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US 9,346,896 B2Granted
Silica-coated alumina activator-supports for metallocene catalyst compositions
AssigneeChevron Phillips Chemical Company LP
InventorsMax P. McDaniel, Qing Yang, Randy S. Muninger, Elizabeth A. Benham, Kathy S. Clear
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Abstract
Silica-coated alumina activator-supports, and catalyst compositions containing these activator-supports, are disclosed. Methods also are provided for preparing silica-coated alumina activator-supports, for preparing catalyst compositions, and for using the catalyst compositions to polymerize olefins.
Claims18
A catalyst composition comprising:
- (a) at least one metallocene compound;
- and
- (b) at least one activator-support;
- wherein the at least one activator-support comprises at least one silica-coated alumina treated with at least one electron-withdrawing anion, wherein:
- the at least one silica-coated alumina has a weight ratio of alumina to silica in a range from about 1:1 to about 100:1,
- the at least one electron-withdrawing anion comprises fluoride, and
- a catalyst activity of the catalyst composition is greater than that of a catalyst system containing the at least one metallocene compound and a silica-alumina treated with the at least one electron-withdrawing anion, under the same polymerization conditions.
4 more elements
A catalyst composition comprising:
- (a) at least one metallocene compound;
- (b) at least one activator-support;
- and
- (c) at least one organoaluminum compound;
- wherein the at least one organoaluminum compound comprises trimethylaluminum, triethylaluminum, tri-n-propylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diisobutylaluminum hydride, diethylaluminum ethoxide, diethylaluminum chloride, or any combination thereof;
- wherein the at least one activator-support comprises at least one silica-coated alumina treated with at least one electron-withdrawing anion, wherein:
- the at least one silica-coated alumina has a weight ratio of alumina to silica in a range from about 1.5:1 to about 20:1,
- the at least one electron-withdrawing anion comprises fluoride,
- the at least one silica-coated alumina has a surface area in a range from about 250 to about 500 m2/g and a pore volume in a range from about 0.8 to about 1.7 mL/g, and
- a catalyst activity of the catalyst composition is greater than that of a catalyst system containing the at least one metallocene compound, the at least one organoaluminum compound, and a silica-alumina treated with the at least one electron-withdrawing anion, under the same polymerization conditions.
7 more elements
Dependencies are inferred from the claim text.