- Name: Direct Black 22 Molecular Formula: C44H32N13Na3O11S3 Molecular Weight: 1083.97 CAS Number: 6473-13-8 EINECS No.:229-326-3 Properties and Applications: Soluble in water for violet black. The strong sulfuric acid for violet black, dilute black light after brown precipitation; In nitric acid solution for the red light brown in, precipitation. The dye solution to join strong hydrochloric acid have brown light black precipitation; Add thick sodium hydroxide solution for dark blue light red. Mainly used for cotton, viscose, wool/stick,nylon/rayon blended fabric dyeing and printing, also used in leather and paper dyeing.
- Name: C.I.Direct Red 31 Molecular Formula: C32H21N5Na2O8S2 Molecular Weight: 713.65 CAS Number: 5001-72-9 EINECS No.: 225-669-8
Properties and Applications: colourful red blue light. Red brown powder. Soluble in water for product red solution, the solubility of 45 g/L (80 ℃), also can dissolve in fiber element solution, slightly soluble in alcohol for red orange, insoluble in other organic solvents. The dye solution to generate strong hydrochloric acid purplish red precipitate; Add thick sodium hydroxide solution for orange brown. Copper ions in dyeing dim light; Iron ion in micro have change. Mainly used in viscose, such as cotton, silk, polyamide fiber cellulose fiber and viscose/silk blended fabric dyeing, can be used for pulp shading.