The rate of hydrolysis of temporarily solubilised disperse dyes

Four temporarily solubilised disperse dyes were synthesised. To obtain the optimum application conditions for dispersant‐free polyester dyeing, their conversion rates into insoluble derivatives were measured using HPLC and found to be more dependent on pH than on temperature. The results showed that it was possible to use these dyes in dispersant‐free polyester dyeing for which the optimum application pH was between pH 5 and 6 at which the hydrolysis rate of the dyes was moderate.