| production method | with 6-nitro-2-aminobenzothiazole and N-ethyl-N-cyanoethylaniline as raw materials, the former is first diazotized and then coupled with N-ethyl-N-cyanoethylaniline to give the product. The final product was obtained by filtration, grinding and drying.. 9.9kg sulfuric acid and 6-nitro-2-aminobenzothiazole were added to the reactor, and the temperature was raised to 70 ° C. To be completely soluble. Then the temperature was cooled to 0 ℃, and 7kg nitrosyl sulfuric acid was added dropwise within 30min. After addition, the heat preservation was continued for 2H to the end point, and the excess sodium nitrite was decomposed to obtain diazo solution. Add 24.1kg water, N-ethyl-N-(β-cyanoethyl) aniline (40% solution) to the coupling kettle, stir at room temperature until fully soluble, then cool to 0-5 ℃, diazo solution was added for about 30min, and the reaction was continued to the end point. Filtration, washing with water until neutral, and drying gave 13kg of dye. |
