KR101445437B1 - Anti-Reflection Film and Method of Producing The Same - Google Patents

Abstract

The present invention relates to a base substrate, A high refractive index layer disposed on the base substrate and including nanoparticles surface-modified with an acrylic polymer having a diameter of 1 to 50 nm; And a low refraction layer formed on the high refraction layer and including nanoparticles having a diameter of 50 to 1000 nm.
The antireflection film of the present invention is advantageous in that the nanoparticles are prepared by an environmentally-friendly sol-gel process and the coating is performed using a simple wet process, thereby eco-friendliness of the process and simplification of the process.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an antireflection film,

The present invention relates to an antireflection film applied to a display and a method of manufacturing the same.

The anti-reflection (AR) film is placed on the outermost base film constituting the polarizing film of the display panel, and is deteriorated in visibility due to surface reflection caused by an external light source such as sunlight or indoor light or an internal light source. And it is the core material of the display with antifouling property and durability. Recently, as the display has advanced and the demand for the quality of the consumer has increased, the display quality and the high quality of the display have become an essential factor of high value-added. Therefore, the demand for the anti-reflection film is rapidly increasing.

Conventional antireflection film products are mainly composed of a multi-layer structure, which can realize a reflectance of about 1%, and thus exhibits a relatively low reflectance as compared with a single layer. However, since the process is complicated and the price is high, It is pointed out as a problem. In addition, since most of the wet process uses a volatile organic compound (VOC) such as methyl ethyl ketone, the possibility of environmental pollution is high, and in the case of a sputtering process, .

Accordingly, the present invention provides an antireflection film produced by an eco-friendly process and having excellent effects and a method for producing the same.

In order to solve the above problems, the present invention provides a semiconductor device comprising: a base substrate; A high refractive index layer disposed on the base substrate and including nanoparticles surface-modified with an acrylic polymer having a diameter of 1 to 50 nm; And a low refraction layer formed on the high refraction layer and including nanoparticles having a diameter of 50 to 1000 nm.

According to the present invention, nanoparticles are produced by an environmentally-friendly sol-gel process in the production of an antireflection film and coating is performed using a simple wet process, which has advantages such as eco-friendliness of the process and simplification of the process.

1 is an antireflection film structure of the present invention.
2 is a TEM photograph (a) of a nanoparticle and a TEM photograph (b) of a porous nanoparticle.
3 is a graph showing the particle size (a) of the nanoparticles measured by the light scattering method and the particle size (b) of the porous nanoparticles.
4 is a graph of reflectance of anti-reflection films of various structures measured with a spectrophotometer.

The details of other embodiments are included in the detailed description and drawings. Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic view showing an antireflection film according to the present invention.

The antireflection film of the present invention comprises a base substrate 1; A high refractive index layer disposed on the base substrate and comprising nanoparticles (2) surface-modified with an acrylic polymer (4) having a diameter of 1 to 50 nm; And a low refraction layer formed on the high refractive index layer and including nanoparticles (3) having a diameter of 50 to 1000 nm.

The base substrate 1 may be one selected from the group consisting of a polyethylene (PE) film, a polyethylene terephthalate (PET) film, a triacetylcellulose (TAC) film and a glass substrate, .

The nanoparticles 2 and 3 may be one selected from the group consisting of indium oxide, silicon dioxide, zirconium oxide, titanium dioxide, sodium fluoride, and magnesium fluoride, preferably silicon dioxide.

More specifically, the nanoparticles of the low refraction layer may be porous silica.

In one embodiment of the present invention, the nanoparticles of the high refractive index layer are surface-modified with an acrylic polymer, and when the acrylic polymer is added to the nanoparticles prepared by the sol-gel process, the surface of the nanoparticles is modified .

When silica nanoparticles are used as the nanoparticles in the preparation of the coating solution prepared for the high refractive index layer, the silica nanoparticles are synthesized from tetraalkoxysilane (Si (OR)) as a precursor by using a sol- ₄ , wherein R is an alkyl group having 1 to 2 carbon atoms) can be obtained in the form of a dispersion solution of particles having a size of several nanometers (1-50 nm) in a clear solution by conducting a condensation reaction with a hydrolysis reaction. In order to realize both the antireflection and functionality desired in the present invention, the silica nanoparticles for the high-refraction layer are suitably several nanometers in size, and particles of this size can form a dense film while maintaining high transparency to be.

If the size of the generated particles is too large (for example, 100 nm or more), transparency may be lowered. (CH ₂ ═CHCOO (CH ₂ ) _n Si (OR) ₃ wherein n is an integer of 1 to 10, and R is an organic group having 1 to 2 carbon atoms, which has an acrylic group on the surface of the nanoparticles prepared for the high- Alkyl group) resin is chemically bonded by a sol-gel reaction, and a crosslinking agent and a photoinitiator are mixed together in the dispersion solution, so that UV curing can be performed well. Typical acrylic resin photoinitiators and cross-linking agents can be used for photoinitiator and cross-linking reactions. By way of example, 2-hydroxy-2-methylpropiophenone and dipentaerythritol hexaacrylate can be used.

As the nanoparticles of the low refraction layer, porous silica particles having a diameter of 50 to 1000 nm can be used, which can be produced by using a self-assembly of a suitable surfactant as a template under a basic catalyst. (NH ₂ (CH ₂ ) n Si (OR) ₃ ) as a minor precursor and tetraalkoxysilane (Si (OR) ₄ , where R is an alkyl group having 1 to 2 carbon atoms) as a main precursor and aminoalkyltrialkoxysilane n is 1 to 10, and R is an alkyl group having 1 to 2 carbon atoms).

In order to coat the high refractive index layer on the base film or the support, the base film or the support may be surface-treated in an appropriate manner so that wetting of the coating solution occurs well and adhesion is improved. For example, in the case of a glass support, a solution prepared by mixing hydrogen peroxide and sulfuric acid in an appropriate ratio is subjected to an oxidation process to remove impurities on the surface of the glass support and to form a silanol functional group on the surface.

The coating solution may be spin coated on the surface-treated base film or the support. In this case, the evaporation rate of the coating solution is affected by the temperature and the humidity. In order to obtain a uniform surface coating, Is very important. The speed of the spin coater can generally be divided into two stages. In the first stage, the speed of the spin coater is influenced by the centrifugal force of the spin coater, so that the coating solution is expanded to the front of the glass support. A step that influences the evaporation of the coating solution is to create a uniform surface. More specifically, the coating conditions of the first step can be carried out at 2000 to 5000 rpm for 10 to 60 seconds, and the second step can be carried out at 4000 to 8000 rpm for 1 to 20 seconds. After spin coating, the film is dried in an oven at a constant temperature ranging from 50 ° C to 90 ° C, cured using a UV lamp, and heated at a temperature in the range of 150 ° C to 400 ° C so that the film coated on the support is thermodynamically stable, The coating film can be well maintained.

For the coating of the low refraction layer, a method of dip coating the nanoparticle dispersion can be used. Since the coating speed may be important during dip coating, the coating is carried out at a constant rate, and the coating is carried out by immersing the anionic polymer or the cationic polymer and the porous silica particles for a predetermined time so that the porous silica particles are sufficiently coated. First, a substrate coated with a low refractive index layer is immersed in a solution of a cationic polymer for 5 to 20 minutes and then taken out at a constant rate of 0.5 to 2.5 cm / min. After coating, the polymer solution is washed again with an anionic polymer solution Coating, and the desired number of cation / anionic polymer layers can be coated by alternately performing this process. The substrate coated with the cationic polymer in the outermost layer may be immersed in the porous silica particle coating solution to perform the coating in the same manner as the above-mentioned method. After the dip coating, it can be thermodynamically stable while being dried at a constant temperature of 300 to 700 ° C for 2 to 5 hours.

[Example]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail with reference to the following examples. However, the following examples are intended to illustrate the contents of the present invention, but the scope of the present invention is not limited to the following examples. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art.

< Example  1>

An antireflection film having a two-layer structure of a high refractive index layer / a low refractive layer was prepared using a glass substrate (radius: 1 inch, thickness: 0.2 mm) as a support. The glass support was immersed in a mixed solution of hydrogen peroxide and sulfuric acid for a certain period of time to remove the impurities on the surface of the support and subjected to surface treatment. The surface-treated organic substrate was immersed in distilled water for a certain period of time and then dried.

30 to 60 parts by weight of a precursor tetraalkoxysilane (Si (OR) ₄ , where R is an alkyl group having 1 to 2 carbon atoms) and 20 to 40 parts by weight of an alkoxysilane (CH ₂ = CHCOO (CH ₂ ) _n Si (OR) ₃ wherein n is an integer of 1 to 10, and R is an alkyl group having 1 to 2 carbon atoms) and stirred at a speed of 200-800 rpm to obtain a homogeneous solution Followed by adding 15 to 25 parts by weight of distilled water having pH 1-3 as an acid catalyst. The coating solution was then stirred at 200-800 rpm for 2-8 hours. After the stirring was completed, the coating solution was centrifuged at a speed of 2000-4000 rpm for 2-10 minutes to obtain a uniform coating solution.

 The photoinitiator and cross-linking agent were added to the resulting anti-radiation coating solution to perform surface modification on the nanoparticles. 1 to 8 占 퐇 of the high-refractive-index layer coating solution was dropped on the surface-treated glass substrate and spin-coated under the above conditions. The spin-coated high-refraction layer was dried under the above conditions, and then the coating film was cured using a UV lamp. The cured coating film increased its stability while heating under the above conditions.

60 to 90 parts by weight of distilled water, 10 to 20 parts by weight of ethylene glycol, 1 to 10 parts by weight of ammonia water and 0.2 to 5 parts by weight of cetyltrimethylammonium bromide were added and stirred for 10 minutes to 1 hour under the above conditions. Then, 0.1 to 5 parts by weight of a main precursor and 0.1 to 5 parts by weight of an additional precursor were added, and the mixture was further stirred at the same temperature for 2 to 4 hours. After stirring, the mixture was allowed to stand at 40-80 ° C for 6-24 hours to allow all unreacted reactants to react. 10 to 25 parts by weight of polyallylamine hydrochloride as a cationic polymer, and 70 to 90 parts by weight of distilled water at pH 2-4 were added to prepare a coating solution. Sodium hydroxide (Sigma-Aldrich) was added to the solution in which the porous silica particles were dispersed so that the pH was 8-10.

Dip coating was carried out using a dip coater. The glass support coated with the high refractive index layer is immersed in a solution of the polyallylamine hydrochloride polymer dispersed at a rate of 20 mm / min, allowed to stand for 15 minutes, and taken out at the same speed as that of the soaking. After the two washing steps, the coating solution in which the porous silica particles were dispersed was coated by the same method as the coating method of the polymer material, and the coating solution was dried under the above conditions after the coating.

< Example  2>

The coating was performed in the same manner as in Example 1, but the low refraction layer coating process was repeated twice.

< Example  3>

The coating was performed in the same manner as in Example 1, but the low refraction layer formation process was performed three times.

< Comparative Example  1>

Only the glass substrate surface-treated as in Example 1 was used.

< Comparative Example  2>

In Example 1, only the high refractive index layer formation process was completed.

< Test Example  1> Surface analysis

To confirm the nanoparticles of the resulting coating solution, nanoparticles were identified by transmission electron microscopy (JEM-300F, JEOL), and a particle size analyzer (BI-9000AT / 200SM, Brookhaven, USA). The results are shown in Figures 2 and 3, respectively.

< Test Example  2> Reflectance test

The reflectance of the entire film was measured using a spectrophotometer (Lambda 35, Perkin Elmer) after the antireflective film was prepared by the methods shown in Examples and Comparative Examples, and the results are shown in Table 1 below.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Low reflectance (%) 6.44 6.01 6.04 8.31 7.37

The reflectance graph of each example is shown in Fig.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. will be. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

1: Base substrate
2: High-refraction layer (surface-modified nanoparticles)
3: low refraction layer (porous silica particle)
4: Organic material for UV curing

Claims (3)

Preparing a coating solution containing surface-modified silica nanoparticles by adding an acrylic polymer to silica nanoparticles having a diameter of 1 to 50 nm;
Spin-coating a coating solution containing the surface-modified silica nanoparticles on a base substrate to form a high-refraction layer;
Preparing an anionic polymer solution in which a cationic polymer solution and porous silica particles having a diameter of 50 to 200 nm are dispersed; And
The base substrate on which the high refractive index layer is formed is alternately immersed in the cationic polymer solution and the anionic polymer solution in which the porous silica particles are dispersed and dip coated to form a low refraction layer on the high refractive index layer;
Lt; / RTI &gt;
The spin coating is performed in two steps, the first step being performed at a spin coating speed of 2000-5000 rpm for 10-60 seconds, the second step being performed at a spin coating speed of 4000-8000 rpm for 1-20 seconds;
Wherein the dip coating is performed by immersing the base substrate on which the high refractive index layer is formed in a cationic polymer solution and an anionic polymer solution for 5 to 20 minutes at a constant rate of 0.5 to 2.5 cm / &Lt; / RTI &gt;
The method according to claim 1,
Wherein the base substrate is one selected from the group consisting of a polyethylene film, a polyethylene terephthalate film, a triacetylcellulose film, and a glass substrate.

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