Exhaust dyeing

摘要

A process of dyeing natural or synthetic polyamide fibres in an aqueous exhaustion dyebath comprising an anionic dyestuff, comprising the steps of 1. immersing the fibres to be dyed in the aqueous dyebath which has a temperature of from 20 DEG -50 DEG C. and a pH of 7-11 (7-8.5 when the polyamide is wool); and 2. raising the temperature to 110 DEG C. maximum and maintaining it there until exhaustion is substantially complete; there being added to the dyebath, either prior to the commencement of temperature raising or after an alkaline migration period at the boil, an ester of a C2-C3 hydroxycarboxylic acid with a C2-C6 glycol and up to 30% by weight of the ester of a tertiary amine which is essentially non-volatile under the process conditions.