Ciba-Geigy Corporation

Ciba Specialty Chemicals Corporation

Hanspeter Birri

Alex Nicopoulos

Gerhard Hanika

The compounds of formula ##STR1## wherein the substituents are as defined in the claims, are suitable for dyeing or printing, inter alia, polyacrylonitrile and acid-modified polyester fibers, and can furthermore be converted by anion exchange into a physical form suitable for liquid formulations.

Oxazine dyes, their preparation and the use thereof

There is described a process for the preparation of highly concentrated aqueous solutions of specific cationic azo dyes. The solutions are prepared by diazotising a diazo component in a solution which contains sulfuric acid, coupling the diazotised component to a coupling component, treating the resultant azo dye with a bicarbonate, and converting the dye bicarbonate with an organic acid into the dye salt of said acid.

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Pratteln, Switzerland

Hanspeter Birri