Method and process device for preparing 1, 2, 3, 3, 4, 4-hexafluorocyclobutene

Abstract

The invention relates to a method for preparing 1, 2, 3, 3, 4, 4-hexafluorocyclobutene, which comprises the following steps: introducing chlorotrifluoroethylene into a cyclization reactor, and reacting to generate 1, 2-dichlorohexafluorocyclobutane; the generated 1, 2-dichlorohexafluorocyclobutane is introduced into a first condenser, and the liquid 1, 2-dichlorohexafluorocyclobutane is collected into a collection tank; feeding the 1, 2-dichlorohexafluorocyclobutane in the collecting tank into a dehalogenation reactor through a metering pump, and generating 1, 2, 3, 3, 4, 4-hexafluorocyclobutene under the action of a metal reducing agent and a cosolvent; and introducing the generated 1, 2, 3, 3, 4, 4-hexafluorocyclobutene into a second condenser, removing liquid impurities through condensation, and collecting the residual gas phase 1, 2, 3, 3, 4, 4-hexafluorocyclobutene into a first collection cold trap. Compared with a traditional preparation method, the method has the advantages that the product quality is ensured, and meanwhile, the raw material consumption and energy consumption are effectively reduced by optimizing the process device and method for preparing the 1, 2, 3, 3, 4, 4-hexafluorocyclobutene, so that the product cost is greatly reduced, and the economic benefit is improved.

Description

Technical Field

[0001] The invention relates to the field of organic synthesis, and in particular to a method and a process device for preparing 1,2,3,3,4,4-hexafluorocyclobutene. Background Art

[0002] 1,2,3,3,4,4-Hexafluorocyclobutene is a fluorinated olefin compound with specific chemical properties and application fields and excellent performance. It is used in the etching process in semiconductor manufacturing, cleaning and etching in the manufacturing process of liquid crystal displays, surface treatment and cleaning of plasma, and is also used in the fields of foaming agents and refrigerants. It has high scientific research value.

[0003] The current synthetic route for 1,2,3,3,4,4-hexafluorocyclobutene is:

[0004] Hexachloro-1,3-butadiene is used as raw material and the liquid phase method is adopted. First, fluorine-chlorine exchange is carried out, and then a ring-closing reaction is carried out to produce 1,2,3,3,4,4-hexafluorocyclobutene. This process involves anhydrous hydrogen fluoride and the operation is very dangerous.

[0005] Using hexachloro-1,3-butadiene as raw material, the gas phase catalytic method is used to generate 1,2,3,3,4,4-hexafluorocyclobutene, as well as its dimer and trimer. The polymer has high viscosity, the equipment maintenance is difficult, and the product yield is reduced.

[0006] Using chlorotrifluoroethylene as a raw material, a polymerization inhibitor is added to cyclize the raw material to obtain hexafluorodichlorocyclobutane, and then the chlorine atom is removed by elimination reaction to obtain the target product 1,2,3,3,4,4-hexafluorocyclobutene. The conversion rate of this reaction is low.

[0007] Patent CN115819181A provides a highly selective synthesis method for hexafluorocyclobutene, which uses 1,2-dichlorohexafluorocyclobutane in an ether solvent as a reaction co-solvent and adds a metal reducing agent to prepare a highly selective synthesis method for hexafluorocyclobutene. The method of this application introduces the yield of the product under different co-solvents, different acidities, and different reducing agents in the laboratory. It is a theoretical study and is not suitable for large-scale industrial production.

[0008] Patent US5763703A, in the presence of metal oxide or silicon oxide catalyst, hydrogen is introduced at a temperature of 200-500°C for gas phase reaction to reduce and dechlorinate 1,2-dichlorohexafluorocyclobutane to prepare hexafluorocyclobutene. This process has high reaction temperature, high requirements on equipment, and high equipment cost.

[0009] Patent CN109956847B provides an aqueous phase preparation method for fluorinated cyclobutene, which uses water as a solvent and adds a reaction aid to catalyze the reaction. Since the reduction dehalogenation reaction in the aqueous phase under the action of a metal dehalogenating agent is very slow and has a very low yield, it is not suitable for industrial production.

[0010] In summary, the above-mentioned process routes and contents mentioned in the patents have high product costs, great risks, and low operability. In addition, there is no clear description of how to use trifluorochloroethylene to produce hexafluorocyclobutene, nor is there any description of the synthetic process equipment. Therefore, the present invention provides a process production method and equipment with low production cost and strong operability. Summary of the invention

[0011] The object of the present invention is to provide a method and a process device for preparing 1,2,3,3,4,4-hexafluorocyclobutene, so as to solve the technical problems of high cost, high reaction risk and poor operability of the above-mentioned product.

[0012] To achieve the purpose of the present invention, the specific technical solutions provided by the present invention are as follows:

[0013] A process device for preparing 1,2,3,3,4,4-hexafluorocyclobutene, comprising a cyclization reactor, a first condenser, a collecting tank, a dehalogenation reactor, a second condenser and a first collecting cold trap connected in sequence;

[0014] The top of the cyclization reactor is provided with a cyclization reactor feed port and a cyclization reactor production port;

[0015] The first condenser is provided with a first condenser feed port, a first condenser liquid sampling port and a first condenser gas sampling port;

[0016] The collecting tank is provided with a collecting tank feed port, a collecting tank production port and a collecting tank return port;

[0017] The cyclization reactor is provided with a stirring device, a cyclization reactor feed port, a cyclization reactor production port and a cyclization reactor return port;

[0018] The second condenser is provided with a second condenser feed port, a second condenser liquid sampling port and a second condenser gas sampling port;

[0019] The first collecting cold trap is provided with a first collecting cold trap feed port and a first collecting cold trap vent port;

[0020] The cyclization reactor outlet is connected to the first condenser feed port, the first condenser liquid outlet is connected to the collection tank feed port, the collection tank outlet is connected to the cyclization reactor feed port, the cyclization reactor outlet is connected to the second condenser feed port, and the second condenser gas outlet is connected to the first collection cold trap feed port.

[0021] Preferably, it further comprises a second collecting cold trap, on which a second collecting cold trap feed port and a second collecting cold trap vent port are provided, and the first condenser gas sampling port is connected to the second collecting cold trap feed port.

[0022] Preferably, a metering pump is provided on the pipeline connecting the collection tank production outlet and the cyclization reactor feed inlet, one end of the metering pump is connected to the collection tank production outlet, and the other end is respectively connected to the collection tank return port and the cyclization reactor feed inlet.

[0023] Preferably, the liquid sampling port of the second condenser is connected to the return port of the cyclization reactor.

[0024] The present invention also provides a method for preparing 1,2,3,3,4,4-hexafluorocyclobutene, which is implemented by a process device for preparing 1,2,3,3,4,4-hexafluorocyclobutene, comprising the following steps:

[0025] Chlorotrifluoroethylene is introduced into a reactor to react to generate 1,2-dichlorohexafluorocyclobutane;

[0026] The generated 1,2-dichlorohexafluorocyclobutane undergoes a dehalogenation reaction under the action of a metal reducing agent and a co-solvent to obtain 1,2,3,3,4,4-hexafluorocyclobutene.

[0027] Preferably, the method comprises the following steps:

[0028] S1, passing chlorotrifluoroethylene into a cyclization reactor at a flow rate of 8-10 kg / h, maintaining the temperature of the cyclization reactor at 180-230°C and the pressure at 0.3-0.6 MPa, reacting to generate 1,2-dichlorohexafluorocyclobutane, and the reaction time is 5.5-6.5 hours;

[0029] S2, passing the generated 1,2-dichlorohexafluorocyclobutane into the first condenser, after being condensed into liquid, collecting the liquid 1,2-dichlorohexafluorocyclobutane into a collection tank, the temperature of the collection tank is -20 to -10°C;

[0030] S3, the 1,2-dichlorohexafluorocyclobutane in the collection tank is sent to the dehalogenation reactor through a metering pump, the temperature of the dehalogenation reactor is maintained at 180-230°C, the pressure is 0.3-0.6Mpa, under the action of the metal reducing agent and the co-solvent, the dehalogenation reaction occurs, and the generated 1,2,3,3,4,4-hexafluorocyclobutene, the reaction time is 6-8h;

[0031] S4. The generated 1,2,3,3,4,4-hexafluorocyclobutene is passed into the second condenser. After condensation to remove liquid impurities, the remaining gas phase 1,2,3,3,4,4-hexafluorocyclobutene is collected in the first collection cold trap. The temperature of the first collection cold trap is -20 to -10°C.

[0032] Preferably, in step S2, the condensation temperature of the first condenser is 20-40°C, and the gaseous impurities that are not completely condensed in the first condenser are passed into the second collection cold trap, and the temperature of the second collection cold trap is -20--10°C.

[0033] Preferably, in step S3, a reflux operation of 1,2-dichlorohexafluorocyclobutane is further included, and the 1,2-dichlorohexafluorocyclobutane in the collection tank is refluxed to the collection tank through a metering pump, and the flow rate of 1,2-dichlorohexafluorocyclobutane is controlled to be 5-10 kg / h by the metering pump.

[0034] Preferably, in step S3, the molar ratio of the reacted 1,2-dichlorohexafluorocyclobutane to the metal reducing agent is 1:1-1.2, the amount of the co-solvent added is 60% of the volume of the container, the metal reducing agent is one of zinc powder, iron powder or aluminum powder, and the co-solvent is at least one of alcohols or ethers; the alcohol co-solvent includes methanol, ethanol or isopropanol, and the ether co-solvent includes ethyl ether, methyl ether, propyl ether or isopropyl ether.

[0035] Preferably, in step S4, the condensation temperature of the second condenser is -20°C to 0°C, and the liquid impurities removed by condensation flow back to the dehalogenation reactor.

[0036] The method and process device for preparing 1,2,3,3,4,4-hexafluorocyclobutene of the present invention have the following beneficial effects:

[0037] 1. Compared with the traditional preparation method, the present invention effectively reduces the raw material consumption and energy consumption by optimizing the process equipment and process for preparing 1,2,3,3,4,4-hexafluorocyclobutene while ensuring the product quality, so that the product cost is greatly reduced and the economic benefit is significantly improved.

[0038] 2. The process device and process of the present invention are reasonably designed, easy to operate, and easy to realize automated and continuous production, which provides strong support for the industrial production of 1,2,3,3,4,4-hexafluorocyclobutene. The present invention significantly improves the yield of 1,2,3,3,4,4-hexafluorocyclobutene to 50-60% by accurately controlling the reaction conditions and adopting a safe process design, which is much higher than the 20-30% yield of the traditional preparation method. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1A schematic diagram of a process device for preparing 1,2,3,3,4,4-hexafluorocyclobutene according to the present invention;

[0040] Explanation of the markings in the figure: 1. cyclization reactor; 2. first condenser; 3. collecting tank; 4. dehalogenation reactor; 5. second condenser; 6. first collecting cold trap; 7. second collecting cold trap; 8. metering pump. DETAILED DESCRIPTION

[0041] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation method, structure, characteristics and effects of the present invention are described in detail below in combination with the preferred embodiments.

[0042] Device Embodiment

[0043] like Figure 1 , which is a schematic diagram of a process device for preparing 1,2,3,3,4,4-hexafluorocyclobutene according to the present invention;

[0044] A process device for preparing 1,2,3,3,4,4-hexafluorocyclobutene, comprising a cyclization reactor 1, a first condenser 2, a collecting tank 3, a dehalogenation reactor 4, a second condenser 5 and a first collecting cold trap 6 which are connected in sequence;

[0045] The top of the cyclization reactor 1 is provided with a cyclization reactor feed port and a cyclization reactor production port;

[0046] The first condenser 2 is provided with a first condenser feed port, a first condenser liquid sampling port and a first condenser gas sampling port;

[0047] The collecting tank 3 is provided with a collecting tank feed port, a collecting tank production port and a collecting tank return port;

[0048] The dehalogenation reactor 4 is provided with a stirring device, a dehalogenation reactor feed port, a dehalogenation reactor production port and a dehalogenation reactor return port;

[0049] The second condenser 5 is provided with a second condenser feed port, a second condenser liquid sampling port and a second condenser gas sampling port;

[0050] The first collecting cold trap 6 is provided with a first collecting cold trap feed port and a first collecting cold trap vent port.

[0051] Chlorotrifluoroethylene is introduced into the feed port of the cyclization reactor, and the chlorotrifluoroethylene reacts inside the cyclization reactor 1. After the reaction is completed, the generated 1,2-dichlorohexafluorocyclobutane enters the first condenser 2. At this time, the cyclization reactor outlet is connected to the feed port of the first condenser.

[0052] The generated 1,2-dichlorohexafluorocyclobutane is condensed into liquid inside the first condenser 2 and enters the collecting tank 3. The uncondensed gaseous impurities are discharged into the second collecting cold trap 7. The second collecting cold trap 7 is provided with a second collecting cold trap feed port and a second collecting cold trap vent port. Specifically, the first condenser gas sampling port is connected with the second collecting cold trap feed port to allow the gaseous impurities to be discharged.

[0053] The condensed liquid 1,2-dichlorohexafluorocyclobutane is collected in the collection tank 3, and at this time, the liquid sampling port of the first condenser is connected to the feed port of the collection tank.

[0054] Afterwards, liquid 1,2-dichlorohexafluorocyclobutane is pumped into the dehalogenation reactor 4, a dehalogenation reaction occurs, and 1,2,3,3,4,4-hexafluorocyclobutene is generated. At this time, the collection tank outlet is connected to the dehalogenation reactor feed port. Specifically, a metering pump 8 is arranged on the connecting pipeline between the collection tank 3 and the dehalogenation reactor 4. One end of the metering pump 8 is connected to the collection tank outlet, and the other end is respectively connected to the collection tank return port and the cyclization reactor feed port; the metering pump 8 is connected to the collection tank return port to perform a reflux operation of 1,2-dichlorohexafluorocyclobutane. The reflux operation of the metering pump 8 is for better metering operation, that is, regulating the flow rate of the metering pump 8.

[0055] The 1,2,3,3,4,4-hexafluorocyclobutene generated in the dehalogenation reactor 4 needs to be separated. At this time, the dehalogenation reactor outlet is connected to the second condenser feed port, and the 1,2,3,3,4,4-hexafluorocyclobutene and its impurities are passed into the second condenser 5. After condensation by the second condenser 5, the impurities condensed into liquid are refluxed into the dehalogenation reactor 4. At this time, the second condenser liquid outlet is connected to the cyclization reactor return port, and the uncondensed gas phase 1,2,3,3,4,4-hexafluorocyclobutene and its impurities are passed into the first collection cold trap 6. At this time, the second condenser gas outlet is connected to the first collection cold trap feed port, and the 1,2,3,3,4,4-hexafluorocyclobutene is collected in the first collection cold trap 6 to prepare for subsequent impurity removal operations.

[0056] Method Example 1

[0057] A method for preparing 1,2,3,3,4,4-hexafluorocyclobutene, characterized in that it comprises the following steps:

[0058] S1, introducing chlorotrifluoroethylene into the cyclization reactor 1 at a flow rate of 10 kg / h, maintaining the temperature of the cyclization reactor 1 at 200° C. and the pressure at 0.3-0.6 MPa, reacting to generate 1,2-dichlorohexafluorocyclobutane, and the reaction time is 6 hours;

[0059] S2, the generated 1,2-dichlorohexafluorocyclobutane is passed into the first condenser 2, the condensation temperature of the first condenser 2 is 30°C, after being condensed into liquid, the liquid 1,2-dichlorohexafluorocyclobutane is collected in the collection tank 3, the temperature of the collection tank 3 is -10°C, and the gas phase impurities that are not completely condensed in the first condenser 2 are passed into the second collection cold trap 7, the temperature of the second collection cold trap 7 is -15°C;

[0060] S3, the 1,2-dichlorohexafluorocyclobutane in the collection tank 3 is sent to the dehalogenation reactor 4 through the metering pump 8, and the 1,2-dichlorohexafluorocyclobutane is refluxed by the metering pump 8, and the flow rate of the 1,2-dichlorohexafluorocyclobutane is controlled to be 8 kg / h through the reflux operation;

[0061] 1,2-dichlorohexafluorocyclobutane undergoes a dehalogenation reaction under the action of a metal reducing agent, zinc powder, and a co-solvent, ethanol. The temperature of the dehalogenation reactor 4 is maintained at 200°C, and the pressure is maintained within 0.3-0.6Mpa. The generated 1,2,3,3,4,4-hexafluorocyclobutene has a reaction time of 6 hours.

[0062] The molar ratio of 1,2-dichlorohexafluorocyclobutane to the metal reducing agent is 1:1 to 1.2, and the amount of the co-solvent added is 60% of the volume of the container;

[0063] S4. The generated 1,2,3,3,4,4-hexafluorocyclobutene is passed into the second condenser 5, the condensation temperature of the second condenser 5 is -20°C, the liquid impurities removed by condensation are refluxed into the dehalogenation reactor 4, and the remaining gas phase 1,2,3,3,4,4-hexafluorocyclobutene is collected into the first collection cold trap 6, and the temperature of the first collection cold trap 6 is -20°C.

[0064] The conversion rate of producing hexafluorocyclobutene using chlorotrifluoroethylene is 100%, the selectivity is 60%, and the yield is 60%.

[0065] Method Example 2

[0066] A method for preparing 1,2,3,3,4,4-hexafluorocyclobutene, characterized in that it comprises the following steps:

[0067] S1, introducing chlorotrifluoroethylene into the cyclization reactor 1 at a flow rate of 10 kg / h, maintaining the temperature of the cyclization reactor 1 at 180°C and the pressure at 0.3-0.6 MPa, reacting to generate 1,2-dichlorohexafluorocyclobutane, and the reaction time is 6.5 hours;

[0068] S2, passing the generated 1,2-dichlorohexafluorocyclobutane into the first condenser 2, the condensation temperature of the first condenser 2 is 40°C, after condensing into liquid, the liquid 1,2-dichlorohexafluorocyclobutane is collected into the collection tank 3, the temperature of the collection tank 3 is -15°C, and the gas phase impurities that are not completely condensed in the first condenser 2 are passed into the second collection cold trap 7, the temperature of the second collection cold trap 7 is -20°C;

[0069] S3, the 1,2-dichlorohexafluorocyclobutane in the collection tank 3 is sent to the dehalogenation reactor 4 through the metering pump 8, and the 1,2-dichlorohexafluorocyclobutane is refluxed by the metering pump 8, and the flow rate of the 1,2-dichlorohexafluorocyclobutane is controlled to be 10 kg / h by the reflux operation;

[0070] 1,2-dichlorohexafluorocyclobutane undergoes a dehalogenation reaction under the action of a metal reducing agent, zinc powder, and a co-solvent, ethanol. The temperature of the dehalogenation reactor 4 is maintained at 180°C, and the pressure is maintained within 0.3-0.6Mpa. The generated 1,2,3,3,4,4-hexafluorocyclobutene has a reaction time of 7h.

[0071] The molar ratio of 1,2-dichlorohexafluorocyclobutane to the metal reducing agent is 1:1 to 1.2, and the amount of the co-solvent added is 60% of the volume of the container;

[0072] S4. The generated 1,2,3,3,4,4-hexafluorocyclobutene is passed into the second condenser 5, the condensation temperature of the second condenser 5 is -10°C, the liquid impurities removed by condensation are refluxed into the dehalogenation reactor 4, and the remaining gas phase 1,2,3,3,4,4-hexafluorocyclobutene is collected into the first collection cold trap 6, and the temperature of the first collection cold trap 6 is -10°C.

[0073] The conversion rate of producing hexafluorocyclobutene using chlorotrifluoroethylene is 100%, the selectivity is 53%, and the yield is 53%.

[0074] Method Example 3

[0075] A method for preparing 1,2,3,3,4,4-hexafluorocyclobutene, characterized in that it comprises the following steps:

[0076] S1, introducing chlorotrifluoroethylene into the cyclization reactor 1 at a flow rate of 10 kg / h, maintaining the temperature of the cyclization reactor 1 at 230°C and the pressure at 0.3-0.6 MPa, reacting to generate 1,2-dichlorohexafluorocyclobutane, and the reaction time is 5.5 hours;

[0077] S2, passing the generated 1,2-dichlorohexafluorocyclobutane into the first condenser 2, the condensation temperature of the first condenser 2 is 20°C, after condensing into liquid, the liquid 1,2-dichlorohexafluorocyclobutane is collected into the collection tank 3, the temperature of the collection tank 3 is -20°C, and the gas phase impurities that are not completely condensed in the first condenser 2 are passed into the second collection cold trap 7, the temperature of the second collection cold trap 7 is -20°C;

[0078] S3, the 1,2-dichlorohexafluorocyclobutane in the collection tank 3 is sent to the dehalogenation reactor 4 through the metering pump 8, and the 1,2-dichlorohexafluorocyclobutane is refluxed by the metering pump 8, and the flow rate of the 1,2-dichlorohexafluorocyclobutane is controlled to be 6 kg / h by the reflux operation;

[0079] 1,2-dichlorohexafluorocyclobutane undergoes a dehalogenation reaction under the action of a metal reducing agent, zinc powder, and a co-solvent, ethanol. The temperature of the dehalogenation reactor 4 is maintained at 230°C, and the pressure is maintained within 0.3-0.6Mpa. The generated 1,2,3,3,4,4-hexafluorocyclobutene has a reaction time of 8h.

[0080] The molar ratio of 1,2-dichlorohexafluorocyclobutane to the metal reducing agent is 1:1 to 1.2, and the amount of the co-solvent added is 60% of the volume of the container;

[0081] S4. The generated 1,2,3,3,4,4-hexafluorocyclobutene is passed into the second condenser 5, the condensation temperature of the second condenser 5 is 0°C, the liquid impurities removed by condensation are refluxed into the dehalogenation reactor 4, and the remaining gas phase 1,2,3,3,4,4-hexafluorocyclobutene is collected into the first collection cold trap 6, and the temperature of the first collection cold trap 6 is -20°C.

[0082] The conversion rate of producing hexafluorocyclobutene using chlorotrifluoroethylene is 100%, the selectivity is 58%, and the yield is 58%.

[0083] Compared with the traditional preparation method, the present invention effectively reduces raw material consumption and energy consumption by optimizing the process equipment and process for preparing 1,2,3,3,4,4-hexafluorocyclobutene while ensuring product quality, thereby significantly reducing product costs and significantly improving economic benefits.

[0084] The process device and process of the invention are reasonably designed, easy to operate, and easy to realize automated and continuous production, which provides strong support for the industrial production of 1,2,3,3,4,4-hexafluorocyclobutene. The invention significantly improves the yield of 1,2,3,3,4,4-hexafluorocyclobutene to 50-60% by precisely controlling the reaction conditions and adopting a safe process design, which is much higher than the traditional preparation method.

[0085] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A process for preparing 1,2,3,3,4,4-hexafluorocyclobutene, characterized in that: It comprises a cyclization reactor, a first condenser, a collecting tank, a dehalogenation reactor, a second condenser and a first collecting cold trap which are connected in sequence; The top of the cyclization reactor is provided with a cyclization reactor feed port and a cyclization reactor production port; The first condenser is provided with a first condenser feed port, a first condenser liquid sampling port and a first condenser gas sampling port; The collecting tank is provided with a collecting tank feed port, a collecting tank production port and a collecting tank return port; The cyclization reactor is provided with a stirring device, a cyclization reactor feed port, a cyclization reactor production port and a cyclization reactor return port; The second condenser is provided with a second condenser feed port, a second condenser liquid sampling port and a second condenser gas sampling port; The first collecting cold trap is provided with a first collecting cold trap feed port and a first collecting cold trap vent port; The cyclization reactor outlet is connected to the first condenser feed port, the first condenser liquid outlet is connected to the collection tank feed port, the collection tank outlet is connected to the cyclization reactor feed port, the cyclization reactor outlet is connected to the second condenser feed port, and the second condenser gas outlet is connected to the collection cold trap feed port.

2. A process for preparing 1,2,3,3,4,4-hexafluorocyclobutene according to claim 1, characterized in that: It also includes a second collecting cold trap, on which a second collecting cold trap feed port and a second collecting cold trap vent port are provided, and the first condenser gas sampling port is connected to the second collecting cold trap feed port.

3. A process for preparing 1,2,3,3,4,4-hexafluorocyclobutene according to claim 1, characterized in that: A metering pump is arranged on the pipeline connecting the collection tank outlet and the cyclization reactor feed port. One end of the metering pump is connected to the collection tank outlet, and the other end is respectively connected to the collection tank return port and the cyclization reactor feed port.

4. A process for preparing 1,2,3,3,4,4-hexafluorocyclobutene according to claim 1, characterized in that: The liquid sampling port of the second condenser is communicated with the return port of the cyclization reactor.

5. A method for preparing 1,2,3,3,4,4-hexafluorocyclobutene, using a process device for preparing 1,2,3,3,4,4-hexafluorocyclobutene according to any one of claims 1 to 4, characterized in that: The following steps are involved: Chlorotrifluoroethylene is introduced into a reactor to react to generate 1,2-dichlorohexafluorocyclobutane; The generated 1,2-dichlorohexafluorocyclobutane undergoes a dehalogenation reaction under the action of a metal reducing agent and a co-solvent to obtain 1,2,3,3,4,4-hexafluorocyclobutene.

6. A method for preparing 1,2,3,3,4,4-hexafluorocyclobutene according to claim 5, characterized in that: The following steps are involved: S1, passing chlorotrifluoroethylene into a cyclization reactor at a flow rate of 8-10 kg / h, maintaining the temperature of the cyclization reactor at 180-230°C and the pressure at 0.3-0.6 MPa, reacting to generate 1,2-dichlorohexafluorocyclobutane, and the reaction time is 5.5-6.5 hours; S2, passing the generated 1,2-dichlorohexafluorocyclobutane into the first condenser, after being condensed into liquid, collecting the liquid 1,2-dichlorohexafluorocyclobutane into a collection tank, the temperature of the collection tank is -20 to -10°C; S3, the 1,2-dichlorohexafluorocyclobutane in the collection tank is sent to the dehalogenation reactor through a metering pump, the temperature of the dehalogenation reactor is maintained at 180-230°C, the pressure is 0.3-0.6Mpa, under the action of the metal reducing agent and the co-solvent, the dehalogenation reaction occurs, and the generated 1,2,3,3,4,4-hexafluorocyclobutene, the reaction time is 6-8h; S4. The generated 1,2,3,3,4,4-hexafluorocyclobutene is passed into the second condenser. After condensation to remove liquid impurities, the remaining gas phase 1,2,3,3,4,4-hexafluorocyclobutene is collected in the first collection cold trap. The temperature of the first collection cold trap is -20 to -10°C.

7. A method for preparing 1,2,3,3,4,4-hexafluorocyclobutene according to claim 6, characterized in that: In step S2, the condensation temperature of the first condenser is 20-40°C. In the first condenser, the gaseous impurities that are not completely condensed are passed into the second collection cold trap. The temperature of the second collection cold trap is -20--10°C.

8. A method for preparing 1,2,3,3,4,4-hexafluorocyclobutene according to claim 6, characterized in that: In step S3, a reflux operation of 1,2-dichlorohexafluorocyclobutane is also included. The 1,2-dichlorohexafluorocyclobutane in the collection tank is refluxed to the collection tank through a metering pump, and the flow rate of 1,2-dichlorohexafluorocyclobutane is controlled to be 5-10 kg / h by the metering pump.

9. A method for preparing 1,2,3,3,4,4-hexafluorocyclobutene according to claim 6, characterized in that: In step S3, the molar ratio of the reacted 1,2-dichlorohexafluorocyclobutane to the metal reducing agent is 1:1-1.2, the amount of the solvent added is 60% of the volume of the container, the metal reducing agent is one of zinc powder, iron powder or aluminum powder, and the solvent is at least one of alcohols or ethers; the alcohol solvent includes methanol, ethanol or isopropanol, and the ether solvent includes ethyl ether, methyl ether, propyl ether or isopropyl ether.

10. A method for preparing 1,2,3,3,4,4-hexafluorocyclobutene according to claim 6, characterized in that: In step S4, the condensation temperature of the second condenser is -20°C to 0°C, and the liquid impurities removed by condensation flow back to the dehalogenation reactor.

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