JP2012140509A - Foam-molded article, heat-conductive molded article and method of producing the same, and heat-conductive sheet laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a foam-molded article where low-molecular siloxane is not generated, which is excellent in insulation properties and flexibility (unevenness followability), and which exhibits excellent heat conductivity by being compressed moderately.SOLUTION: The foam-molded article comprises: a polymer component (A) having a sea-island structure with a thermoplastic resin (a-1) as a sea phase and with a rubber component (a-2) as an island phase; and a heat-conductive filler (B). The content ratio of the heat-conductive filler (B) is 70 to 1,000 pts.vol based on 100 pts.vol of the thermoplastic resin (a-1).

Description

  The present invention relates to a thermally conductive molded article suitable as a constituent member of an electric / electronic device, a method for producing the same, a thermally conductive sheet laminate, and a foam molded article capable of producing the thermally conductive molded article.

  In recent years, foam molded articles have been used in many product fields as shock absorbers and soft tactile parts for interior and exterior parts of automobiles, home appliances and information devices, and soft tactile parts. As a raw material capable of forming such a foamed molded article, a thermoplastic elastomer composition that is easy to mold and foam easily is attracting attention. As such a thermoplastic elastomer composition, a thermoplastic elastomer composition that can be dynamically crosslinked can be exemplified, and it is known that a foam molded article can be obtained using this thermoplastic elastomer composition (for example, , See Patent Document 1).

  Various polymer materials are known as materials (heat dissipating materials) for constituting heat dissipating members incorporated in various electric / electronic devices. As a related art, a thermally conductive composition containing a specific organopolysiloxane, an organohydrogenpolysiloxane, and a filler such as metal silicon powder, metal, or metal oxide (for example, Patent Document 2) And 3), and a silicone-based thermally conductive composition such as a composition containing a thermoplastic silicone resin, an aluminum powder, and a zinc oxide powder (see, for example, Patent Document 4).

  In addition, a heat conductive sheet (for example, see Patent Document 5) formed by molding a composition containing a specific acrylic copolymer resin emulsion, a flame retardant, and a heat conductive filler, or a specific molecular structure A molded body exhibiting thermal conductivity (heat dissipation) such as a heat dissipation sheet (see, for example, Patent Document 6) formed by molding a heat dissipation material containing (modified) SEBS having zinc, zinc oxide, and a flame retardant. It is disclosed.

JP-A-6-73222 JP 2007-138100 A JP 2008-38137 A JP 2007-150349 A JP 2005-146166 A JP 2008-163145 A

  However, the composition used for the thermally conductive molded body may contain an organopolysiloxane or the like, and low molecular siloxane is generated with use, resulting in inconveniences such as causing a contact failure in an electronic component. There was a problem. Moreover, even if it is the composition disclosed by patent documents 2-6 etc., and the heat conductive molded object obtained using them, it may not necessarily be said that the heat conductivity is always sufficient, There is a need for further improvements.

  Conventionally, when a non-foamed molded body having high thermal conductivity is to be produced, it has been necessary to blend a large amount of a heat conductive material such as a heat conductive filler with respect to the polymer material. However, a polymer material containing a large amount of a heat conductive material has high heat conductivity, but its flexibility is impaired, and it is difficult to follow unevenness of a heat sink or a substrate. Therefore, at present, the contact thermal resistance with the substrate interface is large while having excellent thermal conductivity, and the original thermal conductivity cannot be sufficiently obtained.

  The present invention has been made in view of such problems of the prior art, and the problem is that low molecular siloxane is not generated and not only excellent in insulation but also flexible (following irregularities). It is an object of the present invention to provide a foamed molded article that exhibits excellent thermal conductivity by being suitably compressed.

  Further, the subject of the present invention is that a low-molecular-weight siloxane does not occur and is not only excellent in insulation, but also in heat resistance, flexibility (irregularity followability) and heat conductivity, and its production. It is to provide a method.

  Furthermore, the subject of the present invention is to provide a thermally conductive sheet laminate that does not generate low-molecular siloxane and not only has excellent insulating properties but also has excellent flexibility (irregularity followability) and thermal conductivity. There is to do.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have adjusted the content ratio of the thermally conductive filler in a foamed molded article containing a polymer component having a specific sea-island structure and a thermally conductive filler. The present inventors have found that the above-described problems can be achieved and have completed the present invention.

  That is, according to the present invention, the following foamed molded product, thermally conductive molded product and method for producing the same, and a thermally conductive sheet laminate are provided.

  (A-1) containing a thermoplastic resin as a sea phase, (a-2) a (A) polymer component having a sea-island structure containing a rubber component as an island layer, and (B) a thermally conductive filler, (B) The foaming molding whose content ratio of a heat conductive filler is 70-1000 volume parts with respect to 100 volume parts of said (a-1) thermoplastic resins.

  The manufacturing method of the heat conductive molded object which has the process of compressing the foaming molded object of this invention to 5 to 90% of compression ratio, and obtaining a heat conductive molded object.

  The heat conductive molded object manufactured by the manufacturing method of the heat conductive molded object of this invention.

  A heat comprising a sheet comprising the thermally conductive molded body of the present invention, an adhesive layer disposed on one surface of the sheet, and a base material layer disposed on the other surface of the sheet. Conductive sheet laminate.

  The foamed molded article of the present invention does not generate low molecular siloxane, is excellent not only in insulation properties but also in flexibility (unevenness followability), and exhibits excellent thermal conductivity by being appropriately compressed. There is an effect.

  The method for producing a thermally conductive molded body according to the present invention is a method of producing a thermally conductive molded body that does not generate low-molecular siloxane and is excellent not only in insulating properties but also in flexibility (unevenness followability) and thermal conductivity. There is an effect that it can be easily manufactured.

  The thermally conductive molded article of the present invention does not generate low molecular siloxane, and has an effect that it is excellent not only in insulating properties but also in flexibility (unevenness followability) and thermal conductivity.

  The thermally conductive sheet laminate of the present invention does not generate low-molecular siloxane, and has an effect of being excellent not only in insulating properties but also in flexibility (unevenness followability) and thermal conductivity.

  Embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments. It is understood that the scope of the present invention includes modifications, improvements, and the like as appropriate to the following embodiments based on ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. Should.

I. Foam molding:
The foamed molded article of the present invention comprises (A) a polymer component having a sea-island structure containing (a-1) a thermoplastic resin as a sea phase and (a-2) a rubber component as an island phase, and (B) a thermal conductivity. And a filler. Moreover, the content ratio of (B) heat conductive filler is 70-1000 volume parts with respect to 100 volume parts of (a-1) thermoplastic resin.

1. Thermoplastic elastomer composition:
The foam-molded article of the present invention can be produced by foam-molding a thermoplastic elastomer composition containing (A) a polymer component and (B) a thermally conductive filler. The thermoplastic elastomer composition may contain additives and the like in addition to (A) the polymer component and (B) the thermally conductive filler. Hereinafter, each component of the thermoplastic elastomer composition will be described in detail.

(1) (A) Polymer component:
(A) A polymer component is a structural component provided with the sea-island structure which consists of the sea phase used as a matrix, and the island phase disperse | distributed to the island shape in the sea phase. The sea phase is a phase comprising (a-1) a thermoplastic resin. Moreover, an island phase is a phase which consists of (a-2) rubber components.

(I) (a-1) Thermoplastic resin:
A thermoplastic resin is a component that affects properties. Examples of the thermoplastic resin used in the present invention include olefinic thermoplastic resins such as polyethylene, polypropylene, polymethylpentene, and ethylene-propylene copolymer; polystyrene, AS resin, polyvinyl acetate, polyvinyl alcohol, and ethylene-vinyl acetate. Copolymer, ethylene-vinyl alcohol copolymer, polyvinyl butyral, polymethyl methacrylate, halogen-containing hydrocarbon, main chain composed of carbon and nitrogen, main chain oxygen and nitrogen-containing polyimide, main chain oxygen Polyester containing oxygen, polyether containing oxygen in the main chain, polythioether containing sulfur in the main chain, polyether containing both oxygen and sulfur in the main chain, cycloolefin polymer (COP) and the like. Among these, α-olefin-based thermoplastic resins are preferably used from the viewpoints of the fluidity of the thermoplastic elastomer composition, which is a raw material of the foam molded body, and the mechanical strength and heat resistance as the foam molded body.

  (A-1) A thermoplastic resin may be used individually by 1 type, and may use 2 or more types. For example, the α-olefin-based thermoplastic resin described above may be a homopolymer of α-olefin or a copolymer of two or more α-olefins, other than α-olefin and α-olefin. It may be a copolymer with a monomer. Two or more α-olefin thermoplastic resins may be used in combination. When the thermoplastic resin is a copolymer, this copolymer may be either a random copolymer or a block copolymer.

The (a-1) thermoplastic resin may be a crystalline resin (hereinafter also referred to as “crystalline resin”) or an amorphous resin (hereinafter also referred to as “amorphous resin”). It may be. Whether it is a crystalline resin or an amorphous resin is determined by the crystallinity of the thermoplastic resin measured by X-ray diffraction. Specifically, if the degree of crystallinity of the thermoplastic tree measured by X-ray diffraction is 50% or more, it is determined as a crystalline resin, and if it is less than 50%, it is determined as an amorphous resin. Further, since the degree of crystallinity is closely related to the density, it can be determined by the density instead of the X-ray diffraction. When the crystallinity of the thermoplastic resin is 50% or more, the density is 0.89 g / cm ³ or more.

  The crystalline resin is preferably a resin whose main component is a structural unit derived from an α-olefin. By using such a crystalline resin, the mechanical strength of the foamed molded product is improved. Here, “having a structural unit derived from an α-olefin as a main component” means that the structural unit derived from an α-olefin is contained in an amount of 80% by mass or more when the entire crystalline resin is 100% by mass. It is preferable to contain 90 mass% or more.

  The maximum peak temperature of the crystalline resin measured by differential scanning calorimetry, that is, the melting point (Tm) is preferably 100 ° C. or higher, more preferably 120 ° C. or higher. When Tm of crystalline resin is 100 degreeC or more, moderate heat resistance and intensity | strength can be maintained as a foaming molding.

  The melt flow rate (MFR) of the crystalline resin at a temperature of 230 ° C. and a load of 21.2 N is preferably 0.1 to 100 g / 10 min, and more preferably 0.5 to 80 g / 10 min. When the MFR of the crystalline resin is 0.1 g / 10 min or more, moderate kneading processability, extrusion processability, etc. can be maintained as the thermoplastic elastomer composition. On the other hand, when the MFR is 100 g / 10 min or less, it is possible to maintain an appropriate strength as the foamed molded product.

  From the above points, as a preferred example of the crystalline resin, the content ratio of ethylene units is 20% by mass or less, Tm is 100 ° C. or more, and MFR is 0.1 to 100 g / 10 min. (1) Mention may be made of polypropylene, (2) a copolymer of propylene and ethylene, or (3) a copolymer of propylene, ethylene and 1-butene.

  The amorphous resin is preferably a resin whose main component is a structural unit derived from an α-olefin, like the above-described crystalline resin. By using such an amorphous resin, there is an advantage that the adhesive strength with the adherend is improved when the obtained thermoplastic elastomer composition is injection-fused together with the vulcanized rubber or the thermoplastic elastomer. Here, “having a structural unit derived from an α-olefin as a main component” means that the α-olefin is contained in an amount of 50% by mass or more when the total amount of the amorphous resin is 100% by mass. It is preferable to contain it by mass% or more.

  Specific examples of the amorphous resin include homopolymers such as atactic polypropylene and atactic poly-1-butene; copolymers of propylene and other α-olefins; 1-butene and other α-olefins; And the like. The copolymer of propylene and the other α-olefin is preferably such that the content ratio of the structural unit derived from propylene is 50% by mass or more with respect to the entire copolymer, and the other α-olefin. Are, for example, ethylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene and the like. Further, the copolymer of 1-butene and other α-olefin is preferably such that the content of the structural unit derived from 1-butene is 50% by mass or more based on the whole copolymer. The α-olefin is preferably ethylene, propylene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, or the like.

  The melt viscosity at 190 ° C. of the amorphous resin is preferably 50000 mPa · s or less, more preferably 1000 to 40000 mPa · s, and particularly preferably 2000 to 30000 mPa · s. When the melt viscosity is 50000 mPa · s or less, the moldability of the resulting thermoplastic elastomer composition can be maintained.

  (A-1) As the thermoplastic resin, at least one thermoplastic resin having a strain hardening degree SH of 0.1 to 0.5 (hereinafter also referred to as “resin (a′-1)”) is used. preferable. By using the resin (a′-1), a thermoplastic elastomer composition having excellent foamability at the time of molding can be obtained. The strain hardening degree SH of the resin (a′-1) is 0.1 to 0.5, preferably 0.15 to 0.45, and preferably 0.2 to 0.4. Further preferred. When the strain hardening degree SH is 0.1 or more, the foamability of the thermoplastic resin is improved. On the other hand, when the strain hardening degree SH is 0.5 or less, the fluidity of the thermoplastic resin is improved. The resin (a′-1) is more preferably an α-olefin thermoplastic resin having a strain hardening degree SH of 0.1 to 0.5.

  (A-1) When the resin (a′-1) is used as the thermoplastic resin, a thermoplastic resin having a strain hardening degree SH outside the above range may be used in combination. A high degree of compatibility between the thermoplastic resin having a strain hardening degree SH outside the above range and (B) the heat conductive filler is preferable because the melt ductility of the thermoplastic elastomer composition can be increased.

  The ratio of the resin (a′-1) is preferably 10 to 95% by mass and more preferably 40 to 95% by mass with respect to 100% by mass of the (a-1) thermoplastic resin. By setting the ratio of the resin (a′-1) to 95% by mass or less, the flexibility of the foamed molded article can be favorably maintained.

  As the resin (a′-1), polypropylene, ethylene-propylene copolymer, and ethylene-butene copolymer are preferable. Two or more kinds of resins (a′-1) can be used in combination.

(Ii) (a-2) Rubber component:
(A-2) A rubber component is a component which affects the deformation | transformation recoverability from the compression state of a foaming molding. In other words, the foamed molded article of the present invention has (a-2) a rubber component to improve the deformation / restorability and, for example, penetrates into the concave / convex concave portions of the surface of the substrate or the like (follows the concave / convex portions) without any gap. Can do. Therefore, the adhesion between the substrate surface and the foamed molded product (thermally conductive molded product) is improved, and heat can be radiated more efficiently. Examples of such (a-2) rubber component include (oil-extended) ethylene-based copolymers and cross-linked products thereof, olefin-based thermoplastic elastomer compositions, styrene-based thermoplastic elastomers (compositions), and the like. Among these, an (oil-extended) ethylene copolymer and a crosslinked product thereof are preferable. The above-mentioned “(oil-extended) ethylene copolymer” means an oil-extended or non-oil-extended ethylene-based copolymer.

(Ethylene copolymer)
Specific examples of the ethylene copolymer include an ethylene / α-olefin binary copolymer and an ethylene / α-olefin / non-conjugated polyene terpolymer.

  The proportion of the structural unit derived from ethylene contained in the ethylene-based copolymer is preferably 50 to 80% by mass, more preferably 54 to 75% by mass, and particularly preferably 60 to 70% by mass. When the content ratio of the structural unit derived from ethylene is within the above range, there is an advantage that the balance between mechanical strength and flexibility of the thermoplastic elastomer composition is improved. In addition, by being 50 mass% or more, even if it is a case where an organic oxide is used as a crosslinking agent, the fall of crosslinking efficiency can be suppressed. On the other hand, by being 80 mass% or less, the fall of the softness | flexibility of a thermoplastic elastomer composition can be suppressed.

  The α-olefin is preferably an α-olefin having 3 to 20 carbon atoms, more preferably an α-olefin having 3 to 12 carbon atoms, and particularly preferably an α-olefin having 3 to 8 carbon atoms. Specific examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene and 1-decene. Among these, propylene, 1-butene, 1-hexene and 1-octene are preferable from the viewpoint of easy industrial availability, and propylene is more preferable. In addition, these alpha olefins can be used individually by 1 type or in combination of 2 or more types.

  Specific examples of the non-conjugated polyene include cyclic polyenes such as 5-ethylidene-2-norbornene and dicyclopentadiene; internals having 6 to 15 carbon atoms such as 1,4-hexadiene and 4-methyl-1,4-hexadiene Examples of the chain polyene having an unsaturated bond include α, ω-dienes such as 1,5-hexadiene and 1,6-heptadiene. Among these, 5-ethylidene-2-norbornene, dicyclopentadiene, 5-vinyl-2-norbornene, 7-methyl-1,6-octadiene and 5-methyl-1,4-hexadiene are preferable, and 5-ethylidene is preferable. 2-norbornene is more preferred. In addition, these nonconjugated polyenes can be used individually by 1 type or in combination of 2 or more types.

  The proportion of structural units derived from non-conjugated polyene contained in the ethylene / α-olefin / non-conjugated polyene terpolymer is such that the iodine value of ethylene / α-olefin / non-conjugated polyene terpolymer is 40 or less. It is preferable that it is the ratio which becomes, and it is still more preferable that it is the ratio used as 30 or less. The iodine value is a value that serves as a measure of the proportion of structural units derived from the non-conjugated polyene contained in the ethylene / α-olefin / non-conjugated polyene terpolymer. By setting the iodine value to 40 or less, gelation hardly occurs at the time of kneading, and generation of scum in a molding process such as extrusion can be suppressed.

  The ethylene-based copolymer can be prepared by, for example, a gas phase polymerization method, a solution polymerization method, or a slurry polymerization method. These polymerization methods may be batch or continuous. In the solution polymerization method and the slurry polymerization method, an inert hydrocarbon can be used as a reaction medium. Specific examples of the inert hydrocarbon solvent include aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, n-octane, n-decane and n-dodecane; alicyclic rings such as cyclohexane and methylcyclohexane Aromatic hydrocarbons such as benzene, toluene, xylene and the like. In addition, these hydrocarbon solvents can be used individually by 1 type or in combination of 2 or more types.

  The polymerization catalyst used when preparing the ethylene-based copolymer includes, for example, one or more transition metal compounds selected from the group consisting of V, Ti, Zr, and Hf, and an organometallic compound. Examples thereof include olefin polymerization catalysts.

  Specific examples of the olefin polymerization catalyst include (1) a metallocene compound and an organoaluminum compound, or (2) a metallocene catalyst comprising a metallocene compound and an ionic compound that reacts with the metallocene compound to form an ionic complex, or (3) A Ziegler-Natta catalyst comprising a vanadium compound and an organoaluminum compound can be exemplified. In preparing the ethylene copolymer, hydrogen gas can be used as a molecular weight regulator. The amount of hydrogen gas used varies depending on the polymerization conditions such as the catalyst type, the catalyst amount, the polymerization temperature, and the polymerization pressure, or the polymerization process such as the polymerization scale, the stirring state, and the charging method. In solution polymerization using a Ziegler-Natta catalyst, the amount of hydrogen gas used is preferably 0.01 to 20 ppm, more preferably 0.1 to 10 ppm, based on all monomer components.

The ethylene copolymer preferably satisfies the following conditions (1) and (2). An ethylene-based copolymer that satisfies the following conditions (1) and (2) is an oil-extended ethylene that has been subjected to an oil-extended treatment to improve the molding processability and flexibility of the thermoplastic elastomer composition and to improve the appearance of the product. When the copolymer is used, there are advantages in that the number of molecular chain terminals having poor deformation recovery properties is small and the content ratio of the ultrahigh molecular weight component having a high melt viscosity is small.
(1): The intrinsic viscosity [η] measured at 135 ° C. in a decalin solvent is 4.0 to 9.0 dl / g.
(2): The value (Mw / Mn) of the weight average molecular weight (Mw) and the number average molecular weight (Mn) is 4 or less.

  The intrinsic viscosity [η] of the ethylene copolymer measured in a decalin solvent at 135 ° C. is preferably 4.0 to 9.0 dl / g, more preferably 4.0 to 8.5 dl / g. More preferably, it is 4.5-8.5 dl / g, Most preferably, it is 5.0-8.0 dl / g. When the intrinsic viscosity [η] is 4.0 dl / g or more, the rubber elasticity of the ethylene copolymer can be favorably maintained. On the other hand, by being 9.0 dl / g or less, the increase in the viscosity of an ethylene-type copolymer can be suppressed and industrial productivity can be maintained favorable. The intrinsic viscosity [η] can be measured using, for example, an Ubbelohde viscometer.

  The value of the ratio (Mw / Mn) between the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the ethylene copolymer is preferably 2.0-4 or less, more preferably 2.0-3. .8. When the value of “Mw / Mn” is 4 or less, rubber elasticity, softener retention, and moldability can be maintained well. The “weight average molecular weight (Mw)” is a value in terms of polystyrene measured using gel permeation chromatography (GPC).

  In the GPC chromatogram of the ethylene copolymer, the area ratio (area ratio of the low molecular weight component) of the area having a molecular weight of 100,000 or less in terms of polystyrene is preferably 3 area% or less in the total molecular weight area. Particularly preferably, it is 2.5 area% or less. When the area ratio is 3 area% or less, the rubber elasticity and softener retention of the thermoplastic elastomer composition can be maintained well.

(Oil-extended ethylene copolymer)
The ethylene-based copolymer may be used as it is, but it is preferable to use a mineral oil-based softening agent as an oil-extended ethylene-based copolymer. The oil-extended ethylene-based copolymer improves the rubber elasticity of the thermoplastic elastomer composition when the number of molecular chain terminals having poor deformation recovery properties is small. Moreover, when there is little content rate of an ultra high molecular weight component with high melt viscosity, dispersibility with other components (for example, (a-1) thermoplastic resin) becomes favorable, and the mechanical strength of a thermoplastic elastomer composition is good. improves. Furthermore, when the content ratio of the low molecular weight component is small, the retention of the mineral oil-based softener is good, and a large amount of the mineral oil-based softener can be blended to improve the molding processability of the thermoplastic elastomer composition. To do.

  Specific examples of mineral oil softeners include aromatic, naphthenic, and paraffinic mineral oil softeners. Among these, paraffinic or naphthenic mineral oil softeners having high compatibility with ethylene-α-olefin thermoplastic elastomers and excellent weather resistance are preferable.

  The blending amount of the mineral oil softener is preferably 50 to 150 parts by weight, more preferably 80 to 140 parts by weight, and particularly preferably 90 to 130 parts by weight with respect to 100 parts by weight of the ethylene copolymer. Part. By setting the blending amount of the mineral oil softener to 50 parts by mass or more, the flexibility and molding processability of the thermoplastic elastomer composition can be maintained well. On the other hand, by setting it as 150 mass parts or less, stickiness does not generate | occur | produce in a thermoplastic elastomer composition, and industrial productivity can be maintained favorable.

(Olefin-based thermoplastic elastomer composition)
Examples of the olefin thermoplastic elastomer composition include those obtained by dynamically heat-treating an ethylene copolymer and an α-olefin resin. Specific examples include “EXCELLINK series” (manufactured by JSR), “Thermo Run series” (manufactured by Mitsubishi Chemical), “Miralastomer series” (manufactured by Mitsui Chemicals), “Oreflex series” ( Riken Technos), “Santoprene Series” (ExxonMobil Chemical), “SARLINK Series” (DSM), and the like.

(Styrenic thermoplastic elastomer)
Examples of the styrenic thermoplastic elastomer include a styrene block copolymer composed of at least one styrene block and a conjugated diene block mainly composed of at least one conjugated diene, and a hydrogenated product of the styrene block copolymer. Can be mentioned. As specific examples, “DYNARON series” (manufactured by JSR), “SEPTON series”, “SEPTON-V series” (manufactured by Kuraray), “KRATON G series” (manufactured by Kraton Polymer Co., Ltd.) And the like.

(Styrenic thermoplastic elastomer composition)
Examples of the styrenic thermoplastic elastomer composition include those obtained by dynamically heat-treating the hydrogenated styrene block copolymer and an α-olefin resin. Specific examples include “Lavalon series” (Mitsubishi Chemical Co., Ltd.), “Activimer series”, “Rheostomer series” (above, Riken Technos), “Elastomer AR series” (Aron Kasei Co., Ltd.). Manufactured).

  (A-2) The content ratio of the rubber component is preferably 25 to 95% by mass, more preferably 35 to 90% by mass, and still more preferably 40 to 100% by mass with respect to 100% by mass of the (A) polymer component. 90% by mass. (A-2) When the ratio of the rubber component is within the above range, the balance between rubber elasticity (deformation resilience) and fluidity of the foamed molded article is good. (A-2) The fluidity | liquidity of a thermoplastic elastomer composition can be favorably maintained by the ratio of a rubber component being 25 mass% or more. On the other hand, the fall of the rubber elasticity (deformation recovery property) of a thermoplastic elastomer composition can be suppressed by making the ratio of the (a-2) rubber component into 95 mass% or less.

((A) Polymer component preparation method)
When (A) the polymer component is (a-2) when the rubber component is dynamically heat-treated in advance, a polymer composition comprising (a-1) a thermoplastic resin and (a-2) a rubber component Can be prepared simply by melt mixing. On the other hand, when (a-2) the rubber component has not been dynamically heat-treated in advance, such as an (oil-extended) ethylene copolymer, (a-1) a thermoplastic resin and (oil-extended) ethylene-based copolymer Can be prepared by dynamically heat-treating a polymer composition containing

  “Dynamically heat-treating” means melting, kneading, and dispersing the polymer composition and the like in the presence of a crosslinking agent, and performing a crosslinking reaction of the (oil-extended) ethylene-based copolymer or the like. To do. By dynamically heat-treating in this way, a large number of island phases containing (a-2) rubber components partially or wholly crosslinked float in the sea phase containing (a-1) thermoplastic resin. A (A) polymer component having a so-called “sea-island structure” (dispersed) can be prepared.

  The temperature during the dynamic heat treatment is preferably 150 to 250 ° C. When the heat treatment is dynamically performed within this temperature range, the balance between (a-1) melting of the thermoplastic resin and the crosslinking reaction tends to be good. The time required for the dynamic heat treatment is preferably 20 seconds to 320 minutes, more preferably 30 seconds to 25 minutes. The shearing force to be applied is a shear rate, preferably 10 to 20000 / second, and more preferably 100 to 10,000 / second.

  Examples of apparatuses used for “dynamic heat treatment” include batch kneaders such as a pressure kneader, a banbury mixer, and a brabender; A continuous kneader; an apparatus in which these devices are combined can be exemplified.

(Mineral oil softener)
(A) A mineral oil softener may be added to the polymer component for the purpose of imparting moldability and flexibility and improving the appearance of the product. As the mineral oil softener, the same mineral oil softener as described above can be used. Of these, paraffinic or naphthenic compounds having high compatibility with ethylene copolymers and excellent weather resistance are preferred.

  The blending amount of the mineral oil-based softener ((a-2) When an oil-extended ethylene copolymer is used as the rubber component, the mineral oil-based softener used in the oil expansion is also added) is (A) It is preferable that it is 50-150 mass parts with respect to 100 mass parts of total amounts of a polymer component, It is still more preferable that it is 80-140 mass parts, It is especially preferable that it is 90-130 mass parts. By setting the blending amount to 150 parts by mass or less, bleeding out of the mineral oil-based softening agent can be suppressed, and deterioration of the appearance of the product can be suppressed.

(Crosslinking agent)
The cross-linking agent is not particularly limited as long as it is usually used for cross-linking ethylene copolymers such as EPM and EPDM. Specific examples of the crosslinking agent include sulfur, sulfur compounds, organic peroxides, phenol resin crosslinking agents, quinoid crosslinking agents, acrylic acid metal salt crosslinking agents, bismaleimide crosslinking agents, and the like.

  The amount of the crosslinking agent is preferably 0.02 to 20 parts by weight, more preferably 0.1 to 12 parts by weight, and particularly preferably with respect to 100 parts by weight of the total amount of the (A) polymer component. 0.4 to 3 parts by mass. By being 0.02 parts by mass or more, a sufficient crosslinking reaction can be performed, and a decrease in rubber elasticity can be suppressed. On the other hand, the fluidity | liquidity fall can be suppressed because it is 20 mass parts or less.

  In the case of using an organic peroxide as a crosslinking agent, it is preferable that an appropriate crosslinking aid is present because the crosslinking reaction is performed uniformly and gently, and particularly uniform crosslinking can be formed. The blending amount of the crosslinking aid is preferably 3 parts by mass or less, more preferably 0.2 to 2 parts by mass with respect to 100 parts by mass of the total amount of the (A) polymer component. When the blending amount of the crosslinking aid is within this range, there is an advantage that the uniformity of the phase structure (sea-island structure) of the (A) polymer component is improved and the molding processability is maintained. By setting the blending amount of the crosslinking aid to 3 parts by mass or less, the crosslinking aid is prevented from remaining in the thermoplastic elastomer composition as an unreacted monomer, and the thermoplastic elastomer composition is molded. It is possible to prevent the thermoplastic elastomer composition from changing its physical properties due to the thermal history.

  Moreover, when using a phenol resin type crosslinking agent or a quinoid type crosslinking agent as a crosslinking agent, you may use independently, but in order to adjust a crosslinking rate, you may use together with a crosslinking accelerator.

(Other ingredients)
(A) Polymer components include anti-aging agents, antioxidants, antistatic agents, weathering stabilizers, UV absorbers, lubricants, antiblocking agents, sealability improvers, crystal nucleating agents, flame retardants, antibacterial agents Additives such as agents, fungicides, tackifiers, softeners, plasticizers, colorants, fillers and the like may be added as appropriate. These additives may be added after (A) the polymer component is dynamically heat-treated in the presence of a crosslinking agent (that is, after (A) the polymer component is formed).

(2) (B) Thermally conductive filler:
(B) The insulating property and thermal conductivity of the thermally conductive filler are important. Non-insulating (having electrical conductivity) fillers cannot be used in fields where electrical insulation is required. (B) The thermal conductivity of the thermally conductive filler is preferably 3 W / (m · K) or more, more preferably 10 W / (m · K) or more, and 20 W / (m · K) or more. It is particularly preferred that (B) When the thermal conductivity of the thermally conductive filler is 3 W / (m · K) or more, the thermal conductivity of the thermoplastic elastomer composition can be efficiently improved.

  (B) Specific examples of the thermally conductive filler include metal oxides such as alumina, magnesium oxide, zinc oxide, and beryllium oxide; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; boron nitride, aluminum nitride, and nitride Examples thereof include nitrides such as silicon; silica powders such as quartz and crystalline silica. Among these, from the viewpoint of improving thermal conductivity, at least one selected from the group consisting of metal oxides, metal hydroxides, nitrides, and silica powders is preferable, and is at least one of boron nitride and alumina. More preferably. These (B) thermally conductive fillers can be used singly or in combination of two or more. In addition, for the purpose of improving wettability with the polymer component (A) serving as a matrix, it is also preferable to use a surface-treated (B) thermally conductive filler.

  (B) The shape of a heat conductive filler is not specifically limited. (B) Specific examples of the shape of the heat conductive filler include a spherical shape, a needle shape, a fiber shape, a scale shape, a dendritic shape, a flat plate shape, and an indefinite shape. Moreover, the (B) heat conductive filler may be hollow. In the foamed molded article of the present invention, (B) the heat conductive filler is oriented around the periphery of the formed bubbles (foamed cells), and the formation of the heat conduction path is promoted. Therefore, from the viewpoint of promoting the formation of the heat conduction path in the orientation direction, the (B) heat conductive filler is preferably in the form of fibers, flakes, or plates having an aspect ratio greater than 1.

  (B) The number average particle diameter of the thermally conductive filler is preferably 0.1 to 100 μm, more preferably 0.5 to 50 μm, and particularly preferably 1 to 20 μm. (B) When the number average particle diameter of a heat conductive filler is 0.1 micrometer or more, the increase in the viscosity of a thermoplastic elastomer composition can be suppressed and fluidity | liquidity can be maintained favorable. On the other hand, when the number average particle diameter is 100 μm or less, not only the fluidity of the thermoplastic elastomer composition is good, but also a decrease in foamability can be suppressed.

  (B) Content of a heat conductive filler is 70-1000 volume part with respect to 100 volume part of (a-1) thermoplastic resins, Preferably it is 80-800 volume part, More preferably, it is 100-600. Volume part. (B) When the content of the heat conductive filler is 70 parts by volume or more, the heat conductivity of the foamed molded article can be favorably maintained. On the other hand, by being 1000 parts by volume or less, the fluidity of the thermoplastic elastomer composition can be favorably maintained.

  In addition, as "(B) volume of thermally conductive filler", a value obtained by dividing the blending weight of (B) thermally conductive filler by true specific gravity is used. In addition, when the true specific gravity of the filler is unknown, it can be calculated by image analysis of a cross-sectional photograph of the molded body. Specifically, (a-1) the area ratio of the thermoplastic resin and the filler in the cross section obtained by using image analysis software (trade name “Image-Pro Plus”, manufactured by Nippon Rover Co., Ltd.) is expressed as a volume ratio ((a -1) volume parts relative to 100 parts by volume of thermoplastic resin). In addition, the cross-sectional photograph of a molded object can be obtained from the transmission electron microscope observation etc. which are demonstrated by the evaluation method of the sea island structure mentioned later.

  (B) “(B) Volume of thermally conductive filler” in the case where the thermally conductive filler is hollow is the volume when (B) the thermally conductive filler is assumed to be solid (solid). means. The (B) thermally conductive filler is preferably present in at least the sea phase of the (A) polymer component. (B) Since the thermally conductive filler is present at least in the sea phase, (B) the thermally conductive filler is widely distributed in the foam molded body, and the thermal conductivity of the foam molded body (thermally conductive molded body). Can be improved. Further, when (B) the thermally conductive filler is present in the sea phase, when the thermoplastic elastomer composition is foamed, (B) the thermally conductive filler is likely to be unevenly distributed in the state of being oriented at the periphery of the foam cell, The thermal conductivity of the foamed molded product can be further improved.

2. Production method:
The foam-molded article of the present invention can be produced by foam-molding a thermoplastic elastomer composition containing (A) a polymer component and (B) a thermally conductive filler. In the foamed molded article of the present invention, since the thermally conductive filler (B) is unevenly distributed at the periphery of the formed foam (foamed cell), a heat conduction path is formed by compression, and the thermal conductivity is improved. That is, a compressed body (thermally conductive molded body) obtained by appropriately compressing the foamed molded body of the present invention is in a state before foaming (thermoplastic elastomer composition) or in a non-compressed state (foamed molded body). In comparison, the thermal conductivity is improved. For this reason, even if there are few compounding quantities of (B) heat conductive filler, the heat conductive molded object which has sufficiently high heat conductivity can be manufactured. In addition, since the foamed molded article of the present invention is flexible, it can follow and adhere closely to the unevenness of a heat sink, a substrate, etc., and can reduce the contact thermal resistance with the substrate interface and improve the thermal conductivity.

(1) Thermoplastic elastomer composition:
The thermoplastic elastomer composition contains (A) a polymer component and (B) a thermally conductive filler, and can produce a foam molded article by foam molding.

  The melt flow rate (MFR) of the thermoplastic elastomer composition is preferably 0.1 to 100 g / 10 min, more preferably 0.5 to 80 g / 10 min, particularly at 230 ° C. and 98 N load. Preferably it is 1-60g / 10min. When MFR is 100 g / 10 min or less, when producing a foamed molded article, the foaming ratio is high, independent bubbles can be formed, and the shape of the formed bubbles can be made uniform. On the other hand, when the MFR is 0.1 g / 10 min or more, the workability and the like of the foamed molded product can be favorably maintained.

  The thermal conductivity of the thermoplastic elastomer composition is preferably 0.5 to 100 W / (m · K), more preferably 0.7 to 100 W / (m · K), and 1.0 to 100 W / (m · K) is particularly preferable. When the thermal conductivity is 0.5 W / (m · K) or more, the thermal conductivity of the foamed molded article can be favorably maintained.

The volume resistivity value of the thermoplastic elastomer composition is preferably 10 ¹² Ω · cm or more, and more preferably 10 ¹⁴ Ω · cm or more, in order to maintain sufficient insulation.

  The strain hardening degree SH of the thermoplastic elastomer composition is preferably 0.1 to 0.5, more preferably 0.15 to 0.45, and preferably 0.2 to 0.4. Particularly preferred. When the strain hardening degree SH is 0.1 or more, the foamability can be maintained well. On the other hand, when it is 0.5 or less, the moldability can be maintained satisfactorily.

  The melt ductility of the thermoplastic elastomer composition is preferably 10 to 200 m / min, more preferably 10 to 150 m / min, and particularly preferably 11 to 100 m / min. When the melt ductility is 10 m / min or more, the foamed cell can be prevented from being broken in foam molding. On the other hand, when the melt ductility is 200 m / min or less, it is possible to suppress shrinkage of the foam cell in foam molding.

(2) Foaming method:
The manufacturing method of a foaming molding should just foam-mold a thermoplastic elastomer composition. As the foaming method, for example, the thermoplastic elastomer composition is adjusted to a temperature (° C.) of 1.15 times or more of the loss tangent tan δ peak temperature Tp (° C.) and impregnated or mixed with a gas or a supercritical fluid, After adjusting the temperature to 1.00 to 1.10 times the loss tangent tan δ peak temperature Tp (° C.), the temperature is 1.00 to 1.10 times the loss tangent tan δ peak temperature Tp (° C.) ( In a state where the pressure is reduced at (° C.), the thermoplastic elastomer composition can be foamed using a gas or a supercritical fluid.

  Specifically, first, the temperature of the thermoplastic elastomer composition is not less than 1.15 times its loss tangent tan δ peak temperature Tp (° C.), preferably not less than 1.18 times Tp (° C.), more preferably Adjusts the temperature to 1.20 to 1.30 times Tp (° C.). Next, a foamable raw material is obtained by impregnating or mixing a molten thermoplastic elastomer composition with a gas or a supercritical fluid. By adjusting the temperature of the thermoplastic elastomer composition so as to be in the above temperature range, it is preferable because the gas or supercritical fluid to be impregnated or mixed can be easily dispersed uniformly.

  As the supercritical fluid, it is preferable to use a supercritical fluid of carbon dioxide or nitrogen. For example, in the case of carbon dioxide, a supercritical state can be obtained by setting the temperature to 31 ° C. or higher and the pressure to 7.3 MPa or higher. Carbon dioxide becomes supercritical at a relatively low temperature and pressure, has a high impregnation rate into a molten thermoplastic elastomer composition, and can be mixed at a high concentration. It is suitable and fine bubbles can be obtained. As the gas, carbon dioxide, nitrogen, air or the like is preferably used.

  Next, the foamable raw material is a temperature not more than 1.10 times the loss tangent tan δ peak temperature Tp (° C.) of the thermoplastic elastomer composition used as the raw material, preferably 1.00 to 1.09 of Tp (° C.). The temperature is adjusted to twice the temperature, more preferably 1.02 to 1.08 times Tp (° C.). The foaming ratio can be increased by adjusting the temperature of the foamable raw material to be in the above temperature range. Further, independent bubbles can be formed, and the shape of the formed bubbles can be made uniform.

  The foamable raw material after temperature adjustment is usually at a temperature of 1.10 times or less of Tp (° C.), preferably 1.00 to 1.09 times of Tp (° C.), more preferably Tp (° C.). A foam-molded article can be produced by decompressing at a temperature 1.02 to 1.08 times and foam-molding the foamable raw material. The method of foaming is not particularly limited, and may be either a batch method or a continuous method. Specifically, foam molding can be performed by a molding method such as extrusion molding, injection molding, or press molding.

  The case where a foam is manufactured using an extruder will be described more specifically. First, a thermoplastic elastomer composition is put into an extruder and melted. Next, a gas or supercritical fluid is impregnated or mixed to obtain a foamable raw material in a molten high pressure state. After the foamable raw material in a molten high pressure state impregnated or mixed with a gas or a supercritical fluid is reduced in pressure toward the atmospheric pressure toward the outlet of the extruder and foamed in the middle of the pressure reduction, The foam can be produced by cooling and solidifying the molten foam that has come out.

  When a gas or a supercritical fluid is injected into a molten thermoplastic elastomer composition and mixed uniformly, the apparent viscosity is lowered, so that the fluidity is improved. Further, when the thermoplastic elastomer composition is subjected to foam molding using a gas or a supercritical fluid, the expansion ratio can be increased. Furthermore, it is easy to control the number average cell diameter of the foam cells of the foam molded article. Moreover, it is easy to control the cushion feeling of the foamed molded product. Furthermore, when a gas or a supercritical fluid is used, the number average cell diameter of the foamed cells of the foamed molded product can be reduced and the cell diameter of the foamed cells can be made uniform.

  In addition, when using normal gas, it is difficult to raise a foaming ratio compared with the case where a supercritical fluid is used. However, when a normal gas is used, it is possible to produce a foamed molded article with inexpensive equipment.

3. Physical properties:
The number average cell diameter of the foamed cells of the foamed molded article of the present invention is preferably 10 to 200 μm, more preferably 15 to 180 μm, and particularly preferably 20 to 180 μm. The coefficient of variation (Cv) of the number average cell diameter is preferably 0.1 to 1.0, more preferably 0.1 to 0.9, and particularly preferably 0.1 to 0.8. It is. By setting the number average cell diameter of the foamed cells and the coefficient of variation (Cv) of the number average cell diameter to the above-described range, variation in the cell diameter of the foamed cells is reduced, and (B) heat in the entire foamed molded product The distribution state of the conductive filler can be made substantially uniform. The foamed molded product of the present invention and the sheet-like thermally conductive molded product obtained by compressing this by making the distribution state of the thermally conductive filler (B) in the entire foamed molded product almost uniform Also, the in-plane uniformity of heat conductivity is extremely high. The number average cell diameter of the foamed cells is preferably 10 μm or more from the viewpoint of reliably showing the effect of foaming, that is, flexibility and the like. Moreover, the foaming ratio of a foaming molding can be favorably maintained by setting it as 10 micrometers or more. On the other hand, when the number average cell diameter of the foamed cells is 200 μm or less, variations in the cell diameter of the foamed cells are reduced, and the in-plane uniformity of the thermal conductivity of the foamed molded product and the thermally conductive molded product is improved. Moreover, the increase in compression set can also be suppressed by setting it as 200 micrometers or less.

  The foamed molded article of the present invention preferably has a foaming ratio of 3 to 30 times, more preferably 4 to 25 times, and more preferably 5 to 20 times when foaming the thermoplastic elastomer composition. Is particularly preferred. When foam molding is performed at a foaming ratio in the above range, a foam molded article excellent in flexibility (unevenness followability) and surface appearance can be produced.

  As will be described later, the foamed molded article of the present invention is improved in thermal conductivity by being compressed. The foamed molded product of the present invention preferably has a thermal conductivity after compression of 0.5 to 100 W / (m · K), more preferably 0.7 to 100 W / (m · K), It is particularly preferably 1.0 to 100 W / (m · K). The thermal conductivity after compression is preferably 0.5 W / (m · K) or more from the viewpoint of maintaining the thermal conductivity of the foamed molded product.

Moreover, it is preferable that the foaming molding of this invention satisfy | fills the following conditions.
Condition: [thermal conductivity (W / (m · K)) when compressed to 60% compression ratio of foamed molded product]] / [thermal conductivity of molded foam (W / (m · K))] ≧ 2

  In addition, the above [thermal conductivity (W / (m · K)) when compressed to 60% compression ratio of foamed molded product]] / [thermal conductivity of foamed molded product (W / (m · K))] The value of is more preferably 2-20.

  The foamed molded article of the present invention preferably has a hardness (duro E) of less than 70, more preferably less than 50, and particularly preferably less than 30. That is, it is preferable to be excellent in flexibility. Here, the hardness (duro E) is a value measured according to JIS K6253.

The foamed molded article of the present invention preferably has a volume resistivity of 10 ¹² Ω · cm or more, more preferably 10 ¹⁴ Ω · cm or more. That is, it is preferable that the insulating property is excellent.

II. Thermally conductive molded body and method for producing the same:
The manufacturing method of the heat conductive molded object of this invention is the compression rate of 5-90%, Preferably the compression rate of 10-80%, More preferably, the compression rate of 15 It is a method having a step of obtaining a thermally conductive molded body by compressing to ˜70%. Moreover, the heat conductive molded object of this invention is manufactured by the manufacturing method of the heat conductive molded object of this invention. In addition, when a compressibility is 5% or more, the contact of (B) heat conductive fillers in a heat conductive molded object can be increased, and sufficient heat conductivity can be maintained. On the other hand, when the compressibility is 90% or less, the bubbles (foamed cells) in the thermally conductive molded body are prevented from being crushed, and the thermal conductive molded body has good flexibility (unevenness followability). Can be maintained.

  The foamed molded product in an uncompressed (pre-compressed) state is unevenly distributed with the (B) thermally conductive filler oriented on the periphery of the foamed cell. The thermally conductive molded article of the present invention obtained by compressing a foam molded article that is unevenly distributed with the thermal conductive filler oriented in the periphery of the foam cell to a predetermined compression ratio is ) Thermally conductive fillers come into contact with each other, and a thermal conduction path is formed. Therefore, the heat conductive molded body of the present invention has improved thermal conductivity as compared with that before foaming (thermoplastic elastomer composition) and in the non-compressed state (foamed molded body).

  The thermal conductivity of the thermally conductive molded article (compressed foam molded article) of the present invention is preferably 0.5 to 100 W / (m · K), and 0.7 to 100 W / (m · K). Is more preferable, and 1.0 to 100 W / (m · K) is particularly preferable.

  The heat conductive molded object of this invention has a heat conductive path formed when (B) heat conductive filler contact | connects. For this reason, the thermally conductive molded body of the present invention makes use of its excellent shape followability, thermal conductivity (heat dissipation), etc., and constitutes an electric / electronic device such as a semiconductor device having a complicated uneven shape. It can be suitably used as a member.

  As a method of compressing the foamed molded product (foamed sheet) when forming the thermally conductive molded product, there is no particular limitation as long as the foamed molded product does not melt and the foamed cells do not disappear. Examples of the compression method include a roll press and a pressure press. Moreover, when producing modules, such as a board | substrate etc. in which the heat conductive molded object was integrated, it can manufacture by incorporating in a manufacturing process the foaming molded object in the compressed state.

III. Thermally conductive sheet laminate:
The thermally conductive sheet laminate of the present invention includes a sheet comprising the thermally conductive molded body described in “II. Thermally Conductive Molded Body and Method for Producing the Same”, and an adhesive layer disposed on one surface of the sheet. And a base material layer disposed on the other surface of the sheet. For this reason, the heat conductive sheet laminated body of this invention is excellent in a softness | flexibility (uneven | corrugated followable | trackability), and excellent in heat conductivity.

  The sheet which comprises a heat conductive sheet laminated body consists of a heat conductive molded object which compressed the foaming molding which foam-molded the thermoplastic elastomer composition. For this reason, the heat conductive sheet laminated body of this invention provided with this sheet | seat shows the outstanding heat conductivity. Specifically, the thermal conductivity of the thermally conductive sheet laminate of the present invention when a thermally conductive molded body obtained by compressing a foam molded body to a compression rate of 60% is 0.5 to 100 W / (m. K) is preferable, 0.7 to 100 W / (m · K) is more preferable, and 1.0 to 100 W / (m · K) is particularly preferable.

  The pressure-sensitive adhesive layer can be disposed, for example, by applying a general pressure-sensitive adhesive composition on one surface of the sheet. Moreover, as a material which comprises a base material layer, polyester, a polypropylene, polyethylene etc. can be mentioned, for example.

  Although the thickness of the sheet | seat which consists of a heat conductive molded object is not specifically limited, Usually, 0.05-5 mm, Preferably it is about 0.1-3 mm.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples.

(1) Various physical property value measurement methods and various property evaluation methods:
[Intrinsic viscosity [η] (dl / g)]:
Using an Ubbelohde viscometer, the intrinsic viscosity [η] at 135 ° C. in a decalin solvent of the ethylene copolymer was measured.

[Mw / Mn]:
Gel permeation chromatography (trade name “PL-GPC220”, manufactured by Polymer Laboratories) was used to measure the weight average molecular weight (Mw) and number average molecular weight (Mn) of the ethylene copolymer. Mw / Mn was calculated from the measured values of Mw and Mn. In addition, the brand name "MIXED-B" by a polymer laboratory company was used for the column. In addition, orthodichlorobenzene was used for the mobile phase, and a differential refractometer was used for the detector. The measurement temperature was 135 ° C. and the sample concentration was 0.1% by mass.

[Area ratio of low molecular weight component (area%)]:
From the chromatogram obtained by measurement under the same conditions as the gel permeation chromatography described in “Mw / Mn”, the area ratio of the region having a molecular weight of 100,000 or less in the total molecular weight region was calculated.

[Flowability (MFR) (g / 10 min)]:
According to JIS K7210, MFR (melt flow rate) was measured under conditions of temperature: 230 ° C. and load: 98N. The measured MFR value was used as an evaluation value of fluidity. It can be evaluated that the larger the MFR value, the better the fluidity.

[Thermal conductivity (W / (m · K))]:
Using a thermal diffusivity / thermal conductivity measuring device (trade name “EIFASE MOBILE 1u”, manufactured by IPHASE Co., Ltd.), the thermal conductivity of the thermoplastic elastomer composition under the conditions based on ISO 22007-3 Was measured to evaluate thermal conductivity. For the foamed molded product (foamed sheet), the thermal conductivity X of the uncompressed foamed sheet (shown as “non-compressed (X) (W / (m · K))” in the table) and 60% compression The thermal conductivity Y (shown as “60% compression (Y) (W / (m · K))” in the table) of the foamed sheet (thermally conductive molded body) in the state was measured. Moreover, the change rate (Y / X) of thermal conductivity obtained by calculation of “Y / X” (shown as “change rate (Y / X)” in the table) was calculated.

[Tan δ peak temperature Tp (° C.)]:
A test piece of 5 mm × 70 mm was obtained by punching out a 1 mm thick sheet obtained by hot pressing the thermoplastic elastomer composition at 210 ° C. with a dumbbell cutter. From the room temperature to 200 ° C. using a solid viscoelasticity measuring device (trade name “RSA-II”, manufactured by TA Instruments Inc.) under the conditions of a three-point bending mode and a frequency of 1 Hz. The loss tangent tan δ of was measured. The peak temperature of the curve obtained by plotting the measured loss tangent tan δ against temperature was defined as “Tp (° C.)”. When a plurality of peaks were observed, the temperature of the peak with the highest height was defined as “Tp (° C.)”.

[Strain hardening degree SH]:
A 10 mm × 18 mm test piece was obtained by punching with a dumbbell cutter from a 1 mm thick sheet obtained by hot pressing the thermoplastic elastomer composition at 210 ° C. The viscoelasticity measuring device (trade name “ARES-RDA”, manufactured by TA Instruments) and the extensional viscosity measuring jig (trade name “ARES-EVF”, TEA Stretch viscosity [η] was measured using the following conditions.
Measurement temperature: tan δ peak temperature Tp × 1.05 (° C.)
Strain rate: 0.1 s ⁻¹ and 1 s ⁻¹

  At this time, according to the description in “Journal of Japanese Society of Rheology, Vol. 13, pages 93-100 (1985)”, the strain hardening degree SH was calculated from the extension viscosity [η] and the Hencky strain [ε] by the following formula. In addition, it can be evaluated that distortion hardening property is excellent, so that the value of strain hardening degree SH is large.

λ＝η_１／η_０１（但し、η_１は歪み速度１ｓ^−１のときの伸張粘度であり、η_０１は歪み速度０．１ｓ^−１のときの伸張粘度である）
ε＝Ｈｅｎｃｋｙ歪み

λ = η ₁ / η ₀₁ (where η ₁ is the extensional viscosity at a strain rate of 1 s ⁻¹ and η ₀₁ is the extensional viscosity at a strain rate of 0.1 s ⁻¹ )
ε = Henky distortion

[Melt extensibility (m / min)]:
Using a melt spreadability measuring device (trade name “Melt Tension Tester Type II”, manufactured by Toyo Seiki Seisakusho Co., Ltd.), the melt of the thermoplastic elastomer composition is drawn from the blowout opening (orifice) into a string (strand shape). It was. At this time, the take-up speed was increased from 0.1 m / min to 60 m / min, and the take-up speed (m / min) when the strand (string) was cut was measured. In addition, it can be evaluated that the melt ductility is more excellent as the value of the take-up speed is larger.
Measurement temperature: tan δ peak temperature Tp (° C.) × 1.05
Air outlet (orifice) diameter: 2mm diameter
Extrusion speed: 10.0mm / min

[Volume Specific Resistance (Ω · cm)]:
The volume resistivity value was measured under the condition of an applied voltage of 100 V using a volume resistivity measuring device (trade name “PRγ”, manufactured by Combex).

[Siloxane generation]:
Headspace Gas Chromatography (Headspace part: trade name “JTD-505II”, manufactured by Nippon Analytical Industrial Co., Ltd., Gas chromatograph: trade name “HP6890”, manufactured by Agilent Technologies, Inc., mass spectrometry part: trade name “JMS-Q1000GC K9” ", Manufactured by JEOL Ltd.) and volatile components were evaluated. The low molecular weight siloxane is a cyclic siloxane having a degree of polymerization of 20 or less, and usually represented as Dn, where the unit of — (CH ₃ ) ₂ SiO— is D. Siloxane generation was evaluated from the concentration of Dn bodies contained in volatile components. The case where the concentration (ppm) of the Dn body was less than 0.1 was evaluated as “possible”, and the case where the concentration was 0.1 or more was evaluated as “impossible”.

[Sea-island structure]:
Using the thermoplastic elastomer composition molded into a sheet, thin film pieces in the thickness direction were prepared using a freeze microtome method. After the produced thin film piece was stained with RuO ₄ , a photograph with a magnification of 2000 times was taken with a transmission electron microscope. In dyeing with RuO ₄ , the dark part is an oil-extended ethylene copolymer, and the bright part is a thermoplastic resin. Therefore, the components of the sea-island structure were determined based on the difference in brightness between the sea phase and the island phase. At this time, the sea-island structure was evaluated according to the following criteria.
Yes: A sea-island structure comprising a sea phase composed of a thermoplastic resin and an island phase composed of an oil-extended ethylene copolymer dispersed in the sea phase is observed.
Impossible: A sea-island structure including a sea phase composed of an oil-extended ethylene-based copolymer and an island phase composed of a thermoplastic resin dispersed in the sea phase is observed.
−: The sea-island structure cannot be observed.

[(B) Thermally conductive filler is present in the sea phase]:
Whether or not (B) a thermally conductive filler exists in the sea phase was confirmed using a transmission electron micrograph taken in the sea island structure evaluation method. The case where (B) the heat conductive filler was present in the sea phase of the polymer component (A) was evaluated as “Yes”, and the case where the heat conductive filler (B) was not present in the polymer component (A) was evaluated as “not possible”. In the table, “(B) Thermally conductive filler is present in the sea phase” is shown.

[Foaming property (foaming ratio)]:
The specific gravity of the thermoplastic elastomer composition (before foaming) and the foamed molded product (after foaming) was measured according to JIS K7112, and the foaming ratio was calculated using the following formula. In addition, it can be evaluated that it is excellent in foamability, so that the value of a foaming ratio is large. A case where the expansion ratio was 3 times or more was evaluated as “possible”, and a case where the expansion ratio was less than 3 times was evaluated as “impossible”.
“Expansion ratio” = [specific gravity before foaming (thermoplastic elastomer composition)] / [specific gravity after foaming (foamed molding)]

[Foamed cells: number average cell diameter (μm), coefficient of variation (Cv)]:
Using a magnifying glass (trade name “VHX-200”, manufactured by Keyence Co., Ltd.), a cut surface photograph of 200 times magnification of the expanded molded body (foam sheet) frozen with liquid nitrogen and cut with a razor I took a picture. Using image analysis software (trade name “ImagePro-Plus 6.2”, manufactured by Nippon Roper Co., Ltd.), the number average cell diameter (μm) of the foamed cells in the cut surface photograph is measured, and the coefficient of variation Cv of the number average cell diameter Was calculated. The case where the number average cell diameter was 10 to 200 μm was evaluated as “possible”, and the case where the number average cell diameter was less than 10 μm or more than 200 μm was evaluated as “not possible”. Also. A case where the coefficient of variation (Cv) was 0.1 to 1.0 was evaluated as “possible”, and a case where the coefficient of variation was more than 1.0 was evaluated as “impossible”.

[Hardness (Duro E)]:
The hardness (duro E) of the foamed molded product (foamed sheet) was measured in accordance with JIS K6253. A case where the hardness was less than 70 was evaluated as “possible”, and a case where the hardness was 70 or more was regarded as “impossible”.

(2) (a-2) Synthesis of rubber component:
(Synthesis Example 1)
While supplying hexane continuously at a rate of 65 L / h from the lower supply port of a stainless steel autoclave having an internal volume of 10 liters substituted with nitrogen, ethylene, propylene, and 5-ethylidene-2-norbornene are respectively supplied. It was continuously fed at a rate of 0.80 Nm ³ / h, 2.0 L / h, and 0.11 L / h. At the same time, ethylaluminum sesquichloride and vanadium trichloride are continuously supplied at a rate of 13.585 g / h and 0.384 g / h, respectively, and hydrogen is continuously supplied at a rate of 0.4 NL / h. The copolymerization reaction was conducted under the conditions of temperature: 22 ° C. and pressure: 1 MPa to obtain an ethylene copolymer. The obtained ethylene copolymer had an intrinsic viscosity [η] of 6.7 dl / g, a value of Mw / Mn of 2.4, and an area ratio of low molecular weight components of 0.5 area%. The proportions of ethylene units, propylene units, and 5-ethylidene-2-norbornene units contained in the ethylene-based copolymer are 67.0% by mass and 26.5% by mass in 100% by mass of all structural units. And 6.5% by mass.

  To 100 parts by mass of the obtained ethylene-based copolymer, 120 parts by mass of a mineral oil-based softener (trade name “Diana Process PW90”, manufactured by Idemitsu Kosan Co., Ltd.) for oil expansion was added and stirred. Steam stripping was performed to obtain an oil-extended ethylene copolymer. The obtained oil-extended ethylene copolymer was used as a rubber component (a-2-1).

(Synthesis Example 2)
An oil-extended ethylene-based copolymer was obtained in the same manner as in Synthesis Example 1 except that hydrogen was continuously supplied at a rate of 0.5 NL / h. The obtained oil-extended ethylene copolymer was used as a rubber component (a-2-2).

(Synthesis Example 3)
Catalysts ethyl ethyl sesquichloride and vanadium trichloride were continuously fed at a rate of 14.75 g / h and 0.461 g / h, respectively, and copolymerization was carried out while maintaining the polymerization temperature at 23 ° C. Except that, an oil-extended ethylene copolymer was obtained in the same manner as in Synthesis Example 1. The obtained oil-extended ethylene copolymer was used as a rubber component (a-2-3).

(3) Various components used:
<(A-1) Thermoplastic resin>
(A-1-1): Propylene / ethylene random copolymer (crystalline resin) (trade name “Prime Polypro B241”, manufactured by Prime Polymer Co., Ltd., density: 0.91 g / cm ³ , MFR (temperature: 230 ° C., (Load: 21.2 N): 0.5 g / 10 min, Tm: 143 ° C., elution amount at 80 ° C .: 15%)
(A-1-2): Propylene / ethylene / 1-butene amorphous copolymer (amorphous resin) (trade name “Vestoplast 828”, manufactured by Evonik Degussa, melt viscosity at 190 ° C .: 25000 mPa · s)
(A′-1-3): Propylene / ethylene copolymer (a thermoplastic resin (α-olefin-based thermoplastic resin) having a strain hardening degree of 0.1 to 0.5) (trade name “NEWSTREN SH9000”) Manufactured by Nippon Polypro Co., Ltd., MFR (230 ° C., 21 N): 0.5 g / 10 min, strain hardening degree SH = 0.3)
(A-1-4): Propylene / ethylene copolymer (trade name “Prime Polypro E233-GV”, manufactured by Prime Polymer Co., Ltd., MFR (230 ° C., 21 N): 1.5 g / 10 min, strain hardening degree SH = 0 .05)

<(A-2) Rubber component>
(A-2-1): Oil-extended ethylene copolymer obtained in Synthesis Example 1 (a-2-2): Oil-extended ethylene-based copolymer obtained in Synthesis Example 2 (a-2-3) ): Oil-extended ethylene copolymer obtained in Synthesis Example 3 (a-2-4): Olefin-based thermoplastic elastomer composition (dynamically heat-treated rubber component) (trade name “Santoprene 101-73” ( Density d = 0.97), manufactured by ExxonMobil Chemical Co.)
(A-2-5): Styrenic thermoplastic elastomer composition (dynamically heat-treated rubber component) (trade name “Lavalon SJ5400” (density d = 1.10), manufactured by Mitsubishi Chemical Corporation)

<Mineral oil softener>
Product name “Diana Process Oil PW90”, manufactured by Idemitsu Kosan Co., Ltd.

<Crosslinking agent>
2,5-dimethyl-2,5-di (t-butylperoxy) hexane (trade name “Perhexa 25B-40”, manufactured by NOF Corporation)

<Crosslinking aid>
Divinylbenzene (trade name “Divinylbenzene (81%)”, manufactured by Nippon Steel Chemical Co., Ltd.)

<Anti-aging agent>
Pentaerythritol tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (trade name “Irganox 1010”, manufactured by Ciba Specialty Chemicals)

<(B) Thermally conductive filler>
(B-1): Boron nitride (number average particle diameter: 18 μm, flake shaped, thermal conductivity 60 W / (m · K)
(B-2): Boron nitride (number average particle size: 1.3 μm, flat plate shape, thermal conductivity 60 W / (m · K)
(B-3): Alumina (number average particle size: 10 μm, spherical, thermal conductivity 30 W / (m · K)

<Foaming nucleating agent>
Calcium carbonate (trade name “WS-K”, manufactured by Takehara Chemical Industries Ltd.)

<Foaming agent>
Azodicarbonamide (trade name “Vinihole AC # 3”, manufactured by Eiwa Chemical Industry Co., Ltd.)

(4) Production of thermoplastic elastomer composition:
(Reference Example 1)
2.5 parts of thermoplastic resin (a-1-1), 2.5 parts of thermoplastic resin (a-1-2), 45 parts of oil-extended ethylene copolymer (a-2-1), and anti-aging 0.05 part of the agent was put into a pressure kneader (manufactured by Moriyama Co., Ltd.) heated to 150 ° C., and kneaded at 40 rpm for 15 minutes until each component was uniformly dispersed to obtain a molten composition. The obtained composition in a molten state was pelletized using a feeder ruder (manufactured by Moriyama Co., Ltd.), and then 0.8 part of a crosslinking agent and 0. 6 parts were added and mixed for 30 seconds using a Henschel mixer. Next, using a gravimetric feeder, a twin screw extruder (same direction non-meshing screw, L / D = 38.5, manufactured by Ikekai Co., Ltd., product name “PCM-45”) is supplied at a discharge rate of 40 kg / h. It was extruded while being subjected to dynamic heat treatment at 200 ° C., a screw rotation speed of 300 rpm, and a residence time of 2 minutes to obtain heat-treated pellets.

  After mixing 51.45 parts of the obtained heat-treated pellets, 174 parts of the heat conductive filler (B-1), 50 parts of the thermoplastic resin (a′-1-3), and 1 part of the foam nucleating agent, the mixture was heated to 180 ° C. The mixture was put into a heated pressure kneader (manufactured by Moriyama Co., Ltd.) and kneaded at 40 rpm for 10 minutes until each component was uniformly dispersed to obtain a molten composition. The obtained composition in a molten state was pelletized using a feeder ruder (manufactured by Moriyama Co., Ltd.) to obtain a pellet-shaped thermoplastic elastomer composition (1). In addition, the content ratio of the (B) heat conductive filler with respect to 100 volume parts of (a-1) thermoplastic resin was 124 volume parts. This content ratio was calculated by image analysis of a cross-sectional photograph of the pellet-shaped thermoplastic elastomer composition. Specifically, (a-1) a thermoplastic resin (thermoplastic resin (a-1-1)) in a cross-section obtained using image analysis software (trade name “Image-Pro Plus”, manufactured by Nippon Rover Co., Ltd.) And the area ratio of the thermoplastic resin (a-1-2)) and (B) the heat conductive filler (heat conductive filler (B-1)) to the volume ratio ((a-1) 100 volumes of the thermoplastic resin. The volume was calculated assuming that the volume part).

The resulting thermoplastic elastomer composition (1) has a fluidity (MFR) of 11 g / 10 min, a thermal conductivity of 0.80 W / (m · K), a tan δ peak temperature Tp of 168 ° C., and a strain hardening degree SH of 0. .20, the melt ductility is 11 m / min, the volume resistivity is more than 10 ¹⁴ Ω · cm (indicated as “> 10 ¹⁴ ” in the table), and the evaluation of siloxane generation is “possible”. The evaluation of the sea-island structure was “OK”, and (B) the thermally conductive filler was present in the sea phase (indicated as “OK” in the table).

(Reference Examples 2 to 16, Comparative Reference Examples 1 to 3)
Except having set it as the mixing | blending prescription shown in Table 2 or Table 3, it carried out similarly to the above-mentioned reference example 1, and obtained the pellet-shaped thermoplastic elastomer composition (2)-(16). Table 2 or Table 3 shows the results of physical properties evaluation of the obtained thermoplastic elastomer compositions (2) to (16). In Comparative Reference Example 2, a thermoplastic elastomer composition could not be obtained by adding and mixing a predetermined amount (2000 parts by mass) of a heat conductive filler. In Comparative Reference Example 2, since the amount of the thermoplastic resin was too small, a predetermined amount of the thermally conductive filler could not be added, and a thermoplastic elastomer composition could not be obtained.

(Comparative Reference Example 4)
Instead of the thermoplastic elastomer composition, a commercially available PDMS thermal conductive material (trade name “BFG80”, manufactured by Denki Kagaku Kogyo Co., Ltd.) was used. The PDMS thermal conductive material was evaluated for thermal conductivity, volume resistivity, siloxane generation, and sea-island structure. The evaluation results are shown in Table 3.

(5) Production of foam molded body (foamed sheet):
Example 1
The thermoplastic elastomer composition (1) obtained in Reference Example 1 was put into a single screw extruder, and supercritical carbon dioxide was injected and mixed at 202 ° C. Thereafter, the temperature decreases as it advances toward the tip of the single-screw extruder, and the temperature is set so that the temperature at the die outlet becomes 176 ° C., and extrusion molding is performed, thereby forming a sheet-like foamed molded article (foamed sheet, thickness: 1.0 mm). The foaming ratio of the obtained foamed sheet is 6 times, the thermal conductivity at the time of non-compression (foamed sheet) is 0.1 W / (m · K), and the thermal conductivity at the time of 60% compression (thermally conductive molding) is 1.4 W / (m · K), thermal conductivity change magnification (Y / X) is 12 times, hardness (duro E) is 28, volume resistivity is more than 10 ¹⁴ Ω · cm (in the table, “> 10 ¹⁴ ”).

(Examples 2 to 13 and 15, Comparative Examples 1 to 3)
Example 1 described above except that the thermoplastic elastomer composition of the type shown in Table 4 or 5 is used, and the die exit temperature is set to the temperature shown in Table 4 or Table 5 and extrusion molding is performed. In the same manner as above, a sheet-like foamed molded product (foamed sheet, thickness: 1.0 mm) was obtained. Tables 4 and 5 show the results of various evaluations of the obtained foamed molded product.

(Comparative Example 4)
Thermoplastic elastomer composition (12) 213.1 parts, crosslinking agent 0.8 parts, crosslinking aid 0.6 parts, foaming agent 1.0 part, foaming nucleating agent 2.0 parts heated to 150 ° C. The mixture was put into a kneader (manufactured by Moriyama Co., Ltd.) and kneaded at 40 rpm for 5 minutes until each component was uniformly dispersed to obtain a molten composition. The resulting molten composition was molded into a 120 mm × 120 mm × 0.5 mm sheet using a press preheated to 160 ° C. This sheet-like molded article was heated in a 190 ° C. gear oven for 40 minutes to foam simultaneously with static crosslinking to obtain a crosslinked foam sheet having a thickness of 1.0 mm. Table 5 shows various evaluation results of the obtained crosslinked foamed sheet.

(Examples 14 and 16)
The thermoplastic elastomer composition (14) was put into a single screw extruder and melt kneaded at 200 ° C. Thereafter, the temperature decreases as it advances toward the tip of the single-screw extruder, and the temperature is set so that the temperature at the die outlet becomes 176 ° C., and extrusion molding is performed, thereby forming a sheet-like foamed molded article (foamed sheet, thickness: 1.0 mm) was obtained (Example 14). In Example 16, a foamed molded article was obtained in the same manner as in Example 14 except that the thermoplastic elastomer (16) was used.

(Comparative Example 5)
For the same PDMS thermal conductive material (trade name “BFG80”, manufactured by Denki Kagaku Kogyo Co., Ltd.) as in Comparative Reference Example 4, the thermal conductivity (uncompressed), hardness (Duro E), and volume resistivity were evaluated. It was. The evaluation results are shown in Table 5.

(Evaluation)
As shown in Tables 4 and 5, the thermoplastic elastomer compositions (1) to (11) and (14) to (16) obtained in Reference Examples 1 to 11 and 14 to 16 have very little generation of siloxane. Met. Moreover, if such thermoplastic elastomer compositions (1) to (11) and (14) to (16) are used, the change rate of the thermal conductivity is high, and the addition amount of a small amount of the thermally conductive filler is excellent. It is apparent that a foamed molded article (foamed sheet) exhibiting thermal conductivity and excellent in foamability and flexibility can be produced.

  The foamed molded product and the thermally conductive molded product of the present invention are suitable as a member for constituting, for example, an electric / electronic device.

Claims (9)

(A-1) (A) a polymer component having a sea-island structure including a thermoplastic resin as a sea phase and (a-2) a rubber component as an island layer;
(B) a heat conductive filler,
The foaming molding whose content ratio of the said (B) heat conductive filler is 70-1000 volume parts with respect to 100 volume parts of said (a-1) thermoplastic resins.   The foam molded article according to claim 1, wherein the (B) thermally conductive filler is present at least in the sea phase.   The foam molded article according to claim 1 or 2, wherein the (a-1) thermoplastic resin is an α-olefin-based thermoplastic resin.   The foam molded article according to any one of claims 1 to 3, wherein the thermal conductivity of the (B) thermal conductive filler is 3 W / (m · K) or more.   The foam according to any one of claims 1 to 4, wherein the heat conductive filler (B) is at least one selected from the group consisting of metal oxides, metal hydroxides, nitrides, and silica powder. Molded body.   The number average cell diameter of the foamed cells formed in the foamed molded product is 10 to 200 µm, and the coefficient of variation (Cv) of the number average cell diameter is 0.1 to 1.0. The foamed molded product according to claim 1.   The manufacturing method of the heat conductive molded object which has the process of compressing the foaming molded object as described in any one of Claims 1-6 to 5 to 90% of a compression rate, and obtaining a heat conductive molded object.   The heat conductive molded object manufactured by the manufacturing method of the heat conductive molded object of Claim 7. A sheet comprising the thermally conductive molded body according to claim 8;
An adhesive layer disposed on one side of the sheet;
And a base material layer disposed on the other surface of the sheet.