4-Hydroxy-3-[[4'-[(1-hydroxy-4-sulfo-2-naphtyl)azo]-1,1'-biphenyl-4-yl]azo]-2,7-naphthalenedisulfonic acid trisodium salt

4-(4-Aminophenyl)benzenamine double nitriding, respectively with the 4-Hydroxynaphthalene-1-sulfonic acid and 4-Hydroxynaphthalene-2,7-disulfonic acid coupling.

purple. Soluble in water for deep purple, slightly soluble in alcohol for red light purple, insoluble in acetone. The strong sulfuric acid for blue, purple for red after diluted. The dye solution to join strong hydrochloric acid for purplish red color; Add thick sodium hydroxide solution in red.

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