Two-pack curable resin composition and cured object formed therefrom

Abstract

A purpose of the present invention is to provide a two-pack curable resin composition capable of giving a cured object which can retain flexibility at low temperatures, is inhibited from suffering excessive resin softening at high temperatures, and has excellent creep resistance.　The two-pack curable resin composition comprises the following (A) to (D) components, wherein the amount of the (C) component is 27-80 parts by mass per 100 parts by mass of the (A) component. (A) component: an epoxy resin; (B) component: a metal catalyst; (C) component: an organic polymer having a hydrolyzable silyl group; (D) component: a hardener for epoxy resins

Description

Two-component curable resin composition and cured product thereof

[0001] The present invention relates to a two-component curable resin composition that can maintain flexibility at low temperatures and has excellent creep resistance at high temperatures.

[0002] In recent years, demand for automotive motors that drive the wheels of electric and hybrid vehicles has been expanding. Adhesives are often used to secure magnets in motors, for example, to bond the motor's stator to the magnet or the rotor to the magnet. Japanese Patent Application Laid-Open No. 8-283687 discloses that heat-curing epoxy resins are suitable as motor adhesives due to their high adhesive strength. Furthermore, in recent years, motors have been required to be more compact and have higher output, and as a result, neodymium magnets have been used as motor magnets. However, because neodymium magnets tend to expand at low temperatures and contract at high temperatures, when they are bonded with epoxy resin, the resin lacks flexibility and cannot keep up with changes in ambient temperature or motor operation, resulting in the neodymium magnets peeling off.

[0003] Therefore, a method of blending a modified silicone resin with an epoxy resin to impart flexibility is known. As one such technique, JP 2019-183090 A discloses a two-component curable resin composition containing an epoxy resin, a metal catalyst, a modified silicone polymer, and an epoxy resin curing agent.

[0004] However, the disclosed two-component curable resin composition has a problem in that, although it has good flexibility at low temperatures due to the properties of the modified silicone resin, the resin becomes too flexible at high temperatures, resulting in poor creep resistance.

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a two-component curable resin composition that can maintain flexibility at low temperatures and has excellent creep resistance at high temperatures.

[0006] The gist of the present invention is described below. In an embodiment of the present invention, the present invention overcomes the above-mentioned conventional problems. [1] A two-component curable resin composition comprising the following components (A) to (D), wherein the amount of component (C) is 27 to 80 parts by mass per 100 parts by mass of component (A): Component (A): epoxy resin; Component (B): metal catalyst; Component (C): organic polymer having a hydrolyzable silyl group; and Component (D): epoxy resin curing agent. [2] The two-component curable resin composition according to [1], which comprises component A and component B, wherein component A is a composition containing components (A) and (B), and component B is a composition containing components (C) and (D). [3] The two-component curable resin composition according to [1] or [2], wherein component (A) contains (a1) a bisphenol-type epoxy resin and / or (a2) a hydrogenated bisphenol-type epoxy resin. [4] The two-component curable resin composition according to any one of [1] to [3], wherein component (B) is a chelate-type titanium catalyst. [5] The two-component curing resin composition according to any one of [1] to [4], wherein the component (C) comprises (c1) a dimethoxysilyl-containing organic polymer and / or (c2) a trimethoxysilyl-containing organic polymer. [6] The two-component curing resin composition according to any one of [1] to [5], which is used for bonding motor magnets. [7] A cured product obtained by curing the two-component curing resin composition according to any one of [1] to [6]. [8] A motor using the two-component curing resin composition according to any one of [1] to [7].

[0007] The present invention will be described in detail below. In this specification, "X to Y" is used to mean "X or more and Y or less," with the numerical values ​​(X and Y) before and after it being included as the lower and upper limits, respectively. In addition, in this specification, the term "(meth)acrylic" means acrylic and / or methacrylic.

[0008] The present invention provides a two-component curable resin composition comprising the following components (A) to (D), in which the amount of component (C) is 27 to 80 parts by mass per 100 parts by mass of component (A): component (A): epoxy resin, component (B): metal catalyst, component (C): organic polymer having a hydrolyzable silyl group, and component (D): curing agent for epoxy resin.

[0009] The two-component curable resin composition of the present invention having such a configuration can maintain flexibility at low temperatures and has excellent creep resistance at high temperatures. [Component (A)] Component (A) of the present invention is an epoxy resin. Component (A) may be either solid or liquid, as long as it has one or more epoxy groups, and is not particularly limited. However, in terms of excellent curability at room temperature and creep resistance at high temperatures, it is preferable for the component (A) to contain an epoxy resin having two or more epoxy groups. The number of epoxy groups in the epoxy resin is preferably 6 or less, 4 or less, or 3 or less. Furthermore, in terms of workability of the two-component curable resin composition, it is preferable for the component (A) to be liquid at 25°C. Specific examples of the component (A) include bisphenol-type epoxy resins, hydrogenated epoxy resins obtained by hydrogenating epoxy resins having aromatic rings, 1,2-butanediol diglycidyl ether, 1,3-butanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, (poly)ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 2,3-butanediol diglycidyl ether, 1,5-pentanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, and the like. Examples of such epoxy resins include alkylene glycol epoxy resins such as phenol diglycidyl ether and 1,4-cyclohexanedimethanol diglycidyl ether, novolac epoxy resins such as phenol novolac epoxy resins and cresol novolac epoxy resins, glycidyl amine compounds such as N,N-diglycidyl-4-glycidyloxyaniline, 4,4'-methylenebis(N,N-diglycidylaniline), tetraglycidyldiaminodiphenylmethane, and tetraglycidyl-m-xylylenediamine, and naphthalene epoxy resins having four glycidyl groups. These may be used alone or in combination of two or more. However, from the viewpoint of excellent creep resistance at high temperatures, component (A) preferably contains (a1) bisphenol epoxy resin and / or (a2) hydrogenated epoxy resin, more preferably contains (a1) bisphenol epoxy resin and (a2) hydrogenated epoxy resin, and most preferably contains only (a1) bisphenol epoxy resin and (a2) hydrogenated epoxy resin.The silane coupling agent described below is not treated as component (A) but as an optional component.

[0010] The bisphenol epoxy resin is not particularly limited as long as it is an epoxy resin having a bisphenol skeleton, and examples thereof include bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S type, bisphenol AD ​​type epoxy resin, urethane-modified bisphenol epoxy resin, rubber-modified bisphenol epoxy resin, polyoxyalkylene-modified bisphenol epoxy resin, etc. These may be used alone or in combination of two or more, but bisphenol A epoxy resin and / or bisphenol F epoxy resin are preferred from the viewpoint of excellent creep resistance at high temperatures.

[0011] Commercially available bisphenol epoxy resins include, but are not limited to, jER828, 834, 1000, 1001, 806, and 807 (manufactured by Mitsubishi Chemical Corporation), Epicron 830, 850, 830LVP, 850CRP, 835LV, 860, and 1050 (manufactured by DIC Corporation), ADEKA RESIN EP4100, EP4400, EP4901, EP4000, and EP4000S (manufactured by ADEKA Corporation), DER-331, 332, and 334 (manufactured by The Dow Chemical Company), and YD-115, YD-127, YDF-170, and YDF-2001 (manufactured by Nippon Steel Chemical & Material Co., Ltd.). These may be used alone or in combination of two or more.

[0012] The hydrogenated epoxy resin is not particularly limited, but examples thereof include hydrogenated bisphenol type epoxy resins such as hydrogenated bisphenol A type epoxy resins, hydrogenated bisphenol F type epoxy resins, and hydrogenated bisphenol E type epoxy resins; hydrogenated cresol novolac type epoxy resins; and hydrogenated phenol novolac type epoxy resins. Among these, hydrogenated bisphenol type epoxy resins are preferred because of their excellent creep resistance at high temperatures. These may be used alone or in combination of two or more.

[0013] Commercially available hydrogenated epoxy resins include, but are not limited to, YX8000 and YX8034 (manufactured by Mitsubishi Chemical Corporation), Rikaresin HBE-100 (manufactured by New Japan Chemical Co., Ltd.), EP-4080E (manufactured by ADEKA Corporation), ST-3000 (manufactured by Nippon Steel Chemical & Material Co., Ltd.), and Denacol EX-252 (manufactured by Nagase ChemteX Corporation). These may be used alone or in combination of two or more.

[0014] It is preferable to use the bisphenol-type epoxy resin and hydrogenated epoxy resin in combination. The mass ratio of the bisphenol-type epoxy resin to the hydrogenated epoxy resin is not particularly limited, but is, for example, in the range of 20:80 to 80:20, preferably in the range of 30:70 to 70:30, and more preferably in the range of 40:60 to 60:40. By keeping the ratio within the above range, a cured product with even better creep resistance at high temperatures can be obtained. [Component (B)] The component (B) used in the present invention is a metal catalyst. There are no particular limitations on the component (B) as long as it cures the component (C), which will be described later. Specific examples of the component (B) include tin catalysts such as dibutyltin dilaurate, dibutyltin oxide, dibutyltin diacetate, dibutyltin distearate, dibutyltin laurate oxide, dibutyltin diacetylacetonate, dibutyltin dioleyl maleate, dibutyltin octoate, dioctyltin oxide, dioctyltin dilaurate, and reaction products of dioctyltin salts with silicates; titanium catalysts such as titanium tetraisopropoxide, titanium diisopropoxybis(acetylacetonate), titanium diisopropoxybis(ethylacetoacetate), tetratertiarybutyl titanate, and titanium tetra-n-butoxide; bismuth catalysts such as bismuth carboxylate, bismuth neodecanoate, bismuth subcarbonate, bismuth benzoate, bismuth abietate, bismuth neoabietate, and bismuth octoate; aluminum catalysts; zirconium catalysts; and zinc catalysts. Among these, titanium catalysts other than tin catalysts, bismuth catalysts, aluminum catalysts, zirconium catalysts, and zinc catalysts are preferred from the viewpoint of environmental friendliness, titanium catalysts are most preferred because they give cured products excellent in curability and flexibility at low temperatures, and chelate-based titanium catalysts such as titanium diisopropoxybis(acetylacetonate) and titanium diisopropoxybis(ethylacetoacetate) are more preferred. These may be used alone or in combination of two or more types.

[0015] The commercially available product of the component (B) is not particularly limited. Examples of tin catalysts include Neostan U-100, U-130, U-200, and U-303 (manufactured by Nitto Kasei Co., Ltd.); examples of titanium catalysts include TA-8, TA-10, TA-21, TA-23, TA-30, TA-80, TC-100, TC-120, and TC-401 (manufactured by Matsumoto Fine Chemical Co., Ltd.); and examples of bismuth catalysts include K-KAT348, XK-628, and XK-640 (manufactured by King Industries Co., Ltd.), Pucat B7, 25, and bismuth neodecanoate (manufactured by Nippon Chemical Industry Co., Ltd.), Borchi Examples of the zirconium catalyst include ZA-45 (manufactured by Matsumoto Fine Chemical Co., Ltd.), examples of the aluminum catalyst include DX-9740 (manufactured by Shin-Etsu Chemical Co., Ltd.), AMD, ASBD, AIPD, ALCH, ALCH-TR, Aluminum Chelate M, Aluminum Chelate D, and Aluminum Chelate A (manufactured by Kawaken Fine Chemical Co., Ltd.), and examples of the zinc catalyst include K-KAT670 (manufactured by King Industries Co., Ltd.).

[0016] The amount of the (B) component added is 0.1 to 50 parts by mass, more preferably 0.5 to 30 parts by mass, particularly preferably 1 to 15 parts by mass, and most preferably 3 to 15 parts by mass, per 100 parts by mass of the (C) component described below. An amount of 0.1 part by mass or more provides excellent curing properties at room temperature, while an amount of 50 parts by mass or less provides a cured product with excellent flexibility at low temperatures. When two or more (B) components are used, the above content refers to the total amount. [(C) Component] The (C) component used in the present invention is a hydrolyzable silyl group-containing organic polymer. The (C) component is not particularly limited as long as it is an organic polymer containing a hydrolyzable silyl group in the molecule. However, from the viewpoint of achieving both low-temperature flexibility and high-temperature creep resistance, it is preferable for the (C) component to have two or more hydrolyzable silyl groups, and an organic polymer having a terminal hydrolyzable silyl group is preferred. Examples of hydrolyzable silyl groups include alkoxysilyl groups, such as dimethoxysilyl groups, trimethoxysilyl groups, diethoxysilyl groups, and triethoxysilyl groups. From the viewpoint of excellent curing properties, dimethoxysilyl groups and / or trimethoxysilyl groups are preferred. These may be used alone or in combination of two or more. From the viewpoint of excellent curing properties, however, it is preferred that component (C) contains (c1) an organic polymer having a dimethoxysilyl group and / or (c2) an organic polymer having a trimethoxysilyl group. From the viewpoint of improving creep resistance at high temperatures, it is more preferred that component (C) contains (c1) an organic polymer having a dimethoxysilyl group and (c2) an organic polymer having a trimethoxysilyl group. Furthermore, from the viewpoint of handling, component (C) is preferably liquid at 25°C. The silane coupling agent and storage stabilizer described below are not considered as component (C), but are considered as optional components. When (c1) and (c2) are used in combination, the mass ratio of (c1) to (c2) is preferably 30:70 to 70:30, and more preferably 40:60 to 60:40.

[0017] The structure of the organic polymer of the component (C) is not particularly limited, but examples thereof include structures such as polyoxyalkylene, polyester, polycarbonate, polyurethane, polyamide, polyurea, polyimide, polyethylene, polypropylene, polyisobutylene, (meth)acrylic polymer, polystyrene, polyvinyl chloride, polybutadiene, polyisoprene, polyvinyl butyral, and polyvinyl ether. From the viewpoint of achieving both flexibility at low temperatures and creep resistance at high temperatures, the organic polymer of the component (C) preferably contains a polyoxyalkylene structure. That is, the component (C) preferably contains a hydrolyzable silyl group-containing polyoxyalkylene polymer. These may be used alone or in combination of two or more.

[0018] Commercially available products of the hydrolyzable silyl group-containing polyoxyalkylene polymer of component (C) include SAT010, SAX115, SAT030, SAT030, SAT200, SAT350, SAT400, SAX220, SAX510, SAX530, SAX575, SAX580, SAX710, SAX720, SAX725, SAX750, SAX770, S203, S303, and S203H. , S303H, S943S, S911S, MA440, MA447, MA451, MA903, MA903M, MA904, S943, MAX923, MAX951, SAX510, SAX520, SAX530, SAX580, etc. (manufactured by Kaneka Corporation), ES-S2410, ES-S2420, ES-S3430, ES-S3610, ES-S3630 (manufactured by Asahi Glass Co., Ltd.).

[0019] The amount of component (C) added is 27 to 80 parts by mass, more preferably 30 to 75 parts by mass, per 100 parts by mass of component (A). An amount of 27 parts by mass or more results in a cured product with excellent flexibility at low temperatures, while an amount of 80 parts by mass or less results in a cured product with excellent creep resistance at high temperatures. When two or more types of component (C) are used, the above content refers to their total amount. [Component (D)] Component (D) of the present invention is an epoxy resin curing agent and is not particularly limited as long as it is a compound capable of curing component (A). Examples of component (D) include amine compounds, polymercaptan compounds, and acid anhydride compounds, with amine compounds being preferred due to their excellent room-temperature curing properties. From the perspective of curability and workability after mixing, component (D) is preferably liquid at 25°C. These can be used alone or in combination. The silane coupling agents described below are not considered component (D) but are treated as optional components.

[0020] Examples of the amine compound include primary amines, secondary amines, tertiary amines, amine adduct compounds, polyamide compounds, and imidazole compounds. From the viewpoint of excellent curability at room temperature and creep resistance at high temperatures, primary amines, secondary amines, and tertiary amines are preferred, secondary amines and tertiary amines are more preferred, and tertiary amines are most preferred. These can be used alone or in combination of two or more.

[0021] Examples of the primary amine include aliphatic primary amines, alicyclic primary amines, and aromatic primary amines. The aliphatic primary amines are not particularly limited, but examples include ethylenediamine, diethylenetriamine, triethylenetetramine, and hexamethylenediamine. Examples of the alicyclic primary amines include menthenediamine, isophoronediamine, N-aminoethylpiperazine, diaminodicyclohexylmethane, and norbornanediamine. Examples of the aromatic primary amines include dimethylaminomethylphenol, metaxylylenediamine, metaphenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, and diaminodiethyldiphenylmethane.

[0022] The secondary amine or tertiary amine is not particularly limited, but examples thereof include piperidine, pyridine, benzyldimethylamine, 2-(dimethylaminomethyl)phenol, triethylenediamine, dimethylcyclohexylamine, dimethylbenzylamine, dimethylhexylamine, dimethylaminophenol, dimethylamino-p-cresol, piperidine, 1,4-diazadicyclo[2.2.2]octane, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo[5.4.0]undecene-1. As the secondary amine or tertiary amine, compounds having an aromatic ring are preferred from the viewpoint of excellent curability at room temperature and creep resistance at high temperatures, and 2,4,6-tris(dimethylaminomethyl)phenol is more preferred. Commercially available products include, for example, K-54 (Air Products Japan Co., Ltd.).

[0023] The imidazole is not particularly limited, and examples thereof include 2-methylimidazole, 1,2-dimethylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1-isobutyl-2-methylimidazole, 2-phenyl-4-methylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl- Examples include 2-undecylimidazole, 2,4-diamino-6(2'-methylimidazole(1'))ethyl-s-triazine, 2,4-diamino-6(2'-undecylimidazole(1'))ethyl-s-triazine, 2,4-diamino-6(2'-ethyl,4-methylimidazole(1'))ethyl-s-triazine, 2-phenyl-3,5-dihydroxymethylimidazole, 2-phenyl-4-hydroxymethyl-5-methylimidazole, and 1-cyanoethyl-2-phenyl-3,5-dicyanoethoxymethylimidazole.

[0024] The amine adduct compound may be one in which a tertiary amine or an imidazole compound is added to an epoxy resin and the reaction is stopped midway. In consideration of storage stability and curing properties, it is most preferable to use a fine powder obtained by pulverizing the epoxy adduct compound. Commercially available epoxy adduct compounds include the Amicure series manufactured by Ajinomoto Fine-Techno Co., Ltd., the Fujicure series manufactured by T&K Toka Corporation, and the Novacure series manufactured by Asahi Kasei Chemicals Corporation.

[0025] The polymercaptan compound is not particularly limited, and examples thereof include 3,3′-dithiodipropionic acid, trimethylolpropane tris(thioglycolate), pentaerythritol tetrakis(thioglycolate), ethylene glycol dithioglycolate, 1,4-bis(3-mercaptobutyryloxy)butane, tris[(3-mercaptopropionyloxy)-ethyl]-isocyanurate (TEMPIC), 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6(1 Examples of the alkyl polythiols include alkyl thiol such as 1,4-butanedithiol, 1,6-hexanedithiol, and 1,10-decanedithiol; and polythioethers containing terminal thiol groups.

[0026] The acid anhydride compound is not particularly limited, but examples thereof include tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl-endo-ethylenetetrahydrophthalic anhydride, trialkyltetrahydrophthalic anhydride, methylnadic anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, and maleic anhydride.

[0027] The amount of component (D) added is 0.1 to 50 parts by mass, more preferably 1 to 20 parts by mass, even more preferably 1 to 10 parts by mass, and most preferably 1 to 5 parts by mass, per 100 parts by mass of component (A). An amount of 0.1 part by mass or more provides a cured product with excellent curability at room temperature, while an amount of 50 parts by mass or less provides a cured product with excellent flexibility at low temperatures. When two or more types of component (D) are used, the above content refers to the total amount.

[0028] In the present invention, additives such as curing accelerators, fillers, various elastomers such as styrene copolymers, reactive diluents, silane coupling agents, storage stabilizers, antioxidants, light stabilizers, heavy metal deactivators, plasticizers, antifoaming agents, pigments, dyes, solvents, rust inhibitors, leveling agents, dispersants, rheology modifiers, flame retardants, and surfactants may be used as optional components within the scope of the present invention.

[0029] Fillers may be added to the present invention to improve flexibility at low temperatures and creep resistance at high temperatures. Specific examples include organic powders, inorganic powders, metallic powders, and the like. Examples of inorganic powder fillers include glass, talc, fumed silica, mica, ceramics, silicone rubber powder, calcium carbonate, carbon powder, kaolin clay, dried clay minerals, and dried diatomaceous earth. Examples of organic powder fillers include polyethylene, polypropylene, nylon, cross-linked acrylic, cross-linked polystyrene, polyester, polyvinyl alcohol, polyvinyl butyral, and polycarbonate. Examples of metallic powder fillers include gold, silver, copper, alumina, aluminum nitride, and aluminum hydroxide. The amount of filler added is not particularly limited, but is preferably 0.1 to 90% by mass, more preferably 0.5 to 85% by mass, and most preferably 1 to 80% by mass, based on the total weight of the two-component curable resin composition. When the content is 0.1% by mass or more, a cured product having excellent creep resistance at high temperatures can be obtained, and when the content is 90% by mass or less, a cured product having excellent flexibility at low temperatures can be obtained.

[0030] The fumed silica is blended for the purpose of adjusting the viscosity of the two-component curable resin composition or improving the resin strength of the cured product. Preferably, fumed silica surface-treated with dimethylsilane, trimethylsilane, alkylsilane, methacryloxysilane, organochlorosilane, polydimethylsiloxane, hexamethyldisilazane, or the like is used. Commercially available fumed silica products include, for example, Aerosil R972, R972V, R972CF, R974, R976, R976S, R9200, RX50, NAX50, NX90, RX200, RX300, R812, R812S, R8200, RY50, NY50, RY200S, RY200, RY300, R104, R106, R202, R805, R816, T805, R711, RM50, and R7200 (manufactured by Nippon Aerosil Co., Ltd.), and TS720 (manufactured by Cabonet Corporation).

[0031] Examples of the storage stabilizer include tetrafunctional alkoxysilanes such as tetramethoxysilane and tetraethoxysilane, and silicate compounds such as methyltrimethoxysilane, methyltriethoxysilane, ethyl silicate, propyl silicate, and butyl silicate. These may be used alone or in combination of two or more. The storage stabilizer is not considered to be the component (C) or the silane coupling agent described below.

[0032] Examples of silane coupling agents that can be used in the present invention include glycidyl group-containing silane coupling agents such as 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropylmethyldiethoxysilane; vinyl group-containing silane coupling agents such as vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, and vinyltrimethoxysilane; (meth)acrylic group-containing silane coupling agents such as 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, and 3-acryloxypropyltrimethoxysilane; Examples of suitable coupling agents include amino group-containing silane coupling agents such as N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, and oligomers thereof. However, glycidyl group-containing silane coupling agents and amino group-containing silane coupling agents are preferred because of their excellent creep resistance at high temperatures. It is even more preferable to use a glycidyl group-containing silane coupling agent and an amino group-containing silane coupling agent in combination, and it is most preferable to use a combination of 3-glycidoxypropyltrimethoxysilane and 3-(2-aminoethyl)aminopropyltrimethoxysilane. These may be used alone or in combination of two or more types. However, it is even more preferable to use a glycidyl group-containing silane coupling agent in combination with an amino group-containing silane coupling agent because it can further improve creep resistance at high temperatures. In addition, from the viewpoint of excellent storage stability, the two-component curable resin composition preferably contains a glycidyl group-containing silane coupling agent in a liquid different from the component (D), and preferably contains an amino group-containing silane coupling agent in a liquid different from the component (A). Furthermore, the silane coupling agent is not considered as one of the components (A) to (D).Furthermore, the silane compound contained in the storage stabilizer is not considered to be a silane coupling agent.

[0033] Commercially available silane coupling agents include, but are not limited to, KBM-1003, KBE-1003, KBM-303, KBM-403, KBE-403, KBM-502, KBE-502, KBM-503, KBE-503, KBM-5103, KBM-1403, KBM-602, KBM-603, KBM-903, KBE-903 (manufactured by Shin-Etsu Chemical Co., Ltd.), Z-6610, Z-6044, Z-6825, Z-6033, Z-6062, and Z-6094 (manufactured by Dow Corning Toray Co., Ltd.).

[0034] The content of the silane coupling agent is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and most preferably 0.5 to 5 parts by mass, per 100 parts by mass of the total amount of components (A) and (C). An amount of 0.1 part by mass or more provides a cured product with excellent creep resistance at high temperatures, while an amount of 20 parts by mass or less provides a cured product with excellent flexibility at low temperatures. When two or more silane coupling agents are used, the above content refers to the total amount.

[0035] Examples of plasticizers that can be used in the present invention include polycarboxylic acid ester-based plasticizers such as aromatic polycarboxylic acid esters, phthalic acid ester-based plasticizers such as dioctyl phthalate (DOP), dibutyl phthalate (DBP), diheptyl phthalate (DHP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), and butyl benzyl phthalate (BBP); trimellitic acid ester-based plasticizers such as trioctyl trimellitate (TOTM) and triisodecyl trimellitate (TITM); pyromellitic acid ester-based plasticizers such as tetraoctyl pyromellitate; and aliphatic polycarboxylic acid ester-based plasticizers such as di-2-ethylhexyl adipate (DOA), isodecyl adipate (DIDA), di-2-ethylhexyl sebacate (DOS), and dibutyl sebacate (DBS). Examples of suitable phosphate ester plasticizers include, but are not limited to, di-2-ethylhexyl maleate (DOM), dibutyl fumarate (DBF), di-2-ethylhexyl azelate (DOZ), di-2-ethylhexyl epoxyhexahydrophthalate, trioctyl citrate, and glycerol triacetate. Examples of suitable phosphate ester plasticizers include trimethyl phosphate, tributyl phosphate, tri-(2-ethylhexyl) phosphate, tributoxyethyl phosphate, triphenyl phosphate, tricresyl phosphate, alkylaryl phosphate, triethyl phosphate, tri(chloroethyl) phosphate, trisdichloropropyl phosphate, tris(β-chloropropyl) phosphate, octyldiphenyl phosphate, tris(isopropylphenyl) phosphate, and cresylphenyl phosphate. These may be used alone or in combination of two or more.

[0036] The two-component curable resin composition of the present invention is preferably composed of component A and component B, with component A being a composition containing component (A) and component (B), and component B being a composition containing component (C) and component (D). Separating the components into separate liquids in this manner can prevent unnecessary reactions during storage and improve storage stability. Optional components such as the silane coupling agent and filler may be contained in either component A or component B. However, the silane coupling agent is preferably contained in component A and component B in a mass ratio of 10:90 to 90:10, more preferably 20:80 to 80:20, and most preferably 20:80 to 60:40, in order to improve adhesion to the base and provide excellent creep resistance. The amount of filler contained in component A may be greater or less than the amount of filler contained in component B, or may be the same as the amount of filler contained in component B. The filler is preferably contained in component A and component B in a mass ratio of 5:95 to 95:5, more preferably 10:90 to 90:10, and most preferably 20:80 to 80:20. The two-component curable resin composition is used by mixing the two components. The mass ratio of component A to component B is preferably in the range of 95:5 to 5:95, more preferably 90:10 to 10:90, particularly preferably 80:20 to 20:80, and most preferably 80:20 to 50:50. By using the above range, a cured product with excellent creep resistance at high temperatures and flexibility at low temperatures can be obtained.

[0037] A cured product obtained by curing the two-component curable resin composition of the present invention is also an embodiment of the invention. The curing method involves mixing the two components in a predetermined ratio and then allowing the mixture to stand at 25°C for 12 to 240 hours, more preferably 72 to 240 hours, and most preferably 120 to 192 hours. The two-component curable resin composition may also be cured by heat curing. When heat curing is performed, the curing temperature is preferably 50 to 150°C, more preferably 60 to 120°C, and most preferably 70 to 100°C. The relative humidity is preferably 40% RH or higher, and the curing time is preferably 0.5 to 10 hours, more preferably 1 to 8 hours, and most preferably 3 to 6 hours.

[0038] The two-component curing resin composition of the present invention is preferably used for various applications such as adhesives, sealing agents, sealants, potting agents, coating agents, lining materials, heat dissipation materials, conductive pastes, and structural adhesive applications, and is particularly preferably used for bonding motor magnets because it can achieve both creep resistance at high temperatures and flexibility at low temperatures. Furthermore, a motor characterized by being bonded with the two-component curing resin composition of the present invention is also one embodiment of the present invention.

[0039] The two-component curing resin composition of the present invention is suitable as an adhesive. The adherend is not particularly limited, but examples include metal-to-metal, metal and magnet, metal and plastic, metal and rubber, metal and glass, plastic and rubber, plastic and glass, plastic-to-plastic, rubber-to-rubber, rubber and glass, and glass-to-glass. Among these, metal-to-metal, metal and magnet, and metal and plastic are preferred, and because the composition is excellent in bonding motor magnets, metal-to-magnet bonding is preferred.

[0040] The metal is not particularly limited, but examples include gold, silver, iron, aluminum, magnesium, copper, steel, stainless steel, and titanium. The magnet includes ferrite magnets, alloy magnets, and neodymium magnets. These magnets are suitable for bonding neodymium magnets because they combine creep resistance at high temperatures with flexibility at low temperatures. The plastic is not particularly limited, but examples include fiber-reinforced plastic (FRP), carbon fiber-reinforced plastic (CFRP), polyacrylic, polyester, polyamide, acrylonitrile-butadiene-styrene, nylon 6, polycarbonate, polyacetal, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polyphenylene ether, polyether ether ketone, polyethylene, and polypropylene. The rubber is not particularly limited, but examples include nitrile rubber, butyl rubber, urethane rubber, silicone rubber, and EPDM. Examples include bonding between two or more adherends selected from these. The surface of the material may be pre-treated or left untreated.

[0041] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. <Preparation of two-component curable resin composition> The test methods used in the examples and comparative examples are as follows. Each component was collected in the parts by mass shown in Table 1 and mixed in a mixer at room temperature for 60 minutes to prepare components A and B corresponding to two-component curable resin compositions. The detailed amounts prepared are shown in Table 1, and all values ​​are expressed in parts by mass. Component (A): Epoxy resin (a1): Bisphenol A type epoxy resin (epoxy group: difunctional, liquid at 25°C, jER828 manufactured by Mitsubishi Chemical Corporation) (a2): Hydrogenated bisphenol A type epoxy resin (epoxy group: difunctional, liquid at 25°C, Rikaresin HBE-100 manufactured by New Japan Chemical Co., Ltd.) Component (B): Metal catalyst Titanium diisopropoxybis(acetylacetonate) (TC-100 manufactured by Matsumoto Fine Chemical Co., Ltd.) Component (C): Organic polymer having hydrolyzable silyl group (c1) Polyoxyalkylene containing dimethoxysilyl groups at both ends (liquid at 25°C, SAX-750 manufactured by Kaneka Corporation) (c2) Polyoxyalkylene containing trimethoxysilyl groups at both ends (liquid at 25°C, SAX-575 manufactured by Kaneka Corporation) Component (D): Curing agent for epoxy resin 2,4,6-tris(dimethylaminomethyl)phenol (Ancamin K-54, manufactured by Air Products Japan Co., Ltd.) Optional Components: 3-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) 3-(2-aminoethyl)aminopropyltrimethoxysilane (Z-6094, manufactured by Dow-Toray Industries, Inc.) <Dynamic Viscoelasticity Measurement (DMA) (Post-Cure)> Components A and B of each two-component curable resin composition were mixed in a ratio equal to the total amount listed in Table 1 using a wooden stick under an environment of 25°C and 50% RH for 10 minutes. The mixed composition was formed into a sheet measuring 60 mm in length, 10 mm in width, and 1.0 mm in thickness, and left to stand at 25°C for 168 hours to produce a cured product. The produced cured product was attached to a jig in tension mode on a dynamic viscoelasticity measuring device DMS6100 manufactured by Hitachi High-Tech Science Corporation, and measurement was performed at a frequency of 1 Hz over a temperature range of -50 to 200°C. The "storage modulus (Pa)" was measured at a frequency of 1 Hz at -40°C and 160°C.It has excellent flexibility at low temperatures, with a storage modulus (-40°C) of 1.0 x 10. ９ In addition, in order to have excellent creep resistance at high temperatures, it is preferable that the "storage modulus (160°C)" is 2.5 × 10 ７ Pa or more, and 4.0 to 6.0 × 10 ７ Pa is even more preferable. <Test Specimen Preparation> Components A and B of each two-component curing resin composition were mixed for 10 minutes using a wooden stick in a 25°C x 50% RH environment in a ratio equal to the total amount listed in Table 1. Next, the mixed composition was applied to a 100 mm long x 25 mm wide x 1.6 mm thick SPCC-SD sheet so that the adhesive area was 1 mm long x 3.5 mm wide and the resin thickness was 0.08 mm, and another SPCC-SD sheet was bonded and fixed. After 168 hours at 25°C, the test specimen was used. <Creep Test> A 750 g weight was attached to one end of the test specimen. The specimen was then placed in a hot air drying oven set at 160°C while hanging with the opposite end facing up. After 800 hours, the test specimen was removed from the hot air drying oven and visually inspected for any peeling or detachment of the adhesive. Creep resistance was then evaluated according to the evaluation criteria. Evaluation criteria ○: Test piece did not fall off ×: Test piece fell off

[0042]

[0043] The results of Examples 1 to 6 in Table 1 confirm that the two-component curable resin composition of the present invention has excellent flexibility at low temperatures and excellent creep resistance at high temperatures. Among them, Examples 1 to 4, which used two or more types of both component (A) and component (C), had a storage modulus of 6.5 × 10 at a high temperature of 160°C. ７ Pa or less, which is a better result. In contrast, in Comparative Examples 1 and 2, the amount of component (C) exceeded 80 parts by mass relative to 100 parts by mass of component (A), and therefore it was confirmed that the storage modulus at a high temperature of 160°C was low and the creep resistance was poor. In Comparative Example 3, the amount of component (C) was less than 27 parts by mass relative to 100 parts by mass of component (A), and therefore it was confirmed that the storage modulus at a low temperature was high and the flexibility was poor.

[0044] The two-component curing resin composition of the present invention can maintain flexibility at low temperatures and has excellent creep resistance at high temperatures, and is therefore suitable for a variety of applications, such as adhesives, sealing agents, sealants, potting agents, coating agents, conductive pastes, heat dissipation agents, and flame retardants, etc. Therefore, the two-component curing resin composition of the present invention is industrially useful because it can be applied in a wide range of fields.

[0045] This application is based on Japanese Patent Application No. 2023-193440, filed on November 14, 2023, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A two-component curable resin composition comprising the following components (A) to (D), with 27 to 80 parts by mass of component (C) per 100 parts by mass of component (A): component (A): epoxy resin; component (B): metal catalyst; component (C): organic polymer having a hydrolyzable silyl group; and component (D): curing agent for epoxy resin.

2. The two-component curable resin composition according to claim 1, which consists of a component A and a component B, wherein the component A is a composition containing the components (A) and (B), and the component B is a composition containing the components (C) and (D).

3. The two-component curable resin composition according to claim 1, wherein the component (A) comprises (a1) a bisphenol type epoxy resin and / or (a2) a hydrogenated bisphenol type epoxy resin.

4. The two-component curable resin composition according to claim 1, wherein the component (B) is a chelate-type titanium catalyst.

5. The two-component curable resin composition according to claim 1, wherein the component (C) comprises (c1) a dimethoxysilyl-containing organic polymer and / or (c2) a trimethoxysilyl-containing organic polymer.

6. The two-component curable resin composition according to claim 1, which is used for bonding motor magnets.

7. A cured product obtained by curing the two-component curable resin composition according to claim 1.

8. A motor using the two-component curable resin composition according to claim 1.

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