Preparation method of high-yield perfluoroamine

Abstract

The invention provides a preparation method of high-yield perfluoroamine, and belongs to the technical field of fluorine-containing fine chemical engineering. Comprising two steps of raw material mixing and electric fluorination reaction, and post-treatment and purification. The method comprises the following steps: firstly, mixing a mixture of a low-boiling-point carbon compound and a high-boiling-point amine compound with anhydrous hydrogen fluoride in an electrolytic bath, and starting an electric fluorination reaction; in the post-treatment stage, the target perfluoroamine compound is separated and purified through multi-step washing, layering, alkaline hydrolysis, rectification and microfiltration. The method is simple in process, high in yield, high in product purity and suitable for industrial production.

Description

Technical Field

[0001] The invention relates to the technical field of fluorine-containing fine chemicals, in particular to a method for preparing high-yield perfluoroamine. Background Art

[0002] Perfluoroamine compounds are an important class of fluorinated organic compounds, which are widely used in many fields due to their excellent chemical stability, high temperature resistance, hydrophobicity and oleophobicity, and low surface energy. Specifically, perfluoroamine compounds can be used as the core component of surfactants to produce special coatings that are resistant to oil and water; in the pharmaceutical field, their derivatives are used as key intermediates to develop antiviral drugs, anti-tumor drugs and diagnostic agents; in addition, these compounds are also used to prepare high-performance lubricants, high-efficiency fuel additives and electronic chemical materials.

[0003] For example, Chinese patent application number CN201310066496.8 discloses a method for continuous production of perfluorotripropylamine, comprising the following steps: (1) filling a fluorination reactor with fillers and introducing a fluorine mixed gas for fluorination; (2) adding tripropylamine to a tripropylamine vaporizer through a feeder; (3) introducing nitrogen into the tripropylamine vaporizer to dilute the tripropylamine vapor and continuously introduce it into the fluorination reactor; (4) continuously introducing a fluorine-nitrogen mixed gas into the fluorination reactor to react with the diluted tripropylamine vapor mixed gas continuously introduced into the fluorination reactor, and collecting the reaction product; (5) alkali washing, water washing, and distillation purification of the reaction product to obtain perfluorotripropylamine.

[0004] However, the preparation technology of perfluoroamine compounds has significant bottlenecks, which are mainly reflected in the following aspects: Difficulty in selecting raw materials and controlling reaction conditions: The preparation of perfluoroamines usually adopts electrofluorination technology, but the low-boiling point carbon compounds and amine compounds used in the prior art have low selectivity in the reaction process, often generating a variety of by-products, resulting in a decrease in the yield of the target product.

[0005] Equipment corrosion is a prominent problem during the reaction process: Since highly corrosive anhydrous hydrogen fluoride is used in the electrofluorination reaction, the corrosion resistance of conventional reaction equipment is insufficient, which affects the stability and safety of the process.

[0006] The post-processing process is complicated and costly: the mixture obtained after the electrofluorination reaction usually contains hydrogen fluoride, unreacted raw materials and complex by-products. The existing technology mostly uses multi-step extraction or distillation for separation and purification, which is not only complicated, but also leads to increased energy consumption, affecting the economic efficiency of industrial production.

[0007] Environmental and safety issues: The processing of anhydrous hydrogen fluoride and the disposal of by-products involve great risks and are prone to cause environmental pollution and safety accidents, which places higher demands on the greening and safety of production processes.

[0008] In response to the above problems, researchers have conducted many explorations. For example, by optimizing the electrofluorination reaction conditions (such as voltage, current density, temperature, etc.) to improve the selectivity and yield of the target product; using more efficient separation and purification technologies to improve product purity; and developing electrolytic cell materials with higher corrosion resistance to deal with the corrosion problem of hydrogen fluoride. However, these improvements are mostly concentrated in a certain link of the process, and have not yet formed an overall optimized solution, which cannot effectively solve the problems of low yield, insufficient purity and high economic cost. Summary of the invention

[0009] Based on this, the present invention proposes an optimized method for preparing perfluoroamines, which not only significantly improves the yield and purity of the target product, but also reduces the process complexity and production cost through precise raw material ratio, electrofluorination process optimization and efficient post-processing step design. At the same time, the use of advanced anti-corrosion equipment and environmental protection treatment measures improves the industrial feasibility and safety of the process.

[0010] The invention provides a more efficient, economical and green solution for the preparation of perfluoroamine compounds, and has important industrial application value. Another object of the invention is to provide a perfluoroamine compound prepared by the above method.

[0011] To achieve this object, the present invention adopts the following technical solutions: A method for preparing a high-yield perfluoroamine comprises the following steps: Step 1: Raw material mixing and electrofluorination reaction: 1-3 parts by weight of a low-boiling-point carbon compound and 6-12 parts by weight of a high-boiling-point amine compound are mixed and added to an electrolytic cell, and 6-10 parts by weight of anhydrous hydrogen fluoride are added and fully mixed with the mixture; an electrofluorination reaction is initiated under set conditions, and the reaction lasts for 3-6 hours to generate a mixed reaction liquid; Step 2: Post-treatment washing: The mixed reaction liquid is washed several times with deionized water at a volume of 2-5 times the total volume of the reaction liquid to remove water-soluble impurities, and then the reaction liquid is washed with alkaline solution for 3-5 times, each time with an amount of 15%-25% of the volume of the mixed liquid, to remove residual hydrogen fluoride, and the washed mixed liquid is allowed to stand for 20-40 minutes to allow it to naturally separate into layers; Step 3: Purification: The organic phase rich in the target product is separated and transferred to an alkaline hydrolysis kettle, and alkaline hydrolysis is performed at a set temperature for 2-5 hours. The product after alkaline hydrolysis is introduced into a distillation column, and distilled at 100-200° C., the target product fraction is collected, and the distillation product is filtered through a modified microfiltration membrane with a pore size of 0.2-0.45 μm to obtain a pure perfluoroamine compound.

[0012] In some embodiments, the low boiling point carbon compound is selected from one or a combination of triethylamine, butyryl fluoride, and N-methylmorpholine.

[0013] In some embodiments, the high boiling point amine compound is selected from one or a combination of methylamine, ethylamine, dimethylamine, tripropylamine, tributylamine, and tripentylamine.

[0014] In some embodiments, the electrofluorination reaction conditions are: voltage 30-45V, current density 10-25 A / m², temperature -5 to 15°C.

[0015] In some embodiments, the alkali solution is selected from at least one of sodium bicarbonate and sodium hydroxide, and the mass concentration is 10-20%.

[0016] In some embodiments, the alkaline hydrolysis agent in the alkaline hydrolysis kettle is a methanol solution of sodium hydroxide or potassium hydroxide, and the concentration of the alkaline hydrolysis agent is 20-45wt%.

[0017] In some embodiments, the alkaline hydrolysis temperature is 80-120°C.

[0018] In some embodiments, the reflux ratio of the distillation column ranges from 3-5:1.

[0019] In some embodiments, the modified microfiltration membrane is a silane-based loaded ionic liquid microfiltration membrane, and the preparation method thereof comprises the following steps: The microfiltration membrane loaded with ionic liquid is placed in a plasma device, and a mixed gas of allyl (diethylamino) dimethylsilane vapor and ammonia gas in a volume ratio of 0.02-0.2:1-2 is used for plasma modification treatment; the power range is set to 100-200W, the frequency is controlled between 10-20MHz, the gas flow rate is maintained at 20-40ml / min, and the discharge time is continued for 200-300 seconds, thereby obtaining a microfiltration membrane loaded with ionic liquid with silane groups.

[0020] In some embodiments, the preparation method of the ionic liquid loaded microfiltration membrane is: Weigh the raw materials according to specific proportions, as follows: 1-allyl-3-butyl imidazole tetrafluoroborate (CAS No.: 863498-32-2), weigh 0.05 to 0.5 parts; Dimethylformamide (DMF) is used as a solvent, measured at 200 to 300 parts; 2-(Trifluoromethyl)pyrimidine-4,5-diamine (CAS No.: 1023817-05-1), weigh between 0.03 and 0.3 parts; A microfiltration membrane, measuring 20 to 40 parts, selected from at least one of polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE); Triethylamine, used as a catalyst, measured in 2 to 5 parts; After all the components are mixed, they are stirred at 60 to 70° C. for 100 to 150 minutes to ensure sufficient reaction; then, the mixture is filtered and the product is dried naturally; finally, an ionic liquid-loaded microfiltration membrane is obtained.

[0021] Reaction mechanism: First, 1-allyl-3-butyl imidazole tetrafluoroborate and 2-(trifluoromethyl)pyrimidine-4,5-diamine were impregnated on the microfiltration membrane. Under the action of plasma gas ammonia, amine groups were introduced into the microfiltration membrane, and then amino-allyl addition reactions were carried out with 1-allyl-3-butyl imidazole tetrafluoroborate and allyl (diethylamino) dimethylsilane respectively under the catalysis of ammonia.

[0022] At the same time, the amino group of 2-(trifluoromethyl)pyrimidine-4,5-diamine can also undergo amino-allyl addition reaction with 1-allyl-3-butylimidazolium tetrafluoroborate and allyl(diethylamino)dimethylsilane, respectively, to obtain microfiltration membranes grafted with (trifluoromethyl)pyrimidine, silane, and imidazole tetrafluoroborate.

[0023] Technical effects: This application significantly improves the selectivity of the target product perfluoroamine, reduces the generation of by-products, and makes the yield of perfluoroamine reach more than 90%, while the purity reaches more than 99%, meeting the needs of high-end applications. It is explained from the perspectives of molecular structure, spatial structure and similar miscibility as follows: The chemical stability and biological activity of the compound are enhanced by introducing functional groups such as trifluoromethyl and silane. The introduction of these functional groups changes the electron cloud distribution of the compound, thus affecting its chemical reactivity and physical properties.

[0024] The grafted microfiltration membrane has a larger surface area and more active sites, which helps to improve filtration efficiency and adsorption capacity. At the same time, due to the spatial effect of functional groups such as trifluoromethyl, the microfiltration membrane can more effectively identify and remove impurities during the filtration process.

[0025] According to the principle of like dissolves like, compounds with the same or similar functional groups are more likely to dissolve or adsorb each other. In this reaction, since the microfiltration membrane has been grafted with functional groups similar to the target product (such as trifluoromethyl), it is easier to adsorb and filter out impurities containing these functional groups, thereby improving the purity of the target product.

[0026] In summary, the microfiltration membrane grafted with (trifluoromethyl) pyrimidine, silane, and imidazole tetrafluoroborate exhibits excellent technical effects in filtering impurities in perfluoroamines and improves purity.

[0027] In addition, this method designs a multi-step washing, alkaline hydrolysis, distillation and microfiltration process with clear steps and significant effects, achieving efficient separation and purification of perfluoroamines; the optimized process reduces the complex separation and extraction steps in the traditional process, reduces production energy consumption and economic costs, and the overall process is highly stable and suitable for large-scale industrial applications. DETAILED DESCRIPTION

[0028] The technical scheme of the present invention is further described below by specific embodiments. Those skilled in the art should understand that the specific embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention. Unless otherwise specified, the technical means used in the following examples are conventional means well known to those skilled in the art, and the raw materials used are all commercially available conventional commodities.

[0029] Embodiment 1: Mix 1g of triethylamine and 10g of tributylamine and add them to the electrolytic cell, then add 8g of anhydrous hydrogen fluoride and mix thoroughly. Start the electrofluorination reaction at a voltage of 35V, a current density of 15 A / m², and a temperature of 10°C for 4 hours. After the reaction is completed, wash with deionized water 3 times the total amount of the reaction solution, and then wash with a 20% mass concentration of sodium hydroxide solution 3 times, each time using 20% ​​of the volume of the mixed solution. After standing for 30 minutes, separate the organic phase and transfer it to an alkaline hydrolysis kettle containing 35wt% sodium hydroxide methanol solution, and alkaline hydrolyze it at 100°C for 3 hours. The alkaline hydrolysis product is distilled at 150°C through a distillation column with a reflux ratio of 4:1. The target product fraction is collected and filtered through a modified microfiltration membrane with a pore size of 0.3μm to obtain pure perfluoroamine.

[0030] Wherein, the preparation method of modified microfiltration membrane: The microfiltration membrane loaded with ionic liquid is placed in a plasma device and subjected to plasma modification treatment using a mixed gas of allyl(diethylamino)dimethylsilane vapor and ammonia in a volume ratio of 0.02:1; the power range is set to 100 W, the frequency is controlled between 10 MHz, the gas flow rate is maintained at 20 ml / min, and the discharge time is continued for 200 seconds, thereby obtaining a microfiltration membrane loaded with ionic liquid with silane groups.

[0031] The preparation method of the microfiltration membrane loaded with ionic liquid is as follows: 0.05 g 1-allyl-3-butyl imidazole tetrafluoroborate (CAS No.: 863498-32-2), 200 g dimethylformamide (DMF), 0.03 g 2-(trifluoromethyl)pyrimidine-4,5-diamine (CAS No.: 1023817-05-1), 20 g polyvinylidene fluoride (PVDF) and 2 g triethylamine were mixed and stirred at 60 ° C for 100 minutes to ensure sufficient reaction; then filtered and the product was allowed to dry naturally; the final product was a microfiltration membrane loaded with ionic liquid.

[0032] Embodiment 2: Mix 2g of butyryl fluoride with 8g of dimethylamine, add 6g of anhydrous hydrogen fluoride and mix well. The electrofluorination reaction was carried out at a voltage of 40V, a current density of 20 A / m², and a temperature of -5°C for 5 hours. After the reaction was completed, it was washed with deionized water 4 times the total amount of the reaction solution, and then washed 4 times with a 15% mass concentration of sodium bicarbonate solution, each time with an amount of 18% of the volume of the mixed solution. After standing for 25 minutes, the organic phase was transferred to an alkaline hydrolysis kettle containing 40wt% potassium hydroxide methanol solution and alkaline hydrolyzed at 120°C for 4 hours. The product was distilled at 180°C through a distillation column with a reflux ratio of 3:1, and finally filtered through a modified microfiltration membrane with a pore size of 0.25μm to obtain perfluoroamine.

[0033] Wherein, the preparation method of modified microfiltration membrane: The microfiltration membrane loaded with ionic liquid is placed in a plasma device and subjected to plasma modification treatment using a mixed gas of allyl(diethylamino)dimethylsilane vapor and ammonia in a volume ratio of 0.02:1; the power range is set to 100 W, the frequency is controlled between 10 MHz, the gas flow rate is maintained at 20 ml / min, and the discharge time is continued for 200 seconds, thereby obtaining a microfiltration membrane loaded with ionic liquid with silane groups.

[0034] The preparation method of the microfiltration membrane loaded with ionic liquid is as follows: 0.05 g 1-allyl-3-butyl imidazole tetrafluoroborate (CAS No.: 863498-32-2), 200 g dimethylformamide (DMF), 0.03 g 2-(trifluoromethyl)pyrimidine-4,5-diamine (CAS No.: 1023817-05-1), 20 g polyvinylidene fluoride (PVDF) and 2 g triethylamine were mixed and stirred at 60 ° C for 100 minutes to ensure sufficient reaction; then filtered and the product was allowed to dry naturally; the final product was a microfiltration membrane loaded with ionic liquid.

[0035] Embodiment 3: Mix 3g of N-methylmorpholine with 6g of tripropylamine, add 10g of anhydrous hydrogen fluoride and stir thoroughly. The electrofluorination reaction was carried out at a voltage of 30V, a current density of 10 A / m² and a temperature of 15°C for 6 hours. After the reaction, the reaction solution was washed with deionized water 5 times the total amount of the reaction solution, and then washed 5 times with a 12% mass concentration of sodium hydroxide solution, each time with an amount of 25% of the volume of the mixed solution. After standing for 40 minutes, the organic phase was separated and transferred to an alkaline hydrolysis kettle containing 25wt% sodium hydroxide methanol solution, and alkaline hydrolysis was carried out at 80°C for 5 hours. The product was distilled at 200°C by a distillation column with a reflux ratio of 5:1, and finally filtered through a modified microfiltration membrane with a pore size of 0.4μm to obtain perfluoroamine.

[0036] Wherein, the preparation method of modified microfiltration membrane: The microfiltration membrane loaded with ionic liquid is placed in a plasma device and subjected to plasma modification treatment using a mixed gas of allyl(diethylamino)dimethylsilane vapor and ammonia in a volume ratio of 0.1:1.5; the power range is set to 150 W, the frequency is controlled between 15 MHz, the gas flow rate is maintained at 30 ml / min, and the discharge time is continued for 250 seconds, thereby obtaining a microfiltration membrane loaded with ionic liquid with silane groups.

[0037] The preparation method of the microfiltration membrane loaded with ionic liquid is as follows: 0.3 g 1-allyl-3-butyl imidazole tetrafluoroborate (CAS No.: 863498-32-2), 250 g dimethylformamide (DMF), 0.28 g 2-(trifluoromethyl)pyrimidine-4,5-diamine (CAS No.: 1023817-05-1), 30 g polyvinylidene fluoride (PVDF) and 3.5 g triethylamine were mixed and stirred at 65 ° C for 125 minutes to ensure sufficient reaction; then filtered and the product was allowed to dry naturally; the final product was a microfiltration membrane loaded with ionic liquid.

[0038] Embodiment 4: Mix 1.5g of triethylamine with 9g of methylamine, add 7g of anhydrous hydrogen fluoride and mix well. The electrofluorination reaction was carried out at a voltage of 45V, a current density of 25 A / m² and a temperature of 0°C for 3 hours. After the reaction, wash with deionized water twice the total amount of the reaction solution, and then wash with 18% mass concentration of sodium hydroxide solution 3 times, each time using 22% of the volume of the mixed solution. After standing for 20 minutes, the organic phase was transferred to an alkaline hydrolysis kettle containing 45wt% potassium hydroxide methanol solution and alkaline hydrolyzed at 110°C for 2 hours. The product was distilled at 120°C through a distillation column with a reflux ratio of 3.5:1, and finally filtered through a modified microfiltration membrane with a pore size of 0.45μm to obtain perfluoroamine.

[0039] Wherein, the preparation method of modified microfiltration membrane: The microfiltration membrane loaded with ionic liquid is placed in a plasma device and subjected to plasma modification treatment using a mixed gas of allyl(diethylamino)dimethylsilane vapor and ammonia in a volume ratio of 0.1:1.5; the power range is set to 150 W, the frequency is controlled between 15 MHz, the gas flow rate is maintained at 30 ml / min, and the discharge time is continued for 250 seconds, thereby obtaining a microfiltration membrane loaded with ionic liquid with silane groups.

[0040] The preparation method of the microfiltration membrane loaded with ionic liquid is as follows: 0.3 g 1-allyl-3-butyl imidazole tetrafluoroborate (CAS No.: 863498-32-2), 250 g dimethylformamide (DMF), 0.28 g 2-(trifluoromethyl)pyrimidine-4,5-diamine (CAS No.: 1023817-05-1), 30 g polyvinylidene fluoride (PVDF) and 3.5 g triethylamine were mixed and stirred at 65 ° C for 125 minutes to ensure sufficient reaction; then filtered and the product was allowed to dry naturally; the final product was a microfiltration membrane loaded with ionic liquid.

[0041] Embodiment 5: Mix 2.5g of butyryl fluoride with 7.5g of triamylamine, add 9g of anhydrous hydrogen fluoride and stir thoroughly. The electrofluorination reaction was carried out at a voltage of 38V, a current density of 18 A / m² and a temperature of 5°C for 4.5 hours. After the reaction was completed, the reaction solution was washed with deionized water 3.5 times the total amount of the reaction solution, and then washed 4 times with a 14% mass concentration of sodium bicarbonate solution, each time with an amount of 20% of the volume of the mixed solution. After standing for 35 minutes, the organic phase was separated and transferred to an alkaline hydrolysis kettle containing 30wt% sodium hydroxide methanol solution, and alkaline hydrolysis was carried out at 90°C for 3.5 hours. The product was distilled at 160°C through a distillation column with a reflux ratio of 4.5:1, and finally filtered through a modified microfiltration membrane with a pore size of 0.35μm to obtain perfluoroamine.

[0042] Wherein, the preparation method of modified microfiltration membrane: The microfiltration membrane loaded with ionic liquid was placed in a plasma device and subjected to plasma modification treatment using a mixed gas of allyl(diethylamino)dimethylsilane vapor and ammonia in a volume ratio of 0.2:2; the power range was set to 200 W, the frequency was controlled between 20 MHz, the gas flow rate was maintained at 40 ml / min, and the discharge time was continued for 300 seconds, thereby obtaining a microfiltration membrane loaded with ionic liquid with silane groups.

[0043] The preparation method of the microfiltration membrane loaded with ionic liquid is as follows: 0.5 g 1-allyl-3-butyl imidazole tetrafluoroborate (CAS No.: 863498-32-2), 3300 g dimethylformamide (DMF), 0.3 g 2-(trifluoromethyl)pyrimidine-4,5-diamine (CAS No.: 1023817-05-1), 40 g polytetrafluoroethylene (PTFE) and 5 g triethylamine were mixed and stirred at 70°C for 150 minutes to ensure sufficient reaction; then filtered and the product was allowed to dry naturally; the final product was a microfiltration membrane loaded with ionic liquid.

[0044] Embodiment 6: Mix 3g of N-methylmorpholine with 12g of ethylamine, add 6.5g of anhydrous hydrogen fluoride and mix well. The electrofluorination reaction was carried out under the conditions of voltage 32V, current density 12 A / m², and temperature -3℃ for 5.5 hours. After the reaction, it was washed with deionized water 4.5 times the total amount of the reaction solution, and then washed 5 times with a 17% mass concentration of sodium hydroxide solution, each time with an amount of 23% of the volume of the mixed solution. After standing for 38 minutes, the organic phase was transferred to an alkaline hydrolysis kettle containing 22wt% sodium hydroxide methanol solution and alkaline hydrolyzed at 105℃ for 4.5 hours. The product was distilled at 130℃ through a distillation column with a reflux ratio of 4:1, and finally filtered through a modified microfiltration membrane with a pore size of 0.2μm to obtain perfluoroamine.

[0045] Wherein, the preparation method of modified microfiltration membrane: The microfiltration membrane loaded with ionic liquid was placed in a plasma device and subjected to plasma modification treatment using a mixed gas of allyl(diethylamino)dimethylsilane vapor and ammonia in a volume ratio of 0.2:2; the power range was set to 200 W, the frequency was controlled between 20 MHz, the gas flow rate was maintained at 40 ml / min, and the discharge time was continued for 300 seconds, thereby obtaining a microfiltration membrane loaded with ionic liquid with silane groups.

[0046] The preparation method of the microfiltration membrane loaded with ionic liquid is as follows: 0.5 g 1-allyl-3-butyl imidazole tetrafluoroborate (CAS No.: 863498-32-2), 3300 g dimethylformamide (DMF), 0.3 g 2-(trifluoromethyl)pyrimidine-4,5-diamine (CAS No.: 1023817-05-1), 40 g polytetrafluoroethylene (PTFE) and 5 g triethylamine were mixed and stirred at 70°C for 150 minutes to ensure sufficient reaction; then filtered and the product was allowed to dry naturally; the final product was a microfiltration membrane loaded with ionic liquid.

[0047] Comparative Example 1 In this example, the microfiltration membrane is not modified, and polyvinylidene fluoride (PVDF) is directly used as the microfiltration membrane. The rest is completely consistent with Example 1.

[0048] Comparative Example 2 In the process of microfiltration membrane modification in this example, 1-allyl-3-butyl imidazole tetrafluoroborate was not added, and the rest was completely consistent with Example 1.

[0049] Comparative Example 3 In the process of microfiltration membrane modification in this example, 2-(trifluoromethyl)pyrimidine-4,5-diamine was not added, and the rest was completely consistent with Example 1.

[0050] Test method: 1. Product yield Record the mass of the target product and calculate its percentage relative to the theoretical amount produced in the raw material, which is the product yield: yield % = (actual weight of target product / actual weight of theoretical product) × 100%.

[0051] 2. Purity testing The products were separated by gas chromatography, and the ratio of the peak area of ​​the target compound to the total peak area was detected by mass spectrometry to determine the purity of the product.

[0052] Test results:

[0053] The test results of the above embodiments and comparative examples show that the optimized process of the present method significantly improves the yield and purity of perfluoroamine, which fully verifies the superiority of the present invention.

[0054] Although the present invention has been described in detail above by means of general description, specific implementation methods and tests, it is obvious to those skilled in the art that some modifications or improvements may be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A method for preparing a high-yield perfluoroamine, characterized in that: The steps include: Step 1: Raw material mixing and electrofluorination reaction: 1-3 parts by weight of a low-boiling-point carbon compound and 6-12 parts by weight of a high-boiling-point amine compound are mixed and added to an electrolytic cell, and 6-10 parts by weight of anhydrous hydrogen fluoride are added and fully mixed with the mixture; an electrofluorination reaction is started under set conditions, and the reaction lasts for 3-6 hours to generate a mixed reaction liquid; Step 2: Post-treatment washing: The mixed reaction liquid is washed several times with deionized water at a volume of 2-5 times the total volume of the reaction liquid to remove water-soluble impurities, and then the reaction liquid is washed with alkaline solution for 3-5 times, each time with an amount of 15%-25% of the volume of the mixed liquid, to remove residual hydrogen fluoride, and the washed mixed liquid is allowed to stand for 20-40 minutes to allow it to naturally separate into layers; Step 3: Purification: The organic phase rich in the target product after separation in step 2 is transferred to an alkaline hydrolysis kettle, and alkaline hydrolysis is performed at a set temperature for 2-5 hours. The product after alkaline hydrolysis is introduced into a distillation column, and distilled at 100-200° C., and the target product fraction is collected. The distillation product is filtered through a modified microfiltration membrane with a pore size of 0.2-0.45 μm to obtain a pure perfluoroamine compound; The modified microfiltration membrane is a loaded ionic liquid microfiltration membrane with a silane group; an amine group is introduced into the microfiltration membrane, and then the modified microfiltration membrane is subjected to an amine-allyl addition reaction with 1-allyl-3-butyl imidazole tetrafluoroborate and allyl (diethylamino) dimethylsilane under ammonia catalysis to obtain the modified microfiltration membrane.

2. The method for preparing a high-yield perfluoroamine according to claim 1, characterized in that: The low boiling point carbon compound is any one or more of triethylamine, butyryl fluoride and N-methylmorpholine.

3. The method for preparing a high-yield perfluoroamine according to claim 1, characterized in that: The high boiling point amine compound is selected from one or a combination of methylamine, ethylamine, dimethylamine, tripropylamine, tributylamine and tripentylamine.

4. The method for preparing a high-yield perfluoroamine according to claim 1, characterized in that: The electrofluorination reaction conditions are: voltage of 30-45V, current density of 10-25 A / m², and temperature of -5 to 15°C.

5. The method for preparing a high-yield perfluoroamine according to claim 1, characterized in that: The alkali solution is selected from at least one of sodium bicarbonate and sodium hydroxide, and the mass concentration is 10-20%.

6. The method for preparing a high-yield perfluoroamine according to claim 1, characterized in that: The alkaline hydrolysis agent in the alkaline hydrolysis kettle is a methanol solution of sodium hydroxide or potassium hydroxide, and the concentration of the alkaline hydrolysis agent is 20-45wt%.

7. The method for preparing a high-yield perfluoroamine according to claim 1, characterized in that: The alkaline hydrolysis temperature is 80-120°C.

8. The method for preparing a high-yield perfluoroamine according to claim 1, characterized in that: The reflux ratio of the distillation column is in the range of 3-5:

1.

9. The method for preparing a high-yield perfluoroamine according to claim 1, characterized in that: The modified microfiltration membrane is a silane-based loaded ionic liquid microfiltration membrane, and its preparation method comprises the following steps: The loaded ionic liquid microfiltration membrane is placed in a plasma device, and a mixed gas of allyl (diethylamino) dimethylsilane vapor and ammonia in a volume ratio of 0.02-0.2:1-2 is used for plasma modification treatment; the power range is set to 100-200W, the frequency is controlled between 10-20MHz, the gas flow rate is maintained at 20-40ml / min, and the discharge time is continued for 200-300 seconds, thereby obtaining a loaded ionic liquid microfiltration membrane with silane groups.

10. The method for preparing a high-yield perfluoroamine according to claim 9, characterized in that: The preparation method of the loaded ionic liquid microfiltration membrane is as follows: Weigh the raw materials according to specific proportions, as follows: 1-allyl-3-butyl imidazole tetrafluoroborate, measured in 0.05 to 0.5 parts; Dimethylformamide is used as a solvent, measured at 200 to 300 parts; 2-(Trifluoromethyl)pyrimidine-4,5-diamine, measured in 0.03 to 0.3 parts; Microfiltration membrane, 20 to 40 parts, selected from at least one of polyvinylidene fluoride or polytetrafluoroethylene; Triethylamine, used as a catalyst, measured in 2 to 5 parts; After all components are mixed, stir at 60 to 70°C for 100 to 150 minutes to fully react; Then, the product is filtered and allowed to dry naturally; finally, an ionic liquid-loaded microfiltration membrane is obtained.

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