7-Hydroxy-8-[(4-sulfo-1-naphthalenyl)azo]-1-naphthalenesulfonic acid disodium salt

Preparation

4-Aminonaphthalene-1-sulfonic acid diazo, and 7-Hydroxynaphthalene-1-sulfonic acid?coupling.

Properties and Applications

red. Soluble in water for red, and adequate soluble in alcohol. The strong sulfuric acid to red light purple, diluted in red. In aqueous solution to join strong hydrochloric acid for red; Add thick sodium hydroxide solution for yellow brown.

Standard	Light Fastness	Soaping		Persperation Fastness	Oxygen bleaching		Fastness to seawater
		Fading	Stain		Fading	Stain	Fading	Stain
ISO	3-4			2	1		2
AATCC	3	1		1			1