Infrared-reflective single-layer black encapsulant film, preparation method thereof and photovoltaic module

Abstract

This application discloses an infrared-reflective single-layer black encapsulating film, its preparation method, and a photovoltaic module, belonging to the field of photovoltaic technology. The infrared-reflective single-layer black encapsulating film of this application includes a resin layer and a composite pigment; the composite pigment is distributed in the resin layer; the composite pigment includes a first pigment and a second pigment; the first pigment is an infrared-reflective pigment, and the second pigment is an infrared-transmitting pigment and / or an infrared-reflective pigment; the Lab chromaticity values ​​of the black film are: L = 11~20, a = -4~4, b = -4~4. The single-layer black film of this application has a reflectivity of >70% in infrared light from 760~1100nm; this single-layer black film has a simple structure, low processing difficulty, and avoids the problems of unstable appearance and easy pigment migration in double-layer structures.

Description

Technical Field

[0001] This application relates to the field of photovoltaic technology, and more specifically, to an infrared reflective single-layer black encapsulating film, its preparation method, and a photovoltaic module. Background Technology

[0002] In recent years, black photovoltaic modules have gradually gained acceptance from users due to their integrated appearance, higher level of sophistication, and more aesthetically pleasing design. With continuous technological advancements, customers are demanding increasingly higher power outputs from modules, thus placing extremely high requirements on the transmittance and even reflectivity of the assembly layers. Traditional black pigments absorb sunlight across a broad spectrum, significantly reducing the module's efficiency in utilizing sunlight. Therefore, the black pigments commonly used in the photovoltaic industry primarily employ two approaches: high transmittance in the infrared band and infrared reflectivity pigments.

[0003] In existing technologies, high-transmittance black pigments in the infrared band are generally used in combination with high-reflectance white pigments, which is also the most popular solution on the market. For example, by setting a black encapsulating film layer (with black-based transparent fillers added inside to ensure color) and a white encapsulating film layer, the reflectivity is improved, thereby improving the power generation efficiency of black photovoltaic modules. However, the two-layer structure increases the processing difficulty on the one hand, and makes the film susceptible to the risk of black and white pigments migrating to each other on the other.

[0004] In existing technologies, infrared reflective black pigments (such as copper chromium black, titanium dioxide, iron chromium black, Black0024, Black0026, CIPigment Black32, and Black10C909) can be used to create black materials with infrared reflective properties on their own. However, due to the limitations of black appearance, the infrared reflectivity of such products is limited to no more than 60%.

[0005] Therefore, there is an irreconcilable contradiction between the black appearance of the photovoltaic module encapsulation film and its high infrared reflectivity. Summary of the Invention

[0006] The main objective of this application is to provide an infrared reflective single-layer black encapsulating film, its preparation method, and a photovoltaic module, so as to solve the problem that existing black encapsulating films are difficult to achieve both a good black appearance and high infrared reflectivity.

[0007] To achieve the above objectives, according to one aspect of this application, an infrared reflective single-layer black encapsulating film is provided, comprising a resin layer and a composite pigment; the composite pigment is distributed in the resin layer.

[0008] The composite pigment includes a first pigment and a second pigment; the first pigment is an infrared reflective pigment, and the second pigment is an infrared transmissive pigment and / or an infrared reflective pigment.

[0009] Lab chromaticity values ​​of infrared reflective single-layer black encapsulating film: L is 11~20, a is -4~4, b is -4~4.

[0010] Furthermore, the reflectance of the first pigment in the 760~1100nm range is >70%.

[0011] Furthermore, the first pigment is at least one of chromium oxide pigments, metal oxide pigments, metal oxide mixed-phase pigments, and ceramic pigments.

[0012] Furthermore, the second pigment is at least one of perylene pigments, quinacridone pigments, pyrrolopyrroledione pigments, indolinone pigments, isoindolinone pigments, and phthalocyanine pigments.

[0013] Furthermore, the weight ratio of the first pigment to the second pigment is (30~60):(40~70).

[0014] Furthermore, the first pigment is selected from at least one of chromium oxide yellow, chromium oxide green, cobalt chromium blue, titanium nickel yellow, bismuth vanadate yellow, antimony tin gray, chromium titanium brown, chromium tin red, cobalt aluminum blue, aluminum oxide, titanium oxide, barium oxide, and zirconium oxide.

[0015] Furthermore, the second pigment is selected from at least one of indololinone yellow, DPP red, perylene red, perylene black, copper phthalocyanine blue, phthalocyanine green, quinacridone red, and isoindololinone yellow.

[0016] Furthermore, based on the total weight of the resin layer, the weight percentage of the composite pigment in the resin layer is 0.5% to 10%.

[0017] Furthermore, the thickness of the infrared reflective single-layer black encapsulating film is 200~600μm.

[0018] Furthermore, the thickness of the infrared reflective single-layer black encapsulating film is 300~500μm.

[0019] Furthermore, the raw materials for the resin layer include 100 parts by weight of matrix resin, 0.01 to 5 parts by weight of crosslinking agent, 0.01 to 5 parts by weight of co-crosslinking agent, 0.05 to 5 parts by weight of ultraviolet absorber and 0 to 3 parts by weight of processing aid.

[0020] Furthermore, based on the total weight of the resin layer, the weight percentage of the composite pigment in the resin layer is 1% to 5%.

[0021] Furthermore, the thickness of the infrared reflective single-layer black encapsulating film is 300~500μm.

[0022] Furthermore, the matrix resin is selected from at least one of ethylene-vinyl acetate copolymer, metallocene-catalyzed polyethylene, metallocene-catalyzed ethylene-butene copolymer, metallocene-catalyzed ethylene-octene copolymer, ethylene-α-olefin copolymer, polyvinyl butyral, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-butyl acrylate copolymer, metallocene-catalyzed polyethylene, metallocene-catalyzed ethylene-butene copolymer, metallocene-catalyzed ethylene-octene copolymer, and metallocene-catalyzed ethylene-pentene copolymer.

[0023] Furthermore, the crosslinking agent is selected from at least one of the following: bis(tert-butylperoxy)propylbenzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-pentylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-pentylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, cumene peroxide, and di-tert-butylperoxide.

[0024] Furthermore, the crosslinking agent is selected from at least one of tris(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, propionylated pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, ethoxylated trimethylolpropane triacrylate, propionylated trimethylolpropane triacrylate, ethoxylated glycerol triacrylate, propionylated glycerol triacrylate, and bis(trimethylolpropane tetraacrylate).

[0025] Furthermore, the ultraviolet absorber is selected from 2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 4-methoxy-2-hydroxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-(2'-hydroxy-5'-methylphenyl) At least one of benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-pentylphenyl)benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-tert-butylphenyl)benzotriazole, and 2-(2'-hydroxy-5'-aminophenyl)benzotriazole.

[0026] Furthermore, the processing aid is selected from at least one of antioxidants and coupling agents.

[0027] According to a second aspect of this application, a method for preparing the above-mentioned infrared reflective single-layer black encapsulating film is provided, comprising the following steps:

[0028] Step S1: Mix the first pigment and the second pigment to form a composite pigment; wherein the first pigment is an infrared reflective pigment, and the second pigment is an infrared transmissive pigment and / or an infrared reflective pigment;

[0029] Step S2: Mix the composite pigment and matrix resin, extrude and granulate to obtain black masterbatch;

[0030] Step S3: Cast and shape the black masterbatch to obtain an infrared reflective single-layer black encapsulating film; wherein, the Lab chromaticity values ​​of the infrared reflective single-layer black encapsulating film are: L = 11~20, a = -4~4, b = -4~4.

[0031] Furthermore, in step S3, the conditions for casting and setting include: a temperature of 80~130℃ and a time of 15~60min.

[0032] Furthermore, based on the total weight of the resin layer, the weight percentage of the composite pigment in the resin layer is 0.5% to 10%.

[0033] Furthermore, based on the total weight of the resin layer, the weight percentage of the composite pigment in the resin layer is 1% to 5%.

[0034] Furthermore, the weight ratio of the first pigment to the second pigment is (30~60):(40~70).

[0035] Furthermore, the reflectance of the first pigment in the 760~1100nm range is >70%.

[0036] Furthermore, the raw materials for the resin layer include 100 parts by weight of matrix resin, 0.01 to 5 parts by weight of crosslinking agent, 0.01 to 5 parts by weight of co-crosslinking agent, 0.05 to 5 parts by weight of ultraviolet absorber and 0 to 3 parts by weight of processing aid.

[0037] Furthermore, the thickness of the infrared reflective single-layer black encapsulating film is 200~600μm.

[0038] Furthermore, the first pigment is selected from at least one of chromium oxide pigments, metal oxide pigments, metal oxide mixed phase pigments, and ceramic pigments.

[0039] Furthermore, the first pigment is selected from at least one of chromium oxide yellow, chromium oxide green, cobalt chromium blue, titanium nickel yellow, bismuth vanadate yellow, antimony tin gray, chromium titanium brown, chromium tin red, cobalt aluminum blue, aluminum oxide, titanium oxide, barium oxide, and zirconium oxide.

[0040] Furthermore, the second pigment is at least one of perylene pigments, quinacridone pigments, pyrrolopyrroledione pigments, indolinone pigments, isoindolinone pigments, and phthalocyanine pigments.

[0041] Furthermore, the second pigment is selected from one or more of indololinone yellow, DPP red, perylene red, perylene black, copper phthalocyanine blue, phthalocyanine green, quinacridone red, and isoindololinone yellow. Further, the matrix resin is selected from at least one of ethylene-vinyl acetate copolymer, metallocene-catalyzed polyethylene, metallocene-catalyzed ethylene-butene copolymer, metallocene-catalyzed ethylene-octene copolymer, metallocene-catalyzed ethylene-pentene copolymer, ethylene-propylene copolymer, ethylene-methyl acrylate copolymer, and ethylene-methyl methacrylate copolymer.

[0042] Furthermore, based on the total weight of the resin layer, the weight percentage of the composite pigment in the resin layer is 1% to 5%.

[0043] According to a third aspect of this application, a photovoltaic module is provided, including a front panel, an upper encapsulating film, a cell layer, a lower encapsulating film, and a back panel; the upper encapsulating film and / or the lower encapsulating film are the above-mentioned infrared reflective single-layer black encapsulating film or the infrared reflective single-layer black encapsulating film obtained by the above-mentioned preparation method.

[0044] Compared with the prior art, this application has the following beneficial effects:

[0045] This application provides a single-layer black film with ultra-high infrared reflectivity. By formulating a composite black pigment formulation with ultra-high infrared reflectivity using a three-primary-color mechanism, and by compounding infrared high reflectivity color pigments with other infrared high transmittance pigments or infrared high reflectivity pigments, a single-layer black film with ultra-high infrared reflectivity (760~1100nm reflectivity >70%) is obtained. The single-layer black film has a simple structure, reduces the difficulty of the process (the process of traditional black and white composite film is complicated), and avoids the appearance instability and easy migration (pigments in traditional black and white composite film are easy to migrate with each other). Detailed Implementation

[0046] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present application will now be described in detail with reference to the embodiments.

[0047] As described in the background section, black encapsulant films used in photovoltaic modules employ reflective black pigments (such as copper chromium black, titanium dioxide, iron chromium black, Black0024, Black0026, CIPigment Black32, and Black10C909) to achieve infrared reflectivity. However, due to the limitations of their black appearance, the infrared reflectivity of such products is capped at no more than 60%. Alternatively, a black encapsulant film layer (with black-based permeable fillers added to ensure color) and a white encapsulant film layer can be added to increase reflectivity and thus improve the power generation efficiency of black photovoltaic modules. However, this two-layer structure not only increases the processing difficulty but also introduces the risk of pigment migration between the black and white layers. To resolve the irreconcilable contradiction between the black appearance and high infrared reflectivity of photovoltaic module encapsulant films, this application develops a single-layer black encapsulant film with ultra-high infrared reflectivity.

[0048] According to a first aspect of this application, a single-layer black encapsulating film with ultra-high infrared reflectivity is provided, comprising a resin layer and a composite pigment; the composite pigment is distributed in the resin layer; wherein the composite pigment includes a first pigment and a second pigment; the first pigment includes an infrared reflective pigment, and the second pigment is an infrared transmissive pigment and / or an infrared reflective pigment; the Lab chromaticity value of the infrared reflective single-layer black encapsulating film is: L is 11~20, a is -4~4, b is -4~4.

[0049] In the Lab chromaticity value of the aforementioned infrared reflective single-layer black encapsulating film, L can be any value from 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 or any value between any two; a can be any value from -4, -0.35, -3, -0.25, -2, -1.5, -1, -0.50, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4 or any value between any two; b can be any value from -4, -0.35, -3, -0.25, -2, -1.5, -1, -0.50, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4 or any value between any two.

[0050] The single-layer black film with ultra-high infrared reflectivity developed in this application is obtained by formulating a composite black pigment with ultra-high infrared reflectivity using a three-primary-color mechanism, and by compounding infrared high reflectivity pigments with other infrared high transmittance pigments or infrared high reflectivity pigments of opposite color systems to form a composite pigment with a target chromaticity value, ultimately obtaining a single-layer black film with ultra-high infrared reflectivity; the reflectivity of this black film for infrared light with wavelengths of 760~1100nm is >70%; the single-layer black film has a simple structure, low processing difficulty, and avoids the problems of unstable appearance and easy pigment migration in double-layer structures.

[0051] By adjusting the Lab color value of the film within the above range, the film appears deep black or jet black, balancing the visual blackness and natural gloss, giving the module an advanced black and mirror black appearance, meeting the aesthetic requirements of high-end modules such as TOPCon and HJT; and while maintaining this black appearance, the film achieves an infrared reflectance of >70% in the 760~1100nm range, achieving a balance between blackness and infrared reflectance.

[0052] To achieve an infrared reflectance of >70% in the 760~1100nm range of the film, a pigment with high infrared reflectance is selected. In some specific embodiments, the first pigment has a reflectance of >70% in the 760~1100nm range; for example, a reflectance of 70~80%. Selecting the above-mentioned pigment ensures that the film has a good black appearance while still having high infrared reflectance.

[0053] To achieve both a good black appearance and high infrared reflectivity in the film, a suitable infrared-reflective pigment is selected. In some specific embodiments, the first pigment is at least one of chromium oxide pigments, metal oxide pigments, metal oxide mixed-phase pigments, and ceramic pigments. For example, the first pigment is selected from one or more of chromium oxide yellow, cobalt chromium blue, titanium nickel yellow, bismuth vanadate yellow, antimony tin gray, chromium titanium brown, chromium tin red, cobalt aluminum blue, aluminum oxide, titanium oxide, barium oxide, and zirconium oxide. The second pigment is selected from at least one of perylene pigments, quinacridone pigments, pyrrolopyrroledione pigments, indolinone pigments, isoindolinone pigments, and phthalocyanine pigments. For example, the second pigment is selected from one or more of indolinone yellow, DPP red, perylene red, perylene black, copper phthalocyanine green, quinacridone red, and isoindolinone yellow. By combining the above-mentioned infrared reflective and infrared transmissive pigments, the film exhibits high infrared reflectivity in the 760~1100nm wavelength range. Furthermore, the material has a stable crystal structure, good weather resistance, no migration, and a visually black appearance, making it perfectly suitable for photovoltaic encapsulation films.

[0054] To achieve a single-layer black film with high infrared reflectivity and color stability, the mixing ratio of the two pigments is controlled. In some specific embodiments, the weight ratio of the first pigment to the second pigment is (30~60):(40~70). For example, the weight ratio of the first pigment can be any value from 30, 35, 40, 45, 50, 55, 60, or any value between any two; the weight ratio of the second pigment can be any value from 40, 45, 50, 55, 60, 65, 70, or any value between any two. The first pigment ensures that the film has high infrared reflectivity, while the second pigment ensures sufficient visible light absorption, achieving a deep black with an L value ≤ 20. The first pigment provides light reflection capability, and the second pigment provides light absorption capability. By controlling the weight ratio within the above range, the infrared reflectivity of the film can be in the range of 70%~80%, achieving a reasonable Lab chromaticity value and exhibiting a pure neutral black. The two pigments are evenly dispersed, improving processing stability. Ultimately, a single-layer structure of the film replaces the double-layer structure, increasing the yield to 100%.

[0055] To obtain a high infrared reflectance single-layer black film, more suitable pigments are selected for compounding. In some specific embodiments, the first pigment selected is chromium oxide yellow, and the second pigment is a combination of perylene black pigment and quinacridone red pigment, with the weight ratio of chromium oxide yellow, perylene black pigment, and quinacridone red pigment being (35~50):(25~35):(25~30); or, the first pigment is chromium oxide green, and the second pigment is a combination of perylene black pigment and quinacridone red pigment, with the weight ratio of chromium oxide green, perylene black pigment, and quinacridone red pigment being (40~60):(20~30):(20~30); or, the first pigment is cobalt chromium blue, and the second pigment is a combination of perylene black pigment and quinacridone red pigment, with the weight ratio of cobalt chromium blue, perylene black pigment, and quinacridone red pigment being (30~45):(25~35):(30~35). By selecting the above-mentioned pigment blend, the film can achieve an L of 12~18, a of 0.05~0.2, and b of -0.1~0.2; and the film will be dark black or jet black, with an infrared reflectance of >70% in the 760~1100nm range, thus achieving a balance between blackness and infrared reflectance.

[0056] In some specific embodiments, the weight percentage of the composite pigment in the resin layer is 0.5% to 10% based on the total weight of the resin layer; for example, any value or range between any two of 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, and 10%; further, 1% to 5%, and even more specifically, 2% to 4%. Controlling the content of the composite pigment within the above range allows the film to have a high-grade black color and high infrared reflectivity, while ensuring sufficient pigment dispersion, avoiding agglomeration and sedimentation, and giving the resin good mechanical properties, reliable encapsulation performance, and good processability.

[0057] In some specific embodiments, the thickness of the infrared reflective single-layer black encapsulating film is 200~600μm; for example, any value among 200μm, 300μm, 400μm, 500μm, and 600μm, or any value in between; another example is 300~500μm. When the black film has the above thickness, it can ensure that infrared light achieves an effective reflection path, improve photoelectric conversion efficiency, and at the same time maintain the balance between the mechanical strength and flexibility of the film.

[0058] In some specific embodiments, the raw materials for the resin layer include 100 parts by weight of matrix resin, 0.01 to 5 parts by weight of crosslinking agent, 0.01 to 5 parts by weight of co-crosslinking agent, 0.05 to 5 parts by weight of ultraviolet absorber and 0 to 3 parts by weight of processing aid. For example, based on 100 parts by weight of the matrix resin, the amount of crosslinking agent is any value or a range between any two of the following: 0.01 parts by weight, 0.02 parts by weight, 0.05 parts by weight, 0.08 parts by weight, 0.1 parts by weight, 0.2 parts by weight, 0.5 parts by weight, 0.8 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight, 4.5 parts by weight, and 5 parts by weight; the amount of co-crosslinking agent is 0.01 parts by weight, 0.02 parts by weight, 0.05 parts by weight, 0.08 parts by weight, 0.1 parts by weight, 0.2 parts by weight, 0.5 parts by weight, 0.8 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, and 3 parts by weight. The amount of UV absorber is any value or a range between any two of the following: 0.05 parts by weight, 0.08 parts by weight, 0.1 parts by weight, 0.2 parts by weight, 0.5 parts by weight, 0.8 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight, 4.5 parts by weight, 5 parts by weight; the amount of processing aid is any value or a range between any two of the following: 0, 0.1 parts by weight, 0.2 parts by weight, 0.5 parts by weight, 0.8 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight.

[0059] Specifically, the matrix resin is a commonly used matrix resin in this field, including but not limited to any one or more of the following: ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, polyvinyl butyral, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-butyl acrylate copolymer, metallocene-catalyzed polyethylene, metallocene-catalyzed ethylene-butene copolymer, metallocene-catalyzed ethylene-octene copolymer, and metallocene-catalyzed ethylene-pentene copolymer. Selecting the above-mentioned matrix resin can improve long-term blackness stability, aging resistance, and yellowing resistance, thus achieving long-term outdoor durability of the film. The crosslinking agent is a commonly used crosslinking agent in this field, including but not limited to any one or more of the following: bis(tert-butylperoxy)cyclohexane, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-amylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-amylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, cumene peroxide, and di-tert-butylperoxide. The selected crosslinking agents exhibit high crosslinking efficiency, high decomposition temperature, no byproducts, and do not react with organic pigments.

[0060] The co-crosslinking agent is a commonly used co-crosslinking agent in this field, including but not limited to any one or more of tris(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, propionyl oxylated pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, ethoxylated trimethylolpropane triacrylate, propionyl oxylated trimethylolpropane triacrylate, ethoxylated glycerol triacrylate, propionyl oxylated glycerol triacrylate, and bis(trimethylolpropane tetraacrylate). The selected co-crosslinking agent is used to synergistically improve the degree of crosslinking with the crosslinking agent.

[0061] The UV absorbers are commonly used UV absorbers in this field, including but not limited to 2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 4-methoxy-2-hydroxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-(2'-hydroxy-5'-carboxybenzophenone, etc.) At least one of the following: (2-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-pentylphenyl)benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-tert-butylphenyl)benzotriazole, and 2-(2'-hydroxy-5'-aminophenyl)benzotriazole. The above-mentioned UV absorber is selected to absorb ultraviolet light and maintain the long-term blackness of the film.

[0062] The processing aid is any one or more of the antioxidants and coupling agents commonly used in the art. Specifically, the antioxidants include, but are not limited to, one or more of the following: triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], 1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-trione, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanuric acid, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], and N,N'-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl]hexamethylenediamine. Coupling agents include, but are not limited to, one or more of γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, diethylaminomethyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltri(β-methoxyethoxy)silane. Using these processing aids can shield ultraviolet light, scavenge free radicals, and prevent the film from yellowing over a long period.

[0063] According to a second aspect of this application, a method for preparing the above-mentioned infrared reflective single-layer black encapsulating film is provided, comprising the following steps:

[0064] Step S1: Mix the first pigment and the second pigment to form a composite pigment; wherein the first pigment is an infrared reflective pigment, and the second pigment is an infrared transmittance pigment and / or an infrared reflective pigment;

[0065] Step S2: Mix the composite pigment and matrix resin, extrude and granulate to obtain black masterbatch;

[0066] Step S3: Cast and shape the black masterbatch to obtain an infrared reflective single-layer black encapsulating film; wherein, the Lab chromaticity values ​​of the infrared reflective single-layer black encapsulating film are: L = 11~20, a = -4~4, b = -4~4.

[0067] The above-mentioned method for preparing and shaping the cast film can be selected from existing technologies according to actual needs. This method is simple to operate.

[0068] In some specific embodiments, the conditions for casting and setting in step S3 include: a temperature of 80~130℃ and a time of 15~60min. These conditions are beneficial for the film forming effect.

[0069] In some specific embodiments, the composite pigment has a weight percentage of 0.5% to 10% in the resin layer, based on the total weight of the resin layer; for example, 1% to 5%. The prepared film has a high-grade black color and high infrared reflectivity, while ensuring sufficient pigment dispersion. The resin also exhibits good mechanical properties, reliable encapsulation performance, and good processability.

[0070] In some specific embodiments, the weight ratio of the first pigment to the second pigment is (30~60):(40~70). The prepared film has an infrared reflectance in the range of 70%~80%, exhibits a pure neutral black color, the two pigments are uniformly dispersed, the processing stability is high, and the yield is improved to 100%.

[0071] In some specific embodiments, the reflectance of the first pigment in the 760-1100 nm range is >70%. For example, the first pigment is at least one of chromium oxide pigments, metal oxide pigments, metal oxide mixed-phase pigments, and ceramic pigments. Specifically, the first pigment is selected from one or more of chromium oxide yellow, chromium oxide green, cobalt chromium blue, titanium nickel yellow, bismuth vanadate yellow, antimony tin gray, chromium titanium brown, chromium tin red, cobalt aluminum blue, aluminum oxide, titanium oxide, barium oxide, and zirconium oxide. The second pigment is selected from one or more of perylene pigments, quinacridone pigments, pyrrolopyrroledione pigments, indolinone pigments, isoindolinone pigments, and phthalocyanine pigments. Specifically, the second pigment is selected from one or more of indolinone yellow, DPP red, perylene red, perylene black, copper phthalocyanine blue, phthalocyanine green, quinacridone red, and isoindolinone yellow. The prepared encapsulant film exhibits high infrared reflectance characteristics in the 760~1100nm wavelength range, and the material has a stable crystal structure, good weather resistance, no migration, and a visually black appearance, making it perfectly suitable for photovoltaic encapsulation films.

[0072] In some specific embodiments, the raw materials for the resin layer include 100 parts by weight of a matrix resin, 0.01 to 5 parts by weight of a crosslinking agent, 0.01 to 5 parts by weight of a co-crosslinking agent, 0.05 to 5 parts by weight of a UV absorber, and 0 to 3 parts by weight of a processing aid. The prepared film exhibits long-term blackness and high infrared reflectivity, and also possesses long-term weather resistance and a long service life.

[0073] In some specific embodiments, the thickness of the infrared reflective single-layer black encapsulating film is 200~600μm. Preparing a film of this thickness ensures an effective reflection path for infrared light, improves photoelectric conversion efficiency, and maintains a balance between the film's mechanical strength and flexibility.

[0074] In some specific embodiments, the raw materials for the resin layer include 100 parts by weight of a matrix resin, 0.01 to 5 parts by weight of a crosslinking agent, 0.01 to 5 parts by weight of a co-crosslinking agent, 0.05 to 5 parts by weight of a UV absorber, and 0 to 3 parts by weight of a processing aid. The specific selection of the matrix resin, crosslinking agent, co-crosslinking agent, UV absorber, and processing aid is as described above and will not be repeated here.

[0075] According to a third aspect of this application, a photovoltaic module is provided, including a front panel, an upper encapsulating film, a cell layer, a lower encapsulating film, and a back panel; the upper encapsulating film and / or the lower encapsulating film are the above-mentioned infrared reflective single-layer black encapsulating film or the infrared reflective single-layer black encapsulating film obtained by the above-mentioned preparation method.

[0076] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0077] The raw materials used in the embodiments of this application are all existing technologies and are commercially available.

[0078] Example 1

[0079] Step S1: Mix chromium oxide yellow pigment (first pigment, BASF, reflectance = 90% (760~1100nm), perylene black pigment (second pigment, BASF) and quinacridone red pigment (second pigment, BASF) in a weight ratio of 50:25:25 to form a composite pigment.

[0080] Step S2: The composite pigment and resin raw material (the composite pigment accounts for 3 wt% of the resin raw material) are mixed according to the formula and extruded and granulated in a single screw extruder to obtain black masterbatch; wherein, the resin raw material includes 100 parts by weight of ethylene-vinyl acetate copolymer, 0.5 parts of bis-tert-butylperoxyisopropylbenzene (crosslinking agent), 0.5 parts of tris(2-hydroxyethyl)isocyanurate triacrylate (co-crosslinking agent), 0.5 parts of 2-hydroxy-4-methoxybenzophenone (ultraviolet absorber), 0.5 parts of triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (antioxidant), and 0.5 parts of γ-aminopropyltriethoxysilane (coupling agent);

[0081] Step S3: Cast the black masterbatch and set it under the following conditions: temperature 90℃, time 20min; obtain an infrared reflective single-layer black encapsulating film; the thickness of the single-layer black encapsulating film is measured to be 300μm; the Lab colorimetric value of the film is measured to be: L=15, a=0.1, b=-0.1.

[0082] Example 2

[0083] Step S1: Mix chromium oxide green pigment (first pigment, BASF, reflectance = 90% (760~1100nm), perylene black pigment (second pigment) and quinacridone red pigment (second pigment) in a weight ratio of 60:20:20 to form a composite pigment;

[0084] Step S2: The composite pigment and resin raw material (the composite pigment accounts for 3 wt% of the resin raw material) are mixed according to the formula, and extruded and granulated in a single screw extruder to obtain black masterbatch; wherein, the resin raw material includes 100 parts by weight of ethylene-vinyl acetate copolymer, 1 part of bis-tert-butylperoxyisopropylbenzene (crosslinking agent), 0.5 parts of tris(2-hydroxyethyl)isocyanurate triacrylate (co-crosslinking agent), 0.5 parts of 2-hydroxy-4-methoxybenzophenone (ultraviolet absorber), 0.5 parts of triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (antioxidant), and 0.5 parts of γ-aminopropyltriethoxysilane (coupling agent);

[0085] Step S3: Cast the black masterbatch and set it under the following conditions: temperature 90℃, time 15min; obtain an infrared reflective single-layer black encapsulating film; the thickness of the single-layer black encapsulating film is 350μm; the Lab colorimetric value of the film is L=17, a=0.12, b=0.1.

[0086] Example 3

[0087] Step S1: Mix cobalt chromium blue pigment (first pigment, BASF, reflectance = 90% (760~1100nm), perylene black pigment (second pigment) and quinacridone red pigment (second pigment) in a weight ratio of 30:35:35 to form a composite pigment;

[0088] Step S2: The composite pigment and resin raw material (the composite pigment accounts for 3 wt% of the resin raw material) are mixed according to the formula, and extruded and granulated in a single screw extruder to obtain black masterbatch; wherein, the resin raw material includes 100 parts by weight of ethylene-vinyl acetate copolymer, 1 part of bis-tert-butylperoxyisopropylbenzene (crosslinking agent), 0.5 parts of tris(2-hydroxyethyl)isocyanurate triacrylate (co-crosslinking agent), 0.5 parts of 2-hydroxy-4-methoxybenzophenone (ultraviolet absorber), 0.5 parts of triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (antioxidant), and 0.5 parts of γ-aminopropyltriethoxysilane (coupling agent);

[0089] Step S3: Cast the black masterbatch and set it under the following conditions: temperature 90℃, time 20min; obtain an infrared reflective single-layer black encapsulating film; the thickness of the single-layer black encapsulating film is 350μm; the Lab colorimetric value of the film is L=12, a=0.05, b=0.18.

[0090] Example 4

[0091] The difference between Example 4 and Example 1 is that the weight ratio of chromium oxide yellow (first pigment), perylene black pigment (second pigment) and quinacridone red pigment (second pigment) in step S1 is replaced with 35:35:30; the Lab color values ​​of the film are: L=13, a=0.05, b=-0.1.

[0092] Example 5

[0093] The difference between Example 5 and Example 1 is that the weight ratio of chromium oxide yellow (first pigment), perylene black pigment (second pigment) and quinacridone red pigment (second pigment) in step S1 is replaced with 40:30:30; the Lab color values ​​of the film are: L=14, a=0.05, b=0.1.

[0094] Example 6

[0095] The difference between Example 6 and Example 1 is that the weight ratio of chromium oxide yellow (first pigment), perylene black pigment (second pigment) and quinacridone red pigment (second pigment) in step S1 is replaced with 45:25:30; the Lab color values ​​of the film are: L=14.5, a=0.1, b=0.1.

[0096] Example 7

[0097] Example 7 differs from Example 1 in that the proportion of the composite pigment in the resin raw material in step S2 is replaced with 2 wt%. The Lab colorimetric values ​​of the film were measured as follows: L=18, a=0.1, b=-0.1.

[0098] Example 8

[0099] Example 8 differs from Example 1 in that the proportion of the composite pigment in the resin raw material in step S2 is replaced with 1 wt%. The Lab colorimetric values ​​of the film were measured as follows: L=19, a=0.1, b=-0.1.

[0100] Example 9

[0101] Example 9 differs from Example 1 in that the proportion of the composite pigment in the resin raw material in step S2 is replaced with 5 wt%. The Lab colorimetric values ​​of the film were measured as follows: L=11, a=0.1, b=-0.1.

[0102] Example 10

[0103] Example 10 differs from Example 1 in that the proportion of the composite pigment in the resin raw material in step S2 is replaced with 0.5 wt%. The Lab colorimetric values ​​of the film were measured as follows: L=17, a=0.1, b=-0.1.

[0104] Example 11

[0105] Example 11 differs from Example 1 in that the proportion of the composite pigment in the resin raw material in step S2 is replaced with 10wt%. The Lab colorimetric values ​​of the film were measured as follows: L=11, a=0.1, b=-0.1.

[0106] Example 12

[0107] The difference between Example 12 and Example 1 is that the resin raw material formulation in step S2 is replaced with: the resin raw material includes 100 parts by weight of metallocene-catalyzed ethylene-butene copolymer, 1 part of bis(2-tert-butylperoxyisopropyl)benzene (crosslinking agent), 0.5 parts of tris(2-hydroxyethyl)isocyanurate triacrylate (co-crosslinking agent), 0.5 parts of 2-hydroxy-4-methoxybenzophenone (ultraviolet absorber), 0.5 parts of triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (antioxidant), and 0.5 parts of γ-aminopropyltriethoxysilane (coupling agent); the Lab colorimetric value of the film was tested: L=15, a=0.1, b=-0.1.

[0108] Example 13

[0109] Example 13 differs from Example 1 in that the resin raw material formulation in step S2 is replaced with: the resin raw material includes 100 parts by weight of ethylene-propylene copolymer, 1 part of bis(2-tert-butylperoxyisopropyl)benzene (crosslinking agent), 0.5 parts of tris(2-hydroxyethyl)isocyanurate triacrylate (co-crosslinking agent), 0.5 parts of 2-hydroxy-4-methoxybenzophenone (UV absorber), 0.5 parts of triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (antioxidant), and 0.5 parts of γ-aminopropyltriethoxysilane (coupling agent). The Lab colorimetric value of the film was measured as follows: L=15, a=0.1, b=-0.1.

[0110] Example 14

[0111] Example 14 differs from Example 1 in that the resin raw material formulation in step S2 is replaced with: the resin raw material includes 100 parts by weight of ethylene-methyl acrylate copolymer, 1 part of 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexyne-3 (crosslinking agent), 0.5 parts of tris(2-hydroxyethyl)isocyanurate triacrylate (co-crosslinking agent), 0.5 parts of 2-hydroxy-4-methoxybenzophenone (UV absorber), 0.5 parts of triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (antioxidant), and 0.5 parts of γ-aminopropyltriethoxysilane (coupling agent). The Lab colorimetric value of the film was measured as follows: L=15, a=0.1, b=-0.1.

[0112] Example 15

[0113] Example 15 differs from Example 1 in that the thickness of the single-layer black encapsulating film in step S3 is replaced with 200 μm. The Lab chromaticity values ​​of the film were measured as follows: L=15, a=0.1, b=-0.1.

[0114] Example 16

[0115] Example 16 differs from Example 1 in that the thickness of the single-layer black encapsulating film in step S3 is replaced with 600 μm. The Lab chromaticity values ​​of the film were measured as follows: L=13, a=0.1, b=-0.1.

[0116] Example 17

[0117] The difference between Example 17 and Example 1 is that in step S1: antimony tin gray pigment (first pigment, Hunan Kohler pigment, reflectance = 80% (760~1100nm), perylene red pigment (second pigment, BASF) and phthalocyanine green pigment (second pigment, BASF) are mixed in a weight ratio of 40:20:30 to form a composite pigment; the Lab colorimetric values ​​of the film are: L=11, a=0.12, b=-0.23.

[0118] Example 18

[0119] The difference between Example 18 and Example 1 is that in step S1: titanium oxide (first pigment, BASF, reflectance = 95% (760~1100nm), perylene black (second pigment) and perylene red (second pigment) are mixed in a weight ratio of 45:30:25 to form a composite pigment; the Lab color values ​​of the film are: L=17, a=1.23, b=0.12.

[0120] Example 19

[0121] The difference between Example 19 and Example 1 is that in step S1: titanium oxide (first pigment, BASF, reflectance = 95% (760~1100nm), phthalocyanine green (second pigment) and DPP red (second pigment, BASF) are mixed in a weight ratio of 50:30:20 to form a composite pigment; the Lab colorimetric values ​​of the film are: L=16, a=-1.45, b=1.73.

[0122] Example 20

[0123] The difference between Example 20 and Example 1 is that in step S1, titanium oxide (first pigment, BASF, reflectance = 95% (760~1100nm) and perylene black (second pigment) are mixed in a weight ratio of 70:30 to form a composite pigment; the Lab color values ​​of the film are: L=17, a=-1.89, b=2.13.

[0124] Example 21

[0125] The difference between Example 20 and Example 1 is that in step S1, chromium oxide green (first pigment, BASF, reflectance = 90% (760~1100nm)) and perylene red (second pigment) are mixed in a weight ratio of 60:40 to form a composite pigment; the Lab color values ​​of the film are: L=14, a=0.27, b=-0.76.

[0126] Comparative Example 1

[0127] The difference between Comparative Example 1 and Example 1 is that the composite pigment in step S1 is replaced with pure carbon black N660.

[0128] Comparative Example 2

[0129] The difference between Comparative Example 2 and Example 1 is that the composite pigment in step S1 is replaced with perylene black pigment and titanium dioxide in a weight ratio of 1:1.

[0130] Comparative Example 3

[0131] The difference between Comparative Example 3 and Example 1 is that Comparative Example 3 has a double-layer structure, in which perylene black pigment is added to the front layer and titanium dioxide is added to the back layer (the ratio of pigment to matrix resin raw material in each layer is the same as in Example 1); a double-layer composite film is obtained by double-layer co-extrusion casting and shaping.

[0132] Performance testing:

[0133] The Lab colorimetric value and the infrared reflectance of the encapsulating films in the examples and comparative examples were tested using the standard method of GB / T 29848-2018. The results are shown in Table 1.

[0134] Table 1

[0135]

[0136] The test results in Table 1 show that:

[0137] Compared with Comparative Examples 1-2, the infrared reflectance of the film in Examples 1-21 of this application is as high as 80%, which is significantly higher than 2% of Comparative Example 1; the L value is <20, which is significantly lower than 22 of Comparative Example 2.

[0138] Compared with Comparative Example 3, Examples 1-21 of this application only have a single layer of black adhesive film, which can achieve ultra-high infrared reflectivity, simplify the process, avoid the mutual migration of black and white pigments in the film layer, ensure the stability of the adhesive film structure, and achieve 100% yield in the appearance of the module.

[0139] By applying the single-layer black film with ultra-high infrared reflectivity provided in this application, a composite black pigment formulation with ultra-high infrared reflectivity is prepared using a three-primary-color mechanism. This formulation is obtained by compounding infrared high reflectivity colored pigments with other infrared high transmittance pigments or infrared high reflectivity pigments. The single-layer black film has a simple structure, which reduces the difficulty of the process (the process of traditional black and white composite film is complicated) and avoids the instability and easy migration of appearance (pigments in traditional black and white composite film are easy to migrate with each other).

[0140] It should be noted that the terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those described herein.

[0141] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An infrared reflective single-layer black encapsulating film, characterized in that, The infrared reflective single-layer black encapsulating film comprises a resin layer and a composite pigment; the composite pigment is distributed in the resin layer. The composite pigment includes a first pigment and a second pigment; the first pigment is an infrared reflective pigment, and the second pigment is an infrared transmissive pigment and / or an infrared reflective pigment. The Lab chromaticity values ​​of the infrared reflective single-layer black encapsulating film are: L = 11~20, a = -4~4, b = -4~4.

2. The infrared reflective single-layer black encapsulating film according to claim 1, characterized in that, The first pigment has a reflectance of >70% in the 760~1100nm range; And / or, the first pigment is selected from at least one of chromium oxide pigments, metal oxide pigments, metal oxide mixed phase pigments, and ceramic pigments; And / or, the second pigment is selected from at least one of perylene pigments, quinacridone pigments, pyrrolopyrroledione pigments, indolineone pigments, isoindolineone pigments, and phthalocyanine pigments.

3. The infrared reflective single-layer black encapsulating film according to claim 1, characterized in that, The weight ratio of the first pigment to the second pigment is (30~60):(40~70); And / or, the first pigment is selected from at least one of chromium oxide yellow, chromium oxide green, cobalt chromium blue, titanium nickel yellow, bismuth vanadate yellow, antimony tin gray, chromium titanium brown, chromium tin red, cobalt aluminum blue, aluminum oxide, titanium oxide, barium oxide, and zirconium oxide; And / or, the second pigment is selected from at least one of indololinone yellow, DPP red, perylene red, perylene black, copper phthalocyanine blue, phthalocyanine green, quinacridone red, and isoindololinone yellow.

4. The infrared reflective single-layer black encapsulating film according to any one of claims 1 to 3, characterized in that, Based on the total weight of the resin layer, the composite pigment has a weight percentage of 0.5% to 10% in the resin layer; And / or, the thickness of the infrared reflective single-layer black encapsulating film is 200~600μm.

5. The infrared reflective single-layer black encapsulating film according to any one of claims 1 to 3, characterized in that, The raw materials of the resin layer include 100 parts by weight of matrix resin, 0.01 to 5 parts by weight of crosslinking agent, 0.01 to 5 parts by weight of co-crosslinking agent, 0.05 to 5 parts by weight of ultraviolet absorber and 0 to 3 parts by weight of processing aid. And / or, based on the total weight of the resin layer, the composite pigment in the resin layer comprises 1% to 5% by weight; And / or, the thickness of the infrared reflective single-layer black encapsulating film is 300~500μm.

6. The infrared reflective single-layer black encapsulating film according to claim 5, characterized in that, The matrix resin is selected from at least one of ethylene-vinyl acetate copolymer, ethylene-α-olefin copolymer, polyvinyl butyral, ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-butyl acrylate copolymer, metallocene-catalyzed polyethylene, metallocene-catalyzed ethylene-butene copolymer, metallocene-catalyzed ethylene-octene copolymer, and metallocene-catalyzed ethylene-pentene copolymer. And / or, the crosslinking agent is selected from at least one of bis-tert-butylperoxyisopropylbenzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-pentylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-pentylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, cumene peroxide, and di-tert-butylperoxide; And / or, the co-crosslinking agent is selected from at least one of tris(2-hydroxyethyl)isocyanurate triacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, propionyl oxylated pentaerythritol tetraacrylate, trimethylolpropane tetraacrylate, ethoxylated trimethylolpropane triacrylate, propionyl oxylated trimethylolpropane triacrylate, ethoxylated glycerol triacrylate, propionyl glycerol triacrylate, and bis(trimethylolpropane tetraacrylate); And / or, the ultraviolet absorber is selected from 2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 4-methoxy-2-hydroxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-(2'-hydroxy-5'-methylbenzene) At least one of the following: 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-3',5'-di-tert-pentylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, 2-(2'-hydroxy-5'-tert-butylphenyl)benzotriazole, and 2-(2'-hydroxy-5'-aminophenyl)benzotriazole; And / or, the processing aid is selected from at least one of antioxidants and coupling agents.

7. A method for preparing an infrared reflective single-layer black encapsulating film according to any one of claims 1 to 6, characterized in that, The preparation method includes the following steps: Step S1: Mix the first pigment and the second pigment to form a composite pigment; wherein the first pigment is an infrared reflective pigment, and the second pigment is an infrared transmissive pigment and / or an infrared reflective pigment; Step S2: The composite pigment and matrix resin are mixed, extruded, and granulated to obtain black masterbatch; Step S3: Cast the black masterbatch to obtain an infrared reflective single-layer black encapsulating film; wherein the Lab chromaticity values ​​of the infrared reflective single-layer black encapsulating film are: L = 11~20, a = -4~4, b = -4~4.

8. The preparation method according to claim 7, characterized in that, In step S3, the conditions for casting and setting include: temperature of 80~130℃ and time of 15~60min; And / or, based on the total weight of the resin layer, the composite pigment in the resin layer comprises 0.5% to 10% by weight; And / or, the weight ratio of the first pigment to the second pigment is (30~60):(40~70); And / or, the first pigment has a reflectance of >70% at 760~1100 nm; And / or, the raw materials of the resin layer include 100 parts by weight of matrix resin, 0.01 to 5 parts by weight of crosslinking agent, 0.01 to 5 parts by weight of co-crosslinking agent, 0.05 to 5 parts by weight of ultraviolet absorber and 0 to 3 parts by weight of processing aid; And / or, the thickness of the infrared reflective single-layer black encapsulating film is 200~600μm.

9. The preparation method according to claim 8, characterized in that, The first pigment is selected from at least one of chromium oxide pigments, metal oxide pigments, metal oxide mixed-phase pigments, and ceramic pigments; Preferably, the first pigment is selected from at least one of chromium oxide yellow, chromium oxide green, cobalt chromium blue, titanium nickel yellow, bismuth vanadate yellow, antimony tin gray, chromium titanium brown, chromium tin red, cobalt aluminum blue, aluminum oxide, titanium oxide, barium oxide, and zirconium oxide; And / or, the second pigment is selected from at least one of perylene pigments, quinacridone pigments, pyrrolopyrroledione pigments, indolinone pigments, isoindolinone pigments, and phthalocyanine pigments; preferably, the second pigment is selected from at least one of indolinone yellow, DPP red, perylene red, perylene black, copper phthalocyanine blue, phthalocyanine green, quinacridone red, and isoindolinone yellow; And / or, the matrix resin is selected from at least one of ethylene-vinyl acetate copolymer, metallocene-catalyzed polyethylene, metallocene-catalyzed ethylene-butene copolymer, metallocene-catalyzed ethylene-octene copolymer, metallocene-catalyzed ethylene-pentene copolymer, ethylene-propylene copolymer, ethylene-methyl acrylate copolymer, and ethylene-methyl methacrylate copolymer; And / or, based on the total weight of the resin layer, the composite pigment in the resin layer has a weight percentage of 1% to 5%.

10. A photovoltaic module, comprising a front panel, an upper encapsulating film, a cell layer, a lower encapsulating film, and a backsheet; characterized in that, The upper encapsulation film and / or the lower encapsulation film are either the infrared reflective single-layer black encapsulation film according to any one of claims 1 to 6 or the infrared reflective single-layer black encapsulation film obtained by the preparation method according to any one of claims 7 to 9.

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