JP2007277301A - New copolymer composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copolymer composition excellent in heat conductivity, attaching property and calendar-forming processability and its resin sheet excellent in heat radiating property by using the same. <P>SOLUTION: This copolymer composition is characterized by containing 5 to 35 mass% total amount of a styrene-based soft resin consisting of (1) a hydrogenated copolymer obtained by hydrogenating a copolymer consisting of a conjugated diene and a vinyl aromatic compound and/or (2) a modified hydrogenated copolymer obtained by adding hydrogen to the copolymer consisting of the conjugated diene and vinyl aromatic compound and bonding at least one functional group, and (3) 65 to 95 mass% zinc oxide characterized by consisting of a core part and needle like crystals extending to different 4 axial directions from the core part, and also containing (4) 0.01 to 5.0 pts.mass acrylic resin based on 100 pts.mass total of the components (1) to (3). <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention has excellent heat conductivity and heat transfer direction selectivity in order to dissipate heat generated from parts such as electronic devices in any direction, and further, there is no sheet breakage or thickness unevenness during calendering processing. The present invention relates to a copolymer composition excellent in calendar molding processability and a resin sheet having heat transfer direction selectivity.

  Conventionally, with the spread of digital home appliances, there is an increasing demand for higher speed and higher functionality of electrical components and electronic devices. However, in these electronic components and electronic devices, electronic elements such as LSIs and CPUs that perform electronic control have increased power consumption due to an increase in the degree of integration of computers and an increase in operation speed. Therefore, heat dissipation measures are indispensable. As a heat dissipation measure in general electronic devices, a heat sink or the like is attached, and the heat sink is forcibly cooled by a cooling fan or the like. In small devices such as notebook personal computers and electronic components that are mounted with high density, the space for installing a cooling fan is restricted, so the heating element and the cooling component such as a heat sink are placed apart via a heat transfer path. There is a case. A metal or resin heat radiating sheet is used for the heat transfer path connecting the two, but in order to efficiently radiate heat, a heat radiating sheet having selectivity in the heat transfer direction has been desired.

So far, heat dissipation sheets have been used in which a material based on silicone rubber or silicone gel sheet is filled with a filler having relatively high thermal conductivity. A sheet in which a thermoplastic elastomer is highly filled with a heat conductive filler is also known.
However, these were not things that transfer heat in a certain direction.
For example, a resin composition has been proposed in which a hydrogenated copolymer obtained by hydrogenating a copolymer comprising a conjugated diene and a vinyl aromatic compound is filled with zinc oxide and a fatty acid. This is for the purpose of improving the mechanical strength of the material, the filling amount of zinc oxide is 50% by weight or less, and there is no description about heat dissipation (for example, see Patent Document 1).

Moreover, the composition which adds fatty acid ester and a montanate to the composition which made the thermoplastic resin contain the high concentration filler is disclosed. This is for the purpose of improving the water absorption of the filler and improving the productivity of the extruder, and there is no description regarding the heat dissipation and the selectivity in the heat transfer direction (see, for example, Patent Document 2).
Furthermore, a resin composition in which a high-concentration heat conductive filler is filled in a styrene elastomer is disclosed. This is intended to soften the composition by adding oil to the styrenic elastomer, but there is no description about the heat transfer direction selectivity and moldability of the composition (for example, patent documents). See 3 and 4.).
JP 2003-277560 A Japanese Patent Laying-Open No. 2005-289819 JP 2002-121354 A JP 2004-146106 A

  The present invention has been made in order to solve the problems of the heat conductive material as described above, and is a heat transfer copolymer composition having excellent heat conductivity, heat transfer direction selectivity, and calendar molding processability. Another object of the present invention is to provide a resin sheet having heat transfer direction selectivity using the same.

  The present invention relates to a composition comprising a hydrogenated copolymer obtained by adding hydrogen to a copolymer comprising a conjugated diene and a vinyl aromatic compound, zinc oxide, and a fatty acid, and has a specific vinyl aromatic compound content. A hydrogenated copolymer or a modified hydrogenated copolymer having a vinyl aromatic compound polymer block content in a specific range, a special shape, that is, a core portion, and a four-axis direction from the core portion. It has been found that the above problem can be effectively solved by zinc oxide, which is an elongated needle crystal, and an acrylic resin, and the present invention has been completed.

That is, the present invention
1. Hydrogenated copolymer (1) satisfying the following (a) to (d) by adding hydrogen to a copolymer comprising a conjugated diene and a vinyl aromatic compound and / or a copolymer comprising a conjugated diene and a vinyl aromatic compound. 5 to 35% by mass of a styrenic soft resin comprising a modified hydrogenated copolymer (2) formed by adding hydrogen to a polymer and satisfying the following (a) to (d) that binds at least one functional group: Acrylic resin (based on zinc oxide (3) 65-95 mass% and components (1)-(3) 100 mass parts, which are needle-like crystals extending in different four-axis directions from the core, and the core (100). 4) A copolymer composition comprising 0.01 to 5.0 parts by mass,
(A) The content of the vinyl aromatic compound in the component (1) and / or (3) exceeds 50% by mass and is 90% by mass or less,
(B) The amount of the vinyl aromatic compound polymer block in the component (1) and / or (3) is 40% by mass or less,
(C) The weight average molecular weight of the hydrogenated copolymer of the component (1) and / or (3) is 50,000 to 1,000,000,
(D) 10% or more of the double bond based on the conjugated diene compound in the component (1) and / or (3) is hydrogenated.
2. 2. The component according to 1 above, wherein the component (2) is bonded to at least one atomic group having at least one functional group selected from a hydroxyl group, an epoxy group, an amino group, a silanol group, and an alkoxysilane group. Polymer composition,
3. The copolymer composition according to the above 1 or 2, wherein the amount of the vinyl aromatic compound polymer block in the component (1) and / or the component (2) is less than 10% by mass,
4). The copolymer composition according to 1 or 2 above, wherein the amount of the vinyl aromatic compound polymer block in the component (1) and / or the component (2) is 10 to 40% by mass,
5). 5. The copolymer according to any one of 1 to 4 above, wherein the component (1) and / or the component (2) is a hydrogenated product of a copolymer having at least one structure selected from the following general formula Composition,
(I) B
(B) B-A
(C) B-A-B
(D) (BA) _m -X
(E) (BA) _n- X-A _p
(Here, B is a random copolymer block of a conjugated diene and a vinyl aromatic compound, A is a vinyl aromatic compound polymer block, m is an integer of 2 or more, and n and p are each 1) (It is an integer above. X represents a coupling agent residue.)
6). The copolymer composition according to any one of claims 1 to 5, wherein the component (2) is bonded to at least one atomic group having at least one functional group selected from the following. ,

(In the above formula, R ^{1 to} R ⁴ are hydrogen or a hydrocarbon group having 1 to 24 carbon atoms, or a functional group selected from a hydroxyl group, an epoxy group, an amino group, a silanol group, and an alkoxysilane group. A hydrocarbon group having 24. R ⁵ is a hydrocarbon chain having 1 to 48 carbon atoms, or a hydrocarbon chain having 1 to 48 carbon atoms having a functional group selected from a hydroxyl group, an epoxy group, an amino group, a silanol group, and an alkoxysilane group. In addition, in the hydrocarbon groups of R ^{1 to} R ⁴ and the hydrocarbon chain of R ⁵ , elements such as oxygen, nitrogen, and silicon are bonded in a bonding mode other than a hydroxyl group, an epoxy group, a silanol group, and an alkoxysilane group. R ⁶ is hydrogen or an alkyl group having 1 to 8 carbon atoms.)
7). Component (2) is a modified copolymer obtained by adding a functional group-containing modifier to the living terminal of a copolymer comprising a conjugated diene and a vinyl aromatic compound obtained using an organolithium compound as a polymerization catalyst. The copolymer composition according to any one of 1 to 6 above, wherein the copolymer composition is hydrogenated,
8). A resin sheet having heat transfer direction selectivity formed by molding the copolymer composition according to any one of the above 1 to 7 into a sheet shape,
Is to provide.

  According to the present invention, a copolymer composition excellent in heat conductivity and heat transfer direction selectivity, sheet breakage at the time of calender molding, and molding processability with little thickness unevenness, and a resin excellent in heat dissipation using the same Sheets can now be provided.

The hydrogenated copolymer of component (1) or the modified hydrogenated copolymer of component (2) (hereinafter sometimes referred to as hydrogenated copolymer) is a conjugated diene and a vinyl aromatic compound. A hydrogenated copolymer obtained by adding hydrogen to a copolymer comprising
In the present invention, the content of the vinyl aromatic compound in the hydrogenated copolymer or the like is more than 50% by mass and 90% by mass or less, preferably more than 50% by mass and 88% by mass or less, more preferably more than 50% by mass and 86% by mass. It is below mass%. Use of a vinyl aromatic compound having a content specified by the present invention provides a copolymer composition of the present invention that is highly flexible and excellent in wear resistance, scratch resistance, strength, and the like. Is necessary for. The hydrogenated copolymer of the present invention may contain a hydrogenated vinyl aromatic compound. This hydrogenated vinyl aromatic compound is also contained in the hydrogenated copolymer. It shall be included in the vinyl aromatic compound content. In the present invention, the content of the vinyl aromatic compound in the hydrogenated copolymer or the like may be grasped by the content of the vinyl aromatic compound in the copolymer before hydrogenation.

  In the hydrogenated copolymer and the like used in the present invention, the content of the vinyl aromatic compound polymer block is 40% by mass or less, preferably 3 to 40% by mass, and more preferably 5 to 35% by mass. In the present invention, when it is desired to obtain a composition having good flexibility, the content of the vinyl aromatic compound polymer block is less than 10% by mass, preferably less than 8% by mass, more preferably less than 5% by mass. Encouraged. Moreover, when obtaining what is excellent in blocking resistance as a hydrogenated copolymer etc. when obtaining the copolymer composition of this invention, a vinyl aromatic compound polymer block is 10-40 mass%, Preferably it is 13 It is encouraged to be -37% by weight, more preferably 15-35% by weight.

The vinyl aromatic compound polymer block content is measured by, for example, a method in which osmium tetroxide is used as a catalyst to oxidatively decompose a copolymer before hydrogenation with tertiary butyl hydroperoxide (IM KOLTHOFF, et al., J. Polym.Sci. 1,429 (1946)) weight of vinyl aromatic hydrocarbon polymer block component (however, the vinyl aromatic hydrocarbon polymer component having an average degree of polymerization of about 30 or less is Can be obtained from the following equation.
Vinyl aromatic hydrocarbon block weight (% by mass)
= {(Vinyl aromatic hydrocarbon polymer block weight in copolymer before hydrogenation / weight of copolymer before hydrogenation)} × 100
In the present invention, the block ratio of the vinyl aromatic compound in the hydrogenated copolymer or the like (the block ratio is the ratio of the content of the vinyl aromatic compound polymer block to the total vinyl aromatic compound amount in the copolymer). Is less than 50% by weight, preferably 20% by weight or less, and more preferably 18% by weight or less, in order to obtain a more flexible composition.

The weight average molecular weight of the hydrogenated copolymer or the like used in the present invention is 5 to 1,000,000, preferably 100 to 800,000, and more preferably 13 to 500,000. When using a hydrogenated copolymer having a vinyl aromatic compound polymer block content of 10 to 40% by weight, the weight average molecular weight is more than 100,000 and less than 500,000, preferably 130,000 to 400,000. More preferably, 150,000 to 300,000 is encouraged. When the weight average molecular weight is less than 50,000, the mechanical strength is inferior, and when it exceeds 1,000,000, the molding processability is inferior.
In the present invention, the molecular weight distribution (Mw / Mn) (ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn)) of the hydrogenated copolymer or the like is 1.01 to 8. 0 is preferred, more preferably 1.1 to 6.0, and even more preferably 1.1 to 5.0. The shape of the molecular weight distribution measured by gel permeation chromatography (GPC) is not particularly limited, and may have a polymodal molecular weight distribution having two or more peaks (peaks), but there is only one peak. Hydrogenated copolymers having a monomodal molecular weight distribution are preferred.

The hydrogenated copolymer used in the present invention is a hydrogenated product of a copolymer comprising a conjugated diene and a vinyl aromatic compound, and is a total hydrogen of unsaturated double bonds based on the conjugated diene compound in the copolymer. The addition rate is 10% or more, preferably 20% or more, more preferably 30% or more. In particular, when obtaining a composition excellent in weather resistance, it is recommended that the hydrogenation rate is 75% or more, preferably 85% or more, more preferably 90% or more. When obtaining a vulcanized composition having good vulcanizate properties, it is recommended that the hydrogenation rate be 98% or less, preferably 95% or less, and more preferably 90% or less.
Furthermore, in the hydrogenated copolymer used in the present invention, when obtaining a composition having particularly excellent thermal stability, the hydrogenation rate of vinyl bonds is 85% or more, preferably 90% or more, more preferably 95. % Is encouraged.

Here, the hydrogenation rate of vinyl bonds refers to the proportion of vinyl bonds that have been hydrogenated among the vinyl bonds in the conjugated diene incorporated in the copolymer before hydrogenation.
The hydrogenation rate of the aromatic double bond based on the vinyl aromatic hydrocarbon in the copolymer is not particularly limited, but the hydrogenation rate is 50% or less, preferably 30% or less, more preferably 20%. The following is preferable.
The hydrogenated copolymer or the like used in the present invention is preferably a hydrogenated product having substantially no crystallization peak in the temperature range of −50 to 100 ° C. in the differential scanning calorimetry (DSC method). Here, substantially no crystallization peak exists in the temperature range of −50 to 100 ° C. when no peak due to crystallization appears in this temperature range or when a peak due to crystallization is observed. The crystallization peak calorific value in the crystallization is less than 3 J / g, preferably less than 2 J / g, more preferably less than 1 J / g, and particularly preferably no crystallization peak calorie.

In the present invention, the structure of the hydrogenated copolymer or the like is not particularly limited, and any structure can be used. However, what is particularly encouraged has at least one structure selected from the following general formulas (i) to (e). It is a hydrogenated product of a copolymer. The hydrogenated copolymer or the like used in the present invention may be an arbitrary mixture comprising a hydrogenated copolymer having a structure represented by the following general formulas (i) to (e). Further, a vinyl aromatic compound polymer may be mixed with a hydrogenated copolymer or the like.
(I) B
(B) B-A
(C) B-A-B
(D) (BA) _m -X
(E) (BA) _n- X-A _p
(Here, B is a random copolymer block of a conjugated diene and a vinyl aromatic compound, A is a vinyl aromatic compound polymer block, m is an integer of 2 or more, and n and p are each 1) (It is an integer above. X represents a coupling agent residue.)
In the general formula, the vinyl aromatic hydrocarbons in the random copolymer block B may be distributed uniformly or in a tapered shape. In the copolymer block B, a plurality of portions where vinyl aromatic hydrocarbons are uniformly distributed and / or a portion where they are distributed in a tapered shape may coexist. M is 2 or more, preferably an integer of 2 to 10, and n and p are each 1 or more, preferably an integer of 1 to 10.

In the present invention, it is recommended that the difference between the maximum value and the minimum value of the vinyl bond content in the copolymer chain before hydrogenation is less than 10%, preferably 8% or less, more preferably 6% or less. Is done. The vinyl bonds in the copolymer chain may be distributed uniformly or in a tapered shape. Here, the difference between the maximum value and the minimum value of the vinyl bond content is the maximum value and the minimum value of the vinyl amount determined by the polymerization conditions, that is, the type and amount of the vinyl amount adjusting agent and the polymerization temperature.
The difference between the maximum value and the minimum value of the vinyl bond content in the conjugated diene polymer chain can be controlled by, for example, the polymerization temperature during the polymerization of the conjugated diene or the copolymerization of the conjugated diene and the vinyl aromatic compound. When the type and amount of a vinyl amount modifier such as a tertiary amine compound or an ether compound is constant, the vinyl bond content incorporated into the polymer chain during polymerization is determined by the polymerization temperature. Therefore, a polymer polymerized isothermally becomes a polymer in which vinyl bonds are uniformly distributed. In contrast, polymers polymerized at elevated temperatures become polymers with different vinyl bond contents, such as high vinyl bond content in the initial (polymerization at low temperature) and low vinyl bond content in the latter half (polymerization at high temperature). . A hydrogenated copolymer having a specific structure can be obtained by adding hydrogen to the copolymer having such a structure.

In the present invention, the content of the vinyl aromatic compound can be known using an ultraviolet spectrophotometer, an infrared spectrophotometer, a nuclear magnetic resonance apparatus (NMR), or the like. The amount of the vinyl aromatic compound polymer block can be known by the KOLTHOFF method described above. The vinyl bond content based on the conjugated diene in the copolymer before hydrogenation can be known using an infrared spectrophotometer (for example, the Hampton method), a nuclear magnetic resonance apparatus (NMR), or the like. Moreover, the hydrogenation rate of a hydrogenated copolymer etc. can be known using an infrared spectrophotometer, a nuclear magnetic resonance apparatus (NMR), etc.
In the present invention, the molecular weight of the hydrogenated copolymer or the like is measured by gel permeation chromatography (GPC), and the molecular weight of the peak of the chromatogram is obtained from a calibration curve obtained from the measurement of commercially available standard polystyrene ( The weight average molecular weight determined using the peak molecular weight of standard polystyrene). Similarly, the molecular weight distribution of a hydrogenated copolymer or the like can be determined from measurement by GPC.

In the present invention, the conjugated diene is a diolefin having a pair of conjugated double bonds, such as 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3. -Butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene and the like, and particularly common ones include 1,3-butadiene and isoprene. These may be used alone or in combination of two or more.
Examples of the vinyl aromatic compound include styrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylethylene, N, N-dimethyl-p-aminoethylstyrene, N, N-diethyl- Examples thereof include p-aminoethylstyrene, and these may be used alone or in combination of two or more.

  In the present invention, the microstructure of the conjugated diene portion (ratio of cis, trans, vinyl) in the copolymer before hydrogenation can be arbitrarily changed by using a polar compound or the like described later, and is not particularly limited. Generally, when 1,3-butadiene is used as the conjugated diene, the 1,2-vinyl bond is 5 to 80%, preferably 10 to 60%. When isoprene is used as the conjugated diene, When butadiene and isoprene are used in combination, the total amount of 1,2-vinyl bonds and 3,4-vinyl bonds is generally recommended to be 3 to 75%, preferably 5 to 60%. In the present invention, the total amount of 1,2-vinyl bonds and 3,4-vinyl bonds (however, when 1,3-butadiene is used as the conjugated diene, the amount of 1,2-vinyl bonds) is Hereinafter referred to as vinyl bond content.

In the present invention, the copolymer before hydrogenation is obtained, for example, by anion living polymerization using an initiator such as an organic alkali metal compound in a hydrocarbon solvent. Examples of the hydrocarbon solvent include aliphatic hydrocarbons such as n-butane, isobutane, n-pentane, n-hexane, n-heptane and n-octane, and alicyclic carbonization such as cyclohexane, cycloheptane and methylcycloheptane. Hydrogen, and aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene.
Further, as the initiator, an aliphatic hydrocarbon alkali metal compound, an aromatic hydrocarbon alkali metal compound, an organic amino alkali, which are generally known to have anionic polymerization activity with respect to a conjugated diene compound and a vinyl aromatic compound. Examples of the alkali metal include lithium, sodium, and potassium. Suitable organic alkali metal compounds are aliphatic and aromatic hydrocarbon lithium compounds having 1 to 20 carbon atoms, a compound containing one lithium in one molecule, and a dilithium compound containing a plurality of lithiums in one molecule , Trilithium compounds, and tetralithium compounds.

  Specifically, n-propyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, n-pentyllithium, n-hexyllithium, benzyllithium, phenyllithium, tolyllithium, diisopropenylbenzene and sec- A reaction product of butyllithium, a reaction product of divinylbenzene, sec-butyllithium, and a small amount of 1,3-butadiene can be used. Further, 1- (t-butoxy) propyllithium disclosed in US Pat. No. 5,708,092 and a lithium compound in which 1 to several molecules of isoprene monomer are inserted to improve its solubility, British Patent 2 Siloxy group-containing alkyllithium such as 1- (t-butyldimethylsiloxy) hexyllithium disclosed in US Pat. No. 5,241,239, amino group-containing alkyl disclosed in US Pat. No. 5,527,753 Aminolithiums such as lithium, diisopropylamidolithium and hexamethyldisilazide lithium can also be used.

In the present invention, when an organic alkali metal compound is used as a polymerization initiator and a conjugated diene compound and a vinyl aromatic compound are copolymerized, a vinyl bond (1, 2 or 3, 4 bond) resulting from the conjugated diene compound incorporated into the polymer A tertiary amine compound or an ether compound can be added as an adjusting agent in order to adjust the content of and to adjust the random copolymerizability between the conjugated diene compound and the vinyl aromatic compound. The tertiary amine compound is represented by the general formula R ¹ R ² R ³ N (where R ¹ , R ² and R ³ are hydrocarbon groups having 1 to 20 carbon atoms or a tertiary amino group. ).
For example, trimethylamine, triethylamine, tributylamine, N, N-dimethylaniline, N-ethylpiperidine, N-methylpyrrolidine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′— Tetraethylethylenediamine, 1,2-dipiperidinoethane, trimethylaminoethylpiperazine, N, N, N ′, N ″, N ″ -pentamethylethylenetriamine, N, N′-dioctyl-p-phenylenediamine and the like. .

The ether compound is selected from linear ether compounds and cyclic ether compounds, and the linear ether compound is an ethylene glycol such as dimethyl ether, diethyl ether, diphenyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether or the like. And dialkyl ether compounds of diethylene glycol such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, and diethylene glycol dibutyl ether.
Cyclic ether compounds include tetrahydrofuran, dioxane, 2,5-dimethyloxolane, 2,2,5,5-tetramethyloxolane, 2,2-bis (2-oxolanyl) propane, and alkyl ethers of furfuryl alcohol. Etc.

  In the present invention, the method of copolymerizing a conjugated diene compound and a vinyl aromatic compound using an organic alkali metal compound as a polymerization initiator may be batch polymerization, continuous polymerization, or a combination thereof. In particular, a continuous polymerization method is recommended for adjusting the molecular weight distribution to a preferable appropriate range. The polymerization temperature is generally 0 ° C. to 180 ° C., preferably 30 ° C. to 150 ° C. The time required for the polymerization varies depending on the conditions, but is usually within 48 hours, particularly preferably 0.1 to 10 hours. The polymerization atmosphere is preferably an inert gas atmosphere such as nitrogen gas. The polymerization pressure is not particularly limited as long as the polymerization pressure is in a range sufficient to maintain the monomer and solvent in a liquid phase within the above polymerization temperature range. Furthermore, care must be taken so that impurities that inactivate the catalyst and living polymer, such as water, oxygen, and carbon dioxide, do not enter the polymerization system.

In the present invention, a coupling reaction can be performed by adding a necessary amount of a bifunctional or higher functional coupling agent at the end of the polymerization. Any known bifunctional coupling agent may be used and is not particularly limited. Examples thereof include dihalogen compounds such as dimethyldichlorosilane and dimethyldibromosilane, and acid esters such as methyl benzoate, ethyl benzoate, phenyl benzoate, and phthalates.
Further, any known trifunctional or higher polyfunctional coupling agent may be used without any particular limitation. For example, polyalcohols having three or more valences, polyepoxy compounds such as epoxidized soybean oil, diglycidyl bisphenol A, general formula R _4-n SiX _n (where R is a hydrocarbon group having 1 to 20 carbon atoms, X halogen, n represents a halogenated silicon compound represented by 3 or 4), such as methyl silyl trichloride, t- butyl silyl trichloride, silicon tetrachloride and the like of these bromides formula R _{4-n SiX n (provided} that , R is a hydrocarbon group having 1 to 20 carbon atoms, X is a halogen, n is a halogenated compound represented by 3 or 4), for example, a polyvalent halogen such as methyltin trichloride, t-butyltin trichloride, tin tetrachloride Compounds. Dimethyl carbonate or diethyl carbonate can also be used.

  In the present invention, a modified copolymer in which a polar group-containing atomic group is bonded to at least one polymer chain of the polymer can be used as the copolymer. Examples of the polar group-containing atomic group include a hydroxyl group, a carboxyl group, a carbonyl group, a thiocarbonyl group, an acid halide group, an acid anhydride group, a carboxylic acid group, a thiocarboxylic acid group, an aldehyde group, a thioaldehyde group, and a carboxylic acid ester group. Amide group, sulfonic acid group, sulfonic acid ester group, phosphoric acid group, phosphoric acid ester group, amino group, imino group, nitrile group, pyridyl group, quinoline group, epoxy group, thioepoxy group, sulfide group, isocyanate group, iso Examples thereof include an atomic group containing at least one polar group selected from a thiocyanate group, a silicon halide group, a silanol group, an alkoxysilicon group, a tin halide group, an alkoxytin group, a phenyltin group and the like.

  The modified copolymer is obtained by reacting a compound having these polar group-containing atomic groups at the end of polymerization of the copolymer. As the compound having a polar group-containing atomic group, specifically, a modification treatment agent described in Japanese Patent Publication No. 4-39495 can be used. A preferred modified hydrogenated copolymer used as component (3) in the present invention is a bond of at least one atomic group having at least one functional group selected from a hydroxyl group, an epoxy group, an amino group, a silanol group, and an alkoxysilane group. The modified hydrogenated copolymer. Such a modified hydrogenated copolymer is obtained by adding a functional group-containing modifier to the living end of a copolymer obtained by the above-described method using an organolithium compound as a polymerization catalyst, thereby adding a hydroxyl group to the copolymer. Hydrogen is added to a modified product (hereinafter referred to as a modified copolymer) in which at least one atomic group having at least one functional group selected from an epoxy group, an amino group, a silanol group, and an alkoxysilane group is bonded. Can be obtained.

As another method for obtaining a modified copolymer, an organic alkali metal compound such as an organolithium compound is reacted (metalation reaction) with the copolymer before the modification, and the functional group-containing copolymer is added to the copolymer added with the organic alkali metal. Examples include a method in which a modifying agent is subjected to an addition reaction. Depending on the type of modifier, the hydroxyl group and amino group may generally be an organometallic salt at the stage of reaction of the modifier, but in that case, treatment with a compound having active hydrogen such as water or alcohol. By doing so, a hydroxyl group, an amino group, or the like can be obtained.
In the present invention, an atomic group preferable as an atomic group having at least one functional group selected from a hydroxyl group, an epoxy group, an amino group, a silanol group, and an alkoxysilane group includes an atomic group selected from those represented by the following general formula: It is done.

(In the above formula, R ^{1 to} R ⁴ are hydrogen or a hydrocarbon group having 1 to 24 carbon atoms, or a functional group selected from a hydroxyl group, an epoxy group, an amino group, a silanol group, and an alkoxysilane group. A hydrocarbon group having 24. R ⁵ is a hydrocarbon chain having 1 to 48 carbon atoms, or a hydrocarbon chain having 1 to 48 carbon atoms having a functional group selected from a hydroxyl group, an epoxy group, an amino group, a silanol group, and an alkoxysilane group. . Note hydrocarbon groups R1 to R4, and the hydrocarbon chain of R ^5, hydroxyl, epoxy group, silanol group, alkoxysilane group other than binding mode, oxygen, nitrogen, bound an element such as silicon R ⁶ is hydrogen or an alkyl group having 1 to 8 carbon atoms.)
In the present invention, it is used to obtain a modified hydrogenated copolymer in which at least one atomic group having at least one functional group selected from a hydroxyl group, an epoxy group, an amino group, a silanol group, and an alkoxysilane group is bonded. Examples of the modifying agent include the following.

  For example, tetraglycidylmetaxylenediamine, tetraglycidyl-1,3-bisaminomethylcyclohexane, tetraglycidyl-p-phenylenediamine, tetraglycidyldiaminodiphenylmethane, diglycidylaniline, diglycidylorthotoluidine, γ-glycidoxyethyltrimethoxy Silane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxybutyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltripropoxysilane, γ-glycidoxypropyltributoxy Examples include silane, γ-glycidoxypropyltriphenoxysilane, and γ-glycidoxypropylmethyldimethoxysilane.

  Γ-glycidoxypropylethyldimethoxysilane, γ-glycidoxypropylethyldiethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropylmethyldipropoxysilane, γ-glycidoxy Propylmethyldibutoxysilane, γ-glycidoxypropylmethyldiphenoxysilane, γ-glycidoxypropyldimethylmethoxysilane, γ-glycidoxypropyldiethylethoxysilane, γ-glycidoxypropyldimethylethoxysilane, γ-glycyl Sidoxypropyldimethylphenoxysilane, γ-glycidoxypropyldiethylmethoxysilane, and γ-glycidoxypropylmethyldiisopropeneoxysilane are exemplified.

Also, bis (γ-glycidoxypropyl) dimethoxysilane, bis (γ-glycidoxypropyl) diethoxysilane, bis (γ-glycidoxypropyl) dipropoxysilane, bis (γ-glycidoxypropyl) di Butoxysilane, bis (γ-glycidoxypropyl) diphenoxysilane, bis (γ-glycidoxypropyl) methylmethoxysilane, bis (γ-glycidoxypropyl) methylethoxysilane, bis (γ-glycidoxypropyl) ) Methylpropoxysilane, bis (γ-glycidoxypropyl) methylbutoxysilane, and bis (γ-glycidoxypropyl) methylphenoxysilane.
Further, tris (γ-glycidoxypropyl) methoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxymethyltrimethoxysilane, γ-methacryloxyethyltriethoxysilane, Examples include bis (γ-methacryloxypropyl) dimethoxysilane and tris (γ-methacryloxypropyl) methoxysilane.

  Β- (3,4-epoxycyclohexyl) ethyl-trimethoxysilane, β- (3,4-epoxycyclohexyl) ethyl-triethoxysilane, β- (3,4-epoxycyclohexyl) ethyl-tripropoxysilane, β- (3,4-epoxycyclohexyl) ethyl-tributoxysilane, β- (3,4-epoxycyclohexyl) ethyl-triphenoxysilane, β- (3,4-epoxycyclohexyl) propyl-trimethoxysilane, β- (3,4-epoxycyclohexyl) ethyl-methyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyl-ethyldimethoxysilane.

Β- (3,4-epoxycyclohexyl) ethyl-ethyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyl-methyldiethoxysilane, β- (3,4-epoxycyclohexyl) ethyl-methyldi Propoxysilane, β- (3,4-epoxycyclohexyl) ethyl-methyldibutoxysilane, β- (3,4-epoxycyclohexyl) ethyl-methyldiphenoxysilane, β- (3,4-epoxycyclohexyl) ethyl-dimethyl Examples include methoxysilane, β- (3,4-epoxycyclohexyl) ethyl-diethylethoxysilane.
Furthermore, β- (3,4-epoxycyclohexyl) ethyl-dimethylethoxysilane, β- (3,4-epoxycyclohexyl) ethyl-dimethylpropoxysilane, β- (3,4-epoxycyclohexyl) ethyl-dimethylbutoxysilane , Β- (3,4-epoxycyclohexyl) ethyl-dimethylphenoxysilane, β- (3,4-epoxycyclohexyl) ethyl-diethylmethoxysilane, β- (3,4-epoxycyclohexyl) ethyl-methyldiisopropeneoxy Examples include silane, 1,3-dimethyl-2-imidazolidinone, 1,3-diethyl-2-imidazolidinone, N, N′-dimethylpropylene urea, N-methylpyrrolidone, and the like.

A functional group selected from a hydroxyl group, an epoxy group, an amino group, a silanol group, and an alkoxysilane group by reacting the above modifier with the living end of the copolymer obtained by the above-described method using an organolithium compound as a polymerization catalyst. A modified copolymer in which the residue of the modifying agent to which the atomic group having at least one group is bonded is bonded.
In the present invention, the hydrogenated copolymer of component (1) or the modified hydrogenated copolymer of component (2) is obtained by hydrogenating the copolymer obtained before or obtained before hydrogenation. Is obtained. The hydrogenation catalyst is not particularly limited and is conventionally known (1) A supported heterogeneous hydrogenation in which a metal such as Ni, Pt, Pd, or Ru is supported on carbon, silica, alumina, diatomaceous earth, or the like. A catalyst, (2) a so-called Ziegler-type hydrogenation catalyst using an organic acid salt such as Ni, Co, Fe, Cr or a transition metal salt such as acetylacetone salt and a reducing agent such as organic aluminum, (3) Ti, Ru, A homogeneous hydrogenation catalyst such as a so-called organometallic complex such as an organometallic compound such as Rh or Zr is used.

  Specific examples of the hydrogenation catalyst include Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Patent Publication No. 63-4841, Japanese Patent Publication No. 1-337970, Japanese Patent Publication No. 1-53851, The hydrogenation catalyst described in Japanese Utility Model Publication No. 2-9041 can be used. A preferred hydrogenation catalyst is a mixture with a titanocene compound and / or a reducing organometallic compound. As the titanocene compound, compounds described in JP-A-8-109219 can be used. Specific examples thereof include (substitution) such as biscyclopentadienyl titanium dichloride and monopentamethylcyclopentadienyl titanium trichloride. Examples thereof include compounds having at least one ligand having a cyclopentadienyl skeleton, an indenyl skeleton, or a fluorenyl skeleton. Examples of the reducing organometallic compound include organic alkali metal compounds such as organolithium, organomagnesium compounds, organoaluminum compounds, organoboron compounds, and organozinc compounds.

The hydrogenation reaction is generally carried out in a temperature range of 0 to 200 ° C, more preferably 30 to 150 ° C. The pressure of hydrogen used for the hydrogenation reaction is 0.1 to 15 MPa, preferably 0.2 to 10 MPa, more preferably 0.3 to 5 MPa. The hydrogenation reaction time is usually 3 minutes to 10 hours, preferably 10 minutes to 5 hours. The hydrogenation reaction can be any of a batch process, a continuous process, or a combination thereof.
In the case of the modified hydrogenated copolymer of component (2) in the present invention, a partially unmodified hydrogenated copolymer may be mixed in the modified hydrogenated copolymer. It is recommended that the proportion of the unmodified hydrogenated copolymer mixed in the modified hydrogenated copolymer of component (2) is 70% by mass or less, preferably 60% by mass or less, more preferably 50% by mass or less. Is done. The solution of the hydrogenated copolymer or modified hydrogenated copolymer obtained as described above removes the catalyst residue, if necessary, and removes the hydrogenated copolymer or modified hydrogenated copolymer from the solution. Can be separated. Solvent separation methods include, for example, a method in which a polar solvent that is a poor solvent for a polymer such as acetone or alcohol is added to the solution after hydrogenation to precipitate and recover the polymer, a hydrogenated copolymer or modified water Examples thereof include a method in which the additive copolymer solution is poured into hot water with stirring and the solvent is removed by steam stripping, or a method in which the solvent is distilled off by directly heating the polymer solution.

In addition, stabilizers such as various phenol stabilizers, phosphorus stabilizers, sulfur stabilizers and amine stabilizers should be added to the hydrogenated copolymer or modified hydrogenated copolymer used in the present invention. Can do.
The core and zinc oxide (3), which is a needle-like crystal extending in different four-axis directions from the core, used in the present invention have a core, and the four-axis directions differ from the core in a tetrapot shape. For example, “trade name: Panatetra” manufactured by Matsushita Amtech Co., Ltd. and the like can be mentioned.
In the zinc oxide, it is preferable that the diameter of the core part of the needle crystal part is 0.7 to 14 μm, and the length from the base part to the tip of the needle crystal part is 3 to 200 μm. More preferably, the diameter of the base of the acicular crystal part is 1 to 14 μm, and the length from the base to the tip of the acicular crystal part is 10 to 200 μm.

In the zinc oxide (3), the angle formed by the tip of one needle crystal, the core, and the tip of another needle crystal is preferably 109.5 degrees.
The zinc oxide can also include zinc oxide surface-treated with a coupling agent in the present invention, and the coupling agent used here is preferably a silane coupling agent, a titanate coupling agent, or an aluminum coupling agent. It is done.
In the adhesive copolymer composition of the present invention, acicular zinc oxide may be present, but this is a breakage of acicular crystal parts extending in multiple directions of tetrapotted zinc oxide. Therefore, the main characteristics of the present invention are not impaired.

The acrylic resin (4) used in the present invention is specifically a polymer or copolymer of at least one compound selected from the group consisting of (meth) acrylic acid alkyl esters. Examples of (meth) acrylic acid alkyl esters include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, and dodecyl methacrylate. Any copolymer can be used as long as it is a copolymer obtained by polymerizing these compounds alone or in combination of two or more.
Preferred is a copolymer of methyl methacrylate and ethyl acrylate. Moreover, the graft copolymer obtained by making a (meth) acrylic-acid alkylester into a main component can also be used for the acrylic rubber particle obtained by superposing | polymerizing an acrylic-acid alkylester.

In the copolymer composition of the present invention, a styrene-based soft resin comprising a hydrogenated copolymer (1) and / or a modified hydrogenated copolymer (2), a core part, and the core part extend in different four-axis directions. The blending ratio of zinc oxide (3), which is a needle crystal, and acrylic resin (4) is 5 to 35% by mass of styrene-based soft resin composed of component (1) and / or component (2) and the core. And acrylic resin (4) with respect to zinc oxide (3) 65 to 95% by mass, which is needle-like crystals extending in different four-axis directions from the core, and 100 parts by mass of the components (1) to (3). ) 0.01 to 5.0 parts by mass.
The component (1) and / or the component (2) is 5 to 35% by mass based on the total amount of the components (1) to (3), so that the thermal conductivity, heat transfer direction selectivity, It is excellent in calendar molding processability. When the content of the component (3) is less than 65% by mass, the composition has insufficient heat conductivity, which is not preferable. When it exceeds 95% by mass, the heat transfer direction selectivity and the calender molding processability of the composition are poor. It is sufficient and not preferable.
The ratio of the component (3) to the total amount of the component (1) and / or the component (2) is from 200 to 100 parts by mass of the component (1) and / or the component (2). 900 parts by mass is preferable from the viewpoint of the thermal conductivity, heat transfer direction selectivity, and calendar molding processability of the composition. More preferably, it is 300-800 mass parts, Especially preferably, it is 360-750 mass parts.

A preferred range is 6-25% by mass of component (1) and / or component (2) and 75-94% by mass of component (3), and a more preferred range is the sum of component (1) and / or component (2). The amount is 7 to 22% by mass and the component (3) is 78 to 93% by mass.
By adding a small amount of the acrylic resin (4) to the copolymer composition of the present invention, the heat transfer direction selectivity of the composition is surprisingly expressed, and when processed into a sheet or the like, the flow of the sheet There is a difference in the value of thermal conductivity between the direction and the direction perpendicular to the flow direction.
It is 0.01-5.0 mass parts of acrylic resin (4) with respect to 100 mass parts of components (1)-(3). When the content of component (4) is less than 0.01 parts by mass, the composition has insufficient heat conductivity, heat transfer direction selectivity, and calendar molding processability, and when it exceeds 5.0 parts by mass, the composition This is not preferable because the heat dissipation of the material may be insufficient. The preferable range of the component (4) is 0.05 to 2.0 parts by mass of the component (4) with respect to 100 parts by mass of the total amount of the components (1) to (3), and the more preferable range is 0. 0.08 to 0.4 parts by mass.

The copolymer composition of this invention can mix | blend additives, such as a fatty acid, a fatty acid metal salt, and fatty acid ester, as needed within the range which does not impair the objective of this invention. These compounding quantities are 0.01-5.0 mass parts in total with respect to 100 mass parts of component (1)-(3), Preferably it is 0.05-2.0 mass parts, More preferably, it is 0.00. It is 08-0.4 mass part.
Paraffinic oil can be added to the styrenic soft resin component of the present invention as needed within a range not impairing the object of the present invention. The blending amount of the paraffinic oil is 1 to 300 parts by mass, preferably 1 to 200 parts by mass, more preferably 1 with respect to 100 parts by mass of the styrenic soft resin composed of the component (1) and / or the component (2). It is -140 mass parts, Most preferably, it is 1-100 mass parts.

The paraffinic oil used in the present invention is a lubricating base oil obtained by hydrogenating a petroleum fraction or residual oil and purifying it or by decomposing it. The paraffinic oil of the present invention has a kinematic viscosity at 40 ° C. of 100 mm ² / sec or more, preferably 100 to 10,000 mm ² / sec, more preferably 200 to 5000 mm ² / sec. As such paraffinic oil, for example, NA Solvent manufactured by Nippon Oil & Fats Co., Ltd., PW-90 and PW-380 manufactured by Idemitsu Kosan Co., Ltd., IP-Solvent 2835 manufactured by Idemitsu Petrochemical Co., Ltd., Sanko Chemical Co., Ltd. Examples thereof include neothiozole and the like.
Moreover, the copolymer composition of this invention can add a heat conductive filler as needed within the range which does not impair the objective of this invention.

The thermally conductive filler used in the present invention has a thermal conductivity of 10 to 400 W / m · other than zinc oxide (3) which is a needle-like crystal extending in a different four-axis direction from the core and the core. The filler is in the range of K, and examples thereof include metal powder, metal nitride, metal carbide, metal oxide, graphitized hydrocarbon, natural graphite, and spherical graphite particles. Examples of the metal powder include gold, silver, copper, and aluminum.
Examples of the metal nitride include boron nitride, silicon nitride, and aluminum nitride. Examples of the metal carbide include silicon carbide. Examples of the metal oxide include zinc oxide, aluminum oxide, magnesium oxide, and silicon oxide.

Moreover, the shape of these heat conductive fillers may be fibrous and / or non-fibrous (plate-like, scale-like, granular, irregular shape, spherical).
The blending amount of the thermally conductive filler is preferably within a range not exceeding 50 parts by mass, more preferably 100 parts by mass of the styrene-based soft resin comprising the component (1) and / or the component (2) of the present invention. It is the range which does not exceed 40 mass parts, More preferably, it is the range which does not exceed 30 mass parts.
The copolymer composition of the present invention may contain, as necessary, other additives such as a flame retardant, a flame retardant aid, an antioxidant, and an ultraviolet absorber as long as the object of the present invention is not impaired. Additives such as stabilizers, antistatic agents, light stabilizers, anti-aging agents, and coloring agents can be blended.

These additives may be added at the time of kneading, or may be preliminarily included in the copolymer at the time of producing the hydrogenated copolymer or the modified hydrogenated copolymer. The addition amount of these additives is in a range not exceeding 100 parts by mass in total with respect to 100 parts by mass of the total amount of the copolymer composition of the present invention.
The copolymer composition of the present invention can be easily produced by conventional known techniques such as Brabender, kneader, Banbury mixer, twin-screw or single-screw extruder, and the obtained heat transfer copolymer composition is generally used. It can be molded by a known molding method such as injection molding, injection press molding, or gas injection molding.
As a molding method for obtaining the copolymer composition as a sheet, it can be molded by extrusion sheet molding, calender molding, roll molding, press molding or the like after kneading by the above method. The thickness of the resin sheet excellent in heat dissipation in the present invention is usually 0.005 to 3 mm, preferably 0.01 to 1 mm. The resin sheet preferably has a smooth surface, and the 60 degree surface gloss value on the surface of the resin sheet measured in accordance with JIS K-7105 is preferably 10 or more.

The resin sheet of the present invention has excellent thermal conductivity, heat transfer direction selectivity, molding processability such as no tearing or uneven thickness during calendar molding, and heat dissipation components for computers such as personal computers and home game machines, Heat release parts for DVD players, DVD recorders, HDD recorders, household TVs, plasma displays, LCD TVs and other display power supply units, mobile phones, various computers, various AV equipment, OA equipment, etc. It is suitably used for applications that require high thermal conductivity, such as heat-dissipating components used, car stereos, car navigation systems, inverters, lighting, and heat-dissipating components used in automotive electrical components of air conditioners.
Hereinafter, the present invention will be described based on examples.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited only to these examples.
A hydrogenated copolymer and a modified hydrogenated copolymer were obtained by the following procedure.
In addition, the characteristics and physical properties of the polymer were measured as follows.
1. Characteristics of copolymer 1) Styrene content: measured using an ultraviolet spectrophotometer (manufactured by Shimadzu Corporation, UV-2450).
2) Polystyrene block content: The polymer before hydrogenation was used. M. Kolthoff, etal. , J .; Polym. Sc i. 1, 429 (1946).
3) Amount of vinyl bonds and hydrogenation rate: Measured using a nuclear magnetic resonance apparatus (manufactured by BRUKER, DPX-400).
4) Molecular weight and molecular weight distribution: Measured by GPC [device is manufactured by Waters], tetrahydrofuran was used as a solvent, and measurement conditions were performed at a temperature of 35 ° C. The molecular weight is a weight average molecular weight obtained by using a calibration curve (created using the peak molecular weight of standard polystyrene) obtained by measuring the molecular weight of the peak of the chromatogram from measurement of commercially available standard polystyrene. The molecular weight when there are a plurality of peaks in the chromatogram refers to the average molecular weight determined from the molecular weight of each peak and the composition ratio of each peak (determined from the area ratio of each peak in the chromatogram). The molecular weight distribution is a ratio of the obtained weight average molecular weight and number average molecular weight.
5) Crystallization peak and crystallization peak calorie: Measured by DSC [manufactured by Mac Science, DSC3200S]. The temperature was raised from room temperature to 150 ° C. at a rate of temperature rise of 30 ° C./min, and then the temperature was lowered to −100 ° C. at a rate of temperature drop of 10 ° C./min, and the crystallization curve was measured to confirm the presence or absence of a crystallization peak. Further, when there was a crystallization peak, the temperature at which the peak appeared was defined as the crystallization peak temperature, and the crystallization peak calorie was measured.
6) Modification rate: Applying the property that the modified component is adsorbed to a GPC column with a silica gel as a filler, the above-mentioned polystyrene gel (Showa Denko) Both chromatograms of GPC (manufactured by Shodex) and silica-based column GPC (Zorbax manufactured by DuPont) were measured, and the amount of adsorption to the silica column was measured from the difference between them to determine the modification rate.

<Preparation of hydrogenated copolymer>
Preparation of hydrogenated copolymer and the like Hydrogenated copolymer and the like were prepared by the following method. In the following examples, the hydrogenation catalyst used for the hydrogenation reaction was prepared by the following method.
A reaction vessel purged with nitrogen was charged with 2 liters of dried and purified cyclohexane, 40 mmol of bis (η5-cyclopentadienyl) titanium di (p-tolyl) and 1,2-polybutadiene (1,1) having a molecular weight of about 1,000. After dissolving 150 g of 2-vinyl bond (about 85%), a cyclohexane solution containing 60 mmol of n-butyllithium was dissolved and reacted at room temperature for 5 minutes. Immediately after adding 40 mmol of n-butanol, the mixture was stirred at room temperature. saved.

<Preparation of polymer 1>
The polymer 1 (hydrogenated copolymer) was prepared by copolymerization by the following method using a stirring apparatus having an internal volume of 10 L and a tank reactor with a jacket.
After charging 10 parts by weight of cyclohexane into the reactor and adjusting the temperature to 70 ° C., n-butyllithium is 0.076% by mass with respect to the weight of all monomers (total amount of butadiene monomer and styrene monomer charged into the reactor), 0.4 mol of N, N, N ′, N′-tetramethylethylenediamine (hereinafter TMEDA) is added to 1 mol of n-butyllithium, and then a cyclohexane solution containing 8 parts by mass of styrene as a monomer (monomer concentration 22 Mass%) was added over about 3 minutes, and the reaction was carried out for 30 minutes while adjusting the internal temperature of the reactor to 70 ° C.

Next, a cyclohexane solution (monomer concentration of 22% by mass) containing 48 parts by mass of butadiene and 36 parts by mass of styrene was continuously supplied to the reactor at a constant rate over 60 minutes, and then reacted for 30 minutes. During this time, the reactor internal temperature was adjusted to about 70 ° C. When the polymer solution sampled immediately after the supply was analyzed, the polymerization conversion of butadiene: 90%, the polymerization conversion of styrene: 100%, and the styrene content in the polymer was 47.8% by mass (Block B Styrene content is 42.9% by mass).
Thereafter, a cyclohexane solution containing 8 parts by mass of styrene as a monomer (monomer concentration: 22% by mass) is added over about 3 minutes, and the reaction is carried out for 30 minutes while adjusting the reactor internal temperature to about 70 ° C. Got. The resulting copolymer has a styrene content of 52% by mass, a styrene polymer block content of 16% by mass, a vinyl bond content of the butadiene part of 21% by mass, a weight average molecular weight of 16,000, and a molecular weight distribution. Was 1.2.

  Next, 100 weight ppm of the hydrogenation catalyst as titanium with respect to the weight of the copolymer was added to the obtained copolymer, and a hydrogenation reaction was performed at a hydrogen pressure of 0.7 MPa and a temperature of 65 ° C. After completion of the reaction, methanol is added, and then octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate as a stabilizer is added in an amount of 0.3% by weight based on the weight of the polymer. A hydrogenated copolymer (hereinafter referred to as polymer 1) was obtained. The hydrogenation rate of polymer 1 was 99%. As a result of dynamic viscoelasticity measurement, the peak temperature of tan δ was -15 ° C. As a result of DSC measurement, there was no crystallization peak.

<Zinc oxide>
Zinc oxide is a zinc oxide (made by Matsushita Amtech Co., Ltd., trade names: Panatetra, WZ-0501, acicular crystals) that is not surface-treated and extends from the nucleus to the four different axes from the nucleus. The diameter of the base of the part is 0.7 s to 14 μm, and the length from the base to the tip of the acicular crystal part is 3 to 200 μm.
<Acrylic resin>
As the acrylic resin, “trade name: Hybrene B403” manufactured by Zeon Corporation was used.

(Examples 1 and 2 and Comparative Example 1)
Calendar sheet molding was carried out with the composition shown in Table 1 for each component of polymer 1, zinc oxide, and acrylic resin obtained above.
Calendar molding was performed in the following steps. First, the blended composition was melt-kneaded for 5 minutes with a pressure kneader set at a volume of 75 liters, a temperature of 170 ° C., and a blade rotation speed of 20 rpm, to obtain a copolymer composition having adhesiveness. A sheet having a width of 200 mm and a thickness of 10 mm was obtained by using the composition in a bi-directional extruder with a cylinder temperature of 150 ° C. and a die attached to the tip of the extruder. The sheet was formed into a sheet with a calendar roll forming machine adjusted to have a roll diameter of 1000 mm, a width of 1600 mm, a temperature of 140 ° C., and a roll gap interval of 1.0 mm to obtain a sheet having a width of 1000 mm. The thermal conductivity of the sheet, heat transfer direction selectivity, the presence or absence of tearing during sheet molding, and the degree of thickness unevenness were confirmed. The results are shown in Table 1.
The evaluation was performed according to the following items.

<Thermal conductivity>
Using the sheet of 1.0 mm thickness obtained above, a rapid thermal conductivity measuring device QTM-500 (thin wire heating method) equipped with a thin film measurement software (SOFT-QTM5W) manufactured by Kyoto Electronics Industry Co., Ltd. was used. The thermal conductivity was measured. The measurement is a method of obtaining the thermal conductivity with a box type probe (PD-11) using a reference plate (foamed polyethylene, silicone rubber, quartz glass, mullite, zirconia) whose thermal conductivity is known (Japanese Patent Publication No. 5). No. 12361), the thermal conductivity of the resin sheet was obtained. The results are shown in Table 1.
<Judgment of heat transfer direction selectivity of calendar roll molded sheet>
Using the sheet of 1.0 mm thickness obtained above, a rapid thermal conductivity measuring device QTM-500 (thin wire heating method) equipped with a thin film measurement software (SOFT-QTM5W) manufactured by Kyoto Electronics Industry Co., Ltd. was used. The thermal conductivity was measured. The thermal conductivity was measured when a box-type probe was placed in the flow direction of the sheet and when the probe was placed perpendicular to the flow direction, and the ratio of the thermal conductivities of the two was calculated. It can be said that the larger the ratio value, the greater the heat transfer direction selectivity.
The results are shown in Table 1.

<Slight tearing of calender roll molding sheet>
The calender roll molded sheet obtained above, a width of 1000 mm and a length of 3 m were collected, and the number of locations where the sheets were not connected and the locations where holes were formed was visually confirmed. The number of the points was evaluated as 箇 所, less than 2 ◎, 2 to 5 箇 所, 5 to 10 △, 10 or more ×. The results are shown in Table 1.
<Unevenness of calendar roll molded sheet>
The calender roll molded sheet obtained above and a calender roll molded sheet having a width of 1000 mm were cut at two locations perpendicular to the sheet flow direction, and the thicknesses of the end and center of the obtained cut surface were measured. The difference obtained by subtracting the adjusted roll interval of 1.0 mm was determined from each of the thicknesses obtained by the measurement at six locations, and the average value was calculated. The results are shown in Table 1.

  The copolymer composition and the heat transfer direction selective resin sheet obtained by molding the copolymer composition in the present invention are excellent in thermal conductivity, flexibility, and calendar molding processability, and are used in computers such as personal computers and consumer game machines. Heat radiating parts, heat radiating parts for DVD players and DVD recorders, heat radiating parts for HDD recorders, heat radiating parts such as display power supply units for home TVs, plasma displays, liquid crystal TVs, mobile phones, various computers, various AV equipment It is suitably used for applications that require high thermal conductivity, such as heat dissipating parts used in office automation equipment, car stereos, car navigation systems, inverters, lighting, and heat dissipating parts used in automotive electrical components of air conditioners.

Claims (8)

Hydrogenated copolymer (1) satisfying the following (a) to (d) by adding hydrogen to a copolymer comprising a conjugated diene and a vinyl aromatic compound and / or a copolymer comprising a conjugated diene and a vinyl aromatic compound. 5 to 35% by mass of a styrenic soft resin comprising a modified hydrogenated copolymer (2) formed by adding hydrogen to a polymer and satisfying the following (a) to (d) that binds at least one functional group: Acrylic resin (based on zinc oxide (3) 65-95 mass% and components (1)-(3) 100 mass parts, which are needle-like crystals extending in different four-axis directions from the core, and the core (100). 4) A copolymer composition comprising 0.01 to 5.0 parts by mass.
(A) The content of the vinyl aromatic compound in the component (1) and / or (3) exceeds 50% by mass and is 90% by mass or less,
(B) The amount of the vinyl aromatic compound polymer block in the component (1) and / or (3) is 40% by mass or less,
(C) The weight average molecular weight of the hydrogenated copolymer of the component (1) and / or (3) is 50,000 to 1,000,000,
(D) 10% or more of the double bond based on the conjugated diene compound in the component (1) and / or (3) is hydrogenated.   The component (2) is bonded to at least one atomic group having at least one functional group selected from a hydroxyl group, an epoxy group, an amino group, a silanol group, and an alkoxysilane group. Copolymer composition.   The copolymer composition according to claim 1 or 2, wherein the amount of the vinyl aromatic compound polymer block in the component (1) and / or the component (2) is less than 10% by mass.   The copolymer composition according to claim 1 or 2, wherein the amount of the vinyl aromatic compound polymer block in the component (1) and / or the component (2) is 10 to 40% by mass. The copolymer (1) according to any one of claims 1 to 4, wherein the component (1) and / or the component (2) is a hydrogenated product of a copolymer having at least one structure selected from the following general formula: Combined composition.
(I) B
(B) B-A
(C) B-A-B
(D) (BA) _m -X
(E) (BA) _n- X-A _p
(Here, B is a random copolymer block of a conjugated diene and a vinyl aromatic compound, A is a vinyl aromatic compound polymer block, m is an integer of 2 or more, and n and p are each 1) (It is an integer above. X represents a coupling agent residue.) The copolymer composition according to any one of claims 1 to 5, wherein the component (2) is bonded to at least one atomic group having at least one functional group selected from the following. .

(In the above formula, R ^{1 to} R ⁴ are hydrogen or a hydrocarbon group having 1 to 24 carbon atoms, or a functional group selected from a hydroxyl group, an epoxy group, an amino group, a silanol group, and an alkoxysilane group. A hydrocarbon group having 24. R ⁵ is a hydrocarbon chain having 1 to 48 carbon atoms, or a hydrocarbon chain having 1 to 48 carbon atoms having a functional group selected from a hydroxyl group, an epoxy group, an amino group, a silanol group, and an alkoxysilane group. In addition, in the hydrocarbon groups of R ^{1 to} R ⁴ and the hydrocarbon chain of R ⁵ , elements such as oxygen, nitrogen, and silicon are bonded in a bonding mode other than a hydroxyl group, an epoxy group, a silanol group, and an alkoxysilane group. R ⁶ is hydrogen or an alkyl group having 1 to 8 carbon atoms.)   Component (2) is a modified copolymer obtained by adding a functional group-containing modifier to the living terminal of a copolymer comprising a conjugated diene and a vinyl aromatic compound obtained using an organolithium compound as a polymerization catalyst. The copolymer composition according to any one of claims 1 to 6, wherein the copolymer composition is hydrogenated.   The resin sheet which has the heat-transfer direction selectivity formed by shape | molding the copolymer composition of any one of Claims 1-7 in a sheet form.