2-Hydroxy-5-[[4'-[(2-hydroxy-3,6-disulfo-1-naphtyl)azo]-1,1'-biphenyl-4-yl]azo]benzoic acid trisodium salt

4-(4-Aminophenyl)benzenamine double nitriding, first with 2-Hydroxybenzoic acid coupling, again with 3-Hydroxynaphthalene-2,7-disulfonic acid coupling.

red red to blue light. Slightly soluble in water for pink, soluble in ethanol, insoluble in other organic solvents. The strong sulfuric acid to red light purple, orange for diluted. The dye solution with strong hydrochloric acid is palm red light, precipitation; Add thick sodium hydroxide solution have yellow precipitation.

Standard	Acid Resistance	Alkali Resistance	Light Fastness	Soaping		Water
				Fading	Stain	Fading	Stain
ISO	4	4-5	1-2	2-3		3