Medium density ethylene polymers, a process to prepare these polymers and use of carbonyl group containing chain transfer agents in this process
US6407191B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 20, 2000 |
| Grant date | Jun 18, 2002 |
| Priority date | — |
| Expiry date | Nov 20, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F110/02
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The present invention relates to an ethylene homo or copolymer having a density of between 0.923 and 0.935 g/cm3, having a molecular weight distribution Mw/Mn of between 3 and 10, and comprising from 0.10 to 0.50 wt. percent of units derived from a carbonyl group containing compound, based on the total weight of the homo or copolymer. In addition, the invention relates to a free radical initiation polymerization process for the preparation of medium density ethylene polymers or copolymers, comprising reacting ethylene and optionally one or more comonomers at a high pressure, conveniently between 1600 and 4000 kg/cm2, and at temperatures of about 150-330° C. in a reactor system consisting of at least one autoclave reactor or of a combination of autoclave and tubular reactors, in the presence of free radical initiators and a carbonyl group containing compound. Finally, the invention relates to carbonyl group containing chain transfer agents to obtain improved polymer processing and performance properties in flat die extrusion processes and applications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.