Method for producing modified disperse red 60

Abstract

This invention relates to an improved method for producing disperse red 60. The method comprises: bromizing and hydrolyzing 1-aminoanthraquinone in sulfuric acid medium to obtain 1-amino-2-bromo-4-hydroxylanthraquinone wet filter cake, condensing in the presence of phenol medium and acid-attaching agent, cooling to 95-100 deg.C at the condensation end-point, adding water, dropping alkali solution, cooling to 50-52 deg.C, filtering, washing, and drying to obtain 1-amino-2-bromo-4-hydroxylanthraquinone (disperse red 60). The method directly utilizes disperse red 60 wet filter cake to avoid the drying procedure, thus simplifying the operation, lowering the equipment investment, improving the operation conditions, and reducing the labor intensity. Besides, the method also increases product yield and quality, as well as reduces phenol amount.

Description

technical field [0001] The invention relates to an improved production method of disperse red 60. More specifically, it is the improvement of the condensation process in the existing production method of disperse red 60. Background technique [0002] The chemical name of Disperse Red 60 is 1-amino-2-phenoxy-4-hydroxyanthraquinone. The existing production method uses 1-aminoanthraquinone as a raw material to react with bromine in a sulfuric acid medium to obtain 2,4-dibromo-1-aminoanthraquinone, and the reaction product is directly heated and hydrolyzed in sulfuric acid without separation to obtain 1-Amino-2-bromo-4-hydroxyanthraquinone, after isolation, filtration, washing and drying, the product is condensed in a phenol medium. After reaching the end point of condensation, the temperature is lowered to 95-100°C, and water is added at this temperature , then dropwise add liquid caustic soda, and finally lower the temperature to 50-52°C, filter, wash, and dry to obtain 1-am...

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Problems solved by technology

However, since water will be produced during the condensation reaction in the phenol medium, a small amount of water will also be brought into the raw materials, which is not conducive to the condensation reaction, resulting in a longer condensation reaction time, and the usual condensation temperature is 150 ~ 165 ° C, 1-Amino-2-bromo-4-hydroxyanthraquinone and phenol will be coked at this temperature for a long time, resulting in high tar content in the final product, large fluctuations in product quality, and the single-step condensation yield is only in Between 85% and 88%, the production cost is relatively high; Yangzhou University has improved the post-treatment process of condensation, that is, after the condensation reaction is completed, methanol is added for isolation, and the product quality has improved, but the condensation reaction itself has not been improved. , the yield is still low, and because the boiling point of methanol is too low and it is a Class A flammable and explosive chemical, the loss in the filtration and washing process is huge. Large potential safety hazards in production; Mitsui Toya of Japan uses ethylene glycol monomethyl ether instead of methanol for separation, which solves the safety and operating environment problems of methanol, but the loss of ethylene glycol monomethyl ether is still high, and ethylene glycol The price of monomethyl ether is much higher than that of methanol, so its cost problem is more prominent; in the condensation process involved in the above-mentioned methods, there is a common shortcoming, that is, the used 1-amino-2-bromo-4-hydroxyanthraquinone Both need to be dried. Since the intermediate is obtained by segregating in sulfuric acid medium, the trace acid in the filter cake cannot be washed away, resulting in serious corrosion of the drying equipment. In addition, the dust of the dry product also seriously affects the operating environment, and the labor intensity of the workers is also great. ; Wuxi Dyestuff Factory once improved the condensation process, adopting in the presence of a phase transfer catalyst in an aqueous medium, phenol and 1-amino-2-bromo-4-hydroxyl anthraquinone were condensed to obtain the product, although this method solved 1 - The drying problem of amino-2-bromo-4-hydroxyanthraquinone, but because of the high price of the phase transfer catalyst used, the consumption is huge and cannot be recovered, which not only causes environmental pollution, but also has high cost and no actual industrial value

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