2-Naphthalenesulfonic acid, 5(or 8)-amino-8(or 5)-[(4-hydroxyphenyl)amino]-, reaction products with sodium sulfide (Na2(Sx))

Preparation

8-Amino-5-(4-hydroxyphenylamino)naphthalene-2-sulfonic acid and aqueous Sodium polysulfide heating, in 107 ~ 108 ℃ under reflux 2 4 hours, will be part of the precipitation in the Sodium sulfide of dye solution, blowing air redeposition. This indophenol?is from 8-Amino-5-nitronaphthalene-2-sulfonic acid and where did 5-Aminonaphthalene-2-sulfonic acid and where did 4-Aminophenol with Sodium hypochlorite oxidation of mixture, then use Sodium sulfide reduction and have to.

Properties and Applications

green light blue. Blue gray powder. Slightly soluble in water, not soluble in alcohol and benzene, soluble in Sodium sulfide solution for olive. In concentrated sulfuric acid for dark blue, dark blue precipitation after dilution. Dyeing content in alkaline insurance powder for dark yellow, after oxidation can restore the original colour and lustre; In Sodium hypochlorite solution all fade, join concentrated sulfuric acid into dark blue. Mainly used for cotton, hemp, viscose fiber dyeing and printing.

Standard	Acid Resistance	Alkali Resistance	Light Fastness	Fulling	Persperation Fastness	Soaping
						Moderate	Severe
ISO	3-4	4	6	3-4	(Alkali)4-5	4	2
AATCC	5	4	5-6	3			3