Polypropylene resin compositions and interior automotive trim parts

A polypropylene resin composition comprising

• (a) 50-80% by weight of a mixture of polypropylene and an ethylene-propylene copolymer,
• (b) 5-40% by weight of an ethylene/.alpha.-olefin copolymer rubber,
• (c) 1-10% by weight of a hydrogenated diene block copolymer, and
• (d) 10-30% by weight of talc,
• each % by weight being based on the total weight of the resin composition, wherein the mixture of polypropylene and ethylene-propylene copolymer (a) has a melt flow rate of 10-300 g/10 min under the conditions of a temperature of 230.degree. C. and a load of 2.16 kg and comprises 60-95% by weight of a polypropylene component and 5-40% by weight of an ethylene/propylene copolymer component, the polypropylene component has a melt flow rate of 100-1,000 g/10 min under the conditions of a temperature of 230.degree. C. and a load of 2.16 kg and a C.sub.f value of not more than 0.5 and the ethylene-propylene copolymer component has an ethylene content of 30-80% by weight;
• the ethylene/.alpha.-olefin copolymer rubber (b) is a copolymer of ethylene and an .alpha.-olefin of 4 or more carbons, has an ethylene content of 25-90% by weight and contains a polyethylene crystal having a long period of 6-14 nm as determined by a small angle X-ray scattering;
• and the hydrogenated diene block copolymer (c) is a A--B or A--B--A block copolymer wherein a A segment is 1,4-polybutadiene block and a B segment is a 1,2-polybutadiene block, a polyisoprene block or a butadiene/isoprene copolymer block, and wherein not less than 85% of the unsaturated bonds are hydrogenated.