Patent ID: 7329714
Filing Date: 2008-02-12
Classification: C08F,Y10S

Abstract:
1. A method of polymerizing propylene comprising the following steps: pre-polymerizing propylene or 4-methyl-1-pentene with a Ziegler-Natta catalyst in the presence of dicyclopentyldimethoxysilane at the reaction temperature of 0 to 40° C. in the reaction time of 0.5 to 5 hours; and polymerizing propylene with the pre-polymerized Ziegler-Natta catalyst wherein the Ziegler-Natta catalyst contains a titanium compound comprising elements of family 4, family 5 or family 6 of the periodic table, and an aluminum compound, and when propylene is pre-polymerized with a Ziegler-Natta catalyst, the ratio of Al to Si is 1:10; and when 4-methyl-1-pentene is pre-polymerized with a Ziegler-Natta catalyst, the ratio of Al to Si is 0.1:1.