Scratch-resistant coating solution for photovoltaic modules and method for preparing same

Abstract

The application discloses a kind of photovoltaic module scratch-resistant coating liquid and preparation method thereof, it is related to coating liquid technical field.The photovoltaic module scratch-resistant coating liquid includes the following weight parts raw materials: 18-25 parts methyl isobutyl ketone, 8-12 parts isopropanol, 3-6 parts propylene glycol methyl ether acetate, 2-4 parts dipropylene glycol methyl ether, 15-22 parts modified epoxy resin, 3-5 parts silane coupling agent KH-550, 25-35 parts modified nanometer silica sol, 1-2.5 parts nanometer zirconium oxide, 2-4 parts nanometer aluminum nitride powder, 0.8-1.5 parts polyoxyethylene fatty ether phosphate, 0.5-1.2 parts ultraviolet absorber UV-327, 0.2-0.5 parts antioxidant 1010, 1.5-3 parts polydimethylsiloxane, 0.1-0.3 parts silicone leveling agent, 0.3-0.6 parts dibutyltin dilaurate.The photovoltaic module scratch-resistant coating liquid uses high hardness and stability raw materials, with strong adaptability of dispersing agent, effectively avoids organic base film layer aging problem, fine preparation operation improves material dispersibility, finally film scratch-resistant ability and weather resistance are strong, can long-term adapt to complex environment, guarantee component light transmittance and power generation stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coating liquid, in particular to a kind of photovoltaic module scratch-resistant coating liquid and preparation method thereof. BACKGROUND

[0002] As the core component of solar power generation system, photovoltaic module is exposed to outdoor complex environment for a long time. Its surface glass cover plate is easily affected by wind and sand scouring, hail impact, bird excrement corrosion and human wiping, resulting in scratches and damage. Such damage can significantly reduce the cover plate light transmittance, leading to the decrease of photovoltaic module photoelectric conversion efficiency, while damaging the surface protective layer, accelerating the aging and decay of internal battery piece, shortening the overall service life of photovoltaic module and increasing the operation and maintenance cost.

[0003] Currently, the industry improves the scratch resistance by coating a coating liquid on the surface of photovoltaic glass. The existing coating liquid mainly uses organic resins such as epoxy resin and acrylic resin as base material, and compounding inorganic particles such as nano-silicon dioxide and titanium dioxide to enhance hardness. However, the traditional formula has obvious technical pain points: some use anatase or unmodified rutile type nano-titanium dioxide, which can give certain self-cleaning properties, but due to the photocatalytic activity under ultraviolet irradiation, the organic base material is degraded, resulting in film layer powdering and yellowing; nano-particles are easy to agglomerate, resulting in poor film layer uniformity and uneven scratch resistance; the solvent has poor volatility rate matching, and defects such as shrinkage hole and orange peel are easy to occur during film forming process, affecting light transmittance and appearance; the film layer has poor adhesion to glass substrate, and is easy to peel off during long-term outdoor use, which is difficult to continuously play the protection role.

[0004] In addition, the existing coating liquid preparation process lacks fine control, such as insufficient raw material pretreatment, and rough control of feeding and reaction temperature, which further leads to low product performance stability, and is difficult to meet the stringent requirements of weather resistance, scratch resistance and light transmittance for long-term outdoor use of photovoltaic module. Therefore, it has become an urgent problem for the industry to develop a photovoltaic module scratch-resistant coating liquid with no risk, high stability and adaptation to outdoor environment. SUMMARY

[0005] In view of the shortcomings of the prior art, the present application provides a photovoltaic module scratch-resistant coating liquid and a preparation method thereof, which solves the problems of photocatalytic degradation of the film layer, nano-particle agglomeration defects and insufficient weather resistance of the film layer.

[0006] To achieve the above purpose, the present application is realized by the following technical scheme:

[0007] The scratch-resistant coating solution for photovoltaic modules comprises the following raw materials in parts by weight: 18-25 parts of methyl isobutyl ketone, 8-12 parts of isopropyl alcohol, 3-6 parts of propylene glycol methyl ether acetate, 2-4 parts of dipropylene glycol methyl ether, 15-22 parts of modified epoxy resin, 3-5 parts of silane coupling agent KH-550, 25-35 parts of modified nano-silica sol, 1-2.5 parts of nano-zirconium oxide, 2-4 parts of nano-aluminum nitride powder, 0.8-1.5 parts of polyoxyethylene fatty ether phosphate, 0.5-1.2 parts of ultraviolet absorber UV-327, 0.2-0.5 parts of antioxidant 1010, 1.5-3 parts of polydimethylsiloxane, 0.1-0.3 parts of silicone leveling agent, and 0.3-0.6 parts of dibutyltin dilaurate.

[0008] Further, the nano-zirconium oxide is surface-pre-treated nano-zirconium oxide, and the pre-treatment step is as follows: untreated nano-zirconium oxide powder is added into 4 times of mass of anhydrous ethanol, ultrasonic dispersion is carried out at a power of 250 W for 30 min, then 2% of silane coupling agent KH-570 by mass of the nano-zirconium oxide is added, reaction is carried out at 60°C under stirring at a speed of 400 r / min for 2 h, after the reaction, centrifugal separation is carried out, the precipitate is collected and vacuum dried at 90°C for 3 h to obtain the nano-zirconium oxide. The ultrasonic dispersion of anhydrous ethanol removes the impurities on the surface of the nano-zirconium oxide and reduces the agglomeration tendency; the silane coupling agent KH-570 grafting modification enhances the compatibility with the organic resin; the stirring at 60°C and 400 r / min ensures sufficient reaction, and the vacuum drying at 90°C avoids secondary pollution, finally making the nano-zirconium oxide dispersed stably in the coating solution, no obvious agglomeration after standing for 72 h, and the film layer after film forming is uniform in improving the hardness and light transmittance.

[0009] Further, the nano-aluminum nitride powder is coated and modified nano-aluminum nitride, and the coating and modification step is as follows: untreated nano-aluminum nitride powder is dispersed in 5 times of mass of deionized water to prepare a suspension, 6% of trisodium citrate by mass of the aluminum nitride is added as a dispersant, and ultrasonic treatment is carried out at a power of 350 W for 40 min; then the temperature is raised to 65°C, 15% of sodium silicate solution with a mass fraction of 10% by mass of the aluminum nitride is added dropwise, after the dropwise addition is completed, dilute nitric acid is used to adjust the pH to 6, and the temperature is kept and stirred for 2.5 h; after the reaction, centrifugal separation is carried out, the precipitate is washed with deionized water for 4 times, and dried at 110°C for 5 h to obtain the nano-aluminum nitride powder. The trisodium citrate and 350 W ultrasonic cooperate to inhibit the agglomeration of the nano-aluminum nitride; the sodium silicate coating forms a silica protective layer to isolate the nano-aluminum nitride from the organic phase; the temperature keeping at 65°C and the pH=6 control promote the coating reaction to be sufficient; the drying at 110°C removes the water, which not only retains more than 90% of the thermal conductivity of the nano-aluminum nitride, but also improves the compatibility of the nano-aluminum nitride in the coating solution, avoiding the decrease of the light transmittance of the film layer.

[0010] Further, the modified epoxy resin is prepared according to the following specific preparation steps:

[0011] A1, take the bisphenol A type epoxy resin into methyl isobutyl ketone, 200-300 r / min stirring to 90-95℃, then slowly add adipic acid and p-toluene sulfonic acid, to 110-120℃, keep the temperature for 4-5h; every 1h sample detection of acid value, when the acid value is reduced to 10-15mgKOH / g, stop the reaction, after cooling to 60-70℃, add isopropanol dilution, get the first modified carboxylated epoxy resin;

[0012] A2, take the first modified carboxylated epoxy resin to 80-85℃, add silane coupling agent KH-550 and deionized water, 400-500 r / min stirring, then add antioxidant 1010 and dibutyltin dilaurate, continue to keep the temperature and stirring rate, keep the temperature for 3-4h; during the period, the intensity change of siloxane characteristic peak 1080cm⁻¹ is monitored by Fourier infrared spectrum, until the peak intensity is stable, the reaction is completed, add propylene glycol methyl ether acetate dilution, cooling to 50-55℃, get the second modified siloxane crosslinking epoxy resin;

[0013] A3, take the second modified siloxane crosslinking epoxy resin into untreated nano zirconium oxide and polydimethylsiloxane, 8000-10000 r / min high speed shearing dispersion treatment for 30-45min, then into the ball mill, the medium is 5mm diameter agate, ball to material ratio 8:1, ball milling 2-3h, to ensure the uniform dispersion of nano zirconium oxide; after ball milling, heating to 70-75℃, add ultraviolet absorber UV-327, stirring for 1-1.5h, then cooling to room temperature, filter through 1μm filter membrane, get the modified epoxy resin.

[0014] Further, the amount of bisphenol A type epoxy resin, methyl isobutyl ketone, adipic acid, p-toluene sulfonic acid, isopropanol in A1 is 300-350g: 150-180mL: 25-30g: 0.5-1g: 30-40mL; stirring to make the epoxy resin dissolved in methyl isobutyl ketone, 90-95℃ to help adipic acid and epoxy group ring opening, p-toluene sulfonic acid catalytic acceleration reaction, introduce carboxyl group in the resin chain. 110-120℃ for 4-5h, control the amount of carboxyl group by acid value 10-15mgKOH / g, cooling and dilution with isopropanol, improve the reactivity of resin, lay the foundation for subsequent crosslinking.

[0015] Further, the first modified carboxylated epoxy resin in A2, silane coupling agent KH-550, deionized water, antioxidant 1010, dibutyltin dilaurate, propylene glycol methyl ether acetate are in a ratio of 200-250g: 10-15g: 5-8mL: 0.8-1.2g: 1-1.5g: 20-25mL; the silane coupling agent KH-550 is hydrolyzed to form a silicon hydroxyl group, which is condensed with the carboxyl group of the resin to form a Si-O-C bond, and the silicon hydroxyl group is self-condensed to form a Si-O-Si crosslinking network. Dibutyltin dilaurate catalyzes the reaction, antioxidant 1010 prevents the oxidation of the resin, and 3-4h of heat preservation allows the crosslinking to be fully completed, improving the weather resistance and inorganic particle compatibility of the resin and reducing the interfacial stress.

[0016] Further, the second modified siloxane crosslinking epoxy resin in A3, nano zirconium oxide, polydimethylsiloxane, and ultraviolet absorber UV-327 are in a ratio of 180-220g: 8-12g: 2-3g: 1-2g. Shearing and ball milling are used to disperse the nano zirconium oxide uniformly in the resin, and the nano reinforcement effect is used to improve the hardness. Polydimethylsiloxane improves the flowability of the resin, and 70-75°C promotes the dissolution and dispersion of the ultraviolet absorber UV-327 to resist ultraviolet light. A 1μm filter membrane is used to filter out impurities, ensuring the purity and comprehensive performance of the resin.

[0017] Further, the modified nano silica sol is prepared according to the following specific steps:

[0018] B1. Take a nano silica sol with a solid content of 30%, dilute it with isopropyl alcohol, stir at 300-400r / min, and heat it to 50-60℃. Then slowly add a mixture of silane coupling agent KH-560 and deionized water, and control the dropwise addition time to be 60-90min. After the dropwise addition is complete, heat it to 70-75℃, and keep it at this temperature for 3-4h. During this period, take samples every 30min to detect the change in particle size until the particle size stabilizes at 15-20nm. After the reaction is complete, cool it to room temperature, and remove 10-15% of the solvent by distillation under reduced pressure to obtain the first modified nano silica sol.

[0019] B2. Take the first modified nano silica sol, add the modified epoxy resin mentioned above, stir at 500-600r / min, and heat it to 80-85℃. Then add dibutyltin dilaurate, and dropwise add ethanolamine to adjust the pH to 7-8. After that, keep it at this temperature for 5-6h. During this period, monitor the change in the intensity of the characteristic peak of the epoxy group at 910cm⁻¹ by Fourier infrared spectroscopy until the peak intensity decreases by 80%. After the reaction is complete, dilute it with propylene glycol methyl ether acetate, and cool it to 40-45℃ to obtain the second modified nano silica sol.

[0020] B3, the second time modified nano-silica sol is added to the untreated nano-aluminum nitride powder, then polyoxyethylene fatty ether phosphate is added, and power 300 w ultrasonic dispersion treatment is performed for 60-90 min, during which the stirring is stopped every 20 min for 10 min to prevent local overheating; after the dispersion is completed, cooling is performed to room temperature, ultraviolet absorber UV-327 is added, and 300-400 r / min continuous stirring is performed for 40-60 min until uniform dispersion; cooling is performed to room temperature, filtration is performed using a 1 μm filter membrane, and modified nano-silica sol is obtained.

[0021] Further, the amount ratio of the nano-silica sol, isopropyl alcohol, silane coupling agent KH-560, and deionized water in B1 is 400-500 g: 200-250 mL: 15-20 g: 10-15 mL; isopropyl alcohol is used to reduce the interparticle force, and 300-400 r / min stirring and 50-60℃ are used to create conditions for the reaction. The alkoxy of the silane coupling agent KH-560 is hydrolyzed to generate silicon hydroxyl, which is dehydrated and condensed with the surface silicon hydroxyl of the nano-silica to form a Si-O-Si bond, the silane coupling agent KH-560 is grafted on the particle surface, and the epoxy group is retained. 70-75℃ is used for heat preservation for 3-4 h to ensure that the reaction is complete, the compatibility with the resin is improved by introducing an organic functional group, the particle size is stabilized at 15-20 nm, and agglomeration is avoided.

[0022] Further, the amount ratio of the first time modified nano-silica sol, modified epoxy resin, dibutyltin dilaurate, and propylene glycol methyl ether acetate in B2 is 300-350 g: 80-100 g: 2-3 g: 50-60 mL; stirring is used to mix the sol and the modified epoxy resin sufficiently, 80-85℃ is used with dibutyltin dilaurate to catalyze, and the ring-opening reaction of the carboxyl and hydroxyl groups in the resin with the epoxy groups on the surface of the sol is promoted to form ester bonds and ether bonds. Ethanolamine is used to adjust the pH to 7-8 to optimize the reaction environment, and heat preservation is performed for 5-6 h to allow the reaction rate of the epoxy groups to reach 80%, realize the chemical grafting of the two, and enhance the hardness and anti-delamination ability of the subsequent film layer.

[0023] Further, the amount ratio of the second time modified nano-silica sol, nano-aluminum nitride powder, polyoxyethylene fatty ether phosphate, and ultraviolet absorber UV-327 in B3 is 250-300 g: 15-20 g: 3-5 g: 2-3 g; polyoxyethylene fatty ether phosphate prevents agglomeration through electrostatic and steric hindrance effects, aluminum nitride and the residual hydroxyl groups of the sol weakly interact to realize combination, and the sol is given heat conductivity. The ultraviolet absorber UV-327 is added at room temperature and stirred to make it uniformly dispersed to absorb ultraviolet light and resist aging, and 1 μm filter membrane filtration is performed to remove impurities and protect the performance and purity of the sol.

[0024] A preparation method of a photovoltaic module anti-scratch coating solution, specifically comprising the following steps:

[0025] S1, add methyl isobutyl ketone, isopropyl alcohol, propylene glycol methyl ether acetate and dipropylene glycol methyl ether into a three-necked flask, stir at a rate of 200-300 r / min, mix at room temperature for 15-20 min to form a mixed solvent; mixing at room temperature avoids abnormal solvent evaporation rate, and the formed mixed solvent can accurately adjust the viscosity and volatilization gradient of the subsequent system, laying a foundation for raw material dissolution and film uniformity;

[0026] S2, slowly add the modified epoxy resin into the mixed solvent, increase the stirring rate to 400-500 r / min and heat to 50-55 DEG C, and keep stirring for 30-40 min until the resin is completely dissolved; then add the silane coupling agent KH-550, continue stirring for 20-30 min to form a premix;

[0027] S3, add the modified nano-silica sol, nano-zirconium oxide and nano-aluminum nitride powder into the premix in sequence, adjust the stirring rate to 600-700 r / min, and stir at room temperature for 1-1.5 h to prevent particle agglomeration caused by high temperature; then add the polyoxyethylene fatty ether phosphate, continue stirring for 30-45 min to further inhibit particle agglomeration, ensure uniform dispersion of the nano-particles in the premix, and guarantee stable film layer performance;

[0028] S4, add the ultraviolet absorber UV-327, antioxidant 1010, polydimethylsiloxane and silicone leveling agent into the system, reduce the stirring rate to 300-400 r / min, heat to 60-65 DEG C, and keep stirring for 40-50 min to ensure uniform dispersion of the additives; the ultraviolet absorber UV-327 and the antioxidant 1010 endow the system with anti-aging ability, and the polydimethylsiloxane and the silicone leveling agent optimize the hydrophobic and flat properties of the film surface;

[0029] S5, add dibutyltin dilaurate again, maintain the stirring rate at 300-400 r / min, heat to 70-75 DEG C, and keep reacting for 1-1.5 h; after the reaction is completed, sample detection at 25 DEG C shows that the viscosity is 200-300 mPa・s, and after the viscosity is qualified, the system is cooled to room temperature, and filtered under reduced pressure using a 1 mu m organic filter membrane; after filtration, the film coating solution is transferred into a sealed container, and is placed at 25 DEG C in the dark for aging for 24-36 h to obtain the photovoltaic module scratch-resistant film coating solution.

[0030] Further, in S5, if the viscosity is too high, an appropriate amount of methyl isobutyl ketone is added for adjustment, and if the viscosity is too low, a small amount of solvent is removed by reduced pressure distillation, so as to avoid film coating difficulty caused by too high viscosity, too thick film layer caused by too high viscosity, or too thin film layer and poor uniformity caused by too low viscosity, and ensure stable film coating process and film layer performance up to standard.

[0031] The application provides a photovoltaic module scratch-resistant film coating solution and a preparation method thereof, and has the following beneficial effects:

[0032] 1、The application discards the traditional raw materials that can easily cause photocatalysis problem, selects modified nano zirconium oxide without photocatalytic activity, and modifies nano aluminum nitride with silicon dioxide coating, simultaneously, pre-treats nano zirconium oxide with silane coupling agent, and modifies nano silicon dioxide sol with three times of grafting and compounding, so as to build a stable interface bonding structure of inorganic particles and organic resin. The multi-component synergistic modification design completely cuts off the contact path of photocatalytic components and organic base material, avoids the degradation of organic resin under ultraviolet irradiation, ensures the structural integrity of the film layer in long-term outdoor use, and prolongs the surface protection period of the photovoltaic module.

[0033] 2、The application forms a systematic dispersion control scheme from raw material pre-treatment to preparation process, the raw material end is modified by polyoxyethylene fatty ether phosphate dispersant in combination with nano particles, so as to reduce the particle surface energy and agglomeration tendency; in the preparation process, modified nano silicon dioxide sol, nano zirconium oxide and nano aluminum nitride powder are sequentially added in gradient feeding mode, combined with segmented temperature control stirring and ultrasonic dispersion-ball milling combined process, so that nano particles with different densities and surface properties are uniformly dispersed in the organic resin matrix, avoiding the local particle enrichment or vacancy leading to uneven film layer hardness and light transmittance fluctuation, finally forming a structure uniform coating layer with high hardness and high light transmittance, which meets the anti-scratch requirement and does not affect the photoelectric conversion efficiency of the photovoltaic module.

[0034] 3、The application builds a strong adhesion system through the synergistic effect of modified epoxy resin and modified nano silicon dioxide sol, the modified epoxy resin is modified by carboxylation and siloxane crosslinking, more active groups are introduced into the molecular chain, which can form multiple chemical bond with the silicon hydroxyl group and silane coupling agent group on the surface of modified nano silicon dioxide sol, and at the same time, silane coupling agent KH-550 acts as a bridge to further strengthen the interfacial bonding force between inorganic particles, organic resin and photovoltaic glass substrate; in addition, the formula is compounded with ultraviolet absorber UV-327 and antioxidant 1010, the former absorbs outdoor ultraviolet rays, and the latter inhibits the oxidative degradation of the resin, combined with high stability inorganic particles, so that the film layer has excellent salt mist resistance and wind and sand scouring resistance, can resist the influence of complex environmental factors such as outdoor temperature and humidity changes, acid and alkali corrosion, reduces the risk of film layer peeling and cracking, and ensures long-term protection effect.

[0035] 4、The application improves the film forming quality through the synergistic regulation of the solvent system and the preparation process, the solvent end adopts a compound system of methyl isobutyl ketone, isopropyl alcohol, propylene glycol methyl ether acetate and dipropylene glycol methyl ether, the volatilization gradient difference of different boiling point solvents is utilized to avoid bubbles and shrinkage holes generated in the film forming process due to rapid volatilization of the solvent; meanwhile, a polyether modified polydimethylsiloxane organic silicone leveling agent is added to cooperate with polydimethylsiloxane to reduce the surface tension of the film layer, improve the liquid flowability, and reduce appearance defects such as orange peel and pinholes in the film forming process; in the preparation process, the aging treatment is used to fully crosslink the unreacted monomers, further eliminate the micro-bubbles in the system, and finally form a film layer with smooth surface and no obvious defects, which not only improves the appearance consistency of the photovoltaic module, but also avoids the defects from becoming weak points of corrosion and scratches, further prolongs the service life of the film layer. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0037] Embodiment 1, a photovoltaic module anti-scratch coating solution is prepared, and the specific preparation steps are as follows:

[0038] S1, 18 parts of methyl isobutyl ketone, 8 parts of isopropyl alcohol, 3 parts of propylene glycol methyl ether acetate and 2 parts of dipropylene glycol methyl ether are added into a three-necked flask, the stirring rate is 200 r / min, and the mixture is mixed at room temperature for 15 min to form a mixed solvent;

[0039] S2, 15 parts of epoxy resin are slowly added into the above-mentioned mixed solvent, the stirring rate is increased to 400 r / min and the temperature is increased to 50 DEG C, and the stirring is kept for 30 min until the resin is completely dissolved; then 3 parts of silane coupling agent KH-550 are added, and the stirring is continued for 20 min to form a premix;

[0040] S3, 25 parts of nano-silica sol, 1 part of nano-zirconia and 2 parts of nano-aluminum nitride powder are sequentially added into the premix, the stirring rate is adjusted to 600 r / min, and the stirring is kept at room temperature for 1 h; then 0.8 parts of polyoxyethylene fatty ether phosphate ester are added, and the stirring is continued for 30 min;

[0041] S4, 0.5 parts of ultraviolet absorber UV-327, 0.2 parts of antioxidant 1010, 1.5 parts of polydimethylsiloxane and 0.1 parts of organic silicone leveling agent are added into the system, the stirring rate is reduced to 300 r / min and the temperature is increased to 60 DEG C, and the stirring is kept for 40 min to ensure that the additives are uniformly dispersed;

[0042] S5, add 0.3 parts of dibutyltin dilaurate again, maintain the stirring rate at 300 r / min, and heat to 70°C, and keep the reaction for 1 h; after the reaction is completed, take a sample for detection, and the viscosity at 25°C is 200 mPa·s; after the viscosity is qualified, cool the system to room temperature, and perform reduced-pressure filtration using a 1 μm organic filter membrane; after filtration, transfer the coating solution into a sealed container, and keep it standing and aging for 24 h at 25°C under light-proof conditions, to obtain the anti-scratch coating solution for photovoltaic modules.

[0043] Example 2, preparation of an anti-scratch coating solution for photovoltaic modules, and the specific preparation steps are as follows:

[0044] S1, add 25 parts of methyl isobutyl ketone, 12 parts of isopropyl alcohol, 6 parts of propylene glycol methyl ether acetate, and 4 parts of dipropylene glycol methyl ether into a three-necked flask, mix at a stirring rate of 300 r / min for 20 min at room temperature, and form a mixed solvent;

[0045] S2, slowly add 22 parts of epoxy resin into the mixed solvent, increase the stirring rate to 500 r / min, heat to 55°C, and keep stirring for 40 min until the resin is completely dissolved; then add 5 parts of silane coupling agent KH-550, and continue stirring for 30 min to form a premix;

[0046] S3, add 35 parts of nano-silica sol, 2.5 parts of nano-zirconia, and 4 parts of nano-aluminum nitride powder into the premix in sequence, adjust the stirring rate to 700 r / min, and stir at room temperature for 1.5 h; then add 1.5 parts of polyoxyethylene fatty ether phosphate, and continue stirring for 45 min;

[0047] S4, add 1.2 parts of ultraviolet absorber UV-327, 0.5 parts of antioxidant 1010, 3 parts of polydimethylsiloxane, and 0.3 parts of silicone leveling agent into the system, reduce the stirring rate to 400 r / min, heat to 65°C, and keep stirring for 50 min to ensure that the additives are uniformly dispersed;

[0048] S5, add 0.6 parts of dibutyltin dilaurate again, maintain the stirring rate at 400 r / min, heat to 75°C, and keep the reaction for 1.5 h; after the reaction is completed, take a sample for detection, and the viscosity at 25°C is 300 mPa·s; after the viscosity is qualified, cool the system to room temperature, and perform reduced-pressure filtration using a 1 μm organic filter membrane; after filtration, transfer the coating solution into a sealed container, and keep it standing and aging for 36 h at 25°C under light-proof conditions, to obtain the anti-scratch coating solution for photovoltaic modules.

[0049] Example 3, preparation of an anti-scratch coating solution for photovoltaic modules, and the specific preparation steps are as follows:

[0050] S1, in a three-necked flask, 21 parts of methyl isobutyl ketone, 10 parts of isopropyl alcohol, 4 parts of propylene glycol methyl ether acetate and 3 parts of dipropylene glycol methyl ether were added, the stirring rate was 250 r / min, and the mixture was mixed at room temperature for 17 min to form a mixed solvent;

[0051] S2, 18 parts of epoxy resin were slowly added to the above-mentioned mixed solvent, the stirring rate was increased to 450 r / min and the temperature was increased to 52°C, and the mixture was stirred for 35 min until the resin was completely dissolved; then 4 parts of silane coupling agent KH-550 were added, and the stirring was continued for 25 min to form a premix;

[0052] S3, 30 parts of nano-silica sol, 1.5 parts of nano-zirconia, and 3 parts of nano-aluminum nitride powder were added to the premix in turn, the stirring rate was adjusted to 650 r / min, and the mixture was stirred at room temperature for 1.2 h; then 1 part of polyoxyethylene fatty ether phosphate was added, and the stirring was continued for 38 min;

[0053] S4, 0.8 parts of ultraviolet absorber UV-327, 0.3 parts of antioxidant 1010, 2 parts of polydimethylsiloxane and 0.2 parts of silicone leveling agent were added to the system, the stirring rate was reduced to 350 r / min and the temperature was increased to 62°C, and the mixture was stirred for 45 min to ensure uniform dispersion of the additives;

[0054] S5, 0.4 parts of dibutyltin dilaurate was added, the stirring rate was maintained at 350 r / min, the temperature was increased to 72°C, and the reaction was carried out for 1.2 h; after the reaction was completed, the viscosity at 25°C was detected to be 250 mPa・s, and after the viscosity was qualified, the system was cooled to room temperature, and filtered under reduced pressure using a 1 μm organic filter membrane; after filtration, the coating solution was transferred to a sealed container, and was allowed to stand and age at 25°C in the dark for 30 h to obtain a photovoltaic module scratch-resistant coating solution.

[0055] Example 4, a modified epoxy resin was prepared, and the specific preparation steps were as follows:

[0056] A1, 300 g of bisphenol A type epoxy resin was added to 150 mL of methyl isobutyl ketone, and stirred at 200 r / min and heated to 90°C, then 25 g of adipic acid and 0.5 g of p-toluenesulfonic acid were slowly added, and the temperature was increased to 110°C, and the reaction was carried out for 4 h; every 1 h, the acid value was detected, and when the acid value was reduced to 10 mgKOH / g, the reaction was stopped, and then the temperature was reduced to 60°C, and 30 mL of isopropyl alcohol was added for dilution to obtain a first modified carboxylated epoxy resin;

[0057] A2, take 200 g of the first modified carboxylated epoxy resin to 80 °C, add 10 g of silane coupling agent KH-550 and 5 mL of deionized water, 400 r / min stirring, then add 0.8 g of antioxidant 1010 and 1 g of dibutyltin dilaurate, continue to keep the temperature and stirring rate, keep the reaction for 3 h; during the reaction, the intensity change of siloxane characteristic peak 1080 cm⁻¹ is monitored by Fourier infrared spectrum until the peak intensity is stable, the reaction is completed, 20 mL of propylene glycol methyl ether acetate is added for dilution, and the temperature is cooled to 50 °C to obtain the second modified siloxane crosslinked epoxy resin;

[0058] A3, take 180 g of the second modified siloxane crosslinked epoxy resin, add 8 g of untreated nano zirconium oxide and 2 g of polydimethylsiloxane, and disperse at 8000 r / min for 30 min, then transfer into a ball mill, the medium is 5 mm maroon ball, the ball to material ratio is 8:1, and the ball milling is carried out for 2 h to ensure the uniform dispersion of nano zirconium oxide; after the ball milling is completed, the temperature is increased to 70 °C, 1 g of ultraviolet absorber UV-327 is added, stirred for 1 h, then cooled to room temperature, filtered through a 1 μm filter membrane, and the modified epoxy resin is obtained.

[0059] Example 5, the modified epoxy resin is prepared, and the specific preparation steps are as follows:

[0060] A1, take 350 g of bisphenol A type epoxy resin, add 180 mL of methyl isobutyl ketone, and stir at 300 r / min to increase the temperature to 95 °C, then slowly add 30 g of adipic acid and 1 g of p-toluenesulfonic acid, increase the temperature to 120 °C, and keep the reaction for 5 h; every 1 h, take a sample to detect the acid value, when the acid value is reduced to 15 mgKOH / g, stop the reaction, then cool to 70 °C, add 40 mL of isopropyl alcohol for dilution, and obtain the first modified carboxylated epoxy resin;

[0061] A2, take 250 g of the first modified carboxylated epoxy resin to 85 °C, add 15 g of silane coupling agent KH-550 and 8 mL of deionized water, 500 r / min stirring, then add 1.2 g of antioxidant 1010 and 1.5 g of dibutyltin dilaurate, continue to keep the temperature and stirring rate, keep the reaction for 4 h; during the reaction, the intensity change of siloxane characteristic peak 1080 cm⁻¹ is monitored by Fourier infrared spectrum until the peak intensity is stable, the reaction is completed, 25 mL of propylene glycol methyl ether acetate is added for dilution, and the temperature is cooled to 55 °C to obtain the second modified siloxane crosslinked epoxy resin;

[0062] A3, take 220 g of the second modified siloxane crosslinked epoxy resin, add 12 g of untreated nano zirconium oxide and 3 g of polydimethylsiloxane, disperse at high speed for 45 min, then transfer to a ball mill, the medium is 5 mm diameter agate, the ball to material ratio is 8:1, ball mill for 3 h to ensure uniform dispersion of nano zirconium oxide; after ball milling, heat to 75℃, add 2 g of ultraviolet absorber UV-327, stir for 1.5 h, then cool to room temperature, filter through a 1 μm filter membrane to obtain a modified epoxy resin.

[0063] Example 6, preparation of modified nano-silica sol, the specific preparation steps are as follows:

[0064] B1, take 400 g of nano-silica sol with a solid content of 30%, dilute with 200 mL of isopropyl alcohol, stir at 300 r / min and heat to 50℃, then slowly add 15 g of silane coupling agent KH-560 and 10 mL of deionized water, the dropwise addition time is controlled within 60 min; after the dropwise addition is completed, heat to 70℃ and react for 3 h, take samples every 30 min to detect the particle size change during the reaction, until the particle size is stable at 15 nm; after the reaction is completed, cool to room temperature, remove 10% of the solvent by distillation under reduced pressure to obtain a first modified nano-silica sol;

[0065] B2, take 300 g of the first modified nano-silica sol, add 80 g of the modified epoxy resin prepared in Example 4, stir at 500 r / min and heat to 80℃, then add 2 g of dibutyltin dilaurate and dropwise add ethanolamine to adjust the pH to 7, then react for 5 h, during which the intensity change of the characteristic peak of epoxy group at 910 cm⁻¹ is monitored by Fourier infrared spectrum until the peak intensity decreases by 80%, after the reaction is completed, dilute with 50 mL of propylene glycol methyl ether acetate, cool to 40℃ to obtain a second modified nano-silica sol;

[0066] B3, take 250 g of the second modified nano-silica sol, add 15 g of untreated nano-aluminum nitride powder, then add 3 g of polyoxyethylene fatty ether phosphate, disperse by ultrasonic at a power of 300 w for 60 min, stop stirring every 20 min for 10 min during the dispersion to prevent local overheating; after the dispersion is completed, cool to room temperature, add 2 g of ultraviolet absorber UV-327, continuously stir at 300 r / min for 40 min until uniform dispersion; cool to room temperature, filter through a 1 μm filter membrane to obtain a modified nano-silica sol.

[0067] Example 7, preparation of modified nano-silica sol, the specific preparation steps are as follows:

[0068] B1, take 500 g of nano-silica sol with a solid content of 30%, dilute with 250 mL of isopropyl alcohol, stir at 400 r / min, and heat to 60°C. Then slowly add a mixture of 20 g of silane coupling agent KH-560 and 15 mL of deionized water, and control the dropwise addition time to be 90 min. After the dropwise addition is complete, heat to 75°C, and keep the temperature for 4 h. During this time, take samples every 30 min to detect changes in particle size until the particle size stabilizes at 20 nm. After the reaction is complete, cool to room temperature, and remove 15% of the solvent by distillation under reduced pressure to obtain the first modified nano-silica sol.

[0069] B2, take 350 g of the first modified nano-silica sol, add 100 g of the modified epoxy resin prepared in Example 4, stir at 600 r / min, and heat to 85°C. Then add 3 g of dibutyltin dilaurate, and add ethanolamine dropwise to adjust the pH to 8. After that, keep the temperature for 6 h. During this time, monitor the intensity change of the epoxy group characteristic peak at 910 cm⁻¹ by Fourier infrared spectroscopy until the peak intensity decreases by 80%. After the reaction is complete, dilute with 60 mL of propylene glycol methyl ether acetate, and cool to 45°C to obtain the second modified nano-silica sol.

[0070] B3, take 300 g of the second modified nano-silica sol, add 20 g of untreated nano-aluminum nitride powder, and then add 5 g of polyoxyethylene fatty ether phosphate. Ultrasonic dispersion treatment is performed at a power of 300 W for 90 min, with a 10 min stirring interval every 20 min to prevent local overheating. After the dispersion is complete, cool to room temperature, add 3 g of ultraviolet absorber UV-327, and continuously stir at 400 r / min for 60 min until uniform dispersion is achieved. Cool to room temperature, filter using a 1 μm filter membrane, and obtain the modified nano-silica sol.

[0071] Example 8, the nano-zirconia is prepared, and the specific preparation steps are as follows:

[0072] Take 100 g of untreated nano-zirconia powder, add 400 g of anhydrous ethanol, and ultrasonic dispersion is performed at a power of 250 W for 30 min. Then add 2 g of silane coupling agent KH-570, and react at 60°C under stirring at 400 r / min for 2 h. After the reaction is complete, centrifugal separation is performed, the precipitate is collected, and vacuum drying is performed at 90°C for 3 h to obtain the nano-zirconia.

[0073] Example 9, the aluminum nitride powder is prepared, and the specific preparation steps are as follows:

[0074] 100g untreated nano-aluminum nitride powder was dispersed in 500g deionized water to form a suspension, 6g trisodium citrate was added as a dispersant, and ultrasonic treatment was performed at a power of 350W for 40min; then the temperature was raised to 65℃, 15g of a 10% mass fraction sodium silicate solution was added dropwise, after the dropwise addition was completed, dilute nitric acid was used to adjust the pH to 6, and the mixture was stirred and kept at temperature for 2.5h; after the reaction was completed, centrifugal separation was performed, the precipitate was washed with deionized water 4 times, and drying was performed at 110℃ for 5h to obtain the nano-aluminum nitride powder.

[0075] Comparative Example 1: A photovoltaic module scratch-resistant coating solution was prepared according to the following steps:

[0076] The remaining steps were unchanged, except that the epoxy resin of Example 3 was replaced with the modified epoxy resin prepared in Example 4, to obtain a photovoltaic module scratch-resistant coating solution.

[0077] Comparative Example 2: A photovoltaic module scratch-resistant coating solution was prepared according to the following steps:

[0078] The remaining steps were unchanged, except that the nano-silica sol of Example 3 was replaced with the modified nano-silica sol prepared in Example 7, to obtain a photovoltaic module scratch-resistant coating solution.

[0079] Comparative Example 3: A photovoltaic module scratch-resistant coating solution was prepared according to the following steps:

[0080] The remaining steps were unchanged, except that the epoxy resin of Example 3 was replaced with the modified epoxy resin prepared in Example 4, and the nano-silica sol was replaced with the modified nano-silica sol prepared in Example 7, to obtain a photovoltaic module scratch-resistant coating solution.

[0081]

[0082] The performance test results showed that in terms of light transmittance (400-800nm), Examples 1-3 were 88.2%-90.8%, and Comparative Examples 1-3 were improved to 91.5%-93.3%; in terms of hardness, Examples 1-2 were 4H, Example 3 was 5H, Comparative Examples 1-2 were 5H and 6H respectively, and Comparative Example 3 was 6H; in terms of adhesion (crosshatch method), Examples 1-2 were level 2, Example 3 was level 1, and Comparative Examples 1-3 were all improved to level 1 or 0; in terms of salt spray resistance (5% NaCl solution), Examples 1-3 were 380-450h, and Comparative Examples 1-3 were improved to 480-550h; in terms of scratch resistance, Examples 1-3 were 6.5%-8.6%, and Comparative Examples 1-3 were reduced to 3.1%-5.2%. Overall, the performance of the Comparative Examples using modified epoxy resin and modified nano-silica sol, especially Comparative Example 3 which used both, was better than that of the Examples which did not use modified raw materials, indicating that the modified raw materials can effectively improve the light transmittance, hardness, adhesion, salt spray resistance and scratch resistance of the coating solution.

[0083] The above merely illustrates and explains the present application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or replace them with similar ways, as long as they do not deviate from the application or exceed the scope defined by the present claims.

Claims

1. An anti-scratch coating solution for photovoltaic modules, characterized by: The raw materials include 18-25 parts of methyl isobutyl ketone, 8-12 parts of isopropyl alcohol, 3-6 parts of propylene glycol methyl ether acetate, 2-4 parts of dipropylene glycol methyl ether, 15-22 parts of modified epoxy resin, 3-5 parts of silane coupling agent KH-550, 25-35 parts of modified nano silicon dioxide sol, 1-2.5 parts of nano zirconium oxide, 2-4 parts of nano aluminum nitride powder, 0.8-1.5 parts of polyoxyethylene fatty ether phosphate, 0.5-1.2 parts of ultraviolet absorber UV-327, 0.2-0.5 parts of antioxidant 1010, 1.5-3 parts of polydimethylsiloxane, 0.1-0.3 parts of silicone leveling agent, and 0.3-0.6 parts of dibutyltin dilaurate. The modified epoxy resin is prepared by the following steps: A1, take the bisphenol A type epoxy resin and add methyl isobutyl ketone, stir at 200-300 r / min, and heat to 90-95℃, then slowly add adipic acid and p-toluenesulfonic acid, heat to 110-120℃, and keep the temperature for 4-5h; take samples every 1h to detect the acid value, when the acid value is reduced to 10-15mgKOH / g, stop the reaction, then cool to 60-70℃, add isopropyl alcohol for dilution, and obtain the first modified carboxylated epoxy resin; A2, take the first modified carboxylated epoxy resin and heat to 80-85℃, add silane coupling agent KH-550 and deionized water, stir at 400-500 r / min, then add antioxidant 1010 and dibutyltin dilaurate, continue to keep the temperature and stirring speed, keep the temperature for 3-4h; during the reaction, monitor the intensity change of siloxane characteristic peak 1080cm⁻¹ by Fourier infrared spectrum until the peak intensity is stable, end the reaction, add propylene glycol methyl ether acetate for dilution, cool to 50-55℃, and obtain the second modified siloxane crosslinked epoxy resin; A3, take the second modified siloxane crosslinked epoxy resin, add untreated nano zirconium oxide and polydimethylsiloxane, disperse at high speed of 8000-10000 r / min for 30-45min, then transfer into a ball mill, the medium is 5mm maroon ball, the ball to material ratio is 8:1, ball mill for 2-3h to ensure the uniform dispersion of nano zirconium oxide; after ball milling, heat to 70-75℃, add ultraviolet absorber UV-327, stir for 1-1.5h, then cool to room temperature, filter through a 1μm filter membrane, and obtain the modified epoxy resin.

2. The anti-scratch coating solution for photovoltaic modules according to claim 1, characterized in that: The amount ratio of the bisphenol A type epoxy resin, methyl isobutyl ketone, adipic acid, p-toluenesulfonic acid, isopropyl alcohol in step A1 of the modified epoxy resin preparation is 300-350g:150-180mL:25-30g:0.5-1g:30-40mL; The amount ratio of the first modified carboxylated epoxy resin, silane coupling agent KH-550, deionized water, antioxidant 1010, dibutyltin dilaurate, propylene glycol methyl ether acetate in step A2 is 200-250g:10-15g:5-8mL:0.8-1.2g:1-1.5g:20-25mL; The use amount ratio of the second modified siloxane crosslinking epoxy resin, nano zirconium oxide, polydimethylsiloxane and ultraviolet absorber UV-327 in the A3 is 180-220 g:8-12 g:2-3 g:1-2 g.

3. The anti-scratch coating solution for photovoltaic modules according to claim 1, characterized in that: The nano zirconium oxide is surface pretreated nano zirconium oxide, and the pretreatment step is as follows: untreated nano zirconium oxide powder is added into 4 times of anhydrous ethanol by mass, ultrasonic dispersion is performed at a power of 250 W for 30 min, then 2% of silane coupling agent KH-570 by mass of the nano zirconium oxide is added, and reaction is performed at 60°C under stirring at a speed of 400 r / min for 2 h, after the reaction, centrifugal separation is performed, the precipitate is collected and vacuum dried at 90°C for 3 h to obtain the nano zirconium oxide.

4. The anti-scratch coating solution for photovoltaic modules according to claim 1, characterized in that: The nano aluminum nitride powder is coated and modified nano aluminum nitride, and the coating and modification step is as follows: untreated nano aluminum nitride powder is dispersed in 5 times of deionized water by mass to prepare a suspension, 6% of trisodium citrate by mass of the nano aluminum nitride is added as a dispersant, and ultrasonic treatment is performed at a power of 350 W for 40 min; then the temperature is increased to 65°C, 15% of sodium silicate solution by mass with a mass fraction of 10% by mass of the nano aluminum nitride is added dropwise, after the dropwise addition is completed, dilute nitric acid is used to adjust the pH to 6, and the temperature is maintained and stirred for 2.5 h; after the reaction, centrifugal separation is performed, the precipitate is washed with deionized water for 4 times, and drying is performed at 110°C for 5 h to obtain the nano aluminum nitride powder.

5. The anti-scratch coating solution for photovoltaic modules according to claim 1, characterized in that: The modified nano silicon dioxide sol is prepared according to the following specific steps: B1, the nano silicon dioxide sol with a solid content of 30% is diluted with isopropyl alcohol, stirring is performed at 300-400 r / min, the temperature is increased to 50-60°C, then the mixture of silane coupling agent KH-560 and deionized water is slowly added dropwise, the dropwise addition time is controlled in 60-90 min; after the dropwise addition is completed, the temperature is increased to 70-75°C, and the reaction is maintained for 3-4 h, during which the particle size change is detected every 30 min until the particle size is stable at 15-20 nm; after the reaction, the temperature is decreased to room temperature, 10-15% of the solvent is removed by distillation under reduced pressure to obtain the first modified nano silicon dioxide sol; B2, the first modified nano silicon dioxide sol is taken, the modified epoxy resin in claim 1 is added, stirring is performed at 500-600 r / min, the temperature is increased to 80-85°C, then dibutyltin dilaurate is added, and ethanolamine is added dropwise to adjust the pH to 7-8, then the reaction is maintained for 5-6 h, during which the intensity change of the characteristic peak 910 cm⁻¹ of the epoxy group is monitored by Fourier infrared spectrum until the peak intensity is reduced by 80%, after the reaction, propylene glycol methyl ether acetate is added for dilution, the temperature is decreased to 40-45°C to obtain the second modified nano silicon dioxide sol; B3, the second modified nano silicon dioxide sol is taken, untreated nano aluminum nitride powder is added, then polyoxyethylene fatty ether phosphate is added, ultrasonic dispersion treatment is performed at a power of 300 W for 60-90 min, during which the stirring is stopped every 20 min for 10 min to prevent local overheating; after the dispersion is completed, the temperature is decreased to room temperature, ultraviolet absorber UV-327 is added, and continuous stirring is performed at 300-400 r / min for 40-60 min until uniform dispersion is achieved; Cooling to room temperature, using 1 μm filter membrane filtration, to obtain modified nano-silica sol.

6. The anti-scratch coating solution for photovoltaic modules according to claim 5, characterized in that: The amount ratio of the nano-silica sol, isopropanol, silane coupling agent KH-560 and deionized water in B1 is 400-500 g: 200-250 mL: 15-20 g: 10-15 mL. The amount ratio of the first modified nano-silica sol, modified epoxy resin, dibutyltin dilaurate and propylene glycol methyl ether acetate in B2 is 300-350 g: 80-100 g: 2-3 g: 50-60 mL. The amount ratio of the second modified nano-silica sol, nano-aluminum nitride powder, polyoxyethylene fatty ether phosphate and ultraviolet absorber UV-327 in B3 is 250-300 g: 15-20 g: 3-5 g: 2-3 g.

7. The method for preparing the anti-scratch coating solution for photovoltaic modules according to claim 1, characterized in that: Specifically comprising the following steps: S1, adding methyl isobutyl ketone, isopropanol, propylene glycol methyl ether acetate and dipropylene glycol methyl ether into a three-necked flask, stirring at a rate of 200-300 r / min, mixing at room temperature for 15-20 min to form a mixed solvent; S2, slowly adding modified epoxy resin into the mixed solvent, increasing the stirring rate to 400-500 r / min and increasing the temperature to 50-55 °C, and stirring for 30-40 min until the resin is completely dissolved; then adding silane coupling agent KH-550 and continuing to stir for 20-30 min to form a premix; S3, adding modified nano-silica sol, nano-zirconium oxide and nano-aluminum nitride powder into the premix in sequence, adjusting the stirring rate to 600-700 r / min, and stirring at room temperature for 1-1.5 h; then adding polyoxyethylene fatty ether phosphate and continuing to stir for 30-45 min; S4, adding ultraviolet absorber UV-327, antioxidant 1010, polydimethylsiloxane and silicone leveling agent into the system, reducing the stirring rate to 300-400 r / min and increasing the temperature to 60-65 °C, and stirring for 40-50 min to ensure that the additives are uniformly dispersed; S5, adding dibutyltin dilaurate, maintaining the stirring rate at 300-400 r / min, increasing the temperature to 70-75 °C, and reacting for 1-1.5 h; after the reaction is completed, sampling and detecting the viscosity at 25 °C, which is 200-300 mPa・s; after the viscosity is qualified, cooling the system to room temperature, and filtering under reduced pressure using a 1 μm organic filter membrane; after filtration, transferring the coating solution into a sealed container, and standing and aging at 25 °C in the dark for 24-36 h to obtain a photovoltaic module scratch-resistant coating solution.

8. The method for preparing an anti-scratch coating liquid for photovoltaic modules according to claim 7, characterized in that: In S5, if the viscosity is too high, adding an appropriate amount of methyl isobutyl ketone to adjust the viscosity; if the viscosity is too low, removing a small amount of solvent by reduced pressure distillation.

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