Synthesis and application of a temporarily solubilised alkali-clearable azo disperse dye and analysis of its conversion and hydrolysis behaviour

A temporarily solubilised alkali-clearable azo disperse dye containing both a beta-sulphatoethylsulphone group and carboxylic acid ester groups was synthesised and applied to polyester for the purpose of the dispersant-free dyeing and alkali-clearability. The disperse dye containing only a beta-sulphatoethylsulphone group or that containing only carboxylic acid ester groups were also synthesised and their dispersant-free dyeing properties and alkali-clearability was compared with the temporarily solubilized alkali-clearable dye prepared. In order to investigate the feasibility of dispersant-free polyester dyeing and alkali-clearability, conversion behaviour, alkali-hydrolysis behaviour and colour fastness were assessed. The results showed that the temporarily solubilised alkali-clearable disperse dye could be successfully applied to polyester without the use of dispersants and has reasonable alkali-clearability; the dye exhibited good levelling and fastness properties on polyester. (C) 2002 Elsevier Science Ltd. All rights reserved.