Method for reducing content of quinine in polyphenyl ether product and recovering biphenyl diquinone

Abstract

The invention relates to a method for reducing the content of quinine in a polyphenyl ether product and recovering biphenyl diquinone, comprising the following steps of: (1) rising the temperature of reaction products from preparation of polyphenyl ether by a precipitation method to be 55-65 DEG C, balancing and obtaining polyphenyl ether mixed liquid; (2) filtering the polyphenyl ether mixed liquid, washing for four times, drying filter cakes and obtaining the polyphenyl ether; (3) taking the filtrate in the previous two times, filtering, washing the filter cakes with acetone and pure water in sequence, drying and obtaining a biphenyl diquinone crude product; and (4) carrying out precipitation, filtering and drying on the biphenyl diquinone crude product and obtaining the biphenyl diquinone. In the method, the operation process is simple, the purity of the recovered biphenyl diquinone is high, the content of the quinine in the polyphenyl ether product can also be reduced, and the industrial application prospect is larger.

Description

technical field [0001] The invention relates to the field of polymer chemistry, in particular to a method for reducing the quinone content in polyphenylene ether products and recovering diphenyldiquinone. Background technique [0002] Generally, there are two methods for the production of polyphenylene ether: precipitation method and solution method, no matter which production method is always accompanied by the by-product biphenyl diphenylene ether in the process of oxidative coupling of 2,6-dimethylphenol to generate polyphenylene ether. Production of quinones (3,3,5,5-tetramethyl-4,4-biphenyldiquinone). U.S. Patent US4234706 provides a method for reducing the quinone content in polyphenylene ether by redistribution reaction between diphenoquinone and polyphenylene ether at high temperature after the reaction is terminated, which is more suitable for solution method, but not suitable for precipitation method For the precipitation method, since the polyphenylene ether has ...

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Problems solved by technology

U.S. Patent US4234706 provides a method for reducing the quinone content in polyphenylene ether by redistribution reaction between diphenoquinone and polyphenylene ether at high temperature after the reaction is terminated, which is more suitable for solution method, but not suitable for precipitation method , for the precipitation method, since the polyphenylene ether has been precipitated as particles, it is difficult to redistribute the reaction with diphenyldiquinone even at high temperature

U.S. Patent No. 4,060,514 provides a method for contacting polyphenylene ether with dithionate or thiosulfuric acid reducing agent in the presence of a phase transfer agent to remove diphenoquinone, although this method is suitable for precipitation production. But the color of polyphenylene ether obtained by this method is not ideal

U.S. Patent No. 3,637,593A provides a method for treating a mixture of polyphenylene ether and diphenoquinone with hydrogen halide to change diphenoquinone into a halogenated diphenoquinone, but this method may make the polyphenylene ether residual Halogen elements, resulting in poor oxidation stability of polyphenylene ether

Chinese patent CN101717501A provides a method to carry out the oxidative coupling reaction of monomer phenols until the degree of polymerization of polyphenylene ether monomer is 50-95%. The polymerization method of quinone, although this method can effectively reduce the content of diphenoquinone in polyphenylene ether resin, but the preparation process is relatively complicated

At present, in the process of producing polyphenylene ether by precipitation method, diphenyldiquinone is usually discharged along with oligomers, and has not been effectively recovered and utilized, resulting in a certain amount of waste

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