Supported metallocene catalyst system and method for polymerizing olefins
US6239060A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 31, 1998 |
| Grant date | May 29, 2001 |
| Priority date | — |
| Expiry date | Dec 31, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/943
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The present invention provides a new type of supported metallocene catalyst system. In one aspect of the invention, an inorganic oxide support, such as silica, is impregnated with a Group XIII element such as B, Al or GA. The support is then contacted with a liquid catalyst system prepared by combining in a liquid an organo aluminoxane and a metallocene having two cyclopetadienyl-type ligands selected from substituted or unsubstituted cyclopentadienyl, indenyl, benzoindenyl, tetrahdroindenyl, benzofluorenyl, octahydrofluorenyl, and fluorenyl ligands to form a supported metallocene catalyst system. In preferred embodiments the process further includes conducting prepolymerization of at least one olefin in the presence of the supported metallocene catalyst system to produce a prepolymerized metallocene catalyst system. The prepolymerized metallocene catalyst system prepared in this manner yields substantially increased activity for the polymerization of olefins. In another aspect, the present invention also provides a method for polymerization of olefins using the inventive supported metallocene catalyst system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.