Effect of Acylation on the Dyeing and Fastness Properties of Some Azo Dyes

The changes brought about by acetylation, benzoylation and terephthaloylation of some disperse dyes derived from 4-aminoazobenzene on the dyeing and fastness properties are described. Dyes substituted by benzoyl and terephthaloyl groups tended to have better light, wash and sublimation fastness on polyester. The dyes showed good build-up when these groups are coupled with an N-beta-cyanoethyl group. Acylation of azo dyes resulted in poor substantivity and poor fastness properties on nylon 6