Sumitomo Chemical Company, Limited

Kenichi Okawa

Tsuyoshi Watanabe

Moriyasu Shimojo

Disclosed are a polypropylene-based resin composition comprising (i) a resin composition comprising specific amounts of a propylene-ethylene block copolymer (A-1), a copolymer rubber of ethylene and &#x3b1;-olefin having from 3 to 20 carbon atoms (B), the copolymer rubber having a density of from 0.85 to 0.885 g/cm, an inorganic filler (C), and optionally a propylene homopolymer (A-2), and (ii) a small amount of an fatty acid amide (D). The resin composition is excellent in balance between rigidity and impact resistance and in scratch resistance.

Polypropylene-based resin composition and injection molded article comprising the same

Disclosed is a thermoplastic resin composition comprising (A) 35 to 85% by weight of a polypropylene resin, (B) 10 to 35% by weight of an elastomer, (C) 2 to 30% by weight of an inorganic filler and (D) 5 to 15% by weight of a resin, wherein the resin (D) has a melt tension (MT), measured at a winding speed of 15.7 m/min, of not less than 0.03 N and less than 0.1 N and a swelling ratio (SR), measured at 220&deg; C., an L/D of an orifice of 40 and a shear rate of 1.2&times;10 sec , of 1.8 or more, and the time required for the resin (D) until the ratio (G(t)/G(0.02)) of the relaxation elastic modulus G(t) measured at 210&deg; C. to the relaxation elastic modulus G(0.02) in a time of 0.02 second reaches 0.01 is not less than 5 seconds and less than 10 seconds.

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Ichihara, Japan

Kenichi Okawa