Self-cleaning coating metal curtain wall plate and preparation method thereof

Abstract

The invention belongs to the technical field of building curtain wall plate manufacturing, and particularly relates to a self-cleaning coating metal curtain wall plate and a preparation method thereof. The method comprises the following steps: S1, carrying out micro-corrosion on the surface of a metal substrate by using acid, and attaching a sputtering layer on the surface of the metal substrate subjected to micro-corrosion through magnetron sputtering; s2, sequentially performing dopamine and polystyrene on the surfaces of the hollow glass beads, and forming polystyrene hydrophobic layers with micro-nano structures on the surfaces of the hollow glass beads; then mixing the polystyrenated dopamine hollow glass beads, polydimethylsiloxane and petroleum ether to obtain a hydrophobic coating; and S3, the metal base plate subjected to surface pretreatment is coated with the hydrophobic coating, heating and curing are conducted, and the self-cleaning coating metal curtain wall plate is obtained. Compared with the prior art, the self-cleaning coating metal curtain wall plate serves as a decorative plate, the attractiveness of a building can be improved, the maintenance cost can be reduced to a great extent, and safety and durability are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of building curtain wall panel manufacturing, and particularly relates to a self-cleaning coated metal curtain wall panel and a preparation method thereof. Background Art

[0002] With the acceleration of urbanization, the aesthetics and durability of building exterior walls have become the focus of people's attention. Traditional metal curtain wall panels, such as stainless steel curtain wall panels, have good weather resistance and decorative properties, but in actual use, they will be affected by the accumulation of rain, dust and pollutants. In order to maintain the beauty of curtain wall panels and extend their service life, manual cleaning is usually required regularly, which not only consumes a lot of manpower and material resources, but also has a high safety risk when cleaning the exterior walls of high-rise buildings.

[0003] At present, self-cleaning coating technology based on photocatalysis has been widely studied, such as titanium dioxide photocatalytic coating, which can decompose organic pollutants under ultraviolet light. However, such coatings usually rely on specific environmental conditions and are prone to shedding and performance degradation over time. In addition, such coatings focus more on solving the problem of catalytic decomposition of specific pollutants, but often cannot solve the problem of rainwater and pollutants being retained on the surface. After the rainwater dries, it is still easy for the pollutants carried in it to adhere to the coating surface to form stains, which is particularly obvious on the surface of stainless steel metal substrates. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a self-cleaning coated metal curtain wall panel and a preparation method thereof. The purpose of the present invention is to provide a super-hydrophobic metal curtain wall panel using coating technology, reduce the residence time of water droplets on the curtain wall surface, ensure the long-term stability of the coating, extend the service life of the curtain wall panel, reduce the need for manual cleaning, and reduce maintenance costs and safety risks.

[0005] The first aspect of the present invention is to provide a method for preparing a self-cleaning coated metal curtain wall panel, comprising the following steps:

[0006] Step S1: Surface pretreatment of metal substrate

[0007] The method comprises using an acid to micro-etch the surface of a metal substrate and attaching a sputtering layer to the surface of the micro-etched metal substrate by magnetron sputtering;

[0008] Step S2: Preparation of micro-nanostructure hydrophobic coating

[0009] The method comprises the steps of sequentially performing dopamination and polystyrene on the surface of hollow glass microspheres to form a polystyrene hydrophobic layer with a micro-nano structure on the surface of the hollow glass microspheres; and then mixing the polystyrene-treated dopamination hollow glass microspheres, polydimethylsiloxane and petroleum ether to obtain a hydrophobic coating;

[0010] Step S3: Application of coating

[0011] The hydrophobic coating prepared in step S2 is coated on the metal substrate prepared in step S1 and subjected to surface pretreatment, and heated and cured to obtain the self-cleaning coated metal curtain wall panel.

[0012] As a further optimization scheme for the preparation method of self-cleaning coated metal curtain wall panels, in step S1, the micro-corrosion of the metal substrate is to use a hydrochloric acid solution to micro-corrode the surface of the stainless steel substrate, the stainless steel substrate is immersed in a hydrochloric acid solution with a mass concentration of 3.0% to 6.0%, ultrasonically oscillated for 60s to 120s, and then cleaned to remove the residual acid on the surface, and dried to obtain a micro-corroded stainless steel substrate.

[0013] As a further optimization scheme for the preparation method of the self-cleaning coated metal curtain wall panel, in step S1, the sputtering layer is formed by the following steps: fixing the stainless steel substrate that has been micro-corroded in a sputtering device for magnetron sputtering coating, the distance between the substrate and the target material is 20±1cm, and the sputtering target material is a mixed powder of high-purity nickel powder, high-purity copper powder and high-purity molybdenum silicide powder, and the mass ratio of the three is 100:(15-25):(10-15); evacuating to 10 -3 Pa~10 -5 Pa, argon is the process gas, and the flow rate is 50cm 3 / min~80cm 3 / min, the sputtering power is 600W~800W, and the sputtering lasts for 3min~5min.

[0014] As a further optimization scheme for the preparation method of self-cleaning coated metal curtain wall panels, in step S2, dopamine hollow glass microspheres are prepared by the following steps: 1 mol / L trishydroxymethylaminomethane hydrochloride (Tris-HCl) solution is added dropwise to an aqueous solution of dopamine with a mass concentration of 0.25%, the solution pH is adjusted to 9, and then hollow glass microspheres with a particle size of 10±2 μm are added, mechanically stirred at room temperature for more than 10 hours, and dopamine hollow glass microspheres are obtained by filtering, washing, and drying.

[0015] As a further optimization scheme for the preparation method of self-cleaning coated metal curtain wall panels, in step S2, polystyrene-doped hollow glass microspheres are prepared by the following steps: dopamine-doped hollow glass microspheres, polyvinyl pyrrolidone, styrene and deionized water in a mass ratio of (3-5):(0.8-1.2):(5-8):100 are added to a reaction container, heated to 65°C, and a potassium persulfate aqueous solution with a mass concentration of 1.5% is slowly added under high-speed stirring, and the mass ratio of the potassium persulfate aqueous solution to the deionized water added to the reaction container is (60-80):100; after the addition is completed, stirring and reacting are continued for more than 12 hours, and after cooling, the polystyrene-doped hollow glass microspheres are obtained by filtering, washing and drying.

[0016] As a further optimization scheme for the preparation method of self-cleaning coated metal curtain wall panels, in step S2, it is prepared by the following steps: polystyrene-doped hollow glass microspheres, polydimethylsiloxane and petroleum ether in a mass ratio of (4.0-5.5):(0.4-0.6):100 are added into a mixing container, and stirred to form a uniform dispersion, i.e., a micro-nanostructured hydrophobic coating.

[0017] As a further optimization scheme for the preparation method of self-cleaning coated metal curtain wall panels, in step S3, the hydrophobic coating prepared in step S2 is sprayed on the surface pretreated metal substrate prepared in step S1 using a spray gun, naturally dried, and then heated and cured to obtain a self-cleaning coated metal curtain wall panel.

[0018] As a further optimization scheme for the preparation method of the self-cleaning coated metal curtain wall panel, in step S3, the controlled spraying amount of the hydrophobic coating is 15 g / m 2 ~30g / m 2 After natural drying, place in a 65°C oven to cure for 3 hours to form a self-cleaning coated metal curtain wall panel.

[0019] As a further optimization scheme for the preparation method of the self-cleaning coated metal curtain wall panel, the metal substrate is a 304 stainless steel metal substrate.

[0020] The second aspect of the present invention is to provide a self-cleaning coated metal curtain wall panel, that is, a metal curtain wall panel prepared by the above preparation method, which has excellent hydrophobicity and durability and can be widely used in decorative curtain walls of various outdoor buildings.

[0021] Beneficial Effects

[0022] Compared with the prior art, the self-cleaning coated metal curtain wall panel provided by the present invention, as a decorative panel, can not only improve the aesthetics of the building, but also greatly reduce the maintenance cost and improve safety and durability.

[0023] Because curtain wall panels are super hydrophobic, water droplets are not easy to stay on the surface of the curtain wall. Under the action of gravity, wind and other natural forces, water droplets can slide down quickly, effectively preventing water stains from depositing and leaving stains. In the natural environment, outdoor rain can take away dust on the surface, reducing the need for regular cleaning, thereby reducing maintenance costs, reducing the safety risks of high-altitude operations, and reducing the use of chemical cleaners for exterior walls.

[0024] The super-hydrophobic coating on the surface of the curtain wall panel is not only wear-resistant, but also has extremely strong stability and durability on the surface of the stainless steel substrate. Even in severe weather conditions such as strong winds and blowing sand, the coating can still maintain excellent hydrophobic properties for a long time. DETAILED DESCRIPTION

[0025] The present invention is further illustrated by specific examples below. These examples are exemplary and are intended to illustrate the problem and explain the present invention, but are not intended to be limiting.

[0026] The self-cleaning coated metal curtain wall panel is prepared by the following steps.

[0027] Step S1: Surface pretreatment of metal substrate

[0028] Use hydrochloric acid solution to micro-etch the surface of 304 stainless steel substrate. Soak the 304 stainless steel substrate in a hydrochloric acid solution with a mass concentration of 3.0% to 6.0%, and ultrasonically oscillate for 60s to 120s. Immediately take out the 304 stainless steel substrate and place it in flowing deionized water for preliminary rinsing. Gently shake the substrate to remove the hydrochloric acid solution and other impurities remaining on the surface. Subsequently, place the substrate in an ultrasonic cleaning tank containing deionized water and ultrasonically clean it for 180s to 300s. Place the cleaned 304 stainless steel substrate in a hot air drying oven at 120°C for 5 hours until completely dry, and cool to room temperature.

[0029] The surface of the 304 stainless steel substrate after micro-etching was vacuum magnetron sputtering coating. First, the substrate was fixed in the sputtering device, and the distance between the substrate and the target was kept at 20±1cm. The sputtering target was a mixed powder of high-purity nickel powder, high-purity copper powder and high-purity molybdenum silicide powder, and the mass ratio of the three was 100:(15~25):(10~15). Vacuum to 10 -3 Pa~10 -5 Pa, and then introduced argon as the process gas, with the flow rate controlled at 50cm 3 / min~80cm 3 / min, set the sputtering power to 600W~800W, start sputtering and continue for 3min~5min. During the whole sputtering process, closely monitor the stability of process parameters such as vacuum degree, gas flow and sputtering power. After sputtering, take out the coated 304 stainless steel substrate.

[0030] Step S2: Preparation of micro-nanostructure hydrophobic coating

[0031] 1 mol / L tris(hydroxymethyl)aminomethane hydrochloride) solution (Tris-HCl) was added dropwise to an aqueous solution of dopamine with a mass concentration of 0.25%, and the pH of the solution was adjusted to about 9, and then hollow glass microspheres with a particle size of 10±2 μm were added, and mechanical stirring was performed at room temperature for 10 hours. The hollow glass microspheres were then filtered out, washed three times with deionized water, and vacuum dried to obtain dopamine hollow glass microspheres.

[0032] Dopaminated hollow glass microspheres, polyvinyl pyrrolidone, styrene and deionized water in a mass ratio of (3-5):(0.8-1.2):(5-8):100 are added to a reaction container, heated to 65°C, stirred at a high speed of 800 r / min, and a potassium persulfate aqueous solution with a mass concentration of 1.5% is slowly added dropwise, wherein the mass ratio of the potassium persulfate aqueous solution to the deionized water added to the reaction container is (60-80):100; after the addition is completed, stirring and reacting are continued for 12 hours, then the solid is cooled and filtered out, washed three times with deionized water, and vacuum dried to obtain polystyrene-dopaminated hollow glass microspheres.

[0033] Polystyrenated dopamine hollow glass microspheres, polydimethylsiloxane and petroleum ether in a mass ratio of (4.0-5.5):(0.4-0.6):100 were added into a mixing container, and mechanical stirring was performed for 5 minutes to form a uniform dispersion, namely, a micro-nanostructure hydrophobic coating.

[0034] Step S3: Application of coating

[0035] Use a spray gun to spray the micro-nanostructure hydrophobic coating prepared in step S2 onto the surface pretreated 304 stainless steel metal substrate prepared in step S1, and control the spraying amount to 15 g / m 2 ~30g / m 2 The coated metal substrate was naturally dried, and then placed in an oven at 65°C for curing for 3 hours, and a self-cleaning coated metal curtain wall panel was obtained after natural cooling.

[0036] In step S1, a hydrochloric acid solution is used to micro-etch the surface of a 304 stainless steel substrate to improve the properties of the substrate surface so that the subsequent coating layer can adhere better. An oxide layer is usually formed naturally on the surface of stainless steel, which can protect the material from further corrosion. However, the oxide layer on the surface of the stainless steel substrate will also form a small number of holes, looseness and other minor defects under natural conditions. Through hydrochloric acid corrosion, part of the oxide with unstable surface adhesion is removed, exposing a relatively pure and stable metal surface. In addition, the slight etching effect of hydrochloric acid also increases the microscopic roughness of the material surface, thereby enhancing the mechanical bite between the subsequent coating layer and the substrate. Next, high-purity nickel powder, high-purity copper powder and high-purity molybdenum silicide powder containing a mass ratio of 100: (15-25): (10-15) are sputtered on the surface of a 304 stainless steel substrate as a target material. Experiments have found that the film layer formed by sputtering this target material can not only be well combined with the stainless steel substrate, but also can enhance the bonding force of the subsequent coating.

[0037] In step S2, hollow glass microspheres are added to a buffer solution containing dopamine, so that dopamine is self-polymerized on the surface of hollow glass microspheres, and dopamine is used to form a layer of dopamine chemical layer with adhesiveness on the surface of hollow glass microspheres. Then, polystyrene is formed on the surface of dopaminized hollow glass microspheres. As a hydrophobic polymer, polystyrene can form a hydrophobic layer on the surface of hollow glass microspheres, which helps to improve the hydrophobic effect. Moreover, the polarity of polystyrene is relatively small, and the polarity of dopamine on the surface of hollow glass microspheres is relatively large, and a certain polarity difference is formed between the two, so that polystyrene cannot spontaneously form a smooth polystyrene film layer on the surface, but tends to form an uneven secondary micro-nano structure. The polystyrene material with low surface energy combines this secondary micro-nano structure, similar to the papilla on the surface of lotus leaf, and gives the super-hydrophobic characteristic of hollow glass microspheres. Then, this super-hydrophobic hollow glass microspheres are dispersed in a large amount in coating to make a super-hydrophobic hydrophobic coating.

[0038] In step S3, super hydrophobic hydrophobic coating is coated on pretreated stainless steel substrate surface to form strong adhesion. After coating solidification, hollow glass microbeads with micro-nano super hydrophobic structure are dispersed in a large number on coating surface, giving coating super hydrophobic performance. In addition, after coating solidification, this part of hollow glass microbeads located on coating surface also forms concavo-convex structure on micron scale, further reduces contact with water, is conducive to the rolling of water droplets on material surface.

[0039] The self-cleaning coated metal curtain wall panels produced by this method can be widely used in the protection and decoration of outdoor building exterior walls. Its super-hydrophobicity makes it difficult for rainwater to adhere to it. It naturally rolls off under the action of outdoor gravity and wind, preventing the impurities in the water droplets from being gradually dried by air or sun on the curtain wall surface and then deposited on the curtain wall surface to form stubborn water stains. This feature significantly reduces the need for manual cleaning of the exterior wall, not only reducing maintenance costs, but also greatly improving safety and avoiding potential risks brought by high-altitude operations.

[0040] Example 1

[0041] Step S1: Surface pretreatment of metal substrate

[0042] Use hydrochloric acid solution to micro-etch the surface of 304 stainless steel substrate. Soak the 304 stainless steel substrate in a hydrochloric acid solution with a mass concentration of 3.0% and ultrasonically oscillate for 60 seconds. Immediately take out the 304 stainless steel substrate and place it in flowing deionized water for preliminary rinsing. Gently shake the substrate to remove the hydrochloric acid solution and other impurities remaining on the surface. Subsequently, place the substrate in an ultrasonic cleaning tank containing deionized water and ultrasonically clean it for 180 seconds. Place the cleaned 304 stainless steel substrate in a hot air drying oven at 120°C for 5 hours until it is completely dry and cool to room temperature.

[0043] The surface of the 304 stainless steel substrate after micro-etching was vacuum magnetron sputtering coating. First, the substrate was fixed in the sputtering device, and the distance between the substrate and the target was kept at 20 cm. The sputtering target was a mixed powder of high-purity nickel powder, high-purity copper powder and high-purity molybdenum silicide powder, with a mass ratio of 100:15:10. Vacuum to 10 -4 Pa, and then introduced argon as the process gas, with a flow rate of 50cm 3 / min, set the sputtering power to 600W, start sputtering and continue for 3min. During the whole sputtering process, closely monitor the stability of process parameters such as vacuum degree, gas flow and sputtering power. After sputtering, take out the coated 304 stainless steel substrate.

[0044] Step S2: Preparation of micro-nanostructure hydrophobic coating

[0045] 1 mol / L tris(hydroxymethyl)aminomethane hydrochloride) solution (Tris-HCl) was added dropwise to an aqueous solution of dopamine with a mass concentration of 0.25%, and the pH of the solution was adjusted to about 9, and then hollow glass microspheres with a particle size of 10±2 μm were added, and mechanical stirring was performed at room temperature for 10 hours. The hollow glass microspheres were then filtered out, washed three times with deionized water, and vacuum dried to obtain dopamine hollow glass microspheres.

[0046] Dopaminated hollow glass microspheres, polyvinyl pyrrolidone, styrene and deionized water in a mass ratio of 3:0.8:5:100 were added into a reaction container, heated to 65°C, stirred at a high speed of 800 r / min, and a potassium persulfate aqueous solution with a mass concentration of 1.5% was slowly added dropwise, and the mass ratio of the potassium persulfate aqueous solution to the deionized water added to the reaction container was 60:100; after the addition was completed, stirring and reacting were continued for 12 hours, and then the solid was cooled and filtered out, washed three times with deionized water, and vacuum dried to obtain polystyrene-dopaminated hollow glass microspheres.

[0047] Polystyrene-doped hollow glass microspheres, polydimethylsiloxane and petroleum ether were added in a mass ratio of 4.0:0.4:100 into a mixing container, and mechanically stirred for 5 minutes to form a uniform dispersion, namely, a micro-nanostructure hydrophobic coating.

[0048] Step S3: Application of coating

[0049] Use a spray gun to spray the micro-nanostructure hydrophobic coating prepared in step S2 onto the surface pretreated 304 stainless steel metal substrate prepared in step S1, and control the spraying amount to 15 g / m 2 The coated metal substrate was naturally dried, and then placed in an oven at 65°C for curing for 3 hours, and a self-cleaning coated metal curtain wall panel was obtained after natural cooling.

[0050] Example 2

[0051] Step S1: Surface pretreatment of metal substrate

[0052] Use hydrochloric acid solution to micro-etch the surface of 304 stainless steel substrate. Soak the 304 stainless steel substrate in a hydrochloric acid solution with a mass concentration of 4.0% and ultrasonically oscillate for 80 seconds. Immediately take out the 304 stainless steel substrate and place it in flowing deionized water for preliminary rinsing. Gently shake the substrate to remove the hydrochloric acid solution and other impurities remaining on the surface. Subsequently, place the substrate in an ultrasonic cleaning tank containing deionized water and ultrasonically clean it for 240 seconds. Place the cleaned 304 stainless steel substrate in a hot air drying oven at 120°C for 5 hours until it is completely dry and cool to room temperature.

[0053] The surface of the 304 stainless steel substrate after micro-etching was vacuum magnetron sputtering coating. First, the substrate was fixed in the sputtering device, and the distance between the substrate and the target was kept at 20 cm. The sputtering target was a mixed powder of high-purity nickel powder, high-purity copper powder and high-purity molybdenum silicide powder, with a mass ratio of 100:20:10. Vacuum to 10 -4 Pa, and then introduced argon as the process gas, with the flow rate controlled at 60cm 3 / min, set the sputtering power to 700W, start sputtering and continue for 4 minutes. During the entire sputtering process, closely monitor the stability of process parameters such as vacuum degree, gas flow and sputtering power. After sputtering, take out the coated 304 stainless steel substrate.

[0054] Step S2: Preparation of micro-nanostructure hydrophobic coating

[0055] 1 mol / L tris(hydroxymethyl)aminomethane hydrochloride) solution (Tris-HCl) was added dropwise to an aqueous solution of dopamine with a mass concentration of 0.25%, and the pH of the solution was adjusted to about 9, and then hollow glass microspheres with a particle size of 10±2 μm were added, and mechanical stirring was performed at room temperature for 10 hours. The hollow glass microspheres were then filtered out, washed three times with deionized water, and vacuum dried to obtain dopamine hollow glass microspheres.

[0056] Dopamined hollow glass microspheres, polyvinyl pyrrolidone, styrene and deionized water in a mass ratio of 4:0.9:5:100 were added into a reaction container, heated to 65°C, stirred at a high speed of 800 r / min, and a potassium persulfate aqueous solution with a mass concentration of 1.5% was slowly added dropwise, and the mass ratio of the potassium persulfate aqueous solution to the deionized water added to the reaction container was 70:100; after the addition was completed, stirring and reacting were continued for 12 hours, and then the solid was cooled and filtered out, washed three times with deionized water, and vacuum dried to obtain polystyrene-dopaminated hollow glass microspheres.

[0057] Polystyrene-doped hollow glass microspheres, polydimethylsiloxane and petroleum ether were added in a mass ratio of 4.5:0.5:100 into a mixing container, and mechanically stirred for 5 minutes to form a uniform dispersion, namely, a micro-nanostructure hydrophobic coating.

[0058] Step S3: Application of coating

[0059] Use a spray gun to spray the micro-nanostructure hydrophobic coating prepared in step S2 onto the surface pretreated 304 stainless steel metal substrate prepared in step S1, and control the spraying amount to 20 g / m 2 The coated metal substrate was naturally dried, and then placed in an oven at 65°C for curing for 3 hours, and a self-cleaning coated metal curtain wall panel was obtained after natural cooling.

[0060] Example 3

[0061] Step S1: Surface pretreatment of metal substrate

[0062] Use hydrochloric acid solution to micro-etch the surface of 304 stainless steel substrate. Soak the 304 stainless steel substrate in a hydrochloric acid solution with a mass concentration of 5.0% and ultrasonically oscillate for 90 seconds. Immediately take out the 304 stainless steel substrate and place it in flowing deionized water for preliminary rinsing. Gently shake the substrate to remove the hydrochloric acid solution and other impurities remaining on the surface. Subsequently, place the substrate in an ultrasonic cleaning tank containing deionized water and ultrasonically clean it for 240 seconds. Place the cleaned 304 stainless steel substrate in a hot air drying oven at 120°C for 5 hours until it is completely dry and cool to room temperature.

[0063] The surface of the 304 stainless steel substrate after micro-corrosion treatment was vacuum magnetron sputtering coated. First, the substrate was fixed in the sputtering device, and the distance between the substrate and the target was kept at 20 cm. The sputtering target was a mixed powder of high-purity nickel powder, high-purity copper powder and high-purity molybdenum silicide powder, with a mass ratio of 100:20:12. The vacuum was evacuated to 10-4Pa, and then argon was introduced as the process gas, and the flow rate was controlled at 70cm 3 / min, set the sputtering power to 700W, start sputtering and continue for 4 minutes. During the entire sputtering process, closely monitor the stability of process parameters such as vacuum degree, gas flow and sputtering power. After sputtering, take out the coated 304 stainless steel substrate.

[0064] Step S2: Preparation of micro-nanostructure hydrophobic coating

[0065] 1 mol / L tris(hydroxymethyl)aminomethane hydrochloride) solution (Tris-HCl) was added dropwise to an aqueous solution of dopamine with a mass concentration of 0.25%, and the pH of the solution was adjusted to about 9, and then hollow glass microspheres with a particle size of 10±2 μm were added, and mechanical stirring was performed at room temperature for 10 hours. The hollow glass microspheres were then filtered out, washed three times with deionized water, and vacuum dried to obtain dopamine hollow glass microspheres.

[0066] Add dopaminated hollow glass microspheres, polyvinyl pyrrolidone, styrene and deionized water in a mass ratio of 4:1.0:7:100 into a reaction container, heat to 65°C, stir at a high speed of 800 r / min, slowly drop a 1.5% potassium persulfate aqueous solution, and the mass ratio of the potassium persulfate aqueous solution to the deionized water added to the reaction container is 70:100; after the dropwise addition is completed, continue to stir and react for 12 hours, then cool and filter out the solid, wash three times with deionized water, and vacuum dry to obtain polystyrene-dopaminated hollow glass microspheres.

[0067] Polystyrene-doped hollow glass microspheres, polydimethylsiloxane and petroleum ether were added in a mass ratio of 5.0:0.55:100 into a mixing container, and mechanically stirred for 5 minutes to form a uniform dispersion, namely, a micro-nanostructure hydrophobic coating.

[0068] Step S3: Application of coating

[0069] Use a spray gun to spray the micro-nanostructure hydrophobic coating prepared in step S2 onto the surface pretreated 304 stainless steel metal substrate prepared in step S1, and control the spraying amount to 20 g / m 2 The coated metal substrate was naturally dried, and then placed in an oven at 65°C for curing for 3 hours, and a self-cleaning coated metal curtain wall panel was obtained after natural cooling.

[0070] Example 4

[0071] Step S1: Surface pretreatment of metal substrate

[0072] Use hydrochloric acid solution to micro-etch the surface of 304 stainless steel substrate. Soak the 304 stainless steel substrate in a hydrochloric acid solution with a mass concentration of 5.5% and ultrasonically oscillate for 100 seconds. Immediately take out the 304 stainless steel substrate and place it in flowing deionized water for preliminary rinsing. Gently shake the substrate to remove the hydrochloric acid solution and other impurities remaining on the surface. Subsequently, place the substrate in an ultrasonic cleaning tank containing deionized water and ultrasonically clean it for 270 seconds. Place the cleaned 304 stainless steel substrate in a hot air drying oven at 120°C for 5 hours until it is completely dry and cool to room temperature.

[0073] The surface of the 304 stainless steel substrate after micro-etching was vacuum magnetron sputtering coating. First, the substrate was fixed in the sputtering device, and the distance between the substrate and the target was kept at 20 cm. The sputtering target was a mixed powder of high-purity nickel powder, high-purity copper powder and high-purity molybdenum silicide powder, with a mass ratio of 100:22:13. Vacuum to 10 -4 Pa, and then introduced argon as the process gas, with the flow rate controlled at 60cm 3 / min, set the sputtering power to 700W, start sputtering and continue for 4 minutes. During the entire sputtering process, closely monitor the stability of process parameters such as vacuum degree, gas flow and sputtering power. After sputtering, take out the coated 304 stainless steel substrate.

[0074] Step S2: Preparation of micro-nanostructure hydrophobic coating

[0075] 1 mol / L tris(hydroxymethyl)aminomethane hydrochloride) solution (Tris-HCl) was added dropwise to an aqueous solution of dopamine with a mass concentration of 0.25%, and the pH of the solution was adjusted to about 9, and then hollow glass microspheres with a particle size of 10±2 μm were added, and mechanical stirring was performed at room temperature for 10 hours. The hollow glass microspheres were then filtered out, washed three times with deionized water, and vacuum dried to obtain dopamine hollow glass microspheres.

[0076] Dopamine hollow glass microspheres, polyvinyl pyrrolidone, styrene and deionized water in a mass ratio of 4:1.1:5:100 were added into a reaction container, heated to 65°C, stirred at a high speed of 800 r / min, and a potassium persulfate aqueous solution with a mass concentration of 1.5% was slowly added dropwise, and the mass ratio of the potassium persulfate aqueous solution to the deionized water added to the reaction container was 70:100; after the addition was completed, stirring and reacting were continued for 12 hours, and then the solid was cooled and filtered out, washed three times with deionized water, and vacuum dried to obtain polystyrene-dopaminated hollow glass microspheres.

[0077] Polystyrenated dopamine hollow glass microspheres, polydimethylsiloxane and petroleum ether in a mass ratio of 4.8:0.53:100 were added into a mixing container and mechanically stirred for 5 minutes to form a uniform dispersion, i.e., a micro-nanostructured hydrophobic coating.

[0078] Step S3: Application of coating

[0079] Use a spray gun to spray the micro-nanostructure hydrophobic coating prepared in step S2 onto the surface pretreated 304 stainless steel metal substrate prepared in step S1, and control the spraying amount to 20 g / m 2 The coated metal substrate was naturally dried, and then placed in an oven at 65°C for curing for 3 hours, and a self-cleaning coated metal curtain wall panel was obtained after natural cooling.

[0080] Example 5

[0081] Step S1: Surface pretreatment of metal substrate

[0082] Use hydrochloric acid solution to micro-etch the surface of 304 stainless steel substrate. Soak the 304 stainless steel substrate in a hydrochloric acid solution with a mass concentration of 5.5% and ultrasonically oscillate for 110 seconds. Immediately take out the 304 stainless steel substrate and place it in flowing deionized water for preliminary rinsing. Gently shake the substrate to remove the hydrochloric acid solution and other impurities remaining on the surface. Subsequently, place the substrate in an ultrasonic cleaning tank containing deionized water and ultrasonically clean it for 220 seconds. Place the cleaned 304 stainless steel substrate in a hot air drying oven at 120°C for 5 hours until it is completely dry and cool to room temperature.

[0083] The surface of the 304 stainless steel substrate after micro-corrosion treatment was vacuum magnetron sputtering coated. First, the substrate was fixed in the sputtering device, and the distance between the substrate and the target was kept at 20 cm. The sputtering target was a mixed powder of high-purity nickel powder, high-purity copper powder and high-purity molybdenum silicide powder, with a mass ratio of 100:20:15. The vacuum was evacuated to 10-4Pa, and then argon was introduced as the process gas, and the flow rate was controlled at 80cm 3 / min, set the sputtering power to 700W, start sputtering and continue for 4 minutes. During the entire sputtering process, closely monitor the stability of process parameters such as vacuum degree, gas flow and sputtering power. After sputtering, take out the coated 304 stainless steel substrate.

[0084] Step S2: Preparation of micro-nanostructure hydrophobic coating

[0085] 1 mol / L tris(hydroxymethyl)aminomethane hydrochloride) solution (Tris-HCl) was added dropwise to an aqueous solution of dopamine with a mass concentration of 0.25%, and the pH of the solution was adjusted to about 9, and then hollow glass microspheres with a particle size of 10±2 μm were added, and mechanical stirring was performed at room temperature for 10 hours. The hollow glass microspheres were then filtered out, washed three times with deionized water, and vacuum dried to obtain dopamine hollow glass microspheres.

[0086] Dopamine hollow glass microspheres, polyvinyl pyrrolidone, styrene and deionized water in a mass ratio of 5:0.8:7:100 were added into a reaction container, heated to 65°C, stirred at a high speed of 800 r / min, and a potassium persulfate aqueous solution with a mass concentration of 1.5% was slowly added dropwise, and the mass ratio of the potassium persulfate aqueous solution to the deionized water added to the reaction container was 70:100; after the addition was completed, stirring and reacting were continued for 12 hours, and then the solid was cooled and filtered out, washed three times with deionized water, and vacuum dried to obtain polystyrene-dopaminated hollow glass microspheres.

[0087] Polystyrenated dopamine hollow glass microspheres, polydimethylsiloxane and petroleum ether in a mass ratio of 5.5:0.45:100 were added to a mixing container and mechanically stirred for 5 minutes to form a uniform dispersion, namely, a micro-nanostructured hydrophobic coating.

[0088] Step S3: Application of coating

[0089] Use a spray gun to spray the micro-nanostructure hydrophobic coating prepared in step S2 onto the surface pretreated 304 stainless steel metal substrate prepared in step S1, and control the spraying amount to 20 g / m 2 The coated metal substrate was naturally dried, and then placed in an oven at 65°C for curing for 3 hours, and a self-cleaning coated metal curtain wall panel was obtained after natural cooling.

[0090] Example 6

[0091] Step S1: Surface pretreatment of metal substrate

[0092] Use hydrochloric acid solution to micro-etch the surface of 304 stainless steel substrate. Soak the 304 stainless steel substrate in a hydrochloric acid solution with a mass concentration of 6.0% and ultrasonically oscillate for 120 seconds. Immediately take out the 304 stainless steel substrate and place it in flowing deionized water for preliminary rinsing. Gently shake the substrate to remove the hydrochloric acid solution and other impurities remaining on the surface. Subsequently, place the substrate in an ultrasonic cleaning tank containing deionized water and ultrasonically clean it for 300 seconds. Place the cleaned 304 stainless steel substrate in a hot air drying oven at 120°C for 5 hours until it is completely dry and cool to room temperature.

[0093] The surface of the 304 stainless steel substrate after micro-etching was vacuum magnetron sputtering coating. First, the substrate was fixed in the sputtering device, and the distance between the substrate and the target was kept at 20 cm. The sputtering target was a mixed powder of high-purity nickel powder, high-purity copper powder and high-purity molybdenum silicide powder, with a mass ratio of 100:25:15. Vacuum to 10 -4 Pa, and then introduced argon as the process gas, with the flow rate controlled at 80cm 3 / min, set the sputtering power to 800W, start sputtering and continue for 5 minutes. During the entire sputtering process, closely monitor the stability of process parameters such as vacuum degree, gas flow and sputtering power. After sputtering, take out the coated 304 stainless steel substrate.

[0094] Step S2: Preparation of micro-nanostructure hydrophobic coating

[0095] 1 mol / L tris(hydroxymethyl)aminomethane hydrochloride) solution (Tris-HCl) was added dropwise to an aqueous solution of dopamine with a mass concentration of 0.25%, and the pH of the solution was adjusted to about 9, and then hollow glass microspheres with a particle size of 10±2 μm were added, and mechanical stirring was performed at room temperature for 10 hours. The hollow glass microspheres were then filtered out, washed three times with deionized water, and vacuum dried to obtain dopamine hollow glass microspheres.

[0096] Add dopaminated hollow glass microspheres, polyvinyl pyrrolidone, styrene and deionized water in a mass ratio of 5:1.2:8:100 into a reaction container, heat to 65°C, stir at a high speed of 800 r / min, slowly drop a 1.5% potassium persulfate aqueous solution, and the mass ratio of the potassium persulfate aqueous solution to the deionized water added to the reaction container is 80:100; after the dropwise addition is completed, continue to stir and react for 12 hours, then cool and filter out the solid, wash three times with deionized water, and vacuum dry to obtain polystyrene-dopaminated hollow glass microspheres.

[0097] Polystyrenated dopamine hollow glass microspheres, polydimethylsiloxane and petroleum ether in a mass ratio of 5.5:0.6:100 were added into a mixing container and mechanically stirred for 5 minutes to form a uniform dispersion, i.e., a micro-nanostructured hydrophobic coating.

[0098] Step S3: Application of coating

[0099] Use a spray gun to spray the micro-nanostructure hydrophobic coating prepared in step S2 onto the surface pretreated 304 stainless steel metal substrate prepared in step S1, and control the spraying amount to 30 g / m 2 The coated metal substrate was naturally dried, and then placed in an oven at 65°C for curing for 3 hours, and a self-cleaning coated metal curtain wall panel was obtained after natural cooling.

[0100] Comparative Example 1

[0101] The 304 stainless steel substrate was used directly without pretreatment, and the other operation steps were consistent with those in Example 3.

[0102] Step S1: Preparation of metal substrate

[0103] The prepared 304 stainless steel substrate was directly used in the next process without pretreatment.

[0104] Step S2: Preparation of micro-nanostructure hydrophobic coating

[0105] 1 mol / L tris(hydroxymethyl)aminomethane hydrochloride) solution (Tris-HCl) was added dropwise to an aqueous solution of dopamine with a mass concentration of 0.25%, and the pH of the solution was adjusted to about 9, and then hollow glass microspheres with a particle size of 10±2 μm were added, and mechanical stirring was performed at room temperature for 10 hours. The hollow glass microspheres were then filtered out, washed three times with deionized water, and vacuum dried to obtain dopamine hollow glass microspheres.

[0106] Add dopaminated hollow glass microspheres, polyvinyl pyrrolidone, styrene and deionized water in a mass ratio of 4:1.0:7:100 into a reaction container, heat to 65°C, stir at a high speed of 800 r / min, slowly drop a 1.5% potassium persulfate aqueous solution, and the mass ratio of the potassium persulfate aqueous solution to the deionized water added to the reaction container is 70:100; after the dropwise addition is completed, continue to stir and react for 12 hours, then cool and filter out the solid, wash three times with deionized water, and vacuum dry to obtain polystyrene-dopaminated hollow glass microspheres.

[0107] Polystyrene-doped hollow glass microspheres, polydimethylsiloxane and petroleum ether were added in a mass ratio of 5.0:0.55:100 into a mixing container, and mechanically stirred for 5 minutes to form a uniform dispersion, namely, a micro-nanostructure hydrophobic coating.

[0108] Step S3: Application of coating

[0109] Use a spray gun to spray the micro-nanostructure hydrophobic coating prepared in step S2 onto the 304 stainless steel metal substrate, and control the spraying amount to 20 g / m 2The coated metal substrate was naturally dried, and then placed in an oven at 65°C for curing for 3 hours, and a self-cleaning coated metal curtain wall panel was obtained after natural cooling.

[0110] Comparative Example 2

[0111] In step S1, targets with different ratios are used for magnetron sputtering coating, and other operation steps are consistent with those in Example 3.

[0112] Step S1: Surface pretreatment of metal substrate

[0113] Use hydrochloric acid solution to micro-etch the surface of 304 stainless steel substrate. Soak the 304 stainless steel substrate in a hydrochloric acid solution with a mass concentration of 5.0% and ultrasonically oscillate for 90 seconds. Immediately take out the 304 stainless steel substrate and place it in flowing deionized water for preliminary rinsing. Gently shake the substrate to remove the hydrochloric acid solution and other impurities remaining on the surface. Subsequently, place the substrate in an ultrasonic cleaning tank containing deionized water and ultrasonically clean it for 240 seconds. Place the cleaned 304 stainless steel substrate in a hot air drying oven at 120°C for 5 hours until it is completely dry and cool to room temperature.

[0114] The surface of the 304 stainless steel substrate after micro-etching was vacuum magnetron sputtering coated. First, the substrate was fixed in the sputtering device, and the distance between the substrate and the target was kept at 20cm. The sputtering target was a mixed powder of high-purity nickel powder, high-purity copper powder and high-purity molybdenum silicide powder, with a mass ratio of 100:50:5. The vacuum was evacuated to 10-4Pa, and then argon was introduced as the process gas, and the flow rate was controlled at 70cm 3 / min, set the sputtering power to 700W, start sputtering and continue for 4 minutes. During the entire sputtering process, closely monitor the stability of process parameters such as vacuum degree, gas flow and sputtering power. After sputtering, take out the coated 304 stainless steel substrate.

[0115] Step S2: Preparation of micro-nanostructure hydrophobic coating

[0116] 1 mol / L tris(hydroxymethyl)aminomethane hydrochloride) solution (Tris-HCl) was added dropwise to an aqueous solution of dopamine with a mass concentration of 0.25%, and the pH of the solution was adjusted to about 9, and then hollow glass microspheres with a particle size of 10±2 μm were added, and mechanical stirring was performed at room temperature for 10 hours. The hollow glass microspheres were then filtered out, washed three times with deionized water, and vacuum dried to obtain dopamine hollow glass microspheres.

[0117] Add dopaminated hollow glass microspheres, polyvinyl pyrrolidone, styrene and deionized water in a mass ratio of 4:1.0:7:100 into a reaction container, heat to 65°C, stir at a high speed of 800 r / min, slowly drop a 1.5% potassium persulfate aqueous solution, and the mass ratio of the potassium persulfate aqueous solution to the deionized water added to the reaction container is 70:100; after the dropwise addition is completed, continue to stir and react for 12 hours, then cool and filter out the solid, wash three times with deionized water, and vacuum dry to obtain polystyrene-dopaminated hollow glass microspheres.

[0118] Polystyrene-doped hollow glass microspheres, polydimethylsiloxane and petroleum ether were added in a mass ratio of 5.0:0.55:100 into a mixing container, and mechanically stirred for 5 minutes to form a uniform dispersion, namely, a micro-nanostructure hydrophobic coating.

[0119] Step S3: Application of coating

[0120] Use a spray gun to spray the micro-nanostructure hydrophobic coating prepared in step S2 onto the surface pretreated 304 stainless steel metal substrate prepared in step S1, and control the spraying amount to 20 g / m 2 The coated metal substrate was naturally dried, and then placed in an oven at 65°C for curing for 3 hours, and a self-cleaning coated metal curtain wall panel was obtained after natural cooling.

[0121] Comparative Example 3

[0122] In step S1, targets with different ratios are used for magnetron sputtering coating, and other operation steps are consistent with those in Example 3.

[0123] Step S1: Surface pretreatment of metal substrate

[0124] Use hydrochloric acid solution to micro-etch the surface of 304 stainless steel substrate. Soak the 304 stainless steel substrate in a hydrochloric acid solution with a mass concentration of 5.0% and ultrasonically oscillate for 90 seconds. Immediately take out the 304 stainless steel substrate and place it in flowing deionized water for preliminary rinsing. Gently shake the substrate to remove the hydrochloric acid solution and other impurities remaining on the surface. Subsequently, place the substrate in an ultrasonic cleaning tank containing deionized water and ultrasonically clean it for 240 seconds. Place the cleaned 304 stainless steel substrate in a hot air drying oven at 120°C for 5 hours until it is completely dry and cool to room temperature.

[0125] The surface of the 304 stainless steel substrate after micro-etching was vacuum magnetron sputtering coating. First, the substrate was fixed in the sputtering device, and the distance between the substrate and the target was kept at 20 cm. The sputtering target was a mixed powder of high-purity nickel powder, high-purity copper powder and high-purity molybdenum silicide powder, with a mass ratio of 100:10:40. Vacuum to 10 -4Pa, and then introduced argon as the process gas, with the flow rate controlled at 70cm 3 / min, set the sputtering power to 700W, start sputtering and continue for 4 minutes. During the entire sputtering process, closely monitor the stability of process parameters such as vacuum degree, gas flow and sputtering power. After sputtering, take out the coated 304 stainless steel substrate.

[0126] Step S2: Preparation of micro-nanostructure hydrophobic coating

[0127] 1 mol / L tris(hydroxymethyl)aminomethane hydrochloride) solution (Tris-HCl) was added dropwise to an aqueous solution of dopamine with a mass concentration of 0.25%, and the pH of the solution was adjusted to about 9, and then hollow glass microspheres with a particle size of 10±2 μm were added, and mechanical stirring was performed at room temperature for 10 hours. The hollow glass microspheres were then filtered out, washed three times with deionized water, and vacuum dried to obtain dopamine hollow glass microspheres.

[0128] Add dopaminated hollow glass microspheres, polyvinyl pyrrolidone, styrene and deionized water in a mass ratio of 4:1.0:7:100 into a reaction container, heat to 65°C, stir at a high speed of 800 r / min, slowly drop a 1.5% potassium persulfate aqueous solution, and the mass ratio of the potassium persulfate aqueous solution to the deionized water added to the reaction container is 70:100; after the dropwise addition is completed, continue to stir and react for 12 hours, then cool and filter out the solid, wash three times with deionized water, and vacuum dry to obtain polystyrene-dopaminated hollow glass microspheres.

[0129] Polystyrene-doped hollow glass microspheres, polydimethylsiloxane and petroleum ether were added in a mass ratio of 5.0:0.55:100 into a mixing container, and mechanically stirred for 5 minutes to form a uniform dispersion, namely, a micro-nanostructure hydrophobic coating.

[0130] Step S3: Application of coating

[0131] Use a spray gun to spray the micro-nanostructure hydrophobic coating prepared in step S2 onto the surface pretreated 304 stainless steel metal substrate prepared in step S1, and control the spraying amount to 20 g / m 2 The coated metal substrate was naturally dried, and then placed in an oven at 65°C for curing for 3 hours, and a self-cleaning coated metal curtain wall panel was obtained after natural cooling.

[0132] Comparative Example 4

[0133] In step S2, the hollow glass microspheres are directly polystyrenated without being dopaminated, and the other operation steps are consistent with those in Example 3.

[0134] Step S1: Surface pretreatment of metal substrate

[0135] Use hydrochloric acid solution to micro-etch the surface of 304 stainless steel substrate. Soak the 304 stainless steel substrate in a hydrochloric acid solution with a mass concentration of 5.0% and ultrasonically oscillate for 90 seconds. Immediately take out the 304 stainless steel substrate and place it in flowing deionized water for preliminary rinsing. Gently shake the substrate to remove the hydrochloric acid solution and other impurities remaining on the surface. Subsequently, place the substrate in an ultrasonic cleaning tank containing deionized water and ultrasonically clean it for 240 seconds. Place the cleaned 304 stainless steel substrate in a hot air drying oven at 120°C for 5 hours until it is completely dry and cool to room temperature.

[0136] The surface of the 304 stainless steel substrate after micro-corrosion treatment was vacuum magnetron sputtering coated. First, the substrate was fixed in the sputtering device, and the distance between the substrate and the target was kept at 20 cm. The sputtering target was a mixed powder of high-purity nickel powder, high-purity copper powder and high-purity molybdenum silicide powder, with a mass ratio of 100:20:12. The vacuum was evacuated to 10-4Pa, and then argon was introduced as the process gas, and the flow rate was controlled at 70cm 3 / min, set the sputtering power to 700W, start sputtering and continue for 4 minutes. During the entire sputtering process, closely monitor the stability of process parameters such as vacuum degree, gas flow and sputtering power. After sputtering, take out the coated 304 stainless steel substrate.

[0137] Step S2: Preparation of micro-nanostructure hydrophobic coating

[0138] Hollow glass microspheres with a particle size of 10±2 μm, polyvinyl pyrrolidone, styrene and deionized water in a mass ratio of 4:1.0:7:100 were added to a reaction container, heated to 65°C, stirred at a high speed of 800 r / min, and a potassium persulfate aqueous solution with a mass concentration of 1.5% was slowly added dropwise, and the mass ratio of the potassium persulfate aqueous solution to the deionized water added to the reaction container was 70:100; after the addition was completed, stirring and reacting were continued for 12 hours, and then the solids were cooled and filtered out, washed three times with deionized water, and vacuum dried to obtain polystyrene hollow glass microspheres.

[0139] Polystyrene-modified hollow glass microspheres, polydimethylsiloxane and petroleum ether in a mass ratio of 5.0:0.55:100 were added to a mixing container and mechanically stirred for 5 minutes to form a uniform dispersion, i.e., a hydrophobic coating.

[0140] Step S3: Application of coating

[0141] Use a spray gun to spray the micro-nanostructure hydrophobic coating prepared in step S2 onto the surface pretreated 304 stainless steel metal substrate prepared in step S1, and control the spraying amount to 20 g / m 2 The coated metal substrate was naturally dried, and then placed in an oven at 65°C for curing for 3 hours, and a self-cleaning coated metal curtain wall panel was obtained after natural cooling.

[0142] Comparative Example 5

[0143] In step S2, the hollow glass microspheres are dopaminized but not polystyrenized, and the other operation steps are consistent with those in Example 3.

[0144] Step S1: Surface pretreatment of metal substrate

[0145] Use hydrochloric acid solution to micro-etch the surface of 304 stainless steel substrate. Soak the 304 stainless steel substrate in a hydrochloric acid solution with a mass concentration of 5.0% and ultrasonically oscillate for 90 seconds. Immediately take out the 304 stainless steel substrate and place it in flowing deionized water for preliminary rinsing. Gently shake the substrate to remove the hydrochloric acid solution and other impurities remaining on the surface. Subsequently, place the substrate in an ultrasonic cleaning tank containing deionized water and ultrasonically clean it for 240 seconds. Place the cleaned 304 stainless steel substrate in a hot air drying oven at 120°C for 5 hours until it is completely dry and cool to room temperature.

[0146] The surface of the 304 stainless steel substrate after micro-corrosion treatment was vacuum magnetron sputtering coated. First, the substrate was fixed in the sputtering device, and the distance between the substrate and the target was kept at 20 cm. The sputtering target was a mixed powder of high-purity nickel powder, high-purity copper powder and high-purity molybdenum silicide powder, with a mass ratio of 100:20:12. The vacuum was evacuated to 10-4Pa, and then argon was introduced as the process gas, and the flow rate was controlled at 70cm 3 / min, set the sputtering power to 700W, start sputtering and continue for 4 minutes. During the entire sputtering process, closely monitor the stability of process parameters such as vacuum degree, gas flow and sputtering power. After sputtering, take out the coated 304 stainless steel substrate.

[0147] Step S2: Preparation of micro-nanostructure hydrophobic coating

[0148] 1 mol / L tris(hydroxymethyl)aminomethane hydrochloride) solution (Tris-HCl) was added dropwise to an aqueous solution of dopamine with a mass concentration of 0.25%, and the pH of the solution was adjusted to about 9, and then hollow glass microspheres with a particle size of 10±2 μm were added, and mechanical stirring was performed at room temperature for 10 hours. The hollow glass microspheres were then filtered out, washed three times with deionized water, and vacuum dried to obtain dopamine hollow glass microspheres.

[0149] Dopaminated hollow glass microspheres, polydimethylsiloxane and petroleum ether were added in a mass ratio of 5.0:0.55:100 into a mixing container, and mechanically stirred for 5 minutes to form a uniform dispersion, i.e., a hydrophobic coating.

[0150] Step S3: Application of coating

[0151] Use a spray gun to spray the micro-nanostructure hydrophobic coating prepared in step S2 onto the surface pretreated 304 stainless steel metal substrate prepared in step S1, and control the spraying amount to 20 g / m 2 The coated metal substrate was naturally dried, and then placed in an oven at 65°C for curing for 3 hours, and a self-cleaning coated metal curtain wall panel was obtained after natural cooling.

[0152] Comparative Example 6

[0153] In step S2, large-sized hollow glass microspheres are selected, and the other operation steps are consistent with those in Example 3.

[0154] Step S1: Surface pretreatment of metal substrate

[0155] Use hydrochloric acid solution to micro-etch the surface of 304 stainless steel substrate. Soak the 304 stainless steel substrate in a hydrochloric acid solution with a mass concentration of 5.0% and ultrasonically oscillate for 90 seconds. Immediately take out the 304 stainless steel substrate and place it in flowing deionized water for preliminary rinsing. Gently shake the substrate to remove the hydrochloric acid solution and other impurities remaining on the surface. Subsequently, place the substrate in an ultrasonic cleaning tank containing deionized water and ultrasonically clean it for 240 seconds. Place the cleaned 304 stainless steel substrate in a hot air drying oven at 120°C for 5 hours until it is completely dry and cool to room temperature.

[0156] The surface of the 304 stainless steel substrate after micro-corrosion treatment was vacuum magnetron sputtering coated. First, the substrate was fixed in the sputtering device, and the distance between the substrate and the target was kept at 20 cm. The sputtering target was a mixed powder of high-purity nickel powder, high-purity copper powder and high-purity molybdenum silicide powder, with a mass ratio of 100:20:12. The vacuum was evacuated to 10-4Pa, and then argon was introduced as the process gas, and the flow rate was controlled at 70cm 3 / min, set the sputtering power to 700W, start sputtering and continue for 4 minutes. During the entire sputtering process, closely monitor the stability of process parameters such as vacuum degree, gas flow and sputtering power. After sputtering, take out the coated 304 stainless steel substrate.

[0157] Step S2: Preparation of micro-nanostructure hydrophobic coating

[0158] 1 mol / L tris-hydroxymethylaminomethane hydrochloride (Tris-HCl) solution was added dropwise to an aqueous solution of dopamine with a mass concentration of 0.25%, and the pH of the solution was adjusted to about 9, and then hollow glass microspheres with a particle size of 80±5 μm were added, and mechanical stirring was performed at room temperature for 10 hours. The hollow glass microspheres were then filtered out, washed three times with deionized water, and vacuum dried to obtain dopamine hollow glass microspheres.

[0159] Add dopaminated hollow glass microspheres, polyvinyl pyrrolidone, styrene and deionized water in a mass ratio of 4:1.0:7:100 into a reaction container, heat to 65°C, stir at a high speed of 800 r / min, slowly drop a 1.5% potassium persulfate aqueous solution, and the mass ratio of the potassium persulfate aqueous solution to the deionized water added to the reaction container is 70:100; after the dropwise addition is completed, continue to stir and react for 12 hours, then cool and filter out the solid, wash three times with deionized water, and vacuum dry to obtain polystyrene-dopaminated hollow glass microspheres.

[0160] Polystyrenated dopamine hollow glass microspheres, polydimethylsiloxane and petroleum ether in a mass ratio of 5.0:0.55:100 were added to a mixing container and mechanically stirred for 5 minutes to form a uniform dispersion, i.e., a hydrophobic coating.

[0161] Step S3: Application of coating

[0162] Use a spray gun to spray the micro-nanostructure hydrophobic coating prepared in step S2 onto the surface pretreated 304 stainless steel metal substrate prepared in step S1, and control the spraying amount to 20 g / m 2 The coated metal substrate was naturally dried, and then placed in an oven at 65°C for curing for 3 hours, and a self-cleaning coated metal curtain wall panel was obtained after natural cooling.

[0163] For each sample prepared in the above-mentioned embodiment and comparative example, the initial water contact angle was tested using a CA200S contact angle tester, and then the wear resistance and stability of the surface coating of the curtain wall panel were tested by grinding 200 times with a 250g weight according to the rotating rubber grinding wheel method specified in the GB / T 1768-2006 standard, and the weight loss of the sample was recorded. After grinding, the water contact angle was tested again using the CA200S contact angle tester, which was recorded as the secondary water contact angle. The test results are shown in Table 1.

[0164] Table 1 Test results

[0165]

[0166] The results show that the samples prepared in Examples 1 to 6 all exhibit excellent hydrophobic properties, with an initial water contact angle of 156° to 159°. After the polishing test, only a slight weight loss occurs and the water contact angle only decreases slightly. The coating on the surface of the substrate has extremely strong stability and durability, and can maintain excellent hydrophobic properties in outdoor use environments such as strong winds and blowing sand.

[0167] In Comparative Example 1, the 304 stainless steel substrate was used directly without pretreatment. In Comparative Examples 2 and 3, different ratios of target materials were used for magnetron sputtering coating. Although the prepared samples had a large initial water contact angle and showed excellent hydrophobicity in the initial test, the adhesion and stability of this coating on the surface of the 304 stainless steel substrate were poor. After the polishing test, the coating showed obvious wear and shedding, resulting in a significant decrease in the secondary water contact angle and a significant reduction in the hydrophobic performance.

[0168] In Comparative Example 4, the hollow glass microspheres were directly polystyrenated without being dopaminated. In Comparative Example 5, the hollow glass microspheres were dopaminated but not polystyrenated. The initial water contact angle of the prepared samples was significantly reduced, the hydrophobicity was significantly reduced, and the durability of the coating was also reduced to a certain extent.

[0169] In Comparative Example 6, large-sized hollow glass microspheres were selected, and the initial water contact angle of the prepared sample was significantly reduced, the hydrophobicity was significantly reduced, and the durability of the coating was also significantly weakened.

[0170] The above embodiments are exemplary, and their purpose is to illustrate the technical concept and features of the present invention so that people familiar with the technology in this field can understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a self-cleaning coated metal curtain wall panel, characterized in that: The following steps are involved: Step S1: Surface pretreatment of metal substrate The method comprises using an acid to micro-etch the surface of a metal substrate and attaching a sputtering layer to the surface of the micro-etched metal substrate by magnetron sputtering; Step S2: Preparation of micro-nanostructure hydrophobic coating The method comprises the steps of sequentially performing dopamination and polystyrene on the surface of hollow glass microspheres to form a polystyrene hydrophobic layer with a micro-nano structure on the surface of the hollow glass microspheres; and then mixing the polystyrene-treated dopamination hollow glass microspheres, polydimethylsiloxane and petroleum ether to obtain a hydrophobic coating; Step S3: Application of coating The hydrophobic coating prepared in step S2 is coated on the metal substrate prepared in step S1 and subjected to surface pretreatment, and heated and cured to obtain the self-cleaning coated metal curtain wall panel.

2. The method for preparing the self-cleaning coated metal curtain wall panel according to claim 1, characterized in that: In step S1, the micro-corrosion of the metal substrate is to use a hydrochloric acid solution to micro-corrode the surface of the stainless steel substrate. The stainless steel substrate is immersed in a hydrochloric acid solution with a mass concentration of 3.0% to 6.0%, ultrasonically oscillated for 60s to 120s, and then cleaned to remove the residual acid on the surface, and dried to obtain a micro-corroded stainless steel substrate.

3. The method for preparing the self-cleaning coated metal curtain wall panel according to claim 2, characterized in that: In step S1, the sputtering layer is formed by the following steps: fixing the stainless steel substrate after micro-corrosion treatment in a sputtering device for magnetron sputtering coating, the distance between the substrate and the target is 20±1cm, and the sputtering target is a mixed powder of high-purity nickel powder, high-purity copper powder and high-purity molybdenum silicide powder, and the mass ratio of the three is 100:(15~25):(10~15); vacuuming to 10 −3 Pa~10 −5 Pa, argon is the process gas, and the flow rate is 50cm 3 / min~80cm 3 / min, the sputtering power is 600W~800W, and the sputtering lasts for 3min~5min.

4. The method for preparing the self-cleaning coated metal curtain wall panel according to claim 1, characterized in that: In step S2, dopamine hollow glass microspheres are prepared by the following steps: 1 mol / L tris(hydroxymethyl)aminomethane hydrochloride) solution is added dropwise to an aqueous solution of dopamine with a mass concentration of 0.25%, the pH of the solution is adjusted to 9, and then hollow glass microspheres with a particle size of 10±2 μm are added, mechanically stirred at room temperature for more than 10 hours, and dopamine hollow glass microspheres are obtained by filtering, washing, and drying.

5. The method for preparing the self-cleaning coated metal curtain wall panel according to claim 4, characterized in that: In step S2, polystyrene-doped hollow glass microspheres are prepared by the following steps: adding dopamine-doped hollow glass microspheres, polyvinyl pyrrolidone, styrene and deionized water in a mass ratio of (3-5):(0.8-1.2):(5-8):100 to a reaction container, heating to 65° C., slowly dripping a 1.5% potassium persulfate aqueous solution under high-speed stirring, wherein the mass ratio of the potassium persulfate aqueous solution to the deionized water added to the reaction container is (60-80):100; after the dripping is completed, stirring is continued and the reaction is continued for more than 12 hours, and after cooling, the polystyrene-doped hollow glass microspheres are obtained by filtering, washing and drying.

6. The method for preparing the self-cleaning coated metal curtain wall panel according to claim 5, characterized in that: In step S2, the following steps are performed to prepare: polystyrene-doped hollow glass microspheres, polydimethylsiloxane and petroleum ether in a mass ratio of (4.0-5.5):(0.4-0.6):100 are added into a mixing container, and stirred to form a uniform dispersion, i.e., a micro-nanostructured hydrophobic coating.

7. The method for preparing the self-cleaning coated metal curtain wall panel according to claim 1, characterized in that: In step S3, the hydrophobic coating prepared in step S2 is sprayed on the metal substrate prepared in step S1 and subjected to surface pretreatment using a spray gun, dried naturally, and then heated and cured to obtain a self-cleaning coated metal curtain wall panel.

8. The method for preparing the self-cleaning coated metal curtain wall panel according to claim 1, characterized in that: In step S3, the controlled spraying amount of the hydrophobic coating is 15 g / m 2 ~30g / m 2 After natural drying, place in a 65°C oven to cure for 3 hours to form a self-cleaning coated metal curtain wall panel.

9. The method for preparing the self-cleaning coated metal curtain wall panel according to any one of claims 1 to 8, characterized in that: The metal substrate is a 304 stainless steel metal substrate.

10. A self-cleaning coated metal curtain wall panel, characterized in that: Prepared according to the preparation method according to any one of claims 1 to 9.

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