Mitsubishi Chemical Corporation

Mitsubishi Petrochemical Company Limited

Japan Polychem Corporation

Masahide Hamaura

Yoshihiro Sobajima

Akira Yamaji

Masashi Shimouse

Etsushi Akashige

Takeshi Hiramatsu

Itsushi Imamura

Satoru Kinoshita

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 containing talc, comprising the following components (a), (b) and (c) is provided: (a) 100 parts by weight of a propylene/ethylene block copolymer containing a crystalline propylene homopolymer part (Unit A part) and an ethylene/propylene random copolymer part (Unit B part); (b) 0.1 to 80 parts by weight of talc having an average particle size of 1.5 to 20 microns and an average aspect ratio of not less than 4; and (c) 2 to 80 parts by weight of an ethylene/.alpha.-olefin copolymer polymerized by using a metallocene catalyst, and containing an .alpha.-olefin having 3 to 16 carbon atoms. This composition has good paintability, molding processability (fluidity) and excellent mechanical strength balance, and is useful for a material for e.g., automobile parts.

Propylene resin compositions containing talc

There is provided a heat-resistant, propylene resin-based molding material, comprising the following components (A) and (B):

Heat-resistant, propylene resin-based molding materials and molded

A process for producing a molded product of propylene resin which includes melting and kneading at least a part of the following component (a), adding to the resulting melt the following component (b) or the component (b) and the remainder of the component (a) and kneading the resulting mixture to prepare a resin composition having a melt flow rate of 1 to 100 g/10 min, and then molding the resin composition into a molded product in which the breakage rate of the component (b) is 30% by weight or less: (a) 100 parts by weight of a crystalline propylene polymer having a melt flow rate of 1 to 300 g/10 min and (b) 3 to 80 parts by weight of a filler in the form of hollow particles having a mean particle density (true density) of 0.1 to 0.9 g/cm.sup.3, as measured according to ASTM-D2840, a mean particle diameter of 7 to 100 .mu.m and a 10%-by-weight breakage pressure resistance of 100 kg/cm.sup.2 or more, as measured according to ASTM-D3102.

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Yokkaichi, Japan

Masahide Hamaura