GB541692A - Manufacture of chromium complex compounds of ortho-oxyazodyestuffs - Google Patents

Abstract

541,692. Dyes. SOC. OF CHEMICAL INDUSTRY IN BASLE. June 5, 1940, Nos. 9832 and 9833. Convention dates, June 6, 1939, and May 6, 1940. [Classes 2 (iii) and 15 (ii)] Water soluble chromium complex compounds of azo dyestuffs of the general formula HO-R 1 -N=N-R 2 -OH, wherein R 1 represents a residue of a benzene monosulphonic acid, R 2 - OH represents the residue of a 1-naphthol carrying at least one halogen atom, and both hydroxy groups are in o-position to the azo group, are obtained by the action thereon in an alkaline medium of an agent yielding chromium in presence of a salt of an aliphatic hydroxycarboxylic acid, e.g. tartaric acid. Specified diazo components are 3:6- dichloro- 2-aminophenol-4-sulphonic acid (of which the diazo compound is produced in solution by adding sodium carbonate to a solution of diazotized 1:3:6-trichloro- 2-aminobenzene-4-sulphonic acid), 4-chloro- or bromo-2-aminophenol-6- sulphonic acid, 6-chloro-2-aminophenol-4-sulphonic acid and 4-methyl-2-aminophenol-5- or 6-sulphonic acid. Specified coupling components are the 5:8-dichloro-, 8-chloro- and 8-bromoderivatives of 1-naphthol. The products dye animal fibres, e.g. wool or silk, in shades which are specially fast to fulling and pot ing. Examples relate to (1) the chroming of the dyestuff, 3:6-dichloro-2-aminophenol-4- sulphonic acid# 5:8-dichloro-1-naphthol by boiling it with an aqueous solution of chromium sodium tartrate, such solution being obtained by adding caustic soda solution to a solution obtained by boiling an aqueous solution of tartaric acid with the moist precipitate produced by adding sodium carbonate to an aqueous solution of chromium sulphate, (2) the dyeing of wool with this dyestuff from a boiling aqueous bath containing sulphuric acid. Specification 460,561 is referred to.