disodium 5-[(4-nitro-2-sulphonatophenyl)azo]salicylate

Preparation

2-Amino-5-nitrobenzenesulfonic acid diazotization, and 2-Hydroxybenzoic acid?coupling.

Properties and Applications

orange. Soluble in water for orange, soluble in ethanol for orange. In concentrated sulfuric acid for yellow orange, after diluted solution for yellow, with pale yellow precipitation. Dye aqueous solution to join concentrated hydrochloric acid for light color solution; Join concentrated sodium hydroxide solution for blue light red.

Standard	Ironing Fastness	Light Fastness	Fulling		Persperation Fastness	Soaping	Water
			Alkali	Acid
ISO	3	5	4	1	3-4	3-4