GB497350A - Manufacture of complex metal compounds of polyazo-dyestuffs - Google Patents

Abstract

Complex metal compounds of polyazo dyes are made by treating with an agent yielding metal and an alkaline reducing agent in one and the same operation an azo dye containing the grouping <FORM:0497350/IV/1> wherein X represents a group capable of assisting the formation of a metal complex, until there is formed the corresponding azoxy-or azo-compound. An organic hydroxy compound may also be present in the reaction. The dyes are especially suitable for dyeing cotton. In the examples, dyes from the following components, viz.: 5-nitro-2-amino-phenol, 4-chlor-5 - nitro-2 - aminophenol; 2-amino - 5 - naphthol - 1 : 7 disulphonic acid, chromotropic acid, H - acid, J - acid, dinaphthyl J-acid, N-benzoyl J-acid, 2 : 8 : p 6-acid, 1-amino-8-naphthol-4-sulphonic acid, N-(4 - oxy - 3 - carboxyphenyl) - J - acid, N - phenyl-2 : 8 : 6-acid, dinaphthyl 2 : 8 : 6-acid are treated with a solution of caustic soda, copper sulphate, tartaric acid and grape sugar, or with alkaline grape sugar and a copper salt of an aliphatic aminocarboxylic acid, e.g. aminoacetic acid (cf. Specification 470,356). Examples of dyeing regenerated cellulose and cotton are given. Samples have been furnished under Sect. 2 (5) of dyestuffs made (1) by treating the azo dye 5-nitro-2-aminophenol --> J-acid --> resorcinol \sM p-aminosalicylic acid with caustic soda, copper sulphate, tartaric acid and grape sugar; (2)-(4) by treating the dyestuffs 5-nitro-2-amino-1-methoxybenzene --> (N-m-carboxyphenyl)-2 : 8 : 6-acid, 1-naphthol-3 : 6-disulphonic acid or 2-naphthol - 5 - 7 disulphonic acid with alkaline glucose and ammoniacal copper sulphate. Specifications 295,594, [Class 2 (iii)], and 425,367 also are referred to.