Photoreactive Dyes: The Potential of Azido‐substituted Dyes as Latent Reactive Dyes for Wool

Abstract

Dyes containing azido substituents have been examined as latent reactive dyes for wool and nylon. Three different substituents, viz. azidophenyl, azidosulphonyl and diazidotriazinyl, were used. It was found that dyes containing azidophenyl groups could be applied under conditions where little reaction with the fibre occurred. These dyes could then be induced to react covalently with the fibre either by irradiation with light or by ironing at 200d̀C. However, the binding of the dye to the fibre occurs in rather low yield (30–40%) and, in some cases, is accompanied by a marked colour change. Dyes containing azidosulphonyl or diazidotriazinyl substituents react with wool and nylon during application, and they are therefore unsuitable as latent reactive dyes.