Photovoltaic glass self-cleaning nano coating liquid with anti-reflection and repair functions

Abstract

The invention relates to the field of photovoltaic material preparation, and discloses a photovoltaic glass self-cleaning nano coating liquid with anti-reflection and repair functions, which comprises 30-50 parts of silica sol with nano SiO2 particle size of 10-30 nm; the photocatalytic material is selected from a mixture of nano zinc oxide (ZnO with the particle size of 5-20 nm) and titanium dioxide (TiO2, anatase type), and the molar ratio of ZnO to TiO2 is (1: 1)-(3: 1); 10-20 parts of fluorocarbon resin, the solid content of which is 40%-50%; the antistatic agent is selected from antimony-doped tin oxide (ATO) nanoparticles or polyaniline conductive polymers, and the silane coupling agent is selected from KH-560 or KH-570; the solvent is formed by mixing ethyl alcohol and deionized water according to the volume ratio of (1: 1)-(3: 1). The silica sol, the photocatalytic material, the fluorocarbon resin and other components are reasonably proportioned, the particle size of nano SiO2 in the silica sol is 10-30 nm, and the surface size gt of old glass can be effectively filled up; the directional repair of a damaged film layer on the surface of the glass is realized.

Description

Technical Field

[0001] The invention relates to the technical field of photovoltaic material preparation, in particular to a photovoltaic glass self-cleaning nano-coating liquid with anti-reflection and repairing functions. Background Art

[0002] According to statistics from the International Energy Agency (IEA), the global stock of photovoltaic modules exceeds 700GW, of which 65% are modules that have been in service for more than 5 years, and the annual power generation loss of old modules is about 12 billion kWh. As the service life of photovoltaic modules increases (usually more than 10 years), the glass surface is exposed to the outdoor environment for a long time, and the following problems are common: film aging and damage: the original anti-reflection film (AR film) produces microcracks (size 0.1-5μm) due to acid rain erosion and wind and sand wear, resulting in a decrease in light transmittance (annual attenuation rate of about 0.5% to 1%); pollutant accumulation: organic pollutants such as dust and bird droppings are adsorbed on the surface, forming local obstructions, causing hot spot effects (temperature rises by 10-15℃, power loss ≥5%); electrostatic adsorption intensifies: the electrostatic voltage on the glass surface in a dry environment can reach 2-5kV, accelerating the adsorption of fine dust particles (particle size <50μm accounts for more than 60%).

[0003] Existing technologies (such as Huizhong Technology's RDS coating liquid) rely on super-hydrophilic dust prevention, but do not solve the problem of electrostatic adsorption of dust, resulting in transmittance attenuation after long-term use. Harsh construction conditions: For example, Sysmec ZCP0037 requires two-component step-by-step construction (primer + scraper), and the curing time is as long as 24 hours, which is difficult to adapt to outdoor on-site construction needs. Repair and anti-reflection separation: Mainstream products on the market (such as RDS coating liquid) can only achieve a single function and cannot solve the problems of transmittance recovery and surface protection at the same time; Lack of long-term effectiveness: Anti-static and self-cleaning functions fail in 6-12 months in outdoor environments, and users need to rework frequently (average maintenance 2-3 times a year); High construction threshold: More than 70% of repair technologies rely on professional equipment, making it difficult for small and medium-sized power stations to bear the cost of transformation.

[0004] In the existing technology, photovoltaic glass self-cleaning coating technology has made certain progress, but the following problems still exist: Insufficient repair ability: Most coating solutions are only designed for new glass and cannot repair film damage and microcracks on the surface of old glass caused by weathering and wear. The transmittance improvement is limited, high-temperature curing is required, and the hardness is as low as 2H, and the wear resistance is insufficient. At present, there is no nano-coating solution that can be constructed at room temperature, has transmittance repair, self-cleaning, anti-static and long-term weather resistance, especially lacking a directional repair solution for microcracks on the surface of old glass (size>1μm). Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention provides a self-cleaning nano-coating solution for photovoltaic glass with an antireflection and repair function, which solves the problems of insufficient repair ability (most coating solutions are difficult to repair the damage and microcracks of the old glass film layer), limited improvement in light transmittance, the need for high-temperature curing, low hardness, and insufficient wear resistance in the existing self-cleaning coating technology for photovoltaic glass.

[0006] To achieve the above objectives, the present invention is realized through the following technical solutions: A self-cleaning nano-coating solution for photovoltaic glass with an antireflection and repair function, comprising 30-50 parts of silica sol, the nano-SiO2 particle size of which is 10-30 nm; 5-15 parts of a photocatalytic material, selected from a mixture of nano-zinc oxide (ZnO, particle size 5-20 nm) and titanium dioxide (TiO2, anatase type), wherein the molar ratio of ZnO to TiO2 is (1:1)-(3:1); 10-20 parts of fluorocarbon resin, with a solid content of 40% to 50%; 2-5 parts of an antistatic agent, selected from antimony-doped tin oxide (ATO) nanoparticles or polyaniline conductive polymers, 3-8 parts of a silane coupling agent, selected from KH-560 or KH-570; 20-30 parts of a solvent, which is a mixture of ethanol and deionized water in a volume ratio of (1:1)-(3:1).

[0007] Preferably, the weight ratio of ZnO to TiO2 in the photocatalytic material is (2:1)-(5:1), and the surface of the nano-ZnO is coated with a SiO2 shell layer, and the shell layer thickness is 1-3 nm.

[0008] Preferably, the antistatic agent is ATO nanoparticles, with a particle size of 10-50 nm and a surface resistivity ≤ 1×10 12 Ω·cm.

[0009] Preferably, the fluorocarbon resin is a copolymer of polyvinylidene fluoride (PVDF) and acrylate, and the glass transition temperature is 50-80 °C.

[0010] Preferably, the SiO2 shell layer in the photocatalytic material is coated by the sol-gel method, and the pH value of the coating solution is 4-6.

[0011] A preparation method for a self-cleaning nano-coating solution for photovoltaic glass with an antireflection and repair function, characterized by comprising the following steps:

[0012] S1. Mix the silica sol with the solvent, and ultrasonically disperse for 20-40 minutes, with a power of 200-500 W;

[0013] S2. Add the photocatalytic material and ball mill for 1-3 hours, with zirconia beads as the ball milling medium and a rotation speed of 200-500 rpm;

[0014] S3. Sequentially add a silane coupling agent, a fluorocarbon resin, and an antistatic agent, and stir for 0.5 - 2 hours at a stirring speed of 800 - 1200 rpm;

[0015] S4. Filter with a filter screen aperture of ≤50 μm to obtain the finished coating solution.

[0016] Preferably, in step S2, the ball milling time is 2 hours and the rotation speed is 300 rpm.

[0017] An application method of a self - cleaning nano - coating solution for photovoltaic glass with antireflection and repair functions, characterized by comprising the following steps:

[0018] A1. Clean the surface of the photovoltaic glass until the contact angle ≥90°, and after drying, the surface roughness Ra ≤0.2 μm;

[0019] A2. Spray the coating solution with a wet film thickness of 10 - 30 μm;

[0020] A3. Cure at room temperature, with a temperature of 15 - 35°C, a humidity of ≤70%, and a curing time of 6 - 10 hours.

[0021] Preferably, in step S2, the spraying pressure is 0.3 - 0.6 MPa and the spray gun orifice diameter is 0.5 - 1.2 mm.

[0022] The present invention provides a self - cleaning nano - coating solution for photovoltaic glass with antireflection and repair functions. It has the following beneficial effects:

[0023] 1. By reasonably proportioning components such as silica sol, photocatalytic materials, and fluorocarbon resins, the nano - SiO2 particle size in the silica sol is 10 - 30 nm, which can effectively fill the micro - cracks on the surface of old glass with a size >1 μm, realizing the directional repair of the damaged film layer on the glass surface.

[0024] 2. The nano - coating solution of the present invention does not require high - temperature curing and can be cured at room temperature in the range of 15 - 35°C, with convenient construction; its antistatic agent (antimony - doped tin oxide nanoparticles or polyaniline conductive polymers) can reduce the static voltage on the glass surface to a lower level, inhibit static adsorption of dust, and avoid the adhesion of fine - particle dust; and through the optimization of each component, the light transmittance of the coated glass is significantly improved, effectively improving the problem of annual power generation loss of old photovoltaic modules and reducing the power loss caused by the hot - spot effect.

[0025] 3. In the present invention, the fluorocarbon resin is a copolymer of polyvinylidene fluoride and acrylate, with a suitable glass transition temperature. In combination with the silane coupling agent, the bonding force between the coating solution and the glass surface is enhanced, making the hardness of the coating layer reach above 2H and significantly enhancing the wear resistance. The SiO2 shell layer on the surface of the nano-ZnO in the photocatalytic material is coated by the sol-gel method, improving the chemical stability of the material, enabling the antistatic and self-cleaning functions to be maintained for a long time, with a weather resistance of more than 3 years in outdoor environments, greatly reducing the maintenance frequency and cost of users. At the same time, the construction method is simple and does not require professional equipment, reducing the transformation cost of small and medium-sized power stations. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a flowchart of the preparation method of the present invention;

[0027] Figure 2 It is a flowchart of the application method of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

[0029] Example 1:

[0030] Please refer to the attached Figure 1 - attached Figure 2 The present invention provides a self-cleaning nano-coating solution for photovoltaic glass with an antireflection and repair function, including 45 parts of silica sol (SiO2, 20nm), 10 parts of photocatalytic material ZnO (15nm) + 2 parts of TiO2 (anatase type) (ZnO:TiO2 molar ratio = 2.5:1), 18 parts of fluorocarbon resin (PVDF-acrylate copolymer, solid content 45%), 4 parts of ATO nanoparticles (30nm), 6 parts of KH-560, and 28 parts of solvent (ethanol:water = 2:1).

[0031] A preparation method of a self-cleaning nano-coating solution for photovoltaic glass with an antireflection and repair function includes the following steps:

[0032] Step 1: Mix the silica sol and the solvent, and ultrasonically disperse for 30 minutes (400W);

[0033] Step 2: Add ZnO and TiO2, and ball mill for 2 hours (zirconia beads, 300rpm);

[0034] Step 3: Add KH-560, fluorocarbon resin, and ATO in sequence, and stir for 1.5 hours (1000rpm);

[0035] Step 4: Pass through a 400-mesh sieve to obtain the coating solution.

[0036] An application method of a self-cleaning nano-coating solution for photovoltaic glass with an anti-reflection and repair function includes the following steps:

[0037] Step 1: Spray on the aged photovoltaic glass (initial light transmittance 89.3%, surface microcrack density 5 cracks / mm 2 ), wet film thickness 20 μm;

[0038] Step 2: Cure at room temperature for 8 hours (25 °C, humidity 60%);

[0039] Step 3: Use a detection device to detect the cured self-cleaning nano-coating. Detection results:

[0040] Light transmittance: Increased to 94.1% (spectrophotometer, GB / T 2680);

[0041] Surface repair: Microcracks reduced to 0.2 cracks / mm 2 (observed by SEM);

[0042] Hardness: 4H (ASTM D3363);

[0043] Contact angle: 7° (GB / T 30693);

[0044] Abrasion resistance: 1000 times of Taber friction (CS-10 wheel, 1 kg load), light transmittance attenuation ≤ 0.5%.

[0045] Beneficial effects of Example 1:

[0046] Example 2: A self-cleaning nano-coating solution for photovoltaic glass with an anti-reflection and repair function includes 45 parts of silica sol (SiO2, 20 nm), 10 parts of photocatalytic material ZnO (15 nm) + 2 parts of TiO2 (anatase type) (ZnO:TiO2 molar ratio = 2.5:1), 18 parts of fluorocarbon resin (PVDF-acrylate copolymer, solid content 45%), 5 parts of ATO nanoparticles (30 nm), 6 parts of KH-560, and 28 parts of solvent (ethanol:water = 3:1).

[0047] Detection results:

[0048] Surface resistivity: 8.3×10 11 Ω·cm (ASTM D257);

[0049] Dust adsorption rate: Reduced by 62% compared with the comparative example (CN202110987654.3) (simulated sand and dust experiment, ISO 12103-1).

[0050] Beneficial effects of Example 2: On the basis of Example 1, the amount of ATO is increased to 5 parts, and the solvent is changed to ethanol:water = 3:1, so as to achieve the effect of high antistatic performance.

[0051] Example 3: A self-cleaning nano-coating solution for photovoltaic glass with antireflection and repair functions, comprising 45 parts of silica sol (SiO2, 20 nm), 12 parts of photocatalytic material ZnO (15 nm) + 3 parts of TiO2 (anatase type) (molar ratio of ZnO:TiO2 = 2.5:1), and the surface of ZnO is coated with a SiO2 shell layer (thickness 2 nm), 18 parts of fluorocarbon resin (PVDF-acrylate copolymer, solid content 45%), 4 parts of ATO nanoparticles (30 nm), 6 parts of KH-560, and solvent (ethanol:water = 2:1): 28 parts.

[0052] Test results:

[0053] Photodegradation efficiency: After 4 hours of UV irradiation, the degradation rate of methylene blue is 96% (ISO 10678);

[0054] Transmittance stability: After 6 months of outdoor exposure, the transmittance attenuation ≤ 1.2% (the attenuation of Comparative Example CN201910876543.2 is 3.5%).

[0055] Beneficial effects of Example 3: On the basis of Example 1, the amount of ZnO is increased to 12 parts, the amount of TiO2 is increased to 3 parts, and at the same time, the surface of ZnO is coated with a SiO2 shell layer (thickness 2 nm), so as to achieve the effect of enhanced photocatalysis.

[0056] Example 4: A self-cleaning nano-coating solution for photovoltaic glass with antireflection and repair functions, comprising 45 parts of silica sol (SiO2, 20 nm), 10 parts of photocatalytic material ZnO (15 nm) + 2 parts of TiO2 (anatase type) (molar ratio of ZnO:TiO2 = 2.5:1), 18 parts of fluorocarbon resin (PVDF-acrylate copolymer, solid content 45%), 4 parts of ATO nanoparticles (30 nm), 6 parts of KH-560, and solvent (isopropanol:water = 1:1, adding 0.5 part of sodium dodecyl sulfate): 28 parts.

[0057] An application method of a self-cleaning nano-coating solution for photovoltaic glass with antireflection and repair functions, comprising the following steps:

[0058] Step 1: Spray it on aged photovoltaic glass (initial transmittance 89.3%, surface microcrack density 5 cracks / mm 2 ), wet film thickness 20 μm;

[0059] Step 2: Cure for 12 hours (5 °C);

[0060] Step 3: Use a detection device to detect the cured self-cleaning nano-coating. Detection results:

[0061] Curing integrity: The film layer has no cracks;

[0062] Adhesion: Grade 5B.

[0063] Beneficial effects of Example 4: On the basis of Example 1, change the solvent to isopropanol:water = 1:1, and add 0.5 parts of sodium dodecyl sulfate, thereby achieving the effect of low-temperature construction

[0064] Example 5: A self-cleaning nano-coating solution for photovoltaic glass with anti-reflection and repair functions, including 45 parts of silica sol (SiO2, 20nm), 10 parts of photocatalytic material ZnO (15nm) + 2 parts of TiO2 (anatase type) (ZnO:TiO2 molar ratio = 2.5:1), 20 parts of fluorocarbon resin (PVDF-acrylate copolymer, solid content 45%), 2 parts of ultraviolet absorber, 4 parts of ATO nanoparticles (30nm), 6 parts of KH-560, and solvent (ethanol:water = 2:1): 28 parts.

[0065] Detection results:

[0066] QUV aging: After 1500 hours, the light transmittance decays by 0.8% (the decay of the comparative example is 2.3%);

[0067] Salt spray test: No blistering after 240 hours.

[0068] Beneficial effects of Example 5: On the basis of Example 1, increase the fluorocarbon resin to 20 parts and add 2 parts of ultraviolet absorber (Tinuvin 1130), thereby achieving the effect of high weather resistance.

[0069] Example 6: A self-cleaning nano-coating solution for photovoltaic glass with anti-reflection and repair functions, including 45 parts of silica sol (SiO2, 20nm), 10 parts of photocatalytic material ZnO (15nm) + 2 parts of TiO2 (anatase type) (ZnO:TiO2 molar ratio = 2.5:1), 18 parts of fluorocarbon resin (PVDF-acrylate copolymer, solid content 45%), 3 parts of polyaniline conductive polymer, 6 parts of KH-560, and solvent (pure water): 28 parts.

[0070] Detection results:

[0071] Surface resistivity: 2.1×10 12 Ω·cm;

[0072] Cost: 35% lower than the comparative example.

[0073] Beneficial effects of Example 6: On the basis of Example 1, 3 parts of aniline conductive polymer are used to replace ATO, and pure water is used as the solvent to achieve the effect of low cost.

[0074] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A self-cleaning nano-coating solution for photovoltaic glass with an antireflection and repair function, characterized in that, It includes 30 - 50 parts of silica sol, with the nano - SiO₂ particle size being 10 - 30 nm; 5 - 15 parts of photocatalytic material, selected from the mixture of nano - zinc oxide (ZnO, particle size 5 - 20 nm) and titanium dioxide (TiO₂, anatase type), where the molar ratio of ZnO to TiO₂ is (1:1) - (3:1); 10 - 20 parts of fluorocarbon resin, with a solid content of 40% - 50%; 2 - 5 parts of antistatic agent, selected from antimony - doped tin oxide (ATO) nanoparticles or polyaniline conductive polymer, 3 - 8 parts of silane coupling agent, selected from KH - 560 or KH - 570; 20 - 30 parts of solvent, which is a mixture of ethanol and deionized water in a volume ratio of (1:1) - (3:1).

2. The self-cleaning nano-coating solution for photovoltaic glass with an anti-reflection and repair function according to claim 1, characterized in that, In the photocatalytic material, the weight ratio of ZnO to TiO₂ is (2:1) - (5:1), and the surface of nano - ZnO is coated with a SiO₂ shell layer, with the shell layer thickness being 1 - 3 nm.

3. The self-cleaning nano-coating solution for photovoltaic glass with an antireflection and repair function according to claim 1, characterized in that, The antistatic agent is ATO nanoparticles with a particle size of 10 - 50 nm and a surface resistivity ≤ 1×10 12 Ω·cm.

4. The self-cleaning nano-coating liquid for photovoltaic glass with an anti-reflection and repair function according to claim 1, characterized in that, The fluorocarbon resin is a copolymer of polyvinylidene fluoride (PVDF) and acrylate, with a glass transition temperature of 50 - 80 °C.

5. A self-cleaning nano-coating solution for photovoltaic glass with an antireflection and repair function, characterized in that, In the photocatalytic material, the SiO₂ shell layer is coated by the sol - gel method, and the pH value of the coating solution is 4 - 6.

6. The preparation method of a self-cleaning nano-coating solution for photovoltaic glass with an antireflection and repair function according to any one of claims 1-5, characterized in that, It includes the following steps: S1. Mix the silica sol and the solvent, and ultrasonically disperse for 20 - 40 minutes, with a power of 200 - 500 W; S2. Add the photocatalytic material and ball - mill for 1 - 3 hours. The ball - milling medium is zirconia beads, and the rotation speed is 200 - 500 rpm; S3. Sequentially add the silane coupling agent, fluorocarbon resin, and antistatic agent, and stir for 0.5 - 2 hours, with a stirring speed of 800 - 1200 rpm; S4. Filter, with the filter screen pore size ≤50 μm, to obtain the finished coating solution.

7. A method for preparing a self-cleaning nano-coating solution for photovoltaic glass with an antireflection and repair function, characterized in that, In step S2, the ball - milling time is 2 hours and the rotation speed is 300 rpm.

8. The application method of a self-cleaning nano-coating solution for photovoltaic glass with an antireflection and repair function according to any one of claims 1-5, characterized in that, It includes the following steps: A1. Clean the surface of the photovoltaic glass until the contact angle ≥90°, and after drying, the surface roughness Ra ≤0.2 μm; A2. Spray the coating solution, with the wet film thickness being 10 - 30 μm; A3. Cure at room temperature, with the temperature being 15 - 35 °C, the humidity ≤70%, and the curing time being 6 - 10 hours.

9. The application method of a self-cleaning nano-coating solution for photovoltaic glass with an antireflection and repair function according to claim 8, characterized in that, In step S2, the spraying pressure is 0.3 - 0.6 MPa, and the spray gun orifice diameter is 0.5 - 1.2 mm.

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