Mixed catalyst system
US6069213A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 16, 1997 |
| Grant date | May 30, 2000 |
| Priority date | — |
| Expiry date | Dec 16, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/943
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
It has been found that the use of at least one unsupported metallocene polymerization catalyst with at least one supported metallocene polymerization catalyst in the polymerization of olefins allows for better control of the polymerization, especially gas phase polymerization. Such a system takes advantage of the high activity of the unsupported catalyst and the stability of a supported catalyst. Additionally, the relative timing of the addition of the supported and unsupported catalysts to a reaction system can be used to control a continuous polymerization reaction by stabilizing the reactor bed with the supported catalyst prior to addition of the unsupported catalyst.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.