2-Naphthalenesulfonic acid, 5-[[4-[[4-amino-6(or 7)-sulfo-1-naphthalenyl]azo]-1-naphthalenyl]azo]-6-hydroxy-, disodium salt

5-Acetamido-8-amino-2-naphthalenesulfonic acid?diazo, and Naphthalen-1-amine coupling, product to diazo, and 6-Hydroxynaphthalene-2-sulfonic acid coupling, and then hydrolysis acetyl amino.

dark blue. Soluble in water for dark red light blue, not soluble in alcohol. The strong sulfuric acid in the navy for, for the red light purple diluted. The dye solution with 10% sulfuric acid micro turn dark; Add thick tiny change sodium hydroxide solution green.

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