| 摘要 |
PURPOSE: To provide a propylene block copolymer which has a high m.p., a wide mol.wt. distribution, and excellent stiffness, impact strength, and moldability. CONSTITUTION: The propylene block copolymer comprises a crystalline propylene homopolymer or a crystalline copolymer of propylene with anotherα-olefin and a rubberlike copolymer of propylene with anotherα-olefin and has an m.p. of 165 deg.C or higher, a ratio (Mw /Mn ) of the wt.-average mol.wt. (Mw ) to the number-average mol.wt. (Mn ) of 10 or higher, and a content of the other olefin of 1-15wt.%.
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