KR101921328B1 - a coating composition for anti-reflection - Google Patents

Abstract

The present invention relates to an antireflective coating composition and a method for producing a porous antireflective coating, and more particularly, to an antireflective coating composition comprising a polysilazane, a surfactant and a solvent, and a method for producing a porous antireflective coating therefrom .
The present invention can provide an antireflective coating composition capable of lowering the refractive index and reflectance of a porous silica film and increasing the transmittance.
The present invention also provides a method for producing a porous antireflection film which can be stably used for a long time in a solar cell, a polarizing plate, a liquid crystal display device, a lens, etc. by using a polysilazane excellent in low temperature curing property and having excellent hardness, durability, adhesive force, Can be provided.

Description

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

The present invention relates to an antireflective coating composition and a method for producing a porous antireflective coating, and more particularly, to an antireflective coating composition comprising a polysilazane, a surfactant and a solvent, and a method for producing a porous antireflective coating 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 technique disclosed in the above document has a high refractive index and reflectance of the antireflection film and a low transmittance, and can not be stably used for a long time in the solar cell module.

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

It is an object of the present invention to provide an antireflective coating composition capable of lowering the refractive index and reflectance of a porous silica film and increasing the transmittance.

The present invention also provides a method for producing a porous antireflection film which can be stably used for a long time in a solar cell, a polarizing plate, a liquid crystal display device, a lens, etc. by using a polysilazane excellent in low temperature curing property and having excellent hardness, durability, adhesive force, And to provide the above objects.

In order to accomplish the above object, the present invention provides a coating composition for antireflection comprising polysilazane, a surfactant and a solvent.

In one embodiment of the present invention, the composition comprises 1 to 10% by weight of polysilazane, 1 to 15% by weight of a surfactant, and 75 to 95% by weight of a solvent.

In one embodiment of the present invention, the surfactant is selected from the group consisting of polyethylene glycol, polyethylene glycol monooleate, polyethylene glycol distearate, sorbitan monooleate, sorbitan monostearate, sorbitan monolaurate, polyoxyethylene alkyl Phenyl ether, oleic acid, octanoic acid, linoleic acid, stearic acid and lauric acid.

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 is characterized by comprising 1 to 10% by weight of polysilazane, 1 to 15% by weight of a surfactant, 45 to 95% by weight of a solvent and 3 to 50% by weight of a co-solvent .

In one embodiment of the present invention, the co-solvent is at least one selected from mineral spirits, 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; 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 1 to 10% by weight of polysilazane, 1 to 15% by weight of a surfactant, and 75 to 95% by weight of a solvent.

In one embodiment of the present invention, the surfactant is selected from the group consisting of polyethylene glycol, polyethylene glycol monooleate, polyethylene glycol distearate, sorbitan monooleate, sorbitan monostearate, sorbitan monolaurate, polyoxyethylene alkyl Phenyl ether, oleic acid, octanoic acid, linoleic acid, stearic acid and lauric acid.

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 1 to 10% by weight of polysilazane, 1 to 15% by weight of a surfactant, 45 to 95% by weight of a solvent and 3 to 50% .

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

The present invention can provide an antireflective coating composition capable of lowering the refractive index and reflectance of a porous silica film and increasing the transmittance.

The present invention also provides a method for producing a porous antireflection film which can be stably used for a long time in a solar cell, a polarizing plate, a liquid crystal display device, a lens, etc. by using a polysilazane excellent in low temperature curing property and having excellent hardness, durability, adhesive force, 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 surfactant and a solvent.

The coating composition may comprise 1 to 10% by weight of polysilazane, 1 to 15% by weight of a surfactant and 75 to 95% by weight of a 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.

The silica film is prepared from the polysilazane by heat treatment, and the surfactant and the solvent 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.

The antireflection film produced by the polysilazane can be cured at a low temperature (25 to 200 ° C). The antireflection film thus produced has excellent hardness, durability and adhesion, and even if it is left at room temperature after the antireflection film is cured, The hardness and durability of the barrier film are maintained or increased.

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.

When the content is less than 1% by weight, the strength and durability of the film deteriorate. When the content is more than 10% by weight, a uniform coating layer can not be formed, and the permeability and durability of the membrane deteriorate do.

The surfactant improves the uniformity and coatability of the composition and is removed by heat treatment to form a large number 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 15 wt%, preferably 7 to 12 wt%. When the content is less than 1% by weight, the transmittance of the film is lowered. When the content is more than 15% by weight, uniform pores can not be formed, and the transmittance and durability of the film are 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.

In view of the transmittance, hardness and durability of the antireflection film, dibutyl ether and xylene are preferably used as the solvent.

The solvent is preferably used in an amount of from 75 to 95% by weight. When the content is less than 75% by weight, processability and coating properties are deteriorated. When the content is more than 95% by weight, permeability and durability of the film are deteriorated.

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.

As the co-solvent, at least one selected from mineral spirits, kerosene, ethyl acetate, dimethyl carbonate, and diacetone alcohol may be used, and kerosene and dimethyl carbonate are preferable from the viewpoints of membrane permeability and durability.

The composition may comprise 1 to 10% by weight of polysilazane, 1 to 15% by weight of a surfactant, 45 to 95% by weight of a solvent and 3 to 50% by weight of a co-solvent.

The co-solvent is preferably used in an amount of 3 to 50 wt%, and when the content is less than 3 wt%, the processability and coating properties are deteriorated. When the content is more than 50 wt%, the permeability and durability of the film are deteriorated.

The composition may further comprise 1 to 5% by weight of a silica precursor, 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% by weight. When the content is less than 1% by weight, the effect of addition is insignificant. When the content is more than 5% 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 comprise 1 to 5% by weight of silica nanoparticles, and the silica nanoparticles may improve the strength and durability of the membrane.

When the content of the silica nanoparticles is less than 1% by weight, the effect of addition is insignificant. When the content of the silica nanoparticles exceeds 5% by weight, the transmittance of the film 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, 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 a fluorine 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% by weight of a silane coupling agent oligomer prepared by previously reacting a fluorine group-containing silane coupling agent and an acrylate group-containing silane coupling agent.

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

The weight average molecular weight of the silane coupling agent oligomer is preferably 1,000 to 5,000 g / mol, and the silane coupling agent oligomer is preferably used in an amount of 1 to 5% by weight. When the content is less than 1% by weight, the effect of addition is insignificant. When the content exceeds 5% by weight, workability and transmittance are lowered.

The present invention also provides a method of cleaning a substrate, comprising: (a) washing the substrate; (b) polysilazane; 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 comprise 1 to 10% by weight of polysilazane, 1 to 15% by weight of a surfactant, and 75 to 95% by weight of a solvent.

The composition of step (b) may further comprise 3-50 wt% of a co-solvent, 1-5 wt% of a silica precursor, 1-5 wt% of a silica nanoparticle, and / or 1-5 wt% of a silane coupling agent oligomer .

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

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 can be uniformly formed, and the durability and transmittance can be maximized.

 The silica film is prepared from the polysilazane by heat treatment, and the surfactant and the solvent 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.

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

The antireflection film does not decrease in hardness, durability, and transmittance even when it is used for a long time, and can be used for a long time for a solar cell, a polarizing plate, a liquid crystal display, a lens and the like.

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.

(Transmittance)

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

(Surface hardness)

The pencil hardness of the prepared porous silica membrane was measured by using a pencil hardness tester under a load of 500 g.

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

(Example 1)

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

An antireflective coating composition comprising 5% by weight of polysilazane, 2 to 10% by weight of a surfactant (sorbitan monooleate or polyoxyethylene nonylphenyl ether) and a solvent (dibutyl ether or xylene) was prepared.

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

The antireflective layer was heat-treated at 600 ° C for 5 minutes to prepare a porous silica film.

The transmittance and the surface hardness of the porous silica film were measured, and the results are shown in Table 1 below.

division coating
Way Content of polysilazane
(weight%) Surfactants menstruum Application amount
(Μl) thickness Transmittance
(%) Rate of increase Hardness Comparison 1 - - - - - - 90.39 - - Comparison 2 Bar 5 5 - Dibutyl ether 250 308 90.77 0.38 9H One A
(2% by weight) 261 91.12 0.73 9H 2 A
(5% by weight) 468 91.39 1.00 2H 3 A
(10% by weight) 649 92.19 1.80 2H Comparison 3 - Xylene 335 90.52 0.13 9H 4 A
(2% by weight) 439 91.12 0.73 9H 5 A
(5% by weight) 572 91.16 0.77 6H 6 A
(10% by weight) 686 91.76 1.37 6H 7 B
(2% by weight) 365 91.19 0.80 9H 8 B
(5% by weight) 473 91.39 1.00 3H 9 B
(10% by weight) 622 92.21 1.82 3H

A: sorbitan monooleate, B: polyoxyethylene nonylphenyl ether

From the results shown in Table 1, when the solvent is dibutyl ether, the transmittance increases with increasing content of the surfactant sorbitan monooleate, and the transmittance is 92.19% when the content is 10% by weight.

On the other hand, the transmittance of Comparative Example 2, which did not use a surfactant, was as low as 90.77%.

When the solvent was xylene, the transmittance increased as the surfactant content increased. When the content was 10 wt%, the transmittance was 91.76% and 92.21%, respectively.

On the other hand, the transmittance of Comparative Example 3, which did not use a surfactant, was as low as 90.52%.

(Example 2)

A porous silica membrane was prepared in the same manner as in Example 1, except that the surfactant was changed.

The transmittance and surface hardness of the porous silica film were measured, and the results are shown in Table 2 below.

division coating
Way Content of polysilazane
(weight%) Surfactants menstruum Application amount
(Μl) thickness Transmittance
(%) Rate of increase Hardness Comparison 1 - - - - - - 90.39 - - Comparison 2 Bar 5 5 - Dibutyl ether 250 308 90.77 0.38 9H One C
(1% by weight) 363 90.95 0.56 9H 2 C
(5% by weight) 658 91.82 1.43 2H 3 C
(10% by weight) 743 92.01 1.62 2H Comparison 3 - Xylene 335 90.52 0.13 9H 4 D
(5% by weight) 536 91.86 1.47 6H 5 D
(10% by weight) 911 92.19 1.80 6H 6 C
(1% by weight) 384 90.83 0.44 9H 7 C
(5% by weight) 561 91.87 1.87 3H 8 C
(10% by weight) 887 92.00 1.61 3H

C: polyethylene glycol distearate, D: polyethylene glycol monooleate

From the results shown in Table 2, when the solvent was dibutyl ether, the permeability increased as the content of polyethylene glycol distearate, which is a surfactant, was increased. When the content was 10 wt%, the permeability was 92.01%.

On the other hand, the transmittance of Comparative Example 2, which did not use a surfactant, was as low as 90.77%.

When the solvent was xylene, the transmittance increased as the surfactant content increased. When the content was 10 wt%, the transmittance was 92.19% and 92.00%, respectively.

On the other hand, the transmittance of Comparative Example 3, which did not use a surfactant, was as low as 90.52%.

(Example 3)

A porous silica membrane was prepared in the same manner as in Example 1, except that the co-solvent was used.

The transmittance and surface hardness of the porous silica film were measured and the results are shown in Table 3 below.

division coating
Way Content of polysilazane
(weight%) Surfactants menstruum Co-seller Transmittance
(%) Rate of increase Hardness Comparison 1 - - - - - 91.87 - - Comparison 2 Bar 5 2.5 C
(1.5% by weight) Dibutyl ether - 93.37 1.50 9H One Kerosene 3 wt% 93.33 1.46 9H 2 10 wt% 93.58 1.71 9H 3 20 wt% 93.47 1.60 9H 4 E 3 wt% 93.46 1.59 9H 5 10 wt% 93.80 1.93 9H 6 20 wt% 93.17 1.30 9H

C: polyethylene glycol distearate, E: dimethyl carbonate

From the results shown in Table 3, the transmittance increased with the co-solvent, and the transmittance was 93.58% and 93.80% when the co-solvent content was 10% by weight.

On the other hand, the transmittance of the comparative 2 without the co-solvent was 93.37%, which was somewhat lower than that of the co-solvent.

Claims (14)

Polysilazane;
Surfactants;
menstruum; And
1. An antireflective coating composition comprising a co-solvent,
Wherein the composition comprises 1 to 10% by weight of polysilazane, 1 to 15% by weight of a surfactant, 45 to 95% by weight of a solvent and 3 to 50% by weight of a co-
The surfactant may be selected from the group consisting of 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,
The solvent is at least one selected from diethyl ether, dipropyl ether, dibutyl ether, benzene, toluene and xylene,
The co-solvent is at least one selected from kerosene and dimethyl carbonate,
A silica film is prepared from the polysilazane by heat treatment, a surfactant, a solvent, and a cosolvent are removed to form a plurality of pores in the silica film,
Wherein the pores formed in the silica film lower the refractive index and reflectance of the film and increase the transmittance.
delete delete delete delete delete delete (a) washing the substrate;
(b) preparing the antireflective coating composition of claim 1;
(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.
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