Long-chain mixed dicarboxylic acid purification method

Abstract

The present invention relates to a long-chain mixed dicarboxylic acid extraction method, which comprises: (1) adding a mixed dicarboxylic acid solid to water, heating, adding an alkali to adjust the pH value, dissolving, cooling, precipitating, and separating to obtain a solid I; (2) pouring the solid I to water, heating to increase the temperature, and after dissolving the solid I, adding an oxidizing agent to oxidize so as to improve the solution color and reduce the high carbon number dicarboxylic acid content in the solution; and (3) adding an acid to the obtained solution to adjust the pH value so as to precipitate the mixed dicarboxylic acid, separating the solid, and drying to obtain the long-chain mixed dicarboxylic acid finished product. According to the present invention, the second precipitation and the oxidizing process are combined in the water phase to obtain the high quality dicarboxylic acid finished product, wherein the dicarboxylic acid finished product has characteristics of white color, good quality, and low high-carbon-number dicarboxylic acid (dicarboxylic acid having more than or equal to 16 carbon number) content, and is especially suitable for the anti-rust field; and with the extraction process, the by-product discharge problem during the long-chain dicarboxylic acid production can be simply and effectively solved, such that the environment is protected and the enterprise incomes are increased.

Description

technical field

[0001] The invention relates to a method for treating mixed long-chain dibasic acids, in particular to a purification method for decolorizing and oxidizing mixed long-chain dibasic acids. Background technique

[0002] Long chain dicarboxylic acids (Long chain dicarboxylic acids) refer to aliphatic dicarboxylic acids (DCn for short) containing more than 10 carbon atoms in the carbon chain, including saturated and unsaturated dicarboxylic acids. The fine chemical products used in the chemical industry are synthetic high-grade spices, high-performance nylon engineering plastics, high-grade nylon hot-melt adhesives, high-temperature dielectrics, high-grade paints and coatings, high-grade lubricating oils, cold-resistant plasticizers, resins, medicines and pesticides, etc. important basic raw materials. Due to the broad development potential of the downstream products of long-chain dibasic acids, the demand for long-chain dibasic acids at home and abroad will con...

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