Epoxy resin composition, epoxy resin-cured product, and epoxy adhesive

Abstract

The present invention is an epoxy resin composition that is characterized by comprising: (A) an epoxy resin containing two or more epoxy groups in one molecule; (B) a prepolymer that is a reaction product of the following (B-1) and (C-1); (B-1) a urethane bond-containing polyorganosiloxane represented by general formula (1) below; (C-1) an aromatic amine curing agent in an amount such that the number of N-H bonds in the (C-1) is at least twice the number of the epoxy groups in the (B-1); and (C-2) a non-aromatic amine curing agent. Thus, provided are an epoxy resin composition having a composition that exhibits a property of increasing both elongation characteristics and tensile shear strength, even when a curing temperature is reduced, while controlling a domain size; a cured product thereof; and an epoxy adhesive.

Description

Epoxy resin composition, epoxy resin cured product, and epoxy adhesive

[0001] The present invention relates to an epoxy resin composition, a cured product thereof, and an epoxy adhesive.

[0002] In recent years, the transition from conventional engine vehicles to electric vehicles has been progressing, and the manufacturing methods of automotive structures have also been changing dramatically. Furthermore, with regard to the components to be bonded, in addition to the joining of homogeneous materials, there is an increasing need to join dissimilar materials, such as aluminum and steel, aluminum and steel plate, and aluminum and carbon fiber composite (CFRP), in order to reduce the weight of the vehicle body. Epoxy adhesives are primarily used as body shell adhesives to join such dissimilar materials and increase the rigidity of automobiles. Epoxy adhesives play a very important role as adhesives for joining automobiles due to their excellent mechanical strength, electrical insulation, heat resistance, chemical resistance, water resistance, low shrinkage, and adhesion.

[0003] However, even epoxy adhesives capable of achieving high-strength adhesion have the problem of low toughness, i.e., low impact peel strength. To solve this problem, development is underway for epoxy adhesives containing polyurethane polymers terminated with epoxy groups as an impact modifier, as described in Patent Document 1.

[0004] However, with epoxy adhesives of the above structure, it is very difficult to increase both the elongation and tensile shear strength by mixing a urethane polymer. Furthermore, in recent years, attention has been focused on technologies for joining dissimilar materials with resins such as CFRP, but while improving both the elongation and tensile shear strength, there is also a need to reduce the curing temperature conditions in consideration of the heat resistance of the resin and the environmental impact.

[0005] Special Publication No. 2010-521570

[0006] In view of the above problems, an object of the present invention is to provide an epoxy resin composition having a composition that exhibits the properties of increasing both elongation and tensile shear strength even when the curing temperature is lowered while controlling the domain size, a cured product thereof, and an epoxy adhesive.

[0007] In order to solve the above problems, the present invention provides an epoxy resin composition comprising: (A) an epoxy resin containing two or more epoxy groups in one molecule; (B) a prepolymer which is a reaction product of the following (B-1) and (C-1); (B-1) a urethane bond-containing polyorganosiloxane represented by the following general formula (1); (In the formula, R １ are each independently a group selected from an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms, or a hydroxyl group; X are each independently an alkylene group having 1 to 10 carbon atoms; Y are each independently a group selected from an alkylene group having 5 to 30 carbon atoms, an arylene group having 6 to 30 carbon atoms, and an aralkylene group having 7 to 30 carbon atoms; and Z are each independently an alkylene group having 1 to 20 carbon atoms, wherein the alkylene group in Y and Z may have one or more ether bonds in the molecular chain; n is an integer of 0 to 100, and m is 1 or 2.) (C-1) an aromatic amine curing agent in an amount such that the number of N—H bonds in (C-1) is at least twice the number of epoxy groups in (B-1); and (C-2) a non-aromatic amine curing agent.

[0008] In such an epoxy resin composition, the polyorganosiloxane moiety in the prepolymer (B) is poorly compatible with the epoxy resin (A), resulting in the formation of a sea-island structure in which the component (B) forms islands and the component (A) forms a sea. The presence of urethane groups in the (B-1) component of the (B) component causes partial crystallization within the island components, resulting in the formation of a high-strength siloxane urethane polymer that cannot be achieved with siloxane alone. Furthermore, the urethane bonds in the (B) component and the residues resulting from the reaction of the epoxy groups in the (B-1) component with some of the N-H bonds in the (C-1) component have good affinity with the epoxy resin (A), resulting in adequate compatibility at the interface between the island and sea regions. Furthermore, the prepolymer (B), a constituent element of the epoxy resin composition of the present invention, is formed by the reaction of the epoxy groups in the (B-1) component with some of the N-H groups in the (C-1) component. Since it contains amino groups derived from the (C-1) component, it also bonds with the epoxy resin (A). As a result, in the state where a sea-island structure is formed, the island structures centered on component (B) are linked to component (A) of the sea structure to form an epoxy resin structure, which results in an epoxy resin composition that can increase both elongation properties and tensile shear strength compared to a case where component (B) is not present.

[0009] Furthermore, by shortening the molecular chain length of the general formula (1) by setting m to 1 or 2, the island structures formed have good dispersibility, and an epoxy resin can be obtained without the island components coalescing and separating. At the same time, the strength of the siloxane urethane polymer can be further increased. Furthermore, by shortening the molecular chain length of the general formula (1) by setting m to 1 or 2, the distance between the epoxy groups at both ends of component (B) is shortened, which strengthens the epoxy resin structure itself.

[0010] The present invention is characterized in that the component (C) contains (C-1) an aromatic amine curing agent and (C-2) a non-aromatic amine curing agent.

[0011] The use of the aromatic amine curing agent (C-1) provides good curing properties, and by forming a prepolymer with the component (B-1), compatibility with the component (A) is partially improved, allowing control of the island structure. Furthermore, the inclusion of the non-aromatic amine curing agent (C-2) allows for a reduction in the curing temperature. Furthermore, the size of the island structures of the component (B) can be controlled, resulting in good curing properties.

[0012] In the present invention, the component (A) is preferably a bisphenol-type epoxy resin.

[0013] Such an epoxy resin composition can enhance the properties of various selected and used bisphenol-type epoxy resins, and can provide an epoxy resin composition that can increase both the elongation properties and the tensile shear strength compared to when the bisphenol-type epoxy resin is used alone.

[0014] In the present invention, the polyorganosiloxane represented by the general formula (1) preferably has a number average molecular weight of 500 to 100,000 in terms of polystyrene standard substance.

[0015] With such an epoxy resin composition, the size of the structures that make up the island structures in the sea-island structure does not become too large, and microphase separation can be formed. Furthermore, by selecting the number average molecular weight within this range, the size of the island structures can be controlled.

[0016] In the present invention, the polyorganosiloxane represented by the general formula (1) preferably has an epoxy equivalent of 300 to 5,000 g / mol.

[0017] With such an epoxy resin composition, the size of the structures that make up the island structures in the sea-island structure does not become too large, and microphase separation can be formed. Furthermore, by selecting the epoxy equivalent within this range, the size of the island structures can be controlled.

[0018] In the present invention, it is also preferred that the component (B-1) contains hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in a total amount of 3,000 ppm or less.

[0019] By reducing these cyclic low-molecular-weight siloxanes, it is possible to avoid problems such as a decrease in adhesion due to the low-molecular-weight components bleeding out onto the surface of the cured product, and contamination of the surrounding environment due to the volatilization of the low-molecular-weight components.

[0020] In the present invention, it is preferable that the N—H bonds in the component (C-1) account for 30 to 70 mol % of the total N—H bonds in the components (C-1) and (C-2).

[0021] Such an epoxy resin composition is easy to handle because it does not undergo a crosslinking reaction or become a gel due to high molecular weight when preparing the prepolymer that is the component (B).

[0022] In the present invention, the component (C-1) is preferably a compound represented by the following general formula (I) or (II), or an aromatic polyamine. (In the formula, R's are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; R's are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms; and n represents the number of substituents, and is an integer of 0 to 4.)

[0023] Such an epoxy resin composition has good dispersibility of the prepolymerized component (B) in the component (A), and when cured, can provide sufficient strength and elongation.

[0024] In this case, the component (C-1) is preferably 4,4'-diaminodiphenylmethane.

[0025] In such an epoxy resin composition, the dispersibility of the prepolymerized component (B) in the component (A) is better, and when the composition is cured, it is possible to obtain more sufficient strength and elongation.

[0026] In the present invention, the component (C-2) is preferably represented by the following general formula (III) or (IV): (In the formula, each R is independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; each R" is independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; and n represents the number of substituents, and is an integer of 0 to 4.)

[0027] Such an epoxy resin composition can be sufficiently cured at a low temperature without impairing the dispersibility of component (B).

[0028] In this case, the component (C-2) is preferably selected from m-xylenediamine and its derivatives.

[0029] Such an epoxy resin composition can be sufficiently cured at a lower temperature without impairing the dispersibility of component (B).

[0030] In the present invention, it is preferable that the epoxy resin composition further contains a filler (D).

[0031] Such an epoxy resin composition can enhance the mechanical strength.

[0032] The present invention also provides a cured epoxy resin product obtained by curing the above-described epoxy resin composition.

[0033] Such an epoxy resin cured product can have improved elongation and tensile strength compared to conventional epoxy resin cured products, making the cured product tougher.

[0034] The present invention also provides an epoxy adhesive comprising the epoxy resin composition described above.

[0035] Such an epoxy adhesive can stably provide the desired properties.

[0036] As described above, when the epoxy resin composition of the present invention is used, the organosiloxane moieties in the prepolymer (component (B)) are incompatible with the epoxy resin (component (A)), resulting in the formation of a sea-island structure in which component (B) constitutes islands and component (A) constitutes the sea. The presence of urethane groups in component (B-1) in component (B) causes partial crystallization within the island components, resulting in the formation of a high-strength siloxane urethane polymer that would not be possible with siloxane alone. Furthermore, the urethane bonds in component (B) and the residues resulting from the reaction of epoxy groups in component (B-1) with some of the N—H bonds in component (C-1) have good affinity with the epoxy resin (component (A)), resulting in adequate compatibility at the interface between the island and sea regions. Furthermore, component (B), a constituent element of the epoxy resin composition of the present invention, is formed by reaction of epoxy groups in component (B-1) with some of the N—H groups in component (C-1). Because it contains amino groups derived from component (C-1), it also bonds with the epoxy resin (component (A)). As a result, in the state where a sea-island structure is formed, the island structures centered on component (B) are linked to component (A) of the sea structure to form an epoxy resin structure, which results in an epoxy resin composition that can increase both elongation properties and tensile shear strength compared to a case where component (B) is not present.

[0037] It is generally known that the curing temperature can be lowered by using an aromatic amine curing agent and an aliphatic amine curing agent in combination with an amine curing agent. However, it has been surprisingly found that the domain size of the island component can be controlled by the epoxy resin composition of the present invention, and both the elongation property and the tensile shear strength can be increased.

[0038] In this way, when the epoxy resin composition of the present invention is used, it is possible to increase both the elongation properties and the tensile shear strength of the cured product compared to a composition that does not contain the prepolymer as component (B).

[0039] The cured epoxy resin product of the present invention is obtained by curing the above-mentioned epoxy resin composition, and as described above, it is possible to obtain a cured product having both improved elongation properties and tensile shear strength compared to conventional cured epoxy resin products.

[0040] The epoxy resin composition of the present invention can also be used as an epoxy adhesive, which can provide a cured product having both improved elongation and tensile shear strength compared to conventional cured epoxy resin products.

[0041] As described above, there has been a need for the development of an epoxy resin composition having a composition that exhibits the properties of increasing both elongation properties and tensile shear strength, a cured product thereof, and an epoxy adhesive.

[0042] As a result of extensive research into the above-mentioned problems, the present inventors have found that an epoxy resin composition containing (A) an epoxy resin containing two or more epoxy groups in one molecule, (B) a prepolymer (B-1) a reaction product of a urethane bond-containing polyorganosiloxane and (C-1) a specific amount of an aromatic amine curing agent, and (C-2) a non-aromatic amine curing agent can increase both the elongation properties and the tensile shear strength, and have completed the present invention.

[0043] That is, the present invention provides an epoxy resin composition comprising: (A) an epoxy resin containing two or more epoxy groups in one molecule; (B) a prepolymer which is a reaction product of the following (B-1) and (C-1); (B-1) a urethane bond-containing polyorganosiloxane represented by the following general formula (1); (In the formula, R １ are each independently a group selected from an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms, or a hydroxyl group; X are each independently an alkylene group having 1 to 10 carbon atoms; Y are each independently a group selected from an alkylene group having 5 to 30 carbon atoms, an arylene group having 6 to 30 carbon atoms, and an aralkylene group having 7 to 30 carbon atoms; and Z are each independently an alkylene group having 1 to 20 carbon atoms, wherein the alkylene group in Y and Z may have one or more ether bonds in the molecular chain; n is an integer of 0 to 100; and m is 1 or 2.) An epoxy resin composition comprising: (C-1) an aromatic amine curing agent in an amount such that the number of N-H bonds in (C-1) is at least twice the number of epoxy groups in (B-1); and (C-2) a non-aromatic amine curing agent.

[0044] The present invention will be described in detail below, but the present invention is not limited thereto.

[0045] [Epoxy Resin Composition] The epoxy resin composition according to a first embodiment of the present invention comprises: (A) an epoxy resin containing two or more epoxy groups in one molecule; (B) a prepolymer that is a reaction product of the following (B-1) and (C-1); (B-1) a urethane bond-containing polyorganosiloxane having a specific structure; (C-1) a specific amount of an aromatic amine curing agent; and (C-2) a non-aromatic amine curing agent. Each component will be described in detail below.

[0046] [(A) Epoxy Resin] The epoxy resin (A) containing two or more epoxy groups per molecule in the epoxy resin composition of the present invention can be a known epoxy resin, and is not particularly limited as long as it is a resin other than the component (B-1) described below. Examples include bisphenol-type epoxy resins such as bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and bisphenol S-type epoxy resins; alicyclic epoxy resins such as dicyclopentadiene-type epoxy resins and 3,4-epoxycyclohexenylmethyl-3',4'-epoxycyclohexenecarboxylate; polyfunctional phenol-type epoxy resins such as resorcinol-type epoxy resins; stilbene-type epoxy resins, triazine-skeleton-containing epoxy resins, fluorene-skeleton-containing epoxy resins, triphenolalkane-type epoxy resins, biphenyl-type epoxy resins, xylylene-type epoxy resins, biphenylaralkyl-type epoxy resins, naphthalene-type epoxy resins, and diglycidyl ether compounds of polycyclic aromatics such as anthracene. These resins can be used alone or in combination of two or more. Preferably, the bisphenol-type epoxy resins are used.

[0047] The epoxy equivalent of the epoxy resin of component (A) is not particularly limited, but from the standpoint of the usable time after mixing and the strength of the cured product, it is preferably 50 to 5,000 g / eq, and more preferably 75 to 2,500 g / eq, calculated on a solid content basis.

[0048] The properties of the epoxy resin of component (A) are not particularly limited, but it is preferably liquid at 25°C, and more preferably has a viscosity of 10 to 100,000 mPa s, and even more preferably 20 to 50,000 mPa s. The viscosity is measured using a Brookfield rotational viscometer (B-type viscometer) as described in JIS K 7117-1:1999.

[0049] [(B) Prepolymer] The component (B) contained in the epoxy resin composition of the present invention takes the form of a prepolymer, which is a reaction product of a urethane bond-containing polyorganosiloxane of general formula (1) of the component (B-1) described below and an aromatic amine curing agent (C-1) described below. In this case, the ratio of the number of N-H bonds (molar number) in the aromatic amine curing agent (C-1) to the number of epoxy groups (molar number) in the urethane bond-containing polyorganosiloxane of general formula (1) of the component (B-1) is at least 2 times, preferably at least 4 times. If the amount is less than 2 times, the number of N-H bonds in the aromatic amine curing agent (C-1) in the molecule is small, resulting in an ultrahigh molecular weight product or a crosslinking reaction, resulting in a component that is difficult to handle and insoluble.

[0050] In the method for producing the prepolymer, for example, the prepolymer is obtained by reacting at 40 to 150° C. for 0.1 to 3 hours.

[0051] [(B-1) Urethane Bond-Containing Polyorganosiloxane] The urethane bond-containing polyorganosiloxane, which is the component (B-1) in the prepolymer (B) contained in the epoxy resin composition of the present invention, is a urethane bond-containing polyorganosiloxane represented by the following general formula (1): (In the formula, R １are each independently a group selected from an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms, or a hydroxyl group; Xs are each independently an alkylene group having 1 to 10 carbon atoms; Ys are each independently a group selected from an alkylene group having 5 to 30 carbon atoms, an arylene group having 6 to 30 carbon atoms, and an aralkylene group having 7 to 30 carbon atoms; Zs are each independently an alkylene group having 1 to 20 carbon atoms, and the alkylene group in Y and Z may have one or more ether bonds in the molecular chain; n is an integer of 0 to 100; and m is 1 or 2.

[0052] In the above general formula (1), R １ are each independently selected from an alkyl group having 1 to 12 carbon atoms, preferably 1 to 8 carbon atoms, an aryl group having 6 to 12 carbon atoms, preferably 6 to 9 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms, preferably 7 to 10 carbon atoms, or a hydroxyl group. Specific examples thereof include linear or branched alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cycloalkyl groups such as cyclohexyl; aryl groups such as phenyl and naphthyl; and aralkyl groups such as benzyl. Of these, a methyl group or a phenyl group is preferred.

[0053] In the above general formula (1), X's are each independently an alkylene group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms.

[0054] Specific examples of the alkylene group having 1 to 10 carbon atoms include a methylene group, an ethylene group, a propylene group, an n-hexylene group, an n-octylene group, etc. A methylene group is preferred.

[0055] In the above general formula (1), Y's are each independently a group selected from an alkylene group having 5 to 30 carbon atoms, an arylene group having 6 to 30 carbon atoms, and an aralkylene group having 7 to 30 carbon atoms.

[0056] The alkylene group having 5 to 30 carbon atoms may be linear, branched, or cyclic, and specific examples thereof include linear or branched alkylene groups such as an n-pentylene group, an n-hexylene group, an n-heptylene group, an n-octylene group, a 2-ethylhexylene group, an n-decylene group, an n-undecylene group, an n-dodecylene group, an n-tridecylene group, an n-tetradecylene group, an n-pentadecylene group, an n-hexadecylene group, an n-heptadecylene group, an n-octadecylene group, an n-nonadecylene group, and an n-eicosanylene group.

[0057] The alkylene group may have one or more ether bonds in the middle of the molecular chain. Specifically, it is a group containing an ether bond, such as a pentyleneoxy group, a hexyleneoxy group, or a heptyleneoxy group, and may have multiple ether bonds.

[0058] Examples of the arylene group having 6 to 30 carbon atoms include an o-phenylene group, an m-phenylene group, a p-phenylene group, a 3,5-tolylene group, a 2,4-tolylene group, a 2,6-tolylene group, a 1,2-naphthylene group, a 1,8-naphthylene group, a 2,3-naphthylene group, a 4,4'-biphenylene group, and a 4,4'-methylenebisphenyl group.

[0059] Examples of the aralkylene group having 7 to 30 carbon atoms include an o-xylylene group, an m-xylylene group, a p-xylylene group, and a 1,3-phenylenebis(2-propyl) group.

[0060] The above-mentioned Y is preferably exemplified by the following groups: The dotted line indicates the bonding site with the nitrogen atom of the urethane bond in the above general formula (1), and hydrogen atoms are conventionally omitted.

[0061] In the general formula (1), Z's are each independently an alkylene group having 1 to 20 carbon atoms, preferably 3 to 10 carbon atoms. The alkylene group having 1 to 20 carbon atoms may have one or more ether bonds interposed therein. A propylene group (-CH ２ CH ２ CH ２ -), ethyleneoxypropylene group (*-CH ２ CH ２ OCH ２CH ２ CH ２ -), where * indicates a bond with the oxygen atom of the urethane bond in the general formula (1).

[0062] In the above general formula (1), n ​​represents an integer of 0 to 100. Preferably, n is an integer of 0 to 60.

[0063] In the above general formula (1), m represents the average degree of polymerization, and is 1 or 2, preferably 1. If m is 3 or more, it is not preferable because a uniform cured product cannot be obtained.

[0064] In the urethane bond-containing polyorganosiloxane of the present invention represented by the general formula (1), the number average molecular weight, calculated as a polystyrene standard, is preferably 500 to 100,000, more preferably 500 to 50,000, and even more preferably 500 to 20,000. Within this range, the epoxy groups at both ends react with the curing agent, resulting in a molecular weight sufficient to obtain a cured product. Furthermore, the size of the structures constituting the island structures of the sea-island structure does not become too large, allowing for microphase separation to be formed. Furthermore, by selecting a number average molecular weight within this range, the size of the island structures can be controlled. The number average molecular weight refers to the number average molecular weight calculated as a polystyrene standard, as measured by gel permeation chromatography (GPC) under the following measurement conditions:

[0065] [Measurement conditions] Developing solvent: tetrahydrofuran (THF) Flow rate: 0.6 mL / min Detector: differential refractive index detector (RI) Column: TSK Guard column Super H-H TSKgel Super HM-N (6.0 mm I.D. × 15 cm × 1) TSKgel Super H2500 (6.0 mm I.D. × 15 cm × 1) (all manufactured by Tosoh Corporation) Column temperature: 40°C Sample injection volume: 50 μL (THF solution with a concentration of 0.3% by mass)

[0066] In the urethane bond-containing polyorganosiloxane of the present invention represented by the general formula (1), the epoxy equivalent (g / mol) is preferably 300 to 5,000 g / mol, more preferably 500 to 2,500 g / mol. This range provides a sufficient amount for the epoxy groups at both ends to react with the curing agent and produce a cured product with good physical properties. Furthermore, the size of the structures constituting the island structures of the sea-island structure does not become too large, allowing for the formation of microphase separation. Furthermore, by selecting an epoxy equivalent within this range, the size of the island structures can be controlled. The epoxy equivalent (g / mol) in the present invention can be calculated by adding hydrochloric acid to a predetermined mass of sample dissolved in 1,4-dioxane and back-titrating with aqueous sodium hydroxide solution.

[0067] Low molecular weight cyclic siloxanes are preferable because they can cause various problems such as contact failure. Component (B-1) preferably contains hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in a total amount of more than 0 ppm and not more than 3,000 ppm, more preferably 0.1 to 2,000 ppm, and even more preferably 0.1 to 1,000 ppm.

[0068] The amount of the low molecular weight cyclic siloxanes (D3 to D6) is a value determined by gas chromatography (GC) using a sample obtained by extracting and diluting component (B-1) with acetone. The term "greater than 0 ppm" refers to any peak detected by the above method, even if it is only a small amount.

[0069] In the present invention, the blending amount of component (B-1) is preferably 1 to 40 parts by mass, more preferably 10 to 30 parts by mass, and even more preferably 10 to 20 parts by mass, based on 100 parts by mass of component (A). When the blending amount of component (B-1) is 40 parts by mass or less, the strength of the cured epoxy resin is not reduced, and adhesive strength is sufficient. Furthermore, Tg is not reduced, and heat resistance is not reduced. Furthermore, when preparing the prepolymer (B), the ratio of the number of moles of N-H bonds in the aromatic amine curing agent (C-1) to the number of moles of epoxy groups in the urethane bond-containing polyorganosiloxane of general formula (1) of component (B-1) must be at least two times, so there is no risk of gelation or the like. On the other hand, when the blending amount is 1 part by mass or more, the desired effect of adding component (B-1) can be achieved.

[0070] [(C) Epoxy Resin Curing Agent] The epoxy resin curing agent (C) in the epoxy resin composition of the present invention can be any known curing agent capable of reacting with and curing an epoxy resin. This curing agent is added to cause a reactive functional group (amino group) in the curing agent molecule to react with the epoxy group in component (A) to form a cured product with a three-dimensional crosslinked structure.

[0071] The component (C) is an aromatic amine curing agent (C-1) and a non-aromatic amine curing agent (C-2). Of these, the component (C-1) is blended as a prepolymer (B), which is a reaction product with the component (B-1).

[0072] In the present invention, the term "aromatic amine" refers to an amine in which an amino group is directly bonded to an aromatic ring, and the term "non-aromatic amine" refers to an amine in which an amino group is bonded to an aromatic ring via an alkylene group, or an alicyclic amine.

[0073] [(C-1) Aromatic Amine Curing Agent] The (C-1) aromatic amine curing agent is preferably a compound represented by the following general formula (I) or the following general formula (II). (In the formula, R's are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; R's are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms; and n represents the number of substituents, and is an integer of 0 to 4.)

[0074] Specific examples of the aromatic amine curing agent (C-1) include aromatic diaminodiphenylmethane compounds such as 4,4'-diaminodiphenylmethane, 3,3'-diethyl-4,4'-diaminodiphenylmethane, 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane, 3,3',5,5'-tetraethyl-4,4'-diaminodiphenylmethane, 2,4-diaminotoluene, 1,4-diaminobenzene, 1,3-diaminobenzene, etc. These can be used alone or in combination of two or more.

[0075] Other aromatic amine curing agents that can be used include aromatic polyamines that are generally commercially available, such as Kayahard AA (Nippon Kayaku Co., Ltd.), jER Cure WA (Mitsubishi Chemical Corporation), Curehard MED-J, and Heart Cure 10 (Kumiai Chemical Industry Co., Ltd.).

[0076] More preferred are aromatic diaminodiphenylmethane compounds such as 4,4'-diaminodiphenylmethane.

[0077] [(C-2) Non-aromatic amine curing agent] The (C-2) non-aromatic amine curing agent is preferably a compound of the following general formula (III) or the following general formula (IV). (In the formula, each R is independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; each R" is independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; and n represents the number of substituents, and is an integer of 0 to 4.)

[0078] Examples of the non-aromatic amine curing agent (C-2) include those selected from m-xylenediamine and its derivatives. Other examples include bis(aminomethyl)benzene and 1,3-bisaminomethylcyclohexane. Of these, 1,3-bis(aminomethyl)benzene is preferred.

[0079] Of the total amount of N—H bonds in the components (C-1) and (C-2), the amount of N—H bonds in the component (C-1) is preferably 30 to 70 mol %, and more preferably 40 to 60 mol %. With such an epoxy resin composition, when preparing the prepolymer, which is the component (B), the composition does not become a gel due to a crosslinking reaction or high molecular weight, and is easy to handle.

[0080] [(D) Filler] The epoxy resin composition of the present invention may further contain a (D) filler. Examples of the (D) filler include silicas such as fused silica, crystalline silica, and cristobalite, and metal oxides such as aluminum oxide, titanium oxide, and magnesium oxide. These fillers may be used alone or in combination of two or more. Among these, silicas are preferred from the viewpoints of availability and quality stability. The amount of the (D) filler is preferably in the range of 1 to 25 parts by mass per 100 parts by mass of the total composition.

[0081] The average particle size is preferably 0.1 to 50 μm and can be selected depending on the application. The average particle size is a volume average particle size measured by laser diffraction.

[0082] The filler (D) is preferably surface-treated in advance with a coupling agent such as a silane coupling agent, although the amount of the coupling agent used for the surface treatment and the surface treatment method are not particularly limited.

[0083] [Other Components] Other additives may be added to the epoxy resin composition of the present invention as needed, such as reactive diluents, curing accelerators, flame retardants, ion trapping agents, antioxidants, adhesion promoters, colorants, and coupling agents.

[0084] [Method for Producing Epoxy Resin Composition] In the method for producing the epoxy resin composition of the present invention, for example, the epoxy resin composition can be obtained by simultaneously mixing, stirring, dissolving, and dispersing component (A), component (B), and component (C-2) while heating the components. Alternatively, the epoxy resin composition can be obtained by separately mixing, stirring, dissolving, and dispersing component (A), component (B), and component (C-2) while heating the components. Preferably, component (B-1) and component (C-1) are mixed, stirred, dissolved, and dispersed while heating the components to prepare a prepolymer, which is component (B), and then component (A) and component (C-2) are added simultaneously to obtain an epoxy resin composition in which component (B) is well dispersed. More preferably, the components (B-1) and (C-1) are mixed, stirred, dissolved, and dispersed while being heated to prepare a prepolymer, which is the component (B), and then the components (C-2) are mixed, stirred, dissolved, and dispersed, and thereafter the component (A) is added, thereby obtaining an epoxy resin composition in which the component (B) is well dispersed.

[0085] Component (D) and / or other additives may also be added as necessary. Component (D) may be added to components (A), (B), and (C-2), and mixed, stirred, dissolved, and dispersed while simultaneously or separately undergoing heat treatment. Alternatively, components (B) and (C-2) may be mixed, stirred, dissolved, and dispersed while undergoing heat treatment, and then component (D) and / or other additives may be added simultaneously with component (A).

[0086] [Cured Epoxy Resin Product] A second embodiment of the present invention is a cured epoxy resin product obtained by curing the epoxy resin composition described above. By placing the cured epoxy resin product in a mold appropriate for the application and curing and molding it, it can be provided as a highly tough cured product member for a variety of applications.

[0087] The curing conditions for the epoxy resin composition of the present invention are not particularly limited, but may be, for example, heating at a temperature of 60 to 200°C, preferably 80 to 180°C, for 30 minutes to 10 hours, preferably 1 to 5 hours. To efficiently carry out the reaction, the composition may be heated, for example, in two to five stages, from low to high temperatures for the above-mentioned time. Taking into consideration adhesion to the resin, more preferably, a cured product of sufficient strength can be obtained by heating at a temperature of 80 to 130°C for a predetermined time to prevent softening of the resin.

[0088] [Epoxy Adhesive] A third embodiment of the present invention is an epoxy adhesive comprising the epoxy resin composition described above.

[0089] The epoxy resin composition used in the above-mentioned epoxy adhesive is preferably mixed so that the ratio of the valence (number of moles) of the N—H bond in the components (C-1) and (C-2) to the total valence (number of moles) of the epoxy groups in the components (A) and (B-1) is 0.8 to 1.2, and more preferably mixed in equal amounts.

[0090] [Domains] As described above, the epoxy resin composition of the present invention has poor compatibility between the organosiloxane moieties in the prepolymer of component (B) and the epoxy resin of component (A), resulting in the formation of a sea-island structure in which component (B) forms islands and component (A) forms a sea. The island components of this sea-island structure are generally called domains, and controlling their amount and size can improve both the elongation and tensile shear strength of the cured epoxy resin. Unlike conventional methods, the epoxy resin composition of the present invention allows for the control of the domain size of component (B). The domain size is preferably 50 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less.

[0091] In the present invention, the domain size is measured by observing the cured epoxy resin product of the present invention with a scanning electron microscope. A measurement sample is coated with platinum to a thickness of 0.02 μm to prevent static buildup, and is fixed to a sample stage with conductive carbon double-sided tape. The domain size in the present invention is the average diameter of domains in an area of ​​35 × 47 μm observed at an acceleration voltage of 5 kV and a magnification of 2,000 times.

[0092] EXAMPLES The present invention will be specifically explained below using Examples, Comparative Examples, Synthesis Examples, and Comparative Synthesis Examples, but the present invention is not limited to these.

[0093] In the examples shown below, the epoxy resin (A) was a bisphenol A type epoxy resin manufactured by Mitsubishi Chemical Corporation under the trade name jER828EL (epoxy equivalent: 186 g / mol) (hereinafter referred to as DGEBA). The epoxy resin curing agent (C) was a (C-1) aromatic amine curing agent manufactured by Tokyo Chemical Industry Co., Ltd. under the trade name 4,4'-diaminodiphenylmethane (N-H equivalent: 49.6 g / mol) (hereinafter referred to as DDM). The non-aromatic amine curing agent (C-2) was a 1,3-bis(aminomethyl)benzene (N-H equivalent: 34.0 g / mol) (hereinafter referred to as mXDA). The urethane bond-containing polyorganosiloxane of the component (B-1) was synthesized by the method described in the following synthesis examples and comparative synthesis examples.

[0094] Synthesis Example 1 (m = 1) A 500 mL separable flask was charged with 91.95 g (0.827 mol NCO) of isophorone diisocyanate, and equipped with a mechanical stirrer, a stirring blade, a Dimroth reflux condenser, a nitrogen gas inlet, and a thermometer. Nitrogen gas was then allowed to flow through the flask. Next, 0.32 g (0.1% by mass) of K-KAT XK-640 (bismuth carboxylate, 18% bismuth content, manufactured by Kusumoto Chemicals Co., Ltd.) serving as a catalyst was added, and the internal temperature was raised to 60°C. Using a 300 mL dropping funnel, 200.00 g (0.413 mol OH, NCO / OH = 2.0) of 3-(2-hydroxyethoxy)propyldimethylsiloxy-terminated polydimethylsiloxane (n = 8, OH value 116 mg KOH / g) with D3 64 ppm, D4 59 ppm, D5 23 ppm, and D6 226 ppm was added over 30 minutes, and the mixture was then aged at 70°C for 3 hours. Subsequently, 30.80 g (0.415 mol) of glycidol was added, and the mixture was aged at 70°C for 2 hours, yielding 319.17 g of a colorless, slightly cloudy viscous liquid represented by the following formula: Since the NCO / OH ratio is 2.0, m is 1. Low molecular weight cyclic siloxanes were extracted with 10 mL of acetone using tetradecane as an internal standard per 1 g of sample, and then measured by GC. As a result, the total amount of D3 to D6 was 305 ppm (D3: 54 ppm, D4: 52 ppm, D5: 16 ppm, D6: 183 ppm). The epoxy equivalent was 758 g / mol.

[0095] Synthesis Example 2 (m = 2) A 500 mL separable flask was charged with 70.15 g (0.631 mol NCO) of isophorone diisocyanate, and equipped with a mechanical stirrer, a stirring blade, a Dimroth reflux condenser, a nitrogen gas inlet, and a thermometer. Nitrogen gas was then allowed to flow through the flask. Next, 0.25 g (0.1% by mass) of K-KAT XK-640 (bismuth carboxylate, 18% bismuth content, manufactured by Kusumoto Chemicals Co., Ltd.) serving as a catalyst was added, and the internal temperature was raised to 60°C. Using a 300 mL dropping funnel, 200.00 g (0.413 mol OH, NCO / OH = 1.5) of 3-(2-hydroxyethoxy)propyldimethylsiloxy-terminated polydimethylsiloxane (n = 8, OH value 116 mg KOH / g) with D3 64 ppm, D4 59 ppm, D5 23 ppm, and D6 226 ppm was added over 30 minutes, and the mixture was then aged at 70°C for 3 hours. Subsequently, 15.72 g (0.212 mol) of glycidol was added, and the mixture was aged at 70°C for 2 hours, yielding 277.05 g of a colorless, slightly cloudy viscous liquid represented by the following formula: Since the NCO / OH ratio is 1.5, m is 2. Low molecular weight cyclic siloxanes were extracted with 10 mL of hexane using tetradecane as an internal standard per 1 g of sample, and then measured by GC. As a result, the total amount of D3 to D6 was 339 ppm (D3: 60 ppm, D4: 55 ppm, D5: 18 ppm, D6: 206 ppm). The epoxy equivalent was 1093 g / mol.

[0096] Comparative Synthesis Example 1 (m = 3) A 500 mL separable flask was charged with 61.25 g (0.551 mol NCO) of isophorone diisocyanate, and equipped with a mechanical stirrer, a stirring blade, a Dimroth reflux condenser, a nitrogen gas inlet, and a thermometer. Nitrogen gas was then allowed to flow through the flask. Next, 0.26 g (0.1% by mass) of K-KAT XK-640 (bismuth carboxylate, 18% bismuth content, manufactured by Kusumoto Chemicals Co., Ltd.) serving as a catalyst was added, and the internal temperature was raised to 60°C. Using a 300 mL dropping funnel, 200.00 g (0.413 mol OH, NCO / OH = 1.33) of 3-(2-hydroxyethoxy)propyldimethylsiloxy-terminated polydimethylsiloxane (n = 8, OH value 116 mg KOH / g) with D3 64 ppm, D4 59 ppm, D5 23 ppm, and D6 226 ppm was added over 30 minutes, and the mixture was then aged at 70°C for 3 hours. Subsequently, 10.46 g (0.141 mol) of glycidol was added, and the mixture was aged at 70°C for 2 hours, yielding 266.50 g of a colorless, slightly cloudy viscous liquid represented by the following formula: Since the NCO / OH ratio is 1.33, m is 3. Low molecular weight cyclic siloxanes were extracted with 10 mL of hexane using tetradecane as an internal standard per 1 g of sample, and then measured by GC. As a result, the total amount of D3 to D6 was 348 ppm (D3: 62 ppm, D4: 58 ppm, D5: 18 ppm, D6: 210 ppm). The epoxy equivalent was 2180 g / mol.

[0097] The compositions of the examples and comparative examples were prepared using the above materials, and the aluminum cups containing the compositions were heated and cured in a thermostatic chamber at 100°C for 2 hours, and at 110°C, 120°C, and 130°C for 30 minutes each in four stages, and the following evaluations were carried out. The temperature rise rate was 5°C / min.

[0098] [Domain size measurement] The cured product obtained above was measured under the following conditions, and the observation results are shown in Table 1. (Measurement conditions) Measurement sample: Platinum was vapor-deposited to a film thickness of 0.02 μm to prevent static buildup, and the sample was fixed to a sample stage with conductive carbon double-sided tape. Measurement equipment: Field emission scanning electron microscope (JSM-6700F, manufactured by JEOL Ltd.) Ion sputtering device (JFC-1500, manufactured by JEOL Ltd.) Magnification: 2,000x Acceleration voltage: 5 kV

[0099] [Glass transition temperature (Tg)] The cured product obtained above was cut into test pieces measuring 30 mm in length, 4.0 mm in width, and 0.40 mm in thickness, and measured using a Rheogel-E40000 manufactured by UBM under the following conditions: temperature range of -150 to 250°C, sinusoidal wave, heating rate of 2.5°C / min, tensile mode, and frequency of 10 Hz. The peak top of the loss tangent (tan δ), which is the loss modulus (G") / storage modulus (G'), was taken as Tg (°C). The results are shown in Table 1.

[0100] [Tensile Shear Adhesion Test] The adherend was immersed in acetone and ultrasonically cleaned for 30 minutes. Next, the adherend was polished with an electric sander equipped with #240 abrasive paper to remove the surface oxide film, and then immersed in acetone and ultrasonically cleaned for 30 minutes twice. A backing plate (length 25 mm x width 25 mm x thickness 1.6 mm) was then attached to the adherend at a position 62.5 mm from the edge. The composition prepared in each example and comparative example was then applied to the adherend up to 12.5 mm from the edge, and another adherend was placed on top of it. The test piece was heated at 120°C and 5 MPa for 2 hours using a hot press. A weight (weight: 1700 g, pressure: 960 Pa) was then placed on the test piece in a thermostatic chamber and heated at 100°C for 2 hours, and at 110°C, 120°C, and 130°C for 30 minutes each to prepare a test piece. The heating rate was 5°C / min. After gradual cooling, the test pieces were removed, and any resin protruding from the joint was removed with a cutter knife. The test pieces were subjected to a tensile shear adhesion test using a Shimadzu AGS-X at a head speed of 50 mm / min. The tensile shear strength and elongation at break were averaged values ​​of N=5. The results are shown in Table 1.

[0101] [Example 1] DDM (0.206 g, 4.15 mmol N-H) as component (C-1) and polyorganosiloxane (0.15 g, 0.20 mmol epoxy) from Synthesis Example 1 as component (B-1) were separately heated and melted, then added to an aluminum cup and stirred on a hot plate at 100 ° C for 25 minutes to prepare a prepolymer (N-H / epoxy = 20.99). Next, degassed DGEBA (1.50 g, 8.06 mmol epoxy) as component (A) was placed in a separate aluminum cup and heated and melted on a hot plate at 100 ° C to reduce viscosity. This melted DGEBA and mXDA (0.141 g, 4.15 mmol N-H) as component (C-2) were sequentially added to the aluminum cup containing the prepolymer and heated and stirred for 2 minutes to prepare a composition (N-H / epoxy = 1.00). The compositions thus obtained were then subjected to the above-described evaluations. The evaluation results are shown in Table 1.

[0102] [Examples 2 to 4] As the component (C-1), DDM having an N-H equivalent of 0.5 chemical equivalents relative to the total epoxy group amount of the epoxy group-containing compound (component (A) and component (B-1)), and the polyorganosiloxane of Synthesis Example 1 as the component (B-1) were separately heated and melted in the amounts shown in Table 1, added to an aluminum cup, and stirred on a hot plate at 100 ° C for 25 minutes to prepare a prepolymer. Next, as the component (A), the amount of degassed DGEBA shown in Table 1 was placed in a separate aluminum cup and heated on a hot plate at 100 ° C for the purpose of reducing the viscosity. Thereafter, as the component (C-2), mXDA having an N-H equivalent of 0.5 chemical equivalents relative to the total remaining epoxy group amount was added to the aluminum cup containing the prepolymer in the amount shown in Table 1, and heated and stirred for 2 minutes. Furthermore, the DGEBA previously melted by heating was added to this mixture, and the mixture was heated and stirred for 2 minutes to prepare a composition. The resulting compositions were then evaluated as described above. The evaluation results are shown in Table 1. The N-H equivalent of component (C-1) relative to the amount of epoxy groups in component (B-1) (N-H / epoxy) was 41.36 in Example 2, 20.99 in Example 3, and 10.75 in Example 4.

[0103] [Comparative Example 1] As the component (B-1), the polyorganosiloxane compound (0.15 g) of Synthesis Example 1 was used, and as the component (C-1), DDM (0.41 g) having an N-H equivalent of 1.0 chemical equivalent relative to the total epoxy group amount of the epoxy group-containing compound (component (A) and component (B-1)) was used. These were separately heated and melted, then added to an aluminum cup, and stirred on a hot plate at 140 ° C for 15 minutes to prepare a prepolymer. Subsequently, as the component (A), degassed DGEBA (1.50 g) was placed in another aluminum cup and heated on a hot plate at 140 ° C for the purpose of reducing viscosity. This DGEBA was added to the aluminum cup containing the prepolymer and heated and stirred for 2 minutes to prepare a composition. Thereafter, since the obtained composition could not be cured under the same conditions as in the examples, it was heated at 150 ° C for 2 hours, and then further heated at 180 ° C for 2 hours to prepare a curing condition. The heating rate was 5 ° C / min. The evaluation results are shown in Table 1.

[0104] [Comparative Example 2] Degassed DGEBA (1.50 g) as component (A) and the polyorganosiloxane compound (0.30 g) of Synthesis Example 1 as component (B-1) were placed in an aluminum cup and heated on a hot plate at 130 ° C. to reduce viscosity. Subsequently, DDM (0.42 g) having an N-H equivalent of 1.0 chemical equivalent relative to the total epoxy group amount of the epoxy group-containing compounds (A) and (B-1) as component (C-1) was placed in another aluminum cup and completely melted while stirring on a hot plate at the same temperature. This DDM was added to the aluminum cup containing DGEBA and the polyorganosiloxane compound of Synthesis Example 1 and stirred for 5 minutes to prepare a composition. Thereafter, since a cured product could not be obtained under the same conditions as in the examples, the resulting composition was heated at 150 ° C. for 2 hours, and then further heated at 180 ° C. for 2 hours as curing conditions. The heating rate was 5 ° C. / min. The evaluation results are shown in Table 1.

[0105] [Comparative Example 3] As component (A), degassed DGEBA (1.50 g) was placed in an aluminum cup and heated on a hot plate at 100 ° C. to reduce viscosity. Subsequently, as component (C-2), mXDA (0.274 g) having an N—H equivalent of 1.0 chemical equivalent relative to the total epoxy group amount of the epoxy group-containing compound (component (A))) was placed in a separate aluminum cup and completely melted while stirring on a hot plate at 130 ° C. The mXDA was then added to the aluminum cup containing the DGEBA and stirred for 5 minutes to prepare a composition. Subsequently, adhesive test specimens were prepared under the same conditions as in the examples, and the tensile shear strength was measured. The result was 10 MPa or less, and it was determined that this composition had insufficient strength. Therefore, other evaluation items were not performed.

[0106] [Comparative Example 4] As the component (B-1), the polyorganosiloxane compound (0.15 g) of Comparative Synthesis Example 1, and as the component (C-1), DDM (0.206 g) having an N-H equivalent of 0.5 chemical equivalents relative to the total epoxy group amount of the epoxy group-containing compound that is the component (A) and the component (B-1) were separately heated and melted, and then added to an aluminum cup and stirred for 25 minutes on a hot plate at 100 ° C. to prepare a prepolymer. Subsequently, as the component (A), degassed DGEBA was placed in a separate aluminum cup and heated on a hot plate at 100 ° C. for the purpose of reducing the viscosity. This DGEBA (1.50 g) and mXDA (0.141 g), which served as component (C-2) and had an N—H equivalent of 0.5 chemical equivalents relative to the total epoxy group amount of the epoxy group-containing compounds (components (A) and (B-1)), were added sequentially to the aluminum cup containing the prepolymer, and the mixture was heated and stirred for 2 minutes to prepare a composition. A cured product was then prepared from the resulting composition under the same conditions as in the Examples. As a result, the resulting cured product had separated into island components of a sea-island structure that were visible from the outside, and a uniform cured product was not obtained. Therefore, further evaluations were not performed.

[0107] Comparative Example 5: As component (C-1), DDM (0.201 g, 4.05 mmol N-H) was separately heated and melted, then added to an aluminum cup and stirred on a hot plate at 100°C for 25 minutes. Subsequently, as component (A), degassed DGEBA (1.50 g, 8.06 mmol epoxy) was placed in another aluminum cup and heated on a hot plate at 100°C to reduce viscosity. This DGEBA and mXDA (0.138 g, 4.06 mmol N-H) as component (C-2) were sequentially added to the aluminum cup containing DDM and heated and stirred for 2 minutes to prepare a composition. The resulting composition was then evaluated under the same conditions as in the Examples. The evaluation results are shown in Table 1.

[0108] The evaluation results of the examples and comparative examples are shown in Table 1.

[0109] Despite the low curing temperature, all Examples showed increased strength and elongation in tensile shear adhesion tests compared to Comparative Examples. Furthermore, Comparative Examples 1 and 2, which did not contain component (C-2), failed to produce cured products under the curing conditions of the Examples, requiring higher temperature curing conditions. Comparative Example 3, which did not contain component (B), exhibited insufficient tensile shear strength. Comparative Example 4, which did not contain a specific urethane bond-containing polyorganosiloxane as component (B-1) in the component (B), exhibited insufficient tensile shear strength in the cured product, with the island components of the sea-island structure separated into sizes visible by appearance, preventing the production of a uniform cured product. Comparative Example 5, which did not contain component (B-1), failed to produce domains, resulting in poor tensile shear strength and elongation at break.

[0110] This confirmed that the epoxy resin composition of the present invention, its cured product, and epoxy adhesive exhibit the properties of increasing both elongation and tensile shear strength even when the curing temperature is lowered while controlling the domain size.

[0111] The present specification includes the following aspects: [1]: An epoxy resin composition comprising: (A) an epoxy resin containing two or more epoxy groups in one molecule; (B) a prepolymer which is a reaction product of the following (B-1) and (C-1); (B-1) a urethane bond-containing polyorganosiloxane represented by the following general formula (1); (In the formula, R １are each independently a group selected from an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms, or a hydroxyl group; X are each independently an alkylene group having 1 to 10 carbon atoms; Y are each independently a group selected from an alkylene group having 5 to 30 carbon atoms, an arylene group having 6 to 30 carbon atoms, and an aralkylene group having 7 to 30 carbon atoms; and Z are each independently an alkylene group having 1 to 20 carbon atoms, wherein the alkylene group in Y and Z may have one or more ether bonds in the molecular chain; n is an integer of 0 to 100; and m is 1 or 2.) An epoxy resin composition comprising: (C-1) an aromatic amine curing agent in an amount such that the number of N-H bonds in (C-1) is at least twice the number of epoxy groups in (B-1); and (C-2) a non-aromatic amine curing agent. [2]: The epoxy resin composition of [1] above, wherein component (A) is a bisphenol-type epoxy resin. [3]: The epoxy resin composition of [1] above, wherein the polyorganosiloxane represented by general formula (1) has a number-average molecular weight of 500 to 100,000, calculated as a polystyrene standard, of 500 to 100,000. [4]: ​​The epoxy resin composition of any one of [1] to [3] above, wherein the polyorganosiloxane represented by general formula (1) has an epoxy equivalent of 300 to 5,000 g / mol. [5]: The epoxy resin composition of any one of [1] to [4] above, wherein component (B-1) contains hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in a total amount of 3,000 ppm or less. [6]: The epoxy resin composition of any one of [1] to [5] above, wherein the N-H bonds in component (C-1) account for 30 to 70 mol % of the total amount of N-H bonds in components (C-1) and (C-2). [7]: The epoxy resin composition of any one of [1] to [6] above, wherein component (C-1) is an amine represented by the following general formula (I) or (II), or an aromatic polyamine: (In the formula, R are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; R' are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms; and n represents the number of substituents, and is an integer of 0 to 4.) [8]: The epoxy resin composition of [7] above, wherein the component (C-1) is 4,4'-diaminodiphenylmethane. [9]: The epoxy resin composition of any one of [1] to [8] above, wherein the component (C-2) is represented by the following general formula (III) or general formula (IV): (In the formula, R are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; R" are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; n represents the number of substituents, and is an integer of 0 to 4.)

[10] : The epoxy resin composition of [9] above, wherein the component (C-2) is selected from m-xylenediamine and derivatives thereof.

[11] : The epoxy resin composition of any one of [1] to

[10] above, wherein the epoxy resin composition further contains (D) a filler.

[12] : An epoxy resin cured product, which is obtained by curing the epoxy resin composition of any one of [1] to

[11] above.

[13] : An epoxy adhesive, which comprises the epoxy resin composition of any one of [1] to

[11] above.

[0112] The present invention is not limited to the above-described embodiments, which are merely examples, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and that provides similar effects is included within the technical scope of the present invention.

Claims

1. An epoxy resin composition comprising: (A) an epoxy resin containing two or more epoxy groups in one molecule; (B) a prepolymer which is a reaction product of the following (B-1) and (C-1); (B-1) a urethane bond-containing polyorganosiloxane represented by the following general formula (1); (In the formula, R １ are each independently a group selected from an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms, or a hydroxyl group; X are each independently an alkylene group having 1 to 10 carbon atoms; Y are each independently a group selected from an alkylene group having 5 to 30 carbon atoms, an arylene group having 6 to 30 carbon atoms, and an aralkylene group having 7 to 30 carbon atoms; and Z are each independently an alkylene group having 1 to 20 carbon atoms, wherein the alkylene group in Y and Z may have one or more ether bonds in the molecular chain; n is an integer of 0 to 100, and m is 1 or 2.) An epoxy resin composition comprising: (C-1) an aromatic amine curing agent in an amount such that the number of N-H bonds in (C-1) is at least twice the number of epoxy groups in (B-1); and (C-2) a non-aromatic amine curing agent.

2. The epoxy resin composition according to claim 1, wherein component (A) is a bisphenol-type epoxy resin.

3. The epoxy resin composition according to claim 1, wherein the polyorganosiloxane represented by the general formula (1) has a number average molecular weight of 500 to 100,000 in terms of polystyrene standard substance.

4. The epoxy resin composition according to claim 1, characterized in that the polyorganosiloxane represented by the general formula (1) has an epoxy equivalent of 300 to 5,000 g / mol.

5. The epoxy resin composition according to claim 1, wherein the component (B-1) contains hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in a total amount of 3,000 ppm or less.

6. The epoxy resin composition according to claim 1, wherein the N-H bonds in component (C-1) account for 30 to 70 mol % of the total N-H bonds in components (C-1) and (C-2).

7. The epoxy resin composition according to claim 1, wherein the component (C-1) is a compound represented by the following general formula (I) or (II), or an aromatic polyamine: (In the formula, R's are each independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; R's are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms; and n represents the number of substituents, and is an integer of 0 to 4.) 8. The epoxy resin composition according to claim 7, wherein the component (C-1) is 4,4'-diaminodiphenylmethane.

9. The epoxy resin composition according to claim 1, wherein the component (C-2) is represented by the following general formula (III) or (IV): (In the formula, each R is independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; each R" is independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; and n represents the number of substituents, and n is an integer of 0 to 4.) 10. The epoxy resin composition according to claim 9, wherein the component (C-2) is selected from m-xylenediamine and its derivatives.

11. The epoxy resin composition according to claim 1, further comprising (D) a filler.

12. A cured epoxy resin product, characterized in that the epoxy resin composition according to any one of claims 1 to 11 is cured.

13. An epoxy adhesive comprising the epoxy resin composition according to any one of claims 1 to 11.

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