KR20220034297A - Method for surface treatment of solar panel - Google Patents

Abstract

The present invention relates to a surface treatment method for solar panels. More specifically, the surface treatment method for solar panels comprises the following steps: preparing nanoparticles whose surfaces are coated with a silicon-carbon composite by vapor-depositing an alkoxysilane-based compound on the nanoparticles; mixing the nanoparticles coated with the silicon-carbon composite, a fluorosilane-based compound, tetrafluoroethylene, and a coating solution; and applying the mixed coating solution on a solar panel. According to the present invention, when the nanoparticles coated with alkoxy silane-based compounds is coated on the solar panel together with the coating solution, water repellency and high light transmittance are simultaneously provided to the surface of the solar panel. In addition, the method is simple and does not require expensive equipment, thereby providing advantages of requiring a relatively low cost and being applied to a large-area substrate to enlarge a solar panel.

Description

Method for surface treatment of solar panel {METHOD FOR SURFACE TREATMENT OF SOLAR PANEL}

The present invention relates to a method for surface treatment of a solar panel, and specifically, depositing an alkoxysilane-based compound on the nanoparticles in a vapor phase to prepare nanoparticles whose surface is coated with a silicon-carbon composite; mixing the silicon-carbon composite-coated nanoparticles with the fluorine-silane-based compound, tetrafluoroethylene and a coating solution; It relates to a solar panel surface treatment method comprising the step of applying the mixed coating solution on the solar panel.

In general, the surface of a material is largely divided into hydrophilic and hydrophobic depending on the degree of reaction with water. Hydrophilicity indicates that the surface is friendly with water, so that water droplets spread well on the surface.

In particular, the case where the contact angle with water drops of more than 150 degrees among hydrophobic surfaces is called super-hydrophobic, and its application fields range from simple applications such as waterproof glass or waterproof cloth to nano-implant, medical materials and sunlight, It is also used in the energy sector.

This superhydrophobicity is determined by two factors.

The first of these is a chemical factor, which is determined by the surface energy of a solid or the surface tension of a liquid droplet. When the surface energy of a solid is low, it shows hydrophobicity, and, conversely, when the surface energy is high, it shows hydrophilicity.

The second is a physical factor, and hydrophilicity or hydrophobicity changes depending on the roughness of the solid surface, that is, the roughness of the surface. When the above two factors are properly controlled on a solid surface, it is possible to form a superhydrophobic surface with a contact angle or a superhydrophilic surface with a contact angle close to 0°.

Such a superhydrophobic surface forms a high contact angle so that rain or dew drops form and roll off. Dust and dirt do not stick well due to this unique surface structure and are carried away as the water rolls off.

In particular, as interest in solar energy, which is a green energy, has recently increased, efforts are being made to develop high-efficiency solar cells. Since the efficiency of the solar cell is closely related to the transmittance, if the surface is always kept clean, the efficiency of the solar cell can be maintained. In this case, if the transparent conductive super water-repellent coating technology is used, it can be used as a technology to maintain the efficiency of the solar cell by maintaining the high transmittance of the glass without a separate cleaning process.

Republic of Korea Patent Registration No. 10-1362511

An object of the present invention is to provide a method for surface treatment of a solar panel that can be modified into a high-permeability super water-repellent surface by coating nanoparticles coated with a silicon-carbon composite on a solar panel.

In an embodiment of the present invention, depositing an alkoxysilane-based compound on the nanoparticles in a vapor phase to prepare nanoparticles whose surface is coated with a silicon-carbon composite; mixing the silicon-carbon composite-coated nanoparticles with the fluorine-silane-based compound, tetrafluoroethylene and a coating solution; And it provides a solar panel surface treatment method comprising the step of applying the mixed coating solution on the solar panel.

The alkoxy silane-based compound is from the group consisting of trimethoxyoctylsilane, trimethoxymethylsilane, vinyltrimethoxysilane, trimethoxydecilenesilane, and mixtures thereof. may be selected, but is not limited thereto.

The nanoparticles may be any one selected from the group consisting of SiO ₂ , ZnO, ITO, Al ₂ O ₃ and mixtures thereof, but is not limited thereto.

The fluorosilane-based compound may be selected from the group consisting of fluoroalkylsilane, polytetrafluoroethylene, polyfluoroalkoxy, and mixtures thereof, but is not limited thereto.

The silicon-carbon composite-coated nanoparticles, fluorine silane-based compound, tetrafluoroethylene, and the step of mixing with the coating solution include nanoparticles 50 to 70% by weight, fluorosilane compound 1 to 10% by weight, tetrafluoroethylene 1 ~ 10% by weight and 20 to 40% by weight of the coating solution may be mixed, but is not limited thereto.

The coating solution may include, but is not limited to, an acrylate-based compound, a crosslinking agent, a photoinitiator, a bonding improver, and a viscosity modifier.

The acrylate-based compound is 2-ethylhexyl acrylate (2-EHA); a mixture of 2-ethylhexyl acrylate (2-EHA) and methyl acrylate (MA); It may be selected from the group consisting of 2-ethylhexyl acrylate (2-EHA), acrylic acid (AA), and mixtures thereof, but is not limited thereto.

The cross-linking agent is dicumyl peroxide, the photoinitiator is 2,2'-azo-bis-isobutylnitrile (2,2'-azo-bis-isobutyrylnitrile - AIBN), the bond improver is an alkylsulfate and the viscosity modifier is a hydrophobic fumed It may be silica, but is not limited thereto.

The coating solution may include 70 to 90% by weight of an acrylate-based compound, 0.1 to 3% by weight of a crosslinking agent, 0.1 to 3% by weight of a photoinitiator, 1 to 5% by weight of a bonding improver, and 5 to 30% by weight of a viscosity modifier, but limited thereto doesn't happen

After the step of applying the mixed coating solution on the solar panel, the step of curing by irradiating UV light may be further included.

When the nanoparticles coated with the alkoxysilane compound according to the present invention are applied to the solar panel together with the coating solution, water repellency having high light transmittance can be imparted to the surface of the solar panel, and the method is simple and expensive equipment Since it is not used, the cost is relatively low, and it has the advantage that it can be applied on a large-area substrate and can be enlarged. Therefore, the self-cleaning effect of water droplets rolling on the surface without getting wet in the rain and sweeping away the dust appears, thereby preventing dust from accumulating on the surface and maintaining constant solar efficiency.

1 shows a flowchart of a method for surface treatment of a solar panel according to an embodiment of the present invention.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate that a feature, number, step, operation, component, part, or a combination thereof described in the specification exists, but one or more other features It is to be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

1 is a view showing a flowchart of a method for surface treatment of a solar panel according to an embodiment of the present invention, and the present invention will be described in more detail with reference to FIG. 1 below.

In an embodiment of the present invention, depositing an alkoxysilane-based compound on the nanoparticles in a vapor phase to prepare nanoparticles having a surface coated with a silicon-carbon composite (S110); mixing the silicon-carbon composite-coated nanoparticles with the fluorine-silane-based compound, tetrafluoroethylene and a coating solution (S120); And it provides a solar panel surface treatment method comprising the step (S120) of applying the mixed coating solution on the solar panel.

The step of preparing the nanoparticles (S110) is a step of preparing nanoparticles having superhydrophobicity by coating the surface of the nanoparticles with an alkoxysilane-based compound. vaporize.

In order to coat the surface of the conventional powder particles with a functional coating film, a liquid coating method has been used. This liquid coating method has a disadvantage in that it is difficult to form a thin and uniform coating film. In particular, in the case of superhydrophobic coating, in the liquid coating method, it is difficult to obtain a highly superhydrophobic surface because the coated surface has a rather low contact angle.

The present invention has a technical feature in that the surface of the powder particles is coated using vapor deposition of a silicon organic polymer in order to overcome the disadvantages of the prior art. This vapor deposition method is environmentally friendly because it does not require a solvent unlike the liquid phase deposition method.

The method has a technical feature in that it can be vapor-deposited using a liquid alkoxysilane-based compound. That is, the alkoxysilane-based compound may be used in a solution state and deposited by a dry-chemical method, rather than by a wet-chemical method.

Specifically, a liquid alkoxysilane-based compound is placed in a reaction vessel, a net-type separation membrane is placed on it, silica nanoparticles are placed on the separation membrane, and the reaction vessel is sealed, and then at a temperature of 2080 to 300° C. for 4 to 10 hours. By heating, silica nanoparticles coated with an alkoxysilane-based compound can be obtained.

The alkoxy silane-based compound is from the group consisting of trimethoxyoctylsilane, trimethoxymethylsilane, vinyltrimethoxysilane, trimethoxydecilenesilane, and mixtures thereof. may be selected, but is not limited thereto.

In addition, in the present invention, it is preferable to use particles having high transmittance as the nanoparticles, and examples thereof include SiO ₂ , ZnO, ITO and Al ₂ O ₃ nanoparticles.

As for the nanoparticles coated with the alkoxy silane-based compound by the above method, the silica nanoparticles have hydrophobic properties by the alkoxy silane-based compound.

In general, superhydrophobicity has a relationship in inverse proportion to the permeability of the superhydrophobic layer, and the superhydrophobicity of the surface has a larger value as the roughness of the surface increases. In addition, the greater the roughness of the surface, the greater the scattering on the surface occurs, and as a result, the transmittance of the super water-repellent layer is reduced.

Therefore, in order to avoid such a scattering phenomenon, it should have a surface roughness much smaller than that of the visible light region (400 to 700 nm). Therefore, the size of the nanoparticles forming the superhydrophobic layer preferably has a diameter of 100 nm or less, and more preferably has a diameter of 1 nm to 100 nm.

The prepared surface of the nanoparticles coated with the silicon-carbon composite is mixed with a fluorine-silane-based compound, tetrafluoroethylene, and a coating solution to be applied to the surface of the solar panel (S120).

The silicon-carbon composite-coated nanoparticles, fluorine silane-based compound, tetrafluoroethylene, and the step of mixing with the coating solution include nanoparticles 50 to 70% by weight, fluorosilane compound 1 to 10% by weight, tetrafluoroethylene 1 ~ 10% by weight and 20 to 40% by weight of the coating solution may be mixed, but is not limited thereto.

The silicon-carbon composite-coated nanoparticles are preferably added in an amount of 50 to 70% by weight relative to the total weight, and when added in an amount of less than 50% by weight, it is difficult to exhibit a super water-repellent effect, and when added in excess of 70% by weight There is a disadvantage in that the content of the coating solution is relatively reduced and the adhesive strength is weakened.

The fluorosilane-based compound may be selected from the group consisting of fluoroalkylsilane, polytetrafluoroethylene, polyfluoroalkoxy, and mixtures thereof, but is not limited thereto.

Such fluoroalkylsilane compounds are available as commercial products, for example under the trade name DYNASYLAN ^® F 8261 (tridecafluorooctyltriethoxycillin) from Degussa AG, 1H, 1H, 2H, 2H-perfluorodecyl trichlorosilane (FDTS), 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane and 1H, 1H, 2H, 2H-perfluorooctyltrichlorosilane, preferably 1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane is used.

The fluorosilane-based compound is preferably added in an amount of 1 to 10% by weight relative to the total weight, and when added in an amount of less than 1% by weight, it is difficult to exert a synergistic effect as in the following experimental example, and when added in excess of 10% by weight This is not preferable from a cost standpoint.

When the tetrafluoroethylene is added together with the fluorine silane compound, it was confirmed that the super water-repellent effect was increased. Preferably, the fluorine silane compound and tetrafluoroethylene may be added in a weight ratio of 1:1.

The tetrafluoroethylene is preferably added in an amount of 1 to 10% by weight based on the total weight like the fluorine silane compound, and when it is added in an amount of less than 1% by weight, it is difficult to exert a synergistic effect as in the following experimental example.

The coating solution may include, but is not limited to, an acrylate-based compound, a crosslinking agent, a photoinitiator, a bonding improver, and a viscosity modifier.

In addition, the coating solution is preferably added in an amount of 20 to 40 wt% based on the total weight, and when the coating solution is added in an amount of less than 20 wt%, the adhesive strength is weak, and when added in excess of 40 wt%, the silicone is relatively - There is a disadvantage in that the superhydrophobic effect is weakened due to the decrease in the amount of nanoparticles coated with the carbon composite.

The acrylate-based compound is 2-ethylhexyl acrylate (2-EHA); a mixture of 2-ethylhexyl acrylate (2-EHA) and methyl acrylate (MA); It may be selected from the group consisting of 2-ethylhexyl acrylate (2-EHA), acrylic acid (AA), and mixtures thereof, but is not limited thereto.

The acrylate-based compound may be included in an amount of 70 to 90% by weight based on the total weight of the coating solution.

The crosslinking agent is a material that acts as a crosslinking agent between the chain polymer chains, and the crosslinking imparts mechanical strength and chemical stability such as hardness or elasticity to the resin. An organic peroxide crosslinking agent may be used, and the organic Specific examples of the peroxide crosslinking agent include DTBP (Di-t-butyl peroxide), dicumyl peroxide, di-t-amyl peroxide, 2,5-dimethyl-2, 5-di(t-butylperoxy)hexane (2,5-Dimethyl-2,5-di(t-butylperoxy)hexane), and the like, but the present invention is not limited thereto. In addition, the content of the crosslinking agent is not particularly limited, but may be included in an amount of 0.1 to 3% by weight based on the total weight of the coating solution.

The photoinitiator may be used without limitation as long as it is known, for example, a cationic photoinitiator generating a cationic species or Lewis acid, a photoinitiator generating a radical, or a combination thereof.

For example, AIBN (azobisisobutyronitrile), ABCN (1,1'-Azobis (cyclohexanecarbonitrile)) or 2,2'-azobis-2,4-dimethylvaleronitrile (2,2'-azobis- (2,4) -dimethylvaleronitrile)), an azo-based initiator, or a peroxide-based initiator such as BPO (benzoyl peroxide) or DTBP (di-tert-butyl peroxide) may be applied.

The photoinitiator may be included in an amount of 0.1 to 3% by weight relative to the total weight of the coating solution, and when the amount of the photoinitiator is less than 0.1% by weight of the composition, it tends to have difficulty in curing by UV. When the amount of the photoinitiator is more than 3% by weight relative to the total weight of the coating solution, it tends to cure rapidly, and furthermore, a higher amount of the photoinitiator may result in a low molecular weight, which may result in a low cohesive strength.

The binding improver is for accelerating the reaction, and it is possible to add a commercially available inorganic acid, but an alkyl sulfate is preferable, and the alkyl sulfate may include ethyl sulfate, diethyl sulfate, or a mixture thereof.

As the bonding improver, the alkyl sulfate is preferably included in an amount of 1 to 5% by weight based on the total weight of the coating solution. If it is 1 wt% or less, it does not appear to be involved in the reaction, and if it is 5 wt% or more, it is seen as a critical value, so there is no change in reaction improvement even if additional addition is added.

The viscosity modifier controls the viscosity of the coating solution, and when hydrophobic fumed silica is added to the coating solution, the viscosity of the coating solution can be adjusted. The viscosity modifier may include 5 to 30% by weight based on the total weight of the coating solution, but is not limited thereto.

Hydrophobic fumed silica is obtained through surface treatment of inorganic silica with an organosilane compound (hydrophobic modifier), and is generally classified as hydrophobic fumed silica and precipitated silica according to the production process. The hydrophobic fumed silica powder may be obtained through surface chemical treatment of hydrophobic fumed silica powder with silane at a high temperature of 200 to 400° C., wherein a chemical process generally used is a fluidized bed process.

Hydrophobic fumed silica is also commercially available, for example, from Evonik Degussa Co., Ltd. under the product AEROSIL®; R972, R974, R104, R106, R202, R812, R812S, R816, R7200, R8200, R711, and R719, and the like.

When the solar panel surface treatment technology of the present invention is applied to the solar panel surface, the viscosity of the coating solution may facilitate the application of the technology of the present invention. For example, since the installed solar panel is inclined at a certain angle, if the viscosity is low, there may be difficulties in the process because the coating liquid flows down when applied to the installed solar panel. In this case, the viscosity of the coating solution may be adjusted with a viscosity modifier to make the manufacturing process advantageous.

The thickness of the coating solution mixed with nanoparticles, etc., applied on the solar panel can be flexibly controlled, but the thickness of the coating solution can affect the light transmittance, and therefore the transmittance decreases as the thickness increases. Manufacturing is important. Therefore, it is preferable that the thickness does not exceed 1 cm.

After the step of applying the mixed coating solution on the solar panel, the step of curing by irradiating UV light may be further included. The curing step may be performed for about 10 to 60 minutes.

In general, since the solar panel is exposed to sunlight, when the surface treatment method of the present invention is applied to an already installed solar panel, the UV irradiation step can be specifically omitted.

Hereinafter, the present invention will be described in more detail through examples. These examples are only for illustrating the present invention in more detail, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples according to the gist of the present invention. .

<Example>

1. Preparation of silica nanoparticles coated with silicon-carbon composites

Put trimethoxyoctylsilane in a stainless steel reaction vessel, place a net-type separator thereon, fill the upper part of the separator with silica nanoparticles having an average diameter of 12 nm, seal the reaction vessel, and 280°C to 300°C was heated for 6 hours to prepare trimethoxyoctylsilane-coated silica nanoparticles.

2. Coating silica nanoparticles coated with trimethoxyoctylsilane using a coating solution

A coating solution for coating the prepared silica nanoparticles on a substrate was prepared.

Coating solution composition Acrylate-based compounds 2-Ethylhexyl Acrylate (2-EHA) 80 wt% crosslinking agent dicumyl peroxide 1 wt% photoinitiator AIBN 1 wt% bond improver ethyl sulfate 3 wt% viscosity modifier Hydrophobic Fumed Silica 15 wt%

60% by weight of the trimethoxyoctylsilane-coated silica nanoparticles, 30% by weight of the coating solution, 5% by weight of fluoroalkylsilane (FDTS), and 5% by weight of tetrafluoroethylene (PTFE) were mixed on the substrate to 0.5 After coating to a thickness of cm and planarization, it was cured by irradiating UV.

<Comparative Example 1>

Except for fluoroalkylsilane (FDTS) and tetrafluoroethylene (PTFE), 60% by weight of trimethoxyoctylsilane-coated silica nanoparticles and 40% by weight of the coating solution were mixed, coated on a substrate, and planarized , was cured by UV irradiation.

<Comparative Example 2>

Except for fluoroalkylsilane (FDTS), 60% by weight of the trimethoxyoctylsilane-coated silica nanoparticles, 30% by weight of the coating solution, and 10% by weight of tetrafluoroethylene (PTFE) are mixed and coated on a substrate And after planarization, it was cured by irradiating UV.

<Comparative Example 3>

Except for tetrafluoroethylene (PTFE), 60% by weight of the trimethoxyoctylsilane-coated silica nanoparticles, 30% by weight of the coating solution, and 10% by weight of fluoroalkylsilane (FDTS) are mixed and coated on a substrate, After planarization, it was cured by UV irradiation.

<Comparative Example 4>

45% by weight of the trimethoxyoctylsilane-coated silica nanoparticles, 45% by weight of the coating solution, 5% by weight of fluoroalkylsilane (FDTS) and 5% by weight of tetrafluoroethylene (PTFE) are mixed and coated on a substrate And after planarization, it was cured by irradiating UV.

<Comparative Example 5>

30% by weight of the trimethoxyoctylsilane-coated silica nanoparticles, 60% by weight of the coating solution, 5% by weight of fluoroalkylsilane and 5% by weight of tetrafluoroethylene (PTFE) were mixed and coated on a substrate and planarized. Then, it was cured by UV irradiation.

<Experimental example>

1. Measurement of the contact angle of the coating surface

After dropping 3 μl of water on the coating surface prepared in Examples and Comparative Examples, the contact angle between the water droplet and the surface was measured. The results are shown in [Table 2], and the average value of 3 times was used for the specified contact angle.

Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 contact angle 168.24° 147.58° 150.65° 148.42° 132.35° 110.85°

Referring to [Table 2], in the case of the Example, the contact angle was the highest at 168.24°, and the comparative example showed a relatively low contact angle compared to the Example.

When any one of fluoroalkylsilane (FDTS) or tetrafluoroethylene (PTFE) was excluded, it was confirmed that the contact angle decreased compared to the example in which all were added, and when the coating solution was increased, trimethoxyoctylsilane was It is judged that the coated silica nanoparticles are present in the coating solution, thereby reducing the contact angle.

2. Light transmittance

The light transmittance was measured by UV-Vis-NIR spectroscopy. The wavelength range scanned to determine transmittance was 350-700 nm.

Example Comparative Example 1 Comparative Example 2 Comparative Example 3 light transmittance 97% 96% 97% 97%

Referring to [Table 3], the light transmittance is all 90% or more, it is judged that even when applied to the surface of the solar panel does not affect the solar efficiency.

As described above in detail a specific part of the present invention, for those of ordinary skill in the art, this specific description is only a preferred embodiment, and it is clear that the scope of the present invention is not limited thereto. Accordingly, the substantial scope of the present invention will be defined by the appended claims and their equivalents.

Claims (10)

depositing an alkoxysilane-based compound on the nanoparticles in a vapor phase to prepare nanoparticles having a surface coated with a silicon-carbon composite;
mixing the silicon-carbon composite-coated nanoparticles with the fluorine-silane-based compound, tetrafluoroethylene and a coating solution;
Solar panel surface treatment method comprising the step of applying the mixed coating solution on the solar panel.
According to claim 1,
The alkoxy silane-based compound is from the group consisting of trimethoxyoctylsilane, trimethoxymethylsilane, vinyltrimethoxysilane, trimethoxydecilenesilane, and mixtures thereof. Any one selected solar panel surface treatment method.
According to claim 1,
The nanoparticles are any one selected from the group consisting of SiO ₂ , ZnO, ITO, Al ₂ O ₃ and mixtures thereof.

According to claim 1,
The fluorine silane-based compound is any one selected from the group consisting of fluoroalkylsilane, polytetrafluoroethylene, polyfluoroalkoxy, and mixtures thereof A solar panel surface treatment method.
According to claim 1,
The mixing step is a solar panel surface treatment method of mixing 50 to 70% by weight of nanoparticles, 1 to 10% by weight of a fluorine silane compound, 1 to 10% by weight of tetrafluoroethylene, and 20 to 40% by weight of the coating solution.
According to claim 1,
The coating solution is a solar panel surface treatment method comprising an acrylate-based compound, a crosslinking agent, a photoinitiator, a bonding improver and a viscosity modifier.
7. The method of claim 6,
The acrylate-based compound is 2-ethylhexyl acrylate (2-EHA); a mixture of 2-ethylhexylacrylate (2-EHA) and methyl acrylate (MA); A method for surface treatment of a solar panel selected from the group consisting of 2-ethylhexyl acrylate (2-EHA), acrylic acid (AA), and mixtures thereof.
7. The method of claim 6,
the crosslinking agent is dicumyl peroxide, the photoinitiator is 2,2'-azo-bis-isobutylnitrile (2,2'-azo-bis-isobutyrylnitrile - AIBN), the bond improver is an alkylsulfate and the viscosity modifier is a hydrophobic fumed A method of surface treatment of a solar panel that is silica.
7. The method of claim 6,
The coating solution is a solar panel surface treatment comprising 70 to 90% by weight of an acrylate-based compound, 0.1 to 3% by weight of a crosslinking agent, 0.1 to 3% by weight of a photoinitiator, 1 to 5% by weight of a bonding improver, and 5 to 30% by weight of a viscosity modifier method.
According to claim 1,
Solar panel surface treatment method further comprising a curing step of irradiating UV after the application step.

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