KR100907357B1 - Method for Producing a Coating Agent for Anti-Glare Coating, and the Coating Agent and Anti-Glare Film - Google Patents

Abstract

A method for producing a coating agent for antireflective coating, a coating agent thereof, and an antireflective film are introduced. In particular, the method for preparing a coating agent includes (A) an organic solvent, a surfactant, and a particle diameter of 2 to 50 nm, and mixed and stirred with a colloidal silica having a concentration of 5 to 40% by weight based on weight to prepare a silica reverse micelle having a pore size of 10 to 100 nm. Generating; (B) surface treating the reverse micelle particles by mixing and stirring a silane derivative to the reverse micelle solution obtained in step (A); And (C) removing at least an organic solvent and a surfactant from the reverse micelle solution obtained in step (B) to prepare silica particles having a pore size of 10 to 100 nm.

Antireflective, Coating, Nanoparticle

Description

Coating for anti-reflective coating, manufacturing method and anti-reflective film {Method for Producing a Coating Agent for Anti-Glare Coating, and the Coating Agent and Anti-Glare Film}

The present invention relates to a coating agent for antireflective coating, a method for producing the same, and an antireflective film using the coating agent.

In recent years, in the field of display devices such as liquid crystal displays (LCDs), organic light emitting diodes (OLEDs), and PDPs, the use of anti-reflective films has been expanded to prevent deterioration of visibility and glare of screens.

Typically, the antireflection film is composed of a transparent substrate, a resin layer for hard-coat (hard-coat) imparting, a low refractive coating layer which is an antireflection film, the low refractive coating layer is dry coating or wet coating.

First, dry coating may be used, such as vacuum deposition, sputtering method, CVC method, such dry coating is excellent in the anti-reflection performance, but there is a disadvantage in the mass production is limited and expensive.

Next, wet coating is a coating of a solution-type low refractive coating (anti-reflective coating) on a film or sheet, which has the advantage of being able to mass produce and inexpensive manufacturing cost compared to dry coating, and many studies have been made recently. . In particular, the anti-reflection performance in the wet coating is highly dependent on the refractive index of the low refractive coating layer to be coated, the research has been actively conducted to improve the antireflection performance of the anti-reflection film by lowering the refractive index of the low refractive coating layer.

Known among these wet coating techniques, there is a method of containing a low refractive index fluorine in the low refractive coating layer. Examples are Korean Patent Publication Nos. 2000-0059818, 2005-0083890, US Patent Nos. 5,74,537, 4,846,650, 6,773,121, and 6,908,647.

However, although the refractive index decreases as the content of the fluorine resin included in the low refractive coating layer increases, the refractive index of the fluorine resin itself is about 1.35 to 1.40, so that the limit of lowering the refractive index by increasing the fluorine content in the low refractive coating layer is limited. In addition, as the content of the fluororesin increases, there is a disadvantage in that the adhesion and coating hardness of the coating layer are reduced.

Another method of lowering the refractive index of the low refractive coating layer is a method of adding particles containing pores to the low refractive index layer. Since the refractive index of the pores is close to 1, the content of the pores included in the low refractive index coating agent is increased to lower the refractive index of the low refractive layer. An example is US Pat. No. 6,777,069. This patent proposes a method for preparing silica particles containing pores by preparing mixed particles of silica and alumina and dissolving alumina in the particles through acid treatment.

However, this method has been successful in preparing silica dispersed particles having pores containing 100 nm or less, but has a disadvantage in that the process is complicated. In addition, since the mixed particles of silica and alumina are prepared through the precursor of silica and alumina in an aqueous solution, the alumina is not completely dissolved when the alumina is dissolved through acid treatment, and the remaining high refractive alumina component adversely affects the transmittance and the refractive index. There is a problem.

The present invention has been proposed to solve the above problems, and does not include a metal component such as alumina that affects the refractive index, silica particles of less than 100nm containing a pore suitable for the low refractive layer, the manufacturing method and such silica particles The purpose is to provide an antireflection film used.

The present invention for achieving the above object, by generating a reverse micelle from the silica surface treatment using a silane derivative so that the pores of the reverse micelles are exposed, thereby providing a pore suitable for a coating for antireflective coating, that is, a low refractive layer Pure silica particles containing 100 nm or less are prepared. Looking at this by specific manufacturing process as follows.

[Process for generating silica reverse micelles]

The key point of this process is to mix and stir colloidal silica with organic solvent, surfactant, particle size of 2-50nm and 5-40% by weight, to produce silica reverse micelles with pore size of 10-100nm. .

As the organic solvent, pentane, hexane, heptane, octane, nonane, benzene, toluene, xylene, 1,2-dichloroethane, chloroform and a mixed solvent of the above solvent may be used, and among these, hexane and heptane solvents. It is suitable in terms of solubility, toxicity and price in water.

As the surfactant, anionic surfactants, cationic surfactants, and nonionic surfactants can be used, but it is preferable to use anionic surfactants and nonionic surfactants having good solubility in organic solvents. In particular, sulfonic acid sodium salt anionic surfactants are not only low in use, but also suitable in terms of solubility in organic solvents and particle size of reverse micelles produced. The amount of the surfactant is preferably about 0.5 to 5 parts by weight based on 100 parts by weight of the organic solvent. If the amount of the surfactant is less than 0.5 parts by weight, it is difficult to form reverse micelle particles having a particle size of 100 nm or less. On the contrary, if the amount is more than 5 parts by weight, the surfactant is not completely dissolved in the solvent.

Colloidal silica is suitable for colloidal silica having a particle size of 2 to 50nm, the concentration of solids is suitable 5 to 40% by weight. If the solid content is less than 5% by weight, the content of pores in the resulting particles is too high, resulting in poor stability and poor surface treatment with silane derivatives. On the other hand, when it exceeds 40 weight%, the pore content of a silica particle becomes remarkably low. In addition, the amount of colloidal silica is suitably 2 to 10 parts by weight based on 100 parts by weight of the organic solvent. If the amount of the colloidal silica is less than 2 parts by weight, the solid content is too low to be practical, and if it exceeds 10 parts by weight, the particles are agglomerated with each other to produce large particles having a particle size of 100 nm or more.

[Process for surface-treating reverse micelle particles]

It is a step of surface treatment of the reverse micelle particles by mixing and stirring the silane derivative in the reverse micelle solution obtained in the reverse micelle production step. For surface coating by silane derivatives, ammonia can be used as an accelerator, and the coating prevents the pores of reverse mice from being exposed to the outside, thereby preventing contaminants from entering the pores and affecting the refractive index. .

As the silane derivative, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, trimethoxymethylsilane, trimethoxyethylsilane, trimethoxypropylsilane, triethoxymethylsilane, triethoxyethylsilane, tri Ethoxypropylsilane, tripropoxymethylsilane, tripropoxyethylsilane, tripropoxypropylsilane, dimethoxydimethylsilane, dimethoxydiethylsilane, dimethoxydipropylsilane, diethoxydimethylsilane, diethoxydiethylsilane , Diethoxy dipropyl silane, dipropoxy dimethyl silane, dipropoxy diethyl silane, dipropoxy dipropyl silane and the like can be used, the amount is appropriately 20 to 300 parts by weight based on 100 parts by weight of the colloidal silica solid content Do. If the amount of the silane derivative is less than 20% by weight of the colloidal silica solids, the prepared reverse micelle particles may not be effectively surface treated, and if the amount of the silane derivative exceeds 300%, too much silane may bind to the reverse micelle particle surface. As the percentage of pores contained in the particles is reduced, the refractive index reduction effect is lowered.

[Removal process of organic solvent, surfactant, etc.]

Removing the organic solvent, surfactant, and the like (including various foreign matters included in the process) from the reverse micelle solution obtained in the reverse micelle particle surface treatment step, to prepare pure silica particles having a pore size of 10 ~ 100nm having pores.

This process can be carried out in two ways.

Firstly, silica particles are separated from the reverse micelle solution obtained in the reverse micelle particle surface treatment step, and then dispersed in water or alcohol after washing, and the solution is filtered and concentrated to give a silica concentration of 1 to 10% by weight. It is to obtain a particle solution.

Secondly, the reverse micelle solution obtained in the reverse micelle particle surface treatment step is dispersed in alcohol, and then the silica dispersion is filtered and concentrated to obtain a silica particle solution having a concentration of 1 to 10% by weight.

If the concentration of the silica particle solution is thin, the coating may be thick.However, if the concentration is less than 1% by weight, it is too thin to reduce the productivity and coating uniformity. If it exceeds 10% by weight, the concentration of the coating layer is too high. Thickness control is not easy.

[Application of anti-reflective coating agent]

Silica particles prepared as described above do not contain metal salts such as alumina, and exhibit high transmittance and low cloudiness, and excellent antireflection effect when coated on a film or sheet.

Silica particles may be used alone or may be mixed with a UV cured paint or a thermosetting paint. As one example, the UV curable paint may be a mixed paint of a polyfunctional acrylic oligomer and a photoinitiator, and the thermosetting paint may be a sol solution obtained by treating tetraethoxysilane with nitric acid.

Hereinafter, a specific embodiment will be described.

Example  One

15 L (about 9.905 kg) of n-hexane was added to the reactor, and 257 g of dodecyl succinate sulfonic acid sodium salt was added as a surfactant and dissolved. 495 g of an aqueous colloidal silica solution having a solid concentration of 15 wt% was added thereto, followed by stirring for 4 hours to prepare reverse micelle particles. Then, 58.5 g of triethoxymethylsilane was added to the reactor as a silane derivative, followed by further stirring for 20 hours.

Thereafter, 1% by weight of ammonia water was added to the reactor, and further stirred for 3 hours, and then 600 g of acetone was added to form a precipitate. The precipitate was centrifuged to separate solids and then washed twice with acetone. Then, 6 kg of distilled water was added to the precipitate, and the precipitated particles were dispersed using ultrasonic waves.

Next, the dispersed particles were filtered using a filter having a particle diameter of 0.2 μm, and the filtrate was concentrated to prepare 1.2 kg of a silica particle solution of 100 nm or less containing pores at a concentration of 5% by weight. The average particle diameter of the prepared silica particles was 14 nm.

The prepared silica particle solution containing pores of 100 nm or less was spin-coated on a 1 mm thick glass plate, dried at 200 ° C. for 10 minutes to form an antireflection layer having a thickness of 100 nm, and then the physical properties thereof were shown in Table 1 below. .

Example  2

In the same manner as in Example 1, 1.2 kg of a silica particle solution of 100 nm or less containing pores at a concentration of 5% by weight was prepared. However, unlike Example 1, 214.5 g of a dododecyl succinate sulfonic acid sodium salt as a surfactant was added thereto, and the average particle diameter of the silica particles thus prepared was 14 nm.

The prepared silica particle solution, as in Example 1, was spin-coated on a 1 mm thick glass plate, dried at 200 ° C. for 10 minutes to form an antireflection layer having a thickness of 100 nm, and then measured by physical properties.

Example  3

15 L (about 9.905 kg) of n-hexane was added to the reactor, and 257 g of dodecyl succinate sulfonic acid sodium salt was added as a surfactant and dissolved. 495 g of an aqueous colloidal silica solution having a solid concentration of 15 wt% was added thereto, followed by stirring for 4 hours to prepare reverse micelle particles. Then, 58.5 g of triethoxymethylsilane was added to the reactor as a silane derivative, followed by further stirring for 20 hours. Then, 1% by weight of ammonia water was added to the reactor by weight, and further stirred for 3 hours. This process is the same as in Example 1 above.

Next, the ammonia water addition and stirring completed silica solution was added slowly and disperse | distributed to 10 kg of hexane and ethylhexyl alcohol. The dispersed hexane and ethylhexyl alcohol mixed solvents were ultrafiltered to remove the hexane solvent and the surfactant, and concentrated to prepare 0.3 kg of a silica particle solution of 100 nm or less containing pores at a concentration of 2% by weight. The average particle diameter of the prepared silica particles was 25 nm. The amount of material charged was the same as in Example 2, but the average particle diameter of the prepared silica particles was slightly increased than in the case of Example 2.

The prepared silica particle solution was spin coated on a 1 mm thick glass plate, dried at 200 ° C. for 10 minutes to form an antireflection layer having a thickness of 100 nm, and then measured by physical properties.

Example  4

After mixing the silica particle solution prepared in Examples 1 to 3 with the thermosetting paint 1: 1 by weight, spin-coated on a 1 mm thick glass plate and dried at 200 ° C. for 10 minutes to form an antireflection layer having a thickness of 100 nm. After the measurement, the physical properties are shown in Table 1. Examples corresponding to Examples 1 to 3 are represented by 4-1, 4-2, and 4-3, respectively.

The thermosetting paint was prepared by the following method.

117 g of triethoxymethylsilane was added to 177 g of ethanol, and 81 g of 0.1 N nitric acid aqueous solution was added, followed by stirring for 24 hours. 410 g of ethanol was further added to prepare a thermosetting paint having a concentration of 5% by weight of solids.

Comparative example  One

The colloidal silica used in Example 1 was spin coated alone on a 1 mm thick glass plate, dried at 200 ° C. for 10 minutes to form an antireflection layer having a thickness of 100 nm, and then measured by physical properties.

Comparative example  2

The thermosetting paint prepared in Example 4 was spin coated alone on a glass plate having a thickness of 1 mm, dried at 200 ° C. for 10 minutes to form an antireflection layer having a thickness of 100 nm, and the physical properties thereof were shown in Table 1 below.

division Example 1 Example 2 Example 3 Example 4-1 Example 4-2 Example 4-3 Comparative Example 1 Comparative Example 2 Cloudy road 0.2 0.2 0.2 0.1 0.1 0.1 0.2 0.1 Pencil hardness - - - 4H 4H 4H - 4H Reflectance (%) 1.35 0.25 0.25 1.9 1.0 1.0 3.5 2.5 Refractive index 1.39 1.30 1.30 1.42 1.37 1.37 1.50 1.45

As can be seen from Table 1 above, the coating layer prepared using silica particles of 100 nm or less containing pores prepared in Example, showed very excellent results in cloudyness and minimum reflectance compared to Comparative Examples 1 and 2. It can be seen that.

According to the manufacturing method as described above, a metal component such as alumina is not interposed, and it is possible to prepare a coating for antireflective coating containing pores and having a size of 100 nm or less.

In addition, the antireflection film to which the prepared coating agent is applied exhibits high transmittance, low cloudiness, and excellent antireflection effect.

Claims (8)

(A) mixing and stirring an organic solvent, a surfactant, and a colloidal silica having a particle size of 2 to 50 nm and a concentration of 5 to 40% by weight, to produce silica reverse micelles having a pore size of 10 to 100 nm; (B) surface treating the reverse micelle particles by mixing and stirring a silane derivative to the reverse micelle solution obtained in step (A); And (C) removing at least an organic solvent and a surfactant from the reverse micelle solution obtained in step (B) to prepare silica particles having a pore size of 10 to 100 nm with pores; Step (C) is, (a) separating the silica particles from the reverse micelle solution obtained in step (B), and (b) dispersing the silica particles obtained in step (a) in water or alcohol after washing, (c) filtering and concentrating the solution obtained in the step (b) to obtain a silica particle solution having a concentration of 1 to 10% by weight. 2. (A) mixing and stirring an organic solvent, a surfactant, and a colloidal silica having a particle size of 2 to 50 nm and a concentration of 5 to 40% by weight, to produce silica reverse micelles having a pore size of 10 to 100 nm; (B) surface treating the reverse micelle particles by mixing and stirring a silane derivative to the reverse micelle solution obtained in step (A); And (C) removing at least an organic solvent and a surfactant from the reverse micelle solution obtained in step (B) to prepare silica particles having a pore size of 10 to 100 nm with pores; Step (C) is, (a) dispersing the reverse micelle solution obtained in step (B) in alcohol, (b) filtering and concentrating the silica dispersion obtained in the step (a) to obtain a silica particle solution having a concentration of 1 to 10% by weight; and a method for manufacturing a coating for antireflective coating, characterized in that it comprises a. The method of claim 1 or 2, wherein the colloidal silica used in step (A) is used in an amount of 2 to 10 parts by weight based on 100 parts by weight of an organic solvent. The method according to claim 3, wherein the surfactant used in the step (A), 0.5 to 5 parts by weight based on 100 parts by weight of the organic solvent, characterized in that the anti-reflective coating coating production method. The method of claim 4, wherein the silane derivative used in the step (B) is used in an anti-reflective coating, characterized in that 20 to 300 parts by weight based on 100 parts by weight of the solid content of colloidal silica. The method of claim 5, wherein the hexane or heptane solvent is used as the organic solvent in the step (A). Coating agent for anti-reflective coating, characterized in that the silica particle solution prepared by the manufacturing method according to claim 1 or 2. An anti-reflection film used to reduce the surface reflection of various displays, characterized in that the coating agent prepared according to claim 7 is coated.