US 5,334,567 AGranted

Cocatalyst for vanadium-containing ethylene polymerization catalyst

AssigneeQuantum Chemical Corporation

InventorsRaghu Menon, Albert P. Masino, Mark K. Reinking

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Abstract

The present invention is directed to a novel halosilane cocatalyst component which may be used in conjunction with an aluminum-containing cocatalyst to provide enhanced catalytic activity of a vanadium based solid catalyst component in the polymerization of .alpha.-olefins. In addition to the enhancement in the catalytic activity obtaining using the present catalyst system, the resultant polymer produced by the present invention exhibits improved physical properties compared with polymers produced by prior art vanadium based catalyst systems. Thus, the catalyst system of the instant invention represents an advance in the art in view of the combination of increased catalytic activity, i.e. yield of polymer produced, and enhanced physical properties of the polyolefin produced. In accordance with the present invention, a catalyst system is provided which comprises a solid catalyst component and a halosilane cocatalyst component. The solid catalyst component of the present invention is the product formed by admixing a solid inorganic oxide, an organometallic compound, a vanadium-containing compound and an organic reagent. In another aspect of the present invention, a process of the polymerization of .alpha.-olefins is disclosed. In this process at least one olefin is polymerized under olefin polymerization catalyst utilizing the catalyst system of the present invention, which includes the solid catalyst component of the present invention, and a cocatalyst selected from the group consisting of halosilane compounds and admixtures thereof with aluminum compounds.

Claims16

Dependent claims

An improved catalyst system for polymerizing .alpha.-olefins consisting essentially of a silica supported vanadium based solid catalyst component prepared by the steps of:

(a) pretreating silica support to remove surface hydroxyl groups;
(b) slurrying said pretreated silica with a hydrocarbon solvent;
(c) contacting said slurried silica with an organometallic compound having the formula:
R.sub.x MR'.sub.y R".sub.z
wherein M is a metal of Group IIIA of the Periodic Table of Elements, R is an alkyl group containing 1 to 12 carbon atoms, R' and R" are independently hydrogen, halide, alkyl or alkoxy groups containing from 1 to 12 carbon atoms, x is an integer from 1 to 3, and y and z are 0 or an integer from 1 to 2, the sum of which is not greater than 3-x;
(d) contacting said product of step (c) with a vanadium compound having the formula:
V(OR).sub.x (O).sub.y (X.sup.2).sub.z
wherein X.sup.2 is a halogen, R is a saturated hydrocarbon having from 1 to about 18 carbon atoms, x=0 or an integer from 1 to 5, y=0 or 1, and z=(5-x-2y) or 4 or 3 when x=0, y=0, or mixtures of such vanadium compounds;
(e) reacting said product of step (d) with an organic reagent selected from the group consisting of alcohols, ethers, carbonates, amines, and phosphorous compounds;
and
(f) adding an alkylaluminum first cocatalyst component, and at least one halosilane second cocatalyst component having the formula R.sub.f.sup.8 SiX.sub.g.sup.3 where X.sup.3 is halogen;
R.sup.8 is hydrogen, alkoxy, alkyl, aryl, silyoxy or cycloalkyl;
f is 0 or an integer from 1 to 3, and g is an integer from 1 to 4 with the proviso that the sum of f and g is 4, to the silica supported vanadium based solid catalyst component during polymerization of said .alpha.-olefin.

10 more elements

Dependencies are inferred from the claim text.