Apparatus and method for producing high-purity perfluorotripropylamine (PFTPA)

Abstract

The present invention relates to a device and a method for producing perfluorotripropylamine (PFTPA) by using an electrochemical fluorination (ECF) method, and more particularly, to a device and a method for producing perfluorotripropylamine (PFTPA) by using an electrochemical fluorination (ECF) method. The manufacturing method according to one embodiment of the present invention comprises: a manufacturing step in which PFTPA is manufactured from a mixed solution of tripropylamine (TPA) and hydrogen fluoride (HF) by an electrochemical fluorination method; a separation step in which the produced PFTPA is separated from a mixed solution of TPA and hydrogen fluoride; and a moisture removal step in which moisture included in the produced PFTPA is removed. In this case, in the moisture removal step, moisture may be removed by adding at least one of calcium hydride (CaH2) and magnesium sulfate (MgSO4) to the produced PFTPA and stirring, or moisture may be removed by adding at least one of a molecular sieve having pores of a predetermined size and silica gel to the produced PFTPA and stirring.

Description

Technical Field

[0001] The present invention relates to the fluorination of tripropylamine (TPA), and more particularly to a technology for preparing high-purity perfluoro tripropylamine (PFTPA) from TPA. Background Art

[0002] Perfluorotripropylamine (PFTPA) is a colorless, odorless liquid composed only of fluorine (F), carbon (C) and nitrogen (N), and has excellent insulation, heat resistance, corrosion resistance, chemical resistance and low viscosity characteristics. Therefore, PFTPA is mainly used in various applications throughout the electrical and electronic industries including semiconductors and displays, such as insulating refrigerants, cleaning solvents, fire extinguishing agents and lubricating oils. In particular, PFTPA has physical properties such as high insulation characteristics (5×1015ohm·cm), thermal stability and excellent thermal conductivity (0.66W / m℃), so it is widely used as a refrigerant in semiconductor manufacturing equipment and display manufacturing equipment such as dry etcher or ion implanter.

[0003] Electrochemical fluorination (ECF) is generally used to manufacture PFTPA. In the ECF method, PFTPA is manufactured by applying a predetermined electrical energy to a mixed solution of tripropylamine (TPA) and anhydrous hydrogen fluoride (aHF) and replacing all C—H bonds contained in TPA with C—F bonds. For example, the ECF method can be used to manufacture PFTPA from TPA, as disclosed in the US registered patent No. 2,519,983 "ELCETROCHEMICAL PROCESS OF MAKINGFLUORINE-CONTAINING CARBON COMPOUNDS". The method of manufacturing PFTPA and the like using this ECF method was first commercialized by 3M in the 1950s and is widely known as the Simons ECF method.

[0004] However, the conventional PFTPA produced by the ECF method may contain some impurities such as isomers and water, including intermediate products. When PFTPA contains various impurities, there is a problem that the desired physical properties, such as high insulation properties or excellent thermal conductivity, cannot be fully exerted.

[0005] [Prior Technical Literature]

[0006] (Patent Document 1) U.S. Registered Patent No. 2,519,983 Summary of the invention

[0007] Technical issues

[0008] Perfluorotripropylamine (PFTPA) is widely used as a refrigerant or chiller for semiconductor manufacturing equipment due to its high resistivity. In semiconductor manufacturing processes, especially in semiconductor manufacturing processes using plasma, a high current is applied to the semiconductor manufacturing equipment to generate plasma. However, when the high current moves through the refrigerant of the semiconductor manufacturing equipment, it may affect other components in the device and surrounding devices, causing the device to malfunction or fail. In order to prevent the above situation, PFTPA with high resistivity is widely used as a refrigerant for semiconductor processes.

[0009] PFTPA used as a refrigerant must have a high resistivity value, that is, its excellent insulation properties must not be compromised. However, when the manufactured PFTPA contains impurities, there is a risk that the resistivity is reduced and the insulation properties are deteriorated. For example, during the process of manufacturing PFTPA or during chemical purification treatment, moisture may be dissolved into PFTPA, and even if the amount of moisture contained in PFTPA is small, it is a factor that reduces the resistivity of PFTPA.

[0010] Therefore, in order to manufacture PFTPA having excellent properties, especially PFTPA having excellent insulation properties, it is necessary to suppress the dissolution of water into PFTPA as much as possible, or remove the dissolved water as much as possible, during the manufacturing process of PFTPA or its post-processing.

[0011] The present invention provides a high-purity PFTPA manufacturing device and method, which can suppress or reduce various impurities including water when PFTPA is manufactured from tripropylamine (TPA) by electrochemical fluorination (ECF).

[0012] Solutions to the problem

[0013] According to an embodiment of the present invention, a method for producing high-purity perfluorotripropylamine (PFTPA) includes a production step, in which PFTPA is produced from a mixed solution of tripropylamine (TPA) and hydrogen fluoride (HF) using electrochemical fluorination (ECF); a separation step, in which the produced PFTPA is separated from the mixed solution of TPA and hydrogen fluoride; and a moisture removal step, in which moisture included in the produced PFTPA is removed.

[0014] According to one aspect of the embodiment, in the moisture removal step, at least one of calcium hydride (CaH2) and magnesium sulfate (MgSO4) may be added to the manufactured PFTPA and stirred to remove moisture. Alternatively, in the moisture removal step, at least one of a molecular sieve having pores of a predetermined size and silica gel may be added to the manufactured PFTPA and stirred to remove moisture.

[0015] According to another aspect of the embodiment, the manufacturing method may further include a purification step of subjecting the separated PFTPA to a chemical purification process after the PFTPA separation step, wherein in the moisture removal step, moisture included in the PFTPA purified in the purification step may also be removed.

[0016] According to another aspect of the embodiment, in the manufacturing step, PFTPA can be manufactured by passing a mixed solution of TPA and hydrogen fluoride through a channel in forced convection, wherein the channel is a space between a plurality of cathode electrode plates and a plurality of anode electrode plates separated by intervals of 3 mm to 5 mm and alternately arranged, wherein the flow rate of the mixed solution flowing through the channel is controlled to be 4 L / min to 10 L / min by considering the yield of the product, i.e., PFTPA, and the concentration of impurities included in the product.

[0017] According to one embodiment of the present invention, a manufacturing device for high-purity PFTPA includes an electrochemical reactor, which is used to generate PFTPA by applying electrical energy to a mixed solution of tripropylamine (TPA) and hydrogen fluoride (HF) using an electrochemical fluorination method (ECF); a solution separator, which is used to separate a PFTPA solution from a mixed solution of TPA and hydrogen fluoride and a PFTPA solution discharged from the electrochemical reactor; and a moisture removal unit, which is used to remove moisture from the PFTPA discharged from the solution separator.

[0018] According to one aspect of the embodiment, the moisture removal unit can remove moisture by using at least one of calcium hydride (CaH2) and magnesium sulfate (MgSO4). Alternatively, the moisture removal unit can remove moisture by using at least one of a molecular sieve having pores of a predetermined size and silica gel.

[0019] According to another aspect of the embodiment, the manufacturing apparatus may further include a purification unit for performing a chemical purification process on the PFTPA discharged from the solution separator, wherein the moisture removal unit may also remove moisture from the purified PFTPA discharged from the purification unit.

[0020] According to another aspect of the embodiment, the electrochemical reactor includes: an electrolytic cell; an inlet for introducing a mixed solution of TPA and hydrogen fluoride into the electrolytic cell; an outlet for discharging a product including PFTPA generated by the ECF reaction of the mixed solution from the electrolytic cell; and a plurality of cathode electrode plates and a plurality of anode electrode plates, which are separated and alternately arranged at intervals of 3 mm to 5 mm in the electrolytic cell, wherein the manufacturing device further includes: a solution supplier, which supplies the mixed solution to the electrolytic cell through the inlet; and a flow controller, which controls the flow rate of the mixed solution supplied by the solution supplier, which controls the flow rate by considering the yield of PFTPA and the concentration of the impurities, and controls the flow rate of the mixed solution flowing through the space, i.e., the channel, between the cathode electrode plate and the anode electrode plate to be 4 L / min to 10 L / min.

[0021] Effects of the Invention

[0022] According to the above-mentioned embodiments of the present invention, by manufacturing perfluorotripropylamine (PFTPA) by electrochemical fluorination (ECF) and removing the water contained therein, it is possible to manufacture a coolant having excellent resistivity (for example, a resistivity of 10 9 Furthermore, when PFTPA is produced by the ECF method, the content of cyclic isomers that are difficult to separate from PFTPA can be reduced or suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention is a block diagram schematically showing the structure of a high-purity perfluorotripropylamine (PFTPA) production device according to an embodiment of the present invention.

[0024] Figure 2 The present invention is a block diagram schematically showing the structure of a high-purity PFTPA production apparatus according to another embodiment of the present invention.

[0025] Figure 3 The figure schematically shows the arrangement of a bipolar electrode structure.

[0026] Figure 4 This is a formula showing that all hydrogen atoms in tripropylamine (TPA) are replaced by fluorine atoms to form PFTPA. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The terms and words used in this specification are selected in consideration of their functions in the embodiments, and the meanings of the terms may vary according to the intention or convention of the present invention, etc. Therefore, when the terms used in the embodiments described below are specifically defined in this specification, the definition should be followed, and if there is no specific definition, it should be interpreted with the meaning generally recognized by those skilled in the art.

[0028] Figure 1 The block diagram schematically shows the structure of a high-purity perfluorotripropylamine (PFTPA) production device (hereinafter referred to as "production device") according to one embodiment of the present invention. Figure 1 The manufacturing device 10 includes an electrochemical reactor 11 and a solution separator 12, and includes at least one of first and second moisture removal units 13 and 15. Also, according to an embodiment, the manufacturing device 10 may further include a purification unit 14.

[0029] Figure 1 The manufacturing apparatus 10 shown is an apparatus for manufacturing PFTPA from a mixed solution of tripropylamine (TPA) and hydrogen fluoride (HF) by electrochemical fluorination (ECF), and is an apparatus for manufacturing high-purity PFTPA with reduced water content. Generally, a small amount of water may be dissolved into PFTPA during the process of manufacturing PFTPA and / or post-processing such as a chemical purification process. However, when using Figure 1 In the manufacturing apparatus 10 shown, high-purity PFTPA can be manufactured by removing moisture contained in PFTPA using at least one of two moisture removal units (ie, first and second moisture removal units 13 and 15).

[0030] The electrochemical reactor 11 is a device for applying electric energy to a mixed solution of TPA and HF through electrodes to cause a reaction to generate PFTPA. In other words, the electrochemical reactor 11 is a device for generating PFTPA from a mixed solution of TPA and HF, which are reactants, through an ECF reaction. According to this embodiment, as long as this electrochemical reactor 11 is a device for generating PFTPA through the ECF method, the type or structure of the device is not particularly limited.

[0031] According to one aspect of the present embodiment, the electrochemical reactor 11 has a structure that continuously supplies a mixed solution of TPA and HF at a predetermined flow rate through an inlet, and simultaneously discharges the product, namely PFTPA, unreacted substances (i.e., a mixed solution of TPA and HF), and reaction byproducts, etc. through an outlet located on the opposite side of the inlet. Accordingly, the reactants stay around the electrode located between the inlet and the outlet for a predetermined time, and during this period, an ECF reaction occurs on the surface of the electrode. And, as the mixed solution of TPA and HF is continuously supplied to the electrochemical reactor 11, the product, namely PFTPA, is discharged through the outlet together with the unreacted substances.

[0032] To this end, an electrode is provided between the inlet and outlet of the electrochemical reactor 11, which is used to apply a predetermined electric energy to the mixed solution. For example, the electrode may be a bipolar electrode structure in which a plurality of anode electrode plates and a plurality of cathode electrode plates are alternately provided. However, the present embodiment is not limited thereto, and only a pair of anode electrode plates and cathode electrode plates may be provided, or the anode electrode plates and cathode electrode plates may be arranged in another form.

[0033] The solution separator 12 is a unit for separating PFTPA from the mixed liquid discharged through the outlet of the electrochemical reactor 11. Generally, the liquid (hereinafter referred to as "discharge liquid") flowing out of the electrochemical reactor 11 and flowing into the solution separator 12 includes PFTPA, a mixed solution of TPA and HF as a reaction substance, reaction byproducts (impurities), water, etc., and the solution separator 12 is used to separate PFTPA from the discharge liquid.

[0034] According to one aspect of the present embodiment, the solution separator 12 can separate PFTPA from the discharged liquid by utilizing the density difference of each liquid. At the process temperature in the electrochemical reactor 110, the density of PFTPA is 1.82 g / mL, the density of HF is 1 g / mL, and the density of TPA is 0.75 mg / L, and therefore, in the solution separator 12, each solution can be separated by the density difference. More specifically, PFTPA having the highest density sinks in the lower part of the solution separator 12. And, the PFTPA sinking in the lower part is transported to a storage tank (not shown) connected to the outflow port or the like through the outflow port formed on the bottom surface of the solution separator 12.

[0035] The first moisture removal unit 13 is used to remove moisture from the PFTPA solution separated and discharged from the solution separator 12. In the solution separator 12, etc., moisture contained in the atmosphere may be dissolved into the PFTPA, or in the storage tank, etc. storing the PFTPA separated from the solution separator 12, moisture may be dissolved into the PFTPA, and the first moisture removal unit 13 is used to remove the moisture from the PFTPA. Therefore, the first moisture removal unit 13 is installed on the downstream side of the solution separator 12 (the side where the PFTPA is discharged), and it may be installed in the storage tank or additionally installed near the storage tank.

[0036] Furthermore, according to one aspect of the present embodiment, the first moisture removal unit 13 removes moisture by using a predetermined compound that can react with moisture (water) to form a precipitate, namely calcium hydride (CaH2). To this end, in the first moisture removal unit 13, CaH2 is added to PFTPA at a predetermined concentration and stirred to generate a precipitate. The principle of removing moisture using CaH2 is shown in the following chemical formula 1.

[0037] [Reaction 1]

[0038] CaH2+2H2O→Ca(OH)2+2H2

[0039] According to reaction formula 1, in the first moisture removal unit 13, the moisture contained in PFTPA reacts with CaH2 to generate by-products, namely Ca(OH)2 and hydrogen (H2). And, the generated Ca(OH)2 is precipitated below the PFTPA solution located in the first moisture removal unit 13, and the generated hydrogen (H2) is discharged as a gas, so it can be easily separated.

[0040] According to another aspect of the present embodiment, the first moisture removal unit 13 removes moisture using a predetermined compound that can combine with moisture (water) to form a hydrate, namely magnesium sulfate (MgSO4). To this end, in the first moisture removal unit 13, MgSO4 is added to PFTPA at a predetermined concentration and stirred to generate a hydrate. The principle of removing moisture using MgSO4 is shown in the following chemical formula 2. And, chemical formula 1 shows the form of magnesium sulfate combined with water as a reaction result of reaction formula 2 to form a hydrate.

[0041] [Reaction 2]

[0042] MgSO4+H2O<->Mg 2+ +SO4 2+ +H2O

[0043]

Chemical formula 1

[0044]

[0045] According to Reaction Formula 2, in the first moisture removal unit 13, the moisture contained in PFTPA ionizes MgSO 4 , so that MgSO 4 is combined with the moisture to form a hydrate, and is separated from PFTPA.

[0046] According to another aspect of the present embodiment, the first moisture removal unit 13 removes moisture by using an adsorbent having excellent affinity with moisture (water) (hereinafter referred to as a "moisture adsorbent"). The moisture adsorbent includes, for example, a molecular sieve or silica gel, etc. To this end, in the first moisture removal unit 13, the moisture adsorbent is added to PFTPA at a predetermined concentration and stirred, and then separated from PFTPA by filtration.

[0047] The PFTPA separated from the solution separator 12 or the PFTPA from which water is removed in the first water removal unit 13 is transferred to the purification unit 14. This is because there is a certain limit in extracting high-purity PFTPA from the discharged liquid by utilizing the density difference in the solution separator 12. In other words, the liquid extracted from the solution separator 12 to the lower side by the density difference may include trace amounts of impurities such as unreacted raw materials, reaction by-products, and water.

[0048] Therefore, in order to produce high-purity PFTPA, in addition to the physical separation process using the density difference, a purification process of PFTPA may be required to chemically remove impurities contained in PFTPA. And for this purpose, the manufacturing apparatus 10 may additionally have a purification unit 14. According to the present embodiment, the specific mechanism of the purification process in the purification unit 14 is not particularly limited as long as it is a process for removing other impurities contained in the product, and any process may be used.

[0049] According to one aspect of the present embodiment, the purification unit 14 may be directly coupled to the solution separator 12 without passing through the first moisture removal unit 13, or may be additionally disposed on the downstream side of the first moisture removal unit 13. Alternatively, according to an embodiment, the purification unit 14 may be formed integrally with the storage tank or the purification unit 14 may be disposed on the downstream side of the storage tank, instead of the purification unit 14 or separately therefrom.

[0050] The second moisture removal unit 15 is used to remove moisture from the PFTPA solution purified and discharged from the purification unit 14. During the purification process in the purification unit 14, moisture contained in the atmosphere and / or moisture contained in the solution used in the purification process may be dissolved into the PFTPA, and the second moisture removal unit 15 is used to remove the moisture from the PFTPA. Therefore, the second moisture removal unit 15 is installed on the downstream side of the purification unit 14, and it can be installed in the storage tank or additionally installed near the storage tank.

[0051] Furthermore, according to one aspect of the present embodiment, the method for removing moisture from the PFTPA by the second moisture removal unit 15 can utilize the method applied to the first moisture removal unit 13. For example, moisture can also be removed in the second moisture removal unit 15 by utilizing a predetermined compound capable of reacting with moisture (water) to generate a precipitate, namely, calcium hydride (CaH2), or by utilizing magnesium sulfate (MgSO4) that combines with moisture in the form of a hydrate, or by utilizing a moisture absorbent such as silica gel or a molecular sieve, etc. In this case, the method applied to the first moisture removal unit 13 and the method applied to the second moisture removal unit 15 do not necessarily need to be the same method.

[0052] As described in detail above, according to an embodiment of the present invention, PFTPA is manufactured from a mixed solution of TPA and HF by the ECF method, and the moisture contained in the manufactured PFTPA is removed by using at least one of calcium hydride (CaH2) and magnesium sulfate (MgSO4) or by using a moisture absorbent such as magnesium sulfate (MgSO4) or silica gel, thereby being able to manufacture high-purity PFTPA.

[0053] Figure 2 This is a block diagram schematically showing the structure of a PFTPA manufacturing device (hereinafter referred to as "manufacturing device") according to another embodiment of the present invention. Figure 2 The manufacturing apparatus 100 includes an electrochemical reactor 110, a solution separator 120, a solution supplier 130, a flow controller C, and at least one of first and second moisture removal units 170A and 170B. In addition, the manufacturing apparatus 100 may further include a purification unit 140, a heat exchanger 150, and / or a flow meter 160.

[0054] Figure 2 The manufacturing apparatus 100 shown may be Figure 1 An embodiment of the manufacturing device 10 shown in FIG. Figure 1 The differences of the manufacturing apparatus 10 shown are not centrally described. Therefore, matters not specifically described herein may be equally applied to the reference Figure 1 Describe the matter.

[0055] The electrochemical reactor 110 has an electrolytic cell 111, which defines a space in which a chemical reaction occurs in which a mixed solution of TPA and HF is converted into PFTPA when electric energy is applied. The electrolytic cell 111 is a container for accommodating a mixed solution and a reaction product. The electrolytic cell 111 is formed of a material that is inert to hydrogen fluoride and has electrical insulation, or at least its inner surface is coated with the above material. For example, the electrolytic cell 111 can be formed of a Hastelloy material, or can be lined with Teflon. In addition, the internal filler of the electrolytic cell 111 can also use fluororesins such as polytetrafluoroethylene (PTFE), perfluoroalkoxy polymers (PFA), polyvinylidene fluoride (PolyVinyliDene Fluoride), or polymer resin materials such as polypropylene (PolyPropylene, PP) and polyethylene (PolyEthylene, PE).

[0056] The electrochemical reactor 110 has an inlet 114 for introducing a mixed solution of TPA and hydrogen fluoride into the interior of the electrolytic cell 111. The inlet 114 preferably has a structure capable of controlling the inflow of the solution by a valve device or the like, but is not limited thereto. The inlet 114 is preferably disposed on the bottom surface of the electrolytic cell 111 so that the mixed solution of TPA and HF having a relatively low density compared to the product PFTPA can flow smoothly in the container. However, the present embodiment is not limited thereto, and for example, the inlet 114 may also be disposed below one side of the electrolytic cell 111.

[0057] The inflow of the mixed solution through the inflow port 114 is either the inflow of the individual solutions (here, the hydrogen fluoride solution and the TPA solution) constituting the mixed solution through their own separate inflow ports, or the inflow through the inflow port 114 after being premixed in a pipe or an intermediate tank, etc. In the former case, the concentration of the mixed solution to be obtained in the electrolytic cell 111 can be matched by adjusting the flow rate of each solution individually. In contrast, in the latter case, a prefabricated mixed solution having a predetermined concentration can be flowed into the electrolytic cell 111 through the inflow port 114.

[0058] The electrochemical reactor 110 has an outlet 116 for discharging the solution including the reaction product, namely PFTPA, to the outside of the electrolytic cell 111. The outlet 116 also preferably has a structure capable of controlling the outflow of the solution by a valve device, etc., but is not limited thereto. The outlet 116 is arranged in the opposite direction to the inlet 114, for example, Figure 2 As shown, when the inlet 114 is provided at the bottom surface of the electrolytic cell 111, the outlet 116 is preferably provided above the side of the electrolytic cell 111. In this case, when the liquid level in the electrolytic cell 111 of the electrochemical reactor 110 is at a certain level or higher (i.e., higher than the position of the outlet 116), the solution including the product, i.e., PFTPA, flows out to the outside of the electrolytic cell 111 through the outlet 116. The solution discharged through the outlet 116 includes the reaction product and an unreacted mixed solution of TPA and HF.

[0059] As the inside of the electrolytic cell 111, an electrode for applying predetermined electric energy to the mixed solution is provided in the space between the inlet 114 and the outlet 116. For example, the electrode may be a bipolar electrode structure in which a plurality of anode electrode plates and a plurality of cathode electrode plates are alternately provided. Figure 3 The configuration of the bipolar electrode structure 112 is schematically shown. Figure 3 The bipolar electrode structure 112 includes a plurality of anode electrode plates 112a and a plurality of cathode electrode plates 112b that are spaced apart at predetermined intervals and arranged alternately in parallel. The method of installing the anode electrode plates 112a and the cathode electrode plates 112b in the electrolytic cell 111 by separating them is not particularly limited.

[0060] According to one aspect of the present embodiment, the anode electrode plate 112a and the cathode electrode plate 112b may be disposed to be spaced apart from each other at intervals of about 3 mm to about 5 mm, respectively. The number, size, shape, etc. of each of the anode electrode plate 112a and the cathode electrode plate 112b are not particularly limited, and may be appropriately selected in consideration of the size or shape of the electrolytic cell 111.

[0061] The anode electrode plate 112a and the cathode electrode plate 112b are conductive, inert to hydrogen fluoride, and are formed of a material that is active in an electrochemical fluorination reaction when used as an anode electrode. For example, the anode electrode plate 112a and the cathode electrode plate 112b can be formed of nickel (Ni) or platinum (Pt), and nickel is more economical than platinum.

[0062] According to one aspect of the present embodiment, the bipolar electrode structure 112 is installed at an appropriate position in the electrolytic cell 111 so that the mixed solution flowing in through the inlet 114 can flow through the space (hereinafter referred to as the "channel") between the anode electrode plate 112a and the cathode electrode plate 112b at a predetermined flow rate. Accordingly, at least most of the mixed solution flows through the channel, or all of it flows through the channel. According to an embodiment, a predetermined structure for guiding the flow of the mixed solution can be installed near the inlet 114 to prevent the mixed solution from bypassing the bipolar electrode structure 112. However, it is not limited to this structure, and a portion of the mixed solution may also flow to the outside of the outermost anode electrode plate 112a and / or the outermost cathode electrode plate 112b.

[0063] In addition to the outflow port 116 for discharging the liquid component in the product, the electrolytic cell 111 may also be provided with an exhaust hole (not shown) for discharging the gas component. In order to effectively discharge the gas component, the exhaust hole is preferably formed on the upper surface of the electrolytic cell 111. Through the exhaust hole, not only the hydrogen gas as the reaction product but also the hydrogen fluoride gas evaporated during the reaction can be discharged.

[0064] The ECF reaction in such an electrochemical reactor 110 occurs as follows. More specifically, a mixed solution (e.g., a mixed solution in which the concentration of TPA is about 3 wt % to about 30 wt %) flows into the interior of the electrolytic cell 111 through the inlet 114. When the electrolytic cell 111 is filled with the mixed solution, a predetermined voltage (e.g., 5 V to 8 V) and a current (e.g., 5 mA / cm 2 ) are applied by using the anode electrode plate 112 a and the cathode electrode plate 112 b. 2 Up to 50mA / cm 2 ). Therefore, the liquid hydrogen fluoride is ionized, and the hydrogen ions (H + ) moves to the cathode electrode plate 112b, and the fluoride ions (F -) moves to the anode electrode plate 112a. As a result, on the surface of the anode electrode plate 112a, an electrode material such as nickel combines with fluorine ions (F-) to generate a thin film of NiF2. And, on the surface of the anode electrode plate 112a, NiF3 or NiF4, etc. are generated through continuous reactions. Continuously, the generated NiF3 or NiF4, etc. reacts with TPA, the hydrogen (H) in TPA combines with the fluorine (F) of NiF3 or NiF4, etc. and falls off in the form of HF, and the carbon (C) in TPA that has lost hydrogen undergoes a fluorination reaction to combine with other fluorine (F) of NiF3 or NiF4, etc. As a result, as Figure 4 As shown, all hydrogens in TPA are replaced by fluorines to produce PFTPA.

[0065] HF must be maintained in a liquid state in the electrochemical reactor 110 to continue the fluorination reaction of TPA. More specifically, although the reaction in the anode electrode plate 112a and the cathode electrode plate 112b generates heat, the internal temperature of the electrolytic cell 111 of the electrochemical reactor 110 must be maintained at about 19° C. or less. Preferably, the internal temperature of the electrolytic cell 111 is preferably maintained at about 0° C. to 5° C. To this end, a temperature regulating unit (not shown) for controlling the temperature of the solution may be installed in the electrolytic cell 111.

[0066] The solution separator 120 is a unit for separating PFTPA from the liquid discharged through the outlet 116 of the electrolytic cell 111. Generally, the liquid discharged through the outlet 116 (hereinafter referred to as "discharged liquid") also includes PFTPA, a mixed solution of TPA and HF, which are reaction substances, reaction byproducts (impurities), water, etc., and the solution separator 120 is used to separate PFTPA from the discharged liquid.

[0067] The first moisture removal unit 170A is used to remove moisture from the PFTPA solution separated and discharged from the solution separator 120. For example, the first moisture removal unit 170A removes moisture by using a predetermined compound that can react with moisture (water) to generate a precipitate, namely calcium hydride (CaH2). Alternatively, the first moisture removal unit 170A can remove moisture by using a compound that can combine with moisture in the form of a hydrate, namely magnesium sulfate (MgSO4).

[0068] Alternatively, the first moisture removal unit 170A removes moisture by using a moisture adsorbent having excellent affinity with moisture (water). The moisture adsorbent includes, for example, a molecular sieve or silica gel, etc. To this end, in the first moisture removal unit 170A, the moisture adsorbent is added to PFTPA at a predetermined concentration and stirred, and then separated from PFTPA by filtration.

[0069] The PFTPA separated from the solution separator 120 or the PFTPA from which water is removed in the first water removal unit 170A is transported to the purification unit 140. The purification unit 140 is a device for chemically removing impurities contained in the product, that is, PFTPA. According to the present embodiment, the specific mechanism of the purification process in the purification unit 140 is not particularly limited as long as it is a process for removing other impurities contained in the product, and any process can be used.

[0070] The second moisture removal unit 170B is used to remove moisture from the PFTPA solution purified and discharged from the purification unit 140. The second moisture removal unit 170B may also remove moisture by using calcium hydride (CaH2), magnesium sulfate (MgSO4) or a moisture adsorbent.

[0071] The solution supplier 130 is a unit for supplying a mixed solution of TPA and HF to the inlet 114 of the electrochemical reactor 110 at a predetermined flow rate. The mixed solution flowing into the solution supplier 130 is supplied by a starting material supply unit (not shown), and also includes a mixed solution separated and reused from the solution separator 120. And, the solution supplier 130 pumps the flowing mixed solution at a predetermined flow rate (or flow rate) and supplies the mixed solution to the electrochemical reactor 110 through the inlet 114. To this end, the solution supplier 130 may include a pumping unit (e.g., a pump) capable of adjusting the flow rate / flow rate of the solution supplied to the inlet 114.

[0072] According to one aspect of the present embodiment, the flow rate (flow rate) of the solution supplied to the inlet 114 by the solution supplier 130 can be controlled. To this end, the manufacturing apparatus 100 can have a flow controller C for controlling the flow rate of the solution supplied by the solution supplier 130. The type of such flow controller C is not particularly limited, and for example, the flow rate can be controlled by controlling the amount of current supplied to the solution supplier 130. As will be described later, the flow controller C controls the solution supplier 130 to optimize the flow rate of the solution supplied to the electrochemical reactor 110, thereby increasing the yield of PFTPA generated in the electrochemical reactor 110 as much as possible, and at the same time reducing the concentration of impurities (particularly, isomers that are difficult to separate using the solution separator 120) as much as possible.

[0073] According to one aspect of the present embodiment, the flow meter 160 may be provided between the solution supplier 130 and the electrochemical reactor 110 to be able to measure the flow rate of the solution delivered to the inlet 114 by the solution supplier 130. In this case, the flow controller C may control the solution supplier 130 based on the flow rate measured by the flow meter 160, thereby optimizing the flow rate of the solution delivered to the inlet 114.

[0074] The storage tank 140 is a unit for storing the PFTPA solution separated from the solution separator 120. According to the present embodiment, the type, shape, size, material, etc. of the storage tank 140 are not particularly limited. The PFTPA solution stored in the storage tank 140 is then discharged to the outside as needed.

[0075] The heat exchanger 150 is a unit for cooling the gas exhausted through the exhaust hole of the electrochemical reactor 110. All or part of HF in the exhaust gas is liquefied by the heat exchanger 150 and is transported to the solution separator 120. On the contrary, the gas (e.g., hydrogen and HF(g)) in the exhaust gas that is not liquefied by the heat exchanger 150 is discharged to the outside.

[0076] The PFTPA manufacturing apparatus 100 as described above includes a solution supplier 130 that supplies a mixed solution to the electrochemical reactor 110 and a flow controller C that controls the same. When the flow rate (flow rate) of the mixed solution supplied to the electrochemical reactor 110 through the inlet 114 by the solution supplier 130 is adjusted by the control of the flow controller C, the amount of the solution discharged from the electrochemical reactor 110 through the outlet 116 to the solution separator 120 can be adjusted accordingly. As a result, the time that the product including the mixed solution stays in the electrochemical reactor 110 can be adjusted.

[0077] Thus, by controlling the flow rate of the mixed solution flowing into the electrochemical reactor 110, the flow rate of the mixed liquid flowing through the channel (i.e., the space between the anode electrode plate 112a and the cathode electrode plate 112b) can be adjusted. Furthermore, by adjusting the flow rate of the mixed liquid, the time that the product, i.e., PFTPA, stays in the channel can be adjusted. In particular, in an embodiment of the present invention, the flow rate of the mixed liquid flowing through the channel is controlled or optimized so that the synthesis rate of PFTPA is increased as much as possible (i.e., the yield of PFTPA is increased and / or the decomposition of the generated PFTPA is reduced) and the purity is also improved (i.e., the impurities included in the product, especially the cyclic isomers, are reduced).

[0078] According to the test results, it is confirmed that when the anode electrode plate 112a and the cathode electrode plate 112b are separated from each other by an interval of about 3 mm to about 5 mm, the best effect can be obtained when the flow rate in the channel ranges from about 4 L / min to about 10 L / min. Preferably, the flow rate ranges from about 6 L / min to about 8 L / min, in which the yield of PFTPA is the highest and the amount of impurities (especially isomers) generated is not significantly increased. If the flow rate is less than 4 L / min, the mixed solution of HF and TPA does not circulate smoothly, and the PFTPA generated between the anode electrode plate 112a and the cathode electrode plate 112b cannot be fully removed, thereby reducing the yield of PFTPA and increasing the generation of impurities. This is because the PFTPA that is not removed between the anode electrode plate 112a and the cathode electrode plate 112b is decomposed again and the impurities are increased. On the contrary, when the flow rate is greater than 10 L / min, the mixed solution of TPA and HF cannot fully stay between the anode electrode plate 112a and the cathode electrode plate 112b, so the reaction of converting TPA to PFTPA cannot proceed smoothly, resulting in a reduced production yield of PFTPA.

[0079] Table 1 shows the production yield, purity and content of impurities (i.e., isomers) of PFTPA that cannot be separated in the solution separator 120 according to the flow rate in the channel between the anode electrode plate 112a and the cathode electrode plate 112b. Referring to Table 1, it can be seen that when the flow rate is 4 L / min to 10 L / min, the yield of PFTPA is relatively high compared to other flow rates out of this range, and at the same time, the content of impurities, especially isomers included in PFTPA is relatively low.

[0080] [Table 1]

[0081] Flow rate (L / min) PFTPA yield (%) Impurities(%) Isomers (%) 1-4 39-45 33-36 2.8-3.1 4–10 44-49 25-29 1.8-2.5 10–15 38-43 22-27 1.7-2.4

[0082] In Table 1, flow rate represents the flow rate of the mixed solution in the channel between the anode electrode plate 112a and the cathode electrode plate 112b, PFTPA yield represents the "charge amount used in the PFTPA reaction" relative to the "input charge amount", impurity represents the value obtained by subtracting the "area % of the peak corresponding to PFTPA in the gas chromatography (GC) measurement results" from 100%, and isomers represents the "area % of the peak corresponding to the isomer in the gas chromatography (GC) measurement results".

[0083] Test Example 1

[0084] In Experimental Example 1, by using Figure 2 and Figure 3The PFTPA manufacturing apparatus and electrode plates shown in the figure were used for the test. Both the cathode electrode plate and the anode electrode plate used nickel (Ni) electrode plates, and the electrode plate area was 340 cm 2 . The temperature of the electrochemical reactor in which the ECF reaction occurs is maintained at 0°C to 5°C. For the ECF reaction, after initially injecting at a rate of 1 kg / hour through the inlet, TPA is circulated at a flow rate of 25 mL / minute while anhydrous hydrogen fluoride is circulated at a flow rate of 6 L / minute by using a circulation pump. Therefore, the concentration of TPA relative to anhydrous hydrofluoric acid is set to 10 wt%. Then, 15 mA / cm is applied to the electrode plate by using a rectifier (power supply). 2 A constant current was generated. After the reaction was carried out for about 24 hours, the PFTPA separated from the extraction layer was extracted from the solution separator. The PFTPA generated according to Experimental Example 1 was separated by using a solution separator and then subjected to a purification process.

[0085] And, as a result of measuring the resistivity value of the purified PFTPA, the resistivity value thereof was measured to be 3×10 4 ohm·cm. This is a fairly low resistivity, so it is a value that is difficult to use as a refrigerant for semiconductor manufacturing equipment, but it means that P FTPA contains a large amount of water.

[0086] To continue removing moisture, 0.03 wt% CaH2 was added to the PFTPA and then stirred. The stirrer speed was set to 300 rpm. After about 12 hours, after removing the precipitate, i.e., Ca(OH)2, the resistivity of the remaining PFTPA was measured again and its resistivity was measured to be 1×10 9 ohm·cm. It can be seen that the insulation properties of PFTPA are improved by removing moisture.

[0087] Test Example 2

[0088] In Experimental Example 2, PFTPA manufactured in the same manner as in Experimental Example 1 was used. In addition, 0.08 wt% of MgSO4 was added to PFTPA to remove moisture, and then stirred. The speed of the stirrer was set to 300 rpm. After about 12 hours, the resistivity of PFTPA was measured again, and its resistivity was measured to be 1×10 6ohm·cm. It can be seen that the insulation properties of PFTP A are improved by removing moisture. However, it can be seen that even if the amount of CaH2 input is greater than , the moisture removal efficiency is slightly low (the resistivity of PFTPA measured after removing moisture is less than that of Test Example 1). This is because, in the method using CaH2, CaH2 irreversibly removes moisture by chemical reaction with moisture, but in the method using MgSO4, MgSO4 combines with moisture in the form of a hydrate, and moisture may be reversibly desorbed by heat or the like.

[0089] Test Example 3

[0090] In Experimental Example 3, PFTPA manufactured in the same manner as in Experimental Example 1 was used. And, in order to remove moisture, a molecular sieve having pores 3A and 5A was put into the PFTPA solution and then stirred. The molecular sieve put in was treated in a vacuum at a temperature of 200°C for 3 hours, and was put in an amount equivalent to 1wt% of the PFTPA solution. After the putting in, stirring was performed at 100rpm. After stirring, the molecular sieve was separated from the PFTPA solution by filtering using a filter having pores of 0.45μm. And, as a result of measuring the resistivity of the filtered PFTPA solution, 1×10 9 ohm·cm. It can be seen that the insulation properties of PFTPA are improved by removing moisture.

[0091] The PFTPA solution before water removal by molecular sieve was subjected to gas chromatography analysis, and the area ratios of the cyclic isomer and other impurities were 3.1% and 1.7%, respectively (herein, the area ratio of the cyclic isomer refers to the area ratio (%) of the peak corresponding to the cyclic isomer in the gas chromatography measurement result, and the area ratio of other impurities is the value obtained by subtracting the area ratio (%) of the peak corresponding to PFTPA and the area ratio (%) of the peak corresponding to the cyclic isomer from 100%). In addition, the PFTPA after water removal by molecular sieve having pores 3A according to the above method was subjected to gas chromatography analysis, and the area ratios of the cyclic isomer and other impurities were 2.2% and 0.7%, respectively. In addition, the PFTPA after water removal by molecular sieve having pores 5A according to the above method was subjected to gas chromatography analysis, and the area ratios of the cyclic isomer and other impurities were 2.4% and 0.8%, respectively. Furthermore, regardless of the pore size, the weight of the PFTPA solution after removing water using the molecular sieves decreased by 6.1% to 7.4%.

[0092] It can be seen that when the molecular sieve is used to remove water, the cyclic isomers of PFTPA and other impurities can be removed together with the water. Thus, the purity of PFTPA can be further improved. However, in this process, part of the PFTPA solution may also be removed, thus having the disadvantage of slightly reducing the yield of PFTPA.

[0093] Although the present invention has been described in detail with reference to the preferred embodiments, the present invention is not limited to the above-described embodiments, and those skilled in the art can make various modifications within the scope of the technical idea of ​​the present invention.

[0094] Industrial Applicability

[0095] Can be used in PFTPA manufacturing industry.

Claims

1. A method for producing high-purity perfluorotripropylamine (PFTPA), comprising: A manufacturing step, wherein PFTPA is manufactured from a mixed solution of tripropylamine (TPA) and hydrogen fluoride (HF) using an electrochemical fluorination (ECF) method; a separation step, wherein the produced PFTPA is separated from a mixed solution of TPA and hydrogen fluoride; and A moisture removal step in which moisture included in the manufactured PFTPA is removed.

2. The manufacturing method according to claim 1, wherein: In the water removal step, water is removed by adding at least one of calcium hydride (CaH 2 ) and magnesium sulfate (MgSO 4 ) to the produced PFTPA and stirring the mixture.

3. The manufacturing method according to claim 1, wherein: In the moisture removal step, at least one of a molecular sieve having pores of a predetermined size and silica gel is added to the produced PFTPA and stirred to remove moisture.

4. The manufacturing method according to claim 1, further comprising: After the PFTPA separation step, the separated PFTPA is subjected to a purification step of a chemical purification process, In the water removal step, water included in the PFTPA purified in the purification step is also removed.

5. The manufacturing method according to claim 1, wherein: In the manufacturing step, PFTPA is manufactured by passing a mixed solution of TPA and hydrogen fluoride through a channel in forced convection, wherein the channel is a space between a plurality of cathode electrode plates and a plurality of anode electrode plates that are spaced apart at intervals of 3 mm to 5 mm and alternately arranged, wherein the flow rate of the mixed solution flowing through the channel is controlled to be 4 L / min to 10 L / min by considering the yield of the product, i.e., PFTPA, and the concentration of impurities included in the product.

6. A device for producing high-purity perfluorotripropylamine (PFTPA), comprising: An electrochemical reactor for generating PFTPA by applying electric energy to a mixed solution of tripropylamine (TPA) and hydrogen fluoride (HF) using an electrochemical fluorination method (ECF); a solution separator for separating the PFTPA solution from the mixed solution of TPA and hydrogen fluoride and the PFTPA solution discharged from the electrochemical reactor; and A moisture removal unit is used to remove moisture from the PFTPA discharged from the solution separator.

7. The manufacturing device according to claim 6, wherein: The moisture removal unit removes moisture by using at least one of calcium hydride (CaH 2 ) and magnesium sulfate (MgSO 4 ).

8. The manufacturing device according to claim 6, wherein: The moisture removal unit removes moisture by using at least one of a molecular sieve having pores of a predetermined size and silica gel.

9. The manufacturing apparatus according to claim 6, further comprising a purification unit for performing a chemical purification process on the PFTPA discharged from the solution separator. in, The moisture removal unit also removes moisture from the purified PFTPA discharged from the purification unit.

10. The manufacturing device according to claim 6, wherein: The electrochemical reactor comprises: Electrolyzer; an inlet for introducing a mixed solution of TPA and hydrogen fluoride into the electrolytic cell; an outflow port for discharging the product including PFTPA generated by the ECF reaction of the mixed solution from the electrolytic cell; and A plurality of cathode electrode plates and a plurality of anode electrode plates are spaced apart at intervals of 3 mm to 5 mm in the electrolytic cell and are alternately arranged. Wherein, the manufacturing device further comprises: a solution supplier that supplies the mixed solution to the electrolytic cell through the inlet; and A flow controller controls the flow of the mixed solution supplied by the solution supplier, which controls the flow by considering the yield of PFTPA and the concentration of the impurities, and controls the flow of the mixed solution flowing through the space, i.e., the channel, between the cathode electrode plate and the anode electrode plate to be 4 L / min to 10 L / min.

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