JP2012144626A - Thermally conductive resin composition and thermally conductive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermally conductive resin composition with high formability and productivity, and exhibiting high thermal conductivity even when the percentage of an expensive thermally conductive inorganic filler is small; and to provide a thermally conductive sheet.SOLUTION: The thermally conductive resin composition contains a thermally conductive inorganic filler having an anisotropic shape, a heat resistant particle and a thermoplastic resin, wherein the heat resistant particle can hold the particle shape at the melting temperature of the thermoplastic resin. Preferably the heat resistant particle is talc or a crosslinked polyacrylic ester particle having the average particle size of 1-50 μm, and the thermal conductivity of 30 W/m K or lower. The thermally conductive inorganic filler is preferably a platy or fibrous electroconductive or insulative inorganic filler.

Description

  The present invention relates to a thermally conductive resin composition and a thermally conductive sheet that have thermal conductivity and are used for electrical and electronic devices.

  Thermoplastic resins are very flexible and can be easily processed by heating, so they are widely used in parts for electrical and electronic equipment. General-purpose thermoplastic resins are insulating and have thermal conductivity. Is also low. Therefore, in applications where thermal conductivity and conductivity are required, it is common to impart thermal conductivity and conductivity by using a composite material in combination with an inorganic filler. However, in such a composite material, when the proportion of the inorganic filler is increased in order to improve thermal conductivity and conductivity, the mechanical properties and moldability of the thermoplastic resin are lowered. Therefore, various composite materials have been proposed as composite materials for achieving both properties. In particular, since a plate-like inorganic filler such as boron nitride has a plate-like particle form, when thermoformed, the plate-like inorganic filler is arranged so that the plate surface is parallel to the flow direction of the resin in the forming. Further, it is known that boron nitride itself has extremely low thermal conductivity in the thickness direction as compared to the surface direction.

  For such a plate-like inorganic filler, a method for controlling the orientation in the resin has been proposed. For example, JP 2008-280496 A (Patent Document 1) discloses a molded body having a multilayer structure in which a plurality of sheets formed using thermally conductive non-spherical particles and an organic polymer compound are laminated to each other. A heat conductive sheet obtained by slicing the molded body at an angle of 0 to 30 degrees with respect to a normal line exiting from the main surface after forming is disclosed. Japanese Patent Application Laid-Open No. 2010-114421 (Patent Document 2) discloses a heat containing a composition containing a heat conductive inorganic material having a scale shape, an oval shape, a plate shape, or a rod shape, and an organic polymer compound. A conductive sheet, wherein the surface direction of the scale of the inorganic material, the long axis direction of the ellipsoid, the long axis direction of the plate, or the long axis direction of the rod are oriented to be inclined with respect to the thickness direction of the heat conductive sheet. A heat conductive sheet is disclosed.

  However, in these heat conductive sheets, the process for controlling the orientation direction of an inorganic material is complicated, and productivity is low.

  Japanese Patent No. 3568401 (Patent Document 3) discloses a <100> surface of an X-ray diffraction diagram obtained by irradiating X-rays in the thickness direction of a sheet in a thermally conductive sheet made of a resin sheet containing boron nitride. A high thermal conductivity sheet having a peak ratio (<002> / <100>) of <002> plane to 10 is disclosed. In this document, by passing a resin containing boron nitride through a plurality of small holes provided in a middle path in a die and extruding a plurality of rods, the rods are passed through a collection flat, Thermal conductivity is improved by distributing boron nitride in a state of being almost upright in the thickness direction of the sheet. Further, as the resin, a silicone resin, an epoxy resin, and an olefin resin are described, and in the examples, a silicone resin is used.

  However, even this high thermal conductive sheet has a complicated molding method and low productivity. Furthermore, when a curable resin is used as the binder resin, the curing process is required, and thus the moldability is lowered.

  Furthermore, in order to improve thermal conductivity, a method of blending other inorganic particles has also been proposed. For example, JP 2006-342192 A (Patent Document 4) uses a nanocomposite polyamide resin as a matrix resin. There is disclosed a molding resin that is electrically insulating and excellent in thermal conductivity obtained by highly blending a thermally conductive inorganic particulate filler. This document discloses a resin in which a layered silicate is dispersed at a molecular level in a polyamide resin matrix as a nanocomposite polyamide resin. Examples of the heat conductive inorganic particulate filler include alumina, magnesium oxide, silica, zinc oxide, boron nitride, silicon carbide, and silicon nitride. In the examples, spherical alumina is used. Furthermore, it is described that the addition amount of alumina is preferably 85 to 95% by weight.

  However, since this molding resin has a large proportion of thermally conductive inorganic particulate filler, moldability and mechanical properties are low. In particular, when spherical alumina is used, it is necessary to contain it at a high ratio in order to improve thermal conductivity.

  JP-A-3-200377 (Patent Document 5) discloses a heat dissipation sheet in which two types of thermally conductive fillers, a plate-like thermally conductive filler and a granular thermally conductive filler, are distributed in a matrix resin. The plate-like heat conductive filler is distributed in a multistage shape in the thickness direction with its plate surface along the longitudinal direction of the heat dissipation sheet, and the granular heat conductive filler is distributed in a multistage shape. A heat dissipating sheet that distributes mainly between layers of a thermally conductive filler is disclosed. In this document, boron nitride is described as the plate-like thermally conductive filler, and aluminum nitride is described as the granular thermally conductive filler. Moreover, the compounding ratio of the matrix resin and the two types of thermally conductive filler is described as 150 to 500 parts by weight of the two types of thermally conductive filler with respect to 100 parts by weight of the matrix resin. Furthermore, examples of the matrix resin include synthetic rubber, thermoplastic resin, and thermosetting resin. In the examples, silicone rubber is used.

  However, in this heat radiating sheet, since the ratio of the heat conductive filler is large, the moldability and mechanical properties are lowered, and the economy is low. Further, when rubber or thermosetting resin is used as the matrix resin, the moldability is also lowered.

JP-A-2008-280496 (Claims, Examples) JP 2010-114421 A (Claims, Examples) Japanese Patent No. 3568401 (claims, paragraphs [0011] [0018] [0021], Examples) JP 2006-342192 A (claims, paragraphs [0018] to [0022], examples) JP-A-3-200377 (claims, page 2, lower right column, lines 6 to 11, page 3, upper left column, example)

  Accordingly, an object of the present invention is to provide a thermally conductive resin composition and a thermally conductive sheet having high thermal conductivity even if the proportion of the expensive thermally conductive inorganic filler is small, with high moldability and productivity. There is to do.

  Another object of the present invention is to provide a thermally conductive resin composition and a thermally conductive sheet having high thermal conductivity and excellent mechanical properties.

  Still another object of the present invention is to provide a thermally conductive resin composition and a thermally conductive sheet that have insulating properties and high thermal conductivity.

  Another object of the present invention is to provide a thermally conductive resin composition and a thermally conductive sheet that are excellent in heat resistance and flexibility.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have improved the moldability and productivity of a resin composition by combining a thermally conductive inorganic filler having an anisotropic shape, heat-resistant particles, and a thermoplastic resin. It was found that the thermal conductivity could be improved even when the proportion of the expensive thermally conductive inorganic filler was small, and the present invention was completed.

  That is, the thermally conductive resin composition of the present invention is a thermally conductive resin composition comprising a thermally conductive inorganic filler having an anisotropic shape, heat resistant particles, and a thermoplastic resin, wherein the heat resistant particles are The particle shape can be maintained at the melting temperature of the thermoplastic resin. The heat-resistant particles may have an average particle diameter of 1 to 50 μm and a thermal conductivity of 30 W / m · K or less. The heat-resistant particles may be talc or crosslinked polyacrylate particles. The thermally conductive inorganic filler may be a plate-like or fibrous conductive or insulating inorganic filler (for example, boron nitride). The ratio (volume ratio) between the heat conductive inorganic filler and the heat-resistant particles may be about the former / the latter = 2/1 to 1/4. The thermoplastic resin may be at least one selected from the group consisting of polyamide resins, polyamide elastomers, and cyclic olefin elastomers. In the thermally conductive resin composition of the present invention, the proportion of the thermally conductive inorganic filler is 5 to 40% by volume with respect to the entire composition, and the thermal conductivity is 1 W / m · K or more. Good.

  The present invention also includes a heat conductive sheet composed of the heat conductive resin composition.

  In the present invention, by combining a thermally conductive inorganic filler having an anisotropic shape, heat resistant particles and a thermoplastic resin, the moldability and productivity of the resin composition can be improved, and the proportion of the expensive thermally conductive inorganic filler Even in a small amount, the thermal conductivity can be improved. Moreover, it has high thermal conductivity and excellent mechanical properties. For example, when an organic filler is used as the heat resistant particles, it is possible to suppress a decrease in flexibility and an increase in specific gravity. Further, by using an insulating inorganic filler such as boron nitride as the thermally conductive inorganic filler, not only the thermal conductivity but also the insulating property can be improved. Further, when a cyclic olefin-based elastomer is used as the thermoplastic resin, heat resistance and flexibility can be improved.

FIG. 1 is a graph showing the thermal conductivity of the sheets obtained in Comparative Examples 1 to 4 and Example 1. FIG. 2 is a graph showing the thermal conductivity of the sheets obtained in Examples 2-5. FIG. 3 is a graph showing the thermal conductivity of the sheets obtained in Comparative Example 5 and Examples 6-10. FIG. 4 is a graph showing the thermal conductivity of the sheets obtained in Examples 11-13. FIG. 5 is a graph showing the thermal conductivity of the sheets obtained in Example 6 and Examples 14-15. FIG. 6 is a graph showing the thermal conductivity of the sheets obtained in Comparative Examples 7-12 and Examples 16-19. FIG. 7 is a graph showing the thermal conductivity of the sheets obtained in Examples 25 and 26. FIG. 8 is a graph showing the thermal conductivity of the sheets obtained in Comparative Example 15 and Examples 27-29. FIG. 9 is a graph showing the hardness of the sheets obtained in Examples 16, 27 to 29 and Comparative Examples 7 to 10, 12, and 15.

[Thermal conductive resin composition]
The thermally conductive resin composition of the present invention includes a thermally conductive inorganic filler having an anisotropic shape, heat resistant particles, and a thermoplastic resin. In the thermally conductive resin composition of the present invention, the thermally conductive inorganic filler has high thermal conductivity, and the thermally conductive inorganic fillers intersect with each other due to the presence of the heat-resistant particles in the resin composition. (Or entangled) In order to form a heat conduction path or path (channel or path) by contacting, or even if the proportion of the thermally conductive inorganic filler is small, the thermal conductivity of the resin composition It can be improved. In particular, when the thermally conductive inorganic filler is a plate-like filler such as boron nitride, the plate surface of the filler is oriented in the flow direction of the thermoplastic resin during thermoforming, and the thermal conductivity in the thickness direction decreases. In the invention, the presence of the heat-resistant particles randomizes the orientation direction of the plate-like filler and also increases the contact area between the fillers, so that the thermal conductivity in the thickness direction can be improved.

(Thermal conductive inorganic filler)
The thermally conductive inorganic filler only needs to have an anisotropic shape and thermal conductivity, and the electrical characteristics can be selected depending on the application. Also good.

  Examples of the conductive inorganic filler include carbon materials (for example, artificial graphite, expanded graphite, natural graphite, coke, carbon nanotube, carbon fiber, etc.), simple metals or alloys (for example, metallic silicon, iron, copper, magnesium, aluminum). , Gold, platinum, zinc, manganese, stainless steel, etc.) and ceramics (eg, ferrite, tourmaline, diatomaceous earth, etc.). These conductive inorganic fillers can be used alone or in combination of two or more. Of these conductive inorganic fillers, carbon materials such as carbon nanotubes and carbon fibers and metal silicon are preferable because they are inexpensive and can effectively improve conductivity.

  Examples of the insulating inorganic filler include nitrogen compounds (boron nitride, aluminum nitride, carbon nitride, silicon nitride, etc.), carbon compounds (silicon carbide, fluorine carbide, boron carbide, tungsten carbide, diamond, etc.), metal oxides (oxidation) Magnesium, zinc oxide, beryllium oxide, etc.). These insulating inorganic fillers can be used alone or in combination of two or more. Of these insulating inorganic fillers, nitrogen compounds such as boron nitride and aluminum nitride are preferred, and boron nitride is particularly preferred from the viewpoint of excellent insulation and thermal conductivity. Boron nitride may be a hexagonal type having a structure similar to graphite or a cubic type having a diamond structure, but a hexagonal type is preferred.

  The shape of the heat conductive inorganic filler may be an anisotropic shape, and examples thereof include a plate shape (or scale shape), a rod shape, a fiber shape, and an indefinite shape. In the present invention, the orientation direction of the anisotropically shaped inorganic filler can be randomized by the presence of heat-resistant particles described later to improve the thermal conductivity in the thickness direction. Of these shapes, a plate shape, a scale shape, a rod shape or a fiber shape is preferable, and a plate shape (or a scale shape) is particularly preferable from the viewpoint that the thermal conductivity can be improved by efficiently contacting in the gap between the heat resistant particles. .

  The average particle diameter of the thermally conductive inorganic filler can be appropriately selected from a range of about 0.1 to 100 μm, and is, for example, 1 to 50 μm, preferably 3 to 40 μm (for example, 5 to 30 μm), more preferably 10 to 25 μm ( In particular, it is about 15 to 20 μm. This average particle diameter may be the average diameter of the plate surface (added average diameter of the major axis and the minor axis on the plate surface) when the inorganic filler is plate-shaped. In the present invention, the larger the particle size of the inorganic filler can be uniformly dispersed, the larger the thermal conductivity can be improved. Furthermore, when it is plate-like, the aspect ratio (average diameter / thickness of the plate surface) of the average diameter and thickness of the plate surface is, for example, 2 or more, preferably 2 to 50, more preferably 3 to 30 (especially About 5-20) may be sufficient. When the inorganic filler is fibrous, the average fiber length of the fibers may be in the range of the particle diameter. However, in the case of carbon nanotubes, the average fiber length is, for example, 0.1 to 100 μm, preferably 1 to 50 μm. More preferably, it may be about 2 to 10 μm.

  The weight ratio of the thermally conductive inorganic filler may be, for example, 6 to 70 parts by weight, preferably 10 to 60 parts by weight, and more preferably about 20 to 55 parts by weight with respect to 100 parts by weight of the thermoplastic resin. .

  The volume ratio of the heat conductive inorganic filler can be selected from the range of about 1 to 80% by volume with respect to the entire resin composition, and is, for example, 3 to 50% by volume, preferably 5 to 40% by volume, and more preferably 10 to 10% by volume. It is about 35% by volume (particularly 20 to 35% by volume). In particular, by adjusting the proportion of the thermally conductive inorganic filler to about 5 to 40% by volume, for example, the thermal conductivity can be improved to 1 W / m · K or more.

  The heat conductive inorganic filler may be combined with an isotropic heat conductive inorganic filler (for example, spherical alumina particles, carbon black, etc.) as long as the effects of the present invention are not impaired. The ratio of the isotropic thermally conductive inorganic filler is about 200 parts by weight or less, preferably about 100 parts by weight or less with respect to 100 parts by weight of the anisotropically shaped thermally conductive inorganic filler.

(Heat resistant particles)
Any heat-resistant particles may be used as long as the shape of the particles can be maintained at the melting temperature of the thermoplastic resin. Furthermore, in the present invention, even when the heat-resistant particles do not have high thermal conductivity, high thermal conductivity can be expressed by a combination with the thermal conductive inorganic filler.

  The heat conductivity of the heat-resistant particles may be 30 W / m · K or less, for example, 0.1 to 25 W / m · K, preferably 1 to 20 W / m · K, more preferably 2 to 15 W / m. -About K (especially 3-12W / m * K) may be sufficient.

  The heat-resistant particles having such thermal conductivity may be either inorganic particles or organic particles. Examples of the inorganic compound constituting the inorganic particles include minerals or ceramics (talc, mica, zeolite, diatomaceous earth, calcined siliceous earth, kaolin, sericite, bentonite, smectite, clay, silica, alumina, quartz powder, and glass. Beads, glass powder, glass flakes, milled fiber, wollastonite, etc.), nitrogen compounds (such as titanium nitride), carbon compounds (such as titanium carbide), metal oxides (such as silica, alumina, zirconia), metal hydroxides (such as And aluminum carbonate, calcium hydroxide, magnesium hydroxide, etc.) and carbonates (magnesium carbonate, calcium carbonate, etc.). Examples of organic compounds constituting the organic particles include crosslinked thermoplastic resins (crosslinked acrylic resins such as crosslinked polymethyl methacrylate and crosslinked acrylate esters, crosslinked styrene resins such as crosslinked polystyrene), thermosetting resins ( Phenol resin, melamine resin, urea resin, benzoguanamine resin, silicone resin, epoxy resin, vinyl ester resin, polyurethane resin, etc.), rubber (polybutadiene, polyisoprene, styrene-butadiene rubber and other diene rubbers, ethylene-propylene rubber, ethylene -Vinyl acetate rubber-like copolymer, butyl rubber, nitrile rubber, chlorosulfonated polyethylene, epichlorohydrin rubber, polysulfide rubber, acrylic rubber, urethane rubber, silicone rubber, fluorine rubber, etc.). These heat-resistant particles can be used alone or in combination of two or more.

  Of these heat-resistant particles, particles composed of minerals or ceramics such as talc and mica, crosslinked thermoplastic resins such as crosslinked polystyrene, crosslinked polymethyl methacrylate, and crosslinked polyacrylate are widely used. Particles composed of a silicate such as mica (particularly talc) and crosslinked acrylic resin particles (particularly crosslinked polyacrylate particles) are preferred.

The polyacrylic acid ester constituting the crosslinked polyacrylic acid ester particles is mainly composed of C _1-8 alkyl polyacrylate (particularly C _2-6 alkyl) such as polyethyl acrylate and butyl polyacrylate. And polyacrylic acid alkyl ester having a weight percent, preferably about 70 to 100 weight percent). As the crosslinking agent, a conventional crosslinking agent can be used. For example, a compound having two or more ethylenically unsaturated bonds ((poly) C ₂₋ such as ethylene glycol di (meth) acrylate and polyethylene glycol di (meth) acrylate) is used. ₁₀ alkylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, divinylbenzene, etc.) can be used. The proportion of the crosslinking agent may be about 0.1 to 10 mol% (particularly 1 to 10 mol%) of all monomers. When crosslinked polyacrylate particles are used, a resin composition having high flexibility and low specific gravity can be prepared. The effect of improving flexibility is large when the proportion of the thermally conductive inorganic filler is small (for example, 20% by volume or less with respect to the entire resin composition), but is used at a high temperature (80 ° C. or higher, for example, 100 to 100%). For example, at about 140 ° C., even if the proportion of the thermally conductive inorganic filler is large, the flexibility can be improved by the crosslinked polyacrylate particles.

  Examples of the shape of the heat-resistant particles include a spherical shape, an ellipsoidal shape, a polygonal shape (polygonal pyramid shape, a rectangular parallelepiped shape, a rectangular parallelepiped shape, etc.), a plate shape (or a scale shape), a rod shape, a fiber shape, and an indefinite shape. Among these shapes, a substantially spherical shape, an ellipsoid shape, a polygonal shape, a plate shape, and the like are preferable because the orientation direction of the thermally conductive inorganic filler having an anisotropic shape can be easily randomized.

  The average particle diameter of the heat-resistant particles (in the case of plate-like particles, the average diameter of the plate surface) can be selected from the range of about 0.1 to 100 μm. For example, if it is about 1 to 50 μm, regardless of the size of the diameter The thermal conductivity can be improved, but from the viewpoint of ease of handling and dispersibility, it may be, for example, about 3 to 45 μm, preferably 5 to 40 μm, more preferably about 10 to 35 μm (particularly 20 to 30 μm).

  The ratio of the average particle diameter of the heat conductive inorganic filler and the heat-resistant particles is not particularly limited, but can be selected, for example, from the range of the former / the latter = 10/1 to 1/10, and preferably 2/1 to 1 / 5, more preferably about 1/1 to 1/3 (particularly 1 / 1.2-1 / 2).

  The ratio (volume ratio) between the thermally conductive inorganic filler and the heat-resistant particles can be selected from the range of the former / the latter = 10/1 to 1/10, for example, 3/1 to 1/5, preferably 2 / It is about 1 to 1/4, more preferably about 1/1 to 1/3 (particularly 1 / 1.5-1 to 2.5). In the present invention, by combining the heat-resistant particles and the heat conductive inorganic filler, the heat conductivity of the resin composition can be effectively improved despite the low heat conductivity of the heat-resistant particles themselves. When talc about 1.5 to 2.5 times the conductive inorganic filler is used, a thermal conductivity of about 3 W / m · K is obtained. Therefore, in this invention, even if it is a mixing | blending of a small amount of heat conductive inorganic fillers, heat conductivity can be improved.

  The weight ratio of the heat-resistant particles may be, for example, about 50 to 350 parts by weight, preferably 80 to 300 parts by weight, and more preferably about 100 to 280 parts by weight with respect to 100 parts by weight of the thermoplastic resin.

(Thermoplastic resin)
Examples of the thermoplastic resin include olefin resins, (meth) acrylic resins, styrene resins, fatty acid vinyl ester resins, polyester resins, polyamide resins, polyamideimide resins, polyacetal resins, polycarbonate resins, Examples include polysulfone resins, polyphenylene ether resins, thermoplastic polyurethane resins, thermoplastic elastomers (polyolefin elastomers, polystyrene elastomers, polyester elastomers, polyamide elastomers, polyurethane elastomers, etc.), cellulose derivatives, and the like. These thermoplastic resins can be used alone or in combination of two or more.

  These thermoplastic resins can be selected according to the use. For example, in the use of electrical and electronic parts, from the viewpoint of excellent heat resistance and flexibility, polyamide resins, polyamide elastomers, and cyclic olefin elastomers may be used. Good.

Examples of polyamide resins include aliphatic polyamides such as polyamide 46, polyamide 6, polyamide 66, polyamide 610, polyamide 612, polyamide 11 and polyamide 12, dicarboxylic acids (eg terephthalic acid, isophthalic acid, adipic acid, etc.) Examples thereof include polyamides obtained from diamines (for example, hexamethylenediamine, metaxylylenediamine). These polyamides are not limited to homopolyamides and may be copolyamides. These polyamide resins can be used alone or in combination of two or more. Of these polyamide resins, aliphatic polyamides having C _8-16 alkylene chains (particularly aliphatic polyamides having C _10-14 alkylene chains such as polyamide 11 and polyamide 12) are particularly preferred.

Examples of the polyamide-based elastomer include a polyamide-polyether block copolymer having a polyamide unit exemplified by the polyamide-based resin as a hard segment and a polyether unit as a soft segment. In such a block copolymer, the polyamide unit includes an aliphatic polyamide unit having a C _8-16 alkylene chain (particularly, an aliphatic polyamide unit having a C _10-14 alkylene chain such as polyamide 11 or polyamide 12). preferable. The polyether unit is preferably a poly C _2-4 alkylene oxide unit such as polytetramethylene oxide, polyethylene oxide, or polypropylene oxide. The ratio (weight ratio) between the hard segment and the soft segment is not particularly limited, and can be selected from a range of about hard segment / soft segment = 99/1 to 1/99. Is preferable, for example, hard segment / soft segment = 50/50 to 1/99, preferably 40/60 to 5/95, and more preferably about 30/70 to 10/90. .

As the cyclic olefin-based elastomer, the ratio (molar ratio) of the chain olefin to the cyclic olefin in the chain olefin-cyclic olefin copolymer is a chain olefin / cyclic olefin = 80/20 to 99/1, preferably Is a copolymer of about 85/15 to 97/3, more preferably about 90/10 to 95/5. Examples of the chain olefin include chain structures such as ethylene, propylene, 1-butene, isobutene, 1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 1-hexene and 1-octene. And C _2-10 olefins. Examples of the cyclic olefin include norbornene (2-norbornene), norbornene having a substituent (such as an alkyl group, an alkenyl group, and an aryl group), a cyclopentadiene multimer, and a cyclopentadiene multimer having the substituent. It is done. The chain olefin-cyclic olefin copolymer is in a proportion of 5 mol% or less (particularly 1 mol% or less) with respect to the copolymer, and other copolymerizable monomers such as diene monomers (butadienes). , Isoprene and the like) and aromatic vinyl monomers (styrene and the like). These cyclic olefin-based elastomers can be used alone or in combination of two or more. Among these cyclic olefin elastomers, a copolymer of an α-chain C _2-4 olefin such as ethylene and a polycyclic olefin such as norbornene is preferable.

The thermally conductive resin composition of the present invention may contain a lubricant or a plasticizer in order to improve the fluidity of the thermoplastic resin. Examples of the lubricant or plasticizer include waxes (poly C _2-4 olefin wax such as polyethylene wax, paraffin wax, vegetable or animal wax such as montan wax, etc.), lipids (laurin). acid, palmitic acid, _{C 8-35} saturated fatty acids, _{C 8-35} saturated fatty acid metal salts such as calcium stearate and magnesium stearate, pentaerythritol _{C 8-35} saturated fatty acid esters such as pentaerythritol monostearate, such as stearic acid, Alkylene bis-fatty acid amides such as ethylene bis-stearic acid amide), phthalic acid esters (such as dibutyl phthalate, dioctyl phthalate), phosphoric acid esters (such as tricresyl phosphate, trioctyl phosphate), fat Group polycarboxylic esters (dioctyl adipate, dioctyl sebacate, etc.), epoxy compounds (alkyl epoxy stearate, epoxidized soybean oil, etc.) and the like. These lubricants or plasticizers can be used alone or in combination of two or more.

  The ratio of the lubricant or the plasticizer can be selected from the range of about 0.01 to 100 parts by weight with respect to 100 parts by weight of the thermoplastic resin, for example, 0.1 to 30 parts by weight, preferably 0.3 to 10 parts by weight, More preferably, it may be about 0.5 to 5 parts by weight.

  In the thermally conductive resin composition of the present invention, a conventional flame retardant (for example, a phosphorus-based flame retardant such as red phosphorus or an aromatic phosphate, a halogen-based flame retardant, or the like) is used to improve the flame retardancy. It may be included. The ratio of the flame retardant may be, for example, 1 to 100 parts by weight, preferably 1 to 50 parts by weight, and more preferably about 5 to 30 parts by weight with respect to 100 parts by weight of the thermoplastic resin.

  The heat conductivity of the heat conductive resin composition of the present invention may be 1 W / m · K or more, for example, 1 to 5 W / m · K, preferably 1.5 to 4.8 W / m · K, More preferably, it may be about 2 to 4.5 W / m · K (particularly 2.5 to 4 W / m · K).

  The thermally conductive resin composition of the present invention further contains conventional additives such as stabilizers (thermal stabilizers, ultraviolet absorbers, light stabilizers, antioxidants, etc.), dispersants, antistatic agents, and colorants. And may contain a lubricant and the like. These additives can be used alone or in combination of two or more.

[Thermal conductive sheet and manufacturing method thereof]
The heat conductive sheet of this invention is comprised with the said heat conductive resin composition. The heat conductive sheet of the present invention comprises the above-mentioned heat conductive inorganic filler, heat resistant particles, thermoplastic resin, and if necessary, a component such as a lubricant, if necessary, a conventional method (for example, melt blending method, tumbler method, etc.) In addition to blending, melting and mixing, extruding from a T-die or ring die, etc. to form a film, injection molding, blow molding, vacuum molding, profile molding, injection press, press molding, gas injection It can be molded by a molding method, a compression molding method, a transfer molding method, or the like. Furthermore, it may be formed by using a conventional film forming method such as a coating method in which a liquid composition containing the above components is applied on a substrate, a laminating method in which the composition is laminated, or a casting method.

  The thickness of a heat conductive sheet can be selected according to a use, for example, can be selected from the range of about 10-3000 micrometers, for example, 20-2000 micrometers, Preferably it is 30-1000 micrometers, More preferably, it is 40-500 micrometers (especially 50-300 micrometers). )

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In addition, the heat conductivity of the heat conductive sheet obtained in the Example was measured with the following method.

(Thermal conductivity)
The thermal diffusivity in the thickness direction of the film was measured using a laser flash thermal conductivity measuring apparatus (manufactured by NETZSCH), and the thermal conductivity was determined based on the following formula.

Thermal conductivity (W / m · K) = density (g / cm ³ ) × specific heat (J / kg · K) × thermal diffusivity (mm ² / s).

(hardness)
Based on JIS K6253, it measured with the type A durometer (spring type rubber hardness meter).

Comparative Example 1
(Production of ethylene-norbornene copolymer)
In a nitrogen atmosphere at room temperature, 30 liters of autoclave were charged with 15 liters of toluene, 15 mmol of triisobutylaluminum (TIBA), 0.75 mmol of zirconium tetrachloride, and 0.75 mmol of tetrakis (pentafluorophenyl) anilinium borate in this order. Subsequently, 1.8 liters of a toluene solution containing 70% by weight of norbornene was added. After raising the temperature to 50 ° C., the reaction was carried out for 60 minutes while continuously introducing ethylene so that the ethylene partial pressure was 5 kgf / cm ² . After completion of the reaction, the polymer solution was put into 15 liters of methanol to precipitate a polymer. The polymer was separated by filtration and dried to obtain an ethylene-norbornene copolymer. The yield was 3.12 kg, and the polymerization activity was 46 kg / g Zr (yield per gram of zirconium).

^{In 13} C-NMR, the sum of the peak based on the ethylene unit and the peak based on the 5th and 6th position methylenes of the norbornene unit (around 30 ppm) and the peak based on the 7th position methylene group of the norbornene unit (around 32.5 ppm) The norbornene content determined from the ratio was 8.6 mol%. The glass transition temperature was -1 ° C, the melting point was 80 ° C, and the crystallinity was 10%.

(Manufacture of heat conductive sheet)
100 parts by weight of the obtained ethylene-norbornene copolymer was charged into a lab plast mill (manufactured by Toyo Seiki Seisakusho Co., Ltd.) and kneaded at a temperature of 200 ° C. for 3 minutes to obtain a resin composition. Using the compression molding press (“Mini Test Press-10” manufactured by Toyo Seiki Seisakusho Co., Ltd.), the resulting resin composition was pressurized at 200 ° C. and a gauge pressure of 30 MPa for 2 minutes, and the thickness was about 3 mm. The resin sheet was molded. The obtained sheet had a thermal conductivity of 0.26 W / m · K.

Comparative Example 2
A thermal conductive sheet was prepared in the same manner as in Comparative Example 1, except that 66 parts by weight of boron nitride (“GP” manufactured by Electrochemical Co., Ltd., average particle size: 8 μm) was further added to 100 parts by weight of the ethylene-norbornene copolymer. Was molded. In the sheet, the volume ratio of boron nitride was 21% by volume. The obtained sheet had a thermal conductivity of 0.61 W / m · K.

Comparative Example 3
A heat conductive sheet was prepared in the same manner as in Comparative Example 1, except that 117 parts by weight of boron nitride (“GP” manufactured by Electrochemical Co., Ltd., average particle size: 8 μm) was further added to 100 parts by weight of the ethylene-norbornene copolymer. Was molded. In the sheet, the volume ratio of boron nitride was 32% by volume. The obtained sheet had a thermal conductivity of 1.47 W / m · K.

Comparative Example 4
A thermal conductive sheet was prepared in the same manner as in Comparative Example 1 except that 188 parts by weight of boron nitride (“GP” manufactured by Electrochemical Co., Ltd., average particle size: 8 μm) was further added to 100 parts by weight of the ethylene-norbornene copolymer. Was molded. In the sheet, the volume ratio of boron nitride was 43% by volume. The obtained sheet had a thermal conductivity of 2.30 W / m · K.

Example 1
For 100 parts by weight of the obtained ethylene-norbornene copolymer, further 92 parts by weight of boron nitride (“GP” manufactured by Electrochemical Co., Ltd., average particle size 8 μm), talc (“P-” manufactured by Nippon Talc Co., Ltd.) 4 ”, average particle size 4.5 μm) A thermally conductive sheet was molded in the same manner as Comparative Example 1 except that 104 parts by weight were charged. In the sheet, the volume ratio of boron nitride was 22% by volume, and the volume ratio of talc was 21% by volume. The obtained sheet had a thermal conductivity of 1.95 W / m · K.

  The evaluation results of Comparative Examples 1 to 4 and Example 1 are shown in the graph of FIG. As is clear from FIG. 1, in Example 1, the thermal conductivity is low compared to Comparative Examples 1 to 4, and it can be seen that the thermal conductivity is effectively improved by blending inexpensive talc.

Example 2
100 parts by weight of polyamide 12 (“ZZ3000P” manufactured by Daicel Evonik Co., Ltd.), 88 parts by weight of boron nitride (“GP” manufactured by Electrochemical Co., Ltd., average particle size 8 μm), and “P” manufactured by Talc (Nippon Talc Co., Ltd.) -4 ", average particle size 4.5 μm) 98 parts by weight were charged into a lab plast mill (manufactured by Toyo Seiki Seisakusho Co., Ltd.) and kneaded at 200 ° C. for 3 minutes to obtain a resin composition. Using the compression molding press (“Mini Test Press-10” manufactured by Toyo Seiki Seisakusho Co., Ltd.), the resulting resin composition was pressurized at 200 ° C. and a gauge pressure of 30 MPa for 2 minutes, and the thickness was about 3 mm. The resin sheet was molded. In the sheet, the volume ratio of boron nitride was 21% by volume, and the volume ratio of talc was also 21% by volume. The obtained sheet had a thermal conductivity of 1.62 W / m · K.

Example 3
For 100 parts by weight of polyamide 12 (“ZZ3000P” manufactured by Daicel Evonik Co., Ltd.), 139 parts by weight of boron nitride (“GP” manufactured by Electrochemical Co., Ltd., average particle size 8 μm), talc (Nippon Talc Co., Ltd.) A thermally conductive sheet was formed in the same manner as in Example 2 except that 114 parts by weight of “P-4” (average particle size: 4.5 μm) was charged. In the sheet, the volume ratio of boron nitride was 30% by volume, and the volume ratio of talc was also 21% by volume. The obtained sheet had a thermal conductivity of 2.39 W / m · K.

Example 4
For 100 parts by weight of polyamide 12 (“ZZ3000P” manufactured by Daicel Evonik Co., Ltd.), 234 parts by weight of boron nitride (“GP” manufactured by Electrochemical Co., Ltd., average particle size 8 μm), talc (Nihon Talc Co., Ltd.) A thermally conductive sheet was formed in the same manner as in Example 2 except that 144 parts by weight of “P-4” (average particle size: 4.5 μm) was charged. In the sheet, the volume ratio of boron nitride was 40% by volume, and the volume ratio of talc was 21% by volume. The obtained sheet had a thermal conductivity of 2.83 W / m · K.

Example 5
For 100 parts by weight of polyamide 12 (“ZZ3000P” manufactured by Daicel Evonik Co., Ltd.), 233 parts by weight of boron nitride (“GP” manufactured by Electrochemical Co., Ltd., average particle size 8 μm), talc (Nippon Talc Co., Ltd.) A thermally conductive sheet was formed in the same manner as in Example 2 except that 144 parts by weight (manufactured “MS-KY”, average particle size 27 μm) was charged. In the sheet, the volume ratio of boron nitride was 40% by volume, and the volume ratio of talc was 21% by volume. The obtained sheet had a thermal conductivity of 3.30 W / m · K.

  The evaluation results of Examples 2 to 5 are shown in the graph of FIG. In FIG. 2, the results of Comparative Examples 1 to 4 are also shown for comparison. As is clear from FIG. 2, the sheet of the example has high thermal conductivity. For example, the thermal conductivity of Example 3 is 43% of boron nitride even though the boron nitride ratio is 30% by volume. The heat conductivity equivalent to the comparative example 4 mix | blended by volume% is shown.

Comparative Example 5
Labo Plast Mill (Toyo Seiki Seisakusyo) Co., Ltd. 100 parts by weight of polyamide 12 (“ZZ3000P” manufactured by Daicel Evonik Co., Ltd.) and 64 parts by weight of boron nitride (“GP” manufactured by Electrochemical Co., Ltd., average particle size: 8 μm) And kneaded at a temperature of 200 ° C. for 3 minutes to obtain a resin composition. Using the compression molding press (“Mini Test Press-10” manufactured by Toyo Seiki Seisakusho Co., Ltd.), the resulting resin composition was pressurized at 200 ° C. and a gauge pressure of 30 MPa for 2 minutes, and the thickness was about 3 mm. The resin sheet was molded. In the sheet, the volume ratio of boron nitride was 21% by volume. The obtained sheet had a thermal conductivity of 0.54 W / m · K.

Example 6
Compared to 100 parts by weight of polyamide 12 (“ZZ3000P” manufactured by Daicel Evonik Co., Ltd.), except that 99 parts by weight of talc (“FG-15” manufactured by Nippon Talc Co., Ltd., average particle size: 1.6 μm) is charged. A heat conductive sheet was formed in the same manner as in Example 5. In the sheet, the volume ratio of boron nitride was 21% by volume, and the volume ratio of talc was also 21% by volume. The obtained sheet had a thermal conductivity of 1.45 W / m · K.

Example 7 (same experiment as Example 2)
Compared to 100 parts by weight of polyamide 12 (“ZZ3000P” manufactured by Daicel Evonik Co., Ltd.), except that 99 parts by weight of talc (“P-4” manufactured by Nippon Talc Co., Ltd., average particle size: 4.5 μm) is charged. A heat conductive sheet was formed in the same manner as in Example 5. In the sheet, the volume ratio of boron nitride was 21% by volume, and the volume ratio of talc was also 21% by volume. The obtained sheet had a thermal conductivity of 1.62 W / m · K.

Example 8
Comparative Example 5 except that 99 parts by weight of talc (“K-1” manufactured by Nippon Talc Co., Ltd., average particle size: 8 μm) was further added to 100 parts by weight of polyamide 12 (“ZZ3000P” manufactured by Daicel Evonik Co., Ltd.). In the same manner, a heat conductive sheet was formed. In the sheet, the volume ratio of boron nitride was 21% by volume, and the volume ratio of talc was also 21% by volume. The obtained sheet had a thermal conductivity of 1.72 W / m · K.

Example 9
Comparative Example 5 except that 99 parts by weight of talc (“MSG” manufactured by Nippon Talc Co., Ltd., average particle size 10.5 μm) was further added to 100 parts by weight of polyamide 12 (“ZZ3000P” manufactured by Daicel Evonik Co., Ltd.). In the same manner, a heat conductive sheet was formed. In the sheet, the volume ratio of boron nitride was 21% by volume, and the volume ratio of talc was also 21% by volume. The obtained sheet had a thermal conductivity of 1.63 W / m · K.

Example 10
Comparative Example 5 except that 99 parts by weight of talc (“MS-KY” manufactured by Nippon Talc Co., Ltd., average particle size 27 μm) was further added to 100 parts by weight of polyamide 12 (“ZZ3000P” manufactured by Daicel Evonik Co., Ltd.). In the same manner, a heat conductive sheet was formed. In the sheet, the volume ratio of boron nitride was 21% by volume, and the volume ratio of talc was also 21% by volume. The obtained sheet had a thermal conductivity of 1.63 W / m · K.

  The evaluation results of Comparative Example 5 and Examples 6 to 10 are shown in the graph of FIG. As can be seen from FIG. 3, the sheets of the examples all have higher thermal conductivity than the sheets of the comparative examples, and the influence of the particle size of talc is small.

Example 11 (same experiment as Example 2)
Compared to 100 parts by weight of polyamide 12 (“ZZ3000P” manufactured by Daicel Evonik Co., Ltd.), except that 99 parts by weight of talc (“P-4” manufactured by Nippon Talc Co., Ltd., average particle size: 4.5 μm) is charged. A heat conductive sheet was formed in the same manner as in Example 5. In the sheet, the volume ratio of boron nitride was 21% by volume, and the volume ratio of talc was also 21% by volume. The obtained sheet had a thermal conductivity of 1.62 W / m · K.

Example 12
Compared to 100 parts by weight of polyamide 12 (“ZZ3000P” manufactured by Daicel Evonik Co., Ltd.), except that 167 parts by weight of talc (“P-4” manufactured by Nippon Talc Co., Ltd., average particle size: 4.5 μm) is charged. A heat conductive sheet was formed in the same manner as in Example 5. In the sheet, the volume ratio of boron nitride was 21% by volume, and the volume ratio of talc was 30% by volume. The obtained sheet had a thermal conductivity of 2.47 W / m · K.

Example 13
Compared to 100 parts by weight of polyamide 12 (“ZZ3000P” manufactured by Daicel Evonik Co., Ltd.), except that 281 parts by weight of talc (“P-4” manufactured by Nippon Talc Co., Ltd., average particle size: 4.5 μm) is charged. A heat conductive sheet was formed in the same manner as in Example 5. In the sheet, the volume ratio of boron nitride was 21% by volume, and the volume ratio of talc was 40% by volume. The obtained sheet had a thermal conductivity of 2.24 W / m · K.

  The evaluation result of Examples 11-13 is shown in the graph of FIG. FIG. 4 also shows the results of Comparative Example 5 for comparison. As is clear from FIG. 4, the thermal conductivity increased as the talc ratio increased.

Comparative Example 6
100 parts by weight of polyamide 12 (“ZZ3000P” manufactured by Daicel Evonik) and 59 parts by weight of carbon nanotubes (“VGCF-H” manufactured by Showa Denko KK, average fiber diameter 150 nm, average fiber length 6 μm) A resin composition was obtained by charging into a mill (manufactured by Toyo Seiki Seisakusho Co., Ltd.) and kneading at 200 ° C. for 3 minutes. Using the compression molding press machine ("Mini Test Press-10" manufactured by Toyo Seiki Seisakusho Co., Ltd.), the obtained resin composition was pressed at 220 ° C and a gauge pressure of 30 MPa for 2 minutes, and the thickness was about 3 mm. The resin sheet was molded. In the sheet, the volume ratio of carbon nanotubes was 22% by volume. The obtained sheet had a thermal conductivity of 2.03 W / m · K.

Example 14
Compared to 100 parts by weight of polyamide 12 (“ZZ3000P” manufactured by Daicel Evonik Co., Ltd.), except that 99 parts by weight of talc (“P-4” manufactured by Nippon Talc Co., Ltd., average particle size: 4.5 μm) is charged. A heat conductive sheet was formed in the same manner as in Example 6. In the sheet, the volume ratio of carbon nanotubes was 22% by volume, and the volume ratio of talc was 22% by volume. The obtained sheet had a thermal conductivity of 3.67 W / m · K.

Example 15
Comparative Example 6 except that 99 parts by weight of talc (“MS-KY” manufactured by Nippon Talc Co., Ltd., average particle size 27 μm) was further added to 100 parts by weight of polyamide 12 (“ZZ3000P” manufactured by Daicel Evonik Co., Ltd.). In the same manner, a heat conductive sheet was formed. In the sheet, the volume ratio of carbon nanotubes was 22% by volume, and the volume ratio of talc was 22% by volume. The obtained sheet had a thermal conductivity of 3.50 W / m · K.

  The evaluation results of Comparative Example 6 and Examples 14 to 15 are shown in the graph of FIG. For comparison, FIG. 5 also shows the results of Comparative Example 5 and Examples 11 to 13 to which boron nitride was added. As is clear from FIG. 5, the use of carbon nanotubes instead of boron nitride improved the thermal conductivity.

Comparative Example 7
100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.) was charged into a Laboplast Mill (manufactured by Toyo Seiki Seisakusho Co., Ltd.) and kneaded at a temperature of 200 ° C. for 3 minutes to obtain a resin composition. Obtained. Using the compression molding press (“Mini Test Press-10” manufactured by Toyo Seiki Seisakusho Co., Ltd.), the resulting resin composition was pressurized at 200 ° C. and a gauge pressure of 30 MPa for 2 minutes, and the thickness was about 3 mm. The resin sheet was molded. The obtained sheet had a thermal conductivity of 0.24 W / m · K.

Comparative Example 8
Except for adding 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.) and 57 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size: 18 μm). A heat conductive sheet was formed in the same manner as in Comparative Example 7. In the sheet, the volume ratio of boron nitride was 20% by volume. The obtained sheet had a thermal conductivity of 0.55 W / m · K.

Comparative Example 9
Except for adding 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.) and 112 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size: 18 μm). A heat conductive sheet was formed in the same manner as in Comparative Example 7. In the sheet, the volume ratio of boron nitride was 33% by volume. The obtained sheet had a thermal conductivity of 1.97 W / m · K.

Comparative Example 10
Except for adding 186 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size 18 μm) to 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.) A heat conductive sheet was formed in the same manner as in Comparative Example 7. In the sheet, the volume ratio of boron nitride was 44% by volume. The obtained sheet had a thermal conductivity of 2.26 W / m · K.

Comparative Example 11
Except for adding 341 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size 18 μm) to 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.) A heat conductive sheet was formed in the same manner as in Comparative Example 7. In the sheet, the volume ratio of boron nitride was 60% by volume. The obtained sheet had a thermal conductivity of 4.50 W / m · K.

Comparative Example 12
Other than charging 178 parts by weight of talc (“MS-KY” manufactured by Nippon Talc Co., Ltd., average particle size 27 μm) with respect to 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.) Were molded in the same manner as in Comparative Example 7. In the sheet, the volume ratio of talc was 40% by volume. The obtained sheet had a thermal conductivity of 1.13 W / m · K.

Example 16
In addition to 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.), 114 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size 18 μm), talc (Japan) A heat conductive sheet was molded in the same manner as Comparative Example 7 except that 267 parts by weight of “MS-KY” manufactured by Talc Co., Ltd., having an average particle size of 27 μm) was charged. In the sheet, the volume ratio of boron nitride was 20% by volume, and the volume ratio of talc was 40% by volume. The obtained sheet had a thermal conductivity of 2.83 W / m · K.

Example 17
In addition to 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.), 152 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size 18 μm), talc (Japan) A thermally conductive sheet was molded in the same manner as Comparative Example 7 except that 447 parts by weight of “MS-KY” manufactured by Talc Co., Ltd., having an average particle size of 27 μm) was charged. In the sheet, the volume ratio of boron nitride was 20% by volume, and the volume ratio of talc was 50% by volume. The obtained sheet had a thermal conductivity of 3.07 W / m · K.

Example 18
To 100 parts by weight of a polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.), 114 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size: 18 μm), crosslinked polymethacrylic A thermally conductive sheet was formed in the same manner as in Comparative Example 7 except that 119 parts by weight of methyl acid (PMMA) particles (“Techpolymer MBX-50” manufactured by Sekisui Plastics Co., Ltd., average particle size: 50 μm) were charged. In the sheet, the volume ratio of boron nitride was 20% by volume, and the volume ratio of crosslinked PMMA particles was 40% by volume. The obtained sheet had a thermal conductivity of 1.45 W / m · K.

Example 19
Further, 594 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size 18 μm), 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.), crosslinked polymethacryl A thermally conductive sheet was molded in the same manner as in Comparative Example 7 except that 340 parts by weight of methyl acid (PMMA) particles (“Techpolymer MBX-50” manufactured by Sekisui Plastics Co., Ltd., average particle size 50 μm) were charged. In the sheet, the volume ratio of boron nitride was 20% by volume, and the volume ratio of crosslinked PMMA particles was 67% by volume. The obtained sheet had a thermal conductivity of 1.56 W / m · K.

  The evaluation results of Comparative Examples 7 to 12 and Examples 16 to 19 are shown in the graph of FIG. As is clear from FIG. 6, the thermal conductivity was improved by the addition of the crosslinked PMMA particles, but the improvement rate was smaller than that of talc.

Comparative Example 13
For 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.), 118 parts by weight of spherical alumina particles (“DAW45” manufactured by Electrochemical Co., Ltd., average particle size 45 μm), spherical alumina Comparative Example 7 except that 79 parts by weight of particles (“DAW03” manufactured by Electrochemical Co., Ltd., average particle size 3 μm) and 263 parts by weight of talc (“MS-KY” manufactured by Nippon Talc Co., Ltd., average particle size 27 μm) were charged. In the same manner, a heat conductive sheet was formed. In the sheet, the total volume ratio of the spherical alumina particles was 20% by volume, and the volume ratio of talc was 40% by volume. The obtained sheet had a thermal conductivity of 2.07 W / m · K. Compared with Example 15 which mix | blended the same quantity boron nitride and talc, thermal conductivity fell.

Example 20
To 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.), 103 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size 18 μm), boron nitride ( Comparative Example 7 except that 12 parts by weight of “SP-3” manufactured by Electrochemical Co., Ltd. and an average particle size of 3 μm were charged and 267 parts by weight of talc (“MS-KY” manufactured by Nippon Talc Co., Ltd., average particle size of 27 μm) were charged. In the same manner, a heat conductive sheet was formed. In the sheet, the total volume ratio of boron nitride was 20% by volume, and the volume ratio of talc was 40% by volume. The obtained sheet had a thermal conductivity of 2.54 W / m · K.

Example 21
To 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.), 114 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size: 18 μm), crosslinked polystyrene particles A heat conductive sheet was formed in the same manner as Comparative Example 7 except that 105 parts by weight (“Techpolymer SBX-12” manufactured by Sekisui Plastics Co., Ltd., average particle size: 12 μm) was charged. In the sheet, the volume ratio of boron nitride was 20% by volume, and the volume ratio of crosslinked polystyrene particles was 40% by volume. The obtained sheet had a thermal conductivity of 1.13 W / m · K.

Example 22
To 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.), 114 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size: 18 μm), crosslinked PMMA particles A heat conductive sheet was formed in the same manner as Comparative Example 7 except that 119 parts by weight (“Techpolymer MBX-12” manufactured by Sekisui Plastics Co., Ltd., average particle size: 12 μm) was charged. In the sheet, the volume ratio of boron nitride was 20% by volume, and the volume ratio of crosslinked PMMA particles was 40% by volume. The obtained sheet had a thermal conductivity of 1.24 W / m · K.

Comparative Example 14
120 parts by weight of spherical alumina particles (“DAW45” manufactured by Electrochemical Co., Ltd., average particle size 45 μm) are further added to 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.), spherical alumina 80 parts by weight of particles (“DAW03” manufactured by Electrochemical Co., Ltd., average particle size 3 μm), 121 parts by weight of crosslinked PMMA particles (“Techpolymer MBX-50” manufactured by Sekisui Plastics Co., Ltd., average particle size 50 μm) A thermally conductive sheet was formed in the same manner as in Comparative Example 7 except that it was charged. In the sheet, the total volume ratio of the spherical alumina particles was 20% by volume, and the volume ratio of the crosslinked PMMA particles was 40% by volume. The obtained sheet had a thermal conductivity of 0.37 W / m · K. Compared with Example 17 which mix | blended the same quantity of boron nitride and bridge | crosslinking PMMA particle | grains, thermal conductivity fell.

Example 23
To 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.), 103 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size 18 μm), boron nitride ( 12 parts by weight of “SP-3” manufactured by Electrochemical Co., Ltd., average particle diameter of 3 μm, 121 parts by weight of crosslinked PMMA particles (“Techpolymer MBX-50” manufactured by Sekisui Plastics Co., Ltd., average particle diameter of 50 μm) A thermally conductive sheet was formed in the same manner as in Comparative Example 7 except that it was charged. In the sheet, the total volume ratio of boron nitride was 20% by volume, and the volume ratio of crosslinked PMMA particles was 40% by volume. The obtained sheet had a thermal conductivity of 1.47 W / m · K.

Example 24
To 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.), 57 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size: 18 μm), spherical alumina particles Comparative Example 7 with the exception of charging 100 parts by weight (“DAW03” manufactured by Electrochemical Co., Ltd., average particle size 3 μm) and 121 parts by weight of talc (“MS-KY” manufactured by Nippon Talc Co., Ltd., average particle size 27 μm). Similarly, a heat conductive sheet was formed. In the sheet, the volume ratio of boron nitride was 10% by volume, the volume ratio of spherical alumina particles was 10% by volume, and the volume ratio of crosslinked PMMA particles was 40% by volume. The obtained sheet had a thermal conductivity of 0.99 W / m · K.

Example 25
340 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size 18 μm) and 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.) A thermally conductive sheet was molded in the same manner as Comparative Example 7 except that 593 parts by weight of methyl acid (PMMA) particles (“Techpolymer MBX-50” manufactured by Sekisui Plastics Co., Ltd., average particle size 50 μm) were charged. In the sheet, the volume ratio of boron nitride was 20% by volume, and the volume ratio of crosslinked PMMA particles was 50% by volume. The obtained sheet had a thermal conductivity of 1.56 W / m · K.

Example 26
226 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size 18 μm) and 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.), crosslinked polymethacrylic A thermally conductive sheet was molded in the same manner as in Comparative Example 7 except that 356 parts by weight of methyl acid (PMMA) particles (“Techpolymer MBX-50” manufactured by Sekisui Plastics Co., Ltd., average particle size 50 μm) were charged. In the sheet, the volume ratio of boron nitride was 20% by volume, and the volume ratio of crosslinked PMMA particles was 60% by volume. The obtained sheet had a thermal conductivity of 1.53 W / m · K.

  The evaluation results of Examples 25 and 26 are shown in the graph of FIG. In FIG. 7, the results of Comparative Example 8 and Examples 18 to 19 are also shown. As is clear from FIG. 7, the thermal conductivity was improved by the incorporation of the crosslinked PMMA particles, but was smaller than that of talc.

Comparative Example 15
For 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.), cross-linked polyacrylate particles (“Tech Polymer ARX-30” manufactured by Sekisui Plastics Co., Ltd.) and average particles A thermally conductive sheet was formed in the same manner as in Comparative Example 7 except that 73 parts by weight (diameter 30 μm) was charged. In the sheet, the volume ratio of the crosslinked polyacrylic ester particles was 40% by volume. The obtained sheet had a thermal conductivity of 0.24 W / m · K.

Example 27
45 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size 18 μm), 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.), crosslinked polyacrylic acid A thermally conductive sheet was molded in the same manner as in Comparative Example 7 except that 87 parts by weight of ester particles (“Techpolymer ARX-30” manufactured by Sekisui Plastics Co., Ltd., average particle size: 30 μm) was charged. In the sheet, the volume ratio of boron nitride was 10% by volume, and the volume ratio of crosslinked polyacrylate particles was 40% by volume. The obtained sheet had a thermal conductivity of 0.40 W / m · K.

Example 28
Boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size 18 μm) 114 parts by weight, crosslinked polyacrylic acid with respect to 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.) A thermally conductive sheet was molded in the same manner as in Comparative Example 7, except that 109 parts by weight of ester particles (“Techpolymer ARX-30” manufactured by Sekisui Plastics Co., Ltd., average particle size 30 μm) was charged. In the sheet, the volume ratio of boron nitride was 20% by volume, and the volume ratio of crosslinked polyacrylate particles was 40% by volume. The obtained sheet had a thermal conductivity of 1.46 W / m · K.

Example 29
275 parts by weight of boron nitride (“SGP” manufactured by Electrochemical Co., Ltd., average particle size 18 μm), 100 parts by weight of polyamide elastomer (“E-40-S1” manufactured by Daicel Evonik Co., Ltd.), crosslinked polyacrylic acid A thermally conductive sheet was molded in the same manner as in Comparative Example 7 except that 158 parts by weight of ester particles (“Tech Polymer ARX-30” manufactured by Sekisui Plastics Co., Ltd., average particle size: 30 μm) was charged. In the sheet, the volume ratio of boron nitride was 33% by volume, and the volume ratio of crosslinked polyacrylate particles was 40% by volume. The obtained sheet had a thermal conductivity of 3.00 W / m · K.

  The evaluation results of Comparative Example 15 and Examples 27 to 29 are shown in the graph of FIG. In addition, in FIG. 8, the result of Comparative Examples 7-10 was also described collectively. As is clear from FIG. 8, in the example, the thermal conductivity is higher than in Comparative Examples 7 to 10, and the thermal conductivity is effectively improved by blending the crosslinked polyacrylate particles. Recognize.

  Furthermore, in order to evaluate the hardness of the heat conductive sheet obtained in Examples 27 to 29 in which crosslinked polyacrylate particles were blended, Comparative Example 15 and Examples in which crosslinked acrylate particles were blended as heat resistant particles Obtained in Comparative Examples 7 to 10 in which the heat conductive sheets obtained in 27 to 29, Comparative Example 12 in which talc is blended as heat resistant particles, and the heat conductive sheets in Example 16 and heat resistant particles are not blended. The results of measuring the hardness of the thermally conductive sheet are shown in the graph of FIG. In addition, each hardness is Comparative Example 15: 88.8, Example 27: 95.6, Example 28: 97.2, Example 29: 97.4, Comparative Example 12: 97.4, Example 16: The results were 97.6, Comparative Example 7: 93.4, Comparative Example 8: 97.4, Comparative Example 9: 97.5, and Comparative Example 10: 97.6. As can be seen from FIG. 9, when the boron nitride concentration is about 20% by volume or less, the use of crosslinked polyacrylate particles as heat-resistant particles improves the flexibility.

  The heat conductive resin composition of the present invention can be used for various applications that require heat conductivity. For example, image display devices, computers, electric / electronic parts such as batteries (heat sinks, thermoelectric conversion elements, photoelectric conversion elements) , Electromagnetic wave absorbing and heat radiating material, substrate, separator, etc.). In particular, the insulating resin composition is also useful as a heat sink for a computer CPU, power module, LED, and the like.

Claims (9)

  A thermally conductive resin composition comprising a thermally conductive inorganic filler having an anisotropic shape, heat resistant particles and a thermoplastic resin, wherein the heat resistant particles can maintain a particle shape at a melting temperature of the thermoplastic resin. A thermal conductive resin composition.   The heat conductive resin composition according to claim 1, wherein the heat resistant particles have an average particle diameter of 1 to 50 μm and a heat conductivity of 30 W / m · K or less.   The heat conductive resin composition according to claim 1 or 2, wherein the heat resistant particles are talc or crosslinked polyacrylate particles.   The thermally conductive resin composition according to any one of claims 1 to 3, wherein the thermally conductive inorganic filler is a plate-like or fibrous conductive or insulating inorganic filler.   The thermally conductive resin composition according to claim 1, wherein the thermally conductive inorganic filler is boron nitride.   The ratio (volume ratio) of a heat conductive inorganic filler and heat-resistant particle | grains is the former / latter = 2/1-1/4, The heat conductive resin composition in any one of Claims 1-5.   The thermally conductive resin composition according to any one of claims 1 to 6, wherein the thermoplastic resin is at least one selected from the group consisting of polyamide resins, polyamide elastomers, and cyclic olefin elastomers.   The ratio of a heat conductive inorganic filler is 5-40 volume% with respect to the whole composition, and heat conductivity is 1 W / m * K or more, The heat conductivity in any one of Claims 1-7. Resin composition.   The heat conductive sheet comprised with the heat conductive resin composition in any one of Claims 1-8.

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