Bunte salt azo dye compound
AssigneeClariant Finance (BVI) Limited
InventorsJames Myron Hanna, Jr., Guido Joseph Danhieux
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Abstract
The invention relates to a Bunte salt azo dye composition comprising an azo dye containing at least one Bunte salt group. The resulting dye is water soluble material which is useful in the rapid dying of natural and synthetic fibers. The Bunte salt azo dye of the present invention can be used without requiring a mordanting step or a concurrent or pre-reducing step to condition fibers of animal hair to accept the dye to achieve strong color performance.
Claims18
A dye compound of the formula (1)
- wherein R1 and R2 are either hydrogen or a phenylamino radical, and R1 and R2 are different.
A process for producing a Bunte salt azo dye comprising:
- a) diazotizing S-(4-aminophenyl) thiosulfate a to provide a diazonium salt;
- b) coupling the diazonium salt under alkaline conditions to a salt of an aryl-amino-hydroxy-naphthalene sulfonic acid to provide the Bunte salt azo dye.
A process for producing a red Bunte salt azo dye comprising:
- a) diazotizing S-(4-aminophenyl) thiosulfate to provide a diazonium salt;
- b) coupling the diazonium salt under alkaline conditions with 2-phenylamino-5-naphthol-7-sulfonic acid, or 6-phenylamino-1-naphthol-3-sulfonic acid to provide the red Bunte salt azo dye.
A process for producing a brown Bunte salt azo dye comprising:
- a) diazotizing S-(4-aminophenyl) thiosulfate to provide a diazonium salt;
- b) coupling the diazonium salt under alkaline conditions to 2-phenylamino-naphthalene-8-hydroxy-6-sulfonic acid to provide the brown Bunte salt azo dye.
Dependencies are inferred from the claim text.