KR20210138567A - Polarizer - Google Patents

Abstract

[Problem] To provide a polarizer that is less prone to cracking due to temperature change.
[Solution means] The polarizing plate 100 includes a polarizer layer 30 , a first optical resin film 10 provided on one surface of the polarizer layer 30 , and the other surface of the polarizer layer 30 . A second optical resin film 50 provided in the . When the polarizing plate 100 is viewed in the thickness direction, the shape of the outer peripheral edge of the polarizing plate 100 has at least one of a concave portion, a convex portion, and a curved portion. The arithmetic mean height Sa of the end surface of the polarizer layer 30 is 0.3-0.7 micrometer, or the root mean square height Sq is 0.4-0.8 micrometer.

Description

Polarizer

The present invention relates to a polarizing plate.

A polarizing plate is normally used by bonding to display panels, such as a liquid crystal cell or an organic electroluminescent element, including the polarizer layer containing a dye, and a pair of optical resin films provided on both sides of the polarizer layer. The outer periphery of the polarizing plate is usually shaped to fit the outer periphery of the display portion of the display panel.

When the outer peripheral edge of the display portion of the display panel is not rectangular in plan view and has at least one of a concave portion, a convex portion, and a curved portion, the outer peripheral edge of the polarizing plate used in the display portion also corresponds to this, and is not rectangular , has at least one of a concave portion, a convex portion, and a curved portion (see, for example, Patent Document 1).

Patent Document 1: Japanese Patent Laid-Open No. 2018-92119

As the present inventors examined, in a polarizing plate having at least one of concave, convex, and curved portions, instead of having a rectangular shape, the outer periphery of the polarizing plate has a rectangular outer peripheral edge, compared to a polarizing plate having a rectangular shape, in a moist heat environment, pigment loss from the polarizer layer It was easy to generate|occur|produce, or it became clear that the optical resin film was easy to peel from a polarizer in an end surface. Such a phenomenon tends to appear in the concave portion, the convex portion, and the curved portion or the vicinity thereof rather than the linear portion.

The present invention has been made in view of the above circumstances, and in a polarizing plate having an outer peripheral edge at least one of a concave portion, a convex portion and a curved portion, pigment loss in a moist heat environment is less likely to occur, and the end surface of the polarizer It aims at providing the polarizing plate from which the optical resin film from a layer is hard to peel.

The polarizing plate which concerns on this invention is equipped with a polarizer layer, the 1st optical resin film provided in one surface of the said polarizer layer, and the 2nd optical resin film provided in the other surface of the said polarizer layer. And, when the polarizing plate is viewed in the thickness direction, the shape of the outer peripheral edge of the polarizing plate has at least one of a concave portion, a convex portion and a curved portion, and the arithmetic mean height Sa of the end surface of the polarizer layer is 0.3 to 0.7 μm.

Further, another polarizing plate according to the present invention includes a polarizer layer, a first optical resin film provided on one surface of the polarizer layer, and a second optical resin film provided on the other surface of the polarizer layer. And the root mean square height (Sq) of the end surface of the said polarizer layer is 0.4-0.8 micrometer. The arithmetic mean height (Sa) of the end surface may be 0.3 to 0.7 μm.

In the polarizing plate of the present invention, the maximum height (Sz) of the end surface of the polarizer layer may be 5.0 μm or less.

According to the present invention, in the polarizing plate having an outer peripheral edge at least one of a concave portion, a convex portion and a curved portion, pigment loss in a moist heat environment is less likely to occur, and the optical resin film from the polarizer layer on the end surface This polarizing plate which is hard to peel is provided.

1 is a schematic cross-sectional view of a polarizing plate according to an embodiment of the present invention.
2A to 2C are top views of a polarizing plate according to an embodiment of the present invention.
Fig. 3 is a cross-sectional view perpendicular to the axis in the vicinity of the blade tip of the end mill.

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of this invention is described, referring drawings. In the drawings, equivalent components are denoted by equivalent reference numerals. The present invention is not limited to the following embodiments.

(polarizer)

The end view of the polarizing plate 100 which concerns on an example of embodiment of this invention is shown in FIG. The polarizing plate 100 according to the present embodiment includes the first optical resin film 10 , the adhesive layer 20 , the polarizer layer 30 , the adhesive layer 40 , and the second optical resin film 50 in this order. be prepared

An example of the polarizer layer 30 is a resin layer dyed with a dichroic dye such as iodine or a dichroic dye, and may be stretched. Although hydrophobic resin may be sufficient as resin which comprises this resin layer, it is hydrophilic resin normally. Examples of the hydrophilic resin are polyvinyl alcohol-based resins, polyvinyl acetate resins, and ethylene/vinyl acetate copolymer (EVA) resins. Examples of the hydrophobic resin are polyamide resins and polyester-based resins. The polarizer layer 30 may be treated with boric acid after dyeing. A typical example of the polarizer layer 30 is a resin layer in which iodine is adsorbed and oriented to a polyvinyl alcohol film. When the resin layer, which is the polarizer layer, is composed of a hydrophilic resin such as polyvinyl alcohol-based resin, moisture in and out of the outside is relatively large compared to that of the hydrophobic resin, and this causes pigment loss in a moist heat environment, and Since it is thought to become a cause of peeling of the optical resin film from a polarizer layer, according to the structure of this invention, such pigment|dye loss|omission and peeling can be suppressed.

The thickness of the polarizer layer 30 may be, for example, 2 to 30 µm, 2 to 15 µm, or 2 to 10 µm.

The 1st optical resin film 10 and the 2nd optical resin film 50 are colorless and transparent resin films normally. Examples of such a resin film include a protective film, a retardation film, a brightness enhancement (reflective polarizer) film, an anti-glare film, a surface anti-reflection film, a reflective film, a transflective film, a viewing angle compensation film, an optical compensation film, a touch sensor film, It is an antistatic film and an antifouling film.

Examples of the resin constituting each optical resin film include a cellulose-based resin (triacetyl cellulose, etc.), a polyolefin-based resin (polypropylene-based resin, etc.), a cyclic olefin-based resin (norbornene-based resin, etc.), an acrylic resin (polymethyl methacrylate resin etc.) or polyester resin (polyethylene terephthalate resin etc.) may be sufficient. The first optical resin film 10 and the second optical resin film 50 may be multilayer films.

The thickness of the 1st optical resin film 10 and the 2nd optical resin film 50 may be 5-200 micrometers, for example.

The material and thickness of the 1st optical resin film 10 and the 2nd optical resin film 50 may be mutually the same, and may be mutually different.

The adhesive layers 20 and 40 are not particularly limited as long as they are transparent materials capable of bonding the polarizer layer 30 and the first optical resin film 10 or the second optical resin film 50 to each other. One example of an adhesive is an epoxy resin. The epoxy resin may be, for example, a hydrogenated epoxy resin, an alicyclic epoxy resin, or an aliphatic epoxy resin. A polymerization initiator (a photocationic polymerization initiator, a thermal cationic polymerization initiator, a photoradical polymerization initiator, or a thermal radical polymerization initiator, etc.) or other additives (a sensitizer, etc.) may be added to the epoxy resin.

Other examples of the adhesive are acrylic resins such as acrylamide, acrylate, urethane acrylate and epoxy acrylate.

Another example of the adhesive is a water-based adhesive such as polyvinyl alcohol-based resin.

Another example of an adhesive is a pressure-sensitive adhesive. Examples of the pressure-sensitive adhesive include a pressure-sensitive adhesive containing an acrylic resin, a silicone-based resin, polyester, polyurethane, or polyether.

The polarizer layer 30 and the first optical resin film 10 may be laminated only through the adhesive layer 20 , between the polarizer layer 30 and the adhesive layer 20 , or between the adhesive layer 20 and the first optical An easily adhesive layer (not shown) may be provided between the resin films 10 . In addition, between the polarizer layer 30 and the second optical resin film 50 may be laminated only through the adhesive layer 40, between the polarizer layer 30 and the adhesive layer 40 or between the adhesive layer 40 and An easily adhesive layer (not shown) may be rolled between the 2nd optical resin films 50. The easily adhesive layer can improve the adhesive force between the adhesive bond layers 20 and 40, and the polarizer layer 30, the 1st optical resin film 10, or the 2nd optical resin film 50.

The thickness of the adhesive layer 20 may be, for example, 0.01 μm to 5 μm, 0.05 to 3 μm, or 0.1 to 1 μm. When a pressure-sensitive adhesive is used, the thickness of the adhesive layer 20 may be, for example, 2 to 500 µm, 2 to 200 µm, or 2 to 50 µm.

The overall thickness of the polarizing plate 100 may be, for example, 10-500 µm, 10-300 µm, or 10-200 µm.

A pressure-sensitive adhesive layer (adhesive layer) and a separator film may be further provided under the first optical resin film 10 or on the second optical resin film 50 . Moreover, you may provide a protection film further below the 1st optical resin film 10, or on the 2nd optical resin film 50.

A separator film is a film which can be peeled from a pressure-sensitive adhesive bond layer, and prevents adhesion of the foreign material to a pressure-sensitive adhesive bond layer. For example, when the polarizing plate 100 is adhered to an image display element, the separator film is peeled off to expose the pressure-sensitive adhesive layer. The resin constituting the separator film may be, for example, a polyethylene-based resin, a polypropylene-based resin, or a polyester-based resin (such as polyethylene terephthalate).

The protection film is a film for preventing damage to the first optical resin film 10 or the second optical resin film 50, and for example, a self-adhesive resin film may be used alone, or a resin film and a resin film laminated on the resin film. A multilayer film composed of a pressure-sensitive adhesive may be used. The protection film is peelable from the 1st optical resin film 10 or the 2nd optical resin film 50 in which this is provided. When the protection film is a multilayer film in which a pressure-sensitive adhesive is laminated on a resin film, the protection film is peeled off from the first optical resin film 10 or the second optical resin film 50 together with the pressure-sensitive adhesive. Resin of a protection film can also be made similar to a separator film.

The thickness of the separator film and the protection film may be, for example, 2 to 500 µm, 2 to 200 µm, or 2 to 100 µm.

In the polarizing plate 100 according to the present embodiment, as viewed from the thickness direction, the outer peripheral edge P of the polarizing plate 100 is not formed only by a straight line (eg, a rectangle), but from the group consisting of a concave portion, a convex portion and a curved portion. has at least one selected.

For example, like the polarizing plate 100 shown in FIG.2(a), the outer peripheral edge P is a chamfering curve provided between four linear parts PL and two linear parts PL orthogonal to neighbors, respectively. It can have a negative (PR). In other words, as for the outer peripheral edge P of this polarizing plate 100, the chamfering curve part PR is provided in each of four corner|angular parts of a rectangle.

Moreover, like the polarizing plate 100 shown in FIG.2(b), with respect to one linear part PL of the outer peripheral edge P of the polarizing plate 100 of FIG.2(a), the recessed part PD. You may provide more. Although the shape of the recessed part PD is not limited, for example, as shown in FIG.2(b), it has a substantially rectangular shape which has three linear parts PDL which are orthogonal to each other, and is between the linear parts PDL. Each may have a chamfered curved portion PDR, and each may have a chamfered curved portion PDR between the straight portion PDL and the linear portion PL. The curved portion PDR provided between the two straight portions PDL is concave toward the inside of the polarizing plate 100 . The chamfered curved part PDR provided between the linear part PDL and the linear part PL is convex toward the out-of-plane of the polarizing plate 100. As shown in FIG.

Moreover, like the polarizing plate 100 shown in FIG.2(c), with respect to one linear part PL of the outer peripheral edge P of the polarizing plate 100 of FIG.2(a), the convex part PP may be provided. Although the shape of the convex part PP is not limited, for example, as shown in FIG.2(c), it has a substantially rectangular shape which has three linear parts PPL orthogonal to each other, and is between the linear parts PPL. Each may have a chamfered curved portion PPR, and each may have a chamfered curved portion PPR between the straight portion PPL and the straight portion PL. The chamfered curve part PPR which has between the two linear parts PPL is concave toward the inside of the plane of the polarizing plate 100. As shown in FIG. The chamfered curve part PPR which has between the linear part PPL and the linear part PL is convex toward the out-of-plane of the polarizing plate 100. As shown in FIG.

There is no particular limitation on the depth of the concave portion PD from the straight portion PL and the height of the convex portion PP from the straight portion PL, but typically may be 1.0 mm or more. In addition, the width of the concave portion PD and the width of the convex portion PP are not particularly limited, but may typically be 3.0 mm or more.

The shape of the concave portion PD and the convex portion PP is not limited to a rectangle in which four angles are rounded by a chamfered curve portion, as shown in Figs. 2 (b) and (c), a simple rectangle, a semicircle, A polygonal shape etc. may be sufficient.

The curve of each chamfered curve portion may be a circular arc, an elliptical arc, or a spline curve. The radius of curvature of each chamfered curved portion can be 1.0 to 40 mm.

In addition, in the outer peripheral edge P of Fig.2 (a), 1-3 of four chamfering curve parts PR may not be a chamfering curve, but a simple angle part may be sufficient. In the outer peripheral edge P of Figs. 2(b) and (c), 1 to 4 of the four chamfered curve portions PR may be provided with a simple angle instead of a chamfered curve. In addition, the form based on the rectangle as shown to Fig.2 (a)-(c) may not be sufficient as the outer peripheral edge P, and the form based on polygons, such as a triangle and a hexagon, may be sufficient as it.

In addition, the absorption axis of the polarizer layer 30 may face any direction of the polarizing plate 100 according to the image display apparatus etc. used.

(arithmetic mean height (Sa))

Returning to FIG. 1, in the polarizing plate 100 which concerns on embodiment of this invention, the arithmetic mean height Sa of the end surface of the polarizer layer 30 of the polarizing plate 100 is 0.3-0.7 micrometers. 0.4 micrometer or more may be sufficient as Sa, and 0.6 micrometer or less may be sufficient as it.

The arithmetic mean height Sa of the end surface of the polarizer layer 30 is defined as follows in 30 A of arbitrary two-dimensional measurement areas on an end surface. Let the plane parallel to the end face of the polarizer layer 30 be the XY plane, let the height direction perpendicular to the end face be the Z direction, and the position of the average height in the two-dimensional measurement area|region 30A of the end face is Z When the XYZ coordinate system set to = 0 is defined, and the height at each x-coordinate and each y-coordinate of the two-dimensional measurement area 30A is Z(x, y), the arithmetic mean height Sa is expressed by the following formula is displayed Here, A is the area of the two-dimensional measurement area 30A.

The height Z(x, y) for each x and y in the two-dimensional measurement region 30A can be acquired by a scanning interference microscope, an atomic force microscope, or the like. The size of the two-dimensional measurement area 30A can be, for example, a rectangular area of 5 to 1000 µm per side.

(root mean square height (Sq))

In addition, the root mean square height (Sq) of the end surface of the polarizer layer 30 may be 0.4 to 0.8 μm. 0.5 micrometer or more may be sufficient as Sq, and 0.7 micrometer or less may be sufficient as it.

The root mean square height Sq in the arbitrary two-dimensional measurement area 30A is defined according to the following formula.

(maximum height (Sz))

In addition, the maximum height Sz of the end surface of the polarizer layer 30 may be 5.0 μm or less. Sz may be 4.0 µm or less.

The maximum height Sz is the sum of the absolute values of the maximum mountain height and the maximum valley depth in the two-dimensional measurement region 30A.

The measurement of the three-dimensional surface roughness in the two-dimensional measurement area 30A can be based on ISO25178.

Here, it is preferable that the two-dimensional measurement area|region 30A is any one linear part in the outer peripheral edge P, ie, a flat part in the end surface, and in the recessed part PD and the convex part PP. Planar provision may be sufficient, and planar provision on planar parts other than the recessed part PD and the convex part PP, for example, four straight-line parts PL orthogonal to each other may be sufficient.

As will be described later, unlike a polarizing plate in which the outer peripheral edge P is formed only of a straight portion, the end face of the polarizing plate having a concave portion, a convex portion, or a curved portion cannot be cut by a plane grinding device to adjust the dimensions. Therefore, the end surface of such a polarizing plate is cut with an end mill over the whole outer periphery normally. Therefore, it has substantially the same surface roughness at any of the end faces.

As for the straight part in the outer peripheral edge P, that is, the plane part in the end surface, the plane whose average height becomes 0 becomes a plane, and since it is easy to determine the plane of Z=0, the two-dimensional measurement area|region 30A It is preferable as

It is also preferable that the two-dimensional measurement area|region 30A exists in the edge part of the absorption axis (stretching direction) direction of the polarizer layer 30. Further, if the two-dimensional measurement region 30A is at the end in the absorption axis direction, the region 30A intersects the absorption axis of the polarizer layer 30 .

Since the surface area of an end surface becomes large when the arithmetic mean height Sa in the end surface of the polarizer layer 30 is large, there exists a tendency for the pigment|dye loss in a moist heat environment to become large. On the other hand, when the arithmetic mean height Sa at the end face of the polarizer layer 30 is small, the first optical resin film 10 and/or the second optical resin film 50 from the polarizer layer 30 is There exists a tendency for the peeling amount to become large easily. In addition, although the situation where Sa is small corresponds to the state which is not grinding|polishing of an end surface with punching with a Thomson blade, it is guessed that it originates in peeling of the optical resin film resulting from the impact of punching.

Since the surface area of an end surface becomes large when the root mean square height Sq in the end surface of the polarizer layer 30 is large, there exists a tendency for the pigment|dye loss in a moist heat environment to become large. On the other hand, when the root mean square height Sq in the end face of the polarizer layer 30 is small, the first optical resin film 10 and/or the second optical resin film 50 from the polarizer layer 30 are small. ) tends to increase easily.

Since the surface area of an end surface becomes large when the maximum height Sz in the end surface of the polarizer layer 30 is large, it exists in the tendency for the pigment|dye loss in a moist heat environment to become large.

Such a polarizing plate can be bonded to display panels, such as a liquid crystal cell and an organic electroluminescent element, for example, and can be utilized for image display apparatuses, such as a liquid crystal display device or an organic electroluminescent display device. The liquid crystal display device may include, for example, a liquid crystal cell and the aforementioned polarizing plate adhered to one or both surfaces of the liquid crystal cell. The organic EL display device may include, for example, an organic EL element and the above-described polarizing plate adhered to the surface of the organic EL element. In the liquid crystal cell, two polarizing plates are normally arrange|positioned.

(Manufacturing method of polarizing plate)

Then, the manufacturing method of the said polarizing plate 100 is demonstrated.

First, according to a known method, the original fabric of the polarizing plate 100 having the above-described layer configuration is manufactured. Then, the raw film is punched out with cutlery, such as a Thompson blade, and the polarizing plate in which the outer peripheral edge P has a recessed part, a convex part, or a curved part is obtained. Here, since it is difficult to ensure sufficient dimensional accuracy in the outer peripheral edge P only by cutting|disconnection with a Thomson blade, the grinding process of an end surface is performed.

When the outer peripheral edge P has a concave portion, a convex portion, or a curved portion, a plane grinding device such as that used for grinding the end surface of a rectangular polarizing plate, that is, a plurality of bites is arranged on one main surface in the circumferential direction Since it is impossible to grind the entire end face using a device that cuts the provided rotating disc in contact with the end face of the polarizing plate so that the main surface and the end face of the polarizing plate are parallel, the entire end face of the polarizing plate is cut using an end mill. cut processing. More specifically, by making the axial direction of the end mill parallel to the thickness direction of the polarizing plate and relatively moving the end mill and the polarizing plate along the end face of the polarizing plate, the end face of the polarizing plate is cut to fit a desired dimension.

Here, it is suitable to use an end mill having a spiral blade, and in particular, in the cross-sectional shape of the blade, it is preferable to use an end mill having small dZ and dZ/dX in FIG. 3 .

Here, FIG. 3 is a cross-sectional view of the tip of the blade 80 in a cross section perpendicular to the axis of the end mill, and the rotational direction of the end mill is C. As shown in FIG. This blade 80 has a blade tip 80t and a surface 80d behind the blade tip 80t. This surface 80d can contact the cutting material T immediately after cutting by the cutting edge 80t. In this embodiment, on the basis of the straight line Q connecting the cutting edge 80t and the rotation shaft AX of the end mill, the cutting edge 80t as the starting point is orthogonal to the straight line Q and the cutting edge 80t While moving along a straight line AB passing through, the profile of the height of the surface 80d with respect to the straight line AB is measured with a scanning interference microscope. Then, from this profile, dZ [μm], which is the maximum value of the height of the surface 80d, and the distance dX [μm] from the edge 80t in the AB direction giving dZ are calculated.

At this time, it is suitable to use an end mill having a cutting edge such that dZ≤1.0 µm and dZ/dX≤4. Thereby, it is easy to make the surface roughness in the end surface 20e of the polarizer layer 30 into the above-mentioned range. Even in the case of an end mill having a spiral blade, the surface roughness tends to be excessively large in an end mill having dZ>1.0 µm or dZ/dX>4.

As mentioned above, although preferred embodiment of this invention was described, this invention is not limited at all to the said embodiment.

For example, implementation is possible even without one or both of the adhesive layers 20 and 40 .

Example

Hereinafter, the content of the present invention will be described in more detail with reference to Examples and Comparative Examples. In addition, the present invention is not limited to the following examples.

[Example 1]

A polarizer (8 µm in thickness) in which iodine was adsorbed and oriented to polyvinyl alcohol-based resin was produced by stretching a 20 µm-thick polyvinyl alcohol-based resin film and dyeing it with iodine. A cyclic olefin resin (COP) film (manufactured by Nippon Zeon Corporation, 13 µm in thickness) was bonded to one side of this polarizer via a water-based adhesive. Moreover, on the COP film, the acrylic adhesive layer A (20 micrometers in thickness) formed on the peeling film was laminated|stacked. On the other surface of the polarizer, the acrylic pressure-sensitive adhesive layer B (thickness of 5 µm) formed on the release film was laminated. A luminance enhancing film (manufactured by 3M, APF-V3, 30 µm thick, reflective polarizer) having a protection film on its upper surface was bonded onto the acrylic pressure-sensitive adhesive layer B exposed by peeling the release film.

In this way, the original fabric of the polarizing plate consisting of a release film/acrylic adhesive layer A/COP film/water-based adhesive agent/polarizer/acrylic adhesive layer B/brightness improvement film/protective film was produced.

The polarizing plate 100 which has the recessed part PD of the shape of FIG.2(b) was cut out from the original fabric with a Thompson blade. The length of the long side of the rectangle is 140 mm, the length of the short side of the rectangle is 70 mm, the depth of the depression is 5 mm, the width of the depression is 30 mm, the radius of curvature of the chamfered portion PR is about 10 to 12 mm, the chamfering curve The radius of curvature of the portion PDR was approximately 3 mm. Moreover, this polarizing plate 100 has one recessed part PD. This recessed part PD is substantially rectangular. This recessed part PD has three linear parts PDL which are orthogonal to each other. Each of the straight portions PDL has a chamfered curved portion PDR.

A chamfered curved portion PDR is provided between the linear portion PDL and the linear portion PL, respectively. The absorption axis 31 of this polarizing plate 100 is orthogonal to the depth direction of the recessed part PD, and it was the left-right direction in FIG.2(b).

Using an end mill having a helical diameter blade having an average dZ of 0.6 µm and an average dZ/dX of 2.2, the entire perimeter of the end face was polished to adjust the dimensions to obtain a polarizing plate of Example 1.

(Comparative Example 1)

A polarizing plate of Comparative Example 1 was obtained in the same manner as in Example 1, except that the end face was polished using an end mill having a helical diameter blade having an average of dZ of 1.4 µm and an average of dZ/dX of 14.

(Comparative Example 2)

The polarizing plate of the comparative example 2 was obtained like the comparative example 1 except having cut off with the Thomson blade, without grinding|polishing an end surface with an end mill.

(Measurement of roughness (Sa, Sq, Sz) on a three-dimensional surface)

The height function (Z(x, y)) of the end surface of the polarizer layer was acquired with the following microscope.

Scanning White Interference Microscope VS1000 Series Hitachi High-Tech Science Co., Ltd.

Measurement conditions: Objective lens: 50×

Two-dimensional measurement area: 5 to 8 µm vertical (thickness direction) × horizontal (direction perpendicular to the thickness direction) in the straight portion (plane orthogonal to the absorption axis) of the end face of the polarizer layer (PVA layer) of the polarizing plate 150-300 μm

Based on the obtained function (Z), Sa, Sq, and Sz were respectively calculated|required based on the said formula. The end surfaces on which Sa, Sq, and Sz were measured were located on the left and right straight lines PL in FIG. 2B , and were orthogonal to the absorption axis 31 . In addition, Sa, Sq, and Sz in each polarizing plate 100 show the same value over the whole perimeter.

(Evaluation of iodine depletion)

The polarizing plate obtained by the Example or the comparative example was left to stand in the environment of 65 degreeC and 90% of relative humidity for 500 hours.

Thereafter, two polarizing plates (one of the polarizing plates of Examples or Comparative Examples, the other of commercially available normal polarizing plates) are placed on the cross nicol, and the end is observed over the entire circumference using an optical microscope, corresponding to the cross nicol. The width from the end of the area (light leakage) in which the photosensitization did not occur was measured. This light leakage occurs when iodine, which plays a role in expressing the polarization performance, is omitted. In addition, light leakage has generate|occur|produced in the vicinity of the recessed part PD in FIG. 2, The largest width|variety was calculated|required as iodine loss|extraction.

(Evaluation of Peeling Amount of Brightness Improvement Film)

Evaluation was made by a reflection microscope.

The conditions and results are shown in Table 1.

In the Example, the peeling amount of the brightness improvement film was also able to be reduced, reducing the amount of iodine loss.

The polarizing plate according to the present invention is adhered to, for example, a liquid crystal cell or an organic EL element, and is applied as an optical component constituting an image display device such as a liquid crystal television, an organic EL television, or a smart phone.

10… 1st optical resin film, 30... Polarizer layer, 50... 2nd optical resin film, P... Outer edge, PP... The convex part, PD... Concave, PR, PDR, PPR… Chamfered curved portion, 100 . . . polarizer.

Claims (4)

A polarizing plate comprising a polarizer layer, a first optical resin film provided on one surface of the polarizer layer, and a second optical resin film provided on the other surface of the polarizer layer,
When the polarizing plate is viewed in the thickness direction, the shape of the outer peripheral edge of the polarizing plate has at least one of a concave portion, a convex portion and a curved portion,
A polarizing plate having an arithmetic mean height (Sa) of 0.3 to 0.7 µm of an end surface of the polarizer layer. A polarizing plate comprising a polarizer layer, a first optical resin film provided on one surface of the polarizer layer, and a second optical resin film provided on the other surface of the polarizer layer,
When the polarizing plate is viewed in the thickness direction, the shape of the outer peripheral edge of the polarizing plate has at least one of a concave portion, a convex portion and a curved portion,
A polarizing plate having a root mean square height (Sq) of 0.4 to 0.8 µm of an end surface of the polarizer layer. The polarizing plate according to claim 2, wherein an arithmetic mean height (Sa) of an end surface of the polarizer layer is 0.3 to 0.7 µm. The polarizing plate according to any one of claims 1 to 3, wherein the maximum height (Sz) of the end surface of the polarizer layer is 5.0 µm or less.

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