A coating material with long-acting super-amphiphobic property, a coating layer and a preparation method thereof

Abstract

The application relates to the technical field of coatings, in particular to a coating with long-acting super-biphobic performance, a coating layer and a preparation method thereof. The coating with long-acting super-biphobic performance provided by the application comprises a bottom coating and a surface coating, the bottom coating comprises an epoxy resin and an amine curing agent; the surface coating comprises A-type POSS nano-particles and B-type POSS nano-particles, the A-type POSS nano-particles are obtained by reacting fluorine-containing siloxane, amino silane coupling agent and tetraethyl orthosilicate, and the B-type POSS nano-particles are obtained by reacting fluorine-containing siloxane, epoxy silane coupling agent and tetraethyl orthosilicate. The application solves the problem of limited chemical bond points of surface grafting modification of silica microspheres in the prior art.

Description

Technical Field

[0001] This application relates to the field of coating technology, and in particular to a coating, coating material and preparation method thereof with long-lasting superhydrophobic properties. Background Technology

[0002] Domestic and international research indicates that the construction theory of superhydrophobic surfaces mainly relies on the Young model, the Wenzel model, and the Cassie model. The Young model states that the droplet contact angle of a smooth surface is determined solely by its surface chemical properties; therefore, reducing the surface free energy of the coating material becomes a direct way to improve its hydrophobic properties. However, this method has limitations—even when using materials with the lowest surface energy to modify smooth surfaces, the maximum water contact angle of the prepared hydrophobic surface is only 119°, failing to achieve a superhydrophobic state greater than 150°. Based on this, the Wenzel and Cassie models further clarify that the construction of superhydrophobic surfaces requires building micro / nano rough structures on the basis of low surface energy materials. This conclusion presents new challenges for the design, preparation, and application processes of superhydrophobic coatings.

[0003] In the research process of superhydrophobic coatings, researchers have prepared superhydrophobic surfaces with ideal micro-nano rough structures using fine processing techniques such as etching and plasma methods. However, although these fine processing techniques can accurately construct excellent micro-nano rough surfaces in the laboratory, they are not inherently suitable for engineering applications. The core reason is that these methods are complex, the equipment is expensive, and they are only applicable to substrates of specific sizes, which cannot meet the actual needs of large-scale production and on-site construction.

[0004] In contrast, superhydrophobic coatings, which can be applied using a spray coating process, offer an effective solution to the aforementioned challenges. These coatings directly disperse functional fillers with micro / nano structures and a resin matrix in a liquid system. After spraying, the desired micro / nano rough structure spontaneously forms on the coating surface as the solvent evaporates or the resin cures. This technological approach is not only simple in equipment and low in cost, but also highly efficient in application. Furthermore, it is adaptable to coating needs on substrates of arbitrary shapes and large areas, thus becoming a mainstream and feasible technological direction driving superhydrophobic coatings from the laboratory to industrial applications.

[0005] In the field of superhydrophobic coatings, current technologies all use ordinary resins as the binder layer and hydrophobically modified micro / nanoparticles as the surface layer. Superhydrophobic coatings typically rely on physical adsorption or simple intercalation for adhesion, resulting in a fragile micro / nano rough structure (often based on silica and other microparticles) with weak bonding to the substrate. For example, patent CN119684872A discloses a wear-resistant and weather-resistant superhydrophobic coating, its preparation method, and its application. This technology uses long-chain perfluorosilanes to initially modify the low surface energy of nanoparticles. During use, the low surface energy material is easily worn away and the structure is easily damaged, leading to rapid performance degradation and poor long-term durability. In particular, the traditional method of surface grafting modification using silica microspheres results in a clear interface between the microparticles and the resin matrix, limited chemical bonding points, and the grafting uniformity and density are limited by surface reactions, thus facing a performance bottleneck.

[0006] Therefore, it is essential to provide a superhydrophobic coating that can improve interfacial adhesion and long-term durability. Summary of the Invention

[0007] This application provides a coating with long-lasting superhydrophobic properties to solve the problem of limited chemical bonding points in the surface grafting modification of silica microspheres used in related technologies.

[0008] In a first aspect, this application provides a coating with long-lasting superhydrophobic properties, comprising a base coat and a top coat. The base coat comprises an epoxy resin and an amine curing agent. The top coat comprises type A POSS nanoparticles and type B POSS nanoparticles. The type A POSS nanoparticles are obtained by reacting a fluorosiloxane, an aminosilane coupling agent, and tetraethyl orthosilicate. The type B POSS nanoparticles are obtained by reacting a fluorosiloxane, an epoxy silane coupling agent, and tetraethyl orthosilicate.

[0009] In some embodiments, the mass ratio of the epoxy resin to the amine curing agent is 2-3:1, and the undercoat composed of epoxy resin and amine curing agent can form an active adhesive layer rich in unreacted epoxy groups and amino groups on the substrate surface.

[0010] In some embodiments, the epoxy resin is selected from any one of bisphenol A type epoxy resin E-51, E-44, bisphenol F type epoxy resin F51, F-44.

[0011] In some embodiments, the amine curing agent is selected from polyamide curing agents and polyetheramine curing agents.

[0012] In some embodiments, the fluorinated siloxane is selected from any one of perfluorooctyltriethoxysilane, trifluoropropyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, and tridecafluorooctyltrimethoxysilane.

[0013] In some embodiments, the aminosilane coupling agent is selected from either KH550 or KH792.

[0014] In some embodiments, the epoxy silane coupling agent is selected from any one of KH560, KH561, and KH562.

[0015] In some embodiments, the mass ratio of fluorosiloxane, aminosilane coupling agent and tetraethyl orthosilicate is 25:6-10:4.

[0016] In some embodiments, the mass ratio of fluorosiloxane, epoxy silane coupling agent and tetraethyl orthosilicate is 10:3-5:1.

[0017] Secondly, embodiments of this application also provide a method for preparing a coating using the above-mentioned coating with long-lasting superhydrophobic properties, comprising the following steps: Step S101: Perform surface treatment on the substrate; Step S102: Weigh epoxy resin and amine curing agent, add mixed solvent, stir and disperse evenly to obtain base coat, spray the base coat onto the surface of the substrate by spraying, and let it stand at room temperature; Step S103: When the bottom coating is in a semi-cured state, mix the type A POSS nanoparticle dispersion with the curing accelerator solution and spray it onto the surface of the bottom coating. Then, spray the B layer POSS nanoparticle dispersion onto the surface of the type A POSS nanoparticle dispersion. Step S104: After spraying, the coating is cured to obtain a coating with long-lasting superhydrophobic properties.

[0018] In some embodiments, the mixed solvent is a solution of xylene and n-butanol mixed in a mass ratio of 3-5:1.

[0019] In some embodiments, the type A POSS nanoparticles are prepared by the following process: Fluorosilane, aminosilane coupling agent, and tetraethyl orthosilicate were added to a mixed solution of anhydrous ethanol and deionized water. Hydrochloric acid was added to adjust the pH to 4-5. The reaction was heated to 60-80°C. After the reaction was complete, the mixture was cooled to room temperature and distilled at 40-60°C. The resulting product was dissolved in tetrahydrofuran, then added to n-hexane, allowed to stand, filtered, washed, and dried at 60-80°C to obtain type A POSS nanoparticles. In the molecular structure of type A POSS nanoparticles, long-chain perfluoroalkyl groups providing ultra-low surface energy and amino groups (-NH2) providing reactivity are covalently bonded at the vertices of the POSS cage-like framework. Therefore, each type A POSS molecule is a nanounit possessing both superhydrophobic properties and amino reactivity.

[0020] In some embodiments, type A POSS nanoparticles are ultrasonically dispersed in hexafluoroxylene at a concentration of 2wt%-5wt% to obtain a type A POSS nanoparticle dispersion.

[0021] In some embodiments, the type B POSS nanoparticles are prepared by the following process: Fluorosiloxane, epoxysilane coupling agent, and tetraethyl orthosilicate were added to a mixed solution of anhydrous ethanol and deionized water. Hydrochloric acid was added to adjust the pH to 4-5. The reaction was heated to 60-80°C. After the reaction was complete, the mixture was cooled to room temperature and distilled at 40-60°C. The resulting product was dissolved in tetrahydrofuran, then added to n-hexane, allowed to stand, filtered, washed, and dried at 60-80°C to obtain type B POSS nanoparticles. In the molecular structure of type B POSS nanoparticles, long-chain perfluoroalkyl groups and reactive epoxy groups are covalently bonded at the vertices of the POSS cage-like framework. Therefore, each type B POSS molecule is a nanounit possessing both superhydrophobic properties and epoxy group reactivity.

[0022] In some embodiments, type B POSS nanoparticles are ultrasonically dispersed in hexafluoroxylene at a concentration of 2wt%-5wt% to obtain a type B POSS nanoparticle dispersion.

[0023] In some embodiments, the curing accelerator solution is a solution obtained by dissolving 2-ethyl-4-methylimidazole in isopropanol at a concentration of 1 wt%-3 wt%.

[0024] In some embodiments, in step S104, the curing process is as follows: first, cure at 70-90°C for 2 hours, and then cure at 120-150°C for 1 hour.

[0025] Thirdly, embodiments of this application also provide a coating with long-lasting superhydrophobic properties prepared using the above-described preparation method.

[0026] The technical solution provided in this application replaces the traditional microsphere surface grafting and uses molecular design to synthesize POSS nanoparticles that simultaneously carry low surface energy segments (fluorine chains) and reactive functional groups (amino or epoxy groups), ensuring that each nanounit has a clear function, abundant reaction sites, and uniform distribution.

[0027] The coating provided in this application forms a multi-layered, high-strength chemically bonded network between the top and bottom layers, and within the top layer. The amino groups of type A POSS react with the uncured epoxy groups in the bottom layer; the epoxy groups of type B POSS react with the unreacted amino or hydroxyl groups in the bottom layer, forming a covalently bonded "rivet" effect at the interface. Between the sequentially deposited type A and type B POSS, their amino and epoxy groups react with each other, forming a three-dimensional network structure within the top layer, with POSS nanoparticles as nodes and connected by covalent bonds. The rigid inorganic siloxane cages of POSS enhance the strength of the network framework. Ultimately, the coating forms a stable overall structure from strong adhesion at the bottom layer to a highly cross-linked network at the top layer, with the outer layer enriched with fluorocarbon chains, achieving long-lasting superhydrophobic and dihydrophobic properties.

[0028] The beneficial effects of the technical solution provided in this application include: 1. Excellent interfacial bonding and cohesive strength: This application uses two types of reactive POSS nanoparticles. The reactive functional groups on the POSS nanoparticles directly participate in the formation of high-density covalent bonds, constructing a robust chemical network at the surface-to-bottom interface and inside the surface layer. The inorganic core of POSS provides rigid support, while the organic functional groups ensure reactivity and compatibility, resulting in a significant improvement in the overall mechanical strength and adhesion of the coating. 2. Achieving long-lasting superhydrophobic and oleophobic properties: The low surface energy perfluoroalkyl chain, as an inherent part of the POSS molecule, is firmly anchored in the network through covalent bonds and is not easily peeled off under friction or solvent action; the stable nano-rough structure constructed by the POSS particles can also effectively resist physical damage, so that the hydrophobic and oleophobic properties of the coating can be maintained for a long time in harsh environments. 3. Superior dispersibility and compatibility: The organic-inorganic hybrid properties of POSS enable the coating to have better dispersibility and interfacial compatibility in organic resin systems, reducing phase separation and facilitating the formation of a more uniform and dense superhydrophobic functional layer. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a water contact angle test diagram of the coating prepared in Example 1 of this application.

[0031] Figure 2 This is a test diagram of the oil contact angle of the coating prepared in Example 1 of this application. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] This application provides a coating and coating material with long-lasting superhydrophobic properties, which can solve the problem of limited chemical bonding points in the surface grafting modification of silica microspheres in the prior art.

[0034] Example 1: Preparation of type A POSS nanoparticles: 100 mL of anhydrous ethanol and 20 mL of deionized water were added to a dry 250 mL three-necked flask. Under nitrogen protection and cooling in an ice-water bath, 5.0 g of perfluorooctyltriethoxysilane, 1.2 g of γ-aminopropyltriethoxysilane (KH550), and 0.8 g of tetraethyl orthosilicate were slowly added dropwise over 30 minutes, maintaining the system temperature below 10 °C. After the addition was complete, 0.1 mol / L hydrochloric acid aqueous solution was added to adjust the pH of the reaction system to 4. The ice bath was removed, and the reaction mixture was heated to 70 °C and refluxed for 24 hours under nitrogen protection and magnetic stirring. After the reaction was completed, the mixture was cooled to room temperature and transferred to a rotary evaporator. Most of the ethanol and water were removed by vacuum distillation at 50 °C. The obtained viscous substance was dissolved in 50 mL of tetrahydrofuran, and then added dropwise to 500 mL of n-hexane under vigorous stirring, resulting in a white precipitate. After standing and filtration, the obtained solid was washed three times with n-hexane. The product was then placed in a vacuum drying oven and dried at 60 °C for 12 hours to obtain white powdery type A POSS nanoparticles. The type A POSS nanoparticles were ultrasonically dispersed in hexafluoroxylene at a concentration of 3 wt% to obtain a type A POSS nanoparticle dispersion.

[0035] Preparation of type B POSS nanoparticles: 100 mL of anhydrous ethanol and 20 mL of deionized water were added to a dry 250 mL three-necked flask. Under nitrogen protection and cooling in an ice-water bath, 5.0 g of perfluorooctyltriethoxysilane, 1.5 g of γ-glycidoxypropyltrimethoxysilane (KH560), and 0.5 g of tetraethyl orthosilicate were slowly added dropwise over 30 minutes, maintaining the system temperature below 10 °C. After the addition was complete, 0.1 mol / L hydrochloric acid aqueous solution was added to adjust the pH of the reaction system to 4. The ice bath was removed, and the reaction mixture was heated to 70 °C and refluxed for 24 hours under nitrogen protection and magnetic stirring. After the reaction was completed, the mixture was cooled to room temperature and transferred to a rotary evaporator. Most of the ethanol and water were removed by vacuum distillation at 50 °C. The obtained viscous substance was dissolved in 50 mL of tetrahydrofuran, and then added dropwise to 500 mL of n-hexane under vigorous stirring, resulting in a white precipitate. After standing and filtration, the obtained solid was washed three times with n-hexane. The product was then placed in a vacuum drying oven and dried at 60 °C for 12 hours to obtain white powdery type B POSS nanoparticles. The type B POSS nanoparticles were ultrasonically dispersed in hexafluoroxylene at a concentration of 3 wt% to obtain a type B POSS nanoparticle dispersion.

[0036] Preparation of coatings with long-lasting superhydrophobic and amphoteric properties: (1) Sand the aluminum alloy plate with sandpaper, and clean and dry it with acetone; (2) Weigh 100 parts of bisphenol A type epoxy resin E-51 and 50 parts of polyamide curing agent (650) by weight, add xylene and n-butanol mixed in a mass ratio of 4:1, stir at high speed to disperse evenly, and obtain a base coat with a solid content of about 60%, let it stand to defoam and set aside. (3) The base coat is uniformly sprayed onto the surface of the aluminum alloy plate by spraying, with a wet film thickness of about 90 μm; it is left to stand at room temperature (25℃) for 20 minutes. At this time, the base coat has partially cross-linked and the surface has lost its fluidity but has not been completely cured (semi-cured state); 2-ethyl-4-methylimidazole is dissolved in isopropanol at a concentration of 1 wt% to obtain a curing accelerator solution. The type A POSS nanoparticle dispersion and the curing accelerator solution are mixed at a volume ratio of 10:1 and immediately sprayed onto the surface of the semi-cured base coat with a thickness of 60 μm; after an interval of 2 minutes, the type B POSS nanoparticle dispersion is directly sprayed onto the upper layer with a thickness of 15 μm; (4) After the spraying is completed, the aluminum alloy plate is cured at 80°C for 2 hours, and then cured at 150°C for 1 hour to obtain the super double hydrophobic coating aluminum alloy plate.

[0037] The water contact angle test diagram of the coating prepared in Example 1 is shown below. Figure 1 See the oil contact angle test diagram. Figure 2 .

[0038] Example 2: Preparation of type A POSS nanoparticles: 100 mL of anhydrous ethanol and 20 mL of deionized water were added to a dry 250 mL three-necked flask. Under nitrogen protection and ice-water bath cooling, 5.0 g of trifluoropropyltrimethoxysilane, 1.2 g of silane coupling agent KH792, and 0.8 g of tetraethyl orthosilicate were slowly added dropwise. The entire addition process was completed within 30 minutes, and the system temperature was maintained below 10 °C. After the addition was complete, 0.1 mol / L hydrochloric acid aqueous solution was added to adjust the pH of the reaction system to 5. The ice bath was removed, and the reaction mixture was heated to 75 °C and refluxed for 24 hours under nitrogen protection and magnetic stirring. After the reaction was completed, the mixture was cooled to room temperature and transferred to a rotary evaporator. Most of the ethanol and water were removed by vacuum distillation at 45 °C. The obtained viscous substance was dissolved in 50 mL of tetrahydrofuran, and then added dropwise to 500 mL of n-hexane under vigorous stirring, resulting in a white precipitate. After standing and filtration, the obtained solid was washed three times with n-hexane. The product was then placed in a vacuum drying oven and dried at 70 °C for 12 hours to obtain white powdery type A POSS nanoparticles. The type A POSS nanoparticles were ultrasonically dispersed in hexafluoroxylene at a concentration of 3 wt% to obtain a type A POSS nanoparticle dispersion.

[0039] Preparation of type B POSS nanoparticles: 100 mL of anhydrous ethanol and 20 mL of deionized water were added to a dry 250 mL three-necked flask. Under nitrogen protection and cooling in an ice-water bath, 5.0 g of tridecafluorooctyltrimethoxysilane, 1.5 g of γ-glycidyl etheroxypropyltrimethoxysilane (KH560), and 0.5 g of tetraethyl orthosilicate were slowly added dropwise over 30 minutes, maintaining the system temperature below 10 °C. After the addition was complete, 0.1 mol / L hydrochloric acid aqueous solution was added to adjust the pH of the reaction system to 4. The ice bath was removed, and the reaction mixture was heated to 75 °C and refluxed for 24 hours under nitrogen protection and magnetic stirring. After the reaction was completed, the mixture was cooled to room temperature and transferred to a rotary evaporator. Most of the ethanol and water were removed by vacuum distillation at 60 °C. The obtained viscous substance was dissolved in 50 mL of tetrahydrofuran, and then added dropwise to 500 mL of n-hexane under vigorous stirring, resulting in a white precipitate. After standing and filtration, the obtained solid was washed three times with n-hexane. The product was then placed in a vacuum drying oven and dried at 70 °C for 12 hours to obtain white powdery type B POSS nanoparticles. The type B POSS nanoparticles were ultrasonically dispersed in hexafluoroxylene at a concentration of 2 wt% to obtain a type B POSS nanoparticle dispersion.

[0040] Preparation of coatings with long-lasting superhydrophobic and amphoteric properties: (1) Sand the aluminum alloy plate with sandpaper, and clean and dry it with acetone; (2) Weigh 100 parts of bisphenol A type epoxy resin E-51 and 50 parts of polyamide curing agent (650) by weight, add xylene and n-butanol mixed in a mass ratio of 4:1, stir at high speed to disperse evenly, and obtain a base coat with a solid content of about 60%, let it stand to defoam and set aside. (3) The base coat is uniformly sprayed onto the surface of the aluminum alloy plate by spraying, with a wet film thickness of about 110 μm; it is left to stand at room temperature (25℃) for 20 minutes. At this time, the base coat has partially cross-linked and the surface has lost its fluidity but has not been completely cured (semi-cured state); 2-ethyl-4-methylimidazole is dissolved in isopropanol at a concentration of 1 wt% to obtain a curing accelerator solution. The type A POSS nanoparticle dispersion and the curing accelerator solution are mixed at a volume ratio of 10:1 and immediately sprayed onto the surface of the semi-cured base coat, with a thickness of 85 μm; after an interval of 2 minutes, the type B POSS nanoparticle dispersion is directly sprayed onto the upper layer, with a thickness of 10 μm; (4) After the spraying is completed, the aluminum alloy plate is cured at 85°C for 2 hours, and then cured at 145°C for 1 hour to obtain the super double hydrophobic coating aluminum alloy plate.

[0041] Example 3: Preparation of type A POSS nanoparticles: 100 mL of anhydrous ethanol and 20 mL of deionized water were added to a dry 250 mL three-necked flask. Under nitrogen protection and cooling in an ice-water bath, 5.0 g of heptadecafluorodecyltrimethoxysilane, 1.2 g of γ-aminopropyltriethoxysilane (KH550), and 0.8 g of tetraethyl orthosilicate were slowly added dropwise over 30 minutes, maintaining the system temperature below 10 °C. After the addition was complete, 0.1 mol / L hydrochloric acid aqueous solution was added to adjust the pH of the reaction system to 4. The ice bath was removed, and the reaction mixture was heated to 65 °C and refluxed for 24 hours under nitrogen protection and magnetic stirring. After the reaction was completed, the mixture was cooled to room temperature and transferred to a rotary evaporator. Most of the ethanol and water were removed by vacuum distillation at 55 °C. The obtained viscous substance was dissolved in 50 mL of tetrahydrofuran, and then added dropwise to 500 mL of n-hexane under vigorous stirring, resulting in a white precipitate. After standing and filtration, the obtained solid was washed three times with n-hexane. The product was then placed in a vacuum drying oven and dried at 70 °C for 12 hours to obtain white powdery type A POSS nanoparticles. The type A POSS nanoparticles were ultrasonically dispersed in hexafluoroxylene at a concentration of 4 wt% to obtain a type A POSS nanoparticle dispersion.

[0042] Preparation of type B POSS nanoparticles: 100 mL of anhydrous ethanol and 20 mL of deionized water were added to a dry 250 mL three-necked flask. Under nitrogen protection and cooling in an ice-water bath, 5.0 g of heptadecafluorodecyltrimethoxysilane, 1.5 g of silane coupling agent KH561, and 0.5 g of tetraethyl orthosilicate were slowly added dropwise. The entire addition process was completed within 30 minutes, and the system temperature was maintained below 10 °C. After the addition was complete, 0.1 mol / L hydrochloric acid aqueous solution was added to adjust the pH of the reaction system to 4. The ice bath was removed, and the reaction mixture was heated to 65 °C and refluxed for 24 hours under nitrogen protection and magnetic stirring. After the reaction was completed, the mixture was cooled to room temperature and transferred to a rotary evaporator. Most of the ethanol and water were removed by vacuum distillation at 60 °C. The obtained viscous substance was dissolved in 50 mL of tetrahydrofuran, and then added dropwise to 500 mL of n-hexane under vigorous stirring, resulting in a white precipitate. After standing and filtration, the obtained solid was washed three times with n-hexane. The product was then placed in a vacuum drying oven and dried at 70 °C for 12 hours to obtain white powdery type B POSS nanoparticles. The type B POSS nanoparticles were ultrasonically dispersed in hexafluoroxylene at a concentration of 2 wt% to obtain a type B POSS nanoparticle dispersion.

[0043] Preparation of coatings with long-lasting superhydrophobic and amphoteric properties: (1) Sand the aluminum alloy plate with sandpaper, and clean and dry it with acetone; (2) Weigh 100 parts of bisphenol F type epoxy resin F51 and 50 parts of polyamide curing agent (650) by weight, add xylene and n-butanol mixed solution in a mass ratio of 4:1, stir at high speed to disperse evenly, and obtain a base coating with a solid content of about 60%, let stand to defoam and set aside. (3) The base coat is uniformly sprayed onto the surface of the aluminum alloy plate by spraying, with a wet film thickness of about 120 μm; it is left to stand at room temperature (25℃) for 20 minutes. At this time, the base coat has partially cross-linked and the surface has lost its fluidity but has not been completely cured (semi-cured state); 2-ethyl-4-methylimidazole is dissolved in isopropanol at a concentration of 1 wt% to obtain a curing accelerator solution. The type A POSS nanoparticle dispersion and the curing accelerator solution are mixed at a volume ratio of 10:1 and immediately sprayed onto the surface of the semi-cured base coat, with a thickness of 75 μm; after an interval of 2 minutes, the type B POSS nanoparticle dispersion is directly sprayed onto the upper layer, with a thickness of 16 μm; (4) After the spraying is completed, the aluminum alloy plate is cured at 90°C for 2 hours, and then cured at 130°C for 1 hour to obtain the super double hydrophobic coating aluminum alloy plate.

[0044] Example 4: Preparation of type A POSS nanoparticles: 100 mL of anhydrous ethanol and 20 mL of deionized water were added to a dry 250 mL three-necked flask. Under nitrogen protection and ice-water bath cooling, 5.0 g of tridecafluorooctyltrimethoxysilane, 1.2 g of silane coupling agent KH792, and 0.8 g of tetraethyl orthosilicate were slowly added dropwise. The entire addition process was completed within 30 minutes, and the system temperature was maintained below 10 °C. After the addition was complete, 0.1 mol / L hydrochloric acid aqueous solution was added to adjust the pH of the reaction system to 4. The ice bath was removed, and the reaction mixture was heated to 80 °C and refluxed for 24 hours under nitrogen protection and magnetic stirring. After the reaction was completed, the mixture was cooled to room temperature and transferred to a rotary evaporator. Most of the ethanol and water were removed by vacuum distillation at 60 °C. The obtained viscous substance was dissolved in 50 mL of tetrahydrofuran, and then added dropwise to 500 mL of n-hexane under vigorous stirring, resulting in a white precipitate. After standing and filtration, the obtained solid was washed three times with n-hexane. The product was then placed in a vacuum drying oven and dried at 75 °C for 12 hours to obtain white powdery type A POSS nanoparticles. The type A POSS nanoparticles were ultrasonically dispersed in hexafluoroxylene at a concentration of 4 wt% to obtain a type A POSS nanoparticle dispersion.

[0045] Preparation of type B POSS nanoparticles: 100 mL of anhydrous ethanol and 20 mL of deionized water were added to a dry 250 mL three-necked flask. Under nitrogen protection and cooling in an ice-water bath, 5.0 g of perfluorooctyltriethoxysilane, 1.5 g of γ-glycidoxypropyltrimethoxysilane (KH560), and 0.5 g of tetraethyl orthosilicate were slowly added dropwise over 30 minutes, maintaining the system temperature below 10 °C. After the addition was complete, 0.1 mol / L hydrochloric acid aqueous solution was added to adjust the pH of the reaction system to 4. The ice bath was removed, and the reaction mixture was heated to 75 °C and refluxed for 24 hours under nitrogen protection and magnetic stirring. After the reaction was completed, the mixture was cooled to room temperature and transferred to a rotary evaporator. Most of the ethanol and water were removed by vacuum distillation at 45 °C. The obtained viscous substance was dissolved in 50 mL of tetrahydrofuran, and then added dropwise to 500 mL of n-hexane under vigorous stirring, resulting in a white precipitate. After standing and filtration, the obtained solid was washed three times with n-hexane. The product was then placed in a vacuum drying oven and dried at 70 °C for 12 hours to obtain white powdery type B POSS nanoparticles. The type B POSS nanoparticles were ultrasonically dispersed in hexafluoroxylene at a concentration of 5 wt% to obtain a type B POSS nanoparticle dispersion.

[0046] Preparation of coatings with long-lasting superhydrophobic and amphoteric properties: (1) Sand the aluminum alloy plate with sandpaper, and clean and dry it with acetone; (2) Weigh 100 parts of bisphenol A type epoxy resin E-51 and 50 parts of polyamide curing agent (650) by weight, add xylene and n-butanol mixed in a mass ratio of 4:1, stir at high speed to disperse evenly, and obtain a base coat with a solid content of about 60%, let it stand to defoam and set aside. (3) The base coat is uniformly sprayed onto the surface of the aluminum alloy plate by spraying, with a wet film thickness of about 130 μm; it is left to stand at room temperature (25℃) for 20 minutes. At this time, the base coat has partially cross-linked and the surface has lost its fluidity but has not been completely cured (semi-cured state); 2-ethyl-4-methylimidazolium is dissolved in isopropanol at a concentration of 1 wt% to obtain a curing accelerator solution. The type A POSS nanoparticle dispersion and the curing accelerator solution are mixed at a volume ratio of 10:1 and immediately sprayed onto the surface of the semi-cured base coat, with a thickness of 85 μm; after an interval of 2 minutes, the type B POSS nanoparticle dispersion is directly sprayed onto the upper layer, with a thickness of 15 μm; (4) After the coating is completed, the aluminum alloy plate is cured at 85°C for 2 hours, and then cured at 125°C for 1 hour to obtain the super double hydrophobic coating aluminum alloy plate.

[0047] Example 5: Preparation of type A POSS nanoparticles: 100 mL of anhydrous ethanol and 20 mL of deionized water were added to a dry 250 mL three-necked flask. Under nitrogen protection and cooling in an ice-water bath, 5.0 g of perfluorooctyltriethoxysilane, 1.2 g of γ-aminopropyltriethoxysilane (KH550), and 0.8 g of tetraethyl orthosilicate were slowly added dropwise over 30 minutes, maintaining the system temperature below 10 °C. After the addition was complete, 0.1 mol / L hydrochloric acid aqueous solution was added to adjust the pH of the reaction system to 5. The ice bath was removed, and the reaction mixture was heated to 65 °C and refluxed for 24 hours under nitrogen protection and magnetic stirring. After the reaction was completed, the mixture was cooled to room temperature and transferred to a rotary evaporator. Most of the ethanol and water were removed by vacuum distillation at 60 °C. The obtained viscous substance was dissolved in 50 mL of tetrahydrofuran, and then added dropwise to 500 mL of n-hexane under vigorous stirring, resulting in a white precipitate. After standing and filtration, the obtained solid was washed three times with n-hexane. The product was then placed in a vacuum drying oven and dried at 70 °C for 12 hours to obtain white powdery type A POSS nanoparticles. The type A POSS nanoparticles were ultrasonically dispersed in hexafluoroxylene at a concentration of 3 wt% to obtain a type A POSS nanoparticle dispersion.

[0048] Preparation of type B POSS nanoparticles: 100 mL of anhydrous ethanol and 20 mL of deionized water were added to a dry 250 mL three-necked flask. Under nitrogen protection and ice-water bath cooling, 5.0 g of trifluoropropyltrimethoxysilane, 1.5 g of γ-glycidoxypropyltrimethoxysilane (KH560), and 0.5 g of tetraethyl orthosilicate were slowly added dropwise over 30 minutes, maintaining the system temperature below 10 °C. After the addition was complete, 0.1 mol / L hydrochloric acid aqueous solution was added to adjust the pH of the reaction system to 4. The ice bath was removed, and the reaction mixture was heated to 75 °C and refluxed for 24 hours under nitrogen protection and magnetic stirring. After the reaction was completed, the mixture was cooled to room temperature and transferred to a rotary evaporator. Most of the ethanol and water were removed by vacuum distillation at 55 °C. The obtained viscous substance was dissolved in 50 mL of tetrahydrofuran, and then added dropwise to 500 mL of n-hexane under vigorous stirring, resulting in a white precipitate. After standing and filtration, the obtained solid was washed three times with n-hexane. The product was then placed in a vacuum drying oven and dried at 75 °C for 12 hours to obtain white powdery type B POSS nanoparticles. The type B POSS nanoparticles were ultrasonically dispersed in hexafluoroxylene at a concentration of 4 wt% to obtain a type B POSS nanoparticle dispersion.

[0049] Preparation of coatings with long-lasting superhydrophobic and amphoteric properties: (1) Sand the aluminum alloy plate with sandpaper, and clean and dry it with acetone; (2) Weigh 120 parts of bisphenol A type epoxy resin E-51 and 50 parts of polyetheramine curing agent (D230) by weight, add xylene and n-butanol mixed solution at a mass ratio of 4:1, stir at high speed to disperse evenly, and obtain a base coat with a solid content of about 60%, let stand to defoam and set aside. (3) The base coat is uniformly sprayed onto the surface of the aluminum alloy plate by spraying, with a wet film thickness of about 135 μm; it is left to stand at room temperature (25℃) for 20 minutes. At this time, the base coat has partially cross-linked and the surface has lost its fluidity but has not been completely cured (semi-cured state); 2-ethyl-4-methylimidazole is dissolved in isopropanol at a concentration of 1 wt% to obtain a curing accelerator solution. The type A POSS nanoparticle dispersion and the curing accelerator solution are mixed at a volume ratio of 10:1 and immediately sprayed onto the surface of the semi-cured base coat with a thickness of 70 μm; after an interval of 2 minutes, the type B POSS nanoparticle dispersion is directly sprayed onto the upper layer with a thickness of 20 μm. (4) After the spraying is completed, the aluminum alloy plate is cured at 75°C for 2 hours, and then cured at 140°C for 1 hour to obtain the super double hydrophobic coating aluminum alloy plate.

[0050] Comparative Example 1: Preparation of modified silica microspheres: 10 g of hydrophobic silica nanospheres with an average particle size of 50 nm were dispersed in 200 mL of anhydrous toluene. 2 g of perfluorooctyltriethoxysilane and 1 g of KH550 were added. The mixture was refluxed at 80 °C for 12 hours under nitrogen protection. After the reaction, the mixture was centrifuged, washed three times with ethanol, and dried. The resulting modified silica nanospheres were dispersed in hexafluoroxylene at a concentration of 5 wt% and ultrasonically dispersed to obtain a modified silica nanosphere dispersion.

[0051] (1) Sand the aluminum alloy plate with sandpaper, and clean and dry it with acetone; (2) Weigh 100 parts of bisphenol A type epoxy resin E-51 and 50 parts of polyamide curing agent (650) by weight, add xylene and n-butanol mixed in a mass ratio of 4:1, stir at high speed to disperse evenly, and obtain a base coat with a solid content of about 60%, let it stand to defoam and set aside. (3) The base coating is uniformly sprayed onto the surface of the aluminum alloy plate by spraying, with a wet film thickness of about 50 μm; it is left to stand at room temperature (25℃) for 20 minutes. At this time, the base coating has partially cross-linked and the surface has lost its fluidity but has not been completely cured (semi-cured state); 2-ethyl-4-methylimidazole is dissolved in isopropanol at a concentration of 1 wt% to obtain a curing accelerator solution. The modified silica nanosphere dispersion and the curing accelerator solution are mixed at a volume ratio of 10:1 and then immediately sprayed onto the surface of the semi-cured base coating. (4) After the spraying is completed, the aluminum alloy plate is cured at 80°C for 2 hours, and then cured at 150°C for 1 hour to obtain the super double hydrophobic coating aluminum alloy plate.

[0052] Table 1 shows the water contact angle, oil contact angle, and water contact angle after 30 days of outdoor placement of the coatings prepared in Examples 1-5 and Comparative Example 1.

[0053] Table 1: Water contact angle and oil contact angle data of the coatings obtained in Examples 1-5 and Comparative Example 1 ; As can be seen from the data in Table 1, compared with the coating prepared by modified silica microspheres in Comparative Example 1, the coatings prepared by Examples 1-5 of this application and Comparative Example 1 all exhibit superhydrophobic and oleophobic properties in the initial state. However, after being placed outdoors for 30 days, the coating prepared by this application still maintains superhydrophobic and oleophobic properties, while the coating prepared by Comparative Example 1 does not have superhydrophobic and oleophobic properties. The inventors analyzed that this is because the stable nano-rough structure constructed by the two types of POSS particles can effectively resist physical damage, so that the hydrophobic and oleophobic properties of the coating can be maintained for a long time under harsh environments.

[0054] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0055] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. In this application, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly specified.

[0056] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A coating with long-lasting superhydrophobic and dihydrophobic properties, characterized in that, The coating includes a base coat and a top coat. The base coat includes an epoxy resin and an amine curing agent. The top coat includes type A POSS nanoparticles and type B POSS nanoparticles. The type A POSS nanoparticles are obtained by reacting fluorosiloxanes, aminosilane coupling agents, and tetraethyl orthosilicate. The type B POSS nanoparticles are obtained by reacting fluorosiloxanes, epoxysilane coupling agents, and tetraethyl orthosilicate.

2. The coating with long-lasting superhydrophobic properties according to claim 1, characterized in that, The mass ratio of epoxy resin to amine curing agent is 2-3:

1.

3. The coating with long-lasting superhydrophobic and amphoteric properties according to claim 1, characterized in that, The epoxy resin is selected from any one of bisphenol A type epoxy resin E-51, E-44, bisphenol F type epoxy resin F51, F-44; the amine curing agent is selected from polyamide curing agent and polyether amine curing agent.

4. The coating with long-lasting superhydrophobic properties according to claim 1, characterized in that, The fluorinated siloxane is selected from any one of perfluorooctyltriethoxysilane, trifluoropropyltrimethoxysilane, heptadecafluorodecyltrimethoxysilane, and tridecafluorooctyltrimethoxysilane; the aminosilane coupling agent is selected from any one of KH550 and KH792; and the epoxysilane coupling agent is selected from any one of KH560, KH561, and KH562.

5. A method for preparing a coating using the coating material with long-lasting superhydrophobic properties as described in any one of claims 1-4, characterized in that, Includes the following steps: S101, Surface treatment of the substrate; S102, weigh out epoxy resin and amine curing agent, add mixed solvent, stir and disperse evenly to obtain the base coat, spray the base coat onto the surface of the substrate by spraying, and let it stand at room temperature; S103, when the base coat is in a semi-cured state, mix the type A POSS nanoparticle dispersion with the curing accelerator solution and spray it onto the surface of the base coat. Then spray the type B POSS nanoparticle dispersion onto the surface of the type A POSS nanoparticle dispersion. S104, after spraying and curing, yields a coating with long-lasting superhydrophobic and dihydrophobic properties.

6. The method for preparing the coating according to claim 5, characterized in that, The mixed solvent is a solution of xylene and n-butanol mixed in a mass ratio of 3-5:

1.

7. The method for preparing the coating according to claim 5, characterized in that, The type A POSS nanoparticles were prepared by the following process: fluorosiloxane, aminosilane coupling agent, and tetraethyl orthosilicate were added to a mixed solution of anhydrous ethanol and deionized water. Hydrochloric acid was added to adjust the pH of the system to 4-5. The reaction was heated, and after the reaction was completed, the mixture was cooled to room temperature and distilled. The resulting product was dissolved in tetrahydrofuran, then added to n-hexane, allowed to stand, filtered, washed, and dried to obtain type A POSS nanoparticles. The type A POSS nanoparticles were ultrasonically dispersed in hexafluoroxylene at a concentration of 2wt%-5wt% to obtain a type A POSS nanoparticle dispersion.

8. The method for preparing the coating according to claim 5, characterized in that, The type B POSS nanoparticles were prepared by the following process: fluorosiloxane, epoxy silane coupling agent, and tetraethyl orthosilicate were added to a mixed solution of anhydrous ethanol and deionized water. Hydrochloric acid was added to adjust the pH of the system to 4-5. The reaction was heated, and after the reaction was completed, the mixture was cooled to room temperature and distilled. The resulting product was dissolved in tetrahydrofuran, then added to n-hexane, allowed to stand, filtered, washed, and dried to obtain type B POSS nanoparticles. The type B POSS nanoparticles were ultrasonically dispersed in hexafluoroxylene at a concentration of 2wt%-5wt% to obtain a type B POSS nanoparticle dispersion.

9. The method for preparing the coating according to claim 5, characterized in that, The curing accelerator solution is obtained by dissolving 2-ethyl-4-methylimidazol in isopropanol at a concentration of 1wt%-3wt%.

10. A coating with long-lasting superhydrophobic properties, characterized in that, It is prepared by the preparation method according to any one of claims 5-9.

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