Glass self-cleaning coating liquid as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of glass surface treatment, and particularly relates to glass self-cleaning coating liquid as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing silicate ester, a diluent, deionized water and a pH regulator, and stirring and reacting at normal temperature to obtain acidic silica sol; mixing silicate ester and a diluent to prepare a silicate ester solution; mixing deionized water, a diluent, a particle size regulator and a catalyst to prepare an alkaline catalytic base solution; dropwise adding the silicate ester solution into the alkaline catalytic base solution in a stirring state, and reacting at normal temperature to obtain alkaline particle silica sol; dropwise adding the acidic silica sol into the alkaline particle silica sol, stirring and reacting at normal temperature, and standing and aging to obtain composite silica sol; and diluting the composite silica sol with a diluent, and adding a volatilization inhibitor to obtain the glass self-cleaning coating liquid.

Description

Technical Field

[0001] This invention belongs to the field of glass surface treatment technology, and particularly relates to a glass self-cleaning coating liquid, its preparation method and application. Background Technology

[0002] With the transformation of the global energy structure, photovoltaic power generation technology and the application of modern building curtain walls are becoming increasingly widespread. In the actual operation of photovoltaic modules, the cover glass, as the essential channel for light, directly determines the photoelectric conversion efficiency through its light transmittance. However, photovoltaic glass is exposed to the outdoor environment for a long time, and its surface is prone to accumulating dust, bird droppings, and industrial pollutants due to electrostatic adsorption or natural sedimentation. Studies have shown that dust accumulation not only significantly reduces the light transmittance of the glass, leading to a substantial decrease in power generation efficiency, but may also cause a "hot spot effect" in areas with sparse rainfall, damaging the modules. Similarly, for high-rise building curtain wall glass, surface contamination not only affects the building's aesthetics and lighting, but also presents challenges due to the difficulty, high cost, and safety risks associated with high-altitude cleaning operations. Therefore, developing a glass coating liquid that combines antireflective (anti-reflective) and self-cleaning functions, utilizing natural rainfall or simple rinsing to keep the glass surface clean, has become a research hotspot in the fields of photovoltaic operation and maintenance and building materials.

[0003] Current glass self-cleaning antireflective technologies mainly fall into two categories: hydrophobic and hydrophilic. Hydrophobic coatings (such as CN118126545A) typically utilize the "lotus effect," constructing micro-nano rough structures and modifying them with low surface energy materials (such as fluorosilanes or organic resins) to allow water droplets to roll off and carry away dust. However, the large amount of organic hydrophobic components in these coatings has poor UV resistance and is prone to decomposition and failure after long-term outdoor exposure; moreover, once the hydrophobic properties decline, rainwater easily forms watermarks on the surface, which actually reduces light transmittance. Photocatalytic coatings (mainly based on TiO2) can degrade organic matter, but their high refractive index limits their contribution to antireflection and they cannot effectively remove inorganic mineral dust. Another mainstream technology is the superhydrophilic antireflective film based on the stacking of silica nanoparticles (such as the hollow nanosphere technology mentioned in CN118930069A or CN105754381A), which uses nanoparticles to form a porous structure on the glass surface to reduce the refractive index and achieve superhydrophilic spreading. While this particle-stacking structure provides excellent antireflective properties, the connections between particles and between particles and the substrate rely primarily on point-contact physical adsorption or weak chemical bonds, lacking a continuous and dense film-forming framework. This results in low mechanical strength, poor adhesion, and insufficient abrasion resistance, making the film highly susceptible to powdering and detachment during transportation, installation, or in harsh weather conditions. Furthermore, traditional sol-gel methods often require high-temperature sintering (tempering) to improve film strength, which is not only energy-intensive but also difficult to meet the room-temperature application requirements of tempered glass or heat-sensitive substrates.

[0004] Therefore, a pressing technical challenge in existing technologies is how to overcome the shortcomings of low mechanical strength and poor adhesion in simple nanoparticle stacked films without relying on high-temperature sintering. The goal is to prepare a glass coating solution that maintains the high anti-reflection and superhydrophilic self-cleaning properties of the nanostructure while curing at room temperature to form a glass coating with excellent weather resistance, wear resistance, and strong substrate adhesion. Specifically, optimizing the preparation process and sol microstructure to fundamentally solve the problem of loose and easily detached films while ensuring their porous and high light transmittance is a key issue that urgently needs to be addressed by those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a glass self-cleaning coating liquid, its preparation method, and its application.

[0006] Firstly, a method for preparing a self-cleaning glass coating solution, employing the following technical solution: A method for preparing a glass self-cleaning coating solution includes the following steps: Step (1): Mix silicate ester, diluent, deionized water and pH adjuster, and stir at room temperature to obtain acidic silica sol; Step (2): Prepare a silicate solution by mixing silicate ester and diluent; prepare an alkaline catalytic base solution by mixing deionized water, diluent, particle size modifier and catalyst; add the silicate ester solution dropwise to the alkaline catalytic base solution under stirring, and react at room temperature to obtain alkaline particulate silica sol; Step (3): The acidic silica sol obtained in step (1) is added dropwise to the alkaline particulate silica sol obtained in step (2), and after stirring and reacting at room temperature, it is allowed to stand and age to obtain composite silica sol. Step (4): Dilute the composite silica sol obtained in step (3) with a diluent and add a volatilization inhibitor to obtain the glass self-cleaning coating solution.

[0007] Further, in step (1), the mass ratio of silicate ester, diluent, deionized water and pH adjuster is 20:40~60:8~12:0.4~0.6, and the reaction is carried out at room temperature with stirring for 3h~5h.

[0008] Further, in step (2), the mass ratio of silicate ester to diluent in the silicate ester solution is 15~25:25~35; the mass ratio of deionized water, diluent, particle size regulator and catalyst in the alkaline catalytic base liquid is 20~30:20~30:0.02~0.08:0.4~0.8; the silicate ester solution is added to the alkaline catalytic base liquid at a rate of 1~2 drops per second; and the reaction is carried out at room temperature with stirring for 3~5 hours.

[0009] Further, in step (3), the mass ratio of the acidic catalytic silica sol to the alkaline particulate silica sol is 1:3~7, the acidic silica sol is added to the alkaline particulate silica sol for 1~2 hours, stirring is continued for 1.5 hours~2.5 hours, and the mixture is allowed to stand for 22 hours~26 hours.

[0010] Further, the silicate ester is selected from at least one of tetraethyl orthosilicate, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, dimethyldiethoxysilane, and diethyltriethoxysilane; The diluent is selected from ethanol or isopropanol; The pH adjuster is selected from hydrochloric acid or nitric acid; The catalyst is selected from one of diethanolamine, dimethylethanolamine, dimethylformamide, and ammonia water; The particle size regulator is polyethylene glycol with a molecular weight of 400-800; The volatile inhibitor is selected from one of ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol butyl ether, and diethylene glycol butyl ether.

[0011] Further, in step (4), the solid content of the diluted composite silica sol is 3-4%, and the amount of the volatile inhibitor added is 5-7% of the total mass of the solution.

[0012] Furthermore, nano-titanium dioxide or titanium sol is also added to the coating solution.

[0013] Furthermore, the coating solution also contains antimony-doped tin dioxide powder, phosphorus-doped tin dioxide sol, or antimony-doped tin dioxide sol.

[0014] Secondly, a self-cleaning glass coating solution adopts the following technical solution: A glass self-cleaning coating solution is prepared by the above-described preparation method.

[0015] Thirdly, the application of a self-cleaning glass coating solution employs the following technical solution: The application of a self-cleaning glass coating liquid in photovoltaic glass or building curtain wall glass involves coating the self-cleaning glass coating liquid onto the surface of photovoltaic glass or building curtain wall glass, curing it at room temperature or tempering it along with the glass, and forming a nano-composite coating with a mesh structure encapsulating spherical particles on the glass surface.

[0016] The beneficial effects of this invention are: This invention provides a method for preparing a self-cleaning glass coating solution. By controlling a dual acid-base catalytic system and a specific order and ratio of liquid addition, silicate oligomers rich in linear or branched network structures, generated by hydrolysis under acidic conditions, are controllably introduced into a system of spherical silica particles grown under alkaline conditions. During the reaction and aging process, the network silica chains in the acidic sol undergo cross-linking and grafting on the surface and between the spherical particles, constructing in situ a composite microstructure in which the network structure encapsulates the spherical particles. This structure retains the nanoscale roughness and porosity characteristics formed by the accumulation of spherical particles, effectively reducing the refractive index of the film and imparting high anti-reflective properties to the glass. On the other hand, the network structure, as a continuous inorganic binder phase, transforms the point contacts between particles and between particles and the substrate into more stable surface contacts or interpenetrating network structures, significantly enhancing the cohesive strength of the film and its adhesion to the glass substrate. Therefore, the coating solution prepared by this method can form a functional coating with superhydrophilicity (contact angle <5°), high light transmittance and excellent wear and weather resistance under room temperature curing conditions. This overcomes the defects of traditional nanoparticle stacked film layers that require high temperature sintering to achieve wear resistance or have poor adhesion and easy peeling at room temperature, and achieves synergistic improvement of the optical and mechanical properties of the coating. Attached Figure Description

[0017] Figure 1 This is a surface morphology diagram of the film layer formed by curing in Application Example 1 of the present invention. Detailed Implementation

[0018] The following detailed description, in conjunction with embodiments, provides a further specific account of the glass self-cleaning coating solution, its preparation method, and its application according to the present invention. For the sake of simplicity, this document cannot exhaustively list all alternative technical features and implementation schemes included in the present invention. Therefore, those skilled in the art should understand that any technical feature and implementation scheme within these embodiments does not limit the scope of protection of the present invention. The scope of protection includes all alternative technical features and implementation schemes adopted by those skilled in the art without inventive effort. Specifically, any implementation scheme obtained by replacing any technical feature in the present invention or by combining any two or more technical features provided by the present invention should be within the scope of protection of the present invention. Where specific techniques and conditions are not specified in the embodiments, they are performed according to the techniques and conditions described in the literature in the art or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0019] The "tennis ball" structure described in this invention, under a scanning electron microscope (SEM), appears as follows: spherical silica particles are uniformly distributed, and the particles are not simply physically stacked together, but are bridged and coated by an amorphous linear or branched silica network (i.e., a "net" structure). This structure typically exhibits a monodisperse distribution with a main peak of 50-70 nm in particle size distribution tests, but under high-magnification transmission electron microscopy (TEM), a gel coating layer of approximately 2-5 nm thickness can be observed on the particle surface.

[0020] Example Example 1 This embodiment 1 provides a method for preparing a glass self-cleaning coating solution, the specific steps of which are as follows: Step (1), Preparation of acidic silica sol: Add 20g of tetraethyl orthosilicate, 40g of anhydrous ethanol and 0.4g of 0.1mol / L hydrochloric acid to a 150mL Erlenmeyer flask equipped with a magnetic stirrer. Add 9g of deionized water while stirring, and continue stirring at room temperature for 4h to obtain acidic silica sol, which is then set aside for later use.

[0021] Step (2), preparation of alkaline particulate silica sol: First, add 24.5g of anhydrous ethanol, 25g of deionized water, 0.06g of polyethylene glycol with a molecular weight of 400 and 0.44g of diethanolamine to a 250mL Erlenmeyer flask equipped with a magnetic stirrer, mix well to prepare an alkaline catalytic base solution, and install a constant pressure funnel above the flask. Second, add 20g of tetraethyl orthosilicate and 30g of anhydrous ethanol to a beaker, stir well with a glass rod to prepare a silicate ester solution, and transfer the silicate ester solution to the aforementioned constant pressure funnel. Finally, control the dropping rate to 1 drop / second, and add the silicate ester solution dropwise to the alkaline catalytic base solution under stirring. After the addition is complete, continue stirring the reaction at room temperature for 4 hours to obtain alkaline particulate silica sol.

[0022] Step (3), preparation of composite silica sol: Transfer 20g of the acidic silica sol prepared in step (1) into a constant pressure funnel, control the dropping time, and add it uniformly to the alkaline particulate silica sol (total mass about 100g) obtained in step (2) within 1.5h. After the dropping is completed, continue to stir the reaction at room temperature for 2h, and then let it stand and age for 24h to obtain a composite silica sol with a "tennis ball" microstructure.

[0023] Step (4), prepare glass self-cleaning coating solution: dilute the above-mentioned aged composite silica sol with anhydrous ethanol to a solid content of 3.5%, and then add ethylene glycol butyl ether at 5% of the total mass of the solution, and mix evenly to obtain the glass self-cleaning coating solution.

[0024] Example 2 This embodiment 2 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1), Preparation of acidic silica sol: Add 20g of tetraethyl orthosilicate, 60g of anhydrous ethanol and 0.6g of 0.1mol / L nitric acid to a 150mL Erlenmeyer flask equipped with a magnetic stirrer. Add 12g of deionized water while stirring, and continue stirring at room temperature for 4h to obtain acidic silica sol, which is then set aside for later use.

[0025] Step (2), preparation of alkaline particulate silica sol: First, add 20g of anhydrous ethanol, 30g of deionized water, 0.08g of polyethylene glycol with a molecular weight of 800, and 0.8g of 25% ammonia solution to a 250mL Erlenmeyer flask equipped with a magnetic stirrer, mix well to form an alkaline catalytic base solution, and install a constant pressure funnel above the flask. Second, add 25g of tetraethyl orthosilicate and 35g of anhydrous ethanol to a beaker, stir well with a glass rod to prepare a silicate ester solution, and transfer the silicate ester solution to the aforementioned constant pressure funnel. Finally, control the dropping rate to 1~2 seconds / drop, and add the silicate ester solution dropwise to the alkaline catalytic base solution under stirring. After the addition is complete, continue stirring the reaction at room temperature for 4 hours to obtain alkaline particulate silica sol.

[0026] Step (3), preparation of composite silica sol: Transfer 37g of the acidic silica sol prepared in step (1) into a constant pressure funnel, control the dropping time, and add it uniformly to the alkaline particulate silica sol obtained in step (2) (total mass about 110g, control the addition mass ratio to be about 1:3) within 1h. After the dropping is completed, continue to stir the reaction at room temperature for 1.5h, and then let it stand and age for 22h to obtain a composite silica sol with a "tennis ball" microstructure.

[0027] Step (4), prepare glass self-cleaning coating solution: dilute the above-mentioned aged composite silica sol with anhydrous ethanol to a solid content of 4.0%, and then add ethylene glycol ethyl ether at 7% of the total mass of the solution, and mix evenly to obtain the glass self-cleaning coating solution.

[0028] Example 3 This embodiment 3 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1), Preparation of acidic silica sol: 18g of tetraethyl orthosilicate, 2g of methyltriethoxysilane, 50g of isopropanol, and 0.5g of 0.1mol / L hydrochloric acid were added sequentially to a 150mL Erlenmeyer flask equipped with a magnetic stirrer. 10g of deionized water was added while stirring, and the reaction was continued at room temperature for 5 hours to obtain acidic silica sol, which was then allowed to stand for later use.

[0029] Step (2), preparation of alkaline particulate silica sol: First, add 30g isopropanol, 20g deionized water, 0.08g polyethylene glycol with a molecular weight of 600, and 0.4g diethanolamine to a 250mL Erlenmeyer flask equipped with a magnetic stirrer, mix well to prepare an alkaline catalytic base solution, and install a constant pressure funnel above the flask. Second, add 15g tetraethyl orthosilicate and 25g isopropanol to a beaker, stir well with a glass rod to prepare a silicate ester solution, and transfer the silicate ester solution to the aforementioned constant pressure funnel. Finally, control the dropping rate to 1 drop / second, and add the silicate ester solution dropwise to the alkaline catalytic base solution under stirring. After the addition is complete, continue stirring the reaction at room temperature for 5 hours to obtain alkaline particulate silica sol.

[0030] Step (3), preparation of composite silica sol: Transfer 22.5g of the acidic silica sol prepared in step (1) into a constant pressure funnel, control the dropping time, and add it uniformly to the alkaline particulate silica sol obtained in step (2) (total mass about 90g, control the addition mass ratio to be about 1:4) within 1.5h. After the dropping is completed, continue to stir the reaction at room temperature for 2h, and then let it stand and age for 24h to obtain a composite silica sol with a "tennis ball" microstructure.

[0031] Step (4), prepare glass self-cleaning coating solution: dilute the above-mentioned aged composite silica sol with isopropanol to a solid content of 3.5%, and then add ethylene glycol butyl ether at 6% of the total mass of the solution, and mix evenly to obtain the glass self-cleaning coating solution.

[0032] Example 4 This embodiment 4 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1), Preparation of acidic silica sol: Add 20g of tetraethyl orthosilicate, 40g of anhydrous ethanol and 0.4g of 0.1mol / L hydrochloric acid to a 150mL Erlenmeyer flask equipped with a magnetic stirrer. Add 8g of deionized water while stirring, and continue stirring at room temperature for 3 hours to obtain acidic silica sol, which is then set aside for later use.

[0033] Step (2), preparation of alkaline particulate silica sol: First, add 20g of anhydrous ethanol, 30g of deionized water, 0.02g of polyethylene glycol with a molecular weight of 400 and 0.4g of dimethylethanolamine to a 250mL Erlenmeyer flask equipped with a magnetic stirrer, mix well to prepare an alkaline catalytic base solution, and install a constant pressure funnel above the flask. Second, add 15g of tetraethyl orthosilicate and 25g of anhydrous ethanol to a beaker, stir well with a glass rod to prepare a silicate ester solution, and transfer the silicate ester solution to the constant pressure funnel. Finally, control the dropping rate to 2 seconds / drop, and add the silicate ester solution dropwise to the alkaline catalytic base solution under stirring. After the addition is complete, continue stirring the reaction at room temperature for 3 hours to obtain alkaline particulate silica sol.

[0034] Step (3), preparation of composite silica sol: Take 13g of the acidic silica sol prepared in step (1) and place it in a constant pressure funnel. Control the dropping time and add it uniformly to the alkaline particulate silica sol obtained in step (2) (total mass about 90g, controlled addition mass ratio about 1:7) within 2h. After the dropping is completed, continue to stir the reaction at room temperature for 2.5h, and then let it stand and age for 26h to obtain a composite silica sol with a "tennis ball" microstructure.

[0035] Step (4), prepare glass self-cleaning coating solution: dilute the above-mentioned aged composite silica sol with anhydrous ethanol to a solid content of 3.0%, and then add diethylene glycol butyl ether at 5% of the total mass of the solution, and mix evenly to obtain the glass self-cleaning coating solution.

[0036] Example 5 This embodiment 5 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1), Preparation of acidic silica sol: 18g of tetraethyl orthosilicate, 2g of dimethyldiethoxysilane, 45g of anhydrous ethanol, and 0.5g of 0.1mol / L nitric acid were added sequentially to a 150mL Erlenmeyer flask equipped with a magnetic stirrer. 10g of deionized water was added while stirring, and the reaction was continued at room temperature for 4 hours to obtain acidic silica sol, which was then allowed to stand for later use.

[0037] Step (2), preparation of alkaline particulate silica sol: First, add 25g of anhydrous ethanol, 25g of deionized water, 0.05g of polyethylene glycol with a molecular weight of 600 and 0.6g of dimethylformamide to a 250mL Erlenmeyer flask equipped with a magnetic stirrer, mix well to prepare an alkaline catalytic base solution, and install a constant pressure funnel above the flask. Next, add 18g of tetraethyl orthosilicate, 2g of diethyltriethoxysilane and 30g of anhydrous ethanol to a beaker, stir well with a glass rod to prepare a silicate ester solution, and transfer the silicate ester solution to the constant pressure funnel. Finally, control the dropping rate to 1 drop / second, and add the silicate ester solution dropwise to the alkaline catalytic base solution under stirring. After the addition is complete, continue stirring the reaction at room temperature for 4 hours to obtain alkaline particulate silica sol.

[0038] Step (3), preparation of composite silica sol: Take 17g of the acidic silica sol prepared in step (1) and place it in a constant pressure funnel. Control the dropping time and add it uniformly to the alkaline particulate silica sol obtained in step (2) (total mass about 100g, controlled addition mass ratio about 1:6) within 1.5h. After the dropping is completed, continue to stir the reaction at room temperature for 2h, and then let it stand for aging for 24h to obtain a composite silica sol with a "tennis ball" microstructure.

[0039] Step (4), prepare glass self-cleaning coating solution: dilute the above-mentioned aged composite silica sol with anhydrous ethanol to a solid content of 3.2%, and then add ethylene glycol methyl ether at 6% of the total mass of the solution, and mix evenly to obtain the glass self-cleaning coating solution.

[0040] Example 6 This embodiment 6 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1), Preparation of acidic silica sol: 20g of ethyltriethoxysilane, 55g of isopropanol, and 0.55g of 0.1mol / L hydrochloric acid were added sequentially to a 150mL Erlenmeyer flask equipped with a magnetic stirrer. 11g of deionized water was added while stirring, and the reaction was continued to be stirred at room temperature for 4.5h to obtain acidic silica sol, which was then allowed to stand for later use.

[0041] Step (2), preparation of alkaline particulate silica sol: First, add 28g isopropanol, 22g deionized water, 0.04g polyethylene glycol with a molecular weight of 400, and 0.5g diethanolamine to a 250mL Erlenmeyer flask equipped with a magnetic stirrer, mix well to prepare an alkaline catalytic base solution, and install a constant pressure funnel above the flask. Second, add 22g tetraethyl orthosilicate and 28g isopropanol to a beaker, stir well with a glass rod to prepare a silicate ester solution, and transfer the silicate ester solution to the constant pressure funnel. Finally, control the dropping rate to 1~2 seconds / drop, and add the silicate ester solution dropwise to the alkaline catalytic base solution under stirring. After the addition is complete, continue stirring the reaction at room temperature for 3.5h to obtain alkaline particulate silica sol.

[0042] Step (3), preparation of composite silica sol: Transfer 20g of the acidic silica sol prepared in step (1) into a constant pressure funnel, control the dropping time, and add it uniformly to the alkaline particulate silica sol obtained in step (2) (total mass about 100g, control the addition mass ratio to be about 1:5) within 1.8h. After the dropping is completed, continue to stir the reaction at room temperature for 2h, and then let it stand and age for 25h to obtain a composite silica sol with a "tennis ball" microstructure.

[0043] Step (4), prepare glass self-cleaning coating solution: dilute the above-mentioned aged composite silica sol with isopropanol to a solid content of 3.8%, and then add ethylene glycol butyl ether at 5% of the total mass of the solution, and mix evenly to obtain the glass self-cleaning coating solution.

[0044] Example 7 This embodiment 7 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1), Preparation of acidic silica sol: Add 20g of tetraethyl orthosilicate, 40g of anhydrous ethanol and 0.4g of 0.1mol / L hydrochloric acid to a 150mL Erlenmeyer flask equipped with a magnetic stirrer. Add 8g of deionized water while stirring, and continue stirring at room temperature for 4h to obtain acidic silica sol, which is then set aside for later use.

[0045] Step (2), preparation of alkaline particulate silica sol: First, add 24.5g isopropanol, 25g deionized water, 0.07g polyethylene glycol with a molecular weight of 400, and 0.5g diethanolamine to a 250mL Erlenmeyer flask equipped with a magnetic stirrer, mix well to prepare an alkaline catalytic base solution, and install a constant pressure funnel above the flask. Second, add 16g tetraethyl orthosilicate, 4g methyltriethoxysilane, and 30g anhydrous ethanol to a beaker, stir well with a glass rod to prepare a silicate ester solution, and transfer the silicate ester solution to the aforementioned constant pressure funnel. Finally, control the dropping rate to 1 drop / second, and add the silicate ester solution dropwise to the alkaline catalytic base solution under stirring. After the addition is complete, continue stirring the reaction at room temperature for 4 hours to obtain alkaline particulate silica sol.

[0046] Step (3), preparation of composite silica sol: Transfer 15g of the acidic silica sol prepared in step (1) into a constant pressure funnel, control the dropping time, and add it uniformly to the alkaline particulate silica sol obtained in step (2) (total mass about 100g, control the addition mass ratio to be about 1:6.6) within 1.5h. After the dropping is completed, continue to stir the reaction at room temperature for 2h, and then let it stand and age for 24h to obtain a composite silica sol with a "tennis ball" microstructure.

[0047] Step (4), prepare glass self-cleaning coating solution: dilute the above-mentioned aged composite silica sol with anhydrous ethanol to a solid content of 3.0%, and then add ethylene glycol butyl ether at 5% of the total mass of the solution; under stirring conditions, add 0.05 wt.% of nano titanium dioxide (P25 powder), and treat with an ultrasonic disperser for 30 minutes to ensure that the powder is uniformly dispersed without agglomeration, and obtain the glass self-cleaning coating solution.

[0048] Example 8 This embodiment 8 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1), Preparation of acidic silica sol: Add 20g of tetraethyl orthosilicate, 40g of isopropanol, and 0.4g of 0.1mol / L hydrochloric acid to a 150mL Erlenmeyer flask equipped with a magnetic stirrer. Add 8g of deionized water while stirring, and continue stirring at room temperature for 4 hours to obtain acidic silica sol, which is then set aside for later use.

[0049] Step (2), preparation of alkaline particulate silica sol: First, add 24.5g isopropanol, 25g deionized water, 0.07g polyethylene glycol (molecular weight 400), and 0.5g diethanolamine sequentially to a 250mL Erlenmeyer flask equipped with a magnetic stirrer, mix well to prepare an alkaline catalytic base solution, and install a constant pressure funnel above the flask. Second, add 20g tetraethyl orthosilicate and 30g isopropanol sequentially to a beaker, stir evenly with a glass rod to prepare a silicate ester solution, and transfer the silicate ester solution to the aforementioned constant pressure funnel. Finally, control the dropping rate to 1~2 seconds / drop, and add the silicate ester solution dropwise at a uniform rate to the alkaline catalytic base solution under stirring; after the addition is complete, continue stirring the reaction at room temperature for 4 hours to obtain alkaline particulate silica sol.

[0050] Step (3), preparation of composite silica sol: Take 20g of the acidic silica sol prepared in step (1) and place it in a constant pressure funnel. Control the dropping time and add it uniformly to the alkaline particulate silica sol obtained in step (2) (total mass about 100g, controlled addition mass ratio about 1:5) within 1.5h. After the dropping is completed, continue to stir the reaction at room temperature for 2h, and then let it stand and age for 24h to obtain a composite silica sol with a "tennis ball" microstructure.

[0051] Step (4), preparing the glass self-cleaning coating solution: dilute the above-mentioned aged composite silica sol with anhydrous ethanol to a solid content of 3.0%, and then add ethylene glycol butyl ether at 5% of the total mass of the solution; under stirring conditions, add 0.25 wt.% of alcohol-dispersed antimony-doped tin dioxide sol (ATO sol, solid content 20%, solvent is ethanol), stir evenly, and obtain the glass self-cleaning coating solution.

[0052] Comparative Example Comparative Example 1 Comparative Example 1 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1), Preparation of acidic silica sol: Add 20g of tetraethyl orthosilicate, 40g of anhydrous ethanol and 0.4g of 0.1mol / L hydrochloric acid to a 150mL Erlenmeyer flask equipped with a magnetic stirrer. Add 2g of deionized water while stirring, and continue stirring at room temperature for 4h to obtain acidic silica sol, which is then set aside for later use.

[0053] Step (2), preparation of alkaline particulate silica sol: First, add 24.5g of anhydrous ethanol, 25g of deionized water, 0.06g of polyethylene glycol with a molecular weight of 400 and 0.44g of diethanolamine to a 250mL Erlenmeyer flask equipped with a magnetic stirrer, mix well to prepare an alkaline catalytic base solution, and install a constant pressure funnel above the flask. Second, add 20g of tetraethyl orthosilicate and 30g of anhydrous ethanol to a beaker, stir well with a glass rod to prepare a silicate ester solution, and transfer the silicate ester solution to the aforementioned constant pressure funnel. Finally, control the dropping rate to 1 drop / second, and add the silicate ester solution dropwise to the alkaline catalytic base solution under stirring. After the addition is complete, continue stirring the reaction at room temperature for 4 hours to obtain alkaline particulate silica sol.

[0054] Step (3), preparation of composite silica sol: Transfer 20g of the acidic silica sol prepared in step (1) into a constant pressure funnel, control the dropping time, and add it uniformly to the alkaline particulate silica sol (total mass about 100g) obtained in step (2) within 1.5h. After the dropping is completed, continue to stir the reaction at room temperature for 2h, and then let it stand for aging for 24h to obtain composite silica sol.

[0055] Step (4), prepare glass self-cleaning coating solution: dilute the above-mentioned aged composite silica sol with anhydrous ethanol to a solid content of 3.5%, and then add ethylene glycol butyl ether at 5% of the total mass of the solution, and mix evenly to obtain the glass self-cleaning coating solution.

[0056] Comparative Example 2 Comparative Example 2 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1), Preparation of acidic silica sol: Add 20g of tetraethyl orthosilicate, 40g of anhydrous ethanol and 0.4g of 0.1mol / L hydrochloric acid to a 150mL Erlenmeyer flask equipped with a magnetic stirrer. Add 9g of deionized water while stirring, and continue stirring at room temperature for 4h to obtain acidic silica sol, which is then set aside for later use.

[0057] Step (2), preparation of alkaline particulate silica sol: First, add 24.5g of anhydrous ethanol, 25g of deionized water, 0.06g of polyethylene glycol with a molecular weight of 400 and 0.44g of diethanolamine to a 250mL Erlenmeyer flask equipped with a magnetic stirrer, mix well to prepare an alkaline catalytic base solution, and install a constant pressure funnel above the flask. Second, add 20g of tetraethyl orthosilicate and 30g of anhydrous ethanol to a beaker, stir well with a glass rod to prepare a silicate ester solution, and transfer the silicate ester solution to the aforementioned constant pressure funnel. Finally, control the dropping rate to 1 drop / second, and add the silicate ester solution dropwise to the alkaline catalytic base solution under stirring. After the addition is complete, continue stirring the reaction at room temperature for 4 hours to obtain alkaline particulate silica sol.

[0058] Step (3), preparation of composite silica sol: Transfer 60g of the acidic silica sol prepared in step (1) into a constant pressure funnel, control the dropping time, and add it uniformly to the alkaline particulate silica sol (total mass about 100g) obtained in step (2) within 1.5h. After the dropping is completed, continue to stir the reaction at room temperature for 2h, and then let it stand for aging for 24h to obtain composite silica sol.

[0059] Step (4), prepare glass self-cleaning coating solution: dilute the above-mentioned aged composite silica sol with anhydrous ethanol to a solid content of 3.5%, and then add ethylene glycol butyl ether at 5% of the total mass of the solution, and mix evenly to obtain the glass self-cleaning coating solution.

[0060] Comparative Example 3 Comparative Example 3 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1), Preparation of acidic silica sol: Add 20g of tetraethyl orthosilicate, 40g of anhydrous ethanol and 0.4g of 0.1mol / L hydrochloric acid to a 150mL Erlenmeyer flask equipped with a magnetic stirrer. Add 9g of deionized water while stirring, and continue stirring at room temperature for 4h to obtain acidic silica sol, which is then set aside for later use.

[0061] Step (2), preparation of alkaline particulate silica sol: First, add 24.5g of anhydrous ethanol, 25g of deionized water, 0.06g of polyethylene glycol with a molecular weight of 400 and 0.44g of diethanolamine to a 250mL Erlenmeyer flask equipped with a magnetic stirrer, mix well to prepare an alkaline catalytic base solution, and install a constant pressure funnel above the flask. Second, add 20g of tetraethyl orthosilicate and 30g of anhydrous ethanol to a beaker, stir well with a glass rod to prepare a silicate ester solution, and transfer the silicate ester solution to the aforementioned constant pressure funnel. Finally, control the dropping rate to 1 drop / second, and add the silicate ester solution dropwise to the alkaline catalytic base solution under stirring. After the addition is complete, continue stirring the reaction at room temperature for 4 hours to obtain alkaline particulate silica sol.

[0062] Step (3), preparation of composite silica sol: Take 20g of the acidic silica sol prepared in step (1) and quickly pour it into the alkaline particulate silica sol obtained in step (2). After mixing, continue stirring and reacting at room temperature for 2h, and then let it stand and age for 24h to obtain composite silica sol.

[0063] Step (4), prepare glass self-cleaning coating solution: dilute the above-mentioned aged composite silica sol with anhydrous ethanol to a solid content of 3.5%, and then add ethylene glycol butyl ether at 5% of the total mass of the solution, and mix evenly to obtain the glass self-cleaning coating solution.

[0064] Comparative Example 4 Comparative Example 4 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1), Preparation of acidic silica sol: Add 20g of tetraethyl orthosilicate, 40g of anhydrous ethanol and 0.4g of 1.0mol / L acetic acid sequentially to a 150mL Erlenmeyer flask equipped with a magnetic stirrer. Add 9g of deionized water while stirring, and continue stirring at room temperature for 4h to obtain acidic silica sol, which is then set aside for later use.

[0065] Step (2), preparation of alkaline particulate silica sol: First, add 24.5g of anhydrous ethanol, 25g of deionized water, 0.06g of polyethylene glycol with a molecular weight of 400 and 0.44g of diethanolamine to a 250mL Erlenmeyer flask equipped with a magnetic stirrer, mix well to prepare an alkaline catalytic base solution, and install a constant pressure funnel above the flask. Second, add 20g of tetraethyl orthosilicate and 30g of anhydrous ethanol to a beaker, stir well with a glass rod to prepare a silicate ester solution, and transfer the silicate ester solution to the aforementioned constant pressure funnel. Finally, control the dropping rate to 1 drop / second, and add the silicate ester solution dropwise to the alkaline catalytic base solution under stirring. After the addition is complete, continue stirring the reaction at room temperature for 4 hours to obtain alkaline particulate silica sol.

[0066] Step (3), preparation of composite silica sol: Transfer 20g of the acidic silica sol prepared in step (1) into a constant pressure funnel, control the dropping time, and add it uniformly to the alkaline particulate silica sol (total mass about 100g) obtained in step (2) within 1.5h. After the dropping is completed, continue to stir the reaction at room temperature for 2h, and then let it stand for aging for 24h to obtain composite silica sol.

[0067] Step (4), prepare glass self-cleaning coating solution: dilute the above-mentioned aged composite silica sol with anhydrous ethanol to a solid content of 3.5%, and then add ethylene glycol butyl ether at 5% of the total mass of the solution, and mix evenly to obtain the glass self-cleaning coating solution.

[0068] Comparative Example 5 Comparative Example 5 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1), Preparation of acidic silica sol: Add 20g of tetraethyl orthosilicate, 40g of anhydrous ethanol and 0.4g of 0.1mol / L hydrochloric acid to a 150mL Erlenmeyer flask equipped with a magnetic stirrer. Add 9g of deionized water while stirring, and continue stirring at room temperature for 4h to obtain acidic silica sol, which is then set aside for later use.

[0069] Step (2), prepare microsphere dispersion: weigh 50g of commercially available silica microsphere dispersion with a particle size of 50nm (solid content of about 3.5%, dispersion medium is ethanol) and place it in a 250mL Erlenmeyer flask as the base liquid for spherical particles.

[0070] Step (3), preparation of composite silica sol: Take 20g of the acidic silica sol prepared in step (1) and place it in a constant pressure funnel. Control the dropping time and add it uniformly to the microsphere dispersion in step (2) within 1.5h. After the dropping is completed, continue to stir the reaction at room temperature for 2h, and then let it stand for 24h to obtain composite silica sol.

[0071] Step (4), prepare glass self-cleaning coating solution: dilute the above-mentioned aged composite silica sol with anhydrous ethanol to a solid content of 3.5%, and then add ethylene glycol butyl ether at 5% of the total mass of the solution, and mix evenly to obtain the glass self-cleaning coating solution.

[0072] Comparative Example 6 Comparative Example 6 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1), Preparation of acidic silica sol: Add 20g of tetraethyl orthosilicate, 40g of anhydrous ethanol and 0.4g of 0.1mol / L hydrochloric acid to a 150mL Erlenmeyer flask equipped with a magnetic stirrer. Add 9g of deionized water while stirring, and continue stirring at room temperature for 4h to obtain acidic silica sol, which is then set aside for later use.

[0073] Step (2), preparation of alkaline particulate silica sol: First, add 24.5g of anhydrous ethanol, 25g of deionized water, 0.06g of polyethylene glycol with a molecular weight of 400 and 0.44g of diethanolamine to a 250mL Erlenmeyer flask equipped with a magnetic stirrer, mix well to prepare an alkaline catalytic base solution, and install a constant pressure funnel above the flask. Second, add 20g of tetraethyl orthosilicate and 30g of anhydrous ethanol to a beaker, stir well with a glass rod to prepare a silicate ester solution, and transfer the silicate ester solution to the aforementioned constant pressure funnel. Finally, control the dropping rate to 1 drop / second, and add the silicate ester solution dropwise to the alkaline catalytic base solution under stirring. After the addition is complete, continue stirring the reaction at room temperature for 4 hours to obtain alkaline particulate silica sol.

[0074] Step (3), preparation of composite silica sol: 100g of the alkaline particulate silica sol obtained in step (2) is placed in a constant pressure funnel, and the dropping time is controlled. It is added dropwise to 20g of the acidic silica sol prepared in step (1) over 1.5h. After the dropping is completed, the mixture is stirred at room temperature for 2h, and then allowed to stand for 24h to age, thus obtaining composite silica sol.

[0075] Step (4), prepare glass self-cleaning coating solution: dilute the above-mentioned aged composite silica sol with anhydrous ethanol to a solid content of 3.5%, and then add ethylene glycol butyl ether at 5% of the total mass of the solution, and mix evenly to obtain the glass self-cleaning coating solution.

[0076] Comparative Example 7 Comparative Example 7 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1), preparation of alkaline particulate silica sol: First, add 24.5g of anhydrous ethanol, 25g of deionized water, 0.06g of polyethylene glycol with a molecular weight of 400 and 0.44g of diethanolamine to a 250mL Erlenmeyer flask equipped with a magnetic stirrer, mix well to prepare an alkaline catalytic base solution, and install a constant pressure funnel above the flask. Second, add 20g of tetraethyl orthosilicate and 30g of anhydrous ethanol to a beaker, stir well with a glass rod to prepare a silicate ester solution, and transfer the silicate ester solution to the aforementioned constant pressure funnel. Finally, control the dropping rate to 1 drop / second, and add the silicate ester solution dropwise to the alkaline catalytic base solution under stirring. After the addition is complete, continue stirring the reaction at room temperature for 4 hours to obtain alkaline particulate silica sol.

[0077] Step (2), prepare the coating solution precursor: directly take the alkaline particulate silica sol prepared in step (1) and age it for 24 hours.

[0078] Step (3), prepare glass self-cleaning coating solution: dilute the above-mentioned aged silica sol with anhydrous ethanol to a solid content of 3.5%, and then add ethylene glycol butyl ether at 5% of the total mass of the solution, and mix evenly to obtain the glass self-cleaning coating solution.

[0079] Comparative Example 8 Comparative Example 8 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1), Preparation of acidic silica sol: Add 20g of tetraethyl orthosilicate, 40g of anhydrous ethanol and 0.4g of 0.1mol / L hydrochloric acid to a 150mL Erlenmeyer flask equipped with a magnetic stirrer. Add 9g of deionized water while stirring, and continue stirring at room temperature for 4h to obtain acidic silica sol, which is then set aside for later use.

[0080] Step (2), prepare the coating solution precursor: directly take the acidic silica sol prepared in step (1) and age it for 24 hours.

[0081] Step (3), prepare glass self-cleaning coating solution: dilute the above-mentioned aged silica sol with anhydrous ethanol to a solid content of 3.5%, and then add ethylene glycol butyl ether at 5% of the total mass of the solution, and mix evenly to obtain the glass self-cleaning coating solution.

[0082] Comparative Example 9 Comparative Example 9 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1): Add 40g tetraethyl orthosilicate, 70g anhydrous ethanol, 34g deionized water, 0.06g polyethylene glycol 400, 0.4g hydrochloric acid (0.1mol / L) and 0.44g diethanolamine to a 500mL beaker equipped with a magnetic stir bar.

[0083] Step (2): Stir the mixture vigorously at room temperature for 30 minutes and let it stand for 24 hours to age.

[0084] Step (3): Dilute the above liquid with anhydrous ethanol to a solid content of 3.5%, and then add ethylene glycol butyl ether at 5% of the total mass of the solution. Mix well to obtain the glass self-cleaning coating solution.

[0085] Comparative Example 10 Comparative Example 10 provides a glass self-cleaning coating solution and its preparation method, the specific steps of which are as follows: Step (1), Preparation of acidic silica sol: Add 20g of tetraethyl orthosilicate, 40g of anhydrous ethanol and 0.4g of 0.1mol / L hydrochloric acid to a 150mL Erlenmeyer flask equipped with a magnetic stirrer. Add 9g of deionized water while stirring, and continue stirring at room temperature for 4h to obtain acidic silica sol, which is then set aside for later use.

[0086] Step (2), preparation of alkaline particulate silica sol: First, add 24.5g of anhydrous ethanol, 25g of deionized water, 0.06g of polyethylene glycol with a molecular weight of 400 and 0.44g of diethanolamine to a 250mL Erlenmeyer flask equipped with a magnetic stirrer, and mix well to prepare an alkaline catalytic base solution. Second, add 20g of tetraethyl orthosilicate and 30g of anhydrous ethanol to a beaker, and stir well with a glass rod to prepare a silicate ester solution. Finally, quickly pour the silicate ester solution into the alkaline catalytic base solution under stirring within 10 seconds; after the addition is complete, continue stirring the reaction at room temperature for 4 hours to obtain alkaline particulate silica sol.

[0087] Step (3), preparation of composite silica sol: Transfer 20g of the acidic silica sol prepared in step (1) into a constant pressure funnel, control the dropping time, and add it uniformly to the alkaline particulate silica sol (total mass about 100g) obtained in step (2) within 1.5h. After the dropping is completed, continue to stir the reaction at room temperature for 2h, and then let it stand for aging for 24h to obtain composite silica sol.

[0088] Step (4), prepare glass self-cleaning coating solution: dilute the above-mentioned aged composite silica sol with anhydrous ethanol to a solid content of 3.5%, and then add ethylene glycol butyl ether at 5% of the total mass of the solution, and mix evenly to obtain the glass self-cleaning coating solution.

[0089] Application Examples Application Example 1 This application example 1 provides a method for anti-reflective and self-cleaning treatment of photovoltaic module cover glass using the above-mentioned glass self-cleaning coating liquid. The specific steps are as follows: 1. Substrate pretreatment Photovoltaic ultra-clear patterned glass with dimensions of 1650mm×990mm was selected as the substrate. First, the glass surface was brushed with a brush roller containing cleaning agent to remove surface oil, dust and inorganic impurities; then, it was rinsed with deionized water until no foam residue remained in the rinsing water; finally, the glass surface was dried with an air knife to ensure that the surface was clean, dry and free of watermarks.

[0090] 2. Coating with coating solution The glass self-cleaning coating liquid prepared in Example 1 was selected. A roller coating process was used for coating: the coating liquid was injected into the feed tank of a precision roller coater, and the pressure and relative rotation speed between the coating roller and the glass substrate were adjusted to control the wet film thickness between 10 and 20 μm, forming a uniform and continuous liquid film on the glass surface.

[0091] 3. Curing at room temperature The coated glass is conveyed to a natural drying area via a conveyor belt and left to cure under ambient conditions of 25±5℃ and 40%~60% relative humidity. Due to the fast-drying properties of the coating solution, the film layer dries to the surface in about 10~15 minutes and forms a nano-coating with a "tennis ball" microstructure. It reaches a fully cured state after 24 hours.

[0092] 4. Application Effects The surface morphology of the film layer was tested and is shown in the image below. Figure 1 As shown, the average transmittance of the treated photovoltaic glass in the 380~760nm wavelength range is increased by 2.8% compared to the uncoated glass, and the water contact angle is less than 5°. In simulated outdoor dust environment tests, the amount of dust accumulation on the surface of the coated glass is extremely low, and there are no obvious watermarks after being washed by rainwater, effectively ensuring the power generation efficiency of the photovoltaic module.

[0093] Application Example 2 This application example 2 provides a method for tempering and self-cleaning architectural curtain wall glass using the above-mentioned glass self-cleaning coating liquid. The specific steps are as follows: 1. Substrate pretreatment Ordinary float glass with a thickness of 6mm was selected as the substrate and is intended for use in the curtain wall of a high-rise building. First, an industrial glass cleaning machine was used to perform multi-stage cleaning and pure water rinsing on the glass, followed by hot air drying to ensure the glass surface cleanliness meets the requirements for coating.

[0094] 2. Coating with coating solution The glass self-cleaning coating solution prepared in Example 1 was selected. A spray coating process was used: the coating solution was added to the reservoir of a high-pressure air spray gun, the air pressure of the spray gun was adjusted to 0.3~0.5MPa, and the distance between the nozzle and the glass surface was 20~30cm. During glass transport, a reciprocating sprayer was used to uniformly atomize and coat the glass surface, controlling the uniformity of the film thickness.

[0095] 3. Pre-drying and tempering / curing The glass coated with the coating solution is first dried in an infrared drying section at 120-150℃ for 2-3 minutes to allow the solvent to fully evaporate and form a preliminary film. Then, the glass is placed in a flat glass tempering furnace and heated at 680-700℃ for 180-300 seconds. This softens the glass while the organic components in the coating solution rapidly decompose and volatilize, and the inorganic silicon framework melts and sinters with the softened glass surface. Subsequently, the glass is rapidly introduced into a high-pressure air-cooling zone for quenching, completing the physical tempering process.

[0096] 4. Application Effects After high-temperature tempering, the nanocomposite coating on the glass surface achieves a strong chemical bond with the substrate, resulting in a film hardness of over 5H and significantly improved abrasion resistance. Despite undergoing high-temperature sintering, the film retains excellent superhydrophilicity (contact angle <10°) and self-cleaning function, and the coating surface is smooth and glossy without rainbow patterns, meeting the comprehensive requirements of building curtain walls for aesthetics, safety, and ease of cleaning and maintenance.

[0097] Although the coating solution of this invention contains a small amount of organic additives (such as polyethylene glycol and ethylene glycol butyl ether), these organic components will undergo oxidative decomposition and volatilization during high-temperature tempering (600~700℃). Simultaneously, the inorganic silicon-oxygen framework (Si-O-Si) formed by the hydrolysis and condensation of silicate esters has extremely high heat resistance. During tempering, it not only does not decompose but also melts and sinters with the softened glass substrate surface, forming a ceramicized inorganic coating. Therefore, this coating solution is perfectly suitable for tempering processes, and the adhesion of the tempered film is superior to that of a film cured at room temperature.

[0098] Performance testing To verify the performance of the glass self-cleaning coating solution and its film prepared in this invention, the coating solutions and coated glasses prepared in Examples 1-8 and Comparative Examples 1-10 were tested using the following methods, and the test results are recorded in Table 1.

[0099] 1. Testing Method Solid content test: The measured coating solution was quantitatively weighed into a pre-weighed beaker using a precision electronic balance, and the weight of the empty beaker, G, was recorded. 杯 and the measured weight of the solution G 液The beaker containing the test solution was placed in a 160℃ constant temperature drying oven for 1 hour. After being removed, it was transferred to a desiccator and cooled to room temperature. The total weight G of the beaker and the solid was then measured. (杯+固) .

[0100] Calculation formula: Solid content = (G (杯+固) -G 杯 ) / G 液 ×100%.

[0101] Stability test: The prepared coating solution was sealed and stored at room temperature (25℃). Its fluidity was observed until gelation occurred. The number of days from preparation to gelation was recorded.

[0102] Particle size distribution test: The coating solution was diluted 100 times with the corresponding diluent (anhydrous ethanol or isopropanol), dropped onto a clean silicon wafer, and allowed to dry naturally. The particle size distribution was then observed using a cold field emission scanning electron microscope (S-4700). The results were expressed as the range with the largest particle percentage (>80%).

[0103] Transmittance (anti-reflection) test: The transmittance (T) of the coating was measured using a HazeMeter haze meter from Hangzhou Caipu Technology Co., Ltd., with a wavelength range of 380~760nm. The coated glass was placed on the instrument's measuring platform, and the transmittance data at four different points were measured, and the average value was taken. The anti-reflection rate is the difference between the transmittance of the coated glass and the transmittance of the uncoated glass.

[0104] Contact angle test: The contact angle was measured using a PUOU-180 contact angle measuring instrument from PUOU Instruments Technology (Dongguan) Co., Ltd. Deionized water was dropped onto different areas of the same coated glass surface, and the contact angle was measured at at least four points. The results are expressed as an average. A contact angle <5° indicates an extremely low contact angle, where the water droplet spreads rapidly, exceeding the instrument's lower limit.

[0105] Dust collection test (self-cleaning performance): Prepare an inner circle with an area of First, weigh the crucible on a balance with a weight of 0.01%. Then, add 2-4g of cement ash (Tapai cement ash) or sand (from Gonghe County, Qinghai Province) to the crucible and record the total weight G'. Next, use a fixing ring and an antistatic elastic rope to invert the crucible onto the film surface of the coated glass being tested, and rotate it several times to ensure that the dust fully contacts and adheres to the film surface. After the test, remove the crucible and weigh it to obtain G″.

[0106] Calculation formula: Dust accumulation amount = (G' - G″) / S, unit: g / m 2 .

[0107] Tests were conducted on five different areas of the coated glass using a five-point sampling method. The maximum and minimum values ​​were removed, and the average value was taken. Note: The initial cement residue content of the original ultra-clear patterned glass sheet was 1.64 g / m². 2 The amount of dust contamination was 1.47 g / m³. 2 .

[0108] Surface resistance test: The surface resistance of coated glass was measured using a VICTOR 385 surface resistivity tester to evaluate its antistatic properties.

[0109] Photocatalytic decomposition performance test of organic matter: Cut the coated glass into strips of 1.5cm × 8cm, making a total of 4 strips. Place these strips into open-top glass bottles (40g capacity) and add 30g of a 2mg / L methylene blue solution. Irradiate the bottles with an intensity of 1.00W / m². 2 The solution was irradiated under a UV lamp, and the irradiation time required for the methylene blue solution to fade to colorless was recorded.

[0110] Qualitative test of film adhesion: Wrap a 1kg weight in a clean cloth and rub the weight back and forth on the film surface to observe whether the film peels off.

[0111] 2. Test Results The performance test results of the coating solutions provided in Examples 1-8 and Comparative Examples 1-10 are detailed in Table 1 below.

[0112] Table 1 Performance test data of Examples 1-8 and Comparative Examples 1-10

[0113] As shown in Table 1, Examples 1-8, the coating solutions prepared by this invention all exhibit good stability (9-14 days), and the formed films possess excellent properties including superhydrophilicity (contact angle <5°), high anti-reflection (2.0%-3.0%), and low dust accumulation (far lower than the original film). In Example 2, due to the use of strong alkaline catalysts such as ammonia, the resulting particles have a larger size (70-90 nm), and although the anti-reflection rate fluctuates slightly, the stability is the best. Example 7, after introducing P25, possesses the function of photocatalytic degradation of organic matter (methylene blue), but the anti-reflection rate decreases slightly due to the high refractive index of P25. In Example 8, after introducing ATO sol, the surface resistivity is significantly reduced to 10 Ω·cm. 9 Ω, its antistatic properties further reduce its dust accumulation to 0.13g / m 2 This indicates that by constructing a "tennis ball" microstructure, the present invention can effectively balance anti-reflective, hydrophilic, and stain-resistant properties, and is compatible with functional additives.

[0114] In contrast, the performance of the comparative examples was significantly reduced. The films prepared in Comparative Example 1 (insufficient acidic hydrolyzed water) and Comparative Example 4 (using a weak acid) exhibited extremely poor adhesion and detached easily upon wiping. This is because insufficient hydrolysis or a weak acidity in the acidic catalytic system prevented the formation of sufficient linear polysiloxane chains (i.e., a "network" structure). Lacking this "inorganic binder," the spherical particles accumulated only through weak physical point contact, unable to resist external friction. Comparative Example 2 (excessive acidic sol addition) resulted in an abnormally high contact angle of 27.8°. This was because the excessive gel-like network structure completely filled the pores between the spherical particles, causing the micro-nano rough structure originally formed by the accumulation of nanoparticles on the film surface to be "flattened." According to Wenzel's wetting theory, a decrease in surface roughness directly leads to the loss of superhydrophilic properties and also reduces permeability due to decreased porosity. Comparative Examples 3 and 10 both disrupted the kinetic balance of sol growth, leading to particle agglomeration or structural collapse, making it impossible to form a uniform "tennis ball" assembly, and resulting in a significant decrease in overall performance.

[0115] In summary, this invention, through a unique two-step process, precisely controls the formation and composite of acidic silica sol (network) and alkaline particulate silica sol (spheres), particularly by strictly limiting the dropping rate and ratio, successfully constructing a stable microstructure of "network structure encapsulating spherical particles." This structure not only solves the problem of poor adhesion in traditional nanosphere stacking films but also achieves a synergistic effect of superhydrophilicity, high antireflection, and excellent dust resistance at room temperature.

[0116] For those skilled in the art, other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations, but obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this invention.

Claims

1. A method for preparing a glass self-cleaning coating solution, characterized in that, Includes the following steps: Step (1): Mix silicate ester, diluent, deionized water and pH adjuster, and stir at room temperature to obtain acidic silica sol; Step (2): Prepare a silicate solution by mixing silicate ester and diluent; prepare an alkaline catalytic base solution by mixing deionized water, diluent, particle size modifier and catalyst; add the silicate ester solution dropwise to the alkaline catalytic base solution under stirring, and react at room temperature to obtain alkaline particulate silica sol; Step (3): The acidic silica sol obtained in step (1) is added dropwise to the alkaline particulate silica sol obtained in step (2), and after stirring and reacting at room temperature, it is allowed to stand and age to obtain composite silica sol. Step (4): Dilute the composite silica sol obtained in step (3) with a diluent and add a volatilization inhibitor to obtain the glass self-cleaning coating solution.

2. The method for preparing the glass self-cleaning coating solution according to claim 1, characterized in that, In step (1), the mass ratio of silicate ester, diluent, deionized water and pH adjuster is 20:40~60:8~12:0.4~0.6, and the reaction is carried out at room temperature with stirring for 3~5 hours.

3. The method for preparing the glass self-cleaning coating solution according to claim 1, characterized in that, In step (2), the mass ratio of silicate ester to diluent in the silicate ester solution is 15~25:25~35; the mass ratio of deionized water, diluent, particle size regulator and catalyst in the alkaline catalytic base liquid is 20~30:20~30:0.02~0.08:0.4~0.8; the silicate ester solution is added to the alkaline catalytic base liquid at a rate of 1~2 drops per second; and the reaction is carried out at room temperature with stirring for 3~5 hours.

4. The method for preparing the glass self-cleaning coating solution according to claim 1, characterized in that, In step (3), the mass ratio of the acidic catalytic silica sol to the alkaline particulate silica sol is 1:3~7, the acidic silica sol is added to the alkaline particulate silica sol over a period of 1~2 hours, stirring is continued for 1.5~2.5 hours, and the mixture is allowed to stand for 22~26 hours.

5. The method for preparing the glass self-cleaning coating solution according to claim 1, characterized in that, The silicate ester is selected from at least one of tetraethyl orthosilicate, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, dimethyldiethoxysilane, and diethyltriethoxysilane; The diluent is selected from ethanol or isopropanol; The pH adjuster is selected from hydrochloric acid or nitric acid; The catalyst is selected from one of diethanolamine, dimethylethanolamine, dimethylformamide, and ammonia water; The particle size regulator is polyethylene glycol with a molecular weight of 400-800; The volatile inhibitor is selected from one of ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol butyl ether, and diethylene glycol butyl ether.

6. The method for preparing the glass self-cleaning coating solution according to claim 1, characterized in that, In step (4), the solid content of the diluted composite silica sol is 3-4%, and the amount of the volatile inhibitor added is 5-7% of the total mass of the solution.

7. The method for preparing the glass self-cleaning coating solution according to claim 1, characterized in that, The coating solution also contains nano-titanium dioxide or titanium sol.

8. The method for preparing the glass self-cleaning coating solution according to claim 1, characterized in that, The coating solution also contains antimony-doped tin dioxide powder, phosphorus-doped tin dioxide sol, or antimony-doped tin dioxide sol.

9. A glass self-cleaning coating solution, characterized in that, Prepared by the preparation method according to any one of claims 1 to 8.

10. The application of the glass self-cleaning coating liquid as described in claim 9 in photovoltaic glass or architectural curtain wall glass, characterized in that, The self-cleaning glass coating liquid is applied to the surface of photovoltaic glass or building curtain wall glass, cured at room temperature or tempered along with the glass, forming a nano-composite coating with a mesh structure encapsulating spherical particles on the glass surface.

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