Optical laminate

Abstract

The present invention aims to provide an optical laminate capable of suppressing the deterioration of the color uniformity of reflected light within a plane even under high-temperature environments. The optical laminate has a polarizing layer, an adhesive layer, and a first phase difference layer in that order. The optical laminate has a glue-free portion at its end in the plane direction, and the glue-free portion is formed such that, in a cross-section passing through the portion where the polarizing layer and the adhesive layer overlap in the lamination direction, the innermost position at the end of the adhesive layer is located at least 3 μm inward from the outermost position at the end of the polarizing layer.

Description

Technology Field

[0001] The present invention relates to an optical laminate. Background Technology

[0002] Polarizing layers and phase difference layers are widely used as optical components for organic EL display devices or liquid crystal display devices using organic light-emitting diodes (OLEDs). For example, Patent Document 1 describes the use of a composite polarizing plate, in which a polarizer and a phase difference film coated with a liquid crystal compound are laminated, in a liquid crystal display device.

[0003] Patent Document 1 describes that by eliminating irregularities present on the outer edge surface (cut surface) when a composite polarizer is cut by chip cutting, etc., problems such as peeling or lifting of the phase difference film can be suppressed even under humid heat conditions. Prior art literature

[0004] Patent Document 1: Japanese Patent Publication No. 2008-9237 The problem to be solved

[0005] It was discovered that when a composite polarizer having a laminated polarizing layer and a phase difference film is exposed to a high-temperature environment, the color of the reflected light at the ends of the composite polarizer changes, and the uniformity of the color of the reflected light within the plane deteriorates.

[0006] The present invention aims to provide an optical laminate capable of suppressing the deterioration of the color uniformity of reflected light within a plane even under high-temperature environments. means of solving the problem

[0007] The present invention provides the following optical laminate.

[0008] [1] An optical laminate having a polarizing layer, an adhesive layer, and a first phase difference layer in this order, wherein the optical laminate has a portion without adhesive at an end in the plane direction, and

[0009] An optical laminate in which the above-mentioned adhesive-deficient portion is formed such that, in a cross-section passing through a portion where the polarizing layer and the adhesive layer overlap in the stacking direction, the innermost position at the end of the adhesive layer is located at least 3 μm inward from the outermost position at the end of the polarizing layer.

[0010] [2] The above polarizing layer is an optical laminate described in [1] in which a dichromatic pigment is adsorbed and oriented on a polyvinyl alcohol-based resin film.

[0011] [3] The optical laminate is a square, or a square having a cutout on at least one side, and

[0012] The above-mentioned pool missing portion is an optical laminate described in [1] or [2] formed on at least one side of the above-mentioned rectangle.

[0013] [4] The above quadrilateral has a pair of long sides and a pair of short sides,

[0014] The direction of the absorption axis of the polarization layer forms an angle of 45°±10° with respect to the longer side, and

[0015] The above-mentioned missing portion is an optical laminate described in [3] formed on at least one of the pair of long sides and at least one of the pair of short sides.

[0016] [5] The above rectangle has a pair of long sides and a pair of short sides,

[0017] The direction of the absorption axis of the polarization layer forms an angle of 0°±10° with respect to the longer side, and

[0018] The above-mentioned missing portion is an optical laminate described in [3] formed on at least one side of the pair of short sides.

[0019] [6] The above quadrilateral has a pair of long sides and a pair of short sides,

[0020] The absorption axis direction of the polarization layer forms an angle of 0°±10° with respect to the shorter side, and

[0021] The above-mentioned missing portion is an optical laminate described in [3] formed on at least one side of the pair of long sides.

[0022] [7] An optical laminate described in any one of [1] to [6] having a protective layer on one or both sides of the polarizing layer.

[0023] [8] An optical laminate described in any one of [1] to [7] having a second phase difference layer on the opposite side of the adhesive layer of the first phase difference layer.

[0024] [9] The optical laminate described in [8], wherein the second phase difference layer is formed on the first phase difference layer through an adhesive layer.

[0025]

[10] An optical laminate described in any one of [1] to [9] which is a circular polarizer. Effects of the invention

[0026] According to the present invention, an optical laminate can be provided that suppresses the deterioration of the color uniformity of reflected light within a plane even under high temperature environments. Brief explanation of the drawing

[0027] FIG. 1 is a cross-sectional view schematically illustrating an example of an optical laminate of the present invention. FIG. 2 is a cross-sectional view schematically illustrating another example of an optical laminate of the present invention. Figures 3 (a) and (b) are schematic diagrams for explaining the method of manufacturing the adhesive layer in the example. Specific details for implementing the invention

[0028] Hereinafter, preferred embodiments of the optical laminate of the present invention will be described with reference to the drawings. Furthermore, the scope of the present invention is not limited to the embodiments described herein and can be modified in various ways without compromising the spirit of the invention.

[0029] FIG. 1 is a cross-sectional view schematically illustrating an example of an optical laminate of the present embodiment. In the drawing, W indicates 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 phase difference layer (21) in that 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 that order, and in the optical laminate (11), an adhesive layer (31) is formed on the side of the first protective layer (42).

[0030] The polarizing layer (41) may be a polyvinyl alcohol-based resin film (hereinafter referred to as a "PVA-based resin film") in which a dichromatic pigment such as iodine is adsorbed and oriented, and the PVA-based resin film is typically a stretched polyvinyl alcohol-based resin film. The polarizing layer (41) may be a layer in which a dichromatic pigment is oriented within a cured liquid crystal compound. The first protective layer (42) and the second protective layer (43) are layers for protecting the polarizing layer (41). The first phase difference layer (21) may be a phase difference 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 phase difference layer (21) is a liquid crystal layer, the optical laminate (11) may have an orientation layer for oriented the liquid crystal compound forming the first phase difference layer (21) on the opposite side from the adhesive layer (31) of the first phase difference layer (21).

[0031] The optical laminate (11) has a glue-free portion (5) at its end in the plane direction (W). As shown in FIG. 1, the glue-free portion (5) is formed such that, in a cross-section where the polarizing layer (41) and the adhesive layer (31) overlap in a lamination direction orthogonal to the plane direction (W), the innermost position at the end of the adhesive layer (31) is located inward by a distance L1 from the outermost position at the end of the polarizing layer (41). In this specification, the innermost position at the end of the adhesive layer (31) refers to the innermost position in the plane direction (W) among the ends of the adhesive layer (31), and the outermost position at the end of the polarizing layer (41) refers to the outermost position in the plane direction (W) among the ends of the polarizing layer (41).

[0032] The distance L1 of the grass-deficient part (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, the distance L1 is typically 120 μm or less, may be 100 μm or less, 75 μm or less, 50 μm or less, or 25 μm or less.

[0033] The polarizing plate (40) included in the optical laminate (11) has a polarizing layer (41). The polarizing layer (41) may shrink under high temperature conditions. Therefore, when the optical laminate (11) is exposed to a high temperature condition, it is believed that the shrinkage stress of the polarizing layer (41) is concentrated at the end of the first phase difference layer (21) laminated to the polarizing plate (40) through the adhesive layer (31) due to the shrinkage of the polarizing layer (41) (polarizing plate (40)). When the said shrinkage stress is concentrated at the end of the first phase difference layer (21), it is presumed that due to the influence of the photoelasticity of the first phase difference layer (21), the difference in color between the reflected light at the end of the optical laminate (11) and the reflected light at other parts other than the end increases, and the uniformity of the color of the reflected light within the plane of the optical laminate (11) deteriorates. In this embodiment, the distance L1 from the pool-deficient portion (5) of the optical laminate (11) is set to 3 μm or more as described above. By doing so, it becomes easier to disperse the shrinkage stress of the polarization layer (41) when the optical laminate (11) is exposed to a high-temperature environment, thereby reducing the shrinkage stress applied to the end of the first phase difference layer (21). As a result, because 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 other than the end can be reduced due to the influence of the photoelasticity of the first phase difference layer (21), it is thought that the uniformity of the color of the reflected light within the plane of the optical laminate (11) can be suppressed.

[0034] In addition, if the distance L1 of the glue-deficient portion (5) in the optical laminate (11) is excessively large, the bonding area between the polarizer (40) and the first phase difference layer (21) becomes smaller, so it is easy for the end to peel off or for defects such as bubbles to occur during the high-temperature durability test.

[0035] The effect of shrinkage of the polarization layer (41) under a high-temperature environment is more likely to be noticeable when the polarization layer (41) is a polarization layer in which a dichromatic pigment is adsorbed and oriented on a PVA-based resin film, rather than when the polarization layer (41) is a layer in which a dichromatic pigment is oriented within a cured liquid crystal compound, particularly when the polarization layer is formed by adsorbing a dichromatic pigment onto a PVA-based resin film by dyeing and then stretching. Therefore, when using a polarization layer (41) in which a dichromatic pigment is adsorbed and oriented on a PVA-based resin film, the deterioration of the uniformity of the color of the reflected light within the plane of the optical laminate (11) can be more appropriately suppressed by making the distance L1 from the glue-deficient portion (5) 3 μm or more.

[0036] The distance L1 of the adhesive-deficient portion (5) can be calculated based on the innermost position at the end of the adhesive layer (31) and the outermost position at the end of the polarizing layer (41), which are determined based on the profile of the cross-section of the optical laminate (11) using a laser microscope. If the outer shape of the optical laminate (11) has a straight side and the adhesive-deficient portion (5) is formed on said side, the cross-section of the optical laminate (11) is the cross-section obtained by cutting along a direction perpendicular to said side at the position where the adhesive-deficient portion (5) is formed on said side. In addition, if the outer shape of the optical laminate (11) has a curved portion and a glue-deficient portion (5) is formed in the curved portion, the cross-section of the optical laminate (11) is the cross-section obtained by cutting along a direction perpendicular to the tangent line passing through the position (P) of the tangent line in the plane direction of the optical laminate (11) at the position (P) where the glue-deficient portion (5) is formed.

[0037] The shape of the adhesive-free portion (5) in the optical laminate (11) is not particularly limited, and the end of the adhesive layer (31) may have a tapered shape as shown in FIG. 1, may be parallel to the lamination direction orthogonal to the plane direction (W), or may be formed in a sawtooth shape, an uneven shape, a curved shape, etc. As shown in FIG. 1, the position of the end of the surface of the adhesive layer (31) on the polarizing plate (40) side is inward in the plane direction compared to the position of the end of the surface of the adhesive layer (31) on the first phase difference layer (21) side, and the shape may be tapered, or conversely, the position of the end of the surface of the polarizing plate (40) side is outward in the plane direction compared to the position of the end of the surface of the adhesive layer (31) on the first phase difference layer (21) side, and the shape may be tapered. In the case of the latter tapered shape, the shrinkage stress of the polarization layer (41) under high temperature conditions is easily dispersed, so it is thought that it is easy to suppress the deterioration of the uniformity of the color of the reflected light within the plane of the optical laminate (11).

[0038] The external shape of the optical laminate (11) may be a rectangle in the plane direction (in a planar state), or a rectangle having a cutout on at least one side. In this specification, a rectangle refers to a rectangular shape or a square, and includes a shape in which at least one of the four corners of the rectangle is rounded.

[0039] In addition, the boundary of two sides that are continuous through the rounded portion is set at a position that bisects the contour length of the rounded portion. The contour length of the rounded portion is the length between the ends of the straight portions of each of the two sides that are continuous through the rounded portion, which are located on the side of the rounded portion. As for the cutout, a concave shape that becomes concave toward the opposing side may be used, and the concave shape may be U-shaped or V-shaped.

[0040] The cutout may be formed on one side of the rectangle or on two or more sides. The cutout may be formed in an area where at least one of a receiver, speaker, camera lens, LED lamp, proximity sensor, light sensor, fingerprint authentication sensor, operation button, etc., is installed, for example, in a smartphone.

[0041] When the optical laminate (11) is rectangular, the glue-deprived portion (5) is preferably formed on at least one side of the rectangle, may be formed on two or more sides, or may be formed on all four sides. Additionally, the glue-deprived portion (5) may be formed continuously or discontinuously along the entire length of the side, or may be formed on a part of the side. Additionally, the glue-deprived portion (5) may be formed on at least a part of the cut section, or may be formed on the entire cut section.

[0042] The optical laminate (11) may have a hole portion that penetrates the entire optical laminate (11) in the stacking direction. The hole portion may be circular, elliptical, or a polygon such as a square or a hexagon, and at least one of the angles of the polygon may be rounded. A glue-free portion (5) may be formed on the periphery portion of the hole portion. The glue-free portion formed on the hole portion may be formed on at least a part of the periphery portion of the hole portion, or may be formed on the entire periphery portion of the hole portion. The hole portion may be formed in an area where a camera lens, etc., is installed, for example, in a smartphone.

[0043] When the optical laminate (11) has a square shape, and this square is 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) forms an angle of 45°±10° with respect to the long side, it is preferable that the glue-free portion (5) be formed on at least one side of the pair of long sides and on at least one side of the pair of short sides. In this specification, the angle refers to an acute angle among the angles formed by the absorption axis direction and the long side. The glue-free portion (5) may be formed on both sides of the pair of long sides or on both sides of the pair of short sides. Since the polarizing layer (41) of the optical laminate (11) is prone to shrinking in the absorption axis direction when exposed to a high-temperature environment, the shrinkage stress of the polarizing layer (41) is prone to concentrating on the sides located at both ends of the absorption axis direction. Therefore, in an optical laminate (11) in which the absorption axis direction and the long side are in a relationship of 45°±10°, it is thought that the shrinkage stress of the polarization layer (41) is likely to be concentrated on both the long side and the short side, and the color of the reflected light of the first phase difference layer (21) is likely to change. As described above, by forming a glue-deficient portion (5) on at least one of the pair of long sides and at least one of the pair of short sides, the shrinkage stress can be dispersed in the portion where the shrinkage stress of the polarization layer (41) is likely to be concentrated when the optical laminate (11) is exposed to a high-temperature environment. By doing so, it is thought that the uniformity of the color of the reflected light within the plane 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 polarization layer (41) with respect to the long side may be 45°±5°, 45°±2°, or 45°.

[0044] When the optical laminate (11) has a square shape, and this square is a rectangle having a pair of long sides and a pair of short sides, and the absorption axis direction of the polarizing layer (41) forms an angle of 0°±10° with respect to the long side, it is preferable that the glue-free portion (5) be formed on at least one side of the pair of short sides. In this specification, the angle refers to the acute angle among the angles formed by the absorption axis direction and the long side. The glue-free portion (5) may be formed on both sides of the pair of short sides. In the optical laminate (11) where the absorption axis direction and the long side are in a relationship of 0°±10°, it is thought that, for the above reason, the shrinkage stress of the polarizing layer (41) is likely to concentrate on the short side, and the color of the reflected light of the first phase difference layer (21) is likely to change. Therefore, it is believed that by forming a glue-deficient portion (5) on at least one side of a pair of short sides, the uniformity of the color of the reflected light within the plane 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 polarization layer (41) with respect to the long side may be 0°±5°, 0°±2°, or 0°.

[0045] When the optical laminate (11) has a square shape, and this square is a rectangle having a pair of long sides and a pair of short sides, and the absorption axis direction of the polarizing layer (41) forms an angle of 0°±10° with respect to the short side, it is preferable that the glue-free portion (5) be formed on at least one side of the pair of long sides. In this specification, the angle refers to the acute angle among the angles formed by the absorption axis direction and the short side. The glue-free portion (5) may be formed on both sides of the pair of long sides. In the optical laminate (11) where the absorption axis direction and the short side are in a relationship of 0°±10°, it is thought that, for the above reason, the shrinkage stress of the polarizing layer (41) is likely to concentrate on the long side, and the color of the reflected light of the first phase difference layer (21) is likely to change. Therefore, it is believed that by forming a glue-deficient portion (5) on at least one side of a pair of long sides, the uniformity of the color of the reflected light within the plane 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 polarization layer (41) with respect to the short side may be 0°±5°, 0°±2°, or 0°.

[0046] In the optical laminate (11) illustrated in FIG. 1, the first phase difference layer (21) may be an A plate or a C plate. In addition, in the optical laminate (11) illustrated in FIG. 1, the first phase difference layer (21) can be made into a 1 / 4 wavelength plate to make it a circularly polarized plate.

[0047] The optical laminate (11) illustrated in FIG. 1 can be manufactured by, for example, preparing a polarizing plate (40) and a first phase difference layer (21), applying or transferring an adhesive to at least one of the first protective layer (42) side of the polarizing plate (40) and the first phase difference layer (21), and bonding the polarizing plate (40) and the first phase difference layer (21) through a layer of adhesive. In the case where the first phase difference layer (21) is a liquid crystal layer, the first phase difference layer (21) of the first phase difference layer attached to the substrate layer, which is formed peelably on the first substrate layer, and the polarizing plate (40) can be laminated through an adhesive, and then the first substrate layer may be peeled off.

[0048] The method of forming the adhesive-deficient portion (5) in the optical laminate (11) is not particularly limited, but, for example, it can be formed by adjusting the application range or transfer position of the adhesive layer to form the adhesive layer (31). When the adhesive layer (31) is formed by transfer, a portion that becomes the adhesive-deficient portion (5) may be formed on the adhesive layer formed on a release film, etc., prepared for transfer, and the adhesive layer with the portion that becomes the adhesive-deficient portion (5) may be transferred onto the polarizing plate (40) or the first phase difference layer (21).

[0049] In order to form a portion that becomes a glue-deficient portion (5) in an adhesive layer formed on a release film, etc., for example as shown in FIG. 3 (a) to (b), a release film-attached adhesive layer (60) in which an adhesive layer (61) is formed on a release film (62) is prepared, and the release film-attached adhesive layer (60) can be formed by cutting the release film-attached adhesive layer (60) from the side of the adhesive layer (61) with a cutting blade (65) of a single blade. In the process of cutting the release film-attached adhesive layer (60) in this way, the adhesive layer (61) is pressed into a tapered shape by the side of the cutting blade (65) of the single blade on which the blade is formed, thereby forming an adhesive layer with a tapered end.

[0050] (Variation Example)

[0051] The optical film of the present embodiment may be modified as shown in the variations below, and may be implemented by combining each structure and each process of the embodiment and its variations.

[0052] (Variation Example 1)

[0053] In the above embodiment, an optical laminate (11) having a polarizing plate (40) having a first protective layer (42) and a second protective layer (43) on both sides of a polarizing layer (41) has been described, but it is not limited thereto. The polarizing plate may include the polarizing layer (41) and either the first protective layer (42) or the second protective layer (43). Additionally, the first protective layer (42) and the second protective layer (43) may not be included in the optical laminate (11).

[0054] (Variation Example 2)

[0055] When the optical laminate (11) shown in FIG. 1 is a circular polarizer, this circular polarizer can be used, for example, for anti-reflection of an organic electroluminescence (organic EL) display device. In this case, the optical laminate (11) is bonded to the viewing 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 adhesive layer (31) of the first phase difference layer (21).

[0056] (Variation Example 3)

[0057] In the above embodiment, an optical laminate (11) including a first phase difference layer (21) has been described, but it is not limited thereto and may be an optical laminate as shown in FIG. 2, for example. FIG. 2 is a cross-sectional view schematically illustrating another example of an optical laminate of the present embodiment. Hereinafter, the same reference numerals are used for components identical to those described above, and their descriptions are omitted. The optical laminate (12) shown in FIG. 2 has a polarizing plate (40), an adhesive layer (31), a first phase difference layer (21), an adhesive layer (35), and a second phase difference layer (22) in that order. The adhesive layer (35) may be an adhesive layer formed using an adhesive or an adhesive layer formed using an adhesive. The second phase difference layer (22) may be a phase difference film or a liquid crystal layer containing a liquid crystal compound such as a polymerizable liquid crystal compound. When the second phase difference layer (22) is a liquid crystal layer, the optical laminate (12) may have an orientation layer on the opposite side of the adhesive layer (35) of the second phase difference layer (22) for oriented the liquid crystal compound forming the second phase difference layer (22).

[0058] In the optical laminate (12), the first phase difference layer (21) can be made into a 1 / 2 wavelength plate and the second phase difference layer (22) into a 1 / 4 wavelength plate; the first phase difference layer (21) into a 1 / 4 wavelength plate with inverse wavelength dispersion and the second phase difference layer (22) into a positive C plate; the first phase difference layer (21) into a positive C plate and the second phase difference layer (22) into a 1 / 4 wavelength plate with inverse wavelength dispersion can be made into a circular polarizing plate. When the combination of the first phase difference layer (21) and the second phase difference layer (22) is a 1 / 2 wavelength plate and a 1 / 4 wavelength plate, the ground axis direction of the 1 / 2 wavelength plate can be 70° to 80° with respect to the absorption axis direction of the polarizing layer (41), and the ground axis direction of the 1 / 4 wavelength plate can be 10° to 20°. In addition, when the combination of the first phase difference layer (21) and the second phase difference layer (22) is a quarter-wave plate and a positive C plate with inverse wavelength dispersion, the ground axis direction of the quarter-wave plate can be 40° to 50° with respect to the absorption axis direction of the polarization layer (41). When the optical laminate (12), which is a circular polarizer, is used for anti-reflection of an organic EL display device, the optical laminate (12) shown in FIG. 2 may have an adhesive layer for an optical display element on the opposite side from the adhesive layer (35) of the second phase difference layer (22).

[0059] The optical laminate (12) illustrated in FIG. 2 can be formed by preparing, for example, a phase difference layer laminate in which a first phase difference layer (21) and a second phase difference layer (22) are laminated through an adhesive layer (35) and a polarizing plate (40), applying or transferring an adhesive to at least one of the first protective layer (42) side of the polarizing plate (40) and the first phase difference layer (21) side of the phase difference layer laminate, and bonding the polarizing plate (40) and the phase difference layer laminate through the adhesive. When both the first phase difference layer (21) and the second phase difference layer (22) are liquid crystal layers, the optical laminate (12) can be obtained, for example, as follows. First, a first phase difference layer (21) of a first phase difference layer attached to a substrate layer, in which a first phase difference layer (21) is formed peelably on a first substrate layer, and a second phase difference layer (22) of a second phase difference layer attached to a substrate layer, in which a second phase difference layer (22) is formed peelably on a second substrate layer, are laminated through an adhesive layer to obtain a phase difference layer laminate. Next, the first substrate layer is peeled off from the phase difference layer laminate, and the first phase difference layer (21) side and the first protective layer (42) side of the polarizing plate (40) are laminated through an adhesive, and then the second substrate layer is peeled off to obtain an optical laminate (12) as shown in FIG. 2.

[0060] Hereinafter, each common aspect of the above embodiments and variations thereof will be described in detail.

[0061] (Polarization layer)

[0062] The polarizing layer (41) may be a dichromatic pigment such as iodine adsorbed and oriented on a PVA-based resin film, or a dichromatic pigment oriented in a layer of a liquid crystal compound that has been cured.

[0063] A PVA-based resin film is a film formed using a polyvinyl alcohol-based resin. A polyvinyl alcohol-based resin refers to a resin containing 50 mass% or more of constituent units derived from vinyl alcohol. As a polyvinyl alcohol-based resin, a polyvinyl acetate-based resin obtained by saponification can be used. The degree of saponification of the polyvinyl acetate-based resin can be determined in accordance with JIS K 6727 (1994) and, for example, can be in the range of 80.0 to 100.0 mol%.

[0064] Examples of polyvinyl acetate-based resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other monomers copolymerizable thereto. Examples of other monomers copolymerizable to vinyl acetate include, for instance, unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth)acrylamides having ammonium groups. In this specification, "(meth)acryl" refers to at least one selected from the group consisting of acrylic and methacryl. The same applies to other terms prefixed with "(meth)acryl."

[0065] An example of a PVA-based resin film may be an unoriented film formed by producing a polyvinyl alcohol-based resin, or a stretched film formed by stretching the unoriented film. When the PVA-based resin film is a stretched film, it is preferable that it be a stretched film that is longitudinally uniaxially stretched, and it is preferable that it be a stretched film that is dry-stretched. When the PVA-based resin film is a stretched film, the stretching ratio is typically 1.1 to 8 times.

[0066] Examples of dichromatic pigments adsorbed and oriented on a 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, 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. Dichromatic pigments may be used alone or in combination of two or more types.

[0067] Among the layers cured from a liquid crystal compound, a polarizing layer in which a dichromatic pigment is oriented can be, for example, a cured layer formed by oriented a dichromatic pigment within a polymerizable liquid crystal compound and polymerizing the polymerizable liquid crystal compound. Such a polarizing layer can be formed by applying a composition for forming a polarizing layer containing a liquid crystal compound and a dichromatic pigment onto a substrate film, and then polymerizing and curing the liquid crystal compound while maintaining the liquid crystal state. The polarizing layer obtained in this way is laminated onto the substrate film, and the substrate film may be used as a protective layer for the polarizing layer. Alternatively, the substrate film may be peeled off after the substrate film-attached polarizing layer, which allows the substrate film to be peeled off from the polarizing layer, is laminated onto the first phase difference layer through an adhesive layer (31).

[0068] Liquid crystal compounds only need to have properties that exhibit a liquid crystal state, and it is particularly desirable to have a higher-order orientation state, such as a smectic phase, as this can exhibit high polarization performance.

[0069] In addition, it is desirable for the liquid crystal compound to have a polymerizable functional group. The dichromatic dye is a dye that exhibits dichroism by being oriented together with the liquid crystal compound, and the dichromatic dye itself may have liquid crystal properties or may have a polymerizable functional group. Any compound in the composition for forming a polarizing layer containing the liquid crystal compound has a polymerizable functional group.

[0070] Examples of dichromatic pigments that can be used in a polarizing layer using a liquid crystal compound include acridine pigment, oxazine pigment, cyanine pigment, naphthalene pigment, azo pigment, anthraquinone pigment, etc., but among these, azo pigment is preferred. Examples of azo pigments include monoazo pigment, bis-azo pigment, tris-azo pigment, tetrakis-azo pigment, stilbene-azo pigment, etc., and bis-azo pigment and tris-azo pigment are more preferred. The dichromatic pigment may be used alone or two or more types may be used in combination.

[0071] The composition for forming a polarizing layer may include 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 crosslinking agent, a silane coupling agent, etc. Regarding the polymerizable liquid crystal compound, dichromatic dye, solvent, polymerization initiator, photosensitizer, polymerization inhibitor, etc. included in the composition for forming a polarizing layer, known materials may be used. In addition, the polymerizable liquid crystal compound may be the same as the compound exemplified as the polymerizable liquid crystal compound used to obtain the first phase difference layer and the second phase difference layer described below.

[0072] The thickness of the polarization layer (41) is typically 2 to 40 μm, and from the perspective of thinning the polarization layer, it is preferable that it be 30 μm or less, and more preferable that it be 20 μm or less. A polarization layer in which a dichromatic pigment is oriented among the layers cured from a liquid crystal compound can be formed with a smaller thickness compared to a polarization layer in which a dichromatic pigment such as iodine is adsorbed and oriented on a PVA-based resin film. The thickness of the polarization layer using a liquid crystal compound may be, for example, 0.5 to 5 μm, preferably 1 to 4 μm.

[0073] In addition, the visual sensitivity correction single transmittance Ty of the polarization layer (41) is preferably 40 to 47%, and more preferably 41 to 45%, considering the balance with the visual sensitivity correction polarization degree Py. The visual sensitivity correction polarization degree Py is preferably 99.9% or higher, and more preferably 99.95% or higher. Ty and Py can be obtained by performing visual sensitivity correction using the 2-degree field of view (C light source) of JIS Z 8701 on the transmittance and polarization degree obtained using an absorbance spectrometer with an integrating sphere.

[0074] (Polarizing plate)

[0075] A polarizing plate is formed by laminating a protective layer (a first protective layer, a second protective layer) on one or both sides of a polarizing layer through a known adhesive layer or adhesive layer. The thickness of the polarizing plate may 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.

[0076] As a protective layer, for example, a film formed from a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, and stretchability is used. Specific examples of such thermoplastic resins include cellulose resins such as triacetylcellulose; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; polyethersulfone resins; polysulfone resins; polycarbonate resins; polyamide resins such as nylon or aromatic polyamides; polyimide resins; polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers; cyclic polyolefin resins having cyclo-based and norbornene structures (also called norbornene-based resins); (meth)acrylic resins; polyarylate resins; polystyrene resins; polyvinyl alcohol resins and mixtures thereof. When protective layers are laminated on both sides of a polarizing layer, the resin compositions of the two protective layers may be the same or different. A film formed of a thermoplastic resin may be surface-treated (e.g., corona treatment) to improve adhesion with a polarizing layer, and may have a thin layer formed thereon, such as a primer layer (also called an undercoating layer).

[0077] The protective layer may be, for example, a stretched thermoplastic resin or an unstretched one (hereinafter referred to as "unstretched resin"). Examples of stretching treatments include uniaxial stretching or biaxial stretching.

[0078] The thickness of the protective layer is preferably 3 μm or more, and more preferably 5 μm or more. Additionally, the thickness of the protective layer is preferably 50 μm or less, and more preferably 35 μm or less. Furthermore, the aforementioned upper and lower limits can be combined arbitrarily. As the thickness of the polarizer decreases, the rigidity decreases, and it becomes more susceptible to the shrinkage stress of the polarizing layer. Therefore, in an optical laminate having a protective layer with a thin thickness, the polarizer is susceptible to the shrinkage stress of the polarizing layer at its ends, and there is a tendency for the uniformity of the color of the reflected light within the plane to deteriorate under high-temperature environments. For this reason, in such an optical laminate, it is believed that by making the distance L1 of the glue-free portion 3 μm or more as described above, the deterioration of the uniformity of the color of the reflected light within the plane can be effectively suppressed even under high-temperature environments.

[0079] The surface opposite to the polarization layer of the protective layer may have a surface treatment layer, such as a hardcoat layer, an anti-reflective layer, an anti-sticking layer, an anti-glare layer, a diffusion layer, etc. The surface treatment layer may be a separate layer laminated on the protective layer, or it may be formed by surface treatment on the surface of the protective layer.

[0080] (1st phase difference layer and 2nd phase difference layer)

[0081] The first phase difference layer and the second phase difference layer (hereinafter, both may be collectively referred to as the "phase difference layer") may be a phase difference film or a liquid crystal layer. The phase difference film may be one that exhibits optical anisotropy, and examples include a stretched film obtained by stretching a film formed of polyvinyl alcohol, polycarbonate, polyester, polyarylate, polyimide, polyolefin, polycycloolefin, polystyrene, polysulfone, polyethersulfone, polyvinylidene fluoride / polymethyl methacrylate, acetylcellulose, ethylene-vinyl acetate copolymer saponified product, polyvinyl chloride, etc., by about 1.01 to 6 times.

[0082] When the phase difference layer is a liquid crystal layer, the type of liquid crystal compound forming the liquid crystal layer is not particularly limited, and rod-shaped liquid crystal compounds, disc-shaped liquid crystal compounds, and mixtures thereof may be used. The liquid crystal layer may be formed by applying a composition for forming a liquid crystal layer, comprising a liquid crystal compound, a solvent, and various additives as needed, onto an alignment layer to form a film, and then solidifying (curing) this film to form a liquid crystal layer, which is a cured layer of the liquid crystal compound. Alternatively, the liquid crystal layer may be formed by applying a composition for forming a liquid crystal layer onto a substrate layer to form a film, and then stretching this film together with the substrate layer. In addition to the liquid crystal compound and solvent mentioned above, the composition for forming a liquid crystal layer may include a polymerization initiator, a reactive additive, a leveling agent, a polymerization inhibitor, etc. Known liquid crystal compounds, solvents, polymerization initiators, reactive additives, leveling agents, polymerization inhibitors, etc., may be appropriately used.

[0083] The substrate layer (first substrate layer, second substrate 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, and stretchability is used. Specifically, polyolefin resins such as polyethylene and polypropylene; cyclic polyolefin resins such as norbornene-based polymers; polyester resins such as polyethylene terephthalate and polyethylene naphthalate; (meth)acrylic acid resins such as (meth)acrylic acid and poly(meth)acrylate methyl; cellulose ester resins such as triacetylcellulose, diacetylcellulose, and cellulose acetate propionate; vinyl alcohol resins such as polyvinyl alcohol and polyvinyl acetate; polycarbonate resins; polystyrene resins; polyarylate resins; polysulfone resins; polyethersulfone resins; polyamide resins; and polyimide resins. Examples include polyetherketone-based resins; polyphenylene sulfide-based resins; polyphenylene oxide-based resins, mixtures thereof, copolymers, etc. Among these resins, it is preferable to use any one of cyclic polyolefin-based resins, polyester-based resins, cellulose ester-based resins, and (meth)acrylic acid-based resins, or a mixture thereof.

[0084] The substrate layer may be a single layer or may have a multilayer structure of two or more layers. In the case of a multilayer structure, the types of resins forming each layer may be the same or different. The thickness of the substrate layer is not particularly limited, but generally, for the sake of workability such as strength and handling, it is preferable to be 1 to 300 μm, more preferable to be 10 to 200 μm, and even more preferable to be 30 to 120 μm.

[0085] The above-mentioned orientation layer has an orientation regulating force that aligns a liquid crystal compound, such as a polymerizable liquid crystal compound included in a liquid crystal layer formed thereon, in a desired direction. Examples of the orientation layer include an orientation polymer layer formed of an orientation polymer, a photo-orientation polymer layer formed of a photo-orientation polymer, and a groove orientation layer having an uneven pattern or a plurality of grooves on the surface of the layer. The thickness of the orientation layer is typically 10 to 500 nm, and is preferably 10 to 200 nm.

[0086] (Adhesive layer)

[0087] The adhesive layer is a layer formed using an adhesive. In this specification, the term "adhesive" refers to a material that exhibits adhesive properties by coating itself onto a substrate, such as an optical film or a liquid crystal layer, and is referred to as a so-called pressure-sensitive adhesive. As for the adhesive, any conventionally known adhesive with excellent optical transparency may be used without particular limitation, and, for example, an adhesive having a base polymer such as an acrylic, urethane, silicone, or polyvinyl ether type may be used. The thickness of the adhesive layer may be 3 μm or more, 5 μm or more, 35 μm or less, or 30 μm or less.

[0088] The adhesive layer may include additives such as a UV absorber, an antistatic agent using an ionic compound, a solvent, a crosslinking catalyst, a tackifier, a plasticizer, a softener, a dye, a pigment, and an inorganic filler. In particular, by including a UV absorber in the adhesive layer, when the first phase difference layer is a liquid crystal layer, the degradation of the liquid crystal compound contained in the liquid crystal layer due to the influence of external light, etc., can be suppressed.

[0089] (Adhesive layer)

[0090] The adhesive layer can be formed by an adhesive layer, an adhesive layer formed using an adhesive, and a combination thereof, and is typically one layer, but may have two or more layers. When the adhesive layer consists of two or more layers, each layer may be formed of the same material or may be formed of different materials. The adhesive layer can be formed using the adhesive.

[0091] As adhesives that can be used in the adhesive layer, conventionally known adhesives, such as water-based adhesives and active energy beam curing adhesives, may be used without particular limitation. Examples of water-based adhesives include aqueous solutions of polyvinyl alcohol-based resins and water-based two-component urethane-based emulsion adhesives. Active energy beam curing adhesives are adhesives that cure by irradiating with active energy beams such as ultraviolet rays, and examples include those containing a polymerizable compound and a photopolymerization initiator, those containing a photoreactive resin, and those containing a binder resin and a photoreactive crosslinking agent. Examples of the polymerizable compound include photopolymerizable monomers such as photocurable epoxy monomers, photocurable acrylic monomers, and photocurable urethane monomers, or oligomers derived from these monomers. Examples of the photopolymerization initiator include substances that generate active species, such as neutral radicals, anionic radicals, and cationic radicals, by irradiating with active energy beams such as ultraviolet rays.

[0092] Examples

[0093] The present invention will be explained more specifically below by presenting examples and comparative examples, but the present invention is not limited by these examples. In the examples and comparative examples, "%" and "parts" refer to mass % and mass parts, respectively, unless otherwise specifically stated.

[0094] [Fabrication of Polarizing Plates]

[0095] As a first protective layer, a triacetylcellulose film with a thickness of 20 μm was prepared. As a second protective layer, a norbornene-based resin film with a thickness of 29 μm was prepared, with a hardcoat layer formed on one surface. As a polarizing layer, a PVA-based resin film in which iodine, a dichromatic dye, was adsorbed and oriented was prepared. The thickness of the polarizing layer was 8 μm.

[0096] In addition, 3 parts by weight of carboxyl group modified polyvinyl alcohol [product name “KL-318” obtained from Kuraray Co., Ltd.] were dissolved in 100 parts by weight of water, and 1.5 parts by weight of a water-soluble epoxy resin, a polyamide epoxy additive [product name “Sumiresin (registered trademark) 650 (30) obtained from Taoka Chemical Industry Co., Ltd., aqueous solution with a solid content concentration of 30% by weight] was added to the aqueous solution to prepare a water-based adhesive.

[0097] Saponification treatment was applied to the first protective layer, and corona treatment was applied to the surface of the norbornene-based resin film side of the second protective layer and to both sides of the polarizing layer. The first protective layer was bonded to one side of the polarizing layer using the water-based adhesive obtained above, and the side opposite to the hardcoat layer (norbornene-based resin film side) of the second protective layer was bonded to the other side of the polarizing layer using the same water-based adhesive as above, and a drying treatment was performed to produce a polarizing plate. The obtained polarizing plate was cut into a rectangle such that the absorption axis of the polarizing layer is 45° with respect to the long side direction.

[0098] [Fabrication of the first phase difference layer]

[0099] (Preparation of a composition for forming a horizontal orientation layer)

[0100] A composition for forming a horizontal orientation layer was obtained by mixing the following components and stirring the resulting mixture at a temperature of 80°C for 1 hour.

[0101] · Photo-oriented material (Part 5) (Weight average molecular weight: 30,000) :

[0102]

[0103] · Solvent (Part 95): Cyclopentanone

[0104] (Preparation of a composition for forming a horizontally oriented liquid crystal layer)

[0105] A composition for forming a horizontally oriented liquid crystal layer was obtained by mixing the following components, adding N-methyl-2-pyrrolidone (NMP) to achieve a solid content of 13%, and stirring at 80°C for 1 hour. The following polymerizable liquid crystal compound A was synthesized by the method described in Japanese Patent Publication No. 2010-31223, and the following polymerizable liquid crystal compound B was synthesized in accordance with the method described in Japanese Patent Publication No. 2009-173893.

[0106] · Polymerizable liquid crystal compound A (90 parts) :

[0107]

[0108] · Polymerizable liquid crystal compound B (10 parts) :

[0109]

[0110] · Polymerization initiator (Part 6) :

[0111] 2-Dimethylamino-2-benzyl-1-(4-morpholinophenyl)butan-1-one (Irgacure 369, manufactured by BASF Japan Co., Ltd.)

[0112] (Fabrication of the first phase difference layer)

[0113] Corona treatment was performed on a cyclic olefin resin (COP) film (ZF-14-50, manufactured by Nippon Zeon Co., Ltd.). The composition for forming a horizontal alignment layer obtained above was applied to the corona-treated surface of the COP film using a bar coater and dried at 80°C for 1 minute. A horizontal alignment layer was obtained by exposing the coated film to polarized UV light at an axial angle of 45° using a polarized UV irradiation device ("SPOT CURE SP-9", manufactured by Ushio Electric Co., Ltd.) such that the integrated light amount at a wavelength of 313 nm was 100 mJ / cm².

[0114] Next, the composition for forming a horizontally aligned liquid crystal layer obtained above was applied to this horizontally aligned layer using a bar coater and dried at 120°C for 1 minute. A first phase difference layer, which is a horizontally aligned liquid crystal layer, was formed by irradiating the coated film with ultraviolet light using a high-pressure mercury lamp ("Unicure VB-15201BY-A", manufactured by Ushio Electric Co., Ltd.) (integrated light intensity at a wavelength of 365 nm under a nitrogen atmosphere: 500 mJ / cm²). The first phase difference layer was a quarter-wave plate exhibiting inverse wavelength dispersion.

[0115] [Fabrication of the second phase difference layer]

[0116] (Preparation of a composition for forming a vertical orientation layer)

[0117] As a composition for forming a vertical orientation layer, San-Eva SE610 (manufactured by Nissan Chemical Industry Co., Ltd.) was prepared.

[0118] (Preparation of a composition for forming a vertically oriented liquid crystal layer)

[0119] A composition for forming a vertically oriented liquid crystal layer was obtained by mixing the following components and adding cyclopentanone so that the solid content concentration becomes 13%.

[0120] · Polymerizable liquid crystal compound C (100 parts) :

[0121] Paliocolor (registered trademark) LC242 (manufactured by BASF)

[0122] · Leveling agent (0.1 part) :

[0123] F-556 (manufactured by DIC)

[0124] · Polymerization initiator (Part 3):

[0125] Yirgacure 369 (Manufactured by Chiba Specialty Chemicals)

[0126] (Fabrication of the second phase difference layer)

[0127] Corona treatment was performed on a cyclic olefin resin (COP) film (ZF-14-50, manufactured by Nippon Zeon Co., Ltd.). The composition for forming a vertical alignment layer obtained above was applied to the corona-treated surface of the COP film using a bar coater, and dried at 80°C for 1 minute to obtain a vertical alignment layer. Subsequently, the composition for forming a vertical alignment liquid crystal layer obtained above was applied to the vertical alignment layer using a bar coater, and dried at 90°C for 120 seconds. A second phase difference layer, which is a vertical alignment liquid crystal layer, was formed on this coating film by irradiating it with ultraviolet light using a high-pressure mercury lamp ("Unicure VB-15201 BY-A", manufactured by Ushio Electric Co., Ltd.) (under a nitrogen atmosphere, integrated light intensity at a wavelength of 365 nm: 500 mJ / cm²). The second phase difference layer is nx ≈ ny <nz의 관계를 만족시키는 포지티브 C 플레이트였다.

[0128] [Fabrication of Phase Difference Layer Laminate]

[0129] Corona treatment was performed on the surface opposite to the COP film of the first phase difference layer prepared above, and on the surface opposite to the COP film of the second phase difference layer prepared above. After bonding these corona-treated surfaces (the surface of the first phase difference layer and the surface of the second phase difference layer) together using a UV-curing adhesive, the UV-curing adhesive was cured by irradiating with ultraviolet light to obtain a phase difference layer laminate in which the first phase difference layer and the second phase difference layer are laminated through the adhesive layer. The obtained phase difference layer laminate was cut into a rectangle such that the ground axis of the first phase difference layer (1 / 4 wavelength plate) is parallel to the long side direction.

[0130] [Measurement of distance L1 of the grass deficiency area]

[0131] An optical laminate with an adhesive layer attached was obtained by laminating an acrylic adhesive layer with a thickness of 20 μm formed on a release film onto the second phase difference layer side of the optical laminate obtained in each example and each comparative example. With respect to this optical laminate with an adhesive layer attached, a side where the adhesive is missing was identified, and a profile was measured using a laser microscope regarding the cross-section when the optical laminate with an adhesive layer attached was cut along a direction perpendicular to said side at the location where the adhesive is missing. Based on the measured profile, the distance L1 between the innermost position at the end of the adhesive layer (61) and the outermost position at the end of the polarization layer was measured.

[0132] [High Temperature Test]

[0133] An acrylic adhesive layer with a thickness of 20 μm was laminated on the second phase difference layer side of the optical laminate obtained in each example and each comparative example, and this acrylic adhesive layer was bonded to a glass plate to be used as an evaluation sample.

[0134] A high-temperature test was performed on the obtained evaluation sample by placing it in an oven at a temperature of 80°C for 200 hours. After the high-temperature test, the evaluation sample was placed on a reflector (MIRO5 5011GP manufactured by Alanod, Inc.) with the glass plate facing downward, and the color of the reflected light was measured using a spectrophotometer (CM2600d, Konica Minolta Corporation). The measurement was performed by attaching a mask with an aperture diameter φ of 1.5 mm when light enters the integrating sphere from the evaluation sample, and the average value of the difference between the color of the reflected light (a*b*) at the center of the four end edges of the evaluation sample and the color of the reflected light (a*b*) at the center of the evaluation sample (the intersection of the diagonals of the rectangle) was calculated as Δa*b*.

[0135] Δa*b*=(Δa* 2 +Δb* 2 ) 1 / 2

[0136] In addition, after placing the evaluation sample after the high-temperature test on a reflector (MIRO5 5011GP manufactured by Alanod), the reflected light was observed visually from the side of the optical laminate to evaluate the visibility of the color non-uniformity of the optical laminate. A case where the color non-uniformity was weakly visible was evaluated as A, and a case where it was strongly visible was evaluated as B.

[0137] [Example 1]

[0138] FIGS. 3(a) and (b) are schematic diagrams for explaining the method of manufacturing an adhesive layer in an embodiment. As shown in FIG. 3(a), a release film-attached adhesive layer (60) was prepared on a release film (62), having an adhesive layer (61) formed using an acrylic adhesive with a thickness of 20 μm. The adhesive layer (61) contained an ultraviolet absorber. As shown in FIG. 3(a), the release film-attached adhesive layer (60) was cut into a rectangle by cutting a cutting blade (65) at an angle θ of the leading portion (65a) along a direction parallel to the lamination direction of the release film-attached adhesive layer (60) from the side of the adhesive layer (61) (direction of the arrow in the drawing). Also, a single blade was used as the cutting blade (65). The cut surface of the rectangular release film attachment adhesive layer (60) after cutting was the surface that contacted the side on which the blade was formed among the two sides of the cutting blade (65) of the flat blade.

[0139] After bonding the adhesive layer (61) of the obtained rectangular adhesive layer (60) to the first protective layer side (triacetylcellulose film side) of the polarizing plate produced above, the release film (62) was peeled off. After bonding the surface of the COP film on the first phase difference layer side of the phase difference layer laminate produced above, which was peeled off to expose the surface of the adhesive layer (61) exposed by peeling off the release film (62), the COP film on the second phase difference layer side was peeled off to obtain an optical laminate (circular polarizing plate) having a layer structure of second protective layer / polarizing layer / first protective layer / adhesive layer (61) / first phase difference layer / adhesive layer / second phase difference layer. In addition, when manufacturing the optical laminate, corona treatment is performed on the bonding surface when bonding each layer, and when bonding, the long side and short side of each layer are aligned, and the absorption axis direction of the polarization layer is set to 45° with respect to the ground axis direction of the first phase difference layer.

[0140] The obtained optical laminate has a glue-deprived portion formed around its entire perimeter. Regarding the glue-deprived portion at any position on each side of the optical laminate, the distance L1 was measured in the order described above, and the average value was calculated. In addition, a high-temperature test was performed on the obtained optical laminate, and the change in the color of the reflected light was measured to evaluate the visibility for confirming the state of color non-uniformity. The results of these are shown in Table 1. Furthermore, from the measurement results of the distance L1 at each side, it was confirmed that the distance L1 of the glue-deprived portion around the entire perimeter of the optical laminate of the present embodiment is of the same magnitude as the value shown in Table 1.

[0141] [Example 2 and Comparative Example 1]

[0142] An optical laminate was obtained in the same manner as in Example 1, except that a rectangular adhesive layer (60) with a release film attached was obtained by using a cutting blade (flat blade) with an angle θ of the tip portion (65a) smaller than that used in Example 1, as a cutting blade used to cut the adhesive layer (60) (Fig. 3 (a)) with a release film attached. The obtained optical laminate has a glue-free portion formed around its entire perimeter. Regarding the glue-free portion at any position on each side of the optical laminate, the distance L1 was measured in the order described above, and the average value was calculated. In addition, a high-temperature test was performed on the obtained optical laminate, and the change in the color of the reflected light was measured to evaluate the visibility of the color non-uniformity. The results of these are shown in Table 1. Furthermore, from the measurement results of the distance L1 on each side, it was confirmed that the distance L1 of the glue-free portion around the entire perimeter of the optical laminate of this example is of the same magnitude as the value shown in Table 1.

[0143] Explanation of the symbols

[0144] 5: Glue-free portion, 11: Optical laminate, 12: Optical laminate, 21: First phase difference layer, 22: Second phase difference layer, 31: Adhesive layer, 35: Adhesive layer, 40: Polarizer, 41: Polarizing layer, 42: First protective layer, 43: Second protective layer, 60: Release film attachment adhesive layer, 61: Adhesive layer, 62: Release film, 65: Cutting blade, 65a: Blade tip portion.

Claims

Claim 1 An optical laminate having a polarizing plate including a polarizing layer, an adhesive layer, a first phase difference layer, and a second phase difference layer in that order, wherein the thickness of the polarizing plate is 2 μm or more and 150 μm or less, and the first phase difference layer and the second phase difference layer are liquid crystal layers that are cured layers of a liquid crystal compound, and the optical laminate has a glue-free portion at its end in the plane direction, wherein the glue-free portion is formed such that, in a cross-section passing through a portion where the polarizing layer and the adhesive layer overlap in the stacking direction, the innermost position at the end of the adhesive layer is located 3 μm or more and 50 μm or less inward from the outermost position at the end of the polarizing layer. Claim 2 delete Claim 3 In claim 1, the polarizing layer is an optical laminate in which a dichromatic pigment is adsorbed and oriented on a polyvinyl alcohol-based resin film. Claim 4 In claim 1, the optical laminate has a square or a square having a cutout on at least one side, and the cutout is formed on at least one side of the square. Claim 5 In claim 4, the above rectangle has a pair of long sides and a pair of short sides, the direction of the absorption axis of the polarization layer forms an angle of 45°±10° with respect to the long sides, and the above-mentioned missing portion is an optical laminate formed on at least one side of the pair of long sides and at least one side of the pair of short sides. Claim 6 In claim 4, the above rectangle has a pair of long sides and a pair of short sides, the direction of the absorption axis of the polarization layer forms an angle of 0°±10° with respect to the long side, and the above-mentioned missing portion is formed on at least one side of the pair of short sides, an optical laminate. Claim 7 In claim 4, the above rectangle has a pair of long sides and a pair of short sides, the direction of the absorption axis of the polarization layer forms an angle of 0°±10° with respect to the short side, and the above-mentioned missing portion is formed on at least one side of the pair of long sides, an optical laminate. Claim 8 An optical laminate having a protective layer on one or both sides of the polarizing layer in claim 1 or 3. Claim 9 delete Claim 10 In claim 1, the second phase difference layer is an optical laminate formed on the first phase difference layer through an adhesive layer. Claim 11 An optical laminate that is a circular polarizer in paragraph 1 or 3.

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