Patent ID: 6194339
Filing Date: 2001-02-27
Classification: B01J,C08F

Abstract:
A catalyst system comprising(a) an ethylene polymerization catalyst prepared by steps comprising:(i) contacting a support with an organosilicon compound to effectuate reduction of surface hydroxyl group concentration of the support;(ii) contacting the support from step (i) with(A) a dialkylmagnesium compound or complex;(B) an alcohol; and(C) a transition metal compound;wherein steps (ii)(A), (ii)(B) and (ii)(C) are performed in an order selected from:(I) first (ii)(A), then (ii)(B), and then (ii)(C); or(II) first (ii)(A), then (ii)(C), and then (ii)(B); or(III) first (ii)(B), then (ii)(A), and then (ii)(C); and(iii) contacting the product of step (ii) with a Group 13 metal-containing compound selected from the group consisting of triethylborane, diethylaluminum chloride and ethylaluminum sesquichloride;(b) an aluminum-containing cocatalyst; and(c) a hydrocarbylalkoxysilane cocatalyst modifier.