Epoxy resin composition, sealing material, semiconductor sealing material, adhesive, camera module, semiconductor package, and electronic apparatus

Abstract

An epoxy resin composition according to the present invention contains an epoxy resin (A) and a curing agent (B), wherein the curing agent (B) is such that when the total amine value is denoted by (a) and the tertiary amine value is denoted by (b), (a) and (b) satisfy relational expression (1).　(1): (a) - (b) ≥ 5.0

Description

Epoxy resin composition, encapsulant, semiconductor encapsulant, adhesive, camera module, semiconductor package, and electronic device

[0001] The present invention relates to an epoxy resin composition, an encapsulant, a semiconductor encapsulant, an adhesive, a camera module, a semiconductor package, and an electronic device.

[0002] Epoxy resin compositions have been widely used in a variety of applications due to their excellent heat resistance and chemical resistance. In particular, in recent years, there has been an increasing demand for adhesive bonding of components with low heat resistance, such as lenses and displays, and there is a demand for epoxy resin compositions that cure quickly and have high adhesive strength even under low-temperature conditions, for example, at temperatures of about 100°C or less.

[0003] It is generally known that the curing temperature range of an epoxy resin composition varies depending on the type of curing agent used. For example, many amine-based curing agents having a primary amino group or a secondary amino group in one molecule react with an epoxy group at relatively low temperatures, but some react at around room temperature. For example, Patent Document 1 discloses a technique for preparing an epoxy resin composition that can be cured at room temperature using an epoxy resin curing agent having a primary amino group and a secondary amino group in one molecule.

[0004] Japanese Patent Application Laid-Open No. 2006-070125

[0005] However, although the epoxy resin composition disclosed in Patent Document 1, which uses an epoxy resin curing agent having a primary amino group and a secondary amino group in one molecule, showed a certain effect on reactivity under low temperature conditions, it was found that the adhesive strength of a cured product cured under low temperature conditions of about 80° C. decreased after storage in a humid and hot environment. Therefore, there is a problem in that there is room for improvement in terms of moist and heat resistance after curing under low temperature conditions.

[0006] In view of the above-mentioned problems, the present invention aims to provide an epoxy resin composition that exhibits excellent adhesive strength even when cured under low-temperature conditions and that shows only a small decrease in adhesive strength even after storage in a humid and hot environment.

[0007] As a result of extensive research into solving the above-mentioned problems, the present inventors have found that in an epoxy resin composition containing an epoxy resin and curing agent particles, the above-mentioned problems of the conventional art can be solved by ensuring that the total amine value and the tertiary amine value in the curing agent particles satisfy a specific relationship, and have thus completed the present invention.

[0008] [1] An epoxy resin composition comprising an epoxy resin (A) and a curing agent (B), wherein the curing agent (B) has a total amine value (a) and a tertiary amine value (b), and the values ​​of (a) and (b) satisfy the following relational expression (1): (a) - (b) ≧ 5.0 (1) [2] The epoxy resin composition according to [1], wherein the curing agent (B) has a light transmittance of 50.0% or more at a wavelength of 365 nm as measured by ultraviolet-visible spectroscopy when dissolved in a 1.0 mass% dimethylformamide (DMF) solution. [3] The epoxy resin composition according to [1] or [2], wherein the viscosity of the epoxy resin composition is 10.0 Pa s or more and 800.0 Pa s or less at 25°C. [4] The epoxy resin composition according to any one of [1] to [3] above, wherein the curing agent (B) comprises at least one reaction product of an epoxy resin (C) and an amine compound (D). [5] The epoxy resin composition according to [4] above, wherein the amine compound (D) is an aromatic amine compound or an alicyclic amine compound. [6] The epoxy resin composition according to [4] above, wherein the amine compound (D) is an alicyclic amine compound. [7] The epoxy resin composition according to any one of [1] to [6] above, wherein the curing agent (B) is curing agent particles. [8] An epoxy resin composition comprising an epoxy resin (A) and curing agent particles (B-1), wherein the curing agent particles (B-1) have a total amine value (a) and a tertiary amine value (b), and the values ​​of (a) and (b) satisfy the following relational expression (1): (a) - (b) ≧ 5.0 (1). The curing agent particles (B-1) contain at least one reaction product of an epoxy resin (C) and an alicyclic amine compound (D), and a 1.0 mass % solution of the curing agent particles (B-1) in dimethylformamide (DMF) has a light transmittance of 50.0% or more at a wavelength of 365 nm as measured by ultraviolet-visible spectroscopy. [9] The epoxy resin composition according to any one of [1] to [8], wherein the curing agent (B) satisfies the following conditions (i) to (iii): (i) curing agent particles.(ii) When prepared as a 1.0% by mass dimethylformamide (DMF) solution, the light transmittance at a wavelength of 365 nm measured by ultraviolet-visible spectroscopy is 50.0% or more. (iii) The epoxy resin composition contains at least one reaction product of an epoxy resin (C) and an amine compound (D), and the amine compound (D) is an alicyclic amine.

[10] The epoxy resin composition according to any one of items [4] to [9] above, wherein the amine compound (D) is 1,3-bis(aminomethyl)cyclohexane.

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

[10] above, wherein the curing agent (B) satisfies the following conditions (i), (ii), and (iv): (i) the curing agent is a particle. (ii) When prepared as a 1.0% by mass dimethylformamide (DMF) solution, the light transmittance at a wavelength of 360 nm measured by ultraviolet-visible spectroscopy is 50.0% or more. (iv) The epoxy resin composition contains at least one reaction product of an epoxy resin (C) and an amine compound (D), and the amine compound (D) is 1,3-bis(aminomethyl)cyclohexane.

[12] The epoxy resin composition according to any one of [4] to

[11] , wherein the content of the amine compound (D) in the curing agent (B) is 0.000001% by mass or more and 3.0% by mass or less.

[13] The specific surface area value of the curing agent (B) which is the curing agent particle is (Y) (m. ２ The epoxy resin composition according to any one of [7] to

[12] above, wherein the values ​​of (X) and (Y) satisfy the following relational expression (2), where (X) is the particle diameter D50 at an undersize cumulative fraction of 50% and (X) is the particle diameter D50 at an undersize cumulative fraction of 50% (μm): 4.0(X) -１ ≦(Y) ≦8.3(X) -１...(2)

[14] The epoxy resin composition according to any one of [1] to

[13] , wherein the content of the curing agent (B) in the epoxy resin composition is 5.0 mass % or more and 65.0 mass % or less based on the total amount of the epoxy resin (A) and the curing agent (B).

[15] The epoxy resin composition according to any one of [7] to

[14] , wherein the curing agent (B) in the form of curing agent particles is a capsule-type curing agent in which the surface of a core particle is covered with a shell.

[16] The epoxy resin composition according to any one of [1] to

[15] , wherein the curing agent (B) satisfies the following conditions (i), (ii), (iv), and (v): (i) it is a curing agent particle; (ii) when prepared as a 1.0 mass % dimethylformamide (DMF) solution, the light transmittance at a wavelength of 365 nm by ultraviolet-visible spectroscopy is 50.0% or more. (iv) The curing agent comprises at least one reaction product of an epoxy resin (C) and an amine compound (D), wherein the amine compound (D) is 1,3-bis(aminomethyl)cyclohexane. (v) The curing agent is a capsule-type curing agent in which the surfaces of core particles are covered with a shell.

[17] The epoxy resin composition according to any one of [1] to

[16] , wherein the total calorific value of the epoxy resin composition measured by a differential scanning calorimeter (DSC) is (c), and the total calorific value of a cured product obtained by curing the epoxy resin composition at 80°C for 60 minutes measured by a differential scanning calorimeter (DSC) is (d), the values ​​of (c) and (d) satisfy the following relational expression (3): (d) / (c)×100≦20.0 (3)

[18] The epoxy resin composition according to any one of [1] to

[17] , wherein the curing agent (B) comprises a low-molecular-weight amine compound (E) having a tertiary amino group and a molecular weight of 1,000 or less.

[19] The epoxy resin composition according to

[18] above, wherein the low molecular weight amine compound (E) having a tertiary amino group is 1,4-diazabicyclo[2.2.2]octane or (1,4-diazabicyclo[2.2.2]octan-2-yl)methanol.

[20] The epoxy resin composition according to any one of [1] to

[19] above, further comprising a thiol compound (F).

[21] An encapsulant comprising the epoxy resin composition according to any one of [1] to

[20] above.

[22] An adhesive comprising the epoxy resin composition according to any one of [1] to

[20] above.

[23] A camera module comprising the epoxy resin composition according to any one of [1] to

[20] above.

[24] A semiconductor package comprising the epoxy resin composition according to any one of [1] to

[20] above.

[25] An electronic device comprising the epoxy resin composition according to any one of [1] to

[20] above.

[0009] According to the present invention, an epoxy resin composition can be provided which exhibits excellent adhesive strength even when cured under low-temperature conditions and in which the extent of deterioration in adhesive strength is small even after storage in a humid and hot environment.

[0010] Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. The following present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be carried out by appropriately modifying it within the scope of its gist.

[0011] [Epoxy Resin Composition] The epoxy resin composition of this embodiment contains an epoxy resin (A) and a curing agent (B), and when the total amine value of the curing agent (B) is (a) and the tertiary amine value is (b), the values ​​of (a) and (b) satisfy the following relational expression (1): (a) - (b) ≧ 5.0 (1)

[0012] According to the above-mentioned configuration, it is possible to provide an epoxy resin composition that exhibits excellent adhesive strength even when cured under low-temperature conditions, and that exhibits little deterioration in adhesive strength even after storage in a humid and hot environment.

[0013] The viscosity of the epoxy resin composition of this embodiment is preferably 10.0 Pa·s or more and 800.0 Pa·s or less. When the epoxy resin composition of this embodiment has a viscosity of 10.0 Pa·s or more, dripping tends to be more easily suppressed when the epoxy resin composition of this embodiment is applied to an adherend. Furthermore, when the epoxy resin composition of this embodiment has a viscosity of 800.0 Pa·s or less, the epoxy resin composition of this embodiment is more easily applied to an adherend, and the adhesive strength of the steel plate tends to be more easily controlled. The lower limit of the viscosity of the epoxy resin composition of this embodiment is more preferably 30.0 Pa·s or more, and even more preferably 50.0 Pa·s or more. The upper limit of the viscosity of the epoxy resin composition of this embodiment is more preferably 700 Pa·s or less, and even more preferably 600 Pa·s or less. The viscosity of the epoxy resin composition can be measured by the method described in the Examples below, and can be controlled within the above-mentioned numerical range by changing the types of epoxy resin and curing agent.

[0014] In the epoxy resin composition of the present embodiment, when the total calorific value measured by a differential scanning calorimeter (DSC) is (c) and the total calorific value measured by a differential scanning calorimeter (DSC) of a cured product obtained by curing the epoxy resin composition at 80°C for 60 minutes is (d), the values ​​of (c) and (d) preferably satisfy the following relational expression (3): (d) / (c)×100≦20.0 (3)

[0015] By satisfying the above-mentioned relational expression (3), the epoxy resin composition of this embodiment can provide an epoxy resin composition that exhibits excellent adhesive strength even when cured under low-temperature conditions and exhibits little decrease in adhesive strength even after storage in a humid and hot environment. The reason for this is considered as follows. The adhesive strength of an epoxy resin composition is correlated with the degree of reaction progress between the epoxy resin and the curing agent after thermal curing, and adhesive strength tends to increase as the reaction progresses. The value of (d) / (c)×100 in the above-mentioned relational expression (3) is an index indicating the amount of unreacted epoxy resin (A) and curing agent (B). A value of (d) / (c)×100 of 20.0 or less indicates that the amount of unreacted epoxy resin and curing agent is small, and practically sufficient adhesive strength can be obtained. Therefore, it is preferable that the epoxy resin composition satisfy the above-mentioned relational expression (3). From the viewpoint of the adhesive strength of the epoxy resin composition of this embodiment, the value of (d) / (c)×100 is preferably 10.0 or less, more preferably 5.0 or less, and even more preferably 2.0 or less. Examples of methods for controlling the value of (d) / (c)×100 include a method in which the curing agent (B) is made into particles and the surfaces of the particles are coated with a shell, a method in which a material with a different composition is attached to the particle surfaces, and a method in which the type of material constituting the curing agent particles is adjusted to increase the reactivity.

[0016] (Epoxy Resin (A)) The epoxy resin composition of the present embodiment contains an epoxy resin (A). As the epoxy resin (A), a conventionally known epoxy resin can be used, and examples thereof include, but are not limited to, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AD ​​type epoxy resins, bisphenol M type epoxy resins, bisphenol P type epoxy resins, tetrabromobisphenol A type epoxy resins, biphenyl type epoxy resins, tetramethylbiphenyl type epoxy resins, tetrabromobiphenyl type epoxy resins, diphenyl ether type epoxy resins, benzophenone type epoxy resins, phenyl benzoate type epoxy resins, diphenyl sulfide type epoxy resins, diphenyl sulfoxide type epoxy resins, diphenyl sulfone type epoxy resins, diphenyl disulfide type epoxy resins, naphthalene type epoxy resins, anthracene type epoxy resins, and hydroquinone type epoxy resins. Examples of suitable epoxy resins include bifunctional epoxy resins such as epoxide resins, methylhydroquinone-type epoxy resins, dibutylhydroquinone-type epoxy resins, resorcinol-type epoxy resins, methylresorcinol-type epoxy resins, and catechol-type epoxy resins; trifunctional epoxy resins such as N,N-diglycidylaminobenzene-type epoxy resins and triazine-type epoxy resins; tetrafunctional epoxy resins such as tetraglycidyldiaminodiphenylmethane-type epoxy resins and diaminobenzene-type epoxy resins; multifunctional epoxy resins such as phenol novolac-type epoxy resins, cresol novolac-type epoxy resins, triphenylmethane-type epoxy resins, tetraphenylethane-type epoxy resins, dicyclopentadiene-type epoxy resins, naphthol aralkyl-type epoxy resins, and brominated phenol novolac-type epoxy resins; and alicyclic epoxy resins. These may be used alone or in combination of two or more. As the epoxy resin (A), epoxy resins modified with isocyanates or the like may also be used in combination.

[0017] The epoxy resin composition of this embodiment preferably contains a bisphenol-type epoxy resin as the epoxy resin (A) from the viewpoints of handleability and heat resistance, more preferably a bisphenol F-type epoxy resin from the viewpoint of imparting storage stability and good reactivity, and even more preferably a bisphenol A-type epoxy resin from the viewpoint of imparting sufficient mechanical properties. Furthermore, by including a bisphenol A-type epoxy resin in addition to a bisphenol F-type epoxy resin, even better storage stability and good reactivity are exhibited. The mechanism behind this is thought to be as follows, although it is not intended to be limiting. The inclusion of a bisphenol A-type epoxy resin suppresses aggregation between the bisphenol F-type epoxy resins, thereby improving the uniformity and storage stability of the epoxy resin composition of this embodiment, and also improving reactivity by increasing molecular diffusivity after the start of curing.

[0018] From the viewpoint of obtaining an epoxy resin composition that has excellent electrical properties and an excellent balance between curability and storage stability, the total chlorine content in the epoxy resin (A) is preferably 2500 ppm or less, more preferably 1500 ppm or less, and even more preferably 900 ppm or less.

[0019] Furthermore, the total chlorine content in the epoxy resin (A) is preferably 0.01 ppm or more, more preferably 0.1 ppm or more, and even more preferably 0.5 ppm or more, from the viewpoint of achieving a predetermined technical significance, for example, practically satisfactory manufacturability. Here, the total chlorine content refers to the total amount of organic and inorganic chlorine contained in the epoxy resin (A), and is a value based on the mass of the epoxy resin (A). The total chlorine content of the epoxy resin (A) is measured by the following method. The epoxy resin (A) is repeatedly washed with trimethylbenzene and filtered until no epoxy resin remains in the xylene washing solution. The filtrate is then distilled under reduced pressure at 100°C or less to obtain the epoxy resin. 1 to 10 g of the obtained epoxy resin sample is precisely weighed to a titer of 3 to 7 mL, dissolved in 25 mL of ethylene glycol monobutyl ether, and 25 mL of 1 N KOH propylene glycol solution is added to the solution, followed by boiling for 20 minutes. The total chlorine content is then calculated from the titer obtained by titration with an aqueous silver nitrate solution.

[0020] (Curing Agent (B)) The epoxy resin composition of this embodiment contains a curing agent (B). From the viewpoint of storage stability, the curing agent (B) of this embodiment is preferably in the form of particles (hereinafter, may be referred to as curing agent particles (B) or curing agent particles (B-1)). The curing agent particles (B) used in the epoxy resin composition of this embodiment are preferably a curing agent that is solid at 25°C and 1013 hPa. By dispersing the curing agent particles (B) in the epoxy resin composition and using a mechanism in which the curing reaction starts at a predetermined temperature and after a predetermined time has elapsed since the start of heating, an epoxy resin composition that combines reactivity and storage stability can be provided.

[0021] The curing agent (B) used in the epoxy resin composition of this embodiment is preferably a capsule-type curing agent in which the surface of a core particle is coated with a shell. By using the curing agent particles (B) in the above configuration, an epoxy resin composition can be provided which exhibits a small residual heat generation amount measured by a differential scanning calorimeter (DSC) even when cured under low-temperature conditions, and which exhibits a small decrease in adhesive strength even after storage in a humid and heat environment. The reasons for this are considered as follows.

[0022] The residual heat release measured by differential scanning calorimetry (DSC) is an indicator of the amount of unreacted epoxy resin (A) and curing agent particles (B). When curing is performed at low temperatures using curing agent particles without a microcapsule coating layer, the curing reaction proceeds, but unreacted epoxy resin and curing agent particles remain, tending to increase the residual heat release. This is because the reaction initiation temperature of the primary amino groups and secondary amino groups in the curing agent particles is low, and the reaction with the epoxy resin surrounding the curing agent particles proceeds before the curing agent particles dissolve and diffuse into the epoxy resin. As a result, the curing agent particles are left behind in the cured epoxy resin, preventing them from diffusing and leaving unreacted epoxy resin and curing agent particles. On the other hand, when a microcapsule-type curing agent in which the surface of the core particles is coated with a shell is used as the curing agent particles (B), the shielding effect of the capsule membrane prevents the reaction between the epoxy resin and the curing agent component from starting until a certain temperature is reached. After the certain temperature is reached, the curing agent component rapidly diffuses, resulting in uniform curing of the entire epoxy resin composition and a small residual heat release. Therefore, the extent of decrease in adhesive strength is small even after storage in a humid and hot environment. The optimum contents of the primary amino group and the secondary amino group in the curing agent particles will be described later.

[0023] Furthermore, the residual heat release value of the epoxy resin composition of this embodiment, measured by differential scanning calorimetry (DSC) of a cured product cured at 80°C for 60 minutes, is preferably 20.0% or less, more preferably 10.0% or less, even more preferably 5.0% or less, and even more preferably 2.0% or less. This ensures that the amount of unreacted epoxy resin and curing agent particles remaining is sufficiently small, resulting in a uniformly cured cured product and a sufficiently small decrease in adhesive strength after storage in a humid and hot environment. Methods for controlling the residual heat release value of the epoxy resin composition measured by differential scanning calorimetry (DSC) include coating the surface of the curing agent particles (B) with a microcapsule shell and adjusting the type of material constituting the curing agent particles. The residual heat release value of the epoxy resin composition of this embodiment can be specifically measured by the method described in the Examples section below.

[0024] The curing agent particles (B) preferably have a particle size D50 at an undersize cumulative fraction of 50% greater than 0.3 μm and 12 μm or less. Having a D50 of greater than 0.3 μm further prevents aggregation of cores, facilitating the formation of a microcapsule coating layer and providing the epoxy resin composition of this embodiment with practically sufficient storage stability. Having an average core particle size of 12 μm or less allows a homogeneous cured product to be obtained upon curing of the epoxy resin composition of this embodiment. Furthermore, having an average core particle size of 12 μm or less prevents the formation of large aggregates when the epoxy resin composition of this embodiment is blended with diluents, fillers, pigments, dyes, flow control agents, thickeners, reinforcing agents, mold release agents, wetting agents, stabilizers, flame retardants, surfactants, organic solvents, conductive fine particles, crystalline alcohols, and other resins, thereby providing sufficient long-term reliability for the cured product. The range of D50 of the curing agent particles (B) is preferably larger than 0.3 μm as the lower limit, more preferably 0.4 μm or more, and even more preferably 0.5 μm or more, and is preferably 12 μm or less as the upper limit, more preferably 10 μm or less, and even more preferably 9 μm or less.

[0025] The curing agent particles (B) used in the epoxy resin composition of this embodiment have a specific surface area of ​​(Y) (m ２ When the particle diameter D50 at an undersize cumulative fraction of 50% is (X) (μm), it is preferable that the values ​​of (X) and (Y) satisfy the following relational expression (2): 4.0(X) -１ ≦(Y) ≦8.3(X) -１ ... (2) By configuring the curing agent particles (B) as described above, the surfaces of the core particles can be easily coated uniformly with a microcapsule layer. As a result, even when cured under low temperature conditions, the entire epoxy resin composition is cured uniformly, and it becomes easier to prepare an epoxy resin composition with little loss in adhesive strength even after storage in a humid and hot environment. In addition, improved storage stability and a reduced viscosity of the epoxy resin formulation can be expected. The particle size D50 value (X) (μm) of the curing agent particles (B) at an undersize cumulative fraction of 50% can be controlled by methods such as increasing the grinding pressure in the grinding process or increasing the raw material supply rate in the grinding process. In addition, the specific surface area value (Y) (m ２ / g) can be controlled by a shape correction method using physical collision between curing agent particles or a shape correction method using heat. By adjusting these values, it is possible to control the particle size D50 and specific surface area of ​​the curing agent particles (B) to satisfy the relational expression (2). The particle size D50 and specific surface area of ​​the curing agent particles (B) can be measured by the methods described in the Examples below.

[0026] The content of the curing agent (B) in the epoxy resin composition of this embodiment is preferably 5.0% by mass or more and 65.0% by mass or less, more preferably 10.0% by mass or more and 60.0% by mass or less, and even more preferably 15.0% by mass or more and 55.0% by mass or less, based on the total amount of the epoxy resin (A) and the curing agent (B). By setting the content of the curing agent (B) within the above range, an epoxy resin composition having an excellent balance between curability and viscosity tends to be obtained.

[0027] As described above, when the total amine value of curing agent (B) is (a) and the tertiary amine value is (b), the values ​​of (a) and (b) satisfy the following relational expression (1): (a) - (b) ≧ 5.0 (1) By using curing agent (B) that satisfies the above relational expression (1), an epoxy resin composition can be provided that exhibits excellent adhesive strength even when cured under low-temperature conditions and exhibits little decrease in adhesive strength even after storage in a humid and hot environment. The reason for this is considered as follows: The adhesive strength of an epoxy resin composition is correlated with the degree of reaction progress between the epoxy resin and the curing agent after thermal curing, and adhesive strength tends to increase as the reaction progresses. As described above, when a curing agent containing both primary and secondary amino groups per molecule is used, the reaction with the epoxy groups proceeds at low temperatures, thereby increasing adhesive strength. The value of (a) - (b) indicates the total amount of primary and secondary amino groups, and a curing agent that satisfies the above relational expression (1) contains both primary and secondary amino groups. When the value of (a) - (b) is 5.0 or more, sufficient reactivity is obtained under low temperature conditions, the reaction between the epoxy resin and the curing agent progresses, and practically sufficient adhesive strength is obtained. Therefore, the curing agent (B) is required to satisfy the above relational expression (1).

[0028] From the viewpoint of the adhesive strength of the epoxy resin composition of this embodiment, the lower limit of (a) - (b) is preferably 30.0 or more, more preferably 60.0 or more, and even more preferably 100.0 or more. Furthermore, the upper limit of (a) - (b) is not particularly limited, but from the viewpoint of the storage stability of the epoxy resin composition of this embodiment, it is preferably 500 or less, more preferably 450 or less, and even more preferably 400 or less.

[0029] Examples of methods for controlling the value of (a) - (b) include a method of selecting the type of raw material amine for the curing agent (B), a method of adding an additive to the curing agent (B), etc. The total amine value, tertiary amine value, and value of (a) - (b) of the curing agent (B) used in the epoxy resin composition of this embodiment can be measured by the methods described in the Examples below.

[0030] From the viewpoint of the flexural strength of the cured product of the epoxy resin composition of this embodiment, the total amine value (a) of the curing agent (B) is preferably 60 or more, more preferably 100 or more, even more preferably 150 or more, and even more preferably 200 or more. There are no particular limitations on the upper limit of the total amine value (a) of the curing agent (B), but from the viewpoint of the storage stability of the epoxy resin composition of this embodiment, it is preferably 500 or less, more preferably 450 or less, and even more preferably 400 or less. The total amine value (a) of the curing agent (B) can be controlled within the above numerical range by appropriately selecting the type of raw material amine for the curing agent (B).

[0031] The curing agent (B) preferably contains at least one reaction product of an epoxy resin (C) and an amine compound (D). By using the curing agent (B) in the above-described configuration, it tends to be easier to prepare an epoxy resin composition that has both reactivity and storage stability.

[0032] The epoxy resin (C) constituting the curing agent (B) is not limited to the following, but may be, for example, a monoepoxy compound, a polyepoxy compound, or a mixture thereof.

[0033] Examples of the monoepoxy compound include, but are not limited to, butyl glycidyl ether, hexyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, para-tert-butylphenyl glycidyl ether, ethylene oxide, propylene oxide, paraxylyl glycidyl ether, glycidyl acetate, glycidyl butyrate, glycidyl hexoate, and glycidyl benzoate.

[0034] The polyvalent epoxy compound is not limited to the following, but examples thereof include bisphenol-type epoxy resins obtained by glycidylating bisphenols such as bisphenol A, bisphenol F, bisphenol AD, bisphenol S, tetramethylbisphenol A, tetramethylbisphenol F, tetramethylbisphenol AD, tetramethylbisphenol S, tetrabromobisphenol A, tetrachlorobisphenol A, and tetrafluorobisphenol A; epoxy resins obtained by glycidylating other dihydric phenols such as biphenol, dihydroxynaphthalene, and 9,9-bis(4-hydroxyphenyl)fluorene; epoxy resins obtained by glycidylating trisphenols such as 1,1,1-tris(4-hydroxyphenyl)methane and 4,4-(1-(4-(1-(4-hydroxyphenyl)-1-methylethyl)phenyl)ethylidene)bisphenol; and epoxy resins obtained by glycidylating tetrakisphenols such as 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane. glycidyl epoxy resins; novolac-type epoxy resins obtained by glycidylating novolacs such as phenol novolac, cresol novolac, bisphenol A novolac, brominated phenol novolac, and brominated bisphenol A novolac; epoxy resins obtained by glycidylating polyhydric phenols; aliphatic ether-type epoxy resins obtained by glycidylating polyhydric alcohols such as glycerin and polyethylene glycol; ether ester-type epoxy resins obtained by glycidylating hydroxycarboxylic acids such as p-oxybenzoic acid and β-oxynaphthoic acid; ester-type epoxy resins obtained by glycidylating polycarboxylic acids such as phthalic acid and terephthalic acid; glycidyl-type epoxy resins such as glycidyl compounds of amine compounds such as 4,4-diaminodiphenylmethane and m-aminophenol, and amine-type epoxy resins such as triglycidyl isocyanurate; and alicyclic epoxides such as 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate.

[0035] Here, as the epoxy resin (C), from the viewpoint of further improving the storage stability of the epoxy resin composition of this embodiment, a polyvalent epoxy compound is preferred, and a glycidyl-type epoxy resin is more preferred. Among these, from the viewpoint of further improving the adhesiveness and heat resistance of the cured product, an epoxy resin obtained by glycidylating a polyhydric phenol, particularly a bisphenol-type epoxy resin, is preferred. More specifically, an epoxy resin obtained by glycidylating bisphenol A or an epoxy resin obtained by glycidylating bisphenol F is suitable. In particular, an epoxy resin obtained by glycidylating bisphenol A is more preferred. These may be used alone or in combination of two or more types.

[0036] The amine compound (D) constituting the curing agent (B) is not limited to the following, but examples thereof include aliphatic amine compounds, alicyclic amine compounds, and aromatic amine compounds. Among these, from the viewpoint of improving the Tg of the cured product of the epoxy resin composition of this embodiment, alicyclic amine compounds and aromatic amine compounds are preferred. More specifically, from the viewpoint of the adhesiveness and reaction rate of the epoxy resin composition of this embodiment, alicyclic amine compounds are even more preferred.

[0037] Examples of the aliphatic amine compound include, but are not limited to, methylamine, ethylamine, propylamine, butylamine, ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, trimethylhexamethylenediamine, 2-methylpentamethylenediamine, ethanolamine, propanolamine, N,N-dimethylaminopropylamine, and N,N-dimethylethylenediamine.

[0038] Examples of aromatic amine compounds include, but are not limited to, aniline, toluidine, diaminodiphenylmethane, diaminodiphenylsulfone, phenylmethylamine, phenylethylamine, o-xylylenediamine, m-xylylenediamine, p-xylylenediamine, 1,2-phenylenediamine, 1,3-phenylenediamine, and 1,4-phenylenediamine.

[0039] Examples of alicyclic amine compounds include, but are not limited to, cyclohexylamine, isophoronediamine, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 1,3-bisaminomethylcyclohexane, 1,4-bisaminomethylcyclohexane, bis(4-aminocyclohexyl)methane, norbornenediamine, N,N-dimethyl-1,4-cyclohexanediamine, etc. Of these, 1,3-bisaminomethylcyclohexane is preferred from the viewpoint of crack resistance of the cured product.

[0040] The content of the amine compound (D) in the curing agent (B) is preferably 0.000001% by mass or more and 3.0% by mass or less. It is more preferably 0.000001% by mass or more and 2.0% by mass or less, even more preferably 0.000001% by mass or more and 1.0% by mass or less, and even more preferably 0.000001% by mass or more and 0.5% by mass or less. By setting the content of the amine compound (D) in the curing agent (B) within the above range, an epoxy resin composition with good storage stability tends to be obtained. The content of the amine compound (D) in the curing agent (B) can be controlled within the above numerical range by adjusting the temperature, degree of vacuum, and vacuum time in the distillation step after producing the reaction product of the epoxy resin (C) and the amine compound (D).

[0041] The curing agent (B) preferably has a light transmittance of 50.0% or more at a wavelength of 365 nm measured by ultraviolet-visible spectroscopy of a dimethylformamide (DMF) solution containing 1.0% by mass of the curing agent (B). It is more preferably 70.0% or more, and even more preferably 90.0% or more. By controlling the light transmittance of the curing agent (B) within the above range, an epoxy resin composition exhibiting good light transmittance can be obtained, which can be suitably used as an adhesive for photocuring applications. The light transmittance of the curing agent (B) can be controlled within the above numerical range, for example, by adjusting the composition of the materials constituting the curing agent (B), adjusting the amount of additives, or by avoiding contact with oxygen during heating in the curing agent production process (reaction process and desolvation process). The light transmittance can also be measured by the method described in the Examples below.

[0042] As described above, the curing agent (B) is preferably curing agent particles (B-1). Also, as described above, the curing agent (B) preferably contains at least one reaction product of an epoxy resin (C) and an amine compound (D). Furthermore, as described above, the curing agent (B) preferably has a light transmittance of 50.0% or more at a wavelength of 365 nm as measured by ultraviolet-visible spectroscopy when prepared as a 1.0% by mass dimethylformamide (DMF) solution. That is, the epoxy resin composition of this embodiment contains an epoxy resin (A) and curing agent particles (B-1), and the curing agent particles (B-1) have a total amine value (a) and a tertiary amine value (b), and the values ​​of (a) and (b) satisfy the following relational expression (1): (a) - (b) ≧ 5.0 (1). The curing agent particles (B-1) contain at least one reaction product of an epoxy resin (C) and an alicyclic amine compound (D), and the epoxy resin composition has a light transmittance of 50.0% or more at a wavelength of 365 nm as measured by ultraviolet-visible spectroscopy when the curing agent particles (B-1) are dissolved in a 1.0 mass % dimethylformamide (DMF) solution. Note that the epoxy resin composition may contain a curing agent other than the curing agent particles (B-1).

[0043] As described above, the amine compound (D) is preferably an alicyclic compound. That is, in the epoxy resin composition of this embodiment, the curing agent (B) preferably satisfies the following conditions (i) to (iii): (i) It is curing agent particles (B-1). (ii) When prepared as a 1.0 mass % dimethylformamide (DMF) solution, the light transmittance at a wavelength of 365 nm as measured by ultraviolet-visible spectroscopy is 50.0% or more. (iii) It contains at least one reaction product of an epoxy resin (C) and an amine compound (D), and the amine compound (D) is an alicyclic amine.

[0044] As described above, the amine compound (D) is preferably 1,3-bis(aminomethyl)cyclohexane. That is, in the epoxy resin composition of this embodiment, the curing agent (B) preferably satisfies the following conditions (i), (ii), and (iv): (i) the curing agent (B-1) is a particle of the curing agent; (ii) when prepared as a 1.0% by mass dimethylformamide (DMF) solution, the light transmittance at a wavelength of 360 nm measured by ultraviolet-visible spectroscopy is 50.0% or more; and (iv) the curing agent (B-1) contains at least one reaction product of the epoxy resin (C) and the amine compound (D), and the amine compound (D) is 1,3-bis(aminomethyl)cyclohexane.

[0045] As described above, the curing agent (B) is preferably curing agent particles (B-1), and is a capsule-type curing agent in which the surface of a core particle is coated with a shell. That is, in the epoxy resin composition of this embodiment, the curing agent (B) preferably satisfies the following conditions (i), (ii), (iv), and (v): (i) It is curing agent particles (B-1). (ii) When prepared as a 1.0 mass% dimethylformamide (DMF) solution, the curing agent has a light transmittance of 50.0% or more at a wavelength of 365 nm as measured by ultraviolet-visible spectroscopy. (iv) It contains at least one reaction product of an epoxy resin (C) and an amine compound (D), and the amine compound (D) is 1,3-bis(aminomethyl)cyclohexane. (v) It is a capsule-type curing agent in which the surface of a core particle is coated with a shell.

[0046] By adopting the above-mentioned preferred embodiment, an epoxy resin composition that has both high reactivity and high storage stability tends to be obtained.

[0047] From the viewpoint of reactivity, the curing agent (B) preferably contains, in addition to the amine compound (D) contained in the curing agent (B), a low molecular weight amine compound (E) having a tertiary amino group with a molecular weight of not more than 1000. The content of the low molecular weight amine compound (E) in the curing agent (B) is preferably 0.1% by mass or more and 30.0% by mass or less, more preferably 1.0% by mass or more and 25.0% by mass or less, and even more preferably 2.0% by mass or more and 20.0% by mass or less.

[0048] By including the low-molecular-weight amine compound (E) having a tertiary amino group in the curing agent (B), the curing agent (B) can be suitably used as an accelerator for the curing agent consisting of a thiol compound. That is, the epoxy resin composition of this embodiment preferably includes an epoxy resin (A), a curing agent (B) containing the low-molecular-weight amine compound (E) having a tertiary amino group, and a curing agent (F) consisting of a thiol compound. The content of the low-molecular-weight amine compound (E) having a tertiary amino group is preferably 0.001 parts by mass or more and 10.0 parts by mass or less, more preferably 0.005 parts by mass or more and 7.5 parts by mass or less, and even more preferably 0.01 parts by mass or more and 5.0 parts by mass or less, per 100 parts by mass of the epoxy resin (A). Setting the content of the low-molecular-weight amine compound (E) having a tertiary amino group within the above range tends to provide an epoxy resin composition with an excellent balance between reactivity and storage stability.

[0049] The content of the low-molecular-weight amine compound (E) having a tertiary amino group in the epoxy resin composition of the present embodiment can be controlled within the above-mentioned numerical range by adjusting the amount of the low-molecular-weight amine compound (E) having a tertiary amino group added in the curing agent (B) and by adjusting the amount of the curing agent (B) added.

[0050] Examples of the low molecular weight amine compound (E) having a tertiary amino group include, but are not limited to, trimethylamine, triethylamine, benzyldimethylamine, N,N-dimethylethylamine, N,N-dimethylbutylamine, N,N-dimethyldecylamine, N,N-dimethylm-toluidine, N,N-dimethylp-toluidine, 2,6,10-trimethyl-2,6,10-triazaundecane, N,N'-dimethylpiperazine, 1,4-diazabicyclo[2.2.2]octane, (1,4-diazabicyclo[2.2.2]octan-2-yl)methanol, 1-azabicyclo[2.2.2]octan-3-one, 1,8-diazabicyclo(5,4,0)-undecane, and the like. tertiary amines such as 1-phenyl-7, 1,5-diazabicyclo(4,3,0)-nonene-5, and hexamethylenetetramine; imidazoles such as 1-methylimidazole, 1,2-dimethylimidazole, 1-vinylimidazole, 1-allylimidazole, 2-methyl-1-vinylimidazole, and N-acetylimidazole; aromatic tertiary amines such as dimethylaminobenzhydrol, bis[4-(dimethylamino)phenyl]methane, 4,4'-bis(dimethylamino)benzophenone, and 2-diethylamino-N-(2,6-dimethylphenyl)acetamide; and aminopyridines having a tertiary amino group such as 2-dimethylaminopyridine and 4-dimethylaminopyridine. Here, as the low molecular weight amine compound (E) having a tertiary amino group, 1,4-diazabicyclo[2.2.2]octane and (1,4-diazabicyclo[2.2.2]octan-2-yl)methanol are preferred from the viewpoint of reactivity when used as an accelerator for a thiol curing agent. These amine compounds may be used alone or in combination of two or more.

[0051] As described above, the curing agent (B) used in the epoxy resin composition of this embodiment is preferably a curing agent particle, and more preferably a microcapsule-type curing agent in which the surface of a core particle is coated with a shell. The shell preferably contains a synthetic resin and / or an inorganic oxide. Among these, from the viewpoints of the stability of the film constituting the shell, the ease of destruction during heating, and the uniformity of the cured product of the epoxy resin composition of this embodiment, the material constituting the shell preferably contains a synthetic resin.

[0052] The synthetic resin contained in the shell constituting the curing agent particles (B) is not limited to the following, but examples thereof include epoxy resins, phenol resins, polyester resins, polyethylene resins, nylon resins, polystyrene resins, urethane resins, etc. Among these, epoxy resins, phenol resins, and urethane resins are preferred as the synthetic resin from the viewpoint of the balance between the stability of the film constituting the shell and its destructibility upon heating.

[0053] Examples of epoxy resins used for the shell include, but are not limited to, epoxy resins having two or more epoxy groups, resins produced by the reaction of an epoxy resin having two or more epoxy groups with a compound having two or more active hydrogens, and reaction products of a compound having two or more epoxy groups with a compound having one active hydrogen and a carbon-carbon double bond. Among these, from the viewpoint of stability, resins produced by the reaction of a compound having two or more epoxy groups with a compound having two or more active hydrogens are preferred, and reaction products of an amine-based curing agent and an epoxy resin having two or more epoxy groups are particularly preferred.

[0054] Examples of phenolic resins used for the shell include, but are not limited to, phenol-formaldehyde polycondensates, cresol-formaldehyde polycondensates, resorcinol-formaldehyde polycondensates, bisphenol A-formaldehyde polycondensates, and polyethylene polyamine-modified phenol-formaldehyde polycondensates.

[0055] Examples of polyester resins used for the shell include, but are not limited to, ethylene glycol-terephthalic acid-polypropylene glycol polycondensates, ethylene glycol-butylene glycol-terephthalic acid polycondensates, and terephthalic acid-ethylene glycol-polyethylene glycol polycondensates.

[0056] The polyethylene resin used for the shell is not limited to the following, but examples thereof include ethylene-propylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl acetate-acrylic acid copolymer, and the like.

[0057] The nylon resin used for the shell is not limited to the following, but examples thereof include adipic acid-hexamethylenediamine polycondensate, sebacic acid-hexamethylenediamine polycondensate, and p-phenylenediamine-terephthalic acid polycondensate.

[0058] Examples of polystyrene resins used for the shell include, but are not limited to, styrene-butadiene copolymers, styrene-butadiene-acrylonitrile copolymers, acrylonitrile-styrene-divinylbenzene copolymers, and styrene-propenyl alcohol copolymers.

[0059] Examples of urethane resins used for the shell include, but are not limited to, isocyanate monomers such as butyl isocyanate, cyclohexyl isocyanate, octadecyl isocyanate, phenyl isocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, tolidine diisocyanate, naphthalene diisocyanate, and triphenylmethane triisocyanate, or condensates thereof, or polycondensates of polymers thereof with monoalcohols or polyhydric alcohols. Among these, urethane resins which are addition polymers of monoalcohols or polyhydric alcohols and monoisocyanates or polyhydric isocyanates are preferred.

[0060] Examples of inorganic oxides used for the shell include, but are not limited to, boron oxide, boron compounds such as boric acid esters, silicon dioxide, calcium oxide, etc. Among these, boron oxide is preferred from the viewpoints of the stability of the film constituting the shell and its ease of destruction when heated.

[0061] In addition, from the viewpoint of the balance between storage stability and reactivity, the shell constituting the (B) curing agent particles has a wave number of 1630 to 1680 cm －１ and a urea bond that absorbs infrared radiation at a wave number of 1680 to 1725 cm －１ and a biuret bond that absorbs infrared radiation at a wave number of 1730 to 1755 cm －１ Preferably, the shell contains a urethane bonding group that absorbs infrared radiation. The urea bonding group, biuret bonding group, and urethane bonding group can be detected by measurement using a Fourier transform infrared spectrophotometer (hereinafter sometimes referred to as "FT-IR"). Furthermore, the presence of urea bonding groups, biuret bonding groups, and urethane bonding groups in the shell can be confirmed by microscopic FT-IR. Specifically, a modified aliphatic polyamine curing agent is added to the epoxy resin composition of this embodiment, and the composition is cured at 40°C for 12 hours, and then the epoxy resin portion is completely cured at 120°C for an additional 24 hours. A sample having a thickness of 5 to 20 μm is then prepared from the resulting cured product using an ultramicrotome, and the depth direction of the shell is analyzed using microscopic FT-IR. The presence of urea bonding groups, biuret bonding groups, and urethane bonding groups can be observed by observing the surface of the shell.

[0062] In terms of the reactivity and viscosity of the epoxy resin composition, the content of the curing agent particles (B) in the epoxy resin composition of this embodiment is preferably 5.0% by mass or more and 65.0% by mass or less, more preferably 10.0% by mass or more, and even more preferably 15.0% by mass or more, based on the total amount of the epoxy resin (A) and the curing agent particles (B). Furthermore, it is more preferably 60.0% by mass or less, and even more preferably 55.0% by mass or less.

[0063] (Thiol Compound (F)) As described above, the epoxy resin composition of this embodiment may contain a curing agent (F) composed of a thiol compound. The content of the thiol compound (F) in the epoxy resin composition of this embodiment is such that the thiol equivalent ratio relative to the epoxy equivalent of the epoxy resin (A) is preferably 0.3 or more and 2.5 or less, more preferably 0.5 or more and 2.0 or less, and even more preferably 0.7 or more and 1.5 or less. By setting the content of the thiol compound (F) within the above range, a cured product with excellent adhesive strength tends to be obtained.

[0064] The thiol compound (F) preferably has two or more thiol groups in the molecule. The thiol compound (F) preferably includes a thiol compound having no ester bond. By using a thiol compound having no ester bond, the cured product of the epoxy resin composition of this embodiment tends to be less prone to hydrolysis even under high temperature and high humidity conditions, and the reliability of the adhesive strength is increased.

[0065] The thiol compound (F) may contain a polyfunctional thiol compound having an ester bond. Examples of the polyfunctional thiol compound having an ester bond include, but are not limited to, trimethylolpropane tris(3-mercaptopropionate) (manufactured by SC Organic Chemical Co., Ltd.: TMMP), pentaerythritol tetrakis(3-mercaptopropionate) (manufactured by SC Organic Chemical Co., Ltd.: PEMP), tetraethylene glycol bis(3-mercaptopropionate) (manufactured by SC Organic Chemical Co., Ltd.: EGMP-4), dipentaerythritol hexakis(3-mercaptopropionate) (SC Examples of suitable mercaptobutyrates include DPMP (manufactured by Showa Denko K.K.), Karenz MT (registered trademark) PE1 (manufactured by Showa Denko K.K.), tris-[(3-mercaptopropionyloxy)-ethyl]-isocyanurate (TEMPIC (manufactured by SC Organic Chemical Co., Ltd.), and 1,3,5-tris(3-mercaptobutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione (manufactured by Showa Denko K.K.: Karenz MT (registered trademark) NR1).

[0066] Examples of thiol compounds without an ester bond include, but are not limited to, 1,3,4,6-tetrakis(2-mercaptoethyl)glycoluril (trade name: TS-G, manufactured by Shikoku Chemical Industry Co., Ltd.), 1,3,4,6-tetrakis(3-mercaptopropyl)glycoluril (trade name: C3 TS-G, manufactured by Shikoku Chemical Industry Co., Ltd.), 1,3,4,6-tetrakis(mercaptomethyl)glycoluril, 1,3,4,6-tetrakis(mercaptomethyl)-3a-methylglycoluril, 1,3,4,6-tetrakis(2-mercaptoethyl)-3a-methylglycoluril, 1,3,4,6-tetrakis(3-mercaptopropyl)-3a-methylglycoluril, 1,3,4,6-tetrakis(mercaptomethyl)-3a,6a-dimethylglycoluril, 1,3,4,6-tetrakis(2-mercaptoethyl)-3a,6a-dimethylglycoluril Examples of suitable esters include 1,3,4,6-tetrakis(3-mercaptopropyl)-3a,6a-dimethylglycoluril, 1,3,4,6-tetrakis(mercaptomethyl)-3a,6a-diphenylglycoluril, 1,3,4,6-tetrakis(2-mercaptoethyl)-3a,6a-diphenylglycoluril, 1,3,4,6-tetrakis(3-mercaptopropyl)-3a,6a-diphenylglycoluril, pentaerythritol trippropanethiol (trade name: PEPT, manufactured by SC Organic Chemicals), pentaerythritol tetrapropanethiol (trade name: Multiol Y4, manufactured by SC Organic Chemicals), and pentaerythritol tetrapropanethiol. These esters may be used alone or in combination of two or more. Of these, pentaerythritol tetrapropanethiol is particularly preferred from the viewpoints of reactivity and storage stability.

[0067] From the viewpoint of reactivity in a low-temperature environment, the epoxy resin composition of the present embodiment preferably contains the epoxy resin (A), the curing agent particles (B) containing the low-molecular-weight amine compound (E) having a tertiary amino group and a molecular weight of 1,000 or less, and the thiol compound (F).

[0068] (Filler Particles) The epoxy resin composition of the present embodiment may contain an organic filler and / or an inorganic filler, if necessary.

[0069] Examples of organic fillers include, but are not limited to, thermoplastic resins such as triblock copolymers, thermoplastic elastomers, carbon fibers, cellulose, polyethylene powder, polypropylene powder, etc. These organic fillers may be used alone or in combination of two or more.

[0070] Examples of inorganic fillers include, but are not limited to, fused silica, crystalline silica, alumina, talc, silicon nitride, aluminum nitride, zinc oxide (ZnO), coal tar, glass fiber, asbestos fiber, boron fiber, quartz powder, mineral silicate, mica, asbestos powder, slate powder, etc. These inorganic fillers may be used alone or in combination of two or more.

[0071] These organic fillers and inorganic fillers have the function of changing the viscoelasticity of the epoxy resin composition to optimize the viscosity, storage modulus, and thixotropy, and further tend to improve the fracture toughness of the cured product of the epoxy resin composition and reduce cure shrinkage.

[0072] From the viewpoints of sufficiently optimizing thixotropy and improving fracture toughness, the content of the filler particles in the epoxy resin composition of the present embodiment is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 25% by mass or more. Furthermore, from the viewpoints of sufficiently low viscosity and excellent handleability, the content of the filler particles in the epoxy resin composition of the present embodiment is preferably 85% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less.

[0073] (Additives) In addition to the components described above, the epoxy resin composition of the present embodiment may further contain, as necessary, additives such as an epoxy acrylic resin, a urethane acrylic resin, a (meth)acrylic acid ester, a colorant, a silane coupling agent, an antioxidant, a photopolymerization initiator, a polymerization inhibitor, an antifoaming agent, a diluent, a reactive diluent, a flow control agent, a thickener, a reinforcing agent, a release agent, a wetting agent, a flame retardant, a surfactant, and resins.

[0074] <Epoxy Acrylic Resin> Epoxy resins that can be used as raw materials when producing an epoxy acrylic resin include, but are not limited to, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, 2,2'-diallyl bisphenol A type epoxy resins, hydrogenated bisphenol type epoxy resins, propylene oxide-added bisphenol A type epoxy resins, resorcinol type epoxy resins, biphenyl type epoxy resins, sulfide type epoxy resins, diphenyl ether type epoxy resins, dicyclopentadiene type epoxy resins, naphthalene type epoxy resins, phenol novolac type epoxy resins, o-cresol novolac type epoxy resins, dicyclopentadiene novolac type epoxy resins, biphenyl novolac type epoxy resins, naphthalene phenol novolac type epoxy resins, glycidylamine type epoxy resins, alkyl polyol type epoxy resins, rubber-modified type epoxy resins, glycidyl ester compounds, and bisphenol A type episulfide resins.

[0075] Commercially available epoxy acrylic resins include, but are not limited to, EA-1010, EA-1020, EA-5323, EA-5520, EA-CHD, and EMA-1020 (all manufactured by Shin-Nakamura Chemical Co., Ltd.), Ebecryl 860, Ebecryl 3200, Ebecryl 3201, Ebecryl 3412, Ebecryl 3600, Ebecryl 3700, Ebecryl 3701, Ebecryl 3702, Ebecryl 3703, Ebecryl 3800, Ebecryl 6040, and Ebecryl RDX63182 (all manufactured by Daicel-Cytec Co., Ltd.), and Epoxy S Epoxy Ester M-600A, Epoxy Ester 40EM, Epoxy Ester 70PA, Epoxy Ester 200PA, Epoxy Ester 80MFA, Epoxy Ester 3002M, Epoxy Ester 3002A, Epoxy Ester 1600A, Epoxy Ester 3000M, Epoxy Ester 3000A, Epoxy Ester 200EA, Epoxy Ester 400EA (all manufactured by Kyoeisha Chemical Co., Ltd.), Denacol Acrylate DA-141, Denacol Acrylate DA-314, Denacol Acrylate DA-911 (all manufactured by Nagase ChemteX Corporation), etc. The epoxy acrylic resin may be used alone or in combination of two or more.

[0076] <Urethane Acrylic Resin> The urethane acrylic resin is preferably an aliphatic polyether urethane acrylate or acrylic acid ester, more preferably a polyfunctional polyether (meth)acrylate oligomer. The polyether (meth)acrylate oligomer has at least one (meth)acrylate group, for example, 1 to 4 (meth)acrylate groups. The polyfunctional polyether (meth)acrylate oligomer is preferably a difunctional aliphatic urethane acrylate oligomer. The polyfunctional urethane acrylate oligomer is prepared, for example, from an aliphatic polyester or polyether polyol prepared by condensation of a dicarboxylic acid (e.g., adipic acid or maleic acid) with an aliphatic diol (e.g., diethylene glycol or 1,6-hexanediol). In one embodiment, the polyester polyol may contain adipic acid and diethylene glycol. The polyfunctional isocyanate may include methylene dicyclohexyl isocyanate or 1,6-hexamethylene diisocyanate. The hydroxy-functionalized acrylate may include a hydroxyalkyl acrylate, such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, or polyethylene glycol acrylate. In one aspect, the multifunctional urethane acrylate oligomer may include the reaction product of a polyester polyol, methylene dicyclohexyl isocyanate, and hydroxyethyl acrylate.

[0077] Specific examples of urethane acrylic resins include BR-3042, BR-3641 AA, BR-3741 AB, and BR-344 manufactured by Bomar Specialties Co.; CN-9002, CN-980, CN-981, and CN-9019 manufactured by Sartomer Company Inc.; Genomer 4188 / EHA, Genomer 4269 / M22, Genomer 4425, Genomer 1122, and Genomer 6043 manufactured by Rahn AG; and UV-3630ID80, UV-3630ID80, UV-NS054, and UV-NS077 manufactured by Nippon Soda Co., Ltd. Bifunctional aliphatic polyester urethane acrylate oligomers and bifunctional aliphatic polyester / ether urethane acrylate oligomers are also preferred urethane acrylic resins. These may be used alone or in combination of two or more.

[0078] <(Meth)acrylic acid ester> The (meth)acrylic acid ester may be a monofunctional (meth)acrylic acid ester or a polyfunctional (meth)acrylic acid ester. Examples of the monofunctional (meth)acrylic acid ester include, but are not limited to, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate, 2-isocyanatoethyl methacrylate, isobornyl methacrylate (for example, product name "IBXA", Osaka Organic Chemical Industry Co., Ltd.), 2-methacryloxyethyltrimethoxysilane, 2-methacryloxyethyltriethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxymethyldiethoxysilane, 4-methacryloxybutyltrimethoxysilane, 4-methacryloxybutyltriethoxysilane, dicyclopentenyloxyethyl methacrylate (for example, product name "FA-512M", manufactured by Hitachi Chemical Co., Ltd.), dicyclopentanyl methacrylate (for example, product name "FA513M", manufactured by Hitachi Chemical Co., Ltd.), pentamethylpiperidyl methacrylate (for example, product name "FA-711MM", manufactured by Hitachi Chemical Co., Ltd.), tetramethylpiperidyl methacrylate (for example, product name "FA-712HM", manufactured by Hitachi Chemical Co., Ltd.), methoxypolyethylene glycol methacrylate (for example, product name "FA-BZM", manufactured by Hitachi Chemical Co., Ltd.), benzyl methacrylate (for example, product name "FA-BZM", manufactured by Hitachi Chemical Co., Ltd.), 2-hydroxy-3-acryloyloxypropyl methacrylate (for example, product name "Light Ester G-201P", manufactured by Kyoei Chemical Co., Ltd.), 2-methacryloyloxyethyl phthalate (for example, product name "CB-1" , manufactured by Shin-Nakamura Chemical Co., Ltd.), methoxypolyethylene glycol methacrylate, phenoxyethylene glycol methacrylate (for example, product name "PHE-1G", manufactured by Shin-Nakamura Chemical Co., Ltd.), stearyl methacrylate (for example, product name "S", manufactured by Shin-Nakamura Chemical Co., Ltd.), 2-methacryloyloxyethyl succinate (for example, product name "SA", manufactured by Shin-Nakamura Chemical Co., Ltd.), and 3,4-epoxycyclohexylmethyl methacrylate (for example, product name "Cyclomer M100", manufactured by Daicel Corporation).

[0079] Examples of bifunctional (meth)acrylic acid esters include, but are not limited to, dipropylene glycol diacrylate (e.g., product name "APG-100", Shin-Nakamura Chemical Co., Ltd.), tricyclodecane dimethanol diacrylate (e.g., product name "A-DCP", Shin-Nakamura Chemical Co., Ltd.), 1,4-butanediol dimethacrylate (e.g., product name "FA-124M", Hitachi Chemical Co., Ltd.), neopentyl glycol dimethacrylate (e.g., product name "FA-125M", Hitachi Chemical Co., Ltd.), polyethylene glycol #200 dimethacrylate (e.g., Examples of such compounds include ethylene glycol dimethacrylate (e.g., product name "FA-220M" manufactured by Hitachi Chemical Co., Ltd.), EO-modified bisphenol A dimethacrylate (e.g., product name "FA-321M" manufactured by Hitachi Chemical Co., Ltd.), EO-modified polypropylene glycol #700 dimethacrylate (e.g., product name "FA-023M" manufactured by Hitachi Chemical Co., Ltd.), ethylene glycol dimethacrylate (e.g., product name "1G" manufactured by Shin-Nakamura Chemical Co., Ltd.), diethylene glycol dimethacrylate (e.g., product name "2G" manufactured by Shin-Nakamura Chemical Co., Ltd.), triethylene glycol dimethacrylate (e.g., product name "3G" manufactured by Shin-Nakamura Chemical Co., Ltd.), manufactured by Shin-Nakamura Chemical Co., Ltd.), polyethylene glycol dimethacrylate (for example, manufactured by Shin-Nakamura Chemical Co., Ltd.), 2,2-bis[4-(methacryloxyethoxy)phenyl]propane (for example, product name "BPE-80N" manufactured by Shin-Nakamura Chemical Co., Ltd.), ethoxylated bisphenol A dimethacrylate (for example, manufactured by Shin-Nakamura Chemical Co., Ltd.), tricyclodecane dimethanol dimethacrylate (for example, product name "DCP" manufactured by Shin-Nakamura Chemical Co., Ltd.), 1,10-decanediol dimethacrylate (for example, product name "DOD-N" manufactured by Shin-Nakamura Chemical Co., Ltd.), 1,6-hexanediol dimethacrylate acrylate (for example, product name "HD-N" manufactured by Shin-Nakamura Chemical Co., Ltd.), 1,9-nonanediol dimethacrylate (for example, product name "NOD-N" manufactured by Shin-Nakamura Chemical Co., Ltd.), neopentyl glycol dimethacrylate (for example, product name "NPG" manufactured by Shin-Nakamura Chemical Co., Ltd.), ethoxylated polypropylene glycol dimethacrylate (for example, manufactured by Shin-Nakamura Chemical Co., Ltd.), glycerin dimethacrylate (for example, product name "701" manufactured by Shin-Nakamura Chemical Co., Ltd.), and polypropylene glycol dimethacrylate (for example, manufactured by Shin-Nakamura Chemical Co., Ltd.).

[0080] Examples of polyfunctional methacrylic acid esters having three or more functional groups include, but are not limited to, trimethylolpropane trimethacrylate (for example, product name "TMPT", manufactured by Shin-Nakamura Chemical Co., Ltd.).

[0081] The (meth)acrylic acid ester may be used alone or in combination of two or more kinds.

[0082] <Colorant> Examples of colorants include pigments and dyes. The inclusion of a pigment can adjust the chromaticity of the epoxy resin composition of this embodiment. Examples of pigments include, but are not limited to, carbon black, titanium black (e.g., titanium nitride), black organic pigments, mixed-color organic pigments, and inorganic pigments. Examples of black organic pigments include perylene black and aniline black. Examples of mixed-color organic pigments include pseudo-black pigments obtained by mixing at least two or more pigments selected from red, blue, green, purple, yellow, magenta, cyan, and the like. Examples of inorganic pigments include fine metal particles such as graphite, titanium, copper, iron, manganese, cobalt, chromium, nickel, zinc, calcium, and silver, metal oxides, composite oxides, metal sulfides, and metal nitrides. These pigments may be used alone or in combination. The pigment is preferably carbon black or titanium black. Examples of the dye include, but are not limited to, anthraquinone dyes, azo dyes, phthalocyanine dyes, quinacridone dyes, dioxazine dyes, anthrapyrimidine dyes, anthanthrone dyes, indanthrone dyes, flavanthrone dyes, pyranthrone dyes, perinone dyes, and thioindigo dyes.

[0083] <Silane Coupling Agent> Examples of silane coupling agents include, but are not limited to, tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, tetrabutoxysilane, dimethoxydiethoxysilane, dimethoxydiisopropoxysilane, diethoxydiisopropoxysilane, and diethoxydibutoxysilane; trialkoxysilanes such as methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, ethyltriethoxysilane, ethoxytributoxysilane, cyclohexyltriethoxysilane, and phenyltriisopropoxysilane; and dialkoxysilanes such as dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, diethyldibutoxysilane, and phenylethyldiethoxysilane. These silane coupling agents may be used alone or in combination of two or more. The amount of the silane coupling agent added is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, based on 100 parts by mass of the epoxy resin (A).

[0084] <Antioxidant> Examples of the antioxidant include phenolic antioxidants, hydroquinone antioxidants, and other antioxidants, with phenolic antioxidants being preferred. Examples of the phenolic antioxidant include, but are not limited to, 2,2-methylene-bis(4-methyl-6-tert-butylphenol), catechol, picric acid, tert-butylcatechol, 2,6-ditert-butyl-p-cresol, and 4,4'-thiobis[ethylene(oxy)(carbonyl)(ethylene)]bis[2,6-bis(1,1-dimethylethyl)phenol]. Hydroquinone-based antioxidants include, but are not limited to, β-naphthoquinone, 2-methoxy-1,4-naphthoquinone, methylhydroquinone, hydroquinone, hydroquinone monomethyl ether, monotertiarybutylhydroquinone, 2,5-ditertiarybutylhydroquinone, p-benzoquinone, 2,5-diphenyl-p-benzoquinone, and 2,5-ditertiarybutyl-p-benzoquinone. Other antioxidants include citric acid, phenothiazine, and 2-butyl-4-hydroxyanisole.

[0085] <Photopolymerization initiator> The photopolymerization initiator is not particularly limited, and those commonly used in the art can be used. Commercially available photopolymerization initiators include, but are not limited to, IRGACURE 651 (2,2-dimethoxy-1,2-diphenylethan-1-one), IRGACURE 184 (1-hydroxy-cyclohexyl-phenyl-ketone), DAROCUR 1173 (2-hydroxy-2-methyl-1-phenyl-propan-1-one), IRGACURE 2959 (1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one), IRGACURE 127 (2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]phenyl}-2-methyl-propan-1-one}, ... 907 (2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one), IRGACURE 369 (2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butanone-1), IRGACURE 379 (2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone), DAROCUR TPO (2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide), IRGACURE819 (bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide), IRGACURE784 (bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl)titanium), IRGACUREOXE01 (1,2-Octanedione, 1-[4-(phenylthio)phenyl]-, 2-(o-benzoyloxime)), IRGACUREOXE02 (Ethanone, 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-,1-(o-acetyloxime)), IRGACURE 754 (a mixture of oxyphenylacetic acid, 2-[2-oxo-2-phenylacetoxyethoxy]ethyl ester and oxyphenylacetic acid, 2-(2-hydroxyethoxy)ethyl ester), Lucirin TPO, LR8893, LR8970 (all manufactured by BASF Japan), DETX-S (2,4-diethylthioxanthone) (manufactured by Nippon Kayaku Co., Ltd.), and Ubecryl P36 (manufactured by UCB). The photopolymerization initiator may be used alone or in combination of two or more.

[0086] <Polymerization Inhibitor> Examples of the polymerization inhibitor include phenol-based polymerization inhibitors and phenothiazine-based polymerization inhibitors. Examples of the phenol-based polymerization inhibitor include, but are not limited to, 2,2-methylene-bis(4-methyl-6-tertiarybutylphenol) (BHT), catechol, picric acid, tertiarybutylcatechol, 2,6-ditertiarybutyl-p-cresol, and 4,4'-thiobis[ethylene(oxy)(carbonyl)(ethylene)]bis[2,6-bis(1,1-dimethylethyl)phenol]. Examples of the phenothiazine-based polymerization inhibitor include, but are not limited to, phenothiazine, bis(α-methylbenzyl)phenothiazine, 3,7-dioctylphenothiazine, and bis(α,α-dimethylbenzyl)phenothiazine.

[0087] [Method for Producing Epoxy Resin Composition] The epoxy resin composition of this embodiment can be obtained by mixing the above-mentioned components (A) and (B), and, as necessary, components (C), (D), (E), and (F), and other additives. The method for mixing the components is not particularly limited, and general mixing equipment and processing conditions can be used. Specific examples include methods for obtaining an epoxy resin composition by thoroughly mixing the components until homogeneous using a mixing roll such as a three-roll mill, a dissolver, a planetary mixer, a kneader, an extruder, or the like.

[0088] [Applications] The epoxy resin composition of this embodiment and the cured product obtained therefrom can be used in a variety of applications in which epoxy resins are used as materials, but are particularly useful as encapsulants (encapsulants formed from the cured product of this embodiment), semiconductor encapsulants, adhesives (adhesives including the epoxy resin composition of this embodiment), and the like. The adhesives may be either heat-curable adhesives or photo-curable adhesives. Furthermore, encapsulants and adhesives using the epoxy resin composition of this embodiment and the cured product thereof are useful in camera modules and semiconductor packages. Among these, the epoxy resin composition is preferably used in composite materials such as dual-cure (photo-cure + heat-cure) adhesives for precision fixation.

[0089] Next, the present embodiment will be described in detail with reference to specific examples and comparative examples, but the present invention is not limited to the following examples and comparative examples. In the following, "parts" and "%" are by mass unless otherwise specified.

[0090] [Epoxy Resin Composition] (Epoxy Resins (A-1) to (A-3), (C-1)) The epoxy resins (A-1) to (A-3), and (C-1) used in the examples and comparative examples described later are shown in Table 1 below.

[0091]

[0092] (Amine Compounds (D-1) to (D-9)) Amine compounds (D-1) to (D-9) used to produce the curing agent particles (B) used in the examples and comparative examples described later are shown in Table 2 below.

[0093]

[0094] (Low molecular weight amine compounds (E-1) to (E-2) having a tertiary amino group) The low molecular weight amine compounds (E-1) to (E-2) having a tertiary amino group used in the examples and comparative examples described later are shown in Table 3 below.

[0095]

[0096] (Hardening Agent Particles (B-1) to (B-23)) The methods for measuring the physical properties of the hardener particles (B-1) to (B-23) used in the examples and comparative examples described later, and production examples are shown below.

[0097] <Methods for Measuring Physical Properties> [Total Amine Value, Tertiary Amine Value] <Method for Separating Curing Agent Particles (B) from Epoxy Resin Composition> To separate the curing agent particles (B) from the epoxy resin composition, the epoxy resin composition was mixed with a specific solvent and the curing agent particles (B) were precipitated using a centrifuge. Specifically, 5.0 g of the specific solvent was added to 5.0 g of the epoxy resin composition, followed by mixing. After centrifugation, the supernatant was removed. Another 5.0 g of the same solvent was added to the precipitate to disperse the curing agent particles (B), followed by centrifugation and the supernatant was removed. Cyclohexane was further added to the precipitate to disperse the curing agent particles (B), followed by centrifugation and the supernatant was removed. The curing agent particles (B) were then separated by vacuum drying at room temperature for 24 hours. The solvent was selected from aromatic compounds, namely toluene, xylene, and trimethylbenzene, which are compatible with the epoxy resin but insoluble in the curing agent particles (B). When the separated curing agent particles (B) contained other particles, the curing agent particles (B) were dissolved in a solvent in which only the curing agent particles (B) were dissolved, and the other particles were then filtered off, and the solvent was distilled off, thereby separating the curing agent (B).

[0098] <Method for Measuring Total Amine Value> The total amine value is the amount of perchloric acid and the equivalent amount of potassium hydroxide required to neutralize all basic nitrogen contained in 1 g of curing agent particles, expressed in mg. It was determined using the following procedure. 0.2 g of curing agent particles was dissolved in 4.0 g of a 1:1 mixed solution of toluene and butanol. 50.0 mL of acetic acid and 20 mL of acetone were added to 1.0 g of the resulting solution, stirred with a stirrer, and titrated with a 0.1 mol perchloric acid / acetic acid solution using a glass electrode and a reference electrode. The relationship between the readings on the potentiometer or pH meter and the corresponding titration amount of the 0.1 mol / L perchloric acid / acetic acid solution was plotted, and the inflection point on the titration curve was taken as the endpoint. The total amine value was calculated from the amount of 0.1 mol / L perchloric acid / acetic acid solution consumed.

[0099] <Measurement of Tertiary Amine Value> The tertiary amine value is the amount of perchloric acid and the equivalent amount of potassium hydroxide required to neutralize the nitrogen corresponding to the tertiary amine contained in 1 g of curing agent particles (B), expressed in mg. It was determined using the following procedure. 0.5 g of curing agent particles was dissolved in 4.0 g of a 1:1 mixed solution of toluene and butanol. 10.0 mL of acetic acid and 10.0 mL of acetic anhydride were added to 1.0 g of the prepared solution, stirred, and allowed to stand at room temperature for 30 minutes to amidate the primary and secondary amino groups. The solution was then titrated with a 0.1 mol perchloric acid / acetic acid solution using a glass electrode and a reference electrode. The relationship between the potentiometer or pH meter reading and the corresponding titration amount of the 0.1 mol / L perchloric acid / acetic acid solution was plotted, and the inflection point on the titration curve was taken as the endpoint. The tertiary amine value was calculated based on the amount of 0.1 mol / L perchloric acid / acetic acid solution consumed.

[0100] [Particle size D50 and specific surface area value (Y) of curing agent particles (B)] <Measurement of particle size D50 of curing agent particles (B)> A HORIBA LA-920 (HORIBA LA-920 particle size distribution analyzer manufactured by HORIBA, Ltd.) was used as a particle size distribution analyzer. Specifically, 4 mg of curing agent particle powder was precisely weighed and added to 32 g of a cyclohexane solution of 0.1 mass % surfactant (Aerosol OT-75 manufactured by Mitsui Cytec Co., Ltd.), and dispersed by irradiation with ultrasonic waves for 5 minutes in an ultrasonic cleaner (Model W-211 manufactured by Honda Electronics Co., Ltd.). The water temperature in the ultrasonic cleaner was adjusted to 19±2°C. A portion of the resulting dispersion was taken and subjected to particle size distribution measurement using a HORIBA LA-920 (Horiba Ltd., particle size distribution analyzer HORIBA LA-920), and the target particle size D50 (μm) was measured based on this.

[0101] <Measurement of specific surface area of ​​curing agent particles (B)> The specific surface area (m ２ / g) was measured using a fully automatic BET specific surface area measuring device HM model-1201 manufactured by Mountech Co., Ltd. ２ A mixed gas of HCl / He=30 / 70 (volume ratio) was used as the adsorbed gas for the measurement.

[0102] [UV Transmittance] A sample for UV measurement was prepared by dissolving 1.0 g of curing agent particles in 99.0 g of DMF, and the transmittance at a wavelength of 365 nm was calculated from an absorbance chart measured using a UV-Visible-Near-Infrared Spectrophotometer V-660 (manufactured by JASCO). The optical path length of the cell used was 5 mm. (Measurement conditions) Measurement mode: abs Scanning speed: 400 nm Measurement wavelength: 300 nm to 800 nm Reference solvent: DMF

[0103] <Production Example of Curing Agent Particles (B-1)> One equivalent of epoxy resin (C-1) and two equivalents of amine compound (D-1) were reacted in a 1:1 mixed solvent of n-butanol and toluene under a nitrogen atmosphere at 70°C. Next, the internal temperature was raised to 130°C, and the pressure was reduced from the nitrogen atmosphere to 7.5 Torr. Thereafter, the internal temperature was raised to 180°C, and the solvent and unreacted amine compound (D-1) were distilled off. The distillation was terminated when the amine compound (D-1) reached 0.5% by mass, yielding a solid block curing agent 1 at 25°C. The obtained block curing agent 1 was crushed using a crusher "Rotoplex" (manufactured by Hosokawa Micron Corporation) to an average particle size of approximately 0.1 to 2 mm, yielding a coarse powder. The obtained coarsely crushed material was pulverized in an air jet mill (Nisshin Engineering, "CJ25 type") at a feed rate of 5.0 kg / Hr, and then classified using an air classifier (Nisshin Engineering, "Turbo Classifier") to remove coarse particles. Subsequently, using a Meteor Rainbow MR-10 manufactured by Nippon Pneumatic Co., Ltd., heat treatment was carried out under conditions of a curing agent particle feed rate of 2.0 kg / hr and a treatment temperature of 200°C, yielding solid curing agent particles (B-1) at 25°C. The content of amine compound (D-1) in the obtained curing agent particles (B-1) was 0.5% by mass. Various physical properties are shown in Table 4 below.

[0104] <Production Example of Curing Agent Particles (B-2)> 1 equivalent of epoxy resin (C-1) and 1.5 equivalents of amine compound (D-2) were reacted in a 1:1 mixed solvent of n-butanol and toluene under a nitrogen atmosphere at 70 ° C. Next, the internal temperature was raised to 130 ° C., and the pressure was reduced from a nitrogen atmosphere to 7.5 Torr. Thereafter, the internal temperature was raised to 180 ° C., and the solvent and unreacted amine compound (D-2) were distilled off. The distillation was terminated when the amine compound (D-2) reached 0.6% by mass. 82.0 g of the resulting reaction product was adjusted to an internal temperature of 165 ° C. under a nitrogen atmosphere, and 18.0 g of a low molecular weight amine compound (E-1) having a tertiary amino group was added. The mixture was stirred and mixed at an internal temperature of 165 ° C. for 1 hour, yielding a solid block curing agent 2 at 25 ° C. The obtained block-shaped curing agent 2 was crushed using a crusher "Rotoplex" (manufactured by Hosokawa Micron Corporation) until the average particle size was approximately 0.1 to 2 mm, resulting in a coarse powder. The resulting crushed material was pulverized using an air jet mill (manufactured by Nisshin Engineering, "CJ25 Model") at a feed rate of 5.0 kg / hr, and then classified using an air classifier (manufactured by Nisshin Engineering, "Turbo Classifier") to remove coarse particles. Subsequently, using a Meteor Rainbow MR-10 (manufactured by Nippon Pneumatic Co., Ltd.), heat treatment was carried out at a feed rate of 2.0 kg / hr and a treatment temperature of 150°C, yielding solid curing agent particles (B-2) at 25°C. The content of amine compound (D-2) in the obtained curing agent particles (B-2) was 0.5% by mass. Other physical properties are shown in Table 4 below.

[0105] <Production Example of Curing Agent Particles (B-3)> Curing agent particles (B-3) were obtained in the same manner as in the Production Example of Curing Agent Particles (B-2), except that amine compound (D-2) was changed to amine compound (D-3) and low molecular weight amine compound (E-1) having a tertiary amino group was changed to low molecular weight amine compound (E-2) having a tertiary amino group. The physical properties are shown in Table 4 below.

[0106] <Production Example of Curing Agent Particles (B-4)> Curing agent particles (B-4) were obtained in the same manner as in the production example of curing agent particles (B-1), except that the treatment with Meteor Rainbow MR-10 manufactured by Nippon Pneumatic Co., Ltd. was not carried out. The physical properties are shown in Table 4 below.

[0107] <Production Example of Curing Agent Particles (B-5)> One equivalent of epoxy resin (C-1) and two equivalents of amine compound (D-2) were reacted in a 1:1 mixed solvent of n-butanol and toluene under a nitrogen atmosphere at 70°C. Next, the internal temperature was raised to 130°C, and the pressure was reduced from the nitrogen atmosphere to 7.5 Torr. Thereafter, the internal temperature was raised to 180°C, and the solvent and unreacted amine compound (D-2) were distilled off. The distillation was terminated when the amine compound (D-2) reached 0.9% by mass, yielding a solid block curing agent 5 at 25°C. The obtained block curing agent 5 was crushed using a crusher "Rotoplex" (manufactured by Hosokawa Micron Corporation) to an average particle size of approximately 0.1 to 2 mm, yielding a coarse powder. The obtained coarsely crushed material was pulverized in an air jet mill (manufactured by Nisshin Engineering, "CJ25 type") at a feed rate of 5.0 kg / Hr, and classified using an air classifier (manufactured by Nisshin Engineering, "Turbo Classifier") to remove coarse particles, thereby obtaining curing agent particles (B-5) that were solid at 25°C. The content of amine compound (D-2) in the obtained curing agent particles (B-5) was 0.9 mass%. Various physical properties are shown in Table 4 below.

[0108] <Production Example of Curing Agent Particles (B-6)> 1 equivalent of epoxy resin (C-1) and 1.5 equivalents of amine compound (D-3) were reacted in a 1:1 mixed solvent of n-butanol and toluene under a nitrogen atmosphere at 70°C. Next, the internal temperature was raised to 130°C, and the pressure was reduced from the nitrogen atmosphere to 7.5 Torr. Thereafter, the internal temperature was raised to 180°C, and the solvent and unreacted amine compound (D-3) were distilled off. The distillation was terminated when the amine compound (D-3) reached 2.3% by mass. 82.0 g of the resulting reaction product was adjusted to an internal temperature of 165°C under a nitrogen atmosphere, and 18.0 g of a low molecular weight amine compound (E-1) having a tertiary amino group was added. The mixture was stirred and mixed at an internal temperature of 165°C for 1 hour while maintaining the nitrogen atmosphere, yielding a solid block curing agent 6 at 25°C. The obtained block curing agent 6 was coarsely crushed using a crusher "Rotoplex" (manufactured by Hosokawa Micron Corporation) until the average particle size was approximately 0.1 to 2 mm, yielding a coarse powder. The obtained coarsely crushed material was pulverized using an air jet mill (manufactured by Nisshin Engineering, "CJ25 type") at a feed rate of 5.0 kg / Hr, and classified using an air classifier (manufactured by Nisshin Engineering, "Turbo Classifier") to remove coarse particles, yielding curing agent particles (B-6) that were solid at 25°C. The content of amine compound (D-3) in the obtained curing agent particles (B-6) was 1.9% by mass. Other physical properties are shown in Table 4 below.

[0109] <Production Example of Curing Agent Particles (B-7)> 1 equivalent of epoxy resin (C-1) and 1.5 equivalents of amine compound (D-1) were reacted in a 1:1 mixed solvent of n-butanol and toluene under a nitrogen atmosphere at 70°C. Next, the internal temperature was raised to 130°C, and the pressure was reduced from the nitrogen atmosphere to 7.5 Torr. Thereafter, the internal temperature was raised to 180°C, and the solvent and unreacted amine compound (D-1) were distilled off. The distillation was terminated when the amine compound (D-1) reached 3.5% by mass. 82.0 g of the resulting reaction product was adjusted to an internal temperature of 165°C under a nitrogen atmosphere, and 18.0 g of a low molecular weight amine compound (E-2) having a tertiary amino group was added. The mixture was stirred and mixed at an internal temperature of 165°C for 1 hour while maintaining the nitrogen atmosphere, yielding a solid block curing agent 7 at 25°C. The obtained block curing agent 7 was coarsely crushed using a crusher "Rotoplex" (manufactured by Hosokawa Micron Corporation) until the average particle size was approximately 0.1 to 2 mm, yielding a coarse powder. The obtained coarsely crushed material was pulverized using an air jet mill (manufactured by Nisshin Engineering, "CJ25 model") at a feed rate of 5.0 kg / Hr, and classified using an air classifier (manufactured by Nisshin Engineering, "Turbo Classifier") to remove coarse particles, yielding curing agent particles (B-7) that were solid at 25°C. The content of amine compound (D-1) in the obtained curing agent particles (B-7) was 2.9% by mass. Other physical properties are shown in Table 4 below.

[0110] <Production Example of Curing Agent Particles (B-8)> One equivalent of epoxy resin (C-1) and two equivalents of amine compound (D-2) were reacted in a 1:1 mixed solvent of n-butanol and toluene under a nitrogen atmosphere at 70°C. Next, the internal temperature was raised to 130°C, and the pressure was reduced from the nitrogen atmosphere to 7.5 Torr. Thereafter, the internal temperature was raised to 180°C, and the solvent and unreacted amine compound (D-2) were distilled off. The distillation was terminated when the amine compound (D-2) reached 3.1% by mass, yielding a solid block curing agent 8 at 25°C. The obtained block curing agent 8 was crushed using a crusher "Rotoplex" (manufactured by Hosokawa Micron Corporation) to an average particle size of approximately 0.1 to 2 mm, yielding a coarse powder. The obtained coarsely crushed material was pulverized in an air jet mill (manufactured by Nisshin Engineering, "CJ25 type") at a feed rate of 5.0 kg / Hr, and classified using an air classifier (manufactured by Nisshin Engineering, "Turbo Classifier") to remove coarse particles, thereby obtaining curing agent particles (B-8) that were solid at 25°C. The content of amine compound (D-2) in the obtained curing agent particles (B-8) was 3.1 mass%. Various physical properties are shown in Table 4 below.

[0111] <Production Example of Curing Agent Particles (B-9)> Curing agent particles (B-9) were obtained in the same manner as in the Production Example of Curing Agent Particles (B-8), except that amine compound (D-2) was changed to amine compound (D-4). The physical properties are shown in Table 4 below.

[0112] <Production Example of Curing Agent Particles (B-10)> 1 equivalent of epoxy resin (C-1) and 1.5 equivalents of amine compound (D-4) were reacted at 70°C in a 1:1 mixed solvent of n-butanol and toluene under a nitrogen atmosphere. Next, the internal temperature was raised to 130°C, and the pressure was reduced from the nitrogen atmosphere to 7.5 Torr. Thereafter, the internal temperature was raised to 180°C, and the solvent and unreacted amine compound (D-4) were distilled off. The distillation was terminated when the amine compound (D-4) reached 3.8% by mass. 82.0 g of the resulting reaction product was heated to an internal temperature of 165°C under a nitrogen atmosphere, and 18.0 g of a low molecular weight amine compound (E-2) having a tertiary amino group was added. The mixture was stirred and mixed at an internal temperature of 165°C for 1 hour while maintaining the nitrogen atmosphere, yielding a solid block curing agent 10 at 25°C. The obtained block curing agent 10 was coarsely crushed using a crusher "Rotoplex" (manufactured by Hosokawa Micron Corporation) until the average particle size was approximately 0.1 to 2 mm, yielding a coarse powder. The obtained coarsely crushed material was pulverized using an air jet mill (manufactured by Nisshin Engineering, "CJ25 model") at a feed rate of 5.0 kg / Hr, and classified using an air classifier (manufactured by Nisshin Engineering, "Turbo Classifier") to remove coarse particles, yielding curing agent particles (B-10) that were solid at 25°C. The content of amine compound (D-4) in the obtained curing agent particles (B-10) was 3.1% by mass. Other physical properties are shown in Table 4 below.

[0113] <Production Example of Curing Agent Particles (B-11)> Curing agent particles (B-11) were obtained in the same manner as in the production example of curing agent particles (B-8), except that amine compound (D-2) was changed to amine compound (D-5). The physical properties are shown in Table 4 below.

[0114] <Production Example of Curing Agent Particles (B-12)> Curing agent particles (B-12) were obtained in the same manner as in the Production Example of Curing Agent Particles (B-8), except that amine compound (D-2) was changed to amine compound (D-6). The physical properties are shown in Table 4 below.

[0115] <Production Example of Curing Agent Particles (B-13)> Curing agent particles (B-13) were obtained in the same manner as in the production example of curing agent particles (B-10), except that amine compound (D-4) was changed to amine compound (D-6). The physical properties are shown in Table 4 below.

[0116] <Production Example of Curing Agent Particles (B-14)> Curing agent particles (B-14) were obtained in the same manner as in the production example of curing agent particles (B-8), except that amine compound (D-2) was changed to amine compound (D-7). The physical properties are shown in Table 4 below.

[0117] <Production Example of Curing Agent Particles (B-15)> Curing agent particles (B-15) were obtained in the same manner as in the Production Example of Curing Agent Particles (B-10), except that amine compound (D-4) was changed to amine compound (D-7). The physical properties are shown in Table 4 below.

[0118] <Production Example of Curing Agent Particles (B-16)> Curing agent particles (B-16) were obtained in the same manner as in the Production Example of Curing Agent Particles (B-8), except that 2 equivalents of amine compound (D-2) were replaced with 1 equivalent of amine compound (D-8). The physical properties are shown in Table 4 below.

[0119] <Production Example of Curing Agent Particles (B-17)> Curing agent particles (B-17) were obtained in the same manner as in the Production Example of Curing Agent Particles (B-1), except that amine compound (D-1) was changed to amine compound (D-3). The physical properties are shown in Table 4 below.

[0120] <Production Example of Curing Agent Particles (B-18)> Curing agent particles (B-18) were obtained in the same manner as in the Production Example of Curing Agent Particles (B-1), except that 2 equivalents of amine compound (D-1) were changed to 0.75 equivalents of amine compound (D-3). The physical properties are shown in Table 4 below.

[0121] <Production Example of Curing Agent Particles (B-19)> Curing agent particles (B-19) were obtained in the same manner as in the Production Example of Curing Agent Particles (B-1), except that 2 equivalents of amine compound (D-1) were changed to 0.7 equivalents of amine compound (D-3). The physical properties are shown in Table 4 below.

[0122] <Production Example of Curing Agent Particles (B-20)> 1 equivalent of epoxy resin (C-1) and 0.7 equivalents of amine compound (D-9) were reacted at 70°C in a 1:1 mixed solvent of n-butanol and toluene. Next, the internal temperature was raised to 180°C, and stirring was continued for 1 hour. Thereafter, the pressure was reduced from the atmospheric pressure to 7.5 Torr, and the solvent and unreacted amine compound (D-1) were distilled off at an internal temperature of 180°C. The distillation was terminated when the amine compound (D-1) reached 0.5% by mass, yielding a solid block curing agent 1 at 25°C. The obtained block curing agent 1 was crushed using a crusher "Rotoplex" (manufactured by Hosokawa Micron Corporation) to an average particle size of approximately 0.1 to 2 mm, yielding a coarse powder. The obtained coarsely crushed material was pulverized in an air jet mill (Nisshin Engineering, "CJ25 type") at a feed rate of 5.0 kg / Hr, and then classified using an air classifier (Nisshin Engineering, "Turbo Classifier") to remove coarse particles. Subsequently, using a Meteor Rainbow MR-10 manufactured by Nippon Pneumatic Co., Ltd., heat treatment was carried out under conditions of a curing agent particle feed rate of 2.0 kg / hr and a treatment temperature of 200°C, yielding solid curing agent particles (B-1) at 25°C. The content of amine compound (D-1) in the obtained curing agent particles (B-1) was 0.5% by mass. Various physical properties are shown in Table 4 below.

[0123] <Production Example of Curing Agent Particles (B-21)> Curing agent particles (B-21) were obtained in the same manner as in the Production Example of Curing Agent Particles (B-20), except that 0.7 equivalents of amine compound (D-9) was changed to 0.75 equivalents of amine compound (D-3). The physical properties are shown in Table 4 below.

[0124] <Production Example of Curing Agent Particles (B-22)> Curing agent particles (B-22) were obtained in the same manner as in the Production Example of Curing Agent Particles (B-20), except that 0.7 equivalents of amine compound (D-9) was changed to 0.75 equivalents of amine compound (D-3) and the mixing time at an internal temperature of 180°C was changed from 1 hour to 0.5 hour. The physical properties are shown in Table 4 below.

[0125] <Production Example of Curing Agent Particles (B-23)> Curing agent particles (B-23) were obtained in the same manner as in the Production Example of Curing Agent Particles (B-20), except that 0.7 equivalents of amine compound (D-9) was changed to 0.75 equivalents of amine compound (D-3) and the mixing time at an internal temperature of 180°C was changed from 1 hour to 0 hour. The physical properties are shown in Table 4 below.

[0126]

[0127] (Thiol Compounds (F-1) to (F-2)) The thiol compounds used in the examples and comparative examples described later are shown in Table 5 below.

[0128]

[0129] [Preparation of Epoxy Resin Composition] Example 1 31.25 parts by mass of epoxy resin (A-1), 31.25 parts by mass of epoxy resin (A-2), 37.5 parts by mass of curing agent particles (B-1), 1.0 part by mass of encapsulating agent (MR-200 manufactured by Nippon Polyurethane Co., Ltd.), and 0.5 parts by mass of distilled water were added and dispersed and mixed, and then reacted at 25°C to 45°C for 2 hours to obtain an epoxy resin composition (G-1) containing an encapsulated curing agent. The obtained epoxy resin composition was used to perform the following evaluations. The composition of the epoxy resin composition is shown in Table 6 below, and the obtained evaluation results are shown in Table 7 below.

[0130] Examples 2 to 19, Examples 21 to 23, Comparative Example 1 Epoxy resin compositions (G-2) to (G-19), (G-21) to (G-22), and (G-26) to (G-27) were obtained in the same manner as in Example 1, except for the formulations shown in Table 6 below. The configurations of the epoxy resin compositions obtained in the same manner as in Example 1 are shown in Table 6 below, and the evaluation results obtained are shown in Table 7 below.

[0131] Example 20 31.25 parts by mass of epoxy resin (A-1), 31.25 parts by mass of epoxy resin (A-2), and 37.5 parts by mass of curing agent particles (B-6) were dispersed and mixed to obtain an epoxy resin composition (G-20).

[0132] Comparative Example 2 31.25 parts by mass of epoxy resin (A-1), 31.25 parts by mass of epoxy resin (A-2), and 37.5 parts by mass of curing agent particles (B-16) were dispersed and mixed to obtain an epoxy resin composition (G-28).

[0133] [Evaluation] <Adhesive Strength> Test specimens of epoxy resin compositions (G-1) to (G-22), (G-26) to (G-28) were prepared in accordance with JIS K6850. The adherends (cold-rolled copper plates) conforming to JIS C3141 and measuring 25 mm wide, 100 mm long, and 1.6 mm thick were used. Uncured test specimens were placed in a small, high-temperature chamber (ST-110B2, manufactured by ESPEC Corporation) with a stable internal temperature of 80°C and heated for 1 hour. After heating, the test specimens were left in a room-temperature environment and allowed to cool to room temperature, yielding test specimens for adhesive strength measurement. Using an autograph tester (AGX-5kNX, manufactured by Shimadzu Corporation), the maximum load at which the adhesive surface of the test specimen broke and the test specimen separated was measured at a speed of 5 mm / min using a load cell of 5 kN. The maximum load at which the test specimen separated was divided by the adhesive area to determine the adhesive strength. A rank of A to B was considered acceptable. [Evaluation Criteria] A: Adhesion strength is 10.0 MPa or more. B: Adhesion strength is 8.0 MPa or more and less than 10.0 MPa. C: Adhesion strength is 6.0 MPa or more and less than 8.0 MPa. D: Adhesion strength is less than 6.0 MPa.

[0134] <Decrease in Adhesive Strength After Storage in a Humid Heat Environment> Test pieces for measuring adhesive strength were prepared in the same manner as in the measurement of adhesive strength described above, and the test pieces were stored in an environment at a temperature of 85°C and a humidity of 85%. One week after the start of storage, the test pieces were removed and stored in an environment at a temperature of 25°C and a humidity of 50% for one day. The adhesive strength of the test pieces was then measured, and the decrease in adhesive strength (%) was calculated using the following formula (4): Decrease in adhesive strength (%) = {1 - (Adhesive strength after storage in a humid heat environment / Adhesive strength before storage in a humid heat environment)} x 100 Formula (4) Ranks A to B were considered to be pass. [Evaluation Criteria] A: The decrease in adhesive strength was less than 10.0%. B: The decrease in adhesive strength was 10.0% or more and less than 20.0%. C: The decrease in adhesive strength was 20.0% or more and less than 30.0%. D: The decrease in adhesive strength was less than 30.0%.

[0135] <Tg of Cured Product> Epoxy resin compositions (G-1) to (G-22), (G-26) to (G-28) were uniformly applied to a 20 cm square, 0.2 mm thick aluminum plate to a thickness of 100 μm or more but less than 300 μm, and then cured by heating in an oven at 80°C for 60 minutes to obtain a cured product. The resulting cured product was carefully peeled off and cut into thin pieces of cured product samples measuring 5 mm wide and 25 mm long. Using this cured product sample, measurements were performed using a dynamic viscoelasticity measuring device "RHEOVIBRON DDV-25FP" manufactured by Orientec Co., Ltd. in tensile mode, at a frequency of 1 Hz, and at a heating rate of 2°C / min. The peak tan δ was recorded as the Tg of epoxy resin compositions (G-1) to (G-22), (G-26) to (G-28). Ranks A to C were considered acceptable. [Evaluation Criteria] A: The Tg of the cured product was 90°C or higher. B: The Tg of the cured product is 80° C. or higher and lower than 90° C. C: The Tg of the cured product is 70° C. or higher and lower than 80° C. D: The Tg of the cured product is lower than 70° C.

[0136] <Gel Time> Using a Curastometer (registered trademark) (Curastometer (registered trademark) V, manufactured by TS Engineering Co., Ltd.), the gel times of epoxy resin compositions (G-1) to (G-22) and (G-26) to (G-28) were measured at a set temperature of 80°C, and a torque-vulcanization time chart was obtained. For the obtained chart, the points where the torque reached 1 N m and the point where the torque reached 0.5 N m were determined, and the time at which a line passing through these two points intersected the vulcanization time axis was defined as the gel time, and the gel time value was calculated. Ranks A to C were rated as passing. [Evaluation Criteria] A: The gel time was less than 4.0 minutes. B: The gel time was 4.0 minutes or more but less than 6.0 minutes. C: The gel time was 6.0 minutes or more but less than 8.0 minutes. D: The gel time was 8.0 minutes or more.

[0137] <Storage Stability (Thickening Ratio)> The initial viscosity of each of the epoxy resin compositions (G-1) to (G-22), (G-26) to (G-28) immediately after preparation and the viscosity of each of the epoxy resin compositions (G-1) to (G-22), (G-26) to (G-28) after standing at 40°C for 7 days were measured at room temperature (25°C) using an E-type viscometer. The viscosity increasing ratio was calculated using the following formula (5) to evaluate storage stability. Viscosity increasing ratio = Viscosity after standing at 40°C for 7 days / Initial viscosity Formula (5) Ranks A to B were rated as passing. [Evaluation Criteria] A: The viscosity increasing ratio was 1.0 times or more and less than 1.5 times. B: The viscosity increasing ratio was 1.5 times or more and less than 2.0 times. C: The viscosity increasing ratio was 2.0 times or more and less than 2.5 times. D: The viscosity increasing ratio was 2.5 times or more.

[0138] <Viscosity measurement of epoxy resin compositions> The stage temperature of an E-type viscometer (TVE-35H, manufactured by Toki Sangyo Co., Ltd.) was adjusted to 25°C, and 0.2 g of each of the epoxy resin compositions (G-1) to (G-22) and (G-26) to (G-28), which had been previously adjusted to 25°C, was placed on the stage and the viscosity was measured. Ranks A to B were rated as passing. [Evaluation criteria] A: Viscosity less than 100 Pa s. B: Viscosity 100 Pa s or more and less than 300 Pa s. C: Viscosity 300 Pa s or more and less than 500 Pa s. D: Viscosity 500 Pa s or more.

[0139] <Cure Depth> 10 g of each of the epoxy resin compositions (G-1) to (G-22), (G-26) to (G-28), 10 g of A-DCP (manufactured by Shin-Nakamura Chemical Co., Ltd.), and 0.6 g of a 50 wt % MEK solution of 1-hydroxycyclohexyl phenyl ketone were placed in a plastic stirring vessel, and the mixture was stirred and mixed using a planetary centrifugal mixer ("ARE-310" manufactured by Thinky Corporation) to prepare a sample for cure depth measurement. Next, a 3 mm thick silicone rubber sheet with a 15 mm diameter circular hole was placed on a 10 cm square PET sheet, and the sample for cure depth measurement was poured into the hole in the silicone rubber sheet, and the sample height was adjusted to 3 mm. The sample for cure depth measurement poured into the silicone rubber sheet was illuminated with a 365 nm LED at 1000 mW / cm. ２The sample for measuring cure depth was cured by irradiating it under conditions of 1000 x 2 seconds. The cured sample was then removed from the silicone rubber sheet, and the uncured portion of the sample was wiped off. The height of the cured product was then measured to determine the cure depth. Ranks A to B were rated as passing. [Evaluation criteria] A: Cure depth is 2.0 mm or more. B: Cure depth is 1.5 mm or more but less than 2.0 mm. C: Cure depth is 1.0 mm or more but less than 1.5 mm. D: Cure depth is less than 1.0 mm.

[0140] <Residual heat release amount measured by differential scanning calorimetry (DSC)> The epoxy resin compositions obtained in the Examples and Comparative Examples immediately after blending were measured from 25 to 250°C at 10°C / min using a DSC measuring device, Q2000, manufactured by TA Instruments, and the total heat release amount obtained was defined as 100%. The above epoxy resin compositions were cured at 80°C for 1 hour, and the cured products were measured under the same conditions. The percentage of the total heat release amount was calculated and defined as the residual heat release amount (%).

[0141] <Crack Resistance> A 2 mm thick U-shaped Teflon (registered trademark) mold was sandwiched between two aluminum plates, and the epoxy resin compositions of the Examples and Comparative Examples described below were poured into it. The mixture was then placed in an oven at 80°C for 1 hour to obtain a cured product. The cured product was then cut into a size of 2 mm x 4 mm x 20 mm. With the 2 mm x 20 mm side facing up, a razor blade was placed parallel to the 2 mm side at the center of the 20 mm side, and the razor blade was struck from above with a hammer to create a 1.8 to 2.2 mm crack in the cured product. A load was applied from above with the cracked side facing downwards, with a support distance of 20 mm, and the maximum point test force P was measured. The crack length a, test piece height W, and test piece thickness B were used to calculate K using the following mathematical formula (I): １ｃ The unit of the test force P is MPa, and the units of the lengths a, W, and B are each m.

[0142]

[0143] The desired K １ｃ The values ​​were evaluated according to the following criteria. A to B ranks were considered to be acceptable. [Evaluation criteria] A: 1.5 or more B: 1.2 or more, less than 1.5 C: 1.0 or more, less than 1.2 D: Less than 1.0

[0144]

[0145]

[0146] Example 24 100 parts by mass of epoxy resin (A-3), 65 parts by mass of thiol compound (F-1), and 5 parts by mass of epoxy resin composition (G-2) were stirred at 25°C for 5 minutes or more to obtain epoxy resin composition (G-23). ​​The obtained epoxy resin composition was used to perform the following evaluations. The obtained results are shown in Table 8 below.

[0147] Example 25 100 parts by mass of epoxy resin (A-3), 65 parts by mass of thiol compound (F-2), and 5 parts by mass of epoxy resin composition (G-3) were stirred at 25°C for 5 minutes or more to obtain epoxy resin composition (G-24). The obtained epoxy resin composition was used to perform the following evaluations. The obtained results are shown in Table 8 below.

[0148] Comparative Example 3 100 parts by mass of epoxy resin (A-3), 65 parts by mass of thiol compound (F-1), and 5 parts by mass of epoxy resin composition (G-27) were stirred at 25°C for 5 minutes or more to obtain epoxy resin composition (G-25). The obtained epoxy resin composition was used to perform the following evaluations. The obtained results are shown in Table 8 below.

[0149] [Evaluation] <Gel Time> Using a Curastometer (registered trademark, Curastometer V, manufactured by TS Engineering Co., Ltd.), the gel times of epoxy resin compositions (G-23) to (G-25) were measured at a set temperature of 60°C, and a torque-vulcanization time chart was obtained. For the obtained chart, the points at which the torque reached 1 N m and the points at which the torque reached 0.5 N m were determined, and the time at which a line passing through these two points intersected the vulcanization time axis was defined as the gel time, and the gel time value was calculated. Ranks A to B were considered to be acceptable. [Evaluation Criteria] A: Gel time is less than 6.0 minutes. B: Gel time is 6.0 minutes or more but less than 8.0 minutes. C: Gel time is 8.0 minutes or more but less than 10.0 minutes. D: Gel time is 10.0 minutes or more.

[0150] <Decrease in Adhesive Strength After Storage in a Humid Heat Environment> Test specimens of epoxy resin compositions (G-23) to (G-25) were prepared in accordance with JIS K6850. A 25 mm wide, 100 mm long, and 1.6 mm thick adherend (cold-rolled copper plate) conforming to JIS C3141 was used as the adherend. An uncured test specimen was placed in a small high-temperature chamber (ST-110B2, manufactured by ESPEC Corporation) with a stable internal temperature of 60°C and heated for 30 minutes. The heated test specimen was then left in a room temperature environment and allowed to cool to room temperature, yielding a test specimen for adhesive strength measurement. The test specimen was stored in an environment with a temperature of 85°C and humidity of 85%. After one week of storage, the test specimen was removed and stored in an environment with a temperature of 25°C and humidity of 50% for one day. The adhesive strength of the test specimen was then measured, and the decrease in adhesive strength (%) was calculated using the following formula (4): Decrease in adhesive strength (%) = {1 - (adhesive strength after storage in humid and hot environment / adhesive strength before storage in humid and hot environment)} x 100 Equation (4) Ranks A to B were considered to be acceptable. [Evaluation criteria] A: Adhesive strength is less than 20.0%. B: Adhesive strength is 20.0% or more and less than 30.0%. C: Adhesive strength is 30.0% or more and less than 40.0%. D: Adhesive strength is less than 40.0%.

[0151]

[0152] This application is based on a Japanese patent application (Patent Application No. 2023-150966) filed with the Japan Patent Office on September 19, 2023, the contents of which are incorporated herein by reference.

[0153] The epoxy resin composition of the present invention has industrial applicability as an adhesive or sealing material for various electronic components.

Claims

1. An epoxy resin composition comprising an epoxy resin (A) and a curing agent (B), wherein, when the total amine value of the curing agent (B) is (a) and the tertiary amine value is (b), the values ​​of (a) and (b) satisfy the following relational expression (1): (a)-(b)≧5.0...(1) 2. The epoxy resin composition according to claim 1, wherein the curing agent (B) has a light transmittance of 50.0% or more at a wavelength of 365 nm as measured by ultraviolet-visible spectroscopy when dissolved in a 1.0% by mass dimethylformamide (DMF) solution.

3. The epoxy resin composition according to claim 1, wherein the viscosity of the epoxy resin composition is 10.0 Pa·s or more and 800.0 Pa·s or less at 25°C.

4. The epoxy resin composition according to claim 1, wherein the curing agent (B) comprises at least one reaction product of an epoxy resin (C) and an amine compound (D).

5. The epoxy resin composition according to claim 4, wherein the amine compound (D) is an aromatic amine compound or an alicyclic amine compound.

6. The epoxy resin composition according to claim 4, wherein the amine compound (D) is an alicyclic amine compound.

7. The epoxy resin composition according to claim 1, wherein the curing agent (B) is a curing agent particle.

8. An epoxy resin composition comprising an epoxy resin (A) and hardener particles (B-1), wherein the hardener particles (B-1) have a total amine value of (a) and a tertiary amine value of (b), and the values ​​of (a) and (b) satisfy the following relational expression (1): (a) - (b) ≧ 5.0 ... (1). The hardener particles (B-1) contain at least one reaction product of an epoxy resin (C) and an alicyclic amine compound (D), and the hardener particles (B-1) have a light transmittance of 50.0% or more at a wavelength of 365 nm when measured by ultraviolet-visible spectroscopy when dissolved in a 1.0 mass% dimethylformamide (DMF).

9. The epoxy resin composition according to claim 1, wherein the curing agent (B) satisfies the following conditions (i) to (iii): (i) it is a curing agent particle; (ii) when it is dissolved in 1.0 mass % dimethylformamide (DMF), the light transmittance at a wavelength of 365 nm by ultraviolet-visible spectroscopy is 50.0% or more; and (iii) it contains at least one reaction product of an epoxy resin (C) and an amine compound (D), and the amine compound (D) is an alicyclic amine.

10. The epoxy resin composition according to claim 4, wherein the amine compound (D) is 1,3-bis(aminomethyl)cyclohexane.

11. The epoxy resin composition according to claim 1, wherein the curing agent (B) satisfies the following conditions (i), (ii), and (iv): (i) it is a curing agent particle; (ii) when it is dissolved in 1.0% by mass of dimethylformamide (DMF), the light transmittance at a wavelength of 360 nm by ultraviolet-visible spectroscopy is 50.0% or more; and (iv) it contains at least one reaction product of an epoxy resin (C) and an amine compound (D), and the amine compound (D) is 1,3-bis(aminomethyl)cyclohexane.

12. The epoxy resin composition according to claim 4, wherein the content of the amine compound (D) in the curing agent (B) is 0.000001% by mass or more and 3.0% by mass or less.

13. The specific surface area of ​​the curing agent (B), which is the curing agent particle, is (Y) (m ２ 8. The epoxy resin composition according to claim 7, wherein the values ​​of (X) and (Y) satisfy the following relational formula (2), where (X) is a particle diameter D50 at an integrated undersize fraction of 50% and (X) is a particle diameter D50 at an integrated undersize fraction of 50% (μm). -１ ≦(Y) ≦8.3(X) -１ ...(2) 14. The epoxy resin composition according to claim 1, wherein the content of the curing agent (B) in the epoxy resin composition is 5.0 mass % or more and 65.0 mass % or less based on the total amount of the epoxy resin (A) and the curing agent (B).

15. The epoxy resin composition according to claim 7, wherein the hardener particles (B) are capsule-type hardeners in which the surface of a core particle is covered with a shell.

16. The epoxy resin composition according to claim 1, wherein the curing agent (B) satisfies the following conditions (i), (ii), (iv), and (v): (i) it is a curing agent particle; (ii) when it is prepared as a 1.0 mass% dimethylformamide (DMF) solution, the light transmittance at a wavelength of 365 nm by ultraviolet-visible spectroscopy is 50.0% or more; (iv) it contains at least one reaction product of an epoxy resin (C) and an amine compound (D), and the amine compound (D) is 1,3-bis(aminomethyl)cyclohexane; and (v) it is a capsule-type curing agent in which the surface of a core particle is covered with a shell.

17. The epoxy resin composition according to claim 1, wherein the total heat generation amount of the epoxy resin composition measured by a differential scanning calorimeter (DSC) is (c), and the total heat generation amount of a cured product obtained by curing the epoxy resin composition at 80°C for 60 minutes measured by a differential scanning calorimeter (DSC) is (d), and the values ​​of (c) and (d) satisfy the following relational formula (3): (d) / (c)×100≦20.0...(3) 18. The epoxy resin composition according to claim 1, wherein the curing agent (B) contains a low molecular weight amine compound (E) having a tertiary amino group and a molecular weight of 1,000 or less.

19. The epoxy resin composition according to claim 18, wherein the low molecular weight amine compound (E) having a tertiary amino group is 1,4-diazabicyclo[2.2.2]octane or (1,4-diazabicyclo[2.2.2]octan-2-yl)methanol.

20. The epoxy resin composition according to claim 18, further comprising a thiol compound (F).

21. An encapsulant comprising the epoxy resin composition according to any one of claims 1 to 20.

22. An adhesive comprising the epoxy resin composition according to any one of claims 1 to 20.

23. A camera module comprising the epoxy resin composition according to any one of claims 1 to 20.

24. A semiconductor package comprising the epoxy resin composition according to any one of claims 1 to 20.

25. An electronic device comprising the epoxy resin composition according to any one of claims 1 to 20.

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