disodium (3Z)-3-[[4-(4-anilino-3-sulfonato-phenyl)diazenylnaphthalen-1-yl]hydrazinylidene]-4-oxo-naphthalene-1-sulfonate

5-Amino-2-(phenylamino)benzenesulfonic acid diazo, and Naphthalen-1-amine coupling, its product to diazo, coupled with the 4-Hydroxynaphthalene-1-sulfonic acid.

navy blue light to dark. Soluble in water for red light navy blue, in very low in alcohol solubility. The strong sulfuric acid for blue-ray black, diluted into the opacity of the navy blue. In water solution to join 10% of sulfuric acid as green; Add 10% of sodium carbonate solution to the color no effect.