KR20210145758A - optical laminate - Google Patents

Abstract

An object of the present invention is to provide an optical laminate capable of suppressing deterioration in the color uniformity of in-plane reflected light even under a high-temperature environment.
An optical laminated body has a polarizing layer, an adhesive layer, and a 1st retardation layer in this order. The optical laminate has a glue-free portion at an end portion in the plane direction, and the glue-free portion is the innermost end position at the end portion of the pressure-sensitive adhesive layer in the cross section passing the portion where the polarizing layer and the pressure-sensitive adhesive layer overlap in the lamination direction. is formed so as to be located 3 µm or more inside from the position of the outermost end at the end of the polarizing layer.

Description

optical laminate

The present invention relates to an optical laminate.

BACKGROUND ART A polarizing layer, a retardation layer, or the like is widely used as an optical member 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 using a composite polarizing plate in which a polarizer and a retardation film coated with a liquid crystal compound are laminated for a liquid crystal display device.

Patent Document 1 describes that the problem such as peeling or floating of the retardation film can be suppressed even under moist heat conditions by eliminating the unevenness present on the outer peripheral end surface (cut surface) when the composite polarizing plate is cut by chip cutting or the like. has been

Patent Document 1: Japanese Patent Laid-Open No. 2008-9237

It has been found that when a composite polarizing plate in which a polarizing layer and a retardation film are laminated is exposed to a high temperature environment, the color of the reflected light at the end of the composite polarizing plate changes, and the uniformity of the color of the in-plane reflected light is deteriorated.

An object of this invention is to provide the optical laminated body which can suppress that the uniformity of the hue of in-plane reflected light deteriorates also in a high-temperature environment.

This invention provides the following optical laminated bodies.

[1] An optical laminate having a polarizing layer, a pressure-sensitive adhesive layer, and a first retardation layer in this order, wherein the optical laminate has a glue-free portion at an end thereof in the plane direction;

In the section through which the polarizing layer and the pressure-sensitive adhesive layer overlap in the lamination direction, the position of the innermost end at the end of the pressure-sensitive adhesive layer is the position of the outermost end at the end of the polarizing layer. An optical laminate formed to be located 3 μm or more inside from the

[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 is a quadrangle or a quadrangle having a cutout on at least one side,

The optical laminate according to [1] or [2], wherein the glue-deficient portion is formed on at least one side of the quadrangle.

[4] The quadrangle 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-deficient 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 quadrangle 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-deficient portion is formed on at least one of the pair of short sides.

[6] The quadrangle 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-deficient 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], wherein the polarizing layer has a protective layer on one side or both sides thereof.

[8] The optical laminate according to any one of [1] to [7], further comprising a second retardation layer on a side opposite to the pressure-sensitive adhesive layer of the first retardation layer.

[9] The optical laminate according to [8], wherein the second retardation layer is formed 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.

ADVANTAGE OF THE INVENTION According to this invention, the optical laminated body which suppressed deterioration of the uniformity of the hue of in-plane reflected light even under a high-temperature environment can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows typically an example of the optical laminated body of this invention.
It is sectional drawing which shows typically the other example of the optical laminated body of this invention.
Fig.3 (a) and (b) is a schematic diagram for demonstrating the manufacturing method of the adhesive layer in an Example.

EMBODIMENT OF THE INVENTION Hereinafter, with reference to drawings, preferable embodiment of the optical laminated body of this invention is described. In addition, the scope of the present invention is not limited to the embodiment described herein, and various modifications can be made within a range that does not impair the spirit of the present invention.

1 : is sectional drawing which shows typically an example of the optical laminated body of this embodiment. In the figure, W represents the plane direction. As shown in FIG. 1, the optical laminated body 11 of this embodiment has the polarizing plate 40, the adhesive layer 31, and the 1st retardation layer 21 in this order. The polarizing plate 40 of the optical laminate 11 shown in FIG. 1 consists of the 1st protective layer 42 (protective layer), the polarizing layer 41, and the 2nd protective layer 43 (protective layer) in this order. In the optical laminate 11 , the pressure-sensitive adhesive layer 31 is formed on the first protective layer 42 side.

The polarizing layer 41 may be a polyvinyl alcohol-based resin film (hereinafter sometimes referred to as “PVA-based resin film”) in which a dichroic dye such as iodine is adsorbed and oriented, and the PVA-based resin film is Usually, it is an extended|stretched extending|stretching polyvinyl alcohol-type resin film. As for the polarizing layer 41, the dichroic dye may be oriented in the layer which the liquid crystal compound hardened|cured. The first protective layer 42 and the second protective layer 43 are layers for protecting the polarizing layer 41 . A retardation film may be sufficient as the 1st retardation layer 21, and the liquid crystal layer containing a liquid crystal compound may be sufficient as it. The liquid crystal layer may be, for example, a cured layer formed by polymerization of a polymerizable liquid crystal compound. When the first retardation layer 21 is a liquid crystal layer, the optical laminate 11 is a liquid crystal compound forming the first retardation layer 21 on the opposite side to the pressure-sensitive adhesive layer 31 of the first retardation layer 21 . You may have an orientation layer for orientating the.

The optical layered body 11 has a glue-deficient part 5 at the edge part in the plane direction W. As shown in FIG. As shown in FIG. 1 , the lack of glue 5 is a cross-section through which the polarizing layer 41 and the pressure-sensitive adhesive layer 31 pass through the overlapping portion in the lamination direction orthogonal to the plane direction W, It is formed so that the position of the innermost end in the edge part of the adhesive layer 31 may be located inside by the length of the distance L1 from the position of the outermost end in the edge part 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 innermost position among the end portions of the pressure-sensitive adhesive layer 31 in the plane direction W, and the end portion of the polarizing layer 41 . The position of the outermost end in , refers to a position at the outermost end in the plane direction (W) among the ends of the polarizing layer 41 .

The distance L1 of the grass absence region 5 is 3 µm or more, preferably 5 µm or more, and may be 6 µm or more, 7 µm or more, or 8 µm or more. In addition, distance L1 may be 120 micrometers or less normally, 100 micrometers or less may be sufficient, 75 micrometers or less may be sufficient, 50 micrometers or less may be sufficient, and 25 micrometers or less may be sufficient as it.

The polarizing plate 40 included in the optical laminate 11 has a polarizing layer 41 . The polarizing layer 41 may shrink under a high-temperature environment. Therefore, when the optical laminate 11 is exposed to a high-temperature environment, the first retardation layer laminated on the polarizing plate 40 through the pressure-sensitive adhesive layer 31 due to contraction of the polarizing layer 41 (polarizing plate 40 ). It is considered that the shrinkage stress of the polarizing layer 41 is concentrated at the end of (21). When the shrinkage stress is concentrated at the end of the first retardation layer 21 , the color of the reflected light at the end of the optical laminate 11 and the color of the light other than the end of the optical laminate 11 due to the effect of the photoelasticity of the first retardation layer 21 . It is estimated that the difference in the hue of the partial reflected light 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 glue-deficient portion 5 of the optical laminate 11 is 3 µm or more. Thereby, since it is easy to disperse the shrinkage stress of the polarizing layer 41 when the optical laminate 11 is exposed to a high-temperature environment, the shrinkage stress applied to the end of the first retardation layer 21 can be reduced. have. As a result, due to the effect of the photoelasticity of the first retardation layer 21, the difference between the color of the reflected light at the end of the optical laminate 11 and the color of the reflected light at other parts than the end can be reduced. For this reason, it is thought that it can suppress that the uniformity of the hue of the reflected light in the surface of the optical laminated body 11 deteriorates.

In addition, if the distance L1 of the glue-deficient portion 5 in the optical laminate 11 is too large, the adhesion area between the polarizing plate 40 and the first retardation layer 21 becomes small, so that the end portion during the high-temperature durability test is It peels off, and it becomes easy to generate|occur|produce defects, such as a bubble.

The effect of the shrinkage of the polarizing layer 41 under a high-temperature environment is greater than that of the polarizing layer 41 in which the dichroic dye is oriented in the layer in which the liquid crystal compound is cured, the dichroic dye is adsorbed to the PVA-based resin film. In the case of a polarizing layer which is oriented, it tends to become remarkable especially in the case of a polarizing layer formed by making a PVA-type resin film adsorb|suck a dichroic dye by dyeing|staining and then extending|stretching. Therefore, when a dichroic dye is used as the polarizing layer 41 in which the dichroic dye is adsorbed and oriented on the PVA-based resin film, by making the distance L1 from the grass-free region 5 3 μm or more, the optical laminate ( The deterioration of the color uniformity of the reflected light in the plane of 11) can be more suitably suppressed.

The distance L1 of the glue-free portion 5 is the maximum at the end of the pressure-sensitive adhesive layer 31 determined based on the profile of the cross-section using a laser microscope for the cross-section of the optical laminate 11 and determined based on this profile. It can be calculated based on the position of the inner end and the position of the outermost end in the end of the polarizing layer 41. When the outer shape of the optical laminate 11 has a straight side, and a glue-deficient portion 5 is formed on the side, the cross section of the optical laminate 11 has a glue-free portion 5 on the side In the position where it is formed, let it be the cross section when it cut|disconnects along the direction perpendicular|vertical with respect to the said side. In addition, when the outer shape of the optical laminate 11 has a curved portion, and the glue-deficient portion 5 is formed in the curved portion, the cross section of the optical laminate 11 has the glue-free portion 5 It is set as the cross section at the time of passing through the position P of the tangent line of the surface direction of the optical laminated body 11 at the formed position P, and cutting|disconnecting along the direction perpendicular to the said tangent line.

The shape of the glue absence part 5 in the optical laminated body 11 is not specifically limited, The edge part of the adhesive layer 31 may have a tapered shape as shown in FIG. 1, The surface direction W It may be parallel to the lamination direction orthogonal to , and may be formed in a sawtooth shape, an uneven|corrugated shape, a curved shape, etc. 1, the position of the edge part of the surface on the side of the polarizing plate 40 is the 1st phase difference layer 21 side of the adhesive layer 31, as for the adhesive layer 31 in the glue absence part 5, as shown in FIG. The position of the end of the surface of the surface direction is inward, the shape may be tapered, and on the contrary, the position of the end of the surface on the side of the polarizing plate 40 is the first retardation layer of the pressure-sensitive adhesive layer 31 It is out of the surface direction from the position of the edge part of the surface on the side (21), and the shape may be a tapered shape. In the case of the latter tapered shape, since the shrinkage stress of the polarizing layer 41 in a high-temperature environment tends to be dispersed, it is considered that it is easy to suppress deterioration of the color uniformity of the reflected light in the plane of the optical laminate 11 .

The outer shape of the optical laminate 11 can be a quadrangle in the planar direction (planar view), or a quadrangle having a notch on at least one side. In the present specification, a quadrangle refers to a rectangle or a square, and includes at least one of the four angles of the quadrangle rounded.

In addition, let the boundary of two sides continuous through a rounding part be a position which bisects the outline length of a rounding part. The contour length of the rounding portion is defined as the length between the ends positioned on the rounding portion side of the straight portion each of two sides continuous through the rounding portion has. Examples of the notch include a concave shape concave toward opposite sides, and the concave shape may be a U-shape or a V-shape.

The notch may be formed in one side of a quadrangle, and may be formed in two or more sides. The cutout may be formed in an area where at least one of a handset, a speaker, a camera lens, an LED lamp, a proximity sensor, an illuminance sensor, a fingerprint authentication sensor, an operation button, etc. is installed in, for example, a smartphone.

When the optical laminated body 11 is a quadrangle, it is preferable that the glue absence part 5 is formed in at least one side of a quadrangle, and may be formed in two or more sides, and may be formed in all four sides. In addition, the glue absence part 5 may be formed continuously or discontinuously over the full length of a side, and may be formed in a part of a side. In addition, the glue absence part 5 may be formed in at least one part of a notch, and may be formed in the whole notch.

The optical laminated body 11 may have a hole part which penetrates the optical laminated body 11 whole in the lamination|stacking direction. A hole may be circular, and polygons, such as an ellipse, a square, and a hexagon, may be sufficient as it, and at least one of polygonal angles may be rounded. In the peripheral portion of the hole, a glue-free portion 5 may be formed. The glue-free portion formed in the hole may be formed in at least a part of the peripheral portion of the hole, or may be formed in the entire peripheral portion of the hole. The hole may be formed, for example, in a region where a camera lens or the like is installed in a smartphone or the like.

The optical laminate 11 has a quadrangle, the quadrangle having a pair of long sides and a pair of short sides, and the absorption axis direction of the polarizing layer 41 is at an angle of 45°±10° with respect to the long side. When forming, it is preferable that the glue-free part 5 is formed in at least one of a pair of long sides, and at least one of a pair of short sides. In the present specification, the angle refers to an acute angle among angles between the absorption axis direction and the long side. The glue-free part 5 may be formed on both sides of a pair of long sides, and may be formed on both sides of a pair of short sides. When the polarizing layer 41 of the optical laminate 11 is exposed to a high-temperature environment, it tends to contract in the absorption axis direction, so that the shrinkage stress of the polarizing layer 41 is concentrated on sides located at both ends in the absorption axis direction. easy to become Therefore, in the optical layered body 11 in which the absorption axis direction and the long side are in a relationship of 45°±10°, the shrinkage stress of the polarizing layer 41 is likely to be concentrated on both the long side and the short side, and the first phase difference It is considered that the color of the reflected light of the layer 21 is likely to change. As described above, when the optical laminate 11 is exposed to a high-temperature environment, the polarizing layer 41 is formed by forming the glue-deficient portion 5 on at least one of the pair of long sides and at least one of the pair of short sides. In a portion where the shrinkage stress is likely to be concentrated, the shrinkage stress can be dispersed. Thereby, even when the optical laminated body 11 is exposed to a high-temperature environment, it is thought that it can suppress effectively that the uniformity of the hue of the reflected light in a plane deteriorates. 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 quadrangle, the quadrangle having a pair of long sides and a pair of short sides, and the absorption axis direction of the polarizing layer 41 is at an angle of 0°±10° with respect to the long side. When forming, it is preferable that the glue-free portion 5 is formed on at least one of the pair of short sides. In the present specification, the angle refers to an acute angle among angles between the absorption axis direction and the long side. The grass-free portion 5 may be formed on both sides of a pair of short sides. In the optical laminate 11 in which the absorption axis direction and the long side are in a relationship of 0°±10°, for the above reason, the shrinkage stress of the polarizing layer 41 is likely to be concentrated on the short side, and the first retardation layer ( It is thought that the color of the reflected light of 21) is easy to change. Therefore, by forming the glue-deficient portion 5 on at least one of the pair of short sides, it is effectively suppressed from deterioration of the color uniformity of the reflected light in the plane even when the optical laminate 11 is exposed to a high-temperature environment. I think you can do it. 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 quadrangle, the quadrangle having a pair of long sides and a pair of short sides, and the absorption axis direction of the polarizing layer 41 is an angle of 0°±10° with respect to the short side. When forming, it is preferable that the glue-free part 5 is formed in at least one of a pair of long sides. In the present specification, the angle refers to an acute angle among angles between the absorption axis direction and the short side. The glue-free part 5 may be formed on both sides of a 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°, for the above reason, the shrinkage stress of the polarizing layer 41 on the long side tends to be concentrated, and the first retardation layer ( It is thought that the color of the reflected light of 21) is easy to change. Therefore, by forming the glue-deficient portion 5 on at least one of the pair of long sides, even when the optical laminate 11 is exposed to a high-temperature environment, it is effectively suppressed from deterioration of the color uniformity of the reflected light in the plane. I think you can do it. The angle formed with respect to the short side of the absorption axis of the polarizing layer 41 may be 0°±5°, 0°±2°, or 0°.

In the optical laminated body 11 shown in FIG. 1, the A plate may be sufficient as the 1st retardation layer 21, and the C plate may be sufficient as it. Moreover, in the optical laminated body 11 shown in FIG. 1, it can be set as a circularly polarizing plate by making the 1st phase difference layer 21 into a quarter wave plate.

The optical laminate 11 shown in FIG. 1 prepares, for example, the polarizing plate 40 and the 1st retardation layer 21, the 1st protective layer 42 side of the polarizing plate 40, and the 1st retardation It can be manufactured by apply|coating or transferring an adhesive on at least one of the layers 21, and bonding the polarizing plate 40 and the 1st retardation layer 21 through the layer of an adhesive. When the first retardation layer 21 is a liquid crystal layer, the first retardation layer 21 of the first retardation layer with a base material layer in which the first retardation layer 21 is formed so as to be peelable on the first base material layer; After laminating the polarizing plate 40 through an adhesive, the first base layer may be peeled off.

Although the method of forming the glue absence part 5 in the optical laminated body 11 is not specifically limited, For example, it can form by adjusting the application range and transfer position of the adhesive layer for forming the adhesive layer 31. have. When the pressure-sensitive adhesive layer 31 is formed by transfer, a portion serving as the glue-free area 5 is formed in the pressure-sensitive adhesive layer formed on a release film or the like prepared for transfer, and the glue-free area 5 is You may make it transcribe|transfer the adhesive layer in which the part used as a part was formed on the polarizing plate 40 or the 1st phase difference layer 21.

In order to form the portion serving as the glue-free portion 5 in the pressure-sensitive adhesive layer formed on the release film or the like, for example, as shown in FIGS. It can be formed by preparing the pressure-sensitive adhesive layer 60 with a release film having 61 formed thereon, and 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 . have. In the process of cutting the pressure-sensitive adhesive layer 60 with a release film in this way, the pressure-sensitive adhesive layer 61 is press-fitted in a tapered shape by the side on which the blade is formed among both surfaces of the single-edged cutting blade 65, and the end portion It is possible to form a pressure-sensitive adhesive layer having a tapered shape.

(variant example)

The optical film of this embodiment may be changed like the modification shown below, and can also be implemented combining each structure and each process of embodiment and its modification.

(Modification 1)

Although the said embodiment demonstrated the optical laminated body 11 which has the polarizing plate 40 which has the 1st protective layer 42 and the 2nd protective layer 43 on both surfaces of the polarizing layer 41, it is limited to this doesn't happen The polarizing plate may include the polarizing layer 41 and either the first protective layer 42 or the second protective layer 43 . In addition, in the optical laminated body 11, the 1st protective layer 42 and the 2nd protective layer 43 may not be included.

(Modification 2)

When the optical laminate 11 shown in FIG. 1 is a circularly polarizing plate, this circularly polarizing plate can be used for reflection prevention of an organic electroluminescent (organic EL) display apparatus, for example. In this case, the optical laminated body 11 is used by bonding to the visual recognition side of the optical display element of an organic electroluminescent display. Therefore, the optical laminated body 11 may have the adhesive layer for optical display elements for bonding to an optical display element on the opposite side to the adhesive layer 31 of the 1st phase difference layer 21. As shown in FIG.

(Modified example 3)

Although the said embodiment demonstrated the optical laminated body 11 containing the 1st retardation layer 21, it is not limited to this, For example, the optical laminated body shown in FIG. 2 may be sufficient. 2 : is sectional drawing which shows typically the other example of the optical laminated body of this embodiment. In the following, the same reference numerals are assigned to the same members as those described above, and descriptions thereof are omitted. The optical laminated body 12 shown in FIG. 2 has the polarizing plate 40, the adhesive layer 31, the 1st retardation layer 21, the adhesive layer 35, and the 2nd retardation layer 22 in this order. . An adhesive layer formed using an adhesive may be sufficient as the adhesive layer 35, and the adhesive bond layer formed using an adhesive may be sufficient as it. 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 aligns the liquid crystal compound constituting the second retardation layer 22 on the opposite side to the adhesive layer 35 of the second retardation layer 22 . You may have an orientation layer for making it do this.

In the optical laminate 12, the first retardation layer 21 is a half-wave plate and the second retardation layer 22 is a quarter-wave plate; using the first retardation layer 21 as a quarter-wave plate having reverse wavelength dispersion and the second retardation layer 22 as a positive C plate; A circularly polarizing plate can be obtained by using the first retardation layer 21 as a positive C plate and the second retardation layer 22 as a quarter-wavelength plate having reverse wavelength dispersion. When the combination of the first retardation layer 21 and the second retardation layer 22 is a 1/2 wave plate and a 1/4 wave plate, the 1/2 wave plate is delayed with respect to the absorption axis direction of the polarizing layer 41 . The axial direction may be 70° to 80°, and the slow axis direction of the quarter wave plate can be 10° to 20°. In addition, when the combination of the first retardation layer 21 and the second retardation layer 22 is a quarter wave plate having reverse wavelength dispersion and a positive C plate, it 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 an organic EL display device, the optical laminate 12 shown in FIG. 2 is different from the adhesive layer 35 of the second retardation layer 22. You may have the adhesive layer for optical display elements on the opposite side.

The optical laminate 12 shown in FIG. 2 includes, for example, a retardation layer laminate in which a first retardation layer 21 and a second retardation layer 22 are laminated via an adhesive layer 35, and a polarizing plate 40. Prepare, apply or transfer an adhesive 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, the polarizing plate 40 and the retardation layer It can be formed by bonding a laminated body through an adhesive. When both the 1st retardation layer 21 and the 2nd retardation layer 22 are liquid crystal layers, the optical laminated body 12 can be obtained as follows, for example. First, the 1st retardation layer 21 of the 1st retardation layer with a base material layer in which the 1st retardation layer 21 was formed so that peeling was possible on the 1st base material layer, and the 2nd retardation of the 2nd base material layer so that peeling was possible. The 2nd retardation layer 22 of the 2nd retardation layer with a base material layer in which the layer 22 was formed is laminated|stacked through a contact bonding layer, and the retardation layer laminated body is obtained. Next, the first base layer is peeled 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 through an adhesive, and then the second base material By peeling a layer, the optical laminated body 12 shown in FIG. 2 can be obtained.

Hereinafter, each matter common in the said embodiment and its modification is demonstrated in detail.

(polarization layer)

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

A PVA-type resin film is a film formed using polyvinyl alcohol-type resin. Polyvinyl alcohol-type resin means resin which contains 50 mass % or more of structural units derived from vinyl alcohol. As polyvinyl alcohol-type resin, what saponified polyvinyl acetate-type resin can be used. The saponification degree of polyvinyl acetate-type resin can be calculated|required based on JISK6727 (1994), and can be set as the range of 80.0-100.0 mol%, for example.

As polyvinyl acetate-type resin, polyvinyl acetate which is a homopolymer of vinyl acetate, the copolymer of vinyl acetate, and other monomer copolymerizable with this, etc. are mentioned. Examples of the other monomer copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth)acrylamides having an ammonium group. In this specification, "(meth)acryl" represents at least 1 sort(s) chosen from the group which consists of acryl and methacryl. The same applies to other terms appended with "(meth)".

The unstretched film formed by forming a polyvinyl alcohol-type resin into a film may be sufficient as an example of a PVA-type resin film, and the stretched film which stretched this unstretched film may be sufficient as it. When a PVA-type resin film is a stretched film, it is preferable that it is a longitudinal uniaxially stretched stretched film, and it is preferable that it is a dry stretched stretched film. The draw ratio in case a PVA-type resin film is a stretched film is 1.1-8 times normally.

Iodine, organic dye, etc. are mentioned as a dichroic dye currently adsorb|suction orientation to the PVA-type resin film. Organic dyes include, for example, 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, 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, etc. are mentioned. A dichroic dye may be used individually by 1 type, and may use 2 or more types together.

Examples of the polarizing layer in which the dichroic dye is oriented in the layer in which the liquid crystal compound is cured includes a cured layer obtained by aligning the dichroic dye in a polymerizable liquid crystal compound and polymerizing the polymerizable liquid crystal compound. Such a polarizing layer can be formed by coating a composition for forming a polarizing layer including 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. The polarizing layer obtained in this way exists in the state laminated|stacked on the base film, and may use a base film as a protective layer of a polarizing layer as it is. Or after laminating|stacking the polarizing layer with a base film which made it possible to peel a base film with respect to a polarizing layer through the adhesive layer 31 on 1st retardation layer, you may peel a base film.

What is necessary is just to have the property which shows a liquid-crystal state as a liquid-crystal compound, and since it can exhibit high polarization|polarized-light performance especially, what has a high-order orientation state, such as a smectic phase, is preferable.

Moreover, it is also preferable that the liquid crystal compound has a polymerizable functional group. A dichroic dye is a dye which orientates together with a liquid crystal compound and shows dichroism, and the dichroic dye itself may have liquid crystallinity, and may have a polymerizable functional group. Any compound in the composition for forming a polarizing layer including a liquid crystal compound has a polymerizable functional group.

Examples of the dichroic dye that can be used in 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. desirable. As an azo dye, a monoazo dye, a bisazo dye, a trisazo dye, a tetrakis azo dye, a stilbenazo dye, etc. are mentioned, A bisazo dye and a trisazo dye are more preferable. A dichroic dye may be used individually by 1 type, and may use 2 or more types together.

The composition for forming a polarizing layer may include a solvent, polymerization initiator such as a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a dispersant, a leveling agent, a stabilizer, a surfactant, a crosslinking agent, a silane coupling agent, and the like. A well-known thing can be used about the polymerizable liquid crystal compound, a dichroic dye, a solvent, a polymerization initiator, a photosensitizer, a polymerization inhibitor, etc. contained in the composition for polarizing layer formation. In addition, as a polymeric liquid crystal compound, you may use the thing similar to the compound illustrated as a polymeric liquid crystal compound used in order to obtain the 1st retardation layer and 2nd retardation layer mentioned later.

The thickness of the polarizing layer 41 is usually 2 to 40 µm, and from the viewpoint of thinning the polarizing layer, it is preferably 30 µm or less, and more preferably 20 µm or less. Among the layers in which the liquid crystal compound is cured, the polarizing layer in which the dichroic dye is oriented can 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. 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.

Moreover, it is preferable that it is 40-47 %, and, as for the visibility correction|amendment single transmittance|permeability Ty of the polarizing layer 41, it is preferable that it is 40-47 %, and it is more preferable that it is 41-45 % in consideration of the balance with the visibility correction|amendment polarization degree Py. It is preferable that it is 99.9 % or more, and, as for visibility correction|amendment polarization degree Py, it is more preferable that it is 99.95 % or more. Ty and Py can be calculated|required by performing visibility correction|amendment with the 2 degree field of view (C light source) of JISZ8701 with respect to the transmittance|permeability and polarization degree obtained using the absorptiometer with an integrating sphere.

(Polarizer)

A polarizing plate laminates|stacks the protective layer (1st protective layer, 2nd protective layer) on one side or both surfaces of a polarizing layer via a well-known adhesive layer or adhesive bond layer. The thickness of the polarizing plate may be, for example, 2 µm or more and 300 µm or less, may be 10 µm or more, and may be 150 µm or less, may be 120 µm or less, or may be 80 µm or less.

As the protective layer, for example, a film formed of a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, stretchability, and the like is used. As a specific example of such a thermoplastic resin, Cellulose resins, such as a triacetyl cellulose; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyether sulfone resin; polysulfone resin; polycarbonate resin; polyamide resins such as nylon and aromatic polyamide; polyimide resin; polyolefin resins such as polyethylene, polypropylene, and ethylene/propylene copolymer; cyclic polyolefin resins having a cyclo-based and norbornene structure (also referred to as norbornene-based resins); (meth)acrylic resin; polyarylate resin; polystyrene resin; polyvinyl alcohol resins and mixtures thereof. When the protective layer is laminated|stacked on both surfaces of a polarizing layer, the resin composition of two protective layers may be same or different. The film formed of the thermoplastic resin may be subjected to surface treatment (eg, corona treatment, etc.) in order to improve adhesion with the polarizing layer, or 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, the thermoplastic resin stretched, or may not be stretched (hereinafter referred to as "unstretched resin" in some cases). As an extending|stretching process, uniaxial stretching, biaxial stretching, etc. are mentioned.

It is preferable that it is 3 micrometers or more, and, as for the thickness of a protective layer, it is more preferable that it is 5 micrometers or more. Moreover, it is preferable that it is 50 micrometers or less, and, as for the thickness of a protective layer, it is more preferable that it is 35 micrometers or less. Moreover, the above-mentioned upper limit and lower limit can be combined arbitrarily. As the thickness of the polarizing plate becomes thinner, the rigidity decreases, and it becomes easier to be affected by the shrinkage stress of the polarizing layer. Therefore, in an optical laminate in which the polarizing plate has a protective layer with a small thickness, it is easily affected by the shrinkage stress of the polarizing layer at the end thereof, and the color uniformity of in-plane reflected light tends to deteriorate under a high-temperature environment. . Therefore, in such an optical laminate, it is thought that, as described above, by making the distance L1 between the gaps without grass to be 3 µm or more, it is possible to effectively suppress deterioration of the color uniformity of the in-plane reflected light even under a high-temperature environment. .

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

(1st retardation layer and 2nd retardation layer)

A retardation film may be sufficient as a 1st retardation layer and a 2nd retardation layer (Hereinafter, both may be collectively called "retardation layer"), or a liquid crystal layer may be sufficient as it. The retardation film should just show optical anisotropy, for example, polyvinyl alcohol, polycarbonate, polyester, polyarylate, polyimide, polyolefin, polycycloolefin, polystyrene, polysulfone, polyethersulfone, polyvinylidene fluoride. / The stretched film obtained by extending|stretching the film formed from polymethyl methacrylate, acetyl cellulose, the saponified ethylene-vinyl acetate copolymer, polyvinyl chloride, etc. to about 1.01-6 times, etc. are mentioned.

When the retardation layer is a liquid crystal layer, the type of the liquid crystal compound constituting 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 may be used. The liquid crystal layer is a cured layer of the liquid crystal compound by applying a liquid crystal layer forming composition including a liquid crystal compound, a solvent, and, if necessary, various additives on the alignment layer to form a coating film, and solidifying (curing) the coating film. A liquid crystal layer may be formed. Alternatively, the liquid crystal layer may be formed by applying the composition for forming a liquid crystal layer on the base layer to form a coating film, and stretching the coating film together with the base layer. The composition for liquid crystal layer formation may contain the polymerization initiator, a reactive additive, a leveling agent, a polymerization inhibitor, etc. other than the said liquid crystal compound and the solvent. A liquid crystal compound, a solvent, a polymerization initiator, a reactive additive, a leveling agent, a polymerization inhibitor, etc. can use a well-known thing suitably.

As a base material layer (1st base material layer, 2nd base material layer) in which a liquid crystal layer is formed, it is preferable that it is a film formed of the resin material. As the resin material, for example, a resin material excellent in transparency, mechanical strength, thermal stability, stretchability, and the like is used. Specifically, polyolefin resins, such as polyethylene and a polypropylene; Cyclic polyolefin-type resin, such as a norbornene-type polymer; polyester-based resins such as polyethylene terephthalate and polyethylene naphthalate; (meth)acrylic acid-based resins such as (meth)acrylic acid and poly(meth)methyl acrylate; cellulose ester-based resins such as triacetyl cellulose, diacetyl cellulose and cellulose acetate propionate; vinyl alcohol-based resins such as polyvinyl alcohol and polyvinyl acetate; polycarbonate-based resin; polystyrene-based resin; polyarylate-based resin; polysulfone-based resin; polyether sulfone-based resin; polyamide-based resin; polyimide-based resin; polyether ketone-based resin; polyphenylene sulfide-based resin; and polyphenylene oxide-based resins and mixtures and copolymers thereof. Among these resins, it is preferable to use any of a cyclic polyolefin-based resin, a polyester-based resin, a cellulose ester-based resin, and a (meth)acrylic acid-based resin, or a mixture thereof.

A single layer may be sufficient as a base material layer, and it may have a multilayer structure of two or more layers. When it has a multilayer structure, the kind of resin which comprises each layer may mutually be same or different. Although the thickness of a base material layer is not specifically limited, Generally, it is preferable from the point of workability, such as intensity|strength and handling property, that it is 1-300 micrometers, It is more preferable that it is 10-200 micrometers, It is still more preferable that it is 30-120 micrometers. do.

The said alignment layer has the alignment control force which liquid-crystal-aligns liquid crystal compounds, such as a polymeric liquid crystal compound, contained in the liquid crystal layer formed thereon in a desired direction. Examples of the alignment layer include an alignment polymer layer formed of an alignment polymer, a photo alignment polymer layer formed of a photo alignment polymer, and a groove alignment layer having an uneven pattern or a plurality of grooves on the surface of the layer. The thickness of the alignment layer is usually 10-500 nm, preferably 10-200 nm.

(Adhesive layer)

An adhesive layer is a layer formed using an adhesive. In this specification, adhesiveness is expressed by coat|covering itself to to-be-adhered bodies, such as an optical film and a liquid-crystal layer, with an adhesive, and what is called a so-called pressure-sensitive adhesive. As the pressure-sensitive adhesive, a conventionally known pressure-sensitive adhesive having excellent optical transparency can be used without any particular limitation, and for example, an adhesive having a base polymer such as acrylic, urethane, silicone, or polyvinyl ether-based pressure-sensitive adhesive can be used. 3 micrometers or more may be sufficient as the thickness of an adhesive layer, 5 micrometers or more may be sufficient, and 35 micrometers or less may be sufficient as it, and 30 micrometers or less may be sufficient as it.

The pressure-sensitive adhesive layer may contain additives such as ultraviolet absorbers, antistatic agents using ionic compounds, solvents, crosslinking catalysts, tackifying resins (tackifiers), plasticizers, softeners, dyes, pigments, and inorganic fillers. In particular, when a 1st retardation layer is a liquid-crystal layer, it can suppress that the liquid-crystal compound contained in a liquid-crystal layer receives the influence of external light etc., and deteriorates especially by containing an ultraviolet absorber.

(Adhesive layer)

The adhesive layer can be formed by a pressure-sensitive adhesive layer, an adhesive layer formed using an adhesive, and a combination thereof, and is usually one layer, but may be two or more layers. When an adhesive layer consists of two or more layers, each layer may be formed from the mutually same material, and may be formed from different materials. The pressure-sensitive adhesive layer may be formed using the pressure-sensitive adhesive.

As the adhesive that can be used for the adhesive layer, for example, a conventionally known adhesive such as a water-based adhesive or an active energy ray-curable adhesive can be used without particular limitation. Examples of the water-based adhesive include a polyvinyl alcohol-based resin aqueous solution and a water-based two-component urethane-based emulsion adhesive. The active energy ray-curable adhesive is an adhesive that is cured by irradiating active energy rays such as ultraviolet rays, for example, a polymerizable compound and a photopolymerizable initiator, a photoreactive resin, a binder resin, and a photoreactive crosslinking agent. Including, etc. are mentioned. Examples of the polymerizable compound include photopolymerizable monomers such as photocurable epoxy monomers, photocurable acrylic monomers and photocurable urethane monomers, and oligomers derived from these monomers. Examples of the photopolymerization initiator include those containing a substance that generates active species such as neutral radicals, anionic radicals and cationic radicals by irradiating active energy rays such as ultraviolet rays.

Example

Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated more concretely, this invention is not limited by these examples. "%" and "part" in an Example and a comparative example are mass % and mass part, unless otherwise indicated.

[Production of Polarizer]

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

Further, with respect to 100 parts by weight of water, 3 parts by weight of carboxyl group-modified polyvinyl alcohol [trade name "KL-318" obtained from Kuraray Co., Ltd.] was dissolved in the aqueous solution, and a polyamide epoxy resin additive [Daoka] 1.5 parts by weight of "Sumirez Resin (registered trademark) 650 (30)," an aqueous solution having a solid content concentration of 30% by weight] obtained from Chemical Industry Co., Ltd. was added to prepare a water-based adhesive.

The first protective layer was saponified, and the surface of the second protective layer on the norbornene-based resin film side and both surfaces of the polarizing layer were corona treated. On one side of the polarizing layer, the first protective layer is bonded through the water-based adhesive obtained above, and on the other side of the polarizing layer, the opposite side (norther) from the hard coat layer of the second protective layer through the same water-based adhesive as above. Bonene-type resin film side) was bonded, the drying process was carried out, and the polarizing plate was produced. The obtained polarizing plate was cut into a rectangle so that the absorption axis of a polarizing layer might become 45 degrees with respect to the long side direction.

[Production of the first retardation layer]

(Preparation of a composition for forming a horizontal alignment layer)

The composition for horizontal alignment layer formation was obtained by mixing the following component and stirring the obtained mixture at the temperature of 80 degreeC for 1 hour.

·Light orientation material (5 parts) (weight average molecular weight: 30000):

·Solvent (95 parts): cyclopentanone

(Preparation of a composition for forming a horizontally aligned liquid crystal layer)

The following components were mixed, N-methyl-2-pyrrolidone (NMP) was further added so that solid content concentration might be 13%, and the composition for horizontal alignment liquid crystal layer formation was obtained by stirring at 80 degreeC for 1 hour. The following polymerizable liquid crystal compound A was synthesized by the method described in Japanese Patent Application Laid-Open No. 2010-31223, and the following polymerizable liquid crystal compound B was synthesized according to the method described in Japanese Patent Application Laid-Open No. 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)butan-1-one (Irgacure 369, manufactured by BASF Japan Co., Ltd.)

(Preparation of the first retardation layer)

The cyclic olefin resin (COP) film (ZF-14-50, Nippon Zeon Co., Ltd. make) was corona-treated. On the corona-treated surface of this COP film, the composition for forming a horizontal alignment layer obtained above was applied with a bar coater, and dried at 80°C for 1 minute. With respect to this coating film, using a polarized UV irradiation device ("SPOT CURE SP-9", manufactured by Ushio Electric Co., Ltd.), polarized UV light at an axis angle of 45° so that the accumulated light amount at a wavelength of 313 nm is 100 mJ/cm 2 was exposed to obtain a horizontal alignment layer.

Then, to this horizontal alignment layer, the composition for horizontal alignment liquid crystal layer formation obtained above was apply|coated using the bar coater, and it was made to dry at 120 degreeC for 1 minute. By irradiating ultraviolet rays to the coating film using a high-pressure mercury lamp (“Unicure VB-15201BY-A”, manufactured by Ushio Electric Co., Ltd.) (in a nitrogen atmosphere, accumulated light quantity at a wavelength of 365 nm: 500 mJ/cm 2 ) , a first phase difference layer that is a horizontally aligned liquid crystal layer was formed. The first phase difference layer was a quarter-wave plate showing reverse wavelength dispersion.

[Preparation of second retardation layer]

(Preparation of composition for forming a vertical alignment layer)

As a composition for forming a vertical alignment layer, Saneva SE610 (manufactured by Nissan Chemical Industry Co., Ltd.) was prepared.

(Preparation of a composition for forming a vertically aligned liquid crystal layer)

The following components were mixed, cyclopentanone was further added so that solid content concentration might be 13 %, and the composition for vertical alignment liquid crystal layer formation was obtained.

・Polymerizable liquid crystal compound C (100 parts):

Paliocolor (registered trademark) LC242 (manufactured by BASF)

·Leveling agent (0.1 parts):

F-556 (manufactured by DIC)

·Polymerization initiator (3 parts):

Irgacure 369 (manufactured by Chiba Specialty Chemicals)

(Preparation of the second retardation layer)

The cyclic olefin resin (COP) film (ZF-14-50, Nippon Zeon Co., Ltd. make) was corona-treated. On the corona-treated surface of this COP film, the composition for forming a vertical alignment layer obtained above was applied with a bar coater, and dried at 80° C. for 1 minute to obtain a vertical alignment layer. Then, the composition for forming a vertically aligned liquid crystal layer obtained above was applied to the vertical alignment layer using a bar coater, and dried at 90°C for 120 seconds. This coating film was irradiated with ultraviolet rays using a high-pressure mercury lamp ("Unicure VB-15201 BY-A", manufactured by Ushio Electric Co., Ltd.) (in a nitrogen atmosphere, accumulated light quantity at a wavelength of 365 nm: 500 mJ/cm2) By doing so, the 2nd retardation layer which is a vertically aligned liquid crystal layer was formed. The second retardation layer was a positive C plate that satisfies the relationship of nx≒ny<nz.

[Production of retardation layer laminate]

The corona treatment was performed on the surface on the opposite side to the COP film of the 1st retardation layer produced above, and the surface on the opposite side to the COP film of the 2nd retardation layer produced above. After bonding the corona-treated surfaces (the surface of the first retardation layer and the surface of the second retardation layer) to each other through an ultraviolet curable adhesive, the ultraviolet curable adhesive is cured by irradiating ultraviolet rays to cure the first retardation layer and the second retardation layer The retardation layer laminated body laminated|stacked through this adhesive bond layer was obtained. The obtained retardation layer laminate was cut into a rectangle so that the slow axis of a 1st retardation layer (1/4 wave plate) might become parallel to a long side direction.

[Measurement of the distance L1 of the absence of grass]

An acrylic pressure-sensitive adhesive layer having a thickness of 20 µm formed on a release film was laminated on the second retardation layer side of the optical laminate obtained in each of Examples and Comparative Examples to obtain an optical laminate with a pressure-sensitive adhesive layer. Regarding this optical laminate with an adhesive layer, when the side on which the adhesive layer is formed is checked, and the adhesive layer is cut along the direction perpendicular to the side at the position where the adhesive layer is formed of the cross-section, the profile was measured using a laser microscope. Based on the measured profile, the distance L1 between the position of the innermost end in the edge part of the adhesive layer 61, and the position of the outermost end in the edge part of the polarizing layer was measured.

[High Temperature Test]

An acrylic pressure-sensitive adhesive layer having a thickness of 20 µm was laminated on the second retardation layer side of the optical laminate obtained in each of Examples and Comparative Examples, and this acrylic pressure-sensitive adhesive layer was bonded to a glass plate to obtain a sample for evaluation.

The high temperature test which puts the obtained sample for evaluation in the oven of the temperature of 80 degreeC for 200 hours was done. The evaluation sample after the high temperature test was placed on a reflecting plate (manufactured by Alanod, MIRO5 5011GP) so that the glass plate was at the lower side, and the color of the reflected light was measured using a spectrophotometer (CM2600d, Konica Minolta Co., Ltd.). The measurement is performed by wearing a mask having a diameter phi of 1.5 mm of the opening when light enters the integrating sphere from the evaluation sample, and the color (a*b) of the reflected light from the four end sides of the evaluation sample. *) and the average value of the difference between the hue (a*b*) of the reflected light of the central portion (intersecting portion of the diagonal of a rectangle) of the evaluation sample was calculated as Δa*b*.

Δa*b*=(Δa* ² +Δb* ² ) ^1/2

In addition, after placing the evaluation sample after the high temperature test on a reflective plate (manufactured by Alanod, MIRO5 5011GP), the reflected light was observed visually from the optical laminate side to evaluate the visibility to confirm the state of color non-uniformity of the optical laminate. The state of color nonuniformity evaluated the case where it visually recognized weakly as A, and evaluated the case where it was strongly visually recognized as B.

[Example 1]

Fig.3 (a) and (b) is a schematic diagram for demonstrating the manufacturing method of the adhesive layer in an Example. As shown in Fig. 3A, on the release film 62, a pressure-sensitive adhesive layer 60 with a release film having a pressure-sensitive adhesive layer 61 formed 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. 3 (a), from the pressure-sensitive adhesive layer 61 side, along a direction parallel to the lamination direction of the pressure-sensitive adhesive layer 60 with a release film (arrow direction in the drawing), the tip portion 65a of The cutting blade 65 of the angle (theta) was cut, and the adhesive layer 60 with a peeling film was cut into rectangle. In addition, as the cutting blade 65, the thing of a single blade was used. The cut surface of the rectangular adhesive layer 60 with a peeling film after cutting was the surface which contacted the surface in which the blade was formed among both surfaces of the cutting blade 65 of a single blade.

After bonding the adhesive layer 61 of the obtained rectangular adhesive layer 60 with a peeling film to the 1st protective layer side (triacetyl cellulose film side) of the polarizing plate produced above, the peeling film 62 was peeled. After bonding the surface of the first retardation layer side of the retardation layer laminate prepared above by peeling and exposing the COP film and the surface of the pressure-sensitive adhesive layer 61 exposed by peeling the release film 62, the second retardation layer side By peeling the COP film of the second protective layer / polarizing layer / first protective layer / adhesive layer 61 / first retardation layer / adhesive layer / optical laminate having a layer structure of the second retardation layer (circularly polarizing plate) got Moreover, in manufacture of an optical laminated body, when bonding each layer, corona treatment is given to the bonding surface, and the long side and short side of each layer are made to match at the time of bonding, and the absorption axis direction of a polarizing layer is a 1st It was made to be 45 degrees with respect to the slow-axis direction of the retardation layer.

As for the obtained optical laminated body, the glue absence part is formed in the whole periphery. The distance L1 was measured in the said procedure about the absence of a glue in the arbitrary position of each side of the optical laminated body, and the average value was computed. Moreover, the high temperature test of the obtained optical laminated body was done, the change of the hue of reflected light was measured, and the visibility which confirms the state of color nonuniformity was evaluated. These results are shown in Table 1. Moreover, from the measurement result of the distance L1 in each side, it was confirmed that the distance L1 of a glue absence part in the whole perimeter of the optical laminated body of a present Example is about the same as the value shown in Table 1.

[Example 2 and Comparative Example 1]

As a cutting blade used to cut the pressure-sensitive adhesive layer 60 with a release film (FIG. 3(a)), a cutting blade (single blade) having an angle θ of the tip portion 65a smaller than that used in Example 1 was used. Except having obtained the rectangular adhesive layer 60 with a peeling film, it carried out similarly to Example 1, and obtained the optical laminated body. As for the obtained optical laminated body, the glue absence part is formed in the whole periphery. The distance L1 was measured in the said procedure about the absence of a glue in the arbitrary position of each side of the optical laminated body, and the average value was computed. Moreover, the high temperature test of the obtained optical laminated body was done, the change of the hue of reflected light was measured, and the visibility which confirms the state of color nonuniformity was evaluated. These results are shown in Table 1. Moreover, from the measurement result of the distance L1 in each side, it was confirmed that the distance L1 of a glue absence part in the whole perimeter of the optical laminated body of a present Example is about the same as the value shown in Table 1.

5: no glue, 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 protective layer, 43: second protective layer, 60: pressure-sensitive adhesive layer with release film, 61: pressure-sensitive adhesive layer, 62: release film, 65: cutting blade, 65a: blade tip portion.

Claims (10)

An optical laminate having a polarizing layer, an adhesive layer, and a first retardation layer in this order, comprising:
The optical laminate has a glue-free portion at an end thereof in the plane direction,
In the section through which the polarizing layer and the pressure-sensitive adhesive layer overlap in the lamination direction, the position of the innermost end at the end of the pressure-sensitive adhesive layer is the position of the outermost end at the end of the polarizing layer. An optical laminate formed to be located 3 μm or more inside from the The optical laminate according to claim 1, wherein in the polarizing layer, a dichroic dye is adsorbed and oriented on a polyvinyl alcohol-based resin film. The optical laminate according to claim 1 or 2, wherein the optical laminate has a quadrangle or a quadrangle having a notch on at least one side, and the glue-free portion is formed on at least one side of the quadrangle. The method according to claim 3, wherein the quadrangle 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 said glue absence part is formed in at least one of the said pair of long sides, and at least one of the said pair of short sides, The optical laminated body. The method according to claim 3, wherein the quadrangle 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 said glue absence part is formed in at least one of the said pair of short sides, The optical laminated body. The method according to claim 3, wherein the quadrangle 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 said glue absence part is formed in at least one of the said pair of long sides, The optical laminated body. The optical laminate according to any one of claims 1 to 6, wherein the polarizing layer has a protective layer on one or both surfaces thereof. The optical laminate according to any one of claims 1 to 7, further comprising a second retardation layer on a side opposite to the pressure-sensitive adhesive layer of the first retardation layer. The optical laminate according to claim 8, wherein the second retardation layer is formed on the first retardation layer through an adhesive layer. The optical laminate according to any one of claims 1 to 9, which is a circularly polarizing plate.

Images