of a polyamide. For example, a method of adding a terminal regulating agent, such as a diamine compound, a monoamine compound, a dicarboxylic compound, a monocarboxylic compound, an acid anhydride, monoisocyanate, a monoacid halide, monoesters and monoalcohols, to reach the predetermined terminal concentrations in a polymerization stage of the polyamide resin, may be exemplified.
Examples of a terminal regulating agent reacting with a terminal amino group include aliphatic monocarboxylic acids, such as acetic acid, propionic acid, lactic acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid, pivalic acid and isobutyric acid; alicyclic monocarboxylic acids, such as cyclohexane carboxylic acid; aromatic monocarboxylic acids, such as benzoic acid, toluic acid, α-naphthalenecarboxylic acid, β-naphthalenecarboxylic acid, methylnaphthalenecarboxylic acid and phenylacetic acid; and a mixture of a plurality of compounds arbitrarily selected therefrom. Preferable monocarboxylic acid compounds are, in view of reactivity, stability of capped termini, price, etc., acetic acid, propionic acid, lactic acid, valeric acid, caproic acid, caprylic acid, lauric acid, tridecanoic acid, myristic acid, palmitic acid, stearic acid and benzoic acid, and more preferable is benzoic acid.
Examples of a terminal regulating agent reacting with a terminal carboxyl group include aliphatic monoamines, such as methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, stearylamine, dimethylamine, diethylamine, dipropylamine and dibutylamine; alicyclic monoamines, such as cyclohexylamine and dicyclohexylamine; aromatic monoamines, such as aniline, toluidine, diphenylamine and naphthylamine; and a mixture of a plurality of compounds arbitrarily selected therefrom. Preferable monoamine compounds are, in view of reactivity, a boiling point, stability of capped termini, price, etc., butylamine, hexylamine, octylamine, decylamine, stearylamine, cyclohexylamine and aniline.
In the Embodiment, in view of its accuracy and easiness, the concentrations of a terminal amino group and a terminal carboxyl group of a polyamide are preferably determined from integral values of the characteristic signals corresponding to the respective terminal groups by 1H-NMR, for example, according to the method disclosed by Japanese Patent Application Laid-Open No. 07-228775. A favorable solvent for the measurement is deuterated trifluoroacetic acid. Even measuring by an apparatus with sufficient resolving power, the number of scanning for summation by 1H-NMR is preferably at least 300 cycles.
The measurement of the concentration of a terminal amino group or terminal carboxyl group of a polyamide can be made also by a measurement method using titration as disclosed by Japanese Patent Application Laid-Open No. 2003-55549.
To avoid influences of coexisting additives or lubricants, quantitative measurement by 1H-NMR is more preferable.
In the Embodiment, by regulating terminal amino groups and/or terminal carboxyl groups using a terminal capping agent, active termini are capped therewith. If, for example, benzoic acid belonging to a monocarboxylic acid is used as a terminal capping agent, a terminal group capped with a terminal phenyl group is generated.
In the Embodiment, the concentration of the capped terminal groups in a polyamide is preferably 20% or higher, more preferably 40% or higher, further preferably 45% or higher, and still further preferably 50% or higher. While, the concentration of the capped terminal groups in a polyamide is preferably 85% or lower, more preferably 80% or lower, and further preferably 75% or lower.
In the Embodiment, the capped terminus rate of a polyamide can be calculated according to the following mathematical formula using the measured numbers of terminal carboxylic groups, terminal amino groups and terminal groups capped by a terminal capping agent existing in the polyamide:
Capped terminus rate (%)=[(α−β)/α]×100
wherein α represents the total number of terminal groups of molecular chains (generally equal to 2 times the polyamide molecule number), β represents the summed number of uncapped residual terminal carboxylic groups and terminal amino groups.
In the Embodiment, the water content of a polyamide is preferably in a range of 500 to 3,000 ppm, and more preferably in a range of 500 to 2,000 ppm.
By making the water content of a polyamide 500 ppm or higher, a pellet with a favorable color tone can be obtained, and making it 3,000 ppm or lower, sharp viscosity decrease of the resin can be inhibited.
In the Embodiment, the measurement method of the water content is based on a water vaporization method specifically according to ISO 15512 Method B.
In the Embodiment, polyarylene sulfide is a polymer containing a recurring unit of arylene sulfide represented by the following formula generally in the amount of 50 mol % or more, preferably 70 mol % or more, and more preferably 90 mol % or more:
[—Ar—S—]
wherein Ar represents an arylene group.
In the Embodiment, examples of an arylene group include a p-phenylene group, a m-phenylene group, a substituted-phenylene group, a p,p′-diphenylene sulfone group, a p,p′-biphenylene group, a p,p′-diphenylenecarbonyl group and a naphthylene group; wherein examples of a substitution group include C1 to C10 alkyl groups and phenyl groups.
In the Embodiment, a polyarylene sulfide may be a homopolymer having one kind of an arylene group as a structural unit, or a copolymer obtained by using a mixture of two or more different arylene groups from the viewpoint of processability or heat resistance. A favorable polyarylene sulfide is a polyphenylene sulfide, in which an arylene group is a phenylene group, and a polyphenylene sulfide having a recurring unit of p-phenylene sulfide as a main constituting element (hereinafter occasionally abbreviated simply as “PPS”) is preferable in view of its superior processability, heat resistance, and industrially easy availability.
In the Embodiment, examples of a production process of a polyarylene sulfide include a method for polymerizing a halogenated aromatic compound, such as p-dichlorobenzene, in the presence of sulfur and sodium carbonate; a method for polymerizing it in a polar solvent in the presence of sodium sulfide or sodium hydrogensulfide and sodium hydroxide, or hydrogen sulfide and sodium hydroxide or sodium aminoalkanoate; and a method for self-condensating p-chlorothiophenol; but a method for reacting sodium sulfide and p-dichlorobenzene in an amide solvent, such as N-methylpyrrolidone and dimethylacetamide, or a sulfone solvent, such as sulfolane, is applied favorably.
In the Embodiment, trichlorobenzene may be used as a branching agent according to need, in order to introduce a branch structure in a molecular chain of polyarylene sulfide.
In the Embodiment, there is no restriction on the production process of polyarylene sulfide, insofar as it should be a publicly known process. Processes disclosed in U.S. Pat. No. 2,513,188, Japanese Patent Publication No. 44-27671, Japanese Patent Publication No. 45-3368, Japanese Patent Publication No. 52-12240, Japanese Patent Application Laid-Open No. 61-225217, U.S. Pat. No. 3,274,165, Japanese Patent Publication No. 46-27255, Belgium Patent No. 29437 and Japanese Patent Application Laid-Open No. 05-222196, and the prior arts described in said patents may be exemplified.
In the Embodiment, a PPS produced by the above publicly known polymerization methods is usually a linear type PPS.
In the Embodiment, after polymerized to a linear type PPS, the same may be subjected to a heat treatment at a temperature below the melting point of the PPS (e.g. 200 to 250° C.) in the presence of oxygen to promote oxidative cross-linking, so that the polymer molecular weight and the viscosity are appropriately increased to obtain a cross-linked PPS. The cross-linked PPS includes a half cross-linked PPS, in which cross-linking is minimal.
Either or a mixture of both of a linear type PPS and a cross-linked PPS may be used as PPS. Mixed use of a linear type PPS and a cross-linked PPS is preferable in view of the effect of making small the particle size of a dispersed phase of polyphenylene ether.
In the Embodiment, to reduce pellet whitening or mold depositing on the occasion of molding attributable to PPS, it is preferable that the content of oligomers contained in PPS is 0.7% by mass or less with respect to PPS.
In the Embodiment, the oligomer contained in PPS means a substance extracted into a methylene chloride solution, when PPS is extracted by methylene chloride. Generally oligomers contained in PPS are a substance known as impurities of PPS, and the content of oligomers can be measured specifically according to the following method.
Into 80 mL of methylene chloride 5 g of PPS powder is added, and a Soxhlet extraction is conducted for 6 hours, then after cooling down to room temperature, a methylene chloride extract solution is transferred to a weighing bottle. Then the vessel used for the extraction is washed 3 times using total 60 mL of methylene chloride, and the washing liquid is recovered into the weighing bottle. Then, by heating to about 80° C. the methylene chloride in the weighing bottle is removed by evaporation, and the amount of the residue is weighed. From the residue amount an extracted amount by methylene chloride, namely the oligomer amount in PPS can be determined.
In the Embodiment, the melt viscosity of polyarylene sulfide at 300° C. under a shear rate of 100 sec−1 is preferably 10 to 150 Pa·s, more preferably 10 to 100 Pa·s, and further preferably 10 to 80 Pa·s.
If the melt viscosity of polyarylene sulfide at 300° C. under a shear rate of 100 sec−1 is 10 Pa·s or higher, the resin can have superior mechanical properties, and if it is 150 Pa·s or lower, impregnation of the resin into the long fiber filler is improved.
In the Embodiment, the melt viscosity of polyarylene sulfide at 300° C. under a shear rate of 100 sec−1 can be measured by a capillary rheometer. For example it can be measured at 300° C. under a shear rate of 100 sec−1 by Capirograph (Toyo Seiki Seisaku-sho, Ltd.) using a capillary of capillary length=10 mm and capillary diameter=1 mm.
In the Embodiment, polyarylate is a polymer having an aromatic ring and an ester bond in the structural unit, and called also as poly(aryl ester). As a polyarylate, a polyarylate having a recurring unit represented by the following formula (2), for example composed of bisphenol A and terephthalic acid and/or isophthalic acid, is preferably used.
In the Embodiment, a polyarylate containing terephthalic acid and isophthalic acid at a molar ratio of about 1:1 is preferable from the viewpoint of heat resistance of a molded article and toughness of the resin.
In the Embodiment, as a polyarylate a commercial product may be utilized, for example “U polymer” (Trade name of Unitika Ltd.) may be utilized.
As for molecular weight of a polyarylate, the number average molecular weight measured by gel permeation chromatography (GPC) and reduced to polystyrene is preferably 5,000 to 300,000, more preferably 10,000 to 300,000, and further preferably 10,000 to 100,000. If the number average molecular weight of a polyarylate is 5,000 or higher, heat resistance of a molded article is improved and mechanical strength of the resin tends to increase, and if it is 300,000 or lower, flowability of the resin is improved and the dispersion phase of polyether phenol tends to disperse in smaller size.
In the Embodiment, a specific measurement method of a number average molecular weight reduced to polystyrene is: a measured value by GPC using chloroform as a solvent, under a condition of a column temperature of 40° C., is fit to a detection time-molecular weight curve measured in advance for a standard polystyrene under the same conditions to obtain the reduced molecular weight. Thereby, the concentration of a polyarylate in the chloroform solution is 1 g/L. A detector is preferably a UV absorption detector measuring around 280 nm.
Polyethersulfone, polyetherimide and polysulfone to be used in the Embodiment may be selected appropriately from a group of publicly known amorphous super-engineering plastics.
Specific examples of a polyethersulfone product include Radel A, Radel R (Registered trade names of Solvay Advanced Polymers), Mitsui PES (Mitsui Chemicals), and Ultrason E (Registered trade name of BASF Japan Ltd.).
Specific examples of a polyetherimide product include Ultem (Registered trade name of SABIC Innovative Plastics).
Specific examples of a polysulfone product include Udel and Mindel (Registered trade names of Solvay Advanced Polymers) and Ultrason S (Registered trade name of BASF Japan Ltd.).
In the Embodiment, polyaryl ketone is a thermoplastic resin having aromatic rings, an ether bond and a ketone bond in the structural unit, and polyether ketone, polyetherether ketone and polyether ketone ketone can be exemplified.
In the Embodiment, a polyetherether ketone having a recurring unit represented by the following formula (3) is favorably used.
In the Embodiment, as a polyetherether ketone a commercial product may be utilized, examples thereof include PEEK 151G, PEEK 90G, PEEK 381G, PEEK 450G and PEK (Registered trade names of Victrex) and Ultrapek (PEKEKK) (Registered trade name of BASF); and PEEK (Registered trade names of Victrex) can be favorably utilized.
One type of polyaryl ketone, or two or more types in combination may be used.
In the Embodiment, as for the molecular weight of a polyaryl ketone, the melt viscosity may be used as an index, and the melt viscosity is preferably in a range of 50 to 5,000 Pa·s (500 to 50,000 Poise), more preferably 70 to 3,000 Pa·s, further preferably 100 to 2,500 Pa·s, and still further preferably 200 to 1,000 Pa·s.
If the melt viscosity of a polyaryl ketone is 50 Pa·s or higher, the mechanical strength of the resin tends to be improved, and if it is 5,000 Pa·s or lower, the moldability of the resin tends to be improved.
In the Embodiment, the melt viscosity of a polyaryl ketone is an apparent melt viscosity measured by extruding the polyaryl ketone heated to 400° C. through a nozzle with inner diameter of 1 mm and length of 10 mm under a load of 100 kg.
In the Embodiment, if as a thermoplastic resin other than polyphenylene ether a resin with considerably low affinity with polyphenylene ether, such as one or more selected from the group consisting of an olefinic resin, polyester, polyamide, polyarylene sulfide, polyetherimide, polyethersulfone, polysulfone and polyaryl ketone, is used, a compatibilizer between a polyphenylene ether and a thermoplastic resin other than polyphenylene ether should be preferably used.
In case a thermoplastic resin other than polyphenylene ether is an olefinic resin, a compatibilizer is preferably used, because polyphenylene ether and an olefinic resin are in principle incompatible. A thermoplastic resin blend of an olefinic resin and polyphenylene ether is so structured that in a continuous phase of an olefinic resin polyphenylene ether is dispersed playing an important role in fortifying the heat resistance of the amorphous part of the olefinic resin beyond the glass transition temperature.
In order to improve the compatibility between them, a copolymer having a chain segment with high compatibility with an olefinic resin and a chain segment with high compatibility with polyphenylene ether can be used as a compatibilizer. As a copolymer with such compatibilities a copolymer with polystyrene chain-polyolefin chain may be exemplified.
In the Embodiment, examples of a compatibilizer between an olefinic resin and polyphenylene ether include a copolymer having a polyphenylene ether chain-polyolefin chain, and a hydrogenated block copolymer prepared by hydrogenating a block copolymer having at least 2 polymer blocks A composed mainly of an aromatic vinyl compound and at least 1 polymer block B composed mainly of a conjugated diene compound, but a hydrogenated block copolymer is preferable.
Examples of a hydrogenated block copolymer as a compatibilizer between an olefinic resin and polyphenylene ether include hydrogenated block copolymers produced by hydrogenating block copolymers having structures of A-B-A, A-B-A-B, (A-B—)4—Si and A-B-A-B-A. Thereby A means a polymer block composed mainly of an aromatic vinyl compound, and B means a polymer block composed mainly of a conjugated diene compound.
The content of an aromatic vinyl compound in a polymer block A and the content of a conjugated diene compound in a polymer block B are preferably at least 70% by mass respectively.
A preferable hydrogenated block copolymer is a block copolymer produced by hydrogenating the olefinic unsaturated bonds originated from a conjugated diene compound in a block copolymer composed of an aromatic vinyl compound and a conjugated diene compound, to be decreased to 50% or lower, preferably to 30% or lower, and more preferably to 10% or lower.
In the Embodiment, a block copolymer useful as a compatibilizer between an olefinic resin and polyphenylene ether is same as a block copolymer for an impact modifier as is described hereinbelow, and in case an olefinic resin is used as a thermoplastic resin other than polyphenylene ether, the block copolymer has both functions of a function for a compatibilizer and a function for an impact modifier. Among the block copolymers for an impact modifier described below, a so-called high vinyl type block copolymer, in which 1,2-vinyl bond rate of a polybutadiene segment, namely a conjugate diene compound segment, is 50% to 90%, can be used also favorably as a compatibilizer between polyphenylene ether and an olefinic resin.
If polyester is a thermoplastic resin other than polyphenylene ether, examples of a preferable compatibilizer include compounds having an epoxy group, an oxazolyl group, an imide group, a carboxylic acid group and an acid anhydride group; and a compound having an epoxy group is more preferable.
Specific examples include glycidyl methacrylate/styrene copolymer, glycidyl methacrylate/styrene/methyl methacrylate copolymer, glycidyl methacrylate/styrene/methyl methacrylate/methacrylate copolymer, glycidyl methacrylate/styrene/acrylonitrile copolymer, vinyloxazoline/styrene copolymer, N-phenylmaleimide/styrene copolymer, N-phenylmaleimide/styrene/maleic anhydride copolymer and styrene/maleic anhydride copolymer. Further, a graft copolymer such as a graft copolymer of ethylene/glycidyl methacrylate copolymer and polystyrene may be also used.
In the Embodiment, as a compatibilizer between polyester and polyphenylene ether, glycidyl methacrylate/styrene copolymer, vinyloxazoline/styrene copolymer, N-phenylmaleimide/styrene copolymer and N-phenylmaleimide/styrene/maleic anhydride copolymer are preferable, and glycidyl methacrylate/styrene copolymer is more preferable.
Although there is no particular restriction on the ratio of a compound, which is a monomer in the copolymers, having one or more functional groups selected among an epoxy group, an oxazolyl group, an imide group, a carboxylic acid group and an acid anhydride group to a styrenic compound, but from the viewpoint of silver streaking at injection molding or die deposit at extruding, a compound having one or more functional groups selected among an epoxy group, an oxazolyl group, an imide group, a carboxylic acid group and an acid anhydride group is preferably 50% by mass or less.
In the Embodiment, the addition amount of a compatibilizer between polyester and polyphenylene ether, based on 100 parts by mass of polyphenylene ether plus liquid crystal polyester, is preferably 0.1 parts by mass or more from the viewpoint of the tensile strength of the pellet, and preferably 10 parts by mass or less from the viewpoint of the flame retardancy of the pellet, more preferably from 1 to 7 parts by mass, and further preferably from 3.5 to 6 parts by mass.
Although there is no particular restriction on the addition method of a compatibilizer, preferably it should be added together with polyphenylene ether, or its masterbatch, which is produced in advance by melt-blending with polyester, should be added with polyphenylene ether.
Thereby it is required that polyphenylene ether constitutes a dispersed phase, and polyester constitutes a continuous phase. By the continuous phase constituted by polyester, chemical resistance of the pellet and rigidity of the resin become superior. The dispersion morphology can be judged easily by observation under, for example, a transmission microscope. A preferable particle size of the dispersed polyphenylene ether is 40 μm or less, and more preferably 20 μm or less.
In the Embodiment, in case an impact improver described below is added, the impact improver should preferably exist in the polyphenylene ether dispersed phase. It is also useful for the thermoplastic resin blend of the Embodiment to form a sea/island/lake structure, in which polyester exists also in the dispersed phase of the polyphenylene ether phase, by selecting a production process. An example of a specific production process for forming a sea/island/lake structure is that, using an extruder with more than one feeding ports at different extruder zones, polyphenylene ether, a part of liquid crystal polyester and according to need a compatibilizer therefor are fed to the initial extruder feeding port, and the rest of the liquid crystal polyester is fed to a downstream feeding port of the extruder.
In case a thermoplastic resin other than polyphenylene ether is polyamide, examples of a compatibilizer include the compatibilizers disclosed precisely in Japanese Patent Application Laid-Open No. 08-48869 and Japanese Patent Application Laid-Open No. 09-124926. All of those disclosed compatibilizers can be used, and a combined use is also possible.
In the Embodiment, among said compatibilizers, maleic acid or derivatives thereof, citric acid or derivatives thereof, and fumaric acid or derivatives thereof are preferable.
In the Embodiment, the content of the compatibilizer is, based on 100 parts by mass of a mixture of polyamide and polyphenylene ether, preferably from 0.01 to 25 parts by mass, more preferably from 0.05 to 10 parts by mass, and further preferably from 0.1 to 5 parts by mass.
In the Embodiment, polyphenylene ether particles exist dispersed in the continuous phase of polyamide preferably with the average particle size from 0.1 to 5 μm, more preferably with the average particle size from 0.3 to 3 μm, and further preferably from 0.5 to 2 μm.
In the Embodiment, an impact improver described below preferably exists in the dispersed phase of polyphenylene ether.
In case a thermoplastic resin other than polyphenylene ether is polyarylene sulfide, a thermoplastic resin blend composed of polyarylene sulfide and polyphenylene ether is preferably so constituted that polyphenylene ether is dispersed in a matrix of polyarylene sulfide, and polyphenylene ether takes advantage of its high glass transition temperature and plays an important role in supporting the heat resistance beyond the glass transition temperature of the amorphous part of polyarylene sulfide.
Polyarylene sulfide and polyphenylene ether are incompatible, and to improve the compatibility, a copolymer of compounds containing an epoxy group and/or an oxazolyl group is useful.
In the Embodiment, by adding a compatibilizer, generation of a flash on a molded article molded with the pellet can be remarkably reduced.
In case such effect is not required, a compatibilizer may be unnecessary.
In the Embodiment, as a compatibilizer between polyarylene sulfide and polyphenylene ether, a copolymer of an unsaturated monomer having an epoxy group and/or an oxazolyl group and a monomer with main constituent of styrene can be favorably used.
A monomer with main constituent of styrene means a monomer component containing 65% by mass or more, more preferably from 75 to 95% by mass, of styrene and a monomer copolymerizable with styrene. Examples include a copolymer of an unsaturated monomer having an epoxy group and/or an unsaturated monomer having an oxazolyl group and styrene, and a copolymer of an unsaturated monomer having an epoxy group and/or an unsaturated monomer having an oxazolyl group and styrene/acrylonitrile (=90 to 75% by mass/10 to 25% by mass).
Examples of the unsaturated monomer having an epoxy group include glycidyl methacrylate, glycidyl acrylate, vinylglycidyl ether, glycidyl ether of hydroxyalkyl (meth)acrylate, glycidyl ether of polyalkylene glycol(meth)acrylate and glycidyl itaconate; and glycidyl methacrylate is preferable.
As the unsaturated monomer having an oxazolyl group, a vinyloxazoline compound may be exemplified, and, for example, 2-isopropenyl-2-oxazoline can be industrially available and favorably utilized.
Examples of other monomers to be copolymerized with the unsaturated monomer having an epoxy group and/or an oxazolyl group include styrene and additionally as a copolymer component a vinyl cyanide monomer such as acrylonitrile, vinyl acetate, and (meth)acrylic acid ester.
It is preferable to contain in the copolymer from 0.3 to 20% by mass of a structural unit of an unsaturated monomer having an epoxy group and/or an unsaturated monomer having an oxazolyl group, more preferable to contain from 1 to 15% by mass, and further preferable to contain from 3 to 10% by mass.
By using the compatibilizer containing from 0.3 to 20% by mass of an unsaturated monomer having an epoxy group and/or an unsaturated monomer having an oxazolyl group, the compatibility between polyarylene sulfide and polyphenylene ether can be maintained high, and generation of a flash on a molded article molded with the obtained pellet can be remarkably reduced. Further, the balance between heat resistance as well as toughness (impact strength) and mechanical strength is positively influenced.
Examples of the copolymer include styrene/glycidyl methacrylate copolymer, styrene/glycidyl methacrylate/methyl methacrylate copolymer, styrene/glycidyl methacrylate/acrylonitrile copolymer, styrene/vinyloxazoline copolymer and styrene/vinyloxazoline/acrylonitrile copolymer.
In the Embodiment, the content of a compatibilizer is, based on 100 parts by mass of the total amount of polyphenylene ether plus polyarylene sulfide, preferably from 0.5 to 5 parts by mass, more preferably from 1 to 5 parts by mass, and further preferably from 1 to 3 parts by mass.
If the content of a compatibilizer is 0.5 parts by mass or higher, the compatibility between polyarylene sulfide and polyphenylene ether becomes well, and if it is 5 parts by mass or lower, the average particle size of polyphenylene ether forming a dispersed phase becomes 10 μm or less, which can reduce remarkably generation of a flash on a molded article molded with the obtained pellet, and influence positively the balance between heat resistance (impact strength) as well as toughness and mechanical strength. In case the compatibilizer is not used, a molded article with high heat resistance and impact resistance is obtained.
Thereby polyphenylene ether particles preferably exist dispersed in the continuous phase of polyarylene sulfide with the average particle size of 10 μm or less, more preferably 8 μm or less, and further preferably 5 μm or less. It is effective to keep the average size of the dispersed particles at 10 μm or less for preventing deterioration of appearance and detachment phenomenon of the obtained pellet. Further, it is preferable that an impact improver described below should exist in the dispersed phase of polyphenylene ether.
In case a thermoplastic resin other than polyphenylene ether is a thermosetting resin of polyarylate, polyetherimide, polyethersulfone, polysulfone and polyaryl ketone, as a compatibilizer all of the compatibilizers described above with respect to polypropylene, polyamide, polyarylene sulfide and polyester with polyphenylene ether can be used. Since said resins have in general high processing temperatures and therefore most of the terminal functional groups are inactivated to a reaction, it is preferable to use an appropriately selected compatibilizer after causing some kind of chemical reaction (e.g. a scission reaction of a molecular chain by heat or a peroxide).
Without such a reaction, compatibilization is also possible. More particularly, addition of a small amount of polyarylate as compatibilizer between polyphenylene ether and polyaryl ketone is very useful to enhance the compatibility between them.
In the Embodiment, as a compatibilizer between polyphenylene ether and a thermoplastic resin other than polyphenylene ether an inorganic metal oxide can be also used. Examples thereof include oxides of one or more metals selected from the group consisting of zinc, titanium, calcium, magnesium and silicon; and among them zinc oxide is preferable.
In the Embodiment, for stabilization of polyphenylene ether and/or a thermoplastic resin other than polyphenylene ether, various publicly known stabilizers can be favorably used.
Examples of a stabilizer include metallic stabilizers, such as zinc oxide and zinc sulfide; antioxidants such as a sterically-hindered phenol based antioxidant, a phosphorus based thermal stabilizer and a sulfur based thermal stabilizer; and organic stabilizers, such as a sterically-hindered amine based photo stabilizer and a benzotriazole based UV absorber.
A preferable content of the stabilizer is from 0.1 to 5 parts by mass based on 100 parts by mass of the thermoplastic resin blend.
In the Embodiment, a sterically-hindered phenol based antioxidant is preferable as a stabilizer.
Specific examples include Irganox 1098 (Registered trade name) and Irganox 1076 (Registered trade name) available from Ciba Specialty Chemicals Ltd.
In the Embodiment, although the step of impregnating the long fiber filler with the thermoplastic resin blend is vulnerable to an atmospheric oxygen, by addition of a sterically-hindered phenol based antioxidant the discoloration of the obtained pellet can be prevented.
In the Embodiment, the content of the sterically-hindered phenol based antioxidant is preferably 0.1 parts by mass or higher based on 100 parts by mass of the thermoplastic resin blend, more preferably 0.2 parts by mass or higher, and further preferably 0.3 parts by mass or higher. Further, the content of the sterically-hindered phenol based antioxidant is preferably 5 parts by mass or lower, more preferably 3 parts by mass or lower, and further preferably 2 parts by mass or lower.
In the Embodiment, an organic and inorganic flame retardant may be added in order to give a flame retarding property. Examples of a flame retardant include a halogen-containing compound, an antimony compound, a phosphorus based flame retardant, a cyclic nitrogen-containing compound, a silicon compound and a metal hydroxide. Among them, a phosphorus based flame retardant, a cyclic nitrogen-containing compound and a silicon compound are preferable in view of flame retardancy as well as density lowering property.
Examples of a phosphorus based flame retardant include red phosphorus, an organophosphate compound, a phosphazene compound, phosphinic acid salts, phosphonic acid salts and a phosphoramide compound.
Examples of an organophosphate compound include triphenyl phosphate, phenyl bis(dodecyl)phosphate, phenyl bis(neopentyl) phosphate, phenyl bis(3,5,5′-trimethylhexyl) phosphate, ethyl diphenyl phosphate, 2-ethylhexyl di(p-tolyl) phosphate, bis(2-ethylhexyl)p-tolyl phosphate, tritolyl phosphate, bis(2-ethylhexyl) phenyl phosphate, tris(nonylphenyl)phosphate, didodecyl p-tolyl phosphate, tricresyl phosphate, dibutyl phenyl phosphate, 2-chloroethyl diphenyl phosphate, p-tolyl bis(2,5,5′-trimethylhexyl) phosphate, 2-ethylhexyl diphenyl phosphate, bisphenol A bis(diphenyl phosphate), diphenyl(3-hydroxyphenyl) phosphate, bisphenol A bis(dicresyl phosphate), resorcinol bis(diphenyl phosphate), resorcinol bis(dixylenyl phosphate), 2-naphthyl diphenyl phosphate, 1-naphthyl diphenyl phosphate and di(2-naphthyl)phenyl phosphate.
Examples of an organophosphate compound further include aromatic condensation phosphate compounds represented by the following formula (4) or (5).
wherein Q1, Q2, Q3 and Q4 independently represent a C1 to C6 alkyl group, R1 and R2 represent a methyl group, and R3 and R4 independently represent a hydrogen atom or a methyl group. The n represents an integer of 1 or larger, n1 and n2 independently represent integers from 0 to 2, and the m1, m2, m3 and m4 independently represent an integer from 1 to 3.
An aromatic condensation phosphate compound is in general a mixture, in which the compounds with n representing integers 1 to 3 occupy 90% or more, and available as a mixture further containing multimers with n higher than 3 and other byproducts.
Examples include a bisphenol A based aromatic condensation phosphate, such as a phosphate compound containing bisphenol A bis(diphenyl phosphate) as a main component (CR741, Daihachi Chemical Ind.) and a phosphate compound containing bisphenol A bis(dixylenyl phosphate) as a main component; and a resorcin based aromatic condensation phosphate, such as a phosphate compound containing resorcinol bis(dixylenyl phosphate) as a main component (PX200, Daihachi Chemical Ind.) and a phosphate compound containing resorcinol bis(diphenyl phosphate) as a main component (CR?733S, Daihachi Chemical Ind.). A resorcin based and a bisphenol A based aromatic phosphate compound are preferable in terms of volatility and heat resistance, and a resorcin based and a bisphenol A based aromatic condensation phosphate compound with the acid value of 0.5 or lower, preferably 0.1 or lower, are more preferable in terms of water resistance and electrical properties, and a bisphenol A based aromatic condensation phosphate compound is further preferable.
As a phosphazene compound, compounds having a cyclic or linear structure represented by the following formula (6) are exemplified, but a compound with a cyclic structure is preferable. A phenoxy phosphazene compound with a 6-membered or 8-membered ring, where n=3 or 4, is more preferable.
wherein R represent independently a C1 to C20 aliphatic or aromatic group, the n represents 3 or a larger integer.
The compound may be cross-linked by a cross-linking group selected from the group consisting of a phenylene group, a biphenylene group and a group represented by the following formula (7).
wherein X represents —C(CH3)2—, —SO2—, —S— or —O—.
The phosphazene compound represented by the formula (6) is a publicly known compound, and described, for example, in “Inorganic Polymers” (Pretice-Hall International, Inc.), by James E. Mark, Harry R. Allcock, Robert West, 1992, p 61-p 140. Synthesis example to prepare such phosphazene compounds are disclosed in Japanese Patent Publication No. 03-73590, Japanese Patent Application Laid-Open No. 09-71708, Japanese Patent Application Laid-Open No. 09-183864, Japanese Patent Application Laid-Open No. 11-181429, etc. For example, in case of synthesis of an uncrosslinked cyclic phenoxy phosphazene compound, according to the method described in “Phosphorus Nitrogen Compounds”, (Academic Press), by H. R. Allcock (1972), a toluene solution of sodium phenolate is added dropwise with stirring into 580 g of a 20% chlorobenzene solution containing 1.0 unit mol (115.9 g) of dichlorophosphazene oligomer (a mixture of trimer 62% and tetramer 38%), and the mixture is left reacting at 110° C. for 4 hours to obtain, after purification, the uncrosslinked cyclic phenoxy phosphazene compound.
Since a phosphazene compound contains a higher content of phosphorus in the compound than in an ordinary phosphate compound, addition of a small amount can assure sufficient flame retardancy. Further, owing to its superior hydrolysis resistance and thermolysis resistance, the deterioration of physical properties of a thermosetting resin composition can be decreased. Consequently, a phosphazene compound is a preferable compound as a phosphorus based flame retardant, and a phosphazene compound with the acid value of 0.5 or lower is more preferable in view of flame retardancy as well as water resistance and electrical properties.
Phosphinic acid salts include a phosphinate by the formula (8) or (9), and/or a diphosphinate and/or a condensation product thereof (hereinafter occasionally abbreviated simply as “phosphinic acid salt”).
wherein R1 and R2, the same or different, represent linear or branched C1 to C6 alkyl and/or aryl or phenyl, R3 represents linear or branched C1 to C10 alkylene, C6 to C10 arylene, C6 to C10 alkylarylene or C6 to C10 arylalkylene, M represents one or more selected among calcium (ion), magnesium (ion), aluminum (ion), zinc (ion), bismuth (ion), manganese (ion), sodium (ion), potassium (ion) and a protonated nitrogen base, m is 2 or 3, n represents an integer of 1 to 3 and x is 1 or 2.
The phosphinic acid salts in the Embodiment can be produced by a publicly known process as disclosed in European Patent Application Laid-Open No. 699708, Japanese Patent Application Laid-Open No. 08-73720. For example, a phosphinate can be produced by reacting phosphinic acid in an aqueous solution with a metal carbonate, a metal hydroxide or a metal oxide, but not limited thereto. It can be produce also by a sol-gel process, etc. The phosphinic acid salts are generally monomeric compounds, but under certain circumstances depending on reaction conditions, it may contain polymeric phosphinic acid salts, which are condensation products with the degree of condensation of 1 to 3.
In the Embodiment, examples of a phosphinic acid include dimethylphosphinic acid, ethylmethylphosphinic acid, diethylphosphinic acid, methyl-n-propylphosphinic acid, methane-di(methylphosphinic acid), benzene-1,4-(dimethylphosphinic acid), methylphenylphosphinic acid, diphenylphosphinic acid and a mixture thereof.
As a metal component one or more selected among calcium ion, magnesium ion, aluminum ion, zinc ion, bismuth ion, manganese ion, sodium ion, potassium ion and/or a protonated nitrogen base can be exemplified, and one or more selected among calcium ion, magnesium ion, aluminum ion and zinc ion are preferable.
Examples of the phosphinic acid salts include calcium dimethylphosphinate, magnesium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, magnesium ethylmethylphosphinate, aluminum ethylmethylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, magnesium diethylphosphinate, aluminum diethylphosphinate, zinc diethylphosphinate, calcium methyl-n-propylphosphinate, magnesium methyl-n-propylphosphinate, aluminum methyl-n-propylphosphinate, zinc methyl-n-propylphosphinate, calcium methane-di(methylphosphinate), magnesium methane-di(methylphosphinate), aluminum methane-di(methylphosphinate), zinc methane-di(methylphosphinate), calcium benzene-1,4-(dimethylphosphinate), magnesium benzene-1,4-(dimethylphosphinate), aluminum benzene-1,4-(dimethylphosphinate), zinc benzene-1,4-(dimethylphosphinate), calcium methylphenylphosphinate, magnesium methylphenylphosphinate, aluminum methylphenylphosphinate, zinc methylphenylphosphinate, calcium diphenylphosphinate, magnesium diphenylphosphinate, aluminum diphenylphosphinate and zinc diphenylphosphinate.
In the Embodiment, as phosphinic acid salts are preferable from the viewpoint of flame retardancy and suppression of mold deposit, calcium dimethylphosphinate, aluminum dimethylphosphinate, zinc dimethylphosphinate, calcium ethylmethylphosphinate, aluminum ethylmethylphosphinate, zinc ethylmethylphosphinate, calcium diethylphosphinate, aluminum diethylphosphinate and zinc diethylphosphinate, and among them aluminum diethylphosphinate is more preferable.
In the Embodiment, from the view point of mechanical strength and article appearance of a molded article to be obtained by molding the pellet, the average particle size (d50%) of a phosphinic acid salt is preferably 0.5 μm or larger, more preferably 1.0 μm or larger, and further preferably 2 μm or larger. Further, the average particle size of the phosphinic acid salts is preferably 40 μm or less, more preferably 20 μm, further preferably 15 μm or less, and still further preferably 10 μm or less.
In the Embodiment, if the number average particle size of a phosphinic acid salt is 0.5 μm or larger, at fabrication such as melt blending, handling property and feeding property into an extruder are improved and favorable quality resin can be obtained. Further, if the average particle size of the phosphinic acid salt is 40 μm or less, it exerts such effects that high mechanical strength of a molded article becomes easily attainable and the surface appearance of the molded article becomes improved.
Concerning the particle size distribution of a phosphinic acid salt, the ratio (d75%/d25%) of the particle size at 75% of the order counted from the small side (d75%) to the particle size at 25% (d25%) is preferably larger than 1.0 and equal to or less than 5.0, more preferably from 1.2 to 4.0, and further preferably from 1.5 to 3.0. By using a phosphinic acid salt with the d75%/d25% value beyond 1.0 but not more than 5.0, the surface impact strength of a molded article can be remarkably improved.
In the Embodiment, the average particle size (d50%) and the particle size distribution are based on the particle sizes related to volume measured by a laser diffraction/scattering particle size distribution analyzer. The measurement is conducted using a 3% aqueous solution of isopropanol as a dispersing medium for the phosphinic acid salts. More specifically, a measurement can be conducted using a laser diffraction/scattering particle size distribution analyzer LA-910 (Horiba, Ltd.) by: first carrying out a blank test with only a dispersing medium of a 3% aqueous solution of isopropanol, and then conducting a measurement after adding a test sample to satisfy the specified transmission rate (from 95% to 70%). Thereby dispersion of a test sample in the dispersing medium is carried out by sonication for 1 min.
Unreacted materials or byproducts may remain in the phosphinic acid salts of the Embodiment to the extent that the effect of the Embodiment should not be impaired.
In the Embodiment, two or more types of the phosphorus based flame retardants may be used in combination.
In the Embodiment, the content of the phosphorus based flame retardant is preferably from 1 to 50 parts by mass based on 100 parts by mass of the thermoplastic resin blend, more preferably from 1 to 40 parts by mass, further preferably from 2 to 30 parts by mass, and still further preferably 3 to 25 parts by mass.
If the content of the phosphorus based flame retardant is 3 parts by mass or higher based on 100 parts by mass of the thermoplastic resin blend, the flame retardancy of the pellet becomes good. Further, if it is 40 parts by mass or lower, mechanical strength and thermal form stability of a molded article are good.
Examples of the silicon compound include silicone, a silsesquioxane cage or a partially cleaved structure thereof and silica.
Silicone means an organosiloxane polymer, which may have a linear structure, a cross-linked structure or a structure mixed of them in certain ratio. It may be used singly or as a mixture among them, however from the viewpoint of flame retardancy and flowability, that having a linear structure is preferable. From the viewpoint of flame retardancy and impact strength, a silicone having a functional group in a molecule as a terminal group or a side chain group is preferable. As a functional group, an epoxy group and an amino group are preferable.
Specifically, silicone fluid, modified silicone fluid and silicone powder produced by Dow Corning Toray Silicone Co., Ltd. and straight silicone fluid, reactive silicone fluid, non-reactive silicone fluid and KMP series silicone powder produced by Shin-Etsu Chemical Co., Ltd., etc. can be used. Either of a fluid type and a solid type may be used.
The viscosity at 25° C. of a fluid type is preferably 10 to 10,000 mm2/s, more preferably 100 to 8,000 mm2/s, and further preferably 500 to 3,000 mm2/s.
The average particle size of a solid type is preferably 0.1 to 100 μm, more preferably 0.5 to 30 μm, and further preferably 0.5 to 5 μm.
In the Embodiment, the added content of a silicone is in view of a flame retardant effect preferably 0.1 parts by mass or more based on 100 parts by mass of the thermoplastic resin blend, and in view of suppression of rigidity decrease preferably 10 parts by mass or less. More favorably the lower limit is 0.3 parts by mass, and further preferably 0.5 parts by mass. More favorably the upper limit is 5 parts by mass, and further preferably 2 parts by mass.
The cyclic nitrogen-containing compound is a cyclic organic compound containing a nitrogen element. Specifically, melamine derivatives, such as melamine, melem and melon, can be used favorably, and from the viewpoint of volatility melem and melon are preferable.
The added content of a cyclic nitrogen-containing compound is in view of a flame retardant effect preferably 0.1 parts by mass or more based on 100 parts by mass of the thermoplastic resin blend, and in view of suppression of rigidity decrease preferably 10 parts by mass or less. More favorably the lower limit is 0.3 parts by mass, and further preferably 0.5 parts by mass. More favorably the upper limit is 5 parts by mass, and further preferably 2 parts by mass.
(Filler Other than Long Fiber Filler)
In the Embodiment, the pellet may further contain according to need a filler other than the long fiber filler, such as a fibrous filler with the fiber length of 3 mm or less, and a granular filler with the particle size of 1 mm or less. As a fibrous filler with the fiber length of 3 mm or less, one or more selected from carbon fiber, glass fiber, metal fiber and aramid fiber can be exemplified, and one or more selected from carbon fiber and glass fiber are preferable. More preferable is glass fiber.
In this connection, the fiber length of the fibrous filler with the fiber length less than 3 mm is not counted in the calculation of the average fiber length of the long fiber filler of the Embodiment.
Examples of a granular filler with the particle size of 1 mm or less include a hydroxide of an element selected from magnesium and calcium; an oxide of an element selected from the group consisting of magnesium, titanium, iron, copper, zinc and aluminum; and one or more fillers selected from the group consisting of zinc sulfide, zinc borate, calcium carbonate, talc, wollastonite, glass, carbon black, carbon nanotube and silica. Among them a hydroxide of an element selected from magnesium and calcium; an oxide of an element selected from the group consisting of magnesium, titanium and zinc; zinc sulfide, zinc borate, calcium carbonate, talc, wollastonite, glass, carbon black and carbon nanotube are preferable; and a hydroxide of calcium, an oxide of an element selected from titanium and zinc; zinc sulfide, calcium carbonate, talc, wollastonite and carbon black are more preferable.
Concerning the added content of a filler other than the long fiber filler, it should be added in the long fiber filler reinforced resin pellet preferably at 20% by mass or less, preferably at 15% by mass or less, and preferably at 10% by mass or less. There is no particular restriction on the lower limit of the added content of a filler other than the long fiber filler, and the minimum quantity required to express the intended effect by addition should be added. If nucleating effect is expected, the added content of a filler other than the long fiber filler is preferably 0.01% by mass or higher, more preferably 0.05% by mass or higher, and further preferably 0.1% by mass or higher. If an effect on the dimensional stability is expected, an indicative minimum content is preferably 0.5% by mass or higher, more preferably 1% by mass or higher, and further preferably 5% by mass or higher.
In the Embodiment, wollastonite is obtained by purifying, crushing and classifying a natural mineral with a component of calcium silicate. An artificially synthesized product can be also used. As for the size of wollastonite, that with the average particle size from 2 to 9 μm and the aspect ratio of 5 or higher is preferable, more preferable is that with the average particle size from 3 to 7 μm and the aspect ratio of 5 or higher, and further preferable is that with the average particle size from 3 to 7 μm and the aspect ratio of 8 or higher and 30 or lower.
In the Embodiment, talc obtained by purifying, crushing and classifying a natural mineral with a component of magnesium silicate can be favorably used, and the crystallite diameter on the (002) diffraction plane of talc by wide-angle X-ray diffraction is preferably 570 Å or more.
The (002) diffraction plane of talc can be confirmed by identifying the existence of talc [Mg3Si4O10(OH)2] using a wide-angle X-ray diffraction apparatus, and verifying that an interlayer distance thereof is identical with the lattice spacing of the (002) diffraction plane of talc of about 9.39 Å. The crystallite diameter on the (002) diffraction plane of talc is calculated from the half-width of the peak thereof.
As for morphology of talc, the average particle size is preferably in a range from 1 to 20 μm, and the particle size distribution, in which the ratio (d75%/d25%) of the particle size at 75% of the order counted from the small side (d75%) to the particle size at 25% (d25%) is in a range from 1.0 to 2.5, is preferable. The ratio (d75%/d25%) is more preferably in a range from 1.5 to 2.2, and the average particle size is more preferably from 1 to 16 μm, and further preferably from 3 to 9 μm.
In the Embodiment, the average particle size and the particle size distribution of talc are based on the particle sizes related to volume measured by a laser diffraction/scattering particle size distribution analyzer. Further, they are the values measured using ethanol as a dispersing medium for talc.
In the Embodiment, as an oxide of an element selected from titanium and zinc are exemplified titanium dioxide and zinc oxide, and titanium dioxide is preferable.
Titanium dioxide may be a treated titanium dioxide, which surface is treated with alumina, a silicon compound and/or polysiloxane, and the content of titanium dioxide is preferably in a range from 90 to 99% by mass, and more preferably in a range from 93 to 98% by mass. In this case the surface treatment agent is not counted in the amount of the titanium dioxide.
The average particle size of the titanium dioxide is preferably in a range from 0.05 to 1 μm, more preferably in a range from 0.1 to 0.5 μm, and further preferably in a range from 0.2 to 0.4 μm.
In the Embodiment, the average particle size is a value measured by a centrifugal sedimentation method and means a weight median diameter. Thereby a solvent to disperse the granular filler should be appropriately selected depending upon a type of the granular filler, and for example in case of titanium dioxide a solution of sodium hexametaphosphate is preferably used.
In the Embodiment, various additives other than those described above may be added according to need. Additives generally added to compositions of plastics and rubber-like polymers maybe used without particular restrictions. Examples of additives include the additives described in “Additive Chemicals for Rubbers and Plastics (Gomu-Purasuchikku Haigou Yakuhin)” (Polymer Digest Co., Ltd.). Specific examples include a naphthenic, paraffinic, aromatic process oil to be used as a rubber softener, a plasticizer, such as fatty acid esters, aliphatic dibasic acid esters, phthalates and an epoxidized soybean oil, pigments such as iron oxides, a lubricant, such as stearic acid, behenic acid, zinc stearate, calcium stearate, magnesium stearate and ethylene bis-stearyl amide, a mold release agent, an organic polysiloxane, a flame retardant assistant, an antistatic agent and a colorant. The mixture of two or more of the additives may be used.
The long fiber filler reinforced resin pellet of the Embodiment is a pellet composed of the long fiber filler and the thermoplastic resin blend.
In the Embodiment, the average length of the long fiber filler reinforced resin pellet is preferably 3 mm or longer, more preferably 5 mm or longer, and further preferably 8 mm or longer. Further, the average length of the long fiber filler reinforced resin pellet is preferably 50 mm or shorter, more preferably 40 mm or shorter, and further preferably 15 mm or shorter.
In order not to deteriorate the impact strength of a molded article molded from the long fiber filler reinforced resin pellet of the Embodiment, the average length is preferably 3 mm or longer, and in order not to deteriorate the feeding property to an extruder, the average length is preferably 50 mm or shorter.
In the Embodiment, the average length of the pellet is the value determined by averaging all the pellet lengths measured by calipers for 50 pellets sampled arbitrarily.
In the Embodiment, the average diameter of the long fiber filler reinforced resin pellet is preferably 0.5 mm or larger, more preferably 1 mm or larger, and further preferably 2 mm or larger. Further, the average diameter of the long fiber filler reinforced resin pellet is preferably 8 mm or less, more preferably 5 mm or less, and further preferably 4 mm or less.
The average diameter of the pellet is the value determined by averaging the maximum diameter (in case of an ellipse the major diameter) and the minimum diameter (in case of an ellipse the minor diameter) measured by calipers for each of 50 pellets sampled arbitrarily to obtain a mean value, and averaging the diameter mean values of all the pellets.
In the Embodiment, the long fiber filler reinforced resin pellet may be used also as a resin pellet blend, in which from 0.1 to 150 parts by mass of a resin pellet without a long fiber filler are added based on 100 parts by mass of the long fiber filler reinforced resin pellet.
The content of the resin pellet without a long fiber filler is 0.5 parts by mass or more based on 100 parts by mass of the long fiber filler reinforced resin pellet, preferably 1 part by mass or more, and more preferably 2 parts by mass or more. Further, the content of the resin pellet without a long fiber filler is 120 parts by mass or less, preferably 100 parts by mass or less, and more preferably 80 parts by mass or less.
In order not to decrease the impact resistance of a molded article made of a resin pellet blend, the content should preferably not exceed the upper limit, and in case a color master batch is used as a resin pellet without a long fiber filler the content should be preferably not less than the lower limit in order to maintain the easiness of coloring.
In the Embodiment, the content of the long fiber filler in the resin pellet blend is preferably 10% by mass or more of the total amount of the resin pellet blend, more preferably 15% by mass or more, further preferably 20% by mass or more, and still further preferably 25% by mass or more. Further, the content of the long fiber filler in the resin pellet blend is preferably 60% by mass or less, more preferably 55% by mass or less, and further preferably 50% by mass or less.
In order not to decrease the impact strength of a molded article molded from the resin pellet blend, the content is preferably 10% by mass or more, and from the viewpoint of limiting the molding temperature, it is preferably 60% by mass or less.
In the Embodiment, a resin pellet without a long fiber filler may further contain a filler other than the long fiber filler, and as a filler other than the long fiber filler, a granular filler may be exemplified.
Examples of a granular filler include a hydroxide of an element selected from magnesium and calcium, an oxide of an element selected from the group consisting of magnesium, titanium, iron, copper, zinc and aluminum, and one or more fillers selected from the group consisting of zinc sulfide, zinc borate, calcium carbonate, talc, wollastonite, glass, carbon black, carbon nanotube and silica.
The average particle size of a granular filler is preferably 1 mm or less, and specifically those granular fillers exemplified as usable for the long fiber filler reinforced resin pellet may be exemplified.
The content of a granular filler to be added to a resin pellet without a long fiber filler is preferably 50% by mass or less in the resin pellet without a long fiber filler, more preferably 40% by mass or less, and further preferably 30% by mass or less. There is no particular restriction on the lower limit of the granular filler to be added, and the minimum quantity required to express the intended effect by addition should be added. An indicative addition amount of the granular filler is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more.
In the Embodiment, as a resin component constituting the resin pellet without a long fiber filler one or more selected from the group consisting of a styrenic resin, an olefinic resin, polyester, polyamide, polyarylene sulfide, polyetherimide, polyethersulfone, polysulfone and polyaryl ketone are exemplified, and a more preferable composition further contains polyphenylene ether.
In the Embodiment, as a resin component constituting the resin pellet without a long fiber filler, the thermoplastic resin blend described hereinabove in connection with the long fiber filler reinforced resin pellet can be favorably used.
In the Embodiment, a long fiber filler reinforced resin pellet and a resin pellet without a long fiber filler may contain an impact improver according to need. Although there is no particular restriction on the usable impact improver, a preferably applicable improver is at least one selected depending on the requirement out of a block copolymer composed of a polymer block A mainly constituted of at least one aromatic vinyl compound and a polymer block B mainly constituted of at least one conjugated diene compound (such block copolymer hereinafter occasionally simply abbreviated as “the block copolymer”), and an ethylene/α-olefin copolymer.
In the polymer block mainly constituted of an aromatic vinyl compound, “mainly constituted of” means that the block is constituted of at least 50% by mass of an aromatic vinyl compound. More preferably is the content 70% by mass or more, further preferably 80% by mass or more, and still further preferably 90% by mass or more.
In the polymer block mainly constituted of a conjugated diene compound, “mainly constituted of” means similarly that the block is constituted of at least 50% by mass of a conjugated diene compound. More preferably is the content 70% by mass or more, further preferably 80% by mass or more, and still further preferably 90% by mass or more.
In the Embodiment, a polymer block in the block copolymer may be a copolymer block, and an aromatic vinyl compound content in a random copolymer part may be distributed uniformly or changing monotonously.
In a copolymer block there may exist respectively a plurality of uniform distribution parts and/or monotonously changing distribution parts of an aromatic vinyl compound content, and further in a copolymer block a plurality of parts of different aromatic vinyl compound contents may exist. In these cases, even if a smaller amount of a conjugated diene compound or other compound is bonded randomly in a block of an aromatic vinyl compound, so long as the block is constituted 50% by mass or more of an aromatic vinyl compound, such block is deemed as the block copolymer mainly constituted of an aromatic vinyl compound. The same is true with a conjugated diene compound.
As the block copolymer composed of a polymer block A mainly constituted of an aromatic vinyl compound and a polymer block B mainly constituted of a conjugated diene compound, generally block copolymers having the following structures can be exemplified.
(A-B)n, A-(B-A)n-B, B-(A-B)n+1, [(A-B)k]m+1-Z, [(A-B)k-A]m+1-Z, [(B-A)k]m+1-Z, [(B-A)k-B]m+1-Z
wherein Z represents a residue of a coupling agent or a residue of an initiator of a multi-functional organolithium compound. The n, k and m are respectively an integer of 1 or higher, generally from 1 to 5.
Among the above, the block copolymer is preferably a block copolymer having a bonding structure selected from A-B type, A-B-A type and A-B-A-B type, more preferably having A-B-A type or A-B-A-B type, and further preferably having A-B-A type. A mixture of them is naturally acceptable.
In the Embodiment, as an aromatic vinyl compound to be used for a block copolymer of an aromatic vinyl compound/a conjugated diene compound, one or more may be selected from, for example, styrene, α-methyl styrene, vinyl toluene, p-tert-butyl styrene and diphenylethylene, and styrene is preferable. The content of an aromatic vinyl compound in a block copolymer of an aromatic vinyl compound/a conjugated diene compound can be selected favorably in general from 1 to 70% by mass, preferably from 5 to 55% by mass, and more preferably from 10 to 55% by mass.
As a conjugated diene compound to be used for a block copolymer of an aromatic vinyl compound/a conjugated diene compound, one or more may be selected from, for example, butadiene, isoprene, 1,3-pentadiene and 2,3-dimethyl-1,3-butadiene, and butadiene, isoprene and a combination thereof are preferable.
In the Embodiment, the block copolymer may be a hydrogenated block copolymer. A hydrogenated block copolymer means the block copolymer of an aromatic vinyl compound/a conjugated diene compound that is hydrogenated to regulate the rate of an aliphatic double bond (i.e. the hydrogenation rate) in the polymer block mainly constituted of a conjugated diene compound in a range beyond 0 and 100%. The hydrogenation rate of the hydrogenated block copolymer is preferably 50% or higher, more preferably 80% or higher, and further preferably 98% or higher.
As a specific example of a hydrogenation method, in a hydrocarbon solvent a hydrogenation catalyst and hydrogen gas are added for causing a hydrogenation reaction to decrease olefinic unsaturated bonds derived from a conjugated diene compound existing in the block copolymer so that a hydrogenated block copolymer can be obtained. There is no particular restriction on the method for hydrogenation reaction, insofar as olefinic unsaturated bonds derived from a conjugated diene compound existing in the block copolymer can be decreased.
In the Embodiment, the block copolymer of an aromatic vinyl compound/a conjugated diene compound having a functional group, which is prepared by further reacting the block copolymer with an unsaturated compound having a functional group (e.g. a carboxylic group, an acid anhydride group, an ester group and a hydroxy group), and a hydrogenated block copolymer having a functional group, which is prepared by hydrogenation of said block copolymer, can be also used.
In the Embodiment, the mixture of the non-hydrogenated block copolymer and the hydrogenated block copolymer can be used as the block copolymer without any problem.
In the Embodiment, as disclosed in the pamphlet of WO 02/094936, a block copolymer that is totally or partially modified or a block copolymer blended in advance with an oil may be also favorably utilized.
In the Embodiment, an ethylene/α-olefin copolymer is a copolymer of ethylene and at least one type of C3 to C20 α-olefin. Specific examples of said C3 to C20 α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene and a combination thereof. A copolymer using a C3 to C12 α-olefin out of said α-olefins is preferable.
The content of an α-olefin in the ethylene/α-olefin copolymer is preferably from 1 to 30 mol %, more preferably from 2 to 25 mol %, and further preferably 3 to 20 mol %.
In the Embodiment, at least one type of a non-conjugated diene, such as 1,4-hexadiene, dicyclopentadiene, 2,5-norbornadiene, 5-ethylidene norbornene, 5-ethyl-2,5-norbornadiene and 5-(1′-propenyl)-2-norbornene, may be further copolymerized.
In general, an ethylene/α-olefin copolymer may be also used as an ethylene/α-olefin copolymer having a functional group that is prepared by reacting an ethylene/α-olefin copolymer with an unsaturated compound having a functional group (e.g. a carboxylic group, an acid anhydride group, an ester group and a hydroxy group), a copolymer of ethylene and a monomer having a functional group (e.g. an epoxy group, a carboxylic group, an acid anhydride group, an ester group and a hydroxy group) and a copolymer of ethylene/α-olefin/a monomer having a functional group.
In the Embodiment, the content of an impact improver to be added is preferably from 1 to 15 parts by mass based on total 100 parts by mass of polyphenylene ether and a thermoplastic resin other than polyphenylene ether, and more preferably from 3 to 12 parts by mass.
If the content is 1 part by mass or higher, the toughness of a molded article molded from a long fiber filler reinforced pellet is improved, and if the content is 15 parts by mass or lower, mechanical strength and heat resistance become superior.
In the Embodiment, a long fiber filler reinforced resin pellet, a resin pellet without a long fiber or a resin pellet blend may further contain an electroconductive carbon filler.
Examples of an electroconductive carbon filler include electroconductive carbon black, carbon nanotube and carbon fiber.
An example of electroconductive carbon black is Ketjen Black (EC, EC-600JD) available from Ketjen Black International Co. Ltd.
An example of carbon nanotube is a carbon fibril (BN FIBRIL) available from Hyperion Catalysis International Inc. Among carbon fibrils, a carbon fibril as disclosed in the pamphlet for WO 94/23433 is preferable.
In the Embodiment, although there is no particular restriction on the method for adding the electroconductive carbon filler, examples thereof include:
(1) By production of the long fiber filler reinforced resin pellet, an electroconductive carbon filler and the thermoplastic resin blend are premixed;
(2) By production of a resin pellet without a long fiber filler, an electroconductive carbon filler and the resin component are premixed; and
(3) By production of the resin pellet blend, the long fiber filler reinforced resin pellet, according to need a resin pellet without a long fiber and a master batch, in which an electroconductive carbon filler is premixed with a thermoplastic resin other than polyphenylene ether, are admixed.
Also in the methods (1) and (2), an electroconductive carbon filler should preferably be added in the form of a master batch premixed with a thermoplastic resin other than polyphenylene ether. In case an electroconductive carbon filler in a master batch is electroconductive carbon black, the content thereof should be preferably from 5 to 15% by mass, and in case of other electroconductive carbon fillers, the content thereof should be preferably from 10 to 30% by mass. More preferably, in case an electroconductive carbon filler is electroconductive carbon black, the content is from 7 to 12% by mass, and in case of other electroconductive carbon fillers, the content is from 15 to 25% by mass.
Examples of a master batch, in which an electroconductive carbon filler is already admixed in a thermoplastic resin other than polyphenylene ether, more particularly technical examples in case polyamide is used as the thermoplastic resin, include a master batch in which electroconductive carbon black is dispersed homogeneously in polyamide in advance as disclosed in Japanese Patent Application Laid-Open No. 02-201811, a masterbatch in which electroconductive carbon black is dispersed in polyamide with appropriate nonuniformity as disclosed by the present inventor in U.S. Pat. No. 6,942,823, and a carbon fibril master batch, such as a master batch of polyamide 66/carbon fibril (trade name: Polyamide 66 with FIBRIL™ Nanotubes RMB4620-00; carbon fibril content 20%) available from Hyperion Catalysis International Inc. Similar examples can be presented for thermoplastic resins other than polyamide.
As a master batch in the Embodiment, a master batch in which electroconductive carbon black is dispersed in a thermoplastic resin with appropriate nonuniformity is preferable.
A preferable master batch with appropriate nonuniformity in dispersion means more specifically, if under an optical microscope a continuous area of 3 mm2 is observed, at least a part of electroconductive carbon black exists forming aggregates with the major diameter from 20 to 100 μm in number of 1 to 100. In more preferable master batch, if under an optical microscope a continuous area of 3 mm2 is observed, the aggregates of electroconductive carbon black with the major diameter from 20 to 100 μm exist in number of 2 to 30.
The observation of the aggregates of electroconductive carbon black in a master batch may follow the method disclosed in U.S. Pat. No. 6,942,823.
A production process for the long fiber filler reinforced resin pellet of the Embodiment includes the steps of: (1) producing a thermoplastic resin blend in a molten state by an extruder, (2) impregnating a long fiber filler into the thermoplastic resin blend in a molten state, (3) forming a resin strand by drawing and twisting, and (4) cutting the resin strand to a pellet form.
In the Embodiment, the steps (1) to (4) are preferably included continuously in said successive order.
In the Embodiment, a facility including, as disclosed in Japanese Patent Application Laid-Open No. 2003-175512, an extruder for melting and blending the resin, a dipping bath vessel installed downstream thereof for impregnating the resin into reinforcing long fibers, and twisting rolls for twisting a resin impregnated resin strand, should preferably be used.
In the Embodiment, twisting the long fiber filler may have an effect on accelerating impregnation of a resin into the long fiber filler. The step has another effect of discharging air trapped among fibers of the long fiber filler outside the cross-section of the strand.
Examples of a method for twisting include a method of rotating the outlet of a die around the axis of the strand by a motor, and a method using a twister which rotates the strand during drawing around the axis along the drawing direction of the strand.
In the Embodiment, for example, a twister has facing rolls with differently oriented rotating axes, and by passing the resin impregnated long fiber filler through the rolls of the twister the same can be twisted. The twister is installed preferably between a water bath and a pelletizer.
As an extruder to be used for melting and kneading the resin in the step (1), any of a single screw extruder, a twin screw extruder and a kneader may be used, and a twin screw extruder is preferable.
Examples of a specific process for producing a thermoplastic resin blend in a molten state include (1A) a method by which a thermoplastic resin blend prepared in advance by melting and kneading polyphenylene ether and a thermoplastic resin other than polyphenylene ether is fed into an extruder to be molten again, (1B) a method by which polyphenylene ether and a thermoplastic resin other than polyphenylene ether are respectively fed simultaneously to the same feeding port of the extruder for melting and kneading, and (1C) a method by which polyphenylene ether and a thermoplastic resin other than polyphenylene ether are respectively fed to different feeding ports of the extruder for melting and kneading, and any of them may be applied.
Among them, the method (1B) or (1C) is more preferable.
Which of the method (1B) or (1C) is more preferable, depends on a type of the thermoplastic resin other than polyphenylene ether to be used. For example, if a resin highly compatible with polyphenylene ether is used as the thermoplastic resin other than polyphenylene ether, the method (1B) may be selected generally. On the other hand with a resin poorly compatible with polyphenylene ether, the method (1C) is preferable generally. More specific examples thereof include, a method by which polyphenylene ether and a compatibilizer are charged through a feeding port of the extruder, and after a functionalization step of polyphenylene ether a thermoplastic resin other than polyphenylene ether is added for kneading through a different feeding port located at a downstream stage, and a method by which a mixture of a part of the thermoplastic resin other than polyphenylene ether and polyphenylene ether is charged through a feeding port of the extruder, and the rest of the thermoplastic resin other than polyphenylene ether is charged to a downstream feeding port. In any case by use of a thermoplastic resin poorly compatible with polyphenylene ether, a publicly known production process effective for compatibilization may be applied.
In order to add a filler other than the long fiber filler into the long fiber filler reinforced resin pellet of the Embodiment, there is no particular restriction on the feeding location for said filler, and it may be fed similarly as a resin to a feeding port at the most upstream location or to a feeding port located at the stage where the resin has reached a molten state. An extruder with a plurality of feeding ports in downstream stages can be favorably used.
In the Embodiment, the set temperature of the dipping bath in the step (2) should preferably be set at a temperature, at which the melt viscosity at a shear rate of 1,000 sec−1 becomes in a range from 10 to 200 Pa·s. The melt viscosity of a thermoplastic resin blend is more preferably 20 Pa·s or higher, further preferably 30 Pa·s or higher, and still further preferably 40 Pa·s or higher. The melt viscosity of a thermoplastic resin blend is more preferably 180 Pa·s or lower, further preferably 150 Pa·s or lower, and still further preferably 100 Pa·s.
Although the melt viscosity of a thermoplastic resin blend may vary depending upon a type of a thermoplastic resin other than polyphenylene ether, the viscosities of respective resin components, and existence or non-existence and a quantity of a compatibilizer, it is very effective to regulate appropriately the set temperature of the dipping bath, so that the melt viscosity of the resin can be adjusted to a desired value.
The set temperature of the dipping bath in the step of impregnating the long fiber filler with the thermoplastic resin blend in a molten state, should be preferably set at a temperature higher by 20° C. or more than a set temperature of the extruder in the step for producing the thermoplastic resin blend in a molten state. This temperature setting is also valuable for adjusting the viscosity of the molten resin in the aforementioned viscosity range. More preferably, the set temperature of the dipping bath is higher by 30° C. or more than a set temperature of the extruder in the step for producing the thermoplastic resin blend in a molten state. Although there is no particular upper limit of the set temperature of the dipping bath, to avoid degradation of the resin, 50° C. may be a practical limit.
The temperature, at which the melt viscosity of a thermoplastic resin blend at a shear rate of 1,000 sec−1 falls within 10 to 200 Pa·s, is in a range from 280 to 350° C. in case a thermoplastic resin other than polyphenylene ether is, for example, PPS, and therefore, as a rough rule, the thermoplastic resin blend is required to be so prepared that the melt viscosity at 310° C. and a shear rate of 1,000 sec−1 falls within 10 to 200 Pa·s.
In the Embodiment, it is preferable to install several rolls in the dipping bath in order to fibrillate the long fiber filler and accelerate the impregnation.
The drawing speed of a resin strand in the step (3) of the production process of the pellet of the Embodiment is preferably from 10 to 150 m/min, more preferably 20 m/min or higher, and further preferably 35 m/min. The drawing speed of a resin strand is more preferably 100 m/min or lower, and further preferably 80 m/min.
The drawing speed of a resin strand in the step (3) is from 10 to 150 m/min, which is higher than a usual speed enabling utilization of the non-Newtonian property of viscosity, so that improvement of impregnation of the resin into the long fiber filler can be effectuated effectively.
There is no particular restriction on the production process for a resin pellet without a long fiber filler that is able to constitute the resin pallet blend of the Embodiment, insofar as it is publicly known, and any apparatus among a single screw extruder, a twin screw extruder, Brabender and a kneader may be used.
There is no particular restriction on the production process for a resin pellet blend containing a long fiber filler reinforced resin pellet of the Embodiment, but a production process to mix a desired amounts of the long fiber filler reinforced resin pellet and the resin pellet without a long fiber filler using a blending/agitating apparatus, such as a tumbler, a screw blender and a Henschel mixer, is preferable.
A molded article of the Embodiment is a molded article to be obtained by melt-molding the long fiber filler reinforced resin pellet, and a molded article to be obtained by melt-molding the resin pellet blend.
In the Embodiment, a molded article includes a bulk-form molded article by injection molding, a film/sheet-form molded article by extrusion or inflation molding and a molded article by profile extrusion molding.
Molded articles obtained by melt-molding the pellet and/or the resin pellet blend may be used industrially as various parts. They can be used favorably, for example, for electrical or electronic parts, such as an IC tray materials and a chassis and a cabinet for various disk players, OA parts and machine parts for various computers and their peripheral devices, etc., further for a cowl of a motorbike, automobile exterior parts, such as a fender, a door panel, a front panel, a rear panel, a locker panel, a rear bumper panel, a back door garnish, an emblem garnish, a panel for a feeding port of fuel, an over fender, an outer door handle, a door mirror housing, a bonnet air intake, a bumper, a bumper guard, a roof rail, a roof rail leg, a pillar, a pillar cover, a wheel cover, various aerodynamic parts as represented by a spoiler, various decorations and emblems, and interior parts, as represented by an instrument panel, a console box and a trim.
In the Embodiment, an electroconductive molded article containing an electroconductive carbon filler can be favorably utilized for mechanical parts requiring preventive measures against malfunctioning caused by static electricity and interior or exterior parts requiring electroconductivity.
In the Embodiment, it is preferable to use an injection molding machine equipped with a screw for a long fiber filler for injection-molding the long fiber filler reinforced resin pellet from the viewpoint of maintaining the length of the long fiber filler long in a molded article. The weight average fiber length of the long fiber filler in a molded article is preferably in a range from 1 mm to 7 mm. The more preferable lower limit is 1.2 mm or longer, and the more preferable upper limit is 5 mm. From the viewpoint of suppression of the anisotropy and improvement of the surface impact strength of a molded article to be obtained, the lower limit is preferably 1 mm or longer, and from the viewpoint of prevention of deterioration of the appearance of a molded article, the upper limit is preferable set at 7 mm or shorter.
The Embodiment will now be described in more detail by way of Examples thereof and Comparative Examples, provided that the Embodiment should not be limited to the Examples. The evaluation methods and the measurement methods in the Embodiment are described below.
polyphenylene ether (PPE-1): reduced viscosity ηsp/c: 0.51 dL/g
polyphenylene ether (PPE-2): reduced viscosity ηsp/c: 0.42 dL/g
polyphenylene ether (PPE-3): polyphenylene ether polymerized according to Japanese Patent Publication No. 60-34571
polyphenylene ether copolymer (PPE-4): polyphenylene ether copolymer polymerized according to Japanese Patent Application Laid-Open No. 64-33131
Styrenic Resin
homo-polystyrene (PS-1): Polystyrene 680 procured from PS Japan Corp.
homo-polystyrene (PS-2): Styron 685 (Registered trade name) procured from Dow Chemical Co. (USA)
high impact-polystyrene (PS-3): high impact-polystyrene procured from PS Japan Corp.
polypropylene (PP-1): homo-polypropylene
polypropylene (PP-2): homo-polypropylene
polypropylene (PP-3): homo-polypropylene
liquid crystal polyester (LCP): liquid crystal polyester prepared according to Preparation Example 1
melting point (DSC method): 319° C.
melt viscosity (330° C., shear rate 100 sec−1): 18 Pa·s
polyamide 6,6 (PA66): Vydyne 48BX (Registered trade name) procured from Solutia Inc. (USA)
polyamide 9,T (PA9T): polyamide 9T prepared according to Preparation Example 2
polyphenylene sulfide (PPS-1): cross-linked type poly(p-phenylene sulfide)
polyphenylene sulfide (PPS-2): semi-cross-linked type poly(p-phenylene sulfide)
polyphenylene sulfide (PPS-3): linear type poly(p-phenylene sulfide)
polyphenylene sulfide (PPS-4): linear type poly(p-phenylene sulfide)
polyphenylene sulfide (PPS-5): linear type poly(p-phenylene sulfide)
polyphenylene sulfide (PPS-6): linear type poly(p-phenylene sulfide)
polyphenylene sulfide (PPS-7): semi-cross-linked type poly(p-phenylene sulfide)
polyphenylene sulfide (PPS-8): cross-linked type poly(p-phenylene sulfide)
polyphenylene sulfide (PPS-9): semi-cross-linked type poly(p-phenylene sulfide)
polyarylate (PAR): U-Polymer U-100 (Registered trade name) procured from Unitika Ltd.
polyetherether ketone (PEEK): VICTREX PEEK 151G (Registered trade name) procured from Victrex plc.
Impact improver (By use in PP, it functions also as a compatibilizer.)
polystyrene block-hydrogenated polybutadiene-polystyrene block-(SEBS-1)
polystyrene block-hydrogenated polybutadiene-polystyrene block (SEBS-2)
polystyrene block-hydrogenated polybutadiene-polystyrene block (SEBS-3)
polystyrene block-hydrogenated polybutadiene-polystyrene block (SEBS-4)
phosphate based flame retardant (FR-1): CR-741 procured from Daihachi Chemical Ind.
aluminum phosphinate (FR-2): Exolit OP930 (Registered trade name) procured from Clariant.
glass fiber filler (LGF): ER2400T-448N procured from Nippon Electric Glass Co., Ltd.
maleic anhydride (MAH): CRYSTAL MAN-AB procured from NOF Corporation
styrene/glycidyl methacrylate copolymer (SG-C)
styrene/2-isopropenyl-2-oxazoline copolymer (SO—C)
sterically-hindered phenolic antioxidant (Irg1098)
In a 2-L polymerization reactor with a stirrer and a evaporation line p-hydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, hydroquinone, 2,6-naphthalenedicarboxylic acid and acetic anhydride were charged and subjected to a polycondensation eliminating acetic acid according to the following procedures. The reactor charged with raw materials was heated from 40° C. to 190° C. over 3 hours under a nitrogen gas atmosphere, kept at 190° C. for 1 hour, further heated up to 325° C. over 2 hours, and left for reaction for 10 min. Next the reactor was vacuumed to 20 mmHg at 325° C. for 20 min, and left for reaction additionally for 5 min to complete polycondensation. As the result of polymerization, substantially theoretical amount of acetic acid was distilled off to obtain the liquid crystal polyester having the theoretical structural formula as represented by the following formula.
The melting point by DSC was 319° C. The melt viscosity measured using a capillary rheometer at 330° C. and shear rate of 1,000 sec−1 was 18 Pa·s. Concerning a composition, the ratio of components represents mol ratio.
According to the method described in an example of Japanese Patent Laid-Open No. 2000-103847, terephthalic acid as a dicarboxylic acid component, 1,9-nonamethylenediamine and 2-methyl-1,8-octamethylenediamine as diamine components, octylamine or benzoic acid as a terminal capping agent, sodium hypophosphite monohydrate as a polymerization catalyst, and distilled water were charged into an autoclave, which was closed hermetically (water content in the reaction system: 25% by mass). After replaced thoroughly with nitrogen, the autoclave was heated up over 2 hours to the internal temperature of 260° C. with stirring, and left reacting under the same condition. The internal pressure was 46 atm.
Next, keeping the internal temperature of the reactor at 260° C. and the water content at 25% by mass, the reaction product was discharged through a nozzle (6 mm diameter) at the bottom of the reactor over 3 min under a nitrogen atmosphere into a container at normal temperature and pressure, and dried at 120° C. to obtain foamless powder-form primary polycondensate.
Then, the powder-form primary polycondensate was heated up to 250° C. over 2 hours under a nitrogen atmosphere and with stirring, and kept under the same condition for a predefined time period to conduct a solid state polymerization.
Measurements of the capped terminus rate and the terminal group concentration of the obtained aromatic polyamide were conducted according to the measurement of the capped terminus rate described in an example of Japanese Patent Application Laid-Open No. 07-228689, and quantitative analysis of a phosphorus element was conducted by inductively coupled plasma (ICP) spectrometry using IRIS/IP manufactured by Thermo Jarrell Ash Corp. using the wave length of 213.618 (nm). The terminal amino group concentration was 20 μmol/g, the terminal carboxyl group concentration was 65 μmol/g, and the capped terminus rate was 55%.
Using the resin pellets and strands obtained in Examples 1 to 70, the evaluations of the following items were conducted.
By Capirograph (Toyo Seiki Seisaku-sho, Ltd.) using a capillary of capillary length=10 mm and capillary diameter=1 mm, apparent melt viscosities were measured at 2 shear rates containing the shear rate of 1,000 sec−1 at an individually described temperature, and the value was determined by extrapolating them to 1,000 sec11.
During extrusion of a long fiber filler reinforced resin pellet, about 30 cm of a strand was sampled, and the length required for 1 round on the outer surface of the strand by a pattern of a twist of the contained long fiber filler (glass fiber) standing out on the outer surface of the strand was directly measured.
After measuring the average length of pellets, the resin component of the pellets was burnt at 650° C. in an electrical oven. Then out of the obtained long fiber fillers (glass fibers), only the lengths of the fiber fillers which were 3 mm or longer were measured by an image analyzer and the weight average fiber length was calculated according to the following formula and the ratio of the average fiber length of the long fiber filler to the length of the pellet was determined. Thereby at least 500 fibers were measured.
Lw=Σ(Li2×Ni)/(Li×Ni)
wherein Lw represents the weight average fiber length, Li represents representative fiber lengths of respective groups and Ni represents numbers of the long fiber fillers of the respective groups. Thereby the long fiber fillers were classified to groups at 0.1 mm intervals and the median fiber length of the fiber length range was designated as the representative fiber length of the group. As a specific example, long fiber fillers (glass fibers) having the fiber length beyond 3 mm and equal to or less than 3.1 mm are classified into a group whose representative fiber length is designated as 3.05 mm.
The resin component of a resin pellet was burnt in an electrical oven set at 650° C., and based on the weighed residue weight the rate of the contained long fiber filler (glass fiber) was determined.
(Impregnation Property of Resin into Long Fiber Filler)
A propyl alcohol solution of methyl red as a color indicator was prepared by adding 1 cm3 of hydrochloric acid to adjust the pH and improve coloring property of methyl red into a 50 cm3 of a saturated solution of methyl red in propyl alcohol. Arbitrarily selected 10 strands were dipped in the solution up to 1 cm from the fracture cross-section for about 30 min. Thereafter the strands were taken out and a longitudinal penetration situation of the color indicator was examined. Then the impregnation property of a resin into a long fiber filler was evaluated according to the penetration situation of the color indicator from the fracture cross-section of the strand. By averaging the penetration distances of the 10 strands, rating was given according to: in case the average penetration length is 5 mm or less: “good”; in case 5 mm to 10 mm: “fair”; and in case 10 mm or longer: “poor”.
A pellet was cut to the width direction by a microtome to a flat cross-section, which was observed under an optical microscope with reflection light and photographed. By image analysis the ratio of the cross-section of the core part to the core-section of the pellet was calculated.
The pellet surface was visually observed. A pellet with sufficient glossy surface was rated as A, a pellet with partly not glossy surface was rated as B, and a pellet with mostly not glossy surface was rated as C.
Randomly selected 100 pellets were enclosed hermetically in a 50 cm3 metal container and shaken at an amplitude of 50 mm and a frequency of 60 cycles/min, and then the pellets inside were taken out and the number of pellets that have caused a longitudinal fracture was counted.
The amount of the long fiber fillers (glass fibers) attached to the wall surface of the metal container at the evaluation of the longitudinal fracture of pellets was visually rated.
The obtained long fiber filler reinforced resin pellet was molded to a multi-purpose test specimen with the thickness of 4 mm according to ISO 294-1 using IS100GN (Toshiba Machine Co., Ltd.) equipped with a screw having a low compression ratio suitable for molding a long fiber filler reinforced resin pellet. The resin component of the obtained multi-purpose test specimen was burnt at 650° C. in an electrical oven, after slow cooling the specimen was taken out gently, and the form retainability of the ash (whether the form of a multi-purpose test specimen is maintained by the network of a long fiber filler) was rated. Thereby with good fibrillation property of a long fiber filler, a network of a long fiber filler is easier to be formed during molding, which increases the form retainability. On the contrary with poor fibrillation property during molding, the network is formed insufficiently and the form retainability becomes very poor. Consequently, the fibrillation property of a long fiber filler was rated by the form retainability.
The criteria of the form retainability are shown below:
AA: The form of a multi-purpose test specimen is substantially maintained.
A: The form except a part around a gate is maintained.
B: The form of a flow front is only maintained.
C: The form is not maintained.
The obtained long fiber filler reinforced resin pellet was molded to a flat test specimen with the size of 50×90×2.5 mm using IS100GN (Toshiba Machine Co., Ltd.) equipped with a screw having a low compression ratio suitable for molding a long fiber filler reinforced resin pellet. Using the obtained test specimen, the total absorbed energy at an impact test at 23° C. was measured by Graphic Impact Tester (Toyo Seiki-Seisakusho, Ltd.) using a holder of diameter 40 mm and a striker of diameter 12.7 mm and mass of 6.5 kg impacting from the height of 128 cm.
A multi-purpose test specimen with the thickness of 4 mm according to ISO 294-1 was molded by the same extruder used for molding a test specimen for measuring surface impact strength.
Using the obtained multi-purpose test specimen, a flatwise deflection temperature under load was measured according to ISO 75 with loads of 0.45 MPa and/or 1.8 MPa.
A multi-purpose test specimen with the thickness of 4 mm according to ISO 294-1 was molded by the same extruder used for molding a test specimen for measuring surface impact strength. Using the obtained multi-purpose test specimen, a notched Charpy impact strength was measured at 23° C. according to ISO 179.
Using the multi-purpose test specimen obtained similarly as the test specimen for Charpy impact strength, a flexural strength was measured according to ISO 178.
The maximum cylinder temperature of a co-rotating twin screw extruder (ZSK25: Coperion) with L/D=42, having an upstream feeding port and a downstream feeding port, was set at 320° C. PS/PPE1 was obtained by feeding 20 parts by mass of PPE-1 and 20 parts by mass of PS-1 respectively through the upstream feeding port to the extruder, and feeding 60 parts by mass of PS-1 through the downstream feeding port; to be melt-blended, while evaporating a volatile matter under a reduced pressure through a venting port provided downstream of the downstream feeding port; and cooling by water, drawing and cutting the strand. Thereby the screw rotation speed was set at 300 rpm. The melt viscosity of the obtained PS/PPE1 was measured by a capillary rheometer to find that the temperature was about 300° C. at which the melt viscosity at a shear rate of 1,000 sec−1 became 20 to 100 Pa·s.
Except that 50 parts by mass of PPE-1 and 20 parts by mass of PS-1 were respectively fed through the upstream feeding port to the extruder, and that 30 parts by mass of PS-2 was fed through the downstream feeding port, all other conditions were performed identically with the production of PS/PPE1 to obtain PS/PPE2. The melt viscosity of the obtained PS/PPE2 was measured by a capillary rheometer to find that the temperature was beyond 320° C. at which the viscosity at a shear rate of 1,000 sec−1 became 200 Pa·s.
Except that 40 parts by mass of PPE-2 and 10 parts by mass of PS-1 were respectively fed through the upstream feeding port to the extruder, and that 50 parts by mass of PS-1 were fed through the downstream feeding port, all other conditions were performed identically with the production of PS/PPE1 to obtain PS/PPE3. The melt viscosity of the obtained PS/PPE3 was measured by a capillary rheometer to find that the temperature was about 310° C. at which the melt viscosity at a shear rate of 1,000 sec−1 became 20 to 100 Pa·s.
Except that the PPE to be fed through the upstream feeding port was changed to PPE-3, all other conditions were performed identically with the production of PS/PPE1 to obtain PS/PPE4. The melt viscosity of the obtained PS/PPE4 was measured by a capillary rheometer to find that the temperature was about 280° C. at which the melt viscosity at a shear rate of 1,000 sec−1 became 20 to 100 Pa·s.
Except that the PPE to be fed through the upstream feeding port was changed to PPE-4, all other conditions were performed identically with the production of PS/PPE1 to obtain PS/PPE5. The melt viscosity of the obtained PS/PPE5 was measured by a capillary rheometer to find that the temperature was about 330° C. at which the melt viscosity at a shear rate of 1,000 sec−1 became 20 to 100 Pa·s.
Except that the 55 parts by mass of PPE-1 and 45 parts by mass of PS-2 were respectively fed through the upstream feeding port to the extruder and that nothing was added through the downstream feeding port, all other conditions were performed identically with the production of PS/PPE1 to obtain PS/PPE6.
This PS/PPE6 was blended with a long fiber filler reinforced resin pellet and used when the properties of a molded article were measured.
The maximum cylinder temperature of a co-rotating twin screw extruder (ZSK40MC: Coperion) with L/D=48, having an upstream feeding port and a downstream feeding port; 12 temperature regulating blocks, each block constituting L/D=4; and an auto-screen changer block; and thereby the upstream feeding port being located at the first block, the downstream feeding port at the sixth block and a venting ports for removing a volatile matter by evaporation under a reduced pressure at the fifth and tenth blocks; was set at 320° C. Feeding 35 parts by mass of PPE-1, 0.1 parts by mass of MAH, 10 parts by mass of SEBS and 5 parts by mass of PS-3 were respectively fed through an upstream feeding port to the extruder to be melt-blended, and successively 50 parts by mass of PA66 was fed through a downstream feeding port to be subjected to melt-blending, to obtain PA/PPE1. Thereby the screw rotation speed was at 450 rpm. The melt viscosity of the obtained PA/PPE1 was measured to find that the temperature was about 300° C. at which the melt viscosity at a shear rate of 1,000 sec−1 became 15 to 100 Pa·s. The melt viscosity at 280° C. was confirmed to be 220 Pa·s.
Using the same extruder as in the production of PA/PPE1, 40 parts by mass of PPE-2, 0.4 parts by mass of MAH were dry-blended and fed through the upstream feeding port to the extruder to be melt-blended, and successively 60 parts by mass of PA9T were fed through a downstream feeding port to be melt-blended to obtain PA/PPE2. All of other conditions were identical with the production of PA/PPE1. The melt viscosity of the obtained PA/PPE2 was measured to find that the temperature was 330° C. at which the melt viscosity at a shear rate of 1,000 sec−1 became 15 to 100 Pa·s.
Except that the polyphenylene ether was changed to PPE-3, all other conditions were performed identically with the production of PA/PPE1 to obtain PA/PPE3.
Except that the polyphenylene ether was changed to PPE4, all other conditions were performed identically with the production of PA/PPE1 to obtain PA/PPE4.
The cylinder temperature of the extruder used for production of PA-PPE1 was set at 290 to 310° C., and a resin blend with a blend composition described in Table 1 was fed through the upstream feeding port of the extruder, melt-blended and vented from vacuum venting ports at 2 locations under the vacuum of the absolute vacuum pressure of 95 kPa or less while melt-blending to produce 5 types of resin blends of PP/PPE1 to PP/PPE5. Thereby SEBS exerted two functions of a compatibilizer between PP and polyphenylene ether and an impact improver. The melt viscosities of the obtained resin blends were measured under the conditions of 280° C. and 300° C. and at a shear rate of 1,000 sec−1, and are included in Table 1.
The cylinder temperature of the extruder used for production of PA-PPE1 was set at 290 to 310° C., and a resin blend with a blend composition described in Table 2 was fed through the upstream feeding port of the extruder, melt-blended, and vented from vacuum venting ports at 2 locations under the vacuum of the absolute vacuum pressure of 95 kPa or less while melt-blending to produce 16 types of resin blends of PPS/PPE1 to PPS/PPE16. Further, the melt viscosities of the obtained resin blends were measured at 300° C. and a shear rate of 1,000 sec−1, and are included in Table 2.
The maximum cylinder temperature of the extruder used for production of PS/PPE1 was set at 330° C., and 30 parts by mass of PPE-2, 15 parts by mass of LCP and 5 parts by mass of SG-C were respectively fed through the upstream feeding port to the extruder and 55 parts by mass of LCP was fed through the downstream feeding port, to be melt-blended, while evaporating a volatile matter under a reduced pressure through a venting port provided downstream of the downstream feeding port. The strand was cooled by water, drawn and cut to obtain LCP/PPE1. Thereby the screw rotation speed was 300 rpm. The melt viscosity of the obtained LCP/PPE1 was measured by a capillary rheometer to find that the temperature was about 330° C. at which the melt viscosity at a shear rate of 1,000 sec− became 20 to 100 Pa·s.
Except that 55 parts by mass of PPE-1, 15 parts by mass of LCP and 5 parts by mass of SG-C were respectively fed through the upstream feeding port, and that 30 parts by mass of LCP was fed through the downstream feeding port, all other conditions were performed identically with LCP/PPE1 to obtain LCP/PPE2. The melt viscosity of the obtained LCP/PPE2 was measured by a capillary rheometer to find that the temperature was beyond 330° C. at which the viscosity at a shear rate of 1,000 sec−1 became 200 Pa·s.
Except that 40 parts by mass of PPE-2, 30 parts by mass of LCP and 5 parts by mass of SG-C were respectively fed through the upstream feeding port to the extruder to be melt-blended; that successively 30 parts by mass of LCP were fed through the downstream feeding port; and that 7 parts by mass of FR-1 were fed through a liquid feeding nozzle located further downstream; all other conditions were performed identically with the production of LCP/PPE1 to obtain LCP/PPE3. The melt viscosity of the obtained LCP/PPE3 was measured by a capillary rheometer to find that the temperature was about 320° C. at which the melt viscosity at a shear rate of 1,000 sec−1 became 20 to 100 Pa·s.
Except that the polyphenylene ether to be fed through the upstream feeding port was changed to PPE-3, all other conditions were performed identically with the production of LCP/PPE2 to obtain LCP/PPE4.
The maximum cylinder temperature of the extruder used for production of PS/PPE1 was set at 355° C., and 30 parts by mass of PPE-2, 15 parts by mass of PEEK and 5 parts by mass of PAR were respectively fed through the upstream feeding port to the extruder and 55 parts by mass of PEEK were fed through the downstream feeding port, to be melt-blended, while evaporating a volatile matter under a reduced pressure through a venting port provided downstream of the downstream feeding port. The strand was cooled by water, drawn and cut to obtain PEEK/PPE. Thereby the screw rotation speed was set at 300 rpm. The melt viscosity of the obtained PEEK/PPE was measured by a capillary rheometer to find that the temperature was about 380° C. at which the melt viscosity at a shear rate of 1,000 sec−1 became 20 to 100 Pa·s.
The maximum cylinder temperature of an extruder in a production facility of a long fiber reinforced resin, which was a co-rotating twin screw extruder (ZSK25: Coperion) provided with an feeding port at an upstream zone and a dipping bath with resin impregnating rolls (Kobe Steel, Ltd.) installed at the front end of the co-rotating twin screw extruder, was set at 320° C., and PS/PPE1 was fed through the extruder feeding port, and molten at a screw rotation speed of 300 rpm and filled in the dipping bath with resin impregnating rolls. Meanwhile, 2 long-fiber glass fiber rovings with filament diameter of 17 μm (ER2400T-448N by Nippon Electric Glass Co., Ltd.) were introduced from a roving supply stand to the dipping bath with resin impregnating rolls, where the molten resin in the dipping bath was impregnated into the long-fiber glass fiber rovings, which were then continuously drawn out through a nozzle (diameter 2.8 mm) of the dipping bath at the drawing speed of 15 m/min forming a single strand, cooled and solidified in a water bath, passed through twisting rolls for twisting varyingly the resin strand allowing to form twists of various lead lengths, and then cut by a pelletizer to 10 mm pellet length. Thereby the set temperature of the dipping bath was 300° C. Further, the extrusion rate of the extruder was so regulated that the glass fiber content became about 50% by mass.
Example 1 to Example 5 were different only in strength of twisting on the strand, and all other conditions were the same. The strength of twisting was changed by changing the rotation speed of the rolls of a twister placed between the water bath and the pelletizer.
Using the obtained resin pellets and strands, various evaluations were conducted. The results are shown in Table 3. Thereby, the evaluations of Charpy impact strength, flexural strength, high load DTUL were conducted by dry-blending 60 parts by mass of the obtained long fiber filler reinforced resin pellet and 40 parts by mass of PS/PPE6 pellet, then molding them under the conditions of cylinder temperature at 310° C. and a mold temperature at 90° C., and conducting measurements thereof. The results are shown in Table 3.
Except that PS/PPE1 was changed to PS/PPE2, all other conditions were performed identically with the example 3 to obtain a long fiber filler reinforced resin pellet, on which evaluations were conducted. The results are shown in Table 3.
Using chopped strand glass fiber (the surface being treated by a similar compound as for the long-fiber glass fiber) with filament diameter of 17 μm and fiber length of 3 mm, a composite pellet composed of 28% by mass of PS/PPE1, 42% by mass of PS/PPE6 and 30% by mass of chopped strand glass fiber was prepared. Thereby using the extruder used for preparing PS/PPE1 and setting the maximum set temperature of the cylinder at 300° C., the resin components were fed through the upstream feeding port, and the chopped strand glass fiber was fed through the downstream feeding port, and melt-extruded. The stand was cut to obtain a composite pellet with length of about 3 mm and diameter of about 3 mm. The measurement results of Charpy impact strength, flexural strength, high load DTUL are shown in Table 3.
Setting at 330° C. the cylinder temperature of the extruder in the same production facility of a long fiber reinforced resin as used in the example 1 to example 5, PS/PPE3 was fed through the extruder feeding port, molten at a screw rotation speed of 300 rpm and filled in the dipping bath with resin impregnating rolls. As in the example 1 to example 5, the long-fiber glass fiber rovings were introduced to the dipping bath with resin impregnating rolls, where the molten resin in the dipping bath was impregnated into the two long-fiber glass fiber rovings, which were then continuously drawn out through a nozzle part of the dipping bath at the drawing speed of 23 m/min forming a single strand, cooled and solidified in a water bath, passed through twisting rolls for twisting the resin strand to form a twist with a lead length of 30 mm, and then cut by a pelletizer to a pellet with a pellet length of 10 mm. Thereby the set temperature of the dipping bath was 320° C.
Further, the extrusion rate of the extruder was so regulated that the glass fiber content became about 50% by mass. The glass fiber content determined according to the later measurement of ash was 52.5% by mass.
Using the obtained resin pellets and strands, evaluations as in the example 1 to example 5 were conducted. Thereby, the evaluation of impact strength and DTUL of a molded specimen was conducted by pellet-blending 57 parts by mass of the long fiber filler reinforced resin pellet obtained in this example and 43 parts by mass of PS/PPE6 pellet, so that the glass fiber content became 30% by mass, and conducting similarly measurements of the properties thereof. The results are shown in Table 3.
Except setting the cylinder temperature of the extruder at 280° C., the screw rotation speed at 150 rpm and the temperature of the dipping bath at 280° C., all others procedures were identical with the example 8 to obtain a long fiber filler reinforced resin pellet. The evaluations were conducted similarly as in the example 8, and the results thereof are shown in Table 3.
Except that the resin blend of PS/PPE was changed to PS/PPE4, PS/PPE5 or only PS-1 without polyphenylene ether as described in Table 3, all other procedures and evaluations were performed identically with the example 3. The results are shown in Table 3. As for the example 12, in order to evaluate a composition without polyphenylene ether, 60 parts by mass of the obtained pellet were blended with 40 parts by mass of the pellet of PS-1, and the blend was molded under the conditions of the cylinder temperature at 210° C. and the mold temperature at 80° C., which was then evaluated. The results are shown in Table 3.
As obvious from the results in Table 3, all the pellets of the long fiber filler reinforced resins of Examples had excellent wettability, could extremely suppress longitudinal pellet fracture during transportation and detachment of the long fiber filler from the pellet, were superior in pellet appearance and were superior in fibrillation property of the long fiber filler during molding, enabling to mold a molded article with very high heat resistance and impact resistance.
On the other hand, in the examples 1 and 5, in which the spiral lead was outside the range of 20 mm to 80 mm, in comparison of the fibrillation property of long fiber filler, only a form at the flow front part was maintained indicating insufficient fibrillation property.
In the example 5 with the spiral lead of 100 mm, many detached long fiber fillers were recognized.
In the example 7, in which chopped strand glass fiber was used instead of the long fiber filler, since the glass fiber length in a molded article was not sufficient, the impact strength, flexural strength and heat resistance were insufficient.
Further, in the example 12 without polyphenylene ether, the fibrillation property was not sufficient and a molded article thereof had insufficient strength in the flexural strength, etc.
Using the same extruder as in the example 1 and setting the set temperature of the cylinder at 230° C. to 300° C. and the set temperature of the dipping bath at 220° C., 280° C. or 300° C., PP/PPE1 to PP/PPE5 and PP-1 were fed respectively through the feeding port of the twin-screw extruder, and were impregnated in the dipping bath which temperature was regulated at 220° C., 280° C. or 300° C., into 2 long-fiber glass fiber rovings, which were then continuously drawn out through an outlet nozzle (diameter about 3.5 mm) of the dipping bath at the drawing speed of 20 m/min forming a strand, which was after twisting cut by a pelletizer to a pellet length of 10 mm. Thereby the extrusion rate of the extruder was so regulated that the glass fiber content in the long fiber reinforced resin composition became 39% by mass.
Using the obtained resin pellets and strands, evaluations were conducted. The results are shown in Table 4. Thereby, blend of a long fiber filler reinforced resin pellet and a pellet without a long fiber filler was not conducted as in the example 1, the long fiber filler reinforced resin pellet was injection-molded singly and the properties were evaluated.
As obvious from the results in Table 4, all the pellets of the long fiber filler reinforced resins of Examples had excellent wettability, could extremely suppress longitudinal pellet fracture during transportation and detachment of the long fiber filler from the pellet, were superior in pellet appearance and were superior in fibrillation property of the long fiber filler during molding, enabling to mold a molded article with very high heat resistance and impact resistance.
On the other hand, in the examples 21 and 22, in which the cross-section of the core part exceeded 70% of the pellet cross-section, longitudinal pellet fracture occurred in many pellets, and many long fiber fillers were detached. Furthermore, the fibrillation property was not sufficient and the surface appearance of the pellets was not glossy.
Further, in the example 23, in which polyphenylene ether was not contained, longitudinal pellet fracture occurred in many pellets, the fibrillation property was not sufficient and in appearance property the pellet surface was not glossy. Furthermore, the molded article did not have sufficient strength in impact resistance, etc.
Setting at 280° C. the cylinder temperature in the same production facility of a long fiber reinforced resin as used in the example 1, PA/PPE1 was fed through the extruder feeding port, molten at a screw rotation speed of 300 rpm and filled in the dipping bath with resin impregnating rolls. Meanwhile, 2 long-fiber glass fiber rovings of 2,400 tex with fiber diameter of 17 μm (ER2400T-448N by Nippon Electric Glass Co., Ltd.) were introduced from a roving supply stand into the dipping bath with resin impregnating rolls, where the molten resin in the dipping bath was impregnated into the long-fiber glass fiber rovings, which were then continuously drawn out through a nozzle part (diameter 2.7 mm) of the dipping bath at the drawing speed of 15 m/min forming a single strand, cooled and solidified in a water bath, passed through twisting rolls for twisting varyingly the resin strand allowing to form twists of various lead lengths, and then cut by a pelletizer to 10 mm pellet length. Thereby the set temperature of the dipping bath was 300° C.
Thereby, the extrusion rate of the extruder was so regulated that the glass fiber content became about 50% by mass. The glass fiber content determined according to the later measurement of ash was 54% by mass.
Example 24 to Example 29 were different only in strength of twisting, and all other conditions were the same. The strength of twisting was changed by changing the rotation speed of the rolls of a twister placed between the water bath and the pelletizer.
Using the obtained resin pellets and strands, evaluations were conducted. The results are shown in Table 5. Thereby, blend of a long fiber filler reinforced pellet and a pellet without a long fiber filler was not conducted as in the example 1, the long fiber filler reinforced pellet was injection-molded singly and the properties were evaluated.
Except that the set temperature of the dipping bath was set at 280° C., all others were conducted identically as in the example 26. The results are shown in Table 5.
Setting at 320° C. the extruder cylinder temperature in the same production facility of a long fiber reinforced resin as used in the example 1, PA/PPE2 was fed through the extruder feeding port, molten at a screw rotation speed of 300 rpm and filled in the dipping bath with resin impregnating rolls. As in the example 24 to example 29, long-fiber glass fiber rovings were introduced into the dipping bath with resin impregnating rolls, where the molten resin in the dipping bath was impregnated into the long-fiber glass fiber rovings, which were then continuously drawn out through a nozzle part (diameter 2.9 mm) of the dipping bath at the drawing speed of 23 m/min forming a single strand, cooled and solidified in a water bath, passed through twisting rolls for twisting varyingly the resin strand allowing to form twists of various lead lengths, and then cut by a pelletizer to 10 mm pellet length. Thereby the set temperature of the dipping bath was 330° C.
Thereby, the extrusion rate of the extruder was so regulated that the glass fiber content became about 50% by mass. The glass fiber content determined according to the later measurement of ash was 47% by mass.
Example 31 to Example 33 were different only in strength of twisting, and all other conditions were the same. The strength of twisting was changed by changing the rotation speed of the rolls of a twister placed between the water bath and the pelletizer.
Using the obtained resin pellets and strands, evaluations as in the example 24 to example 29 were conducted. The results are shown in Table 5.
Except that the resin to be fed through the feeding port of the extruder was changed to those described in Table 5, all others were performed and evaluated identically with the example 26. The results are shown in Table 5.
As obvious from the results in Table 5, all the pellets of the long fiber filler reinforced resins of Examples had excellent wettability, could extremely suppress longitudinal pellet fracture during transportation and detachment of the long fiber filler from the pellet, were superior in pellet appearance and were superior in fibrillation property of the long fiber filler during molding, enabling to mold a molded article with very high heat resistance and impact resistance.
On the other hand, in any of the examples 24, 28, 31 and 33, in which the spiral leads were outside the range of 20 mm to 80 mm, and the example 29 without twisting, the pellets were not well-balanced in all of longitudinal fracture, detachment, appearance and fibrillation property of the pellet.
In the example 36, in which polyphenylene ether was not contained, the fibrillation property was not sufficient and the molded article did not have sufficient strength in impact resistance.
Setting at −290° C. to 310° C. the cylinder temperature in the same production facility of a long fiber reinforced resin as used in the example 1, PPS/PPE1 to PPS/PPE16 as described in Table 6 and Table 7 were fed through the extruder feeding port, molten at a screw rotation speed of 300 rpm and filled in the dipping bath with resin impregnating rolls. Meanwhile, 2 long-fiber glass fiber rovings of 2,400 tex with fiber diameter of 17 μm (ER2400T-448N by Nippon Electric Glass Co., Ltd.) were introduced from a roving supply stand into the dipping bath with resin impregnating rolls, where the molten resin in the dipping bath was impregnated into the long-fiber glass fiber rovings, which were then continuously drawn out through a nozzle part (diameter 3.2 mm) of the dipping bath at the drawing speed of 20 m/min forming a single strand, cooled and solidified in a water bath, passed through twisting rolls for twisting varyingly the resin strand allowing to form twists of various lead lengths, and then cut by a pelletizer to 10 mm pellet length. Thereby the set temperature of the dipping bath was 310° C.
Thereby, the extrusion rate of the extruder was so regulated that the glass fiber content became about 40% by mass. The glass fiber content determined according to the later measurement of ash was 39% by mass.
Using the obtained resin pellets and strands, evaluations itemized in Table 6 and Table 7 were conducted. The results are shown in Table 6 and Table 7. Thereby, blend of a long fiber filler reinforced pellet and a pellet without a long fiber filler was not conducted as in the example 1, the long fiber filler reinforced pellet was injection-molded singly and the properties were evaluated.
As obvious from the results in Table 6 and Table 7, all the pellets of the long fiber filler reinforced resins of Examples had excellent wettability, could extremely suppress longitudinal pellet fracture during transportation and detachment of the long fiber filler from the pellet, were superior in pellet appearance and were superior in fibrillation property of the long fiber filler during molding, enabling to mold a molded article with very high heat resistance and impact resistance.
On the other hand, in any of the examples 43 and 44, in which the spiral leads were outside the range of 20 mm to 80 mm, and the examples 50 to 52, in which the cross-section of the core part exceeded 70% of the pellet cross-section, detachment from pellets occurred in a large amount, longitudinal pellet fracture occurred in many pellets, and surface appearances of the pellets were not glossy.
In the example 53, in which polyphenylene ether was not contained, the fibrillation property was not sufficient and the molded article did not have sufficient strength in impact resistance, etc.
Setting at 330° C. the cylinder temperature in the same production facility of a long fiber reinforced resin as used in the example 1, LCP/PPE1 was fed through the extruder feeding port, molten at a screw rotation speed of 300 rpm and filled in the dipping bath with resin impregnating rolls. Meanwhile, 2 long-fiber glass fiber rovings of 2,400 tex with fiber diameter of 17 μm (ER2400T-448N by Nippon Electric Glass Co., Ltd.) were introduced from a roving supply stand into the dipping bath with resin impregnating rolls, where the molten resin in the dipping bath was impregnated into the long-fiber glass fiber rovings, which were then continuously drawn out through a nozzle part (diameter 2.7 mm) of the dipping bath at the drawing speed of 22 m/min forming a single strand, cooled and solidified in a water bath, passed through twisting rolls for twisting varyingly the resin strand allowing to form twists of various lead lengths, and then cut by a pelletizer to 10 mm pellet length. Thereby the set temperature of the dipping bath was 330° C. The strength of twisting was changed by changing the rotation speed of the rolls of a twister placed between the water bath and the pelletizer.
Thereby, the extrusion rate of the extruder was so regulated that the glass fiber content became about 50% by mass.
Using the obtained resin pellets and strands, various evaluations were conducted. The results are shown in Table 8. Thereby, measurements of Charpy impact strength, flexural strength and high load DTUL were conducted by dry-blending 60 parts by mass of the obtained long fiber reinforced pellet and 40 parts by mass of LCP/PPE1 pellet, then molding them under the conditions of cylinder temperature at 330° C. and a mold temperature at 110° C., and conducting evaluations thereof. The results are shown in Table 8.
Using LCP/PPE2 instead of LCP/PPE1, procedures identical with the example 55 were performed to obtain a long fiber filler reinforced resin pellet. Then, 60 parts by mass of the obtained long fiber reinforced pellet and 40 parts by mass of the pellet of LCP/PPE1 were dry-blended and molded under the conditions of the cylinder temperature at 330° C. and the mold temperature at 110° C. The properties of the molded specimen were evaluated. The results are shown in Table 8.
Using chopped strand glass fiber (the surface being treated by a similar compound as for the long-fiber glass fiber) with filament diameter of 17 μm and fiber length of 3 mm, a composite pellet composed of the same resin composition as LCP/PPE1 and 30% by mass of chopped strand glass fiber was prepared. Thereby using the extruder used for preparing LCP/PPE1 and setting the maximum set temperature of the cylinder at 330° C., the resin components were fed through the upstream feeding port, and the chopped strand glass fiber was fed through the downstream feeding port, and melt-extruded. The stand was cut to obtain a composite pellet with length of about 3 mm and diameter of about 3 mm. By preparing a composite pellet having the same composition with the test specimen used for measuring the properties of a molded article of the example 54 to example 58, Charpy impact strength, flexural strength and high load DTUL were measured. The results are shown in Table 8.
Setting at 330° C. the extruder cylinder temperature in the same production facility of a long fiber reinforced resin as used in the example 54 to example 58, LCP/PPE3 was fed through the extruder feeding port, molten at a screw rotation speed of 300 rpm and filled in the dipping bath with resin impregnating rolls. As in the example 54 to example 58, long-fiber glass fiber rovings were introduced into the dipping bath with resin impregnating rolls, where the molten resin in the dipping bath was impregnated into the long-fiber glass fiber rovings, which were then continuously drawn out through a nozzle part (diameter 2.7 mm) of the dipping bath at the drawing speed of 15 m/min forming a single strand, cooled and solidified in a water bath, passed through twisting rolls for twisting the resin strand to form a twist with a lead length of 30 mm, and then cut by a pelletizer to 10 mm pellet length. Thereby the set temperature of the dipping bath was 320° C.
Thereby, the extrusion rate of the extruder was so regulated that the glass fiber content became about 50% by mass. The glass fiber content determined according to the later measurement of ash was 52.5% by mass.
Using the obtained resin pellets and strands, the evaluations as in the example 54 to example 58 were conducted. Thereby, the evaluations of impact strength and DTUL of a molded specimen were conducted by: pellet-blending 57 parts by mass of the long fiber filler reinforced resin pellet obtained in the present example and 43 parts by mass of LCP/PPE3 pellet to make the glass fiber content at 30% by mass; then molding the blend; and conducting similarly measurements thereof. The results are shown in Table 8.
Except setting the cylinder temperature of the extruder at 300° C., the screw rotation speed at 150 rpm and the temperature of the dipping bath at 290° C., all others were performed identically with the example 61 to obtain a long fiber filler reinforced resin pellet. The results are shown in Table 8.
Except that LCP/PPE4 was used instead of LCP/PPE1 in the example 56, all others were performed identically with the example 56. Using the obtained resin pellet and strand evaluations were conducted. The results are shown in Table 8.
Except that PEEK/PPE was used instead of LCP/PPE1 in the example 56, and that the set temperature of the dipping bath was set at 380° C., all others were performed identically with the example 56. Using the obtained resin pellet and strand evaluations were conducted. The results are shown in Table 8.
As obvious from the results in Table 8, all the pellets of the long fiber filler reinforced resins of Examples had excellent wettability, could extremely suppress longitudinal pellet fracture during transportation and detachment of the long fiber filler from the pellet, were superior in pellet appearance and were superior in fibrillation property of the long fiber filler during molding, enabling to mold a molded article with very high heat resistance and impact resistance.
On the other hand, in the examples 54 and 58, in which the spiral leads were outside the range of 20 mm to 80 mm, the surface appearance of the pellet was not glossy.
In the example 60, in which chopped strand glass fiber was used instead of the long fiber filler, such properties of a molded article as impact strength, flexural strength and heat resistance were found to be extremely inferior and insufficient.
Except that only LCP-1 was used instead of LCP/PPE1 in the example 56, all others were performed identically with the example 56. Using the obtained resin pellet, Charpy impact value was measured to obtain a mean value of 16 J (N=10). The dispersion of the values was about ±4 J with respect to the mean value (12 J to 20 J). On the other hand the dispersion in the example 56 was ±2 J with respect to the mean value.
Further, by observing the molded specimen after burning, almost all the glass fibers were found existing in an unfibrillated bundle form and no form retainability was recognized.
Comparison between the respective Examples and Comparative Examples described in Table 3 to Table 8 above reveals that in the Embodiment addition of polyphenylene ether to a thermoplastic resin other than polyphenylene ether increases extremely the fibrillation property of a long fiber filler and further improves substantially the quality stability of physical properties.
The above can be attributable to alloying of polyphenylene ether, which improves the fibrillation property of the long fiber filler, resulting in the quality stability of the thermoplastic resin blend.
The cylinder temperature of an extruder in a production facility of a long fiber reinforced resin, which was a co-rotating twin screw extruder (ZSK25: Coperion) provided with an upstream feeding port, a downstream feeding port and a dipping bath with resin impregnating rolls (Kobe Steel, Ltd.) at the front end of the co-rotating twin screw extruder, was set at 320° C., and according to the composition described in Table 8 a mixture of 100 parts by mass of PS/PPE4, 1.0 part by mass of Irg1098 and 1 part by mass of Zinc sulfide as a white colorant was fed through the upstream extruder feeding port, and 13 parts by mass of FR-2 based on 100 parts by mass of PS/PPE4 were fed through the downstream feeding port, and molten and blended at a screw rotation speed of 300 rpm to fill the dipping bath with resin impregnating rolls with the molten resin. Meanwhile, 2 long-fiber glass fiber rovings of 2,400 tex with filament diameter of 17 μm (using a polyurethane resin as a binder) were introduced from a roving supply stand to the dipping bath with resin impregnating rolls, where the molten resin in the dipping bath was impregnated into the long-fiber glass fiber rovings, which were then continuously drawn out through a nozzle (diameter 3.2 mm) part of the dipping bath at the drawing speed of 40 m/min forming a single strand, cooled and solidified in a water bath, passed through twisting rolls for twisting the resin strand to form a twist with a lead length of 30 mm to obtain a resin strand. Thereby, the extrusion rate of the extruder was so regulated that the glass fiber content became about 40% by mass.
The flame retardancy and the color tone of the obtained strand of the long fiber filler reinforced resin were observed. For a comparison, the flame retardancy and the color tone without use of Irg1098 and FR-2 are also shown in Table 9. Thereby the flame retardancy of a strand of a long fiber filler reinforced resin was judged by: whether a resin strand cut to 10 cm length contacted for 5 sec with the flame defined for the vertical burn test of UL94 should self-extinguish after removing the flame. If self-extinguished, the time required until the extinguishment was recorded. The color tone was judged visually. The results are shown in Table 9.
Replacing all of PS/PPE4 in the example 66 with PP/PPE2, PA/PPE3, PPS/PPE6 and LCP/PPE4 respectively, the example 67 to example 70 were carried out. The then temperatures of the extruder cylinder and the dipping bath are shown in Table 9 respectively. The flame retardancy and the color tone of the obtained strand were evaluated as in the example 66. The results are shown in Table 9.
In Table 9 are shown the properties of the pellet and the strand of the long fiber filler reinforced resin obtained in the example 66 to the example 70. To make clearer the effect by comparing the properties of the strands, the properties of the composition without an stabilizer and a flame retardant are shown in the lower rows. They demonstrate that the inclusion of a flame retardant and a stabilizer, although they are otherwise conducted under identical conditions, improves the flame retardancy and further the color tone.
This application is base on Japanese Patent Application No. 2007-87117 applied on 2007 Mar. 29, Japanese Patent Application No. 2007-218349 applied on 2007 Aug. 24, and Japanese Patent Application No. 2007-223267 as well as Japanese Patent Application No. 2007-223272 applied on 2007 Aug. 29, and the content thereof are herein incorporated by reference.
The present invention can provide a long fiber filler reinforced resin pellet, having good wettability between a long fiber filler and a thermoplastic resin, extremely suppressing longitudinal fracture of a pellet during transportation and detachment of a long fiber filler from a pellet, showing good appearance, and having superior fibrillation property of a long fiber filler during molding, enabling to mold a molded article with extremely high heat resistance and impact resistance.
The present invention can be favorably applicable to, for example, electrical/electronic parts, OA parts, machine parts, and automobile exterior/interior parts.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-049469 | Feb 2006 | JP | national |
This application is a continuation-in-part of International Application No. PCT/JP2007/052001 filed on Feb. 6, 2007 claiming benefit of priority of Japanese Patent Application No. 2006-049469 applied on Feb. 27, 2006 in Japan, and the entire disclosure of International Application No. PCT/JP2007/052001 is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2007/052001 | Feb 2007 | US |
| Child | 12181461 | US |
