Benzoic acid,2-hydroxy-5-[2-(4-sulfo-1-naphthalenyl)diazenyl]-, sodium salt (1:2)

Preparation

4-Aminonaphthalene-1-sulfonic acid diazotization, and 2-Hydroxybenzoic acid coupling.

Properties and Applications

dark red light yellow. Soluble in water for green light yellow, moderate soluble in ethanol for green yellow. In concentrated sulfuric acid for magenta, yellow as after diluted. Dye aqueous solution to join concentrated hydrochloric acid for yellow; Join concentrated Sodium hydroxide solution for yellow brown.

Standard	Ironing Fastness	Light Fastness	Fulling		Persperation Fastness	Soaping	Water
			Alkali	Acid
ISO	2-3	4-5	4-5		5	4-5	5