JP2021170144A - Circular polarizer - Google Patents

Abstract

To provide a circular polarizer that can suppress degradation of the uniformity of the color phase of a reflected light in a plane under a high-temperature environment.SOLUTION: The circular polarizer includes a polarization layer, an adhesive layer, and a first phase difference layer. The first phase difference layer is a liquid crystal layer. The circular polarizer has a square shape with a glue missing part in an end part in a plane direction or a square shape with a notch part in at least a side. The square shape has a pair of longer sides and a pair of shorter sides. The glue missing part is formed so that the position of the innermost edge in the end part of the adhesive layer is 3 μm to 50 μm inner from the position of the outermost edge in the end part of the polarization layer, in a cross section which passes through the region where the polarization layer and the adhesive layer overlap with each other in the laminate direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to an optical laminate.

The polarizing layer, the retardation layer, and the like are widely used as optical members constituting an organic EL display device or a liquid crystal display device using an organic light emitting diode (OLED). For example, Patent Document 1 describes that a composite polarizing plate in which a polarizing element and a retardation film coated with a liquid crystal compound are laminated is used for a liquid crystal display device.

In Patent Document 1, by eliminating the unevenness existing on the outer peripheral end surface (cut surface) when the composite polarizing plate is cut by chip cutting or the like, defects such as peeling and floating of the retardation film are suppressed even under moist heat conditions. It is stated that it can be done.

Japanese Unexamined Patent Publication No. 2008-9237

When a composite polarizing plate in which a polarizing layer and a retardation film are laminated is exposed to a high temperature environment, the hue of the reflected light at the end of the composite polarizing plate changes, and the uniformity of the hue of the reflected light in the plane deteriorates. Was found.

An object of the present invention is to provide an optical laminate capable of suppressing deterioration of hue uniformity of reflected light in a plane even in a high temperature environment.

The present invention provides the following optical laminates.
[1] An optical laminate having a polarizing layer, an adhesive layer, and a first retardation layer in this order.
The optical laminate has a glue chipped portion at an end portion in the plane direction thereof.
In the cross section of the adhesive chipped portion passing through the portion where the polarizing layer and the pressure-sensitive adhesive layer overlap in the stacking direction, the position of the innermost end at the end of the pressure-sensitive adhesive layer is the most at the end of the polarizing layer. An optical laminate formed so as to be located 3 μm or more inward from the position of the outer end.
[2] The optical laminate according to [1], wherein the polarizing layer is a polyvinyl alcohol-based resin film in which a dichroic dye is adsorbed and oriented.
[3] The optical laminate has a square shape or a square shape having a notch on at least one side.
The optical laminate according to [1] or [2], wherein the glue chipped portion is formed on at least one side of the square shape.
[4] The square shape has a pair of long sides and a pair of short sides.
The absorption axis direction of the polarizing layer forms an angle of 45 ° ± 10 ° with respect to the long side.
The optical laminate according to [3], wherein the glue chipped portion is formed on at least one of the pair of long sides and at least one of the pair of short sides.
[5] The square shape has a pair of long sides and a pair of short sides.
The absorption axis direction of the polarizing layer forms an angle of 0 ° ± 10 ° with respect to the long side.
The optical laminate according to [3], wherein the glue chipped portion is formed on at least one of the pair of short sides.
[6] The square shape has a pair of long sides and a pair of short sides.
The absorption axis direction of the polarizing layer forms an angle of 0 ° ± 10 ° with respect to the short side.
The optical laminate according to [3], wherein the glue chipped portion is formed on at least one of the pair of long sides.
[7] The optical laminate according to any one of [1] to [6], which has a protective layer on one side or both sides of the polarizing layer.
[8] The optical laminate according to any one of [1] to [7], further having a second retardation layer on the opposite side of the first retardation layer from the pressure-sensitive adhesive layer.
[9] The optical laminate according to [8], wherein the second retardation layer is provided on the first retardation layer via an adhesive layer.
[10] The optical laminate according to any one of [1] to [9], which is a circularly polarizing plate.

According to the present invention, it is possible to provide an optical laminate in which the uniformity of the hue of the reflected light in the plane is suppressed from being deteriorated even in a high temperature environment.

It is sectional drawing which shows typically an example of the optical laminated body of this invention. It is sectional drawing which shows the other example of the optical laminated body of this invention schematically. (A) and (b) are schematic views for explaining the method of making the pressure-sensitive adhesive layer in an Example.

Hereinafter, preferred embodiments of the optical laminate of the present invention will be described with reference to the drawings. The scope of the present invention is not limited to the embodiments described here, and various modifications can be made without impairing the gist of the present invention.

FIG. 1 is a cross-sectional view schematically showing an example of the optical laminate of the present embodiment. In the figure, W represents the plane direction. As shown in FIG. 1, the optical laminate 11 of the present embodiment has a polarizing plate 40, an adhesive layer 31, and a first retardation layer 21 in this order. The polarizing plate 40 of the optical laminate 11 shown in FIG. 1 has a first protective layer 42 (protective layer), a polarizing layer 41, and a second protective layer 43 (protective layer) in this order. The pressure-sensitive adhesive layer 31 is provided on the side of the first protective layer 42.

The polarizing layer 41 may be a polyvinyl alcohol-based resin film (hereinafter, may be referred to as “PVA-based resin film”) in which a bicolor dye such as iodine is adsorbed or oriented, and the PVA-based resin. The film is usually a stretched polyvinyl alcohol-based resin film. The polarizing layer 41 may be one in which the dichroic dye is oriented in the layer in which the liquid crystal compound is cured. The first protective layer 42 and the second protective layer 43 are layers for protecting the polarizing layer 41. The first retardation layer 21 may be a retardation film or a liquid crystal layer containing a liquid crystal compound. The liquid crystal layer may be, for example, a cured layer formed by polymerizing a polymerizable liquid crystal compound. When the first retardation layer 21 is a liquid crystal layer, the optical laminate 11 is for orienting the liquid crystal compound forming the first retardation layer 21 on the side opposite to the pressure-sensitive adhesive layer 31 of the first retardation layer 21. It may have an orientation layer of.

The optical laminate 11 has a glue chipped portion 5 at an end portion in the plane direction W thereof. As shown in FIG. 1, the adhesive chipped portion 5 is the most at the end portion of the pressure-sensitive adhesive layer 31 in the cross section through the portion where the polarizing layer 41 and the pressure-sensitive adhesive layer 31 overlap in the stacking direction orthogonal to the plane direction W. The position of the inner end is formed so as to be located inward by the length of the distance L1 from the position of the outermost end at the end of the polarizing layer 41. In the present specification, the position of the innermost end at the end of the pressure-sensitive adhesive layer 31 means the position of the end of the pressure-sensitive adhesive layer 31 that is the innermost in the plane direction W, and is the innermost position at the end of the polarizing layer 41. The position of the outer end means the position of the outermost end of the polarizing layer 41 in the plane direction W.

The distance L1 of the glue chipped portion 5 is 3 μm or more, preferably 5 μm or more, 6 μm or more, 7 μm or more, or 8 μm or more. The distance L1 is usually 120 μm or less, 100 μm or less, 75 μm or less, 50 μm or less, or 25 μm or less.

The polarizing plate 40 included in the optical laminate 11 has a polarizing layer 41. The polarizing layer 41 may shrink in a high temperature environment. Therefore, when the optical laminate 11 is exposed to a high temperature environment, the edge of the first retardation layer 21 laminated on the polarizing plate 40 via the pressure-sensitive adhesive layer 31 due to the shrinkage of the polarizing layer 41 (polarizing plate 40). It is considered that the contraction stress of the polarizing layer 41 is concentrated on the portion. When the above-mentioned contraction stress is concentrated on the end of the first retardation layer 21, the hue of the reflected light at the end of the optical laminate 11 and other than the end are due to the influence of the photoelasticity of the first retardation layer 21. It is presumed that the difference from the hue of the reflected light in this portion becomes large, and the uniformity of the hue of the reflected light in the plane of the optical laminate 11 deteriorates. In the present embodiment, as described above, the distance L1 in the adhesive chipped portion 5 of the optical laminate 11 is set to 3 μm or more. This makes it easier to disperse the shrinkage stress of the polarizing layer 41 when the optical laminate 11 is exposed to a high temperature environment, so that the shrinkage stress applied to the end portion of the first retardation layer 21 can be reduced. As a result, the difference between the hue of the reflected light at the end portion of the optical laminate 11 and the hue of the reflected light at the portion other than the end portion due to the influence of the photoelasticity of the first retardation layer 21 can be reduced. It is considered that deterioration of the uniformity of the hue of the reflected light in the plane of the optical laminate 11 can be suppressed.

Further, if the distance L1 of the adhesive chipped portion 5 in the optical laminate 11 is too large, the adhesive area between the polarizing plate 40 and the first retardation layer 21 becomes small, so that the end portion may be peeled off or air bubbles may be generated during the high temperature durability test. Such defects are likely to occur.

The effect of shrinkage of the polarizing layer 41 in a high temperature environment is that the dichroic dye on the PVA-based resin film is more affected than when the polarizing layer 41 has the dichroic dye oriented in the layer in which the liquid crystal compound is cured. Is likely to be noticeable when the polarizing layer is formed by adsorbing a dichroic dye on a PVA-based resin film by dyeing and then stretching the polarizing layer. Therefore, when a PVA-based resin film in which a dichroic dye is adsorbed or oriented is used as the polarizing layer 41, the distance L1 at the glue-missing portion 5 is set to 3 μm or more so that the optical laminate 11 is in-plane. It is possible to more preferably suppress the deterioration of the hue uniformity of the reflected light in the above.

The distance L1 of the glue chipped portion 5 is the position of the innermost end in the end portion of the pressure-sensitive adhesive layer 31 determined based on the profile of the cross section of the optical laminate 11 measured by measuring the profile of the cross section using a laser microscope. And, it can be calculated based on the position of the outermost end in the end portion of the polarizing layer 41. When the outer shape of the optical laminate 11 has a linear side and the glue chipped portion 5 is formed on the side, the cross section of the optical laminate 11 is formed with the glue chipped portion 5 on the side. It is a cross section when cut along a direction perpendicular to the side at the above position. Further, when the outer shape of the optical laminate 11 has a curved portion and the glue chipped portion 5 is formed in the curved portion, the cross section of the optical laminate 11 is the position where the glue chipped portion 5 is formed. It is a cross section when cut through the position P of the tangent line in the surface direction of the optical laminate 11 in P and along the direction perpendicular to the tangent line.

The shape of the adhesive chipped portion 5 in the optical laminate 11 is not particularly limited, and the end portion of the pressure-sensitive adhesive layer 31 may have a tapered shape as shown in FIG. 1, and the laminate is orthogonal to the plane direction W. It may be parallel to the direction, or may be formed in a sawtooth shape, an uneven shape, a curved shape, or the like. As shown in FIG. 1, in the adhesive layer 31 in the adhesive chipped portion 5, the position of the end portion of the surface on the polarizing plate 40 side is the position of the end portion of the surface of the adhesive layer 31 on the first retardation layer 21 side. The shape may be tapered in the plane direction, and conversely, the position of the end portion of the surface on the polarizing plate 40 side is the first retardation layer of the pressure-sensitive adhesive layer 31. It is outside the position of the end portion of the surface on the 21 side in the surface direction, and the shape may be a tapered shape. In the latter case of the tapered shape, the contraction stress of the polarizing layer 41 in a high temperature environment is easily dispersed, so that it is considered that it is easy to suppress deterioration of the hue uniformity of the reflected light in the plane of the optical laminate 11. ..

The outer shape of the optical laminate 11 may be square in the plane direction (plan view) or square with a notch on at least one side. In the present specification, the square shape means a rectangle shape or a square shape, and includes a square shape in which at least one of four corners of the square shape is rounded. The boundary between two sides that are continuous through the rounded corner portion is a position that bisects the contour length of the rounded corner portion. The contour length of the rounded corner portion is the length between the ends of the straight line portion of each of the two consecutive sides via the rounded corner portion located on the rounded corner portion side. Examples of the notch portion include a concave shape that is concave toward the opposite side, and the concave shape may be U-shaped or V-shaped. The notch may be formed on one side of a square shape or may be formed on two or more sides. The notch portion can be provided in, for example, a smartphone or the like in an area where at least one of an earpiece, a speaker, a camera lens, an LED lamp, a proximity sensor, an illuminance sensor, a fingerprint authentication sensor, an operation button, and the like is installed.

When the optical laminate 11 has a square shape, the glue chipping portion 5 is preferably formed on at least one side of the square shape, may be formed on two or more sides, or may be formed on all four sides. good. Further, the glue chipped portion 5 may be formed continuously or discontinuously over the entire length of the side, or may be formed in a part of the side. Further, the glue chipped portion 5 may be formed in at least a part of the notched portion, or may be formed in the entire notched portion.

The optical laminate 11 may have a hole that penetrates the entire optical laminate 11 in the stacking direction. The hole portion may have a circular shape, an elliptical shape, a polygonal shape such as a quadrangular shape or a hexagonal shape, and at least one of the corners of the polygonal shape may be rounded. A glue chipped portion 5 may be formed on the peripheral portion of the hole portion. The glue chipped portion formed in the hole portion may be formed in at least a part of the peripheral portion of the hole portion, or may be formed in the entire peripheral portion of the hole portion. The hole can be provided in an area where a camera lens or the like is installed, for example, in a smartphone or the like.

The optical laminate 11 has a rectangular shape, and this rectangular shape has a rectangular shape having a pair of long sides and a pair of short sides, and the absorption axis direction of the polarizing layer 41 is 45 ° ± 10 ° with respect to the long sides. When formed at an angle, the glue chipped portion 5 is preferably formed on at least one of a pair of long sides and at least one of a pair of short sides. In the present specification, the above-mentioned angle means an acute angle among the angles formed by the absorption axis direction and the long side. The glue chipped portion 5 may be formed on both of the pair of long sides, or may be formed on both of the pair of short sides. When the polarizing layer 41 of the optical laminate 11 is exposed to a high temperature environment, it tends to shrink in the absorption axis direction, so that the shrinkage stress of the polarizing layer 41 tends to concentrate on the sides located at both ends in the absorption axis direction. Therefore, in the optical laminate 11 in which the absorption axis direction and the long side are in a relationship of 45 ° ± 10 °, the contraction stress of the polarizing layer 41 is likely to be concentrated on both the long side and the short side, and the first retardation layer 21 It is considered that the hue of the reflected light of is easily changed. As described above, by providing the glue chipped portion 5 on at least one of the pair of long sides and at least one of the pair of short sides, the polarizing layer 41 of the polarizing layer 41 is exposed to the optical laminate 11 in a high temperature environment. The contraction stress can be dispersed in a portion where the contraction stress is likely to be concentrated. As a result, it is considered that the deterioration of the in-plane hue uniformity of the reflected light can be effectively suppressed even when the optical laminate 11 is exposed to a high temperature environment. The angle formed by the absorption axis direction of the polarizing layer 41 with respect to the long side may be 45 ° ± 5 °, 45 ° ± 2 °, or 45 °.

The optical laminate 11 has a rectangular shape, and this rectangular shape has a rectangular shape having a pair of long sides and a pair of short sides, and the absorption axis direction of the polarizing layer 41 is 0 ° ± 10 ° with respect to the long sides. When formed at an angle, the glue chipped portion 5 is preferably formed on at least one of a pair of short sides. In the present specification, the above-mentioned angle means an acute angle among the angles formed by the absorption axis direction and the long side. The glue chipped portion 5 may be formed on both of the pair of short sides. In the optical laminate 11 in which the absorption axis direction and the long side have a relationship of 0 ° ± 10 °, the contraction stress of the polarizing layer 41 tends to concentrate on the short side due to the above reason, and the reflection of the first retardation layer 21 It is thought that the hue of light is likely to change. Therefore, by providing the glue chipped portion 5 on at least one of the pair of short sides, it is effective that the uniformity of the hue of the reflected light in the plane deteriorates even when the optical laminate 11 is exposed to a high temperature environment. It is thought that it can be suppressed. The angle formed by the absorption axis direction of the polarizing layer 41 with respect to the long side may be 0 ° ± 5 °, 0 ° ± 2 °, or 0 °.

The optical laminate 11 has a rectangular shape, and this rectangular shape has a rectangular shape having a pair of long sides and a pair of short sides, and the absorption axis direction of the polarizing layer 41 is 0 ° ± 10 ° with respect to the short sides. When formed at an angle, the glue chipped portion 5 is preferably formed on at least one of a pair of long sides. In the present specification, the above-mentioned angle means an acute angle among the angles formed by the absorption axis direction and the short side. The glue chipped portion 5 may be formed on both of the pair of long sides. In the optical laminate 11 in which the absorption axis direction and the short side have a relationship of 0 ° ± 10 °, the contraction stress of the polarizing layer 41 tends to concentrate on the long side due to the above reason, and the reflection of the first retardation layer 21 It is thought that the hue of light is likely to change. Therefore, by providing the glue chipped portion 5 on at least one of the pair of long sides, it is effective that the uniformity of the hue of the reflected light in the plane deteriorates even when the optical laminate 11 is exposed to a high temperature environment. It is thought that it can be suppressed. The angle formed by the absorption axis direction of the polarizing layer 41 with respect to the short side may be 0 ° ± 5 °, 0 ° ± 2 °, or 0 °.

In the optical laminate 11 shown in FIG. 1, the first retardation layer 21 may be an A plate or a C plate. Further, in the optical laminate 11 shown in FIG. 1, a circular polarizing plate can be formed by using the first retardation layer 21 as a 1/4 wave plate.

In the optical laminate 11 shown in FIG. 1, for example, a polarizing plate 40 and a first retardation layer 21 are prepared, and among the polarizing plate 40 on the first protective layer 42 side and on the first retardation layer 21. It can be produced by applying or transferring a pressure-sensitive adhesive to at least one of them, and bonding the polarizing plate 40 and the first retardation layer 21 via the pressure-sensitive adhesive layer. When the first retardation layer 21 is a liquid crystal layer, it is combined with the first retardation layer 21 of the first retardation layer with a base material layer in which the first retardation layer 21 is detachably formed on the first base material layer. , The polarizing plate 40 may be laminated with an adhesive, and then the first base material layer may be peeled off.

The method for forming the adhesive chipped portion 5 in the optical laminate 11 is not particularly limited, but it can be formed, for example, by adjusting the coating range and the transfer position of the pressure-sensitive adhesive layer for forming the pressure-sensitive adhesive layer 31. .. When the pressure-sensitive adhesive layer 31 is formed by transfer, a portion to be a glue-chip portion 5 is formed in the pressure-sensitive adhesive layer formed on a release film or the like prepared for transfer, and the pressure-sensitive portion 5 is formed. The pressure-sensitive adhesive layer on which the portion is formed may be transferred onto the polarizing plate 40 or the first retardation layer 21.

In order to form a portion to be the adhesive chipped portion 5 in the pressure-sensitive adhesive layer formed on the release film or the like, for example, as shown in FIGS. 3A and 3B, the pressure-sensitive adhesive layer 61 is formed on the release film 62. The pressure-sensitive adhesive layer 60 with a release film is prepared, and the pressure-sensitive adhesive layer 60 with a release film can be formed by cutting the pressure-sensitive adhesive layer 60 with a release film from the pressure-sensitive adhesive layer 61 side with a single-edged cutting blade 65. In the process of cutting the pressure-sensitive adhesive layer 60 with the release film in this way, the pressure-sensitive adhesive layer 61 can be pushed into a tapered shape by the side of both sides of the single-edged cutting blade 65 on which the blade is formed. , The pressure-sensitive adhesive layer 31 having a tapered end can be formed.

(Modification example)
The optical film of the present embodiment may be modified as shown in the following modifications, and the structures and steps of the embodiments and the modifications thereof may be combined and implemented.

(Modification example 1)
In the above embodiment, the optical laminate 11 having the polarizing plate 40 having the first protective layer 42 and the second protective layer 43 on both sides of the polarizing layer 41 has been described, but the present invention is not limited thereto. The polarizing plate may include a polarizing layer 41 and one of the first protective layer 42 and the second protective layer 43. Further, the optical laminate 11 may not include the first protective layer 42 and the second protective layer 43.

(Modification 2)
When the optical laminate 11 shown in FIG. 1 is a circularly polarizing plate, this circularly polarizing plate can be used, for example, for antireflection of an organic electroluminescence (organic EL) display device. In this case, the optical laminate 11 is used by being bonded to the visible side of the optical display element of the organic EL display device. Therefore, the optical laminate 11 may have an adhesive layer for an optical display element for bonding to the optical display element on the side opposite to the pressure-sensitive adhesive layer 31 of the first retardation layer 21.

(Modification example 3)
In the above embodiment, the optical laminate 11 including the first retardation layer 21 has been described, but the present invention is not limited to this, and the optical laminate 11 shown in FIG. 2 may be used, for example. FIG. 2 is a cross-sectional view schematically showing another example of the optical laminate of the present embodiment. In the following, the same members as those described above will be designated by the same reference numerals, and the description thereof will be omitted. The optical laminate 12 shown in FIG. 2 has a polarizing plate 40, an adhesive layer 31, a first retardation layer 21, an adhesive layer 35, and a second retardation layer 22 in this order. The adhesive layer 35 may be an adhesive layer formed by using an adhesive, or may be an adhesive layer formed by using an adhesive. The second retardation layer 22 may be a retardation film or a liquid crystal layer containing a liquid crystal compound such as a polymerizable liquid crystal compound. When the second retardation layer 22 is a liquid crystal layer, the optical laminate 12 is oriented to orient the liquid crystal compound forming the second retardation layer 22 on the side opposite to the adhesive layer 35 of the second retardation layer 22. It may have a layer.

In the optical laminate 12, the first retardation layer 21 is a 1/2 wave plate and the second retardation layer 22 is a 1/4 wave plate; the first retardation layer 21 is a 1/4 of the inverse wavelength dispersibility. A wave plate, a second retardation layer 22 as a positive C plate; a first retardation layer 21 as a positive C plate, a second retardation layer 22 as a 1/4 wavelength plate with inverse wavelength dispersibility, and the like. , Can be a circular wave plate. When the combination of the first retardation layer 21 and the second retardation layer 22 is a 1/2 wavelength plate and a 1/4 wavelength plate, the phase of the 1/2 wavelength plate is delayed with respect to the absorption axis direction of the polarizing layer 41. The axial direction can be 70 ° to 80 °, and the slow axial direction of the 1/4 wave plate can be 10 ° to 20 °. Further, when the combination of the first retardation layer 21 and the second retardation layer 22 is a 1/4 wave plate having an inverse wavelength dispersion and a positive C plate, the combination is 1/4 with respect to the absorption axis direction of the polarizing layer 41. The slow axis direction of the wave plate can be 40 ° to 50 °. When the optical laminate 12 which is a circularly polarizing plate is used for antireflection of the organic EL display device, the optical laminate 12 shown in FIG. 2 is on the opposite side of the adhesive layer 35 of the second retardation layer 22. It may have an adhesive layer for an optical display element.

For the optical laminate 12 shown in FIG. 2, for example, a retardation layer laminate in which the first retardation layer 21 and the second retardation layer 22 are laminated via an adhesive layer 35, and a polarizing plate 40 are prepared. A pressure-sensitive adhesive is applied or transferred to at least one of the first protective layer 42 side of the polarizing plate 40 and the first retardation layer 21 side of the retardation layer laminate, and the polarizing plate 40 and the retardation layer laminate are laminated. And can be formed by laminating with a pressure-sensitive adhesive. When both the first retardation layer 21 and the second retardation layer 22 are liquid crystal layers, the optical laminate 12 can be obtained, for example, as follows. First, the first retardation layer 21 of the first retardation layer with a base material layer on which the first retardation layer 21 is formably peelable on the first base material layer and the first releasable layer 21 on the second base material layer can be peeled off. The second retardation layer 22 of the second retardation layer with the base material layer on which the two retardation layers 22 are formed is laminated via an adhesive layer to obtain a retardation layer laminate. Next, the first base material layer is peeled off from the retardation layer laminate, and the first retardation layer 21 side and the first protective layer 42 side of the polarizing plate 40 are laminated via an adhesive, and then the first By peeling off the two base material layers, the optical laminate 12 shown in FIG. 2 can be obtained.

Hereinafter, each item common to the above-described embodiments and modifications thereof will be described in detail.

(Polarizing layer)
The polarizing layer 41 may be a PVA-based resin film in which a dichroic dye such as iodine is adsorbed or oriented, or a dichroic dye is oriented in a layer in which a liquid crystal compound is cured. There may be.

The PVA-based resin film is a film formed by using a polyvinyl alcohol-based resin. The polyvinyl alcohol-based resin refers to a resin containing 50% by mass or more of a structural unit derived from vinyl alcohol. As the polyvinyl alcohol-based resin, a saponified polyvinyl acetate-based resin can be used. The degree of saponification of the polyvinyl acetate-based resin can be determined in accordance with JIS K 6727 (1994), and can be, for example, in the range of 80.0 to 100.0 mol%.

Examples of the polyvinyl acetate-based resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and a copolymer of vinyl acetate and another monomer copolymerizable therewith. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth) acrylamides having an ammonium group. As used herein, the term "(meth) acrylic" refers to at least one selected from the group consisting of acrylics and methacryl. The same applies to other terms with "(meta)".

An example of the PVA-based resin film may be an unstretched film formed by forming a polyvinyl alcohol-based resin, or may be a stretched film obtained by stretching the unstretched film. When the PVA-based resin film is a stretched film, it is preferably a stretched film that is vertically uniaxially stretched, and preferably a stretched film that is dry-stretched. When the PVA-based resin film is a stretched film, the stretch ratio is usually 1.1 to 8 times.

Examples of the dichroic dye that is adsorbed and oriented on the PVA-based resin film include iodine and organic dyes. Examples of organic dyes include red BR, red LR, red R, pink LB, rubin BL, Bordeaux GS, sky blue LG, lemon yellow, blue BR, blue 2R, navy RY, green LG, violet LB, and violet B. Black H, Black B, Black GSP, Yellow 3G, Yellow R, Orange LR, Orange 3R, Scarlet GL, Scarlet KGL, Congo Red, Brilliant Violet BK, Supra Blue G, Supra Blue GL, Supra Orange GL, Direct Sky Blue, Direct first orange S, first black and the like can be mentioned. As the dichroic dye, only one kind may be used alone, or two or more kinds may be used in combination.

Examples of the polarizing layer in which the dichroic dye is oriented in the layer on which the liquid crystal compound is cured include a cured layer in which the dichroic dye is oriented in the polymerizable liquid crystal compound and the polymerizable liquid crystal compound is polymerized. Can be mentioned. Such a polarizing layer is formed by applying a polarizing layer forming composition containing a liquid crystal compound and a dichroic dye on a base film, and polymerizing and curing the liquid crystal compound while maintaining the liquid crystal state. Can be done. The polarizing layer thus obtained is in a state of being laminated on the base film, and the base film may be used as it is as a protective layer of the polarizing layer. Alternatively, the polarizing layer with a base film capable of peeling the base film from the polarizing layer may be laminated on the first retardation layer via the pressure-sensitive adhesive layer 31, and then the base film may be peeled off.

The liquid crystal compound may have a property of exhibiting a liquid crystal state, and it is particularly preferable that the liquid crystal compound has a higher-order orientation state such as a smectic phase because high polarization performance can be exhibited. It is also preferable that the liquid crystal compound has a polymerizable functional group. The dichroic dye is a dye that is oriented together with the liquid crystal compound to exhibit dichroism, and the dichroic dye itself may have liquid crystal properties or may have a polymerizable functional group. can. Any compound in the composition for forming a polarizing layer containing a liquid crystal compound has a polymerizable functional group.

Examples of the dichroic dye that can be used for the polarizing layer using the liquid crystal compound include an acridine dye, an oxazine dye, a cyanine dye, a naphthalene dye, an azo dye, an anthraquinone dye, and the like, and among them, the azo dye is preferable. Examples of the azo dye include a monoazo dye, a bisazo dye, a trisazo dye, a tetrakisazo dye, a stilbene azo dye, and the like, and a bisazo dye and a trisazo dye are more preferable. As the dichroic dye, only one kind may be used alone, or two or more kinds may be used in combination.

The composition for forming a polarizing layer includes a solvent, a polymerization initiator such as a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a dispersant, a leveling agent, a stabilizer, a surfactant, a cross-linking agent, a silane coupling agent, etc. Can be included. As the polymerizable liquid crystal compound, the dichroic dye, the solvent, the polymerization initiator, the photosensitizer, the polymerization inhibitor and the like contained in the composition for forming the polarizing layer, known ones can be used. Further, as the polymerizable liquid crystal compound, the same compounds as those exemplified as the polymerizable liquid crystal compound used for obtaining the first retardation layer and the second retardation layer described later may be used.

The thickness of the polarizing layer 41 is usually 2 to 40 μm, and is preferably 30 μm or less, more preferably 20 μm or less, from the viewpoint of thinning the polarizing layer. The polarizing layer in which the dichroic dye is oriented in the layer in which the liquid crystal compound is cured should be formed to have a smaller thickness than the polarizing layer in which the dichroic dye such as iodine is adsorbed and oriented on the PVA-based resin film. Can be done. The thickness of the polarizing layer using the liquid crystal compound may be, for example, 0.5 to 5 μm, preferably 1 to 4 μm.

Further, the visible sensitivity-corrected simple substance transmittance Ty of the polarizing layer 41 is preferably 40 to 47%, more preferably 41 to 45%, in consideration of the balance with the visual sensitivity-corrected polarization degree Py. The luminous efficiency correction degree of polarization Py is preferably 99.9% or more, and more preferably 99.95% or more. Ty and Py can be obtained by correcting the luminosity factor of the obtained transmittance and polarization degree with a JIS Z 8701 2 degree field (C light source) using an absorptiometer with an integrating sphere.

(Polarizer)
The polarizing plate is obtained by laminating a protective layer (first protective layer, second protective layer) on one or both sides of a polarizing layer via a known pressure-sensitive adhesive layer or adhesive layer. The thickness of the polarizing plate can be, for example, 2 μm or more and 300 μm or less, 10 μm or more, 150 μm or less, 120 μm or less, or 80 μm or less. ..

As the protective layer, for example, a film formed of a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture blocking property, isotropic property, stretchability and the like is used. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyether sulfone resins; polysulfone resins; polycarbonate resins; polyamides such as nylon and aromatic polyamides. Resin; Polygon resin; Polyethylene resin such as polyethylene, polypropylene, ethylene / propylene copolymer; Cyclic polyolefin resin having cyclo-based and norbornene structure (also referred to as norbornene-based resin); (meth) acrylic resin; polyallylate resin; polystyrene resin Polyvinyl alcohol resins, as well as mixtures thereof, can be mentioned. When the protective layers are laminated on both sides of the polarizing layer, the resin compositions of the two protective layers may be the same or different. The film formed from the thermoplastic resin may be surface-treated (for example, corona treatment) in order to improve the adhesion to the polarizing layer, and may be subjected to a thin layer such as a primer layer (also referred to as an undercoat layer). May be formed.

The protective layer may be, for example, a stretched version of the above-mentioned thermoplastic resin or a non-stretched layer (hereinafter, may be referred to as “unstretched resin”). Examples of the stretching treatment include uniaxial stretching and biaxial stretching.

The thickness of the protective layer is preferably 3 μm or more, and more preferably 5 μm or more. The thickness of the protective layer is preferably 50 μm or less, more preferably 35 μm or less. The above-mentioned upper limit value and lower limit value can be arbitrarily combined. The thinner the polarizing plate, the smaller the rigidity, and the more easily it is affected by the shrinkage stress of the polarizing layer. Therefore, an optical laminate having a protective layer in which the polarizing plate has a small thickness is easily affected by the contraction stress of the polarizing layer at the end thereof, and the uniformity of the hue of the reflected light in the plane is likely to deteriorate in a high temperature environment. It tends to be. Therefore, in such an optical laminate, as described above, by setting the distance L1 of the amount of adhesive chipping to 3 μm or more, it is effective that the uniformity of the hue of the reflected light in the plane is deteriorated even in a high temperature environment. It is thought that it can be suppressed.

The surface of the protective layer opposite to the polarizing layer may have a surface treatment layer, and may have, for example, a hard coat layer, an antireflection layer, an antistick layer, an antiglare layer, a diffusion layer, and the like. .. The surface treatment layer may be another layer laminated on the protective layer, or may be formed by applying a surface treatment to the surface of the protective layer.

(1st retardation layer and 2nd retardation layer)
The first retardation layer and the second retardation layer (hereinafter, both may be collectively referred to as a "phase difference layer") may be a retardation film or a liquid crystal layer. The retardation film may be any film exhibiting optical anisotropy, for example, polyvinyl alcohol, polycarbonate, polyester, polyarylate, polyimide, polyolefin, polycycloolefin, polystyrene, polysulfone, polyether sulfone, polyvinylidene fluoride. / Examples thereof include a stretched film obtained by stretching a film formed of polymethylmethacrylate, acetylcellulose, ethylene-vinyl acetate copolymer saponified product, polyvinyl chloride, etc. about 1.01 to 6 times.

When the retardation layer is a liquid crystal layer, the type of the liquid crystal compound forming the liquid crystal layer is not particularly limited, and a rod-shaped liquid crystal compound, a disk-shaped liquid crystal compound, and a mixture thereof can be used. The liquid crystal layer is formed by applying a liquid crystal layer forming composition containing a liquid crystal compound, a solvent, and various additives as necessary on the alignment layer to form a coating film, and solidifying (curing) the coating film. , A liquid crystal layer which is a cured layer of a liquid crystal compound can be formed. Alternatively, the liquid crystal layer forming composition may be applied onto the base material layer to form a coating film, and the coating film may be stretched together with the base material layer to form the liquid crystal layer. The composition for forming a liquid crystal layer may contain a polymerization initiator, a reactive additive, a leveling agent, a polymerization inhibitor and the like in addition to the above-mentioned liquid crystal compound and solvent. Known liquid crystal compounds, solvents, polymerization initiators, reactive additives, leveling agents, polymerization inhibitors and the like can be appropriately used.

The base material layer (first base material layer, second base material layer) on which the liquid crystal layer is formed is preferably a film formed of a resin material. As the resin material, for example, a resin material having excellent transparency, mechanical strength, thermal stability, stretchability and the like is used. Specifically, polyolefin resins such as polyethylene and polypropylene; cyclic polyolefin resins such as norbornene polymers; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; (meth) acrylic acid, poly (meth) methyl acrylate and the like. (Meta) acrylic acid resin; cellulose ester resin such as triacetyl cellulose, diacetyl cellulose and cellulose acetate propionate; vinyl alcohol resin such as polyvinyl alcohol and polyvinyl acetate; polycarbonate resin; polystyrene resin; poly Arilate-based resin; polysulfone-based resin; polyethersulfone-based resin; polyamide-based resin; polyimide-based resin; polyetherketone-based resin; polyphenylene sulfide-based resin; polyphenylene oxide-based resin, and mixtures and copolymers thereof. Can be done. Among these resins, it is preferable to use any one of cyclic polyolefin-based resin, polyester-based resin, cellulose ester-based resin and (meth) acrylic acid-based resin, or a mixture thereof.

The base material layer may be a single layer or may have a multi-layer structure of two or more layers. When having a multi-layer structure, the types of resins forming each layer may be the same or different from each other. The thickness of the base material layer is not particularly limited, but is generally preferably 1 to 300 μm, more preferably 10 to 200 μm, and preferably 30 to 120 μm from the viewpoint of workability such as strength and handleability. More preferred.

The above-mentioned alignment layer has an orientation-regulating force for aligning a liquid crystal compound such as a polymerizable liquid crystal compound contained in the liquid crystal layer formed on the liquid crystal layer in a desired direction. Examples of the oriented layer include an oriented polymer layer formed of an oriented polymer, a photo-oriented polymer layer formed of a photo-aligned polymer, and a grub-oriented layer having an uneven pattern or a plurality of grubs (grooves) on the layer surface. Can be done. The thickness of the alignment layer is usually 10 to 500 nm, preferably 10 to 200 nm.

(Adhesive layer)
The pressure-sensitive adhesive layer is a layer formed by using a pressure-sensitive adhesive. In the present specification, the pressure-sensitive adhesive is a so-called pressure-sensitive adhesive, which exhibits adhesiveness by sticking itself to an adherend such as an optical film or a liquid crystal layer. As the pressure-sensitive adhesive, a conventionally known pressure-sensitive adhesive having excellent optical transparency can be used without particular limitation. For example, a pressure-sensitive adhesive having a base polymer such as acrylic, urethane, silicone, or polyvinyl ether is used. be able to. The thickness of the pressure-sensitive adhesive layer may be 3 μm or more, 5 μm or more, 35 μm or less, or 30 μm or less.

The pressure-sensitive adhesive layer contains additives such as an antistatic agent using an ultraviolet absorber, an ionic compound, a solvent, a cross-linking catalyst, a tackifier resin (tack fire), a plasticizer, a softening agent, a dye, a pigment, and an inorganic filler. It may be included. In particular, when the pressure-sensitive adhesive layer contains an ultraviolet absorber, when the first retardation layer is a liquid crystal layer, the liquid crystal compound contained in the liquid crystal layer is suppressed from being deteriorated by the influence of external light or the like. be able to.

(Adhesive layer)
The adhesive layer can be formed by an adhesive layer, an adhesive layer formed by using an adhesive, and a combination thereof, and is usually one layer, but may be two or more layers. When the adhesive layer is composed of two or more layers, each layer may be formed of the same material or different materials. The pressure-sensitive adhesive layer can be formed by using the above-mentioned pressure-sensitive adhesive.

As the adhesive that can be used for the adhesive layer, for example, conventionally known adhesives such as water-based adhesives and active energy ray-curable adhesives can be used without particular limitation. Examples of the water-based adhesive include a polyvinyl alcohol-based resin aqueous solution, a water-based two-component urethane-based emulsion adhesive, and the like. The active energy ray-curable adhesive is an adhesive that cures by irradiating with active energy rays such as ultraviolet rays, and includes, for example, a polymerizable compound and a photopolymerizable initiator, a photoreactive resin, and the like. Examples thereof include those containing a binder resin and a photoreactive cross-linking agent. Examples of the polymerizable compound include photopolymerizable monomers such as a photocurable epoxy monomer, a photocurable acrylic monomer, and a photocurable urethane monomer, and oligomers derived from these monomers. Examples of the photopolymerization initiator include substances that generate active species such as neutral radicals, anion radicals, and cationic radicals by irradiating them with active energy rays such as ultraviolet rays.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" and "part" in Examples and Comparative Examples are mass% and parts by mass.

[Preparation of polarizing plate]
As the first protective layer, a triacetyl cellulose film having a thickness of 20 μm was prepared. As the second protective layer, a norbornene-based resin film having a thickness of 29 μm in which a hard coat layer was formed on one surface was prepared. As the polarizing layer, a PVA-based resin film in which iodine, which is a dichroic dye, was adsorbed and oriented was prepared. The thickness of the polarizing layer was 8 μm.

Further, 3 parts by weight of carboxyl group-modified polyvinyl alcohol [trade name "KL-318" obtained from Kuraray Co., Ltd.] is dissolved in 100 parts by weight of water, and a polyamide epoxy-based additive which is a water-soluble epoxy resin is dissolved in the aqueous solution. An aqueous adhesive was prepared by adding 1.5 parts by weight of [trade name "Smilase Resin (registered trademark) 650 (30)" obtained from Taoka Chemical Industry Co., Ltd., an aqueous solution having a solid content concentration of 30% by weight]. ..

The first protective layer was saponified, and the surface of the second protective layer on the norbornene-based resin film side and both sides of the polarizing layer were corona-treated. The first protective layer is attached to one surface of the polarizing layer via the water-based adhesive obtained above, and the second protective layer is attached to the other surface of the polarizing layer via the same water-based adhesive as described above. The side opposite to the hard coat layer (norbornen-based resin film side) was bonded and dried to prepare a polarizing plate. The obtained polarizing plate was cut into a rectangular shape so that the absorption axis of the polarizing layer was 45 ° with respect to the long side direction.

・溶媒（９５部）：シクロペンタノン [Preparation of first retardation layer]
(Preparation of composition for forming a horizontally oriented layer)
The following components were mixed, and the obtained mixture was stirred at a temperature of 80 ° C. for 1 hour to obtain a composition for forming a horizontally oriented layer.
-Photo-alignable material (5 parts) (weight average molecular weight: 30,000):

-Solvent (95 parts): Cyclopentanone

・重合性液晶化合物Ｂ（１０部）：

・重合開始剤（６部）：
２−ジメチルアミノ−２−ベンジル−１−（４−モルホリノフェニル）ブタン−１−オン（イルガキュア３６９、ＢＡＳＦジャパン株式会社製） (Preparation of composition for forming a horizontally oriented liquid crystal layer)
The composition for forming a horizontally oriented liquid crystal layer is obtained by mixing the following components, further adding N-methyl-2-pyrrolidone (NMP) so that the solid content concentration becomes 13%, and stirring at 80 ° C. for 1 hour. I got something. The following polymerizable liquid crystal compound A was synthesized by the method described in JP-A-2010-31223, and the following polymerizable liquid crystal compound B was synthesized according to the method described in JP-A-2009-173893.
-Polymerizable liquid crystal compound A (90 parts):

-Polymerizable liquid crystal compound B (10 parts):

-Polymerization initiator (6 parts):
2-Dimethylamino-2-benzyl-1- (4-morpholinophenyl) butane-1-one (Irgacure 369, manufactured by BASF Japan Ltd.)

(Preparation of the first retardation layer)
A cyclic olefin resin (COP) film (ZF-14-50, manufactured by Nippon Zeon Corporation) was subjected to corona treatment. The composition for forming a horizontally oriented layer obtained above was applied to the corona-treated surface of this COP film with a bar coater, and dried at 80 ° C. for 1 minute. For this coating film, a polarized UV irradiation device (“SPOT CURE SP-9”, manufactured by Ushio Electric Co., Ltd.) was used to set the axial angle to 45 ° so that the ^{integrated light intensity at a wavelength of 313 nm was 100 mJ / cm 2.} The polarized UV was exposed to obtain a horizontally oriented layer.

Subsequently, the composition for forming a horizontally oriented liquid crystal layer obtained above was applied to the horizontally oriented layer using a bar coater, and dried at 120 ° C. for 1 minute. Irradiate the coating film with ultraviolet rays (in a nitrogen atmosphere, integrated light intensity at a wavelength of 365 nm: 500 mJ / cm ² ) using a high-pressure mercury lamp (“Unicure VB-15201BY-A”, manufactured by Ushio, Inc.). The first retardation layer, which is a horizontally oriented liquid crystal layer, was formed. The first retardation layer was a quarter wave plate exhibiting anti-wavelength dispersibility.

[Preparation of second retardation layer]
(Preparation of composition for forming vertically oriented layer)
Sunever SE610 (manufactured by Nissan Chemical Industries, Ltd.) was prepared as a composition for forming a vertically oriented layer.

(Preparation of composition for forming vertically oriented liquid crystal layer)
The following components were mixed, and cyclopentanone was further added so that the solid content concentration became 13% to obtain a composition for forming a vertically oriented liquid crystal layer.
Polymerizable liquid crystal compound C (100 parts):
Pariocolor® LC242 (manufactured by BASF)
・ Leveling agent (0.1 part):
F-556 (manufactured by DIC Corporation)
-Polymerization initiator (3 parts):
Irgacure 369 (manufactured by Ciba Specialty Chemicals)

(Preparation of second retardation layer)
A cyclic olefin resin (COP) film (ZF-14-50, manufactured by Nippon Zeon Corporation) was subjected to corona treatment. The composition for forming a vertically oriented layer obtained above was applied to the corona-treated surface of this COP film with a bar coater, and dried at 80 ° C. for 1 minute to obtain a vertically oriented layer. Subsequently, the composition for forming a vertically oriented liquid crystal layer obtained above was applied to the vertically oriented layer using a bar coater, and dried at 90 ° C. for 120 seconds. This coating film is irradiated with ultraviolet rays (in a nitrogen atmosphere, integrated light intensity at a wavelength of 365 nm: 500 mJ / cm ² ) using a high-pressure mercury lamp (“Unicure VB-15201BY-A”, manufactured by Ushio, Inc.). As a result, a second retardation layer, which is a vertically oriented liquid crystal layer, was formed. The second retardation layer was a positive C plate satisfying the relationship of nx≈ny <nz.

[Manufacturing of retardation layer laminate]
The surface of the first retardation layer prepared above opposite to the COP film and the surface of the second retardation layer prepared above opposite to the COP film were subjected to corona treatment. The corona-treated surfaces (the surface of the first phase difference layer and the surface of the second phase layer) are bonded to each other via an ultraviolet curable adhesive, and then irradiated with ultraviolet rays to cure the ultraviolet curable adhesive. , A retardation layer laminate in which the first retardation layer and the second retardation layer were laminated via an adhesive layer was obtained. The obtained retardation layer laminate was cut into a rectangular shape so that the slow axis of the first retardation layer (1/4 wave plate) was parallel to the long side direction.

[Measurement of the distance L1 of the glue chipped part]
An acrylic pressure-sensitive adhesive layer having a thickness of 20 μm provided on a release film was laminated on the second retardation layer side of the optical laminates obtained in each Example and each comparative example to obtain an optical laminate with a pressure-sensitive adhesive layer. .. With respect to this optical laminate with an adhesive layer, the side where the glue chipped portion is formed is confirmed, and at the position where the glue chipped portion is formed, the optical with the adhesive layer is formed along the direction perpendicular to the side. The profile of the cross section when the laminate was cut was measured using a laser microscope. Based on the measured profile, the distance L1 between the position of the innermost end at the end of the pressure-sensitive adhesive layer 61 and the position of the outermost end at the end of the polarizing layer was measured.

[High temperature test]
An acrylic pressure-sensitive adhesive layer having a thickness of 20 μm is laminated on the second retardation layer side of the optical laminates obtained in each Example and each comparative example, and the acrylic pressure-sensitive adhesive layer is bonded to a glass plate for evaluation. It was used as a sample. The obtained evaluation sample was placed in an oven at a temperature of 80 ° C. for 200 hours for a high temperature test. The evaluation sample after the high temperature test is placed on a reflecting plate (MIRO5 5011GP manufactured by Alanod) so that the glass plate is on the lower side, and the reflected light is measured using a spectrocolorimeter (CM2600d, Konica Minolta Co., Ltd.). The hue was measured. The measurement is performed by wearing a mask having an opening diameter φ of 1.5 mm when light enters the integrating sphere from the evaluation sample, and the hue (a) of the reflected light in the central portion at the four ends of the evaluation sample. ^* b ^*) and was calculated an average value of the difference between the hue of the reflected light ^(a * ^{b *)} of the central portion of the evaluation sample (a diagonal line of intersection of the rectangle) as Δa ^* b ^*.
Δa ^* b ^* = (Δa ^{* 2} + Δb ^{* 2} ) ^1/2

Further, after the evaluation sample after the high temperature test is placed on a reflector (MIRO5 5011GP manufactured by Alanod), the reflected light is visually observed from the optical laminate side to confirm the state of color unevenness of the optical laminate. Visibility was evaluated. When the state of color unevenness was weakly visually recognized, it was evaluated as A, and when it was strongly visually recognized, it was evaluated as B.

[Example 1]
3 (a) and 3 (b) are schematic views for explaining the method of producing the pressure-sensitive adhesive layer in the examples. As shown in FIG. 3A, a pressure-sensitive adhesive layer 60 with a release film having a pressure-sensitive adhesive layer 61 formed on the release film 62 using an acrylic pressure-sensitive adhesive having a thickness of 20 μm was prepared. The pressure-sensitive adhesive layer 61 contained an ultraviolet absorber. As shown in FIG. 3A, cutting of the tip portion 65a at an angle θ from the pressure-sensitive adhesive layer 61 side along a direction parallel to the stacking direction (arrow direction in the drawing) of the pressure-sensitive adhesive layer 60 with a release film. The blade 65 was cut into the adhesive layer 60 with the release film to cut it into a rectangular shape. A single-edged cutting blade 65 was used. The cut surface of the rectangular adhesive layer 60 with the release film after cutting was the surface of the single-edged cutting blade 65 that was in contact with the surface on which the blade was formed.

The adhesive layer 61 of the obtained rectangular adhesive layer 60 with a release film is bonded to the first protective layer side (triacetyl cell roll film side) of the polarizing plate produced above, and then the release film 62 is attached. It peeled off. After peeling and exposing the surface of the COP film on the first retardation layer side of the retardation layer laminate produced above and the surface of the pressure-sensitive adhesive layer 61 exposed by peeling off the release film 62, The COP film on the second retardation layer side is peeled off, and the layer structure of the second protective layer / polarizing layer / first protective layer / adhesive layer 61 / first retardation layer / adhesive layer / second retardation layer An optical laminate (circularly polarized light) having the above was obtained. In the production of the optical laminate, when the layers are bonded, the bonded surface is subjected to corona treatment, and when the layers are bonded, the long side and the short side of each layer are matched to absorb the polarizing layer. The axial direction was set to 45 ° with respect to the slow axial direction of the first retardation layer.

In the obtained optical laminate, a glue chipped portion was formed on the entire circumference thereof. The distance L1 was measured by the above procedure for the adhesive chipped portion at an arbitrary position on each side of the optical laminate, and the average value thereof was calculated. In addition, the obtained optical laminate was subjected to a high-temperature test, the change in the hue of the reflected light was measured, and the visibility for confirming the state of color unevenness was evaluated. These results are shown in Table 1. From the measurement results of the distance L1 on each side, it was recognized that the distance L1 of the glue-missing portion was about the same as the value shown in Table 1 on the entire circumference of the optical laminate of this example.

[Example 2 and Comparative Example 1]
As a cutting blade used for cutting the pressure-sensitive adhesive layer 60 with a release film (FIG. 3A), a rectangular cutting blade (single blade) having an angle θ of the tip portion 65a smaller than that used in Example 1 is used. An optical laminate was obtained in the same manner as in Example 1 except that the pressure-sensitive adhesive layer 60 with a release film having a shape was obtained. In the obtained optical laminate, a glue chipped portion was formed on the entire circumference thereof. The distance L1 was measured by the above procedure for the adhesive chipped portion at an arbitrary position on each side of the optical laminate, and the average value thereof was calculated. In addition, the obtained optical laminate was subjected to a high-temperature test, the change in the hue of the reflected light was measured, and the visibility for confirming the state of color unevenness was evaluated. These results are shown in Table 1. From the measurement results of the distance L1 on each side, it was recognized that the distance L1 of the glue-missing portion was about the same as the value shown in Table 1 on the entire circumference of the optical laminate of this example.

5 Glue chipped part, 11 Optical laminate, 12 Optical laminate, 21 First retardation layer, 22 Second retardation layer, 31 Adhesive layer, 35 Adhesive layer, 40 Polarizing plate, 41 Polarizing layer, 42 First protection Layer, 43 Second protective layer, 60 Adhesive layer with release film, 61 Adhesive layer, 62 Release film, 65 Cutting blade, 65a Cutting edge portion.

Claims (7)

A circularly polarizing plate having a polarizing layer, an adhesive layer, and a first retardation layer in this order.
The first retardation layer is a liquid crystal layer and
The circularly polarizing plate has a square shape having a glue chipped portion at an end portion in the plane direction thereof and a square shape or a square shape having a notch portion at least on one side.
The square has a pair of long sides and a pair of short sides.
The absorption axis direction of the polarizing layer forms an angle of 45 ° ± 10 ° with respect to the long side.
The glue chipped portion is
It is formed on at least one of the pair of long sides and at least one of the pair of short sides, and
In the cross section passing through the portion where the polarizing layer and the pressure-sensitive adhesive layer overlap in the stacking direction, the position of the innermost end at the end of the pressure-sensitive adhesive layer is 3 μm from the position of the outermost end at the end of the polarizing layer. A circularly polarizing plate formed so as to be located inside at least 50 μm. A circularly polarizing plate having a polarizing layer, an adhesive layer, and a first retardation layer in this order.
The first retardation layer is a liquid crystal layer and
The circularly polarizing plate has a square shape having a glue chipped portion at an end portion in the plane direction thereof and a square shape or a square shape having a notch portion at least on one side.
The square has a pair of long sides and a pair of short sides.
The absorption axis direction of the polarizing layer forms an angle of 0 ° ± 10 ° with respect to the long side.
The glue chipped portion is
It is formed on at least one of the pair of short sides and
In the cross section passing through the portion where the polarizing layer and the pressure-sensitive adhesive layer overlap in the stacking direction, the position of the innermost end at the end of the pressure-sensitive adhesive layer is 3 μm from the position of the outermost end at the end of the polarizing layer. A circularly polarizing plate formed so as to be located inside at least 50 μm. A circularly polarizing plate having a polarizing layer, an adhesive layer, and a first retardation layer in this order.
The first retardation layer is a liquid crystal layer and
The circularly polarizing plate has a square shape having a glue chipped portion at an end portion in the plane direction thereof and a square shape or a square shape having a notch portion at least on one side.
The square has a pair of long sides and a pair of short sides.
The absorption axis direction of the polarizing layer forms an angle of 0 ° ± 10 ° with respect to the short side.
The glue chipped portion is
It is formed on at least one of the pair of long sides and
In the cross section passing through the portion where the polarizing layer and the pressure-sensitive adhesive layer overlap in the stacking direction, the position of the innermost end at the end of the pressure-sensitive adhesive layer is 3 μm from the position of the outermost end at the end of the polarizing layer. A circularly polarizing plate formed so as to be located inside at least 50 μm. The circularly polarizing plate according to any one of claims 1 to 3, wherein the polarizing layer is a polyvinyl alcohol-based resin film in which a dichroic dye is adsorbed and oriented. The circular polarizing plate according to any one of claims 1 to 4, which has a protective layer on one side or both sides of the polarizing layer. The circularly polarizing plate according to any one of claims 1 to 5, further comprising a second retardation layer on the opposite side of the first retardation layer from the pressure-sensitive adhesive layer. The circularly polarizing plate according to claim 6, wherein the second retardation layer is provided on the first retardation layer via an adhesive layer.

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