Organic-inorganic composite polymer ultraviolet cut-off agent, preparation method and packaging adhesive film

Abstract

The invention belongs to the technical field of photovoltaic materials, and particularly relates to an organic-inorganic composite polymer ultraviolet cut-off agent, a preparation method and a packaging adhesive film, and the preparation method comprises the following steps: heating cyanuric chloride, resorcinol, a Lewis acid catalyst and a solvent 1, 2-dichloroethane for reaction to obtain a solid compound I; dropwise adding acryloyl chloride into the compound I, triethylamine and tetrahydrofuran at low temperature, and precipitating to obtain a solid compound II; the compound II, methyl chloroformate, sodium bicarbonate and methylbenzene are subjected to a heating reflux reaction, and a compound III is obtained; heating the compound III, N, N-dimethylformamide and potassium carbonate, and dropwise adding bromo-isooctane to obtain a compound IV; the compound IV, polyethylene glycol 400, methanesulfonic acid and a toluene solution are subjected to a heating reflux reaction, and a compound V is obtained; the compound V, MTMP, KH-571, a toluene solution and an initiator are subjected to a heating reaction, and a compound VI is obtained; dissolving the compound VI and titanic acid in dichloromethane, adding HCl, dopamine hydrochloride and H2O2, and mixing to obtain a compound VII;

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic materials, and in particular relates to an organic-inorganic composite polymer ultraviolet cut-off agent, a preparation method thereof, and an encapsulating adhesive film. Background Art

[0002] Ultraviolet (UV) rays contained in sunlight can cause harm to human health, the ecological environment, and material structures. Ultraviolet (UV) rays have a short wavelength, high energy, and strong penetrating power, and they have a significant destructive effect on battery and module packaging materials. The impact of UV radiation is particularly prominent for TOPCon cells. Under the irradiation of high-energy UV rays, a large number of Si-H bonds in the passivation layer of TOPCon cells are easily broken, resulting in a decrease in the passivation effect, seriously affecting the service life and reliability of the cells. In addition, UV rays can also damage the passivation layer of the cell, causing aging of the packaging material. Therefore, it is necessary to protect the cell by absorbing or blocking UV rays to prevent UV rays from damaging the cell passivation layer, thereby indirectly maintaining the performance and life of the cell and extending the service life of the photovoltaic module.

[0003] Organic UV blockers convert UV energy into harmless heat and longer-wavelength light, quenching UV-excited molecules or excited states, returning them to their ground state. However, their UV-shielding performance gradually decreases with prolonged exposure to sunlight. While inorganic oxides can effectively block UV rays, they suffer from poor dispersion, leading to the widespread use of organic UV blockers in current adhesive films.

[0004] Therefore, how to overcome the defect of organic UV cutoff agents that cannot maintain long-term light conversion is a technical problem that urgently needs to be solved in this field.

[0005] It should be noted that the above information disclosed in this background technology section is only used to understand the background technology of the present application concept, and therefore, the above description is not considered to constitute information of the prior art. Summary of the Invention

[0006] The embodiments of the present disclosure at least provide an organic-inorganic composite polymer UV cutoff agent, a preparation method thereof, and an encapsulating film.

[0007] In the first aspect, the present disclosure provides an ultraviolet cutoff agent, wherein the ultraviolet cutoff agent is compound VI, specifically three copolymerized polymer ultraviolet cutoff agents, whose chemical structure is

[0008]

[0009] In the second aspect, the embodiment of the present disclosure provides a UV cutoff agent, which is compound VII, specifically an organic-inorganic composite polymer UV cutoff agent with dopamine as a shell and TiO2 / copolymer as a core, and its chemical structure is

[0010]

[0011] In a third aspect, the present disclosure provides a method for preparing a UV cutoff agent, comprising the following steps: S1, stirring cyanuric chloride, resorcinol, a Lewis acid catalyst, and a solvent, 1,2-dichloroethane, and then heating the mixture for reaction. After the reaction is completed, the mixture is filtered to obtain a solid, which is then washed with hydrochloric acid and dried to obtain a solid compound I; S2, stirring compound I, triethylamine, and tetrahydrofuran at low temperature, and adding acryloyl chloride dropwise thereto. After the reaction is completed, the mixture is precipitated in ice water, and the precipitate is recrystallized with ethanol to obtain a solid compound II; S3, mixing compound II, methyl chloroformate, sodium bicarbonate, and toluene, and then heating and refluxing the mixture. After the reaction is completed, the mixture is pressure-distilled and filtered, the solid is collected, and then slurried with n-heptane. Dry to obtain compound III; S4, stir compound III, N,N-dimethylformamide and potassium carbonate evenly, then place in an oil bath and heat, then add isooctane bromide dropwise, reflux reaction after the addition is complete, and after the reaction is completed, extract, distill under reduced pressure and recrystallize, and dry to obtain compound IV; S5, stir compound IV, polyethylene glycol 400, methanesulfonic acid and toluene solution, heat and reflux reaction, after the reaction is completed, distill under reduced pressure, collect the solid, and dry to obtain compound V; S6, stir compound V, MTMP, KH-571 and toluene solution and initiator azobisisobutyronitrile, heat reaction under nitrogen atmosphere, precipitate with petroleum ether after the reaction is completed, collect the solid, and dry to obtain compound VI.

[0012] In an optional embodiment, the following step is further included: S7, dissolving compound VI and titanic acid in dichloromethane, and adding HCl dropwise, then adding dopamine hydrochloride and stirring, adding H2O2 and mixing, transferring the mixed reactants to a hydrothermal reactor, heating for reaction, filtering after the reaction is completed, washing with ethanol, collecting the solid, and finally drying to obtain compound VII, i.e., an organic-inorganic composite polymer UV cutoff agent.

[0013] In an optional embodiment, the Lewis acid catalyst is one of aluminum trichloride, ferric trichloride, zinc chloride, boron trifluoride, and ferric tribromide, and the molar ratio of cyanuric chloride, resorcinol, and Lewis acid catalyst in step S1 is 1:3:3, the heating temperature is 80-100°C, and the reaction time is 6-8h.

[0014] In an optional embodiment, in step S2, the molar ratio of compound I, acryloyl chloride and triethylamine is 1:1:1, the heating temperature is 0-5°C, and the reaction time is 6-8h.

[0015] In an optional embodiment, in step S3, the molar ratio of compound II, methyl chloroformate and sodium bicarbonate is 1:1:1, the heating temperature is 60-100° C., and the reaction time is 4-8 h.

[0016] In an optional embodiment, in step S4, the molar ratio of compound III, isooctane bromide, and potassium carbonate is 1:1.2:1.5, the heating temperature is 70-120° C., and the reaction time is 2-6 h.

[0017] In an optional embodiment, in step S5, the molar ratio of compound IV, polyethylene glycol 400, and methanesulfonic acid is 1:2:0.1, the heating temperature is 80-100° C., and the reaction time is 12-24 h.

[0018] In an optional embodiment, in step S6, the molar ratio of compound V, MTMP, KH-571, and initiator azobisisobutyronitrile is 1:1:1:0.1, the heating temperature is 60-100° C., and the reaction time is 12-24 h.

[0019] In a fourth aspect, the embodiments of the present disclosure also provide a method for preparing an EVA encapsulating film, comprising the following steps: S11, mixing, putting the UV cutoff agent as described above into a mixer with EVA resin and other additives for mixing and stirring to obtain a mixed raw material; S12, extrusion, pouring the mixed raw material into a single-screw extruder, and obtaining an extrudate through melt blending, discharge casting, and roller cooling; S13, film forming, measuring the thickness of the extrudate, pressing the edge, shaping, and then trimming and winding to obtain an EVA encapsulating film.

[0020] In an optional embodiment, the mixed raw materials include the following raw materials in parts by mass: 100 parts of EVA resin, 0.8-2 parts of cross-linking agent, 0.3-2 parts of auxiliary cross-linking agent, 0.3-1 part of coupling agent, 0.1-0.5 parts of antioxidant, 0.1-0.5 parts of light stabilizer, and 0.1-5 parts of UV cut-off agent.

[0021] In an optional embodiment, the cross-linking agent includes any one or more combinations of tert-amyl peroxy (2-ethylhexyl) carbonate, tert-butyl peroxy carbonate-2-ethylhexyl, diisopropyl peroxide, lauroyl peroxide, tert-butyl peroxyisopropyl carbonate, 2,5-dimethyl-2,5-bis (tert-butylperoxy) hexane, diisopropyl ditert-butyl peroxide, and 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane.

[0022] In an optional embodiment, the auxiliary cross-linking agent includes any one or more combinations of triallyl isocyanurate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, trimethylolpropane triacrylate, polyethylene glycol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, and propoxylated pentaerythritol tetraacrylate.

[0023] In an optional embodiment, the coupling agent includes any one or more combinations of vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltri(β-methoxyethoxy)silane, vinyltriisopropylsilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane.

[0024] In an optional embodiment, the antioxidant includes any one or more combinations of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris(2,4-di-tert-butylphenyl) phosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and N,N-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine.

[0025] In an optional embodiment, the light stabilizer includes any one or more combinations of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, mono(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinethanol) succinate, and 3,5-di-tert-butyl-4-hydroxy-benzoic acid hexadecyl ester.

[0026] In a fifth aspect, the embodiments of the present disclosure also provide an EVA encapsulation film, which meets the following conditions: the transmittance of the EVA encapsulation film in the 290-320nm band is less than 10% and the transmittance in the 340-380nm band is greater than 80%; the transmittance of the EVA encapsulation film in the 380-1100nm band is greater than 92%.

[0027] In a sixth aspect, an embodiment of the present disclosure further provides a photovoltaic module, comprising a glass layer, an EVA encapsulation film layer, a solar TOPCon cell sheet, and an EVA encapsulation film layer arranged in sequence; wherein the EVA encapsulation film layer adopts the EVA encapsulation film as described above.

[0028] The beneficial effects of the present invention are as follows: the organic-inorganic composite polymer UV cutoff agent and preparation method, and the encapsulating film first design a new type of triazine UV cutoff agent, using a triazine compound as a skeleton, performing structural modification at different sites, introducing a PEG macromolecular hydrophilic chain and an alkoxy molecular chain, and then copolymerizing with a hindered amine structural unit 2,2,6,6-tetramethylpiperidinol monomer and a methacryloxypropyltriethoxysilane monomer to form a polymer composite cutoff agent with multiple functions and excellent performance through solution copolymerization, and finally using titanic acid and dopamine hydrochloride as raw materials to prepare an organic-inorganic polymer composite cutoff agent of polydopamine-coated TiO2 and a triazine UV cutoff agent; through the above-mentioned design and synthesis strategy, the polymer composite UV cutoff agent finally formed can simultaneously have UV cutoff, free radical quenching and good mechanical properties. This comprehensive performance improvement gives it a significant advantage in the light stabilization application of organic UV cutoff agents.

[0029] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description and the drawings.

[0030] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 Schematic diagram of the synthesis route of the copolymeric polymer triazine type UV cut-off agent provided in the embodiments of the present disclosure;

[0033] Figure 2 Schematic diagram of the synthesis route of the organic-inorganic composite polymer UV cutoff agent provided in the embodiments of the present disclosure;

[0034] Figure 3 A comparison chart of the UV aging transmittance of the EVA films of the embodiment and comparative example provided in the embodiments of the present disclosure;

[0035] Figure 4 This is a comparison chart of the UV aging data of the EVA films provided in the embodiments of the present disclosure and the comparative examples. DETAILED DESCRIPTION

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0037] As used herein, the phrases "in one embodiment," "according to one embodiment," "in some embodiments," and the like generally refer to the fact that the particular feature, structure, or characteristic following the phrase may be included in at least one embodiment of the present disclosure. Thus, a particular feature, structure, or characteristic may be included in more than one embodiment of the present disclosure, such that these phrases do not necessarily refer to the same embodiment. As used herein, the terms "example," "exemplary," and the like are used to "serve as an example, instance, or illustration." Any implementation, aspect, or design described herein as "example" or "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations, aspects, or designs. Instead, the use of the terms "example," "exemplary," and the like is intended to present concepts in a concrete manner.

[0038] Herein, example embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. As used herein, expressions such as "at least one of..." when following a list of elements modify the entire list of elements, rather than modifying individual elements in the list. For example, the expression "at least one of a, b, and c" should be understood to include only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.

[0039] The terms used herein are only used to describe specific exemplary configurations and are not intended to be limiting. As used herein, the singular articles "a", "an" and "the" may also be intended to include plural forms, unless otherwise clearly indicated herein. The terms "comprise", "include" and "have" are inclusive and therefore specify the presence of features, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components and / or combinations thereof. The method steps, processes and operations described herein should not be interpreted as necessarily requiring them to be performed in the particular order discussed or shown, unless specifically identified as an execution order. Additional or alternative steps may be adopted.

[0040] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0041] Some embodiments of the present application will be described in detail with reference to the drawings. The following embodiments and features of the embodiments described below can be combined with each other in the case of no conflict.

[0042] The present application provides a kind of ultraviolet cut-off agent, the ultraviolet cut-off agent is compound VI, specifically three kinds of copolymer ultraviolet cut-off agent, its chemical structural formula is

[0043]

[0044] Specifically, the compound VI of the present application is a high molecular composite ultraviolet light cut-off agent with multiple functions and excellent performance. The unique molecular structure of the cut-off agent combines the functions of ultraviolet cut-off and free radical capture, and can efficiently play the role of light stabilization. And by increasing the molecular weight of the ultraviolet absorber, the migration loss rate of the ultraviolet absorber is reduced. In addition, the hydrophilic effect of PEG macromolecule and the alkyl molecular chain are ingeniously combined in the molecule, effectively overcoming the shortcomings of traditional low molecular ultraviolet absorbers.

[0045] In a second aspect, the present application also provides a kind of ultraviolet cut-off agent, the ultraviolet cut-off agent is compound VII, specifically organic-inorganic composite high molecular ultraviolet cut-off agent with dopamine as shell and TiO2 / copolymer as core, its chemical structural formula is

[0046]

[0047] Specifically, the compound VII of the present application is an organic-inorganic composite ultraviolet light cut-off agent. The cut-off agent combines the advantages of organic and inorganic ultraviolet absorbers, and TiO2 inorganic metal oxide has a wider light absorption range and stronger ultraviolet absorption effect than other oxides. By using PDA and TiO2 particles, ultraviolet light absorbers are combined at the molecular level, which can quickly consume the photo-generated carriers on the surface of TiO2 to help TiO2 dissipate the absorbed ultraviolet light energy, synergistically enhance the anti-ultraviolet performance, and effectively reduce the migration rate of the ultraviolet absorber.

[0048] In a third aspect, the present disclosure also provides a method for preparing a UV cutoff agent, comprising the following steps: S1, stirring cyanuric chloride, resorcinol, a Lewis acid catalyst, and a solvent, 1,2-dichloroethane, and then heating the mixture for reaction. After the reaction is completed, the solid is filtered to obtain a solid, which is then washed with hydrochloric acid and dried to obtain a solid compound I; S2, stirring compound I, triethylamine, and tetrahydrofuran at low temperature, and adding acryloyl chloride dropwise thereto. After the reaction is completed, the mixture is precipitated in ice water, and the precipitate is recrystallized with ethanol to obtain a solid compound II; S3, mixing compound II, methyl chloroformate, sodium bicarbonate, and toluene, and then heating and refluxing the mixture. After the reaction is completed, the solid is pressurized and filtered to collect the solid, and then slurried with n-heptane. Dry to obtain compound III; S4, stir compound III, N,N-dimethylformamide and potassium carbonate evenly, then place in an oil bath and heat, then add isooctane bromide dropwise, reflux reaction after the addition is complete, and after the reaction is completed, extract, distill under reduced pressure and recrystallize, and dry to obtain compound IV; S5, stir compound IV, polyethylene glycol 400, methanesulfonic acid and toluene solution, heat and reflux reaction, after the reaction is completed, distill under reduced pressure, collect the solid, and dry to obtain compound V; S6, stir compound V, MTMP, KH-571 and toluene solution and initiator azobisisobutyronitrile, heat reaction under nitrogen atmosphere, precipitate with petroleum ether after the reaction is completed, collect the solid, and dry to obtain compound VI.

[0049] In some embodiments, specifically, the following steps are also included: S7, dissolving compound VI and titanic acid in dichloromethane, and adding HCl dropwise, then adding dopamine hydrochloride and stirring, adding H2O2 and mixing, transferring the mixed reactants to a hydrothermal reactor, heating for reaction, filtering after the reaction is completed, washing with ethanol, collecting the solid, and finally drying to obtain compound VII, that is, an organic-inorganic composite polymer UV cutoff agent.

[0050] See also Figure 1 and Figure 2 ,like Figure 1 As shown in FIG. , it is the reaction synthesis formula of step S1 to step S6, and the final synthesis product is compound VI, such as Figure 2 As shown, it is the reaction synthesis formula of step S7, and the final synthesis product is compound VII.

[0051] In some embodiments, specifically, the Lewis acid catalyst is one of aluminum trichloride, ferric trichloride, zinc chloride, boron trifluoride, and ferric tribromide, and the molar ratio of cyanuric chloride, resorcinol, and Lewis acid catalyst in step S1 is 1:3:3, the heating temperature is 80-100°C, and the reaction time is 6-8h.

[0052] In some embodiments, specifically, in step S2, the molar ratio of compound I, acryloyl chloride, and triethylamine is 1:1:1, the heating temperature is 0-5° C., and the reaction time is 6-8 h.

[0053] In some embodiments, specifically, in step S3, the molar ratio of compound II, methyl chloroformate, and sodium bicarbonate is 1:1:1, the heating temperature is 60-100° C., and the reaction time is 4-8 h.

[0054] In some embodiments, specifically, in step S4, the molar ratio of compound III, isooctane bromide, and potassium carbonate is 1:1.2:1.5, the heating temperature is 70-120° C., and the reaction time is 2-6 h.

[0055] In some embodiments, specifically, in step S5, the molar ratio of compound IV, polyethylene glycol 400, and methanesulfonic acid is 1:2:0.1, the heating temperature is 80-100° C., and the reaction time is 12-24 h.

[0056] In some embodiments, specifically, in step S6, the molar ratio of compound V, MTMP, KH-571, and initiator azobisisobutyronitrile is 1:1:1:0.1, the heating temperature is 60-100° C., and the reaction time is 12-24 h.

[0057] In a fourth aspect, the embodiments of the present disclosure also provide a method for preparing an EVA encapsulating film, comprising the following steps: S11, mixing, putting the UV cutoff agent as described above into a mixer with EVA resin and other additives for mixing and stirring to obtain a mixed raw material; S12, extrusion, pouring the mixed raw material into a single-screw extruder, and obtaining an extrudate through melt blending, discharge casting, and roller cooling; S13, film forming, measuring the thickness of the extrudate, pressing the edge, shaping, and then trimming and winding to obtain an EVA encapsulating film.

[0058] Specifically, the present invention provides a UV-cutting anti-reflective EVA encapsulating film and a method for preparing the same. This polymer composite UV cutoff agent has excellent compatibility with polymer materials and can be evenly dispersed therein, improving the mechanical properties of the encapsulating film, thereby significantly improving the weather resistance and stability of the material. At the same time, it avoids damage to the substrate EVA film by ultraviolet light, which has great practical significance. Suitable for the packaging needs of various photovoltaic modules, the UV-cutting anti-reflective EVA encapsulating film can effectively protect the cells and increase the overall service life of the photovoltaic module after being applied to the photovoltaic module.

[0059] In some embodiments, specifically, the mixed raw materials include the following raw materials in parts by mass: 100 parts of EVA resin, 0.8-2 parts of cross-linking agent, 0.3-2 parts of auxiliary cross-linking agent, 0.3-1 parts of coupling agent, 0.1-0.5 parts of antioxidant, 0.1-0.5 parts of light stabilizer, and 0.1-5 parts of UV cut-off agent.

[0060] In some embodiments, specifically, the cross-linking agent includes any one or more combinations of tert-amyl peroxy (2-ethylhexyl) carbonate, tert-butyl peroxy carbonate-2-ethylhexyl, diisopropyl peroxide, lauroyl peroxide, tert-butyl peroxyisopropyl carbonate, 2,5-dimethyl-2,5-bis (tert-butylperoxy) hexane, diisopropyl ditert-butyl peroxide, and 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane.

[0061] In some embodiments, specifically, the auxiliary cross-linking agent includes any one or more combinations of triallyl isocyanurate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, trimethylolpropane triacrylate, polyethylene glycol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, and propoxylated pentaerythritol tetraacrylate.

[0062] In some embodiments, specifically, the coupling agent includes any one or more combinations of vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltri(β-methoxyethoxy)silane, vinyltriisopropylsilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane.

[0063] In some embodiments, specifically, the antioxidant includes any one or more combinations of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris(2,4-di-tert-butylphenyl) phosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and N,N-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine.

[0064] In some embodiments, specifically, the light stabilizer includes any one or more combinations of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, mono(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinethanol) succinate, and 3,5-di-tert-butyl-4-hydroxy-benzoic acid hexadecyl ester.

[0065] The embodiment of the present disclosure also provides an EVA encapsulation film, which meets the following conditions: the transmittance of the EVA encapsulation film in the 290-320nm band is less than 10% and the transmittance in the 340-380nm band is greater than 80%; the transmittance of the EVA encapsulation film in the 380-1100nm band is greater than 92%.

[0066] The embodiment of the present disclosure also provides a photovoltaic module, comprising a glass layer, an EVA encapsulation film layer, a solar TOPCon cell sheet, and an EVA encapsulation film layer arranged in sequence; wherein the EVA encapsulation film layer adopts the EVA encapsulation film described above.

[0067] In some embodiments, specifically, a single-glass component and a double-glass component are included; the single-glass component comprises, from top to bottom, a glass layer, an EVA encapsulation film layer, a TOPCon battery cell, an EVA encapsulation film layer, and a backplane; the double-glass component comprises, from top to bottom, a glass layer, an EVA encapsulation film layer, a TOPCon battery cell, an EVA encapsulation film layer, and a glass layer.

[0068] Example 1

[0069] The components are calculated in parts by weight: 100 parts of ethylene vinyl acetate; 1.5 parts of tert-butyl peroxy-2-ethylhexyl carbonate as a crosslinking agent; 0.3 parts of triallyl isocyanurate as a co-crosslinking agent; 0.8 parts of γ-methacryloyloxypropyltrimethoxysilane as a silane coupling agent; 0.5 parts of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate as an antioxidant; 0.3 parts of bis(2,2,6,6-tetramethylpiperidinyl) sebacate as a light stabilizer; and 0.1 parts of an organic-inorganic composite polymer UV cutoff agent.

[0070] The preparation method of the organic-inorganic composite polymer UV cut-off agent is as follows:

[0071] S1. Place cyanuric chloride, resorcinol, a Lewis acid catalyst, and 1,2-dichloroethane in a round-bottom flask, stir well, and heat to react. After the reaction is complete, filter the solid, wash it with hydrochloric acid, and dry it to obtain solid Compound I.

[0072] Specifically, the molar ratio of cyanuric chloride, resorcinol and aluminum chloride is 1:3:3, the heating temperature is 90° C. and the reaction time is 6 hours.

[0073] S2. Compound I, triethylamine, and tetrahydrofuran are placed in a round-bottom flask and stirred at low temperature. Acryloyl chloride is slowly added dropwise and the reaction is continued. After the reaction is complete, the mixture is precipitated in ice water and the precipitate is recrystallized from ethanol to obtain solid Compound II.

[0074] Specifically, the molar ratio of compound I, acryloyl chloride and triethylamine is 1:1:1, the heating temperature is 0°C, and the reaction time is 8 hours.

[0075] S3. Compound II, methyl chloroformate, sodium bicarbonate, and toluene are placed in a round-bottom flask, stirred, and then heated under reflux for reaction. After the reaction is complete, the mixture is pressure-distilled and filtered to collect the solid, which is then slurried with n-heptane and dried to obtain Compound III.

[0076] Specifically, the molar ratio of compound II, methyl chloroformate, and sodium bicarbonate is 1:1:1, the heating temperature is 60° C., and the reaction time is 5 hours.

[0077] In step S4, compound III, N,N-dimethylformamide, and potassium carbonate were added to a round-bottom flask and stirred thoroughly. The mixture was then heated in an oil bath. Isooctane bromide was then added dropwise. After the addition was complete, the mixture was refluxed. After the reaction was complete, the mixture was extracted, distilled under reduced pressure, recrystallized, and finally dried to obtain compound IV.

[0078] Specifically, the molar ratio of compound III, isooctane bromide, and potassium carbonate is 1:1.2:1.5, the heating temperature is 110° C., and the reaction time is 4 hours.

[0079] S5. Compound IV, polyethylene glycol 400, methanesulfonic acid, and toluene solution are added to a round-bottom flask, stirred evenly, and then heated under reflux for reaction. After the reaction is complete, pressure distillation is performed, the solid is collected, and finally dried to obtain compound V.

[0080] Specifically, the molar ratio of compound IV, polyethylene glycol 400, and methanesulfonic acid is 1:2:0.1, the heating temperature is 90° C., and the reaction time is 16 h.

[0081] In step S6, compound V, 4-(methacryloyloxy)-2,2,6,6-tetramethylpiperidinol ester (MTMP), γ-methacryloyloxypropyltrimethoxysilane (KH-570), a toluene solution, and the initiator azobisisobutyronitrile were added to a round-bottom flask and stirred thoroughly. The mixture was then heated under a nitrogen atmosphere to react. After the reaction, the mixture was precipitated with petroleum ether, the solid was collected, and finally dried to yield compound VI, a copolymerized polymer UV cutoff agent.

[0082] Specifically, the molar ratio of compound V, 4-methacryloyloxy 2,2,6,6-tetramethylpiperidinol ester (MTMP), γ-methacryloyloxypropyltrimethoxysilane (KH-570), and initiator azobisisobutyronitrile is 1:1:1:0.1, the heating temperature is 70° C., and the reaction time is 12 h.

[0083] In step S7, compound VI and titanic acid are dissolved in dichloromethane, and HCl is added dropwise. Dopamine hydrochloride is then added and stirred. H₂O₂ is added and mixed. The mixture is transferred to a hydrothermal reactor and heated for reaction. After the reaction is complete, the solid is filtered, washed with ethanol, collected, and dried to obtain compound VII, an organic-inorganic composite polymer UV cutoff agent with a dopamine shell and a TiO₂ / copolymer core.

[0084] Specifically, the volume ratio of titanic acid, dichloromethane, HCl, and H2O2 is 1:5:2:0.025; further, the mass ratio of compound VI and dopamine hydrochloride is 0.2:1, the heating temperature is 170°C, and the reaction time is 4 hours.

[0085] According to the weight components of the film, the materials are taken and mixed evenly using an automatic mixer. The film is then extruded using a screw machine to form a film with a thickness of 0.5 mm and a weight of 380 g / m 2 UV cut-off anti-reflective EVA encapsulation film.

[0086] Example 2

[0087] The preparation method of the organic-inorganic composite polymer UV cut-off agent is the same as that in Example 1.

[0088] The components are calculated in parts by weight: 100 parts of ethylene vinyl acetate; 1.5 parts of tert-butyl peroxy-2-ethylhexyl carbonate as a crosslinking agent; 0.3 parts of triallyl isocyanurate as a co-crosslinking agent; 0.8 parts of γ-methacryloxypropyltrimethoxysilane as a silane coupling agent; 0.5 parts of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate as an antioxidant; 0.3 parts of bis(2,2,6,6-tetramethylpiperidinyl) sebacate as a light stabilizer; and 0.2 parts of an organic-inorganic composite polymer UV cutoff agent.

[0089] According to the weight components of the film, the materials are taken and mixed evenly using an automatic mixer. The film is then extruded using a screw machine to form a film with a thickness of 0.5 mm and a weight of 380 g / m 2 UV cut-off anti-reflective EVA encapsulation film.

[0090] Example 3

[0091] The preparation method of the organic-inorganic composite polymer UV cut-off agent is the same as that in Example 1.

[0092] The components are calculated in parts by weight: 100 parts of ethylene vinyl acetate; 1.5 parts of tert-butyl peroxy-2-ethylhexyl carbonate as a crosslinking agent; 0.3 parts of triallyl isocyanurate as a co-crosslinking agent; 0.8 parts of γ-methacryloyloxypropyltrimethoxysilane as a silane coupling agent; 0.5 parts of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate as an antioxidant; 0.3 parts of bis(2,2,6,6-tetramethylpiperidinyl) sebacate as a light stabilizer; and 0.3 parts of an organic-inorganic composite polymer UV cutoff agent.

[0093] According to the weight components of the film, the materials are taken and mixed evenly using an automatic mixer. The film is then extruded using a screw machine to form a film with a thickness of 0.5 mm and a weight of 380 g / m 2 UV cut-off anti-reflective EVA encapsulation film.

[0094] Example 4

[0095] The preparation method of the organic-inorganic composite polymer UV cut-off agent is the same as that in Example 1.

[0096] The components are calculated in parts by weight: 100 parts of ethylene vinyl acetate; 1.5 parts of tert-butyl peroxy-2-ethylhexyl carbonate as a crosslinking agent; 0.3 parts of triallyl isocyanurate as a co-crosslinking agent; 0.8 parts of γ-methacryloyloxypropyltrimethoxysilane as a silane coupling agent; 0.5 parts of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate as an antioxidant; 0.1 parts of bis(2,2,6,6-tetramethylpiperidinyl) sebacate as a light stabilizer; and 0.2 parts of an organic-inorganic composite polymer UV cutoff agent.

[0097] According to the weight components of the film, the materials are taken and mixed evenly using an automatic mixer. The film is then extruded using a screw machine to form a film with a thickness of 0.5 mm and a weight of 380 g / m 2 UV cut-off anti-reflective EVA encapsulation film.

[0098] Comparative Example 1

[0099] The components are calculated in parts by weight: 100 parts of ethylene vinyl acetate; 1.5 parts of tert-butyl peroxy-2-ethylhexyl carbonate as a crosslinking agent; 0.3 parts of triallyl isocyanurate as a co-crosslinking agent; 0.8 parts of γ-methacryloyloxypropyltrimethoxysilane as a silane coupling agent; 0.5 parts of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate as an antioxidant; and 0.1 parts of bis(2,2,6,6-tetramethylpiperidinyl) sebacate as a light stabilizer.

[0100] According to the weight components of the film, the materials are taken and mixed evenly using an automatic mixer. The film is then extruded using a screw machine to form a film with a thickness of 0.5 mm and a weight of 380 g / m 2 EVA packaging film.

[0101] Comparative Example 2

[0102] The components are calculated in parts by weight: 100 parts of ethylene vinyl acetate; 1.5 parts of tert-butyl peroxy-2-ethylhexyl carbonate as a crosslinking agent; 0.3 parts of triallyl isocyanurate as a co-crosslinking agent; 0.8 parts of γ-methacryloyloxypropyltrimethoxysilane as a silane coupling agent; 0.5 parts of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate as an antioxidant; and 0.2 parts of an organic-inorganic composite polymer UV cutoff agent.

[0103] According to the weight components of the film, the materials are taken and mixed evenly using an automatic mixer. The film is then extruded using a screw machine to form a film with a thickness of 0.5 mm and a weight of 380 g / m 2 EVA packaging film.

[0104] Comparative Example 3

[0105] The components are calculated in parts by weight: 100 parts of ethylene vinyl acetate; 1.5 parts of tert-butyl peroxy-2-ethylhexyl carbonate as a crosslinking agent; 0.3 parts of triallyl isocyanurate as a co-crosslinking agent; 0.8 parts of γ-methacryloyloxypropyltrimethoxysilane as a silane coupling agent; 0.5 parts of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate as an antioxidant; 0.1 parts of bis(2,2,6,6-tetramethylpiperidinyl) sebacate as a light stabilizer; and 0.2 parts of an organic polymer UV cutoff agent.

[0106] The preparation method of the organic polymer ultraviolet cut-off agent is as follows:

[0107] S1. Place cyanuric chloride, resorcinol, a Lewis acid catalyst, and 1,2-dichloroethane in a round-bottom flask, stir well, and heat to react. After the reaction is complete, filter the solid, wash it with hydrochloric acid, and dry it to obtain solid Compound I.

[0108] Specifically, the molar ratio of cyanuric chloride, resorcinol and aluminum chloride is 1:3:3, the heating temperature is 90° C. and the reaction time is 6 hours.

[0109] S2. Compound I, triethylamine, and tetrahydrofuran are placed in a round-bottom flask and stirred at low temperature. Acryloyl chloride is slowly added dropwise and the reaction is continued. After the reaction is complete, the mixture is precipitated in ice water and the precipitate is recrystallized from ethanol to obtain solid Compound II.

[0110] Specifically, the molar ratio of compound I, acryloyl chloride and triethylamine is 1:1:1, the heating temperature is 0°C, and the reaction time is 8 hours.

[0111] S3. Compound II, methyl chloroformate, sodium bicarbonate, and toluene are placed in a round-bottom flask, stirred, and then heated under reflux for reaction. After the reaction is complete, the mixture is pressure-distilled and filtered to collect the solid, which is then slurried with n-heptane and dried to obtain Compound III.

[0112] Specifically, the molar ratio of compound II, methyl chloroformate, and sodium bicarbonate is 1:1:1, the heating temperature is 60° C., and the reaction time is 5 hours.

[0113] In step S4, compound III, N,N-dimethylformamide, and potassium carbonate were added to a round-bottom flask and stirred thoroughly. The mixture was then heated in an oil bath. Isooctane bromide was then added dropwise. After the addition was complete, the mixture was refluxed. After the reaction was complete, the mixture was extracted, distilled under reduced pressure, recrystallized, and finally dried to obtain compound IV.

[0114] Specifically, the molar ratio of compound III, isooctane bromide, and potassium carbonate is 1:1.2:1.5, the heating temperature is 110° C., and the reaction time is 4 hours.

[0115] S5. Compound IV, polyethylene glycol 400, methanesulfonic acid, and toluene solution are added to a round-bottom flask, stirred evenly, and then heated under reflux for reaction. After the reaction is complete, pressure distillation is performed, the solid is collected, and finally dried to obtain compound V.

[0116] Specifically, the molar ratio of compound IV, polyethylene glycol 400, and methanesulfonic acid is 1:2:0.1, the heating temperature is 90° C., and the reaction time is 16 h.

[0117] In step S6, compound V, 4-(methacryloyloxy)-2,2,6,6-tetramethylpiperidinol ester (MTMP), γ-methacryloyloxypropyltrimethoxysilane (KH-570), a toluene solution, and the initiator azobisisobutyronitrile were added to a round-bottom flask and stirred thoroughly. The mixture was then heated under a nitrogen atmosphere to react. After the reaction, petroleum ether was used for precipitation, and the solid was collected and dried to yield compound VI, a copolymerized organic polymer UV cutoff agent.

[0118] Specifically, the molar ratio of compound V, 4-methacryloyloxy 2,2,6,6-tetramethylpiperidinol ester (MTMP), γ-methacryloyloxypropyltrimethoxysilane (KH-570), and initiator azobisisobutyronitrile is 1:1:1:0.1, the heating temperature is 70° C., and the reaction time is 12 h.

[0119] S7, dissolving compound VI in dichloromethane, adding HCl dropwise, then adding dopamine hydrochloride with stirring, adding H2O2 and mixing, transferring the mixture to a hydrothermal reactor and heating for reaction. After the reaction is complete, filtering, washing with ethanol, collecting the solid, and finally drying to obtain compound VIII, a polymeric UV cutoff agent with a dopamine shell and a copolymer core.

[0120] Specifically, the volume ratio of dichloromethane, HCl, and H2O2 is 5:2:0.025, the mass ratio of compound VI and dopamine hydrochloride is 0.2:1, the heating temperature is 170°C, and the reaction time is 4 hours.

[0121] According to the weight components of the film, the materials are taken and mixed evenly using an automatic mixer. The film is then extruded using a screw machine to form a film with a thickness of 0.5 mm and a weight of 380 g / m 2 EVA packaging film.

[0122] Comparative Example 4

[0123] The components are calculated in parts by weight: 100 parts of ethylene vinyl acetate; 1.5 parts of tert-butyl peroxy-2-ethylhexyl carbonate as a crosslinking agent; 0.3 parts of triallyl isocyanurate as a co-crosslinking agent; 0.8 parts of γ-methacryloyloxypropyltrimethoxysilane as a silane coupling agent; 0.5 parts of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate as an antioxidant; 0.1 parts of bis(2,2,6,6-tetramethylpiperidinyl) sebacate as a light stabilizer; and 0.2 parts of an inorganic UV cutoff agent.

[0124] The preparation method of the inorganic ultraviolet cut-off agent is as follows:

[0125] Titanic acid was dissolved in dichloromethane, and HCl was added dropwise. Dopamine hydrochloride was then added and stirred. H₂O₂ was added and mixed. The mixture was transferred to a hydrothermal reactor and heated to react. After the reaction was completed, the solid was filtered, washed with ethanol, and collected. Finally, it was dried to obtain Compound VII, an inorganic UV cutoff agent with a dopamine shell and a TiO₂ core.

[0126] Specifically, the volume ratio of titanic acid, dichloromethane, HCl, and H2O2 is 1:5:2:0.025, the mass of dopamine hydrochloride is 1, the heating temperature is 170°C, and the reaction time is 4 hours.

[0127] According to the weight components of the film, the materials are taken and mixed evenly using an automatic mixer. The film is then extruded using a screw machine to form a film with a thickness of 0.5 mm and a weight of 380 g / m 2 EVA packaging film.

[0128] Comparative Example 5

[0129] The components are calculated in parts by weight: 100 parts of ethylene vinyl acetate; 1.5 parts of tert-butyl peroxy-2-ethylhexyl carbonate as a crosslinking agent; 0.3 parts of triallyl isocyanurate as a co-crosslinking agent; 0.8 parts of γ-methacryloyloxypropyltrimethoxysilane as a silane coupling agent; 0.5 parts of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate as an antioxidant; 0.1 parts of bis(2,2,6,6-tetramethylpiperidinyl) sebacate as a light stabilizer; and 0.2 parts of a UV cutoff agent.

[0130] The UV cut-off agent is a triazine UV cut-off agent of a certain brand sold online, which is a white powder sample.

[0131] According to the weight components of the film, the materials are taken and mixed evenly using an automatic mixer. The film is then extruded using a screw machine to form a film with a thickness of 0.5 mm and a weight of 380 g / m 2 EVA packaging film.

[0132] The EVA films obtained in Examples 1-4 of the present invention and Comparative Examples 1-5 were respectively subjected to sample preparation and relevant performance tests. The sample preparation process and test methods are as follows:

[0133] Sample preparation: The cast film is sampled and then hot-pressed at 145°C for 16 minutes to obtain a laminated film sample. Furthermore, the glass, EVA encapsulation film, and solar cells are assembled in this order from top to bottom, and laminated at 145°C for 16 minutes to create a module.

[0134] Light transmittance test: After lamination, test the light transmittance of the film samples according to the test method specified in GB / T 29848-2018. The UV spectrophotometer wavelength range was set to 290–1100 nm, and the average light transmittance of each wavelength was calculated. Three samples were tested per group, and the average of the test results was taken.

[0135] Solar cell module power test: Prepare test samples in accordance with the standard of GB / T29848-2018 and perform photovoltaic module current and voltage tests.

[0136] UV aging test: Place the laminated film samples and double-glass components into a UV aging test chamber for irradiation. The UV wavelength of the test chamber is distributed between 280 and 400 nm. The surface temperature of the sample in the test chamber is maintained at 60 ± 5 ° C. The test time is measured by the cumulative dose of irradiation power, 60 to 180 kWh / m 2 The yellowing index and light transmittance of the samples were measured before and after the UV aging test. The power of the components was tested before and after the UV aging test.

[0137] The EVA films obtained in Examples 1-4 of the present invention and Comparative Examples 1-5 were tested for relevant properties, and the test results are shown in Tables 1 and 2:

[0138] Table 1 Experimental data of examples and comparative examples

[0139]

[0140] Conclusion: The data from Examples 1-4 and Comparative Examples 1-5 in Table 1 above demonstrate that during the encapsulation process, the crosslinking agent promotes the formation of crosslinks between EVA molecular chains, thereby improving the film's mechanical strength and heat resistance. By combining antioxidants, light stabilizers, and UV cutoff agents, the EVA film's antioxidant and UV resistance, as well as its optical properties, can be simultaneously enhanced. This comprehensive performance improvement results in greater stability and durability for EVA films used in photovoltaic module encapsulation.

[0141] From a comprehensive comparison, the organic-inorganic composite polymer UV cutoff agent produced by this technical solution not only has a lower UV transmittance, but also has a lower component attenuation power. By optimizing the types and contents of the additives and UV cutoff agents in the formula, the combination of the organic-inorganic composite polymer UV cutoff agent and the light stabilizer in Example 4 shows a more significant performance advantage. It has a relatively good UV cutoff function and can achieve a lower transmittance in the ultraviolet band of 290-320nm and a higher transmittance in the ultraviolet band of 340-380nm. At the same time, the transmittance of the film in the visible light band of 380-1100nm is greater than 92%.

[0142] Table 2 UV aging test data of examples and comparative examples

[0143]

[0144] Specifically, such as Figure 3 and Figure 4 As shown, Figure 3 From left to right under each UV irradiation amount are the transmittance corresponding to 290~320nm, 320nm, 320~340nm, 340nm, 340~380nm and 380~1100nm. Figure 4 From left to right under each UV irradiation amount are Example 4, Comparative Example 1 and Comparative Example 5, where UV20 refers to an ultraviolet irradiation dose of 20 kWh / m 2 .

[0145] Conclusion: The data of Example 4, Comparative Example 1 and Comparative Example 5 in Table 2 above show that in the UV accelerated aging experiment, the transmittance change and yellowing change of EVA films with different formulations are monitored. The UV cut-off agent produced by this technical solution undergoes UV aging at 60kWh / m 2After monitoring, the UV cutoff effect remains good, and the yellowing change value is low. The UV absorber in this patent, when used in a certain ratio, can further reduce yellowing after UV aging and improve weather resistance. This further demonstrates that it can effectively reduce UV damage to photovoltaic modules, extending the module's service life and performance stability.

[0146] In summary, the present organic-inorganic composite polymer UV cutoff agent, preparation method, and encapsulating film first design a novel triazine UV cutoff agent. Using a triazine compound as the backbone, the structure is modified at various sites to introduce a PEG macromolecular hydrophilic chain and an alkoxy molecular chain. This is then copolymerized with hindered amine structural units (2,2,6,6-tetramethylpiperidinol) and methacryloyloxypropyltriethoxysilane) via solution copolymerization to form a polymer composite cutoff agent with multiple functions and excellent performance. Finally, with titanic acid and dopamine hydrochloride as raw materials, a polydopamine-coated TiO2 and triazine UV cutoff agent organic-inorganic polymer composite cutoff agent is prepared. Through the above design and synthesis strategy, the resulting polymer composite UV cutoff agent simultaneously exhibits UV cutoff, free radical quenching, and excellent mechanical properties. This improved overall performance gives it a significant advantage in the light stabilization application of organic UV cutoff agents.

[0147] With the above-described preferred embodiments of the present invention as inspiration, and with reference to the above description, relevant personnel are fully capable of making various changes and modifications without departing from the technical scope of this invention. The technical scope of this invention is not limited to the contents of the specification and must be determined according to the scope of the claims.

Claims

1. A UV cut-off agent, characterized in that, The UV cut-off agent is compound VI, specifically three copolymerized polymer UV cut-off agents, whose chemical structure is 2. A UV cut-off agent, characterized in that, The UV cutoff agent is compound VII, specifically an organic-inorganic composite polymer UV cutoff agent with dopamine as the shell and TiO2 / copolymer as the core, and its chemical structure is 3. A method for preparing a UV cut-off agent, characterized in that: The steps include: S1, stirring cyanuric chloride, resorcinol, a Lewis acid catalyst, and a solvent, 1,2-dichloroethane, and heating them for reaction. After the reaction is completed, filtering to obtain a solid, washing it with hydrochloric acid, and drying it to obtain a solid compound I; S2, stirring compound I, triethylamine, and tetrahydrofuran at low temperature, and adding acryloyl chloride dropwise thereto, and precipitating in ice water after the reaction is completed. The precipitate is recrystallized from ethanol to obtain solid compound II; S3, mixing compound II, methyl chloroformate, sodium bicarbonate, and toluene, and then heating and refluxing the mixture. After the reaction is complete, pressurize and distill the mixture, filter, collect the solid, slurry the solid with n-heptane, and dry the solid to obtain compound III. S4, mixing compound III, N,N-dimethylformamide, and potassium carbonate, then heating in an oil bath, then adding isooctane bromide dropwise, and reflux reaction after the addition is complete. After the reaction is complete, extraction, vacuum distillation, recrystallization, and drying are performed to obtain compound IV; S5, stirring compound IV, polyethylene glycol 400, methanesulfonic acid, and toluene solution, heating and refluxing the mixture, and performing pressure distillation after the reaction is completed. The solid is collected and dried to obtain compound V; S6, compound V, MTMP, KH-571, toluene solution and initiator azobisisobutyronitrile are stirred and heated under a nitrogen atmosphere for reaction. After the reaction is completed, petroleum ether is used for precipitation, and the solid is collected and dried to obtain compound VI.

4. The preparation method of the ultraviolet cut-off agent as claimed in claim 3, wherein The following steps are also included: S7, dissolving compound VI and titanic acid in dichloromethane, and adding HCl dropwise, then adding dopamine hydrochloride and stirring, adding H2O2 and mixing, transferring the mixed reactants to a hydrothermal reactor, heating for reaction, filtering after the reaction, washing with ethanol, collecting the solid, and finally drying to obtain compound VII, i.e., an organic-inorganic composite polymer UV cutoff agent.

5. The preparation method according to claim 3, wherein The Lewis acid catalyst is one of aluminum trichloride, ferric trichloride, zinc chloride, boron trifluoride, and ferric tribromide, and the molar ratio of cyanuric chloride, resorcinol, and Lewis acid catalyst in step S1 is 1:3:3, the heating temperature is 80-100° C., and the reaction time is 6-8 hours; In step S2, the molar ratio of compound I, acryloyl chloride, and triethylamine is 1:1:1, the heating temperature is 0-5°C, and the reaction time is 6-8h; In step S3, the molar ratio of compound II, methyl chloroformate, and sodium bicarbonate is 1:1:1, the heating temperature is 60-100° C., and the reaction time is 4-8 hours; In step S4, the molar ratio of compound III, isooctane bromide, and potassium carbonate is 1:1.2:1.5, the heating temperature is 70-120° C., and the reaction time is 2-6 hours; In step S5, the molar ratio of compound IV, polyethylene glycol 400, and methanesulfonic acid is 1:2:0.1, the heating temperature is 80-100° C., and the reaction time is 12-24 h; In step S6, the molar ratio of compound V, MTMP, KH-571, and initiator azobisisobutyronitrile is 1:1:1:0.1, the heating temperature is 60-100° C., and the reaction time is 12-24 h.

6. A method for preparing an EVA encapsulation film, characterized in that: The steps include: S11, mixing, putting the UV cutoff agent according to any one of claims 1 or 2, EVA resin and other additives into a mixer, mixing and stirring to obtain a mixed raw material; S12, extrusion, pouring the mixed raw materials into a single-screw extruder, and performing melt blending, discharge casting, and cooling with a roller to obtain an extrudate; S13, film forming, the extruded material is subjected to thickness measurement, edge pressing, shaping, and then edge trimming and winding to obtain an EVA encapsulating film.

7. The preparation method according to claim 6, wherein The mixed raw materials include the following raw materials in parts by mass: 100 parts of EVA resin, 0.8-2 parts of cross-linking agent, 0.3-2 parts of auxiliary cross-linking agent, 0.3-1 part of coupling agent, 0.1-0.5 parts of antioxidant, 0.1-0.5 parts of light stabilizer, and 0.1-5 parts of UV cut-off agent.

8. The preparation method according to claim 7, wherein: The cross-linking agent includes any one or more combinations of tert-amyl peroxy (2-ethylhexyl) carbonate, tert-butyl peroxy carbonate-2-ethylhexyl, diisopropyl peroxide, lauroyl peroxide, tert-butyl peroxyisopropyl carbonate, 2,5-dimethyl-2,5-bis (tert-butylperoxy) hexane, diisopropyl ditert-butyl peroxide, and 1,1-di-tert-butylperoxy-3,3,5-trimethylcyclohexane; The auxiliary cross-linking agent includes any one or more combinations of triallyl isocyanurate, ethoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane triacrylate, trimethylolpropane triacrylate, polyethylene glycol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, ethoxylated pentaerythritol tetraacrylate, and propoxylated pentaerythritol tetraacrylate; The coupling agent includes any one or more combinations of vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, vinyltri(β-methoxyethoxy)silane, vinyltriisopropylsilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane; The antioxidant includes any one or more combinations of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]pentaerythritol, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tris(2,4-di-tert-butylphenyl) phosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol diphosphate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, and N,N-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine; The light stabilizer includes any one or more combinations of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, mono(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidinethanol) succinate, and 3,5-di-tert-butyl-4-hydroxy-benzoic acid hexadecyl ester.

9. An EVA encapsulation film, characterized in that: The EVA encapsulation film meets the following conditions: The light transmittance of the EVA encapsulation film in the 290-320 nm band is less than 10% and the light transmittance in the 340-380 nm band is greater than 80%; The light transmittance of the EVA packaging film in the wavelength range of 380 to 1100 nm is greater than 92%.

10. A photovoltaic module, characterized in that: It includes a glass layer, an EVA encapsulation film layer, a solar TOPCon cell sheet, and an EVA encapsulation film layer arranged in sequence; The EVA encapsulation film layer adopts the EVA encapsulation film as claimed in claim 8.

Images