Polymerization process using a silica gel supported metallocene-alumoxane catalyst
AssigneeExxon Chemical Patents Inc.
InventorMain Chang
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Abstract
This invention relates to a process for polymerizing olefin using a supported metallocene alumoxane catalyst, which can be used in slurry or liquid phase polymerization of olefins. The invention relates to the use of silica gel containing from about 10 to about 50% 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 was formed to which a metallocene may be added. The resulting material can either be used in this slurry state for slurry polymerization or can be used for liquid phase polymerization.
Claims10
A process for polymerizing .alpha.-olefins either alone or in combination with one or more olefins, said process comprising contacting said .alpha.-olefins either alone or in combination with one or more other olefins in the presence of a supported metallocene alumoxane catalyst obtained by:
- (a) adding a water-impregnated catalyst support 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 10:1 to about 1:1 and allowing the mixture to react;
- and
- (b) adding a metallocene of a transistion metal of the Periodic Table of Elements to the reacted mixture in an amount sufficient to provide on said catalyst support a mole ratio of aluminum to transition metal of from about 1000:1 to about 1:1.
Dependencies are inferred from the claim text.