Long-acting weather-resistant corrosion-resistant coating for surface of photovoltaic module and preparation method of long-acting weather-resistant corrosion-resistant coating

Abstract

The invention discloses a long-acting weather-resistant corrosion-resistant coating for the surface of a photovoltaic module and a preparation method of the long-acting weather-resistant corrosion-resistant coating, and relates to the technical field of protective coatings for the surface of the photovoltaic module. The invention discloses a long-acting weather-resistant and corrosion-resistant coating for the surface of a photovoltaic module. The coating is prepared from the following raw materials in parts by weight: 40 to 55 parts of modified fluorosilicone resin, 15 to 25 parts of epoxy resin, 5 to 10 parts of nano silicon dioxide, 3 to 8 parts of mica powder, 0.5 to 2 parts of modified graphene oxide, 8 to 15 parts of an isocyanate curing agent, 0.5 to 1.5 parts of a silane coupling agent KH-560, 2 to 2.5 parts of an ultraviolet light absorber UV-531, 1 to 1.5 parts of a hindered amine light stabilizer, 0.5 to 1.5 parts of an antioxidant 1010 and 0.3 to 1 part of a polyether modified polysiloxane flatting agent. 0.2 to 0.8 part of an organic siloxane compound defoaming agent; and 10 to 20 parts of an ethyl acetate-xylene mixed solvent. The coating disclosed by the invention has long-acting weather resistance and strong corrosion resistance, a compact protective barrier is constructed by the modified fluorosilicone resin and the modified graphene oxide, and the coating is adaptive to an outdoor complex environment; the construction property is excellent, the film forming quality is high, the service life of a photovoltaic module can be prolonged, the power generation stability is guaranteed, and the industrial adaptability is high.

Description

Technical Field

[0001] This invention relates to the field of protective coatings for photovoltaic modules, specifically a long-lasting weather-resistant and corrosion-resistant coating for photovoltaic modules and its preparation method. Background Technology

[0002] As the core component of a solar power generation system, photovoltaic modules are exposed to complex outdoor environments for extended periods. They must withstand multiple challenges, including ultraviolet radiation, high and low temperature cycles, alternating humidity and heat, salt spray corrosion, and the adhesion of industrial pollutants. The protective performance of their surface coating directly determines the lifespan and power generation efficiency of the modules.

[0003] While current photovoltaic module surface protective coatings offer basic protection, they still suffer from several technical shortcomings. Traditional coatings often employ a single resin system, resulting in insufficient weather resistance. After prolonged outdoor service, they are prone to aging phenomena such as cracking, chalking, and discoloration, leading to the failure of the protective layer and subsequently causing corrosion of the module substrate and a decrease in light transmittance. Regarding corrosion protection, conventional coatings struggle to form a dense physical barrier, failing to effectively prevent the penetration of corrosive media such as water vapor, salt, and acids / alkalis. In harsh environments like marine salt spray and industrial pollution, modules are susceptible to rust and oxidation, severely impacting power generation stability.

[0004] Meanwhile, existing coatings suffer from poor compatibility with various applications, easily resulting in defects such as pinholes, bubbles, and sagging during spraying. After film formation, their adhesion and mechanical properties are insufficient, making them unsuitable for the mechanical requirements of module processing, transportation, and installation. Furthermore, some protective coatings, in pursuit of weather resistance and corrosion resistance, neglect photoelectric conversion efficiency, leading to high optical loss or easy surface contamination, thus reducing solar transmittance and hindering the power generation efficiency of photovoltaic modules.

[0005] As the photovoltaic industry develops towards higher power and longer lifespan, higher demands are placed on the comprehensive performance of protective coatings for module surfaces, including long-term weather resistance, strong corrosion resistance, excellent workability, and low optical loss. Therefore, developing a long-lasting weather-resistant and corrosion-resistant coating for photovoltaic module surfaces that can synergistically address these technical challenges while balancing protective performance and photoelectric conversion efficiency has become a crucial issue that the industry urgently needs to overcome. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a long-lasting weather-resistant and corrosion-resistant coating for photovoltaic module surfaces and its preparation method, solving the problems of insufficient weather resistance, limited corrosion resistance, poor application compatibility and film quality, and difficulty in balancing protection and photoelectric conversion efficiency in existing photovoltaic module surface protective coatings.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A long-lasting weather-resistant and corrosion-resistant coating for photovoltaic module surfaces comprises the following raw materials in parts by weight: 40-55 parts modified fluorosilicone resin, 15-25 parts epoxy resin, 5-10 parts nano silica, 3-8 parts mica powder, 0.5-2 parts modified graphene oxide, 8-15 parts isocyanate curing agent, 0.5-1.5 parts silane coupling agent KH-560, 2-2.5 parts ultraviolet absorber UV-531, 1-1.5 parts hindered amine light stabilizer, 0.5-1.5 parts antioxidant 1010, 0.3-1 part polyether modified polysiloxane leveling agent, 0.2-0.8 parts organosiloxane composite defoamer, and 10-20 parts ethyl acetate-xylene mixed solvent.

[0008] Furthermore, the modified fluorosilicone resin is prepared using the following specific steps: A1. Add the fluorosilicone resin prepolymer to a four-necked flask, heat to 75-85℃, and stir for 30 min under nitrogen protection. Add a mixed solution of dodecyl fluoroheptyl acrylate and azobisisobutyronitrile dropwise at a rate of 2-3 ml / min. After the addition is complete, keep the mixture at the temperature for 4-6 h. Azobisisobutyronitrile triggers the grafting reaction, and dodecyl fluoroheptyl acrylate introduces fluorocarbon chains to improve hydrophobicity and weather resistance. Control the dropping rate to ensure uniform grafting. Then add dodecyl mercaptan. Dodecyl mercaptan controls the molecular weight distribution and avoids abnormal viscosity caused by excessive molecular weight. Heat to 90-95℃ to promote monomer conversion and continue the reaction for 1.5-2 h. Cool to room temperature to obtain the first modified fluorosilicone resin. A2. The first modified fluorosilicone resin and epichlorohydrin were added to a reaction vessel, cooled to 0-5℃, and boron trifluoride diethyl ether complex was slowly added dropwise. The mixture was stirred for 3-4 hours to catalyze ring opening and introduce epoxy groups into the resin to enhance crosslinking activity. The temperature was then raised to 30-40℃, and a 10% sodium hydroxide solution was added. The mixture was kept at this temperature for 2-3 hours and neutralized to pH 7-8. Unreacted epichlorohydrin and water were removed by vacuum distillation at -0.09 MPa and 60-70℃ to avoid residues affecting corrosion resistance, thus obtaining the second modified fluorosilicone resin. A3. Add the second modified fluorosilicone resin to a flask, add tetraethyl orthosilicate and silane coupling agent KH-560, stir evenly. The tetraethyl orthosilicate hydrolyzes to form a siloxane network to improve the coating hardness, and KH-560 strengthens the interface bonding between the resin and the filler. Add a mixture of 0.5% hydrochloric acid solution and deionized water dropwise, heat to 50-60℃, and perform hydrolysis and condensation reaction for 5-7 hours. After the reaction is completed, degas under reduced pressure at -0.08MPa and 40-50℃ for 30 minutes to obtain the modified fluorosilicone resin.

[0009] Furthermore, the modified graphene oxide is prepared using the following specific steps: B1. Graphene oxide was dispersed in N,N-dimethylformamide and ultrasonically dispersed at 400W for 30 min to obtain a uniform dispersion. Ethylenediamine and triethylamine were added, and the mixture was heated to 80-90℃ and refluxed for 8-10 h. Ethylenediamine grafting amino groups improved the resin compatibility, and triethylamine adjusted the reaction environment. After the reaction was completed, the mixture was centrifuged, and the precipitate was washed 3-4 times with ethanol. It was then dried under vacuum of -0.1MPa and at 60-70℃ for 12 h to obtain the first-modified graphene oxide. B2. The first-modified graphene oxide was dispersed in acetone and ultrasonically dispersed for 20 min. 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and benzoyl peroxide were added, and the mixture was heated to 60-70℃ and stirred for 6-8 h. The benzoyl peroxide initiator triggered the grafting reaction, and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide imparted flame retardant and aging resistance properties. The mixture was centrifuged, and the precipitate was washed 2-3 times with acetone. It was then dried under vacuum of -0.1 MPa and at 50-60℃ for 8 h to obtain the second-modified graphene oxide. B3. The second modified graphene oxide was dispersed in an ethanol-water mixture with a volume ratio of 3:1 and ultrasonically dispersed for 30 min. The pH was adjusted to 4-5 with a 1% acetic acid solution, and silane coupling agent KH-550 was added. The temperature was raised to 40-50℃ and the mixture was stirred for 4-6 h to enhance the interfacial bonding with the resin and the sheet barrier properties. The mixture was centrifuged, the precipitate was washed with water until neutral, and dried under a vacuum of -0.1 MPa at 60-70℃ for 10 h to obtain the modified graphene oxide.

[0010] Furthermore, the ratio of fluorosilicone resin prepolymer, dodecafluoroheptyl acrylate, azobisisobutyronitrile, and dodecathiol in A1 is 100g: 30-40g: 0.8-1.2g: 0.3-0.5g; the number average molecular weight of the fluorosilicone resin prepolymer is 2000-3000.

[0011] Furthermore, the ratio of the first modified fluorosilicone resin, epichlorohydrin, boron trifluoride diethyl ether complex, and sodium hydroxide solution in A2 is 100g: 15-20g: 0.5-1g: 5-8ml.

[0012] Furthermore, the ratio of the amount of the second modified fluorosilicone resin, tetraethyl orthosilicate, silane coupling agent KH-560, hydrochloric acid solution, and deionized water in A3 is 100g: 8-12g: 3-5g: 1-2ml: 5-8ml.

[0013] Furthermore, the ratio of graphene oxide, N,N-dimethylformamide, ethylenediamine, and triethylamine in B1 is 10g:80-100ml:15-20g:2-3ml.

[0014] Furthermore, the ratio of the first modified graphene oxide, acetone, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and benzoyl peroxide in B2 is 10g:50-60ml:8-12g:0.5-0.8g.

[0015] Furthermore, the ratio of the second modified graphene oxide, ethanol-water mixture, and silane coupling agent KH-550 in B3 is 10g:40-50ml:5-8g.

[0016] Furthermore, the organosiloxane composite defoamer is composed of organosiloxane and polyether in a mass ratio of 3:1, with a defoaming speed ≤5s and a foam suppression time ≥24h. This 3:1 compound defoamer balances rapid defoaming with long-term foam suppression, avoiding bubble defects during construction and curing, and ensuring coating density. The isocyanate curing agent is hexamethylene diisocyanate trimer with an NCO content of 20-23% and a viscosity of 800-1200 mPa·s at 25℃. The specific properties of the isocyanate curing agent match the reactivity of the base material, promoting the formation of a high-density cross-linked structure in the coating and improving hardness, adhesion, and corrosion resistance. The ethyl acetate-xylene mixed solvent has a volume ratio of ethyl acetate to xylene of 1:1, achieving a balance between solubility and evaporation rate. This ensures sufficient dissolution of the resin, curing agent, and other components while avoiding pinholes in the coating due to excessively rapid solvent evaporation or excessively slow evaporation affecting construction efficiency, thus guaranteeing the storage stability and film quality of the coating.

[0017] Furthermore, the mica powder is modified with a titanate coupling agent, specifically as follows: Mica powder was placed in a high-speed mixer and heated to 80°C. It was stirred and dehydrated for 30 minutes to remove surface moisture and prevent it from affecting the bonding effect. Then, isopropoxytristearatetoxytitanate and anhydrous ethanol were added. The titanate coupling agent chemically linked the mica powder to the organic matrix. The mixture was stirred at 1000 rpm for 60 minutes. High-speed stirring promoted uniform coating of the coupling agent, significantly improving the compatibility and dispersibility of the mica powder and the matrix, enhancing the coating's density and mechanical properties, and reducing the channels for corrosive media penetration. After cooling to room temperature, the material was discharged to obtain titanate-modified mica powder.

[0018] Furthermore, the ratio of mica powder, isopropoxytristearate titanate, and anhydrous ethanol is 100g:2g:3ml.

[0019] A method for preparing a long-lasting weather-resistant and corrosion-resistant coating for the surface of a photovoltaic module, specifically comprising the following steps: S1. Add 5-10 parts of nano-silica, 3-8 parts of mica powder, and 0.5-2 parts of modified graphene oxide to 5-10 parts of ethyl acetate-xylene mixed solvent. Stir at 800-1000 r / min for 30 min, then ultrasonically disperse at 500 W and 25-30℃ for 60 min to obtain a functional filler dispersion. Add 0.1-0.3 parts of organosiloxane complex defoamer to the dispersion, continue stirring for 15 min, and let stand for 20 min to defoam. The addition of defoamer and standing defoaming eliminate the bubbles generated during dispersion and prevent pinhole defects in the coating. S2. Add 40-55 parts of modified fluorosilicone resin and 15-25 parts of epoxy resin to the reactor, heat to 50-60℃, and stir at 600-800 r / min for 90 min; add 0.5-1.5 parts of silane coupling agent KH-560, and continue stirring for 75-80 min; then add 2-2.5 parts of ultraviolet absorber UV-531, 1-1.5 parts of hindered amine light stabilizer, 0.5-1.5 parts of antioxidant 1010, 0.3-1 parts of polyether modified polysiloxane leveling agent, and 0.1-0.5 parts of organosiloxane complex defoamer, and continue stirring for 40 min to obtain the base material mixture system; the additives are added step by step and stirred to ensure that each functional additive is evenly dispersed, avoid excessively high local concentrations, and synergistically exert anti-aging, leveling, and defoaming effects; S3. Slowly add the functional filler dispersion prepared in S1 to the base material mixing system in S2 while stirring at 800 r / min to avoid local agglomeration of the filler. After the addition is complete, continue stirring for 90 min. Transfer the mixture to a three-roll mill, control the roller temperature at 20-25℃, and grind 3-4 times with a roller speed ratio of 1:3:5. The first roller speed is 50 r / min. Control the particle size of the system after grinding to ≤5μm to improve the smoothness and density of the coating, enhance mechanical properties and corrosion resistance, and avoid the decrease in light transmittance caused by large particles, thus obtaining the coating base material. S4. Cool the coating base to 25-30℃, add 8-15 parts of isocyanate curing agent. Adding the curing agent at a low temperature avoids excessively rapid reaction. At the same time, slowly add 5-10 parts of ethyl acetate-xylene mixed solvent and stir at 500-600 r / min for 30 min. After stirring, degas at a vacuum of -0.09MPa and a temperature of 25-30℃ for 40 min, then pass through a 200-mesh sieve to thoroughly remove bubbles and impurities, ensuring smooth coating application and film quality, avoiding defects after curing, and obtaining a long-lasting weather-resistant and corrosion-resistant coating for the photovoltaic module surface.

[0020] Furthermore, the ultrasonic dispersion process in S1 adopts an intermittent ultrasonic mode, that is, ultrasonic operation for 5 minutes, followed by a 2-minute pause, and repeated until the cumulative ultrasonic time reaches 60 minutes. Intermittent ultrasonication avoids the system temperature rise caused by continuous ultrasonication, preventing solvent evaporation or deterioration of filler / resin properties, while ensuring the ultrasonic dispersion effect, ensuring uniform dispersion and good stability of the filler, and laying the foundation for excellent coating performance.

[0021] This invention provides a long-lasting weather-resistant and corrosion-resistant coating for the surface of photovoltaic modules and its preparation method, which has the following beneficial effects: 1. The coating of this invention possesses excellent long-term weather resistance, effectively meeting the long-term outdoor service requirements of photovoltaic modules. Through the synergistic compounding of modified fluorosilicone resin and epoxy resin, combined with the precise ratio of UV absorber UV-531 and hindered amine light stabilizer, a multi-layer anti-aging protection system is constructed. This system strongly resists the erosion of complex climatic environments such as ultraviolet radiation, high and low temperature cycles, and alternating humid and hot conditions, significantly slowing down the aging and degradation rate of the coating and preventing problems such as cracking, chalking, and discoloration. This ensures that the protective layer on the surface of the photovoltaic module maintains stable performance over a long period, extending the overall service life of the module. Simultaneously, the modified filler exhibits excellent compatibility with the base material, further enhancing the structural stability of the coating and making the weather protection effect more durable and reliable.

[0022] 2. This coating exhibits excellent corrosion resistance, providing comprehensive protection against various corrosive media. The layered barrier effect of modified graphene oxide, combined with the reinforcing effects of nano-silica and modified mica powder, forms a dense physical protective barrier within the coating. This effectively blocks the penetration of corrosive media such as water vapor, salt, and acids / alkalis, preventing corrosion and oxidation damage to the photovoltaic module substrate. Furthermore, the addition of a silane coupling agent optimizes the bonding strength between the coating and the substrate, reducing the accumulation of corrosive media at the interface. Whether in marine salt spray environments, industrial acid / alkali pollution environments, or humid and rainy environments, it provides comprehensive and long-lasting corrosion protection for photovoltaic modules, ensuring that the module's power generation efficiency is not affected by corrosion.

[0023] 3. The coating of this invention exhibits excellent application compatibility and film-forming quality, meeting the needs of industrial applications. The scientific combination of polyether-modified polysiloxane leveling agent and organosiloxane composite defoamer in the coating formulation effectively improves the coating's flowability, preventing defects such as pinholes, bubbles, and sagging during spraying, ensuring a smooth and even coating surface. Simultaneously, by precisely controlling the grinding particle size, dispersion method, and curing parameters in the preparation process, the coating film possesses excellent adhesion and mechanical properties, with moderate hardness and resistance to peeling and scratching. It can meet the mechanical requirements of processing, transportation, and installation in photovoltaic module production, and the application process is simple and controllable, allowing for efficient compatibility with existing photovoltaic module production lines and reducing industrial application costs.

[0024] 4. This coating ensures both protective performance and meets the photoelectric conversion efficiency requirements of photovoltaic modules. All components in the formula utilize low-optical-loss raw materials, and by optimizing filler particle size and dispersion uniformity, the coating reduces sunlight reflection and scattering losses, ensuring efficient light penetration to the photovoltaic cells. Furthermore, the coating exhibits excellent stain resistance; the low surface energy of the modified fluorosilicone resin reduces dust and stain adhesion and facilitates cleaning, maintaining module surface cleanliness over the long term. This prevents a decrease in light transmittance due to surface contamination, achieving a synergistic improvement in both protective performance and photoelectric conversion efficiency, providing strong support for the long-term stable and efficient power generation of photovoltaic modules. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1: Preparation of a long-lasting weather-resistant and corrosion-resistant coating for the surface of photovoltaic modules. The specific preparation steps are as follows: S1. Add 5 parts of nano-silica, 3 parts of mica powder, and 0.5 parts of modified graphene oxide to 5 parts of ethyl acetate-xylene mixed solvent. Stir at 800 r / min for 30 min, then intermittently sonicate at 500 W and 25℃, i.e., sonicate for 5 min, pause for 2 min, and repeat until the cumulative sonication time reaches 60 min to obtain a functional filler dispersion. Add 0.1 parts of organosiloxane complex defoamer to the dispersion, continue stirring for 15 min, and let stand for 20 min to defoam. S2. Add 40 parts of modified fluorosilicone resin and 15 parts of epoxy resin to the reactor, heat to 50℃, and stir at 600r / min for 90min; add 0.5 parts of silane coupling agent KH-560, and continue stirring for 75min; then add 2 parts of ultraviolet absorber UV-531, 1 part of hindered amine light stabilizer, 0.5 parts of antioxidant 1010, 0.3 parts of polyether modified polysiloxane leveling agent, and 0.1 parts of organosiloxane complex defoamer, and continue stirring for 40min to obtain the base material mixture system; S3. Slowly add the functional filler dispersion prepared in S1 to the base material mixing system in S2 while stirring at 800 r / min. After the addition is complete, continue stirring for 90 min. Transfer the mixture to a three-roll mill, control the roller temperature at 20℃, and grind 3 times with a roller speed ratio of 1:3:5. The first roller speed is 50 r / min. Control the particle size of the system after grinding to ≤5 μm to obtain the coating base material. S4. Cool the coating base to 25℃, add 8 parts of isocyanate curing agent, and slowly add 5 parts of ethyl acetate-xylene mixed solvent. Stir at 500r / min for 30min. After stirring, degas at a vacuum of -0.09MPa and a temperature of 25℃ for 40min, and then pass through a 200-mesh sieve to obtain a long-lasting weather-resistant and corrosion-resistant coating for the photovoltaic module surface.

[0027] Example 2: Preparation of a long-lasting weather-resistant and corrosion-resistant coating for the surface of photovoltaic modules. The specific preparation steps are as follows: S1. Add 10 parts of nano-silica, 8 parts of mica powder, and 2 parts of modified graphene oxide to 10 parts of ethyl acetate-xylene mixed solvent. Stir at 1000 r / min for 30 min, then intermittently sonicate at 500 W and 30℃, i.e., sonicate for 5 min, pause for 2 min, and repeat until the cumulative sonication time reaches 60 min to obtain a functional filler dispersion. Add 0.3 parts of organosiloxane complex defoamer to the dispersion, continue stirring for 15 min, and let stand for 20 min to defoam. S2. Add 55 parts of modified fluorosilicone resin and 25 parts of epoxy resin to the reactor, heat to 60℃, and stir at 800r / min for 90min; add 1.5 parts of silane coupling agent KH-560, and continue stirring for 80min; then add 2.5 parts of ultraviolet absorber UV-531, 1.5 parts of hindered amine light stabilizer, 1.5 parts of antioxidant 1010, 1 part of polyether modified polysiloxane leveling agent, and 0.5 parts of organosiloxane complex defoamer, and continue stirring for 40min to obtain the base material mixture system; S3. Slowly add the functional filler dispersion prepared in S1 to the base material mixing system in S2 while stirring at a speed of 800 r / min. After the addition is complete, continue stirring for 90 min. Transfer the mixture to a three-roll mill, control the roller temperature at 25℃, and grind 4 times with a roller speed ratio of 1:3:5. The first roller speed is 50 r / min. Control the particle size of the system after grinding to ≤5μm to obtain the coating base material. S4. Cool the coating base to 30℃, add 15 parts of isocyanate curing agent, and slowly add 10 parts of ethyl acetate-xylene mixed solvent. Stir at 600r / min for 30min. After stirring, degas at -0.09MPa and 30℃ for 40min, and then pass through a 200-mesh sieve to obtain a long-lasting weather-resistant and corrosion-resistant coating for the photovoltaic module surface.

[0028] Example 3: Preparation of a long-lasting weather-resistant and corrosion-resistant coating for the surface of photovoltaic modules. The specific preparation steps are as follows: S1. Add 7 parts of nano-silica, 5 parts of mica powder, and 1 part of modified graphene oxide to 7 parts of ethyl acetate-xylene mixed solvent. Stir at 900 r / min for 30 min, then intermittently sonicate at 500 W and 27℃, i.e., sonicate for 5 min, pause for 2 min, and repeat until the cumulative sonication time reaches 60 min to obtain a functional filler dispersion. Add 0.2 parts of organosiloxane complex defoamer to the dispersion, continue stirring for 15 min, and let stand for 20 min to defoam. S2. Add 47 parts of modified fluorosilicone resin and 20 parts of epoxy resin to the reactor, heat to 55℃, and stir at 700r / min for 90min; add 1 part of silane coupling agent KH-560 and continue stirring for 78min; then add 2.2 parts of ultraviolet absorber UV-531, 1.2 parts of hindered amine light stabilizer, 1 part of antioxidant 1010, 0.6 parts of polyether modified polysiloxane leveling agent and 0.3 parts of organosiloxane complex defoamer, and continue stirring for 40min to obtain the base material mixture system; S3. Slowly add the functional filler dispersion prepared in S1 to the base material mixing system in S2 while stirring at a speed of 800 r / min. After the addition is complete, continue stirring for 90 min. Transfer the mixture to a three-roll mill, control the roller temperature at 22℃, and grind 3 times with a roller speed ratio of 1:3:5. The first roller speed is 50 r / min. Control the particle size of the system after grinding to ≤5μm to obtain the coating base material. S4. Cool the coating base to 27°C, add 11 parts of isocyanate curing agent, and slowly add 7 parts of ethyl acetate-xylene mixed solvent. Stir at 550 r / min for 30 min. After stirring, degas at a vacuum of -0.09 MPa and a temperature of 27°C for 40 min, and then pass through a 200-mesh sieve to obtain a long-lasting weather-resistant and corrosion-resistant coating for the photovoltaic module surface.

[0029] Example 4: Preparation of modified fluorosilicone resin. The specific preparation steps are as follows: A1. Add 100g of fluorosilicone resin prepolymer to a four-necked flask, heat to 75℃, and stir for 30min under nitrogen protection; add dropwise a mixed solution of 30g dodecafluoroheptyl acrylate and 0.8g azobisisobutyronitrile at a dropping rate of 2ml / min, and keep the reaction at the temperature for 4h after the addition is complete; then add 0.3g dodecathiol, heat to 90℃ and continue the reaction for 1.5h, cool to room temperature to obtain the first modified fluorosilicone resin; A2. Add 100g of the first modified fluorosilicone resin and 15g of epichlorohydrin to a reaction vessel, cool to 0℃, slowly add 0.5g of boron trifluoride diethyl ether complex, and stir for 3h; heat to 30℃, add 5ml of 10% sodium hydroxide solution, keep warm for 2h, and neutralize to pH=7; remove unreacted epichlorohydrin and water by vacuum distillation at 60℃ under reduced pressure to obtain the second modified fluorosilicone resin; A3. Add 100g of the second modified fluorosilicone resin to a flask, add 8g of tetraethyl orthosilicate and 3g of silane coupling agent KH-560, and stir until homogeneous; add dropwise a mixture of 1ml of 0.5% hydrochloric acid solution and 5ml of deionized water, heat to 50℃, and perform hydrolysis and condensation reaction for 5h; after the reaction is completed, degas under reduced pressure at -0.08MPa and 40℃ for 30min to obtain the modified fluorosilicone resin.

[0030] Example 5: Preparation of modified fluorosilicone resin. The specific preparation steps are as follows: A1. Add 100g of fluorosilicone resin prepolymer to a four-necked flask, heat to 85℃, and stir for 30min under nitrogen protection; add dropwise a mixed solution of 40g dodecafluoroheptyl acrylate and 1.2g azobisisobutyronitrile at a dropping rate of 3ml / min, and keep the reaction at the temperature for 6h after the addition is complete; then add 0.5g dodecathiol, heat to 95℃ and continue the reaction for 2h, and cool to room temperature to obtain the first modified fluorosilicone resin; A2. Add 100g of the first modified fluorosilicone resin and 20g of epichlorohydrin to a reaction vessel, cool to 5℃, slowly add 1g of boron trifluoride diethyl ether complex, and stir for 4h; heat to 40℃, add 8ml of 10% sodium hydroxide solution, keep warm for 3h, and neutralize to pH=8; remove unreacted epichlorohydrin and water by vacuum distillation at 70℃ under reduced pressure to obtain the second modified fluorosilicone resin; A3. Add 100g of the second modified fluorosilicone resin to a flask, add 12g of tetraethyl orthosilicate and 5g of silane coupling agent KH-560, and stir until homogeneous; add dropwise a mixture of 2ml of 0.5% hydrochloric acid solution and 8ml of deionized water, heat to 60℃, and perform hydrolysis and condensation reaction for 7h; after the reaction is completed, degas under reduced pressure at -0.08MPa and 50℃ for 30min to obtain the modified fluorosilicone resin.

[0031] Example 6: Preparation of modified graphene oxide. The specific preparation steps are as follows: B1. 10g of graphene oxide was dispersed in 80ml of N,N-dimethylformamide and ultrasonically dispersed at 400W for 30min to obtain a uniform dispersion. 15g of ethylenediamine and 2ml of triethylamine were added, and the mixture was heated to 80℃ and refluxed for 8h. After the reaction was completed, the mixture was centrifuged, the precipitate was washed three times with ethanol, and dried under vacuum of -0.1MPa and temperature of 60℃ for 12h to obtain the first modified graphene oxide. B2. 10g of the first-modified graphene oxide was dispersed in 50ml of acetone and ultrasonically dispersed for 20min; 8g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 0.5g of benzoyl peroxide were added, the temperature was raised to 60℃, and the reaction was stirred for 6h; the mixture was centrifuged, the precipitate was washed twice with acetone, and dried under vacuum of -0.1MPa and temperature of 50℃ for 8h to obtain the second-modified graphene oxide; B3. Disperse 10g of the second modified graphene oxide in 40ml of ethanol-water mixture with a volume ratio of 3:1 and sonicate for 30min. Adjust the pH to 4 with 1% acetic acid solution, add 5g of silane coupling agent KH-550, heat to 40℃, and stir for 4h. Centrifuge, wash the precipitate with water until neutral, and dry under vacuum of -0.1MPa at 60℃ for 10h to obtain the modified graphene oxide.

[0032] Example 7: Preparation of modified graphene oxide. The specific preparation steps are as follows: B1. 10g of graphene oxide was dispersed in 100ml of N,N-dimethylformamide and ultrasonically dispersed at 400W for 30min to obtain a uniform dispersion. 20g of ethylenediamine and 3ml of triethylamine were added, and the mixture was heated to 90℃ and refluxed for 10h. After the reaction was completed, the mixture was centrifuged, the precipitate was washed 4 times with ethanol, and dried under vacuum of -0.1MPa and temperature of 70℃ for 12h to obtain the first modified graphene oxide. B2. 10g of the first-modified graphene oxide was dispersed in 60ml of acetone and ultrasonically dispersed for 20min; 12g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 0.8g of benzoyl peroxide were added, the temperature was raised to 70℃, and the reaction was stirred for 8h; the mixture was centrifuged, the precipitate was washed 3 times with acetone, and dried under vacuum of -0.1MPa and temperature of 60℃ for 8h to obtain the second-modified graphene oxide; B3. Disperse 10g of the second-modified graphene oxide in 50ml of ethanol-water mixture with a volume ratio of 3:1 and sonicate for 30min. Adjust the pH to 5 with 1% acetic acid solution, add 8g of silane coupling agent KH-550, heat to 50℃, and stir for 6h. Centrifuge, wash the precipitate with water until neutral, and dry at -0.1MPa vacuum and 70℃ for 10h to obtain the modified graphene oxide.

[0033] Comparative Example 1: A long-lasting weather-resistant and corrosion-resistant coating was prepared on the surface of a photovoltaic module. The specific preparation steps are as follows: The remaining steps remain unchanged, except that the modified fluorosilicone resin prepared in Example 4 used in Example 3 is replaced with unmodified fluorosilicone resin to prepare a long-lasting weather-resistant and corrosion-resistant coating for the surface of photovoltaic modules.

[0034] Comparative Example 2: A long-lasting weather-resistant and corrosion-resistant coating was prepared on the surface of a photovoltaic module. The specific preparation steps are as follows: The remaining steps remain unchanged, except that the modified graphene oxide prepared in Example 7 used in Example 3 is replaced with unmodified graphene oxide to prepare a long-lasting weather-resistant and corrosion-resistant coating for the surface of photovoltaic modules.

[0035] Comparative Example 3: A long-lasting weather-resistant and corrosion-resistant coating was prepared on the surface of a photovoltaic module. The specific preparation steps are as follows: The remaining steps remain unchanged, except that the modified fluorosilicone resin prepared in Example 4 used in Example 3 is replaced with unmodified fluorosilicone resin, and the modified graphene oxide prepared in Example 7 is replaced with unmodified graphene oxide, so as to prepare a long-lasting weather-resistant and corrosion-resistant coating for the surface of photovoltaic modules.

[0036] Performance testing Sample preparation: The surface of the glass substrate was wiped with acetone to remove oil, sanded with 1000-grit sandpaper, rinsed with deionized water, and dried at 80°C. The weather-resistant and corrosion-resistant coatings prepared in Examples 1-3 and Comparative Examples 1-3 were applied by spraying with a nozzle diameter of 1.0 mm, a spraying pressure of 0.4 MPa, a spraying distance of 25 cm, and the dry film thickness was controlled to be 50 μm. After spraying, the coating was first leveled at room temperature for 15 min, and then cured in stages: pre-cured at 60°C for 60 min, and finally cured at 120°C for 120 min. The surface protection treatment of the photovoltaic module was completed by cooling to room temperature.

[0037] Test Project Test Standards Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Gloss retention rate (wavelength 340nm, irradiance 0.51W / (m²・nm), black panel temperature 63℃, relative humidity 50%, xenon lamp aging for 1000h) (60° gloss was tested using GB / T9754-2025, and the retention rate was calculated) GB / T1865-2009 89% 92% 96% 72% 80% 65% Adhesion (cross-cut test) GB / T9286-2021 Level 1 Level 1 Level 0 Level 2 Level 2 Level 3 Pencil hardness GB / T6739-2022 2H 2H 3H H H B Resistance to neutral salt spray (1000h) GB / T1771-2007 Slight loss of gloss, no bubbling or peeling at the edges. Slight loss of gloss, no bubbling or peeling at the edges. No change Significant loss of gloss, slight bubbling at the edges Significant loss of gloss, minor pitting Severe loss of gloss, blistering, and peeling. Resistance to damp heat (temperature 40℃, relative humidity 95%, damp heat aging for 3000h, observe coating condition) GB / T1740-2007 No wrinkles or bubbles No wrinkles or bubbles No wrinkles or bubbles Slight bubbling Localized wrinkling Numerous blisters and localized detachment Performance test results show that the long-lasting weather-resistant and corrosion-resistant coatings for photovoltaic modules prepared in Examples 1-3 have significantly better overall performance than those in Comparative Examples 1-3. After 1000 hours of xenon lamp aging, the gloss retention rate of the examples reached 89%-96%, far exceeding the 65%-80% of the comparative examples; in terms of adhesion, the examples were grade 0-1, while the comparative examples were grade 2-3; the pencil hardness of the examples reached 2H-3H, which is better than the BH of the comparative examples; after 1000 hours of neutral salt spray resistance, the examples only showed slight loss of gloss or no change, while the comparative examples showed obvious loss of gloss, blistering, and even peeling; after 3000 hours of damp heat aging, the examples showed no wrinkling or blistering, while the comparative examples showed varying degrees of blistering, wrinkling, or peeling, indicating that the addition of modified fluorosilicone resin and modified graphene oxide plays a key role in improving the weather resistance, adhesion, hardness, and corrosion resistance of the coatings.

[0038] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A long-lasting weather-resistant and corrosion-resistant coating for the surface of photovoltaic modules, characterized in that: It contains the following raw materials in parts by weight: 40-55 parts modified fluorosilicone resin, 15-25 parts epoxy resin, 5-10 parts nano silica, 3-8 parts mica powder, 0.5-2 parts modified graphene oxide, 8-15 parts isocyanate curing agent, 0.5-1.5 parts silane coupling agent KH-560, 2-2.5 parts ultraviolet absorber UV-531, 1-1.5 parts hindered amine light stabilizer, 0.5-1.5 parts antioxidant 1010, 0.3-1 part polyether modified polysiloxane leveling agent, 0.2-0.8 parts organosiloxane complex defoamer, and 10-20 parts ethyl acetate-xylene mixed solvent.

2. The long-lasting weather-resistant and corrosion-resistant coating for photovoltaic module surfaces according to claim 1, characterized in that: The modified fluorosilicone resin is prepared using the following specific steps: A1. Add the fluorosilicone resin prepolymer to a four-necked flask, heat to 75-85℃, and stir for 30 min under nitrogen protection; add dropwise a mixed solution of dodecyl fluoroheptyl acrylate and azobisisobutyronitrile at a dropping rate of 2-3 ml / min, and keep the reaction at the temperature for 4-6 h after the addition is complete; then add dodecyl mercaptan, heat to 90-95℃ and continue the reaction for 1.5-2 h, cool to room temperature, and obtain the first modified fluorosilicone resin; A2. The first modified fluorosilicone resin and epichlorohydrin were added to a reaction vessel, cooled to 0-5℃, and boron trifluoride diethyl ether complex was slowly added dropwise. The mixture was stirred and reacted for 3-4 hours. The temperature was raised to 30-40℃, and 10% sodium hydroxide solution was added. The mixture was kept at this temperature for 2-3 hours and neutralized to pH 7-8. Unreacted epichlorohydrin and water were removed by vacuum distillation at -0.09MPa and 60-70℃ to obtain the second modified fluorosilicone resin. A3. Add the second modified fluorosilicone resin to the flask, add tetraethyl orthosilicate and silane coupling agent KH-560, and stir evenly; add dropwise a mixture of 0.5% hydrochloric acid solution and deionized water, heat to 50-60℃, and perform hydrolysis and condensation reaction for 5-7 hours; after the reaction is completed, degas under reduced pressure at -0.08MPa and 40-50℃ for 30 minutes to obtain the modified fluorosilicone resin.

3. The long-lasting weather-resistant and corrosion-resistant coating for photovoltaic module surfaces according to claim 1, characterized in that: The modified graphene oxide is prepared using the following specific steps: B1. Graphene oxide was dispersed in N,N-dimethylformamide and ultrasonically dispersed at 400W for 30 min to obtain a uniform dispersion. Ethylenediamine and triethylamine were added, and the mixture was heated to 80-90℃ and refluxed for 8-10 h. After the reaction was completed, the mixture was centrifuged, and the precipitate was washed 3-4 times with ethanol. It was then dried under vacuum of -0.1MPa and at 60-70℃ for 12 h to obtain the first modified graphene oxide. B2. The first-modified graphene oxide was dispersed in acetone and ultrasonically dispersed for 20 min. 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and benzoyl peroxide were added, the temperature was raised to 60-70℃, and the reaction was stirred for 6-8 h. The mixture was centrifuged, the precipitate was washed 2-3 times with acetone, and dried under vacuum of -0.1 MPa and temperature of 50-60℃ for 8 h to obtain the second-modified graphene oxide. B3. Disperse the second modified graphene oxide in an ethanol-water mixture with a volume ratio of 3:1 and ultrasonically disperse for 30 min; adjust the pH to 4-5 with a 1% acetic acid solution, add silane coupling agent KH-550, heat to 40-50℃, and stir for 4-6 h. Centrifugation was performed, the precipitate was washed with water until neutral, and then dried under vacuum of -0.1 MPa at 60-70℃ for 10 hours to obtain modified graphene oxide.

4. The long-lasting weather-resistant and corrosion-resistant coating for photovoltaic module surfaces according to claim 2, characterized in that: The ratio of fluorosilicone resin prepolymer, dodecafluoroheptyl acrylate, azobisisobutyronitrile, and dodecathiol in A1 is 100g: 30-40g: 0.8-1.2g: 0.3-0.5g; the number average molecular weight of the fluorosilicone resin prepolymer is 2000-3000. The ratio of the first modified fluorosilicone resin, epichlorohydrin, boron trifluoride diethyl ether complex, and sodium hydroxide solution in A2 is 100g: 15-20g: 0.5-1g: 5-8ml; The ratio of the second modified fluorosilicone resin, tetraethyl orthosilicate, silane coupling agent KH-560, hydrochloric acid solution, and deionized water in A3 is 100g: 8-12g: 3-5g: 1-2ml: 5-8ml.

5. The long-lasting weather-resistant and corrosion-resistant coating for photovoltaic module surfaces according to claim 3, characterized in that: The ratio of graphene oxide, N,N-dimethylformamide, ethylenediamine, and triethylamine in B1 is 10g:80-100ml:15-20g:2-3ml; The ratio of the first modified graphene oxide, acetone, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and benzoyl peroxide in B2 is 10g:50-60ml:8-12g:0.5-0.8g. The ratio of the second modified graphene oxide, ethanol-water mixture, and silane coupling agent KH-550 in B3 is 10g:40-50ml:5-8g.

6. The long-lasting weather-resistant and corrosion-resistant coating for photovoltaic module surfaces according to claim 1, characterized in that: The organosiloxane composite defoamer is composed of organosiloxane and polyether in a mass ratio of 3:1, with a defoaming speed ≤5s and a foam suppression time ≥24h; the isocyanate curing agent is hexamethylene diisocyanate trimer with an NCO content of 20-23% and a viscosity of 800-1200mPa・s at 25℃; the volume ratio of ethyl acetate to xylene in the ethyl acetate-xylene mixed solvent is 1:

1.

7. The long-lasting weather-resistant and corrosion-resistant coating for photovoltaic module surfaces according to claim 1, characterized in that: The mica powder is modified with a titanate coupling agent, and the specific method is as follows: Mica powder was placed in a high-speed mixer and heated to 80°C. It was then stirred and dehydrated for 30 minutes. Isopropoxytristearatetoxytitanate and anhydrous ethanol were added, and the mixture was stirred at 1000 r / min for 60 minutes. After cooling to room temperature, the mixture was discharged to obtain the titanate coupling agent modified mica powder.

8. The long-lasting weather-resistant and corrosion-resistant coating for photovoltaic module surfaces according to claim 7, characterized in that: When the mica powder is modified with a titanate coupling agent, the ratio of mica powder, isopropoxytristearatetoxytitanate, and anhydrous ethanol is 100g:2g:3ml.

9. A method for preparing a long-lasting weather-resistant and corrosion-resistant coating for the surface of a photovoltaic module, characterized in that: Specifically, it includes the following steps: S1. Add 5-10 parts of nano-silica, 3-8 parts of mica powder, and 0.5-2 parts of modified graphene oxide to 5-10 parts of ethyl acetate-xylene mixed solvent. Stir at 800-1000 r / min for 30 min, then ultrasonically disperse at 500 W and 25-30℃ for 60 min to obtain a functional filler dispersion. Add 0.1-0.3 parts of organosiloxane complex defoamer to the dispersion, continue stirring for 15 min, and let stand for 20 min to defoam. S2. Add 40-55 parts of modified fluorosilicone resin and 15-25 parts of epoxy resin to the reactor, heat to 50-60℃, and stir at 600-800 r / min for 90 min; add 0.5-1.5 parts of silane coupling agent KH-560, and continue stirring for 75-80 min; then add 2-2.5 parts of ultraviolet absorber UV-531, 1-1.5 parts of hindered amine light stabilizer, 0.5-1.5 parts of antioxidant 1010, 0.3-1 parts of polyether modified polysiloxane leveling agent, and 0.1-0.5 parts of organosiloxane complex defoamer, and continue stirring for 40 min to obtain the base material mixture system; S3. Slowly add the functional filler dispersion prepared in S1 to the base material mixing system in S2 while stirring at 800 r / min. After the addition is complete, continue stirring for 90 min. Transfer the mixture to a three-roll mill, control the roller temperature at 20-25℃, and grind 3-4 times with a roller speed ratio of 1:3:

5. The first roller speed is 50 r / min. Control the particle size of the system after grinding to ≤5μm to obtain the coating base material. S4. Cool the coating base to 25-30℃, add 8-15 parts of isocyanate curing agent, and slowly add 5-10 parts of ethyl acetate-xylene mixed solvent. Stir at 500-600 r / min for 30 min. After stirring, degas at a vacuum of -0.09 MPa and a temperature of 25-30℃ for 40 min, and then pass through a 200-mesh sieve to obtain a long-lasting weather-resistant and corrosion-resistant coating for the photovoltaic module surface.

10. The method for preparing a long-lasting weather-resistant and corrosion-resistant coating for the surface of a photovoltaic module according to claim 9, characterized in that: The ultrasonic dispersion process in S1 adopts an intermittent ultrasonic mode, that is, ultrasonic work for 5 minutes, pause for 2 minutes, and repeat until the cumulative ultrasonic time reaches 60 minutes.