Synthetic polyamide fibres colored with acid azobenzene dyestuffs, containing a N-alkyl (or substituted alkyl)-n-sulphophenoxyalkylamino radical in the para position to the azo linkage

Abstract

Polyamide fibres are colored with dyestuffs of the formula: ##STR1## wherein A represents the residue of a carbocyclic diazotisable amine, R represents an alkyl group, U represents a linear or branched alkylene group of 1 to 5 carbon atoms, V represents an arylene group, and A, B, R and V are unsubstituted or substituted with non-water-solubilizing substituents, and a process for their preparation which comprises diazotising an amine of the formula: A -- NH.sub.2 and coupling the diazo derivative thus obtained with a coupling component of the formula: ##STR2## wherein A, B, R, U and V have the same significance as above. The polyamide fibres exhibit excellent tinctorial yield, very remarkable brilliance, good fastness to washing and to light and good covering of bars.

Dependencies are inferred from the claim text.