sodium 6-(1-naphthylazo)naphthalene-2-sulphonate

6-Aminonaphthalene-2-sulfonic acid diazo, and Naphthalen-1-amine coupling, and then diazo, and with ethanol and sodium carbonate common heating, away with amino.

brown. Water solution is yellow brown, but water-soluble not beautiful, easily soluble in ethanol is yellow light brown. In the dark for the strong sulfuric acid (purple and product red), after diluted for brown. In aqueous solution to join strong hydrochloric acid for yellow olive brown; Add thick hydrogen for orange brown, oxidation solution.

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