| Introduction | neutral red 2GL(C.I. Acid red 211) is a basic dye that dyes medium and deep red. Mainly used for dyeing coarse, worsted wool fabrics and wool, can be used for other neutral dyes or brightening dyes to adjust the color light, also used for dyeing silk, nylon, Vinylon and in wool, silk, direct printing on nylon fabric. For dyeing cotton (or sticky) fabric, can be with direct dye in the neutral dye bath with the bath dyeing, can also be dyed cotton (or sticky) fabric, can also be used for leather dyeing. The synthesis of the product is based on 2-amino-4-chlorophenol and 1-(m-sulfonylaminophenyl)-3-methyl -5-pyrazolone as raw materials, by diazotization, coupling, complexation preparation. |
| preparation | 1, 2-amino -4-chlorophenol diazotization three bottles were added with 30% ml of water and hydrochloric acid 30. 4G, add 14. 4 g of 2-amino-4-chlorophenol was dissolved after stirring. With ice-cooling to 5 ℃, 30% sodium nitrite solution (7. 4 G sodium nitrite) was added dropwise, and the mixture was kept and stirred for 1 h, and the end point was measured with starch potassium iodide test paper. 2, 2-amino -4-chlorophenol diazonium salt and 1-(m-sulfonylaminophenyl)-3-methyl -5-pyrazolone coupling in three bottles of 300 ml of water, Under stirring, 25.8g of soda ash and 26.6g of 1-(m-sulfonylaminophenyl)-3-methyl-5-pyrazolone were added, and the mixture was heated to 30-40 °c and dissolved by stirring. Then the temperature was lowered to 10 ℃. The diazonium salt solution of 2-amino-4-chlorophenol was added uniformly within 40 min, and the reaction was continued for 2 h while keeping the pH value between 9 and 10 after adding. The reaction solution was to be complexed. Preparation of sodium salt of chromium salicylate 200 ml of water and 25. 38 g of 98% chromium alum were added into three bottles, stirred and heated to 80 ° C. To be completely dissolved, and filtered to remove impurities. 19. 9 g of 98% salicylic acid was added to the filtrate, Reflux was heated and maintained for 1 h. After cooling to 80 ℃, slowly add 40% sodium hydroxide solution to adjust the pH value of 7. 5, and then stir for 10 min. 4. Complexation of azo compound in the above solution of sodium chromium salicylate, the diazonium salt of 2-amino-4-chlorophenol and 1-(m-sulfonylaminophenyl) were added in a small stream. -3-methyl -5-pyrazolone made of coupling liquid, slowly heated to reflux and in the process of temperature at any time to adjust the pH value 7. 0~7. 5, maintain reflux 6 h. After the end of the reaction, with 5% hydrochloric acid to adjust to pH 6. 5, then cooled to 60 ℃, plus 11 g sodium chloride salting out, Finally, the temperature was cooled to 30 ° C., the salting out condition was detected, filtered and dried. |
| Use | neutral red 2GL is the basic dye for medium and dark red dyes, mainly used for dyeing coarse and worsted wool fabrics and wool tops, the color light can be adjusted with other neutral dyes or brightening dyes. Also used for dyeing silk, nylon, Vinylon and wool, silk, nylon fabric printing directly. When used to dye wool cotton (or viscose) fabrics, it can be dyed with direct dye in the same bath in the neutral dye bath. Can also be dyed cotton (or viscose) fabric. |
| production method | with 2-amino-4-chlorophenol, 1-(m-sulfonylaminophenyl)-3-methyl -5-pyrazolone as raw material, first 2-amino -4-chlorophenol diazotization, coupled with the latter, then complexed with sodium chromium formate, filtered and dried to get the finished product.. |