Other

Toyota Jidosha Kabushiki Kaisha

Japan Polychem Corporation

Grand Polymer Co., Ltd.

Masatoshi Matsuda

Hisayuki Iwai

Takayuki Nagai

Takao Nomura

Yuji Fujita

Mitsuhiro Murayama

Osamu Kito

Mikio Hashimoto

Masaru Nakagawa

Ikunori Sakai

Susumu Kanzaki

Hironari Sano

Kenichi Ohkawa

Yukihito Zanka

Yutaka Obata

Moriyasu Shimojo

Koki Hirano

Yasuhisa Sugita

Kunio Iwanami

Akira Kobayashi

A thermoplastic composition which is obtained by melt-kneading (1) 55 to 75 wt. % crystalline polypropylene resin together with (2) 10 to 30 wt. % elastomer comprising either a rubber containing a vinyl aromatic compound or a mixture thereof with an ethylene/&agr;-olefin random copolymer rubber and (3) 15 to 25 wt. % talc having an average particle diameter of 3 &mgr;m or smaller. The composition satisfies specific requirements with respect to: the long period obtained by X-ray small-angle scattering attributable to the vinyl aromatic-containing rubber in a blend obtained by melt-kneading the ingredients (1) and (2); the shape and diameter of the elastomer particles present near the polypropylene/elastomer interface in the blend; and the difference between the glass transition point of the ingredient (1) and that of the composition attributable to the crystalline polypropylene homopolymer parts. The composition has a satisfactory balance between impact resistance and rigidity and has excellent injection moldability.

Thermoplastic resin composition and injection-molded object thereof

The present invention provides a resin composition high in melting flow, exhibiting good properties, excellent in moldability and shrinkage properties, and hence suitable for automobile exteriors, by including (A) propylene/ethylene block copolymer having a melt flow rate (MFR) of 100 to 200 g/10 min., its propylene homopolymer component having an MFR of 210 to 400 g/10 min. and isotactic pentad fraction of 0.98 or more, and its copolymer portion containing propylene at 65 to 85% by weight; 50 to 70% by weight, (B) ethylene/octene and/or ethylene/butene random copolymer; 10 to 25% by weight, (C) styrene-based hydrogenated block copolymer rubber; 4 to 9% by weight and (D) talc; 16 to 24% by weight.

Propylene resin composition excellent in moldability and physical properties

There are disclosed a polypropylene composition for automotive parts which has a melt index at 230&deg; C. and at 2.16 kgf of at least 30 g/10 minutes and which comprises 55 to 60% by weight of (1) propylene/ethylene block copolymer; 20 to 25% by weight of (2) rubber comprising a styrene/ethylene/propylene/styrene block copolymer and/or a styrene/ethylene/1-butene/styrene block copolymer and an olefinic elastomer; and 18 to 23% by weight of (3) talc, and also an automotive part which comprises the above polypropylene composition.

Polypropylene compositions for automotive parts

This invention provides polypropylene resin compositions which have sharply improved balance of physical properties in comparison with the related polypropylene materials, are materials that can be used in both interior and exterior parts of automobiles, have excellent thin-wall moldability and can sharply reduce generation of flow marks. Particularly, it provides a polypropylene resin composition which comprises specified amounts of (A) a specified ethylene-propylene block copolymer, (B) a specified thermoplastic elastomer and (C) talc, wherein it has specified values of physical properties measured by ASTM and has a degree of b-axis orientation of 720 or more which is calculated from the ratio of differential peak intensities measured by wide-angle X-ray diffraction of the central area of an ASTM No. 1 dumbbell prepared by injection molding.

Polypropylene resin composition

A crystalline propyleiie block-copolymer composition exhibiting superior flowability upon molding for use in automobile parts, which composition comprises 41 to 71% by weight of a crystalline propylene block-copolymer composed of a propylene homopolymer portion (Fp) and an ethylene/propylene random copolymer portion (Fc) and having an ethylene content of 1 to 10% by weight and a melt flow rate (MFR) of 20 to 100 g/10 min.; 12 to 22% by weight of a first hydrogenated product of a block-copolymer having a relatively smaller stylene content; 2 to 12% by weight of a second hydrogenated product of a block-copolymer having a relatively greater stylene content; and 15 to 25% by weight of talc, wherein the propylene homopolymer portion (Fp) contains 20 to 50% by weight of a low molecular weight propylene homopolymer having an MFR of 400 to 1,000 g/10 min., the average MFR being 100 to 350 g/10 min. and the isotactic pentad fraction being at least 98%, and wherein the said (Fc) has an intrinsic viscosity of 7 dl/g or higher.

Crystalline propylene block-copolymer composition for use in automobile

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Toyota, Japan

Masatoshi Matsuda