Process for preparing perfluorinated sulfonyl fluoride vinyl ether

Abstract

The present invention provides a method for economically and industrially producing perfluorinated sulfonyl fluoride vinyl ether (PSEPVE) in high yield using a high boiling point solvent.

Description

Technology Field

[0001] The present invention relates to a method for economically and industrially producing perfluorinated sulfonyl fluoride vinyl ether (PSEPVE) in high yield using a high boiling point solvent. Background Technology

[0002] Recently, interest in and demand for fuel cells, an eco-friendly energy source, have been growing. A fuel cell is an energy conversion system that directly converts the chemical energy contained in hydrogen or hydrocarbon fuels into electrical energy through an electrochemical catalytic reaction.

[0003] The core material of a fuel cell is the MEA (membrane electrode assembly), which consists of a cathode, an anode, and a polymer electrolyte membrane (PEM). A representative material for the polymer electrolyte membrane (PEM) is Nafion from DuPont, USA. ® Examples include perfluorinated sulfonic acid ionomers (PFSA).

[0004] PFSA consists of a polytetrafluoroethylene (PTFE) main chain with excellent chemical durability and a side chain having a sulfate group (-SO3H) with proton conductivity at the end. PFSA polymers are typically prepared by the free radical copolymerization of tetrafluoroethylene (TFE) and a perfluorinated sulfonyl fluoride vinyl ether (PSEPVE) monomer of Formula 1 below.

[0005] [Chemical Formula 1]

[0006]

[0007] In the above formula,

[0008] n is an integer from 0 to 2.

[0010] It is known that the perfluorinated sulfonyl fluoride vinyl ether (PSEPVE) of the above chemical formula 1 can typically be prepared from a compound represented by chemical formula 2 via a salt represented by chemical formula 3.

[0011] [Chemical Formula 2]

[0012]

[0013] [Chemical Formula 3]

[0014]

[0015] In the above formula,

[0016] n is an integer from 0 to 2, and

[0017] M is an alkali metal.

[0019] Specifically, U.S. Patent No. 3,821,297 describes the preparation of perfluorinated sulfonyl fluoride vinyl ether (PSEPVE) by adding sodium carbonate to a reaction vessel and introducing perfluorinated sulfonyl fluoride acetyl fluoride while heating to 165°C and stirring vigorously. It further describes obtaining the crude product of the prepared PSEPVE by continuously passing it through a liquid-liquid separator and purifying it. However, such a reaction in a solid state is inefficient and entails many difficulties, particularly in industrial production. Additionally, there was a problem with a low yield of 66.9% due to many side reactions.

[0020] Attempts were made to produce perfluorinated sulfonyl fluoride vinyl ether (PSEPVE) in a liquid state using a reaction solvent, but there was a problem in that side reactions proceeded and a large amount of impurities were generated when a reaction solvent was used. Prior art literature

[0021] U.S. Patent No. 3,821,297 The problem to be solved

[0022] The present invention is intended to solve the above-mentioned problems, and one objective of the present invention is to provide a method for producing perfluorinated sulfonyl fluoride vinyl ether (PSEPVE) in high yield by using a high-boiling point solvent to achieve uniform heat transfer and ease of stirring while suppressing side reactions.

[0023] Another objective of the present invention is to provide a method for manufacturing perfluorinated sulfonyl fluoride vinyl ether (PSEPVE) that is easy to purify and industrially produceable. means of solving the problem

[0024] One embodiment of the present invention relates to a method for producing a perfluorinated sulfonyl fluoride vinyl ether (PSEPVE) of the following chemical formula 1, wherein the method of production of the present invention comprises:

[0025] (i) a step of reacting a sulfonyl fluoride of the following chemical formula 2 with a carbonate to form a salt of the following chemical formula 3;

[0026] (ii) The method includes the step of thermally decomposing the salt of the above chemical formula 3 in a high-boiling point solvent having a boiling point of 280 to 400°C.

[0027] [Chemical Formula 1]

[0028]

[0029] [Chemical Formula 2]

[0030]

[0031] [Chemical Formula 3]

[0032]

[0033] In the above formula,

[0034] n is an integer from 0 to 2, and

[0035] M is an alkali metal, preferably lithium, sodium, or potassium.

[0037] In step (i) above, the sulfonyl fluoride of formula 2 is reacted with a carbonate to form a salt of formula 3.

[0038] The carbonate used in the present invention may be lithium carbonate, sodium carbonate, potassium carbonate, etc., but is not limited thereto.

[0039] In one embodiment of the present invention, the molar ratio of carbonate to sulfonyl fluoride of Formula 2 may be 1:1.2 to 1.8, preferably 1:1.4 to 1.7, more preferably 1:1.5 to 1.6.

[0040] In one embodiment of the present invention, the salt-forming reaction temperature may typically be in the range of 40 to 100°C, preferably in the range of 50 to 80°C.

[0041] The above salt formation reaction can be carried out in a low-boiling point solvent having a boiling point of 80 to 180°C, for example, diethylene glycol dimethyl ether, dimethoxyethane, or acetonitrile.

[0042] The above low-boiling point solvent can be removed by vacuum distillation after the salt formation reaction.

[0044] In step (ii) above, the salt of Formula 3 is subjected to a thermal decomposition reaction in a high-boiling point solvent having a boiling point of 280 to 400°C to produce perfluorinated sulfonyl fluoride vinyl ether (PSEPVE) of Formula 1.

[0045] As the above high-boiling point solvent, phthalate-based solvents, particularly dimethyl phthalate, di-n-butyl phthalate, dioctyl phthalate, etc., may be used.

[0046] The above high-boiling point solvent is non-volatile and can be recovered and reused.

[0047] It is preferable to use a dehydrated high-boiling point solvent, and the water concentration in the high-boiling point solvent is preferably 100 ppm by weight or less. If the water concentration exceeds 100 ppm by weight, it is undesirable because the sulfonyl fluoride of Formula 2 is hydrolyzed.

[0048] In one embodiment of the present invention, the weight ratio of the high-boiling point solvent to the sulfonyl fluoride of Formula 2 is 1:0.3 to 1.0, preferably 1:0.4 to 0.7, more preferably 1:0.5.

[0049] The above high-boiling point solvent may be added before the salt formation reaction or after the salt formation reaction.

[0050] In one embodiment of the present invention, the pyrolysis reaction temperature may be in the range of 100 to 300°C, preferably in the range of 180 to 250°C.

[0051] In one embodiment of the present invention, the pyrolysis reaction can be carried out while separating the perfluorinated sulfonyl fluoride vinyl ether (PSEPVE) of Formula 1, which is generated during the pyrolysis reaction, from the high-boiling point solvent by reduced-energy distillation. By separating the product directly during the pyrolysis reaction in this way, side reactions can be prevented and the yield can be increased.

[0052] The above pyrolysis reaction pressure may be in the range of 30 to 100 torr, preferably in the range of 40 to 60 torr.

[0053] Since the above pyrolysis reaction is known to undergo hydrolysis by moisture during high-temperature reactions, it is preferable to carry out the reaction in a moisture-free atmosphere. For example, it is preferable to carry out the reaction in an inert gas atmosphere such as nitrogen or argon.

[0054] The generated PSEPVE can be purified by fractional distillation. Effects of the invention

[0055] According to the manufacturing method of the present invention, perfluorinated sulfonyl fluoride vinyl ether (PSEPVE), which is used as a raw material for copolymerizing perfluorinated sulfonic acid (PFSA) ionomer, an ion-conducting polymer known to have excellent ion conductivity and chemical and mechanical stability, can be manufactured economically and industrially by using a high-boiling point solvent, thereby enabling uniform heat transfer and effective stirring. Furthermore, by separating the product directly by vacuum distillation during the pyrolysis reaction, side reactions can be prevented, thereby improving the yield. Specific details for implementing the invention

[0056] The present invention will be explained more specifically below through examples. These examples are provided solely to illustrate the invention, and it is obvious to those skilled in the art that the scope of the invention is not limited to these examples.

[0058] Examples 1: Perfluoro(4-methyl-3,6-dioxaoct-7-en)sulfonyl Perfluorofluoride (4-methyl-3,6-dioxaoct-7-ene)sulfonyl fluoride: PSEPVE Manufacturing of )

[0059] The inside of a 500 mL three-necked round-bottom (RB) flask equipped with a distillation apparatus was purged with nitrogen. Under a nitrogen atmosphere, 46.8 g of anhydrous diethylene glycol dimethyl ether and 40.5 g of anhydrous potassium carbonate were added. The mixture was heated to 50°C and, while stirring, 100 g of 2,5-di(trifluoromethyl)-3,6-dioxa-8-(sulfonylfluoride)perfluorooctanoyl fluoride was injected over 3 hours. The mixture was stirred at 60°C for 5 hours. Under a nitrogen atmosphere, 49.5 g of anhydrous dioctyl phthalate (DOP) was added, and the low-boiling point solvent was removed by vacuum distillation. The mixture was heated to 210°C under a reduced pressure of 50 torr in a distillation apparatus, and the reaction was carried out at 210°C until the distillation was finished. The distillate was fractionally distilled to obtain 77.5g of the target product (yield 89.0%).

[0060] 19 F-NMR 400MHz (CDCl3, ppm): 43.1(s), -81.0(d), -81.9(s), -86.5(d), -114.1(s), -116.6(q), -124.2(q), -138.4(q), -146.3(m)

[0062] Examples 2: Perfluoro(4-methyl-3,6-dioxaoct-7-en)sulfonyl Perfluorofluoride (4-methyl-3,6-dioxaoct-7-ene)sulfonyl fluoride: PSEPVE Manufacturing of )

[0063] The inside of a 500 mL three-necked round-bottom (RB) flask equipped with a distillation apparatus was purged with nitrogen. Under a nitrogen atmosphere, 46.8 g of anhydrous diethylene glycol dimethyl ether and 49.5 g of anhydrous DOP were added. 33.1 g of sodium carbonate was added and heated to 50°C. While stirring at 50°C, 100 g of 2,5-di(trifluoromethyl)-3,6-dioxa-8-(sulfonylfluoride)perfluorooctanoyl fluoride was injected over a period of 3 hours. The mixture was stirred at 80°C for 5 hours, and the low-boiling point solvent was removed by vacuum distillation. Under the distillation apparatus, the mixture was heated to 210°C under a reduced pressure of 50 torr and the reaction was carried out at 210°C until the distillation was complete. The distillate was fractionally distilled to obtain 73.1g of the target product (yield 83.9%).

[0064] 19 F-NMR 400MHz (Acetone-d6, ppm): 43.1(s), -81.0(d), -81.9(s), -86.5(d), -114.1(s), -116.6(q), -124.2(q), -138.4(q), -146.3(m)

[0066] Examples 3: Perfluoro(4-methyl-3,6-dioxaoct-7-en)sulfonyl Perfluorofluoride (4-methyl-3,6-dioxaoct-7-ene)sulfonyl fluoride: PSEPVE Manufacturing of )

[0067] The inside of a 500 mL three-necked round-bottom (RB) flask equipped with a distillation apparatus was purged with nitrogen. Under a nitrogen atmosphere, 46.8 g of anhydrous diethylene glycol dimethyl ether and 49.5 g of anhydrous DOP were added. 40.5 g of potassium carbonate was added and heated to 50°C. While stirring at 50°C, 100 g of 2,5-di(trifluoromethyl)-3,6-dioxa-8-(sulfonylfluoride)perfluorooctanoyl fluoride was injected over a period of 3 hours. The mixture was stirred at 60°C for 5 hours, and the low-boiling point solvent was removed by vacuum distillation. Under the distillation apparatus, the mixture was heated to 210°C under a reduced pressure of 50 torr and the reaction was carried out at 210°C until the distillation was complete. The distillate was fractionally distilled to obtain 74.7g of the target product (yield 85.8%).

[0068] 19 F-NMR 400MHz (Acetone-d6, ppm): 43.1(s), -81.0(d), -81.9(s), -86.5(d), -114.1(s), -116.6(q), -124.2(q), -138.4(q), -146.3(m)

[0070] Comparative example 1: Perfluoro(4-methyl-3,6-dioxaoct-7-en)sulfonyl Perfluorofluoride (4-methyl-3,6-dioxaoct-7-ene)sulfonyl fluoride: PSEPVE Manufacturing of )

[0071] The inside of a 500 mL three-necked round-bottom (RB) flask equipped with a distillation apparatus was purged with nitrogen. Under a nitrogen atmosphere, 31.8 g of anhydrous diethylene glycol dimethyl ether and 30.1 g of sodium carbonate were added and heated to 60°C. At 60°C, while stirring, 100 g of 2,5-di(trifluoromethyl)-3,6-dioxa-8-(sulfonylfluoride)perfluorooctanoyl fluoride was injected over a period of 3 hours. The mixture was stirred at 60°C for 12 hours, and the solvent was removed by vacuum distillation. The mixture was vacuum dried at 60°C for 24 hours. A salt pyrolysis reaction was performed on the dried sodium salt while heating it from 100°C to 180°C for 3 hours to obtain 38.4g of the target product (yield 44.1%).

[0072] 19 F-NMR 400MHz (Acetone-d6, ppm): 43.1(s), -81.0(d), -81.9(s), -86.5(d), -114.1(s), -116.6(q), -124.2(q), -138.4(q), -146.3(m)

Claims

Claim 1 (i) a step of reacting a sulfonyl fluoride of Formula 2 below with a carbonate to form a salt of Formula 3 below; (ii) a step of thermally decomposing the salt of Formula 3 in a high-boiling point solvent having a boiling point of 280 to 400°C, wherein the high-boiling point solvent is one or more selected from the group consisting of dimethyl phthalate, di-n-butyl phthalate, and dioctyl phthalate; a method for preparing a perfluorinated sulfonyl fluoride vinyl ether (PSEPVE) of Formula 1 below: [Formula 1] [Chemical Formula 2] [Chemical Formula 3] In the above formula, n is an integer from 0 to 2, and M is an alkali metal. Claim 2 A method of manufacturing in which the carbonate in claim 1 is lithium carbonate, sodium carbonate, or potassium carbonate. Claim 3 A manufacturing method according to claim 1, wherein the salt formation reaction temperature is 50 to 80℃. Claim 4 A manufacturing method according to claim 1, wherein the salt formation reaction is carried out in a low-boiling point solvent having a boiling point of 80 to 180°C. Claim 5 A manufacturing method in which, in paragraph 4, the low-boiling point solvent is removed by vacuum distillation after the salt formation reaction. Claim 6 delete Claim 7 A method for manufacturing according to claim 1, wherein the weight ratio of the high-boiling point solvent compound to the sulfonyl fluoride of formula 2 is 1:0.3 to 1.

0. Claim 8 A manufacturing method according to claim 1, wherein the high-boiling point solvent is added before the salt formation reaction or after the salt formation reaction. Claim 9 A manufacturing method according to claim 1, wherein the pyrolysis reaction temperature is 180 to 250℃. Claim 10 A method for manufacturing according to claim 1, wherein the perfluorinated sulfonyl fluoride vinyl ether (PSEPVE) of Formula 1 generated during the pyrolysis reaction is separated from a high-boiling point solvent by reduced-energy distillation while performing the pyrolysis reaction. Claim 11 A manufacturing method according to claim 1, wherein the pyrolysis reaction pressure is 40 to 60 torr.

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