A super-amphiphobic coating finish, coating and method of making the same

Abstract

The application relates to the technical field of coatings, in particular to a super-biporous coating finish, a coating and a preparation method thereof. The super-biporous coating finish provided by the application is a modified nanoparticle dispersion liquid with a solid content of 5-15%, wherein the modified nanoparticles are obtained by modifying nanoparticles with fluorosiloxane and azo epoxy siloxane. The application forms the finish by treating the nanoparticles with a treating agent containing an epoxy group and an amino group, the treated nanoparticles can react with a curing agent and a resin group in a base material, the chemical bond energy formed is much greater than that of a hydrogen bond, and the combination stability of the coating and the base material is effectively improved.

Description

Technical Field

[0001] This application relates to the field of coating technology, and in particular to a superhydrophobic coating topcoat, coating layer and preparation method thereof. Background Technology

[0002] Superhydrophobic self-cleaning coatings, based on the lotus effect and featuring micro-nano rough structures and low surface energy modification layers, can achieve highly efficient repulsion of aqueous media and contaminants. They have demonstrated irreplaceable application value in fields such as flashover prevention in power equipment, corrosion protection in chemical equipment, and self-cleaning of building exteriors, and have become a research hotspot in materials science and engineering. However, this technology still faces core bottlenecks in practical industrialization, such as insufficient durability and limited functionality, which greatly restricts its large-scale engineering application. Insufficient durability is the primary bottleneck restricting the engineering application of superhydrophobic coatings. The core issue lies in mechanical fragility – essentially the lack of mechanical stability in the micro / nano rough structure and the insufficient chemical durability of the low surface energy modification layer. The core functional unit of superhydrophobic coatings is the "micro / nano protrusion array." Due to its large aspect ratio and weak interfacial bonding with the substrate, this structure is highly susceptible to structural fracture, detachment, or collapse under the mechanical forces of friction and scratching during actual service. Experimental data shows that after 200 standard friction cycles (500g load, cotton cloth grinding head), coatings prepared by traditional spraying processes generally experience a sharp drop in water contact angle (WCA) from over 155° to below 130°, and a roll-off angle (SA) exceeding 30°, completely losing their core superhydrophobic function and failing to meet the basic service life requirements for engineering applications.

[0003] Patent CN115725223B discloses an anti-icing hydrophobic coating and its application, as well as a method for preparing the anti-icing hydrophobic coating. This patent uses a mixture of silane coupling agent modified SiO2 and silane coupling agent modified SiC particles with different particle sizes as a topcoat, which increases the internal stability of the anti-icing hydrophobic coating system. However, the modified SiC particles have a large particle size, which can easily lead to uneven spraying.

[0004] Therefore, it is essential to provide a superhydrophobic coating topcoat that can improve the weather resistance and uniform spraying of the coating. Summary of the Invention

[0005] This application provides a super-hydrophobic coating topcoat to solve the problems of insufficient weather resistance and uneven spraying of super-hydrophobic coatings in related technologies.

[0006] In a first aspect, this application provides a superhydrophobic coating topcoat, wherein the topcoat is a modified nanoparticle dispersion with a solid content of 5-15%, and the modified nanoparticles are obtained by modifying nanoparticles with fluorinated siloxanes and azoepoxy siloxanes.

[0007] In some embodiments, the nanoparticles are any one of nano-silica, nano-titanium dioxide, nano-calcium carbonate, and nano-alumina.

[0008] In some embodiments, the nanoparticles are a mixture of three nanoparticles with different particle sizes.

[0009] In some preferred embodiments, the nanoparticles are a mixture of small-diameter nanoparticles (20-30 nm), medium-diameter nanoparticles (45-55 nm), and large-diameter nanoparticles (90-100 nm) in a mass ratio of 5-10:60-80:15-30. The amount of medium-diameter nanoparticles used is greater than the sum of the masses of the small-diameter and large-diameter nanoparticles. The small-diameter nanoparticles can fill the gaps between the medium-diameter and large-diameter nanoparticles, ensuring the uniformity of nanoparticle distribution.

[0010] In some embodiments, the solvent used in the modified nanoparticle dispersion is a mixture of two or more of methanol, ethanol, acetone, butanone, and water.

[0011] In some embodiments, the fluorinated siloxane is any one of perfluorodecyltrimethoxysilane, perfluorodecyltriethoxysilane, perfluorooctyltrimethoxysilane, tridecafluorooctyltriethoxysilane, and perfluorooctylsulfonylpropyltriethoxysilane.

[0012] In some embodiments, the azoepoxysiloxane is obtained by reacting 4-aminoazobenzene and 3-glycidyl etheroxypropyltriethoxysilane.

[0013] In some embodiments, the molar ratio of fluorosiloxane to azoepoxysiloxane is 1:1.2-2.

[0014] Secondly, this application also provides a method for preparing the above-mentioned superhydrophobic coating topcoat, comprising the following steps: Step S101: Disperse the fluorosiloxane in a solvent, and add a small amount of alkaline aqueous solution while stirring at a speed of 300-500 rpm to adjust the pH of the system to between 8 and 9. Step S102: Adjust the speed of the disperser to 500-800 rpm, slowly add azoepoxysiloxane to the fluorinated siloxane solution while stirring, slowly raise the water bath temperature to 55-65°C, cool after the reaction is complete, and obtain the treated fluorinated siloxane. Step S103: Add nanoparticles to solvent in proportion, adjust the speed of disperser to 500-800 rpm, disperse evenly, and then perform ultrasonic treatment to obtain nanoparticle dispersion. In step S104, the treated fluorinated siloxane is slowly added dropwise to the nanoparticle dispersion while stirring at a speed of 1000-1200 rpm. After mixing evenly, the water bath temperature is slowly raised to 65-75°C. After the reaction is completed, the mixture is ultrasonically treated and then placed in a water bath at 65-75°C for further reaction. After cooling to room temperature and aging, the superhydrophobic topcoat is obtained.

[0015] In some embodiments, azoepoxysiloxane is prepared by the following process: 4-aminoazobenzene is mixed with anhydrous ethanol, triethylamine is added, and then 3-glycidyl etheroxypropyltriethoxysilane is slowly added. The mixture is heated in a water bath to 55-65°C. After the reaction is completed, the mixture is cooled and filtered to obtain azoepoxysiloxane.

[0016] In some embodiments, the mass ratio of 4-aminoazobenzene to 3-glycidyl etheroxypropyltriethoxysilane is 1:1.6-1.8; the amount of triethylamine added is 5%-15% of the mass of 4-aminoazobenzene; and the amount of anhydrous ethanol added is 5-10 times the mass of 4-aminoazobenzene.

[0017] Thirdly, this application also provides a method for preparing an ultra-hydrophobic coating using the above-mentioned ultra-hydrophobic coating topcoat, specifically by spraying the ultra-hydrophobic coating topcoat onto the surface of a substrate and curing it to obtain the ultra-hydrophobic coating.

[0018] In some embodiments, the substrate is a polyurethane coating, epoxy resin coating, acrylic resin coating, or fluorocarbon coating formed by mixing any one of polyurethane, epoxy resin, acrylic resin, or fluorocarbon coating with a curing agent; the curing agent is a polyamide curing agent.

[0019] The beneficial effects of the technical solution provided in this application include: (1) Improve the adhesion between the substrate and the surface: This application uses a treatment agent containing epoxy and amino groups to treat nanoparticles to form a topcoat. The treated nanoparticles can react with the curing agent and resin groups in the substrate, and the chemical bond energy formed is much greater than that of hydrogen bonds, which effectively improves the bonding stability between the coating and the substrate. (2) Enhanced weather resistance and durability: After UV aging test and salt spray test, the coating obtained in this application embodiment did not peel off, wrinkle, blister, or discolor after 1500h. After 1kg load and 1000r friction, the water contact angle still reached 105°, showing excellent weather resistance and wear resistance. (3) The water contact angle of the coating obtained in this application is 165° and the oil contact angle is 159°, maintaining the high efficiency of superhydrophobic properties. Attached Figure Description

[0020] 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.

[0021] Figure 1 This is a schematic diagram of the water contact angle of the super-bihydrophobic coating in Example 1; Figure 2 This is a schematic diagram of the oil contact angle of the superhydrophobic coating in Example 1. Detailed Implementation

[0022] 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.

[0023] This application provides a superhydrophobic coating that solves the problem of insufficient weather resistance in existing superhydrophobic coatings.

[0024] Example 1: Preparation of azoepoxysiloxane: By mass, 10 parts of 4-aminoazobenzene and 60 parts of anhydrous ethanol are mixed, 0.6 parts of triethylamine are added, and then 16 parts of 3-glycidyl etheroxypropyltriethoxysilane are slowly added. The mixture is heated in a water bath to 60°C. After the reaction is completed, the mixture is cooled and filtered to obtain azoepoxysiloxane.

[0025] Preparation of superhydrophobic coating topcoat: (1) Disperse 10 parts of perfluorodecyltrimethoxysilane in 100 parts of ethanol solvent by mass, and add 1% sodium hydroxide aqueous solution while stirring at 300 rpm to adjust the pH value to 8. (2) According to the mass fraction, adjust the speed of the disperser to 600 rpm, and slowly add 9 parts of azoepoxysiloxane to the perfluorodecyltrimethoxysilane solution while stirring. Slowly raise the water bath temperature to 65°C, react for 4 hours and then cool to obtain the treated fluorinated siloxane. (3) By mass, 0.7 parts of silica powder with a particle size of 20-30 nm, 4.9 parts of silica powder with a particle size of 45-55 nm, and 1.4 parts of silica powder with a particle size of 90-100 nm were added to a mixed solvent of 70 parts of ethanol and 30 parts of acetone. The speed of the disperser was adjusted to 600 rpm. After the dispersion was uniform, the dispersion was ultrasonically treated for 1 h to obtain a silica dispersion. (4) Control the rotation speed to 1000 rpm, and slowly add 10 parts of the treated fluorinated siloxane to the silica dispersion while stirring. After mixing evenly, slowly raise the water bath temperature to 65°C. After reacting for 2 hours, perform ultrasonic treatment for 1 hour, and continue to react in a 65°C water bath for 16 hours. Then cool to room temperature and age for 48 hours to obtain the super hydrophobic topcoat.

[0026] Preparation of superhydrophobic coating: The superhydrophobic topcoat was sprayed onto the surface of a 100-micron thick polyurethane coating and dried at 25°C for 72 hours to obtain the superhydrophobic coating sample.

[0027] Figure 1 , Figure 2 These are schematic diagrams showing the water contact angle and oil contact angle of the super-bihydrophobic coating in Example 1.

[0028] Example 2: Preparation of azoepoxysiloxane: By mass, 10 parts of 4-aminoazobenzene and 65 parts of anhydrous ethanol are mixed, 1 part of triethylamine is added, and then 18 parts of 3-glycidyl etheroxypropyltriethoxysilane are slowly added. The mixture is heated in a water bath to 60°C. After the reaction is completed, the mixture is cooled and filtered to obtain azoepoxysiloxane.

[0029] Preparation of superhydrophobic coating topcoat: (1) Disperse 10 parts of perfluorodecyltrimethoxysilane in 100 parts of ethanol solvent by mass, and add 1% sodium hydroxide aqueous solution while stirring at 500 rpm to adjust the pH value to 9. (2) By mass, adjust the speed of the disperser to 800 rpm, and slowly add 12 parts of azoepoxysiloxane to the perfluorodecyltrimethoxysilane solution while stirring. Slowly raise the water bath temperature to 60°C, react for 4 hours and then cool to obtain the treated fluorinated siloxane. (3) By mass, 0.6 parts of silica powder with a particle size of 20-30 nm, 6.5 parts of silica powder with a particle size of 45-55 nm, and 2.0 parts of silica powder with a particle size of 90-100 nm were added to a mixed solvent of 70 parts of ethanol and 30 parts of acetone. The speed of the disperser was adjusted to 600 rpm. After the dispersion was uniform, the dispersion was ultrasonically treated for 1 h to obtain a silica dispersion. (4) Control the rotation speed to 1200 rpm, and slowly add 10 parts of the treated fluorinated siloxane to the silica dispersion while stirring. After mixing evenly, slowly raise the water bath temperature to 70°C. After reacting for 2 hours, perform ultrasonic treatment for 1 hour, and continue to react in a 70°C water bath for 16 hours. Then cool to room temperature and age for 48 hours to obtain the super hydrophobic topcoat.

[0030] Preparation of superhydrophobic coating: The superhydrophobic topcoat was sprayed onto the surface of the surface-dried epoxy resin coating and dried at 25°C for 72 hours to obtain the superhydrophobic coating sample.

[0031] Example 3: Preparation of azoepoxysiloxane: By mass, 10 parts of 4-aminoazobenzene and 80 parts of anhydrous ethanol are mixed, 0.8 parts of triethylamine are added, and then 16 parts of 3-glycidyl etheroxypropyltriethoxysilane are slowly added. The mixture is heated in a water bath to 55°C. After the reaction is completed, the mixture is cooled and filtered to obtain azoepoxysiloxane.

[0032] Preparation of superhydrophobic coating topcoat: (1) Disperse 10 parts of perfluorodecyltriethoxysilane in 100 parts of ethanol solvent by mass, and add 1% sodium hydroxide aqueous solution while stirring at 300 rpm to adjust the pH value to 8. (2) According to the mass fraction, adjust the speed of the disperser to 600 rpm, and slowly add 10 parts of azoepoxysiloxane to the perfluorodecyltriethoxysilane solution while stirring. Slowly raise the water bath temperature to 65°C, react for 4 hours and then cool to obtain the treated fluorinated siloxane. (3) By mass, 0.8 parts of alumina powder with a particle size of 20-30 nm, 7.5 parts of alumina powder with a particle size of 45-55 nm, and 2.5 parts of alumina powder with a particle size of 90-100 nm were added to a mixed solvent of 70 parts of ethanol and 30 parts of acetone. The speed of the disperser was adjusted to 800 rpm. After the powder was dispersed evenly, it was ultrasonically treated for 1 h to obtain an alumina dispersion. (4) Control the rotation speed to 1000 rpm, and slowly add 10 parts of the treated fluorinated siloxane to the alumina dispersion while stirring. After mixing evenly, slowly raise the water bath temperature to 65°C. After reacting for 2 hours, perform ultrasonic treatment for 1 hour, continue to react in a 65°C water bath for 16 hours, then cool to room temperature and age for 48 hours to obtain the super hydrophobic topcoat.

[0033] Preparation of superhydrophobic coating: The superhydrophobic topcoat was sprayed onto the surface of the 100-micron thick fluorocarbon coating and dried at 25°C for 72 hours to obtain the superhydrophobic coating sample.

[0034] Example 4: Preparation of azoepoxysiloxane: By mass, 10 parts of 4-aminoazobenzene and 70 parts of anhydrous ethanol are mixed, 1.2 parts of triethylamine are added, and then 18 parts of 3-glycidyl etheroxypropyltriethoxysilane are slowly added. The mixture is heated in a water bath to 65°C. After the reaction is completed, the mixture is cooled and filtered to obtain azoepoxysiloxane.

[0035] Preparation of superhydrophobic coating topcoat: (1) Disperse 10 parts of tridecylfluorooctyltriethoxysilane in 100 parts of ethanol solvent by mass, and add 1% sodium hydroxide aqueous solution while stirring at 500 rpm to adjust the pH value to 8. (2) According to the mass fraction, adjust the speed of the disperser to 600 rpm, and slowly add 12 parts of azoepoxysiloxane to the tridecylfluorooctyltriethoxysilane solution while stirring. Slowly raise the water bath temperature to 65°C, react for 4 hours and then cool to obtain the treated fluorinated siloxane. (3) According to the mass fraction, 0.6 parts of calcium carbonate powder with a particle size of 20-30 nm, 7.0 parts of calcium carbonate powder with a particle size of 45-55 nm, and 2.0 parts of calcium carbonate powder with a particle size of 90-100 nm were added to a mixed solvent of 70 parts of ethanol and 30 parts of acetone. The speed of the disperser was adjusted to 600 rpm. After the dispersion was uniform, the mixture was ultrasonically treated for 1 h to obtain a calcium carbonate dispersion. (4) Control the rotation speed to 1200 rpm, and slowly add 10 parts of the treated fluorinated siloxane to the calcium carbonate dispersion while stirring. After mixing evenly, slowly raise the water bath temperature to 65°C. After reacting for 2 hours, perform ultrasonic treatment for 1 hour, and continue to react in a 65°C water bath for 16 hours. Then cool to room temperature and age for 48 hours to obtain the super hydrophobic topcoat.

[0036] Preparation of superhydrophobic coating: The superhydrophobic topcoat was sprayed onto the surface of a 100-micron thick polyurethane coating and dried at 25°C for 72 hours to obtain the superhydrophobic coating sample.

[0037] Example 5: Preparation of azoepoxysiloxane: By mass, 10 parts of 4-aminoazobenzene and 75 parts of anhydrous ethanol are mixed, 1.5 parts of triethylamine are added, and then 16 parts of 3-glycidyl etheroxypropyltriethoxysilane are slowly added. The mixture is heated in a water bath to 60°C. After the reaction is completed, the mixture is cooled and filtered to obtain azoepoxysiloxane.

[0038] Preparation of superhydrophobic coating topcoat: (1) Disperse 10 parts of perfluorodecyltrimethoxysilane in 100 parts of ethanol solvent by mass, and add 1% sodium hydroxide aqueous solution while stirring at 400 rpm to adjust the pH value to 9. (2) By mass, adjust the speed of the disperser to 800 rpm, and slowly add 13 parts of azoepoxysiloxane to the perfluorodecyltrimethoxysilane solution while stirring. Slowly raise the water bath temperature to 60°C, react for 4 hours and then cool to obtain the treated fluorinated siloxane. (3) According to the mass fraction, 0.9 parts of silica powder with a particle size of 20-30 nm, 7.5 parts of silica powder with a particle size of 45-55 nm, and 2.2 parts of silica powder with a particle size of 90-100 nm were added to a mixed solvent of 70 parts of ethanol and 30 parts of acetone. The speed of the disperser was adjusted to 800 rpm. After the dispersion was uniform, the dispersion was ultrasonically treated for 1 h to obtain silica dispersion. (4) Control the rotation speed to 1000 rpm, and slowly add 10 parts of the treated fluorinated siloxane to the silica dispersion while stirring. After mixing evenly, slowly raise the water bath temperature to 75°C. After reacting for 2 hours, perform ultrasonic treatment for 1 hour, and continue to react in a 75°C water bath for 16 hours. Then cool to room temperature and age for 48 hours to obtain the super hydrophobic topcoat.

[0039] Preparation of superhydrophobic coating: The superhydrophobic topcoat was sprayed onto the surface of a 100-micron thick hydroxyl acrylic resin coating that had been surface-dried, and dried at 25°C for 72 hours to obtain the superhydrophobic coating sample.

[0040] Comparative Example 1: The only difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not use azoepoxysiloxane to treat perfluorodecyltrimethoxysilane; the rest of the process is basically the same as that of Example 1.

[0041] Comparative Example 2: Preparation of azoepoxysiloxane: Same as in Example 1.

[0042] Preparation of superhydrophobic coating topcoat: By mass, 4.9 parts of silica powder with a particle size of 20-30 nm, 4.9 parts with a particle size of 45-55 nm, and 1.4 parts with a particle size of 90-100 nm were added to a mixed solvent of 70 parts ethanol and 30 parts acetone. The speed of the disperser was adjusted to 600 rpm. After uniform dispersion, the mixture was ultrasonically treated for 1 hour to obtain a silica dispersion. 10 parts of perfluorodecyltrimethoxysilane and 5 parts of azoepoxysiloxane were added to the silica dispersion and mixed evenly. The water bath temperature was slowly raised to 65°C and reacted for 2 hours. After ultrasonic treatment for 1 hour, the mixture was placed in a 65°C water bath for another 16 hours. After cooling to room temperature, the mixture was aged for 48 hours to obtain the superhydrophobic topcoat.

[0043] Preparation of superhydrophobic coating: The superhydrophobic topcoat was sprayed onto the surface of a 100-micron thick polyurethane coating and dried at 25°C for 72 hours to obtain the superhydrophobic coating sample.

[0044] The performance of the superhydrophobic coatings of Examples 1-5 and Comparative Examples 1-2 were tested, and the test results are shown in Table 1.

[0045] The test methods are described in Table 1: Abrasion resistance: according to GB / T 1768-2006, 1kg, 1000r; Adhesion: in accordance with GB / T 1720-1979; Water resistance: Immersed in water for 240 hours; Chemical resistance: Immerse in acid, alkali, and salt reagents (3% concentration) at 25℃ for 24 hours respectively; Oil resistance: Immersed in transformer oil at 100℃; UV aging resistance test: in accordance with GB / T 23987-2009; Salt spray resistance: GB / T 1771-2007, 1000h.

[0046] Table 1: Performance test results of the superhydrophobic coatings in Examples 1-5 and Comparative Examples 1-2 ; As shown in Table 1, the coating obtained in Comparative Example 1 without the use of azoepoxysiloxane to treat perfluorodecyltrimethoxysilane exhibits poor abrasion resistance, oil resistance fails after 48 hours, and fails the UV aging test and salt spray test after 1500 hours. The applicant analyzes that this is because the topcoat prepared using perfluorodecyltrimethoxysilane-modified nano-silica powder, when sprayed onto the primer coating surface, only bonds with the primer through physical intercalation and hydrogen bonding, resulting in weak interfacial forces and relatively low adhesion between the topcoat and primer. In contrast, the topcoat prepared using azoepoxysiloxane modification allows the nitrogen-nitrogen double bonds in its molecules to break and generate amino groups during film formation. These amino groups can chemically react with the curing agent in the primer system, forming stable covalent bonds at the interface, thus significantly improving the interfacial bonding strength between the primer and topcoat.

[0047] Comparative Example 2 directly treated silica with a mixture of perfluorodecyltrimethoxysilane and azoepoxysiloxane. The resulting coating had poor oil resistance. The applicant analyzed that this was because when the nano-silica powder was modified using a mixture of two silane coupling agents, the two coupling agents would preferentially react with the silica surface, resulting in a decrease in the fluorine content on the silica particle surface. This, in turn, reduced the oil resistance of the topcoat and adversely affected the long-term outdoor self-cleaning performance of the coating.

[0048] 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.

[0049] 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.

[0050] 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 super-hydrophobic coating topcoat, characterized in that, The topcoat is a modified nanoparticle dispersion with a solid content of 5-15%, and the modified nanoparticles are obtained by modifying nanoparticles with fluorinated siloxanes and azoepoxy siloxanes.

2. The superhydrophobic coating topcoat according to claim 1, characterized in that, The nanoparticles are any one of nano-silica, nano-titanium dioxide, nano-calcium carbonate, and nano-alumina.

3. The super-hydrophobic coating topcoat according to claim 1, characterized in that, The nanoparticles are a mixture of three different sizes of nanoparticles.

4. The super-hydrophobic coating topcoat according to claim 1, characterized in that, The fluorinated siloxane is any one of perfluorodecyltrimethoxysilane, perfluorodecyltriethoxysilane, perfluorooctyltrimethoxysilane, tridecafluorooctyltriethoxysilane, and perfluorooctylsulfonylpropyltriethoxysilane.

5. The superhydrophobic coating topcoat according to claim 1, characterized in that, The azoepoxysiloxane is obtained by reacting 4-aminoazobenzene and 3-glycidyl etheroxypropyltriethoxysilane.

6. The method for preparing the superhydrophobic coating topcoat according to any one of claims 1-5, characterized in that, Includes the following steps: S101, Disperse the fluorosiloxane in a solvent, and add an alkaline aqueous solution while stirring at a speed of 300-500 rpm to adjust the pH of the system to between 8 and 9. S102, adjust the speed of the disperser to 500-800 rpm, add azocyclooxysiloxane to the fluorinated siloxane solution while stirring, heat to 55-65℃, cool after the reaction is completed to obtain the treated fluorinated siloxane; S103, add nanoparticles to solvent in proportion, adjust the speed of disperser to 500-800 rpm, disperse evenly, and then sonicate to obtain nanoparticle dispersion. S104, while stirring at 1000-1200 rpm, the treated fluorinated siloxane is added dropwise to the nanoparticle dispersion. After mixing evenly, the temperature is raised to 65-75℃. After the reaction is completed, the mixture is sonicated and the reaction continues at 65-75℃. Then, it is cooled to room temperature and aged to obtain the superhydrophobic coating topcoat.

7. The method for preparing the superhydrophobic coating topcoat according to claim 6, characterized in that, Azoepoxysiloxane is prepared by the following process: 4-aminoazobenzene is mixed with anhydrous ethanol, triethylamine is added, and then 3-glycidyl etheroxypropyltriethoxysilane is slowly added. The mixture is heated in a water bath to 55-65°C. After the reaction is completed, the mixture is cooled and filtered to obtain azoepoxysiloxane.

8. The method for preparing the superhydrophobic coating topcoat according to claim 7, characterized in that, The mass ratio of 4-aminoazobenzene to 3-glycidyl etheroxypropyltriethoxysilane is 1:1.6-1.8; the amount of triethylamine added is 5%-15% of the mass of 4-aminoazobenzene; and the amount of anhydrous ethanol added is 5-10 times the mass of 4-aminoazobenzene.

9. A method for preparing a super-hydrophobic coating using the super-hydrophobic coating topcoat according to any one of claims 6-8, characterized in that, The superhydrophobic coating is sprayed onto the surface of the substrate and cured to obtain the superhydrophobic coating layer.

10. A superhydrophobic coating, characterized in that, It was prepared using the preparation method described in claim 9.

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