Azo dyes from 2-hydrazinothiazole, their use in dyeing and printing fibre materials, and in sublimation transfer printing

摘要

Azo dyes of the formula (I) IMAGE where R1 = Cl, CN or CO2X; R2 = CN or CO2X; and R3-R6 are customary azo dye substituents, are highly suitable for dyeing polyester fibres on account of good all round fastness properties, in particular good lightfastness. The novel dyes are obtained by oxidative coupling of appropriate 2-hydrazinothiazoles, some of which are likewise novel.