A coating solution, a preparation method and application thereof

Abstract

The application provides a coating solution and a preparation method and application thereof. The coating solution of the application comprises cationic polystyrene emulsion, a first solvent, silicate, a second solvent, silane coupling agent, a catalyst and boehmite. The coating solution is beneficial to improving the hardness and dirt resistance of the antireflection and anti-fouling film, has good chemical stability and excellent weather resistance. The application further provides a preparation method and application of the coating solution.

Description

Technical Field

[0001] This invention belongs to the field of solar glass manufacturing technology, specifically relating to a coating liquid, its preparation method, and its application. Background Technology

[0002] Solar photovoltaic (PV) is one of the most promising clean energy sources, and industry players are working hard to develop various advanced technologies and new products to improve photoelectric conversion efficiency. Among the factors determining the conversion efficiency of crystalline silicon solar cells, the most important is the crystalline silicon technology within the photovoltaic module, followed by the solar glass that protects the module. Relatively speaking, improving the optical properties of solar glass is easier and less costly than improving the conversion efficiency of crystalline silicon cells. Currently, most solar glass manufacturers are working to improve the light transmittance of photovoltaic glass, generally by adding an anti-reflective coating to the glass using the principle of light interference. This effectively reduces the loss of incident light, thereby improving photoelectric conversion efficiency.

[0003] Anti-reflection (AR) coating solutions are generally composed of silica sol, organic pore-forming agents, solvents, and additives. After coating, curing, and tempering, the pore-forming agents in the AR film are burned off, creating voids that reduce the film's refractive index, thus achieving anti-reflection and anti-reflection effects. However, the calcination of the organic pore-forming agents inevitably leaves open pores on the film surface that are connected to the atmosphere. These pores are easily penetrated by molten ethylene-vinyl acetate copolymer (EVA) during photovoltaic module assembly, leaving EVA residue after cooling, which is difficult to remove. Simultaneously, due to the numerous open pores on the surface of the anti-reflection film, photovoltaic modules easily absorb dust and vehicle exhaust during outdoor use, resulting in decreased light transmittance and reduced power generation efficiency. Moreover, the more organic pore-forming agents introduced, the higher the light transmittance, but the lower the mechanical strength of the film, and the more numerous and larger the pits on the film surface. Thus, increasing light transmittance and maintaining good dirt resistance versus high mechanical strength becomes a contradiction.

[0004] To address this issue, a Dutch company pioneered a coating solution for core-shell structured silica microspheres used in antireflective coatings. This solution is applied to the surface of ultra-clear photovoltaic glass. After curing and tempering, the organic cores of the nano-core-shell SiO2 microspheres in the film are burned away, forming hollow nano-SiO2 microspheres. This method places the pores inside the particles rather than within the silica network, thus ensuring both high porosity and mechanical strength while maintaining a dense surface, achieving both increased light transmittance and good resistance to dirt. However, the antireflective coating solution prepared by this method suffers from significant problems. Due to the extremely large specific surface area of ​​the nano-core-shell SiO2 and the abundance of active silanol groups on its surface, the particles easily aggregate, requiring large amounts of nitric acid to maintain solution stability. This results in a very low pH in the coating solution, causing significant corrosion to the coating rollers and posing substantial safety and environmental risks. Furthermore, these sol-gel mesoporous coatings contain numerous residual hydroxyl groups both inside and outside the structure. These hydroxyl groups can irreversibly chemically / physically adsorb moisture from the air through capillary condensation, causing swelling and alteration of the pore structure. As the pores are filled with moisture, the refractive index increases, leading to a significant decrease in the optical performance of the photovoltaic glass. Moreover, photovoltaic glass coated with this type of mesoporous antireflective and anti-reflective film is prone to fingerprints and belt marks during photovoltaic module assembly due to the presence of numerous active silanol groups on the film surface, and these marks are difficult to remove with alcohol. Therefore, a new coating solution still needs to be developed. Summary of the Invention

[0005] The present invention aims to at least solve one of the aforementioned technical problems existing in the prior art. To this end, the present invention provides a coating solution that improves the hardness and dirt resistance of antireflective and anti-reflective films, exhibits good chemical stability, and demonstrates excellent weather resistance.

[0006] The present invention also provides a method for preparing a coating solution.

[0007] The present invention also provides a glass coating.

[0008] The first aspect of the present invention provides a coating solution, the raw materials of which include cationic polystyrene emulsion, a first solvent, silicate ester, a second solvent, silane coupling agent, catalyst and boehmite.

[0009] One of the technical solutions of the present invention concerning the coating solution has at least the following beneficial effects:

[0010] The coating solution of this invention is beneficial for improving the hardness and dirt resistance of antireflective and anti-reflective films, and has good chemical stability and excellent weather resistance.

[0011] In the preparation of raw materials, the cationic polystyrene emulsion, the first solvent, and the silicate ester serve to prepare a silica-coated polystyrene nanosphere core-shell structure emulsion. The reaction of the silica-coated polystyrene nanosphere core-shell structure with a silane coupling agent allows the silane coupling agent to be grafted onto the surface of the microspheres. The presence of organic groups enhances the dispersion stability of the silica nanospheres, overcoming the drawback of requiring strong acid stability in the coating solution prepared from these microspheres. Simultaneously, the introduced silane coupling agent undergoes hydrolysis and condensation during film formation, forming polysiloxanes that fill the spaces between the silica nanosphere core-shell structure, enhancing the adhesion between silica particles and improving the hardness and dirt resistance of the anti-reflective and anti-reflective coating formed by the coating solution.

[0012] In the preparation of raw materials, boehmite is introduced into silica sol. Its special high porosity structure can give the film high light transmittance, and the Al-OH on its surface can dehydrate and condense with silanol groups to form Si-O-Al bonds, which enhances the chemical stability of the silica film and improves the weather resistance of the film.

[0013] According to some embodiments of the present invention, the mass ratio of the cationic polystyrene emulsion to the first solvent is 1:1 to 10.

[0014] According to some embodiments of the present invention, the first solvent includes at least one of water, methanol, alcohol and isopropanol.

[0015] According to some embodiments of the present invention, the second solvent includes at least one selected from methanol, alcohol, isopropanol, n-butanol, propylene glycol methyl ether, propylene glycol butyl ether, diethylene glycol butyl ether, and N,N-dimethylformamide.

[0016] According to some embodiments of the present invention, the catalyst comprises at least one selected from hydrochloric acid, nitric acid, formic acid, acetic acid, and citric acid. The pH of the solution is adjusted to 2-5.

[0017] According to some embodiments of the present invention, the silicate ester includes at least one selected from methyl orthosilicate, ethyl orthosilicate, polymethyl silicate, polyethyl orthosilicate-32, and polyethyl orthosilicate-40.

[0018] According to some embodiments of the present invention, the solid content of the cationic polystyrene emulsion accounts for 20-60% of the mass of the silicate ester.

[0019] According to some embodiments of the present invention, the silane coupling agent includes at least one selected from methyl orthosilicate, ethyl orthosilicate, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, and phenyltrimethoxysilane.

[0020] A second aspect of the present invention provides a method for preparing the coating solution of the present invention, comprising the following steps:

[0021] S1: After mixing the cationic polystyrene emulsion with the first solvent, the silicate ester is added, and the reaction is carried out under heat to obtain a silica-coated polystyrene nanocore-shell structured microsphere emulsion.

[0022] S2: The silica-coated polystyrene nanocore-shell structured microsphere emulsion is added to the second solvent, the silane coupling agent and catalyst are added, and the reaction is carried out at a higher temperature to obtain a modified nanocore-shell silica microsphere solution.

[0023] S3: After dispersing the boehmite, add it to the modified core-shell silica microsphere solution.

[0024] One technical solution of the present invention relating to the preparation method of the coating solution has at least the following beneficial effects:

[0025] The preparation method of the present invention does not require expensive equipment and complex process control, the reaction conditions are not harsh, the raw materials are readily available, the production cost is low, and it is easy to industrialize.

[0026] The preparation method of this invention involves reacting silica-coated polystyrene core-shell nanospheres with a silane coupling agent, thereby grafting the silane coupling agent onto the surface of the silica-coated polystyrene core-shell nanospheres. The presence of organic groups enhances the dispersion stability of the silica nanospheres, overcoming the drawback that the coating solution for preparing silica core-shell nanospheres requires strong acid stability. Simultaneously, the introduced silane coupling agent hydrolyzes and condenses during film formation to form polysiloxane, which fills the spaces between the silica core-shell nanospheres, enhancing the adhesion between silica particles and improving the hardness and dirt resistance of the antireflective and anti-reflective coating.

[0027] The preparation method of the present invention introduces dispersible boehmite into silica sol. Its special high porosity structure gives the film high light transmittance, and the Al-OH on its surface can dehydrate and condense with silanol groups to form Si-O-Al bonds, which enhances the chemical stability of the silica film and improves the weather resistance of the film.

[0028] In step S1: the cationic polystyrene emulsion is mixed with the first solvent, the silicate ester is added, and the reaction is carried out under heat to obtain a silica-coated polystyrene nanocore-shell structured microsphere emulsion.

[0029] The preparation method of the cationic polystyrene emulsion may be:

[0030] PS cores were prepared using a soap-free emulsion polymerization method. The comonomer methacryloyloxyethyltrimethylammonium chloride and 100 mL of water were weighed and placed in a 250 mL four-necked flask. Styrene was added under mechanical stirring at 250 rpm for 50 min. Under nitrogen protection, the temperature was raised to 70 °C, and an aqueous solution containing the initiator azobisisobutylamidine hydrochloride was added dropwise at a rate of 0.5 mL / min. The reaction was allowed to proceed for 24 h, yielding a stable cationic polystyrene emulsion with an average particle size of 150 nm and a solids content of approximately 17%.

[0031] The proportions of the comonomer, styrene monomer, initiator, and water in the entire system are as follows: comonomer 2.5%, styrene 15%, initiator 0.6%, and water 81.9%.

[0032] After the cationic polystyrene emulsion is mixed with the first solvent, the silicate ester is added. Under stirring at room temperature, the silicate ester is slowly added dropwise over a period of 1 to 3 hours. After the addition is complete, the reaction is maintained at the temperature for 3 to 12 hours.

[0033] According to some embodiments of the present invention, the mass ratio of the cationic polystyrene emulsion to the first solvent is 1:0.5 to 10.

[0034] According to some embodiments of the present invention, the mass ratio of the cationic polystyrene emulsion to the first solvent is 1:0.5 to 2.

[0035] According to some embodiments of the present invention, the temperature of the heat preservation reaction is 20°C to 50°C.

[0036] According to some embodiments of the present invention, the heat preservation reaction time is 3h to 12h.

[0037] In step S2: the silica-coated polystyrene nano-core-shell structured microsphere emulsion is added to the second solvent, the silane coupling agent and catalyst are added, and the reaction is carried out at a higher temperature to obtain a modified nano-core-shell silica microsphere solution.

[0038] The silane coupling agent and catalyst are added under stirring conditions. The silane coupling agent is added all at once first, followed by the catalyst solution.

[0039] According to some embodiments of the present invention, the temperature of the heating reaction is 25°C to 80°C.

[0040] According to some embodiments of the present invention, the heating reaction time is 4h to 24h.

[0041] In step S3: dispersing the boehmite can be achieved by stirring and dispersing the boehmite in an alcohol-water solution.

[0042] Introducing dispersed boehmite into silica sol results in a film with high light transmittance due to its unique high porosity structure. Furthermore, the Al-OH on its surface can dehydrate and condense with silanol groups to form Si-O-Al bonds, which enhances the chemical stability of the silica film and improves its weather resistance.

[0043] According to some embodiments of the present invention, the method further includes, after step S3, diluting the product to a solid content of 3% to 8%.

[0044] A third aspect of the present invention provides a glass coating prepared from the coating solution of the present invention.

[0045] One of the technical solutions of the present invention concerning glass coating has at least the following beneficial effects:

[0046] The glass coating of the present invention, by introducing a silane coupling agent during the preparation process, helps to enhance the dispersion stability of nano-silica microspheres and forms polysiloxane filler during the film formation process, which is beneficial to improving the hardness of the antireflective and anti-reflective film.

[0047] The glass coating of the present invention, by introducing silane coupling agent and polysiloxane filler, can strengthen the adhesion between silica particles, which helps to improve the dirt resistance and make the glass surface easier to clean.

[0048] The glass coating of this invention exhibits excellent chemical stability. The introduction of boehmite enhances the chemical stability of the silica film, and the formation of Si-O-Al bonds helps improve the film's environmental stability.

[0049] The glass coating of this invention exhibits superior weather resistance. The high porosity structure of boehmite and its reaction with silanol groups contribute to improving the weather resistance of the coating, making it more resistant to external environmental erosion and extending the coating's lifespan.

[0050] The glass coating of this invention has higher light transmittance. The high porosity structure of boehmite gives the film high light transmittance, which helps maintain the transparency of the glass.

[0051] A fourth aspect of the present invention provides a method for manufacturing a solar photovoltaic cell encapsulation glass.

[0052] The coating solution of the present invention can be applied to the cleaned and dried solar cell encapsulation glass substrate by any of the following coating methods: spraying, dipping, lifting, roller coating, spin coating, flow coating, and brush coating. After the surface is dried, it is baked and cured at 80°C to 250°C. Finally, the glass is tempered at 500°C to 700°C for 3 to 5 minutes to obtain the finished solar cell encapsulation glass. Detailed Implementation

[0053] The following are specific embodiments of the present invention, and the technical solutions of the present invention will be further described in conjunction with the embodiments, but the present invention is not limited to these embodiments.

[0054] In some embodiments of the present invention, a coating solution is provided, the raw materials for which include cationic polystyrene emulsion, a first solvent, silicate ester, a second solvent, silane coupling agent, catalyst, and boehmite.

[0055] It is understood that the coating solution of the present invention is beneficial to improving the hardness and dirt resistance of the antireflective and anti-reflective coating, and has good chemical stability and excellent weather resistance.

[0056] Specifically, in the preparation of raw materials, the cationic polystyrene emulsion, the first solvent, and the silicate ester serve to prepare a silica-coated polystyrene nanosphere core-shell structure emulsion. The reaction of the silica-coated polystyrene nanosphere core-shell structure with the silane coupling agent allows the silane coupling agent to be grafted onto the surface of the microspheres. The presence of organic groups enhances the dispersion stability of the silica nanospheres, overcoming the drawback of requiring strong acid stability in the coating solution prepared from the silica nanosphere core-shell structure. Simultaneously, the introduced silane coupling agent undergoes hydrolysis and condensation during film formation, forming polysiloxanes that fill the spaces between the silica nanosphere core-shell structure, enhancing the adhesion between silica particles and improving the hardness and dirt resistance of the anti-reflective and anti-reflective coating formed by the coating solution.

[0057] Furthermore, in the preparation of raw materials, boehmite is introduced into silica sol. Its special high porosity structure can give the film high light transmittance, and the Al-OH on its surface can dehydrate and condense with silanol groups to form Si-O-Al bonds, which enhances the chemical stability of the silica film and improves the weather resistance of the film.

[0058] It should be noted that a catalyst must be added, so its role is to catalyze the hydrolysis and condensation reaction of silanes. The amount of catalyst added varies depending on the type of acid, and can be determined by controlling the pH between 2 and 5.

[0059] In some embodiments of the present invention, the mass ratio of cationic polystyrene emulsion to the first solvent is 1:1 to 10.

[0060] In some embodiments of the present invention, the first solvent includes at least one of water, methanol, alcohol and isopropanol.

[0061] In some embodiments of the present invention, the second solvent includes at least one of methanol, alcohol, isopropanol, n-butanol, propylene glycol methyl ether, propylene glycol butyl ether, diethylene glycol butyl ether, and N,N-dimethylformamide.

[0062] It should be noted that the role of the second solvent is to provide the reaction environment and adjust the solubility.

[0063] In some embodiments of the present invention, the catalyst includes at least one selected from hydrochloric acid, nitric acid, formic acid, acetic acid, and citric acid. The pH of the solution is adjusted to 2-5.

[0064] In some embodiments of the present invention, the silicate ester includes at least one of methyl orthosilicate, ethyl orthosilicate, polymethyl silicate, polyethyl orthosilicate-32, and polyethyl orthosilicate-40.

[0065] In some embodiments of the present invention, the solid content of the cationic polystyrene emulsion accounts for 20-60% of the mass of the silicate ester. It should be noted that "solid content" here refers to the solid content.

[0066] In some embodiments of the present invention, the silane coupling agent includes at least one selected from methyl orthosilicate, ethyl orthosilicate, methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-(methacryloyloxy)propyltrimethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, and phenyltrimethoxysilane.

[0067] In other embodiments of the present invention, a method for preparing the coating solution of the present invention is provided, comprising the following steps:

[0068] S1: After mixing the cationic polystyrene emulsion with the first solvent, add silicate ester and keep it at a warm temperature to obtain a silica-coated polystyrene nanocore-shell structured microsphere emulsion.

[0069] S2: Add the polystyrene nano-core-shell structured microsphere emulsion coated with silica to the second solvent, add silane coupling agent and catalyst, and heat the reaction to obtain a modified nano-core-shell silica microsphere solution.

[0070] S3: After dispersing boehmite, add it to the modified core-shell silica microsphere solution.

[0071] It is understood that the preparation method of the present invention does not require expensive equipment and complex process control, the reaction conditions are not harsh, the raw materials are readily available, the production cost is low, and it is easy to industrialize.

[0072] The preparation method of this invention involves reacting silica-coated polystyrene core-shell nanospheres with a silane coupling agent, thereby grafting the silane coupling agent onto the surface of the silica-coated polystyrene core-shell nanospheres. The presence of organic groups enhances the dispersion stability of the silica nanospheres, overcoming the drawback that the coating solution for preparing silica core-shell nanospheres requires strong acid stability. Simultaneously, the introduced silane coupling agent hydrolyzes and condenses during film formation to form polysiloxane, which fills the spaces between the silica core-shell nanospheres, enhancing the adhesion between silica particles and improving the hardness and dirt resistance of the antireflective and anti-reflective coating.

[0073] The preparation method of the present invention introduces dispersible boehmite into silica sol. Its special high porosity structure gives the film high light transmittance, and the Al-OH on its surface can dehydrate and condense with silanol groups to form Si-O-Al bonds, which enhances the chemical stability of the silica film and improves the weather resistance of the film.

[0074] Specifically, in step S1: after mixing the cationic polystyrene emulsion with the first solvent, silicate ester is added, and the reaction is carried out at a certain temperature to obtain a silica-coated polystyrene nanosphere emulsion with a core-shell structure. The preparation method of the cationic polystyrene emulsion can be as follows:

[0075] PS cores were prepared using a soap-free emulsion polymerization method. The comonomer methacryloyloxyethyltrimethylammonium chloride and 100 mL of water were weighed and placed in a 250 mL four-necked flask. Styrene was added under mechanical stirring at 250 rpm for 50 min. Under nitrogen protection, the temperature was raised to 70 °C, and an aqueous solution containing the initiator azobisisobutylamidine hydrochloride was added dropwise at a rate of 0.5 mL / min. The reaction was allowed to proceed for 24 h, yielding a stable cationic polystyrene emulsion with an average particle size of 150 nm and a solids content of approximately 17%.

[0076] The proportions of the comonomer, styrene monomer, initiator, and water in the entire system are as follows: comonomer 2.5%, styrene 15%, initiator 0.6%, and water 81.9%.

[0077] After mixing the cationic polystyrene emulsion with the first solvent, silicate ester is added. Under stirring at room temperature, the silicate ester is slowly added dropwise over a period of 1 to 3 hours. After the addition is complete, the reaction is maintained at this temperature for 3 to 12 hours.

[0078] In some embodiments of the present invention, the mass ratio of cationic polystyrene emulsion to the first solvent is 1:0.5 to 10.

[0079] In some embodiments of the present invention, the mass ratio of cationic polystyrene emulsion to the first solvent is 1:0.5 to 2.

[0080] In some embodiments of the present invention, the temperature of the heat preservation reaction is 20°C to 50°C.

[0081] In some embodiments of the present invention, the heat preservation reaction time is 3h to 12h.

[0082] In step S2: The polystyrene nano-core-shell structured microsphere emulsion coated with silica is added to the second solvent, along with a silane coupling agent and a catalyst. The mixture is heated to react and a modified nano-core-shell silica microsphere solution is obtained.

[0083] The silane coupling agent and catalyst are added under stirring conditions. The silane coupling agent is added all at once first, followed by the catalyst solution.

[0084] In some embodiments of the present invention, the temperature of the heating reaction is 25°C to 80°C.

[0085] In some embodiments of the present invention, the heating reaction time is 4h to 24h.

[0086] In step S3: dispersing boehmite can be achieved by stirring and dispersing boehmite in an alcohol-water solution.

[0087] Introducing dispersed boehmite into silica sol results in a film with high light transmittance due to its unique high porosity structure. Furthermore, the Al-OH on its surface can dehydrate and condense with silanol groups to form Si-O-Al bonds, which enhances the chemical stability of the silica film and improves its weather resistance.

[0088] In some embodiments of the present invention, the method further includes diluting the product to a solid content of 3% to 8% after step S3.

[0089] In other embodiments of the present invention, a glass coating is provided, which is prepared from the coating solution of the present invention.

[0090] It is understood that the glass coating of the present invention, by introducing a silane coupling agent during the preparation process, helps to enhance the dispersion stability of the nano-silica microspheres and forms a polysiloxane filler during the film formation process, which is beneficial to improving the hardness of the antireflective and anti-reflective film.

[0091] It can also be understood that the glass coating of the present invention, by introducing silane coupling agent and polysiloxane filler, can strengthen the adhesion between silica particles, which helps to improve the dirt resistance and make the glass surface easier to clean.

[0092] It should be noted that the glass coating of the present invention exhibits excellent chemical stability. The introduction of boehmite enhances the chemical stability of the silica film, and the formation of Si-O-Al bonds helps to improve the film's environmental stability.

[0093] Furthermore, the glass coating of this invention exhibits superior weather resistance. The high porosity structure of boehmite and its reaction with silanol groups contribute to improving the weather resistance of the coating, making it more resistant to external environmental erosion and extending the coating's lifespan.

[0094] Importantly, the glass coating of this invention has higher light transmittance. The high porosity structure of boehmite gives the film high light transmittance, which helps maintain the transparency of the glass.

[0095] In other embodiments of the present invention, a method for manufacturing solar photovoltaic cell encapsulation glass is provided.

[0096] The coating solution of the present invention can be applied to the cleaned and dried solar cell encapsulation glass substrate by any of the following coating methods: spraying, dipping, lifting, roller coating, spin coating, flow coating, and brush coating. After the surface is dried, it is baked and cured at 80°C to 250°C. Finally, the glass is tempered at 500°C to 700°C for 3 to 5 minutes to obtain the finished solar cell encapsulation glass.

[0097] The technical solution of the present invention will be better understood below with reference to specific embodiments.

[0098] It should be noted that all reagents used in the examples were obtained from commercially available sources.

[0099] Boehmite is a dispersible nano-boehmite produced by Tianjin Boyuan High-Tech Materials Co., Ltd.

[0100] Example 1

[0101] 1. Preparation of cationic polystyrene template agent

[0102] PS cores were prepared using a soap-free emulsion polymerization method. The comonomer methacryloyloxyethyltrimethylammonium chloride and 100 mL of water were weighed and placed in a 250 mL four-necked flask. Styrene was added under mechanical stirring at 250 rpm for 50 min. Under nitrogen protection, the temperature was raised to 70 °C, and an aqueous solution containing the initiator azobisisobutylamidine hydrochloride was added dropwise at a rate of 0.5 mL / min. The reaction was allowed to proceed for 24 h, yielding a stable cationic polystyrene emulsion with an average particle size of 80 nm and a solids content of 17%.

[0103] The mass proportions of the comonomer, styrene monomer, initiator, and water in the entire system are as follows: comonomer 2.5%, styrene 15%, initiator 0.6%, and water 81.9%.

[0104] 2. Preparation of a dirt-resistant, weakly acidic, anti-reflective, and anti-reflective coating solution

[0105] (1) Take 332.8g of cationic polystyrene emulsion and 530g of ethanol and mix them evenly. Under the stirring condition at room temperature, slowly add 230g of ethyl silicate dropwise over a period of 2.5h. After the addition is complete, keep the mixture warm for 5h to obtain silica-coated polystyrene nano-core-shell structured microsphere emulsion A.

[0106] (2) 100g of the above silica-coated polystyrene nanocore-shell structured microsphere emulsion A was added to 140g of ethanol solvent. Under stirring conditions, 30g of tetraethyl orthosilicate and 6g of methyltriethoxysilane were added at once, followed by 10g of catalyst aqueous solution (2% mass fraction hydrochloric acid aqueous solution). The temperature was raised to 45℃ to start the reaction, and the reaction time was 12h to obtain modified nanocore-shell silica microsphere solution B.

[0107] (3) 20g of dispersible boehmite was stirred and dispersed in a mixed solution of 8g water and 32g ethanol to obtain C;

[0108] (4) Take 20gC and add it to 100gB and stir evenly. Then dilute with ethanol to a solid content of 4% to obtain a dirt-resistant, weakly acidic, anti-reflective, and anti-reflective coating solution.

[0109] 3. Manufacturing method of solar photovoltaic cell encapsulation glass

[0110] The above-mentioned dirt-resistant, weakly acidic, anti-reflective, and anti-reflective coating solution was applied to solar ultra-clear glass using a roller coating method, and then baked and cured at 180°C. After tempering at 680-720°C, dirt-resistant, anti-reflective, and anti-reflective coated glass was obtained.

[0111] Example 2

[0112] 1. Preparation of cationic polystyrene template agent

[0113] PS cores were prepared using a soap-free emulsion polymerization method. The comonomer methacryloyloxyethyltrimethylammonium chloride and 100 mL of water were weighed and placed in a 250 mL four-necked flask. Styrene was added under mechanical stirring at 250 rpm for 50 min. Under nitrogen protection, the temperature was raised to 70 °C, and an aqueous solution containing the initiator azobisisobutylamidine hydrochloride was added dropwise at a rate of 0.5 mL / min. The reaction was allowed to proceed for 24 h, yielding a stable cationic polystyrene emulsion with an average particle size of 80 nm and a solids content of 17%.

[0114] The mass proportions of the comonomer, styrene monomer, initiator, and water in the entire system are as follows: comonomer 2.5%, styrene 15%, initiator 0.6%, and water 81.9%.

[0115] 2. Preparation of a dirt-resistant, weakly acidic, anti-reflective, and anti-reflective coating solution

[0116] (1) Take 400g of cationic polystyrene emulsion and 540g of water and mix them evenly. Under the stirring condition at room temperature, slowly add 230g of methyl silicate dropwise over a period of 2.5h. After the addition is complete, keep the mixture warm for 5h to obtain silica-coated polystyrene nano-core-shell structured microsphere emulsion A.

[0117] (2) 100g of the above-mentioned silica-coated polystyrene nanocore-shell structured microsphere emulsion A was added to 100g of isopropanol solvent. Under stirring conditions, 36g of methyltriethoxysilane was added to it all at once, and then 10g of catalyst solution (2% mass fraction citric acid alcohol solution) was added. The temperature was raised to 45℃ to start the reaction, and the reaction time was 12h to obtain modified nanocore-shell silica microsphere solution B.

[0118] (3) 20g of dispersible boehmite was stirred and dispersed in a mixed solution of 8g water and 32g ethanol to obtain C;

[0119] (4) Take 10gC and add it to 100gB and stir evenly. Then dilute with ethanol to a solid content of 4% to obtain a dirt-resistant, weakly acidic, anti-reflective, and anti-reflective coating solution.

[0120] 3. Manufacturing method of solar photovoltaic cell encapsulation glass

[0121] The above-mentioned dirt-resistant, weakly acidic, anti-reflective, and anti-reflective coating solution was applied to solar ultra-clear glass using a roller coating method, and then baked and cured at 180°C. After tempering at 680-720°C, dirt-resistant, anti-reflective, and anti-reflective coated glass was obtained.

[0122] Example 3

[0123] 1. Preparation of cationic polystyrene template agent

[0124] PS cores were prepared using a soap-free emulsion polymerization method. The comonomer methacryloyloxyethyltrimethylammonium chloride and 100 mL of water were weighed and placed in a 250 mL four-necked flask. Styrene was added under mechanical stirring at 250 rpm for 50 min. Under nitrogen protection, the temperature was raised to 70 °C, and an aqueous solution containing the initiator azobisisobutylamidine hydrochloride was added dropwise at a rate of 0.5 mL / min. The reaction was allowed to proceed for 24 h, yielding a stable cationic polystyrene emulsion with an average particle size of 80 nm and a solids content of 17%.

[0125] The mass proportions of the comonomer, styrene monomer, initiator, and water in the entire system are as follows: comonomer 2.5%, styrene 15%, initiator 0.6%, and water 81.9%.

[0126] 2. Preparation of a dirt-resistant, weakly acidic, anti-reflective, and anti-reflective coating solution

[0127] (1) Take 455g of cationic polystyrene emulsion, 246g of water and 300g of alcohol and mix them evenly. Under the stirring condition at room temperature, slowly add 230g of methyl silicate dropwise over a period of 2.5h. After the addition is complete, keep the mixture warm for 5h to obtain silica-coated polystyrene nano-core-shell structured microsphere emulsion A.

[0128] (2) 100g of the above-mentioned silica-coated polystyrene nanocore-shell structured microsphere emulsion A was added to 100g of isopropanol solvent. Under stirring conditions, 20.8g of tetraethyl orthosilicate and 35g of γ-(methacryloyloxy)propyltrimethoxysilane were added at once, followed by 10g of catalyst solution (2% mass fraction acetic acid alcohol solution). The temperature was raised to 45℃ to start the reaction, and the reaction time was 12h to obtain modified nanocore-shell silica microsphere solution B.

[0129] (3) 20g of dispersible boehmite was stirred and dispersed in a mixed solution of 8g water and 32g ethanol to obtain C;

[0130] (4) Take 5gC and add it to 100gB and stir evenly. Then dilute with ethanol to a solid content of 4% to obtain a dirt-resistant, weakly acidic, anti-reflective, and anti-reflective coating solution.

[0131] 3. Manufacturing method of solar photovoltaic cell encapsulation glass

[0132] The above-mentioned dirt-resistant, weakly acidic, anti-reflective, and anti-reflective coating solution was applied to solar ultra-clear glass using a roller coating method, and then baked and cured at 180°C. After tempering at 680-720°C, dirt-resistant, anti-reflective, and anti-reflective coated glass was obtained.

[0133] Example 4

[0134] 1. Preparation of cationic polystyrene template agent

[0135] PS cores were prepared using a soap-free emulsion polymerization method. The comonomer methacryloyloxyethyltrimethylammonium chloride and 100 mL of water were weighed and placed in a 250 mL four-necked flask. Styrene was added under mechanical stirring at 250 rpm for 50 min. Under nitrogen protection, the temperature was raised to 70 °C, and an aqueous solution containing the initiator azobisisobutylamidine hydrochloride was added dropwise at a rate of 0.5 mL / min. The reaction was allowed to proceed for 24 h, yielding a stable cationic polystyrene emulsion with an average particle size of 80 nm and a solids content of 17%.

[0136] The mass proportions of the comonomer, styrene monomer, initiator, and water in the entire system are as follows: comonomer 2.5%, styrene 15%, initiator 0.6%, and water 81.9%.

[0137] 2. Preparation of a dirt-resistant, weakly acidic, anti-reflective, and anti-reflective coating solution

[0138] (1) Take 570g of cationic polystyrene emulsion, 360g of water and 200g of alcohol and mix them evenly. Under the stirring condition at room temperature, slowly add 230g of methyl silicate dropwise over a period of 2.5h. After the addition is complete, keep the mixture warm for 5h to obtain silica-coated polystyrene nano-core-shell structured microsphere emulsion A.

[0139] (2) 100g of the above-mentioned silica-coated polystyrene nanocore-shell structured microsphere emulsion A was added to 150g of isopropanol solvent. Under stirring conditions, 20.8g of tetraethyl orthosilicate and 30g of phenyltrimethoxysilane were added at once, followed by 10g of catalyst solution (2% mass fraction acetic acid alcohol solution). The temperature was raised to 45℃ to start the reaction, and the reaction time was 12h to obtain modified nanocore-shell silica microsphere solution B.

[0140] (3) 20g of dispersible boehmite was stirred and dispersed in a mixed solution of 8g water and 32g ethanol to obtain C;

[0141] (4) Take 8gC and add it to 100gB and stir evenly. Then dilute with ethanol to a solid content of 4% to obtain a dirt-resistant, weakly acidic, anti-reflective, and anti-reflective coating solution.

[0142] 3. Manufacturing method of solar photovoltaic cell encapsulation glass

[0143] The above-mentioned dirt-resistant, weakly acidic, anti-reflective, and anti-reflective coating solution was applied to solar ultra-clear glass using a roller coating method, and then baked and cured at 180°C. After tempering at 680-720°C, dirt-resistant, anti-reflective, and anti-reflective coated glass was obtained.

[0144] It should be noted that in Example 1, the second solvent was ethanol; in Example 2, the second solvent was water; and in Examples 3 and 4, the second solvent was a mixture of water and ethanol. Compared with the second solvent of mixed components, the solubility of the second solvent can be adjusted by changing its composition, thereby controlling the reaction rate and the particle size and monodispersity of the core-shell emulsion microspheres.

[0145] Comparative Example 1

[0146] 1. Preparation of cationic polystyrene template agent

[0147] The cationic polystyrene emulsion used in this embodiment was prepared according to the preparation method in CN105964195A.

[0148] PS cores were prepared using a soap-free emulsion polymerization method. Methacryloxyethyltrimethylammonium chloride and 100 mL of water were weighed and placed in a 250 mL four-necked flask. Styrene was added under mechanical stirring at 250 rpm for 50 min. Under nitrogen protection, the temperature was raised to 70 °C, and an aqueous solution containing the initiator azobisisobutylamidine hydrochloride was added dropwise at a rate of 0.5 mL / min. The reaction was allowed to proceed for 24 h, yielding a stable cationic polystyrene emulsion with an average particle size of 150 nm and a solids content of 17%.

[0149] The mass proportions of the comonomer, styrene monomer, initiator, and water in the entire system are as follows: comonomer 2.5%, styrene 15%, initiator 0.6%, and water 81.9%.

[0150] 2. Preparation of Strong Acid Anti-Reflective and Anti-Reflective Coating Solution

[0151] (2) Take the above 100 cationic polystyrene emulsion and 42g isopropanol and mix them evenly. Dilute the polystyrene emulsion to a solid content of 12% by mass. Under stirring conditions at 25°C, slowly add 113g of silicon source material tetraethoxysilane dropwise. React for 3h to obtain silica-coated polystyrene nanocore-shell structure microsphere emulsion A.

[0152] (3) Dilute 100g of polystyrene nano-core-shell structured microsphere emulsion A with 500g of isopropanol to a solid content of 4%, and add nitric acid to adjust the pH to 1.8 to obtain the coating solution.

[0153] 3. Manufacturing method of solar photovoltaic cell encapsulation glass

[0154] The above-mentioned dirt-resistant, weakly acidic, anti-reflective, and anti-reflective coating solution was applied to solar ultra-clear glass using a roller coating method, and then baked and cured at 180°C. After tempering at 680-720°C, dirt-resistant, anti-reflective, and anti-reflective coated glass was obtained.

[0155] Comparative Example 2

[0156] 1. Preparation of cationic polystyrene template agent

[0157] PS cores were prepared using a soap-free emulsion polymerization method. The comonomer methacryloyloxyethyltrimethylammonium chloride and 100 mL of water were weighed and placed in a 250 mL four-necked flask. Styrene was added under mechanical stirring at 250 rpm for 50 min. Under nitrogen protection, the temperature was raised to 70 °C, and an aqueous solution containing the initiator azobisisobutylamidine hydrochloride was added dropwise at a rate of 0.5 mL / min. The reaction was allowed to proceed for 24 h, yielding a stable cationic polystyrene emulsion with an average particle size of 80 nm and a solids content of 17%.

[0158] The mass proportions of the comonomer, styrene monomer, initiator, and water in the entire system are as follows: comonomer 2.5%, styrene 15%, initiator 0.6%, and water 81.9%.

[0159] 2. Preparation of a dirt-resistant, weakly acidic, anti-reflective, and anti-reflective coating solution

[0160] (1) Take 400g of cationic polystyrene emulsion and 540g of water and mix them evenly. Under the stirring condition at room temperature, slowly add 230g of methyl silicate dropwise over a period of 2.5h. After the addition is complete, keep the mixture warm for 5h to obtain silica-coated polystyrene nano-core-shell structured microsphere emulsion A.

[0161] (2) 100g of the above-mentioned silica-coated polystyrene nanocore-shell structured microsphere emulsion A was added to 100g of isopropanol solvent. Under stirring conditions, 36g of methyltriethoxysilane was added to it all at once, and then 10g of catalyst solution (2% mass fraction citric acid alcohol solution) was added. The temperature was raised to 45℃ to start the reaction, and the reaction time was 12h to obtain modified nanocore-shell silica microsphere solution B.

[0162] (3) Take 100g of the above modified nano-core-shell silica microsphere solution B and dilute it with ethanol to a solid content of 4% to obtain a dirt-resistant, weakly acidic, anti-reflective, and anti-reflective coating solution.

[0163] 3. Manufacturing method of solar photovoltaic cell encapsulation glass

[0164] The above-mentioned dirt-resistant, weakly acidic, anti-reflective, and anti-reflective coating solution was applied to solar ultra-clear glass using a roller coating method, and then baked and cured at 180°C. After tempering at 680-720°C, dirt-resistant, anti-reflective, and anti-reflective coated glass was obtained.

[0165] Test methods and results

[0166] (1) Transmittance test: The transmittance of the clean coated glass was measured using the AOPTEKGST-3 air-float tabletop spectral transmittance measurement system of Beijing AOPTEK Technology Co., Ltd., in accordance with the standard ISO9050.

[0167] (2) Testing of 3M tape: The Scotch 610-1PK tape of 3M Company was used for rapid testing. The test method is to lay the 3M tape flat and adhere it to the surface of the film layer, squeeze it with force, and then tear the tape at 90° perpendicular to the film surface. The residual film layer surface marks are rated as 1-5 according to the lightness or heaviness of the marks. Grade 1: no marks, Grade 2: very slight marks, Grade 3: relatively obvious marks, Grade 4: residual bright white marks, Grade 5: degummed. The higher the grade, the worse the dirt resistance. Grades not higher than 2 are considered qualified.

[0168] (3) Fingerprint test: Select a clean coated glass sample, press a fingerprint on the center of the glass surface, put the coated glass sample with the fingerprint in a constant temperature drying oven at (150±5)℃ for 30 minutes, take it out and cool it to room temperature, wipe it with alcohol, and observe whether the film surface leaves a mark. According to the lightness or heaviness of the mark on the surface of the residual film layer, it is rated as 1-5, with 1 being no mark, 2 being a very blurry mark, 3 being a slight mark, 4 being a relatively clear mark, and 5 being a very clear mark. The higher the grade, the worse the dirt resistance. A grade not higher than 2 is considered qualified.

[0169] (4) Hardness test: The pencil hardness of the coating was determined according to the Chinese national standard GB / T6739. The load was 750g, and the hardness ≥H met the national standard requirements and was rated as qualified.

[0170] (5) In accordance with the PCT test reference UL1703, the coated glass was placed in a PCT test chamber at 121℃, 100%RH, and 2atm and subjected to high temperature, high humidity, and high pressure for 96 hours. The appearance of the coated glass and the changes in light transmittance were observed. If the coated glass showed no peeling or discoloration and the light transmittance decreased by ≤1%, it passed the test and was deemed qualified. The results are shown in Table 1.

[0171] Table 1

[0172] solution pH Light transmittance 3M offset printing Handprint hardness PCT weather resistance Example 1 3.42 94.48 Level 1 Level 1 4H Pass the test Example 2 4.11 94.53 Level 1 Level 1 4H Pass the test Example 3 3.89 94.60 Level 1 Level 1 4H Pass the test Example 4 4.07 94.56 Level 1 Level 1 4H Pass the test Comparative Example 1 1.83 94.57 Level 1 Level 2 ＜H Not approved Comparative Example 2 4.04 94.54 Level 1 Level 1 H Not approved

[0173] As can be seen from Example 2 and Comparative Example 2, the hardness of Example 2 was significantly improved after the addition of dispersible boehmite. This may be because the boehmite alumina particles are embedded in the silica film at high temperature. Alumina has a higher hardness than silica, thus improving the hardness of the film. At the same time, the PCT weather resistance of Example 2 was significantly improved due to the introduction of dispersible boehmite. This is because the introduction of boehmite enhances the chemical stability of the silica film. Through the formation of Si-O-Al bonds, the stability of the film to the environment is improved, making it more resistant to external environmental erosion and extending the life of the coating.

[0174] Compared to the examples, Comparative Example 1 omits step S2, which involves modifying the silica-coated polystyrene nanospheres with a silane coupling agent. Therefore, a large amount of nitric acid is required to stabilize the antireflective and antireflective coating solution prepared in Comparative Example 1, necessitating a pH above 2.0, resulting in strong corrosiveness. Furthermore, since Comparative Example 1 directly uses a nano-core-shell silica emulsion to prepare the antireflective and antireflective coating solution, the deposited antireflective and antireflective film is formed by the accumulation of nano-core-shell silica particles. Without polysiloxane binders between the nano-silica particles, the film hardness is very low (<H), exhibiting poor resistance to dirt and failing the PCT weather resistance test.

[0175] The present invention has been described in detail above with reference to the embodiments. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A coating solution, characterized in that, The raw materials for preparation are cationic polystyrene emulsion, a first solvent, silicate ester, a second solvent, a silane coupling agent, a catalyst, and boehmite. The mass ratio of the cationic polystyrene emulsion to the first solvent is 1:1 to 10. The catalyst includes at least one selected from hydrochloric acid, nitric acid, formic acid, acetic acid, and citric acid, and the amount of catalyst added is such that the pH of the coating solution is 2.0 to 5.

0. The boehmite is dispersible nano-boehmite, and the silane coupling agent is selected from methyl orthosilicate, ethyl orthosilicate, methyltrimethoxysilane, and methyltriethoxysilane. The coating solution comprises at least one of the following: γ-hydroxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-glycidyl etheroxypropyltrimethoxysilane, γ-trimethylmethacryloyloxypropyltrimethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, and phenyltrimethoxysilane. The coating solution is used for anti-reflection and anti-reflection on the surface of solar glass, and the resulting film has a hardness of 4H and a transmittance attenuation of ≤1% after weathering tests at 121°C, 100%RH, 2atm, and 96hPCT. The coating solution is prepared by the following steps: S1: After mixing the cationic polystyrene emulsion with the first solvent, the silicate ester is added, and the reaction is carried out under heat to obtain a silica-coated polystyrene nanocore-shell structured microsphere emulsion. S2: The silica-coated polystyrene nanocore-shell structured microsphere emulsion is added to the second solvent, the silane coupling agent and catalyst are added, and the reaction is carried out at a higher temperature to obtain a modified nanocore-shell silica microsphere solution. S3: After dispersing the boehmite, add it to the modified core-shell silica microsphere solution.

2. The coating solution according to claim 1, characterized in that, The first solvent includes at least one of water, methanol, alcohol and isopropanol.

3. The coating solution according to claim 1, characterized in that, The second solvent includes at least one of methanol, alcohol, isopropanol, n-butanol, propylene glycol methyl ether, propylene glycol butyl ether, diethylene glycol butyl ether, and N,N-dimethylformamide.

4. A method for preparing a coating solution as described in any one of claims 1 to 3, characterized in that, Includes the following steps: S1: After mixing the cationic polystyrene emulsion with the first solvent, the silicate ester is added, and the reaction is carried out under heat to obtain a silica-coated polystyrene nanocore-shell structured microsphere emulsion. S2: The silica-coated polystyrene nanocore-shell structured microsphere emulsion is added to the second solvent, the silane coupling agent and catalyst are added, and the reaction is carried out at a higher temperature to obtain a modified nanocore-shell silica microsphere solution. S3: After dispersing the boehmite, add it to the modified core-shell silica microsphere solution.

5. The method according to claim 4, characterized in that, The temperature of the heat preservation reaction is 20℃~50℃; and / or the time of the heat preservation reaction is 3h~12h.

6. The method according to claim 4, characterized in that, The temperature of the heating reaction is 25℃~80℃; and / or the time of the heating reaction is 4h~24h.

7. The method according to claim 4, characterized in that, The method further includes, after step S3, diluting the product to a solid content of 3% to 8%.

8. A glass coating, characterized in that, It is prepared from the coating solution according to any one of claims 1 to 3.