The synthesis and application of a new reactive dye based on disulfide-bis-ethylsulfone

A new reactive dye containing a bis-ethylsulfone-disulfide has been synthesised. This dye is able to eliminate to two small vinylsulfone dye molecules under alkaline conditions. When applied to cotton fabrics the bis-ethylsulfone-disulfide dye shows higher primary exhaustion than a corresponding model sulfatoethylsulfone dye and can be covalently bonded to the substrate by raising the pH to 11.5. Any hydrolysed dye produced is approximately half the size of the starting dye molecule and thus soaping-off properties are the same as the normal sulfatoethylsulfone dye.