Direct Orange 40

in reflux conditions (or a little take pressure), in sodium hydroxide solution will be (E)-2-(2-sulfo-4-nitrostyryl)-5-nitrobenzenesulfonic acid with two 4-Aminobenzenesulfonic acid sodium diazotization and 2-Amino-4-methylanisole coupled with product heat.

dark red light orange. Soluble in water for orange to orange brown, slightly soluble in ethanol, insoluble in other organic solvents. The strong sulfuric acid for Gray light purple to blu-ray black, diluted to olive brown for yellow; In nitric acid for yellow olive brown. The dye solution to join strong hydrochloric acid for olive brown to black light brown; Add thick sodium hydroxide solution for orange. Used for cellulose fiber dyeing and printing, also used in leather and paper color

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