JP2012188507A - Composition for heat dissipation sheet and heat dissipation sheet formed by curing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fast curing composition for a heat dissipation sheet and a heat dissipation sheet having good thermal conductivity and high productivity.SOLUTION: The composition for a heat dissipation sheet contains a polyoxyalkylene polymer (A) having, per molecule, an average of one or more substituents represented by general formula (1):-Z-C(=O)-C(R)=CH(wherein Ris H or a 1-20C hydrocarbon group, and Z is a divalent organic group), and having a number average molecular weight of ≥3,000, an initiator (B), and a thermally conductive filler (C).

Description

  The present invention relates to a heat radiating sheet composition and a heat radiating sheet obtained by curing the composition. More specifically, the present invention relates to a heat radiating sheet composition containing a polyoxyalkylene polymer having a (meth) acryloyl group, an initiator, and a heat conductive filler, and a heat radiating sheet.

  Conventionally, heat-conductive materials having rubber elasticity have been widely used as heat dissipation and heat transfer spacers for electronic parts such as various heaters and temperature sensors, as well as semiconductors such as transistors, diodes, and ICs. As such a heat conductive material, for example, a material in which a heat conductive filler is blended with a base rubber such as silicone rubber or EPDM rubber is known (for example, Patent Document 1). Techniques for this are disclosed. Moreover, what uses silicone rubber is the best known, and the technique by the combination of various heat conductive fillers and silicone rubber is disclosed (for example, patent documents 2-4).

  In such a material for heat conduction, not only the heat conductivity of the material itself but also the adhesion to the base material is important. For adhesion to the substrate, adhesion to the substrate surface, substrate shape, and followability to deformation are important. A material having rubber elasticity is suitable in the latter aspect. In addition, with regard to the former, except for the case of an irregular shaped adhesive, etc., in the case of a fixed form such as a sheet or tape, the adhesiveness or adhesion layer can be separately provided, or the adhesiveness can be increased by expressing surface tackiness. Secured.

  However, in a heat conductive material, in order to increase the heat conductivity, a high amount of heat conductive filler is usually filled. However, the higher the filler is filled, the more the elasticity of the material itself is lost and the surface tackiness is also reduced. As a result, there is a problem that the adhesion to the substrate is impaired. On the other hand, the method of providing the adhesive layer and the pressure-sensitive adhesive layer is an effective method with little influence on the surface property of the material itself, but there is a problem that the process of newly forming those layers is required and the productivity is poor. is there.

  On the other hand, based on a hydrolyzable silyl group-containing compound having a hydrolyzable silyl group such as polyalkylene glycol or polyisobutylene, a compound containing a heat conductive filler has a resin composition having both excellent strength and adhesion It is disclosed that it is a thing (for example, patent document 5). However, the method for controlling adhesion is not particularly shown, and since the curing type is a moisture curing type, curing curing requires several hours or more, so that there is a problem that productivity is inferior.

JP 2001-139733 A Japanese Patent Publication No. 6-55891 Japanese Examined Patent Publication No. 6-38460 Japanese Patent Publication No. 7-91468 JP 2001-302936 A

  It is an object of the present invention to provide a fast-curing heat radiation sheet composition and a heat radiation sheet having good thermal conductivity and high productivity.

  As a result of intensive studies to solve the above problems, the present inventors have found the following and completed the present invention.

That is, the present invention
(I)
General formula (1):
^{-Z-C (= O) -C} (R 1) = CH 2 (1)
(Wherein R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and Z is a divalent organic group.) A number average having one or more substituents in the molecule on average. A heat radiating sheet composition comprising a polyoxyalkylene polymer (A) having a molecular weight of 3,000 or more, an initiator (B), and a heat conductive filler (C).

(II)
The composition for heat radiating sheets according to (I), wherein Z in the general formula (1) is an oxygen atom.

(III)
Z in the general formula (1) is the general formula (2):
—NH—C (═O) —O—R ² —O— (2)
(Wherein, R ² is a divalent hydrocarbon group.) Is a group represented by the heat dissipation sheet composition according to (I).

(IV)
Z in the general formula (1) is the general formula (3):
—O—C (═O) —NH—R ² —O— (3)
(Wherein, R ² is the same. As defined above) radiation sheet composition according to a group represented by (I).

(V)
The polyoxyalkylene polymer (a) in which the substituent represented by the general formula (1) has a hydroxyl group and the general formula (4):
^{O = C = N-R 2} -O-C (= O) -C (R 1) = CH 2 (4)
(Wherein R ¹ and R ² are the same as described above) (IV) obtained by reacting the isocyanate compound (D) represented in the presence of dibutyltin (mercapto ester) (E). The composition for heat dissipation sheets of description.

(VI)
The composition for heat dissipation sheets according to any one of (I) to (V), wherein R ¹ is a hydrogen atom.

(VII)
The composition for heat dissipation sheets according to any one of (III) to (VI), wherein R ² is an ethylene group.

(VIII)
The composition for heat dissipation sheets according to any one of (I) to (VII), wherein the polyoxyalkylene polymer (A) is a polyoxypropylene polymer.

(IX)
The composition for heat dissipation sheets according to any one of (I) to (VIII), which contains a monomer and / or oligomer having a radical polymerizable substituent.

(X)
The composition for heat dissipation sheets according to any one of (I) to (IX), which contains a monomer and / or oligomer having an anionically polymerizable substituent.

(XI)
The composition for heat dissipation sheets according to any one of (I) to (X), comprising a monomer and / or oligomer having a (meth) acryloyl group.

(XII)
The composition for heat-radiating sheets according to (XI), further comprising a monomer and / or oligomer having a (meth) acryloyl group and having a number average molecular weight of 5,000 or less.

(XIII)
The composition for heat dissipation sheets according to any one of (I) to (XII), wherein the initiator (B) is a photopolymerization initiator and / or a thermal polymerization initiator.

(XIV)
The composition for heat-radiating sheets according to any one of (I) to (XII), wherein the initiator (B) is a redox initiator.

(XV)
From (I), the thermally conductive filler (C) is at least one selected from metal oxide, metal nitride, metal carbide, metal hydroxide, crystalline silica, organic polymer fired product, and nitrogen carbide. The composition for heat dissipation sheets of any one of (XIV).

(XVI)
The heat radiating sheet composition according to (XV), wherein the thermally conductive filler (C) is at least one selected from aluminum oxide, boron nitride, aluminum nitride, and aluminum hydroxide.

(XVII)
The composition for a heat radiation sheet according to any one of (I) to (XVI), wherein the volume ratio of the heat conductive filler (C) is 25% by volume or more in the total composition.

(XVIII)
The composition for heat dissipation sheets of any one of (I) to (XVII) containing the organic carboxylic acid compound (F).

(XIX)
The composition for heat dissipation sheets as described in (XVIII), wherein the organic carboxylic acid compound (F) is a stearic acid compound.

(XX)
The composition for heat radiating sheets according to (XIX), wherein the organic carboxylic acid compound (F) is a stearic acid metal salt.

(XXI)
The composition for heat-radiating sheets according to (XX), wherein the organic carboxylic acid compound (F) is at least one selected from lead stearate, zinc stearate, and calcium stearate.

(XXII)
A heat radiation sheet obtained by curing the composition for heat radiation sheet according to any one of (I) to (XXI).

  Since the composition for heat radiating sheets of the present invention has a high curing rate, the productivity of the heat radiating sheets is high, and the obtained heat radiating sheets exhibit excellent thermal conductivity.

  The present invention will be described in detail below.

The composition for a heat dissipation sheet of the present invention has the general formula (1):
^{-Z-C (= O) -C} (R 1) = CH 2 (1)
Wherein R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and Z is a divalent organic group (hereinafter referred to as a (meth) acryloyl-based substituent). A polyoxyalkylene polymer (A) having a number average molecular weight of at least 3,000 in the molecule and having a number average molecular weight of 3,000 or more.

  The number of (meth) acryloyl-based substituents in the polymer (A) is not particularly limited, but the curability is lowered when the average is less than 1 per molecule from the viewpoint that the polymers (A) are crosslinked with each other. Since there exists a tendency, an average of 1 or more is preferable. However, if the polymer (A) having one or more (meth) acryloyl substituents on average per molecule is included, the average of less than one per molecule is required to adjust the hardness and flexibility of the cured product. A polyoxyalkylene polymer having a (meth) acryloyl substituent may be included. Further, the (meth) acryloyl group may be present at any of the side chain and / or the terminal of the molecule, but is preferably present at the terminal of the molecule from the viewpoint of rubber elasticity.

R ¹ in the general formula (1) represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. R ¹ is not particularly limited, and examples thereof include a hydrogen atom; an alkyl group such as a methyl group and an ethyl group; a cycloalkyl group such as a cyclohexyl group; an aryl group such as a phenyl group; and an aralkyl group such as a benzyl group. In these, a methyl group or a hydrogen atom is preferable from the high reactivity of a polyoxyalkylene type polymer (A), and a hydrogen atom is more preferable.

Z in the general formula (1) is not particularly limited, and examples thereof include an oxygen atom; a sulfur atom; and an amino group such as —NH— and —NCH ₃ —. Among these, in view of ease of introduction, an oxygen atom, —NH— group, and a group represented by the following general formula (2) and general formula (3) are preferable, and an oxygen atom, general formula (2), general A group represented by the formula (3) is more preferable.
—NH—C (═O) —O—R ² —O— (2)
(In the formula, R ² is a divalent hydrocarbon group.)
—O—C (═O) —NH—R ² —O— (3)
(In the formula, R ² is the same as above.)
R ² in the general formulas (2) and (3) is not particularly limited as long as it is a divalent hydrocarbon group. For example, an alkylene group such as a methylene group, an ethylene group, a propylene group, or a hexylene group; a cyclobutylene group Cycloalkylene groups such as cyclopentylene group and cyclohexylene group; arylene groups such as phenylene group and benzylene group; Among these, ethylene group and hexylene group are preferable and ethylene group is more preferable because of easy introduction.

  Examples of the method for introducing the (meth) acryloyl substituent represented by the general formula (1) into the polyoxyalkylene polymer include (a) a polyoxyalkylene polymer (a) having a hydroxyl group, A method of reacting the compound (G1) having a functional group and an unsaturated group which are reactive with respect to the hydroxyl group, (b) replacing the hydroxyl group of the polyoxyalkylene polymer (a) with another functional group, Examples thereof include a method of reacting a compound (G2) having a functional group and an unsaturated group that are reactive to a substituent.

  Examples of the compound (G1) to be reacted with the hydroxyl group of the polyoxyalkylene polymer (a) by the method (a) include unsaturated acid halogens such as chloro (meth) acrylic acid and bromated (meth) acrylic acid. Compounds; Carboxylic acid compounds such as (meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, (meth) acrylic acid n-butyl, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acrylic acid n-heptyl, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, (meth ) Decyl acrylate, dodecyl (meth) acrylate, phenyl (meth) acrylate, toluyl (meth) acrylate, benzyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 3- (meth) acrylic acid 3- Methoxybutyl, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, stearyl (meth) acrylate, trifluoromethylmethyl (meth) acrylate, 2-trifluoromethyl (meth) acrylate Ethyl, 2-perfluoroethylethyl (meth) acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth) acrylate, perfluoroethyl (meth) acrylate, trifluoromethyl (meth) acrylate, Bis (trifluoromethyl) methyl (meth) acrylate, (meth ) 2-trifluoromethyl-2-perfluoroethylethyl acrylate, 2-perfluorohexylethyl (meth) acrylate, 2-perfluorodecylethyl (meth) acrylate, 2-perfluorohexa (meth) acrylate Examples include ester compounds such as decylethyl. Among these, from the reactivity with the hydroxyl group of the polymer (a), among the unsaturated acid halogen compounds, chlorinated (meth) acrylic acid is preferred, and among the carboxylic acid compounds, (meth) acrylic acid is preferred. Among the ester compounds, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, (meth ) Isobutyl acrylate and tert-butyl (meth) acrylate are preferred.

  The amount of the compound (G1) to be reacted with the hydroxyl group of the polymer (a) is preferably from 0.1 molar equivalent to 10 molar equivalent, more preferably from 0.5 molar equivalent to 5 molar equivalent based on the hydroxyl group. When the amount used is less than 0.1 molar equivalent, the reactivity may decrease, and when it is larger than 10 molar equivalent, it may be economically disadvantageous.

  In the reaction of the polymer (a) and the compound (G1), various additives (H) can be used.

  When the hydroxyl group of the polymer (a) is reacted with unsaturated acid halogen compounds, an amine compound or the like can be used as an additive (H1) for the purpose of capturing the generated acid. Examples of the amine compound include aliphatic tertiary amines such as triethylamine, triamylamine, trihexylamine, and trioctylamine; aliphatic unsaturated amines such as triallylamine and oleylamine; aniline, laurylaniline, and stearylaniline. , Aromatic amines such as triphenylamine; pyridine, 2-aminopyridine, 2- (dimethylamino) pyridine, 4- (dimethylaminopyridine), 2-hydroxypyridine, imidazole, 2-ethyl-4-methylimidazole, Morpholine, N-methylmorpholine, piperidine, 2-piperidinemethanol, 2- (2-piperidino) ethanol, piperidone, 1,2-dimethyl-1,4,5,6-tetrahydropyrimidine, 1,8-diazabicyclo (5 4,0) Unde -7 (DBU), 6- (dibutylamino) -1,8-diazabicyclo (5,4,0) undecene-7 (DBA-DBU), 1,5-diazabicyclo (4,3,0) nonene-5 (DBN), 1,4-diazabicyclo (2,2,2) octane (DABCO), nitrogen-containing heterocyclic compounds such as aziridine, and other amines include ethylenediamine, propylenediamine, hexamethylenediamine, N- Methyl-1,3-propanediamine, N, N′-dimethyl-1,3-propanediamine, diethylenetriamine, triethylenetetramine, benzylamine, 3-methoxypropylamine, 3-lauryloxypropylamine, 3-dimethylaminopropyl Amine, 3-diethylaminopropylamine, 3-dibutylaminopropylamine , 3-morpholinopropylamine, 2- (1-piperazinyl) ethylamine, xylylenediamine and other amines; guanidines such as guanidine, phenylguanidine and diphenylguanidine; butylbiguanide, 1-o-tolylbiguanide and 1-phenyl And biguanides such as biguanides. Among these, tertiary amines are preferable from the viewpoint of reactivity, and triethylamine is preferable from the viewpoint of ease of removal after the reaction and availability.

  The use amount of the additive (H1) such as an amine compound is preferably 0.1 molar equivalent to 10 molar equivalent, and preferably 0.5 molar equivalent to 5 molar equivalent based on the hydroxyl group. When the amount used is less than 0.1 molar equivalent, the acid may not be sufficiently captured, and when it is larger than 10 molar equivalent, removal may be difficult.

  When the hydroxyl group of the polymer (a) is reacted with the carboxylic acid compound, it is reactive when a protonic acid and Lewis acid, a salt of an amine compound and a sulfonic acid, a salt of a phosphorus compound and a sulfonic acid, etc. are used in combination as an additive (H2). May be higher. Examples of such additives (H2) include inorganic acids such as hydrochloric acid, odorous acid, iodic acid, and phosphoric acid; acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, Capric acid, undecanoic acid, lauric acid, tridecylic acid, myristic acid, pentadecylic acid, palmitic acid, heptadecylic acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid, serotic acid, montanic acid, melicic acid, lactelic acid Linear saturated fatty acids such as: undecylenic acid, Lindellic acid, Tuzic acid, Fizeteric acid, myristoleic acid, 2-hexadecenoic acid, 6-hexadecenoic acid, 7-hexadecenoic acid, palmitoleic acid, petrothelic acid, oleic acid, elaidin Acid, asclepic acid, vaccenic acid, gadoleic acid, gondoic acid, cetate Mono-unsaturated fatty acids such as inic acid, erucic acid, brassic acid, ceracoleic acid, ximenic acid, lumenic acid, acrylic acid, methacrylic acid, angelic acid, crotonic acid, isocrotonic acid, 10-undecenoic acid; Acid, 10,12-octadecadienoic acid, hiragoic acid, α-eleostearic acid, β-eleostearic acid, punicic acid, linolenic acid, 8,11,14-eicosatrienoic acid, 7,10,13 -Docosatrienoic acid, 4,8,11,14-hexadecatetraenoic acid, moloctic acid, stearidonic acid, arachidonic acid, 8,12,16,19-docosatetraenoic acid, 4,8,12,15,18- Polyene unsaturated fatty acids such as eicosapentaenoic acid, sardine acid, nisic acid, docosahexaenoic acid; 2-methylbutyric acid, iso Acid, 2-ethylbutyric acid, pivalic acid, 2,2-dimethylbutyric acid, 2-ethyl-2-methylbutyric acid, 2,2-diethylbutyric acid, 2-phenylbutyric acid, isovaleric acid, 2,2-dimethylvaleric acid, 2-ethyl-2-methylvaleric acid, 2,2-diethylvaleric acid, 2-ethylhexanoic acid, 2,2-dimethylhexanoic acid, 2,2-diethylhexanoic acid, 2,2-dimethyloctanoic acid, 2- Branched fatty acids such as ethyl-2,5-dimethylhexanoic acid, versatic acid, neodecanoic acid, tuberculostearic acid; propiolic acid, taliphosphoric acid, stearolic acid, crepenic acid, xymenic acid, 7-hexadesinic acid, etc. Fatty acids having a triple bond; naphthenic acid, malvalic acid, sterlic acid, hydnocalpsic acid, sorghumulinic acid, gorlic acid, 1-methylcyclopene Cyclohexane, 1-methylcyclohexanecarboxylic acid, 1-adamantanecarboxylic acid, bicyclo [2.2.2] octane-1-carboxylic acid, bicyclo [2.2.1] heptane-1-carboxylic acid and the like Carboxylic acids: acetoacetic acid, ethoxyacetic acid, glyoxylic acid, glycolic acid, gluconic acid, sabinic acid, 2-hydroxytetradecanoic acid, iprolic acid, 2-hydroxyhexadecanoic acid, yarapinolic acid, uniperic acid, ambrettlic acid, aleurit acid 2-hydroxyoctadecanoic acid, 12-hydroxyoctadecanoic acid, 18-hydroxyoctadecanoic acid, 9,10-dihydroxyoctadecanoic acid, 2,2-dimethyl-3-hydroxypropionic acid ricinoleic acid, camlorenic acid, ricanoic acid, ferronic acid, Including cerebronic acid Oxygen fatty acids; halogen substitution products of monocarboxylic acids such as chloroacetic acid, 2-chloroacrylic acid and chlorobenzoic acid; adipic acid, azelaic acid, pimelic acid, suberic acid, sebacic acid, glutaric acid, oxalic acid, malonic acid, Linear dicarboxylic acids such as ethylmalonic acid, dimethylmalonic acid, ethylmethylmalonic acid, diethylmalonic acid, succinic acid, 2,2-dimethylsuccinic acid, 2,2-diethylsuccinic acid, 2,2-dimethylglutaric acid; Saturated dicarboxylic acids such as 1,2,2-trimethyl-1,3-cyclopentanedicarboxylic acid and oxydiacetic acid; unsaturated dicarboxylic acids such as maleic acid, fumaric acid, acetylenedicarboxylic acid and itaconic acid; aconitic acid and citric acid , Isotric acid, 3-methylisocitric acid, 4,4-dimethylaconitic acid, etc. Acids; benzoic acid, 9-anthracenecarboxylic acid, atrolactic acid, anisic acid, isopropylbenzoic acid, salicylic acid, toluic acid, and other aromatic monocarboxylic acids; Aromatic polycarboxylic acids such as acids; amino acids such as alanine, leucine, threonine, aspartic acid, glutamic acid, arginine, cysteine, methionine, phenylalanine, tryptophan, histidine; sulfonic acids such as trifluoromethanesulfonic acid and p-toluenesulfonic acid; Examples include salts of dimesitylamine and pentafluorobenzenesulfonic acid, salts of diphenylamine and trifluoromethanesulfonic acid, and salts of triphenylphosphine and trifluoromethanesulfonic acid.

  The additive (H2) may or may not be used, but when used, it is preferably used in an amount of 0.001 to 10 molar equivalents relative to the hydroxyl group, and 0.01 to 1 molar equivalents. A molar equivalent is more preferred. When the amount used is less than 0.001 molar equivalent, a sufficient effect may not be obtained, and when it is larger than 10 molar equivalent, removal may be difficult.

  In the method (b), examples of the polyoxyalkylene polymer having a substituent other than a hydroxyl group include a polymer having an alkoxide group, a polymer having a halogen atom, and a polymer having an amino group.

  Examples of the method for producing a polyoxyalkylene polymer having an alkoxide group include a method of reacting the polymer (a) with a metal alkoxide. Examples of the metal alkoxide used include sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide, potassium tert-butoxide, calcium diethoxide and the like.

  Furthermore, examples of the method for producing a polyoxyalkylene polymer having an alkoxide group include a method of reacting a polyoxyalkylene polymer (a) with a Grignard reagent (I). The Grignard reagent (I) is not particularly limited, and examples thereof include p-xylene-magnesium bromide, p-xylene-magnesium chloride, allylmagnesium bromide, allylmagnesium chloride, phenylmagnesium bromide, phenylmagnesium chloride, phenylmagnesium iodide, Trimethylsilylmethylmagnesium chloride, vinylmagnesium bromide; benzylmagnesium halides such as benzylmagnesium bromide and benzylmagnesium chloride; tolylmagnesium halides such as m-tolylmagnesium bromide, o-tolylmagnesium bromide, p-tolylmagnesium bromide; butylmagnesium chloride, ethyl Magnesium bromide, ethyl magnesium chloride, hept Magnesium bromide, hexyl magnesium bromide, isobutyl magnesium bromide, isopropyl magnesium bromide, isopropyl magnesium chloride, methyl magnesium bromide, methyl magnesium iodide, n-octyl magnesium bromide, pentadecyl magnesium bromide, pentyl magnesium bromide, propyl magnesium bromide, sec-butyl Alkyl magnesium halides such as magnesium bromide and tert-butylmagnesium chloride; cycloalkyl magnesium halides such as cyclohexyl magnesium bromide, cyclopentyl magnesium bromide and cyclopropyl magnesium bromide; Of these, benzylmagnesium halide, tolylmagnesium halide, alkylmagnesium halide, and cycloalkylmagnesium halide are preferred from the viewpoint of availability. Specifically, benzylmagnesium bromide and benzylmagnesium are preferred from the viewpoint of by-products generated by the reaction. Benzylmagnesium halides such as chloride, m-tolylmagnesium bromide, o-tolylmagnesium bromide, p-tolylmagnesium bromide and other tolylmagnesium halides, heptylmagnesium bromide, hexylmagnesium bromide, n-octylmagnesium bromide and other alkylmagnesium halides, cyclohexyl Cycloalkyl magnesium halides such as magnesium bromide are preferred. Many of these Grignard reagents are usually marketed as solutions such as a diethyl ether solution and a tetrahydrofuran solution, and it is preferable to use them in a solution state.

  The amount of Grignard reagent (I) used is preferably 0.1 to 5 equivalents, more preferably 0.5 to 1.5 equivalents, and equivalents with respect to the hydroxyl groups of the polyoxyalkylene polymer (a). Is more preferable. When the amount used is larger than this, there is a possibility of affecting the reaction with the compound (G2), and when it is small, there is a concern that the reactivity with the compound (G2) is lowered.

  In the reaction of the polymer (a) with the Grignard reagent (I), a reaction solvent can be used in addition to the solvent contained in the Grignard reagent (I). As the reaction solvent, an aprotic solvent that does not react with the Grignard reagent (I) is preferable. Specifically, ether solvents such as dimethyl ether, diethyl ether, and tetrahydrofuran, aromatic solvents such as benzene and toluene, hexane, and the like. There may be mentioned hydrocarbon solvents. Further, since the Grignard reagent (I) easily reacts with moisture, it is preferable to use a dehydrated solvent.

  The reaction between the polymer (a) and the Grignard reagent (I) is preferably carried out in a nitrogen atmosphere because the Grignard reagent (I) easily reacts with moisture. Moreover, as reaction temperature, -80 to 100 degreeC is preferable, and 0 to 30 degreeC is more preferable.

  As the compound (G2) to be reacted with the polyoxyalkylene polymer having an alkoxide group, unsaturated acid halogen compounds, carboxylic acid compounds and the like shown in the above method (a) can be used. Of these, chloroacrylic acid is preferred from the viewpoint of the reactivity of the resulting polymer (A).

  As a method for producing a polyoxyalkylene polymer having a halogen atom, a method of reacting a polymer (a) with carbon tetrachloride or carbon tetrabromide in the presence of triphenylphosphine, a polymer (a) Examples thereof include a method of reacting with phosphorus pentachloride, thionyl chloride, sulfinyl chloride and replacing the hydroxyl group with a chlorine atom.

  As the compound (G2) having an unsaturated group to be reacted with a polymer having a halogen atom, salts of the carboxylic acid compounds shown in the above method (a), for example, sodium (meth) acrylate, (meth) acrylic Potassium acid etc. can be used.

  As a method for producing a polyoxyalkylene polymer having an amino group, a method of reacting a polymer (a) with an amino acid, a method of replacing the hydroxyl group of the polymer (a) with a halogen atom, and reacting with a hexamethylenetetramine, A polymer in which a hydroxyl group is substituted with a halogen atom is reacted with phthalimide and potassium hydroxide or potassium phthalimide to obtain a polymer having a phthalimide group, and then reacted with hydrazine or potassium hydroxide to form an amino group. And a method for obtaining a polymer having the following.

  As the compound (G2) to be reacted with the polyoxyalkylene polymer having an amino group, the same compound (G1) as shown in the above method (a) can be used. In addition, in the reaction with the compound (G2), the above additive (G) may or may not be used.

  As a method for synthesizing the polyoxyalkylene polymer (A) having the structure of the general formula (2), after reacting the polyoxyalkylene polymer (a) having a hydroxyl group with the diisocyanate compound (J), an isocyanate group is reacted. And a method of reacting with a (meth) acrylic monomer (K) having a substituent that reacts with.

  The diisocyanate compound (J) is not particularly limited. For example, hexamethylene diisocyanate, isophorone diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, dicyclohexylmethane-4,4 Aliphatic and alicyclic such as' -diisocyanate, m-xylylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, tetramethylxylylene diisocyanate, norbornane diisocyanate, trans-cyclohexane diisocyanate, dimer acid diisocyanate, lysine diisocyanate Diisocyanates; tolylene diisocyanate, diphenylmethane diisocyanate, polymeric MDI, 1,5-na Ji diisocyanate, o- tolylene diisocyanate, and aromatic diisocyanates such as p- phenylene isocyanate.

  The amount of the diisocyanate compound (J) used is preferably from 0.1 to 10 molar equivalents, more preferably from 0.5 to 5 molar equivalents, based on the hydroxyl groups of the polyoxyalkylene polymer (a). When the amount used is less than 0.1 molar equivalent, the reactivity may decrease. When the amount used exceeds 10 molar equivalent, the reaction with the (meth) acrylic monomer (K) may be adversely affected. There is.

  Although it does not specifically limit as (meth) acrylic-type monomer (K) which has a substituent which reacts with an isocyanate group, For example, (meth) acrylic acid, (meth) acrylic acid-2-hydroxyethyl, (meth) acrylic acid 2-hydroxypropyl, 2-aminoethyl (meth) acrylate, and the like. Of these, 2-hydroxyethyl acrylate is preferred from the viewpoint of availability and ease of handling.

  The amount of the (meth) acrylic monomer (K) used is preferably from 0.1 molar equivalent to 10 molar equivalent, preferably from 0.5 molar equivalent to 5 molar equivalent, based on the hydroxyl group of the polyoxyalkylene polymer (a). Is more preferable. When the amount used is less than 0.1 molar equivalent, the reactivity may decrease. When the amount used exceeds 10 molar equivalent, there is a concern that it is economically disadvantageous.

  In the case of reacting the hydroxyl group of the polyoxyalkylene polymer (a) with the diisocyanate compound (J) and the (meth) acryloyl monomer (K) having a substituent that reacts with the isocyanate group, a titanium compound, a tin compound, a zirconium compound, etc. When used together as an additive (H3), the reactivity may increase. Examples of titanium compounds include tetrabutyl titanate, tetrapropyl titanate, titanium tetrakis (acetylacetonate), titanium diisopropoxybis (acetylacetonato), titanium diisopropoxybis (ethyl acetate), and the like. Examples of tin compounds include dibutyltin dilaurate, dibutyltin maleate, dibutyltin phthalate, dibutyltin dioctanoate, dibutyltin bis (2-ethylhexanoate), dibutyltin bis (methyl maleate), dibutyltin bis (ethyl maleate) , Dibutyl tin bis (butyl maleate), dibutyl tin bis (octyl maleate), dibutyl tin bis (tridecyl maleate), dibutyl tin bis (benzyl maleate), dibutyl tin diacetate, dioctyl tin bis ( Tilmaleate), dioctyltin bis (octylmaleate), dibutyltin dimethoxide, dibutyltin bis (nonylphenoxide), dibutenyltin oxide, dibutyltin oxide, dibutyltin bis (acetylacetonate), dibutyltin bis (ethylacetoacetonate) ), A reaction product of dibutyltin oxide and a silicate compound, a reaction product of dibutyltin oxide and a phthalate ester, and the like, and examples of the zirconium compound include zirconium tetrakis (acetylacetonate).

  The additive (H3) may or may not be used, but when used, it is preferably 1 ppm to 1000 ppm, more preferably 5 ppm to 500 ppm, based on the polymer (a). When the amount used is less than 1 ppm, a sufficient effect may not be obtained, and when more than 1000 ppm, the cured product obtained by curing the polymer (A) may be affected.

  Examples of the synthesis method of the polyoxyalkylene polymer (A) having the structure of the general formula (3) include a method of reacting the polyoxyalkylene polymer (a) having a hydroxyl group with the isocyanate compound (D). .

Although it does not restrict | limit especially as an isocyanate type compound (D), General formula (4):
^{O = C = N-R 2} -O-C (= O) -C (R 1) = CH 2 (4)
(In the formula, R ¹ and R ² are the same as above.)
The following compounds represented by the formula:

  Of these, 2-acryloyloxyethyl isocyanate and 2-methacryloyloxyisocyanate are preferable and 2-acryloyloxyethyl isocyanate is more preferable from the viewpoints of reactivity and availability.

  As usage-amount of an isocyanate type compound (D), 0.1-5 equivalent is preferable with respect to the hydroxyl group of a polyoxyalkylene type polymer (a), 0.5-1.5 equivalent is more preferable, and is equivalent. More preferably. When the amount used is larger than this, it is economically disadvantageous, and when it is small, the curability of the resulting polyoxyalkylene polymer (A) tends to be lowered.

  When reacting the polyoxyalkylene polymer (a) and the isocyanate compound (D), dibutyltin (mercapto acid ester) (E) is used. Although it does not specifically limit as dibutyltin (mercapto ester) (E), For example, dibutyltin (methyl mercapto acid), dibutyltin (ethyl mercapto acid), dibutyltin (mercaptoic acid n-propyl), dibutyltin (mercapto) Isopropyl), dibutyltin (n-butyl mercaptoate), dibutyltin (isobutylmercaptoate), dibutyltin (sec-butylmercaptoate), dibutyltin (tert-butylmercaptoate), dibutyltin (n-pentylmercaptoate) ), Dibutyltin (neopentyl mercapto), dibutyltin (n-hexyl mercaptoate), dibutyltin (cyclohexyl mercaptoate), dibutyltin (n-heptylmercaptoate), dibutyltin (n-octylmercapto), dibutyltin (Mercapto acid 2-ethyl Sil), dibutyltin (nonyl mercaptoate), dibutyltin (decyl mercaptoate), dibutyltin (dodecylmercaptoate), dibutyltin (phenyl mercaptoate), dibutyltin (toluyl mercaptoate), dibutyltin (benzyl mercaptoate) Etc. More specifically, examples include Neostan U-360 and Neostan U-350 manufactured by Nitto Kasei Co., Ltd.

  The amount of dibutyltin (mercapto acid ester) (E) used is preferably 10 ppm to 500 ppm, more preferably 25 ppm to 100 ppm, and still more preferably 40 to 60 ppm with respect to the polyoxyalkylene polymer (a). If the amount used is larger than this, a by-product may be generated, and if it is smaller than this amount, the reactivity may be lowered.

  When the polyoxyalkylene polymer (a) is reacted with the isocyanate compound (D), a solvent may or may not be used. When a solvent is used, a solvent in which the polymer (a) is dissolved is preferable. Although it does not restrict | limit especially as a solvent, For example, toluene, hexane, etc. are mention | raise | lifted. The amount of the solvent used can be appropriately determined from the viewpoint of easiness of stirring.

  Examples of the main chain skeleton of the polyoxyalkylene polymer (A) include polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymer, polyoxypropylene- A polyoxybutylene copolymer or the like can be used, but a polyoxypropylene polymer is preferable.

The polyoxyalkylene polymer essentially has the general formula (5):
—R ³ —O— (5)
(Wherein R ³ is a linear or branched alkylene group having 1 to 14 carbon atoms), and R ³ described in the general formula (5) is A linear or branched alkylene group having 1 to 14 carbon atoms is preferred, and a linear or branched alkylene group having 2 to 4 carbon atoms is more preferred. There is no limitation in particular as a repeating unit as described in General formula (5), For example,

Etc. The main chain skeleton of the polyoxyalkylene polymer (A) may consist of only one type of repeating unit, or may consist of two or more types of repeating units. In particular, a polymer composed mainly of a propylene oxide polymer is preferred because it is amorphous and has a relatively low viscosity.

  The method for synthesizing the polyoxyalkylene polymer is not particularly limited. For example, a polymerization method using an alkali catalyst such as KOH, an organoaluminum compound disclosed in JP-A-61-215623, and porphyrin are reacted. Polymerization method using transition metal compound-porphyrin complex catalyst such as the obtained complex, Japanese Patent Publication No. 46-27250, Japanese Patent Publication No. 59-15336, US Pat. No. 3,278,457, US Pat. No. 3,278,458, US Pat. No. 3,278,459, US Pat. No. 3,427,256 , US Pat. No. 3,427,334, US Pat. No. 3,427,335, etc., a polymerization method using a double metal cyanide complex catalyst, a polymerization method using a catalyst comprising a polyphosphazene salt disclosed in Japanese Patent Application Laid-Open No. 10-273512, Phosphine disclosed in Japanese Patent No. 11060722 A polymerization method using a catalyst comprising Azen compounds.

  The polyoxyalkylene polymer (A) may be linear or branched, and its number average molecular weight is preferably from 3,000 to 100,000, more preferably from 3,000 in terms of polystyrene in GPC. 50,000, particularly preferably from 3,000 to 30,000. If the number average molecular weight is less than 3,000, the cured product tends to be inconvenient in terms of stretchability, and if it exceeds 100,000, the viscosity tends to be inconvenient because of high viscosity.

  The molecular weight distribution of the polyoxyalkylene polymer (A) is not particularly limited, but is preferably narrow, preferably less than 2.00, more preferably 1.60 or less, and particularly preferably 1.40 or less. As the molecular weight distribution increases, the viscosity tends to increase, and therefore workability tends to deteriorate.

  The main chain skeleton and the synthesis method of the polyoxyalkylene polymer (a) having a hydroxyl group are the same as those of the polyoxyalkylene polymer (A).

  The composition for heat-radiation sheets of this invention contains an initiator (B). Although it does not restrict | limit especially as an initiator (B), A photoinitiator, a thermal-polymerization initiator, a redox initiator, etc. are mention | raise | lifted. The photopolymerization initiator, the thermal polymerization initiator, and the redox initiator may be used alone or as a mixture of two or more, but when used as a mixture, various initiators may be used. It is preferable that the usage-amount exists in each range mentioned later.

Examples of the photopolymerization initiator include a photoradical initiator, a photoanion initiator, and a near-infrared photopolymerization initiator. A photoradical initiator and a photoanion initiator are preferred, and a photoradical initiator is particularly preferred.

  Examples of the photo radical initiator include acetophenone, propiophenone, benzophenone, xanthol, fluorin, benzaldehyde, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4-methylacetophenone, 3-pentylacetophenone, 2, 2-diethoxyacetophenone, 4-methoxyacetophenone, 3-bromoacetophenone, 4-allylacetophenone, p-diacetylbenzene, 3-methoxybenzophenone, 4-methylbenzophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, 4 -Chloro-4'-benzylbenzophenone, 3-chloroxanthone, 3,9-dichloroxanthone, 3-chloro-8-nonylxanthone, benzoin, benzoy Methyl ether, benzoin butyl ether, bis (4-dimethylaminophenyl) ketone, benzylmethoxy ketal, 2-chlorothioxanthone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl- Phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl 2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, dibenzoyl and the like. Of these, α-hydroxyketone compounds (for example, benzoin, benzoin methyl ether, benzoin butyl ether, 1-hydroxy-cyclohexyl-phenyl-ketone, etc.), phenylketone derivatives (for example, acetophenone, propiophenone, benzophenone, 3-methyl) Acetophenone, 4-methylacetophenone, 3-pentylacetophenone, 2,2-diethoxyacetophenone, 4-methoxyacetophenone, 3-bromoacetophenone, 4-allylacetophenone, 3-methoxybenzophenone, 4-methylbenzophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, 4-chloro-4′-benzylbenzophenone, bis (4-dimethylaminophenyl) ketone, etc.) are preferred.

  Examples of the photoanion initiator include 1,10-diaminodecane, 4,4′-trimethylenedipiperazine, carbamates, and derivatives thereof, cobalt-amine complexes, aminooxyiminos, ammonium borates, and the like. can give.

  As the near infrared photopolymerization initiator, a near infrared light absorbing cationic dye or the like may be used. Near-infrared light absorbing cationic dyes are excited by light energy in the range of 650 to 1500 nm, for example, near-infrared light disclosed in JP-A-3-111402, JP-A-5-194619, etc. It is preferable to use an absorbing cationic dye-borate anion complex or the like, and it is more preferable to use a boron sensitizer together.

  These photopolymerization initiators may be used alone or in combination of two or more, or may be used in combination with other compounds. Specifically, combinations with other compounds include combinations with amines such as diethanolmethylamine, dimethylethanolamine, and triethanolamine, and further combinations with iodonium salts such as diphenyliodonium chloride, methylene blue, and the like. Examples include dyes and those combined with amines.

  In addition, when using the said photoinitiator, polymerization inhibitors, such as hydroquinone, hydroquinone monomethyl ether, benzoquinone, and para tertiary butyl catechol, can also be added as needed.

  When a photopolymerization initiator is used as the initiator (B), the amount added is not particularly limited, but from the viewpoint of curability and storage stability, it is based on 100 parts by weight of the polyoxyalkylene polymer (A). 0.001 to 10 parts by weight is preferable.

  Although there is no restriction | limiting in particular as a thermal-polymerization initiator, An azo initiator, a peroxide initiator, a persulfate initiator, etc. are mention | raise | lifted.

  Suitable azo initiators include, but are not limited to, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) (VAZO 33), 2,2′-azobis (2- Amidinopropane) dihydrochloride (VAZO 50), 2,2′-azobis (2,4-dimethylvaleronitrile) (VAZO 52), 2,2′-azobis (isobutyronitrile) (VAZO 64), 2, 2′-azobis-2-methylbutyronitrile (VAZO 67), 1,1-azobis (1-cyclohexanecarbonitrile) (VAZO 88) (all available from DuPont Chemical), 2,2′-azobis (2- Cyclopropylpropionitrile) and 2,2′-azobis (methylisobutylate) (V-601) (available from Wako Pure Chemical Industries, Ltd.) ) It is and the like.

  Suitable peroxide initiators include, but are not limited to, benzoyl peroxide, acetyl peroxide, lauroyl peroxide, decanoyl peroxide, dicetyl peroxydicarbonate, di (4-t-butylcyclohexyl). Peroxydicarbonate (Perkadox 16S) (available from Akzo Nobel), di (2-ethylhexyl) peroxydicarbonate, t-butyl peroxypivalate (Lupersol 11) (available from Elf Atochem), t-butyl per Examples include oxy-2-ethylhexanoate (Trigonox 21-C50) (available from Akzo Nobel) and dicumyl peroxide.

  Suitable persulfate initiators include, but are not limited to, potassium persulfate, sodium persulfate, and ammonium persulfate.

  A preferred thermal polymerization initiator is selected from the group consisting of azo initiators and peroxide initiators. More preferred are 2,2'-azobis (methylisobutylate), t-butyl peroxypivalate, di (4-t-butylcyclohexyl) peroxydicarbonate, and mixtures thereof.

  A thermal polymerization initiator may be used independently or may use 2 or more types together.

  When a thermal polymerization initiator is used as the initiator (B), the thermal polymerization initiator is present in a catalytically effective amount, and its addition amount is not particularly limited, but the (A) component of the present invention, and others When the total amount of the monomer and / or oligomer mixture described later that can be added to 100 parts by weight is 100 parts by weight, it is preferably about 0.01 to 5 parts by weight, more preferably about 0.025 to 2 parts by weight.

  Furthermore, the redox (oxidation reduction) type | system | group initiator which can be used as an initiator (B) can be used in a wide temperature range. In particular, the following initiator species can be advantageously used at room temperature.

  Suitable redox initiators include, but are not limited to, combinations of the above persulfate initiators and reducing agents (sodium metabisulfite, sodium bisulfite, etc.); organic peroxides and tertiary amines. Combinations such as a combination of benzoyl peroxide and dimethylaniline, a combination of cumene hydroperoxide and anilines; a combination of organic peroxide and transition metal, such as a combination of cumene hydroperoxide and cobalt naphthate, and the like. Preferred redox initiators are a combination of organic peroxide and tertiary amine, a combination of organic peroxide and transition metal, and more preferably a combination of cumene hydroperoxide and anilines, cumene hydroperoxide. And cobalt naphthate.

  A redox initiator may be used independently or may use 2 or more types together.

  When a redox initiator is used as the initiator (B), the redox initiator is present in a catalytically effective amount, and its addition amount is not particularly limited, but the (A) component of the present invention, and others Is preferably about 0.01 to 5 parts by weight, more preferably about 0.025 to 2 parts by weight, when the total amount of the monomer and / or oligomer mixture described below that can be added to 100 parts by weight is 100 parts by weight. .

  The composition for heat dissipation sheet of the present invention contains a heat conductive filler (C).

  As the heat conductive filler (C), a commercially available general good heat conductive filler can be used. Among these, metal oxides such as aluminum oxide, magnesium oxide, beryllium oxide, titanium oxide, zirconium oxide, and zinc oxide in terms of thermal conductivity, availability, and electrical insulation; boron nitride, aluminum nitride, silicon nitride, etc. Metal nitrides; metal carbides such as boron carbide, aluminum carbide and silicon carbide; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; crystalline silica; calcined acrylonitrile polymer, calcined furan resin, calcined cresol resin Products, burned products of polyvinyl chloride, burned products of sugar, burned products of organic polymers such as burned products of charcoal; nitrogen carbide and the like are preferable. Further, from the viewpoints of availability and thermal conductivity, aluminum oxide, boron nitride, aluminum nitride, silicon carbide, aluminum hydroxide, and crystalline silica are more preferable, and aluminum oxide, boron nitride, aluminum nitride, and aluminum hydroxide are particularly preferable. .

  In addition, these thermally conductive fillers have a silane coupling agent (vinyl silane, epoxy silane, (meth) acryl silane, isocyanate silane, chlorosilane, etc. from the viewpoint of improving dispersibility in the polyoxyalkylene polymer (A). , Aminosilane, etc.) and titanate coupling agents (alkoxy titanate, amino titanate, etc.), or fatty acids (caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, Unsaturated fatty acids such as sorbic acid, elaidic acid, oleic acid, linoleic acid, linolenic acid, and erucic acid) and resin acids (abietic acid, pimaric acid, levopimaric acid, neoabietic acid, parastrinic acid, dehydroapietic acid, isopimar Acid, Sandaraco Pima It is preferable that the surface is treated with oxalic acid, komuric acid, secodehydroabietic acid, dihydroabietic acid or the like.

  The amount of the heat conductive filler used is such that the heat conductivity of the heat conductive material obtained from the heat radiating sheet composition of the present invention can be increased. (%) Is preferably 25% by volume or more of the total composition. If it is less than 25% by volume, the thermal conductivity tends to be insufficient. When a higher thermal conductivity is desired, the amount of the thermally conductive filler used is more preferably 40% by volume or more in the total composition.

  Here, the volume fraction (%) of the thermally conductive filler is calculated from the weight fraction and specific gravity of each of the resin component and the thermally conductive filler, and is obtained by the following equation. In the following formula, the thermally conductive filler is simply referred to as “filler”.

Filler volume ratio (volume%) = (filler weight ratio / filler specific gravity) ÷ [(resin weight ratio / resin weight specific gravity) + (filler weight ratio / filler specific gravity)] × 100
Here, the resin component refers to all components excluding the thermally conductive filler, and specifically refers to the components (A) and (B), further the component (F), and other various additives.

  Further, as one method for increasing the filling rate of the heat conductive filler with respect to the polyoxyalkylene polymer (A), it is preferable to use two or more heat conductive fillers having different particle diameters in combination. In this case, it is preferable that the heat conductive filler having a large particle diameter exceeds 10 μm, and the heat conductive filler having a small particle diameter is 10 μm or less.

These thermally conductive fillers are not only of the same type of thermally conductive filler, but also of different types.
More than one species can be used in combination.

  The composition for heat dissipation sheet of the present invention may contain an organic carboxylic acid compound (F) in order to improve the releasability.

  Examples of the organic carboxylic acid compound (F) include a stearic acid compound, and other than the stearic acid compound, a saturated fatty acid compound having 1 to 18 carbon atoms, an unsaturated fatty acid compound having 3 to 18 carbon atoms, and 2 to 36 And aliphatic dicarboxylic acid compounds.

  Examples of the stearic acid compound include lead stearate, lithium stearate, lithium 12-hydroxystearate, sodium stearate, sodium 12-hydroxystearate, potassium stearate, 12-hydroxypotassium stearate, magnesium stearate, 12 -Metal stearates such as magnesium hydroxystearate, calcium stearate, calcium 12-hydroxystearate, barium stearate, barium 12-hydroxystearate, zinc stearate, zinc 12-hydroxystearate; stearic acid, monoglyceride stearate, Examples include methyl stearate. Of these, calcium stearate, lead stearate, and zinc stearate are preferred.

  In addition, the said organic carboxylic acid compound may be used independently and may be used together 2 or more types.

  The amount of the organic carboxylic acid compound (F) used is preferably 0.025 to 5 parts by weight with respect to 100 parts by weight of the polyoxyalkylene polymer (A), from the viewpoint of releasability and physical property balance of the sheet. More preferably, it is 0.05-4 weight part.

The heat radiating sheet composition of the present invention may be used in combination with a polymerizable monomer and / or oligomer for the purpose of improving surface curability, imparting toughness, and improving workability by reducing viscosity. Furthermore, you may mix | blend various additives etc. in order to adjust a physical property with the composition for thermal radiation sheets of this invention as needed.

  As the polymerizable monomer and / or oligomer, a monomer and / or oligomer having a radical polymerizable group or a monomer and / or oligomer having an anion polymerizable group is preferable from the viewpoint of curability.

  Examples of the radical polymerizable group include (meth) acryloyl group, styrene group, acrylonitrile group, vinyl ester group, N-vinylpyrrolidone group, acrylamide group, conjugated diene group, vinyl ketone group, vinyl chloride group and the like. Especially, the thing which has a (meth) acryloyl group from a reactive point is preferable.

  Examples of the anionic polymerizable group include (meth) acryloyl group, styrene group, acrylonitrile group, N-vinylpyrrolidone group, acrylamide group, conjugated diene group, vinyl ketone group and the like. Especially, the thing which has a (meth) acryloyl group from a reactive point is preferable.

  Specific examples of the monomer include (meth) acrylate monomers, cyclic acrylates, styrene monomers, acrylonitrile, vinyl ester monomers, N-vinyl pyrrolidone, acrylamide monomers, conjugated diene monomers, vinyl ketone monomers, vinyl halides. -Examples include vinylidene halide monomers and polyfunctional monomers.

  (Meth) acrylate monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, (meth ) Isobutyl acrylate, tert-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, n-heptyl (meth) acrylate, (meth ) N-octyl acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate , Phenyl (meth) acrylate, toluyl (meth) acrylate, (meth) acrylic Benzyl, 2-methoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, stearyl (meth) acrylate, ( (Meth) acrylic acid glycidyl, (meth) acrylic acid 2-aminoethyl, γ- (methacryloyloxypropyl) trimethoxysilane, (meth) acrylic acid ethylene oxide adduct, (meth) acrylic acid trifluoromethylmethyl, (meta ) 2-trifluoromethylethyl acrylate, 2-perfluoroethylethyl (meth) acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth) acrylate, 2-perfluoroethyl (meth) acrylate , Perfluoromethyl (meth) acrylate, (meth) Diperfluoromethylmethyl acrylate, 2-perfluoromethyl-2-perfluoroethylethyl (meth) acrylate, 2-perfluorohexylethyl (meth) acrylate, 2-perfluorodecylethyl (meth) acrylate, Examples include (meth) acrylic acid 2-perfluorohexadecylethyl. Moreover, the compound etc. which are shown by the following Formula can also be mention | raise | lifted. In the following formula, n represents an integer of 0-20.

  Examples of the styrene monomer include styrene and α-methylstyrene. Examples of vinyl ester monomers include vinyl acetate, vinyl propionate, and vinyl butyrate. Examples of acrylamide monomers include acrylamide and N, N-dimethylacrylamide. Examples of the conjugated diene monomer include butadiene and isoprene. Examples of the vinyl ketone monomer include methyl vinyl ketone. Examples of the vinyl halide / vinylidene halide monomer include vinyl chloride, vinyl bromide, vinyl iodide, vinylidene chloride, and vinylidene bromide.

  Multifunctional monomers include trimethylolpropane triacrylate, neopentyl glycol polypropoxydiacrylate, trimethylolpropane polyethoxytriacrylate, bisphenol F polyethoxydiacrylate, bisphenol A polyethoxydiacrylate, dipentaerythritol polyhexanolide hexa Chlorate, tris (hydroxyethyl) isocyanurate polyhexanolide triacrylate, tricyclodecane dimethylol diacrylate 2- (2-acryloyloxy-1,1-dimethyl) -5-ethyl-5-acryloyloxymethyl-1 , 3-dioxane, tetrabromobisphenol A diethoxydiacrylate, 4,4-dimercaptodiphenyl sulfide dimethacrylate, polytetra Chi glycol diacrylate, 1,9-nonanediol diacrylate, and ditrimethylolpropane tetraacrylate and the like.

  As the oligomer, epoxy acrylate resins such as bisphenol A type epoxy acrylate resin, phenol novolak type epoxy acrylate resin, cresol novolak type epoxy acrylate resin, COOH group-modified epoxy acrylate type resin; polyol (polytetramethylene glycol, ethylene glycol and adipine) Acid polyester diol, ε-caprolactone modified polyester diol, polypropylene glycol, polyethylene glycol, polycarbonate diol, hydroxyl-terminated hydrogenated polyisoprene, hydroxyl-terminated polybutadiene, hydroxyl-terminated polyisobutylene, etc. and organic isocyanate (tolylene diisocyanate, isophorone diisocyanate, diphenylmethane) Diisocyanate, hexamethylene dii Urethane resins obtained from cyanate, xylylene diisocyanate, etc.) with hydroxyl group-containing (meth) acrylate (hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, pentaerythritol triacrylate, etc.) Urethane acrylate resin obtained by reaction; resin in which a (meth) acryl group is introduced into the polyol via an ester bond; polyester acrylate resin, poly (meth) acryl acrylate resin (having a polymerizable reactive group) Poly (meth) acrylate resin) and the like.

  Among the above, monomers and / or oligomers having a (meth) acryloyl group are preferred. The number average molecular weight of the monomer and / or oligomer having a (meth) acryloyl group is preferably 5000 or less. Furthermore, in the case of using a monomer for improving the surface curability and reducing the viscosity for improving workability, it is more preferable that the molecular weight is 1000 or less because of good compatibility.

  The amount of the polymerizable monomer and / or oligomer used is 1 with respect to 100 parts by weight of the polyoxyalkylene polymer (A) from the viewpoint of improving surface curability, imparting toughness, and workability due to viscosity reduction. -200 weight part is preferable and 5-100 weight part is more preferable.

Reinforcing silica may be added to the heat radiating sheet composition of the present invention from the viewpoint of improving the strength of the heat radiating sheet. Examples of the reinforcing silica include fumed silica and precipitated silica. Among these, particles having a particle size of 50 μm or less and a specific surface area of 80 m ² / g or more are preferable from the effect of reinforcing properties. In addition, the measuring method of a specific surface area is as the below-mentioned.

  Furthermore, surface-treated silica such as organosilane, organosilazane, diorganocyclopolysiloxane and the like is more preferable because it is easy to exhibit fluidity suitable for molding.

  As a more specific example of the reinforcing silica, there is no particular limitation. However, Nippon Aerosil Co., Ltd., which is one of fumed silica, and Nippon Silica Industry Co., Ltd., which is one of precipitated silicas. Nipsil and the like.

  The reinforcing silica may be used alone or in combination of two or more.

  Although there is no restriction | limiting in particular in the addition amount of reinforcing silica, Preferably it is 0.1-100 weight part with respect to 100 weight part of polyoxyalkylene type polymer (A), More preferably, 0.5- 80 parts by weight, more preferably 1 to 50 parts. When the blending amount is less than 0.1 part by weight, the effect of improving the reinforcing property may not be sufficient, and when it exceeds 100 parts by weight, the workability of the heat radiating sheet composition may be deteriorated.

  In addition to the reinforcing silica, various fillers may be used as necessary in the heat radiating sheet composition of the present invention. The filler is not particularly limited, but wood powder, pulp, cotton chips, asbestos, glass fiber, carbon fiber, mica, walnut shell powder, rice husk powder, graphite, diatomaceous earth, white clay, dolomite, silicic anhydride Reinforcing fillers such as hydrous silicic acid and carbon black; heavy calcium carbonate, colloidal calcium carbonate, magnesium carbonate, diatomaceous earth, calcined clay, clay, talc, titanium oxide, bentonite, organic bentonite, ferric oxide, bengara , Aluminum fine powder, Flint powder, Zinc oxide, Active zinc white, Zinc powder, Zinc carbonate, Filler such as Shirasu balloon; Asbestos, Glass fiber, Glass filament, Carbon fiber, Kevlar fiber, Polyethylene fiber, etc. Examples include fibrous fillers. Of these fillers, carbon black, calcium carbonate, titanium oxide, talc and the like are preferable. If you want to obtain a heat-dissipating sheet with low strength and high elongation, add a filler selected from titanium oxide, calcium carbonate, talc, ferric oxide, zinc oxide, shirasu balloon, etc. Can do.

  In general, when calcium carbonate has a small specific surface area, the effect of improving the breaking strength, breaking elongation, adhesion and weather resistance of the heat-dissipating sheet may not be sufficient. As the value of the specific surface area is larger, the effect of improving the breaking strength, breaking elongation, adhesion and weather resistance of the heat-dissipating sheet becomes greater. Moreover, it is more preferable that the calcium carbonate is subjected to a surface treatment using a surface treatment agent. When surface-treated calcium carbonate is used, the workability of the composition of the present invention is improved as compared with the case of using non-surface-treated calcium carbonate, and the heat dissipation sheet composition has adhesion and weather resistance. It is thought that the improvement effect of is improved.

  Examples of the surface treatment agent include organic substances such as fatty acids, fatty acid soaps, and fatty acid esters, various surfactants, and various coupling agents such as silane coupling agents and titanate coupling agents. Specific examples include, but are not limited to, fatty acids such as caproic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, and oleic acid. And sodium salts and potassium salts of these fatty acids and alkyl esters of these fatty acids. Specific examples of surfactants include sulfuric acid ester type anionic surfactants such as sodium salts and potassium salts such as polyoxyethylene alkyl ether sulfates and long chain alcohol sulfates, alkylbenzene sulfonic acids, alkylnaphthalene sulfonic acids, paraffins. Examples thereof include sulfonic acid type anionic surfactants such as sodium salts and potassium salts such as sulfonic acid, α-olefin sulfonic acid and alkylsulfosuccinic acid.

  The treatment amount of the surface treatment agent is preferably in the range of 0.1 to 20% by weight (hereinafter referred to as “%”) with respect to calcium carbonate, and more preferably in the range of 1 to 5%. When the treatment amount is less than 0.1%, the workability, the adhesiveness and the weather resistance adhesion may not be improved sufficiently. When the treatment amount exceeds 20%, the storage stability of the heat-dissipating sheet composition decreases. Sometimes.

  Although there is no particular limitation, when calcium carbonate is used, colloidal calcium carbonate is used when particularly improving effects such as thixotropy of the compound, breaking strength of the heat radiation sheet, elongation at break, adhesion and weather resistance are expected. Is preferred. On the other hand, heavy calcium carbonate may be added for the purpose of lowering the viscosity of the compound, increasing the amount, reducing costs, etc. When using this heavy calcium carbonate, the following may be added as necessary. Can be used.

Heavy calcium carbonate is obtained by mechanically pulverizing and processing natural chalk (chalk), marble, limestone, and the like. There are dry methods and wet methods for pulverization methods, but wet pulverized products are often not preferred because they often deteriorate the storage stability of the heat-dissipating sheet composition of the present invention. Heavy calcium carbonate becomes products having various average particle sizes by classification. Although there is no particular limitation, when the effect of improving the breaking strength, breaking elongation, adhesion and weather resistance of the heat dissipation sheet is expected, the value of the specific surface area is 1.5 m ² / g or more and 50 m ² / g or less. , more preferably from ^2m 2 / g or more ^{50 m} 2 / g less, more preferably 2.4 m ² / g more ^{50m 2 / g, 3m 2 /} g or more ^{50 m} 2 / g and particularly preferably. When the specific surface area is less than 1.5 m ² / g, the improvement effect may not be sufficient. Of course, this is not the case when the viscosity is simply reduced or when the purpose is only to increase the viscosity.

  In addition, the value of the specific surface area means a measurement value by an air permeation method (a method for obtaining a specific surface area from air permeability with respect to a powder packed bed) performed according to JIS K 5101 as a measurement method. As a measuring instrument, it is preferable to use a specific surface area meter SS-100 manufactured by Shimadzu Corporation.

These fillers may be used alone or in combination of two or more according to the purpose and necessity. Although it is not particularly limited, for example, when heavy calcium carbonate with a specific surface area value of 1.5 m ² / g or more and collagen calcium carbonate are combined, the increase in viscosity of the compound is moderately suppressed. The effect of improving the breaking strength, breaking elongation, adhesion and weather resistance of the heat radiation sheet can be greatly expected.

  When the filler is used, the addition amount is preferably 5 to 1000 parts by weight with respect to 100 parts by weight of the polyoxyalkylene polymer (A), and preferably 20 to 500 parts by weight. It is more preferable to use in the range of 40 to 300 parts by weight. When the blending amount is less than 5 parts by weight, the effect of improving the breaking strength, breaking elongation, adhesion and weather resistance of the heat radiation sheet may not be sufficient. Workability may be reduced. A filler may be used independently and may be used together 2 or more types.

  The composition for heat radiating sheets of the present invention may contain a tackifying resin. The tackifying resin is not particularly limited, and examples thereof include a phenol resin, a modified phenol resin, a cyclopentadiene-phenol resin, a xylene resin, a chroman resin, a petroleum resin, a terpene resin, a terpene phenol resin, and a rosin ester resin. More specifically, YS Resin PX, YS Resin PXN, YS Polystar U, YS Polystar T, YS Polystar S, YS Polyster S, Mighty Ace G, Mighty Ace K, YS Resin TO, YS Resin TR , YS Resin SX, Clearon P, Clearon M, Clearon K; Arakawa Chemical Industry Co., Ltd. Archon, Ester Gum, Pencel, Superester, Tamanol, High Pale; Harima Kasei Co., Ltd. Harrier Star, Neotor, Hari Mac, Halitac, etc Can be given. Among these, from the viewpoint of compatibility with the polyoxyalkylene polymer (A), terpene resins are preferable, and terpene phenol resins are more preferable.

  The amount of tackifying resin used is not particularly limited, but is preferably 5 to 100 parts by weight, more preferably 20 to 80 parts by weight, based on 100 parts by weight of the polyoxyalkylene polymer (A). . If the amount used is less than this range, the effect may not be sufficiently obtained, and if it exceeds this range, the viscosity becomes too high, and the workability may be deteriorated.

  Moreover, in the composition for heat-radiation sheets of this invention, you may use together 2 or more types of tackifying resin.

  An anti-aging agent may be blended in the composition for heat dissipation sheet of the present invention in order to adjust the physical properties. Although it does not restrict | limit especially as anti-aging agent, For example, conventionally well-known antioxidant and light stabilizer can be used suitably.

  Various types of antioxidants are known, and are described in, for example, “Antioxidant Handbook” issued by Taiseisha, “Degradation and Stabilization of Polymer Materials” (235-242) issued by CM Chemical Co., Ltd. Although various things are mention | raise | lifted, it is not necessarily limited to these. Examples of the antioxidant include thioethers such as MARK PEP-36 and MARK AO-23 (all are manufactured by Asahi Denka Co., Ltd.); Irgafos 38, Irgafos 168, Irgafos P-EPQ (all are BASF Corporation) And phosphorous antioxidants such as hindered phenol compounds. Of these, hindered phenol compounds as shown below are preferred.

  Specific examples of the hindered phenol compound include the following. 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, mono (or di- or tri) (α-methylbenzyl) phenol, 2,2 '-Methylenebis (4-ethyl-6-tert-butylphenol), 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 4,4'-butylidenebis (3-methyl-6-tert-butylphenol) 4,4′-thiobis (3-methyl-6-tert-butylphenol), 2,5-di-tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, triethylene glycol-bis- [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol Bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-t- Butylanilino) -1,3,5-triazine, pentaerythritol-tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3 , 5-di-t-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N, N′-hexamethylenebis (3 5-di-t-butyl-4-hydroxy-hydrocinnamamide), 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 1, 3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, ethyl bis (3,5-di-tert-butyl-4-hydroxybenzylphosphonate) ) Calcium, Tris- (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, 2,4-2,4-bis [(octylthio) methyl] o-cresol, N, N′-bis [ 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] hydrazine, tris (2,4-di-tert-butylphenyl) phosphite, 2- (5-methyl-2-hydroxyphenyl) Benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (3,5-di-t-butyl-2- Droxyphenyl) benzotriazole, 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-amyl-2-hydroxyphenyl) benzotriazole, 2- (2'-hydroxy-5'-t-octylphenyl) -benzotriazole, methyl- 3- [3-t-butyl-5- (2H-benzotriazol-2-yl) -4-hydroxyphenyl] propionate-condensate with polyethylene glycol (molecular weight about 300), hydroxyphenylbenzotriazole derivative, 2- ( 3,5-di-tert-butyl-4-hydroxybenzyl) -2-n-butylmalonate bis (1,2,2 6,6-pentamethyl-4-piperidyl), e.g., 2,4-di -t- butyl-3,5-di -t- butyl-4-hydroxybenzoate and the like. In terms of product names, Nocrack 200, Nocrack M-17, Nocrack SP, Nocrack SP-N, Nocrack NS-5, Nocrack NS-6, Nocrack NS-30, Nocrack 300, Nocrack NS-7, Nocrack DAH (all above Also manufactured by Ouchi Shinsei Chemical Co., Ltd.), MARK AO-30, MARK AO-40, MARK AO-50, MARK AO-60, MARK AO-616, MARK AO-635, MARK AO-658, MARK AO- 80, MARK AO-15, MARK AO-18, MARK 328, MARK AO-37 (all are manufactured by Asahi Denka Co., Ltd.), IRGANOX-245, IRGANOX-259, IRGANOX-565, IRGANOX-1010, IRGANOX-1024 , IRG NOX-1035, IRGANOX-1076, IRGANOX-1081, IRGANOX-1098, IRGANOX-1222, IRGANOX-1330, IRGANOX-1425WL (all are manufactured by BASF Corporation), Sumilizer GA-80 (all are Sumitomo Chemical) (Made by Corporation | KK) etc. can be illustrated, However, It is not limited to these.

  Furthermore, monoacrylate phenolic antioxidants having both acrylate groups and phenol groups, nitroxide compounds and the like can be mentioned.

  Examples of the monoacrylate phenol-based antioxidant include 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (trade name Sumilyzer GM), 2 , 4-di-t-amyl-6- [1- (3,5-di-t-amyl-2-hydroxyphenyl) ethyl] phenyl acrylate (trade name Sumitizer GS) and the like.

  Nitroxide compounds include, but are not limited to, cyclic hydroxyamines such as 2,2,6,6-substituted-1-piperidinyloxy radicals and 2,2,5,5-substituted-1-pyrrolidinyloxy radicals. The nitroxy free radicals from are illustrated. As the substituent, an alkyl group having 4 or less carbon atoms such as a methyl group or an ethyl group is suitable. Specific nitroxy free radical compounds include, but are not limited to, 2,2,6,6-tetramethyl-1-piperidinyloxy radical (TEMPO), 2,2,6,6-tetraethyl-1- Piperidinyloxy radical, 2,2,6,6-tetramethyl-4-oxo-1-piperidinyloxy radical, 2,2,5,5-tetramethyl-1-pyrrolidinyloxy radical, 1, Examples include 1,3,3-tetramethyl-2-isoindolinyloxy radical and N, N-di-t-butylamineoxy radical. Instead of the nitroxy free radical, a stable free radical such as a galvinoxyl free radical may be used.

  Examples of light stabilizers include benzotriazole compounds such as Tinuvin P, Tinuvin 234, Tinuvin 320, Tinuvin 326, Tinuvin 327, Tinuvin 329, and Tinuvin 213 (all of which are manufactured by BASF Corporation); Triazines such as Tinuvin 1577 UV absorbers such as benzoate compounds such as benzophenone compounds such as CHIMASSORB 81; benzoin compounds such as Tinuvin 120 (manufactured by BASF Corporation). Moreover, a hindered amine compound is more preferable. Specific examples of the hindered amine compound include the following, but are not limited thereto. Dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate of succinate, poly [{6- (1,1,3,3-tetramethylbutyl) Amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino}], N, N′-bis (3-aminopropyl) ethylenediamine -2,4-bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate, bis (2 , 2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, succinic acid-bis (2,2,6,6-tetra Methyl-4-piperidinyl) ester And the like. In terms of product names, Tinuvin 622LD, Tinuvin 144, CHIMASSORB 944LD, CHIMASSORB 119FL (all manufactured by BASF), ADK STAB LA-52, ADK STAB LA-57, ADK STAB LA-62, ADK STAB LA-67, ADK STAB LA-63, ADK STAB LA-68, ADK STAB LA-82, ADK STAB LA-87 (all manufactured by Asahi Denka Kogyo Co., Ltd.), Sanol LS-770, Sanol LS-765, Sanol LS-292, Sanol LS-2626, Sanol LS-1114, Sanol LS -744, Sanol LS-440 (all of which are manufactured by Sankyo Co., Ltd.) and the like, but are not limited thereto.

  Antioxidants may be used in combination with light stabilizers, and when used together, the effects are further exerted, and in particular, heat resistance may be improved. Tinuvin C353, tinuvin B75 (all of which are manufactured by BASF Corp.) in which an antioxidant and a light stabilizer are mixed in advance may be used.

  When using a polyoxyalkylene-based polymer having a (meth) acryloyl-based substituent in the molecule to produce a heat-dissipating sheet by photo radical curing, the polymerization progressed quickly, making it difficult to control and over-polymerizing. In some cases, the mechanical strength is insufficient, for example, an overcrosslinked state is obtained and the obtained heat dissipation sheet does not exhibit sufficient elongation. As a method for controlling the polymerization, by making the functional group involved in the polymerization a methacryloyl group, the polymerizability can be lowered as compared with the case of the acryloyl group, but in this case, the polymerizability may be extremely lowered. Many are not practical. In general, a polymerization inhibitor may be used, but this is for the purpose of suppressing the polymerization itself and is not suitable for controlling the polymerization. On the other hand, in order to improve the heat resistance and weather resistance of the obtained heat radiating sheet, an anti-aging agent may be added, but this is not used for the purpose of improving the initial physical properties of the heat radiating sheet. The monoacrylate phenol-based antioxidant can not only be used as an antioxidant but also can control polymerization, and can improve the elongation of the heat dissipation sheet. Since the physical property control of the heat dissipation sheet can be easily performed, the same ones as described above are exemplified. The said monoacrylate phenolic antioxidant may be used independently and may be used in combination of 2 or more type.

  Although the usage-amount of the said various antioxidants including a monoacrylate phenolic antioxidant is not specifically limited, In order to give the effect with a favorable mechanical property of the obtained heat-radiation sheet, a polyoxyalkylene type polymer ( A) 0.01 parts by weight or more is preferable with respect to 100 parts by weight, and 0.05 parts by weight or more is more preferable. Moreover, 5.0 weight part or less is preferable, 3.0 weight part or less is more preferable, and 2.0 weight part or less is further more preferable.

  You may mix | blend a plasticizer with the composition for thermal radiation sheets of this invention.

  As a plasticizer, phthalic acid esters such as dibutyl phthalate, diheptyl phthalate, di (2-ethylhexyl) phthalate, and butyl benzyl phthalate; dioctyl adipate, dioctyl sebacate, etc., for the purpose of adjusting physical properties and properties. Non-aromatic dibasic acid esters; esters of polyalkylene glycols such as diethylene glycol dibenzoate and triethylene glycol dibenzoate; phosphate esters such as tricresyl phosphate and tributyl phosphate; chlorinated paraffins; alkyl diphenyl, partial water And hydrocarbon oils such as terphenyl. These can be used alone or in admixture of two or more, but are not necessarily required.

  The amount of the plasticizer used is preferably 5 to 800 parts by weight with respect to 100 parts by weight of the polyoxyalkylene polymer (A) from the viewpoint of imparting elongation, workability, and preventing bleeding from the heat-radiating sheet.

  An organic solvent may be added to the heat radiating sheet composition of the present invention from the viewpoints of workability during coating, drying before and after curing, and the like.

  As the organic solvent, those having a boiling point of 50 to 180 ° C. are usually preferable because of excellent workability during coating and drying before and after curing. Specifically, alcohol solvents such as methanol, ethanol, isopropanol, n-butanol, isobutanol; methyl acetate, ethyl acetate, butyl acetate, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether, etc. Ester solvents; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; aromatic solvents such as toluene and xylene; and cyclic ether solvents such as dioxane. These solvents may be used alone or in combination of two or more.

  The amount of the solvent used is preferably 1 to 900 parts by weight with respect to 100 parts by weight of the polyoxyalkylene polymer (A) from the viewpoints of the finish of the heat dissipation sheet, workability, and drying.

  In order to improve the adhesiveness to various supports (plastic film etc.), you may add various adhesive improvement agents to the composition for heat dissipation sheets of this invention.

  Examples of the adhesion improver include alkyl alkoxysilanes such as methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, and n-propyltrimethoxysilane; dimethyldiisopropenoxysilane, methyltriisopropenoxy Silanes, alkyl isopropenoxy silanes such as γ-glycidoxypropylmethyldiisopropenoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyldimethylmethoxy Silane, γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-mercapto B pills trimethoxysilane, alkoxysilanes having a functional group such as γ- mercaptopropyl methyldimethoxysilane; silicone varnishes; polysiloxanes and the like.

  The amount of the adhesion improver used is 0.1 to 20 weights with respect to 100 parts by weight of the polyoxyalkylene polymer (A) from the viewpoint of the balance between the mechanical properties (elongation and strength) of the heat dissipation sheet and the adhesion. Part is preferred.

  The composition for a heat-dissipating sheet of the present invention can be prepared as a one-pack type in which all blending components are blended and sealed in advance. It can also be prepared as a two-component type in which the mixed B liquid is mixed immediately before molding.

  The heat radiating sheet is obtained by curing the heat radiating sheet composition with normal temperature, heating, and light. Moreover, the hardening method may be individual and may use 2 or more types together.

  The method for curing the heat radiating sheet composition is not particularly limited. When using a photoinitiator as an initiator (B), it can be hardened by irradiating light or an electron beam with an active energy ray source.

  The active energy ray source is not particularly limited, but may be, for example, a high pressure mercury lamp, a low pressure mercury lamp, an electron beam irradiation device, a halogen lamp, a light emitting diode, a semiconductor laser, or a metal halide lamp, depending on the nature of the photopolymerization initiator used. can give.

  When using a photoinitiator as an initiator (B), the curing temperature is preferably 0 ° C to 150 ° C, more preferably 5 ° C to 120 ° C.

  When a thermal polymerization initiator is used as the initiator (B), its curing temperature varies depending on the type of thermal polymerization initiator used, other compounds added, etc., but is usually preferably 50 ° C. to 250 ° C., 70 ° C. -200 degreeC is more preferable.

  When a redox initiator is used as the initiator (B), the curing temperature is preferably −50 ° C. to 250 ° C., more preferably 0 ° C. to 180 ° C.

  There is no restriction | limiting in particular as a usage method of the composition for thermal radiation sheets of this invention. When molding into a fixed shape such as a sheet, film, molded product, gasket, etc. by various commonly used molding methods such as injection molding, extrusion molding, compression molding, liquid injection molding, coater, calendar, etc. Alternatively, it can be applied and filled in an irregular shape like an adhesive, and then cured by heating.

  The composition for a heat-dissipating sheet of the present invention can form a heat conductive material that dissipates heat from electronic components such as a heater, temperature sensor, CPU, and transistor, etc., to a cooling member.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereby.

(Synthesis Example 1)
Polymerization of propylene oxide using a polyoxypropylene diol having a molecular weight of about 2,000 as an initiator, a zinc hexacyanocobaltate glyme complex catalyst, and a number average molecular weight of 28,500 having a terminal hydroxyl group (liquid feeding system: HLC manufactured by Tosoh Corporation) -8120 GPC, column: Tosoh TSK-GEL H type, polystyrene oxide molecular weight measured using THF as a solvent), polypropylene oxide (a-1) was obtained.

4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxy 0.02 part by weight, dibutyltin bis (mercapto ester) (100 parts by weight of polypropylene oxide (a-1) having a hydroxyl group ( E-1) (Nitto Kasei Co., Ltd. Neostan U-360) 50 ppm, 2-acryloyloxyethyl isocyanate (D-1) (Showa Denko Co., Ltd. Karenz AOI) 1.3 parts by weight was added at 90 ° C. Stir for 1 hour. ^The peak derived from the hydroxyl group of polypropylene oxide (a-1) disappears as measured by ¹ H-NMR (Avance III 400 MHz NMR system manufactured by Bruker), and the peak derived from the proton on the carbon to which the carbamate group is bonded (4. 91 ppm (multiple line)) appeared, and it was confirmed that a polyoxyalkylene polymer (A-1) having a (meth) acryloyl substituent at the terminal was obtained.

^{In the 1} H-NMR spectrum, the introduction ratio of the (meth) acryloyl substituent calculated from the ratio between the integrated value of the peak derived from the methyl group in the main chain and the integrated value of the peak derived from the acryloyl group was 90%. It was. Thereby, it turned out that a polyoxyalkylene type polymer (A-1) contains 1.8 (meth) acryloyl type substituents on the average per molecule. The molecular weight determined by GPC was 28,500.

(Synthesis Example 2)
380 parts by weight of acetone, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxy 0 per 100 parts by weight of polypropylene oxide (a-1) obtained by the same method as in Synthesis Example 1 0.01 parts by weight and 4.1 parts by weight of triethylamine (H1-1) were added and cooled by an ice water bath. To this, 3.6 parts by weight of acryloyl chloride (G1-1) was added dropwise and stirred for 3 hours. After completion of stirring, acetone was removed by devolatilization under reduced pressure. The obtained product was dissolved in tetrahydrofuran and separated and washed with an aqueous sodium bicarbonate solution and an aqueous sodium chloride solution. Magnesium sulfate is added to the taken-out organic layer and dried. After removing the magnesium sulfate by filtration, 0.01 parts by weight of 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxy in the filtrate. And evacuating under reduced pressure while heating to 100 ° C. ^The peak derived from the hydroxyl group of polypropylene oxide (a-1) disappears as measured by ¹ H-NMR (A Bruce Avance III 400 MHz NMR system), and the peak derived from the proton on the carbon to which the acryloyloxy group is bonded (5 .10 ppm (multiple line)) appeared, and it was confirmed that a polyoxyalkylene polymer (A-2) having an acryloyloxy group was obtained.

^{In the 1} H-NMR spectrum, the introduction ratio of the acryloyloxy group calculated from the ratio of the integrated value of the peak derived from the methyl group in the main chain and the integrated value of the peak derived from the proton on the carbon to which the acryloyloxy group is bonded is 80%. Thereby, it turned out that a polyoxyalkylene type polymer (A-2) contains 1.6 (meth) acryloyl type substituents on the average per molecule. The molecular weight determined by GPC was 28,500.

(Reference Example 1)
To the hydroxyl group of polypropylene oxide (a-1) obtained in the same manner as in Synthesis Example 1, 1.2 times equivalent of a methanol solution of NaOMe was added to distill off the methanol, and allyl chloride was further removed. The terminal hydroxyl group was converted to an allyl group by addition. Unreacted allyl chloride was removed by vacuum devolatilization. After mixing and stirring 300 parts by weight of n-hexane and 300 parts by weight of water with respect to 100 parts by weight of the obtained unpurified allyl group-terminated polypropylene oxide, water was removed by centrifugation, and the resulting hexane solution was further added. 300 parts by weight of water was mixed and stirred, and after removing water again by centrifugation, hexane was removed by vacuum devolatilization. As a result, a bifunctional polypropylene oxide having a number average molecular weight of about 28,500 having an allyl group at the end was obtained.

  With respect to 100 parts by weight of the obtained bifunctional polypropylene oxide, methyldimethoxysilane was prepared by using 150 ppm of an isopropanol solution having a platinum content of 3 wt% of Pt / 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex as a catalyst. The reaction was carried out with 1.2 parts by weight at 90 ° C. for 5 hours to obtain a methyldimethoxysilyl group-terminated polyoxypropylene polymer (P-1).

Further, in the measurement by ¹ H-NMR (measured in CDCl ₃ solvent using JNM-LA400 manufactured by JEOL), a signal corresponding to the exomethylene proton of the terminal allyl group of bifunctional polypropylene oxide (2H: 5. 2 ppm), a signal derived from methyl protons in the main chain (3H: near 1.1 ppm), a signal derived from a methyl group on the dimethoxymethylsilyl group of the polymer (P-1) (3H: near 0.1 ppm) The number of dimethoxymethylsilyl groups in the polymer (P-1) calculated from the integral ratio was about 1.6 on average per molecule.

Example 1
100 parts by weight of polyoxyalkylene polymer (A-1), 100 parts by weight of TCP (tricresyl phosphate, manufactured by Daihachi Chemical), 400 parts by weight of aluminum hydroxide (manufactured by Wako Pure Chemical Industries), Nyper BW (benzoyl par) 1 part by weight of oxide, manufactured by Nippon Oil & Fats, 1 part by weight of Irganox 1010 (pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], manufactured by BASF), and mixed well. Furthermore, it passed through 3 rolls 3 times and kneaded to obtain a heat radiating sheet composition.

  The obtained composition was pressed at 120 ° C. for 15 minutes to obtain a heat radiation sheet having a thickness of 2 mm.

(Example 2)
100 parts by weight of polyoxyalkylene polymer (A-1), 100 parts by weight of TCP (tricresyl phosphate, manufactured by Daihachi Chemical), 400 parts by weight of boron nitride (manufactured by Wako Pure Chemical Industries), Nyper BW (benzoyl peroxide) And 1 part by weight of Irganox 1010 (pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], manufactured by BASF) and mixed thoroughly. The composition for heat-radiating sheets was obtained by passing through three rolls three times and kneading.

  The obtained composition was pressed at 120 ° C. for 15 minutes to obtain a heat radiation sheet having a thickness of 2 mm.

(Example 3)
100 parts by weight of polyoxyalkylene polymer (A-1), 100 parts by weight of TCP (tricresyl phosphate, manufactured by Daihachi Chemical), 400 parts by weight of aluminum hydroxide (manufactured by Wako Pure Chemical Industries), Nyper BW (benzoyl par) 1 part by weight of oxide, manufactured by Nippon Oil & Fats, 1 part by weight of Irganox 1010 (pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], manufactured by BASF), 0.5 part by weight of calcium stearate Parts were added, mixed thoroughly, and further kneaded by passing 3 times through 3 rolls to obtain a heat radiating sheet composition.

  The obtained composition was pressed at 120 ° C. for 15 minutes to obtain a heat radiation sheet having a thickness of 2 mm.

Example 4
A heat radiating sheet was obtained by the same method as in Example 1 except that the polyoxyalkylene polymer (A-2) was used instead of the polyoxyalkylene polymer (A-1).

(Example 5)
A heat radiating sheet was obtained in the same manner as in Example 2 except that the polyoxyalkylene polymer (A-2) was used instead of the polyoxyalkylene polymer (A-1).

(Example 6)
A heat radiating sheet was obtained in the same manner as in Example 3 except that the polyoxyalkylene polymer (A-2) was used instead of the polyoxyalkylene polymer (A-1).

(Comparative Example 1)
A cured product was obtained in the same manner as in Example 1 except that aluminum hydroxide was not used.

(Comparative Example 2)
100 parts by weight of polyoxyalkylene polymer (P-1), 100 parts by weight of TCP (tricresyl phosphate, manufactured by Daihachi Chemical), 400 parts by weight of aluminum hydroxide (manufactured by Wako Pure Chemical Industries), Irganox 1010 (pentaerythritol tetrakis) 1 part by weight of [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] manufactured by BASF) and 1 part by weight of dibutyltin dimethoxide are added, mixed thoroughly, and further passed through 3 rolls 3 times. And kneaded to obtain a heat radiating sheet composition.

  Next, it was poured into a sheet-like mold having a thickness of about 2 mm.

(Curable)
In Examples 1 to 6 and Comparative Example 1, the curability of the composition was examined by touching the surface of the cured product with the tip of a spatula immediately after the heating press. The evaluation was “◯” if the composition did not adhere to the spatula, and “x” if it adhered.

  In Comparative Example 2, the curability of the composition was examined by touching the surface of the cured product with the tip of a spatula 1 hour after pouring the composition into a sheet form. The evaluation was “◯” if the composition did not adhere to the spatula, and “x” if it adhered.

(Thermal conductivity)
Using a 30 mL glass bottle, cover the portions other than the bottle mouth with the sheets obtained in Examples 1 to 6 and Comparative Examples 1 and 2, add 20 mL of 100 ° C. water, and leave it in a constant temperature room at 23 ° C. Then, after 5 minutes, the thermal conductivity was evaluated by touching with a hand. The evaluation was “◯” if it felt warm and “x” if it felt hot.

  Table 1 shows the blending amount of the composition, and the results of curability and thermal conductivity.

  Although the composition for thermal radiation sheets of Examples 1-6 showed high sclerosis | hardenability, the thermal radiation sheet obtained from this composition showed favorable heat dissipation. Since the composition for heat radiating sheets of the present invention exhibits high curability, it can be said that productivity is improved as compared with the conventional moisture curable heat radiating sheet composition.

Claims (22)

General formula (1):
^{-Z-C (= O) -C} (R 1) = CH 2 (1)
(Wherein R ¹ is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and Z is a divalent organic group.) A number average having one or more substituents in the molecule on average. A heat radiating sheet composition comprising a polyoxyalkylene polymer (A) having a molecular weight of 3,000 or more, an initiator (B), and a heat conductive filler (C). The composition for heat dissipation sheets according to claim 1, wherein Z in the general formula (1) is an oxygen atom. Z in the general formula (1) is the general formula (2):
—NH—C (═O) —O—R ² —O— (2)
The composition for heat-radiating sheets according to claim 1, wherein R ² is a group represented by the formula (wherein R ² is a divalent hydrocarbon group). Z in the general formula (1) is the general formula (3):
—O—C (═O) —NH—R ² —O— (3)
The composition for heat-radiating sheets according to claim 1, wherein R ² is the same as defined above. The polyoxyalkylene polymer (a) in which the substituent represented by the general formula (1) has a hydroxyl group and the general formula (4):
^{O = C = N-R 2} -O-C (= O) -C (R 1) = CH 2 (4)
(Wherein R ¹ and R ² are the same as above) obtained by reacting the isocyanate compound (D) in the presence of dibutyltin (mercapto ester) (E). The composition for heat dissipation sheets of description. Radiation sheet composition according to any one of claims 1 5 R ¹ is a hydrogen atom. Radiation sheet composition according to any one of claims 3 R ² is an ethylene group 6. The composition for heat dissipation sheets according to any one of claims 1 to 7, wherein the polyoxyalkylene polymer (A) is a polyoxypropylene polymer. The composition for heat dissipation sheets of any one of Claim 1 to 8 containing the monomer and / or oligomer which have a radically polymerizable substituent. The composition for heat dissipation sheets of any one of Claim 1 to 9 containing the monomer and / or oligomer which have an anionically polymerizable substituent. The composition for heat dissipation sheets of any one of Claim 1 to 10 containing the monomer and / or oligomer which have a (meth) acryloyl group. The composition for heat-radiating sheets according to claim 11, further comprising a monomer and / or an oligomer having a (meth) acryloyl group and having a number average molecular weight of 5,000 or less. The composition for heat-radiating sheets according to any one of claims 1 to 12, wherein the initiator (B) is a photopolymerization initiator and / or a thermal polymerization initiator. The composition for heat-radiating sheets according to any one of claims 1 to 12, wherein the initiator (B) is a redox initiator. The heat conductive filler (C) is at least one selected from metal oxide, metal nitride, metal carbide, metal hydroxide, crystalline silica, organic polymer fired product, and nitrogen carbide. 14. The composition for heat dissipation sheets of any one of 14. The composition for heat-radiating sheets according to claim 15, wherein the thermally conductive filler (C) is at least one selected from aluminum oxide, boron nitride, aluminum nitride, and aluminum hydroxide. The composition for heat-radiating sheets according to any one of claims 1 to 16, wherein the volume ratio of the thermally conductive filler (C) is 25% by volume or more in the entire composition. The composition for heat dissipation sheets of any one of Claim 1 to 17 containing an organic carboxylic acid compound (F). The composition for heat-radiating sheets according to claim 18, wherein the organic carboxylic acid compound (F) is a stearic acid compound. The composition for heat-radiating sheets according to claim 19, wherein the organic carboxylic acid compound (F) is a stearic acid metal salt. The composition for heat-radiating sheets according to claim 20, wherein the organic carboxylic acid compound (F) is at least one selected from lead stearate, zinc stearate, and calcium stearate. A heat dissipating sheet obtained by curing the heat dissipating sheet composition according to claim 1.