GB410765A - Manufacture of azo-dyestuffs - Google Patents

Abstract

Azo dyes are obtained by coupling in alkaline medium a diazo or diazoazo compound containing no hydroxyl group in o-position to the diazo or azo group with a nitroaryloxynaphthyl-1 : 2-triazolesulphonic acid. The products dye chrome or vegetable tanned leather uniformly from an acid bath. The triazole components are obtainable by the process of Specification 410,857. The production of the following dyestuffs is described in examples:--(1) sulphanilic acid-->(alkaline) 4<1>-nitrophenyl-5-oxynaphthyl-1 : 2-triazole-7-sulphonic acid, which dyes chrome or vegetable tanned leather bluish red, fast to light; (2) anthranilic acid --> (alkaline) 4<1> - nitrophenyl - 5 - oxynaphthyl - 1 : 2 : triazole - 7 - sulphonic acid, which dyes chrome or vegetable tanned leather bluish red; if the diazo component is replaced by 5-nitroanthranilic acid, the dyeings are brown-red; (3) 4 - aminoazobenzene - 4<1> - sulphonic acid --> (alkaline) 4<1> - nitrophenyl - 5 - oxynaphthyl - 1 : 2 - triazole - 7 - sulphonic acid, which dyes chrome or vegetable tanned leather red-brown, fast to light, if the coupling component is replaced by 4<1>-nitrophenyl-8-oxynaphthyl-1 : 2-triazole-6-sulphonic acid, similar dyeings are obtained; (4) 2 - aminonaphthalene - 4 : 8 - disulphonic acid --> 1-aminonaphthalene --> (alkaline) p 4<1> - nitrophenyl - 5 - oxynaphthyl - 1 : 2 - triazole - 7 - sulphonic acid, which dyes chrome or vegetable tanned leather currant shades. Specification 22397/00, [Class 2], also is referred to. The Specification as open to inspection under Sect. 91 is not restricted to the use of diazo or diazoazo compounds as above defined and comprises also examples of the production of the following dyestuffs (a) 6 - nitro - 2 - aminophenol - 4 - sulphonic acid --> (alkaline) 4<1> - nitrophenyl - 5 - oxynaphthyl - 1 : 2 - triazole - 7 - sulphonic acid, which dyes chrome or vegetable tanned leather red-brown; (b) 4 : 6 - dinitro - 2 - aminophenol --> (alkaline)4<1>-nitrophenyl - 5 - oxynaphthyl - 1 : 2 - triazole - 7 - sulphonic acid, which dyes chrome tanned leather deep black; (c) 4 : 6 - dinitro - 2 - aminophenol --> (alkaline) 4<1> - nitrophenyl - 8 - oxynaphthyl - 1 : 2 - triazole - 6 - sulphonic acid, which dyes chrome or vegetable tanned leather deep black; (d) 4 : 6 - dinitro - 2 - aminophenol --> (alkaline) 3<1> - nitrophenyl - 8 - oxynaphthyl - 1 : 2 - triazole - 4 - sulphonic acid, which dyes chrome or vegetable tanned leather dark grey; (e) 4 : 6 - dinitro - 2 - aminophenol --> (alkaline) 2<1> - oxy - 3<1> : 5<1> - dinitropheny - 5 - oxynaphthyl - 1 : 2 - triazole - 7 - sulphonic acid, which dyes chrome or vegetable tanned leather black. This subject-matter does not appear in the Specification as accepted.