Method and apparatus for reducing vat and sulfur dyes
CA 2318796 A1 · Owner: Marte, Walter · Inventors: Meyer, Ulrich; Marte, Walter; Dossenbach, Otmar
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
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.
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed November 24, 1999. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 24, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 24, 2021.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.