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Method for preparing electronic-grade N, N-dimethylformamide by ion exchange resin method

A technology of dimethylformamide and ion exchange resin, which is applied in the field of purification technology, can solve the problems of affecting, affecting the adjustment of polymerization reaction speed, and not considering the problem of metal ion removal.

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

[0008] So far, the use of ion exchange resins to purify DMF patents involves the treatment of DMF solvent recovered from the spinning process of acrylonitrile polymerization, and the removal of impurities is formic acid, dimethylamine and their generated DMF is used in the electronics industry and polyurethane advanced slurry industry. In addition to the removal of organic impurities such as formic acid and dimethylamine, the metal ion content is an important quality indicator. In the electronics industry such as copper clad laminates, metal ions The content affects the electrical insulation of copper clad laminates. In the polyurethane advanced slurry industry, alkali metal ions have a catalytic effect, which affects the adjustment of the polymerization reaction speed. So far, the removal of metal ions in DMF has not been considered in the patent

Method used

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  • Method for preparing electronic-grade N, N-dimethylformamide by ion exchange resin method

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Experimental program
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Embodiment 1

[0024] Such as figure 1As shown, the DMF is purified in the form of multiple beds. The ion exchange column IE-1 is a cation exchange column. Column IE-2 is an anion exchange column, and the column is equipped with a commercial brand of 201×7 Styrene DVB strong basic styrene-based anion exchange resin. The material of the resin column is glass, and its specification is Φ30×1000mm. The height of the exchange resin is 500mm. The resin in the ion exchange column is pretreated before use. For the cation exchange resin, first wash the resin with deionized water, then drain the water in the resin column, and soak the resin with DMF solution 8 hours, then replace the DMF in the resin with deionized water, rinse until the DMF weight percent concentration at the outlet of the exchange column is 0.3%, and then use 4% NH 4 OH is rinsed at 10mL / min, and the molar number of alkali used is three times the exchange capacity of the resin, followed by rinsing with deionized water to neutrality...

Embodiment 2

[0028] The process flow and equipment are the same as in Example 1, except that the cation exchange column IE-1 is equipped with a macroporous strongly acidic cation exchange resin of D072 Styrene DVB, and the anion exchange column IE-2 is equipped with a brand of Styrene DVB D301T macroporous weakly basic anion exchange resin, the anion and cation exchange resins are pretreated according to the pretreatment process and conditions of embodiment 1, and then according to the technical process figure 1 The process of industrial grade DMF is purified, the conductivity of DMF treated by this process and equipment is reduced from 0.165 μs / cm to 0.150 μs / cm, and the pH value of 20% (v / v) DMF aqueous solution is changed from 7.3 It is 7.10, and the content of each metal ion measured is less than 10ppb. Other properties are shown in Table 1.

Embodiment 3

[0030] Such as figure 2 As shown, DMF is purified in the form of a mixed bed. The ion exchange column IE-3 is a mixed bed ion exchange column. The material of the resin column is glass, and its specification is Φ30×1000mm. A mixture of DVB macroporous strongly acidic styrene-based anion exchange resin and Styrene DVB D301T macroporous weakly basic styrene-based cation exchange resin. First, pretreat the anion exchange resin. The pretreatment method is to wash the resin with water first. , then soak the resin with N, N-dimethylformamide solution for 6 hours, then replace N, N-dimethylformamide with deionized water, and rinse until the exchange column outlet N, N-dimethylformamide weight The percentage concentration is 0.4%, and then rinse with HCl with a concentration of 4.0% at a flow rate of 20mL / min. The molar number of acid used is twice the exchange capacity of the resin, and then rinse with deionized water until neutral, and then use The DMF solution replaces the water ...

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Abstract

The invention discloses a method for preparing electronic-grade N, N-dimethylformamide by an ion exchange resin method, which comprises the steps of: pumping industrial-grade N, N-dimethylformamide into a heat exchanger; reducing the temperature of raw material to room temperature of 40 DEG C; entering an ion exchange unit; removing metal ions, formic acid, dimethylamine and salt impurities generated by the formic acid and the dimethylamine from the N, N-dimethylformamide by an ion exchange method; and filtering broken resin and granular impurities in the N, N-dimethylformamide by a filtering unit to obtain the electronic-grade N, N-dimethylformamide. In the prepared electronic-grade N, N-dimethylformamide DMF, the content of each metal ion is less than 10 ppb; the content of methylamine and the content of the formic acid are reduced to be less than 1 ppm; the pH value of DMF is 7.0 approximately; the conductance of pure DMF is less than 0.010 microsecond / cm; a purified DMF is used as a high-end product for electronics industry of manufacturing copper-clad plates and high-grade pulp industry of polyurethane synthetic leather.

Description

technical field [0001] The present invention relates to a method for preparing electronic grade N,N-dimethylformamide products by removing impurities such as methylamine, formic acid and metal ions in industrial-grade N,N-dimethylformamide (DMF), belongs to the purification technology. Background technique [0002] N, N-dimethylformamide (abbreviated as DMF) is a colorless, transparent liquid with strong polarity and low toxicity, and is a good organic solvent. It is mainly used in industries such as polyurethane slurry, electronics, pharmaceutical intermediates and polypropylene acrylic spinning. [0003] There are many ways to produce N, N-dimethylformamide. At present, most of the industrial methods are one-step synthesis of carbon monoxide and dimethylamine. After the synthesis, the crude product passes through a low-boiling tower and a high-boiling tower to remove light components in the product. and heavy components, and then through a stripping tower, using inert ga...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C233/03C07C231/24
Inventor 杨长生马升勇殷霞
Owner TIANJIN UNIV
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