CATALYTIC SYSTEM WHICH CAN BE USED FOR THE STEREOSPECIFIC POLYMERIZATION OF ALPHA-OLEFINS, PROCESS FOR THIS POLYMERIZATION AND POLYMERS OBTAINED

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.