Film coating process and application of photovoltaic glass

Abstract

The invention relates to the field of photovoltaic glass pretreatment, in particular to a photovoltaic glass coating process and application. By designing a pretreatment method before glass coating, a coating substrate with high surface cleanliness is obtained, and a neutral cleaning agent in pretreatment can effectively avoid corrosion of alkaline and acidic cleaning agents to glass; the plasma cleaning can generate oxidation reaction with the surface of a cleaned object through ionized oxygen and argon, so that residual organic matters in the glass substrate are effectively removed, the surface of the cleaned object is activated, and the combining capacity of the cleaned substrate and the coating medicinal material is improved.

Description

Technical Field

[0001] The present invention relates to the field of pretreatment of photovoltaic glass, and particularly to a coating process and application of photovoltaic glass. Background Art

[0002] Solar energy is one of the important clean energies. The low photoelectric conversion efficiency is the main reason restricting the development of solar power generation. Photovoltaic glass is a special glass designed for solar photovoltaic modules. It is mainly used to protect solar panels from environmental factors, while ensuring high light transmittance, so as to ensure that solar panels can absorb sunlight to the maximum extent and convert it into electrical energy.

[0003] Although photovoltaic glass with low iron content can improve light transmittance, when exposed to ultraviolet light and high temperature for a long time, the glass may turn yellow, reducing light transmittance and affecting the long-term performance of photovoltaic modules. Extreme temperature changes, strong winds, hail, etc. will also cause degradation of its durability under long-term use. In addition, in actual application scenarios, the surface of photovoltaic glass is easily contaminated, which will also reduce the absorption of light energy and thus affect photoelectric conversion.

[0004] Improving the stain resistance and abrasion resistance of photovoltaic glass is the key to improving the overall performance of photovoltaic modules and extending their service life. In the prior art, there are generally the following methods: (1) Coating a layer of superhydrophobic material such as fluorinated polymer and silane on the glass surface to make water droplets form spherical rolls and carry away dust and pollutants on the surface; (2) Using photocatalyst materials such as titanium dioxide (TiO2), which can decompose organic pollutants under ultraviolet light irradiation to keep the glass surface clean; (3) By coating a layer of hydrophilic material such as silicon-based and metal oxides, water droplets can quickly spread into a thin film to reduce the residue of water marks and stains; (4) Depositing a layer of hard material such as zirconia and alumina on the glass surface through chemical coating to enhance the abrasion resistance of the glass; (5) Improving the hardness and abrasion resistance of the glass through processes such as physical interlayer and surface polishing.

[0005] In actual applications, pretreatment before applying film or coating materials on photovoltaic glass is a very important step, which can significantly affect the film application effect and long-term performance. However, some defects may also occur during the pretreatment process. If these problems are not properly solved, it may lead to adverse consequences after film application, such as the hydrophobic structure of the hydrophobic film on photovoltaic glass being damaged to varying degrees within half a year and problems such as abrasion resistance.

[0006] Therefore, providing a pretreatment method and coating process before coating photovoltaic glass has great application prospects. Summary of the Invention

[0007] The first aspect of the present invention provides a coating process for photovoltaic glass, comprising the following steps:

[0008] S1. Pretreat and clean both sides of the photovoltaic glass, and dry it;

[0009] S2. Continue to perform plasma cleaning on the side of the photovoltaic glass to be coated;

[0010] S3. Coat an anti-reflection film on the side to be coated after the plasma cleaning in S2;

[0011] S4. Coat a hydrophobic film on the surface of the anti-reflection film, thus completing the coating process.

[0012] In some embodiments, the pretreatment cleaning comprises the following steps: successively clean with a cleaning agent, deionized water, ethanol, and isopropanol, and cool after drying.

[0013] In some embodiments, the cleaning agent is a mixture of a neutral cleaning agent and water, and the mass ratio of the two is (0.5 - 5):50.

[0014] In some embodiments, the neutral cleaning agent comprises fatty alcohol polyoxyethylene ether AEO-9, alkylphenol polyoxyethylene ether OP-10, sodium dodecylbenzenesulfonate, and sodium citrate.

[0015] Further, the mass ratio of fatty alcohol polyoxyethylene ether AEO-9, alkylphenol polyoxyethylene ether OP-10, sodium dodecylbenzenesulfonate, and sodium citrate is (2 - 5):(3 - 7):(2 - 4):(1 - 3).

[0016] The present invention selects a neutral cleaning agent to clean the photovoltaic glass, avoiding the corrosion of the photovoltaic glass by acidic and alkaline cleaning agents. The sodium silicate in the neutral cleaning agent formula can effectively protect the surface from corrosion;

[0017] By compounding and using fatty alcohol polyoxyethylene ether AEO-9, alkylphenol polyoxyethylene ether OP-10, sodium dodecylbenzenesulfonate, and sodium citrate as the compounded neutral cleaning agent, the hydrophobic chain adsorbs grease, the hydrophilic chain (polyoxyethylene group) combines with water to form micelles to wrap the oil stain, reduce the interfacial tension, enhance the permeability, and the non-ionic property does not damage the charge balance on the glass surface, avoiding coating defects caused by ion residues.

[0018] In some embodiments, the plasma cleaning is performed using a plasma cleaner, and the cleaning gas of the plasma cleaner is a mixture of argon and oxygen, and the volume ratio of the argon to the oxygen is (2 - 5):1.

[0019] In some embodiments, the cleaning conditions of the plasma cleaner are as follows: the vacuum pumping time is 10 - 15 s, the cleaning vacuum is 8 - 12 Pa, the cleaning power is 300 - 600 w, the cleaning time is 2 - 5 s, and the vacuum breaking time is 2 - 3 s.

[0020] In the present invention, plasma cleaning is performed on the photovoltaic glass. The ionized mixed gas acts on the surface of the object to be cleaned. Oxygen ions can oxidize trace amounts of organic matter on the surface to play a cleaning role, and argon ions activate the surface to improve the bonding ability between the surface and the coating material.

[0021] In some embodiments, an anti-reflection film is deposited using a coating machine. The vacuum degree of the coating machine is 0.01 - 0.03 Pa, the baking temperature is 300 - 350 °C, the baking time is 8 - 15 min, the rotation speed of the umbrella is 40 - 80 r / min, and the coating rate is 2 - 4.5 Å / sec.

[0022] In some embodiments, the raw materials of the anti-reflection film are silicon dioxide and niobium pentoxide.

[0023] In the present invention, the structure of the anti-reflection film and the types of coating materials are optimized. The coating structure is selected as an alternating structure of silicon dioxide and niobium pentoxide; the anti-reflection film layer can be 5 - 9 layers, which improves the repeatability and consistency during the coating process; the selection of silicon dioxide on the outermost layer is to match the perfluoropolyether silane modified hydrophobic material selected.

[0024] In some embodiments, the raw material of the hydrophobic film is a perfluoropolyether siloxane modified material.

[0025] In the present invention, the coating method of the hydrophobic film uses magnetron sputtering: the temperature of magnetron sputtering is lower than that of evaporation coating. During the coating process, it will not damage the structure of the perfluoropolyether silane modified hydrophobic material, and the magnetron sputtering method can improve the density of the hydrophobic film layer, and improve the friction resistance and hydrophobic properties of the film layer.

[0026] The second aspect of the present invention provides an application of the above coating process in the preparation of photovoltaic glass.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. By designing a pretreatment method before glass coating, the present invention obtains a coating substrate with high surface cleanliness. The neutral cleaning agent in the pretreatment can effectively avoid the corrosion of the glass by alkaline and acidic cleaning agents; plasma cleaning can react with the surface of the object to be cleaned through ionized oxygen and argon to effectively remove residual organic matter in the glass substrate, activate the surface of the object to be cleaned, and improve the bonding ability between the cleaned substrate and the coating materials.

[0029] 2. The present invention solves the problem of poor coating caused by water vapor in the antireflection film layer. By continuously heating the substrate to be coated during the deposition of the antireflection film, the water vapor in the substrate to be coated is evaporated, thereby improving the repeatability and consistency of the coating.

[0030] 3. The present invention solves the matching problem with hydrophobic medicinal materials by designing an alternating structure of the antireflection film and selecting the type of the antireflection film.

[0031] 4. The present invention solves the problem of weak bonding with hydrophobicity by increasing the thickness of the last layer of silica in the antireflection film. Description of the Drawings

[0032] Figure 1 It is a schematic structural diagram of a photovoltaic glass obtained by the coating process of the present invention.

[0033] Figures 2 - 3 It is a data graph of the reflectivity after coating.

[0034] In the figure, ① is the photovoltaic glass, ② is the antireflection film layer, and ③ is the hydrophobic film layer. Detailed Embodiments

[0035] Next, the technical solutions in the embodiments of the present invention will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0036] Embodiment 1

[0037] This embodiment provides a coating process for photovoltaic glass, including the following steps:

[0038] S1. Ultrasonically clean both sides of the photovoltaic glass successively with a cleaning agent (ultrasonic frequency 35 kHz, time 2 min), deionized water (ultrasonic frequency 35 kHz, time 2 min), ethanol (ultrasonic frequency 35 kHz, time 2 min), and isopropanol (ultrasonic frequency 35 kHz, time 2 min), bake at 75 °C for 5 min, and take out the photovoltaic glass to cool to room temperature under an ion blower.

[0039] The cleaning agent is a mixture of a neutral cleaning agent and water, and the mass ratio of the two is 1:50. The neutral cleaning agent is a mixture of fatty alcohol polyoxyethylene ether AEO-9, alkylphenol polyoxyethylene ether OP-10, sodium dodecylbenzenesulfonate, and sodium citrate with a mass ratio of 3:5:3:2.

[0040] S2. Continue to perform plasma cleaning on the side of the photovoltaic glass to be coated using a plasma cleaner. The cleaning conditions of the plasma cleaner are as follows: evacuation time is 11 s, cleaning vacuum is 10 Pa, cleaning power is 400 w, cleaning time is 3 s, vacuum breaking time is 2.5 s. The cleaning gas of the plasma cleaner is a mixture of argon and oxygen with a volume ratio of 3:1.

[0041] S3. Use a coating machine to coat an antireflection film on the side to be coated after plasma cleaning in S2. The vacuum degree of the coating machine is 0.02 Pa, the baking temperature is 330 °C, the baking time is 10 min, the rotation speed of the umbrella is 60 r / min, and the coating rate is 3 Å / sec;

[0042] The antireflection film has a total of 5 layers. The first layer is silicon dioxide (thickness 10 nm), the second layer is niobium pentoxide (thickness 6 nm), the third layer is silicon dioxide (thickness 12 nm), the fourth layer is niobium pentoxide (thickness 5 nm), and the fifth layer is silicon dioxide (thickness 10 nm);

[0043] Among them, the crystal purity of silicon dioxide is >99.99%, and the crystal purity of niobium pentoxide is >99.99%;

[0044] S4. Use a coating machine to coat a hydrophobic film on the surface of the antireflection film to obtain the ③ hydrophobic film layer in Figure 1 . The vacuum degree of coating is 0.03 Pa, the temperature is 120 °C, and the coating rate is 3 Å / sec, thus completing the coating process.

[0045] The hydrophobic film is a perfluoropolyether siloxane modifier with a purity >99.99%.

[0046] Example 2

[0047] This example provides a coating process for photovoltaic glass, including the following steps:

[0048] S1. Ultrasonically clean both sides of the photovoltaic glass in turn using a cleaning agent (ultrasonic frequency 40 kHz, time 1 min), deionized water (ultrasonic frequency 40 kHz, time 2 min), ethanol (ultrasonic frequency 40 kHz, time 2 min), and isopropanol (ultrasonic frequency 40 kHz, time 2 min), bake at 75 °C for 5 min, and take out the photovoltaic glass to cool to room temperature under an ion blower;

[0049] The cleaning agent is a mixture of a neutral cleaning agent and water with a mass ratio of 1:50. The neutral cleaning agent is a mixture of fatty alcohol polyoxyethylene ether AEO-9, alkylphenol polyoxyethylene ether OP-10, sodium dodecylbenzenesulfonate, and sodium citrate with a mass ratio of 2:3:2:1.

[0050] S2. Continue to perform plasma cleaning on the side of the photovoltaic glass to be coated using a plasma cleaner. The cleaning conditions of the plasma cleaner are as follows: evacuation time is 10 s, cleaning vacuum is 8 Pa, cleaning power is 300 w, cleaning time is 3 s, vacuum breaking time is 2.5 s. The cleaning gas of the plasma cleaner is a mixture of argon and oxygen with a volume ratio of 4:1.

[0051] S3. Use a coating machine to coat an anti-reflection film on the side to be coated after plasma cleaning in S2. The vacuum degree of the coating machine is 0.02 Pa, the baking temperature is 330 °C, the baking time is 10 min, the rotation speed of the umbrella is 60 r / min, and the coating rate is 3 Å / sec;

[0052] The anti-reflection film has a total of 5 layers. The first layer is silicon dioxide (thickness 10 nm), the second layer is niobium pentoxide (thickness 6 nm), the third layer is silicon dioxide (thickness 12 nm), the fourth layer is niobium pentoxide (thickness 5 nm), and the fifth layer is silicon dioxide (thickness 10 nm);

[0053] Among them, the crystal purity of silicon dioxide is >99.99%, and the crystal purity of niobium pentoxide is >99.99%;

[0054] S4. Use a coating machine to coat a hydrophobic film on the surface of the anti-reflection film to obtain the Figure 1 ③ hydrophobic film layer in. The vacuum degree of coating is 0.03 Pa, the temperature is 120 °C, and the coating rate is 3 Å / sec, thus completing the coating process.

[0055] The hydrophobic film is a perfluoropolyether siloxane modifier with a purity >99.99%.

[0056] Example 3

[0057] This example provides a coating process for photovoltaic glass, including the following steps:

[0058] S1. Ultrasonically clean both sides of the photovoltaic glass in turn using a cleaning agent (ultrasonic frequency 45 kHz, time 2 min), deionized water (ultrasonic frequency 45 kHz, time 2 min), ethanol (ultrasonic frequency 45 kHz, time 2 min), and isopropanol (ultrasonic frequency 45 kHz, time 2 min), bake at 75 °C for 5 min, and take out the photovoltaic glass to cool to room temperature under an ion blower;

[0059] The cleaning agent is a mixture of a neutral cleaning agent and water with a mass ratio of 1:50. The neutral cleaning agent is a mixture of fatty alcohol polyoxyethylene ether AEO-9, alkylphenol polyoxyethylene ether OP-10, sodium dodecylbenzenesulfonate, and sodium citrate with a mass ratio of 5:7:4:2.

[0060] S2. Continue to perform plasma cleaning on the side of the photovoltaic glass to be coated using a plasma cleaner. The cleaning conditions of the plasma cleaner are as follows: evacuation time is 15 s, cleaning vacuum is 12 Pa, cleaning power is 600 w, cleaning time is 3 s, vacuum break time is 2.5 s. The cleaning gas of the plasma cleaner is a mixture of argon and oxygen with a volume ratio of 5:1.

[0061] S3. Use a coating machine to coat an anti-reflection film on the side to be coated after the plasma cleaning in S2. The vacuum degree of the coating machine is 0.02 Pa, the baking temperature is 330 °C, the baking time is 10 min, the rotation speed of the umbrella is 60 r / min, and the coating rate is 3 Å / sec;

[0062] The anti-reflection film has a total of 5 layers. The first layer is silicon dioxide (thickness is 10 nm), the second layer is niobium pentoxide (thickness is 6 nm), the third layer is silicon dioxide (thickness is 12 nm), the fourth layer is niobium pentoxide (thickness is 5 nm), and the fifth layer is silicon dioxide (thickness is 10 nm);

[0063] Among them, the purity of silicon dioxide crystal is >99.99%, and the purity of niobium pentoxide crystal is >99.99%;

[0064] S4. Use a coating machine to coat a hydrophobic film on the surface of the anti-reflection film to obtain the ③ hydrophobic film layer in Figure 1 . The vacuum degree of the coating is 0.03 Pa, the temperature is 120 °C, and the coating rate is 3 Å / sec, thus completing the coating process.

[0065] The hydrophobic film is a perfluoropolyether siloxane modifier with a purity >99.99%.

[0066] Performance testing

[0067] Perform the following tests on the coated photovoltaic glass prepared in the above examples and comparative examples.

[0068] Reflectivity detection after coating: Use the detection instrument olympus-RU-W spectrometer. The experimental results are shown in Figures 1 - 2 .

[0069] Contact angle detection: Use a contact angle detector. The experimental results are shown in Table 1-3.

[0070] Table 1 Contact angle data

[0071] Sample number Contact angle of water drop / ° Example 1 120 Example 2 122 Example 3 123

[0072] Table 2 Contact angle data after UV aging

[0073] Sample number Contact angle of water drop after 500 h UV / ° Contact angle of water drop after 1000 h UV / ° Example 1 119 120 Example 2 120 121 Example 3 122 122

[0074] Table 3 Contact angle after 1000 times of friction

[0075] Sample number Contact angle of water drop before test / ° Contact angle of water drop after 1000 times of friction / ° Example 1 121 120 Example 2 122 122 Example 3 124 123

[0076] The above are the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A photovoltaic glass coating process, characterized in that: The steps include: S1. Pre-treat, clean and dry both sides of the photovoltaic glass; S2. Continue to perform plasma cleaning on the side of the photovoltaic glass to be coated; S3. coating the side to be coated with an anti-reflection film after plasma cleaning in S2; S4. A hydrophobic film is coated on the surface of the anti-reflection film, thus completing the coating process.

2. The coating process according to claim 1, characterized in that: The pre-treatment cleaning comprises the following steps: Use detergent, deionized water, ethanol, and isopropanol to clean in sequence, dry and cool.

3. The coating process according to claim 2, characterized in that: The cleaning agent is a mixture of a neutral cleaning agent and water, with a mass ratio of (0.5-5):

50.

4. The coating process according to claim 3, characterized in that: The neutral cleaning agent includes fatty alcohol polyoxyethylene ether AEO-9, alkylphenol polyoxyethylene ether OP-10, sodium dodecylbenzene sulfonate and sodium citrate.

5. The coating process according to claim 1, characterized in that: The plasma cleaning is performed by using a plasma cleaning machine, the cleaning gas of the plasma cleaning machine is a mixture of argon and oxygen, and the volume ratio of the argon and oxygen is (2-5):

1.

6. The coating process according to claim 5, characterized in that: The cleaning conditions of the plasma cleaning machine are: vacuuming time 10-15s, cleaning vacuum, 8-12Pa, cleaning power 300-600w, cleaning time 2-5s, and vacuum breaking time 2-3s.

7. The coating process according to claim 6, characterized in that: The anti-reflection film is coated by a coating machine, wherein the vacuum degree of the coating machine is 0.01-0.03 Pa, the baking temperature is 300-350° C., the baking time is 8-15 min, the umbrella rotation speed is 40-80 r / min, and the coating rate is 2-4.5 A / sec.

8. The coating process according to claim 7, characterized in that: The raw materials of the anti-reflection film are silicon dioxide and niobium pentoxide.

9. The coating process according to claim 8, characterized in that: The raw material of the hydrophobic film is a modified perfluoropolyether siloxane.

10. Use of the coating process according to any one of claims 1 to 9 in the preparation of photovoltaic glass.

Images