3-Amino-4-[[4'-[(6-amino-1-hydroxy-3-sodiosulfo-2-naphthalenyl)azo]-1,1'-biphenyl-4-yl]azo]naphthalene-2,7-disulfonic acid disodium salt

4-(4-Aminophenyl)benzenamine double nitriding, first coupling with ?3-Aminonaphthalene-2,7-disulfonic acid, and then in alkaline conditions and 7-Amino-4-hydroxynaphthalene-2-sulfonic acid coupling.

blue-ray red. Soluble in water for wine red, soluble in ethanol for red orange. In the dark for the strong sulfuric acid or purple, for the red light brown after diluted. Dye with strong hydrochloric acid solution for the red light brown, have precipitation; Add thick sodium hydroxide solution for red light orange brown.

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