Single-dosage thermosetting resin composition and use thereof

Abstract

The present invention addresses the problem of providing a novel single-form thermosetting resin composition which has excellent storage stability and can provide a cured product having excellent adhesive strength by curing at low temperatures. A single-dosage-form thermosetting resin composition which contains specific amounts of an epoxy resin, polymer particles, dicyandiamide, and an amine adduct curing agent, respectively, and has specific exothermic onset temperature and exothermic peak temperature, and in addition, has excellent heat resistance and heat resistance. The composition satisfies at least one of the following (1)-(3): (1) the composition has a specific amount of a urea compound, (2) the composition has a specific amount of an epoxy reactive diluent, or (3) the shell layer of the polymer particles has a specific amount of an epoxy group.

Description

Technical Field

[0001] The present invention relates to a single-component thermosetting resin composition and its use. Background Art

[0002] As described in Patent Documents 1 to 4, thermosetting resin compositions containing epoxy resins are used in a wide range of fields. For example, in Patent Document 1 or Patent Document 3, they are disclosed as structural adhesives.

[0003] However, currently, in the field of structural adhesives, from the perspective of responding to carbon neutrality, low-temperature curing is required. In addition, as an adhesive, there has been a tendency to require adhesive physical properties and storage stability in the past.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent No. 6955661

[0007] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2015-54940

[0008] Patent Document 3: Japanese Patent No. 7109164

[0009] Patent Document 4: Japanese Unexamined Patent Application Publication No. 2018-80310 Summary of the Invention

[0010] Problems to be Solved by the Invention

[0011] From the viewpoints of the adhesive physical properties of the cured product obtained by low-temperature curing and / or the storage stability of the thermosetting resin composition in a single-liquid (single-component) type, the conventional thermosetting resin compositions are insufficient, and there is room for further improvement.

[0012] One embodiment of the present invention has been made in view of the above-described situation, and an object thereof is to provide a novel single-component thermosetting resin composition having excellent storage stability and capable of providing a cured product having excellent adhesive strength by low-temperature curing.

[0013] Means for Solving the Problems

[0014] In order to solve the above problems, the present inventors have conducted intensive studies, and as a result, the present invention has finally been completed.

[0015] That is, a single-component thermosetting resin composition according to an embodiment of the present invention contains an epoxy resin (A), and further contains, based on 100 parts by mass of the epoxy resin (A): 1 part by mass to 100 parts by mass of polymer particles (B) having a core-shell structure including a core layer and a shell layer, 3.5 parts by mass to 19.0 parts by mass of dicyandiamide (C), and 0.3 parts by mass to 10.0 parts by mass of an amine adduct curing agent (D) that is solid at room temperature. In the DSC curve of the single-component thermosetting resin composition measured using a differential scanning calorimeter under the condition of a heating rate of 10 °C / minute, the exothermic start temperature is 80 °C or higher, and the exothermic peak temperature is 150 °C or lower. The single-component thermosetting resin composition satisfies at least one selected from the following (1) to (3):

[0016] (1) Further contains 0.5 parts by mass to 15.0 parts by mass of a urea compound (E) represented by the general formula (X);

[0017] R 1 -NH-C(=O)-N-R 2 2…(X)

[0018] (In the formula, R 1 is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, and two Rs 2 are each independently a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms.);

[0019] The ratio (Wc / We) of the total mass Wc of the dicyandiamide (C) to the total mass We of the urea compound (E) is 1.1 to 20.0, and the ratio (We / Wd) of the total mass We of the urea compound (E) to the total mass Wd of the amine adduct curing agent (D) is 1.1 to 20.0;

[0020] (2) Further contains 1.0 part by mass to 20.0 parts by mass of an epoxy-based reactive diluent (F); and

[0021] (3) The shell layer of the polymer particles (B) has an epoxy group, and the content of the epoxy group in the shell layer exceeds 0 mmol / g and is 2.0 mmol / g or less based on the total mass of the shell layer.

[0022] Effects of the Invention

[0023] According to an embodiment of the present invention, a novel single-component thermosetting resin composition with excellent storage stability can be provided, and a cured product with excellent adhesive strength through low-temperature curing can be provided. Detailed Embodiments

[0024] An embodiment of the present invention will be described below, but the present invention is not limited thereto. The present invention is not limited to each of the embodiments described below, and various modifications can be made within the scope shown in the claims of the patent. Embodiments and examples obtained by appropriately combining the technical means disclosed in different embodiments and examples are also included in the technical scope of the present invention. In addition, all the academic literatures and patent literatures described in this specification are incorporated herein by reference. In addition, in this specification, unless otherwise specifically marked, "A to B" indicating a numerical range means "A or more and B or less".

[0025] [1. Curable Resin Composition]

[0026] A one-component thermosetting resin composition according to an embodiment of the present invention contains an epoxy resin (A), and per 100 parts by mass of the epoxy resin (A), further contains: 1 part by mass to 100 parts by mass of polymer particles (B) having a core-shell structure including a core layer and a shell layer, 3.5 parts by mass to 19.0 parts by mass of dicyandiamide (C), and 0.3 parts by mass to 10.0 parts by mass of an amine adduct curing agent (D) that is solid at room temperature. In the DSC curve of the one-component thermosetting resin composition measured using a differential scanning calorimeter at a heating rate of 10 °C / minute, the exothermic start temperature is 80 °C or higher, and the exothermic peak temperature is 150 °C or lower. The one-component thermosetting resin composition satisfies at least one of the following (1) to (3):

[0027] (1) Further contains 0.5 parts by mass to 15.0 parts by mass of a urea compound (E) represented by the general formula (X);

[0028] R 1 -NH-C(=O)-N-R 2 2…(X)

[0029] (In the formula, R 1 is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, and two R 2 are each independently a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms.);

[0030] The ratio (Wc / We) of the total mass Wc of the dicyandiamide (C) to the total mass We of the urea compound (E) is 1.1 to 20.0, and the ratio (We / Wd) of the total mass We of the urea compound (E) to the total mass Wd of the amine adduct curing agent (D) is 1.1 to 20.0;

[0031] (2) Further contains 1.0 part by mass to 20.0 parts by mass of an epoxy-based reactive diluent (F); and

[0032] (3) The shell of the above polymer particles (B) has epoxy groups, and the content of the above epoxy groups in the shell is more than 0 mmol / g and 2.0 mmol / g or less with respect to the total mass of the shell.

[0033] In this specification, "epoxy resin (A)", "polymer particles (B)", "dicyandiamide (C)", "amine adduct curing agent (D)", "urea compound (E)", and "epoxy reactive diluent (F)" may be sometimes abbreviated as "(A) component", "(B) component", "(C) component", "(D) component", "(E) component", and "(F) component", respectively. In addition, in this specification, "one-component thermosetting resin composition" may be sometimes referred to as "composition", and "one-component thermosetting resin composition according to one embodiment of the present invention" may be sometimes referred to as "this composition".

[0034] This composition may only meet the above (1), may only meet the above (2), may also only meet the above (3), may only meet the above (1) and (2), may only meet the above (1) and (3), may also only meet (2) and (3), or may even meet all of the above (1), (2) and (3). In this specification, for the single-component thermosetting resin composition of one embodiment of the present invention, the "single-component thermosetting resin composition that meets the above (1)" is sometimes referred to as "the single-component thermosetting resin composition (I) of one embodiment of the present invention" or "composition (I)", the "single-component thermosetting resin composition that meets the above (2)" is sometimes referred to as "the single-component thermosetting resin composition (II) of one embodiment of the present invention" or "composition (II)", and the "single-component thermosetting resin composition that meets the above (3)" is sometimes referred to as "the single-component thermosetting resin composition (III) of one embodiment of the present invention" or "composition (III)". In this specification, for the single-component thermosetting resin composition of one embodiment of the present invention, the "single-component thermosetting resin composition that meets the above (1) and (2)" is sometimes referred to as "the single-component thermosetting resin composition (I)+(II) of one embodiment of the present invention" or "composition (I)+(II)", the "single-component thermosetting resin composition that meets the above (1) and (3)" is sometimes referred to as "the single-component thermosetting resin composition (I)+(III) of one embodiment of the present invention" or "composition (I)+(III)", the "single-component thermosetting resin composition that meets the above (2) and (3)" is sometimes referred to as "the single-component thermosetting resin composition (II)+(III) of one embodiment of the present invention" or "composition (II)+(III)", and the "single-component thermosetting resin composition that meets all of the above (1), (2) and (3)" is sometimes referred to as "the single-component thermosetting resin composition (I)+(II)+(III) of one embodiment of the present invention" or "composition (I)+(II)+(III)". This composition includes composition (I), composition (II), composition (III), composition (I)+(II), composition (I)+(III), composition (II)+(III), and (I)+(II)+(III).

[0035] Due to the above composition, this composition has the following advantages: it can provide a cured product with excellent adhesive strength through low-temperature curing; and it has excellent storage stability.

[0036] It should be noted that in this specification, "able to provide a cured product having excellent adhesive strength through low-temperature curing" and "the cured product has excellent adhesive strength" mean that at a low temperature (for example, 120 °C), for example, the shear adhesive strength of the cured product obtained by curing the composition for 20 minutes is large (for example, 7 MPa or more). The method for measuring the shear adhesive strength of the cured product will be described in detail in the examples below.

[0037] It can be considered that the greater the above-mentioned shear adhesive strength of the cured product, the more excellent the adhesive strength of the cured product. For one embodiment of the present invention, the adhesive strength of the cured product obtained by low-temperature curing of this composition is preferably 7 MPa or more, more preferably 11 MPa or more, and further preferably 15 MPa or more.

[0038] In addition, in this specification, "excellent storage stability" means that, for example, when the composition is stored (placed) under given conditions, the composition does not gel after storage. As the conditions for storing (placing) the composition, for example, the case of storing (placing) at 40 °C for 14 days can be cited.

[0039] For one embodiment of the present invention, the storage stability of the composition can be evaluated by the ratio of the viscosity of the composition after storage to the viscosity of the composition before storage (viscosity of the composition after storage / viscosity of the composition before storage) when the composition is stored (placed) under given conditions. In this specification, sometimes the "viscosity of the composition after storage / viscosity of the composition before storage" is referred to as the "viscosity increase rate after storage". For one embodiment of the present invention, for example, when the composition is stored (placed) at 40 °C for 14 days, the viscosity increase rate after storage is preferably 0.5 to 20.0, more preferably 0.5 to 15.0, more preferably 0.5 to 13.0, more preferably 0.6 to 10.0, more preferably 0.6 to 9.0, further preferably 0.7 to 4.0, and particularly preferably 0.8 to 2.0.

[0040] This composition can provide a cured product having excellent adhesive strength through low-temperature curing, so the energy required for curing the composition can be reduced, thereby reducing production costs. Such an effect contributes to the achievement of, for example, Goal 7 of the Sustainable Development Goals (SDGs) advocated by the United Nations: "Ensure access to affordable, reliable, and sustainable modern energy for all." In addition, this composition can reduce the carbon dioxide emissions associated with the curing of the composition, and has the advantage of reducing greenhouse gases. Such an effect also contributes to the achievement of, for example, Goal 13 advocated by the United Nations: "Take urgent action to combat climate change and its impacts."

[0041] The object of the present inventors is to provide a single-component thermosetting resin composition having excellent storage stability and capable of providing a cured product having excellent adhesive strength by low-temperature curing, and they have conducted intensive research. As a result, the inventors have independently found the following new insights: One or more compositions selected from the above compositions (I), (II), (III), (I)+(II), (I)+(III), (II)+(III), and (I)+(II)+(III) surprisingly can provide a cured product having excellent adhesive strength by low-temperature curing and have excellent storage stability, thus completing the present invention.

[0042] For example, composition (I) contains a combination of three components: dicyandiamide (C), an amine adduct curing agent (D), and a urea compound (E) that can contribute to the curing reaction, and the content of each is within a specific range. Thus, it has the advantages of being able to provide a cured product having excellent adhesive strength by low-temperature curing and having excellent storage stability. During the intensive research, the present inventors independently obtained the following insights: In the case where the composition contains component (F) or the shell layer does not contain a specific amount of epoxy groups, a composition containing only any two of components (C), (D), and (E) cannot have both excellent adhesive strength of the cured product obtained by low-temperature curing and excellent storage stability.

[0043] In addition, composition (II) contains an epoxy reactive diluent (F) in addition to using dicyandiamide (C) and an amine adduct curing agent (D), and the content of each is within a specific range. Thus, it has the advantages of being able to provide a cured product having excellent adhesive strength by low-temperature curing and having excellent storage stability. The reason why the composition having the above advantages is formed by containing three components of dicyandiamide (C), an amine adduct curing agent (D), and an epoxy reactive diluent (F) is not clear, but based on the obtained results, the present inventors made the following speculation: By containing the epoxy reactive diluent (F), the flexibility of the obtained cured product is improved, and thus the adhesive strength of the cured product is increased. It should be noted that one embodiment of the present invention is not limited to such speculation.

[0044] The composition of one embodiment of the present invention is preferably (i) composition (I) and composition (II), i.e., composition (I)+(II); preferably (ii) composition (I) and composition (III), i.e., composition (I)+(III); preferably (iii) composition (II) and composition (III), i.e., composition (II)+(III); particularly preferably (iv) composition (I), composition (II) and composition (III), i.e., composition (I)+(II)+(III). In other words, the composition of one embodiment of the present invention preferably satisfies both the conditions of (i) composition (I) and composition (II), i.e., both (1) and (2) above; preferably satisfies both the conditions of (ii) composition (I) and composition (III), i.e., both (1) and (3) above; preferably satisfies both the conditions of (iii) composition (II) and composition (III), i.e., both (2) and (3) above; particularly preferably satisfies all the conditions of (iv) composition (I), composition (II) and composition (III), i.e., all of (1), (2) and (3) above.

[0045] <Epoxy resin (A)>

[0046] As the epoxy resin (A), various epoxy resins can be used.

[0047] Examples of the epoxy resin include: for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, bisphenol S type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, novolak type epoxy resin, glycidyl ether type epoxy resin of bisphenol A propylene oxide adduct, hydrogenated bisphenol A (or F) type epoxy resin, fluorinated epoxy resin, flame-retardant epoxy resins such as glycidyl ether of tetrabromobisphenol A, glycidyl ether ester type epoxy resin of p-hydroxybenzoic acid, m-aminophenol type epoxy resin, diaminodiphenylmethane series epoxy resin, various alicyclic epoxy resins, N,N-diglycidylaniline, N,N-diglycidyl-o-toluidine, triglycidyl isocyanurate, divinylbenzene dioxide, resorcinol diglycidyl ether, chelate-modified epoxy resin, rubber-modified epoxy resin, urethane-modified epoxy resin, hydantoin type epoxy resin, epoxide of unsaturated polymers such as petroleum resin, amino-containing glycidyl ether resin, epoxy compounds obtained by addition reaction of bisphenol A (or F) type or polyacid type, etc. with the above epoxy resins.

[0048] Examples of the epoxy compound obtained by addition reaction of polyacid type, etc. with epoxy resin include: for example, the addition reaction product of dimer (dimer acid) of tall oil fatty acid and bisphenol A type epoxy resin described in International Publication No. 2010-098950.

[0049] The epoxy resin (A) is not limited to these, and general-purpose epoxy resins can be used. These epoxy resins (A) can be used alone or in combination of two or more.

[0050] Here, for the purposes of this specification, the epoxy resin (A) does not include polyalkylene glycol diglycidyl ether, glycol diglycidyl ether, diglycidyl esters of aliphatic polyacids, glycidyl ethers of polyhydric aliphatic alcohols with two or more hydroxyl groups, and monocyclic oxides. Compared with the above epoxy resins, these polyalkylene glycol diglycidyl ether, glycol diglycidyl ether, diglycidyl esters of aliphatic polyacids, glycidyl ethers of polyhydric aliphatic alcohols with two or more hydroxyl groups, and monocyclic oxides have a lower viscosity (for example, 500 mPa·s or less at 25°C). In other words, in this specification, epoxy resins with a viscosity of 500 mPa·s or less at 25°C are not included in the epoxy resin (A).

[0051] The above rubber-modified epoxy resin is obtained by reacting rubber with an epoxy group-containing compound, and has 1.1 or more epoxy groups per molecule on average, preferably 2 or more reaction products. As the rubber-modified epoxy resin, for example, the resins described in paragraphs

[0124] to

[0132] of WO2016-163491 can be used.

[0052] As the above chelate-modified epoxy resin, for example, the resins described in paragraphs

[0018] to

[0019] of WO2016-163491 can be used.

[0053] As the above urethane-modified epoxy resin, for example, the resins described in paragraphs

[0133] to

[0135] of WO2016-163491 can be used.

[0054] Among these epoxy resins, from the viewpoints of strong curability, flexibility of the cured product, and excellent effect of improving the impact peel resistance of the cured product by blending the polymer particles (B), etc., those having at least 2 epoxy groups in one molecule are preferred. Particularly preferred are compounds having 2 epoxy groups in one molecule.

[0055] Among the above-mentioned epoxy resins, the cured products obtained from bisphenol A-type epoxy resin and bisphenol F-type epoxy resin have high elastic modulus, excellent heat resistance and adhesiveness, and are relatively inexpensive. Therefore, epoxy resin (A) preferably contains bisphenol A-type epoxy resin and / or bisphenol F-type epoxy resin, and more preferably consists of bisphenol A-type epoxy resin and / or bisphenol F-type epoxy resin (only composed of them). In addition, a curable resin composition capable of providing a cured product with excellent heat resistance can be obtained at a low price. Therefore, epoxy resin (A) is further preferably contains bisphenol A-type epoxy resin, and particularly preferably consists of bisphenol A-type epoxy resin (only composed of it).

[0056] The epoxy equivalent of epoxy resin (A) is preferably less than 220 g / eq, more preferably 90 g / eq or more and less than 210 g / eq, and further preferably 135 g / eq or more and less than 200 g / eq. Based on this composition, there is an advantage that a cured product with high elastic modulus and heat resistance can be obtained.

[0057] In this specification, the epoxy equivalent refers to the molecular weight per one epoxy group contained in a compound having an epoxy group. Specifically, it is a value calculated based on the following formula:

[0058] Epoxy equivalent (g / eq) = weight-average molecular weight (Mw) of the compound / number of epoxy groups per molecule of the compound (average number).

[0059] It should be noted that the epoxy equivalent can also be measured according to JIS K7236.

[0060] Both bisphenol A-type epoxy resin with an epoxy equivalent less than 220 g / eq and bisphenol F-type epoxy resin with an epoxy equivalent less than 220 g / eq are liquids at room temperature. Therefore, epoxy resin (A) is particularly preferably contains bisphenol A-type epoxy resin with an epoxy equivalent less than 220 g / eq and / or bisphenol F-type epoxy resin with an epoxy equivalent less than 220 g / eq. Based on this composition, the obtained composition has the advantage of more excellent storage stability.

[0061] Regarding the epoxy resin (A), the total content of bisphenol A type epoxy resin with an epoxy equivalent of less than 220 g / eq and bisphenol F type epoxy resin with an epoxy equivalent of less than 220 g / eq is preferably 60% by mass or more, more preferably 80% by mass or more, and further preferably 90% by mass or more in 100% by mass of the epoxy resin (A). Based on this constitution, the obtained cured product has the advantage of more excellent impact resistance. In the epoxy resin (A), the total content of bisphenol A type epoxy resin with an epoxy equivalent of less than 220 g / eq and bisphenol F type epoxy resin with an epoxy equivalent of less than 220 may also be 100% by mass in 100% by mass of the epoxy resin (A). In other words, the epoxy resin (A) may be bisphenol A type epoxy resin with an epoxy equivalent of less than 220 g / eq and / or bisphenol F type epoxy resin with an epoxy equivalent of less than 220 g / eq (constituted only by them).

[0062] <Polymer particles (B)>

[0063] The polymer particles (B) can exert a toughness improving effect in this composition. In other words, this composition has the advantage of being able to provide a cured product (for example, an adhesive layer) with excellent impact-resistant peel adhesiveness by containing the component (B). In addition, when the composition contains the component (B), the cured product obtained has a tendency of excellent adhesive strength. Due to having a core-shell structure, the polymer particles (B) are sometimes referred to as "core-shell polymer particles (B)".

[0064] The structure of the polymer particles (B) is not particularly limited, and preferably has at least 2 layers or more in total including a core layer and a shell layer. In addition, it may also have a structure of 3 layers or more composed of an intermediate layer covering the core layer and a shell layer further covering the intermediate layer. The polymer particles (B) are preferably core-shell polymer particles formed as follows: A monomer capable of graft copolymerization (monomer for forming a shell layer) is graft polymerized in the presence of a core layer to form a shell layer. This polymerization operation can be carried out by the following operation: Adding a monomer for forming a shell polymer layer to the latex of the core polymer prepared in an aqueous polymer latex state and polymerizing it. The polymer particles (B) may have a structure including a core layer existing inside thereof and at least one shell layer, and the shell layer covers the periphery or a part of the core layer by graft polymerization to its surface. Regarding the polymer particles (B), it is preferable that the shell polymer and the core polymer are actually chemically bonded. It should be noted that the core layer and the shell layer may not form a complete layer structure. It is sufficient that the shell polymer covers at least a part of the core layer and may not cover the whole of the core layer. In addition, a part of the shell polymer may also enter the core layer.

[0065] Hereinafter, each layer of the polymer particles (B) will be specifically described.

[0066] 《Core layer》

[0067] In order to improve the toughness of the cured product of the composition, the core layer is preferably an elastic core layer having the properties of a rubber.

[0068] From the viewpoints of good toughness improvement effect of the obtained cured product, good improvement effect of the impact peel adhesiveness of the obtained cured product, and less increase in viscosity over time due to swelling of the core layer because of poor affinity with the epoxy resin (A), the core layer preferably contains a diene rubber. By combining a variety of monomers, polymers with a wide range of compositions can be designed, so the core layer preferably contains a (meth)acrylate rubber. In addition, when improving the impact resistance at low temperatures without decreasing the heat resistance of the cured product, the core layer preferably contains a silicone rubber. In other words, the core layer preferably contains one or more selected from diene rubbers, (meth)acrylate rubbers, and silicone rubbers.

[0069] (Diene rubber)

[0070] The above diene rubber is preferably a polymer containing the following structural units: structural units derived from at least one monomer selected from conjugated diene monomers (hereinafter, sometimes simply referred to as conjugated diene units) in an amount of 50% by mass to 100% by mass, and structural units derived from vinyl monomers other than conjugated diene monomers that can copolymerize with conjugated diene monomers in an amount of 0% by mass to 50% by mass.

[0071] Examples of the above conjugated diene monomers include 1,3-butadiene, isoprene (2-methyl-1,3-butadiene), 2-chloro-1,3-butadiene, and the like.

[0072] These conjugated diene monomers can be used alone or in combination of two or more.

[0073] In 100% by mass of all the structural units constituting the core layer, the content of the conjugated diene units in the core layer is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, and further preferably 90% by mass to 100% by mass. When the content of the conjugated diene units in the core layer is 50% by mass or more, the impact peel adhesiveness of the obtained cured product can be made better.

[0074] Examples of vinyl monomers other than conjugated diene monomers that can copolymerize with conjugated diene monomers include vinyl aromatic compounds such as styrene, α-methylstyrene, monochlorostyrene, and dichlorostyrene; acrylic acids such as acrylic acid and methacrylic acid; acrylonitriles such as acrylonitrile and methacrylonitrile; vinyl halides such as vinyl chloride, vinyl bromide, and chloroprene; vinyl acetate; olefins such as ethylene, propylene, butene, and isobutene; polyfunctional monomers such as diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, and divinylbenzene.

[0075] The vinyl-based monomers other than conjugated diene monomers that can copolymerize with conjugated diene monomers can be used alone or in combination of two or more. Among the vinyl-based monomers other than conjugated diene monomers that can copolymerize with conjugated diene monomers, styrene is particularly preferred.

[0076] From the viewpoints of better improving the toughness of the obtained cured product, better improving the impact peel adhesiveness of the obtained cured product, and less likely to cause a time-dependent increase in viscosity due to swelling of the core layer because of poor affinity with the epoxy resin (A), in the diene rubber, the core layer more preferably contains butadiene rubber as a homopolymer of 1,3-butadiene and / or butadiene-styrene rubber as a copolymer of 1,3-butadiene and styrene, more preferably contains butadiene rubber and / or butadiene-styrene rubber (constituted only by them), further preferably contains butadiene rubber, and particularly preferably is butadiene rubber (constituted only by it). In addition, from the viewpoint of improving the transparency of the cured product obtained by refractive index adjustment, butadiene-styrene rubber is preferred.

[0077] ((Meth)acrylate rubber)

[0078] The above-mentioned (meth)acrylate rubber is preferably a polymer obtained by polymerizing a monomer mixture containing 50% by mass to 100% by mass of structural units derived from at least one monomer selected from (meth)acrylate monomers (hereinafter sometimes simply referred to as (meth)acrylate units) and 0% by mass to 50% by mass of structural units derived from vinyl-based monomers other than (meth)acrylate monomers that can copolymerize with (meth)acrylate monomers. It should be noted that in this specification, "(meth)acrylate" means acrylate and / or methacrylate.

[0079] Examples of the above-mentioned (meth)acrylate monomers include: (i) (meth)acrylate alkyl esters such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, octyl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, and docosyl (meth)acrylate; (ii) (meth)acrylate esters containing an aromatic ring such as phenoxyethyl (meth)acrylate and benzyl (meth)acrylate; (iii) (meth)acrylate hydroxyalkyl esters; (iv) (meth)acrylate glycidyl esters such as glycidyl (meth)acrylate and glycidylalkyl (meth)acrylate; (v) (meth)acrylate alkoxyalkyl esters; (vi) (meth)acrylate allyl esters and (meth)acrylate allylalkyl esters such as allyl (meth)acrylate and allylalkyl (meth)acrylate; (vii) polyfunctional (meth)acrylate esters such as monoethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, and tetraethylene glycol di(meth)acrylate, etc.

[0080] Examples of the (meth)acrylate hydroxyalkyl esters include: hydroxy straight-chain alkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate (especially, hydroxy straight-chain C1-6 alkyl (meth)acrylates); caprolactone-modified hydroxy (meth)acrylate; hydroxy branched-chain alkyl (meth)acrylates such as methyl α-(hydroxymethyl)acrylate and ethyl α-(hydroxymethyl)acrylate; and hydroxy-containing (meth)acrylate esters such as mono(meth)acrylate of polyester diol (especially saturated polyester diol) obtained from a dicarboxylic acid (such as phthalic acid) and a diol (such as propylene glycol), etc.

[0081] These (meth)acrylate monomers can be used alone or in combination of two or more. As the (meth)acrylate monomers, ethyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are preferred.

[0082] Examples of vinyl monomers other than (meth)acrylate monomers that can copolymerize with (meth)acrylate monomers include: (i) vinyl aromatic hydrocarbons such as styrene, α-methylstyrene, monochlorostyrene, and dichlorostyrene; (ii) acrylic acids such as acrylic acid and methacrylic acid; (iii) acrylonitriles such as acrylonitrile and methacrylonitrile; (iv) vinyl halides such as vinyl chloride, vinyl bromide, and chloroprene; (v) vinyl acetate; (vi) olefins such as ethylene, propylene, butene, and isobutene; (vii) polyfunctional monomers such as diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, and divinylbenzene, etc.

[0083] As a vinyl monomer other than (meth)acrylate monomers that can copolymerize with (meth)acrylate monomers, one kind can be used alone, or two or more kinds can be used in combination. From the viewpoint of easily increasing the refractive index, among the vinyl monomers other than (meth)acrylate monomers that can copolymerize with (meth)acrylate monomers, styrene is particularly preferred.

[0084] (Organosiloxane rubber)

[0085] Examples of the above-mentioned siloxane rubber include: (i) organosiloxane polymers composed of dialkyl or diaryl disubstituted siloxaneoxy units such as dimethylsiloxaneoxy, diethylsiloxaneoxy, methylphenylsiloxaneoxy, diphenylsiloxaneoxy, dimethylsiloxaneoxy-diphenylsiloxaneoxy; (ii) organohydrogensiloxaneoxy and other organosiloxane polymers composed of alkyl or aryl monosubstituted siloxaneoxy units in which a part of the alkyl side chain is substituted by a hydrogen atom.

[0086] These organosiloxane rubbers can be used alone or in combination of two or more. From the viewpoint of imparting heat resistance to the cured product, among these siloxane rubbers, dimethylsiloxaneoxy, methylphenylsiloxaneoxy, and dimethylsiloxaneoxy-diphenylsiloxaneoxy are preferred, and dimethylsiloxaneoxy is most preferred from the viewpoint of easy availability.

[0087] In this specification, a polymer composed of dimethylsiloxaneoxy units is called dimethylsiloxaneoxy rubber, a polymer composed of methylphenylsiloxaneoxy units is called methylphenylsiloxaneoxy rubber, and a polymer composed of dimethylsiloxaneoxy units and diphenylsiloxaneoxy units is called dimethylsiloxaneoxy-diphenylsiloxaneoxy rubber.

[0088] As the organosiloxane rubber, (i) from the viewpoint of providing a molded article or cured product with excellent heat resistance for the obtained resin composition containing powder particles, one or more selected from dimethylsiloxaneoxy rubber, methylphenylsiloxaneoxy rubber, and dimethylsiloxaneoxy-diphenylsiloxaneoxy rubber are preferred; (ii) from the viewpoint of being easily obtainable and having good economy, dimethylsiloxaneoxy rubber is more preferred. In order to improve the toughness of the obtained cured product, the glass transition temperature (hereinafter sometimes simply referred to as "Tg") of the core layer is preferably 0°C or lower, more preferably -20°C or lower, further preferably -40°C or lower, and particularly preferably -60°C or lower.

[0089] In addition, the volume-average particle diameter of the core layer is not particularly limited, and is preferably 0.03 μm to 2 μm, more preferably 0.05 μm to 1 μm, still more preferably 0.12 μm to 0.50 μm, still more preferably 0.12 μm to 0.28 μm, and further preferably 0.14 to 0.25 μm. When the volume-average particle diameter of the core layer is within this range, the core layer can be stably produced, and the heat resistance and impact resistance of the cured product can be improved. The method for measuring the volume-average particle diameter of the core layer will be described in detail in the examples below.

[0090] The core layer may have a single-layer structure or a multilayer structure formed of layers having rubber elasticity. In addition, when the core layer has a multilayer structure, the polymer compositions of the respective layers may be different from each other within the ranges disclosed above.

[0091] In one embodiment of the present invention, an intermediate layer as described in paragraphs

[0046] to

[0049] of WO2016-163491 can be provided between the core layer and the shell layer.

[0092] 《Shell layer》

[0093] The shell layer is a polymer obtained by polymerizing monomers for forming the shell layer. The polymer (shell polymer) constituting the shell layer is used to improve the compatibility between the polymer particles (B) and the component (A), and can disperse the polymer particles (B) in the composition and / or the cured product of the composition in the state of primary particles.

[0094] The composition of the monomers for forming the shell layer, that is, the types and content ratios of the monomers contained in the monomers for forming the shell layer are not particularly limited. As the monomers for forming the shell layer, from the viewpoints of the compatibility and dispersibility of the polymer particles (B) in the composition, for example, aromatic vinyl-based monomers, acrylonitrile-based monomers, or (meth)acrylate-based monomers are preferred, and (meth)acrylate-based monomers are more preferred. In particular, the monomers for forming the shell layer preferably contain methyl methacrylate. These monomers for forming the shell layer may be used alone or in combination of two or more.

[0095] In other words, the types and content ratios of the structural units contained in the shell layer are not particularly limited. From the viewpoints of the compatibility and dispersibility of the polymer particles (B) in the composition, the shell layer preferably contains structural units derived from one or more monomers selected from aromatic vinyl-based monomers, acrylonitrile-based monomers, and (meth)acrylate-based monomers, and more preferably contains structural units derived from (meth)acrylate-based monomers. In particular, the shell layer preferably contains structural units derived from methyl methacrylate.

[0096] Regarding the shell layer, the total content of structural units derived from one or more monomers selected from aromatic vinyl monomers, acrylonitrile monomers, and (meth)acrylate monomers preferably contains 10.0% to 99.5% by mass of the shell layer (shell polymer), more preferably 50.0% to 99.0% by mass, still more preferably 65.0% to 98.0% by mass, particularly preferably 67.0% to 80.0% by mass, and most preferably 67.0% to 85.0% by mass.

[0097] Specific examples of the above aromatic vinyl monomers include vinylbenzenes such as styrene, α-methylstyrene, p-methylstyrene, and divinylbenzene.

[0098] Specific examples of the above acrylonitrile monomers include acrylonitrile or methacrylonitrile.

[0099] Specific examples of the (meth)acrylate monomers are the same as those described in the above "Core Layer" section, so the relevant descriptions are incorporated by reference and the explanations are omitted here.

[0100] In order to prevent the polymer particles (B) from aggregating and maintain a good dispersion state in the cured product and the composition, from the perspective of chemically bonding the polymer particles (B) and the component (A), the shell layer preferably has a structural unit derived from a monomer containing a reactive group. In other words, the shell layer preferably contains a reactive group.

[0101] As the reactive group, it is preferably selected from, for example, one or more of an epoxy group, an oxetanyl group, a hydroxyl group, an amino group, an imide group, a carboxylic acid group, a carboxylic anhydride group, a cyclic ester, a cyclic amide, a benz oxazinyl group, and a cyanate ester group.

[0102] Since the obtained cured product has excellent adhesive strength and impact-resistant peel adhesion, the reactive group is preferably an epoxy group. In other words, the shell layer preferably has a structural unit derived from a monomer having an epoxy group, that is, it preferably has an epoxy group.

[0103] Specific examples of the monomer having the above epoxy group include glycidyl (meth)acrylate, glycidyl ether of 4-hydroxybutyl (meth)acrylate, and vinyl monomers containing a glycidyl group such as allyl glycidyl ether.

[0104] For the present disclosure, in the compositions that at least satisfy the above (3), for example, in each of composition (III), composition (I)+(III), composition (II)+(III), and composition (I)+(II)+(III), it is indispensable that the shell layer of the polymer particles (B) has an epoxy group. In composition (III), composition (I)+(III), composition (II)+(III), and composition (I)+(II)+(III), since the shell layer of the polymer particles (B) has an epoxy group, composition (III), composition (I)+(III), composition (II)+(III), and composition (I)+(II)+(III) have the advantage of being able to provide a cured product having excellent adhesive strength through low-temperature curing. In addition, in composition (III), composition (I)+(III), composition (II)+(III), and composition (I)+(II)+(III), the epoxy group in the shell layer also helps composition (III), composition (I)+(III), composition (II)+(III), and composition (I)+(II)+(III) to provide a cured product having excellent impact peel adhesion through low-temperature curing.

[0105] In addition, for the present disclosure, it is not necessary for the shell layer of the polymer particles (B) in each of composition (I), (II), and composition (I)+(II) to have an epoxy group, but it is optional. For the present disclosure, in composition (I), composition (II), and composition (I)+(II), the shell layer of the polymer particles (B) may or may not have an epoxy group. In composition (I), (II), and composition (I)+(II), when the shell layer of the respective polymer particles (B) has an epoxy group, composition (I), (II), and composition (I)+(II) can each provide a cured product having excellent adhesive strength through low-temperature curing, and in addition, can also provide a cured product having excellent impact peel adhesion through low-temperature curing.

[0106] In the case where the shell layer of the polymer particles (B) has an epoxy group, from the viewpoints of the adhesive strength and impact peel adhesion of the obtained cured product, and the storage stability of the composition, the epoxy group content of the above shell layer is preferably more than 0 mmol / g and 2.0 mmol / g or less, more preferably 0.1 mmol / g or more and 2.0 mmol / g or less, and still more preferably 0.3 mmol / g or more and 1.5 mmol / g or less, relative to the total mass of the shell layer of the polymer particles (B). According to this configuration, it is speculated that the aggregation of the polymer particles (B) can be suppressed, and the polymer particles (B) can be dispersed in the cured product in the state of primary particles. As a result, the adhesive strength and impact peel adhesion of the cured product can be improved.

[0107] Monomers having an epoxy group are preferably used for forming the shell layer, and more preferably used only for forming the shell layer. In other words, the core layer and the intermediate layer preferably do not have an epoxy group.

[0108] It can be considered that the less the amount of epoxy groups in the shell layer of the polymer particles (B), the more excellent the storage stability of the composition. In other words, from the viewpoint of the storage stability of the composition, for example, in the compositions (I), (II), and the composition (I)+(II), the shell layer of the polymer particles (B) preferably does not have an epoxy group.

[0109] As a specific example of the monomer having a hydroxyl group as the above-mentioned monomer containing a reactive group, for example, the above-mentioned (meth)acrylic acid hydroxyalkyl esters can be cited.

[0110] When the shell layer contains a structural unit derived from a polyfunctional monomer having two or more radically polymerizable double bonds, swelling of the polymer particles (B) in the composition can be prevented, and in addition, the viscosity of the composition tends to decrease and the workability tends to improve, so it is preferred. On the other hand, from the viewpoints of the effect of improving the toughness of the obtained cured product and the effect of improving the impact-resistant peel adhesiveness, the shell layer preferably does not contain a structural unit derived from a polyfunctional monomer having two or more radically polymerizable double bonds.

[0111] As specific examples of the above-mentioned polyfunctional monomers, excluding conjugated diene monomers such as butadiene, (meth)allyl acrylate, (meth)allyl alkyl acrylates such as (meth)allyl alkyl acrylate; (meth)allyloxyalkyl acrylates; poly(ethylene glycol) di(meth)acrylate, butanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate and other polyfunctional (meth)acrylates having two or more (meth)acryloyl groups; diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, divinylbenzene and the like.

[0112] Among these polyfunctional monomers, allyl methacrylate and triallyl isocyanurate are preferred.

[0113] The shell layer is preferably a polymer containing only structural units such as the following: (a) 0 mass% to 50 mass% (preferably 1 mass% to 50 mass%, more preferably 2 mass% to 48 mass%) of structural units derived from aromatic vinyl monomers (particularly preferably styrene); (b) 0 mass% to 50 mass% (preferably 0 mass% to 30 mass%, more preferably 10 mass% to 25 mass%) of structural units derived from acrylonitrile monomers (particularly preferably acrylonitrile); (c) 0 mass% to 100 mass% (preferably 5 mass% to 100 mass%, more preferably 70 mass% to 95 mass%) of structural units derived from (meth)acrylate monomers ((i) preferably selected from at least one monomer among methyl acrylate, butyl acrylate, and methyl methacrylate; (ii) particularly preferably methyl methacrylate); and (d) 1 mass% to 50 mass% (preferably 2 mass% to 35 mass%, more preferably 3 mass% to 20 mass%) of structural units derived from monomers having an epoxy group (particularly glycidyl methacrylate). Among them, (i) the sum of the structural units derived from aromatic vinyl monomers, the structural units derived from acrylonitrile monomers, the structural units derived from (meth)acrylate monomers, and the structural units derived from monomers having an epoxy group is 100 mass%, and (ii) 0 mass% means that this structural unit may not be included.

[0114] The above monomer components can be used alone or in combination of two or more. The shell layer may contain structural units derived from monomers other than the above monomers.

[0115] The shell layer can be a single-layer structure or a multi-layer structure. In addition, when the shell layer is a multi-layer structure, the polymer compositions of each layer can be different from each other within the scope disclosed above.

[0116] 《Volume average particle diameter (Mv) of polymer particles (B)》

[0117] The volume average particle diameter (Mv) of the polymer particles (B) is not particularly limited. From the viewpoints of industrial productivity and the workability of the curable resin composition, it is preferably 0.01 μm or more and 2.00 μm or less, more preferably 0.03 μm or more and 0.60 μm or less, more preferably 0.05 μm or more and 0.40 μm or less, more preferably 0.10 μm or more and 0.30 μm or less, more preferably 0.15 μm or more and 0.30 μm or less, more preferably 0.16 μm or more and 0.28 μm or less, more preferably 0.17 μm or more and 0.27 μm or less, and still more preferably 0.18 μm or more and 0.25 μm or less. When the volume average particle diameter (Mv) of the polymer particles (B) is: (a) 0.01 μm or more, the viscosity of the curable resin composition becomes low, and thus the workability becomes good; (b) 2.00 μm or less, the polymerization time of the component (B) becomes short, and the industrial productivity becomes high. The method for measuring the volume average particle diameter (Mv) of the polymer particles (B) will be described in detail in the examples described later.

[0118] The polymer particles (B) are preferably dispersed in the composition in the state of primary particles. "The polymer particles (B) are dispersed in the state of primary particles" (hereinafter, also simply referred to as primary dispersion) in this specification means that the polymer particles (B) are actually dispersed independently of each other (without contact), and its dispersion state can be confirmed by the following method: for example, a part of the composition is dissolved in a solvent such as methyl ethyl ketone, and it is subjected to a laser scattering particle size measuring device or the like to measure the particle size of the polymer particles (B) in the composition.

[0119] In addition, "stable dispersion" of the polymer particles (B) means a state in which the polymer particles (B) do not aggregate, separate, or precipitate in the continuous layer, but are dispersed under constant normal conditions for a long period of time. In addition, it is preferably such that there is no substantial change in the distribution of the polymer particles (B) in the continuous layer, and even if these compositions are heated within a non-hazardous range to reduce the viscosity and stirred, "stable dispersion" can be maintained.

[0120] The polymer particles (B) may be used alone or in combination of two or more.

[0121] <Manufacturing method of core-shell polymer particles>

[0122] (Manufacturing method of the core layer)

[0123] The formation of the core layer of the polymer particles (B) can be produced by, for example, emulsion polymerization method, suspension polymerization method, mini-suspension polymerization method, etc. As methods such as emulsion polymerization method, suspension polymerization method, mini-suspension polymerization method, etc., the methods described in, for example, International Publication No. 2005 / 028546 and International Publication 2006 / 070664 can be appropriately used.

[0124] (Method for forming the shell layer and the intermediate layer)

[0125] The intermediate layer can be formed by polymerizing the monomer for forming the intermediate layer by using a known radical polymerization. In the case where the rubber elastomer constituting the core layer is obtained in the form of an emulsion, the polymerization of the monomer for forming the intermediate layer is preferably carried out by the emulsion polymerization method.

[0126] The shell layer can be formed by polymerizing the monomer for forming the shell layer by a known radical polymerization. In the case where the core layer is obtained in the form of an emulsion, or the polymer particle precursor formed by coating the core layer with the intermediate layer, the polymerization of the monomer for forming the shell layer is preferably carried out by the emulsion polymerization method. As the emulsion polymerization method, the method described in International Publication No. 2005 / 028546 can be appropriately used, for example.

[0127] An emulsifier (dispersant) is used in the emulsion polymerization.

[0128] Examples of the emulsifier include: (i)(i-1) alkyl or aryl sulfonic acids represented by dioctyl sulfosuccinic acid and dodecylbenzenesulfonic acid; alkyl or aryl ether sulfonic acids; alkyl or aryl sulfates represented by dodecyl sulfate; alkyl or aryl ether sulfates; alkyl or aryl substituted phosphates; alkyl or aryl ether substituted phosphates; N-alkyl or aryl sarcosines represented by dodecyl sarcosine; oleic acid and alkyl or aryl carboxylic acids represented by stearic acid, etc.; alkyl or aryl ether carboxylic acids; and other various acids, and (i-2) anionic emulsifiers (dispersants) such as alkali metal salts or ammonium salts of these acids; (ii) nonionic emulsifiers (dispersants) such as alkyl or aryl substituted polyethylene glycols; (iii) dispersants such as polyvinyl alcohol, alkyl substituted cellulose, polyvinylpyrrolidone, and polyacrylic acid derivatives.

[0129] These emulsifiers (dispersants) can be used alone or in combination of two or more.

[0130] As long as it does not affect the dispersion stability of the aqueous latex of the polymer particles, it is preferable to reduce the usage amount of the emulsifier (dispersant). In addition, the higher the water solubility of the emulsifier (dispersant), the more preferable. When the water solubility is high, the washing and removal of the emulsifier (dispersant) become easy, and it is possible to easily prevent adverse effects on the finally obtained cured product.

[0131] In the case of using emulsion polymerization, peroxides (e.g., organic peroxides), chain transfer agents, surfactants, etc. can be used as needed.

[0132] Polymerization temperature, pressure, deoxidation and other conditions during polymerization can be applied within a known range.

[0133] From the perspective of excellent balance between the storage stability of the obtained composition and the toughness improvement effect of the obtained cured product, the content of polymer particles (B) in the present composition is preferably 1 to 100 parts by mass, more preferably 5 to 90 parts by mass, further preferably 10 to 80 parts by mass, still more preferably 20 to 70 parts by mass, and particularly preferably 30 to 60 parts by mass, based on 100 parts by mass of epoxy resin (A).

[0134] <Dicyandiamide (C)>

[0135] Dicyandiamide (C) can function as a curing agent for curing the composition. Dicyandiamide (C) does not exert a curing effect at least at a temperature below 100 °C, or even if it exerts a curing effect, the curing reaction proceeds very slowly. On the other hand, when heated to a temperature above 100 °C (preferably 120 °C), dicyandiamide (C) exerts a curing effect, enabling the composition to be cured rapidly.

[0136] As described above, component (C) does not exert a curing effect at a temperature around room temperature, or even if it exerts a curing effect, the curing reaction proceeds very slowly. Therefore, although the present composition is a one-component thermosetting composition, there is no risk of accidental curing during storage of the present composition. In other words, it can be considered that the present composition has excellent storage stability by containing component (C) as a curing agent.

[0137] Based on 100 parts by mass of epoxy resin (A), the present composition contains 3.5 to 19.0 parts by mass of component (C), preferably 3.5 to 18.0 parts by mass, more preferably 4.0 to 16.0 parts by mass, more preferably 4.5 to 14.0 parts by mass, further contains 5.0 to 12.0 parts by mass, still further contains 5.5 to 10.0 parts by mass, and particularly preferably 6.0 to 8.0 parts by mass. Based on 100 parts by mass of epoxy resin (A), when the content of component (C) is (a) 3.5 parts by mass or more, there is an advantage that the cured product obtained by curing the present composition at a low temperature has sufficient adhesive strength; (b) 19.0 parts by mass or less, the present composition has an advantage that the storage stability becomes good.

[0138] <Amine adduct curing agent (D)>

[0139] The amine adduct curing agent (D) can function as a curing agent for curing the composition. The amine adduct curing agent (D) is a compound that functions as a curing agent for the epoxy resin (A). This curing agent is a solid that is insoluble in the epoxy resin (A) at room temperature (e.g., 25 °C) and is soluble in the epoxy resin (A) by heating. Although the amine adduct curing agent (D) is a latent curing agent, more specifically, it can also be said to be a potential modified polyamine-based curing agent that is solid at room temperature.

[0140] The amine adduct curing agent (D) does not exhibit a curing effect at least at temperatures below 80 °C, or even if it exhibits a curing effect, the curing reaction proceeds very slowly. On the other hand, the amine adduct curing agent (D) can exhibit a curing effect when heated to a temperature of 80 °C or higher (preferably 120 °C), thereby curing the composition rapidly.

[0141] As described above, the component (D) does not exhibit a curing effect at a temperature around room temperature, or even if it exhibits a curing effect, the curing reaction proceeds very slowly. Therefore, although this composition is a one-component thermosetting composition, there is no risk of accidental curing during storage of this composition. In other words, it can be considered that this composition has excellent storage stability by containing the component (D) as a curing agent.

[0142] Examples of the amine adduct curing agent (D) include: for example, an amine-epoxy adduct curing agent that is a reaction product of an amine compound and an epoxy compound (e.g., AM ICURE PN23, PN31, PN40, PN50, PN-H manufactured by Ajinomoto Fine-Techno Co., Inc.; AJ ICURE PN23, PN31, PN40, PN50, PN-H manufactured by Ajinomoto Fine-Techno Co., Inc.; Hardner X-3661S, X-3670S manufactured by Aiming Relations Contribut ion Co., Ltd.; NOVACURE HX-3742, HX-3721 manufactured by Asahi Kasei Corporation; ADEKAHARDENER EH3293S, EH3366S, EH4346S manufactured by ADEKA Corporation; etc.), a urea-type adduct curing agent that is a reaction product of an amine compound and an isocyanate compound or a urea compound (e.g., FUJICURE-FXR-1020, FXR-1121, FXR-1081, 1061, 1171 manufactured by T&K TOKA (Fuji Kasei Kogyo Co., Ltd.); etc.). There are also cases where the amine-epoxy adduct curing agent is referred to as an epoxy compound adduct curing agent.

[0143] From the viewpoints that the composition has excellent rapid curability at low temperatures and the cured product obtained by curing has excellent heat resistance, the amine adduct curing agent (D) preferably contains one or more selected from amine-epoxy adduct curing agents and urea adduct curing agents, and particularly preferably contains one or more selected from amine-epoxy adduct curing agents.

[0144] In 100% by mass of the amine adduct curing agent (D), the amine adduct curing agent (D) preferably contains 70% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more of one or more selected from amine-epoxy adduct curing agents.

[0145] The amine adduct curing agent (D) may be composed of only one or more selected from amine-epoxy adduct curing agents and urea adduct curing agents, may be composed of one or more selected from urea adduct curing agents, or may be composed of only one or more selected from amine-epoxy adduct curing agents.

[0146] In the process of intensive research, the present inventors independently obtained the following new insights: The softening temperature and particle size of the amine adduct curing agent (D) may affect the adhesive strength of the cured product and the storage stability of the composition.

[0147] The amine adduct curing agent (D) preferably contains an amine adduct curing agent having a softening temperature of 80°C to 140°C. Based on this configuration, it has the advantage of excellent balance between the adhesive strength and storage stability of the cured product. Examples of the amine adduct curing agent having a softening temperature of 80°C to 140°C include: (i) Amicure PN-23 (95°C), Amicure PN-23J (95°C), Amicure PN-H (102°C), Amicure PN-40 (108°C), Amicure PN-40J (106°C), Amicure PN-31J (109°C), Amicure PN-50 (115°C), Amicure MY-24 (120°C), Ajicure PN-23 (95°C), Ajicure PN-23J (95°C), Ajicure PN-H (102°C), Ajicure PN-40 (108°C), Ajicure PN-40J (106°C), Ajicure PN-31J (109°C), Ajicure PN-50 (115°C), and Ajicure MY-24 (120°C) manufactured by Ajinomoto Fine-Techno Co., Inc., and (ii) FUJICURE-FXR-1020 (120°C to 130°C), FUJICURE-FXR-1081 (115°C to 125°C), FUJICURE-1061 (90°C to 110°C), FUJICURE-FXR-1121 (128°C to 138°C), and FUJICURE-1171 (105°C to 115°C) manufactured by T&K TOKA (Fuji Chemical Industry Co., Ltd.) (the temperatures in parentheses refer to the softening temperatures).

[0148] In 100% by mass of the amine adduct curing agent (D), the amine adduct curing agent (D) preferably contains 70% by mass or more of an amine adduct curing agent having a softening temperature of 80°C to 140°C, more preferably 80% by mass or more, and particularly preferably 90% by mass or more. In 100% by mass of the amine adduct curing agent (D), the amine adduct curing agent (D) may contain 100% by mass of an amine adduct curing agent having a softening temperature of 80°C to 140°C. In other words, it may be composed only of an amine adduct curing agent having a softening temperature of 80°C to 140°C.

[0149] From the perspective of more excellent balance between the adhesive strength and storage stability of the cured product, the softening temperature of the amine adduct curing agent contained in the amine adduct curing agent (D) is more preferably 90°C to 130°C, further preferably 100°C to 125°C, and particularly preferably 105°C to 120°C.

[0150] The amine adduct curing agent (D) preferably contains an amine adduct curing agent having a volume average particle diameter of 1 μm to 50 μm. Based on this configuration, there is an advantage that the balance between the adhesive strength and storage stability of the cured product is excellent. Here, the "volume average particle diameter" of the amine adduct curing agent refers to the particle diameter when the cumulative volume is 50% when the particle diameters of the amine adduct curing agent measured on a volume basis using the laser diffraction method are cumulatively arranged from the smaller particle diameter.

[0151] In 100% by mass of the amine adduct curing agent (D), the amine adduct curing agent (D) preferably contains 70% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more of an amine adduct curing agent having a volume average particle diameter of 1 μm to 50 μm. In 100% by mass of the amine adduct curing agent (D), the amine adduct curing agent (D) may contain 100% by mass of an amine adduct curing agent having a volume average particle diameter of 1 μm to 50 μm, in other words, it may be composed only of an amine adduct curing agent having a volume average particle diameter of 1 μm to 50 μm.

[0152] From the viewpoint of further excellent balance between the adhesive strength and storage stability of the cured product, the volume average particle diameter of the amine adduct curing agent contained in the amine adduct curing agent (D) is more preferably 3 μm to 30 μm, further preferably 4 μm to 25 μm, and particularly preferably 5 μm to 20 μm.

[0153] With respect to 100 parts by mass of the epoxy resin (A), this composition contains 0.3 part by mass to 10.0 parts by mass of the component (D). When the content of the component (D) in this composition is (a) 0.3 part by mass or more with respect to 100 parts by mass of the epoxy resin (A), there is an advantage that the cured product obtained by curing this composition at a low temperature has sufficient adhesive strength; when it is (b) 10.0 parts by mass or less, there is an advantage that the storage stability of this composition becomes good.

[0154] For the present disclosure, with respect to 100 parts by mass of the epoxy resin (A), one or more compositions selected from Composition (I), Composition (I)+(II), Composition (I)+(III), and Composition (I)+(II)+(III) preferably contain 0.3 parts by mass to 3.5 parts by mass of Component (D), more preferably 0.4 parts by mass to 2.8 parts by mass, still more preferably 0.4 parts by mass to 2.3 parts by mass, and particularly preferably 0.5 parts by mass to 1.8 parts by mass. On the other hand, for the present disclosure, with respect to 100 parts by mass of the epoxy resin (A), one or more compositions selected from Composition (II), Composition (III), and Composition (II)+(III) preferably contain 0.5 parts by mass to 9.0 parts by mass of Component (D), more preferably 0.6 parts by mass to 8.0 parts by mass, still more preferably 0.8 parts by mass to 7.0 parts by mass, and particularly preferably 1.0 parts by mass to 6.0 parts by mass.

[0155] This composition may contain a curing agent other than Component (C) and Component (D). For example, this composition may contain a latent curing agent other than Component (C) and Component (D). As the latent curing agent other than Component (C) and Component (D), examples thereof include N-containing curing agents such as specific amine-based curing agents (including imine-based curing agents). As the N-containing curing agent other than Component (C) and Component (D), examples include: boron trichloride / amine complex, boron trifluoride / amine complex, melamine, diallyl melamine, guanamine, aminotriazole, hydrazide, cyanoacetamide, imidazole, and aromatic polyamines.

[0156] From the viewpoint that the balance between the adhesive strength and storage stability of the cured product is particularly excellent, for this composition, in 100% by mass of the composition, the content of the curing agent other than Component (C) and Component (D) is preferably 5.0% by mass or less, more preferably 2.0% by mass or less, still more preferably 1.0% by mass or less, and particularly preferably 0.5% by mass or less. In this composition, the curing agent may consist only of Component (C) and Component (D).

[0157] <Urea compound (E)>

[0158] As the urea compound, a substance (compound) that preferably contains a urea bond in the molecule and can promote the curing of the composition is preferred. The urea compound (E) may also be referred to as a curing accelerator.

[0159] In the present disclosure, compositions that satisfy at least the above (1), such as composition (I), composition (I)+(II), composition (I)+(III), and composition (I)+(II)+(III), contain the urea compound (E) as an essential component. In composition (II), composition (III), and composition (II)+(III), the urea compound (E) is an optional component. Composition (II), composition (III), and composition (II)+(III) may each contain the urea compound (E).

[0160] The urea compound (E) is represented by the general formula (X):

[0161] R 1 -NH-C(=O)-N-R 2 2…(X)

[0162] (In the formula, R 1 is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, and two Rs 2 are each independently a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms.).

[0163] It should be noted that in this specification, amine adduct curing agents such as urea adduct curing agents are included in component (D) and not in the urea compound (E).

[0164] Examples of the urea compound (E) include one or more selected from 3-(3,4-dichlorophenyl)-1,1-dimethylurea (e.g., Dyhard UR200 manufactured by AlzChem), 3,3’-[methylenebis(4,1-phenylene)]bis(1,1-dimethylurea) (e.g., Omicure 52 manufactured by Huntsman), 1,1’-(4-methyl-1,3-phenylene)bis(3,3-dimethylurea) (e.g., Dyhard UR500 manufactured by AlzChem), 4,4’-methylenebis(phenyl dimethylurea), p-chlorophenyl-N,N-dimethylurea (e.g., trade name: Monuron), N-(3-chloro-4-methylphenyl)-N’,N’-dimethylurea (e.g., trade name: Chlortoluron), 1,1-dimethylphenylurea (e.g., Dyhard UR300 manufactured by Alz Chem), etc.

[0165] The urea compound (E) preferably contains one or more selected from 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3,3'-[methylenebis(4,1-phenylene)]bis(1,1-dimethylurea), and 1,1'-(4-methyl-1,3-phenylene)bis(3,3-dimethylurea), more preferably contains 3-(3,4-dichlorophenyl)-1,1-dimethylurea and / or 3,3'-[methylenebis(4,1-phenylene)]bis(1,1-dimethylurea), and particularly preferably contains 3-(3,4-dichlorophenyl)-1,1-dimethylurea. Based on this composition, it has the advantage of excellent balance between the adhesive strength and storage stability of the cured product.

[0166] In 100% by mass of the urea compound (E), the urea compound (E) preferably contains 70% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more of one or more selected from 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3,3'-[methylenebis(4,1-phenylene)]bis(1,1-dimethylurea), and 1,1'-(4-methyl-1,3-phenylene)bis(3,3-dimethylurea). In 100% by mass of the urea compound (E), the urea compound (E) may also contain 100% by mass of one or more selected from 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3,3'-[methylenebis(4,1-phenylene)]bis(1,1-dimethylurea), and 1,1'-(4-methyl-1,3-phenylene)bis(3,3-dimethylurea). In other words, it may be composed of only one or more selected from 3-(3,4-dichlorophenyl)-1,1-dimethylurea, 3,3'-[methylenebis(4,1-phenylene)]bis(1,1-dimethylurea), and 1,1'-(4-methyl-1,3-phenylene)bis(3,3-dimethylurea). Further, the urea compound (E) may also be composed of only 3-(3,4-dichlorophenyl)-1,1-dimethylurea and / or 3,3'-[methylenebis(4,1-phenylene)]bis(1,1-dimethylurea), or may be composed of only 3-(3,4-dichlorophenyl)-1,1-dimethylurea.

[0167] Per 100 parts by mass of the epoxy resin (A), the composition (I) contains 0.5 to 15.0 parts by mass of the component (E). Per 100 parts by mass of the epoxy resin (A), this composition, such as the composition (I), the composition (I)+(II), the composition (I)+(III), and the composition (I)+(II)+(III), preferably contains 0.5 to 15.0 parts by mass of the component (E), more preferably 0.7 to 13.0 parts by mass, still more preferably 0.9 to 11.0 parts by mass, even more preferably 1.0 to 10.0 parts by mass, further preferably 1.2 to 9.0 parts by mass, still further preferably 1.4 to 7.0 parts by mass, and particularly preferably 1.5 to 6.0 parts by mass. When the content of the component (E) in this composition is (a) 0.5 parts by mass or more per 100 parts by mass of the epoxy resin (A), the cured product obtained by curing this composition at a low temperature has the advantage of sufficient adhesive strength; when (b) it is 15.0 parts by mass or less, this composition has the advantage of good storage stability.

[0168] Regarding this composition, per 100 parts by mass of the epoxy resin (A), the total content of the component (D) and the component (E) is preferably 0.8 to 25.0 parts by mass, more preferably 1.0 to 16.5 parts by mass, still more preferably 1.2 to 14.5 parts by mass, even more preferably 1.4 to 12.3 parts by mass, further preferably 1.5 to 11.3 parts by mass, still further preferably 1.6 to 9.8 parts by mass, and particularly preferably 1.8 to 7.8 parts by mass. When the total content of the component (D) and the component (E) in this composition is (a) 0.8 parts by mass or more per 100 parts by mass of the epoxy resin (A), the cured product obtained by curing this composition at a low temperature has the advantage of sufficient adhesive strength; when (b) it is 25.0 parts by mass or less, this composition has the advantage of good storage stability. In the process of painstaking research, the present inventors independently obtained the following insight: When the total content of the component (D) and the component (E) in this composition is 7.8 parts by mass or less per 100 parts by mass of the epoxy resin (A), the storage stability of this composition becomes particularly good.

[0169] This composition may contain a curing accelerator other than the component (E). Examples of the curing accelerator other than the component (E) include: tertiary amines, imidazoles, and 6-caprolactam, etc.

[0170] From the viewpoint of particularly excellent balance between the adhesive strength and storage stability of the cured product, in 100% by mass of the composition, the content of the curing accelerator other than the component (E) in this composition is preferably 5.0% by mass or less, more preferably 2.0% by mass or less, still more preferably 1.0% by mass or less, and particularly preferably 0.5% by mass or less. In this composition, the curing accelerator may consist only of the component (E).

[0171] <Epoxy reactive diluent (F)>

[0172] In this specification, the "epoxy reactive diluent" refers to a compound having an epoxy group and a viscosity of 500 mPa·s or less at 25°C.

[0173] In the present disclosure, at least the compositions satisfying the above (2), such as composition (II), composition (I)+(II), composition (II)+(III), and composition (I)+(II)+(III), contain the epoxy reactive diluent (F) as an essential component. For composition (I), composition (III), and composition (I)+(III), the epoxy reactive diluent (F) is an optional component. Composition (I), composition (III), and composition (I)+(III) may each contain the epoxy reactive diluent (F).

[0174] Examples of the epoxy reactive diluent (F) include: polyalkylene glycol diglycidyl ether, glycol diglycidyl ether, diglycidyl ester of aliphatic polybasic acid, glycidyl ether of polyhydric aliphatic alcohol having two or more hydroxyl groups, and monoepoxide.

[0175] More specifically, examples of the above polyalkylene glycol diglycidyl ether include: polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, etc. More specifically, examples of the above glycol diglycidyl ether include: neopentyl glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, etc. More specifically, examples of the above diglycidyl ester of aliphatic polybasic acid include: diglycidyl ester of dimer acid, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, maleic acid diglycidyl ester, etc. More specifically, examples of the above glycidyl ether of polyhydric aliphatic alcohol having two or more hydroxyl groups include: trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl ether, castor oil-modified polyglycidyl ether, propoxylated glycerol triglycidyl ether, sorbitol polyglycidyl ether, etc.

[0176] As the monocyclic epoxide, for example, the following can be cited: aliphatic glycidyl ethers such as butyl glycidyl ether; aromatic glycidyl ethers such as phenyl glycidyl ether and tolyl glycidyl ether (o-tolyl glycidyl ether); ethers formed from an alkyl group having 8 to 10 carbon atoms such as 2-ethylhexyl glycidyl ether and a glycidyl group; ethers formed from a phenyl group having 6 to 12 carbon atoms which may be substituted by an alkyl group having 2 to 8 carbon atoms such as p-tert-butylphenyl glycidyl ether and a glycidyl group; ethers formed from an alkyl group having 12 to 14 carbon atoms such as dodecyl glycidyl ether and a glycidyl group (alkyl C12-C14 glycidyl ether); aliphatic glycidyl esters such as glycidyl (meth)acrylate and glycidyl maleate; glycidyl esters of aliphatic carboxylic acids having 8 to 12 carbon atoms such as glycidyl 2-ethylhexanoate (Versatic acid), glycidyl neodecanoate, and glycidyl laurate; glycidyl p-tert-butylbenzoate, etc.

[0177] The epoxy-based reactive diluent (F) preferably contains an epoxy-based reactive diluent having 1 epoxy group in 1 molecule. Based on this constitution, there is an advantage that the cured product has excellent impact peel adhesiveness and the storage stability of the composition is more excellent. As the epoxy-based reactive diluent having 1 epoxy group in 1 molecule, the following can be cited: glycidyl neodecanoate, phenyl glycidyl ether, tolyl glycidyl ether, 4-tert-butylphenyl glycidyl ether, 2-ethylhexyl glycidyl ether, etc. In 100% by mass of the epoxy-based reactive diluent (F), the epoxy-based reactive diluent (F) preferably contains 70% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more of the epoxy-based reactive diluent having 1 epoxy group in 1 molecule. In 100% by mass of the epoxy-based reactive diluent (F), the epoxy-based reactive diluent (F) may contain 100% by mass of the epoxy-based reactive diluent having 1 epoxy group in 1 molecule, in other words, it may be composed only of the epoxy-based reactive diluent having 1 epoxy group in 1 molecule.

[0178] As the epoxy-based reactive diluent (F), commercially available products can also be used. Examples of commercially available products of the epoxy-based reactive diluent (F) include: YED216M (manufactured by Mitsubishi Chemical, 1,6-hexanediol diglycidyl ether), Cardura E10P (manufactured by Hexion, glycidyl neodecanoate), ERISYS GE-10 (manufactured by Huntsman, o-tolyl glycidyl ether), 4-tert-butylphenyl glycidyl ether (manufactured by Tokyo Chemical Industry), ERISYS GE-6 (manufactured by Huntsman, 2-ethylhexyl glycidyl ether), ERISYS GE-8 (manufactured by Huntsman, alkyl C12-C14 glycidyl ether), ERISYS GE-20 (manufactured by Huntsman, neopentyl glycol diglycidyl ether), ERISYS GE-21 (manufactured by Huntsman, 1,4-butanediol diglycidyl ether), and ERISYS GE-24 (manufactured by Huntsman, polypropylene glycol diglycidyl ether), etc. It should be noted that Cardura E10P, ERISYS GE-10, 4-tert-butylphenyl glycidyl ether, ERISYS GE-6, and ERISYS GE-8 are each an epoxy-based reactive diluent having 1 epoxy group in 1 molecule.

[0179] Per 100 parts by mass of the epoxy resin (A), the composition (II) contains 1.0 to 20.0 parts by mass of the component (F). This composition, for example, the composition (II), the composition (I)+(II), the composition (II)+(III), and the composition (I)+(II)+(III), per 100 parts by mass of the epoxy resin (A), preferably contains 1.0 to 20.0 parts by mass of the component (F), more preferably contains 2.0 to 18.0 parts by mass, still more preferably contains 4.0 to 16.0 parts by mass, further preferably contains 6.0 to 14.0 parts by mass, and particularly preferably contains 8.0 to 12.0 parts by mass. When the content of the component (F) in this composition is within the above range, it has the advantage that the cured product obtained by curing this composition at low temperature has sufficient adhesive strength.

[0180] The ratio (Wc / We) of the total mass Wc of dicyandiamide (C) to the total mass We of the above urea compound (E) is preferably 1.1 to 20.0, more preferably 1.1 to 10.0, still more preferably 1.2 to 5.0, and particularly preferably 1.2 to 3.0. Based on this constitution, it has the advantage that the adhesive strength of the cured product obtained by curing this composition at low temperature is more excellent.

[0181] The ratio (We / Wd) of the total mass We of the urea compound (E) to the total mass Wd of the above amine adduct curing agent (D) is preferably from 1.1 to 20.0, more preferably from 1.5 to 15.0, still more preferably from 2.0 to 10.0, and particularly preferably from 2.5 to 5.0. Based on this configuration, there is an advantage that the adhesive strength of the cured product obtained by curing the present composition at a low temperature is more excellent. In addition, during the intensive research, the present inventors independently found the following surprising insights: when the ratio of We to Wd is within the above range, the impact-resistant peel adhesiveness is high, and the shear rate dependence of the viscosity becomes large. In the past, the technical idea of using the amine adduct curing agent (D) and the urea compound (E) in combination was not known, and therefore the above insights cannot be predicted from the prior art.

[0182] <Inorganic filler>

[0183] The present composition preferably contains an inorganic filler. By containing an inorganic filler in the present composition, the following effects are obtained: the cured product obtained has more excellent rigidity at high temperatures.

[0184] Examples of the inorganic filler include: silicas and / or silicates such as dry silica, wet silica, aluminum silicate, magnesium silicate, and calcium silicate; reinforcing fillers such as wollastonite, talc, dolomite, and carbon black; heavy calcium carbonate, colloidal calcium carbonate, magnesium carbonate, titanium oxide, iron oxide, aluminum fine powder, zinc oxide, activated zinc oxide, and the like.

[0185] Among them, wollastonite is preferred in view of the advantage that the cured product obtained has further excellent rigidity at high temperatures. As the inorganic filler, fumed silica and calcium carbonate are also preferred. One kind of the above inorganic fillers can be used alone, or two or more kinds can be used in combination.

[0186] The above dry silica is also called fumed silica, and examples thereof include hydrophilic fumed silica with an untreated surface and hydrophobic fumed silica produced by chemically treating the silanol group portion of hydrophilic fumed silica with silane or siloxane. From the viewpoint of dispersibility in the epoxy resin (A), hydrophobic fumed silica is preferred.

[0187] The inorganic filler is preferably surface-treated with a surface treatment agent. By the surface treatment, the dispersibility of the inorganic filler in the composition is improved, and as a result, various physical properties of the obtained cured product are improved.

[0188] Based on 100 parts by mass of the epoxy resin (A), the content of the inorganic filler in the present composition is preferably 1 to 300 parts by mass, more preferably 5 to 200 parts by mass, and still more preferably 10 to 150 parts by mass. When the content of the inorganic filler is within the above range, the cured product obtained has the advantage of further excellent rigidity and adhesive strength at high temperatures.

[0189] It should be noted that in this specification, the calcium oxide described later is not included in the inorganic filler. That is, when the present composition contains an inorganic filler and calcium oxide, the amount of the above calcium oxide is not counted in the content of the inorganic filler.

[0190] <Calcium Oxide>

[0191] The present composition preferably contains calcium oxide. When the present composition contains calcium oxide, the calcium oxide reacts with the moisture in the composition to remove the moisture from the composition, solving various problems in physical properties caused by the presence of moisture. For example, calcium oxide can function as an anti-bubble agent based on moisture removal, thereby suppressing a decrease in the adhesive strength of the obtained cured product.

[0192] The calcium oxide can be surface-treated with a surface treatment agent. By the surface treatment, the dispersibility of the calcium oxide in the composition can be improved. As a result, the physical properties such as the adhesive strength of the obtained cured product are improved compared with the case of using calcium oxide without surface treatment. The above surface treatment agent is not particularly limited, and a fatty acid is preferred.

[0193] Calcium oxide can be used alone as one kind, or two or more kinds can be used in combination. In addition, surface-treated calcium oxide and non-surface-treated calcium oxide can be used in combination.

[0194] Based on 100 parts by mass of the epoxy resin (A), the content of the calcium oxide in the present composition is preferably 0.1 to 10.0 parts by mass, more preferably 0.2 to 5.0 parts by mass, still more preferably 0.5 to 3.0 parts by mass, and particularly preferably 1.0 to 2.0 parts by mass. When the content of the calcium oxide in the present composition is 0.1 part by mass or more, the moisture removal effect is good, and when it is 10.0 parts by mass or less, the strength of the obtained cured product is high.

[0195] <Other Components>

[0196] As needed, the present composition may contain other components. Examples of other components include: phenolic compounds, blocked urethanes, reinforcing agents, free-radical curable resins, monoepoxides, photoinitiators, azo chemical blowing agents, expanding agents such as thermally expandable microspheres, fiber slurries such as polyaramide-based slurries, coloring agents such as pigments and dyes, extender pigments, ultraviolet absorbers, antioxidants, stabilizers (anti-gelation agents), plasticizers, leveling agents, defoaming agents, silane coupling agents, antistatic agents, flame retardants, lubricants, viscosity reducers, low shrinkage agents, organic fillers, thermoplastic resins, desiccants, dispersants, etc.

[0197] (Blocked urethane)

[0198] The present composition may contain a blocked urethane as needed. As the blocked urethane, for example, the compounds described in paragraphs

[0079] to

[0107] of WO2016-163491 can be used.

[0199] <DSC parameters>

[0200] In the DSC curve of the above-mentioned single-component thermosetting resin composition measured by a differential scanning calorimeter under the condition of a heating rate of 10°C / min, the exothermic onset temperature of the present composition is 80°C or higher, and the exothermic peak temperature is 150°C or lower.

[0201] It is considered that the higher the exothermic onset temperature of the composition, the better the storage stability of the composition. The above-mentioned exothermic onset temperature of the present composition is preferably 80°C or higher, more preferably 85°C or higher, more preferably 90°C or higher, more preferably 92°C or higher, more preferably 95°C or higher, further preferably 97°C or higher, and particularly preferably 100°C or higher. It is considered that the lower the exothermic onset temperature of the composition, the lower the temperature at which the composition can be cured. The upper limit value of the exothermic onset temperature of the present composition is not particularly limited. The above-mentioned exothermic onset temperature of the present composition is preferably 135°C or lower, more preferably 130°C or lower, more preferably 125°C or lower, more preferably 120°C or lower, more preferably 115°C or lower, more preferably 113°C or lower, further preferably 112°C or lower, and particularly preferably 110°C or lower.

[0202] It can be considered that the lower the exothermic peak temperature of the composition, the more likely it is to cure at a low temperature. The above-mentioned exothermic peak temperature of this composition is preferably 150 °C or lower, more preferably 147 °C or lower, further preferably 145 °C or lower, and particularly preferably 141 °C or lower. This composition has the following advantages: the higher the exothermic peak temperature of the composition, the better the storage stability of the composition. The above-mentioned exothermic peak temperature of this composition is preferably 120 °C or higher, more preferably 125 °C or higher, more preferably 130 °C or higher, more preferably 132 °C or higher, further preferably 134 °C or higher, and particularly preferably 138 °C or higher.

[0203] When the above-mentioned exothermic start temperature and / or the above-mentioned exothermic peak temperature of the composition are within the above ranges, a cured product having excellent adhesive strength by low-temperature curing can be provided, and it has the advantage of excellent storage stability. Regarding the above-mentioned exothermic start temperature and the above-mentioned exothermic peak temperature, for example, the structure of the amine adduct curing agent (D) (in other words, the type of the amine adduct curing agent (D)), the addition amount of the amine adduct curing agent (D), the structure of the urea compound (E), and the addition amount of the urea compound (E) may all have an impact on them. In other words, the above-mentioned exothermic start temperature and the above-mentioned exothermic peak temperature can be appropriately adjusted by changing and adjusting the structure of the amine adduct curing agent (D), the addition amount of the amine adduct curing agent (D), the structure of the urea compound (E) (in other words, the type of the urea compound (E)), the addition amount of the urea compound (E), the structure of the epoxy reactive diluent (F) (in other words, the type of the epoxy reactive diluent (F)), and the addition amount of the epoxy reactive diluent (F), etc.

[0204] <Manufacturing method of the composition>

[0205] The manufacturing method of this composition is not particularly limited, and various methods can be used. For example, it can be mentioned: a method of removing unnecessary components such as water after bringing the polymer particles (B) obtained in the form of an aqueous latex into contact with the epoxy resin (A), a method of temporarily extracting the polymer particles (B) from an organic solvent and then mixing them with the epoxy resin (A), and then removing the organic solvent, etc. As such a manufacturing method, specifically, it is preferable to use the method described in International Publication No. 2005 / 028546. More specifically, this composition is preferably prepared by a manufacturing method that sequentially includes the following first to third steps.

[0206] · First step: Mix the aqueous latex containing the polymer particles (B) (specifically, the reaction mixture after manufacturing the polymer particles (B) by emulsion polymerization) with an organic solvent having a solubility of 5% by mass to 40% by mass in water at 20 °C, and then further mix with an excessive amount of water to cause the polymer particles (B) to aggregate;

[0207] · Second step: After separating / recovering the aggregated polymer particles (B) from the liquid phase, they are mixed with an organic solvent again to obtain an organic solvent solution of the polymer particles (B);

[0208] · Third step: The above-mentioned organic solvent solution of the polymer particles (B) is further mixed with the epoxy resin (A), and then the above-mentioned organic solvent is distilled off.

[0209] When the epoxy resin (A) is in a liquid state at 23°C, the above-mentioned third step becomes easy, so it is preferred. "Being in a liquid state at 23°C" means that the softening point is 23°C or lower, and it shows fluidity at 23°C.

[0210] By adding the component (C), the component (D), and, if necessary, the epoxy resin (A), the component (E), the component (F), the inorganic filler, calcium oxide, and other components to the dispersion obtained through the above-mentioned first step to the third step, in which the polymer particles (B) are dispersed in the epoxy resin (A) in the state of primary particles, and mixing them, the present composition can be obtained. In addition, according to this manufacturing method, the present composition in a state where the polymer particles (B) are dispersed in the state of primary particles can be obtained. When the present composition is a composition in which the polymer particles (B) are dispersed in the epoxy resin (A) in the state of primary particles, the obtained cured product has the advantage of excellent impact-resistant peel adhesive strength.

[0211] In a preferred embodiment of the present invention, in the manufacturing method of the one-component thermosetting resin composition, it is preferred to have the following steps: After mixing all the components in the above-mentioned one-component thermosetting resin composition except the amine adduct curing agent (D), the above-mentioned amine adduct curing agent (D) is finally mixed. For example, it is preferred to add the component (C), and, if necessary, the epoxy resin (A), the component (E), the component (F), the inorganic filler, calcium oxide, and other components to the dispersion obtained through the above-mentioned first step to the third step, in which the polymer particles (B) are dispersed in the epoxy resin (A) in the state of primary particles, and mix them, and then finally mix the obtained mixture and the component (D) to obtain the one-component thermosetting resin composition. In the manufacturing process of a structural adhesive with a high viscosity, due to the shear heat during mixing, the temperature tends to rise easily. Therefore, by finally mixing the amine adduct curing agent (D) with a low softening temperature, the shear heat during mixing can be minimized, and as a result, the storage stability tends to be improved.

[0212] As a method for producing the single-component thermosetting resin composition (i.e., composition (I)) that satisfies the above (1), and a method for producing the single-component thermosetting resin composition (i.e., composition (I)+(III)) that satisfies both the above (1) and (3), for example, a production method having the following steps can be cited: a step of mixing component (A), component (B), component (C), and component (E) to obtain a mixture, and a step of mixing the obtained mixture and component (D). As a method for producing the single-component thermosetting resin composition (i.e., composition (II)) that satisfies the above (2), and a method for producing the single-component thermosetting resin composition (i.e., composition (II)+(III)) that satisfies both the above (2) and (3), for example, a production method having the following steps can be cited: a step of mixing component (A), component (B), component (C), and component (F) to obtain a mixture, and a step of mixing the obtained mixture and component (D). As a method for producing the single-component thermosetting resin composition (i.e., as composition (III)) that satisfies the above (3), for example, a production method having the following steps can be cited: a step of mixing component (A), component (B), component (C), and component (F) to obtain a mixture, and a step of mixing the obtained mixture and component (D). As a method for producing the single-component thermosetting resin composition (i.e., composition (I)+(II)) that satisfies both the above (1) and (2), and a method for producing the single-component thermosetting resin composition (i.e., composition (I)+(II)+(III)) that satisfies all of the above (1), (2), and (3), for example, a production method having the following steps can be cited: a step of mixing component (A), component (B), component (C), component (E), and component (F) to obtain a mixture, and a step of mixing the obtained mixture and component (D).

[0213] 〔Cured product〕

[0214] One embodiment of the present invention provides a cured product obtained by curing the present composition. In this specification, the "cured product of one embodiment of the present invention" is sometimes referred to as the "present cured product".

[0215] Since the present cured product has the above configuration, it has the advantage of excellent adhesive strength.

[0216] 〔Others〕

[0217] <Coating method>

[0218] The present composition can be coated on a substrate by any method. According to a preferred embodiment, coating can be performed at a low temperature around room temperature, and if necessary, heating can also be performed for coating. In order to make the storage stability of the present composition excellent, the method of coating by heating is particularly useful.

[0219] Apply the present composition to one or two substrates, bring the substrates into contact with each other in such a way that the composition is disposed between two substrates to be joined, and cure the composition in this state, whereby the two substrates can be joined.

[0220] When the present curable resin composition is used as a structural adhesive for joining structural members of vehicles or the like, joining can be strengthened by appropriately performing spot welding as a method of adhesive spot welding after coating the curable resin composition.

[0221] <Adhesive>

[0222] One embodiment of the present invention provides an adhesive containing the present composition. The adhesive containing the present composition has the advantages of being able to provide a cured product (adhesive layer) having excellent adhesive strength by low-temperature curing and excellent storage stability. When the present composition is used as an adhesive to bond various substrates to each other, for example, substrates such as wood, metal, plastic, and glass can be joined. Among them, joining of automotive parts is preferred, and more preferably joining of automotive frames to each other or joining of an automotive frame and other automotive parts. Examples of the substrate include various plastic-based substrates such as steel materials such as cold-rolled steel and hot-dip galvanized steel, aluminum materials such as aluminum and aluminum-clad, general plastics, engineering plastics, and composite materials such as CFRP and GFRP. The present curable resin composition can be used alone as an adhesive, or can be used as an adhesive in which the present composition and other components are mixed as needed.

[0223] The cured product obtained by curing the present composition has excellent adhesive strength, and thus the present composition can be suitably used as a structural adhesive for adhesive spot welding. That is, one embodiment of the present invention provides a structural adhesive for adhesive spot welding containing the present composition.

[0224] Apply the adhesive containing the present composition to one or both of two substrates, bring the two substrates into contact with each other in such a way that the adhesive containing the present composition is disposed between the two substrates, and cure the present composition in this state, whereby the two substrates can be joined through the cured product. That is, one embodiment of the present invention provides a laminate including at least two substrates and an adhesive layer joining the at least two substrates, the adhesive layer being formed by curing an adhesive containing the present composition or an adhesive for adhesive spot welding containing the present composition.

[0225] The laminate according to one embodiment of the present invention can be expressed as follows:

[0226] A laminate including a first substrate, a cured product formed by curing an adhesive containing the present composition or an adhesive for adhesive spot welding containing the present composition, and a second substrate, which are laminated in this order.

[0227] The adhesive strength of this composition is excellent. Therefore, it is preferable that after sandwiching this composition between a plurality of members including an aluminum substrate and bonding them, the above composition is cured, and the laminate obtained by joining the above members shows high adhesive strength.

[0228] In recent years, in order to reduce weight, there has been a tendency to frequently use aluminum materials as the base materials of automotive parts. The linear expansion coefficients of aluminum materials and steel materials are very different. Generally, when using an adhesive to bond different base materials with greatly different linear expansion coefficients to each other, after curing the adhesive at a high temperature (for example, 170°C to 190°C), when the temperature drops to room temperature, there is a case where the joint part is severely deformed. This composition can be cured at a low temperature (for example, 120°C to 140°C) and has excellent toughness. Therefore, as described above, even when joining different base materials with different linear expansion coefficients to each other using an adhesive containing this composition or an adhesive for adhesive spot welding containing this composition, it has the advantage of being able to improve the deformation of the joint part. In other words, at least two base materials are preferably at least two base materials with different linear expansion coefficients (for example, the difference is 5×10 -6 / °C or more).

[0229] In addition, this composition can be used for joining aerospace structural materials, especially for joining packaging metal structural materials.

[0230] <Curing Temperature>

[0231] The curing temperature of this composition (for example, the curing temperature of the composition when manufacturing the above laminate) only needs to be 100°C or more, and there is no particular limitation. It is preferably 115°C to 145°C, more preferably 117°C to 140°C, further preferably 118°C to 135°C, and particularly preferably 120°C to 130°C.

[0232] The curing time of this composition (for example, the curing time of the composition when manufacturing the above laminate) is preferably 10 minutes to 60 minutes, more preferably 12 minutes to 40 minutes, further preferably 13 minutes to 30 minutes, and particularly preferably 15 minutes to 25 minutes.

[0233] In other words, the manufacturing method of the laminate according to one embodiment of the present invention preferably has the following steps: curing the above single-component thermosetting resin composition, the above adhesive, or the above adhesive for adhesive spot welding under the conditions of a curing temperature of 115°C to 145°C and a curing time of 10 minutes to 60 minutes.

[0234] Before the step of curing the above-mentioned single-component thermosetting resin composition, the above-mentioned adhesive, or the above-mentioned adhesive for spot welding, the manufacturing method of the laminate according to an embodiment of the present invention may further include the following steps:

[0235] A step of applying the above-mentioned single-component thermosetting resin composition, the above-mentioned adhesive, or the above-mentioned adhesive for spot welding to one or both of two substrates; and

[0236] A step of bringing the two substrates into contact with each other so that the above-mentioned single-component thermosetting resin composition, the above-mentioned adhesive, or the above-mentioned adhesive for spot welding is disposed between the two substrates.

[0237] When this composition is used as an adhesive for automobiles, from the viewpoint of shortening / simplifying the process, it is preferable that after applying the adhesive to an automobile member, a coating agent such as electrodeposition coating is then applied, and the coating agent is sintered / cured while curing the adhesive.

[0238] <Usage>

[0239] This composition can preferably be used for adhesives such as structural adhesives for vehicles and aircraft, structural adhesives for wind power generation, coatings, materials for laminating glass fibers, and materials for printed wiring boards, solder resist, interlayer insulating films, assembly materials, adhesives for FPCs, electrical insulating materials such as sealing materials for electronic components such as semiconductors / LEDs, chip bonding materials, underfill materials, ACF, ACP, NCF, NCP and other semiconductor mounting materials, liquid crystal panels, OLED lighting, OLED displays and other display devices / lighting and their sealing materials. In particular, it is useful as a structural adhesive for spot welding.

[0240] An embodiment of the present invention may have the following configuration.

[0241] 〔1〕A single-component thermosetting resin composition, which contains an epoxy resin (A), and relative to 100 parts by mass of the epoxy resin (A), further contains:

[0242] 1 to 100 parts by mass of polymer particles (B) having a core-shell structure including a core layer and a shell layer, 3.5 to 19.0 parts by mass of dicyandiamide (C), and

[0243] 0.3 to 10.0 parts by mass of an amine adduct curing agent (D) that is solid at room temperature,

[0244] In the DSC curve of the single-component thermosetting resin composition measured using a differential scanning calorimeter at a heating rate of 10 °C / minute, the exothermic start temperature is 80 °C or higher, and the exothermic peak temperature is 150 °C or lower.

[0245] The single-component thermosetting resin composition satisfies at least one of the following (1) to (3): (1)

[0247] further contains 0.5 parts by mass to 15.0 parts by mass of a urea compound (E) represented by the general formula (X);

[0248] R 1 -NH-C(=O)-N-R 2 2…(X)

[0249] In the formula, R 1 is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, and two Rs 2 are each independently a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms;

[0250] The ratio (Wc / We) of the total mass Wc of the dicyandiamide (C) to the total mass We of the urea compound (E) is 1.1 to 20.0, and

[0251] The ratio (We / Wd) of the total mass We of the urea compound (E) to the total mass Wd of the amine adduct curing agent (D) is 1.1 to 20.0; (2)

[0253] further contains 1.0 part by mass to 20.0 parts by mass of an epoxy-based reactive diluent (F); and (3)

[0255] The shell of the polymer particles (B) has an epoxy group,

[0256] The content of the epoxy group in the shell, relative to the total mass of the shell, exceeds 0 mmol / g and is 2.0 mmol / g or less.

[0257] 〔2〕The single-component thermosetting resin composition according to 〔1〕, which satisfies the above (1) and / or (2), and in addition,

[0258] The shell of the polymer particles (B) has an epoxy group, and the content of the epoxy group in the shell, relative to the total mass of the shell, exceeds 0 mmol / g and is 2.0 mmol / g or less.

[0259] 〔3〕The single-component thermosetting resin composition according to 〔1〕, which satisfies the above (1) and / or (2), and in addition,

[0260] The shell of the polymer particles (B) does not have an epoxy group.

[0261] 〔4〕The single-component thermosetting resin composition according to any one of 〔1〕to 〔3〕, which satisfies the above (1), further comprises:

[0262] 1.0 to 20.0 parts by mass of an epoxy-based reactive diluent (F).

[0263] 〔5〕The single-component thermosetting resin composition according to any one of 〔1〕to 〔4〕, wherein

[0264] the epoxy resin (A) comprises bisphenol A type epoxy resin and / or bisphenol F type epoxy resin.

[0265] 〔6〕The single-component thermosetting resin composition according to any one of 〔1〕to 〔5〕, wherein

[0266] the core layer comprises one or more selected from diene-based rubbers, (meth)acrylate-based rubbers, and silicone rubber-based rubbers.

[0267] 〔7〕The single-component thermosetting resin composition according to any one of 〔1〕to 〔6〕, wherein

[0268] the core layer is butadiene rubber and / or butadiene-styrene rubber.

[0269] 〔8〕The single-component thermosetting resin composition according to any one of 〔1〕to 〔7〕, wherein

[0270] the shell layer comprises a structural unit derived from one or more monomers selected from aromatic vinyl-based monomers, acrylonitrile-based monomers, and (meth)acrylate-based monomers.

[0271] 〔9〕The single-component thermosetting resin composition according to any one of 〔1〕to 〔8〕, wherein

[0272] the amine adduct curing agent (D) comprises one or more selected from amine-epoxy adduct curing agents and urea adduct curing agents.

[0273] 〔10〕The single-component thermosetting resin composition according to any one of 〔1〕to 〔9〕, wherein

[0274] the epoxy-based reactive diluent (F) comprises an epoxy-based reactive diluent having one epoxy group in one molecule.

[0275] 〔11〕The single-component thermosetting resin composition according to any one of 〔1〕to 〔10〕, wherein

[0276] the amine adduct curing agent (D) comprises an amine adduct curing agent having a softening temperature of 80°C to 140°C.

[0277] 〔12〕The single-component thermosetting resin composition according to any one of 〔1〕 to 〔11〕, wherein,

[0278] the urea compound (E) contains 3-(3,4-dichlorophenyl)-1,1-dimethylurea and / or 3,3'-[methylenebis(4,1-phenylene)]bis(1,1-dimethylurea).

[0279] 〔13〕A cured product obtained by curing the single-component thermosetting resin composition according to any one of 〔1〕 to 〔12〕.

[0280] 〔14〕An adhesive comprising the single-component thermosetting resin composition according to any one of 〔1〕 to 〔12〕.

[0281] 〔15〕A structural adhesive for weld bond comprising the single-component thermosetting resin composition according to any one of 〔1〕 to 〔12〕.

[0282] 〔16〕A laminate comprising:

[0283] at least two substrates, and

[0284] an adhesive layer joining the at least two substrates,

[0285] wherein the adhesive layer is formed by curing the adhesive according to 〔14〕 or the weld bond adhesive according to 〔15〕.

[0286] 〔17〕In the laminate according to 〔16〕, the at least two substrates are at least two substrates having different coefficients of linear expansion.

[0287] 〔18〕A method for manufacturing a laminate, which is a method for manufacturing the laminate according to 〔16〕, the method comprising:

[0288] a step of curing the single-component thermosetting resin composition, the adhesive or the weld bond adhesive under the conditions of a curing temperature of 115°C to 145°C and a curing time of 10 minutes to 60 minutes.

[0289] 〔19〕A method for manufacturing a single-component thermosetting resin composition, which is a method for manufacturing the single-component thermosetting resin composition according to any one of 〔1〕 to 〔12〕, the method comprising:

[0290] a step of mixing all the components in the single-component thermosetting resin composition except the amine adduct curing agent (D), and finally mixing the amine adduct curing agent (D).

[0291] Examples

[0292] Hereinafter, an embodiment of the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to these. An embodiment of the present invention can be carried out by appropriately modifying the following Examples within the scope that conforms to the above and the following themes. Embodiments carried out by appropriately modifying the following Examples are all included in the technical scope of the present invention. It should be noted that in the following Examples, Comparative Examples and tables, "parts" and "%" refer to parts by mass and mass%, respectively.

[0293] (Evaluation Method)

[0294] First, the evaluation method of the single-component thermosetting resin composition produced by Examples and Comparative Examples will be described below.

[0295] [Measurement of Volume Average Particle Size]

[0296] The volume average particle size (Mv) of the polymer particles (B) dispersed in the aqueous latex was measured using Microtrac UPA150 (manufactured by Nikkiso Co., Ltd.). A sample obtained by diluting the aqueous latex with deionized water was used as the measurement sample. The measurement was carried out as follows: The refractive index of water and the refractive index of the polymer particles (B) obtained by each production example were input, and the measurement time was 600 seconds, and the sample concentration was adjusted so that the Signal Level was in the range of 0.6 to 0.8.

[0297] [DSC Parameters]

[0298] The exothermic onset temperature and exothermic peak temperature of the composition were measured by the following method: 0.02 g of the composition was used as a sample, and differential scanning calorimetry was carried out using a differential scanning calorimeter (DSC 7020, manufactured by Hitachi High-Tech Science Corporation) under the condition of a heating rate of 10 °C / minute. The exothermic onset temperature and exothermic peak temperature of the composition were calculated from the obtained DSC curve.

[0299] [Measurement of Shear Bonding Strength]

[0300] The method for measuring the shear bond strength of the cured product formed by curing the composition is as follows: The composition was applied to two cold-rolled steel sheets (SPCC steel sheets) with dimensions of 25 mm in width × 100 mm in length × 1.6 mm in thickness, and the two cold-rolled steel sheets were overlapped so that the thickness of the adhesive layer was 0.25 mm. Thereafter, the composition between the two cold-rolled steel sheets was cured under the conditions of 120 °C and 20 minutes to obtain a laminate. The obtained laminate was used as a sample, and the shear bond strength (MPa) was measured using Autograph AG-2000E (manufactured by Shimadzu Corporation) in accordance with JIS K6850. As the measurement conditions, the measurement temperature was set at 23 °C and the test speed was set at 1.3 mm / min.

[0301] [Measurement of T-peel bond strength]

[0302] The method for measuring the T-peel bond strength of the cured product formed by curing the composition is as follows: The composition was applied to two cold-rolled steel sheets (SPCC steel sheets) with dimensions of 25 mm in width × 200 mm in length × 0.5 mm in thickness, and the two cold-rolled steel sheets were overlapped so that the thickness of the adhesive layer was 0.25 mm. Thereafter, the composition between the two cold-rolled steel sheets was cured under the conditions of 120 °C and 20 minutes to obtain a laminate. The obtained laminate was used as a sample, and the T-peel bond strength (N / 25 mm) was measured in accordance with JIS K6854. As the measurement conditions, the measurement temperature was set at 23 °C and the test speed was set at 254 mm / min.

[0303] [Measurement of dynamic fracture resistance (impact-resistant peel adhesiveness)]

[0304] The method for measuring the shear bond strength of the cured product formed by curing the composition is as follows: The composition was applied to two cold-rolled steel sheets (SPCC steel sheets) with dimensions of 20 mm in width × 90 mm in length × 0.8 mm in thickness, and the two cold-rolled steel sheets were overlapped so that the thickness of the adhesive layer was 0.25 mm. Thereafter, the composition between the two cold-rolled steel sheets was cured under the conditions of 120 °C and 20 minutes to obtain a laminate. The obtained laminate was used as a sample, and the dynamic fracture resistance (impact-resistant peel adhesiveness) at 23 °C (kN / m) was measured in accordance with ISO 11343.

[0305] [Measurement of shear rate dependence of viscosity (operability)]

[0306] The method for measuring the shear rate dependence of the viscosity of the composition is as described in the following (i) to (ii): (i) The viscosities of the composition at 50 °C were measured using a rheometer at shear rates of 1 s -1 and 10 s -1 respectively; (ii) Then, the value at 1 s -1The viscosity of the composition and 10 s -1 The ratio of the viscosity of the composition (1 s -1 The viscosity of the composition / 10 s -1 The viscosity of the composition), and the obtained value is used as the shear rate dependence of the viscosity.

[0307] The shear rate dependence of the viscosity (= 1 s -1 The viscosity of the composition / 10 s -1 The viscosity of the composition) The larger the value, the better the operability.

[0308] [Measurement of viscosity increase rate (storage stability)]

[0309] The method for measuring the viscosity increase rate of the composition is as described in the following (i) to (iv): (i) Using a rheometer, the viscosity of the composition at 50 °C was measured at a shear rate of 5 s -1 The viscosity of the composition was measured; (ii) Then, the composition was left (stored) at 40 °C for 14 days; (iii) After leaving, the viscosity of the composition at 50 °C was measured using a rheometer at a shear rate of 5 s -1 The viscosity of the composition was measured; (iv) Then, the ratio of the viscosity of the composition after leaving (storage) to the viscosity of the composition before leaving (storage) (viscosity of the composition after storage / viscosity of the composition before storage) was calculated, and the obtained value was used as the viscosity increase rate.

[0310] 1. Formation of the core layer

[0311] Production Example 1-1; Preparation of polybutadiene rubber latex (R-1)

[0312] Into a pressure-resistant polymerization reactor with a volume of 100 L, 200 parts by mass of deionized water, 0.03 part by mass of tripotassium phosphate, 0.25 part by mass of potassium dihydrogen phosphate, 0.002 part by mass of disodium ethylenediaminetetraacetate (EDTA), 0.001 part by mass of ferrous sulfate heptahydrate (FE), and 1.5 parts by mass of sodium dodecylbenzenesulfonate (SDS) as an emulsifier were charged. Then, while stirring the charged raw materials, the gas inside the pressure-resistant polymerization reactor was replaced with nitrogen to sufficiently remove oxygen from the inside of the pressure-resistant polymerization reactor. Thereafter, 100 parts by mass of butadiene (BD) was charged into the pressure-resistant polymerization reactor, and the temperature inside the pressure-resistant polymerization reactor was raised to 45°C. Thereafter, 0.015 part by mass of perhydrocumene hydroperoxide (PHP) was charged into the pressure-resistant polymerization reactor, and then 0.04 part by mass of sodium formaldehyde sulfoxylate (SFS) was charged into the pressure-resistant polymerization reactor, and polymerization was started. At the 10th hour after the start of polymerization, devolatilization was carried out under reduced pressure, and the monomers remaining unused in the polymerization were removed by devolatilization, thereby ending the polymerization. During the polymerization, PHP, EDTA, and FE were added to the pressure-resistant polymerization reactor in arbitrary amounts and at any timing. Through this polymerization, a latex (R-1) containing a core layer (polybutadiene rubber particles) mainly composed of polybutadiene rubber was obtained. The volume average particle diameter of the polybutadiene rubber particles contained in the obtained latex was 0.10 μm.

[0313] Production Example 1-2; Preparation of Polybutadiene Rubber Latex (R-2)

[0314] Into a pressure-resistant polymerization reactor with a volume of 100 L, 21 parts by mass of the polybutadiene rubber latex (R-1) obtained in Production Example 1-1 (containing 7 parts by mass of polybutadiene rubber particles), 200 parts by mass of deionized water, 0.03 part by mass of tripotassium phosphate, 0.002 part by mass of EDTA, and 0.001 part by mass of FE were charged. Then, while stirring the charged raw materials, the gas inside the pressure-resistant polymerization reactor was replaced with nitrogen to sufficiently remove oxygen from the inside of the pressure-resistant polymerization reactor. Thereafter, 93 parts by mass of BD was charged into the pressure-resistant polymerization reactor, and the temperature inside the pressure-resistant polymerization reactor was raised to 45°C. Thereafter, 0.02 part by mass of PHP was charged into the pressure-resistant polymerization reactor, and then 0.10 part by mass of SFS was charged into the pressure-resistant polymerization reactor, and polymerization was started. At the 30th hour after the start of polymerization, devolatilization was carried out under reduced pressure, and the monomers remaining unused in the polymerization were removed by devolatilization, thereby ending the polymerization. During the polymerization, PHP, EDTA, and FE were added to the pressure-resistant polymerization reactor in arbitrary amounts and at any timing. Through this polymerization, a latex (R-2) containing a core layer (polybutadiene rubber particles) mainly composed of polybutadiene rubber was obtained. The volume average particle diameter of the polybutadiene rubber particles contained in the obtained latex was 0.20 μm.

[0315] 2. Preparation of Polymer Particles (B) (Formation of Shell Layer)

[0316] Production Example 2-1; Preparation of Core-Shell Polymer Latex (L-1)

[0317] 262 parts by mass of the polybutadiene rubber latex (R-2) prepared in Production Example 1-2 (including 87 parts by mass of polybutadiene rubber particles) and 57 parts by mass of deionized water were charged into a glass reactor. Here, the above-mentioned glass reactor is equipped with a thermometer, a stirrer, a reflux condenser, a nitrogen gas inlet, and a monomer addition device. The gas in the glass reactor was replaced with nitrogen, and while performing this nitrogen replacement, the charged raw materials were stirred at 60°C. Next, 0.004 parts by mass of EDTA, 0.001 parts by mass of FE, and 0.2 parts by mass of SFS were added into the glass reactor. Thereafter, a mixture of monomers for forming the shell layer (6 parts by mass of methyl acrylate (MA), 2.7 parts by mass of butyl acrylate (BA), 4.3 parts by mass of glycidyl methacrylate (GMA)) and 0.04 parts by mass of cumene hydroperoxide (CHP) was continuously added into the glass reactor over 120 minutes. After the addition was completed, 0.04 parts by mass of CHP was added into the glass reactor, and the stirring of the mixture in the glass reactor was further continued for 2 hours to complete the polymerization. Through the above operations, an aqueous latex (L-1) containing polymer particles (B) (core-shell polymer) was obtained. The polymerization conversion rate of the monomer components was 99% or more. The volume average particle diameter of the polymer particles (B) contained in the obtained aqueous latex (L-1) was 0.21 μm. The content of epoxy groups was 2.3 mmol / g relative to the total mass of the shell layer of the polymer particles (B).

[0318] Production Example 2-2; Preparation of Core-Shell Polymer Latex (L-2)

[0319] <1 part by mass of methyl methacrylate (MMA), 6 parts by mass of styrene (ST), 2 parts by mass of acrylonitrile (AN), and 4 parts by mass of GMA> was used to replace <6 parts by mass of MA, 2.7 parts by mass of BA, and 4.3 parts by mass of GMA> in Production Example 2-1 as the monomers for forming the shell layer, and an aqueous latex (L-2) containing polymer particles (B) (core-shell polymer) was obtained in the same manner as in Production Example 2-1. The volume average particle diameter of the polymer particles (B) contained in the obtained aqueous latex (L-2) was 0.21 μm. The content of epoxy groups was 2.2 mmol / g relative to the total mass of the shell layer of the polymer particles (B).

[0320] Production Example 2-3; Preparation of Core-Shell Polymer Latex (L-3)

[0321] <MMA 3 parts by mass, ST 6 parts by mass, AN 2 parts by mass, and GMA 2 parts by mass> was used to replace <MA 6 parts by mass, BA 2.7 parts by mass, and GMA 4.3 parts by mass> of Production Example 2-1 as the monomers for forming the shell layer. Otherwise, an aqueous latex (L-3) containing polymer particles (B) (core-shell polymer) was obtained in the same manner as in Production Example 2-1. The volume average particle diameter of the polymer particles (B) contained in the obtained aqueous latex (L-3) was 0.21 μm. The content of epoxy groups was 1.1 mmol / g relative to the total mass of the shell layer of the polymer particles (B).

[0322] Production Example 2-4; Preparation of Core-Shell Polymer Latex (L-4)

[0323] <MMA 4 parts by mass, ST 6 parts by mass, AN 2 parts by mass, and GMA 1 part by mass> was used to replace <MA 6 parts by mass, BA 2.7 parts by mass, and GMA 4.3 parts by mass> of Production Example 2-1 as the monomers for forming the shell layer. Otherwise, an aqueous latex (L-4) containing polymer particles (B) (core-shell polymer) was obtained in the same manner as in Production Example 2-1. The volume average particle diameter of the polymer particles (B) contained in the obtained aqueous latex (L-4) was 0.21 μm. The content of epoxy groups was 0.5 mmol / g relative to the total mass of the shell layer of the polymer particles (B).

[0324] Production Example 2-5; Preparation of Core-Shell Polymer Latex (L-5)

[0325] <MMA 5 parts by mass, ST 6 parts by mass, and AN 2 parts by mass> was used to replace <MA 6 parts by mass, BA 2.7 parts by mass, and GMA 4.3 parts by mass> of Production Example 2-1 as the monomers for forming the shell layer. Otherwise, an aqueous latex (L-5) containing polymer particles (B) (core-shell polymer) was obtained in the same manner as in Production Example 2-1. The volume average particle diameter of the polymer particles (B) contained in the obtained aqueous latex (L-5) was 0.21 μm. The content of epoxy groups was 0.0 mmol / g relative to the total mass of the shell layer of the polymer particles (B).

[0326] 3. Preparation of Dispersion (M) in Which Polymer Particles (B) are Dispersed in a Curable Resin

[0327] Production Examples 3-1 to 3-5; Preparation of Dispersions (M-1) to (M-5)

[0328] 132 g of methyl ethyl ketone (MEK) was introduced into a 1-L mixing tank at 25°C. Subsequently, while stirring the MEK, 132 g of the aqueous latex of each production example shown in Table 1 (equivalent to 40 g of polymer particles (B)) was added to the mixing tank. After uniformly mixing the raw materials in the mixing tank, while stirring the raw materials in the mixing tank, 200 g of water was added to the mixing tank at a supply rate of 80 g / min. After the supply of water was completed, stirring was quickly stopped, and a slurry composed of aggregates containing polymer particles (B) and an aqueous phase containing a small amount of organic solvent was obtained. The above-mentioned aggregates were floating. Subsequently, 360 g of the aqueous phase was discharged through the discharge port at the bottom of the mixing tank so that the aggregates containing a part of the aqueous phase remained in the mixing tank. 90 g of MEK was added to the obtained aggregates and uniformly mixed to obtain a dispersion in which polymer particles (B) were uniformly dispersed in MEK. To the obtained dispersion, 60 g of epoxy resin (A-1) as component (A) was added and uniformly mixed. The epoxy resin (A-1) will be described in detail below. MEK was removed from the obtained mixture using a rotary evaporation device. Thus, dispersions (M-1) to (M-5) in which polymer particles (B) were dispersed in epoxy resin (A) were obtained.

[0329] [Table 1]

[0330] Production Example Dispersion Aqueous latex 3-1 M-1 L-1 3-2 M-2 L--2 3-3 M-3 L-3 3-4 M-4 L--4 3-5 M-5 L-5

[0331] (Examples 1 to 31, Comparative Examples 1 to 14)

[0332] According to the formulations (compositions) shown in Tables 2 to 7, each component was measured and thoroughly mixed to obtain a one-component thermosetting resin composition. It should be noted that in the case of containing an amine adduct curing agent (D), after measuring all components except component (D) and thoroughly mixing them, component (D) was finally measured and thoroughly mixed to obtain a one-component thermosetting resin composition. The shear bond strength, T-peel bond strength, dynamic fracture resistance (impact-resistant peel adhesiveness), shear rate dependence of viscosity (operability), and viscosity increase rate (storage stability) of the obtained compositions were measured by the above methods, and the test results are shown in Tables 2 to 7.

[0333] It should be noted that the following agents were used as various compounding agents in Tables 2 to 7.

[0334] <Epoxy resin (A)>

[0335] A-1: JER828 (manufactured by Mitsubishi Chemical, a bisphenol A type epoxy resin (BisA epoxy resin) that is liquid at room temperature, epoxy equivalent: 184 g / eq to 194 g / eq)

[0336] A-2: JER807 (manufactured by Mitsubishi Chemical, bisphenol F type epoxy resin (BisF epoxy resin) which is liquid at room temperature, epoxy equivalent: 160 g / eq to 175 g / eq)

[0337] A-3: HyPox RA1340 (manufactured by CVC, rubber-modified epoxy resin, epoxy equivalent: 350 g / eq)

[0338] <Dispersion (M) in which polymer particles (B) are dispersed in epoxy resin (A)>

[0339] M-1 to M-5: Dispersions obtained in the above Production Examples 3-1 to 5

[0340] <Dicyandiamide (C)>

[0341] Dyhard 100S (manufactured by AlzChem, dicyandiamide)

[0342] <Amine adduct curing agent (D)>

[0343] Ajicure PN-40 (manufactured by Ajinomoto Fine-Techno, amine-epoxy adduct curing agent, softening temperature: 108 °C, particle size: 11.6 μm)

[0344] Ajicure PN-23 (manufactured by Ajinomoto Fine-Techno, amine-epoxy adduct curing agent, softening temperature: 95 °C, particle size: 12.3 μm)

[0345] Ajicure PN-23J (manufactured by Ajinomoto Fine-Techno, amine-epoxy adduct curing agent, softening temperature: 95 °C, particle size: 2.6 μm)

[0346] Ajicure PN-50 (manufactured by Ajinomoto Fine-Techno, amine-epoxy adduct curing agent, softening temperature: 115 °C, particle size: 11.4 μm)

[0347] Ajicure PN-40J (manufactured by Ajinomoto Fine-Techno, amine-epoxy adduct curing agent, softening temperature: 106 °C, particle size: 2.7 μm)

[0348] <Urea compound (E)>

[0349] Dyhard UR200 (manufactured by AlzChem, 3-(3,4-dichlorophenyl)-1,1-dimethylurea)

[0350] Omicure 52 (manufactured by Huntsman, 3,3’-[methylenebis(4,1-phenylene)]bis(1,1-dimethylurea))

[0351] Dyhard UR500 (manufactured by AlzChem, 1,1'-(4-methyl-1,3-phenylene)bis(3,3-dimethylurea))

[0352] "Modified Aliphatic Polyamine"

[0353] Ancamine 2014AS (manufactured by Evonik)

[0354] <Epoxy Reactive Diluent (F)>

[0355] YED216M (manufactured by Mitsubishi Chemical, 1,6-hexanediol diglycidyl ether)

[0356] Cardura E10P (manufactured by Hexion, glycidyl neodecanoate)

[0357] ERISYS GE-10 (manufactured by Huntsman, o-tolyl glycidyl ether)

[0358] 4-tert-butylphenyl glycidyl ether (manufactured by Tokyo Chemical Industry)

[0359] "Fumed Silica"

[0360] CAB-O-SIL TS-720 (manufactured by CABOT, fumed silica surface-treated with polydimethylsiloxane) (marked as "TS-720" in the table),

[0361] "Calcium Carbonate"

[0362] THITON SB (manufactured by Shiraishi Calcium, untreated heavy calcium carbonate)

[0363] "Calcium Oxide"

[0364] CML#31 (manufactured by Omi Chemical Industry, calcium oxide surface-treated with fatty acid).

[0365]

[0366]

[0367]

[0368]

[0369]

[0370]

[0371] Industrial Applicability

[0372] According to one embodiment of the present invention, a cured product having excellent adhesive strength by low-temperature curing can be provided, and a one-component thermosetting resin composition having excellent storage stability can be provided. Therefore, one embodiment of the present invention can be suitably used for adhesives, particularly structural adhesives for vehicles.

Claims

1. A one - component thermosetting resin composition, which contains an epoxy resin (A), and per 100 parts by mass of the epoxy resin (A), further contains: 1 to 100 parts by mass of polymer particles (B) having a core - shell structure including a core layer and a shell layer, 3.5 to 19.0 parts by mass of dicyandiamide (C), and 0.3 to 10.0 parts by mass of an amine - adduct curing agent (D) that is solid at room temperature, In the DSC curve of the one - component thermosetting resin composition measured using a differential scanning calorimeter under the condition of a heating rate of 10 °C / min, the exothermic start temperature is 80 °C or higher, and the exothermic peak temperature is 150 °C or lower. The one - component thermosetting resin composition satisfies at least one of the following (1) to (3): (1) Further contains 0.5 to 15.0 parts by mass of a urea compound (E) represented by the general formula (X); R 1 -NH-C(=O)-N-R 2 2…(X) In the formula, R 1 is a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms, and two Rs 2 each independently are a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms; The ratio (Wc / We) of the total mass Wc of the dicyandiamide (C) to the total mass We of the urea compound (E) is 1.1 to 20.0, and The ratio (We / Wd) of the total mass We of the urea compound (E) to the total mass Wd of the amine - adduct curing agent (D) is 1.1 to 20.0; (2) Further contains 1.0 to 20.0 parts by mass of an epoxy - based reactive diluent (F); and (3) The shell layer of the polymer particles (B) has an epoxy group, The content of the epoxy group in the shell layer, relative to the total mass of the shell layer, exceeds 0 mmol / g and is 2.0 mmol / g or less.

2. The one - component thermosetting resin composition according to claim 1, which satisfies the above (1) and / or (2), and The shell layer of the polymer particles (B) has an epoxy group, and the content of the epoxy group in the shell layer, relative to the total mass of the shell layer, exceeds 0 mmol / g and is 2.0 mmol / g or less.

3. The one - component thermosetting resin composition according to claim 1, which satisfies the above (1) and / or (2), and The shell layer of the polymer particles (B) does not have an epoxy group.

4. The one - component thermosetting resin composition according to claim 1, which satisfies the above (1), and the one - component thermosetting resin composition further contains: 1.0 to 20.0 parts by mass of an epoxy - based reactive diluent (F).

5. The one - component thermosetting resin composition according to claim 1, wherein The core layer contains one or more selected from diene - based rubbers, (meth)acrylate - based rubbers, and silicone - based rubbers.

6. The one - component thermosetting resin composition according to claim 1, wherein The shell layer contains a structural unit derived from one or more monomers selected from aromatic vinyl - based monomers, acrylonitrile - based monomers, and (meth)acrylate - based monomers.

7. The one - component thermosetting resin composition according to claim 1, which satisfies the above (2), and The epoxy - based reactive diluent (F) contains an epoxy - based reactive diluent having 1 epoxy group in one molecule.

8. The single-component thermosetting resin composition according to claim 1, wherein, the amine adduct curing agent (D) comprises an amine adduct curing agent having a softening temperature of 80°C to 140°C.

9. The single-component thermosetting resin composition according to claim 1, which satisfies the above (1), and the urea compound (E) comprises 3-(3,4-dichlorophenyl)-1,1-dimethylurea and / or 3,3'-[methylenebis(4,1-phenylene)]bis(1,1-dimethylurea).

10. A cured product obtained by curing the single-component thermosetting resin composition according to any one of claims 1 to 9.

11. An adhesive comprising the single-component thermosetting resin composition according to any one of claims 1 to 9.

12. A laminate comprising: at least two substrates, and an adhesive layer bonding the at least two substrates, Among them, wherein the adhesive layer is formed by curing the adhesive according to claim 11.

13. The laminate according to claim 12, wherein the at least two substrates are at least two substrates having different coefficients of linear expansion.

14. A method for manufacturing a laminate, which is a method for manufacturing the laminate according to claim 12, the method comprising: a step of curing the adhesive under the conditions of a curing temperature of 115°C to 145°C and a curing time of 10 minutes to 60 minutes.

15. A method for manufacturing a single-component thermosetting resin composition, which is a method for manufacturing the single-component thermosetting resin composition according to any one of claims 1 to 9, the method comprising: a step of mixing all components of the single-component thermosetting resin composition except the amine adduct curing agent (D), and finally mixing the amine adduct curing agent (D).

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