GB306843A - Process for the manufacture of azo dyestuffs containing chromium - Google Patents

Abstract

306,843. I. G. Farbenindustrie Akt.- Ges. Feb. 25, 1928, [Convention date]. Azo dyes, soluble chromium compounds of: lakes.-Azo dyes obtained by coupling diazo compounds with the methyl pyrazolones or pyrazolone carboxylic acids derived from salicylic sulphones as described in Specification 245,765 are converted into soluble chromium compounds by boiling with chromium salts. The products dye wool m even clear greenish yellow snades fast tolight, fulling, perspiration, steaming, and car. bonizing, and are suitable for the preparation of lakes on account of their fastness to light, water and lime. In examples the soluble chromium compounds of the following dyestuffs are prepared by boiling the dyestuffs under reflux with chromium formate solution :-(1) 2-chloro-4- toluidine # the methylpyrazolone from 4<1>-oxy- 3<1> - carboxy-2-aminodiphenylsulphone-4-sulphonic acid; (2) aniline-3-sulphonic acid # the same methylpyrazolone. Aniline, toluidines, xylidines, naphthylamines, and sulphonic acids, sulphonamides, sulphonanilides halogen derivatives, and carboxylic acids thereof may be used as diazo components, and other methyl pyrazolones or pyrazolone carboxylic acids from 4<1>-oxy-3<1>-carboxy-2-aminodiphenylsulphone or sulphonic or other derivatives thereof may be used as coupling components.