JP2015019059A - Heat dissipation sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat dissipation sheet that is totally excellent in thermal conductivity, thermal resistance, viscosity and moisture and humidity resistance even if an adhesive layer is thin, and that can be used not only when fixing a component, or dissipating heat therefrom, in an electronic apparatus used in a lighting fixture using a light-emitting diode (LED), electroluminescence, or the like, a lighting fixture for back light, a solar cell, a battery such as a lithium ion battery, a computer component such as IC, CPU, a power controller such as a module, a power supply circuit of an inverter, or the like, a touch panel, an electromagnetic shield, a smart phone or a tablet terminal requiring the thinning, or wireless power supply, but also can be used as an adhesive heat dissipation sheet for giving viscosity to a graphite sheet, a metal foil, and their finished article.SOLUTION: A heat dissipation sheet is composed of a heat dissipation material containing an adhesive resin, an inorganic filler and a hardener, and has a thickness of 1-50 μm.

Description

  The present invention relates to a heat dissipation sheet. More specifically, the present invention relates to a heat radiating sheet that can be suitably used as an adhesive heat radiating sheet or the like when, for example, a wiring board and a member that requires heat radiating properties such as a heat sink and a housing are joined. In addition, in this specification, a heat radiating sheet is a thing of the concept containing a heat radiating tape.

  A sheet made of a resin composition in which a heat-conductive filler such as alumina or silica is blended with a flexible resin may have a non-smooth surface such as a heating element or a heat radiator used for the sheet. Therefore, the sheet is required to be flexible in order to follow these surfaces.

  As a heat conductive material having flexibility, silicone is used as a base material, and a heat conductive material filled with a semiconductor heat conductive filler (see, for example, Patent Document 1), alumina powder, zinc oxide powder, silicone gel, and A thermally conductive material containing an alkylalkoxysilane (see, for example, Patent Document 2) has been proposed. However, silicone and silicone gel are not only low in adhesiveness, but also low molecular weight siloxane compounds contained therein cause poor connection of electronic parts and the like, so their use is practically limited.

  As a heat-dissipating sheet having good heat dissipation, a heat-dissipating sheet in which graphite, which is a material having good heat conductivity, is bound with as little binder resin as possible and the thickness of the sheet is made as thin as possible has been proposed (for example, Patent Document 3). reference). However, since the heat dissipation sheet is at most 80 to 120 μm even if the thickness of the sheet is small, it cannot be said that the sheet is thin, and it is practical when the thickness of the heat dissipation sheet is 50 μm or less. There is a disadvantage that it has no mechanical strength.

  On the other hand, with the thinning of electronic devices, thin adhesive tapes are used when fixing electronic devices used inside smartphones and tablet terminals or attaching heat-dissipating sheets such as graphite sheets. However, since the said adhesive tape does not have sufficient heat dissipation, the heat dissipation with respect to an electronic device is inadequate.

  Therefore, development of a heat radiating sheet or pressure-sensitive heat radiating sheet that is comprehensively excellent in thermal conductivity, heat resistance, pressure-sensitive adhesiveness, and heat and humidity resistance even when the pressure-sensitive adhesive layer is thin is awaited.

JP 2003-197833 A JP 2011-084221 A JP 2006-086271 A

  The present invention has been made in view of the above prior art, and provides a heat-dissipating sheet that is comprehensively excellent in thermal conductivity, thermal resistance, adhesiveness, and heat and humidity resistance even when the adhesive layer is thin. The purpose is to do. Another object of the present invention is to provide a heat-dissipating sheet that is comprehensively excellent in heat resistance, adhesiveness after a long period of time, heat and humidity resistance, and punching processability.

  The present invention relates to a heat radiating sheet made of a heat radiating material containing an adhesive resin, an inorganic filler, and a curing agent, and having a thickness of 1 to 50 μm. The heat-dissipating sheet of the present invention is made of a heat-dissipating material containing an inorganic filler and a curing agent, and has a thickness of 1 to 50 μm. Therefore, even if the adhesive layer is thin, thermal conductivity, thermal resistance, adhesiveness It is also excellent in heat and humidity resistance.

  In the heat dissipation sheet of the present invention, when the heat dissipation material contains an adhesive resin, an inorganic filler, a tackifier, and a curing agent, the heat resistance, the adhesiveness after a long time, the heat and humidity resistance, and the punching processability It is preferable because it is excellent overall.

  The amount of the inorganic filler per 100 parts by mass of the nonvolatile content of the adhesive resin is preferably 10 to 600 parts by mass from the viewpoint of improving the dispersion stability of the inorganic filler and the thermal conductivity and adhesiveness of the heat-dissipating sheet. Moreover, it is preferable that the quantity of the hardening | curing agent per 100 mass parts of non volatile matters of adhesive resin is 0.3-5 mass parts from a viewpoint which suppresses the cohesive failure of a heat-radiation sheet, and improves adhesiveness.

  The heat dissipating material used in the present invention contains an adhesive resin, an inorganic filler having a maximum particle size of 0.01 to 20 μm, and a curing agent. Even if the adhesive layer is thin, thermal conductivity and thermal resistance are included. Can be suitably used as a raw material for a heat-dissipating sheet that is comprehensively excellent in heat resistance, adhesiveness, and heat and humidity resistance.

  Moreover, the amount of the tackifier per 100 parts by mass of the non-volatile content of the adhesive resin is 1 to 95 parts by mass from the viewpoint of improving the punching processability and improving the adhesiveness and heat and humidity resistance. preferable.

  ADVANTAGE OF THE INVENTION According to this invention, even if the thickness of the adhesion layer is thin, the heat dissipation sheet excellent in heat conductivity, heat resistance, adhesiveness, and heat-and-humidity heat resistance is provided. Moreover, according to this invention, the heat dissipation sheet excellent in heat resistance, the adhesiveness after progress for a long time, heat-and-humidity heat resistance, and punching workability is provided.

  The heat dissipating material used in the present invention contains an adhesive resin, an inorganic filler and a curing agent, but it is preferable to further contain a tackifier from the viewpoint of improving the punching processability.

  Examples of the adhesive resin include (meth) acrylic adhesive resin, silicone adhesive resin, urethane adhesive resin, vinyl alkyl ether adhesive resin, vinylpyrrolidone adhesive resin, acrylamide adhesive resin, Cellulose-based adhesive resins, rubber-based heat dissipation sheets, and the like can be mentioned, but the present invention is not limited to such examples. These adhesive resins may be used alone or in combination of two or more, as long as the object of the present invention is not impaired.

  Among adhesive resins, (meth) acrylic adhesive resin is excellent in adhesiveness and constant load peelability, can be used for various adherends, and has a wide range of versatility. (Meth) acrylic adhesive resin obtained by polymerizing a monomer component mainly composed of (meth) acrylic acid alkyl ester is more preferable.

  The “monomer component mainly composed of (meth) acrylic acid alkyl ester” means that the content of the (meth) acrylic acid alkyl ester in the monomer component is 50% by mass or more. The content of the (meth) acrylic acid alkyl ester in the monomer component is 50% by mass or more, preferably 60% by mass or more, more preferably 70% by mass or more, and still more preferably 80% by mass from the viewpoint of improving adhesiveness. % Or more. The upper limit of the content of the (meth) acrylic acid alkyl ester in the monomer component is preferably 100% by mass, more preferably 97% by mass or less, more preferably from the viewpoint of improving heat resistance. It is 95 mass% or less.

  Among (meth) acrylic acid alkyl esters, they are excellent in adhesiveness, can be used for various adherends, and have a wide range of versatility, from the viewpoint of obtaining (meth) acrylic adhesive resins. (Meth) acrylic acid alkyl ester having 1 to 18 carbon atoms in the ester is preferable, and alkyl alkyl ester having 1 to 18 carbon atoms in the alkyl ester is more preferable. Suitable alkyl (meth) acrylates include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, sec- Butyl (meth) acrylate, tert-butyl (meth) acrylate, isobutyl (meth) acrylate, n-pentyl (meth) acrylate, isopentyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl acrylate, n-heptyl ( (Meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (Meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, isomyristyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate, n-stearyl (meth) acrylate, iso Although stearyl (meth) acrylate, n-lauryl (meth) acrylate, etc. are mentioned, this invention is not limited only to this illustration. These (meth) acrylic acid esters may be used alone or in combination of two or more. Among these (meth) acrylic acid alkyl esters, from the viewpoint of improving adhesiveness, alkyl alkyl esters having 1 to 18 carbon atoms of the alkyl ester are preferable, and n-butyl acrylate, n-octyl acrylate, Octyl acrylate and 2-ethylhexyl acrylate are more preferable, and n-butyl acrylate and 2-ethylhexyl acrylate are more preferable.

  In the present specification, “(meth) acrylate” means “acrylate” and / or “methacrylate”, and “(meth) acryl” means “acryl” and / or “methacryl”.

  The monomer component may contain a monomer other than the (meth) acrylic acid alkyl ester as long as the object of the present invention is not impaired. As monomers other than (meth) acrylic acid alkyl ester, for example, a monomer having a carboxyl group, a monomer having a hydroxyl group, an acidic phosphate ester monomer, a monomer having an epoxy group, nitrogen Monomers having atoms, monomers having two or more polymerizable double bonds, aromatic monomers, monomers having halogen atoms, vinyl ester monomers, vinyl ether monomers, etc. However, the present invention is not limited to such examples. These monomers may be used alone or in combination of two or more. Among these monomers, a monomer having a carboxyl group and a monomer having a hydroxyl group are preferable.

  Examples of the monomer having a carboxyl group include acrylic acid, methacrylic acid, itaconic acid, maleic anhydride and the like, but the present invention is not limited only to such illustration. These monomers having a carboxyl group may be used alone or in combination of two or more. Among these monomers having a carboxyl group, acrylic acid, methacrylic acid, itaconic acid and maleic anhydride are preferable, acrylic acid and methacrylic acid are more preferable, and acrylic acid is preferable from the viewpoint of improving adhesiveness and heat-and-moisture resistance. Is more preferable. The content of acrylic acid in the monomer component is preferably 0.3% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, from the viewpoint of improving adhesiveness and heat-and-moisture resistance. From the viewpoint of improving the tackiness and heat-and-moisture resistance, it is preferably 20% by mass or less, more preferably 10% by mass or less. In addition, since the monomer which has a carboxyl group has a carbon-carbon double bond and a carboxyl group, it is a polyfunctional monomer.

  Examples of the monomer having a hydroxyl group include 2 to 4 carbon atoms of a hydroxyalkyl group such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, and hydroxybutyl methacrylate. However, the present invention is not limited to such examples. These monomers having a hydroxyl group may be used alone or in combination of two or more. Among these monomers having a hydroxyl group, 2-hydroxyethyl acrylate is preferable. Since the monomer having an acid group has a carbon-carbon double bond and a hydroxyl group, it is a polyfunctional monomer.

  Examples of acidic phosphate ester monomers include 2-acryloyloxyethyl acid phosphate and 2-methacryloyloxyethyl acid phosphate, but the present invention is not limited to such examples. These acidic phosphate ester monomers may be used alone or in combination of two or more.

  Examples of the monomer having an epoxy group include (meth) acrylic acid esters having an epoxy group such as glycidyl acrylate and glycidyl methacrylate, but the present invention is not limited to such examples. These monomers having an epoxy group may be used alone or in combination of two or more. A monomer having an epoxy group is a polyfunctional monomer because it has a carbon-carbon double bond and an epoxy group.

  Examples of the monomer having a nitrogen atom include N-vinylpyrrolidone, (meth) acrylamide such as acrylamide and methacrylamide, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, and imide acrylate. , Having a nitrogen atom such as imide methacrylate, 2-isopropenyl-2-oxazoline, 2-vinyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, N-hydroxyethyl (meth) acrylamide (meth) Although acrylate etc. are mentioned, this invention is not limited only to this illustration. These monomers having a nitrogen atom may be used alone or in combination of two or more. Among the monomers having a nitrogen atom, N-vinylpyrrolidone is preferable from the viewpoint of improving adhesiveness and heat and humidity resistance. The content of N-vinylpyrrolidone in the monomer component is preferably 0.3% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass from the viewpoint of improving adhesiveness and heat-and-moisture resistance. From the viewpoint of improving the adhesiveness and heat and humidity resistance, it is preferably 20% by mass or less, more preferably 10% by mass or less.

  Examples of the monomer having two or more polymerizable double bonds include ethylene glycol diacrylate, ethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tripropylene glycol diacrylate, and tripropylene glycol. Examples include dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, methyl allyloxymethyl acrylate, etc., but the present invention is not limited to such examples. Absent. These monomers having two or more polymerizable double bonds may be used alone or in combination of two or more. A monomer having two or more polymerizable double bonds is a polyfunctional monomer because it has two or more polymerizable double bonds.

  Examples of the aromatic monomer include styrene compounds such as styrene and α-methylstyrene, but the present invention is not limited to such examples. These aromatic monomers may be used alone or in combination of two or more.

  Examples of the monomer having a halogen atom include vinyl halides such as vinyl chloride, but the present invention is not limited to such examples. Only one type of monomer having a halogen atom may be used, or two or more types may be used in combination.

  Examples of vinyl ester monomers include fatty acid vinyls such as vinyl acetate, but the present invention is not limited to such examples. Only one type of vinyl ester monomer may be used, or two or more types may be used in combination. Among the vinyl ester monomers, vinyl acetate is preferable from the viewpoint of improving the adhesiveness, heat-and-moisture resistance and punching processability. The content of vinyl acetate in the monomer component is preferably 0.3% by mass or more, more preferably 0.5% by mass or more, and still more preferably 1 from the viewpoint of improving adhesiveness, heat-and-moisture resistance and punching processability. From the viewpoint of improving adhesiveness, heat-and-moisture resistance and punching workability, it is preferably 20% by mass or less, and more preferably 10% by mass or less.

  Examples of vinyl ether monomers include butyl vinyl ether and cyclohexyl vinyl ether, but the present invention is not limited to such examples. These vinyl ether monomers may be used alone or in combination of two or more.

  The content of monomers other than the alkyl acrylate ester in the monomer component is 50% by mass or less, preferably 40% by mass or less, more preferably 30% by mass or less, and still more preferably, from the viewpoint of improving adhesiveness. It is 20 mass% or less. Further, the lower limit of the content of the monomer other than the alkyl acrylate ester in the monomer component is preferably 0% by mass, more preferably 3% by mass or more from the viewpoint of improving heat resistance. Preferably it is 5 mass% or more.

  The adhesive resin has a crosslinkable group in order to be cured with a curing agent. The adhesive resin having a crosslinkable group can be prepared by allowing the monomer component to contain the polyfunctional monomer.

  Among polyfunctional monomers, from the viewpoint of obtaining a heat radiation sheet that is comprehensively excellent in thermal conductivity, thermal resistance, adhesiveness, and heat and humidity resistance even when the adhesive layer is thin, for example, (Metal ) A monomer having a carboxyl group such as acrylic acid, a monomer having a hydroxyl group such as 2-hydroxyethyl acrylate, and a monomer having two or more polymerizable double bonds are preferable, and a monomer having a carboxyl group And monomers having a hydroxyl group and a hydroxyl group are more preferred.

  The content of the polyfunctional monomer in the monomer component cannot be determined unconditionally because it varies depending on the type of the polyfunctional monomer, etc., but usually from the viewpoint of sufficiently curing the adhesive resin, Preferably, it is 0.1% by mass or more, more preferably 0.2% by mass or more, and further preferably 0.3% by mass or more. From the viewpoint of improving adhesiveness, it is preferably 10% by mass or less, more preferably 5% by mass. It is not more than mass%, more preferably not more than 3 mass%, still more preferably not more than 1 mass%.

  When polymerizing the monomer component, a chain transfer agent may be used as necessary from the viewpoint of suppressing an increase in molecular weight distribution and gelation. Examples of the chain transfer agent include mercaptocarboxylic acids such as mercaptoacetic acid and 3-mercaptopropionic acid; methyl mercaptoacetate, methyl 3-mercaptopropionate, 2-ethylhexyl 3-mercaptopropionate, and n-octyl 3-mercaptopropionate. , Methoxybutyl 3-mercaptopropionate, stearyl 3-mercaptopropionate, trimethylolpropane tris (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptopropionate), dipentaerythritol hexakis (3-mercapto Mercaptocarboxylic esters such as propionate); alkyl such as ethyl mercaptan, tert-butyl mercaptan, n-dodecyl mercaptan, 1,2-dimercaptoethane Llucaptans; mercaptoalcohols such as 2-mercaptoethanol and 4-mercapto-1-butanol; aromatic mercaptans such as benzenethiol, m-toluenethiol, p-toluenethiol and 2-naphthalenethiol; tris [(3- Mercaptopropionyloxy) ethyl] isocyanurate; mercaptoisocyanurates; dihydroxys such as 2-hydroxyethyl disulfide and tetraethylthiuram disulfide; dithiocarbamates such as benzyldiethyldithiocarbamate; dimers such as α-methylstyrene dimer; Examples include halogenated alkyls such as carbon tetrabromide, but the present invention is not limited to such examples. These chain transfer agents may be used alone or in combination of two or more. Among these chain transfer agents, mercaptocarboxylic acids, mercaptocarboxylic acid esters, alkyl mercaptans are obtained because they are easily available, have excellent anti-crosslinking properties, and have a low degree of decrease in polymerization rate. Compounds having a mercapto group such as mercaptoalcohols, aromatic mercaptans and mercaptoisocyanurates are preferred.

  The amount of the chain transfer agent may be appropriately set according to the composition of the monomer component, the polymerization conditions such as the polymerization temperature, the molecular weight of the target polymer, etc., and is not particularly limited, but the weight average molecular weight is several thousand to When obtaining tens of thousands of polymers, the amount is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 15 parts by mass per 100 parts by mass of the monomer component.

  Examples of the method for polymerizing the monomer component include a bulk polymerization method, a solution polymerization method, a dispersion polymerization method, a suspension polymerization method, and an emulsion polymerization method, but the present invention is limited to such examples. It is not a thing.

  Bulk polymerization can be performed, for example, by irradiation with energy rays such as ultraviolet rays, electron beams, or radiation, or heating. When bulk polymerization of monomer components is performed by irradiation with energy rays, for example, the monomer components are irradiated by irradiation with energy rays in an inert gas atmosphere such as nitrogen gas or in an atmosphere where air is shut off. It is preferable to polymerize the monomer component.

  When polymerizing the monomer component by the bulk polymerization method, a photopolymerization initiator can be used. Examples of the photopolymerization initiator include an acetophenone polymerization initiator, a benzoin ether polymerization initiator, a benzyl ketal polymerization initiator, an acyl phosphine oxide polymerization initiator, a benzoin polymerization initiator, and a benzophenone polymerization initiator. However, the present invention is not limited to such examples. These photopolymerization initiators may be used alone or in combination of two or more. The amount of the photopolymerization initiator may be appropriately set according to the desired physical properties of the polymer to be obtained, but is usually preferably 0.01 to 50 parts by mass, more preferably 100 parts by mass of the monomer component. Is 0.03 to 20 parts by mass.

  When the monomer component is polymerized by the solution polymerization method, examples of the solvent include aromatic solvents such as benzene, toluene and xylene; alcohol solvents such as isopropyl alcohol and n-butyl alcohol; propylene glycol methyl ether and dipropylene. Ether solvents such as glycol methyl ether, ethyl cellosolve, butyl cellosolve; ester solvents such as ethyl acetate, butyl acetate, cellosolve; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, diacetone alcohol; amides such as dimethylformamide Although organic solvents, such as a system solvent, are mentioned, this invention is not limited only to this illustration. These solvents may be used alone or in combination of two or more. The amount of the solvent may be appropriately determined in consideration of the polymerization conditions, the composition of the monomer components, the concentration of the resulting polymer, and the like.

  When the monomer component is polymerized by a solution polymerization method, a polymerization initiator can be used. Examples of the polymerization initiator include azoisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2-methylbutyronitrile), tert-butylperoxy 2-ethylhexanoate, 2,2′-azobisisobutyronitrile, benzoyl peroxide, di-tert-butyl peroxide, and the like, but the present invention is not limited to such examples. Absent. These polymerization initiators may be used alone or in combination of two or more. The amount of the polymerization initiator may be appropriately set according to the desired physical properties of the polymer to be obtained, but is usually preferably 0.001 to 20 parts by mass, more preferably 100 parts by mass of the monomer component. 0.005 to 10 parts by mass.

  The polymerization conditions for polymerizing the monomer components may be set as appropriate according to the polymerization method, and are not particularly limited. The polymerization temperature is preferably room temperature to 200 ° C, more preferably 40 to 140 ° C. Moreover, it is preferable that the atmosphere at the time of polymerizing a monomer component is inert gas, such as nitrogen gas and argon gas. What is necessary is just to set reaction time suitably so that the polymerization reaction of a monomer component may be completed.

  By polymerizing the monomer components as described above, a (meth) acrylic adhesive resin is obtained.

The weight average molecular weight of the (meth) acrylic adhesive resin is preferably 100,000 or more, more preferably 200,000 or more, from the viewpoint of improving the adhesiveness and heat / humidity resistance of the heat dissipation sheet and the dispersion stability of the inorganic filler. More preferably, it is 300,000 or more. The upper limit of the weight average molecular weight of the (meth) acrylic adhesive resin is not particularly limited, but from the viewpoint of improving the adhesiveness and heat / humidity resistance of the heat dissipation sheet and the dispersion stability of the inorganic filler, preferably 1.5 million or less, More preferably, it is 1.2 million or less, More preferably, it is 1 million or less, More preferably, it is 900,000 or less.

  In addition, in this specification, the weight average molecular weight of (meth) acrylic-type adhesive resin is a Tosoh Co., Ltd. product number: HLC-8220GPC, as a measuring device of a gel permeation chromatography (GPC), separation column: Tosoh Co., Ltd., product number: TSKgel Super HZM-M is used, which means a conversion value by standard polystyrene [manufactured by Tosoh Co., Ltd.].

  The glass transition temperature of the (meth) acrylic adhesive resin can be easily adjusted by appropriately adjusting the type and amount of the monomer used in preparing the (meth) acrylic adhesive resin.

  The glass transition temperature (Tg) of the (meth) acrylic adhesive resin is preferably −65 ° C. or higher, more preferably −63 ° C. or higher, more preferably −62 ° C. or higher, from the viewpoint of improving the adhesiveness of the heat dissipation sheet. From the viewpoint of improving the adhesiveness and heat / humidity resistance of the heat dissipation sheet, it is preferably −20 ° C. or lower, more preferably −30 ° C. or lower, and further preferably −40 ° C. or lower.

In the present specification, the glass transition temperature of the (meth) acrylic adhesive resin is the glass transition temperature of the homopolymer of the monomer used in the monomer component used as a raw material for the (meth) acrylic adhesive resin. Use the formula:
1 / Tg = Σ (Wm / Tgm) / 100
[Wm represents the content (% by mass) of monomer m in the monomer component constituting the polymer, and Tgm represents the glass transition temperature (absolute temperature: K) of the homopolymer of monomer m]
The temperature calculated | required based on the Formula of Fox (Fox) represented by these.

  If the glass transition temperature (Tg) of the main homopolymer is indicated, for example, the glass transition temperature (Tg) of the homopolymer of n-butyl acrylate is −54 ° C., the glass transition temperature of the homopolymer of 2-ethylhexyl acrylate ( Tg) is -70 ° C., N-vinylpyrrolidone homopolymer glass transition temperature (Tg) is 180 ° C., acrylic acid homopolymer glass transition temperature (Tg) is 106 ° C., and allyloxymethyl acrylate homopolymer. The glass transition temperature (Tg) of the homopolymer of 2-hydroxyethyl acrylate is -15 ° C., the glass transition temperature (Tg) of the homopolymer of vinyl acetate is 32 ° C. The glass transition temperature (Tg) of the homopolymer is 130 ° C., and the homopolymer glass of methyl acrylate The transition temperature (Tg) is 8 ° C, the glass transition temperature (Tg) of the homopolymer of ethyl acrylate is -22 ° C, the glass transition temperature (Tg) of the homopolymer of 2-hydroxyethyl methacrylate is 55 ° C, 4-hydroxybutyl acrylate The glass transition temperature (Tg) of the homopolymer of -32 ° C, the glass transition temperature (Tg) of the homopolymer of methyl methacrylate is 105 ° C, the glass transition temperature (Tg) of the homopolymer of acrylonitrile is 125 ° C, and the homopolymer of styrene Has a glass transition temperature (Tg) of 100 ° C.

  In the present specification, the glass transition temperature of the (meth) acrylic adhesive resin means a glass transition temperature obtained based on the above formula unless otherwise specified. For monomers with unknown glass transition temperature such as special monomers and polyfunctional monomers, the total amount of monomers with unknown glass transition temperature in the monomer component is 10% by mass. In the following cases, the glass transition temperature is determined using only monomers whose glass transition temperature is known. When the total amount of monomers with unknown glass transition temperatures in the monomer component exceeds 10% by mass, the glass transition temperature of the (meth) acrylic adhesive resin is determined by differential scanning calorimetry (DSC), differential It is determined by calorimetric analysis (DTA), thermomechanical analysis (TMA) or the like.

  Considering the glass transition temperature of the (meth) acrylic adhesive resin, the composition of the monomer component used as a raw material for the (meth) acrylic adhesive resin can be determined.

  Examples of the differential scanning calorimeter measuring device include Seiko Instruments Inc., product number: DSC220C. Further, when measuring the differential scanning calorific value, a method of drawing a differential scanning calorific value (DSC) curve, a method of obtaining a first derivative curve from the differential scanning calorific value (DSC) curve, a method of performing a smoothing process, and a method of obtaining a target peak temperature There is no limitation in particular. For example, when the measuring device is used, the drawing may be performed from data obtained by using the measuring device. At that time, analysis software capable of performing mathematical processing can be used. Examples of the analysis software include analysis software [manufactured by Seiko Instruments Inc., product number: EXSTAR6000], but the present invention is not limited to such examples. In addition, the peak temperature obtained in this way may include an error due to plotting of about 5 ° C. up and down.

  Examples of the inorganic filler include plate-like inorganic particles and spherical inorganic particles. These particles may be used alone or in combination of two or more, but from the viewpoint of obtaining a heat dissipation sheet excellent in thermal conductivity and thermal resistance even if the thickness of the adhesive layer is thin, It is preferable to use plate-like inorganic particles and spherical inorganic particles in combination. As described above, when the plate-like inorganic particles and the spherical inorganic particles are used in combination, a heat dissipation sheet excellent in thermal conductivity and heat resistance can be obtained even if the adhesive layer is thin due to the synergistic effect of the combined use of both. There is an advantage that can be.

  The mass ratio of the plate-like inorganic particles to the spherical inorganic particles (plate-like inorganic particles / spherical inorganic particles) is a heat dissipation with excellent thermal conductivity and heat resistance even when the adhesive layer is thin due to the synergistic effect of the combined use of both. From the viewpoint of obtaining a sheet, it is preferably 0.3 / 100 or more, more preferably 0.6 / 100 or more, and still more preferably 1/100 or more. From the viewpoint of obtaining a heat radiation sheet excellent in thermal conductivity and thermal resistance, it is preferably 100/00 or less, more preferably 50/100 or less, and still more preferably 30/100 or less.

  Examples of the plate-like inorganic particles include alkali metals such as sodium and potassium, alkaline earth metals such as magnesium and calcium, typical metals such as graphite, aluminum, zinc and tin, iron, nickel, copper, manganese, silver and platinum Plate-like metal particles made of transition metals such as alumina; silica, titania, zirconia, magnesia, yttria, zinc oxide, iron oxide, silicon nitride, titanium nitride, boron nitride, silicon carbide, light calcium carbonate, heavy Calcium carbonate, aluminum sulfate, aluminum hydroxide, potassium titanate, talc, kaolin clay, kaolinite, halloysite, pyrophyllite, montmorillonite, sericite, mica, amicite, bentonite, asbestos, zeolite, calcium silicate, ke Magnesium acid, diatomaceous earth, but such an inorganic material plated mineral particles such as silica sand and the like, and the present invention is not limited only to those exemplified. These plate-like inorganic particles may be used alone or in combination of two or more. Among the plate-like inorganic particles, from the viewpoint of improving thermal conductivity, plate-like inorganic particles made of aluminum, silver, copper or an alloy thereof, plate-like inorganic particles made of boron nitride, plate-like inorganic particles made of graphite, Plate-like inorganic particles made of alumina, talc and mica are preferable, plate-like inorganic particles made of aluminum, silver, copper or their alloys, plate-like inorganic particles made of boron nitride, plate-like inorganic particles made of graphite and alumina Plate-like inorganic particles are more preferred, and plate-like inorganic particles made of aluminum, silver, copper or their alloys, plate-like inorganic particles made of boron nitride, and plate-like inorganic particles made of graphite are more preferred. Each of the plate-like inorganic particles may be used alone or in combination of two or more.

  If necessary, the plate-like inorganic particles may be subjected to a surface treatment. Surface treatment includes, for example, silane coupling treatment, titanate treatment, oxidation treatment, resin coating treatment, energy ray irradiation treatment, electrochemical treatment, and the like, saturated fatty acids such as stearic acid, oleic acid, linoleic acid and the like. Although the process etc. which adsorb | suck a saturated fatty acid to plate-like inorganic particle | grains are mentioned, this invention is not limited only to this illustration. Among these surface treatments, the plate-like inorganic particles subjected to the resin coating treatment are preferable because they are excellent in insulation.

  Examples of the resin used for the plate-like inorganic particles subjected to the resin coating treatment, that is, the particles coated with the resin include acrylic resins, but the present invention is not limited to such examples. Absent. Among the acrylic resins, for example, an acrylic resin obtained by polymerizing a monomer component mainly composed of an acrylate ester is preferable, and trimethylolpropane triacrylate, acrylic acid, epoxidized polybutadiene, and divinylbenzene are used. A resin obtained by polymerizing the monomer component to be contained is more preferable.

  The coating amount of the resin in the plate-like inorganic particles coated with the resin is preferably 1 part by mass or more per 100 parts by mass of the plate-like inorganic particles, from the viewpoint of improving the electrical insulation properties, especially from the viewpoint of particularly increasing the dielectric breakdown voltage. More preferably, it is 3 parts by mass or more, more preferably 5 parts by mass or more. From the viewpoint of improving thermal conductivity, it is preferably 40 parts by mass or less, more preferably 35 parts by mass or less, still more preferably 30 parts by mass or less. It is.

  The aspect ratio of the plate-like inorganic particles is preferably 1 or more, more preferably 10 or more, still more preferably 30 or more from the viewpoint of improving thermal conductivity, and when the adhesive resin and the plate-like inorganic particles are mixed. From the viewpoint of suppressing the increase in viscosity over time, it is preferably 100 or less, more preferably 90 or less, and still more preferably 80 or less.

The aspect ratio of the plate-like inorganic particles is a value obtained by dividing the maximum length in the plane direction of the plate-like inorganic particles by the maximum thickness of the plate-like inorganic particles. In other words, the aspect ratio of the plate-like inorganic particles is expressed by the formula:
[Aspect ratio of plate-like inorganic particles]
= [Maximum length of plate-like inorganic particles in the plane direction] / [Maximum thickness of plate-like inorganic particles]
Based on.

  The maximum length and the maximum thickness in the plane direction of the plate-like inorganic particles are determined by directly observing the plate-like inorganic particles with a scanning electron microscope or the like, and for each arbitrarily selected plate-like inorganic particle, the maximum length and the maximum thickness. The thickness can be measured and obtained as an average value in the measured number. The number of plate-like inorganic particles to be measured is not particularly limited, but is preferably about 10 to 20 from the viewpoint of improving accuracy and convenience of measurement. The maximum length and the maximum thickness of the plate-like inorganic particles contained in the heat-dissipating sheet layer are determined by measuring the plate-like inorganic particles separated by dissolving the heat-dissipating sheet layer with a solvent such as an organic solvent. Can be sought.

  In the present specification, the length and thickness in the plane direction of the plate-like inorganic particles mean the maximum length and the maximum thickness in the plane direction of one plate-like inorganic particle for convenience.

  The thickness of the plate-like inorganic particles is preferably 0.01 μm or more, more preferably 0.05 μm or more, and further preferably 0.1 μm or more from the viewpoint of improving thermal conductivity. From the viewpoint of suppressing thickening with time when the particles are mixed, it is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less.

  The length in the plane direction of the plate-like inorganic particles is preferably 0.1 μm or more, more preferably 0.2 μm or more from the viewpoint of improving thermal conductivity, and the adhesive resin and the plate-like inorganic particles are mixed. From the viewpoint of suppressing thickening with time, it is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less.

  Examples of the spherical inorganic particles include spherical inorganic particles made of a metal oxide such as silica, alumina, magnesium oxide, zinc oxide and titanium oxide; spherical inorganic particles made of a metal hydroxide such as aluminum hydroxide and magnesium hydroxide; Spherical inorganic particles made of metal nitride such as boron nitride, aluminum nitride, silicon nitride, silicon carbide; spherical inorganic particles made of metal carbide such as silicon carbide; spherical inorganic particles made of inorganic powder such as carbon black and graphite; sodium Metal particles composed of alkali metals such as potassium, alkaline earth metals such as magnesium and calcium, typical metals such as aluminum, zinc and tin, and transition metals such as iron, nickel, copper, manganese, silver and platinum However, the present invention is limited to only such examples. Not to. These spherical inorganic particles may be used alone or in combination of two or more. Among these spherical inorganic particles, alumina, magnesium oxide, aluminum hydroxide, magnesium hydroxide, aluminum nitride and silicon carbide are preferable.

  The average particle diameter of the inorganic filler is preferably 0.01 to 20 μm, more preferably 0.01 to 10 μm, from the viewpoint of improving the thermal conductivity of the heat dissipation sheet. In addition, the maximum particle size of the inorganic filler is preferably 0.01 to 20 μm, more preferably 0.01 to 10 μm, from the viewpoint of reducing the surface roughness Ra of the heat-dissipating sheet and improving thermal resistance and adhesiveness. More preferably, it is 0.01-7 micrometers. In addition, the average particle diameter and the maximum particle diameter of the inorganic filler are values when measured using a laser diffraction / scattering particle size distribution measuring apparatus [manufactured by Horiba, Ltd., product number: LA-920].

  The amount of the inorganic filler per 100 parts by mass of the nonvolatile content of the adhesive resin is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and further preferably 30 parts by mass from the viewpoint of improving the thermal conductivity of the heat dissipation sheet. From the viewpoint of improving the dispersion stability of the inorganic filler and the adhesiveness of the heat dissipation sheet, it is preferably 600 parts by mass or less, more preferably 550 parts by mass or less, further preferably 530 parts by mass or less, and still more preferably 520. The amount is at most 500 parts by mass, particularly preferably at most 500 parts by mass.

  As the curing agent, a compound having two or more functional groups capable of reacting with the crosslinkable group of the adhesive resin in one molecule can be used.

  Examples of the curing agent include a polyisocyanate curing agent, a polyfunctional epoxy curing agent, a silicone curing agent, and the like, but the present invention is not limited to such examples.

  Examples of the polyisocyanate curing agent include aromatic polyisocyanates such as xylylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, and tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and hydrogenated products of the above aromatic polyisocyanates. Aliphatic or cycloaliphatic polyisocyanates, dimers or trimers of these polyisocyanates, adducts composed of these polyisocyanates and polyols such as trimethylolpropane, and the like. It is not limited to illustration only. These polyisocyanate curing agents may be used alone or in combination of two or more.

  Polyisocyanate is, for example, Coronate L, Coronate L-55E, Coronate HX, Coronate HL, Coronate HL-S, Coronate 2234, Aquanate 200, Aquanate 210 [above, Nippon Polyurethane Industry Co., Ltd., Coronate and Aquanate Is a registered trademark], Death Module N3400 (manufactured by Sumitomo Bayer Urethane Co., Ltd. (now Bayer AG), Death Module is a registered trademark), Duranate D-201, Duranate TSE-100, Duranate TSS-100, Duranate 24A. -100, Duranate E-405-80T [above, manufactured by Asahi Kasei Chemicals Corporation, Duranate is a registered trademark], Takenate D-110N, Takenate D-120N, Takenate M-631N, MTERT-Olestar NP120 [Above, Mitsui Chemicals Co., Ltd., Takenate and I Star ®] can be readily commercially available as such. These polyisocyanates may be used alone or in combination of two or more.

  Examples of the polyfunctional epoxy curing agent include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, bisphenol A type epoxy resin, N, N, N ′, N′-tetra. Examples include glycidyl-m-xylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, N, N-diglycidylaniline, N, N-diglycidyltoluidine, etc. It is not limited to illustration only. These polyfunctional epoxy curing agents may be used alone or in combination of two or more.

  Examples of the silicone-based curing agent include Shin-Etsu Chemical Co., Ltd., product number: X-92-122, but the present invention is not limited to such examples. Only one type of silicone curing agent may be used, or two or more types may be used in combination.

  Among the curing agents, polyisocyanate dimers, polyisocyanate trimers, polyisocyanate bifunctional prepolymers and polyisocyanate adducts are preferred. Hexamethylene diisocyanate dimer, hexamethylene diisocyanate isocyanate. Nurate bodies (trimers) and tolylene diisocyanate adducts are more preferred, tolylene diisocyanate adducts are more preferred, and tolylene diisocyanate and trimethylolpropane adducts are even more preferred.

  The amount of the curing agent is usually preferably 0.01 to 1 equivalent, more preferably 0.05 to 0.8 equivalent, when the total amount of crosslinkable groups (functional groups) of the adhesive resin is 1 equivalent. It is. In addition, the amount of the curing agent (nonvolatile content) per 100 parts by mass of the nonvolatile content of the adhesive resin is preferably 0.3 parts by mass or more, more preferably 0.5 masses, from the viewpoint of suppressing cohesive failure of the heat dissipation sheet. From the viewpoint of improving the adhesiveness, it is preferably 5 parts by mass or less, more preferably 4 parts by mass or less, and still more preferably 3 parts by mass or less.

  Moreover, you may use a hardening accelerator in a suitable quantity for a thermal radiation material. Examples of the curing accelerator include dibutyltin dilaurate, tin octoate, dibutyltin di (2-ethylhexanoate), 2-ethylhexanoate lead, 2-ethylhexyl titanate, 2-ethylhexanoate iron, Examples include 2-ethylhexanoate cobalt, zinc naphthenate, cobalt naphthenate, tin octoate, bismuth octoate, tetra-n-butyltin, diisopropoxytitanium bis (ethylacetoacetate), and zirconium tetraacetylacetonate. The present invention is not limited to such examples. These curing accelerators may be used alone or in combination of two or more.

  The heat dissipating material preferably contains a tackifier. When an adhesive contains a tackifier, there exists an advantage that the punching workability of the heat-radiation sheet of this invention can be improved.

  Examples of tackifiers include rosin ester tackifiers and polymerized rosin ester tackifiers, but the present invention is not limited to such examples. These tackifiers may be used alone or in combination of two or more.

  The tackifier can be easily obtained commercially. Examples of tackifiers that can be easily obtained commercially include, for example, those manufactured by Harima Chemicals Co., Ltd., trade names: Hariestator DS-90, Hariestator DS-130, Hariestator AD-130, Arakawa Chemical Industries, Ltd. , Trade name: Super ester A-18, Super ester A-100, Super ester A-115, Super ester A-125 and other rosin ester tackifiers, manufactured by Maruzen Oil Chemicals Co., Ltd., trade name: PEDR- Polymeric rosin ester-based tackifiers such as 120M, manufactured by Arakawa Chemical Industry Co., Ltd., trade names: Pencel D-125, Pencel D-135, Pencel D-160, and the like are mentioned. It is not limited.

  The amount of the tackifier per 100 parts by mass of the nonvolatile content of the adhesive resin is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and further preferably 10 parts by mass or more, from the viewpoint of improving the punching processability. Still more preferably, it is 15 parts by mass or more, and from the viewpoint of improving the adhesiveness and heat and humidity resistance, it is preferably 95 parts by mass or less, more preferably 80 parts by mass or less, still more preferably 50 parts by mass or less, and even more preferably. Is 30 parts by mass or less.

  In addition, the heat dissipation material, as long as it does not impair the purpose of the present invention, if necessary, for example, plasticizer, adhesion imparting agent, dispersant, antioxidant, flame retardant, flame retardant aid, anti-settling agent, Additives such as thickeners, thixotropy imparting agents, surfactants, antifoaming agents, antistatic agents, surface treatment agents, antiaging agents, ultraviolet absorbers, and ultraviolet stabilizers may be contained in appropriate amounts.

  The plasticizer is preferably an aliphatic carboxylic acid ester, more preferably an esterified product of an aliphatic carboxylic acid having 2 to 20 carbon atoms, and the number of carbon atoms in the ester group, from the viewpoint of adapting the heat dissipation sheet to the adherend. Is more preferably an esterified product of an aliphatic carboxylic acid having an alkyl group of 2 to 20.

  Examples of the plasticizer include adipic acid ester, sebacic acid ester, azelaic acid ester, ricinoleic acid ester, maleic acid ester, itaconic acid ester, oleic acid ester, etc., but the present invention is limited to such examples only. It is not something. These plasticizers may be used alone or in combination of two or more. Among these plasticizers, adipic acid esters and sebacic acid esters are preferable, and diisononyl adipate and di-2-ethylhexyl sebacate are more preferable.

  Although the amount of the plasticizer is not particularly limited, it is usually 0.3 to 10 parts by mass per 100 parts by mass of the nonvolatile content of the adhesive resin from the viewpoint of imparting plasticity to the heat radiating sheet and improving the adhesiveness. Preferably there is.

  The adhesion-imparting agent has the property of improving the tackiness while maintaining the punching processability. The adhesion-imparting agent can be easily obtained commercially. Examples of the adhesion-imparting agent that can be easily obtained commercially include BYK-4512 manufactured by Big Chemie Japan Co., Ltd., but the present invention is limited to such examples. It is not a thing.

  The nonvolatile content in the heat dissipation material is preferably 20% by mass or more, more preferably 30% by mass or more from the viewpoint of improving productivity, and preferably 80% by mass or less, more preferably from the viewpoint of improving coating properties. Is 70% by mass or less. The nonvolatile content in the heat dissipation material can be adjusted by adjusting the amount of the solvent, the amount of the additive, and the like contained in the heat dissipation material. The solvent may be the same as the organic solvent used for the adhesive resin solution.

  The heat dissipation material can be easily prepared by mixing an adhesive resin, an inorganic filler, a curing agent, and other components as necessary. At this time, it is preferable to use an adhesive resin solution in which an adhesive resin is dissolved in an organic solvent from the viewpoint of preparing a heat dissipation material in which an inorganic filler or the like is uniformly dispersed.

  The organic solvent used for the adhesive resin solution is not particularly limited as long as it dissolves the adhesive resin. Examples of the organic solvent include gasoline, coal tar naphtha, petroleum ether, petroleum benzine, turonic acid, mineral spirit, and the like in addition to the organic solvent used when the monomer component is polymerized by a solution polymerization method. However, the present invention is not limited to such examples. The concentration of the nonvolatile content in the adhesive resin solution is not particularly limited, but is usually about 10 to 70% by mass.

  The heat radiating sheet of the present invention may be composed only of the heat radiating material, or the adhesive layer made of the heat radiating material may be formed on one surface or both surfaces of the base material, and is made of the heat radiating material. It may have an adhesive layer and a release liner, or it has a base material and a release liner, and an adhesive layer made of the heat dissipation material is formed between the base material and the release liner. Also good.

  Examples of the method for forming the adhesive layer (heat radiating material layer) from the heat radiating material include a method of applying the heat radiating material to the surface of the release liner or the base material, but the present invention is limited only to such examples. It is not a thing.

  As a method of applying the heat dissipation material to the release liner or the substrate, for example, a coating method using a knife coater, slot die coater, lip coater, roll coater, flow coater, spray coater, bar coater, comma coater, doctor blade, etc. Examples of the coating method include dipping and the like, but the present invention is not limited to such examples. When applying the heat-dissipating material to the substrate, the heat-dissipating material may be applied directly to the substrate, or after applying the heat-dissipating material to a release liner or the like, the coated material may be transferred onto the substrate. Thus, after apply | coating a heat radiating material to a base material, it can dry and can obtain the heat radiating sheet in which the adhesion layer (heat radiating material layer) was formed on the base material.

  Examples of the release liner include polyolefin resin films such as polyethylene and polypropylene, polyester resin films such as polyethylene terephthalate, polystyrene resin films, glassine paper, and the like, but the present invention is limited only to such examples. It is not a thing. In addition, when using a resin film as a peeling liner, resin processing, such as a silicone resin and a fluororesin, may be given.

  In general, the size and shape of the release liner are preferably adjusted so as to have a size and shape corresponding to the adhesive layer (heat dissipation material layer) formed on the heat dissipation sheet.

  Examples of the base material include paper such as fine paper, kraft paper, crepe paper, and glassine paper, resin base materials, textile products such as woven fabrics, non-woven fabrics, and fabrics, and conductive base materials. The invention is not limited to such examples. Among the base materials, since the heat dissipation sheet of the present invention can be suitably used for joining, for example, a wiring board and a heat sink, a member such as a housing that requires heat dissipation, a resin base material, Nonwoven fabrics and conductive substrates are preferred.

  Examples of the resin used for the resin substrate include polyolefin resins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polystyrene, polyvinyl chloride, cellophane, acrylic resin, polyimide, polyphenylene sulfide, and polyamide. However, the present invention is not limited to such examples. Examples of the resin substrate include a resin film and a sheet. The thickness of the resin film cannot be determined unconditionally because it varies depending on the use of the heat-dissipating sheet of the present invention, but is usually about 1 to 40 μm, and preferably 1 μm or more from the viewpoint of improving thermal conductivity. More preferably, it is 2 μm or more, more preferably 3 μm or more. From the viewpoint of improving electrical insulation and thermal conductivity, it is preferably 40 μm or less, more preferably 30 μm or less, still more preferably 20 μm or less, and even more preferably 10 μm. Hereinafter, it is still more preferably 5 μm or less.

Examples of the nonwoven fabric include a spunbond nonwoven fabric, a melt blown nonwoven fabric, and a needle punched nonwoven fabric. However, the present invention is not limited to such examples. Of these nonwoven fabrics, spunbond nonwoven fabrics are preferred. Examples of the fibers constituting the nonwoven fabric include polyolefin resins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, resins such as polystyrene, polyvinyl chloride, cellophane, acrylic resins, polyimide, polyphenylene sulfide, and polyamide. Synthetic fibers, regenerated fibers such as rayon and cupra, semisynthetic fibers such as acetate, and the like. However, the present invention is not limited to such examples. Although the thickness and basic weight of a nonwoven fabric are arbitrary, as an example, thickness is 3-50 micrometers and basic weight is 5-100 g / m < ² >. The thickness of the nonwoven fabric is preferably 3 μm or more, more preferably 5 μm or more, further preferably 7 μm or more from the viewpoint of improving electrical insulation and thermal conductivity, and preferably 50 μm from the viewpoint of improving electrical insulation. Below, it is more preferably 45 μm or less, still more preferably 40 μm or less. The basis weight of the nonwoven fabric is preferably 5 g / m ² or more, more preferably 10 g / m ² or more, and further preferably 15 g / m ² or more from the viewpoint of improving thermal conductivity. From the viewpoint of improving conductivity, it is preferably 100 g / m ² or less, more preferably 80 g / m ² or less, and still more preferably 60 g / m ² or less.

  Examples of conductive base materials include titanium foil, stainless steel foil, nickel foil, nickel-chromium alloy foil, copper foil, beryllium foil, aluminum foil, tin foil, lead foil, zinc foil, iron foil, molybdenum foil, and zirconium foil. , Gold foil, silver foil, platinum foil, metal foil such as palladium foil, graphite sheet, and the like can be mentioned, but the present invention is not limited to such examples. The thickness of the conductive substrate is arbitrary, but is usually about 1 to 40 μm. From the viewpoint of improving thermal conductivity, it is preferably 1 μm or more, more preferably 2 μm or more, and further preferably 3 μm or more. From the viewpoint of improving the flexibility of the heat dissipation sheet, it is preferably 40 μm or less, more preferably 30 μm or less, still more preferably 20 μm or less, still more preferably 10 μm or less, and even more preferably 5 μm or less.

  When using the base material for the heat dissipation sheet of the present invention, the adhesive layer may be formed by directly applying the heat dissipation material on the base material. After the heat dissipation material is applied to the release liner, the adhesive layer formed May be transferred to a substrate. When applying the heat dissipation material to one surface of the substrate, it is preferable to apply a release liner to the surface of the adhesive layer in order to protect the formed adhesive layer. Moreover, when apply | coating a thermal radiation material to both surfaces of a base material, in order to protect the adhesive layer formed, it is preferable to stick a release liner to the surface of the adhesive layer of the both surfaces of the said base material, respectively. In addition, when a base material is not used for the heat-dissipating sheet of the present invention, it is preferable to apply a heat-dissipating material to a release liner and protect the surface of the adhesive layer with another release liner having a different release force from the release liner. .

  The heat dissipation material is applied to a release liner or a substrate and then dried. Examples of the drying method include irradiation with hot air and far infrared rays.

  Thickness of the pressure-sensitive adhesive layer after drying of the heat-radiating sheet of the present invention [when the heat-radiating sheet of the present invention is composed only of the pressure-sensitive adhesive layer, the thickness of the heat-radiating sheet consisting of only the pressure-sensitive adhesive layer (the thickness of the release liner If the heat dissipation sheet of the present invention has a base material, the total thickness of the adhesive layer and the base material (not including the thickness of the release liner)] From the viewpoint of increasing the mechanical strength, it is 1 μm or more, preferably 3 μm or more, more preferably 5 μm or more. From the viewpoint of reducing the thermal resistance value of the heat dissipation sheet, it is 50 μm or less, preferably 40 μm or less, more preferably 30 μm or less. .

  The total thickness of the heat dissipation sheet of the present invention is obtained by adding the thickness of the release liner and / or the thickness of the base material to the thickness of the heat dissipation sheet not including the release liner and the base material. The total thickness of the heat dissipation sheet is preferably 1 to 600 μm, more preferably 1 to 500 μm, still more preferably 1 to 300 μm, still more preferably 1 to 200 μm, and still more preferably 1 to 600 μm, from the viewpoint of reducing thermal resistance. It is 100 μm, still more preferably 1 to 30 μm, particularly preferably 1 to 20 μm. Moreover, from the viewpoint of following the unevenness of the adherend, the overall thickness of the heat dissipation sheet is preferably 1 to 600 μm, more preferably 2 to 600 μm, and still more preferably 3 to 600 μm.

  The ratio between the maximum particle diameter of the inorganic filler and the thickness of the heat dissipation sheet (maximum particle diameter of the inorganic filler / thickness of the heat dissipation sheet) reduces the surface roughness Ra of the adhesive layer of the heat dissipation sheet and increases the thermal resistance. From the viewpoint of improving, it is preferably 0.1 to 1.0, more preferably 0.1 to 0.9, still more preferably 0.1 to 0.8, and still more preferably 0.1 to 0.7. . The surface roughness Ra of the adhesive layer is preferably 0.01 μm or more, more preferably 0.03 μm, from the viewpoint of suppressing thermal resistance when the heat dissipation sheet of the present invention is mounted between the heat generator and the heat dissipator. As described above, the thickness is more preferably 0.05 μm or more, and preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less, from the viewpoint of suppressing the formation of an air layer between the heating element and the heat radiating body.

  The heat dissipation sheet of the present invention may have a structure in which one surface is protected by a single release liner (single separator type), and both surfaces are protected by two release liners, respectively. (Double separator type) may be used.

  In the heat release sheet of the single separator type, it is preferable that the peelability is different between the front surface and the back surface of the heat release sheet. Moreover, in the double separator type heat dissipation sheet, it is preferable that the release liners attached to the front and back surfaces have different release forces. In the double separator type heat dissipation sheet, for example, a release liner made of a resin film and a release liner made of paper can be used as the release liner. The heat-dissipating sheet protected by these release liners does not peel off at the interface with the adhesive layer, but peels off when the adhesive layer is attached (so-called “crying phenomenon”). Suppresses the phenomenon that the release sheet peels off when the release liner is peeled off from the heat dissipation sheet after sticking, the phenomenon that the release sheet peels off, the occurrence of wrinkling and twisting of the adhesive layer, the lifting of the release liner, etc. be able to.

  Examples of the form of the heat dissipation sheet of the present invention include a tape form and a sheet form, but the present invention is not limited only to such form. When the heat dissipation sheet of the present invention has a tape shape, it may be wound in a roll shape. Moreover, when the heat dissipation sheet of the present invention has a sheet shape, the sheet-shaped heat dissipation sheet may be laminated. When a single separator type heat dissipation sheet is wound in a roll shape, a release treatment layer is formed on both sides as a release liner so that the release liner and the adhesive layer can be easily released. It is preferable to use a release liner.

  The heat-dissipating sheet of the present invention obtained as described above is generally excellent in thermal conductivity, thermal resistance, adhesiveness, and heat and humidity resistance even when the adhesive layer is thin. It can be suitably used when joining a wiring board and a member such as a heat sink or a case that requires heat dissipation.

  EXAMPLES Next, although this invention is demonstrated further in detail based on an Example, this invention is not limited only to this Example.

Production Example 1
In a reaction vessel equipped with a cooling pipe, a nitrogen gas introduction pipe, a thermometer, a dropping funnel and a stirrer, 100 parts of ethyl acetate (mass part, the same shall apply hereinafter), 22.7 parts of n-butyl acrylate, 70 parts of 2-ethylhexyl acrylate. 0 parts, 2.0 parts of acrylic acid, 0.3 parts of hydroxyethyl acrylate and 5.0 parts of vinyl acetate, and then 0.1 part of azoisobutyronitrile were added at 80 ° C. in a nitrogen gas atmosphere. By reacting for 5 hours, a solution of adhesive resin A was obtained (non-volatile content: 50% by mass). The obtained adhesive resin A had a weight average molecular weight of 600,000 and a glass transition temperature of −60.8 ° C.

Production Example 2
In a reaction vessel equipped with a cooling pipe, a nitrogen gas introduction pipe, a thermometer, a dropping funnel and a stirrer, 100 parts of ethyl acetate, 22.7 parts of butyl acrylate, 70.0 parts of 2-ethylhexyl acrylate, N-vinylpyrrolidone 0 parts, 0.3 parts of hydroxyethyl acrylate and 4.0 parts of vinyl acetate were added, then 0.1 part of azoisobutyronitrile was added and reacted at 80 ° C. for 5 hours in a nitrogen gas atmosphere. A solution of adhesive resin B was obtained (non-volatile content: 50% by mass). The obtained adhesive resin B had a weight average molecular weight of 600,000 and a glass transition temperature of 60.0 ° C.

Production Example 3
In a reaction vessel equipped with a cooling pipe, a nitrogen gas introduction pipe, a thermometer, a dropping funnel and a stirrer, 100 parts of ethyl acetate, 22.7 parts of butyl acrylate, 70.0 parts of 2-ethylhexyl acrylate, 2.0 parts of acrylic acid After adding 0.3 parts of hydroxyethyl acrylate and 5.0 parts of vinyl acetate, 0.2 parts of azoisobutyronitrile was added and reacted at 80 ° C. for 5 hours in a nitrogen gas atmosphere. A solution of Resin C was obtained. The obtained adhesive resin C had a weight average molecular weight of 300,000 and a glass transition temperature of −60.8 ° C.

Production Example 4
In a reaction vessel equipped with a cooling pipe, a nitrogen gas introduction pipe, a thermometer, a dropping funnel and a stirrer, 100 parts of ethyl acetate, 22.7 parts of butyl acrylate, 70.0 parts of 2-ethylhexyl acrylate, N-vinylpyrrolidone After adding 0 part, 0.3 part of hydroxyethyl acrylate and 4.0 part of vinyl acetate, 0.2 part of azoisobutyronitrile was added and reacted at 80 ° C. for 5 hours in a nitrogen gas atmosphere. A solution of adhesive resin D was obtained. The resulting adhesive resin D had a weight average molecular weight of 300,000 and a glass transition temperature of 60.0 ° C.

Production Example 5
In a reaction vessel equipped with a cooling pipe, a nitrogen gas introduction pipe, a thermometer, a dropping funnel and a stirrer, 100 parts of ethyl acetate, 22.7 parts of butyl acrylate, 70.0 parts of 2-ethylhexyl acrylate, 0.3 parts of hydroxyethyl acrylate Parts, 5.0 parts of vinyl acetate and 2.0 parts of 2-isopropenyl-2-oxazoline, then 0.1 parts of azoisobutyronitrile and reaction at 80 ° C. for 5 hours in a nitrogen gas atmosphere By doing so, a solution of adhesive resin E was obtained. The obtained adhesive resin E had a weight average molecular weight of 500,000 and a glass transition temperature of −60.9 ° C.

Production Example 6
In a reaction vessel equipped with a cooling pipe, a nitrogen gas introduction pipe, a thermometer, a dropping funnel and a stirrer, 100 parts of ethyl acetate, 22.7 parts of butyl acrylate, 70.0 parts of 2-ethylhexyl acrylate, 0.3 parts of hydroxyethyl acrylate 1 part, 5.0 parts of vinyl acetate and 2.0 parts of methyl allyloxymethyl acrylate, and then 0.1 part of azoisobutyronitrile are allowed to react at 80 ° C. for 5 hours in a nitrogen gas atmosphere. Thus, a solution of the adhesive resin F was obtained. The obtained adhesive resin F had a weight average molecular weight of 500,000 and a glass transition temperature of −61.0 ° C.

Example 1
The solution of adhesive resin A and spherical alumina particles were mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of adhesive resin A obtained in Production Example 1 was 200 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner [manufactured by Sanei Kaken Co., Ltd., product number: K-80HS] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 10 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 2
The solution of the adhesive resin B and the spherical alumina particles are mixed so that the amount of spherical alumina particles (maximum particle diameter: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin B obtained in Production Example 2 is 200 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin B becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner [manufactured by Sanei Kaken Co., Ltd., product number: K-80HS] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 10 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 3
The solution of the adhesive resin C and the spherical alumina particles are mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin C obtained in Production Example 3 is 200 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin C becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 5 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 4
The solution of the adhesive resin D and the spherical alumina particles are mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin D obtained in Production Example 4 is 200 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin D becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 5 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 5
The amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of nonvolatile content of the adhesive resin A obtained in Production Example 1 is 100 parts, and the amount of plate-like boron nitride (maximum particle size: 4 μm) is 15 parts. After mixing the adhesive resin A solution, spherical alumina particles, plate-like boron nitride and spherical aluminum hydroxide particles so that the amount of spherical aluminum hydroxide particles (maximum particle size: 5 μm) is 100 parts, Ethyl acetate was added so that the content ratio of was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 15 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 6
The amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin B obtained in Production Example 2 is 100 parts, and the amount of plate-like boron nitride particles (maximum particle size: 4 μm) is 15. Part, after mixing the solution of adhesive resin B, spherical alumina particles, plate-like boron nitride particles and spherical aluminum hydroxide particles so that the amount of spherical aluminum hydroxide particles (maximum particle size: 5 μm) is 100 parts, Ethyl acetate was added so that the non-volatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin B becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 15 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 7
The solution of the adhesive resin C and the spherical alumina particles are mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin C obtained in Production Example 3 is 400 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin C becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 20 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.3 μm.

Example 8
The solution of the adhesive resin C and the spherical alumina particles were mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin C obtained in Production Example 3 was 100 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin C becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner [manufactured by Sanei Kaken Co., Ltd., product number: K-80HS] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 10 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.3 μm.

Example 9
The solution of the adhesive resin C and the spherical alumina particles were mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin C obtained in Production Example 3 was 50 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin C becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 5 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 10
The solution of the adhesive resin C and the spherical alumina particles are mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin C obtained in Production Example 3 is 200 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin C becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 30 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 11
The solution of the adhesive resin D and the spherical alumina particles are mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin D obtained in Production Example 4 is 200 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin D becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 30 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 12
The amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of nonvolatile content of the adhesive resin C obtained in Production Example 3 was 250 parts, and the amount of plate-like boron nitride particles (maximum particle size: 4 μm) was 50. After mixing the adhesive resin C solution, spherical alumina particles and plate-like boron nitride particles so as to be part, add ethyl acetate so that the content of non-volatile content is 50% by mass, and sufficiently stir Thus, a mixed solution was obtained.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin C becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat-dissipating material obtained above is applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying is about 4 μm. A heat-dissipating sheet A having an adhesive layer was obtained. Further, the heat-dissipating material obtained above was applied onto a release liner [manufactured by Toyobo Co., Ltd., product number: E-7006] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about A heat radiating sheet B having a 4 μm adhesive layer was obtained.

  Next, the heat radiating sheet A and the heat radiating sheet B obtained above are respectively transferred to both surfaces of a polyethylene terephthalate film (thickness: 2 μm) and cured at 40 ° C. for 2 days, thereby forming polyethylene as a base material (core material). A heat dissipation sheet having a terephthalate film and having an overall thickness of about 10 μm was obtained. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling each release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.1 μm.

Example 13
The amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of nonvolatile content of the adhesive resin C obtained in Production Example 3 is 150 parts, and the amount of plate-like boron nitride particles (maximum particle size: 4 μm) is 50. After mixing the adhesive resin C solution, spherical alumina particles and plate-like boron nitride particles so as to be part, add ethyl acetate so that the content of non-volatile content is 50% by mass, and sufficiently stir Thus, a mixed solution was obtained.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin C becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner [manufactured by Sanei Kaken Co., Ltd., product number: K-80HS] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 2 A heat-dissipating sheet A having an adhesive layer of 5 μm was obtained. Further, the heat-dissipating material obtained above was applied onto a release liner [manufactured by Toyobo Co., Ltd., product number: E-7006] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about A heat-dissipating sheet B having an adhesive layer of 2.5 μm was obtained.

  Next, the heat radiating sheet A and the heat radiating sheet B obtained above are respectively transferred to both surfaces of an aluminum foil (thickness: 5 μm) and cured at 40 ° C. for 2 days, thereby forming an aluminum foil as a base material (core material). A heat radiating sheet having a total thickness of about 10 μm was obtained. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling each release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.1 μm.

Example 14
The amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of nonvolatile content of the adhesive resin C obtained in Production Example 3 is 150 parts, and the amount of plate-like boron nitride particles (maximum particle size: 4 μm) is 50. After mixing the adhesive resin C solution, spherical alumina particles and plate-like boron nitride particles so as to be part, add ethyl acetate so that the content of non-volatile content is 50% by mass, and sufficiently stir Thus, a mixed solution was obtained.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin C becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 5 μm. A heat-dissipating sheet A having an adhesive layer was obtained. Further, the heat-dissipating material obtained above was applied onto a release liner [manufactured by Toyobo Co., Ltd., product number: E-7006] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about A heat-dissipating sheet B having a 5 μm adhesive layer was obtained.

  Next, the heat-dissipating sheet A and the heat-dissipating sheet B obtained above are respectively transferred to both surfaces of a graphite sheet (thickness: 10 μm) and cured at 40 ° C. for 2 days, whereby a graphite sheet is used as a base material (core material). A heat radiating sheet having a total thickness of about 20 μm was obtained. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling each release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.1 μm.

Example 15
The amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of nonvolatile content of the adhesive resin B obtained in Production Example 2 is 100 parts, and the amount of spherical aluminum hydroxide particles (maximum particle size: 5 μm) is 100. After mixing the solution of adhesive resin B, spherical alumina particles, spherical aluminum hydroxide particles and plate-like graphite particles so that the amount of parts and plate-like graphite particles (maximum particle size: 5 μm) is 30 parts, Ethyl acetate was added so that the content ratio of was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin B becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner [manufactured by Sanei Kaken Co., Ltd., product number: K-80HS] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 2 A heat-dissipating sheet A having an adhesive layer of 5 μm was obtained. Further, the heat-dissipating material obtained above was applied onto a release liner [manufactured by Toyobo Co., Ltd., product number: E-7006] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about A heat-dissipating sheet B having an adhesive layer of 2.5 μm was obtained.

  Next, the heat radiating sheet A and the heat radiating sheet B obtained above are respectively transferred to both surfaces of an aluminum foil (thickness: 5 μm) and cured at 40 ° C. for 2 days, thereby forming an aluminum foil as a base material (core material). A heat radiating sheet having a total thickness of about 10 μm was obtained. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling each release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.1 μm.

Example 16
The amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of nonvolatile content of the adhesive resin B obtained in Production Example 2 is 100 parts, and the amount of spherical aluminum hydroxide particles (maximum particle size: 5 μm) is 100. After mixing the solution of adhesive resin B, spherical alumina particles, spherical aluminum hydroxide particles and plate-like graphite particles so that the amount of parts and plate-like graphite particles (maximum particle size: 5 μm) is 100 parts, Ethyl acetate was added so that the content ratio of was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin B becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 5 μm. A heat-dissipating sheet A having an adhesive layer was obtained. Further, the heat-dissipating material obtained above was applied onto a release liner [manufactured by Toyobo Co., Ltd., product number: E-7006] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about A heat-dissipating sheet B having a 5 μm adhesive layer was obtained.

  Next, the heat-dissipating sheet A and the heat-dissipating sheet B obtained above are respectively transferred to both surfaces of a graphite sheet (thickness: 10 μm) and cured at 40 ° C. for 2 days, whereby a graphite sheet is used as a base material (core material). A heat radiating sheet having a total thickness of about 20 μm was obtained. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling each release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.1 μm.

Example 17
The solution of adhesive resin A and spherical alumina particles were mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of adhesive resin A obtained in Production Example 1 was 200 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A is 2 parts (nonvolatile content), Sebacin A heat dissipation material was obtained by mixing the mixed solution obtained above, the curing agent, and di-2-ethylhexyl sebacate so that the amount of di-2-ethylhexyl acid was 3 parts.

  The heat dissipation material obtained above was applied onto a release liner [manufactured by Sanei Kaken Co., Ltd., product number: K-80HS] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 10 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.05 μm.

Example 18
The solution of the adhesive resin B and the spherical alumina particles are mixed so that the amount of spherical alumina particles (maximum particle diameter: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin B obtained in Production Example 2 is 200 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin B is 2 parts (nonvolatile content), Sebacin A heat dissipation material was obtained by mixing the mixed solution obtained above, the curing agent, and di-2-ethylhexyl sebacate so that the amount of di-2-ethylhexyl acid was 3 parts.

  The heat dissipation material obtained above was applied onto a release liner [manufactured by Sanei Kaken Co., Ltd., product number: K-80HS] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 10 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.05 μm.

Example 19
The solution of the adhesive resin C and the spherical alumina particles were mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin C obtained in Production Example 3 was 200 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin C becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 50 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 20
The solution of the adhesive resin D and the spherical alumina particles are mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin D obtained in Production Example 4 is 200 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin D becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 50 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 21
The amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin A obtained in Production Example 1 is 100 parts, and the amount of spherical aluminum hydroxide particles (maximum particle size: 5 μm) is 100. After mixing the adhesive resin A solution, spherical alumina particles, and spherical aluminum hydroxide particles so as to be part, add ethyl acetate so that the content of non-volatile content is 50% by mass, and sufficiently stir Thus, a mixed solution was obtained.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A is 2 parts (nonvolatile content), adipine A heat dissipation material was obtained by mixing the mixed solution obtained above, the curing agent, and diisononyl adipate so that the amount of diisononyl acid was 3 parts.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 15 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.05 μm.

Example 22
The amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of nonvolatile content of the adhesive resin B obtained in Production Example 2 is 100 parts, and the amount of spherical aluminum hydroxide particles (maximum particle size: 5 μm) is 100. After mixing the adhesive resin B solution, spherical alumina particles and spherical aluminum hydroxide particles so as to be part, add ethyl acetate so that the content of non-volatile content is 50% by mass, and sufficiently stir Thus, a mixed solution was obtained.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin B is 2 parts (nonvolatile content), adipine A heat dissipation material was obtained by mixing the mixed solution obtained above, the curing agent, and diisononyl adipate so that the amount of diisononyl acid was 3 parts.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 15 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.05 μm.

Example 23
The amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of nonvolatile content of the adhesive resin C obtained in Production Example 3 was 250 parts, and the amount of plate-like boron nitride particles (maximum particle size: 4 μm) was 50. After mixing the adhesive resin C solution, spherical alumina particles and plate-like boron nitride particles so as to be part, add ethyl acetate so that the content of non-volatile content is 50% by mass, and sufficiently stir Thus, a mixed solution was obtained.

  Next, the amount of a curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin C is 2 parts (nonvolatile content), adipine A heat dissipation material was obtained by mixing the mixed solution obtained above, the curing agent, and diisononyl adipate so that the amount of diisononyl acid was 3 parts.

  The heat-dissipating material obtained above is applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying is about 4 μm. A heat-dissipating sheet A having an adhesive layer was obtained. Further, the heat-dissipating material obtained above was applied onto a release liner [manufactured by Toyobo Co., Ltd., product number: E-7006] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about A heat radiating sheet B having a 4 μm adhesive layer was obtained.

  Next, the heat radiating sheet A and the heat radiating sheet B obtained above are respectively transferred to both surfaces of a polyethylene terephthalate film (thickness: 2 μm) and cured at 40 ° C. for 2 days, thereby forming polyethylene as a base material (core material). A heat dissipation sheet having a terephthalate film and having an overall thickness of about 10 μm was obtained. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling each release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.05 μm.

Example 24
The amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of nonvolatile content of the adhesive resin C obtained in Production Example 3 is 150 parts, and the amount of plate-like boron nitride particles (maximum particle size: 4 μm) is 50. After mixing the solution of adhesive resin C, spherical alumina particles and plate-like boron nitride so as to be part, ethyl acetate is added so that the content of non-volatile content is 50% by mass, and sufficiently stirred A mixed solution was obtained.

  Next, the amount of a curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin C is 2 parts (nonvolatile content), adipine A heat dissipation material was obtained by mixing the mixed solution obtained above, the curing agent, and diisononyl adipate so that the amount of diisononyl acid was 3 parts.

  The heat dissipation material obtained above was applied onto a release liner [manufactured by Sanei Kaken Co., Ltd., product number: K-80HS] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 2 A heat-dissipating sheet A having an adhesive layer of 5 μm was obtained. Further, the heat-dissipating material obtained above was applied onto a release liner [manufactured by Toyobo Co., Ltd., product number: E-7006] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about A heat-dissipating sheet B having an adhesive layer of 2.5 μm was obtained.

  Next, the heat radiating sheet A and the heat radiating sheet B obtained above are respectively transferred to both surfaces of an aluminum foil (thickness: 5 μm) and cured at 40 ° C. for 2 days, thereby forming an aluminum foil as a base material (core material). A heat radiating sheet having a total thickness of about 10 μm was obtained. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling each release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.05 μm.

Example 25
The amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of nonvolatile content of the adhesive resin C obtained in Production Example 3 is 150 parts, and the amount of plate-like boron nitride particles (maximum particle size: 4 μm) is 50. After mixing the adhesive resin C solution, spherical alumina particles and plate-like boron nitride particles so as to be part, add ethyl acetate so that the content of non-volatile content is 50% by mass, and sufficiently stir Thus, a mixed solution was obtained.

  Next, the amount of a curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin C is 2 parts (nonvolatile content), adipine A heat dissipation material was obtained by mixing the mixed solution obtained above, the curing agent, and diisononyl adipate so that the amount of diisononyl acid was 3 parts.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 5 μm. A heat-dissipating sheet A having an adhesive layer was obtained. Further, the heat-dissipating material obtained above was applied onto a release liner [manufactured by Toyobo Co., Ltd., product number: E-7006] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about A heat-dissipating sheet B having a 5 μm adhesive layer was obtained.

  Next, the heat-dissipating sheet A and the heat-dissipating sheet B obtained above are respectively transferred to both surfaces of a graphite sheet (thickness: 10 μm) and cured at 40 ° C. for 2 days, whereby a graphite sheet is used as a base material (core material). A heat radiating sheet having a total thickness of about 20 μm was obtained. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling each release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.05 μm.

Example 26
The amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of nonvolatile content of the adhesive resin B obtained in Production Example 2 is 100 parts, and the amount of spherical aluminum hydroxide particles (maximum particle size: 5 μm) is 100. After mixing the solution of adhesive resin B, spherical alumina particles, spherical aluminum hydroxide particles and plate-like graphite particles so that the amount of parts and plate-like graphite particles (maximum particle size: 5 μm) is 30 parts, Ethyl acetate was added so that the content ratio of was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin B is 2 parts (nonvolatile content), adipine A heat dissipation material was obtained by mixing the mixed solution obtained above, the curing agent, and diisononyl adipate so that the amount of diisononyl acid was 5 parts.

  The heat dissipation material obtained above was applied onto a release liner [manufactured by Sanei Kaken Co., Ltd., product number: K-80HS] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 2 A heat-dissipating sheet A having an adhesive layer of 5 μm was obtained. Further, the heat-dissipating material obtained above was applied onto a release liner [manufactured by Toyobo Co., Ltd., product number: E-7006] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about A heat-dissipating sheet B having an adhesive layer of 2.5 μm was obtained.

  Next, the heat radiating sheet A and the heat radiating sheet B obtained above are respectively transferred to both surfaces of an aluminum foil (thickness: 5 μm) and cured at 40 ° C. for 2 days, thereby forming an aluminum foil as a base material (core material). A heat radiating sheet having a total thickness of about 10 μm was obtained. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling each release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.05 μm.

Example 27
The amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of nonvolatile content of the adhesive resin B obtained in Production Example 2 is 100 parts, and the amount of spherical aluminum hydroxide particles (maximum particle size: 5 μm) is 100. After mixing the solution of adhesive resin B, spherical alumina particles, spherical aluminum hydroxide particles and plate-like graphite particles so that the amount of parts and plate-like graphite particles (maximum particle size: 5 μm) is 100 parts, Ethyl acetate was added so that the content ratio of was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin B is 2 parts (nonvolatile content), adipine A heat dissipation material was obtained by mixing the mixed solution obtained above, the curing agent, and diisononyl adipate so that the amount of diisononyl acid was 5 parts.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 5 μm. A heat-dissipating sheet A having an adhesive layer was obtained. Further, the heat-dissipating material obtained above was applied onto a release liner [manufactured by Toyobo Co., Ltd., product number: E-7006] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about A heat-dissipating sheet B having a 5 μm adhesive layer was obtained.

  Next, the heat-dissipating sheet A and the heat-dissipating sheet B obtained above are respectively transferred to both surfaces of a graphite sheet (thickness: 10 μm) and cured at 40 ° C. for 2 days, whereby a graphite sheet is used as a base material (core material). A heat radiating sheet having a total thickness of about 20 μm was obtained. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling each release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.05 μm.

Example 28
The solution of the adhesive resin E and the spherical alumina particles were mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin E obtained in Production Example 5 was 150 parts. Then, ethyl acetate was added so that the content rate of a non volatile matter might be 50 mass%, and the mixed solution was obtained by fully stirring.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin E becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 15 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.1 μm.

Example 29
The solution of the adhesive resin F and the spherical alumina particles were mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin F obtained in Production Example 6 was 150 parts. Then, ethyl acetate was added so that the content rate of a non volatile matter might be 50 mass%, and the mixed solution was obtained by fully stirring.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin F becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 15 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.1 μm.

Comparative Example 1
The solution of adhesive resin A and spherical alumina particles were mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of adhesive resin A obtained in Production Example 1 was 200 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat radiation material obtained above is applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying is about 80 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Comparative Example 2
The solution of the adhesive resin A and the spherical alumina particles were mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin A obtained in Production Example 1 was 800 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat radiation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) so that the thickness after drying was about 20 μm, and dried in an atmosphere at 100 ° C. for 5 minutes. However, since the formed coating film was brittle, its physical properties could not be measured.

Comparative Example 3
The solution of adhesive resin A and spherical alumina particles were mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of adhesive resin A obtained in Production Example 1 was 200 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A becomes 10 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat radiation material obtained above is applied onto a release liner [manufactured by Sanei Kaken Co., Ltd., product number: K-80HS] and dried in an atmosphere at 100 ° C. for 5 minutes, whereby the thickness of the adhesive layer is about 20 μm. The heat radiating sheet was obtained, but this heat radiating sheet had no tack and was not sticky.

Comparative Example 4
The solution of the adhesive resin A and the spherical alumina particles were mixed so that the amount of spherical alumina particles (maximum particle size: 5 μm) per 100 parts of the nonvolatile content of the adhesive resin A obtained in Production Example 1 was 200 parts. Then, ethyl acetate was added so that the content rate of a non volatile matter might be 50 mass%, and the mixed solution was obtained by fully stirring.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A is 0.1 part (nonvolatile content). The heat dissipation material was obtained by mixing the mixed solution obtained above and the curing agent so as to be.

  The heat radiation material obtained above is applied onto a release liner [manufactured by Sanei Kaken Co., Ltd., product number: K-80HS] and dried in an atmosphere at 100 ° C. for 5 minutes, whereby the thickness of the adhesive layer is about 20 μm. The heat dissipation sheet was obtained. Since this heat-dissipating sheet caused cohesive failure when measuring adhesive strength, measurement of its physical properties was stopped.

Comparative Example 5
Ethyl acetate was added so that the content of the nonvolatile content of the adhesive resin A obtained in Production Example 1 was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A becomes 1 part (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner [manufactured by Sanei Kaken Co., Ltd., product number: K-80HS] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 10 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.05 μm.

Comparative Example 6
Ethyl acetate was added to 100 parts of the nonvolatile content of the adhesive resin A obtained in Production Example 1 so that the content of the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A becomes 1 part (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat-dissipating material obtained above is applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying is about 4 μm. A heat-dissipating sheet A having an adhesive layer was obtained. Further, the heat-dissipating material obtained above was applied onto a release liner [manufactured by Toyobo Co., Ltd., product number: E-7006] and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about A heat radiating sheet B having a 4 μm adhesive layer was obtained.

  Next, the heat radiating sheet A and the heat radiating sheet B obtained above are respectively transferred to both surfaces of a polyethylene terephthalate film (thickness: 2 μm) and cured at 40 ° C. for 2 days, thereby forming polyethylene as a base material (core material). A heat dissipation sheet having a terephthalate film and having an overall thickness of about 10 μm was obtained. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling each release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.03 μm.

  Next, the following physical properties were examined using the heat dissipation sheet obtained in each example or each comparative example. The results are shown in Table 1.

(Thermal conductivity)
The thermal diffusivity of the heat-dissipating sheet was measured using a thermal diffusivity / thermal conductivity measuring device [trade name: ai-phase mobile 1 manufactured by Hitachi High-Technologies Corporation]. The specific heat of the heat radiating sheet was measured using a differential scanning calorimeter [manufactured by Seiko Instruments Inc., product number: DSC220C]. Moreover, the specific gravity of the heat radiating sheet was obtained by cutting the heat radiating sheet into a size of 50 mm in length and 50 mm in width and measuring the mass of the obtained test piece.

Next, the thermal conductivity (hereinafter also referred to as “initial thermal conductivity”) is expressed by the formula:
[Thermal conductivity] = [thermal diffusivity] x [specific heat] x [specific gravity]
The thermal conductivity of the heat dissipation sheet was evaluated based on the following evaluation criteria.
[Evaluation criteria]
30: Thermal conductivity is 2 W / mK or more 20: Thermal conductivity is 1 W / mK or more and less than 2 W / mK 10: Thermal conductivity is 0.3 W / mK or more and less than 1 W / mK 0: Thermal conductivity is 0.3 W / m <mK

[Thermal resistance]
Using a thermal resistance measuring device (trade name: Resin material thermal resistance measuring device manufactured by Hitachi Technology & Service Co., Ltd.), the thermal resistance of the heat radiating sheet is measured in a constant load mode, and based on the following evaluation criteria The thermal resistance of was evaluated.
[Evaluation criteria]
30: Thermal resistance of the heat dissipation sheet is less than 0.10 × 10 ⁻⁴ m ² · K / W 20: Thermal resistance of the heat dissipation sheet is 0.10 × 10 ⁻⁴ m ² · K / W or more 0.5 × 10 ⁻ Less than ⁴ m ² · K / W 10: Thermal resistance of heat dissipation sheet is 0.50 × 10 ^-4 m ² · K / W or more

[Adhesiveness]
A test piece was prepared by peeling off one side of a release liner of a heat dissipation sheet having a length of 50 mm and a width of 25 mm, and backing a polyethylene terephthalate film (thickness: 25 μm).

  The other release liner of the test piece obtained above was peeled off, the adhesive surface was attached to an aluminum plate (thickness: 1 mm), pressure-pressed with a roller having a mass of 2 kg, and left for 1 hour. The film was peeled from the aluminum plate at a peeling rate of 300 mm / min in the direction of 180 °, the adhesive strength at that time was measured, and the tackiness was evaluated based on the following evaluation criteria.

The preparation of the test piece and the peeling test were both performed in an atmosphere at a temperature of 23 ° C. and a relative humidity of 65%.
[Evaluation criteria]
30: Adhesive strength is 5 N / 25 mm or more 20: Adhesive strength is 1 N / 25 mm or more and less than 5 N / 25 mm 10: Adhesive force is less than 1 N / 25 mm

[Moisture and heat resistance]
The heat dissipation sheet is placed in an atmosphere at a temperature of 85 ° C. and a relative humidity of 85%, and after 2000 hours, the thermal conductivity is the same as the above “thermal conductivity” (hereinafter referred to as the thermal conductivity after the wet heat test). Find the formula:
[Change rate of thermal conductivity]
= [| Thermal conductivity after wet heat test-Initial thermal conductivity |]
÷ [Initial thermal conductivity] x 100
Based on the above, the rate of change in thermal conductivity was determined, and the resistance to moist heat was evaluated based on the following evaluation criteria.
[Evaluation criteria]
30: Change rate of thermal conductivity is within 20% 20: Change rate of thermal conductivity is 20% or more and less than 30% 10: Change rate of thermal conductivity is 30% or more and less than 40% 0: Change rate of thermal conductivity Measurement is not possible (deterioration such as cracking of the coating occurs)

  From the results shown in Table 1, the overall evaluation is 90 points or less in the heat dissipation sheet obtained in each comparative example, whereas the overall evaluation is 100 points in the heat dissipation sheet obtained in each example. From the above, it can be seen that the heat conductivity, heat resistance, adhesiveness, and heat and humidity resistance are excellent overall.

Example 30
The amount of spherical alumina particles (maximum particle size: 12 μm) per 100 parts of the nonvolatile content of the adhesive resin A obtained in Production Example 1 is 220 parts, a tackifier [trade name: Pencel, manufactured by Arakawa Chemical Industries, Ltd. D-135] After mixing the solution of adhesive resin A, spherical alumina particles and tackifier so as to be 25 parts, ethyl acetate was added so that the nonvolatile content was 50% by mass, To obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 12 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 31
The amount of spherical alumina particles (maximum particle size: 12 μm) per 100 parts of the non-volatile content of the adhesive resin B obtained in Production Example 1 is 200 parts, tackifier [trade name: Pencel, manufactured by Arakawa Chemical Industries, Ltd. D-135] After mixing the solution of adhesive resin B, spherical alumina particles, and tackifier so as to be 20 parts, ethyl acetate was added so that the nonvolatile content was 50% by mass. To obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin B becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 12 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 32
The amount of spherical alumina particles (maximum particle size: 12 μm) per 100 parts of the nonvolatile content of the adhesive resin C obtained in Production Example 1 is 220 parts, a tackifier [trade name: Pencel, manufactured by Arakawa Chemical Industries, Ltd. D-135] After mixing the solution of adhesive resin C, spherical alumina particles, and tackifier so as to be 30 parts, ethyl acetate was added so that the nonvolatile content was 50% by mass, To obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin C becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 12 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 33
The amount of spherical alumina particles (maximum particle size: 12 μm) per 100 parts of nonvolatile content of the adhesive resin D obtained in Production Example 1 is 180 parts, a tackifier [trade name: Pencel, manufactured by Arakawa Chemical Industries, Ltd. D-135] After mixing the solution of adhesive resin D, spherical alumina particles, and tackifier so as to be 15 parts, ethyl acetate was added so that the nonvolatile content was 50% by mass, To obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin D becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 12 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 34
The amount of spherical alumina particles (maximum particle size: 12 μm) per 100 parts of the non-volatile content of the adhesive resin A obtained in Production Example 1 is 200 parts, tackifier [trade name: Pencel, manufactured by Arakawa Chemical Industries, Ltd. D-160] After mixing the solution of adhesive resin A, spherical alumina particles, and tackifier so as to be 20 parts, ethyl acetate was added so that the nonvolatile content was 50% by mass, To obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 15 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 35
The amount of spherical alumina particles (maximum particle size: 12 μm) per 100 parts of the non-volatile content of the adhesive resin A obtained in Production Example 1 is 200 parts, tackifier [trade name: Super manufactured by Arakawa Chemical Industries, Ltd. Ester A-18] After mixing a solution of adhesive resin A, spherical alumina particles, and a tackifier so as to be 20 parts, ethyl acetate was added so that the nonvolatile content was 50% by mass, By thoroughly stirring, a mixed solution was obtained.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 15 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 36
The solution of the adhesive resin A and the spherical alumina particles are mixed so that the amount of spherical alumina particles (maximum particle size: 12 μm) per 100 parts of the nonvolatile content of the adhesive resin A obtained in Production Example 1 is 200 parts. After that, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 12 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 37
The amount of spherical alumina particles (maximum particle size: 12 μm) per 100 parts of the non-volatile content of the adhesive resin A obtained in Production Example 1 is 200 parts, tackifier [trade name: Pencel, manufactured by Arakawa Chemical Industries, Ltd. D-135] 25 parts, adhesion imparting agent [BIC Chemie Japan Co., Ltd., trade name: BYK-4512] 4 parts of adhesive resin A solution, spherical alumina particles, tackifier and adhesion After mixing with the imparting agent, ethyl acetate was added so that the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 12 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Example 38
The amount of spherical alumina particles (maximum particle size: 12 μm) per 100 parts of the nonvolatile content of the adhesive resin A obtained in Production Example 1 is 220 parts, a tackifier [trade name: Pencel, manufactured by Arakawa Chemical Industries, Ltd. D-135] After mixing the solution of adhesive resin A, spherical alumina particles and tackifier so as to be 100 parts, ethyl acetate was added so that the nonvolatile content was 50% by mass. To obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 12 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Comparative Example 7
The amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A obtained in Production Example 1 (nonvolatile) The heat-dissipating material was obtained by mixing the mixed solution obtained above and the curing agent.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 12 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. One release liner was peeled from this heat radiating sheet to be used as a heat radiating sheet having an adhesive layer on one side. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

Comparative Example 8
A solution of the adhesive resin A so as to be 25 parts of a tackifier per 100 parts of the nonvolatile content of the adhesive resin A obtained in Production Example 1 [trade name: Pencel D-135, manufactured by Arakawa Chemical Industries, Ltd.] And tackifier were mixed, and then ethyl acetate was added so that the content of the nonvolatile content was 50% by mass, and the mixture was sufficiently stirred to obtain a mixed solution.

  Next, the amount of the curing agent [manufactured by Nippon Polyurethane Industry Co., Ltd., polyisocyanate, product name: Coronate L-55E] with respect to 100 parts of the active ingredient (nonvolatile content) of the adhesive resin A becomes 2 parts (nonvolatile content). Thus, the heat dissipation material was obtained by mixing the mixed solution and hardener which were obtained above.

  The heat dissipation material obtained above was applied onto a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and dried in an atmosphere at 100 ° C. for 2 minutes, so that the thickness after drying was about 12 μm. An adhesive layer was formed. Thereafter, the surface of the adhesive layer was protected with a polyester release liner [manufactured by Toyobo Co., Ltd., product number: E-7006], and cured at 40 ° C. for 2 days to obtain a heat radiating sheet. This heat radiating sheet was used as a heat radiating sheet having adhesive layers on both sides by peeling the release liner. When the surface roughness Ra when the release liner was peeled from the heat radiating sheet was measured, the surface roughness Ra was 0.2 μm.

  Next, as the physical properties of the heat dissipation sheets obtained in Examples 30 to 38 and Comparative Examples 7 to 8, the thermal conductivity, thermal resistance, and heat and humidity resistance were examined in the same manner as in Example 1, and further 24 hours passed. The subsequent tackiness and punching workability were examined based on the following methods. The results are shown in Table 2.

[Adhesion after 24 hours]
A test piece was obtained by lining one surface of the heat-dissipating sheet with an aluminum foil having a thickness of 40 μm and cutting it to a width of 25 mm. An aluminum plate having a thickness of 1 mm is attached as an adherend to the non-backed surface of the test piece obtained as described above, and the pressure is pressure-bonded by reciprocating a roller having a mass of 2 kg. It was allowed to stand for 24 hours in an atmosphere at 65 ° C. and a relative humidity of 65%. Thereafter, in the atmosphere, the heat radiating sheet was peeled off from the aluminum plate (adhered body) at a speed of 300 mm / min using a tensile tester in the direction of 180 °, and the adhesive force at that time was measured. The tackiness after 24 hours was evaluated based on the evaluation criteria.

[Evaluation criteria]
30: Adhesive strength is 10 N / 25 mm or more 20: Adhesive force is 1 N / 25 mm or more and less than 10 N / 25 mm 10: Adhesive force is less than 1 N / 25 mm

[Punching workability]
An acrylic resin plate (made of polymethylmethacrylate) having a thickness of 2 mm was placed on the pedestal, and a heat radiating sheet having a width of 50 mm and a length of 50 mm was placed thereon. The heat-dissipating sheet was composed of a release liner (manufactured by Toyobo Co., Ltd., product number: E-7006), an adhesive layer and a release liner (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) in order from the lower layer.

  Next, a test piece was obtained by pressing a Thomson blade having a blade edge angle of 43 ° against the surface of a release liner of a heat dissipation sheet (manufactured by Sanei Kaken Co., Ltd., product number: K-80HS) and cutting the heat dissipation sheet. It was. The peeling state when peeling the release liner from the obtained test piece and the adhesion state of the adhesive to the Thomson blade were observed, and the punching workability was evaluated based on the following evaluation criteria.

[Evaluation criteria]
30: No tearing was observed, the release liner could be easily peeled off, and no adhesive was found on the Thomson blade.
20: Crying is slightly recognized, it is somewhat difficult to peel the release liner, or adhesion of the adhesive to the Thomson blade is slightly recognized.
10: Crying is clearly recognized, it is difficult to peel the release liner, or adhesion of the adhesive to the Thomson blade is remarkably recognized.

  From the results shown in Table 2, the heat-dissipating sheets obtained in each example were in contrast to the heat-dissipating sheets obtained in the respective comparative examples, all of which had thermal conductivity, heat resistance, and adhesion after 24 hours. As a result, it is understood that the heat resistance, heat and humidity resistance and the punching workability are excellent.

  Therefore, from the viewpoint of obtaining a heat-dissipating sheet that is comprehensively excellent in thermal conductivity, heat resistance, adhesiveness after 24 hours, heat and humidity resistance and punching processability, the heat dissipation material is an adhesive resin, an inorganic filler, It contains a curing agent and a tackifier, the thickness of the heat dissipation sheet is 1 to 50 μm, the amount of the inorganic filler per 100 parts by mass of the nonvolatile content of the adhesive resin is 10 to 600 parts by mass, and the amount of the curing agent Is 0.3 to 5 parts by mass, and the amount of the tackifier is preferably 1 to 95 parts by mass.

  From the above results, the heat dissipation sheet of the present invention is expected to be used when, for example, a wiring board and a member that requires heat dissipation such as a heat sink and a housing are joined. In addition, the heat dissipation sheet obtained in each example is, for example, a lighting device having a substrate on which a light emitting element is mounted and a radiator, a smart phone or a tablet terminal that is required to be thin, an electronic device used for wireless power feeding, etc. It can be suitably used when fixing internal components or dissipating heat.

  The heat dissipating sheet of the present invention is, for example, a lighting device using a light emitting diode (LED) or electroluminescence, a backlight lighting device, a battery such as a solar battery or a lithium ion battery, or a computer such as an IC or CPU. Power components such as parts and modules, power circuits such as inverters, touch panels, electromagnetic shields, smartphones and tablet devices that require thinning, components inside electronic devices used for wireless power supply, etc. In addition to being able to be used suitably, it can be suitably used as an adhesive heat-dissipating sheet for imparting adhesiveness to graphite sheets, metal foils, processed products thereof and the like.

Claims (1)

  A heat-dissipating sheet comprising a heat-dissipating material containing an adhesive resin, an inorganic filler, and a curing agent, and having a thickness of 1 to 50 μm.