Photovoltaic barrier film with humidity and heat resistance and preparation method thereof

Abstract

The invention relates to a photovoltaic barrier film with humidity and heat resistance and a preparation method thereof, and belongs to the technical field of solar photovoltaics. The photovoltaic barrier film comprises a base material layer, a characteristic barrier layer, a protective layer and a transition layer, the protective layer comprises 60-90 parts of a first linear polymer, 10-30 parts of a curing agent, 1-10 parts of a first auxiliary agent and 50-100 parts of a solvent; the transition layer comprises 60-90 parts of a second linear polymer, 10-30 parts of epoxy acrylic resin, 10-30 parts of a diluent, 1-10 parts of a nano filler and 1-10 parts of a second auxiliary agent; the molecular weight of the epoxy acrylic resin is 100 to 1000; the molecular weight of the first linear polymer and the second linear polymer is 100-1000, and the glass transition temperature is 80 DEG C or above. The photovoltaic barrier film has a good effect on improving the humidity and heat resistance of a photovoltaic module or a back film, and can improve the overall reliability and prolong the service life of a photovoltaic system.

Description

Technical Field

[0001] The invention belongs to the technical field of solar photovoltaics, and in particular relates to a photovoltaic barrier film with moisture and heat resistance and a preparation method thereof. Background Art

[0002] With the continuous growth of global energy demand and the improvement of environmental awareness, solar photovoltaic technology, as a clean and renewable energy utilization method, has attracted more and more attention. However, in practical applications, the efficiency of photovoltaic cells is often affected by environmental factors, among which the hot and humid environment is an important factor.

[0003] Most of the protection failures of outdoor products known to mankind, such as corrosion, failure of optoelectronic devices, and attenuation of photovoltaic cells, are mainly the result of the interaction between water vapor and oxygen and other conditions. At present, water-oxygen barrier materials are mainly barrier film products. There are three main production processes for barrier films: aluminum film / aluminum-plated film, aluminum-oxide-plated film, and silicon-oxide-plated film. These three barrier films are made by composite or vacuum coating on plastic base films such as PET or BOPP to produce a layer of water-oxygen barrier film to achieve water-oxygen barrier effect. Among them, silicon-oxide-plated film has high water-oxygen barrier, high transparency, and resistance to moisture and heat, and is the first choice for high-end packaging materials.

[0004] With the development of science and technology, more and more high-end products have been developed, but at the same time, it also brings extremely high requirements for packaging materials; for example, the requirements for packaging materials of quantum dot display screens and high-efficiency solar cell modules are that the water vapor transmission rate (WVTR) is less than or equal to 0.03 g / m 2 .d -1 and less than or equal to 0.05 g / m 2 .d -1 ; Such a high barrier rate requires very high equipment and technology. Currently, few companies can produce it. On the other hand, the production cost of the product is very high and ordinary users cannot afford it. These two factors have seriously hindered the development of high-end products. Therefore, it is still urgent to develop a photovoltaic barrier film with high moisture and heat resistance that can meet the needs of high-end products and has a reasonable cost. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a photovoltaic barrier film with moisture and heat resistance and a preparation method thereof. Through the use of linear polymers, structural design and process optimization, a photovoltaic barrier film with moisture and heat resistance that can meet the requirements of current optoelectronic product packaging is prepared; it is weather-resistant to high temperature and high humidity in the external environment. The photovoltaic barrier film can maintain stable performance for a long time in a high temperature and high humidity environment, can resist adverse effects such as ultraviolet chemical corrosion, and ensure that photovoltaic modules can operate normally in various climates.

[0006] The first object of the present invention is to provide a photovoltaic barrier film with moisture and heat resistance, comprising a substrate layer, a characteristic barrier layer, a protective layer and a transition layer; the characteristic barrier layer is arranged on the substrate layer; the protective layer is arranged on the characteristic barrier layer; wherein the transition layer is located between the substrate layer and the characteristic barrier layer, or the transition layer is located between the characteristic barrier layer and the protective layer, or the transition layer is located on the protective layer; The protective layer comprises, by weight: 60-90 parts of a first linear polymer, 10-30 parts of a curing agent, 1-10 parts of a first auxiliary agent, and 50-100 parts of a solvent; The transition layer comprises, by weight, 60-90 parts of a second linear polymer, 10-30 parts of an epoxy acrylic resin, 10-30 parts of a diluent, 1-10 parts of a nanofiller, and 1-10 parts of a second auxiliary agent; the epoxy acrylic resin has a molecular weight of 100-1000 and has excellent low shrinkage and weather resistance; The molecular weight of the first linear polymer and the second linear polymer are independently 100-1000, and the glass transition temperature is independently above 80°C; The first linear polymer and the second linear polymer are independently selected from one or more of a polyurethane polymer, an acrylic polymer, a silicone polymer and an epoxy polymer; And / or, the first linear polymer and the second linear polymer are independently aliphatic resins containing acrylate at the end groups and hydroxyl groups on the molecular chains, and have excellent toughness, wear resistance and elasticity.

[0007] In one embodiment of the present invention, the curing agent is selected from one or more of water, amide curing agents, peroxide curing agents, organic acid curing agents and alkyl silicate curing agents.

[0008] In one embodiment of the present invention, the solvent is selected from alcohol solvents and / or ketone solvents; the diluent is ethyl acetate; the nanofiller is selected from inorganic silicon oxides and / or inorganic silicates, with a particle size of 20 nm-200 nm, to improve the moisture and heat resistance and mechanical properties of the photovoltaic barrier film.

[0009] In one embodiment of the present invention, the first auxiliary agent and the second auxiliary agent are independently selected from one or more of a leveling agent, an adhesion promoter and a light stabilizer.

[0010] Furthermore, the leveling agent is selected from one or more of an acrylic leveling agent, a silicone leveling agent and a fluorocarbon leveling agent; the adhesion promoter is a Yunqing brand adhesion promoter; and the light stabilizer is a light stabilizer BW-10LD.

[0011] In one embodiment of the present invention, the material of the characteristic barrier layer is a silicon-oxygen compound, wherein the molecular formula of the silicon-oxygen compound is Si a O b , b:a=1-2; the thickness of the characteristic barrier layer is 2 nm-300 nm, preferably 10 nm-100 nm, for example, it can be 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, etc.; if the characteristic barrier layer is too thin, the molecular coverage is poor, which affects the barrier rate; if the characteristic barrier layer is too thick, the risk of brittle fracture of the coating will be increased, affecting the use effect; the silicon oxide compound can be directly obtained through the target material, or it can be obtained by chemical reaction in the chamber of the coating equipment.

[0012] In one embodiment of the present invention, the material of the substrate layer is selected from one or more of polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polypropylene, polyethylene, polyamide, polyimide, polycarbonate, polyvinyl chloride, polystyrene, polyacrylate, polyvinyl fluoride, polyvinylidene fluoride, triacetate and ethylene-tetrafluoroethylene copolymer; the thickness of the substrate layer is 2 μm-400 μm, preferably 6 μm-150 μm, the elongation at break is more than 200%, and the elongation at break is more than 40% when treated for 1000 h under 85 ° C and 85% Rh conditions. The selection of the substrate layer mainly follows three principles: first, it provides basic water and oxygen molecule barrier properties and has good bonding with other structures on the photovoltaic barrier film; second, it meets the use requirements of downstream customers for products in different scenarios; and third, it meets the basic requirements of the industry for materials.

[0013] The second object of the present invention is to provide a method for preparing the photovoltaic barrier film with moisture and heat resistance, wherein the preparation of the characteristic barrier layer comprises the following steps: preparing the characteristic barrier layer on the surface of the film layer by using vacuum coating technology; wherein the film layer is a layer structure arranged below the characteristic barrier layer; The preparation of the protective layer comprises the following steps: coating a protective layer slurry on the surface of the film layer and drying to form a protective layer; the protective layer slurry is obtained by adding a first linear polymer, a curing agent and a first auxiliary agent into a solvent and mixing them uniformly; wherein the film layer is a layer structure arranged below the protective layer; The preparation of the transition layer includes the following steps: coating a transition layer slurry on the surface of the film layer and forming the transition layer through electron beam curing; the transition layer slurry is obtained by adding a second linear polymer, epoxy acrylic resin, nanofiller and a second auxiliary agent into a diluent and mixing them evenly; wherein the film layer is a layer structure arranged below the transition layer.

[0014] In one embodiment of the present invention, the vacuum coating method is selected from vacuum evaporation coating and / or vacuum sputtering coating; the process parameters of the vacuum evaporation coating are: the vacuum degree is 1 Pa-10 Pa, for example, it can be 1 Pa, 2 Pa, 3 Pa, 4 Pa, 5 Pa, 6 Pa, 7 Pa, 8 Pa, 9 Pa, 10 Pa, etc.; the bombardment voltage is 0.2 kV-1 kV negative high voltage, for example, it can be 0.2 kV, 0.3 kV, 0.4 kV, 0.5 kV, 0.6 kV, 0.7 kV, 0.8 kV, 0.9 kV, 1 kV, etc.; the bombardment time is 5min-10 min, for example, it can be 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, etc.; the process parameters of the vacuum sputtering coating are: the vacuum degree is 1 Pa-10 Pa, for example, it can be 1 Pa, 2 Pa, 3 Pa, 4 Pa, 5 Pa, 6 Pa, 7 Pa, 8 Pa, 9 Pa, 10 Pa, etc.; the deposition rate is 0.1 μm / min-5 μm / min, and the sputtering rate is 0.01 μm / min-0.5 μm / min, for example, it can be 0.1 μm / min, 0.5 μm / min, 1 μm / min, 1.5 μm / min, 2 μm / min, 2.5 μm / min, 3μm / min, 3.5 μm / min, 4 μm / min, 4.5 μm / min, 5 μm / min, etc., which can greatly reduce production costs and improve production efficiency; the advantages of vacuum evaporation coating are simple production process, relatively low cost and high production efficiency; the advantages of vacuum sputtering coating are high coating purity, good film uniformity and good bonding with substrate.

[0015] In one embodiment of the present invention, the coating method is selected from one or more of micro-gap coating, slit coating and screen printing.

[0016] In one embodiment of the present invention, the irradiation current of the electron beam curing is 1.8 mA-2.2 mA, for example, it can be 1.8 mA, 1.9 mA, 2.0 mA, 2.1 mA, 2.2 mA, etc.; the temperature is 20 ℃-30 ℃, for example, it can be 20 ℃, 21 ℃, 22 ℃, 23 ℃, 24 ℃, 25 ℃, 26 ℃, 27 ℃, 28 ℃, 29 ℃, 30 ℃, etc.; compared with traditional thermal curing or ultraviolet curing, electron beam curing is faster and shorter in time, and can quickly provide high energy to quickly cure the material, thereby improving production efficiency. It can also be operated continuously without waiting for cooling or drying time, further improving production efficiency; in addition, electron beam curing is uniform. The UV (ultraviolet light) curing commonly used now has a shorter light wave, and the penetration and accessible depth will decay with the thickness, thereby causing uneven curing. When using electron beam curing, electrons will produce a series of cross-linking reactions after entering the material, and the curing is more uniform.

[0017] In one embodiment of the present invention, the step of pretreating the substrate layer is also included; the pretreatment method is selected from one or more of chemical etching treatment, plasma treatment, molecular coupling treatment, radiation treatment and base film co-extrusion modification treatment; the pretreatment can improve the post-processing performance of the base film and the overall performance of the functional film, provide good base film adhesion for subsequent work processes and cover up defects on the base film surface.

[0018] The technical solution of the present invention has the following advantages over the prior art: The material of the characteristic barrier layer in the photovoltaic barrier film described in the present invention is a silicon oxide compound, which has extremely high water vapor barrier properties and can effectively prevent oxygen from penetrating into the interior of the photovoltaic module through tiny pores, thereby protecting the battery cells and circuits from damage.

[0019] The substrate layer in the photovoltaic barrier film of the present invention provides stable support; the characteristic barrier layer prevents the penetration of water vapor and oxygen through physical and chemical effects; the transition layer can connect the layers to each other to further improve the durability and mechanical strength of the photovoltaic barrier film, so that it can better withstand changes in the external environment and the influence of stress; the protective layer can form a dense protective layer. Through the gradual improvement and mutual coordination of the multi-layer protective structure, the product can cope with the challenges of various harsh environmental conditions to a limited extent, protect photovoltaic modules from damage by water vapor and humidity, and the cost is only one-third of that of traditional manufacturing processes. In addition to moisture and heat resistance, the photovoltaic barrier film also has good weather resistance and can resist adverse effects such as ultraviolet chemical corrosion.

[0020] The synergistic effect between the components and processes of the photovoltaic barrier film of the present invention has a good effect on the product. In the photovoltaic field, it has a relatively good effect on improving the moisture and heat resistance of photovoltaic modules or back films, and can improve the overall reliability and service life of photovoltaic systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic structural diagram of a photovoltaic barrier film with moisture and heat resistance according to Example 1 of the present invention; Explanation of reference numerals: 1 - protective layer, 2 - transition layer, 3 - characteristic barrier layer, 4 - substrate layer. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. It should be understood that the specific embodiments are only used to explain the present invention, but the embodiments are not intended to limit the present invention.

[0023] In the present invention, unless otherwise defined, technical and scientific terms used in the present invention have the same meanings as commonly understood by those skilled in the art to which the present invention belongs.

[0024] In the present invention, unless otherwise stated, the term "and / or" used in the present invention includes any and all combinations of one or more of the associated listed items.

[0025] In the present invention, unless otherwise stated, the experimental methods used in the embodiments of the present invention are conventional methods unless otherwise stated, and the materials, reagents, etc. used are all commercially available unless otherwise stated.

[0026] In the present invention, unless otherwise stated, when the terms "comprise" and / or "include" are used in the specification of the present invention, it indicates the existence of the described features, integers, steps, operations, raw materials or components, but does not exclude the existence or addition of one or more other features, integers, steps, operations, raw materials, components or their combinations.

[0027] In the present invention, unless otherwise specified, the raw materials used can be commercially available products.

[0028] The commercial information of some materials involved in the following examples and comparative examples is as follows: The polyethylene terephthalate base film was purchased from Changzhou Huarun, model number is cr-8863; The linear polymer is a polyurethane polymer purchased from Wanhua, model 7110J3, molecular weight 989.321, and glass transition temperature 80 °C; Epoxy acrylic resin was purchased from Lankelu, model number L-61111, molecular weight 484.538; The particle size of nanofiller silica is about 100 nm; The auxiliary leveling agent is an acrylic leveling agent, model BYK-333. Example 1

[0029] Reference Figure 1 As shown, the photovoltaic barrier film with moisture and heat resistance of this embodiment includes a substrate layer 4, a characteristic barrier layer 3, a transition layer 2 and a protective layer 1 which are stacked in sequence from bottom to top.

[0030] Among them, the material of the characteristic barrier layer is silicon oxide compound Si a O b , b:a=1; The transition layer is composed of the following components in parts by weight: 60 parts of linear polymer, 10 parts of epoxy acrylic resin, 20 parts of diluent ethyl acetate, 5 parts of nano filler silica, and 5 parts of auxiliary leveling agent; The protective layer is composed of the following components in parts by weight: 60 parts of a linear polymer, 10 parts of a curing agent, toluene diisocyanate, 5 parts of an auxiliary leveling agent, and 80 parts of a solvent, acetone.

[0031] The preparation of a photovoltaic barrier film having moisture and heat resistance specifically comprises the following steps: S1, treatment of the substrate layer: plasma treatment is performed on one side of a polyethylene terephthalate base film having a thickness of 23 μm; S2. Preparation of characteristic barrier layer: a silicon oxide layer with a thickness of 50 nm is deposited by vacuum evaporation coating to obtain a characteristic barrier layer; wherein the process parameters of vacuum evaporation coating are: vacuum degree of 5 Pa, bombardment voltage of 0.6 kV negative high voltage, and bombardment time of 8 min; S3, preparation of transition layer: firstly, the linear polymer and epoxy acrylic resin are dissolved in a diluent, nano fillers and auxiliary leveling agents are added, and the mixture is evenly mixed to obtain a transition layer slurry; then, the transition layer slurry is coated on the surface of the characteristic barrier layer by a micro-concave coating method, and the transition layer is formed by electron beam curing under the conditions of an irradiation current of 2 mA and a temperature of 25 °C; S4. Preparation of protective layer: firstly, the linear polymer is dissolved in solvent acetone, and a curing agent, toluene diisocyanate, and an auxiliary agent, a leveling agent, are added, and the mixture is evenly mixed to obtain a protective layer slurry; then, the protective layer slurry is coated on the surface of the transition layer by a micro-concave coating method, and the mixture is cured in an oven at a temperature of 50°C for 48 hours to form a protective layer, thereby obtaining a photovoltaic barrier film with moisture and heat resistance. Example 2

[0032] The method is basically the same as Example 1, except that the material of the substrate layer is replaced with a polyacrylate base film. Example 3

[0033] The method is basically the same as Example 1, except that the preparation method of the characteristic barrier layer is replaced by vacuum sputtering coating; wherein the process parameters of the vacuum sputtering coating are: vacuum degree of 5 Pa, deposition rate of 2.5 μm / min, and sputtering rate of 2.5 μm / min. Example 4

[0034] The method is basically the same as Example 1, except that the transition layer is disposed between the substrate layer and the characteristic barrier layer. Example 5

[0035] The method is basically the same as the first embodiment, except that the transition layer is disposed on the protective layer. Comparative Example 1

[0036] The method is basically the same as Example 1, except that no characteristic barrier layer is provided. Comparative Example 2

[0037] The method is basically the same as the first embodiment, except that no transition layer is provided. Comparative Example 3

[0038] The method is basically the same as the first embodiment, except that no protective layer is provided. Comparative Example 4

[0039] The method is basically the same as Example 1, except that the linear polymer is replaced by phenolic resin. Comparative Example 5

[0040] The method is basically the same as Example 1, except that the silicon oxide compound of the characteristic barrier layer is replaced by barium fluoride. Test Case

[0041] The water vapor transmission rate and oxygen transmission rate of the photovoltaic barrier films prepared in Examples 1-5 and Comparative Examples 1-5 were tested: Water vapor transmission rate: sampler cutting; place sample; set sample name, temperature to 38 ℃, humidity to 90% rh; start test; save data; Oxygen transmission rate: sampler cutting; place sample; set sample name and temperature to 24 ℃; start test; save data; Aging time: Sample preparation (the number of samples in each test section of A4 sample is 3); set the temperature to 85 ℃ and the humidity to 85%; start the test; save the data; Table 1 shows the relevant properties of the photovoltaic barrier film finally measured: Table 1

[0042] It can be seen from Table 1 that the photovoltaic barrier film of the embodiment has excellent barrier properties and can effectively prevent water vapor and moisture penetration; has good weather resistance and can resist harsh environments such as ultraviolet rays, high temperature, and high humidity; has excellent chemical stability and can resist chemical corrosion; has a long service life and can significantly improve the reliability and service life of photovoltaic modules; the photovoltaic barrier film can maintain stable performance in various harsh environments and adapt to a wider range of photovoltaic application scenarios.

[0043] By comparing Example 1 and Comparative Example 1, it can be seen that the water vapor permeability and oxygen permeability without the characteristic barrier layer are significantly doubled, proving that the characteristic barrier layer can form a dense and stable barrier to effectively prevent the penetration of water vapor and moisture.

[0044] By comparing Example 1 and Comparative Example 2, it can be seen that the water vapor permeability and oxygen permeability are also significantly increased without the transition layer, which has a greater impact on the oxygen permeability.

[0045] By comparing Example 1 and Comparative Example 3, it can be seen that the water vapor permeability and oxygen permeability are also significantly increased without the protective layer, and the protective layer needs to be reinforced.

[0046] By comparing Example 1 and Comparative Example 4, it can be seen that when the linear polyurethane is replaced with phenolic resin, the water vapor permeability and oxygen permeability are also significantly increased, and the linear polyurethane material has good water and oxygen barrier properties.

[0047] By comparing Example 1 and Comparative Example 5, it can be seen that by replacing the silicon oxide compound in the characteristic barrier layer with fluoride, the water vapor transmission rate and oxygen transmission rate are significantly doubled, and fluoride is not suitable for this structure.

[0048] In summary, the photovoltaic barrier film of the present invention can resist hot and humid environments and chemical corrosion, significantly extend the service life of photovoltaic modules, reduce the frequency of replacement and maintenance, thereby helping to reduce maintenance costs and improve the overall economic benefits of the photovoltaic system. In addition, this photovoltaic barrier film is suitable for various types of photovoltaic modules, including silicon-based photovoltaic modules, thin-film photovoltaic modules, etc. It can be directly applied to the surface of photovoltaic modules, or used together with the packaging materials of photovoltaic modules to provide comprehensive protection for photovoltaic modules. With the continuous development of solar energy technology, this photovoltaic barrier film will be more widely used and make important contributions to the sustainable development of the solar photovoltaic industry.

[0049] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A photovoltaic barrier film having moisture and heat resistance, characterized in that: The invention comprises a substrate layer, a characteristic barrier layer, a protective layer and a transition layer; the characteristic barrier layer is arranged on the substrate layer; the protective layer is arranged on the characteristic barrier layer; wherein the transition layer is located between the substrate layer and the characteristic barrier layer, or the transition layer is located between the characteristic barrier layer and the protective layer, or the transition layer is located on the protective layer; The protective layer comprises, by weight: 60-90 parts of a first linear polymer, 10-30 parts of a curing agent, 1-10 parts of a first auxiliary agent, and 50-100 parts of a solvent; The transition layer comprises, by weight, 60-90 parts of a second linear polymer, 10-30 parts of an epoxy acrylic resin, 10-30 parts of a diluent, 1-10 parts of a nanofiller, and 1-10 parts of a second auxiliary agent; the molecular weight of the epoxy acrylic resin is 100-1000; The molecular weight of the first linear polymer and the second linear polymer are independently 100-1000, and the glass transition temperature is independently above 80°C; The first linear polymer and the second linear polymer are independently selected from one or more of a polyurethane polymer, an acrylic polymer, a silicone polymer and an epoxy polymer; And / or, the first linear polymer and the second linear polymer are independently aliphatic resins containing acrylate at the terminal group and hydroxyl groups on the molecular chain.

2. The photovoltaic barrier film with moisture and heat resistance according to claim 1, characterized in that: The curing agent is selected from one or more of water, amide curing agents, peroxide curing agents, organic acid curing agents and alkyl silicate curing agents.

3. The photovoltaic barrier film with moisture and heat resistance according to claim 1, characterized in that: The solvent is selected from alcohol solvents and / or ketone solvents; the diluent is ethyl acetate; the nano filler is selected from inorganic silicon oxides and / or inorganic silicates, and the particle size is 20 nm-200 nm.

4. The photovoltaic barrier film with moisture and heat resistance according to claim 1, characterized in that: The first auxiliary agent and the second auxiliary agent are independently selected from one or more of a leveling agent, an adhesion promoter and a light stabilizer.

5. The photovoltaic barrier film with moisture and heat resistance according to claim 1, characterized in that: The material of the characteristic barrier layer is a silicon-oxygen compound, wherein the molecular formula of the silicon-oxygen compound is Si a O b , b:a=1-2; the thickness of the characteristic barrier layer is 2 nm-300 nm.

6. The photovoltaic barrier film with moisture and heat resistance according to claim 1, characterized in that: The material of the substrate layer is selected from one or more of polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polypropylene, polyethylene, polyamide, polyimide, polycarbonate, polyvinyl chloride, polystyrene, polyacrylate, polyvinyl fluoride, polyvinylidene fluoride, triacetate and ethylene-tetrafluoroethylene copolymer; the thickness of the substrate layer is 2 μm-400 μm, the elongation at break is more than 200%, and the elongation at break is more than 40% when treated for 1000 h under 85°C and 85%Rh conditions.

7. A method for preparing a photovoltaic barrier film having moisture and heat resistance according to any one of claims 1 to 6, characterized in that: The preparation of the characteristic barrier layer comprises the following steps: preparing the characteristic barrier layer on the surface of the film layer by using vacuum coating technology; wherein the film layer is a layer structure arranged below the characteristic barrier layer; The preparation of the protective layer comprises the following steps: coating a protective layer slurry on the surface of the film layer and drying to form a protective layer; the protective layer slurry is obtained by adding a first linear polymer, a curing agent and a first auxiliary agent into a solvent and mixing them uniformly; wherein the film layer is a layer structure arranged below the protective layer; The preparation of the transition layer includes the following steps: coating a transition layer slurry on the surface of the film layer and forming the transition layer through electron beam curing; the transition layer slurry is obtained by adding a second linear polymer, epoxy acrylic resin, nanofiller and a second auxiliary agent into a diluent and mixing them evenly; wherein the film layer is a layer structure arranged below the transition layer.

8. The method for preparing a photovoltaic barrier film having moisture and heat resistance according to claim 7, characterized in that: The vacuum coating method is selected from vacuum evaporation coating and / or vacuum sputtering coating; the process parameters of the vacuum evaporation coating are: vacuum degree of 1 Pa-10 Pa, bombardment voltage of 0.2 kV-1 kV negative high voltage, and bombardment time of 5 min-10 min; the process parameters of the vacuum sputtering coating are: vacuum degree of 1 Pa-10 Pa, deposition rate of 0.1 μm / min-5 μm / min, and sputtering rate of 0.01 μm / min-0.5 μm / min.

9. The method for preparing a photovoltaic barrier film having moisture and heat resistance according to claim 7, characterized in that: The coating method is selected from one or more of micro-gap coating, slit coating and screen printing.

10. The method for preparing a photovoltaic barrier film having moisture and heat resistance according to claim 7, characterized in that: The irradiation current of the electron beam curing is 1.8 mA-2.2 mA, and the temperature is 20° C.-30° C.

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