A preparation method of a highly wear-resistant super-hydrophobic coating and coating

Abstract

The invention relates to a preparation method of a highly wear-resistant super-hydrophobic coating and the coating, the preparation method comprising the following steps: hydrophobic modification of SiO2 and glass fiber powder; mixing hydrophobic nano-spherical SiO2 particles, hydrophobic micron-spherical SiO2, hydrophobic glass fiber powder, epoxy resin and ethyl acetate to prepare a super-hydrophobic coating; sequentially cleaning a substrate with deionized water and anhydrous ethanol; hot-pressing a thermoplastic plastic screen onto the surface of the substrate; spraying the super-hydrophobic coating onto the treated substrate surface, and then using an electrostatic flocking device to adsorb the hydrophobic fiber composite powder onto the coating surface, and curing to prepare the coating; the super-hydrophobic coating prepared by the method has a microscopic morphology consisting of mesh ribs and a cured super-hydrophobic composite filled in the mesh structure, has excellent hydrophobic performance, outstanding wear resistance and low preparation cost.

Description

Technical Field

[0001] This application relates to the field of superhydrophobic coating preparation technology, specifically to a method for preparing a high wear-resistant superhydrophobic coating and the coating itself. Background Technology

[0002] Superhydrophobic coatings possess excellent water-repellent properties, making it difficult for water droplets to wet their surfaces. Surfaces with a contact angle greater than 150° and a roll-off angle less than 10° are generally defined as superhydrophobic surfaces. Due to their superior self-cleaning, anti-icing, anti-corrosion, and drag-reducing properties, superhydrophobic coatings have broad application prospects in areas such as metal corrosion protection, power system anti-icing and anti-fouling, and aircraft anti-icing.

[0003] Currently, spraying is a feasible method for mass-producing superhydrophobic coatings under practical conditions due to its advantages of simple process and low cost. However, poor wear resistance is the main problem restricting the mass production and use of superhydrophobic coatings. The reason why superhydrophobic coatings prepared by traditional spraying methods are prone to failure is that their rough surface structure is easily damaged. The coating system used consists of low surface energy fillers, film-forming substances, and solvents. The rough structure of the coating surface depends on the protrusions formed by the accumulation of filler particles and the pores formed by the rapid evaporation of solvents. Because the filler particles are modified with low surface energy, their bonding force with the film-forming substances is low. Therefore, the rough structure formed by the accumulation of filler particles is easily damaged, causing the coating to fail. Researchers have improved the wear resistance of superhydrophobic coatings from the perspective of optimizing coating formulations and constructing surface microstructures. Patent CN112210272B discloses "a wear-resistant superhydrophobic composite material and its preparation method". It prepares a superhydrophobic coating with micro / nano-scale surface structure by combining micron-sized particles with strong interparticle interactions and a stable structure composed of multi-level nanoparticles with an epoxy adhesive. This method improves the mechanical stability of the superhydrophobic coating to a certain extent. However, the preparation process of the terminal amino hyperbranched polysiloxane and ACNTB-SiO2-coupling agent particles used in the coating is complicated, the reaction conditions are demanding, and it is not easy to prepare in batches. In addition, the use of carbon nanotubes as one of the main fillers results in high cost and has limitations in practical use. Patent CN 115608586 B discloses "a simple and controllable method for preparing super-wear-resistant and superhydrophobic surfaces." This method first sprays a modifier of polydimethylsiloxane (PDMS) and vapor-phase hydrophobic SiO2 onto a metal substrate surface, then uses an infrared nanosecond laser to ablate the coating surface, obtaining a regular micron-scale rough structure. This method can produce superhydrophobic coatings with designable surface morphology, while also improving their mechanical stability. However, preparing superhydrophobic coatings using this method requires laser etching equipment, which is costly and has poor production efficiency, thus limiting its application in mass production and design.

[0004] Therefore, developing a method for preparing highly wear-resistant superhydrophobic coatings under the premise of low cost and easy construction is of great significance for the practical application of superhydrophobic coatings. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing a high wear-resistant superhydrophobic coating and the coating itself. The superhydrophobic coating obtained has the advantages of excellent hydrophobicity and wear resistance, which can solve the problems of poor wear resistance and easy failure of traditional superhydrophobic coatings under actual working conditions.

[0006] This application is achieved through the following technical solution:

[0007] First, this application provides a method for preparing a highly wear-resistant superhydrophobic coating, which includes the following steps:

[0008] (1) The SiO2 particles and glass fiber powder were subjected to hydrophobic modification treatment to obtain hydrophobic nano-spherical SiO2 particles, hydrophobic micro-spherical SiO2 particles and hydrophobic glass fibers for later use.

[0009] The aforementioned SiO2 particles include micron-sized spherical SiO2 particles and nano-sized spherical SiO2 particles, with particle sizes of 5-20 μm and 15-30 nm, respectively; the glass fiber has a single filament diameter of 11-17 μm and an aspect ratio of 20-50.

[0010] (2) Preparation of superhydrophobic coating: Epoxy resin, curing agent and ethyl acetate are mixed with hydrophobic nano-spherical SiO2, hydrophobic micro-spherical SiO2 and hydrophobic glass fiber powder at room temperature using a magnetic stirrer. The stirring speed is about 450 r / min and the stirring time is 1.5-3 h to obtain superhydrophobic coating for later use.

[0011] In the prepared superhydrophobic coating, the mass fraction of epoxy resin (E51) is 2.48-4.96%, the mass fraction of curing agent (T31) is 0.62-1.24%, the mass fraction of hydrophobic nano-spherical SiO2 particles is 1.25-2.05%, the mass fraction of hydrophobic micron-spherical SiO2 particles is 1.25-2.05%, the mass fraction of hydrophobic glass fiber is 0.20-1.2%, and the balance is ethyl acetate.

[0012] (3) Mix hydrophobic nano-spherical SiO2 particles, hydrophobic micron-spherical SiO2, and hydrophobic glass fibers evenly with a mechanical stirrer at a speed of 140-300 r / min and a stirring time of 15-25 min to obtain hydrophobic fiber composite powder for later use.

[0013] In the obtained hydrophobic fiber composite powder, the mass ratio of hydrophobic nanospheres, hydrophobic SiO2, hydrophobic micron spheres, and hydrophobic glass fibers is 10:6:1-1.5, respectively.

[0014] (4) Pretreatment of the substrate: The substrate surface is cleaned with deionized water and anhydrous ethanol in sequence, and then dried for later use.

[0015] (5) Coating preparation: First, a sieve with a pore size of 11-850μm is hot-pressed onto the substrate surface; then, the superhydrophobic coating obtained in step (2) is sprayed onto the substrate surface to form a superhydrophobic coating layer; then, within 10-15 minutes after spraying, the hydrophobic fiber composite powder prepared in step (3) is adsorbed onto the surface of the superhydrophobic coating layer using electrostatic flocking technology, and a high wear-resistant superhydrophobic coating is obtained after curing at 20-80℃ for 1.5-48 hours.

[0016] This coating material has a wide curing temperature range, making it suitable for a broad range of applications. Higher curing temperatures result in shorter curing times; lowering the curing temperature requires longer curing times, but the process can proceed naturally at room temperature without the need for external energy, which is more beneficial for engineering applications.

[0017] Furthermore, the preparation process of the "hydrophobic modification treatment" in step (1) above is as follows: 1) Anhydrous ethanol, 1H,1H,2H,2H perfluorodecyltriethoxysilane (fluorosilane) and ammonia (mass concentration 25%) are mixed in a mass ratio of 100:1-3:6 and ultrasonically dispersed for 15-30 min to obtain a modifier for later use; 2) Nano-spherical SiO2 particles, micron-sized spherical SiO2 and glass fiber are added to the above modifier respectively to obtain a mixture of nano-spherical SiO2 particles (where the mass percentage of nano-spherical SiO2 particles is 7.4%-10.7%) and a mixture of micron-sized spherical SiO2 particles (where the mass percentage of nano-spherical SiO2 particles is 7.4%-10.7%). The mixture consists of three solutions: a micron-sized spherical SiO2 particle (7.4%-10.7% by mass) and a glass fiber mixture (7.4%-10.7% by mass); 3) the three mixed solutions obtained in step 2) are placed in a heat-collecting magnetic stirrer and stirred continuously at a stirring speed of about 450 r / min at 20-40℃ for 8-14 h; then the resulting slurry is placed in an infrared drying oven and dried at 55-70℃ for 8-16 h, thus obtaining hydrophobic nano-spherical SiO2 particles, hydrophobic micron-sized spherical SiO2, and hydrophobic glass fiber powder, respectively. This step involves fluorination modification of the glass fiber and silica particles to reduce their surface energy and give them good hydrophobic properties.

[0018] Furthermore, the substrate material used in step (4) can be any material that can adhere to the screen (thermoplastic), such as plastic, glass, fiberglass or aluminum alloy.

[0019] Further, in step (5), "hot pressing" refers to: using a hot press to hot press the screen onto the substrate surface, forming a mesh-like rib structure on the substrate surface; the hot pressing temperature is 110-140℃, the hot pressing pressure is 3.5-5MPa, and the holding time is 15-30min; "spraying" refers to using a spray gun to spray the superhydrophobic coating obtained in step (2) onto the substrate surface, the spraying pressure is 4-6Bar, the distance between the spray gun and the substrate is 10cm, and the spray gun moving speed is 1.5cm / s; "electrostatic flocking" refers to using an electrostatic flocking machine to adsorb the hydrophobic fiber composite powder prepared in step (3) onto the above coating surface, the flocking voltage is 30-50KV, the powder output is about 3-5g / min, the electrostatic flocking machine moving speed is 2cm / s, and the distance between the electrostatic flocking machine outlet and the coating is 10-15cm. The obtained coating thickness is 70-100μm.

[0020] Secondly, this invention provides a highly wear-resistant superhydrophobic coating prepared by the above method. The coating consists of a sieve on the substrate surface and a cured superhydrophobic composite (including hydrophobic nanosphere SiO2, hydrophobic microsphere SiO2, randomly arranged hydrophobic glass fibers, epoxy resin, and hydrophobic glass fibers oriented perpendicular to the coating surface and implanted in the coating). The sieve is hot-pressed onto the substrate surface to form a grid-like rib structure, and the cured superhydrophobic composite fills the spaces between the grids.

[0021] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0022] 1. This application employs two different sizes of hydrophobic fillers: hydrophobic nano-spherical SiO2 particles and hydrophobic micron-sized spherical SiO2 particles. It also creatively introduces hydrophobic glass fibers into the superhydrophobic coating system to enhance the wear resistance of the superhydrophobic coating. Larger particle sizes result in a larger contact area with the matrix and a stronger bond with the cross-linked resin in the coating. Simultaneously, the glass fibers in the coating can transfer the load axially when their surface is subjected to wear. Therefore, the coating prepared using a filler system composed of hydrophobic nano-SiO2, hydrophobic micron-SiO2, and hydrophobic glass fibers exhibits excellent wear resistance.

[0023] 2. The preparation steps of the superhydrophobic coating in this application can be divided into three steps: hot-pressing the mesh, spraying the coating, and electrostatic adsorption. The mesh hot-pressed onto the substrate surface helps to enhance the bonding between the coating and the substrate. Its closed mesh structure helps to store gas to resist liquid wetting, which is beneficial to improving the hydrophobic performance of the coating. The superhydrophobic coating is sprayed. After spraying, the hydrophobic fiber composite powder composed of hydrophobic SiO2 and hydrophobic glass fiber is adsorbed onto the coating surface using electrostatic flocking technology. Under the action of electrostatic electric field, the glass fiber in the hydrophobic fiber composite powder will be arranged longitudinally along the direction of electric field and implanted into the coating perpendicular to the coating surface. After curing, the glass fiber is partially implanted into the coating. It is not easy to be pulled out or damaged during wear. The surface microstructure stability it forms is good, which improves the wear resistance of the superhydrophobic coating. At the same time, the hydrophobic filler layer formed on the coating surface can effectively ensure the hydrophobic performance of the coating and improve its wear resistance.

[0024] 3. The superhydrophobic coating prepared by this invention has excellent hydrophobic properties and outstanding wear resistance. The contact angle is >155° and the roll-off angle is <5°. The wear resistance of the coating is tested by a sandpaper cyclic wear test, and the coating can withstand ≥250 cycles of wear. At the same time, the superhydrophobic coating prepared by this invention is low in cost and simple in process, and is suitable for mass production. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the surface morphology of the superhydrophobic coating prepared in this invention.

[0026] In the figure, 1 is the superhydrophobic coating; 2 is the sieve; 3 is the matrix; 4 is the epoxy resin; 5 is the hydrophobic glass fiber; 6 is the hydrophobic micron-sized spherical SiO2 particles; and 7 is the hydrophobic nano-sized spherical SiO2 particles.

[0027] Figure 2 This is a SEM image of the surface morphology of the coating obtained in Example 2.

[0028] Figure 3 This is a photograph of the coating obtained in Example 3. Detailed Implementation

[0029] The fluorosilane (96%), ammonia (AR, 25%), SiO2 powders of different particle sizes, glass fiber powder, epoxy resin (E51), curing agent (T31), and ethyl acetate used in the following examples were all commercially available. The fluorosilane, ammonia, ethyl acetate, micron-sized spherical SiO2 particles, and nano-sized spherical SiO2 particles were all purchased from Shanghai Aladdin Reagent Co., Ltd., and the glass fiber powder was purchased from Taiyuan Hengtai Mineral Materials Co., Ltd.

[0030] The thermoplastic plastic screen mesh was purchased from Shanghai Haorui Wire Mesh Factory.

[0031] The stirring device used in the following examples is a heat-collecting magnetic stirrer (DF-101S) manufactured by Shanghai Lichen Bangxi Instrument Technology Co., Ltd., the mechanical stirrer is a DJ1C-60S type power-enhancing electric stirrer, the drying oven is a DZF-6051 type vacuum drying oven manufactured by Shanghai Heheng Instrument Equipment Co., Ltd., the hot press is a KH-6014H-10 type laminating hot press, and the equipment used for electrostatic adsorption is an SFC11 type electrostatic flocking machine.

[0032] The high wear-resistant superhydrophobic coatings prepared in the following examples were characterized by their hydrophobic properties by measuring the static contact angle of the coating using a contact angle measuring instrument according to GB / T30447-2013 and simultaneously measuring its roll-off angle. The hardness of the coating was tested using a QHQ-A portable pencil scratch tester according to GB / T6739-2006. The wear resistance was tested using a sandpaper cyclic abrasion test. The specific test method was as follows: a 2.5cm*6.5cm sample was placed with the coated surface in contact with No. 6 metallographic sandpaper. A 100g weight was fixed to the back of the sample. The sample was moved forward at a constant speed of 10cm under a pressure of 1.6KPa. The sample was then rotated 90° and moved forward another 10cm. The above complete process was defined as one sandpaper abrasion cycle. The above process was repeated until the sample lost its superhydrophobic properties (i.e., the contact angle was less than 150° or the roll-off angle was greater than 10°). The number of abrasion cycles was recorded.

[0033] To make the content of this invention easier to understand, the technical solution of this invention will be further described below with reference to specific embodiments, but this invention is not limited thereto.

[0034] Example 1

[0035] 1. Preparation of hydrophobic modified material: First, anhydrous ethanol, 1H,1H,2H,2H perfluorodecyltriethoxysilane (fluorosilane) and ammonia water were ultrasonically dispersed at room temperature for 30 min at a mass ratio of 100:1:6 to obtain the modifier.

[0036] Nano-spherical SiO2 particles with a particle size of 15 nm, micro-spherical SiO2 particles with a particle size of 5 μm, and glass fiber powder with a single filament diameter of 11 μm and an aspect ratio of 20 were added to the modifier to obtain a mixture of nano-spherical SiO2 particles (in which the mass percentage of nano-spherical SiO2 particles is 9.2%), a mixture of micro-spherical SiO2 particles (in which the mass percentage of micro-spherical SiO2 particles is 9.2%), and a mixture of glass fiber powder (in which the mass percentage of glass fiber powder is 9.2%).

[0037] The mixture was continuously stirred at a stirring speed of approximately 450 r / min at 40°C for 8 hours using a heat-collecting magnetic stirrer. After drying at 55°C for 8 hours, fluorinated hydrophobic nano-spherical SiO2 particles, hydrophobic micro-spherical SiO2 particles, and hydrophobic glass fiber powder were obtained for later use.

[0038] 2. Preparation of superhydrophobic coating: Using hydrophobic nano-spherical SiO2 particles, hydrophobic micron-sized spherical SiO2 particles and hydrophobic glass fiber powder, epoxy resin (E51), curing agent (T31) and ethyl acetate as raw materials, the above raw materials were stirred at room temperature for 1.5 h using a heat-collecting magnetic stirrer to obtain a superhydrophobic coating; wherein, the mass fraction of epoxy resin (E51) was 4.96%, the mass fraction of curing agent (T31) was 1.24%, the mass fraction of 15nm hydrophobic SiO2 particles was 1.65%, the mass fraction of 5μm hydrophobic SiO2 particles was 1.65%, the mass fraction of hydrophobic glass fiber was 1.20%, and the balance was ethyl acetate;

[0039] 3. Hydrophobic nano-spherical SiO2 particles, hydrophobic micron-sized spherical SiO2, and hydrophobic glass fibers are mixed in a mass ratio of 10:6:1 and stirred evenly using a mechanical stirrer at a speed of 140 r / min for 15 min to obtain hydrophobic fiber composite powder.

[0040] 4. Pretreatment of the substrate: A 7101 type glass slide was used as the substrate. The surface of the substrate was cleaned with deionized water and anhydrous ethanol in sequence, and then dried at 80°C for 1 hour.

[0041] 5. Coating Preparation: First, a polypropylene screen with an 850μm aperture was hot-pressed onto the substrate using a hot press at 120℃ for 20 minutes and a pressure of 3.5MPa. Next, the superhydrophobic coating prepared in step 2 was sprayed onto the substrate surface using a spray gun at a pressure of 4Bar, a distance of 10cm between the spray gun and the substrate, and a gun movement speed of 1.5cm / s. Then, within 10-15 minutes after spraying, the hydrophobic fiber composite powder prepared in step 3 was adsorbed onto the coating surface using an electrostatic flocking machine. The flocking voltage was 30KV, the powder output was approximately 3g / min, the flocking handle movement speed was 2cm / s, and the distance between the flocking handle outlet and the coating was 10cm. Finally, the coating was cured at 20℃ for 48 hours to obtain a highly wear-resistant superhydrophobic coating. The obtained coating thickness was 70-100μm.

[0042] The superhydrophobic coating obtained in this embodiment consists of a sieve on the substrate surface and a cured superhydrophobic composite. Testing revealed that the cured superhydrophobic composite contains 21.93% hydrophobic nanosphere SiO2, 18.40% hydrophobic micron-sized sphere SiO2, 9.53% randomly arranged hydrophobic glass fibers, and 0.88% hydrophobic glass fibers oriented perpendicular to the coating surface. The remainder is epoxy resin.

[0043] A schematic diagram of the surface morphology of the superhydrophobic coating prepared in this embodiment is shown below. Figure 1 As shown, point B is a magnified view of a portion of point A.

[0044] Example 2

[0045] 1. Preparation of hydrophobic modified material: First, anhydrous ethanol, 1H,1H,2H,2H perfluorodecyltriethoxysilane and ammonia water were ultrasonically dispersed at room temperature for 15 min in a mass ratio of 100:3:6 to obtain the modifier for later use.

[0046] Then, nano-spherical SiO2 particles with a particle size of 20 nm, micro-spherical SiO2 particles with a particle size of 10 μm, and glass fiber powder with a single filament diameter of 12.5 μm and an aspect ratio of 35 were added to the modifier respectively; nano-spherical SiO2 particle mixture (in which nano-spherical SiO2 particles account for 7.4% by mass), micro-spherical SiO2 mixture (in which micro-spherical SiO2 particles account for 7.4% by mass), and glass fiber powder mixture (in which glass fiber powder accounts for 7.4% by mass) were obtained.

[0047] Then, the three mixtures were continuously stirred at a stirring speed of about 450 r / min at 35°C for 14 h using a heat-collecting magnetic stirrer, and dried at 60°C for 10 h to obtain fluorinated hydrophobic nanosphere SiO2 particles, hydrophobic microsphere SiO2 particles, and hydrophobic glass fibers.

[0048] 2. Preparation of superhydrophobic coating: Using hydrophobic nano-spherical SiO2 particles, hydrophobic micron-sized spherical SiO2 particles, hydrophobic glass fiber, epoxy resin (E51), curing agent (T31), and ethyl acetate as raw materials, the above raw materials were stirred at room temperature for 2 hours using a heat-collecting magnetic stirrer to obtain a superhydrophobic coating; In the prepared superhydrophobic coating, the mass fraction of epoxy resin (E51) was 4.4%, the mass fraction of curing agent (T31) was 1.1%, the mass fraction of 30nm hydrophobic nano-SiO2 particles was 2.05%, the mass fraction of 10μm hydrophobic micron-sized SiO2 particles was 1.25%, the mass fraction of hydrophobic glass fiber was 0.50%, and the balance was ethyl acetate;

[0049] 3. The hydrophobic nano-spherical SiO2 particles, hydrophobic micron-sized spherical SiO2, and hydrophobic glass fibers are mixed in a mass ratio of 10:6:1.5 and stirred evenly using a mechanical stirrer at a speed of 200 r / min for 20 min to obtain hydrophobic fiber composite powder.

[0050] 4. Pretreatment of the substrate: FR4 fiberglass is used as the substrate. The surface of the substrate is cleaned with deionized water and anhydrous ethanol in sequence, and then dried at 80°C for 1 hour.

[0051] 5. Coating Preparation: First, a polypropylene screen with a pore size of 62μm is hot-pressed to the substrate using a hot press at a temperature of 140℃, a holding time of 30min, and a pressure of 4MPa. Second, the superhydrophobic coating prepared in step 2 is sprayed onto the substrate surface using a spray gun at a pressure of 5Bar, a distance of 10cm between the spray gun and the substrate, and a moving speed of 1.5cm / s. Then, within 10-15min after spraying, the hydrophobic fiber composite powder prepared in step 3 is adsorbed onto the coating surface using an electrostatic flocking machine at a voltage of 45KV, a powder output of approximately 3.5g / min, a moving speed of the flocking handle of 2cm / s, and a distance of 15cm between the outlet of the flocking handle and the coating. Finally, after curing at 60℃ for 4h, a high wear-resistant superhydrophobic coating is obtained with a thickness of 70-100μm.

[0052] The superhydrophobic coating obtained in this embodiment consists of a sieve on the substrate surface and a cured superhydrophobic composite. Testing revealed that the cured superhydrophobic composite contains 27.31% hydrophobic nanosphere SiO2, 16.57% hydrophobic micron-sized sphere SiO2, 4.57% randomly arranged hydrophobic glass fibers, and 1.29% hydrophobic glass fibers oriented perpendicular to the coating surface. The remainder is epoxy resin.

[0053] The SEM image of the coating prepared in this embodiment is shown below. Figure 2 As shown in the figure, the coating surface has micro- and nano-scale protrusions and a continuous network structure, which provides the coating with good hydrophobic properties.

[0054] Example 3

[0055] 1. Preparation of hydrophobic modified material: First, anhydrous ethanol, 1H,1H,2H,2H perfluorodecyltriethoxysilane and ammonia water were ultrasonically dispersed at room temperature for 20 min in a mass ratio of 100:2:6 to obtain the modifier for later use.

[0056] 30nm nano-SiO2 particles, 20μm micro-SiO2 particles, and glass fiber powder with a single filament diameter of 17μm and an aspect ratio of 50 were added to the modifier to obtain a mixture of nano-spherical SiO2 particles (of which the mass percentage of nano-spherical SiO2 particles was 10.7%), a mixture of micro-spherical SiO2 particles (of which the mass percentage of micro-spherical SiO2 particles was 10.7%), and a mixture of glass fiber powder (of which the mass percentage of glass fiber powder was 10.7%).

[0057] Finally, a heat-collecting magnetic stirrer was used to continuously stir at a stirring speed of about 450 r / min at 20℃ for 14 h, and then dried at 70℃ for 16 h to obtain fluorinated modified hydrophobic nano-spherical SiO2 particles, hydrophobic micro-spherical SiO2 particles and hydrophobic glass fibers.

[0058] 2. Preparation of superhydrophobic coating: Using hydrophobically treated SiO2 particles, glass fiber powder, epoxy resin, and ethyl acetate as raw materials, the above raw materials were stirred at room temperature for 3 hours using a heat-collecting magnetic stirrer to obtain a superhydrophobic coating; In the prepared superhydrophobic coating, the mass fraction of epoxy resin (E51) was 2.48%, the mass fraction of curing agent (T31) was 0.62%, the mass fraction of 30nm hydrophobic nano-SiO2 particles was 1.25%, the mass fraction of 20μm hydrophobic micro-SiO2 particles was 2.05%, the mass fraction of hydrophobic glass fiber was 0.20%, and the balance was ethyl acetate;

[0059] 3. The hydrophobic nano-spherical SiO2 particles, hydrophobic micron-sized spherical SiO2, and hydrophobic glass fibers are mixed in a mass ratio of 10:6:1.2 and stirred evenly using a mechanical stirrer at a speed of 300 r / min for 25 min to obtain hydrophobic fiber composite powder.

[0060] 4. Pretreatment of the substrate: 6101 aluminum alloy is used as the substrate. The surface of the substrate is cleaned with deionized water and anhydrous ethanol in sequence, and then dried at 80°C for 1 hour.

[0061] 5. Coating Preparation: First, a polypropylene screen with an 11μm aperture was hot-pressed onto the substrate using a hot press at a temperature of 110℃, a holding time of 15min, and a pressure of 5MPa. Next, the superhydrophobic coating prepared in step 2 was sprayed onto the substrate surface using a spray gun at a pressure of 6Bar, a distance of 10cm between the spray gun and the substrate, and a gun movement speed of 1.5cm / s. Then, within 10-15min after spraying, an electrostatic flocking machine was used to adsorb the hydrophobic fiber composite powder prepared in step 3 onto the coating surface. The flocking voltage was 50KV, the powder output was approximately 5g / min, the flocking handle movement speed was 2cm / s, and the distance between the flocking handle outlet and the coating was 12cm. Finally, after curing at 80℃ for 1.5h, a high-wear-resistant superhydrophobic coating was obtained with a thickness of 70-100μm.

[0062] The superhydrophobic coating obtained in this embodiment consists of a sieve on the substrate surface and a cured superhydrophobic composite. Testing revealed that the cured superhydrophobic composite contains 24.82% hydrophobic nanosphere SiO2, 31.63% hydrophobic micron-sized sphere SiO2, 2.58% randomly arranged hydrophobic glass fibers, and 1.05% hydrophobic glass fibers oriented perpendicular to the coating surface. The remainder is epoxy resin.

[0063] The actual photograph of the coating prepared in this embodiment is shown below. Figure 3 As shown.

[0064] Comparative Example 1

[0065] In Example 1, step 2, the superhydrophobic coating used does not contain hydrophobic micron-sized spherical SiO2 particles or hydrophobic glass fiber powder. The mass fraction of hydrophobic nano-spherical SiO2 in the coating is 4.50%, and the remaining operations are the same as in Example 1.

[0066] Comparative Example 2

[0067] In the superhydrophobic coating preparation process described in step 5 of Example 1, the screen is not hot-pressed onto the substrate surface; the remaining operations are the same as in Example 1.

[0068] The hydrophobic properties, coating hardness, and wear resistance of Examples 1, 2, 3, and Comparative Examples 1 and 2 were tested using the aforementioned method. The test results are shown in Tables 1 and 2.

[0069] Table 1. Test results of the hydrophobic properties of the superhydrophobic coatings obtained in Examples 1-3 and Comparative Examples 1-2.

[0070]

[0071] Table 2. Test results of hardness and wear resistance of the superhydrophobic coatings obtained in Examples 1-3 and Comparative Examples 1-2.

[0072]

[0073] The above description is only a part of the embodiments of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention shall be covered by the present invention.

Claims

1. A method for preparing a highly wear-resistant superhydrophobic coating, characterized in that, Includes the following steps: 1) Hydrophobic modification treatment was performed on nano-spherical SiO2 particles, micron-sized spherical SiO2 particles, and glass fiber powder respectively to obtain hydrophobic nano-spherical SiO2 particles, hydrophobic micron-sized spherical SiO2 particles, and hydrophobic glass fibers; the particle sizes of the nano-spherical SiO2 particles and micron-sized spherical SiO2 particles were 15-30 nm and 5-20 μm, respectively; the single filament diameter of the glass fibers was 11-17 μm, and the aspect ratio was 20-50; 2) Mix hydrophobic nanosphere SiO2, hydrophobic micron sphere SiO2, hydrophobic glass fiber, epoxy resin, curing agent and ethyl acetate at room temperature for 1.5-3 hours to obtain a superhydrophobic coating for later use; In the obtained superhydrophobic coating, the mass percentage of epoxy resin is 2.48-4.96%, the mass percentage of curing agent is 0.62-1.24%, the mass percentage of hydrophobic nano-spherical SiO2 particles is 1.25-2.05%, the mass percentage of hydrophobic micron-sized spherical SiO2 particles is 1.25-2.05%, the mass percentage of hydrophobic glass fiber is 0.20-1.2%, and the balance is ethyl acetate; 3) Mix hydrophobic nano-spherical SiO2 particles, hydrophobic micron-sized spherical SiO2, and hydrophobic glass fibers evenly at a mass ratio of 10:6:1-1.5 to obtain hydrophobic fiber composite powder for later use. 4) Clean the substrate surface sequentially with deionized water and anhydrous ethanol, then dry it for later use; 5) Press the screen onto the substrate surface with hot heat, then spray the superhydrophobic coating obtained in step 2) to form a superhydrophobic coating layer; then electrostatically flock the hydrophobic fiber composite powder prepared in step 3) onto the surface of the hydrophobic coating layer, and cure at 20-80℃ for 1.5-48h to obtain the high wear-resistant superhydrophobic coating.

2. The method for preparing the high wear-resistant superhydrophobic coating according to claim 1, characterized in that, The sieve has an aperture of 11-850 μm.

3. The method for preparing the high wear-resistant superhydrophobic coating according to claim 1, characterized in that, Step 1) The hydrophobic modification treatment refers to the following specific steps: a) Mixing anhydrous ethanol, 1H,1H,2H,2H perfluorodecyltriethoxysilane and ammonia water at a mass ratio of 100:1-3:6 and then ultrasonically dispersing the mixture to obtain a modifier; b) Adding nano-spherical SiO2 particles, micron-sized spherical SiO2, and glass fibers to the modifier at a mass fraction of 7.4-10.7% to obtain nano-spherical SiO2 particle mixture, micron-sized spherical SiO2 mixture, and glass fiber mixture, respectively; c) Stirring the three mixtures obtained in step b) at 20-40℃ for 8-14 hours, and then drying them at 55-70℃ for 8-16 hours to obtain the hydrophobic nano-spherical SiO2 particles, hydrophobic micron-sized spherical SiO2, and hydrophobic glass fibers, respectively.

4. The method for preparing the high wear-resistant superhydrophobic coating according to claim 1, characterized in that, Step 5) The hot pressing refers to a hot pressing temperature of 110-140℃, a pressure of 3.5-5MPa, and a hot pressing time of 15-30min.

5. The method for preparing the high wear-resistant superhydrophobic coating according to claim 1, characterized in that, Step 5) The coating thickness is 70-100μm.

6. The method for preparing the high wear-resistant superhydrophobic coating according to claim 1, characterized in that, Step 5) The electrostatic flocking refers to a flocking voltage of 30-50KV, a hydrophobic fiber composite powder output of 3-5g / min, a moving speed of 2cm / s for the electrostatic flocking machine, and a distance of 10-15cm between the outlet of the electrostatic flocking machine and the coating.

7. The method for preparing the high wear-resistant superhydrophobic coating according to claim 1, characterized in that, The screen is made of thermoplastic plastic.

8. The high wear-resistant superhydrophobic coating obtained by the preparation method according to any one of claims 1-7.

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