Thermoplastic resin composition and its injection molded article

A thermoplastic resin composition comprising (A) 35 to 83.9% by weight of a polypropylene resin, (B) 10 to 35% by weight of an elastomer, (C) 2 to 30% by weight of inorganic filler, (D) 0.1% by weight or more but less than 5% by weight of a resin satisfying (Requirement 1) through (Requirement 3) defined below, and (E) 4 to 10% by weight of a resin satisfying (Requirement 4) defined below, provided that the amounts of (A), (B), (C), (D) and (E) indicated above are based on the total weight of these components:

• (Requirement 1) the resin has a melt tension (MT), measured at 190° C. at a winding rate of 15.7 m/min, of 0.1 N or more;
• (Requirement 2) the resin has a swelling ratio (SR), measured at 220° C. at an L/D ratio of an orifice of 40and at a shear rate of 1.2×103 sec−1, of 1.8 or more;
• (Requirement 3) the time required for the resin until the ratio (G(t)/G(0.02)) of a relaxation modulus G(t) measured at 210° C. to a relaxation modulus G(0.02) at a time of 0.02 sec reaches 0.01 is 10 sec or more;
• and
• (Requirement 4) with respect to the swelling ratio measured at 220° C. at an L/D of an orifice of 40, the ratio of a swelling ratio (SR103) at a shear rate of 2.4×103 sec−1 to a swelling ratio (SR102) at a shear rate of 1.2×102 sec−1, SR103/SR102, is from 1.0 to 1.1.