Process for removing impurities from polymers
US6160086A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 30, 1998 |
| Grant date | Dec 12, 2000 |
| Priority date | — |
| Expiry date | Jul 30, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F6/003
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A continuous, preferably counter-current, extraction process that can be used to significantly reduce the concentrations of residual monomers, residual catalyst, undesired solvents, and other impurities in polymer compositions. The invention is particularly beneficial for extracting residual monomers and other impurities from viscous, sticky polymer solutions, such as solutions of PSAs and low cohesive strength polymer compositions that phase change during extraction (i.e., change from liquid to solid, or precipitate), in a continuous manner. The polymer composition can be extruded into an extraction solvent as fibers in a vertical extraction column, under conditions such that at least a portion of an impurity is extracted from the polymer into the extraction solvent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.