sodium 5-[(2-hydroxynaphthyl)azo]naphthalenesulphonate

Preparation

5-Aminonaphthalene-1-sulfonic acid diazo, and Naphthalen-2-ol coupling.

Properties and Applications

red. Soluble in hot water for red, slightly soluble in cold water and ethanol. The strong sulfuric acid to red light purple, diluted precipitation is brown; In nitric acid solution for yellow brown; In a dilute sodium hydroxide solution for yellow brown solution. In water solution to join hydrochloric acid with brown precipitation; Add sodium hydroxide solution to become yellow.

Standard	Light Fastness	Soaping		Persperation Fastness	Oxygen bleaching		Fastness to seawater
		Fading	Stain		Fading	Stain	Fading	Stain
ISO	2-3	2	1	3	1	1	2	3