Ultrafiltration purification of solution of polymeric anthraquinone colorants
US4088572A · kind A · utility
7Cited by
2References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 18, 1976 |
| Grant date | May 9, 1978 |
| Priority date | — |
| Expiry date | Nov 18, 1996 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D63/02
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The ultrafiltration purification of aqueous solutions of polymeric anthraquinone colorants, wherein low molecular weight impurities are removed in an ultrafiltrate leaving a purified anthraquinone colorant-bearing retentate, is carried out with improved efficiency when pyridine is present and maintained in the aqueous solutions at a level of from 1 to 20% by volume.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.