2-Naphthalenesulfonic acid, 4-hydroxy-3-[(2-hydroxy-5-nitrophenyl)azo]-7-(phenylamino)-, monosodium salt

Preparation

2-Amino-4-nitrophenol diazotization, in alkaline condition and 4-Hydroxy-7-(phenylamino)naphthalene-2-sulfonic acid coupling.

Properties and Applications

blue black. Soluble in water for magenta, right amount soluble in ethanol for orange brown. In concentrated sulfuric acid for magenta, dilution after red brown. Dye aqueous solution to join concentrated hydrochloric acid have bordeaux red precipitation; Join concentrated sodium hydroxide solution for brown light magenta precipitation.

Standard	Ironing Fastness	Light Fastness	Fulling		Persperation Fastness	Soaping	Water
			Alkali	Acid
ISO	5	7-8	4-5		4-5	5	5