Abstract: A polyolefin resin composition comprising (a) 50-94% by weight of a specific polypropylene/ethylene-propylene copolymer composition, (b) 5-40% by weight of a specific ethylene/&agr;-olefin copolymer rubber and (c) 1-10% by weight of a specific hydrogenated diene block copolymer, wherein the component (a) comprises 60-95% by weight of a polypropylene component and 5-40% by weight of an ethylene-propylene copolymer component having an ethylene content of 30-80% by weight, the polypropylene component has an isotactic pentad ratio (P) of not less than 0.96 and a Mw/Mn (Q value) of not more than 6, and a ratio of the maximum melt flow rate (MFRmax) to the minimum melt flow rate (MFRmin) has the following relationship 0.

Abstract: The resin compositions of the present invention have an excellent property balance between rigidity and impact resistance and give interior automotive parts having satisfactory moldability. The compositions are especially suitable for use as interior automotive parts conforming to regulations regarding head protection against impacts.The invention provides: a polyolefin resin composition comprising 78 to 87% by weight specific high-rigidity polypropylene/propylene-ethylene block copolymer, 12 to 17% by weight ethylene-(higher .alpha.-olefin) copolymer rubber, and 1 to 5% by weight hydrogenated diene block copolymer; and a molding resin composition obtained by incorporating, into the above resin composition, talc in an amount of 20 to 25% by weight based on the total weight of the composition and one or more optional additives.

Abstract: A catalyst component for producing highly crystalline olefin polymers without causing any operational problems and stably and affording therefrom a film having very few occurrence of voids and a superior transparency, and a process for producing the catalyst component, which catalyst component comprises a linear olefin-non-olefin block copolymer having at least one linear olefin block copolymer and at leaast one non-linear olefin polymer block and (a) a titanium trichloride composition or (b) titanium, magnesium, a halogen and an electron donor as components for a carrier, the content of the linear olefin polymer block being 0.1 to 49.5% by weight, the content of the non-linear olefin polymer block being 0.01 to 49.5% by weight, the ratio by weight of the linear olefin polymer block to the non-linear olefin polymer block being 2/98 to 98/2 and in the case of (a), the content of the titanium trichloride composition being 99.89 to 1.0% by weight.

Abstract: A process for producing a highly transparent and highly stiff polypropylene affording a superior molded product is provided,which process comprises using a catalyst obtained by combining1 a titanium trichloride composition (III) obtained by reacting TiCl.sub.4 with an organoaluminum compound (A.sub.1) or a reaction product (I) or (A.sub.1) with an electron donor (B.sub.1) to obtain a solid product (II), followed by subjecting the product (II) to a multi-stage polymerization treatment with a linear olefin and a non-linear olefin, each once or more times used, and further reacting the resulting linear olefin-non-linear olefin block copolymer with an electron donor (B.sub.2) and an electron acceptor,2 an organoaluminum compound (A.sub.2); and as a third component,3 an aromatic carboxylic acid ester (E) or an organosilicon compound (S) having a Si--O--C bond and/or a mercapto group.