4-[[4-[(4-Aminophenyl)azo]-7-sodiosulfo-1-naphthalenyl]azo]-2'-hydroxy[1,1'-azobisnaphthalene]-6,6'-disulfonic acid disodium salt

2-(4-Aminophenylamino)-2-oxoacetic acid diazo, and 8-Aminonaphthalene-2-sulfonic acid coupling, again diazo, and 5-Aminonaphthalene-2-sulfonic acid coupling, product to diazo, and 6-Hydroxynaphthalene-2-sulfonic acid coupling, and then 2-(4-Aminophenylamino)-2-oxoacetic acid hydrolysis base.

red light blue. Soluble in water for blue purple to navy, soluble in ethanol. The strong sulfuric acid for violet, diluted for purple, have red light blue precipitation. The dye solution to join strong hydrochloric acid have blue-ray black precipitation; Add thick sodium hydroxide solution have navy precipitation.

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