Process for the removal of alkali metal halides from cellulose ethers soluble in cold water and use of the purified products in washing and cleansing agent compositions
Abstract
Abstract A process for the purification of cold-water soluble cellulose ethers containing alkali metal halides consisting essentially of suspending a cold-water-soluble cellulose ether crude reaction product containing 25% by weight or more of alkali metal halides, based on the dry weight, in an aqueous solution containing from 4% to about 25% by weight of one or more water-soluble salts of acids selected from the group consisting of polybasic inorganic acids and organic polycarboxylic acids with agitation at a temperature of from 10° C. to 50° C., separating the purified cellulose ether solids and optionally repeating the suspending and separating steps one or more times. The resulting material can be employed in washing and cleansing composition slurries for spray-drying. The process is especially suitable for the treatment of methyl cellulose or water-soluble mixed ethers of methyl or ethyl cellulose with a sodium sulfate solution.
Inventors
- 👤 Horst Ziche
Bibliographic Details
Claims Analysis
Total Claims: 6References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-10-19 | 1985-04-20 | 1985-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-10-19 | 1989-04-20 | 1989-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-10-19 | 1993-04-20 | 1993-10-20 | $7700.00 | Window Closed / Lapsed |