JP2013095779A - Heat-conductive pressure-sensitive adhesive composition, heat-conductive pressure-sensitive adhesive sheet-like molded body, production method 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-like molded body which are reworkable immediately after sticking, and whose adhesion increases after sticking in the lapse of time, and to provide the production method thereof, and an electronic apparatus including the heat-conductive pressure-sensitive adhesive composition or the heat-conductive pressure-sensitive adhesive sheet-like molded body.SOLUTION: In a mixture composition which includes: 100 pts.mass of a (meth)acrylic resin composition (A) including a (meth)acrylate polymer (A1) and a (meth)acrylate monomer (α1); 200 to 1,200 pts.mass of a heat-conductive filler (B); and 3 to 25 pts.mass of a plasticizer (D), and of which the plasticizer (D) is an epoxy group- containing (meth)acrylate polymer, the mixture composition is formed by performing a polymerization reaction of the (meth)acrylate monomer (α1) and a crosslinking reaction of a polymer including a structural unit derived from the (meth)acrylate polymer (A1) and/or the (meth)acrylate monomer (α1).

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-like molding. The present invention relates to an electronic device having a body.

  2. Description of the Related Art In recent years, the amount of heat generated by electronic components provided in electronic devices such as a plasma display panel (PDP) and an integrated circuit (IC) chip has increased as the 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.

  Since the heat conductive pressure-sensitive adhesive composition and the heat conductive pressure-sensitive adhesive sheet-like molded body are mainly used to transmit heat from the heating element to the heat radiating body, it is preferable that the heat conductivity is high. Known fillers that can improve thermal conductivity include, for example, zinc oxide (Patent Documents 1 to 3) and graphite.

JP 2008-163145 A JP 2008-127482 A JP 2008-127481 A

  When fixing a heat generating body and a thermal radiation body with a heat conductive pressure sensitive adhesive composition or a heat conductive pressure sensitive adhesive sheet-like molded object, it is preferable that both can be fixed firmly. On the other hand, from the viewpoint of productivity and the like, it can be re-applied (hereinafter sometimes referred to as “rework”) immediately after the heat-conductive pressure-sensitive adhesive composition or the heat-conductive pressure-sensitive adhesive sheet-like molded product is applied. It is preferable that However, in the sheets described in Patent Documents 1 to 3, such tackiness has not been studied. In particular, rework has not been sufficiently studied.

  Therefore, the present invention is a heat conductive pressure-sensitive adhesive composition and a heat conductive pressure-sensitive adhesive sheet-like molded article that can be reworked immediately after sticking, and become sticky with time after sticking, and these It is an object of the present invention to provide a manufacturing method and an electronic device including the thermally conductive pressure-sensitive adhesive composition or the thermally conductive pressure-sensitive adhesive sheet-like molded body.

  In the first aspect of the present invention, 100 mass of (meth) acrylic resin composition (A) containing (meth) acrylic acid ester polymer (A1) and (meth) acrylic acid ester monomer (α1). Parts, 200 parts by mass or more and 1200 parts by mass or less of the thermally conductive filler (B), and 3 parts by mass or more and 25 parts by mass or less of the plasticizer (D), and the plasticizer (D) contains an epoxy group ( In the mixed composition which is a meth) acrylic acid ester polymer, the polymerization reaction of the (meth) acrylic acid ester monomer (α1) and the (meth) acrylic acid ester polymer (A1) and / or (meth) acrylic It is a heat conductive pressure-sensitive adhesive composition (F) in which a crosslinking reaction of a polymer containing a structural unit derived from an acid ester monomer (α1) is performed.

  In this specification, “(meth) acryl” means “acryl and / or methacryl”. “Thermal conductive filler (B)” 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. Means a filler having a thermal conductivity of 1 W / m · K or more. The “polymerization reaction of (meth) acrylate monomer (α1)” means a polymerization reaction for obtaining a polymer that generates a structural unit derived from the (meth) acrylate monomer (α1). "(Meth) acrylic acid ester polymer (A1) and / or (meth) acrylic acid ester monomer (α1) -derived polymer cross-linking reaction" means (meth) acrylic acid ester polymer Cross-linking reaction between (A1), cross-linking reaction between polymers containing structural units derived from (meth) acrylic acid ester monomer (α1), and (meth) acrylic acid ester polymers (A1) and (meth) Among crosslinking reactions with a polymer containing a structural unit derived from an acrylate monomer (α1), it means one or more crosslinking reactions.

  In the second aspect of the present invention, 100 mass of (meth) acrylic resin composition (A) containing (meth) acrylic acid ester polymer (A1) and (meth) acrylic acid ester monomer (α1). Parts, 200 parts by mass or more and 1200 parts by mass or less of the thermally conductive filler (B), and 3 parts by mass or more and 25 parts by mass or less of the plasticizer (D), and the plasticizer (D) contains an epoxy group ( A polymerization reaction of the (meth) acrylic acid ester monomer (α1), after molding the mixed composition which is a meth) acrylic acid ester polymer into a sheet shape, or while molding the mixed composition into a sheet shape, Thermally conductive pressure-sensitive adhesive, wherein a (meth) acrylate polymer (A1) and / or a polymer containing a structural unit derived from a (meth) acrylate monomer (α1) is crosslinked. It is a sheet-like molded object (G).

  In the third aspect of the present invention, 100 mass of (meth) acrylic resin composition (A) containing (meth) acrylic acid ester polymer (A1) and (meth) acrylic acid ester monomer (α1). Parts, 200 parts by mass or more and 1200 parts by mass or less of the thermally conductive filler (B), and 3 parts by mass or more and 25 parts by mass or less of the plasticizer (D), and the plasticizer (D) contains an epoxy group ( A step of preparing a mixed composition which is a (meth) acrylic acid ester polymer, and a polymerization reaction of the (meth) acrylic acid ester monomer (α1) in the mixed composition, and (meth) acrylic acid ester weight A thermally conductive pressure-sensitive adhesive composition (F) comprising a step of performing a crosslinking reaction of a polymer containing a structural unit derived from the coalescence (A1) and / or the (meth) acrylic acid ester monomer (α1). It is a manufacturing method.

  The 4th aspect of this invention is 100 masses of (meth) acrylic-ester resin compositions (A) containing the (meth) acrylic-ester polymer (A1) and the (meth) acrylic-ester monomer ((alpha) 1). Parts, 200 parts by mass or more and 1200 parts by mass or less of the thermally conductive filler (B), and 3 parts by mass or more and 25 parts by mass or less of the plasticizer (D), and the plasticizer (D) contains an epoxy group ( (Meth) acrylic acid, a step of preparing a mixed composition which is a (meth) acrylic ester polymer, and after forming the mixed composition into a sheet or while forming the mixed composition into a sheet A polymerization reaction of the ester monomer (α1) and a crosslinking reaction of a polymer containing a structural unit derived from the (meth) acrylic acid ester polymer (A1) and / or the (meth) acrylic acid ester monomer (α1) A step of performing, including heat conduction A method for producing a pressure-sensitive adhesive sheet materials (G).

  The fifth aspect of the present invention is a heat radiator and the heat conductive pressure-sensitive adhesive composition (F) of the first aspect of the present invention attached to the heat radiator, or the heat radiator and the heat radiator. In addition, there is provided an electronic device including the heat conductive pressure-sensitive adhesive sheet-like molded body (G) according to the second aspect of the present invention.

  According to the present invention, a heat conductive pressure-sensitive adhesive composition and a heat conductive pressure-sensitive adhesive sheet-like molded article that can be reworked immediately after sticking, and become sticky with time after sticking, and these A manufacturing method and an electronic device provided with the heat conductive pressure-sensitive adhesive composition or the heat conductive pressure-sensitive adhesive sheet-like molded body can be provided.

1. Thermally conductive pressure-sensitive adhesive composition (F), thermally conductive pressure-sensitive adhesive sheet-like molded body (G)
The thermally conductive pressure-sensitive adhesive composition (F) of the present invention comprises a (meth) acrylic resin composition containing a (meth) acrylic acid ester polymer (A1) and a (meth) acrylic acid ester monomer (α1). Polymer that produces structural units derived from (meth) acrylate monomer (α1) in a mixed composition containing product (A), thermally conductive filler (B), and plasticizer (D) And a crosslinking reaction between (meth) acrylic acid ester polymers (A1), a crosslinking reaction between polymers containing a structural unit derived from a (meth) acrylic acid ester monomer (α1), and A crosslinking reaction of at least one of the crosslinking reaction of the (meth) acrylate polymer (A1) and the polymer containing a structural unit derived from the (meth) acrylate monomer (α1). It is.

  Moreover, the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) of this invention is (meth) acrylic acid after shape | molding the said mixed composition in a sheet form, or shape | molding the said mixed composition in a sheet form. Polymerization reaction for obtaining a polymer that produces a structural unit derived from an ester monomer (α1), a crosslinking reaction between (meth) acrylic acid ester polymers (A1), (meth) acrylic acid ester monomer (α1) Crosslinking reaction between polymers containing structural units derived from, and crosslinking with a polymer containing structural units derived from (meth) acrylic acid ester polymer (A1) and (meth) acrylic acid ester monomer (α1) Any cross-linking reaction among the reactions is performed at least.

  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). In addition, as mentioned above, when obtaining a heat conductive pressure-sensitive-adhesive composition (F) and a heat conductive pressure-sensitive-adhesive sheet-like molded object (G), (meth) acrylic acid ester monomer ((alpha) 1) origin Polymerization reaction to obtain a polymer that yields a structural unit of the above, and a crosslinking reaction of a polymer containing a structural unit derived from the (meth) acrylic acid ester polymer (A1) and / or the (meth) acrylic acid ester monomer (α1) And done. By performing the polymerization reaction and the crosslinking reaction, the polymer containing the structural unit derived from the (meth) acrylic acid ester monomer (α1) is mixed with the component of the (meth) acrylic acid ester polymer (A1) and / or. Join some.

  In this invention, the usage-amount of an acrylic ester polymer (A1) and the (meth) acrylic ester monomer ((alpha) 1) is (meth) with respect to 100 mass% of (meth) acrylic resin compositions (A). The acrylate polymer (A1) is preferably 5% by mass or more and 40% by mass or less, and the (meth) acrylic acid ester monomer (α1) is preferably 60% by mass or more and 95% 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. 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 the (meth) acrylic acid ester monomer that forms a homopolymer having a glass transition temperature of −20 ° C. or lower. It is preferable to contain the unit (a1) and the monomer unit (a2) having an organic acid group.

  The (meth) acrylate monomer (a1m) that gives the unit (a1) of the (meth) acrylate monomer 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 (- 5 ° 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% by mass or more and 99.5% by 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 a monomer having acrylic acid or methacrylic acid is particularly preferable. . 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 above-mentioned 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 is in the range of 100,000 to 1,000,000 in terms of standard polystyrene. It is more preferable that it is in the range of 200,000 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 mixture (α1))
The (meth) acrylate monomer (α1) is not particularly limited as long as it contains a (meth) acrylate monomer, but a homopolymer having a glass transition temperature of −20 ° C. or lower is molded. It is preferable to contain the (meth) acrylic acid ester monomer (a5m).

  As an example of the (meth) acrylic acid ester monomer (a5m) for molding 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) may be a mixture of a (meth) acrylic acid ester monomer (a5m) and a monomer copolymerizable therewith.

  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, and can be copolymerized therewith. It is good also as a mixture of the monomer (a6m) which has an 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 with the monomer (a7m) which can be copolymerized 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.

<Polymerization initiator>
When obtaining the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded product (G), the (meth) acrylic acid ester monomer (α1) and a polyfunctional monomer described below are used. The body polymerizes. In order to accelerate the polymerization, 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. From the viewpoint of imparting excellent adhesiveness to the obtained heat conductive pressure-sensitive adhesive composition (F) and heat conductive pressure-sensitive adhesive sheet-like molded body (G), an organic peroxide thermal polymerization initiator is used. It is preferable to use it.

  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 rate of (meth) acrylic acid ester monomer mixture ((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 product (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, the progress of polymerization reaction is induced excessively by adding a polymerization initiator, As a result, a heat conductive pressure-sensitive-adhesive sheet-like molded object (G) However, it does not become a smooth sheet, and it is easy to prevent a situation in which material destruction occurs.

<Multifunctional monomer>
It is preferable to use a polyfunctional monomer in the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded product (G) of the present invention. As the polyfunctional monomer, one that can be copolymerized with the monomer contained in the (meth) acrylic acid ester monomer (α1) is used. Moreover, it is preferable that the polyfunctional monomer has a plurality of polymerizable unsaturated bonds, and has the unsaturated bond at the terminal. By using such a polyfunctional monomer, intramolecular and / or intermolecular crosslinking is introduced into the copolymer, and the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet are introduced. The cohesive force as a pressure-sensitive adhesive of the shaped molded body (G) can be increased.

  Usually, at the time of polymerization such as radical thermal polymerization, a certain degree of crosslinking reaction proceeds without using a polyfunctional monomer. However, it is preferable to use a polyfunctional monomer in order to form a desired amount of a crosslinked structure more reliably.

  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 in the heat conductive pressure-sensitive adhesive composition (F) or the heat conductive pressure-sensitive adhesive sheet-like molded body (G) is 100 mass of the (meth) acrylic resin composition (A). It is preferably 0.1 parts by weight or more and 15 parts by weight or less, more preferably 0.2 parts by weight or more and 8 parts by weight or less, and further preferably 0.5 parts by weight or more and 2 parts by weight or less. preferable. By setting the amount of the polyfunctional monomer used in the above range, the heat conductive pressure sensitive adhesive composition (F) and the heat conductive pressure sensitive adhesive sheet-like molded body (G) are suitable as a pressure sensitive adhesive. It becomes easy to give a strong cohesive force.

<Thermal conductive filler (B)>
A heat conductive filler (B) is used for the heat conductive pressure sensitive adhesive composition (F) and the heat conductive pressure sensitive adhesive sheet-like molded body (G) of the present invention. When the heat conductive filler (B) is not added, the heat conductivity of the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) described later is not added. The filler is not particularly limited as long as the filler has a thermal conductivity of 1 W / m · K or more.

  A well-known heat conductive filler can be used for a heat conductive filler (B). Specific examples of the thermally conductive filler (B) include aluminum hydroxide, gallium hydroxide, indium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, zinc borate hydrate, kaolin clay. Calcium aluminate hydrate, calcium carbonate, aluminum carbonate, dawsonite, aluminum oxide (alumina), magnesium oxide, zinc oxide, boron nitride, aluminum nitride, silica and the like. Among these, calcium carbonate, aluminum hydroxide, and aluminum oxide are preferable because they are easily available, chemically stable, and can be blended in a large amount. One kind of the heat conductive filler (B) may be used alone, or two or more kinds may be used in combination.

  Moreover, it is preferable that the average particle diameter of the heat conductive filler (B) used for this invention is 0.1 micrometer or more and 50 micrometers or less. In the present invention, the “average particle diameter” means that measured by the method described below. That is, a laser type particle size measuring machine (manufactured by Seishin Enterprise Co., Ltd.) is used, and measurement is performed by a microsorting control method (a method in which the measurement target particles are allowed to pass only in the measurement region and the measurement reliability is improved). According to this measurement method, the measurement target particles 0.01 g to 0.02 g are caused to flow through the cell, so that the measurement target particles flowing in the measurement region are irradiated with the semiconductor laser light having a wavelength of 670 nm. By measuring the scattering and diffraction of laser light with a measuring instrument, the average particle size and particle size distribution are calculated from the diffraction principle of Franhofer.

Further, BET specific surface area of the thermally conductive filler (B) is preferably, 1.0 m ² / g or more 5.0 m ² / g or less or less 1.0 m ² / g or more ^{10 m} 2 / g Is more preferably 1.0 m ² / g or more and 3.0 m ² / g or less. By setting the BET specific surface area of the heat conductive filler (B) within the above range, a mixed composition serving as a base for the heat conductive pressure sensitive adhesive composition (F) and the heat conductive pressure sensitive adhesive sheet-like molded body (G). It can suppress that the viscosity of a thing increases excessively. However, as the heat conductive filler (B), a heat conductive filler (B1) having a BET specific surface area in the above range, a heat conductive filler (B2) having a BET specific surface area of less than 1.0 m ² / g, and May be used in combination. By using the thermally conductive filler (B) having a different BET specific surface area in this way, a large amount of the thermally conductive filler (B) is contained in the mixed composition while suppressing an excessive increase in viscosity of the mixed composition. It becomes possible to mix | blend with. In the present invention, “BET specific surface area” means that measured by the following method. First, a mixed gas of nitrogen and helium is introduced into a BET specific surface area measuring apparatus, and a sample cell containing a sample (an object to be measured for BET specific surface area) is immersed in liquid nitrogen to adsorb nitrogen gas to the sample surface. After reaching adsorption equilibrium, the sample cell is placed in a water bath and warmed to room temperature, and nitrogen adhering to the sample is desorbed. Since the mixing ratio of the gas before and after passing through the sample cell changes during the adsorption and desorption of nitrogen gas, this change is detected by a thermal conductivity detector (TCD) using a gas with a constant mixing ratio of nitrogen and helium as a control. Then, the adsorption amount and desorption amount of nitrogen gas are obtained. Before the measurement, a unit amount of nitrogen gas is introduced into the apparatus for calibration, and the surface area value corresponding to the value detected by TCD is obtained to obtain the surface area of the sample. Further, the BET specific surface area can be obtained by dividing the surface area by the mass of the sample.

  The amount of the heat conductive filler (B) used in the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) is (meth) acrylic resin composition (A) 100. It is 200 mass parts or more and 1200 mass parts or less with respect to a mass part, It is preferable that they are 300 mass parts or more and 1000 mass parts or less, It is more preferable that they are 400 mass parts or more and 900 mass parts or less. When the content of the heat conductive filler (B) exceeds the above range, the heat conductive pressure sensitive adhesive composition (F) and the mixed composition serving as a base of the heat conductive pressure sensitive adhesive sheet-like molded body (G) Even if the viscosity increases excessively, it becomes difficult to mold the heat conductive pressure-sensitive adhesive composition (E) and the heat conductive pressure-sensitive adhesive sheet-like molded body (F), or even if it can be molded, the heat conductive pressure-sensitive adhesive There is a possibility that the hardness of the composition (F) and 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, when the content of the heat conductive filler (B) is less than the above range, the heat conductive pressure sensitive adhesive composition (F) and the heat conductive pressure sensitive adhesive sheet are used by using the heat conductive filler (B). There is a possibility that the effect of improving the thermal conductivity of the shaped molded body (G) is insufficient.

<Plasticizer (D)>
A plasticizer (D) is used for the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) of the present invention. In the present invention, an epoxy group-containing (meth) acrylic acid ester polymer is used as the plasticizer (D). If the resin used as the plasticizer (D) is not a (meth) acrylic resin or has no epoxy group, the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded product This is because it may be difficult to mold (G), or even if it can be molded, sufficient tackiness may not be imparted.

  Moreover, it is preferable that the weight average molecular weight (Mw) of a plasticizer (D) is in the range of 1000 or more and 5000 or less in standard polystyrene conversion, as measured by gel permeation chromatography (GPC method). When the molecular weight is too low, it functions only as a cross-linking agent, and the adhesive force of the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded product (G) cannot be sufficiently improved. It is possible. On the other hand, in the present invention, the plasticizer (D) is preferably a liquid, but becomes solid when the molecular weight is too high.

  By using such a plasticizer (D) together with the (meth) acrylic resin composition (A) or the like, the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G ) Can be easily reworked immediately after sticking, and the adhesive strength can be strengthened as time passes after sticking. The reason for this is not clear, but can be considered as follows. That is, since the plasticizer (D) is movable in the heat conductive pressure-sensitive adhesive sheet-like molded body (G), the time elapses after the heat conductive pressure-sensitive adhesive sheet-like molded body (G) is pasted. When the plasticizer (D) moves to the interface between the adherend and the heat conductive pressure-sensitive adhesive sheet-like molded body (G), the adhesive force of the heat conductive pressure-sensitive adhesive sheet-like molded body (G) is improved. Conceivable. That is, immediately after sticking, there are few plasticizers (D) located at the interface with the adherend, and since sufficient adhesive force is not exhibited, it can be reworked. It is considered that the plasticizer (D) located at the interface increases and can exhibit sufficient adhesive force. The same applies to the heat conductive pressure sensitive adhesive composition (F).

  Specific examples of the plasticizer (D) used in the present invention include “ARUFON UG-4000” (“ARUFON” is a registered trademark) manufactured by Toa Gosei Co., Ltd., and the like.

  The amount of the plasticizer (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). 100 parts by mass, 3 parts by mass to 25 parts by mass, preferably 4 parts by mass to 22 parts by mass, and more preferably 4 parts by mass to 20 parts by mass. By making content of a plasticizer (D) into the said range, as mentioned above, the adhesive force of a heat conductive pressure-sensitive-adhesive composition (F) and a heat conductive pressure-sensitive-adhesive sheet-like molded object (G) is made. Can be adjusted. On the other hand, if the content of the plasticizer (D) is too small, the adhesive strength of the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G) becomes insufficient, and the plasticizer ( If there is too much content of D), there exists a possibility that a heat conductive pressure sensitive adhesive composition (F) and a heat conductive pressure sensitive adhesive sheet-like molded object (G) cannot be shape | molded.

<Phosphate ester (C)>
It is preferable to use phosphate ester (C) 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 phosphoric ester (C), it becomes easy to give the flame retardance which was excellent in the heat conductive pressure sensitive adhesive composition (F) and the heat conductive pressure sensitive adhesive sheet-like molded object (G). Further, when a large amount of the phosphate ester (C) is used, it becomes difficult to form the heat conductive pressure-sensitive adhesive composition (F) and the heat conductive pressure-sensitive adhesive sheet-like molded body (G). By using the ester (C) and the thermal conductive filler (B1) in combination, the thermal conductive pressure-sensitive adhesive composition (F) and the thermal conductive pressure-sensitive adhesive property can be used even if the amount of the phosphate ester (C) is suppressed. The flame retardancy of the sheet-like molded body (G) can be improved, and the moldability is easily improved.

  The phosphate ester (C) preferably has a viscosity at 25 ° C. of 3000 mPa · s or more. By making the viscosity of the phosphoric ester (C) within the above range, it is prevented that the moldability of the heat conductive pressure-sensitive adhesive composition (F) or the heat conductive pressure-sensitive adhesive sheet-like molded body (G) is deteriorated. It becomes easy to do. 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 phosphate ester (C) is always a liquid in the temperature range of 15 to 100 ° C. under atmospheric pressure. If the phosphate ester (C) is liquid when mixed, the workability is good and the heat conductive pressure-sensitive adhesive composition (F) or the heat conductive pressure-sensitive adhesive sheet-like molded body (G) is formed. It becomes easy. When molding the heat conductive pressure-sensitive adhesive composition (F) or the heat conductive pressure-sensitive adhesive sheet-like molded product (G) containing the phosphoric ester (C), heat is applied in an environment of 15 ° C. or higher and 100 ° C. or lower. It is preferable to mix each substance which comprises a conductive pressure sensitive 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, both a condensed phosphate ester and a non-condensed phosphate ester can be used as the phosphate ester (C). 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 the phosphate ester (C) satisfying 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 (C) may be used individually by 1 type, and may use 2 or more types together.

  When the phosphoric ester (C) is used in 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 a (meth) acrylic resin composition. The amount of the product (A) is 100 parts by mass, preferably 45 parts by mass or more and 190 parts by mass or less, more preferably 55 parts by mass or more and 150 parts by mass or less, and 70 parts by mass or more and 120 parts by mass or less. Is more preferable. By making content of phosphate ester (C) into the said range, it is easy to improve the flame retardance of a heat conductive pressure sensitive adhesive composition (F) or a heat conductive pressure sensitive adhesive sheet-like molded object (G). Become.

<Other additives>
In addition to the above-described substances, the above-described effects due to the addition of the above-described substances are hindered 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. Various known additives can be added within the range. 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 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 The thermally conductive pressure-sensitive adhesive composition (F) of the present invention is prepared by mixing the substances described above, followed by the polymerization reaction of the (meth) acrylic acid ester monomer (α1) and (meth) acrylic. It can obtain by performing the crosslinking reaction of the polymer containing the structural unit derived from the acid ester polymer (A1) and / or the (meth) acrylic acid ester monomer (α1).

  That is, the manufacturing method of the heat conductive pressure-sensitive-adhesive composition (F) of this invention contains the (meth) acrylic acid ester polymer (A1) and the (meth) acrylic acid ester monomer ((alpha) 1) ( A (meth) acrylic resin composition (A), a thermally conductive filler (B), a phosphate ester (C), and a plasticizer (D), and the plasticizer (D) contains an epoxy group (meth) A step of producing a mixed composition which is an acrylic ester polymer, and in the mixed composition, a polymerization reaction of the (meth) acrylic ester monomer (α1) and a (meth) acrylic ester polymer ( A1) and / or a step of performing a crosslinking reaction of a polymer containing a structural unit derived from 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.

  In the manufacturing method of the heat conductive pressure sensitive adhesive composition (F) of this invention, when performing the said superposition | polymerization and crosslinking reaction, it is preferable to heat. 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) acrylic acid ester monomer (α1) and the polyfunctional monomer proceeds. Although a temperature range changes with kinds of polymerization initiator to be used, 100 to 200 degreeC is preferable and 130 to 180 degreeC is more preferable.

  The heat conductive pressure-sensitive adhesive sheet-like molded product (G) of the present invention is prepared by mixing the substances described so far into a sheet shape, or while forming into a sheet shape, with a single (meth) acrylate ester. The polymerization reaction of the monomer (α1) and the crosslinking reaction of the polymer containing a structural unit derived from the (meth) acrylic acid ester polymer (A1) and / or the (meth) acrylic acid ester monomer (α1) are performed. Can be obtained.

  That is, the manufacturing method of the heat conductive pressure-sensitive-adhesive composition (F) of this invention contains the (meth) acrylic acid ester polymer (A1) and the (meth) acrylic acid ester monomer ((alpha) 1) ( A (meth) acrylic resin composition (A), a thermally conductive filler (B), a phosphate ester (C), and a plasticizer (D), and the plasticizer (D) contains an epoxy group (meth) The step of preparing a mixed composition which is an acrylate polymer, and after forming the mixed composition into a sheet or while forming the mixed composition into a sheet, The polymerization reaction of the monomer (α1) and the crosslinking reaction of the polymer containing a structural unit derived from the (meth) acrylic acid ester polymer (A1) and / or the (meth) acrylic acid ester monomer (α1) are performed. It includes a process. 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 manufacturing method of the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) of this invention, when performing the said superposition | polymerization and crosslinking reaction, it is preferable to heat. 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) acrylic acid ester monomer (α1) and the polyfunctional monomer proceeds. Although a temperature range changes with kinds of polymerization initiator to be used, 100 to 200 degreeC is preferable and 130 to 180 degreeC is more preferable.

  The method for molding the mixed composition into a sheet is not particularly limited. As a suitable method, for example, a method of forming a sheet by applying the mixed composition on a process paper such as a polyester film subjected to a release treatment, and if necessary, the mixed composition between two release process papers. A method of forming a sheet by pressing between rolls with an object sandwiched, 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. Is mentioned.

  The thickness of the heat conductive pressure-sensitive adhesive sheet-like molded body (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 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 is easy to prevent entrainment, and as a result, an 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 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 as some electronic components with which an electronic device is equipped. In that case, it can also be directly molded on a base material such as a radiator and provided as a part of the electronic component. 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 crystals, 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.

<Adhesive strength>
The following procedure evaluated the adhesive force immediately after sticking to an aluminum plate, the adhesive force after 6 hours passed, and the improvement rate of adhesive strength. The results are shown in Table 2. First, a test piece was prepared by cutting a thermally conductive pressure-sensitive adhesive sheet-like molded body produced by the method described later into a size of 10 mm × 10 mm. The test piece was attached to an aluminum plate, and a 200 g roller was reciprocated once on the test piece to press the test piece toward the aluminum plate. Next, the test piece is sandwiched with a tensile tester, the average value of the stress when the test piece is peeled off from the aluminum plate is obtained, and the adhesive strength ("initial stage" in Table 2) immediately after applying this to the aluminum plate. did. At this time, the tensile speed was 100 mm / min. In addition, the test piece similar to the above was pressed with a roller in the same manner as described above, and after being attached to an aluminum plate and allowed to stand in an environment of 23 ° C. for 6 hours, an average value of stress was obtained by the same method as described above. The adhesive strength after 6 hours from pasting on the aluminum plate ("6 hours later" in Table 2). Further, the improvement rate was obtained by dividing the adhesive strength after 6 hours from being applied to the aluminum plate by the adhesive strength immediately after being applied to the aluminum plate. The measurement was performed twice and the average value was taken.

<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, 1.0 part of a polyfunctional monomer obtained by mixing pentaerythritol triacrylate, pentaerythritol tetraacrylate and pentaerythritol diacrylate in a ratio of 60: 35: 5, and 88 parts of 2-ethylhexyl acrylate (2EHA) And 1.0 part of an organic peroxide thermal polymerization initiator (1,6-bis (t-butylperoxycarbonyloxy) hexane (1 minute half-life temperature is 150 ° C.)), epoxy group-containing (meta ) 15 parts of acrylic acid ester polymer (Toa Gosei Co., Ltd., ARUFON UG-4000 (“ARUFON” is a registered trademark))) were weighed with an electronic balance, and these were measured with the above (meth) acrylic acid ester polymer (A1- 1) Mixed with 13 parts. 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 60 ° 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, 70 parts of phosphoric acid ester (Ajinomoto Fine Techno Co., Ltd., trade name “Reophos 65”, compound name “triaryl isopropylate”) and aluminum hydroxide (Nihon Light Metal Co., Ltd., trade name “BF”) −083 ”, average particle size: 8 μm, BET specific surface area: 0.8 m ² / g) and alumina (Showa Denko KK, trade name“ AL-47-H ”, average particle size: 2 μm, BET 300 parts of specific surface area: 1.1 m ² / g) were weighed and put into the Hobart container, the temperature control of the Hobart container was set to 60 ° C., the rotation speed scale was set to 5, and the mixture was stirred for 10 minutes. This process is referred to as a second mixing process.

  Next, the mixed composition obtained through the first and second mixing steps is hung on a release PET film having a thickness of 75 μm, and another release PET film having a thickness of 75 μm is further dropped on the mixed composition. Covered. This laminate in which the mixed composition was sandwiched between the release PET films was passed through a roll having a distance of 0.45 mm between them to form 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 was polymerized and crosslinked to obtain a 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 and 3 and Comparative Examples 1 to 5)
The sheets (G2, G3) according to Examples 2 and 3 and the sheets (GC1 to GC5) according to Comparative Examples 1 to 5 are the same as Example 1 except that the composition of each substance is changed as shown in Table 2. ) Was produced. The evaluation results are shown in Table 2. In Comparative Example 3, a non-functional group (meth) acrylate polymer (Toa Gosei Co., Ltd., ARUFON UP-1110 (“ARUFON” is a registered trademark) instead of 15 parts of the epoxy group-containing (meth) acrylate polymer. .)) 10 parts, in Comparative Example 4, the alkoxysilyl group-containing (meth) acrylic acid ester polymer (Toa Gosei Co., Ltd., ARUFON US-6110 (“ ARUFON "is a registered trademark.)) 15 parts, and in Comparative Example 5, 15 parts of epoxy group-containing (meth) acrylic acid ester polymer, adipic acid polyester (ADEKA Corporation) which is generally used as a plasticizer 15 parts manufactured by PN-350) were used.

  As shown in Table 2, the sheets (G1 to G3) according to Examples 1 to 3 each had low adhesive force immediately after application and could be reworked, and exhibited strong adhesive force after 6 hours. . That is, according to the present invention, it was found that a heat conductive pressure-sensitive adhesive sheet-like molded body that can be reworked immediately after sticking and can exhibit strong adhesive strength after a predetermined time has elapsed can be provided. . On the other hand, Comparative Example 2 in which the amount of the epoxy group-containing (meth) acrylic acid ester polymer was large, a non-functional group (meth) acrylic acid ester polymer was used instead of the epoxy group-containing (meth) acrylic acid ester polymer. In Comparative Example 3 and Comparative Example 4 using an adipic acid-based polyester instead of the epoxy group-containing (meth) acrylic acid ester polymer, it was not possible to peel off from the release PET film used at the time of production. In addition, the sheet (GC1) according to Comparative Example 1 in which the amount of the epoxy group-containing (meth) acrylic acid ester polymer is small is slightly weak in adhesive force immediately after application, and is adhesive even after 6 hours have elapsed since application. The strength was weak and the improvement rate of adhesive strength was low. The sheet (GC3) according to Comparative Example 3 using an alkoxysilyl group-containing (meth) acrylate polymer instead of the epoxy group-containing (meth) acrylate polymer has a slightly strong adhesive force immediately after sticking. The adhesive strength after a lapse of time was slightly weak and the improvement rate of the adhesive strength was low.

Claims (5)

100 parts by weight of (meth) acrylic acid ester polymer (A1) and (meth) acrylic resin composition (A1) containing (meth) acrylic acid ester monomer (α1),
200 to 1200 parts by mass of the thermally conductive filler (B),
Including 3 parts by mass or more and 25 parts by mass or less of the plasticizer (D),
In the mixed composition in which the plasticizer (D) is an epoxy group-containing (meth) acrylic acid ester polymer,
The polymerization reaction of the (meth) acrylate monomer (α1) and the structural unit derived from the (meth) acrylate polymer (A1) and / or the (meth) acrylate monomer (α1) A thermally conductive pressure-sensitive adhesive composition (F) obtained by performing a crosslinking reaction of a polymer containing 100 parts by weight of (meth) acrylic acid ester polymer (A1) and (meth) acrylic resin composition (A1) containing (meth) acrylic acid ester monomer (α1),
200 to 1200 parts by mass of the thermally conductive filler (B),
Including 3 parts by mass or more and 25 parts by mass or less of the plasticizer (D),
The (meth) acrylic acid after the plasticizer (D) is an epoxy group-containing (meth) acrylic acid ester polymer mixed composition formed into a sheet or while the mixed composition is formed into a sheet Polymerization reaction of ester monomer (α1) and crosslinking of polymer containing structural unit derived from (meth) acrylic acid ester polymer (A1) and / or (meth) acrylic acid ester monomer (α1) A heat conductive pressure-sensitive adhesive sheet-like molded body (G) obtained by the reaction. 100 parts by weight of (meth) acrylic acid ester polymer (A1) and (meth) acrylic resin composition (A1) containing (meth) acrylic acid ester monomer (α1),
200 to 1200 parts by mass of the thermally conductive filler (B),
Including 3 parts by mass or more and 25 parts by mass or less of the plasticizer (D),
Producing a mixed composition in which the plasticizer (D) is an epoxy group-containing (meth) acrylic acid ester polymer; and
In the mixed composition, the polymerization reaction of the (meth) acrylic acid ester monomer (α1), the (meth) acrylic acid ester polymer (A1) and / or the (meth) acrylic acid ester monomer. A step of performing a crosslinking reaction of a polymer containing a structural unit derived from (α1),
The manufacturing method of a heat conductive pressure sensitive adhesive composition (F) containing this. 100 parts by weight of (meth) acrylic acid ester polymer (A1) and (meth) acrylic resin composition (A1) containing (meth) acrylic acid ester monomer (α1),
200 to 1200 parts by mass of the thermally conductive filler (B),
Including 3 parts by mass or more and 25 parts by mass or less of the plasticizer (D),
A step of producing a mixed composition in which the plasticizer (D) is an epoxy group-containing (meth) acrylic acid ester polymer; and
After forming the mixed composition into a sheet shape, or while forming the mixed composition into a sheet shape, a polymerization reaction of the (meth) acrylic acid ester monomer (α1) and the (meth) acrylic acid A step of performing a crosslinking reaction of the ester polymer (A1) and / or a polymer containing a structural unit derived from the (meth) acrylic acid ester monomer (α1),
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 attached to a heat radiator and the heat radiator, or the heat conductive pressure-sensitive adhesive according to claim 2 attached to the heat radiator and the heat radiator. An electronic apparatus comprising an adhesive sheet-like molded body (G).