KR20220059812A - Optical laminate - Google Patents

Abstract

The present invention relates to an optical laminate, a polarizing plate including the optical laminate, a display device, and an organic light emitting diode display device. The optical laminate includes a polymer resin layer and an optical function layer formed on one surface of the polymer resin layer and including a binder resin, a hollow-type inorganic nano particle, and a solid-type inorganic particle. The optical function layer has a particle mixed layer including the hollow-type inorganic nano particle and the solid-type inorganic particle. The binder resin included in the optical function layer includes a(meth) acrylate resin including 1 to 3 of carbon numbers of alkylene oxide.

Description

Optical laminate {OPTICAL LAMINATE}

The present invention relates to an optical laminate, and more particularly, to an optical laminate capable of simultaneously implementing high scratch resistance and antifouling properties while having low reflectivity and haze and high transmittance, and increasing the clarity of the screen of a display device. will be.

In general, flat panel display devices such as PDPs and LCDs are equipped with optical films for minimizing reflection of light incident from the outside.

As a method for minimizing light reflection, a method of dispersing a filler such as inorganic fine particles in a resin, coating it on a base film, and imparting irregularities (anti-glare: AG coating); There is a method of using interference of light by forming a plurality of layers having different refractive indices on a base film (anti-reflection: AR coating) or a method of mixing them.

Among them, in the case of the AG coating, the absolute amount of reflected light is equivalent to that of a general hard coating, but a low reflection effect can be obtained by reducing the amount of light entering the eye using light scattering through irregularities. However, since the AG coating lowers the sharpness of the screen due to the uneven surface, many studies have been made on the AR coating in recent years.

As a film using the AR coating, a multilayer structure in which a high refractive index layer, a low reflection coating layer, etc. are laminated on a base film is commercially available. However, the method of forming a plurality of layers as described above has a disadvantage in that the interlayer adhesion (interfacial adhesion) is weak as the process of forming each layer is separately performed, and thus scratch resistance is poor.

In addition, in the past, in order to improve the scratch resistance of the AR coating, a method of adding various particles of nanometer size (eg, particles of silica, alumina, zeolite, etc.) was mainly attempted. However, when nanometer-sized particles are used as described above, there is a limitation in that it is difficult to simultaneously increase scratch resistance while lowering reflectance, and the antifouling property of the surface of the optical film is greatly reduced due to nanometer-sized particles.

Accordingly, many studies have been made to reduce the absolute reflection amount of light incident from the outside and to improve antifouling properties along with scratch resistance of the surface, but the degree of improvement in physical properties is insufficient.

An object of the present invention is to provide an optical laminate having high light transmittance and high scratch resistance and antifouling properties at the same time, while implementing low reflectance and haze, improving black visibility, and having colorless and transparent properties.

In addition, the present invention is to provide a polarizing plate including the optical laminate.

Another object of the present invention is to provide a display device including the optical laminate.

In addition, the present invention is to provide an organic light emitting diode display device including the optical laminate.

In the present specification, a polymer resin layer; and an optical functional layer formed on one surface of the polymer resin layer and including a binder resin, hollow inorganic nanoparticles, and solid inorganic nanoparticles, and including the hollow inorganic nanoparticles and solid inorganic nanoparticles The particle mixture layer is present in the optical functional layer, and the binder resin included in the optical functional layer is an optical laminate comprising a (meth)acrylate-based resin including an alkylene oxide having 1 to 3 carbon atoms.

In addition, in the present specification, a polarizing plate including the optical laminate and the polarizer is provided.

In addition, in the present specification, a display device including the optical laminate is provided.

In addition, in the present specification, an organic light emitting diode display device including the optical laminate is provided.

Hereinafter, an optical laminate, a polarizing plate, a display device, and an organic light emitting diode display device according to specific embodiments of the present invention will be described in more detail.

In the present specification, the photopolymerizable compound refers to a compound that causes a polymerization reaction when light is irradiated, for example, when irradiated with visible light or ultraviolet light.

In addition, the fluorine-containing compound refers to a compound containing at least one element of fluorine among the compounds.

In addition, (meth)acryl [(Meth)acryl] is meant to include both acryl (acryl) and methacrylate (Methacryl).

In addition, the (co)polymer is meant to include both a copolymer (co-polymer) and a homo-polymer (homo-polymer).

In addition, the hollow silica particles (silica hollow particles) are silica particles derived from a silicon compound or an organosilicon compound, and means particles in the form of voids present on the surface and/or inside of the silica particles.

According to one embodiment of the invention, a polymer resin layer; and an optical functional layer formed on one surface of the polymer resin layer and including a binder resin, hollow inorganic nanoparticles, and solid inorganic nanoparticles, and including the hollow inorganic nanoparticles and solid inorganic nanoparticles An optical laminate comprising a (meth)acrylate-based resin including an alkylene oxide having 1 to 3 carbon atoms may be provided. there is.

When the optical film including the optical function layer has a low refractive index, the reflectance in the blue region is higher than the reflectance in the green region. For this reason, the film may have a blue color, and may have opacity or color properties that are not suitable for application to a polarizing plate or a display device.

Accordingly, the present inventors conducted research on an optical laminate, and an optical laminate including a polymer resin layer and an optical functional layer formed on one surface of the polymer resin layer, the hollow inorganic nanoparticles and solid in the optical functional layer Due to the presence of a particle mixture layer including type inorganic nanoparticles and the (meth)acrylate-based resin including an alkylene oxide having 1 to 3 carbon atoms in the binder resin included in the optical functional layer, low reflectance and haze, while improving the sense of blackness and remarkably reducing the degree of blue color, it was confirmed through experiments that it was possible to have colorless and transparent characteristics, and the invention was completed.

In addition, the optical laminate may have a feature of simultaneously implementing high scratch resistance and antifouling properties while having a high light transmittance together with the above-described characteristics.

Specifically, the (meth)acrylate-based resin containing an alkylene oxide having 1 to 3 carbon atoms contained in the binder resin of the optical functional layer has excellent compatibility with other components included in the optical functional layer, Light transmittance and strength can be improved while the haze of the optical functional layer is controlled to be low

The (meth)acrylate-based resin comprising an alkylene oxide having 1 to 3 carbon atoms is, for example, trimethylolpropane ethoxylate triacrylate, trimethylolpropane propoxylate triacrylate (Trimethylolpropane propoxylate triacrylate), ethoxylate pentaerythritol tetraacrylate (Ethoxylated Pentaerythritol tetraacrylate) and bisphenol F ethoxylate diacrylate (Bisphenol F ethoxylate diacrylate) may be at least one selected from the group consisting of.

On the other hand, whether the (meth) acrylate-based resin containing the alkylene oxide having 1 to 3 carbon atoms is included in the optical functional layer can be confirmed through infrared spectroscopy analysis (IR Spectroscopy analysis). Specifically, in the binder containing the (meth)acrylate-based resin including the alkylene oxide having 1 to 3 carbon atoms, in the IR spectrum for the binder resin, the area of the peak present in the region of 1710 to 1780 cm ^-1 The ratio (A ₂ /A ₁ ) of the area (A ₂ ) of the peak present in the region of 2860 to 2880 cm ^-1 to (A ₁ ) may be 0.08 to 1.0, 0.09 to 0.15, 0.10 to 0.12.

The peak present in the 1710 to 1780 cm ^-1 region may be, for example, a peak of a carbon-oxygen double bond (C=O), and the peak present in the 2860 to 2880 cm ^-1 region is, for example, a carbon-oxygen double bond (C=O) peak. It may be a peak of a hydrogen single bond (CH).

The optical function layer may further include other photopolymerizable compounds in addition to the (meth)acrylate-based resin containing the alkylene oxide having 1 to 3 carbon atoms.

The photopolymerizable compound may include, for example, (meth)acrylate or a monomer or oligomer including a vinyl group. More specifically, the photopolymerizable compound may include a monomer or oligomer including one or more, or two or more, or three or more (meth)acrylate or vinyl groups.

Specific examples of the monomer or oligomer containing the (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) ) acrylate, tripentaerythritol hepta (meth) acrylate, torylene diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, trimethylolpropane tri(meth)acrylate, trimethylolpropane polyethoxytri(meth)acrylic Late, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, butanediol dimethacrylate, hexaethyl methacrylate, butyl methacrylate, or a mixture of two or more thereof, or urethane-modified acrylate oligomer, epoxy side acrylate oligomers, ether acrylate oligomers, dendritic acrylate oligomers, or mixtures of two or more thereof. In this case, the molecular weight of the oligomer is preferably 1,000 to 10,000.

Specific examples of the monomer or oligomer including the vinyl group include divinylbenzene, styrene, or paramethylstyrene.

The content of the photopolymerizable compound in the photocurable coating composition is not particularly limited, but the content of the photopolymerizable compound in the solid content of the photocurable coating composition in consideration of the mechanical properties of the optically functional layer or optical laminate to be finally manufactured Silver may be 5 wt% to 80 wt%. The solid content of the photocurable coating composition refers to only solid components excluding components such as liquid components in the photocurable coating composition, for example, organic solvents that may be selectively included as described below.

A particle mixture layer including both hollow inorganic nanoparticles and solid inorganic nanoparticles may be present in the optical functional layer. Due to the presence of the particle mixture layer, the optical laminate may have a colorless and transparent property while implementing a low reflectance. High scratch resistance and antifouling properties can be realized at the same time.

Specifically, the optical functional layer may be formed on one surface of the polymer resin layer, and the mixed particle layer may be positioned at a distance of 50 nm or more from one surface of the polymer resin layer, or the particle mixed layer is the Positioned at a distance of 50 nm to 250 nm, or 60 nm to 220 nm, or 70 nm to 200 nm, or 80 nm to 180 nm, or 90 nm to 150 nm, or 100 nm to 120 nm from one surface of the polymer resin layer can do.

As the particle mixture layer is positioned at a distance of 50 nm or more from one surface of the polymer resin layer, it serves to alleviate the sharp difference in refractive index between the layers in the optical functional layer, so that the reflectance at the wavelength of 550 nm is 0.5 % or less, the absolute value of the slope of the reflectance pattern in the short wavelength region of the optical laminate is lowered.

When the particle mixture layer is located in a region less than 50 nm from one surface of the polymer resin layer, the effect of alleviating the difference in refractive index between the layers in the optical functional layer is limited, so that the reflectance at the wavelength of 550 nm is 0.5% or less The absolute value of the inclination of the reflectance pattern of the optical laminate is not sufficiently found.

The distance between the mixed particle layer and the polymer resin layer may be determined as the shortest distance among the distances between one surface of the polymer resin layer and the particle mixed layer based on the plane direction of the polymer resin layer. Alternatively, the distance between the mixed particle layer and the polymer resin layer may be defined as a thickness of a region between the mixed particle layer from one surface of the polymer resin layer.

The existence of a region between the particle mixture layer from one surface of the polymer resin layer can be confirmed by ellipsommetry. When the ellipticity of the polarization measured by ellipsometry for each region between the particle mixed layer or the polymer resin layer from one surface of the particle mixed layer or the polymer resin layer is optimized with a Cauchy model, a specific Cauchy model It has parameters A, B, and C, and accordingly, each region between the particle mixed layer or the particle mixed layer from one surface of the polymer resin layer may be distinguished from each other.

Specifically, for the optical functional layer, J. A. Woollam Co. Using the device of the M-2000, it is possible to apply an incident angle of 70° and measure linear polarization in the wavelength range of 380 to 1000 nm. The measured linear polarization measurement data (Ellipsometry data (Ψ, Δ)) is optimized (fitting) with the Cauchy model of the following general formula 2 for the detailed layers in the optical functional layer using Complete EASE software. can

[General formula 2]

In Formula 2, n(λ) is a refractive index at a wavelength of λ, λ is in the range of 300 nm to 1800 nm, and A, B and C are Cauchy parameters.

In addition, the particle mixture layer or the polymer resin layer through the optimization (fitting) of the ellipticity of the polarization measured by the ellipsometry (Cauchy model) and the diffusion layer model (Diffuse Layer Model) of the general formula (2) Since the thickness of each region between the particle mixed layer can also be derived from one surface, each region between the particle mixed layer from one surface of the particle mixed layer or the polymer resin layer in the optical functional layer can be defined.

In addition, in the optical laminate having a reflectance of 0.5% or less at a wavelength of 550 nm, the ratio of the reflectance at a wavelength of 400 nm to the reflectance at a wavelength of 550 nm is 5 or more, 5 to 20, 5.5 to 15, or 6 to 12. there is.

As the optical laminate satisfies the characteristic that the ratio of the reflectance at a wavelength of 400 nm to the reflectance at a wavelength of 550 nm is 5 or more, or 5 to 20, or 5.5 to 15, or 6 to 12, the optical laminate is green The reflectance in the blue region may have a low optical characteristic compared to the reflectance in the region, and thus may have a colorless and transparent characteristic while realizing a low reflectance.

When the ratio of the reflectance at a wavelength of 400 nm to the reflectance at a wavelength of 550 nm of the optical laminate having a reflectance of 0.5% or less at a wavelength of 550 nm is less than 5, the optical laminate becomes blue and applied to a polarizing plate or a display device It may have a degree of opacity or color that is not suitable for In particular, in the case of an optical laminate having a ratio of reflectance at a wavelength of 400 nm to that at a wavelength of 550 nm of less than 5, the color reproducibility of the organic light emitting diode display device may be deteriorated.

Satisfies that the ratio of the reflectance at a wavelength of 400 nm to the reflectance at a wavelength of 550 nm of the optical laminate having a reflectance at a wavelength of 550 nm of 0.5% or less is 5 or more, or 5 to 20, or 5.5 to 15, or 6 to 12 In this range, the reflectance at a wavelength of 550 nm of the optical laminate may be 0.05% to 5.0%, or 0.06 to 4.0%, or 0.07 to 3.0%, or 0.08% to 0.3%.

In addition, the reflectance at 400 nm of the optical laminate may be 0.5% to 3.50%, or 0.80% to 2.0%.

The ratio of the reflectance at a wavelength of 700 nm to the reflectance at a wavelength of 550 nm of the optical laminate may be 5 or more, or 5 to 20, or 6 to 15, or 7 to 12. Accordingly, the optical laminate may have low reflectance in the blue region compared to the reflectance in the green region, and thus may have a colorless and transparent characteristic while realizing a low reflectance. When the reflectance at a wavelength of 700 nm is too high compared to the reflectance at a wavelength of 550 nm, the reflectance in the red light region is relatively high, and the optical film may appear yellow or red.

On the other hand, the optical laminate having a reflectance of 0.5% or less at a wavelength of 550 nm includes a particle mixed layer having the predetermined thickness in the optical functional layer, and the reflectance at the wavelength of 550 nm is 0.5% or less of the optical laminate. The ratio of the reflectance at a wavelength of 400 nm to the reflectance at a wavelength of 550 nm may be 5 or more, or 5 to 20, or 5.5 to 15, or 6 to 12, so that the optical laminate is b in the CIE Lab color space. The absolute value of * may be 4 or less, or 3 or less, or 2 or less, or 1.5 or less.

Each value in the CIE Lab color space can be measured by applying a general method of measuring each coordinate of the color space, for example, a spectrophotometer having a detector in the form of an integrating sphere at the measurement position. ) (ex. CM-2600d, KONICA MINOLTA), can be measured according to the manufacturer's manual. In one example, each coordinate of the CIE Lab color space may be measured while the polarizer or polarizing plate is attached to a liquid crystal panel, for example, the highly reflective liquid crystal panel, or may be measured with respect to the polarizer or polarizing plate itself. .

The CIE Lab color space is a color space obtained by non-linear transformation of the CIE XYZ color space based on the antagonistic theory of human vision. In this color space, the L* value represents brightness, an L* value of 0 indicates black, and an L* value of 100 indicates white. In addition, if the value of a* is negative, the color is biased toward green, and if the value of a* is positive, the color is biased toward red. Also, if the b* value is negative, the color is biased toward blue, and if the b* value is positive, the color is biased toward yellow.

That is, the optical laminate has a characteristic that the absolute value of b* value in the CIE Lab color space is 4 or less, or 3 or less, or 2 or less, or 1.5 or less, so that red or blue color while implementing low reflectance It can have a colorless and transparent characteristic by remarkably reducing the degree of visibility.

More specifically, the reflectance at a wavelength of 550 nm of the optical laminate may be 0.5% or less, and the absolute value of the b* value in the CIE Lab color space is 4 or less, or 3 or less, or 2 or less while implementing such a low reflectance. , or 1.5 or less.

As described above, as the absolute value of b* value in the CIE Lab color space is maintained at a low level while implementing a low reflectance, the optical laminate is easily applied to a display having a high contrast ratio and luminance, resulting in high color reproducibility can be implemented.

In order to have the above-described characteristics of the optical laminate, hollow inorganic nanoparticles and solid inorganic nanoparticles are included together in the optical functional layer, and 25 to 100 nm, or 35 nm to 90 nm, or 40 nm to 85 nm There may be a mixed-particle layer having a thickness of nm, or 50 nm to 80 nm, or 60 nm to 75 nm.

If the thickness of the particle mixture layer is too small, scratch resistance of the optical functional layer may be low. On the other hand, when the thickness of the particle mixture layer is too thick, optical properties such as transparency of the optical laminate may be deteriorated accordingly.

The refractive index or thickness of the particle mixture layer can be confirmed through various optical measurement methods, for example, the ellipticity of the polarization measured by ellipsometry is optimized with a diffusion layer model (fitting), etc. It can also be checked using .

The ellipticity and related data (Ellipsometry data (Ψ, Δ)) of the polarization measured by the ellipsometry can be measured using a commonly known method and apparatus. For example, for the particle mixed layer or other regions included in the optical functional layer, J. A. Woollam Co. Using the device of the M-2000, it is possible to apply an incident angle of 70° and measure linear polarization in the wavelength range of 380 to 1000 nm.

The measured linear polarization measurement data (Ellipsometry data (Ψ, Δ)) is a diffusion layer model for the particle mixed layer using Complete EASE software, and for the lower layer and upper layer of the particle mixed layer, Kosch of the following general formula 2 It can be optimized (fitting) so that the MSE is 5 or less by dividing the two layers with a model (Cauchy model).

[General formula 2]

In Formula 2, n(λ) is a refractive index at a wavelength of λ, λ is in the range of 300 nm to 1800 nm, and A, B and C are Cauchy parameters.

When the thickness and refractive index range of the particle mixture layer included in the optical functional layer satisfy the above-described range, a sharp difference in refractive index between each layer can be alleviated, and accordingly, the optical laminate realizes a low reflectance while maintaining the absolute value of the b* value at a low level in the CIE Lab color space.

The optical functional layer includes a binder resin and hollow inorganic nanoparticles, solid silica nanoparticles, and solid zirconia nanoparticles dispersed in the binder resin, and the weight ratio of the solid zirconia nanoparticles to the solid silica nanoparticles may be 10 or more, 15 to 40, 20 to 30, or 23 to 28.

Since the solid-type zirconia nanoparticles are included in a weight ratio of 10 or more compared to the solid-type silica nanoparticles, it is possible to simultaneously implement high scratch resistance and antifouling properties while having high light transmittance, and while implementing low reflectance and haze, a black feeling is improved improved, and can exhibit colorless and transparent properties.

On the other hand, when the weight ratio of the solid-type zirconia nanoparticles to the solid-type silica nanoparticles is less than 10, the thickness of the particle mixed layer may increase, and this may not give an appropriate refractive index difference, so reflectance and haze may increase there is.

On the other hand, the composition of the binder resin included in the optical functional layer, the type or content of particles, the specific process (for example, coating speed, coating method or drying conditions, etc.) when forming the optical functional layer, the characteristics of the polymer resin layer, etc. are controlled Thus, a particle mixture layer can be formed in the optical function layer.

This example is only an example of a method or means for forming the mixed particle layer, and the mixed particle layer is not formed in the optical functional layer only when the method or means is used at the same time, and detailed materials for forming the optical functional layer and It can be adjusted according to the content thereof, the thickness of the optical functional layer, the detailed material of the polymer resin layer and their content, the surface characteristics and thickness of the polymer resin layer, and the like. That is, the presence of the particle mixture layer in the optical functional layer and the effect thereof can be implemented based on the description or the embodiment of the specification.

For example, the polymer resin layer included in the optical laminate may include a binder resin including a photocurable resin and organic or inorganic fine particles dispersed in the binder resin, and on this polymer resin layer, a binder resin and When the optical functional layer including the hollow inorganic nanoparticles and the solid inorganic nanoparticles is formed under predetermined conditions, the particle mixed layer may exist.

In addition, the polymer resin layer included in the optical laminate may have a surface energy of 34 mN/m or more, or 34 mN/m to 60 mN/m, or 35 mN/m to 55 mN/m. When an optical functional layer including a binder resin and hollow inorganic nanoparticles and solid inorganic nanoparticles is formed on a polymer resin layer having a surface energy of a range, the surface energy in the optical functional layer due to the high surface energy of the interface In the optimization process, the above-mentioned mixed-particle layer may be formed.

The surface energy of the polymer resin layer may be obtained by controlling the surface properties of the polymer resin layer. For example, the surface energy of the polymer resin layer may be controlled by adjusting the degree of surface hardening and drying conditions of the polymer resin layer.

Specifically, the degree of curing of the polymer resin layer can be adjusted by adjusting curing conditions, for example, the amount of light or the intensity of light irradiation or the flow rate of injected nitrogen during the formation of the polymer resin layer. For example, in a state in which the polymer resin layer is purged with nitrogen to apply nitrogen atmospheric conditions, the resin composition forming the polymer resin layer is applied at an exposure dose of 5 to 100 mJ/cm 2 , or 10 to 25 mJ/cm 2 It can be obtained by irradiating ultraviolet rays.

The surface energy is averaged after measuring the contact angle of di-water (Gebhardt) and di-iodomethane (Owens) at 10 points using a commonly known measuring device, for example, Kruss' DSA-100 contact angle measuring device. It can be measured by converting the contact angle into surface energy. Specifically, in the measurement of the surface energy, the contact angle can be converted into surface energy by using Dropshape Analysis software and applying the following general formula 1 of the OWRK (Owen, Wendt, Rable, Kaelble) method to the program.

[General formula 1]

In addition, as will be described later, the particle mixture layer may be formed by applying a drying temperature, an air volume control, etc. when forming the optical function layer.

Specifically, by adjusting the drying conditions, for example, intake or exhaust amount in the process of forming the optical functional layer, the air volume may be adjusted in the drying process. For example, in the drying process after coating the optical function layer, the air volume is set to 0.5 m/s or more, or 0.5 m/s to 10 m/s, or 0.5 m/s to 8 m/s, or 0.5 m/s to 5 m/s. It can also be done in s.

More specifically, the optical functional layer is formed on one surface of the polymer resin layer, and the optical functional layer may include hollow inorganic nanoparticles and solid inorganic nanoparticles dispersed in a binder resin, in which case the optical In the functional layer, 50 vol% or more, or 60 vol% or more, or 70 vol% or more, or more than the above values or 95 vol% or less of the total of the solid inorganic nanoparticles in the functional layer is between the particle mixture layer from one surface of the polymer resin layer may exist in

As such, as the solid inorganic nanoparticles are mainly distributed in the region between the particle mixture layer from one surface of the polymer resin layer, the region between the particle mixture layer from one surface of the polymer resin layer is 1.46 to 1.75 at a wavelength of 550 nm. It may have a refractive index of

'More than 50% by volume of the total of the solid inorganic nanoparticles is present in the specific region' is defined as meaning that most of the solid inorganic nanoparticles are present in the specific region in the cross section of the optical functional layer, specifically, More than 70% by volume of the total solid inorganic nanoparticles can be confirmed by measuring the total volume of the solid inorganic nanoparticles.

For example, it can be visually confirmed that each of the regions in which the solid inorganic nanoparticles and the hollow inorganic nanoparticles are mainly distributed is present in the optical functional layer. For example, using a transmission electron microscope or a scanning electron microscope, it is possible to visually confirm that an individual layer or each region exists in the optical functional layer, and also within the optical functional layer. You can also check the ratio of solid inorganic nanoparticles and hollow inorganic nanoparticles distributed in the corresponding layer or each of the corresponding regions.

In addition, in the optical functional layer, 50% by volume or more, or 60% by volume or more, or 70% by volume or more, or more than the above values or 95% by volume or less of the total hollow inorganic nanoparticles from the particle mixture layer It may exist in a region up to one surface of the optical function layer facing the polymer resin layer. One surface of the optical function layer facing the polymer resin layer means the other surface positioned in the opposite direction to the surface in contact with the polymer resin layer.

As such, as the hollow inorganic nanoparticles are mainly distributed in the region from the particle mixed layer to one surface of the optical functional layer facing the polymer resin layer, the optical function from the particle mixed layer to the polymer resin layer facing The region up to one side of the layer may have a refractive index of 1.0 to 1.40 at a wavelength of 550 nm.

In the optical functional layer of the optical laminate, solid inorganic nanoparticles are mainly distributed near the interface between the polymer resin layer and the optical functional layer while the aforementioned particle mixed layer exists, and the hollow inorganic nanoparticles are located on the opposite side of the interface. Particles are mainly distributed, and a region in which each of the solid inorganic nanoparticles and the hollow inorganic nanoparticles are mainly distributed may form an independent layer in which the optical function layer is visually confirmed.

Specifically, among the optical functional layers of the optical laminate, solid inorganic nanoparticles are mainly distributed near the interface between the polymer resin layer and the optical functional layer, and hollow inorganic nanoparticles are mainly distributed toward the opposite surface of the interface. In this case, it is possible to achieve a lower reflectance compared to the actual reflectance previously obtained using inorganic particles, and greatly improved scratch resistance and antifouling properties can be realized together.

And, in the optical laminate of the embodiment, the region in which the solid inorganic nanoparticles and the hollow inorganic nanoparticles are ubiquitous in the optical functional layer is divided based on the particle mixed layer, and accordingly, the optical laminate has a wavelength of 550 nm. Although the reflectance of is less than 0.5%, the absolute value of b* value in the CIE Lab color space is less than 4, or less than 3, or less than 2, or less than 1.5. It can be reduced to a colorless and transparent property.

In addition, in the optical functional layer including the particle mixture layer, the volume ratio of the zirconium element to the silicon element in the region between 5 nm and 10 nm in thickness of the optical functional layer from the interface between the polymer resin layer and the optical functional layer is less than 2.6 , 0.5 to 2.0, 1.0 to 1.8, or 1.2 to 1.6.

In addition, in the region between 50 nm and 150 nm in thickness of the optical functional layer from the interface between the polymer resin layer and the optical functional layer, the volume ratio of the zirconium element to the silicon element is 1.62 or more, 1.70 to 2.5, 1.75 to 2.3, or 1.80 to 2.0 can be

The volume ratio of the zirconium element to the silicon element in the above-mentioned region may correspond to an arithmetic mean value of the volume ratio in the above-mentioned region.

In addition, since the volume ratio of the zirconium element to the silicon element in the above-mentioned region satisfies the above-mentioned range, it has a colorless and transparent characteristic while realizing a low reflectance, and further has a high transmittance and high scratch resistance and antifouling property at the same time.

If the volume ratio of the zirconium element to the silicon element is 2.6 or more in the region between 5 nm and 10 nm in thickness of the optical functional layer from the interface between the polymer resin layer and the optical functional layer, it is difficult to realize low reflectance or exhibits a colorless and transparent characteristic. It can be difficult to bet.

When the volume ratio of the zirconium element to the silicon element in the region of 50 nm to 150 nm in thickness of the optical functional layer from the interface between the polymer resin layer and the optical functional layer is less than 1.62, it is difficult to realize low reflectance or shows a colorless and transparent characteristic. It can be difficult to bet.

In addition, each of the regions between the one surface of the polymer resin layer and the mixed particle layer and the region from the particle mixed layer to the one surface of the optical functional layer facing the polymer resin layer may be divided into individual layers, as described above. The volume ratio of the silicon element and the zirconium element distributed in these individual layers can also be distinguished.

More specifically, when the ellipticity of the polarization measured by ellipsometry with respect to the region between the one surface of the polymer resin layer and the particle mixture layer is optimized with the Cauchy model of the following general formula 2 , where A is 1.00 to 1.65, B is 0.0010 to 0.0350, and C may satisfy the conditions of 0 to 1*10 ^-3 . In addition, with respect to the region between the one surface of the polymer resin layer and the particle mixed layer, the following A is 1.25 to 1.55, 1.30 to 1.52, or 1.45 to 1.51, and the following B is 0.0010 to 0.0150, 0.0010 to 0.0080, or 0.0010 to 0.0050 , and C below may satisfy a condition of 0 to 8.0*10 ^-4 , 0 to 5.0*10 ^-4 , or 0 to 4.1352*10 ^-4 .

[General formula 2]

In Formula 2, n(λ) is a refractive index at a wavelength of λ, λ is in the range of 300 nm to 1800 nm, and A, B and C are Cauchy parameters.

In addition, the ellipticity of the polarization measured by ellipsometry with respect to a region from the particle mixture layer to one surface of the optical functional layer opposite to the polymer resin layer was optimized with the Cauchy model of General Formula 2 above. When (fitting), A is 1.00 to 1.50, B is 0 to 0.007, and C may satisfy the conditions of 0 to 1*10 ^-3 . In addition, with respect to the region from the particle mixture layer to one surface of the optical function layer facing the polymer resin layer, A is 1.00 to 1.30, 1.00 to 1.20, 1.00 to 1.09, or 1.00 to 1.05, and B is 0 to 0.0060, 0 to 0.0055, or 0 to 0.00513, and C may satisfy a condition of 0 to 8*10 ^-4 , 0 to 5.0*10 ^-4 , or 0 to 4.8685*10 ^-4 .

In addition, when the ellipticity of the polarization measured by ellipsometry with respect to the particle mixed layer is optimized with the Cauchy model of Formula 2, A is 1.100 to 1.200, 1.130 to 1.199 , 1.150 to 1.198, or 1.180 to 1.195, B is 0 to 0.007, 0 to 0.006, 0 to 0.005, or 0 to 0.004, and C is 0 to 1*10 ^-3 _, 0 to 8*10 ^-4 , 0 to 5.0*10 ^-4 , or 0 to 4.8685*10 ^-4 may be satisfied.

On the other hand, each of the regions between the mixed particle layer and the polymer resin layer from one surface of the polymer resin layer and the region from the particle mixed layer to the one surface of the optical functional layer facing the polymer resin layer has a common optical characteristic within one layer. can be shared, and thus can be defined as one layer.

More specifically, each of the regions between the particle mixed layer and the polymer resin layer from one surface of the polymer resin layer to the particle mixed layer and the region from the particle mixed layer to the one surface of the optical functional layer opposite to the polymer resin layer is ellipsometry. When the ellipticity of the polarization measured by ) is optimized with the Cauchy model of Formula 2 above, it has specific Cauchy parameters A, B, and C, and thus each region can be distinguished from each other. In addition, since the thickness of each region can be derived by fitting the ellipticity of the polarization measured by the ellipsometry to the Cauchy model of Formula 2 above, in the optical functional layer Each area can be defined.

On the other hand, Cauchy parameters A, B, and C derived when the ellipticity of the polarization measured by the ellipsometry is optimized with the Cauchy model of Formula 2 above are calculated within one region. It may be an average value. Accordingly, when an interface exists between the respective regions, the Cauchy parameters A, B, and C of the respective regions may overlap. However, even in this case, the thickness and position of each of the regions may be specified according to the region satisfying the average values of the Cauchy parameters A, B, and C of each of the regions.

On the other hand, whether the hollow inorganic nanoparticles and solid inorganic nanoparticles exist in the specified region is determined by whether each hollow inorganic nanoparticles or solid inorganic nanoparticles exist in the specified region, , excluding particles existing across the boundary of the specific region.

The optical functional layer including the above-mentioned particle mixture layer may have a low average refractive index in the polymer resin layer, for example, the optical functional layer has an average refractive index of 1.46 or less, 1.43 or less, 1.40 or less, at a wavelength of 550 nm, or 1.39 to 1.30. In addition, the polymer resin layer may have an average refractive index of greater than 1.46, 1.47 or more, or 1.49 to 1.52 at a wavelength of 550 nm.

On the other hand, as described above, even in the optical function layer, 'the region between the one surface of the polymer resin layer and the particle mixed layer has a refractive index of 1.46 to 1.75 at a wavelength of 550 nm', and 'the polymer resin layer faces the polymer resin layer from the particle mixed layer' The region up to one surface of the optical functional layer to it means. Similarly, the average refractive index of the polymer resin layer also means an average value of the refractive indexes measured throughout the layer.

The specific distribution of the solid inorganic nanoparticles and the hollow inorganic nanoparticles in the optical functional layer is obtained by drying the photocurable resin composition for forming the optical functional layer including the nanoparticles in a specific manufacturing method to be described later at a drying temperature, drying Methods such as controlling the air volume, drying time, etc., and the above-described method for forming a mixed-particle layer may be obtained.

In order for the optical laminate to have a reflectance of 0.5% or less at a wavelength of 550 nm, a type having a large refractive index difference between the hollow inorganic nanoparticles and the solid inorganic nanoparticles may be selected.

More specifically, the difference in density between the solid inorganic nanoparticles and the hollow inorganic nanoparticles is 0.7 to 8.5 g/cm 3 , 0.8 to 7.5 g/cm 3 , 0.9 to 6.5 g/cm 3 , 1.1 to 5.5 g/cm 3 , It may be 1.20 to 4.5 g/cm 3 or 1.24 to 4.27 g/cm 3 .

When the difference in density between the solid inorganic nanoparticles and the hollow inorganic nanoparticles is too large, the solid inorganic nanoparticles are densely formed in the polymer resin layer and are separated from the region where the hollow inorganic nanoparticles are mainly distributed, or solid inorganic nanoparticles An intermediate layer having substantially no particles may be formed between the regions in which the nanoparticles and the hollow inorganic nanoparticles are mainly distributed. As such, the solid inorganic particles may be concentrated at the interface between the optical functional layer and the polymer resin layer, or the movement and localization of the particles may not be smooth during the optical functional layer formation process, and stains may occur on the surface of the optical functional layer or the optical functional layer The haze may be greatly increased and the transparency may be lowered.

In addition, when the difference in density between the solid inorganic nanoparticles and the hollow inorganic nanoparticles is too small, the above-mentioned solid inorganic nanoparticles and the hollow inorganic nanoparticles do not appear unevenly, so that the reflectance is greatly increased or the colorless and transparent characteristics are not displayed. it may not be

Therefore, the optical functional layer included in the optical laminate of the embodiment includes the inorganic particles having the above-described density difference, and can simultaneously implement high scratch resistance and antifouling properties while having high light transmittance, and low reflectance and haze. While being implemented, the black visual sensation may be improved, and colorless and transparent characteristics may be obtained.

More specifically, the solid inorganic nanoparticles may have a higher density than the hollow inorganic nanoparticles, for example, the solid inorganic nanoparticles are 1.2 to 10.5 g/cm 3 , 2.0 to 7.5 g/cm 3 Alternatively, it may have a density of 3.0 to 5.5 g/cm 3 , and the hollow inorganic nanoparticles are 0.50 g/cm 3 to 2.00 g/cm 3 , 0.70 g/cm 3 to 1.80 g/cm 3 or 1.00 g/cm 3 to 1.60 g/cm 3 can have a density of

The solid inorganic nanoparticles may include solid zirconia nanoparticles and solid silica nanoparticles. In this case, the solid zirconia nanoparticles may have a density of 3 to 7 g/cm 3 or 5 to 6 g/cm 3 , and the solid silica nanoparticles have a density of 2 to 4 g/cm 3 or 2.5 to 3.0 g/cm 3 can be

In addition, specific types of the hollow inorganic nanoparticles include hollow silica.

Meanwhile, the optical function layer may include the binder resin and hollow inorganic nanoparticles and solid inorganic nanoparticles dispersed in the binder resin.

The solid inorganic nanoparticles refer to particles having a maximum diameter of 100 nm or less and having no empty space therein.

In addition, the hollow inorganic nanoparticles refer to particles having a maximum diameter of 200 nm or less and having an empty space on the surface and/or inside thereof.

The solid inorganic nanoparticles may have a diameter of 0.5 to 100 nm, or 1 to 50 nm, or 5 to 30 nm, or 10 to 20 nm.

The hollow inorganic nanoparticles may have a diameter of 1 to 200 nm, or 10 to 100 nm, or 50 to 120 nm, or 30 to 90 nm, or 40 to 80 nm.

The diameter of the hollow inorganic nanoparticles and the diameter of the solid inorganic nanoparticles may be different.

In addition, the diameter of the hollow inorganic nanoparticles may be larger than the diameter of the solid inorganic nanoparticles.

The diameter of each of the solid inorganic nanoparticles and the hollow inorganic nanoparticles may mean the longest diameter of the nanoparticles identified in the cross-section.

On the other hand, each of the solid inorganic nanoparticles and the hollow inorganic nanoparticles has at least one reactivity selected from the group consisting of a (meth)acrylate group, an epoxide group, a vinyl group (Vinyl) and a thiol group (Thiol) on the surface It may contain functional groups. As each of the solid inorganic nanoparticles and the hollow inorganic nanoparticles contains the above-described reactive functional group on the surface, the optical functional layer may have a higher degree of crosslinking, thereby securing improved scratch resistance and antifouling properties can do.

The optical function layer may be obtained by applying the photocurable coating composition on a predetermined substrate and photocuring the applied result. The specific type or thickness of the substrate is not particularly limited, and a substrate known to be used for manufacturing an optical functional layer or an optical laminate may be used without major limitation.

Methods and apparatuses commonly used for applying the photocurable coating composition may be used without any other limitations, for example, bar coating method such as Meyer bar, gravure coating method, 2 roll reverse coating method, vacuum slot die coating method, 2 roll coating method, etc. can be used.

The optical function layer may have a thickness of 20 nm to 240 nm, or 50 nm to 200 nm, or 80 nm to 180 nm.

In the step of photocuring the photocurable coating composition, ultraviolet or visible light having a wavelength of 200 to 400 nm may be irradiated, and the exposure amount during irradiation is preferably 100 to 4,000 mJ/cm 2 . The exposure time is not particularly limited, either, and may be appropriately changed depending on the exposure apparatus used, the wavelength of the irradiation light, or the exposure amount.

In addition, in the step of photocuring the photocurable coating composition, nitrogen purging may be performed in order to apply nitrogen atmospheric conditions.

Meanwhile, the binder resin included in the optical functional layer may include a cross-linked (co)polymer between a (co)polymer of a photopolymerizable compound and a fluorine-containing compound including a photoreactive functional group.

The above-described optical functional layer may be prepared from a photocurable coating composition including a photopolymerizable compound, a fluorine-containing compound including a photoreactive functional group, hollow inorganic nanoparticles, solid inorganic nanoparticles, and a photoinitiator. Accordingly, the binder resin included in the optical functional layer may include a (co)polymer of a photopolymerizable compound and a crosslinked (co)polymer between a fluorine-containing compound including a photoreactive functional group.

Due to the hydrophobicity of the binder resin including the fluorine-containing compound and the hydrophilicity due to the high surface energy of the polymer resin layer, the speed at which the fluorine-containing compound moves to the surface of the coating layer during the drying process of the optical laminate may be affected. As a result, convection is formed in the solvent, and the fine particles evenly distributed in the solvent may exhibit different behaviors depending on the characteristics of the particles. In particular, in this process, each particle may form a plurality of different layers, and when evaporation of the solvent is finished during the formation of each layer, the above-mentioned particle mixed layer may be formed.

The surface rise of the fluorine-containing compound may induce the surface rise of the hollow inorganic nanoparticles, and the solid inorganic nanoparticles having a relatively small size may be less affected and phase separation of each particle may occur. As the solvent evaporates during the process and the fluidity of the particles disappears, the above-described mixed layer may be formed with a predetermined thickness in the optical functional layer.

The photopolymerizable compound may further include a fluorine-based (meth)acrylate-based monomer or oligomer in addition to the above-described monomers or oligomers. When the fluorine-based (meth)acrylate-based monomer or oligomer is further included, the weight ratio of the fluorine-based (meth)acrylate-based monomer or oligomer to the (meth)acrylate or vinyl group-containing monomer or oligomer is 0.1% to It can be 10%.

Specific examples of the fluorine-based (meth)acrylate-based monomer or oligomer include at least one compound selected from the group consisting of the following Chemical Formulas 11 to 15.

[Formula 11]

In Formula 11, R ¹ is a hydrogen group or an alkyl group having 1 to 6 carbon atoms, a is an integer of 0 to 7, and b is an integer of 1 to 3.

[Formula 12]

In Formula 12, c is an integer of 1 to 10.

[Formula 13]

In Formula 13, d is an integer of 1 to 11.

[Formula 14]

In Formula 14, e is an integer of 1 to 5.

[Formula 15]

In Formula 15, f is an integer of 4 to 10.

Meanwhile, the optical functional layer may include a portion derived from the fluorine-containing compound including the photoreactive functional group.

One or more photoreactive functional groups may be included or substituted in the fluorine-containing compound including the photoreactive functional group, and the photoreactive functional group may participate in a polymerization reaction by irradiation of light, for example, by irradiation of visible light or ultraviolet light. It means that there is a functional group. The photoreactive functional group may include various functional groups known to participate in the polymerization reaction by irradiation of light, and specific examples thereof include a (meth)acrylate group, an epoxide group, a vinyl group (Vinyl) or a thiol group ( Thiol) can be mentioned.

Each of the fluorine-containing compounds including the photoreactive functional group may have a weight average molecular weight (weight average molecular weight in terms of polystyrene measured by GPC method) of 2,000 to 200,000, preferably 5,000 to 100,000.

If the weight average molecular weight of the fluorine-containing compound including the photoreactive functional group is too small, the fluorine-containing compounds in the photocurable coating composition cannot be uniformly and effectively arranged on the surface and are located inside the finally manufactured optical functional layer. Accordingly, the antifouling property of the surface of the optical functional layer may be lowered and the crosslinking density of the optical functional layer may be lowered, and thus mechanical properties such as overall strength and scratch resistance may be reduced.

In addition, if the weight average molecular weight of the fluorine-containing compound including the photoreactive functional group is too high, compatibility with other components in the photocurable coating composition may be lowered, and thus the haze of the finally manufactured optical functional layer may be increased or The light transmittance may be lowered, and the strength of the optical functional layer may also be lowered.

Specifically, the fluorine-containing compound including the photoreactive functional group includes: i) an aliphatic compound or an aliphatic ring compound in which at least one photoreactive functional group is substituted and at least one carbon is substituted with at least one fluorine; ii) a heteroaliphatic compound or a heteroaliphatic ring compound substituted with one or more photoreactive functional groups, wherein at least one hydrogen is substituted with fluorine and one or more carbons are substituted with silicon; iii) a polydialkylsiloxane-based polymer (eg, polydimethylsiloxane-based polymer) in which one or more photoreactive functional groups are substituted and in which at least one silicone is substituted with one or more fluorine; iv) a polyether compound substituted with one or more photoreactive functional groups and at least one hydrogen substituted with fluorine, or a mixture of two or more of i) to iv) or a copolymer thereof.

The photocurable coating composition may include 20 to 300 parts by weight of the fluorine-containing compound including the photoreactive functional group based on 100 parts by weight of the photopolymerizable compound.

When the fluorine-containing compound including the photoreactive functional group is added in excess compared to the photopolymerizable compound, the coatability of the photocurable coating composition of the embodiment is reduced or the optical functional layer obtained from the photocurable coating composition has sufficient durability or scratch resistance may not have In addition, if the amount of the fluorine-containing compound including the photoreactive functional group compared to the photopolymerizable compound is too small, the optical functional layer obtained from the photocurable coating composition may not have sufficient mechanical properties such as antifouling properties or scratch resistance.

The fluorine-containing compound including the photoreactive functional group may further include silicon or a silicon compound. That is, the fluorine-containing compound including the photoreactive functional group may optionally contain silicon or a silicon compound therein, and specifically, the content of silicon in the fluorine-containing compound including the photoreactive functional group is 0.1 wt% to 20 wt% can

The silicon included in the fluorine-containing compound including the photoreactive functional group can increase compatibility with other components included in the photocurable coating composition of the embodiment, and thus haze is prevented from occurring in the finally manufactured refractive layer. It can play a role in increasing transparency by preventing it. On the other hand, if the content of silicon in the fluorine-containing compound including the photoreactive functional group is too large, compatibility between other components included in the photocurable coating composition and the fluorine-containing compound may be rather deteriorated, and thus the final manufactured optical Since the functional layer or the optical laminate may not have sufficient light transmittance or antireflection performance, the antifouling property of the surface may also be deteriorated.

The optical function layer may be included in an amount of 10 to 400 parts by weight, 20 to 350 parts by weight, or 50 to 300 parts by weight of the hollow inorganic nanoparticles relative to 100 parts by weight of the (co)polymer of the photopolymerizable compound. In addition, the optical functional layer may be included in an amount of 10 to 400 parts by weight, 20 to 350 parts by weight, or 50 to 300 parts by weight of the solid inorganic nanoparticles relative to 100 parts by weight of the (co)polymer of the photopolymerizable compound.

When the content of the hollow inorganic nanoparticles and the solid inorganic nanoparticles in the optical functional layer is excessive, the phase separation between the hollow inorganic nanoparticles and the solid inorganic nanoparticles does not occur sufficiently during the manufacturing process of the optical functional layer and is mixed. As a result, the reflectance may be increased, and the surface unevenness may be excessively generated, thereby reducing the antifouling property. In addition, when the content of the hollow inorganic nanoparticles and the solid inorganic nanoparticles in the optical functional layer is too small, a plurality of the solid inorganic nanoparticles in a region close to the interface between the polymer resin layer and the optical functional layer It may be difficult to locate, and the reflectance of the optical functional layer may be greatly increased.

Each of the hollow inorganic nanoparticles and the solid inorganic nanoparticles may be included in the composition in a colloidal form dispersed in a predetermined dispersion medium. Each colloidal phase including the hollow inorganic nanoparticles and the solid inorganic nanoparticles may include an organic solvent as a dispersion medium.

The colloidal phase of each of the hollow inorganic nanoparticles and the solid inorganic nanoparticles in consideration of the content range of each of the hollow inorganic nanoparticles and the solid inorganic nanoparticles in the photocurable coating composition or the viscosity of the photocurable coating composition The medium content may be determined, for example, the solid content of each of the hollow inorganic nanoparticles and the solid inorganic nanoparticles in the colloidal phase may be 5% to 60% by weight.

Here, as the organic solvent in the dispersion medium, alcohols such as methanol, isopropyl alcohol, ethylene glycol, butanol; ketones such as methyl ethyl ketone and methyl isobutyl ketone; aromatic hydrocarbons such as toluene and xylene; dimethylformamide. amides such as dimethylacetamide and N-methylpyrrolidone; esters such as ethyl acetate, butyl acetate, and gamma butyrolactone; ethers such as tetrahydrofuran and 1,4-dioxane; Or a mixture thereof may be included.

As the photopolymerization initiator, any compound known to be used in the photocurable resin composition can be used without major limitation, and specifically, a benzophenone-based compound, an acetophenone-based compound, a biimidazole-based compound, a triazine-based compound, an oxime-based compound, or A mixture of two or more thereof may be used.

Based on 100 parts by weight of the photopolymerizable compound, the photopolymerization initiator may be used in an amount of 1 to 100 parts by weight. If the amount of the photopolymerization initiator is too small, an uncured material remaining in the photocuring step of the photocurable coating composition may be issued. If the amount of the photopolymerization initiator is too large, the unreacted initiator may remain as an impurity or the crosslinking density may be lowered, so that mechanical properties of the produced film may be reduced or reflectance may be greatly increased.

Meanwhile, the photocurable coating composition may further include an organic solvent.

Non-limiting examples of the organic solvent include ketones, alcohols, acetates and ethers, or a mixture of two or more thereof.

Specific examples of such an organic solvent include ketones such as methyl ethyl kenone, methyl isobutyl ketone, acetylacetone or isobutyl ketone; alcohols such as methanol, ethanol, diacetone alcohol, n-propanol, i-propanol, n-butanol, i-butanol, or t-butanol; acetates such as ethyl acetate, i-propyl acetate, and polyethylene glycol monomethyl ether acetate; ethers such as tetrahydrofuran or propylene glycol monomethyl ether; or a mixture of two or more thereof.

The organic solvent may be added at the time of mixing each component included in the photocurable coating composition, or may be included in the photocurable coating composition while each component is added in a dispersed or mixed state in the organic solvent. If the content of the organic solvent in the photocurable coating composition is too small, the flowability of the photocurable coating composition is lowered, and defects such as streaks may occur in the finally manufactured film. In addition, when an excessive amount of the organic solvent is added, the solid content is lowered, and coating and film formation are not sufficiently performed, so that physical properties or surface properties of the film may be deteriorated, and defects may occur during drying and curing. Accordingly, the photocurable coating composition may include an organic solvent such that the concentration of the total solid content of the components included is 1% to 50% by weight, or 2 to 20% by weight.

On the other hand, the optical laminate of the embodiment, a photocurable compound or a (co)polymer thereof, a fluorine-containing compound including a photoreactive functional group, a photoinitiator, a resin for forming an optical function layer including hollow inorganic nanoparticles and solid inorganic nanoparticles Applying the composition on the polymer resin layer and drying at a temperature of 35 ℃ to 100 ℃; and photocuring the dried product of the resin composition; may be provided through a method of manufacturing an optical laminate comprising a.

The optical function layer is a photocurable compound or a (co)polymer thereof, a fluorine-containing compound including a photoreactive functional group, a photoinitiator, a resin composition for forming an optical function layer including hollow inorganic nanoparticles and solid inorganic nanoparticles A polymer resin layer It can be formed by coating on the top and drying at a temperature of 35 °C to 100 °C, or 40 °C to 80 °C.

If the drying temperature of the resin composition for forming an optical functional layer applied on the polymer resin layer is less than 35° C., the antifouling property of the optical functional layer to be formed may be greatly reduced. In addition, if the drying temperature of the resin composition for forming an optical functional layer applied on the polymer resin layer is greater than 100° C., phase separation between the hollow inorganic nanoparticles and the solid inorganic nanoparticles in the optical functional layer manufacturing process is sufficient. It does not occur and is mixed, and not only the scratch resistance and antifouling properties of the optical functional layer are deteriorated, but also the reflectance may be greatly increased.

In the process of drying the resin composition for forming an optical function layer applied on the polymer resin layer, the optical function having the above-described characteristics by controlling the density difference between the solid inorganic nanoparticles and the hollow inorganic nanoparticles together with the drying temperature layer can be formed.

Meanwhile, the drying of the resin composition for forming an optical function layer applied on the polymer resin layer at a temperature of 35° C. to 100° C. may be performed for 10 seconds to 5 minutes, or 30 seconds to 4 minutes.

When the drying time is too short, the phase separation between the solid inorganic nanoparticles and the hollow inorganic nanoparticles may not sufficiently occur. On the other hand, when the drying time is too long, the optical function layer to be formed may erode the polymer resin layer.

The polymer resin layer may have a thickness of 0.1 μm to 100 μm.

As an example of the polymer resin layer, a polymer resin layer including a binder resin including a photocurable resin and organic or inorganic fine particles dispersed in the binder resin.

The photocurable resin included in the polymer resin layer is a polymer of a photocurable compound that can cause a polymerization reaction when irradiated with light such as ultraviolet light, and may be conventional in the art. Specifically, the photocurable resin may include a reactive acrylate oligomer group consisting of a urethane acrylate oligomer, an epoxide acrylate oligomer, a polyester acrylate, and a polyether acrylate; and dipentaerythritol hexaacrylate, dipentaerythritol hydroxy pentaacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, trimethylene propyl triacrylate, propoxylated glycerol triacrylate, trimethylpropane ethoxy tri At least one selected from the group consisting of polyfunctional acrylate monomers consisting of acrylate, 1,6-hexanediol diacrylate, propoxylated glycero triacrylate, tripropylene glycol diacrylate, and ethylene glycol diacrylate. may include

The organic or inorganic fine particles are not specifically limited in particle size, but for example, the organic fine particles may have a particle size of 1 to 10 μm, and the inorganic particles may have a particle size of 1 nm to 500 nm, or 1 nm to 300 nm. can have The particle diameter of the organic or inorganic fine particles may be defined as a volume average particle diameter.

In addition, specific examples of the organic or inorganic fine particles included in the polymer resin layer are not limited, but for example, the organic or inorganic fine particles are organic fine particles made of an acrylic resin, a styrene resin, an epoxide resin, and a nylon resin, or silicon oxide , titanium dioxide, indium oxide, tin oxide, zirconium oxide and may be inorganic fine particles consisting of zinc oxide.

The binder resin of the polymer resin layer may further include a high molecular weight (co)polymer having a weight average molecular weight of 10,000 or more.

The high molecular weight (co)polymer may be at least one selected from the group consisting of a cellulose-based polymer, an acrylic polymer, a styrene-based polymer, an epoxide-based polymer, a nylon-based polymer, a urethane-based polymer, and a polyolefin-based polymer.

On the other hand, as another example of the polymer resin layer, a binder resin of a photocurable resin; and a polymer resin layer comprising an antistatic agent dispersed in the binder resin.

The photocurable resin included in the polymer resin layer is a polymer of a photocurable compound that can cause a polymerization reaction when irradiated with light such as ultraviolet light, and may be conventional in the art. However, preferably, the photocurable compound may be a polyfunctional (meth)acrylate-based monomer or oligomer, wherein the number of (meth)acrylate-based functional groups is 2 to 10, preferably 2 to 8, more preferably Preferably, it is 2 to 7, which is advantageous in terms of securing the physical properties of the polymer resin layer. More preferably, the photocurable compound is pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipenta Erythritol hepta(meth)acrylate, tripentaerythritol hepta(meth)acrylate, torylene diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, trimethylolpropane tri(meth)acrylate, and trimethylolpropane polyethoxy It may be at least one selected from the group consisting of tri (meth) acrylate.

The antistatic agent is a quaternary ammonium salt compound; pyridinium salts; cationic compounds having 1 to 3 amino groups; anionic compounds such as sulfonic acid bases, sulfuric acid ester bases, phosphoric acid ester bases and phosphonic acid bases; an amphoteric compound such as an amino acid-based compound or an amino sulfuric acid ester-based compound; nonionic compounds such as imino alcohol compounds, glycerin compounds, and polyethylene glycol compounds; organometallic compounds such as metal alkoxide compounds containing tin or titanium; metal chelate compounds such as acetylacetonate salts of the above organometallic compounds; two or more reactants or polymers of these compounds; It may be a mixture of two or more of these compounds. Here, the quaternary ammonium salt compound may be a compound having one or more quaternary ammonium salt groups in the molecule, and a low molecular type or a high molecular type may be used without limitation.

In addition, as the antistatic agent, a conductive polymer and metal oxide fine particles can also be used. Examples of the conductive polymer include aromatic conjugated poly(paraphenylene), heterocyclic conjugated polypyrrole, polythiophene, aliphatic conjugated polyacetylene, heteroatom-containing conjugated polyaniline, mixed type conjugated poly( phenylene vinylene), a double-chain conjugated compound having a plurality of conjugated chains in the molecule, and a conductive composite obtained by grafting or block copolymerizing a conjugated polymer chain to a saturated polymer. In addition, examples of the metal oxide fine particles include zinc oxide, antimony oxide, tin oxide, cerium oxide, indium tin oxide, indium oxide, aluminum oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, and the like.

a binder resin of the photocurable resin; And the polymer resin layer comprising an antistatic agent dispersed in the binder resin may further include at least one compound selected from the group consisting of alkoxysilane-based oligomers and metal alkoxide-based oligomers.

The alkoxysilane-based compound may be conventional in the art, but preferably tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methacryloxypropyl It may be at least one compound selected from the group consisting of trimethoxysilane, glycidoxypropyl trimethoxysilane, and glycidoxypropyl triethoxysilane.

In addition, the metal alkoxide-based oligomer may be prepared through a sol-gel reaction of a composition including a metal alkoxide-based compound and water. The sol-gel reaction may be performed by a method similar to the method for preparing an alkoxysilane-based oligomer described above.

However, since the metal alkoxide-based compound may react rapidly with water, the sol-gel reaction may be performed by slowly dropping water after diluting the metal alkoxide-based compound in an organic solvent. At this time, in consideration of reaction efficiency, etc., it is preferable to adjust the molar ratio of the metal alkoxide compound to water (based on metal ions) within the range of 3 to 170.

Here, the metal alkoxide-based compound may be at least one compound selected from the group consisting of titanium tetra-isopropoxide, zirconium isopropoxide, and aluminum isopropoxide.

The optical laminate may further include a light-transmitting base layer formed on the other surface of the polymer resin layer to face the optical functional layer.

The light-transmitting base layer may have a transmittance of 50% or more, 75% or more, 85% or more, or 95% or more at a wavelength of 300 nm or more.

The light-transmitting base layer may include a transparent plastic resin. Specific examples of the plastic resin include polyester-based resins, cellulose-based resins, polycarbonate-based resins, acrylic resins, styrene-based resins, polyolefin-based resins, polyimide-based resins, polyethersulfone-based resins, or sulfone-based resins. and any one or a mixture of two or more thereof may be used.

More specifically, the light-transmitting base layer is polyethylene terephthalate (polyethyleneterephtalate, PET), cyclic olefin copolymer (COC), polyacrylate (PAC), polycarbonate (polycarbonate, PC), polyethylene (polyethylene, PE), polymethylmethacrylate (PMMA), polyetheretherketon (PEEK), polyethylenenaphthalate (PEN), polyetherimide (PEI), polyimide, PI), polyamideimide (PAI), and triacetylcellulose (TAC).

On the other hand, the light-transmitting base layer may be a single layer, or may have a multi-layer structure of two or more layers made of the same or different materials. In one example, the support substrate is a multilayer structure of polyethylene terephthalate (PET), a multilayer structure formed by coextrusion of polymethyl methacrylate (PMMA)/polycarbonate (PC), or polymethyl methacrylate (PMMA) and It may be a single-layer structure including a copolymer of polycarbonate (PC).

In addition, the light-transmitting base layer may be plasma surface-treated if necessary, and the method is not specifically suggested and may be performed according to a conventional method.

In addition, when the thickness of the light-transmitting base layer is excessively thick or thin, there are problems in surface hardness, lowering of impact resistance, or folding characteristics, and it may be preferable to appropriately set the range. For example, the light-transmitting substrate may have a thickness of 20 to 200 μm, 30 to 150 μm, or 50 to 120 μm.

According to another embodiment of the present invention, a polarizing plate including the optical laminate may be provided.

The polarizing plate may include a polarizer and an optical laminate formed on at least one surface of the polarizer.

The material and manufacturing method of the polarizer are not particularly limited, and conventional materials and manufacturing methods known in the art may be used. For example, the polarizer may be a polyvinyl alcohol-based polarizer.

The polarizer and the optical laminate may be laminated by an adhesive such as a water-based adhesive or a non-aqueous adhesive.

According to another embodiment of the present invention, a display device including the above-described optical laminate may be provided.

Specific examples of the display device are not limited, and may be, for example, a liquid crystal display device, a plasma display device, an organic light emitting diode display device, a flexible display device, or the like.

In the display device, the optical laminate may be provided on the outermost surface of the viewer side or the backlight side of the display panel.

In the display device including the optical laminate, the optical laminate may be positioned on one surface of the polarizing plate that is relatively far from the backlight unit among the pair of polarizing plates.

In addition, the display device may include a display panel, a polarizer provided on at least one surface of the panel, and an optical laminate provided on an opposite surface of the polarizer in contact with the panel.

According to another embodiment of the present invention, an organic light emitting diode display device including the optical laminate may be provided.

In general, an organic light emitting diode display device has high resolution and high color reproducibility. In the case of an optical laminate having a high color value, for example, an absolute value of b* in the CIE Lab color space is greater than 4, the color of the organic light emitting diode display device It may reduce the reproducibility.

In contrast, the optical laminate of the embodiment may have a colorless and transparent characteristic because the absolute value of b* in the CIE Lab color space is as low as 4 or less while realizing high transmittance and low reflectance, and thus the organic light emitting diode An effect of maintaining or increasing the color reproducibility of the display device may be implemented.

According to the present invention, it is possible to simultaneously implement high scratch resistance and antifouling properties while having high light transmittance, and while implementing low reflectivity and haze, the black visual perception is improved, and an optical laminate having colorless and transparent characteristics, a polarizing plate including the same, and a display A device and an organic light emitting diode display device may be provided.

1 is a photograph taken with a transmission electron microscope (TEM) of a cross section of the optical laminate of Example 1.
2 is a photograph of a cross-section of the optical laminate of Comparative Example 1 taken with a transmission electron microscope.
3 is a photograph of a cross-section of the optical laminate of Comparative Example 2 taken with a transmission electron microscope.
4 is a graph showing reflectance for each wavelength of Example 1, Comparative Example 1, and Comparative Example 2;
5 is a graph showing the results of infrared spectroscopy analysis of the binder of the optical functional layer of Example 1 and Comparative Example 1. FIG.

The invention is described in more detail in the following examples. However, the following examples only illustrate the present invention, and the content of the present invention is not limited by the following examples.

Preparation Example 1: Preparation of polymer resin layer

A coating solution for forming a polymer resin layer was prepared by diluting the solid content of LAS-1467KR (Toyo-ink) in a cyclohexanone solvent to have a solid content concentration of 40 wt%. The diluted coating solution for forming a polymer resin layer was coated on a triacetyl cellulose film with #10 mayer bar, dried at an ultraviolet intensity of 25 mJ/cm ² , and photocured while purging with nitrogen, a polymer resin layer having a thickness of 4 μm was prepared.

Example 1: Preparation of an optical laminate

(1) Preparation of a photocurable coating composition for manufacturing an optical function layer

Based on 100 parts by weight of trimethylolpropane ethoxylate triacrylate (M3190, Miwon yarn), hollow silica nanoparticles (diameter: about 70 to 80 nm, density: 1.41 g/cm 3 , JSC catalyst and chemicals) 297 Part by weight, solid zirconia nanoparticles (diameter: about 11 nm, density: 5.68 g/cm 3 , Daiken) 1326 parts by weight, solid silica nanoparticles (diameter: about 10 to 15 nm, density: 2.65 g/cm 3 , Nissan chemical) 51.75 parts by weight, first fluorine-containing compound (KY-1207, ShinEtsu Corporation) 183 parts by weight, second fluorine-containing compound (RS-4137, Aekyung Chemical) 74.5 parts by weight, initiator (SPI-02, Samyang Corporation) 12.9 parts by weight of methyl isobutyl ketone (MIBK): diacetone alcohol (DAA): isopropyl alcohol (IPA): methyl ethyl ketone (MEK): ethanol (EtOH) in a weight ratio of 26.32: 6.12: 24.23: 25.33: 9.49 It was diluted so that it might become 8 weight% of solid content concentration in the mixed solvent.

(2) Manufacture of optical function layer and optical laminated body

On the polymer resin layer of Preparation Example 1, the photocurable coating composition obtained above was coated to have a thickness of about 150 nm with #4 mayer bar, and dried for 1 minute at a wind speed of 0.5 m/s or more and a temperature of 90 ° C. , was cured while purging with nitrogen at an ultraviolet intensity of 254 mJ/cm ² .

<Comparative Example: Preparation of an optical laminate>

Comparative Example 1

An optical laminate was prepared in the same manner as in Example 1, except that dipentaerythritol hexaacrylate (DPHA) was used instead of trimethylolpropane ethoxylate triacrylate.

Comparative Example 2

An optical laminate was manufactured in the same manner as in Example 1, except that the power of the exhaust facility was turned off during the drying process.

<Experimental Example: Measurement of physical properties of optical laminates>

The following experiments were performed on the optical laminates obtained in Examples and Comparative Examples, and the results are shown in Table 1 below.

1. Measurement of surface energy of polymer resin layer

For the surface energy of each polymer resin layer in Examples and Comparative Examples, the contact angles of di-water (Gebhardt) and di-iodomethane (Owens) were measured at 10 points using Kruss's DSA-100 contact angle measuring equipment and averaged after The average contact angle was measured in terms of surface energy. In the measurement of the surface energy, Dropshape Analysis software was used and the following general formula 1 of the OWRK (Owen, Wendt, Rable, Kaelble) method was applied to the program to convert the contact angle into surface energy.

[General formula 1]

2. Measurement of average reflectance of optical laminates and a*value and b*value in CIE Lab color space

For the optical laminates obtained in Examples and Comparative Examples, reflectance, a* value, and b* value at each wavelength in the visible light region (380 to 780 nm) were measured using Solidspec 3700 (SHIMADZU) equipment. After measuring the reflectance at each wavelength by scanning the specimen from wavelength 380 to 780 nm, the average reflectance, a* value, and b* value were derived using UV-2401PC Color Analysis program.

3. Scratch resistance measurement

A load was applied to the steel wool (#0000), and the surface of the optical laminate obtained in Examples and Comparative Examples was rubbed while reciprocating 10 times at a speed of 27 rpm. The maximum load at which one scratch of 1 cm or less observed with the naked eye was observed was measured.

4 Measurement of reflectance

With respect to the particle mixture layer included in the optical functional layer obtained in Examples and Comparative Examples, elliptically polarized light measured at a wavelength of 380 nm to 1,000 nm and a Cauchy model at a wavelength of 550 nm, a wavelength of 400 nm, and a wavelength of 700 nm, respectively was calculated.

5 Infrared spectroscopy

The optical functional layer of the Examples and Comparative Examples was subjected to IR measurement with a Cary 660 (Agilent Corporation) device, and in the derived IR spectrum, the area of the peak present in the region of 1710 to 1780 cm ^-1 (A ₁ ) The ratio (A ₂ /A ₁ ) of the area (A ₂ ) of the peak present in the region of 2860 to 2880 cm ^-1 was calculated. The results are shown as 'infrared spectroscopy peak area ratio' in Table 1 below.

At this time, the IR measurement conditions are as follows.

- ATR: PIKE Technologies 025-2018 Miracle Znse perf crystal plate (Ge, 65º)

- Measuring wavelength: 400 to 4000 nm

- Measuring temperature: 25℃

5 is a graph showing the results of infrared spectroscopic analysis of the binder of the optical functional layer of Example 1 and Comparative Example 3, the analysis result of Example 1 is B-1, and the analysis result of Comparative Example 1 is A-1.

Example 1 Comparative Example 1 Comparative Example 2 Average Reflectance (%) 0.7 2 3.3 a*value in CIE Lab color space 1.8 2.9 -4.8 b*value in CIE Lab color space -0.7 -9.6 -3.8 Surface energy of polymer resin layer [mN/m] 39.1 39.1 39.1 Reflectance at a wavelength of 550 nm of the optical laminate 0.1726 0.2346 2.8589 Reflectance at a wavelength of 400 nm of the optical laminate 0.626 0.633 1.710 Reflectance at a wavelength of 700 nm of the optical laminate 1.5818 1.6753 2.151 scratch resistance 100 gf 100 gf 50 gf Phase separation Great usually Inadequate Infrared spectroscopy peak area ratio 0.119 0.066 -

As shown in Table 1, a (meth) acrylate-based resin containing an alkylene oxide having 1 to 3 carbon atoms is included as a binder resin, and particles including hollow inorganic nanoparticles and solid inorganic nanoparticles are mixed The optical functional layer of the embodiment in which the layer is present in the optical functional layer has a low color value of 2 or less in absolute values of a* and b* in the CIE Lab color space while implementing a reflectance of 0.2% or less at a wavelength of 550 nm. It has been confirmed that it can have colorless and transparent properties.

In addition, the optical laminate of the embodiment includes a particle mixture layer in the optical functional layer and phase-separated so that the region where the hollow inorganic nanoparticles and the solid inorganic nanoparticles are mainly distributed, high scratch resistance and excellent antifouling properties, , and it was confirmed that the absolute values of a* and b* in the CIE Lab color space had a low color value of 2 or less, so that it had colorless and transparent properties and realized excellent scratch resistance.

In contrast, Comparative Example 1 does not include a (meth)acrylate-based resin including an alkylene oxide having 1 to 3 carbon atoms as a binder resin, so the absolute value of a* and the absolute value of b* in the CIE Lab color space are More than 2, it was confirmed that it exhibited a degree of opacity (high haze) or chromaticity that was not suitable for application to a polarizing plate or a display device.

In addition, Comparative Example 2 is divided into regions in which hollow inorganic nanoparticles and solid inorganic nanoparticles are mainly distributed, respectively, and is not ubiquitous (phase separation), indicating reduced scratch resistance, and the absolute value of a* in the CIE Lab color space It was confirmed that the absolute value of the value and b* exceeded 2, indicating opacity (high haze) or chromaticity.

Claims (22)

polymer resin layer; and
An optical functional layer formed on one surface of the polymer resin layer and including a binder resin, hollow inorganic nanoparticles, and solid inorganic nanoparticles;
A particle mixture layer including the hollow inorganic nanoparticles and the solid inorganic nanoparticles is present in the optical functional layer,
The binder resin included in the optical functional layer is an optical laminate comprising a (meth)acrylate-based resin containing an alkylene oxide having 1 to 3 carbon atoms.
According to claim 1,
The particle mixture layer is positioned at a distance of 50 nm or more from the interface between the polymer resin layer and the optical functional layer.
According to claim 1,
The solid inorganic nanoparticles include solid silica nanoparticles and solid zirconia nanoparticles, an optical laminate.
According to claim 1,
The particle mixture layer has a thickness of 25 to 100 nm, an optical laminate.
According to claim 1,
When the ellipticity of the polarization measured by ellipsometry with respect to the particle mixed layer is optimized with the Cauchy model of Formula 2 below, A is 1.100 to 1.200, and B is 0 to 0.007 and C is 0 to 1*10 ^-3 , the optical laminate:
[General formula 2]

In Formula 2, n(λ) is a refractive index at a wavelength of λ, λ is in the range of 300 nm to 1800 nm, and A, B and C are Cauchy parameters.
According to claim 1,
wherein the optical function layer has a thickness of 20 to 240 nm.
According to claim 1,
The optical laminate has a reflectance of 0.5% or less at a wavelength of 550 nm.
According to claim 1,
The ratio of the reflectance at a wavelength of 400 nm to the reflectance at a wavelength of 550 nm of the optical laminate is 5 or more, the optical laminate.
According to claim 1,
The polymer resin layer has a surface energy of 34 mN/m or more, an optical laminate.
According to claim 1,
The polymer resin layer has an average refractive index greater than 1.46 at a wavelength of 550 nm,
The optical function layer has an average refractive index of 1.46 or less at a wavelength of 550 nm.
According to claim 1,
In the optical functional layer, 50% by volume or more of the total of the solid inorganic nanoparticles is present between one surface of the polymer resin layer and the particle mixture layer.
According to claim 1,
A region between the one surface of the polymer resin layer and the mixed particle layer has a refractive index of 1.46 to 1.75 at a wavelength of 550 nm, an optical laminate.
According to claim 1,
In the optical functional layer, 50% by volume or more of the total hollow inorganic nanoparticles are present in a region from the particle mixed layer to one surface of the optical functional layer facing the polymer resin layer.
According to claim 1,
A region from the particle mixture layer to one surface of the optical functional layer facing the polymer resin layer has a refractive index of 1.0 to 1.40 at a wavelength of 550 nm.
According to claim 1,
The solid inorganic nanoparticles have a diameter of 0.5 to 100 nm,
The hollow inorganic nanoparticles have a diameter of 1 to 200 nm, an optical laminate.
According to claim 1,
The difference in density between the solid inorganic nanoparticles and the hollow inorganic nanoparticles is 0.7 to 8.5 g/cm 3 , the optical laminate.
According to claim 1,
The binder resin included in the optical functional layer further comprises a fluorine-containing compound including a photoreactive functional group, the optical laminate.
According to claim 1,
The polymer resin layer includes a binder resin including a photocurable resin, and organic or inorganic fine particles dispersed in the binder resin.
According to claim 1,
The optical laminate further comprising a light-transmitting base layer formed on the other surface of the polymer resin layer to face the optical functional layer.
A polarizing plate comprising the optical laminate of claim 1 and a polarizer.
A display device comprising the optical laminate of claim 1 .
An organic light emitting diode display device comprising the optical laminate of claim 1 .

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