Membrane process preparation method of electronic-grade 1,3-propanesultone

Abstract

The invention belongs to the technical field of production of electronic materials, and concretely relates to a membrane process preparation method of electronic-grade 1,3-propanesultone. The method comprises the following steps: standing 1,3-propanesultone in a reactor provided with a molecular sieve, carrying out reduced pressure distillation, removing impurities through a nanofiltration device, concentrating the obtained 1,3-propanesultone through a disc tube type reverse osmosis device, and allowing the obtained 1,3-propanesultone to pass through the glass column of the molecular sieve. The acid value of the prepared 1,3-propanesultone is stably controlled in a required range, all indexes of the prepared 1,3-propanesultone are qualified, the quality of the prepared 1,3-propanesultone is stable, the water content and the sodium content of the prepared 1,3-propanesultone are further reduced and are better than electronic grade standards, and the indexes of the prepared 1,3-propanesultone exceed those of most existing electronic-grade 1,3-propanesultone.

Description

technical field [0001] The invention belongs to the technical field of electronic material preparation, and in particular relates to a membrane method for preparing electronic grade 1,3-propane sultone. Background technique [0002] 1.3-Propane sultone (hereinafter referred to as "1.3-PS") is an important intermediate. 1,3-Propane sultone is a white crystal at room temperature with a melting point of 30-33°C. It is widely used in surface treatment, electronic plating, biochemistry, emulsion polymerization, wastewater treatment, photosensitive materials, lithium batteries, surfactants, etc. [0003] High-end lithium battery electrolytes have higher and higher requirements for the quality of 1,3-propane sultone, especially for acid value (less than 50ppm) and moisture (less than 50ppm). However, domestic 1,3-propane Quality of sultone The quality of products varies from good to bad, showing a situation of small output and unstable quality, which makes it difficult to meet the...

AI Technical Summary

Problems solved by technology

[0004] 1) Patent CN200910068035.8 is refined by recrystallization method. Propane sultone is refined at a certain temperature through a specific crystallization vessel. This method does not analyze the influence of acid value and moisture of propane sultone;

[0005] 2) Patent CN201210015838.9 adopts the method of water washing and organic matter extraction to remove the free acid in propane sultone and re-distill the method to prepare electronic grade sultone. However, this method will introduce more free water and increase moisture difficulty of control;

[0006] 3) Patent CN201410147908.5 adopts the addition of strong alkaline substances such as calcium oxide, sodium methoxide and water in a certain proportion, and removes the moisture and acid value of propane sultone by high temperature and reduced pressure distillation. The heat sensitivity of propane sultone, after adding strong alkaline substances, increases the risk of 1,3-propane sultone decomposition during the distillation process, resulting in the possibility of more free acids and the difficulty of production control

[0008] For the control of 1.3-PS moisture and acid value, the traditional preparation of 1.3-PS is through rectification control to meet the requirements of electronic grade 1.3-PS products, but it cannot be well and stably controlled, and its quality is unstable ;

[0009] Rectification can obviously increase the content of the product, but in most cases, the water can only be stably controlled at 300ppm, and the acid value can only be stably controlled at 500ppm. Electronic grade 1.3-PS products produced by this method Quality is often substandard;

[0010] In addition, simple dehydration of 1,3-PS with molecular sieve can solve the problem of 1,3-PS moisture, but the use amount is large, the cost is high, and other impurities will be introduced, especially Na+, which seriously exceeds the standard, making the product The quality of the