tetrasodium [mu-[[7,7'-[(3,3'-dihydroxy[1,1'-biphenyl]-4,4'-diyl)bis(azo)]bis[8-hydroxynaphthalene-1,6-disulphonato]](8-)]]dicuprate(4-)

3,3′-Dimethoxylbenzidine double nitriding, and 8-Hydroxynaphthalene-1,6-disulfonic acid (2 Moore) coupling, and then will cream shape dye and water cut copper sulfate and sodium acetate mixing 1.5 days and nights form a tight mixture, again in the 120 ~ 125 ℃ conditions vacuum drying. In this process, the two methoxy groups are replaced by hydroxyl groups.

bright blue. Soluble in water for purple, not soluble in alcohol. The strong sulfuric acid for Tracy in blue, blue for red after diluted. The dye solution to join strong hydrochloric acid for blue precipitation; With strong sodium hydroxide solution for purple solution.

Standard(viscose)	Acid Resistance	Alkali Resistance	Light Fastness	Soaping		Water
				Fading	Stain	Fading	Stain
ISO	4	3-4	6	2-3		2