Method for manufacturing perfluoropolyether materials, and device thereof

Abstract

The present invention relates to a technology for manufacturing perfluoropolyether-based materials. A method for manufacturing a perfluoropolyether-based material according to one embodiment of the present invention comprises: Step A, in which a low molecular weight perfluoropolyether synthesis unit synthesizes a low molecular weight perfluoropolyether material using hexafluoropropylene oxide (HFPO) as a monomer, low-viscosity PFPE oil as a solvent, cesium fluoride (CsF) as a catalyst, and Diglyme as a polar solvent; and Step B, in which a high molecular weight perfluoropolyether synthesis unit synthesizes a high molecular weight perfluoropolyether material using hexafluoropropylene oxide (HFPO) as a monomer, the low molecular weight perfluoropolyether material as a solvent, cesium fluoride (CsF) as a catalyst, and Tetraglyme as a polar solvent.

Description

Technology Field

[0001] The present invention relates to a technology for manufacturing perfluoropolyether-based materials. Background Technology

[0003] By filling activated carbon with hexafluoropropylene oxide (HFPO) and maintaining it at room temperature for 3 days, an acid fluoride polymerized with hexafluoropropylene oxide with a molecular weight of 1000 or less can be synthesized. However, since it takes a long time to produce hexafluoropropylene oxide with a molecular weight of 1000 or less (e.g., more than 3 days), it has the disadvantage of not being suitable for mass production.

[0004] The method of using hexafluoropropene oxide, an organic polar solvent, and a metal fluoride to synthesize an acid fluoride polymerized with hexafluoropropene oxide has the problem of increasing the viscosity of the reactants. Although the viscosity inside the reactants can be lowered by adding hexafluoropropylene as a diluent, there is a risk that by-products will be generated when the reaction temperature rises above a certain level, causing a rapid increase in reaction temperature and pressure, and there are problems such as difficulty in recovering hexafluoropropylene and difficulty in utilizing the by-products.

[0005] When polymerizing hexafluoropropene oxide, the metal fluoride and solvent used are mixed with water, making it difficult to recover the raw materials and resulting in a problem of increased waste in the commercialization process. Additionally, the hexafluoropropylene oligomer synthesis method has disadvantages such as increased viscosity at low temperatures, the lack of other uses for the reactants other than as a diluent solvent, and increased production costs.

[0006] In order to produce conventional perfluoropolyethers, U.S. Patent No. 3,242,218 describes an acid fluoride product generated from the polymerization of hexafluoropropene oxide (HFPO) that is hydrolyzed with water to convert it into a perfluoropolyether carboxylic acid, and then a decarboxylation and neutralization reaction is performed by introducing fluorine gas for an extended period. Additionally, U.S. Patent No. 4,847,427 attempts to shorten the neutralization reaction time by adding a metal fluoride, such as NaF or KF, to the above process.

[0007] However, these processes involve a hydrolysis step that uses water during the process, which generates a large amount of waste and entails an unavoidable additional process for removing moisture. In Korean registered patent No. 10-1041601, a neutralization reaction was performed using fluorine metals such as aluminum fluoride (AlF3), antimony fluoride (SbF5), and cobalt fluoride (CoF3) without using fluorine gas, but since a process using water was required to separate the fluorine metals from the generated perfluoropolyether, an additional washing or distillation process was required. Prior art literature

[0009] U.S. Patent No. 3,242,218 - Process for preparing fluorocarbon polyethers U.S. Patent No. 4,847,427 - Process for preparing fluorocarbon polyethers Republic of Korea Patent Publication No. 10-1041601 - Method for neutralizing perfluoropolyethers The problem to be solved

[0010] The objective of the present invention is to solve the above-mentioned problems by providing a method for manufacturing a perfluoropolyether-based material and an apparatus for the same.

[0011] The present invention provides a manufacturing technology that minimizes the generation of fluorinated acids such as hydrofluoric acid (HF) and selectively removes small amounts of hydrofluoric acid or fluorinated acids without using water in the perfluoropolyether production process, thereby shortening the usage time of fluorine gas and ensuring process safety, while simultaneously maximizing the raw material efficiency of the process by utilizing by-products recovered from the distillation and drain processes as reusable raw materials through a high-efficiency recycling process.

[0012] And, it provides a manufacturing technology that ensures process safety and efficiency by selectively removing fluorinated acids, such as hydrofluoric acid (HF), which are generated as by-products during the production of perfluoropolyether, and neutralizing more than 99% of the perfluoropolyether acid terminal groups within a shortened time.

[0013] The present invention provides a manufacturing and regeneration technology that integrates the synthesis, neutralization, fluorination, and regeneration processes of perfluoropolyether (PFPE) into a single system, enabling a consistent process from the synthesis of low-molecular-weight PFPE to the recycling of waste oil.

[0014] The present invention provides an eco-friendly technology that can regenerate PFPE oil without a separate adsorbent or filter by chemically removing hydrofluoric acid and oxidative impurities, particularly by combining fluorine gas and cesium fluoride (CsF). means of solving the problem

[0016] To achieve the above objectives, a method for manufacturing a perfluoropolyether-based material according to one embodiment of the present invention comprises: Step A, in which a low molecular weight perfluoropolyether synthesis unit synthesizes a low molecular weight perfluoropolyether using hexafluoropropylene oxide (HFPO) as a monomer, low-viscosity PFPE oil as a solvent, cesium fluoride (CsF) as a catalyst, and Diglyme as a polar solvent; and Step B, in which a high molecular weight perfluoropolyether synthesis unit synthesizes a high molecular weight perfluoropolyether using hexafluoropropylene oxide (HFPO) as a monomer, the low molecular weight perfluoropolyether material as a solvent, cesium fluoride (CsF) as a catalyst, and Tetraglyme as a polar solvent.

[0017] In one embodiment, in step A, 0.01 to 1 mol% of linalool is added relative to the amount of hexafluoropropylene oxide (HFPO), and the reaction is carried out under conditions of a reaction temperature of 30 ℃, a stirring speed of 1000 rpm, and a reaction pressure of atmospheric pressure (1 atm abs), and the PFPE-COF solution is recovered after 1 hour.

[0018] In one embodiment, in step A, the PFPE-COF solution is subjected to vacuum distillation, water is added to the separated PFPE-COF to substitute the -COF functional group with a carboxylic acid (-COOH), fluorine gas (F2) is injected into the hydrolyzed PFPE-COOH solution, and cesium fluoride (CsF) is introduced to remove hydrofluoric acid (HF).

[0019] In one embodiment, in step B, the reaction temperature is maintained at -40℃, the stirring speed is maintained at 500 rpm, the reaction pressure is maintained at atmospheric pressure (1 atm abs), and the PFPE-COF solution is recovered after 3 hours.

[0020] In one embodiment, in step B, mixed fluorine gas is introduced into the PFPE-COF solution, and then 0.1 mol of cesium fluoride (CsF) is introduced and stirred at 500 rpm for 20 minutes.

[0021] In one embodiment, it further includes step C, which synthesizes a perfluoropolyether material by regenerating waste PFPE oil.

[0022] In one embodiment, in step C, primary distillation is carried out on the waste PFPE oil in a vacuum atmosphere while gradually increasing the temperature from room temperature to 70°C, and on the remaining PFPE oil, a mixed gas of F₂ and N₂ is injected while maintaining the temperature at 160°C, and then 0.1 mol of cesium fluoride (CsF) is added and stirred at 160°C for 20 minutes. Effects of the invention

[0024] By implementing the present invention, acid fluoride of hexafluoropropylene oxide polymerization with a molecular weight of 400 to 800 can be synthesized in a short time with a high yield, thereby reducing production costs.

[0025] In addition, since hexafluoropropylene is not used as a diluent, risks associated with the generation of byproducts and rapid pressure expansion can be eliminated. As the viscosity does not increase due to the low reaction temperature of the hexafluoropropylene oligomer, stirring can be made easier. Furthermore, by manufacturing a diluent based on hexafluoropropylene, space in the manufacturing facility can be saved during the commercialization process, the process line can be simplified, and production costs can be reduced.

[0026] In addition, the raw materials used for the acid fluoride in the hexafluoropropene oxide polymerization required for the manufacture of perfluoropolyether-based materials can be reused, and waste can be reduced. Furthermore, by neutralizing the acid fluoride from the hexafluoropropene oxide polymerization with fluorine gas and then selectively removing it with cesium fluoride, the usage time of fluorine gas can be shortened and process stability can be increased. By reusing the by-products recovered through distillation and drainage, raw material efficiency can be improved.

[0027] Furthermore, by using fluorine gas instead of adsorbents for perfluoropolyether waste, the problem of reduced regeneration rates caused by the adsorption of perfluoropolyether-based materials can be mitigated, and production costs can be reduced.

[0028] Furthermore, it is possible to provide a process that improves the manufacturing efficiency and regeneration yield of perfluoropolyether-based materials, shortens the usage time of fluorine gas, and minimizes waste generation. In addition, the series of processes according to the present invention can be implemented within a single device composed of a low molecular weight perfluoropolyether synthesis unit, a high molecular weight perfluoropolyether synthesis unit, a low molecular weight perfluoropolyether neutralization unit, and a perfluoropolyether waste regeneration unit, thereby enhancing the safety and economic efficiency of the process.

[0029] The present invention has the advantage of being a high-efficiency process that minimizes the loss of unreacted fluorine gas by improving the conversion rate and selectivity of fluorine gas through the direct reaction of fluorine gas with the acid fluoride produced by the polymerization of hexafluoropropene oxide (HFPO), thereby eliminating the generation of excess hydrofluoric acid (HF), fluorine acid, and wastewater caused by hydrolysis in conventional technology by not using water in the perfluoropolyether production process.

[0030] In addition, fluorinated acids such as HF, which are generated in trace amounts during the synthesis of perfluoropolyether, can be selectively removed using CsF (Cesium Fluoride) among metal fluorides. Since CsF is not mixed with the final product, perfluoropolyether, and is easy to separate, it has the advantage of being easily separated by filtering alone without a separate distillation or washing process.

[0031] Therefore, the separated perfluoropolyether can be used directly as a final product, and the cesium fluoride salt of CsF combined with HF and fluorinated acid can be easily separated and restored to CsF, HF, and fluorinated acid through heat treatment, thereby providing a manufacturing method and process that facilitates the reuse of the catalyst.

[0032] Furthermore, it is possible to provide a process that improves the manufacturing efficiency and regeneration yield of perfluoropolyether-based materials, shortens the usage time of fluorine gas, and minimizes waste generation. In addition, the series of processes according to the present invention can be implemented within a single device composed of a low molecular weight perfluoropolyether synthesis unit, a high molecular weight perfluoropolyether synthesis unit, a low molecular weight perfluoropolyether neutralization unit, and a perfluoropolyether waste regeneration unit, thereby enhancing the safety and economic efficiency of the process. Brief explanation of the drawing

[0034] FIG. 1 is a diagram showing the configuration of a manufacturing apparatus for a perfluoropolyether-based material according to one embodiment of the present invention. Figure 2 shows the synthesis process of a perfluoropolyether-based material. FIG. 3 is a diagram showing the composition of a low molecular weight perfluoropolyether synthesis unit in one embodiment of the present invention. FIG. 4 is a diagram showing the composition of a polymer perfluoropolyether synthesis unit in one embodiment of the present invention. FIG. 5 is a diagram showing the composition of a low molecular weight perfluoropolyether neutralization unit in one embodiment of the present invention. Figure 6 is a diagram showing the configuration of a perfluoropolyether waste recycling unit in one embodiment of the present invention. Specific details for implementing the invention

[0035] The present invention may be implemented with various modifications without departing from the spirit, and may have one or more embodiments. Furthermore, the embodiments described in the “specific details for implementing the invention” and “drawings,” etc., in the present invention are examples for specifically explaining the present invention and do not limit or restrict the scope of the rights of the present invention.

[0036] Accordingly, anything that a person skilled in the art to which the present invention pertains can easily deduce from the “specific details for carrying out the invention” and “drawings,” etc., of the present invention may be interpreted as falling within the scope of the present invention.

[0037] In addition, the size and shape of each component shown in the drawings may be exaggerated for the purpose of explaining the embodiments and do not limit the actual size and shape of the invention.

[0038] Unless specifically defined otherwise in the specification of the present invention, terms used therein may have the same meaning as generally understood by those skilled in the art to which the present invention pertains.

[0039] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0041] FIG. 1 is a diagram showing the configuration of a manufacturing apparatus for a perfluoropolyether-based material according to one embodiment of the present invention.

[0042] The manufacturing apparatus (100) for perfluoropolyether-based materials includes a low molecular weight perfluoropolyether synthesis unit (110), a high molecular weight perfluoropolyether synthesis unit (120), a low molecular weight perfluoropolyether neutralization unit (130), and a perfluoropolyether waste regeneration unit (140).

[0043] The low molecular weight perfluoropolyether synthesis unit (110) can produce an acid fluoride of hexafluoropropylene oxide (HFPO) polymerization with a molecular weight of 400 to 800. By using hexafluoropropylene oxide, a solvent, a metal fluoride, and a terpene, an acid fluoride of hexafluoropropylene oxide polymerization with a molecular weight of 400 to 800 can be synthesized.

[0044] The polymer perfluoropolyether synthesis unit (120) can synthesize a hexafluoropropylene oxide acid fluoride with a molecular weight of 2,000 to 8,000 by using a mixture of hexafluoropropylene oxide and a hexafluoropolyether with a molecular weight of 400 to 800 as a diluent solvent.

[0045] The low molecular weight perfluoropolyether neutralization unit (130) can neutralize perfluoropolyethers with a molecular weight of 400 to 800. Neutralization can be achieved by hydrolyzing the acid fluoride of pure hexafluoropropylene oxide polymerization to convert it into a carboxylic acid, and then neutralizing it with fluorine gas to minimize the fluorinated acid generated, and by removing a small amount of fluorinated acid with a fluoride metal.

[0046] The perfluoropolyether waste regeneration unit (140) can regenerate perfluoropolyether-based oils having properties in the range of Fomblin 16 / 06, Fomblin 25 / 06, and Krytox 1525. And perfluoropolyether-based wastes including moisture, degradable organic matter, oxidized low molecular weight perfluoropolyether, and oxidized gel form can be regenerated using fluorine gas without using an adsorbent.

[0047] Figure 2 shows the synthesis process of a perfluoropolyether-based material.

[0048] First, a mixed perfluoropolyether acyl fluoride (PFPE-COF) solution can be produced by reacting a solvent, a monomer, and a metal fluoride.

[0049] When water (H2O) is added to a mixed perfluoropolyether acyl fluoride solution to hydrolyze it, a solvent, a catalyst, fluoride acid, water, and a large amount of hydrogen fluoride (HF) may be released. Along with a large amount of hydrogen fluoride, perfluoropolyether carboxylic acid (PFPE-COOH) substituted with carboxyl groups may be produced.

[0050] When the produced perfluoropolyether carboxylic acid is distilled, hydrogen fluoride and water vapor are separated, so that some hydrogen fluoride can be removed from the perfluoropolyether carboxylic acid.

[0051] When a metal fluoride and fluorine gas are introduced into a perfluoropolyether carboxylic acid from which some hydrogen fluoride has been removed and reacted, a fluoride salt can be produced. Then, a perfluoropolyether-based material (PFPE-CF3) in which hydrogen fluoride is removed and substituted with the functional group CF3 can be produced.

[0052] FIG. 3 is a diagram showing the composition of a low molecular weight perfluoropolyether synthesis unit in one embodiment of the present invention.

[0053] A low molecular weight perfluoropolyether acyl fluoride reactor (111) can synthesize a low molecular weight perfluoropolyether acyl fluoride solution by mixing a solvent with a hexafluoropropylene oxide monomer, a terpene, and a metal fluoride.

[0054] The distiller (112) can distill a low molecular weight perfluoropolyether acyl fluoride solution to separate it into low molecular weight perfluoropolyether acyl fluoride or low molecular weight hexafluoropropylene oxide, a solvent, and a metal fluoride, respectively. The separated solvent and metal fluoride can be fed into a low molecular weight perfluoropolyether acyl fluoride reactor (111) and reused.

[0055] The hydrolysis reactor (113) can hydrolyze the acid fluoride of a low molecular weight perfluoropolyether acyl fluoride or hexafluoropropylene oxide polymerization to substitute it with a carboxyl group. At this time, a small amount of water may be introduced, and hydrogen fluoride may be discharged together.

[0056] The neutralization reactor (114) can neutralize the acid fluoride of a low molecular weight perfluoropolyether acyl fluoride or hexafluoropropylene oxide polymerization substituted with carboxyl groups by introducing fluorine gas to deoxidize the carboxyl groups. The neutralization point can be confirmed via FT-IR (Fourier-Transform Infrared Spectroscopy). Some hydrogen fluoride can be removed and discharged.

[0057] The hydrogen fluoride removal mixer (115) receives a perfluoropolyether-based material or hexafluoropropylene oxide and a fluoride metal, and can selectively remove hydrogen fluoride. The resulting fluoride salt can be fed into a low molecular weight perfluoropolyether acyl fluoride reactor (111) and reused. The fluoride metal may be, for example, cesium fluoride (CsF).

[0058] By carrying out this process, acid fluorides of hexafluoropropylene oxide polymerization with a molecular weight of 400 to 800 can be synthesized in a short time with high yield, thereby reducing production costs. In addition, through neutralization, a low molecular weight perfluoropolyether-based material that can be used in a cooling device can be manufactured.

[0059] FIG. 4 is a diagram showing the composition of a polymer perfluoropolyether synthesis unit in one embodiment of the present invention.

[0060] The perfluoropolyether acyl fluoride reactor (121) can produce a perfluoropolyether acyl fluoride solution by mixing a solvent, a low molecular weight perfluoropolyether, a hexafluoropropylene oxide monomer, and a metal fluoride. At this time, the low molecular weight perfluoropolyether is produced in the low molecular weight perfluoropolyether synthesis unit (110) and may be an acid fluoride of hexafluoropropylene oxide polymerization having a molecular weight of 400 to 800.

[0061] The distiller (122) can separate the solvent, perfluoropolyether acyl fluoride, and metal fluoride through distillation.

[0062] The solvent storage tank (123) can store the solvent separated from the distiller (122). The stored solvent can be fed into the perfluoropolyether acyl fluoride reactor (121) and reused.

[0063] Separated perfluoropolyether acyl fluoride, metal fluoride, and fluorine gas are introduced into the neutralization reactor (124), and low molecular weight perfluoropolyether-based material can be discharged. The low molecular weight perfluoropolyether-based material can be introduced into the perfluoropolyether acyl fluoride reactor (121) and reused. The neutralization reactor (124) can discharge perfluoropolyether-based material from which some hydrogen fluoride has been removed, or acid fluoride from hexafluoropropylene oxide polymerization.

[0064] The hydrogen fluoride removal mixer (125) receives a perfluoropolyether-based material, hexafluoropropylene oxide, or a fluoride metal and selectively removes hydrogen fluoride to produce an acid fluoride of polymerized perfluoropolyether-based material or hexafluoropropylene oxide polymerization having a molecular weight of 2,000 to 8,000. The fluoride salt produced at this time can be introduced into a perfluoropolyether acyl fluoride reactor (121) and reused. The fluoride metal may be, for example, cesium fluoride (CsF).

[0065] Since hexafluoropropylene is not used as a diluent, risks associated with the generation of byproducts and rapid pressure expansion can be eliminated. Additionally, because the viscosity does not increase due to the low reaction temperature of the hexafluoropropylene oligomer, stirring becomes easier. Furthermore, by manufacturing the diluent based on hexafluoropropylene, space in the manufacturing facility can be saved during the commercialization process, the process line can be simplified, and production costs can be reduced.

[0066] FIG. 5 is a diagram showing the composition of a low molecular weight perfluoropolyether neutralization unit in one embodiment of the present invention.

[0067] The acid fluoride of the hexafluoropropylene oxide polymerization is hydrolyzed to convert it into a perfluoropolyether carboxylic acid, and then neutralized by decarboxylation by introducing fluorine gas for a long time, or the time of the neutralization reaction is shortened by adding fluoride metals such as sodium fluoride (NaF) and potassium fluoride (KF). However, according to the above process, a large amount of waste is generated, and a process to remove moisture must be carried out.

[0068] Although a neutralization reaction can be carried out using fluoride metals such as aluminum fluoride (AlF3), antimony fluoride (SbF5), and cobalt fluoride (CoF3) without using fluorine gas, there is a disadvantage that an additional washing or distillation process is required to separate the produced perfluoropolyether material from the fluoride metal.

[0069] In one embodiment of the present invention, a manufacturing method is provided that can neutralize the acid terminal groups of 99% or more of a perfluoropolyether-based material by selectively removing hydrogen fluoride generated as a byproduct when manufacturing a perfluoropolyether-based material.

[0070] First, the low molecular weight perfluoropolyether acyl fluoride reactor (131) can produce a low molecular weight perfluoropolyether acyl fluoride solution by mixing a solvent, a hexafluoropropylene oxide monomer, and a metal fluoride. At this time, a small amount of terpene may be added.

[0071] The distiller (132) can distill a low molecular weight perfluoropolyether acyl fluoride solution to separate it into low molecular weight perfluoropolyether acyl fluoride or low molecular weight hexafluoropropylene oxide, a solvent, and a metal fluoride, respectively. The separated solvent and metal fluoride can be fed into a low molecular weight perfluoropolyether acyl fluoride reactor (131) and reused.

[0072] The hydrolysis reactor (133) can hydrolyze the acid fluoride of a low molecular weight perfluoropolyether acyl fluoride or hexafluoropropylene oxide polymerization to substitute it with a carboxyl group. At this time, a small amount of water may be introduced, and hydrogen fluoride may be discharged together.

[0073] The neutralization reactor (134) can neutralize the acid fluoride of a low molecular weight perfluoropolyether acyl fluoride or hexafluoropropylene oxide polymerization substituted with carboxyl groups by introducing fluorine gas to deoxidize the carboxyl groups. The neutralization time can be confirmed via FT-IR. Some hydrogen fluoride can be removed and discharged.

[0074] The hydrogen fluoride removal mixer (135) can selectively remove hydrogen fluoride by receiving a perfluoropolyether-based material or hexafluoropropylene oxide and a fluoride metal. The resulting fluoride salt can be fed into a low molecular weight perfluoropolyether acyl fluoride reactor (31) and reused. The fluoride metal may be, for example, cesium fluoride (CsF).

[0075] The low molecular weight perfluoropolyether neutralization unit (130) can reuse the raw materials used in the acid fluoride of the hexafluoropropene oxide polymerization required for the manufacture of perfluoropolyether-based materials, and can reduce waste. In addition, by neutralizing the acid fluoride of the hexafluoropropene oxide polymerization with fluorine gas and then selectively removing it with cesium fluoride (CsF), the usage time of the fluorine gas can be shortened and the stability of the process can be increased. Furthermore, raw material efficiency can be improved by allowing the by-products recovered through distillation and drainage to be reused.

[0076] Figure 6 is a diagram showing the configuration of a perfluoropolyether waste recycling unit in one embodiment of the present invention.

[0077] To regenerate vacuum pump oil, which is a waste product of perfluoropolyethers used in semiconductor devices, moisture and impurities can be removed using activated carbon and filters. However, beyond selectively removing moisture and impurities, activated carbon and filters also adsorb the perfluoropolyether-based material intended for regeneration, which may result in a low recovery rate of the regenerated perfluoropolyether-based material.

[0078] In a specific example of the present invention, the perfluoropolyether waste regeneration unit (140) can regenerate perfluoropolyether-based oil having physical properties in the range of Fomblin 16 / 06, Fomblin 25 / 06, and Krytox 1525.

[0079] The primary distiller (141) can separate perfluoropolyether-based waste containing moisture, decomposable organic matter, oxidized low molecular weight oil, and oxidized gel form by distilling. It can also separate perfluoropolyether-based material, oxidized low molecular weight perfluoropolyether, oxidized gel form perfluoropolyether, and solid powder by distilling at high temperature.

[0080] Storage (142) can store moisture and decomposable organic matter separated by the primary distiller (141).

[0081] The neutralization reactor (143) receives perfluoropolyether-based material, oxidized low molecular weight perfluoropolyether, and fluorine gas, and can discharge the neutralized perfluoropolyether-based material. It can also discharge hydrogen fluoride with some of it removed.

[0082] The hydrogen fluoride removal mixer (144) receives the neutralized perfluoropolyether-based material, hydrogen fluoride, and metal fluoride, and can remove the hydrogen fluoride and discharge the perfluoropolyether-based material.

[0083] The secondary distiller (145) can distill a low-viscosity perfluoropolyether-based material and then introduce the low-molecular-weight perfluoropolyether-based material into the low-molecular-weight perfluoropolyether synthesis unit (110) to synthesize cooling oil. Then, the high-molecular-weight perfluoropolyether-based material can be introduced into the high-molecular-weight perfluoropolyether synthesis unit (120) to synthesize oil used in a vacuum pump.

[0084] Accordingly, by not using adsorbents and filters, the problem of reduced regeneration rates caused by the adsorption of perfluoropolyether-based materials is mitigated, and production costs can be reduced.

[0086] The following describes examples of a synthesis process for low molecular weight perfluoropolyether, a synthesis process for high molecular weight perfluoropolyether, and a recycling process for perfluoropolyether waste in one embodiment of the present invention.

[0088] < Example 1 >

[0089] In Example 1, a low molecular weight PFPE-acyl fluoride (PFPE-COF) solution was synthesized using a low molecular weight perfluoropolyether synthesis unit (110). The reaction was carried out in a jacketed stirred reactor (111, capacity 3L) made of SUS316 material, which is resistant to internal corrosion. Cooling water was circulated through the outer jacket of the reactor (111) to enable precise temperature control within a range of ±0.5 ℃.

[0090] Chemours' GPL101 (viscosity of approximately 17.4 cSt at 25 °C), a low-viscosity PFPE oil, was used as the solvent, and 99.9% cesium fluoride (CsF, 99.9%, Alfa Aesar) was used as the catalyst. Additionally, Diglyme (Diethylene glycol dimethyl ether, 99%) was added as a polar solvent.

[0091] Hexafluoropropylene oxide (HFPO) was used as the monomer and injected using a continuous injection method (e.g., continuous gas injection for 1 hour). To prevent spontaneous polymerization of the monomer at the beginning of the reaction, linalool (C 10 H 18O, monoterpene alcohols (bp 217 °C) was added as a polymerization inhibitor terpene. The content of linalool used in the present invention is 0.01 to 1 mol% relative to the amount of monomer (e.g., HFPO) added, preferably 0.05 to 0.5 mol%, and more preferably 0.03 to 0.3 mol%. By adding a small amount of terpene in this manner, as described below, excessive radical reactions during the HFPO polymerization process can be suppressed, thereby allowing for the selective synthesis of low molecular weight perfluoropolyethers (PFPE) within the target molecular weight range.

[0092] Monomer (HFPO) and terpene were simultaneously introduced into the reactor (111) through a gas-liquid mixed supply line. The reaction temperature was maintained at 30°C, and the stirring speed was set to 1000 rpm. The reaction was carried out under atmospheric pressure (1 atm abs), and after 1 hour, the reaction was terminated and the product was recovered from the reactor.

[0093] The recovered product was analyzed using gel permeation chromatography (GPC, solvent: THF, Waters instrument). The results confirmed an average molecular weight (Mw) of approximately 600, indicating that the target low-molecular-weight PFPE-COF was successfully synthesized. Gas chromatography (GC, Agilent, FID detector) analysis also showed a distribution of low-molecular-weight components similar to the GPC results. Furthermore, Fourier-transform infrared spectroscopy (FT-IR, Thermo, ATR mode) analysis revealed the formation of acyl fluoride groups (-COF) at the terminals of the generated PFPE at 1880 cm⁻¹. -1 The C=O absorption peak in the vicinity was confirmed.

[0094] Afterward, the product was vacuum distilled to recover and separate the polar solvent and metal fluoride (CsF) used in the reaction. The separated solvent and catalyst were then fed back into a low-molecular-weight PFPE-COF reactor (111) for reuse.

[0095] The separated PFPE-COF solution was sent to a hydrolysis reactor (113) and the terminal -COF functional group of PFPE was replaced with a carboxylic acid (-COOH) by adding a small amount of water (H2O). During the hydrolysis process, a large amount of HF was generated and discharged from the reaction system.

[0096] Next, fluorine gas (F2) was injected into the PFPE solution hydrolyzed in the neutralization reactor (114) to perform a full fluorination reaction. As a result of FT-IR analysis, 1880 cm⁻¹ was obtained after fluorination treatment. -1 It was possible to see that the nearby C=O absorption peak was completely eliminated, indicating that the carboxyl group at the PFPE terminal was completely converted to a trifluoromethyl group (-CF3).

[0097] Additionally, GC analysis was performed to confirm that the terpene linalool component used prior to the neutralization reaction was completely decomposed and removed through the fluorination process. As a result, the peak corresponding to linalool (retention time approximately 5.3 minutes) was not detected in the sample after the reaction. This proves that all terpene components in the reaction system were fluorinated and removed.

[0098] Finally, CsF was reintroduced into the reaction product in a hydrogen fluoride removal mixer (115) to neutralize and remove the hydrofluoric acid (HF) generated during the fluorination reaction. For example, CsF can be reintroduced at a ratio of 0.01 to 1 mol% relative to PFPE (preferably 0.1 mol%) and stirred at 160°C and 500 rpm for 15 minutes. After treatment, the pH of the solution was measured and found to be neutral at pH 7, confirming that CsF effectively removed the residual HF in the product.

[0099] Through the above series of processes, the process from the synthesis of low molecular weight PFPE to the removal of hydrofluoric acid was carried out as a continuous process, and it was confirmed that the generated low molecular weight PFPE could be used as a cooling oil in the future.

[0101] < Example 2 >

[0102] In Example 2, polymer PFPE-COF was synthesized using a polymer perfluoropolyether synthesis unit (120). The PFPE-COF reactor (121) used was a 3L jacketed stirred reactor made of SUS316 material, just like in Example 1, and cooling water and low-temperature brine were circulated in the jacket (e.g. -40 ℃) to control the temperature within a range of ±0.5 ℃.

[0103] As a solvent, low molecular weight PFPE (Mw approx. 600, viscosity approx. 1.5 cSt at 20°C) prepared in Example 1 was used. As a catalyst, CsF (99.9%, Alfa Aesar) was used, and as a polar solvent, tetraglyme (Tetraethylene glycol dimethyl ether, Tetraglyme, 99%) was used.

[0104] HFPO was introduced as the reactant monomer via a continuous gas-phase injection method. (In this embodiment, no additional polymerization inhibitor was used.) The monomer was introduced into the reactor (121) through a separate dedicated line.

[0105] The reaction temperature was maintained at -40 ℃, and the reaction time was extended to 3 hours. The stirring speed was maintained at 500 rpm, and the reaction was carried out under atmospheric pressure (1 atm abs). After 3 hours, the reaction was terminated and the product was recovered.

[0106] GPC analysis confirmed that the average molecular weight (Mw) of the generated PFPE-COF sample was approximately 8,000, indicating that the target high molecular weight PFPE was successfully produced. Additionally, FT-IR (ATR mode) analysis at 1880 cm⁻¹ -1The C=O absorption peak of PFPE-COF appeared nearby, reconfirming the presence of acyl fluoride terminal groups in the synthesized polymer PFPE.

[0107] Next, a PFPE-COF solution synthesized with a low molecular weight perfluoropolyether neutralization unit (130) was transferred to perform a pre-fluorination process. Specifically, a mixed fluorine gas of F₂ / N₂ = 20% : 80% was introduced into a neutralization reactor (134) for 2 hours while maintaining an internal temperature of 160°C.

[0108] After removing the sample following the reaction, the FT-IR spectrum was measured, and the result was 1880 cm⁻¹. -1 It was confirmed that the nearby C=O peak had completely disappeared. This means that all PFPE terminal groups having acyl fluoride groups (-COF) were decarboxylated to -CF₃ groups and total-fluorinated.

[0109] When the pH of the product was measured after fluorination treatment, it showed a weak acidity of about pH 4, indicating that a small amount of fluorinated acid (HF, etc.) was generated and remained during the reaction process.

[0110] After transferring the sample to a hydrogen fluoride removal mixer (135), cesium fluoride (CsF) equivalent to 0.1 mol in PFPE-COF was added and stirred at 500 rpm for 20 minutes. At this time, the temperature can be set, for example, to 160 ℃. Afterward, the sample was recovered and the pH was re-measured, and it was confirmed that it had returned to a completely neutral pH of 7. This shows that CsF selectively adsorbed and neutralized the trace amounts of HF and other fluoro acids generated in the sample after pre-fluoridation treatment.

[0111] Through the above process, Mw High molecular weight PFPE of the 8000 level was stably synthesized, and in this process, the low molecular weight PFPE of Example 1 was utilized as a reaction solvent to implement a continuous process. As a result, it was confirmed that both the solvent for synthesizing low molecular weight PFPE and the high molecular weight PFPE product were efficiently manufactured by the process of the present invention.

[0113] < Example 3 >

[0114] In Example 3, a regeneration experiment of PFPE oil discarded after use in a semiconductor manufacturing process was performed using a perfluoropolyether waste regeneration unit (140).

[0115] The device was composed of a 3L capacity jacketed stirred primary distiller (141) made of SUS316 material, and the distillation temperature was precisely controlled (±0.5 ℃) by circulating a heat medium through the jacket. First, primary distillation was carried out in a vacuum atmosphere while gradually increasing the temperature from room temperature to 70 ℃. During this process, moisture, low molecular weight organic matter, and acidic impurities contained in the waste PFPE were evaporated and separated. Condensate and volatile components generated during distillation were collected and recovered in a separate storage (142) container. After the primary distillation, some peroxides and high molecular weight organic impurities still remained in the remaining PFPE, and the residue was transferred to a neutralization reactor (143) to remove them.

[0116] A total fluorination reaction was performed by injecting an F₂ / N₂ mixed gas (fluorine gas concentration of 20 vol% or more) while maintaining the internal temperature of the neutralization reactor (143) at 160 ℃. As the reaction proceeded, oxidized organic impurities such as peroxides remaining in the PFPE were decomposed and fluorinated, and FT-IR (ATR mode) analysis confirmed that all characteristic peaks attributable to impurities had disappeared.

[0117] The pH of the recycled PFPE sample obtained after the completion of the fluorination reaction was measured to be approximately 4, indicating that it contained a small amount of hydrofluoric acid generated during the reaction. The sample was immediately transferred to a hydrogen fluoride removal mixer (144), and CsF powder (99.9%) was added to the PFPE residue at a ratio of 0.1 mol. The mixer (144) was stirred at 160°C for 20 minutes to adsorb and neutralize acidic components such as HF and fluorocarboxylic acids generated during the reaction. After treatment, the pH of the sample was measured and confirmed to be neutral at pH 7. This means that CsF effectively removed the fluorinated acids generated during the fluorination reaction and completely neutralized them. When the amount of recycled PFPE was measured, a recovery rate of approximately 95% by weight from the waste was obtained.

[0118] The PFPE oil, having been regenerated in this way, was sent to a secondary distiller (145) to perform final fractional distillation. The secondary distiller (145) can perform vacuum distillation, for example, at 5 to 10 mmHg and 80 to 200°C. As a result of the distillation, the primary distillate, which first captured relatively volatile components, was recovered as a transparent, colorless liquid with a viscosity of about 10 cSt at 20°C, which is evaluated as low-viscosity PFPE at the level of heat transfer oil for cooling media.

[0119] Meanwhile, the distillation residue remaining in the secondary distiller was recovered as a liquid exhibiting a viscosity of about 60 cSt at 20 ℃, and it was confirmed that this was regenerated into high-viscosity PFPE that can be used as vacuum pump oil.

[0120] Through Example 3 above, it can be seen that the waste regeneration process of the present invention can effectively purify waste PFPE oil by removing impurities and acid products without using any adsorbents such as activated carbon or filters. In addition, it was confirmed that the recycling of waste resources and the creation of added value are possible by classifying and recovering the regenerated PFPE oil into low-viscosity cooling oil and high-viscosity vacuum pump oil, respectively.

[0122] Although embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. Various modifications may be made within the scope of the detailed description of the invention and the attached drawings, provided that such modifications do not depart from the spirit of the invention and do not impair its effects. Furthermore, it is obvious that such embodiments fall within the scope of the present invention. Explanation of the symbols

[0124] 100: Manufacturing apparatus for perfluoropolyether-based materials 110 : Low molecular weight perfluoropolyether synthesis unit 120 : Polymer perfluoropolyether synthesis unit 130: Low molecular weight perfluoropolyether neutralization unit 140 : Perfluoropolyether Waste Recycling Division

Claims

Claim 1 A method for preparing a perfluoropolyether-based material from a hexafluoropropylene oxide (HFPO) monomer, comprising: Step A, introducing a solvent, HFPO, linalool, and a metal fluoride into a first reactor and stirring to produce a reaction mixture containing a perfluoropolyether acyl fluoride (PFPE-COF) having an acyl fluoride group (-C(=O)F) at the terminal end; Step B, distilling the reaction mixture produced in Step A in a first distiller to separate the PFPE-COF produced in Step A from the solvent and the metal fluoride; Step C, introducing water and the PFPE-COF separated in Step B into a second reactor to produce a perfluoropolyether (PFPE-COOH) in which the acyl fluoride group (-C(=O)F) of the PFPE-COF separated in Step B is substituted with a carboxyl group (-COOH); and introducing fluorine (F₂) gas and the material produced in Step C into a third reactor. Step D, which involves adding PFPE-COOH to produce a first perfluoropolyether (PFPE-CF₃) in which the carboxyl group (-COOH) of the PFPE-COOH produced in Step C is substituted with a fluorinated terminal group (-CF₃); Step E, comprising introducing a metal fluoride and the first PFPE-CF₃ generated in Step D into a first mixer, neutralizing and removing the hydrofluoric acid (HF) generated in Step C or Step D, and obtaining the first PFPE-CF₃; Step F, comprising introducing HFPO, the first PFPE-CF₃ obtained in Step E, a polar auxiliary solvent, and a metal fluoride into a fourth reactor and stirring to produce a reaction mixture containing a perfluoropolyether acyl fluoride (PFPE-COF) having an acyl fluoride group (-C(=O)F) at the terminal; Step G, comprising distilling the reaction mixture generated in Step F in a second distiller to separate the PFPE-COF generated in Step F from the solvent and the metal fluoride;A method for preparing a perfluoropolyether-based material, comprising: a step H in which fluorine (F₂) gas, PFPE-COF separated in step G, and a metal fluoride are introduced into a fifth reactor, and a second perfluoropolyether (PFPE-CF₃) is produced in which the terminal group (-C(=O)F) of the PFPE-COF separated in step G is substituted with a fluorinated terminal group (-CF₃); and a step I in which a metal fluoride and the second PFPE-CF₃ produced in step H are introduced into a second mixer, and the hydrofluoric acid (HF) generated in step H is neutralized and removed to obtain the second PFPE-CF₃; wherein, in step A, 0.01 to 1 mol% of linalool is added relative to the amount of HFPO introduced, and the reaction is carried out for 1 hour under conditions of a reaction temperature of 30 ℃, a stirring speed of 1000 rpm, and a reaction pressure of atmospheric pressure (1 atm abs). Claim 2 delete Claim 3 A method for manufacturing a perfluoropolyether-based material according to claim 1, wherein the fluoride metal in steps A, B, and E is each cesium fluoride (CsF). Claim 4 A method for producing a perfluoropolyether-based material according to claim 1, wherein in step F, the reaction is carried out for 3 hours under conditions of a reaction temperature of -40 ℃, a stirring speed of 500 rpm, and a reaction pressure of atmospheric pressure (1 atm abs). Claim 5 A method for manufacturing a perfluoropolyether-based material according to claim 4, wherein the fluoride metal in steps F, G, H, and I is each cesium fluoride (CsF), and in step I, 0.1 mol% of cesium fluoride (CsF) is added and stirred at 500 rpm for 20 minutes. Claim 6 delete Claim 7 delete

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