Anti-ultraviolet solar cell backboard film and preparation method thereof

Abstract

The invention discloses an anti-ultraviolet solar cell backboard film and a preparation method thereof, and relates to the technical field of solar cell backboards, the anti-ultraviolet solar cell backboard film comprises a first anti-ultraviolet functional layer, a polyester base layer and a second anti-ultraviolet functional layer from top to bottom in sequence; the first uvioresistant functional layer and the second uvioresistant functional layer are independently prepared from the following raw materials: a functional polymer, 2-acrylamido-2-methylpropanesulfonic acid, 1, 3-bis (oxiranyl methyl)-5-(2-propenyl)-1, 3, 5-triazine-2, 4, 6 (1H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H, 3H The invention relates to a high-temperature-resistant nano-emulsion which is prepared from N-(4-cyano-3-trifluoromethylphenyl) methacrylamide, N-(4-cyano-3-trifluoromethylphenyl) methacrylamide, a nano-assistant, a coupling agent, an initiator, polyphosphoric acid and phosphorus pentoxide. The backboard film is good in ultraviolet aging resistance, good in interlayer peel strength and excellent in barrier property.

Description

Technical Field

[0001] The invention relates to the technical field of solar cell back panels, and in particular to an anti-ultraviolet solar cell back panel film and a preparation method thereof. Background Art

[0002] As the global demand for clean energy continues to grow, solar energy, as a sustainable and pollution-free energy source, has seen rapid development in its utilization technology. As the core component that converts solar energy into electrical energy, the performance and stability of solar cells directly affect the efficiency and life of solar power generation systems. In solar cell modules, solar cell backplane film, as an important packaging material, plays a key role in protecting the cell from external environmental erosion.

[0003] Solar cell backplane film is one of the packaging materials for solar cell modules. Its main function is to encapsulate crystalline silicon. In addition to having excellent electrical insulation, anti-oxidation, moisture resistance and long-term anti-hydrolysis performance of adhesives, it also needs to have high barrier properties. At present, since there is no single material in polymer materials that meets the requirements of solar backplane films, most of the backplane films in the prior art are multi-layer composite structures, with polyester film as the base film, coated with fluorine-containing materials such as polyvinyl fluoride film, polyvinylidene fluoride film or coated with fluorocarbon resin, etc. However, fluorine materials are expensive, the production process is complicated, the surface free energy is very low, the bonding performance with other materials is very poor, the interlayer peeling strength with the core layer material is poor, and it is easy to fall off. The prepared backplane has poor adhesion, low electrical insulation, and is easy to become brittle and tear. On the other hand, adhesives are used to bond the layers together, but the ester adhesive layer itself has large UV weather resistance and yellowing, and is easily hydrolyzed, and the performance decays seriously after aging. Other types of solar cell backplane films on the market also have more or less technical defects such as poor resistance to UV aging, interlayer peeling strength and water vapor barrier performance still need to be further improved.

[0004] In order to solve the above technical problems, the Chinese invention patent with the authorization publication number CN103681920B discloses a solar cell backplane and a manufacturing method thereof, including a middle substrate layer, wherein the upper and lower surfaces of the substrate layer are provided with a fluorine-containing film; the fluorine-containing film and the substrate layer are connected by an adhesive layer; wherein the substrate layer is composed of the following components in parts by weight: 80-90 parts of polyethylene terephthalate, 5-15 parts of anti-ultraviolet additives; the fluorine-containing film is composed of the following components in parts by weight: 70-80 parts of polyvinylidene fluoride, 5-10 parts of polymethyl methacrylate, 5-10 parts of titanium dioxide, and 1-2 parts of bismuth oxide. The solar cell backplane prepared by the invention method has a simple and reasonable structure and excellent barrier properties. However, due to compatibility issues, the anti-ultraviolet stability of the manufactured backplane is insufficient, and the anti-ultraviolet additive is prone to leakage during long-term use.

[0005] It can be seen that the development of an anti-ultraviolet solar cell backsheet film with good anti-ultraviolet aging performance, excellent interlayer peeling strength and outstanding barrier performance, as well as its preparation method, meets the market demand, has broad market value and application prospects, and is of great significance for promoting the development of the solar cell field. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide an anti-ultraviolet solar cell backsheet film with good anti-ultraviolet aging performance, excellent interlayer peeling strength and outstanding barrier performance, as well as its preparation method.

[0007] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0008] An anti-ultraviolet solar cell backsheet film, which sequentially includes an anti-ultraviolet first functional layer, a polyester base layer, and an anti-ultraviolet second functional layer from top to bottom; the anti-ultraviolet first functional layer and the anti-ultraviolet second functional layer are independently made of the following raw materials by weight: 70-80 parts of a functional polymer, 3-5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 3-5 parts of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1-3 parts of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 5-8 parts of a nano additive, 1-3 parts of a coupling agent, 0.8-1.2 parts of an initiator, 0.5-0.8 parts of polyphosphoric acid, 0.8-1.2 parts of phosphorus pentoxide; the functional polymer includes structural units introduced by the following monomers: N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine.

[0009] Preferably, the preparation method of the functional polymer includes the following steps: mixing N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, a catalyst, and a high-boiling solvent evenly, adding them into a high-pressure reaction kettle, purging the air in the reaction kettle with an inert gas, then stirring and reacting at 125-136 °C under normal pressure for 3-5 hours, then reducing the pressure to 30-150 Pa, raising the temperature to 250-270 °C, and carrying out a heat-preserving and pressure-preserving stirring reaction for 18-24 hours. After the reaction is completed, it is cooled to room temperature, precipitated in water, and the precipitated polymer is washed with ethanol 3-6 times, and finally dried to constant weight at 85-95 °C in a vacuum dryer to obtain the functional polymer.

[0010] Preferably, the molar ratio of N-(4H-1,2,4-triazol-4-yl) diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl] diethanolamine, catalyst, and high-boiling solvent is 0.8:0.2:1:(0.8 - 1.2):(6 - 10).

[0011] Preferably, the catalyst is a mixture formed by mixing antimony glycolate, tetrabutyl titanate, and p-toluenesulfonic acid in a mass ratio of (1 - 2):(0.8 - 1.2):0.5; the high-boiling solvent is dimethyl sulfoxide; the inert gas is any one of nitrogen, helium, neon, and argon.

[0012] Preferably, the nano-additive is at least one of nano-titanium dioxide, nano-boron nitride, and nano-zinc oxide.

[0013] Preferably, the particle size of the nano-additive is 10 - 90 nm.

[0014] Preferably, the coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570.

[0015] Preferably, the initiator is dicumyl peroxide.

[0016] Preferably, the polyester base layer is made from the following raw materials in parts by weight: 75 - 85 parts of PET resin, 0.3 - 0.5 parts of polyphosphoric acid, 0.5 - 0.8 parts of phosphorus pentoxide, 4 - 6 parts of benzidine disulfonic acid, and 1 - 3 parts of composite ultraviolet absorber.

[0017] Preferably, the PET resin is PET / PT7450 produced by DuPont Company of the United States.

[0018] Preferably, the composite ultraviolet absorber is a mixture of 2-hydroxy-4-methoxybenzophenone and 2-(2'-hydroxy-5'-tert-octylphenyl)-benzotriazole in a mass ratio of 1:(0.8 - 1.2).

[0019] Another object of the present invention is to provide a method for preparing the anti-ultraviolet solar cell backplane film, comprising the following steps:

[0020] Step S1: After mixing the raw materials of the polyester base layer evenly, a polyester base layer mixture is obtained. It is uniformly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 170 - 180 °C for 1 - 2 h to obtain the polyester base layer;

[0021] Step S2: After uniformly mixing the raw materials of the first anti-ultraviolet functional layer, a mixed material of the first anti-ultraviolet functional layer is obtained. It is uniformly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 170 - 180 °C for 1 - 2 h to obtain the first anti-ultraviolet functional layer; after uniformly mixing the raw materials of the second anti-ultraviolet functional layer, a mixed material of the second anti-ultraviolet functional layer is obtained. It is uniformly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 170 - 180 °C for 1 - 2 h to obtain the second anti-ultraviolet functional layer.

[0022] Step S3: Corona discharge is carried out 18 - 22 times on the polyester base layer, and they are sequentially laminated in the order of the first anti-ultraviolet functional layer, the polyester base layer, and the second anti-ultraviolet functional layer, and then hot-pressed into shape to obtain the anti-ultraviolet solar cell backplane film.

[0023] Preferably, the thickness of the polyester base layer is 150 - 300 μm; the thickness of the second anti-ultraviolet functional layer is 30 - 50 μm; the thickness of the first anti-ultraviolet functional layer is 30 - 50 μm.

[0024] Preferably, the temperature of the hot-pressing forming is 180 - 200 °C, and the pressure is 0.5 - 1 MPa.

[0025] The beneficial effects produced by adopting the above technical solutions are as follows:

[0026] (1) The preparation method of the anti-ultraviolet solar cell backplane film provided by the present invention has a simple process, convenient operation and control, is easy to implement, has low dependence on equipment, requires less equipment capital investment, has high preparation efficiency and high finished product qualification rate, is suitable for large-scale industrial production, and has high popularization and application value.

[0027] (2) The anti-ultraviolet solar cell backplane film provided by the present invention sequentially includes an anti-ultraviolet first functional layer, a polyester base layer, and an anti-ultraviolet second functional layer from top to bottom; through such a composite structure design, the advantages of each layer of materials can be effectively combined, endowing the product with more functions, so that the obtained backplane film has good anti-ultraviolet aging performance, excellent interlayer peel strength, and excellent barrier performance; the anti-ultraviolet first functional layer and the anti-ultraviolet second functional layer are independently made of the following raw materials by weight: 70-80 parts of a functional polymer, 3-5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 3-5 parts of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1-3 parts of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 5-8 parts of a nano additive, 1-3 parts of a coupling agent, 0.8-1.2 parts of an initiator, 0.5-0.8 parts of polyphosphoric acid, 0.8-1.2 parts of phosphorus pentoxide; the structural unit introduced by the following monomers is included in the functional polymer: N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine. The base materials of the anti-ultraviolet first functional layer, the anti-ultraviolet second functional layer and the base layer of the polyester base layer are all polyester, so that the compatibility between them is good, and defects such as delamination, poor structural stability, and short service life caused by surface activity problems are not likely to occur.The first anti-ultraviolet functional layer and the second anti-ultraviolet functional layer are based on a functional polymer, and the functional polymer includes structural units introduced by the following monomers: N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine; the structures of triazole, quinoline, benzotriazole and polyester are simultaneously introduced into the molecular structure. Under the multiple effects of electronic effect, steric effect and conjugation effect, etc., the made backplane film has better anti-ultraviolet aging performance, better mechanical and mechanical properties, and more excellent barrier properties; raw material components containing unsaturated double bonds such as 2-acrylamido-2-methylpropanesulfonic acid, 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, N-(4-cyano-3-trifluoromethylphenyl)methacrylamide will undergo copolymerization reaction under the action of an initiator, and the structures of triazinone, fluorobenzene, cyano and amide group are simultaneously introduced into the molecular structure of the anti-ultraviolet functional layer, and cooperate with other structures to further improve the anti-ultraviolet performance, mechanical and mechanical properties and barrier properties; the epoxy groups on 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione can react with the amino groups in the polyester base layer to undergo epoxy ring-opening reaction, so that the layers are connected in the form of covalent bonds, further improving the interlayer peel strength, making the structural stability better, and effectively extending the service life of the backplane film.

[0028] (3) For the anti-ultraviolet solar cell backplane film provided by the present invention, the structures of each layer form an interpenetrating network structure, which can effectively improve the anti-ultraviolet performance, interlayer peel strength and barrier properties of the backplane film, and thus effectively extend its service life. The addition of nano additives can not only improve the interlayer peel strength, but also effectively improve the anti-ultraviolet performance.

[0029] (4) For the anti-ultraviolet solar cell backplane film provided by the present invention, through the reasonable selection of preparation steps and process parameters, the made material is easy to process and form, has good anti-ultraviolet aging performance, good interlayer peel strength, excellent barrier properties and long service life. Detailed implementation manners

[0030] In order to enable those skilled in the art to better understand the technical solution of the present invention and make the above features, purposes and advantages of the present invention clearer and easier to understand, the present invention will be further described below with reference to embodiments. The embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0031] Example 1

[0032] An anti-ultraviolet solar cell backplane film, which successively includes an anti-ultraviolet first functional layer, a polyester base layer, and an anti-ultraviolet second functional layer from top to bottom; the anti-ultraviolet first functional layer and the anti-ultraviolet second functional layer are independently made of the following raw materials by weight: 70 parts of functional polymer, 3 parts of 2-acrylamido-2-methylpropanesulfonic acid, 3 parts of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1 part of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 5 parts of nano additive, 1 part of coupling agent, 0.8 part of initiator, 0.5 part of polyphosphoric acid, 0.8 part of phosphorus pentoxide; the functional polymer includes structural units introduced by the following monomers: N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine.

[0033] The preparation method of the functional polymer includes the following steps: Mix N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, catalyst, and high-boiling solvent evenly, then add them into a high-pressure reaction kettle, displace the air in the reaction kettle with inert gas, then stir and react at 125 °C under normal pressure for 3 hours, then reduce the pressure to 30 Pa, raise the temperature to 250 °C, keep the temperature and pressure constant and stir and react for 18 hours. After the reaction is over, cool to room temperature, precipitate in water, then wash the precipitated polymer with ethanol 3 times, and finally dry it at 85 °C in a vacuum dryer until constant weight to obtain the functional polymer; the molar ratio of N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, catalyst, and high-boiling solvent is 0.8:0.2:1:0.8:6; the catalyst is a mixture formed by mixing antimony glycolate, tetrabutyl titanate, and p-toluenesulfonic acid according to a mass ratio of 1:0.8:0.5; the high-boiling solvent is dimethyl sulfoxide; the inert gas is nitrogen. Through GPC test, the number-average molecular weight of this functional polymer is 15170 g / mol, M W / M n = 1.293; through elemental analysis and weight change calculation, the molar ratio of the structural units introduced by N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, and N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine is the same as the theoretical value.

[0034] The nano additive is nano titanium dioxide; the particle size of the nano additive is 10 nm; the coupling agent is silane coupling agent KH550; the initiator is dicumyl peroxide; the polyester base layer is made of the following raw materials by weight: 75 parts of PET resin, 0.3 part of polyphosphoric acid, 0.5 part of phosphorus pentoxide, 4 parts of benzidine disulfonic acid, and 1 part of composite ultraviolet absorber; the PET resin is PET / PT7450 produced by DuPont Company of the United States; the composite ultraviolet absorber is a mixture of 2-hydroxy-4-methoxybenzophenone and 2-(2'-hydroxy-5'-tert-octylphenyl)-benzotriazole in a mass ratio of 1:0.8.

[0035] A preparation method of the anti-ultraviolet solar cell backplane film comprises the following steps:

[0036] Step S1: After mixing the raw materials of the polyester base layer evenly, a polyester base layer mixture is obtained. It is evenly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 170 °C for 1 h to obtain the polyester base layer.

[0037] Step S2: After mixing the raw materials of the first anti-ultraviolet functional layer evenly, a first anti-ultraviolet functional layer mixture is obtained. It is evenly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 170 °C for 1 h to obtain the first anti-ultraviolet functional layer; after mixing the raw materials of the second anti-ultraviolet functional layer evenly, a second anti-ultraviolet functional layer mixture is obtained. It is evenly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 170 °C for 1 h to obtain the second anti-ultraviolet functional layer.

[0038] Step S3: Corona discharge is carried out 18 times on the polyester base layer, and they are sequentially laminated in the order of the first anti-ultraviolet functional layer, the polyester base layer, and the second anti-ultraviolet functional layer, and hot-pressed into shape to obtain the anti-ultraviolet solar cell backplane film.

[0039] The thickness of the polyester base layer is 150 μm; the thickness of the second anti-ultraviolet functional layer is 30 μm; the thickness of the first anti-ultraviolet functional layer is 30 μm; the temperature of the hot-pressing into shape is 180 °C, and the pressure is 0.5 MPa.

[0040] Example 2

[0041] An anti-ultraviolet solar cell backplane film, which sequentially includes an anti-ultraviolet first functional layer, a polyester base layer, and an anti-ultraviolet second functional layer from top to bottom; the anti-ultraviolet first functional layer and the anti-ultraviolet second functional layer are independently made of the following raw materials by weight: 73 parts of a functional polymer, 3.5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 3.5 parts of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1.5 parts of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 6 parts of a nano additive, 1.5 parts of a coupling agent, 0.9 part of an initiator, 0.6 part of polyphosphoric acid, and 0.9 part of phosphorus pentoxide; the functional polymer includes structural units introduced by the following monomers: N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, and N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine.

[0042] The preparation method of the functional polymer includes the following steps: Mix N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, a catalyst, and a high-boiling solvent evenly, then add them into a high-pressure reaction kettle, displace the air in the reaction kettle with an inert gas, then stir and react at 125-136°C under normal pressure for 3.5 hours, then reduce the pressure to 50 Pa, raise the temperature to 255°C, keep the temperature and pressure constant and stir and react for 20 hours. After the reaction is completed, cool to room temperature, precipitate in water, then wash the precipitated polymer with ethanol 4 times, and finally dry it to constant weight at 87°C in a vacuum dryer to obtain the functional polymer; the molar ratio of N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, the catalyst, and the high-boiling solvent is 0.8:0.2:1:0.9:7; the catalyst is a mixture formed by mixing antimony glycolate, tetrabutyl titanate, and p-toluenesulfonic acid according to a mass ratio of 1.3:0.9:0.5; the high-boiling solvent is dimethyl sulfoxide; the inert gas is helium.

[0043] The nano additive is nano boron nitride; the particle size of the nano additive is 30 nm; the coupling agent is silane coupling agent KH560; the initiator is dicumyl peroxide; the polyester base layer is made from the following raw materials in parts by weight: 78 parts of PET resin, 0.35 part of polyphosphoric acid, 0.6 part of phosphorus pentoxide, 4.5 parts of benzidine disulfonic acid, and 1.5 parts of composite ultraviolet absorber; the PET resin is PET / PT7450 produced by DuPont Company of the United States; the composite ultraviolet absorber is composed of 2-hydroxy-4-methoxybenzophenone and 2-(2'-hydroxy-5'-tert-octylphenyl)-benzotriazole mixed in a mass ratio of 1:0.9.

[0044] A preparation method of the anti-ultraviolet solar cell backplane film comprises the following steps:

[0045] Step S1: After mixing the raw materials of the polyester base layer evenly, a polyester base layer mixed material is obtained. It is evenly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 173 °C for 1.2 h to obtain the polyester base layer.

[0046] Step S2: After mixing the raw materials of the first anti-ultraviolet functional layer evenly, a first anti-ultraviolet functional layer mixed material is obtained. It is evenly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 173 °C for 1.2 h to obtain the first anti-ultraviolet functional layer; after mixing the raw materials of the second anti-ultraviolet functional layer evenly, a second anti-ultraviolet functional layer mixed material is obtained. It is evenly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 173 °C for 1.2 h to obtain the second anti-ultraviolet functional layer.

[0047] Step S3: Corona discharge is carried out on the polyester base layer for 18 - 22 times, and they are sequentially laminated in the order of the first anti-ultraviolet functional layer, the polyester base layer, and the second anti-ultraviolet functional layer, and hot-pressed into shape to obtain the anti-ultraviolet solar cell backplane film.

[0048] The thickness of the polyester base layer is 150 μm; the thickness of the second anti-ultraviolet functional layer is 30 μm; the thickness of the first anti-ultraviolet functional layer is 30 μm; the temperature of the hot-pressing into shape is 185 °C, and the pressure is 0.7 MPa.

[0049] Example 3

[0050] An anti-ultraviolet solar cell backplane film, which sequentially includes an anti-ultraviolet first functional layer, a polyester base layer, and an anti-ultraviolet second functional layer from top to bottom; the anti-ultraviolet first functional layer and the anti-ultraviolet second functional layer are independently made of the following raw materials by weight: 75 parts of functional polymer, 4 parts of 2-acrylamido-2-methylpropanesulfonic acid, 4 parts of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2 parts of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 6.5 parts of nano additive, 2 parts of coupling agent, 1 part of initiator, 0.65 part of polyphosphoric acid, 1 part of phosphorus pentoxide; the functional polymer includes structural units introduced by the following monomers: N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine.

[0051] The preparation method of the functional polymer includes the following steps: Mix N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, a catalyst, and a high-boiling solvent evenly, then add them into a high-pressure reaction kettle, displace the air in the reaction kettle with an inert gas, then stir and react at 131 °C under normal pressure for 4 hours, then reduce the pressure to 110 Pa, raise the temperature to 260 °C, keep the temperature and pressure constant and stir and react for 21 hours. After the reaction is completed, cool to room temperature, precipitate in water, then wash the precipitated polymer with ethanol 5 times, and finally place it in a vacuum dryer and dry it at 90 °C to constant weight to obtain the functional polymer; the molar ratio of N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, the catalyst, and the high-boiling solvent is 0.8:0.2:1:1:8; the catalyst is a mixture formed by mixing antimony glycolate, tetrabutyl titanate, and p-toluenesulfonic acid according to a mass ratio of 1.5:1:0.5; the high-boiling solvent is dimethyl sulfoxide; the inert gas is neon.

[0052] The nano additive is nano zinc oxide; the particle size of the nano additive is 60 nm; the coupling agent is silane coupling agent KH570; the initiator is diisopropyl peroxide; the polyester base layer is made of the following raw materials by weight: 80 parts of PET resin, 0.4 part of polyphosphoric acid, 0.65 part of phosphorus pentoxide, 5 parts of benzidine disulfonic acid, 2 parts of composite ultraviolet absorber; the PET resin is PET / PT7450 produced by DuPont Company of the United States; the composite ultraviolet absorber is a mixture formed by mixing 2-hydroxy-4-methoxybenzophenone and 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole according to a mass ratio of 1:1.

[0053] A preparation method of the ultraviolet-resistant solar cell backsheet film comprises the following steps:

[0054] Step S1: After uniformly mixing the raw materials of the polyester base layer, a polyester base layer mixed material is obtained. It is uniformly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 175 °C for 1.5 h to obtain the polyester base layer;

[0055] Step S2: After uniformly mixing the raw materials of the first ultraviolet-resistant functional layer, a first ultraviolet-resistant functional layer mixed material is obtained. It is uniformly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 175 °C for 1.5 h to obtain the first ultraviolet-resistant functional layer; After uniformly mixing the raw materials of the second ultraviolet-resistant functional layer, a second ultraviolet-resistant functional layer mixed material is obtained. It is uniformly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 175 °C for 1.5 h to obtain the second ultraviolet-resistant functional layer;

[0056] Step S3: Corona discharge is carried out 20 times on the polyester base layer, and they are sequentially laminated in the order of the first ultraviolet-resistant functional layer, the polyester base layer, and the second ultraviolet-resistant functional layer, and hot-pressed into shape to obtain the ultraviolet-resistant solar cell backsheet film.

[0057] The thickness of the polyester base layer is 150 μm; the thickness of the second ultraviolet-resistant functional layer is 30 μm; the thickness of the first ultraviolet-resistant functional layer is 30 μm; the temperature of the hot-pressing into shape is 190 °C, and the pressure is 0.8 MPa.

[0058] Example 4

[0059] An ultraviolet-resistant solar cell backsheet film sequentially comprises a first ultraviolet-resistant functional layer, a polyester base layer, and a second ultraviolet-resistant functional layer from top to bottom; the first ultraviolet-resistant functional layer and the second ultraviolet-resistant functional layer are independently made of the following raw materials by weight: 78 parts of a functional polymer, 4.5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 4.5 parts of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2.5 parts of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 7.5 parts of a nano additive, 2.5 parts of a coupling agent, 1.1 parts of an initiator, 0.75 part of polyphosphoric acid, and 1.1 parts of phosphorus pentoxide; the functional polymer comprises structural units introduced by the following monomers: N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, and N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine.

[0060] The preparation method of the functional polymer comprises the following steps: Mix N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, a catalyst, and a high-boiling solvent uniformly, then add them into a high-pressure reaction kettle. Replace the air in the reaction kettle with an inert gas. Then, stir and react at 133 °C under normal pressure for 4.5 hours. Next, reduce the pressure to 140 Pa, raise the temperature to 265 °C, and stir and react under constant temperature and pressure for 23 hours. After the reaction is completed, cool it to room temperature, precipitate it in water, wash the precipitated polymer with ethanol 5 times, and finally dry it in a vacuum dryer at 93 °C until constant weight to obtain the functional polymer; the molar ratio of N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, the catalyst, and the high-boiling solvent is 0.8:0.2:1:1.1:9.5; the catalyst is a mixture formed by mixing antimony glycolate, tetrabutyl titanate, and p-toluenesulfonic acid according to a mass ratio of 1.8:1.1:0.5; the high-boiling solvent is dimethyl sulfoxide; the inert gas is argon.

[0061] The nano-additive is formed by mixing nano-titanium dioxide, nano-boron nitride, and nano-zinc oxide according to a mass ratio of 1:2:3; the particle size of the nano-additive is 80 nm; the coupling agent is formed by mixing silane coupling agent KH550, silane coupling agent KH560, and silane coupling agent KH570 according to a mass ratio of 1:2:3; the initiator is diisopropylbenzene peroxide; the polyester base layer is made of the following raw materials by weight: 83 parts of PET resin, 0.45 part of polyphosphoric acid, 0.75 part of phosphorus pentoxide, 5.5 parts of benzidine disulfonic acid, and 2.5 parts of a composite ultraviolet absorber; the PET resin is PET / PT7450 produced by DuPont Company of the United States; the composite ultraviolet absorber is formed by mixing 2-hydroxy-4-methoxybenzophenone and 2-(2'-hydroxy-5'-tert-octylphenyl)-benzotriazole according to a mass ratio of 1:1.1.

[0062] A preparation method of the anti-ultraviolet solar cell backplane film comprises the following steps:

[0063] Step S1: Mix the raw materials of the polyester base layer uniformly to obtain a polyester base layer mixture, disperse it uniformly in N,N-dimethylformamide, cast it into a film, and then heat-treat it at 178 °C for 1.8 h to obtain the polyester base layer;

[0064] Step S2: After uniformly mixing the raw materials of the first anti-ultraviolet functional layer, a mixed material of the first anti-ultraviolet functional layer is obtained. It is uniformly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 178 °C for 1.8 h to obtain the first anti-ultraviolet functional layer; after uniformly mixing the raw materials of the second anti-ultraviolet functional layer, a mixed material of the second anti-ultraviolet functional layer is obtained. It is uniformly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 178 °C for 1.8 h to obtain the second anti-ultraviolet functional layer;

[0065] Step S3: Corona discharge is carried out 21 times on the polyester base layer, and they are sequentially laminated in the order of the first anti-ultraviolet functional layer, the polyester base layer, and the second anti-ultraviolet functional layer, and then hot-pressed into shape to obtain the anti-ultraviolet solar cell backplane film.

[0066] The thickness of the polyester base layer is 150 μm; the thickness of the second anti-ultraviolet functional layer is 30 μm; the thickness of the first anti-ultraviolet functional layer is 30 μm; the temperature of the hot-pressing into shape is 195 °C, and the pressure is 0.9 MPa.

[0067] Example 5

[0068] An anti-ultraviolet solar cell backplane film includes, from top to bottom in sequence, a first anti-ultraviolet functional layer, a polyester base layer, and a second anti-ultraviolet functional layer; the first anti-ultraviolet functional layer and the second anti-ultraviolet functional layer are independently made of the following raw materials by weight: 80 parts of functional polymer, 5 parts of 2-acrylamido-2-methylpropanesulfonic acid, 5 parts of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 3 parts of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 8 parts of nano additive, 3 parts of coupling agent, 1.2 parts of initiator, 0.8 part of polyphosphoric acid, 1.2 parts of phosphorus pentoxide; the functional polymer includes structural units introduced by the following monomers: N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine.

[0069] The preparation method of the functional polymer comprises the following steps: Mix N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, a catalyst, and a high-boiling solvent uniformly, then add them into a high-pressure reaction kettle. Replace the air in the reaction kettle with an inert gas. Then, stir and react at 136 °C under normal pressure for 5 hours. Next, reduce the pressure to 150 Pa and raise the temperature to 270 °C, and keep the temperature and pressure constant and stir and react for 24 hours. After the reaction is completed, cool it to room temperature, precipitate it in water, and then wash the precipitated polymer with ethanol 6 times. Finally, place it in a vacuum dryer and dry it at 95 °C until constant weight to obtain the functional polymer; the molar ratio of N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, the catalyst, and the high-boiling solvent is 0.8:0.2:1:1.2:10; the catalyst is a mixture formed by mixing antimony glycolate, tetrabutyl titanate, and p-toluenesulfonic acid according to a mass ratio of 2:1.2:0.5; the high-boiling solvent is dimethyl sulfoxide; the inert gas is nitrogen.

[0070] The nano additive is nano titanium dioxide; the particle size of the nano additive is 90 nm; the coupling agent is silane coupling agent KH550; the initiator is diisopropyl peroxide; the polyester base layer is made of the following raw materials in parts by weight: 85 parts of PET resin, 0.5 part of polyphosphoric acid, 0.8 part of phosphorus pentoxide, 6 parts of benzidine disulfonic acid, and 3 parts of a composite ultraviolet absorber; the PET resin is PET / PT7450 produced by DuPont Company of the United States; the composite ultraviolet absorber is a mixture formed by mixing 2-hydroxy-4-methoxybenzophenone and 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole according to a mass ratio of 1:1.2.

[0071] A preparation method of the anti-ultraviolet solar cell backplane film comprises the following steps:

[0072] Step S1: Mix the raw materials of the polyester base layer uniformly to obtain a polyester base layer mixed material, disperse it uniformly in N,N-dimethylformamide, cast it into a film, and then heat-treat it at 180 °C for 2 h to obtain the polyester base layer;

[0073] Step S2: After uniformly mixing the raw materials of the first anti-ultraviolet functional layer, a mixed material of the first anti-ultraviolet functional layer is obtained. It is uniformly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 180°C for 2 h to obtain the first anti-ultraviolet functional layer; after uniformly mixing the raw materials of the second anti-ultraviolet functional layer, a mixed material of the second anti-ultraviolet functional layer is obtained. It is uniformly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 180°C for 2 h to obtain the second anti-ultraviolet functional layer;

[0074] Step S3: Corona discharge is carried out 22 times on the polyester base layer, and they are sequentially laminated in the order of the first anti-ultraviolet functional layer, the polyester base layer, and the second anti-ultraviolet functional layer, and then hot-pressed into shape to obtain the anti-ultraviolet solar cell backplane film.

[0075] The thickness of the polyester base layer is 150 μm; the thickness of the second anti-ultraviolet functional layer is 30 μm; the thickness of the first anti-ultraviolet functional layer is 30 μm; the temperature of the hot-pressing into shape is 200°C, and the pressure is 1 MPa.

[0076] Comparative Example 1

[0077] An anti-ultraviolet solar cell backplane film is basically the same as that of Example 1, except that 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione is not added, and N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid is used to replace 2,3-quinoxalinedicarboxylic acid in an equal amount.

[0078] Comparative Example 2

[0079] An anti-ultraviolet solar cell backplane film is basically the same as that of Example 1, except that 2-acrylamido-2-methylpropanesulfonic acid is not added, and 2,3-quinoxalinedicarboxylic acid is used to replace N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid in an equal amount.

[0080] The anti-ultraviolet solar cell backplane films prepared in Examples 1-5 and Comparative Examples 1-2 are respectively subjected to relevant performance tests. The test results are shown in Table 1. The test method refers to GB / T31034-2014 "Insulating Backplane for Crystalline Silicon Solar Cell Modules". Among them, the electrolytic sensor method (38°C, 90% RH) is used for the test of water vapor transmission rate.

[0081] Table 1 Performance Test Results of Anti-ultraviolet Solar Cell Backplane Films

[0082]

[0083] As can be seen from Table 1, the anti-ultraviolet solar cell backplane films disclosed in the embodiments of the present invention have better barrier properties and anti-ultraviolet properties, and greater interlayer peel strength. The combined use of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2-acrylamido-2-methylpropanesulfonic acid, N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid and 2,3-quinoxalinedicarboxylic acid is beneficial to improving the above properties.

[0084] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the principles described in the specification are only the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed. The scope of protection required by the present invention is defined by the appended claims and their equivalents.

Claims

1. An anti-ultraviolet solar cell backplane film, characterized in that: From top to bottom, it includes an anti-ultraviolet first functional layer, a polyester base layer, and an anti-ultraviolet second functional layer; the anti-ultraviolet first functional layer and the anti-ultraviolet second functional layer are independently made of the following raw materials in parts by weight: 70-80 parts of functional polymer, 3-5 parts of 2-acrylamide-2-methylpropanesulfonic acid, 3-5 parts of 1,3-bis(oxiranylmethyl)-5-(2-propenyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1-3 parts of N-(4-cyano-3-trifluoromethylphenyl)methacrylamide, 5-8 parts of nano-auxiliary agent, 1-3 parts of coupling agent, 0.8-1.2 parts of initiator, 0.5-0.8 parts of polyphosphoric acid, and 0.8-1.2 parts of phosphorus pentoxide; the functional polymer includes structural units introduced by the following monomers: N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine.

2. The anti-ultraviolet solar cell back sheet film according to claim 1, characterized in that: The preparation method of the functional polymer comprises the following steps: uniformly mixing N-(4H-1,2,4-triazole-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazole-1-yl)methyl]diethanolamine, a catalyst and a high boiling point solvent, adding the mixture into a high pressure reactor, replacing the air in the reactor with an inert gas, stirring and reacting for 3-5 hours at 125-136°C under normal pressure, reducing the pressure to 30-150 Pa, heating to 250-270°C, stirring and reacting for 18-24 hours while maintaining the temperature and pressure, cooling to room temperature after the reaction is completed, precipitating the polymer in water, washing the precipitated polymer with ethanol for 3-6 times, and finally drying the polymer in a vacuum dryer at 85-95°C to a constant weight to obtain the functional polymer.

3. The anti-ultraviolet solar cell back sheet film according to claim 2, characterized in that: The molar ratio of the N-(4H-1,2,4-triazol-4-yl)diphenylamine-4,4'-dicarboxylic acid, 2,3-quinolinedicarboxylic acid, N-[(4-methyl-1H-benzotriazol-1-yl)methyl]diethanolamine, catalyst and high boiling point solvent is 0.8:0.2:1:(0.8-1.2):(6-10).

4. The anti-ultraviolet solar cell back sheet film according to claim 2, characterized in that: The catalyst is a mixture of antimony ethylene glycol, tetrabutyl titanate and p-toluenesulfonic acid in a mass ratio of (1-2):(0.8-1.2):0.5; the high boiling point solvent is dimethyl sulfoxide; and the inert gas is any one of nitrogen, helium, neon and argon.

5. The anti-ultraviolet solar cell back sheet film according to claim 1, characterized in that: The nano auxiliary agent is at least one of nano titanium dioxide, nano boron nitride and nano zinc oxide; the particle size of the nano auxiliary agent is 10-90nm.

6. The anti-ultraviolet solar cell back sheet film according to claim 1, characterized in that: The coupling agent is at least one of silane coupling agent KH550, silane coupling agent KH560 and silane coupling agent KH570; and the initiator is dicumyl peroxide.

7. The anti-ultraviolet solar cell back sheet film according to claim 1, characterized in that: The polyester base layer is made of the following raw materials in parts by weight: 75-85 parts of PET resin, 0.3-0.5 parts of polyphosphoric acid, 0.5-0.8 parts of phosphorus pentoxide, 4-6 parts of benzidine disulfonic acid, and 1-3 parts of a composite ultraviolet absorber; the PET resin is PET / PT7450 produced by DuPont of the United States; the composite ultraviolet absorber is a mixture of 2-hydroxy-4-methoxybenzophenone and 2-(2'-hydroxy-5'-tert-octylphenyl)-benzotriazole in a mass ratio of 1:(0.8-1.2).

8. A method for preparing the anti-ultraviolet solar cell backplane film according to any one of claims 1 to 7, characterized in that: The steps include: Step S1, after uniformly mixing the raw materials of the polyester base layer to obtain a polyester base layer mixed material, the polyester base layer mixed material is uniformly dispersed in N,N-dimethylformamide, cast into a film, and then heat-treated at 170-180° C. for 1-2 hours to obtain a polyester base layer; Step S2, after uniformly mixing the raw materials of the first anti-ultraviolet functional layer, obtaining a mixed material of the first anti-ultraviolet functional layer, uniformly dispersing the mixed material in N,N-dimethylformamide, casting into a film, and heat-treating the mixed material at 170-180° C. for 1-2 hours to obtain the first anti-ultraviolet functional layer; after uniformly mixing the raw materials of the second anti-ultraviolet functional layer, obtaining a mixed material of the second anti-ultraviolet functional layer, uniformly dispersing the mixed material in N,N-dimethylformamide, casting into a film, and heat-treating the mixed material at 170-180° C. for 1-2 hours to obtain the second anti-ultraviolet functional layer; Step S3, performing corona discharge on the polyester base layer for 18-22 times, and stacking the first anti-ultraviolet functional layer, the polyester base layer, and the second anti-ultraviolet functional layer in this order, and hot pressing and molding to obtain an anti-ultraviolet solar cell backplane film.

9. The method for preparing the anti-ultraviolet solar cell backplane film according to claim 8, characterized in that: The thickness of the polyester base layer is 150-300 μm; the thickness of the second anti-ultraviolet functional layer is 30-50 μm; and the thickness of the first anti-ultraviolet functional layer is 30-50 μm.

10. The method for preparing the anti-ultraviolet solar cell backplane film according to claim 8, characterized in that: The temperature of the hot pressing molding is 180-200° C. and the pressure is 0.5-1 MPa.

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