6420-41-3

6-Aminonaphthalene-2-sulfonic acid diazo, in acid conditions and N,N’-bis(4-hydroxy-2-sulfonaphthalene-7-yl)urea coupling, aniline diazo again, in alkaline conditions and coupled product matches.

yellow light red. Soluble in water for colourful red, slightly soluble in soluble fiber element, soluble in ethanol is shallow Red time Insoluble in other organic solvents. The strong sulfuric acid for purple, Pink is diluted, orange precipitation; The dye solution to join strong hydrochloric acid for colourful red; Add thick Red wine for sodium hydroxide solution.

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