| abstract |
Highly stereoregular polymers or copolymers of alpha -olefins containing at least 3 carbon atoms are prepared in high yields by polymerizing or copolymerizing the alpha -olefins in the presence of a catalyst composed of (a) an improved solid transition metal catalyst component prepared by reacting (1) a magnesium-containing reaction product derived from a member of the group consisting of (i) a magnesium halide, (ii) an active hydrogen-containing compound, (iii) an organic acid ester and (iv) a silicon or tin compound containing at least one halogen atom or hydrocarbon group bonded directly to silicon or tin with (2) a titanium compound, and (b) an organometallic compound of a metal selected from aluminum, magnesium and zinc. |