Optimum molar ratio of co-catalyst to external electron donor in propylene polymerization.

摘要

This invention is for a process for the polymerization of propylene to a minimum level of xylene solubles by use of the molar ratio of co-catalyst to external electron donor (selectivity control agent). Using a conventional supported heterogeneous Ziegler-Natta catalyst component with an trialkyl aluminum co- catalyst and an cycloalkylalkyldialkoxysilane external electron donor (selectivity control agent) in a Al/Si molar ratio of about 2 results in the minimum amount of xylene solubles.