Process and apparatus for intermittent polymerization at elevated pressure
US4296221A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 28, 1980 |
| Grant date | Oct 20, 1981 |
| Priority date | — |
| Expiry date | Mar 28, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/918
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The gas to be polymerized is introduced into the working zone of a high pressure piston compressor and is compressed in timed relation to a pressure suitable for the polymerization. The gas temperature suitable for the polymerization process at the end of the compression stroke is set by cooling or heating the gas before the gas enters the compressor. The catalyst or initiator activating the polymerization is introduced into the working zone of the compressor during the compression stroke or after completion thereof, e.g. with the aid of a controlled injection valve. The gas containing the polymer and expanded approximately to the initial pressure is passed out of the compressor into a separator and is here freed from the polymer, while the residual gas is re-cycled to the compressor by means of a blower. For the polymerization of high-pressure polyethylene, the gas is compressed to a final pressure of about 2500 kg/cm.sup.2 at a temperature of about 130.degree. C. in the working zone of the compressor before introduction of the catalyst. The compressor may operate in a two-stroke or four-stroke cycle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.