| 摘要 |
PURPOSE: To prepare in a high activity a propylene block copolymer which has high tacticity and m.p. and excellent rigidity and impact resistance. CONSTITUTION: Polymn. of propylene or propylene and anotherα-olefin is conducted in the 1st stage in the presence of a catalyst comprising (A) a titanium-contg. solid catalyst component, (B) an organoaluminum compd., and (C) an organosilicon compd. component represented by the formula R<1> 2 Si(OR<2> )2 (R<1> represents a cyclic amino group and R<2> represents 1-10C hydrocarbon residue), and gas-phase polymerization of propylene with anotherα-olefin is subsequently conducted in the 2nd stage without inactivating the catalyst system.
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