WO2014069178A1 - Thermally conductive adhesive sheet and method for producing same - Google Patents

Thermally conductive adhesive sheet and method for producing same Download PDF

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Publication number
WO2014069178A1
WO2014069178A1 PCT/JP2013/077273 JP2013077273W WO2014069178A1 WO 2014069178 A1 WO2014069178 A1 WO 2014069178A1 JP 2013077273 W JP2013077273 W JP 2013077273W WO 2014069178 A1 WO2014069178 A1 WO 2014069178A1
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Prior art keywords
conductive particles
heat conductive
thermally conductive
sensitive adhesive
pressure
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PCT/JP2013/077273
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French (fr)
Japanese (ja)
Inventor
中山　純一
憲一 藤川
山口　美穂
翠 東城
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日東電工株式会社
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Application filed by 日東電工株式会社 filed Critical 日東電工株式会社
Priority to KR1020157006482A priority Critical patent/KR20150079559A/en
Priority to CN201380056450.6A priority patent/CN104755574A/en
Publication of WO2014069178A1 publication Critical patent/WO2014069178A1/en

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J4/00—Adhesives based on organic non-macromolecular compounds having at least one polymerisable carbon-to-carbon unsaturated bond ; adhesives, based on monomers of macromolecular compounds of groups C09J183/00 - C09J183/16

Definitions

  • the present invention relates to a heat conductive pressure-sensitive adhesive sheet and a method for producing the same.
  • heat conductivity is improved as compared with a base pressure-sensitive adhesive by containing heat conductive particles in an acrylic pressure-sensitive adhesive.
  • heat conductive particles are adhered by blending heat conductive particles (metal oxide particles and hydrated metal compound particles) having two different average particle sizes.
  • the sheet is closely packed to increase thermal conductivity.
  • the heat conductive particles when the heat conductive particles are densely packed, the heat conductive particles may contact or interfere with each other in the pressure sensitive adhesive sheet, and the hardness of the pressure sensitive adhesive sheet may be excessively increased. If it does so, a malfunction will arise as an adhesive sheet in which moderate softness is calculated
  • an object of the present invention is to provide a heat conductive pressure-sensitive adhesive sheet having excellent heat conductivity and good hardness (appropriate softness) and a method for producing the same.
  • the heat conductive adhesive sheet of this invention is equipped with the acrylic adhesive layer,
  • the said acrylic adhesive layer contains 3 or more types of heat conductive particles from which an average particle diameter differs,
  • the said 3 or more types of heat conduction The space ratio when the conductive particles are mixed is 72% or less, and the content ratio of the three or more kinds of thermally conductive particles with respect to the acrylic pressure-sensitive adhesive layer is 55% by volume or more and 75% by volume or less. It is a feature.
  • At least one of the three or more heat conductive particles is made of a metal oxide or a metal nitride, and the other heat conductive particles. Is preferably made of a metal hydroxide.
  • the content ratio of the thermally conductive particles made of the metal oxide or metal nitride is 5% by volume or more and 25% by volume or less with respect to the acrylic adhesive layer. Is preferred.
  • the three or more kinds of heat conductive particles are first heat conductive particles having an average particle diameter of less than 3 ⁇ m, second heat conductive particles having an average particle diameter of 3 ⁇ m or more and less than 70 ⁇ m, and It is preferable to contain third heat conductive particles having an average particle diameter of 70 ⁇ m or more.
  • the three or more kinds of heat conductive particles are first heat conductive particles having an average particle diameter of less than 3 ⁇ m, second heat conductive particles having an average particle diameter of 3 ⁇ m or more and less than 70 ⁇ m, and It is preferable to contain the 4th heat conductive particle which is a scaly shape with an average particle diameter of 3 micrometers or more and less than 70 micrometers.
  • the said acrylic adhesive layer is obtained by superposing
  • the monomer component does not substantially contain a monomer having a carboxyl group.
  • the polar group-containing monomer contains a nitrogen-containing monomer and / or a hydroxyl group-containing monomer.
  • the hardness of the heat conductive pressure-sensitive adhesive sheet is 80 or less when measured 30 seconds after the pressure surface of the type C durometer is brought into close contact in a type C hardness test. Is preferred.
  • the heat conductive pressure-sensitive adhesive sheet of the present invention preferably has a heat conductivity of 1.7 W / m ⁇ K or more in the thickness direction of the heat conductive pressure-sensitive adhesive sheet.
  • the heat conductive pressure-sensitive adhesive sheet of the present invention it is preferable that the heat conductive pressure-sensitive adhesive sheet satisfies the V-0 standard in the UL94 flame retardant test.
  • the manufacturing method of the heat conductive adhesive sheet of this invention is a method of manufacturing a heat conductive adhesive sheet provided with an acrylic adhesive layer, Comprising: It is an average to the monomer component which has (meth) acrylic-acid alkylester as a main component. Mixing three or more kinds of thermally conductive particles having different particle diameters to obtain a pressure-sensitive adhesive raw material, and reacting the pressure-sensitive adhesive raw material to obtain the acrylic pressure-sensitive adhesive layer. When the heat conductive particles are mixed, the space ratio is 72% or less, and the content ratio of the three or more heat conductive particles with respect to the acrylic pressure-sensitive adhesive layer is 55% by volume to 75% by volume. It is characterized by being.
  • an acrylic pressure-sensitive adhesive layer is provided, and the acrylic pressure-sensitive adhesive layer contains three or more kinds of heat conductive particles having different average particle diameters, and three or more kinds of heat conduction.
  • the space ratio is 72% or less, and the content ratio of the three or more kinds of thermally conductive particles with respect to the acrylic pressure-sensitive adhesive is 55% by volume or more and 75% by volume or less.
  • the heat conductive adhesive sheet of the present invention is excellent in heat conductivity in the thickness direction and has a good hardness.
  • a heat conductive pressure-sensitive adhesive sheet of the present invention a heat conductive pressure-sensitive adhesive sheet having excellent heat conductivity and good hardness can be easily produced.
  • FIG. 1 is an explanatory view for explaining a method for producing a heat conductive pressure-sensitive adhesive sheet, in which FIG. 1 (a) shows a step of applying a pressure-sensitive adhesive material on a base film, and FIG. The process of arrange
  • the heat conductive pressure-sensitive adhesive sheet of the present invention is formed into a sheet shape from a pressure-sensitive adhesive raw material containing a monomer component and / or a polymer component and heat conductive particles.
  • Examples of the monomer component include (meth) acrylic acid alkyl ester monomers as essential components, and optional components include polar group-containing monomers and copolymerizable monomers copolymerizable with these monomers.
  • (meth) acrylic acid alkyl ester monomers examples include methacrylic acid alkyl ester monomers and / or acrylic acid alkyl ester monomers, such as methyl (meth) acrylate, ethyl (meth) acrylate, and propyl (meth) acrylate.
  • (meth) acrylic acid alkyl ester monomers (meth) acrylic acid C2-12 alkyl ester is preferred, and (meth) acrylic acid C4-9 is more preferred, particularly from the viewpoint of easily balancing the adhesive properties.
  • examples include alkyl esters.
  • the (meth) acrylic acid alkyl ester monomer is blended in the monomer component in a proportion of, for example, 60% by mass or more, preferably 80% by mass or more, for example, 99% by mass or less.
  • Examples of polar group-containing monomers include nitrogen-containing monomers, hydroxyl group-containing monomers, sulfo group-containing monomers, nitrogen / hydroxyl group-containing monomers, nitrogen / sulfo group-containing monomers, hydroxyl group / phosphate group-containing monomers, and carboxyl group-containing monomers. Etc.
  • nitrogen-containing monomer examples include cyclic (meth) acrylamides such as N- (meth) acryloylmorpholine and N-acryloylpyrrolidine, such as (meth) acrylamide, N-substituted (meth) acrylamide (eg, N-ethyl (meth) ) Acrylamide, N-alkyl (meth) acrylamides such as Nn-butyl (meth) acrylamide, for example, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl ( N, N-dialkyl such as (meth) acrylamide, N, N-diisopropyl (meth) acrylamide, N, N-di (n-butyl) (meth) acrylamide, N, N-di (t-butyl) (meth) acrylamide (Meth) acrylamide) and other non-cyclic (
  • hydroxyl group-containing monomer examples include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, (meth ) 8-hydroxyoctyl acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl methacrylate, and the like.
  • sulfo group-containing monomer examples include styrene sulfonic acid, allyl sulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid, and the like.
  • nitrogen / hydroxyl monomer examples include N- (2-hydroxyethyl) (meth) acrylamide (HEAA), N- (2-hydroxypropyl) (meth) acrylamide, and N- (1-hydroxypropyl) (meta).
  • HEAA N- (2-hydroxyethyl) (meth) acrylamide
  • N- (2-hydroxypropyl) (meth) acrylamide N- (2-hydroxypropyl) (meth) acrylamide
  • Acrylamide N- (3-hydroxypropyl) (meth) acrylamide, N- (2-hydroxybutyl) (meth) acrylamide, N- (3-hydroxybutyl) (meth) acrylamide, N- (4-hydroxybutyl) N-hydroxyalkyl (meth) acrylamides such as (meth) acrylamide can be mentioned.
  • nitrogen / sulfo group-containing monomer examples include 2- (meth) acrylamide-2-methylpropanesulfonic acid and (meth) acrylamidepropanesulfonic acid.
  • hydroxyl group / phosphate group-containing monomer examples include 2-hydroxyethyl acryloyl phosphate.
  • carboxyl group-containing monomer examples include (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, maleic anhydride, itaconic anhydride, and the like.
  • nitrogen-containing monomers from the viewpoint of imparting high adhesiveness and holding power to the pressure-sensitive adhesive layer (described later), nitrogen-containing monomers, hydroxyl group-containing monomers, nitrogen / hydroxyl group-containing monomers are preferred, and more Preferably, N-vinyl-2-pyrrolidone, N- (meth) acryloylmorpholine, N, N-diethyl (meth) acrylamide, hydroxyethyl (meth) acrylate, hydroxybutyl (meth) acrylate, N- (2- Hydroxyethyl) (meth) acrylamide.
  • the polar group-containing monomer is blended in the monomer component in a proportion of, for example, 1% by mass or more, preferably 5% by mass or more, and for example, 30% by mass or less, preferably 25% by mass or less.
  • a proportion of, for example, 1% by mass or more, preferably 5% by mass or more, and for example, 30% by mass or less, preferably 25% by mass or less is within the above range.
  • the monomer component preferably contains substantially no carboxyl group-containing monomer.
  • the mixing ratio of the carboxyl group-containing monomer is, for example, 5% by mass or less, preferably 1% by mass or less, and more preferably 0.5% by mass or less in the monomer component.
  • the heat conductive particles can be dispersed without gelation.
  • Examples of the copolymerizable monomer include epoxy group-containing monomers such as glycidyl (meth) acrylate and allyl glycidyl ether, such as 2-methoxyethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, (meth) Alkoxy group-containing monomers such as methoxyethylene glycol acrylate and methoxypolypropylene glycol (meth) acrylate, cyano group-containing monomers such as acrylonitrile and methacrylonitrile, styrene monomers such as styrene and ⁇ -methylstyrene, ⁇ -olefins such as ethylene, propylene, isoprene, butadiene and isobutylene, for example, isocyanate groups such as 2-isocyanatoethyl acrylate and 2-isocyanatoethyl methacrylate Monomers, for example, vinyl ester monomers
  • an alkoxy group-containing monomer is preferable, and 2-methoxyethyl acrylate is more preferable.
  • the copolymerizable monomer is blended in the monomer component, for example, at a ratio of 30% by mass or less, preferably 20% by mass or less, for example, 1% by mass or more, preferably 5% by mass or more.
  • These monomers can be used alone (only one kind) or in combination of two or more kinds.
  • the monomer component is, for example, 1% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, for example, 90% by mass or less, preferably 60% by mass in the pressure-sensitive adhesive raw material. % Or less, more preferably 50% by mass or less.
  • the polymer component examples include a polymer (polymer) obtained by reacting the monomer component described above.
  • the polymer is not particularly limited, but, for example, an acrylic polymer, more specifically, a (meth) acrylic acid alkyl ester monomer is used as an essential component, and as an optional component, a polar group-containing monomer, these monomers and Examples thereof include acrylic polymers using copolymerizable monomers that can be copolymerized.
  • the polymer includes a partially polymerized monomer as described above.
  • These polymers can be used alone (only one kind) or in combination of two or more kinds.
  • the polymer component is, for example, 1% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, for example, 50% by mass or less, preferably 40% by mass or less in the pressure-sensitive adhesive raw material. More preferably, it mix
  • the total amount of the monomer component and the polymer component in the pressure-sensitive adhesive material is, for example, 1% by mass or more, preferably 5% by mass or more. More preferably, it is blended so that the ratio is 10% by mass or more, for example, 50% by mass or less, preferably 40% by mass or less, and more preferably 30% by mass or less.
  • Examples of the heat conductive particles include hydrated metal compounds.
  • the hydrated metal compound has a decomposition start temperature in the range of 150 to 500 ° C., and has a general formula MxOy ⁇ nH 2 O (M is a metal atom, x and y are integers of 1 or more determined by the valence of the metal, and n is contained) Or a double salt containing the above compound.
  • Examples of the hydrated metal compound include aluminum hydroxide [Al 2 O 3 .3H 2 O; or Al (OH) 3 ], boehmite [Al 2 O 3 .H 2 O; or AlOOH], magnesium hydroxide [MgO H 2 O; or Mg (OH) 2 ], calcium hydroxide [CaO ⁇ H 2 O; or Ca (OH) 2 ], zinc hydroxide [Zn (OH) 2 ], silicic acid [H 4 SiO 4 ; H 2 SiO 3 ; or H 2 Si 2 O 5 ], iron hydroxide [Fe 2 O 3 .H 2 O or 2FeO (OH)], copper hydroxide [Cu (OH) 2 ], barium hydroxide [BaO.
  • Hydrated metal compounds are commercially available.
  • aluminum hydroxide the trade name “Hijilite H-100-ME” (average particle size 75 ⁇ m) (manufactured by Showa Denko KK), the trade name “Hijilite H-10” is available.
  • the thermally conductive particles include, for example, metal nitrides such as boron nitride, aluminum nitride, silicon nitride, and gallium nitride, such as silicon dioxide, aluminum oxide, magnesium oxide, and oxide.
  • metal nitrides such as boron nitride, aluminum nitride, silicon nitride, and gallium nitride, such as silicon dioxide, aluminum oxide, magnesium oxide, and oxide.
  • Metal oxides such as titanium, zinc oxide, tin oxide, copper oxide, nickel oxide, such as silicon carbide, antimonic acid doped tin oxide, calcium carbonate, barium titanate, potassium titanate, copper, silver, gold, nickel, aluminum Platinum, carbon black, carbon tube (carbon nanotube), carbon fiber, diamond and the like.
  • thermally conductive particles are commercially available, for example, as boron nitride, trade name “HP-40” (manufactured by Mizushima Alloy Iron Co., Ltd.), trade name “PT110” (average particle size 35 ⁇ m) (manufactured by Momentive)
  • the product name “AL-13KT” average particle size 97 ⁇ m) (manufactured by Showa Denko)
  • AS-50 Showa Denko
  • AS-10 manufactured by Showa Denko KK
  • antimonic acid doped tin the product name “SN-100S” (manufactured by Ishihara Sangyo Co., Ltd.), the product name “SN-100P” (Ishihara Sangyo Co., Ltd.)
  • Product name “SN-100D (water-dispersed product)” (manufactured by Ishihara Sangyo Co., Ltd.), for example, titanium oxide, product name “
  • thermally conductive particles preferably, a hydrated metal compound is used, and more preferably, aluminum hydroxide is used because it imparts high thermal conductivity and flame retardancy to the pressure-sensitive adhesive layer.
  • metal nitrides and metal oxides are also preferable, and boron nitride, aluminum oxide, and magnesium oxide are more preferable.
  • the shape of the thermally conductive particles is not particularly limited, and may be a bulk shape, a needle shape, a plate shape, or a scale shape (including a layer shape).
  • the bulk shape includes, for example, a spherical shape, a rectangular parallelepiped shape, a crushed shape, a round shape, an aggregate, or a deformed shape thereof.
  • the heat conductive particles contain three or more kinds of heat conductive particles having different average particle diameters.
  • the space ratio when mixing three or more kinds of thermally conductive particles having different average particle diameters is 72% or less, preferably 70% or less, and more preferably 65% or less. And, for example, 30% or more, preferably 50% or more, and more preferably 55% or more.
  • the tap density is measured using a powder characteristic evaluation device (powder tester “PT-R”, manufactured by Hosokawa Micron Corporation).
  • the true density of the thermally conductive particles is, for example, 0.8 g / cm 3 or more, preferably 1.5 g / cm 3 or more, and for example, 20 g / cm 3 or less, preferably 10 g / cm 3 or less. But there is.
  • the true density of the thermally conductive particles is determined by a dry densimeter (gas displacement method).
  • the heat conductive particles are a first heat conductive particle having an average particle diameter of less than 3 ⁇ m, a second heat conductive particle having an average particle diameter of 3 ⁇ m or more and less than 70 ⁇ m, and at least one kind of heat having a different average particle diameter. Contains conductive particles.
  • the thermally conductive particles contain first thermally conductive particles, second thermally conductive particles, and third thermally conductive particles having an average particle diameter of 70 ⁇ m or more.
  • the heat conductive particles contain first heat conductive particles, second heat conductive particles, and fourth heat conductive particles having an average particle diameter of 3 ⁇ m or more and less than 70 ⁇ m and having a scaly shape.
  • a higher thermal conductivity can be imparted to the pressure-sensitive adhesive layer.
  • the average particle diameter of the first heat conductive particles is less than 3 ⁇ m, preferably 2 ⁇ m or less, and for example, 0.5 ⁇ m or more.
  • Examples of the shape of the first thermally conductive particles include the shapes described above, and preferably a bulk shape.
  • the average particle diameter of the second heat conductive particles is 3 ⁇ m or more, preferably 20 ⁇ m or more, and is, for example, less than 70 ⁇ m, preferably less than 60 ⁇ m.
  • the shape of the second thermally conductive particles includes the above-described shape, and preferably a bulk shape.
  • the average particle size of the third heat conductive particles is 70 ⁇ m or more, preferably 90 ⁇ m or more, and is, for example, less than 300 ⁇ m, preferably less than 150 ⁇ m.
  • the shape of the third thermally conductive particles includes the above-described shape, and preferably a bulk shape.
  • the fourth heat conductive particles are formed in a scale shape, and the average particle diameter thereof is 3 ⁇ m or more, preferably 20 ⁇ m or more, and for example, less than 70 ⁇ m, preferably less than 50 ⁇ m.
  • the average particle size of the thermally conductive particles is determined by a particle size distribution measurement method in the laser scattering method (specifically, measured by a laser scattering particle size distribution meter), based on a D50 value (cumulative 50% median). (Diameter).
  • thermally conductive particles preferably, at least one of the thermally conductive particles is formed of a metal oxide or a metal nitride, and the other thermally conductive particles are a metal hydroxide. Formed from.
  • the first thermally conductive particles are preferably formed from a metal hydroxide, more preferably aluminum hydroxide.
  • the second thermally conductive particles are preferably formed from metal hydroxide, metal oxide or metal nitride, more preferably from aluminum hydroxide or magnesium oxide.
  • the third thermally conductive particles are preferably formed from metal oxide or metal nitride, more preferably metal oxide, and still more preferably aluminum oxide.
  • the fourth thermally conductive particles are made of metal oxide or metal nitride, more preferably metal nitride, and still more preferably boron nitride.
  • the heat conductive particles formed from the metal hydroxide are, for example, 30% by volume or more, preferably 40% by volume or more, and, for example, 70% by volume or less with respect to the pressure-sensitive adhesive raw material.
  • the content ratio of the heat conductive particles formed from metal oxide or metal nitride is, for example, 5% by volume or more with respect to the pressure-sensitive adhesive raw material.
  • the heat conductive particles only need to contain three or more kinds of heat conductive particles having an average particle diameter, and for example, may contain four kinds of heat conductive particles having an average particle diameter.
  • the first heat conductive particles include the second heat conductive particles, the third heat conductive particles, and the fourth heat conductive particles.
  • the thermally conductive particles two or more kinds of average particle diameters can be further provided.
  • the second heat conductive particles having an average particle diameter of 3 ⁇ m or more and less than 70 ⁇ m are further, for example, the second heat conductive particles having an average particle diameter of 3 ⁇ m or more and less than 40 ⁇ m and the second heat conductive particles having an average particle diameter of 40 ⁇ m or more and less than 70 ⁇ m.
  • Thermally conductive particles can be provided.
  • the first heat conductive particles may include the second heat conductive particles, the third heat conductive particles, and the fourth heat conductive particles, which include heat conductive particles made of two or more different materials. It can.
  • the second thermally conductive particles include thermally conductive particles made of two different materials. That is, the heat conductive particles preferably include first heat conductive particles and two types of second heat conductive particles formed of different materials.
  • Such two different materials preferably include a combination of a metal hydroxide and a metal oxide, more preferably a combination of magnesium hydroxide and magnesium oxide.
  • the blending ratio of the first heat conductive particles in the total amount of the heat conductive particles is, for example, 10% by mass or more, preferably 20% by mass or more, more preferably 30% by mass or more, and for example, 70% by mass. % Or less, preferably 55% by mass or less, more preferably 45% by mass or less.
  • the blending ratio of the second thermally conductive particles in the total amount of thermally conductive particles is, for example, 15% by mass or more, preferably 25% by mass or more, more preferably 35% by mass or more, and for example, 70% by mass. % Or less, preferably 60% by mass or less, more preferably 50% by mass or less.
  • the sum total of the mixture ratio is 30 for example with respect to the total amount of heat conductive particles.
  • % By mass or more preferably 40% by mass or more, more preferably 50% by mass or more, and for example, 80% by mass or less, preferably 75% by mass or less, more preferably 70% by mass or less. .
  • the blending ratio of the third heat conductive particles in the total amount of the heat conductive particles is, for example, 5% by mass or more, preferably 10% by mass or more, and more preferably. Is 15% by mass or more, and is, for example, 50% by mass or less, preferably 40% by mass or less, and more preferably 30% by mass or less.
  • the blending ratio of the fourth heat conductive particles in the total amount of the heat conductive particles is, for example, 1% by mass or more, preferably 5% by mass or more, and more preferably. Is 10% by mass or more, and for example, 40% by mass or less, preferably 30% by mass or less, more preferably 20% by mass or less.
  • the total amount of these heat conductive particles is, for example, 75% by mass or more, preferably 80% by mass or more, for example, 90% by mass or less, preferably 87% by mass or less in the pressure-sensitive adhesive raw material. Is done.
  • the total amount of the heat conductive particles is 55% by volume or more, preferably 60% by volume or more, and 75% by volume or less, preferably 70% by volume or less in the pressure-sensitive adhesive raw material.
  • the blending ratio of the heat conductive particles is within the above range, high thermal conductivity, good hardness and flame retardancy can be imparted to the pressure-sensitive adhesive layer.
  • a monomer composition containing the above-described monomer component and a polymerization initiator is prepared.
  • a polymerization initiator is blended with the above monomer components.
  • polymerization initiator examples include a photopolymerization initiator and a thermal polymerization initiator.
  • the photopolymerization initiator examples include a benzoin ether photopolymerization initiator, an acetophenone photopolymerization initiator, an ⁇ -ketol photopolymerization initiator, an aromatic sulfonyl chloride photopolymerization initiator, and a photoactive oxime photopolymerization initiator.
  • Agents benzoin photopolymerization initiators, benzyl photopolymerization initiators, benzophenone photopolymerization initiators, thioxanthone photopolymerization initiators, and the like.
  • benzoin ether photopolymerization initiator examples include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, and anisole.
  • examples include methyl ether.
  • acetophenone photopolymerization initiator examples include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 4-phenoxydichloroacetophenone, 4- (t-butyl) dichloroacetophenone, and the like.
  • Examples of ⁇ -ketol photopolymerization initiators include 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) phenyl] -2-methylpropan-1-one, and 1-hydroxy. Examples include cyclohexyl phenyl ketone.
  • aromatic sulfonyl chloride photopolymerization initiator examples include 2-naphthalene sulfonyl chloride.
  • Examples of the photoactive oxime photopolymerization initiator include 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime.
  • benzoin photopolymerization initiator examples include benzoin.
  • benzyl photopolymerization initiator examples include benzyl.
  • benzophenone photopolymerization initiator examples include benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone, and polyvinylbenzophenone.
  • thioxanthone photopolymerization initiator examples include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, decylthioxanthone, and the like.
  • thermal polymerization initiator examples include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis (2-methylpropionic acid) dimethyl, 4,4'-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis [2- (5-methyl-2- Imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (N, N'-dimethyleneisobutylamidine) hydrochloride, 2, Azo polymerization initiators such as 2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate, Peroxide polymerization initiators such as zoyl peroxide, t-butyl permaleate, t-butyl hydro
  • These polymerization initiators can be used alone (only one kind) or in combination of two or more kinds.
  • a photopolymerization initiator is preferable because of the advantage that the polymerization time can be shortened.
  • the photopolymerization initiator is not particularly limited, but is, for example, 0.01 parts by mass or more, preferably 0 with respect to 100 parts by mass of the monomer component. 0.05 parts by mass or more, and for example, 5 parts by mass or less, preferably 3 parts by mass or less.
  • thermal polymerization initiator when a thermal polymerization initiator is blended as a polymerization initiator, the thermal polymerization initiator is not particularly limited and is blended in an available ratio.
  • a part of the monomer component can be polymerized if necessary.
  • the mixture of the monomer component and the photopolymerization initiator is irradiated with ultraviolet rays.
  • the monomer composition has a viscosity (BH viscometer, No. 5 rotor, 10 rpm, measurement temperature 30 ° C.) with irradiation energy that excites the photopolymerization initiator, for example, 5 Pa ⁇ s. Irradiation is carried out until it is above (preferably 10 Pa ⁇ s or more), for example, 30 Pa ⁇ s or less (preferably 20 Pa ⁇ s or less).
  • the mixture of the monomer component and the thermal polymerization initiator is polymerized at, for example, a temperature higher than the decomposition temperature of the thermal polymerization initiator, specifically about 20 to 100 ° C.
  • the viscosity of the monomer composition is, for example, 5 Pa ⁇ s or more (preferably 10 Pa ⁇ s or higher), for example, 30 Pa ⁇ s or lower (preferably 20 Pa ⁇ s or lower).
  • a (meth) acrylic acid alkyl ester monomer When preparing a monomer composition by polymerizing a part of the monomer component, a (meth) acrylic acid alkyl ester monomer, a monomer selected from a polar group-containing monomer and a copolymerizable monomer, and a polymerization initiator As described above, a part of the monomer can be polymerized, and then a crosslinking agent can be blended.
  • the crosslinking agent is a polyfunctional compound having a plurality of ethylenically unsaturated hydrocarbon groups.
  • the crosslinking agent can be used alone or in combination of two or more.
  • dipentaerythritol hexa (meth) acrylate is preferable.
  • the content of the crosslinking agent is, for example, 0.001 part by mass or more, preferably 0.01 part by mass or more, for example, 10 parts by mass or less, preferably 1 part by mass with respect to 100 parts by mass of the monomer component. It is also below mass parts.
  • the above-described monomer composition is blended with the above-described thermally conductive particles.
  • heat conductive particles etc. can be mix
  • the pressure-sensitive adhesive raw material forms a polymer component containing the thermally conductive particles by polymerizing all the monomer components in the monomer composition in which the thermally conductive particles are blended. It can also be prepared as a polymer composition by dissolving in a solvent.
  • dispersants for monomer compositions and polymer compositions, dispersants, tackifiers, acrylic oligomers, silane coupling agents, fluorosurfactants, plasticizers, fillers, anti-aging agents, colorants, etc., are necessary. These additives can also be blended.
  • a dispersant is preferably blended in the monomer composition or the polymer composition.
  • the dispersant include phosphate ester-based dispersants. Specifically, polyoxyethylene alkyl (or alkylallyl) ether or polyoxyethylene alkylaryl ether phosphate monoester, polyoxyethylene alkyl ether Alternatively, polyoxyethylene alkylaryl ether phosphoric acid diesters, phosphoric acid triesters, derivatives thereof, and the like can be given.
  • phosphate ester dispersants can be used alone or in combination of two or more.
  • the blending ratio of the dispersant in the pressure-sensitive adhesive raw material is, for example, 0.01% by mass or more, preferably 0.1% by mass or more, and for example, 10% by mass or less, preferably 5% by mass or less. is there.
  • the viscosity of the obtained pressure-sensitive adhesive material is, for example, 50 Pa ⁇ s or less, preferably 40 Pa ⁇ s or less, more preferably 35 Pa ⁇ s or less. Also, for example, 5 Pa ⁇ s or more, more preferably 10 Pa ⁇ s or more.
  • the pressure-sensitive adhesive material may contain bubbles.
  • a heat conductive adhesive sheet can be made into a foam by producing a heat conductive adhesive sheet using the adhesive raw material containing air bubbles.
  • a stator fixed tooth
  • a rotor having a large number of teeth on the disk facing the stator
  • a gas is introduced into the adhesive raw material.
  • the gas introduced into the pressure-sensitive adhesive raw material is not particularly limited, and examples thereof include inert gases such as nitrogen, carbon dioxide, and argon, such as air.
  • the gas introduced into the pressure-sensitive adhesive material is preferably an inert gas, more preferably nitrogen, because it hardly inhibits the reaction of the pressure-sensitive adhesive material.
  • the bubbles are, for example, 5% by volume or more, preferably 10% by volume or more, more preferably 12% by volume or more, for example, 50% by volume or less, based on the total volume of the pressure-sensitive adhesive material. Preferably, it is introduced at a ratio of 40% by volume or less, more preferably 35% by volume or less.
  • FIG. 1 is an explanatory view for explaining a method for producing a heat conductive pressure-sensitive adhesive sheet.
  • a pressure-sensitive adhesive material 2 is applied to the surface of the base film 1 as a base material that has been subjected to a peeling treatment.
  • the base film 1 examples include a polyester film (polyethylene terephthalate film and the like), for example, a fluorine-based polymer (for example, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoro).
  • a fluorine-based polymer for example, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoro.
  • Fluorine film made of propylene copolymer, chlorofluoroethylene-vinylidene fluoride copolymer, etc. for example, olefin resin film made of olefin resin (polyethylene, polypropylene, etc.), eg, polyvinyl chloride film, polyimide film , Polyamide base film (nylon film), plastic base film (synthetic resin film) such as rayon film, eg, fine paper, Japanese paper, kraft paper, glass Down paper, synthetic paper, paper such as top-coated paper, for example, and they were double layered composites and the like.
  • olefin resin film made of olefin resin polyethylene, polypropylene, etc.
  • polyvinyl chloride film polyimide film
  • Polyamide base film polyamide base film
  • plastic base film synthetic resin film
  • rayon film eg, fine paper, Japanese paper, kraft paper, glass Down paper
  • synthetic paper paper such as top-coated paper, for example, and they were double
  • the adhesive raw material 2 is prepared as a monomer composition and contains a photopolymerization initiator
  • a base film 1 that transmits ultraviolet rays is used so as not to interfere with irradiation of ultraviolet rays to the adhesive raw material 2. To do.
  • Examples of the method for applying the adhesive material 2 to the base film 1 include roll coating, kiss roll coating, gravure coating, reverse coating, roll brush, spray coating, dip roll coating, bar coating, knife coating, air knife coating, Examples include an extrusion coating method using a curtain coat, a lip coat, a die coater, and the like.
  • the coating thickness of the pressure-sensitive adhesive raw material 2 is, for example, 10 ⁇ m or more, preferably 50 ⁇ m or more, more preferably 100 ⁇ m or more, and for example, 10,000 ⁇ m or less, preferably 5000 ⁇ m or less, more preferably 3000 ⁇ m or less. But there is.
  • a cover film 3 is then placed on the coating film of the pressure-sensitive adhesive raw material 2 as shown in FIG. In order to arrange
  • cover film 3 examples include the same film as the base film 1 described above. Further, when the pressure-sensitive adhesive raw material 2 is prepared as a monomer composition and contains a photopolymerization initiator, a cover film 3 that transmits ultraviolet rays is used so as not to interfere with irradiation of the pressure-sensitive adhesive raw material 2 with ultraviolet rays. To do.
  • the adhesive raw material 2 is prepared as a monomer composition
  • the adhesive raw material 2 is reacted as shown in FIG.
  • the system pressure-sensitive adhesive layer 4 is formed.
  • the adhesive raw material 2 is irradiated with ultraviolet rays and the thermal polymerization initiator is blended.
  • the adhesive raw material 2 is heated.
  • the acrylic pressure-sensitive adhesive layer 4 is formed by applying the pressure-sensitive adhesive material 2 and drying it to remove the solvent.
  • the thickness of the acrylic pressure-sensitive adhesive layer 4 of the obtained heat conductive pressure-sensitive adhesive sheet is, for example, 10 ⁇ m or more, preferably 50 ⁇ m or more, more preferably 100 ⁇ m or more, and for example, 10,000 ⁇ m or less, preferably 5000 ⁇ m. Hereinafter, more preferably, it is 3000 ⁇ m or less.
  • the thickness of the acrylic pressure-sensitive adhesive layer 4 By setting the thickness of the acrylic pressure-sensitive adhesive layer 4 to 10 ⁇ m or more, better adhesive force can be obtained. Further, by setting the thickness of the acrylic pressure-sensitive adhesive layer 4 to 10000 ⁇ m or less, better thermal conductivity can be obtained.
  • the content ratio of the heat conductive particles to the acrylic pressure-sensitive adhesive layer 4 is 55% by volume or more, preferably 60% by volume or more, and 75% by volume or less. Preferably, it is also 70 volume% or less.
  • the content ratio of the heat conductive particles made of metal oxide or metal nitride is, for example, 5% by volume or more with respect to the acrylic pressure-sensitive adhesive layer 4, preferably 8 volume% or more, and for example, 25 volume% or less, preferably 20 volume% or less.
  • the thermal conductivity and flame retardancy are good.
  • the content ratio of the heat conductive particles made of metal hydroxide is, for example, 30% by volume or more, preferably 40% by volume or more, and, for example, 70% by volume or less with respect to the acrylic pressure-sensitive adhesive layer 4. Preferably, it is 60 volume% or less.
  • the obtained heat conductive pressure-sensitive adhesive sheet preferably has first heat conductive particles having an average particle diameter of less than 3 ⁇ m, second heat conductive particles having an average particle diameter of 3 ⁇ m or more and less than 70 ⁇ m, and an average particle diameter of 70 ⁇ m or more. 3rd heat conductive particle and / or 4th heat conductive particle which is a scaly shape with an average particle diameter of 3 micrometers or more and less than 70 micrometers are contained.
  • 90 degree peeling adhesive strength of the obtained heat conductive adhesive sheet is, for example, 3N / 20mm or more, preferably 10N / 20mm or more, more preferably 15N / 20mm or more, for example, 100N / 20mm or less.
  • the hardness (measured according to the type C hardness test specified in JIS K 7312) of the obtained heat conductive adhesive sheet is 3 after the pressure surface of the type C durometer is brought into close contact.
  • it is, for example, 80 or less, preferably 70 or less, and for example, 20 or more, preferably 30 or more.
  • the thermal conductivity of the acrylic pressure-sensitive adhesive layer 4 of the obtained heat conductive pressure-sensitive adhesive sheet is, for example, 1.7 W / m ⁇ K or more, preferably 2.0 W / m ⁇ K or more, more preferably 2.5 W / m ⁇ K or more, for example, 10 W / m ⁇ K or less.
  • the obtained heat conductive pressure-sensitive adhesive sheet is, for example, flame retardant UL94 standard V-0.
  • a heat conductive adhesive sheet is excellent in flame retardancy when the flame retardancy UL94 standard is V-0.
  • This heat conductive adhesive sheet includes an acrylic adhesive layer 4. Therefore, the acrylic pressure-sensitive adhesive layer 4 has tackiness on both sides. Therefore, it can be used as a double-sided pressure-sensitive adhesive (pressure-sensitive adhesive) sheet.
  • the acrylic adhesive layer 4 contains three or more types of heat conductive particles having different average particle diameters, and the space ratio when three or more types of heat conductive particles are mixed. However, it is 72% or less, and the content rate of 3 or more types of heat conductive particles with respect to the acrylic adhesive layer 4 is 55 volume% or more and 75 volume% or less.
  • the acrylic pressure-sensitive adhesive layer 4 is closely packed with the heat conductive particles while maintaining an appropriate distance. Therefore, even when the acrylic pressure-sensitive adhesive layer 4 is deformed, Contact or interference between the thermally conductive particles is suppressed. Therefore, it has excellent thermal conductivity and good hardness (appropriate softness). Furthermore, it also has good flame retardancy.
  • the manufacturing method of an above described heat conductive adhesive sheet is the monomer component (monomer composition) which has (meth) acrylic-acid alkylester as a main component, and the heat conductive particle which is 3 or more types from which an average particle diameter differs.
  • a step of mixing to obtain the pressure-sensitive adhesive raw material 2 and a step of reacting the pressure-sensitive adhesive raw material 2 to obtain the acrylic pressure-sensitive adhesive layer 4 are provided.
  • the pressure-sensitive adhesive material 2 can be applied to the base film 1 to form the acrylic pressure-sensitive adhesive layer 4, the heat conductive particles are densely packed without performing a compression step such as hot pressing. , Gaps generated between the thermally conductive particles (location where the monomer component or polymer component is filled) can be reduced. Therefore, a heat conductive adhesive sheet provided with the outstanding heat conductivity can be manufactured simply.
  • this heat conductive adhesive sheet is excellent in heat conductivity and a flame retardance, it is a semiconductor device, a hard disk, LED device (television, illumination, a display, etc.), EL device (organic EL display, organic EL illumination, etc.) ), Capacitors, capacitors, batteries (such as lithium ion batteries), and power modules.
  • thermoly conductive particles measured according to the following.
  • D50 value (accumulated 50% based on the particle size distribution measured by a laser scattering particle size distribution meter (trade name SALD-2100, manufactured by Shimadzu Corporation)). Median diameter). -Porosity of thermally conductive particles (%) The space ratio of the heat conductive particles was calculated according to the following formula.
  • the tap density was measured using a powder tester “PT-R” (manufactured by Hosokawa Micron Co., Ltd.) by selecting “hardened bulk density” measurement as the measurement mode. Specifically, the heat conductive particles were filled in the cup using a sieve having an aperture of 1.1 mm, and then tapped 360 times with a tapping stroke of 18 mm. After tapping, the upper part of the cup was scraped with a flat plate, and the tap density was determined from the mass of the thermally conductive particles filled in the cup.
  • the true density of the thermally conductive particles was calculated by a dry density meter (trade name Accupic 1330, manufactured by Shimadzu Corporation) (gas displacement method).
  • Example 1 Preparation of monomer composition
  • EHA 2-ethylhexyl acrylate
  • MEA 2-methoxyethyl acrylate
  • NVP N-vinyl-2-pyrrolidone
  • HEAA hydroxyethyl acrylamide
  • DPHA dipentaerythritol hexaacrylate, trade name “KAYARAD DPHA-40H”, manufactured by Nippon Kayaku Co., Ltd.
  • Plisurf trade name “Plisurf”
  • A212E (Daiichi Kogyo Seiyaku Co., Ltd.) 3 parts by mass was blended and mixed to obtain a monomer composition.
  • the obtained adhesive material is dried and cured on the release surface of a base film (polyethylene terephthalate film, trade name “Diafoil MRF38”, manufactured by Mitsubishi Chemical Polyester Film Co., Ltd.) that has been subjected to release treatment on one side. It applied so that thickness might be set to 1000 micrometers (refer Fig.1 (a)).
  • a base film polyethylene terephthalate film, trade name “Diafoil MRF38”, manufactured by Mitsubishi Chemical Polyester Film Co., Ltd.
  • a cover film (the same film as the base film) was placed on the adhesive material coating film so that the adhesive material coating film was sandwiched between the base film (see FIG. 1B).
  • the adhesive raw material was irradiated with ultraviolet rays (illuminance of about 5 mW / cm 2 ) for 3 minutes (corresponding to an irradiation energy of 900 mJ / cm 2 ) from both sides (base film side and cover film side).
  • the monomer component in the pressure-sensitive adhesive raw material was polymerized to form an acrylic pressure-sensitive adhesive layer, and a heat conductive pressure-sensitive adhesive sheet was produced (see FIG. 1C).
  • the pressure-sensitive adhesive layer of the thermally conductive pressure-sensitive adhesive sheet of Example 1 had tackiness on the front and back surfaces. From this, it has confirmed that it was a double-sided adhesive sheet.
  • thermally conductive pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the kind of thermally conductive particles and the blending ratio thereof were changed to the blending ratios shown in Table 1.
  • Each of the pressure-sensitive adhesive layers of the heat conductive pressure-sensitive adhesive sheet of each example had tackiness on the front surface and the back surface. From this, it has confirmed that it was a double-sided adhesive sheet.
  • Blending ratio of heat conductive particles in the pressure-sensitive adhesive layer (mass%, volume%), blending ratio of aluminum hydroxide in the pressure-sensitive adhesive layer (volume%), blending of metal oxide and metal nitride in the pressure-sensitive adhesive layer
  • Table 1 shows the ratio (volume%) and the space ratio of the thermally conductive particles.
  • Comparative Examples 1 to 4 A thermally conductive pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the kind of thermally conductive particles and the blending ratio thereof were changed to the blending ratios shown in Table 1. In Comparative Example 4, the pressure-sensitive adhesive material in the blending ratio described in Comparative Example 4 could not be formed into a sheet shape.
  • Each adhesive layer of the heat conductive adhesive sheet of each comparative example had tackiness on the front surface and the back surface. From this, it has confirmed that it was a double-sided adhesive sheet.
  • Blending ratio of heat conductive particles in the pressure-sensitive adhesive layer (mass%, volume%), blending ratio of aluminum hydroxide in the pressure-sensitive adhesive layer (volume%), blending of metal oxide and metal nitride in the pressure-sensitive adhesive layer
  • Table 1 shows the ratio (volume%) and the space ratio of the thermally conductive particles.
  • thermal conductivity The thermal conductivity of the thermally conductive tape was measured. That is, the thermal conductivity in the thickness direction (TD) was measured by a pulse heating method using a xenon flash analyzer “LFA-447 type” (manufactured by NETZSCH).
  • the heat conductive adhesive sheet is cut into a 1 cm ⁇ 1 cm square to obtain a section, and the surface of the section (one surface in the thickness direction) is coated with a heat conductive sheet carbon spray (carbon alcohol dispersion) and dried.
  • the portion was used as a light receiving portion, and carbon spray was applied to the back surface (the other surface in the thickness direction) to form a detection portion.
  • the thermal diffusivity (D1) in the thickness direction was measured by irradiating the light receiving part with an energy ray by a xenon flash and detecting the temperature of the detecting part.
  • thermal conductivity (TC1) in the thickness direction of the thermally conductive adhesive sheet was determined by the following formula. The results are shown in Table 1.
  • TC1 D1 ⁇ ⁇ ⁇ Cp ⁇ : density of heat conductive tape at 25 ° C. (sample was punched to 2.5 cm ⁇ , and density was calculated from thickness and weight)
  • Cp Specific heat of the heat conductive tape (specific heat was measured by DSC by the following specific heat capacity measurement) (Specific heat capacity measurement) The specific heat capacity was measured using a differential scanning calorimeter (hereinafter DSC) “EXSTAR 6200” (manufactured by Seiko Instruments Inc.) under the following conditions.
  • DSC differential scanning calorimeter
  • Cp h / H ⁇ m ′ / m ⁇ C′p
  • Cp specific heat capacity of heat conductive tape (J / g ° C)
  • C′p specific heat capacity of reference material (J / g ° C.)
  • h Difference in DSC curve between empty container and heat conduction tape
  • H Difference in DSC curve between empty container and reference material
  • m Weight of heat conduction tape
  • m ′ reference substance weight (g)
  • the temperature was raised at a rate of 10 ° C./min, and after reaching 65 ° C., the temperature was kept isothermal for 5 minutes.
  • DSC curves of the empty container, sapphire, and heat conductive tape were obtained, and the specific heat capacity of the heat conductive tape at 25 ° C. was obtained from the above equation. This operation was repeated three times, and the average value was used as the specific heat capacity.
  • an evaluation sample was prepared by cutting the pressure-sensitive adhesive layer of the heat-conductive pressure-sensitive adhesive sheet into a width of 20 mm and a length of 20 mm, and laminating it so as to have a thickness of 4 mm. ), The hardness (Asker C hardness) 30 seconds after the pressure surface of the Asker C hardness tester was brought into close contact under an atmosphere of 23 ° C. and 50% RH. The results are shown in Table 1.
  • the heat conductive adhesive sheet prepared in each example and comparative example was cut into a size of 12.7 mm ⁇ 127 mm, the base film and the cover film were peeled off, and five test pieces were prepared, respectively. The test was conducted.
  • test pieces were fixed and the lower ends were suspended. Then, the flame of the burner was first applied to the lower end of the test piece for 10 seconds, and then the flame was released from the test piece, and then the flame was applied again to the lower end of the test piece for 10 seconds.
  • the total flammable combustion time of each test piece (the total of the combustion time after applying the first flame and the combustion time after applying the second flame) is within 10 seconds.
  • the flame burning time and the flameless burning time of each test piece after applying the flame for the second time are within 30 seconds.
  • ⁇ The number of evaluation items satisfying the above 1 to 5 is 3 or more and satisfies the V-0 standard.
  • X The number of evaluation items that satisfy the above 1 to 5 is less than 3, and the V-0 standard is not satisfied.
  • the unit of a monomer component, a polymerization initiator, a crosslinking agent, and a dispersant is part by mass.
  • Hijilite H-42 trade name, manufactured by Showa Denko KK, aluminum hydroxide, average particle size 1 ⁇ m, crushed, true density 2.4 g / cm 3 BE033: trade name, manufactured by Nippon Light Metal Co., Ltd., aluminum hydroxide, average particle size 3 ⁇ m, crushed, true density 2.4 g / cm 3
  • Hijilite H-31 trade name, manufactured by Showa Denko KK, aluminum hydroxide, average particle diameter 18 ⁇ m, crushed), true density 2.4 g / cm 3 ⁇ Hijilite H-10: trade name, manufactured by Showa Denko KK, aluminum hydroxide, average particle size 55 ⁇ m, crushed, true density 2.4 g / cm 3 MCP524-50: trade name, manufactured by Ube Materials, magnesium oxide, average particle size 50 ⁇ m, spherical, true density 3.6 g / cm 3 AL-13KT: trade name, manufactured by Showa Denko
  • the heat conductive pressure-sensitive adhesive sheet of the present invention can be applied to various industrial products, such as a semiconductor device, a hard disk, an LED device, an EL device, a heat dissipation sheet attached to a capacitor, a capacitor, a battery, a power module, and the like. Is mentioned.

Abstract

This thermally conductive adhesive sheet is provided with an acrylic adhesive layer. The acrylic adhesive layer contains three or more kinds of thermally conductive particles which have different average particle diameters, and the porosity when the three or more kinds of thermally conductive particles are mixed is 72% or less. The content ratio of the three or more kinds of thermally conductive particles relative to the acrylic adhesive layer is from 55% by volume to 75% by volume (inclusive).

Description

熱伝導性粘着シートおよびその製造方法Thermally conductive adhesive sheet and method for producing the same
　本発明は、熱伝導性粘着シートおよびその製造方法に関する。 The present invention relates to a heat conductive pressure-sensitive adhesive sheet and a method for producing the same.
　従来、熱伝導性シートにおいて、アクリル系粘着剤中に熱伝導性粒子を含有させることにより、ベースとなる粘着剤に比べて熱伝導性を向上させることが知られている。 Conventionally, in a heat conductive sheet, it is known that heat conductivity is improved as compared with a base pressure-sensitive adhesive by containing heat conductive particles in an acrylic pressure-sensitive adhesive.
　例えば、アクリル共重合体と、平均粒径が２０～２００μｍの金属酸化物の粒子と、平均粒径１０μｍ以下の水和金属化合物の粒子を含有する熱伝導性粘着シートが提案されている（下記特許文献１参照。）。 For example, a heat conductive pressure-sensitive adhesive sheet containing an acrylic copolymer, metal oxide particles having an average particle diameter of 20 to 200 μm, and hydrated metal compound particles having an average particle diameter of 10 μm or less has been proposed (see below). (See Patent Document 1).
特開２００４－２７０３９号公報Japanese Patent Laid-Open No. 2004-27039
　上記特許文献１に記載の熱伝導性粘着シートでは、異なる２種の平均粒子径の熱伝導性粒子（金属酸化物粒子および水和金属化合物粒子）を配合することにより、熱伝導性粒子を粘着シート内に密に充填し、熱伝導性を高めている。 In the heat conductive adhesive sheet described in Patent Document 1, heat conductive particles are adhered by blending heat conductive particles (metal oxide particles and hydrated metal compound particles) having two different average particle sizes. The sheet is closely packed to increase thermal conductivity.
　しかしながら、単に２種の平均粒子径の熱伝導性粒子を配合するのみでは、十分に密に充填することができず、さらなる熱伝導性の向上が望まれている。 However, it is not possible to pack the particles sufficiently densely by simply blending heat conductive particles having two kinds of average particle diameters, and further improvement in heat conductivity is desired.
　また、熱伝導性粒子が密に充填されることにより、熱伝導性粒子が粘着シート内で接触または干渉し、過度に粘着シートの硬度が高くなる場合がある。そうすると、適度な柔らかさが求められる粘着シートとして不具合が生じる。 In addition, when the heat conductive particles are densely packed, the heat conductive particles may contact or interfere with each other in the pressure sensitive adhesive sheet, and the hardness of the pressure sensitive adhesive sheet may be excessively increased. If it does so, a malfunction will arise as an adhesive sheet in which moderate softness is calculated | required.
　そこで、本発明の目的は、熱伝導性に優れ、良好な硬度（適度な柔らかさ）を備える熱伝導性粘着シートおよびその製造方法を提供することにある。 Therefore, an object of the present invention is to provide a heat conductive pressure-sensitive adhesive sheet having excellent heat conductivity and good hardness (appropriate softness) and a method for producing the same.
　本発明の熱伝導性粘着シートは、アクリル系粘着剤層を備え、前記アクリル系粘着剤層は、平均粒子径が異なる３種以上の熱伝導性粒子を含有し、前記３種以上の熱伝導性粒子を混合したときの空間率が、７２％以下であり、前記アクリル系粘着剤層に対する前記３種以上の熱伝導性粒子の含有割合が、５５体積％以上７５体積％以下であることを特徴としている。 The heat conductive adhesive sheet of this invention is equipped with the acrylic adhesive layer, The said acrylic adhesive layer contains 3 or more types of heat conductive particles from which an average particle diameter differs, The said 3 or more types of heat conduction The space ratio when the conductive particles are mixed is 72% or less, and the content ratio of the three or more kinds of thermally conductive particles with respect to the acrylic pressure-sensitive adhesive layer is 55% by volume or more and 75% by volume or less. It is a feature.
　また、本発明の熱伝導性粘着シートは、前記３種以上の熱伝導性粒子のうち少なくとも１種の熱伝導性粒子は、金属酸化物または金属窒化物からなり、それ以外の熱伝導性粒子は、金属水酸化物からなることが好適である。 Further, in the heat conductive adhesive sheet of the present invention, at least one of the three or more heat conductive particles is made of a metal oxide or a metal nitride, and the other heat conductive particles. Is preferably made of a metal hydroxide.
　本発明の熱伝導性粘着シートは、前記金属酸化物または金属窒化物からなる熱伝導性粒子の含有割合が、前記アクリル系粘着剤層に対して、５体積％以上２５体積％以下であることが好適である。 In the thermally conductive adhesive sheet of the present invention, the content ratio of the thermally conductive particles made of the metal oxide or metal nitride is 5% by volume or more and 25% by volume or less with respect to the acrylic adhesive layer. Is preferred.
　本発明の熱伝導性粘着シートは、前記３種類以上の熱伝導性粒子が、平均粒子径３μｍ未満の第１熱伝導性粒子、平均粒子径３μｍ以上７０μｍ未満の第２熱伝導性粒子、および、平均粒子径７０μｍ以上の第３熱伝導性粒子を含有することが好適である。 In the heat conductive pressure-sensitive adhesive sheet of the present invention, the three or more kinds of heat conductive particles are first heat conductive particles having an average particle diameter of less than 3 μm, second heat conductive particles having an average particle diameter of 3 μm or more and less than 70 μm, and It is preferable to contain third heat conductive particles having an average particle diameter of 70 μm or more.
　本発明の熱伝導性粘着シートは、前記３種類以上の熱伝導性粒子が、平均粒子径３μｍ未満の第１熱伝導性粒子、平均粒子径３μｍ以上７０μｍ未満の第２熱伝導性粒子、および、平均粒子径３μｍ以上７０μｍ未満で鱗片状である第４熱伝導性粒子を含有することが好適である。 In the heat conductive pressure-sensitive adhesive sheet of the present invention, the three or more kinds of heat conductive particles are first heat conductive particles having an average particle diameter of less than 3 μm, second heat conductive particles having an average particle diameter of 3 μm or more and less than 70 μm, and It is preferable to contain the 4th heat conductive particle which is a scaly shape with an average particle diameter of 3 micrometers or more and less than 70 micrometers.
　本発明の熱伝導性粘着シートでは、前記アクリル系粘着剤層は、（メタ）アクリル酸アルキルエステルを主成分とし、極性基含有モノマーを５質量％以上含有するモノマー成分を重合することにより得られるアクリル系ポリマーを含有することが好適である。 In the heat conductive adhesive sheet of this invention, the said acrylic adhesive layer is obtained by superposing | polymerizing the monomer component which has (meth) acrylic-acid alkylester as a main component and contains 5 mass% or more of polar group containing monomers. It is preferable to contain an acrylic polymer.
　本発明の熱伝導性粘着シートでは、前記モノマー成分は、カルボキシル基を有するモノマーを実質的に含まないことが好適である。 In the thermally conductive adhesive sheet of the present invention, it is preferable that the monomer component does not substantially contain a monomer having a carboxyl group.
　本発明の熱伝導性粘着シートでは、前記極性基含有モノマーは、窒素含有モノマーおよび／または水酸基含有モノマーを含有することが好適である。 In the thermally conductive pressure-sensitive adhesive sheet of the present invention, it is preferable that the polar group-containing monomer contains a nitrogen-containing monomer and / or a hydroxyl group-containing monomer.
　本発明の熱伝導性粘着シートは、前記熱伝導性粘着シートの硬度が、タイプＣ硬さ試験において、タイプＣデュロメータの加圧面を密着させてから３０秒後に測定したときに、８０以下であることが好適である。 In the heat conductive pressure-sensitive adhesive sheet of the present invention, the hardness of the heat conductive pressure-sensitive adhesive sheet is 80 or less when measured 30 seconds after the pressure surface of the type C durometer is brought into close contact in a type C hardness test. Is preferred.
　本発明の熱伝導性粘着シートは、前記熱伝導性粘着シートの厚み方向における熱伝導率が、１．７Ｗ／ｍ・Ｋ以上であることが好適である。 The heat conductive pressure-sensitive adhesive sheet of the present invention preferably has a heat conductivity of 1.7 W / m · K or more in the thickness direction of the heat conductive pressure-sensitive adhesive sheet.
　本発明の熱伝導性粘着シートでは、前記熱伝導性粘着シートは、ＵＬ９４難燃性試験において、Ｖ－０規格を満たすことが好適である。 In the heat conductive pressure-sensitive adhesive sheet of the present invention, it is preferable that the heat conductive pressure-sensitive adhesive sheet satisfies the V-0 standard in the UL94 flame retardant test.
　本発明の熱伝導性粘着シートの製造方法は、アクリル系粘着剤層を備える熱伝導性粘着シートの製造する方法であって、（メタ）アクリル酸アルキルエステルを主成分とするモノマー成分に、平均粒子径が異なる３種以上である熱伝導性粒子を混合して、粘着剤原料を得る工程、および前記粘着剤原料を反応させ、前記アクリル系粘着剤層を得る工程を備え、前記３種以上の熱伝導性粒子を混合したときの空間率が、７２％以下であり、前記アクリル系粘着剤層に対する前記３種以上の熱伝導性粒子の含有割合が、５５体積％以上７５体積％以下であることを特徴している。 The manufacturing method of the heat conductive adhesive sheet of this invention is a method of manufacturing a heat conductive adhesive sheet provided with an acrylic adhesive layer, Comprising: It is an average to the monomer component which has (meth) acrylic-acid alkylester as a main component. Mixing three or more kinds of thermally conductive particles having different particle diameters to obtain a pressure-sensitive adhesive raw material, and reacting the pressure-sensitive adhesive raw material to obtain the acrylic pressure-sensitive adhesive layer. When the heat conductive particles are mixed, the space ratio is 72% or less, and the content ratio of the three or more heat conductive particles with respect to the acrylic pressure-sensitive adhesive layer is 55% by volume to 75% by volume. It is characterized by being.
　本発明の熱伝導性粘着シートによれば、アクリル系粘着剤層を備え、アクリル系粘着剤層は、平均粒子径が異なる３種以上の熱伝導性粒子を含有し、３種以上の熱伝導性粒子を混合したときの空間率が、７２％以下であり、アクリル系粘着剤に対する前記３種以上の熱伝導性粒子の含有割合が、５５体積％以上７５体積％以下である。 According to the thermally conductive pressure-sensitive adhesive sheet of the present invention, an acrylic pressure-sensitive adhesive layer is provided, and the acrylic pressure-sensitive adhesive layer contains three or more kinds of heat conductive particles having different average particle diameters, and three or more kinds of heat conduction. When the conductive particles are mixed, the space ratio is 72% or less, and the content ratio of the three or more kinds of thermally conductive particles with respect to the acrylic pressure-sensitive adhesive is 55% by volume or more and 75% by volume or less.
　そのため、本発明の熱伝導性粘着シートは、厚み方向の熱伝導性に優れ、良好な硬度を有する。 Therefore, the heat conductive adhesive sheet of the present invention is excellent in heat conductivity in the thickness direction and has a good hardness.
　また、本発明の熱伝導性粘着シートの製造方法によれば、熱伝導性に優れ、良好な硬度を有する熱伝導性粘着シートを簡便に製造することができる。 Further, according to the method for producing a heat conductive pressure-sensitive adhesive sheet of the present invention, a heat conductive pressure-sensitive adhesive sheet having excellent heat conductivity and good hardness can be easily produced.
図１は、熱伝導性粘着シートの作製方法を説明する説明図であって、図１（ａ）は、ベースフィルムの上に粘着剤原料を塗布する工程を示し、図１（ｂ）は、粘着剤原料の塗膜の上にカバーフィルムを配置する工程を示し、図１（ｃ）は、粘着剤原料を反応させる工程を示す。FIG. 1 is an explanatory view for explaining a method for producing a heat conductive pressure-sensitive adhesive sheet, in which FIG. 1 (a) shows a step of applying a pressure-sensitive adhesive material on a base film, and FIG. The process of arrange | positioning a cover film on the coating film of an adhesive raw material is shown, and FIG.1 (c) shows the process of making an adhesive raw material react.
発明の実施形態Embodiment of the Invention
　本発明の熱伝導性粘着シートは、モノマー成分および／またはポリマー成分と、熱伝導性粒子とを含有している粘着剤原料からシート状に形成されている。 The heat conductive pressure-sensitive adhesive sheet of the present invention is formed into a sheet shape from a pressure-sensitive adhesive raw material containing a monomer component and / or a polymer component and heat conductive particles.
　モノマー成分としては、例えば、必須成分として、（メタ）アクリル酸アルキルエステルモノマーが挙げられ、任意成分として、極性基含有モノマー、これらのモノマーと共重合可能な共重合可能モノマーが挙げられる。 Examples of the monomer component include (meth) acrylic acid alkyl ester monomers as essential components, and optional components include polar group-containing monomers and copolymerizable monomers copolymerizable with these monomers.
　（メタ）アクリル酸アルキルエステルモノマーとしては、メタクリル酸アルキルエステルモノマーおよび／またはアクリル酸アルキルエステルモノマーであって、例えば、（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸プロピル、（メタ）アクリル酸イソプロピル、（メタ）アクリル酸ブチル、（メタ）アクリル酸イソブチル、（メタ）アクリル酸ｓ－ブチル、（メタ）アクリル酸ｔ－ブチル、（メタ）アクリル酸ペンチル、（メタ）アクリル酸イソペンチル、（メタ）アクリル酸ヘキシル、（メタ）アクリル酸ヘプチル、（メタ）アクリル酸オクチル、（メタ）アクリル酸２－エチルヘキシル、（メタ）アクリル酸イソオクチル、（メタ）アクリル酸ノニル、（メタ）アクリル酸イソノニル、（メタ）アクリル酸デシル、（メタ）アクリル酸イソデシル、（メタ）アクリル酸ウンデシル、（メタ）アクリル酸ドデシル、（メタ）アクリル酸トリデシル、（メタ）アクリル酸テトラデシル、（メタ）アクリル酸ペンタデシル、（メタ）アクリル酸ヘキサデシル、（メタ）アクリル酸ヘプタデシル、（メタ）アクリル酸オクタデシル、（メタ）アクリル酸ノナデシル、（メタ）アクリル酸エイコシルなどが挙げられる。 Examples of (meth) acrylic acid alkyl ester monomers include methacrylic acid alkyl ester monomers and / or acrylic acid alkyl ester monomers, such as methyl (meth) acrylate, ethyl (meth) acrylate, and propyl (meth) acrylate. Isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, (meth) Isopentyl acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, (meth ) Isononyl acrylate, (meth) ac Decyl lurate, isodecyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, (meth) acrylic Examples include hexadecyl acid, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate, and the like.
　これらの（メタ）アクリル酸アルキルエステルモノマーのうち、特に接着特性のバランスを取りやすい点から、好ましくは、（メタ）アクリル酸Ｃ２－１２アルキルエステル、より好ましくは、（メタ）アクリル酸Ｃ４－９アルキルエステルが挙げられる。 Among these (meth) acrylic acid alkyl ester monomers, (meth) acrylic acid C2-12 alkyl ester is preferred, and (meth) acrylic acid C4-9 is more preferred, particularly from the viewpoint of easily balancing the adhesive properties. Examples include alkyl esters.
　（メタ）アクリル酸アルキルエステルモノマーは、モノマー成分中に、例えば、６０質量％以上、好ましくは、８０質量％以上、例えば、９９質量％以下の割合で配合される。 The (meth) acrylic acid alkyl ester monomer is blended in the monomer component in a proportion of, for example, 60% by mass or more, preferably 80% by mass or more, for example, 99% by mass or less.
　極性基含有モノマーとしては、例えば、窒素含有モノマー、水酸基含有モノマー、スルホ基含有モノマー、窒素・水酸基併有モノマー、窒素・スルホ基併有モノマー、水酸基・リン酸基併有モノマー、カルボキシル基含有モノマーなどが挙げられる。 Examples of polar group-containing monomers include nitrogen-containing monomers, hydroxyl group-containing monomers, sulfo group-containing monomers, nitrogen / hydroxyl group-containing monomers, nitrogen / sulfo group-containing monomers, hydroxyl group / phosphate group-containing monomers, and carboxyl group-containing monomers. Etc.
　窒素含有モノマーとしては、例えば、Ｎ－（メタ）アクリロイルモルホリン、Ｎ－アクリロイルピロリジンなどの環状（メタ）アクリルアミド、例えば、（メタ）アクリルアミド、Ｎ－置換（メタ）アクリルアミド（例えば、Ｎ－エチル（メタ）アクリルアミド、Ｎ－ｎ－ブチル（メタ）アクリルアミドなどのＮ－アルキル（メタ）アクリルアミド、例えば、Ｎ，Ｎ－ジメチル（メタ）アクリルアミド、Ｎ，Ｎ－ジエチル（メタ）アクリルアミド、Ｎ，Ｎ－ジプロピル（メタ）アクリルアミド、Ｎ，Ｎ－ジイソプロピル（メタ）アクリルアミド、Ｎ，Ｎ－ジ（ｎ－ブチル）（メタ）アクリルアミド、Ｎ，Ｎ－ジ（ｔ－ブチル）（メタ）アクリルアミドなどのＮ，Ｎ－ジアルキル（メタ）アクリルアミド）などの非環状（メタ）アクリルアミド、例えば、Ｎ－ビニル－２－ピロリドン（ＮＶＰ）、Ｎ－ビニル－２－ピペリドン、Ｎ－ビニル－３－モルホリノン、Ｎ－ビニル－２－カプロラクタム、Ｎ－ビニル－１，３－オキサジン－２－オン、Ｎ－ビニル－３，５－モルホリンジオンなどのＮ－ビニル環状アミド、例えば、アミノエチル（メタ）アクリレート、Ｎ，Ｎ－ジメチルアミノエチル（メタ）アクリレート、Ｎ，Ｎ－ジメチルアミノプロピル（メタ）アクリレートなどのアミノ基含有モノマー、例えば、Ｎ－シクロヘキシルマレイミド、Ｎ－フェニルマレイミドなどのマレイミド骨格含有モノマー、例えば、Ｎ－メチルイタコンイミド、Ｎ－エチルイタコンイミド、Ｎ－ブチルイタコンイミド、Ｎ－２－エチルヘキシルイタコンイミド、Ｎ－ラウリルイタコンイミド、Ｎ－シクロヘキシルイタコンイミドなどのイタコンイミド系モノマーなどが挙げられる。 Examples of the nitrogen-containing monomer include cyclic (meth) acrylamides such as N- (meth) acryloylmorpholine and N-acryloylpyrrolidine, such as (meth) acrylamide, N-substituted (meth) acrylamide (eg, N-ethyl (meth) ) Acrylamide, N-alkyl (meth) acrylamides such as Nn-butyl (meth) acrylamide, for example, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-dipropyl ( N, N-dialkyl such as (meth) acrylamide, N, N-diisopropyl (meth) acrylamide, N, N-di (n-butyl) (meth) acrylamide, N, N-di (t-butyl) (meth) acrylamide (Meth) acrylamide) and other non-cyclic (meth) acrylamids For example, N-vinyl-2-pyrrolidone (NVP), N-vinyl-2-piperidone, N-vinyl-3-morpholinone, N-vinyl-2-caprolactam, N-vinyl-1,3-oxazine-2- ON, N-vinyl cyclic amides such as N-vinyl-3,5-morpholinedione such as aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, N, N-dimethylaminopropyl (meta ) Amino group-containing monomers such as acrylates, for example, maleimide skeleton-containing monomers such as N-cyclohexylmaleimide, N-phenylmaleimide, such as N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-2 -Ethylhexylitaconimide, N-laurylitaconimide, N- Such itaconimide monomers such as black hexyl itaconic imide.
　水酸基含有モノマーとしては、例えば、（メタ）アクリル酸２－ヒドロキシエチル、（メタ）アクリル酸３－ヒドロキシプロピル、（メタ）アクリル酸４－ヒドロキシブチル、（メタ）アクリル酸６－ヒドロキシヘキシル、（メタ）アクリル酸８－ヒドロキシオクチル、（メタ）アクリル酸１０－ヒドロキシデシル、（メタ）アクリル酸１２－ヒドロキシラウリル、（４－ヒドロキシメチルシクロへキシル）メチルメタクリレートなどが挙げられる。 Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, (meth ) 8-hydroxyoctyl acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl methacrylate, and the like.
　スルホ基含有モノマーとしては、例えば、スチレンスルホン酸、アリルスルホン酸、スルホプロピル（メタ）アクリレート、（メタ）アクリロイルオキシナフタレンスルホン酸などが挙げられる。 Examples of the sulfo group-containing monomer include styrene sulfonic acid, allyl sulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid, and the like.
　窒素・水酸基併有モノマーとしては、例えば、Ｎ－（２－ヒドロキシエチル）（メタ）アクリルアミド（ＨＥＡＡ）、Ｎ－（２－ヒドロキシプロピル）（メタ）アクリルアミド、Ｎ－（１－ヒドロキシプロピル）（メタ）アクリルアミド、Ｎ－（３－ヒドロキシプロピル）（メタ）アクリルアミド、Ｎ－（２－ヒドロキシブチル）（メタ）アクリルアミド、Ｎ－（３－ヒドロキシブチル）（メタ）アクリルアミド、Ｎ－（４－ヒドロキシブチル）（メタ）アクリルアミドなどのＮ－ヒドロキシアルキル（メタ）アクリルアミドが挙げられる。 Examples of the nitrogen / hydroxyl monomer include N- (2-hydroxyethyl) (meth) acrylamide (HEAA), N- (2-hydroxypropyl) (meth) acrylamide, and N- (1-hydroxypropyl) (meta). ) Acrylamide, N- (3-hydroxypropyl) (meth) acrylamide, N- (2-hydroxybutyl) (meth) acrylamide, N- (3-hydroxybutyl) (meth) acrylamide, N- (4-hydroxybutyl) N-hydroxyalkyl (meth) acrylamides such as (meth) acrylamide can be mentioned.
　窒素・スルホ基併有モノマーとしては、例えば、２－（メタ）アクリルアミド－２－メチルプロパンスルホン酸、（メタ）アクリルアミドプロパンスルホン酸などが挙げられる。 Examples of the nitrogen / sulfo group-containing monomer include 2- (meth) acrylamide-2-methylpropanesulfonic acid and (meth) acrylamidepropanesulfonic acid.
　水酸基・リン酸基併有モノマーとしては、例えば、２－ヒドロキシエチルアクリロイルホスフェートなどが挙げられる。 Examples of the hydroxyl group / phosphate group-containing monomer include 2-hydroxyethyl acryloyl phosphate.
　カルボキシル基含有モノマーとしては、例えば、（メタ）アクリル酸、イタコン酸、マレイン酸、フマル酸、クロトン酸、イソクロトン酸、無水マレイン酸、無水イタコン酸などが挙げられる。 Examples of the carboxyl group-containing monomer include (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, maleic anhydride, itaconic anhydride, and the like.
　これらの極性基含有モノマーのうち、粘着剤層（後述）に高い接着性と保持力を付与するという点から、好ましくは、窒素含有モノマー、水酸基含有モノマー、窒素・水酸基含有モノマーが挙げられ、より好ましくは、Ｎ－ビニル－２－ピロリドン、Ｎ－（メタ）アクリロイルモルホリン、Ｎ，Ｎ－ジエチル（メタ）アクリルアミド、（メタ）アクリル酸ヒドロキシエチル、（メタ）アクリル酸ヒドロキシブチル、Ｎ－（２－ヒドロキシエチル）（メタ）アクリルアミドが挙げられる。 Among these polar group-containing monomers, from the viewpoint of imparting high adhesiveness and holding power to the pressure-sensitive adhesive layer (described later), nitrogen-containing monomers, hydroxyl group-containing monomers, nitrogen / hydroxyl group-containing monomers are preferred, and more Preferably, N-vinyl-2-pyrrolidone, N- (meth) acryloylmorpholine, N, N-diethyl (meth) acrylamide, hydroxyethyl (meth) acrylate, hydroxybutyl (meth) acrylate, N- (2- Hydroxyethyl) (meth) acrylamide.
　極性基含有モノマーは、モノマー成分中に、例えば、１質量％以上、好ましくは、５質量％以上、また、例えば、３０質量％以下、好ましくは、２５質量％以下の割合で配合される。極性基含有モノマーの配合割合が上記範囲内であると、粘着剤層に良好な保持力を付与することができる。 The polar group-containing monomer is blended in the monomer component in a proportion of, for example, 1% by mass or more, preferably 5% by mass or more, and for example, 30% by mass or less, preferably 25% by mass or less. When the blending ratio of the polar group-containing monomer is within the above range, good holding power can be imparted to the pressure-sensitive adhesive layer.
　なお、モノマー成分中に、好ましくは、カルボキシル基含有モノマーは、実質的に含まない。具体的には、カルボキシル基含有モノマーの配合割合は、モノマー成分中に、例えば、５質量％以下、好ましくは、１質量％以下、さらに好ましくは、０．５質量％以下である。カルボキシル基含有モノマーの配合割合が上記範囲内であると、熱伝導性粒子をゲル化することなく分散することができる。 The monomer component preferably contains substantially no carboxyl group-containing monomer. Specifically, the mixing ratio of the carboxyl group-containing monomer is, for example, 5% by mass or less, preferably 1% by mass or less, and more preferably 0.5% by mass or less in the monomer component. When the blending ratio of the carboxyl group-containing monomer is within the above range, the heat conductive particles can be dispersed without gelation.
　共重合可能モノマーとしては、例えば、グリシジル（メタ）アクリレート、アリルグリシジルエーテルなどのエポキシ基含有モノマー、例えば、（メタ）アクリル酸２－メトキシエチル、（メタ）アクリル酸３－メトキシプロピル、（メタ）アクリル酸メトキシエチレングリコール、（メタ）アクリル酸メトキシポリプロピレングリコールなどのアルコキシ基含有モノマー、例えば、アクリロニトリル、メタクリロニトリルなどのシアノ基含有モノマー、例えば、スチレン、α－メチルスチレンなどのスチレン系モノマー、例えば、エチレン、プロピレン、イソプレン、ブタジエン、イソブチレンなどのα－オレフィン、例えば、２－イソシアナートエチルアクリレート、２－イソシアナートエチルメタクリレートなどのイソシアネート基含有モノマー、例えば、酢酸ビニル、プロピオン酸ビニルなどのビニルエステル系モノマー、例えば、アルキルビニルエーテルなどのビニルエーテル系モノマー、例えば、テトラヒドロフルフリル（メタ）アクリレートなどの複素環含有（メタ）アクリル酸エステル、例えば、フルオロアルキル（メタ）アクリレートなどのハロゲン原子含有モノマー、例えば、３－メタクリロキシプロピルトリメトキシシラン、ビニルトリメトキシシランなどのアルコキシシリル基含有モノマー、例えば、（メタ）アクリル基含有シリコーンなどのシロキサン骨格含有モノマー、例えば、シクロペンチル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、ボルニル（メタ）アクリレート、イソボルニル（メタ）アクリレートなどの脂環式炭化水素基含有（メタ）アクリレート、例えば、フェニル（メタ）アクリレート、ベンジル（メタ）アクリレート、フェノキシエチル（メタ）アクリレート、（メタ）アクリル酸フェノキシジエチレングリコールなどの芳香族炭化水素基含有（メタ）アクリレートなどが挙げられる。 Examples of the copolymerizable monomer include epoxy group-containing monomers such as glycidyl (meth) acrylate and allyl glycidyl ether, such as 2-methoxyethyl (meth) acrylate, 3-methoxypropyl (meth) acrylate, (meth) Alkoxy group-containing monomers such as methoxyethylene glycol acrylate and methoxypolypropylene glycol (meth) acrylate, cyano group-containing monomers such as acrylonitrile and methacrylonitrile, styrene monomers such as styrene and α-methylstyrene, Α-olefins such as ethylene, propylene, isoprene, butadiene and isobutylene, for example, isocyanate groups such as 2-isocyanatoethyl acrylate and 2-isocyanatoethyl methacrylate Monomers, for example, vinyl ester monomers such as vinyl acetate and vinyl propionate, vinyl ether monomers such as alkyl vinyl ether, heterocycle-containing (meth) acrylic esters such as tetrahydrofurfuryl (meth) acrylate, A halogen atom-containing monomer such as fluoroalkyl (meth) acrylate, for example, an alkoxysilyl group-containing monomer such as 3-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, or a siloxane skeleton such as a (meth) acryl group-containing silicone Containing alicyclic hydrocarbons such as cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, bornyl (meth) acrylate, isobornyl (meth) acrylate Containing (meth) acrylates, for example, phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, (meth) acrylic acid phenoxydiethylene glycol-containing (meth) acrylate, etc. .
　これらの共重合可能モノマーのうち、好ましくは、アルコキシ基含有モノマー、より好ましくは、アクリル酸２－メトキシエチルが挙げられる。アルコキシ基含有モノマーを配合することで、粘着剤層の被着体に対する密着性を向上させることができ、被着体からの熱を効率よく伝導させることができる。 Of these copolymerizable monomers, an alkoxy group-containing monomer is preferable, and 2-methoxyethyl acrylate is more preferable. By mix | blending an alkoxy group containing monomer, the adhesiveness with respect to the adherend of an adhesive layer can be improved, and the heat | fever from an adherend can be conducted efficiently.
　共重合可能モノマーは、モノマー成分中に、例えば、３０質量％以下、好ましくは、２０質量％以下、また、例えば、１質量％以上、好ましくは、５質量％以上の割合で配合される。 The copolymerizable monomer is blended in the monomer component, for example, at a ratio of 30% by mass or less, preferably 20% by mass or less, for example, 1% by mass or more, preferably 5% by mass or more.
　これらのモノマーは、単独（１種類のみ）で使用することもでき、また、２種以上組み合わせて使用することもできる。 These monomers can be used alone (only one kind) or in combination of two or more kinds.
　また、モノマー成分は、粘着剤原料中に、例えば、１質量％以上、好ましくは、５質量％以上、より好ましくは、１０質量％以上、また、例えば、９０質量％以下、好ましくは、６０質量％以下、さらに好ましくは、５０質量％以下の割合で配合される。 Further, the monomer component is, for example, 1% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, for example, 90% by mass or less, preferably 60% by mass in the pressure-sensitive adhesive raw material. % Or less, more preferably 50% by mass or less.
　ポリマー成分としては、例えば、上記したモノマー成分を反応させて得られる重合体（ポリマー）が挙げられる。詳しくは、ポリマーとしては、特に制限されないが、例えば、アクリルポリマー、より詳しくは、必須成分として、（メタ）アクリル酸アルキルエステルモノマーが用いられ、任意成分として、極性基含有モノマー、これらのモノマーと共重合可能な共重合可能モノマーが用いられたアクリル重合体などが挙げられる。なお、ポリマーには、上記したモノマーの一部重合物が含まれる。 Examples of the polymer component include a polymer (polymer) obtained by reacting the monomer component described above. Specifically, the polymer is not particularly limited, but, for example, an acrylic polymer, more specifically, a (meth) acrylic acid alkyl ester monomer is used as an essential component, and as an optional component, a polar group-containing monomer, these monomers and Examples thereof include acrylic polymers using copolymerizable monomers that can be copolymerized. The polymer includes a partially polymerized monomer as described above.
　これらのポリマーは、単独（１種類のみ）で使用することもでき、また、２種以上組み合わせて使用することもできる。 These polymers can be used alone (only one kind) or in combination of two or more kinds.
　ポリマー成分は、粘着剤原料中に、例えば、１質量％以上、好ましくは、５質量％以上、より好ましくは、１０質量％以上、また、例えば、５０質量％以下、好ましくは、４０質量％以下、さらに好ましくは、３０質量％以下の割合で配合される。 The polymer component is, for example, 1% by mass or more, preferably 5% by mass or more, more preferably 10% by mass or more, for example, 50% by mass or less, preferably 40% by mass or less in the pressure-sensitive adhesive raw material. More preferably, it mix | blends in the ratio of 30 mass% or less.
　なお、粘着剤原料にモノマー成分およびポリマー成分の両方が配合される場合、モノマー成分及びポリマー成分は、粘着剤原料中に、その総量が、例えば、１質量％以上、好ましくは、５質量％以上、より好ましくは、１０質量％以上、また、例えば、５０質量％以下、好ましくは、４０質量％以下、さらに好ましくは、３０質量％以下の割合となるように、配合される。 When both the monomer component and the polymer component are blended in the pressure-sensitive adhesive material, the total amount of the monomer component and the polymer component in the pressure-sensitive adhesive material is, for example, 1% by mass or more, preferably 5% by mass or more. More preferably, it is blended so that the ratio is 10% by mass or more, for example, 50% by mass or less, preferably 40% by mass or less, and more preferably 30% by mass or less.
　熱伝導性粒子としては、例えば、水和金属化合物などが挙げられる。 Examples of the heat conductive particles include hydrated metal compounds.
　水和金属化合物は、分解開始温度が１５０～５００℃の範囲であり、一般式ＭｘＯｙ・ｎＨ２Ｏ（Ｍは金属原子、ｘ，ｙは金属の原子価によって定まる１以上の整数、ｎは含有結晶水の数）で表される化合物または上記化合物を含む複塩である。 The hydrated metal compound has a decomposition start temperature in the range of 150 to 500 ° C., and has a general formula MxOy · nH 2 O (M is a metal atom, x and y are integers of 1 or more determined by the valence of the metal, and n is contained) Or a double salt containing the above compound.
　水和金属化合物としては、例えば、水酸化アルミニウム［Ａｌ２Ｏ３・３Ｈ２Ｏ；またはＡｌ（ＯＨ）３］、ベーマイト［Ａｌ２Ｏ３・Ｈ２Ｏ；またはＡｌＯＯＨ］、水酸化マグネシウム［ＭｇＯ・Ｈ２Ｏ；またはＭｇ（ＯＨ）２］、水酸化カルシウム［ＣａＯ・Ｈ２Ｏ；またはＣａ（ＯＨ）２］、水酸化亜鉛［Ｚｎ（ＯＨ）２］、珪酸［Ｈ４ＳｉＯ４；またはＨ２ＳｉＯ３；またはＨ２Ｓｉ２Ｏ５］、水酸化鉄［Ｆｅ２Ｏ３・Ｈ２Ｏまたは２ＦｅＯ（ＯＨ）］、水酸化銅［Ｃｕ（ＯＨ）２］、水酸化バリウム［ＢａＯ・Ｈ２Ｏ；またはＢａＯ・９Ｈ２Ｏ］、酸化ジルコニウム水和物［ＺｒＯ・ｎＨ２Ｏ］、酸化スズ水和物［ＳｎＯ・Ｈ２Ｏ］、塩基性炭酸マグネシウム［３ＭｇＣＯ３・Ｍｇ（ＯＨ）２・３Ｈ２Ｏ］、ハイドロタルサイト［６ＭｇＯ・Ａｌ２Ｏ３・Ｈ２Ｏ］、ドウソナイト［Ｎａ２ＣＯ３・Ａｌ２Ｏ３・ｎＨ２Ｏ］、硼砂［Ｎａ２Ｏ・Ｂ２Ｏ５・５Ｈ２Ｏ］、ホウ酸亜鉛［２ＺｎＯ・３Ｂ２Ｏ５・３．５Ｈ２Ｏ］などが挙げられる。 Examples of the hydrated metal compound include aluminum hydroxide [Al 2 O 3 .3H 2 O; or Al (OH) 3 ], boehmite [Al 2 O 3 .H 2 O; or AlOOH], magnesium hydroxide [MgO H 2 O; or Mg (OH) 2 ], calcium hydroxide [CaO · H 2 O; or Ca (OH) 2 ], zinc hydroxide [Zn (OH) 2 ], silicic acid [H 4 SiO 4 ; H 2 SiO 3 ; or H 2 Si 2 O 5 ], iron hydroxide [Fe 2 O 3 .H 2 O or 2FeO (OH)], copper hydroxide [Cu (OH) 2 ], barium hydroxide [BaO. H 2 O; or BaO · 9H 2 O], zirconium oxide hydrate [ZrO · nH 2 O], tin oxide hydrate [SnO · H 2 O], basic magnesium carbonate [3MgCO 3 · Mg (OH) · 3H 2 O], hydrotalcite [6MgO · Al 2 O 3 · H 2 O], dawsonite [Na 2 CO 3 · Al 2 O 3 · nH 2 O], borax [Na 2 O · B 2 O 5 · 5H 2 O], zinc borate [2ZnO · 3B 2 O 5 · 3.5H 2 O] and the like.
　水和金属化合物は、市販されており、例えば、水酸化アルミニウムとして、商品名「ハイジライトＨ－１００－ＭＥ」（平均粒子径７５μｍ）（昭和電工社製）、商品名「ハイジライトＨ－１０」（平均粒子径５５μｍ）（昭和電工社製）、商品名「ハイジライトＨ－３２」（平均粒子径８μｍ）（昭和電工社製）、商品名「ハイジライトＨ－３１」（平均粒子径１８μｍ）（昭和電工社製）、商品名「ハイジライトＨ－４２」（平均粒子径１μｍ）（昭和電工社製）、商品名「Ｂ１０３ＳＴ」（平均粒子径８μｍ）（日本軽金属社製）、商品名「ＢＥ０３３Ｔ」（平均粒子径３μｍ）（日本軽金属社製）など、例えば、水酸化マグネシウムとして、商品名「ＫＩＳＵＭＡ　５Ａ」（平均粒子径１μｍ）（協和化学工業社製）などが挙げられる。 Hydrated metal compounds are commercially available. For example, as aluminum hydroxide, the trade name “Hijilite H-100-ME” (average particle size 75 μm) (manufactured by Showa Denko KK), the trade name “Hijilite H-10” is available. (Average particle size 55 μm) (made by Showa Denko KK), trade name “Hijilite H-32” (average particle size 8 μm) (Showa Denko), trade name “Hijilite H-31” (average particle size 18 μm) ) (Manufactured by Showa Denko KK), trade name “Hijilite H-42” (average particle diameter 1 μm) (Showa Denko KK), trade name “B103ST” (average particle diameter 8 μm) (manufactured by Nippon Light Metal Co., Ltd.), trade name “BE033T” (average particle diameter 3 μm) (manufactured by Nippon Light Metal Co., Ltd.) and the like, for example, as magnesium hydroxide, trade name “KISUMA 5A” (average particle diameter 1 μm) (manufactured by Kyowa Chemical Industry Co., Ltd.) and the like.
　また、熱伝導性粒子としては、上記した水和金属化合物の他に、例えば、窒化ホウ素、窒化アルミニウム、窒化ケイ素、窒化ガリウムなどの金属窒化物、例えば、二酸化ケイ素、酸化アルミニウム、酸化マグネシウム、酸化チタン、酸化亜鉛、酸化スズ、酸化銅、酸化ニッケルなどの金属酸化物、例えば、炭化ケイ素、アンチモン酸ドープ酸化スズ、炭酸カルシウム、チタン酸バリウム、チタン酸カリウム、銅、銀、金、ニッケル、アルミニウム、白金、カーボンブラック、カーボンチューブ（カーボンナノチューブ）、カーボンファイバー、ダイヤモンドなどが挙げられる。 In addition to the above hydrated metal compounds, the thermally conductive particles include, for example, metal nitrides such as boron nitride, aluminum nitride, silicon nitride, and gallium nitride, such as silicon dioxide, aluminum oxide, magnesium oxide, and oxide. Metal oxides such as titanium, zinc oxide, tin oxide, copper oxide, nickel oxide, such as silicon carbide, antimonic acid doped tin oxide, calcium carbonate, barium titanate, potassium titanate, copper, silver, gold, nickel, aluminum Platinum, carbon black, carbon tube (carbon nanotube), carbon fiber, diamond and the like.
　これらの熱伝導性粒子は、市販されており、例えば、窒化ホウ素として、商品名「ＨＰ－４０」（水島合金鉄社製）、商品名「ＰＴ１１０」（平均粒子径３５μｍ）（モメンティブ社製）、商品名「ＰＴ６２０」（モメンティブ社製）など、例えば、酸化アルミニウムとして、商品名「ＡＬ－１３ＫＴ」（平均粒子径９７μｍ）（昭和電工社製）、商品名「ＡＳ－５０」（昭和電工社製）、商品名「ＡＳ－１０」（昭和電工社製）など、例えば、アンチモン酸ドープスズとして、商品名「ＳＮ－１００Ｓ」（石原産業社製）、商品名「ＳＮ－１００Ｐ」（石原産業社製）、商品名「ＳＮ－１００Ｄ（水分散品）」（石原産業社製）など、例えば、酸化チタンとして、商品名「ＴＴＯシリーズ」（石原産業社製）など、例えば、酸化亜鉛として、商品名「ＳｎＯ－３１０」（住友大阪セメント社製）、商品名「ＳｎＯ－３５０」（住友大阪セメント社製）、商品名「ＳｎＯ－４１０」（住友大阪セメント社製）などが挙げられる。 These thermally conductive particles are commercially available, for example, as boron nitride, trade name “HP-40” (manufactured by Mizushima Alloy Iron Co., Ltd.), trade name “PT110” (average particle size 35 μm) (manufactured by Momentive) For example, the product name “AL-13KT” (average particle size 97 μm) (manufactured by Showa Denko), the product name “AS-50” (Showa Denko) Product name “AS-10” (manufactured by Showa Denko KK), for example, as antimonic acid doped tin, the product name “SN-100S” (manufactured by Ishihara Sangyo Co., Ltd.), the product name “SN-100P” (Ishihara Sangyo Co., Ltd.) Product name “SN-100D (water-dispersed product)” (manufactured by Ishihara Sangyo Co., Ltd.), for example, titanium oxide, product name “TTO series” (manufactured by Ishihara Sangyo Co., Ltd.), etc., for example, zinc oxide Trade name “SnO-310” (manufactured by Sumitomo Osaka Cement), trade name “SnO-350” (manufactured by Sumitomo Osaka Cement), trade name “SnO-410” (manufactured by Sumitomo Osaka Cement), and the like.
　これらの熱伝導性粒子のうち、好ましくは、水和金属化合物が挙げられ、より好ましくは、粘着剤層に高い熱伝導性と難燃性とを付与するという理由から、水酸化アルミニウムが挙げられる。また、金属窒化物、金属酸化物も好ましく挙げられ、より好ましくは、窒化ホウ素、酸化アルミニウム、酸化マグネシウムが挙げられる。 Of these thermally conductive particles, preferably, a hydrated metal compound is used, and more preferably, aluminum hydroxide is used because it imparts high thermal conductivity and flame retardancy to the pressure-sensitive adhesive layer. . In addition, metal nitrides and metal oxides are also preferable, and boron nitride, aluminum oxide, and magnesium oxide are more preferable.
　なお、熱伝導性粒子の形状は特に限定されず、バルク状、針形状、板形状、鱗片状（層状を含む）であってもよい。バルク形状には、例えば、球形状、直方体形状、破砕状、丸味状、凝集体またはそれらの異形形状が含まれる。 The shape of the thermally conductive particles is not particularly limited, and may be a bulk shape, a needle shape, a plate shape, or a scale shape (including a layer shape). The bulk shape includes, for example, a spherical shape, a rectangular parallelepiped shape, a crushed shape, a round shape, an aggregate, or a deformed shape thereof.
　熱伝導性粒子は、平均粒子径が異なる３種以上の熱伝導性粒子を含有している。具体的には、平均粒子径が異なる３種類以上の熱伝導性粒子を混合したときの空間率が、７２％以下であり、好ましくは、７０％以下であり、さらに好ましくは、６５％以下であり、また、例えば、３０％以上、好ましくは、５０％以上、さらに好ましくは、５５％以上である。 The heat conductive particles contain three or more kinds of heat conductive particles having different average particle diameters. Specifically, the space ratio when mixing three or more kinds of thermally conductive particles having different average particle diameters is 72% or less, preferably 70% or less, and more preferably 65% or less. And, for example, 30% or more, preferably 50% or more, and more preferably 55% or more.
　空間率が上記範囲内であると、高い熱伝導率を粘着剤層に付与することができる。 When the space ratio is within the above range, high thermal conductivity can be imparted to the pressure-sensitive adhesive layer.
　空間率は、「空間率（％）＝１００－｛（タップ密度）／（熱伝導性粒子の真密度）｝×１００」により、算出される。なお、タップ密度は、紛体特性評価装置（パウダーテスタ「ＰＴ－Ｒ」、ホソカワミクロン社製）を用いて、測定される。 The space ratio is calculated by “space ratio (%) = 100 − {(tap density) / (true density of thermally conductive particles)} × 100”. The tap density is measured using a powder characteristic evaluation device (powder tester “PT-R”, manufactured by Hosokawa Micron Corporation).
　熱伝導性粒子の真密度は、例えば、０．８ｇ／ｃｍ３以上、好ましくは、１．５ｇ／ｃｍ３以上であり、また、例えば、２０ｇ／ｃｍ３以下、好ましくは、１０ｇ／ｃｍ３以下でもある。 The true density of the thermally conductive particles is, for example, 0.8 g / cm 3 or more, preferably 1.5 g / cm 3 or more, and for example, 20 g / cm 3 or less, preferably 10 g / cm 3 or less. But there is.
　熱伝導性粒子の真密度は、乾式密度計（ガス置換法）によって求められる。 The true density of the thermally conductive particles is determined by a dry densimeter (gas displacement method).
　好ましくは、熱伝導性粒子が、平均粒子径３μｍ未満の第１熱伝導性粒子と、平均粒子径３μｍ以上７０μｍ未満の第２熱伝導性粒子と、少なくともさらに平均粒子径が異なる１種の熱伝導性粒子を含有している。 Preferably, the heat conductive particles are a first heat conductive particle having an average particle diameter of less than 3 μm, a second heat conductive particle having an average particle diameter of 3 μm or more and less than 70 μm, and at least one kind of heat having a different average particle diameter. Contains conductive particles.
　より好ましくは、熱伝導性粒子が、第１熱伝導性粒子と、第２熱伝導性粒子と、平均粒子径７０μｍ以上の第３熱伝導性粒子とを含有している。または、熱伝導性粒子が、第１熱伝導性粒子と、第２熱伝導性粒子と、平均粒子径３μｍ以上７０μｍ未満で鱗片状である第４熱伝導性粒子とを含有している。このような３種類以上の熱伝導性粒子を含有すると、より一層高い熱伝導率を粘着剤層に付与することができる。 More preferably, the thermally conductive particles contain first thermally conductive particles, second thermally conductive particles, and third thermally conductive particles having an average particle diameter of 70 μm or more. Alternatively, the heat conductive particles contain first heat conductive particles, second heat conductive particles, and fourth heat conductive particles having an average particle diameter of 3 μm or more and less than 70 μm and having a scaly shape. When such three or more kinds of thermally conductive particles are contained, a higher thermal conductivity can be imparted to the pressure-sensitive adhesive layer.
　第１熱伝導性粒子の平均粒子径は、３μｍ未満、好ましくは、２μｍ以下であり、また、例えば、０．５μｍ以上である。第１熱伝導性粒子の形状は、上記した形状が挙げられ、好ましくは、バルク状が挙げられる。 The average particle diameter of the first heat conductive particles is less than 3 μm, preferably 2 μm or less, and for example, 0.5 μm or more. Examples of the shape of the first thermally conductive particles include the shapes described above, and preferably a bulk shape.
　第２熱伝導性粒子の平均粒子径は、３μｍ以上、好ましくは、２０μｍ以上であり、また、例えば、７０μｍ未満、好ましくは、６０μｍ未満である。第２熱伝導性粒子の形状は、上記した形状が挙げられ、好ましくは、バルク状が挙げられる。 The average particle diameter of the second heat conductive particles is 3 μm or more, preferably 20 μm or more, and is, for example, less than 70 μm, preferably less than 60 μm. The shape of the second thermally conductive particles includes the above-described shape, and preferably a bulk shape.
　第３熱伝導性粒子の平均粒子径は、７０μｍ以上、好ましくは、９０μｍ以上であり、また、例えば、３００μｍ未満、好ましくは、１５０μｍ未満である。第３熱伝導性粒子の形状は、上記した形状が挙げられ、好ましくは、バルク状が挙げられる。 The average particle size of the third heat conductive particles is 70 μm or more, preferably 90 μm or more, and is, for example, less than 300 μm, preferably less than 150 μm. The shape of the third thermally conductive particles includes the above-described shape, and preferably a bulk shape.
　第４熱伝導性粒子は、鱗片状に形成され、その平均粒子径は、３μｍ以上、好ましくは、２０μｍ以上であり、また、例えば、７０μｍ未満、好ましくは、５０μｍ未満である。 The fourth heat conductive particles are formed in a scale shape, and the average particle diameter thereof is 3 μm or more, preferably 20 μm or more, and for example, less than 70 μm, preferably less than 50 μm.
　熱伝導性粒子の平均粒子径は、レーザー散乱法における粒度分布測定法によって求められる（具体的には、レーザー散乱式粒度分布計により計測する）粒度分布に基づいて、Ｄ５０値（累積５０％メジアン径）として求められる。 The average particle size of the thermally conductive particles is determined by a particle size distribution measurement method in the laser scattering method (specifically, measured by a laser scattering particle size distribution meter), based on a D50 value (cumulative 50% median). (Diameter).
　また、３種以上の熱伝導性粒子において、好ましくは、そのうち少なくとも１種の熱伝導性粒子が、金属酸化物または金属窒化物から形成され、それ以外の熱伝導性粒子が、金属水酸化物から形成されている。 Further, in the three or more types of thermally conductive particles, preferably, at least one of the thermally conductive particles is formed of a metal oxide or a metal nitride, and the other thermally conductive particles are a metal hydroxide. Formed from.
　具体的には、第１熱伝導性粒子は、好ましくは、金属水酸化物、より好ましくは、水酸化アルミニウムから形成されている。第２熱伝導性粒子は、好ましくは、金属水酸化物、金属酸化物または金属窒化物、より好ましくは、水酸化アルミニウムまたは酸化マグネシウムから形成されている。また、第３熱伝導性粒子は、好ましくは、金属酸化物または金属窒化物、より好ましくは、金属酸化物、さらに好ましくは、酸化アルミニウムから形成されている。また、第４熱伝導性粒子は、金属酸化物または金属窒化物、より好ましくは、金属窒化物、さらに好ましくは、窒化ホウ素から形成されている。 Specifically, the first thermally conductive particles are preferably formed from a metal hydroxide, more preferably aluminum hydroxide. The second thermally conductive particles are preferably formed from metal hydroxide, metal oxide or metal nitride, more preferably from aluminum hydroxide or magnesium oxide. The third thermally conductive particles are preferably formed from metal oxide or metal nitride, more preferably metal oxide, and still more preferably aluminum oxide. The fourth thermally conductive particles are made of metal oxide or metal nitride, more preferably metal nitride, and still more preferably boron nitride.
　この場合、金属水酸化物から形成される熱伝導性粒子は、粘着剤原料に対して、例えば、３０体積％以上、好ましくは、４０体積％以上であり、また、例えば、７０体積％以下、好ましくは、６０体積％以下の割合で配合される。また、金属酸化物または金属窒化物（より好ましくは、酸化アルミニウム、酸化マグネシウムまたは窒化ホウ素）から形成される熱伝導性粒子の含有割合は、粘着剤原料に対して、例えば、５体積％以上、好ましくは、８体積％以上であり、また、例えば、２５体積％以下、好ましくは、２０体積％以下の配合割合で配合される。 In this case, the heat conductive particles formed from the metal hydroxide are, for example, 30% by volume or more, preferably 40% by volume or more, and, for example, 70% by volume or less with respect to the pressure-sensitive adhesive raw material. Preferably, it mix | blends in the ratio of 60 volume% or less. Further, the content ratio of the heat conductive particles formed from metal oxide or metal nitride (more preferably, aluminum oxide, magnesium oxide or boron nitride) is, for example, 5% by volume or more with respect to the pressure-sensitive adhesive raw material. Preferably, it is 8 volume% or more, for example, is mix | blended by the mixture ratio of 25 volume% or less, Preferably, 20 volume% or less.
　また、熱伝導性粒子は、３種以上の平均粒子径の熱伝導性粒子を含有していればよく、例えば、４種類の平均粒子径の熱伝導性粒子を含有することもできる。 Further, the heat conductive particles only need to contain three or more kinds of heat conductive particles having an average particle diameter, and for example, may contain four kinds of heat conductive particles having an average particle diameter.
　熱伝導性粒子が、４種類の平均粒子径の熱伝導性粒子を含有する場合、例えば、第１熱伝導性粒子が、第２熱伝導性粒子、第３熱伝導性粒子、および、第４熱伝導性粒子のいずれにおいても、さらに２種類以上の平均粒子径を備えることができる。具体的には、平均粒子径３μｍ以上７０μｍ未満の第２熱伝導性粒子が、さらに、例えば、平均粒子径３μｍ以上４０μｍ未満の第２熱伝導性粒子および平均粒子径４０μｍ以上７０μｍ未満の第２熱伝導性粒子を備えることができる。 When the heat conductive particles contain four kinds of heat conductive particles having an average particle diameter, for example, the first heat conductive particles include the second heat conductive particles, the third heat conductive particles, and the fourth heat conductive particles. In any of the thermally conductive particles, two or more kinds of average particle diameters can be further provided. Specifically, the second heat conductive particles having an average particle diameter of 3 μm or more and less than 70 μm are further, for example, the second heat conductive particles having an average particle diameter of 3 μm or more and less than 40 μm and the second heat conductive particles having an average particle diameter of 40 μm or more and less than 70 μm. Thermally conductive particles can be provided.
　また、第１熱伝導性粒子が、第２熱伝導性粒子、第３熱伝導性粒子、および、第４熱伝導性粒子は、２種類以上の異なる材料からなる熱伝導性粒子を備えることができる。具体的には、例えば、第２熱伝導性粒子は、２種類の異なる材料からなる熱伝導性粒子を備える。すなわち、熱伝導性粒子は、好ましくは、第１熱伝導性粒子と、異なる材料から形成される２種の第２熱伝導性粒子とを備えている。このような２種類の異なる材料としては、好ましくは、金属水酸化物と金属酸化物との組み合わせが挙げられ、より好ましくは、水酸化マグネシウムと酸化マグネシウムとの組み合わせが挙げられる。 The first heat conductive particles may include the second heat conductive particles, the third heat conductive particles, and the fourth heat conductive particles, which include heat conductive particles made of two or more different materials. it can. Specifically, for example, the second thermally conductive particles include thermally conductive particles made of two different materials. That is, the heat conductive particles preferably include first heat conductive particles and two types of second heat conductive particles formed of different materials. Such two different materials preferably include a combination of a metal hydroxide and a metal oxide, more preferably a combination of magnesium hydroxide and magnesium oxide.
　熱伝導性粒子全量中における第１熱伝導性粒子の配合割合は、例えば、１０質量％以上、好ましくは、２０質量％以上、より好ましくは、３０質量％以上であり、また、例えば、７０質量％以下、好ましくは、５５質量％以下、より好ましくは、４５質量％以下でもある。 The blending ratio of the first heat conductive particles in the total amount of the heat conductive particles is, for example, 10% by mass or more, preferably 20% by mass or more, more preferably 30% by mass or more, and for example, 70% by mass. % Or less, preferably 55% by mass or less, more preferably 45% by mass or less.
　熱伝導性粒子全量中における第２熱伝導性粒子の配合割合は、例えば、１５質量％以上、好ましくは、２５質量％以上、より好ましくは、３５質量％以上であり、また、例えば、７０質量％以下、好ましくは、６０質量％以下、より好ましくは、５０質量％以下でもある。なお、第２熱伝導性粒子が異なる２種の材料を備えたり、異なる２種の平均粒子径を備える場合は、その配合割合の合計は、熱伝導性粒子全量中に対して、例えば、３０質量％以上、好ましくは、４０質量％以上、より好ましくは、５０質量％以上であり、また、例えば、８０質量％以下、好ましくは、７５質量％以下、より好ましくは、７０質量％以下でもある。 The blending ratio of the second thermally conductive particles in the total amount of thermally conductive particles is, for example, 15% by mass or more, preferably 25% by mass or more, more preferably 35% by mass or more, and for example, 70% by mass. % Or less, preferably 60% by mass or less, more preferably 50% by mass or less. In addition, when the 2nd heat conductive particle is provided with 2 types of different materials, or when it is provided with 2 types of different average particle diameters, the sum total of the mixture ratio is 30 for example with respect to the total amount of heat conductive particles. % By mass or more, preferably 40% by mass or more, more preferably 50% by mass or more, and for example, 80% by mass or less, preferably 75% by mass or less, more preferably 70% by mass or less. .
　熱伝導性粒子が第３熱伝導性粒子を含む場合、熱伝導性粒子全量中における第３熱伝導性粒子の配合割合は、例えば、５質量％以上、好ましくは、１０質量％以上、より好ましくは、１５質量％以上であり、また、例えば、５０質量％以下、好ましくは、４０質量％以下、より好ましくは、３０質量％以下でもある。 When the heat conductive particles include the third heat conductive particles, the blending ratio of the third heat conductive particles in the total amount of the heat conductive particles is, for example, 5% by mass or more, preferably 10% by mass or more, and more preferably. Is 15% by mass or more, and is, for example, 50% by mass or less, preferably 40% by mass or less, and more preferably 30% by mass or less.
　熱伝導性粒子が第４熱伝導性粒子を含む場合、熱伝導性粒子全量中における第４熱伝導性粒子の配合割合は、例えば、１質量％以上、好ましくは、５質量％以上、より好ましくは、１０質量％以上であり、また、例えば、４０質量％以下、好ましくは、３０質量％以下、より好ましくは、２０質量％以下でもある。 When the heat conductive particles include the fourth heat conductive particles, the blending ratio of the fourth heat conductive particles in the total amount of the heat conductive particles is, for example, 1% by mass or more, preferably 5% by mass or more, and more preferably. Is 10% by mass or more, and for example, 40% by mass or less, preferably 30% by mass or less, more preferably 20% by mass or less.
　これらの熱伝導性粒子全量は、粘着剤原料中に、例えば、７５質量％以上、好ましくは、８０質量％以上であり、例えば、９０質量％以下、好ましくは、８７質量％以下の割合で配合される。また、熱伝導性粒子全量は、粘着剤原料中に、５５体積％以上、好ましくは、６０体積％以上であり、７５体積％以下、好ましくは、７０体積％以下の割合で配合される。 The total amount of these heat conductive particles is, for example, 75% by mass or more, preferably 80% by mass or more, for example, 90% by mass or less, preferably 87% by mass or less in the pressure-sensitive adhesive raw material. Is done. The total amount of the heat conductive particles is 55% by volume or more, preferably 60% by volume or more, and 75% by volume or less, preferably 70% by volume or less in the pressure-sensitive adhesive raw material.
　熱伝導性粒子の配合割合が上記範囲内であると、高い熱伝導率、良好な硬度および難燃性を粘着剤層に付与することができる。 When the blending ratio of the heat conductive particles is within the above range, high thermal conductivity, good hardness and flame retardancy can be imparted to the pressure-sensitive adhesive layer.
　次いで、粘着剤原料の調製方法について説明する。 Next, a method for preparing the pressure-sensitive adhesive raw material will be described.
　粘着剤原料を調製するには、まず、上記したモノマー成分と、重合開始剤とを含有するモノマー組成物を調製する。 To prepare the pressure-sensitive adhesive raw material, first, a monomer composition containing the above-described monomer component and a polymerization initiator is prepared.
　モノマー組成物を調製するには、上記したモノマー成分に重合開始剤を配合する。 In order to prepare a monomer composition, a polymerization initiator is blended with the above monomer components.
　重合開始剤としては、例えば、光重合開始剤、熱重合開始剤などが挙げられる。 Examples of the polymerization initiator include a photopolymerization initiator and a thermal polymerization initiator.
　光重合開始剤としては、例えば、ベンゾインエーテル系光重合開始剤、アセトフェノン系光重合開始剤、α－ケトール系光重合開始剤、芳香族スルホニルクロリド系光重合開始剤、光活性オキシム系光重合開始剤、ベンゾイン系光重合開始剤、ベンジル系光重合開始剤、ベンゾフェノン系光重合開始剤、チオキサントン系光重合開始剤などが挙げられる。 Examples of the photopolymerization initiator include a benzoin ether photopolymerization initiator, an acetophenone photopolymerization initiator, an α-ketol photopolymerization initiator, an aromatic sulfonyl chloride photopolymerization initiator, and a photoactive oxime photopolymerization initiator. Agents, benzoin photopolymerization initiators, benzyl photopolymerization initiators, benzophenone photopolymerization initiators, thioxanthone photopolymerization initiators, and the like.
　ベンゾインエーテル系光重合開始剤としては、例えば、ベンゾインメチルエーテル、ベンゾインエチルエーテル、ベンゾインプロピルエーテル、ベンゾインイソプロピルエーテル、ベンゾインイソブチルエーテル、２，２－ジメトキシ－１，２－ジフェニルエタン－１－オン、アニソールメチルエーテルなどが挙げられる。 Examples of the benzoin ether photopolymerization initiator include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, and anisole. Examples include methyl ether.
　アセトフェノン系光重合開始剤としては、例えば、２，２－ジエトキシアセトフェノン、２，２－ジメトキシ－２－フェニルアセトフェノン、４－フェノキシジクロロアセトフェノン、４－（ｔ－ブチル）ジクロロアセトフェノンなどが挙げられる。 Examples of the acetophenone photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 4-phenoxydichloroacetophenone, 4- (t-butyl) dichloroacetophenone, and the like.
　α－ケトール系光重合開始剤としては、例えば、２－メチル－２－ヒドロキシプロピオフェノン、１－［４－（２－ヒドロキシエチル）フェニル］－２－メチルプロパン－１－オン、１－ヒドロキシシクロヘキシルフェニルケトンなどが挙げられる。 Examples of α-ketol photopolymerization initiators include 2-methyl-2-hydroxypropiophenone, 1- [4- (2-hydroxyethyl) phenyl] -2-methylpropan-1-one, and 1-hydroxy. Examples include cyclohexyl phenyl ketone.
　芳香族スルホニルクロリド系光重合開始剤としては、例えば、２－ナフタレンスルホニルクロライドなどが挙げられる。 Examples of the aromatic sulfonyl chloride photopolymerization initiator include 2-naphthalene sulfonyl chloride.
　光活性オキシム系光重合開始剤としては、例えば、１－フェニル－１，１－プロパンジオン－２－（ｏ－エトキシカルボニル）－オキシムなどが挙げられる。 Examples of the photoactive oxime photopolymerization initiator include 1-phenyl-1,1-propanedione-2- (o-ethoxycarbonyl) -oxime.
　ベンゾイン系光重合開始剤としては、例えば、ベンゾインなどが挙げられる。 Examples of the benzoin photopolymerization initiator include benzoin.
　ベンジル系光重合開始剤としては、例えば、ベンジルなどが挙げられる。 Examples of the benzyl photopolymerization initiator include benzyl.
　ベンゾフェノン系光重合開始剤としては、例えば、ベンゾフェノン、ベンゾイル安息香酸、３、３′－ジメチル－４－メトキシベンゾフェノン、ポリビニルベンゾフェノンなどが挙げられる。 Examples of the benzophenone photopolymerization initiator include benzophenone, benzoylbenzoic acid, 3,3′-dimethyl-4-methoxybenzophenone, and polyvinylbenzophenone.
　チオキサントン系光重合開始剤としては、例えば、チオキサントン、２－クロロチオキサントン、２－メチルチオキサントン、２，４－ジメチルチオキサントン、イソプロピルチオキサントン、２，４－ジイソプロピルチオキサントン、デシルチオキサントンなどが挙げられる。 Examples of the thioxanthone photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, decylthioxanthone, and the like.
　熱重合開始剤としては、例えば、２，２′－アゾビスイソブチロニトリル、２，２′－アゾビス－２－メチルブチロニトリル、２，２′－アゾビス（２－メチルプロピオン酸）ジメチル、４，４′－アゾビス－４－シアノバレリアン酸、アゾビスイソバレロニトリル、２，２′－アゾビス（２－アミジノプロパン）ジヒドロクロライド、２，２′－アゾビス［２－（５－メチル－２－イミダゾリン－２－イル）プロパン］ジヒドロクロライド、２，２′－アゾビス（２－メチルプロピオンアミジン）二硫酸塩、２，２′－アゾビス（Ｎ，Ｎ′－ジメチレンイソブチルアミジン）ヒドロクロライド、２，２’－アゾビス［Ｎ－（２－カルボキシエチル）－２－メチルプロピオンアミジン］ハイドレートなどのアゾ系重合開始剤、例えば、ジベンゾイルペルオキシド、ｔ－ブチルペルマレエート、ｔ－ブチルハイドロパーオキサイド、過酸化水素などの過酸化物系重合開始剤、例えば、過硫酸カリウム、過硫酸アンモニウムなどの過硫酸塩、例えば、過硫酸塩と亜硫酸水素ナトリウムとの組み合わせ、過酸化物とアスコルビン酸ナトリウムとの組み合わせなどのレドックス系重合開始剤などが挙げられる。 Examples of the thermal polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis-2-methylbutyronitrile, 2,2′-azobis (2-methylpropionic acid) dimethyl, 4,4'-azobis-4-cyanovaleric acid, azobisisovaleronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis [2- (5-methyl-2- Imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (N, N'-dimethyleneisobutylamidine) hydrochloride, 2, Azo polymerization initiators such as 2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate, Peroxide polymerization initiators such as zoyl peroxide, t-butyl permaleate, t-butyl hydroperoxide, hydrogen peroxide, and persulfates such as potassium persulfate and ammonium persulfate, such as persulfate Examples include redox polymerization initiators such as a combination with sodium bisulfite and a combination of peroxide and sodium ascorbate.
　これらの重合開始剤は、単独（１種類のみ）で使用することもでき、また、２種以上組み合わせて使用することもできる。 These polymerization initiators can be used alone (only one kind) or in combination of two or more kinds.
　これらの重合開始剤のうち、重合時間を短くすることができる利点などから、好ましくは、光重合開始剤が挙げられる。 Among these polymerization initiators, a photopolymerization initiator is preferable because of the advantage that the polymerization time can be shortened.
　重合開始剤として光重合開始剤を配合する場合には、光重合開始剤は、特に限定されないが、例えば、モノマー成分１００質量部に対して、例えば、０．０１質量部以上、好ましくは、０．０５質量部以上であり、また、例えば、５質量部以下、好ましくは、３質量部以下の割合で配合される。 When a photopolymerization initiator is blended as a polymerization initiator, the photopolymerization initiator is not particularly limited, but is, for example, 0.01 parts by mass or more, preferably 0 with respect to 100 parts by mass of the monomer component. 0.05 parts by mass or more, and for example, 5 parts by mass or less, preferably 3 parts by mass or less.
　また、重合開始剤として熱重合開始剤を配合する場合には、熱重合開始剤は、特に限定されず、利用可能な割合で配合される。 In addition, when a thermal polymerization initiator is blended as a polymerization initiator, the thermal polymerization initiator is not particularly limited and is blended in an available ratio.
　モノマー組成物では、必要により、モノマー成分の一部を重合させることもできる。 In the monomer composition, a part of the monomer component can be polymerized if necessary.
　モノマー成分の一部を重合させるには、光重合開始剤を配合している場合には、モノマー成分と光重合開始剤との混合物に紫外線を照射する。紫外線を照射するには、光重合開始剤が励起されるような照射エネルギーで、モノマー組成物の粘度（ＢＨ粘度計、Ｎｏ．５ロータ、１０ｒｐｍ、測定温度３０℃）が、例えば、５Ｐａ・ｓ以上（好ましくは、１０Ｐａ・ｓ以上）、例えば、３０Ｐａ・ｓ以下（好ましくは、２０Ｐａ・ｓ以下）になるまで、照射する。 In order to polymerize a part of the monomer component, when a photopolymerization initiator is blended, the mixture of the monomer component and the photopolymerization initiator is irradiated with ultraviolet rays. In order to irradiate ultraviolet rays, the monomer composition has a viscosity (BH viscometer, No. 5 rotor, 10 rpm, measurement temperature 30 ° C.) with irradiation energy that excites the photopolymerization initiator, for example, 5 Pa · s. Irradiation is carried out until it is above (preferably 10 Pa · s or more), for example, 30 Pa · s or less (preferably 20 Pa · s or less).
　また、熱重合開始剤を配合している場合には、モノマー成分と熱重合開始剤との混合物を、例えば、熱重合開始剤の分解温度以上、具体的には、２０～１００℃程度の重合温度で、光重合開始剤を配合している場合と同様に、モノマー組成物の粘度（ＢＨ粘度計、Ｎｏ．５ロータ、１０ｒｐｍ、測定温度３０℃）が、例えば、５Ｐａ・ｓ以上（好ましくは、１０Ｐａ・ｓ以上）、例えば、３０Ｐａ・ｓ以下（好ましくは、２０Ｐａ・ｓ以下）になるまで加熱する。 In addition, when a thermal polymerization initiator is blended, the mixture of the monomer component and the thermal polymerization initiator is polymerized at, for example, a temperature higher than the decomposition temperature of the thermal polymerization initiator, specifically about 20 to 100 ° C. Similarly to the case where the photopolymerization initiator is blended at the temperature, the viscosity of the monomer composition (BH viscometer, No. 5 rotor, 10 rpm, measurement temperature 30 ° C.) is, for example, 5 Pa · s or more (preferably 10 Pa · s or higher), for example, 30 Pa · s or lower (preferably 20 Pa · s or lower).
　なお、モノマー成分の一部を重合させてモノマー組成物を調製する場合には、（メタ）アクリル酸アルキルエステルモノマーと、極性基含有モノマーおよび共重合可能モノマーから選択されるモノマーと、重合開始剤とを配合して、上記したように、モノマーの一部を重合させ、その後、架橋剤を配合することもできる。 When preparing a monomer composition by polymerizing a part of the monomer component, a (meth) acrylic acid alkyl ester monomer, a monomer selected from a polar group-containing monomer and a copolymerizable monomer, and a polymerization initiator As described above, a part of the monomer can be polymerized, and then a crosslinking agent can be blended.
　架橋剤は、エチレン系不飽和炭化水素基を複数有する多官能化合物であって、例えば、ヘキサンジオールジ（メタ）アクリレート、（ポリ）エチレングリコールジ（メタ）アクリレート、（ポリ）プロピレングリコールジ（メタ）アクリレート、ネオペンチルグリコールジ（メタ）アクリレート、ペンタエリスリトールジ（メタ）アクリレート、ペンタエリスリトールトリ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、テトラメチロールプロパントリ（メタ）アクリレート、アリル（メタ）アクリレート、ビニル（メタ）アクリレート、エポキシ（メタ）アクリレート、ポリエステル（メタ）アクリレート、ウレタン（メタ）アクリレートなどの２官能以上の多官能オリゴマーが挙げられる。 The crosslinking agent is a polyfunctional compound having a plurality of ethylenically unsaturated hydrocarbon groups. For example, hexanediol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meta) ) Acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolpropane tri Bifunctional such as (meth) acrylate, allyl (meth) acrylate, vinyl (meth) acrylate, epoxy (meth) acrylate, polyester (meth) acrylate, urethane (meth) acrylate, etc. Polyfunctional oligomer of above mentioned.
　架橋剤は、単独使用または２種以上併用することができる。 The crosslinking agent can be used alone or in combination of two or more.
　架橋剤として、好ましくは、ジペンタエリスリトールヘキサ（メタ）アクリレートが挙げられる。 As the cross-linking agent, dipentaerythritol hexa (meth) acrylate is preferable.
　架橋剤の含有割合は、モノマー成分１００質量部に対して、例えば、０．００１質量部以上、好ましくは、０．０１質量部以上であり、また、例えば、１０質量部以下、好ましくは、１質量部以下でもある。 The content of the crosslinking agent is, for example, 0.001 part by mass or more, preferably 0.01 part by mass or more, for example, 10 parts by mass or less, preferably 1 part by mass with respect to 100 parts by mass of the monomer component. It is also below mass parts.
　次いで、粘着剤原料を調製するには、得られたモノマー組成物に、上記した熱伝導性粒子を配合し、混合する。 Next, in order to prepare the pressure-sensitive adhesive material, the above-described monomer composition is blended with the above-described thermally conductive particles.
　なお、熱伝導性粒子などは、有機溶剤などの溶媒中に分散又は溶解した状態で、モノマー組成物に配合することができる。 In addition, heat conductive particles etc. can be mix | blended with a monomer composition in the state disperse | distributed or melt | dissolved in solvents, such as an organic solvent.
　これにより、粘着剤原料が調製される。 Thereby, the pressure-sensitive adhesive raw material is prepared.
　また、粘着剤原料は、熱伝導性粒子が配合されたモノマー組成物において、モノマー成分をすべて重合させることにより熱伝導性粒子を含有するポリマー成分を形成し、その後、そのポリマー成分を有機溶媒などの溶媒に溶解させることにより、ポリマー組成物として調製することもできる。 In addition, the pressure-sensitive adhesive raw material forms a polymer component containing the thermally conductive particles by polymerizing all the monomer components in the monomer composition in which the thermally conductive particles are blended. It can also be prepared as a polymer composition by dissolving in a solvent.
　なお、モノマー組成物やポリマー組成物には、必要により、分散剤、粘着付与剤、アクリル系オリゴマー、シランカップリング剤、フッ素系界面活性剤、可塑剤、充填材、老化防止剤、着色剤などの添加剤を配合することもできる。 For monomer compositions and polymer compositions, dispersants, tackifiers, acrylic oligomers, silane coupling agents, fluorosurfactants, plasticizers, fillers, anti-aging agents, colorants, etc., are necessary. These additives can also be blended.
　熱伝導性粒子を凝集させることなく安定して分散させる観点から、モノマー組成物やポリマー組成物中に、好ましくは、分散剤を配合する。分散剤としては、例えば、リン酸エステル系分散剤が挙げられ、具体的には、ポリオキシエチレンアルキル（またはアルキルアリル）エーテルまたはポリオキシエチレンアルキルアリールエーテルのリン酸モノエステル、ポリオキシエチレンアルキルエーテルまたはポリオキシエチレンアルキルアリールエーテルのリン酸ジエステル、リン酸トリエステル、これらの誘導体などが挙げられる。 From the viewpoint of stably dispersing the heat conductive particles without agglomerating, a dispersant is preferably blended in the monomer composition or the polymer composition. Examples of the dispersant include phosphate ester-based dispersants. Specifically, polyoxyethylene alkyl (or alkylallyl) ether or polyoxyethylene alkylaryl ether phosphate monoester, polyoxyethylene alkyl ether Alternatively, polyoxyethylene alkylaryl ether phosphoric acid diesters, phosphoric acid triesters, derivatives thereof, and the like can be given.
　具体的には、第一工業製薬社製の「プライサーフシリーズ」Ａ２１２Ｅ、Ａ２０８Ｆ、Ａ２１０Ｇ、Ａ２１２Ｃ，Ａ２１５Ｃ、東邦化学社製の「フォスファノール」ＲＥ６１０，ＲＳ７１０，ＲＳ６１０などが挙げられる。 Specifically, “Plisurf Series” A212E, A208F, A210G, A212C, A215C manufactured by Daiichi Kogyo Seiyaku Co., Ltd., “Phosphanol” RE610, RS710, RS610 manufactured by Toho Chemical Co., Ltd. and the like can be mentioned.
　これらのリン酸エステル系分散剤は、単独または２種以上混合して使用することができる。 These phosphate ester dispersants can be used alone or in combination of two or more.
　粘着剤原料中における分散剤の配合割合は、例えば、０．０１質量％以上、好ましくは、０．１質量％以上であり、また、例えば、１０質量％以下、好ましくは、５質量％以下でもある。 The blending ratio of the dispersant in the pressure-sensitive adhesive raw material is, for example, 0.01% by mass or more, preferably 0.1% by mass or more, and for example, 10% by mass or less, preferably 5% by mass or less. is there.
　得られた粘着剤原料の粘度（ＢＭ粘度計、Ｎｏ．４ロータ、１２ｒｐｍ、測定温度２３℃）は、例えば、５０Ｐａ・ｓ以下、好ましくは、４０Ｐａ・ｓ以下、より好ましくは、３５Ｐａ・ｓ以下であり、また、例えば、５Ｐａ・ｓ以上、より好ましくは、１０Ｐａ・ｓ以上でもある。 The viscosity of the obtained pressure-sensitive adhesive material (BM viscometer, No. 4 rotor, 12 rpm, measurement temperature 23 ° C.) is, for example, 50 Pa · s or less, preferably 40 Pa · s or less, more preferably 35 Pa · s or less. Also, for example, 5 Pa · s or more, more preferably 10 Pa · s or more.
　なお、粘着剤原料には、気泡を含有させることもできる。気泡を含有した粘着剤原料を用いて、熱伝導性粘着シートを作製することにより、熱伝導性粘着シートを発泡体とすることができる。 It should be noted that the pressure-sensitive adhesive material may contain bubbles. A heat conductive adhesive sheet can be made into a foam by producing a heat conductive adhesive sheet using the adhesive raw material containing air bubbles.
　粘着剤原料に気泡を含有させるには、例えば、中央部に貫通孔を持った円盤上に多数の歯を有するステータ（固定歯）と、ステータに対向し、円盤上に多数の歯を有するロータ（回転歯）とを備えた撹拌装置を用いて、ステータの歯とロータの歯との間に粘着剤原料を導入し、ロータを高速回転させながら、ステータの貫通孔を通して気泡を形成させるための気体を、粘着剤原料中に導入する。 In order to contain air bubbles in the adhesive raw material, for example, a stator (fixed tooth) having a large number of teeth on a disk having a through hole in the center, and a rotor having a large number of teeth on the disk facing the stator In order to form bubbles through the through-holes of the stator while introducing the adhesive raw material between the teeth of the stator and the teeth of the rotor using a stirrer equipped with (rotating teeth) A gas is introduced into the adhesive raw material.
　粘着剤原料に導入される気体としては、特に限定されず、例えば、窒素、二酸化炭素、アルゴンなどの不活性ガス、例えば、空気などが挙げられる。 The gas introduced into the pressure-sensitive adhesive raw material is not particularly limited, and examples thereof include inert gases such as nitrogen, carbon dioxide, and argon, such as air.
　粘着剤原料に導入される気体としては、粘着剤原料の反応を阻害しにくいことから、好ましくは、不活性ガス、より好ましくは、窒素が挙げられる。 The gas introduced into the pressure-sensitive adhesive material is preferably an inert gas, more preferably nitrogen, because it hardly inhibits the reaction of the pressure-sensitive adhesive material.
　気泡は、例えば、粘着剤原料の全体積に対して、例えば、５体積％以上、好ましくは、１０体積％以上、より好ましくは、１２体積％以上であり、また、例えば、５０体積％以下、好ましくは、４０体積％以下、より好ましくは、３５体積％以下の割合で導入される。 The bubbles are, for example, 5% by volume or more, preferably 10% by volume or more, more preferably 12% by volume or more, for example, 50% by volume or less, based on the total volume of the pressure-sensitive adhesive material. Preferably, it is introduced at a ratio of 40% by volume or less, more preferably 35% by volume or less.
　図１は、熱伝導性粘着シートの作製方法を説明する説明図である。 FIG. 1 is an explanatory view for explaining a method for producing a heat conductive pressure-sensitive adhesive sheet.
　次いで、熱伝導性粘着シートの作製方法について説明する。 Next, a method for producing a heat conductive adhesive sheet will be described.
　熱伝導性粘着シートを作製するには、まず、図１（ａ）に示すように、基材としてのベースフィルム１の剥離処理が施された面に粘着剤原料２を塗布する。 In order to produce a heat conductive pressure-sensitive adhesive sheet, first, as shown in FIG. 1 (a), a pressure-sensitive adhesive material 2 is applied to the surface of the base film 1 as a base material that has been subjected to a peeling treatment.
　ベースフィルム１としては、例えば、ポリエステルフィルム（ポリエチレンテレフタレートフィルムなど）、例えば、フッ素系ポリマー（例えば、ポリテトラフルオロエチレン、ポリクロロトリフルオロエチレン、ポリフッ化ビニル、ポリフッ化ビニリデン、テトラフルオロエチレン－ヘキサフルオロプロピレン共重合体、クロロフルオロエチレン－フッ化ビニリデン共重合体など）からなるフッ素系フィルム、例えば、オレフィン系樹脂（ポリエチレン、ポリプロピレンなど）からなるオレフィン系樹脂フィルム、例えば、ポリ塩化ビニルフィルム、ポリイミドフィルム、ポリアミドフィルム（ナイロンフィルム）、レーヨンフィルムなどのプラスチック系基材フィルム（合成樹脂フィルム）、例えば、上質紙、和紙、クラフト紙、グラシン紙、合成紙、トップコート紙などの紙類、例えば、これらを複層化した複合体などが挙げられる。 Examples of the base film 1 include a polyester film (polyethylene terephthalate film and the like), for example, a fluorine-based polymer (for example, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoro). Fluorine film made of propylene copolymer, chlorofluoroethylene-vinylidene fluoride copolymer, etc., for example, olefin resin film made of olefin resin (polyethylene, polypropylene, etc.), eg, polyvinyl chloride film, polyimide film , Polyamide base film (nylon film), plastic base film (synthetic resin film) such as rayon film, eg, fine paper, Japanese paper, kraft paper, glass Down paper, synthetic paper, paper such as top-coated paper, for example, and they were double layered composites and the like.
　なお、粘着剤原料２がモノマー組成物として調製され、光重合開始剤を含有している場合には、粘着剤原料２に対する紫外線の照射を妨げないように、紫外線を透過するベースフィルム１を使用する。 In addition, when the adhesive raw material 2 is prepared as a monomer composition and contains a photopolymerization initiator, a base film 1 that transmits ultraviolet rays is used so as not to interfere with irradiation of ultraviolet rays to the adhesive raw material 2. To do.
　粘着剤原料２をベースフィルム１に塗布する方法としては、例えば、ロールコート、キスロールコート、グラビアコート、リバースコート、ロールブラッシュ、スプレーコート、ディップロールコート、バーコート、ナイフコート、エアーナイフコート、カーテンコート、リップコート、ダイコーターなどによる押出しコート法などが挙げられる。 Examples of the method for applying the adhesive material 2 to the base film 1 include roll coating, kiss roll coating, gravure coating, reverse coating, roll brush, spray coating, dip roll coating, bar coating, knife coating, air knife coating, Examples include an extrusion coating method using a curtain coat, a lip coat, a die coater, and the like.
　粘着剤原料２の塗工厚みとしては、例えば、１０μｍ以上、好ましくは、５０μｍ以上、より好ましくは、１００μｍ以上であり、また、例えば、１００００μｍ以下、好ましくは、５０００μｍ以下、より好ましくは、３０００μｍ以下でもある。 The coating thickness of the pressure-sensitive adhesive raw material 2 is, for example, 10 μm or more, preferably 50 μm or more, more preferably 100 μm or more, and for example, 10,000 μm or less, preferably 5000 μm or less, more preferably 3000 μm or less. But there is.
　熱伝導性粘着シートを作製するには、次いで、図１（ｂ）に示すように、粘着剤原料２の塗膜の上にカバーフィルム３を配置する。カバーフィルム３を塗膜の上に配置するには、カバーフィルム３の剥離処理が施された面が塗膜に接触するように、配置する。 In order to produce a heat conductive pressure-sensitive adhesive sheet, a cover film 3 is then placed on the coating film of the pressure-sensitive adhesive raw material 2 as shown in FIG. In order to arrange | position the cover film 3 on a coating film, it arrange | positions so that the surface in which the peeling process of the cover film 3 was performed contacts a coating film.
　カバーフィルム３としては、例えば、上記したベースフィルム１と同様のフィルムが挙げられる。また、粘着剤原料２がモノマー組成物として調製され、光重合開始剤を含有している場合には、粘着剤原料２に対する紫外線の照射を妨げないように、紫外線を透過するカバーフィルム３を使用する。 Examples of the cover film 3 include the same film as the base film 1 described above. Further, when the pressure-sensitive adhesive raw material 2 is prepared as a monomer composition and contains a photopolymerization initiator, a cover film 3 that transmits ultraviolet rays is used so as not to interfere with irradiation of the pressure-sensitive adhesive raw material 2 with ultraviolet rays. To do.
　熱伝導性粘着シートを作製するには、次いで、粘着剤原料２がモノマー組成物として調製されている場合には、図１（ｃ）に示すように、粘着剤原料２を反応させて、アクリル系粘着剤層４を形成する。 In order to produce a heat conductive adhesive sheet, when the adhesive raw material 2 is prepared as a monomer composition, the adhesive raw material 2 is reacted as shown in FIG. The system pressure-sensitive adhesive layer 4 is formed.
　粘着剤原料２を反応させるには、上記したように、光重合開始剤を配合している場合には、粘着剤原料２に紫外線を照射し、熱重合開始剤を配合している場合には、粘着剤原料２を加熱する。 In order to react the adhesive raw material 2, as described above, when the photopolymerization initiator is blended, the adhesive raw material 2 is irradiated with ultraviolet rays and the thermal polymerization initiator is blended. The adhesive raw material 2 is heated.
　また、粘着剤原料２がポリマー組成物から調製されている場合には、粘着剤原料２の塗工後、乾燥させて、溶媒を除去することにより、アクリル系粘着剤層４を形成する。 If the pressure-sensitive adhesive material 2 is prepared from a polymer composition, the acrylic pressure-sensitive adhesive layer 4 is formed by applying the pressure-sensitive adhesive material 2 and drying it to remove the solvent.
　これにより、熱伝導性粘着シートを得る。 Thereby, a heat conductive adhesive sheet is obtained.
　得られた熱伝導性粘着シートのアクリル系粘着剤層４の厚みは、例えば、１０μｍ以上、好ましくは、５０μｍ以上、より好ましくは、１００μｍ以上であり、また、例えば、１００００μｍ以下、好ましくは、５０００μｍ以下、より好ましくは、３０００μｍ以下でもある。 The thickness of the acrylic pressure-sensitive adhesive layer 4 of the obtained heat conductive pressure-sensitive adhesive sheet is, for example, 10 μm or more, preferably 50 μm or more, more preferably 100 μm or more, and for example, 10,000 μm or less, preferably 5000 μm. Hereinafter, more preferably, it is 3000 μm or less.
　アクリル系粘着剤層４の厚みを１０μｍ以上とすることにより、より良好な接着力を得ることができる。また、アクリル系粘着剤層４の厚みを１００００μｍ以下とすることにより、より良好な熱伝導性を得ることができる。 By setting the thickness of the acrylic pressure-sensitive adhesive layer 4 to 10 μm or more, better adhesive force can be obtained. Further, by setting the thickness of the acrylic pressure-sensitive adhesive layer 4 to 10000 μm or less, better thermal conductivity can be obtained.
　また、得られた熱伝導性粘着シートは、アクリル系粘着剤層４に対する熱伝導性粒子の含有割合が、５５体積％以上、好ましくは、６０体積％以上であり、また、７５体積％以下、好ましくは、７０体積％以下でもある。 Further, in the obtained heat conductive pressure-sensitive adhesive sheet, the content ratio of the heat conductive particles to the acrylic pressure-sensitive adhesive layer 4 is 55% by volume or more, preferably 60% by volume or more, and 75% by volume or less. Preferably, it is also 70 volume% or less.
　熱伝導性粒子の含有割合が５５体積％未満であると、十分な熱伝導性を得ることができない。一方、熱伝導性粒子の含有割合が７５体積％を超過すると、シートとしての形状を保つことができない。 When the content ratio of the heat conductive particles is less than 55% by volume, sufficient heat conductivity cannot be obtained. On the other hand, when the content ratio of the heat conductive particles exceeds 75% by volume, the shape as a sheet cannot be maintained.
　金属酸化物または金属窒化物（好ましくは、酸化アルミニウム、酸化マグネシウムまたは窒化ホウ素）からなる熱伝導性粒子の含有割合は、アクリル系粘着剤層４に対して、例えば、５体積％以上、好ましくは、８体積％以上であり、また、例えば、２５体積％以下、好ましくは、２０体積％以下でもある。金属酸化物または金属窒化物の含有割合が上記範囲であると、熱伝導性、難燃性が良好となる。 The content ratio of the heat conductive particles made of metal oxide or metal nitride (preferably, aluminum oxide, magnesium oxide, or boron nitride) is, for example, 5% by volume or more with respect to the acrylic pressure-sensitive adhesive layer 4, preferably 8 volume% or more, and for example, 25 volume% or less, preferably 20 volume% or less. When the content ratio of the metal oxide or metal nitride is in the above range, the thermal conductivity and flame retardancy are good.
　金属水酸化物からなる熱伝導性粒子の含有割合は、アクリル系粘着剤層４に対して、例えば、３０体積％以上、好ましくは、４０体積％以上であり、また、例えば、７０体積％以下、好ましくは、６０体積％以下である。
　また、得られた熱伝導粘着シートは、好ましくは、平均粒子径３μｍ未満の第１熱伝導性粒子と、平均粒子径３μｍ以上７０μｍ未満の第２熱伝導性粒子と、平均粒子径７０μｍ以上の第３熱伝導性粒子および／または平均粒子径３μｍ以上７０μｍ未満で鱗片状である第４熱伝導性粒子とを含有している。 The content ratio of the heat conductive particles made of metal hydroxide is, for example, 30% by volume or more, preferably 40% by volume or more, and, for example, 70% by volume or less with respect to the acrylic pressure-sensitive adhesive layer 4. Preferably, it is 60 volume% or less.
The obtained heat conductive pressure-sensitive adhesive sheet preferably has first heat conductive particles having an average particle diameter of less than 3 μm, second heat conductive particles having an average particle diameter of 3 μm or more and less than 70 μm, and an average particle diameter of 70 μm or more. 3rd heat conductive particle and / or 4th heat conductive particle which is a scaly shape with an average particle diameter of 3 micrometers or more and less than 70 micrometers are contained.
　また、得られた熱伝導性粘着シートの９０度剥離接着力（ステンレス鋼板に接着した後、ステンレス鋼板に対して剥離角度９０度で剥離速度３００ｍｍ／分剥離したときの接着力）は、例えば、３Ｎ／２０ｍｍ以上、好ましくは、１０Ｎ／２０ｍｍ以上、より好ましくは、１５Ｎ／２０ｍｍ以上であり、例えば、１００Ｎ／２０ｍｍ以下である。 Moreover, 90 degree peeling adhesive strength of the obtained heat conductive adhesive sheet (adhesive force when peeling to a stainless steel plate and peeling rate of 300 mm / min at a peeling angle of 90 degrees with respect to the stainless steel plate) is, for example, 3N / 20mm or more, preferably 10N / 20mm or more, more preferably 15N / 20mm or more, for example, 100N / 20mm or less.
　また、得られた熱伝導性粘着シートの硬度（ＪＩＳ　Ｋ　７３１２に規定されるタイプＣ硬さ試験に準じて測定する。）は、タイプＣデュロメータの加圧面を密着させてから３
０秒後に測定したときに、例えば、８０以下、好ましくは、７０以下であり、また、例えば、２０以上、好ましくは、３０以上である。 Further, the hardness (measured according to the type C hardness test specified in JIS K 7312) of the obtained heat conductive adhesive sheet is 3 after the pressure surface of the type C durometer is brought into close contact.
When measured after 0 seconds, it is, for example, 80 or less, preferably 70 or less, and for example, 20 or more, preferably 30 or more.
　硬度が上記範囲であると、段差追従性、作業性が良好である。 If the hardness is in the above range, the step following ability and workability are good.
　また、得られた熱伝導性粘着シートのアクリル系粘着剤層４の熱伝導率（後述の実施例に記載の方法により測定する。）は、例えば、１．７Ｗ／ｍ・Ｋ以上、好ましくは、２．０Ｗ／ｍ・Ｋ以上、さら好ましくは、２．５Ｗ／ｍ・Ｋ以上であり、例えば、１０Ｗ／ｍ・Ｋ以下である。　 The thermal conductivity of the acrylic pressure-sensitive adhesive layer 4 of the obtained heat conductive pressure-sensitive adhesive sheet (measured by the method described in Examples below) is, for example, 1.7 W / m · K or more, preferably 2.0 W / m · K or more, more preferably 2.5 W / m · K or more, for example, 10 W / m · K or less. *
　また、得られた熱伝導性粘着シートは、例えば、難燃性ＵＬ９４規格がＶ－０である。熱伝導性粘着シートは、難燃性ＵＬ９４規格がＶ－０であると、難燃性に優れる。 The obtained heat conductive pressure-sensitive adhesive sheet is, for example, flame retardant UL94 standard V-0. A heat conductive adhesive sheet is excellent in flame retardancy when the flame retardancy UL94 standard is V-0.
　この熱伝導性粘着シートは、アクリル系粘着剤層４を備えている。そのため、そのアクリル系粘着剤層４は、その両面において、タック性を備えている。従って、両面性の粘着（感圧接着）シートとして使用することができる。 This heat conductive adhesive sheet includes an acrylic adhesive layer 4. Therefore, the acrylic pressure-sensitive adhesive layer 4 has tackiness on both sides. Therefore, it can be used as a double-sided pressure-sensitive adhesive (pressure-sensitive adhesive) sheet.
　また、この熱伝導性粘着シートでは、アクリル系粘着剤層４が、平均粒子径が異なる３種以上の熱伝導性粒子を含有し、３種以上の熱伝導性粒子を混合したときの空間率が、７２％以下であり、アクリル系粘着剤層４に対する３種以上の熱伝導性粒子の含有割合が、５５体積％以上７５体積％以下である。 Moreover, in this heat conductive adhesive sheet, the acrylic adhesive layer 4 contains three or more types of heat conductive particles having different average particle diameters, and the space ratio when three or more types of heat conductive particles are mixed. However, it is 72% or less, and the content rate of 3 or more types of heat conductive particles with respect to the acrylic adhesive layer 4 is 55 volume% or more and 75 volume% or less.
　この熱伝導性粘着シートによれば、そのアクリル系粘着剤層４に熱伝導性粒子が適度な距離を保ちながら密に充填されているため、アクリル系粘着剤層４が変形する際にも、熱伝導性粒子同士の接触または干渉が抑制される。よって、優れた熱伝導性および良好な硬度（適度な柔らかさ）を兼ね備えている。さらには、良好な難燃性も備えている。 According to this heat conductive pressure-sensitive adhesive sheet, the acrylic pressure-sensitive adhesive layer 4 is closely packed with the heat conductive particles while maintaining an appropriate distance. Therefore, even when the acrylic pressure-sensitive adhesive layer 4 is deformed, Contact or interference between the thermally conductive particles is suppressed. Therefore, it has excellent thermal conductivity and good hardness (appropriate softness). Furthermore, it also has good flame retardancy.
　また、上記した熱伝導性粘着シートの製造方法は、（メタ）アクリル酸アルキルエステルを主成分とするモノマー成分（モノマー組成物）に、平均粒子径が異なる３種以上である熱伝導性粒子を混合して、粘着剤原料２を得る工程、および粘着剤原料２を反応させ、アクリル系粘着剤層４を得る工程を備えている。 Moreover, the manufacturing method of an above described heat conductive adhesive sheet is the monomer component (monomer composition) which has (meth) acrylic-acid alkylester as a main component, and the heat conductive particle which is 3 or more types from which an average particle diameter differs. A step of mixing to obtain the pressure-sensitive adhesive raw material 2 and a step of reacting the pressure-sensitive adhesive raw material 2 to obtain the acrylic pressure-sensitive adhesive layer 4 are provided.
　そのため、粘着剤原料２をベースフィルム１に塗布して、アクリル系粘着剤層４を形成することができるので、熱プレスなどの圧縮工程を実施せずとも、熱伝導性粒子が密に充填され、熱伝導性粒子間に発生する隙間（モノマー成分やポリマー成分などが充填される箇所）を減らすことができる。そのため、優れた熱伝導性を備える熱伝導性粘着シートを簡便に製造することができる。 Therefore, since the pressure-sensitive adhesive material 2 can be applied to the base film 1 to form the acrylic pressure-sensitive adhesive layer 4, the heat conductive particles are densely packed without performing a compression step such as hot pressing. , Gaps generated between the thermally conductive particles (location where the monomer component or polymer component is filled) can be reduced. Therefore, a heat conductive adhesive sheet provided with the outstanding heat conductivity can be manufactured simply.
　また、この熱伝導性粘着シートは、熱伝導性と難燃性とに優れるため、半導体装置、ハードディスク、ＬＥＤ装置（テレビジョン、照明、ディスプレイなど）、ＥＬ装置（有機ＥＬディスプレイ、有機ＥＬ照明など）、キャパシタやコンデンサ、バッテリー（リチウムイオンバッテリーなど）、パワーモジュールなどの用途に好適に用いることができる。 Moreover, since this heat conductive adhesive sheet is excellent in heat conductivity and a flame retardance, it is a semiconductor device, a hard disk, LED device (television, illumination, a display, etc.), EL device (organic EL display, organic EL illumination, etc.) ), Capacitors, capacitors, batteries (such as lithium ion batteries), and power modules.
　以下、本発明を各実施例および各比較例に基づいて説明するが、本発明はこれらの実施例および比較例によって何ら限定されるものではない。 Hereinafter, the present invention will be described based on each example and each comparative example, but the present invention is not limited to these examples and comparative examples.
　なお、以下に示す実施例の数値は、上記の実施形態において記載される数値（すなわち、上限値または下限値）に代替することができる。 In addition, the numerical value of the Example shown below can be substituted with the numerical value (namely, upper limit value or lower limit value) described in said embodiment.
　各実施例および各比較例で用いる測定方法の詳細を次に記載する。
・熱伝導性粒子の平均粒子径：下記に従い測定した。 Details of the measurement methods used in each example and each comparative example are described below.
-Average particle diameter of thermally conductive particles: measured according to the following.
　レーザー散乱法における粒度分布測定用によって求められる（具体的には、レーザー散乱式粒度分布計（商品名ＳＡＬＤ－２１００、島津製作所社製）により計測する粒度分布に基づいて、Ｄ５０値（累積５０％メジアン径）として求められる。
・熱伝導性粒子の空隙率（％）
　熱伝導性粒子の空間率を下記の式に従って、算出した。 D50 value (accumulated 50% based on the particle size distribution measured by a laser scattering particle size distribution meter (trade name SALD-2100, manufactured by Shimadzu Corporation)). Median diameter).
-Porosity of thermally conductive particles (%)
The space ratio of the heat conductive particles was calculated according to the following formula.
　空間率（％）＝１００－｛（タップ密度）／（熱伝導性粒子の真密度）｝×１００
　タップ密度は、パウダーテスタ「ＰＴ－Ｒ」（ホソカワミクロン社製）を用いて、測定モードとして「固めかさ密度」測定を選択することにより、測定した。詳しくは、目開き１．１ｍｍのふるいを用いて、熱伝導性粒子をカップに充填し、次いで、タッピングストロークを１８ｍｍとして、３６０回タッピングした。タッピング終了後、カップ上部を平板で擦切り、カップに充填された熱伝導性粒子の質量から、タップ密度を求めた。 Space ratio (%) = 100 − {(tap density) / (true density of thermally conductive particles)} × 100
The tap density was measured using a powder tester “PT-R” (manufactured by Hosokawa Micron Co., Ltd.) by selecting “hardened bulk density” measurement as the measurement mode. Specifically, the heat conductive particles were filled in the cup using a sieve having an aperture of 1.1 mm, and then tapped 360 times with a tapping stroke of 18 mm. After tapping, the upper part of the cup was scraped with a flat plate, and the tap density was determined from the mass of the thermally conductive particles filled in the cup.
　熱伝導性粒子の真密度は、乾式密度計（商品名アキュピック１３３０、島津製作所社製）（ガス置換法）により算出した。 The true density of the thermally conductive particles was calculated by a dry density meter (trade name Accupic 1330, manufactured by Shimadzu Corporation) (gas displacement method).
　異なる材料を含有する熱伝導性粒子の場合は、各熱伝導性粒子の真密度および配合割合より、理論真密度を算出した。この値を表１に示す。 In the case of thermally conductive particles containing different materials, the theoretical true density was calculated from the true density and blending ratio of each thermally conductive particle. This value is shown in Table 1.
　　１．実施例および比較例
　　実施例１
（モノマー組成物の調製）
　（メタ）アクリル酸アルキルエステルとして、アクリル酸２－エチルヘキシル（２ＥＨＡ）８２質量部と、アクリル酸２－メトキシエチル（ＭＥＡ）１２質量部と、極性基含有モノマーとして、Ｎ－ビニル－２－ピロリドン（ＮＶＰ）５質量部およびヒドロキシエチルアクリルアミド（ＨＥＡＡ）１質量部とを配合し、混合して、モノマー成分を得た。 1. Examples and Comparative Examples Example 1
(Preparation of monomer composition)
As (meth) acrylic acid alkyl ester, 82 parts by mass of 2-ethylhexyl acrylate (2EHA), 12 parts by mass of 2-methoxyethyl acrylate (MEA), and as a polar group-containing monomer, N-vinyl-2-pyrrolidone ( NVP) 5 parts by mass and hydroxyethyl acrylamide (HEAA) 1 part by mass were blended and mixed to obtain a monomer component.
　得られたモノマー成分に、光重合開始剤として商品名「イルガキュア６５１」（２，２－ジメトキシ－１，２－ジフェニルエタン－１－オン、チバ・ジャパン社製）０．１０質量部および商品名「イルガキュア１８４」（１－ヒドロキシシクロヘキシルフェニルケトン、チバ・ジャパン社製）０．０５質量部を配合した。 To the obtained monomer component, 0.10 parts by mass of a trade name “Irgacure 651” (2,2-dimethoxy-1,2-diphenylethane-1-one, manufactured by Ciba Japan) as a photopolymerization initiator and a trade name 0.05 parts by mass of “Irgacure 184” (1-hydroxycyclohexyl phenyl ketone, manufactured by Ciba Japan) was blended.
　その後、混合物に、粘度（ＢＨ粘度計Ｎｏ．５ロータ、１０ｒｐｍ、測定温度３０℃）が約２０Ｐａ・ｓになるまで紫外線を照射して、モノマーの一部が重合した部分重合物（シロップ状）を調製した。 Thereafter, the mixture was irradiated with ultraviolet rays until the viscosity (BH viscometer No. 5 rotor, 10 rpm, measurement temperature 30 ° C.) reached about 20 Pa · s, and a partial polymer obtained by polymerizing a part of the monomer (syrup shape). Was prepared.
　調製した部分重合物に、架橋剤として、ＤＰＨＡ（ジペンタエリスリトールヘキサアクリレート、商品名「ＫＡＹＡＲＡＤ　ＤＰＨＡ－４０Ｈ」、日本化薬社製）０．０５質量部と、分散剤として、商品名「プライサーフＡ２１２Ｅ」（第一工業製薬社製）３質量部とを配合し、混合して、モノマー組成物を得た。 In the prepared partial polymer, 0.05 mass parts of DPHA (dipentaerythritol hexaacrylate, trade name “KAYARAD DPHA-40H”, manufactured by Nippon Kayaku Co., Ltd.) is used as a crosslinking agent, and the trade name “Plisurf” is used as a dispersant. A212E ”(Daiichi Kogyo Seiyaku Co., Ltd.) 3 parts by mass was blended and mixed to obtain a monomer composition.
　（粘着剤原料の調製）
　得られたモノマー組成物に、熱伝導性粒子として、ハイジライトＨ－４２（商品名、昭和電工社製、水酸化アルミニウム、平均粒子径１μｍ、破砕状）２６６質量部、ハイジライトＨ－１０（商品名、昭和電工社製、水酸化アルミニウム、平均粒子径５５μｍ、破砕状）７４質量部、および、ＡＬ－１３ＫＴ（商品名、昭和電工社製、平均粒子径９７μｍ、凝集体）８５質量部を配合し、混合して、粘着剤原料を得た。 (Preparation of adhesive material)
To the obtained monomer composition, 266 parts by mass of Heidilite H-10 (trade name, manufactured by Showa Denko KK, aluminum hydroxide, average particle diameter 1 μm, crushed) as heat conductive particles, Heidilite H-10 ( 74 parts by mass of trade name, Showa Denko, aluminum hydroxide, average particle diameter 55 μm, crushed, and 85 parts by mass of AL-13KT (trade name, Showa Denko, average particle diameter 97 μm, aggregate) It mix | blended and mixed and the adhesive raw material was obtained.
　（熱伝導性粘着シートの作製）
　得られた粘着剤原料を、片面に剥離処理が施されているベースフィルム（ポリエチレンテレフタレートフィルム、商品名「ダイアホイルＭＲＦ３８」、三菱化学ポリエステルフィルム社製）の剥離処理面に、乾燥及び硬化後の厚みが１０００μｍとなるように塗布した（図１（ａ）参照）。 (Preparation of heat conductive adhesive sheet)
The obtained adhesive material is dried and cured on the release surface of a base film (polyethylene terephthalate film, trade name “Diafoil MRF38”, manufactured by Mitsubishi Chemical Polyester Film Co., Ltd.) that has been subjected to release treatment on one side. It applied so that thickness might be set to 1000 micrometers (refer Fig.1 (a)).
　次いで、ベースフィルムとの間に粘着剤原料の塗膜を挟むように、粘着剤原料の塗膜の上に、カバーフィルム（ベースフィルムと同じフィルム）を配置した（図１（ｂ）参照）。 Next, a cover film (the same film as the base film) was placed on the adhesive material coating film so that the adhesive material coating film was sandwiched between the base film (see FIG. 1B).
　次いで、粘着剤原料に、両側（ベースフィルム側およびカバーフィルム側）から紫外線（照度約５ｍＷ／ｃｍ２）を３分間（照射エネルギー９００ｍＪ／ｃｍ２に相当）照射した。 Next, the adhesive raw material was irradiated with ultraviolet rays (illuminance of about 5 mW / cm 2 ) for 3 minutes (corresponding to an irradiation energy of 900 mJ / cm 2 ) from both sides (base film side and cover film side).
　これにより、粘着剤原料中のモノマー成分を重合させて、アクリル系粘着剤層を形成し、熱伝導性粘着シートを作製した（図１（ｃ）参照）。 Thereby, the monomer component in the pressure-sensitive adhesive raw material was polymerized to form an acrylic pressure-sensitive adhesive layer, and a heat conductive pressure-sensitive adhesive sheet was produced (see FIG. 1C).
　実施例１の熱伝導性粘着シートの粘着剤層は、その表面および裏面において、タック性を有した。このことから、両面粘着シートであることが確認できた。 The pressure-sensitive adhesive layer of the thermally conductive pressure-sensitive adhesive sheet of Example 1 had tackiness on the front and back surfaces. From this, it has confirmed that it was a double-sided adhesive sheet.
　粘着剤層中における熱伝導性粒子の配合割合（質量％、体積％）、粘着剤層中における水酸化アルミニウムの配合割合（体積％）、粘着剤層中における金属酸化物および金属窒化物（具体的には、酸化アルミニウム、酸化マグネシウムおよび窒化ホウ素）の配合割合（体積％）、および、熱伝導性粒子の空間率を、表１に示す。 Mixing ratio (mass%, volume%) of thermally conductive particles in the pressure-sensitive adhesive layer, mixing ratio (volume%) of aluminum hydroxide in the pressure-sensitive adhesive layer, metal oxide and metal nitride in the pressure-sensitive adhesive layer (specific) Specifically, Table 1 shows the blending ratio (volume%) of aluminum oxide, magnesium oxide and boron nitride, and the space ratio of the thermally conductive particles.
　　実施例２～６
　熱伝導性粒子の種類及びその配合割合を表１に示す配合割合とした以外は、実施例１と同様にして、熱伝導性粘着シートを作製した。 Examples 2 to 6
A thermally conductive pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the kind of thermally conductive particles and the blending ratio thereof were changed to the blending ratios shown in Table 1.
　各実施例の熱伝導性粘着シートの粘着剤層はいずれも、その表面および裏面において、タック性を有した。このことから、両面粘着シートであることが確認できた。 Each of the pressure-sensitive adhesive layers of the heat conductive pressure-sensitive adhesive sheet of each example had tackiness on the front surface and the back surface. From this, it has confirmed that it was a double-sided adhesive sheet.
　粘着剤層中における熱伝導性粒子の配合割合（質量％、体積％）、粘着剤層中における水酸化アルミニウムの配合割合（体積％）、粘着剤層中における金属酸化物および金属窒化物の配合割合（体積％）、および、熱伝導性粒子の空間率を、表１に示す。 Blending ratio of heat conductive particles in the pressure-sensitive adhesive layer (mass%, volume%), blending ratio of aluminum hydroxide in the pressure-sensitive adhesive layer (volume%), blending of metal oxide and metal nitride in the pressure-sensitive adhesive layer Table 1 shows the ratio (volume%) and the space ratio of the thermally conductive particles.
　　比較例１～４
　熱伝導性粒子の種類及びその配合割合を表１に示す配合割合とした以外は、実施例１と同様にして、熱伝導性粘着シートを作製した。なお、比較例４においては、比較例４に記載の配合割合における粘着剤原料では、シート状に形成することができなかった。 Comparative Examples 1 to 4
A thermally conductive pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that the kind of thermally conductive particles and the blending ratio thereof were changed to the blending ratios shown in Table 1. In Comparative Example 4, the pressure-sensitive adhesive material in the blending ratio described in Comparative Example 4 could not be formed into a sheet shape.
　各比較例の熱伝導性粘着シートの粘着剤層はいずれも、その表面および裏面において、タック性を有した。このことから、両面粘着シートであることが確認できた。 Each adhesive layer of the heat conductive adhesive sheet of each comparative example had tackiness on the front surface and the back surface. From this, it has confirmed that it was a double-sided adhesive sheet.
　粘着剤層中における熱伝導性粒子の配合割合（質量％、体積％）、粘着剤層中における水酸化アルミニウムの配合割合（体積％）、粘着剤層中における金属酸化物および金属窒化物の配合割合（体積％）、および、熱伝導性粒子の空間率を、表１に示す。 Blending ratio of heat conductive particles in the pressure-sensitive adhesive layer (mass%, volume%), blending ratio of aluminum hydroxide in the pressure-sensitive adhesive layer (volume%), blending of metal oxide and metal nitride in the pressure-sensitive adhesive layer Table 1 shows the ratio (volume%) and the space ratio of the thermally conductive particles.
　　２．評価
　（熱伝導率）
　熱伝導性テープの熱伝導率を測定した。すなわち、厚み方向（ＴＤ）における熱伝導率を、キセノンフラッシュアナライザー「ＬＦＡ－４４７型」（ＮＥＴＺＳＣＨ社製）を用いるパルス加熱法により測定した。 2. Evaluation (thermal conductivity)
The thermal conductivity of the thermally conductive tape was measured. That is, the thermal conductivity in the thickness direction (TD) was measured by a pulse heating method using a xenon flash analyzer “LFA-447 type” (manufactured by NETZSCH).
　熱伝導性粘着シートを、１ｃｍ×１ｃｍの正方形に切り出して切片を得、切片の表面（厚み方向一方面）に熱伝導性シートカーボンスプレー（カーボンのアルコール分散溶液）を塗布して乾燥し、かかる部分を受光部とし、裏面（厚み方向他方面）にカーボンスプレーを塗布して、これを検出部とした。 The heat conductive adhesive sheet is cut into a 1 cm × 1 cm square to obtain a section, and the surface of the section (one surface in the thickness direction) is coated with a heat conductive sheet carbon spray (carbon alcohol dispersion) and dried. The portion was used as a light receiving portion, and carbon spray was applied to the back surface (the other surface in the thickness direction) to form a detection portion.
　次いで、受光部に、キセノンフラッシュによりエネルギー線を照射して、検出部の温度を検出することによって、厚み方向の熱拡散率（Ｄ１）を測定した。 Then, the thermal diffusivity (D1) in the thickness direction was measured by irradiating the light receiving part with an energy ray by a xenon flash and detecting the temperature of the detecting part.
　得られた熱拡散率（Ｄ１）から、次式によって、熱伝導性粘着シートの厚み方向の熱伝導率（ＴＣ１）を求めた。この結果を表１に示す。 From the obtained thermal diffusivity (D1), the thermal conductivity (TC1) in the thickness direction of the thermally conductive adhesive sheet was determined by the following formula. The results are shown in Table 1.
　　　　　　　　ＴＣ１＝Ｄ１×ρ×Ｃｐ
　ρ　：　熱伝導性テープの２５℃における密度（試料を２．５ｃｍφに打ち抜き、厚み・重量から密度を算出した）
　Ｃｐ　：　熱伝導性テープの比熱（比熱はＤＳＣにより下記比熱容量測定により測定した。）
　（比熱容量測定）
　比熱容量の測定を、示差走査熱量測定装置（以下ＤＳＣ）「ＥＸＳＴＡＲ６２００」（セイコーインスツル社製）を用いて、下記条件にて行った。 TC1 = D1 × ρ × Cp
ρ: density of heat conductive tape at 25 ° C. (sample was punched to 2.5 cmφ, and density was calculated from thickness and weight)
Cp: Specific heat of the heat conductive tape (specific heat was measured by DSC by the following specific heat capacity measurement)
(Specific heat capacity measurement)
The specific heat capacity was measured using a differential scanning calorimeter (hereinafter DSC) “EXSTAR 6200” (manufactured by Seiko Instruments Inc.) under the following conditions.
　ＤＳＣを用いて、比熱容量を測定する場合、次式にて算出することが可能である。 When measuring the specific heat capacity using DSC, it can be calculated by the following equation.
　Ｃｐ＝ｈ／Ｈ・ｍ′／ｍ・Ｃ′ｐ
　Ｃｐ　：　熱伝導性テープの比熱容量（Ｊ／ｇ℃）
　Ｃ′ｐ　：　基準物質の比熱容量（Ｊ／ｇ℃）
　ｈ　　　：　空容器と熱伝導テープのＤＳＣ曲線の差
　Ｈ　　　：　空容器と基準物質のＤＳＣ曲線の差
　ｍ　　　：　熱伝導テープ重量（ｇ）
　ｍ′　　：　基準物質重量（ｇ）
　基準物質としては、サファイヤを用いて測定を行い（２５℃における比熱容量は、０．７５Ｊ／ｇ℃）、空容器、サファイヤ、熱伝導テープそれぞれを、－１５℃にて５分間等温保持した後、１０℃／分の速度で昇温、６５℃に到達した後、５分間等温保持した。これにより、空容器、サファイヤ、熱伝導テープそれぞれのＤＳＣ曲線を得て、上式により２５℃における熱伝導テープの比熱容量を求めた。この操作を三回繰り返し、これらの平均値を比熱容量として用いた。 Cp = h / H · m ′ / m · C′p
Cp: specific heat capacity of heat conductive tape (J / g ° C)
C′p: specific heat capacity of reference material (J / g ° C.)
h: Difference in DSC curve between empty container and heat conduction tape H: Difference in DSC curve between empty container and reference material m: Weight of heat conduction tape (g)
m ′: reference substance weight (g)
As a reference material, measurement was performed using sapphire (specific heat capacity at 25 ° C. is 0.75 J / g ° C.), and each of the empty container, sapphire, and heat conductive tape was kept isothermal at −15 ° C. for 5 minutes. The temperature was raised at a rate of 10 ° C./min, and after reaching 65 ° C., the temperature was kept isothermal for 5 minutes. As a result, DSC curves of the empty container, sapphire, and heat conductive tape were obtained, and the specific heat capacity of the heat conductive tape at 25 ° C. was obtained from the above equation. This operation was repeated three times, and the average value was used as the specific heat capacity.
　（硬度）
　各実施例および各比較例の熱伝導性粘着シートを用いて、ＪＩＳ　Ｋ　７３１２（１９９６）に準じて、下記条件にて試験を実施した。 (hardness)
The test was carried out under the following conditions in accordance with JIS K 7312 (1996) using the heat conductive adhesive sheet of each example and each comparative example.
　詳しくは、熱伝導性粘着シートの粘着剤層を幅２０ｍｍ、長さ２０ｍｍに切断し、厚みが４ｍｍになるように積層させたものを評価用サンプルとして、アスカーＣ硬度計（高分子計器社製）で、２３℃、５０％ＲＨ雰囲気下において、アスカーＣ硬度計の加圧面を密着させてから３０秒後の硬さ（アスカーＣ硬度）を測定した。この結果を表１に示す。 Specifically, an evaluation sample was prepared by cutting the pressure-sensitive adhesive layer of the heat-conductive pressure-sensitive adhesive sheet into a width of 20 mm and a length of 20 mm, and laminating it so as to have a thickness of 4 mm. ), The hardness (Asker C hardness) 30 seconds after the pressure surface of the Asker C hardness tester was brought into close contact under an atmosphere of 23 ° C. and 50% RH. The results are shown in Table 1.
　（難燃性）
　各実施例および比較例で作製した熱伝導性粘着シートを、１２．７ｍｍ×１２７ｍｍの大きさにカットし、ベースフィルムおよびカバーフィルムを剥がして、それぞれ５つの試験片を作製し、ＵＬ９４難燃性試験を実施した。 (Flame retardance)
The heat conductive adhesive sheet prepared in each example and comparative example was cut into a size of 12.7 mm × 127 mm, the base film and the cover film were peeled off, and five test pieces were prepared, respectively. The test was conducted.
　詳しくは、それらの試験片を、その上端を固定して下端を垂下させた。そして、試験片の下端に、まず、１０秒間、バーナーの炎を当て、その後、炎を試験片から離した後、再度、試験片の下端に、１０秒間、炎を当てた。 Specifically, the upper ends of these test pieces were fixed and the lower ends were suspended. Then, the flame of the burner was first applied to the lower end of the test piece for 10 seconds, and then the flame was released from the test piece, and then the flame was applied again to the lower end of the test piece for 10 seconds.
　そして、以下の評価基準に従って、Ｖ－０規格の合否を評価した。この結果を表１に示す。 And the pass / fail of the V-0 standard was evaluated according to the following evaluation criteria. The results are shown in Table 1.
　１：各試験片の合計有炎燃焼時間（最初の炎をあてた後の燃焼時間と、２回目の炎をあてた後の燃焼時間の合計）が１０秒以内である。 1: The total flammable combustion time of each test piece (the total of the combustion time after applying the first flame and the combustion time after applying the second flame) is within 10 seconds.
　２：各試験片５つの合計有炎燃焼時間の総計が５０秒以内である。 2: The total of the total flammable combustion time of each test piece is within 50 seconds.
　３：２回目に炎をあてた後の各試験片の有炎燃焼時間および無炎燃焼時間が３０秒以内である。 3: The flame burning time and the flameless burning time of each test piece after applying the flame for the second time are within 30 seconds.
　４：試験片から燃焼滴下物が落下した場合に、下に配置された綿に着火しない。 4: When the combustion drop falls from the test piece, the cotton placed below does not ignite.
　５：各試験片はいずれもその吊り下げ部分まで燃え尽きない。 5: Each test piece does not burn up to its suspended part.
　　○：上記した１～５を満たす評価項目数が３個以上であり、Ｖ－０規格を満たしている。 ○: The number of evaluation items satisfying the above 1 to 5 is 3 or more and satisfies the V-0 standard.
　　×：上記した１～５を満たす評価項目数が３個未満であり、Ｖ－０規格を満たしていない。 X: The number of evaluation items that satisfy the above 1 to 5 is less than 3, and the V-0 standard is not satisfied.
Figure JPOXMLDOC01-appb-T000001
 
Figure JPOXMLDOC01-appb-T000001
 
　なお、モノマー成分、重合開始剤、架橋剤および分散剤の単位は、質量部である。 In addition, the unit of a monomer component, a polymerization initiator, a crosslinking agent, and a dispersant is part by mass.
　また、表中、各成分について、以下にその詳細を記載する。
・ハイジライトＨ－４２：商品名、昭和電工社製、水酸化アルミニウム、平均粒子径１μｍ、破砕状、真密度２．４ｇ／ｃｍ３
・ＢＥ０３３：商品名、日本軽金属社製、水酸化アルミニウム、平均粒子径３μｍ、破砕状、真密度２．４ｇ／ｃｍ３
・ハイジライトＨ－３１：商品名、昭和電工社製、水酸化アルミニウム、平均粒子径１８μｍ、破砕状）、真密度２．４ｇ／ｃｍ３
・ハイジライトＨ－１０：商品名、昭和電工社製、水酸化アルミニウム、平均粒子径５５μｍ、破砕状、真密度２．４ｇ／ｃｍ３
・ＭＣＰ５２４－５０：商品名、宇部マテリアルズ社製、酸化マグネシウム、平均粒子径５０μｍ、球状、真密度３．６ｇ／ｃｍ３
・ＡＬ－１３ＫＴ：商品名、昭和電工社製、酸化アルミニウム、平均粒子径９７μｍ、凝集体、真密度４．０ｇ／ｃｍ３
・ＰＴ１１０：商品名モメンティブ社製、窒化ホウ素、平均粒子径３５μｍ、鱗片状、真密度２．３ｇ／ｃｍ３
　なお、上記発明は、本発明の例示の実施形態として提供したが、これは単なる例示に過ぎず、限定的に解釈してはならない。当該技術分野の当業者によって明らかな本発明の変形例は、後記特許請求の範囲に含まれる。 Moreover, the detail is described below about each component in a table | surface.
・ Hijilite H-42: trade name, manufactured by Showa Denko KK, aluminum hydroxide, average particle size 1 μm, crushed, true density 2.4 g / cm 3
BE033: trade name, manufactured by Nippon Light Metal Co., Ltd., aluminum hydroxide, average particle size 3 μm, crushed, true density 2.4 g / cm 3
・ Hijilite H-31: trade name, manufactured by Showa Denko KK, aluminum hydroxide, average particle diameter 18 μm, crushed), true density 2.4 g / cm 3
・ Hijilite H-10: trade name, manufactured by Showa Denko KK, aluminum hydroxide, average particle size 55 μm, crushed, true density 2.4 g / cm 3
MCP524-50: trade name, manufactured by Ube Materials, magnesium oxide, average particle size 50 μm, spherical, true density 3.6 g / cm 3
AL-13KT: trade name, manufactured by Showa Denko KK, aluminum oxide, average particle size 97 μm, aggregate, true density 4.0 g / cm 3
PT110: trade name manufactured by Momentive, Boron nitride, average particle size 35 μm, scaly, true density 2.3 g / cm 3
In addition, although the said invention was provided as exemplary embodiment of this invention, this is only a mere illustration and should not be interpreted limitedly. Variations of the present invention that are apparent to one of ordinary skill in the art are within the scope of the following claims.
　本発明の熱伝導性粘着シートは、各種の工業製品に適用することができ、例えば、半導体装置、ハードディスク、ＬＥＤ装置、ＥＬ装置、キャパシタやコンデンサ、バッテリー、パワーモジュールなどに貼着する放熱シートなどが挙げられる。
  The heat conductive pressure-sensitive adhesive sheet of the present invention can be applied to various industrial products, such as a semiconductor device, a hard disk, an LED device, an EL device, a heat dissipation sheet attached to a capacitor, a capacitor, a battery, a power module, and the like. Is mentioned.

Claims (12)

  1. 　アクリル系粘着剤層を備え、
    　前記アクリル系粘着剤層は、平均粒子径が異なる３種以上の熱伝導性粒子を含有し、
    　前記３種以上の熱伝導性粒子を混合したときの空間率が、７２％以下であり、　
    　前記アクリル系粘着剤層に対する前記３種以上の熱伝導性粒子の含有割合が、５５体積％以上７５体積％以下である
    　ことを特徴する、熱伝導性粘着シート。     With an acrylic adhesive layer,
    The acrylic pressure-sensitive adhesive layer contains three or more kinds of thermally conductive particles having different average particle sizes,
    The space ratio when mixing the three or more kinds of heat conductive particles is 72% or less,
    The heat conductive adhesive sheet characterized by the content rate of the said 3 or more types of heat conductive particle with respect to the said acrylic adhesive layer being 55 volume% or more and 75 volume% or less.
  2. 　前記３種以上の熱伝導性粒子のうち少なくとも１種の熱伝導性粒子は、金属酸化物または金属窒化物からなり、それ以外の熱伝導性粒子は、金属水酸化物からなることを特徴とする、請求項１に記載の熱伝導性粘着シート。 Of the three or more types of thermally conductive particles, at least one of the thermally conductive particles is made of a metal oxide or a metal nitride, and the other thermally conductive particles are made of a metal hydroxide. The thermally conductive adhesive sheet according to claim 1.
  3. 　前記金属酸化物または金属窒化物からなる熱伝導性粒子の含有割合が、前記アクリル系粘着剤層に対して、５体積％以上２５体積％以下であることを特徴とする、請求項２に記載の熱伝導性粘着シート。 The content ratio of the thermally conductive particles made of the metal oxide or metal nitride is 5% by volume or more and 25% by volume or less with respect to the acrylic pressure-sensitive adhesive layer. Heat conductive adhesive sheet.
  4. 　前記３種類以上の熱伝導性粒子が、平均粒子径３μｍ未満の第１熱伝導性粒子、平均粒子径３μｍ以上７０μｍ未満の第２熱伝導性粒子、および、平均粒子径７０μｍ以上の第３熱伝導性粒子を含有することを特徴とする、請求項１に記載の熱伝導性粒子。 The three or more kinds of thermally conductive particles are a first thermally conductive particle having an average particle diameter of less than 3 μm, a second thermally conductive particle having an average particle diameter of 3 μm or more and less than 70 μm, and a third heat having an average particle diameter of 70 μm or more. The thermally conductive particles according to claim 1, comprising conductive particles.
  5. 　前記３種類以上の熱伝導性粒子が、平均粒子径３μｍ未満の第１熱伝導性粒子、平均粒子径３μｍ以上７０μｍ未満の第２熱伝導性粒子、および、平均粒子径３μｍ以上７０μｍ未満で鱗片状である第４熱伝導性粒子を含有することを特徴とする、請求項１に記載の熱伝導性粒子。 The three or more types of thermally conductive particles are a first thermally conductive particle having an average particle diameter of less than 3 μm, a second thermally conductive particle having an average particle diameter of 3 μm or more and less than 70 μm, and a scale particle having an average particle diameter of 3 μm or more and less than 70 μm. The thermally conductive particles according to claim 1, wherein the thermally conductive particles contain a fourth thermally conductive particle that is in the shape of a tube.
  6. 　前記アクリル系粘着剤層は、（メタ）アクリル酸アルキルエステルを主成分とし、極性基含有モノマーを５質量％以上含有するモノマー成分を重合することにより得られるアクリル系ポリマーを含有することを特徴とする、請求項１に記載の熱伝導性粘着シート。 The acrylic pressure-sensitive adhesive layer contains an acrylic polymer obtained by polymerizing a monomer component containing (meth) acrylic acid alkyl ester as a main component and containing 5% by mass or more of a polar group-containing monomer. The thermally conductive adhesive sheet according to claim 1.
  7. 　前記モノマー成分は、カルボキシル基を有するモノマーを実質的に含まないことを特徴とする、請求項６に記載の熱伝導性粘着シート。 The heat conductive pressure-sensitive adhesive sheet according to claim 6, wherein the monomer component does not substantially contain a monomer having a carboxyl group.
  8. 　前記極性基含有モノマーは、窒素含有モノマーおよび／または水酸基含有モノマーを含有することを特徴とする、請求項６に記載の熱伝導性粘着シート。 The heat conductive adhesive sheet according to claim 6, wherein the polar group-containing monomer contains a nitrogen-containing monomer and / or a hydroxyl group-containing monomer.
  9. 　前記熱伝導性粘着シートの硬度が、タイプＣ硬さ試験において、タイプＣデュロメータの加圧面を密着させてから３０秒後に測定したときに、８０以下であることを特徴とする、請求項１に記載の熱伝導性粘着シート。 The hardness of the thermally conductive pressure-sensitive adhesive sheet is 80 or less when measured 30 seconds after the pressure surface of a type C durometer is brought into close contact in a type C hardness test. The heat conductive adhesive sheet of description.
  10. 　前記熱伝導性粘着シートの厚み方向における熱伝導率が、１．７Ｗ／ｍ・Ｋ以上であることを特徴とする、請求項１に記載の熱伝導性粘着シート。 The heat conductive adhesive sheet according to claim 1, wherein the heat conductivity in the thickness direction of the heat conductive adhesive sheet is 1.7 W / m · K or more.
  11. 　前記熱伝導性粘着シートは、ＵＬ９４難燃性試験において、Ｖ－０規格を満たすことを特徴とする、請求項１に記載の熱伝導性粘着シート。 The heat conductive pressure-sensitive adhesive sheet according to claim 1, wherein the heat conductive pressure-sensitive adhesive sheet satisfies a V-0 standard in a UL94 flame retardant test.
  12. 　アクリル系粘着剤層を備える熱伝導性粘着シートの製造する方法であって、
    （メタ）アクリル酸アルキルエステルを主成分とするモノマー成分に、平均粒子径が異なる３種以上である熱伝導性粒子を混合して、粘着剤原料を得る工程、および
    　前記粘着剤原料を反応させ、前記アクリル系粘着剤層を得る工程
    　を備え、
    　前記３種以上の熱伝導性粒子を混合したときの空間率が、７２％以下であり、　
    　前記アクリル系粘着剤層に対する前記３種以上の熱伝導性粒子の含有割合が、５５体積％以上７５体積％以下であることを特徴する、熱伝導性粘着シートの製造方法。     A method for producing a thermally conductive pressure-sensitive adhesive sheet comprising an acrylic pressure-sensitive adhesive layer,
    A step of obtaining a pressure-sensitive adhesive raw material by mixing three or more kinds of thermally conductive particles having different average particle diameters with a monomer component mainly composed of (meth) acrylic acid alkyl ester, and reacting the pressure-sensitive adhesive raw material The step of obtaining the acrylic pressure-sensitive adhesive layer,
    The space ratio when mixing the three or more kinds of heat conductive particles is 72% or less,
    The manufacturing method of the heat conductive adhesive sheet characterized by the content rate of the said 3 or more types of heat conductive particle with respect to the said acrylic adhesive layer being 55 volume% or more and 75 volume% or less.
PCT/JP2013/077273 2012-10-30 2013-10-07 Thermally conductive adhesive sheet and method for producing same WO2014069178A1 (en)

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CN104755574A (en) 2015-07-01
JP2014088506A (en) 2014-05-15

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