Catalyst for the polymerization of olefins

Claim 1

An improved catalyst for the polymerization and copolymerization of ethylene in the presence of hydrogen as a molecular weight control agent consisting essentially of (1) a composition prepared by combining a compound of vanadium with an alkylaluminum alkoxide of the formula R n Al(OR).sub. 3-n wherein R is a hydrocarbyl group containing from 1 to 12 carbon atoms and n varies from 0.5 to 2 inclusive and mixtures of such compounds, and thereafter combining the resulting reaction mixture with a trialkylaluminum, the molar ratio of said trialkylaluminum to said compound of vanadium being in the range from 0.3:1 to 1000:1 and said alkoxide-to-vanadium molar ratio being in the range from 1:10 to about 100:1, and (2) a support on which said composition is deposited consisting of silica gel which has been reacted with an alkylaluminum compound chosen from the group consisting of (1) R n AlX.sub. 3-n wherein R is an alkyl radical having from 1 to 12 carbon atoms, X is a halogen and n is 1, 2 or 3 and mixtures thereof and (2) compounds of the formula R n Al(OR).sub. 3-n wherein R is an alkyl radical having from 1 to 12 carbon atoms and n is 1 or 2 and mixtures thereof.