Polymerization of polyethylene
US6245867A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 29, 2000 |
| Grant date | Jun 12, 2001 |
| Priority date | — |
| Expiry date | Mar 29, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L2314/06
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A process for producing polyethylene in a two step polymerisation process that comprises the steps of: PA1 (a) homopolymerising ethylene in the presence of a first catalyst comprising an activated chromium catalyst in a first reactor to produce a first polyethylene fraction; PA1 (b) transferring the first polyethylene fraction produced in the first reactor and at least a portion of the first catalyst to a second reactor; PA1 (c) in the second reactor homopolymerising ethylene or copolymerising ethylene and an alpha-olefinic comonomer having from 3 to 10 carbon atoms in the presence of a second catalyst under conditions which suppress residual activity in the first catalyst to produce a second polyethylene fraction; and PA1 (d) retrieving from the second reactor polyethylene comprising a blend of the first and second polyethylene fractions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.