JPH04253755A - Production of epoxy resin composition and laminate - Google Patents

Abstract

PURPOSE:To produce an epoxy resin composition which increases less in viscosity at ordinary temperature and is improved in storage stability by mixing an epoxy resin with a specified polybasic acid anhydride, a polymerizable unsaturated resin and a polymerization initiator. CONSTITUTION:The title composition is obtained by mixing a normally liquid epoxy resin (A) desirably having an average epoxy equivalent of 100-400 with a polybasic acid anhydride (B) having an active oxygen content of 300ppm or below, desirably 20ppm or below, desirably an alicyclic polybasic acid anhydride of an active oxygen content of 20ppm or below, a polymerizable unsaturated resin (C) (e.g. epoxy vinyl ester resin) which is a resin having a radical- polymerizable C-C double bond and can be cured by the radical polymerization reaction of this double bond in an amount to give an (A+B)/(C) weight ratio of (95-30)/(5-70), 0.1-5 pts.wt., per 100 pts.wt. component B, polymerization initiator and optionally a latent cure accelerator, etc.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition having excellent storage stability with little increase in viscosity at room temperature, and a method for producing a laminate using the same.

0002

[Prior Art] A combination of a solvent-free liquid epoxy resin, a polybasic acid anhydride such as methyltetrahydrophthalic anhydride, an epoxy vinyl ester resin and/or an unsaturated polyester resin, a polymerization initiator, and, if necessary, a curing accelerator. B by impregnating the epoxy resin composition into a fibrous base material and heating it.
- A method is known in which a laminate is manufactured by staging and then heating and press molding (Japanese Patent Application Laid-Open No. 59-49240).

0003

[Problems to be Solved by the Invention] However, since the viscosity of the epoxy resin composition containing a polybasic acid anhydride such as methyltetrahydrophthalic anhydride increases gradually after preparation, it is difficult to use the resin composition. When impregnating a fibrous base material using a method, it must be carried out within several hours in a low-temperature controlled working environment, which is a serious drawback in terms of process control.

0004

[Means for Solving the Problems] In view of the above circumstances, the present inventor has developed an epoxy resin, a polybasic acid anhydride, and a polymerizable unsaturated group such as an epoxy vinyl ester resin and/or an unsaturated polyester resin. We focused on an epoxy resin composition consisting of a resin with
By using a resin composition of less than m, the increase in viscosity of the resin composition will be small at room temperature, and a long impregnation operation time will be possible. − Variations in staging are reduced,
The present inventors have discovered that a laminate with few voids and excellent water absorption and solder heat resistance can be obtained, leading to the completion of the present invention.

That is, the present invention provides epoxy resin (A)
In an epoxy resin composition containing a polybasic acid anhydride (B), a resin having a polymerizable unsaturated group (C), and a polymerization initiator (D), the polybasic acid anhydride (B) is active. An epoxy resin composition characterized by being a polybasic acid anhydride having an oxygen content of 30 ppm or less, and an epoxy resin (A)
An epoxy resin composition (I) containing a polybasic acid anhydride (B), a resin having a polymerizable unsaturated group (C), and a polymerization initiator (D) is added to a fibrous base material (II). A method for producing a laminate in which the polybasic acid anhydride (B) is a polybasic acid anhydride having an active oxygen content of 30 ppm or less, wherein the polybasic acid anhydride (B) is a polybasic acid anhydride having an active oxygen content of 30 ppm or less. This is what we provide.

Typical examples of the epoxy resin (A) used in the present invention include epichlorohydrin or β-
Epoxy resin obtained from methyl epichlorohydrin and bisphenol A, bisphenol F or bisphenol S; polyglycidyl ethers of phenol or alkylphenol novolak resin; ethylene glycol, propylene glycol, polyethylene glycol,
polypropylene glycol, neopentyl glycol,
Polyglycidyl ethers of polyhydric alcohols such as glycerin, trimethylolethane, trimethylolpropane or adducts of bisphenol A with ethylene oxide or propylene oxide; of adipic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid or dimer acids Polyglycidyl esters of polycarboxylic acids such as cyclohexene-based epoxy compounds (3,4-epoxy-6-methyl-cyclohexyl-3,4-epoxy) obtained by epoxidizing cyclohexene or its derivatives with peracetic acid etc. -6-methyl-cyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl-3,4-cyclohexanecarboxylate, 1-epoxyethyl-3,4-epoxycyclohexane, etc.); cyclopentadiene or dicyclopentadiene or derivatives thereof. Cyclopentadiene-based epoxy compounds obtained by epoxidation with peracetic acid etc. (cyclopentadiene oxide, dicyclopentadiene oxide, 2,3-epoxycyclopentyl ether, etc.); limonene dioxide; or glycidyl ether ester of hydroxybenzoic acid These can be used alone or in combination of two or more.

The epoxy resin (A) is preferably a liquid epoxy resin at room temperature, for example a liquid epoxy resin having an average epoxy equivalent of 100 to 400. In addition, polybasic acid anhydrides (
As B), any polybasic acid anhydride having an active oxygen content of 30 ppm or less can be used, but usually a polybasic acid anhydride having an active oxygen content of 20 ppm or less is used. Representative examples include phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, nadic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, and succinic anhydride. acid, itaconic anhydride, citraconic anhydride, dodecenyl succinic anhydride, chlorendic anhydride, etc. Among them, it has excellent electrical properties such as tracking resistance,
Alicyclic polybasic acid anhydrides are preferable in that the color tone of the cured product is light, such as hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, etc., all of which have a low active oxygen content. is 20pp
m or less. These may be used alone or in combination of two or more. An epoxy resin composition using a polybasic acid anhydride with an active oxygen content of 30 ppm or more has a large increase in viscosity near room temperature, making it impossible to perform long impregnation operations. The variation in B-staging due to preheating of the impregnated base material obtained by
This is not preferable because it results in a laminate with many voids and poor water absorption and solder heat resistance.

The reason for this is presumed to be that a large amount of active oxygen in the polybasic acid anhydride promotes polymerization of the polymerizable unsaturated groups in the epoxy resin composition (I). Incidentally, the amount of active oxygen in the polybasic acid anhydride was measured by the following method. That is, 10 g of the sample was accurately weighed into a 300 cc Erlenmeyer flask, dissolved in 30 cc of isopropyl alcohol, and then 1 cc of the supernatant of a saturated aqueous solution of potassium iodide was added.
and 1 cc of acetic acid were added, heated at 80° C. for 4 minutes, and titrated while hot with a sodium thiosulfate solution until the yellow color of iodine disappeared.

Furthermore, a resin (C) having a polymerizable unsaturated group
Examples include resins that have a radically polymerizable carbon-carbon double bond and are cured by a radical polymerization reaction of the double bond. Typical examples include epoxy vinyl ester resin, unsaturated polyester resin, and urethane acrylic resin. Ray
Examples include polyester resin, polyester acrylate resin, diallyl phthalate resin, spiran resin, and addition polymerization type polyimide resin. Among these, epoxy vinyl ester resins and unsaturated polyester resins are preferred, and epoxy vinyl ester resins are particularly preferred since they are excellent in heat resistance and adhesiveness to metal foil.

As the epoxy vinyl ester resin, for example, various epoxy resins such as those mentioned above as the epoxy resin (A), preferably bisphenol type or novolak type epoxy resins, or mixtures thereof, and the following non-containing resins are used. Examples include resins obtained by reacting with saturated monobasic acids, among which polybasic acid anhydrides (
A resin obtained by esterifying B) with the epoxy resin (A) or the epoxy vinyl ester resin in the presence of an esterification catalyst that does not promote the reaction is preferable, and usually esterification of the epoxy group in the epoxy resin (A) is preferred. rate is 60
%, preferably 90% or more.

Typical unsaturated monobasic acids include acrylic acid, methacrylic acid, cinnamic acid, crotonic acid, monomethyl maleate, monopropyl maleate, monobutyl maleate, sorbic acid, and mono(2- ethylhexyl) malate, etc., and these may be used alone or in combination of two or more. In addition, as the esterification catalyst that does not promote the reaction between the polybasic acid anhydride (B) and the epoxy resin (A) or epoxy vinyl ester resin used here, phosphorus compounds such as phosphine derivatives and quaternary phosphonium salts are preferable. Among them, phosphine derivatives such as triphenylphosphine, tri-n-butylphosphine, etc. are particularly preferred. These esterification catalysts may be added in catalytic amounts, for example, 100 to 10,000 ppm to the epoxy resin and unsaturated monobasic acid as raw materials.
It is sufficient to add about m.

[0012] To obtain the epoxy vinyl ester resin,
It is recommended to use a polymerization inhibitor for the purpose of preventing gelation during the reaction and adjusting the storage stability or curability of the product.

Representative examples of such polymerization inhibitors include hydroquinone, pt-butylcatechol,
Hydroquinones such as mono-t-butylhydroquinone; hydroquinone monomethyl ether, di-t-p-
Examples include phenols such as cresol; quinones such as p-benzoquinone, naphthoquinone, and p-torquinone; and copper salts such as copper naphthenate.

These epoxy vinyl ester resins may be used by being dissolved in a solvent such as ketones or esters, or may be used by being dissolved together with other raw materials such as epoxy resin, but polymerizable vinyl monomers may be used. It is preferable to use only Examples of the polymerizable vinyl monomer in this case include styrene, vinyltoluene, t-butylstyrene,
Styrene and its derivatives such as chlorstyrene or divinylbenzene; methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, Low boiling ester monomers of (meth)acrylic acid such as 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, 2-hydroxyethyl (meth)acrylate or 2-hydroxypropyl (meth)acrylate; or trimethylolpropanetri (meth)acrylate, diethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate or 1,6-hexanediol di(meth)acrylate
Examples include (meth)acrylates of polyhydric alcohols such as acrylates, and among them, low-boiling ester monomers of styrene, vinyltoluene, and (meth)acrylic acid are preferred because of their low viscosity.

Examples of the polymerization initiator (D) used in the present invention include cyclohexanone peroxide, 3,3,5
-trimethylcyclohexanone peroxide, methylonexanone peroxide, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane,
Cumene hydroperoxide, dicumyl peroxide, lauroyl peroxide, 3,3,5-trimethylhexanoyl peroxide, benzoyl peroxide, di-myristyl peroxydicarbonate, t-
Butyl peroxy (2-ethylhexanoate), t-
Examples include organic peroxides such as butylperoxy-3,3,5-trimethylhexanoate, t-butylperoxybenzoate, and cumylperoxyoctoate.

[0016] A curing accelerator may be added to the epoxy resin composition of the present invention if necessary, but it is particularly desirable to use a latent curing accelerator in view of not reducing storage stability.

[0017] Examples of the latent curing accelerator include:
(1) A frozen latent curing accelerator made by mixing an epoxy resin and an amine compound and immediately freezing the mixture to stop the reaction.
(2) A microcapsule type latent curing accelerator in which an amine compound is microencapsulated, (3) a monocular sieve type latent curing accelerator in which a compound is adsorbed on a monocular sieve, (4) an amine compound and an epoxy group Examples include latent curing accelerators made by surface-treating adducts with compounds having isocyanate groups, and among others, they are easy to handle, have high workability, have an appropriate curing accelerating effect when heated, and have good physical properties. (4) above in that there is no decrease in
Particularly preferred are latent curing accelerators.

Examples of the amine compounds used to obtain the latent curing accelerator (4) include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenediamine,
Aliphatic amines such as diethylaminopropylamine, menzendiamine, isophorone diamine, bis(4-amino-3-methylcyclohexyl)methane, alicyclic amines such as N-aminoethylpiperazine, metaxylene diamine, tetrachloro-p - Aliphatic amines containing aromatic rings such as xylene diamine, aromatic amines such as metaphenylene diamine, diaminodiphenylmethane, diaminodiphenylsulfone, bisaminomethyldiphenylmethane, 2
-Methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2
Examples include imidazole compounds such as -methylimidazole and 1-cyanoethyl-2-ethyl-4-methylimidazole.

Further, as the compound having an epoxy group, any compound having one or more epoxy groups can be used, such as monoepoxy compounds such as aliphatic glycidyl ether, aromatic glycidyl ether, glycidyl alkylate, and the above-mentioned epoxy resins. (A), among others, solvent-free liquid or solid epoxy resins are preferred.

[0020] The adduct of an amine compound and an epoxy compound can be obtained, for example, by a conventionally known general method. The reaction ratio between the amine compound and the epoxy compound is such that the number of epoxy groups is 1 for each active hydrogen of the amine compound.
．． The ratio is 0 to 1.5, preferably 1.2 to 1.4. Although the addition reaction may be carried out without a solvent, a method is usually used in which the amine compound is dissolved in a suitable solvent and the epoxy compound is added dropwise or in portions. The solvent is
Aromatic solvents and ketone solvents are preferred, such as toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, and the like. When the addition reaction is carried out without a solvent, the obtained adduct is ground to the desired particle size and used. When the addition reaction is carried out in a solvent, a method of spray drying after the completion of the reaction, a method of removing the solvent and pulverizing, etc. are employed. The particle size is usually 30 μm or less, preferably 0.1 to 10 μm, particularly preferably 1 to 6 μm. If the diameter is 30 μm or more, problems tend to occur in dispersibility.

Further, as compounds having an isocyanate group, for example, aromatic or aliphatic monoisocyanates,
Aromatic or aliphatic polyisocyanates, polyisocyanates that are adducts of polyols and polyisocyanates,
Examples include biuret type polyisocyanate, cyclization polymerization type polyisocyanate, etc. obtained by the reaction of polyisocyanate and water, and specifically phenyl isocyanate,
Monoisocyanate compounds such as tolyl isocyanate,
Tetramethylene diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, isopropylidenecyclohexyl isocyanate, lysine isocyanate, adduct of tolylene diisocyanate and trimethylolpropane, adduct of tolylene diisocyanate and pentaerythritol, tolylene diisocyanate Examples include polyisocyanate compounds such as an adduct of isocyanate and polyethylene glycol, an adduct of tolylene diisocyanate and polypropylene glycol, and a prepolymer of hexamethylene diisocyanate and polyethylene adipate. Among these, aromatic or aliphatic polyisocyanates and polyisocyanates which are adducts of polyols and polyisocyanates are preferred.

The method for surface-treating the adduct of an amine compound and an epoxy compound with a compound having an isocyanate group is not particularly limited, but for example, a solvent that does not dissolve the powdered adduct, such as toluene, xylene, acetone, Examples include a method of first dissolving a predetermined amount of a compound having an isocyanate group in methyl ethyl ketone or the like, then dispersing the powdered adduct therein, subjecting it to surface treatment, scattering the solvent, and drying. The amount of the compound having an isocyanate group to be used is usually 0.5 to 20 parts by weight, preferably 1.0 to 10 parts by weight, based on 100 parts by weight of the above-mentioned adduct.

The epoxy resin composition (I) of the present invention is:
Each of the components (A) to (D) above is used as an essential component, and if necessary, a polymerizable vinyl monomer, other solvents,
Curing accelerators such as latent curing accelerators, internal mold release agents, pigments,
A composition containing additives such as fillers, which can be impregnated into a fibrous base material. In addition, the solid components are
At the time of impregnation, it is not necessarily necessary to dissolve or melt the material in the liquid component, but it may be used in the form of a powder dispersed in the liquid component.

Weight ratio of the total of the components (A) and (B) to the component (C) contained in the epoxy resin composition (I) [(A)+(B)]/(C) is usually 95
/5 to 30/70, but the curing shrinkage is small, and metal,
In particular, 90/10 to 50/50 is preferable in terms of excellent adhesion and moldability to copper foil and fibrous base materials, especially glass fibers.

Further, the amount of the polymerization initiator (D) added is usually 0 to 100 parts by weight of the resin having a polymerizable unsaturated group.
．． The amount is 1 to 5 parts by weight, preferably 0.5 to 3 parts by weight. Furthermore, when using a latent curing accelerator, the amount added is usually 0.1 parts by weight per 100 parts by weight of the polybasic acid anhydride (B).
-10 parts by weight, preferably 0.5-5 parts by weight.

[0026] The filler to be added to the epoxy resin composition (I) as necessary is selected depending on the required performance, working conditions, etc., but examples include aluminum hydroxide, aluminum silicate, colloidal silica, and carbonate. These include calcium, calcium sulfate, mica, talc, titanium dioxide, quartz powder, zirconium silicate, glass powder, asbestos powder, diatomaceous earth, and antimony trioxide.

[0027] The method and order of blending each component to obtain the epoxy resin composition (I) are not particularly limited, but after mixing the liquid components, solid components may be added in powder form. , decomposition or dissolution methods are preferred.

On the other hand, the fibrous base material (II) used in the present invention
Typical examples include glass fiber, carbon fiber, and aromatic polyamide fiber, with glass fiber being particularly preferred. Among these, glass fibers include E-glass, C-glass, A-glass, and S-glass from the viewpoint of their raw materials, but any of these types can be used in the present invention.

These fibrous base materials can be classified into rovings, chopped strand mats, continuous mats, cloths, nonwoven fabrics, roving cloths, surfacing mats, and chopped strands depending on their shape.
The above-mentioned types and shapes are appropriately selected depending on the intended use and performance of the molded product, and two or more types or shapes may be used in combination if necessary. Among them, cloth and nonwoven fabric are preferred.

A method for obtaining a laminate using the epoxy resin composition (I) of the present invention includes, for example: A method in which the upper and lower surfaces are covered with metal foil and/or a cover film, preheated if necessary, and then heated and cured; ■ Impregnation of the fibrous base material (II) with the epoxy resin composition (I); Examples include a method in which the B-staged material is B-staged while removing the polymerizable vinyl monomer in a drying oven, and then a predetermined number of sheets of this B-staged material are stacked and cured by heating.

[0031] Heat curing by the above methods (1) and (2) is as follows:
The molding may be carried out under no pressure in a continuous heating furnace, or may be continuously heated and pressed using a continuous double belt press. Alternatively, after preheating the laminate in (1) or B-staging the product in (2), the laminate and the B-staged product may be cut and heated and press-molded in a batchwise manner. Preheating (1) and B-staging (2) are usually carried out at a temperature range of 70 to 150°C, and heat curing is both carried out at 130 to 190°C. In the case of hot pressure molding, it is usually 5 to 40 kg/c.
It is carried out under a pressure of m2.

[0032]

EXAMPLES Next, the present invention will be explained in more detail by giving production examples, working examples, and comparative examples. In addition, all parts and percentages in the examples are based on weight unless otherwise specified.

Production Example 1 (Production of epoxy vinyl ester resin) 600 parts of an epoxy resin with an epoxy equivalent of 400 obtained by the reaction of tetrabromobisphenol A and epichlorohydrin, 124 parts of methacrylic acid, 0.4 part of hydroquinone, and triphenyl. 5.0 parts of phosphine at 110℃
After reacting for 4 hours, 270 parts of styrene monomer was added and uniformly dissolved to obtain an epoxy vinyl ester resin solution (C-1).

Production Example 2 (Production of curing accelerator) An epoxy resin having an epoxy equivalent of 190 obtained by the reaction of bisphenol A and epichlorohydrin was reacted with 2-methylimidazole at 120°C for 1.5 hours in xylene. Obtain the adduct (reaction molar ratio 1:2), separate the solvent,
It was further dried. Then, it was finely pulverized to obtain a powder with an average particle size of 4.0 μm.

100 parts of this powder was dispersed in 250 parts of hexane, 3 parts of xylylene diisocyanate was added while stirring at 60°C, stirring was continued for 1 hour, and then filtered.
A surface-treated curing accelerator (E-1) was obtained by drying under reduced pressure.

Example 1 Epoxy resin 18.2 with an epoxy equivalent of 190 obtained by the reaction of bisphenol A and epichlorohydrin
parts, 22.8 parts of an epoxy resin with an epoxy equivalent weight of 370 obtained by the reaction of tetrabromobisphenol A and epichlorohydrin, methylhexahydrophthalic anhydride (
Active oxygen content: 13 ppm) 25.2 parts, epoxy vinyl ester resin solution (C-1) 28.0 parts, benzoyl peroxide 0.56 parts, styrene monomer 4.88 parts
1 part and 1.0 part of curing accelerator (E-1) were mixed to prepare a liquid epoxy resin composition (I-1).

[0037] Then, immediately this epoxy resin composition (
I-1) was added to a long glass cloth with a thickness of 0.18 mm and a width of 1050 mm, and the content of the epoxy resin composition was 43%.
8 sheets of this were layered, and 35 μm thick copper foil was layered on top and bottom of the foil, heated in a heating furnace at 110°C for 4 minutes and conveyed, and then heated to 170°C on a double belt. After heating and pressure molding for 10 minutes with a press machine at a pressure of 20 kg/cm2,
Cut to 0 mm, then post-cure at 170°C for 5 minutes,
Twenty laminate plates (III-1) having a thickness of 1.6 mm were obtained.

Furthermore, 20 laminates ( IV-1) was obtained.

Each of the 20 laminates obtained (III
-1) and (IV-1), the amount of resin flowing out during molding, water absorption, and solder heat resistance were measured as follows, and good results with little variation were obtained. Furthermore, there was little variation between the laminates (III-1) and (IV-1), and it was confirmed that the epoxy resin composition (I-1) has excellent storage stability. The results are shown in Table 1.

・Resin outflow amount (%): Resin outflow amount (%) =
It was calculated as (W0 - W1)/W0 x 100 and shown as an average value. However, W0 is the weight of 8 resin-impregnated substrates with an epoxy resin composition content of 43% and dimensions of 1000 mm x 1000 mm, and W1 is the size of 10 pieces obtained by heating and pressure molding.
This is the weight obtained by subtracting the weight of the copper foil from the laminate of 00 mm x 1000 mm.

Water absorption rate (%): After removing the copper foil on one side of the laminate cut into 25 mm x 25 mm by etching,
A pressure cooker test was conducted for 4 hours at 120℃ and 2 atmospheres, and the water absorption rate (%) = (W'-W)/W x 10
It was calculated using 0 and shown as an average value. Here, W is the weight of the laminate before the test, and W' is the weight of the laminate after the test.

Soldering heat resistance: After thoroughly wiping off moisture on the surface of the laminate after the pressure cooker test,
It was measured according to JIS C-6481 and evaluated based on the following criteria.

◯: There were no samples with poor solder heat resistance. △: Less than 1/4 of the samples had poor solder heat resistance. ×: More than 1/4 of the samples had poor solder heat resistance.

Example 2 Methylhexahydrophthalic anhydride (active oxygen content: 1
A liquid epoxy resin composition (I-2) was obtained in the same manner as in Example 1, except that 25.2 parts of tetrahydrophthalic anhydride (active oxygen content: 6 ppm) was used instead of 25.2 parts of tetrahydrophthalic anhydride (active oxygen content: 6 ppm). Ta.

Next, this epoxy resin composition (I-2
) was used in the same manner as in Example 1, except that a laminate (II
I-2) and the epoxy resin composition 30 hours after preparation (I-2)
2) of 20 laminates (IV-2) each using
After each sheet was obtained, similar measurements were performed, and good results with little variation were obtained. Also, a laminate (III-
There was little variation between 2) and (IV-2), and it was confirmed that the epoxy resin composition (I-2) had excellent storage stability. The results are shown in Table 1.

Comparative Example 1 Methylhexahydrophthalic anhydride (active oxygen content: 1
3ppm) instead of 25.2 parts of 3-methyltetrahydrophthalic anhydride (active oxygen content: 120ppm) 25
．． A liquid epoxy resin composition (I'-1) was obtained in the same manner as in Example 1 except that 2 parts were used, and a laminate (III ′
-1) and the epoxy resin composition after 30 hours of preparation (I'-
1) 20 laminates (IV'-1) each
I got one each. When similar measurements were then performed, results with large variations were obtained. Also, the laminate (III'-1
) and (IV'-1), there was a clear difference in the results,
It was confirmed that the above epoxy resin composition (I'-1) had poor storage stability. The results are shown in Table 1.

Comparative Example 2 Methylhexahydrophthalic anhydride (active oxygen content: 1
4-methyltetrahydrophthalic anhydride (active oxygen content: 109 ppm) 25
．． A liquid epoxy resin composition (I'-2) was obtained in the same manner as in Example 1 except that 2 parts were used, and a laminate (III ′
-2) and the epoxy resin composition (I'-
2) of 20 laminates (IV'-2) each using
I got one each. When similar measurements were then performed, results with large variations were obtained. Also, the laminate (III'-2
) and (IV'-2), there was a clear difference in the results,
It was confirmed that the above epoxy resin composition (I'-2) had poor storage stability. The results are shown in Table 1.

[0048]

[Table 1]

[0049]

Effects of the Invention The use of the epoxy resin composition of the present invention has the advantage that impregnation work can be carried out over a long period of time, and a laminate with excellent water absorption and solder heat resistance and less variation can be obtained.

Claims (8)

[Claims] Claim 1. An epoxy resin composition comprising an epoxy resin (A), a polybasic acid anhydride (B), a resin having a polymerizable unsaturated group (C), and a polymerization initiator (D), An epoxy resin composition characterized in that the polybasic acid anhydride (B) is a polybasic acid anhydride having an active oxygen content of 30 ppm or less. 2. The resin composition according to claim 1, wherein the polybasic acid anhydride (B) has an active oxygen content of 20 ppm or less. 3. The resin composition according to claim 1, wherein the polybasic acid anhydride (B) is an alicyclic polybasic acid anhydride having an active oxygen content of 20 ppm or less. 4. Claim 1, wherein the polybasic acid anhydride (B) is one or more polybasic acid anhydrides selected from the group consisting of hexahydrophthalic anhydride, tetrahydrophthalic anhydride, and methylhexahydrophthalic anhydride. The resin composition described. 5. An epoxy resin composition (I) containing an epoxy resin (A), a polybasic acid anhydride (B), a resin having a polymerizable unsaturated group (C), and a polymerization initiator (D). ) is impregnated into the fibrous base material (II) and then heated and cured, in which the polybasic acid anhydride (B) is a polybasic acid anhydride with an active oxygen content of 30 ppm or less. A method for manufacturing a laminate featuring: 6. The production method according to claim 5, wherein the polybasic acid anhydride (B) has an active oxygen content of 20 ppm or less. 7. The production method according to claim 5, wherein the polybasic acid anhydride (B) is an alicyclic polybasic acid anhydride having an active oxygen content of 20 ppm or less. 8. Claim 5, wherein the polybasic acid anhydride (B) is one or more polybasic acid anhydrides selected from the group consisting of hexahydrophthalic anhydride, tetrahydrophthalic anhydride, and methylhexahydrophthalic anhydride. Manufacturing method described.