Polymerization catalysts and methods
US4206297A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 7, 1978 |
| Grant date | Jun 3, 1980 |
| Priority date | — |
| Expiry date | Jul 7, 1998 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/905
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A polymerization catalyst and method which produces substantially pure silica that is uncontaminated with alkali metal or alkaline earth metal ions before associating with the resulting support silica the chromium compound which is either a chromium oxide or a chromium compound convertible to the oxide in the heat activating of the catalyst. In general, the catalyst is prepared by hydrolyzing an organosilicate ester to form suspended silica with the hydrolyzing being catalyzed with an aqueous acid solution containing mixed solvents. Next the resulting liquid is neutralized with an alkali free basic solution such as ammonium hydroxide at controlled low temperature. Then sufficient water is added to permit stirring the resulting gel and this is stirred and heated forming a suspended silica. The silica is then separated and dried, associated with the chromium compound and the mixture then heat activated in the presence of oxygen.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.