GB654491A - Manufacture of new disazo-dyestuffs and new cupriferous disazo-dyestuffs - Google Patents

Abstract

Diazo dyestuffs are manufactured by coupling a tetrazotized 4 : 41-diamino-3 : 31-dialkoxydiphenyl (in which the alkoxy groups preferably contain only a few carbon atoms) with a 1-naphtholtrisulphonic acid (e.g. the 4 : 6 : 8-or especially the 3 : 5 : 7- or 3 : 6 : 8-trisulphonic acid) and with a coupling component free from sulphonic acid groups and capable of coupling in a position vicinal to a hydroxy group (e.g. naphthols or substitution products thereof such as those containing halogen atoms, alkyl groups, alkoxy, including hydroxyethoxy, groups, -CO-alkyl or -CO-aryl residues, free or substituted amino groups, or sulphonamide groups with or without substituents at the nitrogen atom; 2 : 3-hydroxynaphthoic amides, especially arylides; 3-hydroxydiphenylene oxide, 2- or 3-hydroxycarbazole, or 2 : 4- or 4 : 6-dihydroxyquinoline or their N-substitution derivatives; acetoacetic arylides; pyrazolones; or arylides of 3-hydroxycarbazole-2-carboxylic acid, 3-hydroxydiphenylene oxide-2-carboxylic acid or 2-hydroxyanthracene-3-carboxylic acid). The couplings are preferably effected in the order stated, with the first in a weakly alkaline (e.g. alkali bicarbonate or carbonate) medium and the second in a more strongly alkaline medium (e.g. a medium alkaline to phenolphthalein or containing free alkali hydroxide), if desired at a somewhat raised temperature and/or with the addition of an agent accelerating coupling (e.g. pyridine). The products may be converted into complex copper compounds by treating them (with or without isolation from the coupling mixture) with an agent yielding copper (e.g. a cuprous or cupric salt or especially a cuprammine complex) until the alkoxy groups have been split up (e.g. for several hours at 80-90 DEG C.), advantageously with the addition of ammonia or organic bases (e.g. excess of the base present in the cuprammine complex if used) or other acid-binding agents. The metal-free and the cupriferous dyestuffs are suitable for dyeing or printing animal fibres (e.g. silk, wool or leather), and especially cellulosic fibres (e.g. linen, cotton or regenerated cellulose), yielding mainly blue tints. Those which are capable of combining with a further quantity of metal may be metallized on animal fibres. Examples describe the preparation of dyestuffs from diamisidine and certain of the coupling components specified above, and the dyeing of cotton with the copper complex of the dyestuff 1 - naphthol - 3 : 6 : 8 - trisulphonic acid \sMdiamisidine-->2 : 3 - hydroxynaphthoic anilide. Specification 644,883 is referred to.