Patent GB-561117-A (GB)
Title: Manufacture of metallisable or metallised direct dyestuffs
IPC: C09B56/04
Filed: 1942-11-05
Abstract: Direct cotton dyes, convertible into metal complex compounds, are obtained by condensing, in presence of caustic alkali, an aminoazo dyestuff of the general formula:- <FORM:0561117/IV/1> wherein the naphthalene nucleus may be further substituted.  The condensation may be effected under pressure.  The products may be treated with an oxidising agent and/or may be treated in substance or on the fibre with an agent yielding metal, e.g. copper. Alternatively, the copper compounds may be produced in substance by starting with the copper compound of the aminoazo dyestuff. The amino group of the aminoazo dyestuff may be acylated by a group capable of being split off by the alkali.  In examples: (1) the aminoazo dyestuff, 2-aminophenol-4-sulphonic acid or its 6-chloro derivative --> 2 : 5-dimethoxyaniline and the triazole obtainable by oxidation of the azo dyestuff, 4 - nitro - 41 - aminostilbene - 2 : 21 - disulphonic acid --> 2 : 6-naphthylaminesulphonic acid, are condensed by boiling under reflux for 12-15 hours in aqueous solution containing caustic soda; the product may be converted, by heating for 10-12 hours at 80-90 DEG  C. in aqueous solution containing copper sulphate and ammonia, into its copper compound which dyes cellulose fibres olive shades, fast to light; the copper compound may be oxidised with alkaline sodium hypochlorite to obtain a product dyeing pure olive shades; (2) the copper compound of the aminoazo dyestuff, 2 - aminophenol - 4 - sulphonic acid-->m-anisidine, and the triazole of (1) or the corresponding triazole derived from 2-naphthylamine in place of its 6-sulphonic acid are similarly condensed; the products dye cellulose fibres reddish brown shades, fast to light; if the parent aminoazo dyestuff is used as the starting material and the product is subsequently coppered, more bluish brown shades are obtained; (3) the aminoazo dyestuff, 4 - chloro - 2 - aminophenol --> m - anisidine, and the triazole of (1) or the triazole obtainable by oxidation of the azo dyestuff, 4-nitro-41-aminostilbene-2 : 21-disulphonic acid --> 2 : 5 : 7-naphthylaminedisulphonic acid, are condensed similarly or by heating the alkaline solution for 8-10 hours at 110-120 DEG  C. under pressure, and the product is converted into its copper compound, which dyes cotton deep brown shades, fast to light; (4) the aminoazo dyestuff, 4 - nitro - 2 - aminophenol --> m - wherein X represents OH or COOH or, if the nucleus A carries, in addition, a solubilising group, X may represent O-alkyl or halogen, Y represents OH or O-alkylene-COOH or, if the nucleus A carries OH and COOH groups, Y may represent O-alkyl, Z represents H, SO3H or COOH, and the nuclei A and B may be further substituted, with a triazole of the general formula:- <FORM:0561117/IV/2> anisidine, and the triazole of (1) are condensed by boiling under reflux for 14-16 hours in aqueous solution containing caustic soda; the product dyes cellulose fibres, with after-coppering of the dyeings, brown-red shades, fast to light and to water; (5) the aminoazo dyestuff, 2-aminophenol-4-sulphonic acid --> 2 : 5-dimethoxyaniline, and the triazole obtainable by oxidation of the azo dyestuff, 4-nitro-41-aminostilbene - 2 : 21 - disulphonic acid --> 2 : 3-aminonaphthoic acid, are similarly condensed and the product is converted into its copper compound, which dyes cellulose fibres olive shades, fast to light.  A table is also given showing the shades obtainable on cellulose fibres with the copper complex compounds of the dyestuffs from various combinations of aminoazo and triazole components, additional diazo components for the aminoazo dyestuff being anthranilic acid, 5-nitro-2-aminobenzoic acid, 2 - chloroaniline - 5 - sulphonic acid and 2 - aminophenol - 4 - sulphonamide, additional coupling components therefor being 2-amino-4-hydroxytoluene and 3 - aminophenoxyacetic acid.  Other diazo components referred to in the Specification are 4-chloro-2-aminophenol-5-and 6-sulphonic acids, 3-amino-4-methoxybenzoic acid and 5-nitro-2-aminophenol and other coupling components are m-aminophenol and 2-amino-4-methoxytoluene.