Hexafluoropropylene oxide and synthesis method and synthesis device thereof

Abstract

The invention belongs to the technical field of organic fluorine chemical industry, and particularly relates to hexafluoropropylene oxide as well as a synthesis method and a synthesis device thereof. The synthetic method of the hexafluoropropylene oxide comprises the following processes: firstly, heating dimethyl sulfide and monochlorodifluoromethane in a solvent for reaction, then adding the obtained intermediate into a sodium hydride solution at 30-50 DEG C for reaction to obtain a reaction solution, finally, adding trifluoroacetyl fluoride into the reaction solution for reaction at 15-30 DEG C, treating the obtained reaction solution, and finally, separating and purifying to obtain the hexafluoropropylene oxide. The hexafluoropropylene oxide is obtained. And recovering the solvent and dimethyl sulfide. The synthesis method of hexafluoropropylene oxide provided by the invention is mild in reaction condition and stable in reaction, the synthesized hexafluoropropylene oxide is high in yield and high in purity, and the invention also provides a synthesis device of hexafluoropropylene oxide, which is low in energy consumption.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic fluorine chemical industry, and in particular relates to hexafluoropropylene oxide and a synthesis method and a synthesis device thereof. Background Art

[0002] Hexafluoropropylene oxide (HFPO, C3F6O) is an essential fluorinated intermediate in the fluorine chemical industry. It is primarily produced by the oxidation of hexafluoropropylene (HFP). Its unique perfluoroepoxy structure endows its downstream derivatives (such as perfluoropolyethers, fluororubbers, and specialty fluorosurfactants) with exceptional chemical inertness, excellent extreme-temperature resistance, and outstanding hydrophobic and oleophobic properties. These properties make HFPO and its derivatives valuable in applications requiring stringent performance, such as aerospace lubricants, protective coatings for the semiconductor industry, and high-end waterproof and antifouling materials.

[0003] Currently, the core industrial route for synthesizing HFPO is the oxidation of hexafluoropropylene (HFP). However, this process faces a series of significant technical bottlenecks and challenges in achieving large-scale and economical production.

[0004] The primary challenge lies in the safety risks of the reaction process. The synthesis of HFPO typically requires the oxidation of HFP using oxygen (or an oxygen-rich atmosphere) at relatively high temperatures and pressures. For example, the continuous production process disclosed in patent CN118324721A, while achieving relatively mild reaction conditions through process optimization, still requires oxygen oxidation at temperatures above 100°C. This combination of flammable and explosive gases (oxygen) and organic matter at high temperatures and pressures inherently carries significant safety risks, including uncontrolled oxidation and even explosions. This places extremely high demands on the reliability of the production equipment, process control precision, and operational safety management.

[0005] Secondly, high equipment investment and operational complexity are limiting factors. To improve reaction safety and control precision, some technical routes (such as patent CN104672177A) utilize advanced microchannel reactors. While this type of equipment can effectively avoid the risks of "temperature runaway" and "oxygen explosion" in traditional reactors, achieve precise temperature control, and improve reaction conversion and selectivity, its manufacturing and maintenance costs are extremely high. More importantly, the process faces a dilemma in pursuing acceptable yields: in the low-temperature and low-pressure stage, the reactant feed ratio needs to be increased and the residence time extended, resulting in reduced time and space efficiency; if the efficiency is improved by switching to high-temperature and high-pressure conditions, the equipment investment cost and the reliance on operator expertise are further increased.

[0006] Furthermore, bottlenecks in reaction efficiency and product purification are equally prominent. Existing processes generally suffer from long reaction times and suboptimal overall yields. Furthermore, the HFP oxidation process inevitably produces a variety of byproducts, resulting in a complex composition of the reaction products. This complexity makes subsequent efficient separation and high-purity HFPO from the mixture extremely difficult, and the purification steps are cumbersome and costly, significantly impacting the economic benefits of the entire production process.

[0007] In summary, the current mainstream HFP oxidation process for HFPO synthesis is primarily limited in its industrial application by multiple factors, including inherent safety risks in the production process, high equipment investment (especially when microreactors or high-temperature and high-pressure equipment are involved), relatively harsh operating conditions, suboptimal reaction efficiency (yield / space-time yield), and the difficulty and high cost of separation and purification due to the large number of by-products. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a method for synthesizing hexafluoropropylene oxide. The reaction conditions are mild, the reaction is stable, and the synthesized hexafluoropropylene oxide has a high yield and high purity. The present invention also provides a synthesis device for hexafluoropropylene oxide, which is simple to operate and convenient for industrial production.

[0009] The method for synthesizing hexafluoropropylene oxide of the present invention comprises the following steps: first, dimethyl sulfide and a solvent are mixed and heated for reaction, and monochlorodifluoromethane is added to obtain an intermediate; then, the intermediate is injected into a sodium hydride solution at 30-50°C to obtain a reaction liquid; finally, trifluoroacetyl fluoride is injected into the reaction liquid and reacted at 15-30°C; and the obtained reaction liquid is treated to obtain hexafluoropropylene oxide. The solvent and dimethyl sulfide are recovered.

[0010] The ingredients are prepared according to the following molar ratio: monochlorodifluoromethane: dimethyl sulfide: sodium hydride: trifluoroacetyl fluoride = 1.1-1.3: 1.08-1.2: 1: 1.05-1.15.

[0011] The sodium hydride solution is prepared by dispersing sodium hydride in a solvent, and the solvent is tetrahydrofuran or dimethyl sulfoxide.

[0012] The passing acceleration of the chlorodifluoromethane is 0.8-1.5 kg / h.

[0013] The passing acceleration of the trifluoroacetyl fluoride is 1.096-1.542 kg / h.

[0014] Mix dimethyl sulfide and solvent and heat to 60~75℃ for reaction.

[0015] The intermediate was poured into a sodium hydride solution, the temperature in the reaction tank 2 was set to 30-50°C, and the vertical condenser 1 installed on the top of the reaction tank 2 was set to 10-20°C.

[0016] When injecting trifluoroacetyl fluoride, the temperatures of the tubular reactor, the third reaction tank, and the second vertical condenser are set to 15-30°C, 15-30°C, and 5-10°C, respectively.

[0017] The purity of the monochlorodifluoromethane, dimethyl sulfide, sodium hydride, and trifluoroacetyl fluoride is 99.5%, 99.5%, and 99.5%, respectively. However, the actual calculated dosages are all based on 100%.

[0018] Hexafluoropropylene oxide is synthesized by the hexafluoropropylene oxide synthesis method.

[0019] The hexafluoropropylene oxide synthesis device includes a second reaction tank and a third reaction tank. A filler 1 is installed on the top of the second reaction tank, which is connected to a vertical condenser 1, which is connected to a hydrogen processing device. A filler 2 is provided on the top of the third reaction tank, which is connected to a vertical condenser 2, which is connected to a hexafluoropropylene oxide processing device.

[0020] Specifically, the synthesis method of hexafluoropropylene oxide comprises the following steps: (1) The system was replaced with nitrogen, and then negative pressure was drawn to add the solvent and dimethyl sulfide into the reaction tank 1 for stirring and mixing. The temperature of the mixed system was raised to 60~75℃, and monochlorodifluoromethane was added at an acceleration rate of 0.8~1.5kg / h. The pressure was controlled at 0.3~0.6MPa during the process. A total of monochlorodifluoromethane was added. After the addition was completed, the stirring was continued at the temperature for 0.5~1h. After the reaction was completed, the next step of the reaction was carried out.

[0021] (2) Add the solvent and sodium hydride to the reactor 2 and stir to mix. Set the temperature of the reactor 2 and vertical condenser 1 to 30-50°C and 10-20°C, respectively. Open the valve of the pipeline from the vertical condenser 1 to the hydrogen treatment device and the circulation pump between the reactor 2 and the filler 1. Then, pump the intermediate in the reactor 1 into the reactor 2 at a rate of 1.865-2.812 kg / h for reaction. Continue the reaction for 0.5-1 hour after the addition is completed.

[0022] (3) Then close the valve of the pipeline from vertical condenser 1 to the hydrogen treatment unit and open the valve of the pipeline to the hexafluoropropylene oxide treatment unit. Set the temperatures of the tubular reactor, reactor 3, and vertical condenser 2 to 15-30°C, 15-30°C, and 5-10°C, respectively. Turn on the circulation pump above reactor 3. After preparation, pump the materials in reactor 2 and trifluoroacetyl fluoride raw material tank into the mixer at an acceleration rate of 4.94-5.88 kg / h and 1.096-1.542 kg / h, respectively. Then, pump the materials into the tubular reactor, and then into reactor 3 through the tubular reactor. After the addition is completed, continue the reaction in reactor 3 for 1-1.5 hours. Recover the organic solvent and dimethyl sulfide in the bottom liquid after the reaction and reuse them.

[0023] (4) The target product hexafluoropropylene oxide is finally obtained in the hexafluoropropylene oxide processing device, its purity is tested, and the yield is calculated based on sodium hydride.

[0024] The specific reaction steps are: .

[0025] Compared with the prior art, the present invention has the following beneficial effects: (1) The reaction conditions of the present invention are mild and controllable. At the same time, the synthesis of hexafluoropropylene oxide from trifluoroacetyl fluoride is carried out at a low temperature of 15-30°C, avoiding side reactions caused by high temperature.

[0026] (2) The product of the present invention has high purity and stable yield. By avoiding the mainstream process of oxygen oxidation of hexafluoropropylene, the purity of hexafluoropropylene oxide is ≥99.5% (GC detection) and the yield is 85~92% (calculated as sodium hydride), which is significantly improved compared with the existing process (70~80%).

[0027] (3) The resource recycling of the present invention has a solvent (tetrahydrofuran / dimethyl sulfoxide) and dimethyl sulfide recovery rate of >95%, and the activity remains unchanged after being reused 5 times. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the synthesis device of hexafluoropropylene oxide of the present invention.

[0029] In the figure: 1. Monochlorodifluoromethane raw material tank; 2. Reaction tank 1; 3. Reaction tank 2; 4. Stuffing device 1; 5. Vertical condenser 1; 6. Hydrogen treatment device; 7. Trifluoroacetyl fluoride raw material tank; 8. Mixer; 9. Tubular reactor; 10. Reaction tank 3; 11. Stuffing device 2; 12. Vertical condenser 2; 13. Hexafluoropropylene oxide treatment device. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to specific embodiments.

[0031] like Figure 1 As shown, the synthesis device of hexafluoropropylene oxide described in the present invention includes a reaction tank 2 3 and a reaction tank 3 10. A stuffing device 1 4 is installed on the top of the reaction tank 2 3, and the stuffing device 1 4 is connected to a vertical condenser 1 5. The vertical condenser 1 5 is connected to the hydrogen treatment device 6. A stuffing device 2 11 is provided on the top of the reaction tank 3 10, and the stuffing device 2 11 is connected to a vertical condenser 2 12. The vertical condenser 2 12 is connected to the hexafluoropropylene oxide treatment device 13.

[0032] The chlorodifluoromethane raw material tank 1 is connected to the reaction tank 2, which is connected to the reaction tank 2 3. A stuffing device 4 is installed on the top of the reaction tank 2 3, which is connected to the vertical condenser 5, which is connected to the hydrogen treatment device 6; the reaction tank 2 3 is connected to the mixer 8, which is connected to the trifluoroacetyl fluoride raw material tank 7, which is connected to the tubular reactor 9, which is connected to the reaction tank 3 10. A stuffing device 2 11 is provided on the top of the reaction tank 3 10, which is connected to the vertical condenser 2 12, which is connected to the hexafluoropropylene oxide treatment device 13.

[0033] The working steps of the above device are: 1. Preliminary Preparation and System Replacement Nitrogen replacement and vacuuming: Close all inlet and outlet valves.

[0034] Introduce nitrogen into the entire system to displace and expel air. After the displacement is qualified, the system is pumped into negative pressure (vacuum).

[0035] 2. Preparation of intermediates in reaction tank 2 Adding and mixing: Add the solvent and dimethyl sulfide to the reaction tank 2. Start the agitator of the reaction tank 2 to mix.

[0036] Raise the temperature and add the reactants: Raise the temperature of the mixed system in the reaction tank 2. Start adding chlorodifluoromethane from the chlorodifluoromethane raw material tank 1 to the reaction tank 2.

[0037] Heat preservation and aging: After the addition of chlorodifluoromethane is complete, continue to heat and stir to react. The reaction is complete and the intermediate is generated. Prepare to transfer to reaction tank 23.

[0038] 3. Prepare the alkylmethylene (difluoro) type sulfur ylide intermediate in reaction tank 2 3: Preparation of Reactor 23 (Addition and Setup): Add solvent and sodium hydride to Reactor 23. Start the agitator in Reactor 23 to mix. Set the temperature of Reactor 23. Set the temperature of Vertical Condenser 5.

[0039] Start circulation and exhaust: Turn on the circulation pump between the reaction tank 2 3 and the filler 1 4 to establish the reaction liquid circulation.

[0040] Open the pipeline valve from the vertical condenser 5 to the hydrogen processing device 6 to prepare for discharging hydrogen.

[0041] Addition reaction: the intermediate generated in reaction tank 1-2 is added to reaction tank 2-3.

[0042] The reaction is carried out in the reaction tank 2 (3) to generate hydrogen. The hydrogen is condensed and refluxed through the filler 1 (4) and vertical condenser 1 (5), and the non-condensable gas enters the hydrogen treatment device 6.

[0043] Heat preservation and aging: After the intermediate addition is complete, the reaction is continued. The reaction is completed and the alkylmethylene (difluoro) type sulfur ylide intermediate is generated. Prepare for the next reaction.

[0044] 4. Synthesis of hexafluoropropylene oxide in tubular reactor 9 and reaction tank 3 10: Close the valve from vertical condenser 5 to hydrogen processing device 6.

[0045] Open the valve from vertical condenser 1 (5) to hexafluoropropylene oxide processing unit (13). Set the temperature of tubular reactor 9. Set the temperature of reaction tank 3 (10). Set the temperature of vertical condenser 2 (12) (used to condense the hexafluoropropylene oxide product).

[0046] Turn on the circulation pump above the reaction tank 3 10 (connected to the filler 2 11).

[0047] Mixing and Tubular Reaction: The material in reaction tank 2 (3) (alkylmethylene (difluoro) type sulfur ylide intermediate solution) is pumped into mixer 8. Simultaneously, trifluoroacetyl fluoride from trifluoroacetyl fluoride raw material tank 7 is pumped into mixer 8. After the two materials are mixed in mixer 8, they enter tubular reactor 9 for reaction.

[0048] Reaction and collection in reaction tank 3 10: The material discharged from tubular reactor 9 enters reaction tank 3 10. The reaction continues in reaction tank 3 10. The generated hexafluoropropylene oxide gas (and possible low-boiling substances) rises.

[0049] The gas passes through the second packing device 11 and the second vertical condenser 12, where the hexafluoropropylene oxide is condensed and liquefied. The condensate is collected and flows into the hexafluoropropylene oxide processing unit 13 for further processing (such as distillation, drying, etc.).

[0050] Heat preservation and aging: After the addition of trifluoroacetyl fluoride is completed, continue the reaction in the reaction tank at 310°C to ensure complete reaction.

[0051] 5. Post-processing and recycling Product collection: The hexafluoropropylene oxide processing device 13 finally obtains the product hexafluoropropylene oxide.

[0052] Recovery of solvent and raw materials: After the reaction is completed (mainly in the bottom liquid of reaction tank 1 2 and reaction tank 3 10), the organic solvent and dimethyl sulfide are recovered and reused after treatment.

[0053] Example 1 (1) The system was replaced with nitrogen, and then 8.15 kg of dimethyl sulfoxide solvent and 3.479 kg of dimethyl sulfide were added to the reaction tank 2 under negative pressure and stirred and mixed. The temperature of the mixed system was raised to 60 ° C, and monochlorodifluoromethane was added at an acceleration of 1.5 kg / h. The pressure was controlled within 0.6 MPa during the process. A total of 5.245 kg of monochlorodifluoromethane was added. After the addition was completed, the mixture was kept warm and stirred for 1 hour. After the reaction was completed, the next step of the reaction was carried out.

[0054] (2) Add 8.2 kg of dimethyl sulfoxide solvent and 1.12 kg of sodium hydride to reaction tank 2 (3) and stir to mix. Set the temperatures of reaction tank 2 (3) and vertical condenser 5 to 30°C and 20°C, respectively. Open the valve of the pipeline from vertical condenser 5 to hydrogen treatment device 6 and the circulation pump between reaction tank 2 (3) and filler 4. Then, pump the intermediate in reaction tank 2 into reaction tank 2 (3) at a rate of 2.812 kg / h for reaction. Continue the reaction for 1 hour after the addition is completed.

[0055] (3) The valve of the pipeline from vertical condenser 1 5 to hydrogen treatment unit 6 was then closed, and the valve of the pipeline from vertical condenser 1 5 to hexafluoropropylene oxide treatment unit 13 was opened. The temperatures of tubular reactor 9, reaction tank 3 10, and vertical condenser 2 12 were set to 30°C, 30°C, and 5°C, respectively. The circulation pump above reaction tank 3 10 was turned on. After preparation, the materials in reaction tank 2 3 and trifluoroacetyl fluoride raw material tank 7 were pumped into mixer 8 at an acceleration rate of 5.82 kg / h and 1.383 kg / h, respectively. The materials then entered tubular reactor 9, and then entered reaction tank 3 10. A total of 6.225 kg of trifluoroacetyl fluoride was added. After the addition was complete, the reaction continued in reaction tank 3 10 for 1 hour. The organic solvent and dimethyl sulfide in the bottom liquid after the reaction were recovered and reused.

[0056] (4) In the hexafluoropropylene oxide processing device 13, 6.628 kg of hexafluoropropylene oxide was finally obtained. The obtained hexafluoropropylene oxide was subjected to gas phase analysis, and the purity was 99.59%, and the yield was 85.2% (calculated based on the mol amount of sodium hydride).

[0057] Example 2 (1) The system was replaced with nitrogen, and then negative pressure was drawn to add 7.42 kg of tetrahydrofuran solvent and 3.103 kg of dimethyl sulfide into the reaction tank 2 and stirred and mixed. The temperature of the mixed system was raised to 75 ° C. Monochlorodifluoromethane was added at an acceleration of 0.8 kg / h. The pressure was controlled within 0.3 MPa during the process. A total of 4.399 kg of monochlorodifluoromethane was added. After the addition was completed, the mixture was kept warm and stirred for 0.5 h. After the reaction was completed, the next step of the reaction was carried out.

[0058] (2) Add 7.49 kg of tetrahydrofuran solvent and 1.11 kg of sodium hydride to reaction tank 2 (3) and stir to mix. Set the temperatures of reaction tank 2 (3) and vertical condenser 5 to 50°C and 10°C, respectively. Open the valve of the pipeline from vertical condenser 5 to hydrogen treatment device 6 and the circulation pump between reaction tank 2 (3) and filler 4. Then, pump the intermediate in reaction tank 2 into reaction tank 2 (3) at a rate of 1.865 kg / h for reaction. Continue the reaction for 1 hour after the addition is completed.

[0059] (3) The valve of the pipeline from vertical condenser 1 5 to hydrogen treatment unit 6 was then closed, and the valve of the pipeline from vertical condenser 1 5 to hexafluoropropylene oxide treatment unit 13 was opened. The temperatures of tubular reactor 9, reaction tank 3 10, and vertical condenser 2 12 were set to 15°C, 15°C, and 10°C, respectively. The circulation pump above reaction tank 3 10 was turned on. After preparation, the materials in reaction tank 2 3 and trifluoroacetyl fluoride raw material tank 7 were pumped into mixer 8 at an acceleration rate of 5.88 kg / h and 1.542 kg / h, respectively. The materials then entered tubular reactor 9, and then entered reaction tank 3 10. A total of 6.17 kg of trifluoroacetyl fluoride was added. After the addition was complete, the reaction continued in reaction tank 3 10 for 1.5 hours. The organic solvent and dimethyl sulfide in the bottom liquid after the reaction were recovered and reused.

[0060] (4) In the hexafluoropropylene oxide processing device 13, 6.76 kg of hexafluoropropylene oxide was finally obtained. The obtained hexafluoropropylene oxide was subjected to gas phase analysis, and the purity was 99.5%, and the yield was 87.6% (calculated based on the mol amount of sodium hydride).

[0061] Example 3 (1) The system was replaced with nitrogen, and then 7.53 kg of tetrahydrofuran solvent and 3.304 kg of dimethyl sulfide were added to the reaction tank 2 under negative pressure and stirred and mixed. The temperature of the mixed system was raised to 65 ° C. Monochlorodifluoromethane was added at an acceleration of 1.15 kg / h. The pressure was controlled within 0.45 MPa during the process. A total of 4.399 kg of monochlorodifluoromethane was added. After the addition was completed, the mixture was kept warm and stirred for 0.75 h. After the reaction was completed, the next step of the reaction was carried out.

[0062] (2) Add 7.53 kg of tetrahydrofuran solvent and 1.11 kg of sodium hydride to reaction tank 2 (3) and stir to mix. Set the temperatures of reaction tank 2 (3) and vertical condenser 5 to 45°C and 15°C, respectively. Open the valve of the pipeline from vertical condenser 5 to hydrogen treatment device 6 and the circulation pump between reaction tank 2 (3) and filler 4. Then, pump the intermediate in reaction tank 2 into reaction tank 2 (3) at a rate of 2.233 kg / h for reaction. Continue the reaction for 0.75 h after the addition is completed.

[0063] (3) The valve of the pipeline from vertical condenser 1 to hydrogen treatment unit 6 was then closed, and the valve of the pipeline from vertical condenser 1 to hexafluoropropylene oxide treatment unit 13 was opened. The temperatures of tubular reactor 9, reaction tank 3 10, and vertical condenser 2 12 were set to 20°C, 20°C, and 6°C, respectively. The circulation pump above reaction tank 3 10 was turned on. After preparation, the materials in reaction tank 2 3 and trifluoroacetyl fluoride raw material tank 7 were pumped into mixer 8 at an acceleration rate of 5.394 kg / h and 1.311 kg / h, respectively. The materials then entered tubular reactor 9, and then entered reaction tank 3 10. A total of 5.902 kg of trifluoroacetyl fluoride was added. After the addition was complete, the reaction continued in reaction tank 3 10 for 1.25 hours. The organic solvent and dimethyl sulfide in the bottom liquid after the reaction were recovered and reused.

[0064] (4) In the hexafluoropropylene oxide processing device 13, 7.1 kg of hexafluoropropylene oxide was finally obtained. The obtained hexafluoropropylene oxide was subjected to gas phase analysis, and the purity was 99.7%, and the yield was 92.2% (calculated based on the mol amount of sodium hydride).

[0065] Example 4 (1) The system was replaced with nitrogen, and then 8.17 kg of dimethyl sulfoxide solvent and 3.019 kg of dimethyl sulfide were added to the reaction tank 2 under negative pressure and stirred and mixed. The temperature of the mixed system was raised to 75 ° C. Monochlorodifluoromethane was added at an acceleration of 1.15 kg / h. The pressure was controlled at 0.3 MPa during the process. A total of 4.28 kg of monochlorodifluoromethane was added. After the addition was completed, the mixture was kept warm and stirred for 1 hour. After the reaction was completed, the next step of the reaction was carried out.

[0066] (2) Add 8.15 kg of dimethyl sulfoxide solvent and 1.08 kg of sodium hydride to reaction tank 2 (3) and stir to mix. Set the temperatures of reaction tank 2 (3) and vertical condenser 5 to 45°C and 10°C, respectively. Open the valve of the pipeline from vertical condenser 5 to hydrogen treatment device 6 and the circulation pump between reaction tank 2 (3) and filler 4. Then, pump the intermediate in reaction tank 2 into reaction tank 2 (3) at a rate of 2.062 kg / h for reaction. Continue the reaction for 0.5 h after the addition is completed.

[0067] (3) The valve of the pipeline from vertical condenser 1 to hydrogen treatment unit 6 was then closed, and the valve of the pipeline from vertical condenser 1 to hexafluoropropylene oxide treatment unit 13 was opened. The temperatures of tubular reactor 9, reaction tank 3 10, and vertical condenser 2 12 were set to 25°C, 25°C, and 6°C, respectively. The circulation pump above reaction tank 3 10 was turned on. After preparation, the materials in reaction tank 2 3 and trifluoroacetyl fluoride raw material tank 7 were pumped into mixer 8 at an acceleration rate of 4.94 kg / h and 1.096 kg / h, respectively. The materials then entered tubular reactor 9, and then entered reaction tank 3 10. A total of 5.481 kg of trifluoroacetyl fluoride was added. After the addition was complete, the reaction continued in reaction tank 3 10 for 1 hour. The organic solvent and dimethyl sulfide in the bottom liquid after the reaction were recovered and reused.

[0068] (4) In the hexafluoropropylene oxide processing device 13, 6.787 kg of hexafluoropropylene oxide was finally obtained. The obtained hexafluoropropylene oxide was subjected to gas phase analysis, and the purity was 99.62%, and the yield was 90.5% (calculated based on the mol amount of sodium hydride).

[0069] Comparative Example 1 This comparative example was the same as Example 1, except that the temperature and pressure of the mixing system in step (1) were changed to 35°C and 0.2 MPa, and other preparation conditions were the same. Finally, 1.545 kg of hexafluoropropylene oxide was obtained. The obtained hexafluoropropylene oxide had a purity of 75.2% by gas phase analysis, and a yield of 15% (based on the molar amount of sodium hydride).

[0070] Comparative Example 2 This comparative example was the same as Example 1, except that the reaction temperature in reaction vessel 2 (3) in step (2) was changed to 80°C. Other preparation conditions remained the same. Finally, 2.509 kg of hexafluoropropylene oxide was obtained. The obtained hexafluoropropylene oxide had a purity of 71% according to vapor phase analysis, and a yield of 23% (based on mol of sodium hydride).

[0071] Comparative Example 3 This comparative example was the same as Example 1 except that the mixer 8 and tubular reactor 9 in step (3) were omitted. Other preparation conditions were the same. Finally, 5.108 kg of hexafluoropropylene oxide was obtained. The hexafluoropropylene oxide obtained by vapor phase analysis had a purity of 90%, and a yield of 60% (based on the molar amount of sodium hydride).

[0072] Comparative Example 4 This comparative example was the same as Example 1, except that the temperature of tubular reactor 9 and reaction tank 3 10 in step (3) was changed to 50°C. Other preparation conditions remained the same. Finally, 4.062 kg of hexafluoropropylene oxide was obtained. The obtained hexafluoropropylene oxide had a purity of 82% by vapor phase analysis, and a yield of 43% (based on the molar amount of sodium hydride).

Claims

1. A method for synthesizing hexafluoropropylene oxide, characterized in that: The method comprises the following steps: firstly, dimethyl sulfide and a solvent are mixed and heated to react, and monochlorodifluoromethane is added to obtain an intermediate; then, the intermediate is injected into a sodium hydride solution at 30-50°C to obtain a reaction liquid; finally, trifluoroacetyl fluoride is injected into the reaction liquid to react at 15-30°C; and the obtained reaction liquid is treated to obtain hexafluoropropylene oxide.

2. The method for synthesizing hexafluoropropylene oxide according to claim 1, wherein: The ingredients are prepared according to the following molar ratio: monochlorodifluoromethane: dimethyl sulfide: sodium hydride: trifluoroacetyl fluoride = 1.1-1.3: 1.08-1.2: 1: 1.05-1.

15.

3. The method for synthesizing hexafluoropropylene oxide according to claim 1, wherein: The sodium hydride solution is prepared by dispersing sodium hydride in a solvent, and the solvent is tetrahydrofuran or dimethyl sulfoxide.

4. The method for synthesizing hexafluoropropylene oxide according to claim 1, wherein: The passing acceleration of the chlorodifluoromethane is 0.8-1.5 kg / h.

5. The method for synthesizing hexafluoropropylene oxide according to claim 1, wherein: The passing acceleration of the trifluoroacetyl fluoride is 1.096-1.542 kg / h.

6. The method for synthesizing hexafluoropropylene oxide according to claim 1, wherein: Mix dimethyl sulfide and solvent and heat to 60~75℃ for reaction.

7. The method for synthesizing hexafluoropropylene oxide according to claim 1, wherein: The intermediate is injected into the sodium hydride solution, the temperature in the reaction tank 2 (3) is set to 30~50℃, and the vertical condenser 1 (5) set on the top of the reaction tank 2 (3) is set to 10~20℃.

8. The method for synthesizing hexafluoropropylene oxide according to claim 1, wherein: When trifluoroacetyl fluoride is injected, the temperatures of the tubular reactor (9), the reaction tank three (10), and the vertical condenser two (12) are set to 15~30°C, 15~30°C, and 5~10°C, respectively.

9. Hexafluoropropylene oxide, characterized in that: The hexafluoropropylene oxide is synthesized by the synthesis method of hexafluoropropylene oxide according to any one of claims 1 to 8.

10. A hexafluoropropylene oxide synthesis device according to claim 9, characterized in that: The invention comprises a reaction tank 2 (3), a tubular reactor (9), and a reaction tank 3 (10). A stuffing device 1 (4) is installed on the top of the reaction tank 2 (3), the stuffing device 1 (4) is connected to the vertical condenser 1 (5), the vertical condenser 1 (5) is connected to the hydrogen processing device (6), a stuffing device 2 (11) is installed on the top of the reaction tank 3 (10), the stuffing device 2 (11) is connected to the vertical condenser 2 (12), the vertical condenser 2 (12) is connected to the hexafluoropropylene oxide processing device (13); the reaction tank 2 (3) is connected to the mixer (8), the mixer (8) is connected to the tubular reactor (9), and the tubular reactor (9) is connected to the reaction tank 3 (10).

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