Low reflectance photovoltaic glass and method of making same

Abstract

The application relates to a low-reflectivity photovoltaic glass and a preparation method thereof. Sodium-calcium glass is cleaned by using a cleaning solution to obtain pretreated glass, the pretreated glass is etched by using ultrapure water and a sodium citrate solution in sequence to obtain etched glass, the etched glass is treated by using a surface treatment solution and is treated by ultraviolet light irradiation to obtain the low-reflectivity photovoltaic glass. When the etched glass is treated by using the surface treatment solution and is treated by ultraviolet light irradiation, modified additives and pentaerythritol triacrylate are crosslinked under the action of hydroxyl cyclohexyl phenone, and then a thin film is formed on the surface of the glass. The modified additives contain a cage-type silsesquioxane structure, a cage-type silicon oxygen skeleton of which is precisely nano-hybridized with external organic groups, can make the surface coating more uniform and stable, and can make the coating have a very good antireflection effect.

Description

Technical Field

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

[0002] In today's world, energy is no longer merely a convenience but an indispensable element for human survival. With continuous population growth and rapid modernization, there is an urgent need for more energy to ensure a high quality of life. Solar energy utilization includes three main forms: photoelectric conversion, photochemical conversion, and photothermal conversion. One of the important materials for solar cells is crystalline silicon. However, silicon doping leads to a high refractive index and increased surface reflection at the crystal interface, resulting in increased reflection losses and a significant reduction in the photoelectric conversion efficiency of solar cells. Furthermore, silicon solar cells are fragile and require photovoltaic glass for protection against external damage. Therefore, researching and designing photovoltaic glass with anti-reflection and anti-reflection properties is of significant research value for solving the problem of light reflection on the surface of solar cells and improving power generation efficiency. Summary of the Invention

[0003] The purpose of this invention is to provide a low-reflectivity photovoltaic glass and its preparation method, which solves the current problem of high reflectivity and low light energy utilization in photovoltaic glass.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A method for preparing low-reflectivity photovoltaic glass specifically includes the following steps:

[0006] Step A1: Mix the modified additive, pentaerythritol triacrylate, hydroxycyclohexyl benzophenone and xylene, and stir for 40-50 minutes at a speed of 600-800 r / min and a temperature of 20-25℃ to obtain the surface treatment solution.

[0007] Step A2: Mix deionized water, ethanol and acetone evenly to prepare a cleaning solution. Immerse the soda-lime glass in the cleaning solution and sonicate it for 30-40 minutes at a frequency of 30-50kHz and a temperature of 20-25℃ to obtain pretreated glass.

[0008] Step A3: Add the pretreated glass and ultrapure water to a polytetrafluoroethylene reactor. Etch at 160-165℃ for 20-25 hours. Remove the ultrapure water, add sodium citrate solution, and etch at 160-165℃ for 20-25 hours to obtain etched glass.

[0009] Step A4: Immerse the etched glass vertically in the surface treatment solution for 1-3 minutes. Lift the glass at a speed of 60-120 mm / min and heat-treat it at a temperature of 70-80℃ for 10-15 minutes. Then, irradiate it with ultraviolet light at 400-420 mJ / cm2 for 40-60 seconds to obtain low-reflectivity photovoltaic glass.

[0010] Furthermore, the ratio of the modified additive, pentaerythritol triacrylate, hydroxycyclohexyl benzophenone and xylene mentioned in step A1 is 0.05g:0.5g:0.01g:100mL.

[0011] Furthermore, the volume ratio of deionized water, ethanol, and acetone in step A2 is 1:1:1.

[0012] Furthermore, the concentration of the sodium citrate solution mentioned in step A3 is 0.04 mol / L.

[0013] Furthermore, the modified additive is prepared by the following steps:

[0014] Step B1: Mix aminopropyl heptaisobutylsilsesquioxane and tetrahydrofuran, purge with nitrogen, stir and add tetramethylammonium hydroxide at 120-150 r / min and 10-15℃, heat to 66-68℃ and react for 6-8 h to obtain an intermediate. Mix the intermediate with toluene evenly, stir and add aminopropyltriethoxysilane and triethylamine at 150-200 r / min and 110-115℃, reflux for 10-15 h to obtain diaminocage-type silsesquioxane.

[0015] Step B2: Trimethylsilyllithium and tetrahydrofuran are mixed and protected under nitrogen. Under conditions of 150-200 r / min and 0°C, trifluoropropylmethylcyclotrisiloxane is added while stirring. The temperature is raised to 25-30°C and the reaction is carried out for 20-24 h. Then, methyldichlorosilane is added and the reaction is continued for 1-1.5 h to obtain branched polysiloxane. The branched polysiloxane, caster catalyst and xylene are mixed and protected under nitrogen. Under conditions of 120-150 r / min and 0°C, 3,4-epoxy-1-butene is added while stirring. The temperature is raised to 15-20°C and the reaction is carried out for 10-15 h to obtain the modifier.

[0016] The reaction process of the modifier is as follows:

[0017]

[0018]

[0019]

[0020] Step B3: Mix diaminocage-type silsesquioxane, modifier, and xylene, and purge with nitrogen. React at 150-200 r / min and 30-40℃ for 1-1.5 h. Then raise the temperature to 80-90℃ and react for 2-3 h. Finally, raise the temperature to 110-120℃ and react for 1-1.5 h to obtain the pretreatment additive. Mix the pretreatment additive, acryloyl chloride, and xylene. Stir and add triethylamine at 200-300 r / min and 40-50℃ to obtain the modified additive.

[0021] Furthermore, in step B1, the molar ratio of aminopropylheptaisobutylsilsesquioxane to tetramethylammonium hydroxide is 1:1.2, the amount of intermediate and aminopropyltriethoxysilane is 1:2.5, and the amount of triethylamine is 0.01% of the mass of the intermediate.

[0022] Furthermore, in step B2, the molar ratio of Si-Cl bonds on lithium trimethylsilanolate, trifluoropropylmethylcyclotrisiloxane, and methyldichlorosilane is 1:5:1, the molar ratio of branched polysiloxane and 3,4-epoxy-1-butene is 1:1, and the amount of cassette catalyst is 0.01% of the mass of branched polysiloxane.

[0023] Furthermore, the molar ratio of the diaminocage-type silsesquioxane and the modifier in step B3 is 1:4.5, and the molar ratio of the pretreatment additive, acryloyl chloride and triethylamine is 1:4.1:4.5.

[0024] The beneficial effects of the present invention are as follows: The present invention discloses a low-reflectivity photovoltaic glass by cleaning soda-lime glass with a cleaning solution to obtain pretreated glass, etching the pretreated glass sequentially with ultrapure water and sodium citrate solution to obtain etched glass, and treating the etched glass with a surface treatment solution and irradiating it with ultraviolet light to obtain low-reflectivity photovoltaic glass. The surface treatment solution includes the following raw materials: modified additives, pentaerythritol triacrylate, hydroxycyclohexyl benzophenone and xylene.

[0025] The modified additive uses aminopropylheptaisobutylsilsesquioxane as a raw material and tetramethylammonium hydroxide as a catalyst to selectively break the Si-O-Si bond at the para position, generating three Si-OH bonds to obtain an intermediate. This intermediate is then subjected to a apex-cap reaction with aminopropyltriethoxysilane to obtain a diaminocage-type silsesquioxane. Trimethylsilyl alcohol is used as an initiator, and trifluoropropylmethylcyclotrisiloxane is used as a polymerization monomer to form a polysiloxane structure with a lithium silanolate end. The addition of methyldichlorosilane allows the Si-Cl bond on the methyldichlorosilane to react with the lithium silanolate, producing... A branched polysiloxane is obtained. The branched polysiloxane and 3,4-epoxy-1-butene are reacted under the action of a cassette catalyst, causing the Si-H bonds on the branched polysiloxane to react with the double bonds on the 3,4-epoxy-1-butene, thus obtaining a modifier. A diaminocage-type silsesquioxane is reacted with the modifier, causing the amino groups on the diaminocage-type silsesquioxane to react with the epoxy groups on the modifier, forming new hydroxyl groups, thus obtaining a pretreatment additive. The pretreatment additive is then reacted with acryloyl chloride, causing the hydroxyl groups on the pretreatment additive to react with the acyl chloride on the acryloyl chloride, thus obtaining a modified additive.

[0026] After surface treatment with etching glass, ultraviolet light irradiation causes cross-linking of the modified additive and pentaerythritol triacrylate under the action of hydroxycyclohexyl benzophenone, forming a thin film on the glass surface. The modified additive contains cage-like silsesquioxane structures, whose cage-like siloxane skeleton forms precise nano-hybrids with external organic groups, making the surface coating more uniform and stable, resulting in a good anti-reflection effect. The coating cross-linking network contains locally moving polysiloxane segments, which can reduce light scattering and make the film denser and smoother. It also contains fluoroalkane structures, and fluorine atoms reduce the electron density and polarizability of the material system through strong electronegativity, thereby obtaining an extremely low refractive index, and further enhancing the anti-reflection effect by utilizing the principle of optical interference. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 The image shows the infrared spectrum of the modifier prepared in Example 1 of this invention. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0030] Please see Figure 1 As shown in Example 1, a method for preparing low-reflectivity photovoltaic glass specifically includes the following steps:

[0031] Step A1: Mix the modified additive, pentaerythritol triacrylate, hydroxycyclohexyl benzophenone and xylene, and stir for 40 min at a speed of 600 r / min and a temperature of 20℃ to obtain the surface treatment solution.

[0032] Step A2: Mix deionized water, ethanol and acetone evenly to prepare a cleaning solution. Immerse the soda-lime glass in the cleaning solution and sonicate it for 30 minutes at a frequency of 30kHz and a temperature of 20℃ to obtain pretreated glass.

[0033] Step A3: Add the pretreated glass and ultrapure water to the polytetrafluoroethylene reactor. After etching at 160°C for 20 hours, remove the ultrapure water, add sodium citrate solution, and etch at 160°C for 20 hours to obtain etched glass.

[0034] Step A4: Immerse the etched glass vertically in the surface treatment solution for 1 minute. Lift the glass at a speed of 60 mm / min and heat-treat it at 70°C for 10 minutes. Then, irradiate it with 400 mJ / cm2 ultraviolet light for 40 seconds to obtain low-reflectivity photovoltaic glass.

[0035] The ratio of the modified additive, pentaerythritol triacrylate, hydroxycyclohexyl benzophenone and xylene used in step A1 is 0.05g:0.5g:0.01g:100mL.

[0036] The volume ratio of deionized water, ethanol and acetone in step A2 is 1:1:1.

[0037] The concentration of the sodium citrate solution mentioned in step A3 is 0.04 mol / L.

[0038] The modified additive is prepared by the following steps:

[0039] Step B1: Mix aminopropyl heptaisobutylsilsesquioxane and tetrahydrofuran, purge with nitrogen, stir and add tetramethylammonium hydroxide at 120 r / min and 10 °C, heat to 66 °C and react for 6 h to obtain an intermediate. Mix the intermediate with toluene evenly, stir and add aminopropyltriethoxysilane and triethylamine at 150 r / min and 110 °C, reflux for 10 h to obtain diaminocage-type silsesquioxane.

[0040] Step B2: Trimethylsilyllithium and tetrahydrofuran were mixed and protected under nitrogen. Under the conditions of 150 r / min and 0°C, trifluoropropylmethylcyclotrisiloxane was added while stirring. The mixture was heated to 25°C and reacted for 20 h. Then, methyldichlorosilane was added and the reaction was continued for 1 h to obtain branched polysiloxane. The branched polysiloxane, caster catalyst and xylene were mixed and protected under nitrogen. Under the conditions of 120 r / min and 0°C, 3,4-epoxy-1-butene was added while stirring. The mixture was heated to 15°C and reacted for 10 h to obtain the modifier.

[0041] Step B3: Mix diaminocage-type silsesquioxane, modifier, and xylene, purge with nitrogen, and react for 1 hour at 150 r / min and 30°C. Then, raise the temperature to 80°C and react for 2 hours. Finally, raise the temperature to 110°C and react for 1 hour to obtain the pretreatment additive. Mix the pretreatment additive, acryloyl chloride, and xylene, stir, and add triethylamine at 200 r / min and 40°C, and react for 1 hour to obtain the modified additive.

[0042] The molar ratio of aminopropylheptaisobutylsilsesquioxane and tetramethylammonium hydroxide in step B1 is 1:1.2, the amount of intermediate and aminopropyltriethoxysilane is 1:2.5, and the amount of triethylamine is 0.01% of the mass of the intermediate.

[0043] In step B2, the molar ratio of Si-Cl bonds on lithium trimethylsilanolate, trifluoropropylmethylcyclotrisiloxane, and methyldichlorosilane is 1:5:1, the molar ratio of branched polysiloxane and 3,4-epoxy-1-butene is 1:1, and the amount of cassette catalyst is 0.01% of the mass of branched polysiloxane.

[0044] The molar ratio of diaminocage-type silsesquioxane and modifier mentioned in step B3 is 1:4.5, and the molar ratio of pretreatment additive, acryloyl chloride and triethylamine is 1:4.1:4.5.

[0045] The FT-IR spectrum of the modifier is as follows: Figure 1 As shown, the beam is 2971m. -1The peak represents the stretching vibration of CH in -Si-CH3, at 2132 cm⁻¹. -1 The peak is the stretching vibration peak of -Si-H, at 1370 cm⁻¹. -1 The peak for the -CH2 vibration in trifluoropropyl is 1315 cm⁻¹. -1 The peak for the -CH2-CH2 vibration in the trifluoropropyl group is 1272 cm⁻¹. -1 and 768cm -1 The peak represents the stretching vibration of -Si-CH3, at 1205 cm⁻¹. -1 The characteristic peak of CF3 in trifluoropropyl is 1015 cm⁻¹. -1 The absorption peak is the Si-O-Si stretching vibration peak, 1060 cm⁻¹. -1 The absorption peaks are overlapping Si-O-Si and -Si-CH2-CH2-CF3, at 900 cm⁻¹. -1 The characteristic peak of C-CF3 is 820 cm⁻¹. -1 This is a characteristic absorption peak for epoxy groups.

[0046] Example 2, a method for preparing low-reflectivity photovoltaic glass, specifically includes the following steps:

[0047] Step A1: Mix the modified additive, pentaerythritol triacrylate, hydroxycyclohexyl benzophenone and xylene, and stir for 45 minutes at a speed of 600 r / min and a temperature of 25℃ to obtain the surface treatment solution.

[0048] Step A2: Mix deionized water, ethanol and acetone evenly to prepare a cleaning solution. Immerse the soda-lime glass in the cleaning solution and sonicate it for 35 minutes at a frequency of 40kHz and a temperature of 25℃ to obtain pretreated glass.

[0049] Step A3: Add the pretreated glass and ultrapure water to the polytetrafluoroethylene reactor. After etching at 160°C for 22 hours, remove the ultrapure water, add sodium citrate solution, and etch at 165°C for 22 hours to obtain etched glass.

[0050] Step A4: Immerse the etched glass vertically in the surface treatment solution for 1-3 minutes. Lift the glass at a speed of 120 mm / min and heat-treat it at 75°C for 10-15 minutes. Then, irradiate it with 410 mJ / cm2 ultraviolet light for 50 seconds to obtain low-reflectivity photovoltaic glass.

[0051] The ratio of the modified additive, pentaerythritol triacrylate, hydroxycyclohexyl benzophenone and xylene used in step A1 is 0.05g:0.5g:0.01g:100mL.

[0052] The volume ratio of deionized water, ethanol and acetone in step A2 is 1:1:1.

[0053] The concentration of the sodium citrate solution mentioned in step A3 is 0.04 mol / L.

[0054] The modified additive is prepared by the following steps:

[0055] Step B1: Mix aminopropyl heptaisobutylsilsesquioxane and tetrahydrofuran, purge with nitrogen, stir and add tetramethylammonium hydroxide at 120 r / min and 15 °C, heat to 66 °C and react for 7 h to obtain an intermediate. Mix the intermediate with toluene evenly, stir and add aminopropyltriethoxysilane and triethylamine at 150 r / min and 115 °C, reflux for 10 h to obtain diaminocage-type silsesquioxane.

[0056] Step B2: Trimethylsilyllithium and tetrahydrofuran were mixed and protected under nitrogen. Under the conditions of 150 r / min and 0°C, trifluoropropylmethylcyclotrisiloxane was added while stirring. The mixture was heated to 30°C and reacted for 22 h. Then, methyldichlorosilane was added and the reaction was continued for 1.3 h to obtain branched polysiloxane. The branched polysiloxane, caster catalyst and xylene were mixed and protected under nitrogen. Under the conditions of 120 r / min and 0°C, 3,4-epoxy-1-butene was added while stirring. The mixture was heated to 20°C and reacted for 13 h to obtain the modifier.

[0057] Step B3: Mix diaminocage-type silsesquioxane, modifier, and xylene, and purge with nitrogen. React at 150 r / min and 35°C for 1.3 h, then raise the temperature to 85°C and react for 3 h, then raise the temperature to 115°C and react for 1.5 h to obtain the pretreatment additive. Mix the pretreatment additive, acryloyl chloride, and xylene, and stir at 200 r / min and 45°C while adding triethylamine. React for 1.5 h to obtain the modified additive.

[0058] The molar ratio of aminopropylheptaisobutylsilsesquioxane and tetramethylammonium hydroxide in step B1 is 1:1.2, the amount of intermediate and aminopropyltriethoxysilane is 1:2.5, and the amount of triethylamine is 0.01% of the mass of the intermediate.

[0059] In step B2, the molar ratio of Si-Cl bonds on lithium trimethylsilanolate, trifluoropropylmethylcyclotrisiloxane, and methyldichlorosilane is 1:5:1, the molar ratio of branched polysiloxane and 3,4-epoxy-1-butene is 1:1, and the amount of cassette catalyst is 0.01% of the mass of branched polysiloxane.

[0060] The molar ratio of diaminocage-type silsesquioxane and modifier mentioned in step B3 is 1:4.5, and the molar ratio of pretreatment additive, acryloyl chloride and triethylamine is 1:4.1:4.5.

[0061] Example 3, a method for preparing low-reflectivity photovoltaic glass, specifically includes the following steps:

[0062] Step A1: Mix the modified additive, pentaerythritol triacrylate, hydroxycyclohexyl benzophenone and xylene, and stir for 50 min at a speed of 800 r / min and a temperature of 25℃ to obtain the surface treatment solution.

[0063] Step A2: Mix deionized water, ethanol and acetone evenly to prepare a cleaning solution. Immerse the soda-lime glass in the cleaning solution and sonicate it for 40 minutes at a frequency of 50 kHz and a temperature of 25 ℃ to obtain pretreated glass.

[0064] Step A3: Add the pretreated glass and ultrapure water to the polytetrafluoroethylene reactor. After etching at 165°C for 25 hours, remove the ultrapure water, add sodium citrate solution, and etch at 165°C for 25 hours to obtain etched glass.

[0065] Step A4: Immerse the etched glass vertically in the surface treatment solution for 3 minutes. Lift the glass at a speed of 120 mm / min and heat-treat it at 80°C for 15 minutes. Then, irradiate it with 420 mJ / cm2 ultraviolet light for 60 seconds to obtain low reflectivity photovoltaic glass.

[0066] The ratio of the modified additive, pentaerythritol triacrylate, hydroxycyclohexyl benzophenone and xylene used in step A1 is 0.05g:0.5g:0.01g:100mL.

[0067] The volume ratio of deionized water, ethanol and acetone in step A2 is 1:1:1.

[0068] The concentration of the sodium citrate solution mentioned in step A3 is 0.04 mol / L.

[0069] The modified additive is prepared by the following steps:

[0070] Step B1: Mix aminopropyl heptaisobutylsilsesquioxane and tetrahydrofuran, purge with nitrogen, stir and add tetramethylammonium hydroxide at 150 r / min and 15 °C, heat to 68 °C and react for 8 h to obtain an intermediate. Mix the intermediate with toluene evenly, stir and add aminopropyltriethoxysilane and triethylamine at 200 r / min and 115 °C, reflux for 15 h to obtain diaminocage-type silsesquioxane.

[0071] Step B2: Trimethylsilyllithium and tetrahydrofuran were mixed and protected under nitrogen. Under the conditions of 200 r / min and 0°C, trifluoropropylmethylcyclotrisiloxane was added while stirring. The mixture was heated to 30°C and reacted for 24 h. Then, methyldichlorosilane was added and the reaction was continued for 1.5 h to obtain branched polysiloxane. The branched polysiloxane, caster catalyst and xylene were mixed and protected under nitrogen. Under the conditions of 150 r / min and 0°C, 3,4-epoxy-1-butene was added while stirring. The mixture was heated to 20°C and reacted for 15 h to obtain the modifier.

[0072] Step B3: Mix diaminocage-type silsesquioxane, modifier, and xylene, purge with nitrogen, and react at 200 r / min and 40°C for 1.5 h. Then raise the temperature to 90°C and react for 3 h. Finally, raise the temperature to 120°C and react for 1.5 h to obtain the pretreated additive. Mix the pretreated additive, acryloyl chloride, and xylene, stir, and add triethylamine at 300 r / min and 50°C, and react for 2 h to obtain the modified additive.

[0073] The molar ratio of aminopropylheptaisobutylsilsesquioxane and tetramethylammonium hydroxide in step B1 is 1:1.2, the amount of intermediate and aminopropyltriethoxysilane is 1:2.5, and the amount of triethylamine is 0.01% of the mass of the intermediate.

[0074] In step B2, the molar ratio of Si-Cl bonds on lithium trimethylsilanolate, trifluoropropylmethylcyclotrisiloxane, and methyldichlorosilane is 1:5:1, the molar ratio of branched polysiloxane and 3,4-epoxy-1-butene is 1:1, and the amount of cassette catalyst is 0.01% of the mass of branched polysiloxane.

[0075] The molar ratio of diaminocage-type silsesquioxane and modifier mentioned in step B3 is 1:4.5, and the molar ratio of pretreatment additive, acryloyl chloride and triethylamine is 1:4.1:4.5.

[0076] Comparative Example 1: This comparative example uses butane oxide instead of the modifier as described in Example 1, but the other steps are the same.

[0077] Comparative Example 2: Compared with Example 1, this comparative example uses hexamethylcyclotrisiloxane instead of trifluoropropylmethylcyclotrisiloxane, and the other steps are the same.

[0078] Comparative Example 3: This comparative example uses octaisobutyl cage-type polysilsesquioxane instead of the modifying additives, while the other steps are the same as in Example 1.

[0079] The average transmittance of the photovoltaic glasses prepared in Examples 1-3 and Comparative Examples 1-3 was measured using a UV-Vis spectrophotometer in the wavelength range of 380-780nm. The test results are shown in Table 1 below.

[0080] Table 1

[0081]

[0082] As shown in Table 1, this application has a very good anti-reflection effect.

[0083] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0084] The above content is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the scope defined by the inventive concept, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing low-reflectivity photovoltaic glass, characterized in that: Specifically, the steps include the following: Step A1: Mix the modified additive, pentaerythritol triacrylate, hydroxycyclohexyl benzophenone and xylene, and stir for 40-50 minutes at a speed of 600-800 r / min and a temperature of 20-25℃ to obtain the surface treatment solution. Step A2: Mix deionized water, ethanol and acetone evenly to prepare a cleaning solution. Immerse the soda-lime glass in the cleaning solution and sonicate it for 30-40 minutes at a frequency of 30-50kHz and a temperature of 20-25℃ to obtain pretreated glass. Step A3: Add the pretreated glass and ultrapure water to a polytetrafluoroethylene reactor. Etch at 160-165℃ for 20-25 hours. Remove the ultrapure water, add sodium citrate solution, and etch at 160-165℃ for 20-25 hours to obtain etched glass. Step A4: Vertically immerse the etched glass in the surface treatment solution for 1-3 minutes. Then, lift the glass at a speed of 60-120 mm / min and heat-treat it at 70-80℃ for 10-15 minutes at 400-420 mJ / cm². 2 Low-reflectivity photovoltaic glass was produced by irradiating the glass with ultraviolet light for 40-60 seconds. The modified additive is prepared by the following steps: Step B1: Mix aminopropyl heptaisobutylsilsesquioxane and tetrahydrofuran, purge with nitrogen, stir and add tetramethylammonium hydroxide to react and obtain an intermediate. Mix the intermediate with toluene and stir, then add aminopropyltriethoxysilane and triethylamine and reflux to obtain diaminocage-type silsesquioxane. Step B2: Trimethylsilyllithium and tetrahydrofuran are mixed, nitrogen gas is introduced for protection, and trifluoropropylmethylcyclotrisiloxane is added while stirring. After reaction, methyldichlorosilane is added and the reaction continues to obtain branched polysiloxane. The branched polysiloxane, caster catalyst and xylene are mixed, nitrogen gas is introduced for protection, 3,4-epoxy-1-butene is added while stirring and the reaction is carried out to obtain the modifier. Step B3: Mix diaminocage-type silsesquioxane, modifier and xylene, purge with nitrogen and react to obtain pretreatment additive. Mix pretreatment additive, acryloyl chloride and xylene, stir and add triethylamine and react to obtain modified additive.

2. The method for preparing low-reflectivity photovoltaic glass according to claim 1, characterized in that: The ratio of the modified additive, pentaerythritol triacrylate, hydroxycyclohexyl benzophenone and xylene used in step A1 is 0.05g:0.5g:0.01g:100mL.

3. The method for preparing low-reflectivity photovoltaic glass according to claim 1, characterized in that: The volume ratio of deionized water, ethanol and acetone in step A2 is 1:1:

1.

4. The method for preparing low-reflectivity photovoltaic glass according to claim 1, characterized in that: The concentration of the sodium citrate solution mentioned in step A3 is 0.04 mol / L.

5. The method for preparing low-reflectivity photovoltaic glass according to claim 1, characterized in that: The molar ratio of aminopropylheptaisobutylsilsesquioxane and tetramethylammonium hydroxide in step B1 is 1:1.2, and the amounts of the intermediate and aminopropyltriethoxysilane are 1:2.

5.

6. The method for preparing low-reflectivity photovoltaic glass according to claim 1, characterized in that: The molar ratio of Si-Cl bonds on lithium trimethylsilanolate, trifluoropropylmethylcyclotrisiloxane and methyldichlorosilane in step B2 is 1:5:1, and the molar ratio of branched polysiloxane and 3,4-epoxy-1-butene is 1:

1.

7. The method for preparing low-reflectivity photovoltaic glass according to claim 1, characterized in that: The molar ratio of diaminocage-type silsesquioxane and modifier mentioned in step B3 is 1:4.5, and the molar ratio of pretreatment additive, acryloyl chloride and triethylamine is 1:4.1:4.

5.

8. A low-reflectivity photovoltaic glass, characterized in that: Prepared according to any one of the preparation methods described in claims 1-7.

Images