HIGH ACTIVITY POLYETHYLENE CATALYSTS

摘要

An ethylene polymerization catalyst is prepared by impregnating a porous sup port, such as silica, with an organomagnesium compound such as a dialkylmagnesium compound, contacting the magnesium-containing sup port with a silane compound which is free of hydroxyl groups, such as tetraalkoxysilanes, e.g. tetraethyl orthosilicate, and incor porating a transition metal component, such as titanium tetrachloride, in a specific ratio to the magnesium and silane components. Activation of t his catalyst precursor with dimethylaluminum chloride as a cocatalyst results in a catalyst system which is effective for the productio n of ethylene copolymers with multimodal molecular wei ght distributions.