Coated photovoltaic glass and method for its production

Abstract

The application relates to the technical field of photovoltaic glass, and discloses a coated photovoltaic glass and a preparation method thereof, wherein acrylic resin, modified nano titanium dioxide, fluorine-containing flame retardant, modified cellulose and shellac are added into a mixing device, mixed, and a coating solution is obtained; the prepared coating solution is coated on the surface of one side of a glass substrate by using a roll coating method, then low-temperature solidification is carried out to form a composite protective layer, and after the coating is completed, cleaning treatment is carried out, so that the coated photovoltaic glass is obtained. The coated photovoltaic glass has good flame retardation, impact resistance and weather resistance.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic glass technology, specifically to a coated photovoltaic glass and its preparation method. Background Technology

[0002] As a crucial component of solar cell modules, photovoltaic glass directly impacts the efficiency and lifespan of solar cells. However, existing photovoltaic glass has certain shortcomings in weather resistance and fire resistance, especially in harsh environments such as high temperature and high humidity, where it is prone to aging and cracking, affecting the overall performance and reliability of photovoltaic modules. Furthermore, traditional photovoltaic glass also has limitations in flame retardancy, failing to meet the high safety requirements of materials in modern building and industrial applications. Therefore, avoiding these issues is key to solving the problem. For example, patent CN1151409747B discloses a coated photovoltaic glass and its preparation method, which improves the hydrophobicity of the photovoltaic glass surface, but its flame retardant properties remain unimproved. Summary of the Invention

[0003] (a) Technical problems to be solved

[0004] To address the shortcomings of existing technologies, this invention provides a coated photovoltaic glass and its preparation method, which has good flame retardant, impact resistance, and weather resistance properties.

[0005] (II) Technical Solution

[0006] To achieve the above objectives, the present invention provides the following technical solution: a coated photovoltaic glass, comprising a glass substrate and a composite protective layer disposed on the glass substrate, wherein the raw materials of the composite protective layer include, by weight: 60-70 parts by weight of acrylic resin, 1-2 parts by weight of modified nano titanium dioxide, 0.1-0.3 parts by weight of fluorinated flame retardant, 0.2-0.5 parts by weight of modified cellulose, and 2-4 parts by weight of shellac.

[0007] Further, the modified nano-titanium dioxide is prepared by mixing 40 mL of isopropanol and 5 mL of deionized water, then adding 1.4-1.8 g of γ-methacryloxypropyltrimethoxysilane coupling agent, stirring for 50-60 min, and then adding 12.6-13 g of nano-titanium dioxide. The mixture is reacted at 75-80 °C for 4-6 h, and then dried to obtain alkenylated nano-titanium dioxide.

[0008] Furthermore, the preparation method of the fluorinated flame retardant is as follows:

[0009] S1. Under inert gas, 4,4'-diaminodiphenyl sulfone and triethylamine are added to a reactor containing acetonitrile solvent, the temperature is raised to 40-45℃ and stirred for 0.4-0.5 h, then phenylphosphine dichloride is added, and the reaction is carried out at 70-75℃ for 12-16 h. After the reaction is completed, the mixture is cooled to room temperature, the solvent is eluted with methyl tert-butyl ether, and the mixture is filtered to obtain intermediate 1.

[0010] S2. Add perfluorooctanoyl chloride and intermediate 1 to N,N-dimethylformamide solvent, stir and mix, continue to add pyridine catalyst, react at 75-85℃ for 6-8h, after which vacuum distillation and washing are performed to obtain fluorinated flame retardant.

[0011] Further, the ratio of acetonitrile, 4,4'-diaminodiphenyl sulfone, triethylamine, and phenylphosphine dichloride in S1 is 50-60 mL: 6.21-6.34 g: 0.01-0.02 g: 7.51-7.54 g.

[0012] Furthermore, the ratio of N,N-dimethylformamide, perfluorooctanoyl chloride, intermediate 1, and pyridine catalyst in S2 is 45-55 mL: 8.12-8.54 g: 4.1-4.3 g: 0.012-0.015 g.

[0013] Furthermore, the method for preparing the modified cellulose is as follows:

[0014] Step 1: Mix 2-(dodecyltrithiocarbonate)-2-methylpropionic acid, oxaloyl chloride and dichloromethane, stir at a stirring rate of 140-160 rpm at room temperature, add ethyl acetate, react for 6-9 h, and then rotary evaporate to obtain the intermediate.

[0015] Step 2: Mix nanocellulose and N,N-dimethylacetamide at a stirring speed of 140-180 rpm and a temperature of 120-140℃ for 2-3 hours. Then add lithium chloride and stir at a temperature of 80-85℃ for 10-12 hours. Next, add triethylamine and an intermediate and stir at room temperature for 20-22 hours. Finally, add methanol, filter, wash, and dry to obtain modified cellulose.

[0016] In the above reaction process, under the action of oxalyl chloride, the carboxyl group in 2-(dodecyltrithiocarbonate)-2-methylpropionic acid is acyl-chlorinated to obtain an intermediate. Then, in the N,N-dimethylacetamide / lithium chloride system, the hydroxyl group in nanocellulose reacts with the acyl chloride group in the intermediate, and triethylamine is used as an acid-binding agent to obtain modified cellulose.

[0017] Furthermore, in step one, the ratio of 2-(dodecyltrithiocarbonate)-2-methylpropionic acid, oxaloyl chloride, dichloromethane, and ethyl acetate is 4.2-4.4g: 2.5-2.9g: 30-40mL: 1.2-1.6mL.

[0018] Furthermore, in step two, the ratio of nanocellulose, N,N-dimethylacetamide, lithium chloride, triethylamine, and intermediate is 0.96-1.02g: 50-55mL: 2.5-2.65g: 1.35-1.42g: 0.28-0.33g.

[0019] Further, the preparation method of the coated photovoltaic glass is as follows: acrylic resin, modified nano titanium dioxide, fluorinated flame retardant, modified cellulose, and shellac are added to a mixing device and mixed at a speed of 400-450 r / min and at 35-40℃ for 25-35 min to obtain a coating solution; the prepared coating solution is coated on the surface of one side of the glass substrate using a roller coating method, and then cured at low temperature to form a composite protective layer. After the coating is completed, a cleaning treatment is performed to obtain the coated photovoltaic glass.

[0020] (iii) Beneficial technical effects

[0021] This invention involves mixing acrylic resin, modified nano-titanium dioxide, fluorinated flame retardant, modified cellulose, and shellac in a mixing device to obtain a coating solution. The coating solution is then applied to one side of a glass substrate using a roller coating method, followed by low-temperature curing to form a composite protective layer. After coating, the substrate is cleaned to obtain coated photovoltaic glass.

[0022] Modified nano-titanium dioxide in coated photovoltaic glass enhances the composite layer's UV resistance and extends the glass's lifespan. The phosphorus and sulfur elements in the fluorinated flame retardant and modified cellulose exhibit good flame-retardant effects. When heated, phosphorus produces acidic substances such as phosphoric acid and metaphosphoric acid, promoting dehydration and carbonization. These acidic substances can further polyphosphate coat the material surface, contributing to flame retardancy. Sulfur promotes the formation of a char layer on the polymer surface at high temperatures. This char layer acts as a barrier against heat and oxygen, slowing the combustion process and thus providing flame retardancy. The acrylic resin, modified cellulose, and fluorinated flame retardant intertwine, creating a tighter molecular cross-linked network that increases mechanical properties and disperses more force when subjected to impact. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] All raw materials used in the following examples and comparative examples are chemically pure, and the molecular weight of the acrylic resin used is 10,000.

[0025] Example 1

[0026] A coated photovoltaic glass includes a glass substrate and a composite protective layer disposed on the glass substrate. The raw materials of the composite protective layer include, by weight, 60 parts of acrylic resin, 1 part of modified nano-titanium dioxide, 0.1 parts of fluorinated flame retardant, 0.2 parts of modified cellulose, and 2 parts of shellac.

[0027] The modified nano-titanium dioxide is prepared by mixing 40 mL of isopropanol and 5 mL of deionized water, then adding 1.4 g of γ-methacryloyloxypropyltrimethoxysilane, stirring for 50 min, and then adding 12.6 g of nano-titanium dioxide. The mixture is reacted at 75 °C for 4 h and dried to obtain alkenylated nano-titanium dioxide.

[0028] The preparation method of the fluorinated flame retardant is as follows:

[0029] S1. Under nitrogen atmosphere, 6.21 g of 4,4'-diaminodiphenyl sulfone and 0.01 g of triethylamine were added to a reactor containing 50 mL of acetonitrile. The mixture was heated to 40 °C and stirred for 0.4 h. Then, 7.51 g of phenylphosphine dichloride was added, and the mixture was reacted at 70 °C for 12 h. After the reaction was completed, the mixture was cooled to room temperature, eluted with methyl tert-butyl ether, and filtered to obtain intermediate 1.

[0030] S2. Add 8.12 g of perfluorooctanoic acid chloride and 4.1 g of intermediate 1 to 45 mL of N,N-dimethylformamide, stir and mix, then add 0.012 g of pyridine, react at 75 °C for 6 h, after which distill under reduced pressure and wash to obtain a fluorinated flame retardant.

[0031] The method for preparing the modified cellulose is as follows:

[0032] Step 1: Mix 4.2g of 2-(dodecyltrithiocarbonyl)-2-methylpropionic acid, 2.5g of oxaloyl chloride and 30mL of dichloromethane. Stir at 140rpm at room temperature and add 1.2mL of ethyl acetate. React for 6h and then rotary evaporate to obtain the intermediate.

[0033] Step 2: Mix 0.96g of nanocellulose and 50mL of N,N-dimethylacetamide, stir at 140rpm and 120℃ for 2h, then add 2.5g of lithium chloride, stir at 80℃ for 10h, then add 1.35g of triethylamine and 0.28g of intermediate, stir at room temperature for 20h, then add methanol, filter, wash, and dry to obtain modified cellulose.

[0034] The method for preparing the coated photovoltaic glass is as follows: acrylic resin, modified nano titanium dioxide, fluorinated flame retardant, modified cellulose, and shellac are added to a mixing device and mixed at 400 r / min and 35°C for 25 min to obtain a coating solution; the prepared coating solution is coated on one side of the glass substrate using a roller coating method, and then cured at low temperature to form a composite protective layer; after coating is completed, a cleaning process is performed to obtain the coated photovoltaic glass.

[0035] Example 2

[0036] A coated photovoltaic glass includes a glass substrate and a composite protective layer disposed on the glass substrate. The raw materials of the composite protective layer include, by weight, 70 parts of acrylic resin, 2 parts of modified nano-titanium dioxide, 0.3 parts of fluorine-containing flame retardant, 0.5 parts of modified cellulose, and 4 parts of shellac.

[0037] The modified nano-titanium dioxide is prepared by mixing 40 mL of isopropanol and 5 mL of deionized water, then adding 1.8 g of γ-methacryloyloxypropyltrimethoxysilane, stirring for 60 min, then adding 13 g of nano-titanium dioxide, reacting at 80 °C for 6 h, and drying to obtain alkenylated nano-titanium dioxide.

[0038] The preparation method of the fluorinated flame retardant is as follows:

[0039] S1. Under nitrogen atmosphere, 6.34 g of 4,4'-diaminodiphenyl sulfone and 0.02 g of triethylamine were added to a reactor containing 60 mL of acetonitrile. The mixture was heated to 45 °C and stirred for 0.5 h. Then, 7.54 g of phenylphosphine dichloride was added, and the mixture was reacted at 75 °C for 16 h. After the reaction was completed, the mixture was cooled to room temperature, eluted with methyl tert-butyl ether, and filtered to obtain intermediate 1.

[0040] S2. Add 8.54 g of perfluorooctanoic acid chloride and 4.3 g of intermediate 1 to 55 mL of N,N-dimethylformamide, stir and mix, then add 0.015 g of pyridine, react at 85 °C for 8 h, and after the reaction is completed, distill under reduced pressure and wash to obtain a fluorinated flame retardant.

[0041] The method for preparing the modified cellulose is as follows:

[0042] Step 1: Mix 4.4 g of 2-(dodecyltrithiocarbonyl)-2-methylpropionic acid, 2.9 g of oxaloyl chloride and 40 mL of dichloromethane. Stir at 160 rpm at room temperature and add 1.6 mL of ethyl acetate. React for 9 h and then rotary evaporate to obtain the intermediate.

[0043] Step 2: Mix 1.02g of nanocellulose and 55mL of N,N-dimethylacetamide, and stir for 3h at a stirring speed of 180rpm and a temperature of 140℃. Then add 2.65g of lithium chloride and stir for 12h at a temperature of 85℃. Then add 1.42g of triethylamine and 0.33g of intermediate and stir for 22h at room temperature. Then add methanol, filter, wash, and dry to obtain modified cellulose.

[0044] The method for preparing the coated photovoltaic glass is as follows: acrylic resin, modified nano titanium dioxide, fluorinated flame retardant, modified cellulose, and shellac are added to a mixing device and mixed at 450 r / min and 40℃ for 35 min to obtain a coating solution; the prepared coating solution is coated on one side of the glass substrate using a roller coating method, and then cured at low temperature to form a composite protective layer; after coating is completed, a cleaning treatment is performed to obtain the coated photovoltaic glass.

[0045] Example 3

[0046] A coated photovoltaic glass includes a glass substrate and a composite protective layer disposed on the glass substrate. The raw materials of the composite protective layer include, by weight, 65 parts acrylic resin, 1.5 parts modified nano titanium dioxide, 0.2 parts fluorinated flame retardant, 0.3 parts modified cellulose, and 3 parts shellac.

[0047] The modified nano-titanium dioxide is prepared by mixing 40 mL of isopropanol and 5 mL of deionized water, then adding 1.6 g of γ-methacryloxypropyltrimethoxysilane coupling agent, stirring for 55 min, and then adding 12.8 g of nano-titanium dioxide. The mixture is reacted at 76 °C for 5 h and then dried to obtain alkenylated nano-titanium dioxide.

[0048] The preparation method of the fluorinated flame retardant is as follows:

[0049] S1. Under nitrogen atmosphere, 6.24 g of 4,4'-diaminodiphenyl sulfone and 0.015 g of triethylamine were added to a reactor containing 55 mL of acetonitrile. The mixture was heated to 43 °C and stirred for 0.45 h. Then, 7.52 g of phenylphosphine dichloride was added, and the mixture was reacted at 72 °C for 14 h. After the reaction was completed, the mixture was cooled to room temperature, eluted with methyl tert-butyl ether, and filtered to obtain intermediate 1.

[0050] S2. Add 8.37 g of perfluorooctanoic acid chloride and 4.2 g of intermediate 1 to 50 mL of N,N-dimethylformamide, stir and mix, then add 0.014 g of pyridine, react at 80 °C for 7 h, and after the reaction is completed, distill under reduced pressure and wash to obtain a fluorinated flame retardant.

[0051] The method for preparing the modified cellulose is as follows:

[0052] Step 1: Mix 4.3g of 2-(dodecyltrithiocarbonyl)-2-methylpropionic acid, 2.8g of oxaloyl chloride and 35mL of dichloromethane. Stir at 150rpm at room temperature and add 1.4mL of ethyl acetate. React for 7h and then rotary evaporate to obtain the intermediate.

[0053] Step 2: Mix 0.97g of nanocellulose and 52mL of N,N-dimethylacetamide, and stir for 2.5h at a stirring rate of 160rpm and a temperature of 130℃. Then add 2.63g of lithium chloride and stir for 11h at a temperature of 82℃. Then add 1.38g of triethylamine and 0.31g of intermediate and stir for 21h at room temperature. Then add methanol, filter, wash, and dry to obtain modified cellulose.

[0054] The method for preparing the coated photovoltaic glass is as follows: acrylic resin, modified nano titanium dioxide, fluorinated flame retardant, modified cellulose, and shellac are added to a mixing device and mixed at 38°C for 30 minutes at a rotation speed of 420 r / min to obtain a coating solution; the prepared coating solution is coated on one side of the glass substrate using a roller coating method, and then cured at low temperature to form a composite protective layer; after coating is completed, a cleaning process is performed to obtain the coated photovoltaic glass.

[0055] Example 4

[0056] A coated photovoltaic glass includes a glass substrate and a composite protective layer disposed on the glass substrate. The raw materials of the composite protective layer include, by weight, 60 parts of acrylic resin, 1 part of modified nano-titanium dioxide, 0.1 parts of fluorinated flame retardant, 0.2 parts of modified cellulose, and 2 parts of shellac.

[0057] The modified nano-titanium dioxide is prepared by mixing 40 mL of isopropanol and 5 mL of deionized water, then adding 1.4 g of γ-methacryloxypropyltrimethoxysilane coupling agent, stirring for 50 min, and then adding 12.6 g of nano-titanium dioxide. The mixture is reacted at 75 °C for 4 h and dried to obtain alkenylated nano-titanium dioxide.

[0058] The preparation method of the fluorinated flame retardant is as follows:

[0059] S1. Under nitrogen atmosphere, 6.34 g of 4,4'-diaminodiphenyl sulfone and 0.02 g of triethylamine were added to a reactor containing 60 mL of acetonitrile. The mixture was heated to 45 °C and stirred for 0.5 h. Then, 7.54 g of phenylphosphine dichloride was added, and the mixture was reacted at 75 °C for 16 h. After the reaction was completed, the mixture was cooled to room temperature, eluted with methyl tert-butyl ether, and filtered to obtain intermediate 1.

[0060] S2. Add 8.54 g of perfluorooctanoic acid chloride and 4.3 g of intermediate 1 to 55 mL of N,N-dimethylformamide, stir and mix, then add 0.015 g of pyridine, react at 85 °C for 8 h, and after the reaction is completed, distill under reduced pressure and wash to obtain a fluorinated flame retardant.

[0061] The method for preparing the modified cellulose is as follows:

[0062] Step 1: Mix 4.3g of 2-(dodecyltrithiocarbonyl)-2-methylpropionic acid, 2.8g of oxaloyl chloride and 35mL of dichloromethane. Stir at 150rpm at room temperature and add 1.4mL of ethyl acetate. React for 7h and then rotary evaporate to obtain the intermediate.

[0063] Step 2: Mix 0.97g of nanocellulose and 52mL of N,N-dimethylacetamide, and stir for 2.5h at a stirring rate of 160rpm and a temperature of 130℃. Then add 2.63g of lithium chloride and stir for 11h at a temperature of 82℃. Then add 1.38g of triethylamine and 0.31g of intermediate and stir for 21h at room temperature. Then add methanol, filter, wash, and dry to obtain modified cellulose.

[0064] The method for preparing the coated photovoltaic glass is as follows: acrylic resin, modified nano titanium dioxide, fluorinated flame retardant, modified cellulose, and shellac are added to a mixing device and mixed at 38°C for 30 minutes at a rotation speed of 420 r / min to obtain a coating solution; the prepared coating solution is coated on one side of the glass substrate using a roller coating method, and then cured at low temperature to form a composite protective layer; after coating is completed, a cleaning process is performed to obtain the coated photovoltaic glass.

[0065] Comparative Example 1

[0066] A coated photovoltaic glass includes a glass substrate and a composite protective layer disposed on the glass substrate. The raw materials of the composite protective layer include, by weight, 60 parts of acrylic resin, 1 part of modified nano-titanium dioxide, 0.1 parts of intermediate 1, 0.2 parts of modified cellulose, and 2 parts of shellac.

[0067] The modified nano-titanium dioxide is prepared by mixing 40 mL of isopropanol and 5 mL of deionized water, then adding 1.4 g of γ-methacryloxypropyltrimethoxysilane coupling agent, stirring for 50 min, and then adding 12.6 g of nano-titanium dioxide. The mixture is reacted at 75 °C for 6 h and dried to obtain alkenylated nano-titanium dioxide.

[0068] The preparation method of the intermediate 1 is as follows:

[0069] S1. Under nitrogen atmosphere, 6.34 g of 4,4'-diaminodiphenyl sulfone and 0.02 g of triethylamine were added to a reactor containing 60 mL of acetonitrile. The mixture was heated to 45 °C and stirred for 0.5 h. Then, 7.54 g of phenylphosphine dichloride was added, and the mixture was reacted at 75 °C for 16 h. After the reaction was completed, the mixture was cooled to room temperature, eluted with methyl tert-butyl ether, and filtered to obtain intermediate 1.

[0070] The method for preparing the modified cellulose is as follows:

[0071] Step 1: Mix 4.3g of 2-(dodecyltrithiocarbonyl)-2-methylpropionic acid, 2.8g of oxaloyl chloride and 35mL of dichloromethane. Stir at 150rpm at room temperature and add 1.4mL of ethyl acetate. React for 7h and then rotary evaporate to obtain the intermediate.

[0072] Step 2: Mix 0.97g of nanocellulose and 52mL of N,N-dimethylacetamide, and stir for 2.5h at a stirring rate of 160rpm and a temperature of 130℃. Then add 2.63g of lithium chloride and stir for 11h at a temperature of 82℃. Then add 1.38g of triethylamine and 0.31g of intermediate and stir for 21h at room temperature. Then add methanol, filter, wash, and dry to obtain modified cellulose.

[0073] The method for preparing the coated photovoltaic glass is as follows: acrylic resin, modified nano titanium dioxide, intermediate 1, modified cellulose, and shellac are added to a mixing device and mixed at 38°C for 30 minutes at a rotation speed of 420 r / min to obtain a coating solution; the prepared coating solution is coated on the surface of one side of the glass substrate using a roller coating method, and then cured at low temperature to form a composite protective layer; after the coating is completed, a cleaning treatment is performed to obtain the coated photovoltaic glass.

[0074] Comparative Example 2

[0075] A coated photovoltaic glass includes a glass substrate and a composite protective layer disposed on the glass substrate. The raw materials of the composite protective layer include, by weight, 60 parts of acrylic resin, 1 part of modified nano-titanium dioxide, 0.1 parts of fluorine-containing flame retardant, 0.2 parts of nano-cellulose, and 2 parts of shellac.

[0076] The modified nano-titanium dioxide is prepared by mixing 40 mL of isopropanol and 5 mL of deionized water, then adding 1.4 g of γ-methacryloxypropyltrimethoxysilane coupling agent, stirring for 50 min, and then adding 12.6 g of nano-titanium dioxide. The mixture is reacted at 75 °C for 5 h and then dried to obtain alkenylated nano-titanium dioxide.

[0077] The preparation method of the fluorinated flame retardant is as follows:

[0078] S1. Under nitrogen atmosphere, 6.34 g of 4,4'-diaminodiphenyl sulfone and 0.02 g of triethylamine were added to a reactor containing 60 mL of acetonitrile. The mixture was heated to 45 °C and stirred for 0.5 h. Then, 7.54 g of phenylphosphine dichloride was added, and the mixture was reacted at 75 °C for 16 h. After the reaction was completed, the mixture was cooled to room temperature, eluted with methyl tert-butyl ether, and filtered to obtain intermediate 1.

[0079] S2. Add 8.54 g of perfluorooctanoic acid chloride and 4.3 g of intermediate 1 to 55 mL of N,N-dimethylformamide, stir and mix, then add 0.015 g of pyridine, react at 85 °C for 8 h, and after the reaction is completed, distill under reduced pressure and wash to obtain a fluorinated flame retardant.

[0080] The method for preparing the coated photovoltaic glass is as follows: acrylic resin, modified nano titanium dioxide, fluorinated flame retardant, cellulose, and shellac are added to a mixing device and mixed at 38°C for 30 minutes at a rotation speed of 420 r / min to obtain a coating solution; the prepared coating solution is coated on one side of the glass substrate using a roller coating method, and then cured at low temperature to form a composite protective layer; after coating is completed, a cleaning process is performed to obtain the coated photovoltaic glass.

[0081] Oxygen index testing was conducted according to GB / T 2406.2-2009;

[0082] Impact resistance test: steel ball impact test (227g steel ball dropped freely from a height of 1m). Post-impact condition: no cracks or damage (composite protective layer disperses stress); weathering test was conducted after 1000h of ultraviolet aging according to GB / T 1865-2009 "Artificial climate aging and artificial radiation exposure of paints and varnishes".

[0083] Table 1: Performance Tests.

[0084] project Oxygen index (%) Impact resistance Weather resistance Example 1 31.2 No cracks No yellowing, no peeling Example 2 32.6 No cracks No yellowing, no peeling Example 3 30.5 No cracks No yellowing, no peeling Example 4 31.6 No cracks No yellowing, no peeling Comparative Example 1 30.7 Slight cracks No yellowing, no peeling Comparative Example 2 25.9 Slight cracks No yellowing, no peeling

[0085] As shown in Table 1, the coated photovoltaic glass of the present invention in Examples 1-4 has better flame retardancy, impact resistance and weather resistance compared with Comparative Examples 1-2.

[0086] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0087] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coated photovoltaic glass, comprising a glass substrate and a composite protective layer disposed on the glass substrate, characterized in that: The raw materials of the composite protective layer include, by weight: 60-70 parts acrylic resin, 1-2 parts modified nano titanium dioxide, 0.1-0.3 parts fluorinated flame retardant, 0.2-0.5 parts modified cellulose, and 2-4 parts shellac. The preparation method of the fluorinated flame retardant is as follows: S1. Under inert gas, 4,4'-diaminodiphenyl sulfone and triethylamine are added to a reactor containing acetonitrile solvent, the temperature is raised to 40-45℃ and stirred for 0.4-0.5 h, then phenylphosphine dichloride is added, and the reaction is carried out at 70-75℃ for 12-16 h. After the reaction is completed, the mixture is cooled to room temperature, the solvent is eluted with methyl tert-butyl ether, and the mixture is filtered to obtain intermediate 1. S2. Add perfluorooctanoyl chloride and intermediate 1 to N,N-dimethylformamide solvent, stir and mix, continue to add pyridine catalyst, react at 75-85℃ for 6-8h, after which vacuum distillation and washing are performed to obtain fluorinated flame retardant; The method for preparing the modified cellulose is as follows: Step 1: Mix 2-(dodecyltrithiocarbonate)-2-methylpropionic acid, oxaloyl chloride and dichloromethane, stir at a stirring rate of 140-160 rpm at room temperature, add ethyl acetate, react for 6-9 h, and then rotary evaporate to obtain the intermediate. Step 2: Mix nanocellulose and N,N-dimethylacetamide at a stirring speed of 140-180 rpm and a temperature of 120-140℃ for 2-3 hours. Then add lithium chloride and stir at a temperature of 80-85℃ for 10-12 hours. Next, add triethylamine and an intermediate and stir at room temperature for 20-22 hours. Finally, add methanol, filter, wash, and dry to obtain modified cellulose.

2. The coated photovoltaic glass according to claim 1, characterized in that, The modified nano-titanium dioxide is prepared by mixing isopropanol and deionized water, then adding γ-methacryloyloxypropyltrimethoxysilane coupling agent, stirring for 50-60 min, continuing to add nano-titanium dioxide, reacting at 75-80℃ for 4-6 h, and drying to obtain alkenylated nano-titanium dioxide.

3. The coated photovoltaic glass according to claim 1, characterized in that, The ratio of acetonitrile, 4,4'-diaminodiphenyl sulfone, triethylamine, and phenylphosphine dichloride in S1 is 50-60 mL: 6.21-6.34 g: 0.01-0.02 g: 7.51-7.54 g.

4. The coated photovoltaic glass according to claim 1, characterized in that, The ratio of N,N-dimethylformamide, perfluorooctanoyl chloride, intermediate 1, and pyridine catalyst in S2 is 45-55 mL: 8.12-8.54 g: 4.1-4.3 g: 0.012-0.015 g.

5. The coated photovoltaic glass according to claim 1, characterized in that, In step one, the ratio of 2-(dodecyltrithiocarbonate)-2-methylpropionic acid, oxaloyl chloride, dichloromethane, and ethyl acetate is 4.2-4.4g: 2.5-2.9g: 30-40mL: 1.2-1.6mL.

6. The coated photovoltaic glass according to claim 1, characterized in that, In step two, the ratio of nanocellulose, N,N-dimethylacetamide, lithium chloride, triethylamine, and intermediate is 0.96-1.02g: 50-55mL: 2.5-2.65g: 1.35-1.42g: 0.28-0.33g.

7. A method for preparing coated photovoltaic glass as described in any one of claims 1-6, characterized in that, The method for preparing the coated photovoltaic glass is as follows: acrylic resin, modified nano titanium dioxide, fluorinated flame retardant, modified cellulose, and shellac are added to a mixing device and mixed at a speed of 400-450 r / min and at 35-40℃ for 25-35 min to obtain a coating solution; the prepared coating solution is coated on one side of the glass substrate using a roller coating method, and then cured at low temperature to form a composite protective layer; after coating is completed, a cleaning treatment is performed to obtain the coated photovoltaic glass.