Curable resin composition, cured product and adhesive

Abstract

A curable resin composition which contains (A) a cyanate ester resin, (B) an epoxy resin that indispensably includes at least 4-amino-3-methylphenol type epoxy resin and (C) a latent curing agent. It is preferable that the cyanate ester resin (A) is composed of one or more substances that are selected from the group consisting of compounds represented by formula (1), compounds represented by formula (2), and a polymerization product of at least one compound that is selected from among the compounds represented by formula (1) or formula (2). (1): NC-O-A1-Y1-A2-O-CN (See the description for the symbols in the formula.) (2): (See the description for the symbols in the formula.)

Description

Curable resin composition, cured product, and adhesive

[0001] The present invention relates to a curable resin composition, and more particularly to a curable resin composition containing a cyanate ester resin, a specific epoxy resin, and a latent curing agent.

[0002] Epoxy resins are widely used industrially as components or raw materials for coating materials, adhesives, and various molding materials.

[0003] Furthermore, in cases where existing epoxy resins, either used alone or in combination, are insufficient in terms of heat resistance, etc., cyanate-epoxy composite resin compositions, which are obtained by mixing epoxy resins and cyanate ester resins, have become widely used as useful materials because of their high heat resistance.

[0004] For example, a liquid epoxy resin composition for semiconductor encapsulation comprising a cyanate ester resin, an epoxy resin, an inorganic filler, a metal chelate, a dihydrazide compound, and the like has already been proposed (Patent Document 1). However, this composition requires long-term heating at high temperatures to cure, and thus does not provide satisfactory performance. Furthermore, a composite composition containing a cyanate ester resin and an epoxy resin has also been proposed using an amine-based curing agent (Patent Document 2), but this composition does not provide sufficient storage stability. Furthermore, a thermosetting resin composition using a cyanate ester resin and an epoxy resin with a latent curing agent containing an imidazole component has also been proposed (Patent Document 3). However, this composition is not satisfactory because the amount of cyanate ester resin used is limited in order to achieve sufficient storage stability. Furthermore, a composite resin composition using a cyanate ester resin and an epoxy resin in combination with a guanidine compound and a phenolic compound has also been proposed (Patent Document 4), but the heat resistance is not fully satisfactory. Furthermore, a composite resin composition has been proposed in which an amine-based latent curing agent is combined with a cyanate ester resin and an epoxy resin, each of which has a large number of functional groups (Patent Document 5). However, in this case, the storage stability is not fully satisfactory.

[0005] On the other hand, Patent Documents 6 to 8 etc. describe the 4-amino-3-methylphenol type epoxy resin used in the present invention, but do not describe the use of this in combination with a cyanate ester resin.

[0006] US Patent No. 6,469,074 JP 60-250026 A US Patent Application Publication No. 2002 / 058778 US Patent Application Publication No. 2012 / 178853 US Patent Application Publication No. 2012 / 309923 US Patent Application Publication No. 2009 / 311827 JP 2009-158712 A JP 2009-155450 A

[0007] As described above, the cyanate-epoxy composite resin compositions described in Patent Documents 1 to 5 do not provide sufficient storage stability and heat resistance. It has also been found that the use of a 4-aminophenol-type epoxy resin as the epoxy resin in a cyanate-epoxy composite resin composition results in a cured product with low viscosity and high physical properties. However, further investigations by the present inventors have revealed that there is room for improvement in terms of storage stability when a 4-aminophenol-type epoxy resin is used as the epoxy resin in a cyanate-epoxy composite resin composition. Therefore, the problem to be solved by the present invention is to provide a curable resin composition that has excellent storage stability and produces a cured product with excellent heat resistance.

[0008] Therefore, the present inventors have conducted extensive research and found that the above object can be achieved by a curable resin composition containing a cyanate ester resin, a specific epoxy resin, and a latent curing agent, thereby completing the present invention.

[0009] That is, the present invention provides a curable resin composition containing (A) a cyanate ester resin, (B) an epoxy resin essentially containing a 4-amino-3-methylphenol-type epoxy resin, and (C) a latent curing agent. The present invention also provides a cured product of the curable resin composition and an adhesive containing the curable resin composition.

[0010] The curable resin composition of the present invention will be described below based on preferred embodiments thereof.

[0011] The cyanate ester resin, which is component (A) used in the present invention, is a compound having two or more cyanate groups, and can be used without any particular restrictions on the molecular structure, molecular weight, etc.

[0012] The cyanate ester resin of component (A) can be, for example, one or more compounds selected from the group consisting of compounds represented by the following formula (1), compounds represented by the following formula (2), and at least one polymer thereof:

[0013] NC-O-A １ -Y １ -A ２ -O-CN (1) (Y in the formula １ represents a divalent hydrocarbon group that is unsubstituted or substituted with a fluorine atom or a cyanato group, or represents —O—, —S—, or a single bond; A １ and A ２ are each independently a phenylene group that is unsubstituted or substituted with 1 to 4 alkyl groups.

[0014] (wherein m is an integer of 1 or more, and Y ２ and Y ３ R each independently represents -S- or a divalent hydrocarbon group that is unsubstituted or substituted with a fluorine atom or a cyanato group. １ , R ２ , R ３ , R ４ , R ５ and R ６ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

[0015] In this specification, examples of the alkyl group having 1 to 4 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a s-butyl group, and a t-butyl group.

[0016] Y in the formula (1) １ And Y in the formula (2) ２ and Y ３The unsubstituted or fluorine atom-substituted divalent hydrocarbon group represented by the formula (1) preferably includes those having 1 to 20 carbon atoms. １ Alternatively, Y in the formula (2) ２ and Y ３ The alkyl group preferably has a structure represented by any one of the following formulas (Y-1) to (Y-9).

[0017] (where n is an integer from 4 to 12, and R ７ and R ８ are each independently a hydrogen atom or an unsubstituted or fluorine-substituted methyl group. * represents a bond.

[0018] Among the cyanate ester resins exemplified above, it is preferable to use the compound represented by formula (1) because it has a good balance between curability and post-curing properties.

[0019] Among the cyanate ester resins, bisphenol E type cyanate ester resins, biphenyl type, novolak phenol type, bisphenol A type, and other cyanate ester resins are preferred because they can provide a cured product with even more excellent heat resistance, and among these, it is preferable to use bisphenol E type cyanate ester resins. Bisphenol type cyanate ester resins such as bisphenol E type and bisphenol A type are those represented by the formula (1) where Y １ The biphenyl-type cyanate ester resin may be a resin represented by the formula (1) above, １ The novolak phenol type cyanate ester resin may be a resin in which Y ２ and Y ３ are each independently (Y-1).

[0020] When a bisphenol-type, biphenyl-type, or novolac phenol-type cyanate ester resin is used, it is preferable that the bisphenol-type, biphenyl-type, or novolac phenol-type cyanate ester resin accounts for 80 mass% or more of the total cyanate ester resin, and more preferably 90 mass% or more of the bisphenol-type, biphenyl-type, or novolac phenol-type cyanate ester resin, because this results in a cured product with even more excellent heat resistance. In particular, in the present invention, it is preferable that the bisphenol-type cyanate ester resin accounts for 80 mass% or more of the total cyanate ester resin, more preferably 90 mass% or more of the bisphenol-type cyanate ester resin, and particularly preferably 95 mass% or more of the bisphenol-type cyanate ester resin.

[0021] From the viewpoint of achieving a particularly excellent balance between curability and storage stability, the content of the cyanate ester resin is more preferably 3 parts by mass or more and 80 parts by mass or less, and particularly preferably 7 parts by mass or more and 60 parts by mass or less, per 100 parts by mass of the solid content of the composition. The solid content refers to the total amount of all components other than the solvent. The curable resin composition may or may not contain a solvent. If a solvent is contained, the content is preferably 5% by mass or less, more preferably 2% by mass or less, of the curable resin composition.

[0022] The epoxy resin (B) used in the present invention is an epoxy resin containing a 4-amino-3-methylphenol-type epoxy resin as an essential component. As a result of investigations by the present inventors, it was found that when a 4-aminophenol-type epoxy resin is used in combination with a cyanate ester resin, there is room for improvement in terms of storage stability, as shown in Comparative Example 1 below. On the other hand, although the 4-aminophenol-type epoxy resin and the 4-amino-3-methylphenol-type epoxy resin are structurally similar, combining the 4-amino-3-methylphenol-type epoxy resin with the cyanate ester resin produced a remarkable and hitherto unexpected effect of significantly improving storage stability.

[0023] The 4-amino-3-methylphenol type epoxy resin is an epoxy resin made from 4-amino-3-methylphenol as a starting material, and its production method is not particularly limited. For example, it can be produced by reacting 4-amino-3-methylphenol with epihalohydrin in the presence of an alkali.

[0024] Examples of the epihalohydrin include epichlorohydrin, epibromohydrin, β-methylepichlorohydrin, and β-methylepibromohydrin. Among these, epichlorohydrin is preferred due to its good reactivity with hydroxyl groups and amino groups. The epihalohydrins can be used alone or in combination of two or more. Examples of the alkali include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, and alkali metal carbonates such as sodium carbonate and potassium carbonate. Of these alkalis, sodium hydroxide is particularly preferred. These alkalis are preferably used as aqueous solutions, but in some cases, powdered or solid alkalis can be added simultaneously with or separately from water.

[0025] The ratio of 4-amino-3-methylphenol to epihalohydrin used is not particularly limited as long as it is at least equivalent to the hydroxyl and amino groups of the former, but is typically 1.0 to 10.0 equivalents, and preferably 2.0 to 8.0 equivalents. Here, the equivalent of 4-amino-3-methylphenol to the hydroxyl and amino groups is calculated by dividing the number of moles of epihalohydrin by "the number of moles of hydroxyl groups + (the number of moles of amino groups) × 2." If the ratio of epihalohydrin is less than 1.0 equivalent (equivalent), hydroxyl and amino groups that are not glycidyl etherified may remain, resulting in a decrease in purity. On the other hand, if the ratio exceeds 10.0 equivalents, not only will epichlorohydrin be wasted, but the reaction rate may decrease and the epoxy equivalent may increase due to side reactions. The amount of alkali used is not particularly limited as long as it is at least an equivalent (molar) to the hydroxyl groups and amino groups of the 4-amino-3-methylphenol, but is usually 1.0 to 2.0 equivalents, and preferably 1.0 to 1.5 equivalents. If the amount of alkali used is less than an equivalent to the hydroxyl groups of 4-amino-3-methylphenol, some chlorohydrin ether groups may remain unglycidyl-etherified, resulting in a decrease in purity. If the amount of alkali used exceeds 2.0 equivalents, not only will it be wasted, but side reactions may also result in a decrease in the purity of the product.

[0026] A phase transfer catalyst can also be used in the reaction, and this phase transfer catalyst is known as a reagent used to react a water-insoluble organic compound with a reagent insoluble in an organic solvent. Examples of the phase transfer catalyst include tertiary amines such as trimethylamine, trioctylamine, and tridecylamine, quaternary ammonium bases such as tetramethylammonium, methyltrioctylammonium, methyltridecylammonium, and benzyltrimethylammonium, and quaternary ammonium salts such as tetramethylammonium chloride, methyltrioctylammonium chloride, methyltridecylammonium chloride, and benzyltrimethylammonium chloride, with quaternary ammonium salts being particularly preferred.

[0027] The amount of the phase transfer catalyst used can be determined appropriately, but is usually 0.1 to 10.0 parts by mass, preferably 0.5 to 5.0 parts by mass, per 100 parts by mass of 4-amino-3-methylphenol. If the amount of the phase transfer catalyst used is less than 0.1 parts by mass, the reaction rate will be significantly slowed or side reactions will proceed, resulting in a small epoxy equivalent, making this impractical. On the other hand, if the amount exceeds 10.0 parts by mass, the phase transfer catalyst will be wasted and, in some cases, the reaction may be inhibited.

[0028] The reaction is usually carried out under heating, preferably at 30° C. to 100° C., particularly preferably at 40° C. to 80° C. In addition, a solvent inert to the reaction, such as a hydrocarbon, ether, or ketone, can be used in the reaction; however, when an excess amount of epihalohydrin is used, the epihalohydrin also functions as a solvent, and therefore, it is not essential to use a solvent inert to the reaction, as described above.

[0029] The 4-amino-3-methylphenol type epoxy resin referred to in the present invention includes a compound having the structure of the following formula (I).

[0030]

[0031] The epoxy resin of component (B) used in the present invention can be any epoxy resin other than the 4-amino-3-methylphenol type epoxy resin, and the epoxy resin has at least two epoxy groups in the molecule and can be used without any particular limitation on the molecular structure, molecular weight, etc.

[0032] Examples of the epoxy resin include polyglycidyl ether compounds of mononuclear polyhydric phenols such as hydroquinone, resorcinol, pyrocatechol, and phlorogluconol; and polynuclear polyhydric phenols such as dihydroxynaphthalene, biphenol, methylenebisphenol (bisphenol F), methylenebis(ortho-cresol), ethylidenebisphenol, isopropylidenebisphenol (bisphenol A), isopropylidenebis(ortho-cresol), tetrabromobisphenol A, 1,3-bis(4-hydroxycumylbenzene), 1,4-bis(4-hydroxycumylbenzene), 1,1,3-tris(4-hydroxyphenyl)butane, 1,1,2,2-tetra(4-hydroxyphenyl)ethane, thiobisphenol, sulfobisphenol, oxybisphenol, phenol novolac, orthocresol novolac, ethylphenol novolac, butylphenol novolac, octylphenol novolac, resorcinol novolac, and terpene phenols. polyglycidyl ether compounds of 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, and bisphenol A-alkylene oxide adducts; glycidyl ester compounds 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, and endomethylenetetrahydrophthalic acid, and 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, N,N-bis(2,3-epoxypropyl)-4-(2,3-epoxypropoxy)-2-methylaniline, N,N-bis(2,3-epoxypropyl)-4-(2,3-epoxypropoxy)aniline, and N,N,N',N'-tetra(2,3-epoxypropyl)-4,4-diaminodiphenylmethane; vinylcyclohexene diepoxide, Examples of epoxy resins include epoxidized cyclic olefin compounds such as cyclopentanediene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6-methylcyclohexanecarboxylate, and bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate; epoxidized conjugated diene polymers such as epoxidized polybutadiene and epoxidized styrene-butadiene copolymers; and heterocyclic compounds such as triglycidyl isocyanurate. These epoxy resins may be internally crosslinked with a terminal isocyanate prepolymer or may be polymerized with a polyvalent active hydrogen compound (such as a polyphenol, a polyamine, a carbonyl group-containing compound, or a polyphosphate ester). These epoxy resins may be used alone or in combination of two or more.

[0033] The epoxy resin content of the 4-amino-3-methylphenol type epoxy resin in the composition of the present invention is preferably 20 to 100% by mass, more preferably 25 to 70% by mass. When 20% by mass or more is used, a cured product having particularly excellent heat resistance can be obtained.

[0034] Furthermore, among the epoxy resins in the composition of the present invention, the epoxy resin other than the 4-amino-3-methylphenol-type epoxy resin preferably contains a glycidyl-type epoxy resin having a glycidyl group from the viewpoint of reactivity, and in particular, a glycidyl-type epoxy resin having an aromatic ring is preferred from the viewpoint of heat resistance. When the epoxy resin contains a glycidyl-type epoxy resin having an aromatic ring other than the 4-amino-3-methylphenol-type epoxy resin, the amount of the glycidyl-type epoxy resin having an aromatic ring is preferably 1% by mass to 80% by mass, and particularly preferably 15% by mass to 75% by mass, of the total epoxy resin, from the viewpoint of ensuring the amount of 4-amino-3-methylphenol-type epoxy resin and heat resistance. As the glycidyl-type epoxy resin having an aromatic ring other than the 4-amino-3-methylphenol-type epoxy resin, a polyglycidyl ether compound of a polynuclear polyhydric phenol compound is particularly preferred from the viewpoint of heat resistance. Furthermore, the use of an aliphatic epoxy resin in combination is preferred because it enables the composition to have a low viscosity. When an aliphatic epoxy resin is used in addition to a 4-amino-3-methylphenol-type epoxy resin, the amount of the 4-amino-3-methylphenol-type epoxy resin is preferably 1% by mass to 70% by mass, and particularly preferably 5% by mass to 50% by mass, of the total epoxy resin, from the viewpoints of ensuring the amount of 4-amino-3-methylphenol-type epoxy resin and reducing viscosity. An example of an aliphatic epoxy resin is a dicyclopentadiene-type epoxy resin. A dicyclopentadiene-type epoxy resin refers to a compound having a dicyclopentadiene skeleton and an epoxy group. An aliphatic compound is preferred as the dicyclopentadiene-type epoxy resin. When the epoxy resin of the present invention contains a dicyclopentadiene-type epoxy resin as the aliphatic epoxy resin, the amount of the dicyclopentadiene-type epoxy resin is preferably 1% by mass to 70% by mass, and particularly preferably 5% by mass to 50% by mass, from the same viewpoints as above.

[0035] The amount of the epoxy resin (B) used is preferably 1 to 1,000 parts by mass, more preferably 3 to 500 parts by mass, and even more preferably 5 to 200 parts by mass, relative to 100 parts by mass of the cyanate ester resin (A), since excellent physical properties of the cured product can be obtained. Furthermore, the amount of the 4-amino-3-methylphenol type epoxy resin used is preferably 1 to 200 parts by mass relative to 100 parts by mass of the cyanate ester resin (A), since use in this range is preferable since a resin composition with excellent heat resistance can be obtained, and is preferably 5 to 150 parts by mass, and even more preferably 10 to 100 parts by mass.

[0036] As the latent curing agent, which is the component (C) used in the present invention, it is preferable to use an amine-based latent curing agent having active hydrogen (hereinafter also referred to as an "active hydrogen-containing amine-based latent curing agent"), because this makes it possible to obtain a curable resin with a good balance between storage stability and curability. Examples of the active hydrogen-containing amine-based latent curing agent 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, and phthalic acid dihydrazide; guanidine compounds such as dicyandiamide, benzoguanamine, and acetoguanamine; melamine; and modified amines such as dehydration condensates of amine and carboxylic acid, adducts of amine and epoxy, adducts of amine and isocyanate, Michael adducts of amine, Mannich reaction products of amine, condensates of amine and urea, and condensates of amine and ketone.

[0037] Among the active hydrogen-containing amine-based latent curing agents, preferred examples include guanidine compounds such as dicyandiamide, benzoguanamine, and acetoguanamine; or (C-1) modified amines obtained by reacting an amine compound having one or more active hydrogens with an epoxy compound, (C-2) modified amines obtained by reacting an amine compound having one or more active hydrogens with an isocyanate compound, and (C-3) modified amines obtained by reacting an amine compound having one or more active hydrogens with an epoxy compound and an isocyanate compound, and (C-4) latent curing agents containing a phenolic resin in addition to at least one modified amine selected from (C-1), (C-2), or (C-3).

[0038] Examples of the amine compound having one or more active hydrogens include alkylenediamines such as ethylenediamine, 1,2-diaminopropane, 1,3-diaminopropane, 1,3-diaminobutane, 1,4-diaminobutane, and hexamethylenediamine; polyalkylpolyamines such as diethylenetriamine, triethylenetriamine, and tetraethylenepentamine; 1,4-diaminocyclohexane, 1,3-diaminocyclohexane, 1,3-diaminomethylcyclohexane, 1,2-diaminocyclohexane, and 1, Alicyclic polyamines such as 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, and norbornenediamine; m-xylylenediamine, diamino Aromatic polyamines such as diphenylmethane, diaminodiphenyl sulfone, diethyltoluenediamine, 1-methyl-3,5-diethyl-2,4-diaminebenzene, 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, etc.; guanamines such as benzoguanamine and acetoguanamine; 2-methylimidazole, 2 imidazoles such as 2-ethyl-4-methylimidazole, 2-isopropylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 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, and 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'-methylpiperidine, 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;Examples include 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;

[0039] Examples of the epoxy compound include polyglycidyl ether compounds of mononuclear polyhydric phenol compounds such as hydroquinone, resorcinol, pyrocatechol, and phloroglucinol; and polynuclear polyhydric phenols such as dihydroxynaphthalene, biphenol, methylenebisphenol (bisphenol F), methylenebis(ortho-cresol), ethylidenebisphenol, isopropylidenebisphenol (bisphenol A), isopropylidenebis(ortho-cresol), tetrabromobisphenol A, 1,3-bis(4-hydroxycumylbenzene), 1,4-bis(4-hydroxycumylbenzene), 1,1,3-tris(4-hydroxyphenyl)butane, 1,1,2,2-tetra(4-hydroxyphenyl)ethane, thiobisphenol, sulfonylbisphenol, oxybisphenol, phenol novolac, orthocresol novolac, ethylphenol novolac, butylphenol novolac, octylphenol novolac, resorcinol novolac, and terpene phenol. polyglycidyl ether compounds of alcohol compounds; polyglycidyl ethers of polyhydric alcohols such as ethylene glycol, propylene glycol, butylene glycol, hexanediol, polyglycol, thiodiglycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, and bisphenol A-alkylene oxide adducts; maleic acid, fumaric acid, itaconic acid, succinic acid, glutaric acid, suberic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, trimer acid, Glycidyl esters of aliphatic, aromatic, or alicyclic polybasic acids, such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, trimesic acid, pyromellitic acid, tetrahydrophthalic acid, hexahydrophthalic acid, and endomethylenetetrahydrophthalic acid, and 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, and diglycidyl orthotoluidine;Examples include epoxidized products of cyclic olefin compounds such as vinylcyclohexene diepoxide, dicyclopentanediene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl-6-methylcyclohexanecarboxylate, and bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate; epoxidized conjugated diene polymers such as epoxidized polybutadiene and epoxidized styrene-butadiene copolymers; and heterocyclic compounds such as triglycidyl isocyanurate.

[0040] The epoxy compound may be either a glycidyl type epoxy compound or a cycloalkene oxide type epoxy compound, such as an epoxidized product of a cyclic olefin compound. In the case of a glycidyl type, it may be either an aromatic epoxy compound having an aromatic ring or an aliphatic epoxy compound not having an aromatic ring. In terms of reactivity, it is preferable to use a glycidyl type epoxy compound as the epoxy compound, and in terms of heat resistance, it is more preferable to use a glycidyl type aromatic epoxy compound.

[0041] 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, and tetramethylxylylene diisocyanate; isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate; Examples of suitable isocyanate compounds include alicyclic diisocyanates such as trans-1,4-cyclohexyl diisocyanate and norbornene diisocyanate; aliphatic diisocyanates such as tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,2,4 and / or (2,4,4)-trimethylhexamethylene diisocyanate and lysine diisocyanate; isocyanurate trimerization products, biuret trimerization products, and trimethylolpropane adducts of the above-exemplified diisocyanates; triphenylmethane triisocyanate, 1-methylbenzene-2,4,6-triisocyanate, dimethyltriphenylmethane tetraisocyanate, etc. Furthermore, these isocyanate compounds may be used in a carbodiimide-modified, isocyanurate-modified, biuret-modified, or other form, or in the form of blocked isocyanates blocked with various blocking agents.

[0042] In the modified amine (C-1), the amounts of the amine compound having one or more active hydrogens and the epoxy compound used are preferably such that the epoxy group of the epoxy compound is 0.1 to 1.1 equivalents, particularly 0.2 to 1.0 equivalents, per equivalent of active hydrogen of the amine compound. In the modified amine (C-2), the amounts of the amine compound having one or more active hydrogens and the isocyanate compound used are preferably such that the isocyanate group of the isocyanate compound is 0.1 to 1.1 equivalents, particularly 0.2 to 1.0 equivalents, per equivalent of active hydrogen of the amine compound. Furthermore, in the modified amine (C-3), the amount of the amine compound having one or more active hydrogens, the epoxy compound (C-2), and the isocyanate compound (C-3) used is preferably such that the total amount of the epoxy group of the epoxy compound and the isocyanate group of the polyisocyanate compound is 0.1 to 1.1 equivalents, particularly 0.2 to 1.0 equivalents, relative to 1 equivalent of the active hydrogen of the amine compound. Here, by setting the amount of the epoxy compound and / or isocyanate compound relative to the amine compound having one or more active hydrogens to be equal to or greater than the above-mentioned lower limit, it is possible to improve the storage stability of the curable resin composition, and by setting it to be equal to or less than the above-mentioned upper limit, it is possible to reliably obtain curability, which is preferable. In particular, it is preferable to use these modified amines containing active hydrogen groups, as they have excellent curability and cured physical properties.

[0043] The method for producing the modified amines (C-1), (C-2), and (C-3) is not particularly limited, but the modified amine can be obtained by reacting the components for 1 to 10 hours under heating at room temperature to 140°C, using a solvent as needed. In the case of the modified amine (C-3), it is usually preferable to react an amine compound with an epoxy compound and then react the component with a polyisocyanate compound. When a solvent is used, the solvent can be removed after the reaction is completed by heating under normal pressure or reduced pressure.

[0044] Examples of the solvent used in producing 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.

[0045] Examples of phenolic resins used in the component (C-4) include polyhydric phenol compounds such as phenol novolak resins, cresol novolak resins, aromatic hydrocarbon formaldehyde resin-modified phenolic resins, dicyclopentadiene phenol adduct resins, phenol aralkyl resins (Xylok resins), naphthol aralkyl resins, trisphenylolmethane resins, tetraphenylolethane resins, naphthol novolak resins, naphthol-phenol co-condensed novolak resins, naphthol-cresol co-condensed novolak resins, biphenyl-modified phenolic resins (polyhydric phenol compounds in which phenol nuclei are linked via bismethylene groups), biphenyl-modified naphthol resins (polyhydric naphthol compounds in which phenol nuclei are linked via bismethylene groups), aminotriazine-modified phenolic resins (compounds having a phenol skeleton, a triazine ring, and a primary amino group in the molecular structure), and alkoxy group-containing aromatic ring-modified novolak resins (polyhydric phenol compounds in which phenol nuclei and alkoxy group-containing aromatic rings are linked via formaldehyde).

[0046] In the present invention, from the viewpoint of obtaining a curable resin composition having an excellent balance between storage stability and curability, it is preferable to use a phenolic resin (C-4) having a softening point of 50 to 200°C.

[0047] The amount of phenolic resin used to obtain the modified amine (C-4) is preferably 10 to 100 parts by mass, and particularly preferably 20 to 60 parts by mass, per 100 parts by mass of the modified amine (C-1), (C-2), and / or (C-3). An amount of 10 parts by mass or more is preferred because sufficient curability can be obtained, while an amount of 100 parts by mass or less can more reliably avoid deterioration in the physical properties of the cured product.

[0048] Among the latent curing agents, commercially available products include ADEKA HARDNER EH-3636AS (manufactured by ADEKA Corporation; dicyandiamide type latent curing agent), ADEKA HARDNER EH-4351S (manufactured by ADEKA Corporation; dicyandiamide type latent curing agent), ADEKA HARDNER EH-5011S (manufactured by ADEKA Corporation; imidazole type latent curing agent), ADEKA HARDNER EH-5046S (manufactured by ADEKA Corporation; imidazole type latent curing agent), ADEKA HARDNER EH-4357S (manufactured by ADEKA Corporation; polyamine type latent curing agent), ADEKA HARDNER EH-5057P (manufactured by ADEKA Corporation; polyamine type latent curing agent), and ADEKA HARDNER Examples include EH-5057PK (manufactured by ADEKA Corporation; polyamine-type latent curing agent), Amicure PN-23 (manufactured by Ajinomoto Fine-Techno Co., Ltd.; amine adduct-based latent curing agent), Amicure PN-40 (manufactured by Ajinomoto Fine-Techno Co., Ltd.; amine adduct-based latent curing agent), Amicure VDH (manufactured by Ajinomoto Fine-Techno Co., Ltd.; hydrazide-based latent curing agent), and Fujicure FXR-1020 (manufactured by T&K TOKA Corporation; latent curing agent).

[0049] The amount of the (C) latent curing agent used is not particularly limited, but is preferably 1 to 70 parts by mass, and more preferably 3 to 60 parts by mass, per 100 parts by mass of the total amount of the (A) cyanate ester resin and the (B) epoxy resin (the entire epoxy resin including the 4-amino-3-methylphenol type epoxy resin and other epoxy resins, if used).

[0050] In the present invention, a known curing accelerator can be used in combination with the latent curing agent (C) 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, and 1-cyanoethyl-2-methylimidazole; imidazole salts obtained by combining the above imidazoles with trimellitic acid, isocyanuric acid, boron, or the like; benzyldimethylamine, 2,4,6-tris(trimethylsilyl)-2,4,6-trimethylisothiazolinone, and the like; Examples of the curing accelerator include amines such as (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, and tolylene diisocyanate-dimethylurea; and complex compounds of boron trifluoride with amines, ether compounds, or the like. These curing accelerators may be used alone or in combination of two or more. The content of the curing accelerator in the curable resin composition of the present invention is not particularly limited and can be appropriately set depending on the application of the curable resin composition.

[0051] The resin composition of the present invention may contain various additives as needed. 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 such as magnesium hydroxide, aluminum hydroxide, zinc molybdate, calcium carbonate, silicon carbonate, calcium silicate, potassium titanate, beryllia, zirconia, zircon, fosterite, steatite, spinel, mullite, and titania, or beads obtained by spheronizing 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; γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-N' ... Examples of commonly used additives include silane coupling agents such as vinyltriethoxysilane, γ-anilinopropyltriethoxysilane, γ-glycidoxypropyltriethoxysilane, β-(3,4-epoxycyclohexyl)ethyltriethoxysilane, vinyltriethoxysilane, N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, and γ-mercaptopropyltrimethoxysilane; lubricants such as candelilla wax, carnauba wax, Japan wax, Ibota wax, beeswax, lanolin, spermaceti, montan wax, petroleum wax, aliphatic waxes, aliphatic esters, aliphatic ethers, aromatic esters, and aromatic ethers; thickeners; thixotropic agents; antioxidants; light stabilizers; ultraviolet absorbers; antifoaming agents; rust inhibitors; colloidal silica, colloidal alumina, and the like. In the present invention, adhesive resins such as xylene resins and petroleum resins can also be used in combination.

[0052] The curable resin composition of the present invention can contain a silane coupling agent. Examples of the silane coupling agent include 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, and γ-glycidoxypropyltrimethoxysilane.

[0053] The amount of the silane coupling agent is preferably, for example, 0.001 to 15 mass %, more preferably 0.01 to 10 mass %, based on the solid content of the curable resin composition (all components other than the solvent).

[0054] The curable resin composition of the present invention can contain a filler. Examples of the filler include silica such as fused silica and crystalline silica; powders such as magnesium hydroxide, aluminum hydroxide, zinc molybdate, calcium carbonate, silicon carbonate, calcium silicate, potassium titanate, beryllia, zirconia, zircon, fosterite, steatite, spinel, mullite, and titania, or spherical beads thereof, and inorganic fillers such as glass fiber, pulp fiber, synthetic fiber, and ceramic fiber; organic fillers such as acrylic resin, silicone resin, polystyrene resin, and polydivinylbenzene; rubber fillers such as acrylonitrile-butadiene rubber (NBR) and styrene-butadiene rubber (SBR); and core-shell type comb fillers having a core made of butadiene rubber or the like and a shell made of acrylic resin, epoxy resin, or the like. Examples of commercially available fillers include the Metablen (registered trademark) E series, Metablen (registered trademark) C series, and Metablen (registered trademark) W series manufactured by Mitsubishi Rayon Co., Ltd.; the MX series, SX series, and SGP series manufactured by Soken Chemical & Engineering Co., Ltd.; the Zefiac series manufactured by Aica Kogyo Co., Ltd.; the ChromoSphere-T series manufactured by Thermo Fisher Scientific; the Estapor (registered trademark) series manufactured by Merck Chimie; Finepearl (registered trademark) manufactured by Matsuura Co., Ltd.; XER-91P and XER-81P manufactured by JSR Corporation; and TMS-2670 manufactured by The Dow Chemical Company.

[0055] When the curable resin composition of the present invention contains a filler, the content thereof is preferably 20 parts by mass or more and 1,000 parts by mass or less, relative to 100 parts by mass of the total amount of the cyanate ester resin, the epoxy resin, and the latent curing agent, and more preferably 50 parts by mass or more and 500 parts by mass or less, from the viewpoint of workability when the composition is made into a one-component composition.

[0056] The curable resin composition of the present invention is characterized by excellent storage stability, a low initial viscosity, and a low viscosity increase rate. Specifically, the initial viscosity measured using an E-type viscometer (sometimes called an "E-type rotational viscometer") at 25°C at 10 rpm is preferably 70 Pa·s or less, and the viscosity increase rate after standing at 40°C for 72 hours is preferably 150% or less. The curable resin composition of the present invention preferably has a viscosity increase rate (thickening rate) of 250% or less after standing for 168 hours. The initial viscosity measured using an E-type viscometer at 25°C at 10 rpm is particularly preferably 55 Pa·s or less. From the viewpoint of ease of production of the curable resin composition, a lower limit of the initial viscosity is preferably 5 Pa·s or more. Furthermore, the lower limit of the viscosity increase rate (thickening rate) is typically 100%. The initial viscosity is preferably the viscosity measured using an E-type viscometer at 25°C for a curable resin composition that has not been left at 40°C for 0.5 hours or more after production. The viscosity is measured after the sample is kept at 25° C. and 10 rpm for 10 minutes before measurement.

[0057] In the curable resin composition of the present invention, the amount of components other than the cyanate ester resin, the epoxy resin, and the latent curing agent (excluding the filler and the solvent) may be any amount as long as it does not impair the storage stability and heat resistance, but is preferably 10 mass % or less, and more preferably 5 mass % or less, of the solid content of the composition in order to ensure sufficient amounts of the components (A) to (C).

[0058] When curing the curable resin composition of the present invention, it is preferable to heat it at, for example, 80 to 200° C., since this allows the cured product to exhibit physical properties. The curable resin composition of the present invention is useful as a one-component curable resin composition that is cured by heating.

[0059] The resin composition of the present invention can be used in a wide range of applications, such as coatings or adhesives for concrete, cement mortar, various metals, leather, glass, rubber, plastics, wood, cloth, paper, etc. In particular, because of its excellent heat resistance, it is suitably used for electronic applications such as semiconductor sealing and adhesives for electronic components, and for automotive applications.

[0060] 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, percentages are by mass unless otherwise specified.

[0061] Production Example 1 (Synthesis of Modified Polyamine) A flask was charged with 201 g (2.71 mol) of 1,2-diaminopropane and heated to 60° C., and then 580 g (3.05 equivalents as epoxy groups) of ADEKA RESIN EP-4100E (trade name of ADEKA Corporation; a bisphenol A-type epoxy resin with an epoxy equivalent of 190) was added little by little so that the temperature in the system was maintained at 100 to 110° C. After all of the ADEKA RESIN EP-4100E was added, the reaction system was heated to 140° C. and reacted for 1.5 hours to obtain a modified polyamine. Next, 30 g of MP-800K (manufactured by Asahi Organic Chemicals Co., Ltd.; phenolic resin, softening point 100°C) was added to 100 g of the obtained modified polyamine, and unreacted materials were removed by degassing under reduced pressure for 1 hour at 180 to 190°C and 30 to 40 Torr. The mixture was then pulverized using a jet mill to obtain a latent curing agent (EH-1).

[0062] [Examples 1 to 3 and Comparative Examples 1 and 2] Resin compositions were produced using the latent curing agent (component C) obtained in the above Production Examples, and commercially available products (components A) and B), and the following tests were carried out. The formulations and evaluation results are shown in Table 1 below. The formulation values ​​in Table 1 represent parts by mass.

[0063] <Initial Viscosity> The viscosity was measured at 10 rpm at 25°C using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd.; TVE-33H, cone plate radius 7.7 mm (3°)).

[0064] <Viscosity Increase Rate> An accelerated test was performed by leaving the curable resin composition in a 40°C thermostatic chamber for 72 hours and 168 hours, and the viscosity was measured under the same conditions as the initial viscosity. The viscosity increase rate was calculated from the initial viscosity: (viscosity after acceleration / initial viscosity)×100 [%]

[0065] <Glass transition temperature (Tg)> A curable resin composition was heat-cured at 125°C for 1 hour to prepare a cylindrical test piece of 4 mm diameter and 10 mm diameter, and an average linear expansion curve was prepared using a TMA device in accordance with JIS K 7197. The glass transition temperature (Tg) was measured from the branch point of the curve. Glass transition temperatures (Tg) exceeding 120°C were rated "A," and those below 120°C were rated "B."

[0066] (Note: The curable resin composition of Comparative Example 1 cured after standing at 40°C for 168 hours, and the viscosity increase rate could not be measured. The viscosity increase rate of Comparative Example 2 after 168 hours was not measured.) EP-4300E: bisphenol A type epoxy resin (manufactured by ADEKA Corporation) EP-4088S: dicyclopentadiene type epoxy resin (manufactured by ADEKA Corporation) EP-3900S: 4-amino-3-methylphenol type epoxy resin (manufactured by ADEKA Corporation) EP-3950S: ADEKA Corporation; aminophenol type epoxy resin LECy: Lonza Corporation; bisphenol type cyanate ester resin Powder filler: silica powder with an average particle size of 13.7 μm KBM-403: Shin-Etsu Silicones; silane coupling agent

[0067] As shown by the above examples, the curable resin composition containing the specific epoxy resin of the present invention has excellent storage stability and the cured product has sufficient heat resistance. In contrast, the curable resin composition containing the specific epoxy resin of the present invention exhibits thickening and is poor in storage stability, or the cured product has no heat resistance.

[0068] The curable resin composition of the present invention has particularly excellent storage stability and the heat resistance of the cured product is excellent, and therefore can be suitably used, for example, as an adhesive for electronic components.

Claims

1. A curable resin composition comprising (A) a cyanate ester resin, (B) an epoxy resin essentially containing a 4-amino-3-methylphenol type epoxy resin, and (C) a latent curing agent.

2. The curable resin composition according to claim 1, wherein the cyanate ester resin as the component (A) is at least one selected from the group consisting of a compound represented by the following formula (1), a compound represented by the following formula (2), and a polymer of at least one of these. NC—O—A １ —Y １ —A ２ —O—CN (1) (In the formula, Y １ represents an unsubstituted or fluorine atom- or cyanato group-substituted divalent hydrocarbon group, or —O—, —S—, or a single bond, and A １ and A ２ are each independently a phenylene group which is unsubstituted or substituted with 1 to 4 alkyl groups.) (In the formula, m is an integer of 1 or more, and Y ２ and Y ３ each independently represent —S—, or an unsubstituted or fluorine atom- or cyanato group-substituted divalent hydrocarbon group. R １ , R ２ , R ３ , R ４ , R ５ and R ６ are each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.) 3. Y in the formula (1) １ and Y in the formula (2) ２ and Y ３ are each independently at least one selected from the following formulas (Y-1) to (Y-9), the curable resin composition according to claim 2. (In the formula, n is an integer of 4 to 12, and R ７ and R ８ are each independently a hydrogen atom or a methyl group unsubstituted or substituted with a fluorine atom. Further, * represents a bond.) 4. The curable resin composition according to any one of claims 1 to 3, wherein the latent curing agent as component (C) is an active hydrogen-containing amine-based latent curing agent.

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

6. The curable resin composition according to any one of claims 1 to 5, wherein the amount of the 4-amino-3-methylphenol type epoxy resin is 1 to 200 parts by mass with respect to 100 parts by mass of the cyanate ester resin as component (A).

7. The curable resin composition according to any one of claims 1 to 6, wherein the viscosity measured at 25°C at 10 rpm using an E-type rotational viscometer has an initial viscosity of 70 Pa·s or less and a viscosity increase rate of 150% or less after standing at 40°C for 72 hours.

8. A cured product obtained by curing the curable resin composition according to any one of claims 1 to 7.

9. An adhesive comprising the curable resin composition according to any one of claims 1 to 7.