CN100537692C - Thermally conductive pressure-sensitive adhesive composition, thermally conductive sheet-form molded foam, and process for producing the same - Google Patents

Abstract

The present invention provides a thermally conductive pressure-sensitive adhesive composition having sufficient pressure-sensitive adhesiveness, excellent particularly in the balance between hardness and pressure-sensitive adhesiveness, having sufficient thermal conductivity, and capable of forming a sheet high in sheet smoothness, wherein the obtained sheet is easy to be removed from the adhesive substance after being used, and to provide a thermally conductive sheet-like molded body comprising the above composition and its manufacturing method. The thermally conductive pressure-sensitive adhesive composition comprises a metal hydroxide and a (meth)acrylic ester copolymer obtained by polymerizing a monomer mixture comprising a (meth)acrylic ester monomer forming a homopolymer having a glass transition temperature of -20 DEG C or lower, a monomer having an organic acid group, and a monomer copolymerizable therewith, in the presence of a copolymer comprising units of a (meth)acrylic ester monomer forming a homopolymer having a glass transition temperature of -20 DEG C or lower, units of a monomer having an organic acid group, units of a monomer having a functional group other than the organic acid group, and units of a monomer copolymerizable therewith, the (meth)acrylic ester copolymer having been foamed.

Description

Thermally conductive pressure-sensitive adhesive composition, thermally conductive sheet-form molded foam and manufacture method thereof

Technical field

The present invention relates to thermally conductive pressure-sensitive adhesive composition, by the manufacture method of its thermally conductive sheet-form molded foam that forms and thermally conductive sheet-form molded foam.

Background technology

In recent years, electronic units such as plasma display (following abbreviating as " PDP "), unicircuit (IC) chip are along with its high performance development, and its thermal value also heightens.As a result, must make up the handicapped countermeasure that the reply temperature raises and brings.Usually take on heat generating members such as electronic unit, to install the method that radiating pieces such as radiator element, heat-dissipating metal sheet, radiator fan make thermodiffusion.In order to make heat generating member to radiating piece heat conduction efficiently, used various thermally-conductive sheet, usually in the purposes of fixedly heat generating member and radiating piece, must the employing pressure sensitive adhesion sheet.

Have thermally conductive pressure-sensitive adhesive composition of the present invention thermally conductive sheet-form molded foam specific embodiments as shown in Figure 1.The electronic unit 100 of Fig. 1 is PDP.PDP has front glass 11, insulator layer 12, protective membrane 13 and back side glass 14, and for example the gap about 0.1mm is superimposed at interval for front glass 11 and back side glass 14, and in addition, this gap is spaced apart 15 and cuts.Be spaced apart in 15 each spaces of cutting (hereinafter referred to as " compartment 18,18,18,---") and fill rare gas such as neon, xenon, by electrode 20,20,20,---apply voltage each other, discharge.The uviolizing that this discharge produced to compartment 18,18,18,--on-inner the fluorescence 19, carry out luminous.On the other hand, the heat that produces owing to this discharge etc. becomes PDP performance reduction etc., therefore heat must be transferred on the radiating piece 17 efficiently, and the radiator element 16 of the sheet-form molded representative of thermal conductivity of the present invention is being undertaken the effect of shifting described heat.Therefore, require that thermal conductivity of the present invention is sheet-form molded to have a high thermal conductivity, simultaneously, for preventing when pasting back side glass 14 grades also to require sheet material smoothness excellence because of sneaking into of bubble etc. reduced this sheet-form molded thermal conductivity.

Disclose a kind of thermal conductivity electrical insulating property pressure sensitive adhesive that contains polymkeric substance and thermal conductivity electrical insulating property particle (thermal conductivity filler) in the patent documentation 1, wherein said polymkeric substance can form with the monomer of the polar monomer of (methyl) alkyl acrylate copolymer by containing.Specifically, be in polyacrylic acid isooctyl acrylate slurry, to add vinylformic acid and linking agents such as aluminum oxide and diacrylate tripropylene glycol ester, obtain pressure sensitive adhesive by photopolymerization.

A kind of thermally conductive pressure-sensitive adhesive that is formed by the photopolymer of following mixture is disclosed in the patent documentation 2, wherein said mixture is a main component with (methyl) alkyl acrylate, and contain monomer mixture, Photoepolymerizationinitiater initiater, as polyfunctional group (methyl) acrylate and the thermal conductivity weighting agent of linking agent, wherein said monomer mixture does not contain the monomer of polar functionalities.

Disclose a kind of thermally conductive pressure-sensitive adhesive in the patent documentation 3, this tackiness agent mixes heat conduction particle and constitutes in the multipolymer of (methyl) alkyl acrylate and the vinyl monomer that satisfies specific formulation.Here employed specific vinyl monomer preferably has (methyl) acrylate or the vinylformic acid 2-hydroxyl-special monomers such as 3-phenoxy group propyl ester of phosphate.

The applicant has proposed a kind of contact adhesive composition, and said composition contains (methyl) acrylic ester polymer (patent documentation 4) of the specific solvent soluble of tool.

Contact adhesive composition with the particular power foaming has been proposed in the patent documentation 5.

In addition, the pressure-sensitive-adhesive radiator element is to have the fixedly binding property or the adhering sheet material of radiating piece and heat generating member, but uses the back at cycling and reutilization or when discarded, needs easily peel off from heat generating member or radiating piece.

As with above-mentioned relevant technology, a kind of method that improves the separability of sheet material is disclosed in the patent documentation 6, this method is to make to contain microcapsule in the sheet material, be surrounded by thermal expansivity materials such as Trimethylmethane or pentane in these microcapsule, after sheet material used, high temperature when being heated to than common use expanded the thermal expansivity material, thereby on the face that sheet material and adherend join, be provided with concavo-convexly, improve the separability of sheet material.

A kind of method that improves separability is also disclosed in the patent documentation 7, this method be with sheet material after use, at high temperature with radioactive rays or action of ultraviolet radiation, make it produce gas, foaming, improve separability thus, wherein said sheet material possesses foam composition and the foaming initiator with tert-butoxycarbonyl structure, and this foaming initiator can produce acid via radioactive rays or UV treatment.

Patent documentation 1: Japanese kokai publication hei 6-088061 communique

Patent documentation 2: Japanese kokai publication hei 10-324853 communique

Patent documentation 3: TOHKEMY 2002-322449 communique

Patent documentation 4: TOHKEMY 2002-285121 communique

Patent documentation 5: TOHKEMY 2002-128931 communique

Patent documentation 6: TOHKEMY 2002-134666 communique

Patent documentation 7: TOHKEMY 2004-043732 communique

Summary of the invention

But disclosed pressure sensitive adhesive is difficult to obtain the balance of hardness and pressure-sensitive-adhesive in patent documentation 1 and the patent documentation 2.In addition, need in the reality to carry out photopolymerization, need equipment, therefore be difficult to favourable economically.

In the method for patent documentation 3 records,, must use special monomer in a large number, therefore be difficult to favourable economically in order to obtain corresponding effects.Be difficult to obtain the equilibrated problem of hardness and pressure-sensitive-adhesive in addition in addition.

The composition of patent documentation 4 record has been eliminated above-mentioned problem, but is difficult to fully keep well the balance of hardness and pressure-sensitive-adhesive, and is also insufficient to the product having shape-following-up properties of irregular heat generating member etc. in addition.

In the composition of patent documentation 5 record, the product having shape-following-up properties of irregular heat generating member etc. is improved, but this sheet material not only needs to contact use with heat generating member, flame retardant resistance also has problem.

The method of patent documentation 6 is the methods that make the such danger of the high material vaporization of burning, explosion hazard, uses the problem of expensive microcapsule in addition in addition.

The method of patent documentation 7 also is the inflammable gas that at high temperature produces burning, explosion potential, at secure context problem is arranged.

Therefore, problem of the present invention is to provide thermally conductive pressure-sensitive adhesive composition, said composition has sufficient pressure-sensitive-adhesive, simultaneously, the balance excellence of hardness and pressure-sensitive-adhesive, have excellent product having shape-following-up properties, flame retardant resistance, thermal conductivity, smoothness in addition, can be made into the sheet material of easy moulding, resulting sheet can be peeled off with adherend safely and easily after use; The present invention also provides thermally conductive sheet-form molded foam and the manufacture method thereof that contains above-mentioned composition.

For solving above-mentioned problem, the inventor has carried out research in depth to said composition is formed, contained to thermally conductive pressure-sensitive adhesive thermally conductive sheet-form molded foam and manufacture method thereof, and the inventor has finished following invention as a result.

A first aspect of the present invention is a thermally conductive pressure-sensitive adhesive composition, it is characterized in that: have the oxyhydroxide (B) of 100 mass parts (methyl) acrylate copolymers (A) and 70-170 mass parts metal, and above-mentioned (methyl) acrylate copolymer (A) foaming; Wherein said (methyl) acrylate copolymer (A) is in the presence of 100 mass parts multipolymers (A1), 5-70 mass parts monomer mixture (A2m) polymerization is obtained, described multipolymer (A1) is to be 100% quality with whole multipolymers (A1), contains the 80-99.9% quality and forms second-order transition temperature (methyl) acrylate monomeric units (a1) for the homopolymer below-20 ℃, the 0.1-20% quality has the monomeric unit (a2) of organic acidic group, the 0-10% quality contains the monomeric unit (a3) of the functional group beyond organic acidic group, and the 0-10% quality can constitute with the monomeric unit (a4) of their copolymerization; Described monomer mixture (A2m) is to be 100% quality with whole monomer mixtures (A2m), contains the 40-100% quality and forms second-order transition temperature and can constitute with the monomer (a7m) of their copolymerization for (methyl) acrylate monomer (a5m) of the homopolymer below-20 ℃, monomer (a6m) that the 60-0% quality has organic acidic group and 0-20% quality.

In the above-mentioned thermally conductive pressure-sensitive adhesive composition, preferred expansion ratio is 1.05-1.4 times.

In the above-mentioned thermally conductive pressure-sensitive adhesive composition, can also contain 0.1-5 mass parts silicon-dioxide (C), the median size of primary granule is 5-20nm in this silicon-dioxide (C), and the hydrophobic rate of being measured by the transmissivity method is below 50%.

In the above-mentioned thermally conductive pressure-sensitive adhesive composition, can also contain 0.05-10 mass parts fusing point is that 120-200 ℃ and molecular weight are lower than 1000 compound (D).

Above-claimed cpd (D) is preferably aliphatic amide compound.

The oxyhydroxide of above-mentioned metal (B) is preferably aluminium hydroxide.

A second aspect of the present invention is the thermally conductive sheet-form molded foam that contains above-mentioned thermally conductive pressure-sensitive adhesive composition.

A third aspect of the present invention is a thermally conductive sheet-form molded foam, the layer of the above-mentioned thermally conductive pressure-sensitive adhesive composition that this mo(u)lded item contains base material, form on the one or both sides of this base material.

A fourth aspect of the present invention is the manufacture method of thermally conductive sheet-form molded foam, this method has following steps: with 100 mass parts multipolymers (A1), 5-70 mass parts monomer mixture (A2m), with respect to 100 mass parts monomer mixtures (A2m) is the thermal polymerization (E2) of 0.1-50 mass parts, mix the step that forms mixture (F) with respect to the multipolymer (A1) that adds up to 100 mass parts for the metal hydroxides (B) of 70-170 mass parts with monomer mixture (A2m), make the step of mixture (F) foaming, the step of heated mixt (F), and mixture (F) made flaky step; Wherein said multipolymer (A1) is to be 100% quality with whole multipolymers (A1), contains the 80-99.9% quality and forms second-order transition temperature the monomeric unit (a3) of organic acidic group functional group in addition and 0-10% quality can constitute with the monomeric unit (a4) of their copolymerization for (methyl) acrylate monomeric units (a1) of the homopolymer below-20 ℃, monomeric unit (a2), 0-10% quality that the 0.1-20% quality has organic acidic group contain; Monomer mixture (A2m) is to be 100% quality with whole monomer mixtures (A2m), contains the 40-100% quality and forms second-order transition temperature and can constitute with the monomer (a7m) of their copolymerization for (methyl) acrylate monomer (a5m) of the homopolymer below-20 ℃, monomeric unit (a6m) that the 0-60% quality has organic acidic group and 0-20% quality.

The above-mentioned step that mixture (F) is foamed is preferably and makes mixture (F) with 1.05 times of-1.4 times of steps that foam of expansion ratio.

In the manufacture method of above-mentioned thermally conductive sheet-form molded foam, said mixture (F) can be with respect to multipolymer (A1) that adds up to 100 mass parts and monomer mixture (A2m), further mixes 0.05-10 mass parts fusing point and is 120-200 ℃ and molecular weight and be lower than the mixture (G) that 1000 compound (D) constitutes.

In the manufacture method of above-mentioned thermally conductive sheet-form molded foam, said mixture (F) can be with respect to multipolymer (A1) that adds up to 100 mass parts and monomer mixture (A2m), further mixes 0.05-10 mass parts fusing point and is 120-200 ℃ and molecular weight and be lower than the mixture that 1000 aliphatic amide compound constitutes (G ').

In the manufacture method of above-mentioned thermally conductive sheet-form molded foam, said mixture (F), said mixture (G) or said mixture (G ') can be with respect to multipolymer (A1) that adds up to 100 mass parts and monomer mixture (A2m), the mixture that further mixes 0.1-5 mass parts silicon-dioxide (C), the median size of primary granule is that 5-20nm and the hydrophobic rate measured by the transmissivity method are below 50% in this silicon-dioxide (C).

In the manufacture method of above-mentioned thermally conductive sheet-form molded foam, the oxyhydroxide of preferred above-mentioned metal (B) is aluminium hydroxide.

Thermally conductive pressure-sensitive adhesive composition of the present invention has sufficient pressure-sensitive-adhesive, simultaneously, the balance excellence of hardness and pressure-sensitive-adhesive, have excellent product having shape-following-up properties, flame retardant resistance, thermal conductivity, smoothness in addition, can be made into the sheet material of easy moulding, resulting sheet can be peeled off with adherend safely and easily after use.Therefore, the thermally conductive sheet-form molded foam that obtains thus can be used as by the heat generating member of plasma display electronic units such as (PDP) etc. efficiently to conducting strip of radiating piece heat conduction etc.

The accompanying drawing summary

[Fig. 1] is the mode chart of the specific embodiments of expression thermally conductive sheet-form molded foam.

Nomenclature

11 front glasses

12 insulator layers

13 protective membranes

14 back side glass

15 at interval

16 radiator element

17 radiating pieces

18 compartments

19 fluorescence

20 electrodes

100 electronic units

The preferred plan that carries out an invention

Below the present invention is described in detail.

Thermally conductive pressure-sensitive adhesive composition of the present invention contains (methyl) acrylate copolymer (A) as first neccessary composition.(methyl) acrylate copolymer (A) is in the presence of 100 mass parts multipolymers (A1), 5-70 mass parts monomer mixture (A2m) polymerization is obtained, described multipolymer (A1) is that the total mass with multipolymer (A1) is benchmark (100% quality), contains the 80-99.9% quality and forms second-order transition temperature (methyl) acrylate monomeric units (a1) for the homopolymer below-20 ℃, the 0.1-20% quality has the monomeric unit (a2) of organic acidic group, the 0-10% quality contains the monomeric unit (a3) of the functional group beyond organic acidic group, and the 0-10% quality can constitute with the monomeric unit (a4) of their copolymerization; Described monomer mixture (A2m) is that the total mass with monomer mixture (A2m) is benchmark (100% quality), contains the 40-100% quality and forms second-order transition temperature and can constitute with the monomer (a7m) of their copolymerization for (methyl) acrylate monomer (a5m) of the homopolymer below-20 ℃, monomer (a6m) that the 0-60% quality has organic acidic group and 0-20% quality; Among the present invention, " (methyl) acrylate " is meant " acrylate " and/or " methacrylic ester ".

Multipolymer (A1) is that the total mass with this multipolymer (A1) is benchmark (100% quality), contains the 80-99.9% quality and forms second-order transition temperature the monomeric unit (a3) of organic acidic group functional group in addition and 0-10% quality can constitute with the monomeric unit (a4) of their copolymerization for (methyl) acrylate monomeric units (a1) of the homopolymer below-20 ℃, monomeric unit (a2), 0-10% quality that the 0.1-20% quality has organic acidic group contain.

Be not particularly limited for producing formation second-order transition temperature (methyl) acrylate monomer (a1m), for example have: ethyl propenoate (second-order transition temperature of homopolymer (being designated hereinafter simply as Tg) :-24 ℃) for (methyl) acrylate monomeric units (a1) of the homopolymer below-20 ℃, propyl acrylate (Tg:-37 ℃), butyl acrylate (Tg:-54 ℃), sec-butyl acrylate (Tg:-22 ℃), vinylformic acid heptyl ester (Tg:-60 ℃), Ethyl acrylate (Tg:-61 ℃), Octyl acrylate (Tg:-65 ℃), 2-EHA (Tg:-50 ℃), vinylformic acid 2-methoxyl group ethyl ester (Tg:-50 ℃), vinylformic acid 3-methoxyl group propyl ester (Tg:-75 ℃), vinylformic acid 3-methoxyl group butyl ester (Tg:-56 ℃), vinylformic acid 2-oxyethyl group methyl esters (Tg:-50 ℃), Octyl methacrylate (Tg:-25 ℃), decyl-octyl methacrylate (Tg:-49 ℃).These (methyl) acrylate monomers (a1m) can be used alone, and also can will be used in combination more than 2 kinds.

These (methyl) acrylate monomers (a1m) are used for polymerization with following amount, promptly in multipolymer (A1), quality with whole multipolymers (A1) is benchmark (100% quality), and making the amount by (methyl) acrylate monomer (a1m) deutero-monomeric unit (a1) is 80-99.9% quality, preferred 85-99.5% quality.The consumption of (methyl) acrylate monomer (a1m) is very few, and near the pressure-sensitive-adhesive of the thermally conductive pressure-sensitive adhesive composition that then obtains thus room temperature reduces.

The monomer (a2m) that has organic acid monomeric unit (a2) for generation is not particularly limited, its representational compound can be the monomer with organic acidic groups such as carboxyl, anhydride group, sulfonic groups, in addition also can use the monomer that contains sulfeno, sulfino, phosphate etc.

Monomeric object lesson with carboxyl for example has: α such as vinylformic acid, methacrylic acid, Ba Dousuan, β-unsaturated monocarboxylic acid; α such as methylene-succinic acid, toxilic acid, fumaric acid, β-unsaturated polycarboxylic acid; α such as methylene-succinic acid methyl esters, toxilic acid butyl ester, fumaric acid propyl ester, β-unsaturated polycarboxylic acid part ester; Deng.Also can use maleic anhydride, itaconic anhydride etc. to have the compound that can derive the group of carboxyl equally by hydrolysis.

Having sulfonic monomeric object lesson has: allyl sulphonic acid, methallyl sulfonic acid, vinyl sulfonic acid, styryl sulfonic acid, acrylamide-α such as 2-methyl propane sulfonic acid, β-unsaturated sulfonic acid and their salt.

These have in the monomer of organic acidic group, preferably have the monomer of carboxyl, wherein preferred vinylformic acid and methacrylic acid.They are low at industrial cost, and obtain easily, with the copolymerization of other monomer component, consider also preferred from productive rate.These monomers (a2m) with organic acidic group can be used alone, and also can will be used in combination more than 2 kinds.

These monomers (a2m) with organic acidic group are used for polymerization with following amount, promptly, in multipolymer (A1), quality with whole multipolymers (A1) is benchmark (100% quality), and making the amount by the monomer with organic acidic group (a2m) deutero-monomeric unit (a2) is 0.1-20% quality, preferred 0.5-15% quality.The consumption of monomer (a2m) is too much, and then the viscosity during polymerization increases significantly, and product solidifies, the application difficult of polymkeric substance.

As mentioned above, the polymerization of the monomer (a2m) of the monomeric unit (a2) with organic acidic group by having organic acidic group imports in the multipolymer, and this is very easy, but also can import organic acidic group by known high molecular weight reactive after generating multipolymer.

Multipolymer (A1) can contain the following monomeric unit (a3) of 10% quality, and this monomeric unit (a3) is by the monomer that contains the functional group except that organic acidic group (a3m) deutero-.

Functional group except that organic acidic group can be hydroxyl, amino, amido, epoxy group(ing), sulfydryl etc.Monomer with hydroxyl can be (methyl) vinylformic acid hydroxyalkyl acrylates such as (methyl) Hydroxyethyl Acrylate, (methyl) vinylformic acid hydroxy propyl ester etc.

Containing amino monomer can be: (methyl) vinylformic acid N, N-dimethylamino methyl esters, (methyl) vinylformic acid N, N-dimethylamino ethyl ester, amino-benzene ethene etc.Monomer with amido can be: α such as acrylamide, Methacrylamide, N hydroxymethyl acrylamide, N-methylol methacrylamide, N,N-DMAA, beta-unsaturated carboxylic acid amide monomer etc.

Monomer with epoxy group(ing) can be: (methyl) glycidyl acrylate, allyl glycidyl ether etc.Monomer with sulfydryl can be (methyl) vinylformic acid-2-sulfydryl ethyl ester etc.The monomer (a3m) that contains the functional group except that organic acidic group can be used alone, and also can will be used in combination more than 2 kinds.

The monomer (a3m) that contains the functional group except that organic acidic group is used for polymerization with following amount, promptly, in multipolymer (A1), quality with whole multipolymers (A1) is benchmark (100% quality), and making the amount by the monomer that contains the functional group except that organic acidic group (a3m) deutero-monomeric unit (a3) is below 10% quality.The consumption of monomer (a3m) is too much, and then the viscosity during polymerization increases significantly, and product solidifies, the application difficult of polymkeric substance.

Multipolymer (A1) is except that above-mentioned monomeric unit (a1), (a2) with (a3), can also contain by can with monomer (a4m) the deutero-monomeric unit (a4) of above-mentioned monomer copolymerization.Monomer (a4m) can be used alone, and also can will be used in combination more than 2 kinds.In the multipolymer (A1), being benchmark (100% quality) with the quality of whole multipolymers (A1), is below 10% quality by the amount of monomer (a4m) deutero-monomeric unit (a4), below preferred 5% quality.

(a4m) is not particularly limited for monomer, its object lesson has: (methyl) acrylate monomer, α except that (methyl) acrylate monomer (a1m) that forms the homopolymer below-20 ℃, the β-complete ester of unsaturated polycarboxylic acid, alkenyl aromatic monomer, conjugated diene monomer, non-conjugated diene are monomer, vinyl cyanide base monomer, the unsaturated alcohol ester of carboxylic acid, ethylene series monomer etc.

The object lesson of (methyl) acrylate monomer except that (methyl) acrylate monomer (a1m) that forms the homopolymer below-20 ℃ has: methyl acrylate (Tg:10 ℃), methyl methacrylate (Tg:105 ℃), Jia Jibingxisuanyizhi (Tg:63 ℃), propyl methacrylate (Tg:25 ℃), butyl methacrylate (Tg:20 ℃) etc.

α, the object lesson of β-complete ester of unsaturated polycarboxylic acid has: dimethyl fumarate, DEF, dimethyl maleate, ethyl maleate, dimethyl itaconate etc.The object lesson of alkenyl aromatic monomer has: vinylbenzene, alpha-methyl styrene, methyl alpha-methyl styrene, Vinyl toluene and Vinylstyrene etc.

The object lesson of conjugate diene monomer has: 1,3-butadiene, 2-methyl isophthalic acid, 3-divinyl, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, chlorbutadiene, cyclopentadiene etc.Non-conjugated diene is that monomeric object lesson has: 1, and 4-hexadiene, Dicyclopentadiene (DCPD), ethylidene norbornene etc.

The monomeric object lesson of vinyl cyanide base has: vinyl cyanide, methacrylonitrile, α-Lv Bingxijing, α-ethyl acrylonitrile etc.The monomeric object lesson of the unsaturated alcohol ester of carboxylic acid has vinyl-acetic ester etc.The monomeric object lesson of ethylene series has: ethene, propylene, butylene, amylene etc.

By measuring through the gel permeation chromatography (GPC method) of polystyrene conversion, the weight-average molecular weight (Mw) of multipolymer (A1) is preferably in 100,000-400,000 scope, the scope particularly preferably in 150,000-300,000.

Multipolymer (A1) can be by making above-mentioned monomer (a1m), (a2m) and monomer (a3m), (a4m) copolymerization being obtained.The polymeric method is not particularly limited, and can be any form of solution polymerization, letex polymerization, suspension polymerization, mass polymerization etc., also can be method in addition.The solution polymerization of aromatic solvents such as carboxylicesters such as ethyl acetate, ethyl lactate or benzene,toluene,xylene as poly-and solvent wherein preferably used in the preferred solution polymerization.During polymerization, monomer can add in the polymerization container in gradation, but preferably with the disposable interpolation of total amount.

Cause poly-and method be not particularly limited, polymerization starter preferably uses thermal polymerization (E1).Thermal polymerization (E1) is not particularly limited, and can be the arbitrary form of peroxidic polymerization initiators and azo-compound polymerization starter.

Peroxidic polymerization initiators can exemplify hydroperoxide such as t-butyl hydroperoxide; Superoxide such as benzoyl peroxide base, cyclohexanone peroxide; Persulphates such as Potassium Persulphate, Sodium Persulfate, ammonium persulphate; Deng.These peroxidic polymerization initiators can with the reductive agent appropriate combination, use as the redox system catalyzer.

The azo-compound polymerization starter can exemplify: 2, and 2 '-Diisopropyl azodicarboxylate, 2,2 '-azo two (2, the 4-methyl pentane nitrile), 2,2 '-azo two (2-methylbutyronitrile) etc.The usage quantity of thermal polymerization (E1) is not particularly limited, and is the scope of 0.01-50 mass parts with respect to 100 mass parts monomers usually.These monomeric other polymerizing conditions (polymerization temperature, pressure, agitation condition etc.) are not particularly limited.

After polyreaction stops, separating obtained multipolymer (A1) from polymerisation medium as required.Separation method is not particularly limited, and when adopting solution polymerization, places decompression down polymeric solution, can obtain multipolymer (A1) by heating up in a steamer polymer solvent.

(methyl) used in the present invention acrylate copolymer (A) is in the presence of the above-mentioned multipolymers that obtain of 100 mass parts (A1), 5-70 mass parts monomer mixture (A2m) polymerization is obtained, described monomer mixture (A2m) is that the quality with whole monomer mixtures (A2m) is benchmark (100% quality), contains the 40-100% quality and forms second-order transition temperature (methyl) acrylate monomer (a5m) for the homopolymer below-20 ℃, the 0-60% quality has the monomer (a6m) of organic acidic group, and the 0-20% quality can constitute with the monomer (a7m) of their copolymerization.

Form second-order transition temperature and can be for the example of (methyl) acrylate monomer (a5m) of the homopolymer below-20 ℃ and polymkeric substance (A1) synthetic in (methyl) acrylate monomer (a1m) same (methyl) acrylate monomer of using.(methyl) acrylate monomer (a5m) can be used alone, and also can will be used in combination more than 2 kinds.

In the monomer mixture (A2m), be benchmark (100% quality) with the quality of whole monomer mixtures (A2m), the ratio of (methyl) acrylate monomer (a5m) is the 40-100% quality, preferred 60-95% quality.The ratio of (methyl) acrylate monomer (a5m) is very few, then uses the pressure-sensitive-adhesive or the flexibility deficiency of the thermally conductive pressure-sensitive adhesive composition that alkylmethacrylate polymer (A) obtains.

Example with monomer (a6m) of organic acidic group can be with multipolymer (A1) synthetic in the same monomer that is exemplified as monomer (a2m) that uses with organic acidic group.Monomer (a6m) with organic acidic group can be used alone, and also can will be used in combination more than 2 kinds.

In the monomer mixture (A2m), be benchmark (100% quality) with the quality of whole monomer mixtures (A2m), the ratio with monomer (a6m) of organic acidic group is the 0-60% quality, preferred 5-40% quality.The ratio of monomer (a6m) with organic acidic group is too much, then uses the hardness of the thermally conductive pressure-sensitive adhesive composition that multipolymer (A) obtains to raise the particularly reduction of the pressure-sensitive-adhesive high temperature (100 ℃) under.

Can be with the example of the monomer (a7m) of above-mentioned monomer (a5m) and monomer (a6m) copolymerization with multipolymer (A1) synthetic in the same monomer that is exemplified as monomer (a3m) and monomer (a4m) that uses.

But the monomer of copolymerization (a7m) can use the polyfunctional monomer with 2 above polymerizability unsaturated link(age)s.By making the polyfunctional monomer copolymerization, can in multipolymer, import intramolecularly and/or intermolecular cross-linking, can improve the cohesive force of pressure sensitive adhesive.

Polyfunctional monomer can use two (methyl) vinylformic acid 1,6-hexylene glycol ester, two (methyl) vinylformic acid 1, the 2-glycol ester, two (methyl) vinylformic acid 1,12-dodecanediol ester, poly-two (methyl) vinylformic acid glycol ester, poly-two (methyl) vinylformic acid propylene glycol ester, two (methyl) vinylformic acid DOPCP, two (methyl) vinylformic acid pentaerythritol ester, trimethylolpropane tris (methyl) acrylate, three (methyl) vinylformic acid pentaerythritol ester, two (TriMethylolPropane(TMP)) triacrylate, four (methyl) vinylformic acid pentaerythritol ester, polyfunctional group (methyl) acrylate such as six (methyl) vinylformic acid dipentaerythritol ester; 2, two (the trichloromethyl)-6-of 4-are to replacement triazines such as methoxy styrene-5-triazines; The unsaturated aromatic ketones of single ethylenic such as 4-propenyloxy group benzophenone; Deng.

The amount of monomer mixture (A2m) is 5-70 mass parts, preferred 10-50 mass parts with respect to 100 mass parts multipolymers (A1).The amount of monomer mixture (A2m) is very few, then can't be with oxyhydroxide (B) uniform mixing of (methyl) acrylate copolymer (A) with metal, the reductions such as thermal conductivity of gained thermally conductive sheet-form molded foam.On the other hand, the amount of monomer mixture (A2m) is too much, and then polyreaction can't fully be carried out, and the unreacted monomer that can occur in the gained thermally conductive sheet-form molded foam produces problems such as foul smell.

Make monomer mixture (A2m) polymeric condition in the presence of 100 mass parts multipolymers (A1) except the method for initiated polymerization, all the other are not particularly limited, can be according to carrying out with the synthetic same condition of multipolymer (A1).Among the present invention, in the presence of multipolymer (A1), make the method for monomer mixture (A2m) polymeric initiated polymerization be to use thermal polymerization (E2).Use Photoepolymerizationinitiater initiater to replace thermal polymerization, then the bond strength of the foaming sheet that is formed by the gained thermally conductive pressure-sensitive adhesive composition is poor.

Thermal polymerization (E2) can be with multipolymer (A1) synthetic in the thermal polymerization congener matter that is exemplified as polymerization starter (E1) used, wherein preferred one minute half life temperature is the material more than 120 ℃, below 170 ℃.The consumption of thermal polymerization (E2) is not particularly limited, and is 0.1-50 mass parts scope with respect to 100 mass parts monomer mixtures (A2m) usually.

The polymerisation conversion of monomer mixture (A2m) is preferably more than 95% quality.Polymerisation conversion is low excessively, and then the gained thermally conductive sheet-form molded foam is residual a monomer stink, not preferred.

The feature of thermally conductive pressure-sensitive adhesive composition of the present invention is: have the oxyhydroxide (B) of (methyl) acrylate copolymer (A) and metal, above-mentioned (methyl) acrylate copolymer (A) foaming.

The oxyhydroxide of metal (B) has: lithium hydroxide, sodium hydroxide, potassium hydroxide, beryllium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, hydrated barta, ironic hydroxide, zinc hydroxide, aluminium hydroxide, gallium hydroxide, indium hydroxide etc.Be preferably the oxyhydroxide of the metal of the periodic table of elements the 2nd family or the 13rd family.

The metal of the 2nd family can exemplify: magnesium, calcium, strontium, barium etc., the metal of the 13rd family can exemplify: aluminium, gallium, indium etc.The oxyhydroxide of these metals (B) can be used alone, and also can will be used in combination more than 2 kinds.By using the oxyhydroxide (B) of metal, can make thermally conductive pressure-sensitive adhesive composition of the present invention have thermal conductivity and excellent flame.

The shape of the oxyhydroxide of metal (B) is not particularly limited, and can be the arbitrary form of spherical, needle-like, fibrous, flakey, dendroid, tabular and indefinite shape.In the example of the oxyhydroxide of above-mentioned metal (B), preferred especially aluminium hydroxide.By using aluminium hydroxide, can make thermally conductive pressure-sensitive adhesive composition of the present invention have excellent thermal conductivity, particularly have excellent flame.

The particle diameter of the oxyhydroxide of spheric metal (B) usually preferred 0.2-150 μ m, more preferably 0.7-100 μ m.The preferred 1-80 μ of the median size m of the oxyhydroxide of spheric metal (B).Median size is too small, the viscosity of thermally conductive pressure-sensitive adhesive composition is increased, and the oxyhydroxide of (methyl) acrylate copolymer and metal (B) is difficult to mixing, in addition, hardness also increases simultaneously, and the product having shape-following-up properties of thermally conductive sheet-form molded foam is reduced.

On the other hand, median size is excessive, and then thermally conductive pressure-sensitive adhesive composition or thermally conductive sheet-form molded foam become too soft, pressure sensitive adhesion exceedingly, or bond strength descends under the high temperature, or thermal distortion under the high temperature.

Among the present invention, the consumption of the oxyhydroxide of metal (B) is the scope of 70-170 mass parts with respect to 100 mass parts (methyl) acrylate copolymers (A).The consumption of the oxyhydroxide of metal (B) is very few, then has the problem of high-temperature bond strength, thermal conductivity decline, and on the contrary, crossing has the problem that hardness increases, product having shape-following-up properties reduces at most.

Thermally conductive pressure-sensitive adhesive composition of the present invention is characterised in that: (methyl) acrylate copolymer (A) foaming.Expansion ratio is not particularly limited, preferred 1.05 times-1.4 times.By adopting the expansion ratio of this scope, can obtain the thermally conductive pressure-sensitive adhesive composition of hardness and pressure sensitive adhesion sexual balance excellence and product having shape-following-up properties excellence.

The method of foaming is not particularly limited, and can make in all sorts of ways.For example, with oxyhydroxide (B) mixing of multipolymer (A1), monomer mixture (A2m) and metal, for the syrupy shape heavy-gravity mixture that produces, (1) is by stirring the method for the air in the picked-up atmosphere; (2) be blown into the method for gases such as nitrogen; (3) by stirring, with the form picked-up water of particulate etc. and multipolymer (A1) or the low fluidic method of monomer mixture (A2m) consistency; (4), make the fluid that is dissolved in the viscous mixture produce the method for bubble or vacuole by decompression or heating; (5) sneak into the photolysis whipping agent that decomposes by light, the method for irradiates light then; (6) sneak into the pyrolytic whipping agent that decomposes by heat, the method that heats then; Deng.Preferably use whipping agent among the present invention, particularly foam by the hot whipping agent (pyrolytic whipping agent) that decomposes and produce gas.

The example of pyrolytic whipping agent has p, p '-oxygen base two (benzol sulfohydrazide), azodicarboamide etc.The consumption of whipping agent is preferably the 0.1-3 mass parts with respect to 100 mass parts (methyl) acrylate copolymers (A), more preferably the 0.3-2 mass parts.Like this,, expansion ratio preferred range can be adjusted to, the thermally conductive pressure-sensitive adhesive composition of hardness and pressure sensitive adhesion sexual balance excellence and product having shape-following-up properties excellence can be obtained by selecting the usage quantity of whipping agent.

The thermally conductive sheet-form molded foam with thermally conductive pressure-sensitive adhesive composition of the present invention that uses in the electronic unit etc. can easily obtain the high sheet material of sheet material smoothness, can easily prevent the precipitation of pigment and weighting agent during life-time service or separate, for the above-mentioned reasons, must make the yield-point height in low shearing speed territory.In order to improve described yield-point, add in the preferred thermally conductive pressure-sensitive adhesive composition of the present invention so-called " gelating agent ".

In the thermally conductive pressure-sensitive adhesive composition of the present invention, in order to improve the sheet material smoothness and the molding processability of thermally conductive sheet-form molded foam simultaneously, the preferred use has the silicon-dioxide of specific trait as gelating agent.

As the silicon-dioxide of described specific trait, the median size that can use primary granule among the present invention is a silicon-dioxide (C) below 50% as 5-20nm and by the hydrophobic rate that the transmissivity method is measured.

The median size of the primary granule of the silicon-dioxide that uses among the present invention (C) is 5-20nm.The median size of primary granule is too small, and then the applicability of thermally conductive pressure-sensitive adhesive composition reduces, and is not suitable for, and the median size of primary granule is excessive in addition, and secondary aggregation then takes place easily, and is not preferred.

Here, the median size of primary granule is to use size distribution curve to obtain in the silicon-dioxide (C), and described size distribution curve is to be that the measurement result of the light scattering method of light source is made by the measurement result of the one-level median size by electron microscope observation with the laser beam.

The hydrophobic rate that the silicon-dioxide that uses among the present invention (C) is measured by the transmissivity method is below 50%.The above-mentioned hydrophobic rate of silicon-dioxide (C) is excessive, and then thermally conductive pressure-sensitive adhesive composition generation heat flow is not suitable for.In addition, from the angle of sheet material smoothness, the silicon-dioxide that uses among the present invention (C) is below 30% by the hydrophobic rate that the transmissivity method is measured more preferably, and especially preferably the hydrophobic rate of being measured by the transmissivity method is below 10%.

Here, " by the hydrophobic rate of transmissivity method mensuration " measured by following method.

Get the 1g silicon-dioxide 200ml separating funnel of packing into, in separating funnel, add the 100ml pure water then.Then, separating funnel is contained on -Block ラ mixing machine with 90rpm dispersion 10 minutes.Separating funnel is left standstill 10 minutes again, from funnel, take out the lower floor of 20-30ml separating funnel then.The separatory that 10ml is taken out by the lower floor quartzy cell of packing into is blank with the pure water, the spectrophotometer of packing into.By the transmissivity of spectrophotometric determination wavelength 500nm, be hydrophobic rate with this transmissivity.

In the thermally conductive pressure-sensitive adhesive composition of the present invention,, preferably contain the 0.1-5 mass parts, more preferably 0.5-2 mass parts silicon-dioxide (C) with respect to 100 mass parts (methyl) acrylate copolymers (A).That is to say, in the preparation of thermally conductive pressure-sensitive adhesive composition of the present invention,, preferably mix the 0.1-5 mass parts, more preferably 0.5-2 mass parts silicon-dioxide (C) uses with respect to multipolymer (A1) that adds up to 100 mass parts and monomer mixture (A2m).Consumption by making silicon-dioxide (C) is in above-mentioned scope, and the viscosity of thermally conductive pressure-sensitive adhesive composition of the present invention can keep suitably, and the sheet material smoothness of thermally conductive sheet-form molded foam of the present invention is improved.Here, in the thermally conductive pressure-sensitive adhesive composition of the present invention, use parallel plate type visco-elasticity rheometer (manufacturing of Rheometric Scientific company) range of viscosities that measure, 60 ℃ to be preferably 100-600 (Pas), more preferably 200-400 (Pas).

It is that 120-200 ℃ and molecular weight are lower than 1000 compound (D) that thermally conductive pressure-sensitive adhesive composition of the present invention can contain fusing point.Compound (D) thermally conductive pressure-sensitive adhesive composition of the present invention as normally used temperature such as PDP radiator element under (about below 100 ℃) exist with solid form, after the use, at cycling and reutilization or the processing mode when discarded be: the temperature that is heated to 120-200 ℃, make its overflow (oozing out) between adherend and the thermally conductive sheet-form molded foam, be the surface of thermally conductive sheet-form molded foam, make it have easy separability.

Compound (D) is not particularly limited so long as fusing point is 120-200 ℃ and molecular weight is lower than 1000 compound and gets final product.Fusing point is low excessively, then thermally conductive pressure-sensitive adhesive composition of the present invention as normally used temperature such as PDP radiator element under (about below 100 ℃) be in the state of peeling off easily, radiator element has the possibility that splits away off from adherend.On the other hand, fusing point is too high, and then the heat treated temperature must surpass 200 ℃, and therefore generation (methyl) acrylate copolymer (A) decomposes or burns, and separability may reduce.In addition, the molecular weight of compound (D) is more than 1000, even then reach fusing point, viscosity is also high, is difficult to overflow, and is difficult to make it to have easy separability.

Above-claimed cpd (D) is preferably fusing point 120-200 ℃ and molecular weight and is lower than 1000 aliphatic amide compound.Described compound for example has: methylene-bis stearylamide (fusing point: 130 ℃), ethylenebisstearamide (fusing point: 145 ℃), ethylenebis laurylamide (fusing point: 157 ℃), ethylenebis decyl amide (fusing point: 161 ℃), bis-stearamides (fusing point: 137 ℃), bimonthly osmanthus acid amides (fusing point: 143 ℃) etc.They can be used alone, and also can will be used in combination more than 2 kinds.

In the thermally conductive pressure-sensitive adhesive composition of the present invention, with respect to 100 mass parts (methyl) acrylate copolymers (A), the content of compound (D) is preferably the 0.05-10 mass parts, more preferably 0.2-8 mass parts, further preferred 0.3-5 mass parts.Promptly, in the preparation of thermally conductive pressure-sensitive adhesive composition of the present invention, with respect to multipolymer (A1) that adds up to 100 mass parts and monomer mixture (A2m), preferably mix the 0.05-10 mass parts, more preferably 0.2-8 mass parts, further preferred 0.3-5 mass parts compound (D) use.

The usage quantity of compound (D) is in above-mentioned scope, and then easily the separability performance is good, and it is good that the binding property of the thermally conductive pressure-sensitive adhesive composition under the common in addition use temperature also can keep.

Thermally conductive pressure-sensitive adhesive composition of the present invention also can contain pigment, other weighting agent, other gives the known various additives such as material, fire retardant, antiaging agent, thickening material, viscosity imparting agent of thermal conductivity as required except that the oxyhydroxide (B) that contains (methyl) acrylate copolymer (A), metal according to aforementioned proportion and the above-mentioned whipping agent that contains as required, above-mentioned silicon-dioxide (C) and above-claimed cpd (D).

Pigment such as carbon black or titanium dioxide etc. all can use regardless of organic system, inorganic system.Other packing material has mineral compound such as clay etc.Also can add nano particles such as soccerballene or carbon nanotube.

Other give thermal conductivity material, be that the material of giving thermal conductivity beyond the oxyhydroxide of metal has mineral compound such as boron nitride, aluminium nitride, silicon nitride, aluminum oxide, magnesium oxide.

Fire retardant can be ammonium polyphosphate, zinc borate, tin compound, organophosphorus based compound, red phosphorus based compound, silicon-type fire retardant material.Antiaging agent suppresses the possibility height of radical polymerization, does not therefore use usually, can use antioxidants such as polyphenol system, quinhydrones system, hindered amine system as required.

Thickening material can use mineral compound particulate, magnesium oxide isoreactivity mineral compound such as acrylic acid polymer particle, silica particle.The viscosity imparting agent can exemplify: terpenic series resin, terpenes phenol are that resin, rosin series resin, petroleum line resin, coumarone-indene resin, phenolic aldehyde are resin, hydrogenated wood rosin glycerol ester, nilox resin ester, xylene resin etc.

For the cohesive force that improves pressure sensitive adhesive, in order to improve thermotolerance etc., can add outside cross-linking agent in the thermally conductive pressure-sensitive adhesive composition of the present invention, import crosslinking structure to multipolymer.

Outside cross-linking agent can be: many functional group isocyanates such as tolylene diisocyanate, TriMethylolPropane(TMP) vulcabond, ditan triisocyanate are linking agent; Epoxies such as diglycidylether, polyethyleneglycol diglycidylether, trihydroxymethylpropanyltri diglycidyl ether are linking agent; Trimeric cyanamide is a resin cross-linking agent; Aminoresin is linking agent; Metal-salt is a linking agent; Metal chelator is a linking agent; Peroxidation system linking agent; Deng.

Outside cross-linking agent is to obtain (methyl) acrylate copolymer (A) back to wherein adding, handling by carrying out heat treated or radiation exposure, can be crosslinked in the intramolecularly and/or the intermolecular formation of (methyl) acrylate copolymer (A).

To from (methyl) acrylate copolymer (A), the oxyhydroxide of metal (B), and the whipping agent that uses as required, the method of silicon-dioxide (C) and compound acquisition thermally conductive pressure-sensitive adhesive compositions of the present invention such as (D) is not particularly limited, it can be oxyhydroxide mixing such as (B) with other synthetic (methyl) acrylate copolymer (A) and metal, the method that foams, but from making the oxyhydroxide mixed uniformly angles such as (B) of (methyl) acrylate copolymer (A) and metal, preferably before facing the synthetic and foaming of carrying out (methyl) acrylate copolymer (A), with the oxyhydroxide blended methods such as (B) of metal.

Employing is with the oxyhydroxide (B) of metal etc. and synthetic (methyl) acrylate copolymer (A) mixes in addition, during the method for foaming, be not particularly limited for the blended method, for example can be to use roller, Henschel agitator, kneader etc. that the oxyhydroxide (B) of exsiccant (methyl) acrylate copolymer (A) and metal is carried out the blended dry-mix process, also can be the blended wet mixing method of carrying out in possessing the container of stirrer, in the presence of organic solvent.

Employing face carry out the synthetic of (methyl) acrylate copolymer (A) and foaming before during with the oxyhydroxide blended methods such as (B) of metal, preferably behind the mixture of the oxyhydroxide (B) that obtains multipolymer (A1), monomer mixture (A2m), thermal polymerization (E2), metal and whipping agent, silicon-dioxide (C) and the compound (D) etc. that use as required, under polymerizing condition, foam and heat.At this moment, the order by merging of each composition is not particularly limited.In addition, preferably do not implement to mix under the polymeric temperature at monomer mixture (A2m).

Thermally conductive pressure-sensitive adhesive composition of the present invention can be made into thermally conductive sheet-form molded foam by making sheet material.Thermally conductive sheet-form molded foam can only contain thermally conductive pressure-sensitive adhesive composition, also can be to contain base material and the mixture of the layer of the thermally conductive pressure-sensitive adhesive composition that forms on its one or both sides.

The thickness of the thermally conductive pressure-sensitive adhesive composition layer in the thermally conductive sheet-form molded foam of the present invention is not particularly limited, and is generally 50 μ m-3mm.The thickness of thermally conductive pressure-sensitive adhesive composition layer is thin excessively, is involved in air when then pasting heat generating member and radiating piece easily, and the possibility of result can not get enough thermal conductivity.On the other hand, the thickness of thermally conductive pressure-sensitive adhesive composition layer is blocked up, and then the thermal resistance of sheet material increases, and exothermicity may be impaired.

Base material during for the layer that forms thermally conductive pressure-sensitive adhesive composition at the one or both sides of base material is not particularly limited.Its object lesson has: the metal of excellent thermal conductivity such as aluminium, copper, stainless steel, beryllium and the paper tinsel shape thing of alloy; The flap that contains the polymkeric substance of itself excellent thermal conductivity such as heat-conductive silicone; The thermal conductivity plastic film that contains the thermal conductivity filler; Various non-wovens; Woven fiber glass; Honeycomb structured body; Deng.Plastic film in the above-mentioned thermal conductivity plastic film can use the film of thermally stable polymers such as containing polyimide, polyethylene terephthalate, PEN, tetrafluoroethylene, polyetherketone, polyethersulfone, polymethylpentene, polyetherimide, polysulfones, polyphenylene sulfide, polyamidoimide, polyester-imide, aromatic poly.

The method that is prepared thermally conductive sheet-form molded foam by thermally conductive pressure-sensitive adhesive composition is not particularly limited, and for example thermally conductive pressure-sensitive adhesive composition can be coated on the engineering paper such as polyester film that carried out lift-off processing.Also can be as required, thermally conductive pressure-sensitive adhesive composition is clipped in the middle of two engineering paper that carried out lift-off processing, cross running roller, make sheet.When extruding, can also pass through the overflow mould control thickness by forcing machine.

Can also be the one or both sides of for example thermally conductive pressure-sensitive adhesive composition being coated base material, heat with hot blast, electric heater, infrared rays etc., can obtain containing base material and the thermally conductive sheet-form molded foam of the layer of the thermally conductive pressure-sensitive adhesive composition that forms at its one or both sides.Thermally conductive pressure-sensitive adhesive composition of the present invention can be on base materials such as radiating piece directly forms thermally conductive sheet-form molded foam, provides with the form of the part of electronic unit.

Thermally conductive sheet-form molded foam of the present invention preferably obtains by the preparation method with following steps: with 100 mass parts multipolymers (A1), 5-70 mass parts monomer mixture (A2m), with respect to 100 mass parts monomer mixtures (A2m) is the thermal polymerization (E2) of 0.1-50 mass parts, mix the step that forms mixture (F) with respect to the multipolymer (A1) that adds up to 100 mass parts for the metal hydroxides (B) of 70-170 mass parts with monomer mixture (A2m), make the step of mixture (F) foaming, the step of heated mixt (F), and the step that makes mixture (F) sheetization; Wherein said multipolymer (A1) is to be 100% quality with whole multipolymers (A1), contains the 80-99.9% quality and forms second-order transition temperature the monomeric unit (a3) of organic acidic group functional group in addition and 0-10% quality can constitute with the monomeric unit (a4) of their copolymerization for (methyl) acrylate monomeric units (a1) of the homopolymer below-20 ℃, monomeric unit (a2), 0-10% quality that the 0.1-20% quality has organic acidic group contain; Monomer mixture (A2m) is to be 100% quality with whole monomer mixtures (A2m), contains the 40-100% quality and forms second-order transition temperature and can constitute with the monomer (a7m) of their copolymerization for (methyl) acrylate monomer (a5m) of the homopolymer below-20 ℃, monomeric unit (a6m) that the 0-60% quality has organic acidic group and 0-20% quality.

According to this method, only can make the thermally conductive sheet-form molded foam that forms by thermally conductive pressure-sensitive adhesive composition have high-temperature bond strength with thermal treatment, have simultaneously by the pressure-sensitive-adhesive of low temperature, and this is in the past if debond uses photopolymerization or photo-crosslinking just to be difficult to realize to the wide temperature range of pyritous.

The step that the step that mixture (F) is foamed preferably makes mixture (F) doubly foam with expansion ratio 1.05-1.4.

It can be that further to be mixed with fusing point be that 120-200 ℃ and molecular weight are lower than the mixture (G) that 1000 compound (D) constitutes that the oxyhydroxide (B) of multipolymer (A1), monomer mixture (A2m), thermal polymerization (E2), metal is mixed the mixture (F) that forms.Here, with respect to multipolymer (A1) that adds up to 100 mass parts and monomer mixture (A2m), compound (D) is preferably with 0.05-10 mass parts, the more preferably mixed of 0.2-8 mass parts, further preferred 0.3-5 mass parts.

Mixture (F) can be that further to be mixed with fusing point be 120-200 ℃ and the molecular weight mixture that is lower than 1000 aliphatic amide compound and constitutes (G ').Here, aliphatic amide compound with the same mixed of above-claimed cpd (D).

Said mixture (F), mixture (G) or mixture (G ') can also be further to be mixed with silicon-dioxide (C) and the mixture that constitutes, and the median size of primary granule is that 5-20nm and the hydrophobic rate measured by the transmissivity method are below 50% in the described silicon-dioxide (C).Here, with respect to multipolymer (A1) that adds up to 100 mass parts and monomer mixture (A2m), silicon-dioxide (C) is preferably with 0.1-5 mass parts, the more preferably mixed of 0.5-2 mass parts.

Among the preparation method of above-mentioned thermally conductive sheet-form molded foam, the oxyhydroxide of metal (B) is preferably aluminium hydroxide.

At this moment, can be with multipolymer (A1), monomer mixture (A2m), thermal polymerization (E2), oxyhydroxide of metal (B) and the whipping agent that uses as required mix under heating, form mixture (F), make its foaming, then the gained mixture is made sheet (this method is called " method for making (I) "), but preferably with multipolymer (A1), monomer mixture (A2m), thermal polymerization (E2), oxyhydroxide of metal (B) and the whipping agent that uses as required mix, form mixture (F), make its foaming, heat simultaneously and make sheet (this method is called " method for making (II) ").Foaming in the above-mentioned method for making (II) can be under heating with make sheet and carry out simultaneously, also can carry out under the non-heating, before making sheet.

In the method for making (I), the whipping agent of the oxyhydroxide (B) of multipolymer (A1), monomer mixture (A2m), thermal polymerization (E2), metal and use is as required mixed under heating, form mixture (F), make its foaming, with oxyhydroxide (B) uniform mixing of gained (methyl) acrylate copolymer (A) and metal, the thermally conductive pressure-sensitive adhesive composition of foaming is made sheet then.

Blending means is not particularly limited, and in order to carry out the polymerization of multipolymer (A1) and monomer mixture (A2m), the oxyhydroxide (B) that makes gained (methyl) acrylate copolymer (A) and metal is uniform mixing positively, preferably uses intensive mixer.Mixing can also can be carried out continuously with intermittent type.The order by merging of each composition is not particularly limited.

Batch mixer has: high viscosity raw materials such as mixing and kneading machine, kneader, Banbury mixer, planetary mixer are with mixing roll or stirrer.The continous way mixing machine has: will rotate and the mixing roll of Off ア レ Le type continuous mixer that spiral combination obtains etc. or screw type special construction.Extrude the single screw extrusion machine or the twin screw extruder that use in the processing in addition.These forcing machines or mixing roll can be used in combination of two or more, and also multiple homotype mechanical connection can be used.Wherein from the angle of continuity and velocity of shear, preferred twin screw extruder.

Heating temperature must be the temperature that polymerization and foaming are carried out smoothly, preferred 100-200 ℃ usually, and more preferably 120-160 ℃.Atmosphere when heating mixes is not particularly limited so long as can carry out the atmosphere of radical polymerization and get final product.Heating is mixed the thermally conductive pressure-sensitive adhesive composition obtain make flaky method and be not particularly limited, have it is clipped in the method for crossing running roller between the engineering paper, crosses the method for pressing mold etc. when extruding from mixing roll.

In the method for making (II),, foam, heat simultaneously and make sheet with the oxyhydroxide (B) of multipolymer (A1), monomer mixture (A2m), thermal polymerization (E2), metal and after the whipping agent that uses as required mixes.Foaming can be under heating with make sheet and carry out simultaneously, also can carry out under the non-heating, before making sheet.

The mixing machine that is used for preparing mixture can be and the employed identical mixing machine of method for making (I).The order by merging of each composition is not particularly limited.Temperature when mixing each composition is below 60 ℃.To mix than 60 ℃ of high temperature, then in mixing, monomer mixture (A2m) begins polymerization, and viscosity raises, and it is difficult that operation afterwards becomes.

Then, each mixture of ingredients is foamed, heat simultaneously and make sheet.In the time of will foaming, heat and make sheet and carry out simultaneously, by heating, foam by the pyrolytic whipping agent with the polymerization of monomer mixture (A2m) and according to condition by multipolymer (A1), make sheet simultaneously, can form thermally conductive sheet-form molded foam.When foaming under the non-heating, before making sheet, by make the foaming before the sheet with the method beyond the foaming of pyrolytic whipping agent.

Heating temperature is preferably 100 ℃-200 ℃, more preferably 120 ℃-160 ℃.Heating temperature is low excessively, and then the polyreaction of monomer mixture (A2m) can not fully be carried out, and unreacted monomer may occur and produce problems such as foul smell.Heating temperature is too high, and then bad orders such as tonal variation that cause because of so-called " burning " etc. may appear in the gained thermally conductive sheet-form molded foam.

When making sheet, even in order to make thickness, preferably pressurize.Pressurized conditions is generally below the 10MPa, below the preferred 1MPa.Surpass the 10MPa pressurization, then foam hole may break, and is not preferred.Can select optimum point clamping time according to the kind of temperature condition or used polymerization starter, amount etc., but consider from productive rate, in preferred 1 hour.

Embodiment

＜embodiment, comparative example 〉

Below provide embodiment, further describe the present invention.If no special instructions, part and the % among the embodiment is quality criteria.

Each evaluating characteristics of (methyl) acrylate copolymer (A), thermally conductive pressure-sensitive adhesive composition and thermal conductivity foaming sheet is as follows.

(1) weight-average molecular weight (Mw) of (methyl) acrylate copolymer (A) and number-average molecular weight (Mn)

Weight-average molecular weight (Mw) of (methyl) acrylate copolymer (A) and number-average molecular weight (Mn) convert through polystyrene standard and obtain by with the tetrahydrofuran (THF) being the gel permeation chromatography that launches solvent.

(2) expansion ratio of thermally conductive sheet-form molded foam

With the volume of thermally conductive sheet-form molded foam unit mass volume, with the value of gained thus expansion ratio as thermally conductive sheet-form molded foam divided by the sheet-form molded unit mass of thermal conductivity that do not foam of same composition.

(3) hardness of thermally conductive sheet-form molded foam

The hardness of thermally conductive sheet-form molded foam is measured according to Japan rubber association specification (SRIS) Shao Er C type hardness tester method.

(4) thermal conductivity of thermally conductive sheet-form molded foam

The thermal conductivity of thermally conductive sheet-form molded foam is by rapid thermal conductivity meter (QTM-500, capital of a country Electronics Industry Company make), at room temperature obtain.

(5) the room temperature bond strength of thermally conductive sheet-form molded foam

Test film and the aluminium sheet of 25mm * 125mm is overlapping, with the running roller pressing of 2kg, placed then 1 hour.This sample is fixed in the thermostatic bath that is set to room temperature, to measure the maximum bond strength of 90 degree directions in draw speed 50mm/ minute, with the room temperature bond strength of this value as thermally conductive sheet-form molded foam.

(6) high-temperature bond strength of thermally conductive sheet-form molded foam

The temperature of thermostatic bath is made as 100 ℃, in addition same with the experiment of room temperature bond strength, obtain the high-temperature bond strength of thermally conductive sheet-form molded foam.

(7) product having shape-following-up properties of thermally conductive sheet-form molded foam

Test film loam cake upper glass plates at 50mm * 100mm applies 20g/cm on this sheet glass ²(1.96 * 10 ³Pa) stress 30 seconds.Remove stress, carry out 3 days state adjustment, measure the ratio of the area of fitting then with glass surface.Estimate the product having shape-following-up properties of thermally conductive sheet-form molded foam by this value.This value is big approximately, and then product having shape-following-up properties is good more

(8) flame retardant resistance

Test according to UL specification UL94 " machine part with the combustion test method of plastic material ", flame retardant resistance is estimated.The sample of short strip shape is carried out the igniting in 10 seconds, carry out the 2nd time igniting in 10 seconds after flaming combustion (lingering flame burn) finishes immediately, the test subject shown in the his-and-hers watches 1 is estimated.Identical sample type is respectively carried out 5 tests, according to its result, and the burning grade separation shown in carry out table 1.

[table 1]

(table 1)

The burning grade separation	UL94V-0	UL94V-1	UL94V-2
				Flaming combustion time maximum value	≤ 10 seconds	≤ 30 seconds	≤ 30 seconds
The aggregate value of the flaming combustion time sum after lighting a fire for the 1st time and the 2nd time	≤ 50 seconds	≤ 250 seconds	≤ 250 seconds
				The maximum value that flame time and flameless combustion time sum are arranged after the 2nd igniting	≤ 30 seconds	≤ 60 seconds	≤ 60 seconds
Cotton the igniting of dropping confrontation	Do not have	Do not have	Have
				To the clip place flame or flameless combustion arranged	Do not have	Do not have	Do not have

In the table 1, " flaming combustion time maximum value " is meant the maximum value of the flaming combustion time that each 5 sample obtains respectively." aggregate value of the flaming combustion time sum after the 1st time and the 2nd time igniting " is meant the aggregate value of the flaming combustion time sum that each 5 sample obtains respectively." residence time after the 2nd igniting and the maximum value of flameless combustion time sum " is meant each 5 maximum value that flame time and flameless combustion time sum are arranged that sample obtains respectively." nothing " is meant for 5 samples all is not have.

(embodiment 1)

In reaction vessel, add 100 parts contain 94% 2-EHA and 6% acrylic acid monomer mixture, 0.03 part 2,2 '-Diisopropyl azodicarboxylate and 700 parts of ethyl acetate, uniform dissolution after the nitrogen displacement, is carried out 6 hours polyreactions at 80 ℃.Polymerisation conversion is 97%.With the resulting polymers drying under reduced pressure, make the ethyl acetate evaporation, obtain sticking solid state multipolymer (A1) (1).The Mw of multipolymer (A1) (1) is 280,000, Mw/Mn is 3.1.

Add 100 parts of multipolymers (A1) (1) at mixing and kneading machine in the lump in mortar; 44.5 part is contained 50.6% butyl acrylate; 11.2% methacrylic acid; 33.7% 2-EHA and the 4.5% polydimethyl vinylformic acid glycol ester (repeat number of oxygen ethylene chain=about 23; the manufacturing NK ester 23G (polydimethyl vinylformic acid glycol ester #1000) of Xin Zhong village chemical industrial company) monomer mixture (A2m) (1) of (being designated hereinafter simply as " PEGDMA "); 1.6 part 1; two (tert-butyl peroxide)-3 of 1-; 3; 5-trimethylcyclohexanone (hereinafter to be referred as " TMCH ") [1 minute half life temperature is 149 ℃]; 1.0 part pyrolytic whipping agent p; two (benzol sulfohydrazide) (hereinafter to be referred as " OBSH ") of p '-oxygen base; and 200 parts of aluminium hydroxides, at room temperature mix with mixing and kneading machine.At this moment, aluminium hydroxide is 138 parts with respect to adding up to 100 parts the multipolymer (A1) (1) and the mass ratio of monomer mixture (A2m) (1).Deaeration while stirring under reduced pressure then obtains the aqueous sample of viscosity.Spread the polyester film of band releasing agent in the mould bottom surface of vertical 400mm, horizontal 400mm, dark 2mm, then this sample is filled with mould, thereon the polyester film of cover tape releasing agent.It is taken out from mould, in 155 ℃ hotblast stove, carry out 30 minutes polymerization and foaming, obtain the thermally conductive sheet-form molded foam (1) that the two sides is coated by the polyester film with releasing agent.Levels of residual monomers from sheet is calculated the polymerisation conversion of monomer mixture (A2m), and the result is 99.9%.This thermally conductive sheet-form molded foam (1) is carried out the evaluation of each characteristic.The result is as shown in table 2.

(comparative example 1)

Use 200 parts of aluminum oxide to replace 200 parts of aluminium hydroxides, in addition carry out operation similarly to Example 1, obtain the thermally conductive sheet-form molded foam (2) that the two sides is coated by the polyester film with releasing agent.This thermally conductive sheet-form molded foam (2) is carried out the evaluation of each characteristic.The result is as shown in table 2.

(comparative example 2)

Remove and not use p, p '-oxygen base two (benzol sulfohydrazide) (OBSH) outside, carry out operation similarly to Example 1, the thermal conductivity that is not foamed sheet-form molded (3).This thermal conductivity sheet-form molded (3) is carried out the evaluation of each characteristic.The result is as shown in table 2.

[table 2]

Following as shown in Table 2 content.

Mix at oxyhydroxide (B) multipolymer (A1), monomer mixture (A2m), thermal polymerization (E2), pyrolytic whipping agent and metal, obtain mixture, under heating, carry out polymerization, foam and make sheet, among the embodiment 1 of preparation thermally conductive sheet-form molded foam, it is good to have obtained hardness, and the thermally conductive sheet-form molded foam of bond strength, product having shape-following-up properties and excellent in flame retardance.Relative therewith, form but replace with aluminum oxide in the comparative example 1 of aluminium hydroxide having whole monomers identical with embodiment 1, the result is a poor fire.2 kinds of the comparative examples that does not foam, the result is that product having shape-following-up properties is poor.

Below, in order to help to understand the present invention, provide reference example.

＜reference example 1, with reference to comparative example 1

Same to what provide among the evaluation method of each sheet-form molded characteristic of (methyl) acrylate copolymer (A), thermally conductive pressure-sensitive adhesive composition and thermal conductivity and the embodiment.Reference example 1, as follows with reference to the new evaluation method that adopts in the comparative example 1.

(9) easy separability

The test film of 50mm * 150mm is attached between the unidimensional aluminium sheet and sheet glass,, placed then 1 hour with the running roller pressing of 2kg.This sample being fixed in the thermostatic bath that is set to 180 ℃, placing 1 hour, is that the scraper plate of 0.5mm inserts in the test film that is attached between aluminium sheet and the sheet glass then immediately with thickness, inserts along its length.At this moment, observe the situation of stripping test sheet.

Zero: radiator element can be peeled off on aluminium sheet and sheet glass simply.Peeling off does not need too big power.

△: radiator element is peeled off from aluminium sheet and sheet glass, needs power but peel off.

*: radiator element can't be peeled off from aluminium sheet and sheet glass.

(10) flame retardant resistance

Test according to UL specification UL94 " machine part with the combustion test method of plastic material ", flame retardant resistance is estimated.With the flaky sample cylinder of packing into, carry out the igniting in 10 seconds, after finishing, flaming combustion carries out the 2nd time igniting in 10 seconds immediately, and the test subject shown in the his-and-hers watches 1 is estimated.Identical sample type is respectively carried out 5 tests, according to its result, and the burning grade separation shown in carry out table 1.

(reference example 1)

Mixing and kneading machine add in the lump in mortar 100 parts with embodiment 1 in same multipolymer (A1) (1), 44.5 parts of monomer mixture (A2m) (1), 1.6 parts of polymerization starter TMCH, 3.0 parts of ethylenebisstearamide and 200 parts of aluminium hydroxides similarly to Example 1 of obtaining as compound (D), with mixing and kneading machine thorough mixing at room temperature.At this moment, aluminium hydroxide is 138 parts with respect to adding up to 100 parts the multipolymer (A1) (1) and the weight ratio of monomer mixture (A2m) (1), and the weight ratio of ethylenebisstearamide is 2.1 parts.Deaeration while stirring under reduced pressure then obtains the aqueous sample of viscosity.Spread the polyester film of band releasing agent in the mould bottom surface of vertical 400mm, horizontal 400mm, dark 2mm, then this sample is filled with mould, thereon the polyester film of cover tape releasing agent.It is taken out from mould, under 130 ℃, the condition of 0.5MPa, carried out polymerization in 30 minutes, obtain the thermal conductivity sheet-form molded (4) that the two sides is coated by the polyester film with releasing agent by pressing with oil press.Levels of residual monomers from sheet is calculated the polymerisation conversion of monomer mixture (A2m), and the result is 99.9%.This thermal conductivity sheet-form molded (4) is carried out the evaluation of each characteristic.The result is as shown in table 3.

(with reference to comparative example 1)

Do not use ethylenebisstearamide, in addition same with reference example 1, obtain the thermal conductivity sheet-form molded (5) that the two sides is coated by the polyester film with releasing agent.This thermal conductivity sheet-form molded (5) is carried out the evaluation of each characteristic.The result is as shown in table 3.

[table 3]

(table 3)

Following as shown in Table 3 content.

In reference example 1, the oxyhydroxide (B) and the compound (D) of multipolymer (A1), monomer mixture (A2m), thermal polymerization (E2), metal are mixed, obtain mixture, under heating, make sheet in the preparation thermally conductive pressure-sensitive adhesive composition, it is sheet-form molded to make thermal conductivity, and the result obtained excellent thermal conductivity, bond strength excellence and to have the thermal conductivity of easy separability under 180 ℃ sheet-form molded in the common use temperature territory.Relative therewith, in the reference comparative example 1 that does not use compound (D), easily separability is poor.

＜reference example 2-5, with reference to comparative example 2-6

Reference example 2-5, as follows with reference to the evaluation method that adopts among the comparative example 2-6.

(1) sheet material smoothness (μ m)

Measure each reference example and each with reference to the sheet-form molded sheet thickness of the thermal conductivity of using in the comparative example with micrometer, every sheet material is measured position, 10 place, calculates the poor of measurement result maximum value and minimum value, with its value as the sheet material smoothness.We can say that the more little then smoothness of sheet material smoothness value in the table 6 is high more.

(2) product width (mm)

Measure each reference example and each with reference to the sheet-form molded width of the thermal conductivity of using in the comparative example with steel ruler (tape measure), every sheet material is measured position, 2 place, with the mean value of the measurement result width as each sheet material.Each reference example and each prescribed value with reference to the sheet-form molded width of the thermal conductivity of using in the comparative example are 250mm, and record is poor with this prescribed value in the table 6.Therefore we can say that the product width value in the table 6 is more little, then the formability of sheet material is high more.

(conventional preparation method)

Following Shuo Ming reference example 2-5 and sheet-form molded according to the preparation of following order with reference to the thermal conductivity for preparing among the comparative example 2-6.

In being controlled at 50 ℃ the twin screw extruder of L/D=48 (equidirectional), internal temperature adds multipolymer (A1), monomer mixture (A2m), aluminium hydroxide, silicon-dioxide (C), polymerization starter, outside cross-linking agent successively, the screw rod revolution is set at 200 rev/mins condition, the running twin screw extruder.When twin screw extruder turns round, make to be vacuum state in the twin screw extruder, promptly the exhaust port pressure of twin screw extruder is 1013hPa, carries out dispersion, the mixing of raw material, obtains thermally conductive pressure-sensitive adhesive composition.Then, the gained thermally conductive pressure-sensitive adhesive composition is poured on the single face organosilicon demoulding oriented polyester film, cover thermally conductive pressure-sensitive adhesive composition with single face organosilicon demoulding oriented polyester film, thickness and the width with this thermally conductive pressure-sensitive adhesive composition is adjusted to 1.0mm and 250mm respectively then.Then, the thermally conductive pressure-sensitive adhesive composition of having regulated thickness and width was kept 30 minutes in internal temperature is controlled at 150 ℃ Mathis stove (Mathis LABCOATER model LET-S (manufacturing of Werner MathisAG company)), obtained reference example of the present invention and sheet-form molded with reference to the thermal conductivity of using in the comparative example.

(reference example 2)

The thermal conductivity of using in this reference example is sheet-form molded to be with respect to the same multipolymer (A1) that obtains among 100 mass parts and the embodiment 1, has used 42.5 mass parts monomer mixtures (A2m) (2), 0.5 mass parts thermal polymerization (E2), 1.0 mass parts silica 1s (C) (1) and 200 mass parts aluminium hydroxides (B) (1), 1.0 mass parts outside cross-linking agents to make.

Here, monomer mixture (A2m) (2) contains 22.5 mass parts n-butyl acrylate monomers, 15.0 mass parts 2-EHA monomers, 5.0 mass parts methacrylic acids, thermal polymerization (E2) is 1, two (tert-butyl peroxide)-3 of 1-, 3,5-trimethylcyclohexanone, silica 1 (C) (1) are that (AEROSIL is the registered trademark of デ グ サ company to the AEROSIL200 shown in the table 3.Below too), outside cross-linking agent is a pentaerythritol triacrylate.

As shown in table 6, use the sheet-form molded sheet material characteristic of thermal conductivity in this reference example of above feedstock production to be: the value of sheet material smoothness is 13 μ m, and the product width value is+4mm.Therefore, the value of the sheet material smoothness that the thermal conductivity of using in this reference example is sheet-form molded is lower than 20 μ m, and the product width value is lower than+10mm, therefore has high sheet material smoothness and high formability.

As shown in table 5, the hydrophobic rate that the silica 1 that uses in this reference example (C) (1) is measured by the transmissivity method is 8%, and the one-level median size is 12nm, therefore has sheet material smoothness the highest in the reference example.Therefore as can be known: in order to obtain high sheet material smoothness, the hydrophobic rate that use is measured by the transmissivity method is that the silicon-dioxide (C) below 10% is effective.

(with reference to comparative example 2)

Except that do not use silica 1 (C) (1), this prepares with kind and with the raw material of amount with reference to sheet-form molded being to use with reference example 2 of the thermal conductivity of using in the comparative example.This does not only use silica 1 (C) (1) with reference in the comparative example, and does not use silicon-dioxide itself, and therefore as shown in table 6, the sheet-form molded sheet material characteristic of thermal conductivity is: the value of sheet material smoothness is 95 μ m, and the product width value is+20mm.That is, the value of sheet material smoothness and product width the value all value than reference example 2 are big, and the value of sheet material smoothness surpasses 20 μ m, and product width surpasses+10mm simultaneously, and sheet material smoothness and formability all reduce.Therefore, in order to obtain high sheet material smoothness and high-mouldability, it is effective using silicon-dioxide (C).

(reference example 3)

The thermal conductivity of using in this reference example is sheet-form molded except the usage quantity of silica 1 (C) (1), and other adopt with reference example 2 and prepare with kind and with the raw material of measuring, and the usage quantity of silica 1 (C) (1) is 0.5 mass parts.In this reference example, use 0.5 mass parts silica 1 (C) (1), be half of the silica 1 in the reference example 2 (C) (1) usage quantity, so the value of sheet material smoothness is 15 μ m, the product width value is+6mm that the value of sheet material smoothness and the product width all value than reference example 2 is big.But the value of sheet material smoothness is lower than 20 μ m in this reference example, and the product width value is lower than+10mm, even therefore silica 1 (C) (1) usage quantity is 0.5 mass parts, in the quality that still can have appropriateness aspect sheet material smoothness and the formability two.

(with reference to comparative example 3)

This is sheet-form molded with reference to the thermal conductivity of using in the comparative example, use the silica 1 (C) (1) of 1.0 mass parts of using in silicon-dioxide 3 (C) (3) the replacement reference example 2 of 1.0 mass parts, in addition, employing prepares with kind and with the raw material of measuring with reference example 2.As shown in table 5, this is AEROSILR972 with reference to the silicon-dioxide 3 (C) (3) that uses in the comparative example, and the hydrophobic rate that this silicon-dioxide 3 (C) (3) is measured by the transmissivity method surpasses 50%, is 55%.This surpasses 50% silicon-dioxide 3 (C) (3) with reference to the sheet-form molded hydrophobic rate of measuring by the transmissivity method of having used of the thermal conductivity of using in the comparative example, so its sheet material characteristic is: the value of sheet material smoothness is 98 μ m, and the product width value is+20mm.That is, the value of sheet material smoothness and the product width all value than reference example 2 is big, and the value of sheet material smoothness surpasses 20 μ m, and the value of product width surpasses+10mm simultaneously, and sheet material smoothness and formability all reduce.Therefore in order to obtain high sheet material smoothness and high-mouldability, the hydrophobic rate that use is measured by the transmissivity method is that the silicon-dioxide (C) below 50% is effective.

(reference example 4)

The thermal conductivity of using in this reference example is sheet-form molded, uses the 1.0 mass parts silica 1s (C) (1) that use in 1.0 mass parts silicon-dioxide 2 (C) (2) the replacement reference example 2, in addition adopts with reference example 2 to prepare with kind and with the raw material of measuring.As shown in table 5, the silicon-dioxide 2 (C) (2) that uses in this reference example is AEROSIL200V, and the hydrophobic rate that this silicon-dioxide 2 (C) (2) is measured by the transmissivity method is below 10%, is 8%.The thermal conductivity of using in this reference example is sheet-form molded, and to have used the hydrophobic rate of measuring by the transmissivity method be silicon-dioxide 2 (C) (2) below 50%, so its sheet material characteristic is as shown in table 6: the sheet material smoothness is 13 μ m, and product width is+3mm.That is, the value of sheet material smoothness is lower than 20 μ m, and simultaneously the value of product width is lower than+10mm, so the thermal conductivity of using in this reference example is sheet-form molded has high sheet material smoothness and a high-mouldability.

(with reference to comparative example 4)

This is sheet-form molded with reference to the thermal conductivity of using in the comparative example, use 1.0 mass parts silicon-dioxide 4 (C) (4) to replace the silica 1 (C) (1) of 1.0 mass parts of use in the reference example 2, in addition, employing prepares with kind and with the raw material of measuring with reference example 2.As shown in table 5, this is AEROSILR805 with reference to the silicon-dioxide 4 (C) (4) that uses in the comparative example, and the hydrophobic rate that this silicon-dioxide 4 (C) (4) is measured by the transmissivity method surpasses 50%, is 60%.This surpasses 50% silicon-dioxide 4 (C) (4) with reference to the sheet-form molded hydrophobic rate of measuring by the transmissivity method of having used of the thermal conductivity of using in the comparative example, therefore its sheet material characteristic is: the sheet material smoothness is 100 μ m, the product width value is+20mm, with to use the hydrophobic rate of measuring by the transmissivity method to surpass the situation of reference comparative example 3 of 50% silicon-dioxide 3 (C) (3) same, the value of sheet material smoothness surpasses 20 μ m, the value of product width surpasses+10mm simultaneously, and sheet material smoothness and formability all reduce.Therefore in order to obtain high sheet material smoothness and high-mouldability, the hydrophobic rate that use is measured by the transmissivity method is that the silicon-dioxide (C) below 50% is effective.

(reference example 5)

The thermal conductivity of using in this reference example is sheet-form molded, uses the 1.0 mass parts silica 1s (C) (1) that use in 0.5 mass parts silicon-dioxide 2 (C) (2) the replacement reference example 2, in addition adopts with reference example 2 to prepare with kind and with the raw material of measuring.As shown in table 5, use the silicon-dioxide 2 (C) (2) same with reference example 4 in this reference example, so its sheet material characteristic is as shown in table 6: the sheet material smoothness is 19 μ m, and product width is+3mm, the value of the value of product width and reference example 4 is same, but the value of sheet material smoothness is bigger than the value of reference example 4.But the value of the sheet material smoothness in this reference example is lower than 20 μ m, and the value of product width is lower than+10mm, therefore, even the consumption of silicon-dioxide 2 (C) (2) is 0.5 mass parts, also can have suitable quality aspect sheet material smoothness and the formability two.

(with reference to comparative example 5)

This is sheet-form molded with reference to the thermal conductivity of using in the comparative example, use 0.5 mass parts silicon-dioxide 3 (C) (3) and 0.5 mass parts silicon-dioxide 4 (C) (4) to replace the silica 1 (C) (1) of 1.0 mass parts of use in the reference example 2, in addition, employing prepares with kind and with the raw material of measuring with reference example 2.As shown in table 5, this hydrophobic rate of measuring by the transmissivity method with reference to the silicon-dioxide 3 (C) (3) that uses in the comparative example and silicon-dioxide 4 (C) (4) is respectively 55% and 60%, has all surpassed 50%.Therefore as shown in table 6, this with reference to the sheet-form molded sheet material characteristic of the thermal conductivity of using in the comparative example is: the sheet material smoothness is 102 μ m, and the product width value is+21mm that the value of sheet material smoothness surpasses 20 μ m, the value of product width surpasses+10mm simultaneously, and sheet material smoothness and formability all reduce.Therefore as can be known: will use with reference to comparative example 3 or with reference to each meromict of the consumption in the comparative example 4 even the hydrophobic rate of measuring by the transmissivity method surpasses 50% silicon-dioxide, and can not obtain high sheet material smoothness and high-mouldability.

(with reference to comparative example 6)

This is with reference to the sheet-form molded silica 1 (C) (1) that is to use 1.0 mass parts silicon-dioxide 5 (C) (5) to replace 1.0 mass parts of use in the reference example 2 of the thermal conductivity of using in the comparative example, in addition, employing prepares with kind and with the raw material of measuring with reference example 2.As shown in table 5, this is AEROSILR50 with reference to the silicon-dioxide 5 (C) (5) that uses in the comparative example, and the median size of the primary granule in this silicon-dioxide 5 (C) (5) is about 30nm.The silicon-dioxide 5 (C) (5) that this has described median size with reference to the sheet-form molded use of the thermal conductivity of using in the comparative example, so its sheet material characteristic is as shown in table 6: the sheet material smoothness is 19 μ m, is lower than 20 μ m, and the product width value is+19mm to surpass+10mm.Promptly, use the median size of primary granule to surpass 20nm-possess high sheet material smoothness with reference to the thermal conductivity in the comparative example is sheet-form molded for this of the silicon-dioxide 5 (C) (5) of about 30nm, simultaneously sheet-form molded flowability suppresses function and reduces insufficient formability.In order to obtain high smoothness and high-mouldability simultaneously, the median size of primary granule is necessary for below the 20nm.Therefore, for satisfying described condition, the median size of the primary granule of the silicon-dioxide that uses among the present invention (C) is necessary for below the 20nm.

For above-mentioned reference example 2-5 and with reference to the mixture among the comparative example 2-6, the quality summary sheet of each mixture is shown in the table 4 in the time of will being 100 mass parts with the combined amount of mixture A1.

[table 4]

Above-mentioned reference example 2-5 and as shown in table 5 with reference to the characteristic of the silicon-dioxide that uses as raw material among the comparative example 2-6.

[table 5]

To above-mentioned reference example 2-5 and as shown in table 6 with reference to the evaluation of the sheet-form molded sheet material characteristic of the thermal conductivity for preparing among the comparative example 2-6.

[table 6]

Claims (13)

1. thermally conductive pressure-sensitive adhesive composition is characterized in that: have the oxyhydroxide (B) of 100 mass parts (methyl) acrylate copolymers (A) and 70-170 mass parts metal, above-mentioned (methyl) acrylate copolymer (A) foaming; Wherein said (methyl) acrylate copolymer (A) is in the presence of 100 mass parts multipolymers (A1), 5-70 mass parts monomer mixture (A2m) polymerization is obtained, described multipolymer (A1) is to be 100% quality with whole multipolymers (A1), contains the 80-99.9% quality and forms second-order transition temperature (methyl) acrylate monomeric units (a1) for the homopolymer below-20 ℃, the 0.1-20% quality has the monomeric unit (a2) of organic acidic group, the 0-10% quality has the monomeric unit (a3) of the functional group beyond organic acidic group, and the 0-10% quality can constitute with the monomeric unit (a4) of their copolymerization; Described monomer mixture (A2m) is to be 100% quality with whole monomer mixtures (A2m), contains the 40-100% quality and forms second-order transition temperature and can constitute with the monomer (a7m) of their copolymerization for (methyl) acrylate monomer (a5m) of the homopolymer below-20 ℃, monomer (a6m) that the 60-0% quality has organic acidic group and 0-20% quality.

2. the thermally conductive pressure-sensitive adhesive composition of claim 1, wherein expansion ratio be 1.05-1.4 doubly.

3. the thermally conductive pressure-sensitive adhesive composition of claim 1, said composition further contains 0.1-5 mass parts silicon-dioxide (C), and the median size of the primary granule of this silicon-dioxide (C) is that 5-20nm and the hydrophobic rate measured by the transmissivity method are below 50%.

4. the thermally conductive pressure-sensitive adhesive composition of claim 1, it is that 120-200 ℃ and molecular weight are lower than 1000 compound (D) that said composition further contains 0.05-10 mass parts fusing point, described compound (D) is an aliphatic amide compound.

5. the thermally conductive pressure-sensitive adhesive composition of claim 1, wherein the oxyhydroxide of above-mentioned metal (B) is aluminium hydroxide.

6. thermally conductive sheet-form molded foam, this thermally conductive sheet-form molded foam is formed by the thermally conductive pressure-sensitive adhesive composition of claim 1.

7. the layer of the thermally conductive pressure-sensitive adhesive composition of the claim 1 that thermally conductive sheet-form molded foam, this thermally conductive sheet-form molded foam contain base material, form on the one or both sides of this base material.

8. the manufacture method of thermally conductive sheet-form molded foam, this method has following steps: the step of mixing formation mixture (F) for the metal hydroxides (B) of 70-170 mass parts for the thermal polymerization (E2) of 0.1-50 mass parts, with respect to multipolymer (A1) that adds up to 100 mass parts and monomer mixture (A2m) with 100 mass parts multipolymers (A1), 5-70 mass parts monomer mixture (A2m), with respect to 100 mass parts monomer mixtures (A2m);

Make the step of mixture (F) foaming;

The step of heated mixt (F);

And the step that makes mixture (F) sheetization;

Wherein said multipolymer (A1) is to be 100% quality with whole multipolymers (A1), contains the 80-99.9% quality and forms second-order transition temperature the monomeric unit (a3) of organic acidic group functional group in addition and 0-10% quality can constitute with the monomeric unit (a4) of their copolymerization for (methyl) acrylate monomeric units (a1) of the homopolymer below-20 ℃, monomeric unit (a2), 0-10% quality that the 0.1-20% quality has organic acidic group contain; Monomer mixture (A2m) is to be 100% quality with whole monomer mixtures (A2m), contains the 40-100% quality and forms second-order transition temperature and can constitute with the monomer (a7m) of their copolymerization for (methyl) acrylate monomer (a5m) of the homopolymer below-20 ℃, monomer (a6m) that the 0-60% quality has organic acidic group and 0-20% quality.

9. the manufacture method of the thermally conductive sheet-form molded foam of claim 8, the wherein above-mentioned step of mixture (F) foaming that makes is for to make mixture (F) with 1.05 times of-1.4 times of steps that foam of expansion ratio.

10. the manufacture method of the thermally conductive sheet-form molded foam of claim 9, wherein said mixture (F) is with respect to multipolymer (A1) that adds up to 100 mass parts and monomer mixture (A2m), further be mixed with the silicon-dioxide (C) of 0.1-5 mass parts, the median size of the primary granule of this silicon-dioxide (C) is 5-20nm and is below 50% by the hydrophobic rate that the transmissivity method is measured.

11. the manufacture method of the thermally conductive sheet-form molded foam of claim 9, wherein said mixture (F) is with respect to multipolymer (A1) that adds up to 100 mass parts and monomer mixture (A2m), further mix 0.05-10 mass parts fusing point and be 120-200 ℃ and molecular weight and be lower than the mixture (G) that 1000 compound (D) constitutes, described compound (D) is an aliphatic amide compound.

12. the manufacture method of the thermally conductive sheet-form molded foam of claim 11, wherein said mixture (G) is with respect to multipolymer (A1) that adds up to 100 mass parts and monomer mixture (A2m), the mixture that further mixes the silicon-dioxide (C) of 0.1-5 mass parts and constitute, the median size of the primary granule of this silicon-dioxide (C) are that 5-20nm and the hydrophobic rate measured by the transmissivity method are below 50%.

13. the manufacture method of the thermally conductive sheet-form molded foam of claim 8, wherein the oxyhydroxide of above-mentioned metal (B) is aluminium hydroxide.

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