| abstract |
A process for polymerizing or copolymerizing α-olefins in the presence of a catalyst composed of (A) a mechanically pulverized solid titanium-containing catalyst component and (B) an organometallic compound of a metal of Groups I to III of the periodic table, wherein said titanium-containing component is a solid halogen-containing titanium catalyst component obtained by reacting a mechanically copulverized solid product in the absence of mechanical pulverization with a titanium compound which is liquid under the reaction conditions, said mechanically copulverized product being derived from (1) a magnesium compound, (2) an organic acid ester, and (3) an active hydrogen-containing compound selected from the group of alcohols and phenols; and a catalyst composition used therefor. |