Diindolo[3,2-b:3',2'-m]triphenodioxazinetrisulfonic acid, 8,18-dichloro-5,15-dihydro-, trisodium salt

9H-carbazol-3-amine and 2,3,5,6-Tetrachlorocyclohexa-2,5 -diene-1,4-dione condensation, its products and 4-Methylbenzene-1-sulfonyl chloride in heat the (207 ~ 209 ℃, 5 hours) closed loop, again with hair smoke sulfuric acid three stlfonation, and as the three sodium salting out.

red light blue. Soluble in water to blue.

Standard	Acid Resistance	Alkali Resistance	Light Fastness	Soaping		Water
				Fading	Stain	Fading	Stain
ISO		4	6-7	3-4		3-4