COMPOSIÇÃO DE CATALISADOR E PROCESSO DE POLIMERIZAÇÃO

摘要

A catalyst composition for the polymerization of propylene is provided. The catalyst composition includes one or more Ziegler-Natta procatalyst compositions having one or more transition metal compounds and one or more esters of aromatic dicarboxylic acid internal electron donors, one or more aluminum containing cocatalysts and a selectivity control agent (SCA). The SCA is a mixture of an activity limiting agent and a silane composition. The catalyst composition has a molar ratio of aluminum to total SCA from 0.5:1 to 4:1. This aluminum/SCA ratio improves polymerization productivity and the polymer production rate. The catalyst composition is self-extinguishing.