US 4,912,075 A · Method for preparing a supported metallocene-alumoxane catalyst for gas phase polymerization

Abstract

This invention relates to a process for preparing a supported metallocene alumoxane catalyst for use in the gas phase polymerization of olefins. The invention particularly relates to the use of silica gel containing from about 6 to about 10 percent by weight adsorbed water as the catalyst support material. It has been found that such silica gel may be safely added to an aluminum trialkyl solution to form by direct reaction with the adsorbed water content of the silica gel catalyst support material the alumoxane component of the catalyst system. An alumoxane coated silica gel is formed to which a metallocene may be added and the resulting material dried to free flowing powder. The dry free flowing powder may then be used as a supported metallocene alumoxane catalyst complex for gas phase polymerization of olefins.

Claims20

Dependent claims

A process for preparing a supported metallocene alumoxane catalyst for gas phase polymerization of olefins, comprising the steps of:

(a) adding undehydrated silica gel to a stirred solution of an aluminum trialkyl in an amount sufficient to provide a mole ratio of aluminum trialkyl to water of from about 3:1 to about 1:2 and allowing the mixture to react;
(b) adding a metallocene to the reacted mixture;
(c) removing the solvent;
(d) drying the solids to a free flowing powder.

1 more element

A process for preparing a supported metallocene alumoxane catalyst for gas polymerization of ethylene and alpha olefin monomers, comprising the steps of:

(a) adding undehydrated silica gel to a stirred solution of a aluminum trialkyl in an amount sufficient to provide a mole ratio of aluminum trialkyl to water of from about 3:1 to about 1:2 and allowing the mixture to react;
(b) adding to the reaction mixture a metallocene of the formula:
(Cp).sub.m MR.sub.n X.sub.q wherein Cp is a cyclopentadienyl ring, M is a Group 4b or 5b transition metal, R is a hydrocarbyl group of hydrocarboxy group having from 1 to 20 carbon atoms, X is a halogen, and m is a whole number from 1 to 3. n is a whole number from 0 to 3, and q is a whole number from 0 to 3;
(C.sub.5 R'.sub.k).sub.g R".sub.s (C.sub.5 R'.sub.k)MQ.sub.3-g' or
R".sub.s(C.sub.5 R'.sub.k).sub.2 MQ' wherein (C.sub.5 R'.sub.k) is a cyclopentadienyl or substituted cyclopentadienyl, each R' is the same or different and is hydrogen or a hydrocarbyl radical containing from 1 to 20 carbon atoms, a silicon-containing hydrocarbyl radical, or a hydrocarbyl radical wherein two carbon atoms are Joined together to form a C.sub.4 -C.sub.6 ring, R" is C.sub.1 -C.sub.4 alkyene radical, a dialkyl germanium or silicone, or an alkyl phosphine or amine radical bridging two (C.sub.5 R'.sub.k) rings, Q is a hydrocarbyl radical having 1-20 carbon atoms, hydrocarboxy radical having 1-20 carbon atoms or halogen and can be the same or different, Q' is an alkylidene radical having from 1 to about 20 carbon atoms, s is 0 to 1, g is 0, 1 or 2;
when g is 0, s is 0;
k is 4 when s is 1 and k is 5 when s is 0 and M is as defined above;
(c) removing the solvent;
(d) drying the solids to a free flowing powder.

6 more elements

Dependencies are inferred from the claim text.

Method for preparing a supported metallocene-alumoxane catalyst for gas phase polymerization

Life of this patent

Method for preparing a supported metallocene-alumoxane catalyst for gas phase polymerization

Life of this patent

Abstract

Claims20