POLYPROPYLENE COMPOSITION

A polypropylene composition comprising polypropylene and a rubber component and having such characteristics that: (i) the melt flow rate (MFR: 230 DEG C, under 2.16 kg load) determined according to ASTM D1238 is 8 g/10 min or above; (ii) the flexural modulus (FM) determined according to ASTM D790 is 20,000 kg/cm or above; (iii) the Izod impact strength (IZ) determined according to ASTM D256 is 20 kg.cm/cm or above; (iv) the heat deformation temperature (HDT) determined according to ASTM D648 is 135 DEG C or above; (v) the dimensions of a polypropylene microcrystal in an injection molding of the composition as determined by wide-angle X-ray diffractometry and X-ray small-angle scattering are 5-20 nm, 5-20 nm and 5 nm or above, respectively, in the directions of c-axis, a-axis and b-axis; and (vi) the rubber component is present in an injection molding of the composition as a continuous phase around the polypropylene microcrystal in the direction of injection and the direction perpendicular thereto, and the average thickness of the continuous phase ranges from 0.5 to 3 nm. This composition is excellent not only in rigidity and heat resistance but also in impact resistance and toughness.