JP2009013232A - Highly thermally-conductive thermoplastic resin composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly thermally-conductive thermoplastic resin composition having improved molding fluidity in injection molding and also having environmental compatibility such as biodegradability and carbon neutral. <P>SOLUTION: The highly thermally-conductive thermoplastic resin composition comprises a (3-hydroxyalkanoate) copolymer comprising a repeating unit represented by the formula: [-CHR-CH<SB>2</SB>-CO-O-] (wherein R represents an alkyl group represented by C<SB>n</SB>H<SB>2n+1</SB>(n is an integer of 1-15)) and a highly thermally-conductive inorganic compound having a thermal conductivity of &ge;10 W/m K as a simple substance. The thermoplastic resin composition has a thermal conductivity of &ge;0.8 W/m K. Since the solidification rate of the resin in a mold can be reduced in injection molding, molding fluidity in injection molding is not deteriorated in spite of the high thermal conductivity. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to a high thermal conductive thermoplastic resin composition that has revolutionarily improved the problem of a high thermal conductive resin that injection molding is difficult due to rapid cooling and solidification. Furthermore, a highly thermally conductive thermoplastic resin composition comprising a plant-derived biodegradable polymer obtained by positively fixing carbon dioxide on the earth and expected to prevent global warming, and a molded article using the same About. More specifically, a resin composition having both high thermal conductivity and excellent moldability, comprising a poly (3-hydroxyalkanoate) copolymer, which is a biodegradable aliphatic polyester resin, and a high thermal conductivity inorganic compound. And a molded body.

  When a thermoplastic resin composition is used in various applications such as personal computers and display housings, electronic device materials, automotive interiors and exteriors, plastic is generated because it has lower thermal conductivity than inorganic materials such as metal materials. Difficult to escape heat can be a problem. In order to solve such problems, attempts have been widely made to obtain a high thermal conductive resin composition by blending a large amount of a high thermal conductive inorganic substance in a thermoplastic resin. As the highly heat-conductive inorganic compound, a highly heat-conductive inorganic material such as graphite, carbon fiber, alumina, boron nitride, etc. is usually required to be blended in the resin at a high content of 30% by volume or more, and further 50% by volume or more. There is.

  However, if a high thermal conductivity thermoplastic resin is to be molded by a commonly used injection molding method, the resin that has flowed into the mold is cooled and solidified at a high speed because of its high thermal conductivity, and the gate portion in the mold After solidifying, there is a problem that the resin cannot be allowed to flow into the mold at all. In order to solve this, special molds such as a combination of hot runners and specially shaped gates are required when injection molding high thermal conductivity thermoplastic resin, making it impossible to mold with general purpose molds. There is an obstacle to the spread.

  On the other hand, as plastics are used and disposed of in large quantities in recent years, development of biodegradable plastics has become active as a solution to the problem of plastic waste. Also, among these biodegradable plastics, those derived from plants are produced by absorbing and fixing carbon dioxide in the air, so they are produced when these plant-derived biodegradable plastics are discarded by combustion or the like. Carbon dioxide was originally in the air, and atmospheric carbon dioxide does not increase. This is called carbon neutral and is regarded as important because it is effective in preventing global warming.

As a resin corresponding to these problems, a general formula (1): [—CHR—CH ₂ —CO—O—] (a plant-derived biodegradable polymer obtained by positively fixing carbon dioxide on the earth) In the formula, R represents an alkyl group represented by C _n H _{2n + 1} , and n is an integer of 1 to 15.) (3-hydroxyalkanoate) copolymer (hereinafter abbreviated as PHBH) is promising. Currently, research and development is underway. However, since the crystallization speed of PHBH is very slow depending on the composition, when trying to mold with a normal mold by the injection molding method, the solidification speed becomes very slow and the resin is completely solidified in the mold. Since it takes a very long time to be taken out, there is a problem that the molding cycle becomes long and the productivity at the time of molding becomes low.

As a study for increasing the crystallization speed of PHBH, for example, Patent Document 1 discloses a method of adding a crystal nucleating agent such as wood flour, but further speed improvement is required.
JP 2006-45366 A

In view of the above situation, the present invention makes it possible to mold a high thermal conductivity thermoplastic resin even in a general purpose injection molding mold by significantly slowing down the solidification rate of the high thermal conductivity thermoplastic resin during cooling in the mold. There is.

  The present inventor has found that the solidification rate at the time of cooling in the mold of the high thermal conductivity thermoplastic resin composition can be significantly delayed by effectively utilizing the property that PHBH has a low solidification rate. Furthermore, the present resin composition was found to have excellent environmental compatibility such as biodegradability and carbon neutral, and the present invention was reached.

That is, the present invention
General formula (1): represented by [—CHR—CH ₂ —CO—O—] (wherein R represents an alkyl group represented by C _n H _{2n + 1} , and n is an integer of 1 to 15). A high thermal conductive inorganic compound (B) having a thermal conductivity of 10 / m · K or more as a single unit with respect to the (3-hydroxyalkanoate) copolymer (A) comprising repeating units It is a high thermal conductivity thermoplastic resin composition (Claim 1), characterized in that the thermal conductivity of the thermoplastic resin composition obtained is 0.8 W / mK or more,
The resin composition (claim 2) according to claim 1, wherein the (3-hydroxyalkanoate) copolymer (A) is biodegradable.
The (3-hydroxyalkanoate) copolymer (A) is a poly [(3-hydroxybutyrate)-(3 comprising (3-hydroxybutyrate) repeating units and (3-hydroxyhexanoate) repeating units. -Hydroxyhexanoate)] copolymer, which is a resin composition (claim 3) according to claim 1 or 2,
The high thermal conductivity thermoplastic resin according to any one of claims 1 to 3, wherein the (3-hydroxyalkanoate) copolymer (A) has a weight average molecular weight Mw of 300,000 to 3,000,000. A resin composition (claim 4);
The constitutional ratio of the repeating unit of the [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] copolymer is (3-hydroxybutyrate) unit / (3-hydroxyhexanoate) unit = 99. / 1 to 80/20 (mol / mol), The resin composition according to claim 3 (claim 5),
2. (B) is at least one highly thermally conductive inorganic compound selected from the group consisting of graphite, conductive metal powder, soft magnetic ferrite, carbon fiber, and conductive metal fiber. It is a highly heat-conductive thermoplastic resin composition (claim 6) of any one of -5,
The high thermal conductivity according to any one of claims 1 to 5, wherein (B) is an electrically insulating high thermal conductive inorganic compound having a single thermal conductivity of 20 W / m · K or more. A thermoplastic resin composition (claim 7);
(B) is at least one highly thermally conductive inorganic material selected from the group consisting of boron nitride, aluminum nitride, silicon nitride, aluminum oxide, magnesium oxide, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, beryllium oxide, and diamond. It is a high thermal conductivity thermoplastic resin composition (claim 8) according to any one of claims 1 to 5 or 7, characterized in that it is a compound.
(A) / (B) volume ratio in the composition of (3-hydroxyalkanoate) copolymer (A) / high thermal conductive inorganic compound (B) is in the range of 5/95 to 95/5. It is a high thermal conductivity thermoplastic resin composition (claim 9) according to any one of claims 1 to 8,
It is a high heat conductive molded object (Claim 10) produced by injection-molding the high heat conductive thermoplastic resin composition of any one of Claims 1-9.

  By using the method of the present invention, the molding processability at the time of injection molding was successfully improved by delaying the solidification rate of the highly heat conductive thermoplastic resin composition during cooling in the mold. Furthermore, this resin composition has excellent environmental compatibility such as biodegradability and carbon neutrality.

  The composite materials obtained in this way are in various forms such as resin films, resin molded products, resin foams, paints and coating agents, electronic materials, magnetic materials, catalyst materials, structural materials, optical materials, medical materials, etc. It can be widely used for various applications such as materials, automobile materials, and building materials. The high thermal conductivity thermoplastic resin composition obtained in the present invention has a complicated shape because a general plastic molding machine such as an injection molding machine or an extrusion molding machine that is widely used at present can be used. Molding into products is easy. In particular, it has excellent properties such as excellent processability, high thermal conductivity, and plant origin, so it is very useful as a resin for a casing of a mobile phone, a display, a computer or the like having a heat source inside.

As the thermoplastic resin in the present invention, the general formula (1): [—CHR—CH ₂ —CO—O is derived from the property of decomposing under anaerobic properties, excellent moisture resistance, and high molecular weight. -(Wherein R represents an alkyl group represented by C _n H _{2n + 1} , and n is an integer of 1 to 15) (3-hydroxyalkanoate) copolymer ( A) is used.

  Representative examples of the (3-hydroxyalkanoate) copolymer in the present invention include, for example, (3-hydroxybutyrate)-(3-hydroxyhexanoate) copolymer, (3-hydroxybutyrate)-( (3-hydroxyoctanoate) copolymer, (3-hydroxybutyrate)-(3-hydroxydecanoate) copolymer, and the like. Among these, [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] copolymers are preferable, and copolymers produced by microorganisms are more preferable. If necessary, in addition to polyglycolic acid, polylactic acid, poly-3-hydroxybutyric acid, poly-4-hydroxybutyric acid, poly-4-hydroxyvaleric acid, poly-3-hydroxyhexanoic acid or polycaprolactone, aliphatic polyvalent One or two aliphatic polyesters such as polyethylene adipate, polyethylene succinate, polybutylene adipate, polybutylene succinate or a copolymer thereof as a polymer mainly composed of carboxylic acid and aliphatic polyhydric alcohol More than seeds can be added.

  Here, the [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] copolymer is a general term for copolymers mainly composed of 3-hydroxybutyrate and 3-hydroxyhexanoate. It is what is used. As long as the copolymer is mainly composed of 3-hydroxybutyrate and 3-hydroxyhexanoate, the copolymer may contain other monomer components as described above. The polymerization method for obtaining the copolymer is not particularly limited, and any copolymerization method such as random copolymerization, alternating copolymerization, or block copolymerization may be applied. Since physical properties are easily controlled, it is preferable to obtain a random copolymer rather than a block copolymer.

  The constitutional ratio of the repeating unit of the [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] copolymer in the present invention is (3-hydroxybutyrate) unit / (3-hydroxyhexanoate). The unit is preferably 99/1 to 80/20 (mol / mol), more preferably 98/2 to 82/18 (mol / mol), and 97/3 to 85/15 (mol / mol). More preferably, The constituent ratio of the repeating unit of the [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] copolymer may be abbreviated as HH ratio.

Although the molecular weight of the (3-hydroxyalkanoate) copolymer of the present invention is not particularly limited, the weight average molecular weight is preferably 300,000 to 3,000,000, more preferably 400,000 to 2,500,000, and 500,000. More preferably, it is ˜2 million. If the weight average molecular weight of the (3-hydroxyalkanoate) copolymer is less than 300,000, mechanical properties such as strength may be insufficient, and if it exceeds 3 million, moldability may be inferior.
The method for measuring the weight average molecular weight of the (3-hydroxyalkanoate) copolymer is not particularly limited, but as an example, chloroform is used as the mobile phase, and the system is a Waters GPC system. In addition, by using Shodex K-804 (polystyrene gel) manufactured by Showa Denko KK, the molecular weight in terms of polystyrene of the resin composition of the present invention can be obtained.
In the thermoplastic resin composition of the present invention, various thermoplastic resins other than the (3-hydroxyalkanoate) copolymer (A) can be further used as necessary. The thermoplastic resin other than the (3-hydroxyalkanoate) copolymer may be a synthetic resin or a resin existing in nature.

  Examples of thermoplastic resins other than (3-hydroxyalkanoate) copolymers include aromatic vinyl resins such as polystyrene, vinyl cyanide resins such as polyacrylonitrile, chlorine resins such as polyvinyl chloride, and polymethyl methacrylate. Polymethacrylate resins, polyacrylate resins, polyolefin resins such as polyethylene, polypropylene and cyclic polyolefin resins, polyvinyl ester resins such as polyvinyl acetate, polyvinyl alcohol resins and their derivative resins, poly Obtained by polymerizing methacrylic acid resins, polyacrylic acid resins and their metal salt resins, polyconjugated diene resins, polymers obtained by polymerizing maleic acid, fumaric acid and their derivatives, and maleimide compounds. Polymer, amorphous semi-fine Amorphous polyester resins such as aromatic polyesters and amorphous wholly aromatic polyesters, crystalline polyester resins such as crystalline semi-aromatic polyesters and crystalline wholly aromatic polyesters, aliphatic polyamides and aliphatic-aromatic polyamides And polyamide resins such as wholly aromatic polyamides, polycarbonate resins, polyurethane resins, polysulfone resins, polyalkylene oxide resins, cellulose resins, polyphenylene ether resins, polyphenylene sulfide resins, polyketone resins, polyimide resins , Polyamideimide resin, polyetherimide resin, polyetherketone resin, polyetheretherketone resin, polyvinylether resin, phenoxy resin, fluorine resin, silicone resin, liquid crystal polymer, and this Random block graft copolymer exemplified polymers, and the like. Thermoplastic resins other than these (3-hydroxyalkanoate) copolymers can be used alone or in combination of two or more. When two or more kinds of resins are used in combination, a compatibilizing agent or the like can be added as necessary. What is necessary is just to use properly thermoplastic resins other than these (3-hydroxyalkanoate) copolymers according to the objective.

  Among the thermoplastic resins other than these (3-hydroxyalkanoate) copolymers, a part or all of the resin is a thermoplastic resin having crystallinity or liquid crystallinity. It is preferable from the viewpoint that the rate tends to be high and that it is easy to contain the inorganic compound (B) in the resin. These thermoplastic resins having crystallinity or liquid crystallinity are part of the resin such that only a specific block in the molecule of the block or graft copolymer resin is crystalline or liquid crystalline even if the entire resin is crystalline. Only may be crystalline or liquid crystalline. There is no particular limitation on the crystallinity of the resin. Further, as a thermoplastic resin other than the (3-hydroxyalkanoate) copolymer, a polymer alloy of an amorphous resin and a crystalline or liquid crystalline resin can also be used. There is no particular limitation on the crystallinity of the resin.

  Some thermoplastic resins other than copolymers having a crystalline or liquid crystalline (3-hydroxyalkanoate) copolymer may be used alone or even if they can be crystallized. Depending on the molding process conditions, there are some resins that exhibit amorphous properties. When such a resin is used, the amount of the inorganic compound (B) can be adjusted by adjusting the amount and method of addition, or by devising a molding method such as stretching or post-crystallization. In some cases, part or the whole can be crystallized.

  Among the thermoplastic resins having crystallinity or liquid crystallinity, preferred resins include crystalline polyester resin, crystalline polyamide resin, polyphenylene sulfide resin, liquid crystal polymer, crystalline polyolefin resin, polyolefin block copolymer, etc. However, the present invention is not limited to these, and various crystalline resins and liquid crystalline resins can be used.

  The high thermal conductivity inorganic compound (B) with a single thermal conductivity of 10 W / m · K or more blended in the thermoplastic resin composition of the present invention has a single thermal conductivity of 10 W / m · K or more. Things can be used. Less than 10 W / m · K is not preferable because the effect of improving the thermal conductivity of the composition is inferior. The thermal conductivity of the single substance is preferably 12 W / m · K or more, more preferably 15 W / m · K or more, most preferably 20 W / m · K or more, particularly preferably 30 W / m · K or more. It is done. The upper limit of the thermal conductivity of the high thermal conductivity inorganic compound (B) alone is not particularly limited and is preferably as high as possible. Generally, it is 3000 W / m · K or less, more preferably 2500 W / m · K or less. Those are preferably used.

  When the composition is used for applications that do not particularly require electrical insulation, a metal compound or a conductive carbon compound is preferably used as the highly thermally conductive inorganic compound (B). Among these, since it is excellent in thermal conductivity, conductive carbon materials such as graphite and carbon fiber, conductive metal powder obtained by atomizing various metals, conductive metal fibers obtained by processing various metals into fibers, various ferrites And metal oxides such as zinc oxide can be preferably used.

When the composition is used for applications requiring electrical insulation, a compound exhibiting electrical insulation is preferably used as the high thermal conductivity inorganic compound (B). Specifically, the electrical insulating property indicates an electrical resistivity of 1 Ω · cm or more, preferably 10 Ω · cm or more, more preferably 10 ⁵ Ω · cm or more, and further preferably 10 ¹⁰ Ω · cm or more. It is preferable to use a material having a size of cm or more, most preferably 10 ¹³ Ω · cm or more. There is no particular restriction on the upper limit of the electrical resistivity, generally less 10 ¹⁸ Ω · cm. It is preferable that the electrical insulation of the molded product obtained from the high thermal conductivity thermoplastic resin composition of the present invention is also in the above range.
Specifically, among the high thermal conductivity inorganic compounds (B), the compounds exhibiting electrical insulation include, specifically, metal oxides such as aluminum oxide, magnesium oxide, silicon oxide, beryllium oxide, copper oxide, cuprous oxide, and nitriding Metal nitride such as boron, aluminum nitride and silicon nitride, metal carbide such as silicon carbide, metal carbonate such as magnesium carbonate, insulating carbon material such as diamond, metal water such as aluminum hydroxide and magnesium hydroxide An oxide can be illustrated.

  Among these, since it has excellent electrical insulation properties, metal nitrides such as boron nitride, aluminum nitride, and silicon nitride, metal oxides such as aluminum oxide, magnesium oxide, and beryllium oxide, metal carbonates such as magnesium carbonate, aluminum hydroxide Metal hydroxides such as magnesium hydroxide, and insulating carbon materials such as diamond can be more preferably used. These can be used alone or in combination.

  About the shape of a highly heat conductive inorganic compound (B), the thing of a various shape is applicable. For example, particles, fine particles, nanoparticles, aggregated particles, tubes, nanotubes, wires, rods, needles, plates, irregular shapes, rugby balls, hexahedrons, large particles and fine particles are combined Various shapes such as a complex particle shape and a liquid can be exemplified. These high thermal conductivity inorganic compounds (B) may be natural products or synthesized ones. In the case of a natural product, there are no particular limitations on the production area and the like, which can be selected as appropriate. These high heat conductive inorganic compounds (B) may be used alone or in combination of two or more different shapes, average particle diameters, types, surface treatment agents and the like.

  These highly heat-conductive inorganic compounds (B) have been surface-treated with various surface treatment agents such as silane treatment agents in order to increase the adhesion at the interface between the resin and the inorganic compound or to facilitate workability. It may be. It does not specifically limit as a surface treating agent, For example, conventionally well-known things, such as a silane coupling agent and a titanate coupling agent, can be used. Among them, an epoxy group-containing silane coupling agent such as epoxy silane, an amino group-containing silane coupling agent such as aminosilane, polyoxyethylene silane, and the like are preferable because they hardly reduce the physical properties of the resin. The surface treatment method of the inorganic compound is not particularly limited, and a normal treatment method can be used.

  The use amount of the (3-hydroxyalkanoate) copolymer (A) and the high thermal conductive inorganic compound (B) in the thermoplastic resin composition of the present invention is such that (A) / (B) volume ratio is 5/95 to It is preferable to contain so that it may become 95/5. The greater the amount of 3-hydroxyalkanoate) copolymer (A) used, the better the impact resistance, surface properties, and molding processability of the resulting molded product, and easier kneading with the resin during melt-kneading. In light of the tendency, the lower limit of the volume ratio is preferably 10/90 or more, more preferably 15/85 or more, and most preferably 20/80 or more. Further, from the viewpoint that thermal conductivity tends to improve as the amount of compound (B) increases, the upper limit of the volume ratio is preferably 80/20 or less, more preferably 75/25 or less, still more preferably 70/30 or less, Most preferably, it is 65/35 or less.

  In order to further improve the heat resistance and mechanical strength of the resin composition, an inorganic compound other than (B) can be further added to the thermoplastic resin composition of the present invention as long as the characteristics of the present invention are not impaired. Such an inorganic compound is not particularly limited. However, since the addition of these inorganic compounds may affect the thermal conductivity, attention should be paid to the amount added. These inorganic compounds may also be surface treated. When using these, it is preferable that the addition amount is 100 weight part or less with respect to 100 weight part of (3-hydroxyalkanoate) copolymers (A). When the addition amount exceeds 100 parts by weight, impact resistance is lowered and molding processability may be lowered. Preferably it is 50 weight part or less, More preferably, it is 10 weight part or less. In addition, as the addition amount of these inorganic compounds increases, the surface property and dimensional stability of the molded product tend to deteriorate. Therefore, when these characteristics are important, the addition amount of the inorganic compound should be as small as possible. It is preferable to do.

  Moreover, in order to make the thermoplastic resin composition of the present invention higher performance, a thermal stabilizer such as a phenol-based stabilizer, a sulfur-based stabilizer, a phosphorus-based stabilizer, etc., alone or in combination of two or more kinds. It is preferable to add. Furthermore, as required, generally well-known stabilizers, lubricants, mold release agents, plasticizers, flame retardants other than phosphorus, flame retardant aids, ultraviolet absorbers, light stabilizers, pigments, dyes, charging An inhibitor, a conductivity imparting agent, a dispersant, a compatibilizing agent, an antibacterial agent and the like may be added alone or in combination of two or more.

It does not specifically limit as a manufacturing method of the thermoplastic resin composition of this invention. For example, it can be produced by drying the above-described components, additives and the like and then melt-kneading them in a melt-kneader such as a single-screw or twin-screw extruder. Moreover, when a compounding component is a liquid, it can also manufacture by adding to a melt-kneader on the way using a liquid supply pump etc.
The method for molding the thermoplastic resin composition of the present invention is not particularly limited. For example, a molding method generally used for thermoplastic resins, such as injection molding, blow molding, extrusion molding, vacuum molding, press molding, Calendar molding can be used. Among these, it is preferable to perform injection molding by an injection molding method because the molding cycle is short, the production efficiency is excellent, and the composition has good fluidity at the time of injection molding.
The composition of the present invention exhibits good thermal conductivity as shown in the examples, and is 0.8 W / m · K or more, preferably 1 W / m · K or more, more preferably 1.3 W / m · K or more. It is possible to obtain a molded body.
In the resin composition of this invention, a moldability can further be improved by adding crystallization promoters, such as a nucleating agent, as needed.

  Examples of the crystallization accelerator used in the present invention include higher fatty acid amides, urea derivatives, sorbitol compounds, higher fatty acid salts, aromatic fatty acid salts and the like, and these can be used alone or in combination of two or more. . Of these, higher fatty acid amides, urea derivatives, and sorbitol compounds are preferred because of their high effects as crystallization accelerators.

  Examples of the higher fatty acid amide include behenic acid amide, oleic acid amide, erucic acid amide, stearic acid amide, palmitic acid amide, N-stearyl behenic acid amide, N-stearyl erucic acid amide, ethylenebisstearic acid amide, ethylene Examples include bisoleic acid amide, ethylene biserucic acid amide, ethylene bislauric acid amide, ethylene biscapric acid amide, p-phenylene bis stearic acid amide, polycondensates of ethylenediamine, stearic acid, and sebacic acid, especially behenic acid. Amides are preferred.

Examples of the urea derivative include bis (stearylureido) hexane, 4,4′-bis (3-methylureido) diphenylmethane, 4,4′-bis (3-cyclohexylureido) diphenylmethane, 4,4′-bis (3- Cyclohexylureido) dicyclohexylmethane, 4,4′-bis (3-phenylureido) dicyclohexylmethane, bis (3-methylcyclohexylureido) hexane, 4,4′-bis (3-decylureido) diphenylmethane, N-octyl-N ′ -Phenylurea, N, N'-diphenylurea, N-tolyl-N'-cyclohexylurea, N, N'-dicyclohexylurea, N-phenyl-N'-tribromophenylurea, N-phenyl-N'-tolylurea N-cyclohexyl-N′-phenylurea and the like, Bis (stearyl ureido) hexane is preferred.
Examples of the sorbitol compounds include 1,3,2,4-di (p-methylbenzylidene) sorbitol, 1,3,2,4-dibenzylidene sorbitol, 1,3-benzylidene-2,4-p-methylbenzylidene. Sorbitol, 1,3-benzylidene-2,4-p-ethylbenzylidene sorbitol, 1,3-p-methylbenzylidene-2,4-benzylidene sorbitol, 1,3-p-ethylbenzylidene-2,4-benzylidene sorbitol, 1,3-p-methylbenzylidene-2,4-p-ethylbenzylidene sorbitol, 1,3-p-ethylbenzylidene-2,4-p-methylbenzylidene sorbitol, 1,3,2,4-di (p- Ethylbenzylidene) sorbitol, 1,3,2,4-di (pn-propylbenzylidene) sorbi 1,3,2,4-di (p-i-propylbenzylidene) sorbitol, 1,3,2,4-di (pn-butylbenzylidene) sorbitol, 1,3,2,4-di ( p-s-butylbenzylidene) sorbitol, 1,3,2,4-di (pt-butylbenzylidene) sorbitol, 1,3,2,4-di (p-methoxybenzylidene) sorbitol, 1,3,2 , 4-di (p-ethoxybenzylidene) sorbitol, 1,3-benzylidene-2,4-p-chlorobenzylidene sorbitol, 1,3-p-chlorobenzylidene-2,4-benzylidenesorbitol, 1,3-p- Chlorbenzylidene-2,4-p-methylbenzylidenesorbitol, 1,3-p-chlorobenzylidene-2,4-p-ethylbenzylidenesorbitol, 1 3-p-methylbenzylidene-2,4-p-chlorobenzylidene sorbitol, 1,3-p-ethylbenzylidene-2,4-p-chlorobenzylidene sorbitol, and 1,3,2,4-di (p-chloro) Benzylidene) sorbitol and the like. Among these, 1,3,2,4-di (p-methylbenzylidene) sorbitol and 1,3,2,4-dibenzylidenesorbitol are preferable.

  The amount of the crystallization accelerator used in the resin composition of the present invention is preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of the (3-hydroxyalkanoate) copolymer (A) in terms of moldability. 0.03 to 4 parts by weight is more preferable, and 0.05 to 3 parts by weight is further preferable. If it is less than 0.01 part by weight, the effect as a crystallization accelerator may be insufficient, and if it exceeds 5 parts by weight, the effect may be saturated. Physical properties may be impaired.

  The high thermal conductive resin composition of the present invention can be suitably used for injection molded products such as home appliances, OA equipment parts, AV equipment parts, automobile interior and exterior parts, and the like. In particular, it can be suitably used as an exterior material in home appliances and office automation equipment that generate a lot of heat.

Furthermore, in an electronic device having a heat source inside but difficult to be forcibly cooled by a fan or the like, it is suitably used as an exterior material for these devices in order to dissipate the heat generated inside to the outside. Among these, small or portable electronic devices such as portable computers such as notebook computers, PDAs, cellular phones, portable game machines, portable music players, portable TV / video devices, portable video cameras, etc. are preferable among these. It is very useful as a resin for housings, housings, and exterior materials. It can also be used very effectively as a resin for battery peripherals in automobiles, trains, etc., a resin for portable batteries in home appliances, a resin for power distribution parts such as breakers, and a sealing material for motors.
The high thermal conductive resin composition of the present invention has better molding processability, impact resistance, and surface properties of the resulting molded body than the conventionally well-known compositions. It has characteristics useful for a housing.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.
Next, the composition of the present invention and the molded product thereof will be described in more detail based on examples, but the present invention is not limited to such examples.
The raw materials used in the present invention are as follows.
(3-hydroxyalkanoate) copolymer (A)
(PHBH-1): [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] (HH ratio = 12%, Mw = 500,000)
(PHBH-2): [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] (HH ratio = 7%, Mw = 500,000)
(PHBH-3): [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] (HH ratio = 4%, Mw = 500,000)
Note that PHBH uses Alcaligenes eutrophus AC32 (J. Bacteriol., 179, 4821 (1997)) in which PHA synthase gene derived from Aeromonas caviae is introduced into Alcaligenes eutrophus as a microorganism, and the raw materials and culture conditions are appropriately adjusted. PHBH produced in the following manner, the HH ratio is 12 mol% (PHBH-1), 7 mol% (PHBH-2), 4 mol% (PHBH-3), and the Mw (weight average molecular weight) is about 500,000 each. used.
Here, the HH ratio is a molar ratio of (3-hydroxyhexanoate) units to (3-hydroxybutyrate) units + (3-hydroxyhexanoate) units, and is calculated from measurement by NMR.

Example 1
100 parts by weight of (3-hydroxyalkanoate) copolymer (A) (PHBH-1) was mixed with 0.2 parts by weight of phenol stabilizer AO-60 (manufactured by ADEKA). Things were prepared (raw material 1). Separately, a true spherical alumina powder (DAW-03 manufactured by Denki Kagaku Kogyo Co., Ltd.), a thermal conductivity of 35 W / m · K as a single unit, a volume average particle diameter of 3 μm, electrical insulation, Volume specific resistance 10 ¹⁶ Ω · cm) (FIL-1) 100 parts by weight, Shin-Etsu Chemical epoxy silane KBM-303 1 part by weight, ethanol 5 parts by weight were mixed with a super floater and stirred for 5 minutes. Then, what was dried at 80 degreeC for 4 hours was prepared. (Raw material 2).

  Raw material 1 and raw material 2 were mixed with a Henschel mixer using (3-hydroxyalkanoate) copolymer (A) and high thermal conductive inorganic compound (B) by volume ratio (A) / (B) = 40/60. Then, the mixture was fed from a hopper provided in the vicinity of the screw root of a KZW15-45 same-direction meshing twin screw extruder manufactured by Technobel. The set temperature was 100 ° C. in the vicinity of the supply port, the set temperature was sequentially increased, and the screw tip was set at 135 ° C. Sample pellets for evaluation were obtained under these conditions.

(Examples 2-14, Comparative Examples 1-3)
Sample pellets for evaluation were obtained in the same manner as in Example 1 except that the types and amounts of the raw materials were changed as shown in Table 1. However, about the comparative example using polyamide 6 resin for resin, the extruder temperature is set to 280 degreeC.
The raw materials used in Examples and Comparative Examples are as follows.
High thermal conductivity inorganic compound (B)
(FIL-2): Spherical alumina powder (ASFP-20 manufactured by Denki Kagaku Kogyo Co., Ltd., thermal conductivity 32 W / m · K alone, volume average particle diameter 300 nm, electrical insulation, volume resistivity 10 ¹⁶ Ω・ Cm)
(FIL-3): Boron nitride powder (HP-40 manufactured by Mizushima Alloy Iron Co., Ltd., single body thermal conductivity 60 W / m · K, volume average particle diameter 7.0 μm, electrical insulation, volume resistivity 10 ¹⁴ Ω · cm)
(FIL-4): Spherical anhydrous magnesium carbonate powder (Sphericalized MSL manufactured by Kamishima Chemical Co., Ltd., processed by a bead mill, single body thermal conductivity 40 W / m · K, volume average particle diameter 7.0 μm, Electrical insulation, volume resistivity 10 ¹⁶ Ω · cm)
(FIL-5): Aluminum hydroxide powder (BF-083 manufactured by Nippon Light Metal Co., Ltd., single body thermal conductivity 30 W / m · K, volume average particle diameter 8.0 μm, electrical insulation, volume resistivity 10 ¹⁶ Ω · cm)
(FIL-6): natural scaly graphite powder (BF-250A manufactured by Chuetsu Graphite Co., Ltd., thermal conductivity 1200 W / m · K alone, volume average particle diameter 250.0 μm, conductivity)
(FIL-7): Carbon fiber (M60JB-6000 manufactured by Toray Industries, Inc., thermal conductivity of 250 W / m · K alone, fineness of 206 TEX, conductivity)
Other resins:
(RES-1): Polylactic acid resin (Lacia H440 manufactured by Mitsui Chemicals, Inc.)
(RES-2): Polyamide 6 resin (Unitika Nylon 6 A1020BRL manufactured by Unitika Ltd.)
Crystallization accelerator behenamide: (CRODA JAPAN, Incroslip B)
[Specimen molding]
After drying each sample pellet obtained, a flat plate having a size of 120 mm × 120 mm × thickness 3.2 mm was formed by an injection molding machine.

[Thermal conductivity]
Thermal conductivity was calculated using a 4φ sensor with a hot disk method thermal conductivity measuring device manufactured by Kyoto Electronics Industry using a 3.2 mm thick flat plate.

[density]
A 3.2 mm thick flat plate was cut into a 3 cm × 3 cm square, and the density was measured by an underwater substitution method.

[Electrical insulation]
Using a flat plate having a thickness of 3.2 mm, the volume resistivity value was measured according to ASTM D-257. When the resistance value was too low to be measured, “conductive” was displayed.

[Thin wall formability]
Using an injection molding machine, a bar-shaped test piece of 128 mm x 12.8 mm x thickness 0.8 mm was molded through a gate installed with a gate size of 4 mm x 0.8 mm on the short side of the test piece. Thin-wall moldability was evaluated by measuring the resin temperature set by the molding machine when full filling was performed without becoming a short shot. If molding was impossible even when the set resin temperature was raised above the resin decomposition start temperature, “impossible” was displayed.

[Biodegradability]
A flat plate with a thickness of 3.2 mm was cut into a dumbbell with a length of 115 mm, a width of 25 mm, and a thickness of 3.2 mm, buried in a soil with a depth of 10 cm, and after 6 months, the change in shape was observed. It was evaluated with.
○: Decomposition so that the shape cannot be confirmed Δ: A considerable part is decomposed, but the shape can be confirmed ×: Almost no change in shape, no decomposition

The respective formulations and results are shown in Table 1. From Table 1, it can be seen that the composition of this patent provides a resin composition with high thermal conductivity that is excellent in molding fluidity as compared with a composition outside the scope of this patent.

以上から本発明の熱可塑性樹脂組成物は、高熱伝導性でありながら、射出成形時の成形流動性も非常に優れている。さらには生分解性やカーボンニュートラルなどの環境適合性をも兼ね備えた、高熱伝導性熱可塑性樹脂組成物が得られることが分かる。このような組成物は電気・電子工業分野、自動車分野、などさまざまな状況で熱対策素材として用いることが可能で、かつプラスチック廃棄物の問題を解決しうるなど環境面にも貢献できることから、工業的に有用である。

As described above, the thermoplastic resin composition of the present invention is very excellent in molding fluidity at the time of injection molding while having high thermal conductivity. Further, it can be seen that a highly heat-conductive thermoplastic resin composition having both biodegradability and environmental compatibility such as carbon neutral can be obtained. Such a composition can be used as a heat countermeasure material in a variety of situations such as in the electrical / electronic industry, automobile field, etc., and can also contribute to the environment, such as solving the problem of plastic waste. Useful.

Claims (10)

General formula (1): represented by [—CHR—CH ₂ —CO—O—] (wherein R represents an alkyl group represented by C _n H _{2n + 1} , and n is an integer of 1 to 15). The (3-hydroxyalkanoate) copolymer (A) composed of a repeating unit contains a high thermal conductive inorganic compound (B) having a thermal conductivity of 10 W / m · K or more as a single unit, and obtained. A thermoplastic resin composition having high thermal conductivity, wherein the thermoplastic resin composition has a thermal conductivity of 0.8 W / mK or more. The resin composition according to claim 1, wherein the (3-hydroxyalkanoate) copolymer (A) is biodegradable. The (3-hydroxyalkanoate) copolymer (A) is a poly [(3-hydroxybutyrate)-(3 comprising (3-hydroxybutyrate) repeating units and (3-hydroxyhexanoate) repeating units. -Hydroxyhexanoate)] copolymer. 3. The resin composition according to claim 1, wherein the resin composition is a copolymer. The high thermal conductivity thermoplastic resin according to any one of claims 1 to 3, wherein the (3-hydroxyalkanoate) copolymer (A) has a weight average molecular weight Mw of 300,000 to 3,000,000. Resin composition. The constitutional ratio of the repeating unit of the [(3-hydroxybutyrate)-(3-hydroxyhexanoate)] copolymer is (3-hydroxybutyrate) unit / (3-hydroxyhexanoate) unit = 99. The resin composition according to claim 3, which is represented by / 1 to 80/20 (mol / mol). (B) is characterized by being one or more highly thermally conductive inorganic compounds selected from the group consisting of graphite, conductive metal powder, soft magnetic ferrite, carbon fiber, conductive metal fiber, and zinc oxide. The high thermal conductivity thermoplastic resin composition according to any one of claims 1 to 5. The high thermal conductivity according to any one of claims 1 to 5, wherein (B) is an electrically insulating high thermal conductive inorganic compound having a single thermal conductivity of 20 W / m · K or more. Thermoplastic resin composition. (B) is at least one highly thermally conductive inorganic material selected from the group consisting of boron nitride, aluminum nitride, silicon nitride, aluminum oxide, magnesium oxide, magnesium carbonate, aluminum hydroxide, magnesium hydroxide, beryllium oxide, and diamond. The highly heat-conductive thermoplastic resin composition according to claim 1, wherein the composition is a compound. (A) / (B) volume ratio in the composition of (3-hydroxyalkanoate) copolymer (A) / high thermal conductive inorganic compound (B) is in the range of 5/95 to 95/5. The high thermal conductivity thermoplastic resin composition according to claim 1, wherein the thermoplastic resin composition is high in thermal conductivity. A high thermal conductive molded body produced by injection molding of the high thermal conductive thermoplastic resin composition according to claim 1.