Marine photovoltaic anti-reflective coating and preparation method thereof

Abstract

The invention relates to a photovoltaic anti-reflective coating for offshore and a preparation method thereof, and belongs to the technical field of optical coatings. The coating comprises, by weight, 30-35 parts of ethyl orthosilicate, 8-14 parts of alkyl trimethoxysilane, 15-20 parts of alkyl diethoxysilane, 12-18 parts of anti-reflective aid, 10-15 parts of nano silicon dioxide, 1-1.3 parts of leveling agent, 10-15 parts of cosolvent, and 22-28 parts of deionized water; the anti-reflective aid is substituted by methyl vinyl dichlorosilane and tetrafluorobutanediol to form a fluorine-containing chain compound, i.e., an intermediate, and then by a double-bond click reaction of γ-mercaptopropyl triethoxysilane and a side chain of an intermediate molecule, an ethoxysilane structure modification is introduced into the side chain of the intermediate molecule, i.e., an anti-reflective aid is obtained, and the anti-reflective aid interacts with the nano silicon dioxide to reduce the reflectivity of the coating.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical coatings, and in particular, relates to an offshore photovoltaic anti-reflective coating and a preparation method thereof. Background Art

[0002] Solar energy has become an ideal clean energy source to replace fossil fuels due to its unique advantages such as no need for long-distance transmission, no noise, and no pollution. Photovoltaic power generation is a way of using solar energy with high utilization rate and development prospects. Among them, offshore photovoltaic power generation technology, as an important part of solar power generation, has great development potential.

[0003] At present, in the photovoltaic market, the more mature solar power generation devices are silicon-based solar cells and thin-film solar cells. Although the photoelectric conversion efficiency of their components has achieved rapid development in recent years, it is still around 20%. Improving the photoelectric conversion efficiency of light-absorbing materials in solar cell components is not only costly, but also has technical bottlenecks that are difficult to break through. Therefore, improving the transmittance of other materials in the component is currently a common method to increase the power generation of photovoltaic components. Preparing an anti-reflection layer on the photovoltaic cover glass can significantly reduce the reflectivity and increase the transmittance, thereby increasing the absorption of solar energy by the silicon-based absorption layer. The anti-reflection layer is divided into single-layer film and multi-layer film. The main materials of the single-layer film are SiO2, ZnS and TiO2, etc. It is difficult to achieve an ideal anti-reflection effect in a wide range, and the multi-layer anti-reflection film will increase the loss of materials and funds and the complexity of the coating process, and the anti-reflection and anti-transmittance gain of light is not high. Summary of the invention

[0004] In order to solve the technical problems mentioned in the background technology, the purpose of the present invention is to provide a marine photovoltaic anti-reflective coating and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A marine photovoltaic anti-reflective coating, comprising, by weight: 30-35 parts of ethyl orthosilicate, 8-14 parts of alkyltrimethoxysilane, 15-20 parts of alkyldiethoxysilane, 12-18 parts of anti-reflective additive, 10-15 parts of nano-silicon dioxide, 1-1.3 parts of leveling agent, 10-15 parts of cosolvent, and 22-28 parts of deionized water;

[0007] A method for preparing an offshore photovoltaic anti-reflective coating comprises the following steps:

[0008] Step S1: ultrasonically disperse the anti-reflection agent, nano-silica, co-solvent and deionized water, adjust the pH of the dispersion to 4-5 with formic acid, and stir at room temperature for 1.5-2.5 hours to obtain a pre-hydrolyzed solution;

[0009] Step S2: The pre-hydrolyzed liquid is heated to 60-75°C, ethyl orthosilicate and alkyl diethoxysilane are added, stirred and reacted for 2-3 hours, and then alkyl trimethoxysilane is added to continue the reaction for 5-7 hours. After cooling to room temperature, a leveling agent is added, mixed and aged for 3 days to obtain an offshore photovoltaic anti-reflection coating.

[0010] Preferably, the alkyltrimethoxysilane is one or both of methyltrimethoxysilane and propyltrimethoxysilane.

[0011] Preferably, the alkyldiethoxysilane is dimethyldiethoxysilane.

[0012] Preferably, the average particle size of nano-silicon dioxide is not higher than 20 nm.

[0013] Preferably, the leveling agent is selected from silicone leveling agents.

[0014] Preferably, the co-solvent is prepared by compounding isopropanol and ethanol.

[0015] The anti-reflection auxiliary agent is prepared by the following method:

[0016] Step A1: premix tetrafluorobutanediol and anhydrous dimethylacetamide, introduce dry nitrogen protection, heat to 80-90°C, stir at 90-120 rpm, slowly add methylvinyldichlorosilane, react for 3-4 hours, then add ethylene glycol to mix and quench, add water to evaporate under reduced pressure, wash the evaporated substrate with water, separate the liquids and vacuum dry to obtain an intermediate;

[0017] Furthermore, the dosage ratio of tetrafluorobutanediol, methylvinyldichlorosilane, ethylene glycol and anhydrous dimethylacetamide is 10mmol:11-13mmol:5-8mmol:25-35mL, and methylvinyldichlorosilane is substituted with tetrafluorobutanediol to form a fluorine-containing chain compound; the chemical formula of the intermediate is as follows:

[0018] ;

[0019] Among them, n=4-10;

[0020] Step A2: The intermediate, γ-mercaptopropyltriethoxysilane, dimethylphenylphosphine and anhydrous acetone were mixed, and dry nitrogen was introduced for protection. The temperature was raised to 50-60°C, and stirring was applied at 120-180 rpm and 300-400 W / m 2 UV irradiation, reflux reaction for 6-8h, after the reaction is completed, acetone is removed by rotary evaporation to obtain an anti-reflection auxiliary agent;

[0021] Furthermore, the dosage ratio of the intermediate, γ-mercaptopropyltriethoxysilane, dimethylphenylphosphine and anhydrous acetone is 10g:4.5-5.5g:40-55mg:60-70mL. Under ultraviolet irradiation, the double bond click reaction between γ-mercaptopropyltriethoxysilane and the side chain of the intermediate molecule is initiated, and the chemical formula of the anti-reflection additive modified by introducing ethoxysilane structure into the side chain of the intermediate molecule is as follows:

[0022] ;

[0023] Where n=4-10, Indicates a connection key.

[0024] Beneficial effects of the present invention:

[0025] The invention discloses a silica sol type anti-reflection coating, which uses traditional tetraethyl orthosilicate and silane compounds as main film-forming materials, and reduces the reflectivity of the coating by introducing an independently developed anti-reflection aid and interacting with nano silicon dioxide; the anti-reflection aid is substituted by methylvinyldichlorosilane and tetrafluorobutanediol to form a fluorine-containing chain compound, i.e., an intermediate, and then by a double-bond click reaction between γ-mercaptopropyltriethoxysilane and a side chain of the intermediate molecule, an ethoxysilane structure is introduced into the side chain of the intermediate molecule for modification, so as to obtain the anti-reflection aid; in the process of preparing the coating, the ethoxy structure of the side chain of the anti-reflection aid is preferentially hydrolyzed and coupled with nano silicon dioxide, so as to form a double-layer composite with the anti-reflection aid as a chain template and silicon dioxide particles attached thereto. When light waves pass through these layered interfaces, they are more likely to interfere destructively, thereby reducing overall reflection. In addition, the fluorine structure in the anti-reflection agent has a low refractive index, which can effectively reduce its refractive index after being compounded with silica particles, and can better match the refractive index of air, thereby reducing the reflection of light waves on the interface. In addition, the double-layer composite formed by the anti-reflection agent and silica particles has a high density and is deposited during the curing process. With the curing process, a gradual refractive index gradient is formed on the cured coating, reducing the reflection caused by the sudden change of the refractive index between layers. The fluorine structure enriched in the near-air layer gives the coating good tolerance, especially maintaining the anti-reflection stability of the coating under offshore photovoltaic conditions. DETAILED DESCRIPTION

[0026] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention. Unless otherwise specified in the embodiments, "parts" means "parts by weight."

[0027] Example 1, preparation of offshore photovoltaic anti-reflection coating, the specific implementation process is as follows:

[0028] (1) Preparation of anti-reflection additives

[0029] Step A1: pre-mix tetrafluorobutanediol and anhydrous dimethylacetamide, introduce dry nitrogen protection, heat to 90°C, stir at 120rpm, slowly add methylvinyldichlorosilane, react for 3h, then add ethylene glycol to mix and quench, wherein the amount ratio of tetrafluorobutanediol, methylvinyldichlorosilane, ethylene glycol and anhydrous dimethylacetamide is 10mmol:13mmol:8mmol:35mL, after the reaction is completed, add water and remove dimethylacetamide by rotary evaporation under reduced pressure, wash the rotary evaporation substrate with water, separate the liquid and vacuum dry to obtain an intermediate.

[0030] Step A2: Mix the intermediate, γ-mercaptopropyltriethoxysilane, dimethylphenylphosphine and anhydrous acetone, introduce dry nitrogen protection, heat to 60°C, stir at 180 rpm and 400 W / m 2 The reaction was carried out under ultraviolet irradiation and reflux reaction for 6 hours, wherein the usage ratio of the intermediate, γ-mercaptopropyltriethoxysilane, dimethylphenylphosphine and anhydrous acetone was 10 g:5.5 g:55 mg:70 mL. After the reaction, the acetone was removed by rotary evaporation to obtain an anti-reflection additive.

[0031] (2) Preparation of offshore photovoltaic anti-reflective coatings

[0032] The raw materials are measured by weight: 30 parts of tetraethyl orthosilicate; 14 parts of alkyltrimethoxysilane, propyltrimethoxysilane is used in the implementation process; 15 parts of alkyldiethoxysilane, dimethyldiethoxysilane is used in the implementation process; 14 parts of anti-reflection additive, which is self-made in this embodiment; 12 parts of nano-silica, Brofos-SiO2-07 type raw material is used in the implementation process, and the average particle size is 7nm; 1.1 parts of leveling agent, BLP-0415 type raw material is used in the implementation process; 10 parts of co-solvent, isopropanol and ethanol are compounded in a weight ratio of 2:1 in the implementation process; 24 parts of deionized water.

[0033] Step S1: ultrasonically disperse the anti-reflection agent, nano-silica, co-solvent and deionized water, adjust the pH of the dispersion to 4 with formic acid, stir at room temperature for 1.5 hours, and obtain a pre-hydrolyzed solution.

[0034] Step S2: The pre-hydrolyzed liquid is heated to 75°C, ethyl orthosilicate and dimethyldiethoxysilane are added, stirred and reacted for 2 hours, and methyltrimethoxysilane is added to continue the reaction for 5 hours. After cooling to room temperature, a leveling agent is added, mixed and aged for 3 days to obtain an offshore photovoltaic anti-reflection coating.

[0035] Example 2, preparation of offshore photovoltaic anti-reflection coating, the specific implementation process is as follows:

[0036] (1) Preparation of anti-reflection additives

[0037] Step A1: pre-mix tetrafluorobutanediol and anhydrous dimethylacetamide, introduce dry nitrogen protection, heat to 80°C, stir at 90rpm, slowly add methylvinyldichlorosilane, react for 4h, then add ethylene glycol to mix and quench, wherein the amount ratio of tetrafluorobutanediol, methylvinyldichlorosilane, ethylene glycol and anhydrous dimethylacetamide is 10mmol:11mmol:5mmol:25mL, add water and remove dimethylacetamide by rotary evaporation under reduced pressure after the reaction, wash the rotary evaporation substrate with water, separate the liquid and vacuum dry to obtain an intermediate.

[0038] Step A2: Mix the intermediate, γ-mercaptopropyltriethoxysilane, dimethylphenylphosphine and anhydrous acetone, introduce dry nitrogen protection, heat to 50°C, stir at 120 rpm and 300 W / m 2 The reaction was carried out under ultraviolet irradiation and reflux reaction for 8 hours, wherein the usage ratio of the intermediate, γ-mercaptopropyltriethoxysilane, dimethylphenylphosphine and anhydrous acetone was 10 g:4.5 g:40 mg:60 mL. After the reaction, the acetone was removed by rotary evaporation to obtain an anti-reflection additive.

[0039] (2) Preparation of offshore photovoltaic anti-reflective coatings

[0040] The raw materials are measured by weight: 35 parts of tetraethyl orthosilicate; 8 parts of alkyltrimethoxysilane, methyltrimethoxysilane is used in the implementation process; 20 parts of alkyldiethoxysilane, dimethyldiethoxysilane is used in the implementation process; 12 parts of anti-reflection additive, which is self-made in this embodiment; 10 parts of nano-silica, Brofos-SiO2-07 type raw material is used in the implementation process, and the average particle size is 7nm; 1 part of leveling agent, BLP-0415 type raw material is used in the implementation process; 15 parts of co-solvent, isopropanol and ethanol are compounded in a weight ratio of 2:1 in the implementation process; 22 parts of deionized water.

[0041] Step S1: ultrasonically disperse the anti-reflection agent, nano-silica, co-solvent and deionized water, adjust the pH of the dispersion to 5 with formic acid, stir at room temperature for 2.5 hours, and obtain a pre-hydrolyzed solution.

[0042] Step S2: The pre-hydrolyzed liquid is heated to 60°C, ethyl orthosilicate and dimethyldiethoxysilane are added, stirred and reacted for 3 hours, and methyltrimethoxysilane is added to continue the reaction for 7 hours. After cooling to room temperature, a leveling agent is added, mixed and aged for 3 days to obtain an offshore photovoltaic anti-reflection coating.

[0043] Example 3, preparation of offshore photovoltaic anti-reflection coating, the specific implementation process is as follows:

[0044] (1) Preparation of anti-reflection additives

[0045] Step A1: pre-mix tetrafluorobutanediol and anhydrous dimethylacetamide, introduce dry nitrogen protection, heat to 85°C, stir at 120 rpm, slowly add methylvinyldichlorosilane, react for 3.5 hours, then add ethylene glycol to mix and quench, wherein the amount ratio of tetrafluorobutanediol, methylvinyldichlorosilane, ethylene glycol and anhydrous dimethylacetamide is 10 mmol: 12 mmol: 6 mmol: 30 mL, add water and remove dimethylacetamide by rotary evaporation under reduced pressure after the reaction, wash the rotary evaporation substrate with water, separate the liquid and vacuum dry to obtain an intermediate.

[0046] Step A2: Mix the intermediate, γ-mercaptopropyltriethoxysilane, dimethylphenylphosphine and anhydrous acetone, introduce dry nitrogen for protection, heat to 55°C, stir at 120 rpm and 360 W / m 2 The reaction was carried out under ultraviolet irradiation and reflux reaction for 7 hours, wherein the usage ratio of the intermediate, γ-mercaptopropyltriethoxysilane, dimethylphenylphosphine and anhydrous acetone was 10 g:5 g:45 mg:65 mL. After the reaction, the acetone was removed by rotary evaporation to obtain an anti-reflection additive.

[0047] (2) Preparation of offshore photovoltaic anti-reflective coatings

[0048] The raw materials are measured by weight: 32 parts of tetraethyl orthosilicate; 11 parts of alkyltrimethoxysilane, propyltrimethoxysilane is used in the implementation process; 18 parts of alkyldiethoxysilane, dimethyldiethoxysilane is used in the implementation process; 16 parts of anti-reflection additive, which is self-made in this embodiment; 15 parts of nano-silica, Brofos-SiO2-07 type raw material is used in the implementation process, and the average particle size is 7nm; 1.3 parts of leveling agent, BLP-0415 type raw material is used in the implementation process; 12 parts of co-solvent, isopropanol and ethanol are compounded in a weight ratio of 2:1 in the implementation process; 28 parts of deionized water.

[0049] Step S1: ultrasonically disperse the anti-reflection agent, nano-silica, co-solvent and deionized water, adjust the pH of the dispersion to 4 with formic acid, and stir at room temperature for 1.8 hours to obtain a pre-hydrolyzed solution.

[0050] Step S2: The pre-hydrolyzed liquid is heated to 65°C, ethyl orthosilicate and dimethyldiethoxysilane are added, stirred and reacted for 2.5 hours, and methyltrimethoxysilane is added to continue the reaction for 6 hours. After cooling to room temperature, a leveling agent is added, mixed and aged for 3 days to obtain an offshore photovoltaic anti-reflection coating.

[0051] Example 4, preparation of offshore photovoltaic anti-reflection coating, the specific implementation process is as follows:

[0052] (1) Preparation of anti-reflection additives

[0053] Step A1: pre-mix tetrafluorobutanediol and anhydrous dimethylacetamide, introduce dry nitrogen protection, heat to 82°C, stir at 120 rpm, slowly add methylvinyldichlorosilane, react for 3.8 hours, then add ethylene glycol to mix and quench, wherein the amount ratio of tetrafluorobutanediol, methylvinyldichlorosilane, ethylene glycol and anhydrous dimethylacetamide is 10 mmol: 12 mmol: 7 mmol: 32 mL, add water and remove dimethylacetamide by rotary evaporation under reduced pressure after the reaction, wash the rotary evaporation substrate with water, separate the liquid and vacuum dry to obtain an intermediate.

[0054] Step A2: Mix the intermediate, γ-mercaptopropyltriethoxysilane, dimethylphenylphosphine and anhydrous acetone, introduce dry nitrogen protection, heat to 58°C, apply 180 rpm stirring and 320 W / m 2 The reaction was refluxed under ultraviolet irradiation for 7.5 hours, wherein the usage ratio of the intermediate, γ-mercaptopropyltriethoxysilane, dimethylphenylphosphine and anhydrous acetone was 10 g:4.8 g:50 mg:65 mL. After the reaction, the acetone was removed by rotary evaporation to obtain an anti-reflection additive.

[0055] (2) Preparation of offshore photovoltaic anti-reflective coatings

[0056] The raw materials are measured by weight: 33 parts of tetraethyl orthosilicate; 12 parts of alkyltrimethoxysilane, which is compounded by propyltrimethoxysilane and methyltrimethoxysilane in a weight ratio of 2:1 during the implementation process; 16 parts of alkyldiethoxysilane, which is dimethyldiethoxysilane during the implementation process; 18 parts of anti-reflection additive, which is self-made in this embodiment; 13 parts of nano-silicon dioxide, which is a Brofos-SiO2-07 raw material with an average particle size of 7nm during the implementation process; 1.2 parts of leveling agent, which is a BLP-0415 raw material during the implementation process; 12 parts of co-solvent, which is compounded by isopropanol and ethanol in a weight ratio of 2:1 during the implementation process; and 26 parts of deionized water.

[0057] Step S1: ultrasonically disperse the anti-reflection agent, nano-silica, co-solvent and deionized water, adjust the pH of the dispersion to 5 with formic acid, stir at room temperature for 2.2 hours, and obtain a pre-hydrolyzed solution.

[0058] Step S2: The pre-hydrolyzed liquid is heated to 70°C, ethyl orthosilicate and dimethyldiethoxysilane are added, stirred and reacted for 2.5 hours, and methyltrimethoxysilane is added to continue the reaction for 5.5 hours. After cooling to room temperature, a leveling agent is added, mixed and aged for 3 days to obtain an offshore photovoltaic anti-reflection coating.

[0059] Comparative Example

[0060] This comparative example is a commercially available BF-AR-2000 anti-reflective coating.

[0061] Take 3.2mm ultra-white photovoltaic rolled glass as the substrate, clean the surface with ethanol solution ultrasonic cleaning, and apply the anti-reflection coating obtained above, and control the coating amount to 8.5g / m 2 , let it stand for 1 hour to level, put it into the curing box with the coated surface facing down, and bake it at 80℃ for 5 hours to cure, and then make the test sample;

[0062] The light transmittance of the sample at a wavelength of 380-1100nm was tested using an air-floating tabletop spectral transmittance measurement system, recorded as the initial transmittance; the sample was immersed in a sodium chloride solution with a mass fraction of 10%, the temperature was controlled to be 60°C, the immersion time was 168h, and the surface was rinsed and dried after being taken out, and the transmittance was tested again and compared with the initial transmittance to calculate the transmittance retention rate, wherein the transmittance gain = the initial transmittance of the embodiment or comparative example - the initial transmittance of the original glass sheet, and the transmittance retention rate = (transmittance after sodium chloride immersion / initial transmittance) × 100%; the specific test data are shown in Table 1:

[0063] Table 1

[0064] ;

[0065] It can be seen from the test results in Table 1 that the anti-reflective coating of the embodiment has a transmittance gain of more than 3% after curing, has a higher anti-reflection and anti-reflection effect on photovoltaic glass, and has a stable anti-reflection and anti-reflection effect in a simulated high temperature and high salt environment at sea.

[0066] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0067] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A marine photovoltaic anti-reflective coating, characterized in that: The components include, by weight: 30-35 parts of ethyl orthosilicate, 8-14 parts of alkyltrimethoxysilane, 15-20 parts of alkyldiethoxysilane, 12-18 parts of anti-reflection additive, 10-15 parts of nano-silicon dioxide, 1-1.3 parts of leveling agent, 10-15 parts of cosolvent and 22-28 parts of deionized water; The chemical formula of the anti-reflection auxiliary agent is as follows: ； Where n=4-10, Indicates the connection key; The method for preparing the offshore photovoltaic anti-reflective coating comprises the following steps: Step S1: ultrasonically dispersing the anti-reflection agent, nano-silica, co-solvent and deionized water, adjusting the pH of the dispersion to 4-5 with formic acid, and stirring at room temperature to obtain a pre-hydrolyzed solution; Step S2: The pre-hydrolyzed liquid is heated to 60-75°C, and ethyl orthosilicate and alkyl diethoxysilane are first added to stir and react, and then alkyl trimethoxysilane is added to continue the reaction. After the reaction is completed, a leveling agent is added to mix and allowed to stand for aging to obtain an offshore photovoltaic anti-reflection coating.

2. The offshore photovoltaic anti-reflective coating according to claim 1, characterized in that: The preparation method of the anti-reflection auxiliary agent comprises the following steps: Step A1: premix tetrafluorobutanediol and anhydrous dimethylacetamide, introduce dry nitrogen for protection, heat to 80-90°C, slowly add methylvinyldichlorosilane and stir to react, then add ethylene glycol to mix and quench to obtain an intermediate, the chemical formula of the intermediate is as follows: ； Among them, n=4-10; Step A2: The intermediate, γ-mercaptopropyltriethoxysilane, dimethylphenylphosphine and anhydrous acetone are mixed, dry nitrogen is introduced for protection, the temperature is raised to 50-60° C., and reflux reaction is carried out under ultraviolet irradiation to obtain an anti-reflection auxiliary agent.

3. The offshore photovoltaic anti-reflective coating according to claim 2, characterized in that: The dosage ratio of tetrafluorobutanediol, methylvinyldichlorosilane, ethylene glycol and anhydrous dimethylacetamide is 10 mmol: (11-13) mmol: (5-8) mmol: (25-35) mL.

4. The offshore photovoltaic anti-reflective coating according to claim 3, characterized in that: The usage ratio of the intermediate, γ-mercaptopropyltriethoxysilane, dimethylphenylphosphine and anhydrous acetone is 10g: (4.5-5.5)g: (40-55)mg: (60-70)mL.

5. The offshore photovoltaic anti-reflective coating according to claim 1, characterized in that: The alkyltrimethoxysilane is one or both of methyltrimethoxysilane and propyltrimethoxysilane.

6. The offshore photovoltaic anti-reflective coating according to claim 1, characterized in that: The alkyldiethoxysilane is dimethyldiethoxysilane.

7. The offshore photovoltaic anti-reflective coating according to claim 1, characterized in that: The average particle size of nano-silicon dioxide is no more than 20 nm.

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