KR20190088838A - a coating composition for anti-reflection - Google Patents

Abstract

The present invention relates to an anti-reflective coating composition and a production method of a porous anti-reflective film and, more specifically, to an anti-reflective coating composition comprising polysilazane, a titanium dioxide precursor and a solvent, and to a method for producing a porous anti-reflective film therefrom. The anti-reflective coating composition can lower the refractive index and the reflectance of a porous silica membrane and increase the transmittance, and has excellent low temperature curing properties, hydrophilicity and durability. In addition, the present invention has excellent hardness, hydrophilicity, durability, adhesive strength, transmittance, etc. by using the polysilazane having the excellent low temperature curing properties, and thus the production method of a porous anti-reflective film can be used for a long time stably used in solar cells, polarizing plates, liquid crystal display devices, lenses, etc.

Description

A coating composition for anti-reflection < RTI ID = 0.0 >

The present invention relates to an antireflective coating composition and a process for producing a porous antireflective film, and more particularly, to an antireflective coating composition comprising a polysilazane, a titanium dioxide precursor and a solvent, and a method for producing a porous antireflective film therefrom .

Recently, as the importance of environmental problems becomes more important, hydroelectric power generation, wind power generation, and solar power generation are attracting attention as clean energy.

Among them, solar power generation using solar energy has been studied variously because it uses sun which is infinite energy and is useful for preventing global warming.

Solar cells using semiconductors such as monocrystalline silicon, polycrystalline silicon, and amorphous silicon have practiced the principle of emitting current when a semiconductor is irradiated with sunlight.

Solar cells generally include a solar cell module manufactured by protecting a solar cell element such as silicon, gallium-arsenic, copper-indium-selenium, etc. with an upper transparent protective material and a lower substrate protective material, and fixing the solar cell element and the protective material with an adhesive do.

In the solar cell module, the upper protective material typically uses glass. However, since the glass reflects sunlight, the power generation efficiency of the solar cell module is lowered.

Various studies such as using an antireflection film have been conducted to solve this problem.

Korean Patent Laid-Open Publication No. 10-2013-0015935 discloses a process for producing a water-soluble polymer composition comprising (meth) acrylate monomer (A), nanosilica particles (B), quaternary ammonium salt (C), alcohol- ). ≪ / RTI > A < RTI ID = 0.0 > antireflective coating composition < / RTI >

Korean Patent Laid-Open No. 10-2013-0021182 discloses a composition comprising a (meth) acrylate monomer; Hollow silica nanoparticles; Quaternary ammonium salts; A mixed solvent of an alcohol-based solvent and a ketone-based solvent; And a photopolymerization initiator. ≪ Desc / Clms Page number 2 >

Korean Patent No. 10-1205477 discloses a (meth) acrylate-based compound having a first molecular weight; A (meth) acrylate-based compound having a second molecular weight greater than the first molecular weight; Inorganic fine particles; (Meth) acrylate-based compound having a second molecular weight, wherein the (meth) acrylate-based compound has a structure in which at least two molecules of a (meth) acrylate-based compound having a first molecular weight are linked by a linker Coating compositions.

However, the technology disclosed in the above document can not stably use the solar cell module for a long period of time because the refractive index and reflectance of the antireflection film are high, the transmittance is low, and the low temperature curing property is poor.

Korean Patent Publication No. 10-2013-0015935 Korean Patent Publication No. 10-2013-0021182 Korean Patent No. 10-1205477

The object of the present invention is to provide an antireflective coating composition capable of lowering the refractive index and reflectivity of a porous silica film and increasing the transmittance, and having excellent low temperature curing properties, hydrophilicity and durability. have.

The present invention also relates to a porous antireflection film which is excellent in hardness, hydrophilicity, durability, adhesive force and transmittance by using polysilazane excellent in low-temperature curing property and can be stably used for a long time in a solar cell, a polarizing plate, a liquid crystal display, And a method for producing the same.

In order to accomplish the above object, the present invention provides a composition comprising polysilazane; Titanium dioxide precursors; Surfactants; And a solvent.

In one embodiment of the present invention, the composition comprises 3 to 15 parts by weight of polysilazane, 1 to 10 parts by weight of a titanium dioxide precursor, and 1 to 5 parts by weight of a surfactant, based on 100 parts by weight of the solvent.

In one embodiment of the present invention, the titanium dioxide precursor is selected from the group consisting of titanium tetramethoxide, titanium tetraethoxide, titanium tetra n-propoxide, titanium tetraisopropoxide, titanium tetra n-butoxide, Is selected from the group consisting of titanium halide, titanium halide, titanyl sulfate and titanylbis (acetylacetonate).

In one embodiment of the present invention, the solvent is at least one selected from diethyl ether, dipropyl ether, dibutyl ether, benzene, toluene and xylene.

In one embodiment of the present invention, the composition further comprises a co-solvent.

In one embodiment of the present invention, the composition comprises 3 to 15 parts by weight of polysilazane, 1 to 10 parts by weight of a titanium dioxide precursor, 1 to 5 parts by weight of a surfactant, and 1 to 10 parts by weight of a co- And the like.

In one embodiment of the present invention, the co-solvent is at least one selected from the group consisting of methanol, ethanol, mineral spirit, kerosene, ethyl acetate, dimethyl carbonate and diacetone alcohol.

The present invention also provides a method of cleaning a substrate, comprising: (a) washing the substrate; (b) polysilazane; Titanium dioxide precursors; Surfactants; Preparing a coating composition for antireflective coating comprising a solvent and a solvent; (c) coating the coating composition on at least one side of the substrate to form an antireflective layer; And (d) heat treating the antireflection layer to produce a porous silica film.

In one embodiment of the present invention, the composition of step (b) comprises 3 to 15 parts by weight of polysilazane, 1 to 10 parts by weight of titanium dioxide precursor and 1 to 5 parts by weight of a surfactant based on 100 parts by weight of the solvent And the like.

In one embodiment of the present invention, the titanium dioxide precursor is selected from the group consisting of titanium tetramethoxide, titanium tetraethoxide, titanium tetra n-propoxide, titanium tetraisopropoxide, titanium tetra n-butoxide, Is selected from the group consisting of titanium halide, titanium halide, titanyl sulfate and titanylbis (acetylacetonate).

In one embodiment of the present invention, the solvent is at least one selected from diethyl ether, dipropyl ether, dibutyl ether, benzene, toluene and xylene.

In one embodiment of the present invention, the composition of step (b) is characterized in that it further comprises a cosolvent.

In one embodiment of the present invention, the composition of step (b) comprises 3 to 15 parts by weight of polysilazane, 1 to 10 parts by weight of a titanium dioxide precursor, 1 to 5 parts by weight of a surfactant, And 1 to 10 parts by weight.

In one embodiment of the present invention, the co-solvent is at least one selected from the group consisting of methanol, ethanol, mineral spirit, kerosene, ethyl acetate, dimethyl carbonate and diacetone alcohol.

The present invention can provide an antireflective coating composition which can lower the refractive index and reflectance of a porous silica film, increase the transmittance, and exhibit low temperature curing properties, hydrophilicity and durability.

The present invention also relates to a porous antireflection film which is excellent in hardness, hydrophilicity, durability, adhesive force and transmittance by using polysilazane excellent in low-temperature curing property and can be stably used for a long time in a solar cell, a polarizing plate, a liquid crystal display, A manufacturing method can be provided.

Hereinafter, the present invention will be described in detail based on examples. It is to be understood that the terminology, examples and the like used in the present invention are merely illustrative of the present invention in order to more clearly explain the present invention and to facilitate understanding of the ordinary artisan, and should not be construed as being limited thereto.

Technical terms and scientific terms used in the present invention mean what the person skilled in the art would normally understand unless otherwise defined.

The present invention relates to an antireflective coating composition comprising a polysilazane, a titanium dioxide precursor, a surfactant and a solvent.

The coating composition may comprise 3 to 15 parts by weight of polysilazane, 1 to 10 parts by weight of a titanium dioxide precursor, and 1 to 5 parts by weight of a surfactant, based on 100 parts by weight of the solvent.

The polysilazane is a polymer compound having Si-N-Si bonds, and the silica film is formed by the polysilazane being converted to silica through heat treatment.

A silica film is prepared from the polysilazane by heat treatment, and in this process, the solvent and the surfactant are removed, and a large number of pores are formed in the silica film.

The pores formed in the film lower the refractive index and reflectance of the film and increase the transmittance.

Polysilazane is excellent in reactivity with moisture relative to other silacar precursors, and it is easy to produce an antireflection film having excellent hardness, hydrophilicity, durability and adhesive strength.

The weight average molecular weight of the polysilazane is preferably 1,000 to 30,000 g / mol, more preferably 5,000 to 20,000 g / mol. When the weight average molecular weight is less than 1,000 g / mol, the hardness and durability are reduced. When the weight average molecular weight is more than 30,000 g / mol, the workability and coating property are lowered.

The polysilazane is used in an amount of 3 to 15 parts by weight based on 100 parts by weight of the solvent. When the content of the polysilazane is less than 3 parts by weight, the strength and durability of the film deteriorate. When the content of the polysilazane exceeds 15 parts by weight, And the durability is rather lowered.

The titanium dioxide precursor promotes low-temperature curing of the polysilazane, and is converted into titanium dioxide while being hydrolyzed during the heat treatment process to simultaneously impart hydrophilicity to the antireflection film.

As the titanium dioxide precursor, one or more selected from titanium alkoxide, titanium halide such as titanium tetrachloride, titanyl sulfate and titanylbis (acetylacetonate) may be used.

The titanium alkoxide is a Ti (OR) ₄ compound, wherein R is preferably C1-C6 alkyl.

As the titanium alkoxide, titanium tetramethoxide, titanium tetraethoxide, titanium tetra n-propoxide, titanium tetraisopropoxide, titanium tetra n-butoxide, titanium tetraisobutoxide and the like can be used.

Titanium tetraisopropoxide is preferably used as the titanium dioxide precursor in terms of low-temperature curing properties, hydrophilicity, hardness and durability of the antireflection film.

The titanium dioxide precursor is used in an amount of 1 to 10 parts by weight, preferably 3 to 7 parts by weight, based on 100 parts by weight of the solvent. When the content is less than 1 part by weight, the effect of addition is insignificant. When the content exceeds 10 parts by weight, uniform pores can not be formed, and the permeability and durability of the membrane are rather lowered.

The solvent controls the viscosity of the composition, and at least one selected from diethyl ether, dipropyl ether, dibutyl ether, benzene, toluene and xylene can be used.

It is preferable that dibutyl ether is used as a solvent in terms of the transmittance, hardness and durability of the antireflection film.

The surfactant improves the uniformity and coatability of the composition and is removed by heat treatment to form a plurality of pores in the silica film.

Examples of the surfactant include polyoxyethylene alkyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene-polyoxypropylene block copolymer, sorbitan fatty acid ester, polyoxyethylene Sorbitan fatty acid esters, polyethylene glycol, polyethylene glycol monooleate, polyethylene glycol distearate, sorbitan monooleate, sorbitan monostearate, sorbitan monolaurate, polyoxyethylene alkylphenyl ether, oleic acid, octanoic acid, Linoleic acid, stearic acid and lauric acid can be used.

Polyethylene glycol monooleate, polyethylene glycol distearate, sorbitan monooleate and polyoxyethylene nonylphenyl ether are preferably used as the surfactant in terms of the transmittance, hardness and durability of the antireflection film.

The surfactant is used in an amount of 1 to 5 parts by weight based on 100 parts by weight of the solvent. When the content of the surfactant is less than 1 part by weight, the effect of addition is insignificant. When the amount exceeds 5 parts by weight, uniform pores can not be formed, .

The composition of the present invention may further include a co-solvent, and the co-solvent improves the coating property of the composition and increases the porosity of the film, thereby improving the transmissivity of the film.

The co-solvent may be at least one selected from the group consisting of methanol, ethanol, mineral spirit, kerosene, ethyl acetate, dimethyl carbonate and diacetone alcohol. Methanol is preferred from the viewpoints of membrane permeability and durability.

The composition may comprise 3 to 15 parts by weight of polysilazane, 1 to 10 parts by weight of a titanium dioxide precursor, 1 to 5 parts by weight of a surfactant, and 1 to 10 parts by weight of a co-solvent, based on 100 parts by weight of the solvent.

The co-solvent is preferably used in an amount of 1 to 10 parts by weight with respect to 100 parts by weight of the solvent. When the content is less than 1 part by weight, workability and coating properties are deteriorated, and when exceeding 10 parts by weight, permeability and durability of the film are deteriorated.

The composition may further comprise 1 to 5 parts by weight of a silica precursor based on 100 parts by weight of the solvent, and the silica precursor may form a silica film by heat treatment to improve the strength and durability of the film.

Examples of the silica precursor include alkoxysilanes such as tetramethoxysilane (TMOS) and tetraethoxysilane (TEOS), sodium silicate, potassium silicate, and silicon tetrachloride. Ethoxysilane is preferably used.

The silica precursor is used in an amount of 1 to 5 parts by weight. When the content is less than 1 part by weight, the effect of addition is insignificant. When the content is more than 5 parts by weight, the transmittance of the film is lowered.

Hydrogen chloride, nitric acid, acetic acid, ammonium hydroxide, ammonia water, sodium hydroxide, potassium hydroxide, and the like may be used without limitation to promote the hydrolysis of the polysilazane and the silica precursor, and ammonia water is preferably used.

The composition may further include 1 to 5 parts by weight of silica nanoparticles relative to 100 parts by weight of the solvent, and the silica nanoparticles may improve the strength and durability of the membrane.

When the content of the silica nanoparticles is less than 1 part by weight, the effect of addition is insignificant. When the content of the silica nanoparticles exceeds 5 parts by weight, the transmittance of the membrane is decreased.

The diameter of the silica nanoparticles is preferably 20 to 100 nm, more preferably 50 to 80 nm. When the diameter satisfies the above numerical range, the hardness and durability can be improved without lowering the transmittance of the film.

The silica nanoparticles may be surface treated with a silane coupling agent.

The silane coupling agent has an organic functional group capable of bonding with an organic compound and a hydrolytic group capable of reacting with an inorganic substance and has an effect of increasing the interfacial adhesion between the substrate and the coating composition and the interfacial adhesion between the components constituting the silica film, Properties, transmittance, hydrophilicity, hardness, durability and the like can be improved.

As the silane coupling agent, an alkyl group-containing silane, an amino group-containing silane, an epoxy group-containing silane, an acrylate group-containing silane, an isocyanate group-containing silane, a mercapto group-containing silane, a fluorine group-containing silane,

The content of the silane coupling agent is preferably 1 to 10 parts by weight based on 100 parts by weight of the nanoparticles. When the content is less than 1 part by weight, it is difficult to expect an improvement in adhesion. When the amount exceeds 10 parts by weight, The interface adhesion property, the transmittance and the durability are lowered.

It is particularly preferable to use a silane coupling agent mixture composed of 60 to 90% by weight of an isocyanate group-containing silane coupling agent and 10 to 40% by weight of an acrylate group-containing silane coupling agent.

The composition of the present invention may further comprise 1 to 5 parts by weight of a silane coupling agent oligomer prepared by previously reacting an isocyanate group-containing silane coupling agent and an acrylate group-containing silane coupling agent with respect to 100 parts by weight of the solvent.

By using the silane coupling agent oligomer, the adhesion, workability, transmittance, durability and the like of the silica film can be improved.

The silane coupling agent oligomer preferably has a weight average molecular weight of 1,000 to 5,000 g / mol, and when the content of the silane coupling agent oligomer is less than 1 part by weight, the effect of addition is insignificant. When the amount of the silane coupling agent oligomer is more than 5 parts by weight, .

The present invention also provides a method of cleaning a substrate, comprising: (a) washing the substrate; (b) polysilazane; Titanium dioxide precursors; Surfactants; Preparing a coating composition for antireflective coating comprising a solvent and a solvent; (c) coating the coating composition on at least one side of the substrate to form an antireflective layer; And (d) heat-treating the antireflection layer to produce a porous silica film.

The step (a) is a step of removing dust, oil, organic compounds, contaminants and the like. The substrate may be heated to 600 to 700 ° C or the substrate may be washed with a washing solution of demineralized water, alcohol, acidic or basic.

The substrate may be a film, a sheet or a substrate such as a glass, a quartz, a polyethylene terephthalate, a polyethylene naphthalate or the like, a polyamide, a polycarbonate, a polymethyl methacrylate, a polystyrene or the like.

The composition of step (b) may include 3 to 15 parts by weight of polysilazane, 1 to 10 parts by weight of titanium dioxide precursor, and 1 to 5 parts by weight of surfactant, based on 100 parts by weight of the solvent.

Also, the composition of step (b) includes 3 to 15 parts by weight of polysilazane, 1 to 10 parts by weight of titanium dioxide precursor, 1 to 5 parts by weight of a surfactant and 1 to 10 parts by weight of a co-solvent based on 100 parts by weight of the solvent .

The step (c) is a step of coating the coating composition on at least one side of the substrate, and a known coating method may be used.

Coating methods include bar coating, meniscus coating, spray coating, roll coating, spin coating and dip coating.

The coating speed in the step (c) is preferably 30 to 70 mm / s. When the coating speed satisfies the above-described numerical range, the pores of the prepared film are uniformly formed, and the durability and the transmittance are maximized

The step (d) may be a step of preparing a porous silica film by heat-treating the antireflection layer, and the heat treatment may be performed at 25 to 800 ° C.

When the heat treatment temperature satisfies the above-described numerical range, the pores of the produced film are uniformly formed, and the durability, hydrophilicity and transmittance can be maximized.

  A silica film is prepared from the polysilazane by heat treatment, and a plurality of pores are formed in the silica film while the surfactant, solvent, decomposition materials and the like are removed.

The pores formed in the film lower the refractive index and reflectance of the film and increase the transmittance.

The thickness of the porous silica film can be variously adjusted as required, and is preferably 10 to 2,000 nm.

The antireflection film can be stably used for a long period of time in a solar cell, a polarizing plate, a liquid crystal display, a lens, and the like because its hardness, hydrophilicity, durability and transmittance are not reduced even when used for a long period of time.

Particularly, the titanium dioxide converted from the titanium dioxide precursor promotes the low-temperature curing (25 to 400 ° C) of the polysilazane, so that the anti-reflection film not only has excellent low-temperature curing characteristics but also increases the hydrophilicity.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. The following examples are intended to illustrate the practice of the present invention and are not intended to limit the scope of the present invention.

(reflectivity)

The adapter MPC 2200 was attached to a spectrophotometer UV 2450, and the specular reflectance was measured with respect to an exit angle of 5 deg. At an incident angle of 5 deg. In a wavelength range of 380-780 nm, and an average reflectance of 450-650 nm was calculated.

(Transmittance)

The total light transmittance was measured using a transmittance meter (HM-150) according to ASTM D 1003.

(Surface hardness)

Using a pencil hardness tester, a pencil hardness of a porous silica film prepared from the above Examples and Comparative Examples was measured under a load of 500 g.

The pencil was made five times per pencil hardness using Mitsubishi products.

(Contact angle)

To investigate the hydrophilicity of the prepared porous silica membrane, distilled water was dropped on the surface of the porous silica membrane and the contact angle was measured.

(Example 1)

The glass substrate was cleaned with a cleaning agent to remove dust, oil, organic compounds, and contaminants present in the substrate.

10 parts by weight of polysilazane, 5 parts by weight of a titanium dioxide precursor (titanium tetraisopropoxide), 3 parts by weight of a surfactant (sorbitan monooleate) and 100 parts by weight of a solvent (dibutyl ether) .

The glass substrate was coated with the coating composition by bar coating to form an antireflection layer.

The antireflective layer was heat-treated at 400 ° C for 10 minutes (low temperature curing) to prepare a porous silica film.

(Example 2)

A porous silica membrane was prepared in the same manner as in Example 1, except that 0.5 part by weight of a titanium dioxide precursor (titanium tetraisopropoxide) was used.

(Example 3)

A porous silica membrane was prepared in the same manner as in Example 1, except that 12 parts by weight of a titanium dioxide precursor (titanium tetraisopropoxide) was used.

(Example 4)

A porous silica membrane was prepared in the same manner as in Example 1 except that 5 parts by weight of a co-solvent (methanol) was further used.

(Example 5)

A porous silica membrane was prepared in the same manner as in Example 4 except that 3 parts by weight of tetraethoxysilane was additionally used.

(Example 6)

Except that 3 parts by weight of a silane coupling agent oligomer prepared by previously reacting 70% by weight of 3-isocyanate propyltriethoxysilane and 30% by weight of 3-methacryloxypropyltrimethoxysilane was additionally used A porous silica membrane was prepared.

(Comparative Example 1)

A porous silica membrane was prepared in the same manner as in Example 1 except that tetraethoxysilane was used instead of polysilazane.

(Comparative Example 2)

A porous silica film was prepared in the same manner as in Example 1, except that the titanium dioxide precursor (titanium tetraisopropoxide) was not used.

The reflectance, the transmittance, the surface hardness (durability) and the contact angle of the porous silica film prepared from the above Examples and Comparative Examples were measured and the results are shown in Table 1 below.

division Example Comparative Example One 2 3 4 5 6 One 2 reflectivity(%) 1.4 1.7 1.8 1.1 1.2 1.0 2.3 2.6 Transmittance (%) 93.6 92.6 92.2 94.1 94.2 94.5 90.5 90.9 Surface hardness 7H 4H 4H 7H 7H 7H 2H 2H Contact angle (°) 15 38 16 16 15 15 65 72

From the results shown in Table 1, Examples 1 to 6 show that titanium dioxide promotes low-temperature curing of the polysilazane, thereby lowering the refractive index and reflectance of the porous silica film and increasing the transmittance, Hardness, hydrophilicity and durability are excellent.

On the other hand, Comparative Examples 1 and 2 are inferior in transmittance, surface hardness, hydrophilicity, durability and low temperature curing properties as compared with Examples 1 to 6.

Claims (14)

Polysilazane;
Titanium dioxide precursors;
Surfactants; And
≪ / RTI > a solvent.
The method according to claim 1,
Wherein the composition comprises 3 to 15 parts by weight of polysilazane, 1 to 10 parts by weight of a titanium dioxide precursor, and 1 to 5 parts by weight of a surfactant based on 100 parts by weight of the solvent.
3. The method of claim 2,
The titanium dioxide precursor is selected from the group consisting of titanium tetramethoxide, titanium tetraethoxide, titanium tetra n-propoxide, titanium tetraisopropoxide, titanium tetra n-butoxide, titanium tetraisobutoxide, titanium halide, And titanylbis (acetylacetonate). ≪ Desc / Clms Page number 24 >
The method of claim 3,
Wherein the solvent is at least one selected from diethyl ether, dipropyl ether, dibutyl ether, benzene, toluene and xylene.
The method according to claim 1,
≪ / RTI > wherein said composition further comprises a co-solvent.
6. The method of claim 5,
Wherein the composition comprises 3 to 15 parts by weight of polysilazane, 1 to 10 parts by weight of a titanium dioxide precursor, 1 to 5 parts by weight of a surfactant, and 1 to 10 parts by weight of a co-solvent, based on 100 parts by weight of the solvent. Coating composition.
The method according to claim 6,
Wherein the co-solvent is at least one selected from the group consisting of methanol, ethanol, mineral spirit, kerosene, ethyl acetate, dimethyl carbonate, and diacetone alcohol.
(a) washing the substrate;
(b) polysilazane; Titanium dioxide precursors; Surfactants; Preparing a coating composition for antireflective coating comprising a solvent and a solvent;
(c) coating the coating composition on at least one side of the substrate to form an antireflective layer; And
(d) heat treating the antireflection layer to produce a porous silica film.
9. The method of claim 8,
Wherein the composition of step (b) comprises 3 to 15 parts by weight of polysilazane, 1 to 10 parts by weight of a titanium dioxide precursor, and 1 to 5 parts by weight of a surfactant, based on 100 parts by weight of the solvent. A method for producing an antireflection film.
10. The method of claim 9,
The titanium dioxide precursor is selected from the group consisting of titanium tetramethoxide, titanium tetraethoxide, titanium tetra n-propoxide, titanium tetraisopropoxide, titanium tetra n-butoxide, titanium tetraisobutoxide, titanium halide, And titanylbis (acetylacetonate). ≪ RTI ID = 0.0 > 11. < / RTI >
11. The method of claim 10,
Wherein the solvent is at least one selected from diethyl ether, dipropyl ether, dibutyl ether, benzene, toluene and xylene.
9. The method of claim 8,
Wherein the composition of step (b) further comprises a co-solvent.
13. The method of claim 12,
The composition of the step (b) comprises 3 to 15 parts by weight of polysilazane, 1 to 10 parts by weight of a titanium dioxide precursor, 1 to 5 parts by weight of a surfactant, and 1 to 10 parts by weight of a co-solvent based on 100 parts by weight of a solvent Wherein the porous antireflection film has a thickness of 100 nm or less.
14. The method of claim 13,
Wherein the co-solvent is at least one selected from the group consisting of methanol, ethanol, mineral spirit, kerosene, ethyl acetate, dimethyl carbonate, and diacetone alcohol.