Sandoz Gmbh

Fidelity Union Trust Company, Executive Trustee Under the Sandoz Trust

Roland Entschel

Willy Steinemann

Hermann Burkhard

Beat Henzi

Curt Mueller

Ulrich Blass

Compounds of the formula ##STR1## in which R.sub.1 signifies a substituted thiazole, thiadiazole, isothiazole, oxadiazole or thiophene radical,

Heterocyclyl-azo-phenyl dyes having a cationic group linked through a

Azo dyes of the formula ##STR1## wherein D is an aromatic carbocyclic or heterocyclic diazo component radical,

Cationic 5-arylazo-6-hydroxypyridone-2 dyes

Dyes of the formula ##STR1## wherein R.sub.1 is a carbocyclic or heterocyclic diazo component radical,

Azo dyes having a 6-hydroxy-pyridone-2 coupling component radical having

Compounds of the formula ##STR1## wherein EACH OF D.sub.1 and D.sub.2 is independently a diazo component radical, e.g., phenyl, naphthyl, thiazolyl, benzothiazolyl or benzoisothiazolyl, or a substituted derivative thereof,

Diazo compounds containing two optionally

Dyes of the formula ##STR1## wherein R.sub.1 is hydrogen or cyano,

1-Aminoalkylene-3-cyano-4-methyl-6-hydroxy-1,2-dihydropyrid-2-ones

Concentrated solutions of cationic azo dyes are prepared directly from sparingly soluble salts of the dye in a one-step reaction by reacting the sparingly soluble dye with a non-chromophoric carboxylate salt, the cation of which forms an insoluble or sparingly soluble salt with the anion of the starting cationic azo dye in the solvent system employed.

Growing community of inventors

Basel, Switzerland

Roland Entschel