Benzoic acid, 3-[[4-[(1,8-dihydroxy-4-sulfo-2-naphthalenyl)azo]-1-naphthalenyl]azo]-2(or 6)-hydroxy-, disodium salt

3-Amino-2-hydroxybenzoic acid?diazo, and Naphthalen-1-amine coupling, its product to diazo, and 4,5Dihydroxynaphthalene-1-sulfonic acid coupling.

dark blue light green. Soluble in water for dark, and adequate soluble in ethanol to blue. The strong sulfuric acid in turquoise, diluted into purple. In water solution to join strong hydrochloric acid for violet black; Add thick sodium hydroxide solution for dark.

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