Photovoltaic super-hydrophobic self-repairing polyurethane film and preparation method thereof

Abstract

The invention discloses a super-hydrophobic self-repairing polyurethane film for photovoltaics and a preparation method of the super-hydrophobic self-repairing polyurethane film. The super-hydrophobic self-repairing polyurethane film is prepared from the following components in parts by weight: polyether polyol, isocyanate, a catalyst, a solvent, a self-repairing auxiliary agent, a chain extender and super-hydrophobic nanoparticles, the super-hydrophobic nano particles are fluorine-silicon polymer nano particles which are modified hydrophobic nano particles obtained by hydrolyzing two or more organic silicon and then introducing a C-F bond through copolycondensation to realize fluorination modification; the service life of the composite material is prolonged, the durability of the composite material is improved, and the material can be self-healed after being damaged by the outside; on the basis of self-repairing, hydrophobic nanoparticles are added to realize a super-hydrophobic surface; the transparent polyurethane film material for the photovoltaic power generation panel can be adhered through electrostatic adsorption or other adhesives, so that the film material is loaded on the photovoltaic panel, the photovoltaic panel is protected, and the photovoltaic panel is prevented from being damaged due to external environment pollution.

Description

Technical Field

[0001] The present invention relates to the technical field of polyurethane film preparation, and in particular to a super-hydrophobic self-repairing polyurethane film for photovoltaics and a preparation method thereof. Background Art

[0002] With the promotion of environmental protection concepts, more and more groups have paid attention to renewable energy, such as hydropower, wind power, solar energy, biomass (biogas), geothermal energy (including ground source and water source), tidal energy, etc. Among them, solar power generation refers to a method in which photovoltaic modules convert light energy into electrical energy under the irradiation of sunlight. Photovoltaic power stations are an important part of it. Dust, rain, bird droppings and other dirt will seriously affect the power generation efficiency of photovoltaic panels. Most photovoltaic panels are located at sea or in deserts and fields. The coating must be completed before the photovoltaic panels leave the factory. For photovoltaic panels that have been installed at the factory, on-site operations are difficult, and effective coating cannot be guaranteed, and a lot of manpower and material resources are required. If the coating on the photovoltaic panel is attenuated and needs to be re-coated, the original coating must be cleaned with a solvent first. After cleaning, it needs to be coated quickly to prevent dust and stains from adhering again and affecting the film-forming performance. The outdoor coating of the coating needs to consider the influence of temperature, humidity and weather factors. If it is exposed to rain too early after coating, the coating will fail or the effect will be weakened.

[0003] Most solutions nowadays are to apply a layer of hydrophobic or hydrophilic coating on the surface of photovoltaic panels, which can effectively solve the self-cleaning problem of photovoltaic panels without affecting the transmittance. This method is more suitable for direct coating in factories. It is difficult to apply coating to photovoltaic panels that have been installed at the factory, and it is difficult to perform maintenance and rework in the later stage.

[0004] Self-healing polyurethane is a polymer material that can gradually recover to its pre-damage state after being damaged by external factors. Its stability and plasticity have made it the matrix of choice for many materials.

[0005] Therefore, in order to solve the above problems, the present invention discloses a super hydrophobic self-healing polyurethane film for photovoltaics and a preparation method thereof, wherein disulfide compounds are introduced into a polyurethane matrix, and its self-healing mechanism is mainly through internal disulfide bonds, which can be re-entangled and reconnected after being cut to achieve self-healing. Summary of the invention

[0006] The purpose of the present invention is to provide a super-hydrophobic self-healing polyurethane film for photovoltaics and a preparation method thereof, so as to fill the gap in the current technology.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A super-hydrophobic self-healing polyurethane film for photovoltaics comprises the following components by weight: 10 to 35 parts of polyether polyol, 3 to 15 parts of isocyanate, 0.04 to 1 part of catalyst, 10 to 20 parts of solvent, 2 to 6 parts of self-healing auxiliary agent, 0.5 to 5 parts of chain extender and 0.1 to 10 parts of super-hydrophobic nanoparticles.

[0009] Preferably, the super-hydrophobic nanoparticles are fluorosilicone polymer nanoparticles, which are modified hydrophobic nanoparticles obtained by hydrolyzing two or more organic silicons and then introducing CF bonds through co-condensation to achieve fluorination modification.

[0010] Preferably, the molecular weight of the polyether polyol is 1000-2000, and the polyether polyol is selected from one or more of polytetramethylene glycol (PTMEG), polypropylene glycol (PPG), and tetramethylene glycol-propylene oxide copolymer.

[0011] Preferably, the isocyanate is selected from one or more of isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), and diphenylmethane diisocyanate (MDI).

[0012] Preferably, the catalyst is selected from one or more of dibutyltin dilaurate (DBTDL), N,N-dimethylcyclohexylamine, bis(2-dimethylaminoethyl) ether, triethylamine, N,N-dimethylbenzylamine, N-ethylmorpholine, N-methylmorpholine, triethanolamine, and N,N-lutidine.

[0013] Preferably, the solvent is selected from one or more of N,N-dimethylformamide (DMF), N-methylpyrrolidone (NMP) and dichloromethane (DCM).

[0014] Preferably, the chain extender is selected from one or more of 1,4-butanediol, ethylene glycol, diethanolamine, and hydroquinone dihydroxyethyl ether (HQEE).

[0015] Preferably, the self-repairing agent is a disulfide bond-containing self-repairing agent, and the self-repairing agent is selected from one or more of 4,4'-dithiodiphenylamine, bis(2-hydroxyethyl) disulfide, and 2,2-dithiodiphenylamine.

[0016] A method for preparing a super-hydrophobic self-repairing polyurethane film for photovoltaics comprises the following steps:

[0017] S1. Dehydrate the polyether polyol in a vacuum drying oven at 100-120°C for 2-3 hours, take it out, seal it and cool it to room temperature for use;

[0018] S2, mixing the dehydrated polyether polyol and isocyanate uniformly, adding a catalyst under the protection of a nitrogen atmosphere, and performing a polymerization reaction at 75-80° C. and 300-350 r / min for 2-4 hours to obtain a uniformly mixed polyurethane prepolymer;

[0019] S3, adding a self-repairing agent and a solvent to the uniformly mixed polyurethane prepolymer obtained in step S2, and continuing the reaction at 75 to 80° C. for 5 to 7 hours to obtain a polyurethane solution with self-repairing properties;

[0020] S4, raising the temperature of the polyurethane solution with self-repairing properties obtained in step S3 to 80-85° C., adding a chain extender to carry out a chain extension reaction, and reacting for 30-35 minutes to obtain a self-repairing polyurethane film material with a high degree of polymerization;

[0021] S5. After mixing the self-healing polyurethane film material with a high degree of polymerization obtained in step S4 with the super-hydrophobic nanoparticles, vacuum-drying the mixture in an oven at 60 to 70° C. for 12 to 16 hours, and then raising the temperature to 100 to 110° C. and vacuum-drying the mixture for 12 to 16 hours to obtain the super-hydrophobic self-healing polyurethane film for photovoltaics.

[0022] Working mechanism of the present invention:

[0023] The present invention introduces a self-repairing auxiliary agent to make the composite film have self-repairing performance, improves the service life and durability of the composite material, and can self-heal after the material is damaged by the outside world; on the basis of self-repairing, hydrophobic nanoparticles are added to realize a super-hydrophobic surface. The present invention mixes the hydrophobic nanoparticles with the self-repairing polyurethane by physical blending, and can make the composite material have super-hydrophobicity without affecting the self-repairing performance. The transparent polyurethane film material used for photovoltaic panels of the present invention can be adhered by electrostatic adsorption or other adhesives, so that the film material is loaded on the photovoltaic panel, which plays a protective role for the photovoltaic panel and prevents the photovoltaic panel from being damaged by external environmental pollution.

[0024] Due to the application of the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0025] 1. The super-hydrophobic self-healing polyurethane film for photovoltaics prepared by the present invention can achieve self-cleaning after the photovoltaic panel is contaminated by dust, rain and fog droplets by utilizing its super-hydrophobic surface;

[0026] 2. The super-hydrophobic self-healing polyurethane film for photovoltaics prepared by the present invention can quickly self-heal after being damaged, restore the original morphology and performance, have high self-healing efficiency, and have a simple production process and stable performance, and are suitable for industrial production;

[0027] 3. The super-hydrophobic self-healing polyurethane film for photovoltaics prepared by the present invention combines a transparent polyurethane film with a self-healing function with super-phobic particles to form a transparent super-phobic polyurethane film, the hydrophobic angle of which is greater than 150°, the rolling angle is less than 5°, and the transmittance is greater than 92% within the wavelength range of the spectral response (320-1100nm);

[0028] 4. The super-hydrophobic self-healing polyurethane film for photovoltaics prepared by the present invention can be pre-attached or post-attached; replacement only requires removing the old film and attaching the new film, which is simple and convenient to operate, easy to construct on site, simple and convenient to rework later, and has a high tolerance for the construction environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, some of the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be made based on these drawings without paying any creative work.

[0030] Figure 1 This is a schematic diagram of the self-repairing of a super-hydrophobic self-repairing polyurethane film according to Example 1 of the present invention;

[0031] Figure 2 This is a schematic diagram of super-hydrophobic self-repairing polyurethane film super-hydrophobic self-cleaning in Example 1 of the present invention;

[0032] Among them, 1. self-healing superphobic material; 2. self-healing group; 3. damaged part; 4. superphobic layer; 5. substrate; 6. contamination. DETAILED DESCRIPTION

[0033] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, a specific implementation scheme is now described in detail.

[0034] The present invention is further described below in conjunction with the examples, but the present invention is not limited to the following examples. The implementation conditions used in the examples can be further adjusted according to the different requirements of specific use, and the implementation conditions not indicated are conventional conditions in the industry. The technical features involved in each embodiment of the present invention can be combined with each other as long as they do not conflict with each other.

[0035] Example 1

[0036] See attached Figure 1 And attached Figure 2, This embodiment provides a super-hydrophobic self-healing polyurethane film for photovoltaics and a preparation method thereof, wherein the super-hydrophobic self-healing polyurethane film for photovoltaics comprises the following components by weight: 20 parts of polytetramethylene glycol (molecular weight 2000), 6 parts of diphenylmethane diisocyanate (MDI), 0.08 parts of dilauryl dibutyltin, 4 parts of 4,4'-dithiodiphenylamine, 15 parts of N,N-dimethylformamide, 1 part of ethylene glycol, and 8 parts of hydrophobic nanoparticles;

[0037] The method for preparing the super-hydrophobic self-healing polyurethane film for photovoltaics comprises the following steps:

[0038] S1, dehydrate polytetrahydrofuran diol in a 110 ℃ vacuum drying oven for 2 hours, take it out, seal and cool to room temperature for use;

[0039] S2, 20 parts of dehydrated polytetrahydrofuran diol and 6 parts of isocyanate were mixed uniformly, 0.08 parts of dibutyltin dilaurate were added under nitrogen atmosphere protection, and polymerization was carried out at 75°C and 300r / min for 2 hours. During the reaction, a small amount of bubbles appeared in the material to obtain a uniformly mixed polyurethane prepolymer;

[0040] S3, adding 4 parts of 4,4'-dithiodiphenylamine and 15 parts of N,N-dimethylformamide to the uniformly mixed polyurethane prepolymer obtained in step S2, and continuing the reaction at 75° C. for 5 hours to obtain a polyurethane solution with self-healing properties;

[0041] S4, raising the temperature of the polyurethane solution with self-repairing properties obtained in step S3 to 80° C., adding 1 part of ethylene glycol to carry out chain extension reaction, and reacting for 30 minutes to obtain a self-repairing polyurethane film material with a high degree of polymerization;

[0042] S5. Add 20 parts of hydrochloric acid (HCl) and 4 parts of tetraethyl orthosilicate (TEOS) into a reaction bottle and stir for 5 hours to obtain solution A; seal and stir 1 part of heptadecafluorodecyltrimethoxysilane (PFDMS) and 25 parts of anhydrous ethanol (C2H5OH) for 10 minutes to obtain solution B; fully stir A and B until PFDMS is completely hydrolyzed; A+B+250mL anhydrous ethanol (C2H5OH), adjust the pH, and co-condense to obtain solution C. After the reaction is completed, collect the precipitate by centrifugation, and rinse with anhydrous ethanol (C2H5OH) to obtain superhydrophobic nanoparticles;

[0043] The high-polymerization self-healing polyurethane film material obtained in step S4 is mixed with 8 parts of super-hydrophobic nanoparticles, and then vacuum-dried in an oven at 60° C. for 12 hours, and then the temperature is raised to 100° C. and vacuum-dried for 12 hours to obtain the super-hydrophobic self-healing polyurethane film for photovoltaics;

[0044] like Figure 1 and Figure 2 As shown, this photovoltaic transparent super-hydrophobic self-healing material includes a self-healing super-hydrophobic material (1). When the main body of the self-healing super-hydrophobic material (1) has a damaged part (3), the self-healing group (2) in the main body will automatically repair the damaged part (3) until it is "healed"; this transparent super-hydrophobic self-healing material has a super-hydrophobic layer (4) on its surface. When the surface of the material is attached with dirt (6), it can be self-cleaned by the flushing of rainwater; and this self-healing super-hydrophobic material (1) itself is easy to rework. When there is a need for rework, it can be peeled off from the substrate (5) at any time and a new material can be attached.

[0045] Example 2

[0046] The present embodiment provides a super-hydrophobic self-healing polyurethane film for photovoltaics and a preparation method thereof. The super-hydrophobic self-healing polyurethane film for photovoltaics comprises the following components by weight: 20 parts of polytetramethylene glycol (molecular weight 2000), 6 parts of diphenylmethane diisocyanate (MDI), 0.08 parts of dilauryl dibutyltin, 4 parts of 4,4'-dithiodiphenylamine, 15 parts of N,N-dimethylformamide, 1 part of ethylene glycol, and 5 parts of hydrophobic nanoparticles;

[0047] The method for preparing the super-hydrophobic self-healing polyurethane film for photovoltaics comprises the following steps:

[0048] S1, dehydrate polytetrahydrofuran diol in a 110 ℃ vacuum drying oven for 2 hours, take it out, seal and cool to room temperature for use;

[0049] S2, 20 parts of dehydrated polytetrahydrofuran diol and 6 parts of isocyanate were mixed uniformly, 0.08 parts of dibutyltin dilaurate were added under nitrogen atmosphere protection, and polymerization was carried out at 75°C and 300r / min for 2 hours. During the reaction, a small amount of bubbles appeared in the material to obtain a uniformly mixed polyurethane prepolymer;

[0050] S3, adding 4 parts of 4,4'-dithiodiphenylamine and 15 parts of N,N-dimethylformamide to the uniformly mixed polyurethane prepolymer obtained in step S2, and continuing the reaction at 75° C. for 5 hours to obtain a polyurethane solution with self-healing properties;

[0051] S4, raising the temperature of the polyurethane solution with self-repairing properties obtained in step S3 to 80° C., adding 1 part of ethylene glycol to carry out chain extension reaction, and reacting for 30 minutes to obtain a self-repairing polyurethane film material with a high degree of polymerization;

[0052] S5. Add 20 parts of hydrochloric acid (HCl) and 4 parts of tetraethyl orthosilicate (TEOS) into a reaction bottle and stir for 5 hours to obtain solution A; seal and stir 1 part of heptadecafluorodecyltrimethoxysilane (PFDMS) and 25 parts of anhydrous ethanol (C2H5OH) for 10 minutes to obtain solution B; fully stir A and B until PFDMS is completely hydrolyzed; A+B+250mL anhydrous ethanol (C2H5OH), adjust the pH, and co-condense to obtain solution C. After the reaction is completed, collect the precipitate by centrifugation, and rinse with anhydrous ethanol (C2H5OH) to obtain superhydrophobic nanoparticles;

[0053] The high-polymerization self-healing polyurethane film material obtained in step S4 was mixed with 5 parts of super-hydrophobic nanoparticles, and then vacuum-dried in an oven at 60° C. for 12 hours, and then the temperature was raised to 100° C. and vacuum-dried for 12 hours to obtain the super-hydrophobic self-healing polyurethane film for photovoltaics.

[0054] Example 3

[0055] The present embodiment provides a super-hydrophobic self-healing polyurethane film for photovoltaics and a preparation method thereof. The super-hydrophobic self-healing polyurethane film for photovoltaics comprises the following components by weight: 20 parts of polytetramethylene glycol (molecular weight 2000), 6 parts of diphenylmethane diisocyanate (MDI), 0.08 parts of dilauryl dibutyltin, 4 parts of 4,4'-dithiodiphenylamine, 15 parts of N,N-dimethylformamide, 1 part of ethylene glycol, and 3 parts of hydrophobic nanoparticles;

[0056] The method for preparing the super-hydrophobic self-healing polyurethane film for photovoltaics comprises the following steps:

[0057] S1, dehydrate polytetrahydrofuran diol in a 110 ℃ vacuum drying oven for 2 hours, take it out, seal and cool to room temperature for use;

[0058] S2, 20 parts of dehydrated polytetrahydrofuran diol and 6 parts of isocyanate were mixed uniformly, 0.08 parts of dibutyltin dilaurate were added under nitrogen atmosphere protection, and polymerization was carried out at 75°C and 300r / min for 2 hours. During the reaction, a small amount of bubbles appeared in the material to obtain a uniformly mixed polyurethane prepolymer;

[0059] S3, adding 4 parts of 4,4'-dithiodiphenylamine and 15 parts of N,N-dimethylformamide to the uniformly mixed polyurethane prepolymer obtained in step S2, and continuing the reaction at 75° C. for 5 hours to obtain a polyurethane solution with self-healing properties;

[0060] S4, raising the temperature of the polyurethane solution with self-repairing properties obtained in step S3 to 80° C., adding 1 part of ethylene glycol to carry out chain extension reaction, and reacting for 30 minutes to obtain a self-repairing polyurethane film material with a high degree of polymerization;

[0061] S5. Add 20 parts of hydrochloric acid (HCl) and 4 parts of tetraethyl orthosilicate (TEOS) into a reaction bottle and stir for 5 hours to obtain solution A; seal and stir 1 part of heptadecafluorodecyltrimethoxysilane (PFDMS) and 25 parts of anhydrous ethanol (C2H5OH) for 10 minutes to obtain solution B; fully stir A and B until PFDMS is completely hydrolyzed; A+B+250mL anhydrous ethanol (C2H5OH), adjust the pH, and co-condense to obtain solution C. After the reaction is completed, collect the precipitate by centrifugation, and rinse with anhydrous ethanol (C2H5OH) to obtain superhydrophobic nanoparticles;

[0062] The high-polymerization self-healing polyurethane film material obtained in step S4 was mixed with 3 parts of super-hydrophobic nanoparticles, and then vacuum-dried in an oven at 60° C. for 12 hours, and then the temperature was raised to 100° C. and vacuum-dried for 12 hours to obtain the super-hydrophobic self-healing polyurethane film for photovoltaics.

[0063] Comparative Example 1

[0064] The present embodiment provides a super-hydrophobic self-healing polyurethane film for photovoltaics and a preparation method thereof. The super-hydrophobic self-healing polyurethane film for photovoltaics comprises the following components by weight: 20 parts of polytetramethylene glycol (molecular weight 2000), 6 parts of diphenylmethane diisocyanate (MDI), 0.08 parts of dilauryl dibutyltin, 2 parts of 4,4'-dithiodiphenylamine, 15 parts of N,N-dimethylformamide, 1 part of ethylene glycol, and 5 parts of hydrophobic nanoparticles;

[0065] The method for preparing the super-hydrophobic self-healing polyurethane film for photovoltaics comprises the following steps:

[0066] S1, dehydrate polytetrahydrofuran diol in a 110 ℃ vacuum drying oven for 2 hours, take it out, seal and cool to room temperature for use;

[0067] S2, 20 parts of dehydrated polytetrahydrofuran diol and 6 parts of isocyanate were mixed uniformly, 0.08 parts of dibutyltin dilaurate were added under nitrogen atmosphere protection, and polymerization was carried out at 75°C and 300r / min for 2 hours. During the reaction, a small amount of bubbles appeared in the material to obtain a uniformly mixed polyurethane prepolymer;

[0068] S3, adding 2 parts of 4,4'-dithiodiphenylamine and 15 parts of N,N-dimethylformamide to the uniformly mixed polyurethane prepolymer obtained in step S2, and continuing the reaction at 75° C. for 5 hours to obtain a polyurethane solution with self-healing properties;

[0069] S4, raising the temperature of the polyurethane solution with self-repairing properties obtained in step S3 to 80° C., adding 1 part of ethylene glycol to carry out chain extension reaction, and reacting for 30 minutes to obtain a self-repairing polyurethane film material with a high degree of polymerization;

[0070] S5. Add 20 parts of hydrochloric acid (HCl) and 4 parts of tetraethyl orthosilicate (TEOS) into a reaction bottle and stir for 5 hours to obtain solution A; seal and stir 1 part of heptadecafluorodecyltrimethoxysilane (PFDMS) and 25 parts of anhydrous ethanol (C2H5OH) for 10 minutes to obtain solution B; fully stir A and B until PFDMS is completely hydrolyzed; A+B+250mL anhydrous ethanol (C2H5OH), adjust the pH, and co-condense to obtain solution C. After the reaction is completed, collect the precipitate by centrifugation, and rinse with anhydrous ethanol (C2H5OH) to obtain superhydrophobic nanoparticles;

[0071] The high-polymerization self-healing polyurethane film material obtained in step S4 was mixed with 5 parts of super-hydrophobic nanoparticles, and then vacuum-dried in an oven at 60° C. for 12 hours, and then the temperature was raised to 100° C. and vacuum-dried for 12 hours to obtain the super-hydrophobic self-healing polyurethane film for photovoltaics.

[0072] Comparative Example 2

[0073] The present embodiment provides a super-hydrophobic self-healing polyurethane film for photovoltaics and a preparation method thereof. The super-hydrophobic self-healing polyurethane film for photovoltaics comprises the following components by weight: 20 parts of polytetramethylene glycol (molecular weight 2000), 6 parts of diphenylmethane diisocyanate (MDI), 0.08 parts of dilauryl dibutyltin, 4 parts of 4,4'-dithiodiphenylamine, 15 parts of N,N-dimethylformamide, 1 part of ethylene glycol, and 1 part of hydrophobic nanoparticles;

[0074] The method for preparing the super-hydrophobic self-healing polyurethane film for photovoltaics comprises the following steps:

[0075] S1, dehydrate polytetrahydrofuran diol in a 110 ℃ vacuum drying oven for 2 hours, take it out, seal and cool to room temperature for use;

[0076] S2, 20 parts of dehydrated polytetrahydrofuran diol and 6 parts of isocyanate were mixed uniformly, 0.08 parts of dibutyltin dilaurate were added under nitrogen atmosphere protection, and polymerization was carried out at 75°C and 300r / min for 2 hours. During the reaction, a small amount of bubbles appeared in the material to obtain a uniformly mixed polyurethane prepolymer;

[0077] S3, adding 4 parts of 4,4'-dithiodiphenylamine and 15 parts of N,N-dimethylformamide to the uniformly mixed polyurethane prepolymer obtained in step S2, and continuing the reaction at 75° C. for 5 hours to obtain a polyurethane solution with self-healing properties;

[0078] S4, raising the temperature of the polyurethane solution with self-repairing properties obtained in step S3 to 80° C., adding 1 part of ethylene glycol to carry out chain extension reaction, and reacting for 30 minutes to obtain a self-repairing polyurethane film material with a high degree of polymerization;

[0079] S5. Add 20 parts of hydrochloric acid (HCl) and 4 parts of tetraethyl orthosilicate (TEOS) into a reaction bottle and stir for 5 hours to obtain solution A; seal and stir 1 part of heptadecafluorodecyltrimethoxysilane (PFDMS) and 25 parts of anhydrous ethanol (C2H5OH) for 10 minutes to obtain solution B; fully stir A and B until PFDMS is completely hydrolyzed; A+B+250mL anhydrous ethanol (C2H5OH), adjust the pH, and co-condense to obtain solution C. After the reaction is completed, collect the precipitate by centrifugation, and rinse with anhydrous ethanol (C2H5OH) to obtain superhydrophobic nanoparticles;

[0080] The high-polymerization self-healing polyurethane film material obtained in step S4 is mixed with 1 part of super-hydrophobic nanoparticles, and then vacuum-dried in an oven at 60° C. for 12 hours, and then the temperature is raised to 100° C. and vacuum-dried for 12 hours to obtain the super-hydrophobic self-healing polyurethane film for photovoltaics.

[0081] The super-hydrophobic self-healing polyurethane films for photovoltaics prepared in the above-mentioned embodiments and comparative examples were tested, and the test results are shown in Table 1.

[0082] Table 1

[0083] Test items Hydrophobic angle (°) Roll angle (°) Self-repair efficiency (%) Transmittance (%) Example 1 160 3 95 92 Example 2 150 5 92 95 Example 3 140 3 88 96 Comparative Example 1 150 5 80 95 Comparative Example 2 130 13 94 98

[0084] As shown in Table 1, when too little hydrophobic nanoparticles are added, the hydrophobic performance of the composite film material is poor. When too much hydrophobic nanoparticles are added, the self-healing efficiency of the composite film is reduced. This is because too much filler hinders the polyurethane molecular chain, which in turn affects the re-entanglement of the disulfide bonds and reduces the self-healing efficiency. When the amount of self-healing additive is used less, the self-healing efficiency is also reduced.

[0085] In summary, the present invention introduces a self-repairing auxiliary agent to make the composite film have self-repairing properties, improves the service life and durability of the composite material, and can self-heal after the material is damaged by the outside world. On the basis of self-repair, hydrophobic nanoparticles are added to realize super-hydrophobic surface. The present invention mixes hydrophobic nanoparticles with self-repairing polyurethane by physical blending, and under the premise of not affecting self-repairing properties, the composite material can also be made to have super-hydrophobicity. The transparent polyurethane film material for photovoltaic panels of the present invention can be pasted by electrostatic adsorption or other adhesives, so that the film material is loaded on the photovoltaic panel, and a protective effect is played to the photovoltaic panel to prevent damage to the photovoltaic panel due to external environmental pollution.

[0086] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A super-hydrophobic self-healing polyurethane film for photovoltaics, characterized in that: The composition comprises the following components by weight: 10 to 35 parts of polyether polyol, 3 to 15 parts of isocyanate, 0.04 to 1 part of catalyst, 10 to 20 parts of solvent, 2 to 6 parts of self-healing agent, 0.5 to 5 parts of chain extender and 0.1 to 10 parts of super hydrophobic nanoparticles.

2. A super hydrophobic self-healing polyurethane film for photovoltaics according to claim 1, characterized in that: The super hydrophobic nanoparticles are fluorosilicone polymer nanoparticles, which are modified hydrophobic nanoparticles obtained by hydrolyzing two or more organic silicons and then introducing CF bonds through co-condensation to achieve fluorination modification.

3. A super-hydrophobic self-healing polyurethane film for photovoltaics according to claim 1, characterized in that: The molecular weight of the polyether polyol is 1000-2000, and the polyether polyol is selected from one or more of polytetramethylene glycol, polypropylene glycol, and tetramethylene glycol-propylene oxide copolymer.

4. A super-hydrophobic self-healing polyurethane film for photovoltaics according to claim 1, characterized in that: The isocyanate is selected from one or more of isophorone diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, toluene diisocyanate and diphenylmethane diisocyanate.

5. A super-hydrophobic self-healing polyurethane film for photovoltaics according to claim 1, characterized in that: The catalyst is selected from one or more of dibutyltin dilaurate, N,N-dimethylcyclohexylamine, bis(2-dimethylaminoethyl) ether, triethylamine, N,N-dimethylbenzylamine, N-ethylmorpholine, N-methylmorpholine, triethanolamine, and N,N-dimethylpyridine.

6. A super-hydrophobic self-healing polyurethane film for photovoltaics according to claim 1, characterized in that: The solvent is selected from one or more of N,N-dimethylformamide, N-methylpyrrolidone and dichloromethane.

7. A super-hydrophobic self-healing polyurethane film for photovoltaics according to claim 1, characterized in that: The chain extender is selected from one or more of 1,4-butanediol, ethylene glycol, diethanolamine, and hydroquinone dihydroxyethyl ether.

8. A super-hydrophobic self-healing polyurethane film for photovoltaics according to claim 1, characterized in that: The self-repairing agent is a disulfide bond-containing self-repairing agent, and the self-repairing agent is selected from one or more of 4,4'-dithiodiphenylamine, bis(2-hydroxyethyl) disulfide, and 2,2-dithiodiphenylamine.

9. The method for preparing a super-hydrophobic self-healing polyurethane film for photovoltaics according to any one of claims 1 to 8, characterized in that: The steps include: S1. Dehydrate the polyether polyol in a vacuum drying oven at 100-120°C for 2-3 hours, take it out, seal it and cool it to room temperature for use; S2, mixing the dehydrated polyether polyol and isocyanate uniformly, adding a catalyst under the protection of a nitrogen atmosphere, and performing a polymerization reaction at 75-80° C. and 300-350 r / min for 2-4 hours to obtain a uniformly mixed polyurethane prepolymer; S3, adding a self-repairing agent and a solvent to the uniformly mixed polyurethane prepolymer obtained in step S2, and continuing the reaction at 75 to 80° C. for 5 to 7 hours to obtain a polyurethane solution with self-repairing properties; S4, raising the temperature of the polyurethane solution with self-repairing properties obtained in step S3 to 80-85° C., adding a chain extender to carry out a chain extension reaction, and reacting for 30-35 minutes to obtain a self-repairing polyurethane film material with a high degree of polymerization; S5. After mixing the self-healing polyurethane film material with a high degree of polymerization obtained in step S4 with the super-hydrophobic nanoparticles, vacuum-drying the mixture in an oven at 60 to 70° C. for 12 to 16 hours, and then raising the temperature to 100 to 110° C. and vacuum-drying the mixture for 12 to 16 hours to obtain the super-hydrophobic self-healing polyurethane film for photovoltaics.

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