disodium 5,5'-[thiobis(phenyleneazo)]disalicylate

Preparation

4-(4-Aminophenylthio)benzenamine and 4-(2-Aminophenylthio)benzenamine diazotization, and 2-Hydroxybenzoic acid?(2 Moore) coupling.

Properties and Applications

dark red light yellow. Soluble in water for green light yellow, slightly soluble in Cellosolve, almost insoluble in Etanol and Acetone. In concentrated sulfuric acid to dark red sauce, dilution after light yellow, In concentrated nitric acid for olive green. Dye aqueous solution to join concentrated hydrochloric acid for light yellow, Join concentrated Sodium hydroxide solution for golden orange.

Standard	Ironing Fastness	Light Fastness	Fulling		Persperation Fastness	Soaping	Water
			Alkali	Acid
ISO	4-5	4-5	4-5	2-3	4-5	4-5	5
AATCC	3	6	5		5	4-5