Thermosetting resin composition, cured product, and molded article

Abstract

Provided are: a thermosetting resin composition which is capable of providing a cured product and a molded article that have excellent tracking resistance; and a cured product and a molded article which have excellent tracking resistance. The present invention relates to a thermosetting resin composition in which the content of an allyl polymer that has a constituent unit based on an allyl compound represented by formula (1) is 80 mass% or more in 100 mass% of a resin. (1): X-(COOCH2CH=CH2)n (In formula (1), n represents an integer of 2 to 4; and X represents an n-valent aromatic hydrocarbon group which may have an alkyl group or an n-valent alicyclic hydrocarbon group which may have an alkyl group.)

Description

Thermosetting resin compositions, cured products, molded products

[0001] This invention relates to thermosetting resin compositions, cured products, and molded articles.

[0002] Recently, encapsulating resins have come into use in electronic components such as capacitors, coils, and resistors to improve reliability and productivity. The required performance of encapsulating resins varies depending on the shape and size of the electronic component, but physical properties include moisture resistance, low stress resistance, high thermal conductivity, and impact resistance. Thermosetting resins such as diallyl phthalate resin and unsaturated polyester resin are used to satisfy these performance requirements.

[0003] For example, Patent Document 1 discloses a thermosetting resin composition using an unsaturated polyester resin, a diallyl 1,2-cyclohexanedicarboxylic acid homopolymer, and a diallyl phthalate homopolymer as resins.

[0004] International Publication No. 2019 / 039185

[0005] As a result of diligent research by the present inventors, it has been newly discovered that there is room for improvement in the tracking resistance of cured products and molded articles obtained by the composition described in Patent Document 1. The object of the present invention is to provide a thermosetting resin composition that can provide cured products and molded articles with excellent tracking resistance, and cured products and molded articles with excellent tracking resistance.

[0006] As a result of diligent research, the inventors of the present invention have found that a thermosetting resin composition in which the content of an allyl polymer having a structural unit based on an allyl compound represented by formula (1) is 80% by mass or more in 100% by mass of resin can provide cured products and molded articles with excellent tracking resistance, and have completed the present invention. X-(COOCH ２ CH=CH ２ ) ｎ (1) [In formula (1), n ​​represents an integer from 2 to 4, and X is an n-valent aromatic hydrocarbon group which may have an alkyl group, or an n-valent alicyclic hydrocarbon group which may have an alkyl group.]

[0007] Item 1 A thermosetting resin composition in which the content of an allyl polymer having a structural unit based on an allyl compound represented by formula (1) is 80% by mass or more of the resin by mass. X-(COOCH ２ CH=CH ２ ) ｎ (1) [In formula (1), n ​​represents an integer of any number from 2 to 4, and X is an n-valent aromatic hydrocarbon group which may have an alkyl group or an n-valent alicyclic hydrocarbon group which may have an alkyl group.] Item 2 The thermosetting resin composition according to Item 1, wherein X in formula (1) is an n-valent alicyclic hydrocarbon group which may have an alkyl group. Item 3 The thermosetting resin composition according to Item 1, wherein X in formula (1) is a divalent or trivalent alicyclic hydrocarbon group which may have an alkyl group. Item 4 The thermosetting resin composition according to Item 1, wherein the allyl compound represented by formula (1) is at least one selected from the group consisting of compounds of the following general formulas (13) to (20). [In the formula, n is an integer of any one of 2 to 4.] Item 5 A thermosetting resin composition according to any one of Items 1 to 4, wherein the content of the allyl polymer in 100% by mass of the resin is 90% by mass or more. Item 6 A thermosetting resin composition according to any one of Items 1 to 4, wherein the content of the allyl polymer in 100% by mass of the resin is 95% by mass or more. Item 7 A thermosetting resin composition according to any one of Items 1 to 4, wherein the content of the allyl polymer in 100% by mass of the resin is 98% by mass or more. Item 8 A thermosetting resin composition according to any one of Items 1 to 7, further containing an initiator. Item 9 A thermosetting resin composition according to any one of Items 1 to 8, further containing an inorganic filler. Item 10 A cured product obtained by thermosetting the thermosetting resin composition according to any one of Items 1 to 9. Item 11 A molded article characterized by being formed by molding the thermosetting resin composition according to any one of Items 1 to 9.

[0008] The thermosetting resin composition of the present invention contains 80% by mass or more of an allyl polymer having a structural unit based on an allyl compound represented by formula (1) in 100% by mass of the resin, and therefore can provide cured products and molded articles with excellent tracking resistance.

[0009] The thermosetting resin composition of the present invention has a content of an allyl polymer having a structural unit derived from the allyl compound represented by formula (1) of 80% by mass or more based on 100% by mass of the resin, and thus can provide a cured product or a molded article excellent in tracking resistance. X-(COOCH ２ CH=CH ２ ) ｎ (1) [In formula (1), n represents any integer of 2 to 4, and X is an n-valent aromatic hydrocarbon group optionally having an alkyl group or an n-valent alicyclic hydrocarbon group optionally having an alkyl group.]]

[0010] The reason why the above-mentioned effects are obtained is not necessarily clear, but it is presumed to be due to the following mechanism. As shown in the Examples and Comparative Examples of the present application, for a thermosetting resin composition in which the content of the allyl polymer is 0% by mass based on 100% by mass of the resin, a thermosetting resin composition in which the content of the allyl polymer is 30% by mass based on 100% by mass of the resin, and a thermosetting resin composition in which the content of the allyl polymer is 70% by mass based on 100% by mass of the resin, although there is room for improvement in the tracking resistance of the obtained cured products and molded articles, the thermosetting resin composition in which the content of the allyl polymer is 80% by mass or more based on 100% by mass of the resin can provide a cured product or a molded article excellent in tracking resistance. This is presumed to be because the main chain of the unsaturated polyester resin is an ester bond, so it is hydrolyzed and degraded by the electrolyte in a tracking resistance test under high voltage, whereas the allyl polymer does not contain an ester bond in its main chain, so degradation is less likely to occur.

[0011] The thermosetting resin composition of the present invention not only provides excellent tracking resistance in the obtained cured product and molded article, but also achieves good heat resistance and fluidity while maintaining good tracking resistance.

[0012] <Allyl Polymer> In the thermosetting resin composition of the present invention, the content of the allyl polymer having a structural unit derived from the allyl compound represented by formula (1) (also referred to as the allyl polymer of the present invention or allyl polymer) is 80% by mass or more based on 100% by mass of the resin. X-(COOCH ２ CH=CH ２ ) ｎ(1) [In formula (1), n ​​represents an integer from 2 to 4, and X is an n-valent aromatic hydrocarbon group which may have an alkyl group, or an n-valent alicyclic hydrocarbon group which may have an alkyl group.]

[0013] The allyl polymer of the present invention is obtained by polymerizing an allyl compound represented by formula (1). This yields an allyl polymer having a structural unit based on the allyl compound represented by formula (1). The n-valence is based on the number of COOH groups bonded to X, and in formula (1), the number of -COOH groups bonded to X is n. ２ CH=CH ２ This refers to the number of substituents. Furthermore, as is clear from the fact that the bonding of other substituents is not excluded, the expression "n-valent aromatic hydrocarbon group which may have an alkyl group" does not exclude the configuration in which substituents other than alkyl groups are bonded to the aromatic hydrocarbon group, but it does not have to have substituents other than alkyl groups. Similarly, the expression "n-valent alicyclic hydrocarbon group which may have an alkyl group" does not exclude the configuration in which substituents other than alkyl groups are bonded to the alicyclic hydrocarbon group, but it does not have to have substituents other than alkyl groups.

[0014] <<Allyl compounds represented by formula (1)>> The allyl compounds represented by formula (1) will be explained below. The allyl compounds represented by formula (1) may be used alone or in combination of two or more. X-(COOCH) ２ CH=CH ２ ) ｎ (1) [In formula (1), n ​​represents an integer from 2 to 4, and X is an n-valent aromatic hydrocarbon group which may have an alkyl group, or an n-valent alicyclic hydrocarbon group which may have an alkyl group.]

[0015] <<<When X is an n-valent aromatic hydrocarbon group which may have an alkyl group>>> The n-valent aromatic hydrocarbon group is preferably any aromatic hydrocarbon group having 6 to 20 carbon atoms, and more preferably any aromatic hydrocarbon group having 6 to 12 carbon atoms. n is preferably 2 or 3, and more preferably 2.

[0016] If X is an n-valent aromatic hydrocarbon group which may have an alkyl group, then the allyl ester (COOCH) on the ring ２ CH=CH ２ The substitution positions of the groups may be any combination, or a mixture thereof. In particular, two COOCH ２ CH=CH ２ When the group is bonded to a six-membered ring, two COOCH groups ２ CH=CH ２ The group may be ortho-oriented (disubstituted at positions 1 and 2), meta-oriented (disubstituted at positions 1 and 3), or para-oriented (disubstituted at positions 1 and 4), but ortho-oriented (disubstituted at positions 1 and 2) or meta-oriented (disubstituted at positions 1 and 3) is preferred, and meta-oriented (disubstituted at positions 1 and 3) is more preferred.

[0017] The n-valent aromatic hydrocarbon group may or may not have an alkyl group. The alkyl group may be a straight or branched chain having 1 to 10 carbon atoms, preferably having 1 to 5 carbon atoms, and more preferably a methyl group or an ethyl group. One or more alkyl groups may be present at the substituted positions of the aromatic hydrocarbon group. Furthermore, the n-valent aromatic hydrocarbon group may or may not have substituents other than alkyl groups.

[0018] When X is an n-valent aromatic hydrocarbon group which may have an alkyl group, specific allyl compounds represented by the above formula (1) include diallyl phthalate, diallyl isophthalate, and diallyl terephthalate, with diallyl phthalate and diallyl isophthalate being preferred, and diallyl isophthalate being more preferred.

[0019] Hereinafter, when X is an n-valent aromatic hydrocarbon group which may have an alkyl group, the allyl compound represented by the above formula (1) may be referred to as an "aromatic allyl compound".

[0020] When X is an n-valent aromatic hydrocarbon group which may have an alkyl group, the allyl compound represented by formula (1) above may be purchased commercially or synthesized by known synthetic methods (for example, the method described in International Publication No. 2019 / 039185).

[0021] <<<When X is an n-valent alicyclic hydrocarbon group which may have an alkyl group>>> The number of carbon atoms forming the ring structure of the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 4 to 12, even more preferably 4 to 10, and particularly preferably 5 to 7. The n-valent alicyclic hydrocarbon group may be a saturated n-valent alicyclic hydrocarbon group and may have unsaturated bonds in part, but it is preferable to be a saturated n-valent alicyclic hydrocarbon group. That is, the number of unsaturated bonds is preferably 2 or less, more preferably 1 or less, and particularly preferably 0. In this invention, alicyclic means having a cyclic structure which does not have an aroma, and alicyclic hydrocarbon group means a hydrocarbon group which has a cyclic structure which does not have an aroma. The number of rings is preferably 1 or 2, particularly preferably 1, but it may be 3 or more. When the number of rings is 2 or more, it may be a fused ring type, a bridging ring type, or it may have both a fused ring and a bridging ring structure, but it is preferable to have a bridging ring. n is preferably 2 or 3, and more preferably 2.

[0022] Furthermore, the n-valent alicyclic hydrocarbon group may or may not have an alkyl group. The alkyl group may be a straight or branched chain having 1 to 10 carbon atoms, preferably having 1 to 5 carbon atoms, and more preferably a methyl group or an ethyl group. One or more alkyl groups may be present at the substituted positions of the alicyclic hydrocarbon group. Moreover, the n-valent alicyclic hydrocarbon group may or may not have substituents other than alkyl groups.

[0023] When X is an n-valent alicyclic hydrocarbon group which may have an alkyl group, specific examples of allyl compounds represented by the above formula (1) include the compounds of the following general formulas (13) to (20) (formulas (15) to (18) are particularly preferred).

[0024] [In the formula, n is an integer between 2 and 4.]

[0025] In equations (13) to (20), the ring structure may be bridged, and examples of materials that are bridged within the ring structure include adamantane and norbornane.

[0026] If X is an n-valent alicyclic hydrocarbon group which may have an alkyl group, then COOCH on the ring ２ CH=CH ２ The substitution positions of the groups may be any combination, or a mixture thereof. In particular, two COOCH ２ CH=CH ２ When the group is bonded to a six-membered ring, two COOCH groups ２ CH=CH ２ The group may be ortho-oriented (disubstituted at positions 1 and 2), meta-oriented (disubstituted at positions 1 and 3), or para-oriented (disubstituted at positions 1 and 4), but ortho-oriented (disubstituted at positions 1 and 2) or para-oriented (disubstituted at positions 1 and 4) is preferred, and ortho-oriented (disubstituted at positions 1 and 2) is more preferred.

[0027] When X is an n-valent alicyclic hydrocarbon group which may have an alkyl group, specific allyl compounds represented by the above formula (1) include diallyl cyclobutanedicarboxylate, diallyl cyclopentanedicarboxylate, diallyl cyclohexanedicarboxylate (diallyl hexahydrophthalate, more specifically, 1,2-diallyl cyclohexanedicarboxylate, 1,3-diallyl cyclohexanedicarboxylate, 1,4-diallyl cyclohexanedicarboxylate), diallyl norbornanedicarboxylate, diallyl cyclobutenedicarboxylate, diallyl cyclopentenedicarboxylate, diallyl cyclohexenedicarboxylate (diallyl tetrahydrophthalate), and diallyl norbornenedicarboxylate, 3-methyl-hexahydro-1,2-diallylphthalate Examples include 4-methyl-hexahydro-1,2-diallyl phthalate, 3-methyl-1,2,3,6-tetrahydro-1,2-diallyl phthalate, 4-methyl-1,2,3,6-tetrahydro-1,2-diallyl phthalate, 3,6-endomethylene-3-methyl-hexahydro-1,2-diallyl phthalate, 3,6-endomethylene-4-methyl-hexahydro-1,2-diallyl phthalate, 3,6-endomethylene-3-methyl-1,2,3,6-tetrahydro-1,2-diallyl phthalate, 3,6-endomethylene-4-methyl-1,2,3,6-tetrahydro-1,2-diallyl phthalate, 4-cyclohexene-1,2-dicarboxylic acid diallyl, and 2-cyclohexene-1,2-dicarboxylic acid diallyl. Among these, 1,2-cyclohexanedicarboxylate diallyl, 3-methyl-hexahydro-1,2-diallyl phthalate, and 4-methyl-hexahydro-1,2-diallyl phthalate are preferred, with 1,2-cyclohexanedicarboxylate diallyl being more preferred.

[0028] Hereinafter, when X is an n-valent alicyclic hydrocarbon group which may have an alkyl group, the allyl compound represented by the above formula (1) may be referred to as an "alicyclic allyl compound".

[0029] When X is an n-valent alicyclic hydrocarbon group which may have an alkyl group, the allyl compound represented by the above formula (1) may be a commercially available product purchased for use, or may be synthesized by a known synthesis method (for example, the method described in International Publication No. WO2019 / 039185).

[0030] <<<Regarding Allyl Polymers>>> The method for synthesizing an allyl polymer by polymerizing an allyl compound represented by formula (1) is not particularly limited, and the allyl polymer can be synthesized, for example, by appropriately changing the monomer used in accordance with the method for synthesizing a homopolymer described in International Publication No. WO2019 / 039185.

[0031] X is an n-valent aromatic hydrocarbon group which may have an alkyl group or an n-valent alicyclic hydrocarbon group which may have an alkyl group, and X is preferably an n-valent alicyclic hydrocarbon group which may have an alkyl group, and more preferably a divalent or trivalent alicyclic hydrocarbon group which may have an alkyl group. This tends to provide better tracking resistance.

[0032] In the allyl polymer of the present invention, among 100 mol% of structural units derived from the allyl compound represented by formula (1), the content of structural units derived from the allyl compound represented by formula (1) in which X is an n-valent alicyclic hydrocarbon group which may have an alkyl group is preferably 50 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, particularly preferably 95 mol% or more, most preferably 98 mol% or more, and may be 100 mol%. When the content is within the above range, the effect of the present invention tends to be obtained more sufficiently. In the present specification, the content of structural units in a polymer is measured by a nuclear magnetic resonance apparatus.

[0033] The allyl polymer of the present invention may have structural units other than those based on the allyl compound represented by formula (1). However, the content of structural units based on the allyl compound represented by formula (1) in 100 mol% of the allyl polymer of the present invention is preferably 50 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, particularly preferably 95 mol% or more, most preferably 98 mol% or more, and may be 100 mol%. Within the above range, the effects of the present invention tend to be obtained more fully.

[0034] The weight-average molecular weight (Mw) of the allyl polymer of the present invention is preferably 2,000 to 150,000, more preferably 5,000 to 140,000, and even more preferably 10,000 to 100,000. Within the above range, the effects of the present invention tend to be more fully obtained. In this specification, "weight-average molecular weight" can be determined by measuring it at 40°C using gel permeation chromatography (GPC system, manufactured by Shimadzu Corporation) and using a standard polystyrene calibration curve.

[0035] The thermosetting resin composition of the present invention contains the allyl polymer of the present invention. The allyl polymer of the present invention may be used alone or in combination of two or more types. The content of the allyl polymer of the present invention in 100% by mass of the thermosetting resin composition of the present invention may be in the range of 5 to 80% by mass, but the lower limit of the content of the allyl polymer of the present invention is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 20% by mass or more. The upper limit of the content of the allyl polymer of the present invention is preferably 75% by mass or less, more preferably 60% by mass or less, and even more preferably 45% by mass or less. Preferred ranges for the content of the allyl polymer of the present invention include 5 to 75% by mass, 5 to 60% by mass, 5 to 45% by mass, 10 to 75% by mass, 10 to 60% by mass, 10 to 45% by mass, 20 to 75% by mass, 20 to 60% by mass, and 20 to 45% by mass. Within the above ranges, the effects of the present invention tend to be obtained more fully.

[0036] The thermosetting resin composition of the present invention may contain polymers (resins) other than the allyl polymer of the present invention. The polymers (resins) other than the allyl polymer of the present invention that can be used in the thermosetting resin composition of the present invention are not particularly limited, and examples include unsaturated polyester resins, epoxy resins, phenolic resins, melamine resins, and the like. These may be used individually or in combination of two or more.

[0037] In the thermosetting resin composition of the present invention, the content of the allyl polymer of the present invention is 80% by mass or more of 100% by mass of the resin (polymer), preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 98% by mass or more, and may be 100% by mass. Within the above range, the effects of the present invention tend to be obtained more fully.

[0038] <Crosslinking Agent> The thermosetting resin composition of the present invention preferably contains a crosslinking agent. The crosslinking agent is not particularly limited as long as it is a polyfunctional compound, and examples include a polyfunctional monomer having two or more (meth)acryloyl groups or two or more allyl groups. These may be used alone or two or more may be used in combination. Among these, a polyfunctional monomer having two or more allyl groups is preferred. Here, (meth)acryloyl group means either or both of an acryloyl group and a methacryloyl group. The number of functional groups ((meth)acryloyl groups or allyl groups) that the crosslinking agent has is preferably 2 to 4, more preferably 2 to 3, and even more preferably 2, for the reason that the effects of the present invention can be more favorably obtained.

[0039] Examples of polyfunctional monomers having two or more allyl groups include polyfunctional allyl ester compounds such as the allyl compound represented by formula (1), as well as polyfunctional allyl ether compounds. Among these, polyfunctional allyl ester compounds are preferred, and allyl compounds represented by formula (1) are more preferred.

[0040] Polyfunctional allyl ether compounds may be purchased commercially or synthesized. Specific examples include ethylene glycol diallyl ether, 1,3-propylene glycol diallyl ether, 1,4-butanediol diallyl ether, 1,5-pentanediol diallyl ether, 1,6-hexanediol diallyl ether, 1,7-heptanediol diallyl ether, 1,8-octanediol diallyl ether, 1,9-nonanediol diallyl ether, 1,10-decanediol diallyl ether, trimethylolpropane diallyl ether, trimethylolpropane triallyl ether, pentaerythritol diallyl ether, pentaerythritol triallyl ether, pentaerythritol tetraallyl ether, glycerin diallyl ether, glycerin triallyl ether, dimethylolcyclohexane diallyl ether, bisphenol A diallyl ether, bisphenol F diallyl ether, bisphenol S diallyl ether, and novolacphenol allyl ethers. Among these, trimethylolpropanediallyl ether, pentaerythritol triallyl ether, and pentaerythritol tetraallyl ether are preferred, and trimethylolpropanediallyl ether and pentaerythritol triallyl ether are more preferred.

[0041] As polyfunctional monomers having two or more (meth)acryloyl groups, commercially available ones may be purchased and used, or synthesized ones may be used. Specific examples include ethylene glycol di(meth)acrylate, 1,3-propanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,5-pentanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,7-heptanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, tricyclodecanedimethanol diacrylate, and the like. In particular, 1,6-hexanediol di(meth)acrylate, 1,7-heptanediol di(meth)acrylate, 1,8-octanediol di(meth)acrylate, and 1,9-nonanediol di(meth)acrylate are preferred.

[0042] In the thermosetting resin composition of the present invention, the crosslinking agent content is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 1 part by mass or more, preferably 80 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 10 parts by mass or less, based on 100 parts by mass of the resin (polymer) (preferably the allyl polymer of the present invention) contained in the thermosetting resin composition of the present invention. Within the above range, the effects of the present invention tend to be obtained more fully.

[0043] <Initiators (Polymerization Initiators)> The thermosetting resin composition of the present invention preferably contains an initiator (polymerization initiator). Examples of polymerization initiators include dialkyl peroxides such as di-tert-butyl peroxide and dicumyl peroxide, diallyl peroxides, peroxyesters such as tert-butyl-peroxybenzoate, tert-butyl-peroxy-isopropyl carbonate peroxides, peroxyketals such as 1,1-di-tert-butyl-peroxycyclohexane, benzoyl peroxides, dialoyl peroxides such as 2,4-dichlorobenzoin peroxide, diacyl peroxides, hydroperoxides such as hydroperoxides, and azo compounds such as azobisisobutyronitrile. These may be used alone or in combination of two or more.

[0044] In the thermosetting resin composition of the present invention, the initiator content is preferably 0.1 to 20 parts by mass, and more preferably 1 to 10 parts by mass, per 100 parts by mass of the resin (polymer) (preferably the allyl polymer of the present invention) contained in the thermosetting resin composition of the present invention. Within the above range, the effects of the present invention tend to be obtained more fully.

[0045] <Inorganic Fillers> Inorganic fillers may be added to the thermosetting resin composition of the present invention as needed. Examples of inorganic fillers include hydrates of metals such as fused silica, crystalline silica, alumina, quartz glass, calcium carbonate, aluminum hydroxide, and calcium sulfate, glass powder, talc, and mica. These may be used alone or in combination of two or more. The particle size of the inorganic filler is 0.1 to 100 μm. Preferably, it is 0.5 to 60 μm. If the particle size is too small, the viscosity of the composition will be high, and the reinforcing fibers will not be sufficiently impregnated, making it easy for air to be mixed into the material and for molded products to be prone to voids. On the other hand, if the particle size is too large, the specific surface area of ​​the particles will be small, resulting in decreased fluidity.

[0046] In the thermosetting resin composition of the present invention, the inorganic filler content may be 10 to 1,000 parts by mass, and more preferably 30 to 800 parts by mass, per 100 parts by mass of the resin (polymer) (preferably the allyl polymer of the present invention) contained in the thermosetting resin composition of the present invention. Within the above range, the effects of the present invention tend to be obtained more fully.

[0047] In addition to the above components, the thermosetting resin composition of the present invention may contain components known in the art, such as fiber reinforcing agents, low-shrinkage agents, mold release agents, thickeners, pigments, viscosity reducers, and silane coupling agents, to the extent that they do not impair the effects of the present invention. These may be used individually or in combination of two or more.

[0048] The fiber reinforcing agent used in the present invention is not particularly limited, and any known in the art can be used. Examples of fiber reinforcing materials include various organic and inorganic fibers such as glass fibers, pulp fibers, Tetron® fibers, vinylon fibers, carbon fibers, aramid fibers, and wollastonite. Among these, it is preferable to use chopped strand glass cut to a fiber length of about 1.5 to 25 mm. These may be used alone or in combination of two or more types.

[0049] In the thermosetting resin composition of the present invention, the content of the fiber reinforcing agent may be 10 to 1,000 parts by mass, and more preferably 30 to 800 parts by mass, per 100 parts by mass of the resin (polymer) (preferably the allyl polymer of the present invention) contained in the thermosetting resin composition of the present invention. Within the above range, the effects of the present invention tend to be obtained more fully.

[0050] Examples of low-shrinkage agents used in the present invention include thermoplastic polymers commonly used as low-shrinkage agents, such as polystyrene, polymethyl methacrylate, polyvinyl acetate, saturated polyester, and styrene-butadiene rubber. These may be used individually or in combination of two or more.

[0051] Examples of release agents used in the present invention include stearic acid, zinc stearate, calcium stearate, aluminum stearate, magnesium stearate, and carnauba wax. These may be used individually or in combination of two or more.

[0052] Examples of thickening agents used in the present invention include metal oxides such as magnesium oxide, magnesium hydroxide, calcium hydroxide, and calcium oxide, as well as isocyanate compounds. These may be used individually or in combination of two or more.

[0053] The thermosetting resin composition of the present invention can be produced by methods commonly used in the art, such as kneading using a planetary mill or a kneader.

[0054] The thermosetting resin composition of the present invention can be used to produce molded products (cured products, molded articles) by molding it into a desired shape and curing it (thermosetting). The cured product of the present invention is obtained by thermosetting the thermosetting resin composition of the present invention. Furthermore, the molded article of the present invention is obtained by molding the thermosetting resin composition of the present invention. The molding and thermosetting methods are not particularly limited, and methods commonly used in the art, such as compression molding, transfer molding, injection molding, etc., can be used.

[0055] The present invention will be described in more detail below with reference to examples, but the present invention is not limited in any way by these examples.

[0056] The materials used in the examples and comparative examples described below are explained below.

[0057] MDAC: 1,2-Cyclohexanedicarboxylate diallyl (a compound represented by the following formula) Alicyclic diallyl resin (MDAC=100 homopolymer (AD-032)): "RADPAR AD-032" manufactured by Osaka Soda Co., Ltd. (a polymer of the above MDAC) DAPM: Diallyl phthalate (a compound represented by the following formula) UP: Unsaturated polyester 8524 (unsaturated polyester resin) manufactured by Nippon Yupika Co., Ltd. Silane coupling agent: KBM-503 manufactured by Shin-Etsu Silicone Co., Ltd. Glass fiber: CS 3 E-227 manufactured by Nitto Boseki Co., Ltd. Calcium carbonate: MC Coat S-1 manufactured by Maruo Calcium Co., Ltd. Calcium stearate: SC-100 manufactured by Sakai Chemical Industry Co., Ltd. Dicumyl peroxide: Percumyl D manufactured by NOF Corporation

[0058] Preparation of Thermosetting Resin Compositions According to the compositions shown in Tables 1 and 2, each material was pre-mixed, then melt-kneaded using a heated roll at 80-100°C, cooled, and pulverized to prepare thermosetting resin compositions.

[0059] The numerical units for composition in the table are parts by mass.

[0060] The obtained thermosetting resin compositions were evaluated as follows. The results are shown in Table 2.

[0061] Fluidity (Spiral Flow) Measurement: For each thermosetting resin composition, the longest length of the cured spiral-shaped portion, resembling a thin spiral mosquito coil, was measured. This length was defined as fluidity, and its change over time was measured. The measurements were performed under the following conditions: Molding machine: 37-ton transfer molding machine (Shinto Metal Industries Co., Ltd. "Transfer Molding Machine TA37"); Measurement mold: EMMI Spiral Flow (manufactured in-house by Osaka Soda); Measurement temperature: 150°C (mold temperature); Injection pressure: 8.5 MPa; Sample amount: 15 g; Pressurization time: 300 sec.

[0062] Measurement of 5% Weight Loss Temperature: Molded products were obtained by transfer molding of each thermosetting resin composition at a mold temperature of 160°C for a molding time of 4 minutes. Using a Hitachi High-Tech Science (TG / DTA STA7200RV) thermometer, the weight loss was measured in an air atmosphere at a heating rate of 10°C / min in the range of 30°C to 500°C. The mass before heating was set as 100%, and the temperature at which a 5% mass loss occurred from the mass before heating was defined as the 5% weight loss temperature.

[0063] Tracking Resistance Measurement Each thermosetting resin composition was compression molded at a mold temperature of 160°C for 6 minutes to obtain a molded product with a diameter of 150 mm and a thickness of 6 mm. The obtained molded product was cut into pieces measuring 120 mm x 50 mm x 6 mm using a cutting machine. The cut test pieces were measured in accordance with JIS C 2136 (constant tracking voltage application method, voltage 1500 V, endpoint reference A) using an inclined plate tracking resistance tester (Yamayo Testing Machine Co., Ltd. YST-587 model).

[0064]

[0065] As shown in Table 2, the thermosetting resin compositions of the examples, in which the content of an allyl polymer having a structural unit based on an allyl compound represented by formula (1) is 80% by mass or more of the resin, were found to be able to provide cured products and molded articles with excellent tracking resistance.

[0066] The present invention relates to a thermosetting resin composition that can provide cured products and molded products with excellent tracking resistance, as well as cured products and molded products with excellent tracking resistance. The thermosetting resin composition, cured products, and molded products of the present invention can be used, for example, in small, thin-walled coil bobbins, switch cases, terminal boards, connectors, magnetic switches and other electrical and electronic components, busbars, terminal blocks, power module cases (especially busbars, terminal blocks, and power module cases), etc., taking advantage of their excellent tracking resistance.

Claims

1. A thermosetting resin composition in which the content of an allyl polymer having a structural unit based on an allyl compound represented by formula (1) is 80% by mass or more of the resin by mass. X-(COOCH ２ CH=CH ２ ) ｎ (1) [In formula (1), n ​​represents an integer from 2 to 4, and X is an n-valent aromatic hydrocarbon group which may have an alkyl group, or an n-valent alicyclic hydrocarbon group which may have an alkyl group.] 2. The thermosetting resin composition according to claim 1, wherein X in formula (1) is an n-valent alicyclic hydrocarbon group which may have an alkyl group.

3. The thermosetting resin composition according to claim 1, wherein X in formula (1) is a divalent or trivalent alicyclic hydrocarbon group which may have an alkyl group.

4. The thermosetting resin composition according to claim 1, wherein the allyl compound represented by formula (1) is at least one selected from the group consisting of compounds of the following general formulas (13) to (20). [In the formula, n is an integer between 2 and 4.] 5. The thermosetting resin composition according to claim 1, wherein the allyl polymer content is 90% by mass or more in 100% by mass of the resin.

6. The thermosetting resin composition according to claim 1, wherein the allyl polymer content is 95% by mass or more in 100% by mass of the resin.

7. The thermosetting resin composition according to claim 1, wherein the allyl polymer content is 98% by mass or more in 100% by mass of the resin.

8. The thermosetting resin composition according to claim 1, further comprising an initiator.

9. The thermosetting resin composition according to claim 1, further comprising an inorganic filler.

10. A cured product obtained by thermosetting the thermosetting resin composition according to any one of claims 1 to 9.

11. A molded article characterized by being formed by molding a thermosetting resin composition according to any one of claims 1 to 9.

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