3-Hydroxy-4-[(2-methylphenyl)azo]naphthalene-2,7-disulfonic acid disodium salt

O-Methylaniline diazo, coupled with 3-Hydroxynaphthalene-2,7-disulfonic acid.

yellow light red. Soluble in water, slightly soluble in ethanol for orange red. The strong sulfuric acid explicit orange red, orange is still the diluted. In water solution to join strong hydrochloric acid for orange red; Add sodium hydroxide for orange brown.

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