KR20160028235A - Monolayer hydrophobic coating composition improved anti-reflection efficiency for solar cell - Google Patents

Abstract

The present invention relates to an antireflection coating composition for a solar cell, which comprises organic-inorganic modified silicate, a nanosized refraction reducing agent, hydrophobic colloidal silica, and a curing accelerating agent. Different from a conventional multilayer coating having three or four layers, the antireflection coating composition in the present invention is constituted to have a single layer, thereby shortening manufacturing process and reducing manufacturing costs. Also, the antireflection coating composition of the present invention can prevent contamination through self-cleaning by having hydrophobic character and thus can remarkably increase light efficiency. Further, the coating composition of the present invention can secure excellent physical properties such as hardness, adhesion strength, contamination resistance, transparency, etc. In addition, costs of the raw materials constituting the composition is inexpensive and thus the composition of the present invention can be manufactured at one-third of a conventional manufacturing costs, thereby being applicable as an anti-reflection coating for mobile devices, electronic devices, etc.

Description

[0001] The present invention relates to a coating composition for a solar cell antireflection film having an improved antireflection ratio,

The present invention relates to a coating composition for a solar cell antireflection film having an improved antireflection ratio and, more particularly, to a coating composition for a solar cell antireflection film which is excellent in physical properties such as hardness, stain resistance, self-cleaning property, transparency and light efficiency, To a coating composition for a solar cell antireflection film capable of significantly reducing the manufacturing cost.

Recently, efforts have been made to develop alternative energy such as generation of electricity using solar light, generation of electricity using wind power, and the like using technologies utilizing natural energy in terms of energy saving and efficiency and prevention of global warming. Due to the fact that the sun is an infinite energy source, the development of solar cells, especially solar cells, has been commercialized among many companies. However, the biggest problem in the development of photovoltaic cells is to increase the efficiency of solar power. In fact, some companies are trying to increase the efficiency of each part of the solar cell. For some foreign companies, the coating film is designed to increase the transmittance of sunlight to the outer glass of the solar cell and prevent reflection. .

Generally, it is well known that when a low refractive index film is formed on an upper layer of a substrate, the reflectance of an external light source is lowered. In the case of the antireflection film, the antireflection film is somewhat difficult to manufacture because it is transparent, unlike the antiglare film. However, because of its superior image sharpness, it is widely applied to high resolution or high quality products.

In the production of the antireflection film, a PET film is used as a base film in the PDP filter field, and a TAC film supporting both sides of a PVA polarizing film is used in an LCD polarizer field. The types of antireflective films produced by coating these two base films are basically four layers of HARD, high refractive index, low refractive index and contamination. You can make different kinds of film depending on how you choose and how you combine them.

Among these types, the transparent antireflection film can be divided into a single layer and a multilayer antireflection film depending on the number of layers of the antireflection film on the hard coating layer. The antireflection film of the single layer is a structure in which the low refractive layer is coated on the hard layer in a thickness of? / 4 so that the light reflected at the interface between the air low refractive layer and the hard layer of the low refractive layer may cause a mutual outbreak. Is called a low reflection film in order to distinguish it from an anti-reflection film.

In the structure of the antireflection film, a hard coating layer for imparting scratch resistance is provided in order to secure the weak scratch characteristics of the substrate, and the reflectance is lowered using only a low refractive index monolayer thereon, A two-layered low-reflection product is produced which forms an antireflection film by double coating a composition having the same or different refractive index. However, in this case, there is a problem that the antireflection effect is about 2% and the antireflection effect is not sufficient. In order to solve such a problem, an antireflection film having a three-layer structure in which a high refraction layer is coated on a hard coating layer and a low refraction layer is coated on the hard coating layer is manufactured. These products have a reflectance of about 1% In the case of the three-layer structure, there arises a problem of having a specific color due to its optical characteristics. Recent trends in the film market require films with a reflectance of 1% without reflecting colors, and products with much reduced reflection color are being released through optimal optical design that controls refractive index and thickness of each layer.

In recent years, anti-reflection films using four layers have also been attempted, and studies are underway to improve the reflectance characteristics of the anti-reflection films using a two- or three-layer structure.

In addition, there is a method of coating an antireflection film having a nano-rod on the surface of a substrate as in Korean Patent Publication No. 2012-0094550, but a planarization process of the surface to be coated is necessarily required, and a hydrothermal reaction process is required to form the nano- There are disadvantages.

Korean Patent Publication No. 10-2012-0027652 (March 22, 2012) Korean Patent Publication No. 10-2012-0094550 (Aug. 27, 2012)

SUMMARY OF THE INVENTION The present invention has been conceived to solve the problems described above. It is an object of the present invention to provide a single layer antireflection film coating which is excellent in physical properties such as hardness, stain resistance, self-cleansing property, transparency and light efficiency, And to provide a coating composition for a solar cell antireflection film.

The present invention relates to a coating composition for a solar cell antireflection film.

One aspect of the present invention relates to a coating composition for a solar cell antireflection coating comprising an oil-in-modified silicate, a nanodecomposing agent, a hydrophobic colloidal silica, and a curing accelerator.

In the present invention, the composition may include 10 to 30% by weight of an organic-inorganic modified silicate, 5 to 20% by weight of a nano-low refractive agent, 40 to 75% by weight of a hydrophobic colloidal silica, and 1 to 10% by weight of a curing accelerator.

In the present invention, the organic-inorganic modified silicate may be a silane coupling agent having a structure represented by the following formula (1); An alkali metal silicate of at least one selected from lithium silicate, potassium silicate and sodium silicate; Acrylic emulsion; And water.

[Chemical Formula 1]

Wherein n is an integer from 1 to 10 and R is selected from the group consisting of (C1-C10) alkyl, (C1-C10) fluorinated alkyl, (C1-C10) alkoxyalkyl, It can be any one or more.)

Further, the nano-hypoid refractory agent is any one or two or more selected from calcium fluoride, lithium fluoride, barium fluoride, magnesium fluoride, sodium fluoride, aluminum fluoride and hollow silica, and the hydrophobic colloidal silica is selected from the group consisting of sodium silicate, And may have an average particle diameter of 0.1 to 1 mu m.

In the present invention, the nano-hypochlorite may be more specifically calcium fluoride, and the calcium fluoride may be synthesized as a mixture of calcium chloride and sodium fluoride, and may have an average particle diameter of 1 to 50 nm.

In the present invention, the curing accelerator may include one or more selected from phosphoric acid, hydrofluoric acid, hydrochloric acid, nitric acid, acetic acid, formic acid, citric acid and oxalic acid.

The coating composition for a solar cell antireflection film according to the present invention is composed of a single layer, unlike the conventional multilayer coating film of three or four or more layers, and can reduce manufacturing process and manufacturing cost. The efficiency can be greatly increased.

FIG. 1 is a scanning electron microscope (SEM) image of a hydrophobic colloidal silica prepared according to an example of the present invention. The magnification is 100,000 times.

Hereinafter, the coating composition for a solar cell antireflection film according to the present invention will be described in more detail with reference to specific examples or examples. It should be understood, however, that the invention is not limited thereto and that various changes and modifications may be made without departing from the spirit and scope of the invention.

Unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Also, the singular forms as used in the specification and the appended claims are intended to include the plural forms as well, unless the context clearly indicates otherwise.

As a result of continuous experiments and studies to improve existing complex and expensive multi-layer antireflection film coating agents and coating systems, the inventors have found that the present inventors have found that the use of an organic-inorganic modified silicate, a nanodorring agent, a hydrophobic colloidal silica and a curing accelerator The present invention has been accomplished based on the discovery that the antireflection film composition exhibits light conversion efficiency equivalent to that of a multilayer film even when it is prepared as a single layer, and further exhibits excellent properties in terms of hardness, stain resistance, self-cleaning property and transparency.

The term " hollow " as used in the present invention means an empty space inside surrounded by the constituent of the shell, and the term " cavity "

A coating composition for a solar cell antireflection film having an improved antireflection ratio according to the present invention comprises (A) an organic-inorganic modified silicate, (B) a nanodecomposing agent, (C) a hydrophobic colloidal silica, and (D) Lt; / RTI >

Each component will be described in more detail below.

(A) oil-modified silicate

Conventionally, organic silanes such as methyltrimethoxysilane, methyltriethoxysilane and the like were used as coating compositions for antireflection coatings. Such organosilanes have a low reactivity and, after high heat treatment, change color on the surface of the glass or fail to exhibit desired adhesive properties, resulting in degradation of quality. On the other hand, the present organic or inorganic silicate has a higher reactivity than the organosilane, and can exhibit sufficient adhesive properties even at a low firing temperature of 500 DEG C or less.

The oil-in-modified silicate according to the present invention is a silane coupling agent having a structure represented by the following formula (1); An alkali metal silicate of at least one selected from lithium silicate, potassium silicate and sodium silicate; Acrylic emulsion; And water.

[Chemical Formula 1]

Wherein n is an integer of 1 to 10;

R may be any one or more selected from among (C1-C10) alkyl, (C1-C10) fluorinated alkyl, (C1-C10) alkoxyalkyl and (C1-

In the present invention, the silane coupling agent improves the compatibility of the alkali metal silicate with the acrylic emulsion and imparts water repellency to the oil-modified silicate composition. The effect of the silane coupling agent may vary depending on the substituted R in the chemical formula 1 .

In the present invention, the alkyl group is not particularly limited, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec- A straight chain or branched chain alkyl group such as a hexyl group, a heptyl group, an octyl group and a 2-ethylhexyl group.

The fluorinated alkyl group is not particularly limited, and examples thereof include a fluoromethyl group, a 1-fluoroethyl group, a 1-fluoropropyl group, a 1-fluorobutyl group, And a 1-fluorooctyl group.

Examples of the alkoxyalkyl group include methoxymethyl, 1-methoxyethyl, 2-methoxyethyl, 3-methoxybutyl, 1-ethoxyethyl, 2-ethoxyethyl, propoxyethyl group, iso-propoxyethyl group, n-butoxyethyl group, n-butoxyethyl group, 1-tert- A butoxymethyl group, a tert-butoxymethyl group, and a propoxypropyl group.

In the present invention, the aminoalkyl group is added to improve the compatibility of the alkali metal silicate with the acrylic emulsion. For example, an aminoethylaminopropyl group, an aminopropyl group, a methacryloxypropyl group, a glycidoxypropyl group, .

From the viewpoint of reactivity, R is preferably an alkyl group having 1 to 4 carbon atoms, a fluorinated alkyl group having 1 to 4 carbon atoms or an alkoxyalkyl group having 3 to 6 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms Particularly preferably a methyl group or an ethyl group.

In the present invention, the alkali metal silicate is a combination of an alkali metal oxide and silicon dioxide, and the alkali metal may be any one or two or more selected from lithium, sodium, and potassium. Preferably, it is sodium.

The molar ratio of the alkali metal oxide to silicon dioxide is preferably 1: 3 to 5, and the solid content of the alkali metal silicate may be 40 to 50 wt%, but the present invention is not limited thereto.

In the present invention, the acrylic emulsion is added to improve the water resistance of the alkali metal silicate. The acrylic emulsion has a solid content of 40% by weight and a pH of 8 or higher.

The oil-in-modified silicate composition according to the present invention does not limit the composition ratio, but it is preferable that the composition contains 55 to 90% by weight of an alkali metal silicate, 1 to 20% by weight of a silane coupling agent, 1 to 5% by weight of an acrylic emulsion, And 1 to 20% by weight of water.

In the present invention, only the organosilicate containing an alkyl group such as methyl, ethyl, isopropyl and the like is described, but the above-mentioned effect is also exhibited by using an inorganic silicate including an alkaline earth metal, a metalloid and a transition metal Are within the scope of the present invention.

In the present invention, the content of the organic-inorganic modified silicate may be appropriately adjusted in consideration of the firing temperature and the adhesive strength, but may be in the range of 10 to 30% by weight based on 100% by weight of the total composition. When the addition amount of silicate is less than 10% by weight, the scratch resistant hardness effect may not be exhibited. When the addition amount is more than 30% by weight, adverse effect on the product price increase and low reflectance characteristics may occur.

(B) nano-hypochlorite

In the present invention, the nanodecomposing agent is added to control the refractive index of the antireflection film. Generally, the antireflection film coating composition determines the reflectance according to the refractive index. That is, in terms of the reflectance, the lower the refractive index is, the lower the reflectance characteristic is exhibited, but the surface strength of the coating film becomes weaker. However, in the present invention, the use of the organic-inorganic modified silicate and the catalyst component can secure the surface strength of the coating film, and at the same time, the light efficiency characteristics can be increased due to the use of the nanodispersing agent.

Further, the nanodispersing agent according to the present invention can have hollows and have a low hollow ratio. Therefore, the nanodispheres according to the present invention can be used not only as an optical material but also as a film layer having a function required on the surface of a display device, As well as a raw material for a coating liquid, and can secure a low dielectric constant.

The nano-hypoid refractory agent used in the present invention may be selected from metal fluorides such as calcium fluoride, lithium fluoride, barium fluoride, magnesium fluoride, sodium fluoride, aluminum fluoride and the like, and hollow silica. In addition, a metal oxide may be used. More preferably, the use of calcium fluoride is preferable because it has properties of high-transparency, corrosion resistance, heat stability and hardness while having low refractive index.

The calcium fluoride according to the present invention can be synthesized with a mixture of calcium chloride and sodium fluoride, but is not limited thereto and preferably has an average particle diameter of 1 to 50 nm. Generally, when the particle size is smaller than 1/2 (? / 2) of the incident light wavelength, for example, when the particle is a nano unit, the total reflection reduction effect can be achieved by reducing the refractive index. Lt; / RTI > Therefore, it is preferable that the range of the average particle diameter satisfies the above range.

The nanodecomposing agent according to the present invention may be in the range of 5 to 20% by weight based on 100% by weight of the total composition, but is not particularly limited thereto. When the nano-refractor is added in an amount of less than 5% by weight, the antireflection effect may not be exhibited. If the nano-refractor is added in an amount exceeding 20% by weight, the product may be disadvantageously increased in price.

(C) Hydrophobic colloidal silica

In the present invention, the hydrophobic colloidal silica is for imparting self-cleaning property to the antireflection film. The hydrophobic colloidal silica has surface irregularities, so that even if the surface of the coating film, which is a coating layer, is contaminated, it exhibits a function similar to a lotus effect, so that an additive such as a photocatalyst is not needed.

The hydrophobic colloidal silica according to the present invention is synthesized with a mixture of sodium silicate, boric acid and urea, and may have an average particle diameter of 0.1 to 1 탆. When the average particle diameter is out of the range, the average particle diameter may be too small to increase the manufacturing cost. If the average particle diameter is too large, the transparency of the product after coating may be deteriorated.

The hydrophobic colloidal silica may be added in an amount of 40 to 75% by weight based on 100% by weight of the total composition. If less than 40% by weight is added, the self-cleansing effect may be insufficient, and when it is more than 75% by weight, the total refractive index may be increased compared to the nano-low refractive index agent.

(D) Curing accelerator

The curing accelerator functions as a thickener, and when the curing accelerator itself is coated on glass or a film, it is mixed with other ingredients to affect the viscosity, and the viscosity of the coating composition on the glass substrate is increased to improve the coating property . In addition, it plays a crucial role in promoting the adhesion of organic or inorganic modified silicates to lower the firing temperature.

Examples of the curing accelerator which can be used in the present invention include any one or more of inorganic acids selected from phosphoric acid, hydrofluoric acid, hydrochloric acid, nitric acid, etc., or any one or more organic acids selected from acetic acid, formic acid, citric acid and oxalic acid, And the present invention is not limited thereto.

The content of the curing accelerator may be appropriately adjusted in consideration of the adhesive force and the transparency of the coating film, and preferably 1 to 10% by weight based on 100% by weight of the total composition. If less than 1% by weight of the antireflection film is added, the effect of improving the adhesion is not sufficiently exhibited. If the amount of the antireflection film is more than 10% by weight, the viscosity of the antireflection film may be decreased.

The coating composition for a solar cell antireflection film according to the present invention may further include additives conventionally used in the art, such as a viscosity modifier, an inorganic filler and the like in addition to the above-mentioned components.

In the present invention, a solar cell antireflection film can be produced using the above-described composition. One preferred embodiment thereof is as follows. However, the present invention is not limited thereto.

1) A coating film is formed by spray coating the composition on the surface of a transparent substrate.

The transparent substrate to which the composition is applied may be a transparent substrate such as plastic, glass, resin, ceramics, or film, or may be a mirror-finished silicon wafer or transparent oxide electrode. A double glass substrate is preferred, and such a glass substrate may be a low iron tempered glass. The composition for forming an antireflection film is spray-coated on both sides of the transparent substrate as described above. In this case, the thickness of the composition is adjusted to less than 3 μm, preferably 1 μm or less, in consideration of light transmittance and antireflection effect.

In addition to the above-described spray coating method, conventional coating methods known in the art may be performed. Examples thereof include spin coating, flow coating, roll court coating, , And a screen printing method.

2) Then, the double-side coated transparent substrate is heat-treated for 10 to 30 minutes at a temperature of 500 ° C or lower, preferably 200 ° C to 500 ° C using a sintering furnace or a hot-air drying furnace.

The present invention can provide an antireflection film for a solar cell and a solar cell having the antireflection film formed on a transparent substrate and including a coating film formed from the coating composition described above.

At this time, the thickness of the coating film formed from the composition can be appropriately adjusted according to the refractive index of the material and the wavelength of the incident light. When the thickness of the coating is too thick, the antireflection effect can not be exhibited due to the decrease in transmittance. Therefore, it may be in the range of 0.3 mu m to 3 mu m, preferably in the range of 0.1 mu m to 1 mu m. The coating film may be formed on one side or both sides of the transparent substrate.

In the present invention, the anti-reflection film is applied to the solar cell application, but it is also within the scope of the present invention that the anti-reflection film is applied to a display device requiring an anti-reflection effect. The field requiring the antireflection effect may be a display such as a cathode ray tube (CRT), a color picture tube (CPT), a liquid crystal display (LCD), a plasma display panel (PDP), an organic EL A device or an optical field such as glasses, an optical filter, and an optical lens.

The coating composition for a solar cell antireflection coating according to the present invention may further include a diol compound having a structure of the following formula (2) to further enhance light transmission and antireflection properties.

(2)

Wherein Rf is (C6-C24) arylene substituted with at least one fluorine.

In the present invention, the diol compound is an oligomer having an aromatic ring in its main chain, and has excellent heat resistance, transparency, and high compatibility with other coating compositions.

,

,

,

,

In the present invention, Rf in the formula (2)

,

,

,

,

, And two or more diol compounds different from each other in the substituted arylene represented by the general formula (2) may be used in combination.

In the present invention, the diol compound may be contained in an amount of 0.01 to 0.2% by weight based on 100% by weight of the total coating composition for a solar cell antireflection film. When the amount of the diol compound is less than 0.01% by weight, the effect of improving the physical properties is insufficient. When the amount of the diol compound is more than 0.2% by weight, the surface hardness may decrease and the mechanical properties may be deteriorated.

Hereinafter, the present invention will be described in more detail with reference to examples. It is to be understood, however, that the following examples are for illustrative purposes only and are not intended to limit the scope of the present invention in any way.

The method for measuring physical properties of a specimen produced according to the present invention and the method for producing the composition are as follows.

(reflectivity)

UV / VIS / NIR spectrometer (Lambda 950, Perkin-Elmer). The incident angle was set to 8 degrees, and the reflectance of the reflected light with respect to the specular light was measured. The reflectance averages in the range of 380 to 780 nm were calculated for the measured reflectance values.

(Light transmittance)

As to the light transmittance, a black paint was applied to the back surface (the side opposite to the antireflection film) of the transparent substrate to prepare a test piece, and the reflectance of the test piece was measured by a spectrophotometer in a visible light region (400 to 700 nm). In addition, the reflectance of the transparent substrate on which the antireflection film was not formed (Hanslas Co., Ltd., low iron float glass) was 6.2%. For the light transmittance measurement, the transmittance was measured using a Hitachi U-3300 at a wavelength of 380 to 700 nm.

(Hardness)

Measured according to JIS K5400, and pencil hardness was measured by applying a load of 1 kg / cm < 2 > with a pencil hardness of 45 degrees.

(Adhesion / adhesion)

100 mass scales were formed with a cross cut of 1 mm in width and the number of film fragments remaining on the substrate was measured by a peeling test using an adhesive tape to show that all the fragments of the film remained. A case where the number of film fragments was 50 to 99 was evaluated as?, And a case where the number of remaining film fragments was less than 50 was evaluated as?.

(Self cleaning)

The coated surface of the glass specimens was contaminated with oil magic, dried at room temperature (20 ° C) for 5 minutes, and washed with running water to evaluate the degree of disappearance of the magic contamination. At this time, evaluation methods were classified into excellent (⊚), excellent (◯), normal (Δ), bad (Δχ), and very bad (Χ).

(Thickness of film)

And measured by MCPD-2000 manufactured by Otsuka Denshi Co., Ltd.

(Hydrophobic colloidal silica)

1.5 M of sodium silicate (manufactured by Young Il Chemical Co., Ltd.), 0.1 M of boric acid (Duksan Chemical Co., Ltd.), 0.1 M of element made of irregular silica (Duksan Chemical Co., Ltd.) and alcohol as a solvent were used as starting materials. Ethanol was used as a solvent. The silica powder having surface irregularities was prepared by using an ultrasonic spray pyrolysis apparatus, adding the above mixed solution at a flow rate of 3 L / min by a pump, spraying solutions by a nitrogen carrier gas through an electric furnace Dried or sintered. The silica thus obtained has a surface irregularly shaped powder as shown in Fig. 1, which has a hydrophobic property such as a soft petal effect. The powder thus obtained was put into an isopropyl alcohol solvent with a solid content of 10 wt% and dispersed for 3 hours through mechanical ball milling to prepare colloidal silica.

(Nanofluorinated calcium)

300 g of distilled water and 3.75 g of sodium fluoride (NaF) (Duksan Chemical Co.) were mixed with 600 g of distilled water and 7.5 g of calcium chloride aqueous solution (CaCl ₂ 6H ₂ O) (Duksan Chemical Co.) The solution was added dropwise at a flow rate of about 0.33 ml / min using a microfeed pump and stirred for 2 hours until it became clear. All the reactions were carried out at room temperature. After the stirring was completed, sodium chloride (NaCl) was removed by washing with distilled water three times. The powder was separated at a speed of 3,000 rpm using a centrifuge, dried at 70 ° C for 24 hours, and then dispersed in an isopropyl alcohol solvent to a solid content of 3%.

(Example 1)

The ethyl silicate adjusted to isopropyl alcohol solvent to the solid content of 3% (YWG, 01 Mars products, pH 11, specific gravity (20 ℃) 1,200, LiO ₂ content of 2.1 wt%, SiO ₂ content of 20 wt.%, Viscosity (20 ℃) 50 cps) were weighed and stirred at room temperature. The hydrophobic colloidal silica prepared directly was converted into a 3% solids solution in an isopropyl alcohol solvent, and 722 g of the solution was mixed. Then, a 3% solids-directly prepared nano-fluorinated calcium solution dispersed in isopropyl alcohol solvent And 22 g of a 1% phosphoric acid aqueous solution were added and mixed for 30 minutes to prepare the coating composition of Example 1. [

Next, both sides of the glass were coated to a thickness of 300 nm using a spray coating system. After the coating was completed, the coating was annealed in a baking furnace at 230 ° C for 20 minutes. After the heat treatment, reflectance, transmittance and hardness were measured. The results are shown in Table 2 below.

(Example 2 and Comparative Examples 1 to 4)

An antireflection film was prepared in the same manner as in Example 1 except that the addition amount of the coating composition was changed as shown in Table 1 below. However, the diol added to Example 2 has the following formula (3). The reflectance, transmittance and hardness of the manufactured antireflection film were measured and the results are shown in Table 2 below.

(3)

[Table 1]

[Table 2]

In the case of Comparative Example 1 and Comparative Example 3 showing the experimental results of the hydrophobic colloidal silica and the content of the nano-low refractive agent, when the content of the nano-low refractive agent was constant and the content of the hydrophobic colloidal silica was increased, 1 and 3, haze of the coating film lowers the light transmittance, and in Comparative Examples 2 and 3 and 4 in which the content of the curing agent and the curing accelerator is decreased or increased, respectively, the pencil hardness is remarkably decreased have. Also, it can be seen that there is no change in hardness improvement even when too much curing accelerator is added.

On the other hand, in Example 1 of the present invention, the coating composition and the coating system of the present invention showed a high light transmittance of 97% or more, and showed very high hardness and self-cleaning properties. In addition, Example 2 in which a diol compound was further added showed the best reflectance and light transmittance in all of Examples and Comparative Examples.

Therefore, a method of increasing the efficiency of the solar cell due to the antireflection film coating composition and coating system according to the present invention can be provided. Further, the antifouling property can be improved according to the self-cleaning property of the hydrophobic coating composition for a solar cell having the above-mentioned antireflection ratio.

In addition, when the hydrophobic coating composition for a solar cell having an improved antireflection ratio according to the present invention is used, it is expected that the application range of the hydrophobic coating composition for solar cells will be very large even in other mobile devices.

Claims (8)

A coating composition for a solar cell antireflective coating comprising an organic-inorganic modified silicate, a nano-low refractive agent, a hydrophobic colloidal silica, and a curing accelerator. The method according to claim 1,
The composition comprises a coating for a solar cell antireflective coating comprising 10 to 30% by weight of an organic-inorganic modified silicate, 5 to 20% by weight of a nanodecomposing agent, 40 to 75% by weight of a hydrophobic colloidal silica, and 1 to 10% Composition. The method according to claim 1,
Wherein the organic-inorganic modified silicate is a silane coupling agent having a structure represented by the following formula (1); An alkali metal silicate of at least one selected from lithium silicate, potassium silicate and sodium silicate; Acrylic emulsion; And water. The coating composition for a solar cell antireflection film according to claim 1,
[Chemical Formula 1]

Wherein n is an integer of 1 to 10;
R may be any one or more selected from among (C1-C10) alkyl, (C1-C10) fluorinated alkyl, (C1-C10) alkoxyalkyl and (C1- The method according to claim 1,
Wherein the nano-refractor is at least one selected from calcium fluoride, lithium fluoride, barium fluoride, magnesium fluoride, sodium fluoride, aluminum fluoride, and hollow silica. The method according to claim 1,
The hydrophobic colloidal silica is synthesized from a mixture of sodium silicate, boric acid and urea, and has an average particle diameter of 0.1 to 1 占 퐉. 5. The method of claim 4,
Wherein the nanodecal refractor is calcium fluoride. The method according to claim 6,
Wherein the calcium fluoride is synthesized from a mixture of calcium chloride and sodium fluoride and has an average particle diameter of 1 to 50 nm. The method according to claim 1,
Wherein the curing accelerator comprises one or more selected from phosphoric acid, hydrofluoric acid, hydrochloric acid, nitric acid, acetic acid, formic acid, citric acid and oxalic acid.

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