GB981825A - Improvements relating to the dyeing of polyamide fibres and to impregnation liquors therefor - Google Patents

Abstract

Synthetic or natural polyamide fibres are dyed by impregnating them with an optionally thickened aqueous solution of acid wool dyestuffs which contains as carrier a soluble salt of saturated aliphatic monocarboxylic acids having 8-14 carbon atoms and a p polyglycol ether of fatty alcohols or fatty acids having 8-14 carbon atoms, which polyglycol ethers contain 4-12 ether groups, the impregnation being carried out at temperatures below the drawing temperature of the dye-stuffs, and the dyeing finished by steaming and rinsing, or by an acid shock process. The dyes used are those which dye from a neutral or weakly acid bath, and may be metal free or metal containing or mordant dyes. The salts of saturated aliphatic monocarboxylic acids used are lithium, sodium, potassium, ammonium, N-alkyl, N-hydroxyalkyl or alkoxyalkyl substituted ammonium salts of caprylic, capric, pelargonic, lauric and myristic acids and especially those acids included in coconut oil fatty acids. Many of these salts are specified. The polyglycol ethers employed are those obtained by condensing 4-12, preferably 5-10 equivalents of ethylene oxide with one equivalent of octyl-, decyl-, dodecyl-, tetradecylalcohol or with one of the fatty acids referred to above. The acids used for the acid shock process include sulphuric, phosphoric, hydrochloric, formic and acetic acids. Conventional auxiliaries may be added to the dyeing or fixing baths, chromic acid and amides of the aliphatic carboxylic acids being especially used in the impregnation liquors. Continuous processes for dyeing wool, nylon and silk are referred to.