Process for the start up of polymerization or copolymerization in the gas phase of alpha-olefins in the presence of a ziegler-natta catalyst system
US5077358A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 12, 1991 |
| Grant date | Dec 31, 1991 |
| Priority date | — |
| Expiry date | Apr 12, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/904
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention relates to a process for the start up of polymerization or copolymerization in the gas phase by bringing the said alpha-olefins in contact under polymerization or copolymerization conditions in a fluidized bed and/or with mechanical stirring with a charge powder, in the presence of a catalyst system of the Ziegler-Natta type, this process being characterized in that the charge powder used is previously dehydrated and subjected to a treatment by bringing the said charge powder into contact with an organoaluminum compound for a period of at least five minutes, so that the polymerization or copolymerization starts up immediately after the contracting of the alpha-olefins with the charge powder in the presence of the catalyst system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.