Curable resin composition

Abstract

To provide a curable resin composition that exhibits superior workability, allows room-temperature curing, prevents foaming (bubble formation) even after a heating process, and yields a cured product combining high adhesive strength with stable bonding performance.SOLUTION: A curable resin composition comprising the following components (A) to (D): Component (A): a compound having two or more epoxy groups; Component (B): a thiol curing agent; Component (C): a curing accelerator; Component (D): a compound having at least one (meth)acryloyl group and at least one phosphate group in a single molecule.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a curable resin composition that has stable adhesive properties and can suppress foaming from occurring inside the adhesive when used in the automobile manufacturing process. [Background technology]

[0002] Heat-curing synthetic rubber mastic adhesives have traditionally been used for outer and inner panels such as the roofs and doors of automobiles (Patent Document 1). Conventional heat-curing synthetic rubber mastic adhesives are cured by heating during the automobile painting process. Furthermore, the adhesive must have stable adhesive performance after curing. An indicator of stable adhesive performance is that when an external force is applied after adhesion to cause failure, if the failure state is interfacial failure, where the failure occurs at the interface between the adherend and the adhesive or sealant, this is considered undesirable because variations in the interfacial state result in large variations in adhesive strength. On the other hand, if the failure state is cohesive failure, where the failure occurs within the adhesive or sealant, then stable adhesive performance is considered to be achieved. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2011-162573 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional heat-curing synthetic rubber adhesives have the problem that bubbles form inside the adhesive during heating processes such as painting, causing it to lose its adhesive properties. [Means for solving the problem]

[0005] As a result of intensive research to solve the above problems, the present inventors have discovered a curable resin composition that has stable adhesive performance as an adhesive or sealant and does not generate bubbles (foaming) even during a heating process.

[0006] The gist of the present invention will now be described. [1] A curable resin composition comprising the following components (A) to (D): Component (A): a compound having two or more epoxy groups (B) Component: Thiol curing agent Component (C): Curing accelerator Component (D): A compound having one or more (meth)acryloyl groups and one or more phosphate groups per molecule.

[0007] [2] The curable resin composition according to [1], wherein the first liquid contains the components (A) and (D), and the second liquid contains the components (B) and (C).

[0008] [3] The curable resin composition according to [1] or [2], which does not contain a compound having a (meth)acryloyl group in one molecule (excluding component (D)).

[0009] [4] The curable resin composition according to [1] or [2], wherein the component (B) is (B-1) a thiol curing agent having no disulfide bond in the main chain and a polyether skeleton and / or (B-2) a thiol curing agent having a disulfide bond and a polyether skeleton in the main chain.

[0010] [5] The curable resin composition according to [1] or [2], wherein the component (C) is liquid at 25°C.

[0011] [6] The curable resin composition according to [2], further comprising a plasticizer in the first liquid and / or the second liquid as component (E).

[0012] [7] The curable resin composition according to [2], further comprising an inorganic filler in the first liquid and / or the second liquid as component (F).

[0013] [8] The curable resin composition according to [1] or [2], which does not contain a silane coupling agent.

[0014] [9] The curable resin composition according to [7], wherein the component (F) is colloidal calcium carbonate powder.

[0015]

[10] A cured product obtained by curing the curable resin composition according to [1] or [2]. [Effects of the Invention]

[0016] The cured resin composition of the present invention can achieve high adhesive strength and a high rate of cohesive failure, and further, does not foam during the heating process, and has stable performance as an adhesive or sealant. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described in detail below. In this specification, "X to Y" is used to mean that the numerical values ​​(X and Y) before and after it are included as the lower limit and upper limit, and means "at least X and at most Y."

[0018] The component (A) used in the present invention is not particularly limited as long as it is a compound having two or more epoxy groups per molecule. Component (A) is not particularly limited, but examples include, but are not limited to, bisphenol A epoxy resins, bisphenol F epoxy resins, bisphenol S epoxy resins, bisphenol AD ​​epoxy resins, naphthalene epoxy resins, biphenyl epoxy resins, phenol novolac epoxy resins, brominated bisphenol A epoxy resins, hydrogenated bisphenol A epoxy resins, glycidylamine epoxy resins, dicyclopentadiene epoxy resins, orthocresol novolac epoxy resins, and alicyclic epoxy resins. Among the components (A), from the viewpoint of improving adhesive strength and cohesive failure rate by mixing with component (B), it is preferable to include a bisphenol epoxy resin and / or a hydrogenated epoxy resin, more preferably a bisphenol epoxy resin, and most preferably a bisphenol A epoxy resin alone. These may be used alone or in combination.

[0019] From the viewpoint of curability, the epoxy equivalent of the component (A) is preferably 50 g / eq or more and less than 400 g / eq, more preferably 100 g / eq or more and less than 300 g / eq. From the viewpoint of workability, the viscosity of the component (A) at 25°C is preferably 0.1 Pa·s to 300 Pa·s, more preferably 0.1 Pa·s to 100 Pa·s, and most preferably 0.1 Pa·s to 10 Pa·s.

[0020] Commercially available products of the component (A) include jER828, 1001, 806, 807, 152, 604, 630, 871, YX8000, YX8034, and YX4000 (manufactured by Mitsubishi Chemical Corporation), Epicron 830, EXA-830LVP, EXA-850CRP, EXA-835LV, HP4032D, HP4700, and HP820 (manufactured by DIC Corporation), EP-4100, EP-4100G, EP-4100E, and EP-4100TX. , EP-4300E, EP-4000, EP-4000G, EP-4000E, EP-4000TX, EP-4005, EP-4400, EP-4520S, EP-4530, EP-4901, EP-4901EP- 4080, EP-4085, EP-4088, EP-5100-75X, EP-7001, EP-4080E, EPU-6, EPU-7N, EPU-11F, EPU-15F, EPU-1395, EPU-73B, EP U-17, EPU-17, EPU-17T-6, EPU-80, EPR-1415-1, EPR-2000, EPR-2007, EPR-1630, EP-49-10N, EP-49-10P2, EPR4023, EPR2007 (ADEKA Corporation), Denacol EX-211, EX-212, EX-252, EX-810, EX-811, EX-850, EX-851, EX-821, EX-830, EX-8 Examples of suitable acrylic resins include, but are not limited to, 32, EX-841, EX-861, EX-920, and EX-931 (manufactured by Nagase ChemteX Corporation), TEPIC, TEPIC-S, and TEPIC-VL (manufactured by Nissan Chemical Industries, Ltd.), SY-35M, SR-NPG, and SR-TMP (manufactured by Sakamoto Pharmaceutical Co., Ltd.), and Likaresin HBE-100, DME-100, L-200, BPO-20E, and BPO-60E (manufactured by New Japan Chemical Co., Ltd.). These resins may be used alone or in combination of two or more.

[0021] The component (B) of the present invention is a thiol curing agent. There are no particular limitations on the thiol curing agent as long as it has a thiol group (SH group), but compounds having two or more thiol groups are preferred from the viewpoint of improving adhesive strength and cohesive failure rate. Specific examples include trimethylolpropane tris(3-mercaptopropionate), tris-[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, pentaerythritol tetrakis(3-mercaptopropionate), tetraethylene glycol bis(3-mercaptopropionate), dipentaerythritol hexakis(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), 1,4-bis(3-mercaptobutyryl) Examples of suitable mercaptobutyryloxyethyl (mercaptobutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione include, but are not limited to, trimethylolpropane tris(3-mercaptobutyrate), trimethylolethane tris(3-mercaptobutyrate), trimethylolpropane tris(3-mercaptobutyrate), trimethylolethane tris(3-mercaptobutyrate), and polysulfide polymers. These may be used alone or in combination of two or more. Among the (B) components, from the viewpoint of improving adhesive strength and cohesive failure rate, it is more preferable to include (B-1) a thiol curing agent having a polyether skeleton and no disulfide bonds in the main chain and / or (B-2) a thiol curing agent having a disulfide bond and a polyether skeleton in the main chain, more preferable to include a polymer having a polyether skeleton and no disulfide bonds in the main chain and three or more thiol groups in one molecule and / or a polymer having a disulfide bond and a polyether skeleton in the main chain and thiol groups at the terminals, and it is most preferable to include both a polymer having a polyether skeleton and no disulfide bonds in the main chain and three or more thiol groups in one molecule and a polymer having a disulfide bond and a polyether skeleton in the main chain and thiol groups at the terminals.

[0022] Commercially available products of component (B) include, but are not limited to, TMMP, TEMPIC, PEMP, EGMP-4, and DPMP (manufactured by SC Organic Chemicals Co., Ltd.), Karenz MTPE1, BD1, NR1, and TPMB (manufactured by Showa Denko K.K.), Thiokol LP, Frep, and Polythiol QE-340M (manufactured by Toray Fine Chemicals Co., Ltd.).

[0023] When the (B) component contains a polymer having a disulfide bond and a polyether skeleton in its main chain and a terminal thiol group, the average molecular weight is preferably 500 to 4,000, more preferably 600 to 3,000, and most preferably 800 to 2,000, from the viewpoint of improving adhesive strength and cohesive failure rate. When the (B) component contains both a thiol curing agent (B-1) having a polyether skeleton but no disulfide bond in its main chain and a thiol curing agent (B-2) having a disulfide bond and a polyether skeleton in its main chain, the ratio of (B-1):(B-2) is preferably 5:95 to 50:50, more preferably 20:80 to 40:60, and most preferably 3:97 to 30:70. By having the (B-1):(B-2) ratio be 5:95 to 50:50, a curable resin composition with excellent adhesive strength and cohesive failure rate can be realized.

[0024] The (B) component is preferably contained in an amount of 50 to 350 parts by mass, more preferably 70 to 300 parts by mass, and most preferably 100 to 280 parts by mass per 100 parts by mass of the (A) component. If the amount is 50 parts by mass or more, the cured product will be flexible and will be able to exhibit sealing properties, and if the amount is 350 parts by mass or less, there is no risk of a decrease in surface curability.

[0025] The curing accelerator (C) used in the present invention is a curing accelerator. There are no particular limitations on the curing accelerator, so long as it can accelerate the effects of the curing accelerator (B). To suppress foaming during heat curing, a curing accelerator that is liquid at 25°C is preferred. It is more preferred to contain one or more compounds selected from the group consisting of imidazole compounds, amine compounds, and polyol compounds, with a tertiary amine compound being the most preferred. Specific examples of tertiary amine compounds include N,N,N',N'-tetramethyl-1,3-diaminopropane, N,N,N',N'-tetramethyl-1,6-diaminohexane, N,N-dimethylbenzylamine, N-methyl-N-(dimethylaminopropyl)aminoethanol, (dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, tripropylamine, diazabicycloundecene, and diazabicyclononene. Specific examples of polyol compounds include aliphatic polyols such as ethylene glycol, propylene glycol, 1,4-butanediol, 1,3-butanediol, 1,9-nonanediol, neopentyl glycol, tricyclodecane dimethylol, cyclohexane dimethylol, trimethylolpropane, glycerin, hydrogenated polybutadiene polyol, and hydrogenated dimer diol; (poly)ether polyols having one or more ether bonds such as diethylene glycol, tripropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, trimethylolpropane polyethoxytriol, glycerin polypropoxytriol, bisphenol A polyethoxydiol, bisphenol F polyethoxydiol, and ditrimethylolpropane; polyester polyol compounds; polycaprolactone polyol compounds; polyol compounds having a phenolic hydroxyl group; and polycarbonate polyols such as polycarbonate diol. These may be used alone or in combination of two or more. From the viewpoints of suppressing foaming of the curable resin composition and accelerating the curing of component (B), it is preferred that 2,4,6-tris(dimethylaminomethyl)phenol be contained.

[0026] When the component (C) is liquid at 25°C, from the viewpoint of improving adhesive strength and cohesive failure rate, the viscosity at 25°C is preferably 1 to 10,000 mPa·s, more preferably 10 to 5,000 mPa·s, and most preferably 100 to 1,000 mPa·s.

[0027] When the component (C) is solid at 25°C, it preferably has a melting point of 30 to 80°C, more preferably 40 to 75°C, and most preferably 50 to 70°C.

[0028] The blending amount of the (C) component is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, and most preferably 1.0 to 10 parts by mass, per 100 parts by mass of the (B) component. By blending the (C) component in an amount of 0.1 to 20 parts by mass, there is no risk of deterioration in curability and storage stability.

[0029] The component (D) used in the present invention is a compound having one or more (meth)acryloyl groups and one or more phosphate groups per molecule. The inclusion of component (D) can improve the cohesive failure rate and also suppress foaming during the heat curing process. From the viewpoint of improving the cohesive failure rate, a compound having a structure of general formula (1) is preferred, and a in general formula (1) is preferably 1 to 5, and most preferably 2.

[0030] [ka] (a and b are integers greater than or equal to 1, and b = 2a; n is an integer of 1 or 2) A specific example of the component (D) is 2-hydroxyethyl (meth)acrylate acid phosphate.

[0031] The curable resin composition of the present invention preferably does not contain any compound having a (meth)acryloyl group in one molecule other than component (D). If the curable resin composition contains any compound having a (meth)acryloyl group other than component (D), the cohesive failure rate decreases, and stable adhesive performance cannot be obtained.

[0032] The blending amount of the (D) component is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and most preferably 0.5 to 5 parts by mass, per 100 parts by mass of the (A) component. By blending the (D) component in an amount of 0.01 to 20 parts by mass, there is no risk of the cohesive failure rate decreasing.

[0033] The curable resin composition of the present invention can further contain a plasticizer as component (E). Component (E) is not particularly limited, but examples include compounds having a polyether skeleton. A polyether skeleton refers to a skeleton having an alkylene oxide, such as polypropylene glycol, polyethylene glycol, or polybutylene glycol. From the viewpoint of not reducing the cohesive failure rate, component (E) is preferably a non-reactive plasticizer, more preferably a non-reactive plasticizer not containing an epoxy group or a (meth)acryloyl group, and most preferably a compound having a polyether skeleton. From the viewpoint of not reducing adhesive strength, the viscosity of component (E) is preferably 0.1 to 100 mPa·s at 25°C, more preferably 0.5 to 80 mPa·s, and most preferably 1 to 50 mPa·s. The viscosity (25°C) in the present invention is a value measured using a cone-plate viscometer.

[0034] The component (E) is preferably contained in an amount of 1 to 100 parts by mass, more preferably 5 to 80 parts by mass, and most preferably 10 to 50 parts by mass, relative to 100 parts by mass of the component (A). When the amount is 1 to 100 parts by mass, there is no risk of a decrease in adhesive strength or cohesive failure rate. Furthermore, the component (E) is preferably contained in an amount of 0.1 to 20% by mass, more preferably 0.5 to 20% by mass, and preferably 1 to 10% by mass, relative to 100% by mass of the entire curable resin composition. When the curable resin composition is a two-component type, the component (E) is preferably contained in an amount of 1 to 50% by mass, more preferably 3 to 30% by mass, and most preferably 5 to 15% by mass, relative to 100% by mass of the entire first or second liquid.

[0035] The curable resin composition of the present invention can further contain an inorganic filler as component (F). Component (F) is not particularly limited, but examples include alumina powder, calcium carbonate powder, talc powder, silica powder, fumed silica powder, silver powder, nickel powder, palladium powder, carbon powder, tungsten powder, and plating powder. From the viewpoint of not reducing adhesive strength and cohesive failure rate, calcium carbonate powder is preferred, precipitated calcium carbonate powder is more preferred, and colloidal calcium carbonate powder is most preferred. The average particle size of component (E) is preferably 0.001 to 10 μm, more preferably 0.01 to 1 μm, and most preferably 0.02 to 0.5 μm, from the viewpoint of not reducing cohesive failure rate. When using a fine-particle-sized component (E), it is preferable that the component (E) is surface-treated with a fatty acid. The average particle size of component (E) is the particle size at a cumulative volume ratio of 50% (D50) in the particle size distribution determined by laser diffraction scattering.

[0036] The amount of the (F) component is preferably 10 to 300 parts by mass, more preferably 20 to 250 parts by mass, and most preferably 50 to 200 parts by mass, relative to 100 parts by mass of the (A) component. When the amount is 10 to 300 parts by mass, there is no risk of a decrease in adhesive strength or cohesive failure rate. When the curable resin composition is a two-component type, the amount of the (F) component is preferably 10 to 80% by mass, more preferably 20 to 70% by mass, and most preferably 30 to 60% by mass, relative to 100% by mass of the entire first or second liquid.

[0037] Furthermore, the composition may further contain appropriate amounts of additives such as organic fillers, pigments, dyes, silane coupling agents, leveling agents, rheology control agents, and storage stabilizers, as long as the properties of the present invention are not impaired.

[0038] The organic filler may be a solid organic material composed of rubber, elastomer, plastic, polymer (or copolymer), etc. It may also be an organic filler having a multilayer structure such as a core-shell type. The average particle size of the organic filler is preferably in the range of 0.05 to 50 μm. From the viewpoint of improving properties in durability tests, it is preferable to include a filler composed of a polymer or copolymer of an acrylic acid ester and / or a (meth)acrylic acid ester, or a filler composed of a polymer or copolymer of a styrene compound. The preferred blending amount of the organic filler is preferably 1 to 50 parts by mass, more preferably 5 to 30 parts by mass, per 100 parts by mass of (A).

[0039] Examples of the silane coupling agent include glycidyl group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldipropyloxysilane, 3-glycidoxypropyldimethylmonomethoxysilane, 3-glycidoxypropyldimethylmonoethoxysilane, 3-glycidoxypropyldimethylmonopropyloxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropylmethyldiethoxysilane; vinyl group-containing silane coupling agents such as vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, and vinyltrimethoxysilane; 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropylmethyldipropyloxysilane. Examples of suitable silane coupling agents include (meth)acrylic group-containing silane coupling agents such as propyl dimethyl monomethoxy silane, 3-methacryloxypropyl dimethyl monoethoxy silane, 3-acryloxypropyl methyl dipropyl oxy silane, 3-acryloxypropyl methyl dimethoxy silane, 3-acryloxypropyl methyl diethoxy silane, 3-acryloxypropyl methyl dipropyl oxy silane, 3-acryloxypropyl dimethyl monopropyl oxy silane, 3-acryloxypropyl dimethyl monomethoxy silane, 3-acryloxypropyl dimethyl monoethoxy silane, 3-acryloxypropyl dimethyl monopropyl oxy silane, and γ-methacryloxypropyl trimethoxy silane; amino group-containing silane coupling agents such as N-β-(aminoethyl)-γ-aminopropyl trimethoxy silane, γ-aminopropyl triethoxy silane, and N-phenyl-γ-aminopropyl trimethoxy silane; γ-mercaptopropyl trimethoxy silane; and γ-chloropropyl trimethoxy silane. These may be used alone or in combination of two or more.From the viewpoint of foaming, the curable resin composition of the present invention preferably contains 0 to 0.5 mass % of a silane coupling agent relative to 100 mass % of the entire curable resin composition, and more preferably does not contain any.

[0040] The storage stabilizer may be boric acid ester, phosphoric acid, alkyl phosphate ester, or p-toluenesulfonic acid. Examples of boric acid ester include, but are not limited to, tributyl borate, trimethoxyboroxine, and ethyl borate. Examples of alkyl phosphate ester include, but are not limited to, trimethyl phosphate and tributyl phosphate. The storage stabilizer may be used alone or in combination. Considering the effect on cure shrinkage, one or more selected from the group consisting of phosphoric acid, alkyl phosphate ester, boric acid ester, trimethoxyboroxine, and methyl p-toluenesulfonate are preferred, with phosphoric acid and boric acid ester being most preferred. From the viewpoint of maintaining curability, the preferred amount of storage stabilizer is 0.1 to 10 parts by mass per 100 parts by mass of component (A) of the present invention.

[0041] <Application method> The curable resin composition of the present invention can be applied to an adherend by a known method for applying a sealant or adhesive, such as dispensing using an automatic coater, spraying, inkjet printing, screen printing, gravure printing, dipping, or spin coating.

[0042] <Curing Method> The curable resin composition of the present invention can be cured at room temperature. In the present invention, room temperature means a temperature of 20° C. or higher but lower than 30° C. The curing time is not particularly limited, but at room temperature, it is preferably 1 minute or longer but shorter than 24 hours, and more preferably 1 hour or longer but shorter than 2 hours.

[0043] <Two-component curable resin composition> From the viewpoint of storage stability, the curable resin composition of the present invention preferably consists of two parts. The two-part curable resin composition of the present invention consists of a first part (main agent) and a second part (curing agent), and the first part preferably contains components (A) and (D), and the second part preferably contains components (B) and (C). Components (E) and (F) can be contained in either or both of the first and second parts. From the viewpoint of storage stability of the second part, it is preferable that component (D) be contained in the first part. From the viewpoint of workability, it is preferable that the first and second parts are mixed at a mixing ratio of first part mass:second part mass = 40:60 to 60:40.

[0044] <Application> The curable resin composition of the present invention can be used in a variety of applications. Specific examples include adhesion, sealing, casting, coating, etc. of automotive switches, headlamps, engine internal parts, electrical components, drive engines, brake oil tanks, front hoods, fenders, body panels such as doors, windows, etc.; in the electronic materials field, adhesion, sealing, casting, coating, etc. of flat panel displays (liquid crystal displays, organic EL displays, light-emitting diode displays, field emission displays), video discs, CDs, DVDs, MDs, pickup lenses, hard disks, etc.; in the battery field, lithium batteries, lithium ion batteries, manganese batteries, alkaline batteries, fuel cells, and silicon solar cells. , dye-sensitized batteries, organic solar cells, etc.; in the optical components field, optical fiber materials around optical switches and optical connectors, optical passive components, optical circuit components, and optoelectronic integrated circuits, etc.; in the optical equipment field, camera modules, lens materials, viewfinder prisms, target prisms, viewfinder covers, light-receiving sensors, photographic lenses, our company's lenses for projection TVs, etc.; in the infrastructure field, it can be used as an adhesive, lining material, sealant, coating material for gas pipes, water pipes, etc., but due to its excellent adhesive performance, it is suitable for adhesive and sealant applications. [Example]

[0045] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0046] [Examples 1 and 2, Comparative Examples 1 to 16] The following components were prepared to prepare a curable resin composition.

[0047] (A-1) Component: Bisphenol A epoxy resin. Product name: jER828 (Mitsubishi Chemical Corporation). Viscosity (25°C): 13 Pa·s. Epoxy equivalent: 190 g / eq. Component (B-1): A polymer with a polyether skeleton but no disulfide bond in the main chain, and with three or more thiol groups per molecule. Product name: Polythiol QE-340M (Toray Fine Chemicals Co., Ltd.) Component (B-2): A polymer having a disulfide bond and a polyether skeleton in the main chain and a thiol group at the end. Product name: Thiokol LP-3 (Toray Fine Chemicals Co., Ltd.). Average molecular weight: 1,000. (C-1) Ingredient: 2,4,6-tris(dimethylaminomethyl)phenol Product name: Ancamine K54 Viscosity (25°C): 200 mPa·s Component (D-1): A compound having the structure of general formula (1), in which a in general formula (1) is 2 and n is a mixture of 1 and 2. Product name: JPA-514 (Johoku Chemical Industry Co., Ltd.) (D-2) Component: Mono(2-hydroxyethyl methacrylate) phosphate. Product name: JAMP-514 (Johoku Chemical Industry Co., Ltd.) Component (D'-1): 3-glycidoxypropyltrimethoxysilane, product name: KBM-403 (Shin-Etsu Chemical Co., Ltd.) (D'-2) Component: Phosphoric acid (reagent) (D'-3) Component: Bis(decyl)pentaerythritol diphosphite Product name: JPE-10 (D'-4) Component: Tridecyl phosphite Product name: JP-310 (Johoku Chemical Industry Co., Ltd.) (D'-5) Component: Triphenyl phosphite Product name: JP-360 (Johoku Chemical Industry Co., Ltd.) (D'-6) Ingredient: Trade name: 4,4'-butylidenebis(3-methyl-6-t-butylphenyl ditridecyl phosphite) JPH-1200 (Johoku Chemical Industry Co., Ltd.) (D'-7) Ingredient: Ethyl acid phosphate Product name: JP-502 (Johoku Chemical Industry Co., Ltd.) (D'-8) Component: Butyl acid phosphate Product name: JP-504 (Johoku Chemical Industry Co., Ltd.) (D'-9) Ingredient: Oleyl acid phosphate Product name: JP-518-O (Johoku Chemical Industry Co., Ltd.) (D'-10) Ingredient: Dibutyl phosphate, product name: DBP (Johoku Chemical Industry Co., Ltd.) (D'-11) Ingredient: Butoxyethyl acid phosphate; Product name: JP-506H (Johoku Chemical Industry Co., Ltd.) (D'-12) Ingredient: Isobornyl methacrylate. Product name: Acryester IBX (Mitsubishi Chemical Corporation). (D'-13) Component: 2-hydroxyethyl methacrylate Product name: Acryester HO (Mitsubishi Chemical Corporation) (D'-14) Component: 3-aminopropyltrimethoxysilane Product name: KBM-903 (Shin-Etsu Chemical Co., Ltd.) (E-1) Component: Phenol-PO addition plasticizer. Product name: Adeka Glycirol ED-508 (ADEKA Corporation). (F-1) Ingredient: Colloidal calcium carbonate powder surface-treated with fatty acid. Product name: Hakuenka CCR (Shiraishi Kogyo Co., Ltd.). Average particle size: 0.08 μm.

[0048] The components (A), (D), (E), and (F) were weighed into a mixing vessel and stirred in a mixer for 30 minutes to obtain a first liquid. Then, components (C) and (D) or (D') were added to component (B), and the mixture was stirred in a mixer for 10 minutes to obtain a second liquid. Detailed amounts are listed in Table 1 or Table 2, and all values ​​are expressed in parts by mass. All tests were performed at 25°C. Note that hereinafter, the term "curable resin composition" refers to the mixture of the first and second liquids.

[0049] [Table 1]

[0050] [Shear adhesive strength] Within 30 minutes, each curable resin composition (a 50g:50g mixture of the first and second liquids) from each of the Examples and Comparative Examples was applied to a 25mm wide x 100mm long x 1.6mm thick SPCC-SD test piece. Similar test pieces were then attached together to a 25mm x 10mm overlap, secured with clips, and cured for 1 hour and 30 minutes at 25°C. The test pieces were then placed in a hot air oven at 180°C for 20 minutes to obtain test pieces. The shear bond strength (unit: MPa) was measured at 25°C using a universal tensile tester (tensile speed: 10mm / min) in accordance with JIS K 6850:1999, and evaluated according to the following criteria: Pass criteria: 1.0 MPa or more

[0051] [Cohesive failure rate] After the shear adhesive strength test, the state of failure of the test piece was visually confirmed, and the occupied area ratio of the cohesive failure state was calculated. Pass criteria: 100% or more (CF100 represents 100% cohesive failure)

[0052] [Foaming or not] After the shear adhesive strength test, the state of fracture of the test piece was visually confirmed, and it was also visually confirmed whether there were any signs of foaming such as voids inside the cured product. Pass criteria: No foaming

[0053] [Pot life] Each of the first and second liquids in Table 1 was weighed out and placed in an aluminum metal container 6 mm thick and 50 mm in diameter, with a ratio of 50 g of first liquid to 50 g of second liquid. The container was then secured and mixed with a wooden stirring rod in a circular motion at 2 revolutions per second for 10 seconds. Stirring was repeated every 30 minutes, and the time from the start of stirring until the mixed curable resin composition no longer flowed was measured. Passing criteria: 1.5h or more

[0054] [Table 2]

[0055] As shown in Tables 1 and 2, Examples 1 and 2 exhibited good results in both adhesive strength and cohesive failure rate, and no foaming from the composition was observed. On the other hand, Comparative Example 1, which did not contain component (D), exhibited a low cohesive failure rate, indicating that it did not have stable adhesive performance. Comparative Examples 2 to 4, which used a silane coupling agent instead of component (D), exhibited good cohesive failure rates, but significantly lower adhesive strength and foaming was observed. Comparative Examples 5 to 8 and 10 to 14, which used component (D') without a (meth)acryloyl group, all exhibited low cohesive failure rates. Comparative Example 9, which used phosphoric acid instead of component (D), exhibited low adhesive strength and foaming was observed. Furthermore, Comparative Examples 15 and 16, which used component (D') without a phosphate group but with a (meth)acryloyl group, exhibited low cohesive failure rates. Furthermore, Examples 1 and 2 also exhibited better pot life than Comparative Example 1, which did not contain component (D), demonstrating excellent workability after mixing. These findings show that by including components (A) to (D), high adhesive strength and cohesive failure rate are achieved, stable adhesive performance is obtained, and foaming during heat curing can be suppressed. [Industrial Applicability]

[0056] The curable resin composition of the present invention has high adhesive strength, provides stable adhesive performance, and can suppress foaming from within the composition even after undergoing a heating process, and is therefore useful in various fields as an adhesive, coating agent, or potting agent.

Claims

1. A curable resin composition comprising the following components (A) to (D): Component (A): a compound having two or more epoxy groups Component (B): Thiol curing agent Component (C): Curing accelerator Component (D): A compound having one or more (meth)acryloyl groups and one or more phosphate groups per molecule.

2. 2. The curable resin composition according to claim 1, wherein the first liquid contains the components (A) and (D), and the second liquid contains the components (B) and (C).

3. 3. The curable resin composition according to claim 1, which does not contain any compound having a (meth)acryloyl group in one molecule (excluding component (D)).

4. 3. The curable resin composition according to claim 1, wherein the component (B) is (B-1) a thiol curing agent having a polyether skeleton and no disulfide bond in its main chain and / or (B-2) a thiol curing agent having a disulfide bond in its main chain.

5. The curable resin composition according to claim 1 or 2, wherein the component (C) is liquid at 25°C.

6. The curable resin composition according to claim 2, further comprising a plasticizer as component (E) in the first liquid and / or the second liquid.

7. The curable resin composition according to claim 2, further comprising an inorganic filler as component (F) in the first liquid and / or the second liquid.

8. The curable resin composition according to claim 1 or 2, which does not contain a silane coupling agent.

9. The curable resin composition according to claim 7, wherein the component (F) is colloidal calcium carbonate powder.

10. A cured product obtained by curing the curable resin composition according to claim 1 or 2.

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