Control of a solution process for polymerization of ethylene

摘要

A solution process for the preparation of high molecular weight polymers of alpha-olefins selected from the group consisting of homopolymers of ethylene and copolymers of ethylene and C3-C12 higher alpha-olefins is disclosed. Ethylene and/or mixtures of ethylene and C3-C12 higher alpha-olefins are polymerized under non-isothermal conditions in a tubular reactor or in a system of reactors which operate under different conditions, in the presence of a catalytic amount of a titanium-containing coordination catalyst in an inert solvent at a temperature in excess of 105 DEG C. The improvement is characterized in that: (a) the catalyst is activated with a solution of a mixture of aluminum alkyl and alkoxy aluminum alkyl in inert solvent; and (b) the process is controlled by adjusting the ratio of aluminum alkyl to alkoxy aluminum alkyl in the mixture of (a). The aluminum alkyl is of the formula AlRnX3-n and the alkoxy aluminum alkyl is of the formula AlR'mOR''3-m, in which each of R, R' and R'' is alkyl or aryl of 1-20 carbon atoms, X is halogen, n is 2-3 and m is 0-3.