Fluorine-containing polyimide composite antifouling anticorrosive wear-resistant powder coating and preparation and application method thereof

Abstract

The application discloses a fluorine-containing polyimide composite antifouling anticorrosive wear-resistant powder coating and a preparation and application method thereof. The powder coating comprises, in mass fractions, 49-60% of fluorine-containing polyimide resin, 30-50% of polyphenylene sulfide resin, 0-15% of quaternary ammonium salt side group polyimide resin, 0-15% of perfluoro long-chain side group polyimide resin and 0-1% of antifouling filler, and the particle size of the antifouling filler is 5-150 nm. Furthermore, the application also provides a preparation and application method of the powder coating, and the powder coating has the advantages of simple configuration, convenient preparation, simple components and environmental friendliness.

Description

Technical Field

[0001] This invention relates to the field of powder coating preparation technology, and in particular to a fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating and its preparation and application methods. Background Technology

[0002] The development of the marine economy is inseparable from the support of ships and other marine facilities. Marine corrosion and fouling prevention have always been primary concerns for marine industries such as fisheries, marine transportation, and offshore equipment. Antifouling and anticorrosion coatings applied to marine infrastructure can provide long-term corrosion protection. These coatings react rapidly with iron atoms on the steel surface, generating a dual physical and chemical protective effect, and can withstand chloride ion corrosion for extended periods. Current marine coatings generally use epoxy resin as the film-forming matrix. However, the poor heat resistance and hydrophobicity of epoxy resin make it difficult for existing marine coatings to meet the requirements of some extremely humid, high-temperature, and high-salt-spray marine environments. In the process of developing marine resources, biofouling severely restricts the development of the marine economy, and the annual losses to ships, marine ranches, and marine facilities caused by biofouling are incalculable. In the 1970s, organotin self-polishing antifouling coatings were developed. Due to their broad-spectrum and effective bactericidal properties, they quickly became the mainstream antifouling coating product. However, they also caused enormous harm to the marine ecosystem. Organotin compounds accumulate in high concentrations in marine organisms, are difficult to decompose, and persist in the environment for a long time, causing deformities in organisms. More seriously, these polluted marine organisms can endanger human health through the food chain, and therefore their use has been largely banned. In conclusion, to meet market demands and meet the requirements for developing pollution-free marine anti-corrosion and antifouling technologies, the development of a multifunctional, environmentally friendly coating that integrates antifouling, anti-corrosion, low pollution, and low cost is urgently needed. Summary of the Invention

[0003] This invention provides a fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating and its preparation and application methods, in order to overcome the shortcomings of the prior art. It prepares a powder coating that is convenient to spray and use. Moreover, the powder coating is an environmentally friendly coating formulation that is simple to prepare, easy to use, has simple composition, and does not contain organotin.

[0004] In order to achieve the objectives of this invention, the following technologies are proposed: Firstly, a fluorinated polyimide composite antifouling, anticorrosion, and wear-resistant powder coating is proposed, comprising, by weight parts: The fluorinated polyimide resin contains 49% to 60% fluorinated polyimide resin, and the particle size of the fluorinated polyimide resin is 200 mesh to 400 mesh.

[0005] Polyphenylene sulfide resin (PPS) comprises 30% to 50% of the material, with a particle size of 200 to 400 mesh. As a film-forming aid, PPS is one of the most stable resins among thermoplastic polymers. It is beneficial for improving coalescence properties, promoting polymer plastic flow and elastic deformation, and has excellent insulation, temperature resistance, hardness, chemical corrosion resistance, and wear resistance.

[0006] The quaternary ammonium salt side-chain polyimide resin is 0 to 15%, and the particle size of the quaternary ammonium salt side-chain polyimide resin is 200 mesh to 400 mesh.

[0007] The perfluorinated long-chain side-chain polyimide resin comprises 0 to 15% of the total content, and the particle size of the perfluorinated long-chain side-chain polyimide resin is 200 to 400 mesh.

[0008] Antifouling filler content is 0% to 1%, and the particle size of the antifouling filler is 5nm to 150nm.

[0009] Furthermore, the structural formula of the fluorinated polyimide resin is: Where n is between 20 and 70.

[0010] Fluorinated polyimide resin serves as the film-forming matrix, containing a high content of fluorine atoms, which increases the hydrophobicity of the coating, giving it excellent self-cleaning properties and good corrosion resistance. This effectively prevents water, oil, and other impurities from adhering to the equipment surface and causing slow corrosion during operation and maintenance. The functional groups ether bonds and hydroxyl groups it contains can increase the adhesion of the coating, making it a resin with strong adhesion, which is beneficial for increasing the hardness of the coating film.

[0011] Furthermore, the structural formula of the quaternary ammonium salt side-group polyimide resin is as follows: .

[0012] The structure of quaternary ammonium salt side-chain polyimide resin contains phosphocholine groups with bactericidal capabilities. These groups are phosphorus-containing quaternary ammonium salts with excellent antibacterial properties, which helps improve the antibacterial performance of the coating, making it a highly efficient barrier polymer. Therefore, it indirectly repels marine organisms without polluting the marine environment.

[0013] Furthermore, the structural formula of the perfluorinated long-chain side-group polyimide resin is as follows: .

[0014] Perfluorinated long-chain side-chain polyimide resins possess an extremely high fluorine content, thus enhancing the overall corrosion resistance of the coating. Fluorine is the most electronegative element in the periodic table (approximately 4.0), meaning it has a strong ability to attract electrons. This high electronegativity allows fluorine atoms to form very stable compounds with many other elements, which typically exhibit high chemical stability. The chemical bonds formed by fluorine atoms with other elements (such as the CF bond) have high bond energies. For example, the CF bond energy is approximately 485 kJ / mol, much higher than the CH bond (approximately 413 kJ / mol) and the C-Cl bond (approximately 375 kJ / mol). This high bond energy makes fluorine compounds more stable and less prone to degradation under high temperature, high pressure, and corrosive environments. The small size and high charge density of fluorine atoms result in low polarizability, meaning it is not easily polarized or deformed. This low polarizability prevents the molecular structure of fluorine compounds from being twisted or broken when attacked by external chemicals, thereby improving their corrosion resistance. The chemical structure formed by fluorine atoms and other atoms can create a dense, inert surface layer that effectively blocks external chemicals and moisture. This inert surface layer prevents corrosive media (such as acids, alkalis, and salts) from directly contacting the material surface, thus protecting the material from corrosion. Furthermore, the introduction of fluorine atoms enhances the resin's hydrophobic and oleophobic properties. Based on this, it can be immersed in seawater for extended periods without corrosion and its waterproof performance is improved.

[0015] Furthermore, the antifouling filler is one or more of nano cuprous oxide, nano zinc oxide, cuprous thiocyanate, zinc pyridinethione, alloy powder, and copper pyridinethione, specifically the Korean AFP10 alloy powder.

[0016] Secondly, a method for preparing a fluorinated polyimide composite antifouling, anticorrosion, and wear-resistant powder coating is proposed. The method includes the following steps: Step 1: Weigh 49% to 60% of the prepared fluorinated polyimide resin, weigh 30% to 50% of the polyphenylene sulfide resin, weigh 0% to 15% of the prepared quaternary ammonium salt side-chain polyimide resin, weigh 0% to 15% of the prepared perfluorinated long-chain side-chain polyimide resin, and weigh 0% to 1% of the antifouling filler. Step 2: The fluorinated polyimide resin (49% to 60%), polyphenylene sulfide resin (30% to 50%), quaternary ammonium salt side-chain polyimide resin (0 to 15%), perfluorinated long-chain side-chain polyimide resin (0 to 15%), and antifouling filler (0 to 1%) weighed in Step 1 are mixed using a high-speed mixer to obtain a fluorinated polyimide composite antifouling, anticorrosion, and wear-resistant powder coating. The high-speed mixer mentioned above is an ultra-high-speed airflow mixing mill, which pulverizes and thoroughly mixes the components.

[0017] Furthermore, the fluorinated polyimide resin is prepared through the following steps: Step 10: Add diphenyl ether tetracarboxylic dianhydride, hexafluorodiamine and dimethylformamide to the reaction vessel in a molar ratio of 1:1:10 to 25; Step 11: Stir the mixture in a nitrogen or argon atmosphere at a temperature of 10°C to 15°C for 18 to 24 hours. Then pour the resulting reaction solution into ethanol, collect the precipitate, dry it to obtain polyamic acid powder, and finally heat imidize it at 200°C to 230°C for 8 to 12 hours to obtain fluorinated polyimide resin.

[0018] Furthermore, the quaternary ammonium salt side-group polyimide resin is prepared by the following steps: Step 100: Under the protection of nitrogen or argon, an aromatic diamine containing phosphorus and quaternary ammonium salt groups is dissolved in m-cresol, with the solid content controlled at 5% to 10%. Diphenyl ether tetracarboxylic dianhydride and catalyst isoquinoline or benzoic acid are added at 0°C to 25°C and reacted for 1 to 4 hours. Then, the reaction is carried out at 80°C to 100°C for 1 to 4 hours, and finally at 180°C to 200°C for 18 to 24 hours. Step 101: Dissolve the obtained reaction product in methanol and collect the precipitate; Step 102: Wash with methanol and dry to obtain quaternary ammonium salt side-chain polyimide resin.

[0019] Furthermore, the perfluorinated long-chain side-group polyimide resin is prepared by the following steps: Step 1000: Under the protection of nitrogen or argon, an aromatic diamine containing a perfluorinated long-chain group is dissolved in m-cresol, with the solid content controlled at 5% to 10%. Diphenyl ether tetracarboxylic dianhydride and the catalyst isoquinoline or benzoic acid are added at 0°C to 25°C and reacted for 1 to 4 hours. Then, the reaction is carried out at 80°C to 100°C for 1 to 4 hours, and finally at 180°C to 200°C for 18 to 24 hours. Step 1001: Dissolve the obtained reaction product in methanol and collect the precipitate; Step 1002: Wash with methanol and dry to obtain perfluorinated long-chain side-chain polyimide resin.

[0020] Thirdly, a method for applying fluorinated polyimide composite antifouling, anticorrosion, and wear-resistant powder coating is proposed, including the following steps: Step a: The surface of the metal substrate is pretreated by degreasing through methods such as sandblasting and polishing.

[0021] The metal substrate is one or more of stainless steel, aluminum alloy, carbon steel, copper alloy, and titanium alloy. Step b: Wash the surface of the metal substrate with water; Step c: Bake the metal substrate in an oven at 340°C to 350°C for 30 to 40 minutes; Step d involves applying a fluorinated polyimide composite antifouling, anticorrosion, and wear-resistant powder coating to the metal substrate obtained in step c using an electrostatic spray gun.

[0022] The electrostatic spray gun is set with compressed air pressure of 0.5 MPa to 0.7 MPa, electrostatic spraying voltage of 60 kV to 90 kV, current of 10 μA to 20 μA, and spraying distance of 15 cm to 30 cm. Step e: Place the sprayed metal substrate in a curing chamber and cure it at 330°C to 340°C for 10 to 25 minutes. Then, the metal substrate can be quenched.

[0023] The advantages of the above technical solution are: The fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating provided by this invention has a simple composition and the components work synergistically to greatly improve the antifouling, anticorrosion and wear-resistant properties of the coating prepared by this coating, and can provide wear-resistant and anticorrosion protection for the substrate.

[0024] Specifically, due to the high fluorine content in the polyimide resin, the surface water contact angle of the composite coating formed by this paint can reach 86-110°. Fluorine-containing resins have low surface energy, which can reduce the adhesion of microorganisms, have good chemical stability, and have a certain degree of anti-corrosion effect in seawater. From the material itself, the hydrophobicity of the coating is increased by modifying the polyimide, which gives it good self-cleaning properties. The asymmetric molecular structure and the large trifluoromethyl-substituted structure will reduce the dielectric constant of the material, which can realize a new type of material that combines wear resistance and low dielectric constant. This makes the antifouling and anti-corrosion coating effectively prevent corrosion from external substances and provide good protection for equipment.

[0025] Specifically, the addition of quaternary ammonium salt side-chain polyimide resin and perfluorinated long-chain side-chain polyimide resin is used to inhibit the attachment of marine organisms without causing fatal harm to marine life or affecting the local marine ecosystem. This reduces the drawbacks of humans poisoning marine life by using self-polishing organotin and other toxic heavy metals for a long time.

[0026] In summary, the preparation method provided by this invention can obtain powder coatings with excellent properties, high mechanical strength, strong adhesion, high coating adhesion, impact resistance, high temperature oxidation resistance, high stability, and good wear resistance. Furthermore, the use of this powder coating can improve the anti-corrosion protection effect of ships. Detailed Implementation

[0027] Example 1 A fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating comprises, by weight percentage: 49% fluorinated polyimide resin, 30% polyphenylene sulfide resin, 10% quaternary ammonium salt side-chain polyimide resin, 10% perfluorinated long-chain side-chain polyimide resin, 0.5% nano-sized zinc oxide and 0.5% cuprous thiocyanate.

[0028] The structural formula of the above-mentioned fluorinated polyimide resin is: Where n is between 20 and 70.

[0029] The structural formula of the quaternary ammonium salt side-group polyimide resin is: .

[0030] The structural formula of perfluorinated long-chain side-group polyimide resin is: .

[0031] The fluorinated polyimide resin was prepared by the following method: diphenyl ether tetracarboxylic dianhydride (1 mol, 310 g), hexafluorodiamine (1 mol, 366 g) and dimethylformamide (20 mol, 1460 g) were added to a reaction vessel and stirred uniformly at 500 r / min for 18 hours at 15°C under nitrogen atmosphere. The reaction product was then poured into a mixture of ethanol and water, and the precipitate was collected by filtration. The precipitate was dried under vacuum at 80°C to obtain polyamic acid powder. Finally, the fluorinated polyimide resin was obtained by thermal imidization at 230°C for 8 hours.

[0032] The quaternary ammonium salt side-chain polyimide resin was prepared by the following method: Under nitrogen protection, 0.1 mol (69.6 g) of an aromatic diamine containing phosphorus and quaternary ammonium salt groups and m-cresol (8.4 mol (907.2 g) were added to a reaction vessel and dissolved. Diphenyl ether tetracarboxylic dianhydride (0.1 mol (31.0 g) and isoquinoline catalyst (0.004 mol (0.5 g)) were added at 15 °C and reacted for 2 hours. Then, the reaction was carried out at 80 °C for 4 hours and finally at 200 °C for 18 hours. The resulting reaction product was dissolved in methanol, and the precipitate was collected, washed with methanol, and dried to obtain the quaternary ammonium salt side-chain polyimide resin.

[0033] The perfluorinated long-chain side-group polyimide resin was prepared by the following method: Under nitrogen protection, aromatic diamine containing perfluorinated long-chain groups (0.1 mol, 58.3 g) and m-cresol (7.4 mol, 803.7 g) were added to a reaction vessel and dissolved. Diphenyl ether tetracarboxylic dianhydride (0.1 mol, 31.0 g) and benzoic acid catalyst (0.004 mol, 0.5 g) were added at 15 °C and reacted for 2 hours. Then, the reaction was carried out at 80 °C for 4 hours and finally at 200 °C for 18 hours. The resulting reaction product was dissolved in methanol, and the precipitate was collected, washed with methanol, and dried to obtain the perfluorinated long-chain side-group polyimide resin.

[0034] This embodiment provides a method for preparing fluorinated polyimide composite antifouling, anticorrosion, and wear-resistant powder coatings, specifically including the following steps: Weigh the raw materials according to the specified ratio, and use a high-speed mixer to blend and pulverize the raw materials under ultra-high-speed airflow to obtain a fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating.

[0035] Preferably, the particle size of the fluorinated polyimide resin, polyphenylene sulfide resin, quaternary ammonium salt side-chain polyimide resin, and perfluorinated long-chain side-chain polyimide resin is 200 mesh to 400 mesh; the particle size of the antifouling filler is 400 mesh to 600 mesh, and the particle size of the nano-level antifouling filler is 5 nm to 150 nm.

[0036] This embodiment also provides a method for using the above-mentioned fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating, specifically including the following steps: Step 1: Pre-treat the metal substrate with detergent and sandblasting machine, then wash with clean water, and finally bake in an oven at 350℃ for 30 minutes before use.

[0037] Step 2: Use an electrostatic spray gun to fully spray the fluorinated polyimide composite anti-fouling, anti-corrosion and wear-resistant powder coating onto the pretreated metal workpiece in Step 1. After spraying for 2 minutes, transfer it to the curing chamber and cure it at 340℃ for 10 minutes. Then take out the metal workpiece and quench it.

[0038] Example 2 A fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating comprises, by weight percentage, 49% fluorinated polyimide resin, 30% polyphenylene sulfide resin, 10% quaternary ammonium salt side-chain polyimide resin, 10% perfluorinated long-chain side-chain polyimide resin, 0.5% nano-sized cuprous oxide and 0.5% zinc pyridinethione.

[0039] The preparation and application methods of the fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating and its components involved in this embodiment are the same as those proposed in Example 1, so they will not be described again in this embodiment.

[0040] Example 3 A fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating comprises, by weight percentage, 49% fluorinated polyimide resin, 30% polyphenylene sulfide resin, 10% quaternary ammonium salt side-chain polyimide resin, 10% perfluorinated long-chain side-chain polyimide resin and 1% nano-sized cuprous oxide.

[0041] The preparation and application methods of the fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating and its components involved in this embodiment are the same as those proposed in Example 1, so they will not be described again in this embodiment.

[0042] Example 4 A fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating comprises, by weight percentage, 49% fluorinated polyimide resin, 35% polyphenylene sulfide resin, 15% quaternary ammonium salt side-group polyimide resin and 1% nano-sized zinc oxide.

[0043] The preparation and application methods of the fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating and its components involved in this embodiment are the same as those proposed in Example 1, so they will not be described again in this embodiment.

[0044] Example 5 A fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating comprises, by weight percentage, 49% fluorinated polyimide resin, 30.5% polyphenylene sulfide resin, 10% quaternary ammonium salt side-chain polyimide resin, 10% perfluorinated long-chain side-chain polyimide resin, and 0.5% Korean AFP10 alloy powder.

[0045] The preparation and application methods of the fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating and its components involved in this embodiment are the same as those proposed in Example 1, so they will not be described again in this embodiment.

[0046] Example 6 A fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating comprises, by weight percentage, 49% fluorinated polyimide resin, 35.5% polyphenylene sulfide resin, 15% quaternary ammonium salt side-chain polyimide resin and 0.5% copper pyridinethione.

[0047] The preparation and application methods of the fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating and its components involved in this embodiment are the same as those proposed in Example 1, so they will not be described again in this embodiment.

[0048] Example 7 A fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating comprises, by weight percentage, 60% fluorinated polyimide resin, 30% polyphenylene sulfide resin, and 10% quaternary ammonium salt side-chain polyimide resin.

[0049] The preparation and application methods of the fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating and its components involved in this embodiment are the same as those proposed in Example 1, so they will not be described again in this embodiment.

[0050] Comparative Example 1 A fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating comprises, by weight percentage, 49% fluorinated polyimide resin, 50% polyphenylene sulfide resin and 1% nano-sized cuprous oxide.

[0051] The preparation and application methods of the fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating and its components involved in this comparative example are the same as those proposed in Example 1, and therefore will not be repeated in this example.

[0052] Comparative Example 2 A fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating comprises, by weight percentage, 49% fluorinated polyimide resin, 35% polyphenylene sulfide resin, 15% perfluorinated long-chain side-group polyimide resin and 1% nano-sized cuprous oxide.

[0053] The preparation and application methods of the fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating and its components involved in this comparative example are the same as those proposed in Example 1, and therefore will not be repeated in this example.

[0054] Comparative Example 3 A fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating comprises, by weight percentage, 60% fluorinated polyimide resin and 40% polyphenylene sulfide resin.

[0055] The preparation and application methods of the fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating and its components involved in this comparative example are the same as those proposed in Example 1, and therefore will not be repeated in this example.

[0056] To investigate the fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coatings prepared in each embodiment and comparative example, tests were conducted on properties such as hardness, impact resistance, adhesion, biological resistance and salt spray resistance. The test standards and results are shown in Table 1.

[0057] Table 1. Comparison of Test Standards and Test Results for Each Example and Comparative Example Based on the changes in composition and component content of the powder coatings in Examples 1 to 7 and Comparative Examples 1 to 3, and in conjunction with the test results of various properties in Table 1, it can be concluded that: (1) When nano-sized cuprous oxide and zinc pyridinethione are used as antifouling fillers, the adhesion of the powder coating is significantly improved compared with that of nano-sized zinc oxide and cuprous thiocyanate. The change of antifouling filler has little effect on the hardness, impact resistance, biocompatibility and salt spray resistance of the powder coating. And as can be seen from the table, the adhesion of the powder coating is the greatest when nano-sized cuprous oxide and zinc pyridinethione are used as antifouling fillers.

[0058] (2) The powder coatings prepared by Example 2 and Example 3, compared with Example 2, only nano-sized cuprous oxide is used as antifouling filler in Example 3. With this design, the adhesion of the powder coating prepared in Example 3 is significantly reduced.

[0059] (3) Compared with Example 1, Example 4 lacks the perfluorinated long-chain side group polyimide resin and cuprous thiocyanate. However, with the adjustment of the components, its various properties are not much different from those of Example 1.

[0060] (4) Compared with Example 3, Example 5 uses Korean AFP10 alloy powder as antifouling filler. After the replacement, it was found that the various properties of the powder coating changed little.

[0061] (5) In Example 6, compared with Example 4, copper pyridinethione was used as an antifouling filler. After the replacement, it was found that the adhesion and impact resistance of the coating were significantly affected, and both showed a downward trend.

[0062] (6) Compared with Examples 4 and 6, Example 7 did not use antifouling filler. With the absence of antifouling filler, its adhesion ability decreased compared with Example 4, but its adhesion ability and impact resistance were improved compared with Example 6.

[0063] (7) In Comparative Examples 1 to 3, the prepared powder coatings lacked the quaternary ammonium salt side-chain polyimide resin compared to Examples 1 to 7. The absence of the quaternary ammonium salt side-chain polyimide resin resulted in partial corrosion problems in the corresponding powder coatings' resistance to microbial corrosion. Therefore, it can be seen that the addition or absence of the quaternary ammonium salt side-chain polyimide resin has a significant impact on the anti-corrosion performance of the powder coating. Furthermore, in Comparative Example 3, without the use of antifouling fillers, the adhesion of the powder coating was improved because it contained no hard particles.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A fluorinated polyimide composite antifouling, anticorrosion, and wear-resistant powder coating, characterized in that, In terms of mass percentage, including: Fluorinated polyimide resin 49% to 60%; 30% to 50% polyphenylene sulfide resin; Quaternary ammonium salt side-chain polyimide resin 10% or 15%; 0 to 15% of perfluorinated long-chain side-group polyimide resin; Antifouling filler content: 0 to 1%; The sum of the mass percentages of each component is 100%.

2. The fluorinated polyimide composite antifouling, anticorrosion, and wear-resistant powder coating according to claim 1, characterized in that, The structural formula of fluorinated polyimide resin is: ， Where n is between 20 and 70.

3. The fluorinated polyimide composite antifouling, anticorrosion, and wear-resistant powder coating according to claim 1, characterized in that, The structural formula of the quaternary ammonium salt side-group polyimide resin is: 。 4. The fluorinated polyimide composite antifouling, anticorrosion, and wear-resistant powder coating according to claim 1, characterized in that, The structural formula of perfluorinated long-chain side-group polyimide resin is: 。 5. The fluorinated polyimide composite antifouling, anticorrosion, and wear-resistant powder coating according to claim 1, characterized in that, The antifouling filler is one or more of the following: nano cuprous oxide, nano zinc oxide, cuprous thiocyanate, zinc pyridinethione, alloy powder, and copper pyridinethione.

6. A method for preparing a fluorinated polyimide composite antifouling, anticorrosion, and wear-resistant powder coating, characterized in that, The preparation of the fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating according to any one of claims 1 to 5 includes the following steps: Step 1: Weigh 49% to 60% of the prepared fluorinated polyimide resin, weigh 30% to 50% of the polyphenylene sulfide resin, weigh 10% or 15% of the prepared quaternary ammonium salt side-chain polyimide resin, weigh 0 to 15% of the prepared perfluorinated long-chain side-chain polyimide resin, and weigh 0 to 1% of the antifouling filler. Step 2: Using a high-speed mixer, 49% to 60% of the fluorinated polyimide resin, 30% to 50% of the polyphenylene sulfide resin, 10% or 15% of the quaternary ammonium salt side-chain polyimide resin, 0 to 15% of the perfluorinated long-chain side-chain polyimide resin, and 0 to 1% of the antifouling filler weighed in Step 1 are mixed to obtain a fluorinated polyimide composite antifouling, anticorrosion, and wear-resistant powder coating.

7. The preparation method of the fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating according to claim 6, characterized in that, Fluorinated polyimide resin is prepared through the following steps: Step 10: Add diphenyl ether tetracarboxylic dianhydride, hexafluorodiamine and dimethylformamide to the reaction vessel in a molar ratio of 1:1:10 to 25; Step 11: Stir the mixture in a nitrogen or argon atmosphere at a temperature of 10°C to 15°C for 18 to 24 hours. Then pour the resulting reaction solution into ethanol, collect the precipitate, dry it to obtain polyamic acid powder, and finally heat imidize it at 200°C to 230°C for 8 to 12 hours to obtain fluorinated polyimide resin.

8. The method for preparing the fluorinated polyimide composite antifouling, anticorrosion, and wear-resistant powder coating according to claim 6, characterized in that, Quaternary ammonium salt side-group polyimide resins are prepared by the following steps: Step 100: Under the protection of nitrogen or argon, an aromatic diamine containing phosphorus and quaternary ammonium salt groups is dissolved in m-cresol, with the solid content controlled at 5% to 10%. Diphenyl ether tetracarboxylic dianhydride and catalyst isoquinoline or benzoic acid are added at 0°C to 25°C and reacted for 1 to 4 hours. Then, the reaction is carried out at 80°C to 100°C for 1 to 4 hours, and finally at 180°C to 200°C for 18 to 24 hours. Step 101: Dissolve the obtained reaction product in methanol and collect the precipitate; Step 102: Wash with methanol and dry to obtain quaternary ammonium salt side-chain polyimide resin.

9. The preparation method of the fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating according to claim 6, characterized in that, Perfluorinated long-chain side-chain polyimide resins are prepared by the following steps: Step 1000: Under the protection of nitrogen or argon, an aromatic diamine containing a perfluorinated long-chain group is dissolved in m-cresol, with the solid content controlled at 5% to 10%. Diphenyl ether tetracarboxylic dianhydride and the catalyst isoquinoline or benzoic acid are added at 0°C to 25°C and reacted for 1 to 4 hours. Then, the reaction is carried out at 80°C to 100°C for 1 to 4 hours, and finally at 180°C to 200°C for 18 to 24 hours. Step 1001: Dissolve the obtained reaction product in methanol and collect the precipitate; Step 1002: Wash with methanol and dry to obtain perfluorinated long-chain side-chain polyimide resin.

10. A method for applying a fluorinated polyimide composite antifouling, anticorrosion, and wear-resistant powder coating, characterized in that, The application of the fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating according to any one of claims 1 to 5 includes the following steps: Step a: Pre-treat the surface of the metal substrate; The metal substrate is one or more of stainless steel, aluminum alloy, carbon steel, copper alloy, and titanium alloy. Step b: Wash the surface of the metal substrate with water; Step c: Bake the metal substrate in an oven at 340°C to 350°C for 30 to 40 minutes; Step d: Apply fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating to the metal substrate obtained in step c using an electrostatic spray gun. Among them, the electrostatic spray gun is set with compressed air pressure of 0.5MPa to 0.7MPa, electrostatic spraying voltage of 60kV to 90kV, current of 10μA to 20μA, and spraying distance of 15cm to 30cm. Step e: Place the sprayed metal substrate in a curing chamber and cure it at 330°C to 340°C for 10 to 25 minutes.

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