KR102267506B1 - Manufacturing method of optical member comprising low-refraction silica coating layer and optical member menufactured by the same - Google Patents

Abstract

The present specification relates to a method of manufacturing an optical member including a low refractive silica coating layer.

Description

Manufacturing method of an optical member including a low-refractive silica coating layer, and an optical member manufactured using the same

The present specification relates to a method of manufacturing an optical member including a low refractive silica coating layer and an optical member manufactured using the same.

In recent years, the display market is rapidly growing not only for TVs, monitors, and laptop panels, which are traditional consumers, but also for mobile devices represented by smartphones and automobile dashboards. Among the continuously developing display technologies, one of the specifications that greatly affects customer satisfaction is the reflectance of the surface. In the case of a film introduced to the outermost part of the display, it generally has a reflectance of about 4% due to Fresnel reflection, and such a high reflectance adversely affects the visibility of the display in an environment exposed to daylight and illumination light. To solve this, coatings such as AG (anti-glare) or AR (anti-reflection) are being introduced, but in the case of AG coating, not only reflected light but also light emitted from the display is dispersed, so there is a problem of poor visibility, and AR coating is Since it is manufactured through a deposition process, it has a disadvantage that it is difficult to enlarge it and the unit cost is high.

Accordingly, it is necessary to develop a coating layer that has a low reflectance and can be produced at a low price.

Korean Publication: KR 10-2011-0112222 A

The present specification provides a method of manufacturing an optical member including a low-refractive silica coating layer and an optical member manufactured using the same.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

An exemplary embodiment of the present invention comprises the steps of preparing a silica precursor dispersion comprising a solvent and an alkoxy silane; adding an acidic catalyst to the silica precursor dispersion to form a silica precursor sol solution comprising a silica precursor sol; mixing the silica precursor sol solution and hollow silica particles; applying a silica precursor sol solution including the hollow silica particles on a substrate; drying the silica precursor sol solution applied on the substrate to form a silica precursor sol layer; and contacting the silica precursor sol layer with a base catalyst to form the silica precursor sol layer as a low refractive silica coating layer;

All of the above processes provide a method of manufacturing an optical member including a low-refractive silica coating layer that is performed in an atmosphere of 120° C. or less.

An exemplary embodiment of the present invention provides an optical member including a low-refractive silica coating layer prepared by the above manufacturing method.

The manufacturing method according to an exemplary embodiment of the present invention can manufacture an optical member including a low-refractive silica coating layer having excellent performance in a simple and inexpensive method.

The manufacturing method according to an exemplary embodiment of the present invention has the advantage of not requiring a high-temperature heat treatment process using only a simple chemical treatment.

Since the manufacturing method according to an exemplary embodiment of the present invention is performed at a low temperature, there is an advantage in that an optical member having a low refractive index coating layer formed directly on a polymer substrate can be manufactured.

Since the manufacturing method according to an exemplary embodiment of the present invention is performed through a coating process, there is an advantage that mass production is possible using a roll-to-roll continuous process. In addition, the manufacturing method according to an exemplary embodiment of the present invention does not use a high-temperature firing process, and since all processes are performed in an atmosphere of 120° C. or less, a flexible polymer substrate may be applied to perform a roll-to-roll continuous process.

Throughout this specification, when a member is said to be located “on” another member, this includes not only a case in which a member is in contact with another member but also a case in which another member is present between the two members.

Throughout this specification, when a part "includes" a component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

Throughout this specification, reference to “A and/or B” means “A or B, or A and B”.

The term “step of” or “step of” to the extent used throughout this specification does not mean “step for”.

In the present specification, the unit “parts by weight” may mean a ratio of weight between each component.

In the present specification, the size of the particles may be measured through a particle size analyzer. Furthermore, by using optical equipment, it is possible to observe the particles and check whether the results measured through the particle size analyzer are correct.

The present inventors have found that, when preparing a low-refractive coating layer using hollow silica nanoparticles and a binder resin, a large amount of hollow silica nanoparticles must be contained in order to achieve sufficient low-refractive properties, so that when testing physical properties, the hollow silica nanoparticles fall out of the coating layer There was a problem that it was difficult to secure the physical properties of the coating layer itself due to the excessive content of hollow silica particles compared to the polymer matrix. Furthermore, when an inorganic low refractive index layer is manufactured to improve mechanical properties, it is difficult to form a low refractive index coating layer directly on a polymer substrate due to a high-temperature firing process, or an expensive laser or electron beam irradiation device, vapor deposition device, etc. are used. Recognizing the problem of excessively increasing the manufacturing cost, in order to solve the problem, the present invention was developed.

Specifically, according to the present invention, a low-refractive silica coating layer including hollow silica particles can be prepared by simple chemical treatment without a high-temperature sintering process. Furthermore, since the matrix constituting the low-refractive silica coating layer is a silica matrix of the same type as the hollow silica particles, the bonding strength between the hollow silica particles and the matrix is excellent, and thus the separation of the hollow silica particles can be minimized. Furthermore, since the present invention can form a low-refractive silica coating layer only by chemical treatment without a high-temperature sintering process, there is a great advantage in being able to directly form a low-refractive silica coating layer on a polymer substrate.

Hereinafter, the present specification will be described in more detail.

An exemplary embodiment of the present invention comprises the steps of preparing a silica precursor dispersion comprising a solvent and an alkoxy silane; adding an acidic catalyst to the silica precursor dispersion to form a silica precursor sol solution comprising a silica precursor sol; mixing the silica precursor sol solution and hollow silica particles; applying a silica precursor sol solution including the hollow silica particles on a substrate; drying the silica precursor sol solution applied on the substrate to form a silica precursor sol layer; and contacting the silica precursor sol layer with a base catalyst to form the silica precursor sol layer as a low refractive silica coating layer;

All of the above processes provide a method of manufacturing an optical member including a low-refractive silica coating layer that is performed in an atmosphere of 120° C. or less.

Preparing a silica precursor dispersion

According to an exemplary embodiment of the present invention, the method of manufacturing an optical member including the low refractive silica coating layer includes preparing a silica precursor dispersion solution including a solvent and an alkoxy silane.

According to an exemplary embodiment of the present invention, the alkoxy group of the alkoxy silane may be an alkoxy group having 1 to 10 carbon atoms or less. Specifically, according to an exemplary embodiment of the present invention, the alkoxy silane is tetraethoxysilane (TEOS), tetramethoxysilane (TMOS), methoxyethoxysilane (MTEOS), methyltrimethoxysilane (MTMS) , methyltriethoxysilane (MTES), trimethoxyphenylsilane (TMPS), triethoxyphenylsilane (TEPS), 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxy Propyltrimethoxysilane, vinyltrimethoxysilane, 3-(acryloyloxy)propyltrimethoxysilane, 1,2-bis(triethoxysilane)ethane, and 3-methacryloxypropyltrimethoxysilane may include at least one of More specifically, according to an exemplary embodiment of the present invention, the alkoxy silane may be tetraethoxysilane (TEOS).

According to an exemplary embodiment of the present invention, the solvent may include an organic solvent. Specifically, according to an exemplary embodiment of the present invention, the organic solvent may include an organic solvent having a boiling point of 50 °C to 150 °C. Specifically, according to an exemplary embodiment of the present invention, the solvent may include water and an organic solvent.

According to an exemplary embodiment of the present invention, the solvent is an alcohol-based solvent; ketone solvents; and an organic solvent including at least one of an acetate-based solvent.

According to an exemplary embodiment of the present invention, the alcohol-based solvent may include at least one of ethyl alcohol, n-propyl alcohol, i-propyl alcohol, i-butyl alcohol, n-butyl alcohol and t-butyl alcohol.

According to an exemplary embodiment of the present invention, the ketone-based solvent may include at least one of acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethyl ketone, methyl isopropyl ketone, and acetylacetone.

According to an exemplary embodiment of the present invention, the acetate-based solvent may include at least one of methyl acetate, ethyl acetate, propyl acetate, and butyl acetate.

The organic solvent may improve the stability of the silica precursor sol. Furthermore, the content of the organic solvent may be included in the silica precursor dispersion in the number of moles 2 to 8 times the number of moles of the alkoxy silane.

According to an exemplary embodiment of the present invention, the solvent may be a mixed solvent of water and an organic solvent. Specifically, the solvent may be a mixed solvent of water and an alcohol-based solvent.

According to an exemplary embodiment of the present invention, the silica precursor dispersion may further include nanoparticles including at least one of silica, ceria, titania, and zirconia, if necessary.

According to an exemplary embodiment of the present invention, the silica precursor dispersion may further include a fluorine-based slip agent and/or a silicone-based slip agent, if necessary.

According to an exemplary embodiment of the present invention, the silica precursor dispersion may further include a drying retardant if necessary.

forming a silica precursor sol solution;

According to an exemplary embodiment of the present invention, the method for manufacturing an optical member including the low refractive silica coating layer includes the step of adding an acidic catalyst to the silica precursor dispersion to form a silica precursor sol solution including the silica precursor sol do.

According to an exemplary embodiment of the present invention, the forming of the silica precursor sol may include adjusting the pH of the silica precursor dispersion to 0 to 5. Specifically, by adjusting the pH of the silica precursor dispersion to 0 to 5, a silica precursor sol may be formed.

Specifically, the acid catalyst may adjust the pH of the silica precursor dispersion to solize the silica precursor including the alkoxy silane included in the silica precursor dispersion.

According to an exemplary embodiment of the present invention, the acid catalyst may include at least one of hydrochloric acid, sulfuric acid, fluorosulfuric acid, nitric acid, phosphoric acid, acetic acid, hexafluorophosphoric acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid.

The content of the acid catalyst may be added by appropriately adjusting the pH of the silica precursor dispersion to be 0 to 5.

According to an exemplary embodiment of the present invention, the acid catalyst may hydrolyze the silica precursor to form a silica precursor sol represented by the following general formula (1).

[General formula 1]

In Formula 1, n is a plurality of integers, and since the value of n may change depending on time, temperature, humidity, etc. after the silica precursor sol is made, the value of n may change. For example, the value of n in Formula 1 may be an integer of 2 to 10 million or less.

According to an exemplary embodiment of the present invention, the step of forming the silica precursor sol may be performed at a temperature of 80° C. or less. Specifically, the step of forming the silica precursor sol may be performed at room temperature (25 ℃) to 80 ℃ or less.

According to an exemplary embodiment of the present invention, the content of the silica precursor sol in the silica precursor sol solution may be 5 wt% or more and 40 wt%. Specifically, the content of the silica precursor sol in the silica precursor sol solution may be 8 wt% or more and 20 wt% or less, or 10 wt% or more and 15 wt% or less.

In the present specification, the content of the silica precursor sol is the content of the silica precursor sol in the solution through the remaining solids after drying the silica precursor sol solution at 80 ° C. for 1 hour and then dehydrating the silica precursor sol solution at 200 ° C. for 24 hours. can be measured, and the content of the silica precursor sol in the solution can be calculated by calculating the amount of the silica precursor contained in the silica precursor sol solution reacting 100% to sol.

When the content of the silica precursor sol in the silica precursor sol solution is within the above range, the viscosity of the silica precursor sol solution may be appropriately adjusted to facilitate handling during coating. Furthermore, when the content of the silica precursor sol in the silica precursor sol solution is within the above range, it is possible to reduce the drying time after application of the silica precursor sol solution to prevent staining that may occur in the low refractive silica coating layer, The thickness of the refractive silica coating layer may be uniformly implemented.

mixing the silica precursor sol solution and hollow silica particles

According to an exemplary embodiment of the present invention, the method of manufacturing an optical member including the low refractive silica coating layer includes mixing the silica precursor sol solution and the hollow silica particles.

According to an exemplary embodiment of the present invention, the hollow silica particles may be prepared as a hollow silica dispersion in which the hollow silica particles are dispersed in a solvent, and mixed with the silica precursor sol solution.

According to an exemplary embodiment of the present invention, the solvent of the hollow silica dispersion may be the same as the organic solvent described above. Specifically, the hollow silica dispersion may be one in which hollow silica particles are dispersed in an alcohol-based solvent.

According to an exemplary embodiment of the present invention, the average outer diameter of the hollow silica particles may be 20 nm or more and 100 nm or less. Specifically, the average outer diameter of the hollow silica particles may be 20 nm or more and 70 nm or less, 40 nm or more and 70 nm or less, or 30 nm or more and 60 nm or less.

According to an exemplary embodiment of the present invention, the thickness of the shell portion of the hollow silica particles may be 5 nm or more and 15 nm or less, or 5 nm or more and 10 nm or less.

The shell portion of the hollow silica particles may be measured as a difference between the outer diameter and the hollow particle diameter of the hollow silica particles.

When the average outer diameter of the hollow silica particles is within the above range, they may be well dispersed in the low refractive silica coating layer. In addition, when the thickness of the shell portion of the hollow silica particles is within the above range, it is possible to prevent the refractive index of the hollow silica particles from becoming too high, and to secure the strength of the hollow silica particles. Through this, the low refractive silica coating layer can optimize physical strength and optical refractive index.

According to an exemplary embodiment of the present invention, the weight ratio of the silica precursor sol and the hollow silica particles in the silica precursor sol solution may be 8:2 to 2:8. Specifically, the weight ratio of the silica precursor sol and the hollow silica particles in the silica precursor sol solution may be 7:3 to 5:5 or 7:3 to 6:4.

When the weight ratio of the silica precursor sol and the hollow silica particles is within the above range, the surface strength of the low-refractive silica coating layer is maintained at an appropriate level, and low light reflectance can be realized, and thus low light reflectance of the optical member is realized. can be

According to an exemplary embodiment of the present invention, the total content of the silica precursor sol and the hollow silica particles in the silica precursor sol solution may be 1 wt% or more and 15 wt% or less. Specifically, the total content of the silica precursor sol and the hollow silica particles in the silica precursor sol solution may be 1 wt% or more and 13 wt% or less, 4 wt% or more and 13 wt% or less, or 5 wt% or more and 12 wt% or less.

When the total content of the silica precursor sol and the hollow silica particles in the silica precursor sol solution is within the above range, the viscosity of the silica precursor sol solution may be appropriately adjusted to facilitate handling during coating. Furthermore, when the total content of the silica precursor sol and the hollow silica particles in the silica precursor sol solution is within the above range, the drying time after application of the silica precursor sol solution is shortened to prevent stains that may occur in the low refractive silica coating layer. and the thickness of the low-refractive silica coating layer may be uniformly implemented.

A silica precursor sol solution containing hollow silica particles on the substrate step of applying

According to an exemplary embodiment of the present invention, the method of manufacturing an optical member including the low refractive silica coating layer includes applying a silica precursor sol solution including the hollow silica particles on a substrate.

The silica precursor sol solution may be applied without limitation by a coating method generally known in the art, such as bar coating or spin coating.

According to an exemplary embodiment of the present invention, the substrate may be an optical film provided with the low refractive silica coating layer. Specifically, the substrate may be a polarizing film, a brightness enhancing film, or a retardation film. In addition, the substrate may be a display panel or a touch panel.

According to an exemplary embodiment of the present invention, the substrate may be an optical film having at least one functional layer of a high refractive index layer, a hard coating layer, and an antireflection layer on one surface. Specifically, the low refractive silica coating layer may be formed on the functional layer of the substrate.

Since the method for manufacturing an optical member including a low refractive silica coating layer according to the present invention does not undergo a high-temperature firing process, the substrate may be an optical film, not a liner that is separated from the coating layer after forming the coating layer, specifically, It may be a polymer substrate for a display, such as a polarizing plate.

Further, according to an exemplary embodiment of the present invention, the substrate may be a polymer substrate. Specifically, the polymer substrate may include films such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether ether ketone (PEEK), and polyimide (PI) in the form of a single layer or a multilayer. However, the present invention is not limited thereto, and any film made of a polymer material may be applied without limitation.

According to an exemplary embodiment of the present invention, the coating thickness of the silica precursor sol solution may be adjusted according to the use of the low refractive silica coating layer, for example, it may be applied to a thickness of 200 nm to 2 μm.

on the substrate The applied silica precursor sol solution dry forming a silica precursor sol layer;

According to an exemplary embodiment of the present invention, the method of manufacturing an optical member including the low refractive index silica coating layer includes drying the silica precursor sol solution applied on the substrate to form a silica precursor sol layer.

According to an exemplary embodiment of the present invention, the forming of the silica precursor sol layer may include drying the applied silica precursor sol at a temperature of 120° C. or less to remove the solvent.

Through the step of forming the silica precursor sol layer, the silica precursor sol may be provided on the substrate. Specifically, through the step of forming the silica precursor sol layer, the silica precursor sol represented by Formula 1 may be evenly distributed on the substrate.

In addition, since the solvent may be evaporated at a low temperature, the solvent may be removed by drying at a temperature of 120 °C or less, 100 °C or less, or 80 °C or less.

According to an exemplary embodiment of the present invention, the step of forming the silica precursor sol layer may be performed at a temperature of 50 °C or more and 120 °C or less, 60 °C or more and 100 °C or less, or 60 °C or more and 80 °C or less.

According to an exemplary embodiment of the present invention, the step of forming the silica precursor sol layer is performed at a temperature of 50 ℃ or more and 120 ℃ or less, 60 ℃ or more and 100 ℃ or less, or 60 ℃ or more and 80 ℃ or less for 30 seconds to 5 minutes. it may be Specifically, the step of forming the silica precursor sol layer may be performed at a temperature of 60 °C to 80 °C for 30 seconds to 2 minutes.

According to an exemplary embodiment of the present invention, the method for manufacturing the low refractive index silica coating layer may further include a step of surface-modifying the silica precursor sol layer by using plasma treatment after the step of forming the silica precursor sol layer. Specifically, according to an exemplary embodiment of the present invention, the step of surface modification may be performed after the step of forming the silica precursor sol layer.

The plasma treatment may be performed by a direct method or an indirect method using atmospheric pressure plasma.

The surface-modifying step may increase contact with a base catalyst including at least one of an amine-based base catalyst and a phosphoric acid-based base catalyst in a subsequent process, and at least one of an amine-based base catalyst and a phosphoric acid-based base catalyst There is an advantage in that the strength of the low-refractive silica coating layer can be improved by increasing the effect during the treatment of the base catalyst including

Forming the silica precursor sol layer may include not only removing all of the solvent in the silica precursor sol solution, but also removing a part of the solvent.

low refraction Formed into a silica coating layer

According to an exemplary embodiment of the present invention, the method for manufacturing an optical member including the low refractive index silica coating layer comprises the steps of contacting the silica precursor sol layer with a base catalyst to form the silica precursor sol layer as a low refractive silica coating layer. include

According to an exemplary embodiment of the present invention, the base catalyst may serve to cure the silica precursor sol on the substrate. Specifically, the base catalyst may cure the silica precursor sol layer including the silica precursor sol represented by Formula 1 into a silica film. The silica film forms a matrix of the low-refractive silica coating layer, and as a material of the same type as the hollow silica particles, a strong bonding force with the hollow silica particles can be implemented in the matrix.

According to an exemplary embodiment of the present invention, the base catalyst may have a boiling point of 80 ℃ or more and 500 ℃ or less.

Further, according to an exemplary embodiment of the present invention, the base catalyst may have a vapor pressure of 10,000 Pa or less, or 5,000 Pa or less, or 1 Pa or less at room temperature (25° C.).

According to an exemplary embodiment of the present invention, the base catalyst may be an anhydride having a boiling point of 80° C. or higher. Specifically, since the base catalyst does not contain moisture, it is possible to effectively dehydrate the silica precursor sol to form a dense cross-linked structure. Specifically, the base catalyst may be a liquid anhydride having a boiling point of 80° C. or higher.

The reaction in which the silica precursor sol represented by Formula 1 is cured to silica by the base catalyst involves a reaction in which water is removed, and when water is present during curing, there is a problem in that the reaction rate is significantly reduced. In order to prevent this, in the step of forming the silica coating layer on the substrate, curing of the silica precursor sol may be rapidly progressed using a base catalyst including at least one of the base catalysts that does not contain moisture.

According to an exemplary embodiment of the present invention, the base catalyst has a high boiling point and a high flash point, is thermally stable, and has the advantage of remarkably low risk of fire during the process. Furthermore, the base catalyst has an advantage that the vapor pressure is low, the odor is small, and the risk of explosion is very low.

According to an exemplary embodiment of the present invention, the base catalyst may be in a liquid phase at a temperature of 120 °C or less.

According to an exemplary embodiment of the present invention, the base catalyst may include an organic solvent. When the base catalyst is in a solid state at a temperature of 120° C. or less, it may be dissolved in an organic solvent and used. Through this, the base catalyst may be in a liquid phase at a temperature of 120 °C or less.

The organic solvent that may be included in the base catalyst is N,N-dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), 1,3-dimethyl-2- Imidazolidinone, N,N-diethylacetamide (DEAc), N,N-dimethylmethoxyacetamide, dimethylsulfoxide, pyridine, dimethylsulfone, hexamethylphosphoamide, tetramethylurea, N-methylcapro Lactam, tetrahydrofuran, m-dioxane, P-dioxane, 1,2-dimethoxyethane, bis(2-methoxyethyl)ether, 1,2-bis(2-methoxyethoxy)ethane, bis In [2-(2-methoxyethoxy)]ether, poly(ethylene glycol)methacrylate (PEGMA), gamma-butyrolactone (GBL), and equaamide (Equamide M100, Idemitsu Kosan Co., Ltd) It may include at least one.

The step of forming the low-refractive silica coating layer is to cure the silica precursor sol using the base catalyst, and there is an advantage that the process can be conveniently performed using a chemical method without going through a high-temperature sintering process. In addition, the base catalyst may prevent deterioration of physical properties by contact with water during curing of the silica precursor sol. Furthermore, since the base catalyst has a high boiling point and a low vapor pressure, it can help improve the working environment by greatly reducing the risk of fire due to exposure to toxic gas or volatility during work.

According to an exemplary embodiment of the present invention, the step of forming the low refractive silica coating layer may be using a dipping method, a coating method, or a spraying method.

Specifically, according to an exemplary embodiment of the present invention, contacting the silica precursor sol provided on the substrate with the base catalyst may use a liquid material deposition method such as spin coating, dip coating, or spray coating.

Specifically, according to an exemplary embodiment of the present invention, in contacting the silica precursor sol layer provided on the substrate with the base catalyst, the substrate provided on one surface of the silica precursor sol layer is immersed in the base catalyst. it may be to do The step of forming the low-refractive silica coating layer may be immersing a substrate having the silica precursor sol represented by General Formula 1 on one surface in the base catalyst.

When the silica precursor sol layer and the base catalyst are brought into contact using the immersion method, the process can be performed very simply, and the production equipment can be minimized.

According to an exemplary embodiment of the present invention, the base catalyst may include at least one of an amine-based base catalyst, a phosphoric acid-based base catalyst, and an imidazole-based base catalyst.

According to an exemplary embodiment of the present invention, the forming of the low refractive silica coating layer may use an amine-based base catalyst. Specifically, according to an exemplary embodiment of the present invention, in the step of forming the silica coating layer, trioctylamine (TOA) may be used as an amine-based base catalyst.

According to an exemplary embodiment of the present invention, the base catalyst may include at least one of compounds represented by the following Chemical Formulas 1 to 10.

[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]

In Formulas 1 to 10,

R1 to R32 are each independently hydrogen; or a linear or branched alkyl group having 1 to 40 carbon atoms; Or an aryl group having 6 to 50 carbon atoms;

n and x are any one integer from 1 to 3, o to q are any one integer from 1 to 4, m and r to w are any one integer from 1 to 5,

When n is 2 or more, R6 can be the same or different, when m is 2 or more, R7 can be the same or different, when o is 2 or more, R16 can be the same or different, and when p is 2 or more, R17 is the same or may be different, and when q is 2 or more, R18 may be the same or different, if r is 2 or more, R19 may be the same or different, and when s is 2 or more, R20 may be the same or different, and t is When u is 2 or more, R21 can be the same or different, when u is 2 or more, R22 can be the same or different, when v is 2 or more, R23 can be the same or different, and when w is 2 or more, R25 is the same or different , and when x is 2 or more, R32 may be the same or different.

In the present specification, the alkyl group may be substituted or unsubstituted, may be linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 1 to 40. Specific examples include methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methyl-butyl, 1-ethyl-butyl, pentyl, n-pentyl , isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n -Heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethyl heptyl, 1-ethyl-propyl, 1,1-dimethyl-propyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl, and the like.

As used herein, "substitution" means that a hydrogen atom bonded to a carbon atom of a compound is replaced with another substituent, and the position to be substituted is not limited as long as the position at which the hydrogen atom is substituted, that is, a position where the substituent is substitutable, is not limited, and two or more substitutions are made. In this case, two or more substituents may be the same as or different from each other.

In the present specification, "substituted or unsubstituted" means deuterium; halogen group; nitrile group; nitro group; hydroxyl group; carbonyl group; ester group; imid; amino group; an alkyl group; cycloalkyl group; alkoxy group; aryloxy group; alkyl thiooxy group; arylthioxy group; an alkyl sulfoxy group; alkenyl group; silyl group; boron group; phosphine oxide group; amine group; arylamine group; aryl group; and one or more substituents selected from the group consisting of a heteroaryl group containing at least one of N, O, S, Se and Si atoms, or is substituted with a substituent to which two or more of the above exemplified substituents are linked, or any It means that it does not have a substituent.

In the present specification, the aryl group may be substituted or unsubstituted, and when the aryl group is a monocyclic aryl group, the number of carbon atoms is not particularly limited, but preferably 6 to 50 carbon atoms. Specifically, the monocyclic aryl group may be a phenyl group, a biphenyl group, a terphenyl group, a quaterphenyl group, and the like, but is not limited thereto. When the aryl group is a polycyclic aryl group, the number of carbon atoms is not particularly limited. It is preferable that it has 10-40 carbon atoms. Specifically, the polycyclic aryl group may be a naphthyl group, an anthracenyl group, a phenanthryl group, a pyrenyl group, a perylenyl group, a chrysenyl group, a fluorenyl group, and the like, but is not limited thereto.

Specifically, according to an exemplary embodiment of the present invention, the base catalyst may include at least one of compounds represented by the following Chemical Formulas 1-1 to 10-3.

[Formula 1-1]

[Formula 2-1]

[Formula 3-1]

[Formula 4-1]

[Formula 5-1]

[Formula 6-1]

[Formula 7-1]

[Formula 8-1]

[Formula 9-1]

[Formula 10-1]

[Formula 10-2]

[Formula 10-3]

According to an exemplary embodiment of the present invention, the forming of the low refractive silica coating layer may include contacting the silica precursor sol layer provided on the substrate with the base catalyst at a temperature of 60°C to 120°C. Specifically, the step of forming the low refractive silica coating layer may be performed at a temperature of 60 °C to 100 °C, or 70 °C to 90 °C. Specifically, in the step of forming the low refractive silica coating layer, the substrate provided with the silica precursor sol layer on one surface is subjected to 60 °C to 120 °C, 60 °C to 100 °C, 70 °C to 90 °C, or 70 °C to 80 °C. It may be immersed in the base catalyst adjusted to °C.

According to an exemplary embodiment of the present invention, the forming of the low refractive silica coating layer may be performed for 1 minute to 20 minutes, or 3 minutes to 10 minutes. Specifically, the step of forming the low-refractive silica coating layer may be performed at a temperature of 70° C. to 90° C. for 3 minutes to 7 minutes.

According to an exemplary embodiment of the present invention, the thickness of the low refractive silica coating layer may be 50 nm or more and 200 nm or less. Specifically, the thickness of the low refractive silica coating layer may be 100 nm or more and 150 nm or less.

When the thickness of the low-refractive silica coating layer is within the above range, the optical member may appropriately control destructive interference between light reflected from the surface of the low-refractive silica coating layer and light reflected from the interface between the low-refractive silica coating layer and the substrate. It is possible to implement a low light reflectance of the optical member.

Since the manufacturing method of the optical member including the low refractive silica coating layer according to an exemplary embodiment of the present invention is performed at a low temperature of 120° C. or less, there is an advantage in that the low refractive silica coating layer can be directly formed on the polymer substrate. Specifically, in the method for manufacturing an optical member including a low refractive silica coating layer according to an exemplary embodiment of the present invention, since the entire process is performed at a temperature of 120 ℃ or less, 100 ℃ or less, or 80 ℃ or less, thermal deformation of the polymer substrate There is an advantage of preventing , and by using this, it is possible to form a low refractive silica coating layer directly on the polymer substrate.

Furthermore, the low-refractive silica coating layer manufactured by the method for manufacturing an optical member including the low-refractive silica coating layer achieves high rigidity equal to or higher than that of the silica coating layer that undergoes a high-temperature firing process of 500 ° C. can Furthermore, since the method for manufacturing an optical member including a low refractive silica coating layer according to the present invention does not fix the hollow silica particles through a polymer binder, there is an advantage that the hollow silica particles do not fall off after the coating layer is prepared. .

According to an exemplary embodiment of the present invention, the optical member including the low-refractive silica coating layer may be manufactured by a roll-to-roll continuous process.

Since the manufacturing method according to an exemplary embodiment of the present invention is performed as a solution process rather than a deposition process, it has the advantage of being very suitable for mass production through a continuous roll-to-roll process. Furthermore, since the manufacturing method according to an exemplary embodiment of the present invention does not require a high-temperature firing process, a flexible polymer substrate having low heat resistance can be applied. Therefore, the manufacturing method according to an exemplary embodiment of the present invention can directly form a low refractive silica coating layer on a flexible polymer substrate by using a roll-to-roll continuous process.

An exemplary embodiment of the present invention provides an optical member including a low-refractive silica coating layer prepared by the above manufacturing method. Specifically, an exemplary embodiment of the present invention provides an optical member provided with a low refractive silica coating layer prepared by the above manufacturing method on one surface of a substrate.

Specifically, since the low refractive silica coating layer has excellent surface strength and low refractive index, it can be applied as a low reflection coating layer of a display device.

According to an exemplary embodiment of the present invention, the substrate may be a polarizing film, a brightness enhancing film, or a retardation film. Specifically, the optical member may be a polarizing plate provided with the low refractive silica coating layer.

One embodiment of the present invention provides a display device including the optical member.

Hereinafter, examples will be given to describe the present invention in detail. However, the embodiments according to the present invention may be modified in various other forms, and the scope of the present invention is not to be construed as being limited to the embodiments described below. The embodiments of the present specification are provided to more completely explain the present invention to those of ordinary skill in the art.

[ Example 1 to Example 5]

A silica precursor dispersion was prepared by mixing TEOS with ethanol. The prepared silica precursor dispersion was stirred, and an aqueous hydrochloric acid solution was added dropwise to prepare a silica precursor sol solution. The molar ratio of TEOS, ethanol, water, and hydrochloric acid in the preparation of the silica precursor sol solution was 1:4:4:0.2.

Assuming that the TEOS is 100% reacted, the silica solid content of the silica precursor sol solution is calculated to be about 11 wt%. That is, the content of the silica precursor sol in the silica precursor sol solution is about 11 wt%.

Furthermore, a hollow silica dispersion (LG CHEM, Ltd.) in which hollow silica particles having an outer diameter of 40 nm to 70 nm and an inner diameter of 5 nm to 10 nm were dispersed in isopropyl alcohol at a content of 20 wt% was prepared.

A silica precursor sol solution having a concentration of 1 wt% was prepared so that the weight ratio of the silica precursor sol and the hollow silica particles was adjusted as shown in Table 1 below. The concentration of the silica precursor sol solution was the total content of the silica precursor sol and the hollow silica particles in the silica precursor sol solution, and the concentration of the silica precursor sol solution was adjusted using isopropyl alcohol.

The silica precursor sol solution was coated on a hard-coated triacetyl cellulose (TAC) substrate using bar coating to form a coating layer, and then dried in a convection oven at 80° C. for 1 minute. Furthermore, the substrate on which the coating layer was formed was immersed in trioctyl amine (TOA) at 80° C. for 5 minutes and then taken out and washed with distilled water at 40° C. Thereafter, the water was removed and dried in a convection oven at 80° C. for 2 minutes to prepare an optical member having a low refractive silica coating layer on the substrate.

[ comparative example One]

An optical member was prepared in the same manner as in Example 1, except that the silica precursor sol solution without mixing the hollow silica dispersion was used.

Examples 1 to 5 and the average thickness and average optical refractive index of Comparative Example 1 are shown in Table 1 below.

Silica Precursor Sol: Hollow Silica Particles
(weight ratio) light refractive index
(%, @550nm) thickness
(nm) Comparative Example 1 1:0 1.451 43 Example 1 5:2 1.343 96 Example 2 5:3 1.341 121 Example 3 5:4 1.307 120 Example 4 5:5 1.293 134 Example 5 7:13 1.249 124

In the present specification, the optical refractive index was measured using an ellipsometer (JA Woollam, M-2000UI) according to the wavelength of the sample, and the optical refractive index and thickness were measured at 10 arbitrary points of the sample. The average value of the thickness measurements was taken.

In the present specification, the light reflectance is measured by using a spectrophotometer (Konica Minolta, CM-2600d) after attaching the sample to the black PET, and measuring the light reflectance for each wavelength including the specular light. Specifically, the light reflectance is the The average value of the measured values of the light reflectance at 10 points where the light refractive index was measured was taken.

According to Table 1, compared to the optical refractive index of Comparative Example 1 not including the hollow silica particles, Examples 1 to 4 including the hollow silica particles can be confirmed to implement a low optical refractive index. Furthermore, as in Example 5, when the weight ratio of the silica precursor sol and the hollow silica particles was 7:13, a very good refractive index could be realized.

[ Example 6 and Example 7]

An optical member was manufactured in the same manner as in Example 5, except that the concentration of the silica precursor sol solution was adjusted as shown in Table 2 below.

Concentration of silica precursor sol solution
(wt%) average thickness
(nm) average refractive index
(%, @550nm) Average light reflectance
(%, @550nm) Example 6 6.6 69 1.255 1.8 Example 7 9.4 129 1.258 0.7

According to Table 2, it can be seen that the low refractive silica coating layer according to the present invention can implement low light reflectance, and in particular, in the case of Example 7, the minimum light reflectance is 0.39% at a wavelength of 550 nm, and very low light It was confirmed that the refractive index can be implemented.

[ Example 8 to Example 13]

An optical member was manufactured in the same manner as in Example 1, except that the concentration of the silica precursor sol solution was adjusted to 9.4 wt% and the weight ratio of the silica precursor sol and the hollow silica particles was adjusted as shown in Table 3 below.

[ comparative example 2]

An optical member was prepared in the same manner as in Example 1, except that a silica precursor sol solution in which the hollow silica dispersion was not mixed was used as the silica precursor sol solution, and the concentration of the silica precursor sol solution was adjusted to 9.4 wt%.

[ comparative example 3]

Using an acrylate monomer as a binder resin, a resin composition containing an acrylate monomer and a hollow silica particle in a weight ratio of 7:3 is coated on a triacetyl cellulose (TAC) substrate to form a coating layer, which is then photocured. An optical member provided with a low refractive index coating layer was manufactured.

The average light reflectance and steel wool hardness of Examples 8 to 12 and Comparative Example 2 are shown in Table 3 below.

Silica Precursor Sol: Hollow Silica Particles
(weight ratio) Average light reflectance
(%, @550nm) steel wool hardness Comparative Example 2 1:0 2.6 1.4 kg OK Example 8 8:2 1.7 1.1 kg OK Example 9 7:3 1.4 1.1 kg OK Example 10 6:4 1.1 600 g OK Example 11 5:5 0.8 500 g OK Example 12 4:6 0.8 300 g OK Example 13 3.5:6.5 0.4 250g OK Comparative Example 3 - 1.4 500 g OK

In this specification, the steel wool hardness is measured by using an abrasion tester (Gibei E&T, KP-M4360), applying a load to the sample surface and repeating 10 times at 25 cpm (cycle per minute) to visually check whether the surface is damaged. method was measured.

According to Table 3, compared to the light reflectivity of Comparative Example 2 not including the hollow silica particles, Examples 8 to 13 including the hollow silica particles can be confirmed to implement low light reflectance. As the content of the hollow silica particles increases, the steel wool hardness decreases, but in the case of Examples 8 and 9, it can be confirmed that the steel wool hardness of 1 kg or more is realized, thereby realizing very good surface hardness. Specifically, it can be seen that the low-refractive silica coating layer according to the embodiment exhibits a characteristic that the hollow silica particles do not easily fall off, unlike the conventional low-refractive coating layer including hollow silica particles. This is because the low-refractive coating layer according to the embodiment forms a silica film using a silica precursor sol, it can exhibit a surface strength differentiated from the low-refractive coating layer in which hollow silica particles are dispersed in an existing polymer matrix. Furthermore, compared to the low refractive index coating layer including the hollow silica particles in the existing polymer matrix, the low refractive silica coating layer according to the embodiment may implement a characteristic in which the hollow silica particles are not easily removed.

Claims (16)

preparing a silica precursor dispersion comprising a solvent and an alkoxy silane;
adding an acidic catalyst to the silica precursor dispersion to form a silica precursor sol solution comprising a silica precursor sol;
mixing the silica precursor sol solution and hollow silica particles;
applying a silica precursor sol solution including the hollow silica particles on a substrate;
drying the silica precursor sol solution applied on the substrate to form a silica precursor sol layer; and
contacting the silica precursor sol layer with a base catalyst to form the silica precursor sol layer as a low refractive silica coating layer;
All of the above processes are a method of manufacturing an optical member comprising a low-refractive silica coating layer that is carried out in an atmosphere of 120 ℃ or less. The method according to claim 1,
The content of the silica precursor sol in the silica precursor sol solution is 5 wt% or more and 40 wt% or less. The method according to claim 1,
A weight ratio of the silica precursor sol and the hollow silica particles is 8:2 to 2:8. A method of manufacturing an optical member comprising a low refractive silica coating layer. The method according to claim 1,
An average outer diameter of the hollow silica particles is 20 nm or more and 100 nm or less. A method of manufacturing an optical member comprising a low refractive silica coating layer. The method according to claim 1,
The base catalyst is an anhydride having a boiling point of 80° C. or more. A method of manufacturing an optical member comprising a low refractive silica coating layer. The method according to claim 1,
The base catalyst is a method of manufacturing an optical member comprising a low refractive index silica coating layer comprising at least one of an amine-based base catalyst, a phosphoric acid-based base catalyst, and an imidazole-based base catalyst. The method according to claim 1,
The base catalyst is a method of manufacturing an optical member comprising a low refractive silica coating layer comprising at least one of the compounds represented by the following Chemical Formulas 1 to 10:
[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

[Formula 10]

In Formulas 1 to 10,
R1 to R32 are each independently hydrogen; or a linear or branched alkyl group having 1 to 40 carbon atoms; Or an aryl group having 6 to 50 carbon atoms;
n and x are any one integer from 1 to 3, o to q are any one integer from 1 to 4, m and r to w are any one integer from 1 to 5,
When n is 2 or more, R6 can be the same or different, when m is 2 or more, R7 can be the same or different, when o is 2 or more, R16 can be the same or different, and when p is 2 or more, R17 is the same or may be different, and when q is 2 or more, R18 may be the same or different, if r is 2 or more, R19 may be the same or different, and when s is 2 or more, R20 may be the same or different, and t is When u is 2 or more, R21 can be the same or different, when u is 2 or more, R22 can be the same or different, when v is 2 or more, R23 can be the same or different, and when w is 2 or more, R25 is the same or different , and when x is 2 or more, R32 may be the same or different. The method according to claim 1,
The solvent is an alcohol-based solvent; ketone solvents; and an organic solvent including at least one of acetate-based solvents. The method according to claim 1,
The alkoxy silane is tetraethoxysilane, tetramethoxysilane, methoxyethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, trimethoxyphenylsilane, triethoxyphenylsilane, 2-(3, 4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, 3-(acryloyloxy)propyltrimethoxysilane, 1,2-bis(tri Ethoxysilane) ethane, and 3-methacryloxypropyl trimethoxysilane method of manufacturing an optical member comprising a low refractive index silica coating layer comprising at least one. The method according to claim 1,
The forming of the silica precursor sol solution includes adjusting the pH of the silica precursor dispersion to 0 to 5. A method of manufacturing an optical member including a low refractive silica coating layer. The method according to claim 1,
The acid catalyst includes at least one of hydrochloric acid, sulfuric acid, fluorosulfuric acid, nitric acid, phosphoric acid, acetic acid, hexafluorophosphoric acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid. manufacturing method. delete The method according to claim 1,
The step of forming the low-refractive silica coating layer is a method of manufacturing an optical member comprising a low-refractive silica coating layer in which the silica precursor sol layer provided on the substrate is brought into contact with the base catalyst at a temperature of 60° C. to 120° C. . The method according to claim 1,
The optical member including the low-refractive silica coating layer is a method of manufacturing an optical member comprising a low-refractive silica coating layer that is manufactured by a roll-to-roll continuous process. An optical member comprising a low-refractive silica coating layer manufactured by the manufacturing method according to claim 1 . 16. The method of claim 15,
The substrate is an optical member including a low refractive index silica coating layer that is a polarizing film, a brightness enhancing film, or a retardation film.