2-Naphthalenesulfonic acid, 4-hydroxy-3-4-(4-nitro-2-sulfophenyl)azo-6(or 7)-sulfo-1-naphthalenylazo-7-(phenylamino)-, trisodium salt

Preparation

2-Amino-5-nitrobenzenesulfonic acid diazo, and 5-Aminonaphthalene-2-sulfonic acid and 8-Aminonaphthalene-2-sulfonic acid coupling, its product to diazo, in alkaline conditions and 4-Hydroxy-7-(phenylamino)naphthalene-2-sulfonic acid coupling.

Properties and Applications

blue. The strong sulfuric acid for green, diluted dark for; In the light of nitric acid for palm orange solution. The dye solution to join strong hydrochloric acid for dark, precipitation; Add thick sodium hydroxide solution for blue precipitation.

Standard	Acid Resistance	Alkali Resistance	Light Fastness	Soaping		Water
				Fading	Stain	Fading	Stain
ISO	5	4-5	3	2		2