Synthesis and application of temporarily solubilised azo disperse dyes containing β-sulphatoethylsulphonyl group

A series of temporarily solubilised azo disperse dyes containing β-sulphatoethylsulphonyl group in their structures were synthesised for dispersant-free dyeing of polyester. Diazo components having nitro or bromo group were prepared and coupled with corresponding coupling components to give 4-diethylamino-4′-(2-sulphatoethylsulphonyl)azobenzene dyes. The absorption maxima of the dyes were dependent upon the substituents in the diazo and coupling components and varied from 464 to 528 in DMF. Polyester fabric was successfully dyed with the synthesised dyes without using any dispersing agent. The dyes showed good build-up, leveling and fastness properties on polyester.