摘要 |
PROBLEM TO BE SOLVED: To produce a polypropylene, having a high stereoregularity, improved in ridigity and useful as a molding product, etc., by polymerizing propylene in the presence of a specific catalyst. SOLUTION: Propylene is polymerized in the presence of a catalyst comprising (A) a solid Ti catalyst component prepared by prepolymerizing an olefin in the presence of a solid Ti compound component obtained by bringing a solid Ti compound containing Mg, tetravalent Ti, a halogen and an electron donor into contact with an organoaluminum halide compound represented by formula I [R is a 1-10C saturated hydrocarbon; X is a halogen; (n) is 0<(n)<3] and an organosilicon compound represented by formula II (R<1> to R<3> are each a 1-20C hydrocarbon) and an organoaluminum compound without any halogen atom, (B) an organoaluminum compound such as trimethylaluminum and (C) the organosilicon compound represented by formula II to afford a polypropylene. |