Azo dispersion dyes for synthetic fibres - from aromatic dicyan-amines as diazo components, and coupling components contg carboxylic gps

摘要

Azo dyes free of SO3H gps., of formula: (in which X1 and X2 are alkyl, cycloalkyl, aralkyl or aryl, or form part of a non-aromatic carboxyclic ring; X3 is H, alkyl, aralkyl or aryl; K is the gp. of a coupling component; n is 1 or 2) are useful as dispersion dyes for synthetic fibres of cellulose acetates, polyurethanes, and esp. polyamides and aromatic polyesters from aq. dispersions or organic solns. Esp. for dyeing polyesters in aq. alkaline solns. of the dye, which are then acidified to release the free acid. Give clear yellow to red shades with good general fastness.