CN104284957A - Heat-conductive pressure-sensitive adhesive composition, heat-conductive pressure-sensitive-adhesive sheet-like molded article, production method thereof, and electronic device - Google Patents

Abstract

Polymerization and crosslinking reactions are carried out in a mixed composition containing a specified amount of (meth)acrylate polymer (A1), (meth)acrylate monomer (α1) and A (meth)acrylic resin composition (A) of a polyfunctional monomer (D) having a polymerizable unsaturated bond, a BET specific surface area of 1.0 m ² /g or more, and a thermally conductive filler not subjected to titanate treatment (B1), titanate-treated thermally conductive filler (B2), thermally conductive filler (B3) other than thermally conductive filler (B1) and thermally conductive filler (B2), and phosphoric acid ester (C), all The polymerization reaction is the polymerization reaction of (meth)acrylate monomer (α1) and polyfunctional monomer (D), and the cross-linking reaction is the (meth)acrylate polymer (A1) and/or containing source Provide a heat-conductive pressure-sensitive adhesive composition that has flame retardancy and suppresses bleeding of liquid components by cross-linking reaction of polymers derived from structural units of (meth)acrylate monomers (α1) and heat-conductive pressure-sensitive-adhesive sheet-like moldings.

Description

Heat-conductive pressure-sensitive adhesive composition, heat-conductive pressure-sensitive-adhesive sheet-like molded article, production method thereof, and electronic device

technical field

The present invention relates to a heat-conductive pressure-sensitive adhesive composition, a heat-conductive pressure-sensitive-adhesive sheet-shaped molded article, their production method, and a heat-conductive pressure-sensitive adhesive composition or the heat-conductive pressure-sensitive adhesive. Electronic equipment of permanent sheet-like moldings.

Background technique

In recent years, electronic components such as plasma displays (PDPs) and integrated circuit (IC) chips have increased their heat generation as their performance has increased. As a result, there is a need to take countermeasures against malfunctions caused by temperature rises in electronic components or electronic equipment including electronic components. As a countermeasure against malfunctions caused by temperature rise of electronic components and the like, a method of attaching a radiator such as a metal radiator, a radiator plate, or a radiator fin to a heat generating body is generally employed. In addition, when fixing the heat sink in the heat sink, in order to efficiently conduct heat from the heat sink to the heat sink, a composition having not only thermal conductivity but also pressure-sensitive adhesive properties (hereinafter referred to as "thermal conductivity") is generally used. pressure-sensitive adhesive composition"), a sheet-like member (hereinafter referred to as "heat-conductive pressure-sensitive-adhesive sheet-like molded article").

Of course, excellent thermal conductivity is required for the heat conductive pressure-sensitive adhesive composition and heat conductive pressure-sensitive-adhesive sheet-like molded article, and flame retardancy is also required depending on the application. As a technique related to a heat conductive pressure-sensitive adhesive composition excellent in flame retardancy and a heat conductive pressure-sensitive-adhesive sheet-like molded article, for example, Patent Document 1 describes a technique of adding a phosphate ester as a flame retardant.

prior art literature

patent documents

Patent Document 1: Japanese Patent Application Laid-Open No. 2011-111544.

Contents of the invention

As described above, in order to impart flame retardancy to the heat conductive pressure-sensitive adhesive composition and the heat conductive pressure-sensitive-adhesive sheet-like molded article, it is considered to add a flame retardant. However, when using a thermally conductive pressure-sensitive adhesive composition and a thermally conductive pressure-sensitive-adhesive sheet-like molded article, when they are crushed, if a large amount of liquid flame retardant such as phosphoric acid ester is added, there will be a liquid flame retardant. Concern about leakage of ingredients.

Therefore, an object of the present invention is to provide a heat conductive pressure-sensitive adhesive composition and a heat conductive pressure-sensitive adhesive sheet-like molded article having flame retardancy and suppressed bleeding of liquid components, and methods for producing them, An electronic device including the heat conductive pressure-sensitive adhesive composition or the heat conductive pressure-sensitive-adhesive sheet-like molded article.

The first aspect of the present invention is a heat-conductive pressure-sensitive adhesive composition (F) obtained by performing polymerization reaction and crosslinking reaction in the following mixed composition,

The mixed composition contains 100 parts by mass of a (meth)acrylic resin composition (A), 200 parts by mass or more of a thermally conductive filler (B1) that has a BET specific surface area of 1.0 m ² /g or more and has not been treated with titanate 450 parts by mass or less, titanate-treated thermally conductive filler (B2) 120 to 500 parts by mass, thermally conductive filler (B3) other than thermally conductive filler (B1) and thermally conductive filler (B2) The (meth)acrylic resin composition (A) contains (meth)acrylate polymer (A1), a (meth)acrylate monomer (α1) and a polyfunctional monomer (D) having a plurality of polymerizable unsaturated bonds,

The polymerization reaction is a polymerization reaction of a (meth)acrylate monomer (α1) and a polyfunctional monomer (D) having a plurality of polymerizable unsaturated bonds, and the crosslinking reaction is a (meth)acrylate Crosslinking reaction of polymer (A1) and/or polymer comprising structural units derived from (meth)acrylate monomer (α1).

In this specification, "(meth)acryl" means "acryl and/or methacryl". In addition, the term "thermally conductive filler" means that by adding it, the thermal conductivity of the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive-adhesive sheet-like molded article (G) described later can be improved. , Fillers with a thermal conductivity of 0.5W/m・K or more. In addition, "titanate treatment" refers to surface treatment using a titanate-based coupling agent. In addition, "polymerization reaction of (meth)acrylate monomer (α1) and polyfunctional monomer (D) having a plurality of polymerizable unsaturated bonds" means (meth)acrylate monomer (α1) and Copolymerization reaction of polyfunctional monomer (D) having multiple polymerizable unsaturated bonds, polymerization reaction of (meth)acrylate monomer (α1), and polyfunctionality having multiple polymerizable unsaturated bonds One or more polymerization reactions in the polymerization reactions of the monomer (D). In addition, "the crosslinking reaction of the (meth)acrylate polymer (A1) and/or the polymer containing the structural unit derived from the (meth)acrylate monomer (α1)" means that (meth)acrylic acid Crosslinking reactions between ester polymers (A1), crosslinking reactions between polymers comprising structural units derived from (meth)acrylate monomers (α1), and (meth)acrylate polymers ( A1) One or more crosslinking reactions in a crosslinking reaction with a polymer comprising a structural unit derived from a (meth)acrylate monomer (α1). It should be noted that "a polymer comprising a structural unit derived from a (meth)acrylate monomer (α1)" includes a polymer obtained by a polymerization reaction between (meth)acrylate monomers (α1), and A polymer obtained by copolymerization of a (meth)acrylate monomer (α1) and a polyfunctional monomer (D) having a plurality of polymerizable unsaturated bonds.

A second aspect of the present invention is a heat-conductive pressure-sensitive-adhesive sheet-shaped molded article (G), which is formed after molding the following mixed composition into a sheet or simultaneously with molding the mixed composition into a sheet, It is formed by polymerization and crosslinking reactions,

The mixed composition contains 100 parts by mass of a (meth)acrylic resin composition (A), 200 parts by mass or more of a thermally conductive filler (B1) that has a BET specific surface area of 1.0 m ² /g or more and has not been treated with titanate 450 parts by mass or less, titanate-treated thermally conductive filler (B2) 120 to 500 parts by mass, thermally conductive filler (B3) other than thermally conductive filler (B1) and thermally conductive filler (B2) The (meth)acrylic resin composition (A) contains (meth)acrylate polymer (A1), a (meth)acrylate monomer (α1) and a polyfunctional monomer (D) having a plurality of polymerizable unsaturated bonds,

The polymerization reaction is a polymerization reaction of a (meth)acrylate monomer (α1) and a polyfunctional monomer (D) having a plurality of polymerizable unsaturated bonds, and the crosslinking reaction is a (meth)acrylate Crosslinking reaction of polymer (A1) and/or polymer comprising structural units derived from (meth)acrylate monomer (α1).

A third aspect of the present invention is a method for producing a heat-conductive pressure-sensitive adhesive composition (F), which includes a step of preparing a mixed composition, and a step of performing a polymerization reaction and a crosslinking reaction in the mixed composition,

The mixed composition contains 100 parts by mass of a (meth)acrylic resin composition (A), 200 parts by mass or more of a thermally conductive filler (B1) that has a BET specific surface area of 1.0 m ² /g or more and has not been treated with titanate 450 parts by mass or less, titanate-treated thermally conductive filler (B2) 120 to 500 parts by mass, thermally conductive filler (B3) other than thermally conductive filler (B1) and thermally conductive filler (B2) The (meth)acrylic resin composition (A) contains (meth)acrylate polymer (A1), a (meth)acrylate monomer (α1) and a polyfunctional monomer (D) having a plurality of polymerizable unsaturated bonds,

The polymerization reaction is a polymerization reaction of a (meth)acrylate monomer (α1) and a polyfunctional monomer (D) having a plurality of polymerizable unsaturated bonds, and the crosslinking reaction is a (meth)acrylate Crosslinking reaction of polymer (A1) and/or polymer comprising structural units derived from (meth)acrylate monomer (α1).

A fourth aspect of the present invention is a method for producing a heat-conductive pressure-sensitive-adhesive sheet-like molded article (G), which includes the steps of preparing a mixed composition, forming the mixed composition into a sheet, or after The process of performing polymerization reaction and crosslinking reaction while forming the mixed composition into a sheet,

The mixed composition contains 100 parts by mass of a (meth)acrylic resin composition (A), 200 parts by mass or more of a thermally conductive filler (B1) that has a BET specific surface area of 1.0 m ² /g or more and has not been treated with titanate 450 parts by mass or less, titanate-treated thermally conductive filler (B2) 120 to 500 parts by mass, thermally conductive filler (B3) other than thermally conductive filler (B1) and thermally conductive filler (B2) The (meth)acrylic resin composition (A) contains (meth)acrylate polymer (A1), a (meth)acrylate monomer (α1) and a polyfunctional monomer (D) having a plurality of polymerizable unsaturated bonds,

The polymerization reaction is a polymerization reaction of a (meth)acrylate monomer (α1) and a polyfunctional monomer (D) having a plurality of polymerizable unsaturated bonds, and the crosslinking reaction is a (meth)acrylate Crosslinking reaction of polymer (A1) and/or polymer comprising structural units derived from (meth)acrylate monomer (α1).

In the above-mentioned first to fourth aspects of the present invention, it is preferable that the thermally conductive filler (B1) has a BET specific surface area of 1.0 m ² /g or more, is not subjected to titanate treatment, and is selected from metal hydroxides and metal oxides. At least one filler in the material, the thermally conductive filler (B2) is a metal hydroxide treated with titanate, and the thermally conductive filler (B3) is other than the thermally conductive filler (B1) and the thermally conductive filler (B2) At least one filler selected from the group consisting of metal hydroxides, metal oxides and carbon-containing conductive fillers, more preferably the thermally conductive filler (B1) has a BET specific surface area of 1.0m ² /g or more without titanic acid Ester-treated, at least one filler selected from aluminum hydroxide and alumina, the thermally conductive filler (B2) is titanate-treated aluminum hydroxide, and the thermally conductive filler (B3) is a filler other than the thermally conductive filler (B1 ) and thermally conductive filler (B2), at least one filler selected from aluminum hydroxide, aluminum oxide, and expanded graphite.

In addition, the (meth)acrylic resin composition (A) preferably contains (meth)acrylate polymer (A1) 5% by mass to 25% by mass and (meth)acrylate monomer (α1) 74.8% by mass or more 94.8% by mass or less, and 0.2% by mass or more and 13% by mass or less of the polyfunctional monomer (D) having a plurality of polymerizable unsaturated bonds.

A fifth aspect of the present invention is an electronic device comprising a radiator and the heat conductive pressure-sensitive adhesive composition (F) of the first aspect of the present invention bonded to the radiator, or comprising a radiator and a bonded The thermally conductive pressure-sensitive-adhesive sheet-like molded article (G) of the said 2nd aspect of this invention in this radiator.

According to the present invention, it is possible to provide a thermally conductive pressure-sensitive adhesive composition having excellent flame retardancy and suppressed bleeding, a thermally conductive pressure-sensitive-adhesive sheet-shaped molded article, a method for producing them, and a thermally conductive pressure-sensitive adhesive composition having the thermally conductive pressure-sensitive adhesive composition. An electronic device using a sensitive adhesive composition or the heat-conductive pressure-sensitive-adhesive sheet-like molded body.

Detailed ways

1. Heat-conductive pressure-sensitive adhesive composition (F), heat-conductive pressure-sensitive-adhesive sheet-like molded article (G)

The heat conductive pressure-sensitive adhesive composition (F) of the present invention is a composition obtained by performing at least a polymerization reaction and a crosslinking reaction in the following mixed composition,

The mixed composition contains a (meth)acrylic resin composition ( ^A ), a thermally conductive filler (B1) (hereinafter sometimes simply referred to as "thermally conductive filler (B1)"), titanate-treated thermally conductive filler (B2) (hereinafter sometimes simply referred to as "thermally conductive filler (B2)"), except for thermally conductive filler (B1) and thermally conductive A thermally conductive filler (B3) other than the filler (B2) (hereinafter sometimes simply referred to as "thermally conductive filler (B3)"), and a phosphoric acid ester (C), the (meth)acrylic resin composition (A) Contains (meth)acrylate polymer (A1), (meth)acrylate monomer (α1), and polyfunctional monomer (D) having multiple polymerizable unsaturated bonds (hereinafter sometimes simply referred to as " polyfunctional monomer (D)"),

The polymerization reaction is the copolymerization reaction of (meth)acrylate monomer (α1) and multifunctional monomer (D), the polymerization reaction of (meth)acrylate monomer (α1), and the multifunctional monomer Polymerization reaction of at least any one of the polymerization reactions of the body (D), the crosslinking reaction is a crosslinking reaction between (meth)acrylate polymers (A1), including Crosslinking reaction between polymers of structural units of monomer (α1), and polymerization of (meth)acrylate polymer (A1) with structural units derived from (meth)acrylate monomer (α1) The crosslinking reaction of at least any one of the crosslinking reactions of the substance.

In addition, the heat-conductive pressure-sensitive-adhesive sheet-like molded article (G) of the present invention is formed by at least performing polymerization reaction and Formed body formed by cross-linking reaction,

The polymerization reaction is the copolymerization reaction of (meth)acrylate monomer (α1) and multifunctional monomer (D), the polymerization reaction of (meth)acrylate monomer (α1), and the multifunctional monomer Polymerization reaction of at least any one of the polymerization reactions of the body (D), the crosslinking reaction is a crosslinking reaction between (meth)acrylate polymers (A1), including Crosslinking reaction between polymers of structural units of monomer (α1), and polymerization of (meth)acrylate polymer (A1) with structural units derived from (meth)acrylate monomer (α1) The crosslinking reaction of at least any one of the crosslinking reactions of the substance.

The materials constituting such a heat conductive pressure-sensitive adhesive composition (F) and heat conductive pressure-sensitive-adhesive sheet-like molded article (G) are described below.

＜(Meth)acrylic resin composition (A)＞

The (meth)acrylic resin composition (A) used in the present invention contains a (meth)acrylate polymer (A1), a (meth)acrylate monomer (α1), and a polyfunctional monomer (D) . In addition, when obtaining a heat conductive pressure-sensitive-adhesive composition (F) and a heat conductive pressure-sensitive-adhesive sheet-shaped molded object (G), polymerization reaction and crosslinking reaction proceed as mentioned above. By performing this polymerization reaction and crosslinking reaction, a polymer containing a structural unit derived from a (meth)acrylate monomer (α1) and a polyfunctional monomer (D) and a (meth)acrylate polymer (A1) ) components are mixed and/or partially bonded.

In the present invention, the amount of the (meth)acrylate polymer (A1) and the (meth)acrylate monomer (α1) used is when the (meth)acrylic resin composition (A) is 100% by mass , preferably the (meth)acrylate polymer (A1) is 5 mass % to 25 mass %, the (meth)acrylate monomer (α1) is 74.8 mass % to 94.8 mass %, more preferably (meth) The acrylate polymer (A1) is not less than 10% by mass and not more than 20% by mass, and the (meth)acrylate monomer (α1) is not less than 79.5% by mass and not more than 89.5% by mass. When the content ratio of the (meth)acrylate monomer (α1) is within the above range, the heat conductive pressure sensitive adhesive composition (F) and the heat conductive pressure sensitive adhesive sheet-like molded article (G) can be easily prepared. forming.

In addition, in the present invention, the usage-amount of the polyfunctional monomer (D) is preferably not less than 0.2% by mass and not more than 13% by mass when the (meth)acrylic resin composition (A) is 100% by mass, and more preferably Preferably it is 0.2 mass % or more and 10 mass % or less, More preferably, it is 0.5 mass % or more and 5 mass % or less. When the usage-amount of a polyfunctional monomer (D) is in the said range, it becomes easy to provide a heat conductive pressure-sensitive adhesive composition (F) and a heat conductive pressure-sensitive-adhesive sheet-like molded article (G) as a pressure-sensitive adhesive. Appropriate cohesion of the adhesive. The components contained in the (meth)acrylic resin composition (A) will be described in more detail below.

((meth)acrylate polymer (A1))

The (meth)acrylate polymer (A1) usable in the present invention is not particularly limited, and preferably contains (meth)acrylate monomer units (a1) that form a homopolymer having a glass transition temperature of -20°C or lower. ), and a monomer unit (a2) having an organic acid group.

The (meth)acrylate monomer (a1m) providing the unit (a1) of the above-mentioned (meth)acrylate monomer is not particularly limited, for example, ethyl acrylate (glass transition temperature of homopolymer -24°C), n-propyl acrylate (glass transition temperature of homopolymer is -37°C), n-butyl acrylate (glass transition temperature of homopolymer is -54°C), sec-butyl acrylate (homopolymer The glass transition temperature of the polymer is -22°C), n-heptyl acrylate (the glass transition temperature of the homopolymer is -60°C), n-hexyl acrylate (the glass transition temperature of the homopolymer is -61°C), n-octyl acrylate (the glass transition temperature of the homopolymer is -65°C), 2-ethylhexyl acrylate (the glass transition temperature of the homopolymer is -50°C), 2-methoxyethyl acrylate ( The glass transition temperature of the homopolymer is -50°C), 3-methoxypropyl acrylate (the glass transition temperature of the homopolymer is -75°C), 3-methoxybutyl acrylate (the glass transition temperature of the homopolymer The glass transition temperature is -56°C), ethoxymethyl acrylate (the glass transition temperature of the homopolymer is -50°C), n-octyl methacrylate (the glass transition temperature of the homopolymer is -25°C ), n-decyl methacrylate (the glass transition temperature of the homopolymer is -49°C), etc. Among them, n-butyl acrylate, 2-ethylhexyl acrylate, and 2-methoxyethyl acrylate are preferred, n-butyl acrylate and 2-ethylhexyl acrylate are more preferred, and 2-ethylhexyl acrylate is further preferred.

These (meth)acrylate monomers (a1m) may be used alone or in combination of two or more.

The (meth)acrylate monomer (a1m) is such that the monomer unit (a1) derived therefrom is preferably 80% by mass or more and 99.9% by mass or less in the (meth)acrylate polymer (A1), more preferably The amount of 85 mass % or more and 99.5 mass % or less is used for polymerization. When the usage-amount of a (meth)acrylate monomer (a1m) exists in the said range, it becomes easy to maintain the viscosity of the polymerization system at the time of superposition|polymerization in an appropriate range.

Next, the monomeric unit (a2) which has an organic acid group is demonstrated. The monomer (a2m) providing the monomer unit (a2) having an organic acid group is not particularly limited, and representative monomers thereof include units having an organic acid group such as a carboxyl group, an acid anhydride group, and a sulfonic acid group. body. In addition, monomers containing sulfenic acid groups, sulfinic acid groups, phosphoric acid groups, and the like can also be used.

Specific examples of monomers having carboxyl groups include α,β-ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and α,β-ethylenically unsaturated monocarboxylic acids such as itaconic acid, maleic acid, and fumaric acid. ,β-Ethylenically unsaturated polycarboxylic acids, in addition to itaconate monomethyl ester, maleate monobutyl ester, fumaric acid monopropyl ester and other α,β-ethylenically unsaturated polycarboxylic acids Acid partial esters, etc. In addition, monomers having a group capable of deriving a carboxyl group by hydrolysis or the like, such as maleic anhydride and itaconic anhydride, can be used in the same manner.

Specific examples of monomers having sulfonic acid groups include allylsulfonic acid, methallylsulfonic acid, vinylsulfonic acid, styrenesulfonic acid, and acrylamide-2-methylpropanesulfonic acid. etc. α, β-unsaturated sulfonic acids, and their salts.

As the monomer (a2m), among the above-exemplified monomers having an organic acid group, a monomer having a carboxyl group is more preferable, and among them, a monomer having an acrylic acid or a methacrylic acid is particularly preferable. These monomers are industrially inexpensive and readily available, and have good copolymerizability with other monomer components, and are also preferable in terms of productivity. It should be noted that the monomer (a2m) may be used alone or in combination of two or more.

A monomer (a2m) having an organic acid group such that the monomer unit (a2) derived therefrom is preferably 0.1% by mass or more and 20% by mass or less, more preferably 0.5% by mass or less in the (meth)acrylate polymer (A1) Mass % to 15 mass % is used for polymerization. When the usage-amount of the monomer (a2m) which has an organic acid group exists in the said range, it becomes easy to maintain the viscosity of the polymerization system at the time of polymerization in an appropriate range.

It should be noted that it is easy to introduce the monomer unit (a2) having an organic acid group into the (meth)acrylate polymer (A1) by polymerizing the monomer (a2m) having an organic acid group as described above. , which is preferable, but it is also possible to introduce an organic acid group by a known polymer reaction after the (meth)acrylate polymer (A1) is produced.

Moreover, the (meth)acrylate polymer (A1) may contain the monomeric unit (a3) derived from the monomer (a3m) which has a functional group other than an organic acid group. As a functional group other than the said organic acid group, a hydroxyl group, an amino group, an amide group, an epoxy group, a mercapto group, etc. are mentioned.

Examples of the monomer having a hydroxyl group include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, etc., hydroxyalkyl (meth)acrylate, and the like.

Examples of the monomer having an amino group include N,N-dimethylaminomethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, aminostyrene, and the like.

Examples of the monomer having an amide group include acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, N,N-dimethylacrylamide, etc. α,β - Ethylenically unsaturated carboxamide monomers and the like.

Glycidyl (meth)acrylate, allyl glycidyl ether, etc. are mentioned as a monomer which has an epoxy group.

A monomer (a3m) having a functional group other than an organic acid group may be used alone or in combination of two or more.

These monomers (a3m) having functional groups other than organic acid groups are preferably used in an amount such that the monomer unit (a3) derived therefrom is 10% by mass or less in the (meth)acrylate polymer (A1). polymerization. By using 10% by mass or less of the monomer (a3m), it becomes easy to maintain the viscosity of the polymerization system at the time of polymerization in an appropriate range.

(Meth)acrylate polymer (A1) In addition to the above-mentioned (meth)acrylate monomer unit (a1) forming a homopolymer with a glass transition temperature of -20°C or less, and a monomer unit having an organic acid group In addition to (a2) and the monomer unit (a3) having a functional group other than an organic acid group, a monomer unit (a4) derived from a monomer (a4m) copolymerizable with the above monomer may be contained.

The monomer (a4m) is not particularly limited, and specific examples thereof include (meth)acrylate monomers other than the above-mentioned (meth)acrylate monomer (a1m), α,β-ethylenic Saturated polycarboxylic acid full ester, alkenyl aromatic monomer, conjugated diene monomer, non-conjugated diene monomer, cyanide vinyl monomer, carboxylic acid unsaturated alcohol ester, olefin monomer, etc. .

Specific examples of (meth)acrylate monomers other than the above-mentioned (meth)acrylate monomer (a1m) include methyl acrylate (the glass transition temperature of the homopolymer is 10°C), methacrylic acid Methyl ester (the glass transition temperature of the homopolymer is 105°C), ethyl methacrylate (the glass transition temperature of the homopolymer is 63°C), n-propyl methacrylate (the glass transition temperature of the homopolymer 25°C), n-butyl methacrylate (the glass transition temperature of the homopolymer is 20°C), etc.

Specific examples of α,β-ethylenically unsaturated polyhydric carboxylic acid full esters include dimethyl fumarate, diethyl fumarate, dimethyl maleate, diethyl maleate, Dimethyl itaconate, etc.

Specific examples of alkenyl aromatic monomers include styrene, α-methylstyrene, methyl α-methylstyrene, vinyltoluene, and divinylbenzene.

Specific examples of conjugated diene-based monomers include 1,3-butadiene, 2-methyl-1,3-butadiene (synonymous with isoprene), 1,3- Pentadiene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, cyclopentadiene, etc.

Specific examples of the non-conjugated diene-based monomer include 1,4-hexadiene, dicyclopentadiene, ethylidene norbornene, and the like.

Specific examples of vinyl cyanide monomers include acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, α-ethacrylonitrile, and the like.

Vinyl acetate etc. are mentioned as a specific example of a carboxylic acid unsaturated alcohol ester monomer.

Specific examples of the olefin-based monomer include ethylene, propylene, butene, pentene, and the like.

One type of monomer (a4m) may be used alone, or two or more types may be used in combination.

The monomer (a4m) is supplied in such an amount that the monomer unit (a4) derived therefrom is preferably 10% by mass or less, more preferably 5% by mass or less in the (meth)acrylate polymer (A1). polymerization.

The (meth)acrylate polymer (A1) is obtained by adding the above-mentioned (meth)acrylate monomer (a1m) which forms a homopolymer having a glass transition temperature below -20°C, and a monomer having an organic acid group (a2m), if necessary, a monomer (a3m) containing a functional group other than an organic acid group, and if necessary, a monomer (a4m) that can be copolymerized with these monomers, and can be particularly suitably obtained .

The polymerization method for obtaining the (meth)acrylate polymer (A1) is not particularly limited, and any one of solution polymerization, emulsion polymerization, suspension polymerization, bulk polymerization, etc. may be used, or methods other than these may be used. Among them, solution polymerization is preferred among these polymerization methods, and solution polymerization using carboxylic acid esters such as ethyl acetate and ethyl lactate or aromatic solvents such as benzene, toluene and xylene as the polymerization solvent is more preferred. Upon polymerization, the monomers may be added in batches to the polymerization reaction vessel, but all amounts are preferably added together. The method of initiating polymerization is not particularly limited, but it is preferable to use a thermal polymerization initiator as a polymerization initiator. The thermal polymerization initiator is not particularly limited, and for example, peroxide polymerization initiators and azo compound polymerization initiators can be used.

Examples of peroxide polymerization initiators include potassium persulfate, sodium persulfate, Persulfates such as ammonium persulfate, etc. These peroxides can be used in combination with a reducing agent as appropriate as a redox catalyst.

Examples of the azo compound polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, Bis(2-methylbutyronitrile), etc.

The usage-amount of a polymerization initiator is not specifically limited, It is preferable that it is the range of 0.01 mass part or more and 50 mass parts or less with respect to 100 mass parts of monomers.

Other polymerization conditions (polymerization temperature, pressure, stirring conditions, etc.) of these monomers are not particularly limited.

After the polymerization reaction is completed, the resulting polymer is separated from the polymerization medium as necessary. The separation method is not particularly limited. For example, in the case of solution polymerization, the (meth)acrylate polymer (A1) can be obtained by leaving the polymerization solution under reduced pressure and distilling off the polymerization solvent.

The weight average molecular weight (Mw) of the (meth)acrylate polymer (A1) is measured by gel permeation chromatography (GPC method), and in terms of standard polystyrene, it is preferably in the range of 100,000 to 1 million, and more preferably It is preferably in the range of 200,000 to 500,000. The weight average molecular weight of a (meth)acrylate polymer (A1) can be controlled by suitably adjusting the quantity of the polymerization initiator used for superposition|polymerization, and the quantity of a chain transfer agent.

((meth)acrylate monomer (α1))

The (meth)acrylate monomer (α1) is not particularly limited as long as it contains a (meth)acrylate monomer, but preferably contains a (meth)acrylate that forms a homopolymer having a glass transition temperature of -20°C or lower. Monomer (a5m).

Examples of (meth)acrylate monomers (a5m) that form homopolymers with a glass transition temperature of -20°C or lower include those used in the synthesis of (meth)acrylate polymers (A1). (meth)acrylate monomer (a1m) The same (meth)acrylate monomer. The (meth)acrylate monomer (a5m) may be used alone or in combination of two or more.

The ratio of the (meth)acrylate monomer (a5m) in the (meth)acrylate monomer (α1) is preferably 50% by mass or more and 100% by mass or less, more preferably 75% by mass or more and 100% by mass or less. By setting the ratio of the (meth)acrylate monomer (a5m) in the (meth)acrylate monomer (α1) within the above range, heat-conductive pressure-sensitive adhesive with excellent pressure-sensitive adhesiveness and flexibility can be easily obtained An agent composition (F) and a heat-conductive pressure-sensitive-adhesive sheet-like molded article (G).

In addition, the (meth)acrylate monomer (α1) can also be a (meth)acrylate monomer (a5m) that forms a homopolymer with a glass transition temperature below -20°C, and a compound having Mixture of organic acid-based monomers (a6m).

Examples of the monomer (a6m) include the same monomers having an organic acid group as those exemplified as the monomer (a2m) used in the synthesis of the (meth)acrylate polymer (A1). The monomer (a6m) can be used alone or in combination of two or more.

The ratio of the monomer (a6m) in the (meth)acrylate monomer (α1) is preferably 30% by mass or less, more preferably 10% by mass or less. When the ratio of the monomer (a6m) in the (meth)acrylate monomer (α1) is within the above-mentioned range, it is easy to obtain pressure-sensitive adhesiveness and a thermally conductive pressure-sensitive adhesive composition (F) excellent in flexibility And a heat-conductive pressure-sensitive-adhesive sheet-like molded article (G).

The (meth)acrylate monomer (α1) may be a mixture containing (meth)acrylate monomer (a5m) and monomer (a6m) having an organic acid group that can be copolymerized as needed In addition, it also contains monomers (a7m) that can be copolymerized with them.

Examples of the monomer (a7m) include the same monomers as the monomer (a3m) and the monomer (a4m) used in the synthesis of the (meth)acrylate polymer (A1). body. The monomer (a7m) may be used alone or in combination of two or more.

The ratio of the monomer (a7m) in the (meth)acrylate monomer (α1) is preferably 20% by mass or less, more preferably 15% by mass or less.

(Polyfunctional monomer (D))

As the polyfunctional monomer (D), a monomer copolymerizable with the monomer contained in the (meth)acrylate monomer (α1) is used. In addition, the polyfunctional monomer (D) has a plurality of polymerizable unsaturated bonds, and preferably has the unsaturated bonds at the terminal. By using such a polyfunctional monomer (D), intramolecular and/or intermolecular crosslinking can be introduced into the copolymer to improve the thermally conductive pressure-sensitive adhesive composition (F) and thermally conductive pressure-sensitive adhesive properties The cohesive force of the sheet-like molded product (G) as a pressure-sensitive adhesive.

Usually, during polymerization such as radical thermal polymerization, even if the polyfunctional monomer (D) is not used, a certain degree of crosslinking reaction proceeds. However, in order to more reliably form a desired amount of crosslinked structure, it is preferable to use a polyfunctional monomer (D).

As the polyfunctional monomer (D), for example, except 1,6-hexanediol di(meth)acrylate, 1,2-ethylene glycol di(meth)acrylate, 1, 12-Dodecanediol Di(meth)acrylate, Polyethylene Glycol Di(meth)acrylate, Polypropylene Glycol Di(meth)acrylate, Neopentyl Glycol Di(meth)acrylate, Pentaerythritol Di(meth)acrylate, Trimethylolpropane tri(meth)acrylate, Pentaerythritol tri(meth)acrylate, Di(trimethylol)propane tri(meth)acrylate, Pentaerythritol tetra(meth)acrylate base) acrylate, dipentaerythritol hexa(meth)acrylate and other polyfunctional (meth)acrylates, 2,4-bis(trichloromethyl)-6-p-methoxystyrene-5-triazine In addition to such substituted triazines, monoethylenically unsaturated aromatic ketones such as 4-acryloyloxybenzophenone and the like can also be used. Among these, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate are preferable. A polyfunctional monomer (D) may be used individually by 1 type, and may use 2 or more types together.

<polymerization initiator>

When obtaining the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive-adhesive sheet-like molded article (G), as described above, the (meth)acrylic resin composition (A) contained Component aggregation. In order to promote this polymerization reaction, it is preferable to use a polymerization initiator. As this polymerization initiator, a photopolymerization initiator, an azo type thermal polymerization initiator, an organic peroxide thermal polymerization initiator, etc. are mentioned. Among them, it is preferable to use an organic peroxide thermally polymerized Initiator.

Various well-known photoinitiators can be used as a photoinitiator. Among them, acylphosphine oxide-based compounds are preferable. Examples of acylphosphine oxide-based compounds preferred as photopolymerization initiators include bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenyl Phosphine oxide etc.

Examples of the azo-based thermal polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, Nitrogen bis(2-methylbutyronitrile), etc.

Examples of the organic peroxide thermal polymerization initiator include hydrogen peroxide such as tert-butyl hydroperoxide, benzoyl peroxide, cyclohexanone peroxide, 1,6-bis(tert-butylperoxycarbonyloxy ) hexane, peroxides such as 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexanone, etc. Among them, an initiator that does not release a volatile substance causing an odor during thermal decomposition is preferable. In addition, among organic peroxide thermal polymerization initiators, those having a one-minute half-life temperature of 100° C. or higher and 170° C. or lower are preferable.

The amount of the polymerization initiator used is preferably 0.01 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, and still more preferably 0.3 parts by mass to 100 parts by mass of the (meth)acrylic resin composition (A). More than 2 parts by mass and less than 2 parts by mass. When the amount of the polymerization initiator used is within the above range, the polymerization conversion rate of the (meth)acrylate monomer (α1) can be easily adjusted to an appropriate range, and it is easy to prevent monomer odor from remaining in the heat-conductive pressure-sensitive adhesive composition. (F) and heat-conductive pressure-sensitive-adhesive sheet-like molded article (G).

In addition, it is preferable that the polymerization conversion rate of (meth)acrylate monomer (α1) is 95 mass % or more. If the polymerization conversion rate of the (meth)acrylate monomer (α1) is 95% by mass or more, it is easy to prevent monomer odor from remaining in the heat-conductive pressure-sensitive adhesive composition (F) and the heat-conductive pressure-sensitive adhesive property Sheet molding (G). Moreover, by making the usage-amount of a polymerization initiator into the said range, it becomes easy to prevent that a polymerization reaction progresses excessively, and a thermally conductive pressure-sensitive-adhesive sheet-shaped molded object (G) does not become a smooth sheet shape, and material destruction occurs. .

＜Thermally conductive filler (B1)＞

Next, the thermally conductive filler (B1) will be described. The thermally conductive filler (B1) used in the present invention is a thermally conductive filler having a BET specific surface area of 1.0 m ² /g or more and not subjected to titanate treatment. The upper limit of the BET specific surface area of the thermally conductive filler (B1) is not particularly limited, and it is suppressed from being a precursor of the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive-adhesive sheet-like molded article (G). From the viewpoint of excessively high viscosity of the mixed composition, it is preferably 10 m ² /g or less.

In addition, "BET specific surface area" in this invention means the value measured by the following method. First, a mixed gas of nitrogen and helium is introduced into the BET specific surface area measuring device, and the sample unit containing the sample (object to be measured for BET specific surface area) is immersed in liquid nitrogen to adsorb nitrogen gas on the sample surface. After the adsorption equilibrium is reached, the sample unit is placed in a water bath and heated to room temperature to desorb the nitrogen attached to the sample. When nitrogen is adsorbed and desorbed, the mixing ratio of the gas before and after passing through the sample unit changes. Therefore, using a gas with a constant mixing ratio of nitrogen and helium as a comparison, the change is detected by a thermal conductivity detector (TCD), and the nitrogen gas is calculated. adsorption and desorption capacity. Before the measurement, a unit amount of nitrogen gas was introduced into the device for calibration, and the value of the surface area corresponding to the value detected by TCD was obtained in advance, thereby obtaining the surface area of the sample. In addition, the BET specific surface area can be obtained by dividing the surface area by the mass of the sample.

It is considered that by adding a filler having a large BET specific surface area, it is possible to suppress the transfer of liquid components such as phosphate ester (C) described later from the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive-adhesive sheet-like molded article ( G) Outflow.

However, if a large amount of filler with a large BET specific surface area is added, the performance of the mixed composition as a precursor of the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive-adhesive sheet-like molded article (G) When the viscosity is too high, it becomes difficult to mold the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive-adhesive sheet-like molded article (G). Therefore, in the present invention, a thermally conductive filler (B1) having a large BET specific surface area and a titanate-treated thermally conductive filler (B2) described below are used in combination. It is known that the addition of the titanate-treated thermally conductive filler (B2) suppresses an increase in the viscosity of the resin composition compared to the case of adding a titanate-free filler. The inventors of the present invention further found that the titanate-treated thermally conductive filler (B2) has an effect of suppressing exudation of liquid components. According to the present invention, by using an appropriate amount of each of the thermally conductive filler (B1) and the thermally conductive filler (B2) in combination, it is possible to suppress an increase in the viscosity of the mixed composition and to suppress bleeding of the liquid component.

The BET specific surface area of the thermally conductive filler (B1) is 1.0 m ² /g or more, and it is a filler that has not been treated with titanate. By adding it, it is possible to combine the thermally conductive pressure-sensitive adhesive compared with the case where it is not added. The thermal conductivity of the material (F) and the thermally conductive pressure-sensitive-adhesive sheet-like molded product (G) is further improved, and there is no particular limitation as long as it is a filler having a thermal conductivity of 0.5 W/m·K or more.

Specific examples of the thermally conductive filler (B1) include metal hydroxides such as aluminum hydroxide, magnesium hydroxide, and calcium hydroxide; metal oxides such as aluminum oxide, magnesium oxide, and zinc oxide; and calcium carbonate. , aluminum carbonate and other metal carbonates; boron nitride, aluminum nitride and other metal nitrides; zinc borate hydrate; kaolin; calcium aluminate hydrate; silicon dioxide, etc. Among them, metal hydroxides, metal oxides and metal carbonates are preferred, metal hydroxides and metal oxides are more preferred, aluminum hydroxide and aluminum oxide are further preferred, and aluminum oxide is particularly preferred. One type of heat conductive filler (B1) may be used alone, or two or more types may be used in combination.

The average particle size of the thermally conductive filler (B1) used in the present invention is preferably 0.5 μm to 50 μm, more preferably 1 μm to 30 μm.

In addition, in this invention, an "average particle diameter" means the value measured by the method demonstrated below. That is, measurement was performed using a laser-type particle size measuring machine (manufactured by Seishin Co., Ltd.) using a micro-separation control method (a method in which the particles to be measured pass only within the measurement area to improve measurement reliability). With this measurement method, 0.01 g to 0.02 g of the particles to be measured are poured into the cell, and the particles to be measured that flow into the measurement area are irradiated with a semiconductor laser beam with a wavelength of 670 nm, and the scattering and diffraction of the laser light at this time are measured using a measuring machine. Langhefei's diffraction principle calculates the average particle size and particle size distribution.

The amount of the thermally conductive filler (B1) used in the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive-adhesive sheet-like molded article (G) of the present invention relative to the (meth)acrylic resin combination 100 parts by mass of the substance (A), 120 to 450 parts by mass, preferably 150 to 450 parts by mass, more preferably 150 to 400 parts by mass. If the content of the thermally conductive filler (B1) exceeds the above range, there is a concern that the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive-adhesive sheet-like molded article (G) may The viscosity of the mixed composition of the precursor increases excessively, making it difficult to mold the heat-conductive pressure-sensitive adhesive composition (F) and the heat-conductive pressure-sensitive-adhesive sheet-like molded article (G), or even if it can be molded, the thermal conductivity The hardness of the pressure-sensitive adhesive composition (F) and the heat-conductive pressure-sensitive-adhesive sheet-like molded article (G) also increases, and shape followability (adhesion to an adherend) also decreases. On the other hand, if the content of the thermally conductive filler (B1) is less than the above range, there is a risk of suppressing the transfer of liquid components from the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive adhesive by using the thermally conductive filler (B1). There is a concern that the bleeding effect in the contact sheet-like molded article (G) may become insufficient.

＜Thermally conductive filler (B2)＞

Next, the thermally conductive filler (B2) will be described. The thermally conductive filler (B2) used in the present invention is a titanate-treated thermally conductive filler. The method of titanate treatment of the thermally conductive filler (B2) is not particularly limited, and it can be performed using a known titanate-based coupling agent.

As a titanate-based coupling agent, for example, isopropyl triisostearyl titanate, isopropyl tris(dodecylbenzenesulfonyl) titanate, isopropyl tris(dioctyl pyrene) Phosphoryloxy) titanate, Tetraisopropylbis(dioctylphosphiteoxy)titanate, Tetraoctylbis(bis(tridecyl)phosphiteoxy)titanate, Bis(dioctylpyrophosphate)oxyacetate titanate, bis(dioctylpyrophosphate)ethylene titanate, isopropyltricaprylyl titanate, isopropyl Di(methacryl) isostearyl titanate, isopropyl isostearyl diacryloyl titanate, isopropyl tri(dioctyl phosphate acyloxy) titanate, isopropyl tri Cumylphenyl titanate, isopropyl tris(N-amidoethyl・aminoethyl) titanate, dicumylphenyloxyacetate titanate, and diisostearyl ethylene titanate etc.

The thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive adhesive sheet can be molded by adding the thermally conductive filler (B2) as long as it is preliminarily treated with titanate The thermal conductivity of the body (G) is improved, and it is not particularly limited as long as the filler has a thermal conductivity of 0.5 W/m・K or more.

Specific examples of the thermally conductive filler (B2) include those obtained by subjecting the following thermally conductive fillers to titanate treatment. Examples include metal hydroxides such as aluminum hydroxide, gallium hydroxide, indium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, and barium hydroxide; metals such as aluminum oxide, magnesium oxide, and zinc oxide. Oxides; metal carbonates such as calcium carbonate and aluminum carbonate; metal nitrides such as boron nitride and aluminum nitride; zinc borate hydrate; kaolin; calcium aluminate hydrate; dawsonite; silicon dioxide, etc. . Among these, metal hydroxides, metal oxides, and metal carbonates are preferable, metal hydroxides are more preferable, and aluminum hydroxide is particularly preferable. The thermally conductive filler (B2) may be used alone or in combination of two or more.

The average particle diameter of the thermally conductive filler (B2) used in the present invention is preferably 1 μm to 80 μm, and more preferably 5 μm to 50 μm.

The amount of the thermally conductive filler (B2) used in the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive-adhesive sheet-like molded article (G) of the present invention relative to the (meth)acrylic resin combination 100 parts by mass of the substance (A), 120 to 500 parts by mass, preferably 150 to 450 parts by mass, more preferably 150 to 400 parts by mass. When the content of the thermally conductive filler (B2) exceeds the above range, there is a concern that it may be used as a precursor of the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive-adhesive sheet-like molded article (G). The viscosity of the mixed composition of the body increases excessively, making it difficult to mold the heat conductive pressure sensitive adhesive composition (F) and the heat conductive pressure sensitive adhesive sheet-like molded body (G), or even if it can be molded, the heat conductive pressure sensitive adhesive The hardness of the sensitive adhesive composition (F) and the heat conductive pressure-sensitive-adhesive sheet-like molded article (G) also increases, and shape followability (adhesion to an adherend) also decreases. On the other hand, if the content of the thermally conductive filler (B2) is less than the above range, there is a risk of suppressing the transfer of liquid components from the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive adhesive by using the thermally conductive filler (B2). There is a concern that the bleeding effect in the contact sheet-like molded article (G) may become insufficient.

＜Thermally conductive filler (B3)＞

Next, the thermally conductive filler (B3) will be described. The thermally conductive filler (B3) used in the present invention is a thermally conductive filler other than the thermally conductive filler (B1) and the thermally conductive filler (B2). As the thermally conductive filler (B3), a filler that has not been previously treated with titanate and has a BET specific surface area outside the range of the aforementioned thermally conductive filler (B1) can be used.

Specific examples of the thermally conductive filler (B3) include metal hydroxides such as aluminum hydroxide, gallium hydroxide, indium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, and barium hydroxide; aluminum oxide ( Metal oxides such as aluminum), magnesium oxide, zinc oxide, etc.; metal carbonates such as calcium carbonate, aluminum carbonate, etc.; metal nitrides such as boron nitride, aluminum nitride, etc.; zinc borate hydrate; kaolin; calcium aluminate hydrate Dawsonite; Silica; Carbon-containing conductive fillers such as expanded graphite, artificial graphite, carbon black, carbon fiber, etc. Among them, metal hydroxides, metal oxides, and carbon-containing conductive fillers are preferred, aluminum hydroxide, aluminum oxide, and expanded graphite are more preferred, aluminum hydroxide and aluminum oxide are further preferred, and aluminum hydroxide is particularly preferred. The thermally conductive filler (B3) may be used alone or in combination of two or more.

The amount of the thermally conductive filler (B3) used in the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive-adhesive sheet-like molded article (G) of the present invention relative to the (meth)acrylic resin combination 100 parts by mass of the substance (A), 200 to 600 parts by mass, preferably 200 to 550 parts by mass, more preferably 250 to 550 parts by mass. When the content of the thermally conductive filler (B3) exceeds the above-mentioned range, there is a concern that it may be used as a precursor of the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive-adhesive sheet-like molded article (G). The viscosity of the mixed composition of the body increases excessively, making it difficult to mold the heat conductive pressure sensitive adhesive composition (F) and the heat conductive pressure sensitive adhesive sheet-like molded product (G), or even if it can be molded, the heat conductive pressure sensitive adhesive The hardness of the sensitive adhesive composition (F) and the heat conductive pressure-sensitive-adhesive sheet-like molded article (G) also increases, and shape followability (adhesion to an adherend) also decreases. On the other hand, if the content of the thermally conductive filler (B3) is less than the above range, there is a risk of suppressing the transfer of liquid components from the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive adhesive by using the thermally conductive filler (B3). There is a concern that the bleeding effect in the contact sheet-like molded article (G) may become insufficient. In addition, when the thermally conductive filler (B3) contains the above-mentioned carbon-containing conductive filler, the amount of the carbon-containing conductive filler is preferably not less than 1 part by mass and not more than 30 parts by mass with respect to 100 parts by mass of the (meth)acrylic resin composition (A). .

＜Phosphate (C)＞

Next, the phosphoric acid ester (C) will be described. By using a phosphate ester (C), it becomes easy to provide the heat conductive pressure-sensitive-adhesive composition (F) and the heat conductive pressure-sensitive-adhesive sheet-shaped molded object (G) with excellent flame retardancy.

The phosphoric acid ester (C) used in the present invention preferably has a viscosity at 25° C. of 3000 mPa·s or more. By making the viscosity of a phosphate ester (C) into the said range, it becomes easy to prevent the moldability deterioration of a heat conductive pressure-sensitive-adhesive composition (F) or a heat conductive pressure-sensitive-adhesive sheet-shaped molded object (G). In addition, the "viscosity" of a phosphate ester (C) in this invention means the viscosity measured by the method demonstrated below.

(Measurement method of viscosity of phosphate ester)

Viscosity measurement of phosphoric acid ester was performed by the procedure shown below using the B-type viscometer (made by Tokyo Keiki Co., Ltd.).

(1) Measure 300ml of phosphate ester at room temperature and put it into a 500ml container.

(2) Select any one of rotor No. 1, 2, 3, 4, 5, 6, and 7 for stirring, and install it in the viscometer.

(3) Place the container containing the phosphoric acid ester on the viscometer, and sink the rotor into the phosphoric acid ester in the container. At this time, sinking was carried out so that the dent as the rotor mark just entered the liquid interface of the phosphoric acid ester.

(4) Select the speed from 20, 10, 4, 2.

(5) Turn on the stirring switch and read the value after 1 minute.

(6) The value obtained by multiplying the read value by the coefficient A is the viscosity [mPa・s].

It should be noted that the coefficient A is determined by the selected rotor No. and rotation speed as shown in Table 1 below.

[Table 1]

.

In addition, the phosphoric acid ester (C) used in the present invention is preferably always liquid in a temperature range of 15° C. to 100° C. under atmospheric pressure. Phosphate ester (C) is good in workability as long as it is a liquid when mixed, and it can be molded into heat-conductive pressure-sensitive adhesive composition (F) or heat-conductive pressure-sensitive-adhesive sheet-shaped molded article (G). easy. When molding the heat-conductive pressure-sensitive adhesive composition (F) or the heat-conductive pressure-sensitive-adhesive sheet-like molded article (G) containing the phosphate (C), it is preferably under an environment of 15°C or higher and 100°C or lower , each material constituting the heat-conductive pressure-sensitive adhesive composition (F) or the heat-conductive pressure-sensitive-adhesive sheet-like molded article (G) is mixed. When the temperature at the time of mixing is within the above-mentioned range, making it equal to or higher than the glass transition temperature of the (meth)acrylic resin composition (A), it is easy to prevent the monomer contained in the (meth)acrylic resin composition (A) from Etc. volatilization or polymerization reaction starts, so the environmental performance and operability can be improved.

In the present invention, as the phosphoric acid ester (C), either a condensed phosphoric acid ester or a non-condensed phosphoric acid ester may be used. The term "condensed phosphoric acid ester" as used herein means that there are a plurality of phosphoric acid ester moieties in one molecule, and the "non-condensed phosphoric acid ester" means that only one phosphoric acid ester moiety exists in one molecule. Specific examples of phosphoric acid esters satisfying the conditions described above are listed below.

Specific examples of condensed phosphoric acid esters include: 1,3-phenylene bis(diphenyl phosphate), bisphenol A bis(diphenyl phosphate), resorcinol bis(diphenyl phosphate) ester) and other aromatic condensed phosphoric esters; halogen-containing condensed phosphoric esters such as polyoxyalkylene bis-dichloroalkyl phosphates; non-aromatic non-halogen condensed phosphoric esters; etc. Among these, aromatic condensed phosphoric acid esters are preferable, and 1,3-phenylene bis(diphenyl phosphate ), bisphenol A bis(diphenyl phosphate).

Specific examples of non-condensed phosphoric acid esters include triphenyl phosphate, tricresyl phosphate, tris(xylyl) phosphate, cresyl diphenyl phosphate, cresyl-2,6-xylyl phosphate, phosphoric acid Aromatic phosphoric acid esters such as 2-ethylhexyl diphenyl ester; Halogen-containing systems such as tris(β-chloropropyl) phosphate, tris(dichloropropyl) phosphate, tris(tribromoneopentyl) phosphate, etc. Phosphates, etc. Among them, aromatic phosphoric acid esters are preferable because no harmful substances (halogen, etc.) etc. are generated.

Phosphate esters (C) may be used alone or in combination of two or more.

The amount of the phosphoric acid ester (C) used in the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive-adhesive sheet-like molded article (G) of the present invention is expressed in terms of the (meth)acrylic resin composition ( A) is 100 parts by mass, 40 to 120 parts by mass, more preferably 50 to 100 parts by mass, still more preferably 60 to 100 parts by mass. By making content of a phosphate ester (C) into the said range, it becomes easy to provide the flame retardancy excellent in a heat conductive pressure-sensitive-adhesive composition (F) or a heat conductive pressure-sensitive-adhesive sheet-shaped molded object (G).

<Other additives>

In the heat-conductive pressure-sensitive adhesive composition (F) and the heat-conductive pressure-sensitive-adhesive sheet-shaped molded article (G) of the present invention, in addition to the above-mentioned substances, the above-mentioned Various known additives are added within the range of the effect. Examples of known additives include foaming agents (including foaming aids); glass fibers; external crosslinking agents; pigments; other fillers such as clay; nanoparticles such as fullerenes and carbon nanotubes; , Hydroquinone-based, hindered amine-based and other antioxidants; acrylic polymer particles, particulate silica and other thickeners, etc.

As described above, according to the present invention, flame retardancy is obtained by adding phosphate ester (C), and a thermally conductive filler (B1) with a large BET specific surface area and a thermally conductive filler treated with titanate are added in an appropriate amount. (B2), the heat conductive pressure-sensitive-adhesive composition (F) and the heat conductive pressure-sensitive-adhesive sheet-shaped molded object (G) which suppressed the bleeding of a liquid component can be obtained. Hereinafter, the manufacturing method of such a heat conductive pressure-sensitive-adhesive composition (F) and a heat conductive pressure-sensitive-adhesive sheet-shaped molded object (G) is demonstrated.

2. Manufacturing method

The heat-conductive pressure-sensitive adhesive composition (F) of the present invention can be prepared by mixing the above-mentioned substances to prepare a mixed composition, and at least carry out a (meth)acrylate monomer (α1) and a multifunctional monomer (D) polymerization reaction, and (meth)acrylate polymer (A1) and/or the polymer containing the structural unit derived from (meth)acrylate monomer (α1) crosslinking reaction.

That is, the production method of the heat conductive pressure-sensitive adhesive composition (F) of the present invention includes the step of preparing a mixed composition containing (meth)acrylate polymer (A1), (Meth)acrylic resin composition (A) of (meth)acrylate monomer (α1) and polyfunctional monomer (D), thermally conductive filler (B1), thermally conductive filler (B2), and thermal conductivity a filler (B3); and performing at least a polymerization reaction of a (meth)acrylate monomer (α1) and a polyfunctional monomer (D), and a (meth)acrylate polymer (A1) in the mixed composition And/or a step of crosslinking a polymer containing a structural unit derived from a (meth)acrylate monomer (α1). Note that other usable substances, preferred content ratios of the respective substances, and the like are as described above, and detailed description thereof will be omitted here.

The heat-conductive pressure-sensitive-adhesive sheet-like molded article (G) of the present invention can be obtained by mixing the above-described materials to prepare a mixed composition, molding the mixed composition into a sheet or after mixing the While the composition is shaped into a sheet, at least the polymerization reaction of the (meth)acrylate monomer (α1) and the polyfunctional monomer (D), and the (meth)acrylate polymer (A1) and/or A crosslinking reaction of a polymer comprising structural units derived from (meth)acrylate monomers (α1), thereby obtaining.

That is, the manufacturing method of the heat conductive pressure-sensitive-adhesive sheet-like molded article (G) of this invention includes the process of preparing the mixed composition containing (meth)acrylate polymer (A1 ), a (meth)acrylic resin composition (A), a (meth)acrylate monomer (α1) and a polyfunctional monomer (D), a thermally conductive filler (B1), a thermally conductive filler (B2), and a thermally conductive filler (B3); and performing at least (meth)acrylate monomer (α1) and polyfunctionality after or while molding the mixed composition into a sheet Polymerization reaction of monomer (D), and crosslinking reaction of (meth)acrylate polymer (A1) and/or a polymer containing a structural unit derived from (meth)acrylate monomer (α1) . In addition, other usable substances, preferable content ratios of each substance, etc. are as above-mentioned, and detailed description is abbreviate|omitted here.

In the method for producing the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive-adhesive sheet-like molded article (G) of the present invention, it is preferable to heat when performing the above-mentioned polymerization and crosslinking reactions. For this heating, for example, hot air, an electric heater, infrared rays, or the like can be used. The heating temperature at this time is preferably a temperature at which the polymerization initiator is efficiently decomposed and the polymerization of the (meth)acrylate monomer (α1) and the polyfunctional monomer (D) proceeds. The temperature range varies depending on the type of polymerization initiator used, but is preferably 100°C to 200°C, more preferably 130°C to 180°C.

Moreover, in the manufacturing method of the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) of this invention, the method of shape|molding the said mixed composition into a sheet shape is not specifically limited. As a suitable method, for example, the following method can be mentioned: the method of applying the above-mentioned mixed composition on a craft paper such as a polyester film that has undergone mold release treatment to form a sheet; sandwiching the above-mentioned mixed composition between two sheets A method of forming a sheet by pressing between release-treated craft papers and between rolls; and extruding the above mixed composition using an extruder while controlling the thickness through a die, by This method of forming a sheet, etc.

The thickness of the heat conductive pressure-sensitive-adhesive sheet-like molded article (G) can be 0.05 mm or more and 5 mm or less. By reducing the thickness of the heat conductive pressure-sensitive-adhesive sheet-like molded body (G), the thermal resistance in the thickness direction of the heat-conductive pressure-sensitive-adhesive sheet-like molded body (G) can be reduced. From this viewpoint, the upper limit of the thickness of the heat conductive pressure-sensitive-adhesive sheet-like molded article (G) is preferably 2 mm. On the other hand, the lower limit of the thickness of the heat conductive pressure-sensitive-adhesive sheet-like molded article (G) is preferably 0.1 mm. By making the heat-conductive pressure-sensitive-adhesive sheet-like molded article (G) have a certain thickness, it is easy to prevent the thermally-conductive pressure-sensitive-adhesive sheet-like molded article (G) from being attached to a heating element or a radiator. As a result of entrainment of air, it is easy to prevent an increase in thermal resistance, and it is easy to improve the operability in the process of attaching to an adherend.

In addition, the heat-conductive pressure-sensitive-adhesive sheet-like molded article (G) may be molded on one side or both sides of the base material. The material constituting the substrate is not particularly limited. Specific examples of the base material include foils of metals and alloys with excellent thermal conductivity such as aluminum, copper, stainless steel, and beryllium copper; materials; thermally conductive plastic films containing thermally conductive additives; various non-woven fabrics; glass fiber cloth; honeycomb structures, etc. As the plastic film, polyimide, polyethylene terephthalate, polyethylene naphthalate, polytetrafluoroethylene, polyetherketone, polyethersulfone, polymethylpentene, polyetheramide, Films of heat-resistant polymers such as imide, polysulfone, polyphenylene sulfide, polyamideimide, polyesterimide, and aromatic polyamide.

3. Example of use

The heat conductive pressure-sensitive adhesive composition (F) and heat conductive pressure-sensitive-adhesive sheet-like molded article (G) of this invention can be used as some electronic components with which an electronic device is equipped. In this case, it can be directly molded on a base material such as a radiator and provided as a part of an electronic component. Specific examples of such electronic equipment and electronic components include components around heat generating parts in equipment having electroluminescence (EL) and light emitting diode (LED) light sources, components around power supply equipment such as automobiles, fuel cells, solar Batteries, batteries, mobile phones, personal digital assistants (PDAs), notebook computers, liquid crystals, surface conduction electron emission displays (SEDs), plasma display panels (PDPs), and integrated circuits (ICs) and other equipment and parts that have heat generating parts.

In addition, as an example of the method of using the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive-adhesive sheet-like molded article (G) of the present invention in electronic equipment, an LED light source is used as an example. , the following usage methods can be listed. That is, directly attached to the LED light source; sandwiched between the LED light source and the heat dissipation material (radiator, fan, Peltier element, heat pipe, graphite sheet, etc.); attached to the heat dissipation material (heat dissipation material) connected to the LED light source device, fan, Peltier element, heat pipe, graphite sheet, etc.); used as a housing surrounding the LED light source; attached to the housing surrounding the LED light source; buried in the gap between the LED light source and the housing, etc. . Examples of applications of LED light sources include backlights for display devices with transmissive liquid crystal panels (TVs, mobile phones, PCs, notebook PCs, PDAs, etc.); lamps for vehicles; industrial lighting; commercial lighting; general residential use lighting etc.

In addition, specific examples other than LED light sources include the following examples. That is, there are PDP panels; IC heating parts; cold cathode tubes (CCFL); organic EL light sources; inorganic EL light sources; high-brightness light-emitting LED light sources; high-brightness light-emitting organic EL light sources; components etc.

Furthermore, as a usage method of the heat conductive pressure-sensitive adhesive composition (F) and heat conductive pressure-sensitive-adhesive sheet-shaped molded object (G) of this invention, sticking to the housing of an apparatus etc. are mentioned. For example, when used in a device such as an automobile, it can be attached to the inside of the housing of the automobile; attached to the outside of the housing of the automobile; connected to the housing of the automobile. The internal heating part (car navigation/fuel cell/heat exchanger) and the housing; attached to the heat dissipation part (car navigation/fuel cell/heat exchanger) attached to the inside of the housing of the car Wait on the board.

In addition, the heat conductive pressure-sensitive-adhesive composition (F) and heat conductive pressure-sensitive-adhesive sheet-like molded object (G) of this invention can also be used by the same method other than an automobile. Examples of objects include personal computers; houses; televisions; mobile phones; vending machines; refrigerators; solar cells; surface conduction electron emission displays (SED); organic EL displays; inorganic EL displays; organic EL lighting; inorganic EL Lighting; organic EL displays; personal notebook computers; PDAs; fuel cells; semiconductor devices; rice cookers; washing machines; washing and drying machines; optical semiconductor devices combining optical semiconductor elements and phosphors; various power supplies; game machines; capacitors wait.

Furthermore, the heat-conductive pressure-sensitive-adhesive composition (F) and heat-conductive pressure-sensitive-adhesive sheet-like molded article (G) of this invention are not limited to the said usage method, You may use by another method according to a use. For example, it is used for the uniformity of heat in carpets or heat pads; it is used as a sealant for LED light sources/heat sources; it is used as a sealant for solar cell units; it is used as a back sheet for solar cells; Used between the back plate and the top cover; used inside the heat insulation layer inside the vending machine; used together with desiccant and moisture absorbent inside the organic EL lighting cabinet; inside the organic EL lighting cabinet The heat conduction layer and its upper part are used together with desiccant and moisture absorber; the heat conduction layer, heat dissipation layer and above of the organic EL lighting enclosure are used together with desiccant and moisture absorber; inside the organic EL lighting enclosure The heat-conducting layer of the epoxy system and the heat-dissipating layer and above are used together with desiccants and hygroscopic agents; for cooling components used to cool people and animals, clothes, towels, sheets, etc., on the opposite side of the body Used on the surface; used in the pressurizing member of the anchoring device mounted in the image forming device such as electrophotographic copier and electrophotographic printer; used as the anchoring device mounted in the image forming device such as electrophotographic copier and electrophotographic printer The pressurization member itself is used; it is used as a heat transfer part for controlling the heat flow of the object to be processed in the film forming device; it is used between the outer layer and the interior of the radioactive material storage container; Used in the box of the panel; used between the reflective sheet of the CCFL backlight and the aluminum chassis, etc.

Production method of the thermally conductive pressure-sensitive adhesive composition (F), thermally conductive pressure-sensitive-adhesive sheet-like molded article (G), and thermally conductive pressure-sensitive adhesive composition (F) of the present invention described above , and the method for producing a heat-conductive pressure-sensitive-adhesive sheet-like molded article (G), it is preferable that the heat-conductive filler (B1) has a BET specific surface area of 1.0 m ² /g or more and is not treated with titanate. At least one of metal hydroxide and metal oxide, the thermally conductive filler (B2) is a titanate-treated metal hydroxide, and the thermally conductive filler (B3) is a thermally conductive filler (B1) and thermally conductive In addition to the conductive filler (B2), at least one selected from metal hydroxides, metal oxides, and carbon-containing conductive fillers, more preferably the thermally conductive filler (B1) has a BET specific surface area of 1.0 m ² /g or more At least one selected from aluminum hydroxide and aluminum oxide that has not been treated with titanate, the thermally conductive filler (B2) is aluminum hydroxide that has been treated with titanate, and the thermally conductive filler (B3) is At least one selected from the group consisting of aluminum hydroxide, aluminum oxide, and expanded graphite other than the thermally conductive filler (B1) and the thermally conductive filler (B2). In addition, the (meth)acrylic resin composition (A) preferably contains (meth)acrylate polymer (A1) 5% by mass to 25% by mass and (meth)acrylate monomer (α1) 74.8% by mass or more 94.8% by mass or less, and 0.2% by mass or more and 13% by mass or less of the polyfunctional monomer (D) having a plurality of polymerizable unsaturated bonds.

Example

Hereafter, although an Example is used and this invention is demonstrated in detail, this invention is not limited to an Example. It should be noted that "parts" or "%" used here are mass standards unless otherwise specified.

<Viscosity of mixed composition>

After preparing a mixed composition as described below, the viscosity of the mixed composition was measured using a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd.). The method of measuring the viscosity is the same as the method of measuring the viscosity of the phosphoric acid ester (C) described above. The results are shown in Tables 2 and 3. When the viscosity of a mixed composition is too high, it will become difficult to manufacture a heat conductive pressure-sensitive-adhesive sheet-shaped molded object.

＜Appearance shrinkage cavity＞

After producing a heat conductive pressure-sensitive-adhesive sheet-like molded body as described later, the external appearance of this heat-conductive pressure-sensitive-adhesive sheet-like molded body was visually observed. The results are shown in Tables 2 and 3. In Table 2, the case where shrinkage cavity was not confirmed was made into "(circle), and the case where shrinkage cavity was confirmed was made into "x".

＜Exudation amount＞

After producing a thermally conductive pressure-sensitive adhesive sheet-like molded body having a thickness of 1 mm as described later, the heat-conductive pressure-sensitively adhesive sheet-shaped molded body was cut into a size of 30 mm x 30 mm, sandwiched between oil-proof papers, Compression was performed until the thickness of the heat conductive pressure-sensitive-adhesive sheet-like molded product became 0.5 mm, and it was left still for 10 seconds. Then, change the position of the oil-blotting paper, and repeat the above-mentioned compression and standing (5 times in total). Then, the weight of the oil-blowing paper was measured, and the difference from the weight of the oil-blowing paper before the heat conductive pressure-sensitive-adhesive sheet-like molded body was sandwiched was made into the bleeding amount. The results are shown in Tables 2 and 3. It can be said that the less the amount of exudation is, the more the outflow of liquid components can be suppressed. It should be noted that evaluation of the amount of exudation was not performed for molded articles in which shrinkage cavities were confirmed in the evaluation of the above-mentioned appearance shrinkage cavities.

＜Flame Retardancy＞

After producing the heat conductive pressure-sensitive-adhesive sheet-shaped molded body of thickness 1mm as demonstrated below, it prepared five test pieces which cut out the rectangular test piece of width 10mm x length 150mm. Adjust the flow of air and gas of the Bunsen burner to produce a blue flame with a height of about 20mm, and place the flame of the burner at the lower end of the vertically supported test piece (in a way to cross the flame by about 10mm) and keep it for 10 seconds , Separate the test piece from the burner flame. Then, when the flame of the test piece is extinguished, the test piece is immediately brought into contact with the burner flame, and after holding for 10 seconds, the test piece is separated from the burner flame. After the first and second contact with the flame, the duration of flame and non-flame burning, and the presence or absence of burning drips were evaluated, and the judgment of UL-94 (flammability standard) was performed. That is, the sum of the flaming burning duration after the first and second contact flames, the flaming burning duration and the non-flaming burning duration after the 2nd contact flame finishing, and the total of the 5 test pieces Judgment was made by summing the burning time with and without flame, and the presence or absence of burning drippings. The 1st and 2nd times all ended the burning with flame within 10 seconds, the total of the duration of burning with flame and the burning time without flame for the 2nd time was within 30 seconds, and then the flame and non-flame of the 5 test pieces The case where the total flame burning time was within 50 seconds and there was no burning fallout was set to V-0. The results are shown in Table 2. From this evaluation, if the condition of V-0 is satisfied, it can be said that the flame retardancy is excellent. In addition, since the comparative example was inferior in the said other evaluation, it did not evaluate flame retardancy.

＜Preparation of thermally conductive pressure-sensitive adhesive sheet-like molded product＞

(Example 1)

100 parts of a monomer mixture consisting of 94% of 2-ethylhexyl acrylate and 6% of acrylic acid, 0.03 parts of 2,2'-azobisisobutyronitrile and 700 parts of ethyl acetate were placed in the reactor and uniformly After dissolution and nitrogen substitution, polymerization reaction was performed at 80° C. for 6 hours. The polymerization conversion rate was 97%. The obtained polymer was dried under reduced pressure, ethyl acetate was evaporated, and a viscous solid (meth)acrylate polymer (A1-1) was obtained. The (meth)acrylate polymer (A1-1) had a weight average molecular weight (Mw) of 270,000, and a weight average molecular weight (Mw)/number average molecular weight (Mn) of 3.1. The weight average molecular weight (Mw) and the number average molecular weight (Mn) were calculated|required by standard polystyrene conversion by gel permeation chromatography using tetrahydrofuran as an eluent.

Next, a polyfunctional monomer (Light Acrylet PE-3A, Kyoeisha Chemical Co., Ltd. ) 0.8 parts, 0.2 parts of a polyfunctional monomer containing pentaerythritol tetraacrylate and pentaerythritol diacrylate (Light Acrylite PE-4A, manufactured by Kyoeisha Chemical Co., Ltd.) mainly composed of pentaerythritol tetraacrylate, 0.2 parts of acrylic acid 2 -84 parts of ethylhexyl ester (2EHA) and 1.0 parts of organic peroxide thermal polymerization initiator (1,6-bis(tert-butylperoxycarbonyloxy)hexane (1 minute half-life temperature is 150°C)), These were mixed with 15 parts of the above-mentioned (meth)acrylate polymer (A1-1). For the mixing, a constant temperature bath (Biskomeito 150III, manufactured by Toki Sangyo Co., Ltd.) and a Hobbit mixer (ACM-5LVT type, manufactured by Kodaira Seisakusho Co., Ltd., capacity: 5 L) were used. The temperature regulation of the Harbiter vessel was set to 40° C., the rotational speed scale was set to 3, and the mixture was stirred for 10 minutes. This step is referred to as a first mixing step.

Next, 80 parts of phosphoric acid ester (Leofos 65, manufactured by Ajinomoto Fine Technology Co., Ltd., compound name: triaryl isopropyl phosphate) and fine alumina (manufactured by Showa Denko Co., Ltd., Brand name "AL-47-H", average particle size: 2 μm, BET specific surface area: 1.8 m ² /g) 300 parts, titanate-treated aluminum hydroxide (manufactured by Nippon Light Metal Co., Ltd., trade name "B303T ", average particle size: 15 μm) 300 parts, aluminum hydroxide not subjected to titanate treatment (manufactured by Nippon Light Metal Co., Ltd., trade name "BF083", average particle size: 8 μm, BET specific surface area: 0.8 m ² /g) 150 parts and 250 parts of alumina (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name "DAM-70", average particle size: 70 μm, BET specific surface area: 0.1 m ² /g) without titanate treatment were added to the above In the Harbiter vessel, the temperature of the Harbiter vessel was adjusted to 40° C., the rotational speed scale was set to 5, and the mixture was stirred for 10 minutes. This process is called a 2nd mixing process.

Next, the mixed composition obtained through the above-mentioned first and second mixing steps was dropped on a 75-μm-thick release PET film, and another 75-μm-thick release PET film was further covered on the mixed composition. This laminated body which sandwiched the mixed composition in the release PET film was passed between two rollers with a pitch of 1.15 mm, and formed into a sheet shape. Then, this laminated body was put into an oven, and it heated at 150 degreeC for 15 minutes. Through this heating process, the (meth)acrylate monomer and the polyfunctional monomer are polymerized, and the (meth)acrylate polymer (A1-1) and the (meth)acrylate monomer are polymerized almost simultaneously. The polymer of the body undergoes a crosslinking reaction to obtain a heat-conductive pressure-sensitive-adhesive sheet-shaped molded body (hereinafter simply referred to as a "sheet") (G1). In addition, the polymerization conversion rate of the (meth)acrylate monomer was calculated from the residual monomer amount in the sheet (G1), and it was 99.9%. Table 2 shows the evaluation results of this sheet (G1).

(Examples 2-7, and Comparative Examples 1-6)

Sheets (G2 to G7) of Examples 2 to 7 were produced in the same manner as in Example 1, except that the blending of each substance in the second mixing step was changed as shown in Table 2 and Table 3, and the comparison Sheets of Examples 1-6 (GC1-GC6). Tables 2 and 3 show the evaluation results of these sheets. The details of the fillers used in Examples 2 to 7 and Comparative Examples 1 to 6 are as follows. In addition, in Examples 6 and 7 using expanded graphite, fillers other than expanded graphite were mixed in the 2nd mixing process, and then expanded graphite was mixed. When mixing the expanded graphite, the temperature of the above-mentioned Harbiter vessel was adjusted to 40° C., the rotational speed scale was set to 3, and stirring was performed under vacuum defoaming conditions of −0.1 MPaG for 10 minutes.

・Aluminum hydroxide without titanate treatment (B103)

Nippon Light Metal Co., Ltd., trade name "B103", average particle size: 8 μm, BET specific surface area: 3 m ² /g

・Aluminum hydroxide treated with titanate (B103T)

Nippon Light Metal Co., Ltd., trade name "B103T", average particle size: 8 μm

・Aluminum hydroxide without titanate treatment (B303)

Nippon Light Metal Co., Ltd., trade name "B303", average particle size: 30 μm

・Expanded graphite without titanate treatment (EC500)

Ito Graphite Industry Co., Ltd. product, brand name "EC500", average particle diameter: 30 micrometers, BET specific surface area: 0.2 m< ² >/g.

[Table 2]

.

[table 3]

.

As shown in Table 2, the sheets (G1 to G7) of the examples were all mixed compositions with appropriate viscosity, easy molding, excellent flame retardancy, and suppressed bleeding. On the other hand, as shown in Table 3, in the sheet (GC1) of Comparative Example 1, the addition amount of the titanate-treated thermally conductive filler (B2) was insufficient, and bleeding could not be sufficiently suppressed. In addition, for the sheet (GC2) of Comparative Example 2, the addition amount of the thermally conductive filler (B3) that was not treated with titanate was increased instead of the thermally conductive filler (B2) that was treated with titanate, thereby The viscosity of the mixed composition increased excessively, and the moldability was poor. In addition, the sheet (GC3) of Comparative Example 3 did not add the thermally conductive filler (B1) which had a large BET specific surface area and had not been subjected to titanate treatment, so bleeding could not be suppressed. In addition, for the sheet (GC4) of Comparative Example 4, since the addition amount of the thermally conductive filler (B1) without titanate treatment with a large BET specific surface area was too large, the viscosity of the mixed composition increased excessively, and molding Poor sex. On the other hand, in the sheet (GC5) of Comparative Example 5, the added amount of the thermally conductive filler (B1) having a large BET specific surface area and not subjected to titanate treatment (B1) was too small, so bleeding could not be suppressed. In addition, in the sheet (GC6) of Comparative Example 6, the addition amount of the titanate-treated thermally conductive filler (B2) was too large, so the viscosity of the mixed composition increased excessively, and the moldability was poor.

Claims (17)

1. A heat-conductive pressure-sensitive adhesive composition (F) obtained by performing a polymerization reaction and a crosslinking reaction in a mixed composition containing: (Meth)acrylic resin combination comprising (meth)acrylate polymer (A1), (meth)acrylate monomer (α1), and polyfunctional monomer (D) having multiple polymerizable unsaturated bonds (A) 100 parts by mass, 200 parts by mass or more and 450 parts by mass or less of a thermally conductive filler (B1) that has a BET specific surface area of 1.0 m ² /g or more and is not treated with titanate, Titanate-treated thermally conductive filler (B2) 120 parts by mass or more and 500 parts by mass or less, 200 to 600 parts by mass of a thermally conductive filler (B3) other than the thermally conductive filler (B1) and the thermally conductive filler (B2), and Phosphate (C) 40 to 120 parts by mass, The polymerization reaction is a polymerization reaction of the (meth)acrylate monomer (α1) and the polyfunctional monomer (D) having a plurality of polymerizable unsaturated bonds, and the crosslinking reaction is the Crosslinking reaction of (meth)acrylate polymer (A1) and/or polymer comprising structural units derived from said (meth)acrylate monomer (α1). 2. The thermally conductive pressure-sensitive adhesive composition (F) according to claim 1, wherein the thermally conductive filler (B1) has a BET specific surface area of 1.0 m ² /g or more without titanate treated at least one filler selected from metal hydroxides and metal oxides, The thermally conductive filler (B2) is a metal hydroxide treated with titanate, The thermally conductive filler (B3) is, in addition to the thermally conductive filler (B1) and the thermally conductive filler (B2), at least 1 filling. 3. The thermally conductive pressure-sensitive adhesive composition (F) according to claim 1 or 2, wherein the thermally conductive filler (B1) has a BET specific surface area of 1.0 m ² /g or more without titanium Ester-treated at least one filler selected from aluminum hydroxide and aluminum oxide, The thermally conductive filler (B2) is aluminum hydroxide treated with titanate, The thermally conductive filler (B3) is at least one filler selected from aluminum hydroxide, aluminum oxide, and expanded graphite, other than the thermally conductive filler (B1) and the thermally conductive filler (B2). 4. The heat conductive pressure-sensitive adhesive composition (F) according to any one of claims 1 to 3, wherein the (meth)acrylic resin composition (A) contains the (meth) ) acrylate polymer (A1) 5% by mass to 25% by mass, the (meth)acrylate monomer (α1) 74.8% by mass to 94.8% by mass, and the polymerizable unsaturated bond The polyfunctional monomer (D) is 0.2 mass % or more and 13 mass % or less. 5. A heat-conductive pressure-sensitive-adhesive sheet-shaped molded article (G) obtained by performing a polymerization reaction and formed by a cross-linking reaction, The mixed composition contains: (Meth)acrylic resin combination comprising (meth)acrylate polymer (A1), (meth)acrylate monomer (α1), and polyfunctional monomer (D) having multiple polymerizable unsaturated bonds (A) 100 parts by mass, 200 parts by mass or more and 450 parts by mass or less of a thermally conductive filler (B1) that has a BET specific surface area of 1.0 m ² /g or more and is not treated with titanate, Titanate-treated thermally conductive filler (B2) 120 parts by mass or more and 500 parts by mass or less, 200 to 600 parts by mass of a thermally conductive filler (B3) other than the thermally conductive filler (B1) and the thermally conductive filler (B2), and Phosphate (C) 40 to 120 parts by mass, The polymerization reaction is a polymerization reaction of the (meth)acrylate monomer (α1) and the polyfunctional monomer (D) having a plurality of polymerizable unsaturated bonds, and the crosslinking reaction is the Crosslinking reaction of (meth)acrylate polymer (A1) and/or polymer comprising structural units derived from said (meth)acrylate monomer (α1). 6. The heat-conductive pressure-sensitive-adhesive sheet-like molded article (G) according to claim 5, wherein the heat-conductive filler (B1) has a BET specific surface area of 1.0 m ² /g or more without titanium Ester-treated at least one filler selected from metal hydroxides and metal oxides, The thermally conductive filler (B2) is a metal hydroxide treated with titanate, The thermally conductive filler (B3) is, in addition to the thermally conductive filler (B1) and the thermally conductive filler (B2), at least 1 filling. 7. The heat-conductive pressure-sensitive-adhesive sheet-like molded article (G) according to claim 5 or 6, wherein the heat-conductive filler (B1) has a BET specific surface area of 1.0 m ² /g or more without At least one filler selected from aluminum hydroxide and aluminum oxide treated with titanate, The thermally conductive filler (B2) is aluminum hydroxide treated with titanate, The thermally conductive filler (B3) is at least one filler selected from aluminum hydroxide, aluminum oxide, and expanded graphite, other than the thermally conductive filler (B1) and the thermally conductive filler (B2). 8. The heat conductive pressure-sensitive-adhesive sheet-like molded article (G) according to any one of claims 5 to 7, wherein the (meth)acrylic resin composition (A) contains the ( The meth)acrylate polymer (A1) is 5% by mass to 25% by mass, the (meth)acrylate monomer (α1) is 74.8% by mass to 94.8% by mass, and the polymerizable non- The polyfunctional monomer (D) of a saturated bond is 0.2 mass % or more and 13 mass % or less. 9. A method for producing a heat-conductive pressure-sensitive adhesive composition (F), comprising the steps of preparing a mixed composition, and performing a polymerization reaction and a crosslinking reaction in the mixed composition, The mixed composition contains: (Meth)acrylic resin combination comprising (meth)acrylate polymer (A1), (meth)acrylate monomer (α1), and polyfunctional monomer (D) having multiple polymerizable unsaturated bonds (A) 100 parts by mass, 200 parts by mass or more and 450 parts by mass or less of a thermally conductive filler (B1) that has a BET specific surface area of 1.0 m ² /g or more and is not treated with titanate, Titanate-treated thermally conductive filler (B2) 120 parts by mass or more and 500 parts by mass or less, 200 to 600 parts by mass of a thermally conductive filler (B3) other than the thermally conductive filler (B1) and the thermally conductive filler (B2), and Phosphate (C) 40 to 120 parts by mass, The polymerization reaction is a polymerization reaction of the (meth)acrylate monomer (α1) and the polyfunctional monomer (D) having a plurality of polymerizable unsaturated bonds, and the crosslinking reaction is the Crosslinking reaction of (meth)acrylate polymer (A1) and/or polymer comprising structural units derived from said (meth)acrylate monomer (α1). 10. The method for producing a heat-conductive pressure-sensitive adhesive composition (F) according to claim 9, wherein the heat-conductive filler (B1) has a BET specific surface area of 1.0 m ² /g or more without titanate-treated at least one filler selected from metal hydroxides and metal oxides, The thermally conductive filler (B2) is a metal hydroxide treated with titanate, The thermally conductive filler (B3) is, in addition to the thermally conductive filler (B1) and the thermally conductive filler (B2), at least 1 filler. 11. The method for producing a heat-conductive pressure-sensitive adhesive composition (F) according to claim 9 or 10, wherein the heat-conductive filler (B1) has a BET specific surface area of 1.0 m ² /g or more, At least one filler selected from aluminum hydroxide and aluminum oxide that has not been titanate-treated, The thermally conductive filler (B2) is aluminum hydroxide treated with titanate, The thermally conductive filler (B3) is at least one filler selected from aluminum hydroxide, aluminum oxide, and expanded graphite, other than the thermally conductive filler (B1) and the thermally conductive filler (B2). 12 . The method for producing a heat-conductive pressure-sensitive adhesive composition (F) according to claim 9 , wherein the (meth)acrylic resin composition (A) contains the ( The meth)acrylate polymer (A1) is 5% by mass to 25% by mass, the (meth)acrylate monomer (α1) is 74.8% by mass to 94.8% by mass, and the polymerizable non- The polyfunctional monomer (D) of a saturated bond is 0.2 mass % or more and 13 mass % or less. 13. A method for producing a heat-conductive pressure-sensitive-adhesive sheet-like molded article (G), comprising the steps of preparing a mixed composition, forming the mixed composition into a sheet, or after making the mixed composition While forming into a sheet, the polymerization reaction and crosslinking reaction are carried out, The mixed composition contains: (Meth)acrylic resin combination comprising (meth)acrylate polymer (A1), (meth)acrylate monomer (α1), and polyfunctional monomer (D) having multiple polymerizable unsaturated bonds (A) 100 parts by mass, 200 parts by mass or more and 450 parts by mass or less of a thermally conductive filler (B1) that has a BET specific surface area of 1.0 m ² /g or more and is not treated with titanate, Titanate-treated thermally conductive filler (B2) 120 parts by mass or more and 500 parts by mass or less, 200 to 600 parts by mass of a thermally conductive filler (B3) other than the thermally conductive filler (B1) and the thermally conductive filler (B2), and Phosphate (C) 40 to 120 parts by mass, The polymerization reaction is a polymerization reaction of the (meth)acrylate monomer (α1) and the polyfunctional monomer (D) having a plurality of polymerizable unsaturated bonds, and the crosslinking reaction is the Crosslinking reaction of (meth)acrylate polymer (A1) and/or polymer comprising structural units derived from said (meth)acrylate monomer (α1). 14. The method for producing a heat-conductive pressure-sensitive-adhesive sheet-like molded article (G) according to claim 13, wherein the heat-conductive filler (B1) has a BET specific surface area of 1.0 m ² /g or more, At least one filler selected from metal hydroxides and metal oxides that has not been titanate-treated, The thermally conductive filler (B2) is a metal hydroxide treated with titanate, The thermally conductive filler (B3) is, in addition to the thermally conductive filler (B1) and the thermally conductive filler (B2), at least 1 filler. 15. The method for producing a heat-conductive pressure-sensitive-adhesive sheet-like molded article (G) according to claim 13 or 14, wherein the heat-conductive filler (B1) has a BET specific surface area of 1.0 m ² /g or more At least one filler selected from aluminum hydroxide and aluminum oxide without titanate treatment, The thermally conductive filler (B2) is aluminum hydroxide treated with titanate, The thermally conductive filler (B3) is at least one filler selected from aluminum hydroxide, aluminum oxide, and expanded graphite, other than the thermally conductive filler (B1) and the thermally conductive filler (B2). 16. The method for producing a heat-conductive pressure-sensitive-adhesive sheet-like molded article (G) according to any one of claims 13 to 15, wherein the (meth)acrylic resin composition (A) contains the 5% to 25% by mass of the (meth)acrylate polymer (A1), 74.8% to 94.8% by mass of the (meth)acrylate monomer (α1), and the The polyfunctional monomer (D) of a sexually unsaturated bond is 0.2 mass % or more and 13 mass % or less. 17. An electronic device comprising a heat sink and the thermally conductive pressure-sensitive adhesive composition (F) according to any one of claims 1 to 4 bonded to the heat sink, or comprising a heat sink and bonded to the heat sink. The thermally conductive pressure-sensitive-adhesive sheet-shaped molded article (G) as described in any one of Claims 5-8 of this radiator.