Method for purifying N-methyl pyrrolidone and gamma-butyrolactone

Abstract

The invention discloses a method for purifying N-methyl pyrrolidone and gamma-butyrolactone, which comprises the following steps of: making a reagent to be purified pass through a polystyrene-divinylbenzene type nonpolar macroporous resin column, filtering by using a charged cellulose membrane, and performing rough filtration and fine filtration on filtrate in turn by using polytetrafluoroethylene filters in different dimensions. The method has the advantages of simple process, easily controlled conditions, low energy consumption, no rigorous requirement on power equipment, no need of special temperature control conditions and effective production under conventional temperature, and is used for recovering and purifying the N-methyl pyrrolidone and the gamma-butyrolactone, and the purity of the obtained reagent can reach an electron level; meanwhile, materials such as the macroporous resin can be used as fuel to be reutilized, and are light in environmental pollution; and the process has a larger application space and good market prospect.

Description

technical field [0001] The invention relates to a method for purifying N-methylpyrrolidone and gamma-butyrolactone. Background technique [0002] With the rapid development of science and technology, especially the rapid development of the electronics industry, more and higher-purity electronic chemicals are needed. These high-purity electronic chemicals are mainly divided into two categories: organic and inorganic. High-purity chemicals are relatively common, and the technology is gradually becoming mature. However, almost all organic solvent-based high-purity chemicals rely on imports, and the core technology is monopolized by foreign countries, making it a major bottleneck restricting the development of my country's electronics industry. According to the requirements put forward by the International Semiconductor Industry Association, high-purity electronic chemicals have strict requirements on purity, moisture, ion content, particle level and pH, among which ion content a...

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Problems solved by technology

At present, the electronic grade NMP and GBL products produced in China require the content of metal ions to be less than 10ppb, and NMP is an excellent organic solvent, which has a strong solubility for many substances in nature, and the temperature of the rectification process is relatively high. The rectification tower made of polytetrafluoroethylene cannot withstand high temperature, and the heat transfer effect of the equipment is poor, so the temperature is not easy to control, and the equipment investment is high; if the equipment made of stainless steel is bound to introduce a small amount of metal impurities, and both exist due to The problem of high content of solid dust particles brought in by raw material factors

[0004] At present, domestic NMP is mainly divided into four grades: industrial grade, aramid fiber grade, electronic grade and reagent grade. Among them, electronic grade and reagent grade require product purity to reach 99.9%, moisture content <300ppm, and various metal ion contents less than 10ppb. The anion content is less than 0.5ppm. In addition, according to the standards established by the International Semiconductor Association, the particle level is less than 25 / L, and the pH is between 7-9. The purity, moisture content, anion content and pH of the product through rectification with stainless steel The value can basically meet the requirements, but the content of metal ions and the number of particles cannot meet the requirements, which has become a bottleneck problem restricting the development of high-purity organic electronic chemicals

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