sodium 3-[(1,5-dihydroxy-2-naphthyl)azo]-4-hydroxy-5-nitrobenzenesulphonate

Preparation

3-Amino-4-hydroxy-5-nitrobenzenesulfonic acid diazotization, and Naphthalene-1,5-diol?coupling.

Properties and Applications

black. Soluble in water for bordeaux red, right amount soluble in ethanol for orange red brown. In concentrated sulfuric acid for purple brown, dilution for red wine. Dye aqueous solution to join concentrated hydrochloric acid for red brown; With strong caustic is purple.

Standard	Ironing Fastness	Light Fastness	Fulling		Persperation Fastness	Soaping	Water
			Alkali	Acid
ISO	5	6	5	3	5	5	5