Curable resin composition, use of curable resin composition, cured product, and method for producing cured product

Abstract

The present invention addresses the problem of providing a curable resin composition capable of providing a cured product having an excellent balance between heat resistance and toughness when cured at a low temperature. This curable resin composition contains (i) an epoxy resin, (ii) one or more types selected from the group consisting of polymer particles, a blocked urethane, a rubber-modified epoxy resin and a urethane-modified epoxy resin, (iii) an epoxy curing agent containing an alicyclic amine and / or a polyamideamine, and (iv) an epoxy-based reactive diluent.

Description

CURABLE RESIN COMPOSITION, USE OF CURABLE RESIN COMPOSITION, CURED PRODUCT, AND METHOD FOR PRODUCING CURED PRODUCT

[0001] The present invention relates to a curable resin composition, use of the curable resin composition, a cured product, and a method for producing the cured product.

[0002] Curable resin compositions containing epoxy resins are used in many fields.

[0003] In recent years, from the viewpoint of environmental friendliness, there has been a demand for curable resin compositions that can be cured at lower temperatures and that can provide cured products that exhibit excellent physical properties.

[0004] For example, Patent Document 1 discloses a curable resin composition that can be used as a room temperature curable two-component or multi-component adhesive.

[0005] JP 2023-146870 A

[0006] However, the above-mentioned conventional techniques are not sufficient in terms of the balance between heat resistance and toughness of the cured product obtained by curing at low temperatures, and there is room for further improvement.

[0007] One embodiment of the present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a novel curable resin composition that can provide a cured product that has an excellent balance between heat resistance and toughness when cured at low temperature.

[0008] A curable resin composition according to one embodiment of the present invention is a curable resin composition for low temperature curing, and comprises the following components (A), (B), (C), and (D): component (A): an epoxy resin; component (B): one or more selected from the group consisting of the following components (b1), (b2), (b3), and (b4); component (b1): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (b2): blocked urethane; component (b3): ​​rubber-modified epoxy resin; component (b4): urethane-modified epoxy resin; component (C): epoxy curing agent; component (D): epoxy-based reactive diluent; and satisfies the following (1) and / or (2): (1) the component (C) comprises the following component (c1): component (c1): alicyclic amine; the content of the component (c1) is 25% by mass to 100% by mass in 100% by mass of the component (C); (2) The component (C) contains the following component (c2): component (c2): polyamidoamine; the active hydrogen equivalent of the component (C) is 50 g / eq to 90 g / eq, and the content of the component (c2) is 25 mass% to 100 mass% relative to 100 mass% of the component (C).

[0009] A curable resin composition according to one embodiment of the present invention is a two-component or multi-component curable resin composition for low-temperature curing, comprising a first component and a second component, wherein the first component comprises the following components (A) and (D): component (A): an epoxy resin; component (D): an epoxy-based reactive diluent; the second component comprises the following component (C): component (C): an epoxy curing agent; the curable resin composition further comprises the following component (B): component (B): one or more selected from the group consisting of the following components (b1), (b2), (b3), and (b4): component (b1): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (b2): blocked urethane; component (b3): ​​rubber-modified epoxy resin; component (b4): urethane-modified epoxy resin; and satisfies the following (1) and / or (2): (1) the component (C) comprises the following component (c1): component (c1): alicyclic amine; The content of the component (c1) in 100% by mass of the component (C) is 25% by mass to 100% by mass; (2) The component (C) includes the following component (c2), component (c2): polyamidoamine; the active hydrogen equivalent of the component (C) is 50 g / eq to 90 g / eq, and the content of the component (c2) in 100% by mass of the component (C) is 25% by mass to 100% by mass.

[0010] A cured product according to one embodiment of the present invention is obtained by curing a curable resin composition containing the following components (A), (B), (C), and (D): component (A): an epoxy resin; component (B): one or more selected from the group consisting of the following components (b1), (b2), (b3), and (b4); component (b1): polymer particles having a core-shell structure containing a core layer and a shell layer; component (b2): blocked urethane; component (b3): ​​rubber-modified epoxy resin; component (b4): urethane-modified epoxy resin; component (C): epoxy curing agent; component (D): epoxy-based reactive diluent; and the degree of cure measured by differential scanning calorimetry (DSC) is 50% to 95%, and the curable resin composition satisfies the following (1) and / or (2): (1) the component (C) contains the following component (c1): component (c1): alicyclic amine; (2) The component (C) contains the following component (c2): component (c2): polyamidoamine; the active hydrogen equivalent of the component (C) is 50 g / eq to 90 g / eq.

[0011] According to one embodiment of the present invention, it is possible to provide an effect of providing a novel curable resin composition that can provide a cured product that has an excellent balance between heat resistance and toughness when cured at low temperature.

[0012] 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 the respective configurations described below, and various modifications are possible within the scope of the claims. Furthermore, embodiments or examples obtained by combining the technical means disclosed in different embodiments or examples are also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. All academic literature and patent documents described in this specification are incorporated herein by reference. Furthermore, unless otherwise specified in this specification, the term "A to B" representing a numerical range means "greater than or equal to A (including and greater than A) and less than or equal to B (including and less than B)."

[0013] [1. Technical Concept of the Present Invention] In recent years, from the viewpoint of environmental friendliness, there has been a demand for curable resin compositions that can be cured at low temperatures and that can provide cured products having excellent physical properties even when cured at low temperatures.

[0014] From the viewpoint of enabling effectiveness at low temperatures, an amine-based epoxy curing agent can be selected as the epoxy curing agent. There are many types of amine-based epoxy curing agents. For example, linear aliphatic polyamines, polyether amines, amine-terminated butadiene nitrile rubbers, polyamidoamines which are modified linear aliphatic polyamines, and alicyclic amines (alicyclic polyamines) are available.

[0015] The present inventors have discovered the following in the course of investigating amine-based epoxy curing agents: (i) when triethylenetetraamine (TETA), a chain aliphatic polyamine, is used, the cured product has excellent heat resistance but poor toughness; and (ii) when polyetheramine is used, the cured product has excellent toughness but poor heat resistance.

[0016] Furthermore, the present inventors have discovered the following in the course of their investigations into polyamidoamines: (iii) When a certain amount or more of polyamidoamine is used as an epoxy curing agent and the active hydrogen equivalent of the epoxy curing agent is small, the cured product has excellent heat resistance but poor toughness; (iv) When a certain amount or more of polyamidoamine is used as an epoxy curing agent and the active hydrogen equivalent of the epoxy curing agent is large, the cured product has excellent toughness but poor heat resistance.

[0017] That is, it has been difficult to achieve both heat resistance and toughness.

[0018] The present inventors have also independently discovered the novel finding that, although a cured product obtained by curing at high temperatures using an alicyclic amine has excellent heat resistance and toughness, a cured product obtained by curing at low temperatures using an alicyclic amine surprisingly has poor toughness.

[0019] Therefore, the present inventors have conducted further intensive research with the aim of providing a curable resin composition that can provide a cured product that has an excellent balance between heat resistance and toughness when cured at low temperatures. As a result, the present inventors have independently discovered the following novel findings, which have led to the completion of the present invention: (1) The novel finding that a curable resin composition that contains a certain amount or more of an alicyclic amine as an epoxy curing agent and also contains an epoxy-based reactive diluent can surprisingly provide a cured product that has an excellent balance between heat resistance and toughness even when cured at low temperatures; (2) The novel finding that a curable resin composition that contains a certain amount or more of a polyamidoamine as an epoxy curing agent, the active hydrogen equivalent of the epoxy curing agent being within a specific range, and also contains an epoxy-based reactive diluent can surprisingly provide a cured product that has an excellent balance between heat resistance and toughness even when cured at low temperatures.

[0020] [2. Curable Resin Composition] A curable resin composition according to one embodiment of the present invention is a curable resin composition for low-temperature curing, and comprises the following components (A), (B), (C), and (D): component (A): an epoxy resin; component (B): one or more selected from the group consisting of the following components (b1), (b2), (b3), and (b4); component (b1): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (b2): blocked urethane; component (b3): ​​rubber-modified epoxy resin; component (b4): urethane-modified epoxy resin; component (C): epoxy curing agent; component (D): epoxy-based reactive diluent; and satisfies the following (1) and / or (2): (1) the component (C) comprises the following component (c1): component (c1): alicyclic amine; the content of the component (c1) is 25% by mass to 100% by mass relative to 100% by mass of the component (C); (2) The component (C) includes the following component (c2): component (c2) is a polyamidoamine; the active hydrogen equivalent of the component (C) is 50 g / eq to 90 g / eq, and the content of the component (c2) is 25% by mass to 100% by mass relative to 100% by mass of the component (C).

[0021] In this specification, the term "curable resin composition" may be referred to as "composition," and the term "curable resin composition according to one embodiment of the present invention" may be referred to as "the composition."

[0022] The present composition has the above-described structure, and therefore has the advantage that when cured at low temperatures, it can provide a cured product that has an excellent balance between heat resistance and toughness.

[0023] In this specification, a "cured product having an excellent balance between heat resistance and toughness" is intended to mean a cured product that satisfies one or more of the following (i-1) and (i-2) and one or more of the following (ii-1), (ii-2), (ii-3), and (ii-4): (i-1) A glass transition temperature (Tg), which is an index of heat resistance, of 80°C or higher; (i-2) A storage modulus at 70°C, which is an index of heat resistance, of 0.14 GPa or higher; (ii-1) A fracture toughness (K1c), which is an index of toughness, of 1.10 MPa m １／２ (ii-2) The shear bond strength, which is an index of toughness, is 18 MPa or more; (ii-3) The T-peel bond strength, which is an index of toughness, is 100 N / 25 mm or more; (ii-4) The impact peel strength, which is an index of toughness, is 17 kN / m or more.

[0024] <2-1. Component (A): Epoxy Resin> The present composition contains an epoxy resin as component (A). In this specification, the term "epoxy resin" refers to a resin having at least one epoxy group per molecule. The epoxy resin as component (A) is preferably a resin having two or more epoxy groups per molecule.

[0025] In this specification, "rubber-modified epoxy resins" and "urethane-modified epoxy resins" are not included in component (A), but are included in component (B). Furthermore, "epoxy resins having a viscosity of 500 mPa·s or less at 25°C" are sometimes referred to as "epoxy-based reactive diluents." In this specification, "epoxy resins having a viscosity of 500 mPa·s or less at 25°C," i.e., "epoxy-based reactive diluents," are not included in component (A), but are referred to as component (D). In other words, component (A) can also be referred to as "epoxy resins other than components (B) and (D)" or "epoxy resins other than component (B) that have a viscosity of more than 500 mPa·s at 25°C."

[0026] A resin having X epoxy groups per molecule is sometimes referred to as an "X-functional epoxy resin." For example, a resin having one epoxy group per molecule is called a "monofunctional epoxy resin," and a resin having two epoxy groups per molecule is called a "difunctional epoxy resin." Furthermore, a resin having two or more epoxy groups per molecule is sometimes called a "multifunctional epoxy resin."

[0027] Various epoxy resins can be used as the epoxy resin, 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, novolac 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 resin such as glycidyl ether of tetrabromobisphenol A, p-oxybenzoic acid glycidyl ether ester type epoxy resin, resins, m-aminophenol type epoxy resins, diaminodiphenylmethane type epoxy resins, various alicyclic epoxy resins, N,N-diglycidylaniline, N,N-diglycidyl-o-toluidine, triglycidyl isocyanurate, divinylbenzene dioxide, resorcinol diglycidyl ether, chelate-modified epoxy resins, hydantoin type epoxy resins, epoxidized products of unsaturated polymers such as petroleum resins, aminoglycidyl ether resins, and epoxy compounds obtained by addition reaction of the above epoxy resins with bisphenol A (or F) or polybasic acids, etc.

[0028] Examples of commercially available bisphenol A type epoxy resins include those commercially available under the trade name jER from Mitsubishi Chemical Corporation (e.g., jER828, jER825, jER827, jER828EL, jER828US, jER828XA, jER834, jER1001, jER1002, jER1004, jER1007, jER1009, jER1010), and those commercially available under the trade name jER from Momentive Specialty Chemicals, Inc. those commercially available under the trade name EPON from Olin Epoxy Co. (e.g., EPON 1510, EPON 1310, EPON 828, EPON 872, EPON 1001, EPON 1004, EPON 2004); Examples of suitable resins include, but are not limited to, resins commercially available under the trade name DER from Epson Corporation (e.g., DER 331, DER 332, DER 336, and DER 439), resins commercially available under the trade name ADEKA RESIN from ADEKA Corporation (e.g., EP-4100, EP-4300, EP-4400, EP-4530, and EP-4504), and resins commercially available under the trade name EPICLON from DIC Corporation (e.g., EPICLON 840 and EPICLON 850).

[0029] Examples of commercially available bisphenol F epoxy resins include, but are not limited to, those commercially available under the trade name jER from Mitsubishi Chemical Corporation (e.g., jER806, jER806H, jER807, jER4005P, jER4007P, jER4010P), those commercially available under the trade name DER from Olin Epoxy Co. (e.g., DER 334), those commercially available under the trade name ADEKA RESIN from ADEKA Corporation (e.g., EP-4901, EP-4901E), and those commercially available under the trade name EPICLON from DIC Corporation (e.g., EPICLON 830).

[0030] Alicyclic epoxy resins are compounds containing (i) one or more saturated or unsaturated aliphatic hydrocarbon rings and (ii) one or more epoxy groups in the molecule, and also include epoxy resins containing a cycloalkane ring. Examples of alicyclic epoxy resins include 3,4-epoxycyclohexylmethyl (3,4-epoxy)cyclohexanecarboxylate, tetrahydroindene diepoxide, vinylcyclohexene oxide, dipentene dioxide, bis(3,4-epoxycyclohexylmethyl) adipate, dicyclopentadiene dioxide, bis(2,3-epoxycyclopentyl)ether, 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, and epoxidized butanetetracarboxylic acid tetrakis. Examples of suitable epoxy resins include bis-(3-cyclohexenylmethyl)-modified epsilon-caprolactone, bi-7-oxabicyclo[4.1.0]heptane, dodecahydrobisphenol A diglycidyl ether, dodecahydrobisphenol F diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, hexahydrophthalic acid diglycidyl ester, hexahydroterephthalic acid diglycidyl ester, and diglycidyl ether of 2,2-bis(4-hydroxycyclohexyl)propane (generic name: hydrogenated bisphenol A liquid epoxy resin). The alicyclic epoxy resin preferably contains one or more selected from the group consisting of 3,4-epoxycyclohexylmethyl (3,4-epoxy)cyclohexanecarboxylate, 1,2-epoxy-4-(2-oxiranyl)cyclohexane adduct of 2,2-bis(hydroxymethyl)-1-butanol, epoxidized butanetetracarboxylic acid tetrakis-(3-cyclohexenylmethyl)-modified epsilon-caprolactone, and diglycidyl ether of 2,2-bis(4-hydroxycyclohexyl)propane, more preferably consisting of only one or more selected from this group, more preferably containing diglycidyl ether of 2,2-bis(4-hydroxycyclohexyl)propane, and even more preferably consisting of diglycidyl ether of 2,2-bis(4-hydroxycyclohexyl)propane.This composition has the advantages of having low viscosity and excellent processability, and furthermore, the cured product obtained by curing the composition has excellent strength, elastic modulus, and heat resistance (high Tg). The elastic modulus of the cured product can be, for example, the storage modulus.

[0031] Examples of epoxy compounds obtained by subjecting an epoxy resin to an addition reaction with a polybasic acid or the like include an addition reaction product of a dimer of tall oil fatty acid (dimer acid) with a bisphenol A-type epoxy resin, as described in WO 2010-098950.

[0032] As the chelate-modified epoxy resin, for example, the resins described in paragraphs

[0018] to

[0019] of WO2016-163491 can be used.

[0033] The epoxy resin is not limited to these, and any commonly used epoxy resin may be used. These epoxy resins may be used alone or in combination of two or more.

[0034] Among these epoxy resins, polyfunctional epoxy resins having at least two epoxy groups per molecule have high curability, produce highly flexible cured products, and are excellent in improving the toughness of the cured products by incorporating polymer particles, which will be described later. Furthermore, among polyfunctional epoxy resins, bifunctional epoxy resins produce cured products with high strength and an excellent balance between elastic modulus and elongation. Therefore, component (A) preferably contains a polyfunctional epoxy resin, more preferably consists solely of a polyfunctional epoxy resin, more preferably contains a bifunctional epoxy resin, and even more preferably is (consists solely of) a bifunctional epoxy resin.

[0035] The epoxy equivalent of the epoxy resin is preferably less than 220 g / eq, more preferably from 90 g / eq to less than 210 g / eq, and even more preferably from 135 g / eq to less than 200 g / eq. This configuration has the advantage of being able to obtain a cured product with high elastic modulus and heat resistance.

[0036] In this specification, the term "epoxy equivalent" refers to the molecular weight per epoxy group contained in a compound having an epoxy group, and specifically, is a value calculated based on the following formula: Epoxy equivalent (g / eq) = mass average molecular weight (Mw) of compound / number of epoxy groups per molecule of compound (average number). The epoxy equivalent can also be measured in accordance with JIS K7236.

[0037] In this specification, bisphenol A epoxy resins are also referred to as component (a1), and bisphenol F epoxy resins are also referred to as component (a2). Among the above-mentioned epoxy resins, the bisphenol A epoxy resin (component (a1)) and the bisphenol F epoxy resin (component (a2)) produce cured products with high elastic modulus, excellent heat resistance and adhesion, and are relatively inexpensive. For this reason, component (A) preferably contains component (a1) and / or component (a2), and more preferably is component (a1) and / or component (a2) (i.e., is composed exclusively of component (a1) and / or component (a2)). Furthermore, because a curable resin composition capable of providing a cured product with excellent heat resistance can be obtained at a low cost, component (A) more preferably contains component (a1), and is particularly preferably is component (a1) (i.e., is composed exclusively of component (a1)).

[0038] In this specification, the difunctional bisphenol A epoxy resin is also referred to as component (a1'), and the difunctional bisphenol F epoxy resin is also referred to as component (a2'). From the viewpoints of the balance between elastic modulus and elongation, and strength, the component (A) preferably contains the component (a1') and / or the component (a2'), and more preferably is the component (a1') and / or the component (a2') (i.e., is composed only of the component (a1') and / or the component (a2')).

[0039] From the viewpoints of the balance between elastic modulus and elongation, and strength, the present composition preferably contains a smaller amount of tri- or higher functional epoxy resin as component (A). In the present composition, the total amount of tri- or higher functional epoxy resins per 100% by mass of component (A) is preferably 40% by mass or less, more preferably 20% by mass or less, even more preferably 10% by mass or less, and particularly preferably 0% to 5% by mass. In the present composition, the total amount of tri- or higher functional epoxy resins per 100% by mass of component (A) may be 0% by mass. In other words, the present composition does not need to contain a tri- or higher functional epoxy resin as component (A).

[0040] The total content of the (a1) and (a2) components in 100% by mass of the (A) component is preferably 5% to 100% by mass, more preferably 10% to 100% by mass, more preferably 20% to 100% by mass, more preferably 30% to 100% by mass, more preferably 40% to 100% by mass, more preferably 50% to 100% by mass, more preferably 60% to 100% by mass, more preferably 70% to 100% by mass, more preferably 80% to 100% by mass, even more preferably 90% to 100% by mass, and even more preferably 95% to 100% by mass. This configuration has the advantage that the resulting cured product has superior toughness, impact resistance, heat resistance, and adhesiveness. The total content of the (a1) and (a2) components in 100% by mass of the (A) component may be 100% by mass. In other words, the component (A) may be the component (a1) and / or the component (a2) (or may consist solely of the component (a1) and / or the component (a2)).

[0041]

[0042] The total content of components (a1') and (a2') in 100% by mass of component (A) is preferably 5% by mass to 100% by mass, more preferably 10% by mass to 100% by mass, more preferably 20% by mass to 100% by mass, more preferably 30% by mass to 100% by mass, more preferably 40% by mass to 100% by mass, more preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, more preferably 80% by mass to 100% by mass, even more preferably 90% by mass to 100% by mass, and even more particularly preferably 95% by mass to 100% by mass. This configuration provides a cured product having (i) superior toughness, impact resistance, heat resistance, and adhesion, and (ii) an excellent balance between modulus and elongation. The total content of component (a1') and component (a2') may be 100% by mass based on 100% by mass of component (A). In other words, component (A) may consist of component (a1') and / or component (a2') (or may be composed solely of component (a1') and / or component (a2')).

[0042] In this specification, a bisphenol A epoxy resin having an epoxy equivalent of less than 220 g / eq is also referred to as component (a1"), and a bisphenol F epoxy resin having an epoxy equivalent of less than 220 g / eq is also referred to as component (a2"). In addition, in this specification, a bifunctional bisphenol A epoxy resin having an epoxy equivalent of less than 220 g / eq is also referred to as component (a1'"), and a bifunctional bisphenol F epoxy resin having an epoxy equivalent of less than 220 g / eq is also referred to as component (a2'").

[0043] Both the bisphenol A epoxy resin (a1") having an epoxy equivalent of less than 220 g / eq and the bisphenol F epoxy resin (a2") having an epoxy equivalent of less than 220 g / eq are liquid at room temperature and have excellent handleability. Therefore, it is more preferable that the component (A) contains the component (a1") and / or the component (a2"). Furthermore, from the viewpoints of the balance between elastic modulus and elongation, and strength, it is particularly preferable that the component (A) contains the component (a1'") and / or the component (a2'").

[0044] The total content of components (a1'') and (a2'') in 100% by mass of component (A) is preferably 5% by mass to 100% by mass, more preferably 10% by mass to 100% by mass, more preferably 20% by mass to 100% by mass, more preferably 30% by mass to 100% by mass, more preferably 40% by mass to 100% by mass, more preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, more preferably 80% by mass to 100% by mass, even more preferably 90% by mass to 100% by mass, and even more particularly preferably 95% by mass to 100% by mass. This configuration has the following advantages: (i) the resulting cured product has superior toughness, impact resistance, heat resistance, and adhesion, and (ii) the composition has superior handleability. The total content of the component (a1'') and the component (a2'') may be 100% by mass, where 100% by mass of the component (A) is 100% by mass. In other words, the component (A) may be the component (a1'') and / or the component (a2'') (or may be composed solely of the component (a1'') and / or the component (a2'').

[0045] In 100% by mass of component (A), the total content of component (a1''') and component (a2''') is preferably 5% by mass to 100% by mass, more preferably 10% by mass to 100% by mass, more preferably 20% by mass to 100% by mass, more preferably 30% by mass to 100% by mass, more preferably 40% by mass to 100% by mass, more preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, more preferably 80% by mass to 100% by mass, even more preferably 90% by mass to 100% by mass, and even more particularly preferably 95% by mass to 100% by mass. This configuration has the following advantages: (i) the resulting cured product has excellent toughness, impact resistance, heat resistance, and adhesion; (ii) the composition has excellent handleability; and (iii) the composition has an excellent balance between elastic modulus and elongation. The total content of components (a1''') and (a2''') in 100 mass% of component (A) may be 100 mass%. In other words, component (A) may be component (a1''') and / or component (a2''') (or may be composed only of component (a1''') and / or component (a2''').

[0046] From the viewpoint of toughness, the content of component (A) in 100% by mass of the total amount of components (A) to (D) is preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, and even more preferably 30% by mass to 80% by mass.

[0047] <2-2. Component (B)> The present composition includes, as component (B), one or more selected from the group consisting of polymer particles having a core-shell structure including a core layer and a shell layer (component (b1)), a blocked urethane (component (b2)), a rubber-modified epoxy resin (component (b3)), and a urethane-modified epoxy resin (component (b4)). The present composition may include, as component (B), at least component (b1), component (b2), component (b3), or component (b4). The present composition does not necessarily include, as component (B), all of component (b1), component (b2), component (b3), and component (b4).

[0048] [Component (b1): Polymer Particles] In this specification, "polymer particles having a core-shell structure comprising a core layer and a shell layer" refers to particles in which a core layer made of a core polymer and a shell layer made of a shell polymer form a layer structure. In this specification, "polymer particles having a core-shell structure comprising a core layer and a shell layer" may also be referred to as "core-shell polymer particles" or simply "polymer particles."

[0049] When the present composition contains polymer particles (b1) as component (B), the polymer particles can exhibit a toughness-improving effect in the composition. As a result, by including polymer particles as component (B), the present composition has the advantage of being able to provide a cured product (e.g., adhesive layer) with excellent toughness even when cured at low temperatures. Furthermore, when the present composition contains polymer particles as component (B), the adhesive strength (e.g., impact peel strength) of the resulting cured product tends to be excellent.

[0050] The polymer particles can be obtained by graft polymerizing a graft-copolymerizable monomer (a monomer for forming a shell layer) in the presence of a core layer to form a shell layer. More specifically, this polymerization operation can be carried out by adding a monomer for forming a shell layer (shell polymer) to a latex of a core polymer prepared in an aqueous polymer latex state and polymerizing it. In the polymer particles, it is preferable that the core polymer and the shell polymer are substantially chemically bonded. Note that in the polymer particles, the core layer and the shell layer do not need to form a complete layer structure. The shell layer (shell polymer) only needs to cover at least a portion of the core layer (core polymer), and does not need to cover the entire core layer. Furthermore, a portion of the shell layer may penetrate into the core layer.

[0051] Each layer of the polymer particles will be specifically described below.

[0052] <<Core Layer>> The core layer is preferably an elastic core layer having rubber properties in order to enhance the toughness of the cured product of the composition.

[0053] The core layer preferably contains a diene rubber because it provides a high toughness-improving effect on the resulting cured product, a high impact peel strength-improving effect on the resulting cured product, and is less likely to experience an increase in viscosity over time due to swelling of the core layer due to its low affinity with component (A). The core layer preferably contains a (meth)acrylate rubber because a wide range of polymer compositions can be designed by combining a variety of monomers. Furthermore, when attempting to improve low-temperature impact resistance without reducing the heat resistance of the cured product, the core layer preferably contains an organosiloxane rubber. In other words, the core layer of the polymer particles, which are component (b1), preferably contains one or more rubbers selected from the group consisting of diene rubbers, (meth)acrylate rubbers, and organosiloxane rubbers.

[0054] (Diene Rubber) The diene rubber is preferably a polymer containing 50% by mass to 100% by mass of conjugated diene units and 0% by mass to 50% by mass of structural units derived from vinyl monomers other than conjugated diene monomers copolymerizable with the conjugated diene monomers.

[0055] Examples of the conjugated diene monomer from which the conjugated diene units are derived include 1,3-butadiene, isoprene (2-methyl-1,3-butadiene), and 2-chloro-1,3-butadiene.

[0056] These conjugated diene monomers may be used alone or in combination of two or more.

[0057] The content of conjugated diene units in the core layer (e.g., diene rubber) is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, and even more preferably 90% by mass to 100% by mass, based on 100% by mass of all structural units constituting the core layer. When the content of conjugated diene units in the core layer (e.g., diene rubber) is 50% by mass or more, the toughness of the resulting cured product can be improved.

[0058] Examples of vinyl monomers other than conjugated diene monomers copolymerizable with conjugated diene monomers include vinyl arenes such as styrene, α-methylstyrene, monochlorostyrene, and dichlorostyrene; vinyl carboxylic acids such as acrylic acid and methacrylic acid; vinyl cyanides such as acrylonitrile and methacrylonitrile; vinyl halides such as vinyl chloride, vinyl bromide, and chloroprene; vinyl acetate; alkenes such as ethylene, propylene, butylene, and isobutylene; and polyfunctional monomers such as diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, and divinylbenzene.

[0059] These vinyl monomers may be used alone or in combination of two or more. As the vinyl monomer other than the conjugated diene monomer copolymerizable with the conjugated diene monomer, styrene is particularly preferred.

[0060] From the viewpoints of a higher toughness-improving effect of the resulting cured product, a higher improvement effect in Impact Peel strength of the resulting cured product, and a lower affinity with component (A) such that an increase in viscosity over time due to swelling of the core layer is less likely to occur, the core layer of the polymer particles of component (b1) preferably contains, among diene rubbers, butadiene rubber, which is a homopolymer of 1,3-butadiene, and / or butadiene-styrene rubber, which is a copolymer of 1,3-butadiene and styrene, more preferably (consisting only of) butadiene rubber and / or butadiene-styrene rubber, even more preferably containing butadiene rubber, and particularly preferably (consisting only of) butadiene rubber. Furthermore, butadiene-styrene rubber is preferred because it can enhance the transparency of the resulting cured product by adjusting the refractive index.

[0061] ((Meth)acrylate Rubber) The (meth)acrylate rubber is preferably a polymer obtained by polymerizing a monomer mixture containing 50% by mass to 100% by mass of (meth)acrylate units and 0% by mass to 50% by mass of structural units derived from vinyl monomers other than (meth)acrylate monomers that are copolymerizable with the (meth)acrylate monomers. In this specification, "(meth)acrylate" means acrylate and / or methacrylate.

[0062] Examples of the (meth)acrylate monomer from which the (meth)acrylate unit is derived include: (i) alkyl (meth)acrylates 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 behenyl (meth)acrylate; (ii) aromatic ring-containing (meth)acrylates such as phenoxyethyl (meth)acrylate and benzyl (meth)acrylate; and (iii) hydroxyalkanol (meth)acrylates 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 behenyl (meth)acrylate. (iv) glycidyl (meth)acrylates such as glycidyl (meth)acrylate and glycidyl alkyl (meth)acrylate; (v) alkoxyalkyl (meth)acrylates; (vi) allyl alkyl (meth)acrylates such as allyl (meth)acrylate and allyl alkyl (meth)acrylate; (vii) polyfunctional (meth)acrylates such as monoethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and the like.

[0063] Examples of hydroxyalkyl (meth)acrylates include hydroxy linear alkyl (meth)acrylates (particularly, hydroxy linear C1-6 alkyl (meth)acrylates) such as 2-hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; caprolactone-modified hydroxy (meth)acrylates; hydroxy branched alkyl (meth)acrylates such as methyl α-(hydroxymethyl)acrylate and ethyl α-(hydroxymethyl)acrylate; and hydroxyl group-containing (meth)acrylates such as mono(meth)acrylates of polyester diols (particularly saturated polyester diols) obtained from divalent carboxylic acids (such as phthalic acid) and dihydric alcohols (such as propylene glycol).

[0064] These (meth)acrylate monomers may be used alone or in combination of two or more. The (meth)acrylate unit is preferably at least one selected from the group consisting of an ethyl (meth)acrylate unit, a butyl (meth)acrylate unit, and a 2-ethylhexyl (meth)acrylate unit.

[0065] Examples of vinyl monomers other than (meth)acrylate monomers copolymerizable with (meth)acrylate monomers include (i) vinyl arenes such as styrene, α-methylstyrene, monochlorostyrene, and dichlorostyrene; (ii) vinyl carboxylic acids such as acrylic acid and methacrylic acid; (iii) vinyl cyanides such as acrylonitrile and methacrylonitrile; (iv) vinyl halides such as vinyl chloride, vinyl bromide, and chloroprene; (v) vinyl acetate; (vi) alkenes such as ethylene, propylene, butylene, and isobutylene; and (vii) polyfunctional monomers such as diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, and divinylbenzene.

[0066] The vinyl monomer other than the (meth)acrylate monomer copolymerizable with the (meth)acrylate monomer may be used alone or in combination of two or more. Styrene is particularly preferred as the vinyl monomer other than the (meth)acrylate monomer copolymerizable with the (meth)acrylate monomer, since it can easily increase the refractive index.

[0067] (Organosiloxane-Based Rubber) Examples of the organosiloxane-based rubber include (i) polysiloxane-based polymers composed of alkyl or aryl di-substituted silyloxy units, such as dimethylsilyloxy, diethylsilyloxy, methylphenylsilyloxy, diphenylsilyloxy, and dimethylsilyloxy-diphenylsilyloxy; and (ii) polysiloxane-based polymers composed of alkyl or aryl mono-substituted silyloxy units, such as organohydrogensilyloxy in which some of the alkyl groups in the side chains are substituted with hydrogen atoms.

[0068] These polysiloxane polymers may be used alone or in combination of two or more. Among these, dimethylsilyloxy, methylphenylsilyloxy, and dimethylsilyloxy-diphenylsilyloxy are preferred because they can impart heat resistance to the cured product, and dimethylsilyloxy is most preferred because it is easily available.

[0069] 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, even more preferably -40°C or lower, and particularly preferably -60°C or lower, in order to enhance the toughness of the resulting cured product.

[0070] The volume average particle diameter of the core layer is not particularly limited, but is preferably 0.03 μm to 2.00 μm, more preferably 0.05 μm to 1.00 μm, more preferably 0.12 μm to 0.50 μm, more preferably 0.12 μm to 0.28 μm, and even more 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 produced stably, and the cured product can have good heat resistance and toughness. The method for measuring the volume average particle diameter of the core layer will be described in detail in the Examples below.

[0071] The core layer may have a single layer structure or a multilayer structure consisting of multiple layers each having rubber elasticity. When the core layer has a multilayer structure, the polymer compositions of the layers may be different from each other within the ranges disclosed above.

[0072] The composition of the structural units of the core layer depends on the composition of the monomer for forming the core layer. When the polymerization conversion rate is 100%, the obtained core layer contains structural units derived from all of the monomers contained in the monomer for forming the core layer.

[0073] In one embodiment of the present invention, an intermediate layer, for example, as described in paragraphs

[0046] to

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

[0074] <Shell Layer> The shell layer is a polymer obtained by polymerizing a monomer for forming the shell layer. The polymer constituting the shell layer (shell polymer) plays a role of improving the compatibility between the polymer particles and component (A) and enabling the polymer particles to be dispersed in the form of primary particles in the composition and / or a cured product of the composition.

[0075] The type and content ratio of the structural unit contained in the shell layer are not particularly limited. In terms of compatibility and dispersibility of the polymer particles in the composition, the shell layer of the polymer particles (b1) preferably contains one or more structural units selected from the group consisting of aromatic vinyl units, vinylcyan units, and (meth)acrylate units, more preferably contains a (meth)acrylate unit, and particularly preferably contains a methyl methacrylate unit.

[0076] The composition of the structural units of the shell layer depends on the composition of the monomer for forming the shell layer. When the polymerization conversion rate is 100%, the obtained shell layer contains structural units derived from all of the monomers contained in the monomer for forming the shell layer.

[0077] The total content of one or more structural units selected from the group consisting of aromatic vinyl units, vinylcyan units, and (meth)acrylate units in the shell layer is preferably 10.0% by mass to 99.5% by mass, more preferably 50.0% by mass to 99.0% by mass, even more preferably 65.0% by mass to 98.0% by mass, particularly preferably 67.0% by mass to 80.0% by mass, and most preferably 67.0% by mass to 85.0% by mass, based on 100% by mass of the shell layer (shell polymer).

[0078] Specific examples of the aromatic vinyl monomer from which the aromatic vinyl unit is derived include vinylbenzenes such as styrene, α-methylstyrene, p-methylstyrene, and divinylbenzene.

[0079] Specific examples of the vinylcyanide monomer from which the vinylcyanide unit is derived include acrylonitrile and methacrylonitrile.

[0080] Specific examples of the (meth)acrylate monomers from which the (meth)acrylate units are derived are the same as those described in the section "Core Layer" above, and therefore, the description therein is incorporated by reference and will not be repeated here.

[0081] In order to maintain a good dispersion state without aggregation of the polymer particles in the cured product and the composition, it is preferable to chemically bond the polymer particles to the component (A). In order to chemically bond the polymer particles to the component (A), it is preferable that the shell layer has a structural unit derived from a reactive group-containing monomer. In other words, it is preferable that the shell layer contains a reactive group.

[0082] The reactive group is preferably at least one selected from the group consisting of, for example, an epoxy group, an oxetane 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 benzoxazine group, and a cyanate ester group.

[0083] 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, preferably has an epoxy group. When the shell layer of the polymer particle has an epoxy group, the composition has excellent storage stability, and has the advantage that a cured product having excellent toughness can be provided even when the composition is cured at a low temperature.

[0084] Specific examples of the monomer having an epoxy group include glycidyl group-containing vinyl monomers such as glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, and allyl glycidyl ether.

[0085] When the shell layer of the polymer particle has epoxy groups, the content (mmol) of epoxy groups in the shell layer relative to the total mass (g) of the shell layer of the polymer particle is preferably more than 0 mmol / g and not more than 2.0 mmol / g, more preferably 0.1 mmol / g to 2.0 mmol / g, and even more preferably 0.3 mmol / g to 1.5 mmol / g. This configuration suppresses aggregation of the polymer particles, allowing the polymer particles to be dispersed in the cured product in the state of primary particles, and as a result, it is presumed that the toughness of the cured product can be improved even when cured at low temperatures.

[0086] The monomer having an epoxy group is preferably used to form the shell layer, and more preferably used only to form the shell layer. In other words, it is preferable that the core layer and the intermediate layer do not have an epoxy group.

[0087] From the viewpoint of storage stability of the composition, it is preferable that the shell layer of the polymer particle does not have an epoxy group.

[0088] Specific examples of the reactive group-containing monomer having a hydroxyl group include the above-mentioned hydroxyalkyl (meth)acrylates.

[0089] 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 in the composition is prevented, and the composition tends to have a low viscosity and good handleability. Therefore, it is preferable that the shell layer contains a structural unit derived from the polyfunctional monomer. On the other hand, from the viewpoint of excellent effects of improving the toughness and impact peel strength of the resulting cured product, it is preferable that the shell layer does not contain a structural unit derived from the polyfunctional monomer.

[0090] Specific examples of the polyfunctional monomer do not include conjugated diene monomers such as butadiene, and include allyl alkyl (meth)acrylates such as allyl (meth)acrylate and allyl alkyl (meth)acrylate; allyloxyalkyl (meth)acrylates; polyfunctional (meth)acrylates having two or more (meth)acrylic groups such as (poly)ethylene glycol di(meth)acrylate, butanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, and tetraethylene glycol di(meth)acrylate; diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, and divinylbenzene.

[0091] Among these polyfunctional monomers, allyl methacrylate and triallyl isocyanurate are preferred.

[0092] The shell layer is preferably a polymer composed only of the following structural units: (a) aromatic vinyl units (particularly preferably styrene units) 0% to 50% by mass (preferably 0% to 35% by mass, more preferably 0% to 20% by mass), (b) vinylcyan units (particularly preferably acrylonitrile units) 0% to 50% by mass (preferably 0% to 30% by mass, more preferably 0% to 20% by mass), (c) (meth)acrylate units ((i) preferably one or more structural units selected from the group consisting of methyl acrylate units, butyl acrylate units, and methyl methacrylate units, (ii) particularly preferably methyl methacrylate units) 0% to 100% by mass (preferably 5% to 100% by mass, more preferably 70% to 95% by mass), and (d) structural units derived from a monomer having an epoxy group (particularly glycidyl methacrylate units) 0% to 50% by mass (preferably 1% to 35% by mass, more preferably 3% to 20% by mass). However, (i) the total of the aromatic vinyl-based units, vinylcyan-based units, (meth)acrylate-based units, and structural units derived from monomers having an epoxy group is 100% by mass, and (ii) 0% by mass means that the structural units may not be included.

[0093] The above-mentioned monomer components may be used alone or in combination of two or more. The shell layer may contain a structural unit derived from a monomer other than the above-mentioned monomers.

[0094] The shell layer may have a single layer structure or a multi-layer structure, and when the shell layer has a multi-layer structure, the polymer compositions of the layers may be different from each other within the ranges disclosed above.

[0095] <Volume average particle diameter (Mv) of polymer particles> The volume average particle diameter (Mv) of the polymer particles is not particularly limited, but from the viewpoint of industrial productivity and workability of the curable resin composition, it is preferably 0.01 μm to 2.00 μm, more preferably 0.02 μm to 1.00 μm, more preferably 0.03 μm to 0.60 μm, more preferably 0.05 μm to 0.40 μm, more preferably 0.10 μm to 0.30 μm, more preferably 0.15 μm to 0.30 μm, more preferably 0.16 μm to 0.28 μm, more preferably 0.17 μm to 0.27 μm, and even more preferably 0.18 μm to 0.25 μm. When the volume average particle diameter (Mv) of the polymer particles is (a) 0.01 μm or more, the viscosity of the composition is reduced, which is advantageous in that workability is improved, and when it is (b) 2.00 μm or less, the polymerization time of the polymer particles is shortened, which is advantageous in that industrial productivity is increased. The method for measuring the volume average particle diameter (Mv) of the polymer particles will be described in detail in the Examples below.

[0096] When the composition contains polymer particles as component (B), the polymer particles are preferably dispersed in the composition in the form of primary particles. In this specification, "polymer particles dispersed in the form of primary particles" (hereinafter also referred to as "primary dispersion") means that the polymer particles are dispersed substantially independently (without contact) with each other. The dispersion state of the polymer particles in the composition can be confirmed, for example, by mixing a portion of the composition with a solvent such as methyl ethyl ketone, subjecting the resulting mixture to a particle size measurement device using laser light scattering, or the like, and measuring the particle size of the polymer particles in the mixture.

[0097] Furthermore, the term "stable dispersion" of polymer particles means a state in which the polymer particles are dispersed steadily under normal conditions for a long period of time without agglomeration, separation, or precipitation in the continuous layer. It is also preferable that the distribution of the polymer particles in the continuous layer does not change substantially, and that the "stable dispersion" can be maintained even when the composition is heated within a safe range to reduce the viscosity and stirred.

[0098] The polymer particles may be used alone or in combination of two or more kinds.

[0099] <<Method for Producing Polymer Particles>> (Method for Producing Core Layer) The core layer constituting the polymer particles can be formed by, for example, emulsion polymerization, suspension polymerization, microsuspension polymerization, etc. As the methods such as emulsion polymerization, suspension polymerization, and microsuspension polymerization, for example, the methods described in WO 2005 / 028546 and WO 2006 / 070664 can be appropriately used.

[0100] (Method for forming shell layer and intermediate layer) When the polymer particles include an intermediate layer, the intermediate layer can be formed by polymerizing a monomer for forming the intermediate layer by known radical polymerization. When the rubber elastic material constituting the core layer is obtained as an emulsion, it is preferable to polymerize the monomer for forming the intermediate layer by emulsion polymerization.

[0101] The shell layer can be formed by polymerizing a monomer for forming the shell layer by known radical polymerization. When the core layer or the polymer particle precursor formed by coating the core layer with an intermediate layer is obtained as an emulsion, the polymerization of the monomer for forming the shell layer is preferably carried out by emulsion polymerization. For example, the method described in WO 2005 / 028546 can be appropriately used as the emulsion polymerization method.

[0102] In emulsion polymerization, an emulsifier (dispersant) is used.

[0103] Examples of the emulsifier include (i) (i-1) various acids such as alkyl or aryl sulfonic acids typified by dioctylsulfosuccinic acid and dodecylbenzenesulfonic acid; alkyl or aryl ether sulfonic acids; alkyl or aryl sulfuric acids typified by dodecyl sulfate; alkyl or aryl ether sulfuric acids; alkyl or aryl substituted phosphoric acids; alkyl or aryl ether substituted phosphoric acids; N-alkyl or aryl sarcosinic acids typified by dodecyl sarcosinic acid; alkyl or aryl carboxylic acids typified by oleic acid and stearic acid; and alkyl or aryl ether carboxylic 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 glycol, and (iii) dispersants such as polyvinyl alcohol, alkyl substituted cellulose, polyvinylpyrrolidone, and polyacrylic acid derivatives.

[0104] These emulsifiers (dispersants) may be used alone or in combination of two or more.

[0105] It is preferable to use a small amount of emulsifier (dispersant) as long as it does not impair the dispersion stability of the aqueous latex of polymer particles. Furthermore, the higher the water solubility of the emulsifier (dispersant), the more preferable it is. High water solubility makes it easier to wash off the emulsifier (dispersant) with water, and can easily prevent adverse effects on the final cured product.

[0106] When emulsion polymerization is employed, peroxides (for example, organic peroxides), chain transfer agents, surfactants, and the like may be used as needed.

[0107] The polymerization conditions such as polymerization temperature, pressure, deoxidation, etc., may be within known ranges.

[0108] The present composition preferably contains at least polymer particles as component (B), as this provides an excellent balance between the storage stability of the resulting composition and the toughness-improving effect and impact peel strength of the resulting cured product.

[0109] When the composition contains polymer particles as component (B), the content of the polymer particles in the composition is preferably 1 to 100 parts by mass, more preferably 5 to 90 parts by mass, even more preferably 10 to 80 parts by mass, even more preferably 20 to 70 parts by mass, and particularly preferably 30 to 60 parts by mass, per 100 parts by mass of component (A). This configuration has the advantage of providing an excellent balance between the storage stability of the resulting composition and the toughness-improving effect and Impact Peel strength of the resulting cured product.

[0110] [Component (b2): Blocked Urethane] In this specification, the term "blocked urethane" refers to an "elastomeric compound containing a urethane group and / or a urea group and having terminal isocyanate groups," in which all or some of the terminal isocyanate groups have been capped with various blocking agents having active hydrogen groups. The compound capped with a blocking agent, i.e., the blocked urethane itself, may be an elastomer. As the blocked urethane, a compound in which all of the terminal isocyanate groups have been capped with a blocking agent is particularly preferred. Blocked urethanes can be obtained, for example, by the following methods: (A) (A-1) reacting an organic polymer having an active hydrogen-containing group at its terminal with an excess of a polyisocyanate compound to obtain a polymer (urethane prepolymer) having urethane groups and / or urea groups in the main chain and isocyanate groups at its terminal; (A-2) subsequently capping all or some of the isocyanate groups with a blocking agent having an active hydrogen group; or (B) reacting an organic polymer having an active hydrogen-containing group at its terminal with an excess of a polyisocyanate compound and simultaneously reacting it with a blocking agent, thereby capping all or some of the isocyanate groups of the urethane prepolymer with the blocking agent having an active hydrogen group.

[0111] Specific examples of blocked urethanes include compounds described in WO 2016 / 163491.

[0112] The number average molecular weight of the blocked urethane, in terms of polystyrene equivalent molecular weight measured by GPC, is preferably 2,000 to 40,000, more preferably 3,000 to 30,000, and particularly preferably 4,000 to 20,000. The molecular weight distribution (weight average molecular weight / number average molecular weight) of the blocked urethane is preferably 1.0 to 4.0, more preferably 1.2 to 3.0, and particularly preferably 1.5 to 2.5.

[0113] The blocked urethane may be used alone or in combination of two or more.

[0114] From the viewpoint of improving the toughness, impact resistance, and adhesive properties (for example, impact peel strength) of the resulting cured product, the present composition preferably contains at least a blocked urethane as component (B).

[0115] When the composition contains a blocked urethane as component (B), the content of the blocked urethane in the composition is, from the above-mentioned viewpoints, preferably 1 to 50 parts by mass, more preferably 2 to 40 parts by mass, and particularly preferably 5 to 30 parts by mass, per 100 parts by mass of component (A). When the content of the blocked urethane in the composition is (a) 1 part by mass or more per 100 parts by mass of component (A), the toughness, impact resistance, and adhesive properties (e.g., impact peel strength) of the cured product obtained by curing the resulting composition are favorably improved, and when the content is (b) 50 parts by mass or less, the resulting cured product has the advantage of being excellent in heat resistance and having a high elastic modulus.

[0116] [Component (b3): ​​Rubber-modified epoxy resin] The rubber-modified epoxy resin is a reaction product obtained by reacting rubber with an epoxy group-containing compound (e.g., an epoxy resin). The rubber-modified epoxy resin preferably has an average of 1.1 or more epoxy groups per molecule, and more preferably 2 or more epoxy groups.

[0117] Examples of rubber include rubber-based polymers such as acrylonitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), hydrogenated nitrile rubber (HNBR), ethylene-propylene rubber (EPDM), acrylic rubber (ACM), butyl rubber (IIR), butadiene rubber, and polyoxyalkylene (e.g., polypropylene oxide, polyethylene oxide, polytetramethylene oxide, etc.). The rubber-based polymer preferably has a terminal reactive group (a functional group capable of reacting with an epoxy group), such as an amino group, a hydroxy group, or a carboxyl group. The rubber-modified epoxy resin used in one embodiment of the present invention is a reaction product obtained by reacting these rubber-based polymers with an epoxy group-containing compound (e.g., an epoxy resin) in an appropriate blending ratio using a known method. Among these, from the viewpoints of the adhesiveness and impact peel adhesion resistance of the resulting curable resin composition, acrylonitrile-butadiene rubber-modified epoxy resins and polyoxyalkylene-modified epoxy resins are preferred, with acrylonitrile-butadiene rubber-modified epoxy resins being more preferred. The acrylonitrile-butadiene rubber modified epoxy resin can be obtained, for example, by reacting carboxyl-terminated NBR (CTBN) with bisphenol A type epoxy resin.

[0118] The content of the acrylonitrile monomer component (acrylonitrile unit) in the acrylonitrile-butadiene rubber (100% by mass) is preferably 5% by mass to 40% by mass, more preferably 10% by mass to 35% by mass, and even more preferably 15% by mass to 30% by mass, from the viewpoint of the adhesiveness and impact peel adhesion resistance of the resulting curable resin composition. The content of the acrylonitrile monomer component (acrylonitrile unit) in the acrylonitrile-butadiene rubber (100% by mass) is particularly preferably 20% by mass to 30% by mass, from the viewpoint of the workability of the resulting curable resin composition.

[0119] Furthermore, rubber-modified epoxy resins also include, for example, addition reaction products (hereinafter also referred to as "adducts") between amino-terminated polyoxyalkylenes and epoxy resins. The adducts can be easily produced by known methods, as described in, for example, U.S. Pat. Nos. 5,084,532 and 6,015,865. Examples of the epoxy resins used in producing the adducts include the specific examples of component (A) described above. As the epoxy resins used in producing the adducts, bisphenol A epoxy resins and bisphenol F epoxy resins are preferred, with bisphenol A epoxy resins being more preferred. Commercially available amino-terminated polyoxyalkylenes used in producing the adduct include, for example, Jeffamine (registered trademark) D-230, Jeffamine (registered trademark) D-400, Jeffamine (registered trademark) D-2000, Jeffamine (registered trademark) D-4000, and Jeffamine (registered trademark) T-5000, all of which are manufactured by Huntsman.

[0120] The reactive groups contained in the molecular terminals of the rubber are sometimes referred to as "epoxide reactive end groups." The average number of epoxide reactive end groups contained per rubber molecule is preferably 1.5 to 2.5, more preferably 1.8 to 2.2. The number average molecular weight of the rubber, as measured by GPC in terms of polystyrene, is preferably 1,000 to 10,000, more preferably 2,000 to 8,000, and particularly preferably 3,000 to 6,000.

[0121] There are no particular limitations on the method for producing rubber-modified epoxy resins. For example, rubber-modified epoxy resins can be produced by reacting rubber with an epoxy group-containing compound in a large amount of epoxy group-containing compound. Specifically, rubber-modified epoxy resins are preferably produced by reacting two or more equivalents of epoxy group-containing compound per equivalent of epoxy-reactive terminal groups in the rubber. It is more preferable to react a sufficient amount of epoxy group-containing compound with rubber so that the resulting product is a mixture of an adduct of rubber and epoxy group-containing compound and free epoxy group-containing compound. For example, rubber-modified epoxy resins can be produced by heating a mixture of rubber and epoxy group-containing compound to a temperature of 100°C to 250°C in the presence of a catalyst such as phenyldimethylurea and triphenylphosphine. While there are no particular limitations on the epoxy group-containing compound used in producing rubber-modified epoxy resins, bisphenol A epoxy resins and bisphenol F epoxy resins are preferred, with bisphenol A epoxy resins being more preferred.

[0122] In the case of rubber-modified epoxy resins, the epoxy resin can be modified by pre-reacting a bisphenol component with rubber. The amount of the bisphenol component used for modification is preferably 3 to 35 parts by mass, more preferably 5 to 25 parts by mass, per 100 parts by mass of the rubber component in the rubber-modified epoxy resin. The cured product obtained by curing a curable resin composition containing the modified rubber-modified epoxy resin has excellent adhesion durability after exposure to high temperatures and also excellent impact resistance at low temperatures.

[0123] The glass transition temperature (Tg) of the rubber-modified epoxy resin is not particularly limited, but is preferably −25° C. or lower, more preferably −35° C. or lower, even more preferably −40° C. or lower, and particularly preferably −50° C. or lower.

[0124] The number average molecular weight of the rubber-modified epoxy resin, as measured by GPC in terms of polystyrene, is preferably 1,500 to 40,000, more preferably 3,000 to 30,000, and particularly preferably 4,000 to 20,000. The molecular weight distribution (ratio of weight average molecular weight to number average molecular weight (weight average molecular weight / number average molecular weight)) of the rubber-modified epoxy resin is preferably 1 to 4, more preferably 1.2 to 3, and particularly preferably 1.5 to 2.5.

[0125] From the viewpoint of the balance of toughness, impact peel strength, heat resistance, and modulus of elasticity (rigidity) of the cured product, the present composition preferably contains at least a rubber-modified epoxy resin as component (B).

[0126] When the composition contains a rubber-modified epoxy resin as component (B), the content of the rubber-modified epoxy resin in the composition is preferably 1 to 50 parts by mass, more preferably 2 to 40 parts by mass, even more preferably 5 to 30 parts by mass, and particularly preferably 10 to 20 parts by mass, per 100 parts by mass of component (A). When the content of the rubber-modified epoxy resin in the composition is (a) 1 part by mass or more per 100 parts by mass of component (A), the obtained cured product has the advantage of excellent toughness and good Impact Peel strength, and when the content is (b) 50 parts by mass or less, the obtained cured product has the advantage of good heat resistance and / or elastic modulus (rigidity).

[0127] The rubber-modified epoxy resins may be used alone or in combination of two or more.

[0128] [Component (b3): ​​Urethane-modified epoxy resin] The urethane-modified epoxy resin is a reaction product obtained by reacting (i) a compound containing an epoxy group and a group reactive with an isocyanate group with (ii) a urethane prepolymer containing an isocyanate group. The urethane-modified epoxy resin preferably has an average of 1.1 or more epoxy groups per molecule, more preferably 2 or more. For example, a urethane-modified epoxy resin can be obtained by reacting a hydroxyl-containing epoxy compound with a urethane prepolymer.

[0129] The number average molecular weight of the urethane-modified epoxy resin, as measured by GPC in terms of polystyrene, is preferably 1,500 to 40,000, more preferably 3,000 to 30,000, and particularly preferably 4,000 to 20,000. The molecular weight distribution (ratio of weight average molecular weight to number average molecular weight (weight average molecular weight / number average molecular weight)) of the urethane-modified epoxy resin is preferably 1 to 4, more preferably 1.2 to 3, and particularly preferably 1.5 to 2.5.

[0130] From the viewpoint of the balance between toughness and heat resistance of the cured product, the present composition preferably contains at least a rubber-modified epoxy resin as component (B).

[0131] When the present composition contains a urethane-modified epoxy resin as component (B), the content of the urethane-modified epoxy resin in the composition is preferably 1 to 50 parts by mass, more preferably 2 to 40 parts by mass, even more preferably 5 to 30 parts by mass, and particularly preferably 10 to 20 parts by mass, per 100 parts by mass of component (A). When the content of the urethane-modified epoxy resin in the composition is (a) 1 part by mass or more per 100 parts by mass of component (A), the obtained cured product has the advantage of excellent toughness, and when (b) 50 parts by mass or less, the obtained cured product has the advantage of good heat resistance.

[0132] The urethane-modified epoxy resin may be used alone or in combination of two or more.

[0133] In this composition, the content of component (B) relative to 100 parts by mass of component (A) is preferably 1 to 200 parts by mass, more preferably 5 to 150 parts by mass, even more preferably 10 to 100 parts by mass, even more preferably 20 to 90 parts by mass, and particularly preferably 30 to 80 parts by mass. This configuration has the advantage that the resulting cured product has excellent toughness, impact resistance, and adhesion (e.g., impact peel strength). Note that the "content of component (B)" refers to the total content of components (b1), (b2), (b3), and (b4) contained in the composition.

[0134] 2-3. Component (C): Epoxy Curing Agent The present composition contains an epoxy curing agent as component (C). In this specification, the term "epoxy curing agent" refers to a compound (including an oligomer or polymer) containing an active hydrogen group that can react with the epoxy resin (A) to form a crosslink.

[0135] The present composition preferably contains, as component (C), an epoxy curing agent that is active at low temperatures. In this specification, the term "epoxy curing agent that is active at low temperatures" refers to a compound (including an oligomer or polymer) that contains an active hydrogen group and is capable of reacting with component (A) to form crosslinks even at low temperatures (for example, at least 0°C and less than 120°C).

[0136] Examples of epoxy curing agents active at low temperatures include amine-based curing agents. More specific examples of epoxy curing agents active at low temperatures include alicyclic amines (also known as "aliphatic cyclic polyamines"), aliphatic amines (also known as "chain aliphatic polyamines"), polyamidoamines, amine-terminated polyethers, amine-terminated butadiene nitrile rubbers, modified alicyclic amines, modified aliphatic amines, modified polyamidoamines, modified amine-terminated polyethers, and modified amine-terminated butadiene nitrile rubbers.

[0137] Examples of the alicyclic amine (alicyclic polyamine) include N-aminoethylpiperazine, piperazine, 1-(2-hydroxyethyl)piperazine, 2-methylpiperazine, 1-methylpiperazine, 2,5-dimethylpiperazine, menthenediamine, isophoronediamine, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, which is a type of spiroacetal diamine, norbornanediamine, bis(aminomethyl)tricyclodecane, and 1,3-bis(aminomethyl)cyclohexane.

[0138] Examples of the aliphatic amine (chain aliphatic polyamine) include chain aliphatic polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dipropylenetriamine, diethylaminopropylamine, hexamethylenediamine, 3-diethylaminopropylamine, 3-dimethylaminopropylamine, 2-diethylaminoethylamine, and 2-dimethylaminoethylamine, and aliphatic aromatic amines such as metaxylenediamine.

[0139] The polyamidoamine is a compound produced by condensing (i) (i-1) a dicarboxylic acid such as a dimer (dimer acid) of tall oil fatty acid, and / or (i-2) a monocarboxylic acid such as tall oil fatty acid, oleic acid, or neodecanoic acid, with (ii) a polyamine such as triethylenetetramine or tetraethylenepentamine. Commercially available polyamidoamines include Ancamide 910, Ancamide 350A, Versamid 140, and Versamid 115.

[0140] The amine-terminated polyether is an amine-terminated polyether having a polyether main chain and an average of preferably 1 to 4 (more preferably 1.5 to 3) amino and / or imino groups per molecule, such as poly(oxypropylene) monoamine, poly(oxypropylene) diamine, poly(oxypropylene) triamine, and poly(oxypropylene) tetraamine. Commercially available amine-terminated polyethers include Huntsman's Jeffamine D-230 (poly(oxypropylene)diamine), Jeffamine D-400 (poly(oxypropylene)diamine), Jeffamine D-2000 (poly(oxypropylene)diamine), Jeffamine D-4000 (poly(oxypropylene)diamine), and Jeffamine T-5000 (poly(oxypropylene)triamine).

[0141] Examples of modified amine curing agents include (i) polyamine epoxy resin adducts, which are reaction products of various polyamines such as the above-mentioned aliphatic amines and alicyclic amines with less than an equivalent amount of epoxy resin, and (ii) ketimines, which are dehydration reaction products of polyamines with ketones such as methyl ethyl ketone and isobutyl methyl ketone.

[0142] The component (C) of the present composition satisfies the following (1) and / or (2):

[0143] (1) The component (C) includes the following component (c1): component (c1) is an alicyclic amine; the content of the component (c1) is 25% by mass to 100% by mass in 100% by mass of the component (C); (2) The component (C) includes the following component (c2): component (c2) is a polyamidoamine; the active hydrogen equivalent of the component (C) is 50 g / eq to 90 g / eq, and the content of the component (c2) is 25% by mass to 100% by mass in 100% by mass of the component (C).

[0144] Hereinafter, a curable resin composition that satisfies at least the above-mentioned (1) will be described. In this specification, the alicyclic amine is also referred to as component (c1). In this specification, a curable resin composition that satisfies at least the above-mentioned (1) may be referred to as "composition (1)". Composition (1) contains, as component (C), an alicyclic amine that is component (c1). When this composition contains, as component (C), an alicyclic amine that is component (c1), there is an advantage that, when the composition is cured at a low temperature, a cured product that has an excellent balance between heat resistance and toughness can be obtained.

[0145] The alicyclic amine component (c1) may include (i) one or more selected from the group consisting of isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), N-aminoethylpiperazine, piperazine, 1-(2-hydroxyethyl)piperazine, 2-methylpiperazine, 1-methylpiperazine, 2,5-dimethylpiperazine, and menthenediamine. (ii) It is preferable that the solvent contains one or more selected from the group consisting of isophoronediamine, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), N-aminoethylpiperazine, 1-(2-hydroxyethyl)piperazine, and 1,3-bis(aminomethyl)cyclohexane, and it is more .... (iii) more preferably contains one or more selected from the group consisting of isophoronediamine, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), N-aminoethylpiperazine, and 1,3-bis(aminomethyl)cyclohexane, and more preferably consists of only one or more selected from this group; (iv) more preferably contains one or more selected from the group consisting of isophoronediamine, 4,4'-methylenebis(cyclohexylamine), and 4,4'-methylenebis(2-methylcyclohexylamine), and more preferably consists of only one or more selected from this group; and (v) even more preferably contains one or more selected from the group consisting of 4,4'-methylenebis(cyclohexylamine) and 4,4'-methylenebis(2-methylcyclohexylamine), and particularly preferably consists of only one or more selected from this group. This construction has the advantage that the resulting cured product has an excellent balance between toughness and heat resistance.

[0146] In composition (1), the content of component (c1) is 25% by mass to 100% by mass, preferably 30% by mass to 100% by mass, more preferably 40% by mass to 100% by mass, more preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, even more preferably 80% by mass to 100% by mass, and particularly preferably 90% by mass to 100% by mass. This configuration has the advantage that the resulting cured product has an excellent balance between toughness and heat resistance. The content of component (c1) may be 100% by mass out of 100% by mass of component (C); in other words, component (C) may consist solely of component (c1).

[0147] In composition (1), the content of component (c1) in the total amount of the composition (100% by mass) is preferably 3.5% by mass to 30.0% by mass, more preferably 3.6% by mass to 27.0% by mass, more preferably 3.7% by mass to 24.0% by mass, more preferably 3.8% by mass to 22.0% by mass, more preferably 3.9% by mass to 20.0% by mass, even more preferably 4.0% by mass to 18.0% by mass, and particularly preferably 8.0% by mass to 15.0% by mass. This configuration has the advantage that the resulting cured product has excellent toughness.

[0148] A curable resin composition that satisfies at least the above-mentioned (2) will be described below. In this specification, polyamidoamine is also referred to as component (c2). In this specification, a curable resin composition that satisfies at least the above-mentioned (2) may be referred to as "composition (2)". Composition (2) contains polyamidoamine, which is component (c2), as component (C). When this composition contains polyamidoamine, which is component (c2), as component (C), it has the advantage that a cured product with excellent toughness can be obtained when the composition is cured at a low temperature.

[0149] Furthermore, in composition (2), the active hydrogen equivalent of component (C) is 50 g / eq to 90 g / eq. By having the active hydrogen equivalent of component (C) in this range, the composition has the advantage that when cured at low temperatures, a cured product having an excellent balance between heat resistance and toughness can be obtained.

[0150] When component (C) contains multiple epoxy curing agents (1, 2, 3, ..., i), the active hydrogen equivalent of each epoxy curing agent is X １ , X ２ , X ３ , ..., X ｉ The mass ratio of each epoxy curing agent in component (C) is W １ , W ２ , W ３ , ..., W ｉ Then, the active hydrogen equivalent (X) of the component (C) can be calculated by the following formula: 1 / X = W １ / X １ +W ２ / X ２ +W ３ / X ３ +...W ｉ / X ｉ .

[0151] In composition (2), the active hydrogen equivalent of component (C) is 50 g / eq to 90 g / eq, preferably 53 g / eq to 88 g / eq, more preferably 55 g / eq to 87 g / eq, more preferably 58 g / eq to 85 g / eq, more preferably 60 g / eq to 82 g / eq, more preferably 62 g / eq to 81 g / eq, more preferably 62 g / eq to 80 g / eq, even more preferably 62 g / eq to 78 g / eq, and particularly preferably 65 g / eq to 75 g / eq. This configuration has the advantage that the resulting cured product has an excellent balance between heat resistance and toughness.

[0152] Commercially available polyamidoamines that are the component (c2) include Sunmide DT-200, Sunmide X-2000, Sunmide 330, Sunmide 336, Ancamide 910, Ancamide 350A, Versamid 140, and Versamid 115. Among these, Sunmide DT-200, Sunmide X-2000, Sunmide 330, Sunmide 336, Ancamide 350A and Versamid 140 are preferred, Sunmide DT-200, Sunmide X-2000, Sunmide 330 and Sunmide 336 are more preferred, and Sunmide DT-200 is particularly preferred.

[0153] In composition (2), the content of component (c2) is 25% by mass to 100% by mass, preferably 30% by mass to 100% by mass, more preferably 40% by mass to 100% by mass, more preferably 50% by mass to 100% by mass, more preferably 60% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, even more preferably 80% by mass to 100% by mass, and particularly preferably 90% by mass to 100% by mass. This configuration has the advantage that the resulting cured product has an excellent balance between toughness and heat resistance. The content of component (c2) may be 100% by mass out of 100% by mass of component (C); in other words, component (C) may consist solely of component (c2).

[0154] In composition (2), the content of component (c2) in the total amount of the composition (100% by mass) is preferably 3.5% by mass to 30.0% by mass, more preferably 3.6% by mass to 27.0% by mass, more preferably 3.7% by mass to 24.0% by mass, more preferably 3.8% by mass to 22.0% by mass, more preferably 3.9% by mass to 20.0% by mass, even more preferably 4.0% by mass to 18.0% by mass, and particularly preferably 8.0% by mass to 15.0% by mass. This configuration has the advantage that the resulting cured product has excellent toughness.

[0155] A curable resin composition according to one embodiment of the present invention may be both composition (1) and composition (2); in other words, it may satisfy both (1) and (2). That is, in a curable resin composition according to one embodiment of the present invention, the component (C) may include the components (c1) and (c2), the active hydrogen equivalent of the component (C) may be 50 g / eq to 90 g / eq, and the content of the component (c1) may be 25% by mass to 75% by mass and the content of the component (c2) may be 25% by mass to 75% by mass, relative to 100% by mass of the component (C). The preferred embodiment of the composition (1) described above is also preferred in a curable resin composition that satisfies both (1) and (2). The preferred embodiment of the composition (2) described above is also preferred in a curable resin composition that satisfies both (1) and (2).

[0156] In composition (1) and / or composition (2), the component (C) preferably further contains the following component (c3).

[0157] Component (c3): Amine-terminated butadiene nitrile rubber.

[0158] In this specification, the amine-terminated butadiene nitrile rubber is also referred to as component (c3). When the present composition further contains, as component (C), an amine-terminated butadiene nitrile rubber as component (c3) in addition to the components (c1) and / or (c2), there is an advantage that when the composition is cured at low temperature, a cured product having an excellent balance between heat resistance and toughness can be obtained.

[0159] In composition (1) according to one embodiment of the present invention, component (C) may include components (c1) and (c3), and the content of component (c1) may be 25% by mass or more and less than 100% by mass relative to 100% by mass of component (C). In composition (2) according to one embodiment of the present invention, component (C) may include components (c2) and (c3), and the content of component (c2) may be 25% by mass or more and less than 100% by mass relative to 100% by mass of component (C).

[0160] The amine-terminated butadiene nitrile rubber (c3) preferably has an average of 1 to 4 (more preferably 1.5 to 3) amino and / or imino groups per molecule. The amine-terminated butadiene nitrile rubber (c3) is a polybutadiene / acrylonitrile copolymer having an acrylonitrile monomer content in the main chain of preferably 5 to 40% by mass, more preferably 10 to 35% by mass, and even more preferably 15 to 30% by mass. Commercially available amine-terminated butadiene nitrile rubbers include Hypro 1300X16 ATBN manufactured by Huntsman.

[0161] The content of component (c3) in 100% by mass of component (C) is preferably 1% by mass to 75% by mass, more preferably 5% by mass to 70% by mass, even more preferably 10% by mass to 70% by mass, still more preferably 15% by mass to 65% by mass, and particularly preferably 20% by mass to 60% by mass. This configuration has the advantage that the resulting cured product has an excellent balance between toughness and heat resistance.

[0162] The content of component (c3) in the total amount (100% by mass) of the composition is preferably 0.3% by mass to 30.0% by mass, more preferably 1.0% by mass to 27.0% by mass, even more preferably 2.0% by mass to 22.0% by mass, still more preferably 4.0% by mass to 18.0% by mass, and particularly preferably 8.0% by mass to 15.0% by mass. This configuration has the advantage that the resulting cured product has excellent toughness.

[0163] In a curable resin composition according to one embodiment of the present invention, the component (C) may comprise the components (c1), (c2), and (c3), the active hydrogen equivalent of the component (C) may be 50 g / eq to 90 g / eq, and the content of the component (c1) may be 25 mass% or more and less than 75 mass%, and the content of the component (c2) may be 25 mass% or more and less than 75 mass%, relative to 100 mass% of the component (C).

[0164] Epoxy curing agents active at low temperatures also include aromatic amine and mercaptan curing agents. The present composition may contain an aromatic amine and / or mercaptan curing agent as component (C).

[0165] The present composition may further contain, as component (C), an epoxy curing agent that is active at high temperatures (e.g., an acid anhydride curing agent; a boron trifluoride-amine complex; dicyandiamide; an organic acid hydrazide; etc.).

[0166] In the present composition, the amount of component (C) per 100 parts by mass of component (A) is preferably 5 to 100 parts by mass, more preferably 10 to 90 parts by mass, more preferably 15 to 80 parts by mass, even more preferably 18 to 70 parts by mass, and particularly preferably 20 to 60 parts by mass. This configuration has the advantage that the resulting cured product has an excellent balance between toughness and heat resistance.

[0167] <2-4. Component (D): Epoxy-based reactive diluent> The present composition further comprises an epoxy-based reactive diluent as component (D). In this specification, the term "epoxy-based reactive diluent" refers to a compound having at least one epoxy group per molecule and having a viscosity of 500 mPa·s or less at 25°C. By including component (D), i.e., an epoxy-based reactive diluent, the composition has the advantage that the cured product obtained by curing the composition at low temperatures has superior toughness.

[0168] Examples of the epoxy-based reactive diluent include polyalkylene glycol diglycidyl ether, glycol diglycidyl ether, diglycidyl ester of an aliphatic polybasic acid, glycidyl ether of a dihydric or higher polyhydric aliphatic alcohol, and monoepoxide.

[0169] More specific examples of the polyalkylene glycol diglycidyl ether include polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, and dipropylene glycol diglycidyl ether.

[0170] More specific examples of the glycol diglycidyl ether include neopentyl glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, ethylene glycol diglycidyl ether, and propylene glycol diglycidyl ether.

[0171] More specific examples of the diglycidyl ester of the aliphatic polybasic acid include dimer acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, and maleic acid diglycidyl ester.

[0172] More specific examples of the glycidyl ether of dihydric or higher polyhydric aliphatic alcohol include trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl ether, castor oil-modified polyglycidyl ether, propoxylated glycerin triglycidyl ether, and sorbitol polyglycidyl ether.

[0173] Examples of monoepoxides include aliphatic glycidyl ethers such as butyl glycidyl ether; aromatic glycidyl ethers such as phenyl glycidyl ether and cresyl glycidyl ether (o-cresyl glycidyl ether); ethers containing a glycidyl group and an alkyl group having 8 to 10 carbon atoms, such as 2-ethylhexyl glycidyl ether; ethers containing a glycidyl group and a phenyl group having 6 to 12 carbon atoms, which may be substituted with an alkyl group having 2 to 8 carbon atoms, such as p-tert-butylphenyl glycidyl ether; ethers containing a glycidyl group and an alkyl group having 12 to 14 carbon atoms, such as dodecyl glycidyl ether (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 versatic acid glycidyl ester, neodecanoic acid glycidyl ester, and lauric acid glycidyl ester; and p-t-butylbenzoic acid glycidyl ester.

[0174] The present inventors have independently and independently discovered a novel finding that, when a composition contains an epoxy-based reactive diluent having two epoxy groups per molecule as component (D), the composition can provide a cured product having an excellent balance between heat resistance and toughness when cured at low temperatures. It is preferred that component (D) in this composition contains an epoxy-based reactive diluent having two epoxy groups per molecule. Examples of epoxy-based reactive diluents having two epoxy groups per molecule include the aforementioned polyalkylene glycol diglycidyl ether, glycol diglycidyl ether, and diglycidyl ester of an aliphatic polybasic acid.

[0175] The component (D) in the present composition preferably contains, out of 100 mass% of the component (D), 70 mass% or more, more preferably 80 mass% or more, even more preferably 90 mass% or more, and particularly preferably 90 mass% to 100 mass% of an epoxy-based reactive diluent having two epoxy groups per molecule. The component (D) may contain, out of 100 mass% of the component (D), 100 mass% of the epoxy-based reactive diluent having two epoxy groups per molecule; in other words, the component (D) may be composed solely of an epoxy-based reactive diluent having two epoxy groups per molecule.

[0176] Furthermore, the present inventors have independently and independently discovered the novel finding that when composition (1) contains, as component (D), an epoxy-based reactive diluent having one epoxy group per molecule, composition (1) can provide a cured product having excellent oily surface adhesion when cured at low temperatures. The oily surface adhesion refers to adhesion to a metal substrate whose surface is coated with an oil such as a rust preventive oil or press oil. It is preferable that component (D) in this composition contains an epoxy-based reactive diluent having one epoxy group per molecule. Examples of epoxy-based reactive diluents having one epoxy group per molecule include glycidyl esters such as versatic acid glycidyl ester and neodecanoic acid glycidyl ester; alkyl glycidyl ethers such as dodecyl glycidyl ether, which are ethers containing an alkyl group having 12 to 14 carbon atoms and a glycidyl group (alkyl C12-C14 glycidyl ether); and aromatic glycidyl ethers such as o-cresyl glycidyl ether. From the viewpoint of excellent adhesion to oily surfaces, alkyl glycidyl ethers and glycidyl esters are preferred, and glycidyl esters are particularly preferred.

[0177] As the epoxy-based reactive diluent, commercially available products can also be used. Commercially available epoxy-based reactive diluents include YED216M (manufactured by Mitsubishi Chemical, 1,6-hexanediol diglycidyl ether), Cardura® E10P (manufactured by Hexion, neodecanoic acid glycidyl ester), ERISYS® GE-10 (manufactured by Huntsman, o-cresyl glycidyl ether), 4-tert-butylphenyl glycidyl ether (manufactured by Tokyo Chemical Industry Co., Ltd.), 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), and ERISYS® Examples of such diluents include GE-21 (1,4-butanediol diglycidyl ether, manufactured by Huntsman), ERISYS (registered trademark) GE-24 (polypropylene glycol diglycidyl ether, manufactured by Huntsman), and PG-207 (polypropylene glycol diglycidyl ether, manufactured by Nippon Steel Chemical & Material Co., Ltd.). Note that Cardura (registered trademark) E10P, ERISYS (registered trademark) GE-10, 4-tert-butylphenyl glycidyl ether, ERISYS (registered trademark) GE-6, and ERISYS (registered trademark) GE-8 are each epoxy-based reactive diluents having one epoxy group per molecule. Furthermore, each of YED216M, ERISYS (registered trademark) GE-20, ERISYS (registered trademark) GE-21, ERISYS (registered trademark) GE-24, and PG-207 is an epoxy-based reactive diluent having two epoxy groups in one molecule.

[0178] In the present composition, the content of component (D) relative to 100 parts by mass of component (A) is preferably 1.0 part to 100.0 parts by mass, more preferably 1.0 part to 90.0 parts by mass, more preferably 1.0 part to 80.0 parts by mass, more preferably 1.0 part to 70.0 parts by mass, more preferably 1.0 part to 60.0 parts by mass, more preferably 1.0 part to 50.0 parts by mass, more preferably 1.0 part to 40.0 parts by mass, more preferably 1.0 part to 30.0 parts by mass, more preferably 1.0 part to 20.0 parts by mass, more preferably 2.0 parts to 18.0 parts by mass, more preferably 4.0 parts to 16.0 parts by mass, even more preferably 6.0 parts to 14.0 parts by mass, and particularly preferably 8.0 parts to 12.0 parts by mass. In the present composition, when the content of component (D) per 100 parts by mass of component (A) is within the above-mentioned range, the present composition has the advantage that the cured product obtained by curing the composition at low temperature has excellent toughness.

[0179] <2-5. Other Components> The composition may contain other components as needed. Examples of other components include, but are not limited to, curing accelerators (e.g., tertiary amines such as 2,4,6-tris(dimethylaminomethyl)phenol), reinforcing agents, inorganic fillers (e.g., silicic acid and / or silicates), calcium oxide, radical-curing resins, photopolymerization initiators, blowing agents (e.g., azo-type chemical blowing agents and / or thermally expandable microballoons), colorants (e.g., pigments and / or dyes), extender pigments, ultraviolet absorbers, antioxidants, stabilizers (antigelling agents), plasticizers, leveling agents, defoamers, silane coupling agents (e.g., 3-glycidoxypropyltrimethoxysilane), antistatic agents, flame retardants, lubricants, viscosity reducers, shrinkage reducing agents, organic fillers, thermoplastic resins, desiccants, and dispersants. Examples of inorganic fillers include untreated fumed silica and fumed silica surface-treated with polydimethylsiloxane or the like. These other components may be used alone or in combination of two or more, depending on the desired effect.

[0180] The inorganic filler may be silicic acid and / or silicate, and specific examples thereof include dry silica, wet silica, aluminum silicate, magnesium silicate, calcium silicate, wollastonite, and talc.

[0181] The dry silica is also called fumed silica, and examples thereof include hydrophilic fumed silica with no surface treatment, and hydrophobic fumed silica produced by chemically treating the silanol group portions of hydrophilic fumed silica with silane or siloxane. From the viewpoint of dispersibility in component (A), hydrophobic fumed silica is preferred.

[0182] Other inorganic fillers include reinforcing fillers such as dolomite and carbon black; colloidal calcium carbonate, heavy calcium carbonate, magnesium carbonate, titanium oxide, ferric oxide, fine aluminum powder, zinc oxide, and activated zinc oxide. Calcium carbonate is particularly preferred from the viewpoint of adhesive strength. The content of calcium carbonate is preferably 5 to 300 parts by mass, more preferably 10 to 250 parts by mass, even more preferably 20 to 200 parts by mass, and particularly preferably 30 to 150 parts by mass, per 100 parts by mass of component (A).

[0183] The inorganic filler is preferably surface-treated with a surface treatment agent. The surface treatment improves the dispersibility of the inorganic filler in the composition, thereby improving various physical properties of the resulting cured product. In particular, surface-treated heavy calcium carbonate is preferred from the viewpoint of adhesive strength.

[0184] The amount of inorganic filler used is preferably 1 to 300 parts by mass, more preferably 2 to 250 parts by mass, even more preferably 5 to 200 parts by mass, and particularly preferably 7 to 150 parts by mass, per 100 parts by mass of component (A).

[0185] The inorganic fillers may be used alone or in combination of two or more kinds.

[0186] <2-6. Others> The present composition may be a one-component type, a two-component type, or a multi-component type having three or more components.

[0187] When the composition is a two-component or multi-component curable resin composition, the following embodiments are preferred: A two-component or multi-component curable resin composition for low-temperature curing, comprising a first component and a second component, wherein the first component comprises the following components (A) and (D): Component (A): an epoxy resin; Component (D): an epoxy-based reactive diluent; The second component comprises the following component (C): Component (C): an epoxy curing agent; The curable resin composition further comprises the following component (B): Component (B): one or more selected from the group consisting of the following components (b1), (b2), (b3), and (b4): Component (b1): polymer particles having a core-shell structure comprising a core layer and a shell layer; Component (b2): blocked urethane; Component (b3): ​​rubber-modified epoxy resin; Component (b4): urethane-modified epoxy resin; A two-component or multi-component curable resin composition for low-temperature curing, which satisfies the following (1) and / or (2): (1) The component (C) includes the following component (c1): component (c1) is an alicyclic amine; the content of the component (c1) is 25% by mass to 100% by mass in 100% by mass of the component (C); (2) The component (C) includes the following component (c2): component (c2) is a polyamidoamine; the active hydrogen equivalent of the component (C) is 50 g / eq to 90 g / eq, and the content of the component (c2) is 25% by mass to 100% by mass in 100% by mass of the component (C).

[0188] The above-mentioned two-component or multi-component curable resin composition for low-temperature curing also has the advantage that, when cured at low temperatures, it can provide a cured product that has an excellent balance between heat resistance and toughness.

[0189] For specific aspects (e.g., aspects of each component) of the above-described two-component or multi-component curable resin composition for low-temperature curing, the above descriptions (e.g., descriptions of each component) are cited as appropriate. Preferred aspects in the above descriptions (e.g., descriptions of each component) are also preferred aspects of the above-described two-component or multi-component curable resin composition for low-temperature curing.

[0190] <2-7. Manufacturing Method of Curable Resin Composition> The manufacturing method of the curable resin composition is not particularly limited. When the composition is a one-component curable resin composition, for example, the curable resin composition can be manufactured by mixing the above-mentioned components (A), (B), (C), and (D), and other components as necessary, using a known mixing device (e.g., a planetary mixer).

[0191] When using polymer particles of component (b1) as component (B), it is preferable that the polymer particles of component (b1) are dispersed in the form of primary particles in the composition.From the viewpoint of efficiently obtaining a composition in which the polymer particles of component (b1) are dispersed in the form of primary particles, it is preferable to prepare a polymer particle-containing composition in which the polymer particles of component (b1) are dispersed in the form of primary particles in component (A) or component (D) before mixing with component (C) and component (D).By mixing the prepared polymer particle-containing composition with component (C), and if necessary, component (A), component (D) and other components using a known mixing device, it is possible to produce a composition in which the polymer particles of component (b1) are dispersed in the form of primary particles.

[0192] Various methods can be used to obtain the polymer particle-containing composition. Examples of such methods include (i) a method in which polymer particles obtained in an aqueous latex state are contacted with component (A) or (D), and then unnecessary components such as water are removed; (ii) a method in which the polymer particles are extracted with an organic solvent, the extracted polymer particles are mixed with component (A) or (D), and then the organic solvent is removed. The method described in WO 2005 / 028546 is preferably used to obtain the polymer particle-containing composition. The polymer particle-containing composition is preferably prepared by, in order, (i) a first step of mixing an aqueous latex containing polymer particles (more specifically, a reaction mixture obtained after producing polymer particles by emulsion polymerization) with an organic solvent having a solubility in water at 20°C of 5% by mass or more and 40% by mass or less, and then mixing the resulting mixture with excess water to aggregate the polymer particles; (ii) a second step of separating and recovering the aggregated polymer particles from the liquid phase, and then mixing the resulting polymer particle aggregates with an organic solvent again to obtain an organic solvent dispersion of the polymer particles; and (iii) a third step of mixing the organic solvent dispersion with component (A) or component (D), and then distilling off the organic solvent from the resulting mixture.

[0193] It is preferable that the components (A) and (D) are liquid at 23° C., since this facilitates the third step. "Liquid at 23° C." means that the softening point is 23° C. or lower, and the component exhibits flowability at 23° C.

[0194] Powdered polymer particles can also be used to obtain the polymer particle-containing composition. For example, powdered polymer particles can be obtained by using polymer particles obtained in an aqueous latex state, coagulating the polymer particles by a method such as salting out, and then drying the resulting aggregates. The obtained powdered polymer particles can be redispersed in component (A) or component (D) using a disperser with high mechanical shear force, such as a triple paint roll, a roll mill, or a kneader. In this case, applying mechanical shear force at a high temperature enables efficient redispersion of component (B). The temperature when redispersing component (B) in component (A) or component (D) is preferably 50 to 200°C, more preferably 70 to 170°C, even more preferably 80 to 150°C, and particularly preferably 90 to 120°C.

[0195] When the present composition is a two-component or multi-component curable resin composition containing a first component and a second component, for example, the first component containing the component (B) can be produced by mixing the above-mentioned components (A), (B), and (D), as well as other components as needed, using a known mixing device (e.g., a planetary mixer, etc.). When the polymer particles of component (b1) are used as component (B), the first component containing the components (A), (B), and (D) corresponds to the above-mentioned polymer particle-containing composition. Furthermore, the second component can be produced by mixing the component (C), as well as the component (B) and other components as needed, using a known mixing device (e.g., a planetary mixer, etc.). The first and second components produced in this manner are preferably mixed and used immediately before use (e.g., immediately before the bonding operation of the adherend or immediately before the curable resin composition is cured).

[0196] When the present composition is a two-component or multi-component curable resin composition containing a first component and a second component, as another example, the first component not containing the component (B) can be produced by mixing the above-mentioned components (A) and (D), and other components as needed, using a known mixing device (e.g., a planetary mixer, etc.). Alternatively, the second component containing the component (B) can be produced by mixing the components (B), (C), and other components as needed, using a known mixing device (e.g., a planetary mixer, etc.). The first and second components produced in this manner are preferably mixed and used immediately before use (e.g., immediately before the bonding operation of the adherends or immediately before the curable resin composition is cured).

[0197] [3. Cured Product] One embodiment of the present invention also provides a cured product obtained by curing the curable resin composition according to one embodiment of the present invention described in the above section [2. Curable Resin Composition]. In other words, a cured product obtained by curing the curable resin composition according to one embodiment of the present invention can also be said to be a cured product according to one embodiment of the present invention. When the composition is used as an adhesive (for example, a vehicle adhesive (structural adhesive) for vehicles and aircraft, an adhesive for secondary batteries such as EV battery cells, a structural adhesive for wind power generation, etc.), the cured product obtained by curing the composition (adhesive) can also be said to be an adhesive layer.

[0198] The cured product according to one embodiment of the present invention has the advantage of having an excellent balance between heat resistance and toughness.

[0199] When the composition is a one-component type, a cured product can be obtained by curing the curable resin composition at a curing temperature described below. When the component (B) contains polymer particles (b1) as component (B1), and the polymer particles are dispersed in the curable resin composition in the form of primary particles, the polymer particles are also considered to be dispersed in the obtained cured product in the form of primary particles.

[0200] When the present composition is a two-component or multi-component composition containing a first component and a second component, the first component and the second component are mixed uniformly using a static mixer or the like, and the resulting mixture (composition) is cured at a curing temperature described below to obtain a cured product. When component (B) contains polymer particles (b1) and the polymer particles are dispersed in the first component and / or the second component in the form of primary particles, the polymer particles are considered to be dispersed in the resulting cured product in the form of primary particles as well.

[0201] Another embodiment of the cured product of the present invention is a cured product obtained by curing a curable resin composition containing the following components (A), (B), (C), and (D): component (A): an epoxy resin; component (B): one or more selected from the group consisting of the following components (b1), (b2), (b3), and (b4); component (b1): polymer particles having a core-shell structure containing a core layer and a shell layer; component (b2): blocked urethane; component (b3): ​​rubber-modified epoxy resin; component (b4): urethane-modified epoxy resin; component (C): epoxy curing agent; component (D): epoxy-based reactive diluent; and the degree of cure measured by differential scanning calorimetry (DSC) is 50% to 95%, and the curable resin composition satisfies the following (1) and / or (2): (1) the component (C) contains the following component (c1): component (c1): alicyclic amine; (2) The component (C) contains the following component (c2): component (c2): polyamidoamine; the active hydrogen equivalent of the component (C) is 50 g / eq to 90 g / eq.

[0202] The cured product according to another embodiment of the present invention also has the advantage of having an excellent balance between heat resistance and toughness.

[0203] The degree of cure of a cured product according to another embodiment of the present invention is 50% to 95% as measured by differential scanning calorimetry (DSC). Generally, the degree of cure of a cured product obtained by curing a curable resin composition at a high temperature as measured by DSC is greater than 95%, and may be 96% to 100%. On the other hand, the degree of cure of a cured product obtained by curing a curable resin composition at a low temperature as measured by DSC may be 95% or less. In other words, when the degree of cure of a cured product according to another embodiment of the present invention is 95% or less as measured by DSC, it is intended to mean that the cured product according to another embodiment of the present invention has been obtained by low-temperature curing.

[0204] The higher the degree of cure of the cured product measured by DSC, the more advantageously the cured product has excellent heat resistance. Therefore, the degree of cure of the cured product according to another embodiment of the present invention measured by DSC is preferably 60% to 95%, more preferably 70% to 95%, even more preferably 75% to 95%, and particularly preferably 80% to 95%. The method for measuring the degree of cure of the cured product by DSC will be described in detail in the Examples below.

[0205] The glass transition temperature (Tg) of the cured product according to one embodiment of the present invention and the cured product according to another embodiment of the present invention is not particularly limited. The higher the glass transition temperature (Tg), the more excellent the heat resistance of the cured product. The glass transition temperature (Tg) is preferably 80°C or higher, more preferably 82°C or higher, even more preferably 85°C or higher, and particularly preferably 90°C or higher. The upper limit of the glass transition temperature (Tg) is not particularly limited, but is, for example, 150°C or lower. A method for measuring the glass transition temperature (Tg) of a cured product will be described in detail in the Examples below.

[0206] The storage modulus at 70°C of the cured product according to one embodiment of the present invention and the cured product according to another embodiment of the present invention is not particularly limited. It is intended that the higher the storage modulus value, the more excellent the heat resistance of the cured product. The storage modulus is preferably 0.14 GPa or more, more preferably 0.17 GPa or more, even more preferably 0.20 GPa or more, and particularly preferably 0.50 GPa or more. The upper limit of the storage modulus is not particularly limited, but is, for example, 5.00 GPa or less. A method for measuring the storage modulus at 70°C of the cured product will be described in detail in the Examples below.

[0207] The fracture toughness (K1c) of the cured product according to one embodiment of the present invention and the cured product according to another embodiment of the present invention is not particularly limited. The larger the fracture toughness (K1c) value, the more excellent the toughness of the cured product. The fracture toughness (K1c) is 1.10 MPa m １／２ It is preferable that the viscosity is 1.40 MPa m or more. １／２ More preferably, it is 1.70 MPa m or more. １／２ More preferably, it is 2.00 MPa m or more. １／２ The upper limit of the storage modulus is not particularly limited, but is, for example, 5.00 MPa m １／２ The method for measuring the fracture toughness (K1c) of the cured product will be described in detail in the Examples below.

[0208] The fracture toughness (G1c) of the cured product according to one embodiment of the present invention and the cured product according to another embodiment of the present invention is not particularly limited. The larger the fracture toughness (G1c) value, the more excellent the toughness of the cured product. The fracture toughness (G1c) is 0.30 kJ / m ２ It is preferable that the concentration is 0.50 kJ / m or more. ２ More preferably, it is 0.80 kJ / m or more. ２ More preferably, it is 1.50 kJ / m or more. ２ The upper limit of the storage modulus is not particularly limited, but is, for example, 10.00 kJ / m ２The method for measuring the fracture toughness (G1c) of the cured product will be described in detail in the Examples below.

[0209] The shear bond strength of the cured product according to one embodiment of the present invention and the cured product according to another embodiment of the present invention is not particularly limited. The higher the shear bond strength value, the more excellent the toughness of the cured product. The shear bond strength is preferably 18 MPa or more, more preferably 19 MPa or more, even more preferably 20 MPa or more, and particularly preferably 21 MPa or more. The upper limit of the shear bond strength is not particularly limited, but is, for example, 40 MPa or less. The method for measuring the shear bond strength of the cured product will be described in detail in the Examples below.

[0210] The T-peel adhesive strength of the cured product according to one embodiment of the present invention and the cured product according to another embodiment of the present invention is not particularly limited. It is intended that the higher the T-peel adhesive strength value, the more excellent the toughness of the cured product. The T-peel adhesive strength is preferably 100 N / 25 mm or more, more preferably 105 N / 25 mm or more, even more preferably 110 N / 25 mm or more, and particularly preferably 115 N / 25 mm or more. The upper limit of the T-peel adhesive strength is not particularly limited, but is, for example, 400 N / 25 mm or less. The method for measuring the T-peel adhesive strength of the cured product will be described in detail in the Examples below.

[0211] The impact peel strength of the cured product according to one embodiment of the present invention and the cured product according to another embodiment of the present invention is not particularly limited. The higher the impact peel strength value, the more excellent the toughness of the cured product. The impact peel strength is preferably 17 kN / m or more, more preferably 18 kN / m or more, even more preferably 19 kN / m or more, and particularly preferably 20 kN / m or more. The upper limit of the storage modulus is not particularly limited, but is, for example, 100 kN / m or less. The method for measuring the impact peel strength of the cured product will be described in detail in the Examples below.

[0212] (Application Method) The present composition can be applied to a substrate by any method. The present composition may be applied in the form of a low-temperature composition at about room temperature without heating, or may be applied in the form of a high-temperature composition after heating.

[0213] The method for applying the composition is not particularly limited, and for example, the composition can be applied by extrusion onto a substrate in the form of a bead, monofilament, or swirl using a coating robot. The viscosity of the composition at the application temperature is not particularly limited. For example, the viscosity of the composition at the application temperature is preferably about 150 Pa·s to 600 Pa·s in the extrusion bead method, about 100 Pa·s in the swirl coating method, and about 20 Pa·s to 400 Pa·s in the high-volume coating method using a high-speed flow device.

[0214] The present invention will be described with reference to a case where the composition is a two-component or multi-component curable resin composition containing a first component and a second component. In this case, the first and second components of the curable resin composition can be applied (applied) after being discharged from a constant-volume dispenser and uniformly mixed in a static mixer connected to the tip of the device. Alternatively, the first and second components of the curable resin composition can be filled into the cartridges of a double-cartridge caulking gun connected to the tip of the static mixer, and then manually extruded to apply the composition.

[0215] The method for producing the present cured product, in other words, the method for curing the present composition, is not particularly limited. For example, the present composition can be cured by heating the composition to a certain temperature (curing temperature) and maintaining the composition at the curing temperature for a certain time (curing time), thereby obtaining a cured product.

[0216] In one embodiment of the present invention, the curable resin composition is a composition for use in applications where curing is performed at low temperatures, i.e., a curable resin composition for low-temperature curing. As used herein, "low-temperature curing" or "curing at low temperatures" refers to curing the curable resin composition at a temperature of 0°C or higher but lower than 120°C. In other words, when a curable resin composition is cured at a high temperature of 120°C or higher, this is not considered "low-temperature curing" but "high-temperature curing" in this specification.

[0217] A method for producing a cured product according to one embodiment of the present invention includes a step of curing the curable resin composition according to one embodiment of the present invention described in the above section [2. Curable Resin Composition] at a low temperature (for example, at a temperature of 0°C or higher and lower than 120°C). One embodiment of the present invention provides use of a curable resin composition, including a step of curing the curable resin composition according to one embodiment of the present invention described in the above section [2. Curable Resin Composition] at a low temperature (for example, at a temperature of 0°C or higher and lower than 120°C). Because the curable resin composition according to one embodiment of the present invention has the above-described configuration, even when cured at a low temperature (for example, at a temperature of 0°C or higher and lower than 120°C), a cured product having an excellent balance between heat resistance and toughness can be obtained.

[0218] The curing temperature of the curable resin composition is preferably 10°C to 119°C, more preferably 10°C to 115°C, even more preferably 20°C to 100°C, and particularly preferably 20°C to 90°C.

[0219] The curing time is not particularly limited as long as the composition can be cured (for example, as long as the degree of cure of the obtained cured product measured by DSC is 50% or more). The curing time is preferably 0.1 to 100 hours, more preferably 0.2 to 90 hours, even more preferably 0.3 to 80 hours, and particularly preferably 0.5 to 70 hours.

[0220] [4. Applications] The curable resin composition is preferably used in applications such as adhesives (for example, vehicle adhesives (structural adhesives) for vehicles and aircraft, adhesives for secondary batteries such as EV battery cells, and structural adhesives for wind power generation), materials for impregnating glass fibers and / or carbon fibers to obtain fiber-reinforced composite materials (hereinafter, also referred to as "impregnation materials"), materials for printed wiring boards, solder resists, interlayer insulating films, build-up materials, adhesives for FPCs, electrically insulating materials such as sealants for electronic components such as semiconductors and LEDs, die bond materials, underfills, mounting materials for semiconductors (for example, ACF, ACP, NCF, NCP), sealants for display devices (for example, liquid crystal panels and OLED displays), sealants for lighting devices (for example, OLED lighting), concrete repair materials, and coating materials (for example, concrete coating materials).

[0221] In other words, one embodiment of the present invention provides use of the curable resin composition according to one embodiment of the present invention described in the above section [2. Curable resin composition] as one or more materials selected from the group consisting of adhesives, impregnation materials, materials for printed wiring boards, solder resists, interlayer insulating films, build-up materials, adhesives for FPCs, electrical insulating materials, die-bonding materials, underfills, semiconductor mounting materials, sealants for display devices, sealants for lighting devices, concrete repair materials, and coating materials.

[0222] When the curable resin composition is used as an impregnation material (a material to be impregnated into fibers to obtain a composite material), it can be used in a wide range of molding methods without any particular limitation. Specifically, it can be molded by known molding methods such as hand layup, spray-up, pultrusion, filament winding, matched die, prepreg, centrifugal molding, liquid molding, hot press, casting, injection molding, continuous lamination, resin transfer molding (RTM), vacuum bag molding, and cold press.

[0223] The curable resin composition is suitable as a raw material for composite materials with glass fiber or carbon fiber, BMC (bulk molding compound) or SMC (sheet molding compound). There are no particular limitations on the application site, but specifically, it is suitable for artificial marble applications such as kitchen counters, washbasins, bathtubs, and wall materials, resin concrete, tanks, pressure vessels, industrial pipes, factory piping, joints, pipes, corrugated sheets, helmets, poles, wind power generation blades, piping for oil field pumping systems such as sucker rod pumps, electrical parts, automobile parts, railway vehicle parts, ship parts, aircraft parts, industrial machinery parts, construction materials, furniture, musical instruments, and other structural members, and sheet materials such as decorative panels and decorative sheets.

[0224] An embodiment of the present invention may have the following configuration.

[0225] [X1] A curable resin composition for low-temperature curing, comprising the following components (A), (B), (C), and (D): component (A): an epoxy resin; component (B): one or more selected from the group consisting of the following components (b1), (b2), (b3), and (b4); component (b1): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (b2): blocked urethane; component (b3): ​​rubber-modified epoxy resin; component (b4): urethane-modified epoxy resin; component (C): epoxy curing agent; component (D): epoxy-based reactive diluent; and satisfying the following (1) and / or (2): (1) the component (C) comprises the following component (c1): component (c1): alicyclic amine; the content of the component (c1) is 25% by mass to 100% by mass in 100% by mass of the component (C); (2) The component (C) contains the following component (c2): component (c2): polyamidoamine; the active hydrogen equivalent of the component (C) is 50 g / eq to 90 g / eq, and the content of the component (c2) is 25 mass% to 100 mass% relative to 100 mass% of the component (C).

[0226] [X2] A two-component or multi-component curable resin composition for low-temperature curing, comprising a first component and a second component, wherein the first component comprises the following components (A) and (D): component (A): an epoxy resin; component (D): an epoxy-based reactive diluent; the second component comprises the following component (C): component (C): an epoxy curing agent; the curable resin composition further comprises the following component (B): component (B): one or more selected from the group consisting of the following components (b1), (b2), (b3), and (b4): component (b1): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (b2): blocked urethane; component (b3): ​​rubber-modified epoxy resin; component (b4): urethane-modified epoxy resin; A two-component or multi-component curable resin composition for low-temperature curing, satisfying the following (1) and / or (2): (1) the component (C) comprises the following component (c1), (c1) component: alicyclic amine; the content of the (c1) component is 25% by mass to 100% by mass of 100% by mass of the (C) component; (2) the (C) component includes the following (c2) component: (c2) component: polyamidoamine; the active hydrogen equivalent of the (C) component is 50 g / eq to 90 g / eq, and the content of the (c2) component is 25% by mass to 100% by mass of 100% by mass of the (C) component.

[0227] [X3] The curable resin composition according to [X1] or [X2], wherein the component (C) further contains the following component (c3): Component (c3): amine-terminated butadiene nitrile rubber.

[0228] [X4] The curable resin composition according to any one of [X1] to [X3], wherein the component (A) contains the following component (a1) and / or component (a2): component (a1): bisphenol A epoxy resin; component (a2): bisphenol F epoxy resin.

[0229] [X5] The curable resin composition according to [X4], wherein the total content of the (a1) component and the (a2) component is 5% by mass to 100% by mass, relative to 100% by mass of the (A) component.

[0230] [X6] The curable resin composition according to any one of [X1] to [X5], wherein the core layer of the component (b1) contains one or more rubbers selected from the group consisting of diene rubbers, (meth)acrylate rubbers, and organosiloxane rubbers.

[0231] [X7] The curable resin composition according to any one of [X1] to [X6], wherein the core layer of the component (b1) is butadiene rubber and / or butadiene-styrene rubber.

[0232] [X8] The curable resin composition according to any one of [X1] to [X7], wherein the shell layer of the component (b1) contains one or more structural units selected from the group consisting of aromatic vinyl units, vinylcyan units, and (meth)acrylate units.

[0233] [X9] The content of the (B) component is 1 part by mass to 200 parts by mass per 100 parts by mass of the (A) component. The curable resin composition according to any one of [X1] to [X8].

[0234] [X10] The curable resin composition according to any one of [X1] to [X9], wherein the component (c1) includes one or more selected from the group consisting of isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), N-aminoethylpiperazine, piperazine, and menthenediamine.

[0235] [X11] The curable resin composition according to any one of [X1] to [X10], wherein the component (c1) includes one or more selected from the group consisting of isophoronediamine, 4,4'-methylenebis(cyclohexylamine), and 4,4'-methylenebis(2-methylcyclohexylamine).

[0236] [X12] The curable resin composition according to any one of [X1] to [X11], wherein the content of the component (C) is 5 parts by mass to 100 parts by mass per 100 parts by mass of the component (A).

[0237] [X13] The content of the (c1) component is 3.5% by mass to 30.0% by mass, relative to 100% by mass of the total amount of the curable resin composition. The curable resin composition according to any one of [X1] to [X12].

[0238] [X14] The curable resin composition according to any one of [X1] to [X13], wherein the component (D) includes an epoxy-based reactive diluent having two epoxy groups in one molecule.

[0239] [X15] The content of the (D) component is 1.0 parts by mass to 100.0 parts by mass per 100 parts by mass of the (A) component. The curable resin composition according to any one of [X1] to [X14].

[0240] [X16] The curable resin composition according to any one of [X1] to [X15], further containing 5 to 300 parts by mass of calcium carbonate per 100 parts by mass of the component (A).

[0241] [X17] Use of the curable resin composition according to any one of [X1] to [X16] as one or more selected from the group consisting of adhesives, impregnation materials, and coating materials.

[0242] [X18] Use of a curable resin composition, comprising a step of curing the curable resin composition according to any one of [X1] to [X16] at low temperature.

[0243] [X19] A method for producing a cured product, comprising a step of curing the curable resin composition according to any one of [X1] to [X16] at low temperature.

[0244] [X20] An adhesive comprising the curable resin composition according to any one of [X1] to [X16].

[0245] [X21] An impregnated material comprising the curable resin composition according to any one of [X1] to [X16].

[0246] [X22] A coating material comprising the curable resin composition according to any one of [X1] to [X16].

[0247] [X23] A cured product obtained by curing the curable resin composition according to any one of [X1] to [X16].

[0248] [X24] A cured product obtained by curing a curable resin composition containing the following components (A), (B), (C), and (D), wherein the component (A): an epoxy resin; the component (B): one or more selected from the group consisting of the following components (b1), (b2), (b3), and (b4); the component (b1): polymer particles having a core-shell structure containing a core layer and a shell layer; the component (b2): blocked urethane; the component (b3): ​​rubber-modified epoxy resin; the component (b4): urethane-modified epoxy resin; the component (C): epoxy curing agent; the component (D): epoxy-based reactive diluent; The cured product has a degree of cure of 50% to 95% by differential scanning calorimetry (DSC), and the curable resin composition satisfies the following (1) and / or (2): (1) the component (C) contains the following component (c1), the component (c1): alicyclic amine; (2) The component (C) contains the following component (c2): component (c2): polyamidoamine; the active hydrogen equivalent of the component (C) is 50 g / eq to 90 g / eq.

[0249] [X25] A cured product obtained by curing a curable resin composition containing the following components (A), (B), (C), and (D): component (A): epoxy resin; component (B): one or more selected from the group consisting of the following components (b1), (b2), (b3), and (b4); component (b1): polymer particles having a core-shell structure containing a core layer and a shell layer; component (b2): blocked urethane; component (b3): ​​rubber-modified epoxy resin; component (b4): urethane-modified epoxy resin; component (C): epoxy curing agent; component (D): epoxy-based reactive diluent; A cured product obtained by curing a curable resin composition satisfying the following (1) and / or (2): (1) the component (C) contains the following component (c1), component (c1): alicyclic amine; and the degree of cure measured by differential scanning calorimetry (DSC) is 50% to 95%; (2) The component (C) includes the following component (c2): component (c2): polyamidoamine; the active hydrogen equivalent of the component (C) is 50 g / eq to 90 g / eq; and the degree of cure measured by differential scanning calorimetry (DSC) is 50% to 95%.

[0250] [X26] The cured product according to [X24] or [X25], wherein the content of the (c1) component and / or the (c2) component is 25% by mass to 100% by mass in 100% by mass of the (C) component.

[0251] An embodiment of the present invention may have the following configuration.

[0252] [Y1] A curable resin composition for low temperature curing, comprising the following components (A), (B), (C), and (D): component (A): an epoxy resin; component (B): one or more selected from the group consisting of the following components (b1), (b2), (b3), and (b4); component (b1): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (b2): blocked urethane; component (b3): ​​rubber-modified epoxy resin; component (b4): urethane-modified epoxy resin; component (C): epoxy curing agent; component (D): epoxy-based reactive diluent; component (C) comprises the following component (c1): component (c1): alicyclic amine; and the content of component (c1) is 10% by mass to 100% by mass relative to 100% by mass of component (C).

[0253] [Y2] A two-component or multi-component curable resin composition for low-temperature curing, comprising a first component and a second component, wherein the first component comprises the following components (A) and (D): component (A): an epoxy resin; component (D): an epoxy-based reactive diluent; the second component comprises the following component (C): component (C): an epoxy curing agent; the curable resin composition further comprises the following component (B): component (B): one or more selected from the group consisting of the following components (b1), (b2), (b3), and (b4): component (b1): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (b2): blocked urethane; component (b3): ​​rubber-modified epoxy resin; component (b4): urethane-modified epoxy resin; the component (C) comprises the following component (c1): component (c1): alicyclic amine; A two-component or multi-component curable resin composition for low-temperature curing, wherein the content of the component (c1) is 10 mass % to 100 mass % relative to 100 mass % of the component (C).

[0254] [Y3] The curable resin composition according to [Y1] or [Y2], wherein the component (A) contains the following component (a1) and / or component (a2): component (a1): bisphenol A epoxy resin; component (a2): bisphenol F epoxy resin.

[0255] [Y4] The curable resin composition according to [Y3], wherein the total content of the (a1) component and the (a2) component is 5% by mass to 100% by mass, relative to 100% by mass of the (A) component.

[0256] [Y5] The curable resin composition according to any one of [Y1] to [Y4], wherein the core layer of the component (b1) contains one or more rubbers selected from the group consisting of diene rubbers, (meth)acrylate rubbers, and organosiloxane rubbers.

[0257] [Y6] The curable resin composition according to any one of [Y1] to [Y5], wherein the core layer of the component (b1) is butadiene rubber and / or butadiene-styrene rubber.

[0258] [Y7] The curable resin composition according to any one of [Y1] to [Y6], wherein the shell layer of the component (b1) contains one or more structural units selected from the group consisting of aromatic vinyl units, vinyl cyanide units, and (meth)acrylate units.

[0259] [Y8] The curable resin composition according to any one of [Y1] to [Y7], wherein the content of the component (B) is 1 part by mass to 200 parts by mass per 100 parts by mass of the component (A).

[0260] [Y9] The curable resin composition according to any one of [Y1] to [Y8], wherein the component (c1) includes one or more selected from the group consisting of isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), N-aminoethylpiperazine, piperazine, and menthenediamine.

[0261] [Y10] The curable resin composition according to any one of [Y1] to [Y9], wherein the content of the component (C) is 5 parts by mass to 100 parts by mass per 100 parts by mass of the component (A).

[0262] [Y11] The curable resin composition according to any one of [Y1] to [Y10], wherein the component (D) includes an epoxy-based reactive diluent having two epoxy groups in one molecule.

[0263] [Y12] The curable resin composition according to any one of [Y1] to [Y11], wherein the content of the component (D) is 1.0 parts by mass to 100.0 parts by mass per 100 parts by mass of the component (A).

[0264] [Y13] Use of the curable resin composition according to any one of [Y1] to [Y12] as one or more materials selected from the group consisting of adhesives, impregnation materials, and coating materials.

[0265] [Y14] Use of a curable resin composition, comprising a step of curing the curable resin composition according to any one of [Y1] to [Y12] at low temperature.

[0266] [Y15] A method for producing a cured product, comprising a step of curing the curable resin composition according to any one of [Y1] to [Y12] at low temperature.

[0267] [Y16] A cured product obtained by curing a curable resin composition containing the following components (A), (B), (C), and (D): component (A): epoxy resin; component (B): one or more selected from the group consisting of the following components (b1), (b2), (b3), and (b4); component (b1): polymer particles having a core-shell structure containing a core layer and a shell layer; component (b2): blocked urethane; component (b3): ​​rubber-modified epoxy resin; component (b4): urethane-modified epoxy resin; component (C): epoxy curing agent; component (D): epoxy-based reactive diluent; component (C) contains the following component (c1): component (c1): alicyclic amine; and the cured product has a degree of cure of 50% to 95% as measured by differential scanning calorimetry (DSC).

[0268] [Y17] The cured product according to [Y16], wherein the content of the (c1) component is 10% by mass to 100% by mass relative to 100% by mass of the (C) component.

[0269] Hereinafter, one embodiment of the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited thereto. One embodiment of the present invention can be carried out by appropriately modifying the following examples within the scope that can comply with the above-mentioned and below-mentioned aims. All embodiments carried out by appropriately modifying the following examples are included within the technical scope of the present invention. In the following examples, comparative examples, and tables, "parts" and "%" mean parts by mass and % by mass, respectively.

[0270] [Materials] First, the materials used in the examples and comparative examples are listed below.

[0271] <Component (A)> A-(1): Difunctional bisphenol A epoxy resin <difunctional bisphenol A epoxy resin that is liquid at room temperature> (manufactured by Mitsubishi Chemical Corporation, "jER828", epoxy equivalent: 189 g / eq) <Component (B)> [Component (b1) (polymer particles)] Component (b1) (polymer particles) prepared by the following method was used. Note that, as described below, dispersions (M-(1) to M-(3)) in which the prepared component (B) (component (b1) (polymer particles)) was dispersed in component (A) (A-(1)) were prepared and used in the examples.

[0272] 1. Formation of Core Layer Production Example 1-1: Preparation of Polybutadiene Rubber Latex (R-1) Into a 100 L pressure-resistant polymerization reactor, 200 parts by mass of deionized water, 0.03 parts by mass of tripotassium phosphate, 0.25 parts by mass of potassium dihydrogen phosphate, 0.002 parts by mass of disodium ethylenediaminetetraacetate (EDTA), 0.001 parts by mass of ferrous sulfate heptahydrate (FE), and 1.5 parts by mass of sodium dodecylbenzenesulfonate (SDS) as an emulsifier were charged. Next, the gas inside the pressure-resistant polymerization reactor was replaced with nitrogen while stirring the charged raw materials, thereby thoroughly removing oxygen from inside 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. Next, 0.015 parts by mass of paramenthane hydroperoxide (PHP) was charged into the pressure-resistant polymerization reactor, followed by 0.04 parts by mass of sodium formaldehyde sulfoxylate (SFS) to initiate polymerization. Ten hours after the start of polymerization, the polymerization was terminated by devolatilization under reduced pressure to remove remaining monomers that had not been used in the polymerization. During the polymerization, PHP, EDTA, and FE were each added to the pressure-resistant polymerization reactor in desired amounts and at desired times. This polymerization procedure yielded a latex (R-1) containing a core layer (polybutadiene rubber particles) primarily composed of polybutadiene rubber. The volume average particle diameter of the polybutadiene rubber particles contained in the resulting latex was 0.10 μm.

[0273] Production Example 1-2: Preparation of Polybutadiene Rubber Latex (R-2) 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 parts by mass of tripotassium phosphate, 0.002 parts by mass of EDTA, and 0.001 parts by mass of FE were charged into a 100 L pressure-resistant polymerization reactor. Next, the gas inside the pressure-resistant polymerization reactor was replaced with nitrogen while stirring the charged raw materials, thereby thoroughly removing oxygen from inside the pressure-resistant polymerization reactor. Thereafter, 93 parts by mass of BD were charged into the pressure-resistant polymerization reactor, and the temperature inside the pressure-resistant polymerization reactor was raised to 45°C. Next, 0.02 parts by mass of PHP was charged into the pressure-resistant polymerization reactor, followed by 0.10 parts by mass of SFS, to initiate polymerization. Thirty hours after the start of polymerization, volatilization was carried out under reduced pressure to remove remaining monomers that were not used in the polymerization, thereby terminating the polymerization. During the polymerization, PHP, EDTA, and FE were each added to the pressure-resistant polymerization reactor in desired amounts and at desired times. This polymerization procedure yielded a latex (R-2) containing a core layer (polybutadiene rubber particles) composed primarily of polybutadiene rubber. The volume average particle diameter of the polybutadiene rubber particles contained in the obtained latex was 0.20 μm.

[0274] 2. Preparation of Component (B) (Component (b1) (Polymer Particles)) (Formation of Shell Layer) Production Example 2-1: Preparation of Aqueous Latex (L-1) Containing Polymer Particles 271 parts by mass of the polybutadiene rubber latex (R-2) prepared in Production Example 1-2 (containing 90 parts by mass of polybutadiene rubber particles) and 51 parts by mass of deionized water were placed in a glass reactor. The glass reactor was equipped with a thermometer, a stirrer, a reflux condenser, a nitrogen inlet, and a monomer addition device. The gas in the glass reactor was replaced with nitrogen, and the raw materials placed in were stirred at 60°C while the nitrogen replacement was being carried out. 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 to the glass reactor. Thereafter, a mixture of shell layer-forming monomers (9.25 parts by mass of methyl methacrylate (MMA) and 0.75 parts by mass of GMA) and 0.14 parts by mass of CHP was continuously added to the glass reactor over 120 minutes. After completion of the addition, 0.04 parts by mass of CHP was added to the glass reactor, and the mixture in the glass reactor was continuously stirred for an additional 2 hours to complete the polymerization. By the above operations, an aqueous latex (L-1) containing component (B) (component (b1) (polymer particles)) was obtained. The polymerization conversion rate of the monomer components was 99% or more. The volume average particle diameter of the polymer particles contained in the obtained aqueous latex (L-1) was 0.21 μm. The content of epoxy groups relative to the total amount of the shell layer of the polymer particles was 0.5 mmol / g.

[0275] Production Example 2-2: Preparation of Aqueous Latex (L-2) Containing Polymer Particles 262 parts by mass of the polybutadiene rubber latex (R-2) prepared in Production Example 1-2 (containing 87 parts by mass of polybutadiene rubber particles) and 57 parts by mass of deionized water were charged into a glass reactor. The glass reactor was equipped with a thermometer, a stirrer, a reflux condenser, a nitrogen inlet, and a monomer addition device. The gas in the glass reactor was replaced with nitrogen, and the charged raw materials were stirred at 60°C while the nitrogen replacement was being carried out. 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 to the glass reactor. Thereafter, a mixture of shell layer-forming monomers (8 parts by mass of MMA, 3.5 parts by mass of butyl acrylate (BA), and 1.5 parts by mass of glycidyl methacrylate (GMA)) and 0.04 parts by mass of cumene hydroperoxide (CHP) was continuously added to the glass reactor over 120 minutes. After the addition was completed, 0.04 parts by mass of CHP was added to the glass reactor, and the mixture in the glass reactor was continuously stirred for an additional 2 hours to complete the polymerization. Through the above operations, an aqueous latex (L-2) containing component (B) (component (b1) (polymer particles)) was obtained. The polymerization conversion rate of the monomer components was 99% or higher. The volume average particle diameter of the polymer particles contained in the obtained aqueous latex (L-2) was 0.21 μm. The epoxy group content relative to the total amount of the shell layer of the polymer particles was 0.8 mmol / g.

[0276] Production Example 2-3: Preparation of aqueous latex (L-3) containing polymer particles

[0077] An aqueous latex (L-3) containing component (B) (component (b1) (polymer particles)) was obtained in the same manner as in Production Example 2-2, except that 1 part by mass of MMA, 6 parts by mass of styrene (ST), 2 parts by mass of acrylonitrile (AN), and 4 parts by mass of GMA were used instead of 8 parts by mass of MMA, 3.5 parts by mass of BA, and 1.5 parts by mass of GMA as the shell layer-forming monomers in Production Example 2-2. The volume average particle diameter of the polymer particles contained in the obtained aqueous latex (L-3) was 0.21 μm. The epoxy group content relative to the total mass of the shell layer of the polymer particles was 2.2 mmol / g.

[0277] 3. Preparation of Dispersion (M) in Which Polymer Particles Are Dispersed in Component (A) Production Example 3-1: Preparation of Dispersion (M-(1)) 132 g of methyl ethyl ketone (MEK) was introduced into a 1 L mixing tank at 25°C. Next, while stirring the MEK, 132 g of the aqueous latex (L-1) containing polymer particles obtained in Production Example 2-1 (containing 40 g of polymer particles) was added to the mixing tank. After the raw materials in the mixing tank were uniformly mixed, 200 g of water was added to the mixing tank at a feed rate of 80 g / min while stirring the raw materials in the mixing tank. After the water supply was completed, stirring was promptly stopped to obtain a slurry liquid consisting of aggregates containing polymer particles and an aqueous phase containing a small amount of organic solvent. The aggregates were floatable. Next, 360 g of the aqueous phase was discharged from a discharge port at the bottom of the mixing tank, leaving a portion of the aggregates containing the aqueous phase in the mixing tank. 90 g of MEK was added to the obtained aggregates and mixed uniformly to obtain a dispersion in which polymer particles were uniformly dispersed in MEK. 60 g of A-(1) (a bifunctional bisphenol A epoxy resin that is liquid at room temperature), which is component (A), was added to the obtained dispersion and mixed uniformly. MEK was removed from the obtained mixture using a rotary evaporator. In this way, a dispersion (M-(1)) in which component (B) (component (b1) (polymer particles)) was dispersed in component (A) was obtained.

[0278] Production Example 3-2: Preparation of Dispersion (M-(2)) A dispersion (M-(2)) in which component (B) (component (b1) (polymer particles)) was dispersed in component (A) was obtained in the same manner as in Production Example 3-1, except that (L-2) obtained in Production Example 2-2 was used instead of (L-1) as the aqueous latex containing polymer particles, and 48.9 g of epoxy resin (A-(1)) was used instead of 60 g of epoxy resin (A-(1)).

[0279] Production Example 3-3: Preparation of Dispersion (M-(3)) A dispersion (M-(3)) in which component (B) (component (b1) (polymer particles)) was dispersed in component (A) was obtained in the same manner as in Production Example 3-1, except that 132 g of (L-3) (containing 40 g of polymer particles) obtained in Production Example 2-3 was used instead of (L-1) as the aqueous latex containing polymer particles in Production Example 3-1.

[0280] [Component (b2); Blocked Urethane] b2-(1): Flexibilizer DY 965 (manufactured by Huntsman, blocked urethane containing a polytetramethylene glycol structure, polystyrene-equivalent number average molecular weight (Mn): 11,800, molecular weight distribution (Mw / Mn): 2.1, measured by GPC (apparatus: Tosoh HLC-8420, column: Tosoh TSKgel Super HZ column, mobile phase: THF, column temperature: 40°C, flow rate: 0.35 ml / min, injection volume: 10 μL, detector: differential refractometer) [Component (b3); Rubber-modified Epoxy Resin] b3-(1): Hypox RA 1340 (manufactured by Huntsman, rubber-modified epoxy resin, epoxy equivalent: 325 g / eq to 375 g / eq) [Component (b4); Urethane-modified Epoxy Resin] b4-(1): EPU-73B (manufactured by ADEKA, urethane-modified epoxy resin, epoxy equivalent: 245 g / eq).

[0281] <Component (C)> [Component (c1); Alicyclic Amine] c1-(1): 4,4'-methylenebis(cyclohexylamine) (mixture of isomers) (manufactured by Tokyo Chemical Industry Co., Ltd., active hydrogen equivalent: 52.6 g / eq) c1-(2): Isophoronediamine (manufactured by BASF, active hydrogen equivalent: 42.6 g / eq) [Component (c2); Polyamidoamine] c2-(1): Sunmide DT-200 (manufactured by Evonik, active hydrogen equivalent: 70 g / eq) c2-(2): Ancamide 350A (manufactured by Evonik, active hydrogen equivalent: 100 g / eq) [Component (c3); Amine-terminated butadiene nitrile rubber] c3-(1): Hypro 1300X16 ATBN (manufactured by Huntsman, amine-terminated butadiene-acrylonitrile copolymer, molecular weight: approximately 3800, active hydrogen equivalent: 800 g / eq to 1000 g / eq) [Epoxy curing agents other than components (c1), (c2), and (c3)] c-(1): 3-diethylaminopropylamine (manufactured by Tokyo Chemical Industry Co., Ltd., active hydrogen equivalent: 65.1 g / eq) c-(2): Jeffamine D-230 (manufactured by Huntsman, poly(oxypropylene)diamine, active hydrogen equivalent: 60 g / eq) c-(3): triethylenetetramine (manufactured by Tokyo Chemical Industry Co., Ltd., active hydrogen equivalent: 24 g / eq) <Component (D)> [Epoxy-based reactive diluent having two epoxy groups per molecule] D-(1): YED216M (manufactured by Mitsubishi Chemical Co., Ltd., 1,D-(2): PG-207 (manufactured by Nippon Steel Chemical & Material, polypropylene glycol diglycidyl ether, epoxy equivalent: 315 g / eq) D-(3): Epoite 100E (manufactured by Kyoeisha Chemical, diethylene glycol diglycidyl ether, epoxy equivalent: 151 g / eq) D-(4): Epoite 400P (manufactured by Kyoeisha Chemical, polypropylene glycol diglycidyl ether, epoxy equivalent: 306 g / eq) [Epoxy-based reactive diluent having one epoxy group per molecule] D-(5): ERISYS (registered trademark) GE-10 (manufactured by Huntsman, o-cresyl glycidyl ether, epoxy equivalent: 182 g / eq) D-(6): Cardula (registered trademark) E10P (manufactured by Hexion, neodecanoic acid glycidyl ester, epoxy equivalent: 245 g / eq) D-(7): Denacol (registered trademark) EX-121 (manufactured by Nagase ChemteX, 2-ethylhexyl glycidyl ether, epoxy equivalent: 187 g / eq) <Other components> [Curing accelerator] Ancamine K54 (manufactured by Evonik, 2,4,6-tris(dimethylaminomethyl)phenol, tertiary amine) [Silane coupling agent] DOWSIL Z-6040 Silane (manufactured by Dow Corning Toray, 3-glycidoxypropyltrimethoxysilane) [Heavy calcium carbonate] Whiten SB (manufactured by Shiraishi Calcium, average particle size: 1.8 μm) [Fume silica] CAB-O-SIL TS-720 (manufactured by CABOT, fumed silica surface-treated with polydimethylsiloxane). ,

[0282] [Measurement and Evaluation Methods] The measurement and evaluation methods for each physical property measured in the examples are shown below.

[0283] [Measurement of Volume Average Particle Diameter] The volume average particle diameter (Mv) of the polymer particles (B) dispersed in the aqueous latex was measured using a Microtrac UPA150 (manufactured by Nikkiso Co., Ltd.). A sample prepared by diluting the aqueous latex with deionized water was used. The measurement was performed by inputting the refractive index of water and the refractive index of each polymer particle, adjusting the sample concentration so that the measurement time was 600 seconds, and the signal level was within the range of 0.6 to 0.8.

[0284] [Measurement of Fracture Toughness (K1c, G1c)] Each curable resin composition in Tables 1 and 2 was poured between two fluorine-coated aluminum plates (dimensions: 25 cm × 25 cm × 0.5 cm) sandwiching a 5 mm thick spacer, and then cured under the curing conditions (curing temperature, curing time) described in Tables 1 and 2 to obtain a 5 mm thick plate-shaped cured product. The cured product was cut into a size of 2.5 inches long, 0.5 inches wide, and 5 mm thick to prepare a test specimen. A V-notch was made in the test specimen, and a crack was made from the tip of the V-notch to the center of the specimen using a razor blade. The test specimens thus obtained were subjected to a three-point bending test under conditions of a support distance of 50 mm, a test speed of 1 mm / min, and 23°C. From the bending test results, the fracture toughness values ​​(K1c and G1c) were evaluated in accordance with ASTM D-5045.

[0285] [Measurement of Impact Peel Strength] According to the formulations shown in Tables 3 to 5 and 7, each component was weighed and thoroughly mixed to obtain the first and second components of a two-component curable resin composition. Next, the first and second components in Tables 3 to 5 and 7 were thoroughly mixed to obtain a curable resin composition. The obtained curable resin composition was applied to two cold-rolled steel plates, which were then stacked so that the thickness of the curable resin composition was 0.25 mm. The curable resin composition was cured under the curing conditions (curing temperature, curing time) shown in Tables 3 to 5 and 7 to obtain a laminate. Using this laminate, the dynamic splitting resistance (impact peel strength) was measured at 23°C in accordance with ISO 11343, and the toughness of the cured product (adhesive layer) was evaluated.

[0286] [Measurement of T-Peel Adhesion Strength] Each component was weighed and thoroughly mixed according to the formulations shown in Tables 5 and 6 to obtain the first and second components of a two-component curable resin composition. The first and second components shown in Tables 5 and 6 were then thoroughly mixed to obtain a curable resin composition. The resulting curable resin composition was applied to two cold-rolled steel plates (SPCC steel plates) measuring 25 mm wide x 200 mm long x 0.5 mm thick, and the two cold-rolled steel plates were then overlapped so that the adhesive layer was 0.25 mm thick. The composition between the two cold-rolled steel plates was then cured under the curing conditions (curing temperature, curing time) listed in Tables 5 and 6 to obtain a laminate. The resulting laminate was used as a sample to measure the T-peel adhesion strength (N / 25 mm) according to JIS K6854, and the toughness of the cured product (adhesive layer) was evaluated. The measurement conditions were a temperature of 23°C and a test speed of 254 mm / min.

[0287] [Measurement of Shear Adhesion Strength] Each component was weighed according to the formulation shown in Table 6 and thoroughly mixed to obtain the first and second components of a two-component curable resin composition. The first and second components in Table 6 were then thoroughly mixed to obtain a curable resin composition. The resulting curable resin composition was applied to two cold-rolled steel plates (SPCC steel plates) measuring 25 mm wide x 100 mm long x 1.6 mm thick, and the two cold-rolled steel plates were then superimposed so that the adhesive layer was 0.25 mm thick. The composition between the two cold-rolled steel plates was then cured under the curing conditions (curing temperature, curing time) shown in Table 6 to obtain a laminate. The resulting laminate was used as a sample, and the shear adhesive strength (MPa) was measured using an Autograph AG-2000E (manufactured by Shimadzu Corporation) in accordance with JIS K6850 to evaluate the toughness of the cured product (adhesive layer). The measurement conditions were a measurement temperature of 23° C. and a test speed of 1.3 mm / min.

[0288] [Measurement of Glass Transition Temperature (Tg) and Storage Modulus at 70°C] For the compositions in Tables 1 and 2, each 5 mm thick plate-shaped cured product obtained in the above [Measurement of Fracture Toughness (K1c, G1c)] was cut into a length of 40 mm, a thickness of 5 mm, and a width of 3 mm to prepare a test specimen.

[0289] The first and second components shown in Tables 3 to 7 were thoroughly mixed to obtain curable resin compositions. The obtained curable resin compositions were poured between two fluorine-coated steel plates (dimensions: 10 cm x 2.5 cm x 0.5 cm) sandwiching a 0.3 mm thick spacer. The curable resin compositions were then cured under the curing conditions (curing temperature, curing time) shown in Tables 3 to 7 to obtain 0.3 mm thick plate-shaped cured products. Each cured product was cut into a length of 30 mm, width of 5 mm, and thickness of 0.3 mm to obtain test specimens.

[0290] Dynamic viscoelasticity measurements were performed on the obtained test pieces using a dynamic viscoelasticity measuring device, ITK DVA-200 (IT Measurement & Control Co., Ltd.), in tension mode at a frequency of 1 Hz, with the temperature rising at a rate of 8°C / min. From the obtained results, the temperature (°C) at which the loss tangent (tan δ) was maximized was defined as the glass transition temperature (Tg). From the obtained results, the storage modulus (GPa) at 70°C was also measured, and the heat resistance of the cured product was evaluated.

[0291] [Measurement of degree of cure of cured product by DSC] 10 mg of each curable resin composition in Tables 1 and 2 was sampled. For the compositions in Tables 3, 4, and 6, 10 mg of each curable resin composition obtained by thoroughly mixing the first component and the second component was sampled. The curable resin composition was measured by increasing the temperature from 30°C to 250°C at a heating rate of 10°C / min using DSC, and an exothermic curve was obtained. The exothermic peak of the exothermic curve was integrated to calculate the total calorific value QT of each curable resin composition.

[0292] Next, for the compositions in Tables 1 and 2, the cured products were obtained in the form of 5 mm thick plates as obtained in the above [Measurement of fracture toughness (K1c, G1c)]. Each cured product was cut into a length of 3.0 mm, a thickness of 1.5 mm, and a width of 2.5 mm to prepare test specimens.

[0293] For the compositions in Tables 3, 4, and 6, each 0.3 mm thick plate-shaped cured product obtained in the above "Measurement of glass transition temperature (Tg) and storage modulus at 70°C" was cut into a size of 3.0 mm length × 0.3 mm thickness × 2.5 mm width. Five of these small plate-shaped cured products were stacked to form a test specimen.

[0294] The obtained test pieces were measured using a DSC by increasing the temperature from 30°C to 250°C at a heating rate of 10°C / min to obtain heat release curves. The heat release peaks of the heat release curves were integrated to calculate the residual heat release value QR of each cured product.

[0295] The degree of cure (%) of the cured product obtained by DSC was calculated based on the following formula: Degree of cure (%)={(QT-QR) / QT}×100.

[0296] (Examples 1 to 7, Comparative Examples 1 to 3, Reference Examples 1 and 2) Each component was weighed and thoroughly mixed to obtain the formulation shown in Tables 1 and 2, thereby obtaining a curable resin composition. The degree of cure, fracture toughness (K1c and G1c), glass transition temperature (Tg), and storage modulus at 70°C of the obtained curable resin composition were measured and evaluated according to the methods described above. The results are shown in Tables 1 and 2.

[0297] (Examples 8 to 28, Comparative Examples 4 to 12) Each component was weighed according to the formulations shown in Tables 3 to 7 and thoroughly mixed to obtain the first and second components of two-component curable resin compositions. The degree of cure, impact peel strength, T-peel adhesive strength, shear adhesive strength, glass transition temperature (Tg), and storage modulus at 70°C of the obtained curable resin compositions were measured and evaluated according to the methods described above. The results are shown in Tables 3 to 7.

[0298] According to one embodiment of the present invention, it is possible to provide a curable resin composition that can provide a cured product that has an excellent balance between heat resistance and toughness when cured at low temperatures. Therefore, the curable resin composition according to one embodiment of the present invention can be preferably used in applications such as adhesives (e.g., vehicle adhesives (structural adhesives) for vehicles and aircraft, adhesives for secondary batteries such as EV battery cells, structural adhesives for wind power generation, etc.), paints, materials for impregnating glass fibers and / or carbon fibers to obtain composite materials, materials for printed wiring boards, solder resists, interlayer insulating films, build-up materials, FPC adhesives, electrically insulating materials such as encapsulants for electronic components such as semiconductors and LEDs, die bond materials, underfills, mounting materials for semiconductors (e.g., ACF, ACP, NCF, NCP, etc.), encapsulants for display devices (e.g., liquid crystal panels and OLED displays, etc.), encapsulants for lighting devices (e.g., OLED lighting, etc.), composite materials for concrete repair, and coating materials (e.g., concrete coating materials).

Claims

1. A curable resin composition for low-temperature curing, comprising the following components (A), (B), (C), and (D): component (A): an epoxy resin; component (B): one or more selected from the group consisting of the following components (b1), (b2), (b3), and (b4); component (b1): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (b2): blocked urethane; component (b3): ​​rubber-modified epoxy resin; component (b4): urethane-modified epoxy resin; component (C): epoxy curing agent; component (D): epoxy-based reactive diluent; satisfying the following (1) and / or (2): (1) the component (C) comprises the following component (c1): component (c1): alicyclic amine; the content of the component (c1) is 25% by mass to 100% by mass in 100% by mass of the component (C); (2) The component (C) contains the following component (c2): component (c2): polyamidoamine; the active hydrogen equivalent of the component (C) is 50 g / eq to 90 g / eq, and the content of the component (c2) is 25 mass% to 100 mass% relative to 100 mass% of the component (C).

2. A two-component or multi-component curable resin composition for low-temperature curing, comprising a first component and a second component, wherein the first component comprises the following components (A) and (D): component (A): an epoxy resin; component (D): an epoxy-based reactive diluent; the second component comprises the following component (C): component (C): an epoxy curing agent; the curable resin composition further comprises the following component (B): component (B): one or more selected from the group consisting of the following components (b1), (b2), (b3), and (b4): component (b1): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (b2): blocked urethane; component (b3): ​​rubber-modified epoxy resin; component (b4): urethane-modified epoxy resin; A two-component or multi-component curable resin composition for low-temperature curing, satisfying the following (1) and / or (2): (1) the component (C) comprises the following component (c1): (c1) component: alicyclic amine; the content of the (c1) component is 25% by mass to 100% by mass of 100% by mass of the (C) component; (2) the (C) component includes the following (c2) component: (c2) component: polyamidoamine; the active hydrogen equivalent of the (C) component is 50 g / eq to 90 g / eq, and the content of the (c2) component is 25% by mass to 100% by mass of 100% by mass of the (C) component.

3. The curable resin composition according to claim 1 or 2, wherein the component (C) further comprises the following component (c3): Component (c3): Amine-terminated butadiene nitrile rubber.

4. A curable resin composition according to claim 1 or 2, wherein the core layer of component (b1) comprises one or more rubbers selected from the group consisting of diene rubbers, (meth)acrylate rubbers, and organosiloxane rubbers.

5. A curable resin composition according to claim 1 or 2, wherein the content of the component (B) is 1 to 200 parts by mass per 100 parts by mass of the component (A).

6. The curable resin composition according to claim 1 or 2, wherein the component (c1) comprises one or more selected from the group consisting of isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), N-aminoethylpiperazine, piperazine, and menthenediamine.

7. The curable resin composition according to claim 1 or 2, wherein the content of the component (C) is 5 to 100 parts by mass per 100 parts by mass of the component (A).

8. A curable resin composition according to claim 1 or 2, wherein the content of the component (c1) is 3.5% by mass to 30.0% by mass relative to 100% by mass of the total amount of the curable resin composition.

9. The curable resin composition according to claim 1 or 2, wherein the content of the component (D) is 1.0 to 100.0 parts by mass per 100 parts by mass of the component (A).

10. A curable resin composition according to claim 1 or 2, further comprising 5 to 300 parts by mass of calcium carbonate per 100 parts by mass of component (A).

11. Use of the curable resin composition according to claim 1 or 2 as one or more materials selected from the group consisting of adhesives, impregnation materials and coating materials.

12. Use of a curable resin composition, comprising a step of curing the curable resin composition according to claim 1 or 2 at a low temperature.

13. A method for producing a cured product, comprising a step of curing the curable resin composition according to claim 1 or 2 at a low temperature.

14. A cured product obtained by curing a curable resin composition containing the following components (A), (B), (C), and (D): component (A): an epoxy resin; component (B): one or more selected from the group consisting of the following components (b1), (b2), (b3), and (b4); component (b1): polymer particles having a core-shell structure containing a core layer and a shell layer; component (b2): blocked urethane; component (b3): ​​rubber-modified epoxy resin; component (b4): urethane-modified epoxy resin; component (C): epoxy curing agent; component (D): epoxy-based reactive diluent; the degree of cure measured by differential scanning calorimetry (DSC) is 50% to 95%, and the curable resin composition satisfies the following (1) and / or (2): (1) the component (C) contains the following component (c1): component (c1): alicyclic amine; (2) The component (C) contains the following component (c2): component (c2): polyamidoamine; the active hydrogen equivalent of the component (C) is 50 g / eq to 90 g / eq.

15. The cured product according to claim 14, wherein the content of the (c1) component and / or the (c2) component is 25% by mass to 100% by mass relative to 100% by mass of the (C) component.

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