Patent ID: 7718735

Claim:
A polypropylene resin composition comprising: from 50 to 94% by weight of a polypropylene resin (A), from 1 to 25% by weight of an ethylene-α-olefin copolymer rubber (B) which includes units of α-olefin having 4-12 carbon atoms and ethylene units and has a density of from 0.850 to 0.870 g/cm 3 and a melt flow rate, as measured at a temperature of 230° C. and a load of 2.16 kgf, of from 0.05 to 1 g/10 min, and from 5 to 25% by weight of an inorganic filler (C), provided that the overall amount of the polypropylene resin composition is 100% by weight, wherein the polypropylene resin (A) comprises a propylene-ethylene block copolymer (A-1) satisfying requirements (1), (2), (3) and (4) defined below or a polymer mixture (A-3) comprising the propylene-ethylene block copolymer (A-1) and a propylene homopolymer (A-2), and the polypropylene resin (A) further comprises a propylene-ethylene block copolymer (A-4) having a propylene-ethylene random copolymer portion, wherein the propylene-ethylene random copolymer portion included in the aforesaid block copolymer (A-4) has an intrinsic viscosity [η] EP-A-4 of from 2 to 3 dl/g, requirement (1): the block copolymer (A-1) is a propylene-ethylene block copolymer comprising from 55 to 90% by weight of a polypropylene portion and from 10 to 45% by weight of a propylene-ethylene random copolymer portion, provided that the overall amount of the block copolymer (A-1) is 100% by weight, requirement (2): the polypropylene portion of the block copolymer (A-1) is a propylene homopolymer or a copolymer comprising propylene units and 1 mol % or less of units of a comonomer selected from the group consisting of ethylene and α-olefin having 4 or more carbon atoms, provided that the overall amount of units constituting the copolymer is 100 mol %, requirement (3): the weight ratio of the propylene units to the ethylene units in the propylene-ethylene random copolymer portion of the block copolymer (A-1) is from 70/30 to 50/50, requirement (4): the propylene-ethylene random copolymer portion of the block copolymer (A-1) has an intrinsic viscosity [η] EP-A-1 of from 4.5 dl/g to 5.3 dl/g, and the propylene resin composition further comprises an aromatic vinyl compound-containing rubber having a molecular weight distribution of 2.5 or less, as determined by GPC.