Direct Brown 78

in reflux conditions (or a little take pressure), in sodium hydroxide solution will be (E)-2-(2-sulfo-4-nitrostyryl)-5-nitrobenzenesulfonic acid with Sodium 4-aminobenzenesulfonate??diazotization?and Naphthalen-1-amine coupled with heating products. Reaction to the different proportion of material that get different commodity dye.

red light brown. Soluble in water for orange brown, slightly soluble in alcohol. The strong sulfuric acid in blue light green light for black to black, diluted to olive brown for yellow light. The dye solution to join strong hydrochloric acid have yellow olive brown precipitation; Add thick sodium hydroxide solution for palm light orange.

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