KR20230032599A - Polarizing plate and optical display apparatus comprising the same - Google Patents

Abstract

Provided are a polarizing plate and an optical display device including the same. The polarizing plate includes: a polarizer; and a first resin layer laminated on at least one surface of the polarizer, wherein the first resin layer includes one or more wires and fibers. At least a portion of one or more of the wires and fibers is oriented and aligned at an orientation angle (θ) with respect to the direction of the light absorption axis of the polarizer. The orientation angle (θ) is 65° to 115° or 0° to 25° with respect to the direction of the light absorption axis of the polarizer.

Description

Polarizing plate and optical display device including the same {POLARIZING PLATE AND OPTICAL DISPLAY APPARATUS COMPRISING THE SAME}

The present invention relates to a polarizing plate and an optical display device including the same.

The liquid crystal display device is driven by transmitting light from a backlight unit through a light source-side polarizing plate, a liquid crystal panel, and a viewer-side polarizing plate in this order. The light emitted from the light source is diffused and emitted while passing through the backlight unit, and then is incident on the light source-side polarizing plate. Therefore, there is a problem in that the contrast ratio and visibility decrease from the front to the side while passing through the light source-side polarizing plate, the liquid crystal panel, and the viewer-side polarizing plate.

A method of improving contrast ratio or visibility from the front and side views by including a contrast ratio or visibility improvement layer in the viewer-side polarizing plate is being considered. The contrast ratio or visibility improving layer improves contrast ratio and visibility by providing a predetermined embossed or engraved optical pattern at the interface between the low refractive index layer and the high refractive index layer so that light is refracted and emitted from the pattern when transmitted.

However, a contrast ratio or visibility improvement layer having a pattern necessarily includes a pattern manufacturing process. In addition, it must necessarily include two layers, a low refractive index layer and a high refractive index layer. In the pattern manufacturing process, a hard molding method and a soft molding method are used in which a pattern having a specific pitch is cut on a pattern roll and transferred to a film. However, if a minute defect occurs in the pattern roll during the pattern manufacturing process, the immediate defect is reflected in the transferred film, making it difficult to commercialize the product. Therefore, manufacturing of the polarizing plate may be complicated, additional costs may be required, and the thickness of the polarizing plate may be increased.

The background art of the present invention is disclosed in Korean Patent Publication No. 2018-0047569 and the like.

An object of the present invention is to provide a polarizing plate having improved contrast ratio and/or visibility even though it does not include an optical pattern or a pattern layer including the optical pattern.

Another object of the present invention is to provide a polarizing plate that does not have to include an optical pattern or pattern layer, thereby improving manufacturing processability of the polarizing plate and providing a thinning effect.

Another object of the present invention is to provide a polarizing plate that further improves contrast ratio and/or visibility without cloudiness.

Another object of the present invention is to provide a polarizing plate having improved luminance, contrast ratio, and viewing angle compared to a polarizing plate including an optical pattern or a pattern layer including an optical pattern.

One aspect of the present invention is a polarizing plate.

1. A polarizer is a polarizer; and a first resin layer laminated on at least one surface of the polarizer, wherein the first resin layer includes one or more of wires and fibers, and at least a portion of one or more of the wires and fibers. Is aligned and aligned at an orientation angle (θ) with respect to the light absorption axis direction of the polarizer, and the orientation angle (θ) is 65 ° to 115 ° or 0 ° to 25 ° with respect to the light absorption axis direction of the polarizer. .

In 2.1, the first resin layer may be a contrast ratio and/or visibility improving layer.

In 3.1-2, 60% by weight or more of the wires and fibers in the first resin layer may be aligned at the orientation angle θ with respect to the light absorption axis of the polarizer.

In 4.1-3, 80% by weight or more of the wires and fibers may be independently dispersed in the first resin layer.

In 5.1-4, the first resin layer may have a distance (ΔD) from the polarizer of 0 μm to 200 μm.

In 6.1-5, the first resin layer may have a refractive index of 1.40 to 1.80.

In 7.1-6, the wire or the fiber may have an aspect ratio of 500 or less.

In 8.1-7, one or more of the wires and fibers may be included in an amount of 1% to 40% by weight of the first resin layer.

In 9.1-8, the first resin layer may further include a matrix impregnated with one or more of the wires and fibers, and the refractive index of the one or more of the wires and fibers may be higher than that of the matrix.

In 10.1-9, the first resin layer may have a haze of 40% or less.

In 11.1-10, one or more of the wires and fibers may be formed of one or more of metals, nonmetals, metal oxides, nonmetal oxides, metal sulfides, nonmetal sulfides, metal nitrides, nonmetal nitrides, metal hydroxides, nonmetal hydroxides, and glass. can

In 12.1-11, at least one of the wire and fiber may be formed of zinc oxide.

In 13.1-12, the polarizing plate may include the polarizer and the first resin layer and the first protective layer sequentially stacked on the light exit surface of the polarizer.

In 14.13, the light exit surface of the first resin layer may be entirely flat.

In 15.14, the first resin layer and the first protective layer are formed by directly contacting each other, and the laminate of the first resin layer and the first protective layer may have a haze of 60% or less.

In 16.1-13, a second resin layer laminated on one side or the other side of the first resin layer may be further included.

In 17.16, a pattern portion may be formed at the interface between the first resin layer and the second resin layer.

At 18.17, the pattern portion may include a relief optical pattern and a separation surface formed immediately adjacent to the relief optical pattern.

19.17-18, the raised optical pattern may include a flat surface, a curved surface, or an angled surface.

In 20.17-19, the second resin layer may have a higher refractive index than the first resin layer.

In 21.16, the laminate of the first resin layer, the second resin layer, and the first protective layer may have a haze of 60% or less.

Another aspect of the present invention is an optical display device.

The optical display device includes the polarizing plate of the present invention.

The present invention provides a polarizing plate that improves contrast ratio and/or visibility even without including an optical pattern or a pattern layer including the optical pattern.

The present invention provides a polarizing plate that does not have to include an optical pattern or pattern layer, thereby improving manufacturing processability of the polarizing plate and providing a thinning effect.

The present invention provides a polarizing plate that further improves contrast ratio and/or visibility without cloudiness.

The present invention provides a polarizing plate having improved luminance, contrast ratio, and viewing angle compared to a polarizing plate including an optical pattern or a pattern layer including an optical pattern.

1 is a cross-sectional view of a polarizing plate according to an exemplary embodiment of the present invention.
FIG. 2 is a conceptual diagram of a distance ΔD in the polarizer of FIG. 1 .
3 is a cross-sectional view of a polarizing plate according to another embodiment of the present invention.
4 is a cross-sectional view of a polarizing plate according to another embodiment of the present invention.
FIG. 5 is a conceptual diagram of a distance ΔD of the polarizer of FIG. 4 .
FIG. 6 shows another form of an embossed optical pattern in the polarizer of FIG. 4 .
7 is a cross-sectional view of a polarizing plate according to another embodiment of the present invention.

With reference to the accompanying drawings, the embodiments will be described in detail so that those skilled in the art can easily carry out the embodiments. This invention may be embodied in many different forms and is not limited to the embodiments set forth herein.

In order to clearly describe the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are attached to the same or similar components throughout the specification.

In this specification, "upper" and "lower" are defined based on the drawings, and depending on the perspective, "upper" may be changed to "lower" and "lower" to "upper", and "on" or What is referred to as “on” may include not only immediately above but also the case of intervening other structures in the middle. On the other hand, what is referred to as "directly on", "directly on" or "directly formed" or "directly in contact with" means that no other structure is intervened.

In this specification, "horizontal direction" and "vertical direction" mean a long direction and a short direction of a rectangular liquid crystal display screen, respectively. In this specification, "front" and "side" are based on the horizontal direction, when the front is 0 °, the left end point is -90 °, and the right end point is 90 °, the side is -60 ^o or 60 ° it means.

In this specification, "refractive index" means a value measured with a refractometer at a wavelength of 550 nm.

In the present specification, "haze" may mean a value measured in a visible ray region, for example, a wavelength of 380 to 800 nm and 550 nm.

In this specification, “top part” means the highest part of the embossed optical pattern.

In this specification, "aspect ratio" means the ratio of the maximum height to the maximum width (maximum height/maximum width) of an embossed optical pattern.

In the present specification, "basic angle" means an angle formed between the maximum width of the optical pattern and an inclined surface directly connected to the maximum width of the optical pattern.

In this specification, "in-plane direction retardation (Re)" is a value at a wavelength of 550 nm, and is represented by the following formula A:

<Formula A>

Re = (nx - ny) x d

(In the above formula A, nx and ny are the refractive indices of the slow axis and fast axis directions of the protective layer at a wavelength of 550 nm, respectively, and d is the thickness of the protective layer (unit: nm)).

In this specification, “(meth)acryl” means an acryl and/or methacrylic.

In the present specification, when describing a numerical range, "X to Y" means "X≤ and ≤Y".

The inventors of the present invention have provided a polarizing plate that improves contrast ratio and/or visibility even without including an optical pattern or a pattern layer including the optical pattern. Since the polarizing plate of the present invention does not have to include an optical pattern or a pattern layer, manufacturing processability of the polarizing plate is improved and a thinning effect is provided. The polarizing plate of the present invention further improved contrast ratio and/or visibility by minimizing cloudiness. The inventors of the present invention provided a polarizing plate that improves contrast ratio and/or visibility compared to a polarizing plate including an optical pattern or a pattern layer including an optical pattern.

The polarizing plate of the present invention is a polarizer; and a first resin layer laminated on at least one surface of the polarizer, wherein the first resin layer includes one or more of wires and fibers, and at least a portion of one or more of the wires and fibers. Is aligned and aligned at an orientation angle (θ) with respect to the light absorption axis direction of the polarizer, and the orientation angle (θ) is 65 ° to 115 ° or 0 ° to 25 ° with respect to the light absorption axis direction of the polarizer. .

The wires and fibers each have a shape having a significantly large length-to-diameter ratio of 5 or more and 500 or less, respectively, thereby helping to improve the contrast ratio and visibility. In the present invention, a wire may be classified as having a diameter of 20 μm or less, preferably less than 10 μm, and a fiber having a diameter of 20 μm or less, preferably 10 μm or more.

Hereinafter, a polarizing plate according to an embodiment of the present invention will be described with reference to FIG. 1 .

Referring to FIG. 1, the polarizing plate includes a polarizer 100, a first resin layer 200 and a first protective layer 300 laminated on one surface of the polarizer 100, and a first laminated on the other surface of the polarizer 100. 2 may include a protective layer 400 .

One surface of the polarizer 100 may be a light exit surface of internal light of the polarizer when the polarizer is applied to an optical display device. Accordingly, the first resin layer 200 may be stacked on the light exit surface of the polarizer for internal light. However, the present invention is not limited thereto, and the first resin layer 200 may be laminated on the light incident surface of the internal light of the polarizer 100 . Preferably, the first resin layer 200 may be laminated on the light exit surface of the internal light of the polarizer. The "internal light" refers to light emitted from a light source such as a backlight unit and emitted through a polarizer.

First resin layer (200)

The first resin layer 200 may be included in the polarizer and function as a contrast ratio and/or visibility improvement layer.

The upper surface of the first resin layer 200 , that is, the light exit surface of the first resin layer 200 , as shown in FIG. 1 , has an upper surface and a lower surface as a whole and is not patterned. Nevertheless, the first resin layer 200 includes at least one of the wire 10 and the fiber, and at least one of the wire 10 and the fiber has an orientation angle among the first resin layer 200 ( θ), the contrast ratio and/or visibility may be improved.

At least some of the wires and fibers are oriented and aligned at an orientation angle θ with respect to the direction of the light absorption axis of the polarizer 100, and the orientation angle θ is 65° to 115° with respect to the direction of the light absorption axis of the polarizer. ° or 0° to 25°. Through this, it is possible to improve the contrast ratio and visibility of the light incident from the polarizer on the front and side surfaces. When the direction of the absorption axis of the polarizer is 0°, the orientation angle θ includes both clockwise + direction and counterclockwise - direction angles. The orientation of the wires and fibers can be confirmed using an optical microscope, but is not limited thereto. Preferably, the orientation angle θ may be 0° to 20° and 70° to 90°.

Referring to Figure 1, the orientation direction of the wire will be described. When the wires are oriented and aligned, the longitudinal direction of the wire is defined as an orientation direction. FIG. 1 shows a case in which at least a portion of wires are substantially parallel to and aligned in a direction of a light absorption axis of a polarizer in a polarizing plate.

In the first resin layer 200, 60% by weight or more, specifically 85% to 100% by weight of all wires and fibers may be aligned at an orientation angle θ with respect to the light absorption axis of the polarizer 100 . Within the above range, it is possible to provide an effect of improving contrast ratio and visibility while lowering the content of wires and fibers.

As described below, the wire or fiber has a shape in which the length to diameter is remarkably large, so that the internal light incident from the polarizer emits light to the front and side when it contacts the wire or fiber, thereby improving the contrast ratio and / or visibility. can help The shape may improve contrast and/or visibility from both front and side views. On the other hand, light diffusing particles having a rod shape (for example, an aspect ratio of less than 5) may have a weak effect of improving contrast ratio and/or visibility because the diameter-to-length of the wire is significantly small. Spherical light diffusing particles may also have a weak effect of improving contrast ratio and/or visibility.

The inventor of the present invention can improve the contrast ratio and visibility of the front and side surfaces of the internal light emitted from the polarizer without a conventional pattern layer by including wires or fibers in the first resin layer and adjusting the orientation angle (θ) of the wires or fibers. confirmed that there is

Hereinafter, a case in which the first resin layer 200 includes the wire 10 will be mainly described. However, the contents related to the wire 10 may be substantially equally applied to the fiber.

Among the first resin layer 200, the wires 10 may be at least independently dispersed. The "independently distributed" means that the wires are spaced apart so that the wires are not grounded together to form a network. When the wires are grounded to each other, light incident from the polarizer is non-uniformly emitted between the grounded portion and the non-grounded portion when contacting the wire, thereby deteriorating the effect of improving contrast ratio and visibility.

In one embodiment, 80% by weight or more of the total wires in the first resin layer 200, specifically 90% to 100% by weight may be independently dispersed. Within the above range, an effect of improving contrast ratio and visibility may be provided while reducing the amount of wire used.

The first resin layer 200 should be at a predetermined distance (ΔD) from the polarizer 100 . Through this, light incident from the polarizer is emitted in contact with the wire, thereby providing an effect of improving contrast ratio and visibility.

Referring to FIG. 2 , the distance ΔD of the first resin layer 200 from the polarizer 100 may be 0 μm to 200 μm, specifically 1 μm to 90 μm. Within this range, the contrast ratio and visibility can be improved by the wire acting on the light incident from the polarizer.

In one embodiment, as shown in FIG. 1 , when the first resin layer 200 directly contacts the polarizer as an adhesive layer or an adhesive layer, the distance ΔD may be 0 μm.

In another embodiment, when the first resin layer 200 is a non-adhesive layer or a non-adhesive layer and an adhesive layer is additionally laminated between the polarizer 100 and the first resin layer 200, the distance ΔD is 0 μm More than 200 μm or less, preferably 1 μm to 90 μm.

In another embodiment, as shown in FIG. 3, when the third protective layer 500 is additionally laminated between the first resin layer 200 and the polarizer 100, the distance ΔD is greater than 0 μm 200 μm or less, preferably 20 μm to 90 μm.

The first resin layer 200 may have a refractive index of 1.40 to 1.80, specifically 1.40 to 1.79, more specifically 1.45 to 1.70, or 1.45 to 1.69. By having an appropriate refractive index relative to the polarizer within the above range, even when the first resin layer 200 is stacked adjacent to the polarizer, the light transmittance of the polarizer may not be affected.

The first resin layer 200 may include a wire 10 and a matrix 20 impregnated with the wire 10 . Since the wire and the matrix have different refractive indices, it is possible to provide a greater effect in improving contrast ratio and visibility when light incident from the polarizer contacts the metal wire.

In one embodiment, the refractive index difference between the wire and the matrix may be 1.0 or less, specifically 0.1 to 0.7. Within this range, it may help to provide an effect of improving contrast ratio and visibility.

The wire 10 may help improve contrast ratio and visibility by having a wire shape in which the length to diameter is remarkably large.

In one embodiment, the wire is a nanowire or microwire, and the aspect ratio, which is the ratio of length to diameter, may be 500 or less, specifically 200 or less, more specifically 5 to 200, or 10 to 100. Within this range, contrast ratio and visibility may be improved, and wires may be easily oriented.

The wire may be a nanowire or microwire, and may have a diameter of 20 μm or less, specifically greater than 0 μm and less than or equal to 20 μm, more specifically 0.1 μm to 20 μm, or 0.5 μm to 1 μm. The wire may be 1 μm or more in length, specifically 5 μm to 4000 μm, more specifically 10 μm to 1000 μm. In this range, the above aspect ratio can be easily reached.

The wire 10 may be included in 1 wt% to 40 wt%, specifically 3 wt% to 15 wt%, and more specifically 4 wt% to 10 wt% of the first resin layer 200. Within this range, it may help to improve the contrast ratio and visibility, and it may be easy to adjust the haze described in detail below.

The wire 10 may have a high or low refractive index relative to the matrix. Preferably, the wire has a high refractive index compared to the matrix, thereby helping to improve the contrast ratio and visibility, and may not cause cloudiness.

In one embodiment, the wire 10 has a high refractive index compared to the matrix, and the wire may have a refractive index of 1.5 or more, specifically 1.5 to 2.3 or 1.52 to 2.3. In this range, the above refractive index difference can be easily reached.

In another embodiment, the wire 10 has a low refractive index relative to the matrix, and the wire may have a refractive index of 1.2 or more, specifically 1.4 to 1.6 or 1.43 to 1.6. In this range, the above refractive index difference can be easily reached.

The wire 10 may include a wire formed of at least one of metal, nonmetal, metal oxide, nonmetal oxide, metal sulfide, nonmetal sulfide, metal nitride, nonmetal nitride, metal hydroxide, nonmetal hydroxide, and glass. Preferably, in order to increase the effect of improving the contrast ratio and visibility, the first resin layer may include at least a metal oxide wire.

The metal may include one or more of silver, gold, zinc, platinum, nickel, copper, aluminum, tungsten, and calcium.

The non-metal may include one or more of silicon, indium, tin, germanium, and carbon.

The metal oxide may include at least one of zinc oxide (zinc oxide), copper oxide, aluminum oxide, nickel oxide, tungsten oxide, and calcium oxide.

The metal sulfide may include one or more of silver sulfide, zinc sulfide, nickel sulfide, copper sulfide, aluminum sulfide, and tungsten sulfide.

It may include one or more metals and functional group compounds having two or more chemical/physical bonds.

The matrix 20 may impregnate the wires so that the wires stably provide contrast and visibility effects.

The matrix may have a high or low index of refraction relative to the wire.

In one embodiment, the matrix has a high refractive index compared to the wire, and the matrix may have a refractive index of 1.5 or more, specifically 1.65 to 1.7. In this range, the above refractive index difference can be easily reached.

In other embodiments, the matrix has a low refractive index relative to the wire, and the matrix may have a refractive index of 1.2 or greater, specifically 1.4 to 1.60, more specifically 1.43 to 1.59. In this range, the above refractive index difference can be easily reached.

The matrix may be an adhesive layer or adhesive layer having adhesiveness or tackiness. In this case, the first resin layer may be directly laminated on the polarizer, thereby providing an effect of reducing the thickness of the polarizer. Preferably, the matrix may be formed of a pressure sensitive adhesive (PSA). However, the matrix may also be a non-adhesive layer or a non-adhesive layer having no adhesiveness or tackiness.

The matrix may be formed of a composition containing at least one of an ultraviolet curable resin and a thermosetting resin. For example, the matrix may be formed of a composition including a resin such as (meth)acrylic, urethane, epoxy, silicone, urethane (meth)acrylate, or epoxy (meth)acrylate. The composition may further include a photoinitiator, a thermal curing agent, and various additives. In one embodiment, the matrix can be directly laminated on the polarizer by being formed of a pressure sensitive adhesive (PSA) to become an adhesive layer.

In one embodiment, the matrix may be a composition for an adhesive layer comprising a (meth)acrylic copolymer formed of a monomer mixture including an alkyl group-containing (meth)acrylic monomer and a hydroxyl group-containing (meth)acrylic monomer and a curing agent. The first resin layer is formed by including a wire in the composition for the adhesive layer and then applying it, which can help orient the wire to the level of the present invention.

The first resin layer 200 may have light transmittance of 80% or more, specifically 90% to 100%. The first resin layer 200 may have a haze of 40% or less, specifically 0% to 35%, more specifically 10% to 30%. Within the above range, it can be applied to a polarizing plate, and has low cloudiness, so it can help provide an effect of improving contrast ratio and visibility.

The first resin layer 200 may have a thickness of 50 μm or less, specifically greater than 0 μm and less than or equal to 25 μm, and more specifically, 5 μm to 20 μm. Within the above range, it can be applied to a polarizing plate.

The top surface of the first resin layer 200, that is, the light exit surface of the wire-containing layer may be flat as shown in FIG. However, a predetermined pattern may be formed on the upper or lower surface of the first resin layer 200 to be patterned. This will be described in detail with reference to FIGS. 4, 6, and 7 below.

A lower surface of the first resin layer 200 may be flat as shown in FIG. 1 .

The first resin layer 200 may be formed by a conventional method using the above composition.

In one embodiment, the first resin layer 200 includes a wire in the matrix composition to prepare a composition for the first resin layer, and the composition for the first resin layer is added to the first protective layer 300 described in detail below. It may be formed by applying in a predetermined direction and then curing. The coating and curing may be performed by conventional methods known to those skilled in the art.

The first resin layer 200 may be formed as a coating layer on the first protective layer 300 . In one embodiment, the first resin layer may be formed by applying a composition for the first resin layer and then curing the first resin layer, thereby facilitating formation of the first resin layer of the present invention.

First protective layer (300)

The first protective layer 300 is laminated on the light exit surface of the internal light of the first resin layer 200 and may support the first resin layer 200 .

The light transmittance of the first protective layer 300 may be 80% or more, for example, 90% to 100%. Within this range, incident light can be transmitted without affecting it.

The first protective layer 300 may include a transparent substrate. The transparent substrate may have a different refractive index compared to the first resin layer 200 .

The transparent substrate may have a higher or lower refractive index compared to the first resin layer 200 . Preferably, the transparent substrate may have a higher refractive index than the first resin layer 200 . Through this, it may help to improve the contrast ratio and visibility.

The transparent substrate may include an optically transparent resin film having a light incident surface and a light exit surface opposite to the light incident surface. The transparent substrate may be formed of a single layer of resin film, or a plurality of resin films may be laminated. The resin includes a cellulose ester-based resin including triacetylcellulose (TAC), a cyclic polyolefin-based resin including an amorphous cyclic polyolefin (COP), a polycarbonate-based resin, and polyethylene terephthalate (PET). Polyacrylate-based resins, including polyester-based resins, polyethersulfone-based resins, polysulfone-based resins, polyamide-based resins, polyimide-based resins, acyclic-polyolefin-based resins, polymethyl methacrylate resins, etc. It may include one or more of vinyl alcohol-based resins, polyvinyl chloride-based resins, and polyvinylidene chloride-based resins, but is not limited thereto. Preferably, the transparent substrate includes a polyester-based resin including polyethylene terephthalate (PET), so that contrast ratio and visibility improvement effect can be further increased.

The transparent substrate may be an unstretched film, but may be a retardation film or an isotropic optical film having a retardation within a predetermined range by stretching the resin in a predetermined manner.

In one embodiment, the transparent substrate may be an isotropic optical film having Re of 0 nm or more and 60 nm or less, specifically, 40 nm to 60 nm. It is possible to improve the image quality by compensating the viewing angle within the above range. The "isotropic optical film" refers to a film in which nx, ny, and nz (nx, ny, and nz respectively mean refractive indices in the slow axis direction, the fast axis direction, and the thickness direction at a wavelength of 550 nm) are substantially the same, and the above "substantially "The same as" includes both the case of being completely identical as well as the case of including a slight error.

In another embodiment, the transparent substrate may be a retardation film having Re of 60 nm or more. For example, the transparent substrate may have Re of 60 nm to 500 nm or 60 nm to 300 nm. For example, the transparent substrate may have Re of 6,000 nm or more, 8,000 nm or more, specifically 10,000 nm or more, more specifically more than 10,000 nm, more specifically 10,100 nm to 30,000 nm, or 10,100 nm to 15,000 nm. Within this range, rainbow stains may not be visually recognized, and the effect of improving the contrast ratio and visibility of light diffused through the first resin layer may be increased.

The transparent substrate may have a haze of 30% or less, specifically 0.1% to 30%. Within the above range, it can be applied to a polarizing plate.

The thickness of the transparent substrate may be 5 μm to 200 μm, for example, 10 μm to 90 μm. Within this range, it can be used for a polarizing plate.

The first protective layer 300 may further include a transparent substrate and a functional layer laminated on at least one surface of the transparent substrate. The functional layer may include at least one of a hard coating layer, a scattering layer, a low reflection layer, an ultra low reflection layer, a primer layer, an anti-fingerprint layer, an antireflection layer, and an antiglare layer.

The first protective layer 300 may have a haze of 30% or less, specifically 0.1% to 30%, or 0.5% to 20%. Within the above range, it can be applied to a polarizing plate, and has low cloudiness, so it can help provide an effect of improving contrast ratio and visibility.

The laminate of the first resin layer 200 and the first protective layer 300 may have a haze of 60% or less, specifically 0.1% to 55%, 0.1% to 45%, or 10% to 40%. Within the above range, it can be applied to a polarizing plate, and has low cloudiness, so it can help provide an effect of improving contrast ratio and visibility. The 'haze' may be implemented by adjusting the content of wires in the first resin layer, the type of functional layer in the first protective layer, and the haze of the transparent substrate.

Preferably, the laminate is at least one of a first resin layer, a transparent substrate, and a low reflection layer, an ultra-low reflection layer, an antireflection layer, and an antiglare layer laminated on the light exit surface of the transparent substrate, more preferably an antireflection layer. , may include a low reflection layer or an ultra low reflection layer. At this time, the reflectance of the first protective layer 300 may be 5% or less, specifically 0.1% to 3%. Within the above range, visibility of the wire in the first resin layer may be reduced.

Polarizer (100)

The polarizer 100 may polarize light incident from the liquid crystal panel and transmit it through the first resin layer 200 . The polarizer 100 may be stacked on the light incident surface of the first resin layer 200 for internal light. A light absorption axis of the polarizer 100 may be a machine direction (MD) of the polarizer.

The polarizer 100 may include a polyvinyl alcohol-based polarizer manufactured by uniaxially stretching a polyvinyl alcohol-based film.

The polarizer 100 may have a thickness of 5 μm to 40 μm. Within this range, it can be used in an optical display device.

Although not shown in FIG. 1 , the above-described first protective layer may be further stacked on the upper surface of the polarizer, that is, the light exit surface of the polarizer.

Second protective layer (400)

The second protective layer 400 may be stacked on the light incident surface of the polarizer 100 for internal light.

The light transmittance of the second protective layer 400 may be 80% or more, for example, 90% to 100%. Within this range, incident light can be transmitted without affecting it.

The second protective layer 400 may include a transparent substrate. The transparent substrate may include an optically transparent resin film having a light incident surface and a light exit surface opposite to the light incident surface. The transparent substrate may be formed of a single layer of resin film, or a plurality of resin films may be laminated. The resin includes a cellulose ester-based resin including triacetylcellulose (TAC), a cyclic polyolefin-based resin including an amorphous cyclic polyolefin (COP), a polycarbonate-based resin, and polyethylene terephthalate (PET). Polyacrylate-based resins, including polyester-based resins, polyethersulfone-based resins, polysulfone-based resins, polyamide-based resins, polyimide-based resins, acyclic-polyolefin-based resins, polymethyl methacrylate resins, etc. It may include one or more of vinyl alcohol-based resins, polyvinyl chloride-based resins, and polyvinylidene chloride-based resins, but is not limited thereto. Preferably, the transparent substrate includes a polyester-based resin including polyethylene terephthalate (PET), so that contrast ratio and visibility improvement effect can be further increased.

The transparent substrate may be an unstretched film, but may be a retardation film or an isotropic optical film having a retardation within a predetermined range by stretching the resin in a predetermined manner.

In one embodiment, the transparent substrate may be an isotropic optical film having Re of 0 nm or more and 60 nm or less, specifically, 40 nm to 60 nm. It is possible to improve the image quality by compensating the viewing angle within the above range. The "isotropic optical film" refers to a film in which nx, ny, and nz (nx, ny, and nz respectively mean refractive indices in the slow axis direction, the fast axis direction, and the thickness direction at a wavelength of 550 nm) are substantially the same, and the "substantially "The same as" includes both the case of being completely identical as well as the case of including a slight error.

In another embodiment, the transparent substrate may be a retardation film having Re of 60 nm or more. For example, the transparent substrate may have Re of 60 nm to 500 nm or 60 nm to 300 nm. For example, the transparent substrate may have Re of 6,000 nm or more, 8,000 nm or more, specifically 10,000 nm or more, more specifically more than 10,000 nm, more specifically 10,100 nm to 30,000 nm, or 10,100 nm to 15,000 nm. Within this range, rainbow stains may not be visually recognized, and the effect of improving the contrast ratio and visibility of light diffused through the first resin layer may be increased.

The thickness of the transparent substrate may be 5 μm to 200 μm, for example, 10 μm to 90 μm. Within this range, it can be used for a polarizing plate.

Hereinafter, a polarizing plate according to another embodiment of the present invention will be described with reference to FIG. 3 .

Referring to Figure 3, the polarizing plate is a polarizer 100; A third protective layer 500, a first resin layer 200 and a first protective layer 300 laminated on one surface of the polarizer 100; and a second protective layer 400 stacked on the other side of the polarizer 100 . It is substantially the same as the polarizer of FIG. 1 except that a third protective layer 500 is further laminated between the polarizer 100 and the first resin layer 200 . Hereinafter, only the third protective layer 500 will be described.

The light transmittance of the third protective layer 500 may be 80% or more, for example, 90% to 100%. Within this range, incident light can be transmitted without affecting it.

The third protective layer 500 may include a transparent substrate. The transparent substrate of the third protective layer 500 may include a film formed of the same or different resin as the transparent substrate of the second protective layer 400 . The transparent substrate of the third protective layer 500 may have the same or different type of Re as that of the transparent substrate of the second protective layer 400 .

Hereinafter, a polarizing plate according to another embodiment of the present invention will be described with reference to FIG. 4 .

Referring to Figure 4, the polarizing plate is a polarizer 100; A first resin layer 210 and a first protective layer 300 laminated on one surface of the polarizer 100; And a second protective layer 400 laminated on the other surface of the polarizer 100, one surface of the first resin layer 210 is patterned in a predetermined pattern, and the first resin layer 210 and the second The space between the first protective layer 300 may be filled with the second resin layer 600 .

One surface of the first resin layer 210, that is, the light exit surface of the internal light, which is the upper surface of the first resin layer 210 (the surface in contact with the second resin layer 600), is patterned, and the first resin layer ( 210) and the first protective layer 300, the second resin layer 600 is further stacked in the space between them, and is substantially the same as that of the polarizing plate of FIG. 1. Accordingly, only the first resin layer 210 and the second resin layer 600 will be described below.

First resin layer (210)

The first resin layer 210 may be included in the polarizer and function as a contrast ratio and/or visibility improvement layer. Since the wire has a wire shape having a significantly large length compared to the diameter, contrast ratio and/or visibility may be improved by emitting light to the front and side when internal light incident from the polarizer contacts the metal nanowire. The wire shape may improve contrast ratio and/or visibility from both front and side views. The rod-shaped light diffusing particles have a significantly smaller diameter-to-length than the metal wire, and the effect of improving contrast ratio and/or visibility may be weak. Spherical light diffusing particles may also have a weak effect of improving contrast ratio and/or visibility.

Among the first resin layer 210 , wires are included in the first resin layer 210 oriented and aligned at an orientation angle θ.

Specifically, at least a portion of the wire is oriented and aligned at an orientation angle (θ) of 65 ° to 115 ° or 0 ° to 25 ° with respect to the light absorption axis of the polarizer 100, so that at the front and side of the light incident from the polarizer contrast ratio and visibility can be improved. Preferably, the orientation angle θ may be 0° to 20° and 70° to 90°.

In one embodiment, 60% by weight or more, specifically 85% to 100% by weight of the wires in the first resin layer 210 are arranged substantially perpendicular or substantially parallel to the light absorption axis of the polarizer 100 may be sorted. Within the above range, an effect of improving contrast ratio and visibility may be provided while reducing the amount of wire used. FIG. 4 shows a case in which at least a portion of the wires are substantially vertically arranged and aligned in the direction of the light absorption axis of the polarizer of the polarizer.

Wires in the first resin layer 210 may be at least independently dispersed. The “independently dispersed” is the same as described in FIG. 1 . In one embodiment, 80% by weight or more, specifically 90% by weight to 100% by weight of the first resin layer 210 to the wire may be independently dispersed. Within the above range, an effect of improving contrast ratio and visibility may be provided while reducing the amount of wire used.

The first resin layer 210 should be at a predetermined distance (ΔD) from the polarizer 100 . Through this, contrast ratio and visibility may be improved by emitting light incident from the polarizer through the wire.

Referring to FIG. 5, the first resin layer 210 has a distance ΔD from the polarizer 100 (eg, the distance between the lower surface of the first resin layer 210 and the polarizer 100). It may be 0 μm to 200 μm, specifically 1 μm to 90 μm. Within the above range, the contrast ratio and visibility may be improved by the metal wire acting on the light incident from the polarizer.

The first resin layer 210 may have a refractive index of 1.40 to 1.80, specifically 1.40 to 1.79, 1.45 to 1.70, or 1.45 to 1.69. By having an appropriate refractive index compared to the polarizer within the above range, the light transmittance of the polarizer may not be affected even when the first resin layer 210 is stacked adjacent to the polarizer.

The first resin layer 210 may include a wire 10 and a matrix 20 impregnated with the wire 10 . Since the wire and the matrix have different refractive indices, it is possible to provide a greater effect in improving contrast ratio and visibility when light incident from the polarizer contacts the metal wire. In one embodiment, the refractive index difference between the wire and the matrix may be 1.0 or less, specifically 0.1 to 0.7. Within this range, it may help to provide an effect of improving contrast ratio and visibility.

The wire may have the aspect ratio, diameter and length described in FIG. 1 . The wire may be included in an amount of 1 wt % to 40 wt %, specifically 3 wt % to 15 wt %, of the first resin layer 200 . Within this range, it may help to improve the contrast ratio and visibility, and it may be easy to adjust the haze described in detail below.

The wire may have a high or low refractive index relative to the matrix. Preferably, the wire has a high refractive index compared to the matrix, thereby helping to improve the contrast ratio and visibility, and may not cause cloudiness.

In one embodiment, the wire has a high refractive index relative to the matrix, and the wire may have a refractive index of 1.5 or more, specifically 1.52 to 2.3. In this range, the above refractive index difference can be easily reached. In another embodiment, the wire has a low refractive index relative to the matrix, and the wire may have a refractive index of 1.2 or greater, specifically 1.43 to 1.6. In this range, the above refractive index difference can be easily reached.

The wire may include one or more types of wires described in FIG. 1 .

The matrix may have the refractive index described in FIG. 1 and may be formed of the material described in FIG. 1 .

The top surface of the first resin layer 210 may be patterned to form a pattern portion.

The effect of improving the contrast ratio and visibility due to the wire may be further increased in the pattern unit.

Referring to FIG. 6 , a combination of an embossed optical pattern 211 and a separation surface 212 formed immediately adjacent to the embossed optical pattern may be repeatedly disposed in the pattern unit. The second resin layer 600 has a different refractive index compared to the first resin layer 210. In the embossed optical pattern 211, the light emitted by contacting the wire reaches a predetermined pattern and then is refracted to the second resin layer 600. Contrast ratio and visibility can be further improved by allowing the light to be emitted to the resin layer.

The embossed optical pattern 211 may be an optical pattern protruding from the first resin layer 210 to the second resin layer 600 . The embossed optical pattern 211 includes an inclined surface 213 formed directly on the separation surface 212, and the inclined surface 213 may be a flat surface, a curved surface, or an angled plane. Through this, light incident from the first resin layer to the second resin layer is refracted, thereby improving the contrast ratio and visibility from the front and side surfaces.

When the angle formed by the inclined surface 213 and the maximum width W1 of the embossed optical pattern 211 is referred to as the base angle θ1, the 'base angle θ1' is 60° to 90°, specifically 75° or more and 90°. less than, more specifically 75° to 85°. Within this range, it may help to improve the contrast ratio and visibility.

6(A) shows a case where the inclined surface is a single flat surface and the embossed optical pattern has a trapezoidal shape. However, the embossed optical pattern may be an N-gonal (N is an integer of 4 to 10) cross-section including a trapezoid, a rectangle, a square, etc. with a flat surface formed at the apex as well as a triangular pattern in cross-section.

The embossed optical pattern 211 may have an aspect ratio (H/W1) of a height to a maximum width of 3 or less, specifically 0.3 to 3, 0.4 to 2, and more specifically 0.6 to 1.3. Within the above range, it may help to improve the contrast ratio and visibility of the present invention.

The embossed optical pattern 211 may satisfy Equation 1 below: Satisfying Equation 1 may help to improve the lateral contrast ratio and increase the contrast ratio at the same lateral viewing angle. Preferably, P1/W1 (the ratio of P1 to W1) can be from 1.2 to 8:

[Equation 1]

1 < P1/W1 ≤ 10

(In Equation 1 above,

P1 is the period of the pattern part (unit: μm),

W1 is the maximum width of the embossed optical pattern (unit: µm).

The embossed optical pattern 211 may have a height H of 40 μm or less, specifically 30 μm or less, and more specifically, 3 μm to 25 μm. Within the above range, it may help to improve contrast ratio, viewing angle, and luminance. The embossed optical pattern may have a maximum width W1 of 50 μm or less, specifically 30 μm or less, and more specifically, 3 μm to 15 μm or 15 μm to 25 μm. Within this range, contrast ratio improvement, viewing angle improvement, and luminance improvement may be exhibited, and moiré and the like may not appear. The embossed optical pattern may have a period (W1 + L) of 50 μm or less, specifically 30 μm or less, and more specifically, 3 μm to 15 μm or 15 μm to 25 μm. Within this range, contrast ratio improvement, viewing angle improvement, and luminance improvement may be exhibited, and moiré and the like may not appear.

The embossed optical pattern 211 may have a first surface 214 provided at the top. The first surface 214 can be flat, angled, or curved. The maximum width W2 of the first surface 214 may be 50 μm or less, specifically 30 μm or less, and more specifically 3 μm to 15 μm or 15 μm to 25 μm. Within the above range, it may help to improve the contrast ratio and visibility of the present invention.

Wires may be dispersed and included in the embossed optical pattern 211 . The wires are oriented and aligned at an orientation angle θ with respect to the direction of the light absorption axis of the polarizer 100, and the orientation angle θ is 65° to 115° or 0° to 0° to the direction of the light absorption axis of the polarizer. It is 25°. Within the above range, the contrast ratio and visibility of the light incident from the polarizer in the front and side views may be improved. The embossed optical pattern may include the aforementioned wire and the aforementioned matrix. Preferably, the orientation angle θ may be 0° to 20° and 70° to 90°.

The separation surface 212 may emit light incident vertically from the first resin layer to increase contrast ratio and visibility from the front. The maximum width L of the separation surface 212 may be 50 μm or less, specifically 30 μm or less, and more specifically 2 μm to 15 μm or 15 μm to 25 μm. Within this range, the effects of the present invention can be easily implemented.

In the first resin layer 210, wires are dispersed in the remaining area except for the embossed optical pattern 211, that is, in the area between the lower surface and the separation surface of the first resin layer 210 and the maximum width of the embossed optical pattern. can be included The wires are oriented and aligned at the orientation angle θ relative to the absorption axis of the polarizer, thereby improving the contrast ratio and visibility of light incident from the polarizer on the front and side surfaces.

Although the embossed optical pattern 211 is not shown in FIG. 4 , it may be formed in a stripe-shaped extension in the length direction of the optical pattern. Through this, an effect of improving the left and right viewing angles may be obtained. The "longitudinal direction of the optical pattern" means a direction different from, for example, a direction orthogonal to the maximum width direction of the embossed optical pattern. FIG. 4 illustrates a case in which a light absorption axis of a polarizer and a longitudinal direction of an embossed optical pattern are substantially orthogonal to each other.

In one embodiment, the angle between the longitudinal direction of the embossed optical pattern and the absorption axis of the polarizer 100 is 0° when the absorption axis of the polarizer is 0°, and the orientation angle θ is 0° to 20°, 70° to 90°. Within the above range, it is possible to avoid the pixel moiré phenomenon with the liquid crystal panel.

Referring to (B) and (C) of FIG. 6 , when the inclined surface is an angled plane, the inclined surface may be convex from the first resin layer 210 toward the second resin layer 600 . However, a case where the inclined surface is convex from the second resin layer 600 side to the first resin layer 210 side may also be included in the scope of the present invention.

Referring to (D) and (E) of FIG. 6 , when the inclined surface is a curved surface, the embossed optical pattern is a convex curved surface from the first resin layer 210 to the second resin layer 600 ((D) of FIG. 6 ). ) or a convex curved surface from the second resin layer 600 to the first resin layer 210 ((E) in FIG. 6).

The second resin layer 600 may fill at least a part of the space between the embossed optical pattern 211 and the first protective layer 300 . In one embodiment, the lower surface of the second resin layer 600 may be patterned by the above-described pattern unit.

The second resin layer 600 may or may not include wires. Preferably, since the second resin layer 600 does not include a wire, there may be no problem in visibility of the wire due to excessive use of the wire.

The second resin layer 600 may have a refractive index different from that of the first resin layer 210 . The second resin layer 600 may have a higher refractive index or a lower refractive index than the first resin layer 210 . Preferably, the refractive index of the second resin layer 600 is higher than that of the first resin layer 210, and the contrast ratio and visibility improvement effect can be further increased.

The difference in refractive index between the second resin layer 600 and the first resin layer 210 may be 0.05 to 0.2, specifically 0.1 to 0.16. Within the above range, the effect of improving the contrast ratio and visibility may be further increased.

In one embodiment, the second resin layer 600 may have a refractive index of 1.4 or more, specifically 1.5 to 1.7, and more specifically 1.58 to 1.66. In this range, the above refractive index difference can be easily reached.

The second resin layer 600 may be formed of a composition containing at least one of an ultraviolet curable resin and a thermosetting resin. For example, the second resin layer 600 may be formed of a composition including a resin such as (meth)acrylic, urethane, epoxy, silicone, urethane (meth)acrylate, or epoxy (meth)acrylate. there is. The composition may further include a photoinitiator, a thermal curing agent, and various additives.

The laminate of the first resin layer 210, the second resin layer, and the first protective layer 300 may have a haze of 60% or less, specifically 1% to 50%, or 30% to 50%. Within the above range, it can be applied to a polarizing plate, and has low cloudiness, so it can help provide an effect of improving contrast ratio and visibility.

Preferably, the laminate includes at least one of a first resin layer, a second resin layer, a transparent substrate, and a low reflection layer, an ultra-low reflection layer, an antireflection layer, and an antiglare layer laminated on the light exit surface of the transparent substrate. Preferably, a low reflection layer or an ultra low reflection layer may be included. At this time, the reflectance of the first protective layer 300 may be 5% or less, specifically 0.1% to 3%. Within the above range, visibility of the wire in the first resin layer may be reduced.

The maximum thickness of the second resin layer 600 may be greater than 0 μm and less than 50 μm, for example greater than 0 μm and less than 30 μm. Within this range, occurrence of warpage such as curl can be prevented.

The maximum thickness of the second resin layer 600 - The maximum height (also referred to as 'flesh thickness') of the embossed optical pattern 211 is 0 μm to 30 μm, for example, greater than 0 μm and less than or equal to 20 μm, greater than 0 μm and less than 10 μm It can be less than a micron. Within the above range, an effect of increasing the surface hardness and sufficient adhesion to the protective film can be expected.

Referring to FIG. 7 , a polarizing plate according to another embodiment of the present invention will be described.

Referring to FIG. 7 , the polarizing plate includes a polarizer 100; A first resin layer 210 and a first protective layer 300 laminated on one surface of the polarizer 100; And a second protective layer 400 laminated on the other side of the polarizer 100, one side of the first resin layer 210 is patterned in a predetermined pattern, and the first resin layer 210 and the polarizer The space between (100) may be filled with the second resin layer (600).

The other surface of the first resin layer 210, that is, the lower surface of the first resin layer 210, the light incident surface of the internal light (the surface in contact with the second resin layer 600) is patterned, and the first resin layer 210 is patterned. It is substantially the same as the polarizing plate of FIG. 4 except that the second resin layer 600 is further stacked in the space between 210 and the polarizer 100 .

Although not shown in the present invention, the polarizer in FIG. 7 may also have the shape of the embossed optical pattern described in FIG. 6 .

The optical display device of the present invention includes the polarizing plate of the present invention.

In one embodiment, the optical display device of the present invention may include the polarizing plate of the present invention as a viewer-side polarizing plate for a liquid crystal panel. The "visible-side polarizing plate" is a polarizing plate disposed facing the screen side of the liquid crystal panel, that is, the light source side.

In one embodiment, the liquid crystal display device may include a condensing backlight unit, a light source-side polarizing plate, a liquid crystal panel, and a viewing-side polarizing plate sequentially stacked, and the viewing-side polarizing plate may include the polarizing plate of the present invention. The "light source-side polarizing plate" is a polarizing plate disposed on the light source side. The liquid crystal panel may employ VA (vertical alignment) mode, IPS mode, PVA (patterned vertical alignment) mode, or S-PVA (super-patterned vertical alignment) mode, but is not limited thereto.

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, the following examples are provided to aid understanding of the present invention, and the scope of the present invention is not limited to the following examples.

Example 1

(1) A polyethylene terephthalate (PET) film (product name: DSG-23, manufacturer: DAI NIPPON PRINTING CO., LTD., haze: 0.6%) having an antireflection layer formed on the upper surface was prepared.

A composition for a first resin layer was prepared by mixing a composition containing zinc oxide wire (aspect ratio of zinc oxide wire: 90, diameter of zinc oxide wire: 0.7 μm) with an acrylic pressure-sensitive adhesive composition.

A first resin layer containing a matrix (refractive index: 1.47) and zinc oxide wire (refractive index: 2.0) on the lower surface of the PET film by applying the composition for the first resin layer in one direction to the lower surface of the PET film and drying the composition. (refractive index: 1.48) was formed. The haze of the antireflection layer - PET film - first resin layer was 17%.

(2) A polarizer (thickness: 13 μm, light transmittance: 44%) was prepared by stretching a polyvinyl alcohol-based film 3 times at 60° C., adsorbing iodine, and then stretching it 2.5 times in a boric acid solution at 40° C.

A polyethylene terephthalate (PET) film (product name: TA-053, manufacturer: TOYOBO CO., LTD.) was adhered to the upper surface of the polarizer prepared above, and a cyclic olefin polymer (COP) film (manufacturer : ZEON Corporation) was bonded to prepare a laminate laminated in the order of PET film - polarizer - COP film.

(3) A polarizing plate in which the antireflection layer - PET film - first resin layer - PET film - polarizer - COP film is sequentially stacked is manufactured by laminating the PET film and the first resin layer containing zinc oxide wire among the laminates. did The orientation angle (θ) is 0°.

Example 2

In Example 1, a polarizing plate was manufactured in the same manner as in Example 1, except that the orientation angle (θ) was 90°.

Example 3

In Example 1, a polarizing plate was manufactured in the same manner as in Example 1, except that the haze of the antireflection layer - PET film - first resin layer was changed to 32% by changing the content of the zinc oxide wire.

Example 4

In Example 1, a polarizing plate was manufactured in the same manner as in Example 1, except that the orientation angle (θ) was changed to 20°.

Example 5

In Example 1, a polarizing plate was manufactured in the same manner as in Example 1, except that the orientation angle (θ) was changed to 70°.

Example 6

(1) A polyethylene terephthalate (PET) film (product name: DSG-23, manufacturer: DAI NIPPON PRINTING CO., LTD, haze: 0.6%) having an antireflection layer formed on the upper surface was prepared. A composition for a second resin layer was coated on the lower surface of the PET film to a predetermined thickness, applied with a pattern, and cured to form a second resin layer (refractive index: 1.59).

A composition for a first resin layer was prepared by mixing a composition containing zinc oxide wire (aspect ratio of zinc oxide wire: 90, diameter of zinc oxide wire: 0.7 μm) with an acrylic pressure-sensitive adhesive composition. The composition for the first resin layer is applied in one direction to the lower surface of the second resin layer and dried to form a first layer containing a matrix (refractive index: 1.47) and zinc oxide wire (refractive index: 2.0) on the lower surface of the PET film. A resin layer (refractive index: 1.48) was formed.

Through this, a laminate was prepared in which the antireflection layer - the PET film - the second resin layer - the first resin layer were laminated in the order, and the haze was 41%.

Table 1 below shows the detailed configuration of the pattern part.

H W1 W2 L θ1 10.4㎛ 10.2㎛ 9.3㎛ 9.8㎛ 85°

(2) In the same manner as in Example 1, a laminate was prepared in the order of PET film - polarizer - COP film.

(3) The first resin layer of the laminate and the PET film of the laminate are laminated, and the antireflection layer - PET film - second resin layer - first resin layer - PET film - polarizer - COP film are sequentially laminated. A polarizing plate was prepared. The orientation angle (θ) is 0°.

Example 7

In Example 6, a polarizing plate was manufactured in the same manner as in Example 6, except that the haze of the antireflection layer - PET film - second resin layer - first resin layer was changed to 52% by changing the content of the zinc oxide wire. did

Comparative Example 1

In Example 1, a polarizing plate was manufactured in the same manner as in Example 1 except that the antireflection layer - PET film - adhesive layer - PET film - polarizer - COP film were sequentially laminated. The adhesive layer was made of the acrylic pressure-sensitive adhesive composition in Example 1.

Comparative Example 2

In Example 1, a polarizing plate was manufactured in the same manner as in Example 1, except that the orientation angle (θ) was changed to 30°.

Comparative Example 3

In Example 1, a polarizing plate was manufactured in the same manner as in Example 1, except that the orientation angle (θ) was changed to 60°.

Comparative Example 4

In Example 6, a polarizing plate was manufactured in the same manner as in Example 4, except that the zinc oxide wire was not included in the first resin layer.

Comparative Example 5

In Example 1, a polarizing plate was manufactured in the same manner as in Example 1, except that a zinc oxide rod (aspect ratio: 1.3) was included instead of the zinc oxide wire.

For the polarizers prepared in Examples and Comparative Examples, models for measuring viewing angles were prepared, and physical properties in Table 2 below were evaluated.

Light source side polarizer

A polarizer was prepared by stretching a polyvinyl alcohol film 3 times at 60° C., adsorbing iodine, and then stretching the polyvinyl alcohol film 2.5 times in an aqueous solution of boric acid at 40° C. A polarizing plate was prepared by attaching a triacetylcellulose film (80 μm in thickness) as a substrate layer to both sides of the polarizer with an adhesive for polarizing plates (Z-200, Nippon Goshei Co.). The prepared polarizing plate was used as a light source-side polarizing plate.

Viewer side polarizer

As the viewer-side polarizing plate, the polarizing plate prepared in Examples and Comparative Examples was used.

LCD module

The light source-side polarizing plate was adhered to the lower surface of the liquid crystal panel, and the viewer-side polarizing plate was adhered to the upper surface of the liquid crystal panel. At this time, the antireflection layer of the viewing-side polarizing plate was positioned at the outermost part from the upper surface of the liquid crystal panel. A module for a liquid crystal display device was manufactured by disposing a backlight unit under the light source-side polarizing plate.

Using EZCONTRAST X88RC (EZXL-176R-F422A4, ELDIM) in white mode and black mode, from the front (0°) to the right side (90°) and left side (-90°) in spherical coordinate system ) The luminance values were measured.

(Luminance value in white mode from the front in Examples and Comparative Example) / (Luminance value in white mode from the front for Comparative Example 1) x 100 was calculated as relative luminance.

(Ratio of luminance value of white mode to luminance value of black mode at 60° side in Examples and Comparative Examples) / (Luminance of white mode to luminance value of black mode at 60° side for Comparative Example 1) Ratio of values) x 100 was calculated as the relative side contrast ratio.

Relative luminance*Relative side contrast ratio can be obtained by multiplying the obtained relative luminance and the relative side contrast ratio.

The white turbidity was evaluated with the naked eye after the viewer-side polarizing plate was attached to the upper surface of the liquid crystal panel, and then in the power off state (black). 1 is weak, 5 is strong, and it was judged that it was usable at the 1-2 level.

Example comparative example One 2 3 4 5 6 7 One 2 3 4 5 1st resin layer wire wire wire wire wire wire wire - wire wire - road Content in the first resin layer
(weight%) 4.9 4.9 9.8 9.8 9.8 4.9 9.8 - 4.9 9.8 - 9.8 Orientation angle (θ, °) 0 90 0 20 70 0 0 - 30 60 - 0 Haze (%) 17 17 32 32 32 41 52 - 17 32 31 39 ΔD (μm) 80 80 80 80 80 80 80 - 80 80 - 80 Relative Luminance (%) 95 95 92 92 92 82 80 100 95 95 83 81 Relative side contrast ratio (%) 115 116 124 118 117 136 144 100 103 102 121 106 Relative Luminance * Relative Side Contrast Ratio 1.09 1.10 1.14 1.09 1.08 1.11 1.15 1.00 0.98 0.97 1.00 0.85 cloudy One One 2 2 2 2 2 One 2 3 2 4

As shown in Table 2, the polarizer according to the embodiment of the present invention can increase the value of relative luminance*relative side contrast ratio to 1.05 or more, and thus minimize frontal luminance loss while improving side visibility. In addition, it is possible to provide a polarizing plate having low cloudiness, thereby improving the appearance of the liquid crystal display. In particular, since the pattern manufacturing process is omitted in the polarizing plates of Examples 1 to 5, fairness and economy of the polarizing plate can be improved.

On the other hand, Comparative Example 1 not employing the polarizing plate of this embodiment had high relative luminance but low side visibility. In addition, Comparative Examples 2 to 4 not employing the polarizing plate of this embodiment had a low relative luminance*relative side contrast ratio. In addition, Comparative Example 5 in which the polarizing plate of this Example was not employed had a low relative luminance*relative side contrast ratio, and poor appearance due to high cloudiness.

Simple modifications or changes of the present invention can be easily performed by those skilled in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (22)

polarizer; And a first resin layer laminated on at least one surface of the polarizer, wherein the first resin layer includes at least one of a wire and a fiber,
At least a portion of one or more of the wires and fibers is oriented and aligned at an orientation angle θ with respect to the direction of the light absorption axis of the polarizer,
The orientation angle (θ) is 65 ° to 115 ° or 0 ° to 25 ° with respect to the direction of the light absorption axis of the polarizer, the polarizing plate.
The polarizing plate according to claim 1, wherein the first resin layer is a contrast ratio and/or visibility improving layer.
The polarizing plate according to claim 1, wherein 60% by weight or more of the wires and fibers in the first resin layer are aligned at the orientation angle (θ) with respect to the light absorption axis of the polarizer.
The polarizing plate according to claim 1, wherein 80% by weight or more of the wires and fibers are independently dispersed in the first resin layer.
The polarizing plate of claim 1, wherein the first resin layer has a distance (ΔD) from the polarizer of 0 μm to 200 μm.
The polarizing plate of claim 1, wherein the first resin layer has a refractive index of 1.40 to 1.80.
The polarizing plate according to claim 1, wherein the wire or the fiber has an aspect ratio of 500 or less.
The polarizing plate of claim 1, wherein at least one of the wires and fibers is included in an amount of 1% to 40% by weight in the first resin layer.
The polarizing plate of claim 1 , wherein the first resin layer further comprises a matrix impregnated with at least one of the wires and fibers, and wherein at least one of the wires and fibers has a high refractive index compared to the matrix.
The polarizing plate of claim 1, wherein the first resin layer has a haze of 40% or less.
The method of claim 1, wherein at least one of the wires and fibers is formed of at least one of metal, nonmetal, metal oxide, nonmetal oxide, metal sulfide, nonmetal sulfide, metal nitride, nonmetal nitride, metal hydroxide, nonmetal hydroxide, and glass. that is, a polarizer.
The polarizing plate according to claim 11, wherein at least one of the wires and fibers is formed of zinc oxide.
The polarizing plate of claim 1 , wherein the polarizing plate includes the polarizer and the first resin layer and the first protective layer sequentially stacked on the light exit surface of the polarizer.
14. The polarizing plate of claim 13, wherein the light exit surface of the first resin layer is generally flat.
The method of claim 14, wherein the first resin layer and the first protective layer are formed in direct contact,
Wherein the laminate of the first resin layer and the first protective layer has a haze of 60% or less, a polarizing plate.
14. The polarizing plate of claim 13, further comprising a second resin layer laminated on one surface or the other surface of the first resin layer.
The polarizing plate of claim 16 , wherein a pattern portion is formed at an interface between the first resin layer and the second resin layer.
The polarizing plate of claim 17 , wherein the pattern part includes an embossed optical pattern and a separation surface formed immediately adjacent to the embossed optical pattern.
The polarizing plate of claim 17 , wherein the embossed optical pattern includes a flat surface, a curved surface, or an angled surface.
The polarizing plate of claim 17 , wherein the second resin layer has a higher refractive index than that of the first resin layer.
The polarizing plate of claim 16, wherein the laminate of the first resin layer, the second resin layer, and the first protective layer has a haze of 60% or less.
An optical display device comprising the polarizing plate of any one of claims 1 to 21.

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