Polymerization of olefin

Claim 1

In a process for polymerizing ethylene alone or a mixture containing ethylene and a different α-olefin to form copolymers containing less than 10 wt.% of the α-olefin in the presence of a catalyst system comprising an organoaluminum compound and a solid catalytic component, the improvement which comprises preparing said solid catalytic component by the process which comprises: (a) dissolving a vanadium trichloride-ether complex in a solvent to form a solution; (b) adding to said solution a quantity of an aluminum halide sufficient to yield a molar ratio of aluminum halide to the ether in the vanadium trichloride-ether complex of 0.1 to 10, whereby said aluminum halide reacts with said vanadium trichloride-ether complex to form a precipitate consisting essentially of said solid catalytic component; and (c) recovering said solid catalytic component.