Catalytic system which can be used for the stereospecific polymerisation of alpha-olefins, process for this polymerisation 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.