Direct Scarlet 4b / Direct Red 28
|Min. Order (kg)||FOB Price|
|100+||US $1 / kg|
CAS Registry Number:573-58-0
Manufacturing Methods : commonly known as Congo Red. 4-(4-Aminophenyl)benzenamine double nitriding, and 4-Aminonaphthalene-1-sulfonic acid (2 Moore) coupled.
Properties and Applications: yellow light red. Tan powder. Soluble in water for yellow light red solution, soluble in ethanol for orange, soluble in acetone. In the strong sulfuric acid as dark blue, diluted into shallow blue, blue precipitation. Dyes to acetic acid solution for blue purple, have red light blue precipitation; Add thick sodium hydroxide solution for yellow. This product acid resistance and sun fastness is poor. The acid, alkali is very sensitive. Cellulose fiber of dyeing, the dye absorption rate as well, a 80 ° C affinity when the largest. This article covers the gender is good, hard to sensitive. Dyeing copper ions in colored light yellow dark; Iron ion in a yellow light. Mainly used in viscose, such as cotton, wool, silk cellulose fiber dyeing and not used in printing, also can be used for biological and pulp color.