6420-44-6

4-Amino-3-methylbenzenesulfonic acid diazo, in acid conditions and N,N’-bis(4-hydroxy-2-sulfonaphthalene-7-yl)urea coupling, O-Anisidine diazo, in alkaline conditions and coupled product matches.

red. Soluble in water for colourful red, soluble in ethanol Reddish orange, insoluble in other organic solvents. The strong sulfuric acid to red light purple, diluted red orange to orange for brown, precipitation. The dye solution to join strong hydrochloric acid for orange to red orange brown, have precipitation; Add thick sodium hydroxide solution have orange brown precipitation.

Standard	Acid Resistance	Alkali Resistance	Light Fastness	Soaping		Water
				Fading	Stain	Fading	Stain
ISO	4-5	4-5	2-3	2		1-2
AATCC	5	5	3	4		2