C.I. Acid Brown 92

Preparation

65% 4-Nitrobenzenamine? and 35% M-nitroaniline diazo, in acid conditions and 60% 4-Amino-5-hydroxynaphthalene-2,7-disulfonic acid?and 40% 7-Amino-4-hydroxynaphthalene-2-sulfonic acid coupling, its product in alkaline conditions and diazo 4-Aminobenzenesulfonic acid coupling, and then will the nitro reduction, diazotization, Coupled with resorcinol, product again with diazo 3,4′-Disulfo-4-aininoazobenzene and 75% 2-Amino-5-nitrobenzenesulfonic acid coupling, and then and diazo of 4-Nitrobenzenamine coupling.

Properties and Applications

Dark brown. Part of the soluble in water for brown, not soluble in alcohol. In the sulfuric acid for to black, diluted brown for olive. The dye solution to join strong hydrochloric acid for olive brown, add thick for blue-black sodium hydroxide solution.