Direct Brown 73

4-(4-Aminophenyl)benzenamine double nitriding,first coupled with 2-Hydroxybenzoic acid, and then in alkaline conditions and 4-Amino-5-hydroxynaphthalene-2,7-disulfonic acid?coupling, product to diazo, in alkaline conditions and 6-Amino-4-hydroxynaphthalene-2-sulfonic acid? coupling, its product to diazo, and Benzene-1,3-diamine coupling.

red light brown. Soluble in water for brown. The strong sulfuric acid for purple brown, for yellow brown solution diluted, accompanied by precipitation. The dye solution to join strong hydrochloric acid have dark brown precipitation; Add thick sodium hydroxide solution for brown.

Standard	Acid Resistance	Alkali Resistance	Light Fastness	Soaping		Water
				Fading	Stain	Fading	Stain
ISO	4-5	3	3	4-5		4