Cut-off adhesive film and photovoltaic module

Abstract

The invention provides a cut-off adhesive film and a photovoltaic module. The light transmittance of the cut-off adhesive film at the wave band of 250-300 nm is 0.5-35%, the light transmittance of the cut-off adhesive film at the wave band of 280-320 nm is 0-10%, and the light transmittance of the cut-off adhesive film at the wave band of 300-320 nm is 0-10%. The full-wave-band ultraviolet cut-off adhesive film can prevent harmful ultraviolet radiation and also can prevent part of beneficial ultraviolet light from entering the solar cell panel unnecessarily. Compared with the prior art, the cut-off adhesive film not only can accurately control the cut-off three ultraviolet bands, so that the cut-off adhesive film more effectively protects the battery from being influenced by specific short-wave ultraviolet light, but also allows ultraviolet light with other wavelengths to continuously provide power benefits for the battery. According to the cut-off adhesive film, the initial power of the photovoltaic module can be improved, the power output stability of the photovoltaic module can be maintained, the performance degradation of the photovoltaic module is reduced, and the service life of the photovoltaic module is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of adhesive films, and in particular to a cut-off adhesive film and a photovoltaic module. Background Art

[0002] After the upgrade of photovoltaic cells from PERC (Passivated Emitter and Rear Cell) to TOPCon (Tunnel Oxide Passivated Contact) and HJT (Homojunction Solar Cell), the cells are becoming more and more sensitive to ultraviolet light. In order to protect the cells, this part of ultraviolet light needs to be cut off or converted into light through a photoconversion film.

[0003] The cost of photoconversion film is high, while the cost of cut-off film is relatively low. Currently, most cut-off films directly absorb the ultraviolet region without any discrimination, without rationally regulating the ultraviolet region, and generally absorb the band of 200 to 380 nm. However, with the demand for ultraviolet light in the cell, it is necessary to absorb specific short-wavelength bands in the ultraviolet region, and the average transmittance of the corresponding band is required. Its advantage is that the cell is sensitive to special ultraviolet bands, and its disadvantage is that it is easy to cause power attenuation, but ultraviolet rays in other bands can still provide power benefits for the cell. This makes the initial power of the ultraviolet short-wave cut-off film module higher than that of the conventional full-band ultraviolet cut-off film module, and the attenuation of the module battery is not much different. Summary of the Invention

[0004] The main purpose of the present invention is to provide a cut-off film and a photovoltaic module to solve the problem of high initial power attenuation of conventional full-band UV cut-off film module batteries in the prior art.

[0005] To achieve the above objectives, according to one aspect of the present invention, a cut-off film is provided, wherein the light transmittance of the cut-off film in the 250-300nm band is 0.5-35%, the light transmittance in the 280-320nm band is 0-10%, and the light transmittance in the 300-320nm band is 0-10%.

[0006] Furthermore, the cut-off film is a three-layer cut-off film, which includes a first cut-off film layer, a second cut-off film layer and a third cut-off film layer sequentially stacked along the thickness direction of the cut-off film, the first cut-off film layer includes 0 to 0.9 parts by weight of a first ultraviolet cut-off agent, preferably 0.1 to 0.9 parts, the second cut-off film layer includes 0.3 to 3 parts by weight of a second ultraviolet cut-off agent, preferably 0.3 to 2.4 parts, and the third cut-off film layer includes 0 to 0.9 parts by weight of a third ultraviolet cut-off agent, preferably 0.1 to 0.9 parts; wherein, the first ultraviolet cut-off agent Selected from 2-cyano-3,3-diphenylacrylate, 2,4-dihydroxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, N,N'-bis(4-ethoxyformylphenyl)-N-benzylformamidine, 2,2'-methylenebis(4-tert-octyl-6-benzotriazolephenol), 4-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-ethylhexyl 3-diphenylacrylate, tetraethyl 2,2'-(1,4-benzenedimethylene)dimalonate, 2-ethylhexyl salicylate, N-(2-ethoxyphenyl)-N'-(2-ethyl)-benzophenone Any one or more of salicylic acid isooctyl salicylate, N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, salicylic acid, methyl salicylate, ethylhexyl-3 (4-methoxyphenyl)-acrylate, salicylic acid-4-tert-butylphenyl ester, trimethylcyclohexyl salicylic acid, and cinnamic acid UV cut-off agents; the second UV cut-off agent is selected from salicylic acid isooctyl ester, N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, salicylic acid, methyl salicylate, ethylhexyl-3 (4-methoxyphenyl)-acrylate, salicylic acid-4-tert-butylphenyl ester, trimethylcyclohexyl salicylic acid, and cinnamic acid UV cut-off agents. The third UV cut-off agent is selected from 3,5-di-tert-butyl-4-hydroxybenzoate, titanium dioxide, zinc oxide, 3-diphenylacrylate, 2-phenyl-5-benzimidazole sulfonic acid, p-aminobenzoic acid and 4-methoxybenzylidene dimethyl malonate, isooctyl salicylate, N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, salicylic acid, methyl salicylate, ethylhexyl-3 (4-methoxyphenyl)-acrylate, 4-tert-butylphenyl salicylate, trimethylcyclohexyl salicylic acid, and any one or more of the cinnamic acid UV cut-off agents.

[0007] Furthermore, the first UV cutoff agent is a combination of 2-cyano-3,3-diphenyl ethyl acrylate and 2,2'-(1,4-phenylenediamine) dimalonic acid tetraethyl ester, and the mass ratio of 2-cyano-3,3-diphenyl ethyl acrylate and 2,2'-(1,4-phenylenediamine) dimalonic acid tetraethyl ester in the first UV cutoff agent is 1 to 2:1 to 2; and / or, the second UV cutoff agent is isooctyl salicylate and N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)- The combination of amides, the mass ratio of isooctyl salicylate and N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide in the second UV cutoff agent is 1 to 5:1 to 5; and / or the third UV cutoff agent is a combination of 3,5-di-tert-butyl-4-hydroxybenzoate and dimethyl 4-methoxybenzylidene malonate, and the mass ratio of 3,5-di-tert-butyl-4-hydroxybenzoate and dimethyl 4-methoxybenzylidene malonate in the third UV cutoff agent is 1 to 2:1 to 3.

[0008] Furthermore, the mass ratio of the first ultraviolet cutoff agent, the second ultraviolet cutoff agent and the third ultraviolet cutoff agent is 0.5-1.5:1-3.5:1-2.

[0009] Furthermore, the light transmittance of the cut-off film in the 250-300 nm band is 0.5-28%, the light transmittance in the 280-320 nm band is 0-7%, and the light transmittance in the 300-320 nm band is 0-5%.

[0010] Furthermore, in parts by weight, the first cut-off film layer, the second cut-off film layer and the third cut-off film layer further independently comprise: 95 to 99.68 parts of a first polymer resin, 0.1 to 1 parts of a first cross-linking agent, 0.1 to 1 parts of a first auxiliary cross-linking agent, 0.1 to 1 parts of a first silane coupling agent; and 0.1 to 1 parts of a first light stabilizer; wherein the first polymer resin is selected from at least one of ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer and ethylene-methyl methacrylate copolymer; and / or the first cross-linking agent is selected from tert-butyl peroxyisopropyl carbonate, 2,5-dimethyl-2,5- At least one of (bis-tert-butylperoxy)hexane, tert-butylperoxycarbonate-2-ethylhexyl ester, 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, tert-amyl peroxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-dimethyl-2,5-dimethyl-2,5-bis(benzoylperoxy)-hexane, tert-amyl peroxycarbonate, and tert-butyl peroxy-3,3,5-trimethylhexanoate; and / or the first co-crosslinking agent is selected from 1,3,5-triallyl cyanurate. The crosslinking agent comprises at least one of dicumyl peroxide, benzoyl peroxide, amyl acetate peroxide, tert-amyl peroxide 3,5,5-trimethylhexanoate, di-tert-butyl peroxide, tert-butyl peroxyisopropyl carbonate, dicyclohexyl peroxydicarbonate, bis(2-phenylethoxy) peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, and tert-butyl peroxyt-valerate; and / or the first silane coupling agent is selected from γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, At least one of alkyl, γ-(2,3-epoxypropyloxy)propyltrimethoxysilane, vinyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidyloxypropyltrimethylsilane, and 3-aminopropyltrimethylsilane; and / or the first light stabilizer is selected from at least one of 2-(2-hydroxyphenyl)-benzotriazole, a polymer of succinic acid and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol, N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,3-benzenedicarboxamide, 2,2,6,6-tetramethylpiperidinamine, 1,3-diphenylisobenzofuran, and 9,10-anthracenediyl-bis(methylene)dimalonic acid.

[0011] Furthermore, the cut-off film is a single-layer cut-off film, and the single-layer cut-off film includes 0.1 to 0.8 parts by weight of a fourth ultraviolet cut-off agent, and the fourth ultraviolet cut-off agent is selected from any one or more of N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 4-methoxybenzylidene dimethyl malonate and 2-cyano-3,3-diphenyl ethyl acrylate; preferably, the fourth ultraviolet cut-off agent is a combination of N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 4-methoxybenzylidene dimethyl malonate and 2-cyano-3,3-diphenyl ethyl acrylate, and the mass ratio of N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 4-methoxybenzylidene dimethyl malonate and 2-cyano-3,3-diphenyl ethyl acrylate is 1 to 3:1 to 2:1 to 2.

[0012] Furthermore, the light transmittance of the cut-off film in the 250-300nm band is 0.5-30%, the light transmittance in the 280-320nm band is 0-8%, and the light transmittance in the 300-320nm band is 0-5%.

[0013] Furthermore, the single-layer cut-off adhesive film further comprises, in parts by weight: 95 to 99.68 parts of a second polymer resin, 0.1 to 1 parts of a second cross-linking agent, 0.1 to 1 parts of a second auxiliary cross-linking agent, 0.1 to 1 parts of a second silane coupling agent; and 0.1 to 1 parts of a second light stabilizer; wherein the second polymer resin is selected from at least one of ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer and ethylene-methyl methacrylate copolymer; and / or the second cross-linking agent is selected from tert-butyl peroxy isopropyl carbonate, 2,5-dimethyl-2,5-(bis-tert-butylperoxy)hexane, tert-butyl peroxide At least one of 2-ethylhexyl carbonate, 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, tert-amyl peroxy 2-ethylhexyl carbonate, 2,5-dimethyl 2,5-dimethyl 2,5-dimethyl 2,5-bis(benzoylperoxy)-hexane, tert-amyl peroxy carbonate, and tert-butyl peroxy 3,3,5-trimethylhexanoate; and / or the second auxiliary crosslinking agent is selected from 1,3,5-triallyl cyanurate, trimethylolpropane tripropylene glycol, 1,1-bis(tert-amylperoxy)cyclohexane, 1,1-bis(tert-butylperoxy)cyclohexane, 2,2-bis(tert-butylperoxy)butane, tert-amyl peroxy 2-ethylhexyl carbonate, 2,5-dimethyl 2,5-dimethyl 2,5-dimethyl 2,5-bis(benzoylperoxy)-hexane, tert-amyl peroxy carbonate, and tert-butyl peroxy 3,3,5-trimethylhexanoate; The crosslinking agent comprises at least one of dicumyl peroxide, benzoyl peroxide, amyl acetate peroxide, tert-amyl peroxide 3,5,5-trimethylhexanoate, di-tert-butyl peroxide, tert-butyl peroxyisopropyl carbonate, dicyclohexyl peroxydicarbonate, bis(2-phenylethoxy) peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, and tert-butyl peroxyt-valerate; and / or the disilane coupling agent is selected from γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-(2, At least one of 3-glycidoxy)propyltrimethoxysilane, vinyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethylsilane, and 3-aminopropyltrimethylsilane; and / or, the second light stabilizer is selected from at least one of 2-(2-hydroxyphenyl)-benzotriazole, a polymer of succinic acid and (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol), N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,3-benzenedicarboxamide, 2,2,6,6-tetramethylpiperidinamine, 1,3-diphenylisobenzofuran, and 9,10-anthracenediyl-bis(methylene)dimalonic acid.

[0014] According to another aspect of the present invention, a photovoltaic module is provided, comprising an adhesive film, wherein the adhesive film is the above-mentioned cut-off adhesive film.

[0015] By applying the technical solution of the present invention, the full-band UV cutoff film not only blocks harmful UV radiation, but also unnecessarily blocks some beneficial UV light from entering the solar cell panel. In contrast, the cutoff film of the present application can not only precisely control the cutoff of the above three UV bands, so that the transmittance of the above three bands reaches the above range, thereby enabling it to more effectively protect the battery from the influence of specific short-wave UV light, while allowing ultraviolet light of other wavelengths to continue to provide power benefits to the battery. At the same time, the cutoff film of the present application can not only increase the initial power of the photovoltaic module, but also help maintain the power output stability of the photovoltaic module during long-term operation, reduce the performance degradation of the photovoltaic module, and thus extend the service life of the photovoltaic module. DETAILED DESCRIPTION

[0016] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0017] As analyzed in the background technology of this application, there is a problem in the prior art that the initial power attenuation of conventional full-band UV cutoff film component batteries is relatively high. In order to solve the above problem, this application provides a cutoff film and a photovoltaic component.

[0018] In a typical embodiment of the present application, a cut-off film is provided, which has a transmittance of 0.5-35% in the 250-300nm band, a transmittance of 0-10% in the 280-320nm band, and a transmittance of 0-10% in the 300-320nm band.

[0019] While full-band UV cutoff films block harmful UV radiation, they also unnecessarily prevent some beneficial UV light from entering the solar panel. In contrast, the cutoff film of the present application can not only precisely control the cutoff of the above three UV bands, so that the transmittance of the above three bands reaches the above range, thereby enabling it to more effectively protect the battery from the influence of specific short-wave UV light, while allowing ultraviolet light of other wavelengths to continue to provide power benefits to the battery. At the same time, the cutoff film of the present application can not only increase the initial power of the photovoltaic module, but also help maintain the power output stability of the photovoltaic module during long-term operation, reduce the performance degradation of the photovoltaic module, and thus extend the service life of the photovoltaic module.

[0020] In one embodiment of the present application, the cut-off film is a three-layer cut-off film, and the three-layer cut-off film includes a first cut-off film layer, a second cut-off film layer and a third cut-off film layer sequentially stacked in the thickness direction of the cut-off film, the first cut-off film layer includes 0 to 0.9 parts by weight of the first UV cut-off agent, preferably 0.1 to 0.9, more preferably 0.3 to 0.5 parts, the second cut-off film layer includes 0.3 to 3 parts by weight of the second UV cut-off agent, preferably 0.3 to 2.4 parts, more preferably 1.5 to 1.7 parts, the third cut-off film layer includes 0 to 0.9 parts by weight of the third UV cut-off agent, preferably The first UV cut-off agent is selected from 2-cyano-3,3-diphenyl ethyl acrylate, 2,4-dihydroxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, N,N'-bis(4-ethoxyformylphenyl)-N-benzylformamidine, 2,2'-methylenebis(4-tert-octyl-6-benzotriazolephenol), 4-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 3-diphenyl acrylate, tetraethyl 2,2'-(1,4-phenylenedimethylene) dimalonate, isooctyl salicylate. Any one or more of salicylic acid isooctyl salicylate, N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, salicylic acid, methyl salicylate, ethylhexyl-3 (4-methoxyphenyl)-acrylate, salicylic acid-4-tert-butylphenyl ester, trimethylcyclohexyl salicylic acid, and cinnamic acid UV cut-off agents; the second UV cut-off agent is selected from salicylic acid isooctyl ester, N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, salicylic acid, methyl salicylate, ethylhexyl-3 (4-methoxyphenyl)-acrylate, salicylic acid-4-tert-butylphenyl ester, trimethylcyclohexyl salicylic acid, and cinnamic acid UV cut-off agents. Any one or more of the cut-off agents; the third UV cut-off agent is selected from 3,5-di-tert-butyl-4-hydroxybenzoate, titanium dioxide, zinc oxide, 3-diphenylacrylate, 2-phenyl-5-benzimidazole sulfonic acid, p-aminobenzoic acid and 4-methoxybenzylidenemalonic acid dimethyl ester, isooctyl salicylate, N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, salicylic acid, methyl salicylate, ethylhexyl-3 (4-methoxyphenyl)-acrylate, salicylic acid-4-tert-butylphenyl ester, trimethylcyclohexyl salicylic acid, and any one or more of the cinnamic acid UV cut-off agents.

[0021] The cinnamic acid UV cut-off agent is selected from any one or more of octyl cinnamate, butyl cinnamate, 2-ethylhexyl cinnamate, isopropyl cinnamate, and phenylethyl cinnamate.

[0022] The first cutoff film layer has a light transmittance of 0-10% in the 250-300nm band, a light transmittance of 0-10% in the 280-320nm band, and a light transmittance of 0-10% in the 300-320nm band. The second cutoff film layer has a light transmittance of 0.5-35% in the 250-300nm band, a light transmittance of 0-10% in the 280-320nm band, and a light transmittance of 0-10% in the 300-320nm band, preferably 0-5%. The third cutoff film layer has a light transmittance of 0-5% in the 250-300nm band, a light transmittance of 0-7% in the 280-320nm band, and a light transmittance of 0-85% in the 300-320nm band.

[0023] In one embodiment of the present application, the first UV cutoff agent is a combination of 2-cyano-3,3-diphenyl ethyl acrylate and 2,2'-(1,4-phenylenediamine) dimalonic acid tetraethyl ester, and the mass ratio of 2-cyano-3,3-diphenyl ethyl acrylate and 2,2'-(1,4-phenylenediamine) dimalonic acid tetraethyl ester in the first UV cutoff agent is 1 to 2:1 to 2; and / or, the second UV cutoff agent is isooctyl salicylate and N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)- The mass ratio of isooctyl salicylate and N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide in the second UV cutoff agent is 1 to 5:1 to 5; and / or the third UV cutoff agent is a combination of 3,5-di-tert-butyl-4-hydroxybenzoate and dimethyl 4-methoxybenzylidene malonate, and the mass ratio of 3,5-di-tert-butyl-4-hydroxybenzoate and dimethyl 4-methoxybenzylidene malonate in the third UV cutoff agent is 1 to 2:1 to 3.

[0024] In the first UV cutoff agent, 2-cyano-3,3-diphenyl ethyl acrylate is a UV cutoff agent with high absorption capacity. It can effectively absorb ultraviolet rays in the short-wave ultraviolet band (300-330nm). Its molecular structure enables it to form a stable light absorption layer in the film, which can maintain good performance even under long-term light exposure and high temperature environments. 2,2'-(1,4-phenylenedimethylene) dimalonic acid tetraethyl ester performs well in the slightly longer UV band (300-340nm), which helps to broaden the UV cutoff range of the cutoff film, thereby providing comprehensive protection for sensitive bands. The preferred first UV cutoff agent is a combination of 2-cyano-3,3-diphenyl ethyl acrylate and 2,2'-(1,4-phenylenedimethylene) dimalonic acid tetraethyl ester, and controlling the mass ratio of the two within the above range helps to further improve the anti-aging performance, thereby reducing the attenuation rate of the cutoff agent.

[0025] In the second ultraviolet cutoff agent, isooctyl salicylate exhibits good absorption properties in the ultraviolet band (approximately 280 to 320 nm), while N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide has a strong absorption capacity in the ultraviolet band (approximately 320 to 400 nm). Preferably, the second ultraviolet cutoff agent is a combination of isooctyl salicylate and N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, and the mass ratio of the two is controlled within the above range, which helps to form a continuous and extensive ultraviolet absorption band. While maintaining strong absorption of specific short-wave ultraviolet light, it enables efficient transmission of ultraviolet and visible light in other bands, thereby more comprehensively protecting the solar cell from the influence of harmful ultraviolet radiation.

[0026] In the third UV cutoff agent, 3,5-di-tert-butyl-4-hydroxybenzoate exhibits excellent performance in the UV-A and partial UV-B bands (280-320 nm), while 4-methoxybenzylidene dimethyl malonate has excellent absorption capabilities in the UV-B and UV-C bands (particularly short-wave UV <280 nm). Preferably, the third UV cutoff agent is a combination of 3,5-di-tert-butyl-4-hydroxybenzoate and 4-methoxybenzylidene dimethyl malonate, and the mass ratio of the two is controlled within the above range. This helps to create a broader and more efficient UV cutoff spectrum, allowing the cutoff film to more accurately shield the short-wave UV that is harmful to solar cells while allowing the spectrum that is beneficial to energy conversion to pass through.

[0027] The thickness of the first, second and third stop film layers are independently 100-150 mm, and the thickness ratio of the first, second and third stop film layers is 0-1:0-1:0-1, preferably 0.2-1:0.2-1:0.2-1.

[0028] The preferred thickness ratio of the first, second, and third cutoff film layers is controlled within the above range. This not only helps further optimize the absorption of UV light in different wavelength bands, but also helps improve the mechanical properties of the cutoff film, such as strength, flexibility, and durability. The thickness design of the different cutoff film layers takes into account the stress distribution of the cutoff film during packaging and operation, helping to reduce problems such as cracking and delamination caused by excessive stress concentration, thereby improving the reliability and lifespan of the component.

[0029] In one embodiment of the present application, the mass ratio of the first ultraviolet cutoff agent, the second ultraviolet cutoff agent and the third ultraviolet cutoff agent is 0.5-1.5:1-3.5:1-2.

[0030] It is preferred to control the mass ratio of the first ultraviolet cutoff agent, the second ultraviolet cutoff agent and the third ultraviolet cutoff agent within the above range, which helps to further improve the synergistic effect of the first cutoff film layer, the second cutoff film layer and the first cutoff film layer, thereby achieving efficient cutoff of the cutoff film for the above ultraviolet band.

[0031] In order to further improve the ultraviolet blocking performance of the blocking film, in one embodiment of the present application, the transmittance of the blocking film in the 250-300nm band is 0.5-28%, the transmittance in the 280-320nm band is 0-7%, and the transmittance in the 300-320nm band is 0-5%.

[0032] In one embodiment of the present application, the first cut-off film layer, the second cut-off film layer and the third cut-off film layer further independently comprise, by weight, 95 to 99.68 parts of a first polymer resin, 0.1 to 1 parts of a first cross-linking agent, 0.1 to 1 parts of a first auxiliary cross-linking agent, 0.1 to 1 parts of a first silane coupling agent and 0.1 to 1 parts of a first light stabilizer; wherein the first polymer resin is selected from at least one of ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer and ethylene-methyl methacrylate copolymer; and / or the first cross-linking agent is selected from tert-butyl peroxyisopropyl carbonate, 2,5-dimethyl- At least one of 2,5-(bis-tert-butylperoxy)hexane, tert-butylperoxycarbonate-2-ethylhexyl ester, 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, tert-amyl peroxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-dimethyl-2,5-dimethyl-2,5-bis(benzoylperoxy)-hexane, tert-amyl peroxycarbonate, and tert-butyl peroxy-3,3,5-trimethylhexanoate; and / or the first auxiliary cross-linking agent is selected from 1,3,5-cyanuric acid At least one of triallyl ester, trimethylolpropane triacrylate, triallyl isocyanurate, and polytriallyl isocyanurate; and / or, the crosslinking agent includes dicumyl peroxide, benzoyl peroxide, amyl acetate peroxide, tert-amyl peroxide 3,5,5-trimethylhexanoate, di-tert-butyl peroxide, tert-butyl peroxyisopropyl carbonate, dicyclohexyl peroxydicarbonate, bis(2-phenylethoxy) peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, and tert-butyl peroxyt-valerate; and / or, the first silane coupling agent is selected from γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, At least one of silane, γ-(2,3-epoxypropyloxy)propyltrimethoxysilane, vinyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidyloxypropyltrimethylsilane, and 3-aminopropyltrimethylsilane; and / or the first light stabilizer is selected from at least one of 2-(2-hydroxyphenyl)-benzotriazole, a polymer of succinic acid and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol, N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,3-benzenedicarboxamide, 2,2,6,6-tetramethylpiperidinamine, 1,3-diphenylisobenzofuran, and 9,10-anthracenediyl-bis(methylene)dimalonic acid.

[0033] Preferably, the composition and content of the first cut-off film layer, the second cut-off film layer and the third cut-off film layer are within the above ranges, which helps to better cooperate with the UV cut-off agent, thereby promoting the uniformity and stability of the structure of each film layer.

[0034] In one embodiment of the present application, the cut-off film is a single-layer cut-off film, and the single-layer cut-off film includes 0.1 to 0.8 parts by weight of a fourth ultraviolet cut-off agent, preferably 0.3 to 0.5 parts, and the fourth ultraviolet cut-off agent is selected from any one or more of N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 4-methoxybenzylidene dimethyl malonate and 2-cyano-3,3-diphenyl ethyl acrylate; preferably, the fourth ultraviolet cut-off agent is a combination of N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 4-methoxybenzylidene dimethyl malonate and 2-cyano-3,3-diphenyl ethyl acrylate, and the mass ratio of N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 4-methoxybenzylidene dimethyl malonate and 2-cyano-3,3-diphenyl ethyl acrylate is 1 to 3:1 to 2:1 to 2.

[0035] The cut-off film is preferably a single-layer cut-off film, and the content and type of the fourth ultraviolet cut-off agent in the single-layer cut-off film are controlled within the above range, which helps to effectively protect the battery from the influence of specific short-wave ultraviolet light, while allowing ultraviolet light of other wavelengths to continue to provide power benefits to the battery, and also helps to reduce costs. The fourth ultraviolet cut-off agent is preferably a combination of N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 4-methoxybenzylidenemalonic acid dimethyl ester and 2-cyano-3,3-diphenylacrylate, and the mass ratio of the three is controlled within the above range, which helps to improve the synergistic effect of the three, thereby more effectively protecting the battery from the influence of specific short-wave ultraviolet light, while allowing ultraviolet light of other wavelengths to continue to provide power benefits to the battery.

[0036] In order to further improve the ultraviolet blocking performance of the blocking film, in one embodiment of the present application, the transmittance of the blocking film in the 250-300nm band is 0.5-30%, the transmittance in the 280-320nm band is 0-8%, and the transmittance in the 300-320nm band is 0-5%.

[0037] In one embodiment of the present application, the single-layer cut-off adhesive film further comprises, by weight: 95 to 99.68 parts of a second polymer resin, 0.1 to 1 parts of a second cross-linking agent, 0.1 to 1 parts of a second auxiliary cross-linking agent, 0.1 to 1 parts of a second silane coupling agent, and 0.1 to 1 parts of a second light stabilizer; wherein the second polymer resin is selected from at least one of ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer, and ethylene-methyl methacrylate copolymer; and / or the second cross-linking agent is selected from tert-butyl peroxyisopropyl carbonate, 2,5-dimethyl-2,5-(bis-tert-butylperoxy)hexane, tert-butyl At least one of 2-ethylhexyl peroxycarbonate, 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, tert-amyl peroxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-dimethyl-2,5-dimethyl-2,5-bis(benzoylperoxy)-hexane, tert-amyl peroxycarbonate, and tert-butyl peroxy-3,3,5-trimethylhexanoate; and / or the second auxiliary crosslinking agent is selected from 1,3,5-triallylcyanurate, trimethylolpropane At least one of triacrylate, triallyl isocyanurate, and polytriallyl isocyanurate; and / or, the crosslinking agent includes dicumyl peroxide, benzoyl peroxide, amyl acetate peroxide, tert-amyl peroxide 3,5,5-trimethylhexanoate, di-tert-butyl peroxide, tert-butyl peroxyisopropyl carbonate, dicyclohexyl peroxydicarbonate, bis(2-phenylethoxy) peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, and tert-butyl peroxyt-valerate; and / or, the disilane coupling agent is selected from γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-(2 ,3-glycidoxy)propyltrimethoxysilane, vinyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidyloxypropyltrimethylsilane, 3-aminopropyltrimethylsilane; and / or, the second light stabilizer is selected from at least one of 2-(2-hydroxyphenyl)-benzotriazole, a polymer of succinic acid and (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol), N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,3-benzenedicarboxamide, 2,2,6,6-tetramethylpiperidinamine, 1,3-diphenylisobenzofuran, and 9,10-anthracenediyl-bis(methylene)dimalonic acid.

[0038] It is preferred that the composition and content of the single-layer cut-off film be within the above ranges, which helps to better cooperate with the fourth ultraviolet cut-off agent, thereby promoting the uniformity of the composition of the single-layer cut-off film.

[0039] In another typical embodiment of the present application, a photovoltaic module is provided, comprising an adhesive film, which is the above-mentioned cut-off adhesive film.

[0040] Compared with photovoltaic modules using full-band UV cutoff films, the photovoltaic modules of the present application including the above-mentioned cutoff films have higher initial power and can maintain power output stability during long-term operation, thereby extending the service life of the photovoltaic modules.

[0041] The beneficial effects of the present application will be further illustrated below with reference to examples.

[0042] Example 1

[0043] The three-layer cut-off film consists of a first cut-off film layer, a second cut-off film layer and a third cut-off film layer which are sequentially stacked along the thickness direction of the cut-off film.

[0044] In parts by weight, the raw materials of the first cut-off film layer are 0.45 parts of the first UV cut-off agent 2-cyano-3,3-diphenyl ethyl acrylate, 98 parts of the polymer resin ethylene-vinyl acetate copolymer (DuPont, USA), 0.5 parts of the cross-linking agent tert-butyl peroxyisopropyl carbonate, 0.3 parts of the auxiliary cross-linking agent 1,3,5-triallyl cyanurate, 0.5 parts of the silane coupling agent γ-aminopropyltriethoxysilane and 0.4 parts of the light stabilizer 2-(2-hydroxyphenyl)-benzotriazole.

[0045] In parts by weight, the raw materials of the second cut-off film layer are 1.2 parts of the second UV cut-off agent isooctyl salicylate, 97 parts of the polymer resin ethylene-vinyl acetate copolymer (DuPont, USA), 0.5 parts of the cross-linking agent tert-butyl peroxyisopropyl carbonate, 0.3 parts of the auxiliary cross-linking agent 1,3,5-triallyl cyanurate, 0.5 parts of the silane coupling agent γ-aminopropyltriethoxysilane and 0.5 parts of the light stabilizer 2-(2-hydroxyphenyl)-benzotriazole.

[0046] In parts by weight, the raw materials of the third cut-off film layer are 0.45 parts of the third UV cut-off agent 4-methoxybenzylidene dimethyl malonate, 98 parts of the polymer resin ethylene-vinyl acetate copolymer (DuPont, USA), 0.5 parts of the cross-linking agent tert-butyl peroxyisopropyl carbonate, 0.4 parts of the auxiliary cross-linking agent 1,3,5-triacyl cyanurate, 0.5 parts of the silane coupling agent γ-aminopropyltriethoxysilane and 0.3 parts of the light stabilizer 2-(2-hydroxyphenyl)-benzotriazole.

[0047] The raw materials of the above film layers are mixed and dried respectively, and co-extruded through a T-die using a twin-screw extruder to obtain a cut-off film containing a first cut-off film layer, a second cut-off film layer and a third cut-off film layer.

[0048] Example 2

[0049] The difference from Example 1 is that, in parts by weight, the raw materials of the first cut-off film layer are 0.1 parts of the first UV cut-off agent 2-cyano-3,3-diphenyl ethyl acrylate, 97.8 parts of the polymer resin ethylene-vinyl acetate copolymer, 1 part of the cross-linking agent tert-butyl peroxyisopropyl carbonate, 0.1 parts of the auxiliary cross-linking agent 1,3,5-triallyl cyanurate, 1 part of the silane coupling agent γ-aminopropyltriethoxysilane and 0.1 parts of the light stabilizer 2-(2-hydroxyphenyl)-benzotriazole.

[0050] In parts by weight, the raw materials of the second cut-off film layer are 0.3 parts of the second UV cut-off agent isooctyl salicylate, 97.5 parts of the polymer resin ethylene-vinyl acetate copolymer, 0.1 parts of the cross-linking agent tert-butyl peroxyisopropyl carbonate, 1 part of the auxiliary cross-linking agent 1,3,5-triacyl cyanurate, 0.1 parts of the silane coupling agent γ-aminopropyltriethoxysilane and 1 part of the light stabilizer 2-(2-hydroxyphenyl)-benzotriazole.

[0051] In parts by weight, the raw materials of the third cut-off film layer are 0.1 parts of the third UV cut-off agent 4-methoxybenzylidene dimethyl malonate, 97.8 parts of the polymer resin ethylene-vinyl acetate copolymer, 1 part of the cross-linking agent tert-butyl peroxyisopropyl carbonate, 0.1 parts of the auxiliary cross-linking agent 1,3,5-triacyl cyanurate, 1 part of the silane coupling agent γ-aminopropyltriethoxysilane and 0.1 parts of the light stabilizer 2-(2-hydroxyphenyl)-benzotriazole, and finally a cut-off film is obtained.

[0052] Example 3

[0053] The difference from Example 1 is that, in parts by weight, the raw materials of the first cut-off film layer are 0.9 parts of the first UV cut-off agent 2,4-dihydroxybenzophenone, 96.9 parts of the polymer resin ethylene-propylene copolymer, 0.1 parts of the cross-linking agent tert-butyl peroxyisopropyl carbonate, 1 part of the auxiliary cross-linking agent 1,3,5-triacyl cyanurate, 0.1 parts of the silane coupling agent γ-aminopropyltriethoxysilane and 1 part of the light stabilizer 2-(2-hydroxyphenyl)-benzotriazole.

[0054] In parts by weight, the raw materials of the second cut-off film layer are 2.4 parts of the second UV cut-off agent N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 95.4 parts of the polymer resin ethylene-propylene copolymer, 1 part of the cross-linking agent tert-butyl peroxyisopropyl carbonate, 0.1 part of the auxiliary cross-linking agent 1,3,5-triacyl cyanurate, 1 part of the silane coupling agent γ-aminopropyltriethoxysilane and 0.1 part of the light stabilizer 2-(2-hydroxyphenyl)-benzotriazole.

[0055] In parts by weight, the raw materials of the third cutoff film layer are 0.9 parts of the third UV cutoff agent 3,5-di-tert-butyl-4-hydroxybenzoate, 96.9 parts of the polymer resin ethylene-propylene copolymer, 0.1 parts of the crosslinking agent tert-butyl peroxyisopropyl carbonate, 1 part of the auxiliary crosslinking agent 1,3,5-triacyl cyanurate, 0.1 parts of the silane coupling agent γ-aminopropyltriethoxysilane and 1 part of the light stabilizer 2-(2-hydroxyphenyl)-benzotriazole, and finally a cutoff film is obtained.

[0056] Example 4

[0057] The difference from Example 1 is that the first UV cutoff agent is a combination of 2-cyano-3,3-diphenyl ethyl acrylate and 2,2'-(1,4-phenylenediamine)dimalonic acid tetraethyl ester, and the mass ratio of 2-cyano-3,3-diphenyl ethyl acrylate and 2,2'-(1,4-phenylenediamine)dimalonic acid tetraethyl ester is 1:1, and a cutoff film is finally obtained.

[0058] Example 5

[0059] The difference from Example 1 is that the first UV cutoff agent is a combination of 2-cyano-3,3-diphenyl ethyl acrylate and 2,2'-(1,4-phenylenediamine)dimalonic acid tetraethyl ester, and the mass ratio of 2-cyano-3,3-diphenyl ethyl acrylate and 2,2'-(1,4-phenylenediamine)dimalonic acid tetraethyl ester is 1:3, and a cutoff film is finally obtained.

[0060] Example 6

[0061] The difference from Example 1 is that the second UV cutoff agent is a combination of isooctyl salicylate and N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, the mass ratio of isooctyl salicylate and N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide is 1:2, and a cutoff film is finally obtained.

[0062] Example 7

[0063] The difference from Example 1 is that the second UV cutoff agent is a combination of isooctyl salicylate and N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, the mass ratio of isooctyl salicylate and N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide is 1:6, and a cutoff film is finally obtained.

[0064] Example 8

[0065] The difference from Example 1 is that the third UV cutoff agent is a combination of 3,5-di-tert-butyl-4-hydroxybenzoate and 4-methoxybenzylidene dimethyl malonate, and the mass ratio of 3,5-di-tert-butyl-4-hydroxybenzoate and 4-methoxybenzylidene dimethyl malonate is 2:1, and a cutoff film is finally obtained.

[0066] Example 9

[0067] The difference from Example 1 is that the third UV cutoff agent is a combination of 3,5-di-tert-butyl-4-hydroxybenzoate and 4-methoxybenzylidene dimethyl malonate, and the mass ratio of 3,5-di-tert-butyl-4-hydroxybenzoate and 4-methoxybenzylidene dimethyl malonate is 3:1, and a cutoff film is finally obtained.

[0068] Example 10

[0069] The difference from Example 1 is that the weight portions of the first UV cutoff agent, the second UV cutoff agent and the third UV cutoff agent are 0.17 parts, 1.2 parts, and 0.34 parts, respectively, and the mass ratio of the first UV cutoff agent, the second UV cutoff agent and the third UV cutoff agent is 0.5:3.5:1, and a cutoff film is finally obtained.

[0070] Example 11

[0071] The difference from Example 1 is that the weight portions of the first UV cutoff agent, the second UV cutoff agent and the third UV cutoff agent are 0.6 parts, 0.6 parts, and 0.9 parts, respectively, and the mass ratio of the first UV cutoff agent, the second UV cutoff agent and the third UV cutoff agent is 1:1:1.5, and a cutoff film is finally obtained.

[0072] Example 12

[0073] The difference from Example 1 is that the weight portions of the first UV cutoff agent, the second UV cutoff agent and the third UV cutoff agent are 1.2 parts, 0.6 parts, and 0.6 parts, respectively, and the mass ratio of the first UV cutoff agent, the second UV cutoff agent and the third UV cutoff agent is 2:1:1, and a cutoff film is finally obtained.

[0074] Example 13

[0075] In parts by weight, the raw materials of the single-layer cut-off film layer are 0.4 parts of the fourth ultraviolet cut-off agent N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 97.4 parts of the polymer resin ethylene-vinyl acetate copolymer, 1 part of the cross-linking agent tert-butyl peroxyisopropyl carbonate, 0.1 parts of the auxiliary cross-linking agent 1,3,5-triacyl cyanurate, 1 part of the silane coupling agent γ-aminopropyltriethoxysilane and 0.1 parts of the light stabilizer 2-(2-hydroxyphenyl)-benzotriazole.

[0076] The above raw materials are mixed, dried and then melt-extruded to obtain a cut-off film.

[0077] Example 14

[0078] The difference from Example 13 is that, in parts by weight, the raw materials of the single-layer cut-off film layer are 0.1 parts of the fourth ultraviolet cut-off agent N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 95 parts of the polymer resin ethylene-vinyl acetate copolymer, 1 part of the cross-linking agent tert-butyl peroxyisopropyl carbonate, 0.1 parts of the auxiliary cross-linking agent 1,3,5-triacyl cyanurate, 1 part of the silane coupling agent γ-aminopropyltriethoxysilane and 0.1 parts of the light stabilizer 2-(2-hydroxyphenyl)-benzotriazole, and finally a cut-off film is obtained.

[0079] Example 15

[0080] The difference from Example 13 is that, in parts by weight, the raw materials of the single-layer cut-off film layer are 0.8 parts of the fourth UV cut-off agent 4-methoxybenzylidene dimethyl malonate, 99.68 parts of the polymer resin ethylene-propylene copolymer, 0.1 parts of the cross-linking agent tert-butyl peroxyisopropyl carbonate, 1 part of the auxiliary cross-linking agent 1,3,5-triacyl cyanurate, 0.1 parts of the silane coupling agent γ-aminopropyltriethoxysilane and 1 part of the light stabilizer 2-(2-hydroxyphenyl)-benzotriazole, and finally a cut-off film is obtained.

[0081] Example 16

[0082] The difference from Example 13 is that the fourth UV cutoff agent is a combination of N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 4-methoxybenzylidene dimethyl malonate and 2-cyano-3,3-diphenyl ethyl acrylate, and the mass ratio of N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 4-methoxybenzylidene dimethyl malonate and 2-cyano-3,3-diphenyl ethyl acrylate is 1:2:2, and a cutoff film is finally obtained.

[0083] Example 17

[0084] The difference from Example 13 is that the fourth UV cutoff agent is a combination of N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 4-methoxybenzylidene dimethyl malonate and 2-cyano-3,3-diphenyl ethyl acrylate, and the mass ratio of N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 4-methoxybenzylidene dimethyl malonate and 2-cyano-3,3-diphenyl ethyl acrylate is 1:3:3, and a cutoff film is finally obtained.

[0085] Comparative Example 1

[0086] In parts by weight, the raw materials of the first cut-off film layer are 97.6 parts of polymer resin ethylene-vinyl acetate copolymer, 1 part of cross-linking agent tert-butyl peroxyisopropyl carbonate, 0.1 part of auxiliary cross-linking agent 1,3,5-triacyl cyanurate, 1 part of silane coupling agent γ-aminopropyltriethoxysilane and 0.2 part of light stabilizer 2-(2-hydroxyphenyl)-benzotriazole.

[0087] In parts by weight, the raw materials of the second cut-off film layer are 96.1 parts of the polymer resin ethylene-vinyl acetate copolymer, 1 part of the cross-linking agent tert-butyl peroxyisopropyl carbonate, 0.1 part of the auxiliary cross-linking agent 1,3,5-triacyanuric acid triallyl ester, 1 part of the silane coupling agent γ-aminopropyltriethoxysilane and 0.2 part of the light stabilizer 2-(2-hydroxyphenyl)-benzotriazole.

[0088] In parts by weight, the raw materials of the third cut-off film layer are 97.6 parts of the polymer resin ethylene-vinyl acetate copolymer, 1 part of the cross-linking agent tert-butyl peroxyisopropyl carbonate, 0.1 part of the auxiliary cross-linking agent 1,3,5-triallyl cyanurate, 1 part of the silane coupling agent γ-aminopropyltriethoxysilane and 0.2 part of the light stabilizer 2-(2-hydroxyphenyl)-benzotriazole.

[0089] The raw materials of the above film layers are mixed and dried respectively, and a twin-screw extruder is used to obtain a first cut-off film layer, a second cut-off film layer and a third cut-off film layer respectively, and a multi-layer co-extrusion is performed to obtain a cut-off film.

[0090] Test method:

[0091] Transmittance test: The film was pressed into sheets of equal thickness (0.45 mm) using a laminator. The transmittance data in the range of 200 to 1200 nm was tested using an ultraviolet spectrophotometer, and the average transmittance in the specific range was calculated.

[0092] Yellowing value testing after UV30 aging: Cut the film sample into 8×8 cm square sheets and laminate them to ensure uniform film thickness. After lamination, place the sample in a UV aging chamber for irradiation. After irradiation dose of UV30, remove the sample and test it using a spectrophotometer.

[0093] The above tests are shown in Table 1.

[0094] Table 1

[0095]

[0096]

[0097] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0098] While full-band UV cutoff films block harmful UV radiation, they also unnecessarily prevent some beneficial UV light from entering the solar panel. In contrast, the cutoff film of the present application can not only precisely control the cutoff of the above three UV bands, so that the transmittance of the above three bands reaches the above range, thereby enabling it to more effectively protect the battery from the influence of specific short-wave UV light, while allowing ultraviolet light of other wavelengths to continue to provide power benefits to the battery. At the same time, the cutoff film of the present application can not only increase the initial power of the photovoltaic module, but also help maintain the power output stability of the photovoltaic module during long-term operation, reduce the performance degradation of the photovoltaic module, and thus extend the service life of the photovoltaic module.

[0099] The above are merely embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A cut-off film, characterized in that: The light transmittance of the cut-off film in the 250-300nm band is 0.5-35%, the light transmittance in the 280-320nm band is 0-10%, and the light transmittance in the 300-320nm band is 0-10%.

2. The cut-off film according to claim 1, characterized in that The cut-off film is a three-layer cut-off film, comprising a first cut-off film layer, a second cut-off film layer, and a third cut-off film layer sequentially stacked along the thickness direction of the cut-off film, the first cut-off film layer comprising 0 to 0.9 parts by weight of a first ultraviolet cut-off agent, preferably 0.1 to 0.9 parts, the second cut-off film layer comprising 0.3 to 3 parts by weight of a second ultraviolet cut-off agent, preferably 0.3 to 2.4 parts, the third cut-off film layer comprising 0 to 0.9 parts by weight of a third ultraviolet cut-off agent, preferably 0.1 to 0.9 parts; Wherein, the first UV cut-off agent is selected from 2-cyano-3,3-diphenyl ethyl acrylate, 2,4-dihydroxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, N,N'-bis(4-ethoxyformylphenyl)-N-benzylformamidine, 2,2'-methylenebis(4-tert-octyl-6-benzotriazolephenol), 4-dodecyloxy-2-hydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 3-diphenylacrylate Any one or more of isooctyl acrylate, 2,2'-(1,4-phenylenediamine) dimalonic acid tetraethyl ester, isooctyl salicylate, N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, salicylic acid, methyl salicylate, ethylhexyl-3(4-methoxyphenyl)-acrylate, 4-tert-butylphenyl salicylate, trimethylcyclohexyl salicylic acid, and cinnamic acid UV cut-off agents; the second UV cut-off agent is selected from salicylic acid Any one or more of isooctyl ester, N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, salicylic acid, methyl salicylate, ethylhexyl-3 (4-methoxyphenyl)-acrylate, salicylic acid-4-tert-butylphenyl ester, trimethylcyclohexyl salicylic acid, and cinnamic acid UV cut-off agents; the third UV cut-off agent is selected from 3,5-di-tert-butyl-4-hydroxybenzoate, titanium dioxide, zinc oxide, 3-diphenylpropane Any one or more of isooctyl olefinate, 2-phenyl-5-benzimidazole sulfonic acid, p-aminobenzoic acid and dimethyl 4-methoxybenzylidenemalonate, isooctyl salicylate, N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, salicylic acid, methyl salicylate, ethylhexyl-3(4-methoxyphenyl)-acrylate, 4-tert-butylphenyl salicylate, trimethylcyclohexyl salicylic acid, and cinnamic acid UV cut-off agents.

3. The cut-off film according to claim 2, characterized in that: The first ultraviolet cutoff agent is a combination of 2-cyano-3,3-diphenyl ethyl acrylate and 2,2'-(1,4-phenylenediamine) dimalonic acid tetraethyl ester, and the mass ratio of the 2-cyano-3,3-diphenyl ethyl acrylate and the 2,2'-(1,4-phenylenediamine) dimalonic acid tetraethyl ester in the first ultraviolet cutoff agent is 1-2:1-2; And / or, the second UV cutoff agent is a combination of the isooctyl salicylate and the N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, and the mass ratio of the isooctyl salicylate and the N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide in the second UV cutoff agent is 1 to 5:1 to 5; And / or, the third UV cutoff agent is a combination of 3,5-di-tert-butyl-4-hydroxybenzoate and dimethyl 4-methoxybenzylidene malonate, and the mass ratio of 3,5-di-tert-butyl-4-hydroxybenzoate to dimethyl 4-methoxybenzylidene malonate in the third UV cutoff agent is 1-2:1-3.

4. The cut-off film according to claim 2 or 3, characterized in that: The mass ratio of the first ultraviolet cutoff agent, the second ultraviolet cutoff agent and the third ultraviolet cutoff agent is 0.5-1.5:1-3.5:1-2.

5. The cut-off film according to any one of claims 2 to 4, characterized in that: The light transmittance of the cut-off film in the 250-300nm band is 0.5-28%, the light transmittance in the 280-320nm band is 0-7%, and the light transmittance in the 300-320nm band is 0-5%.

6. The cut-off film according to any one of claims 2 to 5, characterized in that: In parts by weight, the first cut-off film layer, the second cut-off film layer and the third cut-off film layer further independently comprise: 95 to 99.68 parts of a first polymer resin; 0.1 to 1 part of a first cross-linking agent; 0.1 to 1 part of a first co-crosslinking agent; 0.1 to 1 part of a first silane coupling agent; and 0.1 to 1 part of a first light stabilizer; Wherein, the first polymer resin is at least one selected from ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer and ethylene-methyl methacrylate copolymer; and / or the first cross-linking agent is selected from at least one of tert-butyl peroxy isopropyl carbonate, 2,5-dimethyl-2,5-(bis-tert-butylperoxy)hexane, tert-butyl peroxy-2-ethylhexyl carbonate, 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, tert-amyl peroxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-dimethyl-2,5-bis(benzoylperoxy)-hexane, tert-amyl peroxy carbonate, and tert-butyl peroxy-3,3,5-trimethylhexanoate; And / or, the first auxiliary cross-linking agent is selected from at least one of 1,3,5-triallyl cyanurate, trimethylolpropane triacrylate, triallyl isocyanurate, and polytriallyl isocyanurate; and / or, the cross-linking agent includes at least one of dicumyl peroxide, benzoyl peroxide, amyl acetate peroxide, tert-amyl peroxide 3,5,5-trimethylhexanoate, di-tert-butyl peroxide, tert-butyl peroxyisopropyl carbonate, dicyclohexyl peroxydicarbonate, bis(2-phenylethoxy) peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, and tert-butyl peroxytivalate; And / or, the first silane coupling agent is at least one selected from γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, vinyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethylsilane, and 3-aminopropyltrimethylsilane; And / or, the first light stabilizer is selected from at least one of 2-(2-hydroxyphenyl)-benzotriazole, a polymer of succinic acid and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol, N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,3-benzenedicarboxamide, 2,2,6,6-tetramethylpiperidinamine, 1,3-diphenylisobenzofuran, and 9,10-anthracenediyl-bis(methylene)dimalonic acid.

7. The cut-off film according to claim 1, characterized in that: The cut-off film is a single-layer cut-off film, and the single-layer cut-off film includes 0.1 to 0.8 parts by weight of a fourth ultraviolet cut-off agent, and the fourth ultraviolet cut-off agent is selected from any one or more of N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 4-methoxybenzylidene dimethyl malonate and 2-cyano-3,3-diphenyl ethyl acrylate; preferably, the fourth ultraviolet cut-off agent is a combination of N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, 4-methoxybenzylidene dimethyl malonate and 2-cyano-3,3-diphenyl ethyl acrylate, and the mass ratio of N-(2-ethoxyphenyl)-N'-(2-ethylphenyl)-oxamide, the 4-methoxybenzylidene dimethyl malonate and the 2-cyano-3,3-diphenyl ethyl acrylate is 1 to 3:1 to 2:1 to 2.

8. The cut-off film according to claim 7, characterized in that: The light transmittance of the cut-off film in the 250-300nm band is 0.5-30%, the light transmittance in the 280-320nm band is 0-8%, and the light transmittance in the 300-320nm band is 0-5%.

9. The cut-off film according to claim 7 or 8, characterized in that: In parts by weight, the single-layer cut-off film further comprises: 95-99.68 parts of a second polymer resin; 0.1 to 1 part of a second cross-linking agent; 0.1 to 1 part of a second co-crosslinking agent; 0.1 to 1 part of a second silane coupling agent; and 0.1 to 1 part of a second light stabilizer; Wherein, the second polymer resin is at least one selected from ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, ethylene-octene copolymer and ethylene-methyl methacrylate copolymer; and / or the second cross-linking agent is selected from at least one of tert-butyl peroxy isopropyl carbonate, 2,5-dimethyl-2,5-(bis-tert-butylperoxy)hexane, tert-butyl peroxy-2-ethylhexyl carbonate, 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, tert-amyl peroxy-2-ethylhexyl carbonate, 2,5-dimethyl-2,5-dimethyl-2,5-bis(benzoylperoxy)-hexane, tert-amyl peroxy carbonate, and tert-butyl peroxy-3,3,5-trimethylhexanoate; and / or the second auxiliary cross-linking agent is selected from at least one of 1,3,5-trimethylolpropane triacrylate, triallyl isocyanurate, and polytriallyl isocyanurate; and / or the cross-linking agent includes at least one of dicumyl peroxide, benzoyl peroxide, amyl acetate peroxide, tert-amyl peroxide 3,5,5-trimethylhexanoate, di-tert-butyl peroxide, tert-butyl peroxyisopropyl carbonate, dicyclohexyl peroxydicarbonate, bis(2-phenylethoxy) peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, bis(4-tert-butylcyclohexyl) peroxydicarbonate, and tert-butyl peroxytivalate; And / or, the disilane coupling agent is selected from γ-aminopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-(2,3-epoxypropoxy)propyltrimethoxysilane, vinyltrimethoxysilane, N-(β-aminoethyl)-γ- At least one of aminopropyltrimethoxysilane, γ-glycidyloxypropyltrimethylsilane, and 3-aminopropyltrimethylsilane; And / or, the second light stabilizer is selected from at least one of 2-(2-hydroxyphenyl)-benzotriazole, a polymer of succinic acid and (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinol), N,N-bis(2,2,6,6-tetramethyl-4-piperidinyl)-1,3-benzenedicarboxamide, 2,2,6,6-tetramethylpiperidinamine, 1,3-diphenylisobenzofuran, and 9,10-anthracenediyl-bis(methylene)dimalonic acid.

10. A photovoltaic module comprising an adhesive film, characterized in that: The adhesive film is the cut-off adhesive film according to any one of claims 1 to 9.

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