Salt addition in ultrafiltration purification of solutions of polymeric colorants
US4189380A · kind A · utility
7Cited by
9References
15Claims
0Family size
Assignee
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Key dates
| Filing date | Nov 18, 1976 |
| Grant date | Feb 19, 1980 |
| Priority date | — |
| Expiry date | Nov 18, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S534/03
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The ultrafiltration purification of aqueous solutions of polymeric colorants, wherein low molecular weight impurities are removed in an ultrafiltrate leaving a purified polymeric colorant-bearing retentate, is carried out with improved efficiency when, during at least two diavolumes of ultrafiltration, the salt content of the retentate is maintained above about 1% by weight.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.