GB325485A - Improvements in the manufacture and production of azo dyestuffs - Google Patents

Abstract

325,485. Johnson, J. Y., (I. G. Farbenindustrie Akt.-Ges.). Nov. 12, 1928. Azo dyes and soluble metal compounds thereof. - Azo dyestuffs are obtained by coupling diazotized aminosulphosalicylic acids with such monooxybenzenes, containing not more than one further nucleus (and excepting naphthols), as are free from carboxylic and unsubstituted amino groups and are substituted in p-position to the hydroxy group. Specified phenols' are p-cresol, hydroquinone monomethyl ether, 2 : 4-dimethylphenol, p - hydroxydiphenylmethane, 4 - acetylaminophenol, and p-chlor-m-cresol. The products dye evenly and have good fastness to light, and the metal compounds obtainabe therefrom by treatment in substance, in the dyebath, or on the fibre, with agents yielding metal have increased fastness' properties. The following examples are specified. (1) The dyestuff p-aminosulphosalicylic acid (COOH : OH : NH2 : SO3H=1 : 2 : 5 : 4) # p-cresol dyes wool yellow, and its chromium compound produced in substance, in the dyebath, or on the fibre gives dyeings very fast to washing, fulling, and light. (2) The dyestuff p-aminosulphosalicylic acid # 2 : 4-dimethylphenol gives on wool a redder dyeing than the dyestuff of example (1); its chromium compound gives very even dyeings, fast to washing and fulling and is suitable for dyeing leather; its copper compound dyes wool yellow. o-Aminosulphosalicylic acid (COOH : OH : NH2 : SO3H=1 : 2 : 3 : 4) is also specified as diazo component giving redder shades than the p-aminosulphosalicylic acid. Reference has been directed by the Comptroller to Specifications 2468/99, 13204/15 and 269,934.