GB190210243A - Manufacture of Azo-dyestuffs. - Google Patents

Abstract

10,243. Imray, O., [Farbwerke vorm. Meister, Lucius, & Br³ning]. May 3. Dyes, artificial.-(1) Monoazo dyes, which are stable and are apparently derived from a 1 : 8- amidonaphthol sulphonic acid, are produced by heating with mineral acids the monazo dyes obtained from 1:8-naphthylenediamine sulphonic acid. An example is given in which the dye-stuff obtained by combining diazotized naphthionic acid with a molecular proportion of 1 : 8 : 4- naphthylenediamine sulphonic acid in acetic acid or feebly alkaline solution is heated with dilute hydrochloric acid at about 90‹ C. for 18 hours. The product dyes wool violet. Dyes from 1 : 8 : 4- naphthylenediamine sulphonic acid and picramic acid, o-amidophenol-p-sulphonic acid, o amidop-cresol-o-sulphonic acid, o amido-o-nitrophenolp-sulphonic acid, p - nitro - o - amidophenol, and chloramidophenol sulphonic acids [OH : NA2 : SO3H :Cl and OH : NH2 : Cl : SO3H = 1 : 2 : 4 : 6] are also similarly treated. (2) Disazo dyes are produced by combining a diazotized amine, such as diazotized aniline, p-toluidine, alpha- or #-naphthylamine, or p-nitraniline in acid solution, with the foregoing products, especially those obtained from an amidosulphonic acid, for example with those obtained by the action of mineral acids upon the monazo dyes derived from 1:8:4-naphthylenediamine sulphonic acid and naphthionic acid or sulphanilic acid.