| abstract |
The present invention relates to a silica supported magnesium-containing catalytic precursor of reduced SiOH content for reaction with a titanium halide to form a catalyst for the production of a stereospecific alpha olefin polymer characterized in that prior to reacting with titanium halide the magnesium-containing silica is reacted with at least one titanium compound having the formula Ti(R)nXm or Ti(OR)nXm where R is aryl, alkyl, alkaryl, or mixtures thereof; X is halogen; n is an integer of 1 to 4, and m is 0 or an integer of 1 to 3 with the provision that the sum of n and m is 4. It also relates to preparing the catalyst from the precursor. |