Passivated supports for use with olefin polymerization catalysts

摘要

A phosphinimine catalyst immobilized on a passivated inorganic oxide support, had high activity at low co-catalyst concentrations and gave, under gas phase polymerization conditions, ethylene copolymer with a high molecular weight. A method of making a passivated silica support involves treatment of silica with an organoaluminum compound, a diorganomagnesium compound and a source of chloride (to make MgCl2) under anhydrous conditions and in the absence of polar solvents.

主权项

1. An olefin polymerization process comprising contacting ethylene and at least one alpha-olefin with an olefin polymerization catalyst, said olefin polymerization catalyst comprising: a passivated support, a group 4 single site catalyst and a cocatalyst; wherein the passivated support comprises silica which has been treated with i) an organoaluminum compound and ii) magnesium chloride, wherein the magnesium chloride is generated by addition of a diorganomagnesium compound and a source of chloride to the organoaluminum treated silica, provided that the source of chloride is not a transition metal chloride; and wherein said passivated support is prepared in the non-polar hydrocarbon solvent or diluent.