JP2010132840A - Epoxy resin composition for adhesive sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive sheet having excellent storage stability, a cured adhesive sheet having high thermal conductivity and electrical insulation as well as excellent adhesiveness, and an epoxy resin composition for adhesive sheets suitable for producing the adhesive sheet and the cured adhesive sheet. <P>SOLUTION: The epoxy resin composition for adhesive sheets includes (A) an insulating filler having high thermal conductivity, (B) an epoxy resin, (C) a microencapsulated latent curing agent, and (D) a sheet-forming agent. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an epoxy resin composition for an adhesive sheet, an adhesive sheet formed from the resin composition, a cured adhesive sheet, and a heat dissipation member using the adhesive sheet.

In recent years, demands for higher performance and smaller size of electronic devices have increased, and higher density and higher functionality of semiconductors have been demanded. In order to achieve higher density and higher functionality of semiconductors, it is important to design mounting materials that take into account heat dissipation from the semiconductor or heat dissipation from the circuit board on which the semiconductor is mounted.
In order to improve heat dissipation of power modules, liquid crystal drivers, semiconductor chips such as various CPUs and MPUs, or substrates on which they are mounted, studies have been made on highly thermally conductive materials.
For example, Patent Document 1 discloses an adhesive sheet (sheet-like adhesive) obtained by dissolving a solid epoxy resin in a solvent, mixing a highly thermally conductive inorganic filler, and then forming a thin film to volatilize the solvent; A highly thermally conductive material made from the adhesive sheet is disclosed.
Japanese Patent Laid-Open No. 10-173097

  However, the adhesive sheet described in Patent Document 1 has a problem in that a sheet in a semi-cured state reacts during storage and the characteristics change. Further, in Patent Document 1, it is considered to produce a sheet without using a solvent. In this case, since the viscosity of the resin composition that is a material for the adhesive sheet is high, filling with a highly thermally conductive filler is performed. As a result, there is a problem that the thermal conductivity of the adhesive sheet cannot be sufficiently increased.

  In view of the above circumstances, the problem to be solved by the present invention is an adhesive sheet excellent in storage stability, an adhesive sheet cured product having high thermal conductivity and electrical insulation, and excellent adhesiveness, and production thereof. It is providing the suitable epoxy resin composition for adhesive sheets.

  As a result of intensive studies in order to solve the above problems, the present inventors have made a highly heat conductive insulating filler (A), an epoxy resin (B), a microcapsule type latent curing agent (C), and a sheet. It discovered that the epoxy resin composition for adhesive sheets containing an agent (D) can solve the said subject, and completed this invention.

That is, the present invention is as follows.
[1]
A high thermal conductive insulating filler (A);
Epoxy resin (B);
A microcapsule-type latent curing agent (C);
Sheeting agent (D);
An epoxy resin composition for an adhesive sheet containing
[2]
The epoxy resin composition for an adhesive sheet according to the above [1], wherein the high thermal conductive insulating filler (A) is a metal powder coated with an organic resin.
[3]
The epoxy resin composition for an adhesive sheet according to the above [2], wherein the metal species of the metal powder is aluminum.
[4]
The microcapsule-type latent curing agent (C) is a microcapsule-type latent curing agent having at least a core (K) and a shell (S) that covers the core (K),
Said shell (S) is bonded group that absorbs infrared wave number 1630～1680Cm ^-1 at least on its surface (x), binding group that absorbs infrared wave number 1680~1725cm ^-1 (y), and the wave number 1730~1755cm ^-1 having a bonding group (z) that absorbs infrared rays,
The ratio (Cx / (Cx + Cy + Cz)) of the concentration (Cx) of the bonding group (x) in the shell (S) to the total concentration (Cx + Cy + Cz) of the bonding groups (x), (y) and (z) is The epoxy resin composition for an adhesive sheet according to any one of the above [1] to [3], which is 0.50 or more and less than 0.75.
[5]
The epoxy resin composition for adhesive sheets according to any one of the above [1] to [4], further comprising an organic solvent (E).
[6]
The adhesive sheet formed from the epoxy resin composition for adhesive sheets in any one of said [1]-[5].
[7]
A cured adhesive sheet obtained by heat-curing the adhesive sheet according to the above [6].
[8]
A heat dissipating member comprising the adhesive sheet according to the above [6] and a metal piece.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive sheet excellent in storage stability, the adhesive sheet hardened | cured material with high heat conductivity and electrical insulation, and excellent adhesiveness, and the epoxy resin composition for adhesive sheets suitable for these manufacture Can be provided.

  Hereinafter, the best mode for carrying out the present invention (hereinafter, this embodiment) will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

[Epoxy resin composition for adhesive sheet]
The epoxy resin composition for adhesive sheets of this embodiment is
A high thermal conductive insulating filler (A), an epoxy resin (B), a microcapsule-type latent curing agent (C), and a sheeting agent (D) are contained. Hereinafter, each component will be described.

[High thermal conductive insulating filler (A)]
Examples of the high thermal conductive insulating filler include Al ₂ O ₃ (alumina), MgO, BN, AlN, Al (OH) ₃ , Mg (OH) ₃ , SiC, and metal powder coated with an organic resin. Especially, the metal powder coat | covered with the organic resin from a viewpoint which can produce the adhesive sheet hardened | cured material which has high heat conductivity and insulation is preferable.

  The high thermal conductive insulating filler (A) preferably has an average particle size defined by a median diameter of 0.1 to 300 μm, and more preferably 0.5 to 50 μm. Here, the average particle size refers to a value measured by a laser diffraction particle size distribution measuring device.

  The thermal conductivity of the high thermal conductive insulating filler is not particularly limited, but the thermal conductivity measured by a laser flash method is preferably 1 [W / m · ° C.] or more, and 10 [W / m · ° C.]. More preferably, it is more preferably 100 [W / m · ° C.].

[Metal powder coated with organic resin]
[Metal powder]
The metal powder that can be used as the metal powder of the metal powder coated with the above organic resin tends to be excellent in thermal conductivity, so copper, silver, aluminum, an alloy of copper and tungsten, a composite of copper and molybdenum A material etc. are preferable, and aluminum is more preferable from a viewpoint of manufacturing cost, availability, and thermal conductivity.

[Organic resin]
The organic resin that coats the metal powder is not particularly limited. For example, a thermoplastic resin, a cross-linked resin, and the like can be used, and among them, the mechanical strength tends to be good. preferable.

[Thermoplastic resin]
The thermoplastic resin is not particularly limited, and examples thereof include an acrylic resin, a polyolefin resin such as polyethylene and polypropylene, a polyimide resin, a silicone resin, a silicone rubber, and a fluororesin.

[Cross-linked resin]
The crosslinkable resin is not particularly limited. For example, a cross-linked polyolefin resin such as a crosslinkable acrylic resin, crosslinkable polypropylene, and crosslinkable polyethylene, a crosslinkable polyimide resin, a cured epoxy resin, a crosslinkable silicone resin, and a crosslinkable resin. Examples thereof include silicone rubber, cross-linkable fluororesin, epoxy acrylate resin, unsaturated polyester resin, and the like. Especially, since it exists in the tendency for mechanical strength to become favorable, an epoxy resin, an epoxy acrylate resin, and a crosslinked acrylic resin are preferable, and a crosslinked acrylic resin is more preferable.

[Crosslinked acrylic resin]
Examples of the cross-linked acrylic resin include resins described in JP-B-1-49746. The cross-linked acrylic resin has, for example, a monomer having three or more polymerizable double bonds in one molecule as an essential component, and optionally has a radical polymerizable unsaturated carboxylic acid and a radical polymerizable double bond. It can be obtained by reacting one or more radically polymerizable compounds selected from phosphoric acid ester monomers.

  Examples of the monomer having three or more polymerizable double bonds in one molecule include trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, tetramethylolmethane triacrylate, tetramethylolmethane tetraacrylate, and the like. Of these, trimethylolpropane triacrylate is preferred because the organic resin tends to coat the metal surface more firmly.

  Examples of the radical polymerizable unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, and fumaric acid. Acrylic acid is preferred from the viewpoint of availability at low cost.

  Examples of the phosphoric acid monoester monomer having a radical polymerizable double bond include 2-methacryloyloxyethyl phosphate, di-2-methacryloyloxyethyl phosphate, tri-2-methacryloyloxyethyl phosphate, 2- Acryloyloxyethyl phosphate, di-2-acryloyloxyethyl phosphate, tri-2-acryloyloxyethyl phosphate, diphenyl-2-methacryloyloxyethyl phosphate, diphenyl-2-acryloyloxyethyl phosphate, dibutyl-2- Methacryloyloxyethyl phosphate, dibutyl-2-acryloyloxyethyl phosphate, dioctyl-2-methacryloyloxyethyl phosphate, dioctyl-2-acryloyloxyethyl phosphate, 2-methacrylate Examples include leuoxypropyl phosphate, bis (2-chloroethyl) vinyl phosphonate, diallyl dibutyl phosphonosuccinate and the like. Among them, organic resin tends to coat the metal surface more strongly, so 2-methacryloyloxyethyl phosphate 2-acryloyloxyethyl phosphate is preferred.

  Although it does not restrict | limit especially as a compounding quantity of the highly heat conductive insulating filler (A) in the epoxy resin composition for adhesive sheets, It is preferable that it is 10-2000 mass parts with respect to 100 mass parts of epoxy resins (B). 100 to 500 parts by mass is more preferable. If the blending amount of the high thermal conductive insulating filler is 10 parts by mass or more, the thermal conductivity of the cured adhesive sheet tends to be sufficient, and if it is 2000 parts by mass or less, it is mixed into a resin composition and formed into a sheet. Tends to be easier.

[Epoxy resin (B)]
Examples of the epoxy resin (B) include a monoepoxy compound, a polyvalent epoxy compound, or a mixture thereof.

  Examples of the monoepoxy compound include butyl glycidyl ether, hexyl glycidyl ether, phenyl glycidyl ether, allyl glycidyl ether, para-tert-butylphenyl glycidyl ether, ethylene oxide, propylene oxide, paraxyl glycidyl ether, glycidyl acetate, glycidyl butyrate. Glycidyl hexoate, glycidyl benzoate and the like.

  Examples of the polyvalent epoxy compound include bisphenol A, bisphenol F, bisphenol AD, bisphenol S, tetramethyl bisphenol A, tetramethyl bisphenol F, tetramethyl bisphenol AD, tetramethyl bisphenol S, tetrabromobisphenol A, and tetrachlorobisphenol A. Bisphenol type epoxy resin obtained by glycidylation of bisphenols such as tetrafluorobisphenol A; epoxy resin obtained by glycidylation of other dihydric phenols such as biphenol, dihydroxynaphthalene and 9,9-bis (4-hydroxyphenyl) fluorene; 1,1,1-tris (4-hydroxyphenyl) methane, 4,4- (1- (4- (1- (4-hydroxyphenyl) -1-methylethyl) pheny ) Ethylidene) Epoxy resin glycidylated trisphenols such as bisphenol; Epoxy resin glycidylated tetrakisphenols such as 1,1,2,2, -tetrakis (4-hydroxyphenyl) ethane; Phenol novolac, Cresol novolac , Bisphenol A novolak, brominated phenol novolak, novolak type epoxy resin obtained by glycidylation of novolak such as brominated bisphenol A novolak, etc .; epoxy resin obtained by glycidylation of polyhydric phenols; polyhydric alcohol such as glycerin and polyethylene glycol Glycidylated aliphatic ether type epoxy resin; ether ester type epoxy resin obtained by glycidylation of hydroxycarboxylic acid such as p-oxybenzoic acid and β-oxynaphthoic acid; phthalic acid, Glycidyl ester esters such as glycidylated polycarboxylic acids such as terephthalic acid; glycidylated amine compounds such as 4,4-diaminodiphenylmethane and m-aminophenol, and glycidyl such as amine-type epoxy resins such as triglycidyl isocyanurate Type epoxy resin; and alicyclic epoxides such as 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate.

  The epoxy resin (B) tends to be a cured product having a good balance between heat resistance and mechanical strength. Among them, among them, bisphenol A type epoxy resin, bisphenol F type epoxy resin, 3,4-epoxycyclohexyl, etc. Methyl-3 ′, 4′-epoxycyclohexanecarboxylate is preferred, and bisphenol A type epoxy resin is more preferred.

[Microcapsule type latent curing agent (C)]
The epoxy resin composition for adhesive sheets of this Embodiment contains a microcapsule-type latent hardening agent (C). By containing the microcapsule-type latent curing agent (C) in the resin composition, the storage stability of the epoxy resin composition and the storage stability of the uncured adhesive sheet formed from the resin composition are Compared with the case where a curing agent other than the microcapsule type latent curing agent is used, it becomes better. The effect tends to be prominent particularly when a solvent is used in the resin composition (hereinafter, a mixed solution of the resin composition and the solvent is also referred to as “varnish”).

  The microcapsule-type latent curing agent (C) is an epoxy resin curing agent having a structure in which the surface of the epoxy resin curing agent particles is coated with an inactive film with respect to the epoxy resin and the curing agent particles. Examples of such a curing agent are disclosed in JP-A-1-217027, JP-A-60-260610, JP-A-64-70523, JP-A-4-53818, and the like.

The microcapsule-type latent curing agent (C) is preferably a microcapsule-type latent curing agent having at least a core (K) and a shell (S) that covers the core, and the shell (S). but binding group that absorbs infrared wave number 1630～1680Cm ^-1 at least on its surface (x), binding group that absorbs infrared wave number 1680~1725cm ^-1 (y), and the infrared wave number 1730～1755Cm ^-1 The total concentration of the bonding groups (x), (y) and (z) in the concentration (Cx) of the bonding group (x) in the shell (S) ( A microcapsule-type latent curing agent having a ratio (Cx / (Cx + Cy + Cz)) to Cx + Cy + Cz) of 0.50 or more and less than 0.75.

[Core (K)]
The core (K) is preferably formed using particles satisfying the following conditions (1) to (3) as starting materials.
(1) The main component is an amine curing agent,
(2) 0.05 to 3 parts by mass of water with respect to 100 parts by mass of the amine curing agent,
(3) The average particle size defined by the median diameter is more than 0.3 μm and 12 μm or less.

[Condition (1)]
First, condition (1) will be described.
Examples of amine curing agents include amine adducts, modified polyamines, aliphatic polyamines, heterocyclic polyamines, alicyclic polyamines, aromatic amines, polyamidoamines, ketimines, and urethane amines. Examples of the amine-based curing agent to be used. Among these, an amine-based curing agent composed of a low molecular amine compound (a1) and an amine adduct is preferable.

[Low molecular amine compound (a1)]
The low molecular amine compound (a1) includes at least one primary amino group and / or secondary amino group but no tertiary amino group, at least one tertiary amino group and at least one And a compound having an active hydrogen group.

  Examples of the compound having at least one primary amino group and / or secondary amino group but not a tertiary amino group include methylamine, ethylamine, propylamine, butylamine, ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, Primary amines having no tertiary amino group such as triethylenetetramine, ethanolamine, propanolamine, cyclohexylamine, isophoronediamine, aniline, toluidine, diaminodiphenylmethane, diaminodiphenylsulfone; dimethylamine, diethylamine, dipropylamine, Dibutylamine, dipentylamine, dihexylamine, dimethanolamine, diethanolamine, dipropanolamine, dicyclohexylamine, piperidine, piperide , Diphenylamine, phenyl methylamine, secondary amines having no tertiary amino group such as a phenyl ethyl amine and the like.

Compounds having at least one tertiary amino group and at least one active hydrogen group include 2-dimethylaminoethanol, 1-methyl-2-dimethylaminoethanol, 1-phenoxymethyl-2-dimethylaminoethanol, 2 -Amino alcohols such as diethylaminoethanol, 1-butoxymethyl-2-dimethylaminoethanol, methyldiethanolamine, triethanolamine, N-β-hydroxyethylmorpholine; 2- (dimethylaminomethyl) phenol, 2,4,6- Aminophenols such as tris (dimethylaminomethyl) phenol; 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, 1-aminoethyl 2-methylimidazole, 1- (2-hydroxy-3-phenoxypropyl) -2-methylimidazole, 1- (2-hydroxy-3-phenoxypropyl) -2-ethyl-4-methylimidazole, 1- (2- Imidazoles such as hydroxy-3-butoxypropyl) -2-methylimidazole and 1- (2-hydroxy-3-butoxypropyl) -2-ethyl-4-methylimidazole; 1- (2-hydroxy-3-phenoxypropyl) ) -2-phenylimidazoline, 1- (2-hydroxy-3-butoxypropyl) -2-methylimidazoline, 2-methylimidazoline, 2,4-dimethylimidazoline, 2-ethylimidazoline, 2-ethyl-4-methylimidazoline 2-benzylimidazoline, 2-phenylimidazoline, 2- ( o-tolyl) -imidazoline, tetramethylene-bis-imidazoline, 1,1,3-trimethyl-1,4-tetramethylene-bis-imidazoline, 1,3,3-trimethyl-1,4-tetramethylene-bis- Imidazoline, 1,1,3-trimethyl-1,4-tetramethylene-bis-4-methylimidazoline, 1,3,3-trimethyl-1,4-tetramethylene-bis-4-methylimidazoline, 1,2- Imidazolines such as phenylene-bis-imidazoline, 1,3-phenylene-bis-imidazoline, 1,4-phenylene-bis-imidazoline, 1,4-phenylene-bis-4-methylimidazoline; dimethylaminopropylamine, diethylaminopropyl Amine, dipropylaminopropylamine, dibutylaminopropylamine, Tertiary aminoamines such as methylaminoethylamine, diethylaminoethylamine, dipropylaminoethylamine, dibutylaminoethylamine, N-methylpiperazine, N-aminoethylpiperazine, diethylaminoethylpiperazine; 2-dimethylaminoethanethiol, 2-mercaptobenzimidazole Aminomercaptans such as 2-mercaptobenzothiazole, 2-mercaptopyridine and 4-mercaptopyridine; amino such as N, N-dimethylaminobenzoic acid, N, N-dimethylglycine, nicotinic acid, isonicotinic acid and picolinic acid Carboxylic acids; aminohydrazides such as N, N-dimethylglycine hydrazide, nicotinic acid hydrazide, isonicotinic acid hydrazide and the like.

  Among these low-molecular amine compounds (a), imidazoles are preferable because 2-high responsiveness and industrial availability tend to be easily obtained, and 2-ethyl-4-methylimidazole and 2-methylimidazole are more preferable. .

[Amine adduct]
As the amine adduct, an amino group obtained by a reaction between one kind selected from the group consisting of a carboxylic acid compound, a sulfonic acid compound, a urea compound, an isocyanate compound, and an epoxy resin (e1) and an amine compound (a2) is used. And the like.

  Examples of the carboxylic acid compound include succinic acid, adipic acid, sebacic acid, phthalic acid, and dimer acid.

  Examples of the sulfonic acid compound include ethanesulfonic acid and p-toluenesulfonic acid.

  Examples of the urea compound include urea, methylurea, dimethylurea, ethylurea, t-butylurea and the like.

  Examples of the isocyanate compound include aliphatic diisocyanate, alicyclic diisocyanate, aromatic diisocyanate, aliphatic triisocyanate, and polyisocyanate.

  Examples of the aliphatic diisocyanate include ethylene diisocyanate, propylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate.

  Examples of the alicyclic diisocyanate include isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, norbornane diisocyanate, 1,4-isocyanatocyclohexane, 1,3-bis (isocyanatomethyl) -cyclohexane, 1,3-bis (2 -Isocyanatopropyl-2-yl) -cyclohexane and the like.

  Examples of the aromatic diisocyanate include tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylene diisocyanate, 1,5-naphthalene diisocyanate, and the like.

  Examples of the aliphatic triisocyanate include 1,6,11-undecane triisocyanate, 1,8-diisocyanate-4-isocyanate methyloctane, 1,3,6-triisocyanate methylhexane, and the like.

  Examples of the polyisocyanate include polymethylene polyphenyl polyisocyanate and polyisocyanate derived from the diisocyanate compound. Examples of the polyisocyanate derived from the diisocyanate include isocyanurate type polyisocyanate, burette type polyisocyanate, urethane type polyisocyanate, allophanate type polyisocyanate, and carbodiimide type polyisocyanate.

  Examples of the epoxy resin (e1) include a monoepoxy compound, a polyvalent epoxy compound, or a mixture thereof. What was enumerated as a compound used for an epoxy resin (B) can be used as a monoepoxy compound and a polyhydric epoxy compound.

  The total chlorine content of the epoxy resin (e1) is preferably 2500 ppm or less from the viewpoint of obtaining an epoxy resin composition having an excellent balance between curability and storage stability. The total chlorine content of the epoxy resin (e1) is more preferably 2000 ppm or less, more preferably 1500 ppm or less, more preferably 800 ppm or less, more preferably 400 ppm or less, and more preferably 180 ppm or less. More preferably, it is 100 ppm or less, More preferably, it is 80 ppm or less, Most preferably, it is 50 ppm or less.

Here, the total chlorine amount is the total amount of organic chlorine and inorganic chlorine contained in the epoxy resin, and is a mass-based value for the epoxy resin.
The total chlorine amount can be measured by the following method.
The epoxy resin composition is repeatedly washed and filtered with xylene until the epoxy resin is exhausted. Next, the filtrate is distilled off under reduced pressure at 100 ° C. or lower to obtain an epoxy resin. 1-10 g of the obtained epoxy resin sample was precisely weighed so that the titration amount was 3-7 mL, dissolved in 25 mL of ethylene glycol monobutyl ether, and 25 mL of 1N KOH propylene glycol solution was added thereto and boiled for 20 minutes. After that, it is calculated from the titration titrated with an aqueous silver nitrate solution.

  Moreover, it is preferable that the total chlorine amount of an epoxy resin (e1) is 0.01 ppm or more from a viewpoint of making control of shell formation reaction easy. The total chlorine content of the epoxy resin (e1) is more preferably 0.02 ppm or more, more preferably 0.05 ppm or more, further preferably 0.1 ppm or more, and even more preferably 0.2 ppm or more. Yes, particularly preferably 0.5 ppm or more. Further, when the total chlorine amount is 0.1 ppm or more, the shell formation reaction is efficiently performed on the core surface containing the curing agent, and a shell excellent in storage stability tends to be obtained.

  From the above, the preferable range of the total chlorine content of the epoxy resin (e1) is 0.1 ppm to 200 ppm, the more preferable range is 0.2 ppm to 80 ppm, and the more preferable range is 0.5 ppm to 50 ppm.

  Further, among all chlorine, chlorine contained in the 1,2-chlorohydrin group is generally called hydrolyzable chlorine. The amount of hydrolyzable chlorine in the epoxy resin (e1) is preferably 50 ppm or less, more preferably 0.01 to 20 ppm, and still more preferably 0.05 to 10 ppm. When the hydrolyzable chlorine content is 50 ppm or less, it is advantageous from the viewpoint of achieving both high curability and storage stability, and the cured product tends to exhibit excellent electrical characteristics.

Here, hydrolyzable chlorine can be measured by the following method.
3 g of a sample is dissolved in 50 mL of toluene, and 20 mL of 0.1 N KOH methanol solution is added thereto, boiled for 15 minutes, and then calculated from the titration titrated with an aqueous silver nitrate solution.

  Moreover, as the amine compound (a2), the same amine compound as mentioned as an example of the low molecular amine compound (a1) can be used.

As the amine adduct, since it tends to be a microcapsule type epoxy resin curing agent having excellent storage stability, an amine adduct is particularly preferably obtained by a reaction between the epoxy resin (e1) and the amine compound (a2).
The amine adduct obtained by the reaction between the epoxy resin (e1) and the amine compound (a2) is also preferable in that the unreacted amine compound (a2) can be used as the low-molecular amine compound (a1).

  The amine adduct obtained by the reaction of the epoxy resin (e1) and the amine compound (a2) is, for example, the epoxy resin (e1) and the amine compound (a2) with respect to 1 equivalent of the epoxy group of the epoxy resin (e1). As long as the active hydrogen group of the amine compound (a2) is preferably 0.5 equivalents to 10 equivalents, more preferably 0.8 equivalents to 5 equivalents, still more preferably 0.95 equivalents to 4 equivalents. Accordingly, it can be obtained by reacting at a temperature of 50 to 250 ° C. for 0.1 to 10 hours in the presence of a solvent. When the equivalent ratio of the active hydrogen group of the amine compound (a2) to the epoxy group of the epoxy resin (e1) is 0.5 or more, it is advantageous to obtain an amine adduct having a molecular weight distribution of 7 or less, and the equivalent ratio is 10 The following is advantageous because the unreacted amine compound (a2) can be used as it is as the low-molecular amine compound (a1) without being recovered. Here, when the molecular weight of the amine adduct is 7 or less, there is an advantage that the fluidity during curing tends to be excellent.

  In the reaction for obtaining an amine adduct by the epoxy resin (e1) and the amine compound (a2), examples of the solvent used as necessary include hydrocarbons such as benzene, toluene, xylene, cyclohexane, mineral spirit, naphtha; acetone Ketones such as methyl ethyl ketone and methyl isobutyl ketone; esters such as ethyl acetate, n-butyl acetate and propylene glycol monomethyl ether acetate; alcohols such as methanol, isopropanol, n-butanol, butyl cellosolve and butyl carbitol; water and the like These solvents may be used alone or in combination.

  Further, “main component” in the condition (1) means that the content is 50% by mass or more. In addition to the amine-based curing agent described above, the particles used as starting materials for forming the core (K) include acid anhydrides such as phthalic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, and methyl nadic acid. Phenolic curing agents such as phenol novolak, cresol novolak, bisphenol A novolak; propylene glycol-modified polymercaptan, thiogluconic acid ester of trimethylolpropane, mercaptan curing agent such as polysulfide resin; ethylamine salt of trifluoroborane, etc. Boron halide salt curing agent: quaternary ammonium salt curing agent such as phenol salt of 1,8-diazabicyclo (5,4,0) -undec-7-ene; 3-phenyl-1,1-dimethylurea Urea curing agents such as triphenylphosphine, tetraf Cycloalkenyl phosphonium tetraphenylborate and the like of a phosphine-based curing agent such as an epoxy resin curing agent (h1) may be used in combination.

Next, condition (2) will be described.
The particles serving as a starting material for forming the core (K) preferably contain 0.05 to 3 parts by mass of water with respect to 100 parts by mass of the amine-based curing agent as the main component. The water content is generated according to the usual water content quantification method, for example, the Karl Fischer method using coulometric titration, the gas chromatography method using a TCD (Thermal Conductivity Detector) detector, a chemical reaction, and depending on the water content. It can be measured by a quantitative method based on the amount of hydrogen gas to be used.

  When the particles used as the starting material for forming the core (K) contain 0.05 parts by mass or more of water with respect to 100 parts by mass of the amine-based curing agent, the shell (S) can be efficiently formed on the particle surface. In addition, the formed shell (S) tends to be a film having excellent storage stability and solvent resistance. On the other hand, when water is contained in an amount of 3 parts by mass or less with respect to 100 parts by mass of the amine-based curing agent, the particles are less likely to be fused and aggregated, and it is easy to manage stable quality. This phenomenon also affects the formation of the shell (S), making it easy to control the content of specific bonding groups present on the surface of the shell (S), and curing for microcapsule type epoxy resins with stable quality. A curing agent composition for a masterbatch type epoxy resin (hereinafter also referred to as a masterbatch type curing agent) can be obtained.

Next, the condition (3) will be described.
The particle size of the particles that are the starting material for forming the core (K) is preferably such that the average particle size defined by the median diameter is more than 0.3 μm and 12 μm or less, more preferably 1 μm to 10 μm, More preferably, it is 1.5 micrometers-5 micrometers. If the average particle size of the starting material particles is 12 μm or less, a homogeneous cured product tends to be obtained. If the average particle size exceeds 0.3 μm, aggregation between the particles hardly occurs and formation of a thin shell is facilitated. There is a tendency. Here, the average particle diameter means a Stokes diameter measured by a laser diffraction / light scattering method.

  The starting particles may be liquid or solid, but are preferably solid at 25 ° C. When the starting material particles are solid, the form may be any of agglomerates, granules, and powders. Moreover, there is no restriction | limiting in shape, Either spherical shape and an indefinite shape may be sufficient.

[Shell (S)]
Shell (S) is absorbed infrared bonding group (y) and the wave number 1730～1755Cm ^-1 to absorb binding group that absorbs infrared wave number 1630～1680Cm ^-1 (x) and the infrared wave number 1680～1725Cm ^-1 And the ratio Cx / (Cx + Cy + Cz) of the concentration Cx of the bonding group (x) to the total concentration Cx + Cy + Cz of the bonding group (x), (y), (z). , 0.50 or more and less than 0.75 is preferable.

  Here, although infrared absorption can be measured using an infrared spectrophotometer, it is particularly preferable to measure using an infrared spectrophotometer.

  The linking group (x) is preferably a urea linking group. The linking group (y) is preferably a burette group. The linking group (z) is preferably a urethane linking group.

  If the concentration ratio Cx / (Cx + Cy + Cz) of the concentration Cx of the bonding group (x) to the total concentration Cx + Cy + Cz of the bonding groups (x), (y), (z) is less than 0.50, the solvent resistance tends to be inferior. When the concentration ratio Cx / (Cx + Cy + Cz) is 0.75 or more, the microcapsule type epoxy resin curing agent (C) particles are likely to be fused and aggregated, and the microcapsule type epoxy resin curing agent. It becomes difficult to manage (C) or the master batch type curing agent with stable quality.

  Moreover, it is preferable that the shell (S) in this embodiment has a urea group, a burette group, and a urethane group, and does not have an ester group. When the shell (S) has an ester bond, the ester bond undergoes a hydrolysis reaction in a high humidity state to damage the shell (S), and the storage stability of the microcapsule type latent curing agent or the masterbatch type curing agent. There is a possibility that the physical properties of the cured product of the epoxy resin composition containing these and moisture resistance may be lowered.

  Further, the shell (S) in the present embodiment includes a reaction product of an isocyanate compound and an active hydrogen compound and / or a reaction product of an epoxy resin curing agent (h2) and an epoxy resin (e2). Is preferred.

  As an isocyanate compound, the same thing as the isocyanate compound quoted as an example of the raw material of the amine adduct contained in the above-mentioned core (K) can be used.

  The active hydrogen compound is water, a compound having at least one primary amino group and / or a secondary amino group, a compound having at least one hydroxyl group, and the like, and an ester group in its structure Those not used are preferably used. These compounds can also be used in combination.

  Examples of the compound having at least one primary amino group and / or secondary amino group include aliphatic amines, alicyclic amines, and aromatic amines.

  Aliphatic amines include alkylamines such as methylamine, ethylamine, propylamine, butylamine, and dibutylamine; alkylenediamines such as ethylenediamine, propylenediamine, butylenediamine, and hexamethylenediamine; diethylenetriamine, triethylenetetramine, and tetraethylenepentamine. And polyoxyalkylene polyamines such as polyoxypropylene diamine and polyoxyethylene diamine.

  Examples of the alicyclic amine include cyclopropylamine, cyclobutylamine, cyclopentylamine, cyclohexylamine, and isophoronediamine.

  Aromatic amines include aniline, toluidine, benzylamine, naphthylamine, diaminodiphenylmethane, diaminodiphenylsulfone, and the like.

  Examples of the compound having at least one hydroxyl group include alcohol compounds and phenol compounds.

  Examples of alcohol compounds include methyl alcohol, propyl alcohol, butyl alcohol, amyl alcohol, hexyl alcohol, heptyl alcohol, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, dodecyl alcohol, stearyl alcohol, eicosyl alcohol, Monoalcohols such as allyl alcohol, crotyl alcohol, propargyl alcohol, cyclopentanol, cyclohexanol, benzyl alcohol, cinnamyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether, diethylene glycol monobutyl Class: ethylene glycol, polyethylene glycol, propylene Recall, polypropylene glycol, 1,3-butanediol, 1,4-butanediol, hydrogenated bisphenol A, neopentyl glycol, glycerol, trimethylolpropane, polyhydric alcohols such as pentaerythritol. Further, two secondary hydroxyl groups obtained by reaction of a compound having at least one epoxy group with a compound having at least one hydroxyl group, carboxyl group, primary or secondary amino group, or mercapto group in one molecule. The compounds having the above are also exemplified as polyhydric alcohols. These alcohol compounds may be any of primary, secondary, or tertiary alcohols.

  Examples of the phenol compound include monophenols such as carboxylic acid, cresol, xylenol, carvacrol, motile, and naphthol; and polyhydric phenols such as catechol, resorcin, hydroquinone, bisphenol A, bisphenol F, pyrogallol, and phloroglucin.

  As the compound having at least one hydroxyl group, polyhydric alcohols and polyhydric phenols are preferable, and polyhydric alcohols are more preferable.

  The reaction between the isocyanate compound and the active hydrogen compound is usually carried out in the temperature range of -10 ° C to 150 ° C for a reaction time of 10 minutes to 12 hours. Moreover, it can carry out in a dispersion medium as needed. Examples of the dispersion medium include a solvent, a plasticizer, and resins. Solvents include hydrocarbons such as benzene, toluene, xylene, cyclohexane, mineral spirit, naphtha; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ethyl acetate, acetic acid-n-butyl, propylene glycol monomethyl ethyl ether acetate, etc. Esters of; alcohols such as methanol, isopropanol, n-butanol, butyl cellosolve, butyl carbitol; water and the like. Examples of plasticizers include phthalic acid diesters such as dibutyl phthalate and di (2-ethylhexyl) phthalate; aliphatic dibasic acid esters such as di (2-ethylhexyl) adipate; and triphosphates such as tricresyl phosphate. Ester type; glycol ester type such as polyethylene glycol ester and the like. Examples of the resins include silicone resins, epoxy resins, phenol resins and the like.

  The reaction product of the isocyanate compound and the active hydrogen compound preferably has a urea bond and does not have an ester bond, and preferably has a burette bond and a urethane bond.

  Next, as the epoxy resin curing agent (h2), an amine curing agent contained in the particles used as a starting material for forming the core (K), or an epoxy resin curing agent ( Although the examples given for h1) can be used, the hardener for epoxy resin (h2) is the same as the amine-based hardener contained in the core (K) because a strong shell tends to be formed. It is preferable.

  Examples of the epoxy resin (e2) include a monoepoxy compound, a polyvalent epoxy compound, or a mixture thereof. What was enumerated as a compound used for an epoxy resin (B) can be used as a monoepoxy compound and a polyhydric epoxy compound.

  Moreover, even if the epoxy resin (e2) is the same as the epoxy resin (e1) contained in the above-mentioned core (K) and the epoxy resin (e3) contained in the curing agent composition for a masterbatch type epoxy resin described later. , May be different.

  Epoxy resins usually have impure ends with chlorine bonded in the molecule, but such impure ends may adversely affect the electrical properties of the cured product. Therefore, the total chlorine content of the epoxy resin (e2) is preferably 2500 ppm or less, more preferably 1500 ppm or less, and further preferably 500 ppm or less.

  The reaction between the epoxy resin (e2) and the epoxy resin curing agent (h2) is usually in the temperature range of −10 ° C. to 150 ° C., preferably 0 ° C. to 100 ° C., for 1 to 168 hours, preferably 2 hours to 72 hours. The reaction time is as follows and can also be carried out in a dispersion medium. Examples of the dispersion medium include a solvent and a plasticizer. As the solvent and plasticizer, those mentioned as examples of the solvent and plasticizer that can be used in the reaction of the aforementioned isocyanate compound and active hydrogen compound can be used.

  The method for forming the shell (S) so as to cover the core (K) is not particularly limited. For example, the particles used as the starting material for forming the core (K) are dispersed in a dispersion medium, and this dispersion is performed. Add a material that forms a shell to the medium and deposit it on the starting material particles, or add a raw material of the material that forms the shell to the dispersion medium and use the surface of the starting material particles as a reaction field, where the shell forming material The method etc. which produce | generate are mentioned. The latter method is preferable because the reaction and the coating can be performed simultaneously. Examples of the dispersion medium include a solvent, a plasticizer, and a resin. As the solvent, plasticizer, and resin, those mentioned as examples of the solvent, plasticizer, and resin that can be used in the reaction of the aforementioned isocyanate compound and active hydrogen compound can be used. Here, when an epoxy resin is used as a dispersion medium, a masterbatch type epoxy resin curing agent composition can be obtained simultaneously with shell formation.

  The shell formation reaction is usually performed at a temperature range of −10 ° C. to 150 ° C., preferably 0 ° C. to 100 ° C., for a reaction time of 10 minutes to 24 hours, preferably 2 hours to 10 hours.

  The compounding amount of the microcapsule-type latent curing agent (C) in the epoxy resin composition for an adhesive sheet is not particularly limited, but is preferably 1 to 100 parts by mass with respect to 100 parts by mass of the epoxy resin (B). Preferably it is 10-50 mass parts. When the blending amount of the microcapsule type latent curing agent (C) is 100 parts by mass or more, the mechanical strength of the cured product tends to decrease, and when it is 1 part by mass or less, the curing reaction tends to be slow. is there.

[Hardener composition for masterbatch type epoxy resin]
The microcapsule type latent curing agent (C) can be blended in the form of a masterbatch mixed with the epoxy resin (e3), that is, as a curing agent composition for a masterbatch type epoxy resin.

  Examples of the epoxy resin (e3) include a monoepoxy compound, a polyvalent epoxy compound, or a mixture thereof. What was enumerated as a compound used for an epoxy resin (B) can be used as a monoepoxy compound and a polyhydric epoxy compound.

  As a method for producing a curing agent for a masterbatch type epoxy resin, a method of dispersing a curing agent for a microcapsule type epoxy resin in an epoxy resin (e3) using, for example, a three roll, an epoxy resin (e3 ) Is used as a dispersion medium to carry out a coating reaction of the core (K) to obtain a microcapsule-type latent curing agent (C), and at the same time, a method of obtaining a masterbatch type epoxy resin curing agent.

[Sheeting agent (D)]
The epoxy resin composition for adhesive sheets of this Embodiment contains a sheet agent (D). Specific examples of the sheeting agent (D) include phenoxy resin, solid epoxy resin, polyester resin, polyamide resin, urethane resin, acrylic rubber, polymethyl methacrylate powder, cross-linked polybutyl acrylate or cross-linked polystyrene as a core, Examples include polymethylmethacrylate powders such as core-shell type powder with methyl methacrylate as the shell, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer powder, etc. Among them, excellent adhesion and mechanical strength Phenoxy resin and acrylic rubber are preferable because a cured adhesive sheet tends to be obtained. These resins can be used alone or in combination of two or more as required.

  Specific examples of the phenoxy resin include “PKHC” and “PKHH” manufactured by Union Carbide, “YP-50” manufactured by Tohto Kasei Co., Ltd., but are not limited thereto.

  Examples of the acrylic rubber include polymers or copolymers having at least one monomer component among acrylic acid, acrylic acid ester, methacrylic acid ester and acrylonitrile. Among them, glycidyl acrylate and glycidyl having a glycidyl ether group are mentioned. A copolymer acrylic rubber containing methacrylate is preferably used. The molecular weight of these acrylic rubbers is preferably 200,000 or more from the viewpoint of increasing the cohesive strength of the adhesive.

  Although the compounding quantity of the sheet agent (D) in the epoxy resin composition for adhesive sheets is not particularly limited, it is preferably 1 to 1000 parts by mass, more preferably 10 to 100 parts by mass of the epoxy resin (B). 500 parts by mass. If the blending amount of the sheeting agent (D) is 1000 parts by mass or more, the viscosity at the time of curing tends to be high and the moldability tends to be low, and if it is 1 part by mass or less, it tends to be difficult to form a sheet. .

[Other ingredients]
A curing agent other than the microcapsule type latent curing agent (C) can be blended with the epoxy resin composition for an adhesive sheet of the present embodiment, if necessary. As such a curing agent, in addition to those mentioned as examples of the amine-based curing agent and other epoxy resin curing agent (h1) contained in the particles as a starting material for forming the core (K), Any of those generally used as a curing agent for epoxy resins can be mentioned. In particular, at least one epoxy resin curing agent selected from the group consisting of acid anhydride curing agents, phenol curing agents, hydrazide curing agents, and guanidine curing agents is preferred.

  Acid anhydride curing agents include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, -3-chlorophthalic anhydride, -4-chlorophthalic anhydride, benzophenone anhydride Examples thereof include tetracarboxylic acid, succinic anhydride, methyl succinic anhydride, dimethyl succinic anhydride, dichlor succinic anhydride, methyl nadic acid, dodecyl succinic acid, chlorendec succinic anhydride, maleic anhydride and the like.

  Examples of the phenolic curing agent include phenol novolak, cresol novolak, and bisphenol A novolak.

  Examples of the hydrazide-based curing agent include succinic acid dihydrazide, adipic acid dihydrazide, phthalic acid dihydrazide, isophthalic acid dihydrazide terephthalic acid dihydrazide, p-oxybenzoic acid hydrazide, salicylic acid hydrazide, phenylaminopropionic hydrazide, maleic acid dihydrazide and the like.

  Examples of the guanidine-based curing agent include dicyandiamide, methylguanidine, ethylguanidine, propylguanidine, butylguanidine, dimethylguanidine, trimethylguanidine, phenylguanidine, diphenylguanidine, toluylguanidine and the like.

  In addition, the epoxy resin composition for an adhesive sheet of the present embodiment includes a high thermal conductive insulating filler (A), an epoxy resin (B), a microcapsule type latent curing agent (C), and a sheeting agent (D). The organic solvent (E) is preferably contained. By including the organic solvent (E), an adhesive sheet having high surface smoothness tends to be obtained, and since the filling rate of the high thermal conductive insulating filler can be increased, the thermal conductivity and electromagnetic shielding properties are high. There is a tendency to obtain films.

  Examples of the organic solvent (E) include hydrocarbons such as benzene, toluene, xylene, cyclohexane, mineral spirit, and naphtha; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; ethyl acetate, acetic acid-n-butyl, propylene Examples include esters such as glycol monomethyl ethyl ether acetate; alcohols such as methanol, isopropanol, n-butanol, butyl cellosolve, and butyl carbitol; water and the like.

  Moreover, when a plasticizer is blended in the epoxy resin composition for an adhesive sheet, an adhesive sheet with high flexibility and flexibility tends to be obtained. Examples of plasticizers include phthalic acid diesters such as dibutyl phthalate and di (2-ethylhexyl) phthalate; aliphatic dibasic acid esters such as di (2-ethylhexyl) adipate; and triphosphates such as tricresyl phosphate. Ester type; glycol ester type such as polyethylene glycol ester and the like. Examples of the resins include silicone resins and phenol resins.

  The method of mixing the epoxy resin composition for an adhesive sheet of the present embodiment is not particularly limited, but mixing with a non-bubbling kneader can be performed on the surface of a microcapsule-type latent curing agent or a surface-coated highly thermally conductive insulating filler. From the viewpoint of preventing damage.

  In the epoxy resin composition for an adhesive sheet of the present embodiment, a filler other than a bulking agent, a reinforcing material, and a high thermal conductive insulating filler, as long as its functions such as thermal conductivity, electromagnetic wave shielding property, and adhesiveness are not lowered. Other additives such as pigments and organic solvents can be contained. The content of other additives is preferably less than 30% by mass of the total amount of the epoxy resin composition for adhesive sheets.

[Adhesive sheet]
From the epoxy resin composition for adhesive sheets of this embodiment, an adhesive sheet can be produced by an existing method. For example, it is obtained by mixing a high thermal conductive insulating filler (A), an epoxy resin (B), a microcapsule type latent curing agent (C), a sheeting agent (D), and an organic solvent (E) with a non-bubbling kneader. The obtained varnish is applied to, for example, a peeling polyethylene terephthalate substrate having a thickness of 50 μm so that the solvent has a thickness of 30 μm after drying. Next, by drying the solvent, it is possible to obtain an adhesive sheet that is inactive at room temperature and exhibits adhesiveness by the action of the latent curing agent by heating.

  The method for curing the adhesive sheet of the present embodiment is not particularly limited, but can usually be cured at a temperature of 40 ° C. or higher and 300 ° C. or lower for 3 seconds or more and 1 week or less under pressure or without pressure.

  Although it does not restrict | limit especially as hardening temperature, The damage by the heat | fever to a to-be-adhered body can be avoided, so that it cures at low temperature. Moreover, the curing time can be shortened as the reaction is carried out at a higher temperature. From such a viewpoint, a preferable curing temperature is 50 ° C to 200 ° C, more preferably 60 ° C to 180 ° C, still more preferably 70 ° C to 150 ° C, and particularly preferably 80 ° C to 120 ° C.

  Moreover, a heat radiating member can be obtained from the adhesive sheet and metal piece of this Embodiment. As a manufacturing method of a heat radiating member, it can obtain by attaching an adhesive sheet by thermocompression-bonding to a metal piece at the temperature below the temperature which a hardening reaction starts, for example. Examples of the metal piece include copper and aluminum.

In order to describe the present embodiment in more detail, examples and comparative examples will be shown below. These examples specifically illustrate the description of the present embodiment and the effects obtained thereby. Thus, the present embodiment is not limited at all. Various characteristics in the following examples and comparative examples were measured according to the following methods.
(1) Epoxy equivalent The mass (g) of an epoxy resin containing 1 equivalent of an epoxy group, and was determined according to JIS K-7236.

(2) Total chlorine content of epoxy resin 1 g of a sample was dissolved in 25 mL of ethylene glycol monobutyl ether, and 25 mL of a 1N KOH propylene glycol solution was added thereto and boiled for 20 minutes, followed by titration with an aqueous silver nitrate solution.

(3) Total Chlorine Amount of Masterbatch Type Epoxy Resin Curing Agent Composition The masterbatch type epoxy resin curing agent composition was repeatedly washed and filtered using xylene until the epoxy resin disappeared. Next, the filtrate was distilled off under reduced pressure at 100 ° C. or lower to obtain an epoxy resin. 1-10 g of the obtained epoxy resin sample was precisely weighed so that the titration amount was 3-7 mL, dissolved in 25 mL of ethylene glycol monobutyl ether, and 25 mL of 1N KOH propylene glycol solution was added thereto and boiled for 20 minutes. After that, it was titrated with an aqueous silver nitrate solution.

(4) Diol terminal impurity component amount of epoxy resin The diol terminal impurity component of the epoxy resin was analyzed and quantified by the following method. Tosoh high performance liquid chromatography (AS-8021, detector UV-8020, hereinafter referred to as HPLC) and Novapack C-18 manufactured by Millipore Corporation were used as the column. The mobile phase was gradient from water / acetonitrile = 70/30 to 0/100. The detection wavelength was 254 nm. Separation conditions based on differences in both terminal structures were selected by HPLC analysis, and the separation liquid was fractionated using a switching valve. The separated separation liquid was distilled off under reduced pressure for each fraction, and the residue was analyzed by MS. Of MS spectra, those having a difference of 18 in the mass number of the reference peak were designated as a basic structural component with a smaller value of 18 and an impure component with a diol terminal as a larger value. The content of the diol terminal impure component with respect to the basic structural component in the epoxy resin was determined by the area ratio of the area indicating the intensity of the diol terminal impure component peak on the HPLC analysis chart and the peak intensity indicating the basic structural component.

(5) Average particle diameter 4 mg of the particle powder was placed in 32 g of a cyclohexane solution of 0.1% by mass surfactant (Mitsui Cytec Co., Ltd., “Aerosol OT-75”), and an ultrasonic cleaner (Honda Electronics Co., Ltd.). ) "MODEL W-211") and dispersed by ultrasonic irradiation for 5 minutes. The water temperature in the ultrasonic cleaner at this time was adjusted to 19 ± 2 ° C. A part of the obtained dispersion was taken, and the particle size distribution was measured with a particle size distribution meter (“HORIBA LA-920” manufactured by Horiba, Ltd.), and the average particle size was determined from the median diameter based on this.

(6) Infrared absorption characteristics of the surface of the shell (S) The masterbatch type epoxy resin curing agent was repeatedly washed and filtered with xylene until the epoxy resin disappeared, and then washed and filtered with cyclohexane until the xylene disappeared Was repeated. Then, cyclohexane was separated by filtration, cyclohexane was completely removed and dried at a temperature of 50 ° C. or lower, and the microcapsule type epoxy resin curing agent was separated from the masterbatch type epoxy resin curing agent composition.
The absorbance of the surface of the thus obtained microcapsule-type epoxy resin curing agent was measured using a Fourier transform infrared spectrophotometer (“FT / IR-410” manufactured by JASCO Corporation).

(7) Concentration ratio measurement of bonding group (x), (y), (z) A calibration curve was prepared in advance by the following procedure.
Model compound having a bonding group that absorbs infrared wave number ^{1630~1680cm -1 (x) (1)} , a model compound having a bonding group that absorbs infrared wave number ^{1680~1725cm -1 (y) (2)} , and wavenumber The following was used as the model compound (3) having a bonding group (z) that absorbs infrared rays of 1730 to 1755 cm ⁻¹ .

Using tetramethyl succinic acid nitrile as a standard substance, a calibration sample which was a mixture of this and each of model compounds (1), (2) and (3) was prepared. Using FT / IR-410 manufactured by JASCO Corporation, the absorbance of the calibration sample and the standard substance is measured, and the relationship between the area ratio of the infrared absorption band and the mass ratio of the inclusions is linearly determined from the measured values. A calibration curve was created by regression.
The model compounds (1), (2) and (3) and the tetramethyl succinic acid nitrile which is a standard substance were all made of Tokyo Chemical Reagent Grade.
Next, the microcapsule type epoxy resin curing agent separated from the masterbatch type epoxy resin curing agent composition in the same manner as in (6) was vacuum-dried at 40 ° C. to determine its mass.
The vacuum-cured microcapsule type epoxy resin curing agent was repeatedly washed and filtered with methanol until the epoxy resin curing agent disappeared, and the methanol was completely removed and dried at a temperature of 50 ° C. or less. Only separated. The shell was vacuum-dried at 40 ° C., the mass was measured, and a binding group concentration ratio measurement sample was obtained.
10 mg of tetramethyl succinonitrile as a standard substance was added to 3 g of the concentration ratio measurement sample, pulverized and mixed in an agate mortar, and the mixture was pulverized with 2 mg and 50 mg of KBr powder, and then FT / A tablet for IR measurement was prepared. Using this tablet, an infrared spectrum was obtained by a Fourier transform infrared spectrophotometer (“FT / IR-410” manufactured by JASCO Corporation).
The concentration of the bonding groups (x), (y), and (z) in the sample is obtained from the area of the obtained spectrum chart and a calibration curve prepared in advance, and the bonding groups per kg of the microcapsule type epoxy resin curing agent. The quantity and its concentration ratio were determined.

(8) Determination of presence or absence of ester bond in shell For the shell separated in the same manner as in (7), using Bruker DSX400 (magnetic field: 400 MHz), observation measurement nuclide 13C, pulse program CPSELECTICS, pulse condition The measurement was performed under the conditions of a repetition time of 5 seconds, a proton 90 degree pulse of 5.2 microseconds, a contact time of 1 millisecond, and magic angle spinning of 5000 Hz. Using the C13 nuclear magnetic resonance spectrum of methyl methacrylate polymer as a model composition, the ratio of the peak height due to the carbonyl carbon of the ester group appearing at 165 to 175 ppm and the peak height of the methylene chain appearing at 28 to 38 ppm is compared with the model compound. In the case of 1/10 or less, it was determined that there was no carbonyl carbon of the ester group, and based on this, the presence or absence of an ester bond was determined.

(9) Storage Stability of Masterbatch Type Epoxy Resin Curing Agent Composition The viscosity before and after storing the masterbatch type epoxy resin curing agent composition at 40 ° C. for 1 week was measured and evaluated by the viscosity increase ratio. When the rate of increase in viscosity after storage was 10 times or more or gelled, × was 5 times or more and less than 10 times, Δ was 2 times or more and less than 5 times, and ○ was less than 2 times. The viscosity was measured at 25 ° C. using a BM viscometer (“VISCOMETER” manufactured by TOKIMEC).

(10) Solvent resistance of curing agent composition for masterbatch type epoxy resin A sample prepared by mixing 80 parts of the curing agent composition for masterbatch type epoxy resin with 15 parts of toluene and 5 parts of methyl isobutyl ketone was prepared at 40 ° C. The sample was heated for 6 hours, and the viscosity of the sample after heating was measured. Those having a viscosity of 200 mPa · s or less are ◎, those having 200 to 1000 mPa · s are ○, those having 1000 to 20000 mPa · s are Δ, those having 20000 to 20000 mPa · s are ×, those having 20000 mPa · s or more are XX It was.

(11) Moisture resistance of the masterbatch type epoxy resin curing agent composition The masterbatch type epoxy resin curing agent composition is held at a constant temperature and humidity of 30 ° C and 85% for 6 hours and then stored at 40 ° C for 1 week. The viscosities before and after the measurement were measured and evaluated by the viscosity increase ratio. When the rate of increase in viscosity after storage was 10 times or more or gelled, × was 5 times or more and less than 10 times, Δ was 2 times or more and less than 5 times, and ○ was less than 2 times. The viscosity was measured at 25 ° C. using a BM viscometer.

(12) Varnish storage stability A solution (varnish) of the epoxy resin composition for an adhesive sheet is heated at 40 ° C. for 6 hours, and the viscosity of the sample after heating is less than 5 times that before heating. The case of doubling or more and less than 10 times was evaluated as Δ, and the case of doubling or 5 times was evaluated as x.

(13) Adhesive sheet storage stability The calorific value per unit mass before and after the adhesive sheet was stored at 40 ° C. for 1 week was measured with a differential scanning calorimeter (“DSC220” manufactured by SII), and the calorific value before storage. On the other hand, the case where the ratio of the calorific value after storage was 70% or more was evaluated as ◯, the case where it was 50% or more and less than 70% was evaluated as Δ, and the case where it was less than 50% was evaluated as ×.

(14) Thermal conductivity of cured adhesive sheet The thermal conductivity of the cured adhesive sheet was measured at room temperature by a laser flash method (“TC-7000” manufactured by ULVAC-RIKO). That is, from the measured thermal diffusivity α, specific heat Cp, and density σ, the thermal conductivity was obtained from the following equation, K = α × Cp × σ.

(15) Electrical insulation of cured adhesive sheet The volume resistivity of the cured adhesive sheet was measured according to JISK69ll.
The case where the volume resistivity was 1 × ^{10 10} Ω · cm or more was evaluated as “◯”, and the case where the volume resistivity was less than 1 × ^{10 10} Ω · cm was evaluated as “x”.

(16) Surface smoothness of cured adhesive sheet When the surface of the cured adhesive sheet is visually observed, ◯ indicates that it is glossy, x indicates that it is not glossy, and Δ indicates that it is glossy but aggregates are observed. did.

(17) Adhesiveness of cured adhesive sheet The uncured adhesive sheet is sandwiched between two test pieces (25 mm x 100 mm x 1.6 mm) so that the adhesion area is 25 mm x 10 mm, and a hydraulic molding machine (manufactured by Toho Machinery Co., Ltd., "TM-10 )) And heat-cured while applying a pressure of 1 kg / cm ² to obtain a shear adhesion test piece. It measured according to JIS-K6850 using the obtained test piece. 5N / mm ² or more when ○, 0.5N / mm ² or more 5N / mm ² less than the case △, and as × when less than 0.5 N / mm ^2.

(18) Tensile strength of cured adhesive sheet A film having a width of 10 mm and a thickness of 50 microns was measured with a tensile tester (“AGS-H” manufactured by Shimadzu Corporation) at a rate of 2 mm / min, and the strength was 200 gf / cm. The above case was marked with ◯, the case of 50 gf / cm or more and less than 200 gf / cm with Δ, and the case of less than 50 gf / cm with x.

[Preparation of metal powder coated with organic resin]
To a 1000 mL three-necked flask, aluminum paste (M601 manufactured by Asahi Kasei Chemicals Corporation, metal content 65.2%, average particle size 11 μm) and mineral spirit 400 g were added, stirred while introducing nitrogen gas, and the temperature inside the system The temperature was raised to 80 ° C. Next, 0.375 g of acrylic acid was added and stirring was continued at 80 ° C. for 30 minutes. Next, 7.5 g of trimethylolpropane trimethacrylate and 0.75 g of azobisisobutyronitrile were added and polymerized at 80 ° C. for 5 hours. After completion of the polymerization, the mixture was allowed to cool to room temperature, and the slurry was filtered to obtain a paste (AL1) containing organic resin-coated aluminum. The non-volatile content (based on JIS-K-5910) of the paste (AL1) was 51.0% by mass. The amount of the coating resin with respect to 100 parts by mass of the aluminum metal content was 11.4 parts by mass. From the results of the amount of aluminum metal and the amount of coating resin, it is estimated that 99% or more of acrylic acid, trimethylolpropane trimethacrylate, and azobisisobutyronitrile adhered to the aluminum metal surface.

[Production Example 1-1] (Production of amine-based curing agent 1)
Bisphenol A type epoxy resin (epoxy equivalent 185 g / equivalent, total chlorine amount 1400 ppm, hereinafter referred to as “epoxy resin (e1) -1”) 1.5 equivalent and 2-ethyl-4-methylimidazole 1 equivalent (converted to active hydrogen) ) Was reacted at 80 ° C. in a 1/1 mixed solvent of n-butanol and toluene (resin content: 50%). Then, 2-ethyl-4-methylimidazole was distilled off with the solvent under reduced pressure until the content was less than 10 ppm, and a solid amine adduct was obtained at 25 ° C.
99.1 parts by mass of the amine adduct obtained by the above method was melted, and 0.9 parts by mass of 2-ethyl-4-methylimidazole was uniformly mixed therewith to obtain an amine curing agent 1.

[Production Example 1-2] (Production of amine-based curing agent 2)
1 equivalent of epoxy resin (e1) -1, 1 equivalent of bisphenol A type epoxy resin (epoxy equivalent 470 g / equivalent, total chlorine amount 1300 ppm, hereinafter referred to as “epoxy resin (e1) -2”) and 2 equivalents of triethylenetetramine The reaction was carried out at 80 ° C. in a 1/2 mixed solvent of 2-propanol and toluene (resin content: 50%). Thereafter, the solvent was distilled off under reduced pressure.
The amine curing agent 2 obtained by the above method was solid at 25 ° C., mainly composed of an amine adduct, and contained 0.3% by mass of triethylenetetramine.

[Production Example 1-3] (Production of amine-based curing agent 3)
Epoxy resin (e1) -2 0.5 equivalent, cresol novolac type epoxy resin (epoxy equivalent 215 g / equivalent, total chlorine amount 1500 ppm) 1 equivalent, N-methylpiperazine 1.8 equivalent, 2-propanol / toluene / propylene Glycol monomethyl ether was reacted at 80 ° C. in a 1/1/1 mixed solvent (resin content: 50%). Thereafter, the solvent was distilled off under reduced pressure.
The amine curing agent 3 obtained by the above method was solid at 25 ° C., mainly composed of an amine adduct, and contained 0.8% by mass of N-methylpiperazine.

[Production Example 1-4] (Production of amine-based curing agent 4)
Reaction of 1.5 equivalents of bisphenol A type epoxy resin (e1) -1 and 1.2 equivalents of 2-methylimidazole in a 1/1 mixed solvent of n-butanol and toluene (resin content 50%) at 80 ° C. I let you. Thereafter, the solvent was distilled off under reduced pressure.
The amine-based curing agent 4 obtained by the above method was solid at 25 ° C., mainly composed of an amine adduct, and contained 0.4% by mass of 2-methylimidazole.

[Production Example 1-5] (Production of amine-based curing agent 5)
1 equivalent of bisphenol A type epoxy resin (e1) -1 and 0.7 equivalent of 2-methylimidazole were reacted at 80 ° C. in a 1/1 mixed solvent of n-butanol and toluene (resin content: 50%). . Thereafter, the solvent was distilled off under reduced pressure.
The amine-based curing agent 5 obtained by the above method was solid at 25 ° C. and contained an amine adduct as a main component and contained 0.5% by mass of 2-methylimidazole.

[Production Example 2-1] [Preparation 1 of Masterbatch Type Epoxy Resin Curing Agent Composition]
The amine-based curing agent 1 was pulverized using a swirling pulverizer to obtain particles c-1 (core) having a solid average particle diameter of 2.5 μm at 25 ° C. The water content in the particles c-1 was 0.6 parts by mass with respect to 100 parts by mass of the particles c-1.
Bisphenol A type liquid epoxy resin (epoxy equivalent 175 g / equivalent, diol terminal impure component / basic structure component = 0.08), total chlorine amount 1400 ppm, hereinafter referred to as “epoxy resin (e3) -1”. ) 100 parts by mass of the particle c-1, 1.5 parts by mass of water and 7 parts by mass of tolylene diisocyanate (TDI) were added to 200 parts by mass, and the reaction was continued for 3 hours while stirring at 40 ° C. Then, it was made to react at 50 degreeC for 8 hours, and the hardening | curing agent composition 1 for masterbatch type epoxy resins was obtained.
When the microcapsule type epoxy resin curing agent was separated from the master batch type epoxy resin curing agent composition 1 obtained by the above method using xylene and the surface thereof was analyzed by FT-IR measurement, 1630 to 1680 cm ^{−. 1} and wave numbers from 1680 to 1725 cm ⁻¹ and from 1730 to 1755 cm ⁻¹ were confirmed to have absorption.
In addition, using the analysis charts of the model compounds (1), (2), and (3) and the calibration curve prepared from the standard substance and the model compound, the bonding groups (x), (y), (z) in the shell The content and the concentration ratio were measured, and the results are shown in Table 1.
Further, C13 nuclear magnetic resonance spectrum measurement of the separated shell was performed, and it was confirmed that the resin contained in the shell did not have an ester bond.

[Production Example 2-2] [Preparation 2 of Masterbatch Type Epoxy Resin Curing Agent Composition]
The amine curing agent 2 was pulverized using a (swivel pulverizer) to obtain particles c-2 having an average particle diameter of 2.0 μm. The water content in the particles c-2 was 1.2 parts by mass with respect to 100 parts by mass of the particles c-2.
200 parts by mass of the same epoxy resin (e3) -1 used in Production Example 2-1, 100 parts by mass of the particle c-2, 1.5 parts by mass of water, polymethylenephenylene polyisocyanate (MR manufactured by Nippon Polyurethane Co., Ltd.) -200) 5 parts by mass was added, and a masterbatch type epoxy resin curing agent composition 2 was obtained in the same manner as in Preparation 1 of the masterbatch type epoxy resin curing agent composition.
The surface of the microcapsule type epoxy resin curing agent 2 obtained by the above method has absorption at wave numbers 1630 to 1680 cm ⁻¹ , wave numbers 1680 to 1725 cm ⁻¹ and 1730 to 1755 cm ⁻¹ , and has an ester bond in the shell. It was confirmed not to. Further, the contents of the bonding groups (x), (y) and (z) of the shell and the concentration ratio thereof were as shown in Table-1.

[Production Example 2-3] [Preparation 3 of curing agent composition for masterbatch type epoxy resin]
The amine curing agent 3 was pulverized using a (swivel pulverizer) to obtain particles c-3 having an average particle diameter of 1.9 μm. The water content in the particles c-3 was 0.7 parts by mass with respect to 100 parts by mass of the particles c-3.
The same epoxy resin (e3) -1 as used in Production Example 2-1 200 parts by mass, particle c-3 100 parts by mass, water 1.0 part by mass, 4,4'-diphenylmethane diisocyanate (MDI) 5 parts by mass The reaction was continued for 3 hours with stirring at 40 ° C. Thereafter, 0.5 part by mass of the cyclic borate ester compound (L) was added, and further reacted at 50 ° C. for 8 hours to obtain a masterbatch type epoxy resin curing agent 3.
The surface of the microcapsule type epoxy resin curing agent 3 obtained by the above method has absorption at wave numbers 1630 to 1680 cm ⁻¹ , wave numbers 1680 to 1725 cm ⁻¹ and 1730 to 1755 cm ⁻¹ , and has an ester bond in the shell. It was confirmed not to. Further, the contents of the bonding groups (x), (y) and (z) of the shell and the concentration ratio thereof were as shown in Table-1.

[Production Example 2-4] [Preparation 4 of Masterbatch Type Curing Agent Composition for Epoxy Resin 4]
The amine-based curing agent 4 was pulverized using a rotary pulverizer to obtain particles c-4 having an average particle size of 3.5 μm. The water content in this c-4 was 1.0 part by mass with respect to 100 parts by mass of the particle c-4.
200 parts by mass of the same epoxy resin (e3) -1 used in Production Example 2-1, 100 parts by mass of particles c-4, 0.5 parts by mass of water, polymethylenephenylene polyisocyanate (MR-manufactured by Nippon Polyurethane Co., Ltd.) 200) 7 parts by mass were added, and a masterbatch type epoxy resin curing agent composition 4 was obtained in the same manner as in Preparation 1 of the masterbatch type epoxy resin curing agent composition.
The surface of the microcapsule type epoxy resin curing agent 4 obtained by the above method has absorption at wave numbers 1630 to 1680 cm ⁻¹ , wave numbers 1680 to 1725 cm ⁻¹ and 1730 to 1755 cm ⁻¹ , and has an ester bond in the shell. It was confirmed not to. Further, the contents of the bonding groups (x), (y) and (z) of the shell and the concentration ratio thereof were as shown in Table-1.

[Production Example 2-5] [Preparation 5 of curing agent composition for masterbatch type epoxy resin]
The amine curing agent 5 was pulverized using a swirling pulverizer to obtain particles c-5 having an average particle diameter of 15.5 μm. The water content in the particles c-5 was 4.1 parts by mass with respect to 100 parts by mass of c-5.
To 200 parts by mass of the same epoxy resin (e3) -1 used in Production Example 2-1, 100 parts by mass of particles c-5, 0.5 parts by mass of water, and 3 parts by mass of tolylene diisocyanate (TDI) are added. Masterbatch type epoxy resin curing agent composition 5 was obtained in the same manner as in Preparation 1 of masterbatch type epoxy resin curing agent composition.
The surface of the microcapsule type epoxy resin curing agent 5 obtained by the above method has absorption at wave numbers 1630 to 1680 cm ⁻¹ , wave numbers 1680 to 1725 cm ⁻¹ and 1730 to 1755 cm ⁻¹ , and has an ester bond in the shell. It was confirmed not to. Further, the contents of the bonding groups (x), (y) and (z) of the shell and the concentration ratio thereof were as shown in Table-1.

[Production Example 2-6] [Preparation 6 of Masterbatch Type Epoxy Resin Curing Agent Composition]
The amine curing agent 5 was pulverized using a swirling pulverizer to obtain particles having an average particle diameter of 3.1 μm. The particles c-6 were dried, and the water content was adjusted to 2.5 parts by mass with respect to 100 parts by mass of c-6, and designated c-7.
100 parts by mass of epoxy resin curing agent particles c-7, 200 parts by mass of the same epoxy resin (e3) -1 used in Production Example 2-1, manufactured by Mitsui Takeda Chemical Co., Ltd. which is a polyester type polyol as an active hydrogen compound 1.0 part by mass of Diol-400, 7 parts by mass of 4,4′-diphenylmethane diisocyanate (MDI) was added, and the reaction was continued for 3 hours while stirring at 40 ° C. Thereafter, 0.2 part by mass of the cyclic borate ester compound (L) was added and further reacted at 50 ° C. for 8 hours to obtain a curing agent 6 for masterbatch type epoxy resin.
Microcapsule type epoxy resin curing agent 6 obtained by the above method, the surface and the wave number 1630～1680Cm ^-1 wavenumber 1680～1725Cm ^-1, has an absorption in 1730～1755Cm ^-1, has an ester bond in the shell It was confirmed. Further, the contents of the bonding groups (x), (y) and (z) of the shell and the concentration ratio thereof were as shown in Table-1.

[Production Example 2-7] [Preparation of curing agent composition for masterbatch type epoxy resin 7]
The amine curing agent 5 was pulverized using a swirling pulverizer to obtain particles c-8 having an average particle diameter of 15.5 μm. The water content in the particles c-8 was 3.2 parts by mass with respect to 100 parts by mass of c-8.
To 200 parts by mass of the same epoxy resin (e3) -1 as used in Production Example 2-1, 100 parts by mass of particles c-8, 8 parts by mass of water, and 20 parts by mass of tolylene diisocyanate (TDI) are added, and a master batch. The curing agent composition 7 for a masterbatch type epoxy resin was obtained in the same manner as in Preparation 1 of the curing agent composition for a type epoxy resin.
The surface of the microcapsule type epoxy resin curing agent 7 obtained by the above method has absorption at wave numbers 1630 to 1680 cm ⁻¹ , wave numbers 1680 to 1725 cm ⁻¹ and 1730 to 1755 cm ⁻¹ , and has an ester bond in the shell. It was confirmed not to. Further, the contents of the bonding groups (x), (y) and (z) of the shell and the concentration ratio thereof were as shown in Table-1.

[Examples 1-7]
Organic resin-coated aluminum paste (AL1), phenoxy resin ("PKHH" manufactured by Union Carbide), bisphenol A type epoxy resin (AER250 manufactured by Asahi Kasei Chemicals Co., Ltd.), ethyl acetate, hardener composition for masterbatch type epoxy resin The one-component epoxy resin composition obtained by blending at a ratio shown in Table 2 was applied onto a polyester film, and ethyl acetate was removed by drying at 70 ° C. to obtain an uncured adhesive sheet. The properties of the obtained uncured adhesive sheet are shown in Table 2.
The obtained uncured adhesive sheet was heat-cured at 180 ° C. for 1 hour to obtain a cured adhesive sheet. Properties of the obtained cured adhesive sheet are shown in Table 2.

[Example 8]
After mixing paste (AL1) containing resin-coated aluminum, phenoxy resin (“PKHH” manufactured by Union Carbide), bisphenol A type epoxy resin (AER250 manufactured by Asahi Kasei Chemicals Co., Ltd.), and ethyl acetate at a ratio shown in Table 2, acetic acid is mixed. A one-part epoxy resin composition obtained by blending a hardener composition for a masterbatch type epoxy resin into a resin composition obtained by distilling off ethyl is applied on a polyester film with an applicator and is uncured. An adhesive sheet was obtained. The properties of the obtained uncured adhesive sheet are shown in Table 2.
The obtained uncured adhesive sheet was heat-cured at 180 ° C. for 1 hour to obtain a cured adhesive sheet. Properties of the obtained cured adhesive sheet are shown in Table 2.

[Examples 9 and 10]
A cured adhesive sheet was obtained in the same manner as in Example 5 and Example 7 except that the curing condition of the adhesive sheet was changed to 120 ° C. for 1 hour. The properties of the obtained cured adhesive sheet are shown in Table-3.

[Comparative Examples 1-4]
A one-component epoxy resin composition was obtained in the same manner as in Example 1-8 at the ratio shown in Table-2. Next, it was removed by drying in the same manner as in Example 1-8 to obtain an uncured adhesive sheet, and a cured adhesive sheet was obtained in the same manner as in Example. Their characteristics are shown in Table 2.

[Comparative Example 5]
Examples except that AITI (2,4-diamino-6- (2-methyl-1-imidazolylethyl) -1,3,5-triazine isocyanuric acid adduct) was used as a non-microcapsule type latent curing agent A one-component epoxy resin composition was obtained in the same manner as 9 and 10. Further, a cured adhesive sheet was obtained in the same manner as in Examples 9 and 10. The properties of the obtained cured adhesive sheet are shown in Table-3.

[Application Example 1, Application Comparison Example]
A heat-dissipating aluminum fin was bonded to the back surface of the single-sided printed wiring board on which the LED was mounted using the uncured adhesive sheet prepared in Example 1 and Comparative Example 4, and the LED was turned on. When the surface temperature of the printed wiring board around the LED after 30 minutes was measured, the one using the sheet of Example 1 was 20 ° C. lower than the one using the sheet of Comparative Example 4.

[Application Example 2]
When the cured adhesive sheet prepared in Example 1 was tested for electromagnetic wave shielding at 100 MHz while grounding using a TR4131 electromagnetic shielding test device manufactured by Advantest Corporation, it showed an attenuation factor of 30 dB and confirmed the electromagnetic shielding properties. did.

  As is apparent from the results in Tables 2 and 3, the adhesive sheet formed using the epoxy resin composition for adhesive sheets of the present embodiment is excellent in storage stability, and is obtained by heat-curing the adhesive sheet. The cured sheet was high in thermal conductivity and electrical insulation and excellent in adhesiveness.

ADVANTAGE OF THE INVENTION According to this invention, the adhesive sheet excellent in storage stability, the adhesive sheet hardened | cured material with high heat conductivity and electrical insulation, and excellent adhesiveness, and the epoxy resin composition for adhesive sheets suitable for these manufacture Can be provided.
By using the adhesive sheet of this invention, the heat radiating member and electromagnetic wave shielding material excellent in heat dissipation can be provided.

Claims (8)

A high thermal conductive insulating filler (A);
Epoxy resin (B);
A microcapsule-type latent curing agent (C);
Sheeting agent (D);
An epoxy resin composition for an adhesive sheet containing   The epoxy resin composition for an adhesive sheet according to claim 1, wherein the high thermal conductive insulating filler (A) is a metal powder coated with an organic resin.   The epoxy resin composition for adhesive sheets of Claim 2 whose metal seed | species of the said metal powder is aluminum. The microcapsule-type latent curing agent (C) is a microcapsule-type latent curing agent having at least a core (K) and a shell (S) that covers the core (K),
Said shell (S) is bonded group that absorbs infrared wave number 1630～1680Cm ^-1 at least on its surface (x), binding group that absorbs infrared wave number 1680~1725cm ^-1 (y), and the wave number 1730~1755cm ^-1 having a bonding group (z) that absorbs infrared rays,
The ratio (Cx / (Cx + Cy + Cz)) of the concentration (Cx) of the bonding group (x) in the shell (S) to the total concentration (Cx + Cy + Cz) of the bonding groups (x), (y) and (z) is The epoxy resin composition for adhesive sheets of any one of Claims 1-3 which is 0.50 or more and less than 0.75.   The epoxy resin composition for adhesive sheets according to any one of claims 1 to 4, further comprising an organic solvent (E).   The adhesive sheet formed from the epoxy resin composition for adhesive sheets of any one of Claims 1-5.   A cured adhesive sheet obtained by heat-curing the adhesive sheet according to claim 6.   A heat dissipation member comprising the adhesive sheet according to claim 6 and a metal piece.