Long-acting low surface energy coating with high recoatability and preparation method, application thereof

Abstract

This invention provides a long-lasting, low-surface-energy coating with high recoatability, its preparation method, and its applications. The coating, by weight, mainly consists of the following components: 0.1–5 parts of alkane-based and amino-based modified inorganic / organic nanoparticles, 0.2–10 parts of a base resin for the coating, and 85–99.7 parts of an aqueous solvent. The preparation method of this invention is simple, mild, and environmentally friendly, requiring no complex equipment. The resulting coating exhibits good superhydrophobicity, environmental adaptability, and pH responsiveness, and possesses high recoatability, extending its service life. Furthermore, when the coating suffers localized damage or ages after prolonged use, a new coating can be obtained through recoating.

Description

Technical Field

[0001] This invention belongs to the field of low surface energy coating technology, and relates to a long-lasting low surface energy coating with high recoatability, its preparation method, and its application. Background Technology

[0002] In recent years, my country's construction industry has developed rapidly. As one of the most important consumables in the construction and other industries, promoting the green and low-carbon manufacturing and application of coatings is of great significance for the sustainable development of these sectors. However, traditional coatings have gradually revealed shortcomings in terms of mechanical stability, environmental adaptability, and recoatability. On the one hand, during long-term service, they are susceptible to the effects of rainwater, acids and alkalis, ultraviolet rays, temperature changes, and mold, resulting in yellowing, chalking, and blistering. They are also prone to physical damage such as friction and adhesion, leading to localized breakage and ultimately a significant reduction in performance and substantial maintenance costs. On the other hand, the renovation of old coatings usually requires the complete removal of the old coating and the application of a new one, which not only consumes a lot of manpower and resources but also causes serious resource waste and environmental pollution. Therefore, developing low surface energy coatings that combine mechanical stability, environmental adaptability, and recoatability is of great importance.

[0003] Chinese patent CN110295000B discloses a method for preparing a recoatable, low-viscosity, high-film-thickness polyethylene ester coating. The method involves first preparing a modified vinyl ester resin using vinyl ester resin and a sulfur-containing modified compound, then sequentially adding an defoamer, wetting and dispersing agent, flake filler, phosphate, pigments and fillers, and a composite functional rheology modifier. After thorough mixing, the coating is obtained. The coating disclosed in this patent exhibits significantly improved weather resistance, enhanced adhesion, and extended recoating time. However, the coating surface prepared by this patent lacks superhydrophobic properties, and the preparation process is cumbersome and time-consuming.

[0004] Chinese patent CN117106352A discloses a method for preparing a modified coating with hydrophilic-hydrophobic conversion properties that can be recoated. The method involves first filling at least one of a silicone-acrylic emulsion and a fluorinated acrylate with hydrophobic nano-silica, then adding a surfactant with sulfonic acid groups at the end, stirring thoroughly, diluting, and finally spraying to obtain the hydrophobic coating. The preparation method disclosed in this patent is simple and allows for secondary coating. However, the coating disclosed in this patent introduces fluorinated groups during its preparation process, which can easily cause environmental pollution.

[0005] Chinese patent CN118389015A discloses a method for preparing a water-based, low-surface-energy, recoatable coating. The method involves mixing methyltriethoxysilane, water, and acetic acid, heating the mixture to obtain a pre-hydrolyzed siloxane, and then adding a hydrophobic inorganic nanoparticle dispersion and an acidified acrylate aqueous solution to prepare the water-based, low-surface-energy, recoatable coating. The coating prepared by this patent exhibits strong hydrophobicity and excellent recoatability. However, the prepared coating has limited functionality, a single substrate, and poor adhesion and abrasion resistance, thus limiting its practical application.

[0006] While a few methods and processes have been used to develop recoatable low surface energy surfaces, existing preparation methods suffer from drawbacks such as cumbersome processes, lack of environmental friendliness, limited substrate selection, and restricted application scope. Therefore, developing a multifunctional, recoatable, long-lasting low surface energy coating that is applicable to various substrates, has a simple and environmentally friendly preparation method, and exhibits stable performance is more meaningful for practical applications. Summary of the Invention

[0007] In view of the problems raised by the prior art, the present invention provides a long-lasting low surface energy coating with high recoatability, its preparation method and application. The preparation method is simple, mild and environmentally friendly, and does not require complicated instruments and equipment. At the same time, the coating itself has good superhydrophobicity, environmental adaptability and pH responsiveness, and endows it with high recoatability, extending the service life of the coating. When the coating is locally damaged or ages after long-term use, a new coating can be obtained by recoating.

[0008] To achieve the above objectives, the present invention employs a technical solution consisting of the following technical measures.

[0009] In one aspect, the present invention provides a long-lasting low surface energy coating with high recoatability, which is mainly composed of the following components by mass: 0.1 to 5 parts of alkane-based and amino-based modified inorganic / organic nanoparticles, 0.2 to 10 parts of coating matrix resin and 85 to 99.7 parts of aqueous solvent;

[0010] The inorganic / organic nanoparticles are modified by combining alkane-based and amino-based treatment agents, wherein the amino-based treatment agent is any one or more compounds in the following structural formulas:

[0011]

[0012] In the formula, R1 and R2 are H, CH3 or C2H5 respectively, and R is an active group that can react with hydroxyl groups, such as Si(CH3O)3, Si(C2H5O)3, CH2=CHCOO, CH2=C(CH3)COO, SH, OH or Si(CH3)2Cl.

[0013] Alkane-based treatment agents are any one or more compounds with the following structural formulas:

[0014]

[0015] In the formula, n≥7, R is an active group that can react with hydroxyl groups, such as Si(CH3O)3, Si(C2H5O)3, CH2=CHCOO, CH2=C(CH3)COO, SH, OH or Si(CH3)2Cl, and X is Cl or Br.

[0016] In this document, the inorganic / organic nanoparticles are the nanoparticle fillers conventionally selected for hydrophobic coatings in the prior art, or the nanoparticle fillers that have been modified to be hydrophobic. Those skilled in the art can know the conventional inorganic / organic nanoparticle filler selections that can be used in hydrophobic coatings based on the prior art.

[0017] To better illustrate the present invention and provide a technical solution for reference, the inorganic / organic nanoparticles are selected from any one or more of nano-silica, nano-titanium dioxide, nano-zinc oxide, nano-alumina, nano-magnesium oxide, polyurea-formaldehyde nanoparticles, polystyrene nanoparticles, polyacrylamide nanoparticles, and polymethyl methacrylate nanoparticles.

[0018] In this paper, the combined modification of inorganic / organic nanoparticles with alkane-based and amino-based treatment agents is a product obtained by modifying inorganic / organic nanoparticles with two or more different treatment agents, and can follow the conventional modification conditions and process operations of silane coupling agents when modifying inorganic / organic nanoparticles.

[0019] In one of the technical solutions, the alkane treatment agent is specifically selected from any one or more of dimethyltetradecyl[3-(trimethoxysilyl)propyl]ammonium chloride, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, dimethyltetradecyl[3-(trimethoxysilyl)propyl]ammonium bromide, and dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium bromide.

[0020] In one of the technical solutions, the amino-based treatment agent is specifically selected from any one or more of (N,N-dimethyl-3-aminopropyl)trimethoxysilane, (N-methyl-3-aminopropyl)trimethoxysilane, (3-aminopropyl)trimethoxysilane, and (N,N-diethyl-3-aminopropyl)trimethoxysilane.

[0021] It should be noted that when the alkane-based and amino-based treatment agents are combined for modification, the addition ratio, modification conditions, and process operation can all follow common knowledge methods in the field, or the relevant instructions for use of the specific treatment agent or the usage methods recorded in existing literature.

[0022] To better illustrate the present invention and provide a reference technical solution, the mass ratio of the alkane treatment agent to the inorganic / organic nanoparticles is (8-95):100; the mass ratio of the amino treatment agent to the inorganic / organic nanoparticles is (26-65):100.

[0023] In one more preferred embodiment, the mass ratio of the alkane-based treatment agent to the inorganic / organic nanoparticles is (8-47):100; and the mass ratio of the amino-based treatment agent to the inorganic / organic nanoparticles is (45-65):100.

[0024] It should be emphasized that when the alkane-based and amino-based treatment agents are used for joint modification, the modification conditions and process operations can follow methods known in the art. Therefore, the technical solutions provided below in this invention do not imply the sole designation or limitation of the method for preparing inorganic / organic nanoparticles by joint modification of the alkane-based and amino-based treatment agents.

[0025] In one preferred embodiment, the method for preparing inorganic / organic nanoparticles modified by the combined use of alkane-based and amino-based treatment agents mainly includes the following steps:

[0026] Alkane-based treatment agents, amino-based treatment agents, and inorganic / organic nanoparticles were dispersed in solvent A and stirred for 12–48 h. After separation, washing, and drying, inorganic / organic nanoparticles modified by alkane-based and amino-based treatment agents were obtained.

[0027] In the above technical solution, solvent A is a conventional solvent choice for modifying inorganic / organic nanoparticles with silane coupling agents, such as anhydrous ethanol, n-hexane, cyclohexane, dichloromethane, n-heptane, n-octane, acetone, benzene, toluene, and ethyl acetate; more preferably, solvent A is a mixed solution of ethanol and water with a mass ratio of (25-75):(25-75). Typically, solvent A is used in a material-to-liquid mass ratio of 1:(50-150).

[0028] In this document, the matrix resin for coatings is a conventional choice of resin used as a matrix material in hydrophobic coatings, such as any one of epoxy resin, silicone resin, polyacrylic resin, polyurethane, and urea-formaldehyde resin.

[0029] In this paper, the aqueous solvent referred to is a conventional choice for hydrophobic coatings. However, it should be noted that because the inorganic / organic nanoparticles modified by the combined alkane and amino treatment agents exhibit hydrophilic-hydrophobic conversion properties and superhydrophobic characteristics in non-acidic environments, direct mixing with non-acidic solvents would result in uneven dispersion. Therefore, in the actual preparation of long-lasting low surface energy coatings, the inorganic / organic nanoparticles modified by the combined alkane and amino treatment agents are dispersed in an acidic solution, mixed evenly, and then an alkaline solution is added to restore the neutrality. Finally, the coating matrix resin is added and mixed evenly to obtain a long-lasting low surface energy coating with high recoatability. However, it should be noted that because the final solution is restored to neutrality, from the perspective of the constituent components, it is essentially still a conventional neutral aqueous solvent.

[0030] In one technical solution, in order to ensure sufficient dispersion, the aqueous solvent is a neutral solvent composed of an acidic aqueous solution with pH = 1 to 3 and an alkaline aqueous solution with pH = 11 to 13; for example, any one or more of sulfuric acid aqueous solution, hydrochloric acid aqueous solution, and acetic acid aqueous solution with pH = 1 to 3, or any one or more of sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, and sodium carbonate aqueous solution with pH = 11 to 13.

[0031] On the other hand, the preparation method of the above-mentioned long-lasting low surface energy coating with high recoatability mainly includes the following steps: alkane-based treatment agent and amino-based treatment agent are combined to modify inorganic / organic nanoparticles and disperse them in an acidic aqueous solution. After mixing evenly, an alkaline aqueous solution is added and mixed to restore neutrality. Then, a base resin for coating is added and mixed evenly to obtain a long-lasting low surface energy coating with high recoatability.

[0032] In one preferred embodiment, the long-lasting low surface energy coating with high recoatability further comprises, by weight parts:

[0033] Additives: 1-25 parts.

[0034] The additive is one or more of pigments, thickeners, defoamers, leveling agents, antioxidants, and rust inhibitors. Typically, the pigments, thickeners, defoamers, leveling agents, antioxidants, and rust inhibitors mentioned above are commonly known and used.

[0035] In one more preferred embodiment, to further improve overall performance, the mass ratio of the inorganic / organic nanoparticles modified by the combined alkane and amino treatment agents to the base resin for the coating is 1:(1-5).

[0036] It should be noted that the long-lasting low surface energy coating provided by this invention follows the conventional coating method for hydrophobic coatings in the chemical industry. For example, after applying a layer of adhesive to a smooth substrate, the long-lasting low surface energy coating is applied to its surface, and after drying, a long-lasting low surface energy coating with high recoatability can be obtained; or it can be directly coated on the surface of the substrate.

[0037] Typically, the coating method is one of spraying, brushing, or dipping; the adhesive includes, but is not limited to, 3M adhesive, commonly used coating resin adhesive, inorganic adhesive, etc.; the substrate is any one of concrete, glass, wood, stainless steel, copper, iron, aluminum, polyvinylidene fluoride film, polyethylene terephthalate film, cellulose film, polyurethane foam, sponge, cement board, ceramics, textiles, or paper products.

[0038] Furthermore, the present invention also provides a method for recoating the above-mentioned long-lasting low surface energy coating with high recoatability, which mainly includes the following steps:

[0039] The coating formed by the long-lasting low surface energy coating with high recoatability is brought into contact with an acidic solution with pH = 1 to 3. After at least 30 seconds, the coating with the high recoatability long-lasting low surface energy coating is applied to the contact area. After drying, the recoating is achieved.

[0040] In this document, the separation, washing, and drying processes described are all common knowledge operations in the field. In industrial scale-up, those skilled in the art can choose more suitable process operation methods.

[0041] In this document, the stirring reaction is a stirring reaction conventionally used in the art, including magnetic stirring or mechanical stirring. Those skilled in the art can choose a suitable stirring reaction method according to the production scale or current process conditions. In one technical solution, the stirring reaction can be carried out at a stirring rate of 100-300 rpm.

[0042] The present invention has the following beneficial effects:

[0043] (1) In the long-lasting low surface energy coating with high recoatability provided by the present invention, by using alkane-based treatment agents and amino-based treatment agents to modify inorganic / organic nanoparticles, on the one hand, a micro-nano structure is constructed on the surface of the coating, and on the other hand, a hydrophilic-hydrophobic conversion structure is introduced, which provides excellent superhydrophobic properties and pH responsiveness. Its static water contact angle is higher than 150°, its roll-off angle is lower than 10°, and it can achieve reversible switching of surface water contact angle under acid and alkali stimulation, thereby using this reversible switching to achieve the recoatability of the old coating.

[0044] (2) The present invention proposes a combination of alkane-based and amino-based treatment agents to modify inorganic / organic nanoparticles. Both the alkane-based and amino-based treatment agents contain trimethoxysilylpropyl groups. During the modification process, the trimethoxysilylpropyl groups undergo hydrolysis and condensation reactions with the hydroxyl groups on the surface of the inorganic / organic nanoparticles. The resulting silicon-oxygen covalent bonds are stably and tightly connected with the inorganic / organic nanoparticles, ensuring the superhydrophobic stability of the coating.

[0045] (3) The long-lasting low surface energy coating with high recoatability provided by the present invention provides good interfacial adhesion, good environmental adaptability, and good mechanical / physical / chemical stability by adding a base resin for coating to the coating, and can be applied to a variety of substrates.

[0046] (4) The long-lasting low surface energy coating with high recoatability provided by the present invention achieves the optimal technical effect through the specific selection of coating component content ratio: if the inorganic / organic nanoparticles modified by the alkane treatment agent and amino treatment agent and the base resin of the coating are higher than the mass percentage range proposed by the present invention, it will cause them to be unable to disperse uniformly to form a uniform system, resulting in uneven spraying and failure to achieve the ideal effect; if the amount of alkane treatment agent and amino treatment agent is lower than the mass percentage range proposed by the present invention, the resulting coating only has a certain environmental adaptability and does not have superhydrophobic properties, pH responsiveness and recoatability.

[0047] (5) The alkane-based and amino-based treatment agents proposed in this invention are used to modify inorganic / organic nanoparticles. Through specific selection, the best technical effect can be achieved, and the nanoparticles can fully react with each other.

[0048] (6) The preparation method of this coating is simple. The whole process is carried out at room temperature and pressure. There are no complex chemical reactions and no toxic byproducts are produced. The whole preparation process is green and environmentally friendly. It does not require complex and expensive instruments and equipment. It can be prepared and produced on a large scale with low cost. It has a wide range of practical application value and is conducive to industrial application and promotion. Attached Figure Description

[0049] Figure 1 The image shows the FT-IR image of silica nanoparticles modified by the combined alkane and amino treatment agents obtained in step (1) of Example 1 of this invention.

[0050] Figure 2 This is a scanning electron microscope (SEM) image of the surface microstructure of the long-lasting low surface energy coating with high recoatability obtained in Example 1 of the present invention.

[0051] Figure 3 The static contact angle and roll-off angle of the long-lasting low surface energy coating with high recoatability obtained in Example 2 of the present invention are shown in the test diagram.

[0052] Figure 4 The bar chart shows the static contact angle test results of the long-lasting low surface energy coating with high recoatability obtained in Example 3 of the present invention on water, seawater, coffee, cola, tea and milk.

[0053] Figure 5 The graph shows the change of water contact angle with the number of abrasion cycles during the abrasion process of the long-lasting low surface energy coating with high recoatability obtained in Example 4 of the present invention under a 200g load using 2000-grit sandpaper.

[0054] Figure 6 The graphs show the test results of the long-lasting low surface energy coating with high recoatability obtained in Example 6 of the present invention for different surface wettability of acidic, neutral and alkaline droplets.

[0055] Figure 7 This is a bar graph comparing the adhesion between the interfaces before and after recoating of the long-lasting low surface energy coating with high recoatability obtained in Example 7 of the present invention.

[0056] Figure 8 The above are bar graphs comparing the static contact angles of the long-lasting low surface energy coatings with high recoatability obtained in Examples 1-8 of this invention under acidic and neutral droplet conditions. Detailed Implementation

[0057] To further understand the present invention, preferred embodiments are described below with reference to examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims. Those skilled in the art can refer to the content of this document to appropriately improve the process parameters. In particular, it should be noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included within the scope of the present invention. The methods and applications of the present invention have been described through preferred embodiments, and those skilled in the art can obviously make modifications or appropriate changes and combinations to the methods and applications described herein without departing from the content, spirit and scope of the present invention to realize and apply the technology of the present invention. Although it is believed that those skilled in the art will fully understand the following terms, the following definitions are set forth to help illustrate the subject matter disclosed in the present invention.

[0058] In one aspect, the present invention provides a long-lasting low surface energy coating with high recoatability, which is mainly composed of the following components by mass: 0.1 to 5 parts of alkane-based and amino-based modified inorganic / organic nanoparticles, 0.2 to 10 parts of coating matrix resin and 85 to 99.7 parts of aqueous solvent;

[0059] The inorganic / organic nanoparticles are modified by a combination of alkane-based and amino-based treatment agents, wherein the amino-based treatment agent is any one or more compounds in the following structural formulas:

[0060]

[0061] In the formula, R1 and R2 are H, CH3 or C2H5 respectively, and R is an active group that can react with hydroxyl groups, such as Si(CH3O)3, Si(C2H5O)3, CH2=CHCOO, CH2=C(CH3)COO, SH, OH or Si(CH3)2Cl.

[0062] Alkane-based treatment agents are any one or more compounds with the following structural formulas:

[0063]

[0064] In the formula, n≥7, R is an active group that can react with hydroxyl groups, such as Si(CH3O)3, Si(C2H5O)3, CH2=CHCOO, CH2=C(CH3)COO, SH, OH or Si(CH3)2Cl, and X is Cl or Br.

[0065] In this document, the inorganic / organic nanoparticles are the nanoparticle fillers conventionally selected for hydrophobic coatings in the prior art, or the nanoparticle fillers that have been modified to be hydrophobic. Those skilled in the art can know the conventional inorganic / organic nanoparticle filler selections that can be used in hydrophobic coatings based on the prior art.

[0066] To better illustrate the present invention and provide a reference embodiment, the inorganic / organic nanoparticles are selected from any one or more of nano-silica, nano-titanium dioxide, nano-zinc oxide, nano-alumina, nano-magnesium oxide, polyurea-formaldehyde nanoparticles, polystyrene nanoparticles, polyacrylamide nanoparticles, and polymethyl methacrylate nanoparticles.

[0067] In this paper, the combined modification of inorganic / organic nanoparticles with alkane-based and amino-based treatment agents is a product obtained by modifying inorganic / organic nanoparticles with two or more different treatment agents, and can follow the conventional modification conditions and process operations of silane coupling agents when modifying inorganic / organic nanoparticles.

[0068] In one embodiment, the alkane treatment agent is specifically selected from any one or more of dimethyltetradecyl[3-(trimethoxysilyl)propyl]ammonium chloride, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, dimethyltetradecyl[3-(trimethoxysilyl)propyl]ammonium bromide, and dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium bromide.

[0069] In one embodiment, the amino-based treatment agent is specifically selected from any one or more of (N,N-dimethyl-3-aminopropyl)trimethoxysilane, (N-methyl-3-aminopropyl)trimethoxysilane, (3-aminopropyl)trimethoxysilane, and (N,N-diethyl-3-aminopropyl)trimethoxysilane.

[0070] It should be noted that when the alkane-based and amino-based treatment agents are combined for modification, the addition ratio, modification conditions, and process operation can all follow common knowledge methods in the field, or the relevant instructions for use of the specific treatment agent or the usage methods recorded in existing literature.

[0071] To better illustrate the present invention and provide a reference embodiment, the mass ratio of the alkane treatment agent to the inorganic / organic nanoparticles is (8-95):100, for example 8:100, 9:100, 10:100, 11:100, 12:100, 13:100, 14:100, 15:100, 16:100, 17:100, 18:100, 19:100, 20:100, 21:100, 22:100. 23:100, 24:100, 25:100, 26:100, 27:100, 28:100, 29:100, 30:100, 31:100, 32:100, 33:100, 34:100, 35:100, 36:100, 37:100, 38:100, 39:100, 40:100, 41:100, 42:100, 43:100, 44:100, 45:100, 46:10 0, 47:100, 48:100, 49:100, 50:100, 55:100, 60:100, 65:100, 70:100, 75:100, 80:100, 85:100, 90:100, 95:100 or any range or point value between them; the mass ratio of the amino-based treatment agent to the inorganic / organic nanoparticles is (26-65):100, for example 26:100, 30:100, 35:100, 4 0:100, 45:100, 46:100, 47:100, 48:100, 49:100, 50:100, 51:100, 52:100, 53:100, 54:100, 55:100, 56:100, 57:100, 58:100, 59:100, 60:100, 61:100, 62:100, 63:100, 64:100, 65:100, or any range or point value between them.

[0072] In one more preferred embodiment, the mass ratio of the alkane treatment agent to the inorganic / organic nanoparticles is (8-47):100; and the mass ratio of the amino treatment agent to the inorganic / organic nanoparticles is (45-65):100.

[0073] It should be emphasized that when the alkane-based and amino-based treatment agents are used for joint modification, the modification conditions and process operations can follow methods known in the art. Therefore, the technical solutions provided below in this invention do not imply the sole designation or limitation of the method for preparing inorganic / organic nanoparticles by joint modification of the alkane-based and amino-based treatment agents.

[0074] In one preferred embodiment, the method for preparing inorganic / organic nanoparticles modified by the combined use of alkane-based and amino-based treatment agents mainly includes the following steps:

[0075] Alkane-based treatment agents, amino-based treatment agents, and inorganic / organic nanoparticles were dispersed in solvent A and stirred for 12–48 h. After separation, washing, and drying, inorganic / organic nanoparticles modified by alkane-based and amino-based treatment agents were obtained.

[0076] In the above embodiments, solvent A is a conventional solvent choice for modifying inorganic / organic nanoparticles with silane coupling agents, such as anhydrous ethanol, n-hexane, cyclohexane, dichloromethane, n-heptane, n-octane, acetone, benzene, toluene, and ethyl acetate; more preferably, solvent A is a mixed solution of ethanol and water in a mass ratio of (25-75):(25-75). Typically, solvent A is used in a material-to-liquid mass ratio of 1:(50-150).

[0077] In this document, the matrix resin for coatings is a conventional choice of resin used as a matrix material in hydrophobic coatings, and in one embodiment, for example, any one of epoxy resin, silicone resin, polyacrylic resin, polyurethane, and urea-formaldehyde resin.

[0078] In this paper, the aqueous solvent referred to is a conventional choice for hydrophobic coatings. However, it should be noted that because the inorganic / organic nanoparticles modified by the combined alkane and amino treatment agents exhibit hydrophilic-hydrophobic conversion properties and superhydrophobic characteristics in non-acidic environments, direct mixing with non-acidic solvents would result in uneven dispersion. Therefore, in the actual preparation of long-lasting low surface energy coatings, the inorganic / organic nanoparticles modified by the combined alkane and amino treatment agents are dispersed in an acidic solution, mixed evenly, and then an alkaline solution is added to restore the neutrality. Finally, the coating matrix resin is added and mixed evenly to obtain a long-lasting low surface energy coating with high recoatability. However, it should be noted that because the final solution is restored to neutrality, from the perspective of the constituent components, it is essentially still a conventional neutral aqueous solvent.

[0079] In one embodiment, to ensure sufficient dispersion, the aqueous solvent is a neutral solvent composed of an acidic aqueous solution with pH = 1 to 3 and an alkaline aqueous solution with pH = 11 to 13; for example, any one or more of sulfuric acid aqueous solution, hydrochloric acid aqueous solution, and acetic acid aqueous solution with pH = 1 to 3, or any one or more of sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, and sodium carbonate aqueous solution with pH = 11 to 13.

[0080] In one embodiment, the 0.1 to 5 parts of alkane-based and amino-based treatment agents are used to jointly modify inorganic / organic nanoparticles, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.8, 1, 1.1, 1.2, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 4.8, 5 parts, or any range or point value between them; the 0.2 to 10 parts of the coating matrix resin, for example, 0.2, 0.3, 0.4, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5 parts. 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, 10 parts, or any range or point value between them; 85 to 99.7 parts of aqueous solvent, such as 85 parts, 85.1 parts, 85.2 parts, 85.3 parts, 85.4 parts, 85.5 parts, 86 parts, 87 parts, 88 parts, 89 parts, 90 parts, 91 parts, 92 parts, 93 parts, 94 parts, 95 parts, 96 parts, 97 parts, 98 parts, 99 parts, 99.1 parts, 99.2 parts, 99.3 parts, 99.4 parts, 99.5 parts, 99.6 parts, 99.7 parts, or any range or point value between them.

[0081] On the other hand, the preparation method of the above-mentioned long-lasting low surface energy coating with high recoatability mainly includes the following steps: alkane-based treatment agent and amino-based treatment agent are combined to modify inorganic / organic nanoparticles and disperse them in an acidic aqueous solution. After mixing evenly, an alkaline aqueous solution is added and mixed to restore neutrality. Then, a base resin for coating is added and mixed evenly to obtain a long-lasting low surface energy coating with high recoatability.

[0082] In one preferred embodiment, the long-lasting low surface energy coating with high recoatability further comprises, by weight parts:

[0083] Additives: 1-25 parts.

[0084] The additive is one or more of pigments, thickeners, defoamers, leveling agents, antioxidants, and rust inhibitors. Typically, the pigments, thickeners, defoamers, leveling agents, antioxidants, and rust inhibitors mentioned above are commonly known and used.

[0085] In one more preferred embodiment, to further improve the overall performance, the mass ratio of the inorganic / organic nanoparticles modified by the combined alkane and amino treatment agents to the base resin for the coating is 1:(1-5), for example 1:1, 1:1.5, 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5 or any range or point value between them.

[0086] It should be noted that the long-lasting low surface energy coating provided by this invention follows the conventional coating method for hydrophobic coatings in the chemical industry. For example, after applying a layer of adhesive to a smooth substrate, the long-lasting low surface energy coating is applied to its surface, and after drying, a long-lasting low surface energy coating with high recoatability can be obtained; or it can be directly coated on the surface of the substrate.

[0087] Typically, the coating method is one of spraying, brushing, or dipping; the adhesive includes, but is not limited to, 3M adhesive, commonly used coating resin adhesive, inorganic adhesive, etc.; the substrate is any one of concrete, glass, wood, stainless steel, copper, iron, aluminum, polyvinylidene fluoride film, polyethylene terephthalate film, cellulose film, polyurethane foam, sponge, cement board, ceramics, textiles, or paper products.

[0088] Furthermore, the present invention also provides a method for recoating the above-mentioned long-lasting low surface energy coating with high recoatability, which mainly includes the following steps:

[0089] The coating formed by the long-lasting low surface energy coating with high recoatability is brought into contact with an acidic solution with pH = 1 to 3. After at least 30 seconds, the coating with the high recoatability long-lasting low surface energy coating is applied to the contact area. After drying, the recoating is achieved.

[0090] In this document, the separation, washing, and drying processes described are all common knowledge operations in the field. In industrial scale-up, those skilled in the art can choose more suitable process operation methods.

[0091] In this document, the stirring reaction is a stirring reaction conventionally used in the art, including magnetic stirring or mechanical stirring. Those skilled in the art can choose a suitable stirring reaction method according to the production scale or current process conditions. In one technical solution, the stirring reaction can be carried out at a stirring rate of 100-300 rpm.

[0092] The present application will be further explained in detail below with reference to embodiments. However, those skilled in the art should understand that these embodiments are provided for illustrative purposes only and are not intended to limit the present application.

[0093] Example

[0094] The embodiments of this application will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be construed as limiting the scope of this application. Where specific conditions are not specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Where the manufacturers of reagents or instruments are not specified, they are all commercially available conventional products. This application should not be construed as being limited to the specific embodiments described.

[0095] 1. Raw materials

[0096] Silica nanoparticles, titanium dioxide nanoparticles, zinc oxide nanoparticles, magnesium oxide nanoparticles, aluminum oxide nanoparticles, and polyurea-formaldehyde nanoparticles were purchased from Shanghai Aladdin Chemical Co., Ltd.

[0097] Dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium bromide, dimethyltetradecyl[3-(trimethoxysilyl)propyl]ammonium chloride, and dimethyldodecyl[3-(trimethoxysilyl)propyl]ammonium bromide are provided by Beijing Bailingwei Technology Co., Ltd.

[0098] (N,N-Dimethyl-3-aminopropyl)trimethoxysilane, (N-methyl-3-aminopropyl)trimethoxysilane, (N,N-diethyl-3-aminopropyl)trimethoxysilane, and (3-aminopropyl)trimethoxysilane are provided by Beijing Bailingwei Technology Co., Ltd.

[0099] The epoxy resin was supplied by Dow Chemical Company Ltd., the polysiloxane resin by Wacker Chemie Ltd., and the polyurethane by Shanghai Maclean Biotechnology Co., Ltd.

[0100] Ethanol, concentrated sulfuric acid, concentrated hydrochloric acid, acetic acid, sodium hydroxide, potassium hydroxide, and potassium carbonate were supplied by Chengdu Kelong Chemical Industry Reagent Co., Ltd.

[0101] The glass sheets were supplied by a glass factory in China, while the melamine foam and polyurethane foam were supplied by a local foam factory. Ready-mixed concrete, timber, steel plates, plastics, aluminum plates, cotton, coffee, cola, tea, and milk were all purchased from local supermarkets.

[0102] 2. Testing Methods

[0103] (1) The infrared spectra of inorganic / organic nanoparticles modified by the combination of alkane-based and amino-based treatment agents were tested by Fourier transform infrared spectroscopy (FT-IR, Nicolet 6700, Thermo Fisher, USA).

[0104] (2) The microstructure of the coating surface was observed by scanning electron microscopy (SEM, Philips XL-3, FEI Co., USA).

[0105] (3) The hydrophobic properties of the coating surface were tested using a contact angle tester (Zhongchen Digital Equipment Co. Ltd. Shanghai, China).

[0106] (4) Referring to the test method in GB / T 5210-2006, place the 150×70mm sample in an environment with a temperature of (23±2)℃ and a relative humidity of (50±5)%. Then, fix the test column (bottom diameter 30mm) coated with adhesive onto the sample surface. After the adhesive has cured, immediately place the test assembly under a tensile testing machine and apply tensile stress in a direction perpendicular to the plane of the sample. Record the tensile force at which the test assembly fails. The breaking strength can be expressed by the following formula, in MPa:

[0107] σ=F / A

[0108] (Where: F is the destructive force, in N; A is the area of ​​the test column, in mm²) 2 )

[0109] The test was repeated three times, and the average value was taken as the adhesion strength.

[0110] Example 1

[0111] Example 1 provides a method for preparing a long-lasting, low-surface-energy coating with high recoatability, specifically including the following steps:

[0112] (1) Preparation of inorganic / organic nanoparticles modified by a combination of alkane and amino treatment agents: 0.5 g of silica nanoparticles with a size of approximately 30 nm were dispersed in a mixed solution of 24 g of water and 25.06 g of anhydrous ethanol. Then, 0.13 g of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and 0.31 g of (N,N-dimethyl-3-aminopropyl)trimethoxysilane were added. After stirring for 24 h, the mixture was separated and washed to obtain silica nanoparticles modified by a combination of alkane and amino treatment agents. Figure 1 As shown, the FT-IR spectrum of the silica nanoparticles modified by the combined alkane and amino treatment agents obtained in this embodiment is at 2930 / 2854 cm⁻¹. 1 The peak is the position of the CH stretching vibration peak, at 1448 cm⁻¹. 1 The peak is the bending vibration peak of CH, at 473 cm⁻¹. 1 804cm- 1 And 1107cm- 1 The peaks were all Si-O peaks, proving the successful synthesis of modified inorganic / organic nanoparticles.

[0113] (2) Preparation of long-lasting low surface energy coating with high recoatability: 0.1g of silica nanoparticles modified by the alkane treatment agent and amino treatment agent obtained in step (1) were dispersed into 49.75g of acid solution with pH=1. After mixing evenly, 49.75g of alkaline solution with pH=13 was added. After stirring for 5min, 0.4g of waterborne epoxy resin (Ep) was added. Finally, the mixture was evenly mixed to obtain a long-lasting low surface energy coating with high recoatability.

[0114] To facilitate testing, the long-lasting low surface energy coating obtained in step (2) was sprayed onto the concrete surface and dried at room temperature to obtain a long-lasting low surface energy coating with high recoatability.

[0115] like Figure 2 As shown in the SEM image of the long-lasting low surface energy coating obtained in this embodiment, the surface has a water contact angle of 155.3° and a roll-off angle of 1.3°. In addition, the concrete substrate in this embodiment can also be replaced by other smooth substrates such as glass, iron sheets, wood, and aluminum sheets.

[0116] Example 2

[0117] Example 2 provides a method for preparing a long-lasting, low-surface-energy coating with high recoatability, specifically including the following steps:

[0118] (1) Preparation of inorganic / organic nanoparticles modified by alkane and amino treatment agents: 0.67 g of titanium dioxide nanoparticles with a size of about 15 nm were dispersed in a mixed solution of 23 g of water and 25.93 g of anhydrous ethanol. Then, 0.07 g of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium bromide and 0.33 g of (N,N-dimethyl-3-aminopropyl)trimethoxysilane were added. After stirring for 36 h, the mixture was separated and washed to obtain titanium dioxide nanoparticles modified by alkane and amino treatment agents.

[0119] (2) Preparation of long-lasting low surface energy coating with high recoatability: 0.11g of titanium dioxide nanoparticles modified by the alkane treatment agent and amino treatment agent obtained in step (1) were dispersed into 39.72g of acid solution with pH=1. After mixing evenly, 39.72g of alkaline solution with pH=13 was added. After stirring for 5min, 0.45g of waterborne epoxy resin (Ep) was added. After mixing evenly, a long-lasting low surface energy coating with high recoatability was obtained.

[0120] To facilitate testing, the long-lasting low surface energy coating obtained in step (2) was sprayed onto the surface of the printing paper. After drying, a long-lasting low surface energy coating with high recoatability was obtained.

[0121] like Figure 3 As shown in the diagram, the contact angle test results of the long-lasting low surface energy coating obtained in this embodiment show a water contact angle of 154.5° and a roll-off angle of 1.7°. Furthermore, the printing paper substrate in this example can also be replaced by other substrates with rough surfaces, such as wood, filter paper, textiles, or cellulose membranes.

[0122] Example 3

[0123] Example 3 provides a method for preparing a long-lasting, low-surface-energy coating with high recoatability, specifically including the following steps:

[0124] (1) Preparation of inorganic / organic nanoparticles modified by alkane and amino treatment agents: 1g of alumina nanoparticles with a size of about 30 nm were added to a mixed solution of 48.62g of water and 50g of anhydrous ethanol, and then 0.1g of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and 0.28g of [3-(N,N-dimethylamino)propyl]trimethoxysilane were added. After stirring and reacting for 36h, the alumina nanoparticles modified by alkane and amino treatment agents were obtained by separation and washing.

[0125] (2) Preparation of long-lasting low surface energy coating with high recoatability: 2.0g of alkane treatment agent and amino treatment agent obtained in step (1) are combined to modify alumina nanoparticles, dispersed in 23.5g of acid solution with pH=1, mixed evenly, and then 23.5g of alkaline solution with pH=13 is added. After stirring for 5min, 1.0g of polysiloxane resin (PSi) is added and mixed evenly to obtain long-lasting low surface energy coating with high recoatability.

[0126] To facilitate testing, the long-lasting low surface energy coating obtained in step (2) is sprayed onto the fabric surface by spraying. After drying, a long-lasting low surface energy coating with high recoatability is obtained.

[0127] like Figure 4 As shown, the long-lasting low surface energy coating obtained in this embodiment achieves a water contact angle of 154.0°, and its static contact angle with common household contaminants such as seawater, coffee, cola, tea, and milk also exceeds 150°. In daily life, it can prevent contamination from liquid pollutants such as seawater, coffee, cola, tea, and milk, while also exhibiting a self-cleaning effect against solid contaminants such as dust and copper sulfate. Furthermore, if the fabric coating is contaminated with castor oil, most of the oil stains on the coating surface can be effectively removed by stirring and washing in an acidic solution, demonstrating a cleaning effect.

[0128] Example 4

[0129] Example 4 provides a method for preparing a long-lasting, low-surface-energy coating with high recoatability, specifically including the following steps:

[0130] (1) Preparation of inorganic / organic nanoparticles modified by alkane and amino treatment agents: 0.5 g of silica nanoparticles with a size of about 15 nm were dispersed in a mixed solution of 36.81 g of water and 12.3 g of anhydrous ethanol. Then, 0.07 g of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and 0.32 g of (N,N-dimethyl-3-aminopropyl)trimethoxysilane were added. After stirring for 24 h, the silica nanoparticles modified by alkane and amino treatment agents were obtained.

[0131] (2) Preparation of a long-lasting low surface energy coating with high recoatability: 0.2g of silica nanoparticles modified with alkane and amino treatment agents obtained in step (1) were dispersed in 10g of an acid solution with pH=1. After mixing evenly, 10g of an alkaline solution with pH=13 was added. After stirring for 5min, 0.5g of polysiloxane resin (PSi) was added and mixed evenly to obtain a long-lasting low surface energy coating with high recoatability. For convenient testing, the long-lasting low surface energy coating obtained in step (2) was applied to the glass surface by spraying and dried at room temperature to obtain a long-lasting low surface energy coating with high recoatability.

[0132] The long-lasting low surface energy coating obtained in this embodiment has a water contact angle of 153.0° and a roll-off angle of 2.1°. Due to the strong adhesion of epoxy resin, the coating exhibits good mechanical stability, such as... Figure 5 As shown, the surface wetting properties of the coating after 100 (20m) sandpaper abrasion cycles.

[0133] Example 5

[0134] Example 5 provides a method for preparing a long-lasting, low-surface-energy coating with high recoatability, specifically including the following steps:

[0135] (1) Preparation of inorganic / organic nanoparticles modified by alkane and amino treatment agents: 0.5g of magnesium oxide nanoparticles with a size of about 10 nm and 0.5g of alumina nanoparticles with a size of about 1 nm were mixed and dispersed together in a mixed solution of 24.86g of water and 73.38g of anhydrous ethanol. Then, 0.18g of dimethyldodecyl[3-(trimethoxysilyl)propyl]ammonium bromide and 0.18g of dimethyltetradecyl[3-(trimethoxysilyl)propyl]ammonium bromide were added, along with 0.4g of (3-aminopropyl)trimethoxysilane. After stirring for 96h, the mixture was separated and washed to obtain zinc oxide and alumina nanoparticles modified by alkane and amino treatment agents.

[0136] (2) Preparation of long-lasting low surface energy coating with high recoatability: 2g of zinc oxide and aluminum oxide nanoparticles modified by the alkane treatment agent and amino treatment agent obtained in step (1) are dispersed in 17g of acid solution with pH=1. After mixing evenly, 17g of alkaline solution with pH=13 is added. After stirring for 5min, 2g of polysiloxane resin (PSi) and 2g of polyurethane are added. After mixing evenly, a long-lasting low surface energy coating with high recoatability is obtained.

[0137] To facilitate testing, the long-lasting low surface energy coating obtained in step (2) was applied to the surface of polyurethane foam by dip coating. After drying, a long-lasting low surface energy coating with high recoatability was obtained.

[0138] The long-lasting low surface energy coating obtained in this embodiment has a water contact angle of 154.8° and a roll-off angle of 3.2°. In addition, the polyurethane foam substrate in this embodiment can also be replaced by other loose and porous substrates such as melamine foam, polyurethane foam, or cotton.

[0139] Example 6

[0140] Example 6 provides a method for preparing a long-lasting, low-surface-energy coating with high recoatability, specifically including the following steps:

[0141] (1) Preparation of inorganic / organic nanoparticles modified by alkane-based and amino-based treatment agents: 0.5g of zinc oxide particles with a size of about 10 nm and 1.5g of polyurea formaldehyde nanoparticles with a size of about 100 nm were mixed and dispersed together in a mixed solution of 20.84g of water and 25g of anhydrous ethanol. Then, a mixture of 0.52g of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, 0.62g of (N,N-dimethyl-3-aminopropyl)trimethoxysilane and 0.64g of (N,N-diethyl-3-aminopropyl)trimethoxysilane was added. After stirring for 72h, the mixture was separated and washed to obtain zinc oxide and polyurea formaldehyde nanoparticles modified by alkane-based and amino-based treatment agents.

[0142] (2) Preparation of long-lasting low surface energy coating with high recoatability: 2g of zinc oxide modified by alkane treatment agent and amino treatment agent obtained in step (1) and polyurea nanoparticles are dispersed in 45g of acid solution with pH=1. After mixing evenly, 45g of alkaline solution with pH=13 is added. After stirring for 5min, 8g of epoxy resin (Ep) is added and mixed evenly to obtain long-lasting low surface energy coating with high recoatability.

[0143] To facilitate testing, the long-lasting low surface energy coating obtained in step (2) was sprayed onto the concrete surface and dried at room temperature to obtain a long-lasting low surface energy coating with high recoatability.

[0144] like Figure 6 As shown, the long-lasting low surface energy coating obtained in this embodiment exhibits a hydrophilic state with an acidic droplet contact angle of 0°, while neutral and alkaline droplets show a superhydrophobic state with contact angles greater than 150°. Furthermore, the concrete substrate in this example can also be replaced by other smooth substrates such as glass or wood.

[0145] Example 7

[0146] Example 7 provides a method for preparing a long-lasting, low-surface-energy coating with high recoatability, specifically including the following steps:

[0147] (1) Preparation of inorganic / organic nanoparticles modified by alkane and amino treatment agents: 1.5g of silica nanoparticles with a size of about 100 nm were dispersed in a mixed solution of 47.39g of water and 50g of anhydrous ethanol. Then, 0.32g of two mixed alkane treatment agents, dimethyltetradecyl[3-(trimethoxysilyl)propyl]ammonium chloride and dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium bromide, and 0.62g of (N-methyl-3-aminopropyl)trimethoxysilane were added. After stirring for 32h, silica nanoparticles modified by alkane and amino treatment agents were obtained by separation and washing.

[0148] (2) Preparation of long-lasting low surface energy coating with high recoatability: 1.0g of silica nanoparticles modified by alkane treatment agent and amino treatment agent obtained in step (1) were dispersed into 23.25g of acid solution with pH=1. After mixing evenly, 23.25g of alkaline solution with pH=13 was added. After stirring for 5min, 2.5g of polysiloxane resin (PSi) was added and mixed evenly to obtain long-lasting low surface energy coating with high recoatability.

[0149] To facilitate testing, the long-lasting low surface energy coating obtained in step (2) was sprayed onto the concrete surface and dried at room temperature to obtain a long-lasting low surface energy coating with high recoatability.

[0150] like Figure 7 As shown, the long-lasting low surface energy coating obtained in this embodiment has an adhesion of up to 5.22 MPa; after recoating, the adhesion still reaches 5.34 MPa. Furthermore, the concrete substrate in this example can also be replaced by other smooth substrates such as glass and wood.

[0151] Example 8

[0152] Example 8 provides a method for preparing a long-lasting, low-surface-energy coating with high recoatability, specifically including the following steps:

[0153] (1) Preparation of inorganic / organic nanoparticles modified by alkane and amino treatment agents: 0.5g of silica nanoparticles with a size of about 30 nm were dispersed in a mixed solution of 24g water and 24.8g anhydrous ethanol, and then 0.39g of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and 0.31g of (N,N-dimethyl-3-aminopropyl)trimethoxysilane were added. After stirring for 24h, the mixture was separated and washed to obtain silica nanoparticles modified by alkane and amino treatment agents.

[0154] (2) Preparation of long-lasting low surface energy coating with high recoatability: 0.1g of silica nanoparticles modified by alkane treatment agent and amino treatment agent obtained in step (1) were dispersed into 49.75g of acid solution with pH=1. After mixing evenly, 49.75g of alkaline solution with pH=13 was added. After stirring for 5min, 0.4g of waterborne epoxy resin (Ep) was added. Finally, the mixture was evenly mixed to obtain long-lasting low surface energy coating with high recoatability.

[0155] To facilitate testing, the long-lasting low surface energy coating obtained in step (2) was sprayed onto the concrete surface and dried at room temperature to obtain a long-lasting low surface energy coating with high recoatability.

[0156] The long-lasting low surface energy coating obtained in this embodiment has a contact angle of 148.83° for acidic droplets, exhibiting a hydrophobic state, and a contact angle of 154.25° for neutral droplets, exhibiting a superhydrophobic state. Compared with Example 1, although the coating in this embodiment still exhibits different surface wettability in acidic and neutral environments, it cannot effectively switch between hydrophilic and hydrophobic states, resulting in extremely poor recoating performance.

[0157] like Figure 8 As shown, a lateral comparison was made of the static contact angles of the long-lasting low surface energy coatings obtained in Examples 1 to 8 under acidic and neutral droplet conditions. It was found that during the coating preparation process, the long-lasting low surface energy coatings obtained exhibited different hydrophilic-hydrophobic conversion characteristics under different proportions of alkane-based treatment agents, amino-based treatment agents and inorganic / organic nanoparticles. Among them, Examples 1 and 6 showed the best overall performance.

[0158] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A long-lasting low surface energy coating with high recoatability, characterized in that... The main components by mass are: 0.1-5 parts of inorganic nanoparticles modified by a combination of alkane and amino treatment agents, 0.2-10 parts of coating matrix resin, and 85-99.7 parts of aqueous solvent. The inorganic nanoparticles are modified by combining alkane-based and amino-based treatment agents, wherein the amino-based treatment agent is any one or more compounds in the following structural formulas: ； In the formula, R1 and R2 are H, CH3 or C2H5 respectively, and R is Si(CH3O) or Si(C2H5O)3; Alkane-based treatment agents are any one or more compounds with the following structural formulas: ； In the formula, n≥7, R is Si(CH3O)3 or Si(C2H5O)3, and X is Cl or Br; The inorganic nanoparticles include any one or more of nano-silica, nano-titanium dioxide, nano-zinc oxide, nano-alumina, and nano-magnesium oxide. The mass ratio of the alkane-based treatment agent to the inorganic nanoparticles is (8~42):100; the mass ratio of the amino-based treatment agent to the inorganic nanoparticles is (26~65):

100. The preparation method of the long-lasting low surface energy coating with high recoatability mainly includes the following steps: Inorganic nanoparticles modified by combining alkane-based and amino-based treatment agents are dispersed in an acidic aqueous solution, mixed evenly, and then an alkaline aqueous solution is added to restore the solution to neutrality. Finally, a base resin for coating is added and mixed evenly to obtain a long-lasting low surface energy coating with high recoatability.

2. The long-lasting low surface energy coating according to claim 1, characterized in that: The alkane-based treatment agents include any one or more of dimethyltetradecyl[3-(trimethoxysilyl)propyl]ammonium chloride, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, dimethyltetradecyl[3-(trimethoxysilyl)propyl]ammonium bromide, and dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium bromide; the amino-based treatment agents include any one or more of (N,N-dimethyl-3-aminopropyl)trimethoxysilane, (N-methyl-3-aminopropyl)trimethoxysilane, (3-aminopropyl)trimethoxysilane, and (N,N-diethyl-3-aminopropyl)trimethoxysilane.

3. The long-lasting low surface energy coating according to claim 1, characterized in that: The preparation method of inorganic nanoparticles modified by the combined use of alkane-based and amino-based treatment agents mainly includes the following steps: Alkane-based treatment agents, amino-based treatment agents, and inorganic nanoparticles were dispersed in solvent A and stirred for 12-48 hours. After separation, washing, and drying, inorganic nanoparticles modified by alkane-based and amino-based treatment agents were obtained.

4. The long-lasting low surface energy coating according to claim 1, characterized in that: The base resin for the coating includes any one of epoxy resin, silicone resin, polyacrylic resin, polyurethane, and urea-formaldehyde resin.

5. The long-lasting low surface energy coating according to claim 1, characterized in that: The mass ratio of the inorganic nanoparticles modified by the combined alkane and amino treatment agents to the base resin for coatings is 1:(1~5).

6. The application method of the long-lasting low surface energy coating as described in claim 1, characterized in that: It involves applying an adhesive to a smooth substrate, then applying a long-lasting low surface energy coating to its surface, and drying it to obtain a long-lasting low surface energy coating with high recoatability. Or it can be directly coated onto the surface of the substrate; The substrate material is any one of concrete, glass, wood, stainless steel, copper, iron, aluminum, polyvinylidene fluoride film, polyethylene terephthalate film, cellulose film, polyurethane foam, sponge, cement board, ceramics, textiles or paper products.

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