Rubber composition, crosslinked body, molded article, and heat-dissipating sheet

Abstract

To provide a rubber composition having superior mixing processability, yielding a molded article less prone to tackiness, and suitable for manufacturing a heat-dissipating sheet.SOLUTION: A rubber composition containing a rubber component (A), a filler (B), and a graft-modified ethylene-α-olefin copolymer (C) satisfying specific requirements, the filler (B) having a thermal conductivity of 10 W / m K or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a rubber composition, a crosslinked product, a molded product, and a heat-dissipating sheet. [Background technology]

[0002] In recent years, electronic devices have become increasingly sophisticated and miniaturized, resulting in increasingly dense electronic components. Therefore, controlling the heat generated by these devices has become a major challenge, ensuring their normal operation and longevity. To address this challenge, methods have been developed to dissipate heat from the device itself, and many electronic devices incorporate heat dissipation components such as heat sinks, heat spreaders, heat pipes, and cooling fans. Furthermore, some small devices, such as mobile phones, are designed to use the housing itself as a heat dissipation component, dissipating heat to the outside. These electronic devices use materials known as thermal interface materials (TIMs) to improve thermal conductivity between heat-generating elements and heat dissipation components, as well as between heat dissipation components themselves.

[0003] TIMs are broadly composed of two components. One is the filler, which ensures thermal conductivity. This is made up of highly thermally conductive metal oxides, metal nitrides, metal hydroxides, metal carbides, and metal powders. The other component is the binder, which holds the filler in place and keeps the TIM in its desired shape. While the binder varies greatly depending on the type of TIM, various organic materials are used, including curable resins such as silicone and acrylic, thermoplastic resins, elastomers, oils, and waxes.

[0004] Among these, silicone compounds are often used as binders from the viewpoint of the heat resistance stability of the TIM itself. For example, Patent Document 1 discloses a thermal grease containing aluminum nitride, zinc oxide, and silicone oil.

[0005] However, silicone compounds themselves contain low-molecular-weight siloxanes, which are gradually decomposed from silicone compounds and then precipitate on electronic circuits as insulating foreign matter such as silicon dioxide, which can cause contact failures. Therefore, active efforts are being made to develop non-silicone TIMs. Known examples of such non-silicone TIMs include the thermally conductive compositions described in Patent Documents 2 and 3.

[0006] Patent Document 4 discloses a resin composition containing a component containing one or more selected from graft-modified α-olefin (co)polymers and α-olefin (co)polymers that satisfy specific requirements, a binder containing one or more compounds selected from an olefin-based resin, a styrene-based thermoplastic elastomer, and a wax, and a filler, and describes that the resin composition can be used as a phase change material (PCM). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 10-110179 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-121354 [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-88384 [Patent Document 4] Patent Publication No. 2021-24942 Summary of the Invention [Problem to be solved by the invention]

[0008] However, conventional thermally conductive compositions are hard and brittle, making them poorly processable for mixing, and sheets obtained from the resin compositions are sticky and difficult to handle, or are so hard and brittle that they cannot adhere to heat-generating elements and heat-dissipating members, making it difficult to efficiently transfer heat from the heat-generating elements to the heat-dissipating members.

[0009] The present invention has been made in view of the above, and an object of the present invention is to provide a rubber composition that has excellent mixing processability, produces molded products that are less sticky, and is suitable for producing heat-dissipating sheets. [Means for solving the problem]

[0010] The present inventors have conducted extensive research to solve the above-mentioned problems. As a result, they have found that the above-mentioned problems can be solved by the following configuration examples, and have completed the present invention. The configuration examples of the present invention are as follows.

[0011] [1] The rubber composition contains a rubber component (A), a filler (B), and a graft-modified ethylene-α-olefin copolymer (C) that satisfies the following requirements (c-1) to (c-6): The filler (B) has a thermal conductivity of 10 W / m·K or more. Requirement (c-1): The graft-modified ethylene-α-olefin copolymer (C) contains a main chain portion derived from the ethylene-α-olefin copolymer (C0). Requirement (c-2): The graft-modified ethylene-α-olefin copolymer (C) contains a graft portion derived from at least one unsaturated carboxylic acid monomer selected from the group consisting of unsaturated carboxylic acids having 3 to 10 carbon atoms and derivatives of the unsaturated carboxylic acids. Requirement (c-3) The acid value is 10 to 150 mgKOH / g. Requirement (c-4) The apparent viscosity at 150°C is 20 to 1,500 mPa·s. Requirement (c-5): The weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) is 1,500 to 25,000. Requirement (c-6) No melting point is observed by differential scanning calorimetry (DSC).

[0012] [2] The rubber composition according to [1], wherein the rubber component (A) is an ethylene-α-olefin-non-conjugated polyene copolymer rubber.

[0013] [3] The rubber composition according to [1] or [2], wherein the filler (B) is an aluminum compound.

[0014] [4] The rubber composition according to [3], wherein the aluminum compound is aluminum nitride.

[0015] [5] The rubber composition according to any one of [1] to [4], wherein the graft-modified ethylene-α-olefin copolymer (C) is a graft-modified ethylene-propylene copolymer.

[0016] [6] The rubber composition according to any one of [1] to [5], wherein the content of the filler (B) is 100 to 2000 parts by mass and the content of the graft-modified ethylene-α-olefin copolymer (C) is 1 to 150 parts by mass, relative to 100 parts by mass of the rubber component (A).

[0017] [7] A crosslinked body obtained by crosslinking the rubber composition according to any one of [1] to [6].

[0018] [8] A molded article comprising the rubber composition according to any one of [1] to [6].

[0019] [9] A heat-dissipating sheet comprising the rubber composition according to any one of [1] to [6].

[0020]

[10] A method for producing a rubber composition, comprising the step of mixing a rubber component (A), a filler (B) having a thermal conductivity of 10 W / m·K or more, and a graft-modified ethylene-α-olefin copolymer (C) that satisfies the following requirements (c-1) to (c-6): Requirement (c-1): The graft-modified ethylene-α-olefin copolymer (C) contains a main chain portion derived from the ethylene-α-olefin copolymer (C0). Requirement (c-2): The graft-modified ethylene-α-olefin copolymer (C) contains a graft portion derived from at least one unsaturated carboxylic acid monomer selected from the group consisting of unsaturated carboxylic acids having 3 to 10 carbon atoms and derivatives of the unsaturated carboxylic acids. Requirement (c-3) The acid value is 10 to 150 mgKOH / g. Requirement (c-4) The apparent viscosity at 150°C is 20 to 1,500 mPa·s. Requirement (c-5): The weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) is 1,500 to 25,000. Requirement (c-6) No melting point is observed by differential scanning calorimetry (DSC).

[0021]

[11] The method for producing a rubber composition according to

[10] , further comprising the step of producing the graft-modified ethylene-α-olefin copolymer (C) by the following method (α): Method (α): a step (S1) of obtaining an ethylene-α-olefin copolymer (C0) by copolymerizing ethylene and an α-olefin in the presence of an olefin polymerization catalyst containing a bridged metallocene compound (P) represented by the following formula [I] and at least one compound (Q) selected from the group consisting of an organometallic compound (Q-1), an organoaluminum oxy compound (Q-2), and a compound (Q-3) that reacts with the bridged metallocene compound (P) to form an ion pair; a step (S2) of adding the unsaturated carboxylic acid monomer to the ethylene-α-olefin copolymer (C0) to graft-modify the ethylene-α-olefin copolymer (C0); A method comprising:

[0022] [ka]

[0023] [In formula [I], R 1 , R 2 , R 3 , R4 , R 5 , R 8 , R 9 and R 12 are each independently a hydrogen atom, a hydrocarbon group, or a silicon-containing hydrocarbon group, and R 1 ~R 4 two adjacent groups may be linked to each other to form a ring structure, R 6 and R 11 are the same group and are a hydrogen atom, a hydrocarbon group, or a silicon-containing hydrocarbon group, R 7 and R 10 are the same group and are a hydrogen atom, a hydrocarbon group, or a silicon-containing hydrocarbon group, R 6 and R 7 may be bonded to a hydrocarbon having 2 to 3 carbon atoms to form a ring structure, R 10 and R 11 may be bonded to a hydrocarbon having 2 to 3 carbon atoms to form a ring structure, R 6 , R 7 , R 10 and R 11 is not a hydrogen atom at the same time, Y is a carbon atom or a silicon atom; R 13 and R 14 are each independently a hydrogen atom, a hydrocarbon group, or a silicon-containing hydrocarbon group, and may be linked together to form a ring structure, M is a titanium atom, a zirconium atom, or a hafnium atom; j is an integer from 1 to 4, Q is a halogen atom, a hydrocarbon group, an anionic ligand, or a neutral ligand capable of coordinating to a lone electron pair, and when j is an integer of 2 or greater, multiple Qs may be the same or different.

[0024]

[12] In the formula [I], R 13 and R 14

[11] The method for producing a rubber composition according to

[11] , wherein either one or both of the following are aryl groups:

[0025]

[13] In the formula [I], R 13 and R 14 are both aryl groups, and R 2 and R 3 wherein either one of the above is a saturated hydrocarbon group having 4 carbon atoms. [Effects of the Invention]

[0026] According to the present invention, it is possible to provide a rubber composition that has excellent mixing processability, produces a molded product that is less sticky, and is suitable for producing a heat-dissipating sheet. Therefore, the rubber composition according to the present invention is suitable for use in heat dissipation in electronic devices and electronic components that generate heat, and specifically, is suitable for use as a TIM such as a heat dissipation sheet. DETAILED DESCRIPTION OF THE INVENTION

[0027] The present invention will be specifically described below. In this specification, the symbol "to" indicating a numerical range, for example "M to N", means "greater than or equal to M and less than or equal to N" unless otherwise specified.

[0028] In this specification, the term "(co)polymer" is used as a concept that encompasses both homopolymers and copolymers. In this specification, when an olefin constituting a certain (co)polymer is represented by M, the expression "structural unit derived from M" may be used, which refers to a "structural unit corresponding to M," i.e., a structural unit having a pair of bonds formed by opening the π bond constituting the double bond of M.

[0029] <Rubber composition> The rubber composition according to the present invention (hereinafter also referred to as "the composition") contains a rubber component (A), a filler (B), and a graft-modified ethylene-α-olefin copolymer (C).

[0030] <Rubber component (A)> Examples of the rubber component (A) include ethylene-α-olefin-non-conjugated polyene copolymer rubber, butyl rubber, chloroprene rubber, natural rubber, isoprene rubber, nitrile rubber, styrene-butadiene rubber, butadiene rubber, chlorosulfonated polyethylene rubber, acrylic rubber, acrylonitrile-butadiene rubber, urethane rubber, hydrogenated acrylonitrile rubber, fluororubber, and silicone rubber.

[0031] Of these, ethylene-α-olefin-non-conjugated polyene copolymer rubber is preferred as the rubber component (A) because it is excellent in various performance properties such as heat resistance, cold resistance, weather resistance, durability, impact resilience, processability, ozone resistance, chemical resistance, and electrical properties. The rubber component (A) may be used alone or in combination of two or more kinds.

[0032] [Ethylene-α-olefin-non-conjugated polyene copolymer rubber] The ethylene-α-olefin-non-conjugated polyene copolymer rubber is a copolymer rubber containing structural units derived from ethylene, structural units derived from an α-olefin having 3 or more carbon atoms, preferably 3 to 20 carbon atoms, and structural units derived from a non-conjugated polyene.

[0033] The stereoregularity and chain structure of the ethylene-α-olefin-non-conjugated polyene copolymer rubber are not particularly limited, and the geometric chemistry (e.g., cis or trans) and stereochemistry of the non-conjugated polyene in the ethylene-α-olefin-non-conjugated polyene copolymer rubber are also not particularly limited.

[0034] The composition may contain two or more kinds of ethylene-α-olefin-non-conjugated polyene copolymer rubbers. Examples of the α-olefins having 3 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 4-methyl-1-pentene, 9-methyl-1-decene, and 12-ethyl-1-tetradecene. Among these, α-olefins having 3 to 10 carbon atoms are preferred, with propylene, 1-butene, 4-methyl-1-pentene, 1-hexene, and 1-octene being more preferred, and propylene and 1-butene being particularly preferred. These α-olefins may be used alone or in combination of two or more.

[0035] Examples of the non-conjugated polyenes include linear non-conjugated dienes such as 1,4-hexadiene, 3-methyl-1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 4,5-dimethyl-1,4-hexadiene, 7-methyl-1,6-octadiene, 8-methyl-4-ethylidene-1,7-nonadiene, and 4-ethylidene-1,7-undecadiene; methyltetrahydroindene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, and 5-isopropylidene-2-norbornene. , cyclic non-conjugated dienes such as 5-vinylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, 5-vinyl-2-norbornene, 5-isopropenyl-2-norbornene, 5-isobutenyl-2-norbornene, cyclopentadiene, and norbornadiene; trienes such as 2,3-diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene, and 4-ethylidene-8-methyl-1,7-nonadiene. Among these, 1,4-hexadiene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, and a mixture of 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene are preferred, and 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, and a mixture of 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene are particularly preferred. These non-conjugated polyenes can be used alone or in combination.

[0036] The ethylene, α-olefin, and non-conjugated polyene, which are raw materials for the ethylene-α-olefin-non-conjugated polyene copolymer rubber, may be, for example, a fossil fuel-derived monomer or a biomass-derived monomer, and these monomers may be used alone or in combination of two or more.

[0037] The content of the structural units derived from ethylene in the ethylene-α-olefin-non-conjugated polyene copolymer rubber is preferably 55 to 99 mass%, more preferably 60 to 95 mass%, and even more preferably 70 to 90 mass%, relative to 100 mass% of the total of the structural units derived from ethylene and the structural units derived from the α-olefin.

[0038] The content of the structural units derived from the non-conjugated polyene in the ethylene-α-olefin-non-conjugated polyene copolymer rubber is preferably 1 to 25 parts by mass, more preferably 1 to 20 parts by mass, and even more preferably 3 to 15 parts by mass, per 100 parts by mass of the total of the structural units derived from ethylene and the structural units derived from the α-olefin.

[0039] Manufacturing method for ethylene-α-olefin-non-conjugated polyene copolymer rubber The ethylene-α-olefin-non-conjugated polyene copolymer rubber can be produced using a known polymerization catalyst such as a Ziegler-Natta catalyst, a metallocene catalyst, etc. The polymerization method is not particularly limited, and can be a liquid phase polymerization method such as a solution polymerization method, a suspension polymerization method, or a bulk polymerization method, a gas phase polymerization method, or any other known polymerization method.

[0040] Commercially available ethylene-α-olefin-non-conjugated polyene copolymer rubber The ethylene-α-olefin-non-conjugated polyene copolymer rubber may be a commercially available product, and examples of the commercially available product include "Vistalon" manufactured by Exxon Mobil Chemical Company, "Esprene" manufactured by Sumitomo Chemical Co., Ltd., and "Mitsui EPT" manufactured by Mitsui Chemicals, Inc.

[0041] [Butyl rubber] The butyl rubber is a (co)polymer containing structural units derived from isobutylene (isobutene, 2-methylpropylene). The butyl rubber may be a homopolymer of isobutylene or a copolymer of isobutylene and a comonomer other than isobutylene.

[0042] When the butyl rubber is a copolymer of isobutylene and a comonomer other than isobutylene, the comonomer may be a diene compound, a styrene compound, or the like. These comonomers may be used alone or in combination of two or more. The stereoregularity and chain structure of the copolymer are not particularly limited.

[0043] The composition may contain two or more types of butyl-based rubbers. Examples of the diene compound include butadiene, isoprene, hexadiene, and chloroprene.

[0044] Examples of the styrene-based compound include styrene, α-methylstyrene, 3-methylstyrene, and 4-methylstyrene. Of these, isoprene and 4-methylstyrene are preferred.

[0045] The content of structural units derived from isobutylene in the butyl rubber is preferably 85 to 99.8% by mass, more preferably 90 to 99.5% by mass, and even more preferably 92 to 99.5% by mass, relative to 100% by mass of the total of structural units derived from isobutylene and structural units derived from comonomers other than isobutylene.

[0046] The butyl rubber may contain a halogen, preferably chlorine or bromine, and more preferably bromine. The halogen content in the halogen-containing butyl rubber is preferably 0.1 to 5 mass %, more preferably 0.3 to 3 mass %, relative to 100 mass % of the total butyl rubber.

[0047] The butyl rubber may be a butyl rubber obtained by further secondary modification of a halogen-containing butyl rubber. That is, the butyl rubber includes butyl rubber (isobutylene-isoprene copolymer, IIR), chlorinated butyl rubber (chlorinated butyl rubber, Cl-IIR), brominated butyl rubber (brominated butyl rubber, Br-IIR), and brominated isobutylene-4-methylstyrene copolymer.

[0048] -Butyl rubber manufacturing method The method for producing the butyl rubber is not particularly limited, but for example, there is a method in which a monomer containing isobutylene is cationic polymerized at low temperature in chloromethane using aluminum chloride as an initiator.

[0049] The method for introducing a halogen into the butyl rubber is not particularly limited, and any conventionally known method can be used, such as a method of copolymerizing a halogenated monomer, a method of modifying a halogen-free butyl rubber and introducing a halogen. A common method is to introduce a halogen into a butyl rubber using a simple halogen such as chlorine or bromine in a hydrocarbon solvent such as hexane.

[0050] Commercially available butyl rubber As the butyl rubber, commercially available products may be used. Commercially available butyl rubber (IIR) includes, for example, "Butyl" manufactured by Japan Butyl Co., Ltd., "Exxon butyl rubber" manufactured by Exxon Mobil Chemical Company, and "X_Butyl RB" manufactured by Lanxees.

[0051] Commercially available chlorinated butyl rubber (Cl-IIR) includes, for example, "CHLOROBUTYL" manufactured by Nippon Butyl Co., Ltd., "Exxon chlorobutyl rubber" manufactured by Exxon Mobil Chemical Company, and "X_Butyl CB" manufactured by Lanxess.

[0052] Commercially available brominated butyl rubber (Br-IIR) includes, for example, "BROMOBUTYL" manufactured by Nippon Butyl Co., Ltd., "Exxon bromobutyl rubber" manufactured by Exxon Mobil Chemical Company, and "X_Butyl BB" manufactured by Lanxess. An example of a commercially available brominated isobutylene-4-methylstyrene copolymer is "Exxpro" manufactured by Exxon Mobil Chemical Company.

[0053] [Other Aspects of Rubber Component (A)] The rubber component (A) may be the above-mentioned compound as it is, or a modified product obtained by adding a substituent and a polar group to the above-mentioned compound (excluding the graft-modified ethylene-α-olefin copolymer (C)). The modified product may be one type or two or more types.

[0054] The modification method is not limited, and various known modification methods can be used. Examples of the modification method include oxidation reaction with oxygen or peroxide, reactions starting from a carboxyl group such as hydrolysis, saponification, esterification, and amidation, reactions with simple halogens such as chlorine and bromine, nucleophilic substitution and nucleophilic elimination reactions at a (pseudo) alkyl halide moiety with good elimination ability, and graft modification in which a vinyl compound or the like is reacted in the presence of a radical initiator.

[0055] <Filler (B)> The filler (B) is a filler component for improving the thermal conductivity of a molded article obtained from the rubber composition. The filler (B) used in the present invention is not particularly limited as long as it has a thermal conductivity of 10 W / m·K or more. The thermal conductivity of the filler (B) is preferably 15 W / m·K or more, and more preferably 20 W / m·K or more.

[0056] When the thermal conductivity of the filler (B) is 10 W / m·K or more, the thermal conductivity of the molded article obtained from the composition can be easily increased. When obtaining a heat-dissipating sheet with high electrical insulation that can be used for electronic substrates, etc., it is preferable to use a material as the filler (B) that has excellent not only thermal conductivity but also electrical insulation properties.

[0057] The filler (B) is preferably at least one selected from metal oxides, metal hydroxides, nitrides, carbides, and metals. Examples of the metal oxides include aluminum oxide, zinc oxide, magnesium oxide, silicon dioxide (in the present invention, silicon dioxide is also considered to be a metal oxide), and beryllium oxide.

[0058] The metal hydroxide may, for example, be aluminum hydroxide. Examples of the nitride include aluminum nitride, silicon nitride, and boron nitride.

[0059] Examples of the carbides include boron carbide, titanium carbide, and silicon carbide. Examples of the metal include aluminum, copper, nickel, and silver.

[0060] The filler (B) may be graphite or graphite. The filler (B) may be a mixture of these. In particular, when a heat dissipation sheet with high electrical insulation is to be obtained, the filler (B) is preferably a metal oxide, metal hydroxide, nitride, or a mixture thereof, and more preferably one or more selected from the group consisting of aluminum hydroxide, boron nitride, aluminum nitride, zinc oxide, aluminum oxide, magnesium oxide, and magnesium hydroxide.

[0061] From the viewpoints that a wide range of particle sizes can be selected industrially, that they have excellent chemical stability, are easily available, and are relatively inexpensive, aluminum compounds such as aluminum oxide, aluminum hydroxide, and aluminum nitride are preferred as filler (B), and among these, aluminum nitride is more preferred because it has excellent thermal conductivity.

[0062] The shape of the filler (B) is not particularly limited, and examples thereof include spherical, irregular, fine powder, fibrous, and scaly shapes. In order to blend the necessary amount of filler (B) so that the molded article obtained from this composition has thermal conductivity suitable for producing a heat-dissipating sheet, the shape of the filler (B) is preferably spherical. Here, spherical may mean not only a perfect sphere but also a rounded shape.

[0063] The average particle size of the filler (B) is preferably in the range of 1 μm to 100 μm. If the average particle size of the filler (B) is too small, the fluidity of the composition will decrease, and if the average particle size is too large, the mixing device may be scraped.

[0064] The average particle size in this specification is a volume average particle size measured by a laser diffraction / scattering method. In applications requiring higher thermal conductivity, the particle size distribution of the filler (B) contained in the composition, as measured, for example, by a laser diffraction particle size analyzer, is preferably a bimodal distribution. Specifically, the particle size distribution preferably has peaks in the particle diameter range of 0.5 μm to less than 5 μm and in the particle diameter range of 5 μm to 60 μm.

[0065] A filler (B) having such a particle size distribution can be prepared, for example, by combining a filler (Ba) having an average particle size in the range of 0.5 μm or more but less than 5 μm with a filler (Bb) having an average particle size in the range of 5 μm or more but less than 60 μm. By combining two or more fillers (B) having different average particle sizes, a state of packing close to the closest packing can be achieved, resulting in higher thermal conductivity.

[0066] When the filler (B) has a bimodal particle size distribution, the proportion of filler (B) having a particle size of less than 5 μm in the entire filler (B) is preferably 10 to 50 mass %, and the proportion of filler (B) having a particle size of 5 μm or more is preferably 50 to 90 mass %.

[0067] When the filler (Ba) and the filler (Bb) are used in combination, the blending ratio (mass ratio) of the filler (Ba) is preferably 10 to 50 mass%, and the blending amount of the filler (Bb) is preferably 50 to 90 mass%, relative to 100 mass% of the total of the filler (Ba) and the filler (Bb).

[0068] When the compounding ratio of the filler (Ba) to the filler (Bb) is within the above range, the present composition can be easily obtained having flexibility suitable for producing a heat-dissipating sheet (not easily becoming hard and brittle). Furthermore, by using a spherical filler (B) in combination with a non-spherical filler (B) (for example, an amorphous filler (B)), it is possible to further improve thermal conductivity. Spherical aluminum oxide may be used as the filler (B). Examples of methods for producing spherical aluminum oxide include a high-temperature spraying method and a method of hydrothermal treatment of alumina hydrate.

[0069] <Graft-modified ethylene-α-olefin copolymer (C)> The graft-modified ethylene-α-olefin copolymer (C) satisfies the following requirements (c-1) to (c-6).

[0070] <Requirement (c-1)> The graft-modified ethylene-α-olefin copolymer (C) contains a main chain portion derived from the ethylene-α-olefin copolymer (C0).

[0071] Examples of the α-olefin include α-olefins other than ethylene. Examples of the α-olefin include linear α-olefins having 3 to 20 carbon atoms, such as propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, and 1-eicosene, as well as branched α-olefins having 3 to 20 carbon atoms, such as 3-methyl-1-pentene, 4-methyl-1-pentene, 8-methyl-1-nonene, 7-methyl-1-decene, 6-methyl-1-undecene, and 6,8-dimethyl-1-decene. The α-olefins may be one type or two or more types. As the α-olefin, from the viewpoints of effectively reducing the crystallinity of the ethylene-α-olefin copolymer (C0) to make it liquid, improving the flowability and flexibility, and improving the compatibility between the graft-modified ethylene-α-olefin copolymer (C) and the rubber component (A), an α-olefin having 3 to 10 carbon atoms is preferred, and propylene is more preferred.

[0072] <Requirement (c-2)> The graft-modified ethylene-α-olefin copolymer (C) contains a graft moiety derived from at least one unsaturated carboxylic acid monomer selected from the group consisting of unsaturated carboxylic acids having 3 to 10 carbon atoms and derivatives of the unsaturated carboxylic acids.

[0073] Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, and nadic acid. TM (endo-cis-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic acid).

[0074] Examples of the derivatives of unsaturated carboxylic acids include acid halide compounds, amide compounds, imide compounds, acid anhydrides, and ester compounds of the unsaturated carboxylic acids. The acid halide compound of the unsaturated carboxylic acid includes, for example, malenyl chloride.

[0075] Examples of the amide compound of the unsaturated carboxylic acid include (meth)acrylamide, maleic acid monoamide, maleic acid diamide, maleic acid-N-monoethylamide, maleic acid-N,N-diethylamide, maleic acid-N-monobutylamide, maleic acid-N,N-dibutylamide, fumaric acid monoamide, fumaric acid diamide, fumaric acid-N-monobutylamide, and fumaric acid-N,N-dibutylamide.

[0076] Examples of the imide compound of unsaturated carboxylic acid include maleimide, N-butylmaleimide, and N-phenylmaleimide. Examples of the acid anhydrides of unsaturated carboxylic acids include maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, and dimethyl tetrahydrophthalate.

[0077] Examples of the ester compound of the unsaturated carboxylic acid include methyl (meth)acrylate, ethyl (meth)acrylate, monomethyl maleate, dimethyl maleate, monoethyl maleate, diethyl maleate, monomethyl fumarate, dimethyl fumarate, diethyl fumarate, monomethyl itaconate, dimethyl itaconate, diethyl itaconate, diethyl citraconate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and glycidyl maleate.

[0078] The unsaturated carboxylic acid monomer is preferably an unsaturated dicarboxylic acid or an acid anhydride thereof, and more preferably maleic acid, nadic acid, or the like. TM and acid anhydrides thereof are more preferred. The unsaturated carboxylic acid monomers may be used alone or in combination of two or more.

[0079] The unsaturated carboxylic acid monomer may be derived from biomass or from fossil fuel, or both of the biomass-derived monomer and the fossil fuel-derived monomer may be used.

[0080] <Requirement (c-3)> The graft-modified ethylene-α-olefin copolymer (C) has an acid value of 10 to 150 mgKOH / g.

[0081] The acid value is preferably 15 to 120 mgKOH / g, and more preferably 20 to 100 mgKOH / g. The acid value is used as an indicator of the amount of grafting. When the acid value of the graft-modified ethylene-α-olefin copolymer (C) is within the above range, the interaction with the filler (B) is improved, the composition has excellent mix processability, and the resulting molded article is less sticky. Furthermore, when the acid value of the graft-modified ethylene-α-olefin copolymer (C) is within the above range, thermal conductivity is improved. For example, when a heat-dissipating sheet obtained from the composition is used in an electronic device, the electronic device is less likely to deteriorate due to heat and is less likely to malfunction even in high-temperature environments.

[0082] The acid value can be adjusted by the graft amount. For example, in order to increase the acid value of the graft-modified ethylene-α-olefin copolymer (C), it is preferable to increase the graft amount. The acid value indicates the number of milligrams of potassium hydroxide required to neutralize the acid contained in 1 g of the polymer, and can be measured by a method in accordance with JIS K2501:2003.

[0083] <Requirement (c-4)> The apparent viscosity (Brookfield viscosity) of the graft-modified ethylene-α-olefin copolymer (C) at 150°C is 20 to 1,500 mPa·s.

[0084] The apparent viscosity is preferably 40 to 1,200 mPa·s, and more preferably 50 to 1,000 mPa·s. When the apparent viscosity is within the above range, even if a molded article formed from this composition is heated to a high temperature, the outflow of the graft-modified ethylene-α-olefin copolymer (C) and a decrease in the thermal conductivity of the molded article can be prevented, and a molded article having flexibility suitable for the production of a heat-dissipating sheet can be obtained. The apparent viscosity can be measured by the method described in JIS K7117-1.

[0085] <Requirement (c-5)> The graft-modified ethylene-α-olefin copolymer (C) has a weight average molecular weight (Mw) of 1,500 to 25,000 as determined by GPC.

[0086] The Mw is preferably 2,000 to 22,000, and more preferably 3,000 to 20,000. When the Mw of the graft-modified ethylene-α-olefin copolymer (C) is within the above range, it has excellent compatibility and flowability with the rubber component (A), and a molded product having flexibility and thermal conductivity suitable for producing a heat-dissipating sheet can be easily obtained. Mw can be measured by GPC calibrated using a standard substance (monodisperse polystyrene) of known molecular weight, and specifically, it can be measured by the method described in the Examples section below.

[0087] <Requirement (c-6)> The melting point of the graft-modified ethylene-α-olefin copolymer (C) was not observed by differential scanning calorimetry (DSC).

[0088] Here, "no melting point is observed" means that the heat of fusion (ΔH) (unit: J / g) measured by DSC is not substantially measured. "No heat of fusion (ΔH) is substantially not measured" means that no peak is observed in DSC measurement, or the observed heat of fusion is 1 J / g or less.

[0089] It is preferable that the melting point of the graft-modified ethylene-α-olefin copolymer (C) is not observed, since this improves the compatibility with the rubber component (A) and improves the flowability and flexibility.

[0090] ·Method for producing ethylene-α-olefin copolymer (C0) Examples of methods for producing ethylene-α-olefin copolymers (C0) include copolymerizing ethylene with an α-olefin in the presence of a catalyst composed of a transition metal compound, such as vanadium, zirconium, titanium, or hafnium, and an organoaluminum compound (organoaluminum oxy-compound) and / or an ionizing ionic compound. Metallocene catalysts using transition metal compounds, such as zirconium, titanium, or hafnium, are preferred because they reduce the amount of 2,1-bonds (inversion) between two or more consecutive propylene monomers, thereby improving the low-temperature properties of the cured rubber composition. Such methods are described, for example, in International Publication No. 2000 / 34420, Japanese Patent Application Laid-Open No. 62-121710, International Publication No. 2004 / 29062, Japanese Patent Application Laid-Open No. 2004-175707, and International Publication No. 2001 / 27124.

[0091] Alternatively, the ethylene-α-olefin copolymer (C0) can be produced by copolymerizing ethylene and an α-olefin in the presence of an olefin polymerization catalyst containing a bridged metallocene compound (P) represented by general formula [I] and at least one compound (Q) selected from the group consisting of an organometallic compound (Q-1), an organoaluminum oxy compound (Q-2), and a compound (Q-3) that reacts with the bridged metallocene compound (P) to form an ion pair.

[0092] [Bridged Metallocene Compound (P)] The bridged metallocene compound (P) is represented by the formula [I].

[0093] [ka]

[0094] Y, M, and R in formula [I] 1 ~R 14 , Q and j are explained below. "Y" Y is a carbon atom or a silicon atom, preferably a carbon atom.

[0095] "M" M is a titanium atom, a zirconium atom or a hafnium atom, and is preferably a zirconium atom.

[0096] 《R 1 ~R 14 》 R 1 , R 2 , R 3 , R 4 , R 5 , R 8 , R 9 and R 12 are each independently a hydrogen atom, a hydrocarbon group, or a silicon-containing hydrocarbon group, and R 1 ~R 4 Two adjacent groups among these may be linked to each other to form a ring structure.

[0097] Examples of the hydrocarbon group include alkyl groups having 1 to 20 carbon atoms, cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, linear unsaturated hydrocarbon groups having 2 to 20 carbon atoms, cyclic unsaturated hydrocarbon groups having 3 to 20 carbon atoms, alkylene groups having 1 to 20 carbon atoms, and arylene groups having 6 to 20 carbon atoms.

[0098] Examples of the alkyl group having 1 to 20 carbon atoms include linear saturated hydrocarbon groups such as methyl, ethyl, n-propyl, allyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decanyl; and branched saturated hydrocarbon groups such as isopropyl, isobutyl, s-butyl, tert-butyl, tert-amyl, neopentyl, 3-methylpentyl, 1,1-diethylpropyl, 1,1-dimethylbutyl, 1-methyl-1-propylbutyl, 1,1-dipropylbutyl, 1,1-dimethyl-2-methylpropyl, 1-methyl-1-isopropyl-2-methylpropyl, and cyclopropylmethyl. The alkyl group preferably has 1 to 6 carbon atoms.

[0099] Examples of cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms include cyclic saturated hydrocarbon groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, norbornyl, 1-adamantyl, and 2-adamantyl; and groups in which at least one hydrogen atom of a cyclic saturated hydrocarbon group has been replaced with a hydrocarbon group having 1 to 17 carbon atoms, such as 3-methylcyclopentyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 4-cyclohexylcyclohexyl, and 4-phenylcyclohexyl. The number of carbon atoms in the cyclic saturated hydrocarbon group is preferably 5 to 11.

[0100] Examples of the chain unsaturated hydrocarbon group having 2 to 20 carbon atoms include alkenyl groups such as ethenyl group (vinyl group), 1-propenyl group, 2-propenyl group (allyl group), and 1-methylethenyl group (isopropenyl group); and alkynyl groups such as ethynyl group, 1-propynyl group, and 2-propynyl group (propargyl group). The number of carbon atoms in the chain unsaturated hydrocarbon group is preferably 2 to 4.

[0101] Examples of cyclic unsaturated hydrocarbon groups having 3 to 20 carbon atoms include cyclic unsaturated hydrocarbon groups such as cyclopentadienyl, norbornenyl, phenyl, naphthyl, indenyl, azulenyl, phenanthryl, and anthracenyl; cyclic unsaturated hydrocarbon groups in which at least one hydrogen atom has been replaced with a hydrocarbon group having 1 to 15 carbon atoms, such as 3-methylphenyl (m-tolyl), 4-methylphenyl (p-tolyl), 4-ethylphenyl, 4-tert-butylphenyl, 4-cyclohexylphenyl, biphenylyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, and 2,4,6-trimethylphenyl (mesityl); and linear or branched saturated hydrocarbon groups in which at least one hydrogen atom has been replaced with a cyclic saturated or unsaturated hydrocarbon group having 3 to 19 carbon atoms, such as benzyl and cumyl. The cyclic unsaturated hydrocarbon group preferably has 6 to 10 carbon atoms.

[0102] Examples of alkylene groups having 1 to 20 carbon atoms include methylene, ethylene, dimethylmethylene (isopropylidene), ethylmethylene, methylethylene, and n-propylene. The alkylene group preferably has 1 to 6 carbon atoms.

[0103] Examples of the arylene group having 6 to 20 carbon atoms include an o-phenylene group, an m-phenylene group, a p-phenylene group, and a 4,4'-biphenylylene group. The arylene group preferably has 6 to 12 carbon atoms.

[0104] Examples of silicon-containing hydrocarbon groups include alkylsilyl groups such as trimethylsilyl, triethylsilyl, tert-butyldimethylsilyl, and triisopropylsilyl, which are groups in which carbon atoms in the above-mentioned hydrocarbon groups are replaced with silicon atoms; arylsilyl groups such as dimethylphenylsilyl, methyldiphenylsilyl, and tert-butyldiphenylsilyl; pentamethyldisilanyl, and trimethylsilylmethyl. The alkylsilyl group preferably has 1 to 10 carbon atoms, and the arylsilyl group preferably has 6 to 18 carbon atoms.

[0105] In the present invention, R 2 and R 3 It is preferable that either one of R is a saturated hydrocarbon group having 4 carbon atoms. 1 ~R 4 All of the carbon atoms other than the saturated hydrocarbon group may be hydrogen atoms, or R 1 ~R 4 In the above, two groups adjacent to the saturated hydrocarbon group having 4 carbon atoms may be hydrogen atoms, and the group not adjacent to the saturated hydrocarbon group may be a methyl group. 2 and R 3 This does not preclude embodiments in which none of the above is a saturated hydrocarbon group having 4 carbon atoms, and for example, R 1 ~R 4 may all be hydrogen atoms.

[0106] R 6 and R 11 are the same group and are a hydrogen atom, a hydrocarbon group, or a silicon-containing hydrocarbon group, and the details of the hydrocarbon group and the silicon-containing hydrocarbon group are as described above. R 7 and R 10 are the same group and are a hydrogen atom, a hydrocarbon group, or a silicon-containing hydrocarbon group, and the details of the hydrocarbon group and the silicon-containing hydrocarbon group are as described above.

[0107] R 6 and R 7 may bond with a hydrocarbon having 2 to 3 carbon atoms to form a ring structure, and R 10 and R 11 may be bonded to a hydrocarbon having 2 to 3 carbon atoms to form a ring structure. R 6 , R 7 , R 10 and R 11 is not a hydrogen atom at the same time.

[0108] R 13 and R 14 are each independently a hydrogen atom, a hydrocarbon group, or a silicon-containing hydrocarbon group, and may be linked together to form a ring structure. The hydrocarbon group and silicon-containing hydrocarbon group are as described above in detail, and the hydrocarbon group further includes an aryl group and a substituted aryl group.

[0109] Examples of aryl groups include those exemplified above as cyclic unsaturated hydrocarbon groups having 3 to 20 carbon atoms, such as phenyl, 1-naphthyl, 2-naphthyl, anthracenyl, phenanthrenyl, tetracenyl, chrysenyl, pyrenyl, indenyl, azulenyl, pyrrolyl, pyridyl, furanyl, and thiophenyl, which are substituents derived from aromatic compounds. Preferred aryl groups are phenyl and 2-naphthyl.

[0110] Examples of the aromatic compounds include aromatic hydrocarbons and heterocyclic aromatic compounds such as benzene, naphthalene, anthracene, phenanthrene, tetracene, chrysene, pyrene, indene, azulene, pyrrole, pyridine, furan, and thiophene.

[0111] Examples of the substituted aryl group include, but are not limited to, the aryl group in which one or more hydrogen atoms have been substituted with at least one substituent selected from the group consisting of hydrocarbon groups having 1 to 20 carbon atoms, aryl groups, silicon-containing groups, nitrogen-containing groups, oxygen-containing groups, halogen atoms, and halogen-containing groups. Examples of substituted aryl groups include a 3-methylphenyl group (m-tolyl group), a 4-methylphenyl group (p-tolyl group), a 3-ethylphenyl group, a 4-ethylphenyl group, a 3,4-dimethylphenyl group, a 3,5-dimethylphenyl group, a biphenylyl group, a 4-(trimethylsilyl)phenyl group, a 4-aminophenyl group, a 4-(dimethylamino)phenyl group, a 4-(diethylamino)phenyl group, a 4-morpholinylphenyl group, a 4-methoxyphenyl group, a 4-ethoxyphenyl group, a 4-phenoxyphenyl group, a 3,4-dimethoxyphenyl group, a 3,5-dimethoxyphenyl group, a 3-methyl-4-methoxyphenyl group, a 3,5-dimethyl-4-methoxyphenyl group, a 3-(trifluoromethyl)phenyl group, a 4-(trifluoromethyl)phenyl group, a 3-chlorophenyl group, a 4-chlorophenyl group, a 3-fluorophenyl group, a 4-fluorophenyl group, a 5-methylnaphthyl group, and a 2-(6-methyl)pyridyl group.

[0112] In the present invention, R 13 and R 14 In one preferred embodiment of the present invention, either one or both of R 13 and R 14 Both of these are aryl groups. 13 and R 14 This does not preclude one of the groups from being a group other than an aryl group, for example, R 13is an aryl group, and R 14 may be an alkyl group having 1 to 20 carbon atoms.

[0113] j j is an integer of 1 to 4, and is preferably 2.

[0114] Q Q is a halogen atom, a hydrocarbon group, an anionic ligand, or a neutral ligand capable of coordinating to a lone electron pair, and when j is an integer of 2 or more, multiple Qs may be the same or different.

[0115] Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms, with chlorine being preferred. Details of the hydrocarbon group are as described above, and the hydrocarbon group preferably has 1 to 7 carbon atoms.

[0116] Anionic ligands include, for example, alkoxy groups such as methoxy and tert-butoxy groups; aryloxy groups such as phenoxy groups; carboxylate groups such as acetate and benzoate; and sulfonate groups such as mesylate and tosylate.

[0117] Examples of neutral ligands capable of coordinating with lone electron pairs include organic phosphorus compounds such as trimethylphosphine, triethylphosphine, triphenylphosphine, and diphenylmethylphosphine; and ether compounds such as tetrahydrofuran, diethyl ether, dioxane, and 1,2-dimethoxyethane.

[0118] (Examples of Bridged Metallocene Compounds (P)) The bridged metallocene compound (P) may be a compound represented by the formula [I], wherein R 13 and R 14 and a bridged metallocene compound (P1) in which either or both of the following are aryl groups.

[0119] Preferable examples of the bridged metallocene compound (P1) include those represented by the formula [I], in which R 13 and R 14 are both aryl groups, and R 2 and R 3 and R are each a saturated hydrocarbon group having 4 carbon atoms. 1 ~R 4 a bridged metallocene compound in which all atoms other than the saturated hydrocarbon group having 4 carbon atoms are hydrogen atoms, and R 1 ~R 4 Among these, a bridged metallocene compound in which two groups adjacent to the saturated hydrocarbon group having 4 carbon atoms are hydrogen atoms and the group not adjacent to the saturated hydrocarbon group having 4 carbon atoms is a methyl group can be mentioned.

[0120] The bridged metallocene compound (P1) may be R 13 and R 14 is an aryl group, and R 1 ~R 4 Also preferred is a bridged metallocene compound (P3) in which all of are hydrogen atoms.

[0121] Examples of the bridged metallocene compound (P) include: [Dimethylmethylene(η 5 -cyclopentadienyl)(η 5 -fluorenyl)]zirconium dichloride, [dimethylmethylene(η 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorenyl)]zirconium dichloride, [dimethylmethylene(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorenyl)]zirconium dichloride, [dimethylmethylene(η 5 -cyclopentadienyl)(η 5 -octamethyloctahydrodibenzofluorenyl)]zirconium dichloride, [dimethylmethylene(η 5 -cyclopentadienyl)(η 5-tetramethyloctahydrodibenzofluorenyl)]zirconium dichloride, [Cyclohexylidene(η 5 -cyclopentadienyl)(η 5 -fluorenyl)]zirconium dichloride, [cyclohexylidene(η 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorenyl)]zirconium dichloride, [cyclohexylidene(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorenyl)]zirconium dichloride, [cyclohexylidene(η 5 -cyclopentadienyl)(η 5 -octamethyloctahydrodibenzofluorenyl)]zirconium dichloride, [cyclohexylidene(η 5 -cyclopentadienyl)(η 5 -tetramethyloctahydrodibenzofluorenyl)]zirconium dichloride, [Diphenylmethylene (η 5 -cyclopentadienyl)(η 5 -fluorenyl)]zirconium dichloride, [diphenylmethylene(η 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorenyl)]zirconium dichloride, [diphenylmethylene(η 5 -2-methyl-4-tert-butylcyclopentadienyl)(η 5 -2,7-di-tert-butylfluorenyl)]zirconium dichloride, [diphenylmethylene(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorenyl)]zirconium dichloride, [diphenylmethylene(η 5 -cyclopentadienyl)(η 5 -octamethyloctahydrodibenzofluorenyl)]zirconium dichloride, [diphenylmethylene{η 5 -(2-methyl-4-i-propylcyclopentadienyl)}(η 5-octamethyloctahydrodibenzofluorenyl)]zirconium dichloride, [diphenylmethylene(η 5 -cyclopentadienyl)(η 5 -tetramethyloctahydrodibenzofluorenyl)]zirconium dichloride, [Methylphenylmethylene (η 5 -cyclopentadienyl)(η 5 -fluorenyl)]zirconium dichloride, [methylphenylmethylene(η 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorenyl)]zirconium dichloride, [methylphenylmethylene(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorenyl)]zirconium dichloride, [methylphenylmethylene(η 5 -cyclopentadienyl)(η 5 -octamethyloctahydrodibenzofluorenyl)]zirconium dichloride, [methylphenylmethylene(η 5 -cyclopentadienyl)(η 5 -tetramethyloctahydrodibenzofluorenyl)]zirconium dichloride, [Methyl(3-methylphenyl)methylene(η 5 -cyclopentadienyl)(η 5 -fluorenyl)]zirconium dichloride, [methyl(3-methylphenyl)methylene(η 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorenyl)]zirconium dichloride, [methyl(3-methylphenyl)methylene(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorenyl)]zirconium dichloride, [methyl(3-methylphenyl)methylene(η 5 -cyclopentadienyl)(η 5 -octamethyloctahydrodibenzofluorenyl)]zirconium dichloride, [methyl(3-methylphenyl)methylene(η 5-cyclopentadienyl)(η 5 -tetramethyloctahydrodibenzofluorenyl)]zirconium dichloride, [Methyl(4-methylphenyl)methylene(η 5 -cyclopentadienyl)(η 5 -fluorenyl)]zirconium dichloride, [methyl(4-methylphenyl)methylene(η 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorenyl)]zirconium dichloride, [methyl(4-methylphenyl)methylene(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorenyl)]zirconium dichloride, [methyl(4-methylphenyl)methylene(η 5 -cyclopentadienyl)(η 5 -octamethyloctahydrodibenzofluorenyl)]zirconium dichloride, [methyl(4-methylphenyl)methylene(η 5 -cyclopentadienyl)(η 5 -tetramethyloctahydrodibenzofluorenyl)]zirconium dichloride, [Diphenylsilylene(η 5 -cyclopentadienyl)(η 5 -fluorenyl)]zirconium dichloride, [diphenylsilylene(η 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorenyl)]zirconium dichloride, [diphenylsilylene(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorenyl)]zirconium dichloride, [diphenylsilylene(η 5 -cyclopentadienyl)(η 5 -octamethyloctahydrodibenzofluorenyl)]zirconium dichloride, [diphenylsilylene(η 5 -cyclopentadienyl)(η 5 -tetramethyloctahydrodibenzofluorenyl)]zirconium dichloride, [Bis(3-methylphenyl)silylene(η 5 -cyclopentadienyl)(η 5 -fluorenyl)]zirconium dichloride, [bis(3-methylphenyl)silylene(η 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorenyl)]zirconium dichloride, [bis(3-methylphenyl)silylene(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorenyl)]zirconium dichloride, [bis(3-methylphenyl)silylene(η 5 -cyclopentadienyl)(η 5 -octamethyloctahydrodibenzofluorenyl)]zirconium dichloride, [bis(3-methylphenyl)silylene(η 5 -cyclopentadienyl)(η 5 -tetramethyloctahydrodibenzofluorenyl)]zirconium dichloride, [Dicyclohexylsilylene(η 5 -cyclopentadienyl)(η 5 -fluorenyl)]zirconium dichloride, [dicyclohexylsilylene(η 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorenyl)]zirconium dichloride, [dicyclohexylsilylene(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorenyl)]zirconium dichloride, [dicyclohexylsilylene(η 5 -cyclopentadienyl)(η 5 -octamethyloctahydrodibenzofluorenyl)]zirconium dichloride, [dicyclohexylsilylene(η 5 -cyclopentadienyl)(η 5 -tetramethyloctahydrodibenzofluorenyl)]zirconium dichloride, [Ethylene (η 5 -cyclopentadienyl)(η 5-fluorenyl)]zirconium dichloride, [ethylene(η 5 -cyclopentadienyl)(η 5 -2,7-di-tert-butylfluorenyl)]zirconium dichloride, [ethylene(η 5 -cyclopentadienyl)(η 5 -3,6-di-tert-butylfluorenyl)]zirconium dichloride, [ethylene(η 5 -cyclopentadienyl)(η 5 -octamethyloctahydrodibenzofluorenyl)]zirconium dichloride, [ethylene(η 5 -cyclopentadienyl)(η 5 -tetramethyloctahydrodibenzofluorenyl)]zirconium dichloride, Ethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)](η 5 -fluorenyl)zirconium dichloride, ethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)][η 5 -(3,6-di-tert-butylfluorenyl)]zirconium dichloride, ethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)][η 5 -(2,7-di-tert-butylfluorenyl)]zirconium dichloride, ethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)](octamethyloctahydrodibenzfluorenyl)zirconium dichloride, ethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)](benzofluorenyl)zirconium dichloride, ethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)](dibenzofluorenyl)zirconium dichloride, ethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)](octahydrodibenzofluorenyl)zirconium dichloride, ethylene [η 5-(3-tert-butyl-5-methylcyclopentadienyl)][η 5 -(2,7-diphenyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride, ethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)][η 5 -(2,7-dimethyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride, Ethylene [η 5 -(3-tert-butylcyclopentadienyl)](η 5 -fluorenyl)zirconium dichloride, ethylene [η 5 -(3-tert-butylcyclopentadienyl)][η 5 -(3,6-di-tert-butylfluorenyl)]zirconium dichloride, ethylene [η 5 -(3-tert-butylcyclopentadienyl)][η 5 -(2,7-di-tert-butylfluorenyl)]zirconium dichloride, ethylene [η 5 -(3-tert-butylcyclopentadienyl)](octamethyloctahydrodibenzfluorenyl)zirconium dichloride, ethylene [η 5 -(3-tert-butylcyclopentadienyl)](benzofluorenyl)zirconium dichloride, ethylene [η 5 -(3-tert-butylcyclopentadienyl)](dibenzofluorenyl)zirconium dichloride, ethylene [η 5 -(3-tert-butylcyclopentadienyl)](octahydrodibenzofluorenyl)zirconium dichloride, ethylene [η 5 -(3-tert-butylcyclopentadienyl)][η 5 -(2,7-diphenyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride, ethylene [η 5 -(3-tert-butylcyclopentadienyl)][η 5 -(2,7-dimethyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride, Ethylene [η 5-(3-n-butylcyclopentadienyl)](η 5 -fluorenyl)zirconium dichloride, ethylene [η 5 -(3-n-butylcyclopentadienyl)][η 5 -(3,6-di-tert-butylfluorenyl)]zirconium dichloride, ethylene [η 5 -(3-n-butylcyclopentadienyl)][η 5 -(2,7-di-tert-butylfluorenyl)]zirconium dichloride, ethylene [η 5 -(3-n-butylcyclopentadienyl)](octamethyloctahydrodibenzfluorenyl)zirconium dichloride, ethylene [η 5 -(3-n-butylcyclopentadienyl)](benzofluorenyl)zirconium dichloride, ethylene [η 5 -(3-n-butylcyclopentadienyl)](dibenzofluorenyl)zirconium dichloride, ethylene [η 5 -(3-n-butylcyclopentadienyl)](octahydrodibenzofluorenyl)zirconium dichloride, ethylene [η 5 -(3-n-butylcyclopentadienyl)][η 5 -(2,7-diphenyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride, ethylene [η 5 -(3-n-butylcyclopentadienyl)][η 5 -(2,7-dimethyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride, Diphenylmethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)](η 5 -Fluorenyl)zirconium dichloride, diphenylmethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)][η 5 -(3,6-di-tert-butylfluorenyl)]zirconium dichloride, diphenylmethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)][η 5-(2,7-di-tert-butylfluorenyl)]zirconium dichloride, diphenylmethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)](octamethyloctahydrodibenzfluorenyl)zirconium dichloride, diphenylmethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)](benzofluorenyl)zirconium dichloride, diphenylmethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)](dibenzofluorenyl)zirconium dichloride, diphenylmethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)](octahydrodibenzofluorenyl)zirconium dichloride, diphenylmethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)][η 5 -(2,7-diphenyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride, diphenylmethylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)][η 5 -(2,7-dimethyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride, Diphenylmethylene [η 5 -(3-tert-butylcyclopentadienyl)](η 5 -Fluorenyl)zirconium dichloride, diphenylmethylene [η 5 -(3-tert-butylcyclopentadienyl)][η 5 -(3,6-di-tert-butylfluorenyl)]zirconium dichloride, diphenylmethylene [η 5 -(3-tert-butylcyclopentadienyl)][η 5 -(2,7-di-tert-butylfluorenyl)]zirconium dichloride, diphenylmethylene [η 5 -(3-tert-butylcyclopentadienyl)](octamethyloctahydrodibenzfluorenyl)zirconium dichloride, diphenylmethylene [η 5-(3-tert-butylcyclopentadienyl)](benzofluorenyl)zirconium dichloride, diphenylmethylene [η 5 -(3-tert-butylcyclopentadienyl)](dibenzofluorenyl)zirconium dichloride, diphenylmethylene [η 5 -(3-tert-butylcyclopentadienyl)](octahydrodibenzofluorenyl)zirconium dichloride, diphenylmethylene [η 5 -(3-tert-butylcyclopentadienyl)][η 5 -(2,7-diphenyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride, diphenylmethylene [η 5 -(3-tert-butylcyclopentadienyl)][η 5 -(2,7-dimethyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride, Diphenylmethylene [η 5 -(3-n-butylcyclopentadienyl)](η 5 -Fluorenyl)zirconium dichloride, diphenylmethylene [η 5 -(3-n-butylcyclopentadienyl)][η 5 -(3,6-di-tert-butylfluorenyl)]zirconium dichloride, diphenylmethylene [η 5 -(3-n-butylcyclopentadienyl)][η 5 -(2,7-di-tert-butylfluorenyl)]zirconium dichloride, diphenylmethylene [η 5 -(3-n-butylcyclopentadienyl)](octamethyloctahydrodibenzfluorenyl)zirconium dichloride, diphenylmethylene [η 5 -(3-n-butylcyclopentadienyl)](benzofluorenyl)zirconium dichloride, diphenylmethylene [η 5 -(3-n-butylcyclopentadienyl)](dibenzofluorenyl)zirconium dichloride, diphenylmethylene [η 5-(3-n-butylcyclopentadienyl)](octahydrodibenzofluorenyl)zirconium dichloride, diphenylmethylene [η 5 -(3-n-butylcyclopentadienyl)][η 5 -(2,7-diphenyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride, diphenylmethylene [η 5 -(3-n-butylcyclopentadienyl)][η 5 -(2,7-dimethyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride, Di(p-tolyl)methylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)](η 5 -fluorenyl)zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)][η 5 -(3,6-di-tert-butylfluorenyl)]zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)][η 5 -(2,7-di-tert-butylfluorenyl)]zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)](octamethyloctahydrodibenzfluorenyl)zirconium dichloride, di(p-tolyl)methylene[η 5 -(3-tert-butyl-5-methylcyclopentadienyl)](benzofluorenyl)zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)](dibenzofluorenyl)zirconium dichloride, di(p-tolyl)methylene[η 5 -(3-tert-butyl-5-methylcyclopentadienyl)](octahydrodibenzofluorenyl)zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)][η 5-(2,7-diphenyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-tert-butyl-5-methylcyclopentadienyl)][η 5 -(2,7-dimethyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride, Di(p-tolyl)methylene [η 5 -(3-tert-butylcyclopentadienyl)](η 5 -fluorenyl)zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-tert-butylcyclopentadienyl)][η 5 -(3,6-di-tert-butylfluorenyl)]zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-tert-butylcyclopentadienyl)][η 5 -(2,7-di-tert-butylfluorenyl)]zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-tert-butylcyclopentadienyl)](octamethyloctahydrodibenzfluorenyl)zirconium dichloride, di(p-tolyl)methylene[η 5 -(3-tert-butylcyclopentadienyl)](benzofluorenyl)zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-tert-butylcyclopentadienyl)](dibenzofluorenyl)zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-tert-butylcyclopentadienyl)](octahydrodibenzofluorenyl)zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-tert-butylcyclopentadienyl)][η 5 -(2,7-diphenyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-tert-butylcyclopentadienyl)][η 5-(2,7-dimethyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride, Di(p-tolyl)methylene [η 5 -(3-n-butylcyclopentadienyl)](η 5 -fluorenyl)zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-n-butylcyclopentadienyl)][η 5 -(3,6-di-tert-butylfluorenyl)]zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-n-butylcyclopentadienyl)][η 5 -(2,7-di-tert-butylfluorenyl)]zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-n-butylcyclopentadienyl)](octamethyloctahydrodibenzfluorenyl)zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-n-butylcyclopentadienyl)](benzofluorenyl)zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-n-butylcyclopentadienyl)](dibenzofluorenyl)zirconium dichloride, di(p-tolyl)methylene[η 5 -(3-n-butylcyclopentadienyl)](octahydrodibenzofluorenyl)zirconium dichloride, di(p-tolyl)methylene [η 5 -(3-n-butylcyclopentadienyl)](2,7-diphenyl-3,6-di-tert-butylfluorenyl)zirconium dichloride, di(p-tolyl)methylene[η 5 -(3-n-butylcyclopentadienyl)][η 5 -(2,7-dimethyl-3,6-di-tert-butylfluorenyl)]zirconium dichloride Examples include:

[0122] Further examples of the bridged metallocene compound (P) include compounds in which the zirconium atom of the above-mentioned compound is replaced with a hafnium atom or a titanium atom, and compounds in which the chloro ligand is replaced with a methyl group. 5 -Tetramethyloctahydrodibenzofluorenyl is 4,4,7,7-tetramethyl-(5a,5b,11a,12,12a-η 5 )-1,2,3,4,7,8,9,10-octahydrodibenzo[b,H]fluorenyl group, η 5 -Octamethyloctahydrodibenzofluorenyl is 1,1,4,4,7,7,10,10-octamethyl-(5a,5b,11a,12,12a-η 5 )-1,2,3,4,7,8,9,10-octahydrodibenzo[b,H]fluorenyl group, respectively. The bridged metallocene compounds (P) may be used singly or in combination of two or more.

[0123] [Compound (Q)] The compound (Q) is at least one compound selected from the group consisting of an organometallic compound (Q-1), an organoaluminum oxy compound (Q-2), and a compound (Q-3) that reacts with the bridged metallocene compound (P) to form an ion pair. Examples of the organometallic compound (Q-1) include the following organometallic compounds (Q-1a), (Q-1b), and (Q-1c) of Group 1, 2, 12, or 13 of the periodic table.

[0124] (Q-1a) General formula R a m Al(OR b ) n H p X q An organoaluminum compound represented by the formula: In the formula, R a and R bmay be the same as or different from each other, and is a hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms. X is a halogen atom, m is a number where 0 < m ≦ 3, n is a number where 0 ≦ n < 3, p is a number where 0 ≦ p < 3, q is a number where 0 ≦ q < 3, and m + n + p + q = 3.

[0125] Examples of such compounds include tri-n-alkylaluminums such as trimethylaluminum, triethylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, and tri-n-octylaluminum, tri-branched alkylaluminums such as triisopropylaluminum, triisobutylaluminum, tri-sec-butylaluminum, tri-tert-butylaluminum, tri-2-methylbutylaluminum, tri-3-methylhexylaluminum, and tri-2-ethylhexylaluminum, tricycloalkylaluminums such as tricyclohexylaluminum and tricyclooctylaluminum, triarylaluminums such as triphenylaluminum and tri(4-methylphenyl)aluminum, dialkylaluminum hydrides such as diisopropylaluminum hydride and diisobutylaluminum hydride, The general formula (i-C4H9) x [[ID=第十八条]]Al y (C5H 10 ) z (where x, y, and z are positive numbers and z ≦ 2x.) Alkenylaluminums such as isoprenylaluminum represented by the formula, alkylaluminum alkoxides such as isobutylaluminum methoxide and isobutylaluminum ethoxide, dialkylaluminum alkoxides such as dimethylaluminum methoxide, diethylaluminum ethoxide, and dibutylaluminum butoxide, alkylaluminum sesquialkoxides such as ethylaluminum sesquiethoxide and butylaluminum sesquibutoxide, General formula R a 2.5 Al(OR b ) 0.5 Partially alkoxylated alkylaluminum having an average composition represented by the following formula: alkylaluminum aryloxides such as diethylaluminum phenoxide and diethylaluminum (2,6-di-tert-butyl-4-methylphenoxide); dialkylaluminum halides such as dimethylaluminum chloride, diethylaluminum chloride, dibutylaluminum chloride, diethylaluminum bromide and diisobutylaluminum chloride; alkylaluminum sesquihalides such as ethylaluminum sesquichloride, butylaluminum sesquichloride and ethylaluminum sesquibromide; partially halogenated alkylaluminums, such as alkylaluminum dihalides, such as ethylaluminum dichloride; dialkylaluminum hydrides such as diethylaluminum hydride and dibutylaluminum hydride; alkylaluminum dihydrides such as ethylaluminum dihydride and propylaluminum dihydride and other partially hydrogenated alkylaluminums; Partially alkoxylated and halogenated alkylaluminums such as ethylaluminum ethoxychloride, butylaluminum butoxychloride and ethylaluminum ethoxybromide In addition, the general formula R a m Al(OR b ) n H p X q Compounds similar to the compound represented by the formula (1) can also be used. Examples of such compounds include organoaluminum compounds in which two or more aluminum compounds are bonded via nitrogen atoms. Examples of such organoaluminum compounds include (C2H5)2AlN(C2H5)Al(C2H5)2.

[0126] (Q-1b) General formula M 2 AlR a 4, a complex alkylation product of a metal from Group 1 of the periodic table with aluminum. In the formula, M 2 is Li, Na, or K, and R a is a hydrocarbon group having 1 to 15 carbon atoms. a is preferably a hydrocarbon group having 1 to 4 carbon atoms. Such compounds include, for example, LiAl(C2H5)4 and LiAl(C7H 15 )4 can be mentioned.

[0127] (Q-1c) General formula R a R b M 3 Dialkyl compounds of metals in Group 2 or 12 of the periodic table, represented by the formula: In the formula, R a and R b may be the same or different and are hydrocarbon groups having 1 to 15 carbon atoms, preferably 1 to 4 carbon atoms; M 3 is Mg, Zn or Cd. As the organoaluminum oxy compound (Q-2), a conventionally known aluminoxane can be used as it is. Specific examples of the organoaluminum oxy compound (Q-2) include compounds represented by the general formula [II] and compounds represented by the general formula [III].

[0128] [ka]

[0129] In the formulas [II] and [III], R is a hydrocarbon group having 1 to 10 carbon atoms, and n is an integer of 2 or more. Methylaluminoxanes in which R is a methyl group and n is 3 or greater, preferably 10 or greater, are preferred. There is no problem if these aluminoxanes contain a small amount of an organoaluminum compound.

[0130] When copolymerization of ethylene with an α-olefin having three or more carbon atoms is carried out at high temperatures, benzene-insoluble organoaluminum oxy compounds such as those exemplified in JP-A-2-78687 can also be used. Also suitable are the organoaluminum oxy compounds described in JP-A-2-167305, and aluminoxanes having two or more alkyl groups described in JP-A-2-24701 and JP-A-3-103407. A "benzene-insoluble organoaluminum oxy compound" refers to a compound that is insoluble or poorly soluble in benzene, with the Al component soluble in benzene at 60°C being preferably 10% or less, more preferably 5% or less, and even more preferably 2% or less, calculated as Al atoms.

[0131] The organoaluminum oxy compound (Q-2) also includes, for example, modified methylaluminoxane represented by the general formula [IV].

[0132] [ka]

[0133] In formula [IV], Rx is a hydrocarbon group having 1 to 10 carbon atoms, and m and n are each independently an integer of 2 or more. The modified methylaluminoxane represented by formula [IV] can be prepared using trimethylaluminum and alkylaluminums other than trimethylaluminum, for example, trimethylaluminum and triisobutylaluminum, as described in U.S. Pat. Nos. 4,960,878 and 5,041,584. Aluminoxanes in which Rx is an isobutyl group are commercially available in saturated hydrocarbon solutions under the trade names MMAO and TMAO (see Tosoh Finechem Corporation, Tosoh Research & Technology Review, Vol. 47, 55 (2003)).

[0134] The organoaluminum oxy compound (Q-2) also includes an organoaluminum oxy compound containing a boron atom, represented by the general formula [V].

[0135] [ka]

[0136] In formula [V], R c is a hydrocarbon group having 1 to 10 carbon atoms, and R d may be the same or different and are a hydrogen atom, a halogen atom or a hydrocarbon group having 1 to 10 carbon atoms. Examples of the compound (Q-3) that reacts with the bridged metallocene compound (P) to form an ion pair (hereinafter, sometimes abbreviated as "ionized ionic compound" or simply "ionic compound") include Lewis acids, ionic compounds, borane compounds, and carborane compounds described in, for example, JP-T-1-501950, JP-T-1-502036, JP-A-3-179005, JP-A-3-179006, JP-A-3-207703, JP-A-3-207704, and U.S. Pat. No. 5,321,106, and further include heteropoly compounds and isopoly compounds.

[0137] The ionized ionic compound may, for example, be a boron compound represented by the general formula [VI].

[0138] [ka]

[0139] In formula [VI], R e+ For example, H + , carbenium cations, oxonium cations, ammonium cations, phosphonium cations, cycloheptyltrienyl cations, and ferrocenium cations with transition metals. f ~R imay be the same or different and are substituents selected from the group consisting of hydrocarbon groups having 1 to 20 carbon atoms, silicon-containing groups, nitrogen-containing groups, oxygen-containing groups, halogen atoms and halogen-containing groups, and are preferably substituted aryl groups.

[0140] Examples of the carbenium cation include trisubstituted carbenium cations such as triphenylcarbenium cation, tris(4-methylphenyl)carbenium cation, and tris(3,5-dimethylphenyl)carbenium cation.

[0141] Examples of the ammonium cation include trialkyl-substituted ammonium cations such as trimethylammonium cation, triethylammonium cation, tri(n-propyl)ammonium cation, triisopropylammonium cation, tri(n-butyl)ammonium cation, and triisobutylammonium cation; N,N-dialkylanilinium cations such as N,N-dimethylanilinium cation, N,N-diethylanilinium cation, and N,N-2,4,6-pentamethylanilinium cation; and dialkylammonium cations such as diisopropylammonium cation and dicyclohexylammonium cation.

[0142] Examples of the phosphonium cation include triarylphosphonium cations such as triphenylphosphonium cation, tris(4-methylphenyl)phosphonium cation, and tris(3,5-dimethylphenyl)phosphonium cation.

[0143] R e+ Among the specific examples, carbenium cations and ammonium cations are preferred, and triphenylcarbenium cation, N,N-dimethylanilinium cation, and N,N-diethylanilinium cation are more preferred.

[0144] Among ionizable ionic compounds, examples of compounds containing a carbenium cation include triphenylcarbenium tetraphenylborate, triphenylcarbenium tetrakis(pentafluorophenyl)borate, triphenylcarbenium tetrakis{3,5-di-(trifluoromethyl)phenyl}borate, tris(4-methylphenyl)carbenium tetrakis(pentafluorophenyl)borate, and tris(3,5-dimethylphenyl)carbenium tetrakis(pentafluorophenyl)borate.

[0145] Among the ionizable ionic compounds, examples of compounds containing a trialkyl-substituted ammonium cation include triethylammonium tetraphenylborate, tripropylammonium tetraphenylborate, tri(n-butyl)ammonium tetraphenylborate, trimethylammonium tetrakis(4-methylphenyl)borate, trimethylammonium tetrakis(2-methylphenyl)borate, tri(n-butyl)ammonium tetrakis(pentafluorophenyl)borate, triethylammonium tetrakis(pentafluorophenyl)borate, tripropylammonium tetrakis(pentafluorophenyl)borate, tripropylammonium tetrakis(2,4-dimethylphenyl)borate, tri(n-butyl)ammonium tetrakis(3,5-dimethylphenyl)borate, tri(n-butyl)ammonium tetrakis{4-(trifluoromethyl)phenyl}borate, tri(n- butyl)ammonium tetrakis{3,5-di(trifluoromethyl)phenyl}borate, tri(n-butyl)ammonium tetrakis(2-methylphenyl)borate, dioctadecylmethylammonium tetraphenylborate, dioctadecylmethylammonium tetrakis(4-methylphenyl)borate, dioctadecylmethylammonium tetrakis(4-methylphenyl)borate, dioctadecylmethylammonium tetrakis(pentafluorophenyl)borate, dioctadecylmethylammonium tetrakis(2,4-dimethylphenyl)borate, dioctadecylmethylammonium tetrakis(3,5-dimethylphenyl)borate, dioctadecylmethylammonium tetrakis{4-(trifluoromethyl)phenyl}borate, dioctadecylmethylammonium tetrakis{3,5-di(trifluoromethyl)phenyl}borate, and dioctadecylmethylammonium.

[0146] Among the ionizable ionic compounds, examples of compounds containing an N,N-dialkylanilinium cation include N,N-dimethylanilinium tetraphenylborate, N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate, N,N-dimethylanilinium tetrakis{3,5-di(trifluoromethyl)phenyl}borate, N,N-diethylanilinium tetraphenylborate, N,N-diethylanilinium tetrakis(pentafluorophenyl)borate, N,N-diethylanilinium tetrakis{3,5-di(trifluoromethyl)phenyl}borate, N,N-2,4,6-pentamethylanilinium tetraphenylborate, and N,N-2,4,6-pentamethylanilinium tetrakis(pentafluorophenyl)borate.

[0147] Among the ionizing ionic compounds, examples of compounds containing a dialkylammonium cation include di-n-propylammonium tetrakis(pentafluorophenyl)borate and dicyclohexylammonium tetraphenylborate.

[0148] In addition, the ionic compounds exemplified in JP-A-2004-51676 can also be used without any restrictions. The ionic compound (Q-3) may be used alone or in combination of two or more.

[0149] Examples of the catalyst system include the following [1] to [4]. [1] The compound includes a bridged metallocene compound (P) and a compound (Q-2). [2] Includes the bridged metallocene compound (P), the compound (Q-1) and the compound (Q-2). [3] Includes the bridged metallocene compound (P), the compound (Q-1) and the compound (Q-3). [4] Includes the bridged metallocene compound (P), the compound (Q-2) and the compound (Q-3). The bridged metallocene compound (P) and the compounds (Q-1) to (Q-3) may be introduced into the reaction system in any order.

[0150] [Carrier (R)] The olefin polymerization catalyst containing the bridged metallocene compound (P) and the compound (Q) may further contain a support (R).

[0151] The carrier (R) is an inorganic or organic compound, and is a granular or particulate solid. Among these, preferred inorganic compounds are porous oxides, inorganic chlorides, clays, clay minerals, and ion-exchange layered compounds.

[0152] Examples of porous oxides include SiO2, Al2O3, MgO, ZrO, TiO2, B2O3, CaO, ZnO, BaO, ThO2, and composites or mixtures containing these. Examples of the composites or mixtures include natural or synthetic zeolites, SiO2-MgO, SiO2-Al2O3, SiO2-TiO2, SiO2-V2O5, SiO2-Cr2O3, and SiO2-TiO2-MgO. Among these, those containing SiO2 and / or Al2O3 as the main component are preferred. The particle size of the support (R) is preferably 0.5 to 300 μm, more preferably 1.0 to 200 μm. The specific surface area of ​​the support (R) is preferably 50 to 1,000 m 2 / g, more preferably 100 to 700m 2 The pore volume of the carrier (R) is preferably in the range of 0.3 to 3.0 cm 3 / g range. Such a support (R) is calcined at 100 to 1000°C, preferably 150 to 700°C, as required, before use.

[0153] Examples of inorganic chlorides include MgCl, MgBr, MnCl, and MnBr. The inorganic chlorides may be used as they are, or may be ground using a ball mill or a vibration mill. Alternatively, the inorganic chlorides may be dissolved in a solvent such as alcohol and then precipitated into fine particles using a precipitating agent.

[0154] Clay is usually composed mainly of clay minerals. Ion-exchangeable layered compounds are compounds with a crystalline structure in which constituent planes are stacked parallel to each other with weak bonding forces due to ionic bonds or the like, and the ions contained therein are exchangeable. Most clay minerals are ion-exchangeable layered compounds. These clays, clay minerals, and ion-exchangeable layered compounds are not limited to natural products, and artificial synthetic products can also be used.

[0155] Examples of ion-exchangeable layered compounds include ionic crystalline compounds having layered crystal structures such as hexagonal close packing type, antimony type, CdCl2 type, and CdI2 type.

[0156] Examples of clays and clay minerals include kaolin, bentonite, kibushi clay, gairome clay, allophane, hisingerite, pyrophyllite, ummo group, montmorillonite group, vermiculite, ryokudeite group, palygorskite, kaolinite, nacrite, dickite, and halloysite.

[0157] Examples of ion-exchangeable layered compounds include crystalline acid salts of polyvalent metals such as α-Zr(HAsO4)2·H2O, α-Zr(HPO4)2, α-Zr(KPO4)2·3H2O, α-Ti(HPO4)2, α-Ti(HAsO4)2·H2O, α-Sn(HPO4)2·H2O, γ-Zr(HPO4)2, γ-Ti(HPO4)2, and γ-Ti(NH4PO4)2·H2O.

[0158] It is also preferable to subject clay and clay minerals to chemical treatment. Examples of chemical treatment include surface treatment to remove impurities attached to the surface and treatment to affect the crystalline structure of the clay. Examples of chemical treatment include acid treatment, alkali treatment, salt treatment, and organic treatment.

[0159] Ion-exchangeable layered compounds may be layered compounds in which the interlayer spacing is expanded by utilizing the ion exchange property and replacing the exchangeable ions between the layers with other large, bulky ions. Such bulky ions act as supports supporting the layered structure and are usually called pillars. The introduction of another substance (guest compound) between the layers of a layered compound is called intercalation. Examples of guest compounds include cationic inorganic compounds such as TiCl4 and ZrCl4; metal alkoxides (R is a hydrocarbon group, etc.) such as Ti(OR)4, Zr(OR)4, PO(OR)3, and B(OR)3; [Al 13 O4(OH) 24 ]7 + , [Zr4(OH) 14 ]2 + , [Fe3O(OCOCH3)6] + Examples of suitable pillars include metal hydroxide ions such as those mentioned above. These compounds may be used singly or in combination of two or more. When intercalating these compounds, polymers obtained by hydrolysis and polycondensation of metal alkoxides (R is a hydrocarbon group, for example) such as Si(OR)4, Al(OR)3, and Ge(OR)4, and colloidal inorganic compounds such as SiO2, may also be present. Examples of suitable pillars include oxides produced by intercalating the metal hydroxide ions between layers and then dehydrating them with heat.

[0160] Of these, clay and clay minerals are preferred, and montmorillonite, vermiculite, pectolite, taeniolite and synthetic mica are particularly preferred. Examples of organic compounds usable as the carrier (R) include granular or particulate solids with particle sizes ranging from 0.5 to 300 μm. Specific examples include (co)polymers primarily composed of α-olefins having 2 to 14 carbon atoms, such as ethylene, propylene, 1-butene, and 4-methyl-1-pentene, or (co)polymers primarily composed of vinylcyclohexane and styrene, as well as modified products thereof.

[0161] The method of use and order of addition of each component of the polymerization catalyst may be selected arbitrarily, and at least two or more of the components in the catalyst may be contacted in advance. The bridged metallocene compound (P) (hereinafter also referred to as "component (P)") is preferably used in an amount of 1×10 per liter of reaction volume. -9 ~1×10 -1 moles, more preferably 1 x 10 -8 ~1×10 -2 It is used in molar amounts.

[0162] The organometallic compound (Q-1) (hereinafter also referred to as "component (Q-1)") is used in an amount such that the molar ratio of component (Q-1) to the transition metal atom (M) in component (P) [(Q-1) / M] is preferably 0.01 to 50,000, more preferably 0.05 to 10,000.

[0163] The organoaluminum oxy compound (Q-2) (hereinafter also referred to as "component (Q-2)") is used in an amount such that the molar ratio [(Q-2) / M] of aluminum atoms in component (Q-2) to transition metal atoms (M) in component (P) is preferably 10 to 5,000, more preferably 20 to 2,000.

[0164] The ionic compound (Q-3) (hereinafter also referred to as "component (Q-3)") is used in an amount such that the molar ratio of component (Q-3) to the transition metal atom (M) in component (P) [(Q-3) / M] is preferably 1 to 10,000, more preferably 1 to 5,000.

[0165] The polymerization temperature is preferably -50°C to 300°C, more preferably 30 to 250°C, even more preferably 100°C to 250°C, and particularly preferably 130°C to 200°C. Within this polymerization temperature range, as the temperature increases, the solution viscosity during polymerization decreases and the heat of polymerization is easily removed. The polymerization pressure is preferably atmospheric pressure to 10 MPa gauge pressure (MPaG), more preferably atmospheric pressure to 8 MPaG.

[0166] The polymerization reaction can be carried out in any of batch, semi-continuous and continuous modes. Furthermore, the polymerization can be carried out continuously in two or more polymerization vessels with different reaction conditions.

[0167] The molecular weight of the resulting copolymer can be adjusted by changing the hydrogen concentration in the polymerization system and / or the polymerization temperature, and can also be adjusted by the amount of compound (Q) used. When hydrogen is added, the amount is preferably about 0.001 to 5,000 nL per kg of the resulting copolymer.

[0168] The polymerization solvent used in the liquid-phase polymerization method is preferably an inert hydrocarbon solvent, more preferably a saturated hydrocarbon having a boiling point of 50°C to 200°C under normal pressure. Examples of polymerization solvents include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; and alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane. Hexane, heptane, octane, decane, and cyclohexane are particularly preferred. The α-olefin itself to be polymerized can also be used as the polymerization solvent. Aromatic hydrocarbons such as benzene, toluene, and xylene, as well as halogenated hydrocarbons such as ethylene chloride, chlorobenzene, and dichloromethane, can also be used as polymerization solvents; however, their use may be undesirable from the viewpoints of reducing the burden on the environment and minimizing the impact on human health.

[0169] [Vanadium-based catalyst] The ethylene-α-olefin copolymer (C0) can also be produced by copolymerizing ethylene with an α-olefin having 3 to 20 carbon atoms in the presence of a vanadium catalyst comprising a soluble vanadium compound (V) and an organoaluminum compound (Q').

[0170] Specifically, the soluble vanadium compound (V) is a compound represented by the following general formula: VO(OR) a X bor V(OR) c X d In the formula, R is a hydrocarbon group such as an alkyl group, a cycloalkyl group, and an aryl group, X is a halogen atom, and a, b, c, and d satisfy 0≦a≦3, 0≦b≦3, 2≦a + b≦3, 0≦c≦4, 0≦d≦4, and 3≦c + d≦4, respectively. It is preferable that a satisfies 1 < a≦3, c preferably satisfies 1 < c≦3, and d preferably satisfies 0≦d < 4.

[0171] Examples of the soluble vanadium compound (V) include VOCl3, VO(OCH3)Cl2, VO(OC2H5)Cl2, VO(OC2H5) 1.5 Cl 1.5 , VO(OC2H5)2Cl, VO(O-n-C3H7)Cl2, VO(O-iso-C3H7)Cl2, VO(O-n-C4H9)Cl2, VO(O-iso-C4H9)Cl2, VO(O-sec-C4H9)Cl2, VO(O-tert-C4H9)Cl2, VO(OC2H 5)3 , VOBr2, VCl4, VOCl2, VO(O-n-C4H9)3, VOCl3·2OC8H 17 OH and the like.

[0172] The organoaluminum compound (Q’) is the same as the organoaluminum compound (Q-1a), and the exemplified compounds thereof are also the same as the compounds exemplified for the organoaluminum compound (Q-1a). The organoaluminum compound (Q’) may be, for example, ethylaluminum sesquichloride.

[0173] The usage and addition order of the soluble vanadium compound (V) and the organoaluminum compound (Q’) are arbitrarily selected. The soluble vanadium compound (V) is preferably 1×10 -5 ~5×10 -3 mol, more preferably 5×10 -5 ~3×10 -3 mol per liter of the reaction volume.

[0174] The organoaluminum compound (Q') is used in an amount such that the molar ratio [(Q') / M] of the organoaluminum compound (Q') to the vanadium atoms (M) in the soluble vanadium compound (V) is preferably 2 to 50, more preferably 3 to 20.

[0175] When the ethylene-α-olefin copolymer (C0) is produced using the vanadium catalyst, the polymerization temperature is preferably −50° C. to 100° C., more preferably −30° C. to 80° C., and even more preferably −20° C. to 60° C. The polymerization pressure is preferably atmospheric pressure to 5 MPa gauge pressure (MPa-G), more preferably atmospheric pressure to 2 MPa-G. The polymerization reaction can be carried out by any of batch, semi-continuous, and continuous methods. Furthermore, the polymerization can also be carried out continuously in two or more polymerization reactors with different reaction conditions.

[0176] The molecular weight of the resulting ethylene-α-olefin copolymer (C0) can be adjusted by changing the hydrogen concentration in the polymerization system and the polymerization temperature, and also by the amount of organoaluminum compound (Q') used.

[0177] The polymerization solvent used in the liquid phase polymerization method is preferably an inert hydrocarbon solvent, more preferably a saturated hydrocarbon having a boiling point of 50°C to 200°C under normal pressure. Examples of the polymerization solvent include aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, and kerosene; and alicyclic hydrocarbons such as cyclopentane, cyclohexane, and methylcyclopentane, with hexane, heptane, octane, decane, and cyclohexane being particularly preferred. The α-olefin itself to be polymerized can also be used as the polymerization solvent.

[0178] The ethylene and α-olefins used as raw materials for the ethylene-α-olefin copolymer (C0) may be, for example, fossil fuel-derived monomers or biomass-derived monomers, and these monomers may be used alone or in combination of two or more. That is, the ethylene-α-olefin copolymer may be composed solely of fossil fuel-derived monomers, or may be composed solely of biomass-derived monomers, or may use a combination of fossil fuel-derived monomers and biomass-derived monomers.

[0179] Fossil fuels are oil, coal, natural gas, shale gas, or combinations thereof. Biomass is any renewable natural raw material and its residues, such as from plants or animals, including fungi, yeast, algae, and bacteria.

[0180] ·Method for producing graft-modified ethylene-α-olefin copolymer (C) The graft-modified ethylene-α-olefin copolymer (C) can be prepared by various conventionally known methods, for example, by adding at least one unsaturated carboxylic acid monomer selected from the group consisting of the unsaturated carboxylic acids having 3 to 10 carbon atoms and derivatives of the unsaturated carboxylic acids to the ethylene-α-olefin copolymer (C0) to graft-modify it. Examples of methods for producing the graft-modified ethylene-α-olefin copolymer (C) include the following method (α).

[0181] Method (α): a step (S1) of obtaining an ethylene-α-olefin copolymer (C0) by copolymerizing ethylene and an α-olefin in the presence of an olefin polymerization catalyst containing a bridged metallocene compound (P) represented by the following formula [I] and at least one compound (Q) selected from the group consisting of an organometallic compound (Q-1), an organoaluminum oxy compound (Q-2), and a compound (Q-3) that reacts with the bridged metallocene compound (P) to form an ion pair; and (S2) adding the unsaturated carboxylic acid monomer to the ethylene-α-olefin copolymer (C0) to graft-modify the ethylene-α-olefin copolymer (C0).

[0182] [ka]

[0183] Y, M, and R in formula [I] 1 ~R 14 , Q and j are the same as Y, M, R described above in the section "Production method of ethylene-α-olefin copolymer (C0)". 1 ~R 14 , Q, and j are the same as those described above in the section "Method for producing ethylene-α-olefin copolymer (C0)." The organometallic compound (Q-1), organoaluminum oxy compound (Q-2), and compound (Q-3) are the same as those described above in the section "Method for producing ethylene-α-olefin copolymer (C0)."

[0184] The graft modification of the ethylene-α-olefin copolymer (C0) with the unsaturated carboxylic acid monomer can be carried out, for example, by the following method (1) or (2).

[0185] (1) A method in which the ethylene-α-olefin copolymer (C0) is mixed in an extruder, a batch reactor, or the like, and the unsaturated carboxylic acid monomer is added thereto to effect graft modification. (2) A method in which the ethylene-α-olefin copolymer (C0) is dissolved in a solvent, and the unsaturated carboxylic acid monomer is added to the solution to effect graft modification. In either method, in order to efficiently graft-modify the ethylene-α-olefin copolymer (C0) with the unsaturated carboxylic acid monomer, it is preferable to carry out the graft-modification in the presence of a radical initiator, such as an organic peroxide or an azo compound.

[0186] Examples of the organic peroxides include benzoyl peroxide, dichlorobenzoyl peroxide, and dicumyl peroxide. Examples of the azo compounds include azobisisobutylnitrile and dimethylazoisobutyrate.

[0187] As such a radical initiator, for example, dialkyl peroxides such as dicumyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 1,4-bis(tert-butylperoxyisopropyl)benzene are preferably used.

[0188] These radical initiators are used in an amount of preferably 0.001 to 1 part by mass, more preferably 0.003 to 0.5 parts by mass, and even more preferably 0.05 to 0.3 parts by mass, per 100 parts by mass of the ethylene-α-olefin copolymer (C0).

[0189] The reaction temperature in the graft modification using a radical initiator as described above or in the graft modification performed without using a radical initiator is preferably set in the range of 60 to 350°C, more preferably 120 to 300°C.

[0190] <Content of each component> In the present composition, it is preferable that the content of the filler (B) is 100 to 2000 parts by mass and the content of the graft-modified ethylene-α-olefin copolymer (C) is 1 to 150 parts by mass relative to 100 parts by mass of the rubber component (A).

[0191] The filler (B) may be blended in an amount necessary for a molded article obtained from the composition to have thermal conductivity suitable for producing a heat-dissipating sheet (for example, 1.0 W / m K or more). For example, the content of the filler (B) per 100 parts by mass of the rubber component (A) is preferably 100 to 2,000 parts by mass, more preferably 200 to 1,700 parts by mass, and even more preferably 300 to 1,500 parts by mass.

[0192] If the content of filler (B) is within the above range, the molded article will have thermal conductivity and flexibility suitable for producing a heat-dissipating sheet, and the composition will have excellent mixing processability and a specific gravity that is not too high, making it more suitable as a rubber composition that requires high thermal conductivity and lightweight. If the content of filler (B) is too low, it will be difficult to sufficiently increase the thermal conductivity of the resulting molded article, while if the content of filler (B) is too high, problems such as a decrease in the flexibility of the molded article may occur.

[0193] The graft-modified ethylene-α-olefin copolymer (C) may be blended in an amount necessary for a molded article obtained from the composition to have flexibility suitable for producing a heat-dissipating sheet (for example, a Shore A hardness of less than 98 3 seconds after the start of indenter contact), and the amount of the graft-modified ethylene-α-olefin copolymer (C) per 100 parts by mass of the rubber component (A) is preferably 1 to 150 parts by mass, more preferably 5 to 120 parts by mass, and even more preferably 10 to 100 parts by mass.

[0194] Within the above ranges, the molded article has flexibility and thermal conductivity suitable for the production of heat-dissipating sheets, and the composition has excellent mixing processability and a specific gravity that is not too high, making it more suitable as a rubber composition for which high thermal conductivity and lightweight construction are required. If the content of the graft-modified ethylene-α-olefin copolymer (C) is too low, it becomes difficult to sufficiently enhance the flexibility of the resulting molded article, while if the content of the graft-modified ethylene-α-olefin copolymer (C) is too high, the graft-modified ethylene-α-olefin copolymer (C) may flow out of the molded article, resulting in problems such as reduced thermal conductivity.

[0195] <Other ingredients> The composition may contain components other than the rubber component (A), filler (B), and graft-modified ethylene-α-olefin copolymer (C) (hereinafter also referred to as "other components"). Examples of other components include crosslinking agents, crosslinking aids, softeners, plasticizers, flame retardants other than the filler (B), tackifiers, colorants, foaming agents, foaming aids, lubricants, activators, reaction inhibitors, dispersants, UV absorbers, heat stabilizers, antioxidants, and antioxidants. The number of such other components may be one or more.

[0196] Examples of crosslinking agents include organic peroxides; sulfur such as powdered sulfur, precipitated sulfur, colloidal sulfur, surface-treated sulfur, and insoluble sulfur; sulfur compounds such as sulfur monochloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide, and selenium dimethyldithiocarbamate; and metal compounds such as magnesium oxide, zinc oxide, and red lead.

[0197] Examples of organic peroxides include dicumyl peroxide, di-tert-butyl peroxide, di-tert-butylperoxy-3,3,5-trimethylcyclohexane, tert-butylcumyl peroxide, di-tert-amyl peroxide, tert-butyl hydroperoxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2,5-mono(tert-butylperoxy)hexane, and and α,α'-bis(tert-butylperoxy-m-isopropyl)benzene; peroxyesters such as tert-butyl peroxyacetate, tert-butyl peroxyisobutyrate, tert-butyl peroxypivalate, tert-butyl peroxymaleate, tert-butyl peroxyneodecanoate, tert-butyl peroxybenzoate, and di-tert-butyl peroxyphthalate; and ketone peroxides such as dicyclohexanone peroxide.

[0198] Although the organic peroxide can be used as it is, due to handling issues, it is preferable to use a diluted product in which the organic peroxide is adsorbed on an inorganic filler such as calcium carbonate, or a masterbatch-type diluted product intended to suppress powdering during mixing and improve dispersibility in the polymer. The concentration of the organic peroxide in the diluted product is preferably 10 to 60% by mass, more preferably 20 to 50% by mass.

[0199] When the composition contains an organic peroxide, the content of the organic peroxide is preferably 0.05 to 15 parts by mass, more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the rubber component (A).

[0200] When the composition contains sulfur or a sulfur compound, the content of sulfur or a sulfur compound is preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the rubber component (A).

[0201] When an organic peroxide is used as the crosslinking agent, examples of the crosslinking aid include sulfur, sulfur compounds such as dipentamethylenethiuram tetrasulfide, quinone dioxime compounds such as p-quinone dioxime and p,p'-dibenzoylquinone oxime, and polyfunctional monomers. Examples of the polyfunctional monomer include (meth)acrylate compounds such as polyethylene glycol di(meth)acrylate, allyl compounds such as diallyl phthalate and triallyl cyanurate, maleimide compounds such as metaphenylene bismaleimide and toluylene bismaleimide, and divinylbenzene.

[0202] When sulfur or a sulfur compound is used as the crosslinking agent, examples of the crosslinking aid include sulfenamide compounds such as N-cyclohexyl-2-benzothiazole sulfenamide, N-oxydiethylene-2-benzothiazole sulfenamide, N-tert-butyl-2-benzothiazole sulfenamide, and N,N-diisopropyl-2-benzothiazole sulfenamide; 2-mercaptobenzothiazole, 2-(2,4-dinitrophenyl)mercaptobenzothiazole, 2-(4-mercaptobenzothiazole), 2-(2,4-dinitrophenyl)mercaptobenzothiazole, and 2-(4-mercaptobenzothiazole). Thiazole compounds such as 2-(2,6-diethyl-4-morpholinodithio)benzothiazole, 2-(2,6-diethyl-4-morpholinothio)benzothiazole, and dibenzothiazyl disulfide; guanidine compounds such as diphenylguanidine, triphenylguanidine, diorthotolylguanidine, orthotolylbiguanide, and diphenylguanidine phthalate; aldehyde amines such as acetaldehyde-aniline condensation product, butyraldehyde-aniline condensation product, hexamethylenetetramine, and acetaldehyde ammonia. amine or aldehyde-ammonia compounds; imidazoline compounds such as 2-mercaptoimidazoline; thiourea compounds such as thiocarbanilide, diethylthiourea, dibutylthiourea, trimethylthiourea, and diorthotolylthiourea; tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, tetrakis(2-ethylhexyl)thiuram disulfide, and dipentamethylenethiuram tetrasulfide. dithiocarbamates such as zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc di-n-butyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, selenium dimethyldithiocarbamate, and tellurium dimethyldithiocarbamate; xanthates such as zinc dibutylxanthogenate; zinc oxide (zinc oxide); and fatty acids such as stearic acid.

[0203] When the composition contains a crosslinking aid, the content of the crosslinking aid is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 10 parts by mass, per 100 parts by mass of the rubber component (A).

[0204] Although the graft-modified ethylene-α-olefin copolymer (C) can function as a softener, softeners other than the graft-modified ethylene-α-olefin copolymer (C) may also be used. Examples of such softeners include petroleum-based softeners such as mineral oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt, and Vaseline; coal tar-based softeners such as coal tar and coal tar pitch; fatty oil-based softeners such as castor oil, linseed oil, rapeseed oil, soybean oil, and coconut oil; tall oil; sap; waxes such as beeswax, carnauba wax, and lanolin; fatty acids and their salts such as ricinoleic acid, palmitic acid, stearic acid, barium stearate, calcium stearate, and zinc laurate; and synthetic polymers such as petroleum resin, atactic polypropylene, and coumarone-indene resin. Among these, petroleum-based softeners are preferred, with mineral oil being more preferred.

[0205] When the present composition contains a softener other than the graft-modified ethylene-α-olefin copolymer (C), the content of the softener is preferably 1 to 100 parts by mass, more preferably 2 to 80 parts by mass, per 100 parts by mass of the rubber component (A).

[0206] Examples of the plasticizer include phthalate ester, adipate ester, sebacate ester, and phosphate plasticizers. Examples of tackifiers include coumarone-indene resins, terpene-phenol resins, and xylene-formaldehyde resins.

[0207] Colorants include, for example, inorganic pigments and organic pigments. Examples of foaming agents include sodium bicarbonate, ammonium carbonate, N,N'-dinitrosopentamethylenetetramine, azocarbonamide, azobisisobutyronitrile, benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, calcium amide, and paratoluenesulfonyl azide.

[0208] Foaming aids include, for example, salicylic acid, phthalic acid, and urea. Examples of the lubricant include polyethylene wax and polypropylene wax.

[0209] Commercially available polyethylene waxes include, for example, "Hiwax" and "Excellex" manufactured by Mitsui Chemicals, Inc., "Sunwax" manufactured by Sanyo Chemical Industries, Ltd., "Ceridust," "Licowax," and "Licocene" manufactured by Clariant, and "AC" manufactured by Honeywell.

[0210] Commercially available polypropylene waxes include, for example, "Hiwax" manufactured by Mitsui Chemicals, Inc., "Viscol" manufactured by Sanyo Chemical Industries, Ltd., "Ceridust," "Licowax," and "Licocene" manufactured by Clariant, and "AC" manufactured by Honeywell.

[0211] Examples of the flame retardant other than the filler (B) include inorganic flame retardants having a thermal conductivity of less than 10 W / m·K. Examples of the inorganic flame retardant include metal hydroxides having a thermal conductivity of less than 10 W / m·K. The flame retardant may be of one type or of two or more types. The shape of the flame retardant is not particularly limited, and examples include spherical, cubic, plate-like, columnar, and hexagonal plate-like shapes, with spherical shapes being preferred.

[0212] <Crosslinked body> The crosslinked product of the present invention is obtained by crosslinking the composition. Crosslinking the composition makes it difficult for components in the composition to leak out, and makes it easy to obtain a crosslinked product with heat resistance and thermal conductivity suitable for producing a heat-dissipating sheet.

[0213] The crosslinking may be carried out by chemical crosslinking using a crosslinking agent by heating or the like, or by radiation crosslinking by irradiating with radiation such as electron beams, X-rays, γ-rays, α-rays, and β-rays, etc. Alternatively, both chemical crosslinking and radiation crosslinking may be carried out.

[0214] When carrying out the chemical crosslinking, it is preferable to use a crosslinking agent (use the present composition containing a crosslinking agent). As the crosslinking agent, conventionally known crosslinking agents can be used without any particular limitation, and organic peroxides are preferred. When using an organic peroxide as the crosslinking agent, it is preferable to contain a conventionally known crosslinking aid. Examples of the crosslinking agent and crosslinking aid include the crosslinking agents and crosslinking aids described in International Publication No. 2019 / 180802 and the like.

[0215] The chemical crosslinking is preferably carried out under heating, and the heating conditions in this case are not particularly limited, but preferably include heating at 160 to 200° C. for about 30 minutes to 2 hours.

[0216] When the radiation crosslinking is carried out, a crosslinking agent may or may not be used. When irradiating with electron beams, it is desirable to carry out so that the absorbed dose is preferably 0.5 to 100 kGy, more preferably 0.5 to 70 kGy.

[0217] When crosslinking is performed by electron beam irradiation, the step of irradiating with electron beams may be performed multiple times so that the absorbed dose per irradiation falls within the above range. Crosslinking may be performed using a mold or without a mold. When a mold is not used, the molding and crosslinking steps are usually performed continuously. Heating in the crosslinking bath can be performed using, for example, hot air, steam, a glass bead fluidized bed, UHF (ultra-high frequency electromagnetic waves), or LCM (molten salt bath).

[0218] <Method of manufacturing rubber composition> The composition can be obtained, for example, by mixing the rubber component (A), the filler (B), the graft-modified ethylene-α-olefin copolymer (C), and the other optional components described above in a predetermined ratio by a known method.

[0219] Examples of the mixing method include a method using an extruder, a Banbury mixer, a mixing roll, a Henschel mixer, or a kneader. The rubber component (A) may be mixed with components other than the rubber component (A), or may be added to and mixed with a composition containing all components other than the rubber component (A) in the final stage of producing the composition. Alternatively, the rubber component (A), filler (B), graft-modified ethylene-α-olefin copolymer (C), and a portion of the other components optionally used may be mixed with components other than the rubber component (A) that constitute the composition, and the remaining rubber component (A) may be added and mixed in the final stage of producing the composition.

[0220] The same applies to the filler (B), the graft-modified ethylene-α-olefin copolymer (C) and the other components used as needed. Furthermore, the production of the present composition and the production of a molded body, a preform for producing a crosslinked molded body, or a crosslinked molded body may be carried out continuously, or after the production of the present composition, molding and crosslinking may be carried out separately using the present composition.

[0221] When producing a crosslinked molded article from the present composition, for example, as in the case of crosslinking general rubber, an uncrosslinked present composition (compounded rubber) may be produced once, and then this compounded rubber may be molded into the intended shape and then crosslinked.

[0222] The crosslinkable composition thus produced can be molded into an intended shape by various molding methods using an extruder, a calendar roll, a press molding machine, an injection molding machine, a transfer molding machine, or the like, and crosslinking can be carried out simultaneously with molding or by introducing the obtained molded body into a crosslinking tank.

[0223] <Molded body> The molded article according to the present invention comprises the present composition or the crosslinked body, and the present composition is preferably molded into a desired shape and then used for a desired application in terms of ease of handling, workability, etc. The present composition makes it possible to easily form a molded article of a desired shape.

[0224] The molded article is suitable for use in heat dissipation of electronic devices and electronic components that generate heat (e.g., communication devices, high-performance printers, liquid crystal displays, LED lighting, servers, car navigation systems, power supplies for hybrid and electric vehicles, personal computers, digital cameras, video game consoles, and hard disk drives), specifically as a thermal insulation material (TIM). In particular, the molded article has thermal conductivity suitable for the production of heat-dissipating sheets, and is therefore suitable for use as a TIM that improves thermal conductivity between heat-generating elements and heat-dissipating members, and between heat-dissipating members themselves. The molded article also has excellent heat resistance, and is therefore suitable for use with heat-generating elements and heat-dissipating members that may be subjected to high temperatures. Furthermore, the molded article has excellent insulating properties, and is therefore suitable for use in applications requiring insulation, such as as a substitute for insulating paper or as an insulating coating (coating layer) for electric wires or cables used in motor wires, etc.

[0225] The molded article is not particularly limited, but examples thereof include sheets, particularly heat dissipation sheets. In this specification, there is no particular distinction between sheets and films, and the term "sheet" collectively refers to membrane (plate)-shaped molded articles.

[0226] The thickness of the sheet may be appropriately selected depending on the desired application, but is preferably 0.1 to 2.0 mm, more preferably 0.2 to 1.0 mm. The molding method used for the molding is not particularly limited, and any conventionally known method can be used, including, for example, extrusion molding, compression molding, and injection molding.

[0227] <Shore A hardness of rubber composition> The Shore A hardness of a sheet obtained from the present composition is preferably less than 98, more preferably less than 90, and even more preferably less than 80, 3 seconds after the start of contact with the indenter.

[0228] Sheets with a Shore A hardness within the above range have excellent flexibility and can adhere closely to heat-generating elements and heat-dissipating components (due to their excellent conformability to the surface irregularities of heat-generating elements and heat-dissipating components), and can efficiently transfer heat from the heat-generating element to the heat-dissipating component, making them particularly suitable for use as TIMs. In particular, if the Shore A hardness of the sheet is less than 98, the sheet is less likely to become hard and brittle, and can be said to have flexibility suitable for the production of heat-dissipating sheets. The Shore A hardness is usually 10 or higher. Specifically, the Shore A hardness is measured by the method described in the Examples section below.

[0229] <Thermal conductivity of rubber composition> The thermal conductivity of the sheet obtained from the present composition is preferably 1.0 W / m·K or more, more preferably 1.5 W / m·K or more, and even more preferably 2.0 W / m·K or more.

[0230] When the thermal conductivity of the sheet is 1.0 W / m·K or more, the sheet can be said to have thermal conductivity suitable for producing a heat dissipation sheet. Specifically, the thermal conductivity is measured by the method described in the Examples section below.

[0231] <Volume resistivity of rubber composition> The volume resistivity of the sheet obtained from the composition is preferably 1.0×10 10 Ω·cm or more, preferably 1.0×10 13 Ω·cm or more, more preferably 1.0×10 15 Ω·cm or more.

[0232] The volume resistivity of the sheet is 1.0×10 10 When the electrical insulation resistance is Ω·cm or more, the sheet can be said to have electrical insulation properties suitable for producing a heat dissipation sheet. Specifically, the volume resistivity is measured by the method described in the Examples section below. [Example]

[0233] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the following examples and comparative examples, the various physical properties were measured or evaluated by the following methods.

[0234] <Acid value> Measurement and calculation were carried out according to the method described in JIS K2501:2003.

[0235] <Apparent viscosity at 150°C> Measurement and calculation were carried out according to the method described in JIS K7117-1.

[0236] <Weight average molecular weight (Mw)> Measurements and calculations were carried out by the following methods. High-speed GPC measurement device: Tosoh Corporation, HLC8320GPC Mobile phase: THF (Fujifilm Wako Pure Chemical Industries, Ltd., stabilizer-free, liquid chromatography grade) Column: Two TSKgel Super MultiporeHZ-M columns manufactured by Tosoh Corporation connected in series Sample concentration: 5mg / mL Mobile phase flow rate: 0.35mL / min Measurement temperature: 40℃ Standard sample for calibration curve: PStQuick MP-M, manufactured by Tosoh Corporation

[0237] <Melting point> The melting point was measured and calculated according to the method described in JIS K 7121. When no peak was observed or the value of the heat of fusion was 1 J / g or less, it was considered that the melting point was not observed.

[0238] [Rubber component (A)] As the rubber component (A), the following rubber component (A-1) was used. "Rubber component (A-1)": Ethylene-propylene-diene copolymer rubber (Mitsui Chemicals, Inc., Mitsui EPT3045)

[0239] Filler As the filler (B), the following fillers (B-1) and (B-2) were used. Filler (B-1): Aluminum nitride (Tokuyama Corporation, average particle size: 30 μm) Filler (B-2): Aluminum nitride (Tokuyama Corporation, average particle size: 1 μm)

[0240] [Graft-modified ethylene-α-olefin copolymer (C)] The following copolymers (C-1) to (C-4) were used as the graft-modified ethylene-α-olefin copolymer (C).

[0241] [Production Example C1] Synthesis of Graft-Modified Ethylene-α-Olefin Copolymer (C-1) (1) Preparation of ethylene-propylene copolymer (C0-1) A 2 L stainless steel autoclave, thoroughly purged with nitrogen, was charged with 760 mL of heptane and 120 g of propylene. The temperature inside the system was raised to 150°C, and then hydrogen (0.85 MPa) and ethylene (0.19 MPa) were supplied to adjust the total pressure to 3 MPaG. Next, 0.4 mmol of triisobutylaluminum, [methylphenylmethylene (η 5 -cyclopentadienyl)(η 5Polymerization was initiated by introducing 0.0002 mmol of (2,7-di-tert-butylfluorenyl)zirconium dichloride and 0.002 mmol of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate into the reactor with nitrogen pressure and adjusting the stirring speed to 400 rpm. The total pressure was then maintained at 3 MPaG by continuously supplying ethylene alone, and the polymerization was carried out at 150 °C for 5 min. The polymerization was terminated by adding a small amount of ethanol to the system, and unreacted ethylene, propylene, and hydrogen were purged. The resulting polymerization solution was washed three times with 1000 mL of 0.2 mol / L hydrochloric acid and then three times with 1000 mL of distilled water. After drying over magnesium sulfate, the solvent was removed under reduced pressure to obtain crude ethylene-propylene copolymer.

[0242] A 1-L stainless steel autoclave was charged with 100 mL of a 0.5% by weight Pd / alumina catalyst hexane solution and 500 mL of a 30% by weight hexane solution of the resulting crude ethylene-propylene copolymer. The autoclave was then sealed and purged with nitrogen. The system was then heated to 140 °C with stirring, and the pressure was purged with hydrogen. The system was then pressurized with hydrogen to 1.5 MPa and hydrogenation was carried out for 15 minutes. The reaction mixture was filtered to remove the hydrogenation catalyst, and the solvent was removed under reduced pressure. The mixture was then dried under reduced pressure at 80 °C for 24 hours to obtain ethylene-propylene copolymer (C0-1).

[0243] (2) Graft modification of ethylene-propylene copolymer (C0-1) A 200 mL glass reactor equipped with a stirrer, a nitrogen inlet, a water-cooled condenser, a thermometer, and two dropping funnels was charged with 100 g of ethylene-propylene copolymer (C0-1). After heating to 120 °C, nitrogen bubbling was initiated and the system was maintained at 160 °C. Subsequently, 6.6 g of maleic anhydride (preliminarily heated to approximately 70 °C to form a liquid) and 1.3 g of di-tert-butyl peroxide were added to each of the two dropping funnels over 5 hours. The reaction was continued for 1 hour after the completion of the addition. The system was then heated to 175 °C, depressurized, and then gradually purged with nitrogen using a vacuum pump for 1 hour to remove impurities (unreacted maleic anhydride and decomposition products of di-tert-butyl peroxide). Graft-modified ethylene-propylene copolymer (C-1) was obtained through this procedure. Its physical properties are shown in Table 1.

[0244] [Production Example C2] Synthesis of Graft-Modified Ethylene-α-Olefin Copolymer (C-2) (1) Preparation of ethylene-propylene copolymer (C0-2) In a 2-liter continuous polymerization reactor equipped with an agitator and thoroughly purged with nitrogen, 1 liter of dehydrated and purified hexane was placed, and ethylaluminum sesquichloride (Al(C2H5) 1.5 ·Cl 1.5 After continuously feeding a hexane solution of VO(OC2H5)Cl2 adjusted to 16 mmol / L as a catalyst at 500 mL / h, hexane was continuously fed at 500 mL / h. Meanwhile, the polymerization liquid was continuously withdrawn from the top of the reactor so that the volume of the polymerization liquid in the reactor was always 1 L.

[0245] Next, ethylene gas was supplied at a rate of 36 L / h, propylene gas at a rate of 36 L / h, and hydrogen gas at a rate of 30 L / h using a bubbling tube. The copolymerization reaction was carried out at 35°C by circulating a coolant through a jacket attached to the outside of the reactor. This resulted in a polymerization solution containing ethylene-propylene copolymer.

[0246] The resulting polymerization solution was washed three times with 500 mL of 0.2 mol / L hydrochloric acid per 1 L of the polymerization solution, and then three times with 500 mL of distilled water per 1 L of the polymerization solution. After drying over magnesium sulfate, the solvent was removed by distillation under reduced pressure. The resulting viscous liquid was dried under reduced pressure at 130 °C for 24 hours to obtain ethylene-propylene copolymer (C0-2).

[0247] (2) Graft modification of ethylene-propylene copolymer (C0-2) A 200 mL glass reactor equipped with a stirrer, a nitrogen inlet tube, a water-cooled condenser, a thermometer, and two dropping funnels was charged with 100 g of ethylene-propylene copolymer (C0-2). After heating to 120 °C, nitrogen bubbling was initiated and the system was maintained at 160 °C. Two dropping funnels were then charged with 2.8 g of maleic anhydride (preliminarily heated to approximately 70 °C to form a liquid) and 0.6 g of di-tert-butyl peroxide, each of which had been pre-heated to 175 °C. The reaction was continued for 1 hour after the completion of the feed. The system was then heated to 175 °C, and the pressure was gradually reduced for 1 hour while nitrogen was gradually introduced using a vacuum pump to remove impurities (unreacted maleic anhydride and decomposition products of di-tert-butyl peroxide). Graft-modified ethylene-α-olefin copolymer (C-2) was obtained through the above procedure. Its physical properties are shown in Table 1.

[0248] [Production Example C3] Synthesis of Graft-Modified Ethylene-α-Olefin Copolymer (C-3) (1) Preparation of ethylene-propylene copolymer (C0-3) In a 2-liter continuous polymerization reactor equipped with an agitator and thoroughly purged with nitrogen, 1 liter of dehydrated and purified hexane was placed, and ethylaluminum sesquichloride (Al(C2H5) 1.5 ·Cl 1.5 After continuously feeding a hexane solution of VO(OC2H5)Cl2 adjusted to 16 mmol / L as a catalyst at 500 mL / h, hexane was continuously fed at 500 mL / h. Meanwhile, the polymerization liquid was continuously withdrawn from the top of the reactor so that the volume of the polymerization liquid in the reactor was always 1 L.

[0249] Next, ethylene gas was supplied at 47 L / h, propylene gas at 47 L / h, and hydrogen gas at 20 L / h using a bubbling tube. The copolymerization reaction was carried out at 35°C by circulating a coolant through a jacket attached to the outside of the reactor. This resulted in a polymerization solution containing ethylene-propylene copolymer.

[0250] The resulting polymerization solution was washed three times with 500 mL of 0.2 mol / L hydrochloric acid per 1 L of the polymerization solution, and then three times with 500 mL of distilled water per 1 L of the polymerization solution. After drying over magnesium sulfate, the solvent was removed by distillation under reduced pressure. The resulting viscous liquid was dried under reduced pressure at 130 °C for 24 hours to obtain ethylene-propylene copolymer (C0-3).

[0251] (2) Graft modification of ethylene-propylene copolymer (C0-3) A 200 mL glass reactor equipped with a stirrer, a nitrogen inlet tube, a water-cooled condenser, a thermometer, and two dropping funnels was charged with 100 g of ethylene-propylene copolymer (C0-3). After heating to 120 °C, nitrogen bubbling was initiated and the system was maintained at 160 °C. Subsequently, 3.8 g of maleic anhydride (preliminarily heated to approximately 70 °C to form a liquid) and 0.8 g of di-tert-butyl peroxide were added to each of the two dropping funnels over 3 hours. The reaction was continued for 1 hour after the completion of the addition. The system was then heated to 175 °C, and the pressure was gradually reduced for 1 hour while nitrogen was gradually introduced using a vacuum pump to remove impurities (unreacted maleic anhydride and decomposition products of di-tert-butyl peroxide). Graft-modified ethylene-α-olefin copolymer (C-3) was obtained through the above procedure. Its physical properties are shown in Table 1.

[0252] [Production Example C4] Synthesis of Graft-Modified Ethylene-α-Olefin Copolymer (C-4) (1) Preparation of ethylene-propylene copolymer (C0-4) A 2 L stainless steel autoclave, thoroughly purged with nitrogen, was charged with 760 mL of heptane and 120 g of propylene. The temperature inside the system was raised to 150°C, and then hydrogen (0.85 MPa) and ethylene (0.19 MPa) were supplied to adjust the total pressure to 3 MPaG. Next, 0.4 mmol of triisobutylaluminum, [diphenylmethylene (η 5 -3-n-butylcyclopentadienyl)(η 5 Polymerization was initiated by introducing 0.0002 mmol of (2,7-di-tert-butylfluorenyl)zirconium dichloride and 0.002 mmol of N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate into the reactor with nitrogen pressure and adjusting the agitation speed to 400 rpm. The total pressure was then maintained at 3 MPaG by continuously supplying ethylene alone, and the polymerization was carried out for 5 min at 150 °C. The polymerization was terminated by adding a small amount of ethanol to the system, and unreacted ethylene, propylene, and hydrogen were purged. The resulting polymerization solution was washed three times with 1000 mL of 0.2 mol / L hydrochloric acid and then three times with 1000 mL of distilled water. After drying over magnesium sulfate, the solvent was removed under reduced pressure to obtain crude ethylene-propylene copolymer.

[0253] A 1-L stainless steel autoclave was charged with 100 mL of a 0.5% by weight Pd / alumina catalyst hexane solution and 500 mL of a 30% by weight hexane solution of the resulting crude ethylene-propylene copolymer. The autoclave was then sealed and purged with nitrogen. The system was then heated to 140 °C with stirring, and the pressure was increased to 1.5 MPa with hydrogen. The hydrogenation reaction was then carried out for 15 minutes. The hydrogenation catalyst was removed by filtration, the solvent was removed under reduced pressure, and the mixture was dried at 80 °C for 24 hours under reduced pressure to obtain ethylene-propylene copolymer (C0-4).

[0254] (2) Graft modification of ethylene-propylene copolymer (C0-4) A 200 mL glass reactor equipped with a stirrer, a nitrogen inlet tube, a water-cooled condenser, a thermometer, and two dropping funnels was charged with 100 g of ethylene-propylene copolymer (C0-4). After heating to 120 °C, nitrogen bubbling was initiated and the system was maintained at 160 °C. Subsequently, 6.6 g of maleic anhydride (preliminarily heated to approximately 70 °C to form a liquid) and 1.3 g of di-tert-butyl peroxide were added to each of the two dropping funnels over 5 hours. The reaction was continued for 1 hour after the completion of the addition. The system was then heated to 175 °C, and the pressure was gradually reduced for 1 hour while nitrogen was gradually introduced using a vacuum pump to remove impurities (unreacted maleic anhydride and decomposition products of di-tert-butyl peroxide). Graft-modified ethylene-α-olefin copolymer (C-4) was obtained through the above procedure. Its physical properties are shown in Table 1.

[0255] [Table 1]

[0256] [Ethylene-α-olefin copolymer] As a comparative copolymer for the graft-modified ethylene-α-olefin copolymer (C), an ethylene-α-olefin copolymer (kinematic viscosity at 100°C: 150 mm 2 / s, weight average molecular weight (Mw): 5,100, flash point: 250°C or higher, acid value: less than 0.01 mgKOH / g) was used.

[0257] [Mineral oil] Paraffinic mineral oil (Idemitsu Kosan Co., Ltd., Diana Process Oil PW-380) was used as a comparison mineral oil for the graft-modified ethylene-α-olefin copolymer (C).

[0258] [Crosslinking agent] Dicumyl peroxide (Kayacumyl D-40C, manufactured by Kayaku Nouryon Co., Ltd.) was used as the crosslinking agent.

[0259] <Examples 1 to 5 and Comparative Examples 1 to 4> The components listed in Table 2 below, except for the crosslinking agent, were mixed in a kneader to achieve the values ​​(parts by mass) listed in Table 2 below. The mixing conditions were a rotor rotation speed of 50 rpm, a set temperature of 130°C, and a mixing time of 2.5 minutes. Next, the compound was again added to the kneader, and the crosslinking agent was further added to achieve the values ​​(parts by mass) listed in Table 2 below, and mixed in the kneader. The mixing conditions were a rotor rotation speed of 40 rpm, a set temperature of 40°C, and a mixing time of 2.5 minutes. The compound was then molded into a heat-dissipating sheet with a thickness of 1.0 mm using a heat press machine, to obtain a rubber composition. The heat-press (crosslinking) conditions were a set temperature of 180°C, and a mixing time of 10 minutes.

[0260] [evaluation] <Mixing processability> The mixing processability during the production of the rubber compositions of the Examples and Comparative Examples was judged based on the ratio of deposits adhering to the inside of the kneader relative to the total amount of each component used. Rubber compositions with a ratio of deposits of less than 3% by mass relative to 100% by mass of the total of each component used in the rubber composition were rated A, less than 5% by mass B, and 5% by mass or more C. The results are shown in Table 2.

[0261] <Sticky> The stickiness of the heat-dissipating sheets manufactured in the examples and comparative examples was evaluated by placing the heat-dissipating sheet on a polyethylene terephthalate film (PET film) and leaving it for one day, and then judging the ease with which the heat-dissipating sheet could be peeled off. When peeling the heat-dissipating sheet from the PET film, a rating of A was given if there was no resistance, a rating of B if there was resistance, and a rating of C if an oily deposit was confirmed to have been transferred to the PET film. The results of the mode of evaluation by five evaluators are shown in Table 2.

[0262] <Shore A hardness> The Shore A hardness of the heat-dissipating sheets produced in the examples and comparative examples was measured in accordance with ASTM D2240. Specifically, seven 1 mm heat-dissipating sheets were stacked, and the Shore A hardness was measured three seconds after the indenter was brought into contact with the sheet. A Shore A hardness of less than 98 was rated A, and a Shore A hardness of 98 or greater was rated B. The results are shown in Table 2. A Shore A hardness of less than 98 can be said to have sufficient flexibility as a heat-dissipating sheet.

[0263] <Thermal conductivity> The thermal conductivity of the heat dissipation sheets manufactured in the examples and comparative examples was measured in accordance with ASTM E1530. Thermal conductivity of 1.0 W / m K or higher was rated A, and thermal conductivity of less than 1.0 W / m K was rated B. The results are shown in Table 2. A thermal conductivity of 1.0 W / m K or higher can be said to have sufficient thermal conductivity for use as a heat dissipation sheet.

[0264] <Volume resistivity> The volume resistivity of the heat dissipation sheets manufactured in the examples and comparative examples was measured in accordance with ASTM D257:2007. 15 Ω·cm or more is A, 1.0×10 10 Ω·cm or more is B, 1.0×10 10 The results are shown in Table 2. The volume resistivity was 1.0×10 10 If the electrical insulation resistance is Ω·cm or more, it can be said that the sheet has sufficient electrical insulation properties to be used as a heat dissipation sheet.

[0265] [Table 2]

Claims

1. The rubber composition contains a rubber component (A), a filler (B), and a graft-modified ethylene / α-olefin copolymer (C) that satisfies the following requirements (c-1) to (c-6): The filler (B) has a thermal conductivity of 10 W / m·K or more. Requirement (c-1): The graft-modified ethylene / α-olefin copolymer (C) contains a main chain portion derived from the ethylene / α-olefin copolymer (C0). Requirement (c-2): The graft-modified ethylene / α-olefin copolymer (C) contains a graft moiety derived from at least one unsaturated carboxylic acid monomer selected from the group consisting of unsaturated carboxylic acids having 3 to 10 carbon atoms and derivatives of the unsaturated carboxylic acids. Requirement (c-3) The acid value is 10 to 150 mgKOH / g. Requirement (c-4) The apparent viscosity at 150°C is 20 to 1,500 mPa·s. Requirement (c-5) The weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) is 1,500 to 25,000. Requirement (c-6) No melting point is observed by differential scanning calorimetry (DSC).

2. 2. The rubber composition according to claim 1, wherein the rubber component (A) is an ethylene-α-olefin-non-conjugated polyene copolymer rubber.

3. The rubber composition according to claim 1 , wherein the filler (B) is an aluminum compound.

4. The rubber composition according to claim 3, wherein the aluminum compound is aluminum nitride.

5. 2. The rubber composition according to claim 1, wherein the graft-modified ethylene / α-olefin copolymer (C) is a graft-modified ethylene / propylene copolymer.

6. 2. The rubber composition according to claim 1, wherein the content of the filler (B) is 100 to 2000 parts by mass and the content of the graft-modified ethylene-α-olefin copolymer (C) is 1 to 150 parts by mass, relative to 100 parts by mass of the rubber component (A).

7. A crosslinked body obtained by crosslinking the rubber composition according to any one of claims 1 to 6.

8. A molded article comprising the rubber composition according to any one of claims 1 to 6.

9. A heat dissipation sheet comprising the rubber composition according to any one of claims 1 to 6.

10. A method for producing a rubber composition, comprising the step of mixing a rubber component (A), a filler (B) having a thermal conductivity of 10 W / m·K or more, and a graft-modified ethylene / α-olefin copolymer (C) that satisfies the following requirements (c-1) to (c-6): Requirement (c-1): The graft-modified ethylene / α-olefin copolymer (C) contains a main chain portion derived from the ethylene / α-olefin copolymer (C0). Requirement (c-2): The graft-modified ethylene / α-olefin copolymer (C) contains a graft moiety derived from at least one unsaturated carboxylic acid monomer selected from the group consisting of unsaturated carboxylic acids having 3 to 10 carbon atoms and derivatives of the unsaturated carboxylic acids. Requirement (c-3) The acid value is 10 to 150 mgKOH / g. Requirement (c-4) The apparent viscosity at 150°C is 20 to 1,500 mPa·s. Requirement (c-5) The weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) is 1,500 to 25,000. Requirement (c-6) No melting point is observed by differential scanning calorimetry (DSC).

11. The method for producing a rubber composition according to claim 10, further comprising the step of producing the graft-modified ethylene / α-olefin copolymer (C) by the following method (α): Method (α): a step (S1) of copolymerizing ethylene and an α-olefin in the presence of an olefin polymerization catalyst containing a bridged metallocene compound (P) represented by the following formula [I], and at least one compound (Q) selected from the group consisting of an organometallic compound (Q-1), an organoaluminum oxy compound (Q-2), and a compound (Q-3) that reacts with the bridged metallocene compound (P) to form an ion pair, to obtain an ethylene-α-olefin copolymer (C0); a step (S2) of adding the unsaturated carboxylic acid monomer to the ethylene / α-olefin copolymer (C0) to graft-modify the ethylene / α-olefin copolymer (C0); A method comprising: 【Chemical 1】 [In formula [I], R 1 , R 2 , R 3 , R 4 , R 5 , R 8 , R 9 and R 12 are each independently a hydrogen atom, a hydrocarbon group, or a silicon-containing hydrocarbon group, and R 1 ~R 4 two adjacent groups may be linked to each other to form a ring structure, R 6 and R 11 are the same group and are a hydrogen atom, a hydrocarbon group, or a silicon-containing hydrocarbon group, R 7 and R 10 are the same group and are a hydrogen atom, a hydrocarbon group, or a silicon-containing hydrocarbon group, R 6 and R 7 may be bonded to a hydrocarbon having 2 to 3 carbon atoms to form a ring structure, R 10 and R 11 may be bonded to a hydrocarbon having 2 to 3 carbon atoms to form a ring structure, R 6 , R 7 , R 10 and R 11 is not a hydrogen atom at the same time, Y is a carbon atom or a silicon atom; R 13 and R 14 are each independently a hydrogen atom, a hydrocarbon group, or a silicon-containing hydrocarbon group, and may be linked together to form a ring structure, M is a titanium atom, a zirconium atom, or a hafnium atom; j is an integer from 1 to 4, Q is a halogen atom, a hydrocarbon group, an anionic ligand, or a neutral ligand capable of coordinating to a lone electron pair, and when j is an integer of 2 or greater, multiple Qs may be the same or different.

12. In the formula [I], R 13 and R 14 The method for producing a rubber composition according to claim 11, wherein either one or both of the following is an aryl group:

13. In the formula [I], R 13 and R 14 are both aryl groups, and R 2 and R 3 The method for producing a rubber composition according to claim 11, wherein either one of the above is a saturated hydrocarbon group having 4 carbon atoms.

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