Fluoride-free back plate for photovoltaic module, preparation method of fluoride-free back plate and photovoltaic module

Abstract

The invention relates to a fluoride-free backboard for a photovoltaic module, a preparation method of the fluoride-free backboard and the photovoltaic module. The fluoride-free backboard for the photovoltaic module comprises a polyurethane bonding layer, a reflecting layer, a first heat dissipation layer, a supporting layer and a second heat dissipation layer which are arranged in a stacked mode. The reflecting layer is prepared from, by mass, 40-60 parts of acrylic resin, 2-10 parts of isocyanate, 2-10 parts of a first silane coupling agent, 1-10 parts of polyacrylamide, 1-10 parts of a first stabilizer, 5-20 parts of silicon dioxide, 1-10 parts of carbon black and 1-10 parts of chromic oxide. According to the fluoride-free backboard for the photovoltaic module, the reflectivity of the fluoride-free backboard for the photovoltaic module to light can be effectively improved, the conduction and heat dissipation capability of the fluoride-free backboard for the photovoltaic module is improved, the temperature of the module is reduced, and the power generation power of the module is increased. Meanwhile, the fluoride-free backboard for the photovoltaic module reflects the light into the air, so that the weather resistance of the fluoride-free backboard for the photovoltaic module can be effectively improved, and the service life of the photovoltaic module is prolonged.

Description

Technical Field

[0001] The present application relates to the photovoltaic field, and in particular to a fluorine-free backsheet for a photovoltaic module, a preparation method thereof, and a photovoltaic module. Background Art

[0002] Solar energy technology is an important branch of renewable energy and has broad application prospects. Photovoltaic power generation converts solar radiation into electrical energy through the photovoltaic effect. It is a green energy source. The current main research and development direction is to improve the conversion efficiency of photovoltaic cells, reduce costs, and improve the stability and flexibility of solar energy utilization. With the improvement of the photoelectric conversion efficiency of photovoltaic cells, the problem of component heating has also become prominent. For every 1°C increase in temperature, the power output will decrease by 0.4%~0.5%. For some high-power cells, the hot spot temperature can even reach 200°C. The main solution involves conducting the temperature of the component to the air side through the photovoltaic backplane to reduce the temperature of the component. At present, photovoltaic backplanes are divided into fluorine-containing backplanes and fluorine-free backplanes according to their structure. Fluorine-containing backplanes have problems such as difficulty in recycling fluorine-containing materials and high prices, while traditional fluorine-free backplanes have poor thermal conductivity, which affects the power output of photovoltaic modules.

[0003] Therefore, it is necessary to improve the traditional technology. Summary of the invention

[0004] Based on this, the present application provides a fluorine-free backsheet for a photovoltaic module with good thermal conductivity, a preparation method thereof, and a photovoltaic module.

[0005] The technical solution of this application to solve the above technical problems is as follows.

[0006] The first aspect of the present application provides a fluorine-free backsheet for a photovoltaic module, comprising a stacked polyurethane adhesive layer, a reflective layer, a first heat dissipation layer, a support layer and a second heat dissipation layer; the raw materials for preparing the reflective layer include the following components in parts by mass: 40 to 60 parts of acrylic resin, 2 to 10 parts of isocyanate, 2 to 10 parts of a first silane coupling agent, 1 to 10 parts of polyacrylamide, 1 to 10 parts of a first stabilizer, 5 to 20 parts of silicon dioxide, 1 to 10 parts of carbon black and 1 to 10 parts of chromium oxide.

[0007] In some of the embodiments, in the fluorine-free backsheet for photovoltaic modules, the raw materials for preparing the reflective layer include the following components, measured by weight: 45-60 parts of acrylic resin, 2-6 parts of isocyanate, 3-8 parts of a first silane coupling agent, 1-5 parts of polyacrylamide, 1-5 parts of a first stabilizer, 5-10 parts of silicon dioxide, 1-5 parts of carbon black and 1-5 parts of chromium oxide.

[0008] In some of the embodiments, in the fluorine-free backsheet for photovoltaic modules, the mass ratio of the carbon black to the silicon dioxide is 0.2-0.8:1.

[0009] In some of the embodiments, in the fluorine-free backsheet for photovoltaic modules, the raw materials for preparing the first heat dissipation layer and the second heat dissipation layer independently include the following components, measured by weight: 55-60 parts of acrylic resin, 2-6 parts of isocyanate, 5-10 parts of a second silane coupling agent, 1-5 parts of polyacrylamide, 1-5 parts of a second stabilizer, 2-8 parts of silicon dioxide, 1-5 parts of copper powder, 1-5 parts of aluminum oxide and 1-5 parts of boron nitride.

[0010] In some of the embodiments, in the fluorine-free backsheet for photovoltaic modules, the mass ratio of the boron nitride to the silicon dioxide is 0.5-2:1.

[0011] In some of the embodiments, in the fluorine-free backsheet for photovoltaic modules, the raw materials for preparing the polyurethane adhesive layer include the following components, measured by weight: 55-75 parts of acrylic resin, 3-8 parts of isocyanate, 1-5 parts of a third silane coupling agent, 1-5 parts of polyacrylamide, 2-7 parts of silicon dioxide and 1-5 parts of titanium dioxide.

[0012] In some embodiments, in the fluorine-free backsheet for photovoltaic modules, the support layer includes PET.

[0013] In some embodiments, the fluorine-free backsheet for photovoltaic modules satisfies at least one of the following characteristics:

[0014] (1) The thickness of the polyurethane adhesive layer is 2 μm to 5 μm;

[0015] (2) The thickness of the poly-reflective layer is 1 μm to 3 μm;

[0016] (3) The thickness of the first heat dissipation layer is 3 μm to 7 μm;

[0017] (4) The thickness of the second heat dissipation layer is 6 μm to 10 μm.

[0018] In some of the embodiments, in the fluorine-free backsheet for photovoltaic modules, the fluorine-free backsheet for photovoltaic modules also includes a protective layer, and the protective layer is arranged on the surface of the second heat dissipation layer away from the supporting layer. The raw materials for preparing the protective layer include the following components by mass: 60-80 parts of acrylic resin, 5-10 parts of isocyanate, 5-10 parts of fourth silane coupling agent, 1-5 parts of polyacrylamide, 2-7 parts of silicon dioxide, 1-5 parts of zirconium dioxide and 1-5 parts of titanium dioxide.

[0019] In some of the embodiments, in the fluorine-free backsheet for photovoltaic modules, the thickness of the protective layer is 8 μm to 15 μm.

[0020] The second aspect of the present application provides a method for preparing a fluorine-free backsheet for a photovoltaic module, comprising the following steps:

[0021] Prepare a first heat dissipation layer on a surface of the support layer;

[0022] Mix 40-60 parts of acrylic resin, 2-10 parts of isocyanate, 2-10 parts of first silane coupling agent, 1-10 parts of polyacrylamide, 1-10 parts of first stabilizer, 5-20 parts of silicon dioxide, 1-10 parts of carbon black, 1-10 parts of chromium oxide and 40-50 parts of solvent by weight to prepare a reflective slurry;

[0023] The reflective slurry is disposed on the surface of the first heat dissipation layer away from the support layer, and is cured to prepare a reflective layer;

[0024] Preparing a polyurethane adhesive layer on a surface of the reflective layer away from the first heat dissipation layer;

[0025] A second heat dissipation layer is prepared on a surface of the support layer away from the first heat dissipation layer.

[0026] A third aspect of the present application provides a photovoltaic module, comprising a photovoltaic cell and the above-mentioned fluorine-free backboard for photovoltaic modules or the fluorine-free backboard for photovoltaic modules prepared by the above-mentioned preparation method, wherein the photovoltaic cell is arranged on the surface of the polyurethane adhesive layer away from the reflective layer.

[0027] Compared with the prior art, the fluorine-free backsheet for photovoltaic modules of the present application has the following beneficial effects:

[0028] The fluorine-free backboard for photovoltaic modules of the present application comprises a polyurethane adhesive layer, a reflective layer, a first heat dissipation layer, a support layer and a second heat dissipation layer arranged in a stacked manner, wherein the reflective layer is prepared using specific raw materials, and acrylic resin is used as the main body, and on the basis of reacting with isocyanate to form a polyurethane resin, silicon dioxide, carbon black and chromium oxide are matched with it in a specific proportion, and under the action of specific polyacrylamide and silane coupling agent, the reflectivity of the fluorine-free backboard for photovoltaic modules to light can be effectively improved, and the heat dissipation layer on both sides of the support layer can be used to effectively improve the conduction and heat dissipation capacity of the fluorine-free backboard for photovoltaic modules, reduce the module temperature, and increase the module power generation. At the same time, the fluorine-free backboard for photovoltaic modules of the present application reflects light into the air, which can effectively improve the weather resistance of the fluorine-free backboard for photovoltaic modules and extend the service life of photovoltaic modules. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 Schematic diagram of the structure of the fluorine-free backsheet for photovoltaic modules provided in some examples.

[0031] Reference numerals:

[0032] 100: fluorine-free back sheet for photovoltaic module; 110: support layer; 120: first heat dissipation layer; 130: reflection layer; 140: polyurethane adhesive layer; 150: second heat dissipation layer; 160: protective layer. DETAILED DESCRIPTION

[0033] References to embodiments of the present invention will now be provided in detail, one or more examples of which are described below. Each example is provided as an explanation rather than a limitation of the present invention. In fact, it will be apparent to those skilled in the art that various modifications and variations may be made to the present invention without departing from the scope or spirit of the present invention. For example, a feature illustrated or described as part of one embodiment may be used in another embodiment to produce a further embodiment.

[0034] Therefore, it is intended that the present invention covers such modifications and variations that fall within the scope of the appended claims and their equivalents. Other objects, features and aspects of the present invention are disclosed in or are obvious from the following detailed description. Those of ordinary skill in the art will appreciate that this discussion is only a description of exemplary embodiments and is not intended to limit the broader aspects of the present invention.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0036] The term "comprises", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of more restrictions, the elements defined by the sentence "comprising one..." do not exclude the presence of other identical elements in the process, method, article or equipment including the elements. The indefinite articles "a kind of" and "an" before the elements or components of the present invention are not restrictive to the quantity requirements (i.e., the number of occurrences) of the elements or components. Therefore, "a" or "a kind of" should be interpreted as including one or at least one, and the elements or components in the singular form also include the plural form, unless the number clearly refers only to the singular form. The meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0037] The weight of the relevant components mentioned in the description of the embodiments of the present invention may not only refer to the specific content of each component, but also indicate the weight ratio between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the description of the embodiments of the present invention, it is within the scope disclosed in the description of the embodiments of the present invention. Specifically, the weight described in the description of the embodiments of the present invention may be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0038] Except as shown in the operating examples or otherwise indicated, all numbers used in the specification and claims to indicate the amount of ingredients, physicochemical properties, etc. are understood to be adjusted by the term "about" in all cases. For example, therefore, unless otherwise indicated, the numerical parameters listed in the above specification and the attached claims are approximate values, and those skilled in the art can use the teachings disclosed herein to seek to obtain the desired properties and appropriately change these approximate values. The use of numerical ranges expressed as endpoints includes all numbers within the range and any range within the range, for example, 1 to 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4 and 5, etc.

[0039] Traditional photovoltaic glass and photovoltaic backplanes have high thermal resistance and low thermal conductivity, and are unable to dissipate heat in a timely manner, thus affecting the photoelectric conversion efficiency of the components.

[0040] An embodiment of the present application provides a fluorine-free backsheet for a photovoltaic module, comprising a polyurethane adhesive layer, a reflective layer, a first heat dissipation layer, a support layer and a second heat dissipation layer which are stacked; the raw materials for preparing the reflective layer include the following components in parts by mass: 40 to 60 parts of acrylic resin, 2 to 10 parts of isocyanate, 2 to 10 parts of a first silane coupling agent, 1 to 10 parts of polyacrylamide, 1 to 10 parts of a first stabilizer, 5 to 20 parts of silicon dioxide, 1 to 10 parts of carbon black and 1 to 10 parts of chromium oxide.

[0041] The fluorine-free backboard for photovoltaic modules of the present application comprises a polyurethane adhesive layer, a reflective layer, a first heat dissipation layer, a support layer and a second heat dissipation layer arranged in a stacked manner, wherein the reflective layer is prepared using specific raw materials, and acrylic resin is used as the main body, and on the basis of reacting with isocyanate to form a polyurethane resin, silicon dioxide, carbon black and chromium oxide are matched with it in a specific proportion, and under the action of specific polyacrylamide and silane coupling agent, the reflectivity of the fluorine-free backboard for photovoltaic modules to light can be effectively improved, and the heat dissipation layer on both sides of the support layer can be used to effectively improve the conduction and heat dissipation capacity of the fluorine-free backboard for photovoltaic modules, reduce the module temperature, and increase the module power generation. At the same time, the fluorine-free backboard for photovoltaic modules of the present application reflects light into the air, which can effectively improve the weather resistance of the fluorine-free backboard for photovoltaic modules and extend the service life of photovoltaic modules.

[0042] By combining silicon dioxide, carbon black and chromium oxide in a specific proportion, the reflectivity can reach about 0.95, which can reflect light into the air, reduce photon heat, and reflect it onto the battery cell to improve light utilization.

[0043] It can be understood that in the preparation of the reflective layer, the raw materials include, by weight: acrylic resin includes but is not limited to 40 parts, 42 parts, 45 parts, 48 ​​parts, 50 parts, 52 parts, 55 parts, 58 parts, 60 parts; isocyanate includes but is not limited to 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts; the first silane coupling agent includes but is not limited to 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts; polyacrylamide includes but is not limited to 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts , 8, 9, 10 parts; the first stabilizer includes but is not limited to 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts; silicon dioxide includes but is not limited to 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 12 parts, 15 parts, 18 parts, 20 parts; carbon black includes but is not limited to 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts; chromium oxide includes but is not limited to 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts. In some examples, any two of these point values ​​can be used as end values ​​within the range, the same below.

[0044] In some of the examples, in the fluorine-free backsheet for photovoltaic modules, the raw materials for preparing the reflective layer include the following components: 45-60 parts of acrylic resin, 2-6 parts of isocyanate, 3-8 parts of a first silane coupling agent, 1-5 parts of polyacrylamide, 1-5 parts of a first stabilizer, 5-10 parts of silicon dioxide, 1-5 parts of carbon black and 1-5 parts of chromium oxide.

[0045] In some of the examples, in the fluorine-free backsheet for photovoltaic modules, the raw materials for preparing the reflective layer include the following components: 50-55 parts of acrylic resin, 3-5 parts of isocyanate, 4-6 parts of a first silane coupling agent, 2-4 parts of polyacrylamide, 2-4 parts of a first stabilizer, 6-8 parts of silica, 2-4 parts of carbon black and 2-4 parts of chromium oxide.

[0046] In some of these examples, the mass ratio of carbon black to silica in the fluorine-free backsheet for photovoltaic modules is 0.2~0.8:1.

[0047] It is understood that the mass ratio of carbon black to silica includes but is not limited to 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, and 0.8:1.

[0048] Optionally, the mass ratio of carbon black to silicon dioxide is 0.3~0.4:1.

[0049] In some of the examples, in the fluorine-free backsheet for photovoltaic modules, the raw materials for preparing the first heat dissipation layer and the second heat dissipation layer independently include the following components, measured by mass: 55-60 parts of acrylic resin, 2-6 parts of isocyanate, 5-10 parts of a second silane coupling agent, 1-5 parts of polyacrylamide, 1-5 parts of a di-stabilizer, 2-8 parts of silicon dioxide, 1-5 parts of copper powder, 1-5 parts of aluminum oxide and 1-5 parts of boron nitride.

[0050] It can be understood that the raw materials for preparing the first heat dissipation layer and the second heat dissipation layer can be the same or different; it can also be understood that among the raw materials for preparing the first heat dissipation layer and the second heat dissipation layer, by weight: acrylic resin includes but is not limited to 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, and 60 parts; isocyanate includes but is not limited to 2 parts, 3 parts, 4 parts, 5 parts, and 6 parts; the second silane coupling agent includes but is not limited to 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, and 10 parts; polyacrylamide includes but is not limited to 1 part, 2 parts, 3 parts, 4 parts, and 5 parts; the second stabilizer includes but is not limited to 1 part, 2 parts, 3 parts, 4 parts, and 5 parts; silicon dioxide includes but is not limited to 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, and 8 parts; copper powder includes but is not limited to 1 part, 2 parts, 3 parts, 4 parts, and 5 parts; aluminum oxide includes but is not limited to 1 part, 2 parts, 3 parts, 4 parts, and 5 parts; boron nitride includes but is not limited to 1 part, 2 parts, 3 parts, 4 parts, and 5 parts.

[0051] In some of the examples, in the fluorine-free backsheet for photovoltaic modules, the raw materials for preparing the first heat dissipation layer and the second heat dissipation layer independently include the following components, measured by mass: 56-58 parts of acrylic resin, 3-5 parts of isocyanate, 6-8 parts of a third silane coupling agent, 2-4 parts of polyacrylamide, 2-4 parts of a second stabilizer, 3-6 parts of silicon dioxide, 2-4 parts of copper powder, 2-4 parts of aluminum oxide and 2-4 parts of boron nitride.

[0052] The thermal conductive network composed of copper powder, boron nitride and aluminum oxide can fully conduct heat out of the component, increase the heat dissipation of the battery cell, reduce the power generation temperature of the component, increase the power generation capacity of the component, and extend the life of the component.

[0053] In some of these examples, the mass ratio of boron nitride to silicon dioxide in the fluorine-free backsheet for photovoltaic modules is 0.5~2:1.

[0054] It will be appreciated that the mass ratio of boron nitride to silicon dioxide includes, but is not limited to, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 1:1, 1.2:1, 1.3:1, 1.4:1, 1.5:1, 1.6:1, 1.7:1, 1.8:1, and 2:1.

[0055] Optionally, in the fluorine-free backsheet for photovoltaic modules, the mass ratio of boron nitride to silicon dioxide is 0.5~1:1.

[0056] In some of the examples, in the fluorine-free backsheet for photovoltaic modules, the raw materials for preparing the polyurethane adhesive layer include the following components: 55-75 parts of acrylic resin, 3-8 parts of isocyanate, 1-5 parts of a third silane coupling agent, 1-5 parts of polyacrylamide, 2-7 parts of silicon dioxide and 1-5 parts of titanium dioxide.

[0057] It can be understood that among the raw materials for preparing the polyurethane adhesive layer, by mass percentage: acrylic resin includes but is not limited to 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, 62 parts, 65 parts, 68 parts, 70 parts, 72 parts, and 75 parts; isocyanate includes but is not limited to 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, and 8 parts; the third silane coupling agent includes but is not limited to 1 part, 2 parts, 3 parts, 4 parts, and 5 parts; polyacrylamide includes but is not limited to 1 part, 2 parts, 3 parts, 4 parts, and 5 parts; silicon dioxide includes but is not limited to 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, and 7 parts; titanium dioxide includes but is not limited to 1 part, 2 parts, 3 parts, 4 parts, and 5 parts.

[0058] In some of the examples, in the fluorine-free backsheet for photovoltaic modules, the raw materials for preparing the polyurethane adhesive layer include the following components: 60-70 parts of acrylic resin, 4-6 parts of isocyanate, 2-4 parts of a third silane coupling agent, 2-4 parts of polyacrylamide, 3-6 parts of silicon dioxide and 2-4 parts of titanium dioxide.

[0059] In some of these examples, the support layer in the fluorine-free backsheet for photovoltaic modules includes PET (polyethylene terephthalate).

[0060] PET is translucent and has good thermal conductivity.

[0061] In some of the examples, the fluorine-free backsheet for photovoltaic modules also includes a protective layer, which is arranged on the surface of the second heat dissipation layer away from the supporting layer. The raw materials for preparing the protective layer include the following components by mass: 60-80 parts of acrylic resin, 5-10 parts of isocyanate, 5-10 parts of the fourth silane coupling agent, 1-5 parts of polyacrylamide, 2-7 parts of silicon dioxide, 1-5 parts of zirconium dioxide and 1-5 parts of titanium dioxide.

[0062] It can be understood that among the raw materials for preparing the protective layer, by weight: acrylic resin includes but is not limited to 60-80 parts, isocyanate includes but is not limited to 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts; the fourth silane coupling agent includes but is not limited to 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts; polyacrylamide includes but is not limited to 1 part, 2 parts, 3 parts, 4 parts, 5 parts; silicon dioxide includes but is not limited to 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts; zirconium dioxide includes but is not limited to 1 part, 2 parts, 3 parts, 4 parts, 5 parts; titanium dioxide includes but is not limited to 1 part, 2 parts, 3 parts, 4 parts, 5 parts.

[0063] In some of the examples, in the fluorine-free backsheet for photovoltaic modules, the raw materials for preparing the protective layer include the following components, calculated by weight: 70-75 parts of acrylic resin, 6-8 parts of isocyanate, 6-8 parts of fourth silane coupling agent, 2-4 parts of polyacrylamide, 3-6 parts of silicon dioxide, 2-4 parts of zirconium dioxide and 2-4 parts of titanium dioxide.

[0064] Silicon oxide, zirconium oxide and titanium dioxide are mixed in specific proportions and combined with polyurethane to form a highly weather-resistant protective coating to protect components from corrosion.

[0065] In some of the examples, in the fluorine-free backsheet for photovoltaic modules, the first stabilizer and the second stabilizer independently include at least one of catechol and tert-butylphenol.

[0066] In some of the examples, in the fluorine-free backsheet for photovoltaic modules, the first silane coupling agent, the second silane coupling agent, the third silane coupling agent and the fourth silane coupling agent independently include at least one of vinyltriethoxysilane, vinyltri(β-methoxyethoxy)silane and vinyltrimethoxysilane.

[0067] In some of these examples, the thickness of the polyurethane adhesive layer in the fluorine-free backsheet for photovoltaic modules is 2 μm ~5 μm.

[0068] It can be understood that the thickness of the polyurethane adhesive layer includes but is not limited to 2 μm, 3 μm, 4 μm, and 5 μm.

[0069] In some of these examples, the thickness of the poly-reflective layer in the fluorine-free backsheet for photovoltaic modules is 1 μm ~3 μm.

[0070] It can be understood that the thickness of the poly-reflective layer includes but is not limited to 1 μm, 2 μm, and 3 μm.

[0071] In some of these examples, the thickness of the first heat dissipation layer in the fluorine-free backsheet for photovoltaic modules is 3 μm ~7 μm.

[0072] It can be understood that the thickness of the first heat dissipation layer includes but is not limited to 3 μm, 4 μm, 5 μm, 6 μm, and 7 μm.

[0073] In some of these examples, the thickness of the second heat dissipation layer in the fluorine-free backsheet for photovoltaic modules is 6 μm ~10 μm.

[0074] It can be understood that the thickness of the second heat dissipation layer includes but is not limited to 6 μm, 7 μm, 8 μm, 9 μm, and 10 μm.

[0075] In some of these examples, the thickness of the protective layer in the fluorine-free backsheet for photovoltaic modules is 8 μm ~15 μm.

[0076] It can be understood that the thickness of the protective layer includes but is not limited to 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, and 15 μm.

[0077] See also Figure 1 In some examples, the fluorine-free backsheet 100 for photovoltaic modules includes a support layer 110, a first heat dissipation layer 120, a reflective layer 130 and a polyurethane adhesive layer 140 disposed on one side of the support layer 110, and a second heat dissipation layer 150 and a protective layer 160 disposed on the other side of the support layer 110. It can be understood that the first heat dissipation layer 120, the reflective layer 130 and the polyurethane adhesive layer 140 are on the EVA surface of the support layer 110 and belong to the EVA surface coating; the second heat dissipation layer 150 and the protective layer 160 are on the air surface of the support layer 110 and belong to the air surface coating; when used as a photovoltaic backsheet, the photovoltaic cells are disposed on the EVA surface.

[0078] Compared with the traditional CPC type backsheet, the fluorine-free backsheet for photovoltaic modules in this application adopts a high reflective coating and a conductive heat dissipation network, which can effectively improve the reflectivity of the backsheet to light, enhance the conductive heat dissipation capacity of the backsheet, reduce the module temperature, and increase the module power generation. By reflecting infrared light and ultraviolet light into the air, the weather resistance of the backsheet can also be improved to a certain extent, extending the service life of the module.

[0079] An embodiment of the present application provides a method for preparing a fluorine-free backsheet for a photovoltaic module, comprising the following steps:

[0080] Step S10: preparing a first heat dissipation layer on a surface of the support layer.

[0081] In some examples, step S10 includes the following steps:

[0082] Mixing acrylic resin, isocyanate, silane coupling agent, polyacrylamide, a second stabilizer, silicon dioxide, copper powder, aluminum oxide, boron nitride and a first solvent to prepare a first heat dissipation slurry;

[0083] The first heat dissipation slurry is disposed on a surface of the support layer and solidified to form a first heat dissipation layer.

[0084] In some examples, in step S10, the first solvent includes but is not limited to at least one of ethyl acetate, butyl acetate and acetone.

[0085] In some of the examples, in step S10, the curing temperature is 80°C to 140°C, and the curing time is 2 h to 6 h.

[0086] It can be understood that in step S10, the curing temperature includes but is not limited to 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, and 140°C, and the curing time is 2 h, 3 h, 4 h, 5 h, and 6 h.

[0087] Step S20: Mix 40-60 parts of acrylic resin, 2-10 parts of isocyanate, 2-10 parts of silane coupling agent, 1-10 parts of polyacrylamide, 1-10 parts of first stabilizer, 5-20 parts of silica, 1-10 parts of carbon black, 1-10 parts of chromium oxide and 40-50 parts of second solvent by mass to prepare a reflective slurry.

[0088] In some examples, in step S10, the second solvent includes but is not limited to at least one of ethyl acetate and butyl acetate.

[0089] Step S30: applying a reflective slurry on the surface of the first heat dissipation layer away from the support layer, and curing the surface to prepare a reflective layer.

[0090] In some of the examples, in step S30, the curing temperature is 80°C to 140°C, and the curing time is 2 h to 6 h.

[0091] It can be understood that in step S30, the curing temperature includes but is not limited to 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, and 140°C, and the curing time is 2 h, 3 h, 4 h, 5 h, and 6 h.

[0092] Step S40: preparing a polyurethane adhesive layer on the surface of the reflective layer away from the first heat dissipation layer.

[0093] In some examples, step S40 includes the following steps:

[0094] Mixing acrylic resin, isocyanate, silane coupling agent, polyacrylamide, silicon dioxide and titanium dioxide to prepare bonding slurry;

[0095] The bonding slurry is disposed on the surface of the reflective layer away from the first heat dissipation layer, and is cured to prepare a polyurethane bonding layer.

[0096] In some of the examples, in step S40, the curing temperature is 80°C to 140°C, and the curing time is 2 h to 6 h.

[0097] It can be understood that in step S40, the curing temperature includes but is not limited to 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, and 140°C, and the curing time is 2 h, 3 h, 4 h, 5 h, and 6 h.

[0098] In some examples, in step S40, the step of preparing the bonding slurry includes the following steps:

[0099] The silicon dioxide and titanium dioxide are mixed so that the silicon dioxide is coated on the surface of the titanium dioxide to obtain silicon dioxide coated titanium dioxide;

[0100] The silica-coated titanium dioxide is mixed with acrylic resin, isocyanate, silane coupling agent and polyacrylamide.

[0101] In some of the examples, in step S40, silicon dioxide and titanium dioxide are blended using a high speed mixer.

[0102] In some of the examples, in step S40, the blending rate is 5000 r / min to 20000 r / min.

[0103] Step S50: preparing a second heat dissipation layer on a surface of the support layer away from the first heat dissipation layer.

[0104] The preparation method of the fluorine-free backboard for photovoltaic modules of the present application can effectively improve the reflectivity of the fluorine-free backboard for photovoltaic modules to light, and cooperate with the heat dissipation layer on both sides of the support layer to effectively improve the conduction and heat dissipation capacity of the fluorine-free backboard for photovoltaic modules, reduce the module temperature, and increase the power generation of the module. At the same time, the fluorine-free backboard for photovoltaic modules of the present application reflects light into the air, which can effectively improve the weather resistance of the fluorine-free backboard for photovoltaic modules and extend the service life of photovoltaic modules.

[0105] It can be understood that the preparation method of the fluorine-free backsheet for photovoltaic modules provided in the present application can prepare the above-mentioned fluorine-free backsheet for photovoltaic modules, the above-mentioned fluorine-free backsheet for photovoltaic modules can be prepared by the method provided in the present application, and the features of the above-mentioned fluorine-free backsheet for photovoltaic modules and the preparation method of the fluorine-free backsheet for photovoltaic modules provided in the present application can be mutually applicable.

[0106] In some examples, step S50 includes the following steps:

[0107] Mixing acrylic resin, isocyanate, silane coupling agent, polyacrylamide, a second stabilizer, silicon dioxide, copper powder, aluminum oxide, boron nitride and a third solvent to prepare a second heat dissipation slurry;

[0108] The second heat dissipation slurry is disposed on the surface of the support layer away from the first heat dissipation layer, and is solidified to form the second heat dissipation layer.

[0109] In some examples, in step S50, the third solvent includes but is not limited to at least one of ethyl acetate, butyl acetate and acetone.

[0110] In some of the examples, in step S50, the curing temperature is 80°C to 140°C, and the curing time is 2 h to 6 h.

[0111] It can be understood that in step S50, the curing temperature includes but is not limited to 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, and 140°C, and the curing time is 2 h, 3 h, 4 h, 5 h, and 6 h.

[0112] In some of the examples, the method for preparing a fluorine-free backsheet for a photovoltaic module further includes, after step S50, step S60: preparing a protective layer on a surface of the second heat dissipation layer away from the support layer.

[0113] In some examples, step S60 includes the following steps:

[0114] Mixing acrylic resin, isocyanate, silane coupling agent, polyacrylamide, silicon dioxide, zirconium dioxide and titanium dioxide to obtain a protective slurry;

[0115] The protective slurry is disposed on the surface of the second heat dissipation layer away from the support layer, and is solidified to form a protective layer.

[0116] In some of the examples, in step S60, the curing temperature is 80°C to 140°C, and the curing time is 2 h to 6 h.

[0117] It can be understood that in step S60, the curing temperature includes but is not limited to 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, and 140°C, and the curing time is 2 h, 3 h, 4 h, 5 h, and 6 h.

[0118] In some examples, in step S60, the step of preparing the protective slurry includes the following steps:

[0119] Silicon dioxide, zirconium dioxide and titanium dioxide are mixed to coat the surface of titanium dioxide with silicon dioxide and zirconium dioxide, and then the coated titanium dioxide is mixed with acrylic resin, isocyanate, silane coupling agent and polyacrylamide.

[0120] In some of the examples, in step S60, silicon dioxide, zirconium dioxide and titanium dioxide are blended using a high speed mixer.

[0121] In some of the examples, in step S60, the blending rate is 5000 r / min to 20000 r / min.

[0122] One embodiment of the present application provides a photovoltaic module, including a photovoltaic cell and the above-mentioned fluorine-free backboard for photovoltaic modules or the fluorine-free backboard for photovoltaic modules prepared by the above-mentioned preparation method, wherein the photovoltaic cell is arranged on the surface of the polyurethane adhesive layer away from the reflective layer.

[0123] It can be understood that photovoltaic modules can be used in photovoltaic power stations, such as ground power stations, rooftop power stations, water power stations, etc., and can also be used in equipment or devices that use solar energy to generate electricity, such as user solar power supplies, solar street lights, solar cars, solar buildings, etc. It can also be understood that the application scenarios of photovoltaic systems include but are not limited to this, that is, photovoltaic systems can be used in all fields that require solar energy to generate electricity. Taking the photovoltaic power generation system network as an example, the photovoltaic system may include a photovoltaic array, a junction box and an inverter. The photovoltaic array can be an array combination of multiple photovoltaic modules. For example, multiple photovoltaic modules can form multiple photovoltaic arrays. The photovoltaic array is connected to the junction box. The junction box can converge the current generated by the photovoltaic array. The converged current flows through the inverter and is converted into the alternating current required by the mains power grid, and then connected to the mains network to achieve solar power supply.

[0124] The photovoltaic module provided in the present application can be used in, but is not limited to, electrical devices such as vehicles, ships or aircraft.

[0125] The embodiments of the present application provide an electric device, which may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc., and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0126] The present application is further described in detail below in conjunction with specific implementation methods, but the implementation methods of the present application are not limited thereto.

[0127] Example 1

[0128] Preparation of reflective slurry: by weight, 45 parts of acrylic resin, 2 parts of isocyanate, 3 parts of silane coupling agent (vinyl triethoxysilane), 5 parts of polyacrylamide, 5 parts of catechol, 5 parts of silicon dioxide, 1 part of carbon black, 5 parts of chromium oxide and 40 parts of ethyl acetate were mixed to prepare reflective slurry;

[0129] Preparation of heat dissipation slurry: by weight, 55 parts of acrylic resin, 6 parts of isocyanate, 5 parts of silane coupling agent (vinyl triethoxysilane), 5 parts of polyacrylamide, 1 part of catechol, 2 parts of silicon dioxide, 5 parts of copper powder, 1 part of aluminum oxide, 1 part of boron nitride and 40 parts of ethyl acetate are mixed to prepare heat dissipation slurry;

[0130] Preparation of bonding slurry: by weight, 75 parts of acrylic resin, 8 parts of isocyanate, 5 parts of silane coupling agent (vinyl triethoxysilane), 1 part of polyacrylamide, 7 parts of silicon dioxide and 1 part of titanium dioxide; firstly, silicon dioxide and titanium dioxide are blended in a high-speed mixer to obtain silicon dioxide-coated titanium dioxide; then, the titanium dioxide is mixed with other components to prepare bonding slurry;

[0131] Preparation of protective slurry: by weight, 60 parts of acrylic resin, 5 parts of isocyanate, 5 parts of silane coupling agent (vinyl triethoxysilane), 5 parts of polyacrylamide, 7 parts of silicon dioxide, 1 part of zirconium dioxide and 1 part of titanium dioxide; firstly blend silicon dioxide, zirconium dioxide and titanium dioxide in a high-speed mixer, then mix the blended coated titanium dioxide with other components to prepare protective slurry;

[0132] (1) applying the heat dissipation slurry to one side of the PET support layer, drying and curing at 80°C to 120°C, and aging to form a first heat dissipation layer on the surface of the PET support layer with a thickness of 5 μm to 7 μm;

[0133] (2) coating the reflective slurry on the surface of the first heat dissipation layer away from the support layer prepared in step (1), drying and curing at 80° C. to 120° C., and aging to form a reflective layer on the surface of the first heat dissipation layer away from the support layer, with a thickness of 2 μm to 3 μm;

[0134] (3) applying the adhesive slurry to the surface of the reflective layer prepared in step (2) away from the first heat dissipation layer, drying and curing at 80° C. to 120° C., and aging to form a polyurethane adhesive layer on the surface of the reflective layer away from the first heat dissipation layer, with a thickness of 3 μm to 5 μm;

[0135] (4) applying the heat dissipation slurry to the surface of the PET support layer away from the first heat dissipation layer, drying and curing at 80°C to 120°C, and aging to form a second heat dissipation layer on the other surface of the PET support layer with a thickness of 8 μm to 10 μm;

[0136] (5) The protective slurry is applied to the surface of the second heat dissipation layer away from the support layer, dried and cured at 80°C to 120°C, and matured to form a second heat dissipation layer with a thickness of 10 μm to 15 μm on the surface of the second heat dissipation layer away from the support layer, thereby obtaining a fluorine-free backplane.

[0137] Example 2

[0138] It is basically the same as Example 1, except that the proportion of the non-solvent component of the reflective slurry in Example 2 is different, specifically as follows: by mass, 60 parts of acrylic resin, 6 parts of isocyanate, 8 parts of silane coupling agent, 1 part of polyacrylamide, 1 part of catechol, 10 parts of silica, 5 parts of carbon black and 1 part of chromium oxide.

[0139] Example 3

[0140] It is basically the same as Example 1, except that the proportion of the non-solvent component of the reflective slurry in Example 3 is different, specifically as follows: by mass, 50 parts of acrylic resin, 4 parts of isocyanate, 5 parts of silane coupling agent, 3 parts of polyacrylamide, 3 parts of catechol, 8 parts of silica, 3 parts of carbon black and 3 parts of chromium oxide.

[0141] Example 4

[0142] It is basically the same as Example 1, except that the proportion of the non-solvent component of the heat dissipation slurry in Example 4 is different, specifically as follows: by mass, 58 parts of acrylic resin, 4 parts of isocyanate, 8 parts of silane coupling agent, 3 parts of polyacrylamide, 4 parts of catechol, 5 parts of silica, 4 parts of copper powder, 3 parts of aluminum oxide and 4 parts of boron nitride.

[0143] Example 5

[0144] It is basically the same as Example 1, except that the component proportions of the bonding slurry in Example 5 are different, specifically as follows: by mass, 60 parts of acrylic resin, 5 parts of isocyanate, 3 parts of silane coupling agent, 4 parts of polyacrylamide, 5 parts of silicon dioxide and 3 parts of titanium dioxide.

[0145] Example 6

[0146] It is basically the same as Example 1, except that the component proportions of the protective slurry in Example 6 are different, specifically as follows: by mass, 70 parts of acrylic resin, 8 parts of isocyanate, 8 parts of silane coupling agent, 2 parts of polyacrylamide, 3 parts of silicon dioxide, 4 parts of zirconium dioxide and 4 parts of titanium dioxide.

[0147] Comparative Example 1

[0148] It is basically the same as Example 1, except that in the reflective slurry, the carbon black in Example 1 is replaced with an equal mass of silicon carbide.

[0149] Comparative Example 2

[0150] The embodiment is basically the same as the embodiment 1, except that in the reflective slurry, the chromium oxide in the embodiment 1 is replaced by an equal mass of manganese oxide.

[0151] Comparative Example 3

[0152] It is basically the same as Example 1, except that in the reflective slurry, the polyacrylamide in Example 1 is replaced by polyacrylate of the same mass.

[0153] Comparative Example 4

[0154] It is basically the same as Example 1, except that the proportion of the non-solvent component of the reflective slurry in Comparative Example 4 is different, specifically as follows: by mass, 45 parts of acrylic resin, 2 parts of isocyanate, 3 parts of vinyl triethoxy silane, 5 parts of polyacrylamide, 5 parts of catechol, 2 parts of silica, 1 part of carbon black and 15 parts of chromium oxide.

[0155] Comparative Example 5

[0156] The method is basically the same as Example 1, except that step (1) and step (2) are swapped. In Example 5, a reflective layer is first formed on the surface of the PET support layer, and then a first heat dissipation layer is formed on the surface of the reflective layer away from the support layer. Then, a polyurethane adhesive layer is formed on the surface of the first heat dissipation layer away from the reflective layer, and steps (4) to (5) are continued.

[0157] The performance of the fluorine-free backsheets prepared in the embodiments and comparative examples was tested, and the results are shown in Table 1.

[0158] The fluorine-free backsheets prepared in the embodiments and comparative examples were used to support photovoltaic modules. The polyurethane adhesive layer of the fluorine-free backsheet was installed on a module with a power of 550 W. The front and back surface temperatures and output power of the module were tested to comprehensively evaluate the effect of the conductive heat dissipation backsheet. The results are shown in Table 1.

[0159] Table 1

[0160]

[0161] As can be seen from Table 1, compared with the conventional backplane (commercially available CPC structure), the fluorine-free backplane prepared in each embodiment has a lower operating temperature on the front and back sides of the component, and the output power is increased. However, the output power of Comparative Examples 1 to 5 decreases to varying degrees. At the same time, agglomerated particles appear on the back surface of the component in Comparative Example 3. As time goes by, the agglomerated particles will precipitate from the back surface, resulting in poor heat dissipation and affecting the reliability of the component; the ultraviolet resistance of Comparative Example 4 is poor, and the air surface of the backplane slightly turns yellow and discolored during power generation, and the aging resistance deteriorates, affecting the reliability of the component; the polyurethane adhesive layer of Comparative Example 5 delaminates and separates from the adhesive film, and the backplane cannot play a role in protecting the component.

[0162] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0163] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solution of the present application in detail, but it cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the contents of the attached claims, and the description and drawings can be used to explain the contents of the claims.

Claims

1. A fluorine-free back sheet for a photovoltaic module, characterized in that: It comprises a polyurethane adhesive layer, a reflective layer, a first heat dissipation layer, a support layer and a second heat dissipation layer which are stacked; the raw materials for preparing the reflective layer comprise the following components by mass: 40-60 parts of acrylic resin, 2-10 parts of isocyanate, 2-10 parts of a first silane coupling agent, 1-10 parts of polyacrylamide, 1-10 parts of a first stabilizer, 5-20 parts of silicon dioxide, 1-10 parts of carbon black and 1-10 parts of chromium oxide.

2. The fluorine-free back sheet for photovoltaic modules according to claim 1, characterized in that: The raw materials for preparing the reflective layer include the following components in parts by mass: 45-60 parts of acrylic resin, 2-6 parts of isocyanate, 3-8 parts of a first silane coupling agent, 1-5 parts of polyacrylamide, 1-5 parts of a first stabilizer, 5-10 parts of silicon dioxide, 1-5 parts of carbon black and 1-5 parts of chromium oxide.

3. The fluorine-free back sheet for photovoltaic modules according to claim 1, characterized in that: The mass ratio of the carbon black to the silicon dioxide is 0.2-0.8:

1.

4. The fluorine-free back sheet for photovoltaic modules according to any one of claims 1 to 3, characterized in that: In terms of weight percentage, the raw materials for preparing the first heat dissipation layer and the second heat dissipation layer independently include the following components: 55-60 parts of acrylic resin, 2-6 parts of isocyanate, 5-10 parts of a second silane coupling agent, 1-5 parts of polyacrylamide, 1-5 parts of a second stabilizer, 2-8 parts of silicon dioxide, 1-5 parts of copper powder, 1-5 parts of aluminum oxide and 1-5 parts of boron nitride.

5. The fluorine-free back sheet for photovoltaic modules according to claim 4, characterized in that: The mass ratio of the boron nitride to the silicon dioxide is 0.5-2:

1.

6. The fluorine-free back sheet for photovoltaic modules according to any one of claims 1 to 3 and 5, characterized in that: The raw materials for preparing the polyurethane adhesive layer include the following components by mass: 55-75 parts of acrylic resin, 3-8 parts of isocyanate, 1-5 parts of a third silane coupling agent, 1-5 parts of polyacrylamide, 2-7 parts of silicon dioxide and 1-5 parts of titanium dioxide.

7. The fluorine-free back sheet for photovoltaic modules according to any one of claims 1 to 3 and 5, characterized in that: The support layer comprises PET.

8. The fluorine-free back sheet for photovoltaic modules according to any one of claims 1 to 3 and 5, characterized in that: The fluorine-free backsheet for photovoltaic modules meets at least one of the following characteristics: (1) The thickness of the polyurethane adhesive layer is 2 μm to 5 μm; (2) The thickness of the poly-reflective layer is 1 μm to 3 μm; (3) The thickness of the first heat dissipation layer is 3 μm to 7 μm; (4) The thickness of the second heat dissipation layer is 6 μm to 10 μm.

9. The fluorine-free back sheet for photovoltaic modules according to any one of claims 1 to 3 and 5, characterized in that: The fluorine-free backsheet for photovoltaic modules also includes a protective layer, which is arranged on the surface of the second heat dissipation layer away from the support layer. The raw materials for preparing the protective layer include the following components, measured by mass: 60-80 parts of acrylic resin, 5-10 parts of isocyanate, 5-10 parts of a fourth silane coupling agent, 1-5 parts of polyacrylamide, 2-7 parts of silicon dioxide, 1-5 parts of zirconium dioxide and 1-5 parts of titanium dioxide.

10. A method for preparing a fluorine-free back sheet for a photovoltaic module, characterized in that: The following steps are involved: Prepare a first heat dissipation layer on a surface of the support layer; Mix 40-60 parts of acrylic resin, 2-10 parts of isocyanate, 2-10 parts of first silane coupling agent, 1-10 parts of polyacrylamide, 1-10 parts of first stabilizer, 5-20 parts of silicon dioxide, 1-10 parts of carbon black, 1-10 parts of chromium oxide and 40-50 parts of solvent by weight to prepare a reflective slurry; The reflective slurry is disposed on the surface of the first heat dissipation layer away from the support layer, and is cured to prepare a reflective layer; Preparing a polyurethane adhesive layer on a surface of the reflective layer away from the first heat dissipation layer; A second heat dissipation layer is prepared on a surface of the support layer away from the first heat dissipation layer.

11. A photovoltaic module, characterized in that: It comprises a photovoltaic cell and a fluorine-free back sheet for a photovoltaic module as claimed in any one of claims 1 to 9 or a fluorine-free back sheet for a photovoltaic module prepared by the preparation method as claimed in claim 10, wherein the photovoltaic cell is arranged on a surface of the polyurethane adhesive layer away from the reflective layer.

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