JP5975028B2 - Thermally conductive pressure-sensitive adhesive sheet-like molded product, method for producing the same, and electronic device - Google Patents

Description

  The present invention relates to a heat conductive pressure-sensitive adhesive sheet-like molded article, a method for producing the heat conductive pressure-sensitive adhesive sheet-like molded article, and an electronic apparatus provided with the heat conductive pressure-sensitive adhesive sheet-like molded article.

  2. Description of the Related Art In recent years, the amount of heat generated by electronic components such as integrated circuit (IC) chips provided in electronic devices such as plasma display panels and personal computers has increased along with higher performance. As a result, there is a need to take measures 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 generating body to the heat radiating body, various heat conducting sheets are used. In general, in applications for fixing a heating element and a radiator, a sheet having pressure-sensitive adhesiveness in addition to thermal conductivity (hereinafter referred to as “thermally conductive pressure-sensitive adhesive sheet-like molded body”). is necessary.

  The main purpose of the heat conductive pressure-sensitive adhesive sheet-like molded body is to transfer heat from the heat generating body to the heat radiating body. Therefore, it is preferable to increase the heat conductivity. In order to increase the thermal conductivity of a resin composition such as a thermally conductive pressure-sensitive adhesive sheet-like molded article, as described in Patent Documents 1 and 2, a thermally conductive filler such as graphite is used. May be added. Specifically, Patent Document 1 discloses a rubber composition containing artificial graphite having a particle size of 1 to 20 μm. Patent Document 2 discloses a heat conductive rubber composition containing graphite having an average particle size of 10 to 150 μm.

JP-A-5-247268 Japanese Patent Laid-Open No. 2002-3670

  Graphite has high thermal conductivity, and as described above, the thermal conductivity of the resin composition can be increased by adding it to the resin composition. However, when a large amount of graphite is added to the resin composition, there is a problem that the viscosity of the resin composition increases and it becomes difficult to form the resin composition into a sheet. That is, with the conventional technology, it has been difficult to improve the moldability while improving the thermal conductivity of the thermally conductive pressure-sensitive adhesive sheet-like molded body.

  Then, this invention makes it a subject to provide the heat conductive pressure-sensitive-adhesive sheet-like molded object with high heat conductivity and favorable moldability. It is another object of the present invention to provide a method for producing the heat conductive pressure-sensitive adhesive sheet-like molded article and an electronic device including the heat conductive pressure-sensitive adhesive sheet-like molded article.

  The present inventors have found that the above problem can be solved by using predetermined graphite and a predetermined filler other than graphite in combination at a predetermined ratio, and have completed the present invention.

  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). 100 parts by mass and 500 parts by mass of artificial graphite (B) having an average particle size of 160 μm or more and 700 μm or less, and 50 parts by mass of thermally conductive filler (C) other than graphite having an average particle size of 1 μm or more and 100 μm or less. The polymerization reaction of the (meth) acrylic acid ester monomer (α1) is carried out after forming a mixed composition containing at least 500 parts by weight and not more than 500 parts by mass into a sheet or while forming the mixed composition into a sheet. It is a thermally conductive pressure-sensitive adhesive sheet-like molded body (G) having a thickness of 0.5 mm to 4.5 mm, which is at least performed.

  The definitions of terms used in this specification are described below. “(Meth) acryl” means “acryl and / or methacryl”. “Average particle diameter” means that measured by the method described below. That is, it means that measured by a laser type particle size measuring machine (manufactured by Seishin Enterprise Co., Ltd.) by a micro-sorting control method (a method in which measurement target particles are allowed to pass only in the measurement region and the measurement reliability is improved). . According to this measurement method, by passing 0.01 g to 0.02 g of measurement target particles through the cell, the measurement target particles flowing into the measurement region are irradiated with semiconductor laser light having a wavelength of 670 nm, and the laser at that time By measuring light scattering and diffraction with a measuring instrument, the average particle size and particle size distribution can be calculated from the Franhofer diffraction principle. The “thermally conductive filler” means a filler that can be added to improve the thermal conductivity of the thermally conductive pressure-sensitive adhesive sheet-like molded body (G). 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). In addition, the “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)”, which will be described later as a preferred embodiment, Cross-linking reaction between (meth) acrylic acid ester polymers (A1), cross-linking reaction between polymers containing structural units derived from (meth) acrylic acid ester monomer (α1), and (meth) acrylic acid ester weight Among the crosslinking reactions of the polymer (A1) and the polymer containing a structural unit derived from the (meth) acrylic acid ester monomer (α1), it means one or a plurality of crosslinking reactions.

  In the heat conductive pressure-sensitive adhesive sheet-like molded product (G) of the first aspect of the present invention, artificial graphite (B) is kneaded by adding pitch or tar to coke made from petroleum or coal, and then kneading at 800 ° C. It is preferable that after baking at 1500 ° C. or lower and further graphitizing by heating to 2000 ° C. or higher and 3000 ° C. or lower.

  In the heat conductive pressure-sensitive adhesive sheet-like molded body (G) of the first aspect of the present invention, the heat conductive filler (C) other than graphite is a metal belonging to group 2, 3, or 12 of the long periodic table. It is preferable that an oxide or a hydroxide is included.

  In the heat conductive pressure-sensitive adhesive sheet-like molded body (G) of the first aspect of the present invention, the heat conductive filler (C) other than graphite preferably contains an oxide or hydroxide of aluminum.

  In the heat conductive pressure-sensitive adhesive sheet-like molded body (G) of the first aspect of the present invention, the mixed composition preferably further contains 50 parts by mass or more and 200 parts by mass or less of the phosphate ester (D).

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). 100 parts by mass and 500 parts by mass of artificial graphite (B) having an average particle size of 160 μm or more and 700 μm or less, and 50 parts by mass of thermally conductive filler (C) other than graphite having an average particle size of 1 μm or more and 100 μm or less. And (meth) acrylic acid after forming the mixed composition into a sheet or while forming the mixed composition into a sheet It is a manufacturing method of a heat conductive pressure-sensitive-adhesive sheet-like molded object (G) including the process of performing the polymerization reaction of ester monomer ((alpha) 1).

  In the step of carrying out the polymerization reaction of the (meth) acrylic acid ester monomer (α1) in the method for producing the heat conductive pressure-sensitive adhesive sheet-like molded product (G) of the second aspect of the present invention, the (meth) acrylic It is preferable to heat the acid ester monomer (α1) to a temperature of 100 ° C. or higher and 200 ° C. or lower.

  In the method for producing a heat conductive pressure-sensitive adhesive sheet-like molded body (G) according to the second aspect of the present invention, after artificial graphite (B) is added and kneaded with pitch or tar added to coke made from petroleum or coal. It is preferable to use one that has been baked at 800 ° C. or higher and 1500 ° C. or lower and then further heated to 2000 ° C. or higher and 3000 ° C. or lower and graphitized.

  In the manufacturing method of the heat conductive pressure-sensitive-adhesive sheet-like molded product (G) of the second aspect of the present invention, the heat conductive filler (C) other than graphite is in groups 2, 3, or 12 of the long periodic table. It preferably contains an oxide or hydroxide of the metal to which it belongs.

  In the manufacturing method of the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) of the 2nd aspect of this invention, heat conductive fillers (C) other than graphite may contain the oxide or hydroxide of aluminum. preferable.

  In the manufacturing method of the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) of the 2nd aspect of this invention, 50 mass parts or more and 200 mass parts or less of phosphate ester (D) are further mixed with the said mixed composition. Is preferred.

  The 3rd aspect of this invention is an electronic device provided with the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) of the said 1st aspect of the said this invention bonded by the heat radiator and this heat radiator.

  ADVANTAGE OF THE INVENTION According to this invention, the heat conductive pressure-sensitive-adhesive sheet-like molded object with high heat conductivity and favorable moldability can be provided. Moreover, the manufacturing method of this heat conductive pressure-sensitive-adhesive sheet-like molded object and the electronic device provided with this heat conductive pressure-sensitive-adhesive sheet-like molded object can also be provided.

1. Thermally conductive pressure-sensitive adhesive sheet-shaped product (G)
The heat conductive pressure-sensitive adhesive sheet-like molded product (G) of the present invention includes a (meth) acrylic polymer containing a (meth) acrylic acid ester polymer (A1) and a (meth) acrylic acid ester monomer (α1). Resin composition (A), artificial graphite (B) having an average particle size of 160 μm or more and 700 μm or less (hereinafter sometimes simply referred to as “artificial graphite (B)”), and an average particle size of 1 μm or more and 100 μm or less After forming a mixed composition containing a thermally conductive filler (C) other than graphite (hereinafter sometimes simply referred to as “thermally conductive filler (C)”) into a sheet shape, or At least a polymerization reaction for obtaining a polymer that produces a structural unit derived from the (meth) acrylic acid ester monomer (α1) while being formed into a sheet shape is performed. The main substances constituting such a heat conductive pressure-sensitive adhesive sheet-like molded body (G) will be described 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, when obtaining a heat conductive pressure-sensitive-adhesive sheet-like molded object (G), in addition to the polymerization reaction which obtains the polymer which produces the structural unit derived from the (meth) acrylic acid ester monomer (α1), It is preferable that a crosslinking reaction of a polymer containing a structural unit derived from the acrylate polymer (A1) and / or the (meth) acrylate monomer (α1) is performed. The polymer containing a structural unit derived from the (meth) acrylate monomer (α1) by performing the polymerization reaction and preferably the crosslinking reaction is a component of the (meth) acrylate polymer (A1). Mixed and / or partially combined.

  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. It becomes easy to shape | mold a heat conductive pressure-sensitive-adhesive sheet-like molded object (G) by making the content rate of a (meth) acrylic acid ester monomer ((alpha) 1) into the said range.

((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) acrylic acid ester monomer (a1m) which gives the unit (a1) of the (meth) acrylic acid ester 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 (-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 the 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 mass% or more and 15 mass% or less. 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 carry out, an organic acid group may be introduced by a known polymer reaction after the (meth) acrylic acid ester polymer (A1) is produced.

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

  The amount of the monomer unit (a4) derived from the monomer (a4m) is preferably 10% by mass or less and more preferably 5% by mass or less in the (meth) acrylic acid ester polymer (A1).

  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, vinyltoluene and the like.

  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 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.

  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 polymerization method is not particularly limited, and may be any of solution polymerization, emulsion polymerization, suspension polymerization, bulk polymerization and the like, and may be other methods. However, solution polymerization is preferable. Among these, 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 as the polymerization solvent. 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 may be either a peroxide or an azo compound.

  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 mass part or more and 50 mass parts or less with respect to 100 mass parts of monomers.

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

  After 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 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 a sheet-like molded article (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) acrylate monomer (α1) is a (meth) acrylate monomer (a5m) that forms a homopolymer having a glass transition temperature of −20 ° C. or lower, and can be copolymerized with these monomers. It is good also as a thing containing 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, a heat conductive pressure-sensitive adhesive sheet-like molded article excellent in pressure-sensitive adhesiveness and flexibility ( G) is easily obtained.

  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. 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.

  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.

<Polymerization initiator>
When obtaining a heat conductive pressure-sensitive-adhesive sheet-like molded product (G), the (meth) acrylic acid ester monomer (α1) and a polyfunctional monomer described later are polymerized. In order to accelerate the polymerization, it is preferable to use a polymerization initiator.

  Examples of the polymerization initiator that can be used in the present invention 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 sheet-like molded product (G), it is preferable to use an organic peroxide thermal polymerization initiator.

  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 or less with respect to 100 parts by mass of the (meth) acrylic resin composition (A). It is more preferable that it is 0.3 mass part or more and 1 mass part or less. By making the usage-amount of a polymerization initiator into the said range, it becomes easy to make the polymerization conversion rate of a (meth) acrylic acid ester monomer ((alpha) 1) into an appropriate range, and a heat conductive pressure-sensitive-adhesive sheet-like molded object (G ) To prevent the monomer odor from remaining. 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, it becomes easy to prevent the monomer odor from remaining in the heat conductive pressure-sensitive adhesive sheet-like molded product (G). . 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>
When manufacturing the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) of this invention, it is preferable to use a polyfunctional monomer. 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 as a pressure-sensitive adhesive for the thermally conductive pressure-sensitive adhesive sheet-like molded product (G). The cohesive force of can be increased.

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

  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 Multifunctional (meth) acrylates such as tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and 2,4-bis (trichloro Other substituted triazines, such as chill) -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 production of the heat conductive pressure-sensitive adhesive sheet-like molded product (G) is 0.1 parts by mass or more and 15 parts by mass with respect to 100 parts by mass of the (meth) acrylic resin composition (A). It is preferably no greater than part by mass, more preferably no less than 0.2 parts by mass and no greater than 8 parts by mass, and even more preferably no less than 0.5 parts by mass and no greater than 2 parts by mass. By making the usage-amount of a polyfunctional monomer into the said range, it becomes easy to provide the appropriate cohesion force as a pressure sensitive adhesive to a heat conductive pressure sensitive adhesive sheet-like molded object (G).

<Artificial graphite (B)>
When producing the heat conductive pressure-sensitive adhesive sheet-like molded product (G) of the present invention, artificial graphite (B) having an average particle size of 160 μm or more and 700 μm or less is used. By using the artificial graphite (B) and a heat conductive filler (C) described later in combination in a predetermined amount, the heat conductivity of the heat conductive pressure-sensitive adhesive sheet (G) is improved while improving the heat conductivity. The formability of the pressure-sensitive adhesive sheet-like molded product (G) can be kept good.

  In the present invention, the artificial graphite (B) is preferably obtained by adding a pitch or tar to coke made from petroleum or coal, kneading, firing, and further heating and graphitizing. . By passing through these steps and then pulverizing, artificial graphite (B) having a predetermined size can be obtained. In addition, in the production process of artificial graphite (B), after kneading as described above, it is molded into a cylindrical shape for use in an electrode or the like by extrusion molding, mold molding or rubber press (hydrostatic pressure molding: CIP). It is preferable to do. The firing temperature is preferably 800 ° C. or higher and 1500 ° C. or lower, more preferably 800 ° C. or higher and 1200 ° C. or lower, and particularly preferably 900 ° C. or higher and 1000 ° C. or lower. The temperature when heating after firing is preferably 2000 ° C. or higher and 3000 ° C. or lower, more preferably 2500 ° C. or higher and 3000 ° C. or lower, and particularly preferably 2700 ° C. or higher and 3000 ° C. or lower. By setting the temperature within the above range, artificial graphite (B) with high purity can be obtained.

  The average particle size of the artificial graphite (B) used in the present invention is 160 μm or more and 700 μm or less. The preferred range of the average particle size of the artificial graphite (B) is presumed to depend on the thickness of the heat conductive pressure-sensitive adhesive sheet-like molded product (G) and the particle size of the heat conductive filler (C) described later. For example, they are 250 micrometers or more and 500 micrometers or less.

  Conventionally, there has been a technique for improving the thermal conductivity of the resin composition by mixing artificial graphite with the resin composition, but artificial graphite having a particle size smaller than the range specified in the present invention has been used. This is because it is usually difficult to form a sheet when a filler having a large particle size is used. However, the present inventors set the particle sizes of the artificial graphite (B) and the heat conductive filler (C), the thickness of the heat conductive pressure-sensitive adhesive sheet-like molded body (G), and the like within a predetermined range. By this, it discovered that the moldability of a heat conductive pressure-sensitive-adhesive sheet-like molded object (G) can be maintained favorable, improving the heat conductivity of a heat-conductive pressure-sensitive-adhesive sheet-like molded object (G).

  According to the present invention, by setting the average particle size of the artificial graphite (B) within the above range, the heat conductive pressure-sensitive adhesive sheet-like molded body (G) is combined with the heat conductive filler (C) described later. It becomes easy to impart high thermal conductivity. The combination of the artificial graphite (B) and the heat conductive filler (C) described later makes it easy to impart high thermal conductivity to the heat conductive pressure-sensitive adhesive sheet-shaped molded body (G). Since the particle size of B) is large and the particle size of the heat conductive filler (C) is small, the artificial graphite (B) and the heat conductive filler in the thickness direction of the heat conductive pressure-sensitive adhesive sheet-like molded body (G) It can be inferred that this is because (C) is connected to easily form a path of heat.

  When artificial graphite having an average particle size of less than 160 μm is used, the fluidity of the mixed composition that becomes the element of the heat conductive pressure-sensitive adhesive sheet-like molded product tends to be lowered. When the fluidity of the mixed composition is lowered, it becomes difficult to form the mixed composition into a sheet, and even if the mixed composition can be formed into a sheet, the shape following property of the sheet is lowered. When the sheet having low shape following property is bonded to the heat generating body and the heat radiating body, the adhesiveness between the heat generating body and the heat radiating body becomes poor, and it becomes difficult to transfer heat from the heat generating body to the heat radiating body. On the other hand, even if the heat conductive filler (C) having a particle size smaller than that of the artificial graphite (B) is used, the fluidity of the mixed composition is hardly lowered. It can be inferred that this is different.

  Artificial graphite having an average particle size exceeding 700 μm is difficult to produce. Moreover, when the particle diameter of artificial graphite is too large with respect to the thickness of a heat conductive pressure-sensitive-adhesive sheet-like molded object, it will become difficult to shape | mold into a sheet form. If a thermally conductive pressure-sensitive adhesive sheet-like molded body having a thickness exceeding the thickness specified in the present invention is formed, it is possible to use artificial graphite having an average particle size exceeding 700 μm. A heat-conductive pressure-sensitive adhesive sheet-like molded body having a thickness exceeding the specified thickness range may be impractical because the thermal resistance in the thickness direction increases.

  The amount of the artificial graphite (B) contained in the thermally conductive pressure-sensitive adhesive sheet-like molded body (G) is 100 parts by mass or more and 500 parts by mass or less with respect to 100 parts by mass of the (meth) acrylic resin composition (A). Preferably, they are 250 to 400 mass parts. By setting the content of the artificial graphite (B) in the above range, a high thermal conductivity is imparted to the thermally conductive pressure-sensitive adhesive sheet-like molded body (G) in combination with the thermally conductive filler (C) described later. It becomes easy. On the other hand, if the content of the artificial graphite (B) exceeds 500 parts by mass, the fluidity of the mixed composition that becomes the basis of the thermally conductive pressure-sensitive adhesive sheet-like molded body (G) is lowered, and as described above, It becomes difficult to form the mixed composition into a sheet, and even if it can be formed into a sheet, the shape following property of the sheet is lowered.

<Thermal conductive filler (C)>
A heat conductive filler (C) is used for the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) of this invention. A heat conductive filler (C) is a filler which can improve the heat conductivity of a heat conductive pressure-sensitive-adhesive sheet-like molded object (G) by adding.

  As the thermally conductive filler (C), for example, an oxide or hydroxide of a metal belonging to Group 2, 3, or 12 of the long periodic table can be used. More specifically, calcium carbonate, aluminum hydroxide, magnesium hydroxide, aluminum oxide (alumina), magnesium oxide, silica, glass fiber, boron nitride, aluminum nitride, and the like can be given. Among these, aluminum hydroxide and aluminum oxide are preferable because they are easily available, are chemically stable, and a large amount can be blended. Such a heat conductive filler (C) may be used individually by 1 type, and may use 2 or more types together.

  Moreover, the average particle diameter of the heat conductive filler (C) used for this invention is 1 micrometer or more and 100 micrometers or less. The preferable range of the average particle size of the heat conductive filler (C) is presumed to depend on the thickness of the heat conductive pressure-sensitive adhesive sheet-like molded product (G) and the particle size of the artificial graphite (B). 2 μm or more and 50 μm or less. By making the average particle diameter of the heat conductive filler (C) within the above range, it is easy to impart high heat conductivity to the heat conductive pressure-sensitive adhesive sheet-shaped body (G) in combination with artificial graphite (B). Become. On the other hand, when the average particle size of the heat conductive filler (C) is less than 1 μm, the viscosity of the mixed composition which is the basis of the heat conductive pressure-sensitive adhesive sheet-like molded body (G) tends to be high, and the heat conductive feeling There exists a possibility that the moldability of a pressure-adhesive sheet-like molded object (G) may fall.

  The amount of the thermally conductive filler (C) contained in the thermally conductive pressure-sensitive adhesive sheet-like molded body (G) is 50 parts by mass or more and 500 parts by mass with respect to 100 parts by mass of the (meth) acrylic resin composition (A). Part or less, preferably 250 parts by weight or more and 400 parts by weight or less. By making content of a heat conductive filler (C) into the said range, it becomes easy to provide high heat conductivity to a heat conductive pressure-sensitive-adhesive sheet-like molded object (G) in combination with artificial graphite (B). . On the other hand, when the content of the heat conductive filler (C) exceeds 500 parts by mass, the viscosity of the mixed composition that becomes the basis of the heat conductive pressure-sensitive adhesive sheet-like molded body (G) increases, and the heat conductive pressure-sensitive adhesive is obtained. There is a possibility that the moldability of the sheet-like molded article (G) is lowered.

<Phosphate ester (D)>
Phosphate ester (D) can also be used for the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) of this invention. By using the phosphoric ester (D), it becomes easy to impart flame retardancy to the thermally conductive pressure-sensitive adhesive sheet-like molded body (G).

  The phosphate ester (D) used in the present invention preferably has a viscosity at 25 ° C. of from 3000 mPa · s to 300,000 mPa · s. It becomes easy to prevent that the moldability of a heat conductive pressure-sensitive-adhesive sheet-like molded object (G) deteriorates by making the viscosity of phosphate ester into the said range. 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 (D) 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 (D) is a liquid when mixed, the workability is good, and it becomes easy to form the heat conductive pressure-sensitive adhesive sheet-like molded body (G). When forming the heat conductive pressure-sensitive adhesive sheet-like molded article (G) containing the phosphate ester (D), the heat conductive pressure-sensitive adhesive sheet-like molded article (G) in an environment of 15 ° C. or higher and 100 ° C. or lower. It is preferable to mix each substance which comprises. 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 (D). 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.

  Such phosphate ester (D) may be used individually by 1 type, and may use 2 or more types together.

  The amount of the phosphoric acid ester (D) used in the heat conductive pressure-sensitive adhesive sheet-like molded product (G) of the present invention is 50 parts by mass or more and 200 parts by mass with the (meth) acrylic resin composition (A) being 100 parts by mass. It is preferable that it is below mass parts. By making content of phosphate ester (C) into the said range, it becomes easy to improve the flame retardance of a heat conductive pressure-sensitive-adhesive sheet-like molded object (G).

<Other additives>
In addition to the above-described components, various known additives may be added to the heat conductive pressure-sensitive adhesive sheet-like molded body (G) of the present invention as long as the effects of the present invention are not hindered. Known additives include: foaming agents (including foaming aids); glass fibers; external cross-linking agents; antioxidants such as polyphenols, hydroquinones and hindered amines; thickeners such as acrylic polymer particles; etc. Can be mentioned.

<Thickness>
The thickness of the heat conductive pressure-sensitive adhesive sheet-like molded body (G) is 0.5 mm or more and 4.5 mm or less. By setting the heat conductive pressure-sensitive adhesive sheet-shaped molded body (G) to 0.5 mm or more, air is applied when the heat conductive pressure-sensitive adhesive sheet-shaped 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, the heat conductive pressure-sensitive-adhesive sheet-like molded body (G) is easier to manufacture if it has a certain thickness. From this viewpoint, the lower limit of the thickness of the heat conductive pressure-sensitive adhesive sheet-like molded body (G) is preferably 1 mm, and more preferably 1.5 mm. On the other hand, if the heat-conductive pressure-sensitive adhesive sheet-like molded product (G) is too thick, the thermal resistance in the thickness direction becomes high, and there is a possibility that practicality may be lost. From such a viewpoint, the upper limit of the thickness of the heat conductive pressure-sensitive adhesive sheet-like molded body (G) is preferably 4 mm, and more preferably 3 mm. When the thickness is less than 0.5 mm, the appearance of the heat conductive pressure-sensitive adhesive sheet-like molded product (G) is deteriorated. On the other hand, when the thickness exceeds 4.5 mm, the heat conductive pressure-sensitive adhesive sheet-like molded product is obtained. There is a possibility that the thermal resistance of (G) is increased.

2. Manufacturing Method The thermally conductive pressure-sensitive adhesive sheet-like molded product (G) of the present invention is obtained by mixing the substances described above into a sheet shape, or while forming into a sheet shape, while (meth) acrylic acid It can be obtained by performing at least a polymerization reaction of the ester monomer (α1).

  That is, the manufacturing method of the heat conductive pressure-sensitive-adhesive sheet-like molded product (G) of the present invention comprises (meth) acrylic acid ester polymer (A1) and (meth) acrylic acid ester monomer (α1). A (meth) acrylic resin composition (A) containing, artificial graphite (B) having an average particle size of 160 μm or more and 700 μm or less, and a heat conductive filler (C) other than graphite having an average particle size of 1 μm or more and 100 μm or less, Of the (meth) acrylic acid ester monomer (α1) after forming the mixed composition containing the resin, and after forming the mixed composition into a sheet or while forming the mixed composition into a sheet A step of performing a reaction is included. In addition, it is preferable to include the process of performing the crosslinking reaction of the polymer containing the structural unit derived from the (meth) acrylic acid ester polymer (A1) and / or the (meth) acrylic acid ester monomer (α1). In addition, other usable substances, preferable content ratios of the respective substances, preferable average particle diameters of the respective substances, and the like are as described above, and the description thereof is omitted.

  In the manufacturing method of the heat conductive pressure-sensitive-adhesive sheet-like molded article (G) of the present invention, it is preferable to carry out the polymerization reaction of the (meth) acrylate monomer (α1), and the (meth) acrylate weight It is preferable to heat the polymer (A1) and / or the polymer containing the structural unit derived from the (meth) acrylic acid ester monomer (α1). 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. Suitable methods include, for example, a casting method in which the mixed composition is applied onto a process paper such as a release-treated polyester film, and the mixed composition is sandwiched between two roll-processed process papers and passed between rolls. Examples thereof include a method and a method of controlling the thickness through a die when extruding the mixed composition using an extruder.

  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 sheet-like molded object (G) of this invention can be used as some electronic components etc. with which an electronic device etc. are equipped. At that time, it can be directly molded on a base material such as a heat radiator and provided as a part of a component provided in the 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 crystals, surface conduction electron-emitting device displays (SED), plasma display panels (PDP), or integrated circuits (ICs). be able to.

  In addition, as an example of the method of using the heat conductive pressure-sensitive adhesive sheet-like molded product (G) of the present invention for an electronic device, a method of using the LED light source as described below can be exemplified. That is, it is directly attached to the LED light source; sandwiched between the LED light source and the heat dissipation material (heat sink, fan, Peltier element, heat pipe, graphite sheet, etc.); The heat dissipation material connected to the LED light source (heat sink, fan, Peltier element) , Heat pipe, graphite sheet, etc.); used as a casing surrounding the LED light source; affixed to the casing surrounding the LED light source; and filling a gap between the LED light source and the casing. Application examples of LED light sources include backlight devices for display devices having a transmissive liquid crystal panel (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 sheet-like molded object (G) of this invention, affixing on the housing | casing of an apparatus etc. can be mentioned. For example, in an apparatus used for an automobile or the like, it is affixed to the inside of a casing provided in the automobile; affixed to the outside of the casing provided in the automobile; a heat generating part (car navigation / A fuel cell / heat exchanger) and the casing; and affixing to a heat sink connected to a heat generating part (car navigation / fuel cell / heat exchanger) in the casing of the automobile; Can be mentioned.

  In addition, the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) of this invention can be used by 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; washing dryer; optical semiconductor device combining optical semiconductor elements and phosphors; various power devices; Is mentioned.

  Furthermore, the heat conductive pressure-sensitive-adhesive sheet-like molded product (G) of the present invention is not limited to the above-described method of use, and can be used in other methods depending on the application. For example, used for heat equalization of carpets and warm mats; 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 hygroscopic agent; cooling equipment, clothing, towels, sheets, etc. for cooling humans and animals On the opposite side of the body to the member Used for a pressure member of a fixing device mounted on an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer; Pressurizing a fixing device mounted on an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer Used as a member itself; used as a heat flow control heat transfer section for placing a processing target of a film forming apparatus; used as a heat flow control heat transfer section for mounting a processing target of a film forming apparatus; outer layer of a radioactive substance storage container It can be used between the interior and interior; used in a box body with a solar panel that absorbs sunlight; used between the reflective sheet of the CCFL backlight and the 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.

<Fluidity>
The fluidity of the mixed composition obtained through the first and second mixing steps described below was evaluated. Specifically, the Hobart container in which the mixed composition was put was tilted by 30 ° with respect to the horizontal plane, and the state of the mixed composition after 1 minute was evaluated. The results are shown in Tables 2 and 3. The case where the mixed composition flowed along the inclination was indicated as “◯”, and the case where it did not move was indicated as “X”. The fluidity of the mixed composition makes it easier to form the mixed composition into a sheet. That is, it becomes easy to manufacture a heat conductive pressure-sensitive adhesive sheet-like molded body.

<Thermal resistance>
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 25 mm × 25 mm. The test piece was affixed to an aluminum plate of 150 mm × 150 mm × thickness 3 mm, and a micro ceramic heater (manufactured by Sakaguchi Electric Heat Co., Ltd., trade name: MS) was placed on the surface of the test piece opposite to the side attached to the aluminum plate. −5, 25 mm × 25 mm) was fixed with double-sided tape, and the aluminum plate was suspended. Thereafter, a micro ceramic heater was connected to the slidac, heated at 60 W for 60 minutes, and photographed by thermography. This evaluation was performed in an atmosphere at 23 ° C.

  “Thermal resistance [° C./W]” shown in Table 2 and Table 3 is “{(maximum temperature of the surface of the micro ceramic heater) − (a thermally conductive pressure-sensitive adhesive sheet-like molded body of an aluminum plate is attached. The maximum temperature of the surface on the side opposite to the coated side)} [° C.] / Calorific value [W] ”. In addition, “1 mm equivalent value [° C./W]” shown in Tables 2 and 3 is the thickness of the thermally conductive pressure-sensitive adhesive sheet-like molded body subjected to the above “thermal resistance [° C./W]”. The value divided by [mm] is shown.

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, 0.8 part of a polyfunctional monomer obtained by mixing pentaerythritol triacrylate, pentaerythritol tetraacrylate and pentaerythritol diacrylate in a ratio of 60: 35: 5, and 2-ethylhexyl acrylate (Tables 2 and 4) 3 is abbreviated as “2EHA”) and an organic peroxide thermal polymerization initiator (1,6-bis (t-butylperoxycarbonyloxy) hexane (1 minute half-life temperature is 150 ° C.). And 0.8 parts were weighed with an electronic balance, and these were mixed with 10 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 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, 80 parts of phosphoric acid ester (manufactured by Ajinomoto Fine Techno Co., Ltd., trade name “Reophos 65”, compound name “triaryl isopropylated product”) and artificial graphite (1) (manufactured by Ito Graphite Industries Co., Ltd., commercial product) Name “AGB-Special 20”, specific gravity: 2.4, average particle size: 500 μm, aluminum hydroxide (made by Nippon Light Metal Co., Ltd., trade name “BF-083”, average particle size: 8 μm, BET ratio) 300 parts of surface area: 0.8 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 was hung on the release PET film, and the release PET film was further covered on the mixture composition. This laminate in which the mixed composition was sandwiched between the release PET films was passed through a roll having a distance of 2 mm between them to form a sheet. Thereafter, the laminate was put into an oven and heated at 150 ° C. for 15 minutes. Through this heating step, the acrylate monomer was polymerized and subjected to a crosslinking reaction 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 6 and Comparative Examples 1 to 6)
Sheets (G2 to 6, GC1 to 6) were obtained in the same manner as in Example 1 except that the composition of each substance and the sheet thickness were changed as shown in Tables 2 and 3.
The additives which have not been described so far and used in Examples 2 to 6 and Comparative Examples 1 to 6 are as follows.
Spherical alumina (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name “DAM-45”, specific gravity: 3.9, average particle size: 45 μm)
Artificial graphite (2) (manufactured by Ito Graphite Industries Co., Ltd., trade name “AGB-32”, specific gravity: 2.4, average particle size: 250 μm)
Artificial graphite (3) (manufactured by Ito Graphite Industries Co., Ltd., trade name “AGB-130”, specific gravity: 2.4, average particle size: 80 μm)
・ Ringen-shaped graphite (product name “Z + 80”, manufactured by Ito Graphite Industries Co., Ltd., specific gravity: 2.4, average particle size: 250 μm)

As shown in Table 2, the sheets (G1) to (G6) according to the examples all had good fluidity of the mixed composition before being formed into a sheet shape, and it was easy to form into a sheet shape. . Further, the sheets (G1) to (G6) had a low thermal resistance value and excellent thermal conductivity. On the other hand, as shown in Table 3, the sheets (GC1) to (GC6) according to the comparative examples are difficult to be formed into a sheet shape or have a high thermal resistance value even if they can be formed into a sheet shape. The conductivity was poor. Specifically, it was as follows.
-Comparative example 1: The sheet | seat (GC1) of the comparative example 1 which does not contain predetermined heat conductive fillers other than graphite was inferior in thermal conductivity. It can be inferred that it is difficult to form a path through which heat passes in the thickness direction of the sheet only with artificial graphite having a relatively large particle size.
-Comparative example 2: The sheet | seat (GC2) of the comparative example 2 whose content of predetermined | prescribed artificial graphite is less than the range prescribed | regulated by this invention was also inferior in thermal conductivity. It can be inferred that it was difficult to form a path through which heat passes in the thickness direction of the sheet due to the low content of artificial graphite.
Comparative Example 3: In Comparative Example 3, the same amount of artificial graphite having a particle size that is often used in the past was used as the artificial graphite used in the examples. As a result, the cause was not clear, but the fluidity of the mixed composition was inferior, and it was difficult to form into a sheet.
Comparative Example 4: In Comparative Example 4, natural graphite (phosphorus-like graphite) having the same particle size and specific gravity as the artificial graphite used in the examples was used. As a result, the cause was not clear, but the fluidity of the mixed composition was inferior, and it was difficult to form into a sheet.
-Comparative example 5: The sheet | seat (GC5) of the comparative example 5 whose sheet thickness is less than the range prescribed | regulated by this invention was inferior in thermal conductivity. This is because the particle size of the artificial graphite used was large with respect to the sheet thickness, so that the surface state of the sheet was able to be formed into a sheet shape, but was not in close contact with the aluminum plate and the heater. I can guess.
-Comparative example 6: The sheet | seat (GC6) of the comparative example 6 whose sheet | seat thickness exceeded the range prescribed | regulated by this invention was also inferior in thermal conductivity.

Claims (7)

100 parts by weight of (meth) acrylic acid ester polymer (A1) and (meth) acrylic resin composition (A1) containing (meth) acrylic acid ester monomer (α1),
Artificial graphite (B) having an average particle size of 160 μm or more and 700 μm or less, and 100 parts by mass or more and 500 parts by mass or less,
50 parts by mass or more and 500 parts by mass or less of a thermally conductive filler (C) other than graphite having an average particle size of 1 μm or more and 100 μm or less;
Producing a mixed composition comprising:
A step of performing a polymerization reaction of 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. In the step of polymerizing the (meth) acrylic acid ester monomer (α1), the (meth) acrylic acid ester monomer (α1) is heated to a temperature of 100 ° C. or higher and 200 ° C. or lower. to manufacturing method for the heat-conductive and pressure-sensitive adhesive sheet-like molded article according to claim 1 (G). A step of adding pitch or tar to coke made from petroleum or coal, kneading, and baking at 800 ° C. or higher and 1500 ° C. or lower, and further heating to 2000 ° C. or higher and 3000 ° C. or lower to graphitize the artificial graphite. The manufacturing method of the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) of Claim 1 or 2 using what passed through. The graphite non-thermally conductive filler (C) is 2, 3 of the long periodic table, or comprising a metal oxide or hydroxide of belonging to Group 12, according to any one of claims 1 to 3 Manufacturing method of heat conductive pressure-sensitive-adhesive sheet-like molded object (G). The thermally conductive pressure-sensitive adhesive sheet-like molded product (G) according to any one of claims 1 to 4 , wherein the thermally conductive filler (C) other than the graphite contains an oxide or hydroxide of aluminum. Manufacturing method. The mixture composition is further mixed with 200 parts by mass or less than 50 parts by weight of phosphoric acid ester (D), heat-conductive and pressure-sensitive adhesive sheet-like molded article according to any one of claims 1 to 5 (G ) Manufacturing method. The manufacturing method of the electronic device which bonds the heat conductive pressure-sensitive-adhesive sheet-like molded object (G) as described in any one of Claims 1-6 to a heat radiator.