Stereospecific metallocene catalysts with stereolocking .alpha.-CP substituents
US5631202A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 24, 1993 |
| Grant date | May 20, 1997 |
| Priority date | — |
| Expiry date | Sep 24, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/943
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Isospecific and/or syndiospecific catalysts and processes for the propagation of an isotactic and/or syndiotactic polymer chain derived from an ethylenically unsaturated monomer which contains 3 or more carbon atoms or is a substituted vinyl compound. The catalysts comprise a stereorigid, stereodirected and stereolocked metallocene and/or metallocene cation catalysts, characterized by having .beta. stereodirecting substituents and .alpha. stereolocking substituents such that the catalysts have overall either C.sub.s or C.sub.2 (or pseudo-C.sub.s or C.sub.2) symmetry and such that the substituents define the orientation of the growing polymer chain end and resulting in tactioselectivity of successive monomer additions. Methods are also described for the preparation and use of these unique catalysts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.