TW202136354A - Epoxy resin composition and cured resin - Google Patents

Abstract

An object of the present invention is to provide an epoxy resin composition which is capable of forming a cured resin product having excellent impact resistance. The epoxy resin composition of the present invention contains an epoxy resin (A) having a solubility parameter (SP value) of 11 to 15 and a (meth) acrylic polymer (B) having an SP value of 9.5 to 11, wherein the (meth)acrylic polymer (B) is a reaction product of carboxy group-containing (meth) acrylic polymer (B1) and epoxy compound (B2), and the absolute value of the difference between the SP value of the (meth) acrylic polymer (B) and the SP value of the epoxy resin (A) is 0.1 to 3.3.

Description

Epoxy resin composition and resin cured product

The present invention relates to epoxy resin compositions and resin cured products.

Epoxy resins have been used in a wide range of fields such as adhesives and sealants due to their excellent physical properties (for example, refer to Patent Documents 1 to 2). The epoxy resin is usually used by hardening it to make a resin cured product.

[Prior Technical Literature]

[Patent Literature]

[Patent Document 1] JP 2002-080696 A

[Patent Document 2] International Publication No. 2017/195902

Hardened resins obtainable from epoxy resins have poor impact resistance. For example, in Patent Document 2, although an acrylic polymer has been added to the epoxy resin, according to the investigation of the present inventors, it has been found that the impact resistance of the resin cured product obtained in this type is not sufficient.

One aspect of the subject of the present invention is to provide an epoxy resin composition capable of forming a resin cured product with excellent impact resistance, and a resin cured product composed of the epoxy resin composition in view of the above-mentioned circumstances.

The present invention relates to, for example, the following [1] to [8].

[1] An epoxy resin composition containing an epoxy resin (A) having a solubility parameter (SP value) of 11 to 15 and a (meth)acrylic polymer (B) having an SP value of 9.5 to 11, wherein , The aforementioned (meth)acrylic polymer (B) is a reaction product of "carboxyl group-containing (meth)acrylic polymer (B1) and epoxy compound (B2)", and the aforementioned (meth)acrylic polymer ( The absolute value of the difference between the SP value of B) and the SP value of the aforementioned epoxy resin (A) is 0.1 to 3.3.

[2] The epoxy resin composition according to the above [1], which contains 0.1 to 70 parts by mass of the (meth)acrylic polymer (B) with respect to 100 parts by mass of the epoxy resin (A).

[3] The epoxy resin composition according to [1] or [2], wherein the SP value of the carboxyl group-containing (meth)acrylic polymer (B1) and the SP value of the epoxy compound (B2) The absolute value of the difference is 1.3 to 4.5.

[4] The epoxy resin composition according to any one of [1] to [3], wherein the weight average molecular weight of the (meth)acrylic polymer (B) is 3,000 to 100,000.

[5] The epoxy resin composition according to any one of [1] to [4], which further contains a hardener (C).

[6] A cured resin made of the epoxy resin composition described in any one of [1] to [5].

[7] A cured resin obtained by curing an epoxy resin composition containing an epoxy resin and a (meth)acrylic polymer, and has a sea-island phase separation structure, wherein the average dispersion diameter of the island phase is 0.01 to 0.84μm.

[8] The resin cured product according to the aforementioned [7], wherein the tensile elastic modulus (X) of the resin cured product and the tensile elastic modulus of the resin cured product without the (meth)acrylic polymer (Y) system satisfies the following formula (2).

0.6≦X/Y≦1.1‧‧‧(2)

According to the present invention, it is possible to provide a resin cured product that uses a specific (meth)acrylic polymer blended in an epoxy resin as a modifier, and therefore has excellent impact resistance.

Hereinafter, the present invention will be specifically explained. In this specification, (meth)acrylic acid is used as a collective name for acrylic acid and methacrylic acid, which can be either acrylic or methacrylic acid; (meth)acrylic acid is used as a collective name for acrylate and methacrylate , Can be acrylate or methacrylate.

[Epoxy resin composition]

One embodiment of the epoxy resin composition of the present invention (hereinafter also referred to as the "epoxy resin composition of the present embodiment") contains rings with solubility parameters (SP values) of 11 to 15 as described below, respectively. Oxygen resin (A) and (meth)acrylic polymer (B) having an SP value of 9.5 to 11. Here, (methyl) The acrylic polymer (B) is a reaction product of a carboxyl group-containing (meth)acrylic polymer (B1) and an epoxy compound (B2).

(Solubility parameter (SP value))

The solubility parameter (SP value) is used as, for example, what indicates the degree of dissolution between different types of polymers. Since the difference between the SP value of the (meth)acrylic polymer (B) and the SP value of the epoxy resin (A) is within an appropriate range, the phases of the islands in the cured resin having a sea-island phase separation structure described later can be reduced. The tendency of the average dispersion diameter to be controlled to an appropriate value.

In addition, the SP value of epoxy resin (A), (meth)acrylic polymer (B), carboxyl group-containing (meth)acrylic polymer (B1), and compound (B2) in this specification can be obtained from Robert F. Fedors., "POLYMER ENGINEERING AND SCIENCE", 1974, Vol. 14 (Volume 14), No. 2 (No. 2), the sum of the molar heat of evaporation (△ei) of atomic groups described on pages 151 to 153 The total (V) of (△H) and molar volume (△vi) is calculated.

<Epoxy resin (A)>

The epoxy resin composition of this embodiment contains epoxy resin (A). However, the epoxy resin (A) does not include a polymer having an epoxy group which is the reaction product of the aforementioned carboxyl group-containing (meth)acrylic polymer (B1) and the epoxy compound (B2).

Examples of the epoxy resin (A) include epoxy compounds in which the number of epoxy groups in one molecule is two or more.

The epoxy resin (A) can be enumerated: for example

Bisphenol A type epoxy resin, Bisphenol E type epoxy resin, Bisphenol F type epoxy resin, Bisphenol S type epoxy resin, Bisphenol O type epoxy resin, Bisphenol AD type epoxy resin and other bisphenols Type epoxy resin, hydrogenated bisphenol type epoxy resin, alkyl substituted bisphenol type epoxy resin, alkylene oxide modified bisphenol type epoxy Resin, biphenyl type epoxy resin, resorcinol type epoxy resin, sulfide type epoxy resin, diphenyl ether type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, Phenolic novolac epoxy resin, o-cresol novolac epoxy resin, dicyclopentadiene novolac epoxy resin, biphenol novolac epoxy resin, naphthol novolac epoxy resin, glycidyl amine epoxy resin ；

Bisphenol A, Bisphenol E, Bisphenol F, Bisphenol S, Bisphenol O, Bisphenol AD and other bisphenols or diglycidyl ether of 4,4-dihydroxybiphenyl [here, the aforementioned bisphenol and the aforementioned combination Benzene can be hydrogenated (e.g. hydrogenated bisphenol), can have alkyl substituents (e.g. alkyl substituted bisphenol), can be modified with ethylene oxide, modified with propylene oxide, etc. and modified with alkylene oxide (For example: modified bisphenol by alkylene oxide)], ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether , 1,8-octanediol diglycidyl ether, 1,10-decanediol diglycidyl ether, 2,2-dimethyl-1,3-propanediol diglycidyl ether and other alkanediol diglycidyl ethers , Glycerol diglycidyl ether and other alkane triol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, tetraethylene glycol diglycidyl ether, hexaethylene glycol diglycidyl ether Polyalkylene glycol diglycidyl ether, 1,4-cyclohexane dimethanol diglycidyl ether and other diglycidyl ether compounds containing alicyclic dimethanol diglycidyl ether;

Glycerol triglycidyl ether, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N,N'-tetraglycidyl-m-xylene diamine, N,N,N,N'-tetraglycidylaminophenylmethane, triglycidyl isocyanurate, m-N,N-diglycidylaminophenyl glycidyl ether, N, N-diglycidyl toluidine, N,N-diglycidyl aniline, 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate, ε-caprolactone Ester upgrades 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate.

The epoxy resin (A) may be used individually by 1 type, and may use 2 or more types.

The SP value of the epoxy resin (A) is from 11 to 15, preferably from 11 to 13.5. When the SP value is within the above range, it is preferable from the viewpoint that the epoxy resin (A) and the (meth)acrylic polymer (B) constitute a sea-island phase separation structure of an island phase having an average dispersion diameter of a suitable size.

In the epoxy resin composition of this embodiment, the absolute value of the difference between the SP value of the (meth)acrylic polymer (B) and the SP value of the epoxy resin (A) is 0.1 to 3.3, with 1.5 to 3.3 being good. When the absolute value of the difference in SP value is within the aforementioned range, the sea-island phase separation structure is likely to be formed after the resin composition is cured. In addition, as the average dispersion diameter of the island phase is suitable, the impact resistance of the cured resin can be further improved. Sexual orientation.

From the viewpoint of forming a sea-island phase separation structure with an average dispersion diameter of a suitable size, the absolute value of the difference between the SP value of the epoxy resin (A) and the SP value of the epoxy compound (B2) is preferably 0 to 2.7, with 0 To 2.5 is better. In one form, the value obtained by subtracting the SP value of the epoxy compound (B2) from the SP value of the epoxy resin (A) is preferably -2.7 to 1.2, more preferably -2.5 to 1.1.

The epoxy equivalent of the epoxy resin (A) is not particularly limited, but is preferably 100 to 3,000 g/eq., more preferably 100 to 1,000 g/eq.

<(Meth) acrylic polymer (B)>

(Meth)acrylic polymer (B) is a reaction product of carboxyl-containing (meth)acrylic polymer (B1) and epoxy compound (B2), and carboxyl-containing (meth)acrylic polymer (B1) An additional reactant with epoxy compound (B2) is preferred. That is, the (meth)acrylic polymer (B) has the following formula ( 1) Compounds of the structure shown are preferred.

By using the (meth)acrylic polymer (B) as a modifier for the epoxy resin (A), compared with the case where the modifier is not used, a resin cured product obtained from the epoxy resin of this embodiment The system shows high shock resistance. In addition, the above-mentioned cured resin can improve impact resistance without significantly changing the elastic modulus inherent in epoxy resin. In addition, the epoxy resin composition of this embodiment has high adhesion to metal adherends.

Although the reason for exhibiting such an effect is not clear, it is considered that proper compatibility between the epoxy resin and the modifier is important for forming a sea-island structure including an island phase with an appropriate size of average dispersion diameter. It can be assumed that because the (meth)acrylic polymer (B) of the above-mentioned reaction product is used as a modifier for the epoxy resin (A), the SP value and the SP value difference between the two are set to an appropriate range. They are moderately compatible and form a sea-island structure including island phases with an average dispersion diameter of a suitable size, thereby improving the impact resistance of the resin cured product obtained from the epoxy resin composition.

≪Carboxyl-containing (meth)acrylic polymer (B1)≫

The carboxyl group-containing (meth)acrylic polymer (B1) (hereinafter, also referred to as "polymer (B1)") has a structural unit derived from a monomer having a carboxyl group.

In addition, the monomer having a carboxyl group includes a compound formed by ring opening by hydrolyzing a monomer having an acid anhydride group.

Examples of monomers having carboxyl groups include carboxyl-containing monomers other than carboxyl-containing (meth)acrylates such as (meth)acrylic acid, itaconic acid, crotonic acid, maleic acid, and fumaric acid. Body; β-carboxyethyl (meth)acrylate, 5-carboxypentyl (meth)acrylate, amber Acid mono(meth)acryloyloxyethyl, ω-carboxy polycaprolactone mono(meth)acrylate, p-carboxybenzyl (meth)acrylate, and other carboxyl-containing (meth)acrylates.

Monomers containing acid anhydride groups include: for example, maleic anhydride, dodecenyl succinic anhydride, chlorobridged anhydride, sebacic anhydride, phthalic anhydride, pyromellitic anhydride, trimellitic anhydride, cyclopentane‧tetracarboxylic acid Acid dihydrate, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetramethylene maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, Endomethylene tetrahydrophthalic anhydride, methyl endomethylene tetrahydrophthalic anhydride, 5-(2,5-dioxotetrahydroxyfuranyl)-3-methyl-3-ring Hexene-1,2-dicarboxylic acid anhydride, nadic anhydride (nadic anhydride, bridge methylene tetrahydrophthalic anhydride). Among these, (meth)acrylic acid is preferred.

Among the polymerizable unsaturated group-containing monomers used to obtain the polymer (B1), the ratio of the monomer having a carboxyl group is preferably 0.8 to 15% by mass, more preferably 1 to 10% by mass.

The polymer (B1) is preferably a polymer having repeating units derived from (meth)acrylate. In one form, the polymer (B1) is preferably a polymer containing 40% by mass or more of (meth)acrylate and a polymerizable unsaturated group-containing monomer, more preferably 50% by mass or more, and still more preferably It contains 60% by mass or more.

(Meth) acrylates can include: for example

Methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate Ester, tert-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (meth)acrylate Base) n-octyl acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, iso-octyl (meth)acrylate Decyl ester, undecyl (meth)acrylate, lauryl (meth)acrylate, oleyl (meth)acrylate, n-stearyl (meth)acrylate, isostearyl (meth)acrylate Alkyl (meth)acrylates, especially alkyl (meth)acrylates having an alkyl group with 1 to 20 carbon atoms;

Cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, phenoxyethyl ( (Meth)acrylates containing alicyclic hydrocarbon groups or aromatic hydrocarbon groups, such as meth)acrylates;

Methoxymethyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 3-methoxypropyl (methyl) ) Acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, 4-ethoxybutyl (meth)acrylate and other alkoxyalkyls Base (meth)acrylate;

Methoxydiethylene glycol mono(meth)acrylate, methoxydipropylene glycol mono(meth)acrylate, ethoxytriethylene glycol mono(meth)acrylate, ethoxydiethylene glycol Alkoxy polyalkylene glycol mono(meth)acrylates such as mono(meth)acrylate and methoxytriethylene glycol mono(meth)acrylate;

N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate and other N,N-dialkylaminoalkyl (methyl) )Acrylate;

2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyl Hydroxyalkyl (meth)acrylates such as octyl (meth)acrylate;

2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyl Octyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxymethylcyclohexyl)methacrylate, etc. containing hydroxyl groups (Meth)acrylate.

From the viewpoint of making the (meth)acrylic polymer an appropriate SP value, among the polymerizable unsaturated group-containing monomers used to obtain the polymer (B1), alkyl (meth)acrylate and alicyclic The total ratio of the (meth)acrylate and alkoxyalkyl (meth)acrylate of the formula hydrocarbon group or aromatic hydrocarbon group is preferably 30 to 99% by mass, more preferably 70 to 99% by mass.

The polymer (B1) may have monomers derived from monomers having the aforementioned carboxyl group and (meth)acrylates other than monomers (selected from monomers containing hydroxyl groups, monomers containing amide groups, monomers containing cyano groups, A structural unit of at least one of a nitrogen-based heterocyclic ring-containing monomer, a styrene-based monomer, and a vinyl ether-based monomer).

Examples of the monomer containing a hydroxyl group include vinyl alcohol, allyl alcohol, 2-hydroxyethyl vinyl ether, and 4-hydroxybutyl vinyl ether.

Examples of monomers containing amide groups include: (meth)acrylamide; N-methyl(meth)acrylamide, N-propyl(meth)acrylamide, N-hexyl(methyl) N-alkyl(meth)acrylamide such as acrylamide; N,N-dimethyl(meth)acrylamide, N,N-dipropyl(meth)acrylamide, etc. N,N- Dialkyl (meth)acrylamide.

Examples of the cyano group-containing monomer include (meth)acrylonitrile.

Examples of the monomer containing a nitrogen-based heterocyclic ring include N-vinylpyrrolidone, N-vinylcaprolactone, and (meth)acryloylmorpholine.

Examples of styrene monomers include: styrene, α-methylstyrene; 4-methylstyrene, 3,5-diethylstyrene, trimethylstyrene, propylstyrene, and butylbenzene. Alkyl styrenes such as ethylene, hexyl styrene, heptyl styrene, octyl styrene, 3,5-dimethyl styrene; 4-fluorostyrene, 4-chlorostyrene, 4-bromostyrene, 3 , 5-Dibromostyrene and other halogenated styrenes; 4-nitrostyrene, 4-acetylstyrene, 4-methoxystyrene and other functionalized styrene Ene.

Examples of vinyl ether-based monomers include vinyl acetate; alkyl vinyl ethers such as methyl vinyl ether, n-propyl vinyl ether, and n-butyl vinyl ether.

The ratio of other monomers in the polymerizable unsaturated group-containing monomer used to obtain the polymer (B1) is 20% by mass or less, preferably 10% by mass or less.

≪Epoxy compound (B2)≫

Examples of the epoxy compound (B2) include epoxy compounds in which the number of epoxy groups in one molecule is two or more.

The epoxy compound (B2) can be enumerated: for example

Bisphenol A type epoxy resin, Bisphenol E type epoxy resin, Bisphenol F type epoxy resin, Bisphenol S type epoxy resin, Bisphenol O type epoxy resin, Bisphenol AD type epoxy resin and other bisphenols Type epoxy resin, hydrogenated bisphenol type epoxy resin, alkyl substituted bisphenol type epoxy resin, alkylene oxide modified bisphenol type epoxy resin, biphenyl type epoxy resin, resorcinol type epoxy resin , Sulfide type epoxy resin, diphenyl ether type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, phenol novolak type epoxy resin, o-cresol novolak type epoxy resin, two Cyclopentadiene novolac epoxy resin, biphenol novolac epoxy resin, naphthol novolac epoxy resin, glycidyl amine epoxy resin;

Bisphenol A, Bisphenol E, Bisphenol F, Bisphenol S, Bisphenol O, Bisphenol AD and other bisphenols or diglycidyl ether of 4,4-dihydroxybiphenyl [here, the aforementioned bisphenol and the aforementioned combination Benzene can be hydrogenated (e.g. hydrogenated bisphenol), can have alkyl substituents (e.g. alkyl substituted bisphenol), can be modified with ethylene oxide, modified with propylene oxide, etc. and modified with alkylene oxide (For example: modified bisphenol by alkylene oxide)], ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether , 1,8-octanediol diglycidyl ether, 1,10-decanediol diglycidyl ether Ether, 2,2-dimethyl-1,3-propanediol diglycidyl ether and other alkanediol diglycidyl ether, glycerol diglycidyl ether and other alkanetriol diglycidyl ether, diethylene glycol diglycidyl ether , Triethylene glycol diglycidyl ether, tetraethylene glycol diglycidyl ether, hexaethylene glycol diglycidyl ether and other polyalkylene glycol diglycidyl ether, 1,4-cyclohexane dimethanol diglycidyl ether Diglycidyl ether compounds such as diglycidyl ether of dimethanol containing alicyclic rings;

Glycerol triglycidyl ether, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, N,N,N,N'-tetraglycidyl-m-xylene diamine, N,N,N',N'-tetraglycidylaminophenylmethane, triglycidyl isocyanurate, m-N,N-diglycidylaminophenyl glycidyl ether, N ,N-Diglycidyltoluidine, N,N-Diglycidylaniline, 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate, ε-caprolactone Modification of 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate.

Although the epoxy equivalent of the epoxy compound (B2) is not particularly limited, it is preferably 100 to 3,000 g/eq., more preferably 100 to 1,000 g/eq.

The SP value of the carboxyl group-containing (meth)acrylic polymer (B1) is preferably 9.0 to 11.5, and more preferably 9.0 to 11. In addition, the epoxy compound (B2) preferably has an SP value of 10 to 15, and more preferably 11 to 13.5.

From the viewpoint of forming a sea-island phase separation structure of an island phase with an average dispersion diameter of a suitable size, the absolute difference between the SP value of the (meth)acrylic polymer (B1) and the SP value of the epoxy compound (B2) containing carboxyl groups The value is preferably 1.3 to 4.5, more preferably 1.3 to 3.7. In one form, the SP value of the epoxy compound (B2) is subtracted from the SP value of the carboxyl group-containing (meth)acrylic polymer (B1), which is preferably -4.5 to -1.3, and -3.6 To -1.3 is better.

From the viewpoint of forming an island-in-sea phase separation structure of appropriate size, these epoxy compounds (B2) Among them are bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol or diglycidyl ether of 4,4-dihydroxybiphenyl [Here, the aforementioned bisphenol and the aforementioned biphenyl may be Polyalkylene glycol diglycidyl ethers such as hydrogenated, may have alkyl substituents, may be modified by cycloalkoxy], diethylene glycol diglycidyl ether and other polyalkylene glycol diglycidyl ethers are preferred.

≪Production of (meth)acrylic polymer (B)≫

The (meth)acrylic polymer (B) can be produced by a known method, and can be obtained by reacting the carboxyl group-containing (meth)acrylic polymer (B1) with the epoxy compound (B2).

The carboxyl group-containing (meth)acrylic polymer (B1) is not particularly limited, but from the viewpoint of removing impurities, it is preferably produced by bulk polymerization. Specifically, the reaction vessel is filled with a monomer containing a polymerizable unsaturated group, a polymerization initiator, a chain transfer agent and a polymerization solvent if necessary, The reaction temperature is heated to about 50 to 150°C and allowed to react for 2 to 20 hours. In addition, during the polymerization reaction, a monomer containing a polymerizable unsaturated group, a polymerization initiator, a chain transfer agent, and a polymerization solvent may also be appropriately added separately.

Examples of the polymerization initiator include general organic polymerization initiators. Specifically, peroxide compounds and azo compounds can be cited.

Examples of peroxide compounds include: 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, third hexylperoxy-2-ethylhexanoate, third Pentyl-peroxy-2-ethylhexanoate, tert-butylperoxy-2-ethylhexanoate, cumyl peroxyneodecanoate, 1,1,3,3 -Tetramethyl butyl peroxy neodecanoate, tertiary hexyl peroxy neodecanoate, tertiary butyl peroxy neodecanoate, tertiary butyl peroxy neoheptanoate, the first Trihexyl peroxy valerate, tertiary butyl peroxy valerate, 2,5-dimethyl-2,5-bis(2-ethylhexyl peroxy) hexane, 2, 5-Dimethyl-2,5-bis(2-benzylperoxy)hexane, tert-butylperoxy- 3,5,5-Trimethylhexanoate, tertiary butyl peroxy laurate, tertiary hexyl peroxy benzoate.

Examples of azo compounds include: 2,2'-azobisisobutyronitrile, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'- Azobis(2-cyclopropylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylbutyronitrile), 1,1'-Azobis(cyclohexane-1-carbonitrile), 2-(aminoformamide azo)isobutyronitrile, 2-phenylazo-4-methoxy-2,4- Dimethylvaleronitrile, 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis(N,N'-dimethylisobutylamidine), 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)-propanamide], 2,2'-azobis(isobutylamide) divalerate, 4 ,4'-azobis(4-cyanopentanoic acid), 2,2'-azobis(2-cyanopropanol), dimethyl-2,2'-azobis(2-methyl Propyl propionate), 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide].

A polymerization initiator may be used individually by 1 type, and may use 2 or more types.

The amount of the polymerization initiator used is usually 0.01 to 5 parts by mass relative to 100 parts by mass of the monomer containing a polymerizable unsaturated group. In this case, the number average molecular weight (Mn) of the (meth)acrylic polymer (B) can be adjusted to an appropriate range.

In the production of polymer (B1), it is preferable to polymerize monomers containing polymerizable unsaturated groups in the presence of a chain transfer agent. From the standpoint of suppressing bubbles generated when the epoxy resin is cured, to suppress residual monomers, etc. When the low-molecular component remains, it is more preferable to polymerize in the presence of a chain transfer agent having a reactive high-polarity group.

The chain transfer agent having a polar group in the molecule is preferably a thiol chain transfer agent having a polar group in the molecule. The thiol-based chain transfer agent having a polar group in the molecule includes a thiol-based chain transfer agent having one or more polar groups such as a carboxyl group, a hydroxyl group, an amino group, and a sulfonic acid group in the molecule. Among these polar groups, a carboxyl group or a hydroxyl group is preferred. Examples of such thiol chain transfer agents having polar groups in the molecule include carboxyl-containing thiol compounds such as α-mercaptopropionic acid and β-mercaptohydropropionic acid; 1-mercaptoethanol, 2-mercaptoethanol, 1 -Mercaptopropanol and other thiol compounds containing hydroxyl groups. Examples of other chain transfer agents include alkyl mercaptan compounds such as n-octyl mercaptan and n-dodecyl mercaptan.

One type or two or more types of chain transfer agents can be used.

The amount of the chain transfer agent used is preferably 0.1 to 10 parts by mass, and more preferably 3 to 8 parts by mass relative to 100 parts by mass of the monomer containing a polymerizable unsaturated group. In this case, the weight average molecular weight and number average molecular weight of the (meth)acrylic polymer (B) can be adjusted to an appropriate range.

In the solution polymerization, the following solvents can be cited: for example, aromatic hydrocarbons such as benzene, toluene, and xylene; aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, and n-octane; cyclopentane, cyclohexane, Alicyclic hydrocarbons such as cycloheptane and cyclooctane; diethyl ether, diisopropyl ether, 1,2-dimethoxyethane, dibutyl ether, tetrahydrofuran, dioxane, anisole, benzene Ethyl ethyl ether, diphenyl ether and other ethers; chloroform, carbon tetrachloride, 1,2-dichloroethane, chlorobenzene and other halogenated hydrocarbons; ethyl acetate, propyl acetate, butyl acetate, methyl propionate And other esters; acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, cyclohexanone and other ketones; N,N-dimethylformamide, N,N-dimethylacetamide, Ammines such as N-methylpyrrolidone; Nitriles such as acetonitrile and benzonitrile; Subsulfides such as dimethyl sulfoxide and sulfolane.

A polymerization solvent may be used individually by 1 type, and may use 2 or more types.

The (meth)acrylic polymer (B) is preferably made by reacting the epoxy compound (B2) in the range of 0.1 to 500 parts by mass relative to 100 parts by mass of the (meth)acrylic polymer (B1) containing a carboxyl group The resulting polymer is more preferably 5 to 300 parts by mass, still more preferably 10 to 200 parts by mass, It is still more preferably 15 to 100 parts by mass. The cured resin containing the polymer obtained by reacting the epoxy compound (B2) within the above-mentioned range has a sea-island phase separation structure with an appropriate size and is excellent in impact resistance. In addition, when the carboxyl group-containing (meth)acrylic polymer (B1) and the epoxy compound (B2) are reacted, a known epoxy curing catalyst can be used.

In addition, the (meth)acrylic polymer (B) is such that the molar ratio (B1/ B2) is preferably a polymer obtained by reaction in the range of 0.1 to 1, and more preferably a polymer obtained by reaction in the range of 0.3 to 1.

≪The content of (meth)acrylic polymer (B)≫

With respect to 100 parts by mass of epoxy resin (A), the epoxy resin composition of this embodiment preferably contains 0.1 to 70 parts by mass of (meth)acrylic polymer (B), more preferably 10 to 70 parts by mass , And more preferably 10 to 40 parts by mass. From the viewpoint of not impairing the original characteristics of epoxy resin and imparting impact resistance, such a type is preferred.

From the viewpoint of obtaining excellent bonding strength with the metal attached body, the epoxy resin composition of this embodiment contains an epoxy resin (A) and a (meth)acrylic polymer in 100% by mass of its solid content. The total content is preferably 30% by mass or more, more preferably 50% by mass or more, and still more preferably 70% by mass or more. The solid content refers to components other than the solvent described later.

≪Physical properties of (meth)acrylic polymer (B)≫

The (meth)acrylic polymer (B) has an SP value of 9.5 to 11, preferably 9.7 to 10.7. From the viewpoint that the epoxy resin (A) and the (meth)acrylic polymer (B) constitute an island phase separation structure of an island phase having an average dispersion diameter of a suitable size, an SP within the above range is preferred.

The epoxy equivalent of the (meth)acrylic polymer (B) is not particularly limited, but it is relatively It is preferably 100 to 10,000 g/eq., more preferably 500 to 8,000 g/eq. From the viewpoint of making the compatibility between the epoxy resin and the (meth)acrylic polymer (B) excellent, the SP within the above-mentioned range is preferred.

The weight average molecular weight (Mw) of the (meth)acrylic polymer (B) is preferably 3,000 to 100,000, more preferably 3,500 to 80,000.

In addition, the number average molecular weight (Mn) of the (meth)acrylic polymer (B) is preferably 1,500 to 15,000, more preferably 1,500 to 8,000. From the viewpoint that the (meth)acrylic polymer (B) has moderate viscosity and is excellent in usability, in addition, the compatibility with the epoxy resin (A) and the durability of the cured resin obtained are improved, It is preferable that the aforementioned molecular weight meets this condition. The weight average molecular weight (Mw) and number average molecular weight (Mn) can be determined by gel permeation chromatography (GPC). The detailed measurement conditions of the GPC method are as described in the below-mentioned Examples.

The viscosity of the (meth)acrylic polymer (B) measured with an E-type viscometer under the conditions of a liquid temperature of 25°C and a rotation speed of 6 rpm is preferably 150 Pa‧s or less, and more preferably 100 Pa‧s or less. The lower limit of the aforementioned viscosity is not particularly limited, and it is 1Pa‧s in one form.

<hardener (C)>

The epoxy resin composition of this embodiment preferably contains the hardener (C) together with the epoxy resin (A) and the (meth)acrylic polymer (B). The curing agent (C) is, for example, a compound that can cure the epoxy resin composition by reaction with the epoxy resin (A).

Examples of the hardener (C) include polyamines, polycarboxylates, acid anhydrides, and phenols. Other examples include imidazoles, polythiols, and organic acid hydrazides.

Polyamines include: for example, diethylenetriamine, dipropylenetriamine, triethylenetetramine, tetraethylenepentamine, dimethylaminopropylamine, diethylaminopropylamine, dibutyl Aminopropylamine, Aliphatic polyamines such as hexamethylene diamine, trimethyl hexamethylene diamine, bis-(hexamethylene) triamine, polyoxypropylene diamine; 3,3'-dimethyl-4,4' -Diaminodicyclohexylmethane, 3-amino-1-cyclohexylaminopropane, 4,4'-diaminodicyclohexylmethane, isophorone diamine, 1,3-bis(amino) (Methyl) cyclohexane, N-dimethylcyclohexylaminopropane and 4,4'-diaminodicyclohexylaminopropane mixtures and other alicyclic polyamines; 4,4'-diaminodi Phenylmethane, 4,4'-diaminodiphenyl ethyl ether, diaminodiphenyl ether, m-phenylene diamine, 2,4-toluene diamine, 2,6-toluene diamine, 2 ,3-toluene diamine, 3,4-toluene diamine, meta-xylene diamine, xylene diamine and other aromatic polyamines; N-aminoethylpiper and other heterocyclic polyamines; dicyandiamide Amide hardeners such as amide and diacetone acrylamide; these modified products (for example, epoxy adduct, acrylonitrile adduct, ethylene oxide adduct, Mannich reaction Compounds, Michael reactants, thiourea reactants, modified aromatic amines).

Examples of polycarboxylic acids include phthalic acid, hydroxyisophthalic acid, succinic acid, sebacic acid, maleic acid, dodecenyl succinic acid, chlorendic acid, and pyromellitic acid. , Trimellitic acid, hexahydrophthalic acid, methylhexahydrophthalic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, methyl nadic acid.

Examples of acid anhydrides include maleic anhydride, dodecenyl succinic anhydride, chloro bridged anhydride, sebacic anhydride, phthalic anhydride, pyromellitic anhydride, trimellitic anhydride, cyclopentane‧tetracarboxylic acid dihydrate, Hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, tetramethylene phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, endomethine tetrahydro Phthalic anhydride, Methylendomethyltetrahydrophthalic anhydride, 5-(2,5-dioxotetrahydroxyfuranyl)-3-methyl-3-cyclohexene-1,2- Dicarboxylic anhydride, methyl Nadic anhydride.

Phenols can be enumerated: for example, bisphenol A, bisphenol F, bisphenol S, bisphenol bisphenol AD, Hydroquinone, resorcinol, methyl resorcinol, diphenol, tetramethyl diphenol, dihydroxy naphthalene, dihydroxy diphenyl ether, thiodiphenols, phenol phenol resin, cresol phenol resin, Phenol aralkyl resin, biphenyl aralkyl resin, naphthyl aralkyl resin, terpene phenol resin, dicyclopentadiene phenol resin, bisphenol A phenol resin, phenol methane type resin, naphthyl phenol resin , Brominated bisphenol A, brominated phenol phenol resin and other polyphenols, or polyphenols obtained by the condensation reaction of various phenols with various aldehydes such as benzaldehyde, hydroxybenzaldehyde, crotonaldehyde, glyoxal, etc. Polyphenol resins, heavy oils or pitches, co-condensation resins between phenols and formaldehyde, phenols, benzaldehydes, xylene dimethyl oxides obtained from the condensation reaction between resins, xylene resins and phenols Polycondensate, phenol‧benzaldehyde‧xylene dihalide polycondensate, phenol‧benzaldehyde‧4,4'-dimethoxide biphenyl polycondensate, phenol‧benzaldehyde‧4,4'-dihalogenation Various phenol resins such as biphenyl polycondensates.

Examples of imidazoles include: 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl 2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1 -Cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2 ,4-Diamino-6-[2'-Methylimidazole-(1')]-Ethyl-s-Tris, 2,4-Diamino-6-[2'-Ethyl-4'- Methylimidazole-(1')]-ethyl-s-tri, 2,4-diamino-6-[2'-methylimidazole-(1')]-ethyl-s-triheterotrimer Cyanate adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethyl Imidazole.

Among these hardeners (C), in one form, polyamines, amide hardeners, and imidazoles are preferable, and aliphatic polyamines and modified products of aliphatic polyamines are more preferable.

The curing agent (C) may be used singly or in two or more types.

In one aspect of the epoxy resin composition of this embodiment, the curing agent (C) preferably contains 0.01 to 10 equivalents, and more preferably contains 0.1 to 5 equivalents, based on the equivalent ratio of the epoxy resin (A). The equivalent is more preferably 0.5 to 2 equivalents. From the standpoint of hardening, this type is better.

<Cationic or Anionic Polymerization Initiator>

The epoxy resin composition of this embodiment may replace the hardener (C) or contain a cationic or anionic polymerization initiator together with the hardener (C). The cationic or anionic polymerization initiator is a compound that can initiate and/or promote the hardening reaction of the epoxy resin (C) by heating or light.

The cationic polymerization initiator may be one that can generate cationic species such as Bronsted acid and Lewis acid (Bronsted acid, Lewis acid) by heating or light, and examples thereof include onium salts, protic acid esters, and Lewis acids. Compound. A cationic polymerization initiator may be used individually by 1 type, and may use 2 or more types.

The anionic polymerization initiator may be any one that can generate anionic species such as Brookfield bases and Lewis bases by heating or light, and examples thereof include imidazoles and tertiary amines. Anionic polymerization initiator may be used individually by 1 type, and may use 2 or more types.

In one form, the epoxy resin composition of this embodiment preferably contains 0.001 to 50 parts by mass of the cationic or anionic polymerization initiator relative to 100 parts by mass of the epoxy resin (A), and more preferably contains 0.01 To 30 parts by mass, and more preferably 0.1 to 10 parts by mass. From the standpoint of hardening, this type is better.

<Additives>

The epoxy resin composition of this embodiment may optionally contain ultraviolet absorbers, antioxidants Chemical agents, preservatives, rust inhibitors, pigments, tackifiers, surface lubricants, gloss agents, water repellents, photosensitizers, organic and inorganic fibers, plasticizers, conductive fillers, inorganic fillers, flame retardants, At least one additive of antistatic agent, foam stabilizer, release agent, colorant and foaming agent. The additives may be used singly or in two or more types.

<Solvent>

The epoxy resin composition of this embodiment may contain a solvent. Examples of the solvent include the solvents exemplified as the aforementioned polymerization solvent in the production method of the (meth)acrylic polymer (B), or reactive diluents such as epoxy compounds having 1 epoxy group per molecule.

A solvent may be used individually by 1 type, and may use 2 or more types.

The content ratio of the solvent in the epoxy resin composition of this embodiment is usually 70% by mass or less, preferably 30% by mass or less, and more preferably 20% by mass or less.

[Use of epoxy resin composition]

By using the epoxy resin composition of this embodiment, a cured resin having sufficient elastic modulus and impact resistance can be formed.

Since the epoxy resin composition of this embodiment has the aforementioned characteristics, it can be used for applications such as electronic materials, adhesives, paints, and adhesives. Specifically, examples include substrate substrates for electronic components such as semiconductor packages, buildup films, solder masks, underfill materials, solid sealing materials for packaging, adhesives for road paving, adhesives for carbon fiber reinforced plastic (CFRP), and cations. Electrodeposition coatings, heavy anticorrosive coatings, powder coatings, adhesives for infrastructure repair/reinforcement, and general household/industrial adhesives. The epoxy resin composition of this embodiment is suitable for these applications.

[Resin Cured Material]

One embodiment of the hardened resin of the present invention (hereinafter also referred to as "the hardened resin of this embodiment" "The compound") is obtained by curing the epoxy resin composition of this embodiment.

The cured resin of this embodiment preferably has a sea-island phase separation structure.

In addition, the above-mentioned sea-island phase separation structure is based on the composition derived from the epoxy resin (A) as the sea phase (continuous phase), preferably dispersed from (meth)acrylic acid polymerization as the island phase (dispersed phase) The structure of 物(B).

In the sea-island phase separation structure of the resin cured product of this embodiment, the average dispersion diameter of the island phase is preferably 0.01 to 0.84 μm, more preferably 0.03 to 0.80 μm. When the average dispersion diameter of the island phase is within the above range, the original elastic modulus of the epoxy resin can be maintained and the impact resistance of the cured resin can be improved. If the average dispersion diameter of the island phase is less than 0.01 μm or exceeds 0.84 μm, the original elastic modulus of the epoxy resin tends to decrease significantly.

The cured resin obtained by curing the epoxy resin composition of this embodiment has a sea-island phase separation structure. Scanning electron microscope, atomic force microscope, etc. observe and confirm the cut surface.

The tensile elastic modulus (X) of the resin cured product of this embodiment and the tensile elastic modulus (Y) of the resin cured product without the (meth)acrylic polymer (B) of this embodiment are given by It is preferable to satisfy the following formula (2).

0.6≦X/Y≦1.1‧‧‧(2)

The lower limit of the formula (2) is preferably 0.7 or more, more preferably 0.75 or more, and even more preferably 0.8 or more. The upper limit of the formula (2) is more preferably 1.08 or less, and more preferably 1.05 or less.

In the curable composition composed of epoxy resin, the original elastic modulus of the epoxy resin is changed when the modifier is formulated to improve the impact resistance. Therefore, in the system with modifier The elasticity must be adjusted again.

In the cured resin of this embodiment, even when a modifier ((meth)acrylic polymer (B)) is blended, since the above formula (2) is satisfied, the elastic modulus of the cured product can be adjusted without adjusting the modifier ((meth)acrylic polymer (B)) Improve impact resistance.

The method of curing the epoxy resin composition of the present embodiment includes, for example, a method of mixing the components to prepare the epoxy resin composition of the present embodiment, and then performing a curing reaction by heating or light.

The aforementioned mixing system is performed using, for example, a mixer, agitator, and a roller.

During thermal curing, the heating temperature (curing temperature) during curing is usually 20 to 300°C, preferably 40 to 250°C, more preferably 60 to 200°C. In addition, the heating time (hardening time) during hardening is usually 10 to 1,440 minutes, preferably 30 to 900 minutes, and more preferably 60 to 480 minutes. The aforementioned heating can be performed in multiple stages.

For light curing, light such as ultraviolet rays, visible rays, and infrared rays can be cited, and ultraviolet rays are preferred. 1 to an exposure amount based 10,000mJ / cm ² preferably, 10 to 3,000mJ / cm ² more preferably. Examples of light sources include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, xenon lamps, metal halide lamps, chemical lamps, black fluorescent lamps, and electrodeless UV lamps.

The aforementioned curing reaction can be carried out by coating the epoxy resin composition of this embodiment on a substrate, or by injecting it into a mold.

The shape of the resin cured product of this embodiment is not particularly limited, and examples thereof include a plate shape, a sheet shape, and a film shape. These thicknesses are usually, for example, 0.01 to 1,000 mm, preferably 0.1 to 100 mm.

In addition, another embodiment of the cured resin of the present invention is to contain epoxy The epoxy resin composition of the resin and the (meth)acrylic polymer is cured to obtain a cured resin having a sea-island phase separation structure, wherein the average dispersion diameter of the island phase is 0.01 to 0.84 μm. Here, the epoxy resin composition containing an epoxy resin and a (meth)acrylic polymer is preferably the epoxy resin composition of the above-mentioned embodiment.

The tensile elastic modulus (X) of the resin cured product of the above-mentioned other embodiment and the tensile elastic modulus (Y) of the resin cured product without the (meth)acrylic polymer satisfy the following formula (2) ) Is better.

0.6≦X/Y≦1.1‧‧‧(2)

The lower limit of the formula (2) is preferably 0.7 or more, more preferably 0.75 or more, and still more preferably 0.8 or more. The upper limit of the formula (2) is more preferably 1.08 or less, and still more preferably 1.05 or less.

[Example]

Hereinafter, although the present invention is described in more detail based on examples, the present invention is not limited to the scope of these examples. In the description of the following examples and the like, unless otherwise specified, "parts" means "parts by mass".

<SP value>

The SP value of each component is from Robert F. Fcdors., "POLYMER ENGINEERING AND SCIENCE", 1974, Vol. 1, No. 2, the total of the Mole 6 evaporation heat (△ei) of the atomic group described on pages 151 to 153 (△ The total (V) of H) and the molar volume (△vi) is calculated.

<Weight average molecular weight (Mw), number average molecular weight (Mn)>

The weight average molecular weight (Mw) and number average molecular weight (Mn) of the polymer were analyzed by the gel permeation chromatography (GPC) method, and calculated by converting polystyrene under the following conditions.

‧Equipment: GPC-8220 (made by Tosoh)

‧Separation column: G7000HXL/7.8mm ID×1+

GMHXL/7.8mm ID×2pcs+

G2500 HXL/7.8mm ID×1

‧Solvent: Tetrahydrofuran

‧Flow rate: 1.0mL/min

‧Concentration: 1.5mg/mL

‧Injection volume: 300μL

‧Column temperature: 40℃

<Viscosity>

Under the conditions of a liquid temperature of 25°C and a rotation speed of 6 rpm, the viscosity of each polymer was measured with an E-type viscometer VISCONIC EHD type (manufactured by Tokyo Keiki).

<Epoxy equivalent>

The epoxy equivalent of the polymer is determined based on JIS K7236.

[Manufacturing Example 1]

Add 62.1 parts of 2-ethylhexyl acrylate, 2.5 parts of acrylic acid, and 4.3 parts of β-mercaptopropionic acid to a flask equipped with a stirring device, nitrogen introduction tube, thermometer, and reflux cooling tube, and stir while introducing nitrogen into the flask After replacing the nitrogen for 30 minutes, the content of the flask was heated to 60°C. Next, while maintaining the content of the flask at 60°C, 0.06 part of azobisisobutyronitrile was added to start the reaction. Then, 0.06 parts of azobisisobutyronitrile was added 6 times every 1 hour to react, and then reacted at 100°C to 125°C for 3 hours, and the volatile components in the product were distilled off under reduced pressure to obtain A (meth)acrylic polymer (B1-1) containing a carboxyl group. Next, put bisphenol A epoxy resin ("jER828", manufactured by Mitsubishi Chemical, SP value = 12.8) into the aforementioned flask 31.1 parts and an appropriate amount of epoxy hardening catalyst (triphenylphosphine, "Hokuko-TPP", manufactured by Beixing Chemical Co., Ltd.) as the epoxy compound (B2), were stirred at 110°C for 8 hours. Then, it cooled to room temperature and obtained (meth)acrylic acid polymer (B1-1). The (meth)acrylic polymer (B1-1) had an SP value of 10.2, Mw of 5,814, Mn of 3,342, viscosity of 40.2 Pa‧s, and epoxy equivalent of 2,316 g/eq.

[Manufacturing Examples 2 to 15, 20, 21]

Except for changing to the composition shown in Table 1, (meth)acrylic polymers (B-2) to (B-15), (cB-5), (cB-6) were obtained in the same manner as in Production Example 1. . Table 1 lists the SP value, Mw, Mn, viscosity, and epoxy equivalent of each polymer.

[Manufacturing Example 16]

A flask equipped with a stirring device, a nitrogen introduction tube, a thermometer, and a reflux cooling tube was charged with 100 parts of methyl ethyl ketone, 92 parts of 2-ethylhexyl propionate, 6 parts of glycidyl methacrylate were added, After 2 parts of n-dodecyl mercaptan was introduced into the flask while stirring for 30 minutes to perform nitrogen substitution, the content of the flask was heated to 60°C. Next, while maintaining the contents of the flask at 60°C, 0.2 part of azobisisobutyronitrile was added to start the reaction. After reacting for 3 hours, another 0.2 part of azobisisobutyronitrile was added, and then reacted at 75 to 80°C for 5 hours to obtain an epoxy group-containing (meth)acrylic polymer (cB-1). The (meth)acrylic polymer (cB-1) has an SP value of 9.4, Mw of 14,588, Mn of 7,521, viscosity of 42.1 Pa‧s, and epoxy equivalent of 1,872 g/eq.

[Manufacturing Examples 17 to 19]

Except changing to the composition shown in Table 1, the reaction was carried out under the same conditions as in Production Example 16 to obtain epoxy group-containing (meth)acrylic polymers (cB-2), (cB-3), and (cB- 4). The SP value, molecular weight, viscosity, and epoxy equivalent are shown in Table 1.

[Table 1]

(※1) In Table 1, in the case of (meth)acrylic polymers (cB-1) to (cB-4), instead of using components B1 and B2, epoxy-containing (methyl) groups are used Acrylate is used as a comparative polymer, but it is sorted in the column of "B1" for convenience.

The meanings of the abbreviations for each monomer, chain transfer agent, and epoxy compound are as follows.

‧BA: n-butyl acrylate

‧2EHA: 2-Ethylhexyl Acrylate

‧GMA: Glycidyl methacrylate

‧AA: Acrylic

‧MAA: Methacrylic acid

‧BMPA: β-mercaptopropionic acid

‧NOM: n-octyl mercaptan

‧NDM: n-dodecyl mercaptan

‧JER828: Bisphenol A epoxy resin (manufactured by Mitsubishi Chemical)

‧Epolight 100E: Diethylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical)

‧Epolight 3002N: Bisphenol A PO (propylene oxide) 2mol adduct diglycidyl ether (manufactured by Kyoeisha Chemical)

These SP values are listed in Table 1.

[Example 1]

100 parts of bisphenol A epoxy resin (trade name "jER828", manufactured by Mitsubishi Chemical), 40 parts of (meth)acrylic polymer (B-1), and aliphatic polyamine hardener (trade name "ST12") , Mitsubishi Chemical Corporation) 50 parts were mixed with a rotation and revolution mixer (product name "Awatori Nentaro", manufactured by Shinky) to obtain an epoxy resin composition.

[Examples 2 to 18, Comparative Examples 1 to 6, Reference Examples 1 to 3]

Except having changed to the preparation composition shown in Table 2-1 and Table 2-2 (hereinafter, these are collectively referred to as "Table 2"), the same operation as in Example 1 was performed to obtain an epoxy resin composition. The composition conditions and the evaluation results are listed in Table 2. In Table 2, "113" is jRE Cure 113 (modified alicyclic amine, manufactured by Mitsubishi Chemical), "DICY15" is jRE Cure DICY15 (finely pulverized dicyandiamide, manufactured by Mitsubishi Chemical), and "2E4MZ" is Curesol 2E4MZ (imidazole, manufactured by Shikoku Chemical Industry).

[table 2-1]

[Table 2-2]

(※2) In Table 2, it is the case of Comparative Examples 1 to 4, instead of using B1 and B2 components, a polymer containing epoxy group (meth)acrylate is used as a comparative polymer (cB-1 ) To (cB-4), the SP value is collated and described as the SP value of "(B) component" for convenience. Similarly, the SP value "absolute value of the difference between component (A) and component (B)" in Comparative Examples 1 to 4 is calculated based on the SP value of (cB-1) to (cB-4) .

[Evaluate]

<Tensile modulus of pendulum test piece>

The epoxy resin compositions obtained in the examples, comparative examples, and reference examples were poured into SUS metal molds. For Examples 1 to 13, Reference Examples 1, 2 and Comparative Examples 1 to 6, they were kept at 80°C. After curing for 3 hours, Examples 14 to 18 and Reference Example 3 were cured at 150°C for 1 hour to prepare pendulum test pieces. The tensile modulus is based on JIS-K7161 and measured under the following conditions.

‧Sample size: pendulum size 1A

‧Test speed: 10mm/min

‧Measurement environment: temperature 23℃, humidity 50%RH

‧Measured value: measured 3 times and calculated from the average

In addition, the tensile elastic modulus (X) of the pendulum test piece obtained in the Examples and Comparative Examples and the tensile elastic modulus (Y) of the resin cured product of Reference Example 1 or 2 were used as a reference to calculate the tensile modulus ( The ratio of X) to the tensile elastic modulus (Y) (tensile elastic modulus (X)/tensile elastic modulus (Y)) is used as a change index of the elastic modulus of the curable composition prepared with the modifier. In addition, in the respective Examples and Comparative Examples, the formulation composition of the epoxy resin (A) and the curing agent (C) is based on the same reference example.

<Shear Adhesion Strength>

According to JIS-K6850, the epoxy resin composition obtained in each example, comparative example and reference example was coated on a test piece with a thickness of 0.2mm, just like making two test pieces (the same SUS plate or Fe plate) separately The ends were overlapped by 12.5mm, and the resin composition layer was sandwiched between the test pieces and overlapped. For Examples 1 to 13, Reference Examples 1, 2 and Comparative Examples 1 to 6, they were dried at 80°C for 3 hours. At this time, for Examples 14 to 18 and Reference Example 3, they were dried at 150°C for 1 hour to obtain adhesive test pieces for evaluation fixed with an epoxy resin composition.

Using the aforementioned adhesion test piece for evaluation, a tensile shear adhesion test was performed. The tensile testing machine is the universal tensile testing machine AG-X manufactured by Shimadzu.

‧Sample size: According to JIS-K6850

‧Test speed: 200mm/min

‧Measurement environment: temperature 23℃, humidity 50%RH

‧Measured value: measured 3 times and calculated from the average

<Average dispersion diameter of island phase>

Using SEM (product name "S-4800", manufactured by Hitachi High-Tech), the sea-island structure of the fractured surface of the test piece broken in the tensile elastic modulus test of the aforementioned pendulum test piece was observed at a magnification of 10,000 times. Analyze and observe the SEM image using the average particle size analysis software (product name "Fine-View", manufactured by Astron), and measure the band diameter (9.2μm×12.7μm) of the island phase (dispersed phase) in the captured SEM image ( ferret diameter). Specifically, the island phase (dispersed phase) is sandwiched by parallel lines in a certain direction, and the distance between the parallel lines is measured. The number average value of the aforementioned band diameters of the measured island phases is taken as the average dispersion diameter of the island phases.

<Viscosity of Hardened Material>

After leaving the aforementioned pendulum test piece on the PER film at 25°C and 50%RH for 24 hours, visually confirm the PER film of the pendulum test piece and the surface on which it is installed, and the PER film of the part that bears the pendulum test piece. Evaluate in accordance with the following evaluation criteria.

AA: There is no change in the appearance of the test piece surface, and the transfer on the PER film cannot be confirmed.

BB: It can be confirmed that there is leakage in the PER film from part of the surface of the test piece.

CC: From the entire surface of the test piece, it can be confirmed that there is leakage in the PER film.

<Shock Resistance Test>

According to JIS-K6850, the epoxy resin composition obtained in each example, comparative example and reference example was coated on the test piece with a thickness of 0.2mm, as if the respective ends of the two test pieces were overlapped by 12.5mm to make the resin composition The layers of the object were sandwiched between the test pieces and overlapped. For Examples 1 to 13, Reference Examples 1, 2 and Comparative Examples 1 to 6, they were dried at 80°C for 3 hours. For Examples 14 to 18 and Reference Example 3 It was dried at 150°C for 1 hour to obtain an adhesive test piece for evaluation fixed with an epoxy resin composition.

Using the aforementioned adhesive test piece for evaluation, a drop impact test was performed. The type of test adopts DuPont type. As with the test piece where the distance between the pallet and the adhesive layer of the epoxy resin composition is 50 mm, a load of 1 kg is placed on the adhesive test piece for evaluation with a height of 10 to 30 cm between 10 cm and 30 cm. Check whether the bonding surface is damaged, and evaluate the impact resistance based on the height of gravity based on the following evaluation criteria.

AA: It is not damaged even at 30 cm.

BB: No damage at 20 cm, but damage at 30 cm.

CC: No damage at 10 cm, but damage at 20 cm.

DD: Damaged at a height of 10 cm.

<Review>

Comparative Examples 1 to 4 used epoxy group-containing (meth)acrylic polymers as modifiers for epoxy resins. In these epoxy group-containing (meth)acrylic polymers, the epoxy group is introduced into the polymer by using glycidyl methyl (meth)acrylate as a monomer component. These polymers are not obtained by reacting epoxy-containing (meth)acrylic polymers with epoxy compounds 的polymers. In Comparative Examples 1 to 4, the impact resistance of the obtained cured resin was not sufficiently improved.

In Comparative Examples 5 and 6, a polymer obtained by reacting an epoxy group-containing (meth)acrylic polymer and an epoxy compound was used as a modifier for epoxy resin. However, since the SP value is as low as 9.4 or as high as 11.8, the impact resistance of the resulting resin cured product is not sufficiently improved.

In contrast, in the examples, a polymer having an SP value in a specific range obtained by reacting a carboxyl group-containing (meth)acrylic polymer and an epoxy compound is used as a modifier for the epoxy resin. In addition, the difference in SP value between epoxy resin and modifier is also within a specific range. In the examples, a cured resin having excellent impact resistance was obtained.

Claims (8)

An epoxy resin composition containing an epoxy resin (A) with a solubility parameter (SP value) of 11 to 15, and The (meth)acrylic polymer (B) having an SP value of 9.5 to 11, wherein The aforementioned (meth)acrylic polymer (B) is a reaction product of a carboxyl group-containing (meth)acrylic polymer (B1) and an epoxy compound (B2), and The absolute value of the difference between the SP value of the aforementioned (meth)acrylic polymer (B) and the SP value of the aforementioned epoxy resin (A) is 0.1 to 3.3. The epoxy resin composition according to claim 1, which contains 0.1 to 70 parts by mass of the (meth)acrylic polymer (B) with respect to 100 parts by mass of the epoxy resin (A). The epoxy resin composition according to claim 1 or 2, wherein the absolute value of the difference between the SP value of the carboxyl group-containing (meth)acrylic polymer (B1) and the SP value of the epoxy compound (B2) From 1.3 to 4.5. The epoxy resin composition according to any one of claims 1 to 3, wherein the weight average molecular weight of the (meth)acrylic polymer (B) is 3,000 to 100,000. The epoxy resin composition according to any one of claims 1 to 4, which further contains a hardener (C). A hardened resin is composed of the epoxy resin composition described in any one of claims 1 to 5. A cured resin is obtained by curing an epoxy resin composition containing an epoxy resin and a (meth)acrylic polymer, and has a sea-island phase separation structure, wherein the average dispersion diameter of the island phase is 0.01 to 0.84 μm. The resin cured product according to claim 7, wherein the tensile elastic modulus (X) of the resin cured product and the tensile elastic modulus (Y) of the resin cured product without the (meth)acrylic polymer are based on Satisfy the following formula (2) 0.6≦X/Y≦1.1‧‧‧(2).