JP2001002741A - Thermosetting resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermosetting resin composition having small curing shrinkage factor during molding, and capable of giving a cured body exhibiting excellent thermal resistance and corrosion resistance. SOLUTION: This composition comprises (A) a vinyl ester resin, (B) an unsaturated polyester having a melting point or softening point in the range of 60-150 deg.C, (C) one or plural monomers selected from the group consisting of allyl ester monomers and (meth)acrylic acid ester monomers, (D) a thermoplastic polyester resin having a Tg of <=0 deg.C and (E) a radical polymerization initiator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosetting resin composition, and more particularly, to a thermosetting resin composition having a small curing shrinkage during molding and a cured product having excellent heat resistance and corrosion resistance. It is about things.

[0002]

2. Description of the Related Art In recent years, there has been a remarkable technological innovation led by the electronics industry, and the material technology supporting this technology has also made great strides. The development of polymer materials that play a role in materials is no exception, and many new or high-performance polymer materials have emerged, and their respective positions are being consolidated. The main properties required for polymer materials in the electronics field are moldability, heat resistance, durability, electrical properties, corrosion resistance, etc., and thermosetting resins represented by epoxy resins, phenol resins, etc., polyimides, Various engineering plastics represented by polycarbonate, polyphenylene oxide, and the like are frequently used.

There are, of course, strong demands for materials having various performances as listed above, but there are technically extremely difficult aspects and disadvantages in terms of price. One of such technical issues is the development of a polymer material that is a highly accurate molded body and has both heat resistance and corrosion resistance.

[0004] Since the thermoplastic resin is cooled and solidified from the surface first during molding, so-called sink phenomenon is inevitable during molding, and there are many problems as a material for obtaining a highly accurate molded product. On the other hand, thermosetting resins often involve large curing shrinkage during molding, which is also inconvenient for the purpose of the present invention.

[0005] Among the various types of thermosetting resins, unsaturated polyester resins use styrene as a solvent / monomer and a specific thermoplastic resin when used in combination.
Techniques for suppressing curing shrinkage during molding have been developed and put to practical use. However, the fact that the raw material resin composition contains styrene impairs the working environment at the time of molding and also reduces the heat resistance of the cured product. The cured unsaturated polyester resin has an essential weakness in terms of alkali resistance, and also has a weakness in a pressure cooker test.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a thermosetting resin composition having a small curing shrinkage during molding and having a cured product exhibiting excellent heat resistance and corrosion resistance.

[0007]

Means for Solving the Problems Based on a completely new viewpoint and hypothesis, the present inventors conducted an evaluation test of a large number of prototypes in search of an optimal thermosetting resin composition, and found that vinyl ester resin and vinyl ester resin were obtained. A system in which a specific unsaturated polyester, an allyl ester monomer and / or an acrylate ester monomer, and a thermoplastic polyester resin are combined,
It has been found that the object of the present invention can be achieved, and the present invention has been completed.

That is, the present invention provides (A) a vinyl ester resin, (B) an unsaturated polyester having a melting point or softening point in the range of 60 ° C. to 150 ° C., (C) an allyl ester monomer and (meth) acrylic acid. One or more monomers selected from the group consisting of ester monomers, and (D)
A thermoplastic polyester resin having a Tg of 0 ° C. or less;
(E) A thermosetting resin composition comprising a radical polymerization initiator. Further, the present invention provides (A)
The present invention provides the above thermosetting resin composition, wherein the vinyl ester resin as a component is a novolak vinyl ester resin. Further, the present invention provides the above thermosetting resin composition, wherein the allyl ester monomer as the component (C) is diallyl phthalate. In the present invention, the thermoplastic polyester resin of the component (D) may be adipic acid,
Azelaic acid, sebacic acid, dodecane diacid, or a mixture thereof, and the number average molecular weight is in the range of 5,000 to 50,000. Is what you do. Further, according to the present invention, the ratio of each component to the sum of the components (A), (B), (C), and (D) is as follows:
Component (A) is 10 to 80% by weight, component (B) is 2 to 40% by weight, component (C) is 10 to 60% by weight, component (D) is 2 to 15% by weight, and (A) The present invention provides the above thermosetting resin composition, wherein the sum of the component, the component (B), the component (C), and the component (D) is 100% by weight. The present invention also provides the above thermosetting resin composition, wherein the radical polymerization initiator of the component (E) is an organic peroxide or a photopolymerization initiator. Further, the present invention provides a composite material obtained by compounding the thermosetting resin composition according to any one of claims 1 to 6 with an equal amount or more of an inorganic filler by weight, and molding and curing the same. To provide.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION (A) Vinyl Ester Resin The vinyl ester resin of the component (A) in the present invention is not particularly limited, but a novolac vinyl ester resin is preferably used. General-purpose vinyl ester resins are produced by reacting bisphenol A-type glycidyl ether with acrylic acid or methacrylic acid, while novolak-based vinyl ester resins are produced using novolak-type glycidyl ether as a raw material. In a system in which styrene is not used as a solvent / monomer as in the present invention, it is difficult to reduce curing shrinkage by adding a thermoplastic resin to a general vinyl ester resin, and the copolymerizability with a monomer such as an allyl ester is not necessarily good. What cannot be said is also confirmed from a curing heat generation curve using, for example, DSC. The reason why the novolak-based vinyl ester resin is particularly preferred in the present invention is based on the fact that the curing shrinkage is relatively easily reduced and the copolymerizability with monomers such as allyl ester is also good, as described later. .

(B) Unsaturated Polyester In the present invention, (B) unsaturated polyester having a melting point or softening point in the range of 60 ° C. to 150 ° C. is used together with (A) vinyl ester resin. With an unsaturated polyester having a melting point or softening point of less than 60 ° C., the heat resistance of the cured product aimed at by the present invention becomes insufficient. When using an unsaturated polyester having a melting point or softening point exceeding 150 ° C.,
In some cases, the reproducibility of the strength of the thermosetting resin composition of the present invention after curing is unsatisfactory or does not reach a predetermined level.
Among the raw materials constituting the (B) unsaturated polyester, the following can be exemplified as the saturated polybasic acid. Selected from the group consisting of terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, cyclohexanedicarboxylic acid, biphenyldicarboxylic acid, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, chlorendic anhydride and esters thereof Kind,
Or a mixture of several species. As the unsaturated polybasic acid, fumaric acid is used, but as is generally used, it is also possible to use cis-type maleic anhydride to utilize the transition to fumaric acid at a high temperature. . Further, among the raw materials constituting the unsaturated polyester, the following can be exemplified as the polyhydric alcohol component. These halogen-substituted compounds can also be used for flame retardation. Butanediol, ethylene glycol, neopentyl glycol, cyclohexane dimethanol, hydrogenated bisphenol A, bisphenol A-ethylene oxide adduct, bisphenol A-propylene oxide adduct,
Cyclohexane dimethanol ethylene oxide adduct, bisphenol A, hydrogenated bisphenol A ethylene oxide adduct, hydrogenated bisphenol A propylene oxide adduct, diphenylethylene oxide adduct, norbornane dialcohol, tricyclodecane dimethanol or any of these A mixture of two or more. (B) The unsaturated polyester can be synthesized by a conventional method.

(C) Allyl ester monomer or (meth)
(T) Acrylic acid ester monomer As the allyl ester monomer of the component (C) in the present invention, diallyl orthophthalate, diallyl isophthalate, diallyl terephthalate, diallyl cyclohexanedicarboxylate and the like are exemplified, and preferably diallyl phthalate, More preferably, it is diallyl terephthalate, which can realize excellent heat resistance of the cured resin. Specific examples of the (meth) acrylate monomer of the component (C) are as follows. These halogen-substituted compounds can also be used for flame retardation. Phenoxyethyl methacrylate, isobornyl methacrylate, benzyl methacrylate, dicyclopentenyloxyethyl acrylate, dicyclopentenyloxyethyl methacrylate, trimethylolpropane diacrylate, trimethylolpropane dimethacrylate, trimethylolpropane triacrylate,
Trimethylolpropane trimethacrylate, trimethylolpropane tris-oxyethylene acrylate,
Trimethylolpropane tris-oxyethylene methacrylate, pentaerythritol tetraacrylate,
Pentaerythritol tetramethacrylate, glycerin diacrylate, glycerin dimethacrylate, 1,6-
Hexanediol diacrylate.

(D) Thermoplastic Polyester Resin The thermoplastic polyester resin of the component (D) in the present invention has a Tg of 0 ° C. or lower. (D) The thermoplastic polyester resin can be easily synthesized by a generally known esterification reaction of a dibasic acid and glycol as a by-product of water and, if necessary, a linkage of a reaction product with a polyisocyanate. It can also be synthesized by a transesterification reaction of dimethyl ester of dibasic acid and glycol with methanol as a by-product.
(D) The number average molecular weight of the thermoplastic polyester resin is 5,000
It is preferably from 0 to 50,000, and more preferably from 15,000 to 30,000.
(D) The number average molecular weight of the thermoplastic polyester resin is 5,000
In order to obtain 0 or more, some contrivance is required in the esterification reaction. For example, when the glycol component is slightly excessive, an initial esterification reaction is performed using a specific effective catalyst such as a titanium-based catalyst, and when the acid value falls below a certain value, deglycolation is further performed under high vacuum conditions of about 1 Torr. To carry out the reaction. According to this method, a much higher number average molecular weight, for example, about 20,000 can be obtained. In the present invention, the following can be exemplified as the glycol for constituting the thermoplastic polyester resin (D). Propylene glycol, 1,3-butylene glycol, 1,6-hexanediol, 2-methyl-1,3-propanediol, 1-methyl-1,3-propanediol, 3-methyl-1,5-pentanediol, 4-methyl-1,7-heptanediol, 2-methyl-1,6-hexanediol, 3-methyl-1,6-
Hexanediol, 1-methyl-1,6-hexanediol, 4
-Methyl-1,9-nonanediol, 2-methyl-1,9-nonanediol, 3-methyl-1,9-nonanediol, ethylene glycol, diethylene glycol, neopentyl glycol, 1,5-pentanediol. In the present invention, the following can be exemplified as (D) the dibasic acid for constituting the thermoplastic polyester resin. Phthalic anhydride, isophthalic acid, terephthalic acid, succinic acid, tetrahydrophthalic anhydride, heptic anhydride, adipic acid, azelaic acid,
Sebacic acid, dodecane diacid. Among these, as the thermoplastic polyester resin raw material (D), any of adipic acid, azelaic acid, sebacic acid and dodecane diacid or a mixture thereof is particularly preferable. In the present invention, the Tg of the thermoplastic polyester resin (D) is a commonly used Dg.
It can be easily measured by SC measurement. (D)
The Tg of the thermoplastic polyester resin is preferably 0 ° C or lower, and more preferably -10 ° C or lower. When Tg exceeds 0 ° C., the effect of reducing the curing shrinkage of the thermosetting resin composition of the present invention cannot be expected.

In the present invention, the ratio of each component to the sum of components (A), (B), (C) and (D) is as follows: component (A) is 10 to 80% by weight; Preferably 20 to
60% by weight, 2 to 40% by weight of component (B), preferably 3 to 30%
%, Component (C) is 10 to 60% by weight, preferably 20 to 50%.
% By weight, 2 to 15% by weight, preferably 3 to 10% by weight, and the sum of the components (A), (B), (C) and (D) is 100% by weight. Is good. When the amount of the component (A) is less than 10% by weight, the molding processability of the thermosetting resin composition becomes difficult, and the heat resistance and corrosion resistance of the cured resin tend to be poor. If the component (A) exceeds 80% by weight, the strength of the cured resin of the thermosetting resin composition may be poor. If the amount of the component (B) is less than 2% by weight, there is a problem in molding processability of the thermosetting resin composition, and the surface accuracy is deteriorated and the strength of the cured resin may be unsatisfactory. When the amount of the component (B) exceeds 40% by weight, the viscosity of the thermosetting resin composition becomes high, so that the processability is deteriorated and the corrosion resistance after curing may be unsatisfactory. If the content of the component (C) is less than 10% by weight, the strength, heat resistance and corrosion resistance of the cured product tend to be poor, and if it exceeds 60% by weight, the heat resistance of the cured product may be unsatisfactory. If the amount of the component (D) is less than 2% by weight, the curing shrinkage at the time of molding is insufficiently reduced, so that
If it exceeds 300, the corrosion resistance and heat resistance of the cured product may deteriorate. The fact that the component (A), the component (B) and the component (C) exhibit extremely good copolymerizability in the present invention is, for example, that DS
When the heat generation during polymerization is measured using a known measuring device such as C, it can be confirmed from the observation that a heat generation curve having a sharper shape and shifted to a lower temperature side than any of the single heat generation curves is observed. .

(E) Radical Polymerization Initiator In order to cure the thermosetting resin composition of the present invention, a curing method conventionally used for unsaturated polyesters, for example, UV curing using a photopolymerization initiator is also employed. Alternatively, heat curing can be performed using an organic peroxide. The following can be exemplified as the photopolymerization initiator. 2,2-dimethoxy-1,2-diphenylethan-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, bezophenone, 2-methyl-1- (4-methylthiophenyl) -2-monforinopropanone- 1,2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2-hydroxy-2-methyl-1
-Phenyl-propan-1-one, 2,4,6-trimethylbenzoyldiphenyl-phosphine oxide. As the organic peroxide, known compounds such as dialkyl peroxide, acyl peroxide, hydroperoxide, ketone peroxide, and peroxyester can be used, and specific examples include the following. . Benzoyl peroxide, t-butyl peroxy-2
-Ethyl hexanate, 2,5-dimethyl-2,5-di (2-ethylhexanoyl) peroxyhexane, t-butyl peroxybenzoate, t-butyl hydroperoxide, cumene hydroperoxide, dicumyl peroxide , Di-t-butyl peroxide, 2,5-dimethyl-2,5-dibutylperoxyhexane. The amount of the above (E) radical polymerization initiator to be used is 0.2 to 4 with respect to the thermosetting resin composition.
A range of about weight% is preferred.

Since the thermosetting resin composition of the present invention has a relatively low viscosity, various inorganic fillers as exemplified below are used as weight ratios (total of the components (A) to (D)). Even if it is compounded in equal amounts or more, workability can be sufficiently ensured, and as a result, it is also possible to achieve the purpose of reinforcement, increase in weight, etc., which is formed into a desired shape and cured. And a composite material. Silica, attapulgite, kaolin clay, volcanic ash, finely divided silica, calcium silicate, diatomaceous earth, magnesium oxide, titanium oxide, iron oxide, magnesium hydroxide, slate powder, sericite, quartz powder, calcium carbonate, talc, feldspar powder, barite, leeches Stone, whiting, mica, waxite clay, gypsum, various hydraulic cements.

In order to obtain the thermosetting resin composition of the present invention,
It is desirable to mix the components as uniformly as possible using a generally known mixing device such as a roll, kneader, Brabender, or Banbury mixer. At the time of compounding, it is preferable that all the components are uniformly mixed, and finally (E) a radical polymerization initiator is added and mixed. The obtained thermosetting resin composition can be formed into powder, granules, pellets, tablets, sheets and the like, and can be subjected to a final molding step.

The method for molding the thermosetting resin composition of the present invention includes injection molding, transfer molding,
It can be formed into a desired shape using a generally known molding method such as press molding, and can be cured by heating or irradiating a high energy ray with a radical generated by (E) a radical polymerization initiator. it can. As the conditions for the heat curing, an optimum temperature is selected according to the type of the radical polymerization initiator (E). As an example, when dicumyl peroxide is used as an organic peroxide, complete curing is performed by curing at 160 ° C for 5 minutes, demolding, and after-curing at 180 ° C for 1 hour. Can. It is also possible to adopt a process in which the curing is completed, for example, by keeping the inside of the mold at 185 ° C. for 5 minutes so that the after-cure can be omitted.

The thermosetting resin composition of the present invention includes:
To improve hardness, durability, weather resistance, water resistance, etc., besides the above-mentioned additives, ultraviolet absorbers, light stabilizers, antioxidants, defoamers, leveling agents, release agents, water repellency, etc. Can further improve the performance.

It is also practically advantageous that the thermosetting resin composition of the present invention has good processability and workability without containing any organic solvent. Of course, in order to further enhance the moldability of the thermosetting resin composition of the present invention, it is possible to further improve the fluidity by adding a solvent. In addition, the thermosetting resin composition of the present invention can be stably stored at room temperature for a long period of time until it is subjected to a processing step, and the thermosetting resin composition such as a conventional condensation reaction type epoxy resin or phenol resin can be used. It is one of the features not seen.

The thermosetting resin composition of the present invention is made of a material which can be easily obtained in large quantities and is extremely practical, and its cured product has high molding accuracy, excellent heat resistance and excellent heat resistance. Since it also has corrosion resistance, it is useful for various applications such as electronics, electric products, mechanical parts, vehicles, and the like.

[0021]

The component (A) of the thermosetting resin composition of the present invention comprises:
It is a vinyl ester resin which can be called a special unsaturated polyester resin, and is produced by reacting bisphenol A type glycidyl ether or novolak type glycidyl ether with acrylic acid or methacrylic acid.
The resin composition containing a vinyl ester resin has a low viscosity of the resin composition and is advantageous in molding when compared with that containing an unsaturated polyester resin, and the cured product of the vinyl ester resin has excellent heat resistance and corrosion resistance. Therefore, it can be said that the present invention is suitable as a base resin of a material targeted by the present invention. In particular, when a novolak-based vinyl ester resin is employed, a sharp, ie, short-time, heat generation of curing is realized, which leads to efficient expression of the function of the low-shrinkage agent. As described above, styrene is usually used as a solvent and monomer also in the vinyl ester resin. However, in the present invention, in order to avoid adverse effects associated with styrene, (C) an allyl ester monomer and / or (meth) acrylic acid are used. It is necessary to employ an ester monomer. Further, in the present invention, (D) a thermoplastic polyester resin satisfying specific conditions is blended. It should be noted that, with general-purpose unsaturated polyester resins, a technique for reducing shrinkage during curing by combining a thermoplastic resin has been found, but this technique has not always been successful except for a system using styrene as a solvent and monomer. In a vinyl ester resin, even in a system using styrene, it is difficult to apply a technique for reducing curing shrinkage by adding a thermoplastic resin. According to the present invention, by combining a combination of specific components and a thermoplastic polyester resin satisfying specific conditions,
For the first time, a reduction in cure shrinkage could be achieved. Furthermore, the specific component used in the thermosetting resin composition of the present invention has good copolymerizability, and this is also considered to contribute to small curing shrinkage during molding.

[0022]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which by no means limit the present invention. The resins used in the examples are as follows.

[Vinyl ester resin] A-1: Bisphenol-based vinyl ester resin (trade name: epoxy ester EH-1001, manufactured by Kyoeisha Chemical) A-2: Novolak-based vinyl ester resin (trade name: Lipoxy SP-4070, Showa Kobunshi) Made)

[Unsaturated polyester resin] B-1: Condensate having the composition shown in Table 1 below, number average molecular weight 3,800, melting point 120
° C.

[0025]

[Table 1] 1,4-butanediol 5.3 mol Ethylene glycol 4 mol 1,4-cyclohexanedimethanol 1 mol 2,6-naphthalenecarboxylic acid dimethacrylate 6 mol Fumaric acid 4 mol

B-2: Condensate having the composition shown in Table 2 below, number average molecular weight 4100, softening point 76 ° C.

[0027]

[Table 2] 1,4-cyclohexanedimethanol 6 mol Hydrogenated bisphenol A 4 mol 1,4-cyclohexanedicarboxylic acid 6 mol Fumaric acid 4 mol

[Thermoplastic polyester resin] 682 g (11.0 mol) of ethylene glycol, 679 g (3.5 mol) of dimethyl terephthalate, zinc acetate were placed in a 5-liter flask equipped with a thermometer, a stirrer, a fractionating condenser, and a gas inlet tube. 2.6 g was added and transesterification was performed at 200 ° C. Then 332 g (2.0 mol) of isophthalic acid sebacic acid
909 g (4.5 mol), hydroquinone 0.3 g, tetraisopropyl orthotitanate 1.3 g were added,
At the stage when the esterification reaction was carried out at 220 ° C. and the acid value reached 6.8, the reaction was carried out at 1.5 Torr for 3 hours under reduced pressure in the flask, and then the resin was poured into a metal vat and solidified by cooling. The obtained pale yellow resin had a number average molecular weight of 13,200 and a weight average molecular weight of 58,000 as measured by GPC. The Tg measured by DMA was -15 ° C. This resin is designated as D-1.

Example 1 The materials shown in Table 3 below were mixed and kneaded at 40 ° C. sequentially using a roll to obtain a sheet-shaped resin composition. This does not change its properties after storage at 30 ℃ for 3 months,
Storage stability was also sufficient.

[0030]

[Table 3] A-1 resin 50 parts by weight B-2 resin 15 parts by weight Trimethylolpropane trisoxyethylene methacrylate 10 parts by weight Diallyl terephthalate 15 parts by weight D-1 resin 10 parts by weight Silica powder 180 parts by weight Milled fiber 30 parts by weight 1.5 parts by weight of t-butyl peroxybenzoate

The curing shrinkage ratio of this resin composition is measured according to JIS K
It was 0.23% when measured according to 6911, and a favorable shrinkage reduction effect was observed. Next, press the sheet
Press and heat at 150 ° C for 5 minutes to cure and cure 300 x 300
A resin plate having a size of × 4 mm was molded. This plate was cut and measured for physical properties in accordance with JIS K6911. The bending strength was 8.6 kgf / mm ² and the elongation was 6%.
The strength retention after the heat treatment for 200 hours was as good as 87%. An immersion test was carried out in a 1% aqueous NaOH solution at 40 ° C. for 1 week, and no abnormality was found.

Example 2 Using a kneader, the materials shown in Table 4 below were kneaded and mixed at 40 ° C. sequentially to obtain a sheet-shaped resin composition. This does not change its properties after storage at 30 ℃ for 3 months,
Storage stability was also sufficient.

[0033]

Table 4 A-2 resin 50 parts by weight B-1 resin 20 parts by weight Benzyl methacrylate 10 parts by weight Diallyl terephthalate 15 parts by weight D-1 resin 5 parts by weight Calcium carbonate 300 parts by weight 1/8 inch glass fiber 20 parts by weight t -Butyl peroxybenzoate 1.5 parts by weight

The curing shrinkage ratio of this resin composition is determined according to JIS K
It was 0.08% when measured according to 6911, and an extremely favorable shrinkage reduction effect was observed. This sheet was pressed and heated at 150 ° C. for 5 minutes in a press to cure the sheet.
A resin plate similar to the above was molded. When this plate was cut and measured for physical properties, the bending strength was 14.5 kgf / mm ² and the elongation was 3
%, And the strength retention after heat treatment at 160 ° C. for 200 hours is 92%.
% Was good. An immersion test was carried out in a 1% aqueous NaOH solution at 40 ° C. for 1 week, and no abnormality was found.

[0035]

According to the present invention, there is provided a thermosetting resin composition having a small curing shrinkage during molding and having a cured product exhibiting excellent heat resistance and corrosion resistance.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 67/02 C08L 67/02 67/06 67/06 (72) Inventor Kentaro Takahashi Kaizawacho, Takasaki City, Gunma Prefecture 701-1A101 F-term (reference) 4J002 CD20W CF00Y CF03Y CF04Y CF21X CF22X DE048 DE238 DG058 DJ008 EE037 EH006 EH076 EH106 EH146 EK017 EK037 EK047 EK057 EK067 EU237 EW147 FD018 FD157 AB03A00 AB00A01BA00 BA11 BA19 BA22 BA24 BA26 BA28 CA06 CB04 CB10 CD01

Claims (7)

[Claims] 1. A method comprising: (A) a vinyl ester resin; (B) an unsaturated polyester having a melting point or softening point in the range of 60 to 150 ° C .; and (C) an allyl ester monomer and a (meth) acrylate monomer. A thermosetting resin composition comprising one or more kinds of monomers selected from the group consisting of (D) a thermoplastic polyester resin having a Tg of 0 ° C. or lower, and (E) a radical polymerization initiator. 2. The thermosetting resin composition according to claim 1, wherein the vinyl ester resin as the component (A) is a novolak vinyl ester resin. 3. The method according to claim 1, wherein the allyl ester monomer as the component (C) is diallyl phthalate.
3. The thermosetting resin composition according to item 1. 4. The thermoplastic polyester resin as the component (D), wherein any of adipic acid, azelaic acid, sebacic acid and dodecane diacid or a mixture thereof is used as a raw dibasic acid, and Number average molecular weight is 5,
2. The method according to claim 1, wherein the range is from 000 to 50,000.
3. The thermosetting resin composition according to item 1. 5. The ratio of each component to the sum of components (A), (B), (C) and (D),
Component (A) is 10 to 80% by weight, component (B) is 2 to 40% by weight, component (C) is 10 to 60% by weight, component (D) is 2 to 15% by weight, and (A) The thermosetting resin composition according to claim 1, wherein the sum of the component, the component (B), the component (C), and the component (D) is 100% by weight. 6. The thermosetting resin composition according to claim 1, wherein the radical polymerization initiator of the component (E) is an organic peroxide or a photopolymerization initiator. 7. A composite material obtained by compounding the thermosetting resin composition according to any one of claims 1 to 6 with an equal amount or more of an inorganic filler by weight, and molding and curing the same.