Alkene polymerization process and catalyst compositions therefor

摘要

Catalyst compositions enabling the production of polyalkenes with improved bulk density are prepared by combining the following catalyst components in the following order of addition: first introducing an electron donor component, then adding a reaction product of a di-alkylaluminium halide and a solid component comprising a magnesium di-halide, an electron donor and a halide of tetravalent titanium and lastly adding a tri-alkylaluminium compound.