Epoxy resin composition

Abstract

To provide an epoxy resin composition excellent in adherence, strength and destruction state to a substrate, and excellent in low temperature curability, by reducing the density of an adhesive.SOLUTION: An epoxy resin composition comprising at least one epoxy resin, a block urethane resin, an organic compound having two or more NH2 groups or a reaction product (denatured material) of the organic compound or hydrazine, a non expansion balloon, a silane coupling agent, and a metal catalyst.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an epoxy resin composition. [Background technology]

[0002] Epoxy resin compositions have been widely used as adhesives for, for example, structural members of automobiles. For example, Patent Documents 1 and 2 describe adhesives for structural members of automobiles that contain a resin composition containing a photopolymerizable component and a rubber component or an epoxy resin, or a rubber-modified epoxy resin. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-57447 ​​A [Patent Document 2] Special Publication No. 2010-523800 [Patent Document 3] JP 2020-128466 A Summary of the Invention [Problem to be solved by the invention]

[0004] Automotive structural adhesives contain various fillers, but the use of heavy mineral or metal fillers makes the automobile body heavy, which has the problem of hindering fuel efficiency. The adhesive described in Patent Document 2 uses expandable microballoons, but the adhesiveness, strength, and breaking state to the substrate are insufficient.

[0005] In recent years, CO emissions have also increased in the automobile manufacturing process. 2With the progress of reducing emissions and saving energy, it is desired to lower the heating temperature in the manufacturing process. On the other hand, the reaction of the block urethane resin and the silane coupling agent does not proceed due to the lowering of the heating temperature, and low-temperature heated parts occur due to uneven heating, etc., which causes problems such as insufficient strength and durability, particularly in the low-temperature cured parts of the vehicle body, which are low-temperature heated parts. The adhesive described in Patent Document 3 uses a non-expandable balloon to reduce the specific gravity of the adhesive, improving the adhesion, strength, and destruction state to the substrate, but the strength and durability of the cured parts at low temperatures are insufficient.

[0006] The present invention has been made in view of such problems, and by using a non-expandable balloon, the specific gravity of the adhesive can be reduced and two or more NH 2 The present invention aims to provide an epoxy resin composition which uses an organic compound having a group and / or a reaction product (modified substance) of said organic compound or hydrazine with a metal catalyst, and which has excellent low-temperature curing properties and excellent adhesion to substrates, strength, durability and fracture state, and which is particularly suitable for use as a heat-curing one-component epoxy resin adhesive. [Means for solving the problem]

[0007] As a result of intensive research aimed at solving the above problems, the epoxy resin composition of the present invention is an epoxy resin composition having the following characteristics. (1) At least one epoxy resin, a block urethane resin, and two or more NH 2 The epoxy resin composition includes an organic compound having a group and / or a reaction product (modified substance) of the organic compound or the organic compound with hydrazine, a non-expanded balloon, a silane coupling agent, and a metal catalyst. (2) The epoxy resin composition according to (1) above, wherein the epoxy resin comprises a bisphenol A type epoxy resin. (3) The epoxy resin composition according to (1) or (2) above, wherein the epoxy resin comprises a carboxyl group-containing nitrile butadiene rubber-modified epoxy resin (NBR-modified epoxy resin). (4) Two or more of the above NH 2 The epoxy resin composition according to any one of the above (1) to (3), wherein the organic compound having a group is an organic compound having a melting point of 80 to 200°C. (5) The epoxy resin composition according to any one of (1) to (4) above, wherein the non-expanded balloons are glass balloons or resin balloons. (6) The epoxy resin composition according to any one of (1) to (5) above, wherein the silane coupling agent is a silane coupling agent having an epoxy group. (7) The epoxy resin composition according to any one of (1) to (6) above, wherein the metal catalyst is a metal catalyst containing tin, zinc, titanium, or bismuth. (8) The epoxy resin composition according to any one of (1) to (7) above, further comprising dicyandiamide. (9) The epoxy resin composition according to the above (8), further comprising a urea-based catalyst as a curing accelerator for the dicyandiamide. (10) The epoxy resin composition according to any one of (1) to (9) above, which is applied to an automobile structural member and used for the purpose of adhering the member. Effect of the Invention

[0008] It is possible to provide an epoxy resin composition which has a reduced specific gravity of an adhesive, is excellent in adhesion to a substrate, strength, durability and fracture state, and has excellent low-temperature curing properties, in particular, an epoxy resin composition which has excellent low-temperature curing properties and is preferably used for a heat-curable one-component epoxy resin adhesive. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] An embodiment of the present invention will be described below. However, the components described in the following embodiment are merely examples, and are not intended to limit the technical scope of the present invention.

[0010] The present invention is based on at least one epoxy resin or block urethane resin, and is a copolymer of two or more NH 2The epoxy resin composition (hereinafter referred to as the resin composition according to the present embodiment) contains an organic compound having a group and / or a reaction product (modified substance) of the organic compound or the organic compound with hydrazine, a non-expanded balloon, a silane coupling agent, and a metal catalyst.

[0011] Each component will be described in detail below.

[0012] <Epoxy resin> Examples of the epoxy resin, which is one of the main components in the resin composition according to the present embodiment, include bifunctional glycidyl ether type epoxy resins such as epoxy compounds having a bisphenyl group, such as bisphenol A type, bisphenol F type, brominated bisphenol A type, hydrogenated bisphenol A type, bisphenol S type, bisphenol AF type, or biphenyl type, polyalkylene glycol type or alkylene glycol type epoxy compounds, epoxy compounds having a naphthalene ring, and epoxy compounds having a fluorene group; polyfunctional glycidyl ether type epoxy resins, such as phenol novolac type, orthocresol novolac type, trishydroxyphenylmethane type, or tetraphenylolethane type; glycidyl ester type epoxy resins of synthetic fatty acids, such as dimer acid; aromatic epoxy resins having a glycidylamino group, such as N,N,N',N'-tetraglycidyldiaminodiphenylmethane (TGDDM), tetraglycidyl-m-xylylenediamine, triglycidyl-p-aminophenol, or N,N-diglycidylaniline; and epoxy compounds having a tricyclodecane ring.

[0013] The epoxy resin in the resin composition according to the present embodiment preferably contains a bisphenol A type epoxy resin and / or a carboxyl group-containing nitrile butadiene rubber modified epoxy resin (NBR modified epoxy resin). These epoxy resins are described in detail below.

[0014] <Bisphenol A type epoxy resin> The bisphenol A type epoxy resin, which is one of the main components in the resin composition according to this embodiment, will be described below.

[0015] The epoxy resin contained in the resin composition according to the present embodiment is a bisphenol A type epoxy resin having a bisphenol skeleton. By containing the bisphenol A type epoxy resin, a resin composition having sufficient strength as an adhesive can be obtained.

[0016] The bisphenol A type epoxy resin according to the present embodiment preferably has an epoxy equivalent of 150 or more and 260 or less. The amount of the bisphenol A type epoxy resin in the resin composition according to the present embodiment is preferably 20 to 80 mass %. By setting it in the above range, a resin composition having better impact resistance can be obtained.

[0017] <Carboxyl group-containing nitrile butadiene rubber modified epoxy resin (NBR modified epoxy resin)> The carboxyl group-containing nitrile butadiene rubber modified epoxy resin (NBR modified epoxy resin), which is one of the main components in the resin composition according to this embodiment, will be described below.

[0018] The resin composition according to the present embodiment contains an epoxy resin having a rubber skeleton, specifically, an NBR (nitrile butadiene rubber) modified epoxy resin containing a carboxyl group. By containing the NBR modified epoxy resin, a resin composition having excellent heat resistance, impact resistance, and flexibility can be obtained.

[0019] The NBR-modified epoxy resin according to this embodiment preferably has an epoxy equivalent of 200 or more and 500 or less. The amount of the NBR-modified epoxy resin in the resin composition according to this embodiment is preferably 5 to 70 mass %. By setting it in the above range, a resin composition having better impact resistance and flexibility can be obtained.

[0020] The epoxy resin used in producing the NBR-modified epoxy resin is not particularly limited, and any conventionally known epoxy resin can be used. The epoxy resin may be used alone or in combination of two or more kinds.

[0021] In the present invention, the epoxy equivalent and the amount added of the NBR-modified epoxy resin refer to the epoxy equivalent and the amount added of the NBR-modified epoxy resin containing an excess of the epoxy resin used during production.

[0022] <Block urethane resin> The resin composition according to this embodiment contains a blocked urethane resin in which a urethane prepolymer obtained by reacting a polyhydroxy compound with a polyisocyanate compound is blocked with an active methylene compound, an oxime compound, a phenol compound, a lactam compound, a secondary amine compound, or the like.

[0023] <Polyhydroxy compounds> The polyhydroxy compound is not particularly limited in terms of its molecular weight, skeleton, etc., so long as it is a compound having two or more hydroxyl groups, and examples thereof include relatively low molecular weight polyhydric alcohols, polyether polyols, polyester polyols, other polyols, and mixed polyols thereof.

[0024] Specific examples of polyhydric alcohols include low molecular weight polyols such as ethylene glycol (EG), diethylene glycol, propylene glycol (PG), dipropylene glycol, (1,3- or 1,4-)butanediol, pentanediol, neopentyl glycol, hexanediol, cyclohexanedimethanol, glycerin, trimethylolpropane (TMP), 1,2,5-hexanetriol, and pentaerythritol; sugars such as sorbitol; and the like.

[0025] As the polyether polyols and polyester polyols, those derived from the above-mentioned polyhydric alcohols may be used, or those derived from the aromatic diols and amines shown below may be used.

[0026] Specific examples of aromatic diols include resorcin (m-dihydroxybenzene), xylylene glycol, 1,4-benzenedimethanol, styrene glycol, and 4-(2-dihydroxyethyl)phenol; and those having a bisphenol skeleton such as a bisphenol A structure (4,4'-dihydroxyphenylpropane), a bisphenol F structure (4,4'-dihydroxyphenylmethane), a brominated bisphenol A structure, a hydrogenated bisphenol A structure, a bisphenol S structure, or a bisphenol AF structure.

[0027] Specific examples of the amines include ethylenediamine, hexamethylenediamine, etc., and specific examples of the alkanolamines include ethanolamine, propanolamine, etc.

[0028] Examples of polyether polyols include polyols obtained by adding at least one selected from the compounds exemplified as the above polyhydric alcohols, aromatic diols, and amines to at least one selected from alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide (tetramethylene oxide), and tetrahydrofuran, and styrene oxide, etc.

[0029] Specific examples of such polyether polyols include polyethylene glycol, polypropylene glycol (PPG), polypropylene triol, ethylene oxide / propylene oxide copolymer, polytetramethylene glycol (PTMG), polytetraethylene glycol, and sorbitol-based polyols.

[0030] Similarly, examples of polyester polyols include condensates of any of the above polyhydric alcohols, aromatic diols, or amines with polybasic carboxylic acids, lactone polyols, polycarbonate polyols, etc. Specific examples of the lactone polyols include those obtained by ring-opening polymerization of lactones such as ε-caprolactone, α-methyl-ε-caprolactone, or ε-methyl-ε-caprolactone with a suitable polymerization initiator, and having hydroxyl groups at both ends.

[0031] Specific examples of other polyols include acrylic polyols, polybutadiene polyols, and polymer polyols having carbon-carbon bonds in the main chain, such as hydrogenated polybutadiene polyols.

[0032] These polyhydroxy compounds may be used alone or in combination of two or more.

[0033] <Polyisocyanate compounds> The polyisocyanate compound is not particularly limited as long as it is a compound having two or more isocyanate groups, and examples thereof include aliphatic polyisocyanates, aromatic polyisocyanates, and alicyclic polyisocyanates.

[0034] Specific examples of the polyisocyanate compound include aliphatic polyisocyanates such as hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, or norbornane diisocyanate (NBDI); TDI (e.g., 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI)), MDI (e.g., 4,4'-diphenylmethane diisocyanate (4,4'-MDI), or 2,4'-diphenylmethane diisocyanate (2,4'-MDI)), 1,4-phenylene diisocyanate, aromatic polyisocyanates such as polymethylene polyphenylene polyisocyanate, xylylene diisocyanate (XDI), tetramethyl xylylene diisocyanate (TMXDI), tolidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), or triphenylmethane triisocyanate; alicyclic polyisocyanates such as transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), bis(isocyanatemethyl)cyclohexane (H6XDI), or dicyclohexylmethane diisocyanate (H12MDI); etc. These polyisocyanate compounds may be used alone or in combination of two or more.

[0035] <Blocking agent> Examples of blocking agents for block urethane include active methylene compounds such as malonic acid diesters and acetoacetates; oxime compounds such as methyl isobutyl ketone oxime and methyl ethyl ketone oxime; phenolic compounds (mono- or di-forms) such as nonylphenol and bisphenol A; lactam compounds such as ε-caprolactam; and secondary amine compounds such as dicyclohexylamine. A urethane prepolymer containing a free isocyanate group at the end is obtained by reacting this urethane prepolymer with these blocking agents to obtain a block urethane resin.

[0036] The amount of the blocking agent added is preferably 5 to 30% by mass based on the total amount of the polyhydroxy compound and the polyisocyanate compound.

[0037] <Block urethane resin synthesis catalyst> Catalysts suitable for the reaction to synthesize block urethane resins are commercially available and include, for example, metal or transition metal compounds based on aluminum, tin, zinc, titanium, manganese, bismuth or zirconium, such as dibutyltin dilaurate, zinc octoate, titanium tetrabutylate, or zirconium octoate.

[0038] The amount of the block urethane resin in the resin composition according to this embodiment is preferably 3 to 50% by mass. By setting the amount within this range, a resin composition having excellent strength and durability even at high temperatures can be obtained.

[0039] <Other ingredients> The resin composition according to the present embodiment contains two or more of the following NH 2 The composition includes an organic compound having a group and / or a reaction product (modified substance) of the organic compound or hydrazine, a non-expanding balloon, a silane coupling agent, a metal catalyst, other curing agents, other curing accelerators, and other components. Each component is described in detail below.

[0040] < 2 or more NH 2 Organic compounds with groups> Two or more NH 2Examples of the organic compound having a group include 3,3'-dichloro-4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, trimethylene-bis(4-aminobenzoate), dihydrazide of acyclic dicarboxylic acid having 10 to 12 carbon atoms, isophoronediamine, menthanediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1,2-diaminopropane, m-xylylenediamine, p-xylylenediamine, and the like. NH in the molecule of phenylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,3-diaminocyclohexane, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, ethylenediamine, bis(4-amino-3-methylcyclohexyl)methane, bis(4-aminocyclohexyl)methane, bis(4-amino-3-ethyl-5-methylphenyl)methane, 4,4'-diamino-3,3'-diethyldiphenylmethane, or polyethylenepolyamines. 2 Examples of the organic compounds include organic compounds having two or more groups. These may be used alone or in combination of two or more.

[0041] Two or more of the above NH 2 The organic compound having a group is a preferred organic compound as a curing agent for the block urethane resin, and in this embodiment, one having a melting point of 80°C to 200°C is more preferred. These two or more NH 2 The organic compound having a group is preferably 3,3'-dichloro-4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, trimethylene-bis(4-aminobenzoate), dihydrazide of a non-cyclic dicarboxylic acid having 10 to 12 carbon atoms, p-phenylenediamine, or 2,4-diaminotoluene, and more preferably 3,3'-dichloro-4,4'-diaminodiphenylmethane, trimethylene-bis(4-aminobenzoate), or dihydrazide of a non-cyclic dicarboxylic acid having 10 to 12 carbon atoms.

[0042] In this embodiment, the two or more NH 2 Organic compounds having a group or reaction products with hydrazine (modified substances) are also preferably used. 2 or more NH 2 Examples of reaction products (modified substances) of organic compounds having two or more NH groups include dihydrazides of acyclic dicarboxylic acids having 10 to 12 carbon atoms, isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, menthanediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1,2-diaminopropane, m-xylylenediamine, p-xylylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,3-diaminocyclohexane, m-phenylenediamine, and 2,5-diaminotoluene. 2 Organic compounds having a group and dibasic acids such as adipic acid; epoxy compounds having a bisphenyl group such as bisphenol A type such as 2,2-bis(4-glycidyloxyphenyl)propane, bisphenol F type, brominated bisphenol A type, hydrogenated bisphenol A type, bisphenol S type, bisphenol AF type, or biphenyl type, or their polymers (bisphenol A type epoxy resin, etc.); isophorone diisocyanate, hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate, Examples of the reaction products (modified substances) include reaction products with aliphatic or alicyclic difunctional isocyanates having no aromatic ring, such as isocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate (NBDI), transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), bis(isocyanatomethyl)cyclohexane (H6XDI), or dicyclohexylmethane diisocyanate (H12MDI), or polyisocyanates thereof. These two or more NH 2Particularly preferred examples of the reaction product (modified substance) with an organic compound having a group or with hydrazine include a reaction product (modified substance) of isophoronediamine and adipic acid, a reaction product (modified substance) of 1,3-bis(aminomethyl)cyclohexane and 2,2-bis(4-glycidyloxyphenyl)propane or a polymer (bisphenol A type epoxy resin), a reaction product (modified substance) of hydrazine and adipic acid, and a reaction product (modified substance) of ethylenediamine and isophorone diisocyanate.

[0043] <Non-inflatable balloon> The non-expandable balloon according to the present embodiment is preferably a glass balloon or a resin balloon, which is made of a relatively inelastic material such as PET, nylon, polyurethane, polyolefin, PVC, and / or other crosslinked polymers. By using a non-expandable balloon, the epoxy resin composition of the present invention can be made lighter.

[0044] <Silane coupling agent> As the silane coupling agent according to the present embodiment, one having an epoxy group is effective, and for example, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, 8-glycidoxyoctyltrimethoxysilane, or one having a plurality of epoxy groups and alkoxysilane groups in the siloxane oligomer skeleton is preferably used. These may be used alone or in combination of two or more.

[0045] <Metal catalyst> Examples of the metal catalyst according to this embodiment include tin-based catalysts such as dibutyltin diacetate, dibutyltin dilaurate, bis(acetoxydibutyltin)oxide, bis(lauroxydibutyltin)oxide, dibutyltin bisacetylacetonate, dibutyltin bismaleic acid monobutyl ester, dioctyltin bismaleic acid monobutyl ester, and dibutyltin sulfide; zinc-based catalysts such as zinc octylate, zinc bis(2-ethylhexanoate), zinc naphthenate, zinc acetate, zinc acrylate, and zinc nitrate; titanium-based catalysts such as diisopropoxytitanium bis(acetylacetonate), titanium tetra(acetylacetonate), dioctanoxytitanium dioctanate, diisopropoxytitanium bis(ethylacetoacetate), and butyl titanate; and bismuth-based catalysts such as bismuth trioclate, bismuth neodecanoate, bismuth subcarbonate, and bismuth nitrate. These may be used alone or in combination of two or more. The above metal catalysts have the effect of accelerating the curing of the block urethane resin and the silane coupling agent, and are preferable as catalysts for imparting excellent low-temperature curing properties to the epoxy resin composition.

[0046] <Other hardeners> As the other curing agent according to the present embodiment, any curing agent that is generally used as a curing agent for epoxy resins can be used as it is.

[0047] Specific examples of other curing agents include dicyandiamide, imidazole derivatives such as 2-n-heptadecylimidazole, N,N-dialkylurea derivatives, N,N-dialkylthiourea derivatives, acid anhydrides such as tetrahydrophthalic anhydride, N-aminoethylpiperazine, boron trifluoride complex compounds, and trisdimethylaminomethylphenol. These may be used alone or in combination of two or more.

[0048] Among the other curing agents, dicyandiamide can be preferably used. Dicyandiamide is a latent curing agent that can be stably stored at room temperature and has a function of being melted and activated by heating to cure rapidly. Therefore, by using dicyandiamide, a resin composition having excellent strength and durability can be obtained.

[0049] The content of the other curing agents in the resin composition according to the present embodiment is not particularly limited, and an optimal amount for each of the other curing agents can be preferably used.

[0050] <Other curing accelerators> The other curing accelerator according to the present embodiment is preferably one that has the effect of accelerating the curing reaction of dicyandiamide, which is preferably used as the other curing agent. The other curing accelerator used in the composition of the present embodiment is not particularly limited as long as it has the effect of accelerating the curing reaction of dicyandiamide, and conventionally known curing accelerators can be used. Specific examples of the other curing accelerator include aliphatic dimethylurea, aromatic dimethylurea, etc. These other curing accelerators may be used alone or in combination of two or more.

[0051] <Further other ingredients> The resin composition according to the present embodiment may further contain an inorganic filler, an organic or polymer filler, a flame retardant, an antistatic agent, an agent for imparting electrical conductivity, a lubricant, an agent for imparting sliding property, a surfactant, a colorant, or the like, depending on the application. These may be contained alone or in combination of two or more kinds. Further specific examples of other components include calcium carbonate, talc, wallestonite, fumed silica, aluminum hydroxide, calcium oxide, bentonite, kaolin, and carbon black.

[0052] <Method for producing epoxy resin composition> The method for producing the resin composition according to the present embodiment is not particularly limited, and the resin composition can be produced by a conventionally known method. For example, epoxy resins such as bisphenol A type epoxy resins and NBR modified epoxy resins, block urethane resins, and resins having two or more NH 2 The polybutene-containing polymer can be obtained by homogeneously kneading at room temperature an organic compound having a group and / or a reaction product (modified substance) of the organic compound or the reaction product with hydrazine, a non-expanded balloon, a silane coupling agent, a metal catalyst, and other components as necessary.

[0053] Example The present invention will be specifically described below with reference to examples, although the present invention is not limited thereto.

[0054] (Production of Epoxy Resin Composition of Example 1) 70 parts by weight of bisphenol A type epoxy resin (liquid, epoxy equivalent = 190), 30 parts by weight of NBR modified epoxy resin (HyPox RA 1340 manufactured by CVC), 20 parts by weight of Coronate 2532 (block urethane resin, manufactured by Tosoh Corporation), 5 parts by weight of glass balloon (non-expanded balloon: S38 manufactured by 3M), 7 parts by weight of dicyandiamide, 1 part by weight of 1-phenyl-3,3-dimethylurea, 2 parts by weight of reaction product (modified substance) of isophoronediamine and adipic acid, 0.05 parts by weight of dibutyltin diacetate, 1 part by weight of 3-glycidoxypropyltrimethoxysilane, and 30 parts by weight of a mixture of calcium carbonate, talc, wollastonite, fumed silica, and calcium oxide as a filler were mixed and degassed to obtain an epoxy resin composition.

[0055] (Production of Epoxy Resin Composition of Example 2) 70 parts by weight of bisphenol A type epoxy resin (liquid, epoxy equivalent = 190), 30 parts by weight of NBR modified epoxy resin (HyPox RA 1340 manufactured by CVC), 20 parts by weight of Coronate 2532 (block urethane resin, manufactured by Tosoh Corporation), 5 parts by weight of glass balloon (non-expanded balloon: S38 manufactured by 3M), 7 parts by weight of dicyandiamide, 1 part by weight of 1-phenyl-3,3-dimethylurea, 2 parts by weight of reaction product (modified substance) of 1,3-bis(aminomethyl)cyclohexane and bisphenol A type epoxy resin, 0.05 parts by weight of dibutyltin diacetate, 1 part by weight of 3-glycidoxypropyltrimethoxysilane, and 30 parts by weight of a mixture of calcium carbonate, talc, wollastonite, fumed silica, and calcium oxide as a filler were mixed and degassed to obtain an epoxy resin composition.

[0056] (Production of Epoxy Resin Composition of Example 3) 70 parts by weight of bisphenol A type epoxy resin (liquid, epoxy equivalent = 190), 30 parts by weight of NBR modified epoxy resin (HyPox RA 1340 manufactured by CVC), 20 parts by weight of Coronate 2532 (block urethane resin, manufactured by Tosoh Corporation), 5 parts by weight of glass balloon (non-expanded balloon: S38 manufactured by 3M), 7 parts by weight of dicyandiamide, 1 part by weight of 1-phenyl-3,3-dimethylurea, 2 parts by weight of reaction product (modified substance) of hydrazine and adipic acid, 0.05 parts by weight of dibutyltin diacetate, 1 part by weight of 3-glycidoxypropyltrimethoxysilane, and 30 parts by weight of a mixture of calcium carbonate, talc, wollastonite, fumed silica, and calcium oxide as a filler were mixed and degassed to obtain an epoxy resin composition.

[0057] (Production of Epoxy Resin Composition of Example 4) An epoxy resin composition was obtained by mixing 70 parts by weight of bisphenol A type epoxy resin (liquid, epoxy equivalent = 190), 30 parts by weight of NBR modified epoxy resin (HyPox RA 1340 manufactured by CVC), 20 parts by weight of Coronate 2532 (block urethane resin, manufactured by Tosoh Corporation), 5 parts by weight of glass balloon (non-expanded balloon: S38 manufactured by 3M), 7 parts by weight of dicyandiamide, 1 part by weight of 1-phenyl-3,3-dimethylurea, 2 parts by weight of a reaction product (modified substance) of isophoronediamine and adipic acid, 0.05 parts by weight of diisopropoxytitanium bis(acetylacetonate), 1 part by weight of 3-glycidoxypropyltrimethoxysilane, and 30 parts by weight of a mixture of calcium carbonate, talc, wollastonite, fumed silica, and calcium oxide as a filler, and degassing the mixture.

[0058] (Production of Epoxy Resin Composition of Example 5) 70 parts by weight of bisphenol A type epoxy resin (liquid, epoxy equivalent = 190), 30 parts by weight of NBR modified epoxy resin (HyPox RA 1340 manufactured by CVC), 20 parts by weight of Coronate 2532 (block urethane resin, manufactured by Tosoh Corporation), 5 parts by weight of glass balloon (non-expanded balloon: S38 manufactured by 3M), 7 parts by weight of dicyandiamide, 1 part by weight of 1-phenyl-3,3-dimethylurea, 2 parts by weight of a reaction product (modified substance) of isophoronediamine and adipic acid, 0.05 parts by weight of zinc octylate, 1 part by weight of 3-glycidoxypropyltrimethoxysilane, and 30 parts by weight of a mixture of calcium carbonate, talc, wollastonite, fumed silica, and calcium oxide as a filler were mixed and degassed to obtain an epoxy resin composition.

[0059] (Production of Epoxy Resin Composition of Example 6) An epoxy resin composition was obtained by mixing 70 parts by weight of bisphenol A type epoxy resin (liquid, epoxy equivalent = 190), 30 parts by weight of NBR modified epoxy resin (HyPox RA 1340 manufactured by CVC), 20 parts by weight of Coronate 2532 (block urethane resin, manufactured by Tosoh Corporation), 5 parts by weight of glass balloon (non-expanded balloon: S38 manufactured by 3M), 7 parts by weight of dicyandiamide, 1 part by weight of 1-phenyl-3,3-dimethylurea, 2 parts by weight of a reaction product (modified substance) of isophoronediamine and adipic acid, 0.05 parts by weight of bismuth trioclate, 1 part by weight of 3-glycidoxypropyltrimethoxysilane, and 30 parts by weight of a mixture of calcium carbonate, talc, wollastonite, fumed silica, and calcium oxide as a filler, and degassing the mixture.

[0060] (Production of Epoxy Resin Composition of Comparative Example 1) An epoxy resin composition was obtained by mixing 70 parts by weight of bisphenol A type epoxy resin (liquid, epoxy equivalent=190), 30 parts by weight of NBR modified epoxy resin (HyPox RA 1340 manufactured by CVC), 20 parts by weight of Coronate 2532 (block urethane resin manufactured by Tosoh Corporation), 5 parts by weight of glass balloon (non-expanded balloon: S38 manufactured by 3M), 7 parts by weight of dicyandiamide, 1 part by weight of 1-phenyl-3,3-dimethylurea, 1 part by weight of 3-glycidoxypropyltrimethoxysilane, and 30 parts by weight of a mixture of calcium carbonate, talc, wollastonite, fumed silica, and calcium oxide as a filler, and degassing the mixture.

[0061] (Production of Epoxy Resin Composition of Comparative Example 2) An epoxy resin composition was obtained by mixing 70 parts by weight of bisphenol A type epoxy resin (liquid, epoxy equivalent = 190), 30 parts by weight of NBR modified epoxy resin (HyPox RA 1340 manufactured by CVC), 20 parts by weight of Coronate 2532 (block urethane resin, manufactured by Tosoh Corporation), 5 parts by weight of glass balloon (non-expanded balloon: S38 manufactured by 3M), 7 parts by weight of dicyandiamide, 1 part by weight of 1-phenyl-3,3-dimethylurea, 2 parts by weight of a reaction product (modified substance) of isophoronediamine and adipic acid, 1 part by weight of 3-glycidoxypropyltrimethoxysilane, and 30 parts by weight of a mixture of calcium carbonate, talc, wollastonite, fumed silica, and calcium oxide as a filler, and degassing the mixture.

[0062] (Production of Epoxy Resin Composition of Comparative Example 3) 70 parts by weight of bisphenol A type epoxy resin (liquid, epoxy equivalent = 190), 30 parts by weight of NBR modified epoxy resin (HyPox RA 1340 manufactured by CVC), 20 parts by weight of Coronate 2532 (block urethane resin, manufactured by Tosoh Corporation), 5 parts by weight of glass balloon (non-expanded balloon: S38 manufactured by 3M), 7 parts by weight of dicyandiamide, 1 part by weight of 1-phenyl-3,3-dimethylurea, 0.05 parts by weight of dibutyltin diacetate, 1 part by weight of 3-glycidoxypropyltrimethoxysilane, and 30 parts by weight of a mixture of calcium carbonate, talc, wollastonite, fumed silica, and calcium oxide as a filler were mixed and degassed to obtain an epoxy resin composition.

[0063] (Testing and Evaluation Methods) (1) Tensile shear strength test (1-1) The compositions obtained in each of the Examples and Comparative Examples were applied to the surface of mild steel plates and cured at a prescribed temperature (145°C) for a prescribed time (30 minutes) to prepare samples immediately after curing, which were then subjected to a tensile shear strength test. After curing, the specimens were left for 30 days in a high-temperature constant-humidity chamber set at 30° C. and 90% humidity, and then subjected to a tensile shear strength test. (1-2) The test was carried out under the following conditions. Test method: Compliant with JIS K 6850 Test speed: 50mm / min Coating thickness: 0.2mm Coating area: 13×25mm Test temperature: 23℃ It was decided. (1-3) The decrease in tensile shear strength after leaving the specimen for 30 days under conditions of 30°C and 90% humidity was calculated as the strength decrease rate (%) from the "tensile shear strength of the specimen immediately after curing" and the "tensile shear strength of the specimen after leaving it" using the following formula. Strength reduction rate (%) = ["tensile shear strength of sample immediately after curing" - "tensile shear strength of sample after standing" / "tensile shear strength of sample immediately after curing"] x 100 (2) Destruction state The fracture state (morphology) of the sample surface after the tensile shear strength test was visually observed. The fracture state (morphology) was evaluated for the degree to which it showed "cohesive failure", and was expressed as the degree (%) of "cohesive failure" on the entire sample surface (see Patent No. 6049705).

[0064] The evaluation results of Examples 1 to 6 and Comparative Examples 1 to 3 are shown in Table 1.

[0065] [Table 1]

[0066] In Examples 1 to 6, the tensile shear strength and breaking state of the "samples immediately after curing" showed good results, even though the curing temperature was low, at 145° C. On the other hand, in Comparative Examples 1 to 3, the strength was lower than in Examples 1 to 6. In addition, in Examples 1 to 6, even after being left under high humidity conditions, the strength reduction rate (%) was less than 20%, which was a good result, whereas in Comparative Examples 1 to 3, the strength reduction rate (%) was 30% or more, and Comparative Example 1 in particular showed a large strength reduction of 50%. In Examples 1 to 6, 100% of the samples showed "cohesive failure" even after being left under high humidity conditions, whereas in Comparative Examples 1 to 3, 30% to 70% of the samples showed "cohesive failure." Therefore, it was found that the epoxy resin compositions in the examples had excellent strength and durability.

Claims

1. At least one epoxy resin, a blocked urethane resin, and two or more NH groups selected from 3,3'-dichloro-4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, trimethylene-bis(4-aminobenzoate), isophoronediamine, menthanediamine, 2,2,4-trimethylhexamethylenediamine, 2,4,4-trimethylhexamethylenediamine, 1,2-diaminopropane, m-xylylenediamine, p-xylylenediamine, 1,3-bis(aminomethyl)cyclohexane, 1,3-diaminocyclohexane, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, ethylenediamine, bis(4-amino-3-methylcyclohexyl)methane, bis(4-aminocyclohexyl)methane, bis(4-amino-3-ethyl-5-methylphenyl)methane, 4,4'-diamino-3,3'-diethyldiphenylmethane, and polyethylene polyamines, and / or a reaction product (modified substance) with the organic compound, a glass balloon or a resin balloon, a silane coupling agent, and a metal catalyst, and further, an epoxy resin composition containing dicyandiamide. ２ groups, and a glass balloon or a resin balloon, a silane coupling agent, and a metal catalyst, and further, an epoxy resin composition containing dicyandiamide.

2. The epoxy resin composition according to claim 1, wherein the epoxy resin contains a bisphenol A type epoxy resin.

3. The epoxy resin composition according to claim 1 or 2, wherein the epoxy resin contains a carboxyl group-containing nitrile butadiene rubber-modified epoxy resin (NBR-modified epoxy resin).

4. The above two or more NH ２ The epoxy resin composition according to any one of claims 1 to 3, wherein the organic compound having a group is an organic compound having a melting point of 80 to 200°C.

5. The epoxy resin composition according to any one of claims 1 to 4, wherein the silane coupling agent is a silane coupling agent having an epoxy group.

6. The epoxy resin composition according to any one of claims 1 to 5, wherein the metal catalyst is a metal catalyst containing tin, zinc, titanium, or bismuth.

7. The epoxy resin composition according to any one of claims 1 to 6, wherein the epoxy resin composition further contains a urea-based catalyst as a curing accelerator for the dicyandiamide.

8. The epoxy resin composition according to any one of claims 1 to 7, which is applied to an automotive structural member and used for the purpose of bonding the members.

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