Preparation method of perfluorobutyl sulfonyl fluoride

Abstract

The invention discloses a preparation method of perfluorobutanesulfonyl fluoride, which comprises the following steps: introducing fluorine gas and inert gas into a reaction container, and adding butanesulfonyl chloride into the reaction container; butyl sulfonyl chloride and fluorine gas are subjected to a fluorination reaction under the condition of inert gas dilution, the reaction temperature is-20 DEG C to 80 DEG C, the reaction pressure is normal pressure, the reaction time is 2-14 hours, perfluorobutyl sulfonyl fluoride is generated, and hydrogen fluoride gas generated in the fluorination reaction is absorbed. According to the invention, fluorine gas can be diluted by adding inert gas, so that the reaction rate is controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical engineering, and more specifically, to a preparation method of perfluorobutanesulfonyl fluoride. Background Art

[0002] Perfluorobutanesulfonyl fluoride is a perfluoride, which is a liquid at room temperature and is mainly used for synthesizing fluorocarbon surfactants, fluorine-containing pesticides, dyes, polycarbonate processing dispersants, etc. It is also an antibacterial synergist, which enhances the antibacterial effect when combined with sulfonamides and is also used for avian coccidiosis infection and intestinal bacterial infection. The existing preparation method uses electrolysis, but the preparation efficiency of electrolysis is low and cannot meet the corresponding requirements when a small amount of perfluorobutanesulfonyl fluoride needs to be prepared quickly for use. Summary of the Invention

[0003] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art and provide a preparation method of perfluorobutanesulfonyl fluoride.

[0004] To achieve the above purpose, the present invention adopts the following technical solutions:

[0005] The present invention discloses a preparation method of perfluorobutanesulfonyl fluoride, which includes the following steps:

[0006] Step 1: Add butanesulfonyl chloride into a reaction vessel, and then introduce fluorine gas. The reaction temperature is -40°C to 0°C to generate butanesulfonyl fluoride;

[0007] Step 2: Add butanesulfonyl fluoride into a reaction kettle, add a catalyst, and introduce a mixed gas of fluorine gas and an inert gas to generate perfluorobutanesulfonyl fluoride;

[0008] Step 3: Absorb the generated hydrogen fluoride gas.

[0009] Further, in Step 2, the volume ratio of fluorine gas to the inert gas is 1:1 to 1:8.

[0010] Further, in Step 2, the inert gas is nitrogen or argon.

[0011] Further, in Step 1, the reaction temperature is -20°C to 0°C.

[0012] Further, in Step 2, a solvent is added into the reaction kettle, and the reaction is carried out in the solvent. The solvent is perfluorocycloalkane, and the volume ratio of the solvent to butanesulfonyl fluoride is 6:1 to 15:1.

[0013] Further, in Step 2, a hydrogen fluoride scavenger is added into the reaction kettle to absorb the generated hydrogen fluoride gas, and the hydrogen fluoride scavenger is potassium fluoride.

[0014] Further, the perfluorobutanesulfonyl fluoride obtained in Step 2 is separated by distillation to obtain purified perfluorobutanesulfonyl fluoride. The distillation temperature is 80°C - 150°C, and the pressure is 10 - 100 kPa.

[0015] The beneficial effects of the present invention are as follows: By adding an inert gas to dilute fluorine gas, the reaction rate is controlled to avoid side reactions caused by intense heat release, and the yield and purity of the target product perfluorobutanesulfonyl fluoride are significantly improved; hydrogen fluoride generated in the reaction is absorbed, reducing the emission of hydrogen fluoride and environmental pollution. Description of the Drawings

[0016] Figure 1 It is a schematic structural diagram of a gas absorption device in this embodiment;

[0017] Figure 2 It is a schematic structural diagram of a liquid spraying mechanism in this embodiment;

[0018] Figure 3 is Figure 1 an enlarged schematic diagram of part A in

[0019] Figure 4 It is a sectional view of a partition sleeve in this embodiment;

[0020] Figure 5 It is a top view of a lower rotating seat in this embodiment.

[0021] Reference numerals: 1, absorption tower; 2, intake pipe; 3, first partition; 4, second partition; 5, partition cylinder; 6, intake hole; 7, first packing area; 8, second packing area; 9, first air outlet; 10, second air outlet; 11, partition sleeve; 12, exhaust opening; 13, liquid spraying mechanism; 14, third partition; 15, diversion plate; 16, central hole; 17, diversion pipe; 18, liquid collector; 19, overflow pipe; 20, liquid extraction pipe; 21, connecting pipe; 22, purification tower; 23, discharge pipe; 24, fourth partition; 25, aeration head; 26, intake end; 27, liquid supply ring; 28, liquid supply pipe; 29, reduced-diameter pipe; 30, communication pipe; 31, liquid outlet pipe; 32, cover plate; 33, nozzle; 34, upper rotating seat; 35, lower rotating seat; 36, annular groove; 37, sealing plate; 38, exhaust hole; 39, fixing block; 40, guiding block; 41, spring; 42, limiting block; 43, communication hole. Detailed Embodiments

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0023] A method for preparing perfluorobutanesulfonyl fluoride, comprising the following steps:

[0024] Add butanesulfonyl chloride to a reaction vessel, and then introduce fluorine gas. The reaction temperature is -40°C to 0°C, preferably -20°C to 0°C, to produce butanesulfonyl fluoride.

[0025] Add the produced butanesulfonyl fluoride to a reaction kettle, add a catalyst such as cobalt trifluoride, and slowly introduce a mixed gas of fluorine gas and an inert gas. The volume ratio of fluorine gas to the inert gas is 1:1 to 1:8. The inert gas is nitrogen or argon.

[0026] The reaction temperature is 200 - 350°C, and it is heated to the target temperature at a rate of 5 - 10°C / min. The reaction pressure is atmospheric pressure. The molar ratio of cobalt trifluoride to the substrate is 1:1 to 2:1.

[0027] The reaction occurs under the condition of being diluted by an inert gas to produce perfluorobutanesulfonyl fluoride; after the reaction is completed, it is cooled to room temperature, and the hydrogen fluoride gas in the tail gas generated by the reaction is absorbed.

[0028] Perfluorobutanesulfonyl fluoride is separated by distillation to obtain purified perfluorobutanesulfonyl fluoride.

[0029] Add a solvent to the reaction vessel of butanesulfonyl fluoride, and the reaction is carried out in the solvent. The solvent is perfluorocycloalkane or perfluorohexane, and the volume ratio of the solvent to butanesulfonyl fluoride is 6:1 to 15:1.

[0030] Absorb the hydrogen fluoride gas by connecting a gas absorption device in series after the reaction kettle, and the absorption treatment of the hydrogen fluoride gas is carried out in the gas absorption device.

[0031] Such as Figure 1 、 Figure 3 、 Figure 4As shown in the figure, the gas absorption device includes an absorption tower 1. The top of the absorption tower 1 is connected to an inlet pipe 2. A first partition 3 is installed near the inlet pipe 2 inside the absorption tower 1. A second partition 4 is installed near the middle position inside the absorption tower 1. The outer peripheries of the first partition 3 and the second partition 4 are connected to the inner wall of the absorption tower 1. A partition cylinder 5 is connected between the first partition 3 and the second partition 4. The partition cylinder 5 divides the area surrounded by the first partition 3, the second partition 4, and the absorption tower 1 into a first packing area 7 and a second packing area 8, and the first packing area 7 and the second packing area 8 are filled with adsorption materials. A number of air inlet holes 6 are opened on the first partition 3, and the air inlet holes 6 communicate the partition cylinder 5, the second packing area 8 with the inside of the absorption tower 1. An air outlet hole 9 and an air outlet hole 10 are opened on the second partition 4. The air outlet hole 9 communicates with the first packing area 7, and the air outlet hole 10 communicates with the second packing area 8. A third partition 14 is installed at a position below the second partition 4 inside the absorption tower 1. The outer periphery of the third partition 14 is connected to the inner wall of the absorption tower 1. A partition sleeve 11 is installed between the second partition 4 and the third partition 14. A number of exhaust openings 12 are opened on the outer periphery of the partition sleeve 11, and the exhaust openings 12 communicate the inside and outside of the partition sleeve 11. Two of the side edges of the exhaust openings 12 are parallel, and one of the side edges is tangent to the inner wall of the partition sleeve 11. The opening directions of the air outlet hole 10 and the exhaust openings 12 are perpendicular to each other. A liquid outlet hole is opened on the third partition 14, and the position of the liquid outlet hole corresponds to the outside of the partition sleeve 11. A liquid spraying mechanism 13 is installed on the side wall of the absorption tower 1, and the liquid outlet of the liquid spraying mechanism 13 is located between the second partition 4 and the third partition 14.

[0032] The gas generated after the fluorination reaction enters the absorption tower 1 through the inlet pipe 2, and then enters the first packing area 7 and the second packing area 8 respectively under the guidance of the air inlet holes 6 on the first partition 3. The gas entering the first packing area 7 enters the partition sleeve 11 through the air outlet hole 9, and then is discharged from the exhaust openings 12 on the peripheral wall of the partition sleeve 11. The gas entering the second packing area 8 is discharged from the air outlet hole 10. The air flows discharged from the exhaust openings 12 and the air outlet hole 10 collide to generate turbulence, the gas will decelerate, and will disperse between the second partition 4 and the third partition 14. Since the liquid outlet of the liquid spraying mechanism 13 is located between the second partition 4 and the third partition 14, the absorption liquid atomized and sprayed in the liquid spraying mechanism 13 can fully contact with the gas, so that hydrogen fluoride is fully absorbed by the absorption liquid.

[0033] A liquid collector 18 is arranged at the bottom of the absorption tower 1. A flow guiding disc 15 is arranged below the third partition 14. A central hole 16 is opened at the middle position of the flow guiding disc 15. A number of flow guiding pipes 17 are connected below the third partition 14. The flow guiding pipes 17 are located in the central hole 16, and the outer walls of some of the flow guiding pipes 17 are in contact with the inner wall of the central hole 16. The lower ends of the flow guiding pipes 17 extend into the liquid collector 18. An overflow pipe 19 is also arranged at the bottom of the absorption tower 1. One end of the overflow pipe 19 extends into the liquid collector 18, and the other end of the overflow pipe 19 passes through the absorption tower 1 and is provided with a regulating valve on the part of the overflow pipe 19 located outside the absorption tower 1.

[0034] The absorption liquid flows down from the liquid outlet hole on the partition plate three 14 and is guided by the diversion disk 15 to the central hole 16 in the middle. After the absorption liquid contacts the diversion pipe 17, it can flow down along the diversion pipe 17 and accurately fall into the liquid collector 18 below for collection. After the amount of the absorption liquid in the liquid collector 18 increases, it can overflow from the overflow pipe 19, so that the amount of the absorption liquid in the liquid collector 18 is maintained within a certain range.

[0035] As Figure 2 shown, the liquid spraying mechanism 13 includes a liquid supply ring 27. A liquid supply pipe 28 is connected to the liquid supply ring 27. A plurality of reduced-diameter pipes 29 are connected to the inner side of the liquid supply ring 27. The other end of the reduced-diameter pipe 29 is connected to a communicating pipe 30. The diameter of the reduced-diameter pipe 29 gradually decreases from the end close to the liquid supply ring 27 to the end close to the communicating pipe 30. The other end of the communicating pipe 30 is connected to a liquid outlet pipe 31. The other end of the liquid outlet pipe 31 extends into the absorption tower 1 and is provided with a cover plate 32. A plurality of nozzles 33 are opened on the cover plate 32. A liquid extraction pipe 20 is connected to the lower part of the communicating pipe 30. The other end of the liquid extraction pipe 20 is located in the liquid collector 18. The absorption liquid is pumped from the liquid supply pipe 28 into the liquid supply ring 27 by an external pump. The absorption liquid then flows along the reduced-diameter pipe 29, the communicating pipe 30, and the liquid outlet pipe 31, and finally is sprayed out in an atomized state through the nozzles 33 on the cover plate 32 to fully contact with the gas for absorption. Since the diameter of the reduced-diameter pipe 29 gradually decreases, suction will be generated when the absorption liquid passes through the communicating pipe 30, so that the absorption liquid in the liquid collector 18 is sucked in through the liquid extraction pipe 20. These absorption liquids are sprayed out together with the new absorption liquid, so that the absorption liquid can be fully utilized. The mixed absorption liquid enters the liquid collector 18, and part of the absorption liquid overflows from the overflow pipe 19, so that the total amount of the absorption liquid is maintained within a certain range, and the absorption liquid is in dynamic update and can maintain good gas absorption capacity.

[0036] As Figure 3 、 Figure 5As shown in the figure, the partition sleeve 11 is rotatably arranged between the first air outlet 9 and the third partition 14. An upper rotating seat 34 is installed at the lower part of the first air outlet 9, and a lower rotating seat 35 is installed at the upper part of the third partition 14. The partition sleeve 11 is located between the upper rotating seat 34 and the lower rotating seat 35. An annular groove 36 is formed at the upper part of the lower rotating seat 35, and a fixing block 39 is installed in the annular groove 36. A guiding block 40 is connected to the lower part of the partition sleeve 11, and a spring 41 is connected between the guiding block 40 and the fixing block 39. The spring 41 is arranged along the arc of the annular groove 36. A sealing plate 37 is installed at the lower part inside the partition sleeve 11. A plurality of exhaust holes 38 are formed in the sealing plate 37, and the bottom of the sealing plate 37 is attached to the upper end surface of the third partition 14. A communication hole 43 matching the exhaust holes 38 is formed in the third partition 14. The diversion pipe 17 is of a hollow structure, and the upper end of the diversion pipe 17 is communicated with the communication hole 43. The height of the lower end of the diversion pipe 17 is lower than the height of the upper end of the overflow pipe 19. In the initial state, the exhaust holes 38 and the communication holes 43 are staggered, and the gas entering the partition sleeve 11 is discharged from the exhaust opening 12. When the amount of gas introduced increases, the gas entering between the second partition 4 and the third partition 14 will increase, resulting in the absorption liquid not being absorbed in time. At this time, due to the increase in the amount of gas passing through at the same time, the speed of the gas discharged from the exhaust opening 12 increases, which will drive the partition sleeve 11 to rotate, so that the exhaust holes 38 and the communication holes 43 are communicated. Part of the gas in the partition sleeve 11 can be directly discharged through the exhaust holes 38, the communication holes 43 and the diversion pipe 17, and directly enters the absorption liquid in the liquid collector 18 for absorption, so as to maintain a high absorption rate when the amount of gas introduced increases.

[0037] A limiting block 42 is also arranged in the nozzle 33, and the guiding block 40 is installed between the fixing block 39 and the limiting block 42. The limiting block 42 is used to limit the rotation limit position of the guiding block 40, and blocks the guiding block 40 when the exhaust holes 38 and the communication holes 43 are aligned, so that the gas has the maximum passing amount.

[0038] As Figure 1 shown in the figure, the gas absorption device further includes a purification tower 22. The top end of the purification tower 22 is connected with a discharge pipe 23. A fourth partition 24 is arranged inside the purification tower 22. An absorption liquid is arranged at the position above the fourth partition 24 inside the purification tower 22. An aeration head 25 is installed at the middle position of the fourth partition 24. The gas outlet end of the aeration head 25 is located in the absorption liquid, and the gas inlet end 26 of the aeration head 25 penetrates through the fourth partition 24. A connecting pipe 21 is connected between the purification tower 22 and the absorption tower 1. One end of the connecting pipe 21 connected to the absorption tower 1 is located below the diversion disk 15, and one end of the connecting pipe 21 connected to the purification tower 22 is located below the fourth partition 24. The gas in the absorption tower 1 can enter the purification tower 22 through the connecting pipe 21. The gas enters the aeration head 25 from the gas inlet end 26, and the gas is divided into small bubbles through the aeration head 25 and enters the absorption liquid. The absorption liquid can absorb the gas again to ensure that the gas discharged from the discharge pipe 23 does not contain hydrogen fluoride as much as possible.

[0039] A concentration monitor can be installed at the exhaust pipe 23 to monitor the content of hydrogen fluoride in the discharged gas.

[0040] Another method is to directly add a hydrogen fluoride scavenger to the reaction vessel to absorb the hydrogen fluoride gas generated by the reaction. The hydrogen fluoride scavenger is potassium fluoride.

[0041] After the fluorination reaction is completed, separation is carried out by distillation to obtain purified perfluorobutanesulfonyl fluoride, where the distillation temperature is 80°C - 150°C and the pressure is 10 - 100 kPa.

[0042] The above are only the preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements should also be regarded as within the protection scope of the present invention.

Claims

1. A method for preparing perfluorobutylsulfonyl fluoride, characterized in that: The following steps are involved: Step 1: Add butanesulfonyl chloride into a reaction vessel, then introduce fluorine gas, and the reaction temperature is -40°C to 0°C to generate butanesulfonyl fluoride; Step 2: adding butylsulfonyl fluoride into a reaction kettle, adding a catalyst, introducing a mixed gas of fluorine gas and an inert gas, and reacting to generate perfluorobutylsulfonyl fluoride; Step 3: Absorbing the generated hydrogen fluoride gas.

2. A method for preparing perfluorobutylsulfonyl fluoride according to claim 1, characterized in that: In step 2, the volume ratio of fluorine gas to inert gas is 1:1 to 1:

8.

3. A method for preparing perfluorobutylsulfonyl fluoride according to claim 1, characterized in that: In step 2, the inert gas is nitrogen or argon.

4. A method for preparing perfluorobutylsulfonyl fluoride according to claim 1, characterized in that: In step 1, the reaction temperature is -20°C to 0°C.

5. A method for preparing perfluorobutylsulfonyl fluoride according to claim 1, characterized in that: In step 2, a solvent is added to the reaction kettle, and the reaction is carried out in the solvent. The solvent is perfluorocycloalkane, and the volume ratio of the solvent to butylsulfonyl fluoride is 6:1 to 15:

1.

6. A method for preparing perfluorobutylsulfonyl fluoride according to claim 5, characterized in that: In step 2, a hydrogen fluoride scavenger is added into the reactor to absorb the hydrogen fluoride gas generated by the reaction, and the hydrogen fluoride scavenger is potassium fluoride.

7. A method for preparing perfluorobutylsulfonyl fluoride according to claim 1, characterized in that: The perfluorobutylsulfonyl fluoride obtained in step 2 is separated by distillation to obtain purified perfluorobutylsulfonyl fluoride.

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