Epoxy resin composition, resin paste, resin film, and semiconductor device

Abstract

This epoxy resin composition contains a component (A) that is an epoxy resin, and a component (B) that is a compound represented by the specific formula (1) and / or a compound represented by the specific formula (2), wherein the component (A) contains at least one type of trifunctional or greater polyfunctional epoxy resin, and assuming that it takes t minutes for the viscosity to reach 10,000 Pa·s after the temperature has reached T°C, the slope α of a straight line obtained by plotting Lnt (vertical axis) with respect to 1 / T (horizontal axis) satisfies 690 ≤ α ≤ 1000.

Description

Epoxy resin composition, resin paste, resin film, and semiconductor device

[0001] The present invention relates to an epoxy resin composition, a resin paste, a resin film, and a semiconductor device.

[0002] Epoxy resins have traditionally been used in a wide range of applications, such as insulating materials for electrical and electronic components including semiconductor elements, sealing materials, adhesives, conductive materials, matrix resins for fiber-reinforced plastics, and impregnating and fixing agents for motor coils.

[0003] Among these, epoxy resin compositions, which have excellent adhesive properties and high reliability, are used as sealing materials and adhesives for semiconductor devices. The components of such epoxy resin compositions generally include, for example, an epoxy resin, a curing agent such as a phenolic resin reactive with the epoxy resin, and a curing accelerator that accelerates the reaction between the epoxy resin and the curing agent.

[0004] In recent years, as electronic devices have become more highly integrated, the pitch and gap of solder joints in semiconductor devices have become increasingly narrow. Furthermore, as the area of ​​each semiconductor chip has also increased, semiconductor device encapsulants require resin pastes that can penetrate and fill narrow gaps, and resin films that can encapsulate and bond entire large-area chips at once. Furthermore, as the density of electronic components increases and the amount of electronic information handled increases, the amount of heat generated by semiconductor devices increases. Therefore, encapsulants and adhesives used in these semiconductor devices are required to have not only a high glass transition temperature but also a small decrease in elastic modulus at high temperatures above the glass transition temperature. This is because a large difference in elastic modulus between room temperature and above the glass transition temperature can significantly change the physical properties of the cured layer when the electronic device generates heat, which tends to reduce the reliability of sealing and bonding.

[0005] Meanwhile, in memory packages for electronic devices such as mobile phones, the adoption of stacked MCPs (Multi-Chip Packages), in which semiconductor chips are stacked in multiple layers, is increasing. Resin films are primarily used to bond the circuit board and semiconductor chips in stacked MCPs, as well as to bond semiconductor chips themselves, due to their uniform thickness and the fact that they are less likely to tilt. Even for such resin films, thinner films are required to achieve miniaturization and higher integration. Furthermore, as the amount of heat generated by semiconductor chips increases with the miniaturization and higher density of wiring, there is a demand for films that have a high glass transition temperature and that suppress the decrease in elastic modulus at high temperatures, as described above.

[0006] As an encapsulant or adhesive for semiconductor devices, for example, a paste-like resin composition composed of a trifunctional epoxy resin, a curing agent such as an aromatic amine, a filler, etc. is known as a material that is filled into the gap between various electronic components and a circuit board and then cured (see, for example, Patent Document 1). Furthermore, electrical connection and encapsulation can be simultaneously achieved by thermocompression bonding and curing a semiconductor chip pre-applied with a resin film to the circuit board. Examples of such materials include a film-type adhesive composed of a multifunctional epoxy resin, a curing agent such as imidazole, and a filler (see, for example, Patent Document 2). Furthermore, as a resin film for bonding semiconductor chips to circuit boards and semiconductor chips to each other, a film-type adhesive composed of a multifunctional epoxy resin, a curing agent such as imidazole, and a filler (see, for example, Patent Document 3). Meanwhile, regarding the stability and rapid curing of epoxy resin compositions, for example, a curable composition containing a curing agent for an anionic curable compound composed of an imidazole-based compound having a substituted phenyl group at the 2-position of the imidazole ring has been disclosed (see, for example, Patent Document 4). It is disclosed that such a curable composition can selectively cause a curing reaction of the epoxy resin in a high temperature range around 150° C., and also has excellent storage stability.

[0007] Japanese Patent No. 7103401 Japanese Patent No. 6536281 Japanese Patent No. 7178529 Japanese Patent Laid-Open No. 2016-29152

[0008] In general, to achieve a high glass transition temperature and suppress the decrease in elastic modulus at high temperatures, an effective method is to incorporate a trifunctional or higher polyfunctional epoxy resin (hereinafter also referred to simply as "polyfunctional epoxy resin") into an epoxy resin composition to increase the crosslink density of the cured layer, as disclosed in Patent Documents 1 to 3. However, the present inventors have confirmed that in the presence of a polyfunctional epoxy resin, the initial viscosity increase during heating is rapid, resulting in curing before the functional groups of the epoxy resin and curing agent have completely reacted, resulting in insufficient crosslink density, a lower than expected glass transition temperature, and a significant decrease in elastic modulus at high temperatures. With regard to glass transition temperature in particular, it has been difficult to achieve a glass transition temperature above the curing temperature even when a polyfunctional epoxy resin is incorporated, and there is room for improvement.

[0009] Furthermore, in the sealing and bonding of increasingly dense electronic components, uniformity is important for the epoxy resin composition used, and ideally, it does not contain solid-dispersion curing agents or curing accelerators. The use of these solid-dispersion curing agents leads to blockages, which impairs gap filling and makes it difficult to seal the entire semiconductor chip. In the case of a resin film, residual particles tend to remain when the film is thinned, impairing film-forming properties. Therefore, the solid-dispersion curing agents or curing accelerators used in Patent Documents 2 and 3 have the problem of being unable to meet the demands for denser sealing and bonding.

[0010] On the other hand, while the curing agent for anionic curing compounds disclosed in Patent Document 4 is shown to be able to achieve both storage stability and curability at high temperatures around 150°C, no clear formulation has been disclosed that satisfies both the high glass transition temperature and the suppression of reduction in elastic modulus at high temperatures required for applications such as sealing and adhesive materials for increasingly dense semiconductor devices, and there is still room for further study. In addition, the inventors' investigations have confirmed that the use of the curing agent for anionic curing compounds disclosed in Patent Document 4 alone poses a problem with filling ability. Filling ability is important for ensuring that the epoxy resin composition is distributed evenly throughout gaps and conforms to the shapes of individual semiconductor chips and electronic components when sealing or bonding electronic components. To achieve good filling ability, in addition to the aforementioned uniformity, it is necessary to ensure that the epoxy resin composition can maintain a low viscosity for a certain period of time when heated, for example, to 110°C to 130°C. A short period of time during which the low viscosity state can be maintained can result in poor filling, making it difficult to achieve reliable sealing or bonding.

[0011] In view of the above-mentioned problems of the prior art, an object of the present invention is to provide an epoxy resin composition which is completely uniform, has sufficient filling properties, and is capable of suppressing a decrease in elastic modulus at high temperatures in addition to a high glass transition temperature, even when a polyfunctional epoxy resin is blended therein.

[0012] As a result of extensive research, the present inventors have discovered that an epoxy resin composition containing a tri- or higher functional polyfunctional epoxy resin and an imidazole compound having a specific structure can be obtained by plotting Lnt (vertical axis) against 1 / T (horizontal axis) when the composition is maintained at a constant temperature T°C satisfying the condition 130≦T≦150, where t minutes is the time it takes for the viscosity to reach 10,000 Pa s, starting from the point at which the temperature T°C is reached, and the slope α of the line obtained satisfies 690≦α≦1,000, thereby providing an epoxy resin composition that is completely uniform and has sufficient filling properties, and that, when a polyfunctional epoxy resin is blended with the composition, not only has a remarkably high glass transition temperature that exceeds the curing temperature, but also is able to suppress a decrease in elastic modulus at high temperatures, thereby completing the present invention. Specifically, the present invention is as follows.

[0013] [1] An epoxy resin composition comprising: component (A): an epoxy resin; and component (B): a compound represented by the following formula (1) and / or a compound represented by the following formula (2), wherein component (A) comprises at least one polyfunctional epoxy resin having a functionality of three or more; and wherein, when the composition is maintained at a constant temperature T°C that satisfies 130≦T≦150, the slope α of the straight line obtained by plotting Lnt (vertical axis) against 1 / T (horizontal axis) satisfies 690≦α≦1000, where t is the time (minutes) until the viscosity reaches 10,000 Pa s, starting from the temperature T°C as a reference point when the composition is maintained at a constant temperature T°C that satisfies 130≦T≦150. (In formula (1), R １ , R ２ are each independently any one selected from the group consisting of a hydrogen atom, a hydroxyl group, a carboxy group, a cyano group, a nitro group, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, and a cycloalkyl group having 6 to 20 carbon atoms which may have a substituent; R １ , R ２ may be the same or different, and R １ , R ２ may be bonded to form a fused ring having no aromaticity, X is any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent, and a heteroarylalkyl group having 4 to 20 carbon atoms which may have a substituent, Y is any one selected from the group consisting of a hydrogen atom, a halogen atom, a hydroxyl group, a carboxy group, a cyano group, a nitro group, an alkyl group of 1 to 20 carbon atoms which may have a substituent, an alkoxy group of 1 to 20 carbon atoms which may have a substituent, an alkenyl group of 2 to 20 carbon atoms which may have a substituent, an aryl group of 6 to 20 carbon atoms which may have a substituent, an aryloxy group of 6 to 20 carbon atoms which may have a substituent, and an acyl group of 1 to 20 carbon atoms which may have a substituent; when there are multiple Ys, they may be the same or different, and two or more Ys may be bonded to form a monocycle or a condensed ring; and m is an integer of 1 to 4. (In formula (2), X is any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent, and a heteroarylalkyl group having 4 to 20 carbon atoms which may have a substituent, Y and Z are at least one selected from the group consisting of a hydrogen atom, a halogen atom, a hydroxyl group, a carboxy group, a cyano group, a nitro group, an alkyl group of 1 to 20 carbon atoms which may have a substituent, an alkoxy group of 1 to 20 carbon atoms which may have a substituent, an alkenyl group of 2 to 20 carbon atoms which may have a substituent, an aryl group of 6 to 20 carbon atoms which may have a substituent, an aryloxy group of 6 to 20 carbon atoms which may have a substituent, and an acyl group of 1 to 20 carbon atoms which may have a substituent; Y and Z may be the same or different, and two or more Ys or two or more Zs may bond to form a monocyclic or condensed ring; and m and n are each independently an integer of 1 to 4. [2] The epoxy resin composition according to [1], wherein component (A) further comprises a difunctional or lower functional epoxy resin. [3] The epoxy resin composition according to [2], wherein the blending ratio (mass ratio) of the trifunctional or higher polyfunctional epoxy resin to the difunctional or lower functional epoxy resin is in the range of 1:0.1 to 1:10. [4] The resin composition according to any one of [1] to [3], wherein the component (A) comprises an epoxy resin having an aromatic ring. [5] The resin composition according to any one of [1] to [4], wherein the component (A) comprises an epoxy resin having no aromatic ring.[6] In the component (B), in formula (1), Y is one selected from the group consisting of a hydrogen atom, a hydroxyl group, a carboxyl group, an alkoxy group having 1 to 20 carbon atoms and no substituent, an alkyl group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxyl group as a substituent, an alkoxy group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxyl group as a substituent, an aryl group having 6 to 20 carbon atoms and having a hydroxyl group and / or a carboxyl group as a substituent, an aryloxy group having 6 to 20 carbon atoms and having a hydroxyl group and / or a carboxyl group as a substituent, and an acyl group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxyl group as a substituent, The epoxy resin composition according to any one of [1] to [5], wherein in formula (2), Y and Z are one selected from the group consisting of a hydrogen atom, a hydroxyl group, a carboxy group, an unsubstituted alkoxy group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, an alkoxy group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, an aryl group having 6 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, an aryloxy group having 6 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, and an acyl group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent.[7] In the component (B), the compound represented by the formula (1) is any one selected from the group consisting of 2-(2-hydroxyphenyl)imidazole, 2-(2-hydroxyphenyl)-4(5)-methylimidazole, 4-ethyl-(2-hydroxyphenyl)-5-methylimidazole, (2-hydroxyphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-(2-hydroxyphenyl)-5-methylimidazole, and 2-(2-hydroxy-3(5)-methoxyphenyl)imidazole, and / or the compound represented by the formula (2) is any one selected from the group consisting of 2-(2-hydroxyphenyl)imidazole, 2-(2-hydroxyphenyl)-4(5)-methylimidazole, 4-ethyl-(2-hydroxyphenyl)-5-methylimidazole, 4-butyl-(2-hydroxyphenyl)-5-methylimidazole, and 2-(2-hydroxy-3(5)-methoxyphenyl)imidazole. The epoxy resin composition according to any one of [1] to [5], wherein the component (C) is any one selected from the group consisting of 2-(2-hydroxyphenyl)benzimidazole, 2-(2-hydroxy-3(5)-methoxyphenyl)benzimidazole, 2-(1-hydroxynaphthalen-2-yl)benzimidazole, 2-(2-hydroxynaphthalen-1-yl)benzimidazole, and 2-(2-hydroxyphenyl)benzimidazole-6-carboxylic acid. [8] The epoxy resin composition according to any one of [1] to [7], further comprising: component (C): a filler. [9] The epoxy resin composition according to any one of [1] to [8], further comprising: component (E): a thermoplastic resin.

[10] The epoxy resin composition according to any one of [1] to [9], further comprising: component (G): a silane coupling agent.

[11] The epoxy resin composition according to

[10] , wherein the component (G) is an aminosilane coupling agent.

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

[11] , further comprising a component (H): a non-epoxy group-terminated compound having a polyalkylene oxide structure.

[13] The epoxy resin composition according to

[12] , wherein the terminal of the component (H) is a hydroxyl group.

[14] The epoxy resin composition according to

[13] , wherein the component (H) is a compound represented by the following formula (3): (In formula (3), R ３ , R ４ are each independently an alkyl group having 1 to 12 carbon atoms, and R ３ , R ４may be the same or different. p and q are each independently an integer of 1 or more. R ５ , R ６ are each independently one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 6 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent. ５ , R ６ may be the same or different.)

[15] A resin paste comprising the epoxy resin composition according to any one of [1] to

[14] .

[16] A resin film comprising: a support; and a resin layer on the support, the resin layer comprising the epoxy resin composition according to any one of [1] to

[14] .

[17] The resin film according to

[16] , further comprising a protective layer.

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

[14] .

[19] A semiconductor device comprising the cured product according to

[18] as a layer.

[0014] According to the present invention, it is possible to provide an epoxy resin composition which is completely uniform, has sufficient filling property, and, even when a multifunctional epoxy resin is blended therein, has a high glass transition temperature, and is capable of suppressing a decrease in elastic modulus at high temperatures.

[0015] Hereinafter, a mode for carrying out the present invention (hereinafter 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.

[0016] [Epoxy Resin Composition] The epoxy resin composition of the present embodiment comprises: Component (A): an epoxy resin; and Component (B): a compound represented by the following formula (1) and / or a compound represented by the following formula (2), wherein the component (A) comprises at least one polyfunctional epoxy resin having three or more functionalities, and when the temperature is maintained constant at T°C satisfying 130≦T≦150, the slope α of the straight line obtained by plotting Lnt (vertical axis) against 1 / T (horizontal axis) satisfies 690≦α≦1000, where t is the time (minutes) until the viscosity reaches 10,000 Pa s, starting from the temperature T°C.

[0017] (In formula (1), R １ , R ２ are each independently any one selected from the group consisting of a hydrogen atom, a hydroxyl group, a carboxy group, a cyano group, a nitro group, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, and a cycloalkyl group having 6 to 20 carbon atoms which may have a substituent; R １ , R ２ may be the same or different, and R １ , R ２ may be bonded to form a fused ring having no aromaticity, X is any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent, and a heteroarylalkyl group having 4 to 20 carbon atoms which may have a substituent, Y is any one selected from the group consisting of a hydrogen atom, a halogen atom, a hydroxyl group, a carboxy group, a cyano group, a nitro group, an alkyl group of 1 to 20 carbon atoms which may have a substituent, an alkoxy group of 1 to 20 carbon atoms which may have a substituent, an alkenyl group of 2 to 20 carbon atoms which may have a substituent, an aryl group of 6 to 20 carbon atoms which may have a substituent, an aryloxy group of 6 to 20 carbon atoms which may have a substituent, and an acyl group of 1 to 20 carbon atoms which may have a substituent; when there are multiple Ys, they may be the same or different, and two or more Ys may be bonded to form a monocycle or a condensed ring; and m is an integer of 1 to 4.

[0018] In formula (2), X is any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent, and a heteroarylalkyl group having 4 to 20 carbon atoms which may have a substituent; Y and Z are any one selected from the group consisting of a hydrogen atom, a halogen atom, a hydroxyl group, a carboxy group, a cyano group, a nitro group, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, and an acyl group having 1 to 20 carbon atoms which may have a substituent; Y and Z may be the same or different, and two or more Ys and two or more Zs may be bonded to form a monocycle or a condensed ring; m and n each independently represent an integer of 1 to 4.) By adopting such a constitution, the epoxy resin composition of the present embodiment is completely uniform and has sufficient filling properties, and even when a polyfunctional epoxy resin is blended, it not only has a high glass transition temperature but also can suppress a decrease in elastic modulus at high temperatures.

[0019] (Component (A): Epoxy Resin) The epoxy resin composition of the present embodiment contains an epoxy resin (hereinafter, may be referred to as epoxy resin (A) or component (A)). The epoxy resin (A) contains at least one polyfunctional epoxy resin having a functionality of three or more. Among the epoxy resins (A), the tri- or higher functional polyfunctional epoxy resin is not particularly limited as long as it is an epoxy resin having three or more epoxy groups in one molecule. Examples thereof include trifunctional epoxy resins such as trifunctional glycidylamine-type epoxy resins such as triglycidyl-p-aminophenol, triazine-type epoxy resins, trimethylolpropane triglycidyl ether, and glycerin triglycidyl ether; tetrafunctional epoxy resins such as naphthalene-type tetrafunctional epoxy resins, tetraglycidyldiaminodiphenylmethane-type epoxy resins, tetraglycidylbis(aminomethyl)cyclohexane, diaminobenzene-type epoxy resins, and pentaerythritol-type epoxy resins; and polyfunctional epoxy resins such as phenol novolac-type epoxy resins, cresol novolac-type epoxy resins, biphenyl novolac-type epoxy resins, triphenylmethane-type epoxy resins, tetraphenylethane-type epoxy resins, dicyclopentadiene-type epoxy resins, naphthol novolac-type epoxy resins, and brominated phenol novolac-type epoxy resins. These may be used alone or in combination of two or more.

[0020] Among these, from the viewpoints of maintaining fluidity, suppressing a decrease in elastic modulus at high temperatures, and obtaining sufficient strength, the resin paste preferably contains a polyfunctional glycidylamine-type epoxy resin such as triglycidyl-p-aminophenol or tetraglycidyldiaminodiphenylmethane-type epoxy resin, or tetraglycidylbis(aminomethyl)cyclohexane, or a pentaerythritol-type epoxy resin. Furthermore, from the viewpoints of maintaining a high glass transition temperature, suppressing a decrease in elastic modulus at high temperatures, and obtaining sufficient strength, the resin film preferably contains a polyfunctional glycidylamine-type epoxy resin such as triglycidyl-p-aminophenol or tetraglycidyldiaminodiphenylmethane-type epoxy resin, or tetraglycidylbis(aminomethyl)cyclohexane, or a pentaerythritol-type epoxy resin, a naphthalene-type tetrafunctional epoxy resin, a phenol novolac-type epoxy resin, a cresol novolac-type epoxy resin, a biphenyl novolac-type epoxy resin, a triphenylmethane-type epoxy resin, a tetraphenylethane-type epoxy resin, or a pentaerythritol-type epoxy resin.

[0021] Specific examples of the tri- or higher functional polyfunctional epoxy resin include, but are not limited to, HP-4700 and HP-4710 (naphthalene-type tetrafunctional epoxy resins), N-690 and N-695 (cresol novolac-type epoxy resins), HP-7200, HP-7200H and HP-7200HH (dicyclopentadiene-type epoxy resins), HP-6000, HP-6000L, EXA-7311 and EXA-73 manufactured by DIC Corporation. 11-G3, EXA-7311-G4, EXA-7311-G4S (naphthylene ether type epoxy resin), Chang Chun Co., Ltd. product name: CNE220 (cresol novolac type epoxy resin), Nippon Kayaku Co., Ltd. product name: EPPN-502H (triphenylmethane type epoxy resin), NC3000, NC3000H, NC3000L, NC3100 (biphenyl type epoxy resin), NC-7000L (naphthol novolac type epoxy resin), resin), Nippon Steel & Sumikin Chemical Co., Ltd. product names: ESN475V, ESN485 (naphthol-type epoxy resin), Mitsubishi Chemical Corporation product name: YX7700 (xylene structure-containing novolac-type epoxy resin), jER1032S (triphenylmethane-type epoxy resin), jER1031S (tetraphenylethane-type epoxy resin), jER152 (phenol novolac-type epoxy resin), jER630, jER630LSD (glycol Examples of epoxy resins include those manufactured by Mitsubishi Gas Chemical Company, Inc. under the trade names of TETRAD-X and TETRAD-C (glycidylamine-type epoxy resins), those manufactured by Resonac Corporation under the trade name of PETG (pentaerythritol-type epoxy resin), those manufactured by Daicel Corporation under the trade name of Epolead PB-3600 (epoxy resin having a butadiene structure), and those manufactured by Nippon Soda Co., Ltd. under the trade names of JP-100 and JP-200 (epoxy resin having a butadiene structure).

[0022] The epoxy resin (A) other than the tri- or higher functional polyfunctional epoxy resin is not particularly limited as long as it is an epoxy resin having two or less epoxy groups in one molecule, and examples thereof include bisphenol A type, bisphenol F type, bisphenol E type epoxy resin, bisphenol AD ​​type epoxy resin, bisphenol AF type epoxy resin, tetrabromobisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, glycidylamine type epoxy resin, silicone-modified epoxy resin, biphenyl type epoxy resin, bixylenol type epoxy resin, tetrabromobiphenyl type epoxy resin, fluorene type epoxy resin, diphenyl ether bifunctional epoxy resins such as benzophenone-type epoxy resins, phenylbenzoate-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, hydroquinone-type epoxy resins, methylhydroquinone-type epoxy resins, dibutylhydroquinone-type epoxy resins, resorcinol-type epoxy resins, methylresorcinol-type epoxy resins, catechol-type epoxy resins, glycidyl ester-type epoxy resins, and epoxy resins having a butadiene structure.

[0023] Furthermore, although not particularly limited, examples thereof include N,N-diglycidylaminobenzene, o-(N,N-diglycidylamino)toluene, 2-ethylhexyl glycidyl ether, cyclohexanedimethanol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, butanediol diglycidyl ether, glycerin diglycidyl ether, cyclohexane-type diglycidyl ether, dicyclopentadiene-type diglycidyl ether, vinyl(3,4-cyclohexene) dioxide, 2-(3,4-epoxycyclohexyl)-5,1-spiro-(3,4-epoxycyclohexyl)-m-dioxane, 1,3-diglycidyl-5-methyl- Examples of epoxy resins that can also be used as reactive diluents include 5-ethylhydantoin type epoxy resins, 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane type epoxy resins, phenyl glycidyl ether, cresyl glycidyl ether, p-s-butylphenyl glycidyl ether, styrene oxide, p-tert-butylphenyl glycidyl ether, o-phenylphenol glycidyl ether, p-phenylphenol glycidyl ether, N-glycidylphthalimide, n-butyl glycidyl ether, α-pinene oxide, allyl glycidyl ether, 1-vinyl-3,4-epoxycyclohexane, 1,2-epoxy-4-(2-methyloxiranyl)-1-methylcyclohexane, and neodecanoic acid glycidyl ester; and epoxy resins having a polyalkylene oxide structure, such as polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and polytetramethylene glycol diglycidyl ether. These may be used alone or in combination of two or more.

[0024] Among epoxy resins (A) other than the above-mentioned trifunctional or higher polyfunctional epoxy resins, the resin paste preferably contains an epoxy resin having an aromatic ring from the viewpoint of fluidity and strength, and more preferably contains a bisphenol-type epoxy resin such as a bisphenol A-type epoxy resin or a bisphenol F-type epoxy resin, a naphthalene-type epoxy resin, a fluorene-type epoxy resin, p-tert-butylphenyl glycidyl ether, N,N-diglycidylaminobenzene, or o-(N,N-diglycidylamino)toluene. Furthermore, when the filler content is high, when increasing the filling ability, or from the viewpoint of reducing warpage of the cured product, it is preferable to contain an epoxy resin without an aromatic ring or an epoxy resin having a polyalkylene oxide structure, and more preferably contains a hydrogenated bisphenol A-type epoxy resin, a cyclohexane-type diglycidyl ether, a dicyclopentadiene-type diglycidyl ether, or a polytetramethylene glycol diglycidyl ether.

[0025] Furthermore, among the epoxy resins (A) other than the above-mentioned trifunctional or higher polyfunctional epoxy resins, from the viewpoints of heat resistance and strength, the resin film preferably contains an epoxy resin having an aromatic ring, and preferably contains a bifunctional epoxy resin having a bisphenol A structure, a bisphenol F structure, a bisphenol AF structure, a naphthalene structure, a fluorene structure, or a glycidylamine structure. Furthermore, from the viewpoint of imparting appropriate adhesiveness, adhesion, and flexibility to the film, it is preferable to contain a bifunctional epoxy resin having a cyclohexane structure, a cyclohexanedimethanol structure, a polyalkylene oxide structure, or a butadiene structure, or an alicyclic bifunctional epoxy resin having an ester skeleton.

[0026] The epoxy resin (A) other than the tri- or higher functional polyfunctional epoxy resin is not particularly limited, and examples thereof include those manufactured by DIC Corporation under the trade names of EXA850CRP (BisA type epoxy resin), EXA830CRP (BisF type epoxy resin), HP4032, HP4032D, and HP4032SS (naphthalene type epoxy resin); and those manufactured by Mitsubishi Chemical Corporation under the trade names of jER828US, jER828EL, jER825, and YL980 (bisphenol A type epoxy resin), jER807, jER1750, and YL983U (bisphenol F type epoxy resin). YX7400N (polytetramethylene glycol type epoxy resin), YX4000, YX4000H, YX4000HS, YL6121 (biphenyl type epoxy resin), YX4000HK (bixylenol type epoxy resin), YX8800 (anthracene type epoxy resin), YX7760 (fluorine-containing special epoxy resin), Nippon Steel Chemical & Material Co., Ltd. product name: ZX1059 (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin), ZX1658, ZX1658GS (liquid 1,4-glycidylcyclohexane type epoxy resin), Resonac Corporation product name: CDMDG (cyclohexanedimethanol diglycidyl ether), Nippon Kayaku Co., Ltd. product name: GAN (N,N-diglycidyl ether), Examples of such epoxy resins include bisphenol A bis(triethylene glycol glycidyl ether) ether (product name: BEO-60E) manufactured by New Japan Chemical Co., Ltd., EX-721 (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX Corporation, CELLOXIDE 2021P (alicyclic epoxy resin having an ester skeleton) manufactured by Daicel Corporation, OGSOL PG-100, CG-500, EG-280 (fluorene type epoxy resin) manufactured by Osaka Gas Chemicals Co., Ltd., EPOGOSE PT (polytetramethylene glycol type epoxy resin) manufactured by Yokkaichi Synthetic Co., Ltd., and AER9000 (specially modified epoxy resin) manufactured by Asahi Kasei Corporation.

[0027] In the epoxy resin composition of this embodiment, the epoxy resin (A) includes at least one polyfunctional epoxy resin having a functionality of three or more, but is preferably used in combination with a bifunctional or lower epoxy resin. When used in the form of a resin paste, this combination tends to provide the following effects: (i) viscosity can be suitably reduced, improving handling and filling properties; (ii) adhesion to circuit components is improved; and (iii) sufficient flexibility is obtained, improving crack resistance. Furthermore, when used in the form of a resin film, this combination tends to provide the following effects: (iv) adhesiveness and adhesion are improved; (v) sufficient flexibility is obtained, improving handling properties; and (vi) a cured product having sufficient elongation can be obtained. When a tri- or higher functional epoxy resin and a di- or lower functional epoxy resin are used in combination, the mass ratio thereof (tri- or higher functional epoxy resin:di- or lower functional epoxy resin) is not particularly limited, but from the viewpoint of the effects (i) to (vi) above, it is preferably in the range of 1:0.1 to 1:10, more preferably in the range of 1:0.2 to 1:9, even more preferably in the range of 1:0.3 to 1:8, even more preferably in the range of 1:0.4 to 1:7, and even more preferably in the range of 1:0.5 to 1:6.

[0028] The epoxy equivalent of the tri- or higher functional epoxy resin is preferably 50 g / eq. to 500 g / eq., more preferably 50 g / eq. to 450 g / eq., even more preferably 80 g / eq. to 400 g / eq., even more preferably 80 g / eq. to 350 g / eq., and even more preferably 85 to 300 g / eq. When the epoxy equivalent of the tri- or higher functional epoxy resin is within the above-mentioned numerical range, the crosslink density of the cured product of the epoxy resin composition of this embodiment when used in combination with component (B) tends to be in an appropriate range, and a cured product layer with an excellent balance of the glass transition temperature of the cured product, suppression of decrease in elastic modulus at high temperatures, and cured product strength tends to be obtained. The epoxy equivalent of the bi- or lower functional epoxy resin is not particularly limited and can be set appropriately depending on the desired performance, but from the viewpoint of ensuring a sufficient crosslink density when used in combination with a tri- or higher functional epoxy resin and achieving a balance of the elongation, toughness, and strength of the cured product, it is preferably 50 g / eq. to 5000 g / eq. , more preferably 50 g / eq. to 3000 g / eq., even more preferably 80 g / eq. to 2000 g / eq., even more preferably 100 g / eq. to 1000 g / eq., and still more preferably 120 to 900 g / eq. The epoxy equivalent is the mass of a resin containing one equivalent of epoxy groups. The epoxy equivalent can be measured in accordance with JIS K7236.

[0029] From the viewpoint of obtaining an epoxy resin composition having excellent electrical properties and an excellent balance between curability and storage stability, the total chlorine content of the epoxy resin (A) is preferably 2500 ppm or less, more preferably 2000 ppm or less, even more preferably 1500 ppm or less, and even more preferably 900 ppm or less. Also, from the viewpoint of preventing excessive reduction, the total chlorine content of the epoxy resin (A) is preferably 0.01 ppm or more, more preferably 0.02 ppm or more, even more preferably 0.05 ppm or more, still more preferably 0.1 ppm or more, still more preferably 0.2 ppm or more, and particularly preferably 0.5 ppm or more.

[0030] Here, the total chlorine content refers to the total amount of organic chlorine 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 xylene 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 sample, followed by boiling for 20 minutes. The total chlorine content is then calculated from the titer obtained using an aqueous silver nitrate solution.

[0031] The content of the total epoxy resin (A), which is the sum of the tri- or higher functional epoxy resins and the di- or lower functional epoxy resins, in the epoxy resin composition of this embodiment can be appropriately set depending on the desired performance and is not particularly limited, but is preferably 5% by mass or more and 95% by mass or less, more preferably 10% by mass or more and 90% by mass or less, and particularly preferably 15% by mass or more and 85% by mass or less, of all non-volatile components excluding the solvent. By setting the epoxy resin content within the above range, the epoxy resin composition of this embodiment tends to achieve high adhesiveness.

[0032] (Component (B): Compound Represented by Formula (1) or (2) Below) The epoxy resin composition of the present embodiment contains a compound represented by Formula (1) below and / or a compound represented by Formula (2) below (hereinafter, may be referred to as compound (B) or component (B)).

[0033] (In formula (1), R １ , R ２ are each independently any one selected from the group consisting of a hydrogen atom, a hydroxyl group, a carboxy group, a cyano group, a nitro group, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, and a cycloalkyl group having 6 to 20 carbon atoms which may have a substituent; R １ , R ２ may be the same or different, R １ , R ２may be bonded to form a fused ring having no aromaticity, X is any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent, and a heteroarylalkyl group having 4 to 20 carbon atoms which may have a substituent, Y is any one selected from the group consisting of a hydrogen atom, a halogen atom, a hydroxyl group, a carboxy group, a cyano group, a nitro group, an alkyl group of 1 to 20 carbon atoms which may have a substituent, an alkoxy group of 1 to 20 carbon atoms which may have a substituent, an alkenyl group of 2 to 20 carbon atoms which may have a substituent, an aryl group of 6 to 20 carbon atoms which may have a substituent, an aryloxy group of 6 to 20 carbon atoms which may have a substituent, and an acyl group of 1 to 20 carbon atoms which may have a substituent; when there are multiple Ys, they may be the same or different, and two or more Ys may be bonded to form a monocycle or a condensed ring; and m is an integer of 1 to 4.

[0034] In formula (2), X is any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent, and a heteroarylalkyl group having 4 to 20 carbon atoms which may have a substituent; Y and Z are any one selected from the group consisting of a hydrogen atom, a halogen atom, a hydroxyl group, a carboxy group, a cyano group, a nitro group, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, and an acyl group having 1 to 20 carbon atoms which may have a substituent; Y and Z may be the same or different, and two or more Ys and two or more Zs may be bonded to form a monocycle or a condensed ring; m and n are each independently an integer of 1 to 4.

[0035] R in the above general formula (1) １ and R２ As described above, each of R is independently one selected from the group consisting of a hydrogen atom, a hydroxyl group, a carboxy group, a cyano group, a nitro group, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, and a cycloalkyl group having 6 to 20 carbon atoms which may have a substituent, or R １ , R ２ are on the same fused ring without aromaticity, and R １ , R ２ may be the same or different. The alkyl group having 1 to 20 carbon atoms may be linear or branched, and the number of carbon atoms in the alkyl group is preferably 1 to 18, more preferably 1 to 15, and even more preferably 1 to 10. The alkyl group having 1 to 20 carbon atoms is not particularly limited, but examples thereof include a methyl group, an ethyl group, an isopropyl group, a butyl group, an isobutyl group, a hexyl group, an octyl group, and a 2-ethylhexyl group. The number of carbon atoms in the cycloalkyl group having 6 to 20 carbon atoms is preferably 6 to 18, more preferably 6 to 15. The cycloalkyl group having 6 to 20 carbon atoms is not particularly limited, but examples thereof include a cyclohexyl group, a cycloheptane group, and a cyclooctane group. The R １ , R ２ Specific examples of the structure in which R is on the same condensed ring without aromaticity include cyclopentane, cyclohexane, dicyclopentadiene, etc. １ , R ２ The structure on the same fused ring that does not have aromaticity may have a substituent. The substituent is not particularly limited, but examples thereof include a halogen atom, a hydroxyl group, an alkoxy group, and a nitro group, and is preferably a hydroxyl group or an alkoxy group.

[0036] X in the formulas (1) and (2) is any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent, and a heteroarylalkyl group having 4 to 20 carbon atoms which may have a substituent.

[0037] The alkyl group having 1 to 20 carbon atoms represented by X may be linear or branched, and the number of carbon atoms in the alkyl group is preferably 1 to 18, and more preferably 1 to 15. The alkyl group having 1 to 20 carbon atoms is not particularly limited, but examples thereof include a methyl group, an ethyl group, an isopropyl group, a butyl group, an isobutyl group, a hexyl group, and an octyl group.

[0038] The alkenyl group having 2 to 20 carbon atoms represented by X may be linear or branched, and the number of carbon atoms in the alkenyl group is preferably 2 to 18, and more preferably 2 to 15. The alkenyl group having 2 to 20 carbon atoms is not particularly limited, but examples thereof include a vinyl group, an aryl group, a 1-propenyl group, an isopropenyl group, a 2-butenyl group, a 3-butenyl group, a 2-pentenyl group, and a 2-hexenyl group.

[0039] The aralkyl group having 7 to 20 carbon atoms represented by X may be linear or branched, and the number of carbon atoms in the aralkyl group is preferably 7 to 18, more preferably 7 to 15. The aralkyl group having 7 to 20 carbon atoms is not particularly limited, but examples thereof include a benzyl group, a phenethyl group, and a naphthylmethyl group.

[0040] The heteroarylalkyl group having 4 to 20 carbon atoms represented by X may be linear or branched, and the number of carbon atoms in the heteroarylalkyl group is preferably 4 to 18, and more preferably 4 to 15. The heteroarylalkyl group having 4 to 20 carbon atoms is not particularly limited, and examples thereof include a triazinylmethyl group, a triazinylethyl group, a 2-pyridylmethyl group, a 2-pyridylethyl group, a 3-pyridylmethyl group, a 3-pyridylethyl group, a 4-pyridylmethyl group, and a 4-pyridylethyl group.

[0041] Furthermore, the alkyl group, alkenyl group, aralkyl group, or heteroarylalkyl group may have a substituent. The substituent is not particularly limited, but examples thereof include a halogen atom, a cyano group, a nitro group, a hydroxyl group, an alkoxy group, an amino group, an ester group, an arylsulfonyl group, an alkylsulfonyl group, and a phenyl group, and preferred are a cyano group, an alkoxy group, an amino group, an ester group, and a phenyl group.

[0042] Y in the general formula (1) and Y and Z in the general formula (2) are any one selected from the group consisting of a hydrogen atom, a halogen atom, a hydroxyl group, a carboxy group, a cyano group, a nitro group, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, and an acyl group having 1 to 20 carbon atoms which may have a substituent. Furthermore, in the general formula (1), two or more Ys may be bonded to each other to form a monocyclic ring or a condensed ring. Furthermore, in the general formula (2), two or more Ys and two or more Zs may be bonded to each other to form a monocyclic ring or a condensed ring. Furthermore, in the general formula (1), m is an integer of 1 to 4. Furthermore, in the general formula (2), m and n are each independently an integer of 1 to 4.

[0043] The alkyl group having 1 to 20 carbon atoms represented by Y and Z may be linear or branched, and the number of carbon atoms in the alkyl group is preferably 1 to 18, and more preferably 1 to 15. The alkyl group having 1 to 20 carbon atoms is not particularly limited, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a hexyl group, an octyl group, a 2-ethylhexyl group, a decyl group, and an undecyl group.

[0044] The alkoxy group having 1 to 20 carbon atoms represented by Y and Z may be linear or branched, and preferably has 1 to 18 carbon atoms, more preferably 1 to 15 carbon atoms. The alkoxy group having 1 to 20 carbon atoms is not particularly limited, but examples thereof include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a hexyloxy group, and a 2-ethylhexyloxy group.

[0045] The alkenyl group having 2 to 20 carbon atoms represented by Y and Z may be linear or branched, and the number of carbon atoms in the alkenyl group is preferably 2 to 18, and more preferably 2 to 15. The alkenyl group having 2 to 20 carbon atoms is not particularly limited, but examples thereof include a vinyl group, an aryl group, a 1-propenyl group, an isopropenyl group, a 2-butenyl group, a 3-butenyl group, a 2-pentenyl group, and a 2-hexenyl group.

[0046] The number of carbon atoms in the aryl group having 6 to 20 carbon atoms represented by Y and Z is preferably 6 to 18, and more preferably 6 to 15. The aryl group having 6 to 20 carbon atoms is not particularly limited, but examples thereof include a phenyl group, a naphthyl group, an anthracenyl group, and a biphenyl group.

[0047] Furthermore, the structure in which two or more Y's or two or more Z's are bonded to form a single ring or a condensed ring is not particularly limited, but examples thereof include a naphthyl group and an anthracenyl group.

[0048] The number of carbon atoms in the acyl group having 1 to 20 carbon atoms represented by Y and Z is preferably 1 to 18, more preferably 1 to 15. The acyl group having 1 to 20 carbon atoms is not particularly limited, but examples thereof include an acetyl group, a benzoyl group, and a pivaloyl group.

[0049] The alkyl group, alkoxy group, alkenyl group, aryl group, aryloxy group, and acyl group may have a substituent. Examples of the substituent include an alkyl group, a halogen atom, a hydroxyl group, a carboxy group, an alkoxy group, a nitro group, an ester group, and a phenyl group, and preferred are an alkyl group, a hydroxyl group, a carboxy group, and an alkoxy group.

[0050] Y may be substituted at any of the ortho, meta, or para positions of the phenyl group which is the substituent at the 2-position of the imidazole; however, when Y has a substituent, it is preferably substituted at a position other than the ortho position, and more preferably at least the meta position, and more preferably the meta position is substituted with a hydroxyl group or an alkoxy group having 1 to 20 carbon atoms which may have a substituent.

[0051] Among the above, in formula (1), it is preferable that Y is one selected from the group consisting of a hydrogen atom, a hydroxyl group, a carboxy group, an alkoxy group having 1 to 20 carbon atoms and no substituent, an alkyl group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, an alkoxy group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, an aryl group having 6 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, an aryloxy group having 6 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, and an acyl group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent. Furthermore, Y and Z in general formula (2) are more preferably one selected from the group consisting of a hydrogen atom, a hydroxyl group, a carboxy group, an unsubstituted alkoxy group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, an alkoxy group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, an aryl group having 6 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, an aryloxy group having 6 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, and an acyl group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent. When Y and Z are hydrogen atoms, the dielectric loss tangent of the cured product obtained using the epoxy resin composition of this embodiment tends to be even lower. Furthermore, when Y and Z are a hydroxyl group, a carboxyl group, an alkoxy group having 1 to 20 carbon atoms and no substituent, an alkyl group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxyl group as a substituent, an alkoxy group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxyl group as a substituent, an aryl group having 6 to 20 carbon atoms and having a hydroxyl group and / or a carboxyl group as a substituent, an aryloxy group having 6 to 20 carbon atoms and having a hydroxyl group and / or a carboxyl group as a substituent, or an acyl group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxyl group as a substituent, the coordination bond to an adherend such as a metal is increased, and therefore the adhesion and adhesive strength tend to be improved.

[0052] Examples of the compound represented by the general formula (1) include, but are not limited to, the following imidazole compounds: 2-(2-hydroxyphenyl)imidazole, 2-(2-hydroxyphenyl)-4(5)-methylimidazole, 4(5)-ethyl-2-(2-hydroxyphenyl)imidazole, 4,5-dimethyl-2-(2-hydroxyphenyl)imidazole, 4-ethyl-(2-hydroxyphenyl)-5-methylimidazole, (2-hydroxyphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-(2-hydroxyphenyl)-5-methylimidazole, 2-(2-hydroxy-3-methylphenyl)imidazole, 2-(2-hydroxy-3-methylphenyl)-4(5)-methylimidazole, 4(5)-ethyl 2-(2-hydroxy-3-methylphenyl)imidazole, 4,5-dimethyl-2-(2-hydroxy-3-methylphenyl)imidazole, 4-ethyl-(2-hydroxy-3-methylphenyl)-5-methylimidazole, (2-hydroxy-3-methylphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-(2-hydroxy-3-methylphenyl)-5-methylimidazole, 2-(2-hydroxy-4-methylphenyl)imidazole, 2-(2-hydroxy-4-methylphenyl)-4(5)-methylimidazole, 4(5)-ethyl-2-(2-hydroxy-4-methylphenyl)imidazole.

[0053] Further, for example, 4,5-dimethyl-2-(2-hydroxy-4-methylphenyl)imidazole, 4-ethyl-(2-hydroxy-4-methylphenyl)-5-methylimidazole, (2-hydroxy-4-methylphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-(2-hydroxy-4-methylphenyl)-5-methylimidazole, 2-(2-hydroxy-5-methylphenyl)imidazole, 2-(2-hydroxy-5-methylphenyl)-4(5)-methylimidazole, 4(5)-ethyl-2-(2-hydroxy-5-methylphenyl)imidazole, 4, Examples of the hydroxyphenylimidazole include 5-dimethyl-2-(2-hydroxy-5-methylphenyl)imidazole, 4-ethyl-(2-hydroxy-5-methylphenyl)-5-methylimidazole, (2-hydroxy-5-methylphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-(2-hydroxy-5-methylphenyl)-5-methylimidazole, 2-(3-t-butyl-2-hydroxyphenyl)imidazole, 2-(3-t-butyl-2-hydroxyphenyl)-4(5)-methylimidazole, and 2-(3-t-butyl-2-hydroxyphenyl)-4(5)-ethylimidazole.

[0054] Further, for example, 2-(3-t-butyl-2-hydroxyphenyl)-4,5-dimethylimidazole, 2-(3-t-butyl-2-hydroxyphenyl)-4-ethyl-5-methylimidazole, 2-(3-t-butyl-2-hydroxyphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-2-(3-t-butyl-2-hydroxyphenyl)-5-methylimidazole, 2-(4-fluoro-2-hydroxyphenyl)imidazole, 2-(4-fluoro-2-hydroxyphenyl)-4(5)-methylimidazole, 2-(4-fluoro-2-hydroxyphenyl)-4(5)-ethylimidazole, imidazole, 2-(4-fluoro-2-hydroxyphenyl)-4,5-dimethylimidazole, 4-ethyl-2-(4-fluoro-2-hydroxyphenyl)-5-methylimidazole, 2-(4-fluoro-2-hydroxyphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-2-(4-fluoro-2-hydroxyphenyl)-5-methylimidazole, 2-(4-chloro-2-hydroxyphenyl)imidazole, 2-(4-chloro-2-hydroxyphenyl)-4(5)-methylimidazole, 2-(4-chloro-2-hydroxyphenyl)-4(5)-ethylimidazole.

[0055] Furthermore, for example, 2-(4-chloro-2-hydroxyphenyl)-4,5-dimethylimidazole, 2-(4-chloro-2-hydroxyphenyl)-4-ethyl-5-methylimidazole, 2-(4-chloro-2-hydroxyphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-2-(4-chloro-2-hydroxyphenyl)-5-methylimidazole, 2-(4-bromo-2-hydroxyphenyl)imidazole, 2-(4-bromo-2-hydroxyphenyl)-4(5)-methylimidazole, azole, 2-(4-bromo-2-hydroxyphenyl)-4(5)-ethylimidazole, 2-(4-bromo-2-hydroxyphenyl)-4,5-dimethylimidazole, 2-(4-bromo-2-hydroxyphenyl)-4-ethyl-5-methylimidazole, 2-(4-bromo-2-hydroxyphenyl)-4-isopropyl-5-methylimidazole, 2-(4-bromo-2-hydroxyphenyl)-4-butyl-5-methylimidazole, and 2-(2,3-dihydroxyphenyl)imidazole.

[0056] Furthermore, for example, 2-(2,3-dihydroxyphenyl)-4(5)-methylimidazole, 2-(2,3-dihydroxyphenyl)-4(5)-ethylimidazole, 2-(2,3-dihydroxyphenyl)-4,5-dimethylimidazole, 2-(2,3-dihydroxyphenyl)-4(5)-phenylimidazole, 2-(2,3-dihydroxyphenyl)-4,5-diphenylimidazole, 2-(2,5-dihydroxyphenyl)imidazole, 2-(2,5-dihydroxyphenyl)-4(5)-methylimidazole, 2-(2,5-dihydroxyphenyl)-4(5)-ethylimidazole, 2-(2,5-dihydroxyphenyl)-4,5-dimethylimidazole, 2-(2,5-dihydroxyphenyl)-4(5)-phenylimidazole, 2-(2,5-dihydroxyphenyl)-4(5)-phenylimidazole, 2-(2-hydroxy-4-methoxyphenyl)-4,5-diphenylimidazole, 2-(2-hydroxy-4-methoxyphenyl)imidazole, 2-(2-hydroxy-4-methoxyphenyl)-4(5)-methylimidazole, 4(5)-ethyl-2-(2-hydroxy-4-methoxyphenyl)imidazole, 4,5-dimethyl-2-(2-hydroxy-4-methoxyphenyl)imidazole, 2-(2-hydroxy-4-methoxyphenyl)-4(5)-phenylimidazole, 4,5-diphenyl-2-(2-hydroxy-4-methoxyphenyl)imidazole, 2-(2-hydroxy-3-methoxyphenyl)imidazole, 2-(2-hydroxy-3-methoxyphenyl)-4(5)-methylimidazole, 4(5)-ethyl-2-(2-hydroxy-3-methoxyphenyl)imidazole.

[0057] Further, for example, 4,5-dimethyl-2-(2-hydroxy-3-methoxyphenyl)imidazole, 2-(2-hydroxy-3-methoxyphenyl)-4(5)-phenylimidazole, 4,5-diphenyl-2-(2-hydroxy-3-methoxyphenyl)imidazole, 2-(2-hydroxy-5-methoxyphenyl)imidazole, 2-(2-hydroxy-5-methoxyphenyl)-4(5)-methylimidazole, 4(5)-ethyl-2-(2-hydroxy-5-methoxyphenyl)imidazole, 4,5-dimethyl-2-(2-hydroxy-5-methoxyphenyl)imidazole, 2-(2-hydroxy-5-methoxyphenyl)-4(5)-phenylimidazole, 4,5-diphenyl-2-(2-hydroxy-5-methoxyphenyl)imidazole, 2-(2-hydroxy-6-methoxyphenyl)imidazole, 2-( 2-hydroxy-6-methoxyphenyl)-4(5)-methylimidazole, 4(5)-ethyl-2-(2-hydroxy-6-methoxyphenyl)imidazole, 4,5-dimethyl-2-(2-hydroxy-6-methoxyphenyl)imidazole, 2-(2-hydroxy-6-methoxyphenyl)-4(5)-phenylimidazole, 4,5-diphenyl-2-(2-hydroxy-6-methoxyphenyl)imidazole, 2-(3-ethoxy-2-hydroxyphenyl)imidazole, 2-(3-ethoxy-2-hydroxyphenyl)-4(5)-methylimidazole, 2-(3-ethoxy-2-hydroxyphenyl)-4(5)-ethylimidazole, 4,5-dimethyl-2-(3-ethoxy-2-hydroxyphenyl)imidazole, 2-(3-ethoxy-2-hydroxyphenyl)-4(5)-phenylimidazole.

[0058] Further, for example, 4,5-diphenyl-2-(3-ethoxy-2-hydroxyphenyl)imidazole, 2-(5-ethoxy-2-hydroxyphenyl)imidazole, 2-(5-ethoxy-2-hydroxyphenyl)-4(5)-methylimidazole, 2-(5-ethoxy-2-hydroxyphenyl)-4(5)-ethylimidazole, 4,5-dimethyl-2-(5-ethoxy-2-hydroxyphenyl)imidazole, 2-(5-ethoxy-2-hydroxyphenyl)-4(5)-phenylimidazole, 4,5-diphenyl-2-(5-ethoxy-2-hydroxyphenyl)imidazole, 2-(4-allyl-2-hydroxyphenyl)imidazole, 2-(4-allyl-2-hydroxy-3-methoxyphenyl)imidazole, 2-(4-allyl-2-hydroxy-3-methoxyphenyl)-4(5)-methylimidazole, 2-(4-allyl-2-hydroxy-3-methoxyphenyl)-4(5)-ethylimidazole, 2-(4-allyl-2-hydroxy-3-methoxyphenyl)-4,5-dimethylimidazole, 2-(4-allyl-2-hydroxy-3-methoxyphenyl)-4(5)-phenylimidazole, 2-(4-allyl-2-hydroxy-3-methoxyphenyl)-4,5-diphenylimidazole, and 2-(4,6-dimethoxy-2-hydroxyphenyl)imidazole.

[0059] Furthermore, for example, 2-(4,6-dimethoxy-2-hydroxyphenyl)-4(5)-methylimidazole, 2-(4,6-dimethoxy-2-hydroxyphenyl)-4(5)-ethylimidazole, 2-(4,6-dimethoxy-2-hydroxyphenyl)-4,5-dimethylimidazole, 2-(4,6-dimethoxy-2-hydroxyphenyl)-4(5)-phenylimidazole, 2-(4,6-dimethoxy-2-hydroxyphenyl)-4,5-diphenylimidazole, 2-(2-fluoro-5-hydroxyphenyl)imidazole, 2-(2-fluoro-5-hydroxyphenyl)-4(5)- Methylimidazole, 2-(2-fluoro-5-hydroxyphenyl)-4(5)-ethylimidazole, 2-(2-fluoro-5-hydroxyphenyl)-4,5-dimethylimidazole, 2-(2-fluoro-5-hydroxyphenyl)-4(5)-phenylimidazole, 2-(2-fluoro-5-hydroxyphenyl)-4,5-diphenylimidazole, 2-(5-fluoro-2-hydroxyphenyl)imidazole, 2-(5-fluoro-2-hydroxyphenyl)-4(5)-methylimidazole, 2-(5-fluoro-2-hydroxyphenyl)-4(5)-ethylimidazole.

[0060] Furthermore, for example, 2-(5-fluoro-2-hydroxyphenyl)-4,5-dimethylimidazole, 2-(5-fluoro-2-hydroxyphenyl)-4(5)-phenylimidazole, 2-(5-fluoro-2-hydroxyphenyl)-4,5-diphenylimidazole, 2-(5-chloro-2-hydroxyphenyl)imidazole, 2-(5-chloro-2-hydroxyphenyl)-4(5)-methylimidazole, 2-(5-chloro-2-hydroxyphenyl)-4(5)-ethylimidazole, 2-(5-chloro-2-hydroxyphenyl)-4,5-dimethylimidazole, 2-(5-chloro-2-hydroxyphenyl)-4(5)-phenylimidazole azole, 2-(5-chloro-2-hydroxyphenyl)-4,5-diphenylimidazole, 2-(5-bromo-2-hydroxyphenyl)imidazole, 2-(5-bromo-2-hydroxyphenyl)-4(5)-methylimidazole, 2-(5-bromo-2-hydroxyphenyl)-4(5)-ethylimidazole, 2-(5-bromo-2-hydroxyphenyl)-4,5-dimethylimidazole, 2-(5-bromo-2-hydroxyphenyl)-4(5)-phenylimidazole, 2-(5-bromo-2-hydroxyphenyl)-4,5-diphenylimidazole, and 2-(6-fluoro-2-hydroxy-3-methoxyphenyl)imidazole.

[0061] Further, for example, 2-(6-fluoro-2-hydroxy-3-methoxyphenyl)-4(5)-methylimidazole, 2-(6-fluoro-2-hydroxy-3-methoxyphenyl)-4(5)-ethylimidazole, 2-(6-fluoro-2-hydroxy-3-methoxyphenyl)-4,5-dimethylimidazole, 2-(6-fluoro-2-hydroxy-3-methoxyphenyl)-4(5)-phenylimidazole, 2-(6-fluoro-2-hydroxy-3-methoxyphenyl)-4,5-diphenylimidazole, 2-(1-hydroxynaphthalen-2-yl)imidazole, 2-(1-hydroxynaphthalen-2-yl)-4(5)-methylimidazole, 2-(1-hydroxynaphthalen-2-yl)-4(5)-ethylimidazole , 4,5-dimethyl-2-(1-hydroxynaphthalen-2-yl)imidazole, 2-(1-hydroxynaphthalen-2-yl)-4(5)-phenylimidazole, 4,5-diphenyl-2-(1-hydroxynaphthalen-2-yl)imidazole, 2-(2-hydroxynaphthalen-1-yl)imidazole, 2-(2-hydroxynaphthalen-1-yl)imidazole, 2-(2-hydroxynaphthalen-1-yl)-4(5)-methylimidazole, 2-(2-hydroxynaphthalen-1-yl)-4(5)-ethylimidazole, 4,5-dimethyl-2-(2-hydroxynaphthalen-1-yl)imidazole, 2-(2-hydroxynaphthalen-1-yl)-4(5)-phenylimidazole, 4,5-diphenyl-2-(2-hydroxynaphthalen-1-yl)imidazole and the like.

[0062] The compound represented by the general formula (2) is not limited to the following, but examples thereof include the following imidazole compounds. For example, 2-(2-hydroxyphenyl)benzimidazole, 2-(2-hydroxy-3-methylphenyl)benzimidazole, 2-(2-hydroxy-4-methylphenyl)benzimidazole, 2-(2-hydroxy-5-methylphenyl)benzimidazole, 2-(3-t-butyl-2-hydroxyphenyl)benzimidazole, 2-(4-fluoro-2-hydroxyphenyl)benzimidazole, 2-(4-chloro-2-hydroxyphenyl)benzimidazole, 2-(4-bromo-2-hydroxyphenyl)benzimidazole, 2-(2,3-dihydroxyphenyl)benzimidazole, 2-(2,5-dihydroxyphenyl)benzimidazole, 2-(2-hydroxy-4-methoxyphenyl)benzimidazole, 2-(2-hydroxy-3-methoxyphenyl)benzimidazole, 2-(2-hydroxy-5-methoxyphenyl)benzimidazole, 2 -(2-hydroxy-6-methoxyphenyl)benzimidazole, 2-(3-ethoxy-2-hydroxyphenyl)benzimidazole, 2-(5-ethoxy-2-hydroxyphenyl)benzimidazole, 2-(4-allyl-2-hydroxy-3-methoxyphenyl)benzimidazole, 2-(4,6-dimethoxy-2-hydroxyphenyl)benzimidazole, 2-(5-fluoro-2-hydroxyphenyl)benzimidazole, 2-(5-chloro-2-hydroxyphenyl)benzimidazole, 2-(5-bromo-2-hydroxyphenyl)benzimidazole, 2-(6-fluoro-2-hydroxy-3-methoxyphenyl)benzimidazole, 2-(1-hydroxynaphthalen-2-yl)benzimidazole, 2-(2-hydroxynaphthalen-1-yl)benzimidazole, 2-(2-hydroxyphenyl)benzimidazole-6-carboxylic acid and the like.

[0063] Among these, from the viewpoint of obtaining a uniform epoxy resin composition by virtue of excellent solubility in the epoxy resin (A) and solvents, and suppressing a decrease in the elastic modulus in a high temperature range and a high glass transition temperature of the cured product, the compound represented by the general formula (1) is preferably R １ , R ２ are preferably all hydrogen atoms or have different substituents. For example, 2-(2-hydroxyphenyl)imidazole, 2-(2-hydroxyphenyl)-4(5)-methylimidazole, 4-ethyl-(2-hydroxyphenyl)-5-methylimidazole, (2-hydroxyphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-(2-hydroxyphenyl)-5-methylimidazole, and 2-(2-hydroxy-3(5)-methoxyphenyl)imidazole are more preferred, and 2-(2-hydroxyphenyl)imidazole is even more preferred. Furthermore, from the viewpoint of obtaining similar effects, the compound represented by the general formula (2) is preferably 2-(2-hydroxyphenyl)benzimidazole, 2-(2-hydroxy-3(5)-methoxyphenyl)benzimidazole, 2-(1-hydroxynaphthalen-2-yl)benzimidazole, 2-(2-hydroxynaphthalen-1-yl)benzimidazole, or 2-(2-hydroxyphenyl)benzimidazole-6-carboxylic acid, and more preferably 2-(2-hydroxyphenyl)benzimidazole or 2-(2-hydroxy-3(5)-methoxyphenyl)benzimidazole.

[0064] Component (B) has a structural feature in which a hydroxyphenyl group is substituted at the 2-position of the imidazole structure that reacts with epoxy groups. This provides excellent compatibility with resins having aromatic rings and polar solvents, enabling it to dissolve well in various epoxy resins and solvents. Furthermore, as described in Patent Document 4, it is believed that the compatibility of stability and curability is achieved by forming an intramolecular hydrogen bond between the nitrogen, which is the reaction site of the imidazole, and the adjacent hydroxyphenyl group, thereby suppressing the nucleophilicity of the nitrogen on the imidazole during storage, thereby maintaining stability, but dissociating the hydrogen bond upon heating, allowing it to react. Generally, solid-dispersion imidazole compounds with reduced compatibility with epoxy resins are known as highly stable imidazole compounds, but such imidazole compounds have concerns that the solid nature of the compound may result in reduced curing uniformity, and that, particularly when a process is involved in filling narrow gaps as a resin paste, clogging can reduce filling properties, and when a process is involved in thinning the film by blending a solvent, such as in the production of a resin film, residual particles can reduce film-forming properties, making the compound inapplicable to ultra-thin films, and that, depending on the type of solvent, the compound may dissolve even in a solid-dispersion form and not provide stability. Therefore, a compound that can dissolve uniformly in a resin or solvent while maintaining both stability and reactivity, like component (B) used in the epoxy resin composition of this embodiment, is particularly suitable for applications such as resin pastes that are used to fill narrow gaps and resin films that are thinned using a solvent.

[0065] Furthermore, by including component (B) as a catalyst in the epoxy resin composition of this embodiment, surprisingly, when a multifunctional epoxy resin is blended, a significantly high glass transition temperature exceeding the curing temperature can be imparted, thereby suppressing the decrease in elastic modulus at high temperatures. This effect cannot be easily predicted from the structure of component (B). Furthermore, the inventors of the present invention investigated the effects of imidazole compounds with various structures. Among curing agents or curing accelerators that can be dissolved in resins or solvents and completely homogenized, only those containing component (B) were found to be capable of imparting a glass transition temperature exceeding the curing temperature and significantly suppressing the decrease in elastic modulus at high temperatures. They found that combining a multifunctional epoxy resin with component (B) is extremely useful for achieving the above-mentioned effects.

[0066] The present inventors speculate that the mechanism by which the above-mentioned effect is obtained only when component (B) is used in combination is as follows, although it is not intended to be limited to the following. Generally, when the curing temperature is lower than the glass transition temperature of the polymer produced by the reaction, most of the polymer becomes glassy and becomes immobile, significantly reducing the reaction efficiency and making it more likely that unreacted monomers will remain. Therefore, it is extremely difficult to achieve a glass transition temperature higher than the curing temperature. In particular, when a multifunctional epoxy resin is used, the high functional group density tends to cause rapid crosslinking, leading to the formation of locally high molecular weight polymers with high glass transition temperatures, significantly reducing the mobility of the molecular chains and reducing the reaction efficiency. In addition, the increase in viscosity associated with rapid molecular weight increase also reduces the diffusibility of various curing agents and accelerators. This leads to incomplete reaction of the functional groups of the epoxy resin or curing agent, or to uneven curing due to localized viscosity increase, making it difficult to achieve sufficient crosslink density. As a result, even when a multifunctional epoxy resin was used in the past, problems such as a lower-than-expected glass transition temperature and a significant decrease in elastic modulus at high temperatures occurred. Furthermore, when a curing agent or curing accelerator with low stability is used, the viscosity increase becomes more rapid, making the above problem more pronounced. While the use of a highly stable solid-dispersion curing agent or curing accelerator can suppress viscosity increase, when the diffusibility of various components decreases as the reaction progresses, the curing agent or curing accelerator components tend to not completely diffuse and remain solid in the composition, resulting in uneven curing. On the other hand, when component (B) is used, due to its structural characteristics, it is thought that the adjacent hydroxyphenyl group acts as a chain transfer agent, donating a proton to the anion generated when the epoxy group reacts with imidazole to open the ring, thereby stabilizing it. Therefore, during the polymerization reaction, the rapid production of high molecular weight compounds and viscosity increase can be suppressed, and a chain extension reaction can occur throughout the system. Therefore, even when a multifunctional epoxy resin is used, viscosity increase during curing can occur slowly and uniformly, and unreacted epoxy groups are less likely to remain, resulting in a high crosslink density and a cured layer with a high glass transition temperature and elastic modulus that is less likely to decrease even at high temperatures.Furthermore, it is believed that the hydroxyphenyl group in component (B) undergoes an addition reaction with the epoxy group to form a bond. Generally, if a compound that is not involved in the bond remains in the polymer, it weakens the intermolecular forces between polymer chains, causing a decrease in the glass transition temperature. However, in the case of component (B), the compound is incorporated into the crosslinked structure by bonding, so the glass transition temperature is not decreased. Furthermore, since component (B) has an aromatic ring, it exhibits a stacking effect with the epoxy resin, which also has an abundance of aromatic rings, and further strengthens the intermolecular forces between polymer chains, thereby further improving the glass transition temperature and further suppressing the decrease in elastic modulus at high temperatures.

[0067] Based on the above mechanism, it is believed that the effects of the present invention can be achieved by using a wide range of component (B) having the structural characteristics represented by general formula (1) and / or (2), including those having various functional group substitutions, in combination with a tri- or higher functional epoxy resin.

[0068] In the epoxy resin composition of this embodiment, the mass ratio of the tri- or higher functional epoxy resin to component (B) is not particularly limited and can be appropriately set based on the curing conditions, desired reaction rate, and performance. For example, the mass ratio of the non-volatile components excluding the solvent, where the tri- or higher functional epoxy resin is taken as 100, is preferably 100:0.001 to 100:20, more preferably 100:0.005 to 100:15, even more preferably 100:0.005 to 100:10, even more preferably 100:0.01 to 100:5, even more preferably 100:0.015 to 100:4, and particularly preferably 100:0.02 to 100:3. By setting the mass ratio within this range, the curing ability of the tri- or higher functional epoxy resin due to component (B) can be obtained in just the right amount, and the good curability tends to result in uniform curing and good storage stability.

[0069] The content of component (B) in the entire epoxy resin composition of this embodiment is not particularly limited, but from the viewpoint of obtaining sufficient curability, it is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.02% by mass or more, even more preferably 0.04% by mass or more, and even more preferably 0.05% by mass or more, based on all non-volatile components excluding the solvent. From the viewpoint of maintaining an appropriate curing rate and maintaining uniformity of the cured layer, it is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, even more preferably 15% by mass or less, and even more preferably 10% by mass or less. However, because component (B) catalytically reacts with component (A): the epoxy resin, a person skilled in the art can determine an appropriate amount taking into consideration the materials and composition used and the desired performance.

[0070] (Reaction Sensitivity Parameter α of Epoxy Resin Composition) When the epoxy resin composition of this embodiment is maintained at a constant temperature T°C that satisfies 130≦T≦150, and the time t minutes required for the viscosity to reach 10,000 Pa s is defined as the time from the temperature T°C to the reference temperature, the slope α of the line obtained by plotting Lnt (vertical axis) against 1 / T (horizontal axis) (hereinafter sometimes referred to as parameter α) satisfies 690≦α≦1,000. In this embodiment, parameter α is calculated as follows: At least two or more temperatures T°C that satisfy 130≦T≦150 are selected, and the time-dependent viscosity of the epoxy resin composition is measured using a rheometer under the selected constant temperature and oscillation (f=1 Hz) conditions. The time t minutes required for the viscosity to reach 10,000 Pa s is measured from the temperature T°C to the reference temperature. Next, the values ​​of Lnt obtained as above are plotted against 1 / T, with 1 / T on the horizontal axis and Ln (natural logarithm) t on the vertical axis. Then, an approximation line is created for the plotted data points by the least squares method, and α can be determined as the slope of the line. A HAAKE MARS manufactured by Thermo Scientific Corp. or the like can be used as a rheometer. The value of the parameter α varies depending on the type and amount of epoxy resin and curing agent. When the parameter α satisfies 690≦α≦1000, the epoxy resin composition has good filling properties and, after curing, can achieve both a high glass transition temperature and a decrease in elastic modulus at high temperatures.

[0071] The present inventors have hypothesized, but not limited to, the mechanism by which the above-mentioned effects are obtained when the parameter α is within the above range. The parameter α is a parameter that depends on the time it takes for the epoxy resin composition to reach a gel state with a high viscosity of 10,000 Pa·s at a predetermined temperature, and is thought to indicate the reactivity sensitivity of the epoxy resin composition when heated. For example, a smaller value of the parameter α indicates a lower reactivity sensitivity to heating temperature, i.e., an epoxy resin composition with a small temperature-dependent change in reactivity. If the parameter α is 690 or greater, the epoxy resin composition can maintain its filling properties while suppressing viscosity increase in a temperature range of, for example, 130°C or less, and can sufficiently cure due to its sufficient reactivity at elevated temperatures, thereby achieving the desired glass transition temperature and suppressing the decrease in elastic modulus. On the other hand, a larger value of the parameter α indicates an epoxy resin composition with an extremely large temperature-dependent change in reactivity. If the parameter α is 1,000 or less, the epoxy resin composition can be heated without undergoing an excessively fast reaction, ensuring filling properties and maintaining a uniform cured structure. Furthermore, the curing reaction proceeds sufficiently without requiring excessive heat to cause a reactivity change, and the desired glass transition temperature and the effect of suppressing the decrease in elastic modulus can be obtained. From the above, it is believed that there is an optimum range for the parameter α in terms of the filling ability of the epoxy resin composition and the physical properties of the cured product, and that this range is 690≦α≦1000.

[0072] The parameter α is controlled by the combination of the types and amounts of epoxy resin, curing agent, or curing accelerator used in the epoxy resin composition. For example, epoxy resins having aromatic rings tend to decrease α, while aliphatic epoxy resins tend to increase α. Furthermore, a smaller epoxy equivalent tends to decrease α, while a larger epoxy equivalent tends to increase α. The curing agent or curing accelerator is appropriately adjusted by selecting component (D) and other curing agents described below. For example, a curing agent with higher reactivity tends to decrease α, while a curing agent with lower reactivity tends to increase α. Therefore, by appropriately selecting the materials used to adjust the parameter α of the epoxy resin composition and setting it within the range of 690≦α≦1000, the desired filling properties and cured product properties can be achieved. From the viewpoint of achieving the above-mentioned effects, the parameter α is 690 or more, more preferably 695 or more, and even more preferably 700 or more. From the same viewpoint, the parameter α is 1000 or less, more preferably 990 or less, even more preferably 980 or less, even more preferably 970 or less, still more preferably 960 or less, and particularly preferably 950 or less.

[0073] (Component (C): Filler) The epoxy resin composition of this embodiment may further contain a filler (hereinafter, may be referred to as filler (C) or component (C)). The filler (C) is not particularly limited, but from the viewpoint of reducing warpage, examples include inorganic fillers (inorganic bulking agents), inorganic fillers pre-treated with a silane coupling agent (G) described below, and from the viewpoint of improving adhesive strength and crack resistance, examples include one or more organic fillers. These may be used alone or in combination of two or more. The shape of the filler (C) is not particularly limited, and may be, for example, amorphous, spherical, or scaly. From the viewpoint of approximating the linear expansion coefficients of the epoxy resin composition of this embodiment and the substrate to be adhered, thereby reducing warpage, it is preferable to contain an inorganic filler.

[0074] Examples of inorganic fillers include, but are not limited to, silica, alumina, glass, cordierite, silicone oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate; carbons such as carbon nanotubes and graphene; metals or alloys such as gold, silver, copper, nickel, aluminum, zinc, tin, lead, solder, indium, and palladium; and particles of a polymer core coated with a metal thin film. Among these, silica is preferred from the viewpoint of further reducing warpage of the cured product. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, hollow silica, etc., and from the viewpoint of improving filling properties and ease of handling of the epoxy resin composition, it is more preferable that the shape is spherical. Commercially available spherical fused silica is not particularly limited, but examples include those manufactured by Admatechs Co., Ltd. under the trade names SO-C2, SO-C1, SO-E2, and SO-E1.

[0075] Furthermore, when thermal conductivity is to be imparted to the epoxy resin composition of the present embodiment, the inorganic filler preferably contains, for example, thermally conductive ceramic particles or metal particles. Specifically, it is preferable to contain, for example, alumina particles, aluminum nitride particles, boron nitride particles, zinc oxide particles, silicon nitride particles, silicon carbide particles, magnesium oxide particles, gold particles, silver particles, nickel particles, and particles coated with these metal thin films. From the viewpoints of dispersibility, high thermal conductivity, and resistance to oxidative degradation, for example, alumina particles, aluminum nitride particles, boron nitride particles, gold particles, and silver particles are more preferable.

[0076] The average particle size of the filler (C) is not particularly limited, but from the viewpoints of the ability to fill fine gaps and the adhesiveness and adhesion when an epoxy resin composition containing the component (C) is used, it is preferably 20 μm or less, more preferably 10 μm or less, even more preferably 5 μm or less, more preferably 3 μm or less, even more preferably 2 μm or less, even more preferably 1 μm or less, and particularly preferably 0.5 μm or less. On the other hand, from the viewpoints of achieving a suitable viscosity and easy handling when forming a resin paste using the epoxy resin composition, the average particle size of the component (C): filler is preferably 0.01 μm or more, more preferably 0.03 μm or more, even more preferably 0.05 μm or more, even more preferably 0.07 μm or more, and particularly preferably 0.1 μm or more. In this embodiment, the average particle size of the filler can be measured by a laser diffraction / scattering method based on the Mie scattering theory. Specifically, the particle size distribution of the filler is calculated on a volume basis using a laser diffraction particle size distribution analyzer, and the median diameter is used as the average particle size. Examples of the laser diffraction particle size distribution analyzer that can be used include a HELOS (trade name) manufactured by Sympatec.

[0077] The content of the filler (C) can be appropriately set depending on the contents of components (A) and (B). When an inorganic filler is used as the filler (C), the content of the inorganic filler in the epoxy resin composition of the present embodiment can be appropriately set depending on the desired performance and is not particularly limited. It is preferably 5 to 98 mass %, more preferably 10 to 95 mass %, even more preferably 15 to 90 mass %, even more preferably 20 to 88 mass %, still more preferably 25 to 85 mass %, and particularly preferably 30 to 80 mass % of all non-volatile components excluding the solvent. By setting the content within this range, the epoxy resin composition of the present embodiment can further exhibit the effects (i) to (iii), such as (i) maintaining an appropriate viscosity and excellent handleability, (ii) achieving an adequate ratio of the resin components and the inorganic filler, resulting in excellent adhesiveness, adhesion, and dimensional stability, and (iii) suppressing warpage and reducing the decrease in elastic modulus at high temperatures when the resin composition is cured, and excellent breaking strength.

[0078] The organic filler functions as an impact absorbing agent having stress relaxation properties. By including the organic filler, the epoxy resin composition of the present embodiment can further improve adhesion to various connecting members and also tends to be able to suppress the occurrence and propagation of fillet cracks.

[0079] Examples of the organic filler include, but are not limited to, organic fine particles of acrylic resin, silicone resin, butadiene rubber, polyester, polyurethane, polyvinyl butyral, polyarylate, polymethyl methacrylate, acrylic rubber, polystyrene, acrylonitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), silicone-modified resin, and copolymers containing these as components. From the viewpoint of improving adhesiveness, preferred examples of the organic fine particles include alkyl (meth)acrylate-butadiene-styrene copolymer, alkyl (meth)acrylate-silicone copolymer, silicone-(meth)acrylic copolymer, a composite of silicone and (meth)acrylic acid, a composite of alkyl (meth)acrylate-butadiene-styrene and silicone, and a composite of alkyl (meth)acrylate and silicone.

[0080] The organic filler may also be organic fine particles having a core-shell structure, with the core and shell layers having different compositions. Examples of core-shell organic fine particles include, but are not limited to, particles having a silicone-acrylic rubber core and an acrylic resin grafted thereto, and particles having an acrylic resin grafted to an acrylic copolymer. The low elastic modulus achieved by the inclusion of core-shell organic fine particles tends to reduce stress generated in the fillet portion and inhibit the occurrence of fillet cracks. Furthermore, if fillet cracks do occur, the contained core-shell organic fine particles act as a stress reliever, tending to inhibit the progression of the fillet cracks. A material with excellent flexibility is preferably used as the constituent material for the core layer. Examples of constituent materials for the core layer include, but are not limited to, silicone-based elastomers, butadiene-based elastomers, styrene-based elastomers, acrylic elastomers, polyolefin-based elastomers, and silicone / acrylic composite elastomers. On the other hand, the constituent material for the shell layer is preferably a material with excellent affinity for other components of the semiconductor resin encapsulant, particularly for epoxy resins. Examples of materials for the shell layer include, but are not limited to, acrylic resins and epoxy resins. Among these, acrylic resins are particularly preferred from the viewpoint of affinity with other components of the encapsulant, particularly affinity with epoxy resins.

[0081] When an organic filler is used as the filler (C), the content of the organic filler in the epoxy resin composition of the present embodiment can be appropriately set depending on the desired performance and is not particularly limited, but is preferably 1 to 20 mass %, more preferably 2 to 18 mass %, and even more preferably 3 to 16 mass %, relative to the total amount of the epoxy resin composition. When the content of the organic filler is 1 mass % or more, stress relaxation works and the effect of improving adhesive strength tends to be obtained. When the content of the organic filler is 20 mass % or less, the effect of heat reflow resistance tends to be obtained.

[0082] (Component (D): Other Curing Agents) The epoxy resin composition of this embodiment may further include the above-described component (B): a curing agent other than the compounds of general formulas (1) and (2) (hereinafter, this may be referred to as curing agent (D) or component (D)). Component (D) may be any conventionally known curing agent used in epoxy resins, and is not particularly limited. Examples of component (D) include amine-based curing agents, amide-based curing agents, phenol-based curing agents, acid anhydride-based curing agents, imidazole-based curing agents (excluding component (B)), active ester-based curing agents, cyanate ester-based curing agents, carbodiimide-based curing agents, benzoxazine-based curing agents, phosphorus-based curing agents, thiol-based curing agents, catalyst-based curing agents, and modified products thereof. These may be used alone or in combination of two or more.

[0083] Examples of amine curing agents include, but are not limited to, aliphatic amines, aromatic amines, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, etc. Examples of aliphatic amines include, but are not limited to, triethylamine, tributylamine, diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, m-xylenediamine, trimethylhexamethylenediamine, 2-methylpentamethylenediamine, isophoronediamine, 1,3-bisaminomethylcyclohexane, 1,4-bisaminomethylcyclohexane, bis(4-aminocyclohexyl)methane, norbornenediamine, 1,2-diaminocyclohexane, etc. Examples of aromatic amines include, but are not limited to, diaminodiphenylmethane, m-phenylenediamine, diaminodiphenylsulfone, diethyltoluenediamine, 1-methyl-3,5-diethyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,6-diaminobenzene, 1,3,5-triethyl-2,6-diaminobenzene, 3,3'-diethyl-4,4'-diaminodiphenylmethane, 3,5,3',5'-tetramethyl-4,4'-diaminodiphenylmethane, trimethylenebis(4-aminobenzoate), polytetramethyleneoxide-di-p-aminobenzoate, aminobenzylamine, jER Cure WA (trade name, manufactured by Mitsubishi Chemical Corporation), and KAYAHARD (trade name, manufactured by Nippon Kayaku Co., Ltd.). Examples include A-A and Mitsui Fine Chemicals Co., Ltd.'s trade names: Ethacure 100, Ethacure 100 Plus, Ethacure 300, and Ethacure 420. Among these, from the viewpoint of improving the glass transition temperature, it is preferable to contain an aromatic amine, and from the viewpoint of excellent liquid handling properties, filling properties, and adhesion, it is more preferable to contain diethyltoluenediamine, 1-methyl-3,5-diethyl-2,4-diaminobenzene, 1-methyl-3,5-diethyl-2,6-diaminobenzene, 1,3,5-triethyl-2,6-diaminobenzene, 3,3'-diethyl-4,4'-diaminodiphenylmethane, and 3,5,3',5'-tetramethyl-4,4'-diaminodiphenylmethane.

[0084] Examples of amide-based curing agents include, but are not limited to, dicyandiamide and its derivatives, such as guanidine compounds, or amine-based curing agents to which acid anhydrides are added, and hydrazide-based compounds. From the viewpoints of high adhesion and availability, it is preferable to use dicyandiamide or a hydrazide-based compound.

[0085] Examples of hydrazide curing agents made of hydrazide compounds include, but are not limited to, succinic acid dihydrazide, adipic acid dihydrazide, phthalic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, p-oxybenzoic acid hydrazide, salicylic acid hydrazide, phenylaminopropionic acid hydrazide, and maleic acid dihydrazide.

[0086] Examples of guanidine-based curing agents made of guanidine compounds include, but are not limited to, dicyandiamide derivatives such as dicyandiamide, dicyandiamide-aniline adduct, dicyandiamide-methylaniline adduct, dicyandiamide-diaminodiphenylmethane adduct, and dicyandiamide-diaminodiphenyl ether adduct; guanidine salts such as guanidine nitrate, guanidine carbonate, guanidine phosphate, guanidine sulfamate, and aminoguanidine bicarbonate; methylguanidine, ethylguanidine, propylguanidine, butylguanidine, dimethylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, cyclohexylguanidine, phenylguanidine, diphenylguanidine, toluylguanidine; methylbiguanide, diacetylguanidine, propionylguanidine, dipropionylguanidine, cyanoacetylguanidine, guanidine succinate, diethylcyanoacetylguanidine, dicyandiamidine, N-oxymethyl-N'-cyanoguanidine, N,N'-dicarbethoxyguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, 1-(o-tolyl)biguanide, and the like.

[0087] Examples of phenolic curing agents include, but are not limited to, phenol novolac resins, bisphenol A novolac resins, cresol novolac resins, phenol aralkyl resins, cresol aralkyl resins, naphthol-phenol co-condensed novolac resins, naphthol-cresol co-condensed novolac resins, allyl acrylic phenolic resins, dicyclopentadiene skeleton-containing phenolic resins, biphenyl skeleton-containing phenolic resins, naphthalene skeleton-containing phenolic resins, and triazine skeleton-containing phenolic resins. Note that triazine skeleton-containing phenolic resins function as curing agents for epoxy resins and have both a triazine skeleton and a structure derived from a phenolic compound in one molecule, and are generally produced by condensing a phenolic compound with a compound having a triazine ring, such as melamine or benzoguanamine, and formaldehyde. Among these, from the viewpoints of achieving a high glass transition temperature of the cured product, suppressing a decrease in elastic modulus in the high temperature range, and improving strength, it is preferable to use a phenolic curing agent having a bisphenol A structure, a bisphenol F structure, a bisphenol AF structure, a naphthalene structure, a phenol novolac structure, a cyclohexane structure, a cyclohexanedimethanol structure, a butadiene structure, a biphenyl structure, a bixylenol structure, a cresol novolac structure, a dicyclopentadiene structure, a trisphenol structure, a naphthol structure, a naphthylene ether structure, an anthracene structure, a tetraphenylethane structure, a bisphenolacetophenone structure, a fluorene structure, or a triazine structure.

[0088] Commercially available phenolic curing agents are not particularly limited, but examples thereof include: trade names TD2090 (phenol novolac resin), EXB-9500 (naphthalene skeleton-containing phenolic resin), LA3018, LA3018-50P, LA7052, LA7054, and LA1356 (triazine skeleton-containing phenolic resins), manufactured by DIC Corporation; and trade name HF-1M (phenol novolac resin), manufactured by UBE. , MEH-7700, MEH-7810, MEH-7851 (biphenyl skeleton-containing phenolic resins), Nippon Kayaku Co., Ltd. trade names: NHN, CBN, GPH (naphthalene skeleton-containing phenolic resins), Nippon Steel Chemical & Material Co., Ltd. trade names: SN170, SN180, SN190, SN475, SN485, SN495, SN375, SN395 (naphthalene skeleton-containing phenolic resins), and the like.

[0089] Examples of acid anhydride curing agents include, but are not limited to, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride.

[0090] The imidazole-based curing agent excluding the component (C) is not limited to the following, but examples thereof include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, and 1-cyanoethyl-2-phenylimidazolium trimellitate. 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine socyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline, and the like.

[0091] An active ester curing agent functions as a curing agent for epoxy resins and has an active ester in its molecule. When the epoxy resin composition of this embodiment contains an active ester curing agent as component (D), the reaction between the active ester and the epoxy group does not produce hydroxyl groups, which are a factor in increasing the dielectric loss tangent, in the epoxy resin composition, and therefore tends to lower the dielectric loss tangent. The active ester curing agent is not particularly limited, but from the viewpoint of ensuring crosslink density, a compound having two or more active ester groups in one molecule is preferred. Furthermore, from the viewpoints of achieving a high glass transition temperature of the epoxy resin composition of this embodiment and suppressing a decrease in elastic modulus at high temperatures, active ester compounds obtained by reacting a carboxylic acid compound and / or a thiocarboxylic acid compound with a hydroxy compound and / or a thiol compound are more preferred, and active ester compounds obtained by reacting a carboxylic acid compound with one or more compounds selected from a phenol compound, a naphthol compound, and a thiol compound are even more preferred. Furthermore, aromatic compounds having two or more active ester groups in one molecule obtained by reacting a carboxylic acid compound with an aromatic compound having a phenolic hydroxyl group are even more preferred. Furthermore, an aromatic compound obtained by reacting a compound having at least two or more carboxylic acids in one molecule with an aromatic compound having a phenolic hydroxyl group, and having two or more active ester groups in one molecule of the aromatic compound, is even more preferred. Furthermore, the active ester curing agent may be linear or multi-branched. Furthermore, if the compound having at least two or more carboxylic acids in one molecule contains an aliphatic chain, it can enhance compatibility with epoxy resins, and if it contains an aromatic ring, it tends to further enhance the effect of high glass transition temperature and suppressing the decrease in elastic modulus at high temperatures.

[0092] Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. In particular, from the viewpoint of achieving a high glass transition temperature of the epoxy resin composition of this embodiment and suppressing a decrease in elastic modulus in the high temperature range, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, and terephthalic acid are preferred, and isophthalic acid and terephthalic acid are more preferred. Examples of the thiocarboxylic acid compound include, but are not limited to, thioacetic acid and thiobenzoic acid. Examples of the phenol compound or naphthol compound include, but are not particularly limited to, hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalene, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadienyldiphenol, and phenol novolak.Among these, from the viewpoints of high glass transition temperature, suppression of decrease in elastic modulus in a high temperature region, and solubility in epoxy resins and solvents, bisphenol A, bisphenol F, bisphenol S, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadienyldiphenol, and phenol novolak are preferred, and catechol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadienyldiphenol, and phenol novolak are preferred. Hydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadienyl diphenol, and phenol novolac are more preferred, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, dicyclopentadienyl diphenol, and phenol novolac are even more preferred, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, dicyclopentadienyl diphenol, and phenol novolac are even more preferred, and dicyclopentadienyl diphenol and phenol novolac are particularly preferred. Examples of the thiol compound include, but are not limited to, benzenedithiol and triazinedithiol.

[0093] The active ester compound serving as the active ester curing agent is not particularly limited, and examples thereof include the active ester compounds disclosed in JP-A-2004-277460 and JP-A-2013-40270, and commercially available active ester compounds. Examples of commercially available active ester compounds include, but are not limited to, those manufactured by DIC Corporation under the trade names EXB9451, EXB9460, EXB9460S, and HPC-8000-65T (active ester compounds containing a dicyclopentadiene-type diphenol structure), EXB9416-70BK (active ester compound containing a naphthalene structure), and EXB9050L-62M (phosphorus atom-containing active ester compound), and those manufactured by Mitsubishi Chemical Corporation under the trade names DC808 (active ester compound containing an acetylated product of phenol novolac), and YLH1026 (active ester compound containing a benzoylated product of phenol novolac).

[0094] A cyanate ester curing agent functions as a curing agent for epoxy resins and has a cyanato group in its molecule. The inclusion of a cyanate ester curing agent as component (D) in the epoxy resin composition of this embodiment produces an oxazoline ring or an oxazolidinone ring upon reaction with the epoxy group, imparting flexibility to the epoxy resin composition. Furthermore, trimerization of the cyanato group results in the formation of a triazine skeleton, which tends to reduce warpage and achieve a particularly high glass transition temperature. Furthermore, since hydroxyl groups are less likely to be generated during the reaction, the dielectric loss tangent tends to be kept low.

[0095] Examples of cyanate ester curing agents include, but are not limited to, novolac-type (phenol novolac type, alkylphenol novolac type, etc.) cyanate ester resins, dicyclopentadiene-type cyanate ester resins, bisphenol-type (bisphenol A type, bisphenol F type, bisphenol S type, etc.) cyanate ester resins, and prepolymers of these that are partially converted to triazine. Specific examples of cyanate ester resins include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate (oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatephenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanatephenyl-1-(methylethylidene))benzene, bis(4-cyanatephenyl)thioether, and bis(4-cyanatephenyl)ether; polyfunctional cyanate resins derived from phenol novolac, cresol novolac, and dicyclopentadiene structure-containing phenolic resins; and prepolymers in which these cyanate resins are partially converted to triazine. These may be used alone or in combination of two or more. Commercially available cyanate ester resins are not particularly limited, but examples thereof include CYTESTER (registered trademark) TA (bisphenol A-type cyanate ester resin) manufactured by Mitsubishi Gas Chemical Company, Inc.

[0096] Examples of carbodiimide curing agents include, but are not limited to, trade names Carbodilite V-02B, V-03, V-04K, V-07, and V-09 manufactured by Nisshinbo Chemical Inc., and trade names Stabaxol P, P400, and Hi-Kasil 510 manufactured by Rhein Chemie. Modified carbodiimide compounds such as those disclosed in Japanese Patent No. 7226954 may also be used.

[0097] Examples of benzoxazine curing agents include, but are not limited to, HFB2006M (trade name) manufactured by Showa Highpolymer Co., Ltd., and Pd, Fa, and ALP-d (trade names) manufactured by Shikoku Kasei Holdings Co., Ltd.

[0098] Examples of phosphorus-based curing agents include, but are not limited to, triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate.

[0099] The thiol curing agent may be any agent containing two or more thiol groups in one molecule, and is not limited to the following. Examples include 3,3'-dithiodipropionic acid, trimethylolpropane tris(thioglycolate), pentaerythritol tetrakis(thioglycolate), ethylene glycol dithioglycolate, 1,4-bis(3-mercaptobutyryloxy)butane, tris[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, 1,3,5-tris(3-mercaptobutyloxyethyl)-1, Examples of the alkyl acrylate include 3,5-triazine-2,4,6(1H,3H,5H)-trione, trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptobutyrate), dipentaerythritol hexakis(3-mercaptopropionate), 1,3,4,6-tetrakis(2-mercaptoethyl)glycoluril, 4-butanedithiol, 1,6-hexaneedithiol, and 1,10-decanedithiol. From the viewpoint of the impact resistance of a cured product of the epoxy resin composition of the present embodiment, 1,4-bis(3-mercaptobutyryloxy)butane, 1,3,5-tris(3-mercaptobutyloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, pentaerythritol tetrakis(3-mercaptopropionate), and pentaerythritol tetrakis(3-mercaptobutyrate) are preferred, and from the viewpoint of the low-temperature curing ability of the epoxy resin composition of the present embodiment, pentaerythritol tetrakis(3-mercaptopropionate) and pentaerythritol tetrakis(3-mercaptobutyrate) are more preferred.

[0100] The catalyst type curing agent is not limited to the following, but for example, a cationic thermosetting catalyst, BF ３ -amine complexes and the like.

[0101] Modified curing agents include, but are not limited to, polyamine compounds, amine-epoxy adducts, amine-urea adducts, imidazole-epoxy adducts, amine imide compounds, or microcapsule-type curing agents coated with these, curing agents adsorbed on porous bodies, etc. Specific examples include, but are not limited to, products manufactured by Asahi Kasei Corporation under the trade names Novacure HX-3722, HX-3742, HX-3088, HX-3613, HXA3932HP, HXA9322HP, HXA9382HP, and HXA9192HP; products manufactured by Ajinomoto Fine-Techno Co., Inc. under the trade names Amicure PN-23J, PN-40J, and MY-24; and products manufactured by Fuji Chemical Industry Co., Ltd. under the trade names Fujicure FXR-1020 and FXR-1030.

[0102] The content of component (D) in the epoxy resin composition of this embodiment can be appropriately set depending on the reactivity with the above-mentioned components (A) and (B) and the desired performance, and is not particularly limited, but from the viewpoint of obtaining good reactivity, it is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, and even more preferably 1.0% by mass or more of all non-volatile components excluding the solvent. Furthermore, from the viewpoint of obtaining good storage stability, it is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less.

[0103] (Component (E): Thermoplastic Resin) The epoxy resin composition of the present embodiment may further contain a thermoplastic resin (hereinafter, may be referred to as thermoplastic resin (E) or component (E)). By containing the thermoplastic resin (E), when the epoxy resin composition of the present embodiment is formed into a film by casting or applying it to a certain thickness and drying it, it is possible to prevent cracks and breaks and maintain the film shape.

[0104] Examples of the thermoplastic resin (E) include, but are not limited to, phenoxy resin, polyvinyl acetal resin, acid anhydride group-containing vinyl resin, polyolefin resin, polybutadiene resin, polyimide resin, polyamide-imide resin, styrene-based elastomer resin, polyether sulfone resin, polyphenylene ether resin, polysulfone resin, acrylic resin, etc. The thermoplastic resin (E) may be used singly or in combination of two or more.

[0105] From the viewpoint of obtaining a cured layer having sufficient strength, the weight average molecular weight of the thermoplastic resin (E) is preferably 10,000 or more, more preferably 15,000 or more, even more preferably 20,000 or more, still more preferably 25,000 or more or 30,000 or more. From the viewpoint of obtaining good compatibility, the upper limit of the weight average molecular weight of the thermoplastic resin (E) is preferably 200,000 or less, more preferably 180,000 or less, even more preferably 160,000 or less, and still more preferably 150,000 or less. In this embodiment, the weight average molecular weight of the thermoplastic resin (E) can be measured, for example, by gel permeation chromatography (GPC). Specifically, the weight average molecular weight (polystyrene equivalent) of the thermoplastic resin can be measured at a column temperature of 40°C using a measuring device HLC-8320GPC manufactured by Tosoh Corporation, a column ShodeX KF-804 / KF-803 / KF-802 / KF-802 manufactured by Resonac Inc., and tetrahydrofuran or the like as a mobile phase, and can be calculated using a calibration curve of standard polystyrene.

[0106] From the viewpoint of ensuring a sufficient glass transition temperature and strength of the cured product, the thermoplastic resin (E) preferably has a functional group containing one or more atoms selected from the group consisting of oxygen atoms, nitrogen atoms, and sulfur atoms, or a carbon-carbon double bond. Examples of such functional groups include one or more selected from the group consisting of hydroxyl groups, carboxy groups, acid anhydride groups, epoxy groups, amino groups, thiol groups, enol groups, enamine groups, urea groups, cyanate groups, isocyanate groups, thioisocyanate groups, diimide groups, alkenyl groups, allene groups, and ketene groups. The acid anhydride group is preferably a carboxylic acid anhydride group. Suitable examples of alkenyl groups include vinyl groups, allyl groups, and styryl groups. When the thermoplastic resin contains such a functional group, the functional group equivalent of the thermoplastic resin (G) is preferably 100,000 or less, more preferably 90,000 or less, 80,000 or less, 70,000 or less, 60,000 or less, 50,000 or less, 40,000 or less, 30,000 or less, 20,000 or less, 10,000 or less, 8,000 or less, 6,000 or less, or 5,000 or less. The lower limit of the functional group equivalent is not particularly limited, but can usually be 50 or more, 100 or more, etc.

[0107] Suitable thermoplastic resins (E) will be described in more detail below, but thermoplastic resins obtained by further adding the above-mentioned functional groups to the thermoplastic resins shown below according to known procedures can also be suitably used as component (E).

[0108] The phenoxy resin may preferably be one having one or more skeletons selected from the group consisting of a bisphenol A skeleton, a bisphenol F skeleton, a bisphenol S skeleton, a bisphenolacetophenone skeleton, a phenol novolac skeleton, a biphenyl skeleton, a fluorene skeleton, a dicyclopentadiene skeleton, a norbornene skeleton, a naphthalene skeleton, an anthracene skeleton, an adamantane skeleton, a terpene skeleton, and a trimethylcyclohexane skeleton, and the terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. Specific examples of the phenoxy resin include, but are not limited to, Mitsubishi Chemical Corporation's product names: 1256, 4250 (phenoxy resin containing a bisphenol A skeleton), YX8100 (phenoxy resin containing a bisphenol S skeleton), YX6954, YX6954BH30 (phenoxy resin containing a bisphenol acetophenone skeleton), YX7553, YX7553BH30 (phenoxy resin containing a biscresol fluorenone skeleton), YL6794 (phenoxy resin containing a terpene skeleton), YL7213, YL7290 (phenoxy resin containing a trimethylcyclohexane skeleton), YL7500BH30, YL7769BH30, YL7482; and Nippon Steel Chemical & Material Co., Ltd.'s product names: FX280, FX293 (phenoxy resin containing a bisphenol fluorenone skeleton).

[0109] Specific examples of polyvinyl acetal resins include, but are not limited to, Denka Butyral 4000-2, 5000-A, 6000-C, and 6000-EP, both of which are trade names of Denki Kagaku Kogyo Co., Ltd., and S-LEC BH series, BX series, KS series (e.g., KS-1), BL series, and BM series, both of which are trade names of Sekisui Chemical Co., Ltd.

[0110] The acid anhydride group-containing vinyl resin is not particularly limited, but can be obtained, for example, by copolymerizing an acid anhydride group-containing monomer (d1) with another monomer (d2). The acid anhydride group-containing monomer (d1) is not particularly limited, but examples thereof include maleic anhydride, itaconic anhydride, citraconic anhydride, and aconitic anhydride. The other monomer (d2) is not particularly limited as long as it can be copolymerized with the acid anhydride group-containing monomer (d1), and for example, an ethylenically unsaturated monomer such as (meth)acrylic acid, a (meth)acrylic acid ester, or styrene may be used. Specific examples of the acid anhydride group-containing vinyl resin are not particularly limited, but examples thereof include Cray Valley Corporation's product names: EF-30, EF-40, EF-60, and EF-80.

[0111] Specific examples of polyimide resins include, but are not limited to, trade names Rikacoat SN-20 and PN-20 manufactured by New Japan Chemical Co., Ltd., and trade name Unidic V-8000 manufactured by DIC Corporation. Specific examples of polyimide resins also include linear polyimides obtained by reacting bifunctional hydroxyl group-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride (JP 2006-37083 A), and modified polyimides such as polysiloxane skeleton-containing polyimides (JP 2002-12667 A, JP 2000-319386 A, WO 2010 / 53186, etc.).

[0112] Specific examples of polyamide-imide resins include, but are not limited to, Viromax HR11NN and HR16NN (trade names) manufactured by Toyobo Co., Ltd., and HPC-5020, HPC-6000, HPC-7200, and HPC-9000 (trade names) manufactured by Resonac Corporation.

[0113] The styrene-based elastomer resin is not particularly limited, but examples thereof include block copolymers containing a block of styrene or an analog thereof as at least one terminal block and an elastomer block of a conjugated diene or its hydrogenated product as at least one intermediate block. Specific examples include styrene-butadiene diblock copolymers, styrene-butadiene triblock copolymers, styrene-isoprene diblock copolymers, styrene-isoprene triblock copolymers, hydrogenated styrene-butadiene diblock copolymers, hydrogenated styrene-butadiene triblock copolymers, hydrogenated styrene-isoprene diblock copolymers, hydrogenated styrene-isoprene triblock copolymers, and hydrogenated styrene-butadiene random copolymers. Specific examples of the styrene-based elastomer resin are not particularly limited, but examples include Asahi Kasei Corporation's Asaprene, Tufprene, and Asaflex products, and Kuraray Co., Ltd.'s Hybler and Septon products.

[0114] Specific examples of polyethersulfone resins include, but are not limited to, PES5003P, a product of Sumitomo Chemical Co., Ltd.

[0115] Specific examples of polysulfone resins include, but are not limited to, trade names of Polysulfone P1700 and P3500 manufactured by Solvay Advanced Polymers.

[0116] Specific examples of polybutadiene resins include, but are not limited to, trade names G-1000, G-3000, GI-1000, and GI-3000 manufactured by Nippon Soda Co., Ltd., trade name R-45EPI manufactured by Idemitsu Petrochemical Co., Ltd., trade name Epofriend AT501 manufactured by Daicel Corporation, and trade names Ricon 130, Ricon 142, Ricon 150, Ricon 657, and Ricon 130MA manufactured by Cray Valley Corporation.

[0117] Specific examples of the acrylic resin include, but are not limited to, Nagase ChemteX Corporation's product names: SG-P3, SG-600LB, SG-280, SG-790, and SG-K2; and Negami Chemical Industrial Co., Ltd.'s product names: SN-50, AS-3000E, and ME-2000.

[0118] In particular, from the viewpoints of ensuring a sufficient glass transition temperature and strength of the cured layer obtained using the epoxy resin composition of the present embodiment, ensuring long-term connection reliability, and maintaining appropriate compatibility with the epoxy resin (A) and ensuring curing uniformity, it is preferable that the thermoplastic resin (E) contains one or more resins selected from the group consisting of phenoxy resins, polyvinyl acetal resins, acid anhydride group-containing vinyl resins, polyimide resins, polyamide-imide resins, styrene-based elastomer resins, and acrylic resins.

[0119] Furthermore, when the epoxy resin composition of this embodiment is used in materials that are folded and incorporated into electronic devices, such as flexible wiring boards, the inclusion of a thermoplastic resin (E) can reduce the elasticity of the cured layer of the epoxy resin composition, thereby preventing breakage and peeling. For applications requiring such reduced elasticity, the thermoplastic resin (E) is not limited to the following, but for example, a resin having one or more structures selected from a polybutadiene structure, a polysiloxane structure, a poly(meth)acrylate structure, a polyalkylene structure, a polyalkyleneoxy structure, a polyisoprene structure, a polyisobutylene structure, and a polycarbonate structure in the molecule is preferred, as this makes it easier to achieve the reduced elasticity effect. Furthermore, a thermoplastic resin having a glass transition temperature of 25°C or lower or that is liquid at 25°C can also be used preferably from the viewpoint of achieving the same reduced elasticity effect.

[0120] The content of thermoplastic resin (E) in the epoxy resin composition of this embodiment can be appropriately set depending on the types and contents of components (A) to (D) used and the desired performance, and is not particularly limited, but from the viewpoint of ensuring the adhesion and flexibility of the epoxy resin composition of this embodiment, it is preferably 0.5% by mass or more, more preferably 1% by mass or more, even more preferably 1.2% by mass or more, and even more preferably 1.5% by mass or more, of all non-volatile components excluding solvents. From the viewpoints of achieving a high glass transition temperature of the epoxy resin composition of this embodiment, suppressing a decrease in elastic modulus in the high temperature range, and maintaining good strength, it is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, and even more preferably 20% by mass or less.

[0121] (Component (F): Solvent) The epoxy resin composition of this embodiment may further contain a solvent (hereinafter, may be referred to as solvent (F) or component (F)). The inclusion of solvent (F) tends to facilitate uniform dissolution of the compound of component (B) described above in the epoxy resin composition. This improves the curing uniformity of the cured product layer made from the epoxy resin composition of this embodiment, and by selecting component (B) having various structures according to the desired reaction temperature range and reaction rate, it becomes easier to design a composition that can further demonstrate the effects of the present invention.

[0122] The solvent (F) is not particularly limited, and known solvents can be used. Examples of the solvent (F) include, but are not limited to, hydrocarbons such as benzene, toluene, xylene, cyclohexane, mineral spirits, and solvent naphtha; ketones such as acetone, methyl ethyl ketone (MEK), methyl isopropyl ketone, methyl isobutyl ketone, cyclohexanone, and acetophenone; esters such as ethyl acetate, n-butyl acetate, propylene glycol monomethyl ethyl ether acetate, and γ-butyrolactone; alcohols such as methanol, ethanol, isopropanol, n-butanol, butyl cellosolve, butyl carbitol, 2-phenoxyethanol, and 1-methoxy-2-propanol; and amide solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. These may be used alone or in combination of two or more.

[0123] The content of solvent (F) in the epoxy resin composition of this embodiment is not particularly limited, but when the composition is to be used as a varnish or paste by blending the solvent, from the viewpoints of uniformly dissolving the various components and controlling the viscosity within an appropriate range to improve handleability, the content is preferably 5 to 80 mass %, more preferably 10 to 75 mass %, even more preferably 15 to 70 mass %, even more preferably 20 to 65 mass %, and even more preferably 25 to 60 mass % relative to the total epoxy resin composition. Note that when other components contain solvents, such as when component (D) contains a solvent, the above content is a preferred range of the solvent proportion in the total epoxy resin composition, including those solvents.

[0124] Furthermore, when the epoxy resin composition of the present embodiment is formed into a resin film, the content of the solvent (F) is not particularly limited, but from the viewpoint of suppressing the generation of bubbles, it is preferably 10% by mass or less, more preferably 8% by mass or less, and even more preferably 6% by mass or less, based on the total epoxy resin composition. On the other hand, from the viewpoint of preventing a decrease in the adhesion and flexibility of the resin film due to excessive reduction of the solvent, it is preferably 0.001% by mass or more, more preferably 0.01% by mass or more, and even more preferably 0.1% by mass or more, based on the total epoxy resin composition.

[0125] (Component (G): Silane Coupling Agent) The epoxy resin composition of the present embodiment may further contain a silane coupling agent (hereinafter, may be referred to as silane coupling agent (G) or component (G)). By containing the silane coupling agent (G), the affinity between the resin component and the filler, or between the resin component and the substrate to be adhered, can be improved, and there is a tendency for the uniform dispersion of the filler component and the adhesiveness of the epoxy resin composition to be improved, which is preferable.

[0126] In this embodiment, "containing a silane coupling agent (G)" means that in the step of obtaining the epoxy resin composition of this embodiment, the silane coupling agent is incorporated into the composition of the epoxy resin composition by any of the following methods (i) to (iii). Method (i): A method in which the filler (C) is treated with a silane coupling agent and the treated filler is blended into the epoxy resin composition. Method (ii): A method in which the silane coupling agent is directly added to the resin composition (integral blend method). Method (iii): A method in which the silane coupling agent is reacted with the resin terminal or side chain of the epoxy resin (A) or thermoplastic resin (E) used, or a method in which the silane coupling agent is blended as a silylated resin, such as by using a resin obtained by copolymerizing a monomer and a silane coupling agent.

[0127] Any of the above-mentioned methods (i) to (iii) may be used, and method (i) is preferred from the viewpoints that alcohol, which is a by-product of the silane coupling reaction, is less likely to remain in the system and that the dispersibility of the filler is even better, while methods (ii) and (iii) are preferred from the viewpoints that the method can act not only between the resin and the filler but also between the resin and the substrate to be adhered, thereby improving the adhesiveness and adhesion.

[0128] The silane coupling agent (G) is a silicon atom to which at least one hydrolyzable group such as an alkoxy group or an aryloxy group is bonded, and in addition, an alkyl group, an alkenyl group, or an aryl group may be bonded.In addition, the alkyl group may be substituted with an amino group, an alkoxy group, an epoxy group, or a (meth)acryloyloxy group.The silane coupling agent (G) is not limited to the following, but from the viewpoint of improving the uniform dispersion of the filler component and improving the adhesiveness and adhesion of the resin composition, it is preferable to include one or more silane coupling agents selected from, for example, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, styrylsilane coupling agents, acrylate silane coupling agents, isocyanate silane coupling agents, sulfide silane coupling agents, vinylsilane coupling agents, silane coupling agents, organosilazane compounds, and titanate coupling agents.

[0129] The silane coupling agent (G) is not particularly limited, and examples thereof include aminosilane coupling agents such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyldiethoxymethylsilane, N-phenyl-3-aminopropyltrimethoxysilane, N-methylaminopropyltrimethoxysilane, N-2(aminoethyl)-3-aminopropyltrimethoxysilane, and N-(2-aminoethyl)-3-aminopropyldimethoxymethylsilane; epoxysilane coupling agents such as 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyl(dimethoxy)methylsilane, glycidylbutyltrimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; mercaptosilane coupling agents such as 11-mercaptoundecyltrimethoxysilane; styrylsilane coupling agents such as p-styryltrimethoxysilane; acrylate silane coupling agents such as 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-methacryloxypropyldiethoxysilane; 3-isocyanatepropyltrimethoxysilane; Isocyanate silane coupling agents such as silane, sulfide silane coupling agents such as bis(triethoxysilylpropyl) disulfide and bis(triethoxysilylpropyl) tetrasulfide, silane coupling agents such as methyltrimethoxysilane, octadecyltrimethoxysilane, phenyltrimethoxysilane, metachloroxypropyltrimethoxysilane, imidazole silane, triazine silane, and t-butyltrimethoxysilane, hexamethyldisilazane, 1,3-divinyl-1,1,3,3-tetramethyldisilazane, hexaphenyldisilazane, trisilazane, cyclotrisilazane, octamethylcyclotetrasilazane, hexabutyldisilazane, hexaoctyldisilazane, 1,3-diethyltetramethyldisilazane, 1,3-di-n-octyltetramethyldisilazane, 1,3-diphenyltetramethyldisilazane, 1,3-dimethyltetraphenyldisilazane, 1,3-diethyltetramethyldisilazane, 1,1,3,3-tetraphenyl-1,3-dimethyldisilazane, 1,3-dipropyl organosilazane compounds such as methyltetramethyldisilazane, hexamethylcyclotrisilazane, dimethylaminotrimethylsilazane, and tetramethyldisilazane, tetra-n-butyltitanate dimer, titanium-i-propoxyoctylene glycolate, tetra-n-butyltitanate, titanium octylene glycolate, diisopropoxytitanium bis(triethanolaminate), dihydroxytitanium bislactate, dihydroxybis(ammonium lactate)titanium, bis(dioctylpyrophos) phosphate) ethylene titanate, bis(dioctyl pyrophosphate) oxyacetate titanate, tri-n-butoxytitanium monostearate, tetra-n-butyl titanate, tetra(2-ethylhexyl) titanate, tetraisopropyl bis(dioctyl phosphite) titanate, tetraoctyl bis(ditridecyl phosphite) titanate, tetra(2,2-diallyloxymethyl-1-butyl)bis(ditridecyl)phosphite titanate, isopropyl trioctanoyl titanate, Examples of the coupling agent include titanate-based coupling agents such as isopropyl tricumylphenyl titanate, isopropyl triisostearoyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl tri(dioctyl phosphate) titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, and isopropyl tri(N-amidoethyl aminoethyl) titanate.

[0130] Among these, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, and organosilazane compounds are preferred, and from the viewpoint of filler fluidity when used in combination with component (B), aminosilane coupling agents are more preferred. Commercially available products are not particularly limited, but examples include those manufactured by Shin-Etsu Chemical Co., Ltd. under the trade names: KBM403 (3-glycidoxypropyltrimethoxysilane), KBM803 (3-mercaptopropyltrimethoxysilane), KBE903 (3-aminopropyltriethoxysilane), KBM573 (N-phenyl-3-aminopropyltrimethoxysilane), and SZ-31 (hexamethyldisilazane).

[0131] The content of the silane coupling agent (G) in the epoxy resin composition of the present embodiment is not particularly limited, but from the viewpoint of improving the dispersibility of the filler (C) and the adhesiveness and adhesion of the epoxy resin composition of the present embodiment while suppressing excessive side reactions, it is preferably 0.1 to 2.0 parts by mass per 100 parts by mass of the filler (C).

[0132] (Component (H): Non-epoxy-Terminated Compound Having a Polyalkylene Oxide Structure) The epoxy resin composition of the present embodiment may further contain a compound having a polyalkylene oxide structure and a non-epoxy terminal group (non-epoxy-terminated compound having a polyalkylene oxide structure, hereinafter sometimes referred to as component (H)), excluding the above-mentioned components (A) to (G). The inclusion of component (H) tends to alleviate internal stress in the cured product layer and provide the effect of suppressing warpage. From the viewpoint of uniformity of the cured product, component (H) is more preferably a compound having a hydroxyl terminal group.

[0133] Examples of component (H) include, but are not limited to, linear polyalkylene oxide glycols (linear polyalkylene glycols) such as polyethylene glycol, polypropylene glycol, and polyoxyethylene polyoxypropylene glycol; polyoxyethylene glyceryl ether, polyoxypropylene glyceryl ether, polyoxyethylene polyoxypropylene glyceryl ether, polyoxyethylene trimethylolpropane ether, polyoxypropylene trimethylolpropane ether, polyoxyethylene polyoxypropylene trimethylolpropane ether, polyoxyethylene diglyceryl ether, polyoxypropylene diglyceryl ether, polyoxyethylene polyoxypropylene diglyceryl ether, polyoxyethylene pentaerythritol ether, polyoxypropylene pentaerythritol ether, polyoxyethylene polyoxypropylene pentaerythritol ether, polyoxyethylene sorbitol, polyoxypropylene polyalkylene oxide glycols (polyalkylene glycols) such as multi-chain polyalkylene oxide glycols (multi-chain polyalkylene glycols) such as sorbitol and polyoxyethylene polyoxypropylene sorbitol; polyalkylene oxide alkyl ethers such as polyoxyethylene monoalkyl ethers, polyoxyethylene dialkyl ethers, polyoxypropylene monoalkyl ethers, polyoxypropylene dialkyl ethers, polyoxyethylene polyoxypropylene monoalkyl ethers, and polyoxyethylene polyoxypropylene dialkyl ethers; polyalkylene oxide esters (including acetate esters, propionate esters, butyrate esters, (meth)acrylate esters, etc.) such as polyoxyethylene monoesters, polyoxyethylene diesters, polypropylene glycol monoesters, polypropylene glycol diesters, polyoxyethylene polyoxypropylene monoesters, and polyoxyethylene polyoxypropylene diesters;Polyalkylene oxide alkyl ether esters (including acetate esters, propionate esters, butyrate esters, (meth)acrylate esters, etc.) such as polyoxyethylene monoesters, polyoxyethylene diesters, polyoxypropylene monoesters, polyoxypropylene diesters, polyoxyethylene polyoxypropylene monoesters, polyoxyethylene polyoxypropylene diesters, polyoxyethylene alkyl ether esters, polyoxypropylene alkyl ether esters, and polyoxyethylene polyoxypropylene alkyl ether esters; polyalkylene oxide alkylamines such as polyoxyethylene alkylamines, polyoxypropylene alkylamines, and polyoxyethylene polyoxypropylene alkylamines; polyalkylene oxide alkylamides such as polyoxyethylene alkylamides, polyoxypropylene alkylamides, and polyoxyethylene polyoxypropylene alkylamides; polyoxyethylene dimethicone, poly Examples thereof include polyalkylene oxide-modified silicones such as polyoxypropylene dimethicone, polyoxyethylene polyoxypropylene dimethicone, polyoxyethylene polydimethylsiloxyalkyl dimethicone, polyoxypropylene polydimethylsiloxyalkyl dimethicone, and polyoxyethylene polyoxypropylene polydimethylsiloxyalkyl dimethicone; and alkyl etherified polyalkylene oxide-modified silicones (polyalkylene oxide-modified silicones in which at least a portion of the polyether skeleton terminals are alkoxy groups) such as polyoxyethylene alkyl ether dimethicone, polyoxypropylene alkyl ether dimethicone, polyoxyethylene polyoxypropylene alkyl ether dimethicone, polyoxyethylene alkyl ether polydimethylsiloxyalkyl dimethicone, polyoxypropylene alkyl ether polydimethylsiloxyalkyl dimethicone, and polyoxyethylene polyoxypropylene alkyl ether polydimethylsiloxyalkyl dimethicone;

[0134] Specific examples of component (H) include, but are not limited to, "Pronon #102," "Pronon #104," "Pronon #201," "Pronon #202B," "Pronon #204," "Pronon #208," "Unilube 70DP-600B," and "Unilube 70DP-950B" (polyoxyethylene polyoxypropylene glycols) manufactured by NOF Corporation; "Pluronic L-23," "Pluronic L-31," and "Pluronic L-41" manufactured by ADEKA Corporation; Pluronic L-44, Pluronic L-61, Adeka Pluronic L-62, Pluronic L-64, Pluronic L-71, Pluronic L-72, Pluronic L-101, Pluronic L-121, Pluronic P-84, Pluronic P-85, Pluronic P-103, Pluronic F-68, Pluronic F-88, Pluronic F-108, Pluronic 25R-1, Pluronic Luronic 25R-2, Pluronic 17R-2, Pluronic 17R-3, and Pluronic 17R-4 (polyoxyethylene polyoxypropylene glycol); Shin-Etsu Silicone's KF-6011, KF-6011P, KF-6012, KF-6013, KF-6015, KF-6016, KF-6017, KF-6017P, KF-6043, KF-6004, and KF351A ", "KF352A", "KF353", "KF354L", "KF355A", "KF615A", "KF945", "KF-640", "KF-642", "KF-643", "KF-644", "KF-6020", "KF-6204", "X22-4515", "KF-6028", "KF-6028P", "KF-6038", "KF-6048", and "KF-6025" (polyalkylene oxide-modified silicone).

[0135] Component (H) may also contain a compound represented by the following formula (3). (In formula (3), R ３ , R ４ are each independently an alkyl group having 1 to 12 carbon atoms, and R ３ , R ４may be the same or different. p and q are each independently an integer of 1 or more. R ５ , R ６ are each independently one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 6 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent. ５ , R ６ may be the same or different.) In formula (3), p and q are not particularly limited, but from the viewpoint of the balance between the strength and toughness of the cured product, the sum of the number of repetitions thereof, p+q, is preferably 2 or more and 12 or less, more preferably 3 or more and 10 or less, even more preferably 4 or more and 8 or less, and even more preferably 5 or more and 8 or less. The compound represented by formula (3) is preferred because it has excellent compatibility with component (A) and can achieve both heat resistance and strength due to the aromatic ring portion in the structure and low stress and low warpage due to the polyalkylene oxide chain portion.

[0136] Examples of the compound represented by formula (3) include, but are not limited to, trade names of Newpol BPE-20, BPE-40, BPE-60, BPE-100, BPE-180, BP-2P, BP-3P, and BP-5P manufactured by Sanyo Chemical Industries, Ltd. These may be used alone or in combination of two or more.

[0137] Component (H) may be added independently or mixed with a component other than component (H), or may be generated in situ by using a constituent material containing component (H) during the production of component (A) or during the production of an epoxy resin composition containing component (A).

[0138] The content of component (H) in the epoxy resin composition of this embodiment can be appropriately set depending on the desired performance and is not particularly limited, but is preferably 1% by mass or more and 50% by mass or less, more preferably 1.5% by mass or more and 40% by mass or less, and even more preferably 2% by mass or more and 30% by mass or less, of all non-volatile components excluding the solvent. By setting the content of component (H) within the above range, it tends to be possible to achieve both heat resistance and strength, as well as low stress and low warpage.

[0139] (Additives) In addition to the above-described components (A) to (H), the epoxy resin composition of the present embodiment may further contain, as necessary, additives such as diluents, reactive diluents, pigments, dyes, flow modifiers, thickeners, toughening agents, release agents, wetting agents, flame retardants, surfactants, stabilizers, and adhesion aids.

[0140] The diluent is not limited to, but includes, for example, dioctyl phthalate, dibutyl phthalate, benzyl alcohol, and the like.

[0141] The reactive diluent is a compound having a reactive functional group that can be incorporated into the cured structure of an epoxy group, an acrylic group, or the like, and is a compound that has the effect of lowering the viscosity of the epoxy resin composition when added to the epoxy resin composition of this embodiment. Examples of the reactive diluent include, but are not limited to, acrylate compounds and epoxy compounds that can lower the viscosity without impairing reactivity.

[0142] Examples of the acrylate compound that is a reactive diluent include, but are not limited to, a compound having (meth)acryloyl groups at both ends of a polyalkylene oxide, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, polybutylene glycol di(meth)acrylate, trimethylolpropane-type polyfunctional (meth)acrylate, pentaerythritol-type polyfunctional (meth)acrylate, and dipentaerythritol-type polyfunctional (meth)acrylate.

[0143] Examples of the epoxy compound that is a reactive diluent include, but are not limited to, n-butyl glycidyl ether, tert-butyl glycidyl ether, diglycidyl aniline, N,N'-glycidyl-o-toluidine, phenyl glycidyl ether, cresyl glycidyl ether, p-tert-butylphenyl glycidyl ether, styrene oxide, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, and 1,6-hexanediol diglycidyl ether.

[0144] Various monoepoxy compounds and glycidyl ether compounds of polyhydric alcohols can also be used as reactive diluents, but since each molecule contains only one functional group (epoxy group, glycidyl group) that contributes to the reaction with component (B) and component (D), and although they do not volatilize and cause voids, they tend to be unable to form three-dimensional crosslinks upon curing, which makes it difficult to obtain sufficient glass transition temperatures and toughness for the epoxy resin composition. Therefore, from the perspective of being able to form three-dimensional crosslinks upon curing, compounds containing two or more glycidyl groups per molecule are preferred as reactive diluents. The reactive diluents may be used alone or in combination of two or more.

[0145] The content of the reactive diluent can be appropriately set depending on the desired performance and is not particularly limited, but is preferably 1.0 part by mass or more and 30 parts by mass or less per 100 parts by mass of the epoxy resin (A). A content of 1.0 part by mass or more tends to provide sufficiently low-viscosity curing, and tends to improve the filling ability of the resin paste into gaps and the adhesion of the resin film. On the other hand, a content of the reactive diluent of 30 parts by mass or less per 100 parts by mass of the epoxy resin (A) tends to prevent creeping of the resin paste or leakage to unintended locations due to excessively low viscosity, improve the dimensional stability of the resin film, and suppress peeling during a moisture absorption reflow test. It is also preferable to further contain a reactive diluent in order to suppress the increase in viscosity that occurs when the filler (C) is highly loaded.

[0146] Examples of pigments include, but are not limited to, kaolin, chalk powder, gypsum, antimony trioxide, pentone, aerosol, lithopone, baryte, and titanium dioxide.

[0147] Examples of dyes include, but are not limited to, natural dyes such as plant-derived dyes such as madder and indigo, and mineral-derived dyes such as yellow ochre and red clay, synthetic dyes such as alizarin and indigo, and fluorescent dyes.

[0148] Examples of flow control agents include, but are not limited to, organic titanium compounds such as titanium tetraisopropoxide and titanium diisopropoxybis(acetylacetonate); and organic zirconium compounds such as zirconium tetra-normal-butoxide and zirconium tetraacetylacetonate.

[0149] Examples of thickeners include, but are not limited to, animal-based thickeners such as gelatin; plant-based thickeners such as polysaccharides and cellulose; and chemically synthesized thickeners such as polyacrylics, modified polyacrylics, polyethers, urethane-modified polyethers, and carboxymethylcellulose.

[0150] Examples of the reinforcing agent include, but are not limited to, polyethylene sulfone powder such as "Sumikaexcel PES" manufactured by Sumitomo Chemical Co., Ltd.; nano-sized functional group-modified core-shell rubber particles such as "Kane Ace MX" manufactured by Kaneka Corporation; and silicone-based reinforcing agents such as polyorganosiloxane.

[0151] Examples of the release agent include, but are not limited to, fluorine-based release agents, silicone-based release agents, and acrylic release agents made of a copolymer of glycidyl (meth)acrylate and a linear alkyl (meth)acrylate having 16 to 22 carbon atoms.

[0152] Examples of wetting agents include, but are not limited to, unsaturated polyester copolymer wetting agents having acidic groups, such as acrylic polyphosphate esters.

[0153] Examples of flame retardants include, but are not limited to, bromine-based flame retardants, phosphorus-based flame retardants, and inorganic flame retardants. Examples of bromine-based flame retardants include, but are not limited to, tetrabromophenol. Examples of phosphorus-based flame retardants include, but are not limited to, 9,10-dihydro-9-oxa-10-phosphananthrene-10-oxide and its epoxy derivatives, triphenylphosphine and its derivatives, phosphate esters, condensed phosphate esters, and phosphazene compounds. Examples of nitrogen-based flame retardants include, but are not limited to, melamine polyphosphate, isocyanuric acid, guanidine-based flame retardants, and triazine-based flame retardants. Examples of inorganic flame retardant compounds include, but are not limited to, magnesium hydroxide and aluminum hydroxide. Note that one type of flame retardant may be used alone, or two or more types may be used in combination. The content of the flame retardant is not particularly limited, but is preferably 5.0 parts by mass or more and 200 parts by mass or less, and more preferably 10 parts by mass or more and 100 parts by mass or less, relative to the mass (100 parts by mass) of the epoxy resin (A).

[0154] Examples of surfactants include, but are not limited to, anionic surfactants such as alkylbenzene sulfonates and alkyl polyoxyethylene sulfates, cationic surfactants such as alkyl dimethyl ammonium salts, amphoteric surfactants such as alkyl dimethyl amine oxides and alkyl carboxy betaines, and nonionic surfactants such as linear alcohols and fatty acid esters having 25 or more carbon atoms.

[0155] As stabilizers that improve the storage stability of epoxy resin compositions, for example, boric acid, cyclic borate ester compounds, isocyanuric acid, barbituric acid, aluminum chelating agents, etc. can be suitably used, but are not limited to these. A cyclic borate ester compound is one in which boron is contained in a cyclic structure. From the viewpoints of compatibility with the resin and uniformity of curing, the cyclic borate ester compound is preferably 2,2'-oxybis(5,5'-dimethyl-1,3,2-oxaborinane). Note that one stabilizer may be used alone, or two or more stabilizers may be used in combination.

[0156] A wide variety of adhesion aids can be used as long as they are components that are added for the purpose of forming coordinate bonds with metals or substrate materials or improving affinity. However, from the viewpoint of further obtaining the effect of forming a good coating on the surface of the adherend and improving adhesion, thiazole-based compounds and triazole-based compounds are preferred.

[0157] The additives described above can be added in functionally equivalent amounts, for example, pigments and / or dyes can be added in amounts that can impart a desired color to the epoxy resin composition of the present embodiment. In addition, a person skilled in the art can appropriately determine the amount of additives to be added depending on the formulation and the desired performance.

[0158] [Epoxy Resin Composition and Resin Paste Using the Same] The epoxy resin composition of this embodiment and the resin paste using the same contain the above-described component (A) and component (B), and can be obtained by adding, as necessary, components (C) to (G) and the above-described additives, and mixing them. That is, the resin paste of this embodiment contains the epoxy resin composition of this embodiment. The mixing method is not particularly limited, and methods known to those skilled in the art can be applied. For example, the composition can be obtained by thoroughly mixing until homogeneous using, but not limited to, a mixing roll such as a three-roll mixer, a dissolver, a planetary mixer, a rotary mixer, a kneader, an extruder, or the like.

[0159] (Specific Aspects of Epoxy Resin Composition and Resin Paste Using the Same) The epoxy resin composition of the present embodiment is completely uniform and has sufficient filling properties. Even when a polyfunctional epoxy resin is blended, the epoxy resin composition has a high glass transition temperature and is capable of suppressing a decrease in elastic modulus at high temperatures. Therefore, the epoxy resin composition can be suitably used as a resin paste for underfill materials, sealing materials for electric and electronic components such as relay sealing materials, paste materials such as various insulating liquid adhesives, die attach pastes, conductive pastes, and thermally conductive pastes, ink materials such as solder resist inks and hole-filling inks, matrix resins for fiber-reinforced plastics, and impregnation and fixing materials for motor coils. For example, in underfill materials, the epoxy resin composition of the present embodiment has completely uniformity and sufficient filling properties, ensuring permeability when heated and infiltrated between a semiconductor chip and a substrate. In addition, the epoxy resin composition can fill large-area semiconductor chips and narrow gaps in particular. In addition, the epoxy resin composition exhibits a high glass transition temperature and suppresses a decrease in elastic modulus at high temperatures. This makes the epoxy resin composition more suitable for providing underfill materials and semiconductor devices that are highly resistant to heat generation and long-term use of electronic components and have excellent long-term connection reliability. Furthermore, for example, in paste materials and ink materials such as die attach paste, conductive paste, and thermally conductive paste, the completely uniform epoxy resin composition of this embodiment does not leave any residual particles when the paste or ink is applied or filled, and a cured product with high curing uniformity is obtained, which is superior in strength and long-term durability, making it more suitable. Furthermore, by appropriately selecting the filler (C) used in this embodiment depending on the application and blending one or more types of silica, conductive filler, or thermally conductive filler, it is possible to impart the desired die attachability, electrical conductivity, and thermal conductivity while obtaining the effects of the present invention.

[0160] [Resin Film] The epoxy resin composition of this embodiment can be made into a resin film. The resin film of this embodiment has a support and a resin layer containing the above-mentioned epoxy resin composition on the support. Specifically, the resin film of this embodiment has, for example, a predetermined support and a resin layer formed on the support from the above-mentioned epoxy resin composition, and may have a protective layer as needed. Specifically, for example, a protective layer may be provided on the surface of the resin layer opposite the support.

[0161] (Support) The support constituting the resin film is preferably a material that can withstand the temperature during solvent drying.Such a support is not limited to the following, but includes, for example, polyethylene terephthalate film, polyvinyl alcohol film, polyvinyl chloride film, vinyl chloride copolymer film, polyvinylidene chloride film, vinylidene chloride copolymer film, polymethyl methacrylate copolymer film, polystyrene film, polyacrylonitrile film, styrene copolymer film, polyamide film, cellulose derivative film, etc.As these films, stretched films can also be used as needed.

[0162] (Protective Layer) The protective layer is preferably made of a material capable of sufficiently maintaining the smoothness of the surface of the resin layer constituting the resin film. Examples of such a protective layer include, but are not limited to, polyethylene film, polypropylene film, polyethylene terephthalate film treated for easy peeling, and oriented polypropylene film.

[0163] (Method for Producing Resin Film) The resin film of this embodiment can be produced by sequentially laminating a support, a resin layer, and, if necessary, a protective layer. Known methods can be used to laminate the support, resin layer, and protective layer. Specifically, without particular limitation, for example, the epoxy resin composition of this embodiment containing the solvent (F) is prepared, and then coated on the support using a known method such as an applicator, bar coater, lip coater, die coater, roll coater, or doctor blade coater, followed by drying to form a resin layer on the support. The drying method is not particularly limited, but examples include oven drying and hot air blowing. The drying temperature and time are also not particularly limited. However, from the viewpoint of thoroughly removing the solvent and suppressing deformation of the support due to excessive heating and excessive reaction of the resin layer during drying, drying at a temperature within a range of 50°C to 160°C for 1 to 30 minutes is preferred, and drying at 80°C to 150°C for 3 to 25 minutes is more preferred. The drying temperature may be constant or a temperature gradient may be applied. Next, if necessary, a protective layer is laminated on the formed resin layer, thereby producing a resin film.

[0164] (Specific Aspects of Resin Film) The resin film of this embodiment can be used, for example, as an interlayer insulating film, a film-type solder resist, an encapsulating sheet, a die attach film, a conductive film, an anisotropic conductive film, a non-conductive film, a thermally conductive film, and the like, but is not limited thereto. A resin film using the epoxy resin composition of this embodiment not only exhibits various stabilities required in the production of resin films, such as varnish storage stability until coating and drying, stability at drying temperatures, and film storage stability, but also has sufficient filling properties, low warpage of the cured layer, a high glass transition temperature, and the ability to suppress a decrease in elastic modulus in high temperature ranges. Therefore, this is particularly effective for materials such as resin films, for which reliability must be ensured in a thin cured layer. Furthermore, because component (B) dissolves uniformly in the epoxy resin composition or solvent, the resin film has excellent surface smoothness and can be adhered to a substrate without gaps. The above-mentioned properties are commonly required for interlayer insulating films, film-type solder resists, encapsulating sheets, die attach films, conductive films, anisotropic conductive films, non-conductive films, thermally conductive films, and the like, and therefore the resin film of this embodiment is suitable for these aspects.

[0165] [Cured Product] The cured product of the present embodiment is obtained by curing the above-described epoxy resin composition.

[0166] [Semiconductor Device] The semiconductor device of this embodiment includes a semiconductor element sealed or bonded using the above-described resin paste, or a semiconductor element sealed or bonded using the above-described resin film. Accordingly, the semiconductor device of this embodiment has a cured product layer of the above-described epoxy resin composition. By using the epoxy resin composition of this embodiment, uniform sealing or bonding is achieved, and the cured product layer exhibits a high glass transition temperature and suppresses a decrease in elastic modulus in the high temperature range, which is preferable because it allows the production of a semiconductor device with excellent reliability that can withstand heat generation and long-term use.

[0167] The semiconductor device is not particularly limited as long as it is a device that functions by incorporating semiconductor components, and examples thereof include various semiconductor devices used in electrical appliances such as personal computers, smartphones, game consoles, digital cameras, and televisions, vehicles such as motorcycles, automobiles, trains, ships, and aircraft, and high-speed communication antennas, servers, etc.

[0168] The semiconductor device of this embodiment is not particularly limited, but can be manufactured by, for example, mounting various semiconductor chips at the locations of a wiring board where circuit connections are made, thereby establishing electrical continuity.

[0169] The method for mounting a semiconductor chip when manufacturing a semiconductor device is not particularly limited, but specific examples include a wire bonding mounting method, a flip chip mounting method, a mounting method using a bumpless build-up layer (BBUL), a mounting method using an anisotropic conductive film, and a mounting method using a non-conductive film. In mounting, the epoxy resin composition of the present embodiment, and a resin paste or resin film using the same can be used to seal, bond, etc. the semiconductor chip.

[0170] Hereinafter, the present embodiment will be described with reference to specific examples and comparative examples, but the present invention is not limited to the following examples and comparative examples and can be appropriately modified within the scope of the invention. In the following, "parts" and "%" are based on mass unless otherwise specified.

[0171] [Preparation of Epoxy Resin Composition] Each component was weighed out so as to obtain the blending numbers shown in Tables 1 and 2 below, and mixed until sufficiently uniform to obtain an epoxy resin composition.

[0172] (Calculation of parameter α (reaction sensitivity) of epoxy resin composition) For the above-mentioned epoxy resin composition, two points, 130°C and 150°C, were selected as T, and the viscosity of the epoxy resin composition was measured continuously using a rheometer under constant temperature and oscillation (f = 1 Hz) conditions at each point. The time t minutes until the viscosity reached 10,000 Pa s was measured, based on the temperature T°C (130°C or 150°C). The measuring device used was a HAAKE MARS manufactured by Thermo Scientific. When component (F) solvent was contained, the epoxy resin composition was heated at 130°C or 150°C for 3 minutes to volatilize the solvent, and the above measurement was performed on the epoxy resin composition. Next, with 1 / T on the horizontal axis and Lnt on the vertical axis, the values ​​of Lnt versus 1 / T obtained as above were plotted, and a straight line approximation was created for the plotted data points by the least squares method, and α was calculated as the slope of the straight line. However, if the viscosity did not reach 10,000 Pa·s even after 30 minutes at 130°C, the epoxy resin composition was judged to have insufficient reaction sensitivity within a practical temperature range, and was recorded as "ineligible for evaluation" in the table.

[0173] [Methods for measuring and evaluating properties] (Evaluation of uniformity: visual inspection) Each component except for component (C) in Tables 1 and 2 was weighed and mixed until sufficiently uniform, to obtain an epoxy resin composition not containing component (C). The resulting resin composition was transferred to a transparent plastic container and visually observed from the side. If the composition was completely transparent and free of areas with different color tones, layer separation, or floating or settled solid components, the uniformity of the composition was evaluated as good, and this was indicated by ○ in the tables. If the composition was opaque or had areas with different color tones, layer separation, or floating or settled solid components, the uniformity of the composition was evaluated as poor, and this was indicated by × in the tables.

[0174] (Evaluation of Filling Property: Measurement of 130°C Low Viscosity Retention Time) The prepared epoxy resin compositions were subjected to continuous viscosity measurement using a rheometer at a constant temperature of 130°C and under oscillation (f = 1 Hz) conditions, and the time from when the resin composition reached its minimum viscosity until it reached a viscosity 10 times the minimum viscosity was measured. The measuring device used was a HAAKE MARS manufactured by Thermo Scientific. When component (F) solvent was contained, the resin composition was heated at 130°C for 3 minutes to volatilize the solvent, and the measurement was performed on the resin composition. With regard to filling property, a sample that took 5 minutes or more to reach 10 times the viscosity was evaluated as good, and is indicated by ○ in the table, and a sample that took less than 5 minutes to reach 10 times the viscosity was evaluated as poor, and is indicated by × in the table.

[0175] (Evaluation of Heat Resistance: Measurement of Glass Transition Temperature) For the epoxy resin compositions prepared in Examples 1 to 10 and Comparative Examples 1 to 8, a U-shaped Teflon (registered trademark) mold was sandwiched between two aluminum plates (750 mm long x 750 mm wide x 0.5 mm thick) that had been pre-coated with a release agent to prepare a mold with a gap (550 mm long x 350 mm wide x 2 mm thick). The epoxy resin composition was poured fully into the opening and heat-cured for 1 hour in an oven preheated to 150°C. For Examples 11 to 14 and Comparative Examples 9 to 12, an epoxy resin composition layer was applied to the center of an aluminum foil (15 cm long, 8 cm wide, and 1.7 mm thick) to a length of 12 cm, a width of 5 cm, and a dry film thickness of 150 μm. The layer was then heated and dried for 5 minutes in an oven preheated to 120°C to form a film, which was then heat-cured for 1 hour in an oven preheated to 150°C. For each cured product obtained after removal from the Teflon (registered trademark) mold or aluminum foil, DMA measurement (RSA-G2, manufactured by TA Instruments, Inc.) was performed at a temperature increase rate of 4°C / min from 25°C to 250°C, and the temperature at which tan δ reached a maximum was taken as the glass transition temperature. Glass transition temperatures of 150°C or higher but lower than 200°C were evaluated as good, and temperatures of 200°C or higher were evaluated as better. However, if tan δ did not reach a maximum between 25°C and 250°C, the glass transition temperature was recorded as >250 in the table. Furthermore, if the cured product was brittle and test specimens could not be prepared, the table recorded "ineligible for evaluation."

[0176] (Evaluation of Reliability: Measurement of Elastic Modulus Retention Rate Across the Glass Transition Temperature) An epoxy resin composition was cured by the method described above in (Evaluation of Heat Resistance) to obtain a cured product, and then DMA measurement (RSA-G2, manufactured by TA Instruments, Inc.) was performed at a temperature rise rate of 4°C / min from 25°C to 250°C to measure the storage modulus at 25°C (room temperature elastic modulus) and the minimum value of the storage modulus in the temperature range equal to or higher than the glass transition temperature measured in (Evaluation of Heat Resistance) above (high temperature storage elastic modulus), and the elastic modulus retention rate across the glass transition temperature was calculated using the following formula (1): Elastic Modulus Retention Rate (%) = High Temperature Storage Elastic Modulus / Room Temperature Elastic Modulus × 100 Formula (1) An elastic modulus retention rate of more than 10% was evaluated as good, and is indicated by ○ in the tables, and an elastic modulus retention rate of 10% or less was evaluated as poor, and is indicated by × in the tables. However, when the cured product was too brittle to prepare a test piece, the table states that evaluation was not possible.

[0177] [Component Description] The components used in the epoxy resin compositions of the Examples and Comparative Examples are shown in Tables 1 and 2 below.

[0178] (Component (A): Epoxy resin) A-1: ​​jER630LSD (glycidylamine type epoxy resin, trifunctional, epoxy equivalent 95 g / eq, manufactured by Mitsubishi Chemical Corporation) A-2: jER1032H60 (triphenylmethane type epoxy resin, trifunctional, epoxy equivalent 169 g / eq, manufactured by Mitsubishi Chemical Corporation) A-3: CNE220 (o-cresol novolac type epoxy resin, multifunctional (trifunctional or more), epoxy equivalent 220 g / eq, manufactured by Chang Chun Synthetic Resin Co., Ltd.) A-4: jER828 (BisA type liquid epoxy resin, bifunctional, epoxy equivalent 190 g / eq, manufactured by Mitsubishi Chemical Corporation) A-5: EXA850CRP (BisA type liquid epoxy resin, bifunctional, epoxy equivalent 186 g / eq, manufactured by DIC Corporation) A-6: EXA830CRP (BisF type liquid epoxy resin, bifunctional, epoxy equivalent 160 g / eq, manufactured by DIC Corporation) A-7: HP4032D (naphthalene type liquid epoxy resin, bifunctional, epoxy equivalent 142 g / eq, manufactured by DIC Corporation) A-8: YX7400N (polytetramethylene glycol diglycidyl ether, bifunctional, epoxy equivalent 440 g / eq, manufactured by Mitsubishi Chemical Corporation) A-9: GOT (glycidylamine type liquid epoxy resin, bifunctional, epoxy equivalent 135 g / eq, manufactured by Nippon Kayaku Co., Ltd.) A-10: CDMDG (cyclohexanedimethanol diglycidyl ether, bifunctional, epoxy resin also used as a reactive diluent, epoxy equivalent 136 g / eq, manufactured by Resonac Corporation) A-11: AER9000 (specially modified epoxy resin, bifunctional, epoxy equivalent 370 g / eq, manufactured by Asahi Kasei Corporation) A-12: Ogusol EG-280 (fluorene-type liquid epoxy resin, bifunctional, epoxy equivalent 494 g / eq, manufactured by Osaka Gas Chemicals Co., Ltd.)

[0179] (Component (B): Compounds represented by general formula (1) and general formula (2)) B-1: 2-(2-hydroxyphenyl)imidazole (manufactured by Ambeed, Inc.) B-2: 2-(2-hydroxyphenyl)benzimidazole (manufactured by Tokyo Chemical Industry Co., Ltd.)

[0180] (Compounds not corresponding to component (B)) R-1: 2MZ-A (2,4-diamino-6-[2-(2-methyl-1-imidazolyl)ethyl]-1,3,5-triazine, manufactured by Shikoku Chemical Holdings Co., Ltd.) R-2: 2MA-OK (2,4-diamino-6-[2-(2-methyl-1-imidazolyl)ethyl]-1,3,5-triazine isocyanuric acid adduct, manufactured by Shikoku Chemical Holdings Co., Ltd.) R-3: 2P4MZ (2-phenyl-4-methylimidazole, manufactured by Shikoku Chemical Holdings Co., Ltd.) R-4: 1B2PZ (1-benzyl-2-phenylimidazole, manufactured by Shikoku Chemical Holdings Co., Ltd.) R-5: 2P4MHZ (2-phenyl-4-methyl-5-hydroxymethylimidazole, manufactured by Shikoku Chemical Holdings Co., Ltd.) R-6: KAYAHARD AA (3,3'-diethyl-4,4'-diamino-diphenylmethane, manufactured by Nippon Kayaku Co., Ltd.) R-7: ETHACURE 100 (diethyltoluenediamine, manufactured by Mitsui Fine Chemicals, Inc.)

[0181] (Component (C): Filler) C-1: SO-E2 (spherical silica filler, average particle size 0.5 μm, manufactured by Admatechs Co., Ltd.)

[0182] (Component (D): Other curing agents) D-1: MEH-8000H (liquid phenol novolac resin curing agent, OH group equivalent 140 g / eq, manufactured by UBE) D-2: HF-1M (solid phenol novolac resin curing agent, OH group equivalent 106 g / eq, manufactured by UBE)

[0183] (Component (E): Thermoplastic resin) E-1: PKHB (phenoxy resin, weight average molecular weight 32,000, manufactured by Gabriel PhenoXies)

[0184] (Component (F): Solvent) F-1: Methyl ethyl ketone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) F-2: Cyclohexanone (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0185] (Component (G): Silane coupling agent) G-1: KBM-573 (aminosilane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0186] (Component (H): Non-epoxy-terminated compound having a polyalkylene oxide structure) H-1: BPE-100 (bisphenol A ethylene oxide 10 mol adduct, liquid at 25°C, hydroxyl group structure at both ends, manufactured by Sanyo Chemical Industries, Ltd.)

[0187] [Examples 1 to 14], [Comparative Examples 1 to 12] Epoxy resin compositions were prepared by the above-mentioned method, blending the components in the proportions (parts by mass) shown in Tables 1 and 2. The properties of the prepared epoxy resin compositions were measured and evaluated by the above-mentioned methods. The results are shown in Tables 1 and 2.

[0188]

[0189]

[0190] The examples using component (B) in combination with a trifunctional or higher polyfunctional epoxy resin and with a parameter α satisfying the condition 690≦α≦1000 all had sufficient uniformity and filling ability, and the glass transition temperature exceeded 150°C, with Examples 1 to 8 exceeding 200°C. The examples were also found to have sufficient elastic modulus retention. In Comparative Examples 1 to 4 and 10 to 12, which used a compound not corresponding to component (B), despite the use of a polyfunctional epoxy resin, the glass transition temperature was lowered to a maximum of around 60°C compared to the examples using component (B), and the elastic modulus retention was also insufficient. In Comparative Examples 8 and 9, although the glass transition temperature was sufficient, both uniformity and filling ability were insufficient. Comparative Example 5, which used component (B) but did not use a polyfunctional epoxy resin, failed to provide satisfactory filling ability or elastic modulus retention. Furthermore, Comparative Example 6, which used component (B) but did not use a polyfunctional epoxy resin, failed to provide satisfactory glass transition temperature or elastic modulus retention. Furthermore, it was found that in Comparative Example 7, in which the parameter α did not satisfy the condition of 690≦α≦1000, even when component (B) and a multifunctional epoxy resin were used, the filling ability was insufficient. As described above, it was found that the examples containing a tri- or higher functional multifunctional epoxy resin and component (B) and in which the parameter α satisfied the condition of 690≦α≦1000 were able to obtain homogeneous epoxy resin compositions and to achieve good filling ability, glass transition temperature, and elastic modulus retention, thereby exhibiting exceptional effects.

[0191] This application is based on a Japanese patent application (Patent Application No. 2023-207573) filed on December 8, 2023, the contents of which are incorporated herein by reference.

[0192]

[0023] The epoxy resin composition of the present invention is completely uniform and has sufficient filling properties. When a polyfunctional epoxy resin is blended therewith, the epoxy resin composition not only has a significantly high glass transition temperature that exceeds the curing temperature, but also is able to suppress a decrease in elastic modulus at high temperatures, and therefore has high heat resistance and excellent reliability that enables it to withstand long-term use. The epoxy resin composition of the present invention has industrial applicability in, for example, sealing materials for electric and electronic components such as underfill materials and relay sealing materials; paste materials such as various insulating liquid adhesives, die attach pastes, conductive pastes and thermally conductive pastes; ink materials such as solder resist inks and hole-filling inks; resin paste materials such as matrix resins for fiber-reinforced plastics and impregnating and fixing materials for motor coils; and film materials such as interlayer insulating films, film-type solder resists, sealing sheets for semiconductor packages, die attach films, conductive films, anisotropically conductive films, non-conductive films and thermally conductive films.

Claims

1. An epoxy resin composition comprising: component (A): an epoxy resin; and component (B): a compound represented by the following formula (1) and / or a compound represented by the following formula (2), wherein component (A) comprises at least one polyfunctional epoxy resin having three or more functionalities, and wherein, when maintained at a constant temperature T°C satisfying 130≦T≦150, the slope α of the straight line obtained by plotting Lnt (vertical axis) against 1 / T (horizontal axis) satisfies 690≦α≦1000, where t is the time it takes for the viscosity to reach 10,000 Pa s from the time when the temperature T°C is reached as a reference temperature when the composition is maintained at a constant temperature T°C satisfying 130≦T≦150. (In formula (1), R １ , R ２ are each independently any one selected from the group consisting of a hydrogen atom, a hydroxyl group, a carboxy group, a cyano group, a nitro group, a halogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, and a cycloalkyl group having 6 to 20 carbon atoms which may have a substituent; R １ , R ２ may be the same or different, R １ , R ２ may be bonded to form a fused ring having no aromaticity, X is any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent, and a heteroarylalkyl group having 4 to 20 carbon atoms which may have a substituent, Y is any one selected from the group consisting of a hydrogen atom, a halogen atom, a hydroxyl group, a carboxy group, a cyano group, a nitro group, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, and an acyl group having 1 to 20 carbon atoms which may have a substituent, when there are a plurality of Y's, they may be the same or different, and two or more Y's may be bonded to each other to form a monocycle or a condensed ring, and m is an integer of 1 to 4. (In formula (2), X is any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aralkyl group having 7 to 20 carbon atoms which may have a substituent, and a heteroarylalkyl group having 4 to 20 carbon atoms which may have a substituent, Y and Z are any one selected from the group consisting of a hydrogen atom, a halogen atom, a hydroxyl group, a carboxy group, a cyano group, a nitro group, an alkyl group having 1 to 20 carbon atoms which may have a substituent, an alkoxy group having 1 to 20 carbon atoms which may have a substituent, an alkenyl group having 2 to 20 carbon atoms which may have a substituent, an aryl group having 6 to 20 carbon atoms which may have a substituent, an aryloxy group having 6 to 20 carbon atoms which may have a substituent, and an acyl group having 1 to 20 carbon atoms which may have a substituent, Y and Z may be the same or different, two or more Ys and two or more Zs may be bonded to each other to form a monocycle or a condensed ring, and m and n are each independently an integer of 1 to 4.

2. The epoxy resin composition according to claim 1, wherein the component (A) further contains an epoxy resin having two or less functionalities.

3. The epoxy resin composition according to claim 2, wherein the blending ratio (mass ratio) of the trifunctional or higher polyfunctional epoxy resin to the difunctional or lower epoxy resin is in the range of 1:0.1 to 1:

10.

4. The resin composition according to claim 1, wherein the component (A) comprises an epoxy resin having an aromatic ring.

5. The resin composition according to claim 1, wherein the component (A) comprises an epoxy resin having no aromatic ring.

6. In the above-mentioned component (B), in formula (1), Y is one selected from the group consisting of a hydrogen atom, a hydroxyl group, a carboxy group, an alkoxy group having 1 to 20 carbon atoms and no substituent, an alkyl group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, an alkoxy group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, an aryl group having 6 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, an aryloxy group having 6 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, and an acyl group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, Epoxy resin composition according to claim 1, wherein in formula (2), Y and Z are one selected from the group consisting of a hydrogen atom, a hydroxyl group, a carboxy group, an unsubstituted alkoxy group having 1 to 20 carbon atoms, an alkyl group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, an alkoxy group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, an aryl group having 6 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, an aryloxy group having 6 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent, and an acyl group having 1 to 20 carbon atoms and having a hydroxyl group and / or a carboxy group as a substituent.

7. In the component (B), the compound represented by the formula (1) is any one selected from the group consisting of 2-(2-hydroxyphenyl)imidazole, 2-(2-hydroxyphenyl)-4(5)-methylimidazole, 4-ethyl-(2-hydroxyphenyl)-5-methylimidazole, (2-hydroxyphenyl)-4-isopropyl-5-methylimidazole, 4-butyl-(2-hydroxyphenyl)-5-methylimidazole, and 2-(2-hydroxy-3(5)-methoxyphenyl)imidazole, and / or the compound represented by the formula (2) is any one selected from the group consisting of 2-(2-hydroxyphenyl)imidazole, 2-(2-hydroxyphenyl)-4(5)-methylimidazole, 4-ethyl-(2-hydroxyphenyl)-5-methylimidazole, 4-butyl-(2-hydroxyphenyl)-5-methylimidazole, and 2-(2-hydroxy-3(5)-methoxyphenyl)imidazole. The epoxy resin composition according to claim 1, which is any one selected from the group consisting of 2-(2-hydroxyphenyl)benzimidazole, 2-(2-hydroxy-3(5)-methoxyphenyl)benzimidazole, 2-(1-hydroxynaphthalen-2-yl)benzimidazole, 2-(2-hydroxynaphthalen-1-yl)benzimidazole, and 2-(2-hydroxyphenyl)benzimidazole-6-carboxylic acid.

8. The epoxy resin composition according to claim 1, further comprising component (C): a filler.

9. The epoxy resin composition according to claim 1, further comprising a component (E): a thermoplastic resin.

10. The epoxy resin composition according to claim 1, further comprising a silane coupling agent as component (G).

11. The epoxy resin composition according to claim 10, wherein the component (G) is an aminosilane coupling agent.

12. The epoxy resin composition according to claim 1, further comprising: component (H): a non-epoxy-terminated compound having a polyalkylene oxide structure.

13. The epoxy resin composition according to claim 12, wherein the terminal of said component (H) is a hydroxyl group.

14. The epoxy resin composition according to claim 13, wherein the component (H) is a compound represented by the following formula (3): (In formula (3), R ３ , R ４ are each independently an alkyl group having 1 to 12 carbon atoms; R ３ , R ４ may be the same or different. p and q are each independently an integer of 1 or more. R ５ , R ６ are each independently one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 20 carbon atoms which may have a substituent, a cycloalkyl group having 6 to 20 carbon atoms which may have a substituent, and an aryl group having 6 to 20 carbon atoms which may have a substituent. ５ , R ６ may be the same or different.) 15. A resin paste comprising the epoxy resin composition according to any one of claims 1 to 14.

16. A resin film comprising: a support; and a resin layer on the support, the resin layer comprising the epoxy resin composition according to any one of claims 1 to 14.

17. The resin film according to claim 16, further comprising a protective layer.

18. A cured product obtained by curing the epoxy resin composition according to any one of claims 1 to 14.

19. A semiconductor device having a layer of the cured material according to claim 18.

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