Production and refining method of alpha, alpha'-dinitroanthraquinone

Abstract

The invention relates to a refining method of alpha, alpha'-dinitroanthraquinone. The method comprises the following steps: carrying out a dinitration reaction on anthraquinone under the effect of a low ratio of sulfuric acid and a high ratio of nitric acid at a low temperature, and distilling concentrated nitric acid at 60-75DEG C in a vacuum condition after completing dinitration reaction the according to a method disclosed in a patent of CN101423477A; slowly cooling materials to a temperature of below 35DEG C when the nitric acid distillation is finished, keeping the temperature for 1h, and precipitating alpha, alpha'-dinitroanthraquinone through crystallization; and filtering a mixture, beating a filter cake in water, refiltering, washing to the pH to above 5, and drying to obtain high quality alpha, alpha'-dinitroanthraquinone. According to the method of the present invention, the distillation amount of concentrated nitric acid can be conveniently controlled to adjust the concentration of nitric acid in a system, so alpha, alpha'-dinitroanthraquinone can satisfy quality requirements; crystallization is carried out below 35DEG C, so generated coarse crystals of alpha, alpha'-dinitroanthraquinone are easy to filter; and the concentration of nitric acid is low in filtering, so operating environment is substantially improved.

Description

Technical field

[0001] The invention relates to a clean and refining method of α, α'-dinitroanthraquinone, a dye intermediate. Background technique

[0002] α, α'-Dinitroanthraquinone is a mixture of 1,5-dinitroanthraquinone and 1,8-dinitroanthraquinone. It is mainly used to produce large tonnage anthraquinone-type disperse dye CI Disperse Blue 56 ( Trade name: Disperse Blue E-4R, Disperse Blue 2BLN). C.I. Disperse Blue 56 color bright blue, good light fastness, medium sublimation fastness, good dye depth, level dyeing and covering power, good color matching compatibility. Therefore, it is widely used in the dyeing of polyester and its blended fibers and the dyeing of other hydrophobic fibers. At present, it is basically produced in my country, and the annual output of commercial dyes is nearly 30,000 tons.

[0003] Predecessors have studied various anthraquinone dinitrification methods. But no matter which method, the products of anthraquinone dinitration are composed of 1,...

Examples

Embodiment 1

[0028] Put 100 parts of 98.5% anthraquinone into 430 parts of 98% nitric acid, stir and cool to 5℃, keep at 5~10℃, add 68 parts of 104.5% sulfuric acid dropwise, after 4 hours of dripping, continue to keep the temperature at 5~10℃ for reaction 2 hours, then keep the temperature at 40~45℃ and react for 2 hours; distill 240 parts of concentrated nitric acid (100%) at 60~75℃ under reduced pressure; after the nitric acid has been evaporated, slowly cool the material to 35℃ in 1~2 hours, Keep it at 35°C for 1 hour, filter, filter out the mother liquor acid in the filter cake as much as possible, and then distill the mother liquor acid under reduced pressure below 140°C to recover concentrated nitric acid.

[0029] The filter cake was slurried with water, filtered, the filter cake was washed with water to a pH above 5, and dried to obtain 119.1 parts of α, α'-dinitroanthraquinone, with a mass fraction of 95.22%, and the pure yield of p-anthraquinone was 80.0%.

[0030] The refined α, α'...

Embodiment 2

[0038] Put 100 parts of 98.5% anthraquinone into 650 parts of 98% nitric acid, stir and cool to -10℃, keep it at -10~-5℃, add 80 parts of 104.5% sulfuric acid dropwise, after 4 hours of dropwise addition, continue at -10 Incubate at ~-5°C for 2 hours, then heat to 20~25°C for 2 hours, then at 40~45°C for 2 hours; reduce pressure, distill 375 parts of concentrated nitric acid (100%) at 60~75°C ; The following operation is the same as in implementation 1, and 123.7 parts of α, α'-dinitroanthraquinone are obtained, with a mass fraction of 95.02%, and the pure yield of anthraquinone is 82.9%.

[0039] The refined α, α'-dinitroanthraquinone analysis data are as follows:

[0040] 1,8-Dinitroanthraquinone 43.47%

[0041] 1,5-Dinitroanthraquinone 50.65%

[0042] 1-Nitroanthraquinone 0.22%

[0043] 1,7-Dinitroanthraquinone 3.24%

[0044] 1,6-Dinitroanthraquinone 2.2%

[0045] 2-Nitroanthraquinone 0.06%.

Embodiment 3

[0047] Combine 490 parts of 98.5% nitric acid and 50 parts of 104.5% sulfuric acid, stir and mix and cool to -15°C, keep it at -15~-10°C, gradually add 100 parts of 98.5% anthraquinone to the mixed acid, and finish in 4 hours. Incubate at -15~-10℃ for 2 hours, then heat to 15~20℃ for 2 hours, then heat to 40~45℃ for 2 hours; reduce pressure, distill concentrated nitric acid (100%) at 60~75℃ ) 190 parts; the following operation is the same as that of 1 to obtain 117.8 parts of α, α'-dinitroanthraquinone, the mass fraction is 96.91%, and the pure yield of anthraquinone is 80.5%,

[0048] The refined α, α'-dinitroanthraquinone analysis data are as follows:

[0049] 1,8-Dinitroanthraquinone 42.15%

[0050] 1,5-Dinitroanthraquinone 54.76%

[0051] 1-Nitroanthraquinone 0.036%

[0052] 1,7-Dinitroanthraquinone 1.35%

[0053] 1,6-Dinitroanthraquinone 1.53%

[0054] 2-Nitroanthraquinone 0.049%.

Technical field

[0001] The invention relates to a clean and refining method of α, α'-dinitroanthraquinone, a dye intermediate. Background technique

[0002] α, α'-Dinitroanthraquinone is a mixture of 1,5-dinitroanthraquinone and 1,8-dinitroanthraquinone. It is mainly used to produce large tonnage anthraquinone-type disperse dye CI Disperse Blue 56 ( Trade name: Disperse Blue E-4R, Disperse Blue 2BLN). C.I. Disperse Blue 56 color bright blue, good light fastness, medium sublimation fastness, good dye depth, level dyeing and covering power, good color matching compatibility. Therefore, it is widely used in the dyeing of polyester and its blended fibers and the dyeing of other hydrophobic fibers. At present, it is basically produced in my country, and the annual output of commercial dyes is nearly 30,000 tons.

[0003] Predecessors have studied various anthraquinone dinitrification methods. But no matter which method, the products of anthraquinone dinitration are composed of 1,...

Examples

Embodiment 1

[0028] Put 100 parts of 98.5% anthraquinone into 430 parts of 98% nitric acid, stir and cool to 5℃, keep at 5~10℃, add 68 parts of 104.5% sulfuric acid dropwise, after 4 hours of dripping, continue to keep the temperature at 5~10℃ for reaction 2 hours, then keep the temperature at 40~45℃ and react for 2 hours; distill 240 parts of concentrated nitric acid (100%) at 60~75℃ under reduced pressure; after the nitric acid has been evaporated, slowly cool the material to 35℃ in 1~2 hours, Keep it at 35°C for 1 hour, filter, filter out the mother liquor acid in the filter cake as much as possible, and then distill the mother liquor acid under reduced pressure below 140°C to recover concentrated nitric acid.

[0029] The filter cake was slurried with water, filtered, the filter cake was washed with water to a pH above 5, and dried to obtain 119.1 parts of α, α'-dinitroanthraquinone, with a mass fraction of 95.22%, and the pure yield of p-anthraquinone was 80.0%.

[0030] The refined α, α'...

Embodiment 2

[0038] Put 100 parts of 98.5% anthraquinone into 650 parts of 98% nitric acid, stir and cool to -10℃, keep it at -10~-5℃, add 80 parts of 104.5% sulfuric acid dropwise, after 4 hours of dropwise addition, continue at -10 Incubate at ~-5°C for 2 hours, then heat to 20~25°C for 2 hours, then at 40~45°C for 2 hours; reduce pressure, distill 375 parts of concentrated nitric acid (100%) at 60~75°C ; The following operation is the same as in implementation 1, and 123.7 parts of α, α'-dinitroanthraquinone are obtained, with a mass fraction of 95.02%, and the pure yield of anthraquinone is 82.9%.

[0039] The refined α, α'-dinitroanthraquinone analysis data are as follows:

[0040] 1,8-Dinitroanthraquinone 43.47%

[0041] 1,5-Dinitroanthraquinone 50.65%

[0042] 1-Nitroanthraquinone 0.22%

[0043] 1,7-Dinitroanthraquinone 3.24%

[0044] 1,6-Dinitroanthraquinone 2.2%

[0045] 2-Nitroanthraquinone 0.06%.

Embodiment 3

[0047] Combine 490 parts of 98.5% nitric acid and 50 parts of 104.5% sulfuric acid, stir and mix and cool to -15°C, keep it at -15~-10°C, gradually add 100 parts of 98.5% anthraquinone to the mixed acid, and finish in 4 hours. Incubate at -15~-10℃ for 2 hours, then heat to 15~20℃ for 2 hours, then heat to 40~45℃ for 2 hours; reduce pressure, distill concentrated nitric acid (100%) at 60~75℃ ) 190 parts; the following operation is the same as that of 1 to obtain 117.8 parts of α, α'-dinitroanthraquinone, the mass fraction is 96.91%, and the pure yield of anthraquinone is 80.5%,

[0048] The refined α, α'-dinitroanthraquinone analysis data are as follows:

[0049] 1,8-Dinitroanthraquinone 42.15%

[0050] 1,5-Dinitroanthraquinone 54.76%

[0051] 1-Nitroanthraquinone 0.036%

[0052] 1,7-Dinitroanthraquinone 1.35%

[0053] 1,6-Dinitroanthraquinone 1.53%

[0054] 2-Nitroanthraquinone 0.049%.