Method for preparing vinylene carbonate

A technology of vinylene carbonate and ethylene carbonate, which is applied in the field of preparation of vinylene carbonate, can solve the problems of low yield of vinylene carbonate and difficult separation of products, and achieve easy separation and purification, easy availability of raw materials, and low price Effect

Active Publication Date: 2008-07-02
BYD CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome the disadvantages of low vinylene carbonate yield and difficult separation of products in the preparation method of vinylen

Method used

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Examples

Experimental program
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Effect test

preparation example Construction

[0008] According to the preparation method of vinylene carbonate provided by the invention, since vinylene carbonate is very sensitive to moisture, in order to minimize the decomposition of vinylene carbonate and avoid the generation of other possible side reactions, in the present invention, the The moisture content in the ammonia as dehydrohalogenation agent is not more than 0.1%, more preferably not more than 0.05%. Ammonia can be dried by contacting it with a desiccant.

[0009] According to the preparation method provided by the invention, although the present invention can be realized with various proportioning ratios between the reactants, due to the wide source of ammonia, the raw materials are easy to get and cheap, and most importantly, because excessive ammonia is easy to mix with Other reaction raw materials and reaction product are separated, can directly recycle, therefore, under preferred circumstances, ammonia is greatly excessive among the present invention, f...

Embodiment 1

[0022] This embodiment is used to illustrate the preparation method of vinylene carbonate provided by the invention.

[0023]Mix 200 grams of chloroethylene carbonate with 40 milliliters of 18-crown ether-6 and 400 milliliters of anhydrous tetrahydrofuran in a four-necked flask with a thermometer, a stirrer and a gas inlet and a gas outlet to obtain a mixture containing 18-crown A mixed solution of ether-6, tetrahydrofuran and monochloroethylene carbonate. Then at a stirring speed of 130 rev / min at 50°C, the dry ammonia gas with a purity of 99.9% is passed under the liquid surface at a rate of 0.15 g / min through the gas inlet, while excess ammonia escapes from the gas outlet to the Another ammonia bag, collected for recycling. The reaction temperature was controlled to be 50° C. and the above-mentioned dry ammonia gas was continuously fed at this temperature for 10 hours, and then the ammonia gas was stopped. Then the reaction mixture was filtered, and then distilled under r...

Embodiment 2

[0025] This embodiment is used to illustrate the preparation method of vinylene carbonate provided by the invention.

[0026] Mix 200 grams of chloroethylene carbonate and 400 milliliters of anhydrous tetrahydrofuran in a four-necked flask with a thermometer, a stirrer, and a gas inlet and a gas outlet to obtain a mixed solution containing tetrahydrofuran and chloroethylene carbonate. Then pass the dry ammonia gas with a purity of 99.9% through the gas inlet at 50°C at a stirring speed of 130 rpm at a rate of 0.15 g / min under the liquid surface, while unreacted ammonia gas escapes from the gas outlet into another ammonia bag, collected for recycling. The reaction temperature was controlled to be 50° C. and the above-mentioned dry ammonia gas was continuously fed at this temperature for 10 hours, and then the ammonia gas was stopped. Then the reaction mixture was filtered, and then distilled under reduced pressure with an oil pump to collect fractions at 46-50° C. (3 mmHg) to ...

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Abstract

The invention relates to a preparation method of vinylene carbonate, which comprises halogenated ethylene carbonate and dehydrohalogenation agent which are subject to contact reaction. The dehydrohalogenation agent is ammonia with a purity of not less than 99.9 percent. The yield of the vinylene carbonate prepared by adopting the method provided by the invention reaches as high as 85 percent, resultant can be quite easily separated and purified, and the purity of the resultant can reach 99.5 percent (GC) through general distillation and a crystallization method. Raw materials of the dehydrohalogenation agent can be easily obtained at low price; furthermore, excessive ammonia can be recycled, so the production cost is greatly reduced compared with using organic amine as the dehydrohalogenation agent. In addition, molecular weight of the ammonia that is used as the dehydrohalogenation agent is small, thus greatly reducing the weight of side products under the same situation.

Description

technical field [0001] The invention relates to a preparation method of vinylene carbonate. Background technique [0002] As a highly reactive additive in lithium-ion secondary batteries, vinylene carbonate can inhibit various undesirable reactions in the electrolyte, such as the decomposition of lithium hexafluorophosphate into LiF. Vinylene carbonate can form an SEI film with excellent performance on the surface of the negative electrode of lithium-ion secondary batteries, thereby improving the charge-discharge efficiency and cycle characteristics of lithium-ion secondary batteries, so it is becoming more and more popular. [0003] American Chemical Journal, 77,3789-3793 (1995) discloses a kind of preparation method of vinylene carbonate, this method comprises at first preparing monochloroethylene carbonate by the chlorination reaction of ethylene carbonate, then with monochloroethylene carbonate The ester was reacted overnight with triethylamine under reflux in an ether ...

Claims

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Application Information

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IPC IPC(8): C07D317/40
Inventor 胡翼飞罗朝辉
Owner BYD CO LTD
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