| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polypropylene resin compsn. which is excellent in moldability, is easily molded into thin-walled large-size items, and gives molded items excellent in mechanical properties and scratch resistance by using a crystalline PP as the main ingredient and specifying the degree of b-axis orientation obtd. from the diffration peak strength ratio by wide-angle X-ray diffraction. SOLUTION: This compsn. mainly comprises a crystalline PP and its degree of b-axis orientation obtd. from the diffraction peak strength ratio by wide-angle X-ray diffration near at the center of an ASTM No.1 dumbbell specimen is 720 or higher. Pref., this compsn. comprises a crystalline PP, a thermoplastic elastomer (e.g. a styrene-ethylene-butylene block copolymer), and talc and has such mechanical properties (measured by ASTM) as a bending modulus of 1.800 MPa or higher, a tensile yield strength of 20 MPa or higher, an Izod impact strength at 23 deg.C of 180 J/m or higher, an Izod impact strength at -30 deg.C of 30 J/m or higher, a Rockwell hardness of 74 or higher, a heat distortion temp. (HDT, 18.5 kg) of 73 deg.C or higher, a brittle point of -20 deg.C or lower, and an MFR of 30±10 g/10 min.
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