Multi-stage process for the polymerization of olefins
US6262195A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 9, 1999 |
| Grant date | Jul 17, 2001 |
| Priority date | — |
| Expiry date | Mar 9, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/943
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A multi-stage process for preparing ethylene (co)polymers having broad molecular weight distributions is disclosed, said process comprising: PA1 (A) a first polymerization stage in which, in the presence of a Ti or V catalyst, a first ethylene polymer is prepared; PA1 (B) a treatment stage in which the catalyst used in the first stage is deactivated and in which a bridged bis-2-indenyl zirconocene is supported on the ethylene polymer produced in stage (A), optionally in the presence of a suitable cocatalyst; and PA1 (C) a second polymerization stage in which ethylene is polymerized in the presence of the product obtained from stage (B). Furthermore, polyethylene obtainable by the above process is disclosed, having intrinsic viscosity ranging from 0.5 to 6 dl/g, Mw/Mn>8 and cold xylene solubility<1.2% wt.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.