Dyeing of polyamide fibers with anionic dyes using a cationic assistant followed by an anionic assistant

摘要

The invention relates to a process for dyeing synthetic or natural polyamide fibers with anionic dyestuffs, comprising (i) bringing the polyamide fibers into contact with an aqueous dyeing liquor which contains in addition to one or more dyestuffs a cationic dyeing assistant having affinity for anionic polyamide dyestuffs, and dyeing the polyamide fibers at a temperature of from 60° to 105° C., and (ii) adding an anionic dyeing assistant to the dyeing liquor 15 to 60 minutes after reaching the dyeing temperature, to complete the dye exhaustion. Surface and fibre level dyeings with a good dye penetration are thus obtained.