disodium 5-hydroxy-6-[(4-sulphonatonaphthyl)azo]naphthalenesulphonate

4-Aminonaphthalene-1-sulfonic acid diazo, and 5-Hydroxynaphthalene-1-sulfonic acid coupling.

blue-ray red. Soluble in water for product red, slightly soluble in ethanol, acetone, soluble fiber element, insoluble in other organic solvents. The strong sulfuric acid for red light blue, pink solution diluted and appear to precipitate; In nitric acid, the orange into yellow solution. Its water solution to join strong hydrochloric acid for product red; Add sodium hydroxide for product red.

Standard	Light Fastness	Soaping		Persperation Fastness	Oxygen bleaching		Fastness to seawater
		Fading	Stain		Fading	Stain	Fading	Stain
ISO	3	2	5	2	1	4	3	2