Optical display device

Abstract

Provided is an optical display device comprising: a panel for an optical display device; and a polarizing plate laminated on one surface of the panel for an optical display device, wherein the polarizing plate comprises a polarizer, a protective layer laminated on one surface of the polarizer, and a first retardation layer laminated on the other surface of the polarizer, the polarizer has a color value ac of -2.0 to 3.3 and a color value bc of -5.5 to 1.5, the protective layer comprises a base layer, an anti-glare layer, and an anti-reflection layer, which are sequentially laminated from the polarizer, the anti-glare layer comprises a light-diffusing agent having an average particle diameter D50 of 1.8 to 2.5 um, and the protective layer has a total haze of 20 to 50%.

Description

optical display device

[0001] It is about optical display devices.

[0002] Organic light-emitting diode displays can suffer from reduced visibility and contrast due to reflection of external light. To address this, polarizing plates are used. Polarizing plates can reduce the reflectivity of reflected external light, thereby providing an anti-reflection function. Polarizing plates are fundamentally required to significantly improve screen quality by improving the black level from the front.

[0003] A polarizing plate may include a polarizer and a phase difference layer. However, there are limitations to how well a polarizing plate can reduce the dispersion of reflected color from the front and sides.

[0004] The background technology of the present invention is disclosed in Korean Patent Publication No. 10-2013-0103595, etc.

[0005] According to one embodiment, an optical display device having a low reflection color dispersion value between the front and side is provided.

[0006] According to another embodiment, an optical display device having no screen flicker and high panel side reflectivity is provided.

[0007] According to one embodiment, an optical display device is provided.

[0008] The optical display device includes a panel for an optical display device, and a polarizing plate laminated on one surface of the panel for an optical display device, the polarizing plate includes a polarizer, a protective layer laminated on one surface of the polarizer, and a first phase difference layer laminated on the other surface of the polarizer, the polarizer having a color value ac of -2.0 to 3.3 and a color value bc of -5.5 to 1.5, the protective layer including a base layer, an antiglare layer, and an antireflection layer sequentially laminated from the polarizer, the antiglare layer including a light diffusing agent having an average particle diameter D50 of 1.8 to 2.5 ㎛, and the protective layer has a total haze of 20 to 50%.

[0009] According to one implementation example, the reflection color dispersion value between the front and side may be low, resulting in low screen unevenness and excellent screen quality.

[0010] Figure 1 is a cross-sectional view of an optical display device of one embodiment.

[0011] Figure 2 is a cross-sectional view of an optical display device of another embodiment.

[0012] Figures 3, 4, 5, and 6 are the results of evaluating the reflection color values ​​of Example 1, Example 4, Comparative Example 5, and Comparative Example 6, respectively.

[0013] The present invention is described in detail, with reference to the attached drawings, by way of examples, so that those skilled in the art can easily practice the invention. The present invention may be implemented in various different forms and is not limited to the examples described herein.

[0014] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise.

[0015] In order to clearly explain the present invention in the drawings, parts irrelevant to the description have been omitted, and the same or similar components have been designated by the same designation throughout the specification. The length and size of each component in the drawings are for the purpose of explaining the present invention, and the present invention is not limited to the length and size of each component described in the drawings.

[0016] In this specification, “upper” and “lower” are defined based on the drawing, and “upper” may be changed to “lower” and “lower” may be changed to “upper” depending on the viewing angle.

[0017] In this specification, the “in-plane phase difference (Re)” is represented by the following formula A:

[0018] [Formula A]

[0019] Re = (nx - ny) xd

[0020] (In the above formula A, nx and ny are the refractive indices of the slow axis direction and the fast axis direction of the phase difference layer, respectively, at the measurement wavelength, and d is the thickness of the phase difference layer (unit: nm).)

[0021] Unless otherwise specified herein, nx, ny, and nz represent the refractive indices in the long axis direction, the true axis direction, and the thickness direction at a wavelength of 550 nm.

[0022] In this specification, the axis with the highest refractive index in the in-plane direction is defined as the "ground axis," and the axis with the lowest refractive index in the in-plane direction is defined as the "true axis." The "ground axis" and the "true axis" may be substantially orthogonal, but the present invention is not limited thereto.

[0023] In this specification, 'reverse wavelength dispersion' means satisfying the relationship Re(450) < Re(550) < Re(650), where Re(450), Re(55), and Re(650) are in-plane phase differences at wavelengths of 450, 550, and 650 nm, respectively.

[0024] According to one embodiment, the optical display device has a low reflection color dispersion value between the front and side surfaces. The higher the reflection color dispersion value between the front and side surfaces, the more likely it is that color differences will occur between the front and side surfaces when external light is transmitted and reflected within the optical display device, which may lead to more severe screen unevenness.

[0025] In one specific example, the optical display device may have a reflection color dispersion value Eab* between the front and side surfaces of 5 or less. The Eab* value may be calculated using the following formula:

[0026] [formula]

[0027] Eab* = ((a - b) 2 + (c - d) 2 )) 1 / 2

[0028] (In the above formula,

[0029] a is the reflected color value a* measured at a 60° angle

[0030] b is the reflected color value a* measured at 0° in front

[0031] c is the reflected color value b* measured at a 60° angle

[0032] d is the reflected color value b* measured at 0° in front

[0033] The optical display device includes a panel for an optical display device, and a polarizing plate laminated on one surface of the panel for an optical display device, the polarizing plate includes a polarizer, a protective layer laminated on one surface of the polarizer, and a first phase difference layer laminated on the other surface of the polarizer, the polarizer having a color value ac of -2.0 to 3.3 and a color value bc of -5.5 to 1.5, the protective layer including a base layer, an antiglare layer, and an antireflection layer sequentially laminated from the polarizer, the antiglare layer including a light diffusing agent having an average particle diameter D50 of 1.8 to 2.5 ㎛, and the protective layer has a total haze of 20 to 50%.

[0034] The above optical display device can lower the Eab* value described above by adjusting the color value ac value and the color value bc value of the polarizer, and by adjusting the overall haze of the protective layer and the average particle diameter D50 of the light diffusing agent in the antiglare layer within the protective layer.

[0035] polarizing plate

[0036] polarizer

[0037] The above polarizer has a color value ac value of -2.0 to 3.3 and a color value bc value of -5.5 to 1.5.

[0038] First, a method for measuring the color values ​​ac and bc of a polarizer is described. In this regard, the color values ​​ac and bc of a polarizer were measured using V7100 (JASCO) at a wavelength of 380 nm to 780 nm, and a reference polarizer is installed in the V7100, so that the color values ​​ac and bc of a polarizer can be measured when the absorption axes of the polarizers of the sample polarizer and the reference polarizer are at 90° to each other.

[0039] When a polarizer having the above color values ​​ac and bc is applied to a panel for an optical display device with a polarizing plate having a protective layer described below, it can be easily used to ensure that the above-described Eab* value is 5 or less and to prevent screen flickering.

[0040] Polarizers with a color value ac less than -2.0 may exhibit blurry color in front and side reflections. Polarizers with a color value ac greater than 3.3 may exhibit reddish color in front and side reflections. For example, polarizers with a color value ac value of -1.6 to 3.1 may exhibit blurry color in front and side reflections.

[0041] Polarizers with a color value bc value less than -5.5 may have blurry color issues in front and side reflections. Polarizers with a color value bc value greater than 1.5 may have reddish color issues in front and side reflections. For example, a polarizer's color value bc value may be between -5.1 and 1.2.

[0042] The polarizer may have a thickness of 1 to 40 μm, specifically 15 to 30 μm, and more specifically 16 to 20 μm. In the above range, it may be used in a polarizing plate.

[0043] The polarizer may include a polarizer that contains a dichroic dye and is uniaxially stretched. Specifically, the polarizer containing a dichroic dye may include a polarizer manufactured by uniaxially stretching a base film for a polarizer in the machine direction (MD) and dyeing the base film with a dichroic dye (e.g., iodine or an iodine-containing material such as potassium iodide). The base film for a polarizer may include, but is not limited to, a polyvinyl alcohol-based film or a derivative thereof.

[0044] The above polyvinyl alcohol-based film contains hydrophilic functional groups and hydrophobic functional groups. The hydrophobic functional groups exist in addition to the hydroxyl group (OH group), which is a hydrophilic functional group present in the polyvinyl alcohol-based film. By manufacturing a polyvinyl alcohol-based film containing both the hydrophilic functional groups and the hydrophobic functional groups by the process described below, the polarizer can easily reach the color values ​​ac and bc described above.

[0045] The hydrophobic functional group is present in at least one of the main chain and side chain of the polyvinyl alcohol-based resin constituting the polyvinyl alcohol-based film. The "main chain" refers to a portion forming the main skeleton of the polyvinyl alcohol-based resin, and the "side chain" refers to a skeleton connected to the main chain. Preferably, the hydrophobic functional group may be present in the main chain of the polyvinyl alcohol-based resin.

[0046] Polyvinyl alcohol-based resins having hydrophilic and hydrophobic functional groups introduced therein can be produced by polymerizing one or more vinyl ester monomers such as vinyl acetate, vinyl formate, vinyl propionate, vinyl butyrate, vinyl pivalate, and isopropenyl acetonitrile, and a monomer providing a hydrophobic functional group. Preferably, the vinyl ester monomer may include vinyl acetate. The monomer providing the hydrophobic functional group may include a monomer providing a hydrocarbon repeating unit including ethylene, propylene, or the like.

[0047] The polyvinyl alcohol film may have a thickness of 50 μm or less, for example, 10 to 50 μm. Within this range, the film may not melt or break during stretching.

[0048] The color values ​​ac and bc of the polarizer can be implemented by adjusting the concentration of potassium iodide, etc. during the complementary color process during the polarizer manufacturing process and by adjusting the polymerization degree of the polyvinyl alcohol-based film.

[0049] The polyvinyl alcohol-based film may have a polymerization degree of 2000 to 4000, for example, 2800 to 3200. In the above range, the color values ​​ac and bc of the polarizer can be easily achieved.

[0050] Here, the 'degree of polymerization' means the average degree of polymerization measured according to the description of JIS K 6726-1994, and can be obtained from the intrinsic viscosity [η] (unit: deciliter / g) measured in water at 30°C after re-saponifying and purifying a polyvinyl alcohol-based film by the following equation.

[0051] [ceremony]

[0052] Degree of polymerization = ([η]×10 3 / 8.29) (1 / 0.62)

[0053] There is a method of using GPC equipment, and after separating polyvinyl alcohol film (0.015 g), pretreatment work (stirring 10 ml of NANO3 aqueous solution at 85℃ for 1.5 hours, filtering using a 0.45㎛ water-soluble filter, and then measuring the molecular weight (Mw) using GPC equipment, the degree of polymerization can be obtained through Mw / 44 (chemical structure).

[0054] A polarizer can be manufactured by processing the polyvinyl alcohol-based film described above through the dyeing process, stretching process, crosslinking process, complementary color process, and drying process described below. The order of the dyeing process, stretching process, and crosslinking process may vary depending on the type of polyvinyl alcohol-based film and the polarizer manufacturing process used in manufacturing the polarizer.

[0055] The dyeing process involves treating a polyvinyl alcohol-based film in a dyeing bath containing a dichroic substance. In the dyeing process, the polyvinyl alcohol-based film is immersed in the dyeing bath containing the dichroic substance. The dyeing bath containing the dichroic substance contains an aqueous solution containing the dichroic substance and boric acid. The dyeing bath contains both the dichroic substance and a boron compound, thereby dyeing the polyvinyl alcohol-based film and allowing the polyvinyl alcohol-based film to be stretched without breaking under the stretching conditions described below.

[0056] The dichroic substance may include at least one of iodine, potassium iodide, hydrogen iodide, lithium iodide, sodium iodide, zinc iodide, lithium iodide, aluminum iodide, lead iodide, and copper iodide. The dichroic substance may be included in the dyeing bath, preferably in the dyeing solution, at 0.5 to 10 mol / ml, preferably 0.5 to 5 mol / ml. Within the above range, uniform dyeing may be achieved.

[0057] Boron compounds can help prevent melting and fracture of polyvinyl alcohol-based films during stretching. Boron compounds can help prevent melting and fracture of polyvinyl alcohol-based films even when stretched at high temperatures and high stretch ratios during a stretching process performed after a dyeing process.

[0058] The boron compound may include at least one of boric acid and borax. The boron compound may be included in the dyeing bath, preferably in an amount of 0.1 to 5 wt%, and preferably 0.3 to 3 wt%, of the dyeing solution. Within this range, there may be an effect of achieving high reliability without melting or fracture during the stretching process.

[0059] The temperature of the dyeing solution may preferably be 20°C to 50°C, specifically 25°C to 40°C. The dyeing process may be performed by immersing the polyvinyl alcohol-based film in a dyeing tank for 30 to 120 seconds, specifically 40 to 80 seconds.

[0060] The stretching process includes stretching the dyed polyvinyl alcohol-based film at a stretching ratio of 5.7 times or more, for example, 5.7 to 7 times, at a stretching temperature of 57°C or more, for example, 57°C to 65°C.

[0061] The stretching process is performed by either wet stretching or dry stretching. Preferably, the stretching process includes wet stretching to apply a boron compound in the stretching process. Wet stretching involves uniaxially stretching a polyvinyl alcohol-based film in the mechanical direction in an aqueous solution containing a boron compound.

[0062] The boron compound may include at least one of boric acid and borax, preferably boric acid. The boron compound may be included in the drawing bath, preferably in an amount of 0.5 to 10 wt%, preferably 1 to 5 wt%, of the drawing solution. Within this range, there may be an effect of achieving high reliability without melting or fracture during the drawing process.

[0063] The crosslinking process is performed to enhance the adsorption of dichroic substances in polyvinyl alcohol-based films that have undergone a stretching process. The crosslinking solution used in the crosslinking process contains a boron compound. The boron compound enhances the adsorption of the aforementioned dichroic substances and can help improve the reliability of the polarizer even when exposed to thermal shock.

[0064] The boron compound may include at least one of boric acid and borax. The boron compound may be included in the crosslinking bath, preferably in an amount of 0.5 to 10 wt%, preferably 1 to 5 wt%, in the crosslinking aqueous solution. Within this range, there may be an effect of achieving high reliability without melting or breakage during the stretching process. The temperature of the crosslinking bath solution may be preferably 20°C to 50°C, specifically 25°C to 40°C. The crosslinking process may be performed by immersing the polyvinyl alcohol-based film in the crosslinking bath for 30 to 120 seconds, specifically 40 to 80 seconds.

[0065] The complementary color process can be performed by leaving the polyvinyl alcohol-based film in a complementary color solution containing 3.0 to 7.0 wt%, preferably 3.5 to 6.5 wt%, of potassium iodide. Within this range, the color values ​​ac and bc of the polarizer can be easily achieved.

[0066] The above complementary solution may preferably be at a temperature of 20°C to 50°C, specifically 25°C to 40°C. The complementary treatment may be performed by immersing the polyvinyl alcohol-based film in the complementary solution for 5 to 50 seconds, specifically 5 to 20 seconds.

[0067] The drying process can be performed by treating the polyvinyl alcohol-based film after the complementary color process at 30°C to 80°C, preferably 40°C to 80°C, for 2 minutes or less, preferably 1 to 2 minutes. The drying process can be performed by hot air drying, but is not limited thereto.

[0068] Before the dyeing process, the polyvinyl alcohol-based film may additionally include one or more of a washing process and a swelling process.

[0069] The washing process is to wash the polyvinyl alcohol film with water to remove foreign substances on the polyvinyl alcohol film.

[0070] The swelling process can facilitate the dyeing and stretching of a dichroic material by immersing a polyvinyl alcohol-based film in a swelling bath within a predetermined temperature range. The swelling process may include processing at a temperature of 15°C to 35°C, preferably 20°C to 30°C, for 30 to 50 seconds.

[0071] The polarization degree of the polarizer may be 95% or more, specifically 95% to 100%, and more specifically 98% to 100%. Within the above range, it may be easy to achieve the effects of the present invention.

[0072] The orthogonal transmittance (Tc) of the polarizer may be 0.6% or less, for example, 0.3 to 0.55%, or 0.35 to 0.55%. Within this range, the effect of the above-described polarizing plate may be easily realized.

[0073] protective layer

[0074] The above protective layer is positioned on the light incident surface where external light is incident on the polarizer.

[0075] The above protective layer includes a substrate layer, an anti-glare layer, and an anti-reflection layer sequentially laminated from the polarizer.

[0076] The above protective layer has an overall haze of 20 to 50%. The protective layer having the above haze range can easily have the Eab* value of 5 or less when combined with a polarizer having the above color values ​​ac and bc.

[0077] First, we explain how to measure the overall haze of the protective layer.

[0078] The "internal haze" of the protective layer is a value evaluated in the same way as the overall haze of the protective layer after spraying alcohol (e.g., ethanol) on an alkali-free glass plate with an overall haze of less than 1%, laminating the anti-reflection layer side of the protective layer, and smoothing out the unevenness of the anti-reflection layer surface. The "overall haze" of the protective layer is a value obtained by measuring the protective layer with a conventional haze meter. The "external haze" of the protective layer can be the difference between the overall haze of the protective layer and the internal haze.

[0079] In this specification, “haze” can be measured in the visible light range, for example, at a wavelength of 380 nm to 780 nm.

[0080] Protective layers with an overall haze of less than 20% may have a weak matte effect, resulting in panel reflections falling short. Protective layers with an overall haze of more than 50% may have a strong matte effect, resulting in increased side reflectivity as the viewing angle increases, potentially causing black to appear lifted. For example, a protective layer may have an overall haze of 20 to 30%.

[0081] The overall haze of the protective layer can be achieved by controlling the average particle diameter D50 and / or content of the light diffusing agent included in the anti-glare layer forming the protective layer.

[0082] In one specific example, the protective layer may have an internal haze of 2.0 to 6.0%, for example, 2.5 to 5.0%. Within this range, the protective layer may be effective in preventing a decrease in panel brightness and a decrease in polarizer characteristics.

[0083] In one specific example, the protective layer may have an external haze of 18.0 to 44.0%, for example, 22 to 40%. In this range, the panel's reflectivity may be improved by a matte effect.

[0084] In one specific example, the protective layer may have an internal haze:external haze ratio of 1:7 to 1:10, for example, 1:8 to 1:9. In this range, the protective layer may be effective in improving panel reflection while preventing degradation of properties.

[0085] The above substrate layer can support an anti-glare layer and an anti-reflection layer.

[0086] The substrate layer may have an internal haze, an external haze, and an overall haze of 1% or less, for example, 0% to 0.5%. Within the above range, the overall haze and internal haze of the first protective film may not be affected.

[0087] The substrate layer may include a substrate film that is optically transparent, for example, having a light transmittance of 90% or more in the visible light range. The substrate layer may further include a coating layer formed on at least one surface of the substrate film.

[0088] In one specific embodiment, the substrate layer may be a substrate film alone. The substrate film may be a film comprising an optically transparent resin. For example, the substrate film may be a film made of one or more of a cellulose-based film including triacetyl cellulose (TAC), a polyester-based film including polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate, an acrylic-based film, a cyclic olefin polymer (COP)-based film, a cyclic olefin copolymer (COC)-based film, a polycarbonate-based film, a polyethersulfone-based film, a polysulfone-based film, a polyamide-based film, a polyimide-based film, a polyolefin-based film, a polyarylate-based film, a polyvinyl alcohol-based film, a polyvinyl chloride-based film, and a polyvinylidene chloride-based film. Preferably, the substrate film may be a polyethylene terephthalate or an acrylic-based film.

[0089] The base film can be stretched in one or two axes to provide the in-plane retardation described above. Specifically, the base film can be prepared by preparing an unstretched film from a base film composition including the resin, and stretching the prepared unstretched film in the machine direction (MD) 1-axis, the transverse direction (TD) 1-axis, or the MD and TD 2-axis. The stretching ratio can be appropriately selected in consideration of the thickness of the unstretched film, the target in-plane retardation, the stretching temperature, etc., and can be, for example, 2 to 7 times the stretching ratio, or 3 to 8 times the stretching temperature. The stretching temperature can be controlled according to the glass transition temperature (Tg) of the unstretched film, and can be, for example, Tg ± 20°C. The stretching can be performed by a conventional method known to those skilled in the art.

[0090] In one specific example, the substrate film, preferably the substrate layer, may have an in-plane retardation of 5,000 nm or more, specifically 5,000 nm to 15,000 nm, and more specifically 5,000 nm to 12,000 nm at a wavelength of 550 nm. Within this range, there may be effects such as an improvement in frontal contrast ratio and a suppression of rainbow mura.

[0091] In another embodiment, the substrate film, preferably the substrate layer, may have an in-plane retardation of less than 5,000 nm, specifically 0 to 1,000 nm, more specifically 0 to 50 nm but less than 100 nm, at a wavelength of 550 nm.

[0092] In another specific embodiment, the substrate layer may further include a primer layer as a coating layer. The primer layer may enhance adhesion to the adherend or the anti-glare layer. The primer layer may be formed from a composition containing a resin for the primer layer, such as a urethane-based, acrylic-based, or polyester-based resin, as long as it does not affect the effectiveness of the first protective film.

[0093] The substrate layer may have a thickness of 40 µm to 100 µm, preferably 50 µm to 90 µm. Within this range, the substrate layer may function as a support for the first protective film.

[0094] The anti-glare layer provides the overall haze of the protective layer.

[0095] The anti-glare layer is formed directly on the substrate layer. The term "directly formed" means that the anti-glare layer is directly laminated without any adhesive layer, bonding layer, adhesive layer, or any other optical layer between the substrate layer and the anti-glare layer. The anti-glare layer can be formed by directly coating the anti-glare layer composition on the substrate layer.

[0096] The antiglare layer may have a composition controlled on the surface of the antiglare layer and / or within the composition for the antiglare layer to achieve the overall haze and internal haze of the protective layer.

[0097] The antiglare layer includes a light diffusing agent having an average particle diameter D50 of 1.8 to 2.5 μm.

[0098] The reason this particle size is required is because Mie scattering is required during scattering. Mie scattering is caused by particles of similar size to the light intensity. Since the intensity of scattered light is inversely proportional to the wavelength, it is relatively less wavelength-dependent than ordinary scattering. Therefore, it is characterized by good scattering in the direction of light propagation, and because the surface is matte, it plays an important role in panel reflection.

[0099] If the average particle diameter D50 of the light diffuser is less than 1.8㎛, there may be a problem in that the amount of scattered light decreases because it falls short of the average particle diameter of the Mie scattering particles. If the average particle diameter D50 of the light diffuser exceeds 2.5㎛, the scattering uniformity decreases, which deteriorates the Mie scattering role. For example, the average particle diameter D50 of the light diffuser can be 1.8 to 2.5㎛.

[0100] In this specification, “average particle diameter (D50)” means a typical average particle diameter (D50) known to those skilled in the art, and means the particle diameter of the light diffusing agent corresponding to 50% by volume when the light diffusing agent is distributed in order from smallest to largest by volume.

[0101] The light diffuser may include at least one of organic particles and inorganic particles.

[0102] The organic particles may be included in the antiglare layer in an amount of 5 to 50 wt%, specifically 10 to 40 wt%, and more specifically 10 to 20 wt%. Within this range, an antiglare effect may be achieved.

[0103] The shape of organic particles is not particularly limited, such as spherical or amorphous.

[0104] The organic particles have a higher refractive index than the matrix for the antiglare layer, and the organic particles may have a refractive index of 1.30 to 1.70, specifically 1.40 to 1.60. Within the above range, the antiglare layer of the present invention can be easily achieved.

[0105] Organic particles can be appropriately selected and used from organic particles having the above-described refractive index.

[0106] For example, the organic particles may include core-shell type particles, but preferably, they may be non-core-shell type particles, that is, particles made entirely of a single material. The single material that makes up the organic particles may be particles of polyacrylate type, polymethacrylate type including polymethyl methacrylate (PMMA), polystyrene (PS) type, silicone type, polycarbonate type, polyolefin type, polyester type, polyamide type, polyimide type, polyfluoroethylene type, polymethyl methacrylate-polyacrylate type, polyacrylate-polystyrene type, melamine type, etc. Preferably, the organic particles may include at least one of polystyrene type particles, polyacrylate type particles, and polymethacrylate type particles.

[0107] The antiglare layer is composed of organic particles and an antiglare layer matrix in which the organic particles are dispersed, and the antiglare layer matrix may have a lower refractive index than the organic particles. The antiglare layer may be formed from a composition comprising organic particles and an active energy ray-curable compound. The active energy ray-curable compound may include at least one of an active energy ray-curable resin or oligomer, and an active energy ray-curable monomer. The active energy ray-curable resin or oligomer may be any of common types known to those skilled in the art.

[0108] The composition may further include at least one photoinitiator selected from the group consisting of a photoradical initiator and a photocationic initiator. The photoinitiator may cure an active energy ray-curable resin or an active energy ray-curable monomer. The photoradical initiator may include a photoradical initiator such as an acetophenone-based initiator or a cyclohexyl ketone-based initiator.

[0109] The composition may comprise, based on solid content, 5 to 50 wt%, specifically 10 to 40 wt%, more specifically 10 to 20 wt%, of organic particles, 20 to 80 wt%, specifically 50 to 70 wt%, of an active energy ray curable resin or oligomer, 10 to 80 wt%, specifically 10 to 30 wt%, of an active energy ray curable monomer, and 1 to 10 wt%, of a photoinitiator.

[0110] The composition for the anti-glare layer may include an appropriate solvent selected within a range that does not dissolve organic particles. The solvent is not particularly limited, but may include methyl ethyl ketone, propylene glycol methyl ether, and the like.

[0111] The composition for the anti-glare layer may further include conventional additives included in the anti-glare layer. The anti-glare layer may be formed by applying the composition for the anti-glare layer to one surface of the substrate layer, drying, and curing. Curing may be performed using conventional methods known to those skilled in the art, such as thermal curing or photocuring.

[0112] The antiglare layer may have a thickness of 1 to 8 μm, specifically 2 to 7 μm. Within the above range, the film may be included as an antiglare layer.

[0113] An anti-reflection layer can effectively implement the effects of the present invention by lowering the reflectivity of a polarizing plate having a protective layer. The protective layer may have a reflectivity of 2.5% or less, for example, 1 to 2%. The above "reflectivity" can be measured using a conventional method known to those skilled in the art.

[0114] The anti-reflection layer may be formed directly on the anti-glare layer. The term "directly formed" means that the anti-glare layer and the anti-reflection layer are directly laminated without any adhesive layer, bonding layer, adhesive layer, or any other optical layer between them. The anti-reflection layer may be formed by directly coating the anti-reflection layer composition on the anti-glare layer.

[0115] The antireflection layer may have a refractive index of 2.0 or less, for example, 1.2 to 1.4. Within this range, the reflectivity of the present invention can be easily achieved. The antireflection layer can provide the reflectivity of the film by controlling the composition of the antireflection layer composition.

[0116] The composition for the anti-reflection layer may include at least one of inorganic particles and a fluorine-based compound. The inorganic particles and the fluorine-based compound may lower the refractive index of the anti-reflection layer.

[0117] The inorganic particles may be hollow to have a low refractive index. For example, hollow silica may be preferred as a low refractive index inorganic particle. The refractive index may be less than 1.5, for example, from 1.0 to less than 1.5. Within this range, the refractive index of the antireflection layer can be easily lowered.

[0118] The inorganic particles have a low average particle diameter (D50) relative to the thickness of the antireflection layer, so that the surface roughness Sa of the antireflection layer can be easily reached. The average particle diameter (D50) of the inorganic particles may be 50 nm to 150 nm, for example, 50 nm to 120 nm.

[0119] The inorganic particles may be included in the antireflection layer at 30 to 70 wt%, for example, 40 to 60 wt%, for example, 50 to 60 wt%. Within this range, the reflectivity of the present invention can be easily achieved.

[0120] Fluorine compounds can easily lower the refractive index of an antireflection layer even when using a small amount of inorganic particles. The fluorine compounds may include fluorine-containing (meth)acrylate monomers, oligomers thereof, or resins thereof.

[0121] The composition for an anti-reflection layer may further include, in addition to inorganic particles and a fluorine-based compound, at least one of an active energy ray-curable resin or oligomer, an active energy ray-curable monomer, and a photoinitiator. The active energy ray-curable resin and the active energy ray-curable monomer can be cured to facilitate matrix formation of the anti-reflection layer and to stably incorporate low-refractive-index particles into the anti-reflection layer. The active energy ray-curable resin, the active energy ray-curable monomer, and the photoinitiator are substantially the same as those described for the anti-glare layer.

[0122] The composition for an anti-reflection layer may include, based on solid content, 20 to 80 wt% of at least one of an active energy ray-curable resin, an active energy ray-curable oligomer, and an active energy ray-curable monomer, 30 to 70 wt% of inorganic particles, specifically 50 to 70 wt%, 1 to 10 wt% of a fluorine-based compound, and 1 to 10 wt% of a photoinitiator. Within the above range, the anti-reflection layer of the present invention can be easily obtained.

[0123] The composition for an anti-reflection layer may further include conventional additives included in anti-reflection layers. For example, the additives may be conventional additives known to those skilled in the art to add anti-fouling properties and slimness to the anti-reflection layer. The additives may include at least one of a fluorine-containing additive and a silicone-based additive. The anti-reflection layer may be formed by applying the composition for an anti-reflection layer to one surface of a substrate layer, drying, and curing. Curing may be performed by conventional methods known to those skilled in the art, such as thermal curing or photocuring.

[0124] The anti-reflection layer may have a thickness of 60 nm to 200 nm, specifically 80 nm to 150 nm. Within the above range, the first protective film may be included as an anti-reflection layer.

[0125] 1st phase difference layer

[0126] The above first phase difference layer can be positioned between a polarizer and a panel for an optical display device to provide a circular polarization effect.

[0127] The above first phase difference layer may be a reverse wavelength dispersion phase difference layer. This can facilitate the polarizing plate to achieve a reflection color improvement effect.

[0128] According to one implementation, the first phase difference layer may have a short wavelength dispersion of 0.81 to 0.88, for example, 0.81 to 0.86, 0.81 to 0.84, and a long wavelength dispersion of 1.01 to 1.10, for example, 1.01 to 1.08, for example, 1.01 to 1.04. In the above range, it may be easy to improve light leakage and resolution. Here, the 'short wavelength dispersion' means Re(450) / Re(550), and the long wavelength dispersion means Re(650) / Re(550).

[0129] The first phase difference layer may have an in-plane phase difference of 135 to 145 nm, for example, 139 to 143 nm, at a wavelength of 550 nm. In this range, a circular polarization effect may be easily achieved.

[0130] The above first phase difference layer may include a liquid crystal layer or a non-liquid crystal layer. There is no limitation on the material of the liquid crystal layer and the non-liquid crystal layer as long as they can satisfy the wavelength dispersion and phase difference described above.

[0131] In one specific example, the first phase difference layer may be a liquid crystal layer or a non-liquid crystal layer.

[0132] In one specific example, the liquid crystal layer may include a cured product of a liquid crystal composition comprising at least one of a nematic liquid crystal, a smectic liquid crystal, a discotic liquid crystal, and a cholesteric liquid crystal. In addition, the liquid crystal layer may further include an alignment film to facilitate alignment of the liquid crystal within the liquid crystal layer. The production of the above-described liquid crystal layer and the above-described alignment film can be easily produced by referring to information known to those skilled in the art.

[0133] In another specific embodiment, the non-liquid crystal layer may be a film comprising an optically transparent resin. For example, the resin may include at least one of a cellulose-based resin including triacetyl cellulose, a polyester-based resin including polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate, and polybutylene naphthalate, a cyclic olefin polymer (COC)-based resin, a cyclic olefin polymer (COP)-based resin, a polycarbonate-based resin, a polyethersulfone-based resin, a polysulfone-based resin, a polyamide-based resin, a polyimide-based resin, a polyolefin-based resin, a polyarylate-based resin, a polyvinyl alcohol-based resin, a polyvinyl chloride-based resin, a polyvinylidene chloride-based resin, and an acrylic-based resin. For example, the non-liquid crystal layer may be a film that is uniaxially stretched in the MD or TD of an unstretched film, or a film that is biaxially stretched in the MD and TD.

[0134] For example, the non-liquid crystal layer may be a coating layer. For example, the non-liquid crystal layer may be a coating layer manufactured by coating a composition including at least one of a cellulose-based compound and a polystyrene-based compound as a main component, and then drying and / or curing the coating.

[0135] The first phase difference layer may have a thickness of 1 to 40 μm, for example, 1.5 to 35 μm. In the above range, it may be used in a polarizing plate.

[0136] The above polarizing plate may further include a second phase difference layer.

[0137] Second phase difference layer

[0138] The second phase difference layer may be positioned between the polarizer and the panel to further enhance the reflection color improvement effect of the polarizing plate. According to one embodiment, the second phase difference layer may be positioned between the polarizer and the first phase difference layer.

[0139] The second phase difference layer may be a positive C layer. The positive C layer is a phase difference layer that satisfies nz > nx = ny.

[0140] At the positive wavelength of 550 nm, the thickness direction phase difference can be -150 to -70 nm. In the above range, it can be easy to improve the viewing angle and light leakage from the side.

[0141] The above positive C layer can have an in-plane phase difference of 0 to 10 nm at a wavelength of 550 nm. In this range, it can be easy to improve the viewing angle and light leakage from the side.

[0142] The above positive C layer may be a liquid crystal layer or a non-liquid crystal layer. The liquid crystal layer and the non-liquid crystal layer are each substantially the same as those described for the first phase difference layer.

[0143] The above positive C layer may have a thickness of 1 to 60 μm, preferably 1 to 30 μm, and more preferably 1 to 10 μm. Within the above range, it may be applied to a polarizing plate, may facilitate the implementation of the phase difference of the present invention, and may facilitate the thinning of the polarizing plate.

[0144] Panel for optical display device

[0145] A panel for an optical display device may include a light-emitting layer including a light-emitting element. The light-emitting layer may include at least one of an organic light-emitting element, an inorganic light-emitting element, and an organic-inorganic light-emitting element.

[0146]

[0147] Fig. 1 is a cross-sectional view of an optical display device according to an embodiment. Referring to Fig. 1, the optical display device includes an optical display panel 100, a polarizing plate positioned on one surface of the optical display panel 100, and the polarizing plate may include a first phase difference layer 230, a polarizer 210, and a first protective layer 220 sequentially positioned from the optical display panel 100.

[0148] Fig. 2 is a cross-sectional view of an optical display device according to another embodiment. Referring to Fig. 2, the optical display device includes a panel 100 for an optical display device, a polarizing plate positioned on one surface of the panel 100 for an optical display device, and the polarizing plate may include a first phase difference layer 230, a second phase difference layer 240, a polarizer 210, and a first protective layer 220 sequentially positioned from the panel 100 for an optical display device.

[0149] Hereinafter, the structure and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, these are presented as preferred examples of the present invention and should not be construed as limiting the present invention in any way.

[0150] Example 1

[0151] (1) Manufacturing of polarizers

[0152] A polyvinyl alcohol film (Kuraray, degree of polymerization: 2800, thickness 45㎛) washed with water at 25°C was subjected to swelling treatment in a swelling tank with water at 30°C.

[0153] The film, which passed through the swelling tank, was treated for 65 seconds in a dyeing tank at 30°C containing an aqueous solution containing 1 mol / ml of potassium iodide and 1 wt% of boric acid. The film, which passed through the dyeing tank, was stretched at a stretch ratio of 5.7 times in a wet stretching tank containing an aqueous solution containing 3 wt% of boric acid at 60°C. The film, which passed through the wet stretching tank, was treated for 65 seconds in a crosslinking tank containing an aqueous solution containing 3 wt% of boric acid at 25°C.

[0154] The film passed through the crosslinking bath was treated for 10 seconds in a complementary bath containing a complementary solution, which is a 30°C aqueous solution containing 4.5 wt% potassium iodide. The film passed through the complementary bath was washed and dried with hot air at 80°C for 1 minute to produce a polarizer (thickness: 17 μm).

[0155] (2) Manufacturing of polarizing plates

[0156] A photocurable adhesive (epoxy resin adhesive) was applied to both sides of the polarizer manufactured above. A protective layer was adhered to the upper surface of the polarizer, and a liquid crystal phase difference layer was laminated to the lower surface of the polarizer to manufacture a polarizing plate.

[0157] The protective layer is a film in which a triacetyl cellulose film, an antiglare layer, and an antireflection layer are sequentially laminated as a substrate layer. The specific specifications of the protective layer are as shown in Table 1 below. The antiglare layer contains PMMA particles as a light diffusion agent. The protective layer has a total haze of 25%, an external haze of 22.3%, and an internal haze of 2.7%. The liquid crystal phase difference layer has reverse wavelength dispersion and an in-plane phase difference of 145 nm at a wavelength of 550 nm.

[0158] Examples 2 to 8

[0159] In Example 1, a polarizing plate was manufactured in the same manner as in Example 1, except that the degree of polymerization of the polyvinyl alcohol film and the concentration of potassium iodide in the complementary solution were changed as shown in Table 1 below when manufacturing the polarizer, and the average particle diameter D50 of the light diffusing agent in the antiglare layer was changed.

[0160] Comparative Examples 1 to 8

[0161] In Example 1, a polarizing plate was manufactured in the same manner as in Example 1, except that the degree of polymerization of the polyvinyl alcohol film and the concentration of potassium iodide in the complementary solution were changed as shown in Table 2 below when manufacturing the polarizer, and the average particle diameter D50 of the light diffusing agent in the antiglare layer was changed.

[0162] The properties below were evaluated using the liquid crystal phase difference layer and polarizing plate of the examples and comparative examples, and are shown in Table 1, Table 2, and Figures 3 to 6.

[0163] (1) Color dispersion: Color values ​​were measured in the polar angle (θ) 0° to 60° at the front and azimuth (Φ) 360 directions using a DMS (Display Measurement System) device. Then, the color dispersion was calculated using the formula above.

[0164] (2) Panel side reflection (unit: %): Reflectance was measured at a 60° angle using DMS (Display Measurement System) equipment. The higher the measured reflectance value, the better.

[0165] (3) Screen flash (Kiratsugi): It was evaluated as Level 1 to Level 3 by comparing it with the screen flash evaluation sample. If it was the same as the screen flash evaluation sample, it was evaluated as Level 1, if it was visible at a distance of 10 to 50 cm, it was evaluated as Level 2 (OK), and if it was visible at a distance of 50 cm or more, it was evaluated as Level 3 (NG).

[0166] Example 12345678Polarizer polymerization degree 28002800280028002800280032002800KI concentration (weight%) in complementary color tone 4.54.54.54.53.56.55.56.5ac value -0.83-0.83-0.83-1.540.262.353.03bc value -3.15-3.15-3.15-3.15-5.09-0.520.341.15Orthogonal transmittance 0.370.370.370.370.410.400.530.50Protective layer total Haze (%) 25 20 30 50 25 25 25 25 Light Diffusing Agent Particle Size (㎛) 2.0 2.0 2.0 2.0 2.1 2.0 2.0 2.0 2.0 Reflectance (%) 1.44 1.42 1.47 2.02 1.45 1.45 1.46 1.46 Color Dispersion 3.73 3.64 3.47 2.68 4.49 4.25 4.5 14.83 Panel Side Reflection 1.66 1.58 1.67 2.54 1.66 1.68 1.63 1.71 Screen Flash Lv2 Lv2 Lv2 Lv2 Lv2 Lv2 Lv2

[0167] Comparative Example 12345678Polarizer polymerization degree 2800 2800 2800 2800 3200 3200 3200 KI concentration (weight %) in complementary color tone 4.5 4.5 4.5 4.5 2.5 2.5 7.17 5 8.0 ac value - 1.02 - 1.02 - 1.02 - 3.26 - 2.5 3.43 3.5 2 3.5 9 bc value - 3.75 - 3.75 - 3.75 - 8.64 - 5.3 3 1.47 1.66 1.74 Orthogonal transmittance 0.47 0.47 0.47 0.42 0.46 0.5 2 0.5 3 0.5 2 Total protective layer Haze (%) 0.68 25 25 25 25 25 25 Light Diffusing Agent Particle Size (㎛) 02.0 3.9 2.0 2.0 2.0 2.0 Reflectance (%) 1.28 1.45 3.17 1.45 1.5 11.50 1.5 11.50 Color Dispersion 1.22 1.11 5.44 (NG) 5.3 (NG) 5.17 (NG) 5.10 (NG) 5.24 (NG) 5.22 (NG) Panel Side Reflection 0.25 (NG) 0.31 (NG) 1.63 1.75 1.75 1.73 1.73 1.72 Screen Flash Lv1 Lv2 Lv3 (NG) Lv2 Lv2 Lv2 Lv2

[0168]

[0169] As shown in Table 1 above, the optical display device of the embodiment has a low reflection color dispersion value between the front and side, a high panel side reflectance, and no screen glare. In addition, as shown in FIGS. 3 and 4, it can be confirmed that the reflection color dispersion value is low.

[0170] On the other hand, the optical display device of the comparative example had a higher reflection color dispersion value between the front and side compared to the embodiment, and / or had screen flicker and lower panel side reflection. In addition, as shown in FIGS. 5 and 6, it can be confirmed that the reflection color dispersion value was higher compared to the embodiment.

[0171]

[0172] Simple modifications or changes of the present invention can be easily implemented by a person having ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims

1. A panel for an optical display device, and a polarizing plate laminated on one surface of the panel for the optical display device, The polarizing plate includes a polarizer, a protective layer laminated on one side of the polarizer, and a first phase difference layer laminated on the other side of the polarizer. The polarizer has a color value ac of -2.0 to 3.3 and a color value bc of -5.5 to 1.5, The protective layer includes a substrate layer, an anti-glare layer, and an anti-reflection layer sequentially laminated from the polarizer, The above anti-glare layer comprises a light diffusing agent having an average particle diameter D50 of 1.8 to 2.5㎛, An optical display device, wherein the above protective layer has an overall haze of 20 to 50%.

2. An optical display device according to claim 1, wherein the polarizer has an orthogonal transmittance of 0.6% or less.

3. An optical display device according to claim 1, wherein the polarizer comprises a polyvinyl alcohol-based film having a polymerization degree of 2000 to 4000.

4. An optical display device according to claim 1, wherein the light diffusing agent comprises at least one of organic particles and inorganic particles.

5. An optical display device according to claim 1, wherein the light diffusing agent comprises at least one of polystyrene particles, polyacrylate particles, and polymethacrylate particles.

6. An optical display device according to claim 1, wherein the protective layer has an external haze of 18.0 to 44.0% and an internal haze of 2.0 to 6.0%.

7. An optical display device according to claim 1, wherein the protective layer has a reflectivity of 2.5% or less.

8. An optical display device according to claim 1, wherein the first phase difference layer is a reverse wavelength dispersion phase difference layer.

9. An optical display device according to claim 1, wherein the first phase difference layer has an in-plane phase difference of 135 to 145 nm at a wavelength of 550 nm.

10. An optical display device according to claim 1, further comprising a second phase difference layer between the polarizer and the first phase difference layer.

11. An optical display device according to claim 10, wherein the second phase difference layer is a positive C phase difference layer.

12. An optical display device according to claim 1, wherein the panel for the optical display device includes a light-emitting layer including a light-emitting element.

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