Direct Red 33
Name:C.I.Direct Red 33,C.I.22306
Molecular Structure: Double azo class
C.I.Direct Red 33,C.I.22306,CAS 6253-15-2,627.54,C29H19N5Na2O7S
Molecular Formula:C29H19N5Na2O7S
Molecular Weight: 627.54
CAS Registry Number:6253-15-2
Manufacturing Methods : 4-(4-Aminophenyl)benzenamine double nitriding, first with 2-Hydroxybenzoic acid coupling, and then in alkaline conditions and 7-Amino-4-hydroxynaphthalene-2-sulfonic acid coupling.
Properties and Applications: red. Soluble in water for red, soluble in ethanol for orange, insoluble in other organic solvents. The strong sulfuric acid for purple, diluted for brown, have precipitation. The dye solution to join strong hydrochloric acid for red light brown, have precipitation; Add thick red to orange sodium hydroxide solution to brown.
| Standard | Acid Resistance | Alkali Resistance | Light Fastness | Soaping | Water | ||
| Fading | Stain | Fading | Stain | ||||
| ISO | 3-4 | 3-4 | 3 | 3 | 2-3 | ||
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