Patent ID: 7244794
Filing Date: 2007-07-17
Classification: C08F

Abstract:
1. A method for producing a propylene polymer by using a catalyst system for propylene polymerization, wherein the catalyst system comprises: a Ziegler-type catalyst as main catalyst component comprising magnesium, titanium, a halogen and an internal electron donor; an alkylaluminum compound as cocatalyst; and an external electron donor comprising an alkyltrialkoxysilane compound selected from the group consisting of: i-C 3 H 7 Si(OCH 3 ) 3 , i-C 4 H 9 Si(OCH 3 ) 3 , i-C 3 H 7 Si(OC 2 H 5 ) 3 i-C 4 H 9 Si(OC 2 H 5 ) 3 , i-C 5 H 11 Si(OC 2 H 5 ) 3 , i-C 3 H 7 Si(OC 3 H 7 ) 3 , i-C 4 H 9 Si(OC 3 H 7 ) 3 , and mixtures thereof.