abstract |
The particle size of as formed polyethylene or ethylene copolymer containing up to about twenty percent of a C3 to C8 olefin can be increased by using a high yield, solid catalyst component prepared from (1) a magnesium alkoxide, (2) a titanium (IV) or vanadium (V) chloride, chloroalkoxide or alkoxide, (3) an alkylaluminum compound, and (4) hydrogen chloride. The particle size of as formed polymer can be increased substantially using the hydrogen-chloride-prepared catalyst component, compared to the particle size of polymer made using a similar catalyst component prepared without the use of hydrogen chloride, when either is employed with an alkylaluminum compound promoter in a slurry or vapor phase polymerization process at moderate polymerization temperatures and pressures. |