Process of dyeing fibres

摘要

Organic fibres or filaments, e.g. of polyamides, acrylic polymers, polyesters, cellulose acetate (including triacetate), natural and regenerated cellulose, silk and especially keratinous materials including human and animal hair, furs, feathers and wool, are dyed by treatment in the absence of nitrous acid or any salt thereof with an aqueous solution containing metal ions of one or more of the metals Co, Ni, Cu, Zn, Pd, Ag and Cd and with a dithio-oxamide. The metals are preferably in the form of sulphates or chlorides. The specified dithio-oxamides are of the formula where R is hydrogen, alkyl, carboxyalkyl, aminoalkyl, sulphoalkyl, acetoalkyl, hydroxyalkyl, phenylalkyl, pyridylalkyl, phenylpyridyl, chlorophenyl, allyl, benzyl, furfuryl or pyridyl or are alkali metal or alkaline earth metal or ammonium salts of the carboxyalkyl and sulphoalkyl dithio-oxamides among which are, for example, dithio-oxamide, N,N1-dimethyl-dithio-oxamide, N,N1-bis(3-methoxypropyl) dithio-oxamide and N,N1-bis(2-sulphoethyl) dithio-oxamide dicalcium salt. The metal ions and the dithio-oxamide may be applied simultaneously or in either sequence; when applied from the same solution a complexing agent may be included, e.g. thiourea or alkali metal salts of hydroxyethyl-ethylene diaminetetraacetic acid. The concentration of both the metal salt and the dithio-oxamide solution may be from 0,00002 M up to a saturated solution, preferably 0,002 M, which solutions may also contain water-imiscible solvents, e.g. acetone and ethanol. In the preferred method of dyeing keratinous fibres the fibres are first soaked in a metal ion solution at 20 DEG -95 DEG C. at a pH of 4-10 and then soaked in a dithio-oxamide solution. Examples are given. Specification 521,648 is referred to.