Anti-reflective film

Abstract

The present invention relates to an antireflection film that includes a hard coat layer and a low refractive index layer, wherein the low refractive index layer contains a particle-mixed layer having a thickness of 1.5 nm to 22 nm, the particle-mixed layer containing hollow inorganic nanoparticles and solid inorganic nanoparticles, and the ratio of the reflectance at a wavelength of 400 nm to the reflectance at a wavelength of 550 nm is 1.3 to 2.7, a polarizing plate that includes the antireflection film, a display device, and an organic light-emitting diode display device.

Description

[Technical Field]

[0001] [Cross-reference of related applications] This application claims the benefit of priority under Korean Patent Application No. 10-2020-0032251 dated March 16, 2020, Korean Patent Application No. 10-2020-0032253 dated March 16, 2020, Korean Patent Application No. 10-2021-0033696 dated March 16, 2021, and Korean Patent Application No. 10-2021-0033702 dated March 16, 2021, and all content disclosed in the documents of said Korean Patent Applications is incorporated herein as part of this specification.

[0002] The present invention relates to an anti-reflective film, a polarizing plate, a display device, and an organic light-emitting diode display device. [Background technology]

[0003] Generally, flat-panel display devices such as PDPs and LCDs are fitted with anti-reflective films to minimize the reflection of light incident from the outside.

[0004] Methods to minimize light reflection include coating a resin with inorganic microparticles or other fillers to create an uneven surface (anti-glare: AG coating); forming multiple layers with different refractive indices on the substrate film to utilize light interference (anti-reflection: AR coating); or combining these methods.

[0005] In the case of the aforementioned AG coating, the absolute amount of reflected light is at the same level as that of a general hard coating, but a low-reflectivity effect can be obtained by reducing the amount of light entering the eye by utilizing the scattering of light through the surface irregularities. However, because the AG coating reduces the clarity of the screen due to the surface irregularities, a lot of research has recently been done on AR coatings.

[0006] As for films utilizing the aforementioned AR coating, commercially available films have a multilayer structure in which a hard coat layer (high refractive index layer), a low-reflection coating layer, etc., are laminated on a base film. However, this method of forming multiple layers has the disadvantage that the interlayer adhesion (interfacial adhesion) is weak and the scratch resistance is reduced because the process of forming each layer is carried out separately.

[0007] Furthermore, conventional methods have mainly involved adding various nanometer-sized particles (for example, silica, alumina, zeolite, etc.) to improve the scratch resistance of the low-refractive index layer contained in anti-reflective films. However, as mentioned above, when using nanometer-sized particles, there are limitations to simultaneously lowering the reflectivity of the low-refractive index layer and improving its scratch resistance, and the antifouling properties of the surface of the low-refractive index layer are greatly reduced by the nanometer-sized particles.

[0008] As a result, much research has been conducted to improve surface scratch resistance and stain resistance while reducing the absolute amount of light reflected from the outside, but the degree of improvement in physical properties achieved by these methods is currently insufficient. [Overview of the project] [Problems that the invention aims to solve]

[0009] The present invention provides an anti-reflective film that has high light transmittance, high scratch resistance and stain resistance simultaneously, and is colorless and transparent while achieving low reflectivity.

[0010] Furthermore, the present invention provides a polarizing plate including the anti-reflective film.

[0011] Furthermore, the present invention provides a display device that includes the anti-reflective film.

[0012] Furthermore, the present invention provides an organic light-emitting diode display device that includes the anti-reflective film.

Means for Solving the Problems

[0013] The present invention provides an antireflection film including a hard coat layer and a low refractive index layer, containing hollow inorganic nanoparticles and solid inorganic nanoparticles, having a particle-mixed layer with a thickness of 1.5 nm to 22 nm present in the low refractive index layer, and having a ratio of the reflectance at a wavelength of 400 nm to the reflectance at a wavelength of 550 nm of 1.3 to 2.7.

[0014] Further, the present invention provides a polarizing plate including the antireflection film and a polarizer.

[0015] Further, the present invention provides a display device including the antireflection film.

[0016] Further, the present invention provides an organic light-emitting diode display device including the antireflection film.

[0017] Hereinafter, the antireflection film, polarizing plate, display device, and organic light-emitting diode display device according to specific embodiments of the invention will be described in more detail.

[0018] In the present specification, a photopolymerizable compound is a general term for a compound that undergoes a polymerization reaction when irradiated with light, for example, visible light or ultraviolet light.

[0019] Further, a fluorine-containing compound means a compound containing at least one or more fluorine elements in the compound.

[0020] Further, (meth)acrylate means including both acrylate and methacrylate.

[0021] Further, (co)polymer means including both copolymer and homopolymer.

[0022] Furthermore, "silica hollow particles" refers to silica particles derived from silicon compounds or organosilicon compounds, wherein empty spaces exist on the surface and / or inside the silica particles.

[0023] Furthermore, the low refractive index layer refers to a layer within the anti-reflective film that has a lower refractive index compared to other layers, such as the hard coat layer.

[0024] For example, the low refractive index layer may have a refractive index of 1.65 or less, or 1.60 or less, or 1.57 or less, or 1.55 or less, or 1.53 or less at a wavelength of 550 nm.

[0025] According to one embodiment of the invention, an anti-reflective film is provided, comprising a hard coat layer and a low refractive index layer, wherein a particle mixture layer comprising hollow inorganic nanoparticles and solid inorganic nanoparticles and having a thickness of 1.5 nm to 22 nm is present within the low refractive index layer, and the ratio of the reflectance at a wavelength of 400 nm to the reflectance at a wavelength of 550 nm is 1.3 to 2.7.

[0026] When an anti-reflective film containing a low refractive index layer and a hard coat layer has a low refractive index, for example, a reflectance of 1.5% or less at a wavelength of 550 nm, the reflectance in the blue region becomes higher than the reflectance in the green region. This causes the anti-reflective layer to take on a bluish tint, which may result in opacity or coloration that makes it unsuitable for application to polarizing plates or display devices.

[0027] Therefore, the inventors conducted research on anti-reflective films and, through experiments, confirmed that by including hollow inorganic nanoparticles and solid inorganic nanoparticles within the low-refractive index layer of the anti-reflective film, and forming a mixed layer of particles having a predetermined thickness, it is possible to achieve low reflectivity while significantly reducing the degree of blue tint and achieving colorless transparency, thus completing the invention. Furthermore, the anti-reflective film has the above-mentioned characteristics, as well as high light transmittance, and simultaneously achieves high scratch resistance and stain resistance.

[0028] As described above, the presence of the particle-mixed layer allows the anti-reflective film to have a low reflectivity while maintaining colorless transparency. Therefore, the low-refractive-index layer, by containing hollow inorganic nanoparticles and solid inorganic nanoparticles, can have high light transmittance and simultaneously achieve high scratch resistance and stain resistance.

[0029] Specifically, the ratio of the reflectance at a wavelength of 400 nm to the reflectance at a wavelength of 550 nm of the anti-reflective film may be 1.3 to 2.7, or 1.5 to 2.5.

[0030] The anti-reflective film 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 1.3 to 2.7, or 1.5 to 2.5, or 1.40 to 2.30. As a result, the anti-reflective film can have optical properties in which the reflectance in the blue region is lower than the reflectance in the green region, and therefore can have colorless and transparent properties while achieving low reflectance.

[0031] If the ratio of the reflectance at a wavelength of 400 nm to the reflectance at a wavelength of 550 nm of the anti-reflective film exceeds 2.7, the anti-reflective film will take on a bluish tint and may have an opacity or coloriness that makes it unsuitable for application to polarizing plates or display devices. In particular, an anti-reflective film with a ratio of reflectance at a wavelength of 400 nm to the reflectance at a wavelength of 550 nm exceeding 2.7 may reduce the color reproduction capability of an organic light-emitting diode display device.

[0032] The ratio of the reflectance at a wavelength of 400 nm to the reflectance at a wavelength of 550 nm of the anti-reflective film is in the range of 1.3 to 2.7, the reflectance at a wavelength of 550 nm of the anti-reflective film is greater than 0.5% and less than or equal to 1.5%, or 0.55% to 1.35%, or 0.59% to 1.32%, and the reflectance at a wavelength of 400 nm of the anti-reflective film may be 1.0% to 3.50%, or 1.20% to 2.60%.

[0033] On the other hand, the anti-reflective film includes a particle-mixed layer having a predetermined thickness within the low-refractive index layer, and the ratio of the reflectance at a wavelength of 400 nm to the reflectance at a wavelength of 550 nm of the anti-reflective film is 1.3 to 2.7, or 1.5 to 2.5, thereby the anti-reflective film may have the characteristic that the absolute value of b* in the CIE Lab color space is 4 or less, or 3 or less, or 2 or less, or 1.5 or less.

[0034] More specifically, the anti-reflective film may include the particle-containing layer within the low-refractive index layer and have the characteristic that the absolute value of b* in the CIE Lab color space is 4 or less, or 3 or less, or 2 or less, or 1.5 or less.

[0035] Each numerical value in the CIE Lab color space can be measured by applying a general method for measuring each coordinate in the color space. For example, it can be measured according to the manufacturer's manual after positioning a spectrophotometer (e.g., CM-2600d, manufactured by Konica Minolta) with an integrating sphere-shaped detector at the measurement position. As an example, each coordinate in the CIE Lab color space can be measured with the polarizer or polarizing plate attached to a liquid crystal panel, for example, the high-reflectance liquid crystal panel, or it can be measured relative to the polarizer or polarizing plate itself.

[0036] The aforementioned CIE Lab color space is a color space obtained by non-linearly transforming the CIE XYZ color space based on the antagonistic theory of human vision. In this color space, the L* value indicates brightness; an L* value of 0 indicates black, and an L* value of 100 indicates white. Furthermore, a negative a* value results in a color biased towards green, and a positive a* value results in a color biased towards red. Similarly, a negative b* value results in a color biased towards blue, and a positive b* value results in a color biased towards yellow.

[0037] In other words, the anti-reflective film has the characteristic of having an absolute value of 4 or less, or 3 or less, or 2 or less, or 1.5 or less in the CIE Lab color space, thereby achieving low reflectivity while significantly reducing the degree of red or green tint and possessing the characteristic of being colorless and transparent.

[0038] More specifically, the anti-reflective film may have a reflectance at a wavelength of 550 nm that is greater than 0.5% and less than or equal to 1.5%, or between 0.55% and 1.35%, or between 0.59% and 1.32%, and while achieving such a low reflectance, it may also have the characteristic of having an absolute value of 4 or less, or 3 or less, or 2 or less, or 1.5 or less in the CIE Lab color space.

[0039] In this way, by achieving low reflectivity while maintaining a low absolute value of the b* value in the CIE Lab color space, the anti-reflective film can be easily applied to displays with high contrast ratios and brightness, and can achieve high color reproduction performance.

[0040] In order to have the above-described characteristics of the anti-reflective film, the low refractive index layer may contain a particle mixture layer having a thickness of 1.5 nm to 22 nm, or 2.0 nm to 20 nm, or 2.2 nm to 18.5 nm, which includes hollow inorganic nanoparticles and solid inorganic nanoparticles.

[0041] If the thickness of the particle-mixed layer is too thin, cancellation interference within the anti-reflective layer may not occur sufficiently, and the absolute value of the b* may exceed 4.

[0042] Furthermore, if the thickness of the particle-containing layer is too thick, the absolute value of the b* value in the CIE Lab color space of the anti-reflective film may exceed 4, and therefore, the optical properties of the anti-reflective film, such as transparency, may deteriorate.

[0043] On the other hand, as described above, the particle mixture layer includes hollow inorganic nanoparticles and solid inorganic nanoparticles, and the volume ratio and distribution of these are not significantly limited.

[0044] The refractive index and thickness of the particle-mixed layer can be confirmed by various optical measurement methods. For example, they can be confirmed by optimizing (fitting) the ellipticity of the polarization measured by polarization analysis (ellipsometry) using a diffuse layer model.

[0045] The ellipticity of the polarization and related data (Ellipsometry data (Ψ, Δ)) measured by the aforementioned polarization analysis method (ellipsometry) can be measured using known methods and apparatus. For example, for the particle-mixed layer or other regions contained in the low-refractive-index layer, linear polarization can be measured in the wavelength range of 380 nm to 1000 nm using the M-2000 instrument manufactured by JAWoollam, with an incident angle of 70°.

[0046] The measured linear polarization measurement data (Ellipsometry data (Ψ, Δ)) can be optimized (fitted) using Complete EASE software by dividing the mixed layer into two layers: the lower layer using a diffuse layer model and the upper layer using the Cauchy model of General Equation 1 below, so that the MSE is 5 or less.

[0047] For the particle mixture layer containing the hollow inorganic nanoparticles and solid inorganic nanoparticles, its thickness and other properties cannot be defined by optimizing the measured linear polarization measurement data using the Cauchy model of General Equation 1 below.

[0048] When the thickness and refractive index range of the particle-containing layer contained in the low-refractive-index layer satisfy the above range, the abrupt difference in refractive index between each layer is mitigated, thereby enabling the anti-reflective film to achieve low reflectivity while maintaining a low absolute value of the b* in the CIE Lab color space.

[0049] On the other hand, a particle-mixed layer can be formed within the low-refractive-index layer by adjusting the composition of the binder resin contained in the low-refractive-index layer, the type and content of the particles, the specific process during the formation of the low-refractive-index layer (for example, the coating speed, coating method, or drying conditions), and the characteristics of the hard coat layer.

[0050] Such examples are merely illustrative of methods and means for forming the particle-containing layer, and even if the above methods and means are used simultaneously, the particle-containing layer will not be formed within the low-refractive-index layer. This can be adjusted by the fine materials forming the low-refractive-index layer and their content, the thickness of the low-refractive-index layer, the fine materials of the hard coat layer and their content, the surface properties and thickness of the hard coat layer, and so on. In other words, the presence of the particle-containing layer within the low-refractive-index layer and the effects associated therewith can be realized based on the descriptions and embodiments of this specification.

[0051] For example, the hard coat layer included in the anti-reflective film may include a binder resin containing a photocurable resin and organic or inorganic fine particles dispersed in the binder resin. When a low refractive index layer containing a binder resin, hollow inorganic nanoparticles, and solid inorganic nanoparticles is formed on such a hard coat layer under predetermined conditions, the particle mixture layer may be present.

[0052] Furthermore, the hard coat layer included in the anti-reflective film may have a surface energy greater than 34 mN / m, greater than 34 mN / m and 60 mN / m or less, 34.2 mN / m or more and 59 mN / m or less, 34.5 mN / m or more and 58 mN / m or less, or 35 mN / m to 55 mN / m. When a binder resin and a low refractive index layer containing hollow inorganic nanoparticles and solid inorganic nanoparticles are formed on a hard coat layer having a surface energy in such a range, the aforementioned particle mixture layer is formed during the optimization process of surface energy within the low refractive index layer due to the high surface energy of the interface.

[0053] The surface energy of the hard coat layer can be obtained by adjusting the surface properties of the hard coat layer. For example, the surface energy of the hard coat layer can be adjusted by adjusting the degree of surface hardening, drying conditions, etc.

[0054] Specifically, the degree of hardening of the hard coat layer can be adjusted by adjusting the curing conditions during the formation of the hard coat layer, such as the amount or intensity of light irradiation or the flow rate of injected nitrogen. For example, the hard coat layer is formed in a nitrogen-purged state to apply nitrogen atmospheric conditions, with the resin composition forming the hard coat layer treated with 5 to 100 mJ / cm³. 2 , or 10-25 mJ / cm² 2 It is obtained by irradiating with ultraviolet light at this exposure level.

[0055] The aforementioned surface energy can be measured by first measuring the contact angles of di-water (Gebhardt) and di-iodomethane (Owens) at 10 points using a known measuring device, such as the DSA-100 contact angle measuring device manufactured by Kruss, obtaining the average value, and then converting the average contact angle into surface energy. Specifically, in measuring the surface energy, Drop Shape Analysis software can be used, and the following general formula 2 of the OWRK (Owen, Wendt, Rable, Kaelble) method can be applied to the program to convert the contact angle into surface energy.

number

[0056] Furthermore, as described later, the particle-mixed layer is formed by applying drying temperature, airflow control, etc., when forming the low-refractive-index layer.

[0057] Specifically, the airflow rate during the drying process can be adjusted by controlling the drying conditions, such as the intake or exhaust volume, during the formation of the low-refractive-index layer. For example, the airflow rate during the drying process after coating the low-refractive-index layer can be 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.

[0058] More specifically, the low refractive index layer is formed on one surface of the hard coat layer, and the particle-containing layer may be located at a distance of 12 nm or more, or 15 nm to 60 nm, or 16 nm to 50 nm from one surface of the hard coat layer.

[0059] The distance between the particle-mixed layer and one surface of the hard coat layer is not particularly limited, but the particle-mixed layer, when located at a distance of 12 nm or more from one surface of the hard coat layer, plays a role in mitigating the abrupt difference in refractive index between layers within the low-refractive-index layer, thereby reducing the absolute value of the slope of the reflectance pattern at short wavelengths.

[0060] When the particle-containing layer is located in a region less than 12 nm from one surface of the hard coat layer, the effect of mitigating the difference in refractive index between layers within the low-refractive-index layer is limited, and therefore the absolute value of the slope of the reflectance pattern cannot be sufficiently determined.

[0061] The distance between the particle-containing layer and the hard coat layer can be the shortest distance between one surface of the hard coat layer and the particle-containing layer, with respect to the surface direction of the hard coat layer. Alternatively, the distance between the particle-containing layer and the hard coat layer can be defined by the thickness of the region between one surface of the hard coat layer and the particle-containing layer.

[0062] The existence of a region between one surface of the hard coat layer and the particle-mixed layer can be confirmed by polarization analysis (ellipsometry). When the ellipticity of the polarization measured by polarization analysis (ellipsometry) for each of the particle-mixed layer and the region between one surface of the hard coat layer and the particle-mixed layer is optimized using the Cauchy model of general equation 1 below, it will have specific Cauchy parameters A, B, and C, and therefore, the particle-mixed layer and the region between one surface of the hard coat layer and the particle-mixed layer are each separated from each other.

[0063] Specifically, the linear polarization can be measured in the low refractive index layer in the wavelength range of 380 nm to 1000 nm by applying an incident angle of 70° using the M-2000 instrument manufactured by JAWoollam. The measured linear polarization measurement data (Ellipsometry data (Ψ, Δ)) can be optimized (fitted) to the low refractive index layer or the fine layers within the low refractive index layer using the Cauchy model of General Equation 1 below, using Complete EASE software.

number

[0064] In the above general formula 1, n(λ) is the refractive index at wavelength λ, λ is in the range of 300 nm to 1800 nm, and A, B, and C are Cauchy parameters.

[0065] Furthermore, by optimizing (fitting) the ellipticity of the polarization measured by the polarization analysis method (ellipsometry) using the Cauchy model and the Diffuse Layer Model of General Equation 1, the thicknesses of the regions between one surface of the particle-mixed layer and the hard coat layer can also be derived, thus allowing each of the regions between one surface of the particle-mixed layer and the hard coat layer to be defined within the low-refractive-index layer.

[0066] More specifically, the low refractive index layer is formed on one surface of the hard coat layer, and the low refractive index layer may contain hollow inorganic nanoparticles and solid inorganic nanoparticles dispersed in a binder resin, in which case 50% or more, 60% or more, 70% or more, or above or below the above values, or 95% or less of the total solid inorganic nanoparticles may be present in the low refractive index layer between one surface of the hard coat layer and the particle mixture layer.

[0067] Thus, since the solid inorganic nanoparticles are mainly distributed in the region between one surface of the hard coat layer and the particle-mixed layer, the region between one surface of the hard coat layer and the particle-mixed layer has a refractive index of 1.46 to 1.65 at a wavelength of 550 nm.

[0068] "50% or more of the total solid inorganic nanoparticles are present in a specific region" is defined as meaning that in the cross-section of the low refractive index layer, almost all of the solid inorganic nanoparticles are present in the specific region. Specifically, 70% or more of the total solid inorganic nanoparticles can be confirmed by measuring the total volume of the solid inorganic nanoparticles.

[0069] For example, it is possible to visually confirm that the regions where solid inorganic nanoparticles and hollow inorganic nanoparticles are mainly distributed are located within the low-refractive-index layer. For example, using a transmission electron microscope or scanning electron microscope, it is possible to visually confirm that individual layers or regions are located within the low-refractive-index layer, and it is also possible to confirm the ratio of solid inorganic nanoparticles and hollow inorganic nanoparticles distributed in each layer or region within the low-refractive-index layer.

[0070] Furthermore, in the low refractive index layer, 50% or more by volume, or 60% or more by volume, or 70% or more by volume, or the above values ​​or 95% or less of the total hollow inorganic nanoparticles, may be present in the region from the particle mixture layer to one surface of the low refractive index layer facing the hard coat layer. The one surface of the low refractive index layer facing the hard coat layer means the other surface located in the opposite direction to the surface in contact with the hard coat layer.

[0071] Thus, the hollow inorganic nanoparticles are mainly distributed in the region from the particle mixture layer to one surface of the low refractive index layer facing the hard coat layer, and the region from the particle mixture layer to one surface of the low refractive index layer facing the hard coat layer has a refractive index of 1.0 to 1.40 at a wavelength of 550 nm.

[0072] In the low refractive index layer of the anti-reflective film, the above-mentioned particle mixture layer exists, and solid inorganic nanoparticles are mainly distributed near the interface between the hard coat layer and the low refractive index layer, while hollow inorganic nanoparticles are mainly distributed on the opposite side of the interface. However, separate layers can be formed within the low refractive index layer, where regions mainly distributed by solid inorganic nanoparticles and hollow inorganic nanoparticles are visibly observed.

[0073] Specifically, when solid inorganic nanoparticles are mainly distributed near the interface between the hard coat layer and the low refractive index layer of the anti-reflective film, and hollow inorganic nanoparticles are mainly distributed on the opposite side of the interface, a lower reflectivity can be achieved compared to the actual reflectivity previously obtained using inorganic particles, thereby achieving significantly improved scratch resistance and antifouling properties.

[0074] Furthermore, in the anti-reflective film of the above embodiment, regions in which solid inorganic nanoparticles and hollow inorganic nanoparticles are unevenly distributed within the low refractive index layer are separated with respect to the particle mixture layer. As a result, the anti-reflective film has a reflectance of more than 0.5% and 1.5% or less at a wavelength of 550 nm, 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, or 1.5 or less. Therefore, while achieving low reflectance, it is possible to significantly reduce the degree of blue tint and have the characteristic of being colorless and transparent.

[0075] Furthermore, the region between one surface of the hard coat layer and the particle-mixed layer, and the region from the particle-mixed layer to one surface of the low-refractive index layer facing the hard coat layer, are each divided into separate layers, and as described above, the ratio of solid inorganic nanoparticles and hollow inorganic nanoparticles distributed in these separate layers can also be divided.

[0076] More specifically, when the ellipticity of the polarization measured by polarization analysis (ellipsometry) for the region between one surface of the hard coat layer and the particle mixture layer is optimized (fitted) using the Cauchy model of the following general formula 1, A is 1.00 to 1.65, B is 0.0010 to 0.0350, and C is 0 to 1*10. -3 The conditions are met.

[0077] Furthermore, for the region between one surface of the hard coat layer and the particle-mixed layer, A is 1.25~1.55, 1.30~1.53, or 1.40~1.52, B is 0.0010~0.0150, 0.0010~0.0080, or 0.0010~0.0050, and C is 0~8.0*10 -4 , 0~5.0*10 -4 , or 0~4.1352*10 -4 The conditions are met.

number

[0078] In the general formula 1, n(λ) is the refractive index at the wavelength λ, λ ranges from 300 nm to 1800 nm, and A, B, and C are Cauchy parameters.

[0079] Also, when the ellipticity of polarization measured by ellipsometry for the region from the particle-mixed layer to one surface of the low-refractive-index layer facing the hard coat layer is optimized (fitted) with the Cauchy model of the general formula 1, A is 1.00 to 1.50, B is 0 to 0.007, and C is 0 to 1*10 -3 satisfies the conditions.

[0080] Also, for the region from the particle-mixed layer to one surface of the optical functional layer facing the polymer resin layer, A is 1.00 to 1.40, 1.00 to 1.39, 1.00 to 1.38, or 1.00 to 1.37, and B is 0 to 0.0060, 0 to 0.0055, or 0 to 0.00513, and C is 0 to 8*10 -4 , 0 to 5.0*10 -4 or 0 to 4.8685*10 -4 satisfies the conditions.

[0081] On the other hand, each of the particle-mixed layer, the region between the one surface of the hard coat layer and the particle-mixed layer, and the region from the particle-mixed layer to one surface of the low-refractive-index layer facing the hard coat layer can share common optical properties within one layer, and thus can be defined as one layer.

[0082] More specifically, the particle-mixed layer, the region between one surface of the hard coat layer and the particle-mixed layer, and the region from the particle-mixed layer to one surface of the low-refractive-index layer facing the hard coat layer each have specific Cauchy parameters A, B, and C when the ellipticity of the polarization measured by polarization analysis (ellipsometry) is optimized (fitted) using the Cauchy model of General Equation 1, thereby distinguishing the first and second layers from each other. Furthermore, since the thickness of each layer is also derived by optimizing (fitting) the ellipticity of the polarization measured by polarization analysis (ellipsometry) using the Cauchy model of General Equation 1, each layer can be defined within the low-refractive-index layer.

[0083] On the other hand, when the ellipticity of the polarization measured by the polarization analysis method (ellipsometry) is optimized (fitted) using the Cauchy model of general equation 1, the derived Cauchy parameters A, B, and C may be average values ​​within a single layer. Therefore, if an interface exists between each of the layers, there may be a region that overlaps with the Cauchy parameters A, B, and C of each of the layers. However, even in such cases, the thickness and position of each layer can be determined according to the region that satisfies the average values ​​of the Cauchy parameters A, B, and C of each of the layers.

[0084] Furthermore, whether or not the hollow inorganic nanoparticles and solid inorganic nanoparticles are present in a specific region is determined by whether or not particles of each hollow inorganic nanoparticle or solid inorganic nanoparticle exist within the specific region, and the determination is made excluding particles that exist across the interface of the specific region.

[0085] The specific distribution of solid inorganic nanoparticles and hollow inorganic nanoparticles in the low refractive index layer is obtained by adjusting the density difference between the solid inorganic nanoparticles and hollow inorganic nanoparticles using a specific manufacturing method described later, adjusting the drying temperature of the photocurable resin composition for forming the low refractive index layer containing the two types of nanoparticles, and by the method for forming the particle mixture layer described above.

[0086] Specifically, the solid inorganic nanoparticles have a concentration of 0.50 g / cm³ compared to the hollow inorganic nanoparticles. 3 It has a density higher than the above, and the density difference between the solid inorganic nanoparticles and the hollow inorganic nanoparticles is 0.50 g / cm³. 3 ~3.00g / cm 3 , or 0.50 g / cm³ 3 ~2.50g / cm 3 , or 0.50 g / cm³ 3 ~2.00g / cm 3 , or 0.60 g / cm³ 3 ~2.00g / cm 3 It is possible.

[0087] Due to this density difference, the solid inorganic nanoparticles in the low refractive index layer formed on the hard coat layer may be located even closer to the hard coat layer.

[0088] However, if the density difference between the solid inorganic nanoparticles and the hollow inorganic nanoparticles is too large, the solid inorganic particles may concentrate and be unevenly distributed at the interface between the low refractive index layer and the hard coat layer, or the movement and uneven distribution of particles may not proceed smoothly during the formation process of the low refractive index layer, which may cause stains to occur on the surface of the low refractive index layer, or the haze of the low refractive index layer may increase significantly, reducing its transparency.

[0089] Specific examples of the solid inorganic nanoparticles mentioned above include zirconia, titania, antimony pentoxide, silica, or tin oxide.

[0090] Furthermore, specific types of hollow inorganic nanoparticles include hollow silica.

[0091] On the other hand, the low refractive index layer may include a binder resin, and hollow inorganic nanoparticles and solid inorganic nanoparticles dispersed in the binder resin.

[0092] The photopolymerizable compound contained in the photocurable coating composition of the above embodiment can form the substrate of the binder resin of the low refractive index layer to be produced.

[0093] Specifically, the photopolymerizable compound may include monomers or oligomers containing (meth)acrylate or vinyl groups. More specifically, the photopolymerizable compound may include monomers or oligomers containing one or more, two or more, or three or more (meth)acrylate or vinyl groups.

[0094] Specific examples of monomers or oligomers containing the (meth)acrylate include pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tolylene diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, trimethylolpropane tri(meth)acrylate, trimethylolpropane polyethoxytri(meth)acrylate, trimethylolpropane trimethacrylate, ethylene glycol dimethacrylate, butanediol dimethacrylate, hexaethyl methacrylate, butyl methacrylate, or mixtures of two or more of these, or urethane-modified acrylate oligomers, epoxy acrylate oligomers, ether acrylate oligomers, tendritic acrylate oligomers, or mixtures of two or more of these. In this case, the weight-average molecular weight of the oligomer is preferably 1,000 to 10,000.

[0095] Specific examples of monomers or oligomers containing the aforementioned vinyl group include divinylbenzene, styrene, or paramethylstyrene.

[0096] The content of the photopolymerizable compound in the photocurable coating composition is not particularly limited, but considering the mechanical properties of the low refractive index layer and anti-reflective film ultimately produced, the content of the photopolymerizable compound in the solid content of the photocurable coating composition may be 5% to 80% by weight. The solid content of the photocurable coating composition refers only to the solid components, excluding the liquid components in the photocurable coating composition, such as organic solvents that are selectively included as described later.

[0097] The solid inorganic nanoparticles mentioned above have a maximum diameter of 100 nm or less and are particles in which there are no empty spaces inside.

[0098] Furthermore, the hollow inorganic nanoparticles refer to particles having a maximum diameter of 200 nm or less and having empty spaces on their surface and / or inside.

[0099] The solid inorganic nanoparticles have a diameter of 0.5 to 100 nm, or 1 to 50 nm, or 5 to 30 nm, or 10 to 20 nm.

[0100] The hollow inorganic nanoparticles 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.

[0101] The diameter of the hollow inorganic nanoparticles may differ from the diameter of the solid inorganic nanoparticles.

[0102] Furthermore, the diameter of the hollow inorganic nanoparticles may be larger than the diameter of the solid inorganic nanoparticles.

[0103] The diameters of the solid inorganic nanoparticles and the hollow inorganic nanoparticles refer to the longest diameter of the nanoparticles observed in cross-section.

[0104] On the other hand, each of the solid inorganic nanoparticles and the hollow inorganic nanoparticles may contain one or more reactive functional groups selected from the group consisting of (meth)acrylate groups, epoxide groups, vinyl groups, and thiol groups on its surface. By containing the above-mentioned reactive functional groups on the surface of each of the solid inorganic nanoparticles and the hollow inorganic nanoparticles, the low refractive index layer can have a higher degree of crosslinking, thereby ensuring further improved scratch resistance and antifouling properties.

[0105] The low refractive index layer is obtained by applying the photocurable coating composition onto a predetermined substrate and photocuring the resulting product. The specific type and thickness of the substrate are not particularly limited, and any substrate commonly used in the manufacture of a low refractive index layer or anti-reflective film can be used without any particular restriction.

[0106] Methods and apparatus commonly used for applying the aforementioned photocurable coating composition can be used without particular limitation. For example, bar coating methods such as Meyer bar coating, gravure coating, 2-roll reverse coating, vacuum slot die coating, and 2-roll coating can be used.

[0107] The low refractive index layer may have a thickness of 20 nm to 240 nm, 50 nm to 200 nm, or 80 nm to 180 nm.

[0108] In the step of photocuring the aforementioned photocurable coating composition, ultraviolet or visible light with a wavelength of 200 to 400 nm can be irradiated, and the exposure dose during irradiation is 100 to 4,000 mJ / cm². 2 It is preferable that this is the case. The exposure time is not particularly limited and can be appropriately changed depending on the exposure apparatus used, the wavelength of the irradiated light, or the amount of exposure.

[0109] Furthermore, during the photocuring stage of the photocurable coating composition, nitrogen purging or the like can be performed to apply nitrogen atmosphere conditions.

[0110] On the other hand, the binder resin contained in the low refractive index layer may include a crosslinked (co)polymer between a photopolymerizable compound and a fluorine-containing compound containing a photoreactive functional group.

[0111] The low refractive index layer described above is produced from a photocurable coating composition comprising a photopolymerizable compound, a fluorine-containing compound containing a photoreactive functional group, hollow inorganic nanoparticles, solid inorganic nanoparticles, and a photoinitiator. As a result, the binder resin contained in the low refractive index layer may include a crosslinked (co)polymer between the photopolymerizable compound and the fluorine-containing compound containing a photoreactive functional group.

[0112] The hydrophobicity of the binder resin containing the aforementioned fluorine-containing compound and the hydrophilicity of the hard coat layer due to its high surface energy influence the rate at which the fluorine-containing compound acts on the coating layer surface during the drying process of the anti-reflective film. This creates convection in the solvent, and the fine particles, which were uniformly dispersed in the solvent, can exhibit different movements depending on the properties of the particles. In particular, each particle can form multiple distinct layers during this process, and if the evaporation of the solvent stops during the formation of each layer, the aforementioned particle-mixed layer is formed.

[0113] The surface elevation of the fluorine-containing compound can induce the surface elevation of hollow inorganic nanoparticles. Solid inorganic nanoparticles, which have a relatively small size, are less affected and can undergo phase separation of each particle. However, as the evaporation of the solvent during this process ends, the particles lose their fluidity, and as a result, the aforementioned mixed layer is formed within the low refractive index layer with a predetermined thickness.

[0114] The photopolymerizable compound may further contain a fluorine-based (meth)acrylate monomer or oligomer in addition to the monomer or oligomer described above. When the fluorine-based (meth)acrylate monomer or oligomer is further included, the weight ratio of the fluorine-based (meth)acrylate monomer or oligomer to the monomer or oligomer containing the (meth)acrylate or vinyl group may be 0.1% to 10%.

[0115] Specific examples of the aforementioned fluorine-based (meth)acrylate monomers or oligomers include one or more compounds selected from the group consisting of the following chemical formulas 11 to 15. [ka] In the above chemical formula 11, R 1 is hydrogen or an alkyl group having 1 to 6 carbon atoms, a is an integer from 0 to 7, and b is an integer from 1 to 3. [ka] In the above chemical formula 12, c is an integer between 1 and 10. [ka] In the above chemical formula 13, d is an integer between 1 and 11. [ka] In the above chemical formula 14, e is an integer between 1 and 5. [ka] In the aforementioned chemical formula 15, f is an integer between 4 and 10.

[0116] On the other hand, the low refractive index layer includes a portion derived from a fluorine-containing compound containing the photoreactive functional group.

[0117] The fluorine-containing compound containing the aforementioned photoreactive functional group contains or is substituted with one or more photoreactive functional groups, where the photoreactive functional group is a functional group that can participate in a polymerization reaction upon irradiation with light, for example, visible light or ultraviolet light. The photoreactive functional group can include a variety of functional groups known to be able to participate in a polymerization reaction upon irradiation with light, and specific examples include (meth)acrylate groups, epoxide groups, vinyl groups, or thiol groups.

[0118] Each of the fluorine-containing compounds containing the aforementioned photoreactive functional group may have a weight-average molecular weight (weight-average molecular weight in polystyrene terms, measured by GPC) of 2,000 to 200,000, preferably 5,000 to 100,000.

[0119] If the weight-average molecular weight of the fluorine-containing compound containing the photoreactive functional group is too small, the fluorine-containing compound may not be able to arrange uniformly and effectively on the surface of the photocurable coating composition and may end up inside the low refractive index layer that is ultimately produced. This can reduce the antifouling properties of the surface of the low refractive index layer, decrease the crosslinking density of the low refractive index layer, and consequently reduce the overall strength and mechanical properties such as scratch resistance.

[0120] Furthermore, if the weight-average molecular weight of the fluorine-containing compound containing the photoreactive functional group is too high, the compatibility with other components in the photocurable coating composition will decrease, which may result in increased haze or decreased light transmittance of the final low-refractive-index layer, and may also decrease the strength of the low-refractive-index layer.

[0121] Specifically, the fluorine-containing compounds containing the photoreactive functional groups include: i) an aliphatic or alicyclic compound in which one or more photoreactive functional groups are substituted and at least one carbon atom is substituted with one or more fluorines; ii) a heteroaliphatic or heteroalicyclic compound in which one or more photoreactive functional groups are substituted, at least one hydrogen atom is substituted with fluorine, and one or more carbon atoms are substituted with silicon; iii) a polydialkylsiloxane polymer (e.g., a polydimethylsiloxane polymer) in which one or more photoreactive functional groups are substituted and at least one silicon atom is substituted with one or more fluorines; iv) a polyether compound in which one or more photoreactive functional groups are substituted and at least one hydrogen atom is substituted with fluorine, or a mixture of two or more of i) to iv), or copolymers thereof.

[0122] The photocurable coating composition may contain 20 to 300 parts by weight of a fluorine-containing compound containing the photoreactive functional group, per 100 parts by weight of the photopolymerizable compound.

[0123] If an excessive amount of the fluorine-containing compound containing the photoreactive functional group is added to the photopolymerizable compound, the coating properties of the photocurable coating composition of the embodiment may decrease, or the low refractive index layer obtained from the photocurable coating composition may not have sufficient durability or scratch resistance. Conversely, if the amount of the fluorine-containing compound containing the photoreactive functional group is too small relative to the photopolymerizable compound, the low refractive index layer obtained from the photocurable coating composition may not have sufficient mechanical properties such as antifouling or scratch resistance.

[0124] The fluorine-containing compound having the photoreactive functional group may further contain silicon or a silicon compound. In other words, the fluorine-containing compound having the photoreactive functional group may selectively contain silicon or a silicon compound internally, and specifically, the silicon content in the fluorine-containing compound having the photoreactive functional group may be 0.1% to 20% by weight.

[0125] The silicon contained in the fluorine-containing compound containing the photoreactive functional group can enhance compatibility with other components in the photocurable coating composition of the embodiment, thereby preventing haze from forming in the final refractive layer and improving transparency. On the other hand, if the silicon content in the fluorine-containing compound containing the photoreactive functional group is too high, the compatibility between the fluorine-containing compound and other components in the photocurable coating composition will decrease, which may result in the final low refractive layer or anti-reflective film not having sufficient light transmittance or anti-reflective performance, and the surface's anti-fouling properties may also decrease.

[0126] The low refractive index layer may contain 10 to 500 parts by weight, 50 to 480 parts by weight, or 200 to 400 parts by weight of the hollow inorganic nanoparticles per 100 parts by weight of the (co)polymer of the photopolymerizable compound.

[0127] The low refractive index layer may contain 10 to 400 parts by weight, 50 to 380 parts by weight, 80 to 300 parts by weight, or 100 to 250 parts by weight of the solid inorganic nanoparticles per 100 parts by weight of the (co)polymer of the photopolymerizable compound.

[0128] The low refractive index layer may contain the hollow inorganic nanoparticles and the solid inorganic nanoparticles in relatively higher concentrations than those found in low refractive index layers in known optical films.

[0129] If the content of hollow inorganic nanoparticles and solid inorganic nanoparticles in the low refractive index layer is too high, the phase separation between the hollow inorganic nanoparticles and solid inorganic nanoparticles may not occur sufficiently during the manufacturing process of the low refractive index layer, resulting in a mixture that increases reflectivity, causes excessive surface irregularities, and reduces antifouling properties.

[0130] Furthermore, if the content of the hollow inorganic nanoparticles and solid inorganic nanoparticles in the low refractive index layer is too low, a large number of the solid inorganic nanoparticles may not be located in the region close to the interface between the hard coat layer and the low refractive index layer, resulting in a very high reflectivity of the low refractive index layer.

[0131] The hollow inorganic nanoparticles and solid inorganic nanoparticles are each included in the composition in colloidal form, dispersed in a predetermined dispersion medium. Each colloidal form, including the hollow inorganic nanoparticles and solid inorganic nanoparticles, may include an organic solvent as the dispersion medium.

[0132] The content of hollow inorganic nanoparticles and solid inorganic nanoparticles in the colloid is determined by considering the range of content of each in the photocurable coating composition and the viscosity of the photocurable coating composition, for example, the solid content of each in the colloid of hollow inorganic nanoparticles and solid inorganic nanoparticles may be 5% to 60% by weight.

[0133] Here, the organic solvent in the dispersion medium includes alcohols such as methanol, isopropyl alcohol, ethylene glycol, and butanol; ketones such as methyl ethyl ketone and methyl isobutyl ketone; aromatic hydrocarbons such as toluene and xylene; amides such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; esters such as ethyl acetate, butyl acetate, and γ-butyrolactone; ethers such as tetrahydrofuran and 1,4-dioxane; or mixtures thereof.

[0134] The aforementioned photopolymerization initiator can be any known compound used in photocurable resin compositions without particular limitations. Specifically, benzophenone compounds, acetophenone compounds, biimidazole compounds, triazine compounds, oxime compounds, or mixtures of two or more of these can be used.

[0135] The photopolymerization initiator can be used in an amount of 1 to 100 parts by weight per 100 parts by weight of the photopolymerizable compound. If the amount of the photopolymerization initiator is too small, the photocurable coating composition may not cure during the photocuring stage, resulting in residual substances. If the amount of the photopolymerization initiator is too large, unreacted initiator may remain as an impurity, or the crosslinking density may decrease, leading to a decrease in the mechanical properties of the produced film or an extremely high reflectivity.

[0136] Furthermore, the photocurable coating composition may further contain an organic solvent.

[0137] Non-limiting examples of the organic solvent include ketones, alcohols, acetates, and ethers, or mixtures of two or more of these.

[0138] Specific examples of such organic solvents include ketones such as methyl ethyl ketone, 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, or polyethylene glycol monomethyl ether acetate; ethers such as tetrahydrofuran or propylene glycol monomethyl ether; or mixtures of two or more of these.

[0139] The organic solvent is included in the photocurable coating composition by adding it when mixing the components of the photocurable coating composition, by dispersing the components in the organic solvent, or by adding it in a mixed state. If the amount of organic solvent in the photocurable coating composition is too low, the flowability of the photocurable coating composition will decrease, which may result in defects such as striped patterns in the final produced film. Conversely, if the organic solvent is added in excess, the solid content will be low, coating and film formation will not be performed sufficiently, the physical properties and surface characteristics of the film will deteriorate, and defects may occur during the drying and curing process. As a result, the photocurable coating composition may contain organic solvent such that the total solid content concentration of the components is 1% to 50% by weight, or 2% to 20% by weight.

[0140] The hard coat layer may have a thickness of 0.1 μm to 100 μm.

[0141] The hard coat layer may further include a substrate bonded to the other surface. The specific type and thickness of the substrate are not particularly limited, and any known substrate used in the manufacture of low refractive index layers or anti-reflective films can be used without any particular restrictions.

[0142] On the other hand, the anti-reflective film of the above embodiment is provided by a method for manufacturing an anti-reflective film, which includes the steps of: applying a resin composition for forming a low refractive index layer, comprising a photocurable compound or its (co)polymer, a fluorine-containing compound containing a photoreactive functional group, a photoinitiator, hollow inorganic nanoparticles, and solid inorganic nanoparticles, onto a hard coat layer and drying it at a temperature of 35°C to 100°C; and photocuring the dried resin composition.

[0143] The low refractive index layer can be formed by applying a resin composition for forming a low refractive index layer, which includes a photocurable compound or its (co)polymer, a fluorine-containing compound containing a photoreactive functional group, a photoinitiator, hollow inorganic nanoparticles, and solid inorganic nanoparticles, onto a hard coat layer and drying at a temperature of 35°C to 100°C or 40°C to 80°C.

[0144] If the drying temperature of the resin composition for forming the low refractive index layer applied on the hard coat layer is less than 35°C, the antifouling properties of the formed low refractive index layer may be significantly reduced. Furthermore, if the drying temperature of the resin composition for forming the low refractive index layer applied on the hard coat layer exceeds 100°C, the phase separation between the hollow inorganic nanoparticles and the solid inorganic nanoparticles does not occur sufficiently during the manufacturing process of the low refractive index layer, resulting in a mixture that not only reduces the scratch resistance and antifouling properties of the low refractive index layer but also significantly increases its reflectivity.

[0145] A low-refractive-index layer having the above-described properties can be formed by adjusting the drying temperature and the density difference between the solid inorganic nanoparticles and the hollow inorganic nanoparticles during the drying process of the resin composition for forming a low-refractive-index layer applied on the hard coat layer. 3 It can have a higher density than described above, and due to this density difference, the solid inorganic nanoparticles can be located closer to the hard coat layer in the low refractive index layer formed on the hard coat layer.

[0146] On the other hand, the step of drying the resin composition for forming the low refractive index layer applied on the hard coat layer at a temperature of 35°C to 100°C can be carried out for 10 seconds to 5 minutes, or 30 seconds to 4 minutes.

[0147] If the drying time is too short, the phase separation phenomenon between the solid inorganic nanoparticles and the hollow inorganic nanoparticles described above may not occur sufficiently. On the other hand, if the drying time is too long, the formed low refractive index layer may erode the hard coat layer.

[0148] On the other hand, the hard coat layer can be any commonly known hard coat layer without any particular limitations.

[0149] An example of the hard coat layer is a binder resin containing a photocurable resin, and a hard coat layer containing organic or inorganic fine particles dispersed in the binder resin.

[0150] The photocurable resin contained in the hard coat layer is a polymer of a photocurable compound that can undergo a polymerization reaction when irradiated with light such as ultraviolet light, and may be a common one in the industry. Specifically, the photocurable resin may include one or more selected from the reactive acrylate oligomer group consisting of urethane acrylate oligomers, epoxy acrylate oligomers, polyester acrylates, and polyether acrylates, and the polyfunctional acrylate monomer group consisting of dipentaerythritol hexaacrylate, dipentaerythritol hydroxypentaacrylate, pentaerythritol tetraacrylate, pentaerythritol triacrylate, trimethylene propyl triacrylate, propoxylated glycerol triacrylate, trimethylpropaneethoxytriacrylate, 1,6-hexanediol diacrylate, propoxylated glycerol triacrylate, tripropylene glycol diacrylate, and ethylene glycol diacrylate.

[0151] The particle size of the organic or inorganic fine particles is not specifically limited, 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. The particle size of the organic or inorganic fine particles is defined by the volume-average diameter.

[0152] Furthermore, while the specific examples of organic or inorganic fine particles contained in the hard coat layer are not limited, for example, the organic or inorganic fine particles may be organic fine particles made of acrylic resin, styrene resin, epoxide resin, and nylon resin, or inorganic fine particles made of silicon dioxide, titanium dioxide, indium oxide, tin oxide, zirconium oxide, and zinc oxide.

[0153] The binder resin of the hard coat layer may further contain a high molecular weight (co)polymer with a weight-average molecular weight of 10,000 or more.

[0154] The high molecular weight (co)polymer may be one or more selected from the group consisting of cellulose polymers, acrylic polymers, styrene polymers, epoxide polymers, nylon polymers, urethane polymers, and polyolefin polymers.

[0155] On the other hand, another example of the hard coat layer is a hard coat layer comprising a photocurable resin binder resin and an antistatic agent dispersed in the binder resin.

[0156] The photocurable resin contained in the hard coat layer is a polymer of a photocurable compound that can undergo a polymerization reaction when irradiated with light such as ultraviolet light, and may be a common type in the industry. Preferably, the photocurable compound is a polyfunctional (meth)acrylate monomer or oligomer, and in this case, it is advantageous in terms of ensuring the physical properties of the hard coat layer if the number of (meth)acrylate functional groups is 2 to 10, preferably 2 to 8, and more preferably 2 to 7. More preferably, the photocurable compound may be one or more selected from the group consisting of pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol hepta(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tolylene diisocyanate, xylene diisocyanate, hexamethylene diisocyanate, trimethylolpropane tri(meth)acrylate, and trimethylolpropane polyethoxytri(meth)acrylate.

[0157] The antistatic agent may be a quaternary ammonium salt compound; a pyridinium salt; a cationic compound having 1 to 3 amino groups; anionic compounds such as sulfonic acid bases, sulfate ester bases, phosphate ester bases, or phosphonic acid bases; amphoteric compounds such as amino acid-based or aminosulfate ester-based compounds; nonionic compounds such as imino alcohol-based compounds, glycerin-based compounds, or polyethylene glycol-based compounds; organometallic compounds such as metal alkoxide compounds containing tin or titanium; metal chelate compounds such as acetylacetonate salts of the organometallic compounds; two or more reaction products or polymers of these compounds; or 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 bases in its molecule, and low-molecular-weight or high-molecular-weight types can be used without limitation.

[0158] Furthermore, conductive polymers and metal oxide nanoparticles can also be used as the antistatic agent. Examples of conductive polymers include aromatic conjugated poly(paraphenylene), heterocyclic conjugated polypyrrole and polythiophene, aliphatic conjugated polyacetylene, conjugated polyaniline containing heteroatoms, mixed conjugated poly(phenylenevinylene), double-chain conjugated compounds having multiple conjugated chains in the molecule, and conductive composites obtained by grafting or block copolymerizing conjugated polymer chains onto saturated polymers. Examples of metal oxide nanoparticles include zinc oxide, antimony oxide, tin oxide, cerium oxide, indium tin oxide, indium oxide, aluminum oxide, antimony-doped tin oxide, and aluminum-doped zinc oxide.

[0159] The hard coat layer, which includes the binder resin of the photocurable resin and an antistatic agent dispersed in the binder resin, may further contain one or more compounds selected from the group consisting of alkoxysilane oligomers and metal alkoxide oligomers.

[0160] The alkoxysilane compound may be one of those commonly used in the industry, but preferably it may be one or more compounds selected from the group consisting of tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methacryloxypropyltrimethoxysilane, glycidoxypropyltrimethoxysilane, and glycidoxypropyltriethoxysilane.

[0161] Furthermore, the metal alkoxide oligomer can be produced by a sol-gel reaction of a composition containing a metal alkoxide compound and water. The sol-gel reaction can be carried out by a method similar to the method for producing the alkoxysilane oligomer described above.

[0162] However, since the metal alkoxide compound can react rapidly with water, the sol-gel reaction can be carried out by diluting the metal alkoxide compound in an organic solvent and then slowly dropping water over it. In this case, considering the reaction efficiency, 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.

[0163] Here, the metal alkoxide compound may be one or more compounds selected from the group consisting of titanium tetraisopropoxide, zirconium isopropoxide, and aluminum isopropoxide.

[0164] According to another embodiment of the present invention, a polarizing plate including the anti-reflective film is provided.

[0165] The polarizing plate may include a polarizer and an anti-reflective film formed on at least one surface of the polarizer.

[0166] The material and manufacturing method of the polarizer are not particularly limited, and ordinary materials and manufacturing methods known in the art can be used. For example, the polarizer may be a polyvinyl alcohol-based polarizer.

[0167] The polarizer and the anti-reflective film are bonded together with an adhesive such as a water-based adhesive or a non-water-based adhesive.

[0168] According to yet another embodiment of the present invention, a display device including the anti-reflective film described above is provided.

[0169] The specific examples of the display device are not limited to those mentioned above, and may include, for example, a liquid crystal display, a plasma display, an organic light-emitting diode (OLED) display, and a flexible display.

[0170] In the aforementioned display device, the anti-reflective film is provided on the outermost surface of the display panel, either on the observer side or the backlight side.

[0171] In the display device including the anti-reflective film, the anti-reflective film is placed on one surface of the polarizing plate that is relatively farther from the backlight unit among a pair of polarizing plates.

[0172] Furthermore, the display device may include a display panel, a polarizer provided on at least one surface of the panel, and an anti-reflective film provided on the opposite side of the polarizer that is in contact with the panel.

[0173] According to yet another embodiment of the present invention, an organic light-emitting diode display apparatus including the anti-reflective film is provided.

[0174] While organic light-emitting diode (OLED) displays typically have high resolution and high color reproduction capabilities, anti-reflective films with high color values, such as those with an absolute value of b* greater than 4 in the CIE Lab color space, can reduce the color reproduction capabilities of OLED displays.

[0175] In contrast, the anti-reflective film of the above embodiment achieves high light transmittance and low reflectance, while having a low color value with an absolute value of 4 or less for b* in the CIE Lab color space, thus possessing the characteristic of being colorless and transparent. This makes it possible to maintain or enhance the color reproduction capabilities of the organic light-emitting diode display device. [Effects of the Invention]

[0176] According to the present invention, it is possible to provide an anti-reflective film that has high light transmittance, high scratch resistance and stain resistance simultaneously, and is colorless and transparent while achieving low reflectivity, as well as a polarizing plate, a display device, and an organic light-emitting diode display device containing the same. [Brief explanation of the drawing]

[0177] [Figure 1] This figure shows the reflectance pattern of the anti-reflective film of Example 1. [Figure 2] This figure shows the reflectance pattern of the anti-reflective film of Example 2. [Figure 3] This figure shows the reflectance pattern of the anti-reflective film of Example 3. [Figure 4] This figure shows the reflectance pattern of the anti-reflective film of Example 4. [Figure 5] This figure shows the reflectance pattern of the anti-reflective film of Example 5. [Figure 6] This figure shows the reflectance pattern of the anti-reflective film of Example 6. [Figure 7] This figure shows the reflectance pattern of the anti-reflective film of Comparative Example 1. [Figure 8] This figure shows the reflectance pattern of the anti-reflective film of Comparative Example 2. [Figure 9] This figure shows the reflectance pattern of the anti-reflective film of Comparative Example 3. [Figure 10] This figure shows the reflectance pattern of the anti-reflective film of Comparative Example 4. [Modes for carrying out the invention]

[0178] The invention will be described in more detail by the following embodiments. However, the following embodiments are merely illustrative of the present invention, and the content of the present invention is not limited to the following embodiments.

[0179] <Manufacturing Examples 1 and 2: Manufacturing of Hard Coat Layers>

[0180] Manufacturing Example 1: Manufacturing of Hard Coat Layer (HD1) A hard coating composition was prepared by diluting 75g of trimethylolpropane triacrylate (TMPTA), 2g of silica microparticles with an average particle size of 20nm (surface treated: 3-methacryloyloxypropylmethyldimethoxysilane), 0.05g of fluorine-based acrylate (RS-537, DIC Corporation), and 1.13g of photoinitiator (Irgacure 184, Ciba Corporation) in MEK (methyl ethyl ketone) solvent to a solid content concentration of 40% by weight.

[0181] The diluted hard coating solution was coated onto a triacetylcellulose film with a #10 Mayer bar, and after drying and photocuring under the conditions shown in Table 1 below, a hard coating film with a thickness of 5 μm was produced. The air velocity applied during drying of the hard coat layer in each of the following examples and comparative examples is shown in Table 2.

[0182] Manufacturing Example 2: Manufacturing of Hard Coat Layer (HD2) A hard coating composition was prepared by diluting the solids of 75g of trimethylolpropane triacrylate (TMPTA), 2g of silica microparticles with an average particle size of 20nm (surface treated: 3-methacryloyloxypropylmethyldimethoxysilane), 0.5g of fluorine-based acrylate (RS-537, DIC Corporation), and 1.13g of photoinitiator (Irgacure 184, Ciba Corporation) in MEK (methyl ethyl ketone) solvent to a solids concentration of 40% by weight.

[0183] The diluted hard coating solution was coated onto a triacetylcellulose film with a #10 Mayer bar, and after drying and photocuring under the conditions shown in Table 1 below, a hard coating film with a thickness of 5 μm was produced. The air velocity applied during drying of the hard coat layer in each of the following examples and comparative examples is shown in Table 2.

[0184] [Table 1]

[0185] <Manufacturing Examples 3-6: Manufacturing of Low-Refractive Index Layer Coating Compositions>

[0186] Manufacturing Example 3. Production of a photocurable coating composition for manufacturing a low refractive index layer. 100 parts by weight of trimethylolpropane triacrylate (TMPTA) is mixed with hollow silica nanoparticles (diameter: approximately 50-60 nm, density: 1.96 g / cm³). 3 , manufactured by JSC Catalyst and Chemicals) 281 parts by weight, solid silica nanoparticles (diameter: approx. 12 nm, density: 2.65 g / cm) 3 63 parts by weight of (Nissan Chemical Corporation), 131 parts by weight of the first fluorine-containing compound (X-71-1203M, Shin-Etsu Chemical Co., Ltd.), 19 parts by weight of the second fluorine-containing compound (RS-537, DIC Corporation), and 31 parts by weight of the initiator (Irgacure 127, Ciba Corporation) were diluted in a solvent prepared by mixing methyl isobutyl ketone (MIBK): diacetone alcohol (DAA): isopropyl alcohol in a weight ratio of 3:3:4 to a solid content concentration of 3% by weight.

[0187] Manufacturing Example 4. Production of a photocurable coating composition for manufacturing a low refractive index layer. 100 parts by weight of trimethylolpropane triacrylate (TMPTA) is mixed with hollow silica nanoparticles (diameter: approximately 50-60 nm, density: 1.96 g / cm³). 3, manufactured by JSC Catalyst and Chemicals) 200 parts by weight, solid silica nanoparticles (diameter: approx. 12 nm, density: 2.65 g / cm) 3 48 parts by weight of (Nissan Chemical Corporation), 111 parts by weight of the first fluorine-containing compound (X-71-1203M, Shin-Etsu Chemical Co., Ltd.), 15 parts by weight of the second fluorine-containing compound (RS-537, DIC Corporation), and 21 parts by weight of the initiator (Irgacure 127, Ciba Corporation) were diluted in a solvent prepared by mixing methyl isobutyl ketone (MIBK): diacetone alcohol (DAA): isopropyl alcohol in a weight ratio of 3:3:4 to a solid content concentration of 3% by weight.

[0188] Manufacturing Example 5. Production of a photocurable coating composition for manufacturing a low refractive index layer. 100 parts by weight of trimethylolpropane triacrylate (TMPTA) is mixed with hollow silica nanoparticles (diameter: approximately 60-70 nm, density: 1.79 g / cm³). 3 , manufactured by JSC Catalyst and Chemicals) 300 parts by weight, solid silica nanoparticles (diameter: approx. 12 nm, density: 2.65 g / cm) 3 85 parts by weight of (Nissan Chemical Corporation), 150 parts by weight of the first fluorine-containing compound (X-71-1203M, Shin-Etsu Chemical Co., Ltd.), 33 parts by weight of the second fluorine-containing compound (RS-537, DIC Corporation), and 35 parts by weight of the initiator (Irgacure 127, Ciba Corporation) were diluted in a solvent prepared by mixing methyl isobutyl ketone (MIBK): diacetone alcohol (DAA): isopropyl alcohol in a weight ratio of 3:3:4 to a solid content concentration of 3% by weight.

[0189] Manufacturing Example 6. Production of a photocurable coating composition for manufacturing a low refractive index layer. 100 parts by weight of trimethylolpropane triacrylate (TMPTA) is mixed with hollow silica nanoparticles (diameter: approximately 50-60 nm, density: 1.96 g / cm³). 3 , manufactured by JSC Catalyst and Chemicals) 248 parts by weight, solid silica nanoparticles (diameter: approx. 12 nm, density: 2.65 g / cm) 368 parts by weight of (Nissan Chemical Corporation), 120 parts by weight of a first fluorine-containing compound (X-71-1203M, Shin-Etsu Chemical Co., Ltd.), 33 parts by weight of a second fluorine-containing compound (RS-537, DIC Corporation), and 30 parts by weight of an initiator (Irgacure 127, Ciba Corporation) were diluted in a solvent prepared by mixing methyl isobutyl ketone (MIBK): diacetone alcohol (DAA): isopropyl alcohol in a weight ratio of 3:3:4 to a solid content concentration of 3% by weight.

[0190] Examples and comparative examples; manufacturing of low refractive index layers and anti-reflective films The hard coat layers of Production Example 1 and Production Example 2 were coated with the photocurable coating compositions obtained above using a #4 Mayer bar to a thickness of approximately 120 nm, and then dried and cured under the conditions shown in Table 2 below. The curing was carried out under nitrogen purging, at a drying temperature of 90°C for 1 minute.

[0191] [Table 2]

[0192] <Experimental Example: Measurement of Physical Properties of Anti-Reflective Film> The following experiments were conducted on the anti-reflective films obtained in the above examples and comparative examples.

[0193] 1. Measurement of the surface energy of hard coating films The surface energy of the hard coat layers in both the examples and comparative examples was determined by measuring the contact angles of di-water (Gebhardt) and di-iodomethane (Owens) at 10 points using a Kruss DSA-100 contact angle analyzer, calculating the average value, and then converting the average contact angle to surface energy. In the measurement of the surface energy, Dropshape Analysis software was used, and the following general formula 2 of the OWRK (Owen, Wendt, Rable, Kaelble) method was applied to the program to convert the contact angle to surface energy.

number

[0194] 2. Measurement of reflectance and b* in the CIE Lab color space of anti-reflective film The reflectance and b* values ​​of the anti-reflective films obtained in the examples and comparative examples were measured at each wavelength in the visible light region (380-780 nm) using a Solidspec3700 (Shimadzu Corporation) instrument.

[0195] The test specimen was scanned from 380 nm to 780 nm to measure the reflectance at each wavelength, and then the average reflectance and b* were derived using the UV-2401PC Color Analysis program.

[0196] 3. Measurement of stain resistance The anti-reflective properties of the anti-reflective films obtained in the examples and comparative examples were measured by drawing a 5 cm long straight line on the surface with a black name pen and checking how many times it took for the line to be wiped off with a lint-free wipe. <Measurement Standards> O: The number of times it is deleted is 10 or less. △: Number of times until it is deleted is between 11 and 20 X: More than 20 times before being deleted

[0197] 4. Measurement of scratch resistance A load was applied to steel wool (#0000) and the surface of the anti-reflective films obtained in the examples and comparative examples was rubbed by moving it back and forth 10 times at a speed of 27 rpm. The maximum load was measured when the number of scratches less than 1 cm in size that could be observed with the naked eye was one or less.

[0198] 5. Measurement using the polarization analysis method (ellipsometry) The ellipticity of the polarization was measured for the low refractive index layers obtained in each of the above examples and comparative examples using polarization analysis (ellipsometry).

[0199] Specifically, the linear polarization was measured in the wavelength range of 380 nm to 1000 nm using a JAWoollam M-2000 instrument with an incident angle of 70° on the low refractive index layers obtained in each of the above examples and comparative examples.

[0200] The measured linear polarization measurement data (Ellipsometry data (Ψ, Δ)) was optimized (fitted) to the first and second layers (Layer 1, Layer 2) of the low refractive index layer using the Cauchy model of the following general formula 1, with the Complete EASE software.

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[0201] Furthermore, for the mixed layer of the low refractive index layer, the refractive index and thickness were optimized (fitted) using the Diffuse Layer Model mode. The MSE of both the Cauchy model and the Diffuse Layer Model was set to 5 or less.

[0202] 6. Measurement of refractive index For the particle-containing layer contained in the low refractive index layer obtained in the above example, the refractive index at wavelengths of 550 nm and 400 nm was calculated using elliptic polarization measured at wavelengths of 380 nm to 1,000 nm, the Cauchy model, and the Diffuse Layer Model.

[0203] [Table 3] [Table 4]

[0204] As shown in Table 3 above, in the example in which a particle mixture layer containing hollow inorganic nanoparticles and solid inorganic nanoparticles, having a thickness of 1.5 nm to 22 nm, is present in the low refractive index layer, the anti-reflective film achieved a reflectance of 1.5% or less at a wavelength of 550 nm, while the ratio of the reflectance at 400 nm to the reflectance at 550 nm was confirmed to be 1.3 to 2.7.

[0205] Furthermore, the results in Table 3 confirm that the anti-reflective film in the example includes a mixed layer in the low refractive index layer, and undergoes phase separation such that regions mainly containing hollow inorganic nanoparticles and solid inorganic nanoparticles are separated, thereby achieving high scratch resistance and excellent anti-fouling properties. Moreover, since it has a low color value with an absolute value of 4 or less for b* in the CIE Lab color space, it can have the property of being colorless and transparent.

[0206] In contrast, as shown in Table 4, in the comparative example, the anti-reflective film was considered to be divided into regions where hollow inorganic nanoparticles and solid inorganic nanoparticles were mainly distributed, and was not considered to be unevenly distributed (phase-separated). As a result, it was confirmed that the scratch resistance and anti-fouling properties were insufficient.

[0207] Furthermore, the results in Table 4 indicate that the low refractive index layer of the anti-reflective film in the comparative example contains a particle-containing layer with a thickness exceeding 22 nm, or that the particle-containing layer is located too close to or too far from the hard coat layer. Consequently, the ratio of the reflectance at 400 nm to the reflectance at 550 nm in such the comparative example of the anti-reflective film exceeds 2.7, resulting in a greenish tint. This confirms that the film has an opacity or coloration that makes it unsuitable for application to polarizing plates or display devices.

Claims

1. It includes a hard coat layer and a low refractive index layer, The low refractive index layer is formed on one surface of the hard coat layer and includes a layer on the interface side between the hard coat layer and the low refractive index layer in which solid silica nanoparticles are unevenly distributed, a particle mixture layer containing hollow inorganic nanoparticles and solid silica nanoparticles, and a layer on the opposite side of the interface in which hollow inorganic nanoparticles are unevenly distributed. The particle-mixed layer has a thickness of 2.5 nm to 18.1 nm and is located at a distance of 15 nm to 60 nm from one surface of the hard coat layer. An anti-reflective film in which the ratio of reflectance at a wavelength of 400 nm to reflectance at a wavelength of 550 nm is 1.5 to 2.

5.

2. The anti-reflective film according to claim 1, wherein the reflectance at a wavelength of 550 nm is greater than 0.5% and less than or equal to 1.5%.

3. The anti-reflective film according to claim 1 or 2, wherein the reflectance at a wavelength of 400 nm is 1.0% to 3.50%.

4. The anti-reflective film according to claim 1, wherein the thickness of the particle-mixed layer is determined by optimizing (fitting) the ellipticity of the polarization measured by polarization analysis (ellipsometry) using a diffuse layer model.

5. The anti-reflective film according to any one of claims 1 to 4, wherein the low refractive index layer has a thickness of 20 nm to 240 nm.

6. The anti-reflective film according to any one of claims 1 to 5, wherein the surface energy of the hard coat layer is greater than 34 mN / m.

7. The low refractive index layer comprises hollow inorganic nanoparticles and solid silica nanoparticles dispersed in a binder resin. The anti-reflective film according to any one of claims 1 to 6, wherein in the low refractive index layer, 50 volume percent or more of the solid silica nanoparticles are present between one surface of the hard coat layer and the particle mixture layer.

8. The anti-reflective film according to any one of claims 1 to 7, wherein the region between one surface of the hard coat layer and the particle mixture layer has a refractive index of 1.46 to 1.65 at a wavelength of 550 nm.

9. The anti-reflective film according to claim 7, wherein in the low refractive index layer, 50 volume percent or more of the total hollow inorganic nanoparticles are present in the region from the particle mixture layer to one surface of the low refractive index layer facing the hard coat layer.

10. The anti-reflective film according to claim 9, wherein the region from the particle-mixed layer to one surface of the low-refractive-index layer facing the hard coat layer has a refractive index of 1.0 to 1.40 at a wavelength of 550 nm.

11. The solid silica nanoparticles have a diameter of 0.5 to 100 nm. The anti-reflective film according to any one of claims 1 to 10, wherein the hollow inorganic nanoparticles have a diameter of 1 to 200 nm.

12. The density difference between the solid silica nanoparticles and the hollow inorganic nanoparticles is 0.50 g / cm³. ３ ~3.00 g / cm ３ The anti-reflective film according to any one of claims 1 to 11.

13. The low refractive index layer comprises a binder resin, and hollow inorganic nanoparticles and solid silica nanoparticles dispersed in the binder resin. The anti-reflective film according to any one of claims 1 to 12, wherein the binder resin contained in the low refractive index layer comprises a crosslinked (co)polymer between a photopolymerizable compound and a fluorine-containing compound containing a photoreactive functional group.

14. The anti-reflective film according to any one of claims 1 to 13, wherein the hard coat layer comprises a binder resin containing a photocurable resin and organic or inorganic fine particles dispersed in the binder resin.

15. A polarizing plate comprising an anti-reflective film and a polarizer according to any one of claims 1 to 14.

16. A display device comprising an anti-reflective film according to any one of claims 1 to 14.

17. An organic light-emitting diode display apparatus comprising an anti-reflective film according to any one of claims 1 to 14.

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