JP2021047453A - Polarizer - Google Patents

Abstract

To provide a polarizer which is less likely to cause cracking accompanied by a temperature change.SOLUTION: A polarizer 100 includes a polarizer layer 30, a first optical resin film 10 provided on one surface of the polarizer layer 30, and a second optical resin film 50 provided on the other surface of the polarizer layer 30. When viewed from a thickness direction of the polarizer 100, a shape of an outer peripheral edge of the polarizer 100 has at least one of a recess, a projection and a curve part. An arithmetic average height Sa of the end face of the polarizer layer 30 is 0.3-0.7 μm or a square average square height Sq is 0.4-0.8 μm.SELECTED DRAWING: Figure 1

Description

The present invention relates to a polarizing plate.

The polarizing plate usually includes a polarizing element layer containing a dye and a pair of optical resin films provided on both sides of the polarizing element layer, and is used by being bonded to a display panel such as a liquid crystal cell or an organic EL element. The outer circumference of the polarizing plate is usually shaped to match the outer peripheral edge 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 for this display portion is also this. Corresponding to, it has at least one of a concave portion, a convex portion, and a curved portion instead of a rectangular shape (see, for example, Patent Document 1).

JP-A-2018-92119

As examined by the present inventors, a polarizing plate having an outer peripheral edge not having a rectangular shape but having at least one of a concave portion, a convex portion, and a curved portion has a wet heat as compared with a polarizing plate having a rectangular outer peripheral edge. It has been found that the dye is easily removed from the polarizing element layer in the environment, and the optical resin film is easily peeled off from the polarizer at the end face. Such a phenomenon is more likely to appear in the concave portion, the convex portion, the curved portion, and the vicinity thereof than in the straight portion.

The present invention has been made in view of the above circumstances, and in a polarizing plate having an outer peripheral edge having at least one of a concave portion, a convex portion, and a curved portion, dye loss in a moist heat environment is unlikely to occur, and the present invention is made. An object of the present invention is to provide a polarizing plate in which the optical resin film is not easily peeled off from the polarizer layer on the end face.

The 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. , Equipped with. When the polarizing plate is viewed from 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 of the end face of the polarizing element layer. Sa is 0.3 to 0.7 μm.

Further, another polarizing plate according to the present invention includes a polarizing element layer, a first optical resin film provided on one surface of the polarizer layer, and a second polarizing plate provided on the other surface of the polarizer layer. It includes an optical resin film. The root mean square height Sq of the end face of the polarizer layer is 0.4 to 0.8 μm. The arithmetic mean height Sa of the end face can be 0.3 to 0.7 μm.

The polarizing plate of the present invention can have a maximum height Sz of the end face of the polarizer layer of 5.0 μm or less.

According to the present invention, in a polarizing plate having an outer peripheral edge having at least one of a concave portion, a convex portion, and a curved portion, pigment loss is unlikely to occur in a moist heat environment, and optics from the polarizer layer at the end face. A polarizing plate that prevents the resin film from peeling off is provided.

FIG. 1 is a schematic cross-sectional view of a polarizing plate according to an embodiment of the present invention. 2 (a) to 2 (c) are top views of the polarizing plate according to the embodiment of the present invention. FIG. 3 is a cross-sectional view perpendicular to the axis near the cutting edge of the end mill.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the drawings, equivalent components are designated by the same reference numerals. The present invention is not limited to the following embodiments.

(Polarizer)
FIG. 1 shows an end view of the polarizing plate 100 according to an example of the embodiment of the present invention. The polarizing plate 100 according to the present embodiment includes a first optical resin film 10, an adhesive layer 20, a polarizer layer 30, an adhesive layer 40, and a second optical resin film 50 in this order.

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. The resin constituting this resin layer may be a hydrophobic resin, but is usually a hydrophilic resin. Examples of hydrophilic resins are polyvinyl alcohol-based resins, polyvinyl acetate resins and ethylene-vinyl acetate copolymer resins (EVA) resins. Examples of hydrophobic resins are polyamide resins and polyester resins. The polarizer layer 30 may be treated with boric acid after staining. A typical example of the polarizer layer 30 is a resin layer in which iodine is adsorbed and oriented on a polyvinyl alcohol film. When the resin layer, which is the polarizer layer, is composed of a hydrophilic resin such as a polyvinyl alcohol-based resin, the amount of moisture entering and exiting from the outside is relatively larger than that of the hydrophobic resin, which causes pigment loss in a moist heat environment. Further, it is considered that the optical resin film is peeled off from the polarizing element layer on the end face. However, according to the configuration of the present invention, such dye loss 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 first optical resin film 10 and the second optical resin film 50 are usually colorless and transparent resin films. Examples of such resin films include protective films, retardation films, brightness-enhancing (reflective polarizer) films, antiglare films, surface antireflection films, reflective films, transflective reflective films, viewing angle compensation films, and optical compensation. Films, touch sensor films, antistatic films and antifouling films.

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

The thickness of the first optical resin film 10 and the second optical resin film 50 may be, for example, 5 to 200 μm.

The materials and thicknesses of the first optical resin film 10 and the second optical resin film 50 may be the same or different from each other.

The adhesive layers 20 and 40 are not particularly limited as long as they are transparent materials capable of adhering the polarizer layer 30 to the first optical resin film 10 or the second optical resin film 50. 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 (photocationic polymerization initiator, thermal cationic polymerization initiator, photoradical polymerization initiator or thermal radical polymerization initiator, etc.) or other additive (sensitizer, etc.) may be added to the epoxy resin. ..

Other examples of adhesives are acrylic resins such as acrylamide, acrylates, urethane acrylates, and epoxy acrylates.

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

Another example of an adhesive is a pressure sensitive adhesive. An example of a pressure-sensitive adhesive is a pressure-sensitive adhesive containing an acrylic resin, a silicone resin, a polyester, a polyurethane, a polyether, or the like.
The polarizer layer 30 and the first optical resin film 10 may be laminated only via the adhesive layer 20, between the polarizer layer 30 and the adhesive layer 20, or between the adhesive layer 20 and the first. An easy-adhesion layer (not shown) may be provided between the optical resin film 10 and the film 10. Further, the polarizing element layer 30 and the second optical resin film 50 may be laminated only via the adhesive layer 40, between the polarizing element layer 30 and the adhesive layer 40, or between the adhesive layer 40. An easy-adhesive layer (not shown) may be provided between the 40 and the second optical resin film 50. The easy-adhesive layer can improve the adhesive force between the adhesive layers 20 and 40 and the polarizer layer 30, the first optical resin film 10 or the second 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 total thickness of the polarizing plate 100 may be, for example, 10 to 500 μm, 10 to 300 μm, or 10 to 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. Further, a protective film may be further provided under the first optical resin film 10 or on the second optical resin film 50.

The separator film is a film that can be peeled off from the pressure-sensitive adhesive layer, and prevents foreign matter from adhering to the pressure-sensitive adhesive layer. For example, when the polarizing plate 100 is attached 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 tree (polyethylene terephthalate or the like).
The protective film is a film for preventing the first optical resin film 10 or the second optical resin film 50 from being scratched. For example, the self-adhesive resin film may be used alone, or the resin film and the resin thereof. It may be a multilayer film composed of a pressure-sensitive adhesive laminated on the film. The protective film can be peeled off from the first optical resin film 10 and the second optical resin film 50 on which the protective film is provided. When the protective film is a multilayer film in which a pressure-sensitive adhesive is laminated on a resin film, the protect film is peeled off from the first optical resin film 10 or the second optical resin film 50 together with the pressure-sensitive adhesive. The resin of the protective film can be the same as that of the separator film.

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

When viewed from the thickness direction of the polarizing plate 100 according to the present embodiment, the outer peripheral edge P of the polarizing plate 100 is not formed only of straight lines (for example, a rectangle), but is composed of concave portions, convex portions, and curved portions. Have at least one selected from the group.

For example, as in the polarizing plate 100 shown in FIG. 2A, the outer peripheral edge P has four straight line portions PL that are orthogonal to each other and a chamfered curved portion PR that is provided between the two straight line portions PL. Can have. In other words, the outer peripheral edge P of the polarizing plate 100 is provided with a chamfered curved portion PR at each of the four corners of the rectangle.

Further, as in the polarizing plate 100 shown in FIG. 2B, a recess PD may be further provided in one straight portion PL of the outer peripheral edge P of the polarizing plate 100 in FIG. 2A. The shape of the concave PD is not limited, but for example, as shown in FIG. 2B, it has a substantially rectangular shape having three straight PDLs orthogonal to each other, and chamfered curved portions are formed between the straight PDLs. The shape may have a PDR and a chamfered curved portion PDR between the straight portion PDL and the straight portion PL, respectively. The curved portion PDR held between the two straight portions PDL has a concave shape toward the in-plane of the polarizing plate 100. The chamfered curved portion PDR held between the straight portion PDL and the straight portion PL has a convex shape toward the outside of the plane of the polarizing plate 100.

Further, as in the polarizing plate 100 shown in FIG. 2 (c), even if the convex portion PP is provided with respect to one straight portion PL of the outer peripheral edge P of the polarizing plate 100 in FIG. 2 (a). Good. The shape of the convex portion PP is not limited, but for example, as shown in FIG. 2C, it is a substantially rectangular shape having three straight portion PPLs orthogonal to each other, and chamfer curves are formed between the straight portions PPLs. The shape may have a portion PPR and a chamfered curved portion PPR between the straight portion PPL and the straight portion PL, respectively. The chamfered curved portion PPR between the two straight portions PPL has a concave shape toward the in-plane of the polarizing plate 100. The chamfered curved portion PPR held between the straight portion PPL and the straight portion PL has a convex shape toward the outside of the plane of the polarizing plate 100.

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 are not particularly limited, but can typically be 1.0 mm or more. Further, the width of the concave portion PD and the width of the convex portion PP are not particularly limited, but can typically be 3.0 mm or more.

The shapes of the concave PD and the convex PP are not limited to rectangles having four corners rounded by chamfered curved portions as shown in FIGS. 2 (b) and 2 (c), but are simply rectangles, semicircles, polygons, etc. But it may be.

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

Further, in the outer peripheral edge P of FIG. 2A, 1 to 3 of the four chamfered curve portions PR may be simple corner portions that are not chamfered curves. In the outer peripheral edge P of FIGS. 2B and 2C, 1 to 4 of the four chamfered curved portions PR may be simple corner portions that are not chamfered curves. Further, the outer peripheral edge P does not have to be a rectangular-based form as shown in FIGS. 2A to 2C, but may be a polygon-based form such as a triangle or a hexagon.

Further, the absorption axis of the polarizer layer 30 can be oriented in any direction of the polarizing plate 100 depending on the image display device or the like used.

(Arithmetic mean height Sa)
Returning to FIG. 1, in the polarizing plate 100 according to the embodiment of the present invention, the arithmetic mean height Sa of the end face of the polarizing element layer 30 of the polarizing plate 100 is 0.3 to 0.7 μm. Sa may be 0.4 μm or more, and may be 0.6 μm or less.

The arithmetic mean height Sa of the end face of the polarizer layer 30 is defined as follows in any two-dimensional measurement region 30A on the end face. An XYZ coordinate system in which the plane parallel to the end face of the polarizer layer 30 is the XY plane, the height direction perpendicular to the end face is the Z direction, and the position of the average height of the end face in the two-dimensional measurement region 30A is Z = 0. When 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 average height Sa is expressed by the following equation. Here, A is the area of the two-dimensional measurement region 30A.

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

(Root mean square Sq)
Further, the root mean square height Sq of the end face of the polarizer layer 30 can be 0.4 to 0.8 μm. Sq may be 0.5 μm or more, and may be 0.7 μm or less.

The root mean square height Sq in any two-dimensional measurement region 30A is defined by the following equation.

(Maximum height Sz)
Further, the maximum height Sz of the end face of the polarizer layer 30 can be 5.0 μm or less. Sz may be 4.0 μm or less.

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

The measurement of the three-dimensional surface roughness in the two-dimensional measurement region 30A can conform to ISO25178.

Here, the two-dimensional measurement region 30A is preferably any straight portion on the outer peripheral edge P, that is, a flat portion on the end face, and may be a flat portion in the concave portion PD and the convex portion PP. , A flat surface portion other than the concave portion PD and the convex portion PP, for example, a flat surface portion on four straight line portions PL that are orthogonal to each other.

As will be described later, unlike a polarizing plate in which the outer peripheral edge P is formed only from a straight portion, the end face of a polarizing plate having a concave portion, a convex portion, or a curved portion cannot be cut by a surface grinding device to adjust the dimensions. .. Therefore, the end face of such a polarizing plate is usually cut by an end mill over the entire outer circumference. Therefore, it has almost the same surface roughness at any place on the end face.
The straight portion on the outer peripheral edge P, that is, the flat portion on the end surface is preferable as the two-dimensional measurement region 30A because the plane having an average height of 0 is a flat surface and the plane with Z = 0 can be easily determined.

It is also preferable that the two-dimensional measurement region 30A is located at the end of the polarizer layer 30 in the absorption axis (stretching direction) direction. When the two-dimensional measurement region 30A is located at the end in the absorption axis direction, this region 30A intersects the absorption axis of the polarizer layer 30.

When the arithmetic mean height Sa on the end face of the polarizer layer 30 is large, the surface area of the end face is large, so that the pigment loss in a moist heat environment tends to be large. On the other hand, if the arithmetic mean height Sa on the end face of the polarizer layer 30 is small, the amount of peeling of the first optical resin film 10 and / or the second optical resin film 50 from the polarizer layer 30 tends to be large. .. The situation where Sa is small corresponds to the state where the end face is not polished while being punched with the Thomson blade, but it is presumed that it is caused by the peeling of the optical resin film due to the impact of punching.

When the root mean square height Sq of the end face of the polarizer layer 30 is large, the surface area of the end face is large, so that the pigment loss in a moist heat environment tends to be large. On the other hand, when the root mean square height Sq at the end face of the polarizer layer 30 is small, the amount of peeling of the first optical resin film 10 and / or the second optical resin film 50 from the polarizer layer 30 tends to be large. There is.

When the maximum height Sz at the end face of the polarizer layer 30 is large, the surface area of the end face becomes large, so that the pigment element escape tends to be large in a moist heat environment.

Such a polarizing plate can be attached to a display panel such as a liquid crystal cell or an organic EL element and used in an image display device such as a liquid crystal display device or an organic EL display device. The liquid crystal display device may include, for example, a liquid crystal cell and the above-mentioned polarizing plate attached to one surface or both surfaces of the liquid crystal cell. The organic EL display device may include, for example, an organic EL element and the above-mentioned polarizing plate attached to the surface of the organic EL element. Two polarizing plates are usually arranged in the liquid crystal cell.

(Manufacturing method of polarizing plate)
Subsequently, a method for manufacturing the above-mentioned polarizing plate 100 will be described.
First, the raw fabric of the polarizing plate 100 having the above-mentioned layer structure is manufactured by a known method. Subsequently, the raw film is punched out with a blade such as a Thomson blade to obtain a polarizing plate having an outer peripheral edge P having a concave portion, a convex portion, or a curved portion. Here, since it is difficult to secure sufficient dimensional accuracy at the outer peripheral edge P only by cutting with the Thomson blade, the end face grinding step is performed.

When the outer peripheral edge P has a concave portion, a convex portion, or a curved portion, a surface grinding device such as that used for end face grinding of a rectangular polarizing plate, that is, a plurality of bites are provided side by side in the circumferential direction on one main surface. Since it is not possible to grind the entire end face using a device that cuts a rotating disk in contact with the end face of the polarizing plate so that its main surface and the end face of the polarizing plate are parallel to each other, an end mill is used. The entire end face of the polarizing plate is machined. More specifically, the axial direction of the end mill is parallel to the thickness direction of the polarizing plate, and the end face of the polarizing plate is relatively moved along the end face of the polarizing plate to cut the end face of the polarizing plate to obtain desired dimensions. To match.

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

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 rotation direction of the end mill is C. The blade 80 has a cutting edge 80t and a surface 80d behind the cutting edge 80t. This surface 80d may come into contact with the cutting object T immediately after cutting by the cutting edge 80t. In the present embodiment, scanning interference is performed while moving along a straight line AB that is orthogonal to the straight line Q and passes through the cutting edge 80t, with the cutting line 80t as a reference and the straight line Q connecting the cutting edge 80t and the rotation axis AX of the end mill as a reference. The profile of the height of the surface 80d with respect to the straight line AB is measured with a 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 cutting edge 80t in the AB direction, which gives dZ, are obtained.

At this time, it is preferable to use an end mill having a cutting edge in which dZ ≦ 1.0 μm and dZ / dX ≦ 4. As a result, the surface roughness of the end face 20e of the polarizer layer 30 can be easily set within the above range. Even in an end mill having a spiral blade, the surface roughness tends to be too large in an end mill having dZ> 1.0 μm or dZ / dX> 4.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

For example, it can be carried out without one or both of the adhesive layers 20 and 40.

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

[Example 1]
A polyvinyl alcohol-based resin film having a thickness of 20 μm was stretched and dyed with iodine to prepare a polarizer (thickness: 8 μm) in which iodine was adsorbed and oriented on the polyvinyl alcohol-based resin. A cyclic olefin resin (COP) film (manufactured by Nippon Zeon Corporation, thickness 13 μm) was attached to one surface of the polarizer via an aqueous adhesive. Further, an acrylic pressure-sensitive adhesive layer A (thickness 20 μm) formed on the release film was laminated on the COP film. An acrylic pressure-sensitive adhesive layer B (thickness 5 μm) formed on the release film was laminated on the other surface of the polarizer. A brightness-enhancing film (manufactured by 3M, APF-V3, thickness 30 μm, reflective polarizer) having a protective film on the upper surface was laminated on the acrylic pressure-sensitive adhesive layer B exposed by peeling the release film.
In this way, the original fabric of the polarizing plate composed of the release film / acrylic pressure-sensitive adhesive layer A / COP film / water-based adhesive / polarizer / acrylic pressure-sensitive adhesive layer B / brightness improving film / protect film was produced.

A polarizing plate 100 having a concave PD having the shape shown in FIG. 2 (b) was cut out from the original fabric using a Thomson 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 dent is 5 mm, the width of the dent is 30 mm, the radius of curvature of the chamfered curved portion PR is approximately 10 to 12 mm, and the chamfered curved portion PDR. The radius of curvature of was approximately 3 mm. The polarizing plate 100 has one recessed PD. The recess PD is substantially rectangular. This recessed PD has three linear portions PDL that are orthogonal to each other next to each other. A chamfered curved portion PDR is provided between the straight portion PDLs. A chamfered curved portion PDR is provided between the straight portion PDL and the straight portion PL, respectively. The absorption axis 31 of the polarizing plate 100 was orthogonal to the depth direction of the recess PD, and was in the left-right direction in FIG. 2B.

Using an end mill having a blade having a spiral diameter with an average dZ of 0.6 μm and an average dZ / dX of 2.2, the entire circumference of the end face was polished to adjust the dimensions, and the polarizing plate of Example 1 was used. Obtained.

(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 blade having an average dZ of 1.4 μm and an average dZ / dX of 14 spiral diameters. ..

(Comparative Example 2)
A polarizing plate of Comparative Example 2 was obtained in the same manner as in Comparative Example 1 except that the end face was not polished by an end mill and was cut out by a Thomson blade.

(Measurement of roughness Sa, Sq, Sz on a three-dimensional surface)
The height function Z (x, y) of the end face of the polarizer layer was obtained by the following microscope.
Scanning white interference microscope VS1000 series Hitachi High-Tech Science Corporation Measurement conditions: Objective lens: 50 x
Two-dimensional measurement area: Vertical (thickness direction) 5 to 8 μm × horizontal (direction perpendicular to the thickness direction) 150 to the straight portion (plane orthogonal to the absorption axis) of the end face of the polarizing element layer (PVA layer) of the polarizing plate. 300 μm
Based on the obtained function Z, Sa, Sq and Sz were obtained, respectively, based on the above equation. The end faces on which Sa, Sq and Sz were measured were located on the left and right straight line portions 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 circumference.

(Evaluation of iodine loss)
The polarizing plate obtained in Example or Comparative Example was left in an environment of 65 ° C. and 90% relative humidity for 500 hours.
After that, two polarizing plates (one of which is a polarizing plate of an example or a comparative example and the other of which is a commercially available ordinary polarizing plate) are placed on the cross Nicol, and the end portion is observed over the entire circumference using an optical microscope. , The width from the end of the region (light loss) corresponding to the cross Nicol where dimming does not occur was measured. This light leakage is caused by the removal of iodine, which plays a role in developing polarization performance. The light leakage occurred in the vicinity of the recess PD in FIG. 2, and the maximum width thereof was determined as the iodine leakage.

(Evaluation of the amount of peeling of the brightness improving film)
It was evaluated by a reflective microscope.

The conditions and results are shown in Table 1.

In the examples, the amount of peeling of the brightness improving film could be reduced while reducing the amount of iodine removed.

The polarizing plate according to the present invention is attached 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 smartphone.

10 ... First optical resin film, 30 ... Polarizer layer, 50 ... Second optical resin film, P ... Outer peripheral edge, PP ... Convex part, PD ... Concave part, PR, PDR, PPR ... Chamfered curved part, 100 ... Polarizing plate ..

Claims (4)

A polarizing plate including a polarizing element 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 from 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 the end face of the polarizer layer of 0.3 to 0.7 μm. A polarizing plate including a polarizing element 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 from 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 on the end face of the polarizer layer. The polarizing plate according to claim 2, wherein the arithmetic mean height Sa of the end face 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 face of the polarizer layer is 5.0 μm or less.

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