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Purifying method for electronic-grade N,N-dimethylformamide

A dimethylformamide, electronic-grade technology, applied in the field of N, can solve problems such as not being seen, complex resin pretreatment and regeneration process, and increased post-processing burden

Inactive Publication Date: 2011-03-30
TIANJIN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0011] (1) The pretreatment and regeneration process of the resin is complicated;
[0012] (2) need to replace the water in the resin bed with DMF solution in the pretreatment and regeneration process, so just form the DMF aqueous solution, increase the burden of aftertreatment;
[0013] (3) There will be a small amount of water coming out of the resin during the purification process of DMF, which increases the water content in the DMF product
[0014] At the same time, so far, CEDI technology is used in the production of high-purity water or in aqueous systems. There is no patent to use CEDI technology in the purification process of N,N-dimethylformamide in pure organic systems.

Method used

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  • Purifying method for electronic-grade N,N-dimethylformamide

Examples

Experimental program
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Effect test

Embodiment 1

[0028] Such as figure 1 As shown, the industrial-grade DMF product is sent to the vacuum rectification tower 102 by the pump 101. The rectification tower is made of stainless steel SUS316L. Boiling point dimethylamine, formic acid and water enter the circulating water of the water circulation vacuum system, the circulating water is regularly updated, the non-condensable gas is vented, and the products from the bottom of the tower are input into the deionization chamber 209 of the electrodeionization device 104 by the pump 103, and the deionization chamber is filled There are commercial brand D280 Styrene-DVB macroporous strongly basic styrene-based anion exchange resin and commercial brand D072 StyreneDVB macroporous strongly acidic styrene-based cation exchange resin, the ratio of anion and cation resin is 1.5:1 (v / v), The membrane 205 is a homogeneous cation exchange membrane JCM-15, and the anion membrane 206 is a homogeneous anion exchange membrane JAM-15. The voltage corr...

Embodiment 2

[0030] Process conditions and equipment are the same as in Example 1, except that the operating pressure of the vacuum rectification tower is 8.7kPa, and the operating temperature is 80°C. The conductivity of DMF treated by this condition and equipment is reduced from 0.165 μs / cm to 0.008 μs / cm, the pH value is 7.03, the physical properties of the product and the content of metal ions are listed in Table 1, the content of each metal ion is less than 10ppb, and the product meets the quality indicators of electronic chemicals.

Embodiment 3

[0032] Process conditions and equipment are the same as in Example 1, except that the operating pressure of the vacuum rectification tower is 27.2kPa, and the operating temperature is 110°C. The conductivity of DMF treated by this condition and equipment is reduced from 0.165 μs / cm to 0.060 μs / cm, the pH value is 7.22, the physical properties of the product and the content of metal ions are listed in Table 1.

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Abstract

The invention discloses a purifying method for electronic-grade N,N-dimethylformamide, which is characterized in that the industrial-grade dimethylformamide (DMF) is decompressed and rectified; the material of a decompressing and rectifying tower is stainless steel; the operating pressure is between 8.7 and 27.2 kPa; the operating temperature is from 80 to 110 DEG C; the formic acid with low boiling point, the water and the dimethylamine impurities in the DMF are eliminated from the top of the tower; the DMF from the bottom of the rectifying tower enters a continuous electric deionizing device; and the metal ions, the formic acid, the organic amine and the salt impurities generated by the formic acid and the organic amine in the N,N-dimethylformamide are eliminated by utilizing ion exchange resins and the coupling technique of electrodialysis under an electric field. The invention provides a producing process with the advantages of good purification effect and low energy consumption, and the continuous production purity reaches the purity requirements of electronic chemicals. Thus, the content of the impurity metal ions in the DMF product is lower than 10ppb, the content of the dimethylamine, the formic acid and the electrolyte impurity capable of being ionized is lower than 0.5ppm, the electric conductance of the product DMF is less than 0.010 mu second / cm, and the obtained DMF product can be used for the electronic industries of copper-clad plates and the like.

Description

technical field [0001] The invention relates to the technical field of purification, in particular to a method for purifying electronic-grade N,N-dimethylformamide. Background technique [0002] N, N-dimethylformamide, its English name is N, N-dimethyl formamide (abbreviated as DMF), structural formula: HCON (CH 3 ) 2 , it is a colorless, transparent liquid with little toxicity and a slight ammonia smell. DMF has strong polarity and is a good organic solvent. It is mainly used in the industries of polyurethane, acrylic, electronics, pharmaceutical intermediates, and pesticides. In the electronics industry, it is used as a solvent in the production process of copper-clad laminates, a quenching agent for tin-plated parts, a cleaning agent for circuit boards, and an electrolyte for electrochemical synthesis. [0003] N, the production method of N-dimethylformamide has multiple, commercial majority is carbon monoxide and dimethylamine one-step synthetic method at present, and...

Claims

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Application Information

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IPC IPC(8): C07C233/03C07C231/24
Inventor 杨长生马升勇刘占光
Owner TIANJIN UNIV
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