Continuous washing method for product in polyphenylene sulfide production

Abstract

The invention discloses a method for continuously washing products generated in the process of production of polyphenylene sulfide, which can improve the production efficiency, reduce the energy consumption and provide a stable material flow for subsequent technologies. The method comprises the following steps: firstly, a mixture required to be washed after polymerization is sent into a horizontal helical discharging sedimentation centrifuge for filtration, and separated solid substances, namely coarse products of polyphenylene sulfide resin, are directly sent into a disposable washing kettle; secondly, the coarse products of the polyphenylene sulfide resin are mixed with washing water in the disposable washing kettle, and fully stirred, and enters into a second horizontal helical discharging sedimentation centrifuge for filtration and separation, and separated solid substances are sent into a second washing kettle for secondary washing; and thirdly, washing and centrifugal separation are continuously performed until the purity of the polyphenylene sulfide resin meets the standards, wherein washing and centrifugal separation each time is a washing period.

Description

Technical field [0001] The invention relates to a production process for producing polyphenylene sulfide by using p-dichlorobenzene and sodium sulfide as main raw materials, and in particular to a method for washing products in the production process. Background technique [0002] Polyphenylene sulfide (PPS for short) is a new type of high-performance thermoplastic resin with excellent thermal stability, chemical stability, corrosion resistance and electrical properties, etc., used in aerospace, electronic and electrical, petrochemical, machinery manufacturing, food , Light industry, etc. have a wide range of applications. The synthesis of PPS has been studied for many years, and a variety of synthetic methods have been developed. However, there is only one method for realizing large-scale industrial production: using p-dichlorobenzene and sodium sulfide as the main raw materials, and alkali metal compounds as catalysts. Using N-methyl-2-pyrrolidone (abbreviated as NMP) as a solv...

AI Technical Summary

Problems solved by technology

This method has less equipment and is relatively simple to operate, but the production efficiency of intermittent operation is low, the material is always in contact with the external environment during the operation, and multiple washing operations are all completed in the same device, which is likely to cause contamination of the material and the operating environment of the operator. poor

In addition, intermittent washing makes the discharge uncontinuous, resulting in the subsequent solvent recovery and other processes also adopting intermittent operations, the operation process fluctuates greatly, the production capacity is limited, and the washing and filtering effects are difficult to meet the output requirements and product quality in large-scale industrial production. index