Fluorine-containing polyimide composite antifouling, anticorrosive and wear-resistant powder coating as well as preparation and application methods thereof

Abstract

The invention relates to a fluorine-containing polyimide composite antifouling anticorrosion wear-resistant powder coating and preparation and application methods thereof, and the powder coating comprises the following components in percentage by mass: 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, the particle size of the antifouling filler is 5 nm to 150 nm. In addition, the invention further provides a preparation and application method of the powder coating, and the powder coating has the advantages of being simple in preparation, convenient to prepare, simple in component, environmentally friendly and the like.

Description

Technical Field

[0001] The invention relates to the technical field of powder coating preparation, and in particular to a fluorine-containing polyimide composite antifouling, anticorrosive, and wear-resistant powder coating and a preparation and application method thereof. Background Art

[0002] The development of the marine economy is inseparable from the support of "ships and boats" and other marine facilities, and marine anti-corrosion and anti-fouling have always been the primary issues that marine industries such as marine fisheries, marine transportation, and offshore work equipment consider all the time. Anti-fouling and anti-corrosion coatings applied to marine infrastructure can ensure a longer anti-corrosion period. They can react quickly with iron atoms on the surface of steel structures to generate materials with physical and chemical dual protection, and can withstand chloride ion corrosion for a long time. Marine coatings in the prior art generally use epoxy resin as a film-forming matrix. However, the heat resistance and hydrophobicity of epoxy resin are poor, making it difficult for marine ship coatings in the prior art to meet the use of some extremely humid, high temperature, and high salt fog marine environments. In the process of marine resource development, the problem of biological attachment and fouling in the ocean has seriously restricted the development of the marine resource economy, and the annual losses caused by marine biological attachment and fouling of ships, marine ranches, marine facilities, etc. are difficult to estimate. In the 1970s, organotin self-polishing antifouling coatings were developed. Due to its broad-spectrum and effective bactericidal effect, it quickly became the mainstream product of antifouling coatings. However, it also caused great harm to the marine ecological environment. Organotin compounds are highly concentrated in marine organisms, difficult to decompose and exist in the environment for a long time, which can cause deformation of organisms. What is more serious is that these contaminated marine organisms will endanger human health through the food chain, so they have been basically banned from use. In summary, in order to meet the needs of the market and develop pollution-free marine anticorrosion and antifouling technology, it is urgent to develop a multifunctional, antifouling, anticorrosive, low-pollution, low-cost and environmentally friendly coating. Summary of the invention

[0003] The present invention provides a fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating and a preparation and application method thereof, so as to solve the deficiencies of the above-mentioned prior art, prepare and conveniently use the powder coating by spraying, and the powder coating is simple in configuration, convenient in preparation, simple in ingredients, and is an environmentally friendly coating preparation free of organic tin.

[0004] In order to achieve the purpose of the present invention, the following technologies are proposed: First, a fluorinated polyimide composite antifouling, anticorrosive, and wear-resistant powder coating is proposed, which comprises, by weight: The fluorine-containing polyimide resin accounts for 49% to 60%, and the particle size of the fluorine-containing polyimide resin is 200 meshes to 400 meshes.

[0005] Polyphenylene sulfide resin 30% to 50%, the particle size of polyphenylene sulfide resin is 200 mesh to 400 mesh. As a film-forming aid, it is one of the most stable resins in thermoplastic polymer materials. It is beneficial to improve the aggregation performance, promote the plastic flow and elastic deformation of the polymer, and has excellent insulation, temperature resistance, hardness, chemical corrosion resistance, wear resistance, etc.

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

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

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

[0009] Furthermore, the structural formula of the fluorinated polyimide resin is: Wherein, n is 20 to 70.

[0010] Fluorinated polyimide resin is a film-forming matrix with a high content of fluorine atoms, which can increase the hydrophobicity of the coating, making it have good self-cleaning properties and good corrosion resistance. It can effectively prevent impurities such as water and oil from sticking to the surface of the equipment and causing slow corrosion during equipment operation and maintenance. The functional groups such as ether bonds and hydroxyl groups it contains can increase the adhesion effect of the coating. It is a resin with strong adhesion and is beneficial to increase the hardness of the coating.

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

[0012] The structure of the quaternary ammonium salt side group polyimide resin contains a phosphorylcholine group with bactericidal ability. It is a phosphorus-containing, quaternary ammonium salt group with excellent antibacterial properties, which is beneficial to improve the antibacterial properties of the coating and is a more efficient barrier polymer. Therefore, it can achieve the effect of expelling marine organisms from the side without causing pollution to the marine environment.

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

[0014] The perfluorinated long-chain side-group polyimide resin has an extremely high content of fluorine atoms, which enhances the corrosion resistance of the entire coating. Fluorine is the element with the highest electronegativity in the periodic table (electronegativity is about 4.0), which means that it has a strong ability to attract electrons. The high electronegativity enables fluorine atoms to form very stable compounds with many other elements, and these compounds generally have high chemical stability. The chemical bonds formed by fluorine atoms with other elements (such as CF bonds) have high bond energy. For example, the bond energy of the CF bond is about 485 kJ / mol, which is much higher than the CH bond (about 413 kJ / mol) and the C-Cl bond (about 375 kJ / mol). The high bond energy makes fluorine compounds more stable and less likely to be destroyed in high temperature, high pressure and corrosive environments. The small size and high charge density of fluorine atoms give it low polarizability, which means that it is not easily polarized or deformed. Low polarizability makes it difficult for the molecular structure of fluorine compounds to be distorted or broken when attacked by external chemicals, thereby improving their corrosion resistance. The chemical structure formed by fluorine atoms and other atoms can form a dense inert surface layer, which can effectively block external chemicals and moisture. This inert surface layer can prevent corrosive media (such as acids, alkalis, salts, etc.) from directly contacting the material surface, thereby protecting the material from corrosion. In addition, the introduction of fluorine atoms also enhances the hydrophobicity and oleophobicity of the resin. Based on this, it can be immersed in seawater for a long time without any corrosion, and the waterproof performance of the coating can be improved.

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

[0016] Secondly, a method for preparing a fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating is proposed, which is used for preparing the fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating, and the steps include: Step 1, weighing 49% to 60% of the prepared fluorine-containing polyimide resin, weighing 30% to 50% of the polyphenylene sulfide resin, weighing 0 to 15% of the prepared quaternary ammonium salt side group polyimide resin, weighing 0 to 15% of the prepared perfluorinated long chain side group polyimide resin, and weighing 0 to 1% of the antifouling filler; Step 2: Mix 49% to 60% of the fluorinated polyimide resin weighed in step 1, 30% to 50% of the polyphenylene sulfide resin, 0 to 15% of the quaternary ammonium salt side group polyimide resin, 0 to 15% of the perfluorinated long chain side group polyimide resin and 0 to 1% of the antifouling filler by a high mixer to obtain a fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating. The high mixer is an ultra-high-speed airflow blending pulverizer, and the components are pulverized and fully mixed by the high mixer.

[0017] Furthermore, the fluorinated polyimide resin is prepared by the following steps: Step 10, adding diphenyl ether tetracarboxylic dianhydride, hexafluorodiamine and dimethylformamide into a reaction container at a molar ratio of 1:1:10 to 25; Step 11, stirring at 10°C to 15°C for 18 to 24 hours in a nitrogen or argon environment, then pouring the resulting reaction solution into ethanol, collecting the precipitate, and drying to obtain polyamic acid powder, and finally thermally imidizing at 200°C to 230°C for 8 to 12 hours to obtain a fluorinated polyimide resin.

[0018] Further, the quaternary ammonium salt side group polyimide resin is prepared by the following steps: Step 100, under the protection of nitrogen or argon, dissolving an aromatic diamine containing phosphorus and quaternary ammonium salt groups in m-cresol, controlling the solid content to be 5% to 10%, adding diphenyl ether tetracarboxylic dianhydride and a catalyst isoquinoline or benzoic acid at 0°C to 25°C, reacting for 1 hour to 4 hours, then reacting at 80°C to 100°C for 1 hour to 4 hours, and finally reacting at 180°C to 200°C for 18 hours to 24 hours; Step 101, dissolving the obtained reaction product in methanol and collecting the precipitate; Step 102, rinsing with methanol and drying to obtain a quaternary ammonium salt side group polyimide resin.

[0019] Further, the perfluorinated long-chain side-group polyimide resin is prepared by the following steps: Step 1000, under the protection of nitrogen or argon, dissolving a perfluorinated long-chain aromatic diamine in m-cresol, controlling the solid content to be 5% to 10%, adding diphenyl ether tetracarboxylic dianhydride and a catalyst isoquinoline or benzoic acid at 0°C to 25°C, reacting for 1 to 4 hours, then reacting at 80°C to 100°C for 1 to 4 hours, and finally reacting at 180°C to 200°C for 18 to 24 hours; Step 1001, dissolving the obtained reaction product in methanol and collecting the precipitate; Step 1002, rinsing with methanol and drying to obtain a perfluorinated long-chain side-group polyimide resin.

[0020] Thirdly, a method for applying a fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating is proposed, and the application of the fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating comprises the following steps: Step a, pre-treating the metal substrate surface by degreasing it through sandblasting, polishing, etc.

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

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

[0023] The advantages of the above technical solution are: The fluorinated polyimide composite antifouling, anticorrosion and wear-resistant powder coating provided by the present invention has simple ingredients and synergistic effects among the components, which greatly improves the antifouling, anticorrosion and wear-resistant properties of the coating prepared from the coating, and can provide wear-resistant and anticorrosion protection for the substrate.

[0024] Specifically, due to the high content of fluorine atoms in the polyimide resin, the surface water contact angle of the composite coating formed by the coating can reach 86 to 110 degrees. The fluorine-containing resin has low surface energy, can reduce the adhesion of microorganisms, has good chemical stability, and has a certain anti-corrosion effect in seawater. Starting from the material itself, the hydrophobicity of the coating is increased by polyimide modification, so that it has good self-cleaning properties. The asymmetric molecular structure and the large trifluoromethyl-substituted structure will reduce the dielectric constant of the material, and a new material with both wear resistance and low dielectric constant requirements can be realized, so that the anti-fouling and anti-corrosion coating can effectively prevent corrosion from external substances and play a good protective role on the equipment.

[0025] Specifically, due to the addition of quaternary ammonium salt side-group polyimide resin and perfluorinated long-chain side-group polyimide resin, the attachment of marine organisms is inhibited without causing fatal harm to marine organisms and affecting the local marine ecosystem, thereby reducing the drawbacks of humans poisoning marine organisms by using toxic heavy metals such as self-polishing organotin for a long time.

[0026] In summary, the preparation method provided by the present invention can obtain a powder coating with excellent properties, high mechanical strength of the coating film, strong adhesion, high coating adhesion, impact resistance, high temperature oxidation resistance, high stability, and good wear resistance, and the use of the powder coating can enhance the anti-corrosion protection effect on ships. DETAILED DESCRIPTION

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

[0028] The structural formula of the above-mentioned fluorinated polyimide resin is: Wherein, n is 20 to 70.

[0029] The structural formula of 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 is prepared by the following method: adding diphenyl ether tetracarboxylic dianhydride (1 mol, 310 g), hexafluorodiamine (1 mol, 366 g) and dimethylformamide (20 mol, 1460 g) into a reaction container, stirring uniformly at a speed of 500 r / min for 18 hours at a temperature of 15° C. in a nitrogen environment, then pouring the reaction product obtained above into a mixture of ethanol and water, collecting the precipitate by suction filtration, vacuum drying at 80° C. to obtain polyamic acid powder, and finally thermal imidization at 230° C. for 8 hours to obtain the fluorinated polyimide resin.

[0032] The quaternary ammonium salt side group polyimide resin is prepared by the following method: under the protection of nitrogen, aromatic diamine containing phosphorus and quaternary ammonium salt groups (0.1 mol, 69.6 g) and meta-cresol (8.4 mol, 907.2 g) are added into a reaction container for dissolution, diphenyl ether tetracarboxylic dianhydride (0.1 mol, 31.0 g) and catalyst isoquinoline (0.004 mol, 0.5 g) are added at 15° C., reacted for 2 hours, then reacted at 80° C. for 4 hours, and finally reacted at 200° C. for 18 hours, the obtained reaction product is dissolved in methanol, and the precipitate is collected, rinsed with methanol, and dried to obtain the quaternary ammonium salt side group polyimide resin.

[0033] Among them, the perfluoro long-chain side-group polyimide resin is prepared by the following method: under the protection of nitrogen, perfluoro long-chain group-containing aromatic diamine (0.1 mol, 58.3 g) and m-cresol (7.4 mol, 803.7 g) are added into a reaction container for dissolution, diphenyl ether tetracarboxylic dianhydride (0.1 mol, 31.0 g) and catalyst benzoic acid (0.004 mol, 0.5 g) are added at 15°C, reacted for 2 hours, then reacted at 80°C for 4 hours, and finally reacted at 200°C for 18 hours, the obtained reaction product is dissolved in methanol, and the precipitate is collected, rinsed with methanol, and dried to obtain the perfluoro long-chain side-group polyimide resin.

[0034] This embodiment provides a method for preparing a fluorinated polyimide composite antifouling, anticorrosive, and wear-resistant powder coating, which specifically comprises the following steps: The raw materials are weighed according to the proportion, and a high-speed mixer is used to blend, crush and mix the raw materials evenly under ultra-high-speed airflow to obtain a fluorinated polyimide composite anti-fouling, anti-corrosion and wear-resistant powder coating.

[0035] Preferably, the particle size of the fluorine-containing polyimide resin, polyphenylene sulfide resin, quaternary ammonium salt side group polyimide resin and perfluorinated long chain side group 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-scale antifouling filler is 5nm to 150nm.

[0036] This embodiment also provides a method for using the above-mentioned fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating, which specifically includes 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°C for 30 minutes for 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 on the metal workpiece pretreated in step 1. After spraying for 2 minutes, transfer it to the curing room and cure it at 340°C for 10 minutes. Then take out the metal workpiece and quench it.

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

[0039] The preparation method and application method of the fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating and its components involved in this embodiment are the same as the process proposed in Example 1, so they are not repeated in this embodiment.

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

[0041] The preparation method and application method of the fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating and its components involved in this embodiment are the same as the process proposed in Example 1, so they are not repeated in this embodiment.

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

[0043] The preparation method and application method of the fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating and its components involved in this embodiment are the same as the process proposed in Example 1, so they are not repeated in this embodiment.

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

[0045] The preparation method and application method of the fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating and its components involved in this embodiment are the same as the process proposed in Example 1, so they are not repeated in this embodiment.

[0046] Example 6 A fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating comprises, by mass percentage, 49% of fluorinated polyimide resin, 35.5% of polyphenylene sulfide resin, 15% of quaternary ammonium salt side-group polyimide resin and 0.5% of pyrithione copper.

[0047] The preparation method and application method of the fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating and its components involved in this embodiment are the same as the process proposed in Example 1, so they are not repeated in this embodiment.

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

[0049] The preparation method and application method of the fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating and its components involved in this embodiment are the same as the process proposed in Example 1, so they are not repeated in this embodiment.

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

[0051] The preparation method and application method of the fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating and its components involved in this comparative example are the same as the process proposed in Example 1, so they are not repeated in this example.

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

[0053] The preparation method and application method of the fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating and its components involved in this comparative example are the same as the process proposed in Example 1, so they are not repeated in this example.

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

[0055] The preparation method and application method of the fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating and its components involved in this comparative example are the same as the process proposed in Example 1, so they are not repeated in this example.

[0056] In order to investigate the fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coatings prepared in the embodiments and comparative examples, tests on hardness, impact resistance, adhesion, biological resistance and salt spray resistance were carried out. The test standards and results are shown in Table 1.

[0057] Table 1 Comparison of test standards and test results of various embodiments and comparative examples From the changes in the components and content of the powder coatings of Examples 1 to 7 and Comparative Examples 1 to 3, combined with the detection structures of the various properties in Table 1, it can be seen that: (1) When nano-sized cuprous oxide and zinc pyrithione are used as antifouling fillers, the adhesion of the powder coating can be significantly improved compared with nano-sized zinc oxide and cuprous thiocyanate. However, the change of the antifouling filler has little effect on the hardness, impact resistance, biological resistance and salt spray resistance of the powder coating. It can be seen from the table that with the use of nano-sized cuprous oxide and zinc pyrithione as antifouling fillers, the adhesion of the powder coating is the greatest.

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

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

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

[0061] (5) Example 6 Compared with Example 4, Example 6 uses copper pyrithione as the antifouling filler. After the replacement, it is found that it has a greater impact on the adhesion ability and impact resistance of the coating, and both show a downward trend.

[0062] (6) Compared with Examples 4 and 6, Example 7 does not use antifouling filler. As the antifouling filler is omitted, the adhesion ability of Example 7 is decreased compared with Example 4, while the adhesion ability and impact resistance are improved compared with Example 6.

[0063] (7) In Comparative Examples 1 to 3, the prepared powder coatings lacked the quaternary ammonium salt side group polyimide resin compared to Examples 1 to 7. As the quaternary ammonium salt side group polyimide resin was omitted, the corresponding powder coatings all showed the problem of partial corrosion in terms of microbial corrosion resistance. Therefore, it can be seen that the addition or not of the quaternary ammonium salt side group polyimide resin will have a significant impact on the anti-corrosion performance of the powder coating. In addition, in Comparative Example 3, when the anti-fouling filler was not used, the adhesion ability of the powder coating was improved because there were no hard particles in the powder coating.

[0064] The above description is only 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 changes and modifications 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 is also intended to include these modifications and variations.

Claims

1. A fluorinated polyimide composite antifouling, anticorrosive, and wear-resistant powder coating, characterized in that: In terms of mass percentage, it includes: Fluorinated polyimide resin 49% to 60%; Polyphenylene sulfide resin 30% to 50%; Quaternary ammonium salt side group polyimide resin 0 to 15%; Perfluorinated long chain side group polyimide resin 0 to 15%; Antifouling filler 0 to 1%.

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

3. The fluorinated polyimide composite antifouling, anticorrosive, and wear-resistant powder coating according to claim 1, characterized in that: The structural formula of quaternary ammonium salt side group polyimide resin is: 。 4. The fluorinated polyimide composite antifouling, anticorrosive, 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, anticorrosive, and wear-resistant powder coating according to claim 1, characterized in that: The antifouling filler is a mixture of one or more of nano cuprous oxide, nano zinc oxide, cuprous thiocyanate, zinc pyrithione, alloy powder and copper pyrithione.

6. A method for preparing a fluorinated polyimide composite antifouling, anticorrosive, and wear-resistant powder coating, characterized in that: The preparation method of the fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating according to any one of claims 1 to 5 comprises the following steps: Step 1, weighing 49% to 60% of the prepared fluorine-containing polyimide resin, weighing 30% to 50% of the polyphenylene sulfide resin, weighing 0 to 15% of the prepared quaternary ammonium salt side group polyimide resin, weighing 0 to 15% of the prepared perfluorinated long chain side group polyimide resin, and weighing 0 to 1% of the antifouling filler; Step 2: Mix 49% to 60% of the fluorinated polyimide resin weighed in step 1, 30% to 50% of the polyphenylene sulfide resin, 0 to 15% of the quaternary ammonium salt side group polyimide resin, 0 to 15% of the perfluorinated long chain side group polyimide resin and 0 to 1% of the antifouling filler by a high-speed mixer to obtain a fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating.

7. The method for preparing the fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating according to claim 6, characterized in that: The fluorinated polyimide resin is prepared by the following steps: Step 10, adding diphenyl ether tetracarboxylic dianhydride, hexafluorodiamine and dimethylformamide into a reaction container at a molar ratio of 1:1:10 to 25; Step 11, stirring at 10°C to 15°C for 18 to 24 hours in a nitrogen or argon environment, then pouring the resulting reaction solution into ethanol, collecting the precipitate, and drying to obtain polyamic acid powder, and finally thermally imidizing at 200°C to 230°C for 8 to 12 hours to obtain a fluorinated polyimide resin.

8. The method for preparing the fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating according to claim 6, characterized in that: The quaternary ammonium salt side group polyimide resin is prepared by the following steps: Step 100, under the protection of nitrogen or argon, dissolving an aromatic diamine containing phosphorus and quaternary ammonium salt groups in m-cresol, controlling the solid content to be 5% to 10%, adding diphenyl ether tetracarboxylic dianhydride and a catalyst isoquinoline or benzoic acid at 0°C to 25°C, reacting for 1 hour to 4 hours, then reacting at 80°C to 100°C for 1 hour to 4 hours, and finally reacting at 180°C to 200°C for 18 hours to 24 hours; Step 101, dissolving the obtained reaction product in methanol and collecting the precipitate; Step 102, rinsing with methanol and drying to obtain a quaternary ammonium salt side group polyimide resin.

9. The method for preparing the fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating according to claim 6, characterized in that: The perfluorinated long-chain side-group polyimide resin is prepared by the following steps: Step 1000, under the protection of nitrogen or argon, dissolving a perfluorinated long-chain aromatic diamine in m-cresol, controlling the solid content to be 5% to 10%, adding diphenyl ether tetracarboxylic dianhydride and a catalyst isoquinoline or benzoic acid at 0°C to 25°C, reacting for 1 to 4 hours, then reacting at 80°C to 100°C for 1 to 4 hours, and finally reacting at 180°C to 200°C for 18 to 24 hours; Step 1001, dissolving the obtained reaction product in methanol and collecting the precipitate; Step 1002, rinsing with methanol and drying to obtain a perfluorinated long-chain side-group polyimide resin.

10. An application method of a fluorinated polyimide composite antifouling, anticorrosive, and wear-resistant powder coating, characterized in that: The application of the fluorinated polyimide composite antifouling, anticorrosive and wear-resistant powder coating according to any one of claims 1 to 5 comprises the steps of: Step a, pretreating the surface of the metal substrate; Wherein, the metal substrate is one or more of stainless steel, aluminum alloy, carbon steel, copper alloy, and titanium alloy; Step b, washing the surface of the metal substrate with water; Step c, baking the metal substrate in an oven at 340° C. to 350° C. for 30 to 40 minutes; Step d, spraying the fluorinated polyimide composite antifouling, anticorrosive, and wear-resistant powder coating on the metal substrate obtained in step c by using an electrostatic spray gun; The electrostatic spray gun is set with a compressed air pressure of 0.5 MPa to 0.7 MPa, an electrostatic spraying voltage of 60 kV to 90 kV, a current of 10 μA to 20 μA, and a spraying distance of 15 cm to 30 cm; Step e, placing the sprayed metal substrate in a curing chamber and curing it at 330° C. to 340° C. for 10 to 25 minutes.

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