Sclerotic resin composition, and method for suppressing curing shrinkage of sclerotic resin composition

Abstract

The purpose of the present invention is to provide a curable resin composition with suppressed curing shrinkage.　The present invention is a curable resin composition containing (A) an epoxy resin, (B) a latent curing agent, and (C) a compound represented by formula (1). (In the formula, X represents an oxygen atom or a sulfur atom, R1 and R2 each independently represent hydrogen, an alkyl group, or an aryl group, and R3 and R4 each independently represent a hydrogen atom, an alkyl group, or an aryl group, or represent divalent groups which can be linked to each other to form a ring structure.)

Description

Technical Field

[0001] The present invention relates to a curable resin composition, and more particularly to a curable resin composition containing an epoxy resin, a latent curing agent, and a specific urea compound, which has suppressed curing shrinkage.

Background Art

[0002] Epoxy resins are widely used industrially in paints, adhesives, various molding materials, and the like.

[0003] Furthermore, when existing epoxy resins are used alone or in combination and are insufficient, a cyanate-epoxy composite resin composition obtained by mixing an epoxy resin and a cyanate ester resin has been increasingly used as a useful material because of its high heat resistance. For example, Patent Documents 1 to 5 propose resin compositions comprising a cyanate ester resin, an epoxy resin, and a latent curing agent.

[0004] However, curable resin compositions obtained by containing an epoxy resin or the like may cause problems such as cracks or warping after curing due to curing shrinkage during curing.

[0005] Various studies have been made to suppress curing shrinkage. For example, Patent Documents 6 to 8 propose methods using a silica filler, but the effects are not yet satisfactory.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

[0007] Accordingly, the problem to be solved by the present invention is to provide a curable resin composition with suppressed curing shrinkage.

[0008] Therefore, the present inventors have conducted intensive studies and found that a curable resin composition containing an epoxy resin, a latent curing agent, and a specific urea compound or thiourea compound can achieve the above object, and thus have reached the present invention.

[0009] That is, the present invention provides a curable resin composition containing (A) an epoxy resin, (B) a latent curing agent, and (C) a compound represented by the following formula (1).

[0010] [Chemical Formula] (In the formula, X represents an oxygen atom or a sulfur atom, R 1 and R 2 each independently represents hydrogen, an alkyl group, or an aryl group, and R 3 and R 4 each independently represents a hydrogen atom, an alkyl group, or an aryl group, or these may be linked to form a divalent group capable of forming a ring structure.)

[0011] Further, the present invention provides a cured product of the curable resin composition.

[0012] Furthermore, the present invention provides a method for suppressing shrinkage of a cured product produced from a curable resin composition containing (A) an epoxy resin and (B) a latent curing agent by curing the curable resin composition in the presence of the component (C).

[0013] According to the present invention, since it is possible to suppress the curing shrinkage of the curable resin composition, it becomes possible to apply these as adhesives, paints, and molded articles.

Embodiments for Carrying Out the Invention

[0014] The curable resin composition of the present invention will be described below.

[0015] As the (A) epoxy resin used in the present invention, there are polyglycidyl ether compounds of mononuclear polyhydric phenol compounds such as hydroquinone, resorcinol, pyrocatechol, phloroglucinol; dihydroxynaphthalene, biphenol, methylenebisphenol (bisphenol F), methylenebis(orthocresol), ethylidenebisphenol, isopropylidenebisphenol (bisphenol A), isopropylidenebis(orthocresol), tetrabromobisphenol A, 1,3-bis(4-hydroxyt-butylbenzene), 1,4-bis(4-hydroxyt-butylbenzene), 1,1,3-tris(4-hydroxyphenyl)butane, 1,1,2,2-tetra(4-hydroxyphenyl)ethane, thiobisphenol, sulfobisphenol, oxybisphenol, phenol novolak, orthocresol novolak, ethylphenol novolak, butylphenol novolak, octylphenol novolak, resorcinol novolak, terpene phenol and other polyglycidyl ether compounds of polynuclear polyhydric phenol compounds; polyglycidyl ether compounds of polyhydric alcohol compounds such as ethylene glycol, propylene glycol, butylene glycol, hexanediol, polyethylene glycol, polypropylene glycol, thioglycol, dicyclopentadiene dimethanol, 2,2-bis(4-hydroxycyclohexyl)propane (hydrogenated bisphenol A), glycerin, trimethylolpropane, pentaerythritol, sorbitol, bisphenol A-alkylene oxide adducts; glycidyl esters of aliphatic, aromatic or alicyclic polybasic acids such as maleic acid, fumaric acid, itaconic acid, succinic acid, glutaric acid, suberic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, trimer acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, pyromellitic acid, tetrahydrophthalic acid, endomethylenetetrahydrophthalic acid; homopolymers or copolymers of glycidyl methacrylate;Epoxy compounds having glycidylamino groups such as N,N-diglycidylaniline, bis(4-(N-methyl-N-glycidylamino)phenyl)methane, diglycidyl orthotoluidine, N,N-bis(2,3-epoxypropyl)-4-(2,3-epoxypropoxy)-2-methylaniline, N,N-bis(2,3-epoxypropyl)-4-(2,3-epoxypropoxy)aniline, N,N,N’,N’-tetra(2,3-epoxypropyl)-4,4-diaminodiphenylmethane; Epoxidized products of cyclic olefin compounds such as vinylcyclohexene diepoxide, cyclopentadiene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6-methylcyclohexanecarboxylate, bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate; Epoxidized conjugated diene polymers such as epoxidized polybutadiene, epoxidized styrene-butadiene copolymer; Heterocyclic compounds such as triglycidyl isocyanurate are included.; Also, these epoxy resins can be used in a form internally crosslinked with an isocyanate group-terminated urethane prepolymer, or in a form having a high molecular weight with a polyvalent active hydrogen compound (polyvalent phenol, polyamine, carbonyl group-containing compound, polyphosphoric acid ester, etc.). These epoxy resins may be used alone or in combination of two or more kinds.

[0016] In the curable resin composition of the present invention, other curable resins can be used together with the (A) epoxy resin. In particular, from the viewpoint of obtaining a highly heat-resistant product, it is preferable to use the (D) cyanate ester resin.

[0017] The (D) cyanate ester resin may be a compound having two or more cyanate groups, and can be used without particular limitation on the molecular structure, molecular weight, etc.

[0018] As the cyanate ester resin, for example, compounds represented by the following formula (2), compounds represented by the following formula (3), and polymers thereof are mentioned, and it is preferable to use at least one selected from the group consisting of these. Here, as the polymer, those obtained by self-polymerization of the cyanate ester resin, those having a higher molecular weight due to partial triazine formation of the cyanate group, etc. are mentioned.

[0019]

Chemical formula

[0020]

Chemical formula

[0021] Y 1 in the formula (2) and Y 2 and Y 3 in the formula (3) preferably have a structure represented by any of the following formulas (Y-1) to (Y-9).

[0022]

Chemical formula

[0023] Among the cyanate ester resins showing the above specific examples, the compound represented by the formula (2) is preferable because of the good balance between curability and the effect of suppressing curing shrinkage.

[0024] In the curable resin composition of the present invention, it is preferable to use 10 to 1000 parts by mass, preferably 20 to 500 parts by mass of (D) cyanate ester resin with respect to 100 parts by mass of (A) epoxy resin, because a well-balanced curable resin composition can be obtained.

[0025] Examples of the (B) latent curing agent used in the present invention include dibasic acid dihydrazides such as oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, phthalic acid dihydrazide; guanidine compounds such as dicyandiamide, benzoguanamine, acetoguanamine; melamine; modified amines such as dehydration condensates of amines and carboxylic acids, adducts of amines and epoxies, adducts of amines and isocyanates, Michael adducts of amines, Mannich reaction products of amines, condensates of amines and ureas, condensates of amines and ketones.

[0026] Among the above latent curing agents, guanidine compounds such as dicyandiamide, benzoguanamine, acetoguanamine; modified amines obtained by reacting an amine compound having one or more active hydrogens with an epoxy compound (B-1), modified amines obtained by reacting an amine compound having one or more active hydrogens with an isocyanate compound (B-2), modified amines obtained by reacting an amine compound having one or more active hydrogens with an epoxy compound and an isocyanate compound (B-3), and amine-based latent curing agents such as compositions containing at least one modified amine selected from (B-1), (B-2) or (B-3) and a phenolic resin are mentioned as suitable ones.

[0027] Examples of the amine compound having one or more active hydrogens include alkylene diamines such as ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,3-diaminobutane, 1,4-diaminobutane, hexamethylenediamine; polyalkyl polyamines such as diethylenetriamine, triethylenetriamine, tetraethylenepentamine; alicyclic polyamines such as 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 1,3-diaminomethylcyclohexane, 1,2-diaminocyclohexane, 1,4-diamino-3,6-diethylcyclohexane, 4,4'-diaminodicyclohexylmethane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 4,4'-diaminodicyclohexylpropane, bis(4-aminocyclohexyl)sulfone, 4,4'-diaminodicyclohexyl ether, 2,2'-dimethyl-4,4'-diaminodicyclohexylmethane, isophoronediamine, norbornenediamine; aromatic polyamines such as m-xylylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diethyltoluenediamine, 1-methyl-3,5-diethyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,6-diaminobenzene, 1,3,5-triethyl-2,6-diaminobenzene, 3,3'-diethyl-4,4'-diaminodiphenylmethane, 3,5,3',5'-tetramethyl-4,4'-diaminodiphenylmethane; guanamines such as benzoguanamine, acetoguanamine; imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-isopropylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-aminopropylimidazole; dihydrazides such as oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, phthalic acid dihydrazide;N,N-Dimethylaminoethylamine, N,N-Diethylaminoethylamine, N,N-Diisopropylaminoethylamine, N,N-Diallylaminoethylamine, N,N-Benzylmethylaminoethylamine, N,N-Dibenzylaminoethylamine, N,N-Cyclohexylmethylaminoethylamine, N,N-Dicyclohexylaminoethylamine, N-(2-Aminoethyl)pyrrolidine, N-(2-Aminoethyl)piperidine, N-(2-Aminoethyl)morpholine, N-(2-Aminoethyl)piperazine, N-(2-Aminoethyl)-N'-methylpiperazine, N,N-Dimethylaminopropylamine, N,N-Diethylaminopropylamine, N,N-Diisopropylaminopropylamine, N,N-Diallylaminopropylamine, N,N-Benzylmethylaminopropylamine, N,N-Dibenzylaminopropylamine, N,N-Cyclohexylmethylaminopropylamine, N,N-Dicyclohexylaminopropylamine, N-(3-Aminopropyl)pyrrolidine, N-(3-Aminopropyl)piperidine, N-(3-Aminopropyl)morpholine, N-(3-Aminopropyl)piperazine, N-(3-Aminopropyl)-N'-methylpiperazine, 4-(N,N-Dimethylamino)benzylamine, 4-(N,N-Diethylamino)benzylamine, 4-(N,N-Diisopropylamino)benzylamine, N,N,-Dimethylisophoronediamine, N,N-Dimethylbisaminocyclohexane, N,N,N'-Trimethylethylenediamine, N'-Ethyl-N,N-dimethylethylenediamine, N,N,N'-Trimethylethylenediamine, N'-Ethyl-N,N-dimethylpropanediamine, N'-Ethyl-N,N-dibenzylaminopropylamine;N,N-(Bisaminopropyl)-N-methylamine, N,N-bisaminopropylethylamine, N,N-bisaminopropylpropylamine, N,N-bisaminopropylbutylamine, N,N-bisaminopropylpentylamine, N,N-bisaminopropylhexylamine, N,N-bisaminopropyl-2-ethylhexylamine, N,N-bisaminopropylcyclohexylamine, N,N-bisaminopropylbenzylamine, N,N-bisaminopropylallylamine, bis[3-(N,N-dimethylaminopropyl)]amine, bis[3-(N,N-diethylaminopropyl)]amine, bis[3-(N,N-diisopropylaminopropyl)]amine, bis[3-(N,N-dibutylaminopropyl)]amine and the like can be mentioned.;

[0028] Examples of the epoxy compound include polyglycidyl ether compounds of mononuclear polyhydric phenol compounds such as hydroquinone, resorcinol, pyrocatechol, phloroglucinol; polyglycidyl ether compounds of polynuclear polyhydric phenol compounds such as dihydroxynaphthalene, biphenol, methylenebisphenol (bisphenol F), methylenebis(orthocresol), ethylidenebisphenol, isopropylidenebisphenol (bisphenol A), isopropylidenebis(orthocresol), tetrabromobisphenol A, 1,3-bis(4-hydroxyt-butylbenzene), 1,4-bis(4-hydroxyt-butylbenzene), 1,1,3-tris(4-hydroxyphenyl)butane, 1,1,2,2-tetra(4-hydroxyphenyl)ethane, thiobisphenol, sulfonylbisphenol, oxybisphenol, phenol novolak, orthocresol novolak, ethylphenol novolak, butylphenol novolak, octylphenol novolak, resorcinol novolak, terpene phenol; polyglycidyl ether compounds of polyhydric alcohols such as ethylene glycol, propylene glycol, butylene glycol, hexanediol, polyglycol, thiodiglycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, bisphenol A-alkylene oxide adduct; glycidyl esters of aliphatic, aromatic or alicyclic polybasic acids such as maleic acid, fumaric acid, itaconic acid, succinic acid, glutaric acid, suberic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, trimer acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, pyromellitic acid, tetrahydrophthalic acid, hexahydrophthalic acid, endomethylenetetrahydrophthalic acid; homopolymers or copolymers of glycidyl methacrylate; epoxy compounds having a glycidylamino group such as N,N-diglycidylaniline, bis(4-(N-methyl-N-glycidylamino)phenyl)methane, diglycidyl orthotoluidine;Epoxidized products of cyclic olefin compounds such as vinylcyclohexene diepoxide, dicyclopentadiene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6-methylcyclohexanecarboxylate, bis(3,4-epoxy-6-methylcyclohexylmethyl) adipate; Epoxidized conjugated diene polymers such as epoxidized polybutadiene, epoxidized styrene-butadiene copolymer; Heterocyclic compounds such as triglycidyl isocyanurate.

[0029] Examples of the isocyanate compound include aromatic diisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane-4,4'-diisocyanate, phenylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, 1,5-naphthylene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, 3,3'-dimethyldiphenyl-4,4'-diisocyanate, dianisidine diisocyanate, tetramethylxylylene diisocyanate; Alicyclic diisocyanates such as isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, trans-1,4-cyclohexyl diisocyanate, norbornene diisocyanate; Aliphatic diisocyanates such as tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4- and / or 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate; Isocyanurate trimerization products, biuret trimerization products, trimethylolpropane adducts of the exemplified diisocyanates; Triphenylmethane triisocyanate, 1-methylbenzene-2,4,6-triisocyanate, dimethyltriphenylmethane tetraisocyanate, etc. These isocyanate compounds may be used in the form of carbodiimide modification, isocyanurate modification, biuret modification, etc., or may be used in the form of blocked isocyanates blocked with various blocking agents.

[0030] In the modified amine which is the component (B-1), the usage amounts of the amine compound having one or more active hydrogens and the epoxy compound are such that the epoxy groups of the epoxy compound are 0.1 to 1.1 equivalents, particularly 0.2 to 0.9 equivalents, relative to 1 equivalent of the active hydrogen of the amine compound. It is preferably an amount. In the modified amine which is the component (B-2), the usage amounts of the amine compound having one or more active hydrogens and the isocyanate compound are such that the isocyanate groups of the isocyanate compound are 0.1 to 1.1 equivalents, particularly 0.2 to 0.9 equivalents, relative to 1 equivalent of the active hydrogen of the amine compound. It is preferably an amount. In the modified amine which is the component (B-3), the usage amounts of the amine compound having one or more active hydrogens, the epoxy compound and the isocyanate compound are such that the total amount of the epoxy groups of the epoxy compound and the isocyanate groups of the isocyanate compound is 0.1 to 1.1 equivalents, particularly 0.2 to 0.9 equivalents, relative to 1 equivalent of the active hydrogen of the amine compound. It is preferably an amount. When the amount of the epoxy compound and / or the isocyanate compound relative to the amine compound having one or more active hydrogens is less than the lower limit value, the storage stability may decrease, and when used exceeding the upper limit value, the curability may decrease. In particular, these modified amines are preferably those containing active hydrogen because they are excellent in curability and cured physical properties. That is, in the present invention, it is preferable that the (B) latent curing agent is an active hydrogen-containing amine-based latent curing agent.

[0031] The method for producing the modified amines which are the components (B-1), (B-2) and (B-3) is not particularly limited, but if necessary, using a solvent, under heating at room temperature to 140 ° C, an amine compound having one or more active hydrogens And a method of reacting an epoxy compound and / or an isocyanate compound for 1 to 10 hours can be mentioned. In the modified amine which is the component (B-3), it is preferable to react the polyisocyanate compound after reacting the amine compound and the epoxy compound. When a solvent is used in the production of the modified amine, after the reaction is completed, the solvent can also be removed by heating under normal pressure or reduced pressure. In addition, for those modified amines that are solids, those obtained by pulverizing using a pulverizer such as a jet mill can also be used.

[0032] Examples of the solvent used in the production of the modified amine include ketones such as methyl ethyl ketone, methyl amyl ketone, diethyl ketone, acetone, methyl isopropyl ketone, propylene glycol monomethyl ether acetate, and cyclohexane; ethers such as tetrahydrofuran, 1,2-dimethoxyethane, 1,2-diethoxyethane, and propylene glycol monomethyl ether; esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as benzene, toluene, and xylene; halogenated aliphatic hydrocarbons such as carbon tetrachloride, chloroform, trichloroethylene, and methylene chloride; and halogenated aromatic hydrocarbons such as chlorobenzene.

[0033] Examples of the phenolic resin used as the component (B-4) include phenolic novolak resin, cresol novolak resin, aromatic hydrocarbon formaldehyde resin-modified phenolic resin, dicyclopentadiene phenol addition type resin, phenol aralkyl resin (zylox resin), naphthol aralkyl resin, trisphenylol methane resin, tetraphenylol ethane resin, naphthol novolak resin, naphthol-phenol co-condensed novolak resin, naphthol-cresol co-condensed novolak resin, biphenyl-modified phenolic resin (a polyhydric phenol compound in which phenolic nuclei are linked by bismethylene groups), biphenyl-modified naphthol resin (a polyhydric naphthol compound in which phenolic nuclei are linked by bismethylene groups), aminotriazine-modified phenolic resin (a compound having a phenolic skeleton, a triazine ring, and a primary amino group in its molecular structure), and alkoxy group-containing aromatic ring-modified novolak resin (a polyhydric phenol compound in which a phenolic nucleus and an alkoxy group-containing aromatic ring are linked by formaldehyde), etc.

[0034] In the present invention, from the viewpoint of obtaining a balance between storage stability and curability, it is preferable to use a phenol resin having a number average molecular weight of 750 to 1200 as the phenol resin used in the component (B-4).

[0035] The amount of the phenol resin used in the (B-4) is preferably 10 to 100 parts by mass, particularly preferably 20 to 60 parts by mass, based on 100 parts by mass of the modified amine which is the component (B-1), the component (B-2), and the component (B-3). If it is less than 10 parts by mass, sufficient curability cannot be obtained, and if it exceeds 100 parts by mass, the physical properties of the cured product may deteriorate.

[0036] Among the latent curing agents, commercially available products include Adeka Hardener EH-3636AS (manufactured by ADEKA CORPORATION; dicyandiamide type latent curing agent), Adeka Hardener EH-4351S (manufactured by ADEKA CORPORATION; dicyandiamide type latent curing agent), Adeka Hardener EH-5011S (manufactured by ADEKA CORPORATION; imidazole type latent curing agent), Adeka Hardener EH-5046S (manufactured by ADEKA CORPORATION; imidazole type latent curing agent), Adeka Hardener EH-4357S (manufactured by ADEKA CORPORATION; polyamine type latent curing agent), Adeka Hardener EH-5057P (manufactured by ADEKA CORPORATION; polyamine type latent curing agent), Adeka Hardener EH-5057PK (manufactured by ADEKA CORPORATION; polyamine type latent curing agent), Amicure PN-23 (manufactured by Ajinomoto Fine-Techno Co., Inc.; amine adduct type latent curing agent), Amicure PN-40 (manufactured by Ajinomoto Fine-Techno Co., Inc.; amine adduct type latent curing agent), Amicure VDH (manufactured by Ajinomoto Fine-Techno Co., Inc.; hydrazide type latent curing agent), Fujicure FXR-1020 (manufactured by T&K TOKA CO., LTD.; latent curing agent), and the like.

[0037] The amount of the (B) latent curing agent used is not particularly limited, but it is preferably 1 to 200 parts by mass, more preferably 3 to 150 parts by mass, based on 100 parts by mass of the (A) epoxy resin. When the amount of the curing agent used is less than 1 part by mass, the curing reaction does not proceed, and when it is used in an amount exceeding 200 parts by mass, the physical properties may deteriorate.

[0038] In the present invention, a known curing accelerator can be used in combination with the (B) latent curing agent as needed. Specific examples of these curing accelerators include phosphines such as triphenylphosphine; phosphonium salts such as tetraphenylphosphonium bromide; imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-methylimidazole; imidazole salts which are salts of the above imidazoles and trimellitic acid, isocyanuric acid, boron, etc.; amines such as benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol; quaternary ammonium salts such as trimethylammonium chloride; ureas such as 3-(p-chlorophenyl)-1,1-dimethylurea, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3-phenyl-1,1-dimethylurea, isophorone diisocyanate-dimethylurea, tolylene diisocyanate-dimethylurea; and complex compounds of boron trifluoride and amines, ether compounds, etc. These curing accelerators may be used alone or in combination of two or more. The content of the curing accelerator can be set appropriately.

[0039] The (C) compound represented by the following formula (1) used in the present invention will be described.

[0040]

Chemical formula

[0041] The compound represented by the formula (1) is a urea compound and a thiourea compound having a specific structure. By adding such a compound to a curable resin composition containing a curable resin such as an epoxy resin, the curing shrinkage of the curable resin composition can be suppressed.)

[0042] In the formula (1), R 1 ~R 4 Examples of the alkyl group represented by include groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, amyl, isoamyl, sec-amyl, tert-amyl, hexyl, heptyl, octyl, isooctyl, 2-ethylhexyl, nonyl, isononyl, decyl, cyclohexyl, benzyl, phenethyl, allyl, etc., and R 1 ~R 4 Examples of the aryl group represented by include phenyl, naphthyl, anthracenyl, phenanthrenyl, etc. Further, the aryl group may be substituted with the alkyl group and aryl group exemplified above.) Also, examples of the divalent group represented by R 3 and R 4 which can form a ring structure when they are linked include groups such as methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, cyclohexylene, phenylene, naphthylene, phenanthrene, anthracenylene, etc. These may form a heterocycle containing oxygen, sulfur, nitrogen, etc., and further, a hydrogen atom in the group capable of forming a ring structure may be replaced with the alkyl group, aryl group exemplified above; halogen atoms such as fluorine, chlorine, bromine; haloalkyl groups such as fluoromethyl, chloromethyl; nitrile groups.)

[0043] As a more specific embodiment of the compound represented by the formula (1), for example, the compounds shown below can be mentioned.

[0044]

Chemical formula

[0045] Among the compounds exemplified above, the formulas U-1, U-4, U-5, U-6, U-10, U-12 and U-13 are preferable because they have an excellent effect of suppressing curing shrinkage.

[0046] The amount of the component (C) used is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the total amount of the components (A), (B) and (C). If the amount used is less than 0.1 part by mass, the effect of suppressing curing shrinkage cannot be sufficiently exhibited, and if it exceeds 10 parts by mass, it may adversely affect the physical properties of the cured product.

[0047] In the resin composition of the present invention, various additives can be contained as necessary. Examples of the additives include phenolic compounds such as biphenol; reactive diluents such as monoalkyl glycidyl ether; non-reactive diluents (plasticizers) such as dioctyl phthalate, dibutyl phthalate, benzyl alcohol, and coal tar; silica such as fused silica and crystalline silica; powders of magnesium hydroxide, aluminum hydroxide, zinc molybdate, calcium carbonate, silicon carbonate, calcium silicate, potassium titanate, beryllia, zirconia, zircon, forsterite, steatite, spinel, mullite, titania, etc., or beads obtained by spheroidizing these, and fillers such as glass fiber, pulp fiber, synthetic fiber, and ceramic fiber; reinforcing materials such as glass cloth, aramid cloth, and carbon fiber; pigments; silane coupling agents such as γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-N’-β-(aminoethyl)-γ-aminopropyltriethoxysilane, γ-anilinopropyltriethoxysilane, γ-glycidoxypropyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltriethoxysilane, vinyltriethoxysilane, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, etc.; lubricants such as candelilla wax, carnauba wax, wood wax, ivota wax, beeswax, lanolin, whale wax, montan wax, petroleum wax, aliphatic wax, aliphatic ester, aliphatic ether, aromatic ester, aromatic ether, etc.; thickeners; thixotropic agents; antioxidants; light stabilizers; ultraviolet absorbers; defoaming agents; rust preventives; and common additives such as colloidal silica and colloidal alumina. In the present invention, tacky resins such as xylene resin and petroleum resin can also be used in combination.

[0048] The curable resin composition of the present invention can be used for a wide range of applications such as paints for concrete, cement mortar, various metals, leather, glass, rubber, plastics, wood, cloth, paper, etc., or adhesives. In particular, it can be suitably used as various adhesives because of its excellent effect of suppressing curing shrinkage.

[0049] Further, the present invention provides a method for suppressing the curing shrinkage of a curable resin composition by adding (C) the compound represented by the formula (1) to a curable resin component containing (A) an epoxy resin or a cyanate ester resin (D) and (B) a latent curing agent. However, the method for producing a curable resin composition using these is not particularly limited. For example, (C) component can be added to (A) component or (B) component before mixing (A) component and (B) component.

Examples

[0050] Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In the following Examples, etc., % is based on mass unless otherwise specified.

[0051] [Production Example 1] (Synthesis of amine-based latent curing agent) A flask was charged with 230 g of Jeffamine D230 (trade name of Huntsman; polyether polyamine) and heated to 60°C. To this, 190 g of Adeka Resin EP-4901E (trade name of Adeka Corporation; bisphenol F type epoxy resin, epoxy equivalent 170) was added little by little so that the internal temperature of the system was maintained at 100 to 110°C. After adding Adeka Resin EP-4901E, the temperature was raised to 140°C and reacted for 1.5 hours to obtain a modified polyamine. To 100 g of the obtained modified polyamine, 50 g of MP-800K (manufactured by Asahi Organic Materials Co., Ltd.; phenol resin, softening point 100°C) was charged, and the solvent was removed at 180 to 190°C and 30 to 40 Torr for 1 hour, and then pulverized with a jet mill to obtain an amine-based latent curing agent (EH-1).

[0052] [Examples 1 to 6 and Comparative Example 1] EP-4100L (manufactured by ADEKA; bisphenol A type epoxy resin, component (A)), the above-mentioned EH-1 (amine-based latent curing agent, component (B)), and LECY (manufactured by Lonza; bisphenol type cyanate ester resin, component (D)) were mixed at a ratio of 1:1:1 (mass ratio) to prepare a curable resin composition containing no component (C). This was used as the curable resin composition of Comparative Example 1. To 100 parts by mass of the curable resin composition of Comparative Example 1, 3 parts by mass of component (C) shown in Table 1 below was added to obtain the curable resin compositions of Examples 1 to 6. Also, to 100 parts by mass of the curable resin composition of Comparative Example 1, 2.1 parts by mass of component (C) shown in Table 2 below was added to obtain the curable resin composition of Example 7.

[0053] (Curing shrinkage) Using a dry automatic densitometer (manufactured by Shimadzu Corporation: AccuPyc 1330), the measurement was carried out under the condition that the display temperature was 23 to 26°C. The measurement sample amount was 1 g. Calibration was performed in advance on the measurement date, the density of the standard sphere was measured, and after confirming that it was the known density ±0.002, the measurement of each sample was carried out. Twenty density data were taken, and the average value was calculated as the density. The shrinkage rate was calculated by the following formula from the density before and after curing. The curing conditions were carried out at 100°C for 1 hour. The evaluation results are shown in Table 1 and Table 2 below. Shrinkage rate % = [1 - (density after curing) / (density before curing)] × 100

[0054] [Table 1]

[0055] [Table 2]

[0056] As shown by the above examples, the curable resin composition of the present invention is excellent in suppressing curing shrinkage during curing. [Industrial Applicability]

[0057] According to the present invention, in particular, a curable resin composition with suppressed curing shrinkage can be provided, and it can be suitably used, for example, as an adhesive for precision parts.

Claims

1. A curable resin composition comprising (A) an epoxy resin, (B) a latent curing agent, and (C) at least one selected from the following formulas U-4, U-6, U-10, U-12, U-13, and U-14, wherein the content of component (C) is 0.1 to 10 parts by mass with respect to 100 parts by mass of the total amount of components (A) to (C). 【Chemical 1】

2. The curable resin composition according to claim 1, further comprising (D) a cyanate ester resin.

3. The curable resin composition according to claim 2, wherein the cyanate ester resin as component (D) comprises at least one selected from the group consisting of a compound represented by the following formula (2), a compound represented by the following formula (3), and polymers thereof. 【Chemical 2】 (wherein Y １ represents an unsubstituted or fluorine-substituted divalent hydrocarbon group, -O-, -S- or a single bond, and A １ and A ２ each independently represent a phenylene group which is unsubstituted or substituted with 1 to 4 alkyl groups.) [Chemical Formula 3] (wherein m is an integer of 1 or more, and Y ２ and Y ３ each independently represent an unsubstituted or fluorine-substituted divalent hydrocarbon group, and R ５ to R １０ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.)

4. Y1 in the formula (2) and Y in the formula (3) ２ and Y ３ The curable resin composition according to claim 3, wherein each of them is independently at least one selected from the following formulas (Y-1) to (Y-9). 【Chemical Formula 4】 (wherein n is an integer of 4 to 12, and R １１ and R １２ each independently represents a hydrogen atom or an unsubstituted or fluorine-substituted methyl group, and * represents a bond.)

5. The curable resin composition according to any one of claims 1 to 4, wherein the latent curing agent as component (B) is an active hydrogen-containing amine-based latent curing agent.

6. The curable resin composition according to claim 5, wherein the active hydrogen-containing amine-based latent curing agent comprises at least one selected from guanidine compounds.

7. The curable resin composition according to claim 5, wherein the active hydrogen-containing amine-based latent curing agent comprises at least one selected from (B-1) a modified amine obtained by reacting an amine compound having one or more active hydrogens with an epoxy compound, (B-2) a modified amine obtained by reacting an amine compound having one or more active hydrogens with an isocyanate compound, (B-3) a modified amine obtained by reacting an amine compound having one or more active hydrogens with an epoxy compound and an isocyanate compound, and (B-4) a latent curing agent containing at least one modified amine selected from (B-1), (B-2), or (B-3) and a phenol resin.

8. The curable resin composition according to any one of claims 2 to 4, wherein the content of the cyanate ester resin as component (D) is 10 to 1000 parts by mass with respect to 100 parts by mass of the epoxy resin as component (A).

9. The curable resin composition according to any one of claims 1 to 8, wherein the content of the latent curing agent as component (B) is 1 to 200 parts by mass with respect to 100 parts by mass of the epoxy resin as component (A).

10. The curable resin composition according to any one of claims 1 to 9, wherein the content of component (C) is 0.5 to 5 parts by mass with respect to 100 parts by mass of the total amount of components (A) to (C).

11. The cured product of the curable resin composition according to any one of claims 1 to 10.

12. The method for suppressing the shrinkage of a cured product produced from the curable resin composition, wherein the curing of the curable resin composition containing (A) an epoxy resin and (B) a latent curing agent is carried out by adding at least one selected from the following formulas U-4, U-6, U-10, U-12, U-13 and U-14 in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the total amount of components (A) to (C). 【Chemical Formula 5】

13. The method for suppressing the shrinkage of a cured product produced from the curable resin composition according to claim 12, wherein the curable resin composition further contains (D) a cyanate ester resin.

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