Curable resin composition and use therefor

Abstract

The problem addressed is to provide a curable resin composition capable of providing a cured product excellent in toughness. Provided is a curable resin composition that contains specific amounts of component (A): a specific epoxy group-containing substance, component (B): polymer particles having a specific structure, and component (C): a specific epoxy curing agent, in which component (D): curing accelerator is not contained or is contained in a specific amount, and the values X or Y are within specific ranges.

Description

Curable resin composition and use thereof

[0001] The present invention relates to a curable resin composition and its use.

[0002] Curable resin compositions containing epoxy resins are used in the fields of fiber-reinforced composite materials and fiber-reinforced molded articles, as described in, for example, Patent Documents 1 to 7.

[0003] Japanese Patent Application Laid-Open No. 2018-35210 Japanese Patent Application Laid-Open No. 2023-502717 Japanese Patent Application Laid-Open No. 2023-139383 Japanese Patent Application Laid-Open No. 2021-116404 Japanese Patent Application Laid-Open No. 2023-146870 International Publication WO2023 / 089997 Japanese Patent Application Laid-Open No. 8-183836

[0004] However, the above-mentioned conventional techniques are not sufficient from the viewpoint of toughness of the cured product, and there is room for further improvement.

[0005] 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 with excellent toughness.

[0006] The present inventors have conducted extensive research to solve the above problems and have completed the present invention.

[0007] That is, a curable resin composition according to one embodiment of the present invention comprises the following components (A) and (B), and does not comprise the following component (D), or further comprises the following component (D): component (A): an epoxy group-containing substance comprising one or more selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins; component (B): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (D): a curing accelerator; and satisfies at least one of the following (1) to (3): (1) further comprises the following component (C), component (C): an acid anhydride (c1), an aromatic amine (c2), or an alicyclic amine (c3); the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 60 parts by mass to 100 parts by mass in 100 parts by mass of the component (A), and the content of the component (B) is 1 part by mass to 100 parts by mass relative to 100 parts by mass of the component (A), the content of the component (C) is 5 parts by mass to 200 parts by mass relative to 100 parts by mass of the component (A), and when the component (D) is contained, the content of the component (D) is 0.1 parts by mass to 10.0 parts by mass relative to 100 parts by mass of the component (A), and the value X calculated by the following formula is 1.05 to 5.50 when the component (C) is the acid anhydride (c1), and 1.30 to 9.00 when the component (C) is the aromatic amine (c2) or the alicyclic amine (c3); Formula: X={[273+Tmin(M)] / [273+Tmin(Meq)]} ×[E'(Meq)] / [E'(M)]; (2) further containing the following component (C), Component (C): an epoxy curing agent containing one or more selected from the group consisting of acid anhydrides (c1), aromatic amines (c2), and alicyclic amines (c3); the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 5 parts by mass to 100 parts by mass per 100 parts by mass of component (A), and the content of component (B) is 1 part by mass to 100 parts by mass per 100 parts by mass of component (A),the content of the component (C) is 10 parts by mass to 200 parts by mass relative to 100 parts by mass of the component (A); when the component (D) is contained, the content of the component (D) is 0.1 parts by mass to 10.0 parts by mass relative to 100 parts by mass of the component (A); the component (A) satisfies any of the following (i), (ii), or (iii); (i) the component (A) contains a polyfunctional epoxy group-containing substance (a1) having an epoxy equivalent of 300 g / eq or more and less than 3000 g / eq and having two or more epoxy groups in one molecule, and the content of the polyfunctional epoxy group-containing substance (a1) is 5 parts by mass to 100 parts by mass relative to 100 parts by mass of the component (A); (ii) the component (A) contains a monofunctional epoxy group-containing substance (a2) having one epoxy group per molecule, and the content of the monofunctional epoxy group-containing substance (a2) is 5 to 95 parts by mass per 100 parts by mass of the component (A); (iii) the component (A) contains the polyfunctional epoxy group-containing substance (a1) and the monofunctional epoxy group-containing substance (a2), and the content of the polyfunctional epoxy group-containing substance (a1) is 5 to 95 parts by mass per 100 parts by mass of the component (A), and the content of the monofunctional epoxy group-containing substance (a2) is 5 to 95 parts by mass per 100 parts by mass of the component (A); the value Y calculated by the following formula is 22 to 400; Formula: Y = [273 + Tmin(M)] / [E'(M)]; (3) further contains the following component (C), Component (C): an amine-based epoxy curing agent containing an amine (c4) having one or two active hydrogen atoms in the amino group per molecule; the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 5 to 100 parts by mass per 100 parts by mass of the component (A), the content of the component (B) is 1 to 100 parts by mass per 100 parts by mass of the component (A), the content of the component (C) is 10 to 200 parts by mass per 100 parts by mass of the component (A), and when the component (D) is contained, the content of the component (D) is 0.1 to 20.0 parts by mass per 100 parts by mass of the component (A),the content of the amine (c4) in the component (C) is 5% by mass to 100% by mass, based on 100% by mass of the component (C), and the value Y calculated by the following formula is 22 to 400; Y=[273+Tmin(M)] / [E'(M)]; wherein, in the formula for the value X and the formula for the value Y, Ttg(M) (°C) is the temperature at which the loss tangent is maximized when dynamic viscoelasticity is measured using a cured product (M) of composition (M) as a sample in a tensile mode at a frequency of 1 Hz, E'(M) represents the minimum value of the storage modulus (E') of the cured product (M) in the temperature range of [Ttg(M) (°C)] to [Ttg(M)+25(°C)], and Tmin(M) (°C) is the temperature (°C) at which the value of E'(M) is obtained, the composition (M) contains the component (A), the component (C), and the component (D) that are the same as the component (A), the component (C), and the component (D) contained in the curable resin composition, the contents of the component (A), the component (C), and the component (D) in the composition (M) are the same as the contents of the component (A), the component (C), and the component (D) in the curable resin composition, the cured product (M) is a cured product obtained by curing the composition (M) and exhibits a degree of cure of 98% or more as measured by DSC, and in the formula for the value X, wherein Ttg(Meq) (°C) is the temperature at which the loss tangent obtained by performing dynamic viscoelasticity measurement on a cured product (Meq) of composition (Meq) as a sample under conditions of tensile mode and a frequency of 1 Hz is maximized, E'(Meq) represents the minimum value of the storage modulus (E') of the cured product (Meq) in the temperature range of [Ttg(Meq) (°C)] to [Ttg(Meq) + 25 (°C)], and Tmin(Meq) (°C) is the temperature (°C) at which the value of E'(Meq) is obtained, and the composition (Meq) contains the same component (A), component (C), and component (D) as the component (A), component (C), and component (D) contained in the curable resin composition, the contents of the component (A) and the component (D) in the composition (Meq) are the same as the contents of the component (A) and the component (D) in the curable resin composition,When the component (C) in the composition (Meq) is the acid anhydride (c1), the content of the component (C) in the composition (Meq) is an amount such that the ratio of the molar amount of acid anhydride groups in the component (C) to the molar amount of epoxy groups in the component (A) contained in the composition (Meq) (molar amount of acid anhydride groups in the component (C) / molar amount of epoxy groups in the component (A)) is 1; when the component (C) in the composition (Meq) is the aromatic amine (c2) or the alicyclic amine (c3), the content of the component (C) in the composition (Meq) is an amount such that the ratio of the molar amount of active hydrogen of the amine in the component (C) to the molar amount of epoxy groups in the component (A) contained in the composition (Meq) (molar amount of active hydrogen of the amine in the component (C) / molar amount of epoxy groups in the component (A)) is 1; The cured product (Meq) is a cured product obtained by curing the composition (Meq), and exhibits a degree of cure of 98% or more as measured by DSC.

[0008] According to one embodiment of the present invention, it is possible to provide a novel curable resin composition that can provide a cured product having excellent toughness.

[0009] 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)."

[0010] In this specification, the "curable resin composition" may be referred to as the "composition", and the "curable resin composition according to one embodiment of the present invention" may be referred to as the "composition" hereinafter.

[0011] In this specification, the term "X unit" contained in a polymer, copolymer, or resin refers to a "structural unit derived from an X monomer." For example, the term "butadiene unit" refers to a "structural unit derived from a butadiene monomer."

[0012] [1. Curable Resin Composition] A curable resin composition according to one embodiment of the present invention contains the following components (A) and (B), and does not contain the following component (D), or further contains the following component (D).

[0013] Component (A): an epoxy group-containing substance containing one or more selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins; Component (B): polymer particles having a core-shell structure containing a core layer and a shell layer; Component (D): a curing accelerator; A curable resin composition according to one embodiment of the present invention satisfies at least one of the following requirements (1) to (3):

[0014] (1) The composition further comprises the following component (C): component (C) is an acid anhydride (c1), an aromatic amine (c2), or an alicyclic amine (c3); the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 60 to 100 parts by mass per 100 parts by mass of the component (A), the content of the component (B) is 1 to 100 parts by mass per 100 parts by mass of the component (A), the content of the component (C) is 5 to 200 parts by mass per 100 parts by mass of the component (A), and when the component (D) is contained, the content of the component (D) is 0.1 to 10.0 parts by mass per 100 parts by mass of the component (A), and the value X calculated by the following formula is 1.05 to 5.50 when the component (C) is the acid anhydride (c1), When the component (C) is the aromatic amine (c2) or the alicyclic amine (c3), the molecular weight is 1.30 to 9.00; Formula: X={[273+Tmin(M)] / [273+Tmin(Meq)]}×[E'(Meq)] / [E'(M)].

[0015] (2) The composition further comprises the following component (C): component (C); an epoxy curing agent comprising one or more selected from the group consisting of acid anhydrides (c1), aromatic amines (c2), and alicyclic amines (c3); the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 5 to 100 parts by mass, relative to 100 parts by mass of the component (A); the content of the component (B) is 1 to 100 parts by mass, relative to 100 parts by mass of the component (A); the content of the component (C) is 10 to 200 parts by mass, relative to 100 parts by mass of the component (A); and when the component (D) is contained, the content of the component (D) is 0.1 to 10.0 parts by mass, relative to 100 parts by mass of the component (A); and the component (A) satisfies any of the following (i), (ii), or (iii): (i) the component (A) contains a polyfunctional epoxy group-containing substance (a1) having an epoxy equivalent of 300 g / eq or more and less than 3000 g / eq and having two or more epoxy groups in one molecule, and the content of the polyfunctional epoxy group-containing substance (a1) is 5 parts by mass to 100 parts by mass per 100 parts by mass of the component (A); (ii) the component (A) contains a monofunctional epoxy group-containing substance (a2) having one epoxy group in one molecule, and the content of the monofunctional epoxy group-containing substance (a2) is 5 parts by mass to 95 parts by mass per 100 parts by mass of the component (A); (iii) the component (A) comprises the polyfunctional epoxy group-containing substance (a1) and the monofunctional epoxy group-containing substance (a2), and the content of the polyfunctional epoxy group-containing substance (a1) is 5 to 95 parts by mass per 100 parts by mass of the component (A), and the content of the monofunctional epoxy group-containing substance (a2) is 5 to 95 parts by mass per 100 parts by mass of the component (A); the value Y calculated by the following formula is 22 to 400; Y=[273+Tmin(M)] / [E'(M)].

[0016] (3) An amine-based epoxy curing agent further comprising the following component (C): component (C): an amine-based epoxy curing agent comprising an amine (c4) having one or two active hydrogen atoms in the amino group per molecule; wherein, in 100 parts by mass of the component (A), the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 5 parts by mass to 100 parts by mass; the content of the component (B) is 1 part by mass to 100 parts by mass relative to 100 parts by mass of the component (A); the content of the component (C) is 10 parts by mass to 200 parts by mass relative to 100 parts by mass of the component (A); when the component (D) is contained, the content of the component (D) is 0.1 parts by mass to 20.0 parts by mass relative to 100 parts by mass of the component (A); and the content of the amine (c4) in the component (C) is 5% by mass to 100% by mass relative to 100 parts by mass of the component (C); The value Y calculated by the following formula is 22 to 400; Y=[273+Tmin(M)] / [E'(M)].

[0017] The cured product obtained by curing composition (M) is referred to as "cured product (M)." Cured product (M) can also be referred to as "cured product (M) of composition (M)." Dynamic viscoelasticity measurement is performed on the cured product (M) as a sample under conditions of tensile mode and a frequency of 1 Hz. From this dynamic viscoelasticity measurement, the loss tangent and storage modulus are determined. The temperature at which the loss tangent of the cured product (M) is maximized is referred to as Ttg(M) (°C). In the above formula, E'(M) represents the minimum value of the storage modulus (E') of the cured product (M) in the temperature range of [Ttg(M) (°C)] to [Ttg(M) + 25 (°C)], and Tmin(M) (°C) is the temperature (°C) at which the value of E'(M) is obtained.

[0018] Composition (M) contains the same (identical) components (A), (C), and (D) as the components (A), (C), and (D) contained in the present composition. The contents of components (A), (C), and (D) in composition (M) are the same as the contents of components (A), (C), and (D) in the present composition. Composition (M) does not contain component (B).

[0019] In other words, when calculating the value X for a curable resin composition containing the components (A), (B), (C), and (D), the composition (M) used to calculate the value X (i) contains the same components (A), (C), and (D) as the components (A), (C), and (D) contained in the curable resin composition, (ii) does not contain the component (B) contained in the curable resin composition, and (iii) the contents of the components (A), (C), and (D) in the composition (M) are the same as the contents of the components (A), (C), and (D) in the curable resin composition. When calculating the value X for a curable resin composition that does not contain the component (D), the composition (M) used to calculate the value X does not contain the component (D).

[0020] Furthermore, when calculating the value Y for a curable resin composition containing the components (A), (B), (C), and (D), the composition (M) used to calculate the value Y (i) contains the same components (A), (C), and (D) as the components (A), (C), and (D) contained in the curable resin composition, (ii) does not contain the component (B) contained in the curable resin composition, and (iii) the contents of the components (A), (C), and (D) in the composition (M) are the same as the contents of the components (A), (C), and (D) in the curable resin composition. When calculating the value Y for a curable resin composition that does not contain the component (D), the composition (M) used to calculate the value Y does not contain the component (D).

[0021] The cured product obtained by curing the composition (Meq) is referred to as the "cured product (Meq)." The cured product (Meq) can also be referred to as the "cured product (Meq) of the composition (Meq)." The cured product (Meq) is used as a sample and subjected to dynamic viscoelasticity measurement under conditions of tensile mode and a frequency of 1 Hz. The loss tangent and storage modulus are determined from this dynamic viscoelasticity measurement. The temperature at which the loss tangent of the cured product (Meq) is maximized is referred to as Ttg(Meq) (°C). In the above formula, E'(Meq) represents the minimum value of the storage modulus (E') of the cured product (Meq) in the temperature range of [Ttg(Meq) (°C)] to [Ttg(Meq) + 25 (°C)], and Tmin(Meq) (°C) is the temperature (°C) at which the value of E'(Meq) is obtained.

[0022] Composition (Meq) contains components (A), (C), and (D) that are the same (identical) as the components (A), (C), and (D) contained in the present composition. Composition (Meq) does not contain component (B). The contents of components (A) and (D) in composition (Meq) are the same as the contents of components (A) and (D) in the present composition. When component (C) in composition (Meq) is acid anhydride (c1), the content of component (C) in composition (Meq) is an amount such that the ratio of the molar amount of acid anhydride groups in component (C) to the molar amount of epoxy groups in component (A) contained in composition (Meq) (molar amount of acid anhydride groups in component (C) / molar amount of epoxy groups in component (A)) is 1. When the component (C) in composition (Meq) is an aromatic amine (c2) or an alicyclic amine (c3), the content of the component (C) in composition (Meq) is an amount such that the ratio of the molar amount of active hydrogen of the amine in component (C) to the molar amount of epoxy groups in component (A) contained in composition (Meq) (molar amount of active hydrogen of the amine in component (C) / molar amount of epoxy groups in component (A)) is 1. The content of the component (D) in composition (Meq) is the same as the content of the component (D) in this composition. In other words, when calculating the value X for a curable resin composition containing the components (A), (B), (C), and (D), the composition (Meq) used to calculate the value X (i) contains the same components (A), (C), and (D) as the components (A), (C), and (D) contained in the curable resin composition, (ii) does not contain the component (B) contained in the curable resin composition, and (iii) the contents of the components (A) and (D) in the composition (Meq) are the same as the contents of the components (A) and (D) in the curable resin composition. When calculating the value X for a curable resin composition that does not contain the component (D), the composition (Meq) used to calculate the value X does not contain the component (D).

[0023] The present composition has the above-described structure, and therefore has the advantage of being able to provide a cured product with excellent toughness. In this specification, the toughness of the cured product is defined as the fracture toughness value "K1c (MPa m １／２ " and "G1c (Kj / m ２The higher the fracture toughness value of the cured product, the more excellent the toughness of the cured product.

[0024] In this specification, the term "cured product" refers to a cured product obtained by curing a curable resin composition, and has a degree of cure of 98% or more as measured by DSC. The same applies to the cured product (M) and cured product (Meq) used when calculating the values ​​X and Y. The fracture toughness value "K1c (MPa m １／２ " and "G1c (Kj / m ２ The same applies to the cured product for which the degree of cure is measured. For example, "cured product (M)" refers to a cured product obtained by curing composition (M) and exhibiting a degree of cure of 98% or more as measured by DSC. Furthermore, for example, "cured product (Meq)" refers to a cured product obtained by curing composition (Meq) and exhibiting a degree of cure of 98% or more as measured by DSC.

[0025] The values ​​X and Y may be affected by the degree of cure of the cured product (M) and the cured product (Meq) as measured by DSC. In this specification, the values ​​X and Y are calculated using a cured product (M) and a cured product (Meq) that have a degree of cure of 98% or more as measured by DSC. The degree of cure of the cured product as measured by DSC may be affected by the curing temperature and curing time of the composition (M). In calculating the values ​​X and Y, a cured product (M) and a cured product (Meq) having a degree of cure of 98% or more as measured by DSC can be obtained by curing the composition (M) and the composition (Meq) under the following curing conditions: when the component (C) is the acid anhydride (c1), for example, a curing temperature of 175°C and a curing time of 2 hours; when the component (C) is the aromatic amine (c2), for example, a curing temperature of 175°C and a curing time of 2 hours; when the component (C) is the alicyclic amine (c3), for example, a curing temperature of 120°C and a curing time of 2 hours; when the component (C) is an amine (c4) having one or two active hydrogen atoms in the amino group per molecule, for example, a curing temperature of 120°C and a curing time of 2 hours.

[0026] The degree of cure of the cured product is a curing reaction rate calculated from the total calorific value of the uncured curable resin composition measured using a DSC (differential scanning calorimeter) and the residual calorific value of the cured product obtained by curing the curable resin composition. A specific method for measuring the degree of cure of the cured product will be described in detail in the Examples below.

[0027] [1-1. Curable resin composition satisfying at least the above-mentioned (1)] In this section, a curable resin composition satisfying at least the above-mentioned (1) will be described below.

[0028] <1-1-1. Technical Concept Related to Curable Resin Compositions Satisfying at Least Requirement (1)> Conventionally known curable resin compositions have room for further improvement in terms of toughness. Therefore, the present inventors conducted extensive research with the aim of providing a novel curable resin composition that can provide a cured product having excellent toughness.

[0029] In a curable resin composition containing an epoxy group-containing substance (e.g., an epoxy resin), the crosslink density of the cured product is highest when the molar amount of the curing agent is equal to the molar amount of epoxy groups in the epoxy group-containing substance. For example, in a curable resin composition containing an epoxy group-containing substance and an acid anhydride as a curing agent, the crosslink density of the cured product is highest when the ratio of the molar amount of acid anhydride groups in the acid anhydride to the molar amount of epoxy groups in the epoxy group-containing substance is 1. For example, in a curable resin composition containing an epoxy group-containing substance and an aromatic amine or alicyclic amine as a curing agent, the crosslink density of the cured product is highest when the ratio of the molar amount of active hydrogen of the amine in the aromatic amine or alicyclic amine to the molar amount of epoxy groups in the epoxy group-containing substance is 1. The higher the crosslink density of the cured product, the smaller the molecular weight between crosslink points of the cured product. Therefore, it can be said that when the crosslink density of the cured product is highest, the molecular weight between crosslink points of the cured product is also lowest.

[0030] As a result of extensive research, the present inventors have independently and surprisingly obtained the novel finding that by adjusting the molecular weight between crosslink points of the cured product to a value within a specific range and by using polymer particles, the toughness of the cured product can be improved.

[0031] Here, for example, the "setting of the molecular weight between crosslink points of the cured product to a value within a specific range" will be explained using a curable resin composition (α) containing an epoxy group-containing substance (component (A)), polymer particles (component (B)), a curing agent (component (C)), and a curing accelerator (component (D)) as an example. First, a composition (α) (i.e., excluding component (B)) is prepared that contains the same components (A), (C), and (D) as the curable resin composition (α) in the same amounts as the curable resin composition (α). Next, a composition (αeq) (i.e., excluding component (B)) is prepared that contains the same components (A), (C), and (D) as the curable resin composition (α). In composition (αeq), the amounts of component (A) and component (D) are the same as those in the curable resin composition (α). In composition (αeq), the amount of component (C) is an amount such that the molar amount of functional groups in component (C) that react with epoxy groups (for example, acid anhydride groups when component (C) is an acid anhydride, or active hydrogen groups of amines when component (C) is an aromatic amine or alicyclic amine) is equivalent to the molar amount of epoxy groups in component (A). Setting the ratio of the inter-crosslinking molecular weight of the cured product (α) obtained by curing composition (α) to the inter-crosslinking molecular weight of the cured product (αeq) obtained by curing composition (αeq) (inter-crosslinking molecular weight of cured product (α) / inter-crosslinking molecular weight of cured product (αeq)) to a value within a specific range is referred to as "setting the inter-crosslinking molecular weight of the cured product to a value within a specific range."

[0032] The molecular weight between crosslinks of a cured product can be calculated from the theory of rubber elasticity of crosslinked rubber, for example, using the following formula: Molecular weight between crosslinks = 2 x (1 + μ) x ρ x R x T / E = ρ x R x T / G In the formula, μ represents the Poisson's ratio of the cured product, ρ represents the specific gravity of the cured product, R represents the gas constant, T represents absolute temperature (K), and E and G represent the Young's modulus and rigidity modulus in the rubber-like region of the cured product. The rubber-like region is a region observed on the higher temperature side than the transition region near the glass transition temperature when measuring the temperature dependence of the elastic modulus (Young's modulus, rigidity modulus, etc.), and represents a region in which the temperature dependence of the elastic modulus is flat. Since crosslinked polymers such as epoxy resin cured products do not have a flow region on the higher temperature side than the rubber-like region, E and G in the formula can be expressed as the minimum values ​​of the Young's modulus and rigidity modulus in the rubber-like region. Furthermore, since the Young's modulus in the rubber-like region is roughly equal to the storage modulus determined by dynamic viscoelasticity measurement, which is easy to measure, the molecular weight between crosslinks can be calculated by the following formula: Molecular weight between crosslinks = 2 × (1 + μ) × ρ × R × (273 + Tmin) / E'min In the formula, μ represents the Poisson's ratio of the cured product, ρ represents the specific gravity of the cured product, R represents the gas constant, E'min represents the minimum value of the storage modulus of the cured product, and Tmin represents the temperature (°C) at which the storage modulus of the cured product reaches its minimum value.

[0033] Therefore, the ratio of the inter-crosslinking molecular weight of the cured product (α) obtained by curing the composition (α) to the inter-crosslinking molecular weight of the cured product (α) obtained by curing the composition (αeq) (inter-crosslinking molecular weight of cured product (α) / inter-crosslinking molecular weight of cured product (αeq)) can be expressed by the following formula: Ratio = {2 × [1 + μ (cured product (α))] × ρ (cured product (α)) × R × [273 + Tmin (cured product (α))] / E'min (cured product (α))} / {2 × [1 + μ (cured product (αeq))] × ρ (cured product (αeq)) × R × [273 + Tmin (cured product (αeq))] / E'min (cured product (αeq))}.

[0034] Here, the only difference between the cured product (α) and the cured product (αeq) is the content of the component (C). The difference in the content of the component (C) does not significantly affect the Poisson's ratio (μ) and specific gravity (ρ) of the cured product. Therefore, in the above formula, μ(cured product (α)) and μ(cured product (αeq)) can be considered to have the same value, and ρ(cured product (α)) and ρ(cured product (αeq)) can be considered to have the same value. As a result, the ratio of the molecular weight between crosslinking points of the cured product (α) to the molecular weight between crosslinking points of the cured product (αeq) (molecular weight between crosslinking points of cured product (α) / molecular weight between crosslinking points of cured product (αeq)) can be represented by the following formula: Ratio = {[273 + Tmin (cured product (α))] / E'min (cured product (α))} / {[273 + Tmin (cured product (αeq))] / E'min (cured product (αeq))} = {[273 + Tmin (cured product (α))] / [273 + Tmin (cured product (αeq))]} × E'min (cured product (αeq)) / E'min (cured product (α)) In this specification, the above-mentioned ratio is represented by "X". That is, as a result of extensive research, the present inventors independently obtained the novel finding that, surprisingly, by setting X to a value within a predetermined range and using polymer particles, the toughness of the cured product can be improved, and have completed the present invention.

[0035] The evaluation of the inter-crosslink molecular weight must be based on measurements of a cured product obtained by curing a composition containing only components (A), (C), and (D). This is because components (A) and (C) form a crosslinked structure, and component (D) can affect the degree of progress of the crosslinking reaction. Conversely, when evaluating the inter-crosslink molecular weight, components other than component (B) and components (A) to (D) (e.g., inorganic fillers) cannot be added. This is because, despite not participating in crosslink formation, these components affect the E'min and other properties of the cured product obtained by curing the composition, preventing an accurate evaluation of the inter-crosslink molecular weight. Although component (D) is not incorporated into the crosslinked structure, its amount is small compared to the total amount of components (A) and (C) because it is a curing accelerator. Therefore, the influence of component (D) remaining unreacted after curing on the inter-crosslink molecular weight is thought to be small.

[0036] Previous attempts have been made to control mechanical properties such as toughness by varying the type of component (A) in the curable resin composition and the types and amounts of other additives. However, the present inventors first focused on the crosslink-to-crosslink molecular weight of the cured product, which had not previously been considered. By adjusting the crosslink-to-crosslink molecular weight to a value within a predetermined range and using polymer particles, they solved the above-mentioned problems and completed the present invention. It is known that dispersing polymer particles (B) in component (A) (e.g., epoxy resin) induces large-scale plastic deformation of the epoxy resin, consuming energy and improving toughness. It is presumed that adjusting the crosslink-to-crosslink molecular weight to a value within a predetermined range in the presence of polymer particles (B) facilitates plastic deformation of the cured product, significantly improving toughness. In other words, the technical concept of adjusting the crosslink-to-crosslink molecular weight to a value within a predetermined range can be said to be a technical concept that would not have been conceived of in the prior art.

[0037] 1-1-2. Component (A) The component (A) is an epoxy group-containing substance. In this specification, the term "epoxy group-containing substance" refers to a substance that has one or more epoxy groups in one molecule.

[0038] The epoxy group-containing substance (A) contains at least one selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins. This configuration has the advantages of providing a composition with a relatively low viscosity and excellent processability, and also of providing a cured product obtained by curing the composition with excellent strength, elastic modulus, and heat resistance (high Tg).

[0039] In this specification, an "epoxy group-containing substance having two or more epoxy groups in one molecule" may be referred to as a "polyfunctional epoxy group-containing substance," and an "epoxy group-containing substance having X epoxy groups in one molecule" may be referred to as an "X-functional epoxy group-containing substance."

[0040] The bisphenol A epoxy resin and bisphenol F epoxy resin in component (A) are each preferably independently a polyfunctional epoxy group-containing substance, more preferably a difunctional epoxy group-containing substance. This configuration has the advantage of a high toughness-improving effect due to control of the molecular weight between crosslinks. The alicyclic epoxy resin in component (A) is preferably a polyfunctional epoxy group-containing substance, more preferably a difunctional epoxy group-containing substance. This configuration has the advantages of the composition having a particularly low viscosity and excellent processability, as well as a high toughness-improving effect due to control of the molecular weight between crosslinks.

[0041] 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).

[0042] 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).

[0043] 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, and more preferably consists of only one or more selected from this group. More preferably, the alicyclic epoxy resin contains 3,4-epoxycyclohexylmethyl (3,4-epoxy)cyclohexanecarboxylate, and even more preferably consists of only 3,4-epoxycyclohexylmethyl (3,4-epoxy)cyclohexanecarboxylate.This configuration has the advantages that the composition has low viscosity and excellent processability, and further, the cured product obtained by curing the composition has excellent strength, elastic modulus, and heat resistance (high Tg).

[0044] The total content of the bisphenol A epoxy resin, bisphenol F epoxy resin, and alicyclic epoxy resin per 100 parts by mass of component (A) is 60 to 100 parts by mass, preferably 65 to 100 parts by mass, more preferably 70 to 100 parts by mass, more preferably 71 to 100 parts by mass, even more preferably 80 to 100 parts by mass, still more preferably 90 to 100 parts by mass, and particularly preferably 95 to 100 parts by mass. The upper limit of the total content of the bisphenol A epoxy resin, bisphenol F epoxy resin, and alicyclic epoxy resin per 100 parts by mass of component (A) may be less than 100 parts by mass. This configuration has the advantages of providing a composition with low viscosity and excellent processability, and further providing a cured product obtained by curing the composition with excellent strength, elastic modulus, and heat resistance (high Tg). The total content of bisphenol A epoxy resin, bisphenol F epoxy resin, and alicyclic epoxy resin may be 100 parts by mass per 100 parts by mass of component (A). In other words, component (A) may be composed solely of bisphenol A epoxy resin, solely of bisphenol F epoxy resin, solely of alicyclic epoxy resin, solely of bisphenol A epoxy resin and alicyclic epoxy resin, solely of bisphenol F epoxy resin and alicyclic epoxy resin, solely of bisphenol A epoxy resin and bisphenol F epoxy resin, or solely of bisphenol A epoxy resin, bisphenol F epoxy resin, and alicyclic epoxy resin. Component (A) does not necessarily contain other epoxy group-containing substances (e.g., glycidyl amine epoxy resin, etc.) described below.

[0045] Component (A) may further contain, in addition to one or more selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins, an epoxy group-containing substance other than bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins. Herein, "epoxy group-containing substances other than bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins" may also be referred to as "other epoxy group-containing substances." Examples of other epoxy group-containing substances include (i) polyfunctional epoxy group-containing substances other than bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins, and (ii) monofunctional epoxy group-containing substances other than alicyclic epoxy resins. Herein, "polyfunctional epoxy group-containing substances other than bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins" may also be referred to as "other polyfunctional epoxy group-containing substances." Herein, "monofunctional epoxy group-containing substances other than alicyclic epoxy resins" may also be referred to as "other monofunctional epoxy group-containing substances."

[0046] The component (A) may be (i) composed solely of bisphenol A epoxy resins and other epoxy group-containing substances, (ii) composed solely of bisphenol F epoxy resins and other epoxy group-containing substances, (iii) composed solely of alicyclic epoxy resins and other epoxy group-containing substances, (iv) composed solely of bisphenol A epoxy resins, alicyclic epoxy resins, and other epoxy group-containing substances, (v) composed solely of bisphenol F epoxy resins, alicyclic epoxy resins, and other epoxy group-containing substances, (vi) composed solely of bisphenol A epoxy resins, bisphenol F epoxy resins, and other epoxy group-containing substances, or (vii) composed solely of bisphenol A epoxy resins, bisphenol F epoxy resins, alicyclic epoxy resins, and other epoxy group-containing substances.

[0047] The other polyfunctional epoxy group-containing substances are not particularly limited. Examples of the other polyfunctional epoxy group-containing substances include commonly used epoxy resins other than bisphenol A type epoxy resins, bisphenol F type epoxy resins, and alicyclic epoxy resins, as well as the substances listed below: bisphenol AD ​​type epoxy resins, bisphenol S type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, novolac type epoxy resins, biphenyl type epoxy resins, oxazolidone type epoxy resins, biphenyl aralkyl type epoxy resins, bisnaphthalene type epoxy resins, glycidyl ether type epoxy resins of bisphenol A propylene oxide adducts, hydrogenated bisphenol A type epoxy resins, hydrogenated bisphenol F type epoxy resins, fluorinated epoxy resins, glycidyl ethers of tetrabromobisphenol A, and the like. flame-retardant epoxy resins such as benzoyl ether, p-oxybenzoic acid glycidyl ether ester type epoxy resins, m-aminophenol type epoxy resins, diaminodiphenylmethane-based epoxy resins, N,N-diglycidylaniline, N,N-diglycidyl-o-toluidine, triglycidyl isocyanurate, divinylbenzene dioxide, resorcinol diglycidyl ether, polyalkylene glycol diglycidyl ether, glycol diglycidyl ether, diglycidyl esters of aliphatic polybasic acids, glycidyl ethers of dihydric or higher polyhydric aliphatic alcohols such as glycerin, chelate-modified epoxy resins, rubber-modified epoxy resins, urethane-modified epoxy resins, hydantoin-type epoxy resins, epoxidized products of unsaturated polymers such as petroleum resins, and aminoglycidyl ether resins.

[0048] Epoxy compounds obtained by addition reaction of bisphenol A (or F) or polybasic acids with an epoxy resin such as a bisphenol A epoxy resin are also included in other polyfunctional epoxy group-containing substances (i.e., other epoxy group-containing substances).

[0049] More specific examples of glycidyl amine epoxy resins include N,N,O-triglycidyl-m-aminophenol, N,N,O-triglycidyl-p-aminophenol, N,N,O-triglycidyl-4-amino-3-methylphenol, N,N,N',N'-tetraglycidyl-4,4'-methylenedianiline, N,N,N',N'-tetraglycidyl-2,2'-diethyl-4,4'-methylenedianiline, N,N,N',N'-tetraglycidyl-m-xylylenediamine, N,N-diglycidylaniline, and N,N-diglycidyl-o-toluidine. More specific examples of polyalkylene glycol diglycidyl ethers include polyethylene glycol diglycidyl ether and polypropylene glycol diglycidyl ether. More specific examples of glycol diglycidyl ethers include neopentyl glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and cyclohexanedimethanol diglycidyl ether. More specific examples of diglycidyl esters of aliphatic polybasic acids include dimer acid diglycidyl ester, adipic acid diglycidyl ester, sebacic acid diglycidyl ester, and maleic acid diglycidyl ester. More specific examples of glycidyl ethers of dihydric or higher polyhydric aliphatic alcohols include trimethylolpropane triglycidyl ether, trimethylolethane triglycidyl ether, castor oil-modified polyglycidyl ether, propoxylated glycerin triglycidyl ether, and sorbitol polyglycidyl ether.

[0050] As the chelate-modified epoxy resin, for example, the resins described in paragraphs

[0018] to

[0019] of WO2016-163491 can be used.

[0051] The rubber-modified epoxy resin is a reaction product obtained by reacting rubber with an epoxy group-containing compound, and has an average of 1.1 or more epoxy groups per molecule, preferably 2 or more. Examples of the rubber-modified epoxy resin include those described in paragraphs

[0124] to

[0132] of WO2016-163491.

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

[0133] to

[0135] of WO2016-163491 can be used.

[0053] Examples of epoxy compounds obtainable by subjecting an epoxy resin such as a bisphenol A epoxy resin to an addition reaction with a polybasic acid include an addition reaction product of a dimer of tall oil fatty acid (dimer acid) with a bisphenol A epoxy resin, as described in WO 2010-098950.

[0054] Other monofunctional epoxy group-containing substances include, for example, aliphatic glycidyl ethers (e.g., butyl glycidyl ether, etc.); aromatic glycidyl ethers (e.g., phenyl glycidyl ether, cresyl glycidyl ether (e.g., o-cresyl glycidyl ether), etc.); ethers consisting of an alkyl group having 8 to 10 carbon atoms and a glycidyl group (e.g., 2-ethylhexyl glycidyl ether, etc.); ethers consisting of a phenyl group having 6 to 12 carbon atoms, which may be substituted with an alkyl group having 2 to 8 carbon atoms, and a glycidyl group (e.g., p-tert-butylphenyl glycidyl ether, etc.). glycidyl ether, etc.); ethers consisting of an alkyl group having 12 to 14 carbon atoms and a glycidyl group (also known as alkyl C12-C14 glycidyl ether) (for example, dodecyl glycidyl ether, etc.); aliphatic glycidyl esters (for example, glycidyl (meth)acrylate, glycidyl maleate, etc.); glycidyl esters of aliphatic carboxylic acids having 8 to 12 carbon atoms (for example, versatic acid glycidyl ester, neodecanoic acid glycidyl ester, lauric acid glycidyl ester, etc.); p-t-butylbenzoic acid glycidyl ester; and the like.

[0055] As the other epoxy group-containing substance, one of the above-mentioned substances may be used alone, or two or more of them may be used in combination.

[0056]

[0023] Component (A) preferably contains one or more epoxy group-containing substances selected from the group consisting of glycidylamine epoxy resins, biphenyl epoxy resins, oxazolidone epoxy resins, biphenyl aralkyl epoxy resins, bisnaphthalene epoxy resins, novolac epoxy resins, and glycol diglycidyl ethers; more preferably, it contains one or more epoxy group-containing substances selected from the group consisting of glycidylamine epoxy resins, biphenyl epoxy resins, oxazolidone epoxy resins, biphenyl aralkyl epoxy resins, bisnaphthalene epoxy resins, and glycol diglycidyl ethers; even more preferably, it contains one or more epoxy group-containing substances selected from the group consisting of glycidylamine epoxy resins, biphenyl epoxy resins, oxazolidone epoxy resins, and glycol diglycidyl ethers; and particularly preferably, it contains one or more epoxy group-containing substances selected from the group consisting of glycidylamine epoxy resins, biphenyl epoxy resins, and glycol diglycidyl ethers. This configuration offers the advantage that the cured product obtained by curing the composition has excellent strength, elastic modulus, and heat resistance (high Tg).

[0057] The following describes a case where component (A) contains one or more selected from the group consisting of glycidylamine-type epoxy resins, biphenyl-type epoxy resins, oxazolidone-type epoxy resins, biphenylaralkyl-type epoxy resins, bisnaphthalene-type epoxy resins, novolac-type epoxy resins, and glycol diglycidyl ethers. The total content of the glycidylamine-type epoxy resins, biphenyl-type epoxy resins, oxazolidone-type epoxy resins, biphenylaralkyl-type epoxy resins, bisnaphthalene-type epoxy resins, novolac-type epoxy resins, and glycol diglycidyl ethers in component (A) is preferably 29 parts by mass or less, more preferably 24 parts by mass or less, and particularly preferably 19 parts by mass or less. This configuration offers the advantages of a composition with a relatively low viscosity and excellent processability, and the cured product obtained by curing the composition exhibits excellent strength, elastic modulus, and heat resistance (high Tg). The lower limit of the total content of the glycidylamine-type epoxy resin, biphenyl-type epoxy resin, oxazolidone-type epoxy resin, biphenylaralkyl-type epoxy resin, bisnaphthalene-type epoxy resin, novolac-type epoxy resin, and glycol diglycidyl ether in component (A) is not particularly limited, but may be, for example, more than 0 parts by mass, 1 part by mass or more, 2 parts by mass or more, or 3 parts by mass or more. This configuration has the advantage that the cured product obtained by curing the composition has excellent strength, elastic modulus, and heat resistance (high Tg).

[0058] Component (A) may or may not further contain a glycidylamine-type epoxy resin. A description will be given of the case where component (A) contains a glycidylamine-type epoxy resin. The content of the glycidylamine-type epoxy resin in component (A) is preferably 29 parts by mass or less, more preferably 24 parts by mass or less, even more preferably 19 parts by mass or less, and particularly preferably 14 parts by mass or less. This configuration has the advantages of providing a composition with a relatively low viscosity and excellent processability, and of providing a cured product obtained by curing the composition with excellent strength, elastic modulus, and heat resistance (high Tg). The lower limit of the content of the glycidylamine-type epoxy resin in component (A) is not particularly limited, but may be, for example, more than 0 parts by mass, 1 part by mass or more, 2 parts by mass or more, or 3 parts by mass or more. This configuration has the advantages of providing a cured product obtained by curing the composition with excellent strength, elastic modulus, and heat resistance (high Tg).

[0059] In this specification, among polyfunctional epoxy group-containing substances, "polyfunctional epoxy group-containing substances having an epoxy equivalent of 300 g / eq or more and less than 3000 g / eq", that is, "polyfunctional epoxy group-containing substances having an epoxy equivalent of 300 g / eq or more and less than 3000 g / eq and having two or more epoxy groups in one molecule" may be referred to as "polyfunctional epoxy group-containing substance (a1)".

[0060] In this specification, the term "epoxy equivalent" refers to the molecular weight per epoxy group contained in an epoxy group-containing substance, and specifically, is a value calculated based on the following formula: Epoxy equivalent (g / eq) = Mass average molecular weight (Mw) of epoxy group-containing substance / Number of epoxy groups per molecule of epoxy group-containing substance (average number). The epoxy equivalent can also be measured in accordance with JIS K7236.

[0061] The component (A) may or may not contain a polyfunctional epoxy group-containing substance (a1). It is preferable that the component (A) does not contain a polyfunctional epoxy group-containing substance (a1), as this has the advantages of providing a composition with a relatively low viscosity and excellent processability.

[0062]

[0033] Component (A) preferably contains a polyfunctional epoxy group-containing substance (a1), since this has the advantage that the cured product obtained by curing the composition has excellent toughness. (i) Bisphenol A epoxy resins having an epoxy equivalent of 300 g / eq or more but less than 3000 g / eq and having two or more epoxy groups per molecule, (ii) Bisphenol F epoxy resins having an epoxy equivalent of 300 g / eq or more but less than 3000 g / eq and having two or more epoxy groups per molecule, and (iii) alicyclic epoxy resins having an epoxy equivalent of 300 g / eq or more but less than 3000 g / eq and having two or more epoxy groups per molecule are all examples of polyfunctional epoxy group-containing substances (a1). The content of the polyfunctional epoxy group-containing substance (a1) per 100 parts by mass of component (A) is preferably 5 to 100 parts by mass, more preferably 6 to 50 parts by mass, even more preferably 7 to 30 parts by mass, and particularly preferably 8 to 20 parts by mass. This configuration has the advantages of providing a composition with a relatively low viscosity and excellent processability, and further providing a cured product obtained by curing the composition with excellent toughness. The upper limit of the content of the polyfunctional epoxy group-containing substance (a1) per 100 parts by mass of component (A) may be less than 100 parts by mass.

[0063] In this specification, the "monofunctional epoxy group-containing substance" may be referred to as the "monofunctional epoxy group-containing substance (a2)." The "monofunctional epoxy group-containing substance" may also be referred to as the "monoepoxide."

[0064] The component (A) may or may not contain a monofunctional epoxy group-containing substance (a2). It is preferred that the component (A) does not contain a monofunctional epoxy group-containing substance (a2), since this has the advantage that the cured product obtained by curing the composition has excellent strength and heat resistance (high Tg).

[0065] Component (A) preferably contains a monofunctional epoxy group-containing substance (a2). This configuration has the advantages of low viscosity and excellent processability, and the cured product obtained by curing the composition has excellent toughness. The content of the monofunctional epoxy group-containing substance (a2) per 100 parts by mass of component (A) is preferably 5 to 40 parts by mass, more preferably 5 to 35 parts by mass, even more preferably 5 to 33 parts by mass, and particularly preferably 5 to 30 parts by mass. This configuration has the advantages of low viscosity and excellent processability, and the cured product obtained by curing the composition has excellent strength and / or toughness. The upper limit of the content of the monofunctional epoxy group-containing substance (a2) per 100 parts by mass of component (A) may be less than 40 parts by mass.

[0066] Since the cured product obtained by curing the composition has the advantage of being superior in toughness, it is preferable that component (A) contains a polyfunctional epoxy group-containing substance (a1) and a monofunctional epoxy group-containing substance (a2). The case where component (A) contains a polyfunctional epoxy group-containing substance (a1) and a monofunctional epoxy group-containing substance (a2) will be described below. In this case, it is preferable that, per 100 parts by mass of component (A), (i) the content of the polyfunctional epoxy group-containing substance (a1) is 5 to 95 parts by mass and the content of the monofunctional epoxy group-containing substance (a2) is 5 to 40 parts by mass; (ii) the content of the polyfunctional epoxy group-containing substance (a1) is 6 to 50 parts by mass and the content of the monofunctional epoxy group-containing substance (a2) is 5 to 35 parts by mass; (iii) the content of the polyfunctional epoxy group-containing substance (a1) is 7 to 30 parts by mass and the content of the monofunctional epoxy group-containing substance (a2) is 5 to 33 parts by mass; and (iv) the content of the polyfunctional epoxy group-containing substance (a1) is 8 to 20 parts by mass and the content of the monofunctional epoxy group-containing substance (a2) is 5 to 30 parts by mass. This configuration has the advantages that the composition has low viscosity and excellent processability, and further, the cured product obtained by curing the composition has excellent strength and / or toughness. When component (A) contains a polyfunctional epoxy group-containing substance (a1) and a monofunctional epoxy group-containing substance (a2), the content of (i) the polyfunctional epoxy group-containing substance (a1) may be less than 95 parts by mass, and / or the content of (ii) the monofunctional epoxy group-containing substance (a2) may be less than 40 parts by mass, per 100 parts by mass of component (A).

[0067] Polyalkylene glycol diglycidyl ethers, glycol diglycidyl ethers, diglycidyl esters of aliphatic polybasic acids, and glycidyl ethers of dihydric or higher polyhydric aliphatic alcohols can also be considered epoxy resins with relatively low viscosities. These "epoxy resins with relatively low viscosities" are sometimes referred to as "polyepoxides" in this specification. When polyepoxides are used in combination with epoxy resins other than polyepoxides (e.g., bisphenol A epoxy resins and / or bisphenol F epoxy resins), the polyepoxides function as reactive diluents in the composition, improving the balance between the viscosity of the composition and the physical properties of the cured product. Furthermore, when epoxy resins other than polyepoxides (e.g., bisphenol A epoxy resins and / or bisphenol F epoxy resins) are used in combination with a monofunctional epoxy group-containing substance (a2), the monofunctional epoxy group-containing substance (a2) functions as a reactive diluent in the composition, improving the balance between the viscosity of the composition and the physical properties of the cured product.

[0068] Component (A) preferably contains a monofunctional epoxy group-containing substance (a2) and / or a polyepoxide as a reactive diluent. The total amount of the monofunctional epoxy group-containing substance (a2) and the polyepoxide in component (A) is preferably 0.5 to 30.0 parts by mass, more preferably 2.0 to 20.0 parts by mass, and even more preferably 5.0 to 15.0 parts by mass, per 100 parts by mass of component (A).

[0069] The epoxy group-containing substance of component (A) may contain an epoxy group-containing substance having an epoxy equivalent of less than 220 g / eq, may consist solely of epoxy group-containing substances having an epoxy equivalent of less than 220 g / eq, may contain an epoxy group-containing substance having an epoxy equivalent of 90 g / eq or more but less than 210 g / eq, may consist solely of epoxy group-containing substances having an epoxy equivalent of 90 g / eq or more but less than 210 g / eq, or may consist solely of epoxy group-containing substances having an epoxy equivalent of 135 g / eq or more but less than 200 g / eq. This configuration has the advantage of being able to obtain a cured product with a high elastic modulus and heat resistance.

[0070] Among epoxy group-containing substances, bisphenol A epoxy resins and bisphenol F epoxy resins provide cured products with high elastic moduli, excellent heat resistance and adhesiveness, and are relatively inexpensive. Therefore, component (A) preferably contains bisphenol A epoxy resin and / or bisphenol F epoxy resin, and more preferably consists solely of bisphenol A epoxy resin and / or bisphenol F epoxy resin. Furthermore, since 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 bisphenol A epoxy resin, and particularly preferably consists solely of bisphenol A epoxy resin.

[0071] The total content of the bisphenol A epoxy resin and the bisphenol F epoxy resin per 100 parts by mass of the component (A) is preferably 60 parts by mass or more, more preferably 80 parts by mass or more, and even more preferably 90 parts by mass or more. This configuration has the advantage that the resulting cured product has excellent toughness, impact resistance, heat resistance, and strength. The total content of the bisphenol A epoxy resin and the bisphenol F epoxy resin per 100 parts by mass of the component (A) may be 100 parts by mass. In other words, the component (A) may be composed solely of (i) a bisphenol A epoxy resin, or may be composed solely of (ii) a mixture of a bisphenol A epoxy resin and a bisphenol F epoxy resin.

[0072] Both bisphenol A epoxy resins having an epoxy equivalent of less than 220 g / eq and bisphenol F epoxy resins having an epoxy equivalent of less than 220 g / eq are liquid at room temperature and have excellent handleability. Therefore, in order to obtain a composition having excellent handleability and storage stability, it is more preferable that component (A) contains a bisphenol A epoxy resin having an epoxy equivalent of less than 220 g / eq and / or a bisphenol F epoxy resin having an epoxy equivalent of less than 220 g / eq, and it is particularly preferable that component (A) contains a mixture of a bisphenol A epoxy resin having an epoxy equivalent of less than 220 g / eq and a bisphenol F epoxy resin having an epoxy equivalent of less than 220 g / eq.

[0073] In 100 parts by mass of component (A), the total content of the bisphenol A epoxy resin having an epoxy equivalent of less than 220 g / eq and the bisphenol F epoxy resin having an epoxy equivalent of less than 220 g / eq is preferably 60 parts by mass or more, more preferably 80 parts by mass or more, and even more preferably 90 parts by mass or more. This configuration has the advantages of providing a composition with even better handleability and storage stability, and of providing a cured product obtained by curing the composition with even better toughness, impact resistance, heat resistance, and strength. In 100 parts by mass of component (A), the total content of the bisphenol A epoxy resin having an epoxy equivalent of less than 220 g / eq and the bisphenol F epoxy resin having an epoxy equivalent of less than 220 g / eq may be 100 parts by mass. In other words, component (A) may be (i) composed solely of a bisphenol A epoxy resin having an epoxy equivalent of less than 220 g / eq, or (ii) composed solely of a mixture of a bisphenol A epoxy resin having an epoxy equivalent of less than 220 g / eq and a bisphenol F epoxy resin having an epoxy equivalent of less than 220 g / eq.

[0074] The content of component (A) in the composition is preferably 20 parts by mass or more, more preferably 25 parts by mass or more, even more preferably 30 parts by mass or more, and particularly preferably 35 parts by mass or more, per 100 parts by mass of the composition. This configuration has the advantage that the cured product obtained by curing the composition has excellent strength and / or toughness.

[0075] When the component (C) in the composition is acid anhydride (c1), the composition preferably contains, as component (A), (i) an alicyclic epoxy resin, more preferably (ii) a polyfunctional alicyclic epoxy resin having two or more epoxy groups per molecule, and even more preferably (iii) a polyfunctional alicyclic epoxy resin having an epoxy equivalent of less than 220 g / eq (or 90 g / eq or more and less than 220 g / eq) and having two or more epoxy groups per molecule. When the component (C) in the composition is acid anhydride (c1), the content of (i) the alicyclic epoxy resin is preferably 60 to 100 parts by mass (alternatively, 60 to less than 100 parts by mass), the content of (ii) the polyfunctional alicyclic epoxy resin having two or more epoxy groups per molecule is more preferably 60 to 100 parts by mass (alternatively, 60 to less than 100 parts by mass), and the content of (iii) the polyfunctional alicyclic epoxy resin having an epoxy equivalent of less than 220 g / eq (alternatively, 90 to less than 220 g / eq) and two or more epoxy groups per molecule is even more preferably 60 to 100 parts by mass (alternatively, 60 to less than 100 parts by mass), per 100 parts by mass of the component (A).

[0076] A preferred embodiment of the present invention has the following configuration: A curable resin composition comprising the following components (A), (B), and (C), and which does not contain the following component (D) or further contains the following component (D); component (A): an epoxy group-containing substance comprising an alicyclic epoxy resin (preferably a polyfunctional alicyclic epoxy resin having two or more epoxy groups in one molecule, more preferably a polyfunctional alicyclic epoxy resin having an epoxy equivalent of less than 220 g / eq (or 90 g / eq or more and less than 220 g / eq) and having two or more epoxy groups in one molecule); component (B): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (C): an acid anhydride (c1); component (D): a curing accelerator; and the content of the alicyclic epoxy resin in 100 parts by mass of the component (A) is 60 to 100 parts by mass (or 60 parts by mass or more and less than 100 parts by mass), the content of the (B) component is 1 part by mass to 100 parts by mass relative to 100 parts by mass of the (A) component; the content of the (C) component is 10 parts by mass to 200 parts by mass relative to 100 parts by mass of the (A) component; when the (D) component is contained, the content of the (D) component is 0.1 parts by mass to 10.0 parts by mass relative to 100 parts by mass of the (A) component; and the value X calculated by the above formula is 1.05 to 5.50.

[0077] When the component (C) in the composition is an aromatic amine (c2) or an alicyclic amine (c3), the composition preferably contains, as the component (A), (i) a bisphenol A type epoxy resin, more preferably (ii) a polyfunctional bisphenol A type epoxy resin having two or more epoxy groups per molecule, and even more preferably (iii) a polyfunctional bisphenol A type epoxy resin having an epoxy equivalent of less than 220 g / eq (or 90 g / eq or more and less than 220 g / eq) and having two or more epoxy groups per molecule. When the component (C) in the composition is an aromatic amine (c2) or an alicyclic amine (c3), the content of (i) the bisphenol A epoxy resin is preferably 60 to 100 parts by mass (or at least 60 parts by mass but less than 100 parts by mass), (ii) the content of the polyfunctional bisphenol A epoxy resin having two or more epoxy groups per molecule is more preferably 60 to 100 parts by mass (or at least 60 parts by mass but less than 100 parts by mass), and (iii) the content of the polyfunctional bisphenol A epoxy resin having an epoxy equivalent of less than 220 g / eq (or at least 90 g / eq but less than 220 g / eq) and two or more epoxy groups per molecule is even more preferably 60 to 100 parts by mass (or at least 60 parts by mass but less than 100 parts by mass), per 100 parts by mass of the component (A).

[0078] A preferred embodiment of the present invention has the following configuration: A curable resin composition comprising the following components (A), (B), and (C), and which does not contain the following component (D) or further contains the following component (D); component (A): an epoxy group-containing substance comprising a bisphenol A type epoxy resin (preferably a polyfunctional bisphenol A type epoxy resin having two or more epoxy groups in one molecule, more preferably a polyfunctional bisphenol A type epoxy resin having an epoxy equivalent of less than 220 g / eq (or 90 g / eq or more and less than 220 g / eq) and having two or more epoxy groups in one molecule); component (B): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (C): an aromatic amine (c2); component (D): a curing accelerator; and the content of the bisphenol A type epoxy resin in 100 parts by mass of the component (A) is 60 parts by mass to 100 parts by mass (or 60 parts by mass or more and less than 100 parts by mass), the content of the (B) component is 1 part by mass to 100 parts by mass relative to 100 parts by mass of the (A) component; the content of the (C) component is 10 parts by mass to 200 parts by mass relative to 100 parts by mass of the (A) component; when the (D) component is contained, the content of the (D) component is 0.1 parts by mass to 10.0 parts by mass relative to 100 parts by mass of the (A) component; and the value X calculated by the above formula is 1.30 to 9.00.

[0079] A preferred embodiment of the present invention has the following configuration: A curable resin composition comprising the following components (A), (B), and (C), and which does not contain the following component (D) or further contains the following component (D); component (A): an epoxy group-containing substance comprising a bisphenol A type epoxy resin (preferably a polyfunctional bisphenol A type epoxy resin having two or more epoxy groups in one molecule, more preferably a polyfunctional bisphenol A type epoxy resin having an epoxy equivalent of less than 220 g / eq (or 90 g / eq or more and less than 220 g / eq) and having two or more epoxy groups in one molecule); component (B): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (C): an alicyclic amine (c3); component (D): a curing accelerator; and the content of the bisphenol A type epoxy resin in 100 parts by mass of the component (A) is 60 to 100 parts by mass (or 60 parts by mass or more and less than 100 parts by mass), the content of the (B) component is 1 to 100 parts by mass relative to 100 parts by mass of the (A) component; the content of the (C) component is 5 to 200 parts by mass relative to 100 parts by mass of the (A) component; when the (D) component is contained, the content of the (D) component is 0.1 to 10.0 parts by mass relative to 100 parts by mass of the (A) component; and the value X calculated by the above formula is 1.30 to 9.00.

[0080] <1-1-3. Component (B)> The component (B) is a polymer particle having a core-shell structure comprising a core layer and a shell layer. In this specification, "polymer particles having a core-shell structure comprising a core layer and a shell layer" refers to particles in which a layer structure is formed by a core layer made of a core polymer and a shell layer made of a shell polymer. 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."

[0081] The component (B) (polymer particles) can exhibit a toughness-improving effect in the composition. In other words, by including the component (B), the composition has the advantage of being able to provide a cured product with excellent toughness. Furthermore, by including the component (B), the composition tends to provide a cured product with excellent strength.

[0082] 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.

[0083] Each layer of the polymer particles will be specifically described below.

[0084] <<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.

[0085] The core layer preferably contains a diene rubber, more preferably a diene rubber (for example, composed solely of a diene rubber), because it provides a high toughness-improving effect on the resulting cured product, a high impact resistance-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 various 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 preferably contains one or more rubbers selected from the group consisting of diene rubbers, (meth)acrylate rubbers, and organosiloxane rubbers.

[0086] (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.

[0087] 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.

[0088] These conjugated diene monomers may be used alone or in combination of two or more.

[0089] The content of the conjugated diene units in the core layer is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 100% by mass, and 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 the conjugated diene units in the core layer is 50% by mass or more, the toughness of the resulting cured product can be improved.

[0090] 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.

[0091] 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.

[0092] Among diene rubbers, the core layer preferably contains 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, from the viewpoints of a greater effect of improving the toughness of the resulting cured product, a greater effect of improving the impact resistance of the resulting cured product, and a lower affinity with the (A) epoxy resin (component (A)), making it less likely that the core layer will experience an increase in viscosity over time due to swelling. More preferably, the core layer is butadiene rubber and / or butadiene-styrene rubber (e.g., composed solely of butadiene rubber and / or butadiene-styrene rubber), even more preferably, it contains butadiene rubber, and particularly preferably, it is butadiene rubber (e.g., composed solely 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.

[0093] ((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.

[0094] 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.

[0095] 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).

[0096] 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.

[0097] Examples of vinyl monomers copolymerizable with (meth)acrylate monomers other than (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.

[0098] 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.

[0099] (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.

[0100] 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.

[0101] A case where the core layer of the polymer particles contains a diene rubber or is composed solely of a diene rubber (hereinafter also referred to as "Case A") will be described. In Case A, the diene rubber preferably contains butadiene rubber and / or butadiene-styrene rubber. This configuration has the following advantages: (i) the cured product obtained by curing the composition has excellent toughness; (ii) the cured product has excellent impact resistance; and (iii) the affinity with component (A) is low, making it less likely for the viscosity to increase over time due to swelling of the core layer. In view of these advantages, in Case A, the diene rubber preferably contains 60 parts by mass or more, more preferably 70 parts by mass or more, even more preferably 80 parts by mass or more, and particularly preferably 90 parts by mass or more of butadiene rubber, butadiene-styrene rubber, or a mixture of butadiene rubber and butadiene-styrene rubber, per 100 parts by mass of the diene rubber. In case A, the diene rubber may consist solely of butadiene rubber and / or butadiene-styrene rubber. The core layer of polymer particles may consist solely of butadiene rubber and / or butadiene-styrene rubber.

[0102] In order to enhance the toughness of the resulting cured product, the glass transition temperature of the core layer (hereinafter sometimes simply referred to as "Tg") 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. The glass transition temperature of the core layer can be measured by differential scanning calorimetry (DSC).

[0103] 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.

[0104] The core layer may have a single layer structure or a multilayer structure (e.g., a multilayer structure consisting of layers 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.

[0105] The composition of the constituent units of the core layer depends on the composition of the monomer mixture used to form the core layer (monomer mixture for forming the core layer). When the polymerization conversion rate is 100%, the obtained core layer contains constituent units derived from all of the monomers contained in the monomer mixture for forming the core layer.

[0106] 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.

[0107] <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.

[0108] The type and content ratio of the structural units 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 preferably contains one or more structural units selected from the group consisting of aromatic vinyl units, vinylcyan units, and (meth)acrylate units, and more preferably contains (meth)acrylate units. In particular, the shell layer preferably contains methyl methacrylate units.

[0109] 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.

[0110] 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).

[0111] 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.

[0112] Specific examples of the vinylcyanide monomer from which the vinylcyanide unit is derived include acrylonitrile and methacrylonitrile.

[0113] 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.

[0114] 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.

[0115] 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 acid anhydride group, a cyclic ester, a cyclic amide, a benzoxazine group, and a cyanate ester group.

[0116] 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, there is an advantage that the cured product obtained by curing the composition has excellent toughness.

[0117] 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.

[0118] When the shell layer of the polymer particle contains epoxy groups, the content of epoxy groups in the shell layer relative to the total mass of the shell layer of the polymer particle is preferably more than 0.0 mmol / g and not more than 5.0 mmol / g, more preferably 0.1 mmol / g or more and not more than 5.0 mmol / g, more preferably 0.2 mmol / g or more and not more than 5.0 mmol / g, more preferably 0.2 mmol / g or more and not more than 4.0 mmol / g, more preferably 0.2 mmol / g or more and not more than 3.0 mmol / g, even more preferably 0.2 mmol / g or more and not more than 2.0 mmol / g, and particularly preferably 0.3 mmol / g or more and not more than 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, resulting in the advantageous effect that the cured product obtained by curing the composition has excellent toughness.

[0119] 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.

[0120] 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.

[0121] Specific examples of the reactive group-containing monomer having a hydroxyl group include the above-mentioned hydroxyalkyl (meth)acrylates.

[0122] It is preferable that the shell layer contains a structural unit derived from a polyfunctional monomer having two or more radically polymerizable double bonds, since this prevents swelling of the polymer particles in the composition and tends to result in a composition with a low viscosity and easy handling. On the other hand, from the viewpoint of improving the toughness and impact resistance of the resulting cured product, it is preferable that the shell layer does not contain a structural unit derived from a polyfunctional monomer having two or more radically polymerizable double bonds.

[0123] 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.

[0124] Among these polyfunctional monomers, allyl methacrylate and triallyl isocyanurate are preferred.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] The component (B) preferably contains at least one type of polymer particle selected from the group consisting of polymer particles (B-1), polymer particles (B-2), and polymer particles (B-3) shown below: polymer particles (B-1); polymer particles having a shell layer containing epoxy groups, the content of the epoxy groups in the shell layer relative to the total mass of the shell layer being 0.2 mmol / g to 5.0 mmol / g; polymer particles (B-2); Polymer particles (B-3), in which the core layer is a diene rubber obtained by polymerizing a monomer mixture (monomer mixture for forming a core layer) containing 50.00% by mass to 99.99% by mass of (b1) a conjugated diene monomer, 0.00% by mass to 49.99% by mass of (b2) a vinyl monomer copolymerizable with the conjugated diene monomer, and 0.01% by mass to 3.00% by mass of (b3) a chain transfer agent, wherein the total of the (b1) conjugated diene monomer, (b2) the vinyl monomer copolymerizable with the conjugated diene monomer, and (b3) the chain transfer agent is 100% by mass (for example, composed solely of a diene rubber obtained by polymerizing the monomer mixture); polymer particles (B-4); a core layer comprising a diene rubber obtained by polymerizing a monomer mixture (a monomer mixture for forming a core layer) containing 50.00% by mass to 99.99% by mass of (b1) a conjugated diene monomer, 0.00% by mass to 49.99% by mass of (b2) a vinyl monomer copolymerizable with the conjugated diene monomer, and 0.01% by mass to 3.00% by mass of (b3) a chain transfer agent, wherein the total of the (b1) conjugated diene monomer, (b2) the vinyl monomer copolymerizable with the conjugated diene monomer, and (b3) the chain transfer agent is 100% by mass (for example, the core layer is composed solely of a diene rubber obtained by polymerizing the monomer mixture); and a shell layer having epoxy groups, wherein the content of the epoxy groups in the shell layer relative to the total mass of the shell layer is 0.2 mmol / g to 5.0 mmol / g.

[0129] Polymer particles (B-1) are polymer particles whose shell layer has a specific structure, polymer particles (B-2) are polymer particles whose core layer has a specific structure, and polymer particles (B-3) are polymer particles whose shell layer and core layer each have a specific structure. The specific structure of the shell layer of polymer particles (B-3) is the same as the specific structure of the shell layer of polymer particles (B-1). The specific structure of the core layer of polymer particles (B-3) is the same as the specific structure of the core layer of polymer particles (B-2). In this specification, polymer particles that fall under the category of polymer particles (B-3) are excluded from the scope of both polymer particles (B-1) and polymer particles (B-2), and are considered to not fall under either polymer particles (B-1) or polymer particles (B-2).

[0130] When the component (B) contains at least one type of polymer particles selected from the group consisting of polymer particles (B-1), polymer particles (B-2), and polymer particles (B-3), the cured product obtained by curing the composition has the advantage of having excellent toughness.

[0131] The core layer of the polymer particles (B-1) preferably contains one or more rubbers selected from the group consisting of diene rubbers, (meth)acrylate rubbers, and organosiloxane rubbers, more preferably one or more rubbers selected from the group consisting of diene rubbers and (meth)acrylate rubbers, and even more preferably a diene rubber. This configuration has the advantage that the cured product obtained by curing the composition has excellent toughness.

[0132] The core layer of the polymer particles (B-1) preferably contains 60 parts by mass or more, more preferably 70 parts by mass or more, even more preferably 80 parts by mass or more, and particularly preferably 90 parts by mass or more, of one or more rubbers selected from the group consisting of diene rubbers, (meth)acrylate rubbers, and organosiloxane rubbers, per 100 parts by mass of the core layer. This configuration has the advantage that the cured product obtained by curing the composition has even better toughness. The core layer of the polymer particles (B-1) may be one or more rubbers selected from the group consisting of diene rubbers, (meth)acrylate rubbers, and organosiloxane rubbers, or may be composed solely of one or more rubbers selected from this group.

[0133] In the polymer particles (B-2) and (B-3), the monomer mixture used to form the core layer (monomer mixture for forming the core layer) contains a chain transfer agent. The core layer obtained by polymerizing the monomer mixture for forming the core layer containing the chain transfer agent has the advantage that the cured product obtained by curing the composition has excellent toughness.

[0134] The chain transfer agent is not particularly limited, and known chain transfer agents can be used. Specific examples of the chain transfer agent include t-dodecyl mercaptan, n-dodecyl mercaptan, normal octyl mercaptan, and 2-ethylhexyl thioglycolate.

[0135] In the polymer particles (B-2) and (B-3), the amount of the chain transfer agent in the core layer-forming monomer mixture is preferably 0.01% by mass to 3.00% by mass, more preferably 0.10% by mass to 2.00% by mass, even more preferably 0.20% by mass to 1.00% by mass, still more preferably 0.25% by mass to 0.70% by mass, and particularly preferably 0.30% by mass to 0.50% by mass, relative to 100% by mass of the core layer-forming monomer mixture. This configuration has the advantage that the cured product obtained by curing the composition has excellent toughness.

[0136] The diene rubber obtained by polymerizing a monomer mixture containing (b1) a conjugated diene monomer, (b2) a vinyl monomer copolymerizable with the conjugated diene monomer, and (b3) a chain transfer agent contains structural units derived from the conjugated diene monomer, structural units derived from the vinyl monomer copolymerizable with the conjugated diene monomer, and structural units derived from decomposition products of the chain transfer agent, in other words, structural units derived from the chain transfer agent. When the polymerization conversion rate is 100%, the contents of the structural units derived from the conjugated diene monomer, the structural units derived from the vinyl monomer copolymerizable with the conjugated diene monomer, and the structural units derived from the chain transfer agent in the diene rubber obtained by polymerizing a monomer mixture containing (b1) a conjugated diene monomer, (b2) a vinyl monomer copolymerizable with the conjugated diene monomer, and (b3) a chain transfer agent can be considered to be the same as the contents of the (b1) conjugated diene monomer, (b2) the vinyl monomer copolymerizable with the conjugated diene monomer, and (b3) the chain transfer agent contained in the monomer mixture, respectively. Therefore, it can also be said that the core layer in the polymer particles (B-2) and the polymer particles (B-3) is a diene rubber containing 50.00% by mass to 99.99% by mass of (b1') structural units derived from a conjugated diene monomer, 0.00% by mass to 49.99% by mass of (b2') structural units derived from a vinyl monomer copolymerizable with the conjugated diene monomer, and 0.01% by mass to 3.00% by mass of (b3) structural units derived from a chain transfer agent.

[0137] The content of polymer particles (B-1) in component (B) is not particularly limited. The content of polymer particles (B-1) in component (B) is preferably 60 parts by mass or more, more preferably 70 parts by mass or more, more preferably 80 parts by mass or more, even more preferably 90 parts by mass or more, and particularly preferably 95 parts by mass or more, per 100 parts by mass of component (B). The content of polymer particles (B-1) in component (B) may be 100 parts by mass per 100 parts by mass of component (B). In other words, component (B) may be composed solely of polymer particles (B-1).

[0138] The content of polymer particles (B-2) in component (B) is not particularly limited. The content of polymer particles (B-2) in component (B) is preferably 60 parts by mass or more, more preferably 70 parts by mass or more, more preferably 80 parts by mass or more, even more preferably 90 parts by mass or more, and particularly preferably 95 parts by mass or more, per 100 parts by mass of component (B). The content of polymer particles (B-2) in component (B) may be 100 parts by mass per 100 parts by mass of component (B). In other words, component (B) may be composed solely of polymer particles (B-2).

[0139] The content of polymer particles (B-3) in component (B) is not particularly limited. The content of polymer particles (B-3) in component (B) is preferably 60 parts by mass or more, more preferably 70 parts by mass or more, more preferably 80 parts by mass or more, even more preferably 90 parts by mass or more, and particularly preferably 95 parts by mass or more, per 100 parts by mass of component (B). The content of polymer particles (B-3) in component (B) may be 100 parts by mass per 100 parts by mass of component (B). In other words, component (B) may be composed solely of polymer particles (B-3).

[0140] <<Volume average particle diameter (Mv) of polymer particles>> The volume average particle diameter (Mv) of the polymer particles is not particularly limited. From the viewpoint of industrial productivity and workability of the curable resin composition, the volume average particle diameter (Mv) of the polymer particles is preferably 0.01 μm or more and 2.00 μm or less, more preferably 0.03 μm or more and 0.60 μm or less, more preferably 0.05 μm or more and 0.40 μm or less, more preferably 0.10 μm or more and 0.30 μm or less, more preferably 0.15 μm or more and 0.30 μm or less, more preferably 0.16 μm or more and 0.28 μm or less, more preferably 0.17 μm or more and 0.27 μm or less, and even more preferably 0.18 μm or more and 0.25 μm or less. When the volume average particle diameter (Mv) of the polymer particles is (a) 0.01 μm or more, the viscosity of the composition is low, resulting in good workability, and when it is (b) 2.00 μm or less, the polymerization time of the polymer particles is short, resulting in high industrial productivity. The method for measuring the volume average particle diameter (Mv) of the polymer particles will be described in detail in the Examples below.

[0141] In the composition, the polymer particles of component (B) are preferably dispersed in the state of primary particles. In this specification, "polymer particles dispersed in the state of primary particles" (hereinafter also referred to as "primary dispersion") means that the polymer particles are dispersed substantially independently (without adhering (cohesion)). The dispersion state of the polymer particles in the composition can be confirmed, for example, by dissolving a part of the composition in a solvent such as methyl ethyl ketone, subjecting the obtained solution to a particle size measurement device using laser light scattering, or the like, and measuring the particle size of the polymer particles in the solution.

[0142] 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.

[0143] The polymer particles may be used alone or in combination of two or more kinds.

[0144] <<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.

[0145] (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.

[0146] 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.

[0147] In emulsion polymerization, an emulsifier (dispersant) is used.

[0148] 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.

[0149] These emulsifiers (dispersants) may be used alone or in combination of two or more.

[0150] 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.

[0151] When emulsion polymerization is employed, peroxides (for example, organic peroxides), chain transfer agents, surfactants, and the like may be used as needed.

[0152] The polymerization conditions such as polymerization temperature, pressure, deoxidation, etc., may be within known ranges.

[0153] The composition preferably contains at least polymer particles as component (B), since the cured product obtained by curing the composition has an excellent balance between the toughness improving effect and impact resistance.

[0154] The content of component (B) in the composition is 1 to 100 parts by mass, preferably 3 to 90 parts by mass, more preferably 5 to 80 parts by mass, even more preferably 10 to 75 parts by mass, and particularly preferably 15 to 70 parts by mass, per 100 parts by mass of component (A). This configuration has the advantage that the cured product obtained by curing the composition has an excellent balance between the toughness improving effect and impact resistance.

[0155] <1-1-4. Component (C)> The component (C) is an acid anhydride (c1), an aromatic amine (c2), or an alicyclic amine (c3). In the composition, the component (C) can function as a curing agent. In other words, the composition contains an acid anhydride (c1), an aromatic amine (c2), or an alicyclic amine (c3) as a curing agent.

[0156] <Acid Anhydride (c1)> The case where component (C) is acid anhydride (c1) (hereinafter also referred to as Case B) will be described. In Case B, the viscosity of the resulting composition can be low and the pot life can be long. As a result, Case B has the advantage of the composition having excellent processability. Case B also has the advantages that the composition can be cured at relatively low temperatures by adding a curing accelerator, that the resulting cured product has a relatively good balance in terms of electrical properties, chemical properties, and mechanical properties, and that the amount of heat generated during curing is low, making it easy to produce large molded products.

[0157] When the component (C) is an acid anhydride (c1), the component (C) preferably does not contain an aromatic amine (c2) or an alicyclic amine (c3), and more preferably consists of only the acid anhydride (c1).

[0158] The acid anhydride (c1) is not particularly limited. Examples of the acid anhydride (c1) include the following substituted or unsubstituted compounds: 4-methylcyclohexane-1,2-dicarboxylic anhydride, polysebacic acid polyanhydride, polyazelaic acid polyanhydride, succinic anhydride, citraconic anhydride, itaconic anhydride, alkenyl-substituted succinic anhydride, octenylsuccinic anhydride, dodecenylsuccinic anhydride, maleic anhydride, tricarballylic anhydride, nadic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, and linoleic acid produced by maleic anhydride. adducts, alkylated terminated alkylene tetrahydrophthalic anhydride, methyl tetrahydrophthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, trialkyl tetrahydrophthalic anhydride, pyromellitic dianhydride, trimellitic anhydride, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, dichloromaleic anhydride, chloronadic anhydride, chlorendic anhydride, and maleic anhydride-grafted polybutadiene.

[0159] The acid anhydride (c1) (i) preferably contains one or more selected from the group consisting of substituted or unsubstituted methyl nadic anhydride, substituted or unsubstituted hydrogenated methyl nadic anhydride, substituted or unsubstituted methyl tetrahydrophthalic anhydride, and substituted or unsubstituted methyl hexahydrophthalic anhydride, or is composed of only one or more selected from the group, and (ii) more preferably contains one or more selected from the group consisting of substituted or unsubstituted methyl nadic anhydride, substituted or unsubstituted methyl tetrahydrophthalic anhydride, and substituted or unsubstituted methyl hexahydrophthalic anhydride. (iii) More preferably, the composition contains one or more selected from the group consisting of substituted or unsubstituted methyltetrahydrophthalic anhydride and substituted or unsubstituted methylhexahydrophthalic anhydride, or is composed of only one or more selected from the group consisting of substituted or unsubstituted methyltetrahydrophthalic anhydride; (iv) Particularly preferably, the composition contains substituted or unsubstituted methyltetrahydrophthalic anhydride, or is composed of only substituted or unsubstituted methyltetrahydrophthalic anhydride. This configuration reduces the viscosity of the resulting composition, improving fiber impregnation. This results in the advantageous effect of obtaining a cured product with superior toughness. The substituent is not particularly limited, and examples include hydrocarbon groups and alkoxy groups.

[0160] Furthermore, the acid anhydride (c1) preferably contains 4-methylcyclohexane-1,2-dicarboxylic anhydride or consists solely of 4-methylcyclohexane-1,2-dicarboxylic anhydride, since this has the advantage that the viscosity of the resulting composition is particularly low and the cured product obtained by curing the composition has excellent heat resistance.

[0161] <<Aromatic Amine (c2)>> When the component (C) is an aromatic amine (c2), the cured product obtained by curing the composition has the advantages of excellent heat resistance and high strength and / or toughness.

[0162] When the component (C) is an aromatic amine (c2), the component (C) preferably does not contain an acid anhydride (c1) or an alicyclic amine (c3), and more preferably consists of only an aromatic amine (c2).

[0163] The aromatic amine (c2) is not particularly limited, and examples of the aromatic amine (c2) include 3,3'-dichloro-4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, trimethylene-bis(4-aminobenzoate), 2,4-diamino-3,5-diethyltoluene, 2,6-diamino-3,5-diethyltoluene, dimethylthiotoluenediamine, diaminodiphenylmethane, diethyltoluenediamine, 4,4'-methylenebis[N-(1-methylpropyl)aniline], 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenyl ether, 1,3-bis(3-aminophenoxy)benzene, aminobenzylamine, and metaphenylenediamine.

[0164] The aromatic amine (c2) (i) preferably comprises one or more selected from the group consisting of diethyltoluenediamine, metaphenylenediamine, diaminodiphenylmethane, 2,4-diamino-3,5-diethyltoluene, 2,6-diamino-3,5-diethyltoluene, 3,3'-diaminodiphenylsulfone, and 4,4'-diaminodiphenylsulfone, or consists of only one or more selected from the group, and (ii) more preferably comprises one or more selected from the group consisting of diethyltoluenediamine, metaphenylenediamine, diaminodiphenylmethane, 3,3' (iii) more preferably, the composition contains one or more selected from the group consisting of diethyltoluenediamine, diaminodiphenylmethane, and 4,4'-diaminodiphenylsulfone, or is composed solely of one or more selected from said group; (iv) particularly preferably, the composition contains diethyltoluenediamine, or is composed solely of diethyltoluenediamine. This configuration has the advantages of a relatively low viscosity of the composition, excellent processability of the composition, and excellent toughness of the cured product obtained by curing the composition.

[0165] <<Alicyclic Amine (c3)>> This section describes the case where an alicyclic amine (c3) is used as the curing agent, in other words, the case where the component (C) is an alicyclic amine (c3). In this case, the curing rate of the composition is increased, and curing can proceed even at relatively low temperatures and / or curing can be completed in a relatively short time. Therefore, when the component (C) is an alicyclic amine (c3), the molding cycle of the cured product is short, which is advantageous in terms of excellent productivity. The alicyclic amine (c3) is a curing agent with a fast curing rate. On the other hand, the cured product obtained by curing a composition containing an alicyclic amine (c3) as the component (C) also has the advantage of being relatively heat-resistant and having high strength and / or toughness.

[0166] When the component (C) is an alicyclic amine (c3), the component (C) preferably does not contain an acid anhydride (c1) or an aromatic amine (c2), and more preferably consists of only the alicyclic amine (c3).

[0167] The alicyclic amine (c3) is not particularly limited, and examples of the alicyclic amine (c3) include isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), aminoethylpiperazine, piperazine, and menthenediamine.

[0168] The alicyclic amine (c3) preferably contains one or more selected from the group consisting of isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), aminoethylpiperazine, piperazine, and menthenediamine, and more preferably consists of one or more selected from the group consisting of isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), and aminoethylpiperazine. (iii) more preferably, the composition contains one or more selected from the group consisting of isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, and 4,4'-methylenebis(cyclohexylamine), and more preferably, the composition contains one or more selected from the group consisting of isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, and 4,4'-methylenebis(cyclohexylamine), and more preferably, the composition contains one or more selected from the group consisting of isophoronediamine and 4,4'-methylenebis(cyclohexylamine), and particularly preferably, the composition contains one or more selected from the group consisting of isophoronediamine and 4,4'-methylenebis(cyclohexylamine). This composition has the following advantages: (i) the composition has a low viscosity and is therefore easy to process; (ii) the composition has a high curing rate and is therefore easy to produce a cured product; and (iii) the cured product obtained by curing the composition has excellent toughness.

[0169] The content of component (C) in the composition is 5 to 200 parts by mass, preferably 10 to 200 parts by mass, preferably 11 to 170 parts by mass, more preferably 12 to 150 parts by mass, even more preferably 13 to 130 parts by mass, and particularly preferably 15 to 115 parts by mass, per 100 parts by mass of component (A). This configuration has the advantage that the cured product obtained by curing the composition has excellent strength and toughness.

[0170] The case where the component (C) is an acid anhydride (c1) will be described below. In this case, the content of the component (C) in the composition is preferably 40 to 200 parts by mass, more preferably 50 to 170 parts by mass, more preferably 55 to 150 parts by mass, even more preferably 60 to 130 parts by mass, and particularly preferably 65 to 115 parts by mass, per 100 parts by mass of the component (A). This configuration has the advantage that the cured product obtained by curing the composition has excellent strength and toughness.

[0171] The case where the component (C) is an acid anhydride (c1) will be described below. In this case, the content of the component (C) in the composition is preferably set appropriately relative to the molar amount of epoxy groups in the component (A) contained in the composition. In other words, when the component (C) is an acid anhydride (c1), the ratio of the molar amount of acid anhydride groups in the component (C) to the molar amount of epoxy groups in the component (A) contained in the composition (molar amount of acid anhydride groups in the component (C) / molar amount of epoxy groups in the component (A)) is preferably within a specific range. When the component (C) is an acid anhydride (c1), the ratio (molar amount of acid anhydride groups in the component (C) / molar amount of epoxy groups in the component (A)) is preferably 0.35 to 0.87, more preferably 0.40 to 0.87, even more preferably 0.45 to 0.87, and particularly preferably 0.50 to 0.87. When the component (C) is an acid anhydride (c1) and the ratio (molar amount of acid anhydride groups in the component (C) / molar amount of epoxy groups in the component (A)) is 0.87 or less, the composition has an advantage that the value X tends to be 1.05 to 5.50. As a result, the resulting composition has an advantage that it can provide a cured product with excellent toughness. When the component (C) is an acid anhydride (c1) and the ratio (molar amount of acid anhydride groups in the component (C) / molar amount of epoxy groups in the component (A)) is 0.35 or more, the composition has an advantage that it can provide a cured product with excellent heat resistance, i.e., a cured product with a high Tg.

[0172] The case where component (C) is an aromatic amine (c2) will be described below. In this case, the content of component (C) in the composition is 10 to 70 parts by mass, preferably 11 to 60 parts by mass, more preferably 12 to 50 parts by mass, even more preferably 13 to 45 parts by mass, and particularly preferably 15 to 40 parts by mass, per 100 parts by mass of component (A). This configuration has the advantage that the cured product obtained by curing the composition has excellent strength and toughness.

[0173] The case where component (C) is an aromatic amine (c2) will be described below. In this case, the content of component (C) in the composition is preferably set appropriately relative to the molar amount of epoxy groups in component (A) contained in the composition. In other words, when component (C) is aromatic amine (c2), the ratio of the molar amount of active hydrogen of the amine in component (C) to the molar amount of epoxy groups in component (A) contained in the composition (molar amount of active hydrogen of the amine in component (C) / molar amount of epoxy groups in component (A)) is preferably within a specific range. When component (C) is aromatic amine (c2), the ratio (molar amount of active hydrogen of the amine in component (C) / molar amount of epoxy groups in component (A)) is preferably 0.67 to 0.87, more preferably 0.67 to 0.85, even more preferably 0.67 to 0.83, and particularly preferably 0.68 to 0.82. Alternatively, when component (C) is an aromatic amine (c2), the ratio (molar amount of active hydrogen in the amine in component (C) / molar amount of epoxy groups in component (A)) is preferably 1.10 to 2.40, more preferably 1.25 to 2.30, more preferably 1.45 to 2.20, even more preferably 1.55 to 2.15, and particularly preferably 1.85 to 2.10. This configuration has the advantage that the value X of the composition is highly likely to be 1.30 to 9.00. As a result, the resulting composition has the advantage of being able to provide a cured product with excellent toughness. Furthermore, this configuration has the advantage that the composition can provide a cured product with excellent heat resistance, i.e., a cured product with a high Tg.

[0174] The case where component (C) is an alicyclic amine (c3) will be described below. In this case, the content of component (C) in the composition is preferably 5 to 200 parts by mass, more preferably 5 to 70 parts by mass, more preferably 7 to 60 parts by mass, more preferably 9 to 50 parts by mass, more preferably 11 to 45 parts by mass, even more preferably 13 to 40 parts by mass, and particularly preferably 15 to 35 parts by mass, per 100 parts by mass of component (A). This configuration has the advantage that the cured product obtained by curing the composition has excellent strength and toughness.

[0175] The case where component (C) is an alicyclic amine (c3) will be described below. In this case, the content of component (C) in the composition is preferably set appropriately relative to the molar amount of epoxy groups in component (A) contained in the composition. In other words, when component (C) is alicyclic amine (c3), the ratio of the molar amount of active hydrogen of the amine in component (C) to the molar amount of epoxy groups in component (A) contained in the composition (molar amount of active hydrogen of the amine in component (C) / molar amount of epoxy groups in component (A)) is preferably within a specific range. When component (C) is alicyclic amine (c3), the ratio (molar amount of active hydrogen of the amine in component (C) / molar amount of epoxy groups in component (A)) is preferably 0.67 to 0.87, more preferably 0.67 to 0.85, even more preferably 0.67 to 0.83, and particularly preferably 0.68 to 0.82. Alternatively, when component (C) is an alicyclic amine (c3), the ratio (molar amount of active hydrogen in the amine in component (C) / molar amount of epoxy groups in component (A)) is preferably 1.10 to 2.40, more preferably 1.25 to 2.30, more preferably 1.45 to 2.20, even more preferably 1.55 to 2.15, and particularly preferably 1.85 to 2.10. This configuration has the advantage that the value X of the composition is highly likely to be 1.30 to 9.00. As a result, the resulting composition has the advantage of being able to provide a cured product with excellent toughness. Furthermore, this configuration has the advantage that the composition can provide a cured product with excellent heat resistance, i.e., a cured product with a high Tg.

[0176] <1-1-5. Component (D)> Component (D) is a curing accelerator. As used herein, the term "curing accelerator" refers to a substance that can accelerate the curing of a composition. The curing accelerator can function as a catalyst to accelerate, for example, the reaction between epoxy groups contained in component (A) or the reaction between epoxy groups contained in component (A) and epoxy groups contained in component (C) or other components.

[0177] The component (D) is not particularly limited. Examples of the component (D) include (a) ureas such as 3-(3,4-dichlorophenyl)-1,1-dimethylurea, p-chlorophenyl-N,N-dimethylurea (trade name: Monuron), 3-phenyl-1,1-dimethylurea (trade name: Fenuron), 3,4-dichlorophenyl-N,N-dimethylurea (trade name: Diuron), N-(3-chloro-4-methylphenyl)-N',N'-dimethylurea (trade name: Chlortoluron), and 1,1-dimethylphenylurea (trade name: Dyhard); (b) benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 2-(dimethylaminomethyl)phenol, and 2,4,6 tris(dimethylaminomethyl)phenol incorporated into a poly(p-vinylphenol) matrix; (c) tertiary amines such as alkylene imidazoles having 1 to 12 carbon atoms (C1-C12), N-arylimidazole, 2-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, N-butylimidazole, 2-undecylimidazole, 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, and addition products of epoxy resins and imidazoles; (d) Lewis acid amine complexes such as boron trifluoride amine complex and boron trichloride amine complex; and (e) 6-caprolactam. Component (D) may be encapsulated in microcapsules or the like, or may be a substance capable of functioning as a latent catalyst that becomes active only when the temperature is elevated. A latent curing accelerator in which imidazoles or tertiary amines are microencapsulated can also be used as component (D). Commercially available latent curing accelerators (e.g., Novacure HX-3722, Novacure HX-3742, Novacure HX-3088, etc., manufactured by Asahi Kasei Corporation) can also be used. As component (D), one of these may be used alone, or two or more may be used in combination.

[0178] Among the above, the component (D) preferably contains one or more selected from the group consisting of (i) (b) tertiary amines such as 2,4,6-tris(dimethylaminomethyl)phenol, triethylenediamine, and N,N-dimethylpiperazine, and (c) imidazoles such as 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, and 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole, and more preferably consists of only one or more selected from this group; and further preferably contains one or more selected from the group consisting of (ii) 2,4,6-tris(dimethylaminomethyl)phenol and 2-ethyl-4-methylimidazole, and particularly preferably consists of only one or more selected from this group.

[0179] When the component (C) is an acid anhydride (c1), the composition preferably contains a component (D). When the component (C) is an aromatic amine (c2) or an alicyclic amine (c3), the composition may or may not contain a component (D).

[0180] When the composition contains component (D), the content of component (D) in the composition is 0.1 to 20.0 parts by mass, preferably 0.2 to 16.0 parts by mass, more preferably 0.5 to 13.0 parts by mass, even more preferably 1.0 to 10.0 parts by mass, and particularly preferably 2.0 to 8.0 parts by mass, per 100 parts by mass of component (A). This configuration has the advantage of being able to sufficiently accelerate curing of the composition.

[0181] <1-1-6. Other Components> The composition may contain other components as necessary. Examples of such other components include, but are not limited to, reinforcing agents such as epoxy unmodified rubber polymers, inorganic fillers such as silicic acid and / or silicates, calcium oxide, radical curing resins, photopolymerization initiators, expanding agents such as azo-type chemical foaming agents and / or thermally expandable microballoons, colorants such as pigments and / or dyes, extender pigments, ultraviolet absorbers, antioxidants, stabilizers (antigelling agents), plasticizers, leveling agents, antifoaming agents, silane coupling agents, antistatic agents, flame retardants, lubricants, viscosity reducers, low-shrinkage agents, organic fillers, thermoplastic resins, desiccants, and dispersants.

[0182] <1-1-7. Value X> The value X of the composition varies depending on the component (C). When the component (C) is an acid anhydride (c1), the value X is 1.05 to 5.50. This configuration enables the composition to provide a cured product with excellent toughness. When the component (C) is an acid anhydride (c1), the value X is preferably 1.05 to 5.00, more preferably 1.05 to 4.50, even more preferably 1.06 to 4.25, and particularly preferably 1.07 to 4.00, since this provides a cured product with even better toughness.

[0183] When component (C) is an aromatic amine (c2) or an alicyclic amine (c3), the value X is 1.30 to 9.00. This configuration enables the composition to provide a cured product with excellent toughness. When component (C) is an aromatic amine (c2) or an alicyclic amine (c3), the value X is preferably 1.35 to 8.75, more preferably 1.40 to 8.50, even more preferably 1.45 to 8.25, and particularly preferably 1.50 to 8.00, since this results in a cured product with even better toughness.

[0184] The value X of the composition is (i) the ratio of the molar amount of acid anhydride groups in the component (C) to the molar amount of epoxy groups in the component (A) contained in the composition (molar amount of acid anhydride groups in the component (C) / molar amount of epoxy groups in the component (A)), (ii) the ratio of the molar amount of active hydrogen of the amine in the component (C) to the molar amount of epoxy groups in the component (A) contained in the composition (molar amount of active hydrogen of the amine in the component (C) / molar amount of epoxy groups in the component (A)), (iii) the average epoxy equivalent of the epoxy group-containing substance (A) contained in the composition, (iv) the average acid anhydride equivalent of the acid anhydride (c1) contained in the composition, the average active hydrogen equivalent of the amine of the aromatic amine (c2) contained in the composition, or the average active hydrogen equivalent of the amine of the alicyclic amine (c3) contained in the composition, (v) the average epoxy equivalent of the amine in the composition, (vi) the average epoxy equivalent of the amine in the composition, (vii) the average epoxy equivalent of the amine in the composition, (viii) the average epoxy equivalent of the amine in the composition, (viiii ... (vi) the amount of the monofunctional epoxy group-containing substance (a2) contained in the composition and having one epoxy group per molecule; (vii) the average number of epoxy groups per molecule of the epoxy group-containing substance (A) contained in the composition; (viii) the average number of acid anhydride groups per molecule of the acid anhydride (c1) contained in the composition; the average number of active hydrogen atoms per molecule of the amine in the aromatic amine (c2) contained in the composition; or the average number of active hydrogen atoms per molecule of the amine in the alicyclic amine (c3) contained in the composition; and (ix) the type and amount of the curing accelerator (D) contained in the composition.

[0185] In calculating the value X, the curing conditions (e.g., curing temperature, curing time, thickness of the composition before curing, etc.) of the composition (M) when curing the composition (M) to obtain the cured product (M) are the same as the curing conditions of the composition (M) when curing the composition (M) to obtain the cured product (M).

[0186] <1-1-8. Value Y> The value Y of the composition can reflect the molecular weight between crosslink points of the composition. The value Y of the composition is preferably 22 to 400, more preferably 25 to 360, more preferably 30 to 320, even more preferably 35 to 280, and particularly preferably 40 to 200. The larger the value Y, the more advantageously the cured product obtained will have excellent elongation properties. The smaller the value Y, the more advantageously the cured product obtained will have excellent strength and heat resistance.

[0187] The value Y of the composition is (i) the average epoxy equivalent of the epoxy group-containing substance (A) contained in the composition, (ii) the average acid anhydride equivalent of the acid anhydride (c1) contained in the composition, the average active hydrogen equivalent of the amine of the aromatic amine (c2) contained in the composition, or the average active hydrogen equivalent of the amine of the alicyclic amine (c3) contained in the composition, (iii) the amount of the polyfunctional epoxy group-containing substance (a1) contained in the composition, which has an epoxy equivalent of 300 g / eq or more and less than 3000 g / eq and has two or more epoxy groups in one molecule, (iv) the amount of the monofunctional epoxy group-containing substance (a2) contained in the composition and has one epoxy group in one molecule, and (v) the amount of the polyfunctional epoxy group-containing substance (a3) ​​contained in the composition. (vi) the average number of epoxy groups per molecule of the epoxy group-containing substance (A) contained in the composition, (vii) the average number of acid anhydride groups per molecule of the acid anhydride (c1) contained in the composition, the average number of active hydrogen atoms per molecule of the amine of the aromatic amine (c2) contained in the composition, or the average number of active hydrogen atoms per molecule of the amine of the alicyclic amine (c3) contained in the composition, (vii) the type and amount of the curing accelerator (D) contained in the composition, and (viii) the amount of the acid anhydride (c1) contained in the composition, the amount of the aromatic amine (c2) contained in the composition, or the amount of the alicyclic amine (c3) contained in the composition, etc.

[0188] <1-1-9. Viscosity of Curable Resin Composition> In order to achieve excellent fiber impregnation, the composition preferably has a viscosity of 5000 mPa·s or less, more preferably 4000 mPa·s or less, more preferably 3000 mPa·s or less, more preferably 2500 mPa·s or less, more preferably 2000 mPa·s or less, even more preferably 1000 mPa·s or less, and particularly preferably 800 mPa·s or less at 25°C. Similarly, in order to achieve excellent fiber impregnation, the composition preferably has a viscosity of 1000 mPa·s or less, more preferably 800 mPa·s or less, more preferably 500 mPa·s or less, even more preferably 300 mPa·s or less, and particularly preferably 200 mPa·s or less at 50°C.

[0189] The composition can also be used after being heated to a temperature of, for example, 40°C to 100°C, preferably 40°C to 90°C, and more preferably 50°C to 80°C, within a range that balances a sufficient viscosity reduction (preferably 200 mPa s or less) and a sufficient working time until curing.

[0190] [1-2. Curable resin composition satisfying at least the above-mentioned (2)] In this section, a curable resin composition satisfying at least the above-mentioned (2) will be described below.

[0191] <1-2-1. Technical Concept Related to Curable Resin Compositions Satisfying at Least Requirement (2)> Conventionally known curable resin compositions have room for further improvement in terms of toughness. Therefore, the present inventors conducted extensive research with the aim of providing a novel curable resin composition that can provide a cured product having excellent toughness.

[0192] In a curable resin composition containing an epoxy group-containing substance (e.g., an epoxy resin), the greater the number of epoxy groups contained in one molecule of the epoxy group-containing substance, the higher the crosslink density of the cured product. Furthermore, when comparing substances containing the same number of epoxy groups per molecule of the epoxy group-containing substance, the smaller the molecular weight of the epoxy group-containing substance, the higher the crosslink density of the cured product, and the greater the molecular weight of the epoxy group-containing substance, the lower the crosslink density of the cured product. The higher the crosslink density of the cured product, the smaller the molecular weight between crosslink points of the cured product. For example, a curable resin composition containing a large amount of a polyfunctional epoxy group-containing substance as the epoxy group-containing substance has a high crosslink density of the cured product, or in other words, a low molecular weight between crosslink points of the cured product.

[0193] As a result of extensive research, the present inventors have independently and surprisingly obtained the novel finding that by adjusting the molecular weight between crosslink points of the cured product to a value within a specific range and by using polymer particles, the toughness of the cured product can be improved.

[0194] The molecular weight between crosslinks of a cured product can be calculated from the theory of rubber elasticity of crosslinked rubber, for example, using the following formula: Molecular weight between crosslinks = 2 x (1 + μ) x ρ x R x T / E = ρ x R x T / G In the formula, μ represents the Poisson's ratio of the cured product, ρ represents the specific gravity of the cured product, R represents the gas constant, T represents absolute temperature (K), and E and G represent the Young's modulus and rigidity modulus in the rubber-like region of the cured product. The rubber-like region is a region observed on the higher temperature side than the transition region near the glass transition temperature when measuring the temperature dependence of the elastic modulus (Young's modulus, rigidity modulus, etc.), and represents a region in which the temperature dependence of the elastic modulus is flat. Since crosslinked polymers such as epoxy resin cured products do not have a flow region on the higher temperature side than the rubber-like region, E and G in the formula can be expressed as the minimum values ​​of the Young's modulus and rigidity modulus in the rubber-like region. Furthermore, since the Young's modulus in the rubber-like region is roughly equal to the storage modulus determined by dynamic viscoelasticity measurement, which is easy to measure, the molecular weight between crosslinks can be calculated by the following formula: Molecular weight between crosslinks = 2 × (1 + μ) × ρ × R × (273 + Tmin) / E'min In the formula, μ represents the Poisson's ratio of the cured product, ρ represents the specific gravity of the cured product, R represents the gas constant, E'min represents the minimum value of the storage modulus of the cured product, and Tmin represents the temperature (°C) at which the storage modulus of the cured product reaches its minimum value.

[0195] The molecular weight between crosslinks of the cured product (α) obtained by curing the curable resin composition (α) containing an epoxy group-containing substance (component (A)), polymer particles (component (B)), a curing agent (component (C)), and a curing accelerator (component (D)) can be represented by the following formula: Molecular weight between crosslinks of cured product (α)={2×[1+μ(cured product (α))]×ρ(cured product (α))×R×[273+Tmin(cured product (α))] / E'min(cured product (α))}.

[0196] Here, the Poisson's ratio (μ) and specific gravity (ρ) of the cured product depend on the type of resin component of the curable resin composition, i.e., component (A). However, as long as component (A) is an epoxy group-containing substance, they are hardly affected by the type and amount of the epoxy group-containing substance. Therefore, in a cured product of an epoxy group-containing substance, the Poisson's ratio (μ) and specific gravity (ρ) of the cured product can be regarded as "constants." Furthermore, R is a constant (gas constant). Therefore, when only the variable portion of the molecular weight between crosslink points of the cured product (α) is expressed by a formula, it is as follows: Variable portion of the molecular weight between crosslink points of the cured product (α) = [273 + Tmin (M)] / [E' (M)] In this specification, the above-mentioned "variable portion of the molecular weight between crosslink points of the cured product (α)" is referred to as "value Y." That is, as a result of extensive research, the present inventor independently discovered the novel finding that, surprisingly, by setting the value Y within a predetermined range and using polymer particles, the toughness of the cured product can be improved, and this finding led to the completion of the present invention.

[0197] The evaluation of the inter-crosslink molecular weight must be based on measurements of a cured product obtained by curing a composition containing only components (A), (C), and (D). This is because components (A) and (C) form a crosslinked structure, and component (D) can affect the degree of progress of the crosslinking reaction. Conversely, when evaluating the inter-crosslink molecular weight, components other than component (B) and components (A) to (D) (e.g., inorganic fillers) cannot be added. This is because, despite not participating in crosslink formation, these components affect the E'min and other properties of the cured product obtained by curing the composition, preventing an accurate evaluation of the inter-crosslink molecular weight. Although component (D) is not incorporated into the crosslinked structure, its amount is small compared to the total amount of components (A) and (C) because it is a curing accelerator. Therefore, the influence of component (D) remaining unreacted after curing on the inter-crosslink molecular weight is thought to be small.

[0198] In the past, in curable resin compositions containing epoxy group-containing substances, it was common to use large amounts of polyfunctional epoxy group-containing substances with low epoxy equivalent weights as the epoxy group-containing substance, for reasons such as the resulting cured products having excellent heat resistance and / or strength, the compositions having low viscosity and excellent workability, and low cost and economical advantages. Even in rare cases where monofunctional epoxy group-containing substances and epoxy group-containing substances with high epoxy equivalent weights were used, the total amount used was small (less than 5 parts by mass per 100 parts by mass of the epoxy group-containing substance). However, the present inventors first focused on the use of monofunctional epoxy group-containing substances and / or epoxy group-containing substances with high epoxy equivalent weights, which had rarely been used in the past, and solved the above problems by using them in amounts of at least a certain amount, adjusting the molecular weight between crosslinks to a predetermined range, and further using polymer particles, thereby completing the present invention. It is known that dispersing polymer particles (B) in component (A) (e.g., epoxy resin) induces large-scale plastic deformation of the epoxy resin, consuming energy and improving toughness. It is presumed that by adjusting the molecular weight between crosslinks to a value within a predetermined range in the presence of polymer particles (B), the cured product becomes more susceptible to plastic deformation and toughness is significantly improved. In other words, the technical idea of ​​adjusting the molecular weight between crosslinks to a value within a predetermined range can be said to be a technical idea that could never have been conceived of in the prior art.

[0199] <1-2-2. Component (A)> In a curable resin composition that satisfies at least the above (2), the total content of the bisphenol A epoxy resin, bisphenol F epoxy resin, and alicyclic epoxy resin in 100 parts by mass of the component (A) is 5 to 100 parts by mass, preferably 10 to 95 parts by mass, more preferably 10 to 94 parts by mass, more preferably 15 to 93 parts by mass, more preferably 20 to 93 parts by mass, more preferably 25 to 93 parts by mass, more preferably 30 to 93 parts by mass, and more preferably 35 to 93 parts by mass. The amount is more preferably 3 parts by mass, more preferably 40 to 93 parts by mass, more preferably 45 to 93 parts by mass, more preferably 50 to 93 parts by mass, more preferably 50 to 92 parts by mass, more preferably 50 to 90 parts by mass, more preferably 45 to 85 parts by mass, more preferably 50 to 85 parts by mass, more preferably 50 to 80 parts by mass, even more preferably 55 to 80 parts by mass, and particularly preferably 60 to 80 parts by mass. This configuration has the advantages of providing a composition with low viscosity and excellent processability, and further providing a cured product obtained by curing the composition with excellent strength, elastic modulus, and heat resistance (high Tg). In a curable resin composition that satisfies at least the above (2), component (A) may not contain other epoxy group-containing substances (e.g., glycidyl amine-type epoxy resins) as described below.

[0200] In the curable resin composition satisfying at least the above (2), the component (A) satisfies any one of the following (i), (ii), or (iii): (i) the component (A) contains a polyfunctional epoxy group-containing substance (a1), and the content of the polyfunctional epoxy group-containing substance (a1) per 100 parts by mass of the component (A) is 5 to 100 parts by mass; (ii) the component (A) contains a monofunctional epoxy group-containing substance (a2), and the content of the monofunctional epoxy group-containing substance (a2) per 100 parts by mass of the component (A) is 5 to 95 parts by mass; (iii) The component (A) comprises a polyfunctional epoxy group-containing substance (a1) and a monofunctional epoxy group-containing substance (a2), and the content of the polyfunctional epoxy group-containing substance (a1) per 100 parts by mass of the component (A) is 5 to 95 parts by mass, and the content of the monofunctional epoxy group-containing substance (a2) per 100 parts by mass of the component (A) is 5 to 95 parts by mass.

[0201] In a curable resin composition that satisfies at least the above-mentioned condition (2), the component (A) may (i) contain a polyfunctional epoxy group-containing substance (a1) but not contain a monofunctional epoxy group-containing substance (a2), (ii) contain a monofunctional epoxy group-containing substance (a2) but not contain a polyfunctional epoxy group-containing substance (a1), or (iii) contain both a polyfunctional epoxy group-containing substance (a1) and a monofunctional epoxy group-containing substance (a2). In a curable resin composition that satisfies at least the above-mentioned condition (2), when the component (A) contains a polyfunctional epoxy group-containing substance (a1), the cured product obtained by curing the composition has the advantage of excellent toughness. On the other hand, in a curable resin composition that satisfies at least the above-mentioned condition (2), when the component (A) does not contain a polyfunctional epoxy group-containing substance (a1), the composition has the advantage of having a relatively low viscosity and excellent processability. In a curable resin composition that satisfies at least the above condition (2), when component (A) contains a monofunctional epoxy group-containing substance (a2), the composition has the advantages of low viscosity and excellent processability, and further, the cured product obtained by curing the composition has excellent toughness. On the other hand, in a curable resin composition that satisfies at least the above condition (2), when component (A) does not contain a monofunctional epoxy group-containing substance (a2), the composition has the advantages of the cured product obtained by curing the composition having excellent strength and heat resistance (high Tg).

[0202] In a curable resin composition that satisfies at least the above (2), the content of the polyfunctional epoxy group-containing substance (a1) per 100 parts by mass of the component (A) is preferably 5 to 100 parts by mass, more preferably 7 to 50 parts by mass, more preferably 10 to 50 parts by mass, even more preferably 10 to 40 parts by mass, even more preferably 15 to 40 parts by mass, and particularly preferably 15 to 30 parts by mass. This configuration has the advantages of providing a composition with a relatively low viscosity and excellent processability, and further providing a cured product obtained by curing the composition with excellent toughness. In a curable resin composition that satisfies at least the above (2), the upper limit of the content of the polyfunctional epoxy group-containing substance (a1) per 100 parts by mass of the component (A) may be less than 100 parts by mass.

[0203] In a curable resin composition that satisfies at least the above (2), the content of the monofunctional epoxy group-containing substance (a2) per 100 parts by mass of component (A) is preferably 5 to 95 parts by mass, more preferably 7 to 58 parts by mass, more preferably 8 to 50 parts by mass, more preferably 10 to 50 parts by mass, more preferably 15 to 45 parts by mass, more preferably 15 to 40 parts by mass, even more preferably 15 to 35 parts by mass, and particularly preferably 20 to 30 parts by mass. This configuration has the advantages of providing a composition with low viscosity and excellent processability, and further providing a cured product obtained by curing the composition with excellent strength and / or toughness. In a curable resin composition that satisfies at least the above (2), the upper limit of the content of the monofunctional epoxy group-containing substance (a2) per 100 parts by mass of component (A) may be less than 95 parts by mass.

[0204] In a curable resin composition that satisfies at least the above condition (2), the component (A) preferably contains a polyfunctional epoxy group-containing substance (a1) and a monofunctional epoxy group-containing substance (a2), since this has the advantage of providing a cured product obtained by curing the composition with superior toughness. A case in which the component (A) contains a polyfunctional epoxy group-containing substance (a1) and a monofunctional epoxy group-containing substance (a2) in a curable resin composition that satisfies at least the above condition (2) (hereinafter also referred to as "Case C") will be described. In Case C, it is preferable that, per 100 parts by mass of component (A), (i) the content of the polyfunctional epoxy group-containing substance (a1) is 5 to 95 parts by mass and the content of the monofunctional epoxy group-containing substance (a2) is 5 to 95 parts by mass, (ii) the content of the polyfunctional epoxy group-containing substance (a1) is 5 to 50 parts by mass and the content of the monofunctional epoxy group-containing substance (a2) is 5 to 50 parts by mass, more preferably (iii) the content of the polyfunctional epoxy group-containing substance (a1) is 10 to 40 parts by mass and the content of the monofunctional epoxy group-containing substance (a2) is 7 to 40 parts by mass, and particularly preferably (iv) the content of the polyfunctional epoxy group-containing substance (a1) is 15 to 30 parts by mass and the content of the monofunctional epoxy group-containing substance (a2) is 8 to 30 parts by mass. This configuration has the advantages that the composition has low viscosity and excellent processability, and further, the cured product obtained by curing the composition has excellent strength and / or toughness. In Case C, per 100 parts by mass of component (A), the content of (i) the polyfunctional epoxy group-containing substance (a1) may be less than 95 parts by mass, and / or the content of (ii) the monofunctional epoxy group-containing substance (a2) may be less than 95 parts by mass.

[0205] In a curable resin composition that satisfies at least the above condition (2), the polyfunctional epoxy group-containing substance (a1) may be one or more epoxy group-containing substances selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins, or may be an epoxy group-containing substance other than bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins. In a curable resin composition that satisfies at least the above condition (2), the monofunctional epoxy group-containing substance (a2) may be an alicyclic epoxy resin, or may be an epoxy group-containing substance other than alicyclic epoxy resins. In other words, in a curable resin composition that satisfies at least the above condition (2), component (A) may further contain an epoxy group-containing substance other than bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins, i.e., another epoxy group-containing substance.

[0206] In a curable resin composition that satisfies at least the above-mentioned (2), when the composition contains an alicyclic epoxy resin as the component (A), the composition preferably contains an acid anhydride (c1) as the component (C).

[0207] In the curable resin composition satisfying at least the above-mentioned (2), specific aspects of the component (A) other than those described above are the same as those explained in the section <1-1-2. Component (A)>, and therefore, the explanation therefor will be omitted here. Regarding the aspects of the component (A) other than those described above, preferred aspects in the curable resin composition satisfying at least the above-mentioned (1) are also preferred aspects in the curable resin composition satisfying at least the above-mentioned (2).

[0208] <1-2-3. Component (B)> Specific aspects of the component (B) are the same as those described in the section <1-1-3. Component (B)> above, and therefore that description is incorporated herein by reference, and further description will be omitted here. A preferred aspect of the component (B) in a curable resin composition that satisfies at least the above (1) is also a preferred aspect of the component (B) in a curable resin composition that satisfies at least the above (2).

[0209] <1-2-4. Component (C)> In the curable resin composition that satisfies at least the above-described (2), the component (C) is an epoxy curing agent. In the curable resin composition that satisfies at least the above-described (2), the epoxy curing agent of the component (C) includes at least one or more selected from the group consisting of an acid anhydride (c1), an aromatic amine (c2), and an alicyclic amine (c3).

[0210] <Acid Anhydride (c1)> In a curable resin composition that satisfies at least the above condition (2), the case where component (C) contains or is acid anhydride (c1) (hereinafter also referred to as "Case D") will be described. In Case D, the viscosity of the resulting composition can be low and the pot life can be long. As a result, Case D has the advantage of providing excellent processability for the composition. Case D also has the advantages that the composition can be cured at relatively low temperatures by adding a curing accelerator, that the resulting cured product has a relatively good balance in terms of electrical properties, chemical properties, and mechanical properties, and that large molded products can be easily produced due to the low heat generated during curing.

[0211] In a curable resin composition that satisfies at least the above-mentioned (2), when the component (C) contains an acid anhydride (c1), the component (C) preferably does not contain an aromatic amine (c2) or an alicyclic amine (c3), and more preferably is composed only of the acid anhydride (c1).

[0212] Specific examples of the acid anhydride (c1) are the same as those described in the section <Acid anhydride (c1)> in the section <1-1-4. Component (C)> above, and therefore the description therein is incorporated by reference, and further description will be omitted here. A preferred embodiment of the acid anhydride (c1) in a curable resin composition that satisfies at least the above (1) is also a preferred embodiment of the acid anhydride (c1) in a curable resin composition that satisfies at least the above (2).

[0213] <<Aromatic Amine (c2)>> In a curable resin composition that satisfies at least the above-described condition (2), when the component (C) contains an aromatic amine (c2) or is an aromatic amine (c2), the cured product obtained by curing the composition has advantages of excellent heat resistance and high strength and / or toughness.

[0214] In a curable resin composition that satisfies at least the above-described (2), when the component (C) contains an aromatic amine (c2), the component (C) preferably does not contain an acid anhydride (c1) or an alicyclic amine (c3), and more preferably is composed only of an aromatic amine (c2).

[0215] Specific examples of the aromatic amine (c2) are the same as those described in the section <<Aromatic amine (c2)>> in the section <1-1-4. Component (C)>> above, and therefore the description therein is incorporated by reference, and further description will be omitted here. A preferred embodiment of the aromatic amine (c2) in a curable resin composition that satisfies at least the above (1) is also a preferred embodiment of the aromatic amine (c2) in a curable resin composition that satisfies at least the above (2).

[0216] <<Alicyclic amine (c3)>> In a curable resin composition satisfying at least the above condition (2), when the component (C) contains or is an alicyclic amine (c3), the curing rate of the composition is increased, and curing can proceed even at relatively low temperatures and / or curing can be completed in a relatively short time. Therefore, in a curable resin composition satisfying at least the above condition (2), when the component (C) is an alicyclic amine (c3), the molding cycle of the cured product is short, and productivity is excellent. The alicyclic amine (c3) is a curing agent with a fast curing rate. On the other hand, in a curable resin composition satisfying at least the above condition (2), the cured product obtained by curing a composition containing an alicyclic amine (c3) as the component (C) also has the advantage of being relatively heat-resistant and having high strength and / or toughness.

[0217] In a curable resin composition that satisfies at least the above-described (2), when the component (C) contains an alicyclic amine (c3), the component (C) preferably does not contain an acid anhydride (c1) or an aromatic amine (c2), and more preferably is composed only of the alicyclic amine (c3).

[0218] Specific examples of the alicyclic amine (c3) are the same as those explained in the section <1-1-4. Component (C)>, <Alicyclic amine (c3)>, and therefore the explanation therefor is omitted here. A preferred embodiment of the alicyclic amine (c3) in a curable resin composition that satisfies at least the above (1) is also a preferred embodiment of the alicyclic amine (c3) in a curable resin composition that satisfies at least the above (2).

[0219] In a curable resin composition that satisfies at least the above (2), the content of component (C) in the composition is 10 to 200 parts by mass, preferably 11 to 170 parts by mass, more preferably 12 to 150 parts by mass, even more preferably 13 to 130 parts by mass, and particularly preferably 15 to 115 parts by mass, per 100 parts by mass of component (A). This configuration has the advantage that the cured product obtained by curing the composition has excellent strength and toughness.

[0220] In a curable resin composition that satisfies at least the above-mentioned condition (2), the case where the component (C) contains or is the acid anhydride (c1) will be described. In this case, the content of the component (C) in the composition is preferably 40 to 200 parts by mass, more preferably 50 to 170 parts by mass, more preferably 55 to 150 parts by mass, even more preferably 60 to 130 parts by mass, and particularly preferably 65 to 115 parts by mass, per 100 parts by mass of the component (A). This configuration has the advantage that the cured product obtained by curing the composition has excellent strength and toughness.

[0221] In a curable resin composition that satisfies at least the above-mentioned condition (2), the case where component (C) contains aromatic amine (c2) or is aromatic amine (c2) will be described. In this case, the content of component (C) in the composition is 10 to 70 parts by mass, preferably 11 to 60 parts by mass, more preferably 12 to 50 parts by mass, even more preferably 13 to 45 parts by mass, and particularly preferably 15 to 40 parts by mass, per 100 parts by mass of component (A). This configuration has the advantage that the cured product obtained by curing the composition has excellent strength and toughness.

[0222] The following describes a case where component (C) contains an alicyclic amine (c3) or is an alicyclic amine (c3). In this case, the content of component (C) in the composition is 5 to 70 parts by mass, preferably 7 to 60 parts by mass, more preferably 9 to 50 parts by mass, more preferably 11 to 45 parts by mass, even more preferably 13 to 40 parts by mass, and particularly preferably 15 to 35 parts by mass, per 100 parts by mass of component (A). This configuration has the advantage that the cured product obtained by curing the composition has excellent strength and toughness.

[0223] <1-2-5. Component (D)> Specific embodiments of the component (D) are the same as those explained in the section <1-1-5. Component (D)> above, and therefore this description is incorporated herein by reference, and further explanation will be omitted here. A preferred embodiment of the component (D) in a curable resin composition that satisfies at least the above (1) is also a preferred embodiment of the component (D) in a curable resin composition that satisfies at least the above (2).

[0224] <1-2-6. Other ingredients> Specific aspects of the other ingredients are the same as those explained in the section <1-1-6. Other ingredients> above, so that the explanation therefor is incorporated by reference and will not be repeated here.

[0225] <1-2-7. Value Y> Specific aspects of the value Y are the same as those explained in the section <1-1-8. Value Y> above, and therefore, the explanation will be omitted here by citing the explanation therein. A preferred aspect of the value Y in a curable resin composition that satisfies at least the above (1) is also a preferred aspect of the value Y in a curable resin composition that satisfies at least the above (2).

[0226] <1-2-8. Viscosity of curable resin composition> Specific aspects of the viscosity of the curable resin composition are the same as those explained in the section <1-1-9. Viscosity of curable resin composition> above, and therefore that description is incorporated herein by reference, and further explanation will be omitted here. A preferred aspect of the viscosity of a curable resin composition in a curable resin composition that satisfies at least (1) above is also a preferred aspect of the viscosity of a curable resin composition in a curable resin composition that satisfies at least (2) above.

[0227] [1-3. Curable resin composition satisfying at least the above-mentioned (3)] In this section, a curable resin composition satisfying at least the above-mentioned (3) will be described below.

[0228] <1-3-1. Technical Concept Related to Curable Resin Compositions Satisfying at Least Requirement (3)> Conventionally known curable resin compositions have room for further improvement in terms of toughness. Therefore, the present inventors conducted extensive research with the aim of providing a novel curable resin composition that can provide a cured product having excellent toughness.

[0229] In a curable resin composition containing an epoxy group-containing substance (e.g., an epoxy resin), the greater the number of active hydrogen atoms per molecule in the amino groups of the epoxy curing agent, the higher the crosslink density of the cured product. The higher the crosslink density of the cured product, the smaller the molecular weight between crosslink points of the cured product.

[0230] As a result of extensive research, the present inventors have independently and surprisingly obtained the novel finding that by adjusting the molecular weight between crosslink points of the cured product to a value within a specific range and by using polymer particles, the toughness of the cured product can be improved.

[0231] The molecular weight between crosslinks of a cured product can be calculated from the theory of rubber elasticity of crosslinked rubber, for example, using the following formula: Molecular weight between crosslinks = 2 x (1 + μ) x ρ x R x T / E = ρ x R x T / G In the formula, μ represents the Poisson's ratio of the cured product, ρ represents the specific gravity of the cured product, R represents the gas constant, T represents absolute temperature (K), and E and G represent the Young's modulus and rigidity modulus in the rubber-like region of the cured product. The rubber-like region is a region observed on the higher temperature side than the transition region near the glass transition temperature when measuring the temperature dependence of the elastic modulus (Young's modulus, rigidity modulus, etc.), and represents a region in which the temperature dependence of the elastic modulus is flat. Because crosslinked polymers such as epoxy resin cured products do not have a flow region on the higher temperature side than the rubber-like region, E and G in the formula can be expressed as the minimum values ​​of the Young's modulus and rigidity modulus in the rubber-like region. Furthermore, since the Young's modulus in the rubber-like region is roughly equal to the storage modulus determined by dynamic viscoelasticity measurement, which is easy to measure, the molecular weight between crosslinks can be calculated by the following formula: Molecular weight between crosslinks = 2 × (1 + μ) × ρ × R × (273 + Tmin) / E'min In the formula, μ represents the Poisson's ratio of the cured product, ρ represents the specific gravity of the cured product, R represents the gas constant, E'min represents the minimum value of the storage modulus of the cured product, and Tmin represents the temperature (°C) at which the storage modulus of the cured product reaches its minimum value.

[0232] The molecular weight between crosslinks of the cured product (α) obtained by curing the curable resin composition (α) containing an epoxy group-containing substance (component (A)), polymer particles (component (B)), a curing agent (component (C)), and a curing accelerator (component (D)) can be represented by the following formula: Molecular weight between crosslinks of cured product (α)={2×[1+μ(cured product (α))]×ρ(cured product (α))×R×[273+Tmin(cured product (α))] / E'min(cured product (α))}.

[0233] Here, the Poisson's ratio (μ) and specific gravity (ρ) of the cured product depend on the type of resin component (A) of the curable resin composition, i.e., the type and amount of the epoxy group-containing substance, but are hardly affected by this. Therefore, in a cured product of an epoxy group-containing substance, the Poisson's ratio (μ) and specific gravity (ρ) of the cured product can be considered "constants." Furthermore, R is a constant (gas constant). Therefore, the variable portion of the molecular weight between crosslinks of the cured product (α) can be expressed as follows: Variable portion of the molecular weight between crosslinks of the cured product (α) = [273 + Tmin (M)] / [E' (M)].

[0234] In this specification, the above-mentioned "variable portion of the molecular weight between crosslink points of the cured product (α)" is defined as "value Y." That is, as a result of extensive research, the present inventors independently obtained the novel finding that, surprisingly, by setting value Y within a predetermined range and using polymer particles, the toughness of the cured product is improved, and have thus completed the present invention.

[0235] The evaluation of the inter-crosslink molecular weight must be based on measurements of a cured product obtained by curing a composition containing only components (A), (C), and (D). This is because components (A) and (C) form a crosslinked structure, and component (D) can affect the degree of progress of the crosslinking reaction. Conversely, when evaluating the inter-crosslink molecular weight, components other than component (B) and components (A), (C), and (D) (e.g., inorganic fillers) cannot be added. Although these components do not participate in crosslink formation, they affect the E'min and other properties of the cured product obtained by curing the composition, preventing accurate evaluation of the inter-crosslink molecular weight. Although component (D) is not incorporated into the crosslinked structure, its amount is small compared to the total amount of components (A) and (C) because it is a curing accelerator. Therefore, the influence of component (D) remaining unreacted after curing on the inter-crosslink molecular weight is thought to be small.

[0236] In the past, epoxy curing agents used in curable resin compositions typically have a high number of active hydrogen atoms per molecule in the amino group (e.g., four or more) from the viewpoints of the composition's curing rate and the strength of the resulting cured product. Even in rare cases where an epoxy curing agent with a low number of active hydrogen atoms per molecule in the amino group was used, it was typically used in combination with an epoxy curing agent with a high number of active hydrogen atoms per molecule in the amino group, and the epoxy curing agent as a whole typically had a high average number of active hydrogen atoms per molecule in the amino group. However, the present inventors first focused on the use of a large amount of an epoxy curing agent with a low number of active hydrogen atoms per molecule in the amino group, which had rarely been used in the past. By using this, the molecular weight between crosslinks was adjusted to a predetermined range, and by further using polymer particles, the above-mentioned problem was solved, leading to the completion of the present invention. It is known that dispersing polymer particles (B) in component (A) (e.g., epoxy resin) induces large-scale plastic deformation of the epoxy resin, consuming energy and improving toughness. It is presumed that by adjusting the molecular weight between crosslinks to a value within a predetermined range in the presence of polymer particles (B), the cured product becomes more susceptible to plastic deformation and toughness is significantly improved. In other words, the technical idea of ​​adjusting the molecular weight between crosslinks to a value within a predetermined range can be said to be a technical idea that could never have been conceived of in the prior art.

[0237] <1-3-2. Component (A)> In a curable resin composition that satisfies at least the above-described (3), the total content of the bisphenol A epoxy resin, bisphenol F epoxy resin, and alicyclic epoxy resin is 5 to 100 parts by mass, preferably 10 to 100 parts by mass, more preferably 20 to 100 parts by mass, more preferably 30 to 100 parts by mass, more preferably 40 to 100 parts by mass, more preferably 50 to 100 parts by mass, more preferably 60 to 100 parts by mass, more preferably 70 to 100 parts by mass, more preferably 80 to 100 parts by mass, even more preferably 90 to 100 parts by mass, and particularly preferably 95 to 100 parts by mass. In a curable resin composition that satisfies at least the above-mentioned (3), the upper limit of the total content of the bisphenol A epoxy resin, bisphenol F epoxy resin, and alicyclic epoxy resin per 100 parts by mass of the component (A) may be less than 100 parts by mass. This configuration has the advantages of providing a composition with low viscosity and excellent processability, and further providing a cured product obtained by curing the composition with excellent strength, elastic modulus, and heat resistance (high Tg). In a curable resin composition that satisfies at least the above-mentioned (3), the total content of the bisphenol A epoxy resin, bisphenol F epoxy resin, and alicyclic epoxy resin per 100 parts by mass of the component (A) may be 100 parts by mass. In other words, in a curable resin composition that satisfies at least the above-mentioned (3), the component (A) may be composed solely of a bisphenol A type epoxy resin, or may be composed solely of a bisphenol F type epoxy resin, or may be composed solely of an alicyclic epoxy resin, or may be composed solely of a bisphenol A type epoxy resin and an alicyclic epoxy resin, or may be composed solely of a bisphenol F type epoxy resin and an alicyclic epoxy resin, or may be composed solely of a bisphenol A type epoxy resin and a bisphenol F type epoxy resin, or may be composed solely of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, and an alicyclic epoxy resin.In a curable resin composition that satisfies at least the above-mentioned condition (3), the component (A) may not contain other epoxy group-containing substances (such as glycidylamine-type epoxy resins) described below.

[0238] In a curable resin composition that satisfies at least the above condition (3), the component (A) preferably contains a polyfunctional epoxy group-containing substance (a1) and a monofunctional epoxy group-containing substance (a2), since this has the advantage of providing a cured product obtained by curing the composition with superior toughness. A case in which the component (A) contains a polyfunctional epoxy group-containing substance (a1) and a monofunctional epoxy group-containing substance (a2) in a curable resin composition that satisfies at least the above condition (3) (hereinafter also referred to as "Case E") will be described. In Case E, per 100 parts by mass of component (A), (i) the content of the polyfunctional epoxy group-containing substance (a1) is preferably 5 to 95 parts by mass, and the content of the monofunctional epoxy group-containing substance (a2) is preferably 5 to 95 parts by mass, (ii) the content of the polyfunctional epoxy group-containing substance (a1) is more preferably 6 to 50 parts by mass, and the content of the monofunctional epoxy group-containing substance (a2) is more preferably 6 to 50 parts by mass, (iii) the content of the polyfunctional epoxy group-containing substance (a1) is more preferably 7 to 40 parts by mass, and the content of the monofunctional epoxy group-containing substance (a2) is more preferably 7 to 40 parts by mass, and (iv) the content of the polyfunctional epoxy group-containing substance (a1) is 7 to 35 parts by mass, and the content of the monofunctional epoxy group-containing substance (a2) is 7 to 35 parts by mass. It is more preferred that (v) the content of the polyfunctional epoxy group-containing substance (a1) is 8 parts by mass to 33 parts by mass, and the content of the monofunctional epoxy group-containing substance (a2) is 7 parts by mass to 33 parts by mass, (vi) the content of the polyfunctional epoxy group-containing substance (a1) is 9 parts by mass to 30 parts by mass, and the content of the monofunctional epoxy group-containing substance (a2) is 7 parts by mass to 30 parts by mass, (vii) the content of the polyfunctional epoxy group-containing substance (a1) is 10 parts by mass to 25 parts by mass, and the content of the monofunctional epoxy group-containing substance (a2) is 7 parts by mass to 30 parts by mass, and (viii) the content of the polyfunctional epoxy group-containing substance (a1) is 15 parts by mass to 20 parts by mass, and the content of the monofunctional epoxy group-containing substance (a2) is particularly preferred.This configuration has the advantages that the composition has low viscosity and excellent processability, and further, the cured product obtained by curing the composition has excellent strength and / or toughness. In Case E, per 100 parts by mass of component (A), the content of (i) the polyfunctional epoxy group-containing substance (a1) may be less than 95 parts by mass, and / or the content of (ii) the monofunctional epoxy group-containing substance (a2) may be less than 95 parts by mass or less than 40 parts by mass.

[0239] In the curable resin composition satisfying at least the above-mentioned (3), specific aspects of the component (A) other than those described above are the same as those explained in the section <1-1-2. Component (A)>, and therefore, the explanation therefor will be omitted here. Regarding the aspects of the component (A) other than those described above, preferred aspects in the curable resin composition satisfying at least the above-mentioned (1) are also preferred aspects in the curable resin composition satisfying at least the above-mentioned (3).

[0240] <1-3-3. Component (B)> Specific embodiments of the component (B) are the same as those described in the section <1-1-3. Component (B)> above, and therefore that description is incorporated herein by reference, and further description will be omitted here. A preferred embodiment of the component (B) in a curable resin composition that satisfies at least the above (1) is also a preferred embodiment of the component (B) in a curable resin composition that satisfies at least the above (3).

[0241] <1-3-4. Component (C)> In a curable resin composition that satisfies at least the above-mentioned (3), the component (C) is an amine-based epoxy curing agent. In a curable resin composition that satisfies at least the above-mentioned (3), the component (C) can function as a curing agent for the component (A). The amine-based epoxy curing agent that is the component (C) includes at least an amine (c4) having one or two active hydrogen atoms in the amino group per molecule. In this specification, "an amine (c4) having one or two active hydrogen atoms in the amino group per molecule" may be referred to as "amine (c4)."

[0242] <<Amine (c4) Having One or Two Active Hydrogen Groups in the Amino Group Per Molecule>> In a curable resin composition that satisfies at least the above-described condition (3), the component (C) including at least the amine (c4) has the following advantages: (i) a cured product having excellent toughness and elongation properties can be obtained, and (ii) a composition having a low viscosity and excellent handleability can be obtained.

[0243] The amine (c4) is not particularly limited as long as the number of active hydrogen atoms in the amino group is 1 or 2 per molecule. Examples of the amine (c4) include aliphatic amines in which the number of active hydrogen atoms in the amino group is 2 per molecule, such as 3-diethylaminopropylamine, 3-dimethylaminopropylamine, 2-diethylaminoethylamine, 2-dimethylaminoethylamine, piperazine, 2-methylpiperazine, N,N'-dimethylethylenediamine, ethanolamine, n-octylamine, 2-ethylhexylamine, n-dodecylamine, hexylamine, and cyclohexylamine; aromatic amines in which the number of active hydrogen atoms in the amino group is 2 per molecule, such as aniline, o-toluidine, 4-chloro-o-toluidine, 2,4-xylidine, p-cresidine, o-anisidine, 2,4,6-trimethylaniline, 2-naphthylamine, and 4-aminobiphenyl; 1-(2-hydroxybenzoyl)-2-phenylpropanol; aliphatic amines having one active hydrogen atom in the amino group per molecule, such as (hydroxyethyl)piperazine, 1-methylpiperazine, piperidine, 4-methylpiperidine, diethanolamine, di-n-octylamine, di(2-ethylhexyl)amine, di-n-dodecylamine, dihexylamine, dicyclohexylamine, N-methylcyclohexylamine, N-methyl-n-octylamine, and diallylamine; and aromatic amines having one active hydrogen atom in the amino group per molecule, such as N-methylaniline, diphenylamine, N-methyl-p-toluidine, N-phenyl-p-toluidine, N-methyl-m-toluidine, N-methyl-2-naphthalenamine, N-phenyl-2-naphthalenamine, and N-methyl-1-naphthalenamine.

[0244] Among the amines (c4), from the viewpoints of achieving a high curing rate of the composition and excellent productivity of the cured product, aliphatic amines having one or two active hydrogen atoms in the amino group per molecule are preferred, and aliphatic amines having two active hydrogen atoms in the amino group per molecule are more preferred.Furthermore, among the amines (c4), from the viewpoints of achieving a high glass transition temperature and excellent heat resistance of the resulting cured product, aromatic amines having one or two active hydrogen atoms in the amino group per molecule are preferred, and aromatic amines having two active hydrogen atoms in the amino group per molecule are more preferred.

[0245] Among the aliphatic amines having one or two active hydrogen atoms in the amino group per molecule as the amine (c4), from the viewpoint of achieving a faster curing rate of the composition and superior productivity of the cured product, aliphatic amines having an ethylenediamine skeleton or a propylenediamine skeleton, such as 3-diethylaminopropylamine, 3-dimethylaminopropylamine, 2-diethylaminoethylamine, 2-dimethylaminoethylamine, piperazine, 2-methylpiperazine, N,N'-dimethylethylenediamine, 1-(2-hydroxyethyl)piperazine, and 1-methylpiperazine, are more preferred. Furthermore, among these, from the viewpoint of achieving a high boiling point and low volatility, 3-diethylaminopropylamine, 2-diethylaminoethylamine, piperazine, 2-methylpiperazine, and 1-(2-hydroxyethyl)piperazine are even more preferred, with 3-diethylaminopropylamine and 1-(2-hydroxyethyl)piperazine being particularly preferred.

[0246] From the above viewpoint, in the curable resin composition satisfying at least the above (3), the component (C) preferably includes, as the amine (c4), one or more selected from the group consisting of 3-diethylaminopropylamine, 3-dimethylaminopropylamine, 2-diethylaminoethylamine, 2-dimethylaminoethylamine, piperazine, 2-methylpiperazine, N,N'-dimethylethylenediamine, 1-(2-hydroxyethyl)piperazine, and 1-methylpiperazine. In the curable resin composition satisfying at least the above (3), the component (C) preferably contains, as the amine (c4), 20% by mass or more in total of one or more selected from the group consisting of 3-diethylaminopropylamine, 3-dimethylaminopropylamine, 2-diethylaminoethylamine, 2-dimethylaminoethylamine, piperazine, 2-methylpiperazine, N,N'-dimethylethylenediamine, 1-(2-hydroxyethyl)piperazine, and 1-methylpiperazine, based on 100% by mass of the component (C). It is more preferable that the component (C) contains 30% by mass or more, more preferably 50% by mass or more, even more preferably 70% by mass or more, and particularly preferably 100% by mass. In other words, in a curable resin composition that satisfies at least the above-mentioned (3), it is particularly preferable that component (C) consists of only one or more selected from the group consisting of 3-diethylaminopropylamine, 3-dimethylaminopropylamine, 2-diethylaminoethylamine, 2-dimethylaminoethylamine, piperazine, 2-methylpiperazine, N,N'-dimethylethylenediamine, 1-(2-hydroxyethyl)piperazine, and 1-methylpiperazine. This configuration has the advantage of being able to produce a cured product with excellent toughness.

[0247] In a curable resin composition that satisfies at least the above (3), the content of the amine (c4) in the component (C) is 5 to 100% by mass, preferably 20 to 100% by mass, more preferably 30 to 90% by mass, even more preferably 40 to 80% by mass, and particularly preferably 50 to 75% by mass, based on 100% by mass of the component (C). This configuration has the advantage of being able to obtain a cured product that has an excellent balance between toughness and heat resistance.

[0248] <<Alicyclic amine (c5) having four active hydrogen atoms in the amino group per molecule>> In a curable resin composition that satisfies at least the above (3), it is preferable that the (C) component further contains an alicyclic amine (c5) having four active hydrogen atoms in the amino group per molecule. In this specification, the "alicyclic amine (c5) having four active hydrogen atoms in the amino group per molecule" may be referred to as "amine (c5)." In a curable resin composition that satisfies at least the above (3), when the (C) component further contains an amine (c5), it has the advantage of being able to obtain a cured product that has an excellent balance between toughness and heat resistance. Note that alicyclic amines can also be called "alicyclic polyamines."

[0249] The amine (c5) is not particularly limited as long as it is an alicyclic amine (alicyclic polyamine) having four active hydrogen atoms in the amino group per molecule. Examples of the amine (c5) include isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), menthenediamine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, which is a type of spiroacetaldiamine, norbornanediamine, and bis(aminomethyl)tricyclodecane.

[0250] In the curable resin composition that satisfies at least the above (3), the component (C) preferably contains, as the amine (c5), (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), and menthenediamine, and more preferably consists of only one or more selected from the group consisting of (ii) isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, 4,4'-methylenebis(cyclohexylamine), and 4,4'-methylenebis(2-methylcyclohexylamine). (iii) more preferably contains one or more selected from the group consisting of isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, and 4,4'-methylenebis(cyclohexylamine), and more preferably contains one or more selected from the group consisting of isophoronediamine, 1,3-bis(aminomethyl)cyclohexane, and 4,4'-methylenebis(cyclohexylamine), and more preferably contains one or more selected from the group consisting of isophoronediamine and 4,4'-methylenebis(cyclohexylamine), and particularly preferably contains one or more selected from the group consisting of isophoronediamine and 4,4'-methylenebis(cyclohexylamine). This configuration has the advantage of being able to obtain a cured product with excellent toughness.

[0251] In a curable resin composition that satisfies at least the above-described condition (3), the case where component (C) contains amine (c5) will be described. In this case, the content of amine (c5) in component (C) is preferably 0% to 95% by mass, more preferably 5% to 85% by mass, even more preferably 15% to 75% by mass, and particularly preferably 25% to 65% by mass, based on 100% by mass of component (C). This configuration has the advantage of being able to obtain a cured product that has an excellent balance between toughness and heat resistance.

[0252] In a curable resin composition that satisfies at least the above-mentioned (3), the component (C) may further include (i) an amine-based epoxy curing agent other than the amine (c4) and the amine (c5) in addition to the amine (c4), or (ii) an amine-based epoxy curing agent other than the amine (c4) and the amine (c5) in addition to the amine (c4) and the amine (c5).

[0253] Examples of amine-based epoxy curing agents other than amine (c4) and amine (c5) include aliphatic amines having three or more active hydrogen atoms in the amino group per molecule (excluding alicyclic amines having four active hydrogen atoms in the amino group per molecule), and aromatic amines having three or more active hydrogen atoms in the amino group per molecule.

[0254] Examples of aliphatic amines having three or more active hydrogen atoms in the amino group per molecule other than alicyclic amines having four active hydrogen atoms in the amino group per molecule include (i) linear aliphatic polyamines having three or more active hydrogen atoms in the amino group per molecule, such as triethylenetetraamine, diethylenetriamine, tetraethylenepentamine, dipropylenetriamine, and hexamethylenediamine, (ii) aliphatic aromatic amines having three or more active hydrogen atoms in the amino group per molecule, such as metaxylenediamine, and (iii) alicyclic amines having three or more active hydrogen atoms in the amino group per molecule. Other examples of aliphatic amines having three or more active hydrogen atoms in the amino group per molecule include amidoamines, amine-terminated polyethers, amine-terminated butadiene nitrile rubbers, modified aliphatic amines, modified alicyclic amines, modified amidoamines, modified amine-terminated polyethers, and modified amine-terminated butadiene nitrile rubbers, each having three or more active hydrogen atoms in the amino group per molecule. Among these, amidoamines having three or more active hydrogen atoms in the amino group per molecule are preferred because they have the advantage of being able to provide a cured product that has an excellent balance between toughness and heat resistance.

[0255] The amidoamine is a compound produced by condensation of a dicarboxylic acid such as a dimer of tall oil fatty acid (dimer acid) and / or a monocarboxylic acid such as neodecanoic acid with a polyamine such as triethylenetetramine or tetraethylenepentamine. Commercially available amidoamines include Ancamide 910, Ancamide 350A, Versamid 140, and Versamid 115.

[0256] The amine-terminated polyether is an amine-terminated polyether having a polyether backbone and an average of preferably 1.5 to 4 (more preferably 2 to 3) amino and / or imino groups per molecule. Examples of the amine-terminated polyether include poly(oxypropylene)diamine, poly(oxypropylene)triamine, and poly(oxypropylene)tetraamine. Commercially available amine-terminated polyethers include Huntsman 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).

[0257] The amine-terminated butadiene nitrile rubber is a polybutadiene / acrylonitrile copolymer having an average of preferably 1.5 to 4 (more preferably 2 to 3) amino and / or imino groups per molecule and an acrylonitrile monomer content in the main chain of 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 rubbers include Hypro 1300X16 ATBN manufactured by CVC Corporation.

[0258] Examples of modified amine-based curing agents include 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.

[0259] Examples of alicyclic amines (alicyclic polyamines) having 3 or more active hydrogen atoms in the amino group per molecule include N-aminoethylpiperazine.

[0260] In a curable resin composition that satisfies at least the above (3), the content of component (C) is 10 to 200 parts by mass, preferably 11 to 170 parts by mass, more preferably 12 to 150 parts by mass, even more preferably 13 to 130 parts by mass, and particularly preferably 15 to 115 parts by mass, relative to 100 parts by mass of component (A). This configuration has the advantage that the cured product obtained by curing the composition has excellent strength and toughness.

[0261] In a curable resin composition that satisfies at least the above (3), the number of active hydrogen atoms in the amino group of component (C) is preferably 1.5 or more but less than 3.8, more preferably 1.7 to 3.7, even more preferably 1.9 to 3.6, and particularly preferably 2.2 to 3.3, on average per molecule. This configuration has the advantage of being able to obtain a cured product that has an excellent balance between toughness and heat resistance.

[0262] <1-3-5. Component (D)> In a curable resin composition that satisfies at least the above-mentioned (3), the composition may or may not contain the component (D). From the viewpoint of the toughness of the obtained cured product, in a curable resin composition that satisfies at least the above-mentioned (3), the composition preferably does not contain the component (D).

[0263] In a curable resin composition that satisfies at least the above-mentioned (3), specific aspects of the component (D) other than those described above are the same as those explained in the section <1-1-5. Component (D)> above, and therefore, the explanation therefor will be omitted here. Regarding aspects of the component (D) other than those described above, preferred aspects in a curable resin composition that satisfies at least the above-mentioned (1) are also preferred aspects in a curable resin composition that satisfies at least the above-mentioned (3).

[0264] <1-3-6. Other ingredients> Specific aspects of the other ingredients are the same as those explained in the section <1-1-6. Other ingredients> above, so that the explanation therefor is incorporated by reference and will not be repeated here.

[0265] <1-3-7. Value Y> In a curable resin composition that satisfies at least the above (3), the value Y of the composition can reflect the molecular weight between crosslink points of the composition. In a curable resin composition that satisfies at least the above (3), the value Y of the composition is 22 to 400, preferably 25 to 360, more preferably 30 to 320, even more preferably 35 to 280, and particularly preferably 40 to 200. The larger the value Y, the more advantageously the cured product obtained will have excellent elongation properties. The smaller the value Y, the more advantageously the cured product obtained will have excellent strength and heat resistance.

[0266] In a curable resin composition that satisfies at least the above (3), the value Y of the composition can be adjusted by changing (i) the average epoxy equivalent of the epoxy group-containing substance (A) contained in the composition, (ii) the average active hydrogen equivalent of the amine (c4) contained in the composition, (iii) the average number of epoxy groups per molecule of the epoxy group-containing substance (A) contained in the composition, (iv) the average number of active hydrogens in the amino groups per molecule of the amine (c4) contained in the composition, (v) the type and amount of the curing accelerator (D) contained in the composition, and (vi) the amount of the amine (c4) contained in the composition.

[0267] <1-3-8. Viscosity of curable resin composition> Specific aspects of the viscosity of the curable resin composition are the same as those explained in the section <1-1-9. Viscosity of curable resin composition> above, and therefore that description is incorporated herein by reference, and further explanation will be omitted here. A preferred aspect of the viscosity of a curable resin composition in a curable resin composition that satisfies at least (1) above is also a preferred aspect of the viscosity of a curable resin composition in a curable resin composition that satisfies at least (3) above.

[0268] [2. Form of Curable Resin Composition] The present composition may be a one-component type, a two-component type, or a multi-component type having three or more components. When the present composition is used as an adhesive, the present composition (adhesive) is preferably a two-component or multi-component curable resin composition.

[0269] 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 comprising a first component and a second component, wherein the first component comprises the following component (A), and the second component does not comprise the following component (D) or further comprises the following component (D), and the curable resin composition further comprises the following component (B); component (A): an epoxy group-containing substance comprising one or more selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins; component (B): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (D): a curing accelerator; A two-component or multi-component curable resin composition satisfying at least any of the following (1) to (3): (1) The second component further comprises the following component (C), and component (C): an acid anhydride (c1), an aromatic amine (c2), or an alicyclic amine (c3); the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 60 parts by mass to 100 parts by mass, relative to 100 parts by mass of the component (A); the content of the component (B) is 1 part by mass to 100 parts by mass, relative to 100 parts by mass of the component (A); the content of the component (C) is 5 parts by mass to 200 parts by mass, relative to 100 parts by mass of the component (A); and when the component (D) is contained, the content of the component (D) is 0.1 parts by mass to 10.0 parts by mass, relative to 100 parts by mass of the component (A); and the value X calculated by the following formula is 1.05 to 5.50 when the component (C) is the acid anhydride (c1), and 1.30 to 9.00 when the component (C) is the aromatic amine (c2) or the alicyclic amine (c3); Formula: X = {[273 + Tmin(M)] / [273 + Tmin(Meq)]} × [E'(Meq)] / [E'(M)]; (2) The second component further comprises the following component (C): component (C) is an epoxy curing agent comprising at least one selected from the group consisting of an acid anhydride (c1), an aromatic amine (c2), and an alicyclic amine (c3);the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 5 parts by mass to 100 parts by mass per 100 parts by mass of the component (A); the content of the component (B) is 1 part by mass to 100 parts by mass per 100 parts by mass of the component (A); the content of the component (C) is 10 parts by mass to 200 parts by mass per 100 parts by mass of the component (A); and when the component (D) is contained, the content of the component (D) is 0.1 parts by mass to 10.0 parts by mass per 100 parts by mass of the component (A); and the component (A) satisfies any of the following (i), (ii), or (iii): (i) the component (A) contains a polyfunctional epoxy group-containing substance (a1) having an epoxy equivalent of 300 g / eq or more and less than 3000 g / eq and having two or more epoxy groups in one molecule, and the content of the polyfunctional epoxy group-containing substance (a1) is 5 parts by mass to 100 parts by mass per 100 parts by mass of the component (A); (ii) the component (A) contains a monofunctional epoxy group-containing substance (a2) having one epoxy group in one molecule, and the content of the monofunctional epoxy group-containing substance (a2) is 5 parts by mass to 95 parts by mass per 100 parts by mass of the component (A); (iii) the component (A) comprises the polyfunctional epoxy group-containing substance (a1) and the monofunctional epoxy group-containing substance (a2), and the content of the polyfunctional epoxy group-containing substance (a1) in 100 parts by mass of the component (A) is 5 to 95 parts by mass, and the content of the monofunctional epoxy group-containing substance (a2) in 100 parts by mass of the component (A) is 5 to 95 parts by mass; the value Y calculated by the following formula is 22 to 400; Y=[273+Tmin(M)] / [E'(M)]; (3) the second component further comprises the following component (C), an amine-based epoxy curing agent comprising component (C): an amine (c4) having one or two active hydrogen atoms in the amino group per molecule; The total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 5 parts by mass to 100 parts by mass per 100 parts by mass of the component (A), and the content of the component (B) is 1 part by mass to 100 parts by mass per 100 parts by mass of the component (A),the content of the component (C) is 10 parts by mass to 200 parts by mass relative to 100 parts by mass of the component (A); when the component (D) is contained, the content of the component (D) is 0.1 parts by mass to 20.0 parts by mass relative to 100 parts by mass of the component (A); the content of the amine (c4) in the component (C) is 5% by mass to 100% by mass of 100% by mass of the component (C); and the value Y calculated by the following formula is 22 to 400; Y=[273+Tmin(M)] / [E'(M)]; wherein, in the formulas for the value X and the value Y, wherein Ttg(M) (°C) is the temperature at which the loss tangent, determined by performing dynamic viscoelasticity measurement using a cured product (M) of composition (M) as a sample in a tensile mode at a frequency of 1 Hz, is maximized, E'(M) represents the minimum value of the storage modulus (E') of the cured product (M) in the temperature range of [Ttg(M) (°C)] to [Ttg(M) + 25 (°C)], and Tmin(M) (°C) is the temperature (°C) at which the value of E'(M) is obtained, the composition (M) contains the same components (A), (C), and (D) as the components (A), (C), and (D) contained in the curable resin composition, the contents of the component (A), the component (C), and the component (D) in the composition (M) are the same as the contents of the component (A), the component (C), and the component (D) in the curable resin composition, The cured product (M) is a cured product obtained by curing the composition (M), and is a cured product that exhibits a degree of cure of 98% or more by DSC measurement, and in the formula for the value X, Ttg(Meq) (°C) is the temperature at which the loss tangent is maximized when dynamic viscoelasticity is measured using a cured product (Meq) of composition (Meq) as a sample in a tensile mode at a frequency of 1 Hz, E'(Meq) represents the minimum value of the storage modulus (E') of the cured product (Meq) in the temperature range of [Ttg(Meq) (°C)] to [Ttg(Meq) + 25 (°C)], and Tmin(Meq) (°C) is the temperature (°C) at which the value of E'(Meq) is obtained,the composition (Meq) contains the component (A), the component (C), and the component (D) that are the same as the component (A), the component (C), and the component (D) contained in the curable resin composition, the contents of the component (A) and the component (D) in the composition (Meq) are the same as the contents of the component (A) and the component (D) in the curable resin composition, and when the component (C) in the composition (Meq) is the acid anhydride (c1), the content of the component (C) in the composition (Meq) is an amount such that the ratio of the molar amount of acid anhydride groups in the component (C) to the molar amount of epoxy groups in the component (A) contained in the composition (Meq) (molar amount of acid anhydride groups in the component (C) / molar amount of epoxy groups in the component (A)) is 1, When the component (C) in the composition (Meq) is the aromatic amine (c2) or the alicyclic amine (c3), the content of the component (C) in the composition (Meq) is an amount such that the ratio of the molar amount of active hydrogen of the amine in the component (C) to the molar amount of epoxy groups in the component (A) contained in the composition (Meq) (molar amount of active hydrogen of the amine in the component (C) / molar amount of the epoxy groups in the component (A)) is 1, and the cured product (Meq) is a cured product obtained by curing the composition (Meq), and exhibits a degree of cure of 98% or more as measured by DSC.

[0270] The two-component or multi-component curable resin composition described above is also a curable resin composition according to one embodiment of the present invention, i.e., the present composition, and has the advantage of being able to provide a cured product having excellent toughness.

[0271] For specific aspects (e.g., aspects of each component) of the two-component or multi-component curable resin composition described above, 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 two-component or multi-component curable resin composition described above.

[0272] [3. 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 optionally the component (D), as well as other components as necessary, using a known mixing device (e.g., a planetary mixer).

[0273] The present composition is preferably a composition in which the core-shell polymer particles (B) are dispersed in the state of primary particles. For example, such a composition is preferably produced using a polymer particle dispersion composition in which the core-shell polymer particles are dispersed in the state of primary particles. By using the polymer particle dispersion composition, it is possible to easily achieve dispersion of the core-shell polymer particles in the composition in the state of primary particles. The core-shell polymer particles may be present at a high concentration in the polymer particle dispersion composition.

[0274] The present composition can also be produced by directly mixing a powder (powder, granules, or particulate form) of the core-shell polymer particles, which is component (B), with component (A) to disperse the core-shell polymer particles in component (A). However, in order to obtain a composition in which the core-shell polymer particles are dispersed in the state of primary particles and in which there are no aggregates of the core-shell polymer particles, or if there are any, there are very few, it is preferable to obtain the above-mentioned polymer particle dispersion composition and then produce a composition using the polymer particle dispersion composition.

[0275] Various methods can be used to obtain a polymer particle dispersion composition, and examples thereof include the following: a method in which core-shell polymer particles obtained in an aqueous latex state are contacted with component (A) and then unnecessary components such as water are removed; a method in which the core-shell polymer particles are once extracted into an organic solvent, the organic solvent containing the core-shell polymer particles is mixed with component (A), and then the organic solvent is removed from the resulting mixture; etc. As a method for obtaining a polymer particle dispersion composition, it is preferable to use the method described in WO 2005 / 028546. A specific production method for this is a method in which the following first, second, and third steps are carried out in this order: First step: a step of mixing an aqueous latex containing core-shell polymer particles (for example, a reaction mixture obtained after producing core-shell polymer particles by emulsion polymerization) with an organic solvent having a solubility in water at 20°C of 5% by weight to 40% by weight, and then further mixing the resulting mixture with excess water to aggregate the polymer particles; Second step: a step of separating and recovering the aggregated core-shell polymer particles from the liquid phase, and then again mixing the core-shell polymer particles with an organic solvent to obtain an organic solvent solution of the core-shell polymer particles; Third step: a step of further mixing the resulting organic solvent solution with component (A), and then distilling off the organic solvent from the resulting mixture.

[0276] Component (A) is preferably liquid at 23°C. When component (A) is liquid at 23°C, the third step is facilitated. "Liquid at 23°C" means that the softening point is 23°C or lower and that the component exhibits flowability at 23°C.

[0277] By going through the above-described steps 1 to 3, a polymer particle dispersion composition can be obtained in which the core-shell polymer particles (B) of component (A) are dispersed in the state of primary particles. The obtained polymer particle dispersion composition can be mixed with additional components (A), (B), (C), and, if necessary, component (D), as well as other components, if necessary, to obtain a composition. In the composition thus obtained, the core-shell polymer particles can be dispersed in the state of primary particles.

[0278] On the other hand, powdery core-shell polymer particles can be obtained by coagulating the core-shell polymer particles by a method such as salting out and then drying the resulting coagulate. The powdery core-shell polymer particles can be redispersed in the state of primary particles in component (A) 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 high temperature to a mixture of component (A) and component (B) (powdered core-shell polymer particles) enables efficient dispersion of component (B) in component (A). The temperature during dispersion (when applying shear force) is preferably 50°C to 200°C, more preferably 70°C to 170°C, even more preferably 80°C to 150°C, and particularly preferably 90°C to 120°C.

[0279] 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 component (B) can be produced by mixing the above-described components (A) and (B), and optionally other components, using a known mixing device (e.g., a planetary mixer, etc.). In the first component containing components (A) and (B), it is preferable that the core-shell polymer particles of component (B) are dispersed in component (A) as primary particles. In other words, the first component containing components (A) and (B) may be the above-described polymer particle dispersion composition. Alternatively, the second component can be produced by mixing component (C), optionally component (D), and optionally component (B) and other components, using a known mixing device (e.g., a planetary mixer, etc.). The first and second components thus produced are preferably mixed and used immediately before use (e.g., immediately before bonding the adherends or immediately before curing the curable resin composition).

[0280] 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 component (A) and, if necessary, other components 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, if necessary, the component (D), and, if necessary, other components 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).

[0281] When the second component contains the components (C) and (D), storage stability problems such as an increase in the viscosity of the second component after storage may occur. In particular, when the second component contains the acid anhydride (c1) as the component (C) and an imidazole such as 2-ethyl-4-methylimidazole as the component (D), the viscosity of the second component tends to increase over time due to the reaction between the acid anhydride (c1) and the imidazole. When using the second component obtained by pre-mixing the acid anhydride (c1) and the component (D), from the viewpoint of little change in viscosity after storage and excellent storage stability, the component (D) is preferably a tertiary amine such as 2,4,6-tris(dimethylaminomethyl)phenol or N-benzyldimethylamine, or a quaternary ammonium salt such as benzyltriethylammonium chloride, more preferably a tertiary amine having no phenolic hydroxyl group such as N-benzyldimethylamine, or a quaternary ammonium salt such as benzyltriethylammonium chloride, and particularly preferably a quaternary ammonium salt such as benzyltriethylammonium chloride.

[0282] [4. Cured Product] A cured product according to one embodiment of the present invention is a cured product obtained by curing a curable resin composition according to one embodiment of the present invention, such as the curable resin composition described in the above section [1. Curable Resin Composition] and / or a curable resin composition produced by the production method described in the above section [3. Production Method of Curable Resin Composition]. In this specification, the "cured product according to one embodiment of the present invention" may be referred to as the "real cured product" hereinafter. The real cured product can also be said to be a cured product obtained by curing the real composition. The real cured product can also be said to be a cured product containing the real cured product.

[0283] The present cured product has the above-described structure and therefore has the advantage of excellent toughness.

[0284] In the present cured product, the polymer particles of component (B) are preferably dispersed in the state of primary particles.

[0285] The method for producing the cured product, i.e., the method for curing the composition, is not particularly limited. For example, when the composition is a one-component type, the 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. When the composition is a two-component or multi-component type containing a first component and a second component, the first component and the second component can be uniformly mixed using a static mixer or the like, and the resulting mixture can be cured by heating the resulting mixture to a certain temperature (curing temperature) and maintaining the mixture at the curing temperature for a certain time (curing time), thereby obtaining a cured product.

[0286] The curing temperature is not particularly limited as long as it can cure the composition or mixture. The curing temperature is preferably 50°C to 200°C, more preferably 70°C to 180°C, and particularly preferably 90°C to 150°C. When the curing temperature is 50°C or higher, the curing reaction can proceed sufficiently. When the curing temperature is 200°C or lower, there is no risk of deterioration in the physical properties and / or quality of the resulting cured product.

[0287] The curing time is not particularly limited as long as the composition or mixture can be cured. The curing time is preferably 0.5 to 12 hours, more preferably 0.5 to 6 hours, even more preferably 1 to 4 hours, and particularly preferably 1 to 2 hours.

[0288] [5. Adhesive] An adhesive according to one embodiment of the present invention is an adhesive containing a curable resin composition according to one embodiment of the present invention, such as the curable resin composition described in the above section [1. Curable Resin Composition] and / or a curable resin composition produced by the production method described in the above section [3. Method for Producing Curable Resin Composition]. In this specification, "an adhesive according to one embodiment of the present invention" may hereinafter be referred to as "the adhesive of the present invention." The adhesive of the present invention can also be said to be an adhesive containing the composition of the present invention.

[0289] Because the adhesive has the above-described structure, it has the advantage that the cured product obtained by curing has excellent toughness and adhesive strength.

[0290] In the present adhesive, the polymer particles as component (B) are preferably dispersed in the form of primary particles.

[0291] The adhesive is preferably a two-component or multi-component adhesive. When the adhesive is a two-component or multi-component adhesive, it may be, for example, an adhesive containing the two-component or multi-component curable resin composition described above in Section 2. Form of Curable Resin Composition. Alternatively, when the adhesive is a two-component or multi-component adhesive, it may be, for example, in the following form: A two-component or multi-component adhesive comprising a first component and a second component, wherein the first component comprises the following component (A), and the second component does not comprise the following component (D) or further comprises the following component (D), and the adhesive further comprises the following component (B); Component (A): an epoxy group-containing substance comprising one or more selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins; Component (B): polymer particles having a core-shell structure comprising a core layer and a shell layer; Component (D): a curing accelerator; A two-component or multi-component adhesive satisfying at least any of the following (1) to (3): (1) further comprising the following component (C), wherein Component (C): an acid anhydride (c1), an aromatic amine (c2), or an alicyclic amine (c3); the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 60 parts by mass to 100 parts by mass, relative to 100 parts by mass of the component (A); the content of the component (B) is 1 part by mass to 100 parts by mass, relative to 100 parts by mass of the component (A); the content of the component (C) is 5 parts by mass to 200 parts by mass, relative to 100 parts by mass of the component (A); and when the component (D) is contained, the content of the component (D) is 0.1 parts by mass to 10.0 parts by mass, relative to 100 parts by mass of the component (A); and the value X calculated by the following formula is 1.05 to 5.50 when the component (C) is the acid anhydride (c1), and 1.30 to 9.00 when the component (C) is the aromatic amine (c2) or the alicyclic amine (c3); Formula: X = {[273 + Tmin(M)] / [273 + Tmin(Meq)]} × [E'(Meq)] / [E'(M)]; (2) further containing the following component (C):Component (C): an epoxy curing agent containing one or more selected from the group consisting of acid anhydrides (c1), aromatic amines (c2), and alicyclic amines (c3); the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 5 parts by mass to 100 parts by mass, relative to 100 parts by mass of the component (A); the content of the component (B) is 1 part by mass to 100 parts by mass, relative to 100 parts by mass of the component (A); the content of the component (C) is 10 parts by mass to 200 parts by mass, relative to 100 parts by mass of the component (A); and when the component (D) is contained, the content of the component (D) is 0.1 parts by mass to 10.0 parts by mass, relative to 100 parts by mass of the component (A); and the component (A) satisfies any of the following (i), (ii), or (iii): (i) the component (A) contains a polyfunctional epoxy group-containing substance (a1) having an epoxy equivalent of 300 g / eq or more and less than 3000 g / eq and having two or more epoxy groups in one molecule, and the content of the polyfunctional epoxy group-containing substance (a1) is 5 parts by mass to 100 parts by mass per 100 parts by mass of the component (A); (ii) the component (A) contains a monofunctional epoxy group-containing substance (a2) having one epoxy group in one molecule, and the content of the monofunctional epoxy group-containing substance (a2) is 5 parts by mass to 95 parts by mass per 100 parts by mass of the component (A); (iii) the component (A) comprises the polyfunctional epoxy group-containing substance (a1) and the monofunctional epoxy group-containing substance (a2), and the content of the polyfunctional epoxy group-containing substance (a1) in 100 parts by mass of the component (A) is 5 to 95 parts by mass, and the content of the monofunctional epoxy group-containing substance (a2) in 100 parts by mass of the component (A) is 5 to 95 parts by mass; the value Y calculated by the following formula is 22 to 400; formula: Y = [273 + Tmin(M)] / [E'(M)]; (3) an amine-based epoxy curing agent further comprising the following component (C), wherein component (C) is an amine (c4) having one or two active hydrogen atoms in the amino group per molecule; the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 5 parts by mass to 100 parts by mass per 100 parts by mass of the component (A);the content of the component (B) is 1 to 100 parts by mass relative to 100 parts by mass of the component (A); the content of the component (C) is 10 to 200 parts by mass relative to 100 parts by mass of the component (A); when the component (D) is contained, the content of the component (D) is 0.1 to 20.0 parts by mass relative to 100 parts by mass of the component (A); the content of the amine (c4) in the component (C) is 5 to 100% by mass relative to 100% by mass of the component (C); and the value Y calculated by the following formula is 22 to 400; Y=[273+Tmin(M)] / [E'(M)]; wherein, in the formulas for the value X and the value Y, wherein Ttg(M) (°C) is the temperature at which the loss tangent, determined by performing dynamic viscoelasticity measurement using a cured product (M) of composition (M) as a sample in a tensile mode at a frequency of 1 Hz, is maximized, E'(M) represents the minimum value of the storage modulus (E') of the cured product (M) in the temperature range of [Ttg(M) (°C)] to [Ttg(M) + 25 (°C)], and Tmin(M) (°C) is the temperature (°C) at which the value of E'(M) is obtained, the composition (M) contains the same components (A), (C), and (D) as the components (A), (C), and (D) contained in the curable resin composition, the contents of the component (A), the component (C), and the component (D) in the composition (M) are the same as the contents of the component (A), the component (C), and the component (D) in the curable resin composition, The cured product (M) is a cured product obtained by curing the composition (M), and is a cured product that exhibits a degree of cure of 98% or more by DSC measurement, and in the formula for the value X, Ttg(Meq) (°C) is the temperature at which the loss tangent is maximized when dynamic viscoelasticity is measured using a cured product (Meq) of composition (Meq) as a sample in a tensile mode at a frequency of 1 Hz, E'(Meq) represents the minimum value of the storage modulus (E') of the cured product (Meq) in the temperature range of [Ttg(Meq) (°C)] to [Ttg(Meq) + 25 (°C)], and Tmin(Meq) (°C) is the temperature (°C) at which the value of E'(Meq) is obtained,the composition (Meq) contains the component (A), the component (C), and the component (D) that are the same as the component (A), the component (C), and the component (D) contained in the curable resin composition, the contents of the component (A) and the component (D) in the composition (Meq) are the same as the contents of the component (A) and the component (D) in the curable resin composition, and when the component (C) in the composition (Meq) is the acid anhydride (c1), the content of the component (C) in the composition (Meq) is an amount such that the ratio of the molar amount of acid anhydride groups in the component (C) to the molar amount of epoxy groups in the component (A) contained in the composition (Meq) (molar amount of acid anhydride groups in the component (C) / molar amount of epoxy groups in the component (A)) is 1, When the component (C) in the composition (Meq) is the aromatic amine (c2) or the alicyclic amine (c3), the content of the component (C) in the composition (Meq) is an amount such that the ratio of the molar amount of active hydrogen of the amine in the component (C) to the molar amount of epoxy groups in the component (A) contained in the composition (Meq) (molar amount of active hydrogen of the amine in the component (C) / molar amount of the epoxy groups in the component (A)) is 1, and the cured product (Meq) is a cured product obtained by curing the composition (Meq), and exhibits a degree of cure of 98% or more as measured by DSC.

[0292] When the adhesive is a two-component or multi-component adhesive, it may be, for example, in the following form: A two-component or multi-component adhesive comprising a first component and a second component, wherein the first component comprises the following component (A), the second component comprises the following component (C), and either does not comprise the following component (D) or further comprises the following component (D), the adhesive further comprises the following component (B); component (A): an epoxy group-containing substance comprising one or more selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins; component (B): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (C): an amine-based epoxy curing agent comprising an amine (c1) having one or two active hydrogen atoms in the amino group per molecule; component (D): a curing accelerator; and the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin per 100 parts by mass of component (A) is 5 to 100 parts by mass, a two-component or multi-component adhesive in which the content of the (B) component is 1 to 100 parts by mass relative to 100 parts by mass of the (A) component; the content of the (C) component is 10 to 200 parts by mass relative to 100 parts by mass of the (A) component; when the (D) component is contained, the content of the (D) component is 0.1 to 20.0 parts by mass relative to 100 parts by mass of the (A) component; the content of the amine (c1) in the (C) component is 5 to 100% by mass relative to 100% by mass of the (C) component; and a value Y calculated by the following formula is 22 to 400:Y=[273+Tmin(M)] / [E'(M)] wherein, Ttg(M) (°C) is the temperature at which the loss tangent, determined by performing dynamic viscoelasticity measurement in a tensile mode at a frequency of 1 Hz using a cured product (M) of composition (M) as a sample, is maximized, and E'(M) represents the minimum value of the storage modulus (E') of the cured product (M) in the temperature range of [Ttg(M) (°C)] to [Ttg(M)+25(°C)], and Tmin(M) (°C) is the temperature (°C) at which the value of E'(M) is obtained; and composition (M) contains the same components (A), (C), and (D) as the components (A), (C), and (D) contained in the adhesive, The contents of the component (A), the component (C), and the component (D) in the composition (M) are the same as the contents of the component (A), the component (C), and the component (D) in the adhesive, and the cured product (M) is a cured product obtained by curing the composition (M) at a curing temperature of 120°C for a curing time of 2 hours, for example;

[0293] The adhesive can be suitably used for a variety of applications, such as structural adhesives for vehicles and aircraft, structural adhesives for wind power generation, automotive interior materials, general woodworking, furniture, interior decoration, wall materials, and food packaging. Because the adhesive has excellent toughness, it is particularly useful as a structural adhesive for vehicles.

[0294] Furthermore, this adhesive can be cured at temperatures close to room temperature and has excellent toughness, making it suitable for joining different substrates with different linear expansion coefficients, such as joining steel plate and aluminum.

[0295] The adhesive can bond wood, metal, plastic, glass, etc. The adhesive exhibits good adhesion to a variety of substrates, including cold-rolled steel, aluminum, fiberglass-reinforced polyester (FRP), panels of cured thermosetting resins such as carbon fiber-reinforced epoxy resin, panels of carbon fiber-reinforced thermoplastic resin sheets, sheet molding compound (SMC), acrylonitrile-butadiene-styrene copolymer (ABS), polyvinyl chloride (PVC), polycarbonate, polypropylene, TPO, wood, and glass.

[0296] The curing temperature of the adhesive is not particularly limited as long as it can cure the composition or mixture. When the adhesive is a two-component or multi-component adhesive, the curing temperature is preferably 5°C to 50°C, more preferably 10°C to 45°C, and particularly preferably 20°C to 40°C. A curing temperature of 5°C or higher has the advantage that the curing reaction can proceed sufficiently. A curing temperature of 50°C or lower has the advantage that a cured product can be obtained in a highly economical production process at around room temperature.

[0297] The adhesive can be produced using the composition. The method for producing the adhesive is not particularly limited, and known methods can be used.

[0298] [6. Laminate] A laminate according to one embodiment of the present invention is a laminate including at least two substrates and an adhesive layer formed by bonding the at least two substrates together using the adhesive described in the above section [5. Adhesive], i.e., the adhesive according to one embodiment of the present invention, which is cured. In this specification, "a laminate according to one embodiment of the present invention" may hereinafter be referred to as "the laminate."

[0299] The present laminate has the above-described structure and therefore has the advantage of exhibiting high adhesive strength.

[0300] (Substrate) The substrate is not particularly limited. Examples of the substrate include wood, metal, plastic, glass, etc. As the substrate, one of the above-mentioned materials may be used alone, or two or more of them may be used in combination.

[0301] Examples of metals include steel materials such as cold-rolled steel and hot-dip galvanized steel, and aluminum materials such as aluminum and coated aluminum. Examples of plastics include general-purpose plastics, engineering plastics, and various plastic substrates such as composite materials (e.g., CFRP and GFRP).

[0302] The method for producing the laminate is not particularly limited. The laminate can be obtained, for example, by applying the adhesive to one or both of at least two substrates, sandwiching the composition between the substrates and laminating them together, and then curing the adhesive to bond the substrates. When the adhesive is a two-component or multi-component adhesive containing a first component and a second component, the first component and the second component can be uniformly mixed using a static mixer or the like, and the resulting mixture can be applied to one or both of at least two substrates, sandwiching the mixture between the substrates and laminating them together, and then curing the mixture to bond the substrates.

[0303] The curing conditions are not particularly limited. For example, by heating the adhesive to a temperature of 80° C. or higher, preferably 130° C. or higher, and more preferably 150° C. or higher, the adhesive can be cured preferably within 30 minutes, more preferably within 20 minutes, to form an adhesive layer, and a laminate in which at least two substrates are bonded can be obtained.

[0304] In the case of a two-component or multi-component adhesive, the curing conditions are not particularly limited, but for example, the adhesive can be cured at a temperature of 5°C to 50°C, preferably 10°C to 45°C, and more preferably 20°C to 40°C, preferably within 60 minutes, more preferably within 30 minutes, to form an adhesive layer, and a laminate in which at least two substrates are bonded can be obtained.

[0305] From the viewpoint of adhesive strength of the laminate, the thickness of the adhesive layer of the present laminate is preferably 0.001 mm to 5.000 mm, more preferably 0.01 mm to 1.000 mm, and even more preferably 0.10 mm to 0.30 mm. The adhesive layer of the present laminate can also be referred to as the thickness of the present adhesive.

[0306] [7. Fiber-reinforced composite material] A fiber-reinforced composite material according to one embodiment of the present invention comprises a curable resin composition according to one embodiment of the present invention, such as the curable resin composition described in the above section [1. Curable resin composition] and / or a curable resin composition produced by the production method described in the above section [3. Production method of curable resin composition], and fibers. In this specification, "a fiber-reinforced composite material according to one embodiment of the present invention" may hereinafter be referred to as "the present fiber-reinforced composite material."

[0307] Because the fiber-reinforced composite material has the above-described structure, it has the advantage of excellent toughness. Heat resistance is sometimes required for fiber-reinforced composite materials. A cured product obtained by curing the above-described composition also has the advantage of having a high glass transition temperature and excellent heat resistance. Therefore, the fiber-reinforced composite material also has the advantage of excellent heat resistance. In other words, when combined with fibers, the composition can be particularly suitably used in the field of fiber-reinforced composite materials that require heat resistance.

[0308] (Fiber) The fiber is not particularly limited. Examples of the fiber include glass fiber, carbon fiber, aramid fiber, and boron fiber. Since a fiber-reinforced composite material that is lightweight yet has excellent mechanical properties such as strength and elastic modulus can be obtained, the fiber preferably contains carbon fiber, and is particularly preferably carbon fiber (composed only of carbon fiber). As the fiber, one of the above-mentioned types may be used alone, or two or more types may be used in combination.

[0309] Examples of carbon fibers include PAN-based fibers, pitch-based fibers, rayon-based fibers, etc. As the carbon fibers, one of the above-mentioned fibers may be used alone, or two or more of them may be used in combination.

[0310] The fibers may be short fibers or continuous fibers, or a combination of both. The fibers may be used in the form of strands or as a fiber substrate. The fiber substrate may be composed of fibers aligned in one direction, or fibers aligned in one direction (warp) and glass fibers or chemical fibers (weft) that secure the fibers. Specific examples of the fiber substrate that can be used include non-crimp fabrics, mats, woven fabrics, knits, and braids.

[0311] A fiber-reinforced composite material can be obtained by impregnating fibers with the composition and then curing the composition.

[0312] Specific examples of methods for impregnating fibers with the composition are shown below, but the impregnation methods are not limited to these. Examples include (i) a method in which the composition, which has been heated as needed, is formed into a film on a roll and / or release paper, and then the film is transferred to one or both sides of a fiber, and the resulting product is passed through a bending roll or a pressure roll to apply pressure and impregnate the fiber, (ii) a method in which the composition, which has been heated as needed, is applied to the fiber to impregnate it, or (iii) a method in which a tank filled with the composition is heated as needed, and the fiber is immersed in the composition in the tank.

[0313] As described above, the present composition can be suitably used in the production of fiber-reinforced composite materials.

[0314] As will be described later, the present fiber-reinforced composite material can be suitably used to form wheels (particularly vehicle wheels). Furthermore, as will be described later, the present fiber-reinforced composite material can also be suitably used to form pressure vessels (e.g., high-pressure vessels) by coating the outer surface of a tank liner. However, the present fiber-reinforced composite material is not limited to these applications and can also be suitably used as structural members and / or outer panels for aircraft, spacecraft, automobiles, industrial machinery, railroad vehicles, ships, and the like.

[0315] The molding method for obtaining the fiber-reinforced composite materials described above is not particularly limited, and any known method can be used, in which a liquid composition is impregnated into fibers and the resulting composition-impregnated fibers are cured. Specific examples include hand layup, filament winding, pultrusion, wet molding, prepreg, vacuum bagging, pressure bagging, spray-up, autoclave molding, matched die molding, sheet molding compounding (SMC), bulk molding compounding (BMC), continuous lamination, resin transfer molding (RTM), high-pressure resin transfer molding (HP-RTM), and vacuum-assisted RTM (VaRTM). Among these, RTM and VaRTM are preferred because of their relatively high productivity and the ability to obtain fiber-reinforced composite materials with complex shapes. Here, RTM refers to a method in which reinforcing fibers are placed in male and female closed molds made of a rigid material and a liquid resin composition is poured into the closed molds under pressure. VaRTM is a method in which reinforcing fibers are placed between an open mold made of a rigid material and a flexible film (bag), and a liquid resin composition is poured into the mold using vacuum pressure. Filament winding is also suitable.

[0316] [8. Wheel] A wheel according to one embodiment of the present invention includes the fiber-reinforced composite material described in the above section [7. Fiber-reinforced composite material], i.e., the fiber-reinforced composite material according to one embodiment of the present invention. In this specification, the "wheel according to one embodiment of the present invention" may hereinafter be referred to as "the present wheel." The present wheel can also be said to be a wheel made using the present fiber-reinforced composite material. Because the present wheel has the above-described configuration, it has the advantage of excellent toughness.

[0317] The present wheel is preferably a vehicle wheel used for aircraft wheels, spacecraft wheels, automobile wheels, railroad vehicle wheels, etc. Vehicle wheels require toughness. Because the present wheel has excellent toughness, it is particularly suitable for use as a vehicle wheel. In other words, one embodiment of the present invention provides a vehicle wheel including the fiber-reinforced composite material described in the above section [7. Fiber-reinforced composite material], i.e., the fiber-reinforced composite material according to one embodiment of the present invention.

[0318] The manufacturing method (molding method) for obtaining a fiber-reinforced composite material for a wheel, particularly a vehicle wheel, is not particularly limited, and methods such as sheet molding compounding (SMC), resin transfer molding (RTM), high-pressure resin transfer molding (HP-RTM), and vacuum-assisted RTM (VaRTM) can be suitably used.

[0319] [9. High-Pressure Container] A high-pressure container according to one embodiment of the present invention comprises the fiber-reinforced composite material described in the above section [7. Fiber-reinforced composite material], i.e., a fiber-reinforced composite material according to one embodiment of the present invention. In this specification, the "high-pressure container according to one embodiment of the present invention" may hereinafter be referred to as the "present high-pressure container." The present high-pressure container can also be said to be a high-pressure container made using the present fiber-reinforced composite material. Because the present high-pressure container has the above-mentioned configuration, it has the advantage of excellent toughness.

[0320] When producing a pressure vessel (including the present high-pressure vessel), fibers obtained by impregnating fibers with the composition (hereinafter sometimes referred to as "composition-impregnated fibers") are wound around the outer surface of a sealable, gas-barrier, hollow container (also referred to as a tank liner) made of plastic or metal by a filament winding method. When winding the composition-impregnated fibers around the tank liner, known methods such as hoop winding and low-angle or high-angle helical winding can be used. The composition-impregnated fibers are then heated to a predetermined curing temperature to cure the composition, thereby producing a pressure vessel (including the present high-pressure vessel) containing a fiber-reinforced composite material. The resulting pressure vessel can be suitably used as a high-pressure vessel (e.g., a high-pressure hydrogen tank). The curing temperature is not particularly limited, but is preferably about 50°C to 250°C, more preferably 80°C to 200°C, and particularly preferably 100°C to 150°C.

[0321] An embodiment of the present invention may have the following configuration.

[0322] [1] A curable resin composition comprising the following components (A) and (B), and not comprising the following component (D), or further comprising the following component (D): component (A): an epoxy group-containing substance comprising at least one selected from the group consisting of a bisphenol A epoxy resin, a bisphenol F epoxy resin, and an alicyclic epoxy resin; component (B): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (D): a curing accelerator; A curable resin composition satisfying at least any one of the following (1) to (3): (1) further comprising the following component (C): component (C): an acid anhydride (c1), an aromatic amine (c2), or an alicyclic amine (c3); the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 60 parts by mass to 100 parts by mass per 100 parts by mass of the component (A), the content of the component (B) is 1 to 100 parts by mass relative to 100 parts by mass of the component (A), the content of the component (C) is 5 to 200 parts by mass relative to 100 parts by mass of the component (A), and when the component (D) is contained, the content of the component (D) is 0.1 to 10.0 parts by mass relative to 100 parts by mass of the component (A), and the value X calculated by the following formula is 1.05 to 5.50 when the component (C) is the acid anhydride (c1), and 1.30 to 9.00 when the component (C) is the aromatic amine (c2) or the alicyclic amine (c3); Formula: X={[273+Tmin(M)] / [273+Tmin(Meq)]} ×[E'(Meq)] / [E'(M)]; (2) further containing the following component (C), Component (C): an epoxy curing agent containing one or more selected from the group consisting of acid anhydrides (c1), aromatic amines (c2), and alicyclic amines (c3); the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 5 parts by mass to 100 parts by mass per 100 parts by mass of component (A), and the content of component (B) is 1 part by mass to 100 parts by mass per 100 parts by mass of component (A),the content of the component (C) is 10 parts by mass to 200 parts by mass relative to 100 parts by mass of the component (A); when the component (D) is contained, the content of the component (D) is 0.1 parts by mass to 10.0 parts by mass relative to 100 parts by mass of the component (A); the component (A) satisfies any of the following (i), (ii), or (iii); (i) the component (A) contains a polyfunctional epoxy group-containing substance (a1) having an epoxy equivalent of 300 g / eq or more and less than 3000 g / eq and having two or more epoxy groups in one molecule, and the content of the polyfunctional epoxy group-containing substance (a1) is 5 parts by mass to 100 parts by mass relative to 100 parts by mass of the component (A); (ii) the component (A) contains a monofunctional epoxy group-containing substance (a2) having one epoxy group per molecule, and the content of the monofunctional epoxy group-containing substance (a2) is 5 to 95 parts by mass per 100 parts by mass of the component (A); (iii) the component (A) contains the polyfunctional epoxy group-containing substance (a1) and the monofunctional epoxy group-containing substance (a2), and the content of the polyfunctional epoxy group-containing substance (a1) is 5 to 95 parts by mass per 100 parts by mass of the component (A), and the content of the monofunctional epoxy group-containing substance (a2) is 5 to 95 parts by mass per 100 parts by mass of the component (A); the value Y calculated by the following formula is 22 to 400; Formula: Y = [273 + Tmin(M)] / [E'(M)]; (3) further contains the following component (C), Component (C): an amine-based epoxy curing agent containing an amine (c4) having one or two active hydrogen atoms in the amino group per molecule; the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 5 to 100 parts by mass per 100 parts by mass of the component (A), the content of the component (B) is 1 to 100 parts by mass per 100 parts by mass of the component (A), the content of the component (C) is 10 to 200 parts by mass per 100 parts by mass of the component (A), and when the component (D) is contained, the content of the component (D) is 0.1 to 20.0 parts by mass per 100 parts by mass of the component (A),the content of the amine (c4) in the component (C) is 5% by mass to 100% by mass, based on 100% by mass of the component (C), and the value Y calculated by the following formula is 22 to 400; Y=[273+Tmin(M)] / [E'(M)]; wherein, in the formula for the value X and the formula for the value Y, Ttg(M) (°C) is the temperature at which the loss tangent is maximized when dynamic viscoelasticity is measured using a cured product (M) of composition (M) as a sample in a tensile mode at a frequency of 1 Hz, E'(M) represents the minimum value of the storage modulus (E') of the cured product (M) in the temperature range of [Ttg(M) (°C)] to [Ttg(M)+25(°C)], and Tmin(M) (°C) is the temperature (°C) at which the value of E'(M) is obtained, the composition (M) contains the component (A), the component (C), and the component (D) that are the same as the component (A), the component (C), and the component (D) contained in the curable resin composition, the contents of the component (A), the component (C), and the component (D) in the composition (M) are the same as the contents of the component (A), the component (C), and the component (D) in the curable resin composition, the cured product (M) is a cured product obtained by curing the composition (M) and exhibits a degree of cure of 98% or more as measured by DSC, and in the formula for the value X, wherein Ttg(Meq) (°C) is the temperature at which the loss tangent obtained by performing dynamic viscoelasticity measurement on a cured product (Meq) of composition (Meq) as a sample under conditions of tensile mode and a frequency of 1 Hz is maximized, E'(Meq) represents the minimum value of the storage modulus (E') of the cured product (Meq) in the temperature range of [Ttg(Meq) (°C)] to [Ttg(Meq) + 25 (°C)], and Tmin(Meq) (°C) is the temperature (°C) at which the value of E'(Meq) is obtained, and the composition (Meq) contains the same component (A), component (C), and component (D) as the component (A), component (C), and component (D) contained in the curable resin composition, the contents of the component (A) and the component (D) in the composition (Meq) are the same as the contents of the component (A) and the component (D) in the curable resin composition,When the component (C) in the composition (Meq) is the acid anhydride (c1), the content of the component (C) in the composition (Meq) is an amount such that the ratio of the molar amount of acid anhydride groups in the component (C) to the molar amount of epoxy groups in the component (A) contained in the composition (Meq) (molar amount of acid anhydride groups in the component (C) / molar amount of epoxy groups in the component (A)) is 1; when the component (C) in the composition (Meq) is the aromatic amine (c2) or the alicyclic amine (c3), the content of the component (C) in the composition (Meq) is an amount such that the ratio of the molar amount of active hydrogen of the amine in the component (C) to the molar amount of epoxy groups in the component (A) contained in the composition (Meq) (molar amount of active hydrogen of the amine in the component (C) / molar amount of epoxy groups in the component (A)) is 1; The cured product (Meq) is a cured product obtained by curing the composition (Meq), and exhibits a degree of cure of 98% or more as measured by DSC.

[0323] [2] The curable resin composition according to [1], wherein the component (B) includes at least one polymer particle selected from the group consisting of polymer particles (B-1), polymer particles (B-2), and polymer particles (B-3) below: the polymer particles (B-1); polymer particles in which the shell layer has epoxy groups, and the content of the epoxy groups in the shell layer relative to the total mass of the shell layer is 0.2 mmol / g to 5.0 mmol / g; the polymer particles (B-2); Polymer particles in which the core layer is a diene rubber obtained by polymerizing a monomer mixture containing 50.00% by mass to 99.99% by mass of (b1) a conjugated diene monomer, 0.00% by mass to 49.99% by mass of (b2) a vinyl monomer copolymerizable with the conjugated diene monomer, and 0.01% by mass to 3.00% by mass of (b3) a chain transfer agent, wherein the total of the (b1) conjugated diene monomer, the (b2) vinyl monomer copolymerizable with the conjugated diene monomer, and the (b3) chain transfer agent is 100% by mass; the polymer particles (B-3); a polymer particle in which the core layer is a diene rubber obtained by polymerizing a monomer mixture containing 50.00% by mass to 99.99% by mass of (b1) a conjugated diene monomer, 0.00% by mass to 49.99% by mass of (b2) a vinyl monomer copolymerizable with the conjugated diene monomer, and 0.01% by mass to 3.00% by mass of (b3) a chain transfer agent, wherein the total of the (b1) conjugated diene monomer, the (b2) vinyl monomer copolymerizable with the conjugated diene monomer, and the (b3) chain transfer agent is 100% by mass; and the shell layer has epoxy groups, and the content of the epoxy groups in the shell layer relative to the total mass of the shell layer is 0.2 mmol / g to 5.0 mmol / g.

[0324] [3] The curable resin composition according to [1] or [2], wherein the core layer of the component (B) is butadiene rubber and / or butadiene-styrene rubber.

[0325] [4] The curable resin composition according to any one of [1] to [3], wherein the shell layer contains one or more structural units selected from the group consisting of aromatic vinyl units, vinylcyan units, and (meth)acrylate units.

[0326] [5] When the curable resin composition satisfies the above (1), the component (C) is the acid anhydride (c1), and the content of the component (C) in the curable resin composition is an amount such that the ratio of the molar amount of acid anhydride groups in the component (C) to the molar amount of epoxy groups in the component (A) contained in the curable resin composition (molar amount of acid anhydride groups in the component (C) / molar amount of epoxy groups in the component (A)) is 0.35 to 0.87. The curable resin composition according to any one of [1] to [4].

[0327] [6] When the curable resin composition satisfies the above (1), the component (C) is the aromatic amine (c2) or the alicyclic amine (c3), and the content of the component (C) in the curable resin composition is such that the ratio of the molar amount of active hydrogen of the amine in the component (C) to the molar amount of epoxy groups in the component (A) contained in the curable resin composition (molar amount of active hydrogen of the amine in the component (C) / molar amount of the epoxy groups in the component (A)) is 0.67 to 0.87 or 1.10 to 2.40. [7] The curable resin composition according to any one of [1] to [4].

[0328] [7] When the curable resin composition satisfies the above (1), the component (C) is the aromatic amine (c2) or the alicyclic amine (c3), and the content of the component (C) in the curable resin composition is an amount such that the ratio of the molar amount of active hydrogen of the amine in the component (C) to the molar amount of epoxy groups in the component (A) contained in the curable resin composition (molar amount of active hydrogen of the amine in the component (C) / molar amount of the epoxy groups in the component (A)) is 0.67 to 0.87. The curable resin composition according to any one of [1] to [4].

[0329] [8] When the curable resin composition satisfies the above (1) and / or (2), the component (A) further contains a glycidylamine-type epoxy resin, and the content of the glycidylamine-type epoxy resin is 29 parts by mass or less per 100 parts by mass of the component (A). The curable resin composition according to any one of [1] to [7].

[0330] [9] When the curable resin composition satisfies the above (1), the curable resin composition according to any one of [1] to [8], wherein the component (A) satisfies any one of the following (i), (ii), or (iii): (i) the component (A) contains a polyfunctional epoxy group-containing substance (a1) having an epoxy equivalent of 300 g / eq or more and less than 3000 g / eq and having two or more epoxy groups in one molecule, and the content of the polyfunctional epoxy group-containing substance (a1) is 5 parts by mass to 100 parts by mass per 100 parts by mass of the component (A); (ii) the component (A) contains a monofunctional epoxy group-containing substance (a2) having one epoxy group in one molecule, and the content of the monofunctional epoxy group-containing substance (a2) is 5 parts by mass to 40 parts by mass per 100 parts by mass of the component (A); (iii) The component (A) comprises the polyfunctional epoxy group-containing substance (a1) and the monofunctional epoxy group-containing substance (a2), and the content of the polyfunctional epoxy group-containing substance (a1) per 100 parts by mass of the component (A) is 5 to 95 parts by mass, and the content of the monofunctional epoxy group-containing substance (a2) per 100 parts by mass of the component (A) is 5 to 40 parts by mass.

[0331]

[10] When the curable resin composition satisfies the above (3), the number of active hydrogen atoms in the amino group of the component (C) is 1.5 or more and less than 3.8 per molecule on average. The curable resin composition according to any one of [1] to [4].

[0332]

[11] A cured product obtained by curing the curable resin composition according to any one of [1] to

[10] .

[0333]

[12] A laminate comprising at least two substrates and an adhesive layer that bonds the at least two substrates and is formed by curing an adhesive containing the curable resin composition according to any one of [1] to

[10] .

[0334]

[13] A fiber-reinforced composite material comprising the curable resin composition according to any one of [1] to

[10] and fibers.

[0335]

[14] A wheel comprising the fiber-reinforced composite material according to

[13] .

[0336]

[15] A high-pressure vessel comprising the fiber-reinforced composite material according to

[13] .

[0337] An embodiment of the present invention may have the following configuration.

[0338] [A1] A curable resin composition comprising the following components (A), (B), and (C), and either not comprising the following component (D) or further comprising the following component (D): component (A); an epoxy group-containing substance comprising at least one selected from the group consisting of a bisphenol A epoxy resin, a bisphenol F epoxy resin, and an alicyclic epoxy resin; component (B); polymer particles having a core-shell structure comprising a core layer and a shell layer; component (C); an acid anhydride (c1) or an aromatic amine (c2); component (D); a curing accelerator; a curable resin composition in which, relative to 100 parts by mass of the component (A), the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 60 parts by mass to 100 parts by mass; the content of the component (B) is 1 part by mass to 100 parts by mass relative to 100 parts by mass of the component (A); the content of the component (C) is 10 parts by mass to 200 parts by mass relative to 100 parts by mass of the component (A); and, in a case where the component (D) is contained, the content of the component (D) is 0.1 parts by mass to 10.0 parts by mass relative to 100 parts by mass of the component (A); and the value X calculated by the following formula is 1.05 to 5.50 when the component (C) is the acid anhydride (c1), and is 1.30 to 9.00 when the component (C) is the aromatic amine (c2): Formula; X={[273+Tmin （Ｍ） ] / [273+Tmin （Ｍｅｑ） ]} ×[E' （Ｍｅｑ） ] / [E' （Ｍ） Here, the temperature at which the loss tangent becomes maximum when dynamic viscoelasticity is measured using a cured product (M) of composition (M) as a sample under conditions of tensile mode and a frequency of 1 Hz is defined as Ttg. （Ｍ） (° C.), and （Ｍ） is the [Ttg （Ｍ） (°C)] to [Ttg （Ｍ）+25 (°C)], and the Tmin represents the minimum value of the storage modulus (E') in the temperature range of （Ｍ） (°C) is the above E' （Ｍ） The temperature at which the loss tangent is maximized when dynamic viscoelasticity is measured on a cured product (Meq) of the composition (Meq) in a tensile mode at a frequency of 1 Hz. （Ｍｅｑ） (° C.), and （Ｍｅｑ） is the [Ttg （Ｍｅｑ） (°C)] to [Ttg （Ｍｅｑ） +25 (°C)], and the Tmin represents the minimum value of the storage modulus (E') in the temperature range of （Ｍｅｑ） (°C) is the above E' （Ｍｅｑ）is the temperature (°C) at which the value of is obtained, the composition (M) contains the component (A), the component (C), and the component (D) that are the same as the component (A), the component (C), and the component (D) contained in the curable resin composition, and the contents of the component (A), the component (C), and the component (D) in the composition (M) are the same as the contents of the component (A), the component (C), and the component (D) in the curable resin composition, The composition (Meq) contains the component (A), the component (C), and the component (D) that are the same as the component (A), the component (C), and the component (D) contained in the curable resin composition, the contents of the component (A) and the component (D) in the composition (Meq) are the same as the contents of the component (A) and the component (D) in the curable resin composition, and when the component (C) in the composition (Meq) is the acid anhydride (c1), the content of the component (C) in the composition (Meq) is the molar ratio of the epoxy groups in the component (A) contained in the composition (Meq). The content of the component (C) in the composition (Meq) is an amount such that the ratio of the molar amount of acid anhydride groups in the component (C) to the molar amount of epoxy groups in the component (A) contained in the component (A) (molar amount of acid anhydride groups in the component (C) / molar amount of the epoxy groups in the component (A)) is 1, and when the component (C) in the composition (Meq) is the aromatic amine (c2), the content of the component (C) in the composition (Meq) is an amount such that the ratio of the molar amount of active hydrogen of the amine in the component (C) to the molar amount of epoxy groups in the component (A) contained in the composition (Meq) (molar amount of active hydrogen of the amine in the component (C) / molar amount of the epoxy groups in the component (A)) is 1.

[0339] [A2] The curable resin composition according to [A1], wherein the component (B) contains at least one type of polymer particle selected from the group consisting of polymer particles (B-1), polymer particles (B-2), and polymer particles (B-3) shown below: the polymer particles (B-1); polymer particles in which the shell layer has epoxy groups, and the content of the epoxy groups in the shell layer relative to the total mass of the shell layer is 0.2 mmol / g to 5.0 mmol / g; the polymer particles (B-2); diene rubber obtained by polymerizing a monomer mixture in which the core layer contains 50% by mass to 99.99% by mass of (b1) a conjugated diene monomer, 0% by mass to 49.99% by mass of (b2) a vinyl monomer copolymerizable with the conjugated diene monomer, and 0.01% by mass to 3.00% by mass of (b3) a chain transfer agent, and the total amount of the conjugated diene monomer (b1), the vinyl monomer copolymerizable with the conjugated diene monomer (b2), and the chain transfer agent (b3) is 100% by mass. the polymer particles (B-3); the polymer particles (B-4), wherein the core layer is a diene rubber obtained by polymerizing a monomer mixture containing 50% by mass to 99.99% by mass of (b1) a conjugated diene monomer, 0% by mass to 49.99% by mass of (b2) a vinyl monomer copolymerizable with the conjugated diene monomer, and 0.01% by mass to 3.00% by mass of (b3) a chain transfer agent, wherein the total of the (b1) conjugated diene monomer, the (b2) vinyl monomer copolymerizable with the conjugated diene monomer, and the (b3) chain transfer agent is 100% by mass, and the shell layer has epoxy groups, and the content of the epoxy groups in the shell layer relative to the total mass of the shell layer is 0.2 mmol / g to 5.0 mmol / g.

[0340] [A3] The curable resin composition according to [A1] or [A2], wherein the component (C) is the acid anhydride (c1), and the content of the component (C) in the curable resin composition is such that the ratio of the molar amount of acid anhydride groups in the component (C) to the molar amount of epoxy groups in the component (A) contained in the curable resin composition (molar amount of acid anhydride groups in the component (C) / molar amount of epoxy groups in the component (A)) is 0.35 to 0.87.

[0341] [A4] The curable resin composition according to [A1] or [A2], wherein the component (C) is the aromatic amine (c2), and the content of the component (C) in the curable resin composition is such that the ratio of the molar amount of active hydrogen of the amine in the component (C) to the molar amount of epoxy groups in the component (A) contained in the curable resin composition (molar amount of active hydrogen of the amine in the component (C) / molar amount of epoxy groups in the component (A)) is 0.67 to 0.87 or 1.10 to 2.40.

[0342] [A5] The curable resin composition according to [A1] or [A2], wherein the component (C) is the aromatic amine (c2), and the content of the component (C) in the curable resin composition is such that the ratio of the molar amount of active hydrogen of the amine in the component (C) to the molar amount of epoxy groups in the component (A) contained in the curable resin composition (molar amount of active hydrogen of the amine in the component (C) / molar amount of the epoxy groups in the component (A)) is 0.67 to 0.87.

[0343] [A6] The curable resin composition according to any one of [A1] to [A5], wherein the component (A) further contains a glycidylamine-type epoxy resin, and the content of the glycidylamine-type epoxy resin per 100 parts by mass of the component (A) is 29 parts by mass or less.

[0344] [A7] The curable resin composition according to any one of [A1] to [A6], wherein the component (A) satisfies any one of the following (i), (ii), or (iii): (i) the component (A) comprises a polyfunctional epoxy group-containing substance (a1) having an epoxy equivalent of 300 g / eq or more and less than 3000 g / eq and having two or more epoxy groups in one molecule, and the content of the polyfunctional epoxy group-containing substance (a1) in 100 parts by mass of the component (A) is 5 parts by mass to 100 parts by mass; (ii) the component (A) comprises a monofunctional epoxy group-containing substance (a2) having one epoxy group in one molecule, and the content of the monofunctional epoxy group-containing substance (a2) in 100 parts by mass of the component (A) is The content of the monofunctional epoxy group-containing substance (a2) is 5 parts by mass to 40 parts by mass; (iii) the component (A) comprises the polyfunctional epoxy group-containing substance (a1) and the monofunctional epoxy group-containing substance (a2), and the content of the polyfunctional epoxy group-containing substance (a1) is 5 parts by mass to 95 parts by mass per 100 parts by mass of the component (A), and the content of the monofunctional epoxy group-containing substance (a2) is 5 parts by mass to 40 parts by mass per 100 parts by mass of the component (A).

[0345] [A8] The curable resin composition according to [A2], wherein the core layer of the polymer particles (B-1) contains one or more rubbers selected from the group consisting of diene rubbers, (meth)acrylate rubbers, and organosiloxane rubbers.

[0346] [A9] A cured product obtained by curing the curable resin composition according to any one of [A1] to [A8].

[0347] [A10] A fiber-reinforced composite material comprising the curable resin composition according to any one of [A1] to [A8] and fibers.

[0348] [A11] The fiber-reinforced composite material according to [A10], wherein the fiber is a carbon fiber.

[0349] [A12] A wheel comprising the fiber-reinforced composite material according to [A10] or [A11].

[0350] [A13] A vehicle wheel comprising the fiber-reinforced composite material according to [A10] or [A11].

[0351] An embodiment of the present invention may have the following configuration.

[0352] [B1] A curable resin composition comprising the following components (A), (B), and (C), and either not comprising the following component (D) or further comprising the following component (D): component (A); an epoxy group-containing substance comprising at least one selected from the group consisting of a bisphenol A epoxy resin, a bisphenol F epoxy resin, and an alicyclic epoxy resin; component (B); polymer particles having a core-shell structure comprising a core layer and a shell layer; component (C); an alicyclic amine; component (D); a curing accelerator; a curable resin composition in which, relative to 100 parts by mass of the component (A), the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 60 parts by mass to 100 parts by mass; the content of the component (B) is 1 part by mass to 100 parts by mass relative to 100 parts by mass of the component (A); the content of the component (C) is 5 parts by mass to 200 parts by mass relative to 100 parts by mass of the component (A); and, when the component (D) is contained, the content of the component (D) is 0.1 parts by mass to 10.0 parts by mass relative to 100 parts by mass of the component (A); and a value X calculated by the following formula is 1.30 to 9.00:X={[273+Tmin(M)] / [273+Tmin(Meq)]} ×[E'(Meq)] / [E'(M)] wherein, Ttg(M) (°C) is the temperature at which the loss tangent obtained by performing dynamic viscoelasticity measurement in a tensile mode at a frequency of 1 Hz using a cured product (M) of composition (M) as a sample is maximized, E'(M) represents the minimum value of the storage modulus (E') of the cured product (M) in the temperature range of [Ttg(M)(°C)] to [Ttg(M)+25(°C)], and Tmin(M) (°C) is the temperature (°C) at which the value of E'(M) is obtained, A cured product (Meq) of composition (Meq) is used as a sample, and dynamic viscoelasticity measurement is performed under conditions of a tensile mode and a frequency of 1 Hz, and the temperature at which the loss tangent is maximized is defined as Ttg(Meq) (°C), E'(Meq) represents the minimum value of the storage modulus (E') of the cured product (Meq) in the temperature range of [Ttg(Meq) (°C)] to [Ttg(Meq) + 25 (°C)], and Tmin(Meq) (°C) is the temperature (°C) at which the value of E'(Meq) is obtained. the composition (M) contains the component (A), the component (C), and the component (D) that are the same as the component (A), the component (C), and the component (D) that are contained in the curable resin composition, and the contents of the component (A), the component (C), and the component (D) in the composition (M) are the same as the contents of the component (A), the component (C), and the component (D) in the curable resin composition, The composition (Meq) contains the component (A), the component (C), and the component (D) that are the same as the component (A), the component (C), and the component (D) contained in the curable resin composition, the contents of the component (A) and the component (D) in the composition (Meq) are the same as the contents of the component (A) and the component (D) in the curable resin composition, and the content of the component (C) in the composition (Meq) is such that the ratio of the molar amount of active hydrogen of the amine in the component (C) to the molar amount of epoxy groups in the component (A) contained in the composition (Meq) (molar amount of active hydrogen of the amine in the component (C) / molar amount of the epoxy groups in the component (A)) is 1;

[0353] [B2] The curable resin composition according to [B1], wherein the component (B) contains at least one type of polymer particles selected from the group consisting of polymer particles (B-1), polymer particles (B-2), and polymer particles (B-3) shown below: the polymer particles (B-1); polymer particles in which the shell layer has epoxy groups, and the content of the epoxy groups in the shell layer relative to the total mass of the shell layer is 0.2 mmol / g to 5.0 mmol / g; the polymer particles (B-2); diene rubber obtained by polymerizing a monomer mixture in which the core layer contains 50% by mass to 99.99% by mass of (b1) a conjugated diene monomer, 0% by mass to 49.99% by mass of (b2) a vinyl monomer copolymerizable with the conjugated diene monomer, and 0.01% by mass to 3.00% by mass of (b3) a chain transfer agent, and the total amount of the conjugated diene monomer (b1), the vinyl monomer copolymerizable with the conjugated diene monomer (b2), and the chain transfer agent (b3) is 100% by mass. the polymer particles (B-3); the polymer particles (B-4), wherein the core layer is a diene rubber obtained by polymerizing a monomer mixture containing 50% by mass to 99.99% by mass of (b1) a conjugated diene monomer, 0% by mass to 49.99% by mass of (b2) a vinyl monomer copolymerizable with the conjugated diene monomer, and 0.01% by mass to 3.00% by mass of (b3) a chain transfer agent, wherein the total of the (b1) conjugated diene monomer, the (b2) vinyl monomer copolymerizable with the conjugated diene monomer, and the (b3) chain transfer agent is 100% by mass, and the shell layer has epoxy groups, and the content of the epoxy groups in the shell layer relative to the total mass of the shell layer is 0.2 mmol / g to 5.0 mmol / g.

[0354] [B3] The curable resin composition according to [B1] or [B2], wherein the content of the component (C) in the curable resin composition is such that the ratio of the molar amount of active hydrogen of the amine in the component (C) to the molar amount of epoxy groups in the component (A) contained in the curable resin composition (molar amount of active hydrogen of the amine in the component (C) / molar amount of the epoxy groups in the component (A)) is 0.67 to 0.87 or 1.10 to 2.40.

[0355] [B4] The curable resin composition according to [B1] or [B2], wherein the content of the component (C) in the curable resin composition is an amount such that the ratio of the molar amount of active hydrogen of the amine in the component (C) to the molar amount of epoxy groups in the component (A) contained in the curable resin composition (molar amount of active hydrogen of the amine in the component (C) / molar amount of the epoxy groups in the component (A)) is 0.67 to 0.87.

[0356] [B5] The curable resin composition according to any one of [B1] to [B4], wherein the component (A) further contains a glycidylamine-type epoxy resin, and the content of the glycidylamine-type epoxy resin per 100 parts by mass of the component (A) is 29 parts by mass or less.

[0357] [B6] The curable resin composition according to any one of [B1] to [B5], wherein the component (A) satisfies any one of the following (i), (ii), or (iii): (i) the component (A) contains a polyfunctional epoxy group-containing substance (a1) having an epoxy equivalent of 300 g / eq or more and less than 3000 g / eq and having two or more epoxy groups in one molecule, and the content of the polyfunctional epoxy group-containing substance (a1) is 5 parts by mass to 100 parts by mass per 100 parts by mass of the component (A); (ii) the component (A) contains a monofunctional epoxy group-containing substance (a2) having one epoxy group in one molecule, and the content of the monofunctional epoxy group-containing substance (a2) is 5 parts by mass to 100 parts by mass per 100 parts by mass of the component (A); The content of the monofunctional epoxy group-containing substance (a2) is 5 parts by mass to 40 parts by mass; (iii) the component (A) comprises the polyfunctional epoxy group-containing substance (a1) and the monofunctional epoxy group-containing substance (a2), and the content of the polyfunctional epoxy group-containing substance (a1) is 5 parts by mass to 95 parts by mass per 100 parts by mass of the component (A), and the content of the monofunctional epoxy group-containing substance (a2) is 5 parts by mass to 40 parts by mass per 100 parts by mass of the component (A).

[0358] [B7] The curable resin composition according to [B2], wherein the core layer of the polymer particles (B-1) contains one or more rubbers selected from the group consisting of diene rubbers, (meth)acrylate rubbers, and organosiloxane rubbers.

[0359] [B8] A cured product obtained by curing the curable resin composition according to any one of [B1] to [B7].

[0360] [B9] A fiber-reinforced composite material comprising the curable resin composition according to any one of [B1] to [B7] and fibers.

[0361] [B10] The fiber-reinforced composite material according to [B9], wherein the fiber is a carbon fiber.

[0362] [B11] A wheel comprising the fiber-reinforced composite material according to [B9] or [B10].

[0363] [B12] A vehicle wheel comprising the fiber-reinforced composite material according to [B9] or [B10].

[0364] An embodiment of the present invention may have the following configuration.

[0365] [C1] A curable resin composition comprising the following components (A), (B), and (C), and not comprising the following component (D), or further comprising the following component (D): component (A): an epoxy group-containing substance comprising at least one selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins; component (B): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (C): an epoxy curing agent comprising at least one selected from the group consisting of acid anhydrides (c1), aromatic amines (c2), and alicyclic amines (c3); component (D): a curing accelerator; the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 5 parts by mass to 100 parts by mass per 100 parts by mass of the component (A); the content of the component (B) is 1 part by mass to 100 parts by mass per 100 parts by mass of the component (A); the content of the component (C) is 10 parts by mass to 200 parts by mass per 100 parts by mass of the component (A); and when the component (D) is contained, the content of the component (D) is 0.1 parts by mass to 10.0 parts by mass per 100 parts by mass of the component (A); and the component (A) satisfies any of the following (i), (ii), or (iii): (i) the component (A) contains a polyfunctional epoxy group-containing substance (a1) having an epoxy equivalent of 300 g / eq or more and less than 3000 g / eq and having two or more epoxy groups in one molecule, and the content of the polyfunctional epoxy group-containing substance (a1) is 5 parts by mass to 100 parts by mass per 100 parts by mass of the component (A); (ii) the component (A) contains a monofunctional epoxy group-containing substance (a2) having one epoxy group in one molecule, and the content of the monofunctional epoxy group-containing substance (a2) is 5 parts by mass to 95 parts by mass per 100 parts by mass of the component (A); (iii) the component (A) comprises the polyfunctional epoxy group-containing substance (a1) and the monofunctional epoxy group-containing substance (a2), and the content of the polyfunctional epoxy group-containing substance (a1) per 100 parts by mass of the component (A) is 5 parts by mass to 95 parts by mass, and the content of the monofunctional epoxy group-containing substance (a2) per 100 parts by mass of the component (A) is 5 parts by mass to 95 parts by mass;A curable resin composition, wherein the value Y calculated by the following formula is 22 to 400: Formula; Y=[273+Tmin(M)] / [E'(M)] wherein, Ttg(M) (°C) is the temperature at which the loss tangent obtained by performing dynamic viscoelasticity measurement on a cured product (M) of composition (M) as a sample in a tensile mode at a frequency of 1 Hz is maximized, and E'(M) represents the minimum value of the storage modulus (E') of the cured product (M) in the temperature range of [Ttg(M)(°C)] to [Ttg(M)+25(°C)], and Tmin(M) (°C) is the temperature (°C) at which the value of E'(M) is obtained. The composition (M) contains the same components (A), (C), and (D) as the components (A), (C), and (D) contained in the curable resin composition, and the contents of the components (A), (C), and (D) in the composition (M) are the same as the contents of the components (A), (C), and (D) in the curable resin composition, respectively. The cured product (M) is a cured product obtained by curing the composition (M) under the following curing conditions: when the component (C) is the acid anhydride (c1), a curing temperature of 175°C and a curing time of 2 hours; when the component (C) is the aromatic amine (c2), a curing temperature of 175°C and a curing time of 2 hours; when the component (C) is the alicyclic amine (c3), a curing temperature of 120°C and a curing time of 2 hours.

[0366] [C2] The curable resin composition according to [C1], wherein the component (B) includes at least one polymer particle selected from the group consisting of polymer particles (B-1), polymer particles (B-2), and polymer particles (B-3) shown below: the polymer particles (B-1); polymer particles in which the shell layer has epoxy groups, and the content of the epoxy groups in the shell layer relative to the total mass of the shell layer is 0.2 mmol / g to 5.0 mmol / g; The polymer particles (B-2): the core layer is a diene rubber polymer obtained by polymerizing a monomer mixture containing 50% by mass to 99.99% by mass of (b1) a conjugated diene monomer, 0% by mass to 49.99% by mass of (b2) a vinyl monomer copolymerizable with the conjugated diene monomer, and 0.01% by mass to 3.00% by mass of (b3) a chain transfer agent, wherein the total of the (b1) conjugated diene monomer, the (b2) vinyl monomer copolymerizable with the conjugated diene monomer, and the (b3) chain transfer agent is 100% by mass; The polymer particles (B-3): The core layer is a diene rubber obtained by polymerizing a monomer mixture containing 50% by mass to 99.99% by mass of (b1) a conjugated diene monomer, 0% by mass to 49.99% by mass of (b2) a vinyl monomer copolymerizable with the conjugated diene monomer, and 0.01% by mass to 3.00% by mass of (b3) a chain transfer agent, wherein the total of the (b1) conjugated diene monomer, the (b2) vinyl monomer copolymerizable with the conjugated diene monomer, and the (b3) chain transfer agent is 100% by mass, and the shell layer has epoxy groups, and the content of the epoxy groups in the shell layer relative to the total mass of the shell layer is 0.2 mmol / g to 5.0 mmol / g.

[0367] [C3] The curable resin composition according to [C1] or [C2], wherein the component (A) further contains a glycidylamine-type epoxy resin, and the content of the glycidylamine-type epoxy resin per 100 parts by mass of the component (A) is 29 parts by mass or less.

[0368] [C4] The curable resin composition according to [C2], wherein the core layer of the polymer particles (B-1) contains at least one rubber selected from the group consisting of diene rubbers, (meth)acrylate rubbers, and organosiloxane rubbers.

[0369] [C5] The curable resin composition according to any one of [C1] to [C4], wherein the core layer of the component (B) is butadiene rubber and / or butadiene-styrene rubber.

[0370] [C6] The curable resin composition according to any one of [C1] to [C5], wherein the shell layer contains one or more structural units selected from the group consisting of aromatic vinyl units, vinylcyan units, and (meth)acrylate units.

[0371] [C7] A cured product obtained by curing the curable resin composition according to any one of [C1] to [C6].

[0372] [C8] A fiber-reinforced composite material comprising the curable resin composition according to any one of [C1] to [C6] and fibers.

[0373] [C9] The fiber-reinforced composite material according to [C8], wherein the fiber is a carbon fiber.

[0374] [C10] A wheel comprising the fiber-reinforced composite material according to [C8] or [C9].

[0375] [C11] A vehicle wheel comprising the fiber-reinforced composite material according to [C8] or [C9].

[0376] [C12] A high-pressure vessel comprising the fiber-reinforced composite material according to [C8] or [C9].

[0377] An embodiment of the present invention may have the following configuration.

[0378] [D1] A curable resin composition comprising the following components (A), (B), and (C), and which does not comprise the following component (D) or further comprises the following component (D): component (A): an epoxy group-containing substance comprising one or more selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins; component (B): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (C): an amine-based epoxy curing agent comprising an amine (c1) having one or two active hydrogen atoms in the amino group per molecule; component (D): a curing accelerator; the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin is 5 parts by mass to 100 parts by mass per 100 parts by mass of component (A), and the content of component (B) is 1 part by mass to 100 parts by mass relative to 100 parts by mass of component (A), the content of the component (C) is 10 parts by mass to 200 parts by mass relative to 100 parts by mass of the component (A); when the component (D) is contained, the content of the component (D) is 0.1 parts by mass to 20.0 parts by mass relative to 100 parts by mass of the component (A); the content of the amine (c1) in the component (C) is 5% by mass to 100% by mass relative to 100% by mass of the component (C); and a value Y calculated by the following formula is 22 to 400.Y=[273+Tmin(M)] / [E'(M)] wherein, Ttg(M) (°C) is the temperature at which the loss tangent, determined by performing dynamic viscoelasticity measurement in a tensile mode at a frequency of 1 Hz using a cured product (M) of composition (M) as a sample, is maximized, and E'(M) represents the minimum value of the storage modulus (E') of the cured product (M) in the temperature range of [Ttg(M) (°C)] to [Ttg(M)+25(°C)], and Tmin(M) (°C) is the temperature (°C) at which the value of E'(M) is obtained; and composition (M) contains the same component (A), component (C), and component (D) as the component (A), component (C), and component (D) contained in the curable resin composition, The contents of the component (A), the component (C), and the component (D) in the composition (M) are the same as the contents of the component (A), the component (C), and the component (D) in the curable resin composition, and the cured product (M) is a cured product obtained by curing the composition (M) at a curing temperature of 120°C for a curing time of 2 hours;

[0379] [D2] A two-component or multi-component curable resin composition comprising a first component and a second component, wherein the first component comprises the following component (A), the second component comprises the following component (C), and does not comprise the following component (D) or further comprises the following component (D), and the curable resin composition further comprises the following component (B); component (A): an epoxy group-containing substance comprising one or more selected from the group consisting of bisphenol A epoxy resins, bisphenol F epoxy resins, and alicyclic epoxy resins; component (B): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (C): an amine-based epoxy curing agent comprising an amine (c1) having one or two active hydrogen atoms in the amino group per molecule; component (D): a curing accelerator; and the total content of the bisphenol A epoxy resin, the bisphenol F epoxy resin, and the alicyclic epoxy resin per 100 parts by mass of component (A) is 5 to 100 parts by mass, a two-component or multi-component curable resin composition, wherein the content of the component (B) is 1 to 100 parts by mass relative to 100 parts by mass of the component (A); the content of the component (C) is 10 to 200 parts by mass relative to 100 parts by mass of the component (A); when the component (D) is contained, the content of the component (D) is 0.1 to 20.0 parts by mass relative to 100 parts by mass of the component (A); the content of the amine (c1) in the component (C) is 5 to 100% by mass relative to 100% by mass of the component (C); and a value Y calculated by the following formula is 22 to 400:Y=[273+Tmin(M)] / [E'(M)] wherein, Ttg(M) (°C) is the temperature at which the loss tangent, determined by performing dynamic viscoelasticity measurement in a tensile mode at a frequency of 1 Hz using a cured product (M) of composition (M) as a sample, is maximized, and E'(M) represents the minimum value of the storage modulus (E') of the cured product (M) in the temperature range of [Ttg(M) (°C)] to [Ttg(M)+25(°C)], and Tmin(M) (°C) is the temperature (°C) at which the value of E'(M) is obtained; and composition (M) contains the same component (A), component (C), and component (D) as the component (A), component (C), and component (D) contained in the curable resin composition, The contents of the component (A), the component (C), and the component (D) in the composition (M) are the same as the contents of the component (A), the component (C), and the component (D) in the curable resin composition, and the cured product (M) is a cured product obtained by curing the composition (M) at a curing temperature of 120°C for a curing time of 2 hours;

[0380] [D3] The curable resin composition according to [D1] or [D2], wherein the number of active hydrogen atoms in the amino groups of the component (C) is, on average, 1.5 or more and less than 3.8 per molecule.

[0381] [D4] The curable resin composition according to any one of [D1] to [D3], wherein the component (C) further contains an alicyclic amine (c2) having four active hydrogen atoms in the amino group per molecule, and the content of the amine (c2) in the component (C) is 0.1% by mass to 95.0% by mass relative to 100% by mass of the component (C).

[0382] [D5] The curable resin composition according to any one of [D1] to [D4], wherein the component (B) comprises at least one polymer particle selected from the group consisting of polymer particles (B-1), polymer particles (B-2), and polymer particles (B-3) below: the polymer particles (B-1); polymer particles in which the shell layer has epoxy groups, and the content of the epoxy groups in the shell layer relative to the total mass of the shell layer is 0.2 mmol / g to 5.0 mmol / g; the polymer particles (B-2); Polymer particles in which the core layer is a diene rubber obtained by polymerizing a monomer mixture containing 50.00% by mass to 99.99% by mass of (b1) a conjugated diene monomer, 0.00% by mass to 49.99% by mass of (b2) a vinyl monomer copolymerizable with the conjugated diene monomer, and 0.01% by mass to 3.00% by mass of (b3) a chain transfer agent, wherein the total of the (b1) conjugated diene monomer, the (b2) vinyl monomer copolymerizable with the conjugated diene monomer, and the (b3) chain transfer agent is 100% by mass; the polymer particles (B-3); a polymer particle in which the core layer is a diene rubber obtained by polymerizing a monomer mixture containing 50.00% by mass to 99.99% by mass of (b1) a conjugated diene monomer, 0.00% by mass to 49.99% by mass of (b2) a vinyl monomer copolymerizable with the conjugated diene monomer, and 0.01% by mass to 3.00% by mass of (b3) a chain transfer agent, wherein the total of the (b1) conjugated diene monomer, the (b2) vinyl monomer copolymerizable with the conjugated diene monomer, and the (b3) chain transfer agent is 100% by mass; and the shell layer has epoxy groups, and the content of the epoxy groups in the shell layer relative to the total mass of the shell layer is 0.2 mmol / g to 5.0 mmol / g.

[0383] [D6] The curable resin composition according to [D5], wherein the core layer of the polymer particles (B-1) contains at least one rubber selected from the group consisting of diene rubbers, (meth)acrylate rubbers, and organosiloxane rubbers.

[0384] [D7] The curable resin composition according to any one of [D1] to [D6], wherein the core layer of the component (B) is butadiene rubber and / or butadiene-styrene rubber.

[0385] [D8] The curable resin composition according to any one of [D1] to [D7], wherein the shell layer contains one or more structural units selected from the group consisting of aromatic vinyl units, vinylcyan units, and (meth)acrylate units.

[0386] [D9] A cured product obtained by curing the curable resin composition according to any one of [D1] to [D8].

[0387] [D10] An adhesive comprising the curable resin composition according to any one of [D1] to [D8].

[0388] [D11] A laminate comprising at least two substrates and an adhesive layer formed by curing the adhesive according to [D10], which bonds the at least two substrates together.

[0389] [D12] A fiber-reinforced composite material comprising the curable resin composition according to any one of [D1] to [D8] and fibers.

[0390] [D13] The fiber-reinforced composite material according to [D12], wherein the fiber is a carbon fiber.

[0391] [D14] A wheel comprising the fiber-reinforced composite material according to [D12] or [D13].

[0392] [D15] A vehicle wheel comprising the fiber-reinforced composite material according to [D12] or [D13].

[0393] [D16] A high-pressure vessel comprising the fiber-reinforced composite material according to [D12] or [D13].

[0394] 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.

[0395] [Materials] First, the materials used in the examples and comparative examples are listed below.

[0396] <Component (A)> A-(1): Alicyclic epoxy resin <3,4-epoxycyclohexylmethyl (3,4-epoxy) cyclohexanecarboxylate> (manufactured by Daicel, "Celloxide 2021P", epoxy equivalent: 130 g / eq) A-(2): Bisphenol A type epoxy resin <bisphenol A type epoxy resin that is liquid at room temperature> (manufactured by Mitsubishi Chemical, "jER828", epoxy equivalent: 189 g / eq) A-(3): Bisphenol F type epoxy resin <bisphenol F type epoxy resin that is liquid at room temperature> (manufactured by Hexion, "EPON863", epoxy equivalent: 170 g / eq) A-(4): Other polyfunctional epoxy group-containing substance <1,4-butanediol diglycidyl ether> (manufactured by Huntsman, "ERISYS GE-21", epoxy equivalent: 115 g / eq) A-(5): Polyfunctional epoxy group-containing substance (a1) <polypropylene glycol diglycidyl ether> (manufactured by Nippon Steel Chemical & Material, "PG-207", epoxy equivalent: 315 g / eq) A-(6): Polyfunctional epoxy group-containing substance (a1) <bisphenol A type epoxy resin that is solid at room temperature> (manufactured by Mitsubishi Chemical, "jER1001", epoxy equivalent: 480 g / eq) A-(7): Monofunctional epoxy group-containing substance (a2) <o-cresyl glycidyl ether> (manufactured by Huntsman, "ERISYS GE-10", epoxy equivalent: 182 g / eq) A-(8): Glycidylamine type epoxy resin <tetraglycidyldiaminodiphenylmethane> (manufactured by Sumitomo Chemical, "ELM-434VL", epoxy equivalent: 115 g / eq) <Component (B)> As the component (B), polymer particles prepared by the following method were used. As described below, dispersions (M-(1) to M-(11)) in which the prepared component (B) (polymer particles) was dispersed in component (A) (A-(1) or A-(2)) were prepared, and these dispersions were used.

[0397] 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 no...

Claims

1. A curable resin composition comprising the following components (A) and (B), and not comprising the following component (D) or further comprising the following component (D); component (A): an epoxy group-containing substance comprising at least one selected from the group consisting of bisphenol A type epoxy resins, bisphenol F type epoxy resins, and alicyclic epoxy resins; component (B): polymer particles having a core-shell structure comprising a core layer and a shell layer; component (D): a curing accelerator; A curable resin composition satisfying at least any one of the following (1) to (3): (1) further comprising the following component (C), and component (C): an acid anhydride (c1), an aromatic amine (c2), or an alicyclic amine (c3); the total content of the bisphenol A type epoxy resin, the bisphenol F type epoxy resin, and the alicyclic epoxy resin is 60 parts by mass to 100 parts by mass per 100 parts by mass of component (A), the content of the component (B) is 1 part by mass to 100 parts by mass with respect to 100 parts by mass of the component (A), the content of the component (C) is 5 parts by mass to 200 parts by mass with respect to 100 parts by mass of the component (A), and when the component (D) is contained, the content of the component (D) is 0.1 parts by mass to 10.0 parts by mass with respect to 100 parts by mass of the component (A), and a value X calculated by the following formula is: when the component (C) is the acid anhydride (c1), it is 1.05 to 5.50, and when the component (C) is the aromatic amine (c2) or the alicyclic amine (c3), it is 1.30 to 9.00; Formula; X={[273+Tmin(M)] / [273+Tmin(Meq)]} ×[E'(Meq)] / [E'(M)]; (2) further containing the following component (C), Component (C): an epoxy curing agent containing one or more selected from the group consisting of acid anhydrides (c1), aromatic amines (c2), and alicyclic amines (c3); the total content of the bisphenol A type epoxy resin, the bisphenol F type epoxy resin, and the alicyclic epoxy resin is 5 parts by mass to 100 parts by mass in 100 parts by mass of component (A), and the content of component (B) is 1 part by mass to 100 parts by mass relative to 100 parts by mass of component (A),the content of the component (C) is 10 parts by mass to 200 parts by mass relative to 100 parts by mass of the component (A); when the component (D) is contained, the content of the component (D) is 0.1 parts by mass to 10.0 parts by mass relative to 100 parts by mass of the component (A); the component (A) satisfies any of the following (i), (ii) or (iii); (i) the component (A) contains a polyfunctional epoxy group-containing substance (a1) having an epoxy equivalent of 300 g / eq or more and less than 3000 g / eq and having two or more epoxy groups in one molecule, and the content of the polyfunctional epoxy group-containing substance (a1) is 5 parts by mass to 100 parts by mass relative to 100 parts by mass of the component (A); (ii) the component (A) contains a monofunctional epoxy group-containing substance (a2) having one epoxy group in one molecule, and the content of the monofunctional epoxy group-containing substance (a2) in 100 parts by mass of the component (A) is 5 parts by mass to 95 parts by mass; (iii) the component (A) contains the polyfunctional epoxy group-containing substance (a1) and the monofunctional epoxy group-containing substance (a2), and the content of the polyfunctional epoxy group-containing substance (a1) in 100 parts by mass of the component (A) is 5 parts by mass to 95 parts by mass, and the content of the monofunctional epoxy group-containing substance (a2) in 100 parts by mass of the component (A) is 5 parts by mass to 95 parts by mass; the value Y calculated by the following formula is 22 to 400; Formula: Y = [273 + Tmin (M)] / [E' (M)]; (3) further contains the following component (C), Component (C): an amine-based epoxy curing agent containing an amine (c4) having one or two active hydrogen atoms in the amino group per molecule; the total content of the bisphenol A type epoxy resin, the bisphenol F type epoxy resin, and the alicyclic epoxy resin is 5 parts by mass to 100 parts by mass in 100 parts by mass of the component (A), the content of the component (B) is 1 part by mass to 100 parts by mass relative to 100 parts by mass of the component (A), the content of the component (C) is 10 parts by mass to 200 parts by mass relative to 100 parts by mass of the component (A), and when the component (D) is contained, the content of the component (D) is 0.1 parts by mass to 20.0 parts by mass relative to 100 parts by mass of the component (A),the content of the amine (c4) in the component (C) is 5% by mass to 100% by mass, based on 100% by mass of the component (C), and a value Y calculated by the following formula is 22 to 400; Y=[273+Tmin(M)] / [E'(M)]; wherein, in the formula for value X and the formula for value Y, Ttg(M) (°C) is the temperature at which the loss tangent obtained by performing dynamic viscoelasticity measurement on a cured product (M) of composition (M) as a sample in a tensile mode at a frequency of 1 Hz is maximized, E'(M) represents the minimum value of the storage modulus (E') of the cured product (M) in the temperature range of [Ttg(M)(°C)] to [Ttg(M)+25(°C)], and Tmin(M) (°C) is the temperature (°C) at which the value of E'(M) is obtained, the composition (M) contains the component (A), the component (C), and the component (D) which are the same as the component (A), the component (C), and the component (D) contained in the curable resin composition, the contents of the component (A), the component (C), and the component (D) in the composition (M) are the same as the contents of the component (A), the component (C), and the component (D) in the curable resin composition, the cured product (M) is a cured product obtained by curing the composition (M) and exhibits a degree of cure of 98% or more as measured by DSC, and in the formula for the value X, a temperature at which the loss tangent is maximized when a dynamic viscoelastic measurement is performed on a cured product (Meq) of composition (Meq) under conditions of a tensile mode and a frequency of 1 Hz, the temperature being designated as Ttg(Meq) (°C), E'(Meq) represents the minimum value of the storage modulus (E') of the cured product (Meq) in the temperature range of [Ttg(Meq) (°C)] to [Ttg(Meq)+25 (°C)], and Tmin(Meq) (°C) is the temperature (°C) at which the value of E'(Meq) is obtained, the composition (Meq) contains the same component (A), component (C), and component (D) as the component (A), component (C), and component (D) contained in the curable resin composition, the contents of the component (A) and the component (D) in the composition (Meq) are the same as the contents of the component (A) and the component (D) in the curable resin composition,When the component (C) in the composition (Meq) is the acid anhydride (c1), the content of the component (C) in the composition (Meq) is an amount such that the ratio of the molar amount of the acid anhydride groups in the component (C) to the molar amount of the epoxy groups in the component (A) contained in the composition (Meq) (the molar amount of the acid anhydride groups in the component (C) / the molar amount of the epoxy groups in the component (A)) is 1; when the component (C) in the composition (Meq) is the aromatic amine (c2) or the alicyclic amine (c3), the content of the component (C) in the composition (Meq) is an amount such that the ratio of the molar amount of the active hydrogen of the amine in the component (C) to the molar amount of the epoxy groups in the component (A) contained in the composition (Meq) (the molar amount of the active hydrogen of the amine in the component (C) / the molar amount of the epoxy groups in the component (A)) is 1; The cured product (Meq) is a cured product obtained by curing the composition (Meq), and has a degree of cure of 98% or more as measured by DSC.

2. The curable resin composition according to claim 1, wherein the component (B) contains at least one type of polymer particle selected from the group consisting of the following polymer particles (B-1), (B-2), and (B-3): the polymer particle (B-1); the polymer particle in which the shell layer has an epoxy group, and the content of the epoxy group in the shell layer relative to the total mass of the shell layer is 0.2 mmol / g to 5.0 mmol / g; the polymer particle (B-2); Polymer particles in which the core layer is a diene-based rubber obtained by polymerizing a monomer mixture containing 50.00% by mass to 99.99% by mass of (b1) a conjugated diene-based monomer, 0.00% by mass to 49.99% by mass of (b2) a vinyl-based monomer copolymerizable with the conjugated diene-based monomer, and 0.01% by mass to 3.00% by mass of (b3) a chain transfer agent, the total of the conjugated diene-based monomer (b1), the vinyl-based monomer copolymerizable with the conjugated diene-based monomer (b2), and the chain transfer agent (b3) being 100% by mass; the polymer particles (B-3); The core layer is a diene-based rubber obtained by polymerizing a monomer mixture containing 50.00 mass % to 99.99 mass % of a conjugated diene-based monomer (b1), 0.00 mass % to 49.99 mass % of a vinyl-based monomer copolymerizable with the conjugated diene-based monomer (b2), and 0.01 mass % to 3.00 mass % of a chain transfer agent (b3), wherein the total of the conjugated diene-based monomer (b1), the vinyl-based monomer copolymerizable with the conjugated diene-based monomer (b2), and the chain transfer agent (b3) is 100 mass %, and the shell layer has epoxy groups, and a content of the epoxy groups in the shell layer relative to the total mass of the shell layer is 0.2 mmol / g to 5.0 mmol / g.

3. The curable resin composition according to claim 1 or 2, wherein the core layer of component (B) is butadiene rubber and / or butadiene-styrene rubber.

4. The curable resin composition according to any one of claims 1 to 3, wherein the shell layer contains one or more structural units selected from the group consisting of aromatic vinyl units, vinylcyan units, and (meth)acrylate units.

5. The curable resin composition according to any one of claims 1 to 4, wherein, when the curable resin composition satisfies the condition (1), the component (C) is the acid anhydride (c1), and the content of the component (C) in the curable resin composition is an amount such that a ratio of the molar amount of acid anhydride groups in the component (C) to the molar amount of epoxy groups in the component (A) contained in the curable resin composition (molar amount of acid anhydride groups in the component (C) / molar amount of epoxy groups in the component (A)) is 0.35 to 0.

87.

6. The curable resin composition according to any one of claims 1 to 4, wherein, when the curable resin composition satisfies (1), the component (C) is the aromatic amine (c2) or the alicyclic amine (c3), and the content of the component (C) in the curable resin composition is an amount such that the ratio of the molar amount of active hydrogen of the amine in the component (C) to the molar amount of epoxy groups in the component (A) contained in the curable resin composition (the molar amount of active hydrogen of the amine in the component (C) / the molar amount of the epoxy groups in the component (A)) is 0.67 to 0.87 or 1.10 to 2.

40.

7. The curable resin composition according to any one of claims 1 to 4, wherein, when the curable resin composition satisfies (1), the component (C) is the aromatic amine (c2) or the alicyclic amine (c3), and the content of the component (C) in the curable resin composition is an amount such that a ratio of the molar amount of active hydrogen of the amine in the component (C) to the molar amount of epoxy groups in the component (A) contained in the curable resin composition (molar amount of active hydrogen of the amine in the component (C) / molar amount of the epoxy groups in the component (A)) is 0.67 to 0.

87.

8. The curable resin composition according to any one of claims 1 to 7, wherein, when the curable resin composition satisfies the (1) and / or (2), the component (A) further contains a glycidylamine-type epoxy resin, and the content of the glycidylamine-type epoxy resin per 100 parts by mass of the component (A) is 29 parts by mass or less.

9. The curable resin composition according to any one of claims 1 to 8, in the case where the curable resin composition satisfies the above (1), the component (A) satisfies any one of the following (i), (ii) or (iii): (i) the component (A) contains a polyfunctional epoxy group-containing substance (a1) having an epoxy equivalent of 300 g / eq or more and less than 3000 g / eq and having two or more epoxy groups in one molecule, and the content of the polyfunctional epoxy group-containing substance (a1) in 100 parts by mass of the component (A) is 5 parts by mass to 100 parts by mass; (ii) the component (A) contains a monofunctional epoxy group-containing substance (a2) having one epoxy group in one molecule, and the content of the monofunctional epoxy group-containing substance (a2) in 100 parts by mass of the component (A) is 5 parts by mass to 40 parts by mass; (iii) The component (A) contains the polyfunctional epoxy group-containing substance (a1) and the monofunctional epoxy group-containing substance (a2), and the content of the polyfunctional epoxy group-containing substance (a1) in 100 parts by mass of the component (A) is 5 parts by mass to 95 parts by mass, and the content of the monofunctional epoxy group-containing substance (a2) in 100 parts by mass of the component (A) is 5 parts by mass to 40 parts by mass.

10. The curable resin composition according to any one of claims 1 to 4, wherein, when the curable resin composition satisfies the condition (3), the number of active hydrogens in the amino groups of the component (C) is, on average, 1.5 or more and less than 3.8 per molecule.

11. A cured product obtained by curing the curable resin composition according to any one of claims 1 to 10.

12. A laminate comprising at least two substrates and an adhesive layer that bonds the at least two substrates and is formed by curing an adhesive that contains the curable resin composition according to any one of claims 1 to 10.

13. A fiber-reinforced composite material comprising the curable resin composition according to any one of claims 1 to 10 and fibers.

14. A wheel comprising the fiber reinforced composite material of claim 13.

15. A high pressure vessel comprising the fiber reinforced composite material of claim 13.

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