KR20170098698A - Polarizing plate and image display device - Google Patents

Abstract

The present invention relates to a polarizing plate capable of suppressing light leakage. The polarizing plate (1) comprises: a film-type polarizer (7); and a plurality of optical films (3, 5, 9, 11, 13) overlapped with the polarizer (7). The verticality (a/b) of a hole (21) penetrating the polarizing plate (7) is equal to or more than 0.00 but less than 0.32. The width (W) of a depolarization portion (23) around the hole (21) is equal to or more than 0.00 micrometer but less than 32 micrometers.

Description

[0001] POLARIZING PLATE AND IMAGE DISPLAY DEVICE [0002]

The present invention relates to a polarizing plate and an image display apparatus.

The polarizing plate is one of optical components constituting an image display apparatus such as a liquid crystal television, an organic EL television or a smart phone. As shown in the following Patent Document 1, the polarizing plate has a film-type polarizer and an optical film (for example, a protective film) superimposed on the polarizer.

Patent Document 1: Japanese Patent Application Laid-Open No. 2002-303730

Since most conventional image display devices such as televisions or smart phones have a rectangular screen, the conventional polarizing plate mounted on the image display device is also rectangular and has a uniform polarizing function as a whole. On the other hand, a special image display device has a deformed shape in accordance with the use thereof, and the conventional polarizing plate mounted on the device is also a release. For example, in an image display device used for a smart watch or vehicle meter, there is a case that a hole for passing the rotation shaft of the pointer is formed. Therefore, it is necessary to form a through hole also in the polarizing plate mounted on the image display apparatus. Since the purpose and purpose of the polarizing plate are various, it is assumed that the through hole is formed in the polarizing plate depending on the purpose and purpose.

However, when a through hole is formed in a polarizing plate by a conventional mechanical method such as a press working (punching) using a punch and a die or a cutting with a drill, the through hole may be inclined, or cracks may be formed in the vicinity of the through hole Or may be formed. The inclination and cracking of the through hole impair the polarizing ability in the vicinity of the through hole and cause light leakage. The term " light leakage " is a phenomenon in which light whose vibration direction is parallel to the absorption axis of the polarizer passes through the polarizer.

When the through hole is formed in the polarizing plate by laser machining (for example, thermal processing) using a CO ₂ laser or the like instead of the above mechanical method, the through hole may be inclined or a crack may be formed in the vicinity of the through hole There is a case. Further, in the laser processing, since the portion where the through-hole is formed is heated by the laser, the polarization capability of the polarizer is likely to be impaired by the chemical alteration. Chemical alteration of the polarizer is, for example, discoloration or dissolution of the polarizer. Hereinafter, a portion in which the polarization function is impaired due to chemical alteration of the polarizer is referred to as a " depolarization portion " of the polarizer. The wider the depolarization portion, the more likely the light will leak in the image display apparatus. As a result of the studies by the present inventors, it has been found that the above-described technical problem accompanying the formation of the through holes can occur even in the case of processing using an excimer laser having a shorter wavelength than the CO ₂ laser (for example, ablation processing) .

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a polarizing plate capable of suppressing light leakage, and an image display apparatus including the polarizing plate.

A polarizing plate related to one aspect of the present invention includes a film-type polarizer and a plurality of optical films superimposed on the polarizer, wherein a vertical degree of a hole passing through the polarizing plate is 0.00 or more and less than 0.32, The width of the depolarization portion is 0.00 탆 or more and less than 32 탆. The "optical film" means a film-like member (excluding the polarizer itself) constituting the polarizing plate. For example, the optical film includes a protective film and a release film.

The number of cracks around the hole may be 0 or more and 3 or less per 1 mm of the unit length.

The length of the crack in the periphery of the hole may be 0 占 퐉 or more and less than 50 占 퐉.

At least one of the optical films of the pair of optical films sandwiching the polarizer may contain triacetylcellulose.

At least one of the optical films of the pair of optical films sandwiching the polarizer may include the cyclic olefin polymer.

At least one of the optical films of the pair of optical films sandwiching the polarizer may contain methyl polymethacrylate.

An image display apparatus according to one aspect of the present invention includes the polarizing plate.

According to the present invention, there is provided a polarizing plate capable of suppressing light leakage, and an image display apparatus including the polarizing plate.

1 is a perspective view of a polarizing plate according to an embodiment of the present invention.
2 is a schematic view of a surface (a cross section of a polarizing plate perpendicular to the surface of the polarizing plate) viewed from the direction of the arrow of the polarizing plate in the II-II line direction in Fig.
Fig. 3 is an enlarged view of a region III (around the hole penetrating the polarizing plate) in the surface of the polarizing plate in Fig. 1. Fig.
4 is a schematic diagram of a spot of an excimer laser and an intensity distribution of the excimer laser along a straight line passing through the center of the spot of the excimer laser.
5 is a schematic diagram of a cross section of an image display apparatus (liquid crystal display apparatus) according to an embodiment of the present invention.
6 (a) is a schematic side view showing the arrangement of a polarizing plate when inspecting light leakage in a polarizing plate, and Fig. 6 (b) is a schematic top view showing a layout of the arrangement shown in .

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the drawings, the same reference numerals are given to the same constituent elements. The present invention is not limited to the following embodiments. X, Y and Z shown in the drawings denote three coordinate axes perpendicular to each other. The directions indicated by the coordinate axes are common to all the drawings.

1, the polarizing plate 1 according to the present embodiment includes a film polarizer 7 and a plurality of optical films 3, 5, 9, and 13 superimposed on the polarizer 7 . Both the polarizer 7 and the plurality of optical films 3, 5, 9, and 13 are rectangular. The plurality of optical films 3, 5, 9, and 13 are the first protective film 5, the second protective film 9, the third protective film 3, and the release film 13 (separator). That is, the polarizing plate 1 includes a polarizer 7, a first protective film 5, a second protective film 9, a third protective film 3, and a release film 13. The polarizing plate 1 also has an adhesive layer 11 positioned between the second protective film 9 and the release film 13. The first protective film 5 is superimposed on one surface of the polarizer 7 and the second protective film 9 is superimposed on the other surface of the polarizer 7. The third protective film (3) is superposed on the first protective film (5). That is, the first protective film 5 is positioned between the polarizer 7 and the third protective film 3. The release film 13 is superimposed on the second protective film 9 through the adhesive layer 11. In other words, the second protective film 9 is located between the polarizer 7 and the adhesive layer 11.

One surface (first surface) of the polarizing plate 1 is composed of the third protective film 3. The other surface (second surface) of the polarizing plate 1 is composed of a release film 13. The cross section of the polarizer 1 shown in Fig. 2 is perpendicular to the polarizer 7 and each optical film 3, 5, 9, 13. In other words, the cross section of the polarizing plate 1 shown in Fig. 2 is perpendicular to the Y axis and parallel to the ZX plane. In other words, the cross section of the polarizer 1 shown in Fig. 2 is perpendicular to the light-receiving surface of the polarizer 1.

In the polarizing plate 1, a hole (through hole 21) penetrating the polarizing plate 1 is formed. The through hole 21 is formed in a direction substantially perpendicular to the surface (XY plane) of the polarizing plate 1 and in the stacking direction (Z-axis direction) of the polarizer 7 and the plurality of optical films 3, 5, 9, It is parallel. The shape of the through hole 21 in the direction parallel to the surface of the polarizing plate 1 (in the XY plane direction) is, for example, a circle as shown in Fig. The inner wall of the through hole 21 may not be smooth.

The vertical degree of the through hole 21 is 0.00 or more and less than 0.32. Hereinafter, a vertical view will be described with reference to Fig.

The cross section of the polarizing plate 1 shown in Fig. 2 is perpendicular to the surface of the polarizing plate 1, and also includes the central axis of the circular through hole 21. Fig. The end portion of the first optical film (for example, the third protective film 3), which is located on one surface (first surface) of the polarizing plate 1 and corresponds to the edge of the through hole 21, (3e). The end portion of the second optical film (for example, the release film 13), which is located on the other surface (second surface) of the polarizing plate 1 and corresponds to the edge of the through hole 21, 13e). Both the first end 3e and the second end 13e are located on the same cross section perpendicular to the surface of the polarizing plate 1. [ The distance between the first end portion 3e and the second end portion 13e in a direction parallel to the surface of the polarizing plate 1 (XY plane direction) is defined as a. The thickness (for example, the average value of the thickness) of the polarizing plate 1 is defined as b. Verticality is defined as a / b. The vertical degree may be defined as a '/ b. a 'is a distance between the first end portion 3e' and the second end portion 13e 'in a direction parallel to the surface of the polarizing plate 1. The first end 3e 'is a separate first end located opposite the first end 3e. The second end 13e 'is a separate second end located opposite the second end 13e. a / b may be the same as a '/ b. a / b may be different from a '/ b. When a / b is different from a '/ b, both a / b and a' / b are between 0.00 and less than 0.32. A and b may be measured on an arbitrary section of the polarizing plate 1 as long as the above definition is satisfied, and a / b may be calculated from the measured values of each of a and b. When calculating the vertical degree (a / b) in any of plural cross-sections of the polarizing plate 1, the maximum value among the plurality of calculated vertical degrees a / b may be 0.00 or more and less than 0.32. a, a ', b, and b' may be measured based on, for example, observation of the cross section of the polarizing plate 1 using an optical microscope.

When the verticality (a / b) of the through hole 21 is less than 0.32, light leakage is suppressed. When the vertical degree a / b of the through hole 21 is 0.32 or more, light leakage due to light refraction or the like becomes conspicuous at the end face (end face) of the polarizer 7 exposed in the through hole 21. The vertical degree (a / b) of the through hole 21 may be 0.00 to 0.30, 0.00 to 0.28, 0.00 to 0.27, 0.05 to 0.30, 0.05 to 0.28, or 0.05 to 0.27. The smaller the vertical degree (a / b), the more likely the light leakage is suppressed. Therefore, a is most preferably zero. That is, the vertical degree (a / b) is most preferably zero. The vertical degree a / b is zero means that the through hole 21 is completely perpendicular to the surface of the polarizing plate 1 (the first surface and the second surface).

The thickness b of the polarizing plate 1 may be, for example, 10 μm or more and 1200 μm or less, 10 μm or more and 500 μm or less, 10 μm or more and 300 μm or less, or 10 μm or more and 200 μm or less. The distance (a or a ') between the first end and the second end may be any value as long as a / b is 0.00 or more and less than 0.32.

When the openings at both ends of the through hole 21 are a pair of concentric circles, the vertical degree may be defined as follows. The inside diameter (diameter) of one end (opening) of the through hole 21 is defined as d1. The inside diameter (diameter) of the other end (opening) of the through hole 21 is defined as d2. At this time, the vertical degree of the through hole 21 may be defined as the absolute value of (d1-d2) / 2b. This definition is not inconsistent with the above definition (a / b). That is, the absolute value of (d1-d2) / 2 is the same as a or a '. d1 and d2 may be measured based on, for example, observation of both surfaces of the polarizing plate 1 using an optical microscope.

There may be a case where the polarization canceling section 23 is formed around the through hole 21. [ The polarization canceling section 23 is formed by chemical alteration of the optical films 3, 5, 9, 13 superimposed on the polarizer 7 or the polarizer 7 in the process of forming the through hole 21. [ The polarization canceling section 23 may be formed along the first surface (for example, the surface of the third protective film 3). The polarization canceling section 23 may be formed along the second surface (for example, the surface of the release film 13) on the back surface of the first surface. The polarization canceling section 23 may be present continuously or discontinuously in a direction perpendicular to the surface of the polarizing plate 1 (Z-axis direction). That is, the polarization canceling section 23 may have a depth from the surface of the polarizing plate 1. In other words, the polarization canceling section 23 may be three-dimensionally distributed. For example, the polarization canceling section 23 may be a tubular portion that surrounds the entire through-hole 21. The polarization canceling section 23 is a factor of light leakage. The light leakage in the polarization canceling section 23 is caused by a change in the chemical composition of the optical films 3, 5, 9, and 13 superimposed on the polarizer 7 or the polarizer 7. For example, light leakage in the polarization canceling section 23 occurs due to the disorientation of the orientation of the polyvinyl alcohol or the dye molecule (iodine-containing compound) constituting the polarizer 7.

The width W of the polarization canceling section 23 in the periphery of the through hole 21 of the polarizing plate 1 is not less than 0.00 mu m and less than 32 mu m. 3, the width W of the depolarization section 23 is the width of the polarization separation section 23 in a direction parallel to the surface of the polarizing plate 1. As shown in Fig. Here, the "surface of the polarizing plate 1" may be a first surface (for example, the surface of the third protective film 3), or a second surface on the back surface of the first surface (for example, Surface). The width W of the polarization canceling section 23 observed in the direction perpendicular to the first surface of the polarizing plate 1 is in the range of 0.00 탆 or more and less than 32 탆 and in the direction perpendicular to the second surface of the polarizing plate 1 The width W of the polarized light dissipating portion 23 to be observed may be less than 0.00 mu m and less than 32 mu m. The width W of the polarization canceling section 23 may be referred to as the width of the polarization canceling section 23 in the XY plane direction. The polarizing plate 1 is substantially transparent so that the polarizing resolution portion 23 located on the second surface side (the surface side of the release film 13) is located on the first surface side (the surface side of the third protective film 3 ). That is, the polarized light dissipating portion 23 observed on the first surface side (the surface side of the third protective film 3) is not necessarily formed on the first optical film (the third protective film 3). Further, the polarization canceling section 23 located inside the polarizing plate 1 may be observed from the first surface side or the second surface side. The polarization canceling section 23 located on the first surface side (the surface side of the third protective film 3) may be observed from the second surface side (the surface side of the release film 13). That is, the polarized-light dissociating portion 23 observed on the second surface side (the surface side of the release film 13) is not necessarily formed on the second optical film (the release film 13). The polarizing plate 1 is substantially transparent so that when the surface of the polarizing plate 1 is observed in the direction perpendicular to the surface of the polarizing plate 1 (Z-axis direction), the three- May be seen as overlapping each other. That is to say, the three-dimensionally distributed polarization resolving section 23 around the perforation hole 21 is a two-dimensional orthogonal projection (for example, the through hole 21) in the surface (XY plane) As shown in Fig.

When the width W of the polarization canceling portion 23 is less than 32 탆, light leakage is suppressed. When the width W of the polarization canceling section 23 is 32 탆 or more, the light leakage in the polarization canceling section 23 becomes remarkable. The width W of the depolarization portion 23 of the polarizing plate 1 may be 0.00 mu m or more and 20 mu m or less, 0.00 mu m or more and 19 mu m or less, or 0.00 mu m or more and 18 mu m or less. The smaller the width W of the polarization canceling section 23, the more likely the light leakage is suppressed. Therefore, it is most preferable that the width W of the polarization canceling section 23 is 0.00 mu m. In other words, it is most preferable that the polarization canceling section 23 is not present. The width W of the polarization canceling portion 23 around the through hole 21 may not be constant as long as it is within the range of 0.00 mu m or more and less than 32 mu m. When the width W of the polarization canceling section 23 is not constant, the maximum value of the width W of the polarization canceling section 23 is less than 32 占 퐉.

There is a case where a crack 25 is formed around the through hole 21. [ The crack 25 may be formed along the first surface (the surface of the third protective film 3). The crack 25 may be formed along the second surface (the surface of the release film 13) on the back surface of the first surface. The cracks 25 may be formed continuously or discontinuously in a direction (Z-axis direction) perpendicular to the surface of the polarizing plate 1. [ That is, the crack 25 may have a depth from the surface of the polarizing plate 1. In other words, the cracks 25 may be three-dimensionally distributed.

The number of cracks 25 around the through hole 21 of the polarizing plate 1 may be 0 or more and 3 or less per 1 mm of the unit length. The " unit length 1 mm " is a straight line or a curved line parallel to the edge of the through hole 21 and having a length of 1 mm. For example, when the shape of the through hole 21 is the cause, the unit length is an arc parallel to the circular edge of the through hole 21. [ The number of cracks 25 is the number of cracks 25 crossing the unit length of 1 mm among the cracks 25 observed in the direction perpendicular to the surface of the polarizing plate 1 (Z-axis direction). The crack 25 observed on the first surface (for example, the surface of the third protective film 3) may be counted. The crack 25 observed on the second surface (for example, the surface of the release film 13) on the back surface of the first surface may be counted. The number of cracks 25 observed on the first surface of the polarizing plate 1 is not less than 0 and not more than 3 per unit length of 1 mm and the number of the cracks 25 observed on the second surface of the polarizing plate 1 The number may be 0 or more and 3 or less per unit length of 1 mm. The crack 25 located on the second front surface side (the front surface side of the release film 13) is separated from the first front surface side (the front surface side of the third protective film 3) May be observed. That is, the crack 25 observed on the first surface side (the surface side of the third protective film 3) is not necessarily formed on the first optical film (the third protective film 3). Further, the crack 25 located inside the polarizing plate 1 may be observed from the first surface side or the second surface side. The crack 25 located on the first surface side (the surface side of the third protective film 3) may be observed from the second surface side (the surface side of the release film 13). That is, the crack 25 observed on the second surface side (the surface side of the release film 13) is not necessarily formed on the second optical film (release film 13). The polarizing plate 1 is substantially transparent so that when the surface of the polarizing plate 1 is observed in the direction perpendicular to the surface of the polarizing plate 1 (Z-axis direction), the three- They may be seen as overlapping each other. That is, the three-dimensionally distributed cracks 25 may be observed as a two-dimensional orthogonal projection on the surface (XY plane) of the polarizing plate 1. A plurality of cracks 25 overlapping each other in a direction perpendicular to the surface of the polarizing plate 1 (Z-axis direction) may be seen as one crack 25 on the surface of the polarizing plate 1. [ That is, a plurality of cracks 25 overlapping each other in the direction (Z-axis direction) perpendicular to the surface of the polarizing plate 1 may be counted as one crack 25 on the surface of the polarizing plate 1.

When the number of the cracks 25 is 3 or less, light leakage is more likely to be suppressed. The length l of the crack 25 may be less than or equal to 0 占 퐉 and less than or equal to 50 占 퐉. The length l of the crack 25 is the length of the crack 25 observed in the direction perpendicular to the surface of the polarizing plate 1 (Z-axis direction), and the length of one end of the crack 25, 21). The length l of the crack 25 may be measured on the first surface (e.g., the surface of the third protective film 3). The length l of the crack 25 may be measured on the second surface (for example, the surface of the release film 13) on the back surface of the first surface. The length l of the crack 25 measured on the first surface of the polarizing plate 1 is 0 占 퐉 or more and less than 50 占 퐉 and the length of the crack 25 measured on the second surface of the polarizing plate 1 (1) may be 0 탆 or more and less than 50 탆. When the length l of the crack 25 is less than 50 占 퐉, light leakage to such an extent that visibility is more likely to be suppressed. The smaller the number of cracks 25 and the shorter the crack 25, the more likely the light leakage is suppressed. The smaller the number of cracks 25 and the shorter the crack 25, the higher the mechanical strength of the polarizing plate 1 and the breakage of the polarizing plate 1 during the manufacturing process of the image display apparatus is likely to be suppressed. Therefore, it is most preferable that no crack 25 is present.

The diameter d (the inner diameter d1 or d2) of the through hole 21 may be, for example, 50 to 5000 mu m.

In the method of manufacturing the polarizing plate 1 according to the present embodiment,

A step of forming a laminate by superimposing a film polarizer and a plurality of optical films, and a step of forming a hole (through hole 21) through the laminate by irradiating the laminate with a pulse wave of an excimer laser Process,

The output of the excimer laser is less than 20 W,

The intensity of the outer peripheral portion of the spot of the excimer laser is larger than 80% of the maximum intensity of the spot,

The converging diameter of the excimer laser is larger than 50 占 퐉,

The repetition frequency of the excimer laser is less than 1000 Hz.

In the present embodiment, a through hole 21 is formed in a portion of the laminate where the excimer laser is irradiated. Hereinafter, each step will be described in detail.

The laminate is obtained by repeating the fusion of the polarizer 7 and the optical films 3, 5, 9 and 13 or the fusion of the optical films. The adhesive layer 11 may be formed by applying an adhesive to the surface of the second protective film 9, for example.

The excimer laser may be any of the following.

F ₂ laser (oscillation wavelength: 157 nm)

ArF laser (oscillation wavelength: 193 nm)

KrF laser (oscillation wavelength: 248 nm)

XeCl laser (oscillation wavelength: 308 nm)

XeF laser (oscillation wavelength: 351 nm)

The oscillation wavelength of the excimer laser is much shorter than the oscillation wavelength of the other laser. For example, the oscillation wavelength of the CO ₂ laser is 9.4 탆 or 10.6 탆. The polymers constituting the polarizers 7 and the optical films 3, 5, 9, and 13 are likely to be instantaneously decomposed and sublimated when the excimer laser having a short wavelength is irradiated to the laminate, Heating of the sieve is suppressed. Therefore, the through holes 21 having a small degree of verticality are easily formed instantaneously, and the chemical alteration of the polarizer 7 and the optical films 3, 5, 9, and 13 caused by heat is also suppressed. On the other hand, in the case of irradiating a laser with a long wavelength to the laminate, the temperature tends to rise at the portion irradiated with the laser, but the temperature of the polarizer 7 and the polymer constituting each optical film 3, 5, 9, Decomposition and sublimation are difficult to occur. That is, through holes are formed only when the heated portion is melted and deformed by laser irradiation. Therefore, if a laser having a wavelength longer than that of the excimer laser is used, it is difficult to control the verticality of the through hole, and the polarization deterioration of the polarizer 7 and the optical films 3, 5, 9, It is easy to form.

The output of the excimer laser is 1 W or more and less than 20 W. When the output of the excimer laser is 20 W or more, cracks 25 are easily formed around the through hole 21, and the width W of the polarization canceling portion 23 is likely to become large. The output of the excimer laser may be 5 W or more and 8 W or less.

As shown in Fig. 4, the spot LS of the excimer laser is circular. The intensity distribution ID of the spot LS of the excimer laser along the straight line passing through the center Lc of the spot LS of the excimer laser is top hat type. The spot LS may be said to be a cross section of the excimer laser perpendicular to the advancing direction of the excimer laser. The vertical degree of the through hole formed by using the top hat type excimer laser tends to be smaller than the vertical degree of the through hole formed by using the excimer laser whose intensity distribution is Gauss type. The intensity ILe of the outer peripheral portion Le of the spot LS of the excimer laser is greater than 80% of the maximum intensity ILc of the intensity of the spot LS and not more than 100% of ILc. In other words, (ILe / ILc) x 100 is more than 80% and not more than 100%. In other words, {(ILc-ILe) / ILc} x 100 is 0% or more and less than 20%. ILc may be said to be an average value of the strength of the flat portion in the intensity distribution ID. ILc may be said to be the intensity of the center Lc of the spot LS. When ILe is 80% or less of the ILc, the vertical degree (a / b) tends to become large. In other words, when (ILe / ILc) x 100 is 80% or less, the vertical degree (a / b) tends to become large. In other words, when {(ILc-ILe) / ILc} x 100 is 20% or more, the vertical degree (a / b) tends to become large. The ILe may be 90% or more and 95% or less of the ILc. In other words, (ILe / ILc) x 100 may be 90% or more and 95% or less. In other words, {(ILc-ILe) / ILc} x 100 may be 5% or more and 10% or less. The unit of the intensity ILe and the intensity ILc may be, for example, W / m ² .

In the case of forming the through hole 21 having the diameter d equal to the condensing diameter of the excimer laser, the condensing diameter of the excimer laser is larger than 50 탆 and not larger than 2000 탆. When the light condensing diameter of the excimer laser is 50 m or less, the vertical degree (a / b) tends to become large. The condensing diameter of the excimer laser may be said to be the diameter of the spot LS of the excimer laser. The condensing diameter of the excimer laser may be 600 μm or more and 1000 μm or less. The condensing diameter of the excimer laser does not have to be the same as the diameter d of the through hole 21. [ For example, a predetermined area on the surface of the laminate may be scanned with an excimer laser having a small condensing diameter to form the through hole 21 having a diameter d larger than the excimer laser condensing diameter.

The repetition frequency of the excimer laser is 10 Hz or more and less than 1000 Hz. When the repetition frequency of the excimer laser is 1000 Hz or more, the crack 25 is likely to be formed, and the polarization canceling section 23 is also likely to be formed. The repetition frequency of the excimer laser may be 100 Hz or more and 500 Hz or less.

The inner diameter of the through hole 21 on the surface side (for example, the third protective film 3 side) irradiated with the excimer laser is larger than the inner diameter of the through hole 21 on the opposite side (for example, There is a big tendency.

The polarizer 7 may be a film-type polyvinyl alcohol resin produced by processes such as stretching, dyeing and crosslinking. Details of the polarizer 7 are as follows.

For example, first, the film-like polyvinyl alcohol resin is stretched in the uniaxial or biaxial direction. The two-color ratio of the polarizer 7 stretched in the uniaxial direction tends to be high. Following the stretching, the polyvinyl alcohol resin is dyed with iodine or a dichroic dye (polyiodide) using a dyeing solution containing potassium iodide or the like. The dyeing solution may contain boric acid, zinc sulfate, or zinc chloride. The polyvinyl alcohol resin may be washed with water before dyeing. The contaminants and the antiblocking agent are removed from the surface of the polyvinyl alcohol resin by washing with water. Further, as a result of swelling of the polyvinyl alcohol resin by washing with water, unevenness of dyeing (uneven dyeing) tends to be suppressed. The polyvinyl alcohol resin after dyeing is treated with a solution of a crosslinking agent (for example, an aqueous solution of boric acid) for crosslinking. After the treatment with the crosslinking agent, the polyvinyl alcohol resin is washed with water and then dried. The polarizer 7 is obtained through the above procedure. The polyvinyl alcohol resin is obtained by saponifying a polyvinyl acetate resin. The polyvinyl acetate resin may be, for example, a polyvinyl acetate which is a homopolymer of vinyl acetate, or a copolymer of vinyl acetate and another monomer (for example, ethylene-vinyl acetate copolymer). Other monomers copolymerizable with vinyl acetate may be acrylamides having unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, or ammonium groups in addition to ethylene. The polyvinyl alcohol resin may be modified with aldehydes. The modified polyvinyl alcohol resin may be, for example, partially formalized polyvinyl alcohol, polyvinyl acetal, or polyvinyl butyral. The polyvinyl alcohol-based resin may be a polyene-based oriented film such as a dehydrated product of polyvinyl alcohol or dehydrochlorinated product of polyvinyl chloride. Staining may be performed before stretching, or stretching may be performed in a staining solution. The length of the stretched polarizer 7 may be, for example, 3 to 7 times the length before stretching.

The thickness of the polarizer 7 may be, for example, 1 mu m or more and 50 mu m or less, or 4 mu m or more and 30 mu m or less. Generally, when the thin polarizer 7 is stretched in the uniaxial direction, cracks 25 are likely to be formed along the stretching direction in the perforating process or the chip-cutting process. However, the formation of the cracks 25 can be suppressed by the above-described boring process using the excimer laser.

The first protective film 5 and the second protective film 9 may be a thermoplastic resin having translucency or an optically transparent thermoplastic resin. Examples of the resin constituting the first protective film 5 and the second protective film 9 include resins such as a chain polyolefin resin, a cyclic olefin polymer resin (COP resin), a cellulose ester resin, a polyester resin, a poly A carbonate resin, a (meth) acrylic resin, a polystyrene resin, or a mixture or copolymer thereof. The composition of the first protective film (5) may be completely the same as that of the second protective film (9). The composition of the first protective film (5) may be different from that of the second protective film (9).

The chain-like polyolefin-based resin may be a homopolymer of a chain-like olefin such as a polyethylene resin or a polypropylene resin. The chain type polyolefin type resin may be a copolymer comprising two or more kinds of chain type olefins.

The cyclic olefin polymer resin (cyclic polyolefin resin) may be, for example, a ring-opened (co) polymer of a cyclic olefin or an addition polymer of a cyclic olefin. The cyclic olefin polymer resin may be, for example, a copolymer of a cyclic olefin and a chain olefin (for example, a random copolymer). The chain olefin constituting the copolymer may be, for example, ethylene or propylene. The cyclic olefin polymer-based resin may be a graft polymer obtained by modifying the above-mentioned polymer with an unsaturated carboxylic acid or a derivative thereof, or a hydride thereof. The cyclic olefin polymer-based resin may be a norbornene-based resin using a norbornene-based monomer such as norbornene or a polycyclic norbornene-based monomer.

The cellulose ester resin may be, for example, cellulose triacetate (triacetyl cellulose (TAC)), cellulose diacetate, cellulose tripropionate or cellulose dipropionate. Or a copolymer thereof may be used. A cellulose ester resin in which a part of the hydroxyl group is modified with another substituent may be used.

A polyester resin other than a cellulose ester resin may be used. The polyester resin may be, for example, a polycondensation product of a polycarboxylic acid or a derivative thereof and a polyhydric alcohol. The polycarboxylic acid or its derivative may be a dicarboxylic acid or a derivative thereof. The polycarboxylic acid or its derivative may be, for example, terephthalic acid, isophthalic acid, dimethyl terephthalate, or dimethyl naphthalenedicarboxylate. The polyhydric alcohol may be, for example, diol. The polyhydric alcohol may be, for example, ethylene glycol, propanediol, butanediol, neopentyl glycol, or cyclohexanedimethanol.

Examples of the polyester-based resin include polyolefin such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polycyclohexanedimethyl terephthalate, or polycyclohexane Dimethyl naphthalate may be used.

The polycarbonate resin is a polymer having a polymerization unit (monomer) bonded through a carbonate group. The polycarbonate resin may be a modified polycarbonate having a modified polymer skeleton, or may be a copolymerized polycarbonate.

Examples of the (meth) acrylic resin include poly (meth) acrylate (for example, polymethyl methacrylate (PMMA)); Methyl methacrylate- (meth) acrylic acid copolymer; Methyl methacrylate- (meth) acrylic acid ester copolymer; Methyl methacrylate-acrylic acid ester- (meth) acrylic acid copolymer; (Meth) acrylate-styrene copolymer (e.g., MS resin); Or a copolymer of methyl methacrylate and a compound having an alicyclic hydrocarbon group (e.g., methyl methacrylate-cyclohexyl methacrylate copolymer, methyl methacrylate- (meth) acrylate norbornyl copolymer, etc.).

At least one of the optical films of the pair of optical films (the first protective film 5 and the second protective film 9) sandwiching the polarizer 7 may contain triacetyl cellulose (TAC). Even if at least one of the optical films of the pair of optical films (the first protective film 5 and the second protective film 9) sandwiching the polarizer 7 contains the cyclic olefin polymer resin (COP resin) good. At least one of the optical films of the pair of optical films (the first protective film 5 and the second protective film 9) sandwiching the polarizer 7 may include polymethyl methacrylate (PMMA). Both of the pair of optical films (the first protective film 5 and the second protective film 9) sandwiching the polarizer 7 may contain triacetyl cellulose. One of the pair of optical films (the first protective film 5 and the second protective film 9) sandwiching the polarizer 7 includes triacetylcellulose and the polarizer 7 is interposed The other film of the pair of optical films may contain a cyclic olefin polymer. One of the pair of optical films (the first protective film 5 and the second protective film 9) sandwiching the polarizer 7 includes triacetylcellulose and the polarizer 7 is interposed And the other film of the pair of optical films may contain methyl polymethacrylate. One of the pair of optical films (the first protective film 5 and the second protective film 9) sandwiching the polarizer 7 includes the cyclic olefin polymer resin and the polarizer 7 is sandwiched between the And the other film of the pair of optical films may contain methyl polymethacrylate. When the optical film made of TAC, COP resin or PMMA is in contact with the polarizer 7, the perpendicularity (a / b) of the through hole 21 is reduced by the conventional processing method, And the formation of cracks 25 are difficult to suppress. However, by the above boring process using the excimer laser, the vertical degree (a / b) of the through hole 21 is reduced and the formation of the polarization canceling section 23 and the crack 25 is suppressed.

The glass transition temperature (Tg) of the polarizer 7 or each optical film 3, 5, 9 or 13 may be 100 to 180 캜 or 108 to 180 캜. When the optical film 3, 5, 9 or 13 is made of triacetyl cellulose (TAC), the glass transition temperature (Tg) of the optical film 3, 5, 9 or 13 may be 160 to 180 캜. When the optical film (3, 5, 9 or 13) is made of a cyclic olefin polymer resin (COP resin), the glass transition temperature (Tg) It may be. When the optical film 3, 5, 9 or 13 is made of polymethyl methacrylate (PMMA), the glass transition temperature Tg of the optical film 3, 5, 9 or 13 may be 108 to 136 占 폚 . When the glass transition temperature (Tg) of the polarizer 7 and the optical films 3, 5, 9 and 13 is 100 占 폚 or more, the polarizing plate 1 is excellent in heat resistance, So that the deformation of the substrate 1 is liable to be suppressed.

The first protective film 5 or the second protective film 9 may contain at least one additive selected from the group consisting of a lubricant, a plasticizer, a dispersant, a heat stabilizer, an ultraviolet absorber, an infrared absorber, an antistatic agent, May be included.

The thickness of the first protective film 5 may be, for example, 5 mu m or more and 90 mu m or less, 5 mu m or more and 80 mu m or less, or 5 mu m or more and 50 mu m or less. The thickness of the second protective film 9 may be, for example, 5 mu m or more and 90 mu m or less, 5 mu m or more and 80 mu m or less, or 5 mu m or more and 50 mu m or less.

The first protective film 5 or the second protective film 9 may be a film having an optical function such as a retardation film or a brightness enhancement film. For example, a retardation film imparted with an arbitrary retardation value can be obtained by stretching a film made of the thermoplastic resin or forming a liquid crystal layer or the like on the film.

The first protective film 5 may be bonded to the polarizer 7 through an adhesive layer. The second protective film 9 may also be bonded to the polarizer 7 through an adhesive layer. The adhesive layer may contain an aqueous adhesive such as polyvinyl alcohol or the like and may include an active energy ray curable resin to be described later.

The active energy ray-curable resin is a resin which is cured by irradiation with active energy rays. The active energy ray may be, for example, ultraviolet rays, visible rays, electron rays, or X rays. The active energy ray curable resin may be an ultraviolet ray curable resin.

The active energy ray-curable resin may be one kind of resin or plural types of resins. For example, the active energy ray-curable resin may include a cationic polymerizable curable compound or a radically polymerizable curable compound. The active energy ray-curable resin may include a cationic polymerization initiator or a radical polymerization initiator for initiating the curing reaction of the curable compound.

The cationically polymerizable curable compound may be, for example, an epoxy compound (compound having at least one epoxy group in the molecule) or an oxetane compound (compound having at least one oxetane ring in the molecule). The radically polymerizable curable compound may be, for example, a (meth) acrylic compound (a compound having at least one (meth) acryloyloxy group in the molecule). The radically polymerizable curable compound may be a vinyl compound having a radically polymerizable double bond.

The active energy ray-curable resin may contain a cationic polymerization accelerator, an ion trapping agent, an antioxidant, a chain transfer agent, a tackifier, a thermoplastic resin, a filler, a flow regulator, a plasticizer, a defoaming agent, an antistatic agent, a leveling agent, .

The adhesive layer 11 may include, for example, a pressure-sensitive adhesive such as an acrylic pressure-sensitive adhesive, a rubber pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, or a urethane pressure-sensitive adhesive. The thickness of the adhesive layer 11 may be, for example, 2 mu m or more and 500 mu m or less, 2 mu m or more and 200 mu m or less, or 2 mu m or more and 50 mu m or less.

The resin constituting the third protective film 3 may be the same as the resin listed as the resin constituting the first protective film 5 or the second protective film 9. The thickness of the third protective film 3 may be, for example, 5 mu m or more and 200 mu m or less.

The resin constituting the release film 13 may be the same as the resin listed as the resin constituting the first protective film 5 or the second protective film 9. The thickness of the release film 13 may be, for example, 5 mu m or more and 200 mu m or less.

The image display device according to the present invention may be, for example, a liquid crystal display device or an organic EL display device. 5, the liquid crystal display device 30 according to the present embodiment includes a liquid crystal cell 10, a polarizing plate 1a which is superimposed on one surface (first surface) of the liquid crystal cell 10, (First polarizing plate) and another polarizing plate 1b (second polarizing plate) superimposed on the other surface (second surface) of the liquid crystal cell 10. The polarizing plates 1a and 1b shown in Fig. 5 are the same as those of the polarizing plate 1 shown in Figs. 1 and 2 except that the release film 13 and the third protective film 3 are not provided. The polarizing plate 1a (first polarizing plate) is adhered to the first surface of the liquid crystal cell 10 through the adhesive layer 11. The polarizing plate 1a (first polarizing plate) comprises an adhesive layer 11 superposed on the first surface of the liquid crystal cell 10, a second protective film 9 superimposed on the adhesive layer 11, A polarizer 7 superimposed on the film 9, and a first protective film 5 superimposed on the polarizer 7. A separate polarizing plate 1b (second polarizing plate) is adhered to the second surface of the liquid crystal cell 10 through the adhesive layer 11. The separate polarizing plate 1b (second polarizing plate) comprises an adhesive layer 11 superposed on the second surface of the liquid crystal cell 10, a second protective film 9 superimposed on the adhesive layer 11, 2 polarizer 7 superimposed on the protective film 9 and a first protective film 5 superimposed on the polarizer 7. [ The liquid crystal cell 10 and the pair of polarizing plates 1a and 1b constitute the liquid crystal panel 20. [ The liquid crystal panel 20 and the backlight (surface light source device) and other members constitute the liquid crystal display device 30. [ The backlight and other members are omitted in Fig.

While the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment at all.

The shape of the polarizing plate may be various depending on the use. Here, the shape of the polarizing plate is the shape of the entire polarizing plate viewed from the Z direction (direction perpendicular to the surface of the polarizing plate 1) in Figs. For example, the shape of the polarizing plate may be a polygon other than a rectangle. For example, the polarizing plate may be circular, elliptical, or irregular. The outer edge of the polarizing plate may be composed of only a straight line (a plurality of sides). Here, the outer edge of the polarizer is the outer edge of the polarizer viewed from the Z direction (direction perpendicular to the surface of the polarizer) in Figs. The outer edge of the polarizing plate may be composed of only a curved line. The shape of each of the polarizers 7 and optical films 3, 5, 9, and 13 may be various shapes depending on applications.

The shape of the through hole in the direction parallel to the surface of the polarizing plate 1 (in the XY plane direction) may be various forms depending on the use of the polarizing plate. The shape of the through hole may be other than a circle. For example, the shape of the through hole may be elliptical, polygonal, or irregular. A plurality of through holes 21 may be formed in the polarizing plate 1. [ A plurality of through holes having the same shape may be formed in the polarizing plate 1. [ A plurality of through holes having different shapes from each other may be formed in the polarizing plate 1. [ The position of the through hole in the polarizing plate 1 is not limited. For example, when the polarizing plate 1 is circular, the through-holes may be formed at the center of the surface of the polarizing plate 1 (the center of the circle).

The number of optical films (optical films superimposed on polarizers) included in the polarizing plate is not limited. The number of optical films provided in the polarizing plate may be one. For example, the polarizing plate 1 shown in Figs. 1 and 2 may not have any one of the first protective film 5 and the second protective film 9, Maybe not. For example, a polarizing plate or both polarizing plates of the polarizing plate 1a (first polarizing plate) and the polarizing plate 1b (second polarizing plate) shown in FIG. 5 are disposed between the first protective film 5 and the second protective film 9 It is not necessary to provide any one of the protective films. Either one polarizing plate or both polarizing plates of the polarizing plate 1a (first polarizing plate) and the polarizing plate 1b (second polarizing plate) shown in Fig. 5 need not be provided with both protective films.

The release film may be disposed on both sides of the polarizing plate through the adhesive layer.

The optical film included in the polarizing plate may be a reflective polarizing film, an antiglare function imparting film, a surface antireflection function imparting film, a reflective film, a transflective film, a viewing angle compensating film, an optical compensation layer, a touch sensor layer, .

The polarizing plate may further comprise a hard coat layer. For example, the polarizing plate 1, the first protective film 5 may be positioned between the hard coat layer and the polarizer 7, and the hard coat layer may be disposed between the first protective film 5 and the third protective film 3 ). In this case, the first protective film 5 may contain triacetylcellulose. The surface hardness (pencil hardness) of the hard coat layer may be H or more and 5H or less, or 2H or more and 5H or less. Pencil hardness is based on Japanese Industrial Standard (JIS K 5400). The hard coat layer having the pencil hardness in the above range is unlikely to be scratched during the manufacturing process of the polarizing plate 1. However, since the hard-coded layer is hard and fragile, cracks tend to be formed in the hard coat layer when the through holes are formed by the conventional processing method. However, it is possible to suppress the formation of cracks in the hard coat layer by the above boring process using the excimer laser.

The hard coat layer is, for example, a layer formed of an acrylic resin film having a fine concavo-convex shape formed on its surface. The hard coat layer may be formed from, for example, a coating film containing organic fine particles or inorganic fine particles. A method of pressing the coating film against a roll having a concavo-convex shape (for example, an embossing method or the like) may be used. After forming a coating film containing no organic fine particles or inorganic fine particles, this coating film may be pressed against a roll having a concavo-convex shape.

The inorganic fine particles may be, for example, silica, colloidal silica, alumina, alumina sol, aluminosilicate, alumina-silica composite oxide, kaolin, talc, mica, calcium carbonate, calcium phosphate and the like. The organic fine particles (resin particles) may be, for example, crosslinked polyacrylic acid particles, methyl methacrylate / styrene copolymer resin particles, crosslinked polystyrene particles, crosslinked polymethyl methacrylate particles, silicone resin particles and polyimide particles .

The binder component for dispersing the inorganic fine particles or the organic fine particles may be selected from a material having a high hardness (hard coat). The binder component may be, for example, an ultraviolet ray hardening resin, a thermosetting resin, or an electron beam hardening resin. From the viewpoints of productivity, hardness and the like, ultraviolet curing resin is preferably used as the binder component.

The thickness of the hard coat layer may be, for example, 2 mu m or more and 30 mu m or less, or 3 mu m or more and 30 mu m or less. When the thickness of the hard coat layer is 2 占 퐉 or more, sufficient hardness of the hard coat layer tends to be obtained, and scratches on the surface of the hard coat layer are less likely to occur. When the thickness of the hard coat layer is 30 占 퐉 or less, the hard coat layer is less likely to be cracked, curling of the polarizing plate due to curing shrinkage of the hard coat layer is easily suppressed, and productivity tends to be improved.

The polarizer 7 may have a thickness of 30 m or less and the polarizer 7 may have a single light transmittance T of 42.5 or more and the polarizer 7 may have a polarization degree P of 99.9 or more. Conventionally, when the polarizer is thin and the single light transmittance and polarization degree are large, light leakage is easily recognized around the through hole formed in the polarizing plate. However, when the through hole 21 having a small vertical degree is formed by the above-described perforating process using an excimer laser, the light leakage in the polarizing plate 1 having the polarizer 7, which is thin and has a high transmittance and high degree of polarization, can do.

The water content of the laminate composed of the three films of the polarizer 7, the first protective film 5 and the second protective film 9 may be 1.0 to 5.0%, 0.5 to 5.5%, or 1.0 to 5.0% . When the moisture content is within the above range, warping of the polarizing plate 1 due to heating is easily suppressed, and light leakage in the polarizing plate 1 is more easily suppressed.

In the polarizing plate 1 shown in Figs. 1 and 2, the inner diameter d1 of the through hole 21 on the side of the third protective film 3 (first optical film side) (D1) of the through hole 21 on the third protective film 3 side (first optical film side) is larger than the inner diameter d2 of the through hole 21 on the second protective film 3 side May be smaller than the inner diameter d2 of the through hole 21 on the release film 13 side (second optical film side). In other words, in the polarizing plate 1 shown in Figs. 1 and 2, the inner diameter d1 of the through hole 21 on the first protective film 5 side is smaller than the inner diameter d1 of the through hole 21 on the side of the second protective film 9 The inner diameter d1 of the through hole 21 on the first protective film 5 side is larger than the inner diameter d2 of the through hole 21 on the second protective film 9 side 21 may be smaller than the inner diameter d2.

The polarizing plate 1 may not be provided with one or both of the third protective film 3 and the release film 13. For example, the third protective film 3 may be peeled off from the polarizing plate 1 and removed in the manufacturing process of the image display apparatus. That is, the third protective film 3 may be a temporary protective film. The release film 13 may also be peeled off from the polarizing plate 1 and removed in the manufacturing process of the image display apparatus.

Example

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

(Example 1)

A plate-like laminate composed of the polarizer 7 and the optical films 3, 5, 9, and 13 as shown in Fig. 1 was formed. The laminate includes a release film 13, an adhesive layer 11 superimposed on the release film 13, a second protective film 9 superimposed on the adhesive layer 11, a second protective film 9, A first protective film 5 superimposed on the polarizer 7 and a third protective film 3 superimposed on the first protective film 5. The polarizer 7 has a polarizer 7, As the polarizer 7, a stretched film type polyvinyl alcohol which was dyed was used. As the first protective film 5, a triacetylcellulose (TAC) film (25KCHCN-TC manufactured by Toppan Printing Co., Ltd.) with a hard coat was used. As the second protective film 9, a film (ZF14-023-1350 manufactured by Nippon Zeon Co., Ltd.) comprising a cyclic olefin polymer resin (COP type resin) was used. As the third protective film 3, a PET protective film with an adhesive (AS3-304 manufactured by Fujimori Kogyo Co., Ltd.) was used. As the release film 13, PET (SP-PLR382050 manufactured by Lintec Corporation) was used. The thickness of the release film 13 was 38 mu m. The thickness of the adhesive layer 11 was 20 占 퐉. The thickness of the second protective film 9 was 23 占 퐉. The thickness of the polarizer 7 was 12 占 퐉. The thickness of the first protective film 5 was 32 탆. The thickness of the third protective film 3 was 60 占 퐉. The total thickness of the laminate (thickness corresponding to the thickness (b) of the polarizing plate 1) was 185 占 퐉. The overall width of the laminate was 110 mm. The overall width of the laminate was 60 mm.

A pulsed wave of an excimer laser was applied to the surface of the laminate on the side of the third protective film 3 to form through-holes 21 as shown in Figs. 1 and 2 on the laminate. The polarizing plate (1) of Example 1 was obtained by various processes described above. As the excimer laser, an ArF laser having an oscillation wavelength of 193 nm was used. As the oscillator of the excimer laser, MLI series (Model 1000) manufactured by Mlase was used. The output of the excimer laser was set at 5 W. As shown in Fig. 4, the spot LS of the excimer laser was circular. The intensity of the outer periphery Le of the spot LS of the excimer laser is denoted by ILe and the maximum intensity of the intensity of the spot LS is denoted ILc by ILc-ILe / ILc } X 100 was 5%. Hereinafter, {(ILc-ILe) / ILc} x 100 is referred to as a " density distribution ". The condensing diameter of the excimer laser was set to 1000 mu m. The repetition frequency of the excimer laser was set to 100 Hz.

As shown in Fig. 3, the shape of the through hole 21 in the direction parallel to the surface of the polarizing plate 1 (in the XY plane direction) was a circle. The opening of the through hole 21 on the side of the third protective film 3 and the opening of the through hole 21 on the side of the release film 13 were a pair of concentric circles. And the inner diameter d1 (diameter) of the through hole 21 (circular opening) on the side of the third protective film 3 was measured. The inner diameter d2 (diameter) of the through hole 21 (circular opening) on the release film 13 side was also measured. The inner diameter d1 of the through hole 21 on the side of the third protective film 3 irradiated with the excimer laser is larger than the inner diameter d2 of the through hole 21 on the opposite side (the side of the release film 13) ). Both the measured values of d1 and d2 were close to the condensing diameter of the excimer laser. (d1-d2) / 2b, which is the vertical degree of the through hole 21, was calculated from the measured values of d1 and d2. The vertical degree of Example 1 was 0.06.

The periphery of the through hole 21 on the side of the third protective film 3 irradiated with the excimer laser was observed with an optical microscope. By this observation, it was attempted to count the number of cracks having a length I of less than 50 mu m and the number of cracks having a length I of 50 mu m or more, out of the cracks formed around the through holes 21. [ The definition of the number of cracks was the same as in the above-described embodiment. In addition, the definition of the length l of the crack was the same as in the above embodiment. As a result of the observation, there was no crack having a length l of less than 50 占 퐉 around the through hole 21 of the polarizing plate 1 of Example 1. Fig. Further, no cracks having a length l of 50 mu m or more were found around the through-holes 21 of the polarizing plate 1 of Example 1.

Measurement of the width W of the depolarization section 23 (discoloration section) around the through hole 21 was attempted by the above observation using an optical microscope. However, around the through hole 21 of the polarizing plate 1, there was no polarization canceling portion 23.

6 (a) and 6 (b), the entire surface of the backlight 64 (surface light source) was covered with the lower polarizing plate 62. The lower polarizer 62 is a polarizer separate from the polarizer of Example 1. The release film 13 of the polarizing plate 1s of Example 1 was faced to the lower polarizing plate 62. [ The polarizing plate 1s of Example 1 was superimposed on the lower polarizing plate 62 and the absorption axis A1s of the polarizing plate 1s of Example 1 was orthogonalized to the absorption axis A62 of the lower polarizing plate 62 . The upper polarizing plate 60 was superimposed on the polarizing plate 1s of Example 1 and the absorption axis A60 of the upper polarizing plate 60 was set parallel to the absorption axis A1s of the polarizing plate 1s of Example 1 Placed. The upper polarizer 60 is also a polarizer separate from the polarizer of Example 1.

The backlight 64 was turned on in the state that the polarizing plate 1s of Example 1 was arranged as described above, and the polarizing plate 1s of Example 1 was visually observed. As a result of observation, there was no light leakage around the through hole 21s of the polarizing plate 1s.

(Examples 2 to 7 and Comparative Examples 1 to 4)

In Example 6, a KrF laser (oscillation wavelength: 248 nm) was used as the excimer laser instead of the ArF laser.

In Example 7, the same laminate as in Example 1 was used, except that the release film 13, the adhesive layer 11 and the third protective film 3 were not provided. Hereinafter, for convenience of explanation, the second protective film side of the polarizing plate of Example 7 is regarded as the " release film side " of the polarizing plate of Example 7. [ The first protective film side of the polarizing plate of Example 7 is regarded as the " third protective film side " of the polarizing plate of Example 7. [ In Table 1, the third protective film is denoted by " Pf ", and the release film is denoted by " Sp ".

In Examples 2 to 7 and Comparative Examples 1 to 4, the output of the excimer laser, the density distribution, the condensing diameter, and the repetition frequency were set to the values shown in Table 1 below.

Except for the above, through-holes were formed in the laminate using an excimer laser in the same manner as in Example 1 to obtain polarizing plates of Examples 2 to 7 and Comparative Examples 1 to 4, respectively.

The vertical degrees of the through-holes of the polarizing plates of Examples 2 to 7 and Comparative Examples 1 to 4 were obtained in the same manner as in Example 1. [ The vertical profiles of Examples 2 to 7 and Comparative Examples 1 to 4 are shown in Table 1 below.

The surface of the third protective film irradiated with the excimer laser was observed for each of Examples 2 to 7 and Comparative Examples 1 to 4 in the same manner as in Example 1 to count the number of cracks formed around the through hole, The length of each crack was measured. Table 1 shows the number of cracks for each of Examples 2 to 7 and Comparative Examples 1 to 4. In any of the examples, the number of cracks formed around the through hole was 3 or less. In any of the examples, the length of the crack formed around the through hole was less than 50 mu m.

The surface of the third protective film side was observed for each of Examples 2 to 7 and Comparative Examples 1 to 4 in the same manner as in Example 1 to measure the width of the depolarized portion (discolored portion) around the through hole did. Table 1 shows the width (W) of the depolarized portion (discolored portion) for each of Examples 2 to 7 and Comparative Examples 1 to 4. In any of the examples, the width of the depolarization portion (discolored portion) was less than 32 mu m.

In the same manner as in Example 1, light leakage around the through hole of the polarizing plate was examined for each of Examples 2 to 7 and Comparative Examples 1 to 4. The test results are shown in Table 1 below.

The polarizing plate related 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 device.

1, 1a, 1b, 1s: Polarizer plate 3: Third protective film 5: First protective film 7: Polarizer 9: Second protective film 10: Liquid crystal cell 11: Adhesive layer 13: A liquid crystal panel (image display device), W: width of a polarization canceling portion, l: length of a crack.

Claims (7)

1. A polarizing plate comprising a film-type polarizer and a plurality of optical films superimposed on the polarizer,
Wherein a vertical degree of the hole passing through the polarizing plate is 0.00 or more and less than 0.32,
And the width of the depolarization portion around the hole is not less than 0.00 mu m and less than 32 mu m. The polarizer according to claim 1, wherein the number of cracks around the hole is 0 or more and 3 or less per 1 mm of unit length. The polarizing plate according to claim 1 or 2, wherein a length of the crack in the periphery of the hole is 0 占 퐉 or more and less than 50 占 퐉. The polarizing plate according to any one of claims 1 to 3, wherein at least one of the optical films of the pair of optical films sandwiching the polarizer comprises triacetyl cellulose. The polarizing plate according to any one of claims 1 to 4, wherein at least one of the optical films of the pair of optical films sandwiching the polarizer comprises an annular olefin polymer. The polarizing plate according to any one of claims 1 to 5, wherein at least one of the optical films of the pair of optical films sandwiching the polarizer comprises methyl polymethacrylate. An image display device comprising the polarizing plate according to any one of claims 1 to 6.

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