Process for the preparation of polyethylene which has a broad molecular weight distribution
US6063878A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 12, 1997 |
| Grant date | May 16, 2000 |
| Priority date | — |
| Expiry date | Sep 12, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F210/16
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Process for the preparation of polyethylene by the homopolymerization of ethylene or by the copolymerization of ethylene and of at least one alpha-olefinic comonomer containing from 3 to 10 carbon atoms, in two reactors for loop polymerization in liquid phase which are connected in series in the presence of a chromium catalyst, in which ethylene and the chromium catalyst are first introduced into the first reactor at a temperature of 95 to 110.degree. C. to produce an ethylene homopolymer of low molecular weight of a melt index MI.sub.2 of at least 1 g/10 minutes and in which the ethylene homopolymer thus obtained is next transferred into the second reactor to which ethylene and optionally the alpha-olefinic comonomer is added, at a temperature of 80 to 90.degree. C. to obtain an ethylene copolymer of high molecular weight.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.