Process for the preparation of dyes which contain sulfonic acid groups and have a low electrolyte content
CA 1160625 A · Owner: Basf Aktiengesellschaft · Inventors: Brunnmueller, Fritz; Weberndoerfer, Volkmar; Bermes, Rudolf
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The present invention relates to a process for the preparation of dyes having a sulfo group and a low electrolyte content comprising, (a) mixing at elevated temperature an aqueous solution or suspension of a dye having a sulfo group and a non-emulsifying waterinsoluble amine having 12 to 40 carbon atoms, such that approximately one equivalent of amino group of the amine is used per equivalent of sulfo group in the dye and such that the pH of the mixture is adjusted to <5 with an acid;, (b) isolating the water-insoluble amine salt of the sulfo group containing dye;, (c) adding a water-soluble base to said amine salt to form a water-soluble sulfonate salt; and, (d) separating the …
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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
- Granted January 17, 1984. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended January 17, 2001.
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Timeline
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Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.