JP2020132774A - Heat-conductive insulating rubber composition, heat-conductive insulating rubber molding, and production method thereof - Google Patents

Abstract

To provide: a heat-conductive insulating rubber molding excellent in the heat conductivity and the insulation even in the case of a low content of an inorganic filler; a production method thereof; and a heat-conductive insulating rubber composition for obtaining the heat-conductive insulating rubber molding.SOLUTION: The heat-conductive insulating rubber composition contains rubber, an inorganic filler, and a triazinedithiol based compound.SELECTED DRAWING: None

Description

The present invention relates to a thermally conductive insulating rubber composition, a thermally conductive insulating rubber molded body, and a method for producing the same, which are useful as materials for members required for insulation and heat dissipation such as electronic circuit boards.

With the miniaturization and high integration of electrical and electronic equipment, heat generation of mounted parts and high temperature of the usage environment have become remarkable, and there is an increasing demand for improving heat dissipation of constituent members. In particular, metals and ceramics with high thermal conductivity are currently used for heat dissipation members of automobile members and high-power LEDs, but in order to reduce weight, processability, and increase the degree of freedom in shape, high thermal conductivity is achieved. , And a thermally conductive resin material having molding processability is required. In particular, a resin made of a polymer compound is an inexpensive insulating material having excellent moldability, and is therefore used in various electronic components such as a base material for an electronic circuit board, a motor insulating material, and an insulating adhesive. In recent years, as the density and output of these electronic components have increased, the amount of heat generated from the electronic components has increased. Therefore, there is a strong demand for measures to release the heat of electronic components.

In response to this problem, in the prior art, a method of filling the inside of a resin with a filler made of an inorganic substance such as alumina or silica to increase the thermal conductivity of the resin is used. For example, Patent Documents 1 and 2 propose a technique of adding an inorganic filler such as crystalline silica and aluminum oxide to a polymer resin to impart thermal conductivity. In this case, the continuum formed by connecting the inorganic fillers functions as a heat conduction path. That is, the inorganic fillers filled in the resin need to be in contact with each other, and a large amount of inorganic fillers need to be filled for efficient heat conduction. Further, the conventional heat conductive insulating resin molded product has the following technical problems because it is necessary to add a large amount of an inorganic filler. (1) The weight is heavy. (2) Since the inorganic filler is hard, it has poor workability. (3) Voids are likely to be generated at the interface between the inorganic filler and the resin, and water stays there, resulting in low moisture resistance. (4) Since the inorganic filler is expensive, the manufacturing cost is high. (5) A resin molded product having a large amount of the inorganic filler filled requires a certain thickness in order to maintain its shape, and it is difficult to reduce the thickness. In order to solve these problems, in Patent Document 3, in Patent Document 3, a core / shell particle comprising a core particle containing a polymer compound and a shell containing a thermally conductive and insulating inorganic compound that coats the core particle. A thermally conductive insulating resin molded body formed by an aggregate has been proposed.

Japanese Unexamined Patent Publication No. 11-23649 Japanese Patent No. 3559137 Japanese Patent No. 5278488

However, the thermally conductive insulating resin molded product described in Patent Document 3 has a problem of low thermal conductivity because the core particles containing the polymer compound are coated with the shell containing the inorganic compound. Further, in the conventional heat conductive insulating resin molded body, the inorganic filler filled in the resin tends to aggregate, and it is difficult to form a continuous body formed by connecting the inorganic fillers, so that sufficient thermal conductivity can be obtained. There was a problem that there was no.

According to the present invention, a thermally conductive insulating rubber molded body having excellent thermal conductivity and insulating properties even when the content of the inorganic filler is small, a method for producing the same, and a thermally conductive insulation for obtaining the thermally conductive insulating rubber molded body. It is an object of the present invention to provide a rubber composition.

As a result of diligent studies to solve the above problems, the present inventors have found that the above object can be achieved by adding a triazinedithiol-based compound together with an inorganic filler to the thermally conductive insulating rubber composition. The present invention has been completed.

（式中、Ｍ^１及びＭ^２はそれぞれ独立にＨ、Ｌｉ、Ｎａ、Ｋ、又はＣｓであり、Ｒ^１はＳ、Ｏ、又はＮＲ^３であり、Ｒ^３はＨ、又はアルキル基、ハロゲン化アルキル基、ヒドロキシアルキル基、アルコキシアルキル基、アルケニル基、ハロゲン化アルケニル基、ヒドロキシアルケニル基、アルコキシアルケニル基、フェニル基、ハロゲン化フェニル基、ヒドロキシフェニル基、アルコキシフェニル基、ビフェニル基、ハロゲン化ビフェニル基、ヒドロキシビフェニル基、アルコキシビフェニル基、ナフチル基、ハロゲン化ナフチル基、ヒドロキシナフチル基、アルコキシナフチル基、カルボキシル基、エステル基、ウレタン基、アゾ基、シアノ基、アミノ基、アミド基、及びアルコキシシリル基からなる群より選択される少なくとも１種の官能基を有する有機基であり、Ｒ^２は前記有機基と同じであり、あるいはＮＲ^３とＲ^２はヘテロ環を構成する。）
［２］
前記トリアジンジチオール系化合物は、下記一般式（２）〜（４）で表されるトリアジンジチオール系化合物の少なくとも１種である［１］に記載の熱伝導性絶縁ゴム組成物。

（式中、Ｍ^１、Ｍ^２、Ｒ^２、及びＲ^３は前記と同じである。）

（式中、Ｍ^１及びＭ^２は前記と同じであり、Ｒ^１はＳ、Ｏ、−ＮＨＣＨ_２ＣＨ_２Ｏ−、−Ｎ（ＣＨ_３）ＣＨ_２ＣＨ_２Ｏ−、−Ｎ（Ｃ_３Ｈ_７）ＣＨ_２ＣＨ_２Ｏ−、−ＮＨＣＨ_２ＣＨ_２ＣＨ_２ＣＨ_２Ｏ−、−Ｎ（Ｃ_２Ｈ_５）ＣＨ_２ＣＨ_２ＣＨ_２ＣＨ_２Ｏ−、−ＮＨＣＨ_２（ＣＨ_２）_８ＣＨ_２Ｏ−、−ＮＨＣＨ_２ＣＨ（ＣＨ_３）Ｏ−、−ＮＨＣ_６Ｈ_４Ｏ−、−Ｎ（Ｃ_２Ｈ_５）Ｃ_６Ｈ_４Ｏ−、−ＮＨＣ_１０Ｈ_６Ｏ−、−Ｎ（ＣＨ_２ＣＨ_２）_２ＣＨＯ−、−Ｎ（ＣＨ_２ＣＨ_２）_２ＮＣＨ_２ＣＨ_２Ｏ−、−Ｎ（ＣＨ_２ＣＨ_２ＯＨ）ＣＨ_２ＣＨ_２Ｏ−、−Ｎ（ＣＨ_２ＣＨ_２ＣＨ_２ＯＨ）ＣＨ_２ＣＨ_２ＣＨ_２Ｏ−、−Ｎ（ＣＨ_２ＣＨ（ＣＨ_３）ＯＨ）ＣＨ_２ＣＨ（ＣＨ_３）Ｏ−、−Ｎ（ＣＨ_２ＣＨ_２ＣＨ_２ＣＨ_２ＯＨ）ＣＨ_２ＣＨ_２ＣＨ_２ＣＨ_２Ｏ−、−ＮＨＣＨ_２Ｃ_６Ｈ_４Ｏ−、−ＮＨＣ_６Ｈ_１１Ｏ−、又は−Ｎ（Ｃ_３Ｈ_７）Ｃ_６Ｈ_４Ｏ−であり、Ｒ^４はアルキレン基であり、Ｒ^５はアルコキシ基であり、Ｒ^６及びＲ^７はそれぞれ独立にアルコキシ基又はアルキル基である。）

（式中、Ｍ^１、Ｍ^２、及びＲ^５〜Ｒ^７は前記と同じであり、Ｒ^８は水素又はアルキル基であり、Ｒ^９はアルキレン基又はアルキレンオキシ基であり、Ｒ^８とＲ^９は互いに結合して環を形成してもよい。）
［３］
前記無機フィラーは、窒化アルミニウムフィラー及び窒化ホウ素フィラーからなる群より選択される少なくとも１種を含む［１］又は［２］に記載の熱伝導性絶縁ゴム組成物。
［４］
前記無機フィラーの含有量は、前記ゴム１００質量部に対して２０〜４００質量部である［１］〜［３］のいずれかに記載の熱伝導性絶縁ゴム組成物。
［５］
前記トリアジンジチオール系化合物の含有量は、前記無機フィラー１００質量部に対して５×１０^−７〜５質量部である［１］〜［４］のいずれかに記載の熱伝導性絶縁ゴム組成物。
［６］
前記ゴムは、天然ゴム、イソプレンゴム、ブタジエンゴム、及びエチレン−プロピレン−ジエンゴムから選択される少なくとも２種のゴムを含む［１］〜［５］のいずれかに記載の熱伝導性絶縁ゴム組成物。
［７］
［１］〜［６］のいずれかに記載の熱伝導性絶縁ゴム組成物から得られる熱伝導性絶縁ゴム成形体。
［８］
前記熱伝導性絶縁ゴム成形体は、熱伝導性絶縁ゴムシートである［７］に記載の熱伝導性絶縁ゴム成形体。
［９］
［７］又は［８］に記載の熱伝導性絶縁ゴム成形体の製造方法であって、前記無機フィラーと前記トリアジンジチオール系化合物とを接触させて、前記無機フィラーの表面に前記トリアジンジチオール系化合物を付着させて表面修飾無機フィラーを得る工程Ａ、前記表面修飾無機フィラーを前記ゴム中に分散させて前記熱伝導性絶縁ゴム組成物を得る工程Ｂ、及び前記熱伝導性絶縁ゴム組成物を成形する工程Ｃを含む熱伝導性絶縁ゴム成形体の製造方法。
［１０］
前記工程Ｃにおいて、前記熱伝導性絶縁ゴム組成物を加圧及び／又は加熱して成形する［９］に記載の熱伝導性絶縁ゴム成形体の製造方法。 That is, the present invention has the following configuration.
[1]
A thermally conductive insulating rubber composition containing a rubber, an inorganic filler, and a triazinedithiol-based compound represented by the following general formula (1).

(In the formula, M ¹ and M ² are independently H, Li, Na, K, or Cs, R ¹ is S, O, or NR ³ , and R ³ is H, or an alkyl group, halogenated. Alkyl group, hydroxyalkyl group, alkoxyalkyl group, alkenyl group, halogenated alkenyl group, hydroxyalkenyl group, alkoxyalkenyl group, phenyl group, halogenated phenyl group, hydroxyphenyl group, alkoxyphenyl group, biphenyl group, halogenated biphenyl group , Hydroxybiphenyl group, alkoxybiphenyl group, naphthyl group, naphthyl halide group, hydroxynaphthyl group, alkoxynaphthyl group, carboxyl group, ester group, urethane group, azo group, cyano group, amino group, amide group, and alkoxysilyl group. It is an organic group having at least one functional group selected from the group consisting of, R ² is the same as the organic group, or NR ³ and R ² form a heterocycle).
[2]
The thermally conductive insulating rubber composition according to [1], wherein the triazinedithiol-based compound is at least one of the triazinedithiol-based compounds represented by the following general formulas (2) to (4).

(In the formula, M ¹ , M ² , R ² and R ³ are the same as above.)

(In the equation, M ¹ and M ² are the same as above, and R ¹ is S, O, -NHCH ₂ CH ₂ O-, -N (CH ₃ ) CH ₂ CH ₂ O-, -N (C ₃ H). ₇ ) CH ₂ CH ₂ O-, -NHCH ₂ CH ₂ CH ₂ CH ₂ O-, -N (C ₂ H ₅ ) CH ₂ CH ₂ CH ₂ CH ₂ O-, -NHCH ₂ (CH ₂ ) ₈ CH ₂ O-, -NHCH ₂ CH (CH ₃ ) O-, -NHC ₆ H ₄ O-, -N (C ₂ H ₅ ) C ₆ H ₄ O-, -NHC ₁₀ H ₆ O-, -N (CH ₂₎ CH ₂ ) ₂ CHO-, -N (CH ₂ CH ₂ ) ₂ NCH ₂ CH ₂ O-, -N (CH ₂ CH ₂ OH) CH ₂ CH ₂ O-, -N (CH ₂ CH ₂ CH ₂ OH) CH ₂ CH ₂ CH ₂ O-, -N (CH ₂ CH (CH ₃ ) OH) CH ₂ CH (CH ₃ ) O-, -N (CH ₂ CH ₂ CH ₂ CH ₂ OH) CH ₂ CH ₂ CH ₂ CH ₂ O-, -NHCH ₂ C ₆ H ₄ O-, -NHC ₆ H ₁₁ O-, or -N (C ₃ H ₇ ) C ₆ H ₄ O-, where R ⁴ is an alkylene group and R ⁵ is an alkoxy group, and R ⁶ and R ⁷ are independently alkoxy groups or alkyl groups.)

(In the formula, M ¹ , M ² and R ^{5 to} R ⁷ are the same as above, R ⁸ is a hydrogen or alkyl group, R ⁹ is an alkylene group or an alkyleneoxy group, and R ⁸ and R ⁹ May combine with each other to form a ring.)
[3]
The thermally conductive insulating rubber composition according to [1] or [2], wherein the inorganic filler contains at least one selected from the group consisting of an aluminum nitride filler and a boron nitride filler.
[4]
The thermally conductive insulating rubber composition according to any one of [1] to [3], wherein the content of the inorganic filler is 20 to 400 parts by mass with respect to 100 parts by mass of the rubber.
[5]
The thermally conductive insulating rubber composition according to any one of [1] to [4], wherein the content of the triazine dithiol compound is 5 × ^10-7 to 5 parts by mass with respect to 100 parts by mass of the inorganic filler. ..
[6]
The thermally conductive insulating rubber composition according to any one of [1] to [5], wherein the rubber contains at least two kinds of rubbers selected from natural rubber, isoprene rubber, butadiene rubber, and ethylene-propylene-diene rubber. ..
[7]
A thermally conductive insulating rubber molded body obtained from the thermally conductive insulating rubber composition according to any one of [1] to [6].
[8]
The thermally conductive insulating rubber molded body according to [7], which is a thermally conductive insulating rubber sheet.
[9]
The method for producing a thermally conductive insulating rubber molded product according to [7] or [8], wherein the inorganic filler is brought into contact with the triazinedithiol-based compound, and the triazinedithiol-based compound is brought onto the surface of the inorganic filler. Step A to obtain the surface-modified inorganic filler, the step B to disperse the surface-modified inorganic filler in the rubber to obtain the thermally conductive insulating rubber composition, and molding the thermally conductive insulating rubber composition. A method for producing a thermally conductive insulating rubber molded product, which comprises step C.
[10]
The method for producing a thermally conductive insulating rubber molded product according to [9], wherein the thermally conductive insulating rubber composition is formed by pressurizing and / or heating in the step C.

The thermally conductive insulating rubber composition of the present invention contains a triazinedithiol-based compound together with an inorganic filler. By adhering the triazinedithiol-based compound to the surface of the inorganic filler, an inorganic filler surface-modified with the triazinedithiol-based compound (surface-modified inorganic filler) can be obtained. Since the surface-modified inorganic filler has higher dispersibility than the conventional inorganic filler, it is less likely to aggregate in rubber. Therefore, a continuous body formed by connecting surface-modified inorganic fillers is likely to be formed in the rubber. As a result, the thermally conductive insulating rubber molded body obtained from the thermally conductive insulating rubber composition of the present invention has excellent thermal conductivity even when the content of the inorganic filler is small.

Hereinafter, embodiments of the present invention will be described.

（式中、Ｍ^１及びＭ^２はそれぞれ独立にＨ、Ｌｉ、Ｎａ、Ｋ、又はＣｓであり、Ｒ^１はＳ、Ｏ、又はＮＲ^３であり、Ｒ^３はＨ、又はアルキル基、ハロゲン化アルキル基、ヒドロキシアルキル基、アルコキシアルキル基、アルケニル基、ハロゲン化アルケニル基、ヒドロキシアルケニル基、アルコキシアルケニル基、フェニル基、ハロゲン化フェニル基、ヒドロキシフェニル基、アルコキシフェニル基、ビフェニル基、ハロゲン化ビフェニル基、ヒドロキシビフェニル基、アルコキシビフェニル基、ナフチル基、ハロゲン化ナフチル基、ヒドロキシナフチル基、アルコキシナフチル基、カルボキシル基、エステル基、ウレタン基、アゾ基、シアノ基、アミノ基、アミド基、及びアルコキシシリル基からなる群より選択される少なくとも１種の官能基を有する有機基であり、Ｒ^２は前記有機基と同じであり、あるいはＮＲ^３とＲ^２はヘテロ環を構成する。） The thermally conductive insulating rubber composition of the present invention contains a rubber, an inorganic filler, and a triazinedithiol-based compound represented by the following general formula (1). An elastomer, a thermoplastic resin, and a thermosetting resin may be appropriately blended in the composition as long as the effects of the present invention are not impaired. These may be blended alone or in combination of two or more.

(In the formula, M ¹ and M ² are independently H, Li, Na, K, or Cs, R ¹ is S, O, or NR ³ , and R ³ is H, or an alkyl group, halogenated. Alkyl group, hydroxyalkyl group, alkoxyalkyl group, alkenyl group, halogenated alkenyl group, hydroxyalkenyl group, alkoxyalkenyl group, phenyl group, halogenated phenyl group, hydroxyphenyl group, alkoxyphenyl group, biphenyl group, halogenated biphenyl group , Hydroxybiphenyl group, alkoxybiphenyl group, naphthyl group, naphthyl halide group, hydroxynaphthyl group, alkoxynaphthyl group, carboxyl group, ester group, urethane group, azo group, cyano group, amino group, amide group, and alkoxysilyl group. It is an organic group having at least one functional group selected from the group consisting of, R ² is the same as the organic group, or NR ³ and R ² form a heterocycle).

<Rubber>
Known rubber can be used without particular limitation, and is appropriately selected depending on the application of the heat conductive insulating rubber molded product and the like.

The rubber may be a natural product or a synthetic rubber, and for example, natural rubber (NR), isoprene rubber (IR), styrene rubber (SR), butadiene rubber (BR), styrene-butadiene rubber (SBR), ethylene-propylene. Examples thereof include rubber (EPR), ethylene-propylene-diene rubber (EPDM), butyl rubber (IIR), butyl halide rubber, chloroprene rubber, nitrile rubber, acrylic rubber, urethane rubber, and fluororubber. These may be used alone or in combination of two or more. In the present invention, from the viewpoint of achieving both energy saving and durability, it is preferable to use two or more kinds of rubber in combination, and at least two kinds selected from natural rubber, isoprene rubber, butadiene rubber, and ethylene-propylene-diene rubber. It is more preferable to use the above rubber in combination, and it is further preferable to use natural rubber or isoprene rubber in combination with butadiene rubber or ethylene-propylene-diene rubber.

From the viewpoint of achieving both energy saving and durability, the rubber is preferably composed of 15 to 85% by mass of natural rubber or isoprene rubber, and 85 to 15% by mass of butadiene rubber or ethylene-propylene-diene rubber, and is preferably natural rubber or isoprene rubber. It is more preferably composed of 20 to 60% by mass of isoprene rubber and 80 to 40% by mass of butadiene rubber or ethylene-propylene-diene rubber, 25 to 55% by mass of natural rubber or isoprene rubber, and 75 by butadiene rubber or ethylene-propylene-diene rubber 75. It is more preferably composed of ~ 45% by mass, particularly preferably 30 to 45% by mass of natural rubber or isoprene rubber, and 70 to 55% by mass of butadiene rubber or ethylene-propylene-diene rubber. When the natural rubber or isoprene rubber is 15% by mass or more, the natural rubber or isoprene rubber becomes a sea with a sea-island structure of the rubber component, so that the fracture resistance is improved. On the other hand, when the butadiene rubber or the ethylene-propylene-diene rubber is at least 15% by mass, the energy saving property is improved.

As the butadiene rubber, high cis butadiene rubber is preferable from the viewpoint of achieving both energy saving and durability. The high cis butadiene rubber is a butadiene rubber having a cis-1,4 bond content of 90% or more and less than 98% in 1,3-butadiene units as measured by FT-IR. The cis-1,4 bond content in the 1,3-butadiene unit of the high cis butadiene rubber is preferably 95% or more and less than 98%. The method for producing the high cis butadiene rubber is not particularly limited, and it can be produced by a known method. For example, it can be produced by polymerizing butadiene using a neodymium-based catalyst. Further, high-cis butadiene rubber is commercially available, and examples thereof include "BR01" and "T700" manufactured by JSR Corporation.

Further, examples of the olefin-based rubber include ethylene-α-olefin-diolefin copolymer rubber (hereinafter, may be referred to as “copolymerized rubber”). The α-olefin used as the copolymerization monomer is preferably an α-olefin having 3 to 12 carbon atoms. Examples of the α-olefin having 3 to 12 carbon atoms include propylene, butene-1, 4-methylpentene-1, hexene-1, octene-1, and the like, and propylene is preferable. These α-olefins may be used alone or in combination of two or more. Further, as the diolefin, at least one non-conjugated diolefin is copolymerized. Examples of the non-conjugated diolefin include dicyclopentadiene, tricyclopentadiene, 5-methyl-2,5-norbornene, 5-methylene-2-norbornene, 5-ethylidene-2-norbornene, and 5-isopropylidene-2-. Norbornene, 5-isopropenyl-2-norbornene, 5- (1-butenyl) -2-norbornene, cyclooctadiene, vinylcyclohexene, 1,5,9-cyclododecatriene, 6-methyl-4,7,8, 9-Tetrahydroindene, 2,2'-dicyclopentenyl, trans-1,2-divinylcyclobutane, 1,4-hexadiene, 2-methyl-1,4-hexadiene, 1,6-octadene, 1,7-octadien , 1,8-Norbornene, 1,9-Decadien, 3,6-dimethyl-1,7-octadene, 4,5-dimethyl-1,7-octadene, 1,4,7-octatriene, and 5-methyl -1,8-Norbornene and the like can be mentioned. Among these non-conjugated diolefins, 5-ethylidene-2-norbornene (ENB) and / or dicyclopentadiene (DCP) are particularly preferable. These rubbers are preferable because the heat resistance is improved by cross-linking or vulcanizing by a known method. In the present invention, the amylphenol disulfide polymer which is a co-crosslinking agent may be used in combination with other cross-linking agents such as zinc acrylate and zinc methacrylate. In this case, another cross-linking agent can be used in a blending amount within a range in which the desired effect of the present invention is not impaired.

The rubber-containing rubber kneaded product (master batch) contains, if necessary, a vulcanizing agent, a vulcanization accelerator, and an antiaging agent, which are usually used in the rubber industry, as long as the effects of the present invention are not impaired. , Carbon, silica, zinc oxide (ZnO), waxes, antioxidants, fillers, foaming agents, plasticizers, oils, lubricants, tackifiers, petroleum resins, ultraviolet absorbers, dispersants, compatibilizers, And additives such as a homogenizing agent can be blended.

As the oil, known oils can be used without particular limitation. Specifically, process oils such as aromatic oils, naphthenic oils and paraffin oils; vegetable oils such as coconut oils; synthesis of alkylbenzene oils and the like. Oil: Castor oil and the like. These may be used alone or in combination of two or more. Of these, it is preferable to use paraffin oil. The blending amount of the oil is not particularly limited, but is preferably 80 parts by mass or less with respect to 100 parts by mass of the rubber. If the blending amount of the oil deviates from the above range, the kneading workability may be deteriorated. When oil-expanded rubber is used, the total amount of the oil contained in the rubber and the oil separately added at the time of mixing is adjusted to be within the above range.

In the present invention, from the viewpoint of promoting vulcanization, it is preferable to add a vulcanization promoting aid such as zinc oxide (ZnO) and fatty acid. The fatty acid may be a saturated, unsaturated, linear or branched fatty acid. The carbon number of the fatty acid is also not particularly limited, and for example, the carbon number is 1 to 30, preferably 15 to 30. Examples of fatty acids include cyclohexanoic acid (cyclohexanecarboxylic acid) and naphthenic acid such as alkylcyclopentane having a side chain; hexanoic acid, octanoic acid, decanoic acid (including branched carboxylic acid such as neodecanoic acid), dodecanoic acid. Saturated fatty acids such as tetradecanoic acid, hexadecanoic acid, and octadecanoic acid (stearic acid); unsaturated fatty acids such as methacrylic acid, oleic acid, linoleic acid, and linolenic acid; resin acids such as rosin, tall oil acid, and avietic acid. And so on. These may be used alone or in combination of two or more. Of these, zinc oxide and / or stearic acid is preferably used. The blending amount of the vulcanization accelerating aid is preferably 1 to 10 parts by mass, and more preferably 2 to 7 parts by mass with respect to 100 parts by mass of the rubber. If the blending amount of the vulcanization accelerating aid exceeds 10 parts by mass, workability may be deteriorated and the dynamic ratio may be deteriorated, and if it is less than 1 part by mass, vulcanization may be delayed.

As the anti-aging agent, known ones can be used without particular limitation, and examples thereof include amine-based anti-aging agents, phenol-based anti-aging agents, and imidazole-based anti-aging agents. Specifically, p, p'-dioctyldiphenylamine, p, p'-dimyldiphenylamine, N, N'-diphenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, N- Phenyl-N'-1,3-dimethylbutyl-p-phenylenediamine, 2,2,4-trimethyl-1,2-dihydroquinolin polymer, and 6-ethoxy-2,2,4-trimethyl-1,2- Amine-based anti-aging agents such as dihydroquinolin; 2,6-di-t-butyl-4-methylphenol, 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionic acid stearate, 2, 2'-Methylenebis (4-methyl-6-t-butylphenol), tetrakis (methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) flopionate) methane, 4,4'-thiobis (3) -Methyl-6-t-Phenylphenol), and phenolic anti-aging agents such as 2,5-di-t-butylhydroquinone; 2-mercaptobenzimidazole, tributylthiourea, 2-mercaptobenzimidazole zinc salt, and 2-mercapto Examples thereof include imidazole-based antiaging agents such as methylbenzimidazole zinc salt. The amount of the antiaging agent to be blended is usually 1 to 10 parts by mass, preferably 2 to 7 parts by mass with respect to 100 parts by mass of the rubber.

The method for producing a rubber kneaded product (masterbatch) is not particularly limited, and all the raw materials may be mixed and kneaded at once, or each raw material may be mixed and kneaded in two or three stages. May be good. A kneading machine such as a roll, an internal mixer, and a Banbury rotor can be used for kneading.

<Inorganic filler>
As the inorganic filler, known ones can be used without particular limitation. Examples of the inorganic filler include aluminum, copper, nickel; alumina, magnesium oxide, beryllium oxide, chromium oxide, titanium oxide; boron nitride, aluminum nitride, silicon nitride, titanium nitride, tantalum nitride, chromium nitride; titanium booxide, hoe. Zirconium alloy, Hafnium booxide, Ittrium booxide, Vanadium borate, Magnesium diboride, Niobbo, Tantalum borate, Tallium borate; boron carbide, titanium carbide, zirconium carbide, vanadium carbide, niobium carbide, tantalum carbide, Chromium carbide, molybdenum carbide, tungsten carbide, tungsten carbide II tungsten carbide; Fe-Si alloy, Fe-Al alloy, Fe-Si-Al alloy, Fe-Si-Cr alloy, Fe-Ni alloy, Fe-Ni-Co alloy , Fe-Ni-Mo alloy, Fe-Co alloy, Fe-Si-Al-Cr alloy, Fe-Si-B alloy, Fe-Si-Co-B alloy; Mn-Zn ferrite, Mn-Mg-Zn ferrite, Examples thereof include Mg-Cu-Zn ferrite, Ni-Zn ferrite, Ni-Cu-Zn ferrite, and Cu-Zn ferrite. These may be used alone or in combination of two or more.

Of these, from the viewpoint of thermal conductivity and electrical insulation, preferred are alumina, magnesium oxide, magnesium oxide, beryllium oxide, chromium oxide, titanium oxide, boron nitride, aluminum nitride, silicon nitride, titanium nitride, chromium nitride, and the like. Selected from the group consisting of tantalum boride, titanium boride, zirconium boride, hafnium boride, ittrium boride, vanadium boride, magnesium diboride, niobium boride, tantalum boride, tarium boride, and molybdenum boride. At least one of these, more preferably alumina, magnesium oxide, magnesium oxide, beryllium oxide, chromium oxide, titanium oxide, boron nitride, aluminum nitride, silicon nitride, titanium nitride, chromium nitride, titanium boride, zirconium boride. , Hafnium boride, yttrium boride, vanadium borate, magnesium diboronide, niobium boride, tantalum boride, tarium boride, and molybdenum boride, at least one selected from the group, more preferably. , At least one selected from the group consisting of aluminum nitride and boron nitride.

The inorganic filler is preferably particles having no extreme difference in length, width, and thickness, and preferably has an aspect ratio of 0.8 to 1.0. The shape of the inorganic filler may be not only spherical but also polyhedral such as needle-shaped, lump-shaped, cubic or dodecahedron.

The particle size of the inorganic filler is not particularly limited, but is preferably 0.1 to 500 μm, more preferably 0.5 to 300 μm, still more preferably 1 to 200 μm or more, and when the particle size exceeds 500 μm, thermal conductivity. It is not preferable from the viewpoint of surface appearance, and if the particle size is less than 0.1 μm, the dispersibility is lowered and the cost is increased, which tends to be unfavorable.

The content of the inorganic filler in the thermally conductive insulating rubber composition is not particularly limited, but from the viewpoint of obtaining excellent thermal conductivity, it is preferably 20 to 400 parts by mass with respect to 100 parts by mass of the rubber. It is preferably 25 to 350 parts by mass, more preferably 30 to 300 parts by mass, even more preferably 50 to 200 parts by mass, and if it is less than 20 parts by mass, the thermal conductivity tends to decrease, and 400 If it exceeds the mass part, the flexibility tends to decrease.

（式中、Ｍ^１及びＭ^２はそれぞれ独立にＨ、Ｌｉ、Ｎａ、Ｋ、又はＣｓであり、Ｒ^１はＳ、Ｏ、又はＮＲ^３であり、Ｒ^３はＨ、又はアルキル基、ハロゲン化アルキル基、ヒドロキシアルキル基、アルコキシアルキル基、アルケニル基、ハロゲン化アルケニル基、ヒドロキシアルケニル基、アルコキシアルケニル基、フェニル基、ハロゲン化フェニル基、ヒドロキシフェニル基、アルコキシフェニル基、ビフェニル基、ハロゲン化ビフェニル基、ヒドロキシビフェニル基、アルコキシビフェニル基、ナフチル基、ハロゲン化ナフチル基、ヒドロキシナフチル基、アルコキシナフチル基、カルボキシル基、エステル基、ウレタン基、アゾ基、シアノ基、アミノ基、アミド基、及びアルコキシシリル基からなる群より選択される少なくとも１種の官能基を有する有機基であり、Ｒ^２は前記有機基と同じであり、あるいはＮＲ^３とＲ^２はヘテロ環を構成する。） <Triazinedithiol compounds>
The triazinedithiol-based compound used in the present invention is represented by the following general formula (1). The triazinedithiol-based compound may be used alone or in combination of two or more.

(In the formula, M ¹ and M ² are independently H, Li, Na, K, or Cs, R ¹ is S, O, or NR ³ , and R ³ is H, or an alkyl group, halogenated. Alkyl group, hydroxyalkyl group, alkoxyalkyl group, alkenyl group, halogenated alkenyl group, hydroxyalkenyl group, alkoxyalkenyl group, phenyl group, halogenated phenyl group, hydroxyphenyl group, alkoxyphenyl group, biphenyl group, halogenated biphenyl group , Hydroxybiphenyl group, alkoxybiphenyl group, naphthyl group, naphthyl halide group, hydroxynaphthyl group, alkoxynaphthyl group, carboxyl group, ester group, urethane group, azo group, cyano group, amino group, amide group, and alkoxysilyl group. It is an organic group having at least one functional group selected from the group consisting of, R ² is the same as the organic group, or NR ³ and R ² form a heterocycle).

The alkyl group may be linear, branched, or cyclic. The number of carbon atoms of the alkyl group is not particularly limited, but is preferably 1 to 40, and more preferably 1 to 30.

The alkenyl group may be linear, branched, or cyclic. The number of carbon atoms of the alkenyl group is not particularly limited, but is preferably 1 to 40, and more preferably 1 to 30.

The halogen is not particularly limited, and examples thereof include fluorine, chlorine, bromine, and iodine.

The number of carbon atoms of the alkoxy group is not particularly limited, but is preferably 1 to 40, and more preferably 1 to 30.

（式中、Ｍ^１、Ｍ^２、Ｒ^２、及びＲ^３は前記と同じである。） The triazinedithiol-based compound is preferably at least one of the triazinedithiol-based compounds represented by the following general formulas (2) to (4).

(In the formula, M ¹ , M ² , R ² and R ³ are the same as above.)

In the general formula (2), R ³ is preferably -H, -CH ₃ , -C ₂ H ₅ , -C ₃ H ₇ , -CH ₂ CH ₂ CN, or -CH ₂ CH = CH ₂ . Yes, R ² is preferably -C ₈ H ₁₆ CH = CHC ₈ H ₁₇ , -C ₈ H ₁₆ CH = CH ₂ , -C ₆ H ₄ CH = CHC ₆ H ₅ , -C ₆ H ₄ CH = CHC ₆ H ₄ OCH ₃ , -C ₆ H ₄ CH = CH ₂ , -CH ₂ C ₆ H ₄ CH = CH ₂ , -CH ₂ CH = CH ₂ , -CH ₂ NHCOC (CH ₃ ) = CH ₂ ,- C ₆ H ₄ NHC ₆ H ₅ , -C ₆ H ₄ N = NC ₆ H ₅ , -C ₆ H ₂ [C (CH ₃ ) ₃ ] ₂ OH, -C ₆ H ₄ C ₆ H ₅ , -C ₆ H ₄ C ₆ H ₄ C ₆ H ₅ , -CH ₂ COOH, -CH ₂ COOC ₂ H ₅ , -CH ₂ COOC ₈ H ₁₇ , -CH ₂ CH (C ₆ H ₅ ) ₂ , -CH ₂ CH ₂ OH , -CH ₂ CH ₂ CH ₂ CH ₂ OH, -CH ₂ (CH ₂ ) ₈ CH ₂ OH, -CH ₂ CH (CH ₃ ) OH, -C ₆ H ₄ OH, -C ₁₀ H ₆ OH, -CH ₂ C ₄ F ₉ , -CH ₂ C ₆ F ₁₃ , -CH ₂ C ₇ F ₁₅ , -CH ₂ C ₈ F ₁₇ , -CH ₂ CH ₂ C ₄ F ₉ , -CH ₂ CH ₂ C ₆ F ₁₃ , -CH ₂ CH ₂ C ₈ F ₁₇ , -CH ₂ CH ₂ C ₁₀ F ₂₁ , -CH ₂ CH ₂ CH ₂ C ₈ F ₁₇ , -C ₆ H ₄ C ₈ F ₁₇ , -C ₆ H ₄ C ₄ F ₉ , -C ₆ F ₅ , -C ₃ H ₆ Si (OCH ₃ ) ₃ , -C ₄ H ₈ Si (OCH ₃ ) ₃ , -C ₆ H ₁₂ Si (OCH ₃ ) ₃ , -C ₁₀ H ₂₀ Si (OCH ₃ ) ₃ , -CH ₂ CH ₂ NHC ₃ H ₆ Si (OCH ₃ ) ₃ , -C ₃ H ₆ Si (OC ₂ H ₅ ) ₃ , -C ₃ H ₆ Si (OCH ₃ ) ₂ CH ₃ , -C ₃ H ₆ Si (CH ₃ ) ₂ OCH ₃ or -C ₃ H ₆ Si (CH ₃ ) ₂ OSI (CH ₃ ) ₃ .

Alternatively, in the general formula (2), R ³ and R ² are the same, preferably -CH ₂ CH = CH ₂ , -C ₈ H ₁₆ CH = CHC ₈ H ₁₇ , -C ₈ H ₁₆ CH. = CH ₂ , -C ₆ H ₄ CH = CHC ₆ H ₅ , -C ₆ H ₄ CH = CHC ₆ H ₄ OCH ₃ , -C ₆ H ₄ CH = CH ₂ , -CH ₂ C ₆ H ₄ CH = CH ₂ , -CH ₂ CH = CH ₂ , -CH ₂ NHCOC (CH ₃ ) = CH ₂ , -C ₆ H ₄ NHC ₆ H ₅ , -C ₆ H ₄ N = NC ₆ H ₅ , -C ₆ H ₂ [ C (CH ₃ ) ₃ ] ₂ OH, -C ₆ H ₄ C ₆ H ₅ , -C ₆ H ₄ C ₆ H ₄ C ₆ H ₅ , -CH ₂ COOH, -CH ₂ COOC ₂ H ₅ , -CH ₂ COOC ₈ H ₁₇ , -CH ₂ CH (C ₆ H ₅ ) ₂ , -CH ₂ CH ₂ OH, -CH ₂ CH ₂ CH ₂ CH ₂ OH, -CH ₂ (CH ₂ ) ₈ CH ₂ OH, -CH ₂ CH (CH ₃ ) OH, -C ₆ H ₄ OH, -C ₁₀ H ₆ OH, -CH ₂ C ₄ F ₉ , -CH ₂ C ₆ F ₁₃ , -CH ₂ C ₈ F ₁₇ , -CH ₂ CH ₂ C ₄ F ₉ , -CH ₂ CH ₂ C ₆ F ₁₃ , -CH ₂ CH ₂ C ₈ F ₁₇ , -CH ₂ CH ₂ C ₁₀ F ₂₁ , -CH ₂ CH ₂ CH ₂ C ₈ F ₁₇ , -C ₆ H ₄ C ₈ F ₁₇ , -C ₆ H ₄ C ₄ F ₉ , -C ₆ F ₅ , -C ₃ H ₆ Si (OCH ₃ ) ₃ , -C ₄ H ₈ Si (OCH ₃ ) ₃ , -C ₆ H ₁₂ Si (OCH ₃ ) ₃ , -C ₁₀ H ₂₀ Si (OCH ₃ ) ₃ , -CH ₂ CH ₂ NHC ₃ H ₆ Si (OCH ₃ ) ₃ , -C ₃ H ₆ Si (OC ₂ H ₅ ) ₃ , -C ₃ H ₆ Si (OCH ₃ ) ₂ CH ₃ , -C ₃ H ₆ Si (CH ₃ ) ₂ OCH ₃ , or -C ₃ H ₆ Si (CH ₃ ) ₂ OSi (CH ₃ ) ₃ .

Alternatively, in the general formula (2), N, R ³ and R ² form a heterocycle, and R ³ and R ² are preferably − (CH ₂ CH ₂ ) ₂ CHOH, − (CH ₂ CH _2). ) ₂ CHOCOC ₈ H ₁₇ CH = CH ₂ ,-(CH ₂ CH ₂ ) ₂ CHOCH ₃ , or-(CH ₂ CH ₂ ) ₂ CHOCOC (CH ₃ ) = CH ₂ .

（式中、Ｍ^１及びＭ^２は前記と同じであり、Ｒ^１はＳ、Ｏ、−ＮＨＣＨ_２ＣＨ_２Ｏ−、−Ｎ（ＣＨ_３）ＣＨ_２ＣＨ_２Ｏ−、−Ｎ（Ｃ_３Ｈ_７）ＣＨ_２ＣＨ_２Ｏ−、−ＮＨＣＨ_２ＣＨ_２ＣＨ_２ＣＨ_２Ｏ−、−Ｎ（Ｃ_２Ｈ_５）ＣＨ_２ＣＨ_２ＣＨ_２ＣＨ_２Ｏ−、−ＮＨＣＨ_２（ＣＨ_２）_８ＣＨ_２Ｏ−、−ＮＨＣＨ_２ＣＨ（ＣＨ_３）Ｏ−、−ＮＨＣ_６Ｈ_４Ｏ−、−Ｎ（Ｃ_２Ｈ_５）Ｃ_６Ｈ_４Ｏ−、−ＮＨＣ_１０Ｈ_６Ｏ−、−Ｎ（ＣＨ_２ＣＨ_２）_２ＣＨＯ−、−Ｎ（ＣＨ_２ＣＨ_２）_２ＮＣＨ_２ＣＨ_２Ｏ−、−Ｎ（ＣＨ_２ＣＨ_２ＯＨ）ＣＨ_２ＣＨ_２Ｏ−、−Ｎ（ＣＨ_２ＣＨ_２ＣＨ_２ＯＨ）ＣＨ_２ＣＨ_２ＣＨ_２Ｏ−、−Ｎ（ＣＨ_２ＣＨ（ＣＨ_３）ＯＨ）ＣＨ_２ＣＨ（ＣＨ_３）Ｏ−、−Ｎ（ＣＨ_２ＣＨ_２ＣＨ_２ＣＨ_２ＯＨ）ＣＨ_２ＣＨ_２ＣＨ_２ＣＨ_２Ｏ−、−ＮＨＣＨ_２Ｃ_６Ｈ_４Ｏ−、−ＮＨＣ_６Ｈ_１１Ｏ−、又は−Ｎ（Ｃ_３Ｈ_７）Ｃ_６Ｈ_４Ｏ−であり、Ｒ^４はアルキレン基であり、Ｒ^５はアルコキシ基であり、Ｒ^６及びＲ^７はそれぞれ独立にアルコキシ基又はアルキル基である。）

(In the equation, M ¹ and M ² are the same as above, and R ¹ is S, O, -NHCH ₂ CH ₂ O-, -N (CH ₃ ) CH ₂ CH ₂ O-, -N (C ₃ H). ₇ ) CH ₂ CH ₂ O-, -NHCH ₂ CH ₂ CH ₂ CH ₂ O-, -N (C ₂ H ₅ ) CH ₂ CH ₂ CH ₂ CH ₂ O-, -NHCH ₂ (CH ₂ ) ₈ CH ₂ O-, -NHCH ₂ CH (CH ₃ ) O-, -NHC ₆ H ₄ O-, -N (C ₂ H ₅ ) C ₆ H ₄ O-, -NHC ₁₀ H ₆ O-, -N (CH ₂₎ CH ₂ ) ₂ CHO-, -N (CH ₂ CH ₂ ) ₂ NCH ₂ CH ₂ O-, -N (CH ₂ CH ₂ OH) CH ₂ CH ₂ O-, -N (CH ₂ CH ₂ CH ₂ OH) CH ₂ CH ₂ CH ₂ O-, -N (CH ₂ CH (CH ₃ ) OH) CH ₂ CH (CH ₃ ) O-, -N (CH ₂ CH ₂ CH ₂ CH ₂ OH) CH ₂ CH ₂ CH ₂ CH ₂ O-, -NHCH ₂ C ₆ H ₄ O-, -NHC ₆ H ₁₁ O-, or -N (C ₃ H ₇ ) C ₆ H ₄ O-, where R ⁴ is an alkylene group and R ⁵ is an alkoxy group, and R ⁶ and R ⁷ are independently alkoxy groups or alkyl groups.)

In Formula (3), the number of carbon atoms in the alkylene group ^{R 4} is not particularly limited, preferably 1 to 40, more preferably from 1 to 30. The number of carbon atoms in the alkoxy groups of R ^{5 to} R ⁷ is not particularly limited, but is preferably 1 to 30, and more preferably 1 to 20. The number of carbon atoms of the alkyl groups of R ⁶ and R ⁷ is not particularly limited, but is preferably 1 to 30, and more preferably 1 to 20.

（式中、Ｍ^１、Ｍ^２、及びＲ^５〜Ｒ^７は前記と同じであり、Ｒ^８は水素又はアルキル基であり、Ｒ^９はアルキレン基又はアルキレンオキシ基であり、Ｒ^８とＲ^９は互いに結合して環を形成してもよい。）

(In the formula, M ¹ , M ² and R ^{5 to} R ⁷ are the same as above, R ⁸ is a hydrogen or alkyl group, R ⁹ is an alkylene group or an alkyleneoxy group, and R ⁸ and R ⁹ May combine with each other to form a ring.)

In the general formula (4), the number of carbon atoms of the alkoxy groups of R ^{5 to} R ⁷ is not particularly limited, but is preferably 1 to 30, and more preferably 1 to 20. The number of carbon atoms of the alkyl groups of R ⁶ and R ⁷ is not particularly limited, but is preferably 1 to 30, and more preferably 1 to 20. The number of carbon atoms of the alkyl group of R ⁸ is not particularly limited, but is preferably 1 to 30, and more preferably 1 to 20. The carbon number of the alkylene group or the alkyleneoxy group of R ⁹ is not particularly limited, but is preferably 1 to 20, and more preferably 1 to 15. Examples of the ring formed by combining R ⁸ and R ⁹ include a 5-membered ring and a 6-membered ring, and the ring is bonded to R ⁸ and R ⁹ to form a propantriyl group (5-membered ring). Case), butantryyl group (when forming a 6-membered ring), etc. are formed.

The triazinedithiol-based compound represented by the general formula (1) can be produced by a known method.

For example, the triazinedithiol-based compound represented by the general formula (2) can be synthesized by mixing triazinetrithiol or a derivative thereof with amines represented by NHR ² R ³ and reacting them. .. In this reaction, hydrogen sulfide is produced as a by-product.

The triazine dithiol-based compound represented by the general formula (3) is obtained by mixing triazine trithiol or a derivative thereof with an alkoxysilylalkyl isocyanate represented by NCO-R ^4- SiR ⁵ R ⁶ R ⁷ . It can be synthesized by reacting. Examples of the alkoxysilylalkyl isocyanate include 3-trimethoxysilylpropyl isocyanate and 3-triethoxysilylpropyl isocyanate.

（式中、Ｒ^５〜Ｒ^９は前記と同じである。） The triazinedithiol-based compound represented by the general formula (4) is prepared by mixing triazinetrithiol or a derivative thereof with an epoxy group-containing alkoxysilane represented by the following general formula (5) and reacting them. Can be synthesized.

(In the formula, R ^{5 to} R ⁹ are the same as described above.)

Examples of the epoxy group-containing alkoxysilane include diethoxy (3-glycidyl) methylsilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidylpropyl (dimethoxy) methylsilane, and 3-glycidylpropyltrimethoxysilane. , Diethoxy (3-glycidyloxy) methylsilane, 3-glycidyloxypropyl (dimethoxy) methylsilane, 3-glycidyloxypropyltrimethoxysilane and the like.

The reaction is preferably carried out by mixing the raw materials by dispersing or dissolving them in a solvent, and further causing a heating reaction. Thereby, the target product can be easily synthesized in a short time.

Solvents include, for example, water; alcohols such as methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, carbitol, and cellsolve; ketones such as acetone, methyl ethyl ketone, and cyclohexanone; ethyl acetate, methyl benzoate, phthalic acid. Ethers such as diethyl, diethyl adipate, dibutyl ether, and anisole; aromatic hydrocarbons such as benzene, toluene, xylene, and decalin; polar solvents such as dimethylformamide, dimethylsulfoxide, hexamethylphosphoamide, and methylpyrrolidone. , Or a mixed solvent thereof and the like.

The concentration of triazine trithiol or a derivative thereof in the solvent is not particularly limited, but is usually 0.1 to 500 g / L, preferably 1 to 100 g / L. When the concentration of triazine trithiol or a derivative thereof is less than 1 g / L, the reaction efficiency tends to be poor, while when the concentration exceeds 100 g / L, the viscosity of the solution or dispersion medium becomes too high and stirring is performed. Is difficult, and a uniform reaction is less likely to occur.

The reaction temperature cannot be uniquely set because it is related to the boiling point of the solvent used, but is usually 0 to 200 ° C, preferably 30 to 160 ° C. Below 30 ° C., the reaction time tends to be long and the productivity tends to decrease. On the other hand, if the temperature exceeds 160 ° C., the reaction rate is increased and the productivity is improved, but by-products such as dimers are produced, and a special operation may be required for separation from the target product.

After completion of the reaction, the triazinedithiol compound can be obtained as white crystals or liquid by distilling off the solvent, which can be purified by solvent extraction or washing, or by distillation or crystallization. Is. When a by-product is produced, a step of converting the target product into a sodium salt in water, removing the insoluble material, and neutralizing the solubilized product with a 1% -HCl solution to purify the product is added. Is preferable.

The content of the triazinedithiol-based compound in the thermally conductive insulating rubber composition is not particularly limited, but from the viewpoint of obtaining excellent thermal conductivity, it is preferably 5 × ^10-7 to 100 parts by mass of the inorganic filler. 5 parts by mass, more preferably 1 × 10 ^-6 to 4 parts by mass, further preferably 1.5 × 10 ^{-6 to} 3 parts by mass, and less than 5 × 10 ^-7 parts by mass, thermal conductivity and dispersibility. Tends to decrease, and if it exceeds 5 parts by mass, the cost tends to increase.

<Other ingredients>
It is preferable to add an antioxidant such as an aromatic amine-based, a hindered phenol-based, a phosphorus-based, and a sulfur-based antioxidant to the thermally conductive insulating rubber composition. These may be used alone or in combination of two or more.

Examples of the aromatic amine-based antioxidant include phenylnaphthylamine, 4,4'-dimethoxydiphenylamine, 4,4'-bis (α, α-dimethylbenzyl) diphenylamine, 4-isopropoxydiphenylamine and the like. These may be used alone or in combination of two or more.

Examples of the hindered phenolic antioxidant include 3,5-di-t-butyl-4-hydroxy-toluene and n-octadecyl-β- (4'-hydroxy-3', 5'-di-t-. Butylphenyl) propionate, tetrakis [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6'-tris (3,5-di-t-Butyl-4-hydroxybenzyl) benzene, calcium (3,5-di-t-butyl-4-hydroxy-benzyl-monoethyl-phosphate), triethylene glycol-bis [3 -(3-t-Butyl-5-methyl-4-hydroxyphenyl) propionate], penterislityl-tetrakis [3- (3,5-di-t-butylanilino) -1,3,5-triazine, 3,9- Bis [1,1-dimethyl-2- {β- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] 2,4,8,10-tetraoxaspiro [5,5] Undecane, bis [3,3-bis (4'-hydroxy-3'-t-butylphenyl) butyl] glycol ester, triphenol, 2,2'-ethylidenebis (4,6-di-t-butylphenol), N, N'-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine, 2,2'-oxamidbis [ethyl-3- (3,5-di-t-butyl) -4-Hydroxyphenyl) propionate], 1,1,3-tris (3', 5'-di-t-butyl-4'-hydroxybenzyl) -S-triazine-2,4,6 (1H, 3H, 5H) -trione, 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, 3,5-di-t-butyl-4-hydroxyhydrocinnamic acid Hydtriester with -1,3,5-tris (2-hydroxyethyl) -S-triazine-2,4,6 (1H, 3H, 5H), and N, N-hexamethylenebis (3,5-di) -T-Butyl-4-hydroxy-hydrocinnaamide) and the like. These may be used alone or in combination of two or more.

Examples of phosphorus-based antioxidants include phosphorus-containing compounds such as phosphoric acid, phosphorous acid, hypophosphorous acid derivatives, phenylphosphonic acid, polyphosphonates, and diphosphite-based compounds. Specific examples include triphenylphosphine, diphenyldecylphosphine, phenyldiisodecylphosphine, tri (nonylphenyl) phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, and bis ( 2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite and the like can be mentioned. These may be used alone or in combination of two or more.

Examples of the sulfur-based antioxidant include sulfur-containing compounds such as thioether-based, dithioate-based, mercaptobenzimidazole-based, thiocarbanilide-based, and thiodipropion ester-based. Specific examples include dilaurylthiodipropionate, distearylthiodipropionate, didodecylthiodipropionate, ditetradecylthiodipropionate, dioctadecylthiodipropionate, pentaerythritol tetrakis (3-dodecylthiopro). Pionate), thiobis (N-phenyl-β-naphthylamine), 2-mercaptobenzothiazole, 2-mercaptobenzimidazole, tetramethylthiuram monosulfide, tetramethylthiuram disulfide, nickeldibutyldithiocarbamate, nickelisopropylxanthate, and Examples thereof include trilauryl trithiophosphite. These may be used alone or in combination of two or more.

The compounding (content) amount of the antioxidant is preferably 0.01 to 3 parts by mass, more preferably 0.05 to 2 parts by mass, and further preferably 0.1 to 1 part by mass with respect to 100 parts by mass of rubber. is there. When two or more kinds of antioxidants are blended, the total amount of the antioxidants blended is preferably 5 parts by mass or less.

If necessary, a cross-linking agent may be added to the thermally conductive insulating rubber composition as long as the effects of the present invention are not impaired. Examples of the cross-linking agent include epoxy-based cross-linking agents, carbodiimide-based cross-linking agents, isocyanate-based cross-linking agents, acid anhydride-based cross-linking agents, silanol-based cross-linking agents, melamine resin-based cross-linking agents, metal salt-based cross-linking agents, and metal chelate-based cross-linking agents. Examples thereof include agents and amino resin-based cross-linking agents. These may be used alone or in combination of two or more.

In addition to the antioxidant and the cross-linking agent, various additives can be added to the thermally conductive insulating rubber composition depending on the purpose. Examples of the additive include light stabilizers such as hindered amines, benzotriazoles, benzophenones, benzoates, triazoles, nickels, and salicyls, lubricants, fillers, flame retardants, flame retardants, and mold release agents. Agents, antistatic agents, molecular modifiers such as peroxides, metal deactivators, organic and inorganic nucleating agents, neutralizing agents, antioxidants, antibacterial agents, optical brighteners, organic and inorganic Examples thereof include based pigments, organic and inorganic phosphorus compounds used for the purpose of imparting flame retardancy and thermal stability. When the above additives are blended, the content (total content when a plurality of additives are used) is preferably 30% by mass or less, more preferably 20 in the heat conductive insulating rubber composition. It is mass% or less, more preferably 10 mass% or less, and particularly preferably 5 mass% or less.

<Thermal conductive insulating rubber composition>
The method for producing the thermally conductive insulating rubber composition of the present invention is not particularly limited, and it can be produced by mixing the above components. In the present invention, the inorganic filler and the triazinedithiol-based compound are brought into contact with each other from the viewpoint of enhancing the dispersibility of the inorganic filler in the composition and facilitating the formation of a continuum formed by connecting the inorganic fillers. Then, the triazinedithiol compound is adhered to the surface of the inorganic filler to obtain a surface-modified inorganic filler, and then the obtained surface-modified inorganic filler is dispersed in the rubber (rubber kneaded product) to have thermal conductivity. It is preferable to produce an insulating rubber composition.

The method of contacting the inorganic filler with the triazinedithiol-based compound is not particularly limited, and for example, a method of mixing the inorganic filler with the triazinedithiol-based compound, a solution of the triazinedithiol-based compound in a solvent, or Examples thereof include a method in which the inorganic filler is immersed in a dispersion liquid in which the triazinedithiol-based compound is dispersed in a solvent, the inorganic filler is taken out, and then dried.

<Thermal conductive insulated rubber molded body>
The thermally conductive insulating rubber molded product of the present invention is obtained by molding and vulcanizing (crosslinking) the thermally conductive insulating rubber composition. The method for producing the thermally conductive insulating rubber molded product is not particularly limited, but it is preferable to press and / or heat the thermally conductive insulating rubber composition for molding. Examples of the molding method include an extrusion molding method, a mold molding method, and a hot press method. The vulcanization conditions for curing the thermally conductive insulating rubber composition vary depending on the use of the rubber molded product and are not particularly limited. For example, in the case of a rubber composition for anti-vibration rubber, Usually, the vulcanization temperature is about 140 to 180 ° C., and the vulcanization time is about 5 to 120 minutes.

The thermally conductive insulating rubber composition of the present invention can dramatically improve the tensile characteristics and elongation characteristics of rubber while maintaining good heat resistance. Generally, it is considered that heat resistance and tensile properties are in a trade-off relationship, but the thermally conductive insulating rubber composition of the present invention can significantly extend the life of the rubber molded product as compared with the conventional one. it can.

The shape of the thermally conductive insulating rubber molded product of the present invention can be appropriately selected depending on the intended use, and examples thereof include a sheet shape, a plate shape, a strip shape, a film shape, and a block shape.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto, and can be appropriately modified and carried out within a range that can be adapted to the above-mentioned and the purposes described below. And all of them are included in the technical scope of the present invention.

Manufacturing example 1
(Production of triazinedithiol-based compound represented by the following formula (6))

17.72 g (0.1 mol) of triazine trithiol and 0.102 mol of 3-triethoxysilylpropylamine were added to 100 mL of toluene to give a mixture. Here, triazine trithiol is dispersed in toluene, and 3-triethoxysilylpropylamine is dissolved in toluene. Then, the mixture was stirred at 140 ° C. for 30 minutes to allow the reaction to proceed. After completion of the reaction, toluene was distilled off under reduced pressure and recovered, and the gas component was absorbed in a 20% NaOH aqueous solution to remove the generated hydrogen sulfide. The obtained solid was washed with ethyl ether to remove a trace amount of unreacted amine to obtain a crude triazinedithiol compound in a yield of 96% or more. Then, the crude triazinedithiol compound was recrystallized from isopropanol and purified to obtain a triazinedithiol compound represented by the above formula (6). The melting point of the triazinedithiol-based compound after recrystallization was 235 to 236 ° C., and the elemental analysis values were C: 40.2%, N: 16.0%, and S: 18.2%. A melting point measuring instrument manufactured by Mita Riken Kogyo Co., Ltd. was used for melting point analysis. A Yanagimoto CHN coder was used for carbon and nitrogen analysis, and a CHN coder manufactured by Parkin Elma was used for sulfur analysis.

Manufacturing example 2
(Manufacture of surface-modified aluminum nitride filler (B1))
The triazine dithiol compound produced in Production Example 1 was dissolved in ion-exchanged water to obtain an aqueous solution containing 0.1 wt% of the triazine dithiol compound. Then, 100 g of an aluminum nitride filler (FAN-05 manufactured by Furukawa Electronics Co., Ltd.) is immersed in the aqueous solution for 10 minutes, then taken out and dried at 100 ° C. for 60 minutes to obtain a surface-modified aluminum nitride filler (B1). Obtained.

Manufacturing example 3
(Manufacture of surface-modified boron nitride filler (B2))
The triazine dithiol compound produced in Production Example 1 was dissolved in ion-exchanged water to obtain an aqueous solution containing 0.1 wt% of the triazine dithiol compound. Then, 100 g of a boron nitride filler (SP-2 manufactured by Denka Co., Ltd.) is immersed in the aqueous solution for 10 minutes, then taken out and dried at 100 ° C. for 60 minutes to obtain a surface-modified boron nitride filler (B2). It was.

Manufacturing example 4
(Rubber kneaded product (A1) to (A4))
The raw materials shown in Table 1 were kneaded with the formulations shown in Table 1 to produce rubber kneaded products (A1) and (A2). The raw materials shown in Table 1 are as follows. The following commercially available products were used as the rubber kneaded products (A3) and (A4).
NR: Natural rubber (manufactured by CRK, trade name "RSS # 4")
EPDM: Ethylene-propylene-diene rubber (manufactured by JSR, trade name "EP96", ENB content 6.0% by mass, ethylene content 66% by mass (polymer component: 30phr, oil component: 15phr))
Zinc oxide: ZnO
Anti-aging agent: 2,2,4-trimethyl-1,2-dihydroquinoline polymer (manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd., trade name "Nocrack 224")
Wax: Micro Chris Wax (manufactured by Seiko Kagaku Co., Ltd., trade name "Santite S")
Organic Peroxide (DCP): Dicumyl Peroxide Crosslinking Agent: Amilphenol Disulfide Polymer (manufactured by Elf-Atchem-Japan, trade name "VULTAC5")
Rubber kneaded product (A3): Santoplane 211-55 (manufactured by ExxonMobil)
Rubber kneaded product (A4): Tough Tech H1042 (manufactured by Asahi Kasei Corporation)

Examples 1-8, Comparative Examples 1-4
(Manufacture of thermally conductive insulating rubber composition)
After mixing the rubber kneaded product and filler shown in Table 2 with the formulation shown in Table 2, the obtained mixture was put into a tabletop kneader (Laboplast Mill 20C200) manufactured by Toyo Seiki Co., Ltd. preheated to 160 ° C. The mixture was kneaded at 100 rpm for 10 minutes to obtain a thermally conductive insulating rubber composition. The fillers B1 and B2 shown in Table 2 are as follows.
B1: Surface-modified aluminum nitride filler (B1) produced in Production Example 2
B2: Surface-modified boron nitride filler (B2) produced in Production Example 3

〔Evaluation method〕
The thermal conductivity, heat resistance, and moist heat resistance were evaluated by the following methods.
(Preparation of evaluation sheet sample)
The evaluation sheet sample was prepared using a heat press machine (SA-302-I, manufactured by Tester Sangyo Co., Ltd.). The thermally conductive insulating rubber compositions prepared in Examples and Comparative Examples are placed in a mold having a predetermined thickness, vulcanized at 140 ° C. for 10 minutes while applying a load of 30 kgf / cm ² , and cured to obtain a predetermined value. A sheet sample for evaluating the thickness was obtained.

(Measurement of thermal conductivity)
The specific heat was measured using DSC2920 manufactured by TA Instruments Co., Ltd. 10.0 mg of the thermally conductive insulating rubber composition (sample) prepared in Examples and Comparative Examples was placed in an aluminum pan, and the temperature was raised from room temperature to 200 ° C. at a temperature of 10 ° C./min to reach 200 ° C. Was held for 5 minutes. Then, the temperature was lowered at 10 ° C./min. Similarly, 26.8 mg of sapphire as a reference substance was placed in an aluminum pan and measured under the same conditions. Further, an empty aluminum pan containing no sample as a blank was measured under the same conditions. The value of Heat Flow at 23 ° C. of each DSC curve was read, and the specific heat capacity was calculated by the following formula.

Cp = (h / H) x (m'/ m) x C'p

Cp: Specific heat of the sample C'p: Specific heat of the reference material (sapphire) at 23 ° C. h: Difference between the DSC curve of the blank and the sample H: Difference between the DSC curves of the blank and the reference material (sapphire) m: Mass of the sample (g) )
m': Mass (g) of reference substance (sapphire)

The specific gravity was measured using an automatic hydrometer DH100 manufactured by Toyo Seiki Co., Ltd. The prepared evaluation sheet sample was heat-pressed to obtain a sheet having a thickness of 0.5 mm. Then, the sheet was cut into a size of 10 mm × 10 mm to obtain a sample for specific gravity measurement. Using the prepared sample for specific gravity measurement, the specific gravity was measured by the underwater substitution method.
The thermal diffusivity was measured using a thermal diffusivity measuring device ai-phase Mobile 1 manufactured by iPhase Co., Ltd. The prepared evaluation sheet sample was heat-pressed to obtain a sheet having a thickness of 0.5 mm. The thermal diffusivity in the thickness direction was measured using the prepared sheet.
Then, the thermal conductivity was calculated by the following formula from the specific heat, specific gravity, and thermal diffusivity obtained by the above method.

Thermal conductivity (W / m · K) = specific gravity x specific heat (J / g · K) x thermal diffusivity (m ² / sec)

(Evaluation of heat resistance)
The prepared evaluation sheet sample was heat-pressed to obtain a sheet having a thickness of 1 mm. Then, the sheet was cut into a size of 10 mm × 50 mm to obtain a sample for heat resistance evaluation. A sample for heat resistance evaluation was put into a constant temperature bath, and after 96 hours at a temperature of 120 ° C., the tensile elongation was measured and the temperature at which it became 50% of the initial value was examined. Then, it was evaluated according to the following criteria. The higher the temperature, which is 50% of the initial value, the higher the heat resistance.
⊚: 120 ° C or higher ○: 110 ° C or higher and lower than 120 ° C Δ: 100 ° C or higher and lower than 110 ° C ×: less than 100 ° C

(Evaluation of moisture and heat resistance)
The prepared evaluation sheet sample was heat-pressed to obtain a sheet having a thickness of 1 mm. Then, the sheet was cut into a size of 10 mm × 50 mm to obtain a sample for evaluation of moisture resistance and heat resistance. The sample for evaluation of moisture resistance and heat resistance was put into a constant temperature and humidity chamber, and the expansion coefficient of the sample under the condition of 85 ° C. × 85% Rh was observed. The length, width, and thickness (mm) of the sample before and after 300 hours of charging into the constant temperature and humidity chamber were measured, and the expansion rate (%) in each direction was calculated. Furthermore, the product was taken and the coefficient of thermal expansion (%) was calculated. At this time, the expansion coefficient before the constant temperature and humidity chamber is set to 100%. A constant pressure caliper was used for the measurement. The smaller the coefficient of thermal expansion, the more preferable. When the coefficient of thermal expansion is less than 110%, the deterioration of brittleness is small and good. If the coefficient of thermal expansion is 110% or more, brittleness is deteriorated, so that it is not preferable to use it under high humidity.

The thermally conductive insulating rubber molded body of the present invention is useful as a material for automobile members and members such as electronic circuit boards that are required to have insulation and heat dissipation.

Claims (10)

A thermally conductive insulating rubber composition containing a rubber, an inorganic filler, and a triazinedithiol-based compound represented by the following general formula (1).

(In the formula, M ¹ and M ² are independently H, Li, Na, K, or Cs, R ¹ is S, O, or NR ³ , and R ³ is H, or an alkyl group, halogenated. Alkyl group, hydroxyalkyl group, alkoxyalkyl group, alkenyl group, halogenated alkenyl group, hydroxyalkenyl group, alkoxyalkenyl group, phenyl group, halogenated phenyl group, hydroxyphenyl group, alkoxyphenyl group, biphenyl group, halogenated biphenyl group , Hydroxybiphenyl group, alkoxybiphenyl group, naphthyl group, naphthyl halide group, hydroxynaphthyl group, alkoxynaphthyl group, carboxyl group, ester group, urethane group, azo group, cyano group, amino group, amide group, and alkoxysilyl group. It is an organic group having at least one functional group selected from the group consisting of, R ² is the same as the organic group, or NR ³ and R ² form a heterocycle). The thermally conductive insulating rubber composition according to claim 1, wherein the triazinedithiol-based compound is at least one of the triazinedithiol-based compounds represented by the following general formulas (2) to (4).

(In the formula, M ¹ , M ² , R ² and R ³ are the same as above.)

(In the equation, M ¹ and M ² are the same as above, and R ¹ is S, O, -NHCH ₂ CH ₂ O-, -N (CH ₃ ) CH ₂ CH ₂ O-, -N (C ₃ H). ₇ ) CH ₂ CH ₂ O-, -NHCH ₂ CH ₂ CH ₂ CH ₂ O-, -N (C ₂ H ₅ ) CH ₂ CH ₂ CH ₂ CH ₂ O-, -NHCH ₂ (CH ₂ ) ₈ CH ₂ O-, -NHCH ₂ CH (CH ₃ ) O-, -NHC ₆ H ₄ O-, -N (C ₂ H ₅ ) C ₆ H ₄ O-, -NHC ₁₀ H ₆ O-, -N (CH ₂₎ CH ₂ ) ₂ CHO-, -N (CH ₂ CH ₂ ) ₂ NCH ₂ CH ₂ O-, -N (CH ₂ CH ₂ OH) CH ₂ CH ₂ O-, -N (CH ₂ CH ₂ CH ₂ OH) CH ₂ CH ₂ CH ₂ O-, -N (CH ₂ CH (CH ₃ ) OH) CH ₂ CH (CH ₃ ) O-, -N (CH ₂ CH ₂ CH ₂ CH ₂ OH) CH ₂ CH ₂ CH ₂ CH ₂ O-, -NHCH ₂ C ₆ H ₄ O-, -NHC ₆ H ₁₁ O-, or -N (C ₃ H ₇ ) C ₆ H ₄ O-, where R ⁴ is an alkylene group and R ⁵ is an alkoxy group, and R ⁶ and R ⁷ are independently alkoxy groups or alkyl groups.)

(In the formula, M ¹ , M ² and R ^{5 to} R ⁷ are the same as above, R ⁸ is a hydrogen or alkyl group, R ⁹ is an alkylene group or an alkyleneoxy group, and R ⁸ and R ⁹ May combine with each other to form a ring.) The heat conductive insulating rubber composition according to claim 1 or 2, wherein the inorganic filler contains at least one selected from the group consisting of an aluminum nitride filler and a boron nitride filler. The heat conductive insulating rubber composition according to any one of claims 1 to 3, wherein the content of the inorganic filler is 20 to 400 parts by mass with respect to 100 parts by mass of the rubber. The thermally conductive insulating rubber composition according to any one of claims 1 to 4, wherein the content of the triazine dithiol compound is 5 × ^10-7 to 5 parts by mass with respect to 100 parts by mass of the inorganic filler. The heat conductive insulating rubber composition according to any one of claims 1 to 5, wherein the rubber comprises at least two kinds of rubbers selected from natural rubber, isoprene rubber, butadiene rubber, and ethylene-propylene-diene rubber. A thermally conductive insulating rubber molded body obtained from the thermally conductive insulating rubber composition according to any one of claims 1 to 6. The thermally conductive insulating rubber molded body according to claim 7, wherein the thermally conductive insulating rubber molded body is a thermally conductive insulating rubber sheet. The method for producing a thermally conductive insulating rubber molded product according to claim 7 or 8, wherein the inorganic filler is brought into contact with the triazinedithiol-based compound, and the triazinedithiol-based compound is adhered to the surface of the inorganic filler. A step of obtaining the surface-modified inorganic filler, a step B of dispersing the surface-modified inorganic filler in the rubber to obtain the thermally conductive insulating rubber composition, and a step of molding the thermally conductive insulating rubber composition. A method for producing a thermally conductive insulating rubber molded body containing C. The method for producing a thermally conductive insulating rubber molded product according to claim 9, wherein in the step C, the thermally conductive insulating rubber composition is pressurized and / or heated to be molded.