An encapsulation cover plate, a manufacturing method thereof, and a photovoltaic module

Abstract

The present invention discloses a packaging cover plate, a manufacturing method thereof, and a photovoltaic module, relating to the field of photovoltaic technology, so that the packaging cover plate has flexibility while having good impact resistance. The packaging cover plate is applied to a photovoltaic module, and the packaging cover plate includes a weather-resistant layer and an impact-resistant layer attached to the weather-resistant layer; the material of the impact-resistant layer is a composite material with an interpenetrating network structure. The packaging cover plate, the manufacturing method thereof, and the photovoltaic module provided by the present invention are used for manufacturing a photovoltaic module.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic technology, and particularly to a packaging cover plate, a manufacturing method thereof, and a photovoltaic module. Background Art

[0002] In order to better combine photovoltaic modules with buildings, etc., the packaging cover plates of photovoltaic modules are developing towards the direction of light weight and flexibility. After replacing glass with such light-weight and flexible packaging cover plates, not only can the weight of the photovoltaic module be reduced, but also good flexibility can be achieved.

[0003] However, among the existing light-weight and flexible cover plates, when they have flexibility, there are often problems of poor impact resistance. Summary of the Invention

[0004] The purpose of the present invention is to provide a packaging cover plate, a manufacturing method thereof, and a photovoltaic module, so that while the packaging cover plate has flexibility, it has good impact resistance.

[0005] In the first aspect, the present invention provides a packaging cover plate. This packaging cover plate is applied to a photovoltaic module, and the packaging cover plate includes a weather-resistant layer and an impact-resistant layer attached to the weather-resistant layer; the material of the impact-resistant layer is a composite material with an interpenetrating network structure.

[0006] When adopting the above technical solution, the packaging cover plate includes an impact-resistant layer, and the material of the impact-resistant layer is a composite material with an interpenetrating network structure. From a microscopic perspective, the impact-resistant layer has a three-dimensional interpenetrating network structure. This three-dimensional interpenetrating network structure is formed by at least two cross-linked networks interpenetrating each other, and has the characteristics of high elasticity and impact resistance, so that the impact-resistant layer has high elasticity and impact resistance. Based on this, on the one hand, the high-elasticity performance of the impact-resistant layer enables it to absorb impact energy and reduce the damage of mechanical impact to the packaging cover plate; on the other hand, the impact-resistant performance of the impact-resistant layer enables it to withstand a large impact force and reduce the probability of the packaging cover plate breaking. It can be seen that the impact-resistant layer of the present invention has good impact resistance. And, the weather-resistant layer can provide good climate tolerance for the packaging cover plate. The packaging cover plate combining the weather-resistant layer and the impact-resistant layer has good climate tolerance and impact resistance, can provide good protection for the solar cell module of the photovoltaic module, reduce the probability of debris, and ensure the performance of the photovoltaic module.

[0007] In addition, the interpenetrating network structure has good stability, is not sensitive to temperature, and is not easily thermally degraded, so it can have good heat resistance, can reduce the problems of deformation and aging of the packaging cover plate, and improve the service life of the packaging cover plate.

[0008] In some implementations, the composite material includes a flexible component and a rigid component. The flexible component and the rigid component are intertwined to form an interpenetrating network structure, and the mass ratio of the flexible component to the rigid component is 1:(1 - 2). At this time, the flexible component and the rigid component are evenly distributed in the composite material. The flexible component can provide good elasticity for the impact-resistant layer and effectively absorb impact energy. The rigid component can endow the impact-resistant layer with good rigidity, so that the impact-resistant layer can withstand a large impact force and reduce the probability of the impact-resistant layer breaking. When the flexible component and the rigid component are combined in the above ratio, the characteristics of absorbing impact energy and withstanding impact of the impact-resistant layer can be better combined, so as to achieve the purpose of impact resistance.

[0009] In some implementations, the flexible component includes polyurethane or polyorganosiloxane. At this time, polyurethane and polyorganosiloxane, as one of the materials of the impact-resistant layer, not only have good elasticity, but also have a simple and mature manufacturing method, which is convenient for industrial application. In addition, during the process of manufacturing the impact-resistant layer, these flexible components can play a buffering role and release thermal stress, which can further reduce the problem of photovoltaic module breakage. The rigid component includes acrylate. At this time, acrylate has good heat resistance, water resistance and ultraviolet resistance. When it is used as one of the materials of the encapsulation cover plate, it can not only improve the ability of the impact-resistant layer to withstand mechanical impact, but also improve the barrier effect of the entire impact-resistant layer and the encapsulation cover plate against the external humid and hot environment, and improve the protection performance of the encapsulation cover plate.

[0010] In some implementations, the polyurethane includes at least one of ester-type polyurethane and ether-type polyurethane.

[0011] In some implementations, the composite material further includes a reinforcing material. At this time, the addition of the reinforcing material can improve the mechanical properties of the composite material, that is, the impact-resistant layer, and reduce the probability of the impact-resistant layer breaking. Moreover, when the reinforcing material is combined with the interpenetrating network structure intertwined by the rigid component and the flexible component, the interpenetrating network structure can further disperse and fix the reinforcing material, thereby improving the mechanical properties of the entire impact-resistant layer. The mass of the reinforcing material is 1 / 3 to 2 / 3 times the sum of the masses of the flexible component and the rigid component. At this time, the mass of the reinforcing material is appropriate, which can maximize the mechanical properties of the composite material while ensuring the stability of the composite material matrix. The reinforcing material is 0D, 1D, 2D or 3D; the reinforcing material is a transparent material or a colored material.

[0012] In some implementations, the reinforcing material includes one or more of glass microspheres, short glass fibers, glass fibers, polymer fiber materials, two-dimensional materials woven from polymer fibers, and three-dimensional materials woven from polymer fibers. When the reinforcing material is an inorganic material such as glass microspheres, the heat resistance of the entire impact-resistant layer can be improved, and the probability of thermal degradation can be reduced. In addition, when the glass microspheres are selected as the reinforcing material, the growth of cracks can be effectively organized, further preventing the impact-resistant layer from cracking, and further improving the impact resistance of the impact-resistant layer.

[0013] In some implementations, the material of the weather-resistant layer is one or more of ETFE, ECTFE, PVDF, PVF, FEP, PET, or PC. The thickness of the weather-resistant layer is 20 μm to 500 μm. At this time, the thickness of the weather-resistant layer is relatively large, which can better protect the impact-resistant layer and the solar cell module, and reduce the adverse effects of the external climate environment. The light transmittance of the weather-resistant layer is greater than or equal to 90%. At this time, the weather-resistant layer has good light transmittance and little blocking effect on sunlight, which can ensure the light absorption rate of the solar cell to be protected. The impact-resistant layer is transparent.

[0014] In some implementations, the encapsulation cover plate serves as the front encapsulation cover plate or the rear encapsulation cover plate of the photovoltaic module.

[0015] In a second aspect, the present invention provides a method for manufacturing the encapsulation cover plate described in the first aspect or any implementation manner of the first aspect. The manufacturing method includes the following steps:

[0016] Provide a first mixture, which is formed by mixing reactants of flexible components, crosslinking catalysts for flexible components, monomers of rigid components, crosslinking initiators for rigid components, and reinforcing materials;

[0017] Provide a weather-resistant layer; attach the first mixture to the surface of the weather-resistant layer to obtain a prefabricated cover plate;

[0018] Treat the prefabricated cover plate at a first temperature to carry out a first crosslinking reaction;

[0019] Treat the prefabricated cover plate at a second temperature to carry out a second crosslinking reaction to obtain an encapsulation cover plate; wherein, the first temperature is less than the second temperature.

[0020] The beneficial effects of the method for manufacturing the encapsulation cover plate provided in the second aspect can refer to the beneficial effects of the encapsulation cover plate described in the first aspect or any implementation manner of the first aspect.

[0021] In some embodiments, the surface energy of the weather-resistant layer is greater than or equal to 38 dynes. At this time, the surface energy of the weather-resistant layer is relatively large. When the first mixture contacts the weather-resistant layer, the surface activity of the weather-resistant layer is relatively large, which can cause the molecules on the surface of the weather-resistant layer to form stable chemical bonds with the first mixture, thereby enabling the bonding strength between the weather-resistant layer and the first mixture, that is, between the weather-resistant layer and the impact-resistant layer.

[0022] In some embodiments, providing a weather-resistant layer includes: surface-treating the weather-resistant layer; the surface treatment includes at least one of corona treatment, plasma treatment, and flame treatment. Surface-treating the weather-resistant layer can form active functional groups such as hydroxyl groups on the surface of the weather-resistant layer. These active functional groups can form chemical bonds with some substances in the first mixed material, thereby improving the adhesion of the first mixture to the weather-resistant layer.

[0023] In some embodiments, the reactants of the flexible component include polyether polyols, small molecule polyols, and hexamethylene diisocyanate; the crosslinking catalyst for the flexible component is an organotin catalyst; the rigid component monomers include one or more of methyl acrylate, ethyl acrylate, n-butyl acrylate, methyl methacrylate, n-butyl methacrylate, and acrylic acid-modified bisphenol A epoxy resin; the crosslinking initiator for the rigid component is a peroxide initiator or an azo initiator, wherein the azo initiators include one or more of azobisisobutyronitrile, azobisisopentanenitrile, and azobisisoheptanenitrile.

[0024] In some embodiments, providing the first mixture includes: mixing polyether polyols and small molecule polyols at 50 °C to 70 °C; adding hexamethylene diisocyanate after cooling to obtain a second mixture; mixing the rigid component monomers, the rigid component crosslinking initiator, and the flexible component crosslinking catalyst to obtain a third mixture; in the second mixture, first adding the reinforcing material and then adding the third mixture to obtain the first mixture. When obtaining the first mixture in the above manner, first forming the second mixture and then adding the reinforcing material can omit the solvent required to dissolve the reinforcing material and avoid introducing impurities. Finally adding the third mixture, that is, finally adding the flexible component crosslinking catalyst, can prevent the flexible component from crosslinking when not evenly mixed, which is beneficial to fabricating a composite material with a better interpenetrating network structure.

[0025] In some embodiments, the method of attaching the first mixture to the surface of the weather-resistant layer is: pouring, coating, or printing.

[0026] In some implementations, the device for attaching the first mixture to the surface of the weather-resistant layer is a coating mold; the coating mold is formed by detachably enclosing multiple side walls, the shape enclosed by the coating mold is the same as the shape of the weather-resistant layer, and the size of the coating mold matches the size of the weather-resistant layer. At this time, using the coating mold can not only fix the weather-resistant layer, but also limit the flow range of the first mixture, avoid the first mixture exceeding the surface range of the weather-resistant layer, and thus improve work efficiency.

[0027] In some implementations, the first cross-linking reaction is a flexible component cross-linking reaction, the first temperature is 40°C to 50°C, and the time for treating the prefabricated cover plate at the first temperature is 10 min to 60 min; the second cross-linking reaction is a rigid component cross-linking reaction; the second temperature is 80°C to 100°C; the time for treating the prefabricated cover plate at the second temperature is 10 min to 60 min. At this time, the flexible component cross-linking reaction and the rigid component cross-linking reaction are carried out step by step. The network structure formed in the first cross-linking reaction can play a role in dispersing and fixing the uncross-linked materials, so that the components in the composite material can be evenly dispersed, and the performance stability of the impact-resistant layer can be improved. Moreover, the first temperature is lower than the second temperature, which can avoid the premature occurrence of the second cross-linking reaction.

[0028] In some implementations, the first temperature is 20°C to 30°C, and the second temperature is 120°C to 160°C.

[0029] In some implementations, the second cross-linking reaction is completed in the lamination process of the photovoltaic module. At this time, the process steps can be saved, the production efficiency can be improved, and the energy consumption generated by heating can be reduced, saving resources.

[0030] In a third aspect, the present invention provides a photovoltaic module. The photovoltaic module includes the encapsulation cover plate described in the first aspect or any implementation of the first aspect.

[0031] For the beneficial effects of the photovoltaic module provided in the third aspect, reference can be made to the beneficial effects of the encapsulation cover plate described in the first aspect or any implementation of the first aspect, and details will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0033] Figure 1 is a schematic structural diagram of the encapsulation cover plate provided by an embodiment of the present invention;

[0034] Figure 2 is a top view schematic diagram of the encapsulation cover plate provided by an embodiment of the present invention;

[0035] Figure 3 Structural schematic diagram of the coating mold provided by the embodiment of the present invention;

[0036] Figure 4 Structural schematic diagram of the photovoltaic module provided by the embodiment of the present invention.

[0037] Reference numerals:

[0038] Figures 1 to 4 Among them, 11 - weather-resistant layer, 12 - impact-resistant layer, 121 - reinforcing particles, 21 - front encapsulation cover plate, 22 - first encapsulation adhesive film, 23 - solar cell module, 24 - second encapsulation adhesive film, 25 - rear encapsulation cover plate, A - coating mold, A01 - side wall. Detailed implementation manners

[0039] For the convenience of clearly describing the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, terms such as "first" and "second" are used to distinguish the same items or similar items with basically the same functions and effects. Those skilled in the art can understand that the terms such as "first" and "second" do not limit the quantity and execution order, and the terms such as "first" and "second" do not necessarily limit being different.

[0040] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present invention.

[0041] It should be noted that in the present invention, words such as "exemplary" or "for example" are used to represent examples, illustrations or explanations. Any embodiment or design solution described as "exemplary" or "for example" in the present invention should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Exactly, using words such as "exemplary" or "for example" is intended to present relevant concepts in a specific manner.

[0042] In the present invention, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the relationship between associated objects and indicates that there can be three relationships. For example, A and / or B can represent the cases of A existing alone, A and B existing simultaneously, and B existing alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one (item)" or similar expressions refer to any combination of these items, including any combination of single item(s) or plural item(s). For example, at least one (item) of a, b, or c can represent: a, b, c, the combination of a and b, the combination of a and c, the combination of b and c, or the combination of a, b, and c, where a, b, and c can be single or multiple.

[0043] Combining photovoltaic module products with buildings to construct energy-saving buildings is an important means to reduce carbon emissions and save energy. There are more and more technical researches on the combination of photovoltaic modules and buildings. Due to the diversity of the surface structure of buildings, the corresponding photovoltaic module products also need to be flexible and have a low weight. Currently, most photovoltaic modules use polymer films or composite materials as lightweight and flexible encapsulation covers to replace glass, in order to reduce the weight of the photovoltaic module and ensure the flexibility of the entire photovoltaic module. However, this type of photovoltaic module has poor mechanical strength and poor resistance to mechanical impact. In case of hail weather, the batteries in the entire photovoltaic module are easily cracked, resulting in a serious decline in the performance of the photovoltaic module.

[0044] The encapsulation cover is an important component in the entire encapsulation system and has a significant impact on the impact resistance of the entire photovoltaic module. In the prior art, a weather-resistant powder coating is applied to a fiber cloth, and the weather-resistant powder is bonded to the fiber cloth through hot pressing, and then cutting can obtain a lightweight and flexible encapsulation cover. However, this solution not only has a complex preparation process and it is difficult to coat the powder coating evenly; moreover, it is difficult to fix the position of the fiber cloth, and the position of the fiber cloth in the encapsulation cover is not uniform, resulting in large fluctuations in the performance of the encapsulation cover. And there are also problems of poor impact resistance and poor heat resistance. The photovoltaic module made with this encapsulation cover has a large thermal stress, and the photovoltaic module is prone to serious deformation, causing cracking of the battery chips.

[0045] To solve the above technical problems, an embodiment of the present invention provides an encapsulation cover. This encapsulation cover is applied to a photovoltaic module. Specifically, it is used to encapsulate the solar cell module 23 to form a photovoltaic module.

[0046] As Figure 1 shown, the above encapsulation cover includes a weather-resistant layer 11 and an impact-resistant layer 12 attached to the weather-resistant layer 11; the material of the impact-resistant layer 12 is a composite material with an interpenetrating network structure.

[0047] Based on the above structure, it can be known that the encapsulation cover plate includes an impact-resistant layer 12, and the material of the impact-resistant layer 12 is a composite material with an interpenetrating network structure. From a microscopic perspective, the impact-resistant layer 12 has a three-dimensional interpenetrating network structure. This three-dimensional interpenetrating network structure is formed by the interpenetration of at least two cross-linked networks, and has the characteristics of high elasticity and impact resistance, so that the impact-resistant layer 12 has high elasticity and impact resistance. Based on this, on the one hand, the high-elasticity performance of the impact-resistant layer 12 enables it to absorb impact energy and reduce the damage of mechanical impact to the encapsulation cover plate; on the other hand, the impact-resistant performance of the impact-resistant layer 12 enables it to withstand a large impact force and reduce the probability of the encapsulation cover plate breaking. It can be seen that the impact-resistant layer 12 of the present invention has good impact resistance. Moreover, the weather-resistant layer 11 can provide good climate tolerance for the encapsulation cover plate. The encapsulation cover plate combining the weather-resistant layer 11 and the impact-resistant layer 12 has good climate tolerance and impact resistance, can provide good protection for the solar cell module of the photovoltaic module, reduce the probability of fragmentation, and ensure the performance of the photovoltaic module.

[0048] In addition, the interpenetrating network structure has good stability, is not sensitive to temperature, and is not easily thermally degraded, so it can have good heat resistance, can reduce the problems of deformation and aging of the encapsulation cover plate, and improve the service life of the encapsulation cover plate.

[0049] The above encapsulation cover plate can be used as the front encapsulation cover plate of the photovoltaic module or the rear encapsulation cover plate. At this time, according to actual needs, the encapsulation cover plate can be used to encapsulate and protect the front, back or both the front and back of the photovoltaic module. When one side of the photovoltaic module selects the encapsulation cover plate provided by the embodiment of the present invention, the other side can select encapsulation materials such as glass. The above-mentioned impact-resistant layer 12 made of composite material can be transparent so as to be used as the front encapsulation cover plate.

[0050] The material of the above weather-resistant layer 11 can be one or more of ethylene-tetrafluoroethylene copolymer (ETFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), polyvinylidene fluoride (PVDF), polyvinyl formal (PVF), fluorinated ethylene propylene copolymer (FEP), polyester resin (PET), or polycarbonate (PC). At this time, no matter which weather-resistant material is selected, it can provide good climate tolerance for the encapsulation cover plate.

[0051] The light transmittance of the above weather-resistant layer 11 can be greater than or equal to 90%. For example, the light transmittance of the weather-resistant layer 11 can be 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, etc. At this time, the weather-resistant layer 11 has good light transmission performance and little blocking effect on sunlight, and can ensure the light absorption rate of the solar cell to be protected.

[0052] When selecting the material of the weather-resistant layer 11, it can be selected according to the usage of the encapsulation cover plate. For example, when the encapsulation cover plate is used on the front side of a single-sided power generation photovoltaic module or a double-sided power generation photovoltaic module, a weather-resistant layer material with a relatively high light transmittance can be selected. When the encapsulation cover plate is used on the back side of a single-sided power generation photovoltaic module, a weather-resistant layer 11 material that is light-transmitting or opaque such as black can be selected.

[0053] As Figure 1 shown, the thickness of the above-mentioned weather-resistant layer 11 can be 20μm to 500μm. When the thickness of the weather-resistant layer 11 is within this range, the thickness of the weather-resistant layer 11 is relatively large, which can better protect the impact-resistant layer 12 and the solar cell module, and reduce the adverse effects of the external climate environment. For example, the thickness of the weather-resistant layer 11 can be 20μm, 80μm, 100μm, 120μm, 200μm, 250μm, 300μm, 360μm, 400μm, 450μm, 500μm, etc.

[0054] The composite material of the above-mentioned impact-resistant layer 12 includes a flexible component and a rigid component, and the flexible component and the rigid component are intertwined to form an interpenetrating network structure. The mass ratio of the flexible component to the rigid component is 1:(1 - 2). Exemplarily, the mass ratio of the flexible component to the rigid component can be 1:1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, etc. At this time, the flexible component and the rigid component are evenly distributed in the composite material. The flexible component can provide good elasticity for the impact-resistant layer 12 and effectively absorb impact energy. The rigid component can make the impact-resistant layer 12 have good rigidity, so that the impact-resistant layer 12 can withstand a large impact force and reduce the probability of the impact-resistant layer 12 breaking. When the flexible component and the rigid component are combined in the above ratio, the characteristics of the impact-resistant layer 12 absorbing impact energy and bearing impact can be better combined together, so as to achieve the purpose of impact resistance.

[0055] The above-mentioned flexible component can include any one of polyurethane or polyorganosiloxane. At this time, polyurethane and polyorganosiloxane, as one of the materials of the impact-resistant layer 12, not only have good elasticity, but also have a simple and mature manufacturing method, which is convenient for industrial application. In addition, during the process of manufacturing the impact-resistant layer 12, these flexible components can play a buffering role and release thermal stress, which can further reduce the problem of photovoltaic module breakage.

[0056] The above-mentioned polyurethane includes at least one of ester-type polyurethane and ether-type polyurethane. In practical applications, the polyurethane can be ester-type polyurethane, can also be ether-type polyurethane, or can be a mixture of ester-type polyurethane and ether-type polyurethane. The preferred polyurethane is ether-type polyurethane.

[0057] The above-mentioned rigid component includes acrylate. At this time, acrylate has good heat resistance, water resistance, and ultraviolet resistance. When it is used as one of the materials for the encapsulation cover plate, it can not only improve the ability of the impact-resistant layer 12 to withstand mechanical impacts, but also enhance the barrier effect of the entire impact-resistant layer 12 and the encapsulation cover plate against the external humid and hot environment, thereby improving the protection performance of the encapsulation cover plate.

[0058] As Figure 1 and Figure 2 shown, the above-mentioned composite material further includes a reinforcing material. At this time, the addition of the reinforcing material can improve the mechanical properties of the composite material, that is, the impact-resistant layer 12, and reduce the probability of the impact-resistant layer 12 cracking. Moreover, when the reinforcing material is combined with the interpenetrating network structure in which the rigid component and the flexible component are intertwined, the interpenetrating network structure can further disperse and fix the reinforcing material, thereby improving the mechanical properties of the entire impact-resistant layer 12.

[0059] The mass of the above-mentioned reinforcing material can be 1 / 3 to 2 / 3 times the sum of the masses of the flexible component and the rigid component. For example, the mass of the reinforcing material can be 1 / 3 times, 0.35 times, 0.4 times, 0.45 times, 0.48 times, 0.5 times, 0.55 times, 0.6 times, 0.63 times, 2 / 3 times, etc. of the sum of the masses of the flexible component and the rigid component. At this time, the mass of the reinforcing material is appropriate, which can maximize the mechanical properties of the composite material while ensuring the stability of the composite material matrix.

[0060] The above-mentioned reinforcing material is 0-dimensional, 1-dimensional, 2-dimensional, or 3-dimensional. Specifically, the reinforcing material can include one or more of glass microspheres, short glass fibers, glass fibers, polymer fiber materials, 2-dimensional materials woven from polymer fibers, and 3-dimensional materials woven from polymer fibers. Preferably, the reinforcing material can be 0-dimensional glass microspheres. When the reinforcing material is an inorganic material such as glass microspheres, it can improve the heat resistance of the entire impact-resistant layer 12 and reduce the probability of thermal degradation. In addition, when the glass microspheres are selected as the reinforcing material, it can effectively organize the growth of cracks, further prevent the impact-resistant layer 12 from cracking, and further improve the impact resistance of the impact-resistant layer 12.

[0061] The above-mentioned reinforcing material can be a transparent material or a colored material. At this time, a transparent or colored reinforcing material can be selected according to the application of the encapsulation cover plate.

[0062] Exemplarily, when the encapsulation cover plate is located on the front of the photovoltaic module, a transparent material reinforcing material can be selected. When the encapsulation cover plate is located on the back of the photovoltaic module and color decoration is required, a colored material reinforcing material can be selected, such as colored glass microspheres, colored polymer fiber materials, etc.

[0063] An embodiment of the present invention also provides a method for manufacturing the above encapsulation cover plate. The method for manufacturing the encapsulation cover plate includes the following steps:

[0064] Step S100: Provide a first mixture, which is formed by mixing reactants of the flexible component, a crosslinking catalyst for the flexible component, monomers of the rigid component, a crosslinking initiator for the rigid component, and a reinforcing material.

[0065] The above reactants of the flexible component include polyether polyols, small molecule polyols, and hexamethylene diisocyanate. The small molecule polyol can be pentaerythritol. The crosslinking catalyst for the flexible component can be an organotin catalyst. The organotin catalyst can be one or more of dibutyltin dilaurate, stannous octoate, dibutyltin bis(dodecylthiol), and dibutyltin diacetate.

[0066] The above monomers of the rigid component can include one or several of methyl acrylate, ethyl acrylate, n-butyl acrylate, methyl methacrylate, n-butyl methacrylate, and bisphenol A epoxy resin modified with acrylic acid. The crosslinking initiator for the rigid component can be a peroxide initiator or an azo initiator. The azo initiator includes one or more of azobisisobutyronitrile, azobisisopentanenitrile, and azobisisoheptanenitrile. These materials can be used to fabricate an interpenetrating network structure of polyurethane and acrylate. By using these materials, it can ensure that the crosslinking reaction proceeds stably and rapidly.

[0067] There are various ways to obtain the first mixture, as long as it is ensured to be mixed evenly. Exemplarily, in a mixing container, the reactants of the flexible component, the crosslinking catalyst for the flexible component, the monomers of the rigid component, the crosslinking initiator for the rigid component, and the reinforcing material can be added simultaneously, and the first mixture can be quickly attached to the weather-resistant layer 11.

[0068] Exemplarily, providing the first mixture includes:

[0069] Step S101: Mix polyether polyols and small molecule polyols at 50°C to 70°C; after cooling, add hexamethylene diisocyanate to obtain a second mixture. During this process, the temperature of 50°C to 70°C can enable the polyether polyols and small molecule polyols to be quickly and evenly mixed. Adding hexamethylene diisocyanate after cooling can avoid these reactants of the flexible component from reacting too quickly when they are not evenly mixed.

[0070] Step S102: Mix the monomers of the rigid component, the crosslinking initiator for the rigid component, and the crosslinking catalyst for the flexible component to obtain a third mixture. It should be understood that the order of step S101 and step S102 can be swapped.

[0071] Step S103: In the second mixture, first add the reinforcing material and then add the third mixture to obtain the first mixture. When obtaining the first mixture in the above manner, first form the second mixture and then add the reinforcing material, which can omit the solvent required to dissolve the reinforcing material and avoid introducing impurities. Finally, add the third mixture, that is, finally add the flexible component cross-linking catalyst, which can avoid cross-linking of the flexible component when it is not evenly mixed, thus facilitating the production of a composite material with a better performance and an interpenetrating network structure.

[0072] Step S200: Provide a weather-resistant layer 11. The surface energy of the weather-resistant layer 11 can be greater than or equal to 38 dynes. For example, the surface energy of the weather-resistant layer 11 can be 38 dynes, 40 dynes, 42 dynes, 45 dynes, 50 dynes, 60 dynes, 70 dynes, etc. At this time, the surface energy of the weather-resistant layer 11 is relatively large. When the first mixture contacts the weather-resistant layer 11, the surface activity of the weather-resistant layer 11 is relatively large, which can enable the molecules on the surface of the weather-resistant layer 11 to form stable chemical bonds with the first mixture, thereby enhancing the bonding strength between the weather-resistant layer 11 and the first mixture, that is, the bonding strength between the weather-resistant layer 11 and the impact-resistant layer 12.

[0073] Providing a weather-resistant layer 11 may further include: performing surface treatment on the weather-resistant layer 11; the surface treatment includes at least one of corona treatment, plasma treatment, and flame treatment. It should be understood that after performing surface treatment on the weather-resistant layer 11, the surface energy of the weather-resistant layer 11 can be greater than or equal to 38 dynes. Performing surface treatment on the weather-resistant layer 11 can form active functional groups such as hydroxyl groups on the surface of the weather-resistant layer 11. These active functional groups can form chemical bonds with some substances in the first mixed material, thereby improving the adhesion of the first mixture to the weather-resistant layer 11.

[0074] In practical applications, step S100 can be executed first, and then step S200; or step S200 can be executed first, and then step S100; or step S100 and step S200 can be executed simultaneously.

[0075] Step S300: Attach the first mixture to the surface of the weather-resistant layer 11 to obtain a prefabricated cover plate. The method of attaching the first mixture to the surface of the weather-resistant layer 11 is: pouring, coating, or printing. Since the first mixture has good fluidity, the first mixture can be quickly and evenly attached to the surface of the weather-resistant layer 11 by means of pouring, coating, printing, etc. Moreover, when using the coating and printing methods, a multi-layer first mixture, that is, a multi-layer composite material, can be formed on the surface of the weather-resistant layer 11.

[0076] The device for attaching the first mixture to the surface of the weather-resistant layer 11 is a coating mold A. As Figure 3As shown, the coating mold A is formed by detachably enclosing multiple side walls A01. The shape enclosed by the coating mold A is the same as the shape of the weather-resistant layer 11, and the size of the coating mold A matches the size of the weather-resistant layer 11. At this time, the coating mold A can not only fix the weather-resistant layer 11, but also limit the flow range of the first mixture, preventing the first mixture from exceeding the surface range of the weather-resistant layer 11, thereby improving work efficiency.

[0077] Exemplarily, as Figure 3 shown, when the shape of the weather-resistant layer 11 is rectangular, the coating mold A can be formed by detachably enclosing four side walls A01 into a rectangular frame. Moreover, the rectangular frame is slightly larger than the size of the weather-resistant layer 11 to facilitate placing the weather-resistant layer 11 into the rectangular frame.

[0078] During use, place the weather-resistant layer 11 into the coating mold A in a flat-laying manner, then pour the first mixture onto the surface of the weather-resistant layer 11 to evenly cover the surface of the weather-resistant layer 11. After the first mixture is crosslinked to form the impact-resistant layer 12, remove the coating mold A.

[0079] Step S400: Treat the prefabricated cover plate at the first temperature to carry out the first crosslinking reaction.

[0080] Step S500: Treat the prefabricated cover plate at the second temperature to carry out the second crosslinking reaction to obtain the encapsulated cover plate; wherein, the first temperature is lower than the second temperature. In practical applications, first set the temperature at the first temperature and use this temperature to make the first mixture carry out the first crosslinking reaction. Then raise the temperature to the second temperature and use the second temperature to make the first mixture further complete the second crosslinking reaction to form the impact-resistant layer 12.

[0081] Specifically, there are various ways to carry out the first crosslinking reaction and the second crosslinking reaction. For example: the first crosslinking reaction is a crosslinking reaction of flexible components, the first temperature is 40°C to 50°C, and the time for treating the prefabricated cover plate at the first temperature is 10 min to 60 min. The second crosslinking reaction is a crosslinking reaction of rigid components, the second temperature is 80°C to 100°C; the time for treating the prefabricated cover plate at the second temperature is 10 min to 60 min. At this time, the crosslinking reaction of flexible components and the crosslinking reaction of rigid components are carried out step by step. The network structure formed by the first crosslinking reaction can play a role in dispersing and fixing the uncrosslinked materials, so that the components in the composite material can be evenly dispersed, improving the performance stability of the impact-resistant layer 12. Moreover, the first temperature is lower than the second temperature, which can prevent the second crosslinking reaction from occurring prematurely.

[0082] Exemplarily, the first temperature can be 40°C, 42°C, 43°C, 44°C, 45°C, 46°C, 47°C, 48°C, 49°C, 50°C, etc. The second temperature can be 80°C, 82°C, 85°C, 88°C, 90°C, 91°C, 93°C, 96°C, 97°C, 99°C, 100°C, etc. The time for treating the precast cover plate at the first temperature and the second temperature can both be 10 min, 15 min, 20 min, 30 min, 40 min, 50 min, 60 min, etc.

[0083] For another example, the first cross-linking reaction includes a flexible component cross-linking reaction and a rigid cross-linking reaction, but the curing is incomplete. The second cross-linking reaction completely cures the first mixture at a high temperature to form the impact-resistant layer 12. In this way, the first temperature can be 20°C to 30°C. For example, the first temperature can be 20°C, 22°C, 25°C, 27°C, 29°C, 30°C, etc. The second temperature can be 120°C to 160°C. For example, the second temperature can be 120°C, 130°C, 135°C, 140°C, 150°C, 155°C, 160°C, etc. At this time, first make the first mixture undergo the first cross-linking reaction in a room temperature environment, which also completes most of the cross-linking and curing of the impact-resistant layer 12. Then use a higher temperature to completely cure the first mixture to form the impact-resistant layer 12. When adopting this method, the second cross-linking reaction can be completed in the lamination process of the photovoltaic module. At this time, the process steps can be saved, the production efficiency can be improved, and the energy consumption generated by heating can be reduced, saving resources.

[0084] When manufacturing the encapsulation cover plate by the above method, through two steps of the first cross-linking reaction and the second cross-linking reaction to make the interpenetrating network structure of the composite material, the mutual influence between the two network structures can be reduced, phase separation can be reduced, and the performance of the impact-resistant layer 12 can be improved. Moreover, the weather-resistant layer 11 is made of materials such as PET, and compared with the fiber cloth, the position fluctuation in the encapsulation material is smaller, making the encapsulation cover plate more stable. In addition, for the manufacturing method of the encapsulation cover plate of the present invention, only the first mixture needs to be attached to the surface of the weather-resistant layer 11 and two different temperature treatments are required, the process is simple, and the manufacturing difficulty is low, so that the production cost can be reduced and the manufacturing efficiency can be improved.

[0085] An embodiment of the present invention further provides a photovoltaic module. This photovoltaic module includes the above-mentioned encapsulation cover plate. Exemplarily, as Figure 4 shown, the photovoltaic module specifically includes a front encapsulation cover plate 21, a first encapsulation adhesive film 22, a solar cell module 23, a second encapsulation adhesive film 24, and a rear encapsulation cover plate 25.

[0086] The front encapsulation cover plate 21 adopts the above-mentioned encapsulation cover plate provided by the embodiment of the present invention. Both the first encapsulation film 22 and the second encapsulation film 24 are any one of EVA, POE, PVB, PDMS or ionomer. The light transmittance of both the first encapsulation film 22 and the second encapsulation film 24 is greater than or equal to 90%. The grammage of both the first encapsulation film 22 and the second encapsulation film 24 is greater than or equal to 360 g / m 2 . The photovoltaic cells included in the solar cell module 23 can be bifacial power generation cells. Specifically, the cells can be 1 / N cells after cutting, where N≥2. The cells are connected into a cell string through interconnection bars. The cell string contains at least 2 cells, and the spacing between the cells can be 1 mm to 5 mm. The cell strings are connected by busbars to form a solar cell module 23 according to certain circuit requirements. A solar cell module 23 contains at least 2 cell strings, and the spacing between the cell strings ≥0.5 mm. The rear encapsulation cover plate 25 can be a conventional solar backsheet for photovoltaic modules, such as any one of TPT, TPO, TPC, KPE, KPC, KPO. Of course, the rear encapsulation cover plate 25 can also be the above-mentioned encapsulation cover plate provided by the embodiment of the present invention.

[0087] After stacking the front encapsulation cover plate 21, the first encapsulation film 22, the solar cell module 23, the second encapsulation film 24 and the rear encapsulation cover plate 25 in sequence, a photovoltaic module product can be obtained through press lamination.

[0088] Although the present invention has been described in connection with various embodiments herein, however, in the process of implementing the claimed invention, those skilled in the art can understand and achieve other variations of the disclosed embodiments by viewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "one" does not exclude a plurality. Certain measures are recited in mutually different dependent claims, but this does not mean that these measures cannot be combined to produce good results.

[0089] Although the present invention has been described in connection with specific features and their embodiments, it is obvious that various modifications and combinations can be made without departing from the spirit and scope of the present invention. Accordingly, this specification and the drawings are merely exemplary illustrations of the invention defined by the appended claims, and are considered to cover any and all modifications, variations, combinations or equivalents within the scope of the present invention. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. An encapsulation cover plate, characterized in that, applied to a photovoltaic module, the encapsulation cover plate includes a weather-resistant layer and an impact-resistant layer attached to the weather-resistant layer; the material of the impact-resistant layer is a composite material with an interpenetrating network structure, the composite material includes a flexible component and a rigid component, and the flexible component and the rigid component are intertwined into an interpenetrating network structure; the interpenetrating network structure is formed by at least two crosslinked networks interpenetrating each other; the interpenetrating network structure of the composite material is fabricated in two steps through a first crosslinking reaction and a second crosslinking reaction, the first crosslinking reaction is a flexible component crosslinking reaction, the second crosslinking reaction is a rigid component crosslinking reaction, and the flexible component crosslinking reaction and the rigid component crosslinking reaction are carried out step by step; the flexible component includes polyurethane or polyorganosiloxane, and the rigid component includes acrylate.

2. The encapsulation cover plate according to claim 1, characterized in that, the mass ratio of the flexible component to the rigid component is 1:(1~2).

3. The encapsulation cover plate according to claim 1, characterized in that, the polyurethane includes at least one of ester-type polyurethane and ether-type polyurethane.

4. The encapsulation cover plate according to any one of claims 1 to 3, characterized in that, the composite material further includes a reinforcing material, and the mass of the reinforcing material is 1 / 3 times to 2 / 3 times the sum of the masses of the flexible component and the rigid component; the reinforcing material is 0-dimensional, 1-dimensional, 2-dimensional or 3-dimensional; the reinforcing material is a transparent material or a colored material.

5. The encapsulation cover plate according to claim 4, characterized in that, the reinforcing material includes one or more of glass microspheres, glass fibers, and polymer fiber materials.

6. The encapsulation cover plate according to any one of claims 1 to 3, characterized in that, the material of the weather-resistant layer is one or more of ETFE, ECTFE, PVDF, PVF, FEP, PET or PC; and / or, the thickness of the weather-resistant layer is 20μm to 500μm; and / or, the light transmittance of the weather-resistant layer is greater than or equal to 90%; and / or, the impact-resistant layer is transparent.

7. The encapsulation cover plate according to any one of claims 1 to 3, characterized in that, the encapsulation cover plate serves as the front encapsulation cover plate or the rear encapsulation cover plate of the photovoltaic module.

8. A manufacturing method of the encapsulation cover plate according to any one of claims 1 to 7, characterized in that, includes the following steps: providing a first mixture, the first mixture is formed by mixing reactants of the flexible component, a flexible component crosslinking catalyst, monomers of the rigid component, a rigid component crosslinking initiator, and a reinforcing material; providing a weather-resistant layer; attaching the first mixture to the surface of the weather-resistant layer to obtain a prefabricated cover plate; treating the prefabricated cover plate at a first temperature to carry out a first crosslinking reaction; treating the prefabricated cover plate at a second temperature to carry out a second crosslinking reaction to obtain an encapsulation cover plate; wherein, the first temperature is less than the second temperature; the first crosslinking reaction is a flexible component crosslinking reaction; the second crosslinking reaction is a rigid component crosslinking reaction; the flexible component crosslinking reaction and the rigid component crosslinking reaction are carried out step by step.

9. The manufacturing method of the encapsulation cover plate according to claim 8, characterized in that, the surface energy of the weather-resistant layer is greater than or equal to 38 dynes.

10. The manufacturing method of the encapsulation cover plate according to claim 8, characterized in that, providing a weather-resistant layer includes: surface-treating the weather-resistant layer; the surface treatment includes at least one of corona treatment, plasma treatment, and flame treatment.

11. The manufacturing method of the encapsulation cover plate according to claim 8, characterized in that, the reactants of the flexible component include polyether polyol, small molecule polyol, and hexamethylene diisocyanate; the crosslinking catalyst of the flexible component is an organotin catalyst; the monomers of the rigid component include one or more of methyl acrylate, ethyl acrylate, n-butyl acrylate, methyl methacrylate, n-butyl methacrylate, and acrylic acid-modified bisphenol A epoxy resin; the crosslinking initiator of the rigid component is a peroxide initiator or an azo initiator, wherein the azo initiator includes one or more of azodiisobutyronitrile, azodiisovaleronitrile, and azodiisoheptonitrile.

12. The manufacturing method of the encapsulation cover plate according to claim 11, characterized in that, providing a first mixture includes: mixing polyether polyol and small molecule polyol at 50°C to 70°C; adding hexamethylene diisocyanate after cooling to obtain a second mixture; mixing the monomers of the rigid component, the crosslinking initiator of the rigid component, and the crosslinking catalyst of the flexible component to obtain a third mixture; adding the reinforcing material to the second mixture first, and then adding the third mixture to obtain the first mixture.

13. The manufacturing method of the encapsulation cover plate according to any one of claims 8 to 12, characterized in that, the method of attaching the first mixture to the surface of the weather-resistant layer is: pouring, coating, or printing.

14. The manufacturing method of the encapsulation cover plate according to any one of claims 8 to 12, characterized in that, the device for attaching the first mixture to the surface of the weather-resistant layer is a coating mold; the coating mold is formed by detachably surrounding multiple side walls, the shape surrounded by the coating mold is the same as the shape of the weather-resistant layer, and the size of the coating mold matches the size of the weather-resistant layer.

15. The manufacturing method of the encapsulation cover plate according to any one of claims 8 to 12, characterized in that, the first temperature is 40°C to 50°C, and the time for treating the prefabricated cover plate at the first temperature is 10 min to 60 min; the second temperature is 80°C to 100°C; the time for treating the prefabricated cover plate at the second temperature is 10 min to 60 min; alternatively, the first temperature is 20°C to 30°C, and the second temperature is 120°C to 160°C.

16. The manufacturing method of the encapsulation cover plate according to any one of claims 8 to 12, characterized in that, the second crosslinking reaction is completed in the lamination process of the photovoltaic module.

17. A photovoltaic module, characterized in that, it includes the encapsulation cover plate according to any one of claims 1 to 7.

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