6771-82-0

1,3-Bis(4-amino-3-sulfophenyl)urea double nitriding, first in acid conditions and 6-Amino-4-hydroxynaphthalene-2-sulfonic acid?coupled, then in alkaline conditions and 4-Hydroxy-7-(phenylamino)naphthalene-2-sulfonic acid coupling.

red light purple. Soluble in water for product red, slightly soluble in alcohol. The strong sulfuric acid for red sauce, diluted for purple. The dye solution to join strong hydrochloric acid for purple, have precipitation; Add thick Red sauce sodium hydroxide solution for wine Red, have precipitation.

Standard	Acid Resistance	Alkali Resistance	Light Fastness	Soaping		Water
				Fading	Stain	Fading	Stain
ISO	3	4	4	1-2		2