Method and apparatus for reducing vat and sulfur dyes
US6627063B1 · kind B1 · utility
Inventors
Key dates
| Filing date | Aug 31, 2000 |
| Grant date | Sep 30, 2003 |
| Priority date | — |
| Expiry date | Aug 31, 2020 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD06P5/2016
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
The invention relates to a method for the electrochemical reduction of vat and sulfur dyes in aqueous solutions, in steady-state conditions of reaction and a cycle which is largely free of reducing agents. The invention also relates to apparatus for carrying out said method. The steady-state conditions of reaction are obtained by means of a start reaction. The substances used for this reaction and the products resulting therefrom are extracted from the cycle. To maintain the cycle only dyes, an alkali and possibly small quantities of additional substances, such as surface-active agents, need to be added. No other chemicals active in the oxidation-reduction process are used.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.