Product description: Direct Fast Blue B2RL Name:C.I.Direct Blue 71,C.I.34140 Molecular Structure: trisazo class C.I.Direct Blue 71,C.I.34140,CAS 4399-55-7,1029.87,C40H23N7Na4O13S4,Direct Fast Blue 2RL,Direct Fast Blue B2R,Direct Fast Blue B2RL,Direct Navy BlueL-3RB,Sirius Blue S-BRR,Solophenyl Blue GL Molecular Formula:C40H23N7Na4O13S4 Molecular Weight: 1029.87 CAS Registry Number:4399-55-7 1.Properties and Applications: dark blue. Blue gray powder. Soluble in water for blue, solubility of 10 g/L (60 ℃), 20 g/L (97 ℃), slightly soluble in soluble fiber element, soluble in ethanol, insoluble in other organic solvents. The strong sulfuric acid for blue to to black, red after diluted purple precipitation. Dye with strong hydrochloric acid solution for blue precipitation; Add thick sodium hydroxide solution for red light purple, have precipitation. Cellulose fiber of dyeing, dye devoured the gender is good, the temperature in the 80-100 ℃, affinity is the largest. Discharge sex is very good. In dye bath of copper ions in tiny change color (4 ~ 5 level), meet iron ion colored light basically unchanged (level 5). SDC classification for a class B. Cotton neutral white was a category 4, viscose neutral white for 4 ~ 5 level, cotton and viscose alkaline white are 5 levels. Widely used in viscose fiber dyeing, also used in viscose/PVA blends, cotton, and the carpet of dyeing and printing. Also used in leather, paper, soap, cheese, protein and formaldehyde resin color. Standard Acid Resistance Alkali Resistance Light Fastness Soaping Water Fading Stain Fading Stain ISO 4 4-5 5 2 2 AATCC 2 4 4-5 1-2 2 2.International Similar brand Direct Fast Blue 2RL Direct Fast Blue B2R Direct Fast Blue B2RL Direct Navy BlueL-3RB ACDI Blue FFC Cone Ambidirect Blue R Arid Blue FFC HI Cone. Atul Direct Supra Light Blue G Best Direct Blue BRR