Direct Blue 31
Name:C.I.Direct Blue 31,C.I.23690
Molecular Structure: Double azo class
Molecular Formula:C34H24N5Na3O11S3
Molecular Weight: 843.75
CAS Registry Number:5442-09-1
Manufacturing Methods : 3,3′-Dimethylbenzidine double nitriding, first and 4,5-Dihydroxynaphthalene-2,7-disulfonic acid coupling, again with 4-Hydroxynaphthalene-1-sulfonic acid coupled
Properties and Applications: red light blue. Soluble in water for deep purple, slightly soluble in alcohol for red light purple. The strong sulfuric acid for green light blue, purple for red after diluted. The dye solution to join strong hydrochloric acid for deep purple; Add thick sodium hydroxide solution for purplish red color.
Standard | Acid Resistance | Alkali Resistance | Light Fastness | Soaping | Water | ||
Fading | Stain | Fading | Stain | ||||
ISO | 5 | 3 | 2 | 1-2 | 2 |
List of Suppliers:
Dianil Blue 2R( Farbwerke vorm. Meister Lucius &Brtining )