KR102410190B1 - Polarizers, polarizers and image display devices - Google Patents

Abstract

[Problem] To provide a polarizer that is less prone to cracking due to temperature change.
[Solutions] The average height Rc of the roughness curve elements on the end face 2a of the film-type polarizer 2 is 0.05 to 1.7 µm.

Description

Polarizers, polarizers and image display devices

The present invention relates to a polarizer, a polarizing plate, and an image display device.

In recent years, thickness reduction of the image display apparatus provided with a liquid crystal cell, an organic electroluminescent element, etc. is calculated|required.

Therefore, the polarizer for image display apparatuses is also shape|molded in the thin film form. Since a film-type polarizer is fragile and easily torn, in order to protect a polarizer, in manufacture of a polarizing plate, a protective film is bonded on both surfaces of a polarizer. Moreover, in manufacture of a polarizing plate, in order to raise the dimensional accuracy of a polarizing plate, the edge part of the laminated body comprised from a protective film, a polarizer, etc. is grind|polished (for example, refer patent document 1.).

Patent Document 1: Japanese Patent No. 3875331

Recently, a polarizing plate in which a protective film is bonded to only one surface of the polarizer has been developed in order to make the polarizing plate thin. However, in the polarizer in which the protective film is overlapped only on one surface, a crack (crack) is easy to generate|occur|produce compared with the polarizer in which the protective film overlaps both surfaces. This crack is due to the expansion or contraction of the polarizer according to the temperature change. In particular, it became clear that a crack was easy to generate|occur|produce by the rapid temperature change (heat shock) of a polarizer.

Also, in recent years, a narrow frame of the image display device is required to improve design. According to this request|requirement, high dimensional precision is calculated|required also for the edge part of a polarizing plate. In order to adjust the dimension of a polarizing plate with high precision, it is necessary to cut (polish) with high precision the edge part of the laminated body comprised from a protective film and a polarizer. However, in the polarizer in which the protective film is overlapped only on one surface, compared to the polarizer in which the protective film is overlapped on both surfaces, a load is easily applied to the end surface of the polarizer during cutting, and the end surface of the polarizer is likely to be rough. The roughness of this end face causes cracks in the polarizer according to the temperature change. In particular, it turned out that a crack is easy to generate|occur|produce in the end surface of the polarizer located in the surface side where a protective film is not in it compared with the end surface of the polarizer located in the surface side where a protective film overlaps.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polarizer with high dimensional accuracy and less prone to cracking due to temperature change, a polarizing plate provided with the polarizer, and an image display device including the polarizing plate.

The polarizer according to one aspect of the present invention is a film-type polarizer, and the average height (Rc) of the roughness curve element on the end surface of the polarizer is 0.05 to 1.7 µm. The average height Rc may be 0.05 to 0.28 µm.

A polarizing plate according to an aspect of the present invention includes the above-described polarizer and a first optical film overlapping one surface of the polarizer.

In one aspect of the present invention, a first side of the sides surrounding one end surface of the polarizer is adjacent to the first optical film, and a second side of the sides surrounding the end surface is located opposite to the first side, provided that 0.03-0.15 micrometers may be sufficient as the root mean square roughness Rq in the part along the 2nd side among negative surfaces.

In one aspect of the present invention, the first optical film may be a protective film.

The polarizing plate according to one aspect of the present invention may further include a pressure-sensitive adhesive layer overlapping the other surface of the polarizer, and a second optical film overlapping the pressure-sensitive adhesive layer.

The polarizing plate according to an aspect of the present invention may further include a pressure-sensitive adhesive layer overlapping the first optical film and a second optical film overlapping the pressure-sensitive adhesive layer.

In one aspect of the present invention, the second optical film may be a reflective polarizer.

An image display device according to an aspect of the present invention includes the above-described polarizing plate.

ADVANTAGE OF THE INVENTION According to this invention, a polarizer with high dimensional accuracy and cracks by temperature change hardly generate|occur|produces, a polarizing plate provided with this polarizer, and the image display apparatus containing the said polarizing plate can be provided.

Fig. 1 (a) is a schematic perspective view of a polarizing plate according to an embodiment of the present invention, and Fig. 1 (b) is a schematic view of a part (part b) of an end surface of the polarizing plate shown in Fig. 1 (a). It is an enlarged view.
2 is a side view of a cutting tool used for manufacturing a polarizing plate according to an embodiment of the present invention.
FIG. 3 is a front view of the cutting tool shown in FIG. 3 .
It is a schematic diagram which shows the position of the laminated body comprised from the cutting tool shown in FIG. 2, and a some polarizing plate.
It is a schematic diagram which shows the position of the laminated body comprised from the cutting tool shown in FIG. 3, and a some polarizing plate.

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of this invention is described, referring drawings. In the drawings, equal reference numerals are assigned to equal components. The present invention is not limited to the following embodiments. X, Y, and Z shown in each figure mean three mutually orthogonal coordinate axes. The direction indicated by each coordinate axis is common to all drawings. The dimensions and proportions of the dimensions shown do not necessarily correspond to the actual ones.

[Polarizer, polarizer and image display device]

As shown in FIG. And the pressure-sensitive adhesive layer 5 superposed on the other surface of the polarizer 2, and the 2nd optical film 4 superposed|stacked on the pressure-sensitive adhesive layer 5 are provided. The first optical film is, for example, a protective film 3 . The second optical film is, for example, a reflective polarizer 4 . The polarizer 2 included in the polarizing plate 1, and both the optical film and the layer may be transparent. In the polarizing plate 1 according to the present embodiment, only on one surface of the polarizer 2, the optical film (first optical film) is directly in close contact with the polarizer 2 through the adhesive layer without passing through the pressure-sensitive adhesive layer.

The polarizer 2, the first optical film 3, the pressure-sensitive adhesive layer 5, and the second optical film 4 are all rectangles having substantially the same dimensions. The entire polarizing plate 1 is also a rectangular film. However, since each shape, such as the polarizer 2 and the polarizing plate 1, depends on the surface shape of the image display element to which the polarizing plate 1 adheres, it is not limited. The shape of each of the polarizer 2 and the polarizing plate 1 may be, for example, a polygon, a circle, or an ellipse. A part or all of the outline of each of the polarizer 2 and the polarizing plate 1 may be a straight line or a curved line may be sufficient as it.

The image display device according to the present embodiment may be, for example, 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 polarizing plate 1 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 polarizing plate 1 adhered to the surface of the organic EL element. Two polarizing plates are normally arrange|positioned in a liquid crystal cell. The polarizer with which the polarizing plate arrange|positioned at the back side of a liquid crystal cell is provided is easy to be exposed to a heat|fever compared with the polarizer with which the polarizing plate arrange|positioned at the visual recognition side of a liquid crystal cell is equipped. Therefore, when the polarizing plate 1 provided with the polarizer 2 which concerns on this embodiment is arrange|positioned on the back side of a liquid crystal cell, the crack of the polarizer 2 accompanying a temperature change is suppressed. The reason will be described later.

The average height Rc of the roughness curve element on the end face 2a of the polarizer 2 is 0.05 to 1.7 µm. The average height Rc may be 0.05 to 0.28 µm, 0.07 to 1.7 µm, 0.07 to 1.604 µm, 0.07 to 1.0 µm, or 0.07 to 0.28 µm. The average height Rc of the roughness curve elements on the end face 2a may be defined, for example, by the following formula (1).

In Equation 1, Rc is the average of the heights Zt of the roughness curve elements (contour curve elements) at the reference length l. i is a natural number 1 or more and m or less, and m is a natural number 2 or more. Zti is the height of the i-th contour curve element in the reference length l. The contour curve element is a set of adjacent mountains and valleys, and the height Zt of the contour curve element is the difference between a set of adjacent peaks (maximum) and valleys (minimum values). Rc may be measured on the end face 2a of the polarizer 2 by, for example, a laser microscope.

The larger the average height Rc of the roughness curve elements on the end face 2a, that is, the rougher the end face 2a, the non-uniformly deformed end face 2a due to expansion or contraction according to temperature change. In particular, the end surface 2a is non-uniform and rapidly deformed due to rapid expansion or contraction due to heat shock. When the polarizer 2 is stretched in the uniaxial direction or the biaxial direction, the expansion or contraction of the polarizer 2 is anisotropic. By these factors, a crack is easy to generate|occur|produce in the polarizer 2 with the end surface 2a as a starting point according to the temperature change of the polarizer 2 . For example, a crack is generated starting from the curve of the contour curve element (that is, a deep recess in the end face 2a). However, in this embodiment, since the average height Rc of the roughness curve element in the end surface 2a is 0.05-1.7 micrometers, the various factors of cracks as mentioned above are reduced, and the polarizer 2 according to temperature change ) crack generation is suppressed. The length of cracks formed on the end face 2a with an average height Rc of 0.05 to 1.7 μm tends to be shorter than the length of cracks formed on the end face 2a with an average height Rc greater than 1.7 μm. . When the protective film is in close contact with both surfaces of the polarizer 2, the average height Rc of the roughness curve element on the end face 2a of the polarizer 2 is substantially uniform over the entire end face 2a. . On the other hand, when the protective film is in close contact with only one surface side of the polarizer 2, the average height Rc of the roughness curve element on the end surface 2a of the polarizer 2 is between the polarizer 2 and the protective film It tends to increase with distance from the interface (adhesive surface). Since the polarizer 2 is a stretched film, it is easy to tear, and especially the end surface of the polarizer located on the surface side without a protective film is easy to be rubbed off with a grinding|polishing blade. Therefore, the average height Rc of the roughness curve element in the end surface 2a of the polarizer 2 tends to become large as it moves away from the interface of the polarizer 2 and a protective film. When the average height Rc of the roughness curve element on the end face 2a of the polarizer 2 is not uniform, the average height Rc of the roughness curve element measured on the end face 2a of the polarizer 2 ) may be, for example, 0.05 to 0.28 µm. When the average height Rc of the roughness curve elements on the end face 2a of the polarizer 2 is not uniform, the maximum value of the average height Rc is 0.05 to 0.28 μm. Cracks formed in the end face 2a The length of ? tends to be shorter than the length of cracks formed in the end face 2a, where the maximum value of the average height Rc is greater than 0.28 mu m. In addition, when the average height Rc of the roughness curve element on the end surface 2a of the polarizer 2 is not uniform, the maximum value of the average height Rc is 0.05 to 0.28 µm formed on the end surface 2a The number of cracks used tends to be smaller than the number of cracks formed in the end face 2a having a maximum average height Rc greater than 0.28 µm.

When the end face of the polarizer or polarizing plate is not polished, since the end face of the polarizer is not roughened by polishing, the average height Rc of the end face of the polarizer is approximately zero, and cracks are unlikely to occur in the end face of the polarizer. In other words, the smaller the average height Rc of the end face 2a is, the less crack is generated in the end face of the polarizer. However, if the end face of the polarizer or the polarizing plate is not polished, it is difficult to adjust the dimensions of the polarizer or the polarizing plate to a desired value (eg, a tolerance range of product specifications) with high precision. Therefore, the dimensional accuracy of the polarizer whose average height Rc of the end surface 2a is less than 0.05 micrometer is inferior to the dimensional accuracy of the polarizer whose average height Rc of the end surface 2a is 0.05 micrometer or more. In other words, the dimensional accuracy of a polarizer having a polished end face is higher than that of a polarizer having an unpolished end face.

The rectangular polarizer 2 has four end faces 2a. 0.05-1.7 micrometers may be sufficient as average height Rc of the roughness curve element in some end surfaces 2a among the some end surfaces 2a which the polarizer 2 has. 0.05-1.7 micrometers may be sufficient as average height Rc of the roughness curve element in all the end surfaces 2a which the polarizer 2 has. The crack generation in the polarizer 2 is easily suppressed, so that there are many end surfaces 2a whose Rc is 0.05-1.7 micrometers.

As shown in Fig. 1B, one end surface 2a of the polarizer 2 has a first side S1, a second side S2, a third side S3, and a fourth side ( It is surrounded by S4). In other words, the peripheral portion of the end face 2a is constituted by a first side S1 , a second side S2 , a third side S3 , and a fourth side S4 . Among the four directions surrounding the end face 2a, the first side S1 is adjacent to the protective film 3 (first optical film). Among the four directions surrounding the end surface 2a, the second side S2 is located opposite to the first side S1. In other words, the second side S2 is adjacent to the pressure-sensitive adhesive layer 5 . The second side S2 is a side not adjacent to the protective film 3 .

0.03-0.50 micrometers may be sufficient as the root mean square roughness Rq in the part 2as along the 2nd side S2 among the end surfaces 2a. Below, the part along 2nd side S2 among the end surfaces 2a may be described as "side part 2as" of the end surface 2a. The root mean square roughness Rq may be 0.03 to 0.466 µm, 0.03 to 0.30 µm, 0.03 to 0.15 µm, or 0.031 to 0.081 µm. The root mean square roughness Rq in the side part 2as of the end face 2a may be defined, for example by the following formula (2).

In Equation 2, l (alphabet L) is the reference length in the side portion 2as of the end face 2a. Z(x) is the height of the roughness curve at any position x on the reference length l. Rq may be measured at the side 2as of the end face 2a by, for example, a laser microscope. In other words, Rq may be measured along the second side S2 of the end face 2a of the polarizer 2 . The width of the side part 2as in the thickness direction (Z-axis direction) of the polarizer 2 may be as narrow as the measurement of Rq is possible. For example, when the end face 2a of the polarizer 2 is equally divided into two regions at the middle (center) of the first side S1 and the second side S2, Rq is the protective film ( It can be said that it is an index indicating the mechanical strength of the half on the side of the second side S2 without 3). Therefore, the width of the side part 2as in the thickness direction (Z-axis direction) of the polarizer 2 may be less than half of the thickness of the polarizer 2 . The width of the side part 2as in the thickness direction (Z-axis direction) of the polarizer 2 may be substantially the same as the spot diameter of the laser used for the measurement of Rq. The width corresponding to the measurement limit of Rq using a laser microscope may be sufficient as the width|variety of the side part 2as in the thickness direction (Z-axis direction) of the polarizer 2.

On the side of the first side S1 to which the protective film 3 is adhered, the expansion or contraction of the polarizer 2 according to the temperature change is greater than on the side of the second side S2 without the protective film 3 . is likely to be suppressed by

In contrast, the side portion 2as located on the side of the second side S2 without the protective film 3 expands or contracts according to the change in temperature compared to the side of the first side S1 to which the protection film 3 is adhered. easy to do. In addition, as the Rq of the side portion 2as positioned on the second side S2 side without the protective film 3 increases, the side portion 2as is non-uniformly deformed due to expansion or contraction according to a temperature change. That is, the rougher the side portion 2as is, the more likely the side portion 2as is non-uniformly deformed due to expansion or contraction according to a temperature change. In particular, the side portion 2as is non-uniform and easily deformed rapidly due to rapid expansion or contraction due to heat shock. When the polarizer 2 is stretched in the uniaxial direction or the biaxial direction, the expansion or contraction of the polarizer 2 is anisotropic. According to these factors, a crack is easy to generate|occur|produce in the polarizer 2 with the side part 2as as a starting point in accordance with the temperature change of the polarizer 2 . In other words, with the temperature change of the polarizer 2, a crack is easy to generate|occur|produce in the part along the 2nd side S2 which is not adjacent to the protective film among the end surfaces 2a. For example, it is easy to generate|occur|produce a crack starting with the curve of a roughness curve (that is, the deep recessed part in the side part 2as). However, even when the protective film is not overlapped on the surface of the polarizer 2 on the second side S2 side, in the side portion 2as located on the second side S2 side without the protective film 3 , By reducing Rq, the various factors of cracks as described above are easily reduced, and crack generation of the polarizer 2 accompanying a temperature change is easily suppressed. That is, when Rq in the side portion 2as located on the second side S2 side without the protective film 3 is small, cracks occur in the side portion 2as located on the second side S2 side. This is easy to suppress. For example, when root mean square roughness Rq is 0.03-0.15 micrometers, it is easy to suppress the crack generation in the side part 2as located at the 2nd side S2 side. When the end face of the polarizer or the polarizing plate is not polished, since the end face of the polarizer is not roughened by polishing, the root mean square roughness Rq is approximately zero, and cracks are unlikely to occur in the end face of the polarizer. However, if the end face of the polarizer or the polarizing plate is not polished, it is difficult to adjust the dimensions of the polarizer or the polarizing plate to a desired value (eg, the range of tolerances in product specifications) with high precision. Accordingly, the dimensional accuracy of a polarizer having a root mean square roughness Rq of less than 0.03 μm tends to be lower than that of a polarizer having a root mean square roughness Rq of 0.03 μm or more.

The rectangular polarizer 2 has four end faces 2a. 0.03-0.15 micrometers may be sufficient as the root mean square roughness Rq in the side part 2as of some end surfaces 2a among the some end surfaces 2a which the polarizer 2 has. 0.03-0.15 micrometers may be sufficient as the root mean square roughness Rq in the side part 2as of all the end surfaces 2a which the polarizer 2 has. The crack generation in the second side S2 side of the polarizer 2 is more easily suppressed, so that there are many end surfaces 2a which have the side parts 2as whose Rq is 0.03-0.15 micrometers.

The resin constituting the polarizer 2 may be, for example, a polyvinyl alcohol-based resin, a polyvinyl acetate resin, an ethylene/vinyl acetate copolymer resin (EVA) resin, a polyamide resin, or a polyester-based resin. The polarizer 2 may be extended in a uniaxial direction or a biaxial direction. The polarizer 2 may be dyed with iodine or a dichroic dye. The polarizer 2 after dyeing|staining may be processed with boric acid. The polarizer 2 may be a polyvinyl alcohol film in which iodine is adsorbed and oriented.

The thickness of the polarizer 2 may be 2-30 micrometers, 2-15 micrometers, or 2-10 micrometers, for example. In general, cracks are more likely to occur in the polarizer as the thickness of the polarizer decreases. However, in the polarizing plate 1 provided with the polarizer 2 which concerns on this embodiment, even when the thickness of the polarizer 2 is 10 micrometers or less, the crack in the polarizer 2 can be suppressed suitably.

The protective film 3 is, for example, 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) resins) or polyester resins (such as polyethylene terephthalate resins).

The thickness of the protective film 3 may be 5-90 micrometers, 5-80 micrometers, or 5-50 micrometers.

The protective film 3 may be bonded to the surface of the polarizer 2 via an adhesive layer. You may form a protective film directly on the surface of the polarizer 2 by apply|coating the solution of resin which comprises the protective film 3 on the polarizer 2, forming a coating film, and drying a coating film.

The resin constituting the adhesive layer may be, for example, 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, thermal radical polymerization initiator, etc.) or other additives (sensitizer, etc.) may be added to the epoxy resin. The resin constituting the adhesive layer may be, for example, an acrylic resin such as acrylamide, acrylate, urethane acrylate or epoxy acrylate. A water-based adhesive containing a polyvinyl alcohol-based resin may be used for the adhesive layer.

The resin constituting the pressure-sensitive adhesive layer 5 may be, for example, an acrylic resin, a silicone resin, polyester, polyurethane, or polyether. The pressure sensitive adhesive layer 5 may be formed by apply|coating the solution containing these resin and arbitrary additive components to the surface of the polarizer 2, forming a coating film, and drying a coating film.

The thickness of the pressure-sensitive adhesive layer 5 may be, for example, 2 to 500 µm, 2 to 200 µm, or 2 to 50 µm.

You may transfer the pressure-sensitive adhesive layer 5 formed on the separator to the surface of the polarizer 2 . The separator is affixed to an optical film other than the polarizer 2 for the purpose of protecting the pressure-sensitive adhesive layer or preventing adhesion of foreign substances. A separator is a peelable film. For example, when the polarizing plate 1 is adhered to an image display element, the separator is peeled off to expose the pressure-sensitive adhesive layer. A separator may be used temporarily in the manufacturing process of the polarizing plate 1, and may peel from the polarizing plate 1 after that. The resin constituting the separator may be, for example, a polyethylene-based resin, a polypropylene-based resin, or a polyester-based resin (such as polyethylene terephthalate).

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

The reflective polarizer 4 (second optical film) may be a multilayer film made of, for example, polycarbonate or the like. The thickness of the reflective polarizer 4 may be, for example, 15 to 200 µm.

The thickness of the whole polarizing plate 1 may be 10-500 micrometers, 10-300 micrometers, or 10-200 micrometers, for example.

[Cutting of the polarizing plate end]

By cutting the end of the polarizing plate 1 described below, the average height Rc of the roughness curve elements on the end face 2a of the polarizer 2 included in the polarizing plate 1 is reduced to 0.05 to 1.7 μm. can be controlled within range. In addition, by the cutting process demonstrated below, the root mean square roughness Rq in the side part 2as of the end surface 2a of the polarizer 2 with which the polarizing plate 1 is equipped is the range of 0.03-0.15 micrometers. can be controlled by Hereinafter, the cutting process will be described in detail with reference to FIGS. 2 to 5 .

First, a plurality of polarizing plates 1A having the same laminated structure as the polarizing plate 1 according to the present embodiment are produced. Each polarizing plate 1A is the same as that of the polarizing plate 1 according to the present embodiment, except that the end face thereof is not cut. Since the end face 2a of 1 A of uncut polarizing plates is not roughened, Rc of the end face 2a of the polarizer 2 with which each polarizing plate 1A is equipped is less than 0.05. Moreover, Rq in the side part 2as of the end surface 2a of each polarizing plate 1A which is not cut is less than 0.03. 4 and 5 , a plurality of polarizing plates 1A are stacked to form a laminate 100 . The dimension of each polarizing plate 1A is completely the same, and in the laminated body 100, the whole surface of each polarizing plate 1A mutually completely overlaps. The end face 100a of the layered product 100 shown in FIG. 4 is a face including the end face of the polarizer 2 . That is, in the end surface 100a of the laminated body 100, the end surface of the polarizer 2 with which each polarizing plate 1A is equipped is aligned. As shown in FIG. 4 , the end face 100a of the laminate 100 (that is, the end face of the polarizer 2 ) faces the cutting face S of the cutting tool 10 , and the cutting face S ) on the cutting edge. For convenience of illustration, the laminate 100 is composed of four polarizing plates 1A, but the number of the polarizing plates 1A constituting the laminate 100 is not particularly limited.

As shown in FIG. 2 , the cutting tool 10 is fixed to a support body 10a (arbor). The cutting tool 10 rotates about an axis of rotation A. The number of revolutions (rotational speed) of the cutting tool 10 is freely adjusted. Also, as shown in FIGS. 2 to 5 , the cutting tool 10 has a disk shape. The rotation axis A of the cutting tool 10 is orthogonal to the end face 100a of the laminated body 100 to be cut (that is, the end face of each polarizer 2 ). When the time that the laminate 100 moves by 1 mm in the horizontal direction is regarded as a unit time, the number of revolutions of the cutting tool 10 per unit time is a roughness curve on the end face 2a of the polarizer 2 . Affects the average height (Rc) of an element. Moreover, the rotation speed of the cutting tool 10 per unit time also affects the root mean square roughness Rq in the side part 2as of the end surface 2a of the polarizer 2 . The number of revolutions of the cutting tool 10 per unit time may be, for example, 3.5 to 14 or 5.6 to 10.2. When the rotation speed of the cutting tool 10 is in these ranges, the average height Rc of the roughness curve element in the end surface 2a of the polarizer 2 is easy to be controlled to 0.05-1.7 micrometers. Moreover, when the rotation speed of the cutting tool 10 is in an above-mentioned range, the root mean square roughness Rq in the side part 2as of the end surface 2a of the polarizer 2 is easy to be controlled to 0.03-0.15.

The cutting tool 10 has a cutting surface S perpendicular to the rotation axis A. Accordingly, the cutting surface S is parallel to the end surface 100a of the laminate 100 to be cut. In other words, the cutting surface S is parallel to the end surface 2a of the polarizer 2 to be cut. 2 and 3 , on the cutting surface S, a first group of cutting portions composed of cutting portions 11a, 11b, and 11c, and a second group of cutting portions including cutting portions 11d, 11e and 11f A cutting group is formed. Each cutting section has a cutting edge (B) for chamfering the end face. Each of the cutting portions is arranged at approximately equal intervals around the rotation axis A. Each cutting portion protrudes from the cutting surface S toward the end surface 100a of the laminate 100 to be cut. The cutting edge B is disposed on the protruding top surface of each cutting part. The cutting edge (B) of each cutting part is arranged to extend parallel to the cutting surface (S). In other words, the cutting edge B which each cutting part has is arrange|positioned so that it may extend in parallel with respect to the end surface 2a of each polarizer 2 in the laminated body 100. As shown in FIG. In addition, although each cutting part formed in the cutting surface S of the cutting tool 10 is abbreviate|omitted in FIGS. 4 and 5 for convenience of illustration, all of the cutting tools 10 shown in FIGS. 2-5 are the same .

When the cutting tool 10 is rotated in the rotational direction (in the direction of the arrow in FIGS. 2 to 5 ), the cutting portions 11a , 11b and 11c come into contact with the end face 100a of the laminate 100 in this order. Thus, the end face 100a (end face 2a of each polarizer 2) is cut. The distance from the cutting surface S to the cutting edge B of the cutting portion 11a is smaller than the distance from the cutting surface S to the cutting edge B of the cutting portion 11b. The distance from the cutting surface S to the cutting edge B of the cutting portion 11b is smaller than the distance from the cutting surface S to the cutting edge B of the cutting portion 11c. That is, the protrusion height of the cutting edge B of the cutting part 11b is higher than the protrusion height of the cutting edge B of the cutting part 11a, and the protrusion height of the cutting edge B of the cutting part 11c is higher than the protrusion height of the cutting edge B of the cutting part 11a. The cutting edge B of 11b) is higher than the protrusion height.

When the cutting tool 10 is rotated in the rotational direction, the cutting portions 11d, 11e and 11f come into contact with the end face 100a of the laminate 100 in this order, and the end face 100a (each The end face 2a of the polarizer 2) is cut. The distance from the cutting surface S to the cutting edge B of the cutting portion 11d is smaller than the distance from the cutting surface S to the cutting edge B of the cutting portion 11e. The distance from the cutting surface S to the cutting edge B of the cutting portion 11e is smaller than the distance from the cutting surface S to the cutting edge B of the cutting portion 11f. That is, the protrusion height of the cutting edge B of the cutting part 11e is higher than the protrusion height of the cutting edge B of the cutting part 11d, and the protrusion height of the cutting edge B of the cutting part 11f is higher than the protrusion height of the cutting edge B of the cutting part 11d. The cutting edge B of 11e) is higher than the protrusion height.

As shown in Fig. 3, the distance from the rotation axis A to the cutting edge B of the cutting portion 11b is greater than the distance from the rotation axis A to the cutting edge B of the cutting portion 11a. short. The distance from the rotation axis A to the cutting edge B of the cutting portion 11c is shorter than the distance from the rotation axis A to the cutting edge B of the cutting portion 11b. The distance from the rotation axis A to the cutting edge B of the cutting portion 11e is shorter than the distance from the rotation axis A to the cutting edge B of the cutting portion 11d. The distance from the rotation axis A to the cutting edge B of the cutting part 11f is shorter than the distance to the cutting edge B of the cutting part 11e.

The cutting portions 11a, 11b, 11d, 11e are for rough cut, and these cutting edges B are made of, for example, polycrystalline diamond. The cutting portions 11c and 11f positioned at the rearmost in each cutting portion group are for finishing, and these cutting edges B are made of, for example, single crystal diamond. However, the material of each cutting edge B is not limited.

The circle drawn by each cutting part by the rotation of the cutting tool 10 intersects substantially perpendicularly to the surface of each polarizer 2 in the laminate 100 (the surface of each polarizer 2 facing the Z-axis direction) desirable. For example, a circle drawn by each cutting edge B of the cutting portions 11c and 11f having the shortest distance from the rotation axis A intersects the surface of each polarizer 2 in the stacked body 100 almost perpendicularly. It is preferable to do In other words, as shown in FIG. 5 , it is preferable that the approach angle θ of each cutting edge B with respect to the surface of each polarizer 2 is closer to 90°. That is, it is preferable that the approach angle θ of each cutting edge B with respect to the surface of the laminate 100 facing the Z-axis direction is closer to 90°. For example, it is preferable that the approach angle θ of each cutting edge B of the cutting portions 11c and 11f having the shortest distance from the rotation axis A be closer to 90°. In order to make the approach angle θ close to 90°, it is preferable that the diameter of the cutting surface S of the cutting tool 10 is larger than the thickness of the laminate 100 . In addition, it is preferable that the diameter of the cutting surface S of the cutting tool 10 is a size sufficient enough to be able to cut each end surface of all the overlapping polarizing plates 1A collectively and uniformly. 4 and 5 , the height at which the laminate 100 is disposed is preferably approximately equal to the height of the rotation axis A of the cutting tool 10 . In other words, the position of the laminate 100 in the direction parallel to the end face 2a of each polarizer 2 (Z-axis direction) is the rotation axis A of the cutting tool 10 in the same direction. ) is preferably approximately equal to the position of In other words, the position of the laminate 100 in the direction parallel to the end face 100a of the laminate 100 is substantially the same as the position of the rotation axis A of the cutting tool 10 in the same direction. The same is preferable. The thickness of the laminate 100 may be adjusted for the purpose of adjusting the angle of entry θ of the cutting edge B. In other words, you may adjust the number of 1A of polarizing plates which comprise the laminated body 100 for the purpose of adjustment of the approach angle (theta) of the cutting edge B. As the thickness of the laminate 100 decreases compared to the diameter of the cutting tool 10 , the angle of entry θ of the cutting edge B approaches 90°. The thickness of the laminate 100 may be adjusted for the purpose of adjusting the relative positional relationship between the laminate 100 and the rotation axis A of the cutting tool 10 . In other words, even if the number of polarizing plates 1A constituting the laminate 100 is adjusted for the purpose of adjusting the relative positional relationship between the laminate 100 and the rotation axis A of the cutting tool 10 good night. As described above, the entry angle θ of each cutting edge B is adjusted approximately vertically, the position of the laminate 100 is aligned with the position of the rotation axis A of the cutting tool 10, and the cutting tool ( 10) to control the average height Rc of the roughness curve element on the end face 2a of the polarizer 2 included in the polarizing plate 1 within the range of 0.05 to 1.7 μm by appropriately adjusting the number of rotations 10) easy. In addition, the entry angle θ of each cutting edge B is adjusted approximately vertically, the position of the laminate 100 is aligned with the position of the rotation axis A of the cutting tool 10, and the cutting tool 10 By adjusting the rotation speed of , it is easy to control the root mean square roughness Rq in the side part 2as of the polarizer 2 with which the polarizing plate 1 is equipped in the range of 0.03-0.15 micrometers. The number of revolutions of the cutting tool 10 required to control each of Rc and Rq within the above-described range can be grasped by a preliminary experiment. In order to adjust the relative positional relationship between the stacked body 100 and the rotation axis A of the cutting tool 10, an end face 100a of the stacked body 100 (end face 2a of each polarizer 2) ), the cutting tool 10 may move freely. For example, you may adjust the position of the cutting tool 10 freely in the Z-axis direction (up-down direction). In this case, the position of the laminate 100 in the Z-axis direction may be fixed. The laminated body 100 may move freely in the direction parallel to the end surface 100a of the laminated body 100 (the end surface 2a of each polarizer 2). For example, you may adjust the position of the laminated body 100 freely in the Z-axis direction (for example, up-down direction). In this case, the position of the cutting tool 10 in the Z-axis direction may be fixed.

In each polarizing plate 1A which comprises the laminated body 100 WHEREIN: It is preferable that the polarizer 2 is located above the protective film 3 . Moreover, it is preferable that the elasticity modulus of the protective film 3 is higher than the elasticity modulus of the polarizer 2 . 2 to 5 , each cutting edge B of the cutting tool 10 moves from the upper side to the lower side of the laminate 100 . Accordingly, when the polarizer 2 is positioned above the protective film 3 , each cutting edge B first contacts the polarizer 2 and then the protective film 3 . In other words, each cutting edge B enters from the polarizer 2 with a low elastic modulus, and then enters into the protective film 3 with a high elastic modulus. When disposing the polarizer 2 and the protective film 3 in this way, it is easy to control the average height Rc of the roughness curve element on the end face 2a of the polarizer 2 within the range of 0.05 to 1.7 µm. , It is easy to control the root mean square roughness Rq in the side part 2as of the polarizer 2 within the range of 0.03-0.15 micrometers.

You may move the rotating cutting tool 10 at a constant speed in the direction parallel to the end surface 100a of the laminated body 100 (Y direction). As the cutting tool 10 moves, the end face 100a of the laminate 100 (the end face 2a of each polarizer 2) is gradually cut. In this case, the position of the laminate 100 may be fixed. In the direction (Y direction) parallel to the end surface 100a of the laminated body 100, you may make the laminated body 100 approach the cutting tool 10 at a constant speed. As the laminated body 100 moves, the end face 100a of the laminated body 100 (the end face 2a of each polarizer 2) is gradually cut. In this case, the position of the cutting tool 10 may be fixed.

According to the above-mentioned cutting method, compared with cutting|disconnection of the laminated body 100 by the conventional laser, it is possible to adjust the dimension of each polarizing plate 1A which comprises the laminated body 100 with high precision.

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

For example, the polarizing plate includes a polarizer, a first optical film (eg, protective film) superposed on the polarizer, a pressure-sensitive adhesive layer superposed on the first optical film, and a second optical film (eg, reflective polarizer) superposed on the pressure-sensitive adhesive layer. ) may be provided.

The first optical film or the second optical film is a film having an anti-glare function, a film having a surface antireflection function, a reflective film, a transflective film, a viewing angle compensation film, a release film, an optical compensation layer, a touch sensor layer, an antistatic layer Or an antifouling layer may be sufficient. Of course, a reflection type polarizer may be sufficient as a 1st optical film, and a protective film may be sufficient as a 2nd optical film.

[Example]

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

[Example 1]

(1) Preparation of polarizer

A polyvinyl alcohol film having a thickness of 20 µm was prepared. The average degree of polymerization of this polyvinyl alcohol film was about 2400, and the degree of saponification was 99.9 mol% or more.

The polyvinyl alcohol film was uniaxially stretched to about 4 times by dry method. The polyvinyl alcohol film was immersed in pure water at 40°C for 1 minute while maintaining the full length state of the polyvinyl alcohol film by stretching. Next, the polyvinyl alcohol film was immersed in the 1st dyeing solution (aqueous solution) for 60 second. The temperature of the 1st dyeing solution was adjusted to 28 degreeC. The mass ratio of iodine:potassium iodide:water in the first dyeing solution was 0.1:5:100. Next, the polyvinyl alcohol film was immersed in the 2nd dyeing solution (aqueous solution) for 300 second. The temperature of the 2nd dyeing liquid was adjusted to 68 degreeC. The mass ratio of potassium iodide:boric acid:water in the second dyeing solution was 10.5:7.5:100. Next, the polyvinyl alcohol film was washed with pure water for 5 seconds. The temperature of the pure water was adjusted to 5 degreeC. The polyvinyl alcohol film after washing|cleaning was dried at 70 degreeC for 180 second. By the above procedure, the polarizer which is a long strip|belt-shaped film was obtained. In the polarizer, the iodine was adsorbed and oriented to the uniaxially stretched polyvinyl alcohol film. The thickness of the polarizer was 7 µm.

(2) Preparation of water-based adhesive

Polyvinyl alcohol powder was melt|dissolved in 95 degreeC hot water, and the polyvinyl alcohol aqueous solution was prepared. The density|concentration of the polyvinyl alcohol in aqueous solution was adjusted to 3 mass %. As polyvinyl alcohol powder, "KL-318" manufactured by a corporation was used. The average degree of polymerization of the polyvinyl alcohol powder was 1800. A water-based adhesive was obtained by mixing a crosslinking agent with an aqueous polyvinyl alcohol solution. As a crosslinking agent, "Sumirez Resin 650" manufactured by Daoka Chemical Industries, Ltd. was used. The mass of the crosslinking agent added to the polyvinyl alcohol aqueous solution was adjusted to 1 mass part with respect to 2 mass parts of polyvinyl alcohol powders.

(3) Preparation of one-side protection polarizing plate

Said polarizer was conveyed continuously in the long direction. Simultaneously with conveyance of a polarizer, the protective film was continuously sent out from a roll body, and corona-treated with respect to a protective film, conveying a protective film. As a protective film, the Nippon Zeon Corporation Zeonoa film "ZF14-023" was used. The thickness of the protective film was 23 µm. Simultaneously with conveyance of a polarizer and a protective film, the peeling film was sent out continuously from a roll body, and the peeling film was conveyed. As a peeling film, "KC8UX2MW" which is a Konica Minolta Opt Co., Ltd. product triacetyl cellulose film (TAC film) was used. The thickness of the release film was 80 µm. The release film was not subjected to a saponification treatment.

Next, the above-mentioned aqueous adhesive was interposed between a polarizer and a protective film, pure water was interposed between a polarizer and a peeling film, and laminated|multilayer film was obtained by pinching|interposing these with a pair of bonding rolls. This laminated film is a polarizer, an aqueous adhesive layer superposed on one surface of the polarizer, a protective film superposed on the aqueous adhesive layer, a pure layer superposed on the other surface of the polarizer, and peeling superposed on the pure layer It was to have a film. This laminated|multilayer film was conveyed to a drying apparatus, while drying the water-based adhesive layer, the pure layer was volatilized and removed. The temperature in the drying apparatus was adjusted to 80 degreeC. The drying time was 300 seconds. The single-sided protection polarizing plate was obtained by peeling a peeling film from the laminated body after drying. This single-sided protective polarizing plate was equipped with a polarizer, the dry water-system adhesive bond layer superposed on one surface of a polarizer, and the protective film superposed|stacked on the water-system adhesive bond layer.

(4) Fabrication of a polarizing plate with a brightness enhancing film

On the surface of the polarizer with which said one-side protection polarizing plate is equipped, the brightness improving film was bonded through a pressure-sensitive adhesive layer, and the polarizing plate with a brightness improving film was obtained. When bonding, the direction of each of a single-sided protection polarizing plate and a brightness improvement film was adjusted so that the extending|stretching direction of a polarizer might become parallel to the extending|stretching axis of a brightness improvement film. An acrylic resin was used for the pressure-sensitive adhesive layer. As the brightness improving film, "APF", which is a reflective polarizer manufactured by 3M Corporation, was used.

(5) Preparation of a polarizing plate with a separator

A film-type separator covered with a pressure-sensitive adhesive layer was prepared. An acrylic resin was used for the pressure-sensitive adhesive layer. A separator was attached to the surface of the brightness enhancement film provided with the polarizing plate having the above-described brightness enhancement film through a pressure-sensitive adhesive layer to obtain a polarizing plate with a separator.

A polarizing plate with a separator includes a polarizer, a water-based adhesive layer superposed on one surface of the polarizer, a protective film (first optical film) superposed on the water-based adhesive layer, and a first pressure-sensitive adhesive layer superposed on the other surface of the polarizer A pressure-sensitive adhesive layer, a brightness enhancing film (second optical film) superposed on the first pressure-sensitive adhesive layer, a second pressure-sensitive adhesive layer superposed on the brightness enhancing film, and a separator superposed on the second pressure-sensitive adhesive layer was provided.

(6) Machining

The polarizing plate having the above-described separator was cut to a size of 120 mm x 70 mm to obtain 100 polarizing plates. A super cutter was used for cutting. The structure, composition, and dimensions of 100 polarizing plates were the same. The laminate was obtained by aligning all directions of 100 sheets of polarizing plates, and overlapping 100 sheets of polarizing plates. Hereinafter, for convenience of explanation, a laminate including 100 polarizing plates is the same as the laminate 100 illustrated in FIGS. 4 and 5 . The four end faces 100a of the laminate 100 were cut using a cutting tool. The cutting method of the four end surfaces 100a was exactly the same. The cutting tool used in the Example was the same as the cutting tool 10 shown in Figs. 2 to 5, except that each of the first and second cutting groups had five cutting units. Hereinafter, for convenience of description, the cutting tool used in the embodiment is the same as the cutting tool 10 shown in FIGS. 2 to 5 . Hereinafter, in each drawing, the Z-axis direction is regarded as an upward direction, and the X-axis direction and the Y-axis direction are regarded as horizontal directions. When forming the laminated body 100, in each polarizing plate 1A, 100 sheets of polarizing plates 1A were piled up so that the polarizer 2 might be located on the protective film 3.

In the direction opposite to the rotation of the cutting tool 10 , the five cutting edges B of each group of the cutting portions were arranged on the cutting surface S so that the protruding heights of the five cutting edges B gradually increased. In addition, along the direction opposite to the rotational direction of the cutting tool 10 , the five cutting portions of each cutting portion group are on the cutting surface S so that the distance from the rotational axis A to the cutting edge B of the cutting portion gradually decreases. was placed A total of ten cutting portions constituting the first and second cutting portion groups were arranged at equal intervals so as to surround the rotation axis A. The height of a pair of cutting edges (B) opposed through the axis of rotation (A) was the same. The distance between the cutting edge B and the rotation axis A of a pair of cutting portions opposing through the rotation axis A was the same. Since each group of cutting edges of the cutting tool 10 has five cutting edges B having different heights, one rotation of the cutting tool 10 corresponds to cutting in five different depths.

A pair of cutting tools 10 were used in the cutting process of the end surface 100a of the laminated body 100 . The cutting surfaces S of the pair of cutting tools 10 were made to face each other. The space|interval of a pair of cutting tools 10 was adjusted so that the laminated body 100 might fit between a pair of cutting tools 10. As shown in FIG. The direction of the cutting tool 10 was adjusted so that the rotation axis A of the cutting tool 10 might become horizontal. The position of each cutting tool 10 was fixed, and each cutting tool 10 was rotated about the rotation axis A. As shown in FIG. The direction of the end surface 100a of the laminate 100 is so that the end surface 100a of the laminate 100 is perpendicular to the rotation axis A (normal to the cutting surface S) of the cutting tool 10 . Adjusted. Moreover, the direction of the laminated body 100 was adjusted so that the surface of the laminated body 100 might become horizontal.

A synthetic resin plate having the same thickness as the laminate 100 and one step smaller than the laminate 100 was placed under the laminate 100 to adjust the height at which the laminate 100 is arranged. As shown in FIGS. 4 and 5 , by adjusting the height at which the laminate 100 is disposed, the angle of entry of each cutting edge B with respect to the surface of each polarizer 2 in the laminate 100 ( θ) becomes substantially perpendicular, and the height at which the laminate 100 is disposed is approximately equal to the height of the rotation axis A of the cutting tool 10 . The thickness of the synthetic resin plate used to adjust the height at which the laminate 100 is disposed was 60 mm.

In the cutting process, the height at which the laminate 100 is arranged was kept constant. In the cutting process, the laminated body 100 was moved at a constant speed in the horizontal direction (Y-axis direction), and the laminated body 100 was gradually introduced between the pair of rotating cutting tools 10 . That is, one end surface 100a of the laminated body 100 is gradually cut by the cutting surface S of one cutting tool 10 , while the cutting surface S of the other cutting tool 10 is cut. ), the other end surface 100a of the laminate 100 was gradually cut. The laminate 100 was continuously moved in the horizontal direction (Y-axis direction) until the entire end surface 100a of the laminate 100 was cut.

In each polarizing plate 1, since the polarizer 2 was arrange|positioned on the protective film 3, in one rotation of the cutting tool 10, each cutting edge B of the cutting tool 10 is prioritized by the laminated body. In (100), the end face of each polarizer 2 was cut, and then the end face of each protective film 3 adjacent to each polarizer 2 was cut.

When the time for the laminate 100 to move 1 mm in the horizontal direction was regarded as a unit time, the number of revolutions of the cutting tool 10 per unit time was adjusted to 10.2 times.

100 sheets of polarizing plates (polarizing plate of Example 1) were obtained by the above process.

(7-1) Measurement of average height (Rc) of roughness curve elements

The average height Rc of the roughness curve element in the end surface 2a of the polarizer 2 with which the polarizing plate 1 of Example 1 is equipped with the following procedure was measured. The end surface 2a of the polarizer 2 which is a measurement object means the end surface to which the cutting by the cutting tool 10 was performed. The 3D measurement laser microscope "OLS4100" by the Olympus Corporation was used for the measurement of Rc. Five polarizing plates 1 were taken out at random from 100 polarizing plates of Example 1. Among the four end faces of the polarizer 2 included in one polarizing plate 1, Rc of two end faces 2a perpendicular to the direction of the stretching axis of the polarizer 2 is measured, and the two end faces ( The average value of Rc in 2a) was calculated. By the same method, the average value of Rc of each polarizer 2 with which the polarizing plate 1 of 5 sheets is equipped was computed, and the average value of these five Rc was also averaged. Rc of Example 1 calculated by the above procedure was 0.07 µm.

(7-2) Measurement of Root Mean Square Roughness (Rq)

In the following procedure, the root mean square roughness Rq in the side part 2as of the end surface 2a of the polarizer 2 with which the polarizing plate 1 of Example 1 is equipped was measured. The end surface 2a of the polarizer 2 which is a measurement object means the end surface to which the cutting by the cutting tool 10 was performed. The 3D measurement laser microscope "OLS4100" by the Olympus Corporation was used for the measurement of Rq. Five polarizing plates 1 were taken out at random from 100 polarizing plates of Example 1. Among the four end faces of the polarizer 2 included in one polarizing plate 1, Rq of two end faces 2a perpendicular to the direction of the stretching axis of the polarizer 2 is measured, and the two end faces ( The average value of Rq of 2a) was computed. The average value of each Rq of the polarizer 2 with which the polarizing plate 1 of 5 sheets is equipped by the same method was computed, and the average value of these five Rqs was also averaged. Rq of Example 1 calculated in the above procedure was 0.031 µm.

(8) Heat shock test

The heat shock test using the polarizing plate (polarizing plate after cutting) of 1 sheet of Example 1 was done in the following procedure.

The separator was peeled from the polarizing plate with a separator, the polarizing plate was stuck to the alkali-free-glass plate through an adhesive layer, and the sample for a test was obtained. As an alkali free glass plate, "Eagle-XG" by the Corning company was used. The sample was imprisoned in an autoclave for 20 minutes, and the sample was pressurized. The temperature in the autoclave was maintained at 50°C. The pressure in the autoclave was maintained at 5 MPa. The sample after the pressure treatment was left to stand for one day in an atmosphere having a temperature of 23°C and a relative humidity of 60%.

The sample which passed through the above process was installed in the test tank of a cold-heat shock tester. Then, the cycle consisting of the following steps 1 to 3 was repeated 12 times. As a cold-and-heat shock tester, "TSA-301L-W" by Espec Corporation was used.

Step 1: Maintaining the temperature in the test bath at -40°C for 30 minutes.

Step 2: After step 1, for 5 minutes, maintaining the temperature in the test bath at 23°C.

Step 3: After step 2, for 30 minutes, maintaining the temperature in the test bath at 85°C.

After repeating the cycle 12 times, the samples were removed from the test bath. Next, the edge of the sample was observed with the optical microscope, and the presence or absence of the crack in the end surface 2a of the polarizer 2 was investigated. As an optical microscope, "VHX-5000" manufactured by Shakiens, Inc. was used. The number of cracks per unit length in the end surface 2a of the polarizer 2 was calculated|required. A "unit length" is a line segment in the end face of the polarizer, perpendicular to the thickness direction of the polarizer, and having a length of 10 mm. "The number of cracks per unit length" means the number of cracks intersecting with the unit length in the end surface of a polarizer. The number of cracks in Example 1 was zero.

(9) Evaluation of dimensional accuracy of polarizing plate

The length of one side of the polarizing plate of Example 1 was measured, and it was evaluated whether the measured value was within the tolerance range of the target value +/-50 micrometers. The measured value of the length of one side of the polarizing plate of Example 1 was within the tolerance range of the target value ±50 µm. That is, it was confirmed that the dimensional accuracy of the polarizing plate of Example 1 was high.

[Examples 2 to 9]

In Examples 2 to 9, the rotation speed of the cutting tool 10 per unit time was adjusted to the value shown in Table 1 below. In the cutting processing of Examples 5-7 and 9, the synthetic resin plate was not arrange|positioned under the laminated body 100. As shown in FIG. That is, in each of Examples 5-7 and 9 cutting, the height at which the laminated body 100 is arrange|positioned was low compared with the case of Example 1. Therefore, in each of Examples 5-7 and 9 cutting, the entry angle (theta) of each cutting edge B with respect to the surface of each polarizer 2 in the laminated body 100 was not perpendicular|vertical. In addition, in each of the cutting processes of Examples 5-7 and 9, the height at which the laminated body 100 is arrange|positioned was not substantially equal to the height of the rotation axis A of the cutting tool 10. As shown in FIG.

Except for the above related to cutting, each polarizing plate of Examples 2 to 9 was produced in the same manner as in Example 1. Rc and Rq of Examples 2 to 9 were measured in the same manner as in Example 1. Rc and Rq of Examples 2 to 9 are shown in Table 1 below. In the same manner as in Example 1, the number of cracks in Examples 2 to 9 was measured. When cracks were formed in the end face of the polarizer, the length of the cracks was also measured. The crack length is the distance from the end of the crack located on the end face of the polarizer to the end of the other crack. The number of cracks and the crack length of each of Examples 2 to 9 are shown in Table 1 below. The length of the crack shown in Table 1 is the length of the longest crack among the cracks formed in the end surface of each polarizer. The same method as Example 1 evaluated the dimensional accuracy of each polarizing plate of Examples 2-9. Examples 2 to 9 The dimensional accuracy of each polarizing plate is shown in Table 1 below.

[Comparative Example 1]

In the cutting process of Comparative Example 1, the synthetic resin plate was not disposed under the laminate 100 . That is, in the cutting process of the comparative example 1, the height at which the laminated body 100 is arrange|positioned was low compared with the case of Example 1. Therefore, in the cutting process of Comparative Example 1, the entry angle θ of each cutting edge B with respect to the surface of each polarizer 2 in the laminate 100 was not perpendicular. Moreover, in the cutting process of the comparative example 1, the height at which the laminated body 100 is arrange|positioned was not substantially equal to the height of the rotation axis A of the cutting tool 10. As shown in FIG. In addition, in the cutting process of Comparative Example 1, the rotation speed of the cutting tool 10 per unit time was adjusted to the value shown in Table 1 below.

A polarizing plate of Comparative Example 1 was manufactured in the same manner as in Example 1, except for the above related to cutting. Rc and Rq of Comparative Example 1 were measured in the same manner as in Example 1. Rc and Rq of Comparative Example 1 are shown in Table 1 below. The number of cracks and the crack length of Comparative Example 1 were measured in the same manner as in Examples 1 to 9. The number of cracks and the length of cracks in Comparative Example 1 are shown in Table 1 below. The dimensional accuracy of the polarizing plate of Comparative Example 1 was evaluated in the same manner as in Example 1. The dimensional accuracy of the polarizing plate of Comparative Example 1 is shown in Table 1 below.

[Comparative Example 2]

A polarizing plate of Comparative Example 2 was produced in the same manner as in Example 1 except that cutting was not performed. Rc and Rq of Comparative Example 2 were measured in the same manner as in Example 1. Rc and Rq of Comparative Example 2 are shown in Table 1 below. The number of cracks in Comparative Example 2 was measured in the same manner as in Example 1.

The number of cracks in Comparative Example 2 is shown in Table 1 below. In the same manner as in Example 1, the dimensional accuracy of the polarizing plate of Comparative Example 2 was evaluated. The measured value of the length of one side of the polarizing plate of Comparative Example 2 was out of the tolerance range of the target value ±50 µm. That is, it was confirmed that the dimensional accuracy of the polarizing plate of Comparative Example 2 was low.

The polarizing plate according to the present invention 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 by being adhered to, for example, a liquid crystal cell or an organic EL element.

1: polarizing plate, 2: film-type polarizer, 2a: end face of polarizer, 2as: side of end face (part along the second side of the end face), 3: protective film (first optical film), 4: reflection Type polarizer (second optical film), 5: pressure-sensitive adhesive layer, S1: first side, S2: second side, S3: third side, S4: fourth side.

Claims (5)

a film-type polarizer;
A first optical film superimposed on one surface of the polarizer is provided,
The thickness of the polarizer is 2-15 μm,
The polarizer is a stretched film containing a polyvinyl alcohol-based resin,
The polarizer is a polarizer in which a protective film is overlapped on one surface, and the protective film is the first optical film,
The first optical film includes at least one selected from the group consisting of a cellulose-based resin, a polyolefin-based resin, a cyclic olefin-based resin, an acrylic resin, and a polyester-based resin,
The average height (Rc) of the roughness curve element in the end face of the polarizer perpendicular to the direction of the stretching axis of the polarizer is 0.05 to 1.7 μm, and the end face of the polarizer is cut. a film-type polarizer;
A first optical film superimposed on one surface of the polarizer is provided,
The thickness of the polarizer is 2-15 μm,
The polarizer is a stretched film containing a polyvinyl alcohol-based resin,
The polarizer is a polarizer in which a protective film is overlapped only on one surface, and the protective film is the first optical film,
The first optical film includes at least one selected from the group consisting of a cellulose-based resin, a polyolefin-based resin, a cyclic olefin-based resin, an acrylic resin, and a polyester-based resin,
The average height (Rc) of the roughness curve element in the end face of the polarizer is 0.05 to 1.7 μm, and the end face of the polarizer is cut. The method according to claim 1 or 2, wherein a first side of the sides surrounding one end surface of the polarizer is adjacent to the first optical film, and a second side of the sides surrounding the end surface of the polarizer is the first side. A polarizing plate located opposite to the side and having a root mean square roughness (Rq) of 0.03 to 0.15 μm in a portion of the end surface along the second side. The polarizing plate according to claim 2, further comprising: an adhesive layer superposed on the other surface of the polarizer; and a second optical film superposed on the adhesive layer. The image display device containing the polarizing plate in any one of Claims 1, 2, and 4.

Images