CATALYST SYSTEM FOR STEREOSPECIFIC POLYMERIZATION OF ALPHA-OLEFINES, PROCESS FOR POLYMERIZATION USING IT AND POLYMER OBTAINED BY MEANS OF SAID PROCESS

摘要

Catalyst system usable for the polymerization of alpha -olefins, comprising: - a solid based on complexed titanium chloride of delta crystalline form; - an organoaluminium compound; - an organic oxygen compound of silicon; characterized in that the organoaluminium compound is an unhalogenated compound.