A transparent corrosion-resistant powder coating on the glass surface of a photovoltaic device and a method for preparing the same

Abstract

The application discloses a kind of photovoltaic device glass surface transparent corrosion-resistant powder coating and preparation method thereof, belong to corrosion-resistant powder coating technical field.The powder coating is composed of acrylic resin, polyvinylidene fluoride resin, light-transmitting reinforcing filler A, light-transmitting reinforcing filler B, reinforcing agent, antioxidant, brightener, leveling agent, benzoin, defoaming agent, first raw material is added into extruder, melt mixes after extrusion, broken and sieved into powder coating;Glass matrix is preheated, and the surface of substrate is electrostatically sprayed with powder coating, and the transparent corrosion-resistant powder coating on the surface of photovoltaic device glass is obtained after baking and cooling.The acrylic resin and fluorocarbon resin are used as the matrix in the powder coating provided by the application, and the light-transmitting reinforcing material synergistically acts, the light-transmitting property and weather resistance are better than those of general acrylic resin, no VOC emission is generated, and it is more environmentally friendly.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of corrosion-resistant powder coating, and particularly relates to a transparent corrosion-resistant powder coating on the surface of a photovoltaic device glass and a preparation method thereof. BACKGROUND

[0002] The photovoltaic industry is one of the new energy fields that have developed rapidly in recent years. The transparent glass on the surface of a photovoltaic device is an important component of the entire photovoltaic module, which functions to maximize the absorption of solar energy and protect the internal core components. However, the photovoltaic glass plate is exposed to harsh natural environments for years, such as high temperature and humidity, salt spray corrosion, high ultraviolet radiation, and wind and sand abrasion, which puts very high requirements on the coating on the surface of the glass.

[0003] The main function of the photovoltaic glass coating is to protect the glass substrate from environmental corrosion while ensuring the high light transmittance and long-term stability of the coating itself. Specifically, the photovoltaic glass coating needs to meet the following key requirements: first, high light transmittance, the coating must maximize the transmittance of sunlight (> 90%) to improve the power generation efficiency of the photovoltaic module. Second, excellent weather resistance, the coating needs to withstand long-term ultraviolet radiation, high temperature and humidity, and salt spray corrosion without performance degradation. In addition, the coating also needs to have good impact resistance to avoid cracking or peeling during transportation, installation, and service. At the same time, environmental friendliness is also an important indicator, and the coating preparation process should minimize VOC emissions to avoid pollution to the environment. Finally, the coating should also have additional functionality, such as self-cleaning performance, which can effectively reduce dust adhesion and thus maintain long-term high-efficiency power generation performance.

[0004] Although existing coating technologies have been applied to photovoltaic glass plates, there are still many deficiencies in practical applications. For example, acrylic coatings have poor weather resistance and easily age in ultraviolet and high humidity environments, leading to rapid decline in light transmittance. Fillers such as silica, titanium oxide, and glass powder in traditional coatings can easily cause light scattering due to poor dispersibility and large particle size (> 10 nm), thereby reducing light transmittance. Therefore, in order to meet the needs of the development of the photovoltaic industry in the future, a high-performance photovoltaic glass coating is urgently needed, which can not only greatly improve the light transmittance but also maintain long-term stability in harsh environments. SUMMARY

[0005] In view of the deficiencies of the prior art and to solve the problem of corrosion failure of the coating on the surface of the photovoltaic device glass plate in harsh corrosive environments, the present application aims to provide a transparent corrosion-resistant powder coating on the surface of a photovoltaic device glass and a preparation method thereof.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows:

[0007] The first aspect of the present application is to provide a kind of photovoltaic device glass surface transparent corrosion-resistant powder coating, by weight parts, including the following raw materials: thermoplastic solid acrylic resin 16-30 parts, polyvinylidene fluoride resin 33-45 parts, light transmission enhancing filler A 10-30 parts, light transmission enhancing filler B 5-25 parts, reinforcing agent 0.5-5 parts, antioxidant 0.3-0.8 parts, brightener 0.1-1 parts, leveling agent 0.1-2 parts, benzoin 0.1-0.5 parts, defoaming agent 0.1-0.8 parts.

[0008] In some embodiments, the thermoplastic solid acrylic resin is copolymerized from methyl methacrylate, ethyl acrylate, acrylic acid, lauryl methacrylate; wherein the mass ratio of methyl methacrylate to ethyl acrylate is 32-42:8-18, and the glass transition temperature is 60-90℃.

[0009] It should be noted that the content of acrylic acid is 0.2-0.7% of the total mass of the raw materials; the content of lauryl methacrylate is 0.4-2% of the total mass of the raw materials. Methyl methacrylate is used to increase the glass transition temperature, hardness and weather resistance; ethyl acrylate is used to increase the flexibility; acrylic acid is used to increase the adhesion; lauryl methacrylate is used to increase the water resistance and alcohol resistance.

[0010] Preferably, the molecular weight of the thermoplastic solid acrylic resin is 80000-90000; the molecular weight of the polyvinylidene fluoride resin is 300000-450000, and the melting point is 150-175℃.

[0011] It should be noted that the thermoplastic solid acrylic resin has good physical and mechanical properties, but the melt viscosity is high, and the processability and pigment dispersibility, leveling are affected. The smaller the relative molecular mass of PVDF, the better the leveling, and the better the gloss, but the product adhesion and acid resistance are poor; when the relative molecular mass is large, the product leveling is poor, the product gloss is poor, and the acid and alkali resistance is poor, therefore the molecular weight is limited in this technical solution, and the relative molecular mass should be moderate.

[0012] PVDF resin is a polymer formed by alternating connection of -CH2- and -CF2- groups to form a tight and stable chemical structure, which contains a large number of C-F bonds with a bond energy of 485 KJ / mol, which is much higher than C-H, C-O, Si-O, Si-C, etc., and the C-C bond main chain is surrounded by a series of negative F atoms to form a high-density three-dimensional shield to protect the stability of C-C bond, so it is difficult to be destroyed by light, heat and chemical factors. The effects of acrylic resin and polyvinylidene fluoride resin on impact resistance, weather resistance and adhesion are different, the adhesion of acrylic resin is good, the impact resistance and weather resistance are poor, and the addition of fluorocarbon resin is to improve the weather resistance.

[0013] In some embodiments, the light-transmitting enhancing filler A is a zinc oxide core-shell structure particle coated with nanosilver, which is prepared by the following steps:

[0014] S1: Add zinc acetate dihydrate to methanol and stir to obtain solution 1;

[0015] S2: Add potassium hydroxide to methanol and stir to obtain solution 2;

[0016] S3: adding solution 2 dropwise to solution 1, cooling after the reaction is complete to obtain a solid product, which is then washed and annealed to obtain nano zinc oxide;

[0017] S4: The nano zinc oxide prepared in S3, sucrose, polyvinyl pyrrolidone, and deionized water are stirred and mixed to obtain solution three;

[0018] S5: adding sodium chloride solution to solution three, and then adding silver nitrate solution dropwise to obtain solution four;

[0019] S6: After the four reactions of the solution are completed, centrifugation is performed to obtain a solid product, which is then washed and dried to obtain nano-silver coated zinc oxide core-shell structure particles.

[0020] When Ag is combined with ZnO, the surface plasmon resonance effect of Ag can interact with the optical properties of ZnO to increase light capture efficiency, thereby enhancing light transmission performance. In addition, Ag nanoparticles can act as electron traps, reducing the recombination of electron-hole pairs in ZnO, increasing the lifetime of photogenerated charge carriers in the material, enhancing the optoelectronic properties, and further improving light transmittance.

[0021] Secondly, ZnO has wide-bandgap semiconductor properties and mainly responds to ultraviolet light, while the addition of the Ag shell can broaden the spectral response range of the entire composite material to the visible light region, thereby improving its light transmittance in a wider spectral range.

[0022] Finally, the core-shell structure can reduce light reflection losses on the material surface. The Ag shell can optimize the light incidence and transmission paths, allowing more light energy to enter the ZnO core and improve overall light transmittance.

[0023] Preferably, the particle size of the nano zinc oxide is 3-5 nm, and the thickness of the silver shell layer in the nano silver-encapsulated zinc oxide core-shell structure particles is 2-3 nm.

[0024] Preferably, in S3, solution one is maintained at 60-70°C and solution two is added dropwise, the reaction temperature is 60-70°C, the reaction time is 2-4h, the annealing temperature is 200-300°C, and the annealing time is 1-2h; in S6, solution four is placed in a hydrothermal reactor, and the hydrothermal reactor is placed in a heating device at 150-170°C for 12-13h.

[0025] It should be noted that excessively large nano-zinc oxide particle size can cause light scattering, thereby reducing transmittance. Poor dispersion can also lead to diffuse reflection of light, reducing transmittance. The optimal particle size for nano-zinc oxide is 3nm-5nm. Reaction time is a key factor influencing the preparation of nano-zinc oxide. A sufficiently long reaction time ensures complete reaction and sufficient growth of zinc oxide crystals. However, excessive reaction time can lead to excessive grain growth and agglomeration. Therefore, the S3 reaction time should be controlled within 2-4h to obtain ideal nano-zinc oxide particles.

[0026] In some embodiments, the light-transmitting enhancing filler B is thiol-modified ZnSe / ZnS composite quantum dots, and the particle size of the ZnSe / ZnS composite quantum dots is 2-8 nm.

[0027] It should be noted that compared with other composite quantum dots such as CdSe / ZnS, ZnSe / ZnS composite quantum dots have the following advantages:

[0028] ZnSe / ZnS composite quantum dots have a wide bandgap, a high refractive index, and a low absorption coefficient. They exhibit high UV absorption and visible light transmittance, enhancing the overall light transmittance of the coating while blocking harmful UV light. Furthermore, ZnSe exhibits excellent chemical stability. When combined with the core-shell structure of ZnS, it exhibits enhanced stability under long-term light and environmental exposure, making it suitable for more demanding outdoor photovoltaic applications. Furthermore, the thiol-modified organic layer provides a protective barrier on the quantum dot surface, preventing oxidation and moisture intrusion, thereby enhancing the optical stability and long-term lifespan of the composite quantum dots. The thiol molecules also effectively passivate surface defect states on the ZnS / ZnSe quantum dots, reducing light absorption losses and light scattering caused by surface and internal defects. This allows more light to pass through the material without being absorbed or scattered, thereby improving light transmittance. ZnSe / ZnS does not contain harmful heavy metals, complying with environmental regulations, and is an ideal material for green photovoltaic technology.

[0029] Thiol-modified ZnSe / ZnS composite quantum dots were prepared by the following steps:

[0030] 1. Preparation of ZnSe / ZnS composite quantum dots by hot injection method:

[0031] 15 mmol of zinc stearate was added to a three-necked flask, along with 500 ml of 1-octadecene. The mixture was then slowly heated to 240°C and the water vapor in the flask was removed using a vacuum pump. At 240°C, 15 mmol of a Se precursor (selenium powder-1-octadecene solution) was injected, and the mixture was slowly heated to 270°C and held for 20 minutes to obtain ZnSe cores.

[0032] Lower the temperature to 260°C, slowly inject 5 ml of sulfur precursor (i.e., 5 mol / L sulfur in octadecene solution) and 5 ml of Zn precursor (i.e., 0.25 mol / L zinc stearate in octadecene solution), lower the temperature to 250°C and maintain for 30 min, then cool to room temperature, centrifuge and wash with methanol and acetone 3 to 4 times to obtain ZnSe / ZnS composite quantum dots, which are stored in the dark.

[0033] 2. ZnSe / ZnS composite quantum dot modification:

[0034] The composite quantum dots were dispersed in a mixed solvent of toluene and cyclohexane at a mass ratio of 1:1000 in a dark environment, purged with argon, stirred, and refluxed for 2 to 3 hours, and then KH590 was added dropwise (the mass ratio of KH590 to ZnSe / ZnS composite quantum dots was 1:0.3 to 0.5). The mixture was stirred and refluxed for 24 hours to allow the silane groups to bind to the surface of the quantum dots and form stable Si-O bonds. After centrifugation, the mixture was washed with ethyl acetate and petroleum ether to obtain a modified product Y.

[0035] 1-hexadecyl mercaptan was dissolved in toluene at 65°C, and the above-mentioned modifier Y was added (the mass ratio of modifier Y to 1-hexadecyl mercaptan was 10-15:1). Argon was passed through and the reaction was refluxed at 65°C for 24 hours to allow the long-chain alkyl mercaptan to bind to the thiol groups on the surface of the quantum dots to enhance the hydrophobicity. After centrifugation, the mixture was washed with ethyl acetate and petroleum ether to obtain thiol-modified ZnSe / ZnS composite quantum dots.

[0036] In some embodiments, the reinforcing agent is single-layer graphene; the antioxidant is at least one of hindered phenols and phosphites; the brightener is a copolymer of butyl acrylate and methyl methacrylate; the leveling agent is an acrylate leveling agent; and the defoaming agent is a wax defoaming agent.

[0037] Single-layer graphene has extremely low absorption of visible light, only approximately 2.3%. This high transmittance enables graphene to provide effective UV shielding without significantly affecting the coating's transparency. Graphene can improve the coating's mechanical properties, and its two-dimensional sheet structure also slows the penetration of water and oxygen, providing excellent UV shielding. This provides UV protection without significantly affecting visible light transmittance, thereby extending the coating's service life, especially in outdoor environments. Few-layer boron nitride nanosheets (h-BN) can also be used as a reinforcing agent.

[0038] Preferably, the brightener is 701 auxiliary agent, the leveling agent is GLP588 or TC486 leveling agent, and the defoaming agent is BYK961 defoaming agent.

[0039] A second aspect of the present invention is to provide a method for preparing a transparent corrosion-resistant powder coating on the surface of photovoltaic device glass, comprising the following steps:

[0040] S1: Add the raw materials into the extruder, melt and mix them, extrude them, and crush and screen them into powder coating;

[0041] S2: After the glass substrate is preheated, powder coating is electrostatically sprayed on the substrate surface. After baking and cooling, a transparent corrosion-resistant powder coating on the surface of the photovoltaic device glass is obtained.

[0042] In some embodiments, in S1, the melting temperature is 170-190°C, and the powder coating particle size is 30-40 μm; in S2, the preheating temperature is 50-90°C, the preheating time is 10-30 min, the electrostatic voltage is 60-80 kV, the baking temperature is 230-260°C, and the baking time is 10-25 min.

[0043] Compared with the prior art, the present invention has the following beneficial effects:

[0044] 1. The coating provided by the present invention is a powder coating, which does not produce VOC emissions and is more environmentally friendly compared to water-based or oil-based acrylic coatings.

[0045] 2. The transparent corrosion-resistant powder coating on the glass surface of photovoltaic devices provided by the present invention uses acrylic resin and fluorocarbon resin as the matrix. Through the synergistic effect with light-transmitting enhancing fillers, it has better light transmittance and weather resistance than general acrylic resin.

[0046] 3. This invention incorporates light-transmitting filler A—silver nanoparticles encapsulated in zinc oxide core-shell structures (ZnO@Ag)—and filler B—thiol-modified nano-zinc sulfide / zinc selenide (ZnS / ZnSe) composite quantum dots. Filler A exhibits excellent light transmission across a broad spectrum, and its core-shell structure reduces light reflection losses on the material's surface. Filler B exhibits high UV absorption and visible light transmittance, along with an ultra-small particle size (<10nm). The thiol-modified organic layer forms a protective barrier on the quantum dot surface, preventing oxidation and moisture intrusion. The synergistic effect of these two fillers significantly improves the coating's light transmittance, UV resistance, optical stability, and service life. DETAILED DESCRIPTION

[0047] The present invention will be further described in detail below. The embodiments described are illustrative and intended to explain the present invention, but should not be construed as limiting the present invention.

[0048] Example 1

[0049] A transparent corrosion-resistant powder coating for the surface of photovoltaic device glass, comprising the following raw materials, by weight: 23 parts of acrylic resin, 35 parts of polyvinylidene fluoride resin, 30 parts of light-transmitting enhancing filler A, 8 parts of light-transmitting enhancing filler B, 1 part of reinforcing agent, 0.5 part of antioxidant, 1 part of brightener, 1 part of leveling agent, 0.4 part of benzoin, and 0.1 part of defoaming agent;

[0050] Among them, the acrylic resin is copolymerized by methyl methacrylate, ethyl acrylate, acrylic acid and lauryl methacrylate, with the ratio of methyl methacrylate to ethyl acrylate being 32:8; the acrylic acid content is 0.5% of the total mass of the raw materials; and the lauryl methacrylate content is 1.2% of the total mass of the raw materials.

[0051] The light-transmitting enhancing filler A is a core-shell structured particle of zinc oxide coated with nano-silver, which is prepared by the following steps:

[0052] Preparation of the zinc oxide core: Zinc oxide nanoparticles were prepared using a hydrothermal method. 0.01 mol of zinc acetate dihydrate was added to 125 mL of methanol and stirred vigorously at 60°C for 1 hour to fully dissolve the zinc acetate dihydrate, yielding Solution 1. 0.03 mol of potassium hydroxide was added to 65 mL of methanol and stirred to dissolve, yielding Solution 2. While Solution 1 was stirring at 60°C, Solution 2 was added dropwise to Solution 1. After the addition was complete, the reaction was continued at 60°C for 2 hours. After the reaction was complete, the reaction mixture was cooled and washed three times with methanol to remove impurities. After rinsing, the mixture was dried and set aside to yield nano-zinc oxide.

[0053] Preparation of silver nanoparticles: 0.2g of nano-zinc oxide, 0.5g of sucrose, 4g of polyvinyl pyrrolidone, and deionized water were weighed and placed in a beaker and stirred to obtain a clear solution. 50mL of 0.04mol / L NaCl solution was added to the clear solution and stirred for 0.5h. 20mL of 0.03mol / L silver nitrate solution was then added dropwise to the mixed solution using a peristaltic pump (at a rate of 1mL / min). The resulting milky white suspension was transferred to a hydrothermal reactor and reacted in an oven at 160°C for 12h. After centrifugation, the product was washed several times with deionized water and anhydrous ethanol, dried in a vacuum at 80°C for 8h, and annealed at 200°C for 2h to obtain the final product—transparent reinforcing filler A (ZnO@Ag)—with a particle size of 5-8nm.

[0054] The light-transmitting enhancing filler B is a thiol-modified ZnSe / ZnS composite quantum dot, which is prepared by the following method:

[0055] 1. Preparation of ZnSe / ZnS composite quantum dots by hot injection method:

[0056] 15 mmol of zinc stearate was added to a three-necked flask, along with 500 ml of 1-octadecene. The mixture was then slowly heated to 240°C and the water vapor in the flask was removed using a vacuum pump. At 240°C, 15 mmol of a Se precursor (selenium powder-1-octadecene solution) was injected, and the mixture was slowly heated to 270°C and held for 20 minutes to obtain ZnSe cores.

[0057] The temperature was lowered to 260°C, and 5 ml of sulfur precursor (i.e., 5 mol / L sulfur in octadecene solution) and 5 ml of Zn precursor (i.e., 0.25 mol / L zinc stearate in octadecene solution) were slowly injected. The temperature was lowered to 250°C and maintained for 30 min. The mixture was then cooled to room temperature. After centrifugation, the mixture was washed four times with methanol and acetone to obtain ZnSe / ZnS composite quantum dots, which were then stored in the dark.

[0058] 2. ZnSe / ZnS composite quantum dot modification:

[0059] The composite quantum dots were dispersed in a mixed solvent of toluene and cyclohexane at a mass ratio of 1:1000 in a dark environment, purged with argon, stirred, and refluxed for 3 hours. KH590 (KH590 to ZnSe / ZnS composite quantum dots mass ratio of 1:0.4) was then added dropwise, stirred, and refluxed for 24 hours to allow the silane groups to bind to the quantum dot surface and form stable Si-O bonds. After centrifugation, the mixture was washed with ethyl acetate and petroleum ether to obtain modified product Y.

[0060] 1-Hexadecyl mercaptan was dissolved in toluene at 65°C, and the above-mentioned modified substance Y (the mass ratio of ZnSe / ZnS composite quantum dots to 1-hexadecyl mercaptan was 13:1) was added. Argon was passed through and the reaction was refluxed at 65°C for 24 hours to allow the long-chain alkyl mercaptan to bind to the thiol groups on the surface of the quantum dots to enhance the hydrophobicity. After centrifugation, the mixture was washed with ethyl acetate and petroleum ether to obtain thiol-modified ZnSe / ZnS composite quantum dots.

[0061] The transparent corrosion-resistant powder coating on the surface of the photovoltaic device glass is obtained by the following preparation method, comprising the following steps:

[0062] S1: acrylic resin, polyvinylidene fluoride resin, light-transmitting enhancing filler A, light-transmitting enhancing filler B, single-layer graphene, antioxidant (BASF Irganox B225), brightener (Ningbo Weikai Chemical WK701), leveling agent (Troy TC486), benzoin, and defoamer (BYK BYK961) were added into a twin-screw extruder according to their weight parts, melt-mixed at 180°C, and then extruded. The mixture was crushed and sieved to obtain a powder coating with a particle size of 35 μm.

[0063] S2: After the glass substrate is preheated in an oven at 70°C for 30 minutes, powder coating is electrostatically sprayed on the surface of the substrate at a voltage of 65kV. The sprayed sample is placed in an oven at 250°C for 20 minutes, taken out and naturally cooled to room temperature to obtain a transparent corrosion-resistant powder coating on the glass surface of the photovoltaic device.

[0064] Example 2

[0065] The raw materials and preparation method are the same as those in Example 1, with the only difference being that: the light-transmitting enhancing filler A is 20 parts, the light-transmitting enhancing filler B is 16 parts, the reinforcing agent is 3 parts; and the ratio of methyl methacrylate to ethyl acrylate is 42:18.

[0066] Example 3

[0067] The raw materials and preparation method are the same as those in Example 1, with the only difference being that: the light-transmitting enhancing filler A is 10 parts, the light-transmitting enhancing filler B is 24 parts, the reinforcing agent is 5 parts; and the ratio of methyl methacrylate to ethyl acrylate is 37:13.

[0068] Example 4

[0069] The raw materials and preparation method are the same as those in Example 1, with the following differences: 18 parts of acrylic resin, 42 parts of polyvinylidene fluoride resin, 10 parts of light-transmitting enhancing filler A, 24 parts of light-transmitting enhancing filler B, and 3 parts of enhancer.

[0070] Comparative Example 1

[0071] The raw materials and preparation method are the same as those in Example 4, with the only difference being: 42 parts of acrylic resin and 18 parts of polyvinylidene fluoride resin.

[0072] Comparative Example 2

[0073] The raw materials and preparation method are the same as those in Example 3, with the only difference being that no light-transmitting enhancing filler A, light-transmitting enhancing filler B, or reinforcing agent is added.

[0074] Comparative Example 3

[0075] The raw materials and preparation method are the same as those in Example 3, with the only difference being that the light-transmitting enhancing filler B is not added.

[0076] Comparative Example 4

[0077] The raw materials and preparation method are the same as those in Example 3, except that the light-transmitting enhancing filler A is not added.

[0078] Performance Testing

[0079] To demonstrate the excellent light transmittance and weather resistance of the transparent, corrosion-resistant powder coating on photovoltaic device glass provided by the present invention, performance tests were conducted on Examples 1-4 and Comparative Examples 1-4. The coatings were tested for aging resistance using Cycle 1 of Method A in GB / T 16422.3-2022, impact resistance using SY / T 0315-2013, light transmittance using GB / T 2410-2008, and wet adhesion using GB / T 5237.4-2017. The performance test data are shown in Table 1.

[0080] Table 1 Performance comparison of Examples 1-4 and Comparative Examples 1-4

[0081]

[0082] As can be seen from Table 1, the initial light transmittance of the examples is higher than that of the comparative examples, indicating that the synergistic effect of the light-transmitting enhancing fillers A and B and the enhancer can significantly improve the light transmittance of the coating. In addition, the light transmittance of the coatings of comparative examples 3 and 4 is higher than that of comparative example 2 to varying degrees, indicating that both the light-transmitting enhancing fillers A and B play a role in improving the light transmittance of the coating.

[0083] The initial light transmittance of Example 4 is lower than that of Examples 1-3, but the degree of decrease in its light transmittance after 2500 hours of UV aging is significantly smaller, indicating that the increase in the fluorocarbon resin content will have a negative impact on the initial light transmittance of the coating, but it helps to improve the weather resistance of the coating, so that the coating can maintain a high light transmittance when serving outdoors for a long time, reducing the impact on power generation efficiency.

[0084] It can be seen from Example 4 and Comparative Example 1 that excessive acrylic resin and insufficient polyvinylidene fluoride resin cannot meet the performance requirements of the coating. The mixing ratio of the two has different effects on impact resistance, weather resistance and adhesion, and a suitable ratio is very important.

[0085] The method for preparing a transparent corrosion-resistant powder coating on the glass surface of a photovoltaic device provided by the present invention introduces a light-transmitting enhancing filler and a polyvinylidene fluoride resin into a traditional acrylic coating, which not only ensures the light transmittance of the coating but also significantly improves the weather resistance of the coating, and has great application potential.

[0086] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. A transparent corrosion-resistant powder coating on the surface of photovoltaic device glass, characterized in that: The invention comprises the following raw materials in parts by weight: 16-30 parts of thermoplastic solid acrylic resin, 33-45 parts of polyvinylidene fluoride resin, 10-30 parts of light-transmitting enhancing filler A, 5-25 parts of light-transmitting enhancing filler B, 0.5-5 parts of reinforcing agent, 0.3-0.8 parts of antioxidant, 0.1-1 parts of brightener, 0.1-2 parts of leveling agent, 0.1-0.5 parts of benzoin, and 0.1-0.8 parts of defoaming agent; wherein the light-transmitting enhancing filler A is nanosilver-encapsulated zinc oxide core-shell structure particles, and the light-transmitting enhancing filler B is thiol-modified ZnSe / ZnS composite quantum dots.

2. The transparent corrosion-resistant powder coating for photovoltaic device glass surface according to claim 1, characterized in that: The thermoplastic solid acrylic resin is copolymerized by methyl methacrylate, ethyl acrylate, acrylic acid and lauryl methacrylate; wherein the mass ratio of methyl methacrylate to ethyl acrylate is 32-42:8-18, and the glass transition temperature is 60-90°C.

3. The transparent corrosion-resistant powder coating on the surface of photovoltaic device glass according to claim 2, characterized in that: The molecular weight of the thermoplastic solid acrylic resin is 80,000-90,000; the molecular weight of the polyvinylidene fluoride resin is 300,000-450,000, and the melting point is 150-175°C.

4. The transparent corrosion-resistant powder coating on the surface of photovoltaic device glass according to claim 1, characterized in that: The nano-silver coated zinc oxide core-shell structure particles are obtained by the following preparation steps: S1: Add zinc acetate dihydrate to methanol and stir to obtain solution 1; S2: Add potassium hydroxide to methanol and stir to obtain solution 2; S3: adding solution 2 dropwise to solution 1, cooling after the reaction is complete to obtain a solid product, which is then washed and annealed to obtain nano zinc oxide; S4: The nano zinc oxide prepared in S3, sucrose, polyvinyl pyrrolidone, and deionized water are stirred and mixed to obtain solution three; S5: adding sodium chloride solution to solution three, and then adding silver nitrate solution dropwise to obtain solution four; S6: After the four reactions of the solution are completed, centrifugation is performed to obtain a solid product, which is then washed and dried to obtain nano-silver coated zinc oxide core-shell structure particles.

5. The transparent corrosion-resistant powder coating on the surface of photovoltaic device glass according to claim 4, characterized in that: The particle size of the nano zinc oxide is 3-5 nm, and the thickness of the silver shell layer in the nano silver-encapsulated zinc oxide core-shell structure particles is 2-3 nm.

6. The transparent corrosion-resistant powder coating on the surface of photovoltaic device glass according to claim 4, characterized in that: In the S3, solution 1 is maintained at 60-70°C and solution 2 is added dropwise, the reaction temperature is 60-70°C, the reaction time is 2-4 hours, the annealing temperature is 200-300°C, and the annealing time is 1-2 hours. In the S6, solution 4 is placed in a hydrothermal reactor, and the hydrothermal reactor is placed in a heating device and reacted at 150-170°C for 12-13 hours.

7. The transparent corrosion-resistant powder coating on the surface of photovoltaic device glass according to claim 1, characterized in that: The particle size of the ZnSe / ZnS composite quantum dots is 2-8 nm.

8. The transparent corrosion-resistant powder coating on the surface of photovoltaic device glass according to claim 1, characterized in that: The reinforcing agent is single-layer graphene; the antioxidant is at least one of hindered phenols and phosphites; the brightener is a copolymer of butyl acrylate and methyl methacrylate; the leveling agent is an acrylate leveling agent; and the defoaming agent is a wax defoaming agent.

9. A method for preparing a transparent corrosion-resistant powder coating on a photovoltaic device glass surface according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: Add the raw materials into the extruder, melt and mix them, extrude them, and crush and screen them into powder coating; S2: After the glass substrate is preheated, powder coating is electrostatically sprayed on the substrate surface. After baking and cooling, a transparent corrosion-resistant powder coating on the surface of the photovoltaic device glass is obtained.

10. The preparation method according to claim 9, characterized in that In S1, the melting temperature is 170-190°C, and the particle size of the powder coating is 30-40 μm; in S2, the preheating temperature is 50-90°C, the preheating time is 10-30 min, the electrostatic voltage is 60-80 kV, the baking temperature is 230-260°C, and the baking time is 10-25 min.

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