Epoxy resin composition, resin paste, film-type adhesive, printed wiring board, semiconductor chip package, and electronic device

Abstract

To provide an epoxy resin composition which reduces warpage and exhibits high heat resistance and high strength while achieving both stability during storage and curability during heating.SOLUTION: The epoxy resin composition comprises (A) an epoxy resin, (B) at least one curing agent selected from the group consisting of a triazine skeleton-containing phenol-based curing agent, an active ester-based curing agent and a cyanate ester-based curing agent and (C) a compound represented by a prescribed chemical formula, preferably an imidazole-based compound.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an epoxy resin composition, a resin paste, a film-type adhesive, a printed wiring board, a semiconductor chip package, and an electronic device. [Background technology]

[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 adhesives for semiconductor elements and printed wiring boards. The components of such epoxy resin compositions generally include an epoxy resin, a curing agent such as a phenolic resin that is 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, with the advancement of electronic devices in performance, build-up layers have been used and multi-layered in materials for electronic circuit boards such as printed wiring boards, and there has been a demand for finer and denser wiring, lower dielectric loss tangents to reduce transmission loss, and further, reduced warpage of the boards. In addition, in the packaging of semiconductor chips using the epoxy resin composition, wafer level packaging and panel level packaging have been attracting attention in order to achieve high productivity and low cost. In such packages, the epoxy resin composition is applied to a large substrate and cured, so there is a particular demand for low warpage. Furthermore, in common to all applications, the epoxy resin composition is required to have stability during storage and rapid curing ability when heated. Furthermore, as the density of electronic components increases and the amount of electronic information handled increases, the amount of heat generated by electronic devices increases, and therefore the epoxy resin composition is also required to have heat resistance.

[0005] Regarding epoxy resin compositions used as insulating resin materials for wafer-level packages and printed wiring boards, insulating resin materials containing a thermosetting resin, an inorganic filler, and a polymer resin having a glass transition temperature of 30°C or lower and having one or more skeletons selected from a butadiene skeleton, a carbonate skeleton, an acrylic skeleton, and a siloxane skeleton, and further having one or more skeletons selected from an amide skeleton, an imide skeleton, and a urethane skeleton, have been disclosed (see, for example, Patent Document 1). Such insulating resin materials are disclosed to have the effects of high dimensional stability and minimal warpage, since the content of the inorganic filler is 80 to 95 mass% relative to 100 mass% of the nonvolatile components of the insulating resin material, the average particle size of the inorganic filler is 5 μm or less, and the linear thermal expansion coefficient of the cured product of the insulating resin material is 3 to 30 ppm / °C at 25°C to 150°C. Furthermore, with regard to the stability and rapid curing of epoxy resin compositions, a curable composition containing a curing agent for anionic curable compounds, which is 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 2). It has been 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. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 7188486 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-29152 Summary of the Invention [Problem to be solved by the invention]

[0007] Conventionally, methods for reducing warpage of substrates have been used, such as introducing a flexible skeleton into the molecules of resin components such as epoxy resins and polymer resins, which account for the majority of epoxy resin compositions, to relieve the stress that causes warpage, or blending a high concentration of inorganic filler to bring the linear expansion coefficients of the substrate material and the epoxy resin composition closer together to suppress warpage. However, as disclosed in Patent Document 1, when an epoxy resin composition contains a certain amount of a polymer resin having a flexible skeleton with a low glass transition temperature, the glass transition temperature of the cured product decreases, resulting in a problem of insufficient heat resistance. Also, when an inorganic filler is contained in an epoxy resin composition at a high concentration, there are problems such as limited freedom of formulation and an increase in the viscosity of the epoxy resin composition, making it difficult to handle.

[0008] Furthermore, the epoxy resin composition disclosed in Patent Document 1 has a problem in that there is room for improvement in terms of both stability during storage and curability upon heating. On the other hand, although the epoxy resin composition disclosed in Patent Document 2 is shown to be able to achieve both stability during storage and curability in a high temperature range of around 150°C, it does not clearly state any composition that satisfies all of the physical properties, such as low warpage, heat resistance, and strength, required for applications such as printed wiring boards, wafer level packages, and panel level packages, and there is still room for further study.

[0009] In view of the above-mentioned problems of the prior art, the present invention aims to provide an epoxy resin composition which has both stability during storage and curability upon heating, reduces warpage, and also exhibits high heat resistance and high strength. [Means for solving the problem]

[0010] As a result of extensive research, the present inventors have discovered a method that is completely different from the conventional method of reducing warpage by adjusting the resin skeleton or the amount of inorganic filler added. This method involves adding an imidazole compound having a specific structure as a catalyst to a specific curing agent, thereby obtaining an epoxy resin composition that is stable during storage and curable upon heating, while also reducing warpage and exhibiting high heat resistance and high strength, and has thus completed the present invention. That is, the present invention is as follows.

[0011] [1] Component (A): epoxy resin, Component (B): at least one curing agent selected from the group consisting of a triazine skeleton-containing phenolic curing agent, an active ester curing agent, and a cyanate ester curing agent; Component (C): a compound represented by the following formula (1) and / or a compound represented by the following formula (2), An epoxy resin composition comprising:

[0012] [ka]

[0013] [ka]

[0014] In formulas (1) and (2), R1 and R2 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 optionally substituted alkyl group having 1 to 20 carbon atoms, and an optionally substituted cycloalkyl group having 6 to 20 carbon atoms. R1 and R2 may be the same or different, and R1 and R2 may be bonded to form a fused ring that does not have 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 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 monocyclic or condensed ring. m and n are integers of 1 to 4.

[0015] [2] The epoxy resin composition according to [1] above, further comprising component (D): a filler. [3] In the component (C), Y and Z are each 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 without a 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, The epoxy resin composition according to [1] or [2] above. [4] In the component (C), The compound represented by formula (1) 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) 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; The epoxy resin composition according to any one of [1] to [3] above. [5] The epoxy resin composition according to [4] above, further comprising component (D): a filler. [6] The epoxy resin composition according to any one of [1] to [5] above is included. Resin paste. [7] A support; a resin layer on the support, the resin layer including the epoxy resin composition according to any one of [1] to [5]; having Film type adhesive. [8] A support; a resin layer containing the epoxy resin composition according to any one of [1] to [5] on the support; and a protective layer on the resin layer; having Film type adhesive. [9] A layer having a cured product of the epoxy resin composition according to any one of [1] to [5] above. Printed wiring board.

[10] A layer having a cured product of the epoxy resin composition according to any one of [1] to [5] above. Semiconductor chip package.

[11] An electronic device having the printed wiring board according to [9].

[12] An electronic device having the semiconductor chip package described in

[10] . [Effects of the Invention]

[0016] According to the present invention, it is possible to provide an epoxy resin composition which has both stability during storage and curability upon heating, reduces warpage, and also exhibits high heat resistance and high strength. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention (hereinafter referred to as "the present embodiment") will be described in detail. The following embodiments are merely examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be implemented by modifying it as appropriate within the scope of its gist.

[0018] [Epoxy resin composition] The epoxy resin composition according to the present embodiment comprises: Component (A): epoxy resin, Component (B): at least one curing agent selected from the group consisting of a triazine skeleton-containing phenolic curing agent, an active ester curing agent, and a cyanate ester curing agent; Component (C): Contains a compound represented by the following formula (1) and / or a compound represented by the following formula (2).

[0019] [ka]

[0020] [ka]

[0021] In formulas (1) and (2), R1 and R2 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 optionally substituted alkyl group having 1 to 20 carbon atoms, and an optionally substituted cycloalkyl group having 6 to 20 carbon atoms. R1 and R2 may be the same or different, and R1 and R2 may be bonded to form a fused ring that does not have 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 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 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 and two or more Zs may be bonded to form a monocyclic or condensed ring. m and n are integers of 1 to 4.

[0022] (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)). Examples of the epoxy resin (A) include, but are not limited to, bifunctional epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol E type epoxy resins, bisphenol AD ​​type epoxy resins, bisphenol AF type epoxy resins, tetrabromobisphenol A type epoxy resins, biphenyl type epoxy resins, bixylenol type epoxy resins, tetrabromobiphenyl type epoxy resins, diphenyl ether type epoxy resins, 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, and N,N-diglycidylaniline type epoxy resins.

[0023] Further examples include trifunctional epoxy resins such as N,N-diglycidylaminobenzene type epoxy resin, o-(N,N-diglycidylamino)toluene type epoxy resin, and triazine type epoxy resin.

[0024] Further examples include tetrafunctional epoxy resins such as naphthalene-type tetrafunctional epoxy resins, tetraglycidyldiaminodiphenylmethane-type epoxy resins, and diaminobenzene-type epoxy resins.

[0025] Further examples include polyfunctional epoxy resins such as phenol novolac type epoxy resins, cresol novolac type epoxy resins, triphenylmethane type epoxy resins, tetraphenylethane type epoxy resins, dicyclopentadiene type epoxy resins, naphthol aralkyl type epoxy resins, and brominated phenol novolac type epoxy resins.

[0026] Further examples include diepoxy resins such as (poly)ethylene glycol diglycidyl ether, (poly)propylene glycol diglycidyl ether, butanediol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane diglycidyl ether, polytetramethylene ether glycol diglycidyl ether, glycerin diglycidyl ether, neopentyl glycol diglycidyl ether, cyclohexane diglycidyl ether, and dicyclopentadiene diglycidyl ether.

[0027] Further examples include triepoxy resins such as trimethylolpropane triglycidyl ether and glycerin triglycidyl ether.

[0028] Further examples include alicyclic epoxy resins such as vinyl(3,4-cyclohexene) dioxide and 2-(3,4-epoxycyclohexyl)-5,1-spiro-(3,4-epoxycyclohexyl)-m-dioxane.

[0029] Further examples include glycidylamine type epoxy resins such as tetraglycidylbis(aminomethyl)cyclohexane.

[0030] Further examples include hydantoin type epoxy resins such as 1,3-diglycidyl-5-methyl-5-ethylhydantoin; and epoxy resins having a silicone skeleton such as 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane.

[0031] Also, 2-ethylhexyl glycidyl ether, cyclohexanedimethanol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, ethylene glycol diglycidyl ether, hydrogenated bisphenol A type epoxy resin, silicone modified epoxy resin, (poly)ethylene glycol diglycidyl ether, (poly)propylene glycol diglycidyl ether, butanediol diglycidyl ether, trimethylolpropane diglycidyl ether, polytetrafluoroethylene diglycidyl ether, Tramethylene ether glycol diglycidyl ether, glycerin diglycidyl ether, neopentyl glycol diglycidyl ether, cyclohexane type diglycidyl ether, dicyclopentadiene type diglycidyl ether, trimethylolpropane triglycidyl ether, glycerin triglycidyl ether, vinyl(3,4-cyclohexene) dioxide, 2-(3,4-epoxycyclohexyl)-5,1-spiro-(3,4-epoxycyclohexyl)-m-dioxane, tetraglycidyl bis(aminomethyl) Glycidyl amine type epoxy resins such as 1,3-diglycidyl-5-methyl-5-ethylhydantoin type epoxy resins, 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane type epoxy resins, phenyl glycidyl ether, cresyl glycidyl ether, ps-butylphenyl glycidyl ether, styrene oxide, p-tert-butylphenyl glycidyl ether, o-phenylphenol glycidyl ether, p-phenylphenol glycidyl ether Examples of the epoxy resins include aliphatic epoxy resins and alicyclic epoxy resins that can also be used as reactive diluents, such as N-glycidyl phthalimide, n-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, α-pinene oxide, allyl glycidyl ether, 1-vinyl-3,4-epoxycyclohexane, 1,2-epoxy-4-(2-methyloxiranyl)-1-methylcyclohexane, 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane, and neodecanoic acid glycidyl ester.

[0032] The epoxy resin (A) may be solid or liquid at room temperature. By including an epoxy resin that is liquid at room temperature as the epoxy resin (A), the generated stress can be moderately alleviated, which tends to reduce warpage in the epoxy resin composition of the present embodiment, and also provides moderate tackiness, adhesion, and flexibility when made into a film-type adhesive, which is preferable. Such liquid epoxy resins are not limited to the following, but more preferred examples include liquid epoxy resins having a bisphenol A structure, a bisphenol F structure, a bisphenol AF structure, a naphthalene structure, a glycidyl ester structure, a glycidyl amine structure, a phenol novolac structure, a cyclohexane structure, a cyclohexanedimethanol structure, or a butadiene structure, and alicyclic liquid epoxy resins having an ester skeleton.

[0033] Specific examples of the liquid epoxy resin include: trade names EXA850CRP (BisA type epoxy resin), EXA830CRP (BisF type epoxy resin), HP4032, HP4032D, and HP4032SS (naphthalene type epoxy resin), manufactured by DIC Corporation; trade names jER828US, jER828EL, and jER825 (bisphenol A type epoxy resin), jER807, jER1750 (bisphenol F type epoxy resin), jER152 (phenol novolac type epoxy resin), jER630, and jER630LSD (glycidylamine type epoxy resin), manufactured by Mitsubishi Chemical Corporation; and trade names ZX1059 ( Examples of epoxy resins include mixtures of bisphenol A epoxy resin and bisphenol F epoxy resin, "ZX1658", "ZX1658GS" (liquid 1,4-glycidylcyclohexane epoxy resin), Nagase ChemteX Corporation trade name: EX-721 (glycidyl ester epoxy resin), Daicel Corporation trade name: CELLOXIDE 2021P (alicyclic epoxy resin with an ester skeleton), Epolead PB-3600 (epoxy resin with a butadiene structure), Nippon Soda Co., Ltd. trade name: JP-100, JP-200 (epoxy resin with a butadiene structure), and Asahi Kasei Corporation trade name: AER9000 (epoxy resin with a special flexible skeleton). These may be used alone or in combination of two or more.

[0034] Furthermore, the epoxy resin (A) preferably contains a solid epoxy resin, which can improve the heat resistance and strength of the cured product of the cured product layer of the epoxy resin composition of the present embodiment. More preferred examples of such epoxy resins include solid epoxy resins having a biphenyl structure, a bixylenol structure, a naphthalene structure, a cresol novolac structure, a dicyclopentadiene structure, a trisphenol structure, a naphthol structure, a naphthylene ether structure, an anthracene structure, a bisphenol A structure, a bisphenol AF structure, a tetraphenylethane structure, a bisphenolacetophenone structure, and a fluorene structure.

[0035] Specific examples of solid epoxy resins include those manufactured by DIC Corporation under the trade names of 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, EXA-7311-G3, EXA-7311-G4, and EXA-7311-G4S (naphthylene ether-type epoxy resins), and those manufactured by Nippon Kayaku Co., Ltd. under the trade names of EPPN-502H (trisphenol-type epoxy resin), NC3000, NC3000H, NC3000L, and NC3100 (biphenyl-type epoxy resins), and NC-7000L (naphthol novolac-type epoxy resin). Examples of epoxy resins include those manufactured by Tetsuo Sumikin Chemical Co., Ltd. under the trade names ESN475V and ESN485 (naphthol-type epoxy resins); those manufactured by Mitsubishi Chemical Corporation under the trade names YX4000, YX4000H, YX4000HS, and YL6121 (biphenyl-type epoxy resins), YX4000HK (bixylenol-type epoxy resins), YX8800 (anthracene-type epoxy resins), YX7700 (xylene structure-containing novolac-type epoxy resins), YL7760 (bisphenol AF-type epoxy resins), YL7800 (fluorene-type epoxy resins), jER1010 (bisphenol A-type solid epoxy resins), and jER1031S (tetraphenylethane-type epoxy resins); and those manufactured by Osaka Gas Chemicals Co., Ltd. under the trade names OGSOL PG-100 and CG-500 (fluorene-type epoxy resins). These may be used alone or in combination of two or more.

[0036] As the epoxy resin (A), it is preferable to use a liquid epoxy resin and a solid epoxy resin in combination, from the viewpoint of imparting the above-mentioned effects in a well-balanced manner. When a liquid epoxy resin and a solid epoxy resin are used in combination, the mass ratio thereof (liquid epoxy resin:solid epoxy resin) is not particularly limited, but is preferably in the range of 1:0.1 to 1:6. By setting the mass ratio of the liquid epoxy resin to the solid epoxy resin within the above range, the following effects can be obtained: (i) when used in the form of a film-type adhesive, the tackiness and adhesion are improved; (ii) when used in the form of a film-type adhesive, sufficient flexibility is obtained, improving handleability; and (iii) a cured product with sufficient breaking strength can be obtained, thereby improving the reliability of printed wiring boards, semiconductor chip packages, and electronic devices using them. From the viewpoint of the effects (i) to (iii) above, the mass ratio of the liquid epoxy resin to the solid epoxy resin (liquid epoxy resin:solid epoxy resin) is more preferably in the range of 1:0.3 to 1:5, and even more preferably in the range of 1:0.6 to 1:4.

[0037] The epoxy resin (A) has an epoxy equivalent of 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. When the epoxy equivalent is within the above range, the crosslink density of the cured product of the epoxy resin composition of the present embodiment is sufficient, and a cured product layer having excellent breaking strength tends to be obtained. The epoxy equivalent weight is the mass of the resin containing one equivalent of epoxy groups. The epoxy equivalent can be measured in accordance with JIS K7236.

[0038] 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 in the epoxy resin (A) is preferably 2500 ppm or less, more preferably 2000 ppm or less, even more preferably 1500 ppm or less, and still more preferably 900 ppm or less. Furthermore, from the viewpoint of suppressing excessive reduction, the total chlorine content contained in 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.

[0039] Here, the total amount of chlorine 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. Epoxy resin (A) is repeatedly washed with xylene and filtered until no epoxy resin remains in the xylene wash. The filtrate is then distilled under reduced pressure at 100°C or below 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 and dissolved in 25 mL of ethylene glycol monobutyl ether. 25 mL of 1N KOH propylene glycol solution is added, and the mixture is boiled for 20 minutes. The titer is then calculated from the titer obtained using a silver nitrate solution.

[0040] The content of the epoxy resin (A) in the epoxy resin composition of the present embodiment can be appropriately set depending on the desired performance and is not particularly limited. From the viewpoint of curability, however, it is preferably 5% by mass or more of all non-volatile components excluding solvents, more preferably 7.5% by mass or more, even more preferably 10% by mass or more, still more preferably 12% by mass or more, and still more preferably 14% by mass or more. Furthermore, from the viewpoint of ease of handling of the epoxy resin composition of the present embodiment and a film-type adhesive using the epoxy resin composition of the present embodiment, the content of the non-volatile components is preferably 80 mass % or less, more preferably 70 mass % or less, even more preferably 60 mass % or less, still more preferably 55 mass % or less, and even more preferably 50 mass % or less.

[0041] (Component (B): specific hardener) The epoxy resin composition of the present embodiment contains, as a specific curing agent, at least one curing agent selected from the group consisting of a triazine skeleton-containing phenolic curing agent, an active ester curing agent, and a cyanate ester curing agent (hereinafter, this may be referred to as curing agent (B) or component (B)).

[0042] A triazine skeleton-containing phenolic curing agent functions as a curing agent for epoxy resins and has both a triazine skeleton and a structure derived from a phenolic compound in one molecule. It is generally produced by condensing a phenolic compound with a compound having a triazine ring, such as melamine or benzoguanamine, and formaldehyde. The epoxy resin composition of the present embodiment contains a triazine skeleton-containing phenolic curing agent as component (B), and as a result, the linear expansion coefficient can be kept low due to the triazine skeleton, which tends to reduce warpage and improve heat resistance, strength, and adhesion to substrates. The nitrogen content in the triazine skeleton-containing phenolic curing agent is preferably 2% by mass or more, more preferably 4% by mass or more, even more preferably 5% by mass or more, still more preferably 6% by mass or more, and even more preferably 7% by mass or more, from the viewpoint of further improving the heat resistance, strength, and adhesion to a substrate of the epoxy resin composition of the present embodiment. On the other hand, from the viewpoint of maintaining the storage stability of the epoxy resin composition of the present embodiment and the crosslink density of the cured product within an appropriate range, the nitrogen content is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, even more preferably 25% by mass or less, and still more preferably 20% by mass or less. Furthermore, from the viewpoint of further increasing the crosslink density, the triazine skeleton-containing phenolic curing agent preferably contains a phenol novolac structure. Examples of the triazine skeleton-containing phenolic curing agent containing a phenol novolac structure include, but are not limited to, trade names of LA3018, LA3018-50P, LA7052, LA7054, and LA1356 manufactured by DIC Corporation.

[0043] The active ester curing agent functions as a curing agent for epoxy resins and has an active ester in the molecule. The epoxy resin composition of the present embodiment contains an active ester curing agent as component (B), and therefore does not generate hydroxyl groups, which are a factor in increasing the dielectric loss tangent, in the epoxy resin composition due to the reaction between the active ester and the epoxy group, and therefore tends to be able 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 per molecule is preferred. Furthermore, from the viewpoint of the heat resistance of the epoxy resin composition of this embodiment, an active ester compound obtained by reacting a carboxylic acid compound and / or a thiocarboxylic acid compound with a hydroxy compound and / or a thiol compound is more preferred, and an active ester compound obtained by reacting a carboxylic acid compound with one or more selected from a phenol compound, a naphthol compound, and a thiol compound is even more preferred. Furthermore, an aromatic compound having two or more active ester groups per molecule obtained by reacting a carboxylic acid compound with an aromatic compound having a phenolic hydroxyl group is even more preferred. Furthermore, an aromatic compound obtained by reacting a compound having at least two or more carboxylic acids per molecule with an aromatic compound having a phenolic hydroxyl group, and having two or more active ester groups per molecule of the aromatic compound, is even more preferred. The active ester curing agent may be linear or multi-branched. If the compound having at least two or more carboxylic acids in one molecule contains an aliphatic chain, it tends to have high compatibility with epoxy resins, and if it contains an aromatic ring, it tends to have high heat resistance.

[0044] Examples of the carboxylic acid compound used in preparing the active ester curing agent include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, etc. In particular, from the viewpoint of the heat resistance of the epoxy resin composition of the present embodiment, 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 used to prepare the active ester curing agent include, but are not limited to, thioacetic acid and thiobenzoic acid. Examples of the phenol compound or naphthol compound used in preparing the active ester curing agent include, but are not limited to, hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthaline, 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, dicyclopentadienyl diphenol, and phenol novolak.Among these, from the viewpoints of the heat resistance of the epoxy resin composition of the present embodiment 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. Dihydroxybenzophenone, 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 still more preferred, with dicyclopentadienyl diphenol being particularly preferred. Examples of the thiol compound used to prepare the active ester curing agent include, but are not limited to, benzenedithiol and triazinedithiol.

[0045] The active ester compound used as the active ester curing agent may be the active ester compounds disclosed in JP-A-2004-277460 and JP-A-2013-40270, or may be commercially available. Examples of commercially available active ester compounds include those manufactured by DIC 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 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).

[0046] The cyanate ester curing agent functions as a curing agent for epoxy resins and has a cyanato group in the molecule. The epoxy resin composition of this embodiment contains a cyanate ester curing agent as component (B). By reacting with the epoxy group, an oxazoline ring or an oxazolidinone ring is generated, imparting flexibility to the epoxy resin composition. Furthermore, the trimerization of the cyanato group results in the formation of a triazine skeleton, which tends to reduce warpage and improve heat resistance in particular. Furthermore, since hydroxyl groups are less likely to be generated during the reaction, the dielectric loss tangent tends to be kept low.

[0047] 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-cyanate phenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanate phenyl-1-(methylethylidene))benzene, bis(4-cyanate phenyl)thioether, and bis(4-cyanate phenyl)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. An example of a commercially available cyanate ester resin is CYTESTER (registered trademark) TA (bisphenol A-type cyanate ester resin) manufactured by Mitsubishi Gas Chemical Company, Inc.

[0048] The above-mentioned triazine skeleton-containing phenolic curing agent, active ester curing agent, and cyanate ester curing agent may be used alone, but from the viewpoint of ensuring adhesion and bonding properties while keeping the dielectric tangent and warpage of the epoxy resin composition of the present embodiment small, it is preferable to use a combination of two or more of them, and it is more preferable to combine an active ester curing agent with a triazine skeleton-containing phenolic curing agent, or a cyanate ester curing agent with a triazine skeleton-containing phenolic curing agent.

[0049] As described above, the mass ratio of the curing agents when two types of component (B) are combined is not particularly limited, and a person skilled in the art would be able to set it appropriately depending on the desired physical properties. For example, when an active ester curing agent and a triazine skeleton-containing phenolic curing agent are combined, from the viewpoint of achieving good adhesion and bondability while keeping the dielectric tangent and warpage of the epoxy resin composition of this embodiment small, the mass ratio of the active ester curing agent to the triazine skeleton-containing phenolic curing agent, in terms of the mass ratio of the non-volatile components excluding the solvent, is preferably 1:0.05 to 1:1.5, more preferably 1:0.05 to 1:1, even more preferably 1:0.07 to 1:0.8, and even more preferably 1:0.1 to 1:0.6. Furthermore, for example, when a cyanate ester curing agent and a triazine skeleton-containing phenolic curing agent are combined, from the same viewpoint as above, the mass ratio of the cyanate ester curing agent to the non-volatile components excluding the solvent is preferably 1:0.05 to 1:2.0, more preferably 1:0.1 to 1:1.5, even more preferably 1:0.2 to 1:1.2, and even more preferably 1:0.3 to 1:1, where the cyanate ester curing agent is 1.

[0050] The content of component (B) in the epoxy resin composition of the present embodiment can be appropriately set depending on the desired performance and is not particularly limited. However, if the number of epoxy groups in the epoxy resin (A) is taken as 1, from the viewpoint of setting the crosslink density between components (A) and (B) in an appropriate range and preventing remaining unreacted functional groups, the number of reactive groups in component (B) is preferably 0.1 to 3, more preferably 0.15 to 2.5, even more preferably 0.2 to 2, still more preferably 0.3 to 1.8, even more preferably 0.35 to 1.5, and particularly preferably 0.5 to 1.2. Here, the "number of epoxy groups" refers to the total value for all epoxy resins obtained by dividing the mass of each epoxy resin present in the epoxy resin composition by the epoxy equivalent. Furthermore, the "reactive group" refers to a functional group capable of reacting with an epoxy group, and is the total value obtained by dividing the mass of the nonvolatile components of each of the triazine skeleton-containing phenolic curing agent, active ester curing agent, and cyanate ester curing agent present in the epoxy resin composition by the reactive group equivalent.

[0051] (Component (C): Compound represented by the following formula (1) or (2)) The epoxy resin composition of the present embodiment contains a compound represented by the following formula (1) and / or a compound represented by the following formula (2) (hereinafter, may be referred to as compound (C) or component (C)).

[0052] [ka]

[0053] [ka]

[0054] In formulas (1) and (2), R1 and R2 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 optionally substituted alkyl group having 1 to 20 carbon atoms, and an optionally substituted cycloalkyl group having 6 to 20 carbon atoms. R1 and R2 may be the same or different, and R1 and R2 may be bonded to form a fused ring that does not have 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 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 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 and two or more Zs may be bonded to form a monocyclic or condensed ring. m and n are integers of 1 to 4.

[0055] As described above, R1 and R2 in the above general formula (1) are each 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 a structure in which R1 and R2 are on the same fused ring which does not have aromaticity, and R1 and R2 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. Examples of the alkyl group having 1 to 20 carbon atoms 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, and more preferably 6 to 15. Examples of the cycloalkyl group having 6 to 20 carbon atoms include a cyclohexyl group, a cycloheptane group, and a cyclooctane group. Specific examples of the structure in which R1 and R2 are on the same condensed ring without aromaticity include cyclopentane, cyclohexane, and dicyclopentadiene. Furthermore, the alkyl group, cycloalkyl group, and structure in which R1 and R2 are on the same fused ring that does not have aromaticity may have a substituent, and examples of the substituent include a halogen atom, a hydroxyl group, an alkoxy group, and a nitro group, and preferably a hydroxyl group or an alkoxy group.

[0056] 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.

[0057] 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. Examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, an isopropyl group, a butyl group, an isobutyl group, a hexyl group, and an octyl group.

[0058] 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. Examples of the alkenyl group having 2 to 20 carbon atoms 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.

[0059] 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, and more preferably 7 to 15. Examples of the aralkyl group having 7 to 20 carbon atoms include a benzyl group, a phenethyl group, and a naphthylmethyl group.

[0060] 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. Examples of the heteroarylalkyl group having 4 to 20 carbon atoms 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.

[0061] The alkyl group, alkenyl group, aralkyl group, or heteroarylalkyl group may each have a substituent. Examples of the substituent 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.

[0062] In the general formulas (1) and (2), Y and Z each represent 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, or a structure in which two or more Ys and two or more Zs are bonded to form a monocycle or a condensed ring, and m and n are integers of 1 to 4.

[0063] 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. Examples of the alkyl group having 1 to 20 carbon atoms 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.

[0064] 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. Examples of the alkoxy group having 1 to 20 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a hexyloxy group, and a 2-ethylhexyloxy group.

[0065] 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. Examples of the alkenyl group having 2 to 20 carbon atoms 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.

[0066] 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. Examples of the aryl group having 6 to 20 carbon atoms include a phenyl group, a naphthyl group, an anthracenyl group, and a biphenyl group.

[0067] Examples of structures in which two or more Ys or two or more Zs are bonded to form a single ring or a condensed ring include naphthyl and anthracenyl groups.

[0068] 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. Examples of the acyl group having 1 to 20 carbon atoms include an acetyl group, a benzoyl group, and a pivaloyl group.

[0069] 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.

[0070] Y may be substituted at any of the ortho, meta, or para positions of the phenyl group that 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 that may have a substituent.

[0071] Among the above, Y and Z in general formulas (1) and (2) are more preferably any 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 can be further reduced. 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 ability to form a coordinate bond with an adherend such as a metal is increased, which tends to improve adhesion and adhesive strength.

[0072] The compound represented by the general formula (1) includes, but is not limited to, the following imidazole compounds. For example, 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.

[0073] Also, 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, 4,5- Examples include 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.

[0074] Further, 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 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.

[0075] Further, 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 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.

[0076] Furthermore, 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, phenyl)-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.

[0077] Also, 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.

[0078] Further, 4,5-diphenyl-2-(3-ethoxy-2-hydroxyphenyl)imidazole, 2-(5-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.

[0079] Further, 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, Examples include imidazole, 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, and 2-(5-fluoro-2-hydroxyphenyl)-4(5)-ethylimidazole.

[0080] Furthermore, 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 2-(5-bromo-2-hydroxyphenyl)-4,5-diphenylimidazole, 2-(5-chloro-2-hydroxyphenyl)imidazole, 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, 2-(6-fluoro-2-hydroxy-3-methoxyphenyl)imidazole.

[0081] Also, 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)-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.

[0082] The compound represented by the general formula (2) includes, but is not limited to, 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.

[0083] Among these, from the viewpoints of obtaining a uniform epoxy resin composition by virtue of excellent solubility in the epoxy resin (A) and solvents, and achieving both reduced warpage and high heat resistance in the cured product, it is preferable that R1 and R2 are both hydrogen atoms or have different substituents in the compound represented by the general formula (1). 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.

[0084] The epoxy resin composition of this embodiment contains component (C): a compound represented by general formula (1) or (2) as a catalyst, and as a result, surprisingly, can reduce warpage of the cured product and also impart high heat resistance. Such effects cannot be easily predicted from the structure of component (C). Furthermore, the inventors tested the effects of imidazole compounds with various structures in the process of arriving at the present invention, but found no other compounds that could reduce warpage of the cured product and also impart high heat resistance other than those containing component (C) of the present invention as a catalyst, which is an extremely unique effect. Furthermore, component (C) is a component that catalytically reacts with component (A): the epoxy resin, and can exert the above-mentioned effects simply by adding it to the epoxy resin composition. Therefore, unlike conventional methods for reducing warpage, the warpage reduction effect can be achieved without blending an epoxy resin or polymer with a flexible skeleton or blending a high concentration of filler, thereby providing the effect of greatly increasing the degree of freedom of blending for those skilled in the art.

[0085] In the epoxy resin composition of the present embodiment, the addition of the compound of component (C) to the specific curing agent (component (B)) not only achieves both stability and curability, but also reduces warpage of the cured product and enables it to exhibit high heat resistance. The mechanism by which this occurs is thought to be as follows, although it is not intended to be limited to the following. Component (C) has a structural feature in which a hydroxyphenyl group is substituted at the 2-position of the imidazole structure that reacts with epoxy groups. As described in Patent Document 2, 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, which suppresses the nucleophilicity of the nitrogen on the imidazole during storage, thereby maintaining stability. However, when heated, the hydrogen bond dissociates, leading to a reaction. Next, various imidazole compounds were investigated to determine whether they reduced warpage and provided high heat resistance in the cured product. The results confirmed that component (C) used in the epoxy resin composition of this embodiment exhibited significant effects. Based on these findings, it is believed that component (C), due to its structural characteristics, functions as a chain transfer agent, in that the proximal hydroxyphenyl group donates a proton to stabilize the anion generated when the epoxy group reacts with the imidazole to open the ring. This suppresses the rapid generation of polymers concentrated around the reaction site and localized viscosity increase during the polymerization reaction, allowing the chain extension reaction to occur throughout the system. Therefore, the gradual and uniform viscosity increase during curing facilitates the relaxation of stress generated during curing, reducing warpage in the cured product. Furthermore, the lack of residual unreacted epoxy groups likely contributes to the high crosslink density and high heat resistance.

[0086] Furthermore, when the above-mentioned compound of component (C) is used as a catalyst for the above-mentioned specific curing agent (component (B)), the above-mentioned effect can be further enhanced. For example, triazine skeleton-containing phenolic curing agents and cyanate ester curing agents tend to have poor storage stability due to the presence of amine groups and cyanato groups that react with epoxy groups due to their structure, even in the absence of a catalyst, and the degree of deterioration becomes even more pronounced when a catalyst is added. Furthermore, active ester curing agents have low reactivity with epoxy groups as they are, so it is important to add a catalyst and cure at a high temperature of 180°C or higher to develop physical properties. However, with general catalysts, the self-polymerization reaction of epoxy groups occurs competitively at the curing temperature before the active esters have fully reacted, so unreacted active ester groups are likely to remain. On the other hand, due to its structure, the aforementioned component (C) significantly improves storage stability, even when using triazine skeleton-containing phenolic curing agents or cyanate ester curing agents. Furthermore, even during reactions at high temperatures, such as above 150°C or 180°C, its function as a chain transfer agent suppresses rapid self-polymerization of the epoxy group alone, allowing the reaction between each curing agent (B) and the epoxy group to proceed efficiently. This reduces the likelihood of unreacted functional groups remaining, and tends to fully utilize the inherent heat resistance and strength of the composition. Furthermore, because component (C) uniformly catalyzes the reaction between curing agent (B) and the epoxy group, curing proceeds without localized stress concentration, further reducing the effect of warping of the cured product.

[0087] Based on the above mechanism, the effects of the present invention can be achieved by using a wide range of components (C) having the structural characteristics represented by general formula (1) and / or (2), including those with various functional group substitutions, in combination with curing agent (B).

[0088] Since component (C) has an aromatic ring and a hydroxyl group, it has excellent compatibility with resins having an aromatic ring and polar solvents, and can be well dissolved in various epoxy resins and solvents. Generally, solid-dispersion imidazole compounds with reduced compatibility with epoxy resins are known as highly stable imidazole compounds, but these imidazole compounds have concerns about reduced uniformity in curing due to their solid nature, and also have problems such as reduced film-forming properties due to residual particles, particularly when a process of thinning the film by blending a solvent is performed, as in film-type adhesives, inability to apply to ultra-thin films, and the inability to achieve stability even in solid-dispersion forms due to dissolution in some solvents. Therefore, a compound like component (C) used in the epoxy resin composition of this embodiment, which can dissolve uniformly in resins and solvents while maintaining both stability and reactivity, is particularly suitable for applications that use solvents, such as film-type adhesives.

[0089] In the epoxy resin composition of the present embodiment, the mass ratio of the above-mentioned components (B) and (C) is not particularly limited, but in terms of the mass ratio of non-volatile components excluding the solvent, where component (B) is taken as 100, (component (B):component (C)) is preferably 100:0.1 to 100:40, more preferably 100:0.5 to 100:30, even more preferably 100:1 to 100:20, even more preferably 100:1.5 to 100:15, even more preferably 100:1.8 to 100:12, and particularly preferably 100:2 to 100:10. By ensuring this range, it is possible to obtain a sufficient reaction-accelerating effect of component (C) on component (B) while preventing unnecessary self-polymerization reaction of the epoxy resin caused by component (C). This also results in an appropriate crosslink density of the resulting cured product, which tends to result in a cured product layer with better heat resistance and strength.

[0090] The content of component (C) in the entire epoxy resin composition of this embodiment is not particularly limited. However, from the viewpoint of obtaining sufficient curability, it is preferably 0.005% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, even more preferably 0.15% by mass or more, and even more preferably 0.2% 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 product layer, it is preferably 10% by mass or less, more preferably 5% by mass or less, even more preferably 4% by mass or less, even more preferably 3% by mass or less, and even more preferably 2% by mass or less. However, because component (C) 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.

[0091] (Component (D): Filler) The epoxy resin composition of the present embodiment may further contain a filler (hereinafter, may be referred to as filler (D) or component (D)). The filler (D) is not particularly limited, but may be one or more selected from the group consisting of inorganic fillers (inorganic bulking agents) from the viewpoint of reducing warpage, inorganic fillers pre-treated with a silane coupling agent (H) described below, and organic fillers from the viewpoint of improving adhesive strength and crack resistance. These may be used alone or in combination of two or more. The shape of the filler (D) is not particularly limited, and may be, for example, any of irregular, spherical, and scaly shapes. From the viewpoint of bringing the linear expansion coefficients of the epoxy resin composition of the present embodiment closer to those of the substrate to be adhered and reducing warpage, it is preferable that the epoxy resin composition contain an inorganic filler.

[0092] Examples of inorganic fillers include, but are not limited to, ceramics such as 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 in which a polymer core material is coated with a metal thin film. Among these, it is preferable to contain silica 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 it is more preferable that the shape of the silica is spherical from the viewpoint of improving the filling property and the handleability of the epoxy resin composition. Examples of commercially available spherical fused silica include those manufactured by Admatechs Co., Ltd. under the trade names SO-C2, SO-C1, SO-E2, and SO-E1.

[0093] The average particle size of the filler (D) is not particularly limited, but from the viewpoint of forming a cured material layer using an epoxy resin composition containing the component (D) and being able to form fine wiring on the cured material layer, the average particle size is preferably 3 μm or less, more preferably 2 μm or less, and even more preferably 1 μm or less, 0.7 μm or less, 0.5 μm or less, 0.4 μm or less, or 0.3 μm or less. On the other hand, from the viewpoint of obtaining a resin paste with an appropriate viscosity and easy handling when the epoxy resin composition is used to form a resin paste, the average particle size of the filler (component (D)) is preferably 0.01 μm or more, more preferably 0.03 μm or more, even more preferably 0.05 μm or more, 0.07 μm or more, or even more preferably 0.1 μm or more. The average particle size of the filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, a particle size distribution of the filler is created on a volume basis using a laser diffraction particle size analyzer, and the median diameter is used as the average particle size. Examples of laser diffraction particle size analyzers that can be used include those manufactured by Sympatec under the trade name HELOS.

[0094] When an inorganic filler is used as the filler (D), 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, but is preferably 5 to 98 mass %, more preferably 10 to 95 mass %, even more preferably 15 to 90 mass %, still 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 solvents. By setting the content within these ranges, the epoxy resin composition and film-type adhesive of this embodiment can further exhibit the effects (i) to (iii), such as (i) maintaining an appropriate viscosity and providing excellent handleability, (ii) having the resin component and inorganic filler in just the right range and providing excellent adhesiveness, adhesion, and dimensional stability, and (iii) providing excellent warpage, heat resistance, and breaking strength when the resin composition is cured.

[0095] 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.

[0096] Examples of the organic filler include, but are not limited to, 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 organic fine particles of copolymers containing these as components, but are not particularly limited to these. From the viewpoint of improving adhesiveness, preferred examples of the organic fine particles include alkyl (meth)acrylate-butadiene-styrene copolymers, alkyl (meth)acrylate-silicone copolymers, silicone-(meth)acrylic copolymers, complexes of silicone and (meth)acrylic acid, complexes of alkyl (meth)acrylate-butadiene-styrene and silicone, and complexes of alkyl (meth)acrylate and silicone.

[0097] As the organic filler, organic fine particles having a core-shell structure, in which the composition of the core layer and the composition of the shell layer are different, can also be used. Examples of core-shell type organic fine particles include particles having a silicone-acrylic rubber core to which an acrylic resin is grafted, and particles having an acrylic resin grafted to an acrylic copolymer, but are not particularly limited to these. The lower 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 relaxation agent and tend to inhibit the progression of the fillet cracks. The core layer is preferably made of a material having excellent flexibility, such as, but not limited to, a silicone elastomer, a butadiene elastomer, a styrene elastomer, an acrylic elastomer, a polyolefin elastomer, and a silicone / acrylic composite elastomer. On the other hand, the material constituting the shell layer is preferably a material that has excellent affinity with other components of the semiconductor resin encapsulant, particularly with epoxy resin. Examples of the material constituting the shell layer include, but are not limited to, acrylic resin and epoxy resin. Among these, acrylic resin is particularly preferred from the viewpoint of affinity with other components of the semiconductor resin encapsulant, particularly with epoxy resin.

[0098] When an organic filler is used as the filler (D), 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% by 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.

[0099] (Component (E): Solvent) The epoxy resin composition of the present embodiment may further contain a solvent (hereinafter, may be referred to as solvent (E) or component (E)). The inclusion of the solvent (E) tends to facilitate uniform dissolution of the compound of component (C) in the epoxy resin composition, which can improve the curing uniformity of the cured layer made from the epoxy resin composition of this embodiment. Furthermore, by using the solvent (E) and selecting component (C) having a variety of structures according to the desired reaction temperature range and reaction rate, performance such as reduced warpage and high heat resistance tends to be further enhanced.

[0100] The solvent (E) is not particularly limited, and any known solvent can be used. Examples of the solvent (E) 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.

[0101] The content of the solvent (E) in the epoxy resin composition of the present 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 of the solvent (E) is preferably 5 to 80 mass % relative to the total epoxy resin composition, 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 %. In addition, when other components contain a solvent, such as when component (B) contains a solvent, the above content is a preferred range of the solvent ratio in the entire epoxy resin composition, including those solvents.

[0102] Furthermore, when the epoxy resin composition of this embodiment is used as a film-type adhesive, the content of the solvent (E) 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 film-type adhesive due to excessive solvent reduction, 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.

[0103] (Component (F): Other hardeners) The epoxy resin composition of the present embodiment may further contain the above-mentioned component (B): a predetermined curing agent (B) and component (C): a curing agent other than the compounds of general formulas (1) and (2) (hereinafter, may be referred to as curing agent (F) or component (F)). Component (F) can be a wide variety of conventionally known curing agents used in epoxy resins, and is not particularly limited. Examples include, but are not limited to, amine-based curing agents, amide-based curing agents, phenol-based curing agents (excluding triazine skeleton-containing phenol-based curing agents), acid anhydride-based curing agents, imidazole-based curing agents (excluding component (C)), carbodiimide-based curing agents, benzoxazine-based curing agents, phosphorus-based curing agents, thiol-based curing agents, catalyst-type curing agents, and modified products thereof. These may be used alone or in combination of two or more.

[0104] Examples of amine-based curing agents include, but are not limited to, aliphatic amines, aromatic amines, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene. 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, and 1,2-diaminocyclohexane. Examples of aromatic amines include, but are not limited to, diaminodiphenylmethane, m-phenylenediamine, diaminodiphenylsulfone, diethyltoluenediamine, trimethylenebis(4-aminobenzoate), polytetramethylene oxide-di-p-aminobenzoate, Nippon Kayaku Co., Ltd. (trade name: KAYAHARD AA), and Mitsui Chemicals Fine Co., Ltd. (trade name: Ethacure 100).

[0105] 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.

[0106] 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.

[0107] 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; Examples of suitable methyl guanidine include ethyl guanidine, diacetyl guanidine, propionyl guanidine, dipropionyl guanidine, cyanoacetyl guanidine, guanidine succinate, diethylcyanoacetyl guanidine, 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, and 1-(o-tolyl)biguanide.

[0108] Examples of phenolic curing agents (excluding triazine skeleton-containing phenolic curing agents) include, but are not limited to, phenol novolac resin, bisphenol A novolac resin, cresol novolac resin, phenol aralkyl resin, cresol aralkyl resin, naphthol-phenol co-condensed novolac resin, naphthol-cresol co-condensed novolac resin, allyl acrylic phenol resin, dicyclopentadiene skeleton-containing phenolic resin, biphenyl skeleton-containing phenolic resin, and naphthalene skeleton-containing phenolic resin. Examples of commercially available phenolic curing agents include those manufactured by DIC Corporation under the trade names TD2090 (phenol novolac resin) and EXB-9500 (naphthalene skeleton-containing phenolic resin), those manufactured by UBE Corporation under the trade names HF-1M (phenol novolac resin), MEH-7700, MEH-7810, and MEH-7851 (biphenyl skeleton-containing phenolic resin), those manufactured by Nippon Kayaku Co., Ltd. under the trade names NHN, CBN, and GPH (naphthalene skeleton-containing phenolic resin), and those manufactured by Nippon Steel Chemical & Material Co., Ltd. under the trade names SN170, SN180, SN190, SN475, SN485, SN495, SN375, and SN395 (naphthalene skeleton-containing phenolic resin). Among these, from the viewpoint of improving the heat resistance and strength of the cured product, it is preferable to use a phenolic curing agent having a bisphenol A type structure, a bisphenol F type structure, a bisphenol AF type structure, a naphthalene structure, a phenol novolac structure, a cyclohexane structure, a cyclohexanedimethanol structure, a butadiene structure, a biphenyl type 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, or a fluorene structure.

[0109] 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.

[0110] Examples of the imidazole curing agent other than the component (C) include, but are not limited to, 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 Examples include 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, and 2-phenylimidazoline.

[0111] Examples of carbodiimide curing agents include, but are not limited to, trade names of Carbodilite V-02B, V-03, V-04K, V-07, and V-09 manufactured by Nisshinbo Chemical Inc., and trade names of Stavaxol P, P400, and Hi-Kasil 510 manufactured by Rhein Chemie AG. Modified carbodiimide compounds such as those disclosed in Japanese Patent No. 7226954 may also be used.

[0112] Examples of benzoxazine curing agents include, but are not limited to, HFB2006M (trade name) manufactured by Showa Polymer Co., Ltd., and Pd, Fa, ALP-d (trade name) manufactured by Shikoku Kasei Holdings Co., Ltd.

[0113] 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.

[0114] 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 copolymer 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-hexanedithiol, and 1,10-decanedithiol. From the viewpoint of the impact resistance of a cured product of the epoxy resin composition of this 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 this embodiment, pentaerythritol tetrakis(3-mercaptopropionate) and pentaerythritol tetrakis(3-mercaptobutyrate) are more preferred.

[0115] Examples of catalyst-type curing agents include, but are not limited to, cationic thermosetting catalysts, BF3-amine complexes, and the like.

[0116] Modified curing agents include, but are not limited to, polyamine compounds, amine-epoxy adducts, amine-urea adducts, imidazole-epoxy adducts, amine imide compounds, microencapsulated curing agents coated with these compounds, and curing agents adsorbed on porous materials. Specific examples include, but are not limited to, Novacure HX-3722, HX-3742, HX-3088, HX-3613, HXA3932HP, HXA9322HP, HXA9382HP, and HXA9192HP (manufactured by Asahi Kasei Corporation), Amicure PN-23J, PN-40J, and MY-24 (manufactured by Ajinomoto Fine-Techno Co., Inc.), and Fujicure FXR-1020 and FXR-1030 (manufactured by Fuji Chemical Industry Co., Ltd.).

[0117] Among the above, component (F) preferably contains a carbodiimide-based curing agent, for example, from the viewpoint of improving adhesion between the epoxy resin composition of this embodiment and substrate materials, and from the viewpoint of increasing crosslink density by reacting with various active hydrogen groups to sufficiently develop strength of the cured product. Furthermore, component (F) preferably contains a benzoxazine-based curing agent, for example, from the viewpoint of obtaining a cured product excellent in dimensional stability, high flame retardancy, low dielectric loss tangent, and low water absorption.

[0118] The content of component (F) in the epoxy resin composition of this embodiment can be appropriately set depending on the reactivity of the above-mentioned components (B) and (C) and the desired performance, and is not particularly limited, but from the viewpoint of obtaining good reactivity, it is preferably 0.01 mass% or more, more preferably 0.1 mass% or more, and even more preferably 1.0 mass% or more of all non-volatile components excluding the solvent. Furthermore, from the viewpoint of obtaining good storage stability, it is preferably 40 mass% or less, more preferably 30 mass% or less, and even more preferably 20 mass% or less.

[0119] (Component (G): Thermoplastic resin) The epoxy resin composition of the present embodiment may further contain a thermoplastic resin (hereinafter, may be referred to as thermoplastic resin (G) or component (G)). By including the thermoplastic resin (G), 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, cracks and breaks can be prevented and the film shape can be maintained.

[0120] Examples of the thermoplastic resin (G) 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, polyethersulfone resin, polyphenylene ether resin, polysulfone resin, and acrylic resin. The thermoplastic resin (G) may be used alone or in combination of two or more.

[0121] From the viewpoint of obtaining a cured layer having sufficient strength using the epoxy resin composition of this embodiment, the weight average molecular weight of the thermoplastic resin (G) is preferably 10,000 or more, more preferably 15,000 or more, even more preferably 20,000 or more, even more preferably 25,000 or more, and even more preferably 30,000 or more. From the viewpoint of obtaining good compatibility, the upper limit of the weight average molecular weight of the thermoplastic resin (G) is preferably 200,000 or less, more preferably 180,000 or less, even more preferably 160,000 or less, and even more preferably 150,000 or less. The weight average molecular weight of the thermoplastic resin (G) 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 Tosoh HLC-8320GPC measuring device, a Shodex KF-804 / KF-803 / KF-802 / KF-802 column manufactured by Resonac, and tetrahydrofuran or the like as a mobile phase, and can be calculated using a calibration curve of standard polystyrene.

[0122] From the viewpoint of increasing the crosslink density of the cured product of the epoxy resin composition of this embodiment and ensuring sufficient heat resistance and strength of the cured product layer, the thermoplastic resin (G) 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.

[0123] Suitable thermoplastic resins (G) are 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 (G).

[0124] Suitable examples of the phenoxy resin include phenoxy resins 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, 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 phenoxy resins include 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).

[0125] Specific examples of polyvinyl acetal resins include Denka Butyral 4000-2, 5000-A, 6000-C, and 6000-EP, both manufactured by Denki Kagaku Kogyo Co., Ltd.; and S-LEC BH series, BX series, KS series (e.g., KS-1), BL series, and BM series, both manufactured by Sekisui Chemical Co., Ltd.

[0126] Examples of the acid anhydride group-containing vinyl resin include copolymers of an acid anhydride group-containing monomer (d1) and another monomer (d2). Examples of the acid anhydride group-containing monomer (d1) 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 examples include ethylenically unsaturated monomers such as (meth)acrylic acid, (meth)acrylic acid esters, and styrene. Specific examples of the acid anhydride group-containing vinyl resin include EF-30, EF-40, EF-60, and EF-80, both of which are product names of Cray Valley Corporation.

[0127] Specific examples of polyimide resins include Rikacoat SN-20 and PN-20 (trade names) manufactured by New Japan Chemical Co., Ltd., and Unidic V-8000 (trade name) 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 (Japanese Patent Laid-Open No. 2006-37083), and modified polyimides such as polysiloxane skeleton-containing polyimides (Japanese Patent Laid-Open No. 2002-12667, Japanese Patent Laid-Open No. 2000-319386, WO 2010 / 53186, etc.).

[0128] Specific examples of polyamide-imide resins include 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 Co., Ltd.

[0129] Examples of styrene-based elastomer resins 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 styrene-based elastomer resins include Asahi Kasei Corporation's Asaprene, Tufprene, and Asaflex products, and Kuraray Co., Ltd.'s Hybler and Septon products.

[0130] A specific example of the polyethersulfone resin is PES5003P, a product of Sumitomo Chemical Co., Ltd.

[0131] Specific examples of polysulfone resins include trade names of Polysulfone P1700 and P3500 manufactured by Solvay Advanced Polymers.

[0132] Specific examples of polybutadiene resins include 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 Chemical Industries, Ltd.

[0133] Specific examples of acrylic resins include Nagase ChemteX Corporation's product names: SG-P3, SG-600LB, SG-280, SG-790, SG-K2, and Negami Chemical Industrial Co., Ltd.'s product names: SN-50, AS-3000E, ME-2000, and the like.

[0134] In particular, from the viewpoints of ensuring sufficient heat resistance 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 (G) 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.

[0135] 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 (G) 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 (G) 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 its molecule is preferred, as this reduces the elasticity. 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 advantageously from the viewpoint of achieving the same reduced elasticity effect.

[0136] The content of thermoplastic resin (G) in the epoxy resin composition of this embodiment can be appropriately set depending on the content and types of epoxy resin (A), curing agent (B), and other curing agents used, the content of filler (D), and the desired performance of the epoxy resin composition of this embodiment, and is not particularly limited. From the viewpoint of ensuring the adhesion and flexibility of the epoxy resin composition of this embodiment, the content of thermoplastic resin (G) 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 solvent. From the viewpoint of maintaining good heat resistance and strength of the epoxy resin composition of this embodiment, the content 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.

[0137] (Component (H): 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 (H) or component (H)). The inclusion of the silane coupling agent (H) is preferred because it can improve the affinity between the resin component and the filler, or between the resin component and the substrate, improves the uniform dispersion of the filler component, and tends to improve the adhesiveness of the epoxy resin composition.

[0138] In the present embodiment, containing the silane coupling agent (H) means that in the step of obtaining the epoxy resin composition of the present embodiment, the silane coupling agent is incorporated into the composition of the epoxy resin composition by any one of the following methods (i) to (iii): Method (i): A method in which the filler (D) is treated with a silane coupling agent and the treated filler is blended into an epoxy resin composition. Method (ii): A method of adding a silane coupling agent directly to an epoxy resin composition (integral blend method) Method (iii): This method involves reacting a silane coupling agent with the resin terminal or side chain of the epoxy resin (A) or thermoplastic resin (G) used, or blending it as a silylated resin, such as using a resin in which a monomer and a silane coupling agent are copolymerized.

[0139] Any of the above-mentioned methods (i) to (iii) may be used, and method (i) is preferred from the viewpoint that alcohol, which is a by-product of the silane coupling reaction, is less likely to remain in the system and that the filler has better dispersibility. Methods (ii) and (iii) are preferred from the viewpoint that affinity can be exerted 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.

[0140] The silane coupling agent (H) has at least one hydrolyzable group such as an alkoxy group or an aryloxy group bonded to a silicon atom, and may further have an alkyl group, an alkenyl group, or an aryl group bonded thereto. The alkyl group may also be substituted with an amino group, an alkoxy group, an epoxy group, or a (meth)acryloyloxy group. The silane coupling agent (H) 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.

[0141] Specific examples of the silane coupling agent (H) 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; 3-glycidyloxypropyltrimethoxysilane; epoxysilane coupling agents such as propyltriethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyl(dimethoxy)methylsilane, glycidylbutyltrimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; mercaptosilane coupling agents such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, and 11-mercaptoundecyltrimethoxysilane; p-styryltrimethoxysilane coupling agents such as propyltriethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 3-glycidyloxypropyl(dimethoxy)methylsilane, glycidylbutyltrimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; Styrylsilane coupling agents such as methoxysilane, acrylate silane coupling agents such as 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, and 3-methacryloxypropyldiethoxysilane, isocyanate silane coupling agents such as 3-isocyanatepropyltrimethoxysilane, bis(triethoxysilylpropyl)disulfide, bis(triethoxysilylpropyl)tetramethylsilane, Sulfide silane coupling agents such as sulfides, 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,Organosilazanes such as 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-dipropyltetramethyldisilazane, hexamethylcyclotrisilazane, dimethylaminotrimethylsilazane, and tetramethyldisilazane Compounds, tetra-n-butyl titanate dimer, titanium-i-propoxyoctylene glycolate, tetra-n-butyl titanate, titanium octylene glycolate, diisopropoxytitanium bis(triethanolaminate), dihydroxytitanium bislactate, dihydroxybis(ammonium lactate)titanium, bis(dioctyl pyrophosphate)ethylene titanate, bis(dioctyl pyrophosphate)oxyacetate titanate ate, 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, isopropyl tricumyl phenyl titanate, isopropyl bis(dioctyl phosphite) titanate, Examples of titanate coupling agents include propyl 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.

[0142] Among these, aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, and organosilazane compounds are preferred, and aminosilane coupling agents are more preferred. Examples of commercially available products 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).

[0143] The content of the silane coupling agent (H) in the epoxy resin composition of the present embodiment is not particularly limited, but from the viewpoint of improving the dispersibility of the filler (D) and the adhesiveness and cohesion 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 (D).

[0144] (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, mold release agents, wetting agents, flame retardants, surfactants, stabilizers, and adhesion aids.

[0145] The diluent is not limited to, but includes, for example, dioctyl phthalate, dibutyl phthalate, benzyl alcohol, and the like.

[0146] 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, when added to the epoxy resin composition of the present embodiment, has the effect of lowering the viscosity of the epoxy resin composition. Examples of reactive diluents include, but are not limited to, acrylate compounds and epoxy compounds that can reduce viscosity without impairing reactivity.

[0147] 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.

[0148] Examples of epoxy compounds that are reactive diluents 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.

[0149] Although various monoepoxy compounds and glycidyl ether compounds of polyhydric alcohols can also be used as reactive diluents, these compounds have only one functional group (epoxy group, glycidyl group) per molecule that contributes to the reaction with components (B), (C), and (F), and although they do not volatilize and cause voids, they tend to be unable to form three-dimensional crosslinks upon curing, making it difficult to ensure sufficient heat resistance and toughness for the cured product of the epoxy resin composition. Therefore, from the viewpoint of being able to form three-dimensional crosslinks upon curing and suppressing a decrease in heat resistance and toughness 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.

[0150] The content of the reactive diluent can be appropriately set depending on the desired performance of the epoxy resin composition of this embodiment 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 suppress an increase in viscosity of the epoxy resin composition of this embodiment at room temperature and to suppress deterioration of embeddability when used as a film for embedding wiring. Furthermore, a decrease in heat resistance and toughness during curing tends to be suppressed, and the occurrence and progression of fillet cracks tends to be suppressed. 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 suppress a decrease in adhesion and to suppress peeling during a moisture absorption reflow test. It is also preferable to further contain a reactive diluent to suppress an increase in viscosity that occurs when the filler (D) is highly loaded.

[0151] Examples of pigments include, but are not limited to, kaolin, chalk powder, gypsum, antimony trioxide, pentone, aerosol, lithopone, baryte, and titanium dioxide.

[0152] 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.

[0153] Examples of flow control agents include, but are not limited to, organic titanium compounds such as titanium tetraisopropoxide and titanium diisopropoxybis(acetylacetonate); organic zirconium compounds such as zirconium tetra-normal-butoxide and zirconium tetraacetylacetonate; and the like.

[0154] 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.

[0155] Examples of reinforcing agents 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.

[0156] 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 ester having 16 to 22 carbon atoms.

[0157] Examples of wetting agents include, but are not limited to, unsaturated polyester copolymer wetting agents having acidic groups, such as acrylic polyphosphate esters.

[0158] Examples of the flame retardant 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. From the viewpoint of heat resistance, phosphazene compounds and magnesium hydroxide are preferred. The phosphazene compounds disclosed in Japanese Patent Publication No. 723041 can also be used. The flame retardants may be used alone or in combination of two or more. 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).

[0159] Examples of surfactants include, but are not limited to, anionic surfactants such as alkylbenzenesulfonates and alkylpolyoxyethylenesulfates, cationic surfactants such as alkyldimethylammonium salts, amphoteric surfactants such as alkyldimethylamine oxides and alkylcarboxybetaines, and nonionic surfactants such as linear alcohols and fatty acid esters having 25 or more carbon atoms.

[0160] 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 resins and uniformity of curing, 2,2'-oxybis(5,5'-dimethyl-1,3,2-oxaborinane) is preferred as the cyclic borate ester compound. The stabilizer may be used alone or in combination of two or more kinds.

[0161] 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.

[0162] The additives described above can be added in functionally appropriate 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. Those skilled in the art can determine appropriate amounts depending on the formulation and desired performance.

[0163] [Epoxy resin composition and resin paste using the same] The epoxy resin composition of the present embodiment and the resin paste using the same contain the above-mentioned components (A) to (C), and can be obtained by adding and mixing components (D) to (H) and the above-mentioned additives as needed. That is, the resin paste of the present embodiment contains the epoxy resin composition of the present embodiment. The mixing method is not particularly limited, and any method known to those skilled in the art can be applied, including, but not limited to, mixing using a mixing roll such as a three-roll mill, a dissolver, a planetary mixer, a rotary mixer, a kneader, an extruder, or the like, to thoroughly mix the mixture until it becomes homogeneous.

[0164] (Specific embodiments of the epoxy resin composition and the resin paste using the same) The epoxy resin composition of the present embodiment not only achieves both stability and reactivity, but also excels in low warpage, high heat resistance, and high strength, and therefore can be used as a sealing material for electric and electronic components such as a relay sealing material, paste materials such as various insulating liquid adhesives, die attach paste, conductive paste, and thermally conductive paste, ink materials such as solder resist ink and hole-filling ink, matrix resin for fiber-reinforced plastics, impregnation and fixing material for motor coils, and the like. In particular, a solvent is often added to paste materials and ink materials, and in the case of the epoxy resin composition of the present embodiment containing component (C), component (C) dissolves uniformly in the solvent, so no granular residue is generated 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 and is therefore more preferable. Low warpage, high heat resistance and high strength are common properties required for liquid adhesives, matrix resins for fiber-reinforced plastics and impregnating adhesives for motor coils, and the epoxy resin composition of the present embodiment satisfies these requirements and is suitable for all of these applications.

[0165] [Film-type adhesive] The epoxy resin composition of the present embodiment can be made into a film-type adhesive. The film-type adhesive of the present embodiment has, for example, a predetermined support and a resin layer containing the epoxy resin composition of the present embodiment described above, and may, if necessary, have a protective layer on the surface of the resin layer opposite the support.

[0166] (Support) The support constituting the film-type adhesive is preferably made of a material that can withstand the temperature during solvent drying. Examples of such supports include, but are not limited to, polyethylene terephthalate films, polyvinyl alcohol films, polyvinyl chloride films, vinyl chloride copolymer films, polyvinylidene chloride films, vinylidene chloride copolymer films, polymethyl methacrylate copolymer films, polystyrene films, polyacrylonitrile films, styrene copolymer films, polyamide films, and cellulose derivative films. These films may be stretched as required.

[0167] (protective layer) The protective layer is preferably made of a material that can sufficiently maintain the smoothness of the surface of the resin layer that constitutes the film-type adhesive. Such a protective layer is not limited to the following, but polyethylene film, polypropylene film, polyethylene terephthalate film treated for easy peeling, oriented polypropylene film, etc. can be preferably used.

[0168] (Manufacturing method of film-type adhesive) The film-type adhesive of this embodiment can be produced by sequentially laminating a support, a resin layer, and, if necessary, a protective layer. As a method for laminating the support, the resin layer, and the protective layer, a known method can be adopted. For example, the epoxy resin composition of this embodiment containing solvent (E) is prepared and then coated onto a 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 while suppressing deformation of the support due to excessive heating and excessive reaction of the resin layer during drying, drying is preferably performed at a temperature range of 50°C to 160°C for a drying time of 1 to 30 minutes, and more preferably at 80°C to 150°C for 3 to 25 minutes. The drying temperature may be constant or may be varied with a temperature gradient. Next, if necessary, a protective layer may be laminated on the formed resin layer to produce a film-type adhesive.

[0169] (Specific embodiment of film-type adhesive) The film-type adhesive of this embodiment can be used as, for example, but not limited to, an interlayer insulating film, a film-type solder resist, an encapsulating sheet for a semiconductor package, a die attach film, a conductive film, an anisotropic conductive film, a non-conductive film, a thermally conductive film, etc. Film-type adhesives using the epoxy resin composition of this embodiment not only exhibit the various stabilities required in the production of film-type adhesives, such as varnish storage stability until coating and drying, stability at drying temperatures, and film storage stability, but also exhibit low warpage, heat resistance, and strength in the cured layer, making them particularly effective for materials that are prone to warping, such as film-type adhesives, and that require high strength and reliability in the thin cured layer. Furthermore, because component (C) dissolves uniformly in the epoxy resin composition or solvent, the film-type adhesive of this embodiment has excellent surface smoothness and can be adhered to substrates without gaps. The above-mentioned properties are commonly required for interlayer insulating films, film-type solder resists, sealing sheets for semiconductor packages, die attach films, conductive films, anisotropically conductive films, non-conductive films, thermally conductive films, etc., and therefore the film-type adhesive of this embodiment is suitable for these applications.

[0170] [Printed wiring board] The printed wiring board of this embodiment has a cured layer of the epoxy resin composition of this embodiment. When a printed wiring board is manufactured using the film-type adhesive of this embodiment described above, the film-type adhesive manufactured by the above method is attached to a patterned inner layer circuit board and laminated while applying pressure and heat from the support side. The inner layer circuit surface may be pre-roughened. Lamination is performed under normal pressure or reduced pressure, either batchwise or continuously using a roll, but simultaneous lamination on both sides is preferred. The lamination conditions are preferably a pressure bonding temperature of 70°C to 150°C and a pressure bonding pressure of 0.1 to 1 MPa. Furthermore, to prevent the generation of voids, lamination is preferably performed under reduced pressure of 2 KPa or less. After lamination, the film is cooled to room temperature and the support film is peeled off, and the adhesive film laminated on the inner layer circuit board is then heat-cured to form a cured layer. Curing conditions are preferably a curing temperature of 130 to 200°C and a curing time of 30 to 120 minutes.

[0171] Next, via holes are drilled using a laser such as a carbon dioxide laser, and then roughened with an oxidizing agent such as permanganate, dichromate, or ozone to remove smears and improve adhesion with the plating. Subsequently, conductor circuits are selectively formed on the cured product layer using electroless plating or electrolytic plating, and simultaneously, conductors are formed on the inner walls of the via holes to form outer layer circuits. Annealing is then performed at 150-200°C for 30-60 minutes to improve adhesion between the conductor layer and the resin layer. The above manufacturing process can be repeated on the conductor circuit layer thus obtained using a film-type adhesive to form multiple build-up layers, resulting in a printed wiring board.

[0172] As described above, the cured product of the epoxy resin composition of the present embodiment has little warpage, high heat resistance, and high strength, and therefore can be widely used for printed wiring boards such as rigid substrates, flexible substrates, single-area laminate substrates, and thin substrates, and can be particularly suitably used as a build-up layer for multilayer printed wiring boards.

[0173] [Semiconductor chip package] The semiconductor chip package of this embodiment has a cured layer of the epoxy resin composition of this embodiment. By using the film-type adhesive of this embodiment, it is possible to produce a semiconductor chip package that has low warpage, excellent heat resistance, and excellent strength. It is particularly suitable for use in wafer-level packages and panel-level packages, where low warpage is important because large-area substrates are used. The film-type adhesive may be laminated on both sides or one side of the substrate used. Various methods for manufacturing packages have been devised, but they can be broadly divided into fan-in and fan-out structures.

[0174] When a fan-in structure semiconductor chip package is manufactured using the film-type adhesive manufactured as described above, for example, the film-type adhesive manufactured by the above method is laminated on a substrate such as a silicon wafer on which circuits, elements, and electrode pads are formed, and cured to obtain a cured layer. The lamination conditions and curing conditions in this case may be the same as those used when manufacturing a printed wiring board, or may be changed as appropriate depending on the heat resistance, etc., of the elements used. Next, the cured product layer is subjected to drilling, smear removal, electroless plating, and electrolytic plating to form a rewiring layer, thereby obtaining a circuit layer. Further, by repeating the lamination and circuit layer formation as necessary, a multilayer circuit can be formed. After that, solder balls are arranged so as to be electrically connected to the circuit layer, and the resulting product is diced into individual pieces, thereby producing the fan-in structure semiconductor chip package of the present invention. Alternatively, before laminating the film-type adhesive on the substrate, columnar electrodes may be formed on the electrode pads, and after the film-type adhesive is cured, the upper surface of the cured layer may be polished until the columnar electrode surfaces are exposed, thereby forming a circuit layer.

[0175] When a fan-out structure semiconductor chip package is manufactured using the film-type adhesive produced as described above, for example, a substrate such as a silicon wafer is diced into individual pieces, and each individual piece is rearranged and fixed on a support via a film such as a die attach film, and then the film-type adhesive of this embodiment is laminated from the individual piece side and cured to form a cured layer. The cured layer is then drilled, smeared, and electroless and electrolytically plated to form a rewiring layer, resulting in a circuit layer. Multilayer circuits can be formed by repeating the lamination and circuit layer formation as needed. Then, solder balls are placed so that they are electrically connected to the circuit layer, resulting in a fan-out structure semiconductor chip package. Note that circuits, elements, and electrode pads may be formed before dicing the substrate. In this case, after rearrangement to form a cured material layer, openings can be formed in the electrode pad areas by etching, and a circuit layer can be formed in the openings by plating. Then, a circuit pattern and electrodes can be formed on the cured material layer using a photoresist material, and solder balls can be arranged so as to be electrically connected to the circuit, thereby manufacturing a fan-out structure semiconductor chip package.

[0176] [Electronic equipment] The electronic device of this embodiment includes the printed wiring board and / or the semiconductor chip package of this embodiment described above. The printed wiring board and semiconductor chip package of the present embodiment have a cured material layer that exhibits low warpage, high heat resistance, and high strength. Therefore, even when mounted on electronic devices that are miniaturized, downsized, and highly dense, they can prevent poor connections and cracks due to warpage and can withstand heat generated due to the increased volume of electronic information handled. Therefore, the resulting electronic devices have excellent long-term reliability, which is preferable.

[0177] The electronic device is not particularly limited as long as it is a device that functions by incorporating electronic components, and examples include electrical appliances such as personal computers, smartphones, game consoles, digital cameras and televisions, vehicles such as motorcycles, automobiles, trains, ships and aircraft, and various electronic devices used in high-speed communication antennas, servers, etc.

[0178] The electronic device of this embodiment can be manufactured by mounting various semiconductor chips at the circuit connection locations on the printed wiring board to ensure electrical continuity.

[0179] The method for mounting the semiconductor chip when manufacturing the electronic device of this embodiment is not particularly limited, but specific examples include a wire bonding mounting method, a flip chip mounting method, a bumpless build-up layer (BBUL) mounting method, a mounting method using an anisotropic conductive film, and a mounting method using a non-conductive film. Furthermore, in mounting, the epoxy resin composition of this embodiment, and a resin paste or film-type adhesive using the same can be used to seal, adhere, or the like a semiconductor chip. [Example]

[0180] Hereinafter, the present embodiment will be described with reference to specific examples and comparative examples. However, the present invention is not limited to the following examples and comparative examples, and can be modified as appropriate within the scope of the invention. In the following, "parts" and "%" are by mass unless otherwise specified.

[0181] [Preparation of Epoxy Resin Composition] Each component was weighed out so as to obtain the blending parts shown in Tables 1 to 3 below, and mixed until sufficiently uniform, to obtain an epoxy resin composition. In the table, component (B) is listed in parts including the solvent when the product used contains a solvent, as described below.

[0182] [Methods for measuring and evaluating characteristics] (Evaluation of varnish storage stability: Measurement of varnish thickening ratio) The viscosity of the epoxy resin composition immediately after preparation (initial viscosity) and the viscosity of the epoxy resin composition after storage at 25°C for 2 weeks were measured at room temperature (25°C) using an E-type viscometer (TVE-35H, manufactured by Toki Sangyo Co., Ltd.), and the varnish thickening ratio was calculated using the following mathematical formula (1). Varnish thickening ratio (times) = viscosity after 2 weeks of storage at 25°C / initial viscosity Formula (1) The thickening ratio was evaluated as preferably 1.5 times or less, more preferably 1.2 times or less, even more preferably 1.1 times or less, and even more preferably 1.0 times. In addition, in Tables 1 to 3 below, the epoxy resin compositions that had increased in viscosity so significantly after storage that viscosity measurement was impossible were indicated as gelled.

[0183] (Curing evaluation: visual inspection) Using the prepared epoxy resin composition, an epoxy resin composition layer was coated on the center of an aluminum foil measuring 15 cm in length, 8 cm in width, and 1.7 mm in thickness, so as to have a length of 12 cm, a width of 5 cm, and a dry film thickness of 150 μm, and then the coated film was dried by heating in an oven preheated to 120°C for 5 minutes to obtain a film. The dried film was allowed to cool to room temperature, and then, with the four corners fixed with heat-resistant tape, it was cured in an oven at 150°C for Examples 1 to 6 and Comparative Examples 1 and 2 for 1 hour, or in an oven at 180°C for the other Examples and Comparative Examples for 1 hour, to obtain a cured layer. If the cured product layer after curing was free of tack on the surface and cross section and had a uniform cured product layer with no areas of different color tone, the curability was evaluated as good and marked with a circle.

[0184] (Warp evaluation: measurement of the amount of warp) Using the prepared epoxy resin composition, an epoxy resin composition layer was coated on the center of an aluminum foil measuring 15 cm in length, 8 cm in width, and 1.7 mm in thickness, so as to have a length of 12 cm, a width of 5 cm, and a dry film thickness of 150 μm, and then the coated film was dried by heating in an oven preheated to 120°C for 5 minutes to obtain a film. The dried film was allowed to cool to room temperature, and then, with the four corners fixed with heat-resistant tape, it was cured in an oven at 150°C for Examples 1 to 6 and Comparative Examples 1 and 2 for 1 hour, or in an oven at 180°C for the other Examples and Comparative Examples for 1 hour, to obtain a cured product. After curing, one end of the aluminum foil in the long side direction was fixed to a flat surface, and the height of the aluminum foil end on the opposite side lifted from the flat surface was measured and taken as the amount of warping. The warpage was evaluated according to the following criteria. <Evaluation criteria> Warpage ≦ 5mm ◎◎ 5mm<warping≦10mm...◎ 10mm<warping amount≦25mm.....OK 25mm<warping amount ×

[0185] (Evaluation of heat resistance: Measurement of film glass transition temperature) The epoxy resin composition was cured by the method described above (Evaluation of Warpage) to obtain a cured product, and then the aluminum foil was peeled off to remove the cured product layer. The removed cured layer was subjected to DMA measurement (RSA-G2, manufactured by TA Instruments, Inc.) at a temperature increase rate of 4°C / min from 25°C to 250°C, and the temperature at which tan δ took the maximum value was determined as the glass transition temperature. If the film glass transition temperature was 160°C or higher, it was determined that the film had good heat resistance.

[0186] (Strength evaluation: Measurement of film tensile strength) The epoxy resin composition was cured by the method described above (Evaluation of Warpage) to obtain a cured product, and then the aluminum foil was peeled off to remove the cured product layer. The removed cured layer was cut into a piece 5 mm wide and 4 cm long to obtain a test piece. The cut test pieces were subjected to a tensile test (AUTOGRAPH AGS-X 5kN, manufactured by Shimadzu Corporation) at a tension speed of 100 mm / min in a constant temperature and humidity chamber at 23°C and 50% RH, and the tensile strength was calculated from the breaking point.

[0187] [Ingredients] The components used in the epoxy resin compositions of the Examples and Comparative Examples are shown in Tables 1 to 3 below.

[0188] (Component (A): Epoxy resin) A-1: EXA850CRP (BisA liquid epoxy resin, epoxy equivalent 190g / eq, manufactured by DIC) A-2: EXA830CRP (BisF liquid epoxy resin, epoxy equivalent 160g / eq, manufactured by DIC) A-3: HP4032D (naphthalene-type liquid epoxy resin, epoxy equivalent 142g / eq, manufactured by DIC) A-4: NC-3000 (biphenyl-type solid epoxy resin, epoxy equivalent 275g / eq, manufactured by Nippon Kayaku Co., Ltd.) A-5: YX4000 (biphenyl-type solid epoxy resin, epoxy equivalent 186g / eq, manufactured by Mitsubishi Chemical Corporation) A-6: HP-4710 (naphthalene-type tetrafunctional solid epoxy resin, epoxy equivalent 170g / eq, manufactured by DIC Corporation)

[0189] (Component (B): specific hardener) B-1: HPC-8000-65T (active ester curing agent, toluene solution with 65% solids, active group equivalent weight 223g / eq, manufactured by DIC) B-2: LA-3018-50P (triazine skeleton-containing phenolic curing agent, 50% solids in 1-methoxy-2-propanol solution, OH equivalent 151g / eq, manufactured by DIC) B-3: CYTESTER (registered trademark) TA (bisphenol A type cyanate ester curing agent, active group equivalent weight 139 g / eq, manufactured by Mitsubishi Gas Chemical Company, Inc.)

[0190] (Component (C): Compounds represented by general formula (1) and general formula (2)) C-1: 2-(2-hydroxyphenyl)imidazole (Ambeed, Inc.) C-2: 2-(2-hydroxyphenyl)benzimidazole (Tokyo Chemical Industry Co., Ltd.) C-3: 2-(2-hydroxyphenyl-5-methoxyphenyl)benzimidazole (AOBChemUSA) C-4: 2-(2-hydroxyphenyl)benzimidazole-6-carboxylic acid (Apollo Scientific Ltd)

[0191] (Comparative compound not corresponding to component (C)) R-1: DMAP (4-dimethylaminopyridine, manufactured by Tokyo Chemical Industry Co., Ltd.) R-2: 1B2PZ (1-benzyl-2-phenylimidazole, manufactured by Shikoku Chemicals Holdings Co., Ltd.) R-3: 2P4MZ (2-phenyl-4-methylimidazole, manufactured by Shikoku Kasei Holdings Co., Ltd.) R-4: 2MZ-A (2,4-diamino-6-[2-(2-methyl-1-imidazolyl)ethyl]-1,3,5-triazine, manufactured by Shikoku Chemicals Holdings Co., Ltd.)

[0192] (Component (D): Filler) D-1: SO-E2 (spherical silica filler, average particle size 0.5 μm, manufactured by Admatechs Co., Ltd.)

[0193] (Component (E): Solvent) E-1: Methyl ethyl ketone (Fujifilm Wako Pure Chemical Industries, Ltd.) E-2: Cyclohexanone (Fujifilm Wako Pure Chemical Industries, Ltd.)

[0194] (Component (F): Other hardeners) F-1: HF-1M (phenol novolac resin curing agent, OH equivalent 106g / eq, manufactured by UBE)

[0195] (Component (G): Thermoplastic resin) G-1: PKHB (phenoxy resin, weight average molecular weight 32,000, manufactured by Gabriel Phenoxies)

[0196] (Component (H): Silane coupling agent) H-1: KBM-573 (aminosilane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0197] [Examples 1 to 22], [Comparative Examples 1 to 7] The components were blended in the proportions (parts by mass) shown in Tables 1 to 3, and epoxy resin compositions were prepared by the method described above. The properties of the prepared epoxy resin compositions were measured and evaluated by the above-mentioned methods.

[0198] [Table 1]

[0199] [Table 2]

[0200] [Table 3]

[0201] Comparing Examples 1 to 6, which used a triazine skeleton-containing phenolic curing agent as component (B), with Comparative Examples 1 and 2, it was found that the inclusion of component (C) resulted in excellent varnish storage stability, low warpage, and a glass transition temperature approximately 20 to 30° C. Furthermore, comparing Examples 1 and 2 with Comparative Example 1, and Examples 3 to 6 with Comparative Example 2, which used the same curing agent type and amount, it was found that the Examples exhibited higher tensile strength. Examples 7 to 15, which used only an active ester curing agent or a triazine skeleton-containing phenolic curing agent as component (B), had warpage that was approximately 20 mm smaller, glass transition temperatures that were approximately 10 to 30°C higher, and tensile strengths that were up to 28 MPa higher than Comparative Examples 3 to 5 with the same formulation, demonstrating superior warpage, heat resistance, and strength. Furthermore, the varnish storage stability was also excellent. Comparing Examples 16-22 and Comparative Examples 6 and 7, which used a cyanate ester curing agent and a triazine skeleton-containing phenolic curing agent or an active ester curing agent as component (B), it was found that all had glass transition temperatures of 160°C or higher, which was acceptable for practical use, but the varnish storage stability of Comparative Examples 6 and 7 was very poor and impractical. On the other hand, it was found that the use of component (C) dramatically improved the varnish storage stability. Furthermore, comparing Examples 16-20 and Comparative Example 6, and Examples 21 and 22 and Comparative Example 7, which have the same formulation, it was found that the Examples were superior in terms of warpage and film tensile strength. As described above, it was found that the examples containing component (C) in combination with a specific curing agent (B) were able to improve the varnish storage stability, warpage, glass transition temperature, and tensile strength, and thus exhibited exceptional effects.

[0202] This application is based on a Japanese patent application (Patent Application No. 2023-109093) filed with the Japan Patent Office on July 3, 2023, the contents of which are incorporated herein by reference. [Industrial Applicability]

[0203] The epoxy resin composition of the present embodiment not only achieves both stability and reactivity, but also excels in low warpage, high heat resistance, and high strength. Therefore, the composition has industrial applicability in the fields of 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 resin materials such as impregnating and fixing materials for motor coils, as well as 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. In particular, low warpage, high heat resistance, and high strength are even more required in multilayer printed wiring boards, coreless substrates, and large package substrates for high-speed servers and network servers, so the film-type adhesive, printed wiring boards, semiconductor chip packages, electronic devices, etc. of the present invention can be effectively used.

Claims

1. Component (A): an epoxy resin; Component (B): at least one curing agent selected from the group consisting of a triazine skeleton-containing phenolic curing agent, an active ester curing agent, and a cyanate ester curing agent; Component (C): a compound represented by the following formula (1) and / or a compound represented by the following formula (2), An epoxy resin composition comprising: 【Chemistry 1】 【Chemistry 2】 (In formulas (1) and (2), 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. 1 , R 2 may be the same or different, and R 1 , R 2 may be bonded to form a fused ring that does not have 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 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 monocyclic or condensed ring. m and n are integers of 1 to 4.

2. Component (D): further containing a filler, The epoxy resin composition according to claim 1.

3. In the component (C), Y and Z are each 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, The epoxy resin composition according to claim 1.

4. In the component (C), The compound represented by formula (1) 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 formula (2) 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; The epoxy resin composition according to claim 1.

5. Component (D): further containing a filler, The epoxy resin composition according to claim 4.

6. The epoxy resin composition according to any one of claims 1 to 5, Resin paste.

7. A support; a resin layer comprising the epoxy resin composition according to any one of claims 1 to 5 on the support; having Film type adhesive.

8. A support; a resin layer comprising the epoxy resin composition according to any one of claims 1 to 5 on the support; and a protective layer on the resin layer. having Film type adhesive.

9. A cured product layer of the epoxy resin composition according to any one of claims 1 to 5. Printed wiring board.

10. A cured product layer of the epoxy resin composition according to any one of claims 1 to 5. Semiconductor chip package.

11. An electronic device comprising the printed wiring board according to claim 9.

12. An electronic device comprising the semiconductor chip package of claim 10.

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