Process for producing propylene copolymer

摘要

A process for producing a propylene copolymer having improved transparency and rigidity, which comprises carrying out (A) the polymerization of a vinyl cycloalkane having at least 6 carbon atoms and (B) the polymerization of propylene either alone or with ethylene in a multiplicity of steps in the presence of a catalyst system composed of a titanium compound and an organoaluminum compound. The content of the vinyl cycloalkane unit in the resulting copolymer is 0.05 to 10,000 weight ppm.