A range of monoazo blue disperse dyes has been synthesised by coupling benzenoid and heterocyclic diazo components to aniline derivatives containing ester functions. The colour properties and wet fastness of the dyes on polyester at 1/1 standard depth have been examined and rationalised in terms of dye structure. Styryl dyes have also been prepared in order to compare their wet fastness properties to those of the azo dyes.

Blue monoazo disperse dyes bearing carboxylic acid ester functions have been synthesised from thiophene diazo components in the search for colorants of high fastness and reduced environmental impact. The colour properties of the dyes in solution and on polyester, as well as the fastness of the dyes when applied to polyester, are examined and rationalised in terms of dye structure.