Hafnium metallocene catalyst for the polymerization of olefins
US4794096A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 11, 1987 |
| Grant date | Dec 27, 1988 |
| Priority date | — |
| Expiry date | Sep 11, 2007 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/943
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention provides a catalyst system for the polymerization and copolymerization of olefins with the system comprising a chiral, stereorigid hafnium metallocene catalyst in combination with an aluminum compound. The aluminum compound is preferably an alumoxane and may be a mixture of alumoxane and trimethyl aluminum. It was discovered that this mixture causes a transformation of the catalyst over time. The catalyst system may also include a solvent to increase the solubility of the metallocene catalyst. It was discovered that these catalyst systems produce useful polymer products with molecular weights greater than 10,000.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.