Chromate(3-), bis[2-(hydroxy-κO)-5-[(4-sulfo-1-naphthalenyl)azo]benzoato(3-)-κO]-, trisodium, (T-4)-

4-Aminonaphthalene-1-sulfonic acid diazo, coupled with 2-Hydroxybenzoic acid?and then translate into chromium complex.

red light yellow. Soluble in water for green light yellow, slightly soluble in ethanol for green light yellow. The strong sulfuric acid for product red, diluted into yellow. Its water solution to join strong hydrochloric acid for yellow; Add thick sodium hydroxide solution for yellow light brown.

Standard	Light Fastness	Soaping		Persperation Fastness	Oxygen bleaching		Fastness to seawater
		Fading	Stain		Fading	Stain	Fading	Stain
ISO	5	4		4-5			4-5