4-Hydroxy-3-[[4'-[(2-hydroxy-8-sodiosulfo-1-naphthalenyl)azo]-1,1'-biphenyl-4-yl]azo]naphthalene-2,5-disulfonic acid disodium salt

4-(4-Aminophenyl)benzenamine double nitriding, first and 7-Hydroxynaphthalene-1-sulfonic acid coupling, and then and 8-Hydroxynaphthalene-1,6-disulfonic acid coupling.

bright purple. Soluble in water for red light purple jade to red, and adequate soluble in alcohol. The strong sulfuric acid for blue, pink is diluted. The dye solution to join strong hydrochloric acid for dark, precipitation; Add thick sodium hydroxide solution for wine red, have precipitation.

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