Resin composition

Abstract

A resin composition containing (A) a liquid epoxy resin, (B) an inorganic filler, and (C) a first thiol compound having a specific structure, the amount of the (B) inorganic filler being 20 vol% or more with respect to 100 vol% of non-volatile components of the resin composition.

Description

TECHNICAL FIELD

[0001] The present application relates to a resin composition; and a resin sheet, an electronic component, and a semiconductor device each of which uses the resin composition. BACKGROUND

[0002] As a resin composition for adhesion or sealing of electronic components, a resin composition such as an epoxy resin composition is sometimes used. Generally, adhesion or sealing of electronic components is performed using a cured product of a resin composition.

[0003] On the other hand, in the field of electronic components in recent years, high speed and high density are being pursued, and along with this, the amount of heat generated by electronic components has significantly increased. From the viewpoint of efficiently discharging heat generated by electronic components, an improvement in thermal conductivity is required for a cured product of a resin composition. From the viewpoint of improving such thermal conductivity, a resin composition containing an inorganic filler material has been developed (Patent Literature 1).

[0004] PRIOR ART DOCUMENTS PATENT LITERATURE Patent Literature 1: International Publication No. 2018 / 181737 SUMMARY

[0005] PROBLEMS TO BE SOLVED BY THE INVENTION Generally, an inorganic filler material has a higher thermal conductivity than a resin component. Therefore, a cured product of a resin composition containing an inorganic filler material is expected to have high thermal conductivity. Therefore, the present inventors have attempted to fill an inorganic filler material into a resin composition at a high concentration from the viewpoint of improving thermal conductivity.

[0006] However, a resin composition containing an inorganic filler material at a high concentration tends to have a reduced adhesion ability. In particular, there is a tendency for adhesion to an adhesion surface formed of a difficult-to-adhere material such as nickel or liquid crystal polymer (LCP) to be significantly deteriorated. Here, the "difficult-to-adhere material" means a material for which high adhesion strength is difficult to achieve with a general adhesive of the related art.

[0007] The present application is an application created in view of the above problems, and aims to provide a resin composition from which a cured product having both excellent thermal conductivity and adhesion strength can be obtained; a resin sheet containing the resin composition; and an electronic component and a semiconductor device each containing a cured product of the resin composition.

[0008] MEANS FOR SOLVING THE PROBLEMS The present inventors have conducted intensive studies in order to solve the above problem. As a result, the present inventors have found that a resin composition containing (A) a liquid epoxy resin, (B) an inorganic filler material, and (C) a first thiol compound having a specific structure in a specific amount can solve the above problem, thereby completing the present invention.

[0009] That is, the present invention includes the following.

[0010] <1> A resin composition comprising: (A) a liquid epoxy resin, (B) an inorganic filler material, and (C) a first thiol compound represented by the following formula (I), The amount of (B) the inorganic filler material is 20% by volume or more with respect to 100% by volume of non-volatile components of the resin composition, [Chemical Formula 1] (In formula (I), rings P are each independently a phenyl group or a naphthyl group, In the case where the ring P is a phenyl group, 1 to 5 As exist for each ring P, and in the case where the ring P is a naphthyl group, 1 to 7 As exist for each ring P, each A is independently -R 1 -SH, R 1 are each independently a C1 to C6 alkylene group optionally substituted with one or more Ys, B is a group other than A on the ring P, and is each independently a hydrogen atom, a C1 to C6 alkyl group optionally substituted with one or more Ys, or a C1 to C6 alkoxy group optionally substituted with one or more Ys, In the case where the ring P is a phenyl group, A and B are each independently bound at the ortho position, the meta position, or the para position with respect to the position at which the ring P is bound to the main chain, and in the case where the ring P is a naphthyl group, A and B are each independently bound at the ortho position, the meta position, the para position, the ana-position, the epi-position, the cata-position, the peri-position, the pros-position, the amphi-position, or the 2,7 position with respect to the position at which the ring P is bound to the main chain, X is each independently -CH2-, -O-, -N(-R 2 )-, or -S-, R 2 are each independently a hydrogen atom, a C1 to C6 alkyl group optionally substituted with one or more Ys, or a C1 to C6 alkoxy group optionally substituted with one or more Ys, Y is each independently a hydrogen atom, a C1 to C6 alkyl group, or a C1 to C6 alkoxy group, Z is each independently a direct bond, -CH2-, -C2H4-, -C3H6-, -C4H8-, -O-, or -S-, n is an integer of 1 to 20.

[0011] <2> The resin composition according to <1>, wherein (C) the first thiol compound contains one or more selected from the group consisting of a thiol compound represented by the following formula (I-1), a thiol compound represented by the following formula (I-2), a thiol compound represented by the following formula (I-3), a thiol compound represented by the following formula (I-4), a thiol compound represented by the following formula (I-5), and a thiol compound represented by the following formula (I-6), [Chemical Formula 2] .

[0012] <3> The resin composition according to <1> or <2>, wherein (D) a curing agent is contained.

[0013] <4> The resin composition according to <3>, wherein (D) the curing agent contains (D-1) a second thiol compound, (D-1) The second thiol compound has three or more mercapto groups in one molecule, contains a cyclic skeleton, and is not a compound represented by formula (I).

[0014] <5> The resin composition according to <4>, wherein an equivalent ratio of (C) the first thiol compound to (D-1) the second thiol compound is 0.1 or more and 50.0 or less.

[0015] <6> The resin composition according to any one of <1> to <5>, wherein (B) the inorganic filler material has a thermal conductivity of 1.0 W / mK or more and 300 W / mK or less.

[0016] <7> The resin composition according to any one of <1> to <6>, wherein (B) the inorganic filler material has a specific surface area of 0.1 m 2 / g or more and 10 m 2 / g or less.

[0017] <8> The resin composition according to any one of <1> to <7>, wherein (E) a storage stabilizer is contained.

[0018] <9> The resin composition according to any one of <1> to <8>, wherein (F) a curing accelerator is contained.

[0019] <10> The resin composition according to any one of <1> to <9>, wherein a cured product obtained by curing the resin composition at 80°C for 60 minutes has a thermal conductivity of 0.5 W / mK or more and 10 W / mK or less.

[0020] <11> The resin composition according to any one of <1> to <10>, wherein a cured product obtained by curing the resin composition at 80°C for 60 minutes has a tensile elastic modulus of 10 MPa or more and 5,000 MPa or less.

[0021] <12> The resin composition according to any one of <1> to <11>, wherein a cured product obtained by curing the resin composition at 80°C for 60 minutes has an elongation at break of 3% or more and 300% or less.

[0022] <13> A resin sheet having: a support body; and a resin composition layer formed on the support body, The resin composition layer contains the resin composition according to any one of <1> to <12>.

[0023] <14> An electronic component having: a heat sink; a cured product of the resin composition according to any one of <1> to <12> provided on the heat sink; and an electronic part mounted on the cured product.

[0024] <15> A semiconductor device containing a cured product of the resin composition according to any one of <1> to <12>.

[0025] Effects of the Invention According to the present application, it is possible to provide a resin composition capable of obtaining a cured product excellent in both thermal conductivity and adhesive strength; a resin sheet containing the resin composition; and an electronic component and a semiconductor device containing a cured product of the resin composition.

[0026] Brief Description of the Drawings Figure 1 is a spectrogram showing NMR data of the thiol compound (1) synthesized in Synthesis Example 1.

[0027] Figure 2 is a spectrogram showing NMR data of the thiol compound (2) synthesized in Synthesis Example 2. DETAILED DESCRIPTION

[0028] Hereinafter, the present application will be described in detail with reference to embodiments and examples. However, the present application is not limited to the following embodiments and examples, and can be arbitrarily modified without departing from the scope of the claims and the equivalent range thereof.

[0029] The modes described in the present specification can be used in combination with each other regardless of the expressions of "preferable", "more preferable", and the like. For example, the recitation of a numerical range can use a range obtained by combining the upper limit and the lower limit of each range and the numerical value of the example. Furthermore, the terms "containing" and "including" can be replaced with "formed substantially of" or "formed only of".

[0030] In the present specification, the expression "Cp to Cq" (p and q are natural numbers satisfying p < q) attached before the name of a group means that the number of carbon atoms of the group is p or more and q or less. Thus, for example, the expression "C1 to C6 alkyl group" means "alkyl group having 1 or more and 6 or less carbon atoms". In addition, for example, the expression "C1 to C6 alkoxy group" means "alkoxy group having 1 or more and 6 or less carbon atoms".

[0031] In the present specification, with respect to a compound, a group, or a ring, the term "optionally substituted with a substituent" means both a case where a hydrogen atom of the compound, the group, or the ring is not substituted with a substituent and a case where a part or all of the hydrogen atoms of the compound, the group, or the ring are substituted with a substituent, unless otherwise specified.

[0032] <Summary of resin composition> An embodiment of the present application relates to a resin composition containing (A) a liquid epoxy resin, (B) an inorganic filler, and (C) a first mercaptan compound represented by formula (I). Hereinafter, the " (C) first mercaptan compound represented by formula (I)" is sometimes referred to as " (C) first mercaptan compound". In the resin composition relating to the present embodiment, the amount of the (B) inorganic filler is in a specific range.

[0033] [Chemical Formula 3] (In formula (I), each of the rings P is independently a phenyl group or a naphthyl group, In the case where the ring P is a phenyl group, 1 to 5 As exist for each of the rings P, and in the case where the ring P is a naphthyl group, 1 to 7 As exist for each of the rings P, each of the As is independently -R 1 -SH, R 1 is independently a C1 to C6 alkylene group optionally substituted with 1 or more Ys, B is a group other than A on the ring P, and is independently a hydrogen atom, a C1 to C6 alkyl group optionally substituted with 1 or more Ys, or a C1 to C6 alkoxy group optionally substituted with 1 or more Ys, In the case where the ring P is a phenyl group, the A and the B are independently bound to an ortho position, a meta position, or a para position with respect to a position at which the ring P is bound to a main chain, and in the case where the ring P is a naphthyl group, the A and the B are independently bound to an ortho position, a meta position, a para position, a peri position, an epicar position, a meso position, a proximal position, a prev position, a trans position, or a 2,7 position with respect to a position at which the ring P is bound to a main chain, X is independently -CH2-, -O-, -N(-R 2 )-, or -S-, R 2each independently is a hydrogen atom, a C1-C6 alkyl group optionally substituted with 1 or more Y, or a C1-C6 alkoxy group optionally substituted with 1 or more Y, each independently is a hydrogen atom, a C1-C6 alkyl group optionally substituted with 1 or more Y, or a C1-C6 alkoxy group optionally substituted with 1 or more Y, each independently is a direct bond, -CH2-, -C2H4-, -C3H6-, -C4H8-, -O-, or -S-, n is an integer of 1 to 20.

[0034] According to the resin composition relating to the present embodiment, a cured product excellent in both thermal conductivity and adhesive strength can be obtained. In addition, the cured product can generally have excellent mechanical strength and high moisture resistance.

[0035] (A) Liquid Epoxy Resin The resin composition relating to the present embodiment contains, as a (A) component, a (A) liquid epoxy resin. The (A) liquid epoxy resin means an epoxy resin that is in a liquid state at a temperature of 20°C.

[0036] The (A) liquid epoxy resin preferably contains a liquid epoxy resin having 2 or more epoxy groups in 1 molecule. The proportion of the liquid epoxy resin having 2 or more epoxy groups in 1 molecule with respect to 100 mass% of the (A) liquid epoxy resin is preferably 50 mass% or more, more preferably 60 mass% or more, further preferably 70 mass% or more, and can be 100 mass%.

[0037] As the (A) liquid epoxy resin, for example, a bisphenol A type liquid epoxy resin, a bisphenol E type liquid epoxy resin, a bisphenol F type liquid epoxy resin, a bisphenol AF type liquid epoxy resin, a naphthalene type liquid epoxy resin, a glycidyl ester type liquid epoxy resin, a glycidyl amine type liquid epoxy resin, a phenol novolak type liquid epoxy resin, a trimethylolpropane type liquid epoxy resin, a neopentyl glycol type liquid epoxy resin, an alicyclic liquid epoxy resin having an ester skeleton, a cyclohexane type liquid epoxy resin, a cyclohexanedimethanol type liquid epoxy resin, a tert-butyl catechol type liquid epoxy resin, and a liquid epoxy resin having a butadiene structure can be given. The (A) liquid epoxy resin can be used alone as one kind or in combination with two or more kinds.

[0038] As specific examples of the liquid epoxy resin (A), "HP4032", "HP4032D", "HP4032SS" (naphthalene type liquid epoxy resin) manufactured by DIC Corporation; "HP-820" (tert-butyl catechol type epoxy resin) manufactured by DIC Corporation; "828US", "828EL", "jER828EL", "825", "Epikote 828EL" (bisphenol A type liquid epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER807", "1750" (bisphenol F type liquid epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER152" (phenol novolak type liquid epoxy resin) manufactured by Mitsubishi Chemical Corporation; "630", "630LSD", "604" (glycidyl amine type liquid epoxy resin) manufactured by Mitsubishi Chemical Corporation; "ED-523T" (epoxy propoxy type liquid epoxy resin) manufactured by ADEKA Corporation; "EP-3950L", "EP-3980S" (glycidyl amine type liquid epoxy resin) manufactured by ADEKA Corporation; "EP-4088S" (dicyclopentadiene type liquid epoxy resin) manufactured by ADEKA Corporation; "ZX1059" (mixture of bisphenol A type liquid epoxy resin and bisphenol F type liquid epoxy resin) manufactured by NIPPON STEEL Chemical & Material Co., Ltd.; "R1710" (bisphenol E type liquid epoxy resin) manufactured by PRINTEC Corporation; "EX-721" (glycidyl ester type liquid epoxy resin) manufactured by Nagase Chemtex Corporation; "CELLOXIDE 2021P" (alicyclic liquid epoxy resin having an ester skeleton) manufactured by Daicel Corporation; "PB-3600", "JP-100", "JP-200" (liquid epoxy resin having a butadiene structure) manufactured by Japan Cabot Corporation; "ZX1658", "ZX1658GS" (liquid 1,4-glycidyl cyclohexane type liquid epoxy resin) manufactured by NIPPON STEEL Chemical & Material Co., Ltd.; "ED-503", "ED-503G" (hexanediol type liquid epoxy resin) manufactured by ADEKA Corporation; "ED-505" (trimethylolpropane type liquid epoxy resin) manufactured by ADEKA Corporation; "ED-506" (polypropylene glycol type liquid epoxy resin) manufactured by ADEKA Corporation; "ED-523T" (neopentyl glycol type liquid epoxy resin) manufactured by ADEKA Corporation, and the like can be given.

[0039] (A) liquid epoxy resin preferably has a small viscosity within a specific range. The range of the viscosity of the (A) liquid epoxy resin is preferably 15000 mPa-s or less, more preferably 10000 mPa-s or less, further preferably 5000 mPa or less, particularly preferably 3000 mPa-s or less. The lower limit value is not particularly limited, and can be, for example, 5 mPa-s or more, 10 mPa-s or more, or the like. The viscosity of the (A) liquid epoxy resin can be measured at 25°C under the conditions of 20 rpm using an E-type viscometer (using, for example, a cone-shaped rotor of "RE-25U" by Toyo Seiki Jidoki Kogyo, 1° 34' x R24).

[0040] The range of the epoxy equivalent of the (A) liquid epoxy resin is preferably 50 g / eq. to 5000 g / eq., more preferably 50 g / eq. to 3000 g / eq., further preferably 80 g / eq. to 2000 g / eq., particularly preferably 110 g / eq. to 1000 g / eq. The epoxy equivalent represents the mass of an epoxy resin containing 1 equivalent of an epoxy group. The epoxy equivalent can be measured in accordance with JIS K7236.

[0041] The range of the weight average molecular weight (Mw) of the (A) liquid epoxy resin is preferably 100 to 5000, more preferably 150 to 3000, further preferably 200 to 1500. Unless otherwise specified, the weight average molecular weight of a resin such as the (A) liquid epoxy resin represents a polystyrene-converted weight average molecular weight measured by a gel permeation chromatography (GPC) method.

[0042] The range of the amount of the (A) liquid epoxy resin is preferably 1% by mass or more, more preferably 5% by mass or more, particularly preferably 10% by mass or more, with respect to 100% by mass of the nonvolatile components in the resin composition, and is preferably 40% by mass or less, more preferably 30% by mass or less, particularly preferably 20% by mass or less. Unless otherwise specified, the nonvolatile components in the resin composition represent the components obtained by removing the (H) solvent from the resin composition. When the amount of the (A) liquid epoxy resin is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and the mechanical strength and the moisture resistance of the cured product are usually particularly good.

[0043] The amount of the (A) liquid epoxy resin is preferably 10% by mass or more, more preferably 20% by mass or more, further preferably 30% by mass or more, and preferably 70% by mass or less, more preferably 60% by mass or less, and further preferably 50% by mass or less, relative to 100% by mass of the resin component in the resin composition. The resin component of the resin composition means the component excluding the (B) inorganic filler material from the nonvolatile component of the resin composition, unless otherwise specified. When the amount of the (A) liquid epoxy resin is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and the mechanical strength and the moisture resistance of the cured product can be generally particularly good.

[0044] < (B) Inorganic Filler Material > The resin composition according to the present embodiment contains the (B) inorganic filler material as a (B) component. The (B) inorganic filler material is a particle of an inorganic material. Therefore, the (B) inorganic filler material is contained in the resin composition in the state of a particle, and is generally contained in the cured product while maintaining the state of the particle. In general, an inorganic material has a higher thermal conductivity than a resin component. Therefore, the cured product of the resin composition containing the (B) inorganic filler material can have a high thermal conductivity.

[0045] As the inorganic material forming the (B) inorganic filler material, an inorganic compound is generally used. As the material of the (B) inorganic filler material, for example, silica, alumina, glass, cordierite, silicon 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 tungstic phosphate, and the like can be given. The (B) inorganic filler material can be used alone as one kind or in combination with two or more kinds.

[0046] The (B) inorganic filler material preferably has a high thermal conductivity. Specifically, the thermal conductivity of the (B) inorganic filler material is preferably 1.0 W / mK or more, more preferably 2.0 W / mK or more, further preferably 5.0 W / mK or more, further preferably 10 W / mK or more, and particularly preferably 15 W / mK or more. The upper limit is generally 1000 W / mK or less, and is preferably 300 W / mK or less. When the thermal conductivity of the (B) inorganic filler material is within the above range, the thermal conductivity of the cured product of the resin composition can be effectively improved.

[0047] The thermal conductivity of the (B) inorganic filler material can be measured by a laser flash method.

[0048] As the (B) inorganic filler material having a high thermal conductivity, for example, particles of an inorganic material selected from one or more of silicon dioxide, boron nitride, aluminum nitride, alumina (alumina), and silicon carbide can be given. Among them, particles of an inorganic material selected from one or more of silicon dioxide, aluminum nitride, alumina, and silicon carbide are preferable; and particles of alumina are particularly preferable.

[0049] The average particle diameter D50 of the (B) inorganic filler material is preferably 0.01 μm or more, more preferably 0.1 μm or more, further preferably 1.0 μm or more, particularly preferably 10 μm or more, and is preferably 100 μm or less, more preferably 50 μm or less, further preferably 30 μm or less. When the average particle diameter D50 of the (B) inorganic filler material is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and the mechanical strength and the moisture resistance of the cured product are usually particularly good.

[0050] The average particle diameter D50 of the (B) inorganic filler material can be measured by a laser diffraction-scattering method based on Mie scattering theory. Specifically, it can be measured by using a laser diffraction scattering type particle size distribution measuring device to make a particle size distribution of the (B) inorganic filler material on a volume basis, and from the particle size distribution, the average particle diameter D50 as a median particle diameter can be measured. The measurement sample can preferably use a substance obtained by dispersing the (B) inorganic filler material in water by ultrasonic waves. As the laser diffraction scattering type particle size distribution measuring device, "LA-960" manufactured by HORIBA, Ltd., "SALD-2200" manufactured by Shimadzu Corporation, or the like can be used.

[0051] The specific surface area of the (B) inorganic filler material is preferably 0.1 m 2 / g or more, more preferably 0.2 m 2 / g or more, further preferably 0.3 m 2 / g or more, preferably 10 m 2 / g or less, more preferably 7 m 2 / g or less, further preferably 5 m 2 / g or less, particularly preferably 2 m 2 / g or less. When the specific surface area of the (B) inorganic filler material is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and the mechanical strength and the moisture resistance of the cured product are usually particularly good.

[0052] The specific surface area of the (B) inorganic filler material can be measured by the following method, that is, by using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Corporation) to adsorb nitrogen gas to the surface of a sample according to the BET method, and calculating the specific surface area using the BET multipoint method.

[0053] For the (B) inorganic filler material, from the viewpoint of improving the moisture resistance and the dispersibility, surface treatment with a surface treatment agent can also be performed. As the surface treatment agent, for example, an aminosilane-based coupling agent, an epoxy silane-based coupling agent, a mercapto silane-based coupling agent, a silane-based coupling agent, an alkoxy silane, an organosilazane compound, a titanate-based coupling agent, and the like can be cited. The surface treatment agent can be used alone in one kind, or two or more kinds can be used in combination as desired.

[0054] As the commercially available product of the surface treatment agent, for example, "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM5783" (N-phenyl-3-aminooctyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "SZ-31" (hexamethyldisilazane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM103" (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-4803" (long-chain epoxy-type silane coupling agent) manufactured by Shin-Etsu Chemical Co., Ltd., and the like can be cited.

[0055] From the viewpoint of improving the dispersibility of the (B) inorganic filler material, the degree of surface treatment with the surface treatment agent is preferably controlled within a specific range. Specifically, for 100 parts by mass of the inorganic filler material, surface treatment with 0.2 parts by mass to 5 parts by mass of the surface treatment agent is preferred, surface treatment with 0.2 parts by mass to 3 parts by mass of the surface treatment agent is more preferred, and surface treatment with 0.3 parts by mass to 2 parts by mass of the surface treatment agent is further preferred.

[0056] The degree of surface treatment with the surface treatment agent can be evaluated by the carbon amount per unit surface area of the (B) inorganic filler material. For the carbon amount per unit surface area of the (B) inorganic filler material, from the viewpoint of improving the dispersibility of the (B) inorganic filler material, 0.02 mg / m 2 More preferably, 0.1 mg / m 2 Further preferably, 0.2 mg / m 2 Above. On the other hand, from the viewpoint of suppressing the increase in the melt viscosity of the resin composition, 1.0 mg / m 2 More preferably, 0.8 mg / m 2 Further preferably, 0.5 mg / m 2 Below.

[0057] (B) The amount of carbon per unit surface area of the inorganic filler material can be measured after washing the inorganic filler material subjected to surface treatment with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler material subjected to surface treatment with a surface treatment agent, and ultrasonic washing is performed at 25°C for 5 minutes. After removing the supernatant and drying the solid content, the amount of carbon per unit surface area of the inorganic filler material can be measured using a carbon analyzer, such as "EMIA-320V" manufactured by HORIBA, Ltd.

[0058] The amount of (B) the inorganic filler material is preferably 30% by volume or more, more preferably 40% by volume or more, and particularly preferably 50% by volume or more, and is preferably 90% by volume or less, more preferably 80% by volume or less, and particularly preferably 70% by volume or less, with respect to 100% by volume of the nonvolatile components in the resin composition. When the amount of (B) the inorganic filler material is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be improved effectively, and the mechanical strength and the moisture resistance of the cured product are particularly good in general.

[0059] The volume content ratio (vol%) of each component contained in the resin composition is calculated from the mass of the component contained in the resin composition. Specifically, the volume of each component can be calculated by dividing the mass by the specific gravity, and the volume content ratio (vol%) can be calculated from the calculated volume of each component.

[0060] The amount of (B) the inorganic filler material is preferably 30% by mass or more, more preferably 40% by mass or more, and particularly preferably 50% by mass or more, and is preferably 90% by mass or less, more preferably 80% by mass or less, and particularly preferably 70% by mass or less, with respect to 100% by mass of the nonvolatile components in the resin composition. When the amount of (B) the inorganic filler material is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be improved effectively, and the mechanical strength and the moisture resistance of the cured product are particularly good in general.

[0061] < (C) First Thiol Compound > The resin composition according to the present embodiment contains, as the (C) component, a (C) first mercaptan compound. The (C) first mercaptan compound is represented by the following formula (I). The (C) first mercaptan compound is capable of reacting with the (A) liquid epoxy resin to cure the resin composition. Since the (C) first mercaptan compound has high reactivity with the (A) liquid epoxy resin, the resin composition according to the present embodiment is generally capable of curing at a lower curing temperature than in the past.

[0062] [Chemical Formula 4] In formula (I), each ring P is independently a phenyl group or a naphthyl group. The ring P is preferably a phenyl group.

[0063] In formula (I), in the case where the ring P is a phenyl group, there are generally 1 to 5 As, preferably 1 to 3 As, more preferably 1 to 2 As, and further preferably 1 A, for each ring P. In the case where the ring P is a naphthyl group, there are generally 1 to 7 As, preferably 1 to 5 As, more preferably 1 to 3 As, and further preferably 1 to 2 As, for each ring P.

[0064] Each A is independently -R 1 -SH. R 1 is independently a C1 to C6 alkylene group optionally substituted with one or more Ys. R 1 is preferably an unsubstituted C2 to C5 alkylene group; more preferably an unsubstituted C2 to C3 alkylene group. The alkylene group can be straight-chained or branched, and can be saturated or unsaturated. Furthermore, the alkylene group can or can not be substituted with Y. Y is defined below.

[0065] In formula (I), B is a group other than A on the ring P. Thus, in the case where the ring P is a phenyl group, the total number of groups A and groups B on one ring P is 5, and in the case where the ring P is a naphthyl group, the total number of groups A and groups B on one ring P is 7. As the number of groups A and groups B on one ring P, for example, there are 1 to 2 As and 0 to 2 Bs other than hydrogen atoms for each ring P; more preferably, there is 1 A and 0 to 1 Bs other than hydrogen atoms for each ring P.

[0066] B is each independently a hydrogen atom, a C1-C6 alkyl group optionally substituted with 1 or more Y, or a C1-C6 alkoxy group optionally substituted with 1 or more Y. Y is defined below. Preferably, B is each independently a hydrogen atom, an unsubstituted C1-C3 alkyl group, or an unsubstituted C1-C3 alkoxy group; more preferably, B is each independently a hydrogen atom, a methyl group, or a methoxy group; further preferably, B is a hydrogen atom. All of B can be hydrogen atoms. Alternatively, as another mode, one or two of B present in each ring P can be a methyl group, a methoxy group, or a phenyl group, and all of the other B present in each ring P can be hydrogen atoms. In the case where the ring P is a phenyl group, generally 0 to 4, preferably 0 to 3, more preferably 1 to 2, of B can be other than a hydrogen atom for each ring P. In the case where the ring P is a naphthyl group, generally 0 to 6, preferably 0 to 5, more preferably 1 to 3, further preferably 1 to 2, of B can be other than a hydrogen atom for each ring P.

[0067] In the case where the ring P is a phenyl group, A and B can be each independently bound at the ortho position, the meta position, or the para position with respect to the position at which the ring P is bound to the main chain. Preferably, A and B can be each independently bound at the ortho position or the para position with respect to the position at which the ring P is bound to the main chain. As a more preferred embodiment, one A is present on the ring P, and no B other than a hydrogen atom is present on the ring P or one B other than a hydrogen atom is present, the A is bound at the ortho position or the para position with respect to the position at which the ring P is bound to the main chain, and B, when present, is bound at the ortho position with respect to the position at which the ring P is bound to the main chain. In particular, A is preferably bound at the ortho position with respect to the position at which the ring P is bound to the main chain.

[0068] In the case where the ring P is a naphthyl group, A and B can be each independently bound at the ortho position, the meta position, the para position, the peri position, the epi position, the meso position, the proximal position, the pre position, the bay position, or the 2,7 position with respect to the position at which the ring P is bound to the main chain. Preferably, A and B can be each independently bound at the peri position, the epi position, the meso position, the proximal position, the bay position, or the 2,7 position with respect to the position at which the ring P is bound to the main chain. As a more preferred embodiment, one A is present on the ring P, and no B other than a hydrogen atom is present on the ring P or one B other than a hydrogen atom is present, the A is bound at the bay position or the 2,7 position with respect to the position at which the ring P is bound to the main chain, and B, when present, is bound at the bay position or the 2,7 position with respect to the position at which the ring P is bound to the main chain.

[0069] In formula (I), X is each independently -CH2-, -O-, -N(-R 2 ) -, or -S-. Here, R 2 is each independently a hydrogen atom, a C1-C6 alkyl group optionally substituted with 1 or more Y, or a C1-C6 alkoxy group optionally substituted with 1 or more Y. R 2unsubstituted C2-C5alkylene; more preferably, unsubstituted C2-C3alkylene. The alkylene group can be linear or branched, saturated or unsaturated. Further, the alkylene group can or can not be substituted with Y. Y is defined below. X is preferably -CH2- or -O-, more preferably -O-.

[0070] In formula (I), Y is independently a hydrogen atom, a C1-C6alkyl group or a C1-C6alkoxy group. Y is preferably a hydrogen atom, a methyl group or an ethyl group; more preferably, a hydrogen atom.

[0071] In formula (I), Z is independently a direct bond, -CH2-, -C2H4-, -C3H6-, -C4H8-, -O- or -S-. Z is preferably a direct bond, -CH2-, -O- or -S-; more preferably, a direct bond or -O-; further preferably, a direct bond.

[0072] In formula (I), n is an integer of 1 to 20. n is preferably an integer of 1 to 10; more preferably, an integer of 2 to 5 or 1 to 3.

[0073] As specific examples of the (C) first thiol compound, there can be mentioned a thiol compound represented by the following formula (I-1), a thiol compound represented by the following formula (I-2), a thiol compound represented by the following formula (I-3), a thiol compound represented by the following formula (I-4), a thiol compound represented by the following formula (I-5), and a thiol compound represented by the following formula (I-6). Of these, the thiol compound represented by formula (I-1) and the thiol compound represented by formula (I-3) are preferred; the thiol compound represented by formula (I-1) is particularly preferred.

[0074] [Chemical Formula 5] .

[0075] The (C) first thiol compound can be used alone or in combination of two or more.

[0076] The method for producing the (C) first thiol compound is not limited. For example, the thiol compound represented by formula (I-1) can be produced by the following method. First, 2-allylphenol and 1,4-dibromobutane as starting materials, tetrabutylammonium bromide as a phase transfer catalyst, and methyl isobutyl ketone (MIBK) as a reaction solvent are mixed and dissolved. In one example, after mixing, the mixture is dissolved at generally 50°C to 200°C, preferably 60°C to 150°C, more preferably 100°C ± 10 to 20°C (i.e., 80°C to 120°C, or 90°C to 110°C) for generally 1 minute to 12 hours, preferably 10 minutes to 5 hours, more preferably 30 minutes ± 10 to 20 minutes (i.e., 10 minutes to 50 minutes, or 20 minutes to 40 minutes). The resulting solution is mixed with a base such as an aqueous KOH solution, and further, only MIBK is returned to the system at a temperature range of generally 100°C to 150°C, preferably 110°C to 120°C, while distilling off water to react. The reaction time is generally 1 hour to 24 hours, preferably 2 hours to 10 hours, more preferably 6 hours ± 1 hour (i.e., 5 hours to 7 hours). Then, the temperature is lowered to about 60°C, distilled water is added, and left to stand, and the lower salt water layer as a by-product is discarded. Further, distilled water and a base (for neutralization, an appropriate amount of sodium dihydrogen phosphate or the like) are added, left to stand, and the lower salt water layer as a by-product is discarded. Further, an equal amount of distilled water is added, and water washing purification is performed generally 1 to 5 times, preferably 2 to 3 times. Then, heated to, for example, 50°C to 200°C, preferably 60°C to 150°C, more preferably 120°C ± 10 to 20°C (i.e., 100°C to 140°C, or 110°C to 130°C), and azeotropic dehydration is performed. The resulting solution is subjected to fine filtration to remove impurities, and MIBK and unreacted 2-allylphenol are distilled off under reduced pressure to obtain a liquid resin. The resulting liquid resin, thioacetic acid, toluene, and azobisisobutyronitrile (AIBN) are mixed and reacted. The reaction temperature of this reaction is, for example, 50°C to 200°C, preferably 60°C to 150°C, more preferably 80°C ± 10 to 20°C (i.e., 60°C to 100°C, or 70°C to 90°C). In addition, the reaction time is, for example, 30 minutes to 24 hours, preferably 1 hour to 10 hours, more preferably 4 hours ± 1 to 2 hours (i.e., 2 hours to 6 hours, or 3 hours to 5 hours). After removing toluene from the resulting reaction product, crystallization is performed with methanol, the crystals are dried and recovered. The recovered dried crystals and a base such as NaOH are mixed and reacted. The reaction temperature of this reaction is, for example, 50°C to 200°C, preferably 60°C to 150°C, more preferably 80°C ± 10 to 20°C (i.e., 60°C to 100°C, or 70°C to 90°C). In addition, the reaction time is, for example, 30 minutes to 12 hours, preferably 1 hour to 5 hours, more preferably 2 hours ± 1 hour (i.e., 1 hour to 3 hours).After neutralization with an acid such as hydrochloric acid added to the reaction mixture, the organic layer is separated and washed with water. Removal of toluene from the washed organic layer makes it possible to obtain the target mercaptan compound. The specific production method can employ the method described in the specification of Japanese Patent Application No. 2023-057934.

[0077] The amount of the (C) first mercaptan compound is preferably 1% by mass or more, more preferably 5% by mass or more, and particularly preferably 8% by mass or more, and is preferably 30% by mass or less, more preferably 20% by mass or less, and particularly preferably 15% by mass or less, with respect to 100% by mass of the nonvolatile components in the resin composition. When the amount of the (C) first mercaptan compound is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and the mechanical strength and the moisture resistance of the cured product are typically particularly excellent.

[0078] The amount of the (C) first mercaptan compound is preferably 10% by mass or more, more preferably 20% by mass or more, further preferably 30% by mass or more, and particularly preferably 35% by mass or more, and is preferably 60% by mass or less, more preferably 50% by mass or less, and particularly preferably 40% by mass or less, with respect to 100% by mass of the resin components in the resin composition. When the amount of the (C) first mercaptan compound is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and the mechanical strength and the moisture resistance of the cured product are typically particularly excellent.

[0079] The mass ratio of the (C) first mercaptan compound to the (A) liquid epoxy resin ((C) first mercaptan compound / (A) liquid epoxy resin) is preferably 0.1 or more, more preferably 0.3 or more, further preferably 0.5 or more, and particularly preferably 0.8 or more, and is preferably 2.0 or less, more preferably 1.5 or less, further preferably 1.0 or less, and particularly preferably 0.9 or less. When the mass ratio of the (C) first mercaptan compound to the (A) liquid epoxy resin ((C) first mercaptan compound / (A) liquid epoxy resin) is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and the mechanical strength and the moisture resistance of the cured product are typically particularly excellent.

[0080] The mass ratio of the (C) first mercaptan compound to the (B) inorganic filler ((C) first mercaptan compound / (B) inorganic filler) is preferably 0.01 or more, more preferably 0.05 or more, further preferably 0.08 or more, and particularly preferably 0.12 or more, and is preferably 0.8 or less, more preferably 0.5 or less, and particularly preferably 0.2 or less. When the mass ratio of the (C) first mercaptan compound to the (B) inorganic filler ((C) first mercaptan compound / (B) inorganic filler) is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and the mechanical strength and the moisture resistance of the cured product are typically particularly excellent.

[0081] In the resin composition, the ratio of the number of mercapto groups of the (C) first mercaptan compound to the number of epoxy groups of the (A) liquid epoxy resin (mercapto / epoxy) is preferably within a specific range. The range of the above ratio (mercapto / epoxy) is preferably 0.1 or more, more preferably 0.2 or more, further preferably 0.3 or more, preferably 2.0 or less, more preferably 1.5 or less, further preferably 1.0 or less, particularly preferably 0.8 or less. The "number of epoxy groups of the (A) liquid epoxy resin" in the resin composition means the value obtained by dividing the mass of the nonvolatile component of the (A) liquid epoxy resin present in the resin composition by the epoxy equivalent weight thereof, and the values are all added together. In addition, the "number of mercapto groups of the (C) first mercaptan compound" in the resin composition means the value obtained by dividing the mass of the nonvolatile component of the (C) first mercaptan compound present in the resin composition by the mercapto equivalent weight thereof, and the values are all added together. In addition, the mercapto equivalent weight means the mass of a resin containing 1 equivalent of mercapto group. When the above ratio (mercapto / epoxy) is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and furthermore, the mechanical strength and the moisture resistance of the cured product are usually particularly good.

[0082] The resin composition can contain any mercaptan compound such as the mercaptan-based curing agent described later in combination with the (C) first mercaptan compound. In the resin composition according to the present embodiment, the ratio of the number of epoxy groups of the (A) liquid epoxy resin to the total number of mercapto groups of the mercaptan compounds including the (C) first mercaptan compound and any mercaptan compound (epoxy / mercapto) is preferably within a specific range. The range of the above ratio (epoxy / mercapto) is preferably 0.1 or more, more preferably 0.4 or more, further preferably 0.8 or more, particularly preferably greater than 1.0, preferably 2.0 or less, more preferably 1.8 or less, further preferably 1.6 or less, further preferably 1.4 or less. The "total number of mercapto groups of the mercaptan compounds" in the resin composition means the value obtained by dividing the mass of the nonvolatile component of the mercaptan compounds present in the resin composition (including the (C) first mercaptan compound and any mercaptan compound) by the mercapto equivalent weight thereof, and the values are all added together. When the above ratio (mercapto / epoxy) is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and furthermore, the mechanical strength and the moisture resistance of the cured product are usually particularly good.

[0083] The total amount of (A) liquid epoxy resin, (B) inorganic filler, and (C) first thiol compound, relative to the nonvolatile components in the resin composition, is preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 70% by mass or more, further preferably 80% by mass or more, further preferably 90% by mass or more. The upper limit is usually 100% by mass or less, and can also be 99% by mass or less.

[0084] (D) Curing Agent The resin composition according to the present embodiment can also include a (D) curing agent as an arbitrary component. The (D) curing agent according to the present embodiment refers to a curable resin that is capable of reacting with the (A) liquid epoxy resin to cure the resin composition. The (D) curing agent does not include substances corresponding to the above-mentioned (A) to (C) components. One kind of (D) curing agent can be used alone, or two or more kinds of (D) curing agents can be used in combination.

[0085] As the (D) curing agent, for example, active ester-based curing agents, phenol-based curing agents, carbodiimide-based curing agents, cyanate-based curing agents, benzoxazine-based curing agents, acid anhydride-based curing agents, amine-based curing agents, and thiol-based curing agents can be given. Among these, a thiol-based curing agent is preferable.

[0086] As the thiol-based curing agent, a thiol compound that is capable of reacting with the (A) liquid epoxy resin to cure the resin composition can be used. The thiol-based curing agent generally has one or more mercapto groups in one molecule. From the viewpoint of increasing the crosslinking density, the number of mercapto groups in one molecule of the thiol-based curing agent is preferably two or more, more preferably three or more. The upper limit is preferably six or less, more preferably five or less.

[0087] Among the thiol-based curing agents, a substance having a cyclic skeleton is preferable; further preferably, a (D-1) thiol compound having three or more mercapto groups in one molecule, having a cyclic skeleton, and not represented by formula (I). Hereinafter, the (D-1) thiol compound having three or more mercapto groups in one molecule, having a cyclic skeleton, and not represented by formula (I) is sometimes referred to as a (D-1) second thiol compound. When the (D-1) second thiol compound is used, the moisture resistance of the cured product of the resin composition can be particularly effectively improved. Therefore, the (D) curing agent preferably includes the (D-1) second thiol compound, and can include only the (D-1) second thiol compound.

[0088] As the (D-1) second thiol compound, a non-ester thiol compound that does not have an ester structure (-C(=O)-O-) can be used, an ester thiol compound that has an ester structure can be used, or both can be used in combination.

[0089] As the non-ester thiol compound which can be used as the second thiol compound (D-1), for example, an alkyl isocyanurate type thiol compound, an alkyl glycoluril type thiol compound can be given.

[0090] The alkyl isocyanurate type thiol compound is a compound having a structure in which an alkyl group is bonded to the nitrogen atoms at positions 1, 3, and 5 of isocyanuric acid, respectively, and having a mercapto group. The number of carbon atoms of the alkyl group is preferably 1 to 10, more preferably 1 to 6, further preferably 1 to 3, further preferably 2 or 3, further preferably 3. In the alkyl isocyanurate type thiol compound, a compound having 3 or more mercapto groups in one molecule can be used as the second thiol compound (D-1). As the alkyl isocyanurate type thiol compound which can be used as the second thiol compound (D-1), for example, a 3-functional alkyl isocyanurate type thiol compound such as tris(3-mercaptopropyl) isocyanurate, tris(2-mercaptopropyl) isocyanurate, tris(2-mercaptoethyl) isocyanurate, 1,3,5-tris[3-(2-mercaptoethylsulfanyl)propyl] isocyanurate, and the like can be given.

[0091] The alkyl glycoluril type thiol compound is a compound having a structure in which an alkyl group is bonded to at least one of positions 1, 3, 4, 6, 3a, and 6a of glycoluril (i.e., tetrahydroimidazo[4,5-d]imidazole-2,5(1H,3H)-dione), and having a mercapto group. The number of carbon atoms of the alkyl group is preferably 1 to 10, more preferably 1 to 6, further preferably 1 to 3, further preferably 2 or 3, further preferably 3. In the alkyl glycoluril type thiol compound, a compound having 3 or more mercapto groups in one molecule can be used as the second thiol compound (D-1). As the alkyl glycoluril type thiol compound which can be used as the second thiol compound (D-1), for example, a 3-functional alkyl glycoluril type thiol compound such as 1,3,4-tris(2-mercaptoethyl) glycoluril, 1,3,4-tris(3-mercaptopropyl) glycoluril, and the like; a 4-functional alkyl glycoluril type thiol compound such as 1,3,4,6-tetrakis(2-mercaptoethyl) glycoluril, 1,3,4,6-tetrakis(3-mercaptopropyl) glycoluril, and the like can be given.

[0092] As the ester type thiol compound which can be used as the second thiol compound (D-1), for example, a carboxylic acid ester isocyanurate type thiol compound can be given.

[0093] The carboxylate isocyanurate type mercaptan compound is a compound having a mercapto group and including an alkyl group bonded to the nitrogen atoms at positions 1, 3, and 5 of isocyanuric acid (i.e., 1,3,5-triazine-2,4,6(1H,3H,5H)-trione). The number of carbon atoms of the alkyl group is preferably 1 to 10, more preferably 1 to 6, further preferably 1 to 3, further preferably 2 or 3, further preferably 3. In the carboxylate isocyanurate type mercaptan compound, a compound having 3 or more mercapto groups in one molecule can be used as the (D-1) second mercaptan compound. As the carboxylate type mercaptan compound which can be used as the (D-1) second mercaptan compound, 3-functional carboxylate isocyanurate type mercaptan compounds such as tris[2-(3-mercaptopropionyloxy)ethyl]isocyanurate, tris[2-(4-mercaptobutyryloxy)ethyl]isocyanurate, tris[2-(2-mercaptopropionyloxy)ethyl]isocyanurate, tris[2-(3-mercaptopropionyloxy)ethyl]isocyanurate, 1,3,5-tris(3-mercaptopropionyloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and the like can be given.

[0094] In the above, as the (D-1) second mercaptan compound, a non-ester type mercaptan compound is preferred. Therefore, the (D-1) second mercaptan compound preferably contains a non-ester type mercaptan compound, and can contain only a non-ester type mercaptan compound. When a non-ester type mercaptan compound is used, the moisture resistance of the resin composition can be particularly effectively improved.

[0095] Further, as the (D-1) second mercaptan compound, among non-ester type mercaptan compounds, an alkyl isocyanurate type mercaptan compound is preferred. Therefore, the (D-1) second mercaptan compound preferably contains an alkyl isocyanurate type mercaptan compound, and can contain only an alkyl isocyanurate type mercaptan compound. When an alkyl isocyanurate type mercaptan compound is used, the wettability of the (B) inorganic filler and the resin component can be improved, and the elongation and the adhesive strength of the cured product can be effectively improved.

[0096] As the second thiol compound (D-1), a commercially available product can also be used. As the commercially available product, for example, "TMPIC" (tris(3-mercaptopropyl)isocyanurate) manufactured by Ajinomoto Fine-Techno Co., Inc.; "SS32" (1,3,5-tris[3-(2-mercaptoethylsulfanyl)propyl]isocyanurate) manufactured by Kawaguchi Chemicals Co., Ltd.; "TS-G" (tetrahydro-1,3,4,6-tetrakis(3-mercaptoethyl)-imidazo[4,5-d]imidazole-2,5(1H,3H)-dione), "C3TS-G" (tetrahydro-1,3,4,6-tetrakis(3-mercaptopropyl)-imidazo[4,5-d]imidazole-2,5(1H,3H)-dione) manufactured by Shikoku Chemicals Corporation; and "TEMPIC" (tris[(3-mercaptopropionyloxy)-ethyl]-isocyanurate) manufactured by Sakai Chemical Industry Co., Ltd. can be mentioned.

[0097] In the resin composition, the equivalent ratio of the first thiol compound (C) to the second thiol compound (D-1) is preferably within a specific range. The above-mentioned equivalent ratio can be expressed by the ratio of the number of mercapto groups of the first thiol compound (C) to the number of mercapto groups of the second thiol compound (D-1) ((C) / (D-1)). Specifically, the above-mentioned equivalent ratio is preferably 0.1 or more, more preferably 1.0 or more, further preferably 1.5 or more, particularly preferably 2.0 or more, and preferably 50.0 or less, more preferably 30.0 or less, further preferably 10.0 or less. The "number of mercapto groups of the second thiol compound (D-1) in the resin composition" means the value obtained by dividing the mass of the non-volatile component of the second thiol compound (D-1) present in the resin composition by the mercapto equivalent thereof, and the values are all added together. When the equivalent ratio is within the above-mentioned range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and further, the mechanical strength and the moisture resistance of the cured product are usually particularly excellent.

[0098] In the resin composition, the ratio of the number of mercapto groups of the second thiol compound (D-1) to the number of epoxy groups of the liquid epoxy resin (A) (mercapto / epoxy) is preferably within a specific range. The ratio (mercapto / epoxy) is preferably 0.01 or more, more preferably 0.05 or more, further preferably 0.1 or more, and preferably 2.0 or less, more preferably 1.0 or less, further preferably 0.5 or less, particularly preferably 0.3 or less. When the ratio (mercapto / epoxy) is within the above-mentioned range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and further, the mechanical strength and the moisture resistance of the cured product are usually particularly excellent.

[0099] The amount of the (D-1) second mercaptan compound is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, further preferably 1% by mass or more, preferably 20% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, particularly preferably 3% by mass or less, relative to 100% by mass of the nonvolatile components in the resin composition. When the amount of the (D-1) second mercaptan compound is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and the mechanical strength and the moisture resistance of the cured product are generally particularly good.

[0100] The amount of the (D-1) second mercaptan compound is preferably 0.1% by mass or more, more preferably 1% by mass or more, further preferably 2% by mass or more, preferably 30% by mass or less, more preferably 20% by mass or less, particularly preferably 10% by mass or less, relative to 100% by mass of the resin components in the resin composition. When the amount of the (D-1) second mercaptan compound is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and the mechanical strength and the moisture resistance of the cured product are generally particularly good.

[0101] The (D) curing agent such as the (D-1) second mercaptan compound can be in a liquid state or in a solid state at 20°C.

[0102] The (D) curing agent such as the (D-1) second mercaptan compound preferably has a weight average molecular weight of 100 or more, more preferably 150 or more, further preferably 200 or more, particularly preferably 250 or more. The upper limit of the weight average molecular weight of the (D) curing agent can be, for example, 5000 or less, 3000 or less, 1500 or less, 1000 or less, 800 or less, 700 or less, or the like.

[0103] The (D) curing agent such as the (D-1) second mercaptan compound preferably has an active group equivalent of 50 g / eq. or more, and can have an active group equivalent of 60 g / eq. or more, 80 g / eq. or more, or 110 g / eq. or more. The upper limit of the active group equivalent of the (D) curing agent can be, for example, 3000 g / eq. or less, 1000 g / eq. or less, 500 g / eq. or less, 300 g / eq. or less, or 200 g / eq. or less. The active group equivalent indicates the mass of the resin per 1 equivalent of the active group. The active group of the (D) curing agent refers to a group that can react with the epoxy group of the (A) liquid epoxy resin, and examples thereof include a mercapto group, a phenolic hydroxyl group, an active ester group, and the like.

[0104] The ratio of the number of active groups of (D) the curing agent to the number of epoxy groups of (A) the liquid epoxy resin (active group / epoxy group) in the resin composition is preferably within a specific range. The ratio of the active group / epoxy group is preferably 0.01 or more, more preferably 0.05 or more, further preferably 0.1 or more, preferably 2.0 or less, more preferably 1.0 or less, further preferably 0.5 or less, particularly preferably 0.3 or less. The "number of active groups of (D) the curing agent" in the resin composition means the value obtained by dividing the mass of the nonvolatile component of (D) the curing agent present in the resin composition by the active group equivalent weight. When the ratio of the active group / epoxy group is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and the mechanical strength and the moisture resistance of the cured product are generally particularly excellent.

[0105] The amount of (D) the curing agent is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, further preferably 1% by mass or more, preferably 20% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, particularly preferably 3% by mass or less, relative to 100% by mass of the nonvolatile component in the resin composition. When the amount of (D) the curing agent is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and the mechanical strength and the moisture resistance of the cured product are generally particularly excellent.

[0106] The amount of (D) the curing agent is preferably 0.1% by mass or more, more preferably 1% by mass or more, further preferably 2% by mass or more, preferably 30% by mass or less, more preferably 20% by mass or less, particularly preferably 10% by mass or less, relative to 100% by mass of the resin component in the resin composition. When the amount of (D) the curing agent is within the above range, the thermal conductivity and the adhesive strength of the cured product of the resin composition can be effectively improved, and the mechanical strength and the moisture resistance of the cured product are generally particularly excellent.

[0107] (E) Storage Stabilizer The resin composition according to the present embodiment can also contain (E) a storage stabilizer as an arbitrary component. The (E) storage stabilizer as the (E) component does not include substances corresponding to the above (A) to (D) components. Generally, (A) the liquid epoxy resin and (B) the first thiol compound have high reactivity, and by the (E) storage stabilizer, unintended reactions between (A) the liquid epoxy resin and (B) the first thiol compound can be suppressed, and thus the pot life of the resin composition can be improved. The (E) storage stabilizer can be used alone or in combination with two or more kinds.

[0108] As the (E) storage stabilizer, there can be mentioned, for example, a borate compound, a titanate compound, an aluminate compound, a zirconate compound, an isocyanate compound, a carboxylic acid, an anhydride, a mercapto organic acid, and the like.

[0109] As the borate compound, there can be mentioned, for example, trimethyl borate, triethyl borate (TEB), tri-n-propyl borate, triisopropyl borate, tri-n-butyl borate, triamyl borate, triallyl borate, trihexyl borate, tricyclohexyl borate, trioctyl borate, trinonyl borate, tridecyl borate, tridodecyl borate, trihexadecyl borate, trioctadecyl borate, tris(2-ethylhexyloxy)borane, bis(l,4,7,10-tetraoxaundecyl)(l,4,7,10,13-pentaoxa- tetradecyl)(l,4,7-trioxaundecyl)borane, tribenzyl borate, triphenyl borate, tri(o-tolyl)borate, tri(m-tolyl)borate, triethanolamine borate, and the like.

[0110] As the titanate compound, there can be mentioned, for example, tetraethyl titanate, tetrapropyl titanate, tetraisopropyl titanate, tetrabutyl titanate, tetraoctyl titanate, and the like.

[0111] As the aluminate compound, there can be mentioned, for example, triethyl aluminate, tripropyl aluminate, triisopropyl aluminate, tributyl aluminate, trioctyl aluminate, and the like.

[0112] As the zirconate compound, there can be mentioned, for example, tetraethyl zirconate, tetrapropyl zirconate, tetraisopropyl zirconate, tetrabutyl zirconate, and the like.

[0113] As the isocyanate compound, there can be mentioned, for example, n-butyl isocyanate, isopropyl isocyanate, 2-chloroethyl isocyanate, phenyl isocyanate, p-chlorophenyl isocyanate, benzyl isocyanate, hexamethylene diisocyanate, 2-ethylphenyl isocyanate, 2,6-dimethylphenyl isocyanate, toluene diisocyanate (e.g., 2,4-toluene diisocyanate, 2,6-toluene diisocyanate), 1,5-naphthalene diisocyanate, diphenylmethane-4,4'-diisocyanate, dimethyl diphenyl diisocyanate, isophorone diisocyanate, xylene diisocyanate, p-phenylene diisocyanate, bicycloheptane triisocyanate, and the like.

[0114] As the carboxylic acid, there can be mentioned, for example, formic acid, acetic acid, propionic acid, butyric acid, hexanoic acid, octanoic acid, and the like saturated aliphatic monobasic acids; acrylic acid, methacrylic acid, crotonic acid, and the like unsaturated aliphatic monobasic acids; monochloroacetic acid, dichloroacetic acid, and the like halogenated aliphatic acids; glycolic acid, lactic acid, and the like monobasic hydroxy acids; glyoxylic acid, malic acid, and the like aliphatic aldehyde acids and ketone acids; oxalic acid, malonic acid, succinic acid, maleic acid, and the like aliphatic polybasic acids; benzoic acid, halogenated benzoic acid, methylbenzoic acid, phenylacetic acid, cinnamic acid, mandelic acid, and the like aromatic monobasic acids; phthalic acid, trimesic acid, and the like aromatic polybasic acids.

[0115] As the acid anhydride, for example, aliphatic polybasic acid anhydrides such as succinic anhydride, dodecylsuccinic anhydride, maleic anhydride, an adduct of methylcyclopentadiene and maleic anhydride, hexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride; and aromatic polybasic acid anhydrides such as phthalic anhydride, trimesic anhydride, and pyromellitic dianhydride can be given.

[0116] As the mercapto organic acid, for example, mercapto aliphatic monocarboxylic acids such as mercaptoacetic acid, mercaptopropionic acid, mercaptobutyric acid, mercaptosuccinic acid, and dimercaptosuccinic acid; mercapto aliphatic monocarboxylic acids obtained by esterification of a hydroxy organic acid and a mercapto organic acid; and mercapto aromatic monocarboxylic acids such as mercaptobenzoic acid can be given.

[0117] As the (E) storage stabilizer, from the viewpoint of high versatility and safety and effective improvement of storage stability, a borate compound is preferred. Among them, triethyl borate, tri-n-propyl borate, triisopropyl borate, and tri-n-butyl borate are more preferred, and triethyl borate is further preferred.

[0118] The amount of the (E) storage stabilizer is preferably 0.01% by mass or more, more preferably 0.03% by mass or more, and further preferably 0.05% by mass or more, and is preferably 1% by mass or less, more preferably 0.5% by mass or less, and further preferably 0.3% by mass or less, relative to 100% by mass of the nonvolatile component in the resin composition.

[0119] The amount of the (E) storage stabilizer is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and further preferably 0.3% by mass or more, and is preferably 3% by mass or less, more preferably 2% by mass or less, and further preferably 1% by mass or less, relative to 100% by mass of the resin component in the resin composition.

[0120] (F) Curing Accelerator The resin composition according to the present embodiment can also contain a (F) curing accelerator as an arbitrary component. The (F) curing accelerator as the (F) component does not include substances corresponding to the above-mentioned (A) to (E) components. The (F) curing accelerator can accelerate the curing of the resin composition by acting as a catalyst in the reaction of the (A) liquid epoxy resin. One kind of the (F) curing accelerator can be used alone, or two or more kinds thereof can be used in combination.

[0121] As the (F) curing accelerator, a latent curing accelerator is preferably used. The latent curing accelerator generally does not contribute to the curing of the (A) liquid epoxy resin at normal temperature (25°C), and has a function of accelerating the curing of the (A) liquid epoxy resin upon heating.

[0122] The latent curing accelerator can be either a liquid latent curing accelerator or a solid dispersion type latent curing accelerator, but is more preferably a solid dispersion type latent curing accelerator. The liquid latent curing accelerator refers to a compound that is a liquid soluble in (A) liquid epoxy resin at ordinary temperature (25°C), functions as a curing accelerator for (A) liquid epoxy resin by heating. On the other hand, the solid dispersion type latent curing accelerator refers to a compound that is a solid insoluble in (A) liquid epoxy resin at ordinary temperature (25°C), becomes soluble in (A) liquid epoxy resin by heating, and functions as a curing accelerator for (A) liquid epoxy resin.

[0123] As the solid dispersion type latent curing accelerator, for example, an imidazole compound that is a solid at ordinary temperature (25°C) and a solid dispersion type amine adduct-based latent curing accelerator can be given.

[0124] As the imidazole compound that is a solid at ordinary temperature (25°C), for example, 2-heptadecyl imidazole, 2-phenyl-4,5-dihydroxymethyl imidazole, 2-undecyl imidazole, 2-phenyl-4-methyl-5-hydroxymethyl imidazole, 2-phenyl-4-benzyl-5-hydroxymethyl imidazole, 2,4-diamino-6-[2-(2-methyl-l-imidazolyl)ethyl]-l,3,5-triazine, 2,4-diamino-6-[2-(2-methyl-l-imidazolyl)ethyl]-l,3,5-triazine / isocyanuric acid adduct, 2-methyl imidazole, 2-phenyl imidazole, 2-phenyl-4-methyl imidazole, l-cyanoethyl-2-phenyl imidazole, l-cyanoethyl-2-methyl imidazole, l-cyanoethyl-2-phenyl imidazole, N-(2-methyl imidazolyl-l-ethyl)urea, and the like can be given.

[0125] As suitable examples of the solid dispersion type amine adduct-based latent curing accelerator, an amine epoxy adduct-based latent curing accelerator, a urea adduct-based latent curing accelerator of an amine compound, and a compound obtained by addition reaction of an isocyanate compound with a hydroxyl group of an epoxy adduct can be given. Among them, the amine epoxy adduct-based latent curing accelerator is preferred.

[0126] As the epoxy compound which can be used as one of the raw materials for producing the solid dispersion amine adduct-based latent curing accelerator, there can be mentioned, for example, polyglycidyl ethers obtained by reacting polyhydric phenols (bisphenol A, bisphenol F, catechol, resorcinol, etc.) or polyhydric alcohols (glycerol, polyethylene glycol, etc.) with epichlorohydrin; glycidyl ether esters obtained by reacting hydroxyl carboxylic acids such as p-hydroxybenzoic acid, β-hydroxynaphthoic acid, etc. with epichlorohydrin; polyglycidyl esters obtained by reacting polycarboxylic acids such as phthalic acid, terephthalic acid, etc. with epichlorohydrin; glycidyl amine compounds obtained by reacting 4,4'-diaminodiphenylmethane or m-aminophenol, etc. with epichlorohydrin; multifunctional epoxy compounds such as epoxidized phenol novolak resin, epoxidized cresol novolak resin, epoxidized polyolefin, etc.; monofunctional epoxy compounds such as butyl glycidyl ether, phenyl glycidyl ether, glycidyl methacrylate, etc.

[0127] As the amine compound which can be used as one of the raw materials for producing the solid dispersion amine adduct-based latent curing accelerator, there can be mentioned a compound having one or more active hydrogens which can be subjected to an addition reaction with an epoxy group in the molecule, and at least one or more functional groups selected from primary amino groups, secondary amino groups and tertiary amino groups in the molecule. As the amine compound, there can be mentioned, for example, aliphatic amine compounds such as diethylenetriamine, triethylenetetramine, n-propylamine, 2-hydroxyethylaminopropylamine, cyclohexylamine, 4,4'-diamino-dicyclohexylmethane, etc.; aromatic amine compounds such as 4,4'-diaminodiphenylmethane, 2-methylaniline, etc.; nitrogen-containing heterocyclic compounds such as 2-ethyl-4-methylimidazole, 2-ethyl-4-methylimidazoline, 2,4-dimethylimidazoline, piperidine, piperazine, etc.

[0128] Among the above-mentioned amine compounds, an amine compound having a tertiary amino group in the molecule is a raw material that provides a latent curing accelerator having excellent curing acceleration ability. As the amine compound having a tertiary amino group in the molecule, for example, a primary amine or a secondary amine having a tertiary amino group in the molecule; an alcohol, a phenol, a mercaptan, a carboxylic acid, and a hydrazine having a tertiary amino group in the molecule can be given. As the primary amine or the secondary amine having a tertiary amino group in the molecule, for example, dimethylaminopropylamine, diethylaminopropylamine, di-n-propylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, N-methylpiperazine, and the like amine compounds; 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, and the like imidazole compounds can be given. In addition, as the alcohol, the phenol, the mercaptan, the carboxylic acid, and the hydrazine having a tertiary amino group in the molecule, for example, 2-dimethylaminoethanol, 1-methyl-2-dimethylaminoethanol, 1-phenoxy-methyl-2-dimethylaminoethanol, 2-diethylaminoethanol, 1-butoxy-methyl-2-dimethylaminoethanol, 1-(2-hydroxy-3-phenoxypropyl)-2-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-ethyl-4-methylimidazole, 1-(2-hydroxy-3-butoxypropyl)-2-methylimidazole, 1-(2-hydroxy-3-butoxypropyl)-2-ethyl-4-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-phenylimidazoline, 1-(2-hydroxy-3-butoxypropyl)-2-methylimidazoline, 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, N-β-hydroxyethylmorpholine, 2-dimethylaminoethanethiol, 2-mercaptopyridine, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 4-mercaptopyridine, N,N-dimethylaminobenzoic acid, N,N-dimethylglycine, nicotinic acid, isonicotinic acid, methylpyridinic acid, N,N-dimethylglycine hydrazide, N,N-dimethylpropionic acid hydrazide, nicotinic acid hydrazide, isonicotinic acid hydrazide can be given.

[0129] When the latent curing accelerator is produced by causing the addition reaction of the epoxy compound and the amine compound, an active hydrogen compound having two or more active hydrogens in the molecule can be further reacted. As such an active hydrogen compound, for example, a polyphenol such as bisphenol A, bisphenol F, bisphenol S, hydroquinone, catechol, resorcinol, pyrogallol, phenol novolak resin, and the like; a polyol such as trimethylolpropane, and the like; a polycarboxylic acid such as adipic acid, phthalic acid, and the like; 1,2-dimercaptoethane, 2-mercaptoethanol, 1-mercapto-3-phenoxy-2-propanol, mercaptoacetic acid, anthranilic acid, lactic acid, and the like can be given.

[0130] As the isocyanate compound used as one of the raw materials for producing the solid dispersion amine adduct-based latent curing accelerator, monofunctional isocyanate compounds such as n-butyl isocyanate, isopropyl isocyanate, phenyl isocyanate, benzyl isocyanate, and the like; polyfunctional isocyanate compounds such as hexamethylene diisocyanate, toluene diisocyanate, 1,5-naphthalene diisocyanate, diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, xylene diisocyanate, p-phenylene diisocyanate, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate, and the like; compounds containing terminal isocyanate groups obtained by the reaction of these polyfunctional isocyanate compounds with active hydrogen compounds, and the like can be given. As specific examples of the compounds containing terminal isocyanate groups, addition compounds having terminal isocyanate groups obtained by the reaction of toluene diisocyanate with trimethylolpropane, addition compounds having terminal isocyanate groups obtained by the reaction of toluene diisocyanate with pentaerythritol, and the like can be given.

[0131] As the urea compound used as one of the raw materials for producing the solid dispersion amine adduct-based latent curing accelerator, urea, thiourea, and the like can be given.

[0132] The above-described solid dispersion amine adduct-based latent curing accelerator can be produced, for example, by a method in which the above-described raw materials are mixed, allowed to react at a temperature of normal temperature to 200°C, and then pulverized after solidification by cooling, or a method in which the above-described raw materials are allowed to react in a solvent such as methyl ethyl ketone, dioxane, tetrahydrofuran, and the like, and then the solid component is pulverized after desolventization.

[0133] As commercially available products of the solid dispersion amine adduct-based latent curing accelerator, "Ajicure PN-FJ" (manufactured by Ajinomoto Fine-Techno Co., Ltd.), "Ajicure PN-23" (manufactured by Ajinomoto Fine-Techno Co., Ltd.), "Ajicure PN-H" (manufactured by Ajinomoto Fine-Techno Co., Ltd.), "Hardener X-3661S" (manufactured by A.C.R. Co.), "Hardener X-3670S" (manufactured by A.C.R. Co.), "FXR-1081" (manufactured by T&K TOKA Corporation), "Fujicure FXR-1000" (manufactured by T&K TOKA Corporation), "Fujicure FXR-1030" (manufactured by T&K TOKA Corporation), "NOVACURE HX-3721" (manufactured by Asahi Kasei Co.), "HX-3722" (manufactured by Asahi Kasei Co.), "NOVACURE HX-3742" (manufactured by Asahi Kasei Co.), and the like can be given.

[0134] The amount of the (F) curing accelerator is preferably 0.01% by mass or more, more preferably 0.1% by mass or more, particularly preferably 1.0% by mass or more, relative to 100% by mass of the nonvolatile components in the resin composition, and is preferably 10% by mass or less, more preferably 5% by mass or less, further preferably 3% by mass or less.

[0135] The amount of the (F) curing accelerator is preferably 0.1% by mass or more, more preferably 1.0% by mass or more, further preferably 2.0% by mass or more, relative to 100% by mass of the resin components in the resin composition, and is preferably 20% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less.

[0136] <(G) Optional Additive> The resin composition according to the present embodiment can further contain, as an optional nonvolatile component, a (G) optional additive. The (G) optional additive as the (G) component does not include substances corresponding to the above-mentioned (A) to (F) components. As the (G) optional additive, for example, an epoxy resin other than the (A) liquid epoxy resin; a thermoplastic resin; a polymerization initiator; an organic metal compound such as an organic copper compound, an organic zinc compound, and an organic cobalt compound; a colorant such as phthalocyanine blue, phthalocyanine green, iodine green, diazonium yellow, crystal violet, titanium oxide, and carbon black; a polymerization inhibitor such as hydroquinone, catechol, pyrogallol, and phenothiazine; a leveling agent such as a silicone-based leveling agent, an acrylic polymer-based leveling agent, and a fluorine-based leveling agent; a thickening agent such as BENTON and montmorillonite; a defoaming agent such as a silicone-based defoaming agent, an acrylic-based defoaming agent, a fluorine-based defoaming agent, and a vinyl resin-based defoaming agent; an ultraviolet absorber such as a benzotriazole-based ultraviolet absorber; an adhesion improver such as a urea silane; an adhesion imparting agent such as a triazole-based adhesion imparting agent, a tetrazole-based adhesion imparting agent, and a triazine-based adhesion imparting agent; an antioxidant such as a hindered phenol-based antioxidant; a fluorescent brightener such as a stilbene derivative; a surfactant such as a fluorine-based surfactant and a silicone-based surfactant; a flame retardant such as a phosphorus-based flame retardant (for example, a phosphate compound, a phosphazene compound, a hypophosphorous acid compound, and red phosphorus), a nitrogen-based flame retardant (for example, melamine sulfate), a halogen-based flame retardant, and an inorganic-based flame retardant (for example, antimony trioxide); and the like can be exemplified. The (G) optional additive can be used alone or in combination of two or more.

[0137] <(H) Solvent> The resin composition according to the present embodiment can further contain, as an optional volatile component, a (H) solvent in combination with the above-mentioned (A) to (G) components as the nonvolatile components. The solvent can be used alone or in combination of two or more at an arbitrary ratio.

[0138] As the solvent (H), an organic solvent is generally used. As the organic solvent, there can be mentioned, for example, ketone-based solvents such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, cyclohexanone, and the like; ester-based solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, γ-butyrolactone, and the like; ether-based solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, diphenyl ether, anisole, and the like; alcohol-based solvents such as methanol, ethanol, propanol, butanol, ethylene glycol, and the like; ether ester-based solvents such as 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, methyl methoxypropionate, and the like; ester alcohol-based solvents such as methyl lactate, ethyl lactate, methyl 2-hydroxyisobutyrate, and the like; ether alcohol-based solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, diethylene glycol monobutyl ether (butyl carbitol), and the like; amide-based solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and the like; sulfoxide-based solvents such as dimethyl sulfoxide, and the like; nitrile-based solvents such as acetonitrile, propionitrile, and the like; aliphatic hydrocarbon-based solvents such as hexane, cyclopentane, cyclohexane, methylcyclohexane, and the like; aromatic hydrocarbon-based solvents such as benzene, toluene, xylene, ethylbenzene, mesitylene, and the like.

[0139] The amount of the solvent (H) is preferably 10% by mass or less, more preferably 5% by mass or less, further preferably 3% by mass or less, 1% by mass or less, 0.5% by mass or less, 0.1% by mass or less, or 0.01% by mass or less, relative to 100% by mass of the nonvolatile components in the resin composition. Among them, the amount of the solvent (H) is particularly preferably 0% by mass. That is, the resin composition according to the present embodiment is particularly preferably free of the solvent (H).

[0140] <Properties of the resin composition and the cured product thereof> The resin composition according to the present embodiment can be in a solid state or in a liquid state. In addition, the resin composition in a liquid state can be in a paste shape free of the solvent (H) or containing only a small amount of the solvent (H), or can be in a varnish shape containing a large amount of the solvent (H).

[0141] By curing the resin composition according to the present embodiment, a cured product of the resin composition can be obtained. Generally, since heat is applied when the resin composition is cured, among the components contained in the resin composition, volatile components such as the solvent (H) can be volatilized by the heat at the time of curing. Therefore, the cured product obtained by curing the resin composition can contain nonvolatile components such as the components (A) to (G) or reaction products thereof.

[0142] The cured product of the resin composition can have high thermal conductivity. Generally, the cured product can have a high thermal conductivity coefficient. In one example, the thermal conductivity coefficient of the cured product obtained by curing the resin composition at 80°C for 60 minutes is preferably in the range of 0.5 W / mK or more, more preferably 1.0 W / mK or more, and further preferably 1.2 W / mK or more. The upper limit is generally 10 W / mK or less, for example, 8 W / mK or less or 6 W / mK or less. In addition, the cured product contained in an electronic component or a semiconductor device can also have a thermal conductivity coefficient in the above range.

[0143] The thermal conductivity coefficient of the cured product can be measured by a hot disk method using a thermal physical property measuring device in a constant temperature environment at a measurement temperature of 25°C and a relative humidity of 40% RH. The specific measurement method can be the method described later in the examples.

[0144] The cured product of the resin composition can have high adhesive strength. Generally, the cured product can have high shear adhesive strength. In particular, the cured product can exert high adhesive strength on a difficult-to-adhere material (for example, nickel, liquid crystal polymer, or the like) for which high adhesive strength is difficult to obtain with a conventional resin composition.

[0145] In one example, two test pieces made of nickel are adhered via the resin composition, and the resin composition is cured to obtain a layered test sample having test pieces / cured product / test pieces in this order. Using this layered test sample, a tensile shear adhesive strength measurement test is performed in accordance with JIS-K-6850. The shear adhesive strength measured in this measurement test is generally in the range of 10 MPa or more, preferably 12 MPa or more, and further preferably 14 MPa or more. The upper limit is more preferably higher, for example, 30 MPa or less or 20 MPa or less.

[0146] In another example, two test pieces made of liquid crystal polymer are adhered via the resin composition, and the resin composition is cured to obtain a layered test sample having test pieces / cured product / test pieces in this order. Using this layered test sample, a tensile shear adhesive strength measurement test is performed in accordance with JIS-K-6850. The shear adhesive strength measured in this measurement test is generally in the range of 4.0 MPa or more, preferably 4.5 MPa or more, and further preferably 5.0 MPa or more. The upper limit is more preferably higher, for example, 20 MPa or less or 10 MPa or less.

[0147] The shear bond strength of the cured product can be measured under the measurement conditions of temperature 25°C, relative humidity 60%, and tensile speed 5 mm / min, by conducting the measurement test according to JIS-K-6850 as described above. In addition, the measurement can be conducted using a laminated sample containing a cured product obtained by curing the resin composition under conditions of 80°C for 60 minutes. The specific measurement method can employ the method described later in the examples.

[0148] The cured product of the resin composition can generally have excellent mechanical properties. For example, the cured product preferably has a low elastic modulus, and thus has excellent flexibility and toughness. In one example, the tensile elastic modulus of the cured product obtained by curing the resin composition under conditions of 80°C for 60 minutes is preferably in the range of 5,000 MPa or less, more preferably 3,000 MPa or less, and further preferably 2,000 MPa or less. The lower limit is preferably 10 MPa or more, and can also be 100 MPa or more or 200 MPa or more. In addition, the cured product contained in an electronic component or a semiconductor device can also have a tensile elastic modulus in the above range.

[0149] The tensile elastic modulus of the cured product can be measured by a tensile test under conditions of temperature 25°C, humidity 60%, and tensile speed 5 mm / min. The specific measurement method can employ the method described later in the examples.

[0150] In addition, for example, the cured product preferably has a high elongation at break. In one example, the elongation at break of the cured product obtained by curing the resin composition under conditions of 80°C for 60 minutes is preferably in the range of 3% or more, more preferably 10% or more, and further preferably 15% or more. The upper limit is more preferably larger, and can be, for example, 300% or less, 290% or less, or 280% or less. In addition, the cured product contained in an electronic component or a semiconductor device can also have an elongation at break in the above range.

[0151] The elongation at break of the cured product can be measured by a tensile test under conditions of temperature 25°C, humidity 60%, and tensile speed 5 mm / min. The specific measurement method can employ the method described later in the examples.

[0152] The cured product of the resin composition can generally have excellent moisture resistance. For example, the cured product preferably has a small decrease in the bond strength resulting from a storage test in which the cured product is stored in a high-temperature high-humidity environment. In one example, in the case where the storage test in which the sample is left in an environment of temperature 85°C and relative humidity 85% RH for 250 hours is performed, the strength retention rate is preferably in the range of 60% or more, more preferably 80% or more, and generally 100% or less.

[0153] The strength retention rate can use the shear bond strength S measured before the storage testA and the shear bond strength S measured after the storage test B The shear bond strength is calculated using the following formula (M1). Additionally, the shear bond strength can be determined according to JIS-K-6850 using a laminated specimen with appropriate test pieces (e.g., mild steel sheet (JIS G3141, SPCC)). This determination can be performed using a laminated specimen containing a cured product obtained by curing the resin composition at 80°C for 60 minutes. Specific determination methods can be employed as described later in the examples.

[0154] Strength retention rate (%) = S B / S A ×100 (M1) <Method for manufacturing resin composition> The resin composition according to this embodiment can be manufactured, for example, by mixing components that may be contained in the resin composition. Some or all of the above components may be mixed simultaneously, or they may be mixed sequentially. During the mixing of each component, the temperature can be appropriately set, so heating and / or cooling can be performed temporarily or continuously. Furthermore, stirring or agitation can be performed during the mixing of each component.

[0155] <Uses of Resin Compositions> The resin composition described in this embodiment provides a cured product with both excellent thermal conductivity and adhesive strength. Taking advantage of these superior properties, this resin composition is preferably used as an adhesive resin composition requiring both thermal conductivity and adhesive strength.

[0156] Examples of preferred uses of the resin composition include resin compositions used for bonding heat sinks and electronic components in electronic components such as semiconductor modules. As a specific example, the resin composition can also be used as the aforementioned bonding resin composition in a method for manufacturing a camera module that includes bonding one or more of a circuit board, electronic components, and a heat sink. Examples of electronic components include semiconductor chips, power semiconductors, and LED-PKGs.

[0157] Furthermore, as an example of a preferred use of the resin composition, one can cite a resin composition used in semiconductor devices for bonding substrates and electronic components. As a specific example, the resin composition described in this embodiment can also be used as the aforementioned bonding resin composition in a method for manufacturing a semiconductor device that includes bonding substrates such as circuit boards, frames, and housings to electronic components such as camera modules.

[0158] Generally, the cured product of a resin composition has insulating properties. Therefore, utilizing this insulating property, the aforementioned resin composition can also be used as a resin composition for forming a cured layer in a circuit board. For example, as the cured layer, an insulating layer and a sealing layer can also be formed. Here, examples of circuit boards include printed wiring boards, semiconductor chip packages, etc., but are not limited to these.

[0159] <Resin Sheets> One embodiment of the present invention relates to a resin sheet comprising: a support body and a resin composition layer formed on the support body. The resin composition layer comprises the resin composition described above, and preferably comprises only the resin composition described above.

[0160] From the viewpoint of thinness, the thickness of the resin composition layer in the resin sheet is preferably 200 μm or less, more preferably 150 μm or less, and even more preferably 100 μm or less. The lower limit of the thickness of the resin composition layer can be, for example, 1 μm or more, 3 μm or more, 5 μm or more, etc.

[0161] Examples of supports include: films of plastic materials, metal foils, and release paper, with films of plastic materials and metal foils being preferred.

[0162] When using a film made of plastic material as a support, examples of plastic materials include: polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylics such as polycarbonate (PC), polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, and polyimide. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, and inexpensive polyethylene terephthalate is particularly preferred.

[0163] When using metal foil as a support, examples of metal foils include copper foil and aluminum foil, with copper foil being preferred. As copper foil, foils containing a single metal such as copper can be used, or foils containing alloys of copper with other metals (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) can be used.

[0164] Surface treatments such as matte finish, corona treatment, and antistatic treatment can be applied to the surface of the support that is bonded to the resin composition layer.

[0165] As a support, a support with a release layer can be used on the surface that bonds to the resin composition layer. Examples of release agents used in the release layer of the support with a release layer include, for example, one or more release agents selected from alkyd-based, polyolefin-based, polyurethane-based, and silicone-based release agents. Commercially available products can be used as the support with the release layer, such as PET films having a release layer primarily composed of a silicone-based or alkyd resin-based release agent, such as LINTEC's "PET501010", "SK-1", "AL-5", and "AL-7"; Toray's "Lumirror T60"; Teijin's "Purex"; and UNITIKA's "Unipeel".

[0166] There is no particular limitation on the thickness of the support body, but it is preferably 1 μm or more, more preferably 5 μm or more, even more preferably 10 μm or more, preferably 75 μm or less, more preferably 60 μm or less, and even more preferably 50 μm or less. When using a support body with a release layer, it is preferable that the overall thickness of the support body with the release layer is within the above-mentioned range.

[0167] The resin sheet may have any components as needed. For example, the resin sheet may have a protective film that protects the resin composition layer. The protective film is usually provided on the side of the resin composition layer that is not bonded to the support (i.e., the side opposite to the support). There is no particular limitation on the thickness of the protective film, for example, it is 1 μm to 40 μm. With the protective film, dust adhesion to the surface of the resin composition layer and damage to the surface of the resin composition layer can be prevented.

[0168] Resin sheets can be used, for example, to form resin composition layers on suitable substrates. Methods for forming resin composition layers using resin sheets typically involve laminating the resin sheet and a substrate. The lamination of the resin sheet and substrate is performed in a manner that the resin composition layer of the resin sheet is bonded to the substrate. This lamination can also be performed, for example, by heating and pressing the resin sheet onto the substrate from the support side. As a specific example, the resin sheet and substrate can also be laminated, and the support can be peeled off as needed to form the resin composition layer on the substrate.

[0169] Resin sheets can be manufactured, for example, by forming a resin composition layer on a support. As a specific example, resin sheets can also be manufactured by coating a liquid resin composition onto a support and then drying it as needed to form a resin composition layer.

[0170] The resin composition can be coated using a coating apparatus such as a die coater. Drying can be performed by methods such as heating or blowing hot air. There are no particular limitations on the drying conditions; drying is generally carried out when the solvent content in the resin composition layer is typically 10% by mass or less, preferably 5% by mass or less. While the specific conditions may vary depending on the boiling point of the solvent, in the case of a resin composition containing, for example, 30% to 60% by mass of solvent, a resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

[0171] The manufactured resin sheets can be wound into rolls for storage. When the resin sheet has a protective film, it can usually be used by peeling off the protective film.

[0172] <Electronic Components> The above-described resin composition exhibits excellent adhesive strength and is therefore preferably used as an adhesive in electronic components such as semiconductor modules. Generally, electronic components comprise electronic parts and constituent elements other than those electronic parts. Therefore, the above-described resin composition can also be used to bond electronic parts to constituent elements.

[0173] From the viewpoint of effectively utilizing the high thermal conductivity of the cured resin composition, the resin composition is preferably used to bond electronic components and heat sinks. Thus, an electronic component using the resin composition in bonding electronic components to a heat sink includes, for example, a heat sink, a cured resin composition disposed on the heat sink, and electronic components mounted on the cured resin composition. In this electronic component, heat generated by the electronic component is efficiently transferred to the heat sink through the cured resin, thereby enabling efficient heat dissipation from the electronic component.

[0174] The electronic component can be manufactured, for example, by a method comprising: a step of coating a resin composition onto one or both of the electronic component and the heat sink; a step of bonding the electronic component and the heat sink via the resin composition; and a step of curing the resin composition. The coating of the resin composition can also be performed, for example, by the method described in the method for manufacturing resin sheets. Alternatively, the resin composition can be applied using a coating apparatus such as a syringe or dispenser, and pressure can be applied as needed to achieve a uniform thickness.

[0175] The curing of resin compositions is typically performed by heat curing. The heat curing conditions for the resin composition layer can vary depending on the type of resin composition. For example, the curing temperature is preferably 50°C to 240°C, more preferably 60°C to 220°C, and even more preferably 70°C to 210°C. Furthermore, the curing time is preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes. Additionally, the process of curing the resin composition may include preheating the resin composition at a temperature below the curing temperature before heat curing.

[0176] Examples of such electronic components include modules containing semiconductor chips (e.g., camera modules) and semiconductor chip packages, but are not limited to these.

[0177] Semiconductor Devices One embodiment of the present invention relates to a semiconductor device comprising a cured product of the above-described resin composition. Examples of such semiconductor devices include semiconductor devices incorporating the above-described electronic components.

[0178] Furthermore, in semiconductor devices, resin compositions can also be used to bond the constituent elements of the semiconductor device. For example, a semiconductor device may include a substrate, a cured resin composition disposed on the substrate, and electronic components or electronic elements mounted on the cured composition. Examples of substrates include circuit boards, heat sinks, and frames. In the semiconductor device, the electronic components or electronic elements are bonded to the substrate by the cured resin composition. From the viewpoint of effectively utilizing the high adhesive strength to materials with poor adhesion, such as nickel and liquid crystal polymers, the bonding surface of the substrate (the surface that bonds with the cured composition) can also be formed from a material with poor adhesion.

[0179] Specific examples of the aforementioned semiconductor devices include various semiconductor devices supplied to electrical products (such as computers, mobile phones, smartphones, tablet computers, wearable devices, digital cameras, medical devices, and televisions) and vehicles (such as motorcycles, automobiles, trams, ships, and airplanes). Example

[0180] Hereinafter, embodiments of the present invention will be specifically described. However, the present invention is not limited to the embodiments described below. In the following description, unless otherwise specified, "parts" and "%" are based on mass. In addition, unless otherwise specified, the operations described below are performed in an atmospheric environment at normal temperature and pressure (23°C 1 atm).

[0181] <Determination Methods for High Performance Liquid Chromatography and Mass Spectrometry (LC / MS)> The sample was diluted with tetrahydrofuran (THF) to 1 mg / mL and determined by high-speed liquid chromatography and mass spectrometry (LC / MS) under the following conditions.

[0182] High Performance Liquid Chromatography (HPLC): ACQUITY UPLC (manufactured by Waters Corporation, Japan) Mass spectrometry (MS): SQ Detector2 (manufactured by WATERS Corporation, Japan) Column: ACQUITY UPLC BEH C8 1.7um, 2.1mm×50mm (manufactured by WATERS Corporation, Japan) Mobile phase A: 2 mmol ammonium acetate aqueous solution Mobile phase B: 2-propanol / acetonitrile (50:50) Mobile phase mixing time and mixing ratio (A%): 0–0.5 minutes (95%) → 1 minute–8.5 minutes (75%) → 9–11 minutes (5%) → 11.1 minutes (95%) → 13 minutes (95%) Flow rate: 0.30 mL / min Analysis time: 13 minutes Column temperature: 40℃, ion mode: ESI (electrospray ionization) positive ion Ion polarity: Positive ion detection mode Desolventizing gas flow rate: 700 L / hr, 250 °C Conical orifice gas: 70L / hr Ion source heater: 150℃.

[0183] <NMR Measurement Methods> NMR data for each synthesized sample were collected using a JEOL LA-500 (manufactured by JEOL Corporation).

[0184] <Synthetic Example 1. Synthesis of Thiol Compound (1)> (1) Synthesis of aliphatic skeleton diallyl compound (1): In a 2-liter four-necked round-bottom flask equipped with a stirrer, thermometer, capacitor, dropping funnel, and Dean-Stark water separator, 140.9 g (1.05 mol) of 2-allylphenol (reagent), 108.0 g (0.5 mol) of 1,4-dibromobutane (reagent), 3.1 g of tetrabutylammonium bromide as a phase transfer catalyst, and 300 g of methyl isobutyl ketone (MIBK) as a reaction solvent were added. The mixture was heated to 100°C and maintained for 30 minutes to allow complete dissolution. 175 g (1.5 mol) of 48% KOH aqueous solution was added dropwise to the resulting solution over 1 hour. Water and MIBK obtained by azeotropic distillation of the added KOH aqueous solution were separated into water and MIBK respectively in the Dean-Stark water separator, with only MIBK returned to the reaction system to continue the reaction. Subsequently, only MIBK was returned to the system at 118°C to remove water by distillation, while the reaction continued for 6 hours. Then, the temperature was lowered to 60°C, 100g of distilled water was added and the mixture was allowed to stand, discarding the lower brine layer as a byproduct. Next, 100g of distilled water and an appropriate amount of sodium dihydrogen phosphate for neutralization were added, and the mixture was allowed to stand and separate, discarding the lower brine layer as a byproduct. Then, an equal volume of distilled water was added, and the mixture was washed twice for purification. The solution was then heated to 118°C for azeotropic dehydration. The resulting solution was filtered using filter paper No. 5C (manufactured by Kiriyama Corporation) and a Kiriyama funnel (manufactured by Kiriyama Corporation) to remove impurities. MIBK and unreacted 2-allylphenol were then distilled under reduced pressure at a maximum temperature of 180°C to obtain 145g of liquid resin. The obtained liquid resin was analyzed according to the LC / MS method described above. As a result, spectral peaks were detected at m / z = 323 for the proton adduct and m / z = 340 for the ammonium adduct. Based on the analytical data, the obtained liquid resin was confirmed to be a diallyl compound (1) as shown in the following formula (c-1).

[0185] [Chemical Formula 6] .

[0186] (2) Synthesis of thiol compound (1): In a 1L four-necked flask, diallyl compound (1) (100g, 0.31mol, 1.0eq), thioacetic acid (51.9g, 0.682mol, 2.2eq), toluene (360mL), and azobisisobutyronitrile (AIBN, 5.09g, 0.031mol, 0.1eq) were added, and the mixture was reacted at 80°C for 4 hours. The resulting reactants were concentrated under reduced pressure to remove toluene, and then crystallized in methanol (500g). The crystals were dried under vacuum, and 110.36g of the dried crystals were recovered. In a 3L four-necked flask, the recovered dried crystals (110.36g) and 32% NaOH (550g) were added, and the mixture was reacted at 80°C for 2 hours. After neutralization with 1N HCl (380mL), the organic layer was separated and washed with water. Toluene was removed from the water-washed organic layer by vacuum concentration to obtain 89.0 g of the target thiol compound (1) (yield 74%). The obtained thiol compound (1) was analyzed according to the LC / MS method described above. As a result, spectral peaks were detected corresponding to the proton adduct at m / z = 391 and the ammonium adduct at m / z = 408. Based on these analytical data and... Figure 1 The NMR spectra shown confirmed that the obtained thiol compound (1) has the structure shown in formula (I-1).

[0187] [Chemical Formula 7] .

[0188] <Synthetic Example 2. Synthesis of Thiol Compound (2)> (1) Synthesis of aliphatic skeleton diallyl compound (2): Except for replacing 108.0 g (0.5 mol) of 1,4-dibromobutane (reagent) with 150.0 g (0.5 mol) of 1,10-dibromodecane, 165 g of liquid resin was obtained by the same method as in step (1) of Synthesis Example 1. The obtained liquid resin was analyzed according to the LC / MS determination method described above. As a result, spectral peaks were detected corresponding to the proton adduct at m / z = 407 and the ammonium adduct at m / z = 424. Based on this analytical data, the obtained liquid resin was confirmed to be the diallyl compound (2) shown in formula (c-2) below.

[0189] [Chemical Formula 8] .

[0190] (2) Synthesis of thiol compound (2): Except that 100 g (0.31 mol) of diallyl compound (1) was replaced with 125.9 g (0.31 mol) of diallyl compound (2) synthesized in step (1) of Example 2, 109 g of the target thiol compound (2) was obtained by the same method as in step (2) of Example 1. The obtained thiol compound (2) was analyzed according to the LC / MS determination method described above. As a result, spectral peaks were detected corresponding to the proton adduct at m / z = 475 and the ammonium adduct at m / z = 492. Based on this analytical data and Figure 2 The NMR spectra shown confirmed that the obtained thiol compound (2) has the structure shown in formula (I-3).

[0191] [Chemical Formula 9] .

[0192] <Examples 1-12 and Comparative Examples 1-4> (Preparation of thermally conductive resin composition) The components were mixed according to the formulations shown in Tables 1 to 4 to prepare a resin composition. It should be noted that the mixing amounts of each component in Tables 1 to 4 are in parts by mass. Specifically, the amounts of material shown in the tables were measured into a dedicated plastic container. Then, the mixture was thoroughly mixed at 2000 rpm at room temperature using a rotary / revolutionary vacuum mixer (THINKY Corporation "Awatori Rentaro ARE-310"), followed by degassing for 1 minute to obtain the target resin composition.

[0193] The details of the materials used are shown below.

[0194] <(A) Liquid epoxy resin> "ZX1059": Bisphenol type epoxy resin (a 1:1 mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin), manufactured by Nippon Steel Chemical & Materials Co., Ltd., with an epoxy equivalent of approximately 165 g / eq., a viscosity of 2250 mPa·s, and a density of 1.18 g / cm³. 3 .

[0195] "HP-820": Tert-butylcatechol type epoxy resin, manufactured by DIC Corporation, with an epoxy equivalent of approximately 214 g / eq., a viscosity of 1500 mPa·s, and a density of 1.2 g / cm³. 3 .

[0196] <(B) Inorganic filler materials> "AS-20": Manufactured by Resonac, this alumina filler has an average particle size of 22 μm, a thermal conductivity of 20 W / mK to 30 W / mK, and a specific surface area of ​​0.6 m². 2 / g, density 3.9g / cm³ 3 .

[0197] "SSC-A15": Manufactured by Shinano Electric Refining Co., Ltd., a silicon carbide filler with an average particle size of 15.0 μm, a thermal conductivity of 270 W / mK, and a specific surface area of ​​0.3 m². 2 / g~0.5m 2 / g, density 3.2g / cm³ 3 .

[0198] "AlN-1501": Manufactured by Resonac, this aluminum nitride filler has an average particle size of 13 μm, a thermal conductivity of 140 W / mK-250 W / mK, and a specific surface area of ​​0.9 m². 2 / g, density 3.2g / cm³ 3 .

[0199] "SO-C5": A silica filler manufactured by ADMATECHS, with an average particle size of 1.3μm to 1.7μm, a thermal conductivity of 2W / mK, and a specific surface area of ​​3.0m². 2 / g~5.0m 2 / g, density 2.2g / cm³ 3 .

[0200] <(C) First Thiol Compound> "Thiol compound (1)": Thiol compound (1) synthesized in Synthetic Example 1, 3,3'-((butane-1,4-dimethyldioxy)bis(2,1-phenylene))bis(propane-1-thiol), compound of formula (I-1), mercapto equivalent 195 g / eq., density 1.2 g / cm³ 3 .

[0201] "Thiol compound (2)": Thiol compound (2) synthesized in Synthetic Example 2, 3,3'-((decane-1,10-dimethyldioxy)bis(2,1-phenylene))bis(propane-1-thiol), compound of formula (I-3), mercapto equivalent 245 g / eq., density 1.2 g / cm³ 3 .

[0202] <(D) Curing Agent> "TMPIC": Tris(3-mercaptopropyl) isocyanurate, manufactured by Ajinomoto Fine Chemicals Co., Ltd., mercapto equivalent 117 g / eq., density 1.2 g / cm³ 3 .

[0203] “C3TSG”: Tetrahydro-1,3,4,6-Tetra(3-mercaptopropyl)-imidazo[4,5-d]imidazo-2,5(1H,3H)-dione, manufactured by Shikoku Chemical Industry Co., Ltd., with a mercapto equivalent of 114 g / eq. and a density of 1.28 g / cm³. 3 .

[0204] <(E) Preservative Stabilizer> "TEB": Triethyl borate, manufactured by Tokyo Chemical Industry Co., Ltd., density 0.86 g / cm³ 3 .

[0205] <(F) Curing Accelerator> "FXR-1081": Modified aliphatic polyamine resin, manufactured by T&K TOKA, density 1.1 g / cm³ 3 .

[0206] <Evaluation Test of Shear Bond Strength> Prepare two flat test pieces and wipe away any oil residue using waste cotton yarn moistened with acetone. Apply a resin composition evenly to the flat surface of each test piece to a thickness of approximately 1 mm. Place the two test pieces together with the resin-coated surfaces overlapping each other by approximately 12 mm and press them together with two clamps. At this point, some of the resin composition will seep out from between the two test pieces; immediately wipe away this seeped resin composition with waste cotton yarn. Arrange the test pieces evenly in an oven and heat at 80°C for 60 minutes to cure the resin composition. Thus, the two test pieces are bonded together by the cured resin composition, resulting in a laminated sample consisting of test piece / cured product / test piece.

[0207] For each resin composition, two laminated samples were prepared.

[0208] Using the obtained laminated specimens, tensile shear bond strength was determined according to JIS-K-6850. Specifically, using a Tensilon universal testing machine (TOYO BALDWIN "UTM-5T"), one specimen was stretched parallel to the plane relative to another, and the maximum load (N) at which the cured resin composition failed was measured. The test was conducted at a temperature of 25°C, relative humidity of 60%, and a tensile speed of 5 mm / min. The results were obtained from the measured maximum load (N) and the bond area (mm²) of the two specimens. 2 The shear bond strength is calculated using the following formula (M2). The average value of the measurements obtained from two laminated specimens is recorded in the table described later.

[0209] Shear bond strength (N / mm) 2 = Maximum load (N) / Bonding area (mm²) 2 (M2) The shear bond strength was determined using nickel test pieces. The shear bond strength obtained using nickel test pieces was evaluated according to the following criteria.

[0210] Good: Shear bond strength is above 10.0 MPa.

[0211] Defective: Shear bond strength less than 10.0 MPa.

[0212] In addition, the above-mentioned shear bond strength was determined using test pieces made of LCP (ENEOS Sun-Energy "Xydar CM-301B"). The shear bond strength obtained using LCP test pieces was evaluated according to the following criteria.

[0213] Good: Shear bond strength is above 4.0 MPa.

[0214] Defective: Shear bond strength less than 4.0 MPa.

[0215] <Evaluation Tests for Mechanical Strength (Elongation at Break and Tensile Modulus)> A PET film (Toray Industries, Inc., "NS-80A") with a release agent applied to its surface was prepared. A resin composition was applied to the PET film using a stick coating agent and cured at 80°C for 60 minutes to obtain a cured product with a thickness of 100 μm. The cured product was then cut using a cutter (Dumbbell Corporation, "Super Dumbbell Cutter (Model: SDMK-5889-01)") to prepare test pieces for tensile strength testing. The PET film was peeled off from the test pieces. Tensile tests were performed using a Tensilon universal testing machine (ORIENTEC Corporation, RTM-500) at a temperature of 25°C, humidity of 60%, and a tensile speed of 5 mm / min to determine the elongation at break and tensile modulus of elasticity.

[0216] The measured elongation at break was evaluated according to the following criteria.

[0217] Good: Elongation at break is above 3.0%.

[0218] Undesirable: Elongation at break is less than 3.0%.

[0219] The measured tensile modulus of elasticity was evaluated according to the following criteria.

[0220] Good: Tensile modulus of elasticity is less than 5000 MPa.

[0221] Undesirable: Tensile modulus of elasticity is above 5000 MPa.

[0222] <Evaluation Test of Thermal Conductivity> The resin composition was placed in a cylindrical container and heat-cured in a thermal cycling oven at 80°C for 60 minutes to produce a cylindrical cured product with a thickness of 10 mm and a diameter of φ36 mm. The thermal conductivity of the obtained cylindrical cured product was measured using the hot plate method with a thermophysical property measuring device (Kyoto Electronics Industry Co., Ltd. "TPS-2500") under a constant temperature environment of 25°C and 40% RH.

[0223] The measured thermal conductivity was evaluated according to the following criteria.

[0224] Good: Thermal conductivity is above 1.0 W / mK.

[0225] Yes: Thermal conductivity is above 0.5 W / m and less than 1.0 W / mK.

[0226] Disadvantage: Thermal conductivity less than 0.5 W / m.

[0227] <Evaluation Test for Moisture Resistance> (Test for determination of initial shear bond strength) Prepare two flat, soft steel plates (JISG3141, SPCC), and wipe away the oil using waste cotton yarn moistened with acetone. Then, grind the flat surfaces of the soft steel plates with a #120 seamless sanding belt to obtain the test piece.

[0228] On the polished surfaces of two test pieces, a resin composition is uniformly applied to a thickness of approximately 1 mm. The polished surfaces coated with the resin composition of the two test pieces are then pressed together with the polished surfaces overlapping each other by approximately 12 mm in width, and secured with two clamps. At this point, some of the resin composition seeps out from between the two test pieces; this seeped resin composition is immediately wiped away with waste cotton yarn. The test pieces are then evenly arranged in an oven and heated at 80°C for 60 minutes to cure the resin composition. Thus, the two test pieces are bonded together by the cured resin composition, resulting in a laminated sample consisting of test piece / cured product / test piece.

[0229] For each resin composition, two laminated samples were prepared.

[0230] Using the obtained laminated specimens, a tensile shear bond strength test was performed based on the same method described in the above-mentioned <Evaluation Test of Shear Bond Strength>, and the shear bond strength (tensile shear bond strength) was determined. The average value of the measured values ​​of the two laminated specimens in this way is called the "initial shear bond strength".

[0231] The initial shear bond strength was evaluated according to the following criteria.

[0232] Good: Initial shear bond strength is 10 N / mm.2 above.

[0233] Defect: Initial shear bond strength less than 10 N / mm 2 .

[0234] (Test for determining the shear bond strength after preservation) Following the same steps as described above (test for initial shear bond strength), two laminated specimens, consisting of a test piece / cured material / test piece, were prepared sequentially. These laminated specimens were then placed in a constant temperature and humidity test chamber at 85°C and 85%RH for 250 hours for preservation.

[0235] Using the laminated specimens after preservation testing, a tensile shear bond strength test was conducted using the same method described in the "Evaluation Test of Shear Bond Strength" section above, and the shear bond strength (tensile shear bond strength) was measured. The average value of the measured values ​​of the two laminated specimens in this way is called the "preserved shear bond strength".

[0236] (Evaluation of the strength retention rate of shear bonding) To evaluate the effect of humidity on the bond strength of the cured resin composition, the strength retention rate was calculated. The strength retention rate is calculated from the initial shear bond strength S. A and the shear bond strength S after preservation B The value is calculated using the following formula (M1).

[0237] Strength retention rate (%) = S B / S A ×100 (M1) The strength retention rate of the calculated shear bond strength is evaluated according to the following criteria.

[0238] Good: Strength retention rate is above 80%.

[0239] Yes: Strength retention rate is above 60% and less than 80%.

[0240] Unacceptable: Strength retention rate less than 60%.

[0241] <Results> The results of the above-described embodiments and comparative examples are shown in the following table. In the table below, the abbreviations have the following meanings.

[0242] “LCP”: Liquid Crystal Polymer "Elongation": Elongation at break "Modulus of elasticity": Tensile modulus of elasticity The "Initial" value in the moisture resistance section refers to the initial shear bond strength.

[0243] [Table 1] .

[0244] [Table 2] .

[0245] [Table 3] .

[0246] [Table 4] .

Claims

1. A resin composition comprising: (A) a liquid epoxy resin, (B) an inorganic filler, and (C) a first thiol compound represented by formula (I) below, wherein, (B) The amount of inorganic filler is 20% or more, relative to 100% by volume of the non-volatile components of the resin composition. [Chemical Formula 1] In formula (I), ring P is independently either phenyl or naphthyl. When ring P is phenyl, there are 1 to 5 atoms for each ring P; when ring P is naphthyl, there are 1 to 7 atoms for each ring P, and each a atom is independently -R. 1 -SH, R 1 Each is independently a C1-C6 alkylene group optionally substituted with one or more Y atoms. B is a group other than A on ring P, which is independently a hydrogen atom, a C1-C6 alkyl group optionally substituted with one or more Y atoms, or a C1-C6 alkoxy group optionally substituted with one or more Y atoms. When ring P is phenyl, A and B are independently bonded to the ortho, meta, or para positions relative to the position where ring P is bonded to the main chain. When ring P is naphthyl, A and B are independently bonded to the ortho, meta, para, remote, epitope, telomere, proximal, anterior, transposition, or 2,7 positions relative to the position where ring P is bonded to the main chain. X is independently -CH2-, -O-, or -N(-R) 2 - or -S-, R 2 Each of the following is independently a hydrogen atom, a C1-C6 alkyl group optionally substituted with one or more Y atoms, or a C1-C6 alkoxy group optionally substituted with one or more Y atoms. Y can be independently a hydrogen atom, a C1-C6 alkyl group, or a C1-C6 alkoxy group. Z can be independently direct-bonded, -CH2-, -C2H4-, -C3H6-, -C4H8-, -O-, or -S-. n is an integer from 1 to 20.

2. The resin composition according to claim 1, wherein, (C) The first thiol compound comprises one or more selected from the following formula (I-1), formula (I-2), formula (I-3), formula (I-4), formula (I-5), and formula (I-6). [Chemical Formula 2] 。 3. The resin composition according to claim 1, wherein, Contains (D) curing agent.

4. The resin composition according to claim 3, wherein, (D) The curing agent contains (D-1) a dithiol compound. (D-1) The second thiol compound has more than three thiol groups in one molecule, contains a cyclic skeleton, and is not a compound represented by formula (I).

5. The resin composition according to claim 4, wherein, (C) The equivalence ratio of the first thiol compound to the (D-1) second thiol compound is 0.1 or more and 50.0 or less.

6. The resin composition according to claim 1, wherein, (B) The thermal conductivity of the inorganic filler material is above 1.0 W / mK and below 300 W / mK.

7. The resin composition according to claim 1, wherein, (B) The specific surface area of ​​the inorganic filler material is 0.1 m². 2 / g or more and 10m 2 / g or less.

8. The resin composition according to claim 1, wherein, Contains (E) preservation stabilizer.

9. The resin composition according to claim 1, wherein, Contains (F) curing accelerator.

10. The resin composition according to claim 1, wherein, The thermal conductivity of the cured product obtained by curing the resin composition at 80°C for 60 minutes is greater than 0.5 W / mK and less than 10 W / mK.

11. The resin composition according to claim 1, wherein, The tensile modulus of elasticity of the cured product obtained by curing the resin composition at 80°C for 60 minutes is 10 MPa or more and 5000 MPa or less.

12. The resin composition according to claim 1, wherein, The cured product obtained by curing the resin composition at 80°C for 60 minutes has an elongation at break of 3% or more and 300% or less.

13. A resin sheet comprising: a support body and a resin composition layer formed on the support body, The resin composition layer comprises the resin composition according to any one of claims 1 to 12.

14. An electronic component comprising: a heat sink, a cured resin composition of any one of claims 1 to 12 disposed on the heat sink, and an electronic component mounted on the cured resin composition.

15. A semiconductor device comprising a cured product of the resin composition according to any one of claims 1 to 12.

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