dye|World dye variety

Name:C.I.Direct Brown 21,C.I.30155

Molecular Structure: trisazo class

C.I.Direct Brown 21,C.I.30155,CAS 6442-05-3,732.63,C35H22N6Na2O8S,Congo Brown R

Molecular Formula:C₃₅H₂₂N₆Na₂O₈S

Molecular Weight: 732.63

CAS Registry Number:6442-05-3

Manufacturing Methods :  4-(4-Aminophenyl)benzenamine double nitriding, first coupled with 2-Hydroxybenzoic acid, and then coupled with Resorcinol , 4-Hydroxynaphthalene-1-sulfonic acid diazo, and the generation of single azo product matches.

Properties and Applications: brown. Soluble in water for yellow brown, and adequate soluble in alcohol. The strong sulfuric acid for purple, diluted is shallow brown. The dye solution to join strong hydrochloric acid have yellow brown precipitation; Add thick sodium hydroxide solution for orange red to big red.

List of Suppliers:

Congo Brown R ( Bayer Group )