GB1120784A - Heterogeneous cobalt complex dyes, their production and use - Google Patents

Abstract

A process for the production of heterogeneous cobalt metal complex dyes comprises treating a mixture of azo compounds containing groups capable of metal complex formation in substance or on the fibre with a cobalt yielding agent in which at least one of the azo compounds is of the formula <FORM:1120784/C4-C5/1> in which W is chlorine, bromine or low molecular alkyl or alkoxy group and the -SO3H group is in the 31, 41 or 51 position and at least one other azo compound preferably 2 others are of formula <FORM:1120784/C4-C5/2> in which each of the radicals R is hydrogen, nitro, chlorine, bromine, low (C1-C4) molecular alkyl or alkoxy group, Y is hydroxy, amino, or -NHX in which X is an unsubstituted or substituted aryl radical and Z is hydrogen, -CONH2 or -CONH-X, the complex being such that less than two cobalt atoms are bound with two azo compound molecules. The complexes are violet-blue in colour and are used in wool, silk, leather and polyamide fibres, secondary cellulose acetate and in lacquer solutions.ALSO:In dyeing Example C, a lacquer solution is prepared from 20 parts of vinyl chloride-vinyl acetate copolymer, 70 parts of methyl-ethyl ketone, 10 parts of ethylene glycol and 1/2 part of a cobalt containing dye obtained in Example 1, the lacquer then being diluted with methyl-ethyl-ketone/cyclohexanone mixture and cast onto aluminium foil and dried a violet-blue shade being obtained.ALSO:Cobalt complex azo dyes are used to dye polyamides e.g. wool, silk, leather, nylon in violet-blue shades. The dyes may be formed in situ on the fibre. In Example A wool and nylon are dyed at the boil with a dye produced in Example 1; a violet blue shade being obtained.