Olefin polymerization method
US4460756A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 1983 |
| Grant date | Jul 17, 1984 |
| Priority date | — |
| Expiry date | Mar 28, 2003 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F10/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A supported chromium oxide polymerization catalyst is prepared by a process which includes the steps of heating silica-supported chromium oxide or a substance oxidizable to chromium oxide in a nonoxidizing atmosphere in the presence of formaldehyde or a compound thermally decomposable to formaldehyde, and then heating the thus-treated catalyst in an oxygen-containing atmosphere. The temperatures of the respective heating steps can vary depending upon the properties desired in the polymer to be produced with the invention catalyst; however, the invention catalyst preparation method enables the production of a catalyst having a high melt index potential at relatively low treatment temperatures, e.g. no higher than about 600.degree. C.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.