Anti-scratch coating liquid for photovoltaic module and production process of anti-scratch coating liquid

Abstract

The invention relates to the technical field of photovoltaic module coating liquid, and discloses photovoltaic module anti-scratch coating liquid and a production process thereof. The coating liquid prepared by the invention is mainly prepared by taking the water-based acrylic resin with good light transmission and strong adhesive power as a main raw material and adding the enhancer, the hydroxyl silicone oil and the solvent; wherein due to the introduction of the reinforcing agent, not only are the antireflection capability and the light transmittance of the coating liquid improved, but also the scratch resistance of the coating liquid after film formation is improved. Therefore, the coating liquid prepared by the invention has a good application prospect when being applied to photovoltaic modules, such as photovoltaic glass.

Description

Technical Field

[0001] The present invention relates to the technical field of coating liquids for photovoltaic modules, and particularly relates to an anti-scratch coating liquid for photovoltaic modules and its production process. Background Art

[0002] With the rapid development of photovoltaic technology and the popularization of double-sided power generation modules, the photovoltaic glass or transparent backplane in photovoltaic modules, as the core interface for light incidence, its surface performance directly determines the power generation efficiency and lifespan of the modules. Traditional photovoltaic module surfaces mostly use inorganic sol-gel coating layers and organic polymer coating layers as protective layers, but still face the following challenges, such as: the risk of mechanical damage, external forces such as sand, hail, and cleaning tools are likely to cause scratches on the surface of the coating layer, increasing light scattering and decreasing light transmittance.

[0003] The organic polymer coating layers mainly include acrylic, polyurethane, etc. Among them, waterborne acrylic resin has become the preferred matrix material for replacing solvent-based coatings due to its environmental friendliness (low VOC), excellent film-forming property, and strong weather resistance. However, there are still obvious deficiencies in the application of traditional waterborne acrylic coating layers in photovoltaic modules, such as: the contradiction between hardness and toughness, high crosslinking density can improve hardness, but brittleness increases, and microcracks are easily generated under dynamic loads, which leads to insufficient anti-scratch performance of the coating layer. Therefore, aiming at the above shortcomings, researchers need to develop a coating liquid with high light transmittance, anti-scratch performance, and excellent adhesion to meet the actual needs of photovoltaic modules. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides an anti-scratch coating liquid for photovoltaic modules and its production process.

[0005] The object of the present invention can be achieved by the following technical solutions:

[0006] An anti-scratch coating liquid for photovoltaic modules, comprising the following raw materials in parts by weight: 10 - 15 parts of waterborne acrylic resin, 4 - 7 parts of silica sol, 5 - 9 parts of reinforcing agent, 2 - 5 parts of hydroxy silicone oil, 35 - 55 parts of isopropanol, and 25 - 45 parts of water;

[0007] The reinforcing agent is prepared by the following steps:

[0008] Step A1: Mix zinc oxide and activated carbon, add water and stir evenly, dry at 200°C for 12 h, then place in a tube furnace, heat up to 900°C, introduce a mixed gas, collect and grind to obtain ZnO NW (zinc oxide nanowires);

[0009] Further, in step A1, the mass ratio of zinc oxide, activated carbon, and water is 1:1:5;

[0010] Further, in step A1, the mixed gas is argon and oxygen, and the gas volume ratio is 10:1;

[0011] Step A2: Ultrasonically disperse cetyltrimethylammonium bromide, ZnO NW, and water, add 2 mol / L sodium hydroxide solution, and heat to 70 °C for vigorous stirring for 5 - 10 min. Slowly add tetraethyl orthosilicate and silane coupling agent KH560 and stir for reaction for 30 - 50 min. Add ethanol and ammonium nitrate, and reflux at 60 °C for 2 - 3 h. Filter, wash, and dry to obtain ZnO NW@mSiO2 material (mesoporous silica-coated ZnO NW nanomaterial);

[0012] Further, in step A2, the dosage ratio of cetyltrimethylammonium bromide, ZnO NW, water, sodium hydroxide solution, tetraethyl orthosilicate, silane coupling agent KH560, ethanol, and ammonium nitrate is 0.5 - 1.5 g: 1 - 5 g: 50 mL: 10 mL: 0.2 - 0.4 mL: 0.1 - 0.2 mL: 100 mL: 0.5 - 1.2 g;

[0013] Step A3: Mix and stir ZnO NW@mSiO2 material and tetrabutylammonium bromide evenly in N,N-dimethylformamide, then add polyethylene glycol monomethyl ether (Mw = 350), and react at 90 °C under nitrogen for 4 - 6 h. Rotate evaporate, wash, and dry to obtain the enhancer;

[0014] Further, in step A3, the dosage ratio of ZnO NW@mSiO2 material, tetrabutylammonium bromide, N,N-dimethylformamide, and polyethylene glycol monomethyl ether is 5 - 10 g: 0.001 - 0.003 mol: 100 mL: 0.01 - 0.02 mol.

[0015] A production process of an anti-scratch coating solution for a photovoltaic module includes the following steps:

[0016] Weigh the raw materials by weight. Mix and stir evenly aqueous acrylic resin, silica sol, enhancer, hydroxy silicone oil, isopropyl alcohol, and water at 35 - 45 °C, and cool to room temperature to obtain the anti-scratch coating solution for the photovoltaic module.

[0017] The beneficial effects of the present invention:

[0018] The coating solution prepared by the present invention is mainly prepared from a waterborne acrylic resin with good light transmittance and strong adhesion as the main raw material, and adding a reinforcing agent, hydroxy silicone oil and a solvent; wherein, the reinforcing agent is prepared by using zinc oxide nanowires as a substrate, coating mesoporous silica on its surface, and grafting a polyether structure. The introduction of the reinforcing agent not only improves the antireflection ability and transmittance of the coating solution, but also improves the scratch resistance of the film formed by the coating solution. Therefore, applying the coating solution prepared by the present invention to photovoltaic modules, such as photovoltaic glass, has a good application prospect.

[0019] The reinforcing agent can be evenly dispersed in the coating solution, and the synergistic effect among ZnO NW, mesoporous silica and polyether segments improves the antireflection ability, light transmittance and scratch resistance of the coating solution; wherein, the presence of ZnO NW can significantly reduce the reflection loss of light on the surface of the photovoltaic module and improve the light transmittance; and the mesoporous silica coated on the surface of ZnO NW can utilize the porosity of the mesoporous structure to adjust the effective refractive index of the film layer of the coating solution, reduce the interface reflection, and improve the light transmittance of the film layer. At the same time, the mesoporous structure can also absorb external stress, reduce the scratches caused by stress on the film layer, and improve the scratch resistance of the film layer. In addition, a polyether structure is introduced on the surface of the mesoporous silica by a chemical grafting method in the reinforcing agent. The polyether molecular chain has excellent flexibility and low surface energy, and can form a "dynamic lubricating layer" on the surface of the film layer of the coating solution. When an external force scratches the film layer, the polyether structure can effectively reduce the surface friction coefficient through the sliding or deformation of the molecular chain, reduce the scratch depth and visibility, thereby improving the scratch resistance of the coating solution. Detailed implementation mode

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] Example 1: The reinforcing agent is prepared by the following steps:

[0022] Step A1: Mix 10 g of zinc oxide and 10 g of activated carbon, add 50 g of water and stir evenly, dry at 200 °C for 12 h, then place it in a tubular furnace, heat up to 900 °C, introduce a mixed gas, collect and grind to obtain ZnO NW. The mixed gas is argon and oxygen, and the gas volume ratio is 10:1;

[0023] Step A2: Ultrasonically disperse 0.5 g of cetyltrimethylammonium bromide, 1 g of ZnO NW and 50 mL of water, add 10 mL of 2 mol / L sodium hydroxide solution, and raise the temperature to 70 °C, stir vigorously for 5 min, slowly add 0.2 mL of tetraethyl orthosilicate and 0.1 mL of silane coupling agent KH560, stir and react for 30 min, add 100 mL of ethanol and 0.5 g of ammonium nitrate, and reflux and react at 60 °C for 2 h, filter, wash and dry to obtain the ZnO NW@mSiO2 material;

[0024] Step A3: Mix and stir 5 g of ZnO NW@mSiO2 material and 0.001 mol of tetrabutylammonium bromide evenly in 100 mL of N,N-dimethylformamide, then add 0.01 mol of methoxypolyethylene glycol (Mw = 350), and react at 90 °C under nitrogen for 4 h, rotary evaporate, wash and dry to obtain the enhancer.

[0025] Example 2: The enhancer is prepared by the following steps:

[0026] Step A1: Mix 10 g of zinc oxide and 10 g of activated carbon, add 50 g of water and stir evenly, dry at 200 °C for 12 h, then place it in a tube furnace, raise the temperature to 900 °C, introduce a mixed gas, collect and grind to obtain ZnO NW, the mixed gas is argon and oxygen, and the gas volume ratio is 10:1;

[0027] Step A2: Ultrasonically disperse 1 g of cetyltrimethylammonium bromide, 3 g of ZnO NW and 50 mL of water, add 10 mL of 2 mol / L sodium hydroxide solution, and raise the temperature to 70 °C, stir vigorously for 7 min, slowly add 0.3 mL of tetraethyl orthosilicate and 0.15 mL of silane coupling agent KH560, stir and react for 40 min, add 100 mL of ethanol and 0.9 g of ammonium nitrate, and reflux and react at 60 °C for 2.5 h, filter, wash and dry to obtain the ZnO NW@mSiO2 material;

[0028] Step A3: Mix and stir 7.5 g of ZnO NW@mSiO2 material and 0.002 mol of tetrabutylammonium bromide evenly in 100 mL of N,N-dimethylformamide, then add 0.015 mol of methoxypolyethylene glycol (Mw = 350), and react at 90 °C under nitrogen for 5 h, rotary evaporate, wash and dry to obtain the enhancer.

[0029] Example 3: The enhancer is prepared by the following steps:

[0030] Step A1: Mix 10 g of zinc oxide and 10 g of activated carbon, add 50 g of water, stir evenly, dry at 200 °C for 12 h, then place it in a tubular furnace, heat up to 900 °C, introduce a mixed gas, collect and grind to obtain ZnO NW. The mixed gas is argon and oxygen, and the gas volume ratio is 10:1;

[0031] Step A2: Ultrasonically disperse 1.5 g of cetyltrimethylammonium bromide, 5 g of ZnO NW and 50 mL of water, add 10 mL of 2 mol / L sodium hydroxide solution, and heat up to 70 °C, stir vigorously for 10 min. Slowly add 0.4 mL of tetraethyl orthosilicate and 0.2 mL of silane coupling agent KH560, stir and react for 50 min. Add 100 mL of ethanol and 1.2 g of ammonium nitrate, and reflux and react at 60 °C for 3 h. Filter, wash and dry to obtain the ZnO NW@mSiO2 material;

[0032] Step A3: Mix 10 g of ZnO NW@mSiO2 material and 0.003 mol of tetrabutylammonium bromide evenly in 100 mL of N,N-dimethylformamide, then add 0.02 mol of polyethylene glycol monomethyl ether (Mw = 350), and react at 90 °C under nitrogen for 6 h. Rotate and evaporate, wash and dry to obtain the enhancer.

[0033] Example 4: A production process of an anti-scratch coating solution for a photovoltaic module includes the following steps:

[0034] Weigh the raw materials by weight. Mix 10 parts of waterborne acrylic resin, 4 parts of silica sol, 5 parts of the enhancer prepared in Example 1, 2 parts of hydroxy silicone oil, 35 parts of isopropanol and 25 parts of water evenly at 35 °C, and cool to room temperature to obtain the anti-scratch coating solution for the photovoltaic module.

[0035] Example 5: A production process of an anti-scratch coating solution for a photovoltaic module includes the following steps:

[0036] Weigh the raw materials by weight. Mix 12 parts of waterborne acrylic resin, 6 parts of silica sol, 7 parts of the enhancer prepared in Example 2, 3 parts of hydroxy silicone oil, 45 parts of isopropanol and 35 parts of water evenly at 40 °C, and cool to room temperature to obtain the anti-scratch coating solution for the photovoltaic module.

[0037] Example 6: A production process of an anti-scratch coating solution for a photovoltaic module includes the following steps:

[0038] Weigh the raw materials by weight. Mix 15 parts of waterborne acrylic resin, 7 parts of silica sol, 9 parts of the enhancer prepared in Example 3, 5 parts of hydroxy silicone oil, 55 parts of isopropanol and 45 parts of water evenly at 45 °C, and cool to room temperature to obtain the anti-scratch coating solution for the photovoltaic module.

[0039] Comparative Example 1: This comparative example is a coating solution. The difference from Example 6 is that the zinc oxide nanowires prepared in Example 3 are used instead of the enhancer prepared in Example 3, and the rest are the same.

[0040] Comparative Example 2: This comparative example is a coating solution. The difference from Example 6 is that the ZnO NW@mSiO2 material prepared in Example 3 is used instead of the enhancer prepared in Example 3, and the rest are the same.

[0041] Comparative Example 3: This comparative example is a coating solution. The difference from Example 6 is that the enhancer prepared in Example 3 is not added, and the rest are the same.

[0042] The coating solutions prepared in Examples 4 - 6 and Comparative Examples 1 - 3 were respectively and uniformly coated on the surface of photovoltaic glass, and vacuum dried at 140 °C, with a coating amount of 50 g / m 2 , and then the prepared photovoltaic glass was subjected to performance tests:

[0043] Light transmittance test: The transmittance of the coated photovoltaic glass at 600 nm was tested using a UV-3600 spectrophotometer;

[0044] Adhesion test: The adhesion grade of the coating solution was tested by referring to the cross-cut test method disclosed in ISO2409-2013;

[0045] Hardness test: The hardness of the film layer on the surface of the photovoltaic glass was tested in accordance with GB / T 6739-1996 "Pencil Method for Determining Film Hardness";

[0046] Anti-scratch performance test: A reciprocating abrasion tester was used, and the surface of the film layer on the photovoltaic glass was reciprocally rubbed 2000 times with #0000 steel wool under a load of 500 g, and the change of the surface film layer was observed;

[0047] The test results are shown in Table 1:

[0048] Table 1: Performance test results

[0049] Light transmittance (%) Adhesion grade Hardness Scratch resistance Example 4 93.5 Grade 0 6H No change Example 5 93.8 Grade 0 6H No change Example 6 94.3 Grade 0 6H No change Comparative example 1 90.7 Grade 0 5H Slight change Comparative example 2 92.9 Grade 0 5H Slight change Comparative example 3 90.1 Grade 0 5H Slight change

[0050] As can be seen from Table 1, the coating solution prepared by the present invention forms a film layer on the surface of the photovoltaic glass. After testing the light transmittance, adhesion, hardness, and anti-scratch performance of the film layer, the film layer has excellent light transmittance, adhesion grade, hardness, and anti-scratch performance. Therefore, it has good application prospects when applied in photovoltaic modules.

[0051] The above content is only an example and illustration of the concept of the present invention. Those skilled in the art of this technology can make various modifications, supplements, or use similar methods to replace the specific embodiments described. As long as it does not deviate from the scope defined by the concept of the invention, it shall fall within the protection scope of the present invention.

Claims

1. A scratch-resistant coating solution for photovoltaic modules, characterized in that, It comprises the following raw materials in parts by weight: 10 - 15 parts of waterborne acrylic resin, 4 - 7 parts of silica sol, 5 - 9 parts of reinforcing agent, 2 - 5 parts of hydroxy silicone oil, 35 - 55 parts of isopropanol, and 25 - 45 parts of water; The reinforcing agent is prepared by graft reaction of ZnO NW@mSiO2 material and polyethylene glycol monomethyl ether. The ZnO NW@mSiO2 material is prepared by reaction of ZnO NW with tetraethyl orthosilicate and silane coupling agent KH560. The ZnO NW is prepared by chemical vapor deposition of zinc oxide.

2. The anti-scratch coating liquid for a photovoltaic module according to claim 1, wherein The reinforcing agent is prepared by the following steps: Step A1: Mix zinc oxide and activated carbon, add water and stir evenly, dry at 200 °C for 12 h, then place in a tube furnace, heat up to 900 °C, introduce a mixed gas, collect and grind to obtain ZnO NW; Step A2: Ultrasonically disperse cetyltrimethylammonium bromide, ZnO NW and water, add 2 mol / L sodium hydroxide solution, heat up to 70 °C and stir vigorously for 5 - 10 min, slowly add tetraethyl orthosilicate and silane coupling agent KH560 and stir to react for 30 - 50 min, add ethanol and ammonium nitrate, and reflux at 60 °C for 2 - 3 h, filter, wash and dry to obtain ZnO NW@mSiO2 material; Step A3: Mix ZnO NW@mSiO2 material and tetrabutylammonium bromide evenly in N,N - dimethylformamide, then add polyethylene glycol monomethyl ether, and react at 90 °C under nitrogen for 4 - 6 h, rotary evaporate, wash and dry to obtain the reinforcing agent.

3. The anti-scratch coating solution for a photovoltaic module according to claim 2, wherein In Step A1, the mass ratio of zinc oxide, activated carbon and water is 1:1:

5.

4. The anti-scratch coating solution for a photovoltaic module according to claim 2, characterized in that, In Step A1, the mixed gas is argon and oxygen, and the gas volume ratio is 10:

1.

5. The scratch-resistant coating solution for a photovoltaic module according to claim 2, characterized in that, In Step A2, the dosage ratio of cetyltrimethylammonium bromide, ZnO NW, water, sodium hydroxide solution, tetraethyl orthosilicate, silane coupling agent KH560, ethanol and ammonium nitrate is 0.5 - 1.5 g:1 - 5 g:50 mL:10 mL:0.2 - 0.4 mL:0.1 - 0.2 mL:100 mL:0.5 - 1.2 g.

6. A scratch-resistant coating solution for a photovoltaic module according to claim 2, characterized in that In Step A3, the dosage ratio of ZnO NW@mSiO2 material, tetrabutylammonium bromide, N,N - dimethylformamide and polyethylene glycol monomethyl ether is 5 - 10 g:0.001 - 0.003 mol:100 mL:0.01 - 0.02 mol.

7. A scratch-resistant coating solution for a photovoltaic module according to claim 2, wherein The molecular weight of the polyethylene glycol monomethyl ether in Step A3 is 350.

8. The production process of the anti-scratch coating solution for the photovoltaic module according to any one of claims 1-7, characterized in that, It comprises the following steps: Weigh the raw materials by parts by weight, mix and stir evenly waterborne acrylic resin, silica sol, reinforcing agent, hydroxy silicone oil, isopropanol and water at 35 - 45 °C, and cool to room temperature to obtain the anti - scratch coating liquid for photovoltaic modules.