Anti-PID EVA packaging adhesive film and preparation method and application thereof

Abstract

The invention relates to the technical field of photovoltaic packaging adhesive films, and discloses an anti-PID EVA packaging adhesive film and a preparation method and application thereof. The anti-PID EVA packaging adhesive film is prepared from the following raw materials in parts by weight: 100 parts of EVA resin, 0.1 to 1.5 parts of a cross-linking agent, 0.5 to 5 parts of an assistant cross-linking agent, 0 to 1 part of an antioxidant, 0.1 to 5 parts of a silane coupling agent, 0.01 to 5 parts of an inorganic anti-PID auxiliary agent and 0.01 to 1.5 parts of an organic anti-PID auxiliary agent, the inorganic anti-PID auxiliary agent is two-dimensional flaky modified hexagonal boron nitride powder; and the organic anti-PID auxiliary agent is a polyfunctional acrylate organic functional monomer. By introducing a small amount of the inorganic anti-PID auxiliary agent, the light transmittance and the mechanical property of the adhesive film can be improved, the volume resistivity of the adhesive film can be improved, the PID effect can be more effectively inhibited, and by cooperatively introducing the organic anti-PID auxiliary agent, the adhesive film has excellent tensile strength, light transmittance and anti-PID performance.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic encapsulation film technology, specifically to an anti-PID EVA encapsulation film, its preparation method, and its application. Background Technology

[0002] Potential-induced degradation (PID) in photovoltaic (PV) modules is a significant factor severely impacting the performance and lifespan of PV power plants. During prolonged operation, external voltage can induce leakage current within the PV module, leading to performance degradation. This PID degradation manifests primarily as a decrease in fill factor, open-circuit voltage, and short-circuit current, and in severe cases, can result in power loss exceeding 50%. PID is particularly pronounced in high-temperature and high-humidity environments, significantly affecting the overall performance and lifespan of PV power plants.

[0003] Ethylene-vinyl acetate (EVA) encapsulation film is a crucial encapsulation material in photovoltaic (PV) modules. It is primarily used to bond the front panel (such as PV glass), PV cells, and PV backsheet together to form a complete PV module. EVA encapsulation film effectively protects the PV cells and extends the module's lifespan while ensuring the module's light transmittance. However, traditional EVA encapsulation films are prone to hydrolysis under high temperature and humidity conditions, producing acetic acid. The reaction of acetic acid with sodium ions in the glass exacerbates the PID (Potential Inhibition) phenomenon, especially noticeable in TOPCon double-glass PV modules, where the PID caused by the EVA encapsulation film is particularly pronounced.

[0004] To address the PID problem in EVA encapsulation films, industry professionals have conducted extensive research. For example, CN109554141B, CN108778991B, and CN117887380A disclose methods such as adding ethylene-vinyl alcohol copolymers, ion scavengers, or aminated boron nitride as anti-PID additives to improve the anti-PID performance of the film. These methods reduce the likelihood of the film reacting with sodium ions in the glass to some extent, thus helping to improve the film's anti-PID performance. However, these methods still need further improvement in addressing the charge migration problem in photovoltaic encapsulation films, resulting in limited effectiveness in anti-PID applications for photovoltaic modules. Furthermore, excessive addition of these anti-PID additives can negatively impact the film's transmittance and mechanical properties (for instance, CN117887380A, in order to improve the anti-PID performance of EVA encapsulation films, uses an anti-PID filler—aminated boron nitride—with a mass percentage content of 10-25%, adding a large amount of anti-PID filler, which is detrimental to improving the film's transmittance and mechanical properties). Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an anti-PID EVA encapsulation film, its preparation method, and its application.

[0006] Based on this, the present invention discloses an anti-PID EVA encapsulating film, comprising the following raw materials in the following weight ratios: 100 parts of EVA resin (vinyl acetate copolymer), 0.1-1.5 parts of crosslinking agent, 0.5-5 parts of co-crosslinking agent, 0-1 part of antioxidant, 0.1-5 parts of silane coupling agent, 0.01-5 parts of inorganic anti-PID additive, and 0.01-1.5 parts of organic anti-PID additive; The inorganic anti-PID additive is a two-dimensional flake-shaped modified hexagonal boron nitride powder, which can effectively inhibit ion migration and improve the volume resistivity of the film. The organic anti-PID additive is a multifunctional acrylate organic functional monomer, which can improve the density of the polymer. Preferably, the VA content of the EVA resin is 26-30% (e.g., 28%), and the melt index is 25 g / 10 min (190°C, 2.16 kg).

[0007] Preferably, the modified hexagonal boron nitride powder has a purity of 98-99.5 wt% and an average particle size of 0.2-1.0 μm; the weight ratio of the EVA resin to the inorganic anti-PID additive is 100 parts: 0.5-1.5 parts.

[0008] More preferably, the modified hexagonal boron nitride powder has a purity of 99-99.5 wt% (more preferably 99 wt%) and an average particle size of 0.2-0.5 μm.

[0009] More preferably, the modified hexagonal boron nitride powder is a submicron two-dimensional lamellar hexagonal boron nitride powder. h The modified product is obtained by modifying (-BN); the modification is one or more of the following methods: hydroxylation (-OH), amination (-NH2), aminoation (-NHR), etherification (-OR), acylation (-COR), alkylation (-R), and carboxylation (-COOR) (more preferably aminoation or aminoation). This modification helps to improve... h - Compatibility and dispersibility of BN powder with EVA film.

[0010] The modifying agents used were boric acid, nitric acid, hydrogen peroxide, sodium hydroxide, polydopamine, urea, and di-tert-butyl peroxide. γ -aminopropyltriethoxysilane, γ -Methacryloxypropyltrimethoxysilane, aminopropyltriethoxysilane, tetraethyl silicate (more preferably urea or polydopamine).

[0011] Preferably, the organic anti-PID additive is a low-polarity multifunctional acrylate organic functional monomer, which is one or more of the following: trimethylolpropane triacrylate, bis(trimethylolpropane) acrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, polydipentaerythritol pentaacrylate, polydipentaerythritol hexaacrylate, propoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane trimethacrylate, and glyceryl trihydroxypropyl ether triacrylate (more preferably, a mixture of one or two of ethoxylated trimethylolpropane triacrylate and polydipentaerythritol hexaacrylate). These low-polarity multifunctional acrylate organic functional monomers can increase the density of the polymer, thereby improving the anti-PID performance of the film.

[0012] More preferably, the multifunctional acrylate organic functional monomer is a mixture of ethoxylated trimethylolpropane triacrylate and polydipentaerythritol hexaacrylate; The weight ratio of the EVA resin to the inorganic anti-PID additive is 100 parts: 0.5-1 parts.

[0013] Preferably, the crosslinking agent is one or more of benzoyl peroxide, dicumyl peroxide, tert-butyl percarbonate-2-ethylhexyl peroxide, tert-amyl peroxide-2-ethylhexyl carbonate, 2,5-di-tert-butyl peroxide-2,5-dimethylhexane, diisopropyl peroxide, dicyclohexyl peroxide, methyl ethyl ketone peroxide, and tert-butyl peroxide (more preferably tert-butyl percarbonate-2-ethylhexyl peroxide); these crosslinking agents can effectively initiate the crosslinking reaction of EVA resin.

[0014] The co-crosslinking agent is one or more of triallyl isocyanurate, trimethylolpropane trimethacrylate, diethylene glycol dimethacrylate, and triallyl cyanurate. These co-crosslinking agents can enhance the crosslinking effect of EVA resin.

[0015] Preferably, the antioxidant is one or more of the following: tris(nonylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, 2,2'-methylenebis-(4-methyl-6-tert-butylphenol), octadecyl 3,5-di-tert-butyl-4-hydroxyphenylpropionate, pentaerythritol tetra-(4-hydroxy-3,5-tert-butylphenylpropionate), and di(2,2,6,6-tetramethyl-4-piperidinyl) sebacate. The silane coupling agent is one or more of vinyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-glycidyl etheroxypropyltrimethoxysilane, and vinyltris(2-methoxyethoxy)silane. These silane coupling agents can further improve the compatibility and dispersibility of inorganic anti-PID additives with EVA resin, and enhance the adhesion between the encapsulant film and photovoltaic glass and photovoltaic cells.

[0016] This invention also discloses a method for preparing an anti-PID EVA encapsulating film, comprising the following preparation process: The EVA resin, crosslinking agent, co-crosslinking agent, antioxidant, silane coupling agent, inorganic anti-PID additive and organic anti-PID additive are mixed evenly and then cast and extruded to form a film, thus obtaining the anti-PID EVA encapsulation film.

[0017] The present invention also discloses an application of PID-resistant EVA encapsulating film, which is used as a front encapsulating film and / or a back encapsulating film in photovoltaic modules.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects: This invention provides an anti-PID EVA encapsulating film. Based on a certain amount of EVA resin, crosslinking agent, co-crosslinking agent, antioxidant, and silane coupling agent, a small amount of inorganic two-dimensional sheet-like modified hexagonal boron nitride powder is introduced as an inorganic anti-PID additive. With a low amount of this inorganic anti-PID additive, the light transmittance and mechanical properties (such as tensile strength) of the EVA encapsulating film can be improved, while simultaneously increasing the volume resistivity. Its low ion mobility can more effectively suppress the PID effect. Furthermore, a certain amount of organic anti-PID additive—a low-polarity, multifunctional acrylate organic functional monomer—is introduced, increasing the polymer density and further significantly reducing the PID effect. Therefore, the EVA encapsulating film of this invention possesses excellent tensile strength, light transmittance, weather resistance, and anti-PID performance, making it particularly suitable as a front-side encapsulating film for use in photovoltaic modules. Attached Figure Description

[0019] Figure 1 This is a transmission electron microscope (TEM) image of the inorganic anti-PID additive, hydroxylated hexagonal boron nitride, used in Example 5.

[0020] Figure 2 Transmission electron microscopy image of the inorganic anti-PID additive, ammoniated hexagonal boron nitride. Detailed Implementation

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to specific embodiments.

[0022] The hexagonal boron nitride used in the following embodiments of the present invention is the CPF series hexagonal boron nitride from 3M Company, USA.

[0023] Example 1 This embodiment provides a method for preparing an anti-PID EVA encapsulating film, comprising the following preparation steps: S1. Preparation of inorganic anti-PID additive: The inorganic anti-PID additive is amino-modified boron nitride with a purity of 99% and an average particle size of 0.5 μm.

[0024] The preparation process of the aminated boron nitride is as follows: 5g of boron nitride (i.e., two-dimensional plate-like hexagonal boron nitride powder) is added to deionized water and ultrasonically stirred for 2h to obtain a boron nitride mixture; then, the boron nitride mixture is dispersed in 400mL of 10mmol / L Tris (tris(hydroxymethyl)aminomethane) buffer solution with pH 8.5, stirred evenly, and then 800mg of dopamine hydrochloride is added to obtain a mixture; the mixture is magnetically stirred at room temperature for 6h to carry out a pretreatment modification reaction; after the reaction is completed, the sample is washed until neutral, dried at 60℃, and ground to obtain two-dimensional plate-like aminated hexagonal boron nitride powder (abbreviated as aminated boron nitride).

[0025] S2. Preparation of EVA encapsulating film: Add 0.8 parts tert-butyl peroxycarbonate-2-ethylhexyl ester, 0.7 parts triallyl isocyanurate, 0.15 parts di(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and 0.35 parts γ-glycidyl ether to 100 parts (by weight, the same below) of EVA resin particles (EVA resin with VA content of 28% and melt index of 25 g / 10 min (190℃, 2.16 kg). Oxypropyltrimethoxysilane, 0.5 parts of inorganic anti-PID additive (amined boron nitride), and 0.5 parts of organic anti-PID additive (wherein, the organic anti-PID additive is polydipentaerythritol hexaacrylate, which is a polyfunctional monomer and a polymerizable monomer) are mixed evenly and fed into a casting machine for plasticizing and extrusion at 75-85℃ (e.g., 80℃). Then, through stretching, traction, and winding processes, a 0.45mm thick anti-PID EVA encapsulation film is produced.

[0026] Example 2 This embodiment provides an anti-PID EVA encapsulating film and its preparation method, referring to Embodiment 1, but differing from Embodiment 1 in that: In this embodiment, the weight percentage of the inorganic anti-PID additive is changed to 1 part, and the organic anti-PID additive is changed to a mixture of ethoxylated trimethylolpropane triacrylate and polydipentaerythritol hexaacrylate in a 1:1 mass ratio. All other aspects are the same as in Example 1, thus obtaining an anti-PID EVA encapsulating film of this embodiment.

[0027] Example 3 This embodiment provides an anti-PID EVA encapsulating film and its preparation method, referring to Embodiment 1, but differing from Embodiment 1 in that: In this embodiment, the weight percentage of the inorganic anti-PID additive is changed to 1.5 parts. All other steps are the same as in Example 1, thus obtaining an anti-PID EVA encapsulating film according to this embodiment.

[0028] Example 4 This embodiment provides an anti-PID EVA encapsulating film and its preparation method, referring to Embodiment 1, but differing from Embodiment 1 in that: In this embodiment, the weight percentage of the inorganic anti-PID additive is changed to 1 part. All other parameters are the same as in Example 1, thus obtaining an anti-PID EVA encapsulation film according to this embodiment.

[0029] Example 5 This embodiment provides an anti-PID EVA encapsulating film and its preparation method, which differs from Embodiment 2 in that: In this embodiment, the inorganic anti-PID additive used is hydroxylated hexagonal boron nitride (abbreviated as hydroxylated boron nitride), with a purity of 99% and an average particle size of 0.5 μm. The preparation process of hydroxylated boron nitride includes the following steps: 5 g of two-dimensional flake-like hexagonal boron nitride powder is dispersed in an 8 mol / L NaOH solution using an ultrasonic disperser. The mixture is transferred to a reaction vessel and reacted at 140°C for 18 h. After the reaction, the mixture is centrifuged at 4000 r / min. The solid obtained from centrifugation is washed alternately with deionized water and anhydrous ethanol until neutral, then vacuum dried at 40°C and ball-milled for 6 h to obtain hydroxylated boron nitride powder. The remaining steps are the same as in Example 2, thus obtaining an anti-PID EVA encapsulation film of this embodiment.

[0030] Example 6 This embodiment provides an anti-PID EVA encapsulating film and its preparation method, which differs from Embodiment 2 in that: In this embodiment, the inorganic anti-PID additive used is aminated boron nitride with a purity of 99% and an average particle size of 0.5 μm. The preparation process of aminated boron nitride includes: mixing two-dimensional plate-like hexagonal boron nitride powder with urea at a mass ratio of 1:30, ball milling at 500 rpm for 20 h, centrifuging and washing until neutral, and drying at 80°C for 12 h to obtain aminated boron nitride. The rest of the process is the same as in Example 2, thus obtaining an anti-PID EVA encapsulation film of this embodiment.

[0031] Example 7 This embodiment provides an anti-PID EVA encapsulating film and its preparation method, which differs from Embodiment 2 in that: In this embodiment, the inorganic anti-PID additive used is still 99% pure aminated boron nitride, but its average particle size is 1 μm. All other aspects are the same as in Example 2, thus obtaining an anti-PID EVA encapsulation film of this embodiment.

[0032] Example 8 This embodiment provides an anti-PID EVA encapsulating film and its preparation method, which differs from Embodiment 2 in that: In this embodiment, the weight percentage of the organic anti-PID additive is changed to 1 part. All other parameters are the same as in Example 2, thus obtaining an anti-PID EVA encapsulating film according to this embodiment.

[0033] Example 9 This embodiment provides an anti-PID EVA encapsulating film and its preparation method, which differs from Embodiment 2 in that: In this embodiment, the weight percentage of the organic anti-PID additive was changed to 1.5 parts. All other steps were the same as in Example 2, resulting in an anti-PID EVA encapsulation film according to this embodiment.

[0034] Example 10 This embodiment provides an anti-PID EVA encapsulating film and its preparation method, referring to Embodiment 4, but differing from Embodiment 4 in that: In this embodiment, the organic anti-PID additive used is ethoxylated trimethylolpropane triacrylate. All other aspects are the same as in Example 4, thus obtaining an anti-PID EVA encapsulating film according to this embodiment.

[0035] Comparative Example 1 This comparative example provides an anti-PID EVA encapsulating film and its preparation method, referring to Example 2, but differing from Example 2 in that: In this comparative example, no inorganic anti-PID additive was added, and the weight percentage of the organic anti-PID additive was changed to 1.5 parts (that is, the total weight percentage of the anti-PID additive remained unchanged, but only the organic anti-PID additive was added, and no inorganic anti-PID additive was added). All other steps were the same as in Example 2, thus obtaining an anti-PID EVA encapsulating film for this comparative example.

[0036] Comparative Example 2 This comparative example provides an anti-PID EVA encapsulating film and its preparation method, referring to Example 2, but differing from Example 2 in that: In this comparative example, no organic anti-PID additive was added, and the weight percentage of the inorganic anti-PID additive was changed to 1.5 parts (that is, the total weight percentage of the anti-PID additive remained unchanged, but only the inorganic anti-PID additive was added, and no organic anti-PID additive was added). All other steps were the same as in Example 2, thus obtaining an anti-PID EVA encapsulating film for this comparative example.

[0037] Comparative Example 3 This comparative example provides an anti-PID EVA encapsulating film and its preparation method, referring to Example 2, but differing from Example 2 in that: In this comparative example, neither inorganic nor organic anti-PID additives were added.

[0038] Performance testing The physical properties of the EVA encapsulating films prepared in Examples 1-10 and Comparative Examples 1-3 were tested using the following methods: (1) Light transmittance and crosslinking degree: Tested in accordance with standard GB / T 29848-2013 "Ethylene-vinyl acetate copolymer (EVA) film for photovoltaic module encapsulation".

[0039] (2) Tensile strength: Tested in accordance with standard GB / T 1040.1-2024.

[0040] (3) Volume resistivity: Tested in accordance with standard GB / T31838.2-2019.

[0041] (4) PID power degradation: The PID test of the photovoltaic module was carried out in accordance with the standard IEC-61215. The photovoltaic module includes a photovoltaic front panel (photovoltaic glass), a front encapsulation film (which is the EVA encapsulation film prepared in the above embodiment or comparative example), a photovoltaic cell, a back encapsulation film (commercially available high-transparency EVA encapsulation film) and a photovoltaic back sheet (photovoltaic glass) stacked from top to bottom.

[0042] The test results are shown in Table 1 below: Table 1

[0043] As can be seen from the data in Table 1: (1) The EVA encapsulating films of each embodiment of the present invention all possess excellent tensile strength, light transmittance, weather resistance, and anti-PID performance (volume resistivity and PID 192h power attenuation can characterize anti-PID performance). Among them, the EVA encapsulating film of Example 2 has superior overall performance (especially its anti-PID performance). (2) Comparing the test data of Examples 2, 5, and 6 with those of Comparative Examples 1-3, it can be seen that compared with EVA encapsulation films without anti-PID additives (such as Comparative Example 3), the introduction of both inorganic anti-PID additives (such as Comparative Example 2) and organic anti-PID additives (such as Comparative Example 1) helps to improve the anti-PID performance of EVA encapsulation films. When inorganic and organic anti-PID additives are used in combination (such as Examples 2, 5, and 6), the anti-PID performance of EVA encapsulation films is significantly better than that of EVA encapsulation films with only organic or inorganic anti-PID additives added, such as Comparative Example 1 or Comparative Example 2. On the one hand, the introduction of inorganic anti-PID additives can improve the overall volume resistivity of the film to a certain extent, which has an inhibitory effect on charge migration. Therefore, after introducing a certain amount of modified two-dimensional boron nitride (i.e., inorganic anti-PID additives), the overall anti-PID performance of the film is significantly improved. In particular, the modified boron nitride has good compatibility with EVA resin particles, avoiding performance degradation caused by local defects inside the film. On the other hand, boron nitride itself is a material with high thermal conductivity, which can effectively prevent local thermal stress concentration inside the film from accelerating the aging of local weak points, which is not available in conventional EVA encapsulation films. Secondly, the introduction of organic anti-PID additives also increases the overall polymer density of the EVA encapsulation film, which can be reflected in the improvement of tensile strength, further enhancing the anti-PID performance of the EVA encapsulation film.

[0044] Furthermore, compared to Examples 5 and 6 (Example 5 is used in combination with, for example...), Figure 1 The EVA encapsulating film obtained by using hydroxylated boron nitride (as shown in Example 6, and aminolated boron nitride in Example 2) with the organic anti-PID additive in Example 2 (an inorganic anti-PID additive) has better overall performance (especially the tensile strength and anti-PID performance of Example 2).

[0045] (3) Comparing the test data of Examples 1, 3, and 4 (the weight parts of inorganic anti-PID additives in Examples 1, 4, and 3 are 0.5 parts, 1 part, and 1.5 parts, respectively), it can be seen that: more inorganic anti-PID additives are not necessarily better. When the content of inorganic powder is too high, it will affect the light transmittance and mechanical properties (such as tensile strength) of the EVA encapsulation film, which is not conducive to further improving the anti-PID performance of the EVA encapsulation film.

[0046] Comparing the test data of Examples 2 and 7 (both with 99% purity and average particle sizes of 0.5 μm and 1 μm, respectively), it can be seen that for the inorganic anti-PID additive—modified two-dimensional boron nitride—higher purity and smaller particle size (as shown in Example 2) result in better anti-PID performance of the EVA encapsulation film. Furthermore, it should be noted that when the particle size of the modified two-dimensional boron nitride is too small (less than 0.2 μm, e.g., ...), ... Figure 2 When the surface area increases (as shown), it becomes more prone to aggregation, making dispersion in EVA encapsulation films difficult and easily leading to stress defects, which negatively impacts mechanical properties and light transmittance. For example... Figure 1-2 As shown, the sheet-like modified two-dimensional boron nitride has a particle size in the micrometer or even nanometer range. This was determined by transmission electron microscopy. Figure 1 It can be seen that the inorganic anti-PID additive used in Example 5, hydroxylated boron nitride, has a two-dimensional layered structure with a particle size distribution of 300-700 nm and an average particle size of 0.5 μm. Figure 2 The particle size distribution of the amino-modified boron nitride is 100-250 nm, and its average particle size is less than 0.2 μm.

[0047] (4) Comparing the test data of Examples 2, 4, and 10 (the organic anti-PID additives used in Examples 2, 4, and 10 were respectively: ethoxylated trimethylolpropane triacrylate and polydipentaerythritol hexaacrylate mixed in a mass ratio of 1:1, polydipentaerythritol hexaacrylate alone, and ethoxylated trimethylolpropane triacrylate alone), it can be seen that for multifunctional organic anti-PID additives, the combination of acrylate-type organic anti-PID additives with different functionalities, such as ethoxylated trimethylolpropane triacrylate and polydipentaerythritol hexaacrylate (as shown in Example 2), has a more significant comprehensive performance (such as light transmittance, tensile strength, and anti-PID performance) than using a single multifunctional acrylate-type organic anti-PID additive (such as in Examples 4 and 10). Furthermore, low-functionality organic anti-PID additives have less steric hindrance, making it easier for them to fully participate in the reaction within the film components; while high-functionality organic anti-PID additives have greater steric hindrance but more reaction sites, which helps to improve the overall density of the film; and the combination of acrylate-based organic anti-PID additives with different functionalities combines the advantages of both, which can further improve the density of the film itself, thereby achieving a higher anti-PID effect.

[0048] Comparing the test data of Examples 2, 8, and 9 (the weight parts of the organic anti-PID additives in Examples 2, 8, and 9 were 0.5 parts, 1 part, and 1.5 parts, respectively), we also found that after the content of multifunctional organic anti-PID additives reaches a certain level, it will not further improve the anti-PID performance of the EVA encapsulation film. This indicates that the method of improving the film density and anti-PID performance by increasing organic anti-PID additives has certain limitations. This is also an important reason why this invention chooses to use a combination of inorganic and organic anti-PID additives to improve the anti-PID performance of the EVA encapsulation film.

[0049] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present invention.

[0050] The technical solution provided by the present invention has been described in detail above. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A PID-resistant EVA encapsulant film, characterized in that, The raw materials include the following weight ratio: EVA resin 100 parts, crosslinking agent 0.1-1.5 parts, auxiliary crosslinking agent 0.5-5 parts, antioxidant 0-1 part, silane coupling agent 0.1-5 parts, inorganic anti-PID additive 0.01-5 parts and organic anti-PID additive 0.01-1.5 parts; The inorganic anti-PID additive is a modified hexagonal boron nitride powder in a two-dimensional sheet shape; and the organic anti-PID additive is a multifunctional acrylate organic functional monomer.

2. The PID-resistant EVA encapsulant film according to claim 1, wherein, The purity of the modified hexagonal boron nitride powder is 98-99.5 wt%, and the average particle size is 0.2-1.0 μm; and the weight ratio of the EVA resin to the inorganic anti-PID additive is 100:0.5-1.

5.

3. The PID-resistant EVA encapsulant film according to claim 2, wherein, The purity of the modified hexagonal boron nitride powder is 99-99.5 wt%, and the average particle size is 0.2-0.5 μm.

4. The anti-PID EVA encapsulating film according to any one of claims 1-3, characterized in that, The modified hexagonal boron nitride powder is obtained by modifying a submicron two-dimensional sheet-shaped hexagonal boron nitride powder; and the modification method is one or more of hydroxylation, amination, amine group, etherification, acylation, alkylation and carboxylation. The modifying treatment aids used are boric acid, nitric acid, hydrogen peroxide, sodium hydroxide, polydopamine, urea, di-tert-butyl peroxide, The organic anti-PID additive is a low-polarity multifunctional acrylate organic functional monomer, which is one or more of trimethylolpropane triacrylate, ditrimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, polydi-pentaerythritol pentaacrylate, polydi-pentaerythritol hexaacrylate, propoxylated trimethylolpropane triacrylate, propoxylated trimethylolpropane trimethacrylate and glyceryl trihydroxypropyl ether triacrylate. - aminopropyltriethoxysilane, The multifunctional acrylate organic functional monomer is a mixture of ethoxylated trimethylolpropane triacrylate and polydi-pentaerythritol hexaacrylate. - one or several of methacryloyloxypropyltrimethoxysilane, aminopropyltriethoxysilane, tetraethyl silicate.

5. The PID-resistant EVA encapsulant film according to claim 1, wherein, The weight ratio of the EVA resin to the inorganic anti-PID additive is 100:0.5-1.

6. The PID-resistant EVA encapsulant film according to claim 5, wherein, The crosslinking agent is one or more of benzoyl peroxide, dicumyl peroxide, tert-butyl peroxy-2-ethylhexyl carbonate, tert-amyl peroxy-2-ethylhexyl carbonate, 2,5-di-tert-butyl peroxy-2,5-dimethylhexane, diisopropyl peroxydicarbonate, dicyclohexyl peroxydicarbonate, methyl ethyl ketone peroxide and tert-butyl peroxybenzoate; The auxiliary crosslinking agent is one or more of triallyl isocyanurate, trimethylolpropane trimethacrylate, diethylene glycol dimethacrylate and triallyl cyanurate.

7. The PID-resistant EVA encapsulant film according to claim 1, wherein, The antioxidant is one or more of tris(nonylphenyl)phosphite, tris(2,4-di-tert-butylphenyl)phosphite, 2,2'-methylenebis-(4-methyl-6-tert-butylphenol), 3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate, tetra-(4-hydroxy-3,5-di-tert-butylphenylpropionate) pentaerythritol, and bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate. ​ 8. The PID-resistant EVA encapsulant film according to claim 1, wherein, ​ The silane coupling agent is one or more of vinyl trimethoxysilane, γ-aminopropyl triethoxysilane, γ-methacryloyloxypropyl trimethoxysilane, γ-mercaptopropyl trimethoxysilane, γ-glycidyloxypropyl trimethoxysilane, and vinyl tri(2-methoxyethoxy)silane.

9. A method for preparing an anti-PID EVA encapsulating film according to any one of claims 1-8, characterized in that, The preparation process comprises the following steps: The formula amount of EVA resin, crosslinking agent, crosslinking aid, antioxidant, silane coupling agent, inorganic PID-resistant additive, and organic PID-resistant additive are uniformly mixed, and then extruded into a film to obtain the PID-resistant EVA packaging adhesive film.

10. The use of an EVA encapsulant film against PID according to any one of claims 1 to 8, characterized in that, The PID-resistant EVA packaging adhesive film is applied to the photovoltaic module as the front packaging adhesive film and / or the back packaging adhesive film.

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