Patent ID: 6245705
Filing Date: 2001-06-12
Classification: B01J,C08F,Y10S

Abstract:
A process for preparing supported alpha-olefin polymerization catalyst compositions which comprises the steps of:(i) providing silica which is porous and has a particle size of 1 to 200 microns, having pores which have an average diameter of 50 to 500 Angstroms and having a pore volume of 0.5 to 5.0 cc/g; and impregnating said silica with at least one metallocene compound of the formula CP.sub.m M(R.sup.1).sub.n (R.sup.2).sub.p whereinCp is a cyclopentadienyl or a substituted cyclopentadienylgroup; m is 1 or 2; M is a metal selected from the groupconsisting of titanium, zirconium and hafnium; andeach of R.sup.1 and R.sup.2 is selected from the group consisting of ahalogen atom, a hydrogen atom and an alkyl group,provided that m+n+p is equal to the valence of themetal M; thereby to Provide an impregnated catalystprecursor (1); andii) combining the impregnated catalyst precursor (1) with a combination of:(2) an inorganic aluminum compound Al(OH).sub.x O.sub.y, wherein x is a number from 0 to 3, wherein x+2y=3, and(3) trimethylaluminum,wherein Al(OH).sub.x O.sub.y is used in an amount sufficient to provide an Al(OH).sub.x O.sub.y :metallocene molar ratio of 5 to 10,000,wherein trimethylaluminum is used in an amount sufficient to provide a trimethylaluminum:metallocene molar ratio of 50 to 10,000, andwherein the two aluminum compounds, (2) and (3), are used in amounts to provide a molar ratio of trimethylaluminum to Al(OH).sub.x O.sub.y in the range of from 0.1 to 100.