7-Amino-3-[[4-[(4-amino-3-sodiosulfophenyl)azo]-1-naphthalenyl]azo]-4-hydroxynaphthalene-2-sulfonic acid sodium salt

3-(4-Amino-2-sulfophenylamino)-2,3-dioxopropanoic acid diazo, and Naphthalen-1-amine coupling, product to diazo, in alkaline conditions and 7-Amino-4-hydroxynaphthalene-2-sulfonic acid coupling, and then 2-(4-Aminophenylamino)-2-oxoacetic acid hydrolysis base.

red light blue. Soluble in water for darkness purplish red color, soluble in ethanol for purple. The strong sulfuric acid for blue-ray green, diluted for purple. The dye solution to join strong hydrochloric acid has the purple precipitation; Add thick sodium hydroxide solution for red sauce, precipitation.

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