Continuous removal of residual hydrocarbons from polyolefins
US4391972A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 1981 |
| Grant date | Jul 5, 1983 |
| Priority date | — |
| Expiry date | Apr 2, 2001 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F6/10
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Polyolefins which are made by subjecting .alpha.-olefins to catalytic polymerization are freed from residual liquid hydrocarbons by means of steam and water. To this end, the invention provides: PA1 (a) for the hydrocarbon-containing polyolefin to be introduced into an aqueous emulsifier-containing emulsion and for the resulting mixture to be stirred so as to be converted to a homogeneous dispersion; PA1 (b) for the dispersion to be introduced into the upper portion of a column with at least 5 sieve plates therein and contacted countercurrently with steam of about 100.degree. to 120.degree. C., the individual plates provided in the column having a free cross-sectional area which increases continuously from the lowermost to uppermost plate by about 3% up to 90% of the plate surface area, and being spaced apart from each other at approximately the same ratio from below to above; and PA1 (c) for the aqueous polyolefin dispersion free from hydrocarbons to be removed through the base portion of the column and for the polyolefin to be separated from the water.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.