Process for the gas-phase polymerization of olefins
US5733987A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 1993 |
| Grant date | Mar 31, 1998 |
| Priority date | — |
| Expiry date | Mar 12, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/901
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Process for the gas-phase polymerization of ethylene and ethylene mixtures with .alpha.-olefins CH.sub.2 .dbd.CHR in the presence of a high activity catalyst comprising a titanium compound containing at least one Ti-halogen bond, supported on magnesium dichloride in active form said process comprising the steps of: (a) contacting the catalyst component; (b) prepolymerizing ethylene or ethylene mixtures with .alpha.-olefins in order to produce a polymer amount of from approximately 5 g per g of solid component, up to an amount corresponding to about 10% of the final catalyst yield; (c) polymerizing ethylene or ethylene mixtures with .alpha.-olefins in the gas-phase, in the presence of the prepolymer-catalyst system obtained in (b), while maintaining in the gas phase a molar concentration concentration of the alkane comprised between 20 and 90% with respect to the total gases.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.