JP2015040262A - Heat-conductive pressure-sensitive adhesive composition, heat-conductive pressure-sensitive adhesive sheet-shaped molded product, method for producing thereof, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-conductive pressure-sensitive adhesive composition and a heat-conductive pressure-sensitive adhesive sheet-shaped molded product having excellent flexibility and good appearance while increasing the addition amount of an additive for improving heat conductivity.SOLUTION: There is provided a heat-conductive pressure-sensitive adhesive composition (F) which is obtained by polymerization reaction of at least a (meth)acrylic acid ester monomer (α1) in a mixed composition which comprises 100 pts.mass of a(meth)acrylic resin composition (A) containing a (meth)acrylic acid ester polymer (A1) and a (meth)acrylic acid ester monomer, 200 ps.mass or more and 1500 pts.mass or less of a conductive filler (B), 0.5 pt.mass or more and 30 pts.mass or less of a tackifier (C) and 1 pt.mass or more and 30 pts.mass or less of a dispersant and in which the dispersant (D) is a fatty acid ester of a polyhydric alcohol polymer.

Description

  The present invention relates to a heat conductive pressure-sensitive adhesive composition, a heat conductive pressure-sensitive adhesive sheet-like molded article, a production method thereof, and the heat conductive pressure-sensitive adhesive composition or the heat conductive pressure-sensitive adhesive sheet. The present invention relates to an electronic device provided with a shaped molded body.

  In recent years, electronic components such as plasma display panels (PDP), integrated circuit (IC) chips, and the like have increased in heat generation as their performance has increased. As a result, it is necessary to take countermeasures against functional failures due to temperature rise. In general, a method of dissipating heat by attaching a heat sink such as a metal heat sink, a heat radiating plate, or a heat radiating fin to a heat generator provided in an electronic component or the like is employed. In order to efficiently conduct heat conduction from the heat generator to the heat radiating body, a sheet-like member (heat conduction sheet) having high heat conductivity is used. In general, in applications where a heating element and a radiator are fixed, a composition having a pressure-sensitive adhesive property in addition to thermal conductivity (hereinafter referred to as a “thermal conductive pressure-sensitive adhesive composition”) or sheet. Member (hereinafter referred to as “thermally conductive pressure-sensitive adhesive sheet-like molded product”) is required.

  The heat conductive pressure-sensitive adhesive composition and the heat conductive pressure-sensitive adhesive sheet-like molded body are mainly intended to transfer heat from the heating element to the heat radiating body, and therefore it is preferable to increase the thermal conductivity. . In order to improve these thermal conductivities, it is conceivable to add various additives. For example, Patent Document 1 discloses a technique of adding an additive such as alumina or aluminum hydroxide to an acrylic heat conductive material.

JP 2010-1111757 A

  However, when a large amount of additives such as alumina and aluminum hydroxide are added, the flexibility of the heat conductive pressure-sensitive adhesive composition and the heat conductive pressure-sensitive adhesive sheet-like molded product is impaired, or defects such as pinholes are present. It may occur and the appearance may be deteriorated. The heat-conductive pressure-sensitive adhesive composition and the heat-conductive pressure-sensitive adhesive sheet-like molded body are required to be flexible so that they can adhere to the heat-generating body and the heat-radiating body in order to transfer heat from the heat-generating body to the heat-dissipating body.

  Accordingly, the present invention provides a thermally conductive pressure-sensitive adhesive composition and a thermally conductive pressure-sensitive adhesive sheet-like molded article having excellent flexibility and good appearance while increasing the amount of additives that improve thermal conductivity. The issue is to provide. Moreover, these manufacturing methods and the electronic device provided with this heat conductive pressure-sensitive-adhesive composition or this heat conductive pressure-sensitive-adhesive sheet-like molded object are provided.

  In the first aspect of the present invention, 100 parts by mass of (meth) acrylic resin composition (A) containing (meth) acrylic acid ester polymer (A1) and (meth) acrylic acid ester monomer (α1) The heat conductive filler (B) is 200 to 1500 parts by mass, the tackifier (C) is 0.5 to 30 parts by mass, and the dispersant (D) is 1 to 30 parts by mass. In a mixed composition in which the dispersant (D) is a fatty acid ester of a polyhydric alcohol polymer, at least a polymerization reaction of the (meth) acrylic acid ester monomer (α1) is performed. A heat conductive pressure-sensitive adhesive composition (F).

  In this specification, “(meth) acryl” means “acryl and / or methacryl”. The “thermally conductive filler” is added to improve the thermal conductivity of the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive adhesive sheet-like molded body (G) described later. It means a filler whose own thermal conductivity is 0.3 W / m · K or more. Furthermore, the “polymerization reaction of (meth) acrylate monomer (α1)” means a polymerization reaction for obtaining a polymer containing a structural unit derived from (meth) acrylate monomer (α1).

  In a second aspect of the present invention, 100 parts by mass of (meth) acrylic resin composition (A) containing (meth) acrylic acid ester polymer (A1) and (meth) acrylic acid ester monomer (α1) The heat conductive filler (B) is 200 to 1500 parts by mass, the tackifier (C) is 0.5 to 30 parts by mass, and the dispersant (D) is 1 to 30 parts by mass. And after forming the mixed composition in which the dispersant (D) is a fatty acid ester of a polyhydric alcohol polymer into a sheet shape or while forming the mixed composition into a sheet shape, ) Thermally conductive pressure-sensitive adhesive sheet-like molded product (G) obtained by polymerization reaction of acrylic acid ester monomer (α1).

  In the third aspect of the present invention, 100 parts by mass of (meth) acrylic resin composition (A) containing (meth) acrylic acid ester polymer (A1) and (meth) acrylic acid ester monomer (α1) The heat conductive filler (B) is 200 to 1500 parts by mass, the tackifier (C) is 0.5 to 30 parts by mass, and the dispersant (D) is 1 to 30 parts by mass. And a step of preparing a mixed composition in which the dispersant (D) is a fatty acid ester of a polyhydric alcohol polymer, and in the mixed composition, at least a (meth) acrylic acid ester monomer It is a manufacturing method of the heat conductive pressure-sensitive-adhesive composition (F) including the process of performing the superposition | polymerization reaction of ((alpha) 1).

  4th aspect of this invention is (meth) acrylic acid ester polymer (A1) and the (meth) acrylic acid ester monomer ((alpha) 1) containing (meth) acrylic resin composition (A) 100 mass parts. The heat conductive filler (B) is 200 to 1500 parts by mass, the tackifier (C) is 0.5 to 30 parts by mass, and the dispersant (D) is 1 to 30 parts by mass. And a step of preparing a mixed composition in which the dispersant (D) is a fatty acid ester of a polyhydric alcohol polymer, and after forming the mixed composition into a sheet form, or the mixed composition A method of producing a thermally conductive and pressure-sensitive adhesive sheet-like molded article (G) comprising a step of polymerizing at least a (meth) acrylic acid ester monomer (α1) while molding a product into a sheet form. .

  According to a fifth aspect of the present invention, there is provided a heating element and the heat conductive pressure-sensitive adhesive composition (F) of the first aspect of the present invention bonded to the heating element, or the heating element and the heating element. It is the electronic device provided with the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) of the 2nd aspect of the said this invention bonded.

  According to the present invention, the heat conductive pressure-sensitive adhesive composition and the heat conductive pressure-sensitive adhesive are increased while increasing the amount of the additive that improves the heat conductivity added to the heat conductive pressure-sensitive adhesive sheet-like molded body. It is possible to maintain or improve the flexibility and appearance of the composition and the heat conductive pressure-sensitive adhesive sheet-like molded body.

It is the figure which showed roughly the usage example of a heat conductive pressure sensitive adhesive composition (F) and a heat conductive pressure sensitive adhesive sheet-like molded object (G).

  In order to increase the thermal conductivity of the thermally conductive pressure-sensitive adhesive composition (F) and the thermally conductive pressure-sensitive adhesive sheet-like molded body (G), it is considered to increase the amount of the thermally conductive filler (B) added. It is done. However, when a large amount of the heat conductive filler (B) is added, the flexibility of the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) decreases, and the adherend There is a possibility that the adhesion with the surface deteriorates or a pinhole is generated. The inventors of the present invention increased the amount of the thermally conductive filler (B) to some extent by blending a predetermined amount of tackifier (C) and dispersant (D) into the (meth) acrylic resin composition (A). However, it was found that the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) can be obtained while maintaining flexibility and suppressing the generation of pinholes. .

1. Thermally conductive pressure-sensitive adhesive composition (F), thermally conductive pressure-sensitive adhesive sheet-like molded body (G)
The heat conductive pressure-sensitive adhesive composition (F) of the present invention comprises a (meth) acrylic resin composition (A) containing a (meth) acrylic acid ester polymer (A1) and a (meth) acrylic acid ester monomer (α1). Polymerization of at least a (meth) acrylate monomer (α1) in a mixed composition comprising A), a thermally conductive filler (B), a tackifier (C), and a dispersant (D). The reaction is performed.

  Moreover, the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) of this invention is at least (meth) acryl after shape | molding the said mixed composition in a sheet form, or shape | molding the said mixed composition in a sheet form. The polymerization reaction of the acid ester monomer (α1) is performed.

  The substance which comprises such a heat conductive pressure sensitive adhesive composition (F) and a heat conductive pressure sensitive adhesive sheet-like molded object (G) is demonstrated below.

<(Meth) acrylic resin composition (A)>
The (meth) acrylic resin composition (A) used in the present invention contains a (meth) acrylic acid ester polymer (A1) and a (meth) acrylic acid ester monomer (α1). It may contain a mer. In addition, when obtaining a heat conductive pressure-sensitive-adhesive composition (F) and a heat conductive pressure-sensitive-adhesive sheet-like molded object (G), the polymerization reaction of at least (meth) acrylic acid ester monomer ((alpha) 1) is carried out. Done. By performing the polymerization reaction, the polymer containing the structural unit derived from the (meth) acrylate monomer (α1) is mixed and / or partially bonded to the component of the (meth) acrylate polymer (A1). .

  In the present invention, the amount of the (meth) acrylic acid ester polymer (A1) and the (meth) acrylic acid ester monomer (α1) used is (mass) acrylic resin composition (A) being 100% by mass, The (meth) acrylate polymer (A1) is preferably 5% by mass or more and 25% by mass or less, and the (meth) acrylic acid ester monomer (α1) is preferably 75% by mass or more and 95% by mass or less. More preferably, the acrylic acid ester polymer (A1) is 10% by mass or more and 25% by mass or less, and the (meth) acrylic acid ester monomer (α1) is 75% by mass or more and 90% by mass or less. By setting the content ratio of the (meth) acrylic acid ester monomer (α1) within the above range, the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) are formed. It becomes easy to do.

((Meth) acrylic acid ester polymer (A1))
The (meth) acrylic acid ester polymer (A1) that can be used in the present invention is not particularly limited, but a (meth) acrylic acid ester monomer unit that forms a homopolymer having a glass transition temperature of −20 ° C. or lower. It is preferable to contain (a1) and a monomer unit (a2) having an organic acid group.

  The (meth) acrylate monomer (a1m) that gives the (meth) acrylate monomer unit (a1) is not particularly limited. For example, ethyl acrylate (the glass transition temperature of the homopolymer is − 24 ° C), n-propyl acrylate (-37 ° C), n-butyl acrylate (-54 ° C), sec-butyl acrylate (-22 ° C), n-heptyl acrylate (-60 ° C) ), N-hexyl acrylate (-61 ° C), n-octyl acrylate (-65 ° C), 2-ethylhexyl acrylate (-50 ° C), 2-methoxyethyl acrylate (-50 ° C) , 3-methoxypropyl acrylate (-75 ° C), 3-methoxybutyl acrylate (-56 ° C), ethoxymethyl acrylate (-50 ° C), n-octyl methacrylate (-2) ° C.), and the like methacrylic acid n- decyl (the -49 ° C.). Among these, n-butyl acrylate, 2-ethylhexyl acrylate, and 2-methoxyethyl acrylate are preferable, n-butyl acrylate and 2-ethylhexyl acrylate are more preferable, and 2-ethylhexyl acrylate is more preferable.

  These (meth) acrylic acid ester monomers (a1m) may be used individually by 1 type, and may use 2 or more types together.

  In the (meth) acrylic acid ester monomer (a1m), the monomer unit (a1) derived therefrom is preferably 80% by mass or more and 99.9% by mass in the (meth) acrylic acid ester polymer (A1). Hereinafter, it is used for polymerization in such an amount that it is more preferably 85 mass% or more and 99.5 mass% or less. When the amount of the (meth) acrylic acid ester monomer (a1m) is within the above range, the viscosity of the polymerization system at the time of polymerization can be easily maintained within an appropriate range.

  Next, the monomer unit (a2) having an organic acid group will be described. The monomer (a2m) that gives the monomer unit (a2) having an organic acid group is not particularly limited, but representative examples thereof include organic acid groups such as a carboxyl group, an acid anhydride group, and a sulfonic acid group. The monomer which has can be mentioned. In addition to these, monomers containing sulfenic acid groups, sulfinic acid groups, phosphoric acid groups, and the like can also be used.

  Specific examples of the monomer having a carboxyl group include, for example, α, β-ethylenically unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and α, such as itaconic acid, maleic acid, and fumaric acid. In addition to β-ethylenically unsaturated polyvalent carboxylic acid, α, β-ethylenically unsaturated polyvalent carboxylic acid partial esters such as monomethyl itaconate, monobutyl maleate and monopropyl fumarate can be used. Moreover, what has group which can be induced | guided | derived to a carboxyl group by hydrolysis etc., such as maleic anhydride and itaconic anhydride, can be used similarly.

  Specific examples of the monomer having a sulfonic acid group include allyl sulfonic acid, methallyl sulfonic acid, vinyl sulfonic acid, styrene sulfonic acid, α, β-unsaturated sulfonic acid such as acrylamide-2-methylpropane sulfonic acid, And salts thereof.

  As the monomer (a2m), among the monomers having an organic acid group exemplified above, a monomer having a carboxyl group is more preferable, and an α, β-ethylenically unsaturated monocarboxylic acid is more preferable. Acrylic acid or methacrylic acid is particularly preferred. These monomers are industrially inexpensive and can be easily obtained, have good copolymerizability with other monomer components, and are preferable in terms of productivity. In addition, a monomer (a2m) may be used individually by 1 type, and may use 2 or more types together.

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

  The monomer unit (a2) having an organic acid group is introduced into the (meth) acrylic acid ester polymer (A1) by polymerization of the monomer (a2m) having an organic acid group as described above. Although it is simple and preferable to perform, an organic acid group may be introduced by a known polymer reaction after the (meth) acrylic acid ester polymer (A1) is formed.

  The (meth) acrylic acid ester polymer (A1) may contain a monomer unit (a3) derived from a monomer (a3m) having a functional group other than an organic acid group. Examples of the functional group other than the organic acid group include a hydroxyl group, an amino group, an amide group, an epoxy group, and a mercapto group.

  Examples of the monomer having a hydroxyl group include (meth) acrylic acid hydroxyalkyl esters such as (meth) acrylic acid 2-hydroxyethyl and (meth) acrylic acid 3-hydroxypropyl.

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

  Examples of monomers having an amide group include α, β-ethylenically unsaturated carboxylic acid amide monomers such as acrylamide, methacrylamide, N-methylol acrylamide, N-methylol methacrylamide, and N, N-dimethylacrylamide. Can be mentioned.

  Examples of the monomer having an epoxy group include glycidyl (meth) acrylate and allyl glycidyl ether.

  As the monomer (a3m) having a functional group other than the organic acid group, one type may be used alone, or two or more types may be used in combination.

  In the monomer (a3m) having a functional group other than these organic acid groups, the monomer unit (a3) derived therefrom is 10% by mass or less in the (meth) acrylate polymer (A1). It is preferable to use it for polymerization in such an amount. By using the monomer (a3m) of 10% by mass or less, it becomes easy to keep the viscosity of the polymerization system during polymerization in an appropriate range.

  The (meth) acrylic acid ester polymer (A1) has a (meth) acrylic acid ester monomer unit (a1) that forms a homopolymer having the above-described glass transition temperature of −20 ° C. or lower, and an organic acid group. In addition to the monomer unit (a2) and the monomer unit (a3) having a functional group other than an organic acid group, a monomer derived from the monomer (a4m) copolymerizable with the above-described monomer. The monomer unit (a4) may be contained.

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

  Specific examples of the (meth) acrylate monomer other than the (meth) acrylate monomer (a1m) include methyl acrylate (homopolymer having a glass transition temperature of 10 ° C.), methyl methacrylate. (105 ° C.), ethyl methacrylate (63 ° C.), n-propyl methacrylate (25 ° C.), and n-butyl methacrylate (20 ° C.).

  Specific examples of the α, β-ethylenically unsaturated polyvalent carboxylic acid complete ester include dimethyl fumarate, diethyl fumarate, dimethyl maleate, diethyl maleate, dimethyl itaconate and the like.

  Specific examples of the alkenyl aromatic monomer include styrene, α-methylstyrene, methyl α-methylstyrene, vinyl toluene, and divinylbenzene.

  Specific examples of the conjugated diene monomer include 1,3-butadiene, 2-methyl-1,3-butadiene (synonymous with isoprene), 1,3-pentadiene, and 2,3-dimethyl-1,3-butadiene. , 2-chloro-1,3-butadiene, cyclopentadiene, and the like.

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

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

  Specific examples of the carboxylic acid unsaturated alcohol ester monomer include vinyl acetate.

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

  A monomer (a4m) may be used individually by 1 type, and may use 2 or more types together.

  In the monomer (a4m), the amount of 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). It is subjected to polymerization in such an amount.

  The (meth) acrylic acid ester polymer (A1) has a (meth) acrylic acid ester monomer (a1m) and an organic acid group, which form the homopolymer having a glass transition temperature of −20 ° C. or lower. Monomer (a2m), a monomer containing a functional group other than an organic acid group (a3m) used as necessary, and a monomer copolymerizable with these monomers used as needed It can be particularly suitably obtained by copolymerizing the monomer (a4m).

  The polymerization method for obtaining the (meth) acrylic acid ester polymer (A1) is not particularly limited, and may be any of solution polymerization, emulsion polymerization, suspension polymerization, bulk polymerization, and the like, or any other method. . However, among these polymerization methods, solution polymerization is preferable, and among them, solution polymerization using a carboxylic acid ester such as ethyl acetate or ethyl lactate or an aromatic solvent such as benzene, toluene or xylene is more preferable. In the polymerization, the monomer may be added in portions to the polymerization reaction vessel, but it is preferable to add the whole amount at once. The method for initiating the polymerization is not particularly limited, but it is preferable to use a thermal polymerization initiator as the polymerization initiator. The thermal polymerization initiator is not particularly limited, and for example, a peroxide polymerization initiator or an azo compound polymerization initiator can be used.

  Peroxide polymerization initiators include hydroperoxides such as t-butyl hydroperoxide, peroxides such as benzoyl peroxide and cyclohexanone peroxide, and persulfates such as potassium persulfate, sodium persulfate and ammonium persulfate. Can be mentioned. These peroxides can also be used as a redox catalyst in appropriate combination with a reducing agent.

  As the azo compound polymerization initiator, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile) And so on.

  Although the usage-amount of a polymerization initiator is not specifically limited, It is preferable that it is the range of 0.01 to 50 mass parts 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 completion of the polymerization reaction, the obtained 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) acrylic acid ester polymer (A1) can be obtained by placing the polymerization solution under reduced pressure and distilling off the polymerization solvent.

  The weight average molecular weight (Mw) of the (meth) acrylic acid ester polymer (A1) is measured by gel permeation chromatography (GPC method) and may be in the range of 1,000 to 1,000,000 in terms of standard polystyrene. Preferably, it is in the range of 100,000 or more and 500,000 or less. The weight average molecular weight of the (meth) acrylic acid ester polymer (A1) can be controlled by appropriately adjusting the amount of the polymerization initiator used in the polymerization and the amount of the chain transfer agent.

((Meth) acrylic acid ester monomer (α1))
The (meth) acrylate monomer (α1) is not particularly limited as long as it contains a (meth) acrylate monomer, but forms a homopolymer having a glass transition temperature of −20 ° C. or lower. It is preferable to contain the (meth) acrylic acid ester monomer (a5m).

  As an example of the (meth) acrylic acid ester monomer (a5m) that forms a homopolymer having a glass transition temperature of −20 ° C. or lower, it is used for the synthesis of a (meth) acrylic acid ester polymer (A1) (meta ) The same (meth) acrylate monomer as the acrylate monomer (a1m) can be mentioned. A (meth) acrylic acid ester monomer (a5m) may be used individually by 1 type, and may use 2 or more types together.

  The ratio of the (meth) acrylate monomer (a5m) in the (meth) acrylate monomer (α1) is preferably 50% by mass to 100% by mass, more preferably 75% by mass to 100% by mass. It is as follows. By making the ratio of the (meth) acrylic acid ester monomer (a5m) in the (meth) acrylic acid ester monomer (α1) in the above range, the heat conductive pressure-sensitive adhesive having excellent pressure-sensitive adhesiveness and flexibility. It becomes easy to obtain the agent composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G).

  The (meth) acrylic acid ester monomer (α1) is a (meth) acrylic acid ester monomer (a5m) that forms a homopolymer having a glass transition temperature of −20 ° C. or lower. It is good also as a mixture of the monomer (a6m) which has a polymerizable organic acid group.

  Examples of the monomer (a6m) include monomers having an organic acid group similar to those exemplified as the monomer (a2m) used for the synthesis of the (meth) acrylic acid ester polymer (A1). be able to. A monomer (a6m) may be used individually by 1 type, and may use 2 or more types together.

  The ratio of the monomer (a6m) in the (meth) acrylic acid ester monomer (α1) is preferably 30% by mass or less, and more preferably 10% by mass or less. By setting the ratio of the monomer (a6m) in the (meth) acrylic acid ester monomer (α1) to the above range, the heat conductive pressure-sensitive adhesive composition (F) excellent in pressure-sensitive adhesiveness and flexibility. And it becomes easy to obtain a heat conductive pressure-sensitive-adhesive sheet-like molded object (G).

  The (meth) acrylic acid ester monomer (α1), in addition to the (meth) acrylic acid ester monomer (a5m) and the monomer (a6m) having an organic acid group that can be optionally copolymerized, It is good also as a mixture containing the monomer (a7m) copolymerizable with these.

  Examples of the monomer (a7m) include the monomer (a3m) used for the synthesis of the (meth) acrylic acid ester polymer (A1) and the same amount as those exemplified as the monomer (a4m). The body can be mentioned. A monomer (a7m) may be used individually by 1 type, and may use 2 or more types together.

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

(Polyfunctional monomer)
In the present invention, a polyfunctional monomer can also be used in the (meth) acrylic resin composition (A). Usually, at the time of polymerization such as radical thermal polymerization, a certain degree of crosslinking reaction proceeds without using a polyfunctional monomer. However, a polyfunctional monomer may be used in order to form a desired amount of a crosslinked structure more reliably.

  As the polyfunctional monomer that can be used in the present invention, a monomer that is copolymerizable with the monomer contained in the (meth) acrylic acid ester monomer (α1) is used. The polyfunctional monomer has a plurality of polymerizable unsaturated bonds, and preferably has the unsaturated bond at the terminal. By using such a polyfunctional monomer, intramolecular and / or intermolecular crosslinking can be introduced into the copolymer to increase the cohesive force as a pressure-sensitive adhesive.

  Examples of the polyfunctional monomer include 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, ditrimethylolpropane tri Multifunctional (meth) acrylates such as (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and 2,4-bis (trichloromethe) Other substituted triazines, such as Le) -6-p-methoxystyrene-5-triazine, etc. monoethylenically unsaturated aromatic ketones such as 4-acryloxy benzophenone can be used. Among these, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, and pentaerythritol tetra (meth) acrylate are preferable. A polyfunctional monomer may be used individually by 1 type, and may use 2 or more types together.

  The amount of the polyfunctional monomer used is preferably 0.5% by mass or more and 10% by mass or less, and 0.5% by mass or more and 5% by mass or less, with the (meth) acrylic resin composition (A) being 100% by mass. It is more preferable that the amount is not more than mass%. By setting the amount of the polyfunctional monomer used within the above range, an appropriate cohesive force is imparted to the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G). It becomes easy.

<Polymerization initiator>
When obtaining the heat conductive pressure sensitive adhesive composition (F) and the heat conductive pressure sensitive adhesive sheet-like molded body (G), the components contained in the (meth) acrylic resin composition (A) are polymerized as described above. . In order to accelerate the polymerization reaction, it is preferable to use a polymerization initiator. Examples of the polymerization initiator include a photopolymerization initiator, an azo thermal polymerization initiator, and an organic peroxide thermal polymerization initiator. However, from the viewpoint of imparting strong adhesive force to the obtained heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G), an organic peroxide thermal polymerization initiator is used. Is preferably used.

  Various known photopolymerization initiators can be used as the photopolymerization initiator. Of these, acylphosphine oxide compounds are preferred. Examples of the acylphosphine oxide compound that is a preferred photopolymerization initiator include bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide and 2,4,6-trimethylbenzoyldiphenylphosphine oxide.

  As the azo thermal polymerization initiator, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile) ) And the like.

  As the organic peroxide thermal polymerization initiator, hydroperoxide such as t-butyl hydroperoxide, benzoyl peroxide, cyclohexanone peroxide, 1,6-bis (t-butylperoxycarbonyloxy) hexane, 1,1-bis ( and a peroxide such as t-butylperoxy) -3,3,5-trimethylcyclohexanone. However, those that do not release volatile substances that cause odor during thermal decomposition are preferred. Among organic peroxide thermal polymerization initiators, those having a 1-minute half-life temperature of 100 ° C. or more and 170 ° C. or less are preferable.

The amount of the polymerization initiator used is preferably 0.01 parts by mass or more and 10 parts by mass or less, and 0.1 parts by mass or more and 5 parts by mass with respect to 100 parts by mass of the (meth) acrylic resin composition (A). More preferably, it is 0.3 to 2 parts by mass.
By making the usage-amount of a polymerization initiator into the said range, it becomes easy to make the polymerization conversion of a (meth) acrylic acid ester monomer ((alpha) 1) into an appropriate range, and a heat conductive pressure sensitive adhesive composition (F) and It becomes easy to prevent the monomer odor from remaining in the heat conductive pressure-sensitive adhesive sheet-like molded body (G).
The polymerization conversion rate of the (meth) acrylic acid ester monomer (α1) is preferably 95% by mass or more. If the polymerization conversion rate of the (meth) acrylic acid ester monomer (α1) is 95% by mass or more, the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded product (G). It is easy to prevent the monomer odor from remaining on the surface.
Moreover, by making the usage-amount of a polymerization initiator into the said range, superposition | polymerization reaction will advance excessively and a heat conductive pressure-sensitive-adhesive sheet-like molded object (G) may become uneven | corrugated on the surface without becoming a smooth sheet form. It becomes easy to prevent the situation that a pinhole occurs.

<Thermal conductive filler (B)>
Next, the heat conductive filler (B) will be described. As the heat conductive filler (B), the heat conductivity of the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) can be improved by adding, A filler having its own thermal conductivity of 0.3 W / m · K or more can be used.

  Specific examples of the thermally conductive filler (B) include aluminum hydroxide, gallium hydroxide, indium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide and other metal hydroxides; aluminum oxide ( Alumina), metal oxides such as magnesium oxide and zinc oxide; metal carbonates such as calcium carbonate and aluminum carbonate; metal nitrides such as boron nitride and aluminum nitride; zinc borate hydrate; kaolin clay; calcium aluminate water Examples thereof include: Japanese; Dosonite; Silica; Expanded graphite powder, artificial graphite, carbon black, carbon fiber, and other carbon-containing conductive fillers. Among these, metal hydroxides and metal oxides are preferable, and aluminum hydroxide and aluminum oxide (alumina) are particularly preferable. A heat conductive filler (B) may be used individually by 1 type, and may use 2 or more types together.

  The amount of the heat conductive filler (B) added to the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) of the present invention is the (meth) acrylic resin composition ( A) It is 200 mass parts or more and 1500 mass parts or less with respect to 100 mass parts, it is preferable that they are 250 mass parts or more and 1300 mass parts or less, and it is more preferable that they are 900 mass parts or more and 1300 mass parts or less. Mixing which is a precursor of the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) by setting the content of the heat conductive filler (B) to the upper limit or less. It becomes easy to suppress that the viscosity of a composition becomes high too much. Therefore, even if it becomes difficult to shape | mold a heat conductive pressure sensitive adhesive composition (F) and a heat conductive pressure sensitive adhesive sheet-like molded object (G), and it can shape | mold, a heat conductive pressure sensitive adhesive composition (F). In addition, it is possible to prevent a situation in which the hardness of the heat conductive pressure-sensitive adhesive sheet-like molded body (G) increases and the shape followability (adhesion to the adherend) decreases. On the other hand, by setting the content of the heat conductive filler (B) to the above lower limit or more, the heat conductivity of the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G). It is easy to exert the effect of improving the sheet, and the sheet shape maintenance property and sheet tearing property shown in the examples described later are excellent.

<Tackfire (C)>
Next, the tackifier (C) will be described. As the tackifier (C), a known tackifier (tackifier) which is compatible with the (meth) acrylic resin composition (A) and does not contain a solvent can be used without any particular limitation. For example, a rosin tackifier, a terpene tackifier, and a petroleum resin tackifier can be used as the tackifier (C).

  Examples of rosin-based tackifiers include esters of rosin acid and glycerin and pentaerythritol, which are mainly composed of abietic acid in pine crabs and pine root oil, and hydrogenated products and disproportionates thereof. More specifically, gum rosin, tall oil rosin, wood rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, modified rosin, rosin ester (rosin diol) and the like can be mentioned.

  Examples of the terpene tackifier include those obtained by polymerizing terpene oil contained in pine or natural terpene contained in orange peel. More specifically, a terpene resin, an aromatic modified terpene resin, a terpene phenol resin, a hydrogenated terpene resin, and the like can be given.

  Examples of the petroleum resin tackifier include aliphatic, alicyclic and aromatic resins made from petroleum. More specifically, C5 petroleum resin, C9 petroleum resin, copolymer petroleum resin, alicyclic saturated hydrocarbon resin, styrene petroleum resin and the like can be mentioned.

  As the tackifier (C), a rosin tackifier is preferable, and a rosin ester is more preferable.

  The amount of the tackifier (C) used in the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) of the present invention is the (meth) acrylic resin composition (A). Is 100 parts by mass, preferably 0.5 parts by mass to 30 parts by mass, and preferably 4 parts by mass to 30 parts by mass. While adding a predetermined amount of tackifier (C) as described above and adding a predetermined amount of dispersant (D) as described later, the amount of heat conductive filler (B) added is increased from the conventional amount. In addition, the flexibility of the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) can be maintained, and the appearance defects such as pinholes can be suppressed.

<Dispersant (D)>
Next, the dispersant (D) will be described. The dispersant (D) is preferably a fatty acid ester of a polyhydric alcohol polymer. Examples of the fatty acid ester of the polyhydric alcohol polymer include polyglycerin fatty acid ester, polysorbitan fatty acid ester, and polypropylene glycol fatty acid ester. Of these, polyglycerol fatty acid esters are more preferable.

Examples of the polyglycerin fatty acid ester include polyglycerin condensed ricinoleic acid ester, polyglycerin ricinoleic acid ester, polyglycerin oleic acid ester, polyglycerin stearic acid ester, and the like. Among them, polyglycerin condensed ricinoleic acid ester is particularly preferable.
Examples of the polysorbitan fatty acid ester include polysorbitan condensed ricinoleic acid ester, polysorbitan ricinoleic acid ester, polysorbitan oleic acid ester, polysorbitan stearic acid ester, and the like.
Examples of the polypropylene glycol fatty acid ester include polypropylene glycol condensed ricinoleic acid ester, polypropylene glycol ricinoleic acid ester, polypropylene glycol oleic acid ester, and polypropylene glycol stearic acid ester.

  The condensed ricinoleic acid is as follows. Although ricinoleic acid is a compound having both a carboxyl group and a hydroxyl group, a compound obtained by the esterification reaction between the carboxyl group possessed by ricinoleic acid and the hydroxyl group possessed by ricinoleic acid, which is a separate molecule, is referred to as “condensed ricinolein”. Referred to as "acid". The polyglycerin condensed ricinoleic acid ester is obtained by an esterification reaction between a carboxyl group in condensed ricinoleic acid and a hydroxyl group in a compound having a hydroxyl group.

  Moreover, it is preferable that the number average molecular weights of a dispersing agent (D) are 1,000-10,000, and it is preferable that a dispersing agent (D) is a liquid under the temperature of 10 to 40 degreeC.

  The amount of the dispersant (D) used in the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) of the present invention is the (meth) acrylic resin composition (A). 1 part by mass to 30 parts by mass, preferably 10 parts by mass to 30 parts by mass. By containing a predetermined amount of the dispersant (D) and the above-described tackifier (C), the heat conductive pressure-sensitive adhesive composition (F) can be used even if the amount of the heat conductive filler (B) is increased from the conventional amount. And the softness | flexibility of a heat conductive pressure-sensitive-adhesive sheet-like molded object (G) can be maintained, and generation | occurrence | production of appearance defects, such as a pinhole, can be suppressed.

<Phosphate ester>
It is preferable to use phosphate ester for the heat conductive pressure sensitive adhesive composition (F) and the heat conductive pressure sensitive adhesive sheet-like molded product (G) of the present invention. By using phosphate ester, it becomes easy to give the flame retardance excellent in the heat conductive pressure-sensitive-adhesive composition (F) and the heat conductive pressure-sensitive-adhesive sheet-like molded object (G).

  The phosphate ester used in the present invention preferably has a viscosity at 25 ° C. of 3000 mPa · s or more. By making the viscosity of the phosphate ester in the above range, it becomes easy to prevent the moldability of the heat conductive pressure-sensitive adhesive composition (F) or the heat conductive pressure-sensitive adhesive sheet-like molded body (G) from being deteriorated. . In the present invention, the “viscosity” of the phosphate ester means the viscosity measured by the method described below.

(Method for measuring viscosity of phosphate ester)
The viscosity of the phosphate ester is measured using a B-type viscometer (manufactured by Tokyo Keiki Co., Ltd.) according to the following procedure.
(1) Weigh 300 ml of phosphate ester in a normal temperature environment and place it in a 500 ml container.
(2) Stirring rotor No. Select one from 1, 2, 3, 4, 5, 6, and 7 and attach to the viscometer.
(3) The container containing the phosphate ester is placed on the viscometer, and the rotor is submerged in the condensed phosphate ester in the container. At this time, the dent which becomes a mark of a rotor sinks so that it may just come to the liquid interface of phosphate ester.
(4) The rotation speed is selected from 20, 10, 4, and 2.
(5) Turn on the stirring switch and read the value after 1 minute.
(6) The value obtained by multiplying the read numerical value by the coefficient A is the viscosity [mPa · s].
The coefficient A is the selected rotor No. as shown in Table 1 below. And the number of revolutions.

  Moreover, it is preferable that the phosphate ester used for this invention is always a liquid in the temperature range of 15 degreeC or more and 100 degrees C or less under atmospheric pressure. If the phosphate ester is liquid when mixed, the workability is good, and it is easy to form the heat conductive pressure-sensitive adhesive composition (F) or the heat conductive pressure-sensitive adhesive sheet-like molded body (G). become. When forming a heat conductive pressure-sensitive adhesive composition (F) or a heat conductive pressure-sensitive adhesive sheet-like molded product (G) containing a phosphate ester, the heat conductive pressure sensitive in an environment of 15 ° C. or more and 100 ° C. or less. It is preferable to mix each substance which comprises an adhesive composition (F) or a heat conductive pressure-sensitive-adhesive sheet-like molded object (G). By setting the temperature during mixing in the above range, the glass transition temperature of the (meth) acrylic resin composition (A) is set to be equal to or higher than the volatilization or polymerization of monomers contained in the (meth) acrylic resin composition (A). Since it becomes easy to prevent the reaction from starting, the environmental performance and workability can be improved.

  In the present invention, either a condensed phosphate ester or a non-condensed phosphate ester can be used as the phosphate ester. As used herein, “condensed phosphate ester” means one having a plurality of phosphate ester moieties in one molecule, and “non-condensed phosphate ester” means one phosphate ester moiety in one molecule. It means something that exists only. Specific examples of phosphate esters that satisfy the conditions described so far are listed below.

  Specific examples of the condensed phosphate ester include aromatic condensed phosphate esters such as 1,3-phenylene bis (diphenyl phosphate), bisphenol A bis (diphenyl phosphate), resorcinol bis (diphenyl phosphate); polyoxyalkylene bisdichloroalkyl And halogen-containing condensed phosphates such as phosphates; non-aromatic non-halogen-based condensed phosphates; Among these, aromatic condensed phosphates are preferred because of their relatively low specific gravity, no danger of releasing harmful substances (such as halogens), and availability, and 1,3-phenylenebis (diphenyl phosphate). ), Bisphenol A bis (diphenyl phosphate) is more preferred.

  Specific examples of the non-condensed phosphate ester include aromatics such as triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, cresyl-2,6-xylenyl phosphate, 2-ethylhexyl diphenyl phosphate And phosphoric acid esters; halogen-containing phosphoric acid esters such as tris (β-chloropropyl) phosphate, trisdichloropropylphosphate, tris (tribromoneopentyl) phosphate; Of these, aromatic phosphates are preferred because no harmful substances (such as halogen) are generated.

  A phosphate ester may be used individually by 1 type, and may use 2 or more types together.

  When using phosphate ester for the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded product (G) of the present invention, the amount thereof is (meth) acrylic resin composition (A ) Is 100 parts by mass, preferably 100 parts by mass or less, more preferably 80 parts by mass or less, and still more preferably 30 parts by mass or more and 70 parts by mass or less. By making content of phosphate ester into the said range, it becomes easy to maintain the adhesiveness of a heat conductive pressure-sensitive-adhesive composition (F) or a heat conductive pressure-sensitive-adhesive sheet-like molded object (G).

<Performance>
According to the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) of the present invention, the tackifier (C) and the dispersion are dispersed in the (meth) acrylic resin composition (A). By blending a predetermined amount of the agent (D), the flexibility can be maintained and the occurrence of pinholes can be suppressed even when the amount of the thermally conductive filler (B) added is increased to some extent. Therefore, according to the present invention, the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) having excellent thermal conductivity and excellent flexibility and appearance are obtained. Can be obtained.

<Other additives>
The thermally conductive pressure-sensitive adhesive composition (F) and thermally conductive pressure-sensitive adhesive sheet-like molded body (G) of the present invention include, in addition to the materials described above, the above-described thermally conductive pressure-sensitive adhesive of the present invention. Various known additives can be added within a range in which the performance of the adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) can be satisfied.
Known additives include foaming agents (including foaming aids); flame retardant thermally conductive inorganic compounds such as metal hydroxides and metal salt hydrates other than the above-described thermally conductive filler (B); glass Fiber: Thermally conductive inorganic compound other than the above-mentioned thermally conductive filler (B), such as expanded graphite powder and PITCH-based carbon fiber; External cross-linking agent; Pigment such as carbon black and titanium dioxide; Other filler such as clay Nanoparticles such as fullerenes and carbon nanotubes; antioxidants such as polyphenols, hydroquinones, and hindered amines; thickeners such as acrylic polymer particles, fine silica, and magnesium oxide.

2. Manufacturing method Next, the manufacturing method of a heat conductive pressure sensitive adhesive composition (F) and a heat conductive pressure sensitive adhesive sheet-like molded object (G) is demonstrated.

  The heat conductive pressure-sensitive adhesive composition (F) is prepared by mixing the substances described so far to prepare a mixed composition, and then, in the mixed composition, at least a (meth) acrylic acid ester monomer ( It can be obtained by carrying out the polymerization reaction α1).

That is, the manufacturing method of the heat conductive pressure-sensitive adhesive composition (F) of the present invention includes (meth) acrylic acid ester polymer (A1) and (meth) acrylic acid ester monomer (α1). A step of producing a mixed composition comprising an acrylic resin composition (A), a thermally conductive filler (B), a tackifier (C), and a dispersant (D), and in the mixed composition At least a step of polymerizing the (meth) acrylic acid ester monomer (α1).
In addition, the substance which can be used other than that, the preferable content ratio of each substance, etc. are as above-mentioned, and detailed description is abbreviate | omitted here.

  The heat conductive pressure-sensitive adhesive sheet-like molded product (G) of the present invention is prepared by mixing each of the substances described so far to prepare a mixed composition, and molding the mixed composition into a sheet shape, or It can be obtained by performing a polymerization reaction of at least the (meth) acrylic acid ester monomer (α1) while forming the mixed composition into a sheet.

That is, the manufacturing method of the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) of this invention contains the (meth) acrylic acid ester polymer (A1) and the (meth) acrylic acid ester monomer ((alpha) 1) ( A step of producing a mixed composition comprising a (meth) acrylic resin composition (A), a thermally conductive filler (B), a tackifier (C), and a dispersant (D); and the mixed composition A step of performing a polymerization reaction of at least the (meth) acrylic acid ester monomer (α1) while forming the mixture composition into a sheet shape.
In addition, the substance which can be used other than that, the preferable content ratio 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 product (G) of the present invention, it is preferable to heat the polymerization reaction. For the 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) proceeds. The temperature range varies depending on the type of polymerization initiator used, but is preferably 100 ° C. or higher and 200 ° C. or lower, and more preferably 130 ° C. or higher and 180 ° C. or lower.

  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 in a sheet form is not specifically limited. Suitable methods include, for example, a method of forming a sheet by applying the mixed composition on a process paper such as a release-treated polyester film, and the mixing between two release-processed papers. A method of forming a sheet by pressing between the rolls sandwiching the composition, and a method of forming the sheet by extruding the mixed composition using an extruder and controlling the thickness through a die at that time Etc. Although the process paper is not particularly limited, for example, a release-treated polyethylene terephthalate film or a release-treated polyethylene naphthalate film can be used. Among these, a polyethylene terephthalate film subjected to a release treatment is preferable.

  Since the generation of pinholes can be suppressed by blending a predetermined amount of the tackifier (C) and the dispersant (D) as described above, the heat conductive pressure-sensitive adhesive sheet-like molded body (G) is formed thinly. Can do. The thickness of the heat conductive pressure-sensitive adhesive sheet-like molded body (G) can be set to, for example, 0.05 mm or more and 5 mm or less. By reducing the thickness of the heat conductive pressure-sensitive adhesive sheet-like molded article (G), the thermal resistance in the thickness direction of the heat conductive pressure-sensitive adhesive sheet-like molded article (G) can be reduced. From this viewpoint, the upper limit of the thickness of the heat conductive pressure-sensitive adhesive sheet-like molded body (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 product (G) is preferably 0.1 mm. By applying a certain thickness to the heat conductive pressure-sensitive adhesive sheet-like molded body (G), air is applied when the heat-conductive pressure-sensitive adhesive sheet-like molded body (G) is applied to the heating element and the heat radiating body. It becomes easy to prevent entrainment, and as a result, increase in thermal resistance is prevented, and workability in the step of attaching to the adherend is easily improved.

  Moreover, a heat conductive pressure-sensitive-adhesive sheet-like molded object (G) can also be shape | molded on the single side | surface or both surfaces of a base material. The material which comprises the said base material is not specifically limited. Specific examples of the substrate include metals having excellent thermal conductivity such as aluminum, copper, stainless steel, and beryllium copper, and polymers having excellent thermal conductivity such as foils of alloys and thermally conductive silicone. And a sheet-like material made of the above, a heat-conductive plastic film containing a heat-conductive additive, various non-woven fabrics, a glass cloth, and a honeycomb structure. Plastic films include polyimide, polyethylene terephthalate, polyethylene naphthalate, polytetrafluoroethylene, polyether ketone, polyethersulfone, polymethylpentene, polyetherimide, polysulfone, polyphenylene sulfide, polyamideimide, polyesterimide, aromatic polyamide, etc. A heat-resistant polymer film can be used.

3. Use Example Since the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) of the present invention have high heat conductivity and pressure-sensitive adhesiveness, By interposing between a heat generating body and a heat radiating body, it can be used for applications such as efficiently conducting heat conduction from the heat generating body to the heat radiating body. Moreover, the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) of the present invention are attached to an electronic component which is a heating element provided in an electronic device, and the electronic component Can be used as part. The usage example of the heat conductive pressure-sensitive-adhesive composition (F) of this invention and a heat conductive pressure-sensitive-adhesive sheet-like molded object (G) is demonstrated referring FIG. FIG. 1 is a diagram for explaining an example of use of a heat conductive pressure-sensitive adhesive sheet-like molded body (G).

FIG. 1A is a perspective view schematically showing a part of an electronic device such as a personal computer. FIG. 1A shows a substrate 1, an electronic component 2 that is a heating element installed on the substrate 1, a heat sink 3 that is a radiator, and a thermally conductive pressure-sensitive adhesive disposed between the electronic component 2 and the heat sink 3. The sheet-like molded article (G) 4 is shown.
As shown in FIG. 1 (A), a heat conductive pressure-sensitive adhesive sheet-like molded body (G) 4 is sandwiched and fixed between the electronic component 2 and the heat sink 3, thereby forming a heat conductive pressure-sensitive adhesive sheet-like mold. Due to the pressure-sensitive adhesiveness of the body (G) 4, the heat conductive pressure-sensitive adhesive sheet-like molded body (G) 4 is bonded to the electronic component 2 and the heat sink 3. And since the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) 4 has high heat conductivity, the heat | fever emitted by the electronic component 2 is a heat conductive pressure-sensitive-adhesive sheet-like molded object (G) 4 Is efficiently transmitted to the heat sink 3 through the heat sink 3 and radiated from the heat sink 3.

FIG. 1B schematically shows a state in which the NPN transistor 12a and the PNP transistor 12b, which are heating elements, are attached to the heat sink 13, which is a radiator, through the heat conductive pressure-sensitive adhesive sheet-like molded bodies (G) 14, 14. FIG.
As shown in FIG. 1B, by attaching the NPN transistor 12a and the PNP transistor 12b to the heat sink 13 via the heat conductive pressure-sensitive adhesive sheet-like molded bodies (G) 14 and 14, the heat conductive feeling is obtained. Due to the pressure-sensitive adhesive property of the pressure-adhesive sheet-like molded body (G) 14, one heat conductive pressure-sensitive adhesive sheet-like molded body (G) 14 is bonded to the NPN transistor 12a and the heat sink 13, and the other heat The conductive pressure-sensitive adhesive sheet-like molded body (G) 14 is bonded to the PNP transistor 12 b and the heat sink 13. And since the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) 14 has high heat conductivity, the heat | fever emitted by the NPN transistor 12a and the PNP transistor 12b is a heat conductive pressure-sensitive-adhesive sheet-like molded object. (G) It is efficiently transmitted to the heat sink 13 via 14, 14 and is radiated from the heat sink 13. At this time, both the NPN transistor 12a and the PNP transistor 12b are attached to one heat sink 13 via the heat conductive pressure-sensitive adhesive sheet-like molded bodies (G) 14 and 14 having high heat conductivity. The temperature difference between the NPN transistor 12a and the PNP transistor 12b can be suppressed.

FIG. 1C is a cross-sectional view schematically showing a state in which two transistors 22 and 22 that are heating elements are fixed via a heat conductive pressure-sensitive adhesive sheet-like molded body (G) 24.
As shown in FIG. 1 (C), two heat generating elements 22 and 22 are fixed via a heat conductive pressure-sensitive adhesive sheet-like molded body (G) 24, thereby forming a heat conductive pressure-sensitive adhesive sheet. Due to the pressure-sensitive adhesive property of the molded body (G) 24, the thermally conductive pressure-sensitive adhesive sheet-shaped molded body (G) 24 is bonded to the two heating elements 22 and 22. And since the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) 24 has high heat conductivity, if one temperature of two heat generating bodies 22 and 22 becomes high compared with the other, from one side. Since heat can be quickly transmitted to the other side, it is possible to suppress the occurrence of a temperature difference between the two heating elements 22 and 22.

  In addition, although the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) was used in the example shown in FIG. 1, it replaces with a heat conductive pressure-sensitive-adhesive sheet-like molded object (G), and a heat conductive pressure-sensitive-adhesive composition. A thing (F) can also be used similarly. In the above example, the heat sink is used as the heat radiating body. However, a housing of an electronic component or the like can be used as the heat radiating body. Hereinafter, other usage examples of the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) of the present invention will be described.

  As described above, the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) of the present invention can be used as a part of an electronic component provided in an electronic device. . Specific examples of the electronic device and electronic component include electroluminescence (EL), a component around a heat generating part in a device having a light emitting diode (LED) light source, a component around a power device such as an automobile, a fuel cell, a solar cell, and a battery. , Devices and parts having heat generating parts such as mobile phones, personal digital assistants (PDAs), notebook computers, liquid crystal panels, surface conduction electron-emitting device displays (SED), plasma display panels (PDP), or integrated circuits (ICs) Can be mentioned.

  In addition, as an example of the usage method for the electronic device of the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) of the present invention, an LED light source is exemplified below. Examples of usage can be mentioned. That is, it is directly attached to the LED light source; sandwiched between the LED light source and a heat dissipation material (heat sink, fan, Peltier element, heat pipe, graphite sheet, etc.); , Heat pipe, graphite sheet, etc.); used as a housing surrounding the LED light source; pasted on a housing surrounding the LED light source; filling a gap between the LED light source and the housing; Examples of LED light source applications include backlight devices for display devices having transmissive liquid crystal panels (TVs, mobile phones, PCs, notebook PCs, PDAs, etc.); vehicle lamps; industrial lighting; commercial lighting; Lighting; and the like.

  Specific examples other than the LED light source include the following. That is, PDP panel; IC heating part; Cold cathode tube (CCFL); Organic EL light source; Inorganic EL light source; High luminance light emitting LED light source; High luminance light emitting organic EL light source; And so on.

  Furthermore, as a usage method of the heat conductive pressure-sensitive-adhesive composition (F) and heat conductive pressure-sensitive-adhesive sheet-like molded object (G) of this invention, affixing on the housing | casing of an apparatus etc. can be mentioned. For example, when used in a device provided in an automobile or the like, it is affixed inside a casing provided in the automobile; affixed outside the casing provided in the automobile; a heat generating part (inside the casing provided in the automobile) Connecting the car navigation / fuel cell / heat exchanger) and the housing; affixing to a heat sink connected to the heat generating part (car navigation / fuel cell / heat exchanger) in the housing of the automobile; Etc.

  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 be used with the same method other than a motor vehicle. For example, personal computers; homes; TVs; mobile phones; vending machines; refrigerators; solar cells; surface-conduction electron-emitting device displays (SEDs); organic EL displays; inorganic EL displays; Organic EL display; laptop computer; PDA; fuel cell; semiconductor device; rice cooker; washing machine; laundry dryer; optical semiconductor device combining optical semiconductor elements and phosphors; Is mentioned.

  Furthermore, the heat-conductive pressure-sensitive adhesive composition (F) and the heat-conductive pressure-sensitive adhesive sheet-like molded body (G) of the invention are not limited to the above-described usage methods, and may be used in other methods depending on the application. Is possible. For example, used for heat uniformity of carpets and warm mats, etc .; used as LED light source / heat source sealant; used as solar cell sealant; used as solar cell backsheet Used between the backsheet of the solar cell and the roof; used inside the heat insulating layer inside the vending machine; used inside the housing of the organic EL lighting with a desiccant and a hygroscopic agent; organic EL lighting Use with desiccant and hygroscopic agent on the heat conductive layer inside the housing of the LED; Use with desiccant and hygroscopic agent on the heat conductive layer and heat dissipation layer inside the housing of the organic EL lighting Used for heat conduction layer inside the housing of organic EL lighting, epoxy heat dissipation layer, and on top of it with desiccant and moisture absorbent; cooling equipment, clothing, towels, sheets, etc. for cooling humans and animals Used on the opposite side of the body to the member Used as a pressure member of a fixing device mounted on an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer; Pressing member of a fixing device mounted on an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer Used as a heat transfer part for heat flow control on which the treatment object of the membrane control device is placed; Used for a heat transfer part for heat flow control on which the treatment object of the film control device is placed; and the outer layer of the radioactive substance storage container It is used between interiors; it is used in a box body provided with a solar panel that absorbs sunlight; it is used between a reflective sheet of a CCFL backlight and an aluminum chassis.

  Hereinafter, the present invention will be described in more detail by way of examples. However, the present invention is not limited to the examples. The “parts” and “%” used here are based on mass unless otherwise specified.

<Appearance>
After producing the heat conductive pressure-sensitive-adhesive sheet-like molded body as described later, the appearance was visually evaluated. The results are shown in Tables 2 and 3. In the results shown in Tables 2 and 3, “good” means that no appearance defects such as pinholes and cracks have occurred, and “pinpole” means that pinpoles have occurred (holes). Means that there was.

<Sheet shape maintenance>
When producing a heat conductive pressure-sensitive adhesive sheet-like molded product as described later, it was evaluated whether or not the release PET film was peeled off while maintaining the shape of the heat conductive pressure-sensitive adhesive sheet-like molded product. . The results are shown in Tables 2 and 3. In the results shown in Table 2 and Table 3, “◯” means that the release PET film was peeled off while maintaining the sheet shape of the thermally conductive pressure-sensitive adhesive sheet-like molded product, and “×” Means that the release PET film could not be peeled off while maintaining the sheet shape of the heat conductive pressure-sensitive adhesive sheet-like molded product.

<Sheet cutting ability>
In the evaluation of <Sheet shape maintainability> above, another one on the side opposite to the release PET film peeled off during the evaluation of <Sheet shape maintainability> The elongation of the thermally conductive pressure-sensitive adhesive sheet-like molded product and the presence or absence of tearing when the thermally conductive pressure-sensitive adhesive sheet-like molded product was peeled from two release PET films were evaluated. The results are shown in Tables 2 and 3. In the results shown in Table 2 and Table 3, “◎” means that the thermally conductive pressure-sensitive adhesive sheet-like molded body was peeled off from the release PET film without substantially extending, and “◯” Means that the heat-conductive pressure-sensitive adhesive sheet-like molded body was somewhat stretched, but was peeled off from the release PET film, and “x” means that the heat-conductive pressure-sensitive adhesive sheet-like molded body was a sheet It means that the shape has been broken.

<Hardness (flexibility)>
After producing a heat conductive pressure-sensitive adhesive sheet-like molded body as will be described later, a plurality of test pieces were prepared by cutting it into a size of 30 mm × 50 mm. The release PET film was peeled off from these test pieces, and the surface from which the release PET film was peeled was pulverized using talc. Test pieces were laminated so that the thickness was about 12 mm, and placed on a sample table of a hardness meter (trade name “CL-150”, manufactured by Kobunshi Keiki Co., Ltd., JIS K7312). Thereafter, the damper was dropped and the hardness was measured. A value 20 seconds after the damper contacted the sample was read as a measured value. The measurement was performed in a 23 ° C. atmosphere. The results are shown in Tables 2 and 3. The hardness is good if it is 35 or less.

<Preparation of heat conductive pressure-sensitive adhesive sheet-like molded body>
Example 1
A reactor was charged with 100 parts of a monomer mixture composed of 94% 2-ethylhexyl acrylate and 6% acrylic acid, 0.03 parts 2,2′-azobisisobutyronitrile and 700 parts ethyl acetate. Then, after substitution with nitrogen, a polymerization reaction was carried out at 80 ° C. for 6 hours. The polymerization conversion rate was 97%. The obtained polymer was dried under reduced pressure to evaporate ethyl acetate to obtain a viscous solid (meth) acrylic acid ester polymer (A1-1). The weight average molecular weight (Mw) of the (meth) acrylic acid ester polymer (A1-1) was 270,000, and the weight average molecular weight (Mw) / number average molecular weight (Mn) was 3.1. The weight average molecular weight (Mw) and the number average molecular weight (Mn) were determined in terms of standard polystyrene by gel permeation chromatography using tetrahydrofuran as an eluent.

  Next, 79.0 parts of 2-ethylhexyl acrylate (2EHA) and an organic peroxide thermal polymerization initiator (1,6-bis (t-butylperoxycarbonyloxy) hexane (1 minute half-life temperature is 150 ° C. )) A polyfunctional monomer (light acrylate PE) which is a cross-linking agent in which 1.0 part is mixed with pentaerythritol triacrylate, pentaerythritol tetraacrylate and pentaerythritol diacrylate in a ratio of 60: 35: 5. -3A, manufactured by Kyoeisha Chemical Co., Ltd.) was measured with an electronic balance, and these were mixed with 20 parts of the (meth) acrylic acid ester polymer (A1-1). For the mixing, a thermostatic bath (manufactured by Toki Sangyo Co., Ltd., trade name “Viscomate 150III”) and Hobart mixer (manufactured by Kodaira Seisakusho, trade name “ACM-5LVT type”, capacity: 5 L) were used. The temperature control of the Hobart container was set to 40 ° C., the rotation speed scale was set to 3, and the mixture was stirred for 10 minutes. This process is referred to as a first mixing process.

Next, 5.0 parts of tackifier (C) (trade name “KE-359” manufactured by Arakawa Chemical Industries, Ltd., ultra-light rosin ester) and polyglycerin condensed ricinoleic acid ester (solar) as dispersant (D) Made by Kagaku Co., Ltd., trade name “Tirabazole H-818”, liquid at 20 ° C., 5.0 parts number average molecular weight 4,000, phosphate ester (Ajinomoto Fine Techno Co., Ltd., trade name “Leophos 65”, 50 parts of the compound name “triaryl isopropylate” and aluminum hydroxide (trade name “BF-083” manufactured by Nippon Light Metal Co., Ltd.) as the heat conductive filler (B), average particle diameter: 8 μm, BET ratio 800 parts of surface area: 0.8 m ² / g) are weighed and put into the Hobart container, the temperature control of the Hobart container is set to 40 ° C., the rotation speed scale is set to 5, and the mixture is stirred for 10 minutes. Stir. This process is referred to as a second mixing process.

  Next, the mixed composition obtained through the first mixing step and the second mixing step is hung on a release PET film having a thickness of 75 μm, and another release agent having a thickness of 75 μm is further applied on the mixed composition. Covered with PET film. This laminate in which the mixed composition was sandwiched between the release PET films was passed between two rolls adjusted to a distance of 650 μm to form the mixed composition into a sheet. Thereafter, the laminate was put into an oven and heated at 150 ° C. for 15 minutes. By this heating step, the (meth) acrylic acid ester monomer and the polyfunctional monomer are polymerized, and at the same time, the (meth) acrylic acid ester polymer (A1-1) and (meth) are cross-linked by the crosslinking agent. A polymer containing a structural unit derived from an acrylate monomer was crosslinked to obtain a heat conductive pressure-sensitive adhesive sheet-like molded body (hereinafter simply referred to as “sheet”) (G1). In addition, it was 99.9% when the polymerization conversion rate of the (meth) acrylic acid ester monomer was computed from the amount of residual monomers in a sheet | seat (G1).

(Examples 2 to 10 and Comparative Example 1)
The sheets (G2 to G10) according to Examples 2 to 10 and the sheet (GC1) according to Comparative Example 1 in the same manner as in Example 1 except that the composition of each substance was changed as shown in Table 2 and Table 3. Was made. In Example 8, alumina (made by Showa Denko KK, trade name “AL-47-H”, average particle diameter: 1.1 μm, BET specific surface area: 2 m as the heat conductive filler (B) in the second mixing step. ² / g) was also used.

As shown in Table 2 and Table 3, the sheets (G1 to G10) according to the examples all have good appearance even when a large amount of thermally conductive filler (aluminum hydroxide, alumina) is added, The sheet shape maintainability and sheet tearability were good, and the hardness was low (flexibility was high).
On the other hand, the sheet (GC1) according to Comparative Example 1 that did not use a tackifier and a dispersant had pinholes, was inferior in sheet tearing properties, and had high hardness.

DESCRIPTION OF SYMBOLS 1 Board | substrate 2,12a, 12b, 22 Heat generating body 3,13 Heat radiating body 4,14,24 Thermal conductive pressure-sensitive-adhesive sheet-like molded object

Claims (5)

100 parts by weight of (meth) acrylic resin composition (A) containing (meth) acrylic acid ester polymer (A1) and (meth) acrylic acid ester monomer (α1);
200 to 1500 parts by mass of the thermally conductive filler (B),
0.5 to 30 parts by mass of tackifier (C),
1 to 30 parts by mass of the dispersant (D),
In the mixed composition in which the dispersant (D) is a fatty acid ester of a polyhydric alcohol polymer, at least a polymerization reaction of the (meth) acrylic acid ester monomer (α1) is performed, and heat conductive pressure sensitive Adhesive composition (F). 100 parts by weight of (meth) acrylic resin composition (A) containing (meth) acrylic acid ester polymer (A1) and (meth) acrylic acid ester monomer (α1);
200 to 1500 parts by mass of the thermally conductive filler (B),
0.5 to 30 parts by mass of tackifier (C),
1 to 30 parts by mass of the dispersant (D),
After forming the mixed composition in which the dispersant (D) is a fatty acid ester of a polyhydric alcohol polymer into a sheet shape, or while forming the mixed composition into a sheet shape, at least the (meth) acrylic acid ester unit. Thermally conductive pressure-sensitive adhesive sheet-like molded product (G) obtained by polymerization reaction of the monomer (α1). 100 parts by weight of (meth) acrylic resin composition (A) containing (meth) acrylic acid ester polymer (A1) and (meth) acrylic acid ester monomer (α1);
200 to 1500 parts by mass of the thermally conductive filler (B),
0.5 to 30 parts by mass of tackifier (C),
1 to 30 parts by mass of the dispersant (D),
Producing a mixed composition in which the dispersant (D) is a fatty acid ester of a polyhydric alcohol polymer; and
A step of performing a polymerization reaction of at least the (meth) acrylic acid ester monomer (α1) in the mixed composition;
The manufacturing method of a heat conductive pressure sensitive adhesive composition (F) containing this. 100 parts by weight of (meth) acrylic resin composition (A) containing (meth) acrylic acid ester polymer (A1) and (meth) acrylic acid ester monomer (α1);
200 to 1500 parts by mass of the thermally conductive filler (B),
0.5 to 30 parts by mass of tackifier (C),
1 to 30 parts by mass of the dispersant (D),
Producing a mixed composition in which the dispersant (D) is a fatty acid ester of a polyhydric alcohol polymer; and
A step of performing a polymerization reaction of at least the (meth) acrylic acid ester monomer (α1) after forming the mixed composition into a sheet or while forming the mixed composition into a sheet;
The manufacturing method of a heat conductive pressure-sensitive-adhesive sheet-like molded object (G) including this.   The heat conductive pressure-sensitive adhesive composition (F) according to claim 1 bonded to the heating element and the heating element, or the heat conduction according to claim 2 bonded to the heating element and the heating element. Electronic device comprising a pressure-sensitive adhesive sheet-like molded body (G).

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