| abstract |
According to the present invention, there is provided a process for preparing polyolefins by polymerizing or copolymerizing olefins in the presence of a catalyst consisting of a solid component and an organometallic compound component, characterized in that said solid component is obtained by copulverizing n (1) a magnesium halide and/or a manganese halide, n (2) an aromatic hydrocarbon, n (3) a tetravalent titanium compound, and n (4) a trivalent titanium compound n And in that said organometallic compound component is a mixture of n (5) a trialkylaluminum and n (6) a compound represented by the general formula AlR n X 3-n wherein R is alkyl having 1 to 10 carbon atoms and may be the same or different, X is halogen and O<n<3. |