CN104212368A - Heat conductive adhesive sheet - Google Patents

Abstract

The invention provides an adhesive sheet with excellent flame retardation performance, heat conductivity, and adhesiveness. The heat-conductive adhesive sheet comprises an adhesive layer, the thickness of the adhesive layer is below 50 [mu]m, in the adhesive layer, a particle group A with the D50 average particle diameter of above 10 [mu]m and a particle group B with the D50 average particle diameter of below 10 [mu]m serve as heat conductive particles and cooperate with each other with the proportion of the ratio (weight ratio) of 2:8-8:2 of the particle group A to the particle group B. The content of the heat conductive particles in the adhesive layer is preferred to be above 25 size% and below 75 size%. Besides, the heat conductive adhesive sheet prefers VTM-0 or V-0 flame retardation performance in the flame retardation test of the UL94 standard.

Description

Thermal conductivity adhesive sheet

Technical field

The present invention relates to thermal conductivity adhesive sheet.More specifically relate to the thermal conductivity adhesive sheet that the thickness of binder layer is little.

Background technology

In recent years, mobile equipment, household electrical appliances etc. are miniaturization gradually, and the adhesive sheet used when being fixed by the member of formation of its inside etc. also requires further slimming.Owing to having heat because of device interior accumulation and worry on fire, therefore, these adhesive sheets require to have excellent flame retardant resistance (nonflammable character).

In the past, as the adhesive sheet with flame retardant resistance, known to the adhesive sheet (patent documentation 1) of fire retardant of halogen system, the adhesive sheet (patent documentation 2 ~ 4) of the fire retardant containing phosphoric acid system.But the fire retardant of halogen system has problems in environmental safety, and when the fire retardant of phosphoric acid system has, electric/electronic device comes in contact the problems such as fault.Therefore, the fire retardant used beyond halogen system, phosphoric acid system is being studied.

Prior art document

Patent documentation

Patent documentation 1: Japanese Unexamined Patent Publication 2002-173657 publication

Patent documentation 2: Japanese Unexamined Patent Publication 11-1669 publication

Patent documentation 3: Japanese Unexamined Patent Publication 11-323268 publication

Patent documentation 4: Japanese Unexamined Patent Publication 11-189753 publication

Summary of the invention

The problem that invention will solve

In order to use the fire retardant beyond halogen system, phosphoric acid system to obtain sufficient flame retardant resistance, need the use level increasing fire retardant within the adhesive layer.But if increase the use level of fire retardant, then sometimes producing thickness cannot the problem such as homogeneous, adhesive layer surface roughen, binding property reduction.That is, current situation is, uses halogen system, fire retardant beyond phosphoric acid system, has excellent flame retardant resistance and the also excellent thin tackiness agent of thermal conductivity and binding property also belongs to unknown.

Therefore, the object of the present invention is to provide and a kind ofly there is excellent flame retardant resistance and the little adhesive sheet of the thickness of the also excellent binder layer of thermal conductivity and binding property.

For the means of dealing with problems

The present inventor has carried out research extensively and profoundly to reach above-mentioned purpose, found that containing 2 kinds there is specific median size within the adhesive layer particle as thermal conductivity particle time, even if the adhesive sheet that binder layer is thin, flame retardant resistance, thermal conductivity and binding property are still excellent can be obtained, and completes the present invention.

Namely the invention provides a kind of thermal conductivity adhesive sheet, it has binder layer, and the thickness of this binder layer is less than 50 μm, in described binder layer, the particle group B that the particle group A of D50 median size more than 10 μm and D50 median size are less than 10 μm is coordinated with the ratio that described particle group A and the ratio (weight ratio) of particle group B are 2:8 ~ 8:2 as thermal conductivity particle.

The content of the thermal conductivity particle in described binder layer is preferably 25 more than volume % and 75 below volume %.

Described thermal conductivity adhesive sheet preferably has the flame retardant resistance of VTM-0 or V-0 in the flame retardant test of UL94 standard.

The thermal conductivity of described thermal conductivity adhesive sheet is preferably more than 0.3W/mK.

The confining force (80 DEG C, 300gf) of described thermal conductivity adhesive sheet is preferably below 2mm.

Described binder layer is preferably active energy ray curable binder layer.

Invention effect

Thermal conductivity adhesive sheet of the present invention has above-mentioned formation, even if therefore binder layer is thin, thermal conductivity and flame retardant resistance are also excellent, and binding property is also excellent.

Accompanying drawing explanation

Fig. 1 is the schematic diagram representing thermal property evaluating apparatus.

Embodiment

Thermal conductivity adhesive sheet of the present invention has binder layer (being sometimes called " binder layer X " by this binder layer), and the thickness of this binder layer is less than 50 μm, in described binder layer, the particle group B that the particle group A of D50 median size more than 10 μm and D50 median size are less than 10 μm is coordinated with the ratio that described particle group A and the ratio (weight ratio) of particle group B are 2:8 ~ 8:2 as thermal conductivity particle.

Thermal conductivity adhesive sheet of the present invention can for have at the one side of base material binder layer the one side adhesive sheet with base material, base material two-sided have binder layer the double-sided adhesive sheet with base material, do not have base material without any one in base material adhesive sheet (without base material double-sided adhesive sheet).Wherein, from the view point of selecting the various material that will be fixed, be preferably double-sided adhesive sheet, particularly from the aspect of thickness thinning that can make adhesive sheet, preferably without base material double-sided adhesive sheet.Binder layer can be individual layer also can be multilayer.It should be noted that, the release liner (partition) peeled off during above-mentioned " base material " use not included in thermal conductivity adhesive sheet.In addition, when double-sided adhesive sheet with base material, as long as at least one binder layer is described specific binder layer X.

In this specification sheets, " adhesive sheet " also comprises " self adhesive tape ".In addition, in this specification sheets, sometimes the composition (coating liquid etc.) used when forming binder layer is called " binder composition ".

[binder layer]

The binder layer of described thermal conductivity adhesive sheet can give play to cementability.Such binder layer is formed by binder composition.Such as acrylic adhesive layer described later is formed by acrylic adhesive composition.

As the tackiness agent forming above-mentioned binder layer, be not particularly limited, but such as carbamate system tackiness agent, acrylic adhesive, elastomeric adhesive, silicone-based adhesive, Polyester tackiness agent, polyamide-based tackiness agent, epoxy adhesive, vinyl alkyl ethers system tackiness agent, fluorine system tackiness agent etc. can be enumerated.Wherein, from the view point of the tackiness agent design easness of weathering resistance, thermotolerance, function, foundation cost or application target, preferred acrylic adhesive.That is, thermal conductivity adhesive sheet of the present invention preferably has acrylic adhesive layer.

Aforesaid propylene acid is that binder layer contains polymkeric substance based on acrylic acid polymer.Aforesaid propylene acid based polymer is as the polymkeric substance forming monomer component containing acrylic monomer (having the monomer of (methyl) acryl in molecule).Aforesaid propylene acid based polymer is preferably containing (methyl) alkyl acrylate as the polymkeric substance forming monomer component.It should be noted that, acrylic acid polymer can be used alone or two or more combinationally uses.

As above-mentioned (methyl) alkyl acrylate, be not particularly limited, but such as can enumerate (methyl) methyl acrylate, (methyl) ethyl propenoate, (methyl) propyl acrylate, (methyl) isopropyl acrylate, (methyl) butyl acrylate, (methyl) isobutyl acrylate, (methyl) sec-butyl acrylate, (methyl) tert-butyl acrylate, (methyl) amyl acrylate, (methyl) isoamyl acrylate, (methyl) Ethyl acrylate, (methyl) heptylacrylate, (methyl) Octyl acrylate, (methyl) 2-EHA, (methyl) Isooctyl acrylate monomer, (methyl) vinylformic acid ester in the ninth of the ten Heavenly Stems, (methyl) vinylformic acid ester in the different ninth of the ten Heavenly Stems, (methyl) decyl acrylate, (methyl) isodecyl acrylate, (methyl) vinylformic acid undecyl ester, (methyl) dodecylacrylate, (methyl) tridecyl acrylate, (methyl) vinylformic acid tetradecyl ester, (methyl) vinylformic acid pentadecyl ester, (methyl) aliphatic acrylate, (methyl) vinylformic acid heptadecyl ester, (methyl) octadecyl acrylate, (methyl) vinylformic acid nonadecyl ester, (methyl) vinylformic acid eicosyl ester etc. has (methyl) alkyl acrylate that carbonatoms is the alkyl of 1 ~ 20.Wherein, from the view point of the balance easily obtaining adhesion characteristic, preferably there is (methyl) alkyl acrylate that carbonatoms is the alkyl of 1 ~ 12 (particularly 2 ~ 12), be more preferably and there is (methyl) alkyl acrylate that carbonatoms is the alkyl of 4 ~ 9.Above-mentioned (methyl) alkyl acrylate may be used singly or in combin two or more.

Above-mentioned (methyl) alkyl acrylate is not particularly limited relative to the ratio of the whole monomer components (100 % by weight) forming aforesaid propylene acid based polymer, but be preferably more than 60 % by weight (such as 60 ~ 99 % by weight), be more preferably more than 70 % by weight (such as 70 ~ 98 % by weight), more preferably more than 80 % by weight (such as 80 ~ 98 % by weight).

Aforesaid propylene acid based polymer can be only containing above-mentioned (methyl) alkyl acrylate as forming its polymkeric substance of monomer component, but from the aspect of the function can given as required, more suitably control the aspect such as the various characteristic of tackiness agent or the structure of acrylic acid polymer, also can be simultaneously containing above-mentioned (methyl) alkyl acrylate and co-polymerized monomer as forming its polymkeric substance of monomer component.It should be noted that, co-polymerized monomer may be used singly or in combin two or more.

As above-mentioned co-polymerized monomer, can enumerate containing polar group monomer.As above-mentioned containing polar group monomer, be not particularly limited, but such as can enumerate: carboxyl group-containing monomer, hydroxyl monomer, nitrogen containing monomer, containing sulfonic group monomer, phosphorous acid-based monomers etc.It should be noted that, may be used singly or in combin two or more containing polar group monomer.

Above-mentioned carboxyl group-containing monomer is the monomer in 1 molecule with more than 1 carboxyl, can be the form of acid anhydrides.As above-mentioned carboxyl group-containing monomer, be not particularly limited, but such as can enumerate: (methyl) vinylformic acid, methylene-succinic acid, toxilic acid, fumaric acid, β-crotonic acid, iso-crotonic acid, maleic anhydride, itaconic anhydride etc.It should be noted that, carboxyl group-containing monomer may be used singly or in combin two or more.

Especially, aforesaid propylene acid based polymer preferably in fact containing carboxyl group-containing monomer as forming its monomer component.In addition, " do not contain in fact " carboxyl group-containing monomer to refer to, form completely not containing carboxyl group-containing monomer in the monomer component of acrylic acid polymer, or carboxyl group-containing monomer is less than 0.1 % by weight relative to the ratio of the whole monomer components (100 % by weight) forming acrylic acid polymer.

When aforesaid propylene acid be binder layer contain thermal conductivity particle described later, if aforesaid propylene acid based polymer contains carboxyl group-containing monomer as forming its monomer component, then be difficult to because of thermal conductivity particle sometimes obtain the effect containing improving containing the cementability caused by polar group monomer, in addition, the mobility of the composition and acrylic adhesive composition that sometimes form acrylic adhesive layer reduces and is difficult to form binder layer.Although their reason is also very not clear and definite, but infer that its reason is: functional group's (such as hydroxyl etc.) that the carboxyl of carboxyl group-containing monomer and thermal conductivity particle have reacts, make acrylic adhesive composition harder or make binder layer harder than required than required, the wettability of binder layer reduces.

If containing hydroxyl monomer as co-polymerized monomer, then thermal conductivity dispersion of particles becomes good, and in addition, acrylic adhesive layer easily obtains the good wettability to adherend.As above-mentioned hydroxyl monomer, such as, can enumerate: (methyl) vinylformic acid 2-hydroxy methacrylate, (methyl) vinylformic acid 2-hydroxy propyl ester, (methyl) vinylformic acid 3-hydroxy propyl ester, (methyl) vinylformic acid 4-hydroxybutyl, the own ester of (methyl) vinylformic acid 6-hydroxyl, (methyl) vinylformic acid 8-hydroxyl monooctyl ester, (methyl) vinylformic acid 10-hydroxyl ester in the last of the ten Heavenly stems, (methyl) vinylformic acid 12-hydroxylauric ester, methacrylic acid (4-Hydroxymethyl-cyclo-hexyl) methyl esters etc.Wherein, preferred (methyl) vinylformic acid 2-hydroxy methacrylate, (methyl) vinylformic acid 3-hydroxy propyl ester, (methyl) vinylformic acid 4-hydroxybutyl.It should be noted that, hydroxyl monomer may be used singly or in combin two or more.

If containing nitrogen containing monomer as co-polymerized monomer, then give the polarity of appropriateness, acrylic adhesive layer easily obtains the good adhesion properties of the cementability, bonding reliability etc. at stickup initial stage.As above-mentioned nitrogen containing monomer, such as, can enumerate: N-hydroxyalkyl (methyl) acrylamides such as N-(2-hydroxyethyl) (methyl) acrylamide, N-(2-hydroxypropyl) (methyl) acrylamide, N-(1-hydroxypropyl) (methyl) acrylamide, N-(3-hydroxypropyl) (methyl) acrylamide, N-(2-hydroxybutyl) (methyl) acrylamide, N-(3-hydroxybutyl) (methyl) acrylamide, N-(4-hydroxybutyl) (methyl) acrylamide; Ring-type (methyl) acrylamides such as N-(methyl) acryloyl morpholine, N-acryl tetramethyleneimine; (methyl) acrylamide, N-replace non-annularity (methyl) acrylamides such as (methyl) acrylamide.Replace (methyl) acrylamide as above-mentioned N-, can enumerate: N-alkyl (methyl) acrylamides such as N-ethyl (methyl) acrylamide, N-normal-butyl (methyl) acrylamide; N, N-dimethyl (methyl) acrylamide, N, N-diethyl (methyl) acrylamide, N, N-dipropyl (methyl) acrylamide, N, N-di-isopropyl (methyl) acrylamide, N, N, N-dialkyl group (methyl) acrylamides etc. such as N-bis-(normal-butyl) (methyl) acrylamide, N, N-bis-(tertiary butyl) (methyl) acrylamide.

Further, as above-mentioned nitrogen containing monomer, such as can enumerate: NVP (NVP), N-vinyl-2-piperidone, N-vinyl-3-morpholone mai, N-vinyl-2-hexanolactam, N-vinyl-1, the N-vinyl cyclic acid amides such as 3-oxazine-2-ketone, N-vinyl-3,5-morpholine diketone; (methyl) acrylate, (methyl) vinylformic acid N, N-dimethylamino ethyl ester, (methyl) vinylformic acid N, N-dimethylamino propyl ester etc. has amino monomer; N-N-cyclohexylmaleimide, N-phenylmaleimide etc. have the monomer of maleimide skeleton; The clothing health imide series monomers etc. such as N-methyl clothing health imide, N-ethyl clothing health imide, N-butyl clothing health imide, N-2-ethylhexyl clothing health imide, N-lauryl clothing health imide, N-cyclohexyl clothing health imide.It should be noted that, nitrogen containing monomer may be used singly or in combin two or more.

Wherein, as above-mentioned nitrogen containing monomer; preferred N-hydroxyalkyl (methyl) acrylamide, N-vinyl cyclic acid amides, ring-type (methyl) acrylamide, N-replace (methyl) acrylamide; more preferably N-(2-hydroxyethyl) (methyl) acrylamide, NVP, N-(methyl) acryloyl morpholine, N, N-diethyl (methyl) acrylamide.

Above-mentioned nitrogen containing monomer is not particularly limited relative to the ratio of the whole monomer components (100 % by weight) forming aforesaid propylene acid based polymer, but its lower limit is preferably more than 1 % by weight, is more preferably more than 2 % by weight.In addition, its upper limit is preferably less than 10 % by weight, is more preferably less than 7 % by weight.

As above-mentioned containing sulfonic group monomer, such as, can enumerate: styrene sulfonic acid, allyl sulphonic acid, 2-(methyl) acrylamide-2-methyl propane sulfonic, (methyl) acrylamide propane sulfonic acid, (methyl) vinylformic acid sulphur propyl ester, (methyl) acryl oxygen base naphthene sulfonic acid etc.It should be noted that, may be used singly or in combin two or more containing sulfonic group monomer.

As above-mentioned phosphorous acid-based monomers, such as, can enumerate 2-hydroxyethyl acryloyl phosphate etc.It should be noted that, phosphorous acid-based monomers may be used singly or in combin two or more.

Form the above-mentioned mixing ratio containing polar group monomer in the monomer component of aforesaid propylene acid based polymer to be not particularly limited, but be such as preferably more than 0.1 % by weight relative to the monomer component total amount (100 % by weight) forming aforesaid propylene acid based polymer, be more preferably more than 0.5 % by weight, more preferably more than 1 % by weight, more preferably more than 2 % by weight, more preferably more than 3 % by weight, be particularly preferably more than 5 % by weight.In addition, the above-mentioned mixing ratio containing polar group monomer is not particularly limited, but be such as preferably less than 40 % by weight relative to the monomer component total amount (100 % by weight) forming aforesaid propylene acid based polymer, be more preferably less than 30 % by weight, more preferably less than 25 % by weight, be particularly preferably less than 20 % by weight.The above-mentioned mixing ratio containing polar group monomer in above-mentioned monomer component is not particularly limited, but is such as preferably 0.1 ~ 40 % by weight relative to the monomer component total amount (100 % by weight) forming aforesaid propylene acid based polymer.If above-mentioned mixing ratio is in above-mentioned scope, then the cohesive force of binder layer becomes appropriateness, can obtain high confining force and bounding force.

In addition, as above-mentioned co-polymerized monomer, the monomer with alkoxyl group can be enumerated.If containing there is the monomer of alkoxyl group as co-polymerized monomer, then the wettability of acrylic adhesive layer can be improved, the heat from adherend (the generation source of heat) effectively can be conducted.As the above-mentioned monomer with alkoxyl group, such as, can enumerate: (methyl) vinylformic acid 2-methoxy acrylate, (methyl) vinylformic acid 3-methoxyl group propyl ester, (methyl) methoxyethyl glycol ester, (methyl) methoxyethyl polypropylene glycol ester etc.It should be noted that, the monomer with alkoxyl group may be used singly or in combin two or more.

The above-mentioned monomer with alkoxyl group is not particularly limited relative to the ratio of the whole monomer components (100 % by weight) forming aforesaid propylene acid based polymer, and its lower limit is preferably 3 % by weight, is more preferably 5 % by weight.In addition, its upper limit is preferably 20 % by weight, is more preferably 15 % by weight.

Further, as above-mentioned co-polymerized monomer, polyfunctional monomer can be enumerated.By above-mentioned polyfunctional monomer, crosslinking structure can be introduced in acrylic acid polymer, the cohesive force of binder layer can be adjusted.As above-mentioned polyfunctional monomer, such as can enumerate: hexylene glycol two (methyl) acrylate, butyleneglycol two (methyl) acrylate, (gathering) ethylene glycol bisthioglycolate (methyl) acrylate, (gathering) propylene glycol two (methyl) acrylate, neopentyl glycol two (methyl) acrylate, tetramethylolmethane two (methyl) acrylate, tetramethylolmethane three (methyl) acrylate, Dipentaerythritol six (methyl) acrylate, trimethylolpropane tris (methyl) acrylate, tetramethylol methane three (methyl) acrylate, (methyl) allyl acrylate, (methyl) vinyl acrylate, Vinylstyrene, epoxy acrylate, polyester acrylate, urethane acrylate etc.It should be noted that, above-mentioned polyfunctional monomer may be used singly or in combin two or more.

Above-mentioned polyfunctional monomer is not particularly limited relative to the ratio of the whole monomer components (100 % by weight) forming aforesaid propylene acid based polymer, but its lower limit is preferably 0.01 % by weight, is more preferably 0.02 % by weight.In addition, its upper limit is preferably 2 % by weight, is more preferably 1 % by weight.If the ratio of polyfunctional monomer is more than 0.01 % by weight, then obtain high cohesive force, easily obtain high confining force, thus preferably.On the other hand, if the ratio of polyfunctional monomer is less than 2 % by weight, then can suppress the generation of the unfavorable condition that cohesive force is too high, cementability reduces, therefore preferably.

In addition, as above-mentioned co-polymerized monomer, also can enumerate: (methyl) glycidyl acrylate, allyl glycidyl ether etc. has the monomer of epoxy group(ing); Vinyl cyanide, methacrylonitrile etc. have the monomer of cyano group; The styrenic monomers such as vinylbenzene, alpha-methyl styrene; The alpha-olefins such as ethene, propylene, isoprene, divinyl, iso-butylene; Vinylformic acid-2-isocyanato ethyl, methacrylic acid-2-isocyanato ethyl etc. have the monomer of isocyanate group; The vinyl ester such as vinyl-acetic ester, propionate system monomer; The vinyl ether system monomers such as vinyl ether; (methyl) tetrahydrofurfuryl acrylate etc. has (methyl) acrylate of heterocycle; Fluorine-containing (methyl) acrylate etc. has the monomer of halogen atom; 3-methacryloxypropyl trimethoxy silane, vinyltrimethoxy silane etc. have the monomer of alkoxysilyl; Silicone (methyl) acrylate etc. has the monomer of siloxane bond; (methyl) vinylformic acid ring pentyl ester, (methyl) cyclohexyl acrylate, (methyl) vinylformic acid norbornene ester, (methyl) isobornyl acrylate etc. have (methyl) acrylate of ester ring type alkyl; (methyl) phenyl acrylate, (methyl) benzyl acrylate, (methyl) acrylate, (methyl) vinylformic acid phenoxy group binaryglycol ester etc. have (methyl) acrylate etc. of aromatic hydrocarbyl.

The second-order transition temperature (Tg) of aforesaid propylene acid based polymer is not particularly limited, but set out in the aspect of the acrylic adhesive layer of the low elasticity that is easy to get calmly, the aspect easily obtaining the good acrylic adhesive layer of difference of altitude absorptivity, its upper limit is preferably-10 DEG C, be more preferably-20 DEG C, and its lower limit is preferably-70 DEG C, is more preferably-65 DEG C.The Tg of acrylic acid polymer can by selecting the composition of the monomer component forming it, use level adjusts.At this, the Tg of acrylic acid polymer refers to, the value that the Tg of homopolymer based on each monomer forming monomer component is obtained by Fox formula with the weight percent (copolymerization composition) of this monomer.The value of the Tg of homopolymer can be obtained by various known data (Nikkan Kogyo Shimbun " adhering technique handbook (Nian Ji Intraoperative Ha Application De Block ッ Network) " etc.).

Aforesaid propylene acid based polymer can by making above-mentioned polymerizing monomer components to obtain.As polymerization process, be not particularly limited, but such as can enumerate solution polymerization, letex polymerization, mass polymerization, photopolymerization (active energy beam polymerization) etc.Wherein, the preferred polymerization process utilizing heat, active energy beam (such as the ionization such as alpha-ray, β ray, gamma-rays, neutron ray, electron beam property radioactive rays or ultraviolet etc.), more preferably employs the utilization heat of the polymerization starter such as thermal polymerization, Photoepolymerizationinitiater initiater, the polymerization process of active energy beam.It should be noted that, polymerization starter may be used singly or in combin two or more.

Especially, as above-mentioned polymerization process, even if from the view point of can shorten polymerization time viewpoint and when making the thin binder layer containing thermal conductivity particle this electrical conductivity particle also disperse equably, easily can produce the homogeneous and binder layer of surface smoothing of thickness, preferably employ the polymerization process utilizing active energy beam (particularly ultraviolet) of Photoepolymerizationinitiater initiater.That is, as binder layer X, active energy ray curable binder layer is preferably.When using solution polymerization process etc., when making the thin binder layer containing thermal conductivity particle, electrical conductivity particle is difficult to disperse equably sometimes, and the surface of binder layer becomes coarse.

As above-mentioned Photoepolymerizationinitiater initiater, be not particularly limited, but such as can enumerate: benzoin ether system Photoepolymerizationinitiater initiater, methyl phenyl ketone system Photoepolymerizationinitiater initiater, α-one alcohol system Photoepolymerizationinitiater initiater, aromatic sulfonyl system Photoepolymerizationinitiater initiater, photolytic activity oxime system Photoepolymerizationinitiater initiater, bitter almond oil camphor system Photoepolymerizationinitiater initiater, benzil system Photoepolymerizationinitiater initiater, benzophenone series Photoepolymerizationinitiater initiater, ketal system Photoepolymerizationinitiater initiater, thioxanthone system Photoepolymerizationinitiater initiater etc.It should be noted that, Photoepolymerizationinitiater initiater may be used singly or in combin two or more.

As above-mentioned benzoin ether system Photoepolymerizationinitiater initiater, such as can enumerate: benzoin methyl ether, benzoin ethyl ether, bitter almond oil camphor propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-ketone, phenylmethylether methyl ether etc.As above-mentioned methyl phenyl ketone system Photoepolymerizationinitiater initiater, such as can enumerate: 2,2-diethoxy acetophenone, 2,2-dimethoxy-2-phenyl acetophenone, 1-hydroxycyclohexylphenylketone, 4-phenoxydichloroacetophenone, 4-(tertiary butyl) dichloroacetophenone etc.As above-mentioned α-one alcohol system Photoepolymerizationinitiater initiater, such as, can enumerate: 2-methyl-2-hydroxypropiophenonepreparation, 1-[4-(2-hydroxyethyl) phenyl]-2-methylpropane-1-ketone etc.As above-mentioned aromatic sulfonyl system Photoepolymerizationinitiater initiater, such as, can enumerate 2-naphthalic sulfonic chloride etc.As above-mentioned photolytic activity oxime system Photoepolymerizationinitiater initiater, such as, can enumerate: 1-phenyl-1,1-propanedione-2-(o-ethoxy carbonyl) oxime etc.As above-mentioned bitter almond oil camphor system Photoepolymerizationinitiater initiater, such as, bitter almond oil camphor etc. can be enumerated.As above-mentioned benzil system Photoepolymerizationinitiater initiater, such as, can enumerate: benzil etc.As above-mentioned benzophenone series Photoepolymerizationinitiater initiater, such as, can enumerate: benzophenone, benzoyl phenylformic acid, 3,3 '-dimethyl-4-methoxy benzophenone, polyvinyl benzophenone, Alpha-hydroxy cyclohexyl-phenyl ketone etc.As above-mentioned ketal system Photoepolymerizationinitiater initiater, such as, can enumerate: dibenzoyl methyl ketal etc.As above-mentioned thioxanthone system Photoepolymerizationinitiater initiater, such as, can enumerate: thioxanthone, CTX, 2-methyl thioxanthone, 2,4-dimethyl thioxanthone, isopropyl thioxanthone, 2,4-diisopropylthioxanthone, decyl thioxanthone etc.

The usage quantity of above-mentioned Photoepolymerizationinitiater initiater is not particularly limited, but relative to forming monomer component 100 weight part of aforesaid propylene acid based polymer, its lower limit is preferably 0.01 weight part, is more preferably 0.05 weight part.In addition, its upper limit is preferably 5 weight parts, is more preferably 3 weight parts.

When photopolymerization, the irradiation energy, irradiation time etc. of active energy beam (especially ultraviolet) are not particularly limited.As long as Photoepolymerizationinitiater initiater can be made to activate, the reaction of monomer component occurs.

As above-mentioned thermal polymerization, can 2 be enumerated, 2 '-Diisopropyl azodicarboxylate, 2, 2 '-azo two-2-methylbutyronitrile, 2, two (2 Methylpropionic acid) dimethyl ester of 2 '-azo, 4, 4 '-azo two-4-cyanopentanoic acid, 2,2'-Azobis(2,4-dimethylvaleronitrile), 2, two (2-amidine propane) dihydrochloride of 2 '-azo, 2, two [2-(5-methyl-2-tetrahydroglyoxaline-2-base) propane] dihydrochloride of 2 '-azo, 2, two (the 2-methyl-prop amidine) dithionate of 2 '-azo, 2, two (the N of 2 '-azo, N '-dimethyleneisobutylamidine) hydrochloride, 2, the azo system polymerization starters such as two [N-(2-the carboxy ethyl)-2-methyl-prop amidine] hydrates of 2 '-azo, the peroxidation system polymerization starter such as dibenzoyl peroxide, the peroxidation toxilic acid tert-butyl ester (t-Block チ Le ペ Le マ レ エ ー ト), tertbutyl peroxide, hydrogen peroxide, the persulphate such as Potassium Persulphate, ammonium persulphate, the reducto oxydative system polymerization starters etc. such as the combination of the combination of persulphate and sodium bisulfite, superoxide and sodium ascorbate.It should be noted that, thermal polymerization may be used singly or in combin two or more.

The usage quantity of thermal polymerization is not particularly limited, such as, can select in the scope that in the past can utilize as polymerization starter.When utilizing heat to be polymerized, such as monomer component and thermal polymerization are dissolved in suitable solvent (such as the organic solvent such as toluene, ethyl acetate), such as make it react at 20 ~ 100 DEG C (preferably 40 ~ 80 DEG C), can acrylic acid polymer be obtained thus.

[thermal conductivity particle]

Thermal conductivity adhesive sheet of the present invention containing thermal conductivity particle, therefore can obtain good thermal conductivity, and adhesive sheet can be made nonflammable, flame can be made to be difficult to spread in adhesive sheet within the adhesive layer.Excellent thermal conductivity and flame retardant resistance can be obtained.Thermal conductivity particle can be used alone or two or more combinationally uses.

As above-mentioned thermal conductivity particle, such as, can enumerate metal hydroxides, hydrated metal compound (water and metallic compound) etc.The kick off temperature of above-mentioned hydrated metal compound the scope of 150 ~ 500 DEG C, and is formula M _m1o _n1xH ₂o (at this, M is metal, m1, n1 be by the valence of metal determine more than 1 integer, X represents containing the number of crystal water) shown in compound or comprise the double salt of this compound.

As above-mentioned metal hydroxides and above-mentioned hydrated metal compound, be not particularly limited, but such as can enumerate: aluminium hydroxide [Al ₂o ₃3H ₂o; Or Al (OH) ₃], boehmite [Al ₂o ₃h ₂o; Or AlOOH], magnesium hydroxide [MgOH ₂o; Or Mg (OH) ₂], calcium hydroxide [CaOH ₂o; Or Ca (OH) ₂], zinc hydroxide [Zn (OH) ₂], silicic acid [H ₄siO ₄; Or H ₂siO ₃; Or H ₂si ₂o ₅], ironic hydroxide [Fe ₂o ₃h ₂o or 2FeO (OH)], copper hydroxide [Cu (OH) ₂], hydrated barta [BaOH ₂o; Or BaO9H ₂o], Zirconium oxide hydrate [ZrOnH ₂o], tin oxide hydrate [SnOH ₂o], alkaline magnesium carbonate [3MgCO ₃mg (OH) ₂3H ₂o], hydrotalcite [6MgOAl ₂o ₃h ₂o], dawsonite [Na ₂cO ₃al ₂o ₃nH ₂o], borax [Na ₂oB ₂o ₅5H ₂o], zinc borate [2ZnO3B ₂o ₅3.5H ₂o] etc.Wherein, from the view point of obtaining excellent flame retardant resistance, preferred aluminium hydroxide, magnesium hydroxide.Above-mentioned hydrated metal compound and above-mentioned metal hydroxides can individually use or combinationally use two or more.

Above-mentioned hydrated metal compound, metal hydroxides can use commercially available product.As the commercially available product of aluminium hydroxide, such as can enumerate trade(brand)name " HIGILITE H-31 " (median size 18 μm) (Showa electrician Inc.), trade(brand)name " HIGILITE H-32 " (median size 8 μm) (Showa electrician Inc.), trade(brand)name " HIGILITE H-42 " (median size 1 μm) (Showa electrician Inc.), trade(brand)name " HIGILITE H-43M " (median size 0.8 μm) (Showa electrician Inc.), trade(brand)name " B103ST " (median size 8 μm) (Japanese light metal Inc.) etc.In addition, as the commercially available product of magnesium hydroxide, such as, can enumerate trade(brand)name " KISUMA5A " (median size 1 μm) (consonance chemical industrial company system), trade(brand)name " ECOMAG Z-10 " (median size 1.4 μm, Tateho (タ テ ホ) chemical industrial company's system) etc.

Further, as above-mentioned thermal conductivity particle, such as, can enumerate: the metal nitrides such as boron nitride, aluminium nitride, silicon nitride, gan; The metal oxides such as the stannic oxide of aluminium sesquioxide (aluminum oxide), magnesium oxide, titanium oxide, zinc oxide, stannic oxide, cupric oxide, nickel oxide, doping metaantimmonic acid.In addition, also can enumerate: silicon carbide, silicon-dioxide, calcium carbonate, barium titanate, potassium titanate, copper, silver, gold, nickel, aluminium, platinum, carbon black, carbon pipe (carbon nanotube), carbon fiber, diamond etc.

This type of thermal conductivity particle can use general commercially available product.As the commercially available product of boron nitride, such as, can enumerate: trade(brand)name " HP-40 " (Shui Dao alloy iron Inc.), trade(brand)name " PT620 " (MOMENTIVE Inc.) etc.As the commercially available product of aluminum oxide, such as, can enumerate: trade(brand)name " AS-50 " (Showa electrician Inc.), trade(brand)name " AL-13KT " (median size 96 μm) (Showa electrician Inc.) etc.As the commercially available product of the stannic oxide of doping metaantimmonic acid, such as, can enumerate: trade(brand)name " SN-100S " (stone originates in industry company and manufactures), trade(brand)name " SN-100P " (stone originates in industry company and manufactures), trade(brand)name " SN-100D (water-dispersion product) " (stone originates in industry company and manufactures) etc.As the commercially available product of titanium oxide, such as, can enumerate: trade(brand)name " TTO series " (stone originates in industry company and manufactures) etc.As the commercially available product of zinc oxide, trade(brand)name " SnO-310 " (manufacture of Osaka, Sumitomo cement company), trade(brand)name " SnO-350 " (manufacture of Osaka, Sumitomo cement company), trade(brand)name " SnO-410 " (manufacture of Osaka, Sumitomo cement company) etc. can be enumerated.

Wherein, as above-mentioned thermal conductivity particle, from thermal conductivity, flame retardant resistance, cost aspect, be preferably metal hydroxides, hydrated metal compound, metal oxide, be more preferably aluminium hydroxide, aluminum oxide, magnesium hydroxide, magnesium oxide.That is, above-mentioned thermal conductivity particle is preferably selected from least a kind of particle in metal hydroxides, hydrated metal compound and metal oxide, is more preferably at least a kind of particle be selected from aluminium hydroxide, aluminum oxide, magnesium hydroxide and magnesium oxide.As above-mentioned thermal conductivity particle, particularly preferably aluminium hydroxide.

The shape of above-mentioned thermal conductivity particle is not particularly limited, and can be bulk, needle-like, tabular, stratiform.Bulk comprises such as spherical, rectangular-shaped, broken shape or their profiled shape.

Thermal conductivity adhesive sheet of the present invention is in above-mentioned binder layer X, and the particle group B that the particle group A of D50 median size more than 10 μm and D50 median size are less than 10 μm is coordinated with the ratio that described particle group A and the ratio (weight ratio) of particle group B are 2:8 ~ 8:2 as thermal conductivity particle.The particle group B that the particle group A of D50 median size more than 10 μm and D50 median size are less than 10 μm is coordinated with specific ratio, even if therefore the thickness of binder layer is thin (even if being less than 50 μm), also binding property excellence can be obtained and the homogeneous and binder layer of surface smoothing of thickness (screening characteristics is excellent).On the other hand, when only using the particle group A of D50 median size more than 10 μm, if the thickness of binder layer is thin, be then difficult to obtain the homogeneous and binder layer of surface smoothing (screening characteristics is poor) of thickness.In addition, when only using D50 median size to be less than the particle group B of 10 μm, if the thickness of binder layer is thin, be then difficult to obtain high adhesion.

It should be noted that, median size is that what to utilize the particle size distribution method in laser scattering method to obtain take volume as the value of benchmark.Specifically, obtain by using the measurement of laser scattering type size-grade distribution to determine D50 value.

The D50 median size of the particle group A of D50 median size more than 10 μm is such as 10 ~ 100 μm, and its lower limit is preferably 12 μm, is more preferably 15 μm.In addition, its upper limit is preferably 50 μm, is more preferably 30 μm, more preferably 25 μm.

The D50 median size that D50 median size is less than the particle group B of 10 μm is such as more than 0.1 μm and is less than 10 μm, and its lower limit is preferably 0.3 μm, is more preferably 0.5 μm.In addition, its upper limit is preferably 8 μm, is more preferably 5 μm, more preferably 3 μm.

Described particle group A is preferably 3:7 ~ 7:3 with the ratio (weight ratio) of particle group B.

Described particle group A in above-mentioned binder layer X and the total content of particle group B are not particularly limited, but are preferably 25 more than volume % and 75 below volume % relative to the cumulative volume (100 volume %) of binder layer X.Its lower limit is more preferably 30 volume %.In addition, its upper limit is more preferably 70 volume %, more preferably 60 volume %.If above-mentioned thermal conductivity particle is 25 more than volume % containing proportional (total content of particle group A and particle group B), be then easy to obtain good thermal conductivity, good flame retardant resistance, therefore preferably.In addition, if above-mentioned thermal conductivity particle is 75 below volume % containing proportional (total content of particle group A and particle group B), then pliability can be suppressed to decline, and the decline of bounding force or confining force can be suppressed, therefore preferably.It should be noted that, the unit " volume % " used in above-mentioned total content (containing proportional) can be scaled unit " % by weight " by using the density of thermal conductivity particle.

[dispersion agent]

In the scope not damaging effect of the present invention, stably disperseing to make above-mentioned thermal conductivity particle that cohesion not occur, in above-mentioned binder layer X, can also dispersion agent be contained.

As above-mentioned dispersion agent, be not particularly limited, but such as preferably can use phosphoric acid ester.As phosphoric acid ester, there is the phosphodiester, phosphotriester, or derivatives thereof etc. of the phosphate monoester of polyoxyethylene (or polyoxyethylene base) ether or polyoxyethylene aryl ethers, polyoxyethylene ether or polyoxyethylene aryl ethers.Wherein, phosphate monoester, the phosphodiester of polyoxyethylene ether or polyoxyethylene aryl ethers is preferably used.Above-mentioned dispersion agent can be used alone or two or more combinationally uses.

The content of above-mentioned dispersion agent is not particularly limited, but is such as preferably 0.01 ~ 10 weight part relative to base polymer (such as, as aforesaid propylene acid based polymer during acrylic adhesive layer) 100 weight parts in above-mentioned binder layer X.Its lower limit is more preferably 0.05 weight part, more preferably 0.1 weight part.In addition, its upper limit is more preferably 5 weight parts, more preferably 3 weight parts.

Above-mentioned dispersion agent can use general commercially available product, such as, trade(brand)name " Plysurf (プ ラ イ サ ー Off) A212E " (the first industrial pharmaceutical Inc.), trade(brand)name " Plysurf A210G " (the first industrial pharmaceutical Inc.), trade(brand)name " Plysurf A212C " (the first industrial pharmaceutical Inc.), trade(brand)name " Plysurf A210F " (the first industrial pharmaceutical Inc.), trade(brand)name " Phosphanol (Off ォ ス Off ァ ノ ー Le) RE610 " (Dong Bang chemical company system), trade(brand)name " Phosphanol RS710 " (Dong Bang chemical company system), trade(brand)name " Phosphanol RS610 " (Dong Bang chemical company system) etc.

[fluorine system tensio-active agent]

Fluorine system tensio-active agent can also be contained in above-mentioned binder layer X.By using above-mentioned fluorine system tensio-active agent, the adaptation of base polymer and electrical conductivity particle, friction resistance reduce sometimes, and stress dispersion improves.Therefore, in thermal conductivity adhesive sheet of the present invention, sometimes higher binding property can be obtained.

As above-mentioned fluorine system tensio-active agent, be not particularly limited, such as, in preferred molecule there is oxygen C _2-3the fluorine system tensio-active agent of alkylidene group and fluoro alkyl.Wherein, from the viewpoint of the dispersiveness relative to base polymers such as acrylic acid polymer, above-mentioned fluorine system tensio-active agent is preferably in molecule has C _2-3the nonionic surface active agent of the fluorine system of alkylidene group and fluoro alkyl.It should be noted that, above-mentioned fluorine system tensio-active agent can be used alone or combinationally use two or more.

As above-mentioned fluoro alkyl, be not particularly limited, but such as preferred perfluoroalkyl.Above-mentioned perfluoroalkyl can be that 1 valency also can for multivalence more than divalent.In addition, above-mentioned fluoro alkyl can also contain double bond, triple bond, can be linear chain structure, also can have branched structure, ring structures.The carbonatoms of above-mentioned fluoro alkyl is not particularly limited, but is such as preferably more than 1 or 2, is more preferably 3 ~ 30, more preferably 4 ~ 20.When there is fluoro alkyl, when above-mentioned binder layer X comprises bubble, also can obtain the effect improving bubble Combination and bubble stability.1 kind of above-mentioned fluoro alkyl can be imported in above-mentioned fluorine system surfactant molecule, also can import two or more.

Above-mentioned oxygen C _2-3alkylidene group formula :-R-O-(R is the straight-chain of carbonatoms 2 or 3 or the alkylidene group of branched) represents.Above-mentioned oxygen C _2-3alkylidene group is not particularly limited, but such as can enumerate: oxygen ethylidene (-CH ₂cH ₂o-), oxygen propylidene [-CH ₂cH (CH ₃) O-] etc.Above-mentioned oxygen C _2-3alkylidene group can for the Sauerstoffatom of end being bonded with the alcohol of hydrogen atom, the Sauerstoffatom of end and the ether of other alkyl bonding, the Sauerstoffatom of end by any form such as ester of carbonyl and other alkyl bonding.In addition, can also be ring type ethers, lactone etc. have this structure form in a part for ring texture.1 kind of above-mentioned oxygen C can be imported in above-mentioned fluorine system surfactant molecule _{2 -3}alkylidene group, also can import two or more.

Above-mentioned fluorine system tensio-active agent is not particularly limited, but such as can enumerate: will comprise and have oxygen C _2-3the monomer of alkylidene group and there is the polymerizing monomer components of monomer of fluoro alkyl and the multipolymer obtained.When above-mentioned fluorine system tensio-active agent is multipolymer, such as, can be segmented copolymer, graft copolymer etc.

As above-mentioned segmented copolymer, (main chain has oxygen C _2-3the multipolymer of alkylidene group and fluoro alkyl), be not particularly limited, but such as can enumerate: polyoxyethylene perfluoroalkyl ethers, polyoxyethylene perfluoroalkyl compound, polyoxypropylene perfluoroalkyl ethers, polyoxy isopropylidene perfluoroalkyl ethers, polyoxy ethylene sorbitol alcohol acid anhydride perfluoroalkyl compound, polyoxyethylene polyoxypropylene block multipolymer perfluoroalkyl compound, polyoxyethylene glycol perfluoroalkyl compound etc.

As above-mentioned graft copolymer, (side chain has oxygen C _2-3the multipolymer of alkylidene group and fluoro alkyl), be not particularly limited, such as can enumerate: comprise the vinyl compound with polyoxy alkylidene to major general and there is the polymerizing monomer components of vinyl compound of fluoro alkyl and the multipolymer that obtains, particularly preferably acrylic copolymer.As the above-mentioned vinyl compound with polyoxy alkylidene, such as, can enumerate: polyoxy alkylidene (methyl) acrylate such as polyoxyethylene (methyl) acrylate, polyoxypropylene (methyl) acrylate, polyoxyethylene polyoxypropylene (methyl) acrylate.As the above-mentioned vinyl compound with fluoro alkyl, such as, can enumerate: (methyl) acrylate containing hydrofluoric ether such as (methyl) perfluoroalkyl acrylate such as (methyl) perfluoroethyl butyl ester, (methyl) perfluoroethyl isobutyl ester, (methyl) perfluoroethyl pentyl ester.

Above-mentioned fluorine system tensio-active agent deoxygenation C _2-3beyond alkylidene group and fluoro alkyl, in the scope not hindering the dispersiveness in acrylic acid polymer, the various functional groups such as ester ring type alkyl, aromatic hydrocarbyl, carboxyl, sulfonic group, cyano group, amide group, amino can also be had in the molecule.Such as, when above-mentioned fluorine system tensio-active agent is vinyl based copolymer, as monomer component, can use can with there is the vinyl compound of polyoxy alkylidene and there is the monomer component of vinyl compound copolymerization of fluoro alkyl.The monomer of energy copolymerization like this can be used alone or combinationally use two or more.

As the monomer component of above-mentioned energy copolymerization, such as, be suitable for using (methyl) vinylformic acid C such as (methyl) vinylformic acid undecyl ester, (methyl) dodecylacrylate _1-20alkyl ester; (methyl) vinylformic acid ring pentyl ester etc. has (methyl) acrylate of ester ring type alkyl; (methyl) phenyl acrylate etc. has (methyl) acrylate of aromatic hydrocarbyl.In addition, also can enumerate: the carboxyl group-containing monomer such as toxilic acid, β-crotonic acid; Sodium vinyl sulfonates etc. are containing sulfonic group monomer; The aromatic ethenyl compound such as vinylbenzene, Vinyl toluene; The alkene such as ethene, divinyl or dienes; The vinyl ethers such as vinyl alkyl ethers; The amide-containing monomers such as acrylamide; The emulsion stabilities such as (methyl) acryloyl morpholine; (methyl) vinylformic acid methylglycidyl esters etc. are containing glycidyl monomer; 2-methacryloxyethyl isocyanic ester etc. are containing isocyanate group monomer; Multi-functional co-polymerized monomer such as Dipentaerythritol six (methyl) acrylate, Vinylstyrene etc. (polyfunctional monomer) etc.

The weight-average molecular weight of above-mentioned fluorine system tensio-active agent is not particularly limited, but such as less than 20000 time (be such as more than 500 and less than 20000), reduce the adaptation between base polymer and above-mentioned thermal conductivity particle such as aforesaid propylene acid based polymer, friction resistance effect high.In addition, and during fluorine system tensio-active agent by weight-average molecular weight more than 20000 (such as 20000 ~ 100000, preferably 22000 ~ 80000, more preferably 24000 ~ 60000), at above-mentioned binder layer containing in alveolate situation, the Combination of bubble, the stability of bubble be mixed with uprise.

As the usage quantity (solids component) of fluorine system tensio-active agent, be not particularly limited, but such as relative to whole monomer components 100 weight part (base polymer 100 weight part) for the formation of base polymers such as aforesaid propylene acid based polymers, be preferably 0.01 ~ 5 weight part.Its lower limit is preferably 0.02 weight part, more preferably 0.03 weight part.In addition, its upper limit is preferably 3 weight parts, more preferably 2 weight parts.If above-mentioned usage quantity is more than 0.01 weight part, then, under above-mentioned binder layer contains alveolate situation, the stability of bubble can be obtained, if below 5 weight parts, then can obtain good bond properties.

From with than the less content of situation being used alone above-mentioned dispersion agent, above-mentioned fluorine system tensio-active agent, make above-mentioned metal hydroxides and/or above-mentioned hydrated metal compound do not occur cohesion and stably exist thus the stress dispersion of binder layer improve and can expect that higher fusible viewpoint is set out, can be used together above-mentioned dispersion agent and above-mentioned fluorine system tensio-active agent in above-mentioned binder layer X.When and with above-mentioned dispersion agent and above-mentioned fluorine system tensio-active agent, its mixing ratio is not particularly limited, but above-mentioned dispersion agent is preferably 1:20 ~ 20:0.01 with the ratio (weight ratio) of above-mentioned fluorine system tensio-active agent, is more preferably 1:10 ~ 10:0.01, more preferably 1:5 ~ 5:0.01.

As having oxygen C _2-3alkylidene group and fluoro alkyl, and weight-average molecular weight is less than the concrete example of the fluorine system tensio-active agent of 20000, trade(brand)name " フ タ ー ジ ェ Application ト 251 " (Co., Ltd. Neos system) can be enumerated, trade(brand)name " FTX-218 " (Co., Ltd. Neos system), trade(brand)name " Megafac (メ ガ Off ァ ッ Network) F-477 " (DIC Inc.), trade(brand)name " Megafac F-470 " (DIC Inc.), trade(brand)name " Surflon (サ ー Off ロ Application) S-381 " (AGCSeimichemical Inc.), trade(brand)name " Surflon S-383 " (AGC Seimichemical Inc.), trade(brand)name " Surflon S-393 " (AGC Seimichemical Inc.), trade(brand)name " Surflon KH-20 " (AGC Seimichemical Inc.), trade(brand)name " Surflon KH-40 " (AGC Seimichemical Inc.) etc.As having oxygen C _2-3alkylidene group and fluoro alkyl and weight-average molecular weight are the concrete example of the fluorine system tensio-active agent of more than 20000, can enumerate trade(brand)name " Eftop (エ Off ト ッ プ) EF-352 " (Mitsubishi Materials electronics changes into Inc.), trade(brand)name " Eftop EF-801 " (Mitsubishi Materials electronics changes into Inc.), trade(brand)name " Unidyne (ユ ニ ダ イ Application) TG-656 " (Daikin Industries Inc.) etc.

[linking agent]

From the viewpoint of the cohesive force that can regulate binder layer, in above-mentioned binder layer X, linking agent can also be contained.Above-mentioned linking agent can use known usual linking agent, such as, can enumerate: epoxy linking agent, isocyanate-based linking agent, silicone-based linking agent, oxazoline system linking agent, aziridine system linking agent, silane system linking agent, alkyl etherified melamine system linking agent, metal complex system linking agent etc.Wherein, preferred isocyanate system linking agent, epoxy linking agent.

As above-mentioned isocyanate-based linking agent, such as, can enumerate: the adducts etc. of tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, eylylene diisocyanate, hydrogenation eylylene diisocyanate, diphenylmethanediisocyanate, hydrogenated diphenyl methane diisocyanate, tetramethyl xylylen vulcabond, naphthalene diisocyanate, triphenylmethane triisocyanate, polymethylene polyphenyl isocyanate and these polyvalent alcohols such as isocyanic ester and TriMethylolPropane(TMP).In addition, the compound of isocyanate group and more than 1 unsaturated link(age) with more than at least 1 can also be used in 1 molecule, specifically for (methyl) vinylformic acid 2-isocyanato ethyl etc.

As above-mentioned epoxy linking agent, such as can enumerate: the epoxy system resin of dihydroxyphenyl propane, Epicholorohydrin type, ethylidene glycidyl ether, polyethylene glycol diglycidyl base ether, glycerine diglycidyl ether, glycerine triglycidyl group ether, 1,6-hexylene glycol glycidyl ether, trimethylolpropane tris glycidyl ether, diglycidylaniline, diamines glycidyl group amine, N, N, N ', N '-four glycidyl group m-xylene diamine and 1,3-pair (N, N '-diamines glycidyl-amino methyl) hexanaphthene etc.

The content of above-mentioned linking agent is not particularly limited, but such as relative to base polymer 100 weight parts such as the aforesaid propylene acid based polymers in above-mentioned binder layer X, is preferably 0.01 ~ 5 weight part.Its upper limit is more preferably 3 weight parts, more preferably 2 weight parts.Good flexibility can be obtained, by for more than 0.01 weight part high coherency can be obtained by making above-mentioned content be below 5 weight parts.

[tackifying resin]

Improve further from the viewpoint of binding property, in above-mentioned binder layer X, can also tackifying resin be contained.Particularly, time in the monomer component forming the base polymers such as aforesaid propylene acid based polymer not containing carboxyl group-containing monomer, if the thickness of binder layer is thin, be then difficult to obtain high adhesion, therefore preferably containing tackifying resin.As above-mentioned tackifying resin, be not particularly limited, even if but also consider by the reason also not easily causing polymerization to hinder when obtaining acrylic acid polymer from making monomer component copolymerization by irradiation ultraviolet radiation, the preferred tackifying resin using hydrogenation type.As the tackifying resin of hydrogenation type, such as, can enumerate and hydrogenation be carried out to tackifying resins such as rosin series resin, petroleum line resin, terpenic series resin, coumarone indene system resin, phenylethylene resin series, alkyl phenolic resin, xylene resins and the derivative (hydrogenation type rosin series resin, hydrogenation type petroleum line resin, hydrogenation type terpenic series resin etc.) obtained.Wherein, preferred hydrogenation type rosin series resin.As above-mentioned hydrogenation type rosin series tackifying resin, such as, can enumerate the modified rosin etc. being made unmodified rosin (undressed rosin) modifications such as gum resin, wood rosin, starex by hydrogenation.

The softening temperature of above-mentioned tackifying resin is not particularly limited, but is such as preferably 80 ~ 200 DEG C, is more preferably 90 ~ 200 DEG C.By making the softening temperature of tackifying resin within the scope of this, thus cohesive force improves further.

The content of above-mentioned tackifying resin is not particularly limited, but relative to base polymer 100 weight parts such as the aforesaid propylene acid based polymers in above-mentioned binder layer, is preferably 1 ~ 50 weight part.Its lower limit is more preferably 2 weight parts, more preferably 3 weight parts.In addition, its upper limit is more preferably 40 weight parts, more preferably 30 weight parts.By making above-mentioned content be below 50 weight parts, high cohesive force can be obtained thus, and by for more than 1 weight part, high bounding force can be obtained thus.

Above-mentioned tackifying resin can use general commercially available product, can use such as trade(brand)name " Super ester (ス ー パ ー エ ス テ Le) A-100 " the hydrogenation type rosin series resin such as (softening temperature 95 ~ 105 DEG C, Huang Chuan chemical industrial company system), trade(brand)name " Super ester A-125 " (softening temperature 120 ~ 130 DEG C, Huang Chuan chemical industrial company system).

[acrylic oligomers]

Improve further from the viewpoint of binding property, above-mentioned binder layer X can also contain acrylic oligomers.Aforesaid propylene acid to be oligopolymer be second-order transition temperature (Tg) is higher, weight-average molecular weight is less compared with aforesaid propylene acid based polymer polymkeric substance, it has and to work as tackifying resin and not easily to occur when employing ultraviolet polymerization to be polymerized the advantage hindered.

[silane coupling agent]

From the viewpoint of the affinity improving the base polymers such as bounding force, the viewpoint of resisting power, the further above-mentioned thermal conductivity particle of raising and aforesaid propylene acid based polymer further, in above-mentioned binder layer X, silane coupling agent can also be contained.

As above-mentioned silane coupling agent, can be suitable for using known silane coupling agent, such as can enumerate 3-glycidoxypropyltrime,hoxysilane, 3-glycidoxypropyl group triethoxyl silane, 3-glycidoxypropyl diethoxy silane, 2-(3,4-epoxycyclohexyl) ethyl trimethoxy silane etc. containing epoxy silane coupling; 3-TSL 8330, N-2-(amino-ethyl)-3-amino propyl methyl dimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl butyrate fork base) propylamine etc. are containing amino silicane coupling agent; 3-acryloxypropyl Trimethoxy silane, 3-methacryloxypropyl etc. are containing (methyl) acrylic (ア Network リ Le base) silane coupling agent; 3-isocyanatopropyl triethoxyl silanes etc. are containing isocyanato silanes coupling agent etc.Above-mentioned silane coupling agent can be used alone, and also can be mixed with two or more.

The content of above-mentioned silane coupling agent is not particularly limited, and such as, relative to base polymer 100 weight parts such as the aforesaid propylene acid based polymers in above-mentioned binder layer X, is preferably 0.01 ~ 10 weight part.Its lower limit is more preferably 0.02 weight part, more preferably 0.05 weight part.In addition, its upper limit is more preferably 5 weight parts, more preferably 2 weight parts.By using above-mentioned silane coupling agent in above-mentioned scope, thus cohesive force, weather resistance improve further.

[bubble]

Above-mentioned binder layer X can for the binder layer containing bubble.Above-mentionedly can give thickness and resiliency to binder layer containing alveolate binder layer, concavo-convex performance, the i.e. concavo-convex absorptivity (concavo-convex tracing ability) on landfill adherend surface improve.

[other additive]

Except base polymer, above-mentioned thermal conductivity particle, above-mentioned dispersion agent, above-mentioned fluorine system tensio-active agent, above-mentioned linking agent, above-mentioned tackifying resin, the aforesaid propylene acid such as aforesaid propylene acid based polymer are except oligopolymer, above-mentioned silane coupling agent in above-mentioned binder layer X, other additive can also be contained according to purposes.As other additive above-mentioned, such as, can enumerate softening agent, weighting agent, anti-aging agent, tinting material (pigment, dyestuff etc.) etc.

The thickness of above-mentioned binder layer X is less than 50 μm (such as 1 ~ 50 μm), as lower limit, is preferably 5 μm, more preferably 10 μm, is particularly preferably 20 μm.By making above-mentioned thickness be less than 50 μm, binder layer becomes soft, can obtain excellent resistance to rebound resilience.In addition, when adhesive sheet is processed as different shape, after carrying out stamping-out to binder layer, stamping-out position not easily occurs bonding (adhesion) again, thus excellent in workability.In addition, the decline making thinner caused bounding force is few, and therefore binding property is excellent.If above-mentioned thickness is more than 1 μm, then screening characteristics is excellent.With regard to adhesive sheet of the present invention, the thickness due to above-mentioned binder layer is in above-mentioned scope, and the problems such as thin-walled spot (か The れ) therefore not easily occur after coating.

Above-mentioned binder layer X can be formed by binder composition aforesaid propylene acid base polymer, the above-mentioned thermal conductivity particle such as based polymer and the above-mentioned dispersion agent etc. that adds as required mixed.Specifically, such as, by the monomer component for the formation of base polymers such as aforesaid propylene acid based polymers, above-mentioned polymerization starter (such as Photoepolymerizationinitiater initiater, thermal polymerization etc.), suitable solvent (toluene, ethyl acetate etc.) etc. mixing, prepare monomer solution, this monomer solution is carried out to the polyreaction of the kind corresponding to polymerization starter, preparation comprises the polymers soln of the base polymers such as the acrylic acid polymer of monomer component copolymerization, then in this polymers soln, above-mentioned thermal conductivity particle is coordinated, above-mentioned dispersion agent etc. as required, preparation has the binder composition being suitable for the viscosity applied.In addition, when being cured by ultraviolet isoreactivity energy-ray, also can by the monomer component for the formation of base polymers such as acrylic acid polymer, the mixing such as Photoepolymerizationinitiater initiater, prepare monomer mixture, this monomer mixture is carried out to the irradiation of ultraviolet isoreactivity energy-ray, the composition (slurries) of the partial polymer that preparation comprises only partial monosomy composition polymerization and obtains, then in these slurries, above-mentioned thermal conductivity particle is coordinated, above-mentioned dispersion agent etc. as required, preparation has the composition being suitable for the viscosity applied, and use said composition to form binder layer X.

As mentioned above, particularly when adopting the method by active energy beam irradiation formation binder layer, even if when making the thin binder layer containing electrical conductivity particle, also easily can produce that this electrical conductivity particle disperses equably, thickness is homogeneous and the binder layer of surface smoothing.

From the viewpoint of screening characteristics excellence, above-mentioned binder composition preferably has the viscosity of appropriateness.As the viscosity of above-mentioned binder composition, be such as preferably 0.5 ~ 50Pas, lower limit is more preferably 1Pas, more preferably 5Pas.In addition, the upper limit is more preferably 40Pas.If above-mentioned viscosity is below 50Pas, then, when forming binder layer X, the coating of binder composition becomes easy.It should be noted that, in this manual, viscosity refers to and uses BH viscometer as viscometer, at rotor: No.5 rotor, rotating speed: 10rpm, mensuration temperature: the viscosity measured under the condition of 30 DEG C.

The viscosity of above-mentioned binder composition such as can wait to regulate by the following method, and described method comprises: the method coordinating the various component of polymer such as acrylic rubber, thickening property additive; By and the method etc. of forming section polymkeric substance partially polymerized for the formation of the monomer component (such as, for the formation of the monomer component etc. such as (methyl) acrylate of acrylic acid polymer) of acrylic acid polymer.

[base material]

As above-mentioned base material, be not particularly limited, such as, can enumerate: the plastic film containing materials such as the acrylic resin such as polyester based resin, polymethylmethacrylate, polycarbonate, triacetyl cellulose, polysulfones, polyarylester, polyimide, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, ethylene-propylene copolymer such as polyethylene terephthalates (PET).Wherein, from the viewpoint of excellent in flame retardance, preferred polyimide film.

The material of above-mentioned plastic film can be a kind, also can combine two or more.

The thickness of above-mentioned base material suitably can be selected according to purposes, such as, be 2 ~ 250 μm.Its lower limit is preferably 8 μm, is more preferably 10 μm.In addition, its upper limit is preferably 150 μm, is more preferably 50 μm, more preferably 30 μm.If above-mentioned thickness is more than 2 μm, then can obtain sufficient bounding force and confining force, flame retardant resistance.By making above-mentioned thickness be less than 250 μm, thus binder layer becomes soft, is easy to the adhesive sheet obtaining resistance to rebound resilience excellence.It should be noted that, above-mentioned base material can have any form of individual layer and multilayer.In addition, can to the suitable embodiment in the surface of above-mentioned base material as known usual surface treatments such as chemical treatment such as the physical treatment such as Corona discharge Treatment, Cement Composite Treated by Plasma, primary coat process.

In the present invention, from the viewpoint of making, the total thickness of adhesive sheet is very thin, preferably do not have base material without base material double-sided adhesive sheet.

[binder layer beyond binder layer X]

When thermal conductivity adhesive sheet is the double-sided adhesive sheet with base material, at least one side is above-mentioned binder layer X, another side can be above-mentioned binder layer X, also can for other binder layers.As other binder layers, only otherwise damaging effect of the present invention is just not particularly limited, the known usual binder layer formed by known tackiness agents such as carbamate system tackiness agent, acrylic adhesive, elastomeric adhesive, silicone-based adhesive, Polyester tackiness agent, polyamide-based tackiness agent, epoxy adhesive, vinyl alkyl ethers system tackiness agent, fluorine system tackiness agents can such as be enumerated.

[release liner]

Till the adhesive layer surface (adhesive face) of thermal conductivity adhesive sheet of the present invention can carry out protecting in time using with release liner.It should be noted that, when thermal conductivity adhesive sheet of the present invention is double-sided adhesive sheet, each adhesive face can be protected respectively with 2 partitions, and the partition that 1 two sides is release surface also can be utilized to protect with the form of tubular wound into a roll.Release liner uses as the protecting materials of binder layer, is stripped when adhesive sheet being pasted on adherend.In addition, release liner also works as the supporter of binder layer.It should be noted that, also can not release liner be set.

As above-mentioned release liner, usual interleaving paper etc. can be utilized, specifically, such as, except there is at least one surface the base material of the lift-off processing layer formed by stripping treatment agent, the low cementability base material formed by fluorine based polymer (such as tetrafluoroethylene, polychlorotrifluoroethylene, fluorinated ethylene propylene, polyvinylidene difluoride (PVDF), tetrafluoraoethylene-hexafluoropropylene copolymer, chlorine vinyl fluoridevinylidine fluoride multipolymer etc.) or the low cementability base material etc. formed by non-polar polymer (such as the ethylene series such as polyethylene, polypropylene resin etc.) can also be used.

As above-mentioned release liner, at least one side that such as can be suitable for being used in release liner base material is formed with the release liner of lift-off processing layer.As such release liner base material, plastics systems base material film (synthetic resin film) such as polyester film (polyethylene terephthalate film etc.), ethylene series resin molding (polyethylene film, polypropylene screen etc.), polychloroethylene film, polyimide film, polyamide membrane (nylon membrane), artificial cortina can be enumerated, stationery (upper matter paper and paper, kraft paper, glassine paper, synthetic paper, face are coated with paper etc.), and by the base material (complex bodys of 2 ~ 3 layers) etc. by their multiple stratifications such as lamination, coextrusion.

As the stripping treatment agent forming above-mentioned lift-off processing layer, be not particularly limited, but such as can use silicone-based stripping treatment agent, fluorine system stripping treatment agent, chain alkyl system stripping treatment agent etc.Stripping treatment agent can be used alone or combinationally uses two or more.It should be noted that, the thickness, formation method etc. of release liner are not particularly limited.

The manufacture method of adhesive sheet of the present invention is different according to composition of above-mentioned binder composition etc., is not particularly limited, can utilizes known formation method, such as, can enumerate the methods such as following (1) ~ (3).

(1) (coating) is coated with on base material or partition by comprising the binder composition being less than the particle group B, above-mentioned dispersion agent as required etc. of 10 μm for the formation of the monomer component of base polymer such as aforesaid propylene acid based polymer etc., the partial polymer of this monomer component, the particle group A of D50 median size more than 10 μm, D50 median size, form composition layer, make said composition layer solidify (such as thermofixation, utilize ultraviolet isoreactivity energy-ray to irradiate the solidification carried out), formation binder layer manufactures the method for adhesive sheet.

(2) the particle group B, the above-mentioned dispersion agent etc. as required that make base polymer (comprising polymers soln etc.) such as aforesaid propylene acid based polymer etc., the particle group A of D50 median size more than 10 μm, D50 median size be less than 10 μm are dissolved equably, to disperse and the binder composition that obtains is coated with (coating) on base material or partition, carry out drying, form binder layer, manufacture the method for adhesive sheet.

(3) adhesive sheet manufactured in above-mentioned (1) is carried out dry method further.

As the curing in above-mentioned (1) ~ (3), even if from the viewpoint of the viewpoint of productivity excellence and also can form the homogeneous and binder layer of surface smoothing of thickness when forming the thin binder layer containing thermal conductivity particle, the method preferably utilizing active energy beam to be cured (particularly utilizing the method that ultraviolet is cured).It should be noted that, the solidification utilizing active energy beam to carry out is subject to the obstruction of the oxygen in air sometimes, therefore, such as, to be cured etc. to block oxygen preferably by partition of fitting over the binder layer, in a nitrogen atmosphere.

It should be noted that, when obtaining containing alveolate binder layer, by by importing bubble (forming the gas of bubble) and the bubbles binder composition be obtained by mixing is coated on the face of regulation in the above-mentioned binder composition containing thermal conductivity particle, thus can be formed containing alveolate binder layer.

As above-mentioned binder composition being coated with (coating) method on the face of regulation, known coating process can be adopted, be not particularly limited, but such as can enumerate: roller coat, roller lick coating, intaglio plate coating, reversion coating, roller brush, spraying, dip roll coating, rod painting, scraper for coating, airblade coating, curtain coating, lip are coated with, utilize the extrusion coating methods etc. of mould painting machine etc.

In order to tackle the miniaturization of mobile equipment, household electrical appliances etc. in recent years, the thickness (total thickness) of thermal conductivity adhesive sheet of the present invention is such as preferably 5 ~ 270 μm.Its lower limit is more preferably 15 μm, more preferably 20 μm.In addition, its upper limit is more preferably 200 μm, more preferably 100 μm, is particularly preferably 50 μm.By making above-mentioned thickness be more than 5 μm, thus easily follow difference of altitude part, difference of altitude absorptivity improves.By making above-mentioned thickness be less than 270 μm, thus resistance to rebound resilience is excellent further.It should be noted that, the thickness (total thickness) of thermal conductivity adhesive sheet is the thickness from an adhesive face to another adhesive face, does not comprise the thickness of release liner.

180 ° of peel adhesion (180 ° of peel adhesion) of the above-mentioned binder layer X of thermal conductivity adhesive sheet of the present invention (23 DEG C, 50%RH, draw speed 300mm/min, peel angle 180 ° stripping conditions, to SUS304 steel plate) be preferably more than 2N/20mm (such as 2 ~ 20N/20mm), be more preferably more than 2.5N/20mm (such as 2.5 ~ 20N/20mm).When thermal conductivity adhesive sheet is double-sided adhesive sheet, preferably 180 ° of peel adhesion of at least one adhesive face meet above-mentioned scope.Above-mentioned 180 ° of peel adhesion such as can be measured by the method recorded in " (2) 180 ° of peel adhesion " of (evaluation) described later.

The thermal conductivity of thermal conductivity adhesive sheet of the present invention is preferably more than 0.3W/mK.Thermal conductivity such as can be measured by the method recorded in " (3) thermal conductivity " of (evaluation) described later.

Thermal conductivity adhesive sheet of the present invention preferably has the flame retardant resistance of VTM-0 or V-0 in the flame retardant test of UL94 standard.Above-mentioned flame retardant resistance such as can be evaluated by the method recorded in " (4) flame retardant resistance " of (evaluation) described later.

The confining force (80 DEG C, 300gf) measured with the face of above-mentioned binder layer X of thermal conductivity adhesive sheet of the present invention is preferably below 2mm, is more preferably below 1mm, more preferably below 0.6mm, is particularly preferably below 0.3mm.In addition, the confining force (80 DEG C, 100gf) measured with the face of above-mentioned binder layer X of thermal conductivity adhesive sheet of the present invention is preferably below 2mm, is more preferably below 1mm, more preferably below 0.3mm, is particularly preferably below 0.2mm.When thermal conductivity adhesive sheet is double-sided adhesive sheet, preferably the confining force of at least one adhesive face meets above-mentioned scope.Above-mentioned confining force such as can be measured by the method recorded in " (5) confining force " of (evaluation) described later.

With regard to thermal conductivity adhesive sheet of the present invention, even if binder layer is thin, its thermal conductivity, flame retardant resistance and binding property are also excellent, use therefore, it is possible to the member of formation (electronics member of formation) being adapted at using in the inside to the electronics such as mobile equipment (such as mobile phone, smart phone, portable information terminal etc.), family's electrical article (such as digital camera, pick up camera, PC etc.), hard disk, LED illumination, lithium ion battery to be fixed etc. in purposes.In recent years, electronics miniaturization densification develops, and when using electronics, the inner thermal change produced must be difficult to be discharged into device external, therefore there is electronic equipment internal Yin Gaore and the worry of burning.Thermal conductivity adhesive sheet of the present invention has excellent thermal conductivity and flame retardant resistance, is therefore suitable for the fixed-purpose that heat is likely to accumulate in the electronics member of formation of the electronic equipment internal of inner small-sized or slim (such as thickness 1 ~ 20mm).

Embodiment

Below, embodiment is enumerated and comparative example carries out more specific description to the present invention.But the present invention is not limited thereto.

(embodiment 1)

Be mixed with 2-EHA 82 weight part, vinylformic acid 2-methoxy acrylate 12 weight part, NVP (NVP) 5 weight part, hydroxyethyl acrylamide (HEAA) 1 weight part is as in the monomer mixture of monomer component, coordinate the trade(brand)name " Irgacure651 " (2 as Photoepolymerizationinitiater initiater, 2-dimethoxy-1, 2-diphenylethane-1-ketone, BASF JAPAN company manufactures) 0.05 weight part and trade(brand)name " Irgacure184 " (1-hydroxycyclohexylphenylketone, BASF JAPAN company manufactures) 0.05 weight part, then irradiation ultraviolet radiation is until viscosity (BH viscometer No.5 rotor, 10rpm, measure temperature 30 DEG C) become about 20Pas, make the mixture (partial polymer of monomer mixture of part polymerizing monomer components, slurries).

Dipentaerythritol acrylate (trade(brand)name " KAYARAD DPHA-40H ", Japanese chemical drug Inc. make) 0.05 weight part as polyfunctional monomer and the trade(brand)name " PLYSURF A212E " as dispersion agent (the first industrial pharmaceutical company manufactures) 1 weight part is added in above-mentioned slurries 100 weight part.In addition, trade(brand)name " HIGILITE H-31 " (shape: broken shape, median size: 18 μm, Showa electrician company manufacture) 100 weight parts of interpolation as aluminium-hydroxide powder and trade(brand)name " HIGILITE H-42 " (shape: broken shape, median size: 1 μm, the manufacture of Showa electrician company) 100 weight parts as aluminium-hydroxide powder, as thermal conductivity particle, obtain composition.

Release liner (the lift-off processing face coating above-mentioned composition of trade(brand)name " DIAFOIL MRF38 " (manufacture of polyester film company of Mitsubishi Chemical) of the polyethylene terephthalate of lift-off processing is implemented at one side, composition layer is set, and becomes the stacked release liner similar to the above of mode of composition layer side with lift-off processing face on said composition layer.

Then, irradiate illumination from the two sides of duplexer and be about 5mW/cm ²ultraviolet 3 minutes, composition layer is solidified, forms the binder layer of thickness 50 μm, obtain the adhesive sheet (without base material adhesive sheet) of the formation with release liner/binder layer/release liner.The thickness (not comprising the thickness of release liner) of adhesive sheet is 50 μm.Thermal conductivity particle in binder layer containing proportional (particle volume ratio) be 42.9 volume %.

It should be noted that, the second-order transition temperature of the acrylic acid polymer contained in binder layer is-62.8 DEG C.In addition, the weight of the acrylic acid polymer contained in binder layer is equivalent to form the monomer of above-mentioned slurries and the total amount of polyfunctional monomer.

(embodiment 2)

Trade(brand)name " HIGILITE H-31 " (shape: broken shape, median size: 18 μm, Showa electrician Inc.) 50 weight parts of interpolation as aluminium-hydroxide powder and trade(brand)name " HIGILITE H-42 " (shape: broken shape, median size: 1 μm, Showa electrician Inc.) 50 weight parts as aluminium-hydroxide powder are as thermal conductivity particle, obtain composition, obtain adhesive sheet (without base material adhesive sheet) in addition similarly to Example 1.The thickness (not comprising the thickness of release liner) of adhesive sheet is 50 μm.Thermal conductivity particle in binder layer containing proportional be 27.3 volume %.

(embodiment 3)

Trade(brand)name " HIGILITE H-31 " (shape: broken shape, median size: 18 μm, Showa electrician Inc.) 50 weight parts of interpolation as aluminium-hydroxide powder and trade(brand)name " HIGILITE H-42 " (shape: broken shape, median size: 1 μm, Showa electrician Inc.) 200 weight parts as aluminium-hydroxide powder are as thermal conductivity particle, obtain composition, obtain adhesive sheet (without base material adhesive sheet) in addition similarly to Example 1.The thickness (not comprising the thickness of release liner) of adhesive sheet is 50 μm.Thermal conductivity particle in binder layer containing proportional be 48.5 volume %.

(embodiment 4)

Trade(brand)name " HIGILITE H-31 " (shape: broken shape, median size: 18 μm, Showa electrician Inc.) 100 weight parts of interpolation as aluminium-hydroxide powder and trade(brand)name " HIGILITE H-42 " (shape: broken shape, median size: 1 μm, Showa electrician Inc.) 150 weight parts as aluminium-hydroxide powder are as thermal conductivity particle, obtain composition, obtain adhesive sheet (without base material adhesive sheet) in addition similarly to Example 1.The thickness (not comprising the thickness of release liner) of adhesive sheet is 50 μm.Thermal conductivity particle in binder layer containing proportional be 48.5 volume %.

(embodiment 5)

Trade(brand)name " HIGILITE H-31 " (shape: broken shape, median size: 18 μm, Showa electrician Inc.) 125 weight parts of interpolation as aluminium-hydroxide powder and trade(brand)name " HIGILITE H-42 " (shape: broken shape, median size: 1 μm, Showa electrician Inc.) 125 weight parts as aluminium-hydroxide powder are as thermal conductivity particle, obtain composition, obtain adhesive sheet (without base material adhesive sheet) in addition similarly to Example 1.The thickness (not comprising the thickness of release liner) of adhesive sheet is 50 μm.Thermal conductivity particle in binder layer containing proportional be 48.5 volume %.

(embodiment 6)

Trade(brand)name " HIGILITE H-31 " (shape: broken shape, median size: 18 μm, Showa electrician Inc.) 150 weight parts of interpolation as aluminium-hydroxide powder and trade(brand)name " HIGILITE H-42 " (shape: broken shape, median size: 1 μm, Showa electrician Inc.) 100 weight parts as aluminium-hydroxide powder are as thermal conductivity particle, obtain composition, obtain adhesive sheet (without base material adhesive sheet) in addition similarly to Example 1.The thickness (not comprising the thickness of release liner) of adhesive sheet is 50 μm.Thermal conductivity particle in binder layer containing proportional be 48.5 volume %.

(embodiment 7)

Trade(brand)name " HIGILITE H-31 " (shape: broken shape, median size: 18 μm, Showa electrician Inc.) 200 weight parts of interpolation as aluminium-hydroxide powder and trade(brand)name " HIGILITE H-42 " (shape: broken shape, median size: 1 μm, Showa electrician Inc.) 50 weight parts as aluminium-hydroxide powder are as thermal conductivity particle, obtain composition, obtain adhesive sheet (without base material adhesive sheet) in addition similarly to Example 1.The thickness (not comprising the thickness of release liner) of adhesive sheet is 50 μm.Thermal conductivity particle in binder layer containing proportional be 48.5 volume %.

(comparative example 1)

Do not use thermal conductivity particle completely, obtain adhesive sheet (without base material adhesive sheet) in addition similarly to Example 1.The thickness (not comprising the thickness of release liner) of adhesive sheet is 50 μm.Thermal conductivity particle in binder layer containing proportional be 0 volume %.

(comparative example 2)

Add as trade(brand)name " HIGILITE H-42 " (shape: broken shape, median size: 1 μm, Showa electrician Inc.) 250 weight parts of aluminium-hydroxide powder as thermal conductivity particle, obtain composition, obtain adhesive sheet (without base material adhesive sheet) in addition similarly to Example 1.The thickness (not comprising the thickness of release liner) of adhesive sheet is 50 μm.Thermal conductivity particle in binder layer containing proportional be 48.5 volume %.

(comparative example 3)

Add as trade(brand)name " HIGILITE H-31 " (shape: broken shape, median size: 18 μm, Showa electrician Inc.) 250 weight parts of aluminium-hydroxide powder as thermal conductivity particle, obtain composition, obtain adhesive sheet (without base material adhesive sheet) in addition similarly to Example 1.The thickness (not comprising the thickness of release liner) of adhesive sheet is 50 μm.Thermal conductivity particle in binder layer containing proportional be 48.5 volume %.

(comparative example 4)

As in 2-EHA 100 weight part of monomer component, coordinate the trade(brand)name " Irgacure651 " (2 as Photoepolymerizationinitiater initiater, 2-dimethoxy-1, 2-diphenylethane-1-ketone, BASF JAPAN company manufactures) 0.05 weight part and trade(brand)name " Irgacure184 " (1-hydroxycyclohexylphenylketone, BASF JAPAN company manufactures) 0.05 weight part, then irradiation ultraviolet radiation is until viscosity (BH viscometer No.5 rotor, 10rpm, measure temperature 30 DEG C) become about 20Pas, make the mixture (partial polymer of monomer mixture of part polymerizing monomer components, slurries).

In above-mentioned slurries 100 weight part, add dipentaerythritol acrylate (trade(brand)name " KAYARAD DPHA-40H ", Japanese chemical drug Inc. make) 0.05 weight part as polyfunctional monomer and the trade(brand)name " PLYSURF A212E " as dispersion agent (the first industrial pharmaceutical company manufactures) 1 weight part.Further, trade(brand)name " HIGILITEH-31 " (shape: broken shape, median size: 18 μm, Showa electrician company manufacture) 125 weight parts of interpolation as aluminium-hydroxide powder and trade(brand)name " HIGILITE H-42 " (shape: broken shape, median size: 1 μm, the manufacture of Showa electrician company) 125 weight parts as aluminium-hydroxide powder, as thermal conductivity particle, obtain composition.

Release liner (the lift-off processing face coating above-mentioned composition of trade(brand)name " DIAFOIL MRF38 " (manufacture of polyester film company of Mitsubishi Chemical) of the polyethylene terephthalate of lift-off processing is implemented at one side, composition layer is set, and on said composition layer, become the stacked release liner similar to the above of mode of composition layer side with lift-off processing face.

Then, irradiate illumination from the two sides of duplexer and be about 5mW/cm ²ultraviolet 3 minutes, composition layer is solidified, forms the binder layer of thickness 50 μm, obtain the adhesive sheet (without base material adhesive sheet) of the formation with release liner/binder layer/release liner.The thickness (not comprising the thickness of release liner) of adhesive sheet is 50 μm.Thermal conductivity particle in binder layer containing proportional (particle volume ratio) be 52 volume %.

It should be noted that, the second-order transition temperature of the acrylic acid polymer contained in binder layer is-30 DEG C.In addition, the weight of the acrylic acid polymer contained in binder layer is equivalent to form the monomer of above-mentioned slurries and the total amount of polyfunctional monomer.

(comparative example 5)

Be mixed with 2-EHA 90 weight part, vinylformic acid 10 weight part is as in the monomer mixture of monomer component, coordinate the trade(brand)name " Irgacure651 " (2 as Photoepolymerizationinitiater initiater, 2-dimethoxy-1, 2-diphenylethane-1-ketone, BASF JAPAN company manufactures) 0.05 weight part, with trade(brand)name " Irgacure184 " (1-hydroxycyclohexylphenylketone, BASFJAPAN company manufactures) 0.05 weight part, then irradiation ultraviolet radiation is until viscosity (BH viscometer No.5 rotor, 10rpm, measure temperature 30 DEG C) become about 20Pas, make the mixture (partial polymer of monomer mixture of part polymerizing monomer components, slurries).

In above-mentioned slurries 100 weight part, add dipentaerythritol acrylate (trade(brand)name " KAYARAD DPHA-40H ", Japanese chemical drug Inc. make) 0.05 weight part as polyfunctional monomer and the trade(brand)name " PLYSURF A212E " as dispersion agent (the first industrial pharmaceutical company manufactures) 1 weight part.Further, trade(brand)name " HIGILITEH-31 " (shape: broken shape, median size: 18 μm, Showa electrician company manufacture) 125 weight parts of interpolation as aluminium-hydroxide powder and trade(brand)name " HIGILITE H-42 " (shape: broken shape, median size: 1 μm, the manufacture of Showa electrician company) 125 weight parts as aluminium-hydroxide powder, as thermal conductivity particle, obtain composition.

Release liner (the lift-off processing face coating above-mentioned composition of trade(brand)name " DIAFOIL MRF38 " (manufacture of polyester film company of Mitsubishi Chemical) of the polyethylene terephthalate of lift-off processing is implemented at one side, composition layer is set, and on said composition layer, become the stacked release liner similar to the above of mode of composition layer side with lift-off processing face.

Then, irradiate illumination from the two sides of duplexer and be about 5mW/cm ²ultraviolet 3 minutes, composition layer is solidified, forms the binder layer of thickness 50 μm, obtain the adhesive sheet (without base material adhesive sheet) of the formation with release liner/binder layer/release liner.The thickness (not comprising the thickness of release liner) of adhesive sheet is 50 μm.Thermal conductivity particle in binder layer containing proportional (particle volume ratio) be 48.5 volume %.

It should be noted that, the second-order transition temperature of the acrylic acid polymer contained in binder layer is 5 DEG C.In addition, the weight of the acrylic acid polymer contained in binder layer is equivalent to form the monomer of above-mentioned slurries and the total amount of polyfunctional monomer.

(evaluation)

Following mensuration or evaluation are carried out to the adhesive sheet obtained in embodiment and comparative example.And the results are shown in table 1.

(1) 50 μm of screening characteristics

The homogeneity of thickness, the surface smoothness of binder layer of the binder layer of the adhesive sheet obtained in visual confirmation the above embodiments and comparative example, be " good (zero) " by homogeneous for the thickness of binder layer and the average evaluation that adhesive layer surface is level and smooth, the uneven thickness one of binder layer or adhesive layer surface seen the average evaluation of thin-walled spot (generation exists the position of binder layer and there is not the position of binder layer) is for " bad (×) ".

(2) 180 ° of peel adhesion

In the adhesive sheet obtained from above-described embodiment and comparative example, the tape sheet of cut-out length 100mm, width 20mm, makes the tape sheet of strip.It should be noted that, the thickness of each tape sheet is the thickness recorded in above-described embodiment and comparative example.

Then, from the tape sheet of above-mentioned strip, release liner is peeled off, by 23 DEG C, make under 50%RH atmosphere 2kg roller come and go 1 time and adhesive face (mensuration face) be crimped on SUS304 steel plate, make working sample.

By said determination sample 23 DEG C, place 30 minutes in the atmosphere of 50%RH after, use tensile testing machine (trade(brand)name " TCM-1kNB ", Minebea company manufacture) to carry out 180 ° of stripping tests, measure the 180 ° of peel adhesion (180 ° of peel adhesion) (N/20mm) to SUS304 steel plate.Be determined at 23 DEG C, under the atmosphere of 50%RH, carry out with the condition of peel angle 180 °, draw speed 300mm/ minute.

(3) thermal conductivity

For the adhesive sheet obtained in the above embodiments and comparative example, the thermal property evaluating apparatus shown in Fig. 1 is used to implement to measure to the thermal conductivity of thickness direction.The front schematic view that (a) of Fig. 1 is thermal property evaluating apparatus, the side schematic view that (b) of Fig. 1 is thermal property evaluating apparatus.It should be noted that, the removing release liner when measuring.

Specifically, a pair block of cubical aluminum (A5052, thermal conductivity: 140W/mK) of a length of side 20mm is being formed as (sometimes also referred to as " barred body ".) sandwich adhesive sheet 1 (wide: 20mm, length: 20mm) between L, a pair block L adhesive sheet 1 is fitted.

Then, the mode of presenting lower placement with a pair block L configures this pair block between heating element (heat block) H and radiator (cooling base formed in the mode of internal recycling with water coolant) C.Specifically, above the block L of upside, configure heating element H, at the below of downside block L configuration radiator C.

Now, with adhesive sheet 1 fit a pair block L between a pair pressure adjusting screw T running through heating element H and radiator C.It should be noted that, be configured with ergometer R between pressure adjusting screw T and heating element H, it is formed in the mode that can measure pressure when screwing pressure adjusting screw T, uses this pressure as the pressure putting on adhesive sheet 1.

Specifically, in this experiment, pressure adjusting screw T is screwed until the pressure putting on adhesive sheet 1 reaches 25N/cm ²(250kPa).

In addition, 3 probes P (diameter 1mm) of contact displacement meter are set in the mode of the block L and adhesive sheet 1 that run through downside from radiator C side.Now, form as follows: the state that the upper end of probe P contacts in the lower surface of the block L with upside, the interval (thickness of adhesive sheet 1) between upper and lower block L can be measured.

Mounting temperature sensor D on heating element H and upper and lower block L.Specifically, at the 1 place mounting temperature sensor D of heating element H, at 5 places of each block L in the vertical direction with 5mm interval mounting temperature sensor D respectively.

Be determined as follows and carry out: first, pressure adjusting screw T is screwed, pressure is applied to adhesive sheet 1, the temperature of heating element H is set in 80 DEG C, and make the water coolant of circulation 20 DEG C in radiator C.

Then, after the temperature-stable of heating element H and upper and lower block L, the temperature of upper and lower block L is measured with each temperature sensor D, calculate the heat flux (Hot a fluid stream) by adhesive sheet 1 by the thermal conductivity (W/mK) of upper and lower block L and thermograde, and calculate the temperature at the interface of upper and lower block L and adhesive sheet 1.Then, use these parameters, utilize following thermal conductivity equation (Fourier's law) to calculate thermal conductivity (W/mK) under this pressure and thermal resistance (cm ²k/W).

Q＝－λgradT

R＝L/λ

Q: the heat flux of per unit area

GradT: thermograde

L: the thickness of sheet

λ: thermal conductivity

R: thermal resistance

(4) flame retardant resistance

Based on flame retardant test standard UL94, carry out following flame retardant test.

By the adhesive sheet obtained in above-described embodiment and comparative example, obtain the test film of 5 length 200mm, width 50mm.It should be noted that, the thickness of each tape sheet is the thickness recorded in above-described embodiment and comparative example.By one end vertical hanging of above-mentioned test film.Then, burner is used to make the other end contact flame 3 seconds, temporarily away from after flame, confirm the state again contacting the test film of flame after 3 seconds, evaluate flame retardant resistance, the average evaluation meeting following benchmark X is " VTM-0 ", will be evaluated as when not meeting benchmark X " poor (×) ".

Benchmark X: following (i) ~ (v) all meets.

I flaming combustion time of () each test film, (contacting the total of the combustion time after initial flame and the combustion time after the flame contacting the 2nd time) was within 10 seconds.

(ii) total ascent time of the flaming combustion time of 5 test films is within 50 seconds.

(iii) the flaming combustion time of each test film after the 2nd contact flame and the total ascent time of glowing time are within 30 seconds.

(iv), in 5 test films, do not make because burning dropping falls from test film the test film that the cotton being configured in below catches fire.

V, in () all test films, unburn is to hanging (hang り under げ) partly (upper end portion).

(5) confining force

Using the adhesive sheet that obtains in the above embodiments and comparative example as assess sample, carry out according to the evaluation of the confining force of JIS Z1528.Use TORAY Inc. " Lumirror (Le ミ ラ ー) S-10#25 " at the one side of adhesive sheet and obtain the sample with lining material.Paste for 1 time to come and go with 2kg roller, with the area making the sample with lining material reach 10mm × 20mm, the self-vulcanizings of 23 DEG C after 30 minutes, the load 1 hour of 100g (or 300g) is applied under the atmosphere of 80 DEG C, confirm to it can be used as the value of confining force (mm) by the displacement that the Self-adhesive initial stage starts.

Nomenclature

1 adhesive sheet

2 thermometers

3 contact displacement meters

C radiator

D temperature sensor

H heating element (heat block)

L block (barred body)

P pops one's head in

R ergometer

T pressure adjusting screw

Claims (6)

1. a thermal conductivity adhesive sheet, it has binder layer, and the thickness of this binder layer is less than 50 μm, in described binder layer, the particle group B that the particle group A of D50 median size more than 10 μm and D50 median size are less than 10 μm is coordinated with the ratio that described particle group A and the ratio of particle group B are 2:8 ~ 8:2 as thermal conductivity particle, and described ratio is weight ratio.

2. thermal conductivity adhesive sheet according to claim 1, wherein, the content of the thermal conductivity particle in described binder layer is 25 more than volume % and 75 below volume %.

3. thermal conductivity adhesive sheet according to claim 1 and 2, it has the flame retardant resistance of VTM-0 or V-0 in the flame retardant test of UL94 standard.

4. the thermal conductivity adhesive sheet according to any one of claims 1 to 3, its thermal conductivity is more than 0.3W/mK.

5. the thermal conductivity adhesive sheet according to any one of Claims 1 to 4, its 80 DEG C, confining force under 300gf is below 2mm.

6. the thermal conductivity adhesive sheet according to any one of Claims 1 to 5, wherein, described binder layer is active energy ray curable binder layer.