GB190423193A - Manufacture of Blue and Violet to Black Dyestuffs by Oxidation on the Fibre. - Google Patents

Abstract

23,193. Imray, O., [Farbwerke vorm. Meister, Lucius, & Br³ning]. Oct.. 27. Dyeing.-Fabrics of vegetable or animal fibres, such as cotton, silk, wool, and mixed fabrics, are dyed blue and violet to black shades, fast to soap, soda, acid, and light, by oxidizing p-amidodiphenylamine or its derivatives, on the fibre, together with hydroxy- and amino-aryl compounds and their ethers, such as phenols, naphthols, or their ethers, oxycarboxylic acids or their esters, o-amidophenol ethers, primary, secondary, and tertiary m-amidophenols, alkylated and alphylated m-phenylenediamines or naphthylamines, or the like, a large number of examples being given. For the p-amidodiphenylamine may be substituted p-amidomethyldiphenylamine, p-amidophenyltolylamine, p-amidop-oxy-diphenylamine, and p-diamido- and symmetrical dimethyl-p-diamido-diphenylamines and other analogous or homologous derivatives. To prepare the dyes, the two components to be oxidized are dissolved together or separately and stirred with a thickener, such as acid starch or tragacanth, for printing or padding respectively, and the oxidizing- agents added, the chlorates in the presence or absence of oxygen carriers being specially suitable. Acid salts, such as aluminium chloride, which do not attack the fibre, may be used to start the oxidation, free mineral acids being unnecessary. After the material to be dyed has been printed or padded with the mixture, it is dried and the colour developed, and simultaneously fixed, by prolonged aÙration in a warm place or by steaming, after which it is washed and soaped. The components may be successively applied and then oxidized jointly. Most dyes so produced are fast without a mordant. Those with strong basic groups, such as a dialkylamine group, may be fixed with tannin, and those with an o-carboxyl or o-hydroxyl group may be fixed with a chromium mordant. For example, a colour for printing blue-black contains p-amidodiphenylamine, m-oxydiphenylamine, acetic and lactic acids, acid starch thickening, aluminium and cerous chlorides, alcohol, and water. A greenish-blue is obtained when the second component is m-oxydiethylaniline, tannin being added, and ceric chloride and glycerine replacing the cerous chloride and alcohol, respectively. Tannin colours may be passed through an antimony bath. A chromium-blue is given by a mixture containing ceric chloride and chromium acetate with methyl gallate as the second component. p-Amidodiphenylamine also gives with : #-naphthol, blue ; diethyl-m-amidophenol, greenish-blue ; resorcin, indigo-blue ; m-oxydiphenylamine, copper chloride replacing the cerium salt, blue-black ; o-anisidine, o-phenetidine, or m-amido-p-tolylphenylamine, violet; thioaniline, black. p-Amido-p-oxydiphenylamine with m-amido-p-tolylphenylamine gives violet. Resists may be obtained by printing with reducing-agents, such as potassium sulphite, hydrosulphite, or tin salts, and may be tinted as usual with reduction-resisting dyes. The process may be combined with that for producing an oxidation or steam black on the fibre which does not turn green, the black being thus shaded.