FORFARANDE FOR FRAMSTELLNING AV ETENSAMPOLYMERER MED ANVENDNING AV ETT KATALYSATORSYSTEM OMFATTANDE EN PREKURSORKOMPOSITION OCH EN BLANDNING AV ORGANOALUMINIUMFORENINGAR

摘要

Ethylene copolymers having improved optical properties in film form are prepared by continuously copolymerizing ethylene with one or more higher alpha olefin monomers in a low pressure gas phase reaction with a catalyst composition prepared by forming a precursor composition from a magnesium compound, titanium compound, and electron donor compound; diluting said precursor composition with an inert carrier material; optionally partially activating the diluted precursor composition with an organo aluminum compound prior to introducing said diluted precursor composition into the polymerization reactor; and completely activating the diluted (and optionally partially activated) precursor composition in the polymerization reactor with a mixture of a dihydrocarbyl aluminum halide compound and a trihydrocarbyl aluminum compound.