Transparent frosted film

Abstract

According to the transparent frosted film, a pre-coated transparent PET base material is adopted, PET is polyethylene glycol terephthalate, the transparent frosted film is prepared through a one-side coating process, the coating process is matched with a coating formula containing a main body film forming matter, an ultraviolet absorbent and other auxiliaries, and the coating side is a transparent coating so as to guarantee the transparency of a back plate; according to the one-side coating process, compared with a traditional process, one layer of coating is reduced, the membrane material comprises a frosted structure for reducing glare interference under strong light, and the photovoltaic module efficiently absorbs solar energy through the membrane material; the transparent frosted film is required to meet preset performance indexes including mechanical properties, optical properties, weather resistance and insulating properties. Belongs to the technical field of photovoltaic modules, and can stably adapt to the use requirements of various small photovoltaic modules for a long time, and meanwhile, through application of a one-side coating process, the preparation cost is effectively reduced.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic module technology. Background Technology

[0002] In existing technologies, the transparent films used in small photovoltaic modules are mostly prepared using a double-sided coating process. This process is cumbersome, resulting in high production costs and hindering large-scale deployment. Furthermore, some transparent films lack a frosted structure, making them prone to glare in strong sunlight, interfering with the absorption of solar energy by the photovoltaic modules and affecting power generation efficiency. In addition, the coating formulations of existing transparent films are often unreasonable, the manufacturing processes are not standardized, and there are no clearly defined and unified performance requirements. This leads to unstable weather resistance, adhesion, and other properties of the film materials, making them unsuitable for long-term outdoor use in small photovoltaic modules. Moreover, some film materials have a narrow range of applications, failing to meet the needs of different types of small photovoltaic modules.

[0003] (1) A patent (CN210156397U) by Zhejiang Jinko Solar Co., Ltd. discloses a portable photovoltaic power supply, whose photovoltaic panel includes a transparent film layer, a first EVA adhesive layer, a battery cell layer and other structures arranged in sequence, wherein the transparent film layer is a frosted PET film layer.

[0004] This frosted film can reduce light reflection to a certain extent and is applicable to portable photovoltaic products, meeting the needs of miniaturization and portability, which is similar to the application scenario of this invention in small photovoltaic modules. However, it may not be deeply optimized for the specific optical performance required to improve the power generation efficiency of photovoltaic modules, such as the balance between high transmittance and high haze.

[0005] (2) The patent (CN222647876U) of Chenguang (Changzhou) New Material Technology Co., Ltd. designs a photovoltaic efficiency enhancement film with double-sided matte coating, which includes an adhesive layer, a second matte coating, a substrate layer and a first matte coating from bottom to top.

[0006] This patent addresses the issues of poor weather resistance and yellowing in current photovoltaic enhancement films by optimizing the film structure, and it can be applied to double-glass modules to increase output power. While its approach to improving film structure and function is similar to this invention, it may lack more in-depth research and innovation regarding the light scattering effect of frosted films to improve photovoltaic module power generation efficiency.

[0007] (3) The patent (CN119751950A) of Zhangjiagang Free Trade Zone Kangdefeier Industrial Co., Ltd. discloses a frosted texture film and its preparation method, which consists of a substrate layer and a frosted texture coating layer, and is formed by photocuring after heating with a specific frosted coating liquid.

[0008] The patent focuses on the preparation method and adapting to different application scenarios by adjusting the components. However, it does not study the improvement of photovoltaic module power generation performance in terms of photovoltaic module application, which is different from the application goal of this invention in photovoltaic modules.

[0009] In summary, existing technologies have not deeply optimized the specific optical properties required to improve the power generation efficiency of photovoltaic modules, such as the balance between high transmittance and high haze; there is a lack of in-depth research and innovation in the light scattering effect of frosted films to improve the power generation efficiency of photovoltaic modules; and in terms of photovoltaic module applications, there has been no research on improving the power generation performance of photovoltaic modules.

[0010] Therefore, there is an urgent need to develop a transparent frosted film to solve the problems in the existing technology. Summary of the Invention

[0011] The purpose of this invention is to provide a transparent frosted film that can stably adapt to the usage requirements of various small photovoltaic modules over a long period of time. At the same time, the application of a one-sided coating process effectively reduces the manufacturing cost, and the film has a simple structure and is easy to use, thereby solving the problems mentioned in the background art.

[0012] To achieve the above objectives, the present invention provides the following technical solution: A transparent frosted film is prepared by a one-sided coating process using a pre-coated transparent PET substrate. The coating process is matched with a coating formulation containing a main film-forming material, a UV absorber and other additives. The coating surface is a transparent coating to ensure the transparency of the back panel. The aforementioned one-sided coating process reduces one coating layer compared to the traditional process, thus achieving cost control. Furthermore, the membrane material includes a frosted structure to reduce glare interference under strong light, and the photovoltaic module achieves efficient solar energy absorption through the membrane material. The transparent frosted film is required to meet preset performance indicators, including mechanical properties, optical properties, weather resistance and insulation properties.

[0013] By adopting the above technical solution, a transparent frosted film with a reasonable structure and suitable for small photovoltaic modules is provided. Through specific substrates, single-sided coating process and matching coating formula, the cost is controllable while ensuring the transparency of the back sheet, reducing strong light glare interference to help photovoltaic modules absorb energy efficiently, and ensuring that the film material meets the multi-dimensional performance requirements of mechanical, optical, weather resistance and insulation, and is suitable for corresponding photovoltaic application scenarios.

[0014] As a further aspect of the present invention: the main film-forming material includes a hydroxyl-containing fluorocarbon resin, which provides weather resistance and adhesion, and facilitates subsequent cross-linking and curing.

[0015] By adopting the above technical solution, the specific type of the main film-forming material in the coating formula is clearly defined. Through the characteristics of hydroxyl-containing fluorocarbon resin, good weather resistance and coating adhesion are provided for the transparent frosted film. At the same time, the necessary conditions are provided for the subsequent cross-linking and curing of the coating, ensuring the stability and service life of the film coating.

[0016] As a further aspect of the present invention, the mixing steps of the coating formulation include: first adding the main film-forming material, then adding the ultraviolet absorber diluted with solvent, and finally adding other additives.

[0017] By adopting the above technical solution, the mixing process of each component of the coating formulation is standardized. Through a reasonable order of addition, it is ensured that the main film-forming material, UV absorber and other additives can be fully integrated, avoiding the degradation of formulation performance due to uneven mixing of components, and ensuring the stability and compatibility of the coating formulation.

[0018] As a further aspect of the present invention, the requirements for the preparation environment of the coating formulation include: meeting the preset temperature, preset humidity, and preset cleanliness requirements, and ensuring that the preparation area is well-ventilated and away from fire sources and static electricity.

[0019] By adopting the above technical solutions, the overall standard for the preparation environment of the coating formulation is clearly defined. By controlling the temperature, humidity, cleanliness and surrounding environmental requirements, adverse environmental factors are avoided from affecting the stability and mixing effect of the formulation components, ensuring that the prepared coating formulation meets the coating process requirements and guaranteeing the quality of the membrane material.

[0020] As a further aspect of the present invention: the coating process employs one of micro-recessed coating, comma blade coating, and slot coating, using the corresponding coating equipment to precisely transfer the frosted coating liquid to one side of the pre-coated transparent PET substrate to achieve uniform coating.

[0021] By adopting the above technical solution, the specific optional types and operation logic of the coating process are clearly defined. Through the appropriate coating equipment, the frosted coating liquid is accurately and evenly transferred to one side of the pre-coated transparent PET substrate, ensuring the consistency of the coating effect and avoiding the impact of uneven coating on the optical and mechanical properties of the film material.

[0022] As a further aspect of the present invention, the preparation steps include the following sub-steps: S1: Prepare the abrasive base material by mixing the solvent with the resin particles, purging the reaction vessel with nitrogen to control the oxygen content in the vessel to be lower than the preset ratio, and then premixing, high-speed dispersion, degassing, filtering and concentration. S2: The frosted base material is coated onto a pre-coated transparent PET substrate using a coating process, and a pre-formed film is obtained after cooling; S3: Perform thermosetting treatment on the preformed film to cross-link and set the coating; S4: The cured film surface is matte treated to obtain the transparent frosted film.

[0023] By adopting the above technical solution, a complete and transparent frosted film preparation process has been realized. By standardizing the preparation, coating, heat curing and matte treatment of the frosted base material step by step, the reasonable connection of each step is ensured, and the key parameters in the preparation process (such as the oxygen content in the reaction vessel) are effectively controlled, and a transparent frosted film that meets the preset performance requirements is finally obtained.

[0024] As a further aspect of the present invention, the preset performance indicators include: longitudinal and transverse tensile strength not lower than preset strength values, longitudinal elongation at break not lower than preset longitudinal elongation values, transverse elongation at break not lower than preset transverse elongation values, coating adhesion grade 0, backplate and EVA peel strength not lower than preset peel strength values, longitudinal and transverse thermal shrinkage rates not higher than preset shrinkage rate values, breakdown voltage not lower than preset voltage values, water vapor transmittance not higher than preset transmittance values, and light transmittance not lower than preset light transmittance values.

[0025] By adopting the above technical solution, the specific preset performance index range of the transparent frosted film is clearly achieved. By clearly defining various properties such as tensile strength, elongation at break, and adhesion, it is ensured that the film material can meet the actual use requirements of small photovoltaic modules and guarantee the stability and reliability of the film material under different working conditions.

[0026] As a further aspect of the present invention: the transparent frosted film is adapted to small photovoltaic modules for scenarios such as small street light power generation and solar mobile charging equipment. The small photovoltaic modules also include solar outdoor charging panel modules and outdoor distributed power generation modules for the domestic low-end market.

[0027] By adopting the above technical solutions, the specific applicable scenarios and corresponding small photovoltaic module types of the transparent frosted film are clearly defined, further limiting the application scope of the film material and ensuring that the film material can accurately match the usage needs of different small photovoltaic modules, thereby improving the practicality and adaptability of the film material.

[0028] Compared with the prior art, the beneficial effects of the present invention are: This invention employs a one-sided coating process, which reduces one coating step compared to traditional processes, resulting in controllable costs and high energy absorption efficiency. This invention uses a membrane material with a built-in frosted structure to reduce glare interference under strong light, helping photovoltaic modules to efficiently absorb solar energy and improve the power generation efficiency of photovoltaic modules. This invention ensures that the transparent frosted film has good mechanical, optical, weather resistance and insulation properties by rationally matching the coating formula, standardizing the preparation process and clarifying multi-dimensional performance indicators. It has stable performance and strong adaptability, and can be accurately adapted to small photovoltaic modules in various scenarios such as small street light power generation and solar mobile charging equipment.

[0029] Other features and advantages of the present invention will be disclosed in detail in the following detailed description and accompanying drawings. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of a transparent frosted film in an embodiment of the present invention. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] The transparent frosted film prepared in this study possesses excellent wear resistance, protective properties, and lightweight characteristics, making it precisely adaptable to small photovoltaic modules and providing technical support for the application of small photovoltaic modules in various scenarios. In small street light power generation scenarios, this transparent frosted film covers the surface of photovoltaic modules. It can reduce glare interference under strong light through a special frosted structure, ensuring that the modules can efficiently absorb solar energy. It can also resist the wear and tear of outdoor wind, sand and rain on the modules, extend the service life of the street light power generation system, and help outdoor lighting achieve a stable supply of clean energy. In lightweight products such as solar-powered mobile phone charging devices and solar outdoor charging panels, the lightweight design and good flexibility of the membrane material can be adapted to the compact structure and mobile use needs of these portable devices. It does not increase the overall weight of the device, but also provides scratch protection for the photovoltaic modules, ensuring that the device can continuously convert solar energy into electrical energy in outdoor travel, camping, exploration and other scenarios to meet the instant charging needs of mobile phones and small electronic devices. Meanwhile, this transparent frosted film has a low manufacturing cost and is highly compatible with small photovoltaic modules for outdoor distributed power generation in the domestic low-end market. It can cover the surface of photovoltaic modules in scenarios such as family courtyards, small shops, and rural public areas. While ensuring the basic power generation efficiency of the modules, it reduces the overall equipment cost and provides an economical and reliable supplementary power solution for these scenarios, helping to achieve local energy production and efficient utilization.

[0033] See Figure 1 As shown in the embodiment of the present invention, a transparent frosted film is included, which is mainly used in small photovoltaic modules and is suitable for various scenarios such as small street light power generation, solar mobile charging equipment, solar outdoor charging panel modules, and outdoor distributed power generation modules for the domestic low-end market. Its overall structure and manufacturing process are as follows: First, a pre-coated transparent PET substrate is selected as the base substrate for the membrane material. This substrate possesses excellent transparency and basic mechanical properties, ensuring the performance of subsequent coating processes and the overall membrane material. Simultaneously, a coating formulation suitable for a single-sided coating process is prepared. This formulation includes a main film-forming agent, a UV absorber, and other additives. The main film-forming agent is a hydroxyl-containing fluorocarbon resin, which effectively provides the membrane material with good weather resistance and coating adhesion, facilitating the cross-linking and curing of subsequent coatings and ensuring the stability of the membrane coating.

[0034] The preparation of coating formulations must follow specific environmental requirements and mixing order: the preparation environment must meet the preset temperature, preset humidity, and preset cleanliness requirements, and the preparation area must be well-ventilated, away from fire sources and static electricity, to avoid adverse environmental factors affecting the formulation performance; the mixing order is to first add the main film-forming material, then add the UV absorber diluted with solvent, and finally add other additives to ensure that all components are fully integrated, ensuring the uniformity and stability of the formulation. Each component is prepared according to the preset mass ratio to ensure that the formulation is suitable for the coating process and film material performance requirements.

[0035] After the formula is prepared, the frosted coating liquid is applied to the pre-coated transparent PET substrate using a one-sided coating process. The coating process can be selected from one of the following: micro-gravure coating, comma blade coating, and slot coating. Through the corresponding and suitable coating equipment, the frosted coating liquid is accurately and evenly transferred to one side of the pre-coated transparent PET substrate to ensure that the coating thickness is uniform and without defects, and that the coated surface is a transparent coating to ensure the transparency of the film material and meet the light transmission requirements of photovoltaic modules.

[0036] After coating, the subsequent processing of the transparent frosted film is completed according to the preset preparation steps. The specific sub-steps are as follows: S1: To prepare the abrasive base material, the solvent and resin particles are mixed. First, the reaction vessel is purged with nitrogen to control the oxygen content in the vessel to be lower than the preset ratio, so as to avoid the oxygen content being too high and affecting the performance of the base material. Then, the mixture is premixed, dispersed at high speed, degassed, filtered and concentrated to ensure that the abrasive base material has a uniform texture and is free of impurities. S2: The prepared frosted base material is coated onto a pre-coated transparent PET substrate using the above coating process. After coating, a cooling treatment is performed to obtain a pre-formed film. S3: The preformed film is subjected to thermosetting treatment to cross-link and fix the coating on the film surface, further improving the adhesion and stability of the coating; S4: The cured film surface is matte-treated to form a frosted structure. This frosted structure can reduce glare interference under strong light and help photovoltaic modules absorb solar energy efficiently, ultimately resulting in a transparent frosted film that meets the requirements.

[0037] The final transparent frosted film must meet various preset performance indicators, including: longitudinal and transverse tensile strength not lower than preset strength values; longitudinal elongation at break not lower than preset longitudinal elongation values; transverse elongation at break not lower than preset transverse elongation values; coating adhesion grade 0; backsheet and EVA peel strength not lower than preset peel strength values; longitudinal and transverse thermal shrinkage rates not higher than preset shrinkage rates; breakdown voltage not lower than preset voltage values; water vapor transmittance not higher than preset transmittance values; and light transmittance not lower than preset light transmittance values. By limiting these performance indicators, the film material is ensured to have good mechanical properties, optical properties, weather resistance, and insulation properties, enabling it to stably adapt to the usage requirements of various small photovoltaic modules for a long time. At the same time, the application of one-sided coating process effectively reduces the manufacturing cost and enhances the market competitiveness of the film material.

[0038] In this embodiment, the following technical specifications are included: (1) Tensile strength (longitudinal MD, transverse TD): ≥80MPa; (2) Elongation at break (longitudinal MD, transverse TD): MD≥100%, TD≥80%; (3) Coating adhesion (coating type): Grade 0; (4) Peel strength of backing plate / EVA: ≥60 (5) Thermal shrinkage rate (MD in the longitudinal direction and TD in the transverse direction): ≤1.5% (6) Breakdown voltage: ≥16kV (7) Water vapor transmission rate: ≤3.0g / (m2·24h) (8) Light transmittance: ≥85% It also includes the following parameters: preset temperature: 20-25℃; preset humidity: 40%-60%; preset cleanliness: Class 10,000 cleanliness; Preset ratio, i.e., oxygen content in the reactor: ≤50ppm; Preset mass ratio: 60%-80% for the main film-forming agent, 5%-10% for the UV absorber, and 10%-35% for other additives.

[0039] In this embodiment, the coating formulation includes: (1) Introduction to the mixing ratio: Fluorocarbon resin (main film-forming material): accounting for 50%-70%, providing weather resistance and adhesion. Fluorocarbon resins containing hydroxyl groups are preferred to facilitate subsequent cross-linking and curing.

[0040] UV absorber: Add 1%-3%, and dilute with a small amount of solvent (such as ethyl acetate) in advance to avoid uneven dispersion caused by direct addition.

[0041] Other additives: leveling agent (0.5%-1%), defoamer (0.3%-0.8%), mixed in the following order: first add resin, then add diluted UV absorber, and finally add additives.

[0042] (2) Environmental requirements for preparation: Temperature: Control at 23℃±2℃. Too high a temperature will cause the solvent to evaporate too quickly, resulting in pinholes in the coating; too low a temperature will increase the resin viscosity and affect leveling.

[0043] Humidity: Maintain 40%-60%. If the humidity exceeds 70%, the coating will easily absorb moisture from the air, resulting in pinholes or white fog after curing. If the humidity is below 30%, static electricity may be generated, attracting dust.

[0044] Cleanliness: Operation must be performed in a Class 10,000 cleanroom; Configuration area: Requires good ventilation, explosion-proof exhaust fans can be installed, avoids the accumulation of vapors of organic solvents such as ethyl acetate and methyl ethyl ketone, and keeps away from fire sources and static electricity.

[0045] In this embodiment, the coating method selected is microgravure coating: microgravure coating takes a gravure roller with tiny grooves as the core. The gravure roller is partially immersed in the coating liquid and picks up the coating when rotating. Excess coating is scraped off by a flexible scraper, leaving only the coating in the grooves. Then the gravure roller moves in the opposite direction to the pre-coated PET substrate. Under the light pressure of the bonding roller, the frosted coating liquid in the grooves is accurately transferred to one side of the substrate, achieving uniform coating.

[0046] Example 1 S1. 37.2 parts by weight of ethyl acetate solvent, 60 parts by weight of hydroxyl-containing fluorocarbon resin (main film-forming material), 2 parts by weight of UV absorber diluted with ethyl acetate, 0.5 parts by weight of leveling agent, and 0.3 parts by weight of defoamer are added sequentially into the reactor. The reactor is then purged with nitrogen to ensure that the oxygen content inside the reactor is below 2%. The dissolution temperature was controlled at 150℃ and the dissolution time was 4h. First, the resin was premixed for 30min at a stirring rate of 80r / min (to allow the resin and solvent to initially blend). Then, the resin was stirred at a high speed of 1800r / min (to ensure that the additives were evenly dispersed). After that, the resin was degassed, filtered, and concentrated to a fine sand base material with a solid content of 10%. S2. The frosted base material is coated onto a PET transparent backing substrate at 80°C using a micro-gravure coating method, with the coating thickness controlled at 30μm and the coating speed at 15m / min. After natural cooling to room temperature, a pre-formed film is obtained. S3. The preformed film is subjected to heat curing treatment at 120°C for 2 hours to crosslink and set the frosted coating. S4. After curing, the film surface is matte treated by lightly pressing it with a 2000-mesh frosted roller to finally obtain a PET transparent backing frosted film.

[0047] Example 2 S1. 36.7 parts by weight of xylene solvent, 60 parts by weight of hydroxyl-containing fluorocarbon resin, 2.5 parts by weight of ultraviolet absorber diluted with xylene, 0.6 parts by weight of leveling agent, and 0.2 parts by weight of defoamer are added sequentially into the reactor, and nitrogen is used to replace the oxygen content in the reactor to be less than 2%. The dissolution temperature was controlled at 160℃ and the dissolution time was 5h. The mixture was first premixed at 100r / min for 40min, then dispersed at 2000r / min at high speed. After degassing and filtration, it was concentrated to a fine sand base material with a solid content of 12%. S2. The frosted base material is coated onto a PET transparent backing at 85°C using a comma-shaped scraper coating method, with the coating thickness controlled at 25μm and the coating speed at 20m / min. The coating is then cooled to room temperature to obtain a pre-formed film. S3. The preformed film is heat-cured at 130°C for 1.5 hours to complete the coating shaping; S4. The film surface is subjected to matte treatment by 1800-mesh frosted roller to obtain a PET transparent backing frosted film.

[0048] Example 3 S1. 37.0 parts by weight of butyl acetate solvent, 60 parts by weight of hydroxyl-containing fluorocarbon resin, 2.2 parts by weight of UV absorber diluted with butyl acetate, 0.5 parts by weight of leveling agent, and 0.3 parts by weight of defoamer are added sequentially into the reactor. After nitrogen purging, the oxygen content is less than 2%. The dissolution temperature was controlled at 155℃ and the dissolution time was 4.5h. The mixture was first premixed at 90r / min for 35min, then dispersed at 1900r / min at high speed. After degassing and filtration, it was concentrated to a fine sand base material with a solid content of 11%. S2. The frosted base material is coated onto a PET transparent backing at 82°C using a slot coating method, with the coating thickness controlled at 28μm and the coating speed at 18m / min. The film is then cooled to room temperature to obtain a pre-formed film. S3. The preformed film is heat-cured at 125°C for 1.8 hours to achieve coating crosslinking; S4. A 2200-mesh frosted roller is used to matte the film surface to obtain a PET transparent backing frosted film.

[0049] Comparative Example 1 S1. 37.2 parts by weight of ethyl acetate solvent, 60 parts by weight of hydroxyl-containing fluorocarbon resin, 2 parts by weight of UV absorber diluted with ethyl acetate, 0.5 parts by weight of leveling agent, and 0.3 parts by weight of defoamer are added sequentially into the reactor. The oxygen content in the reactor is not controlled. The dissolution temperature was controlled at 150℃ and the dissolution time was 4h. The mixture was first premixed at a stirring rate of 80r / min for 30min, then stirred at a high speed at a dispersion rate of 1800r / min, followed by degassing, filtration, and concentration to a fine sand base material with a solid content of 10%. S2. The frosted base material is coated onto a PET transparent backing substrate at 80°C using a micro-gravure coating method, with the coating thickness controlled at 30μm and the coating speed at 15m / min. After natural cooling to room temperature, a pre-formed film is obtained. S3. The preformed film is subjected to heat curing treatment at 120°C for 2 hours to crosslink and set the frosted coating. S4. After curing, the film surface is matte treated by lightly pressing it with a 2000-mesh frosted roller to obtain a PET transparent backing frosted film.

[0050] Comparative Example 2 S1. 36.7 parts by weight of xylene solvent, 60 parts by weight of hydroxyl-containing fluorocarbon resin, 2.5 parts by weight of ultraviolet absorber diluted with xylene, 0.6 parts by weight of leveling agent, and 0.2 parts by weight of defoamer are added sequentially into the reactor, and nitrogen is used to replace the oxygen content in the reactor to be less than 2%. The dissolution temperature was controlled at 160℃ and the dissolution time was 5h. The mixture was first premixed at 100r / min for 40min, then dispersed at 2000r / min at high speed. After degassing and filtration, it was concentrated to a fine sand base material with a solid content of 12%. S2. The frosted base material is coated onto a PET transparent backing at 85°C using a comma-shaped scraper coating method, with the coating thickness controlled at 25μm and the coating speed at 20m / min. The coating is then cooled to room temperature to obtain a pre-formed film. S3. The preformed film is heat-cured at 150°C for 1.5 hours to complete the coating shaping; S4. The film surface is subjected to matte treatment by 1800-mesh frosted roller to obtain a PET transparent backing frosted film.

[0051] PET Transparent Backing Frosted Film Performance Test Table This invention provides a transparent frosted film that can stably adapt to the usage requirements of various small photovoltaic modules over a long period of time. At the same time, the application of a one-sided coating process effectively reduces the manufacturing cost and ensures high reliability.

[0052] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0053] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is only for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A transparent frosted film, characterized in that, A pre-coated transparent PET substrate is used, wherein PET is polyethylene terephthalate, which is prepared by a one-sided coating process. The coating process is matched with a coating formulation containing a main film-forming material, a UV absorber and other additives. The coating surface is a transparent coating to ensure the transparency of the back panel. The aforementioned one-sided coating process reduces one coating layer compared to the traditional process, and the film material includes a frosted structure to reduce glare interference under strong light. The photovoltaic module achieves efficient solar energy absorption through the film material. The transparent frosted film is required to meet preset performance indicators, including mechanical properties, optical properties, weather resistance and insulation properties.

2. The transparent frosted film according to claim 1, characterized in that, The main film-forming material includes a hydroxyl-containing fluorocarbon resin, which provides weather resistance and adhesion, facilitating subsequent cross-linking and curing.

3. The transparent frosted film according to claim 1, characterized in that, The mixing steps of the coating formulation include: first adding the main film-forming material, then adding the UV absorber diluted with solvent, and finally adding other additives.

4. The transparent frosted film according to claim 1, characterized in that, The preparation environment requirements for the coating formulation include: meeting preset temperature, preset humidity, and preset cleanliness requirements, and ensuring that the preparation area is well-ventilated and away from fire sources and static electricity.

5. The transparent frosted film according to claim 1, characterized in that, The coating process employs one of the following: micro-recessed coating, comma blade coating, and slot coating. The corresponding coating equipment is used to precisely transfer the frosted coating liquid to one side of the pre-coated transparent PET substrate to achieve uniform coating.

6. The transparent frosted film according to claim 1, characterized in that, The preparation steps include the following sub-steps: S1: Prepare the abrasive base material by mixing the solvent with the resin particles, purging the reaction vessel with nitrogen to control the oxygen content in the vessel to be lower than the preset ratio, and then premixing, high-speed dispersion, degassing, filtering and concentration. S2: The frosted base material is coated onto a pre-coated transparent PET substrate using a coating process, and a pre-formed film is obtained after cooling; S3: Perform thermosetting treatment on the preformed film to cross-link and set the coating; S4: The cured film surface is matte treated to obtain the transparent frosted film.

7. The transparent frosted film according to claim 1, characterized in that, The preset performance indicators include: longitudinal and transverse tensile strength not lower than preset strength values, longitudinal elongation at break not lower than preset longitudinal elongation values, transverse elongation at break not lower than preset transverse elongation values, coating adhesion grade 0, backsheet and EVA peel strength not lower than preset peel strength values, longitudinal and transverse thermal shrinkage rates not higher than preset shrinkage rate values, breakdown voltage not lower than preset voltage values, water vapor transmission rate not higher than preset transmission rate values, and light transmittance not lower than preset light transmittance values, wherein EVA is an ethylene-vinyl acetate copolymer.

8. The transparent frosted film according to claim 1, characterized in that, The transparent frosted film is suitable for small photovoltaic modules in scenarios such as small street light power generation and solar mobile charging equipment. The small photovoltaic modules also include solar field charging panel modules and outdoor distributed power generation modules for the domestic low-end market.

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