JP2020166226A - Polarizing plate - Google Patents

Abstract

To provide a polarizing plate which exhibits just small misalignment at a through-hole section even in a high temperature environment.SOLUTION: A polarizing plate of the present invention comprises a polarizer, a protective layer provided on at least one side of the polarizer, and an adhesive layer. The polarizing plate has a through-hole formed therethrough at or near an edge thereof, and exhibits a misalignment of 300 μm or less at the through-hole section after going through a heat test involving heating the polarizing plate pasted onto a glass plate via the adhesive layer for 120 hours at 85°C.SELECTED DRAWING: Figure 2

Description

The present invention relates to a polarizing plate. More specifically, the present invention relates to a polarizing plate having a pressure-sensitive adhesive layer and having through holes formed therein.

Polarizing plates are widely used in image display devices such as mobile phones and notebook personal computers in order to realize image display and / or enhance the performance of the image display. In recent years, with the rapid spread of smartphones and touch panel type information processing devices, image display devices equipped with cameras have come to be widely used. Correspondingly, a polarizing plate having a through hole at a position corresponding to the camera unit has also been widely used. In a polarizing plate having such a through hole, there are various considerations in or near the through hole.

International Publication No. 2017/047510

The present invention has been made to solve the above-mentioned conventional problems, and a main object thereof is to provide a polarizing plate having a small deviation in a through-hole portion even in a high temperature environment.

The polarizing plate of the present invention has a polarizer, a protective layer arranged on at least one side of the polarizer, and an adhesive layer. In this polarizing plate, through holes are formed at or near the end, and the polarizing plate is attached to a glass plate via the pressure-sensitive adhesive layer and subjected to a heating test at 85 ° C. for 120 hours. Later, the amount of displacement of the polarizing plate in the through hole portion is 300 μm or less.
In one embodiment, the distance A (μm) from the outermost part of the pressure-sensitive adhesive layer in the thickness direction to the center of the polarizer in the thickness direction, the thickness T _pol (μm) of the polarizer, and the creep of the pressure-sensitive adhesive layer. The value C _psa (μm / hr), the thickness T _psa (μm) of the pressure-sensitive adhesive layer, and the thickness T _pro (μm) of the protective layer satisfy the following relationship:
(A × T _pol ) × (C _psa × T _psa ) / T _pro = K ≦ 350 × 10 ² (μm ³ / hr).
In one embodiment, the polarizer thickness T _pol is 20 μm or less. In one embodiment, the polarizer thickness T _pol is 10 μm or less. In one embodiment, the amount of displacement of the polarizing plate in the through-hole portion is 120 μm or less.
In one embodiment, the thickness T _psa of the pressure-sensitive adhesive layer is 10 μm to ₂₂ μm.
In one embodiment, the amount of displacement of the polarizing plate is substantially the amount of displacement of the pressure-sensitive adhesive layer.
In one embodiment, the through holes are formed in the corners. In one embodiment, the distance from the center in the longitudinal direction to the end in the longitudinal direction when the polarizer is viewed in a plan view is L ₁ , and the distance from the center in the longitudinal direction to the center of the through hole in the longitudinal direction is L ₁ . L ₂ , the distance from the center of the polarizer to the end in the lateral direction is W ₁ , and the distance from the center of the polarizer in the lateral direction to the center of the through hole is W ₂ . When this is done, the through hole is formed at a position satisfying 0.85 ≦ L ₂ / L ₁ ≦ 0.99 and 0.50 ≦ W ₂ / W ₁ ≦ 0.99.
In one embodiment, the polarizing plate has a rectangular shape, and the absorption axis direction of the polarizer is substantially parallel to the longitudinal direction.
In one embodiment, the protective layer is located on only one side of the polarizer.
In one embodiment, the diameter of the through hole is 10 mm or less.
In one embodiment, the polarizing plate has an aspect ratio of 1.3 to 2.5.
According to another aspect of the present invention, an image display device is provided. This image display device includes an image display cell and the above-mentioned polarizing plate, and the polarizing plate is attached to the image display cell via the above-mentioned adhesive layer.

According to the embodiment of the present invention, it is possible to realize a polarizing plate having a through hole and having a small deviation in the through hole portion even in a high temperature environment.

It is a schematic plan view explaining the formation position of the through hole in the polarizing plate by embodiment of this invention. It is a schematic sectional view of the polarizing plate shown on the left side of FIG. 1 by line II-II. It is an enlarged cross-sectional view of the main part explaining the deviation in the through hole part in the polarizing plate according to embodiment of this invention. 6 is a graph showing the relationship between the K value and the amount of deviation for a polarizing plate in which the absorption axis is in the 0 ° direction obtained in Examples and Comparative Examples. 6 is a graph showing the relationship between the K value and the amount of deviation for a polarizing plate having an absorption axis in the 90 ° direction obtained in Examples and Comparative Examples.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. The drawings are schematically shown for easy viewing, and the ratios of length, width, thickness, etc., angles, etc. in the drawings are different from the actual ones.

A. Overall Configuration of Polarizing Plate FIG. 1 is a schematic plan view illustrating the position of formation of through holes in the polarizing plate according to the embodiment of the present invention; FIG. 2 is based on line II-II of the polarizing plate shown on the left side of FIG. It is a schematic sectional view. The polarizing plate 100 of the illustrated example has a polarizing element 11, a protective layer (hereinafter, may be referred to as an outer protective layer) 12 arranged on one side of the polarizing element 11, and the other side of the polarizing element 11. It has an arranged protective layer (hereinafter, may be referred to as an inner protective layer) 13 and an adhesive layer 20. The pressure-sensitive adhesive layer 20 is used to attach the polarizing plate 100 to the image display cell. Either the outer protective layer 12 or the inner protective layer 13 may be omitted depending on the purpose, the desired configuration, and the like.

In the embodiment of the present invention, a through hole 30 is formed at or near the end of the polarizing plate 100. By forming the through hole, for example, when the image display device has a built-in camera, it is possible to prevent an adverse effect on the camera performance. Further, by forming the through hole at or near the end of the polarizing plate, the influence on the image display can be minimized when the polarizing plate is applied to the image display device. The through hole can be formed by various methods such as laser processing, cutting with an end mill, and punching with a Thomson blade or a pinnacle blade. The polarizing plate typically has a rectangular shape as shown in FIG. In the present specification, the term "rectangular shape" includes a shape including a deformed portion such as an R shape in which each vertex is chamfered as shown in FIG. The through hole 30 may be provided at a substantially central portion of the longitudinal end portion of the polarizing plate, may be provided at a predetermined position at the longitudinal end portion, or may be provided at a corner portion of the polarizing plate. When the through hole is provided at a predetermined position (including the substantially central portion) of the longitudinal end portion, the through hole is located so that the center of the hole is within, for example, 10 mm from the short side (longitudinal end). Provided. In one embodiment, the distance from the center of the polarizer in the longitudinal direction to the end in the longitudinal direction of FIG. 1 is L ₁ , and the distance in the longitudinal direction from the center of the polarizer to the center of the through hole is L _2. , The through hole is preferably formed at a position satisfying 0.85 ≦ L ₂ / L ₁ ≦ 0.99. L ₂ / L ₁ is more preferably 0.99 to 0.97, and even more preferably 0.92 to 0.96. When the through hole is provided in the corner, for example, the center of the through hole is within 10 mm from the short side (longitudinal end) and within 10 mm from the long side (short end). It is provided at such a position. In one embodiment, the through hole is preferably formed at a position satisfying 0.85 ≤ L ₂ / L ₁ ≤ 0.99, and the polarizer is formed from the center in the lateral direction to the lateral direction. When the distance to the end is W ₁ and the distance from the center of the polarizer in the lateral direction to the center of the through hole is W ₂ , 0.50 ≤ W ₂ / W ₁ ≤ 0.99. It is formed in a position that satisfies. L ₂ / L ₁ is more preferably 0.99 to 0.97, and even more preferably 0.92 to 0.96. W ₂ / W ₁ is more preferably 0.75 to 0.95. In the illustrated example, the case where the through hole is provided at the end in the longitudinal direction is shown, but the through hole may be provided at the end in the lateral direction. Although not shown, a plurality of through holes may be provided. Further, as the plan view shape of the through hole, any appropriate shape may be adopted depending on the purpose. Specific examples of the plan view shape include a circle, an ellipse, a square, a rectangle, and a combination thereof (for example, a rectangle having an arcuate end) as shown in the illustrated example. Further, a deformed portion (for example, U-shaped notch, V-shaped notch) may be provided together with the through hole. When a through hole is formed in the polarizing plate, the present inventors have caused a displacement of the polarizing plate (substantially, a displacement of the pressure-sensitive adhesive layer) at the through hole portion in a high temperature environment, and as a result, the penetration hole occurs. We have discovered a new problem that light leakage may occur in the hole portion, and solved the problem by adopting the predetermined configuration of the embodiment of the present invention. That is, the present invention solves a new problem that has not been known until now, and the effect obtained by this is unexpectedly excellent.

In the embodiment of the present invention, as shown in FIG. 3, the polarizing plate 100 is in a state where the polarizing plate 100 is attached to a glass plate (which can correspond to a substrate of an image display cell) 120 via an adhesive layer 20. The deviation amount D in the through hole 30 portion after being subjected to the heating test at 85 ° C. and 120 hours is 300 μm or less. The deviation amount D is preferably 250 μm or less, more preferably 200 μm or less, further preferably 150 μm or less, particularly preferably 120 μm or less, particularly preferably 100 μm or less, and most preferably 80 μm or less. is there. The smaller the deviation amount D, the more preferable, and the lower limit of the deviation amount D is 10 μm in one embodiment and 20 μm in another embodiment. The amount of deviation D refers to the maximum portion of the polarizing plate that moves away from the through-hole portion when viewed in cross section. The reference for the through-hole portion can typically be the lower end of the pressure-sensitive adhesive layer. That is, when the polarizing plate shifts mainly due to the shrinkage of the polarizer 11 (to the right in the illustrated example), the pressure-sensitive adhesive layer 20 stays on the adhered glass plate 120, so that the through-hole portion is recognized as being displaced. It will be. As shown in FIG. 3, the polarizing plate is typically displaced to the side away from the through hole in the through hole portion (right side of FIG. 3), and the opposite portion is displaced so as to protrude into the through hole (FIG. 3). 3 left side). As described above, according to the embodiment of the present invention, it is possible to solve the newly discovered problem of the displacement of the polarizing plate (substantially, the displacement of the pressure-sensitive adhesive layer) at the through-hole portion in a high temperature environment. Specifically, the amount of deviation D after a predetermined heating test can be set within the above range.

In the embodiment of the present invention, the dimensional shrinkage of the polarizing plate after the heating test is preferably 1.0% or less, more preferably 0.6% or less, still more preferably 0.3% or less. Is. The smaller the dimensional shrinkage, the more preferable, and the lower limit of the dimensional shrinkage can be, for example, 0.01%. The dimensional shrinkage rate is calculated by the following formula. The dimensional shrinkage is the dimensional shrinkage of the entire polarizing plate attached to the glass plate, and when the polarizing plate further has an optical functional layer (for example, a retardation layer and a reflective polarizing element) as described later. Means the dimensional shrinkage rate of the entire polarizing plate including the optical functional layer. The "dimension" in the following formula is the dimension in the absorption axis direction of the polarizing plate (substantially, the polarizer).
Dimension shrinkage rate (%) = {(dimensions before heating test-dimensions after heating test) / dimensions before heating test} x 100

The diameter R of the through hole 30 is preferably 10 mm or less, more preferably 8 mm or less, and further preferably 5 mm or less. The lower limit of the diameter of the through hole can be, for example, 2 mm, and can be, for example, 1.5 mm. The ratio D / R of the deviation amount D to the diameter R of the through hole is preferably 15% or less, more preferably 10% or less, further preferably 6% or less, and particularly preferably 5% or less. .. On the other hand, the smaller the lower limit of D / R, the more preferable. According to the embodiment of the present invention, since the deviation amount D is very small as described above, the D / R can be set in such a range even if the diameter of the through hole is reduced. Therefore, even if the diameter of the through hole is reduced, the adverse effect on the camera performance can be substantially prevented. As a result, the polarizing plate according to the embodiment of the present invention can be applied to an image display device and / or a bezel-less image display device in which only the camera unit is a non-display area.

In one embodiment, the polarizing plate preferably satisfies the following relationship:
(A × T _pol ) × (C _psa × T _psa ) / T _pro = K ≦ 350 × 10 ² (μm ³ / hr)
Here, A is the distance (μm) from the outermost part of the pressure-sensitive adhesive layer 20 in the thickness direction to the center of the polarizer 11 in the thickness direction; T _pol is the thickness of the polarizer (μm); C _psa is The creep value of the pressure-sensitive adhesive layer (μm / hr); T _psa is the thickness of the pressure-sensitive adhesive layer (μm); T _pro is the thickness of the protective layer (μm). As used herein, the term "creep value" means a creep value at 85 ° C. The creep value can be measured, for example, by the following procedure: the adhesive constituting the adhesive layer is attached to the support plate. With the support plate to which the adhesive is attached fixed, a load of 500 g is applied vertically downward. The amount of displacement of the adhesive from the support plate 1 hour after the load is applied is measured, and the amount of displacement is defined as the creep value (μm / hr). Further, the thickness T _pro of the protective layer in the above relational expression is obtained from the formula: "total thickness of polarizing plate-thickness of adhesive layer-thickness of polarizer". That is, T _pro is a case where the total thickness of the protective layer 12 and the protective layer 13 and the thickness of the adhesive layer for attaching the protective layer (when the polarizer or the protective film and the reflective polarizer are adhered via the adhesive layer). It is the total thickness of (including the pressure-sensitive adhesive layer) and the thickness of the surface treatment layer formed on the protective layer 12 as needed. The K value is more preferably 250 × 10 ² (μm ³ / hr) or less, further preferably 200 × 10 ² (μm ³ / hr) or less, and particularly preferably 150 × 10 ² (μm ³ / hr) or less. ) It is as follows. The lower limit of the K value can be, for example, 15 × 10 ² (μm ³ / hr). When the K value is in such a range, the displacement of the through-hole portion (substantially, the displacement of the pressure-sensitive adhesive layer) can be remarkably suppressed. The technical meaning of setting the K value to a predetermined value or less is as follows: The displacement of the pressure-sensitive adhesive layer increases when the moment force applied to the pressure-sensitive adhesive layer and the mobility of the pressure-sensitive adhesive layer itself are large, and the pressure-sensitive adhesive layer The greater the deterrent to the movement of, the smaller it becomes. The moment force applied to the pressure-sensitive adhesive layer may be related to the distance from the image display cell to which the polarizing plate is attached to the polarizer and the thickness of the polarizer; the ease of movement of the pressure-sensitive adhesive layer itself is the softness of the pressure-sensitive adhesive layer. And thickness can be related; the deterrent to the movement of the pressure-sensitive adhesive layer can be related to the thickness of the protective layer. The moment force can be reduced by reducing the distance from the image display cell to the polarizer and the thickness of the polarizer; the creep value of the adhesive layer is set to a predetermined value or less (the adhesive layer is made hard). In addition, by reducing the thickness of the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer itself can be made difficult to move; by setting the thickness _{Tpro of the} protective layer within a predetermined range, the deterrent force against the movement of the pressure-sensitive adhesive layer is appropriate. Can be a range. Therefore, by adjusting each of the above requirements and controlling the K value to a predetermined value or less, the displacement of the pressure-sensitive adhesive layer can be remarkably suppressed. Specifically, the above distance A is preferably 80 μm or less, and more preferably 50 μm or less. The lower limit of the distance A can be, for example, 10 μm. The creep value C _psa is preferably 140 μm / hr or less, more preferably 130 μm / hr or less, still more preferably 120 μm / hr or less, and particularly preferably 100 μm / hr or less. The lower limit of the creep value can be, for example, 50 μm / hr. The thickness T _{pro of the} protective layer is preferably 15 μm to 65 μm, and more preferably 15 μm to 55 μm. The thickness T _psa of the pressure-sensitive adhesive layer is preferably 22 μm or less, and more preferably 10 μm to 22 μm. If the creep value C _psa is too small and / or the thickness T _psa of the pressure-sensitive adhesive layer is too small, stress relaxation may be difficult and the risk of cracking or peeling may increase. If the thickness T _{pro of the} protective layer is too small, it may be difficult to adjust the curl.

In the embodiment of the present invention, the thickness T _pol of the polarizer 11 is preferably 20 μm or less, more preferably 15 μm or less, still more preferably 12 μm or less, particularly preferably 10 μm or less, and even more particularly. It is preferably 8 μm or less, particularly preferably 6 μm or less, and most preferably 5 μm or less. The lower limit of the thickness of the polarizer 11 is preferably 2 μm, more preferably 1 μm. By setting the thickness of the polarizer in such a range, it is possible to suppress the thermal shrinkage of the polarizer itself. As a result, deformation (resulting in displacement) of the pressure-sensitive adhesive layer that can follow the heat shrinkage of the polarizer can be suppressed.

When the polarizing plate has a rectangular shape as described above, the absorption axis direction of the polarizer may be substantially parallel to the longitudinal direction or substantially orthogonal to the longitudinal direction. According to the embodiment of the present invention, the amount of displacement of the polarizing plate can be reduced as described above even when the absorption axis direction of the polarizer is substantially parallel to the longitudinal direction. In other words, according to the embodiment of the present invention, the amount of displacement can be reduced even in the direction in which the heat shrinkage of the polarizing plate (substantially, the polarizer) is large. Further, as described above, the through holes may be provided at the corners of the polarizing plate. The corner portion is a portion where the heat shrinkage of the polarizing plate (substantially, the polarizer) is large. However, according to the embodiment of the present invention, the amount of displacement of the polarizing plate is also determined in such a portion as described above. It can be made smaller. In the present specification, the expressions "substantially parallel" and "substantially parallel" include the case where the angle formed by the two directions is 0 ° ± 7 °, preferably 0 ° ± 5 °. More preferably, it is 0 ° ± 3 °. The expressions "substantially orthogonal" and "substantially orthogonal" include the case where the angle between the two directions is 90 ° ± 7 °, preferably 90 ° ± 5 °, and even more preferably 90 ° ±. It is 3 °. Further, the term "orthogonal" or "parallel" in the present specification may include substantially orthogonal or substantially parallel states. Also, when referring to an angle herein, it includes both clockwise and counterclockwise with respect to the reference direction.

The polarizing plate according to the embodiment of the present invention may be used as a viewing side polarizing plate or a back side polarizing plate. Further, the polarizing plate according to the embodiment of the present invention may further have an arbitrary appropriate optical functional layer depending on the intended purpose. Examples of the optical functional layer include a retardation layer, a conductive layer for a touch panel, and a reflective polarizer.

In one embodiment, a retardation layer may be provided between the inner protective layer 13 and the pressure-sensitive adhesive layer 20. The retardation layer may be composed of a single layer or may have a laminated structure. When the retardation layer is composed of a single layer, the retardation layer can typically function as a λ / 4 plate. In this case, the in-plane retardation Re (550) of the retardation layer is preferably 100 nm to 200 nm, more preferably 120 nm to 170 nm, and even more preferably 130 nm to 150 nm. The angle formed by the absorption axis of the polarizer and the slow axis of the retardation layer is preferably 40 ° to 50 °, more preferably 42 ° to 48 °, and even more preferably 44 ° to 46 °. .. The retardation layer preferably exhibits a reverse dispersion wavelength characteristic in which the retardation value increases with the wavelength of the measurement light. In this case, Re (450) / Re (550) of the retardation layer is preferably 0.8 or more and less than 1, and more preferably 0.8 or more and 0.95 or less. The retardation layer may be a stretched film of a resin film or an orientation-solidified layer of a liquid crystal compound. When the retardation layer is made of a resin film, the retardation layer may also serve as an inner protective layer. The retardation layer composed of a stretched film of a resin film is described in, for example, JP-A-2017-54093 and JP-A-2018-60014. Specific examples of the liquid crystal compound and details of the method for forming the oriented solidified layer are described in, for example, Japanese Patent Application Laid-Open No. 2006-163343. The descriptions in these publications are incorporated herein by reference. In the present specification, “Re (λ)” is an in-plane phase difference measured with light having a wavelength of λ nm at 23 ° C. For example, "Re (550)" is an in-plane phase difference measured with light having a wavelength of 550 nm at 23 ° C. Re (λ) is obtained by the formula: Re (λ) = (nx−ny) × d, where d (nm) is the thickness of the layer (film). nx is the refractive index in the direction in which the in-plane refractive index is maximized (that is, the slow-phase axis direction), and ny is the refractive index in the in-plane direction orthogonal to the slow-phase axis (that is, the phase-advancing axis direction). is there.

When the retardation layer has a laminated structure, the retardation layer typically has an H layer and a Q layer in order from the polarizing plate side. The H layer can typically function as a λ / 2 plate, and the Q layer can typically function as a λ / 4 plate. The Re (550) of the H layer is preferably 200 nm to 300 nm, more preferably 230 nm to 290 nm, and even more preferably 260 nm to 280 nm. The angle formed by the absorption axis of the polarizer and the slow axis of the H layer is preferably 10 ° to 20 °, more preferably 12 ° to 18 °, and even more preferably 14 ° to 16 °. The Re (550) of the Q layer is preferably 100 nm to 200 nm, more preferably 120 nm to 170 nm, and further preferably 130 nm to 150 nm. The angle formed by the absorption axis of the polarizer and the slow axis of the Q layer is preferably 70 ° to 80 °, more preferably 72 ° to 78 °, and even more preferably 74 ° to 76 °. The arrangement order of the H layer and the Q layer may be reversed, and the angle formed by the slow axis of the H layer and the absorption axis of the polarizer and the angle formed by the slow axis of the Q layer and the absorption axis of the polarizer are The reverse may be true. Each of the H layer and the Q layer may be a stretched film of a resin film or an orientation-solidified layer of a liquid crystal compound.

In one embodiment, a touch panel conductive layer may be provided on the opposite side of the inner protective layer 13 (if present, a retardation layer) to the polarizer. With such a configuration, the polarizing plate can be applied to a so-called inner touch panel type input display device in which a touch sensor is incorporated between the image display cell and the polarizing plate. The polarizing plate of this embodiment is typically a viewing side polarizing plate.

In one embodiment, a reflective polarizer may be provided on the opposite side of the outer protective layer 12 from the polarizer. The reflective polarizer may also serve as an outer protective layer. The polarizing plate of this embodiment is typically a backside polarizing plate. Details of the reflective polarizer are described in, for example, Japanese Patent Application Laid-Open No. 9-507308 and Japanese Patent Application Laid-Open No. 2013-235259. The description of these publications is incorporated herein by reference.

The polarizing plate according to the embodiment of the present invention preferably has an aspect ratio of 1.3 to 2.5. In this case, the size of the polarizing plate is, for example, 145 mm to 155 mm in length and 65 mm to 75 mm in width, or 230 mm to 240 mm in length and 140 mm to 150 mm in width. That is, the polarizing plate according to the embodiment of the present invention can be suitably used for a smartphone or a tablet PC. The smartphone size may be, for example, 120 mm to 200 mm in length and 30 mm to 120 mm in width.

Hereinafter, the polarizer, the protective layer, and the pressure-sensitive adhesive layer constituting the polarizing plate will be specifically described.

B. Polarizing plate B-1. Polarizer The polarizer is typically composed of a resin film containing a dichroic substance. As the resin film, any suitable resin film that can be used as a polarizer can be adopted. The resin film is typically a polyvinyl alcohol-based resin (hereinafter, referred to as “PVA-based resin”) film. The resin film may be a single-layer resin film or a laminated body having two or more layers.

Specific examples of the polarizer composed of a single-layer resin film include those obtained by subjecting a PVA-based resin film to a dyeing treatment with iodine and a stretching treatment (typically, uniaxial stretching). The dyeing with iodine is performed, for example, by immersing a PVA-based resin film in an aqueous iodine solution. The draw ratio of the uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after the dyeing treatment or while dyeing. Moreover, you may dye after stretching. If necessary, the PVA-based resin film is subjected to a swelling treatment, a cross-linking treatment, a cleaning treatment, a drying treatment and the like. For example, by immersing the PVA-based resin film in water and washing it with water before dyeing, it is possible not only to clean the surface of the PVA-based resin film and the blocking inhibitor, but also to swell and dye the PVA-based resin film. It is possible to prevent unevenness and the like.

Specific examples of the polarizer obtained by using the laminate include a laminate of a resin base material and a PVA-based resin layer (PVA-based resin film) laminated on the resin base material, or a resin base material and the resin. Examples thereof include a polarizer obtained by using a laminate with a PVA-based resin layer coated and formed on a base material. The polarizer obtained by using the laminate of the resin base material and the PVA-based resin layer coated and formed on the resin base material is, for example, a resin base material obtained by applying a PVA-based resin solution to the resin base material and drying it. It is produced by forming a PVA-based resin layer on the PVA-based resin layer to obtain a laminate of a resin base material and a PVA-based resin layer; stretching and dyeing the laminate to make the PVA-based resin layer a polarizer. obtain. In the present embodiment, stretching typically includes immersing the laminate in an aqueous boric acid solution for stretching. Further, stretching may further include, if necessary, stretching the laminate in the air at a high temperature (eg, 95 ° C. or higher) prior to stretching in boric acid aqueous solution. The obtained resin base material / polarizer laminate may be used as it is (that is, the resin base material may be used as a protective layer for the polarizer), and the resin base material is peeled off from the resin base material / polarizer laminate. Then, an arbitrary appropriate protective layer according to the purpose may be laminated on the peeled surface. Details of the method for producing such a polarizer are described in, for example, Japanese Patent Application Laid-Open No. 2012-73580 and Japanese Patent No. 6470455. The description of these patent documents is incorporated herein by reference.

The thickness of the polarizer is as described in the above item A.

The polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The simple substance transmittance of the polarizer is, for example, 41.5% to 46.0%, preferably 43.0% to 46.0%, and more preferably 44.5% to 46.0%. The degree of polarization of the polarizer is preferably 97.0% or more, more preferably 99.0% or more, and further preferably 99.9% or more.

B-2. Protective layer The protective layer is formed of any suitable film that can be used as a protective layer for the polarizer. Specific examples of the material that is the main component of the film include cellulose-based resins such as triacetylcellulose (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, and polysulfone-based. , Polystyrene-based, polycarbonate-based, polyolefin-based, (meth) acrylic-based, acetate-based transparent resins and the like. Further, thermosetting resins such as (meth) acrylic, urethane, (meth) acrylic urethane, epoxy, and silicone, or ultraviolet curable resins can also be mentioned. In addition to this, for example, glassy polymers such as siloxane-based polymers can also be mentioned. Further, the polymer film described in JP-A-2001-343529 (WO01 / 37007) can also be used. As the material of this film, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain. Can be used, and examples thereof include a resin composition having an alternating copolymer composed of isobutene and N-methylmaleimide and an acrylonitrile / styrene copolymer. The polymer film can be, for example, an extruded product of the above resin composition.

Even if the outer protective layer 12 (particularly when the polarizing plate is a viewing side polarizing plate) is subjected to surface treatment such as hard coating treatment, antireflection treatment, anti-sticking treatment, anti-glare treatment, etc., if necessary. Good. Further / or, if necessary, the outer protective layer 12 is provided with a process for improving visibility when visually recognizing through polarized sunglasses (typically, a (elliptical) circularly polarized light function is provided, and an ultra-high position is provided. (Giving a phase difference) may be applied. By performing such processing, excellent visibility can be realized even when the display screen is visually recognized through a polarized lens such as polarized sunglasses. Therefore, the polarizing plate can also be suitably applied to an image display device that can be used outdoors.

The inner protective layer is preferably optically isotropic. In the present specification, "optically isotropic" means that the in-plane retardation Re (550) is 0 nm to 10 nm and the thickness direction retardation Rth (550) is -10 nm to +10 nm. Say. Here, "Rth (λ)" is a phase difference in the thickness direction measured with light having a wavelength of λ nm at 23 ° C. For example, "Rth (550)" is a phase difference in the thickness direction measured with light having a wavelength of 550 nm at 23 ° C. Rth (λ) is obtained by the formula: Rth (λ) = (nx−nz) × d, where d (nm) is the thickness of the layer (film). nz is the refractive index in the thickness direction.

Any suitable thickness can be adopted as the thickness of the protective layer. The thickness of the protective layer is, for example, 10 μm to 50 μm, preferably 20 μm to 40 μm. When the surface treatment is applied, the thickness of the protective layer is the thickness including the thickness of the surface treatment layer. The "thickness of the protective layer" referred to here is the thickness of each of the outer protective layer and the inner protective layer, and is different from T _pro in the above formula.

C. Adhesive layer The adhesive layer 20 is used to attach the polarizing plate to the image display cell as described above. The pressure-sensitive adhesive layer may be typically composed of an acrylic pressure-sensitive adhesive (acrylic pressure-sensitive adhesive composition). The acrylic pressure-sensitive adhesive composition typically contains a (meth) acrylic polymer as a main component. The (meth) acrylic polymer can be contained in the pressure-sensitive adhesive composition in a proportion of, for example, 50% by weight or more, preferably 70% by weight or more, and more preferably 90% by weight or more in the solid content of the pressure-sensitive adhesive composition. The (meth) acrylic polymer contains an alkyl (meth) acrylate as a main component as a monomer unit. In addition, (meth) acrylate means acrylate and / or methacrylate. The alkyl (meth) acrylate can be contained in a proportion of preferably 80% by weight or more, more preferably 90% by weight or more, in the monomer component forming the (meth) acrylic polymer. Examples of the alkyl group of the alkyl (meth) acrylate include a linear or branched alkyl group having 1 to 18 carbon atoms. The average number of carbon atoms of the alkyl group is preferably 3 to 9, and more preferably 3 to 6. A preferred alkyl (meth) acrylate is butyl acrylate. As the monomer (copolymerization monomer) constituting the (meth) acrylic polymer, in addition to the alkyl (meth) acrylate, a carboxyl group-containing monomer, a hydroxyl group-containing monomer, an amide group-containing monomer, an aromatic ring-containing (meth) acrylate, and a complex Examples include ring-containing vinyl-based monomers. Representative examples of the copolymerization monomer include acrylic acid, 4-hydroxybutyl acrylate, phenoxyethyl acrylate, and N-vinyl-2-pyrrolidone. The acrylic pressure-sensitive adhesive composition may preferably contain a silane coupling agent and / or a cross-linking agent. Examples of the silane coupling agent include an epoxy group-containing silane coupling agent. Examples of the cross-linking agent include isocyanate-based cross-linking agents and peroxide-based cross-linking agents. Furthermore, the acrylic pressure-sensitive adhesive composition may contain an antioxidant and / or a conductive agent. The thickness T _psa of the pressure-sensitive adhesive layer is, for example, 50 μm or less, and as described above, it is preferably 22 μm or less, and more preferably 10 μm to 22 μm. Details of the pressure-sensitive adhesive layer or the acrylic pressure-sensitive adhesive composition are described in, for example, JP-A-2006-183022, JP-A-2015-199942, JP-A-2018-053114, JP-A-2016-19996, International Publication. It is described in No. 2018/008712, and the description of these publications is incorporated herein by reference.

Storage modulus _{G 2} at -40 ℃ of the adhesive layer 'is preferably 1.0 × ¹⁰ 5 (Pa) or more, more preferably 1.0 × ¹⁰ 6 (Pa) or more, more preferably It is 1.0 × 10 ⁷ (Pa) or more, and particularly preferably 1.0 × 10 ⁸ (Pa) or more. Storage modulus _{G 2} 'may be, for example, 1.0 × ¹⁰ 9 (Pa) or less.

D. Image Display Device The polarizing plate according to the embodiment of the present invention can be applied to an image display device. Therefore, image display devices are also included in the embodiments of the present invention. The image display device includes an image display cell and a polarizing plate. The polarizing plate is a polarizing plate according to the embodiment of the present invention according to the above items A to C. The polarizing plate is attached to the image display cell via the pressure-sensitive adhesive layer. Examples of the image display device include a liquid crystal display device, an organic electroluminescence (EL) display device, and a quantum dot display device.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. The evaluation items in the examples are as follows. Further, unless otherwise specified, "parts" and "%" in the examples are based on weight.

(1) Amount of deviation The polarizing plates obtained in Examples and Comparative Examples were attached to a glass plate (manufactured by Matsunami Glass Co., Ltd., length 350 mm × width 250 mm × thickness 1.1 mm) via an adhesive layer to form a test sample. did. This test sample was subjected to a heating test at 85 ° C. and 120 hours. After the test, the amount of displacement of the polarizing plate (substantially the adhesive layer) in the through-hole portion was measured with an optical microscope (MX61L) manufactured by OLYMPUS. The measurement was performed on three test samples, and the maximum value among the three measured values was taken as the deviation amount.

<Manufacturing example 1>
A monomer mixture containing 99 parts of butyl acrylate and 1 part of 4-hydroxybutyl acrylate was charged into a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler. Further, with respect to 100 parts of the monomer mixture (solid content), 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator was charged together with 100 parts by weight of ethyl acetate, and nitrogen gas was added while gently stirring. After the introduction and nitrogen substitution, the liquid temperature in the flask was maintained at around 55 ° C. and the polymerization reaction was carried out for 8 hours to prepare a solution of the acrylic polymer (a) having a weight average molecular weight (Mw) of 1.56 million. With respect to 100 parts of the solid content of the obtained solution of the acrylic polymer (a), 0.1 part of an isocyanate cross-linking agent (trade name: Takenate D160N, trimethylolpropane hexamethylene diisocyanate, manufactured by Mitsui Chemicals, Inc.), benzoyl Peroxide (trade name: Niper BMT 40SV, manufactured by Nippon Oil & Fats Co., Ltd.) 0.3 part, thiol group-containing silane coupling agent (trade name: X-41-1810, manufactured by Shin-Etsu Chemical Industry Co., Ltd., alkoxy group amount : 30%, thiol equivalent: 450 g / mol) 0.3 part and antioxidant (trade name: Irganox 1010, hindered phenol type, manufactured by BASF Japan) 0.2 part are blended to form a pressure-sensitive adhesive. I got thing A.

<Manufacturing example 2>
A monomer mixture containing 81.8 parts of butyl acrylate, 16 parts of phenoxyethyl acrylate, 1.5 parts of N-vinyl-2-pyrrolidone, 0.3 parts of acrylic acid and 0.4 parts of 4-hydroxybutyl acrylate was used. A solution of an acrylic polymer (b) having a weight average molecular weight (Mw) of 1.57 million was prepared in the same manner as in Production Example 1 except for the above. Acrylic polymer (b) was used, and a thiol group-containing silane coupling agent (trade name: X-41-1056, manufactured by Shin-Etsu Chemical Co., Ltd., alkoxy group amount: 30%, thiol equivalent) was used as the silane coupling agent. : 450 g / mol) 0.2 parts was used, no antioxidant was used, and 0.5 parts of bis (trifluoromethanesulfonyl) imidelithium (manufactured by Mitsubishi Materials) was added. The pressure-sensitive adhesive composition B was obtained in the same manner as in Production Example 1.

<Manufacturing example 3>
Except for using a monomer mixture containing 80.3 parts of butyl acrylate, 16 parts of phenoxyethyl acrylate, 3 parts of N-vinyl-2-pyrrolidone, 0.3 parts of acrylic acid and 0.4 parts of 4-hydroxybutyl acrylate. A solution of an acrylic polymer (c) having a weight average molecular weight (Mw) of 1.5 million was prepared in the same manner as in Production Example 1. The acrylic polymer (c) was used, the blending amount of the silane coupling agent was 0.1 part, and the conductive agent (1-ethyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide, No. 1 The pressure-sensitive adhesive composition C was obtained in the same manner as in Production Example 1 except that 5 parts of an ionic liquid manufactured by Ichi Kogyo Seiyaku Co., Ltd. was added.

<Manufacturing example 4>
A solution of an acrylic polymer (d) having a weight average molecular weight (Mw) of 1.65 million was prepared in the same manner as in Production Example 1. With respect to 100 parts of the solid content of the obtained solution of the acrylic polymer (d), 0.1 part of an isocyanate cross-linking agent (trade name: Takenate D110N, trimethylolpropane hexamethylene diisocyanate, manufactured by Mitsui Chemicals, Inc.), benzoyl 0.3 parts of peroxide (trade name: Niper BMT 40SV, manufactured by Nippon Oil & Fats Co., Ltd.) and 0.2 parts of acetacetyl group-containing silane coupling agent (trade name: A-100, manufactured by Soken Kagaku Co., Ltd.) It was blended to obtain a pressure-sensitive adhesive composition D.

<Production example 5>
As a silane coupling agent, 0.2 part of a thiol group-containing silane coupling agent (trade name: X-41-1810, manufactured by Shin-Etsu Chemical Co., Ltd., alkoxy group amount: 30%, thiol equivalent: 450 g / mol) is used. A pressure-sensitive adhesive composition E was obtained in the same manner as in Production Example 1 except that the adhesive composition E was obtained.

<Example 1>
As the thermoplastic resin base material, an amorphous isophthal copolymer polyethylene terephthalate film (thickness: 100 μm) having a Tg of about 75 ° C. was used, and one side of the resin base material was subjected to corona treatment.
100 parts by weight of PVA-based resin in which polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gosefimmer") are mixed at a ratio of 9: 1. A PVA aqueous solution (coating solution) was prepared by dissolving 13 parts by weight of potassium iodide in water.
A PVA-based resin layer having a thickness of 13 μm was formed by applying the above PVA aqueous solution to the corona-treated surface of the resin base material and drying at 60 ° C. to prepare a laminate.
The obtained laminate was uniaxially stretched 2.4 times in the longitudinal direction (longitudinal direction) in an oven at 130 ° C. (aerial auxiliary stretching treatment).
Next, the laminate was immersed in an insolubilizing bath at a liquid temperature of 40 ° C. (an aqueous boric acid solution obtained by blending 4 parts by weight of boric acid with 100 parts by weight of water) for 30 seconds (insolubilization treatment).
Next, in a dyeing bath having a liquid temperature of 30 ° C. (an aqueous iodine solution obtained by mixing iodine and potassium iodide in a weight ratio of 1: 7 with respect to 100 parts by weight of water), the polarizer finally obtained Immersion was carried out for 60 seconds while adjusting the concentration so that the simple substance transmittance (Ts) became a desired value (staining treatment).
Next, it was immersed in a cross-linked bath at a liquid temperature of 40 ° C. (an aqueous boric acid solution obtained by blending 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with respect to 100 parts by weight of water) for 30 seconds. (Crossing treatment).
Then, while immersing the laminate in a boric acid aqueous solution (boric acid concentration 4% by weight, potassium iodide concentration 5% by weight) at a liquid temperature of 70 ° C., the total in the longitudinal direction (longitudinal direction) between rolls having different peripheral speeds. Uniaxial stretching was performed so that the stretching ratio was 5.5 times (underwater stretching treatment).
Then, the laminate was immersed in a washing bath at a liquid temperature of 20 ° C. (an aqueous solution obtained by blending 4 parts by weight of potassium iodide with 100 parts by weight of water) (cleaning treatment).
Then, while drying in an oven kept at about 90 ° C., it was brought into contact with a heating roll made of SUS whose surface temperature was kept at about 75 ° C. (dry shrinkage treatment).
In this way, a polarizer having a thickness of about 5 μm was formed on the resin substrate, and a laminate having a resin substrate / polarizer configuration was obtained.
An HC-TAC film was attached as an outer protective layer to the polarizer surface (the surface opposite to the resin base material) of the obtained laminate. The HC-TAC film is a triacetyl cellulose (TAC) film (thickness 25 μm) on which a hard coat (HC) layer (thickness 7 μm) is formed, and is attached so that the TAC film is on the polarizer side. I matched it. Next, the resin base material was peeled off, and a pressure-sensitive adhesive layer (thickness 20 μm) was formed on the peeled surface using the pressure-sensitive adhesive composition A to obtain a polarizing plate 1.
This polarizing plate was punched to a size of 148 mm in length and 70 mm in width, and a through hole having a diameter of 3.9 mm was further formed at a corner. At this time, punching was performed so that the absorption axis direction of the polarizer was the longitudinal direction. The obtained polarizing plate was subjected to the evaluation of (1) above. The results are shown in Table 1 together with the detailed configuration of the polarizing plate. In Table 1, "0 °" means the longitudinal direction, and "90 °" means the lateral direction.

<Example 2>
Polarizing plate 1 was obtained in the same manner as in Example 1. This polarizing plate was punched in the same manner as in Example 1 except that the absorption axis direction of the polarizer was in the lateral direction to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 3>
A polarizing plate 2 was obtained in the same manner as in Example 1 except that the thickness of the pressure-sensitive adhesive layer was 15 μm. This polarizing plate was punched in the same manner as in Example 1 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 4>
Polarizing plate 2 was obtained in the same manner as in Example 3. This polarizing plate was punched in the same manner as in Example 2 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 5>
A laminate having a resin base material / polarizer configuration was obtained in the same manner as in Example 1. An HC-cycloolefin resin film (HC thickness 2 μm, resin film thickness 25 μm) was laminated as an outer protective layer on the polarizer surface (the surface opposite to the resin base material) of the obtained laminate. Next, the resin base material was peeled off, and a cycloolefin resin film (thickness 13 μm) was attached to the peeled surface as an inner protective layer. Further, a pressure-sensitive adhesive layer (thickness 20 μm) was formed on the surface of the inner protective layer using the pressure-sensitive adhesive composition A to obtain a polarizing plate 3. This polarizing plate was punched in the same manner as in Example 1 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 6>
A polarizing plate 3 was obtained in the same manner as in Example 5. This polarizing plate was punched in the same manner as in Example 2 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 7>
As the polarizer, a film (thickness 12 μm) obtained by adding iodine to a long polyvinyl alcohol (PVA) -based resin film and uniaxially stretching it in the longitudinal direction (MD direction) was used. A long HC-TAC film serving as an outer protective layer and a long acrylic resin film (thickness 20 μm) serving as an inner protective layer are attached to both sides of the polarizer so as to align their longitudinal directions with each other. I matched it. A pressure-sensitive adhesive layer (thickness 20 μm) was formed on the surface of the inner protective layer using the pressure-sensitive adhesive composition B to obtain a polarizing plate 4. This polarizing plate was punched in the same manner as in Example 1 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 8>
A polarizing plate 4 was obtained in the same manner as in Example 7. This polarizing plate was punched in the same manner as in Example 2 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 9>
A cycloolefin resin film (thickness 13 μm) was used instead of the acrylic resin film as the inner protective layer, and a pressure-sensitive adhesive composition C was used instead of the pressure-sensitive adhesive composition B (thickness 20 μm). A polarizing plate 5 was obtained in the same manner as in Example 7 except that This polarizing plate was punched in the same manner as in Example 1 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 10>
A polarizing plate 5 was obtained in the same manner as in Example 9. This polarizing plate was punched in the same manner as in Example 2 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 11>
A polarizing plate was obtained in the same manner as in Example 7 except that a TAC film (thickness 25 μm) was used instead of the acrylic resin film as the inner protective layer. The liquid crystal oriented solidified layer H and the liquid crystal oriented solidified layer Q were sequentially transferred to the inner protective layer side of the polarizing plate. The liquid crystal oriented solidified layer H and the liquid crystal oriented solidified layer Q were produced as follows. A pressure-sensitive adhesive layer (thickness 20 μm) was formed on the surface of the liquid crystal oriented solidified layer Q using the pressure-sensitive adhesive composition D to obtain a polarizing plate (polarizing plate with a retardation layer) 6. This polarizing plate was punched in the same manner as in Example 2 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

10 g of a polymerizable liquid crystal showing a nematic liquid crystal phase (BASF: trade name "Pariocolor LC242", represented by the following formula) and a photopolymerization initiator (BASF: trade name "Irgacure 907") for the polymerizable liquid crystal compound ”) 3 g was dissolved in 40 g of toluene to prepare a liquid crystal composition (coating liquid).
The surface of a polyethylene terephthalate (PET) film (thickness 38 μm) was rubbed with a rubbing cloth and subjected to an orientation treatment. The direction of the alignment treatment was set to be 15 ° when viewed from the visual side with respect to the direction of the absorption axis of the polarizer when the polarizing plate was attached. The liquid crystal coating liquid was applied to the alignment-treated surface with a bar coater, and the liquid crystal compound was oriented by heating and drying at 90 ° C. for 2 minutes. The liquid crystal layer thus formed was irradiated with light of 1 mJ / cm ² using a metal halide lamp, and the liquid crystal layer was cured to form a liquid crystal oriented solidified layer H on the PET film. The thickness of the liquid crystal oriented solidified layer H was 2.5 μm, and the in-plane retardation Re (550) was 270 nm. Further, the liquid crystal oriented solidified layer H had a refractive index distribution of nx> ny = nz.
On the PET film in the same manner as above, except that the coating thickness was changed and the orientation treatment direction was set to be 75 ° when viewed from the visual side with respect to the direction of the absorber's absorption axis. A liquid crystal oriented solidified layer Q was formed. The thickness of the liquid crystal oriented solidified layer Q was 1.5 μm, and the in-plane retardation Re (550) was 140 nm. Further, the liquid crystal oriented solidified layer Q had a refractive index distribution of nx> ny = nz.

<Example 12>
A polarizing plate was obtained in the same manner as in Example 7 except that a TAC film (thickness 25 μm) was used instead of the HC-TAC film as the outer protective layer. Further, a reflective polarizing element (thickness 26 μm) is attached to the surface of the outer protective layer via a normal adhesive layer, and the pressure-sensitive adhesive layer (thickness 20 μm) is used on the surface of the reflective polarizing element using the pressure-sensitive adhesive composition E. Was formed to obtain a polarizing plate 7. This polarizing plate was punched in the same manner as in Example 1 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 13>
A polarizing plate 7 was obtained in the same manner as in Example 12. This polarizing plate was punched in the same manner as in Example 2 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 14>
A laminate having a resin base material / polarizer configuration was obtained in the same manner as in Example 1. A TAC film (thickness 20 μm) was attached as an inner protective layer to the polarizer surface (the surface opposite to the resin base material) of the obtained laminate. Next, the resin base material was peeled off, and a reflective polarizer (thickness 26 μm) was attached to the peeled surface. A pressure-sensitive adhesive layer (thickness 20 μm) was formed on the surface of the inner protective layer using the pressure-sensitive adhesive composition D to obtain a polarizing plate 8. This polarizing plate was punched in the same manner as in Example 1 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 15>
A polarizing plate 8 was obtained in the same manner as in Example 14. This polarizing plate was punched in the same manner as in Example 2 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Comparative example 1>
As the polarizer, a film (thickness 22 μm) obtained by containing iodine in a long polyvinyl alcohol (PVA) -based resin film and uniaxially stretching it in the longitudinal direction (MD direction) was used. A long TAC film (thickness 40 μm) serving as an outer protective layer and a long acrylic resin film (thickness 30 μm) serving as an inner protective layer are aligned on both sides of the polarizing element in their longitudinal directions. And pasted together. A pressure-sensitive adhesive layer (thickness 20 μm) was formed on the surface of the inner protective layer using the pressure-sensitive adhesive composition D to obtain a polarizing plate 9. This polarizing plate was punched in the same manner as in Example 1 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Comparative example 2>
A polarizing plate 9 was obtained in the same manner as in Comparative Example 1. This polarizing plate was punched in the same manner as in Example 2 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 16>
Polarizing plate 1 was obtained in the same manner as in Example 1. The polarizing plate was punched to a size of 152 mm in length and 73 mm in width, and a through hole having a diameter of 4.7 mm was formed in the center of the end portion in the longitudinal direction. At this time, punching was performed so that the absorption axis direction of the polarizer was the longitudinal direction. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 17>
A polarizing plate 3 was obtained in the same manner as in Example 5. This polarizing plate was punched in the same manner as in Example 16 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 18>
A polarizing plate 3 was obtained in the same manner as in Example 5. This polarizing plate was punched in the same manner as in Example 16 except that the absorption axis direction of the polarizer was in the lateral direction to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 19>
A polarizing plate 4 was obtained in the same manner as in Example 7. This polarizing plate was punched in the same manner as in Example 16 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Example 20>
A polarizing plate 10 was obtained in the same manner as in Example 9 except that the pressure-sensitive adhesive layer (thickness 20 μm) was formed by using the pressure-sensitive adhesive composition B instead of the pressure-sensitive adhesive composition C. This polarizing plate was punched in the same manner as in Example 18 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Comparative example 3>
A polarizing plate 9 was obtained in the same manner as in Comparative Example 1. This polarizing plate was punched in the same manner as in Example 16 to form a through hole. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1 together with the detailed configuration of the polarizing plate.

<Examples 21 to 28>
A polarizing plate having through holes was produced with the configuration shown in Table 1. The obtained polarizing plate was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

As is clear from Table 1, it can be seen that the polarizing plate of the example of the present invention has a significantly smaller amount of deviation in the through-hole portion after the heating test than that of the comparative example. Further, a graph showing the relationship between the K value and the amount of deviation for each of the polarizing plate having the absorption axis in the 0 ° direction (for example, Example 1) and the polarizing plate having the absorption axis in the 90 ° direction (for example, Example 2). Is shown in FIGS. 4 and 5. As is clear from FIGS. 4 and 5, it can be seen that the amount of deviation is reduced by reducing the K value, and that the relationship has a high correlation.

The polarizing plate of the present invention is suitably used for an image display device, and can be particularly preferably used for an image display device having a camera unit represented by a smartphone, a tablet PC or a smart watch.

11 Polarizer 12 Outer protective layer 13 Inner protective layer 20 Adhesive layer 30 Through hole 100 Polarizing plate

Claims (14)

A polarizing plate having a polarizing element, a protective layer arranged on at least one side of the polarizing element, and an adhesive layer.
A through hole is formed at or near the end,
The amount of displacement of the polarizing plate in the through-hole portion after being subjected to a heating test at 85 ° C. and 120 hours in a state where the polarizing plate is attached to a glass plate via the pressure-sensitive adhesive layer is 300 μm or less.
Polarizer. The distance A (μm) from the outermost part of the pressure-sensitive adhesive layer in the thickness direction to the central portion in the thickness direction of the polarizer, the thickness T _pol (μm) of the _{polarizer, and} the creep value C _psa (μm / hr) of the pressure-sensitive adhesive layer. ), The thickness T _psa (μm) of the pressure-sensitive adhesive layer, and the thickness T _pro (μm) of the protective layer satisfy the following relationship, the polarizing plate according to claim 1.
(A × T _pol ) × (C _psa × T _psa ) / T _pro = K ≦ 350 × 10 ² (μm ³ / hr). The polarizing plate according to claim 1 or 2, wherein the thickness T _{pol of the} polarizer is 20 μm or less. The polarizing plate according to claim 3, wherein the thickness T _{pol of the} polarizer is 10 μm or less. The polarizing plate according to claim 4, wherein the amount of displacement of the polarizing plate in the through-hole portion is 120 μm or less. The polarizing plate according to any one of claims 1 to 5, wherein the thickness T _psa of the pressure-sensitive adhesive layer is 10 μm to ₂₂ μm. The polarizing plate according to any one of claims 1 to 6, wherein the amount of displacement of the polarizing plate is substantially the amount of displacement of the pressure-sensitive adhesive layer. The polarizing plate according to any one of claims 1 to 7, wherein the through hole is formed in a corner portion. The distance from the center in the longitudinal direction to the end in the longitudinal direction when the polarizer is viewed in a plan view is L ₁ , the distance in the longitudinal direction from the center in the longitudinal direction to the center of the through hole is L ₂ , and the polarizer is When the distance from the center in the short direction to the end in the short direction is W ₁ , and the distance in the short direction from the center in the short direction to the center of the through hole of the polarizer is W ₂ , the through hole is The polarizing plate according to claim 8, wherein the polarizing plate is formed at a position satisfying 0.85 ≦ L ₂ / L ₁ ≦ 0.99 and 0.50 ≦ W ₂ / W ₁ ≦ 0.99. The polarizing plate according to any one of claims 1 to 9, which has a rectangular shape and whose absorption axis direction of the polarizer is substantially parallel to the longitudinal direction. The polarizing plate according to any one of claims 1 to 10, wherein the protective layer is arranged only on one side of the polarizer. The polarizing plate according to any one of claims 1 to 11, wherein the diameter of the through hole is 10 mm or less. The polarizing plate according to any one of claims 1 to 12, which has an aspect ratio of 1.3 to 2.5. The image display cell and the polarizing plate according to any one of claims 1 to 13 are included.
The polarizing plate is attached to the image display cell via the pressure-sensitive adhesive layer.
Image display device.