Nissan Motor Company Limited

Japan Polychem Corporation

Japan Polypropylene Corporation

Masashi Shimouse

Yukihito Zanka

Takayuki Sato

Yoshihiro Sobajima

Mineyuki Saotome

Sinichi Takaragi

Shigeo Mizukami

Masahide Hamaura

Yuji Ryosho

Hironari Fujii

Akira Yamaji

Ken Shimizu

A moldability modifier capable of improving molding processability, and a polypropylene resin composition using the same suitable for automobile exterior parts are provided. The invention relates to a moldability modifier comprising propylene block copolymer (A) containing from 80 to 98 wt % of a propylene homopolymer portion (A1) and from 2 to 20 wt % of a propylene/ethylene random copolymer portion (A2), wherein the MFR of (A1) is 300 g/10 min or more, the ethylene content of (A2) is from 10 to 70 wt %, the [&#x3b7;] of (A2) is 6.5 dl/g or more, and the MFR as a whole is 40 g/10 min or more; and propylene block copolymer (B) containing from 20 to 79 wt % of a propylene polymer portion (B1) and from 21 to 80 wt % of a propylene/ethylene random copolymer portion (B2), wherein the MFR of (B1) is 20 g/10 min or more, the ethylene content of (B2) is from 20 to 70 wt %, the [&#x3b7;] of (B2) is from 2.5 to 9.0 dl/g, and the MFR as a whole is from 0.1 to 50 g/10 min; and a polypropylene resin composition using the same.

Moldability modifier and polypropylene resin composition using the same

A polypropylene resin composition contains 2 to 15 wt % of a moldability improver (A) and 85 to 98 wt % of a polypropylene resin (B). The moldability improver (A) is formed of propylene block copolymers (A-1) and (A-2). Each of the propylene block copolymers (A-1) and (A-2) has a crystalline propylene polymer component (A-11), (A-21) and a propylene-ethylene random copolymer component (A-12), (A-22). The propylene block copolymer (A-1) is characterized in that the melt flow rate of the crystalline propylene polymer component (A-11) is high, whereas the propylene block copolymer (A-2) is characterized in that the content ratio of the propylene-ethylene random copolymer component (A-22) is high. The polypropylene resin (B) is formed of a propylene-ethylene block copolymer (B-1), at least one of an ethylene elastomer and a styrene elastomer (B-2) and an inorganic filler (B-3).

Polypropylene resin composition, resin molded part and production method thereof

A propylene resin composition having excellent physical property balance (heat resistance and impact strength at low temperature), and excellent injection molding processability as well as excellent paintability is provided, which propylene resin composition comprises component (a): a propylene-ethylene block copolymer comprising 85-95% by weight of a crystalline polypropylene homopolymer portion (unit A) and 5-15% by weight of an ethylene-propylene random copolymer portion (unit B) having an ethylene content of 30-60% by weight, the melt flow rate of the total component (a) being 50-500 g/10 min in an amount of 100 parts by weight, component (b): talc having an average particle diameter of 1.5-10 .mu.m and an average aspect ratio of 4 or more in an amount of 10-60 parts by weight, and component (c): an ethylene-1-octene copolymer comprising 20-50% by weight of 1-octene, and having a density of 0.86-0.89 g/cm.sup.3 and a tensile strength at break of 10 MPa or more in an amount of 10-60 parts by weight.

Propylene resin compositions

A propylene resin composition having suitability to coating is disclosed which comprises (a) 100 parts by weight of a propylene-ethylene block copolymer comprising 60 to 95% by weight of a crystalline polypropylene unit and 5 to 40% by weight of an ethylene-propylene random copolymer unit, (b) 2 to 120 parts by weight of an ethylene-.alpha.-olefin copolymer obtained by polymerization using a metallocene catalyst, containing 20 to 65% by weight of an .alpha.-olefin having 3 to 8 carbon atoms, and having a melt flow rate of 0.5 to 40 g/10 min and a density of 0.85 to 0.90 g/cm.sup.3, (c) 0.1 to 120 parts by weight of a filler selected from talc, mica, and a fibrous filler, (d) 5 to 40% by weight of a propylene polymer having grafted thereto 0.1 to 25% by weight, based on the total polymer, of maleic anhydride or a hydroxyl-containing maleic anhydride derivative, and (e) 0 to 10% by weight of a hydroxyl-terminated diene polymer or a hydrogenation product thereof. A molded article obtained from the propylene resin composition can be coated with a melamine coating without cleaning with trichloroethane or primer coating to provide a coated article having high adhesion to the coating, appearance, and well-balanced high mechanical strength.

Propylene resin composition and coating method using the same

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Mie, Japan

Masashi Shimouse