Preparation of metallocene catalysts for polymerization of olefins
US5387568A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 1992 |
| Grant date | Feb 7, 1995 |
| Priority date | — |
| Expiry date | Apr 13, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/943
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
This invention uses a new method of producing ionic metallocene compounds. These compounds are useful as catalysts for polymerization of olefins, primarily propylene. This method uses an ionizing agent which ionizes the neutral metallocene compound. The ionizing ionic compound does not contain an active proton and contains a carbonium, oxonium or sulfonium cation. The anion of the ionizing ionic compound is not coordinated or is only loosely coordinated to the metallocene cation and is chemically unreactive with the metallocene cation. Examples of such compounds are triphenylcarbenium tetrakis(pentafluorophenyl)boronate, triphenylcarbenium tris(pentafluorophenyl)phenyl boronate and triphenylcarbeniumtris(pentafluorophenyl)4-trimethylsilyl-2,3,5,6-tetraflu orophenylboronate. The process of making catalysts with this invention produces catalysts having high activity and does not produce by-products which can inhibit catalyst activity. This new synthesis is a clean reaction which does not produce a Lewis base. The process generates active catalysts by removing a methyl anion from a group IVB metallocene derivative.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.