Adhesive films for sealing and photovoltaic assemblies

Abstract

The present invention provides a sealing adhesive film and a photovoltaic assembly. The sealing adhesive film includes a high infrared transmittance adhesive film layer and a high infrared reflectance adhesive film layer laminated on the high infrared transmittance adhesive film layer, the high infrared transmittance adhesive film layer has a transmittance of more than 55% for light in the wavelength range of 700-1100 nm and a transmittance of less than 2% for light in the wavelength range of 400-700 nm, and the high infrared reflectance adhesive film layer has a reflectance of more than 75% for light in the wavelength range of 700-1100 nm. When the sealing adhesive film is used as the sealing adhesive film on the back surface of the cell sheet, it can not only realize the black appearance of the photovoltaic module and reduce light pollution, but also maximize the use of sunlight and improve the overall photoelectric conversion efficiency of the photovoltaic module, thereby improving the efficiency of the solar cell and extending its life. Furthermore, when the sealing adhesive film is used for BIPV building integration, it can achieve both the aesthetic appearance of the building and the efficiency of the photovoltaic module.

Description

[Technical field]

[0001] This application is based on and claims priority to a Chinese application with Chinese patent application number 202111593985.X, filed on December 24, 2021, the disclosure of which is hereby incorporated by reference in its entirety into this application.

[0002] The present invention relates to the technical field of photovoltaic assemblies, in particular to an adhesive sealing film and a photovoltaic assembly. [Background technology]

[0003] The solar cell body is used to realize the most basic function of a solar cell, which is to convert solar energy (light energy) into electrical energy, and it utilizes visible and near-infrared energy and also redistributes mid-infrared energy. The energy of solar radiation is mainly concentrated in the ultraviolet, visible, and infrared regions. Of these, the ultraviolet region accounts for 7% of the energy, the visible light region accounts for 50% of the energy, and the infrared region accounts for about 43% of the energy. Photovoltaic cells mainly absorb and utilize visible light of 400 to 700 nm. Infrared light with a wavelength of more than 1100 nm is not used to be converted into electrical energy by the cell sheet, but is directly converted into thermal energy, causing the internal temperature of the photovoltaic module to rise rapidly. Therefore, rational and effective utilization of sunlight is an effective way to improve the operating efficiency of solar cells.

[0004] However, in reality, current white adhesive films generally contain white pigments such as silicon oxide, silicon carbide, silicon nitride, titanium oxide, and titanium nitride, which can achieve high infrared reflectance, but cannot achieve high transmittance in the visible and near infrared range (0.38 to 1.1 μm).Current black adhesive films generally contain carbon black, but carbon black can only reflect 4% of infrared light in the infrared range and absorbs most infrared light, causing the temperature of the solar power generation module to rise.

[0005] Therefore, there is an urgent need to develop a new adhesive film structure that has high infrared reflectance while not affecting visible and near infrared transmittance. Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE PRESENT EMBODIMENT The main object of the present invention is to provide an adhesive sealing film and a photovoltaic assembly to solve the problem of low photoelectric conversion efficiency of the photovoltaic assembly in the prior art. [Means for solving the problem]

[0007] In order to achieve the above object, according to one embodiment of the present invention, there is provided an adhesive film for sealing, comprising a high infrared transmittance adhesive film layer and a high infrared reflectance adhesive film layer laminated on the high infrared transmittance adhesive film layer, wherein the high infrared transmittance adhesive film layer has a transmittance for light in the wavelength range of 700 to 1100 nm of greater than 55% and a transmittance for light in the wavelength range of 400 to 700 nm of less than 2%, and the high infrared reflectance adhesive film layer has a reflectance for light in the wavelength range of 700 to 1100 nm of greater than 75%.

[0008] Furthermore, the high infrared transmittance adhesive film layer has a transmittance of more than 58% for light in the wavelength range of 700 to 1100 nm, and a transmittance of less than 1% for light in the wavelength range of 400 to 700 nm.

[0009] Furthermore, the infrared high reflectance adhesive film layer has a reflectance of more than 85% for light in the wavelength range of 700 to 1100 nm.

[0010] Furthermore, the pressure-sensitive adhesive film for sealing has a reflectance of more than 70% for light in the wavelength range of 700 to 1100 nm.

[0011] Furthermore, the high infrared transmittance adhesive film layer contains a pigment, and the pigment is any one or more selected from fullerene and its derivatives, direct fast dyes, direct diazo dyes, direct cross dyes, and complex metal-containing azo dyes. The high infrared transmittance adhesive film layer contains, by weight, 100 parts of a first olefin resin, 0.01 to 10 parts of a pigment, 0.01 to 0.1 parts of a first coupling agent, 0.01 to 0.3 parts of a first crosslinking agent, and 0.01 to 0.3 parts of a first crosslinking aid, and the first olefin resin is any one or more selected from ethylene-vinyl acetate ester, ethylene-octene copolymer, ethylene-α-olefin copolymer, ethylene-methyl methacrylate copolymer, ethylene-methacrylic acid ionomer, and metallocene-catalyzed ethylene butene copolymer.

[0012] Furthermore, the infrared high reflectance adhesive film layer contains, by weight, 100 parts of a second olefin resin, 5 to 40 parts of a filler, 0.01 to 0.1 parts of a second coupling agent, 0.01 to 0.3 parts of a second crosslinking agent, and 0.01 to 0.3 parts of a second crosslinking aid, the second olefin resin being any one or more selected from ethylene-vinyl acetate ester, ethylene-α-olefin copolymer, ethylene-methyl methacrylate copolymer, ethylene-methacrylic acid ionomer, and metallocene-catalyzed ethylene butene copolymer, the filler being any one or more selected from titanium white, talcum powder, silica, aluminum hydroxide, magnesium hydroxide, alumina, boehmite, mica, kaolin, calcium carbonate, wollastonite, aluminum nitride, and boron nitride, and the particle size of the filler is 0.4 to 2.0 μm.

[0013] Furthermore, the infrared ray highly transmittance adhesive film layer has a thickness of 80 to 300 μm, and the infrared ray highly transmittance adhesive film layer is a pre-crosslinked film having a pre-crosslinking degree of 5 to 50%.

[0014] Furthermore, the infrared high reflectance adhesive film layer has a thickness of 120 to 500 μm, and the infrared high reflectance adhesive film layer is a pre-crosslinked film having a pre-crosslinking degree of 10 to 70%.

[0015] According to another aspect of the present invention, there is provided a photovoltaic assembly including a front transparent encapsulating layer, a first sealing adhesive film layer, a cell sheet array, a second sealing adhesive film layer, and a back encapsulating layer, wherein the second sealing adhesive film layer is the sealing adhesive film described above.

[0016] Furthermore, the high infrared transmittance adhesive film layer of the sealing adhesive film is provided in contact with a cell sheet of a photovoltaic assembly.

[0017] When the technical solution of the present invention is applied, the infrared ray transmittance adhesive film layer of the sealing adhesive film provided by the present application has a transmittance of more than 55% for light in the wavelength range of 700-1100 nm, the infrared ray transmittance adhesive film layer has a transmittance of less than 2% for light in the wavelength range of 400-700 nm, and the infrared ray reflectance adhesive film layer has a reflectance of more than 75% for light in the wavelength range of 700-1100 nm. Therefore, when the sealing adhesive film is used as the sealing adhesive film on the back side of the cell sheet, it can not only realize the black appearance of the photovoltaic power generation module and reduce light pollution, but also maximize the use of sunlight and improve the overall photoelectric conversion efficiency of the photovoltaic power generation module, thereby improving the efficiency and life of the solar cell. Furthermore, when the sealing adhesive film is used in the integration of BIPV into a building, it can achieve both the aesthetic appearance of the building and the efficiency of the photovoltaic power generation module. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] In addition, the embodiments and features of the embodiments of the present application may be combined with each other without contradiction.

[0019] As analyzed in the background art, the prior art has a problem in that the photovoltaic assembly has low photoelectric conversion efficiency. To solve this problem, the present invention proposes an adhesive sealing film and a photovoltaic assembly.

[0020] In one exemplary embodiment of the present application, a sealing adhesive film is provided, the sealing adhesive film including a high infrared transmittance adhesive film layer and a high infrared reflectance adhesive film layer laminated to the high infrared transmittance adhesive film layer, the high infrared transmittance adhesive film layer having a transmittance for light in the wavelength range of 700 to 1100 nm greater than 55% and a transmittance for light in the wavelength range of 400 to 700 nm less than 2%, and the high infrared reflectance adhesive film layer having a reflectance for light in the wavelength range of 700 to 1100 nm greater than 75%.

[0021] The high infrared transmittance adhesive film layer of the sealing adhesive film provided by the present application has a transmittance of more than 55% for light in the wavelength range of 700 to 1100 nm, the high infrared transmittance adhesive film layer has a transmittance of less than 2% for light in the wavelength range of 400 to 700 nm, and the high infrared reflectance adhesive film layer has a reflectance of more than 75% for light in the wavelength range of 700 to 1100 nm. Thus, when the sealing adhesive film is used as the sealing adhesive film on the back surface of the cell sheet, it can not only realize the black appearance of the photovoltaic power generation module and reduce light pollution, but also maximize the use of sunlight and improve the overall photoelectric conversion efficiency of the photovoltaic power generation module, thereby improving the efficiency and life of the solar cell. Furthermore, when the sealing adhesive film is used for BIPV building integration, it can achieve both the aesthetic appearance of the building and the efficiency of the photovoltaic power generation module.

[0022] The high infrared transmittance adhesive film layer preferably has a transmittance of greater than 58% for light in the wavelength range of 700 to 1100 nm, and the high infrared transmittance adhesive film layer preferably has a transmittance of less than 1% for light in the wavelength range of 400 to 700 nm, thereby contributing to further improving the utilization rate of the sealing adhesive film for light in the near-infrared wavelength range and reducing light pollution as much as possible.

[0023] The high infrared reflectance adhesive film layer preferably has a reflectance of more than 85% for light in the wavelength range of 700 to 1100 nm, thereby contributing to improving the overall utilization rate of the sealing adhesive film for light in the wavelength range of 700 to 1100 nm.

[0024] In one embodiment of the present application, the sealing adhesive film has a reflectance of more than 70% for light in the wavelength range of 700 to 1100 nm.

[0025] The sealing adhesive film having the above reflectance performance is advantageous by improving the light conversion efficiency of the photovoltaic assembly.

[0026] In one embodiment of the present application, the high infrared transmittance adhesive film layer contains a pigment, and the pigment is one or more selected from fullerene and its derivatives, direct fast dyes, direct diazo dyes, direct cross dyes, and complex metal-containing azo dyes. In terms of parts by weight, the high infrared transmittance adhesive film layer contains 100 parts of a first olefin resin, 0.01 to 10 parts of a pigment, 0.01 to 0.1 parts of a first coupling agent, 0.01 to 0.3 parts of a first crosslinking agent, and 0.01 to 0.3 parts of a first crosslinking aid, and the pigment is preferably 0.01 to 0.03 parts. Preferably, the pigment is one or more selected from Direct Black 144, Metal Complex Dye X55, Azo Pigment B27, Aniline Black No. 2, Perylene Black LP32, Perylene Black L0086, BASF Orasol Black X51, and BASF Paliotol Black L0080, and the first olefin resin is one or more selected from ethylene-vinyl acetate ester, ethylene-octene copolymer, ethylene-α-olefin copolymer, ethylene-methyl methacrylate copolymer, ethylene-methacrylic acid ionomer, and metallocene-catalyzed ethylene butene copolymer. Preferably, the first coupling agent is any one or more selected from vinyltriethoxysilane, vinyltrimethoxysilane, vinyltri(β-methoxyethoxy)silane, methacryloyloxypropyltrimethoxysilane, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, and aminopropyltriisopropoxysilane, and preferably, the first crosslinking agent is tert-butylperoxyisopropylcarbonate, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 1-bis(tert-peroxybutyl)-3,3,5-trimethylcyclohexane, tert-butylperoxy 2-ethylhexylcarbonate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-pentylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-pentylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, tert-amyl peroxycarbonate, t-butylperoxy-3,5,5-trimethylhexanoate, one or more selected from the group consisting of a mixture of a plurality of types in any ratio, and preferably, the first crosslinking aid is trimethallyl isocyanurate, triallyl isocyanurate, triallyl cyanurate, divinylbenzene, diisopropenylbenzene, diallyl phthalate, allyl acrylate, allyl methacrylate, diallyl maleate, diallyl phthalate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated pentaerythritol tetraacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated ... The silyl glyceryl triacrylate, propoxylated glyceryl triacrylate, trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane trimethacrylate, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, polyethylene glycol (200) diacrylate, polyethylene glycol (400) diacrylate, polyethylene glycol (600) diacrylate, polyethylene glycol (200) dimethacrylate, polyethylene glycol (400) dimethacrylate, polyethylene glycol (600) dimethacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, and neopentyl glycol diacrylate are any one or more selected from the group consisting of silyl glyceryl triacrylate, propoxylated glyceryl triacrylate, trimethylolpropane trimethacrylate, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diethylene glycol dimethacrylate, polyethylene glycol (200) diacrylate, polyethylene glycol (400) diacrylate, polyethylene glycol (600) dimethacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, and neopentyl glycol diacrylate.

[0027] The more pigment is added, the more advantageous it is for the photovoltaic assembly to have a black appearance, but an excessive amount of pigment causes a decrease in the light transmittance of the high infrared transmittance adhesive film layer. In the present application, the content of the pigment in the high infrared transmittance adhesive film layer is preferably set to a black adhesive film, and the transmittance of the high infrared transmittance adhesive film layer for light in the wavelength range of 700 to 1100 nm can be improved, and the conversion of light absorbed by the black film to thermal energy can be reduced as much as possible, thereby reducing the risk of temperature rise in the photovoltaic assembly. The preferred first coupling agent, first crosslinking agent, and first crosslinking assistant agent are advantageous for improving the crosslinking effect of the first olefin resin, and naturally, a person skilled in the art may select other suitable types of first coupling agent, first crosslinking agent, and first crosslinking assistant agent, which will not be described in detail here.

[0028] In one embodiment of the present application, the infrared high reflectance adhesive film layer includes, by weight, 100 parts of a second olefin resin, 5 to 40 parts of a filler, 0.01 to 0.1 parts of a second coupling agent, 0.01 to 0.3 parts of a second crosslinking agent, and 0.01 to 0.3 parts of a second crosslinking aid, the second olefin resin being any one or more selected from ethylene-vinyl acetate ester, ethylene-α-olefin copolymer, ethylene-methyl methacrylate copolymer, ethylene-methacrylic acid ionomer, and metallocene-catalyzed ethylene butene copolymer, the filler being any one or more selected from titanium white, talcum powder, silica, aluminum hydroxide, magnesium hydroxide, alumina, boehmite, mica, kaolin, calcium carbonate, wollastonite, aluminum nitride, and boron nitride, and the particle size of the filler is 0.4 to 2.0 μm, preferably 0.7 to 2.0 μm. Preferably, the second coupling agent is any one or more selected from vinyltriethoxysilane, vinyltrimethoxysilane, vinyltri(β-methoxyethoxy)silane, methacryloyloxypropyltrimethoxysilane, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, and aminopropyltriisopropoxysilane, and preferably, the second crosslinking agent is tert-butylperoxyisopropylcarbonate, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 1- Bis(tert-peroxybutyl)-3,3,5-trimethylcyclohexane, tert-butylperoxy 2-ethylhexyl carbonate, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-pentylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(tert-pentylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, tert-amylperoxycarbonate, t-butylperoxy-3,5,5-trimethylhexanoate, or a mixture of a plurality of types in any ratio, and preferably, the second crosslinking coagent is trimethallyl isocyanurate, triallyl isocyanurate, triallyl cyanurate, divinylbenzene, diisopropenylbenzene, diallyl phthalate, allyl acrylate, allyl methacrylate, diallyl maleate, diallyl phthalate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, propoxylated pentaerythritol tetraacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, ethoxylated glyceryl triacrylate, propoxylated glyceryl The monomer unit may be any one or more selected from the group consisting of triacrylate, trimethylolpropane trimethacrylate, ethoxylated trimethylolpropane trimethacrylate, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, polyethylene glycol (200) diacrylate, polyethylene glycol (400) diacrylate, polyethylene glycol (600) diacrylate, polyethylene glycol (200) dimethacrylate, polyethylene glycol (400) dimethacrylate, polyethylene glycol (600) dimethacrylate, ethoxylated bisphenol A diacrylate, ethoxylated bisphenol A dimethacrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate, and neopentyl glycol diacrylate.

[0029] The filler in the high infrared reflectance adhesive film layer of the present application makes the high infrared reflectance adhesive film layer a white adhesive film, which is advantageous for improving the reflectance of the sealing adhesive film to the irradiated light. Since titanium dioxide with a large particle size has a higher near-infrared reflectance, titanium dioxide within the above preferred particle size range has a higher near-infrared reflectance. Addition of an excess filler causes the filler to accumulate, reducing the effective specific surface area that acts to reflect sunlight, and accordingly reducing the overall reflectance of the sealing adhesive film, so that a filler of 5 to 15 parts is preferably more advantageous for improving the reflectance of the sealing adhesive film to the irradiated light. The preferred second coupling agent, second crosslinking agent, and second crosslinking assistant agent are advantageous for improving the crosslinking effect of the second olefin resin, and naturally, a person skilled in the art may select other appropriate types of second coupling agent, second crosslinking agent, and second crosslinking assistant agent, which will not be described in detail here.

[0030] The thickness of the high infrared transmittance adhesive film layer affects the transmittance of the irradiated light to some extent. The thickness of the high infrared transmittance adhesive film layer is 80 to 300 μm, which is advantageous for improving the overall transmittance of the high infrared transmittance adhesive film layer for light in the wavelength range of 700 to 1100 nm. The high infrared transmittance adhesive film layer is preferably a pre-crosslinked film, and the pre-crosslinking degree of the high infrared transmittance adhesive film layer is preferably 5 to 50%. This contributes to avoiding the risk of the high infrared transmittance adhesive film layer migrating to the front side of the battery, which is advantageous for ensuring a good laminated appearance of the photovoltaic assembly and avoiding unnecessary loss of front power of the photovoltaic assembly. When there is no risk of the high infrared transmittance adhesive film layer migrating upward, the lower the pre-crosslinking degree of the high infrared transmittance adhesive film layer, the more advantageous it is for reducing or avoiding the phenomenon of cracking or cracking of the battery.

[0031] The thickness of the infrared high reflectance adhesive film layer is preferably 120-500 μm, which is advantageous for improving the overall reflectance of the infrared high reflectance adhesive film layer for light in the wavelength range of 700-1100 nm. The infrared high reflectance adhesive film layer is preferably a pre-crosslinked film, and the pre-crosslinking degree of the infrared high reflectance adhesive film layer is preferably 10-70%. This is advantageous for avoiding the risk of the infrared high reflectance adhesive film layer migrating to the front surface of the cell due to the flow of the infrared high reflectance adhesive film layer, ensuring good laminated appearance of the photovoltaic assembly, and avoiding unnecessary loss of front power of the photovoltaic assembly.

[0032] Preferably, the pre-crosslinking degree of the high infrared transmittance adhesive film layer is lower than that of the high infrared reflectance adhesive film layer, which is more conducive to achieving both good appearance of the photovoltaic assembly and the integrity of the cell.

[0033] In another exemplary embodiment of the present application, a photovoltaic assembly is provided that includes a front transparent encapsulating layer, a first sealing adhesive film layer, a cell sheet array, a second sealing adhesive film layer, and a back encapsulating layer, wherein the second sealing adhesive film layer is the sealing adhesive film described above.

[0034] Using the above-mentioned sealing adhesive film as the second sealing adhesive film layer on the back surface of the cell sheet array maximizes the use of sunlight and improves the overall photoelectric conversion efficiency of the solar cell module, thereby improving the efficiency and lifespan of the solar cell.

[0035] Preferably, the high infrared transmittance adhesive film layer of the sealing adhesive film is provided in contact with the cell sheet of the photovoltaic assembly. A part of the sunlight irradiated to the sealing adhesive film is absorbed by the cell sheet through the high infrared transmittance adhesive film layer, and another part of the sunlight is reflected by the high infrared reflectance adhesive film layer, and the reflected light is secondarily reflected to the sealing adhesive film through the inner surface of the back plate, and then passes through the high infrared transmittance adhesive film layer to reach the cell sheet. In this way, the overall reflectance of the sealing adhesive film is improved, and therefore the overall photoelectric conversion efficiency of the photovoltaic assembly is increased.

[0036] The beneficial effects of the present invention will be described below with reference to specific examples and comparative examples.

[0037] Example 1 Formulation of high infrared transmittance adhesive film layer E1-1: 100 parts ethylene-octene copolymer, 0.01 parts azo pigment B27, 0.01 parts vinyltrimethoxysilane, 0.01 parts tert-butylperoxyisopropylcarbonate, 0.01 parts propoxylated pentaerythritol tetraacrylate.

[0038] Formulation of infrared high reflectance adhesive film layer E1-2: 100 parts of ethylene-vinyl acetate ester, 5 parts of titanium white (particle size is 1 μm), 0.01 parts of vinyltrimethoxysilane, 0.01 parts of tert-butylperoxyisopropyl carbonate, 0.01 parts of propoxylated pentaerythritol tetraacrylate.

[0039] E1-1 and E1-2 were multi-layer co-extruded to prepare a two-layer photovoltaic sealing adhesive film, designated as E1. The thickness of the obtained sealing adhesive film of the high infrared transmittance adhesive film layer E1-1 was 0.2 mm, and the thickness of the high infrared reflectance adhesive film layer E1-2 was 0.3 mm, where the preliminary crosslinking degree of the high infrared transmittance adhesive film layer E1-1 was 10%, and the preliminary crosslinking degree of the high infrared reflectance adhesive film layer E1-2 was 15%.

[0040] Example 2 Compared with the first embodiment, the second embodiment differs in the following points.

[0041] Formulation of high infrared transmittance adhesive film layer E2-1: 100 parts ethylene-octene copolymer, 0.03 parts azo pigment B27, 0.01 parts vinyltrimethoxysilane, 0.01 parts tert-butylperoxyisopropylcarbonate, 0.01 parts propoxylated pentaerythritol tetraacrylate.

[0042] Formulation of infrared high reflectance adhesive film layer E2-2: 100 parts of ethylene-vinyl acetate ester, 5 parts of titanium white (particle size is 1 μm), 0.01 parts of vinyltrimethoxysilane, 0.01 parts of tert-butylperoxyisopropyl carbonate, 0.01 parts of propoxylated pentaerythritol tetraacrylate.

[0043] E2-1 and E2-2 were multi-layer co-extruded to prepare a two-layer photovoltaic sealing adhesive film, designated as E2. The thickness of the obtained sealing adhesive film of the high infrared transmittance adhesive film layer E2-1 was 0.2 mm, and the thickness of the high infrared reflectance adhesive film layer E2-2 was 0.3 mm, where the preliminary crosslinking degree of the high infrared transmittance adhesive film layer E2-1 was 10%, and the preliminary crosslinking degree of the high infrared reflectance adhesive film layer E2-2 was 15%.

[0044] Example 3 Compared with the first embodiment, the third embodiment differs in the following points.

[0045] Formulation of high infrared transmittance adhesive film layer E3-1: 100 parts ethylene-octene copolymer, 10 parts azo pigment B27, 0.01 parts vinyltrimethoxysilane, 0.01 parts tert-butylperoxyisopropylcarbonate, 0.01 parts propoxylated pentaerythritol tetraacrylate.

[0046] Formulation of infrared high reflectance adhesive film layer E3-2: 100 parts of ethylene-vinyl acetate ester, 5 parts of titanium white (particle size is 1 μm), 0.01 parts of vinyltrimethoxysilane, 0.01 parts of tert-butylperoxyisopropyl carbonate, 0.01 parts of propoxylated pentaerythritol tetraacrylate.

[0047] E3-1 and E3-2 were multi-layer co-extruded to prepare a two-layer photovoltaic sealing adhesive film, designated as E3. The thickness of the infrared ray high transmittance film E3-1 layer of the obtained sealing adhesive film was 0.2 mm, and the thickness of the infrared ray high reflectance adhesive film layer E3-2 was 0.3 mm, where the preliminary crosslinking degree of the infrared ray high transmittance adhesive film layer E3-1 was 10%, and the preliminary crosslinking degree of the infrared ray high reflectance adhesive film layer E3-2 was 15%.

[0048] Example 4 Compared with the first embodiment, the fourth embodiment differs in the following points.

[0049] Formulation of infrared high transmittance adhesive film layer E4-1: 100 parts ethylene-octene copolymer, 0.01 parts perylene black L0086, 0.01 parts vinyltrimethoxysilane, 0.01 parts tert-butylperoxyisopropylcarbonate, 0.01 parts propoxylated pentaerythritol tetraacrylate.

[0050] Formulation of infrared high reflectance adhesive film layer E4-2: 100 parts of ethylene-vinyl acetate ester, 5 parts of titanium white (particle size is 1 μm), 0.01 parts of vinyltrimethoxysilane, 0.01 parts of tert-butylperoxyisopropyl carbonate, 0.01 parts of propoxylated pentaerythritol tetraacrylate.

[0051] E4-1 and E4-2 were multi-layer co-extruded to prepare a two-layer photovoltaic sealing adhesive film, designated as E4. The thickness of the obtained sealing adhesive film of the high infrared transmittance adhesive film layer E4-1 was 0.2 mm, and the thickness of the high infrared reflectance adhesive film layer E4-2 was 0.3 mm, where the preliminary crosslinking degree of the high infrared transmittance adhesive film layer E4-1 was 10%, and the preliminary crosslinking degree of the high infrared reflectance adhesive film layer E4-2 was 15%.

[0052] Example 5 Compared with the first embodiment, the fifth embodiment differs in the following points.

[0053] Formulation of infrared high transmittance adhesive film layer E5-1: 100 parts ethylene-octene copolymer, 0.01 parts BASF Paliotol Black L0080, 0.01 parts vinyltrimethoxysilane, 0.01 parts tert-butylperoxyisopropylcarbonate, 0.01 parts propoxylated pentaerythritol tetraacrylate.

[0054] Formulation of infrared high reflectance adhesive film layer E5-2: 100 parts of ethylene-vinyl acetate ester, 5 parts of titanium white (particle size is 1 μm), 0.01 parts of vinyltrimethoxysilane, 0.01 parts of tert-butylperoxyisopropyl carbonate, 0.01 parts of propoxylated pentaerythritol tetraacrylate.

[0055] E5-1 and E5-2 were multi-layer co-extruded to prepare a two-layer photovoltaic sealing adhesive film, designated as E5. The thickness of the obtained sealing adhesive film of the high infrared transmittance adhesive film layer E5-1 was 0.2 mm, and the thickness of the high infrared reflectance adhesive film layer E5-2 was 0.3 mm, where the preliminary crosslinking degree of the high infrared transmittance adhesive film layer E5-1 was 10%, and the preliminary crosslinking degree of the high infrared reflectance adhesive film layer E5-2 was 15%.

[0056] Example 6 Compared with the first embodiment, the sixth embodiment differs in the following points.

[0057] Formulation of high infrared transmittance adhesive film layer E6-1: 100 parts ethylene-octene copolymer, 5 parts azo pigment B27, 0.05 parts vinyltrimethoxysilane, 0.2 parts tert-butylperoxyisopropylcarbonate, 0.2 parts propoxylated pentaerythritol tetraacrylate.

[0058] Formulation of infrared high reflectance adhesive film layer E6-2: 100 parts of ethylene-vinyl acetate ester, 25 parts of titanium white (particle size is 1 μm), 0.05 parts of vinyltrimethoxysilane, 0.2 parts of tert-butylperoxyisopropyl carbonate, 0.2 parts of propoxylated pentaerythritol tetraacrylate.

[0059] E6-1 and E6-2 were multi-layer co-extruded to prepare a two-layer photovoltaic sealing adhesive film, designated as E6. The thickness of the obtained sealing adhesive film of the high infrared transmittance adhesive film layer E6-1 was 0.2 mm, and the thickness of the high infrared reflectance adhesive film layer E6-2 was 0.3 mm, where the preliminary crosslinking degree of the high infrared transmittance adhesive film layer E6-1 was 20%, and the preliminary crosslinking degree of the high infrared reflectance adhesive film layer E6-2 was 40%.

[0060] Example 7 Compared with the first embodiment, the seventh embodiment differs in the following points.

[0061] Formulation of infrared high transmittance film E7-1 layer: 100 parts ethylene-octene copolymer, 10 parts azo pigment B27, 0.1 parts vinyltrimethoxysilane, 0.3 parts tert-butylperoxyisopropylcarbonate, 0.8 parts propoxylated pentaerythritol tetraacrylate.

[0062] Formulation of infrared high reflectance adhesive film layer E7-2: 100 parts of ethylene-vinyl acetate ester, 40 parts of titanium white (particle size is 1 μm), 0.1 parts of vinyltrimethoxysilane, 0.3 parts of tert-butylperoxyisopropyl carbonate, 0.3 parts of propoxylated pentaerythritol tetraacrylate.

[0063] E7-1 and E7-2 were multi-layer co-extruded to prepare a two-layer photovoltaic sealing adhesive film, designated as E7. The thickness of the obtained sealing adhesive film of the high infrared transmittance adhesive film layer E7-1 was 0.2 mm, and the thickness of the high infrared reflectance adhesive film layer E7-2 was 0.3 mm, where the preliminary crosslinking degree of the high infrared transmittance adhesive film layer E7-1 was 50%, and the preliminary crosslinking degree of the high infrared reflectance adhesive film layer E7-2 was 50%.

[0064] Example 8 Compared with the first embodiment, the eighth embodiment differs in the following points.

[0065] Formulation of infrared high transmittance adhesive film layer E8-1: 100 parts ethylene-alpha olefin copolymer, 0.01 parts azo pigment B27, 0.1 parts methacryloyloxypropyltrimethoxysilane, 0.3 parts 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 0.3 parts ethoxylated glyceryl triacrylate.

[0066] Formulation of infrared high reflectance adhesive film layer E8-2: 100 parts of ethylene-methacrylic acid ionomer, 40 parts of alumina (particle size is 1 μm), 0.1 parts of vinyltri(β-methoxyethoxy)silane, 0.3 parts of 2,2-bis(tert-butylperoxy)butane, 0.3 parts of polyethylene glycol (200) diacrylate.

[0067] E8-1 and E8-2 were multi-layer co-extruded to produce a two-layer photovoltaic sealing adhesive film, designated as E8. The thickness of the obtained sealing adhesive film of the high infrared transmittance adhesive film layer E8-1 was 0.2 mm, the thickness of the high infrared reflectance adhesive film layer E8-2 was 0.3 mm, the preliminary crosslinking degree of the high infrared transmittance adhesive film layer E8-1 was 10%, and the preliminary crosslinking degree of the high infrared reflectance adhesive film layer E8-2 was 15%.

[0068] Example 9 Compared with Example 1, Example 9 differs in the following points.

[0069] Formulation of high infrared transmittance adhesive film layer E9-1: 100 parts ethylene-octene copolymer, 0.01 parts azo pigment B27, 0.01 parts vinyltrimethoxysilane, 0.01 parts tert-butylperoxyisopropylcarbonate, 0.01 parts propoxylated pentaerythritol tetraacrylate.

[0070] Formulation of infrared high reflectance adhesive film layer E9-2: 100 parts of ethylene-vinyl acetate ester, 5 parts of titanium white (particle size is 0.7 μm), 0.01 parts of vinyltrimethoxysilane, 0.01 parts of tert-butylperoxyisopropyl carbonate, 0.01 parts of propoxylated pentaerythritol tetraacrylate.

[0071] E9-1 and E9-2 were multi-layer co-extruded to prepare a two-layer photovoltaic sealing adhesive film, designated as E9. The thickness of the obtained sealing adhesive film of the high infrared transmittance adhesive film layer E9-1 was 0.2 mm, and the thickness of the high infrared reflectance adhesive film layer E9-2 was 0.3 mm, where the preliminary crosslinking degree of the high infrared transmittance adhesive film layer E9-1 was 10%, and the preliminary crosslinking degree of the high infrared reflectance adhesive film layer E9-2 was 15%.

[0072] Example 10 Compared with the first embodiment, the tenth embodiment differs in the following points.

[0073] Formulation of high infrared transmittance adhesive film layer E10-1: 100 parts ethylene-octene copolymer, 0.01 parts azo pigment B27, 0.01 parts vinyltrimethoxysilane, 0.01 parts tert-butylperoxyisopropylcarbonate, 0.01 parts propoxylated pentaerythritol tetraacrylate.

[0074] Formulation of infrared high reflectance adhesive film layer E10-2: 100 parts of ethylene-vinyl acetate ester, 5 parts of titanium white (particle size is 0.4 μm), 0.01 parts of vinyltrimethoxysilane, 0.01 parts of tert-butylperoxyisopropyl carbonate, 0.01 parts of propoxylated pentaerythritol tetraacrylate.

[0075] E10-1 and E10-2 were multi-layer co-extruded to prepare a two-layer photovoltaic sealing adhesive film, designated as E10. The thickness of the obtained sealing adhesive film of the high infrared transmittance adhesive film layer E10-1 was 0.2 mm, and the thickness of the high infrared reflectance adhesive film layer E10-2 was 0.3 mm, where the preliminary crosslinking degree of the high infrared transmittance adhesive film layer E10-1 was 10%, and the preliminary crosslinking degree of the high infrared reflectance adhesive film layer E10-2 was 15%.

[0076] Example 11 Compared with Example 1, Example 11 differs in the following points.

[0077] Formulation of high infrared transmittance adhesive film layer E11-1: 100 parts ethylene-octene copolymer, 0.01 parts azo pigment B27, 0.01 parts vinyltrimethoxysilane, 0.01 parts tert-butylperoxyisopropylcarbonate, 0.01 parts propoxylated pentaerythritol tetraacrylate.

[0078] Formulation of infrared high reflectance adhesive film layer E11-2: 100 parts of ethylene-vinyl acetate ester, 5 parts of titanium white (particle size is 2 μm), 0.01 parts of vinyltrimethoxysilane, 0.01 parts of tert-butylperoxyisopropyl carbonate, 0.01 parts of propoxylated pentaerythritol tetraacrylate.

[0079] E11-1 and E11-2 were multi-layer co-extruded to prepare a two-layer photovoltaic sealing adhesive film, designated as E11. In the obtained sealing adhesive film, the thickness of the high infrared transmittance adhesive film layer E11-1 was 0.2 mm, and the thickness of the high infrared reflectance adhesive film layer E11-2 was 0.3 mm, where the preliminary crosslinking degree of the high infrared transmittance adhesive film layer E11-1 was 10%, and the preliminary crosslinking degree of the high infrared reflectance adhesive film layer E11-2 was 15%.

[0080] Example 12 Compared with Example 1, Example 12 differs in the following points.

[0081] Formulation of high infrared transmittance adhesive film layer E12-1: 100 parts ethylene-octene copolymer, 0.01 parts azo pigment B27, 0.01 parts vinyltrimethoxysilane, 0.01 parts tert-butylperoxyisopropylcarbonate, 0.01 parts propoxylated pentaerythritol tetraacrylate.

[0082] Formulation of infrared high reflectance adhesive film layer E12-2: 100 parts of ethylene-vinyl acetate ester, 5 parts of titanium white (particle size is 1 μm), 0.01 parts of vinyltrimethoxysilane, 0.01 parts of tert-butylperoxyisopropyl carbonate, 0.01 parts of propoxylated pentaerythritol tetraacrylate.

[0083] E12-1 and E12-2 were multi-layer co-extruded to prepare a two-layer photovoltaic sealing adhesive film, designated as E12. The thickness of the obtained sealing adhesive film of the high infrared transmittance adhesive film layer E12-1 was 0.08 mm, and the thickness of the high infrared reflectance adhesive film layer E12-2 was 0.12 mm, where the preliminary crosslinking degree of the high infrared transmittance adhesive film layer E12-1 was 10%, and the preliminary crosslinking degree of the high infrared reflectance adhesive film layer E12-2 was 15%.

[0084] Example 13 Compared with Example 1, Example 13 differs in the following points.

[0085] Formulation of high infrared transmittance adhesive film layer E13-1: 100 parts ethylene-octene copolymer, 0.01 parts azo pigment B27, 0.01 parts vinyltrimethoxysilane, 0.01 parts tert-butylperoxyisopropylcarbonate, 0.01 parts propoxylated pentaerythritol tetraacrylate.

[0086] Formulation of infrared high reflectance adhesive film layer E13-2: 100 parts of ethylene-vinyl acetate ester, 5 parts of titanium white (particle size is 1 μm), 0.01 parts of vinyltrimethoxysilane, 0.01 parts of tert-butylperoxyisopropyl carbonate, 0.01 parts of propoxylated pentaerythritol tetraacrylate.

[0087] E13-1 and E13-2 were multi-layer co-extruded to prepare a two-layer photovoltaic sealing adhesive film, designated as E13. The thickness of the obtained sealing adhesive film of the high infrared transmittance adhesive film layer E13-1 was 0.3 mm, and the thickness of the high infrared reflectance adhesive film layer E13-2 was 0.5 mm, where the preliminary crosslinking degree of the high infrared transmittance adhesive film layer E13-1 was 10%, and the preliminary crosslinking degree of the high infrared reflectance adhesive film layer E13-2 was 15%.

[0088] Example 14 Compared with Example 1, Example 14 differs in the following points.

[0089] Formulation of infrared high transmittance adhesive film layer E14-1: 100 parts ethylene-vinyl acetate ester, 0.01 parts azo pigment B27, 0.01 parts vinyltrimethoxysilane, 0.01 parts tert-butylperoxyisopropylcarbonate, 0.01 parts propoxylated pentaerythritol tetraacrylate.

[0090] Formulation of infrared high reflectance adhesive film layer E14-2: 100 parts of ethylene-vinyl acetate ester, 5 parts of titanium white (particle size is 1 μm), 0.01 parts of vinyltrimethoxysilane, 0.01 parts of tert-butylperoxyisopropyl carbonate, 0.01 parts of propoxylated pentaerythritol tetraacrylate.

[0091] E14-1 and E14-2 were multi-layer co-extruded to prepare a two-layer photovoltaic sealing adhesive film, designated as E14. The thickness of the obtained sealing adhesive film of the high infrared transmittance adhesive film layer E14-1 was 0.2 mm, and the thickness of the high infrared reflectance adhesive film layer E14-2 was 0.3 mm, where the preliminary crosslinking degree of the high infrared transmittance adhesive film layer E14-1 was 10%, and the preliminary crosslinking degree of the high infrared reflectance adhesive film layer E14-2 was 15%.

[0092] Photovoltaic assembly: tempered glass, a normal transparent sealing adhesive film, a crystalline silicon cell sheet, sealing adhesive films E1 to E14 (the high infrared transmittance adhesive film layers E1-1 to E14-1 of the sealing adhesive films E1 to E14 are provided in contact with the crystalline silicon cell sheet, respectively), and a transparent back plate were arranged in order from the top, and laminated at 145°C with a laminator to obtain corresponding black photovoltaic assemblies PV-1 to PV-14.

[0093] Comparative Example 1: Tempered glass, a normal transparent sealing adhesive film, a crystalline silicon cell sheet, a normal transparent EVA sealing adhesive film F806PS, and a black backplate BEC306HB were arranged from the top in this order, and laminated at 145°C with a laminator to obtain a corresponding black photovoltaic assembly PV-D1.

[0094] The transmittance and reflectance of the high infrared transmittance adhesive film layers E1-1 to E14-1, high infrared reflectance adhesive film layers E1-2 to E14-2, and sealing adhesive films E1 to E14 obtained in accordance with Examples 1 to 14 above were tested, and the test results are shown in Table 1.

[0095] How we tested Transmittance test: The test was carried out according to the GB / T 2410-2008 standard, and the transmittance of the infrared high transmittance adhesive film layers E1-1 to E14-1 was measured by a UV-Vis spectrophotometer.

[0096] Reflectance test: The test was carried out according to the GB / T 29848 standard, and the reflectance of the infrared high reflectance adhesive film layers E1-2 to E14-2 and the sealing adhesive films E1 to E14 was measured by an ultraviolet-visible spectrophotometer. [Table 1]

[0097] As can be seen from the data in Table 1, compared with Example 1, in Examples 6 and 7, the addition of excess titanium white caused titanium white to accumulate, which reduced the effective specific surface area that acts to reflect sunlight, and ultimately reduced the overall reflectance of the sealing adhesive film to a certain extent.

[0098] Compared with Example 1, in Examples 6 and 7, the amount of azo pigment B27 added was too large, which resulted in a decrease in the transmittance of the high infrared transmittance adhesive film layer to sunlight.

[0099] In Example 8, changing the amount and type of crosslinking agent and crosslinking assistant used also has a significant effect on the transmittance of the high infrared transmittance adhesive film layer to sunlight, and the reflectance of the high infrared transmittance adhesive film layer and the sealing adhesive film to sunlight.

[0100] PID test of photovoltaic assembly: The front adhesive film is all F406PS transparent adhesive film, and all P-type double-sided cells from manufacturer A are used. The PID test of the photovoltaic module is performed according to IEC TS2804-1:2015, and the test conditions are 85℃, 85%RH, and a constant DC voltage of -1500V. After 192h, the power decay of the photovoltaic module is measured before and after the PID test, and the test results are shown in Table 2. [Table 2]

[0101] As can be seen from the above description, the above embodiments of the present invention achieve the following technical advantages.

[0102] The high infrared transmittance adhesive film layer of the sealing adhesive film provided by the present application has a transmittance of more than 55% for light in the wavelength range of 700-1100 nm and a transmittance of less than 2% for light in the wavelength range of 400-700 nm, and the high infrared reflectance adhesive film layer has a reflectance of more than 75% for light in the wavelength range of 700-1100 nm. Thus, when the sealing adhesive film is used as the sealing adhesive film on the back side of the cell sheet, it not only realizes the black appearance of the photovoltaic power generation module and reduces light pollution, but also maximizes the use of sunlight and improves the overall photoelectric conversion efficiency of the photovoltaic power generation module, thereby improving the efficiency and life of the solar cell. Furthermore, when the sealing adhesive film is used for BIPV building integration, it is possible to achieve both the aesthetic appearance of the building and the efficiency of the photovoltaic power generation module.

[0103] It is clear from the PID comparison test that the sealing adhesive film provided by the present application uses inorganic filler in the infrared reflective adhesive film layer, which is advantageous in improving the PID resistance of the P-type bifacial photovoltaic assembly. In particular, when pure titanium white filler is used in the infrared reflective adhesive film layer, the infrared reflective adhesive film layer has a significantly improved PID resistance compared to ordinary transparent films. It is expected that this is related to the electronegativity of titanium white, or that titanium white has the function of retarding the penetration of sodium ions into the sealing adhesive film.

[0104] The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and the present invention may have various modifications and variations for those skilled in the art. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the scope of protection of the present invention.

Claims

1. An adhesive film for sealing, A sealing adhesive film comprising: a high infrared transmittance adhesive film layer; and a high infrared reflectance adhesive film layer laminated on the high infrared transmittance adhesive film layer, wherein the high infrared transmittance adhesive film layer has a transmittance of more than 55% for light in the wavelength range of 700 nm to 1100 nm and a transmittance of less than 2% for light in the wavelength range of 400 nm to 700 nm, and the high infrared reflectance adhesive film layer has a reflectance of more than 75% for light in the wavelength range of 700 nm to 1100 nm.

2. The high infrared transmittance adhesive film layer has a transmittance of more than 58% for light in the wavelength range of 700 nm to 1100 nm and a transmittance of less than 1% for light in the wavelength range of 400 nm to 700 nm. The sealing adhesive film according to claim 1.

3. The adhesive film for sealing according to claim 1, wherein the adhesive film layer with high infrared reflectance has a reflectance of more than 85% for light in a wavelength range of 700 nm to 1100 nm.

4. 4. The sealing adhesive film according to claim 1, which has a reflectance of more than 70% for light in the wavelength range of 700 nm to 1100 nm.

5. The infrared ray high transmittance adhesive film layer contains a pigment, and the pigment is any one or more selected from fullerene and its derivatives, direct fast dyes, direct diazo dyes, direct cross dyes, and complex metal-containing azo dyes; The infrared ray high transmittance adhesive film layer includes, by weight, 100 parts of a first olefin resin, 0.01 to 10 parts of a pigment, 0.01 to 0.1 parts of a first coupling agent, 0.01 to 0.3 parts of a first crosslinking agent, and 0.01 to 0.3 parts of a first crosslinking assistant; The first olefin-based resin is any one or more selected from ethylene-vinyl acetate ester, ethylene-octene copolymer, ethylene-α-olefin copolymer, ethylene-methyl methacrylate copolymer, ethylene-methacrylic acid ionomer, and metallocene-catalyzed ethylene-butene copolymer. The sealing adhesive film according to any one of claims 1 to 3.

6. The infrared high reflectance adhesive film layer includes, by weight, 100 parts of a second olefin resin, 5 to 40 parts of a filler, 0.01 to 0.1 parts of a second coupling agent, 0.01 to 0.3 parts of a second crosslinking agent, and 0.01 to 0.3 parts of a second crosslinking assistant; The second olefin-based resin is at least one selected from the group consisting of ethylene-vinyl acetate ester, ethylene-α-olefin copolymer, ethylene-methyl methacrylate copolymer, ethylene-methacrylic acid ionomer, and metallocene-catalyzed ethylene butene copolymer; The sealing adhesive film according to any one of claims 1 to 3, characterized in that the filler is one or more selected from the group consisting of titanium white, talcum powder, silica, aluminum hydroxide, magnesium hydroxide, alumina, boehmite, mica, kaolin, calcium carbonate, wollastonite, aluminum nitride, and boron nitride, and the particle size of the filler is 0.4 μm to 2.0 μm.

7. The adhesive film for sealing according to any one of claims 1 to 3, characterized in that the thickness of the high infrared transmittance adhesive film layer is 80 μm to 300 μm, and the high infrared transmittance adhesive film layer is a pre-crosslinked film having a pre-crosslinking degree of 5% to 50%.

8. The adhesive film for sealing according to any one of claims 1 to 3, characterized in that the thickness of the adhesive film layer with high infrared reflectivity is 120 μm to 500 μm, and the adhesive film layer with high infrared reflectivity is a pre-crosslinked film having a degree of pre-crosslinking of 10% to 70%.

9. A photovoltaic assembly comprising a front transparent encapsulation layer, a first encapsulating adhesive film layer, a cell sheet array, a second encapsulating adhesive film layer, and a back encapsulation layer, A photovoltaic assembly, characterized in that the second sealing adhesive film layer is the sealing adhesive film according to any one of claims 1 to 8.

10. 10. The photovoltaic assembly of claim 9, wherein the high infrared transmittance adhesive film layer of the sealing adhesive film is provided in contact with a cell sheet of the photovoltaic assembly.

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