Patent ID: 6255390
Filing Date: 2001-07-03
Classification: C08L

Abstract:
A polyolefin resin composition comprising:(A) 99.about.80% by weight of a propylene block copolymer,wherein said block copolymer consists of a propylene homopolymer component and an ethylene-propylene copolymer component, and wherein a product of an intrinsic viscosity ratio of said copolymer component to said homopolymer component and a weight ratio of said homopolymer component to said copolymer component is within a range of((.eta..sub.RC /.eta..sub.PP).times.(W.sub.PP /W.sub.RC))=0.2.about.3.0,wherein the intrinsic viscosity of said homopolymer component and said copolymer component being .eta..sub.PP and .eta..sub.RC, respectively, and a weight content (%) of said homopolymer and said copolymer component being W.sub.PP and W.sub.RC, respectively, and having a ratio of a melt flow rate of said copolymer component (MFR.sub.RC) to a melt flow rate of said homopolymer (MFR.sub.PP) component within a range of(MFR.sub.RC /MFR.sub.PP)=0.3.about.4.0,a ratio of the intrinsic viscosity of said copolymer component to said homopolymer component is within a range of.eta..sub.RC /.eta..sub.PP =0.7.about.1.2,and wherein .eta..sub.RC is 6.5 or less, W.sub.RC is within a range of 22-70% by weight and the ethylene content of said copolymer component is within the range of 25-55% by weight; and(B) 1.about.20% by weight of an olefin or styrene elastomer,wherein a ratio of a melt flow rate of said olefin or styrene elastomer (MFR.sub.R) to that of said homopolymer component (MFR.sub.PP) in said propylene block copolymer (A) is within a range of(MFR.sub.R /MFR.sub.PP)=0.3.about.4.0,and a ratio of an intrinsic viscosity of said olefin or styrene elastomer .eta..sub.R to that of the homopolymer component .eta..sub.PP in said propylene block copolymer (A) is within a range of.eta..sub.R /.eta..sub.PP =0.7.about.1.2.