阅读说明：本技术 氟代碳酸乙烯酯的生产方法 (Production method of fluoroethylene carbonate ) 是由 宋芬 粟小理 黄梅红 杨伟领 黄晓云 于 2018-03-20 设计创作，主要内容包括：本发明涉及一种氟代碳酸乙烯酯的生产方法,主要解决现有技术中催化剂成本高、产品收率低的问题。本发明通过采用一种氟代碳酸乙烯酯的生产方法,将氯代碳酸乙烯酯加到反应器中,然后加入极性非质子性溶剂、催化剂、氟化试剂,在一定反应条件进行反应,反应完毕后,反应液经分离单元分离后获得氟代碳酸乙烯酯产品的技术方案较好地解决了上述问题,可用于氟代碳酸乙烯酯的生产中。(The invention relates to a production method of fluoroethylene carbonate, which mainly solves the problems of high cost of a catalyst and low product yield in the prior art. The invention adopts a production method of fluoroethylene carbonate, the chloroethylene carbonate is added into a reactor, then a polar aprotic solvent, a catalyst and a fluorination reagent are added for reaction under certain reaction conditions, and after the reaction is finished, reaction liquid is separated by a separation unit to obtain fluoroethylene carbonate products.)

1. A method for producing fluoroethylene carbonate comprises the steps of adding chloroethylene carbonate into a reactor, then adding a polar aprotic solvent, a catalyst and a fluorination reagent, reacting under certain reaction conditions, and separating reaction liquid by a separation unit after the reaction is finished to obtain fluoroethylene carbonate products; wherein, the catalyst is a calixarene phase transfer catalyst, and the structural formula is as follows:

in the formula: r is selected from methyl, ethyl, n-propyl, isopropyl, butyl, tert-amyl, isoamyl, methoxyl, ethoxyl or isopropoxy, and n is 4-8.

2. The method for producing fluoroethylene carbonate according to claim 1, wherein R is selected from the group consisting of methoxy group and tert-butyl group, and n-4-6.

3. The method for producing fluoroethylene carbonate according to claim 1, wherein the polar aprotic solvent is at least one of ethyl acetate, methyl acetate, dimethyl carbonate, diethyl carbonate, acetonitrile; the fluorinating agent is at least one of potassium fluoride and sodium fluoride.

4. The method for producing fluoroethylene carbonate according to claim 3, wherein the polar aprotic solvent is dimethyl carbonate; the fluorinating agent is potassium fluoride.

5. The method for producing fluoroethylene carbonate according to claim 2, wherein R is selected from the group consisting of t-butyl and n-6.

6. The method for producing fluoroethylene carbonate according to claim 1, wherein the feed molar ratio of chloroethylene carbonate, fluorinating agent and catalyst is 1: 1-5: 0.0001-0.027.

7. The method for producing fluoroethylene carbonate according to claim 6, wherein the feed molar ratio of chloroethylene carbonate, fluorinating agent and catalyst is 1: 1-3: 0.0001-0.015.

8. The process for producing fluoroethylene carbonate according to claim 1, wherein the reaction conditions are: the reaction temperature is 20-170 ℃, and the reaction time is 0.5-20 hours.

9. The process for producing fluoroethylene carbonate according to claim 8, wherein the reaction conditions are: the reaction temperature is 50-140 ℃, and the reaction time is 1-8 hours.

10. The method for producing fluoroethylene carbonate according to claim 1, wherein the reactor is a reaction kettle, and the reaction solution after the reaction is filtered, rectified and refined to obtain fluoroethylene carbonate product with purity of more than 99.95%; and the catalyst in the filtrate is recycled after filtration.

Technical Field

The invention relates to a method for producing fluoroethylene carbonate, and mainly relates to a method for synthesizing fluoroethylene carbonate by taking calixarene as a phase transfer catalyst.

Background

Fluoroethylene carbonate (FEC) is used as an additive with excellent performance for lithium ion battery electrolytes. The fluoroethylene carbonate can be used as an additive of the lithium ion battery electrolyte, and generally has higher requirements on purity and acidity. FEC is susceptible to reductive decomposition at higher potentials due to the electron-withdrawing effect of fluorine atoms. Therefore, the decomposition and reduction of the electrolyte solvent under a lower potential can be effectively inhibited by adding the FEC into the electrolyte, and an SEI film layer (a solid electrolyte liquid phase interface film) formed by FEC decomposition products on the surface of the electrode is thinner and more stable, so that lithium ion deintercalation is facilitated, the SEI film impedance and the total impedance of the battery are further reduced, and the cycle performance and the safety of the battery are improved.

The synthetic methods of fluoroethylene carbonate are mainly divided into the following three types: (1) the ethylene carbonate route uses F2 direct fluorination (US20060167279, US20050072123, US 20060036102). Fluorine fluorination has the defects of difficult reaction control, poor selectivity, high equipment investment and the like. (2) The hydrogen fluoride is a fluorinating agent, and reacts with CEC in the presence of organic bases such as triethylamine, pyridine and the like, wherein the FEC yield is 65 percent, and the purity is 99.8 percent. (US 2011009644A). (3) Fluorizating fluoride salt, namely fluorizating chloride ethylene carbonate serving as a raw material by potassium fluoride under the action of a phase transfer catalyst. The route is a main research route at present, and mainly focuses on the selection of phase transfer catalysts, such as quaternary ammonium salts (Guangzhou chemical industry, 2012,40, 97), crown ethers (CN200610156068), quaternary phosphorus salts (CN201310383253), cyclodextrins (CN201210363874) and ionic liquids (CN201310535094, CN201410009401 and CN 200910237020).

Disclosure of Invention

The invention aims to solve the technical problems of high catalyst cost and low product yield in the prior art, and provides a novel production method of fluoroethylene carbonate, which has the advantages of low catalyst cost and high product yield.

In order to solve the problems, the technical scheme adopted by the invention is as follows: a method for producing fluoroethylene carbonate comprises the steps of adding chloroethylene carbonate into a reactor, then adding a polar aprotic solvent, a catalyst and a fluorination reagent, reacting under certain reaction conditions, and separating reaction liquid by a separation unit after the reaction is finished to obtain fluoroethylene carbonate products; wherein, the catalyst is a calixarene phase transfer catalyst, and the structural formula is as follows:

in the formula: r is selected from methyl, ethyl, n-propyl, isopropyl, butyl, tert-amyl, isoamyl, methoxyl, ethoxyl or isopropoxy, and n is 4-8.

In the above technical solution, R is preferably selected from methoxy and tert-butyl, and n ═ 4-6.

In the above technical solution, more preferably, R is selected from tert-butyl and n ═ 6.

In the above technical solution, preferably, the polar aprotic solvent is at least one of ethyl acetate, methyl acetate, dimethyl carbonate, diethyl carbonate, and acetonitrile; the fluorinating agent is at least one of potassium fluoride and sodium fluoride.

In the above technical solution, preferably, the polar aprotic solvent is dimethyl carbonate; the fluorinating agent is potassium fluoride.

In the above technical solution, preferably, the feeding molar ratio of the chloroethylene carbonate, the fluorination reagent and the catalyst is 1: 1-5: 0.0001-0.027.

In the above technical solution, more preferably, the charging molar ratio of the chloroethylene carbonate, the fluorination reagent and the catalyst is 1: 1-3: 0.0001-0.015.

In the above technical solution, preferably, the reaction conditions are: the reaction temperature is 20-170 ℃, and the reaction time is 0.5-20 hours.

In the above technical solution, more preferably, the reaction conditions are: the reaction temperature is 50-140 ℃, and the reaction time is 1-8 hours.

In the above technical scheme, preferably, the reactor is a reaction kettle, and the reaction solution after reaction is filtered, rectified and precisely rectified to obtain fluoroethylene carbonate product with purity of more than 99.95%; and the catalyst in the filtrate is recycled after filtration.

The separation unit comprises the steps of filtering, rectifying, precise rectifying and the like, and technical personnel can reasonably select the process parameters and the separation equipment of the separation unit according to the physical properties of the product.

The invention provides a method for synthesizing fluoroethylene carbonate by taking chloroethylene carbonate as a raw material, which comprises the following steps: (1) adding chloroethylene carbonate into a reaction kettle, adding a polar aprotic solvent, a calixarene catalyst and a fluorination reagent for reaction; (2) and after the reaction is finished, filtering and rectifying the reaction liquid, and further refining to obtain the high-purity fluoroethylene carbonate. The invention has the characteristics of low catalyst price, mild reaction conditions, high yield, easy industrialization and the like, and the calixarene catalyst can effectively shorten the reaction time, reduce the generation of byproducts, improve the product yield and obtain better technical effects.

The present invention will be further illustrated by the following examples, but is not limited to these examples.

Detailed Description