Introduction | Direct Black 19 is a black powder. Water solubility is very good, the aqueous solution is green light black, adding concentrated alkali solution is green light blue, adding 10% sulfuric acid color slightly red. Slightly soluble in ethanol and acetone. Dark brown in concentrated nitric acid, green black in concentrated sulfuric acid, red black precipitation after dilution. When staining, the color light of copper ion was slightly green, and the color light of iron ion was slightly changed. |
Use | direct suntan black G is one of the main varieties of black dyes. It is mainly used for dyeing and direct printing of cotton, viscose fiber, cotton, viscose fiber, silk and wool interwoven and blended fabrics. Mainly dyed black, printing is generally used in gray and black, can also be combined with a variety of brown dye depth of coffee and other colors, a small amount of light for color, to increase the color. When dyeing wool viscose fiber blended fabric, it can be dyed with neutral black BRL in the same bath to obtain uniform color. It can also be used in the same bath with disperse dyes to dye polyester-viscose blended fabrics. The dyeing rate is good, the transfer dyeing is slightly poor, and the fixing agent Y and the fixing agent M can be used after dyeing, but the color light is slightly green, and the color light can be changed by the Urea Formaldehyde Resin finishing, and the wet treatment fastness can be improved. |
production method | with M-phenylenediamine, P-nitroaniline and H acid as raw materials, P-nitroaniline was diazotized firstly, the first coupling with the H acid is then carried out in a weakly acidic medium. A second coupling with the H acid is then carried out under weakly basic conditions. The nitro group was reduced with a sulfide base and diazotized, and the product was obtained by a third coupling with M-phenylenediamine. After salting out, filtration, drying, grinding to get the finished product.. Add 400L of water, 650kg of hydrochloric acid (30%) and 276kg of p-nitroaniline (100%) into the diazonium pan, heat up to 80 ℃, stir and dissolve completely, then add 800-1000kg of ice and cool down to 1-2 ℃, 140.8kg sodium nitrite (100%) was quickly added under the liquid, and the reaction temperature was maintained at 16 ° C. For 40min until the solution was transparent. After taking 325kg (100%) of H acid and of water for beating, it was quickly added to the above diazo solution, and the reaction temperature was maintained at less than or equal to 18 °c for about 40-50min. Subsequently, ice was added to cool down to 8-10 °c, and 300-320kg of soda ash powder was rapidly added (added in about 10min) to maintain ≤ 20 °c to complete the second coupling reaction. 235kg of sodium sulfide and 1000kg of water were dissolved by heating, then naturally cooled to 50 ° C., added to the above coupling solution, heated to 35 ° C., and reacted for 1-2H. At the end of the reaction, add 1000kg hydrochloric acid (30%) Acid Analysis, about 1H added. Then, the temperature was raised to 60 ° C. To drive sulfur dioxide for 4H and filtered. Take filter cake, 1000L of water and 58kg of soda ash, then raise the temperature to 60 ℃, suction filter, and add 100% of sodium nitrite () to the filtrate. Add 550kg hydrochloric acid (30%), ice and water to another heavy nitrogen Pan, cool to ≤ 18 ℃, add the above filtrate containing sodium nitrite, add it for about 1H, and continue the reaction for 3H, the end point was measured by potassium iodide test paper. Subsequently, ice was added and the temperature was lowered to 5-6 ° C., soda ash powder was added, pH was adjusted to 6.5, and 100% of M-phenylenediamine () was added and reacted at 20 ° C. For 2H. Filter, filter cake with water 1500L, soda ash 20kg beating, drying, to obtain about 900kg of dye. |