KR20210127038A - Polarizing plate and optical display apparatus comprising the same - Google Patents

Abstract

Provided are a polarizing plate and an optical display apparatus comprising the same. The polarizing plate comprises: a polarizer; and a laminate formed on one surface of the polarizer, and having three or more retardation layers. The laminate of the retardation layers includes: a core layer; and a first skin layer and a second skin layer formed on one surface and the other surface of the core layer, respectively. The core layer, the first skin layer, and the second skin layer satisfy either of the following condition (i) that the in-plane retardation at a wavelength of 550 nm of the core layer is 180 to 260 nm, and the sum of the in-plane retardations of the first skin layer and the second skin layer at a wavelength of 550 nm is 70 to 140 nm the following condition (ii) that the in-plane retardation at a wavelength of 550 nm of the core layer is 70 to 140 nm, and the sum of the in-plane retardations of the first skin layer and the second skin layer at a wavelength of 550 nm is 180 to 260 nm. The angle α formed by the slow axis of the core layer with respect to the absorption axis of the polarizer is -45 to +45 degrees, and the angles β formed by the slow axis of the first skin layer and the second skin layer with respect to the absorption axis of the polarizer satisfy an equation 1. Therefore, the polarizing plate can increase anti-reflection performance on the front and side surfaces thereof.

Description

Polarizing plate and optical display device including same

The present invention relates to a polarizing plate and an optical display device including the same. More particularly, the present invention relates to a polarizing plate having improved anti-reflection performance from the front and side, and improved manufacturing processability of the polarizing plate because there is no appearance defect, winding defect, etc., and an optical display device including the same.

The organic light emitting diode display has a problem in that visibility and contrast are deteriorated due to reflection of external light. A polarizing plate including a polarizer and a retardation film may solve the above problem by implementing an anti-reflection function to prevent reflected external light from leaking out.

A polarizing plate may be manufactured by bonding two 1/2 retardation layers and a 1/4 retardation layer to a polarizer in general. However, the angle (eg, 15°) between the 1/2 retardation layer and the absorption axis of the polarizer is different from the angle (eg, 75°) between the 1/4 retardation layer and the absorption axis of the polarizer. Therefore, when the polarizer, the 1/2 retardation layer, and the 1/4 retardation layer are laminated and then cut to manufacture a polarizing plate, the 1/2 retardation layer and/or the 1/4 retardation layer may be wasted, so that the manufacturing processability of the polarizing plate is improved. There is a problem in that economic efficiency is reduced.

In addition, the 1/2 phase difference layer and the 1/4 phase difference layer are generally formed of different materials, respectively. However, some of the materials forming the retardation layer may have problems such as sticking to the winding roll during winding, making it impossible to wind, and thus there may be a problem in that a protective film needs to be additionally attached to the retardation layer laminate. Such a protective film has a pattern or the like formed on the surface of the protective film to facilitate release or winding. Such a pattern may be transferred to the retardation layer laminate as it is, thereby deteriorating the function of the retardation layer laminated body or making the appearance of the retardation layer laminated body poor.

Background art of the present invention is disclosed in Korean Patent Publication No. 10-2013-0103595 and the like.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polarizing plate having improved antireflection performance in front and side surfaces.

Another object of the present invention is to provide a polarizing plate having excellent manufacturing processability and economic feasibility because there is no appearance defect, inability to wind, and the like.

One aspect of the present invention is a polarizing plate.

1. The polarizer is a polarizer; and a laminate of retardation layers formed on one surface of the polarizer and having three or more retardation layers, wherein the laminate of the retardation layers is a core layer, and a first skin layer formed on one surface and the other surface of the core layer, respectively. , a second skin layer, wherein the core layer, the first skin layer, and the second skin layer satisfy the following (i) or (ii),

(i) the in-plane retardation (Re) of the core layer at a wavelength of 550 nm is 180 nm to 260 nm, and the sum of the in-plane retardation at a wavelength of 550 nm of the first skin layer and the second skin layer is 70 nm to 140 nm;

(ii) the in-plane retardation of the core layer at a wavelength of 550 nm is 70 nm to 140 nm, and the sum of the in-plane retardation of the first skin layer and the second skin layer at a wavelength of 550 nm is 180 nm to 260 nm;

An angle α formed by a slow axis of the core layer with respect to the absorption axis of the polarizer is -45° to +45°, and the first skin layer and the second skin layer are formed with respect to the absorption axis of the polarizer. Each of the angles β formed by the slow axis satisfies Equation 1 below:

[Equation 1]

85° ≤ ｜ angle α - angle β｜ ≤ 95°,

(In Equation 1, the angle α is not 0°).

2. In 1, the angle β may be -45° to +45°.

In 3.1-2, any one of the core layer and the first skin layer may have flat wavelength dispersion, and the other one may have normal wavelength dispersion.

In 4.1-3, any one of the core layer and the second skin layer may have flat wavelength dispersion, and the other one may have normal wavelength dispersion.

In 5.1, the core layer, the first skin layer, and the second skin layer may satisfy (i) above.

In 6.5, the thickness direction retardation of the core layer at a wavelength of 550 nm may be 150 nm to 180 nm.

In 7.5-6, the core layer may have a degree of biaxiality of 1.0 or more at a wavelength of 550 nm.

In 8.5-7, the first skin layer and the second skin layer may each have an in-plane retardation of 20 nm to 70 nm at a wavelength of 550 nm.

In 9.5-8, the thickness direction retardation of each of the first skin layer and the second skin layer at a wavelength of 550 nm may be -60 nm to -30 nm.

In 10.5-9, each of the first skin layer and the second skin layer may have a degree of biaxiality of 0 or less at a wavelength of 550 nm.

In 11.5-10, the core layer may include a cyclic polyolefin (COP)-based resin, and the first skin layer and the second skin layer may include a polycarbonate-based or modified polycarbonate-based resin, respectively.

In 12.1-4, the core layer, the first skin layer, and the second skin layer may satisfy (ii) above.

In 13.12, the thickness direction retardation of the core layer at a wavelength of 550 nm may be -100 nm to -30 nm.

In 14.12-13, the core layer may have a degree of biaxiality of 0 or less at a wavelength of 550 nm.

In 15.12-14, the first skin layer and the second skin layer may each have an in-plane retardation of 90 nm to 150 nm at a wavelength of 550 nm.

In 16.12-15, the thickness direction retardation of each of the first skin layer and the second skin layer at a wavelength of 550 nm may be 50 nm to 100 nm.

In 17.12-16, each of the first skin layer and the second skin layer may have a degree of biaxiality of 1.0 or more at a wavelength of 550 nm.

In 18.12-17, the core layer may include a polycarbonate-based or modified polycarbonate-based resin, and the first skin layer and the second skin layer may include a cyclic polyolefin (COP)-based resin, respectively.

In 19.1-18, a protective film may be further formed on the other surface of the polarizer.

One 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 with improved antireflection performance on the front and side surfaces.

The present invention provides a polarizing plate having excellent manufacturing processability and economic feasibility because there is no appearance defect, winding inability, and the like.

1 is a cross-sectional view of a polarizing plate according to an embodiment of the present invention.
FIG. 2 shows an arrangement relationship among the absorption axis of the polarizer, the slow axis of the core layer, the slow axis of the first skin layer, and the slow axis of the second skin layer in the polarizing plate of FIG. 1 .
3 is a cross-sectional view of a polarizing plate according to another embodiment of the present invention.
FIG. 4 shows the arrangement relationship among the absorption axis of the polarizer, the slow axis of the core layer, the slow axis of the first skin layer, and the slow axis of the second skin layer in the polarizing plate of FIG. 3 .
5 is a reflection evaluation result of Example 1 (left) and Comparative Example 6 (right) respectively.

With reference to the accompanying drawings, the present invention will be described in detail so as to be easily practiced by those of ordinary skill in the art to which the present invention pertains by way of example. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and the same names are used for the same or similar components throughout the specification. The length and size of each component in the drawings are for explaining the present invention, and the present invention is not limited to the length and size of each component described in the drawings.

In this specification, "upper" and "lower" are defined based on the drawings, and "upper" may be changed to "lower" and "lower" to "upper" depending on the viewing angle.

In the present specification, the "in-plane retardation (Re)" is represented by the following formula A, the "thickness direction retardation (Rth)" is represented by the following formula B, and "the degree of biaxiality (NZ)" can be represented by the following formula C have:

[Formula A]

Re = (nx - ny) x d

[Formula B]

Rth = ((nx + ny)/2 - nz) x d

[Formula C]

NZ = (nx - nz)/(nx - ny)

(In Equations A to C, nx, ny, and nz are refractive indices in the slow axis direction, fast axis direction, and thickness direction of the optical element, respectively, at the measurement wavelength, and d is the thickness of the optical element. (unit: nm)). In Equations A to C, the measurement wavelength may be 450 nm, 550 nm or 650 nm.

In the present specification, "short wavelength dispersion" is Re(450)/Re(550), and "long wavelength dispersion" is Re(650)/Re(550). Re(450), Re(550), and Re(650) mean in-plane retardation (Re) at wavelengths of 450 nm, 550 nm, and 650 nm of the optical element, respectively.

When describing an angle in this specification, "+" means a clockwise direction with respect to the reference, and "-" means a counterclockwise direction with respect to the reference.

As used herein, “(meth)acryl” may mean acryl and/or methacrylic.

In the present specification, "front" and "side" are, respectively, based on the horizontal direction, when (φ, θ) by a spherical coordinate system, the front is (0°, 0°), and the left end When the point is (180°, 90°) and the right end point is (0°, 90°), the side means (0°, 30°) to (0°, 60°).

As used herein, the term “reflectance” refers to a value measured in a visible light region (eg, a wavelength of 380 nm to 780 nm).

In the present specification, "X to Y" when referring to a numerical range means "X or more and Y or less (X≤ and ≤Y)".

The inventor of the present invention remarkably improves the anti-reflection performance on the front and side surfaces of the polarizing plate, and provides a polarizing plate with improved manufacturing processability of the polarizing plate by solving problems such as poor appearance and poor winding when manufacturing a laminate of retardation layers did. The polarizing plate of the present invention may be used as an anti-reflection polarizing plate in a light emitting display device including an organic light emitting (OLED) display device.

The polarizing plate of the present invention includes a laminate of a polarizer and a retardation layer formed on one surface of the polarizer. The laminate of the retardation layer is a laminate of three or more retardation layers. The laminate of the retardation layer includes a core layer, a first skin layer and a second skin layer respectively formed on one surface and the other surface of the core layer. The core layer, the first skin layer, and the second skin layer satisfy the following (i) or (ii):

(i) the in-plane retardation at a wavelength of 550 nm of the core layer is 180 nm to 260 nm, and the sum of the in-plane retardation of the first skin layer and the second skin layer at a wavelength of 550 nm is 70 nm to 140 nm;

(ii) the in-plane retardation at a wavelength of 550 nm of the core layer is 70 nm to 140 nm, and the sum of the in-plane retardation of the first skin layer and the second skin layer at a wavelength of 550 nm is 180 nm to 260 nm.

The angle α formed by the slow axis of the core layer with respect to the absorption axis of the polarizer is -45° to +45°, and the slow axis of the first skin layer and the slow axis of the second skin layer with respect to the absorption axis of the polarizer. Each of the angles β formed by the axis satisfies Equation 1 below:

[Equation 1]

85° ≤ ｜ angle α - angle β｜ ≤ 95°,

(In Equation 1, the angle α is not 0°).

Hereinafter, each configuration of the polarizing plate of the present invention will be described in detail.

polarizer

The polarizer may convert incident natural light or polarized light into linearly polarized light in a specific direction, thereby lowering reflectance at the front and side surfaces of the polarizing plate. The polarizer may be manufactured from a polymer film containing a polyvinyl alcohol-based resin as a main component. For example, the polarizer may be manufactured by dyeing the polymer film with iodine or a dichroic dye and stretching it in the machine direction (MD). The absorption axis of the polarizer may be substantially the same as the MD of the polarizer, which is the stretching direction of the polyvinyl alcohol-based film when the polarizer is manufactured.

The polarizer may be manufactured through swelling, dyeing, stretching, crosslinking, and optionally complementary color processes. The swelling, dyeing, stretching, and crosslinking may be performed by conventional methods known to those skilled in the art.

The polarizer may have a total light transmittance of 40% or more, for example, 40% to 47%, and a polarization degree of 99% or more, for example, 99% to 100%. Within the above range, it is possible to improve the antireflection performance when combined with the core layer, the first skin layer, and the second skin layer.

The polarizer may have a thickness of 2 μm to 30 μm, specifically 4 μm to 25 μm, and may be used in the polarizing plate in the above range.

Laminate of retardation layer

The laminate of the retardation layer is formed on the lower surface of the polarizer. Here, the lower surface of the polarizer is a surface opposite to the upper surface of the polarizer to which external light is incident.

The retardation layer laminate includes three or more retardation layers, and includes a core layer, a first skin layer stacked on one surface of the core layer, and a second skin layer stacked on the other surface of the core layer.

In one embodiment, the laminate of the retardation layer may include a core layer having relatively poor physical properties as a film material compared to the first skin layer and the second skin layer in the polarizing plate, thereby improving manufacturing processability of the polarizing plate. That is, the core layer may have problems such as sticking to the winding roll, making it impossible to wind, or may have a problem of poor appearance due to pattern transfer of the protective film that must be added during winding due to the above problem. However, the stacked body of the retardation layer of the present invention can solve the above problems by including the first skin layer and the second skin layer on one surface and the other surface of the core layer, respectively.

Meanwhile, the core layer, the first skin layer, and the second skin layer satisfy the following (i) or (ii):

(i) the in-plane retardation of the core layer at a wavelength of 550 nm is 180 nm to 260 nm, and the sum of the in-plane retardation of the first skin layer and the second skin layer at a wavelength of 550 nm is 70 nm to 140 nm;

(ii) the in-plane retardation of the core layer at a wavelength of 550 nm is 70 nm to 140 nm, and the sum of the in-plane retardation of the first skin layer and the second skin layer at a wavelength of 550 nm is 180 nm to 260 nm.

In the laminate of the retardation layer of the present invention, the in-plane retardation at a wavelength of 550 nm of the entire first skin layer, the second skin layer, and the core layer was adjusted to be any one of 180 nm to 260 nm, 70 nm to 140 nm, and the other one. In addition, in the polarizing plate, the slow axes of the core layer, the first skin layer, and the second skin layer with respect to the absorption axis of the polarizer satisfy the above-described angular relationship. Through this, the polarizing plate can significantly lower the reflectance at the front and the side.

The above (i) and (ii) will be described sequentially. First, the case of (i) will be described.

In case (i)

In the laminate of the retardation layer, the in-plane retardation at a wavelength of 550 nm of the core layer is 180 nm to 260 nm, and the sum of the in-plane retardation at a wavelength of 550 nm of the first skin layer and the in-plane retardation at a wavelength of 550 nm of the second skin layer is 70 nm to 140 nm .

Referring to FIG. 1 , the polarizing plate includes a polarizer 100 , a core layer 110A, a first skin layer 120A, a second skin layer 130A, and a protective film 140 .

The polarizer 100 is the same as described above.

The laminate of the retardation layer is laminated on the lower surface of the polarizer 100 , and the core layer 110A, the first skin layer 120A laminated on the upper surface of the core layer 110A, and the lower surface of the core layer 110A. and a second skin layer 130A stacked thereon.

The in-plane retardation at a wavelength of 550 nm of the core layer 110A is 180 nm to 260 nm. In the above range, it may help to lower the reflectance at the front and the side when the phase difference laminate of three or more layers is used. Preferably, the in-plane retardation at a wavelength of 550 nm of the core layer 110A may be 200 nm to 260 nm.

The core layer 110A may have a short wavelength dispersion of 0.95 to 1.2, specifically 1.0 to 1.1, and more specifically 1 to 1.05. The core layer 110A may have a long wavelength dispersion of 0.95 to 1.2, specifically 1.0 to 1.1, and more specifically 1 to 1.05. In the above range, the antireflection performance at the side can be further improved.

Preferably, the core layer 110A may have flat wavelength dispersion (short wavelength dispersion: 1, long wavelength dispersion: 1). When the core layer 110A has flat wavelength dispersion, the effect of the present invention may be easily realized.

The thickness direction retardation of the core layer 110A may be 150 nm to 180 nm, specifically 150 nm to 170 nm, as a positive (+) value at a wavelength of 550 nm. In the above range, the antireflection performance at the side can be further improved.

The core layer 110A may have a degree of biaxiality of 1.0 or more at a wavelength of 550 nm, specifically 1.0 to 1.5, and more specifically 1.0 to 1.3. In the above range, the antireflection performance at the side can be further improved.

The core layer 110A is nx ≒ nz > ny or nx > ny ≒ nz (in this case, nx, ny, and nz are the refractive indexes of the slow axis, fast axis, and thickness direction of the core layer 110A at a wavelength of 550 nm, respectively). It can be a negative A plate or a positive A plate with a relationship. Since the core layer 110A satisfies the above refractive index relationship, it can help improve antireflection performance due to the laminate of the core layer 110A, the first skin layer 120A, and the second skin layer 130A of the present invention. . In one embodiment, in the core layer 110A, nx may be 1.40 to 1.70, ny may be 1.40 to 1.70, and nz may be 1.40 to 1.70.

The core layer 110A may have a thickness of 5 μm to 70 μm, specifically 15 μm to 50 μm, and may be used for a polarizing plate within the above range.

The core layer 110A may include a non-liquid crystalline resin. In one embodiment, the core layer 110A is a poly containing cellulose-based, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate (PET), polybutylene naphthalate, etc. including triacetyl cellulose (TAC). Ester, cyclic polyolefin (COP), polycarbonate, polyethersulfone, polysulfone, polyamide, polyimide, polyolefin, polyarylate, polyvinyl alcohol, polyvinyl chloride, poly It may be formed of one or more kinds of vinylidene chloride-based resins. Preferably, the core layer 110A may be formed of a cyclic polyolefin (COP)-based resin.

Specifically, the core layer 110A may be formed of a resin having positive (+) birefringence. When a resin having positive (+) birefringence is used as a first skin layer and a second skin layer described in detail below, a resin having negative (-) birefringence is used and a laminate of the retardation layer is manufactured by co-extrusion. The manufacture of the laminated body of the retardation layer of this invention can be made easy only by one extending|stretching. For example, the core layer 110A may be formed of a cyclic polyolefin (COP)-based resin.

If the core layer 110A has the above-described retardation, there is no particular limitation on the manufacturing method. In one embodiment, the core layer 110A may be manufactured by uniaxially or biaxially stretching MD, TD. In another embodiment, the core layer 110A may be manufactured by oblique stretching.

Preferably, as the core layer 110A, it may be produced by oblique stretching in a direction of +45° to -45° with respect to the MD of the unstretched sheet or film for the core layer 110A. When the core layer 110A is obliquely stretched, when the core layer 110A, the first skin layer 120A, and the second skin layer 130A, which will be described in detail below, are co-extruded, the core layer 110A, the first The in-plane retardation of each of the skin layer 120A and the second skin layer 130A and the angle between the absorption axis and the slow axis may be easily adjusted. The MD of the core layer 110A of the polarizing plate is in substantially the same direction as the absorption axis of the polarizer. When manufactured by co-extrusion, the first skin layer 120A and the second skin layer 130A are directly formed on the core layer 110A, respectively.

The first skin layer 120A and the second skin layer 130A are respectively formed on one surface and the other surface of the core layer 110A to protect the core layer 110A.

The sum of the in-plane retardation at a wavelength of 550 nm of the first skin layer 120A and the in-plane retardation at a wavelength of 550 nm of the second skin layer 130A is 70 nm to 140 nm. In the above range, it may help to lower the reflectance at the front and the side when the phase difference laminate of three or more layers is used. Preferably, the total sum of the in-plane retardation may be 90 nm to 130 nm.

The first skin layer 120A may have substantially the same or different in-plane retardation at a wavelength of 550 nm compared to the second skin layer 130A. Preferably, the first skin layer 120A and the second skin layer 130A are manufactured by co-extrusion, so that the in-plane retardation is the same at a wavelength of 550 nm, thereby improving the manufacturing processability of the laminate of the retardation layer.

In one embodiment, the in-plane retardation of the first skin layer 120A at a wavelength of 550 nm may be 20 nm to 70 nm, specifically, 35 nm to 70 nm. In the above range, the 70 nm to 140 nm can be easily reached, and the effect of the present invention can be well realized.

In one embodiment, the in-plane retardation of the second skin layer 130A at a wavelength of 550 nm may be 20 nm to 70 nm, specifically 35 nm to 70 nm. In the above range, the 70 nm to 140 nm can be easily reached, and the effect of the present invention can be well realized.

Each of the first skin layer 120A and the second skin layer 130A may have a normal wavelength dispersion property. Through this, in the polarizing plate of the present invention, the anti-reflection performance from the front and the side can be further improved, the material can be easily obtained when the first skin layer and the second skin layer are formed, and the manufacturing processability and economic efficiency can be excellent.

The first skin layer 120A and the second skin layer 130A may have a short wavelength dispersion of 0.95 to 1.2, specifically 1.1 to 1.2, and more specifically 1.15 to 1.2, respectively. In the above range, the antireflection performance at the side can be further improved.

The first skin layer 120A and the second skin layer 130A may have a long wavelength dispersion of 0.8 to 1, specifically 0.8 to 0.95, and more specifically 0.8 to 0.92. In the above range, the antireflection performance at the side can be further improved.

The thickness direction retardation of the first skin layer 120A and the second skin layer 130A at a wavelength of 550 nm is a negative (-) value, and may be -60 nm to -30 nm, specifically -55 nm to -30 nm. In the above range, the antireflection performance at the side can be further improved.

Each of the first skin layer 120A and the second skin layer 130A may have a degree of biaxiality of 0 or less, specifically -1.0 to 0, and more specifically -0.5 to 0 at a wavelength of 550 nm. In the above range, the antireflection performance at the side can be further improved. Preferably, the degree of biaxiality may be a negative (-) value.

The first skin layer 120A and the second skin layer 130A each have nx = nz > ny or nx > ny = nz (in this case, nx, ny, and nz are each at a wavelength of 550 nm). The two skin layers 130A may have a relationship between the refractive index of each of the slow axis direction, the fast axis direction, and the thickness direction). Since the first skin layer 120A and the second skin layer 130A satisfy the above refractive index relationship, the laminate of the core layer 110A, the first skin layer 120A, and the second skin layer 130A of the present invention is caused by It can help to improve anti-reflection performance. In one embodiment, the first skin layer 120A and the second skin layer 130A may have nx of 1.40 to 1.60, ny of 1.40 to 1.60, and nz of 1.40 to 1.60, respectively.

The first skin layer 120A and the second skin layer 130A may have a thickness of 0.1 μm to 70 μm, specifically 1 μm to 30 μm, and more specifically 1 μm to 20 μm, and in the above range, Can be used.

The thickness of the core layer 110A: the thickness ratio by the thickness of the first skin layer 120A or the thickness of the second skin layer 120A is 1:0.01 to 1:1, preferably 1:0.1 to 1:0.6 this can be In the above range, the strength of the laminate of the retardation layer may be excellent.

The material of the first skin layer 120A and the second skin layer 130A is not particularly limited as long as the above-described phase difference can be realized.

In one embodiment, the first skin layer 120A and the second skin layer 130A may include a film formed of the non-crystalline resin described above in the core layer.

In another embodiment, the first skin layer 120A and the second skin layer 130A may include a coating layer formed of a liquid crystal composition. In this case, the first skin layer 120A and the second skin layer 130A may be prepared by coating the liquid crystal composition on both surfaces of the core layer 110A to form a coating layer and then stretching.

In another embodiment, the first skin layer 120A and the second skin layer 130A may include a coating layer formed of a non-crystalline composition. In this case, the first skin layer 120A and the second skin layer 130A may be prepared by coating the non-liquid crystal composition on both surfaces of the core layer 110A to form a coating layer and then stretching. The non-liquid crystalline composition is a polycarbonate-based, cellulose acetate, cellulose ester-based composition including cellulose butyrate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and the like polyester-based, ring One type of polyolefin, polycarbonate, polyethersulfone, polysulfone, polyamide, polyimide, polyolefin, polyarylate, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride may include more than one.

Specifically, each of the first skin layer 120A and the second skin layer 130A may be formed of a resin having negative (-) birefringence. The resin having negative birefringence uses a resin having positive birefringence as the core layer 110A, and when manufacturing the laminate of the retardation layer by co-extrusion, the manufacture of the laminate of the retardation layer of the present invention is performed only by one stretching. can be done easily For example, each of the first skin layer 120A and the second skin layer 130A may be formed of a polycarbonate-based resin.

Specifically, each of the first skin layer 120A and the second skin layer 130A may be formed of a material having a retardation expression rate greater than 5 nm/㎛. In the above range, there may be an anti-reflection effect. The "phase difference expression rate" means a phase difference value according to thickness.

Preferably, the non-crystalline composition may include at least one of a modified polycarbonate-based resin, a modified polycarbonate-based oligomer, and a modified polycarbonate-based monomer. The modified polycarbonate system can further enhance the antireflection effect in the polarizing plate of the present invention.

The thickness of the laminate of the retardation layer may be 2 μm to 100 μm, specifically 40 μm to 90 μm. Within the above range, it can be applied to a polarizing plate.

Referring to FIG. 2 , the angle α formed by the slow axis 110a of the core layer 110A with respect to the absorption axis 100a of the polarizer 100 is -45° to +45°. An angle β formed by the slow axis 120a of the first skin layer 120A with respect to the absorption axis 100a of the polarizer 100 and an angle β formed by the slow axis 130a of the second skin layer 130A ) satisfies Equation 1 below:

[Equation 1]

85° ≤ ｜ angle α - angle β｜ ≤ 95°,

(In Equation 1, the angle α is not 0°).

In this way, the polarizer can help to lower the reflectance in the front and side.

2 shows the angle β formed by the slow axis 120a of the first skin layer 120A with respect to the absorption axis 100a of the polarizer 100 and the absorption axis 100a of the polarizer 100. The angle β formed by the slow axis 130a of the two skin layers 130A is the same as each other. However, in the polarizing plate of the present invention, these two angles may be different from each other.

In one embodiment, the angle (α) may be -45 ° to -40 °, +40 ° to +45 °.

In one embodiment, the angle β may be -45° to +45°, for example, -45° to -40°, +40° to +45°.

In one embodiment, the |angle α - angle β| can be 86°, 87°, 88°, 90°, 91°, 92°, 93° or 94°, preferably 90°.

The protective film 140 may be further formed on the other side of the polarizer 100 , ie, the upper surface of the polarizer, to protect the polarizer from the external environment or provide additional functions such as improvement of mechanical strength of the polarizer.

The protective film 140 is an optically transparent film, and is made of, for example, cellulose-based, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate (PET), polybutylene naphthalate, etc. including triacetyl cellulose (TAC). Including polyester, cyclic polyolefin, polycarbonate, polyethersulfone, polysulfone, polyamide, polyimide, polyolefin, polyarylate, polyvinyl alcohol, polyvinyl chloride, poly It may be a film made of at least one of vinylidene chloride-based resins. Specifically, as the protective film, a TAC film or a PET film may be used.

The protective film 140 may have a thickness of 5 μm to 70 μm, specifically 15 μm to 45 μm, and may be used for a polarizing plate within the above range.

A functional coating layer may be formed on the upper surface of the protective film 140 to provide an additional function to the polarizing plate. For example, the functional coating layer may be a hard coating layer, an anti-fingerprint layer, an anti-reflection layer, and the like, and these may be formed alone or by laminating two or more types.

Although not shown in FIG. 1 , an adhesive layer or an adhesive layer is formed on the lower surface of the second skin layer 130A, so that a polarizing plate may be laminated on the light emitting device panel.

Hereinafter, (ii) is demonstrated.

In case (ii)

The laminate of the retardation layer has an in-plane retardation of 70 nm to 140 nm at a wavelength of 550 nm of the core layer, and the sum of the in-plane retardation at a wavelength of 550 nm of the first skin layer and in-plane retardation at a wavelength of 550 nm of the second skin layer is 180 nm to 260 nm .

Referring to FIG. 3 , the polarizing plate includes a polarizer 100 , a core layer 110B, a first skin layer 120B, a second skin layer 130B, and a protective film 140 .

The polarizer 100 and the protective film 140 are the same as described above.

The in-plane retardation at a wavelength of 550 nm of the core layer 110B is 70 nm to 140 nm. In the above range, it may help to lower the reflectance at the front and the side when the phase difference laminate of three or more layers is used. Preferably, the in-plane retardation at a wavelength of 550 nm of the core layer 110A may be 90 nm to 140 nm.

The core layer 110B may have wavelength dispersion and positive wavelength dispersion. Through this, in the polarizing plate of the present invention, the anti-reflection performance at the front and the side can be further improved, the material can be easily obtained when the core layer is formed, and the manufacturing processability and economic efficiency can be excellent.

The core layer 110B may have a short wavelength dispersion of 0.95 to 1.2, specifically 1.1 to 1.2, and more specifically 1.15 to 1.2. The core layer 110B may have a long wavelength dispersion of 0.8 to 1, specifically 0.8 to 0.95, and more specifically 0.8 to 0.92. In the above range, the antireflection performance at the side can be further improved.

The thickness direction retardation of the core layer 110B at a wavelength of 550 nm is a negative (-) value, and may be -100 nm to -30 nm, specifically -100 nm to -50 nm. In the above range, the antireflection performance at the side can be further improved.

The core layer 110B may have a degree of biaxiality of 0 or less at a wavelength of 550 nm, specifically -1.0 to 0, and more specifically -0.5 to 0. In the above range, the antireflection performance at the side can be further improved. Preferably, the degree of biaxiality may be a negative (-) value.

The core layer 110B has nx = nz > ny or nx > ny = nz (in this case, nx, ny, and nz are the refractive index in the slow axis direction, the fast axis direction, and the thickness direction of the core layer 110B at a wavelength of 550 nm, respectively) can have a relationship. Since the core layer 110B satisfies the above refractive index relationship, it can help to improve antireflection performance due to the laminate of the core layer 110B, the first skin layer 120B, and the second skin layer 130B of the present invention. . In one embodiment, in the core layer 110B, nx may be 1.40 to 1.60, ny may be 1.40 to 1.60, and nz may be 1.40 to 1.60.

The core layer 110B may have a thickness of 5 μm to 70 μm, specifically 15 μm to 45 μm, and may be used for a polarizing plate within the above range.

The material of the core layer 110B is not particularly limited as long as it can implement the above-described retardation.

In one embodiment, the core layer 110B may be formed of the material described above in the first skin layer 120A and the second skin layer 130A of FIG. 1 . For example, the core layer 110B may include at least one of a polycarbonate-based resin, a modified polycarbonate-based resin, a modified polycarbonate-based oligomer, and a modified polycarbonate-based monomer. The modified polycarbonate system can further enhance the antireflection effect in the polarizing plate of the present invention.

The first skin layer 120B and the second skin layer 130B are respectively formed on one surface and the other surface of the core layer 110B to protect the core layer 110B.

The sum of the in-plane retardation at a wavelength of 550 nm of the first skin layer 120B and the in-plane retardation at a wavelength of 550 nm of the second skin layer 130B is 180 nm to 260 nm. In the above range, it may help to lower the reflectance at the front and the side when the phase difference laminate of three or more layers is used. Preferably, the total sum of the in-plane retardation may be 200 nm to 260 nm.

The first skin layer 120B may have the same or different in-plane retardation at a wavelength of 550 nm compared to the second skin layer 130B. Preferably, since the first skin layer 120B and the second skin layer 130B are manufactured by co-extrusion, the in-plane retardation is the same at a wavelength of 550 nm, thereby improving the manufacturing processability of the laminate of the retardation layers.

In one embodiment, the in-plane retardation of the first skin layer 120B at a wavelength of 550 nm may be 90 nm to 150 nm, specifically, 90 nm to 130 nm. In the above range, the 180 nm to 260 nm can be easily reached, and the effect of the present invention can be well realized.

In one embodiment, the in-plane retardation of the second skin layer 130B at a wavelength of 550 nm may be 90 nm to 150 nm, specifically, 90 nm to 130 nm. In the above range, the 180 nm to 260 nm can be easily reached, and the effect of the present invention can be well realized.

Each of the first skin layer 120B and the second skin layer 130B may have flat wavelength dispersion (short wavelength dispersion: 1, long wavelength dispersion: 1). Through this, in the polarizing plate of the present invention, the anti-reflection performance from the front and the side can be further improved, the material can be easily obtained when the first skin layer and the second skin layer are formed, and the manufacturing processability and economic efficiency can be excellent.

The thickness direction retardation of the first skin layer 120B and the second skin layer 130B at a wavelength of 550 nm is a positive (+) value, and may be 50 nm to 100 nm, specifically 50 nm to 90 nm. In the above range, the antireflection performance at the side can be further improved.

Each of the first skin layer 120B and the second skin layer 130B may have a degree of biaxiality of 1.0 or more at a wavelength of 550 nm, specifically 1.0 to 1.5, and more specifically 1.0 to 1.3. In the above range, the antireflection performance at the side can be further improved.

The first skin layer 120B and the second skin layer 130B each have nx ≒ nz > ny or nx > ny ≒ nz (in this case, nx, ny, and nz are each at a wavelength of 550 nm. 2) of the skin layer 130B in the slow axis direction, the fast axis direction, and the refractive index in the thickness direction). Since the first skin layer 120B and the second skin layer 130B satisfy the above refractive index relationship, the laminate of the core layer 110B, the first skin layer 120B, and the second skin layer 130B of the present invention is caused by It can help improve anti-reflection performance. In one embodiment, the first skin layer 120B and the second skin layer 130B may have nx of 1.40 to 1.70, ny of 1.40 to 1.70, and nz of 1.40 to 1.70, respectively.

The first skin layer 120B and the second skin layer 130B may have a thickness of 0.1 μm to 70 μm, specifically 1 μm to 30 μm, and more specifically 1 μm to 25 μm, and in the above range, the polarizing plate Can be used.

The thickness of the core layer 110B: the thickness ratio by the thickness of the first skin layer 120B or the thickness of the second skin layer 120B is 1:0.01 to 1:1, preferably 1:0.1 to 1:0.6 this can be In the above range, the strength of the laminate of the retardation layer may be excellent.

The material of the first skin layer 120B and the second skin layer 130B is not particularly limited as long as the above-described phase difference can be realized.

In one embodiment, each of the first skin layer 120B and the second skin layer 130B may be formed of the material described above in the core layer 110A of FIG. 1 . For example, each of the first skin layer 120B and the second skin layer 130B may include a cyclic polyolefin-based resin. Polycarbonate-based or modified polycarbonate-based, preferably modified polycarbonate-based, may further enhance the anti-reflection effect in the polarizing plate of the present invention.

The thickness of the laminate of the retardation layer may be 2 μm to 100 μm, specifically 40 μm to 90 μm. Within the above range, it can be applied to a polarizing plate.

Referring to FIG. 3 , the angle α formed by the slow axis 110b of the core layer 110B with respect to the absorption axis 100a of the polarizer 100 is -45° to +45°. The angle β formed by the slow axis 120b of the first skin layer 120B with respect to the absorption axis 100a of the polarizer 100, and the angle β formed by the slow axis 130b of the second skin layer 130B ) satisfies Equation 1 below:

[Equation 1]

85° ≤ ｜ angle α - angle β｜ ≤ 95°,

(In Equation 1, the angle α is not 0°).

In this way, the polarizer can help to lower the reflectance in the front and side.

3 shows the angle β formed by the slow axis 120b of the first skin layer 120B with respect to the absorption axis 100a of the polarizer 100 and the absorption axis 100a of the polarizer 100. The angle β formed by the slow axis 130b of the second skin layer 130B is the same as each other. However, in the polarizing plate of the present invention, these two angles may be different from each other.

In one embodiment, the angle (α) may be -45 ° to -40 °, +40 ° to +45 °.

In one embodiment, the angle β may be -45° to +45°, for example, -45° to -40°, +40° to +45°.

In one embodiment, the |angle α - angle β| can be 86°, 87°, 88°, 90°, 91°, 92°, 93° or 94°, preferably 90°.

Although not particularly limited, the laminate of the core layer 110B, the first skin layer 120B, and the second skin layer 130B may be manufactured by co-extrusion as described above in FIG. 1 . When manufactured by co-extrusion, the first skin layer 120B and the second skin layer 130B are directly formed on the core layer 110B, respectively.

Although not shown in FIG. 3 , an adhesive layer or an adhesive layer is formed on the lower surface of the second skin layer 130B, so that a polarizing plate may be laminated on the light emitting device panel.

The optical display device of the present invention includes the polarizing plate of the embodiment of the present invention. The optical display device may include an organic light emitting diode (OLED) display device and a liquid crystal display device.

In one embodiment, the organic light emitting diode display device may include an organic light emitting diode panel including a flexible substrate, and the polarizing plate of the present invention laminated on the organic light emitting diode panel.

In another embodiment, the organic light emitting diode display device may include an organic light emitting diode panel including a non-flexible substrate, and the polarizing plate of the present invention laminated on the organic light emitting diode panel.

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this is presented as a preferred example of the present invention and cannot be construed as limiting the present invention in any sense.

Example 1

요오드 수용액에서 6배로 연신하여 광 투과율 45%의 편광자(두께:22㎛) 제조하였다.Polyvinyl alcohol film (PS#60, Kuraray, Japan, thickness before stretching: 60㎛) was applied to 55

A polarizer (thickness: 22 μm) having a light transmittance of 45% was prepared by stretching 6 times in an aqueous iodine solution.

Cyclic polyolefin (COP)-based resin (Zeon, ZEONOR COP, positive birefringence) was used as a material for the core layer.

A modified polycarbonate (PC)-based resin (OGC, OKP, negative birefringence) was used as a material for the first skin layer and the second skin layer, respectively.

By triple co-extrusion of these materials, an unstretched sheet material was prepared, and the prepared unstretched sheet was obliquely stretched at a draw ratio of twice in a 45° oblique direction with respect to the MD of the sheet, whereby the first skin layer (modified PC-based resin, Re 61nm at wavelength 550nm, thickness: 20㎛)-Core layer (COP-based resin, Re 260nm at wavelength 550nm, thickness:46㎛)-Second skin layer (modified PC-based resin, Re 61nm at wavelength 550nm, thickness: 20 μm) to prepare a laminate of the retardation layer of three retardation layers.

A triacetyl cellulose film was adhered to the upper surface of the prepared polarizer as a protective film, and the laminate of the retardation layer prepared above on the lower surface of the prepared polarizer was applied from the polarizer to the first skin layer-core layer-second skin layer. A polarizing plate was prepared by bonding in the order of . At this time, the angle between the slow axis of the core layer, the slow axis of the first skin layer, and the second skin layer with respect to the absorption axis (MD of the polarizer) of the polarizer was adjusted as shown in Table 1 below.

Examples 2 and 5

A polarizing plate was manufactured in the same manner as in Example 1, except that the phase difference, angle α, and angle β of each of the core layer, the first skin layer, and the second skin layer were changed as shown in Table 1 below. did.

Example 3

A polarizer was manufactured in the same manner as in Example 1.

Modified polycarbonate (PC)-based resin (OGC, OKP, negative birefringence) is used as the material for the core layer, and cyclic polyolefin (COP)-based resin (Zeon, ZEONOR COP, positive birefringence) is used for the first and second skin layers. Each was used as a layer material.

By triple co-extrusion of these materials, an unstretched sheet material is prepared, and the prepared unstretched sheet is obliquely stretched at a draw ratio of 3 times in a 45° oblique direction with respect to the MD of the sheet, whereby the first skin layer (COP-based resin, wavelength Re 130 nm at 550 nm, thickness: 23 μm)-Core layer (modified PC-based resin, Re 122 nm at wavelength 550 nm, thickness: 40 μm)-Second skin layer (COP-based resin, Re 130 nm at wavelength 550 nm, thickness: 23 μm) ) to prepare a laminate of the retardation layer of three retardation layers composed of.

A polarizing plate was manufactured by adhering a triacetyl cellulose film to the upper surface of the prepared polarizer as a protective film, and bonding the prepared laminate of the retardation layer to the lower surface of the prepared polarizer. At this time, the angle between the slow axis of the core layer, the slow axis of the first skin layer, and the second skin layer with respect to the absorption axis (MD of the polarizer) of the polarizer was adjusted as shown in Table 1 below.

Example 4

A polarizing plate was manufactured in the same manner as in Example 3 except that the phase difference, angle α, and angle β of each of the core layer, the first skin layer, and the second skin layer were changed as shown in Table 1 below in Example 3 did.

Comparative Example 1

In Example 1, without using a laminate of retardation layers, a retardation layer having an in-plane retardation of 260 nm at a wavelength of 550 nm on the lower surface of the polarizer (made of the modified PC-based resin of Example 1), the in-plane retardation at a wavelength of 550 nm A polarizing plate was manufactured in the same manner as in Example 1, except that a retardation layer having a thickness of 122 nm (made of the COP-based resin of Example 1) was sequentially stacked.

Comparative Examples 2 to 5, Comparative Example 7

In Example 1, a polarizing plate was manufactured in the same manner as in Example 1, except that the core layer, the first skin layer, and the second skin layer were changed as shown in Table 2 below.

Comparative Example 6

In Example 1, without using a laminate of retardation layers, a retardation layer having an in-plane retardation of 260 nm at a wavelength of 550 nm on the lower surface of the polarizer (made of the modified PC-based resin of Example 1), the in-plane retardation at a wavelength of 550 nm A polarizing plate was manufactured in the same manner as in Example 1, except that a 61 nm retardation layer (made of the COP-based resin of Example 1) was sequentially stacked.

The phase difference Re, Rth, NZ, and wavelength dispersion of the core layer, the first skin layer, and the second skin layer were measured using Axoscan (Axometry). Angle α and angle β were measured by Axoscan (Axometry).

Reflectance, appearance, and winding were evaluated using the polarizing plates of Examples and Comparative Examples, and are shown in Tables 1, 2, and 5 below.

(1) Reflectance (unit: %) was measured using a DMS 803 from Japan Instrument Systems (Konica Minolta group). After measuring against the white plate standard provided in DMS 803 of Instrument Systems (Konica Minolta group), luminance and contrast were measured using the Angular Scan function. On the OLED flexible panel (P30 Pro, BOE), the polarizing plates of Examples and Comparative Examples are attached with a pressure-sensitive adhesive, and reflectance values are obtained for the front and side surfaces. Theta was measured in units of 5°, and at a wavelength of 380 nm to 780 nm, spectral transmittance/reflectance (SCE) values were obtained at 0° in front and 60° in the side, and reflectance was measured, respectively.

(2) Appearance and winding: The roughness of the surface of the layered product of the retardation layer wound on the roll was visually checked to determine whether or not the orange peel form was visually recognized. When there is no orange peel type fine press on the surface of the laminate of the retardation layer at all, it was evaluated as good, and when there is even a little orange peel type fine press, it was evaluated as bad.

Example One 2 3 4 5 core layer Re 260 240 122 102 260 Rth 168 155 -90 -74 168 NZ 1.15 1.15 -0.24 -0.23 1.15 short wavelength dispersion One One 1.16 1.16 One long wavelength dispersion One One 0.92 0.92 One 1st skin layer
(2nd skin layer) Re 61 51 130 120 61 Rth -45 -37 84 77.5 -45 NZ -0.24 -0.23 1.15 1.15 -0.24 short wavelength dispersion 1.16 1.16 One One 1.16 long wavelength dispersion 0.92 0.92 One One 0.92 angle α +45 +45 +45 +45 -45 angle β -45 -45 -45 -45 +45 retardation layer 3rd Floor 3rd Floor 3rd Floor 3rd Floor 3rd Floor reflectivity face 0.40 0.47 0.40 0.47 0.40 side 6.28 6.50 6.08 6.33 6.28 Appearance and winding Good Good MI
measurement MI
measurement Good

comparative example One 2 3 4 5 6 7 core layer Re 260 170 280 147 217 260 260 Rth 168 110 180 95 140 168 168 NZ 1.15 1.15 1.14 1.15 1.15 1.15 1.15 short wavelength dispersion One One One One One One One long wavelength dispersion One One One One One One One 1st skin layer
(2nd skin layer) Re 122 33 60 10 33 61 61 Rth -90 -24 -45 -7 -24 -90 -45 NZ -0.24 -0.23 -0.24 -0.22 -0.23 -0.23 -0.24 short wavelength dispersion 1.16 1.16 1.16 1.16 1.16 1.16 1.16 long wavelength dispersion 0.92 0.92 0.92 0.92 0.92 0.92 0.92 angle α +45 +45 +45 +45 +45 +75 +40 angle β -45 -45 -45 -45 -45 +15 -40 retardation layer Second floor 3rd Floor 3rd Floor 3rd Floor 3rd Floor Second floor 3rd Floor reflectivity face 0.40 9.73 1.29 1.89 1.23 0.90 6.59 side 6.05 11.66 7.12 7.35 9.57 8.01 11.9 Appearance and winding error Good Good Good Good error Good

*In Tables 1 and 2, the second skin layer has the same retardation and wavelength dispersion compared to the first skin layer, so it is not described separately.

*Angle α: the angle formed by the slow axis of the core layer with respect to the absorption axis of the polarizer

*Angle β: the angle formed by the slow axis of the first skin layer (second skin layer) with respect to the absorption axis of the polarizer

As shown in Table 1, the polarizing plate of the present invention has excellent manufacturing processability and economic feasibility because there is no appearance defect, winding inability, etc., and has improved anti-reflection performance on the front and side surfaces. As shown in Figure 5, the polarizing plate of an embodiment of the present invention had a low reflectance in both the front and the side.

On the other hand, as shown in Table 2, the polarizing plate of Comparative Example 1 composed of two retardation layers had the appearance of the retardation layer and the inability to wind. In addition, as shown in Table 1 and FIG. 5, the polarizing plate of Comparative Example 6 composed of two retardation layers had an appearance and winding inability of the retardation layer, and had poor reflection performance.

In addition, as shown in Table 2, the polarizing plates of Comparative Examples 2 to 5 and Comparative Example 7, which do not satisfy the retardation layer configuration of the present invention, also had poor reflective performance compared to the Examples.

Simple modifications or changes of the present invention can be easily carried out by those of 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 (20)

polarizer; and a laminate of retardation layers formed on one surface of the polarizer and having three or more retardation layers,
The laminate of the retardation layer includes a core layer, a first skin layer and a second skin layer respectively formed on one surface and the other surface of the core layer,
The core layer, the first skin layer, and the second skin layer satisfy the following (i) or (ii),
(i) the in-plane retardation (Re) of the core layer at a wavelength of 550 nm is 180 nm to 260 nm, and the sum of the in-plane retardation of the first skin layer and the second skin layer at a wavelength of 550 nm is 70 nm to 140 nm;
(ii) the in-plane retardation of the core layer at a wavelength of 550 nm is 70 nm to 140 nm, and the sum of the in-plane retardation of the first skin layer and the second skin layer at a wavelength of 550 nm is 180 nm to 260 nm;
An angle α formed by a slow axis of the core layer with respect to the absorption axis of the polarizer is -45° to +45°, and the first skin layer and the second skin layer are formed with respect to the absorption axis of the polarizer. The angle β formed by the slow axis each satisfies the following Equation 1, a polarizing plate:
[Equation 1]
85° ≤ ｜ angle α - angle β｜ ≤ 95°,
(In Equation 1, the angle α is not 0°).
The polarizing plate according to claim 1, wherein the angle (β) is -45° to +45°.
The polarizing plate according to claim 1, wherein any one of the core layer and the first skin layer has flat wavelength dispersion, and the other one has positive wavelength dispersion.
The polarizing plate according to claim 1, wherein one of the core layer and the second skin layer has flat wavelength dispersion, and the other one has positive wavelength dispersion.
The polarizing plate of claim 1, wherein the core layer, the first skin layer, and the second skin layer satisfy (i).
The polarizing plate according to claim 5, wherein the thickness direction retardation of the core layer at a wavelength of 550 nm is 150 nm to 180 nm.
The polarizing plate according to claim 5, wherein the core layer has a degree of biaxiality of 1.0 or more at a wavelength of 550 nm.
The polarizing plate according to claim 5, wherein the first skin layer and the second skin layer each have an in-plane retardation of 20 nm to 70 nm at a wavelength of 550 nm.
The polarizing plate according to claim 5, wherein the thickness direction retardation of each of the first skin layer and the second skin layer at a wavelength of 550 nm is -60 nm to -30 nm.
The polarizing plate according to claim 5, wherein the first skin layer and the second skin layer each have a degree of biaxiality of 0 or less at a wavelength of 550 nm.
The method of claim 5, wherein the core layer includes a cyclic polyolefin (COP)-based resin, and the first skin layer and the second skin layer each include a polycarbonate-based or modified polycarbonate-based resin, polarizer.
The polarizing plate of claim 1, wherein the core layer, the first skin layer, and the second skin layer satisfy (ii).
The polarizing plate according to claim 12, wherein the thickness direction retardation of the core layer at a wavelength of 550 nm is -100 nm to -30 nm.
The polarizing plate according to claim 12, wherein the core layer has a degree of biaxiality of 0 or less at a wavelength of 550 nm.
The polarizing plate of claim 12 , wherein the first skin layer and the second skin layer each have an in-plane retardation of 90 nm to 150 nm at a wavelength of 550 nm.
The polarizing plate of claim 12 , wherein the first skin layer and the second skin layer each have a thickness direction retardation of 50 nm to 100 nm at a wavelength of 550 nm.
The polarizing plate according to claim 12, wherein the first skin layer and the second skin layer each have a degree of biaxiality of 1.0 or more at a wavelength of 550 nm.
The polarizing plate of claim 12 , wherein the core layer includes a polycarbonate-based or modified polycarbonate-based resin, and the first skin layer and the second skin layer each include a cyclic polyolefin-based resin.
The polarizing plate according to claim 1, wherein a protective film is further formed on the other surface of the polarizer.
An optical display device comprising the polarizing plate of any one of claims 1 to 19.

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