阅读说明：本技术 一种制备全氟烷基乙烯基醚的反应系统及其方法 (Reaction system and method for preparing perfluoroalkyl vinyl ether ) 是由 应良辰 包俊 王章明 赵景平 陈晓军 吴燕涛 于 2020-11-03 设计创作，主要内容包括：本发明公开了一种制备全氟烷基乙烯基醚的反应系统及其方法,在干燥环境下将全氟烷基乙烯基醚中间体盐溶液打入进料罐中；通过加热部件将脱羧反应管温度预热至100～170℃后,稳定一段时间,通过进料泵将中间体盐溶液由进料罐打入脱羧反应管中开始反应,生成的产物由脱羧反应管中部的出气口排出,经由冷凝器冷凝收集,获得全氟烷基乙烯基醚粗品；脱羧过程中的底液流入到溶剂收集罐中,经由溶剂清洗泵由脱羧反应管进料口打入进行清洗后,经管道进入离心机进行离心分离,分离后的澄清溶剂通过管道进入溶剂回收罐。本发明可以增加溶剂的利用效率,减小反应系统的积盐化。(The invention discloses a reaction system and a method for preparing perfluoroalkyl vinyl ether, wherein perfluoroalkyl vinyl ether intermediate salt solution is pumped into a feeding tank in a dry environment; preheating a decarboxylation reaction tube to 100-170 ℃ by a heating part, stabilizing for a period of time, pumping an intermediate salt solution into the decarboxylation reaction tube from a feeding tank by a feeding pump to start reaction, discharging a generated product from a gas outlet in the middle of the decarboxylation reaction tube, and condensing and collecting by a condenser to obtain a perfluoroalkyl vinyl ether crude product; and the base solution in the decarboxylation process flows into a solvent collection tank, is pumped into a decarboxylation reaction tube feeding port through a solvent cleaning pump for cleaning, then enters a centrifuge through a pipeline for centrifugal separation, and the separated clear solvent enters a solvent recovery tank through a pipeline. The invention can increase the utilization efficiency of the solvent and reduce the salt accumulation of the reaction system.)

1. A reaction system for preparing perfluoroalkyl vinyl ether is characterized in that: comprises a decarboxylation reaction tube provided with a heating part, a feeding tank, a feeding pump, a solvent collecting tank, a solvent cleaning pump, a centrifuge and a solvent recovery tank, the feeding pump is connected with the bottom of the feeding tank and a feeding hole arranged at the feeding end of the decarboxylation reaction tube through a pipeline, pumping the intermediate salt solution into a decarboxylation reaction tube from a feeding tank by a feeding pump, wherein the two ends of the decarboxylation reaction tube are respectively provided with an air inlet and an air outlet for displacing gas, the middle part of the decarboxylation reaction tube is provided with a discharge hole for discharging generated product gas, the solvent cleaning pump is connected with the bottom of the solvent collecting tank, the feed end of the decarboxylation reaction tube and the centrifuge through pipelines, the base solution in the decarboxylation process flows into the solvent collecting tank, and pumping the clear solvent into a decarboxylation reaction pipe through a solvent cleaning pump for cleaning, and then feeding the clear solvent into a centrifuge through a pipeline, wherein the solvent recovery tank is connected with the centrifuge through a pipeline, and the centrifuge separates out the clear solvent and conveys the clear solvent to the solvent recovery tank.

2. The reaction system for preparing perfluoroalkyl vinyl ether according to claim 1, characterized in that: the decarboxylation reaction tube is a straight tube, a spiral coil or a multi-straight tube group.

3. The reaction system for producing a perfluoroalkyl vinyl ether according to claim 2, characterized in that: the decarboxylation reaction tube is in a circular tube, an elliptical tube or a square tube shape.

4. The reaction system for preparing perfluoroalkyl vinyl ether according to claim 1, characterized in that: the heating component comprises a jacket arranged outside the decarboxylation reaction pipe and heat conduction oil arranged in the jacket.

5. A process for preparing a perfluoroalkyl vinyl ether using the reaction system of claim 1, characterized in that: the method comprises the following steps:

(1) carrying out nitrogen replacement, deoxidization and water removal on the reaction system, and pumping the perfluoroalkyl vinyl ether intermediate salt solution into a feeding tank in a dry environment after the oxygen and water contents of the reaction system are less than set values;

(2) preheating a decarboxylation reaction tube to 100-170 ℃ by a heating part, stabilizing for a period of time, pumping an intermediate salt solution into the decarboxylation reaction tube from a feeding tank by a feeding pump to start reaction, discharging a generated product from a gas outlet in the middle of the decarboxylation reaction tube, and condensing and collecting by a condenser to obtain a perfluoroalkyl vinyl ether crude product;

(3) and the base solution in the decarboxylation process flows into a solvent collection tank, is pumped into a decarboxylation reaction tube feeding port through a solvent cleaning pump for cleaning, then enters a centrifuge through a pipeline for centrifugal separation, and the separated clear solvent enters a solvent recovery tank through a pipeline.

6. A process according to claim 5, characterized in that: the perfluoroalkyl vinyl ether intermediate salt solution is obtained by directly reacting acyl fluoride with a salt forming agent in a solvent or by reacting the acyl fluoride with an aqueous solution of the salt forming agent, drying and dissolving in the solvent, wherein the salt forming agent is NaOH, KOH or Na₂CO₃、K₂CO₃One or a combination of any two or more of them.

7. A process according to claim 6, wherein: the solvent is a polar aprotic alcohol ether solvent, and the mass ratio of the polar aprotic alcohol ether solvent to the polar aprotic alcohol ether solvent is 0.4-3.0.

8. A process according to claim 5, characterized in that: the temperature of the decarboxylation reaction tube is controlled to be 135-145 ℃.

9. A process according to claim 5, characterized in that: the oxygen and water content in the reaction system is less than 50 ppm.

Technical Field

The invention relates to a fluorine chemical technology, in particular to a device and a method for preparing perfluoroalkyl vinyl ether.

Background

Perfluoroalkyl vinyl ether is a widely used fluorine-containing monomer, and has a general formula:

perfluoroalkyl vinyl ether is a fluorine-containing vinyl ether, and is used as a comonomer for synthesizing fluoroplastics. Can be used as copolymerization or modification monomer to participate in polymerization to improve some properties of the fluorine polymer, such as: low temperature resistance, solvent resistance, toughness, tearing resistance, bonding property with a base material and the like, and the original corrosion resistance and aging resistance of the polymer are not changed. For example, the fluoroether rubber formed by introducing a perfluoro-n-propyl vinyl ether chain segment into the main chain of the common fluororubber macromolecule improves the flexibility of the molecular chain and improves the low-temperature flexibility of the fluororubber molecular chain. Meanwhile, the molecular structure still contains a tetrafluoroethylene chain segment, the main chemical structure of macromolecules of the tetrafluoroethylene chain segment is not changed, and the outstanding advantages of the tetrafluoroethylene chain segment on chemical medium resistance and high temperature resistance are maintained while the low-temperature performance of the fluororubber is improved.

The decarboxylation method of perfluoroalkyl vinyl ether is a key step in the whole synthesis process, and is mainly divided into two types:

firstly, a solid-phase decarboxylation method is adopted, and perfluoroacyl fluoride is directly used for reacting with metal carbonate in a reactor at the decarboxylation temperature higher than that of intermediate carboxylate to obtain the vinyl ether.

Secondly, adopting a liquid phase decarboxylation method, reacting perfluoroacyl fluoride in a mixture of a solvent and carbonate or a mixture of water and sodium hydroxide, potassium hydroxide or sodium carbonate to generate salt, and then decarboxylating at high temperature to obtain the product.

The decarboxylation processes disclosed in US3291843 and US3321532 of the united states dupont company include: by using diethylene glycol dimethyl ether as a solvent, acyl fluoride and sodium carbonate form salt at 60 ℃, and decarboxylation is performed when the temperature is heated to 140 ℃ to obtain a product, wherein the yield reaches 97.2%; by adopting a tubular reactor, acyl fluoride and sodium carbonate are directly salified and decarboxylated at 300 ℃, and the yield is up to 95%; the same tubular reactor is used, and acyl fluoride and silicon oxide are cracked into ether at 390 ℃, and the yield is 85% at most. The method has the yield higher than the actual level.

The patent CN01813464.5 of Asahi glass company, which is a method for producing fluorine-containing acyl fluoride and fluorine-containing vinyl ether by using a fluidized bed, shows that the conversion rate is 100% and the yield is 55%.

The patent CN200680023824.4 of 3M Innovation limited company adopts a conventional solid phase decarboxylation method, and utilizes the decarboxylation reaction of acyl fluoride and metal carbonate in a stirred bed reactor at a high temperature of 100-300 ℃, so that the yield is about 70%.

The decarboxylation method in patent CN200710160650.2 of Zhonghao Chen optical chemical research institute is as follows: organic amine is added into a polar solvent as a catalyst, and perfluoroalkoxy propionyl fluoride and carbonate form salt at low temperature and are decarboxylated at high temperature to generate perfluoro-n-propyl vinyl ether. The yield reaches 92.3%, and the yield is lower in the comparative example without the amine catalyst, and is only 72.2%.

In summary, the current decarboxylation process has the following disadvantages: the solid phase decarboxylation reaction temperature is high, a large number of byproducts are generated, the yield is low, and the reactor is easy to form carbon and stick to the wall and is difficult to clean; the liquid phase decarboxylation solvent has large demand, long product retention time, more byproducts and complex operation.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a reaction system for preparing perfluoroalkyl vinyl ether, which can increase the utilization efficiency of a solvent and reduce the salt accumulation of the reaction system.

In order to solve the technical problems, the invention adopts the following technical scheme: a reaction system for preparing perfluoroalkyl vinyl ether comprises a decarboxylation reaction tube, a feeding tank, a feeding pump, a solvent collecting tank, a solvent cleaning pump, a centrifugal machine and a solvent recovery tank which are provided with heating parts, wherein the feeding pump is connected with a feeding port arranged at the bottom of the feeding tank and at the feeding end of the decarboxylation reaction tube through a pipeline, an intermediate salt solution is pumped into the decarboxylation reaction tube from the feeding tank through the feeding pump, the two ends of the decarboxylation reaction tube are respectively provided with an air inlet and an air outlet for displacing gas, the middle part of the decarboxylation reaction tube is provided with a discharge port for discharging generated product gas, the solvent cleaning pump is connected with the bottom of the solvent collecting tank and the feeding end of the decarboxylation reaction tube through a pipeline, the centrifugal machine is connected with the solvent through a pipeline, bottom liquid in the decarboxylation process flows into the solvent collecting tank, and is pumped into the decarboxylation reaction tube through the, the centrifuge separates the clarified solvent and delivers it to a solvent recovery tank.

Preferably, the decarboxylation reaction tube is a straight tube, a spiral coil or a multi-straight tube group.

Preferably, the decarboxylation reaction tube is in the shape of a circular tube, an elliptical tube or a square tube.

Preferably, the heating component comprises a jacket arranged outside the decarboxylation reaction tube and heat conduction oil arranged in the jacket.

The invention also provides a method for preparing perfluoroalkyl vinyl ether, which comprises the following steps:

(1) carrying out nitrogen replacement, deoxidization and water removal on the reaction system, and pumping the perfluoroalkyl vinyl ether intermediate salt solution into a feeding tank in a dry environment after the oxygen and water contents of the reaction system are less than set values;

(2) preheating a decarboxylation reaction tube to 100-170 ℃ by a heating part, stabilizing for a period of time, pumping an intermediate salt solution into the decarboxylation reaction tube from a feeding tank by a feeding pump to start reaction, discharging a generated product from a gas outlet in the middle of the decarboxylation reaction tube, and condensing and collecting by a condenser to obtain a perfluoroalkyl vinyl ether crude product;

(3) and the base solution in the decarboxylation process flows into a solvent collection tank, is pumped into a decarboxylation reaction tube feeding port through a solvent cleaning pump for cleaning, then enters a centrifuge through a pipeline for centrifugal separation, and the separated clear solvent enters a solvent recovery tank through a pipeline.

Preferably, the perfluoroalkyl vinyl ether intermediate salt solution is obtained by directly reacting acyl fluoride and a salt forming agent in a solventOr obtained by reacting acyl fluoride with aqueous solution of salt forming agent, drying and dissolving in solvent, wherein the salt forming agent is NaOH, KOH or Na₂CO₃、K₂CO₃One or a combination of any two or more of them.

Preferably, the solvent is a polar aprotic alcohol ether solvent, and the mass ratio of the polar aprotic alcohol ether solvent to the polar aprotic alcohol ether solvent is 0.4-3.0. A

Preferably, the temperature of the decarboxylation reaction tube is controlled to be 135-145 ℃.

Preferably, the oxygen and water content in the reaction system is less than 50 ppm.

By adopting the technical scheme, the invention has the following beneficial effects:

the reaction system is isolated from the external environment, so that the safety of the process is improved. The intermediate salt solution is pumped into the decarboxylation reaction tube by the feeding pump through the feeding tank for continuous reaction, so that the production efficiency is improved. The gas phase crude product generated by the reaction is discharged out of the reaction system in time through a discharge hole. Therefore, the safety, controllability, continuity and high efficiency of the reaction are ensured.

In the process of the intermediate salt solution flowing in the reaction tube, the intermediate salt is heated uniformly and decomposed thoroughly, so that the product yield can reach more than 95 percent at most; in addition, because the solvent layer is thin, the retention time of the product in the solvent is short, the byproducts are reduced, and the selectivity of the product is improved.

And the base solution in the decarboxylation process flows into a solvent collection tank, is pumped into a decarboxylation reaction tube feeding port through a solvent cleaning pump for cleaning, then enters a centrifuge through a pipeline for centrifugal separation, and the separated clear solvent enters a solvent recovery tank through a pipeline. Therefore, the utilization efficiency of the solvent can be effectively increased, and the salt deposition in the reaction system can be reduced.

The following detailed description of the present invention will be provided in conjunction with the accompanying drawings.

Drawings

The invention is further described with reference to the accompanying drawings and the detailed description below:

FIG. 1 is a schematic view of the final assembly of the present invention;

in the figure: 1-a feeding tank, 2-a feeding pump, 3-a decarboxylation reaction tube, 4-a heat exchanger, 5-a solvent collecting tank, 6-a solvent cleaning pump, 7-a centrifuge and 8-a solvent recovery tank.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

As shown in figure 1, a reaction system for preparing perfluoroalkyl vinyl ether comprises a decarboxylation reaction tube 3 provided with a heating part, a feeding tank 1, a feeding pump 2, a solvent collecting tank 5, a solvent cleaning pump 6, a centrifuge 7 and a solvent recovery tank 8, wherein the feeding pump is connected with feeding ports arranged at the bottom of the feeding tank and the feeding end of the decarboxylation reaction tube through pipelines, an intermediate salt solution is pumped into the decarboxylation reaction tube from the feeding tank through the feeding pump, both ends of the decarboxylation reaction tube are respectively provided with an air inlet and an air outlet for displacing gas, the middle part of the decarboxylation reaction tube is provided with a discharge port for discharging generated product gas, the solvent cleaning pump is connected with the bottom of the solvent collecting tank, the feeding end of the decarboxylation reaction tube and the centrifuge through pipelines, a base solution in the decarboxylation process flows into the solvent collecting tank, after the reaction is completed, the base solution is pumped into the decarboxylat, the solvent enters a centrifuge through a pipeline, the solvent recovery tank is connected with the centrifuge through a pipeline, and the centrifuge separates out the clarified solvent and conveys the clarified solvent to the solvent recovery tank.

It will be appreciated that the decarboxylation reaction tubes may take a variety of forms, with particular reference to the prior art, and may be, for example, straight tubes, helical coils, or groups of straight tubes. The decarboxylation reaction tube can be a round tube, an elliptical tube or a square tube.

In order to realize uniform heating, an oil bath is used for heating, the heating component comprises a jacket arranged outside the decarboxylation reaction pipe and heat conducting oil arranged in the jacket, the heat conducting oil enters from an inlet at one end and exits from an outlet at the other end, and oil bath circulation is realized. In addition, a heat exchanger 4 is also arranged to heat the heat-conducting oil.

Furthermore, the decarboxylation reaction tube is obliquely arranged, namely the feeding end is higher than the discharging end. So as to be beneficial to conveying the reaction materials from the feeding end to the discharging end.

Example two

A process for preparing a perfluoroalkyl vinyl ether using the reaction system of example one, comprising the steps of:

(1) carrying out nitrogen replacement, deoxidization and water removal on the reaction system, and pumping the perfluoroalkyl vinyl ether intermediate salt solution into a feeding tank in a dry environment after the oxygen and water contents of the reaction system are less than set values;

(2) preheating a decarboxylation reaction tube to 100-170 ℃ by a heating part, stabilizing for a period of time, pumping an intermediate salt solution into the decarboxylation reaction tube from a feeding tank by a feeding pump to start reaction, discharging a generated product from a gas outlet in the middle of the decarboxylation reaction tube, and condensing and collecting by a condenser to obtain a perfluoroalkyl vinyl ether crude product;

(3) and the base solution in the decarboxylation process flows into a solvent collection tank, is pumped into a decarboxylation reaction tube feeding port through a solvent cleaning pump for cleaning, then enters a centrifuge through a pipeline for centrifugal separation, and the separated clear solvent enters a solvent recovery tank through a pipeline.

Wherein, the perfluoroalkyl vinyl ether intermediate salt solution is obtained by directly reacting acyl fluoride with a salt forming agent in a solvent or by reacting the acyl fluoride with an aqueous solution of the salt forming agent, drying and dissolving in the solvent, and the salt forming agent is NaOH, KOH or Na₂CO₃、K₂CO₃One or a combination of any two or more of them. The solvent is a polar aprotic alcohol ether solvent, such as ethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether, and the mass ratio of the solvents is 0.4-3.0.

The temperature of the decarboxylation reactor has great influence on the selectivity of the product, and if the temperature is too high, the content of the by-product is increased, and the selectivity of the product is reduced; if the temperature is too low, the conversion of the raw material is too low. In this embodiment, the temperature of the decarboxylation reaction tube is controlled to be 100-170 ℃, preferably 135-145 ℃.

The reaction system needs to be completely sealed and dried in the reaction process, and the oxygen and water content in the reaction system is less than 50ppm after the oxygen and water are removed by nitrogen replacement.

In the invention, the required solvent is continuously added into the decarboxylation reaction tube through a feeding pump according to the process requirement; raw materials required by the reaction can be supplemented to the feeding tank regularly, the whole operation is carried out in a dry and air-isolated state, the feeding rate can be adjusted by the feeding pump to change the reaction time, the gas-phase crude product generated by the reaction can be discharged out of the reaction system in time, and the safety, controllability, continuity and high efficiency of the reaction are ensured. Part of by-product metal fluoride salt generated in the reaction stays in the tube, the by-product salt in the tube can be removed by a strong scouring effect generated by the circulating cleaning of the solvent cleaning pump, the solvent after the reaction flows into a centrifuge through the solvent cleaning pump for centrifugal separation, and the clarified solvent can be recycled for multiple times. Therefore, the utilization efficiency of the solvent is increased, and the salt deposition in the reaction system is reduced.

The purity of the crude product of the perfluoroalkyl vinyl ether prepared by the reaction system of the invention and the method can reach more than 97 percent, and the pure product of the perfluoroalkyl vinyl ether with the purity of more than 99.9 percent can be obtained after rectification. The content of byproduct salt of the clarified liquid after the solvent is separated by a centrifuge is lower than 0.5 percent, and the utilization rate of the solvent is higher than 90 percent.

Example 1

The method comprises the steps of carrying out nitrogen replacement on the whole set of reaction system, ensuring that the oxygen and water content in the system is less than 50ppm, taking 16kg of a sodium carboxylate intermediate which is generated in a salt forming reactor and completely dried, adding 32kg of diethylene glycol dimethyl ether solvent to fully dissolve, adding the sodium carboxylate intermediate into a feeding tank in batches, ensuring continuous supply of raw materials, slowly heating a reaction tube for 1h to 140 ℃ in advance through a jacket, keeping the temperature stable for 0.5h, pumping the raw materials into the reaction tube from a feeding hole of the reaction tube by a feeding pump to react, stopping the reaction after the feeding is finished, condensing and collecting 11638.7g of products by a condensing device, wherein the yield of the crude products is 96.26%, simultaneously starting a solvent cleaning pump to flush the reaction tube for about 1h, and then introducing a base solution into a. The product collected by chromatography had a perfluoroalkyl vinyl ether content of 97.36%.

Example 2

The method comprises the steps of carrying out nitrogen replacement on the whole set of reaction system, ensuring that the oxygen and water content in the system is less than 50ppm, taking 16kg of carboxylic acid sylvite intermediate which is generated in a salt forming reactor and completely dried, adding 32kg of diethylene glycol dimethyl ether solvent for full dissolution, adding the carboxylic acid sylvite intermediate into a feeding tank in batches, ensuring continuous supply of raw materials, slowly heating a reaction tube for 1h to 140 ℃ in advance through a jacket, keeping the temperature stable for 0.5h, pumping the raw materials into the reaction tube from a feeding hole of the reaction tube by a feeding pump for reaction, stopping the reaction after the feeding is finished, condensing and collecting 11562.5g of products by a condensing device, wherein the total yield is 95.63%, simultaneously starting a solvent cleaning pump to flush the reaction tube for about 1h, and then introducing a base solution. The product collected by chromatography had a perfluoroalkyl vinyl ether content of 97.52%.

Example 3

The method comprises the steps of carrying out nitrogen replacement on the whole set of reaction system, ensuring that the oxygen and water content in the system is less than 50ppm, taking 16kg of a sodium carboxylate intermediate which is generated in a salt forming reactor and completely dried, adding 32kg of tetraethylene glycol dimethyl ether solvent to fully dissolve, adding the sodium carboxylate intermediate into a feeding tank in batches, ensuring continuous supply of raw materials, slowly heating a reaction tube for 1h to 140 ℃ in advance through a jacket, keeping the temperature stable for 0.5h, pumping the raw materials into the reaction tube from a feeding hole of the reaction tube by a feeding pump to react, stopping the reaction after the feeding is finished, condensing and collecting 11278.4g of products by a condensing device, wherein the total yield is 95.28%, simultaneously starting a solvent cleaning pump to flush the reaction tube for about 1h, and then introducing a base solution into a centrifugal machine. The product collected by chromatography contained a perfluoroalkyl vinyl ether content of 97.87%.

Example 4

The method comprises the steps of carrying out nitrogen replacement on the whole set of reaction system, ensuring that the oxygen and water content in the system is less than 50ppm, taking 16kg of a sodium carboxylate intermediate which is generated in a salt forming reactor and completely dried, adding 24kg of diethylene glycol dimethyl ether solvent to fully dissolve, adding the sodium carboxylate intermediate into a feeding tank in batches, ensuring continuous supply of raw materials, slowly heating a reaction tube for 1h to 140 ℃ in advance through a jacket, keeping the temperature stable for 0.5h, pumping the raw materials into the reaction tube from a feeding hole of the reaction tube by a feeding pump to react, stopping the reaction after the feeding is finished, condensing and collecting 11532.3g of products by a condensing device, wherein the total yield is 95.38%, simultaneously starting a solvent cleaning pump to flush the reaction tube for about 1h, and then introducing a base solution into a centrifugal machine to. The product collected by chromatography had a perfluoroalkyl vinyl ether content of 97.06%.

Example 5

The method comprises the steps of carrying out nitrogen replacement on the whole set of reaction system, ensuring that the oxygen and water content in the system is less than 50ppm, taking 16kg of a sodium carboxylate intermediate which is generated in a salt forming reactor and completely dried, adding 32kg of diethylene glycol dimethyl ether solvent to fully dissolve, adding the sodium carboxylate intermediate into a feeding tank in batches, ensuring continuous supply of raw materials, slowly heating a reaction tube for 1h to 130 ℃ in advance through a jacket, keeping the temperature stable for 0.5h, pumping the raw materials into the reaction tube from a feeding hole of the reaction tube by a feeding pump to react, stopping the reaction after the feeding is finished, condensing and collecting 11529.9g of products by a condensing device, wherein the total yield is 95.36%, simultaneously starting a solvent cleaning pump to flush the reaction tube for about 1h, and introducing a base solution into a centrifugal machine to carry. The product collected by chromatography analysis contained a perfluoroalkyl vinyl ether content of 97.85%.

Example 6

Carrying out nitrogen replacement on the whole reaction system to ensure that the oxygen and water content in the system is less than 50ppm, taking 16kg of a sodium carboxylate intermediate which is generated in a salt forming reactor and completely dried by reaction, adding 32kg of diethylene glycol dimethyl ether solvent to fully dissolve, adding the mixture into a feeding tank in batches to ensure the continuous supply of raw materials, slowly heating a reaction tube for 1h to 140 ℃ in advance through a jacket, keeping the temperature stable for 0.5h, pumping the raw materials into the reaction tube from a feeding port of the reaction tube by a feeding pump to react, and carrying out reaction in the reaction processContinuously introducing N into the reaction tube₂. And stopping the reaction after the feeding is finished, condensing and collecting 11517.8g of products through a condensing device, wherein the total yield is 95.26%, and simultaneously starting a solvent cleaning pump to wash the reaction tube for about 1h, and introducing the base solution into a centrifugal machine for centrifugal separation. The product collected by chromatography had a perfluoroalkyl vinyl ether content of 97.36%.

Other embodiments of the present invention than the preferred embodiments described above, and those skilled in the art can make various changes and modifications according to the present invention without departing from the spirit of the present invention, should fall within the scope of the present invention defined in the claims.