Patent ID: 6156836
Filing Date: 2000-12-05
Classification: C08L

Abstract:
A polypropylene resin composition which comprises:(A) 54 to 65% by weight of a crystalline ethylene-propylene block copolymer having a melt flow rate (MFR) of from 60 to 120 g/10 minutes, wherein the crystalline ethylene-propylene block copolymer comprises a homopolypropylene moiety and an ethylene-propylene copolymer moiety, wherein the homopolypropylene moiety has an isotactic pentad fraction value of 96% or more and an MFR value of from 150 to 250 g/10 minutes and the ratio of the ethylene-propylene copolymer moiety is from 5 to 10% by weight based on the total of the homopolypropylene moiety and the ethylene-propylene copolymer moiety;(B) 17 to 24% by weight of a thermoplastic elastomer comprising at least one styrene-ethylene.butylene-styrene block copolymer; and(C) 15 to 25% by weight of talc,wherein the propylene resin composition has the following mechanical properties when measured in accordance with the procedures of ASTM:modulus in flexure.gtoreq.1,800 MPa;tensile yield strength.gtoreq.20 MPa;Izod impact strength at 23.degree. C..gtoreq.180 J/m;Izod impact strength at -30.degree. C..gtoreq.30 J/m;Rockwell hardness (R scale).gtoreq.74;heat distortion temperature (HDT, 18.5 kg).gtoreq.73.degree. C.;brittleness temperature.ltoreq.-20.degree. C.; andMFR=30 to 60 g/10 minutes, andwherein the propylene resin composition has a degree of b-axis orientation of 720 or more which is calculated from the ratio of differential peak intensities by wide-angle X-ray diffraction of the central area of an ASTM No. 1 dumbbell prepared by injection molding.