Optical laminate

Abstract

To provide an optical laminate that can suppress cracking in a polarizer and a luminance enhancing film despite inclusion of a recess as an irregular shape processing part.SOLUTION: An optical laminate according to an embodiment of the present invention has an irregular shape processing part. The optical laminate comprises a luminance enhancing film, a polarizing plate including a polarizer, and a resin film. The luminance enhancing film transmits polarized light having a specific polarization state, and reflects light having a polarization state other than the polarized light. The polarizing plate is pasted to the luminance enhancing film with a first adhesive layer therebetween. The resin film is pasted to the luminance enhancing film on a side opposite to the polarizing plate with a second adhesive layer therebetween. The luminance enhancing film has a transmission axis and a reflection axis. The transmission axis extends in a first direction. The reflection axis extends in a second direction orthogonal to the first direction. The irregular shape processing part has a recess. The recess is depressed in the second direction from a peripheral edge of the optical laminate toward the inside when seen from a lamination direction of the optical laminate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Conventionally, image display devices, such as liquid crystal display devices and electroluminescence (EL) display devices (e.g., organic EL display devices and inorganic EL display devices), have rapidly become widespread. Among these image display devices, particularly in liquid crystal display devices, the use of an optical laminate including a polarizer and a brightness enhancement film has been proposed to improve light utilization efficiency (see, for example, Patent Document 1). Recently, however, it has become desirable to form a contoured portion (typically a recess) in the optical laminate depending on the application of the optical laminate. However, in an optical laminate including a polarizer and a brightness enhancement film and having a contoured portion, cracks may occur in both the polarizer and the brightness enhancement film when exposed to temperature changes. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-118776 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention has been made to solve the above-mentioned conventional problems, and its main object is to provide an optical laminate that can suppress cracks in polarizers and brightness enhancement films despite having recesses as irregularly shaped processed portions. [Means for solving the problem]

[0005] [1] An optical laminate according to an embodiment of the present invention has a contoured portion. The optical laminate includes a brightness enhancement film, a polarizing plate including a polarizer, and a resin film. The brightness enhancement film transmits polarized light having a specific polarization state and reflects light having other polarization states. The polarizing plate is attached to the brightness enhancement film via a first adhesive layer. The resin film is attached to the brightness enhancement film on the side opposite the polarizing plate via a second adhesive layer. The brightness enhancement film has a transmission axis and a reflection axis. The transmission axis extends in a first direction. The reflection axis extends in a second direction perpendicular to the first direction. The contoured portion has a recess. When viewed from the stacking direction of the optical laminate, the recess is recessed in the second direction from the peripheral edge of the optical laminate toward the inside. [2] In the optical laminate according to the above [1], the polarizer may have a thickness of 8 μm or less. [3] In the optical laminate according to the above [1] or [2], the brightness enhancement film may have a breaking strength in the second direction at 23° C. of 150 MPa or more. [4] In the optical laminate according to any one of [1] to [3] above, the resin film may have a thickness of 25 μm or more. [5] In the optical laminate according to any one of [1] to [4] above, the resin film may have a breaking strength in the second direction at 23° C. of 85 MPa or more. [Effects of the Invention]

[0006] According to an embodiment of the present invention, in an optical laminate having a recess as a contoured portion, cracks in a polarizer and a brightness enhancement film can be suppressed. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic cross-sectional view of an optical laminate according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic plan view of the optical laminate of FIG. [Figure 3]FIG. 3 is a schematic cross-sectional view of an optical laminate according to another embodiment of the present invention. [Figure 4] FIG. 4 is a schematic perspective view of an example of a brightness enhancement film included in the optical laminate of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] The following describes embodiments of the present invention, but the present invention is not limited to these embodiments. Note that the drawings are drawn schematically or conceptually to facilitate visibility and understanding, and the length, width, shape, size, ratio, direction, number, etc. may differ from the actual ones, and there may be no correspondence between the drawings.

[0009] (Definition of terms and symbols) The definitions of terms and symbols used in this specification are as follows. (1) Refractive index (nx, ny, nz) "nx" is the refractive index in the direction in which the in-plane refractive index is greatest (i.e., the slow axis direction), "ny" is the refractive index in the direction perpendicular to the slow axis in the plane (i.e., the fast axis direction), and "nz" is the refractive index in the thickness direction. (2) Substantially parallel or perpendicular The expressions "substantially perpendicular" and "approximately perpendicular" include the case where the angle between two directions is 90°±10°, preferably 90°±7°, and more preferably 90°±5°. The expressions "substantially parallel" and "approximately parallel" include the case where the angle between two directions is 0°±10°, preferably 0°±7°, and more preferably 0°±5°. Furthermore, when simply referring to "orthogonal" or "parallel" in this specification, this can include the state of being substantially perpendicular or substantially parallel.

[0010] A. Overview of optical laminate FIG. 1 is a schematic cross-sectional view of an optical laminate according to one embodiment of the present invention; FIG. 2 is a schematic plan view of the optical laminate of FIG. As shown in FIG. 1, the optical laminate 100 includes a brightness enhancement film 1, a polarizing plate 2 including a polarizer 21, and a resin film 3. The brightness enhancement film 1 can transmit polarized light having a specific polarization state and reflect light having other polarization states. The brightness enhancement film 1 has a transmission axis extending in a first direction and a reflection axis extending in a second direction perpendicular to the first direction (see FIG. 2). The first and second directions are planar directions of the brightness enhancement film 1 and are substantially perpendicular to the thickness direction of the brightness enhancement film 1. The polarizing plate 2 is attached to the brightness enhancement film 1 via a first pressure-sensitive adhesive layer 41. The resin film 3 is attached to the brightness enhancement film 1 on the side opposite to the polarizing plate 2 via a second pressure-sensitive adhesive layer 42. That is, the optical laminate 100 includes the resin film 3, the second pressure-sensitive adhesive layer 42, the brightness enhancement film 1, the first pressure-sensitive adhesive layer 41, and the polarizing plate 2, in this order. As shown in FIG. 2, the optical laminate 100 has an irregularly shaped portion 5. In this specification, the term "irregularly shaped portion" refers to a portion that has been processed into a special shape that differs from a general shape (typically rectangular). The irregularly shaped portion 5 includes at least a recess 51. When viewed from the lamination direction of the optical laminate 100, the recess 51 is recessed from the peripheral edge of the optical laminate 100 toward the inside in a second direction in which the reflection axis R of the brightness enhancement film 1 extends. In other words, the recessed direction of the recess 51 and the second direction are substantially parallel to each other. The present inventors have investigated various arrangements of recesses as contoured portions depending on the design of an image display device (typically a liquid crystal display device) to which an optical laminate including a polarizer and a brightness enhancement film is applied. They discovered that cracks (particularly cracks along the extension direction of the reflection axis) are likely to occur when the recesses are recessed in the extension direction of the reflection axis of the brightness enhancement film. As a result of extensive research into how to suppress cracks in such optical laminates, they have found that the occurrence of cracks in the polarizer and the brightness enhancement film can be suppressed if the optical laminate has a specific laminate structure. More specifically, when a polarizing plate is attached to one side of the brightness enhancement film via a first pressure-sensitive adhesive layer and a resin film is attached to the brightness enhancement film on the side opposite the polarizing plate via a second pressure-sensitive adhesive layer, cracks in the polarizer and the brightness enhancement film (particularly cracks when the optical laminate is exposed to temperature changes in the range of −40°C to 85°C) can be sufficiently suppressed, even if the recesses are recessed in the extension direction of the reflection axis of the brightness enhancement film.

[0011] The breaking strength in the second direction of the optical laminate 100 at 23° C. is, for example, 2900 MPa or more, preferably 3000 MPa or more, more preferably 3200 MPa or more, and even more preferably 4000 MPa or more. On the other hand, the breaking strength in the second direction of the optical laminate 100 at 23° C. is, for example, 6000 MPa or less, preferably 5000 MPa or less, and more preferably 4500 MPa or less. When the breaking strength of the optical laminate is in this range, cracking in the optical laminate can be more stably suppressed. The breaking strength is measured in accordance with, for example, JIS-K7161. The breaking strength of the optical laminate 100 in the first direction at 23° C. is, for example, 5000 MPa to 6600 MPa, and preferably 5700 MPa to 6200 MPa.

[0012] The thickness of the brightness-enhancing film 1 can be set arbitrarily and appropriately. The thickness of the brightness-enhancing film 1 is, for example, 10 μm or more, preferably 20 μm or more. On the other hand, the thickness of the brightness-enhancing film 1 is, for example, 150 μm or less, preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less. When the brightness-enhancing film has such a thickness, the breaking strength of the brightness-enhancing film can be stably adjusted to be within the above-mentioned range.

[0013] The breaking strength of the resin film 3 in the second direction at 23° C. is, for example, 40 MPa or more, preferably 60 MPa or more, and more preferably 85 MPa or more. When the resin film has such breaking strength, cracks in the resin film can be sufficiently suppressed. On the other hand, the breaking strength of the resin film in the second direction at 23° C. is, for example, 200 MPa or less, preferably 160 MPa or less, more preferably 140 MPa or less, even more preferably 120 MPa or less, and particularly preferably 100 MPa or less. When the brightness-enhancing film has such breaking strength, cracking in the brightness-enhancing film can be more stably suppressed. The range of the breaking strength of the resin film 3 in the first direction at 23° C. is the same as, for example, the range of the breaking strength of the resin film 3 in the second direction.

[0014] At 23°C, the breaking strength in the second direction of the resin film 3 is typically smaller than the breaking strength in the second direction of the brightness enhancement film 1. The difference in breaking strength in the second direction between the brightness enhancement film 1 and the resin film 3 at 23°C (=breaking strength in the second direction of the brightness enhancement film - breaking strength in the second direction of the resin film) is, for example, 200 MPa or less, preferably 150 MPa or less, and more preferably 120 MPa or less. On the other hand, the difference in breaking strength in the second direction between the brightness enhancement film 1 and the resin film 3 at 23°C is, for example, 0 MPa or more, preferably 10 MPa or more, more preferably 50 MPa or more, even more preferably 80 MPa or more, and particularly preferably 90 MPa or more.

[0015] The thickness of the resin film 3 can be set arbitrarily and appropriately. The thickness of the resin film 3 is, for example, 10 μm or more, preferably 25 μm or more, and more preferably 30 μm or more. When the resin film has such a thickness, warping of the optical laminate in a high-temperature, high-humidity environment can be suppressed. On the other hand, the thickness of the resin film 3 is, for example, 60 μm or less, preferably 40 μm or less. When the resin film has such a thickness, the breaking strength of the resin film can be stably adjusted to be within the above-mentioned range.

[0016] The moisture permeability of the resin film 3 is, for example, 1000 g / m 2 24h or less, preferably 400g / m 2 The lower limit of the moisture permeability of the resin film 3 is typically 10 g / m 2 The moisture permeability of the resin film is measured, for example, in accordance with the moisture permeability test (cup method) of JIS Z0208, in an atmosphere of 40°C temperature and 92% RH, over an area of ​​1 m 2 The moisture permeability is measured by the amount of water vapor (g) that passes through a sample in 24 hours. When the moisture permeability of the resin film is in this range, warping of the optical laminate in a high-temperature, high-humidity environment can be stably suppressed.

[0017] As described above, the polarizing plate 2 includes the polarizer 21. The direction in which the absorption axis of the polarizer 21 extends is typically substantially perpendicular to the first direction in which the transmission axis of the brightness enhancement film 1 extends, and is substantially parallel to the second direction in which the reflection axis of the brightness enhancement film 1 extends. The thickness of the polarizer 21 can be set arbitrarily and appropriately. For example, it is 15 μm or less, preferably 12 μm or less, and more preferably 8 μm or less. On the other hand, the thickness of the polarizer 21 is, for example, 1 μm or more, and preferably 3 μm or more. If the polarizer has such a thickness, curling during heating can be well suppressed, and good appearance durability during heating can be obtained.

[0018] 1, in one embodiment, the polarizing plate 2 includes a protective layer 22 in addition to a polarizer 21. The protective layer 22 is provided on at least one surface of the polarizer 21. That is, the protective layer 22 may be provided on both surfaces of the polarizer 21, or may be provided on only one surface of the polarizer 21. The protective layer 22 is typically attached to the polarizer 21 via any appropriate adhesive layer (not shown).

[0019] In the illustrated example, the protective layer 22 is provided on only one surface of the polarizer 21. In FIG. 1, the protective layer 22 is provided on the surface of the polarizer 21 on the brightness enhancement film side. In this embodiment, the protective layer 22 is in contact with the first pressure-sensitive adhesive layer 41. 3, the protective layer 22 may be provided on the surface of the polarizer 21 opposite to the brightness enhancement film 1. In this case, the polarizer 21 comes into contact with the first pressure-sensitive adhesive layer 41.

[0020] The thickness of the protective layer 22 is, for example, 1 μm to 1 mm, preferably 1 μm to 500 μm, and more preferably 5 μm to 150 μm.

[0021] 1, in one embodiment, the optical laminate 100 further includes a third pressure-sensitive adhesive layer 43. The third pressure-sensitive adhesive layer 43 is located on the opposite side of the polarizing plate 2 from the brightness enhancement film 1. This allows the optical laminate 100 to be attached to an image display panel, which will be described later, via the third pressure-sensitive adhesive layer 43. In the illustrated example, the third pressure-sensitive adhesive layer 43 is laminated directly on the polarizing plate 2. More specifically, the third pressure-sensitive adhesive layer 43 is provided on the surface of the polarizer 21 opposite to the protective layer 22. As shown in FIG. 3, the third pressure-sensitive adhesive layer 43 may be provided on the surface of the protective layer 22 opposite to the polarizer 21.

[0022] The optical laminate 100 may further include a release liner 6. The release liner 6 is located on the opposite side of the third pressure-sensitive adhesive layer 43 from the polarizing plate 2, and is temporarily attached to the surface of the third pressure-sensitive adhesive layer 43. The release liner 6 is temporarily attached to the third pressure-sensitive adhesive layer 43 until the optical laminate is attached to the image display panel, and is peeled off from the third pressure-sensitive adhesive layer 43 when the optical laminate is attached.

[0023] Hereinafter, each component of the optical laminate 100 will be specifically described with reference to FIG.

[0024] B. Brightness enhancement film The brightness enhancement film 1 is typically a reflective polarizing plate. The brightness enhancement film 1 may be either a linear polarization separation type or a circular polarization separation type. A linear polarization separation type brightness enhancement film will be described below as an example. An example of a circular polarization separation type brightness enhancement film is a laminate of a film in which cholesteric liquid crystal is fixed and a λ / 4 plate.

[0025] FIG. 4 is a schematic perspective view of an example of a brightness enhancement film. The brightness enhancement film is a multilayer laminate in which birefringent layers A and substantially non-birefringent layers B are alternately stacked. For example, the total number of layers in such a multilayer laminate can be 50 to 1,000. In the illustrated example, the refractive index nx in the x-axis direction of layer A is larger than the refractive index ny in the y-axis direction, and the refractive index nx in the x-axis direction of layer B and the refractive index ny in the y-axis direction are substantially the same. Therefore, the refractive index difference between layer A and layer B is large in the x-axis direction and substantially zero in the y-axis direction. As a result, the x-axis direction is the reflection axis, and the y-axis direction is the transmission axis. The refractive index difference between layer A and layer B in the x-axis direction is preferably 0.2 to 0.3. The x-axis direction corresponds to the stretching direction of the brightness enhancement film in the manufacturing method thereof.

[0026] The A layer is preferably made of a material that exhibits birefringence upon stretching. Typical examples of such materials include naphthalenedicarboxylic acid polyesters (e.g., polyethylene naphthalate), polycarbonates, and acrylic resins (e.g., polymethyl methacrylate), with polyethylene naphthalate being preferred. The B layer is preferably made of a material that does not substantially exhibit birefringence upon stretching. Typical examples of such materials include copolyesters of naphthalenedicarboxylic acid and terephthalic acid.

[0027] The brightness enhancement film transmits light having a first polarization direction (e.g., p-wave) and reflects light having a second polarization direction (e.g., s-wave) perpendicular to the first polarization direction at the interface between the A layer and the B layer. At the interface between the A layer and the B layer, part of the reflected light is transmitted as light having the first polarization direction and part is reflected as light having the second polarization direction. This reflection and transmission are repeated many times within the brightness enhancement film, thereby increasing the light utilization efficiency.

[0028] The brightness-enhancing film preferably consists of only Layer A and Layer B. That is, the brightness-enhancing film preferably does not include a surface treatment layer (e.g., a hard coat (HC) layer). When the brightness-enhancing film consists of only Layer A and Layer B, the breaking strength of the brightness-enhancing film can be more stably adjusted within the above-mentioned range.

[0029] As the brightness enhancement film, for example, the one described in JP-A-9-507308 can be used. As the brightness enhancement film, a commercially available product may be used as it is, or a commercially available product may be used after secondary processing (for example, stretching). Examples of commercially available products include DBEF and APF, both manufactured by 3M.

[0030] C. Polarizing plate As shown in FIG. 1, the polarizing plate 2 is attached to the surface of the brightness enhancement film 1 opposite to the resin film 3 via a first adhesive layer 41.

[0031] C-1.Polarizer Any appropriate polarizer can be adopted as the polarizer 21 included in the polarizing plate 2. For example, the resin film forming the polarizer may be a single-layer resin film or a laminate of two or more layers.

[0032] Specific examples of polarizers made of a single-layer resin film include hydrophilic polymer films such as polyvinyl alcohol (PVA) films, partially formalized PVA films, and partially saponified ethylene-vinyl acetate copolymer films that have been dyed with iodine or a dichroic substance such as a dichroic dye and stretched, as well as polyene-based oriented films such as dehydrated PVA films and dehydrochlorinated polyvinyl chloride films. Polarizers obtained by dyeing PVA films with iodine and uniaxially stretching them are preferred because of their excellent optical properties.

[0033] The dyeing with iodine is carried out, for example, by immersing the PVA film in an aqueous iodine solution. The stretching ratio in the uniaxial stretching is preferably 3 to 7 times. The stretching may be carried out after the dyeing treatment or while dyeing. Alternatively, the PVA film may be stretched and then dyed. If necessary, the PVA film may be subjected to a swelling treatment, a crosslinking treatment, a washing treatment, a drying treatment, or the like. For example, by immersing the PVA film in water and washing it before dyeing, it is possible to wash away dirt and antiblocking agents on the surface of the PVA film, and also to swell the PVA film, thereby preventing uneven dyeing.

[0034] Specific examples of polarizers obtained using laminates include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a polarizer obtained using a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate. A polarizer obtained using a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate can be produced, for example, by applying a PVA-based resin solution to the resin substrate and drying the resin substrate to form a PVA-based resin layer on the resin substrate, thereby obtaining a laminate of the resin substrate and the PVA-based resin layer, and then stretching and dyeing the laminate to convert the PVA-based resin layer into a polarizer. In one embodiment of the present invention, a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin is preferably formed on one side of the resin substrate. Stretching typically involves immersing the laminate in an aqueous boric acid solution and stretching it. Furthermore, stretching can optionally further include in-air stretching the laminate at an elevated temperature (e.g., 95°C or higher) before stretching in the aqueous boric acid solution. Additionally, in one embodiment of the present invention, the laminate is preferably subjected to a drying shrinkage treatment in which the laminate is heated while being transported in the longitudinal direction, thereby shrinking the laminate by 2% or more in the width direction. Typically, the manufacturing method of this embodiment includes subjecting the laminate to an in-air auxiliary stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying shrinkage treatment, in this order. By introducing auxiliary stretching, it is possible to increase the crystallinity of PVA, even when PVA is coated on a thermoplastic resin, thereby achieving high optical properties. Furthermore, by simultaneously increasing the orientation of PVA in advance, problems such as a decrease in orientation or dissolution of PVA when immersed in water in the subsequent dyeing or stretching steps can be prevented, thereby achieving high optical properties. Furthermore, when the PVA-based resin layer is immersed in a liquid, the disordering of the orientation of polyvinyl alcohol molecules and the decrease in orientation can be suppressed compared to when the PVA-based resin layer does not contain a halide. This can improve the optical properties of a polarizer obtained through treatment steps in which the laminate is immersed in a liquid, such as a dyeing treatment and an underwater stretching treatment. Furthermore, the optical properties can be improved by shrinking the laminate in the width direction through drying shrinkage treatment.The obtained resin substrate / polarizer laminate may be used as is (i.e., the resin substrate may be used as a protective layer for the polarizer), or the resin substrate may be peeled off from the resin substrate / polarizer laminate and any appropriate protective layer depending on the purpose may be laminated on the peeled surface. Details of such a polarizer manufacturing method are described in, for example, JP 2012-73580 A and Japanese Patent No. 6470455 A. The entire disclosures of these publications are incorporated herein by reference.

[0035] The polarizer preferably exhibits absorption dichroism at any wavelength between 380 nm and 780 nm. The single transmittance of the polarizer is, for example, 41.5% to 46.0%, preferably 43.0% to 46.0%, and more preferably 44.5% to 46.0%. The degree of polarization of the polarizer is preferably 97.0% or more, more preferably 99.0% or more, and even more preferably 99.9% or more.

[0036] C-2.Protective layer The protective layer 22 of the polarizing plate 2 is made of any appropriate resin film that can be used as a protective layer for a polarizer. Examples of materials for the protective layer include cycloolefin (COP) resins such as polynorbornene, polyesters such as polyethylene terephthalate (PET), cellulose resins such as triacetyl cellulose (TAC), and transparent resins such as polycarbonate (PC), (meth)acrylic, polyvinyl alcohol, polyamide, polyimide, polyethersulfone, polysulfone, polystyrene, polyolefin, and acetate. Other examples include thermosetting or ultraviolet-curable resins such as (meth)acrylic, urethane, (meth)acrylic urethane, epoxy, and silicone. (Meth)acrylic includes acrylic and / or methacrylic. Other examples include glassy polymers such as siloxane polymers. Polymer films described in JP 2001-343529 A (WO 01 / 37007) can also be used. Examples of materials that can be used for this film include a resin composition containing a thermoplastic resin having substituted or unsubstituted imide groups in its side chains and a thermoplastic resin having substituted or unsubstituted phenyl and nitrile groups in its side chains, such as a resin composition containing an alternating copolymer of isobutene and N-methylmaleimide and an acrylonitrile-styrene copolymer.The polymer film can be, for example, an extrusion molded product of the above resin composition. The materials for the protective layer may be used alone or in combination. Among the materials for the protective layer, a (meth)acrylic transparent resin is preferable.

[0037] D. Resin film The resin film 3 is attached to the surface of the brightness enhancement film 1 opposite to the polarizing plate 2 via a second pressure-sensitive adhesive layer 42. In one embodiment, the resin film 3 is located on one outermost surface in the stacking direction of the optical laminate 100. When the resin film 3 is located on the outermost surface of the optical laminate 100, the resin film 3 can function as a surface protection film.

[0038] The resin film 3 is made of any appropriate resin material, such as the same resin material as that used for the protective layer described above. The materials for the resin film 3 may be used alone or in combination. Among the materials for the resin film 3, preferred examples include TAC-based transparent resins, PC-based transparent resins, and (meth)acrylic-based transparent resins, more preferred examples include TAC-based transparent resins and (meth)acrylic-based transparent resins, and even more preferred examples include (meth)acrylic-based transparent resins. Furthermore, the resin film 3 may contain any appropriate additive.

[0039] In one embodiment, any appropriate surface treatment layer is provided on the surface of the resin film 3 opposite to the brightness enhancement film 1. A typical example of the surface treatment layer is a hard coat (HC) layer. The thickness of the surface treatment layer is, for example, 2 μm to 10 μm, and preferably 5 μm to 7 μm.

[0040] E. First adhesive layer to third adhesive layer The first adhesive layer 41 is located between the brightness enhancement film 1 and the polarizing plate 2 and bonds them together. The second adhesive layer 42 is located between the brightness enhancement film 1 and the resin film 3 and bonds them together. The third adhesive layer 43 is provided on the surface of the polarizing plate 2 opposite to the brightness enhancement film 1.

[0041] Each of the first adhesive layer 41, the second adhesive layer 42, and the third adhesive layer 43 is composed of an arbitrary adhesive. The adhesives constituting the first adhesive layer 41, the second adhesive layer 42, and the third adhesive layer 43 may be the same as or different from each other. Examples of adhesives include (meth)acrylic adhesives, rubber adhesives, silicone adhesives, polyester adhesives, urethane adhesives, epoxy adhesives, and polyether adhesives. By adjusting the type, number, combination, and compounding ratio of the monomers that form the base resin of the adhesive, as well as the amount of crosslinking agent, reaction temperature, reaction time, etc., adhesives with desired properties can be prepared according to the purpose. The base resins of the adhesive may be used alone or in combination of two or more. Of these adhesives, (meth)acrylic adhesives are preferable.

[0042] A (meth)acrylic pressure-sensitive adhesive typically contains a (meth)acrylic polymer as a main component. The (meth)acrylic polymer is contained in the pressure-sensitive adhesive in a proportion of, for example, 50% by mass or more, preferably 70% by mass or more, and more preferably 90% by mass or more of the solid content of the pressure-sensitive adhesive. The (meth)acrylic polymer contains a structural unit derived from an alkyl (meth)acrylate. The (meth)acrylate includes an acrylate and / or a methacrylate. The content of structural units derived from alkyl (meth)acrylate in the (meth)acrylic polymer is, for example, 80% by mass or more, preferably 90% by mass or more. Examples of the alkyl group of the alkyl (meth)acrylate include linear or branched alkyl groups having 1 to 18 carbon atoms. The average number of carbon atoms in the alkyl group is preferably 3 to 9, more preferably 3 to 6. The alkyl (meth)acrylate is particularly preferably butyl acrylate.

[0043] The (meth)acrylic polymer may contain, in addition to a structural unit derived from an alkyl (meth)acrylate, a structural unit derived from a copolymerizable monomer copolymerizable with the alkyl (meth)acrylate. Examples of copolymerizable monomers include carboxyl group-containing monomers, hydroxyl group-containing monomers, amide group-containing monomers, aromatic ring-containing (meth)acrylates, heterocycle-containing vinyl monomers, etc. The copolymerizable monomers may be used alone or in combination. Of the copolymerizable monomers, preferred are carboxyl group-containing monomers such as (meth)acrylic acid; and hydroxyl group-containing monomers such as 4-hydroxybutyl acrylate. The content of the structural units derived from copolymerization monomers in the (meth)acrylic polymer is, for example, 0% by mass to 20% by mass, preferably 0.5% by mass to 15% by mass, more preferably 0.8% by mass to 13% by mass, and particularly preferably 5% by mass to 12% by mass.

[0044] The (meth)acrylic pressure-sensitive adhesive preferably contains a silane coupling agent and / or a crosslinking agent. Examples of the silane coupling agent include an epoxy group-containing silane coupling agent. Examples of the crosslinking agent include an isocyanate-based crosslinking agent and a peroxide-based crosslinking agent. The (meth)acrylic pressure-sensitive adhesive may further contain an antioxidant and / or a conductive agent. Details of the (meth)acrylic pressure-sensitive adhesive are described in, for example, JP 2006-183022 A, JP 2015-199942 A, JP 2018-053114 A, JP 2016-190996 A, and WO 2018 / 008712 A, the disclosures of which are incorporated herein by reference.

[0045] F. Release liner The release liner 6 is temporarily attached to the surface of the third pressure-sensitive adhesive layer 43. In one embodiment, the release liner 6 is located on the outermost surface of the optical laminate 100, opposite the resin film 3 in the lamination direction. The release liner 6 is made of any appropriate resin material. Examples of resin materials for the release liner include polyethylene terephthalate (PET), polyethylene, and polypropylene. The resin film materials may be used alone or in combination. A release treatment layer may be provided on the surface of the release liner 6 that comes into contact with the third pressure-sensitive adhesive layer 43. Examples of release treatment agents that form the release treatment layer include silicone-based release treatment agents, fluorine-based release treatment agents, and long-chain alkyl acrylate-based release agents. The release treatment agents may be used alone or in combination.

[0046] The thickness of the release liner 6 is, for example, 5 μm to 60 μm, and preferably 20 μm to 45 μm. When a release treatment layer is applied, the thickness of the release liner includes the thickness of the release treatment layer.

[0047] G. Irregular shape processing section As shown in FIG. 2, the optical laminate 100 has any appropriate outer shape when viewed from the stacking direction. The outer shape of the optical laminate 100 excluding the irregularly processed portion 5 is typically a substantially polygonal shape, preferably a substantially quadrangular shape, and more preferably a substantially rectangular shape. In the illustrated example, the optical laminate 100 has a substantially rectangular shape when viewed from the stacking direction. In this embodiment, the longitudinal direction (long side direction) of the optical laminate 100 is substantially parallel to a first direction in which the transmission axis of the brightness enhancement film 1 extends and substantially perpendicular to a second direction in which the reflection axis of the brightness enhancement film 1 extends. Furthermore, the width direction (short side direction) of the optical laminate 100 is substantially perpendicular to the first direction in which the transmission axis of the brightness enhancement film 1 extends and substantially parallel to a second direction in which the reflection axis of the brightness enhancement film 1 extends. The dimension of the optical laminate 100 in the longitudinal direction (long side direction) is, for example, 100 mm to 400 mm, and the dimension in the width direction (short side direction) is typically 50 mm to 300 mm.

[0048] In the illustrated example, the peripheral edge of the optical laminate 100 seen from the stacking direction includes a first long side 100a, a second long side 100b, a first short side 100c, and a second short side 100d. The first long side 100a and the second long side 100b are spaced apart from each other in the second direction. Each of the first long side 100a and the second long side 100b extends along the first direction. The first short side 100c and the second short side 100d are spaced apart from each other in the first direction. Each of the first short side 100c and the second short side 100d extends along the second direction.

[0049] As described above, the optical laminate 100 has at least a recess 51 as the profiled portion 5. In one embodiment, the recess 51 is recessed in the second direction from the first long side 100a to the second long side 100b when viewed from the stacking direction of the optical laminate. Examples of the recess 51 include a V-shaped notch and a U-shaped notch.

[0050] The maximum depth (maximum dimension in the second direction) of the recesses 51 is, for example, 2% to 15%, and preferably 3% to 10%, when the dimension in the second direction (width direction) of the optical laminate 100 is taken as 100%. The maximum depth (maximum dimension in the second direction) of the recesses 51 is, for example, 4 mm to 30 mm, and preferably 6 mm to 15 mm. The maximum width (maximum dimension in the first direction) of the recess 51 is, for example, 2% to 20%, and preferably 5% to 15%, when the dimension in the first direction (longitudinal direction) of the optical laminate 100 is taken as 100%. The maximum width (maximum dimension in the first direction) of the recess 51 is, for example, 5 mm to 65 mm, and preferably 15 mm to 50 mm.

[0051] The optical laminate 100 may further have other irregularly shaped portions 5 in addition to the recessed portions 51. In the illustrated example, the optical laminate 100 further has a first chamfered portion 52 and a second chamfered portion 53 as the irregularly shaped portions 5. The first chamfered portion 52 is formed by chamfering the corner where the first long side 100a and the first short side 100c are connected. The second chamfered portion 53 is formed by chamfering the corner where the first long side 100a and the second short side 100d are connected. In the illustrated example, the first chamfered portion 52 and the second chamfered portion 53 each have an arc shape. The radius of curvature of each of the first chamfered portion 52 and the second chamfered portion 53 is, for example, 5 mm to 20 mm.

[0052] H. Method for manufacturing optical laminate Next, a method for producing the optical laminate 100 according to one embodiment of the present invention will be described. The manufacturing method of the optical laminate 100 includes the steps of punching out a laminate chip having the above-mentioned irregularly shaped portion from an original film having the above-mentioned laminate structure, and cutting the end face of the laminate chip.

[0053] In one embodiment, first, a long raw film is prepared. To prepare the raw film, for example, a long polarizing plate 2 is attached to a long brightness enhancement film 1 via a first adhesive layer 41, and a long resin film 3 is attached to the brightness enhancement film 1 via a second adhesive layer 42, by any appropriate method (typically, roll-to-roll). Thereafter, if necessary, a third adhesive layer 43 is formed on the polarizing plate 2 on the side opposite to the brightness enhancement film 1 by any appropriate method, and a release liner 6 is attached to the surface of the third adhesive layer 43. Next, the laminate chips having the above-mentioned contoured processed portions 5 are punched out from the raw film by any appropriate punching means.

[0054] Thereafter, the peripheral end surface of the laminate chip having the profiled portion 5 is machined using any appropriate milling tool. Examples of the milling tool include an end mill that can rotate about an axis parallel to the stacking direction of the laminate chips, and a face mill that can rotate about an axis perpendicular to the stacking direction of the laminate chips. In one embodiment, the milling tool is an end mill.

[0055] The end mill comes into contact with the peripheral end surface of the laminate chip to perform cutting. Any appropriate configuration can be adopted for the end mill. The end mill has a cutting blade. The number of cutting blade edges can be appropriately set. The number of cutting blade edges is, for example, 1 to 6, preferably 1 to 4. The helix angle of the cutting blade is, for example, 0° to 70°, preferably 10° to 60°. Examples of materials for the cutting blade include cemented carbide and high-speed steel, and cemented carbide is preferred. The Vickers hardness (HV hardness) of the cutting blade is, for example, 800 to 2500, preferably 1500 to 1900.

[0056] The rotation direction of the end mill may be clockwise or counterclockwise in a plan view. When cutting the end face of the laminate chip, the end mill rotates at a constant speed. The rotation speed of the end mill is, for example, 300 rpm to 100,000 rpm, and preferably 500 rpm to 50,000 rpm.

[0057] The end mill moves relative to the laminate chip while rotating as described above. The end mill may move while the laminate chip is fixed, or the laminate chip may move while the end mill is fixed. In one embodiment, the end mill moves around the fixed laminate chip in one direction at the feed rate described below, cutting the entire peripheral end surface of the laminate chip. The feed speed of the end mill (the relative movement speed with respect to the peripheral end surface of the optical laminate) is, for example, 10 mm / min to 5000 mm / min, and preferably 50 mm / min to 3500 mm / min.

[0058] In this manner, the entire peripheral end surface of the laminate chip, including the inner surface of the recess 51, is appropriately cut, and the above-described optical laminate 100 is manufactured.

[0059] I. Image display device The optical laminate 100 described in the above items A to H can be applied to an image display device. Typical examples of the image display device include a liquid crystal display device and an electroluminescence (EL) display device (for example, an organic EL display device or an inorganic EL display device). The image display device typically includes an image display panel and an optical laminate 100. The image display panel typically includes an image display cell. The optical laminate 100 is typically attached to the image display panel by the third pressure-sensitive adhesive layer 43 after the release liner 6 is peeled from the third pressure-sensitive adhesive layer 43. In one embodiment, the optical laminate 100 is applied to a liquid crystal display device. In this case, the optical laminate 100 is typically attached to the side opposite to the viewing side of the liquid crystal display panel (i.e., the backlight side) by the third pressure-sensitive adhesive layer 43. [Example]

[0060] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. The methods for measuring each property are as follows. Unless otherwise specified, "parts" and "%" in the examples and comparative examples are based on mass.

[0061] (1) Measurement of the breaking strength of the optical laminate and the resin film Dumbbell-shaped samples measuring 150 mm x 25 mm were cut out from the optical laminates obtained in the Examples and Comparative Examples and from the resin films used in the Examples and Comparative Examples. The longitudinal direction of the samples cut out from the optical laminates was substantially parallel to the second direction (MD) in which the transmission axis of the brightness enhancement film extended. Also, the longitudinal direction of the samples cut out from the resin films was substantially parallel to the MD of the resin films. Next, a tensile test was performed on the sample using a tensile tester (Autograph, manufactured by Shimadzu Corporation) at a chuck distance of 100 mm and a speed of 300 mm / min. The breaking strength was calculated from the obtained tensile strain. The results are shown in Table 1.

[0062] (2) Heat cycle test for optical laminates After the release liner was peeled off from the third pressure-sensitive adhesive layer of the optical laminate obtained in the Examples and Comparative Examples, the optical laminate was attached to a glass plate via the third pressure-sensitive adhesive layer. The optical laminate attached to the glass plate was then left at -40°C for 23 minutes, then heated to 85°C at a heating rate of 20°C / min, left at 85°C for 23 minutes, and then cooled to -40°C at a heating rate of 20°C / min. This cycle was repeated 300 times. The brightness-enhancing film and polarizer were then observed using a microscope from the side opposite the polarizing plate to determine whether cracks had occurred at their end faces, and evaluated according to the following criteria. The results are shown in Table 1. (2-1) Brightness enhancement film O: No cracks. △: Cracks occurred in the surface direction of the brightness enhancement film (but did not penetrate the brightness enhancement film). ×: The crack penetrates the brightness enhancement film in the surface direction. (2-2) Polarizers ◯: Crack length is 250 μm or less. ×: The crack length is more than 250 μm and less than 500 μm.

[0063] (3) Surface abrasion resistance of optical laminates After peeling the release liner from the third pressure-sensitive adhesive layer of the optical laminate obtained in the Examples and Comparative Examples, the optical laminate was attached to a glass plate via the third pressure-sensitive adhesive layer to prepare a sample. The surface of the optical laminate opposite the glass plate (the surface of the resin film in the Examples and the surface of the brightness-enhancing film in the Comparative Examples) was then scratched with a pencil hardness tester using a hardness of B to 3H, and the surface abrasion resistance of the optical laminate was evaluated according to the following criteria. The results are shown in Table 1. ◯: In the pencil hardness test, the surface treatment does not peel off even at a hardness of less than H. ×: In the pencil hardness test, the hardness was less than H and peeling occurred in the surface treatment.

[0064] (4) Warping After peeling the release liner from the third adhesive layer of the optical laminate obtained in the examples and comparative examples, the optical laminate was attached to a glass plate with a thickness of 0.55 mm using the third adhesive layer to prepare a sample. The sample was then placed on a flat surface along the horizontal direction. In this state, the distance (height) between the outer edge and the center of the sample in the lamination direction of the optical laminate was measured using a planar biaxial meter (manufactured by Mitutoyo Corporation). The sample was then placed in a humidifying oven at 65°C and 90% RH (relative humidity) for 48 hours. The sample was then removed from the humidifying oven and positioned in the same manner as above, and the distance (height) between the outer edge and the center of the sample in the stacking direction of the optical laminate was measured as described above. The measurement results were evaluated according to the following criteria. The results are shown in Table 1. ◯: Less than the glass warpage of Comparative Example 1 ×: The amount of glass warpage is equal to or greater than that of Comparative Example 1

[0065] [Preparation Example 1: Preparation of polarizing plate] A long, amorphous isophthalic copolymerized polyethylene terephthalate film (thickness: 100 μm) having a Tg of about 75° C. was used as the thermoplastic resin substrate, and one side of the resin substrate was subjected to a corona treatment. A PVA aqueous solution (coating liquid) was prepared by dissolving 100 parts by mass of a PVA-based resin prepared by mixing polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "GOHSEFFIMER") in a 9:1 ratio, to which 13 parts by mass of potassium iodide was added, in water. The above PVA aqueous solution was applied to the corona treated surface of the resin substrate and dried at 60° C. to form a PVA resin layer with a thickness of 13 μm, thereby producing a laminate. The resulting laminate was uniaxially stretched 2.4 times in the machine direction (longitudinal direction) in an oven at 130°C (auxiliary in-air stretching treatment). Next, the laminate was immersed in an insolubilizing bath (a boric acid aqueous solution obtained by mixing 4 parts by mass of boric acid with 100 parts by mass of water) at a liquid temperature of 40°C for 30 seconds (insolubilizing treatment). Next, the film was immersed in a dye bath (an aqueous iodine solution obtained by mixing iodine and potassium iodide in a weight ratio of 1:7 with 100 parts by mass of water) at a liquid temperature of 30°C for 60 seconds while adjusting the concentration so that the single transmittance (Ts) of the finally obtained polarizer would be a desired value (dyeing treatment). Next, the substrate was immersed in a crosslinking bath (a boric acid aqueous solution obtained by blending 3 parts by mass of potassium iodide and 5 parts by mass of boric acid with 100 parts by mass of water) at a liquid temperature of 40° C. for 30 seconds (crosslinking treatment). The laminate was then immersed in a boric acid aqueous solution (boric acid concentration 4 wt %, potassium iodide concentration 5 wt %) at a liquid temperature of 70°C and uniaxially stretched in the longitudinal direction (longitudinal direction) between rolls with different peripheral speeds to a total stretch ratio of 5.5 times (underwater stretching treatment). Thereafter, the laminate was immersed in a cleaning bath (aqueous solution obtained by mixing 4 parts by mass of potassium iodide with 100 parts by mass of water) at a liquid temperature of 20° C. (cleaning treatment). Thereafter, the film was dried in an oven maintained at about 90°C, and brought into contact with a heated roll made of SUS whose surface temperature was maintained at about 75°C (drying shrinkage treatment). In this manner, a polarizer having a thickness of about 5 μm was formed on the resin substrate, and a laminate having a resin substrate / polarizer structure was obtained. An acrylic resin film (product name: CAT film, thickness: 40 μm) was attached as a protective layer to the polarizer surface of the obtained laminate (the surface opposite to the resin substrate).The resin substrate was then peeled off to obtain a polarizing plate having a protective layer / polarizer configuration.

[0066] [Example 1] A brightness enhancement film (manufactured by 3M, product name "APF-V3," thickness 26 μm) was prepared. A first adhesive layer composed of an acrylic adhesive was provided on the surface of the brightness enhancement film. Thereafter, the protective layer of the polarizing plate obtained in Preparation Example 1 was brought into contact with the first adhesive layer, and the polarizing plate was attached to the brightness enhancement film so that the reflection axis of the brightness enhancement film and the absorption axis of the polarizer were substantially parallel. Next, a second adhesive layer made of an acrylic adhesive was provided on the surface of the brightness-enhancing film opposite the polarizing plate. A 40 μm-thick resin film (product name: TG40UL, manufactured by Fujifilm Corporation) was then brought into contact with the second adhesive layer, and the resin film was attached to the brightness-enhancing film. The resin film had a triacetyl cellulose (TAC) film (thickness: 40 μm) as a substrate and a hard coat (HC) layer (thickness: 7 μm) provided on the TAC film. Next, a third pressure-sensitive adhesive layer made of an acrylic pressure-sensitive adhesive was formed on the polarizer of the polarizing plate, and a release liner (a PET resin film provided with a release-treated layer) was attached to the surface of the third pressure-sensitive adhesive layer. As a result of the above, a raw film having a structure of resin film / second pressure-sensitive adhesive layer / brightness enhancing film / first pressure-sensitive adhesive layer / polarizing plate / third pressure-sensitive adhesive layer / release liner was obtained.

[0067] Next, laminate chips having the shape shown in Figure 2 were punched out from the raw film. The reflection axis of the brightness enhancement film and the absorption axis of the polarizer were each substantially perpendicular to the long side direction of the laminate chip. Table 1 shows the angles formed by the first direction in which the reflection axis extends (reflection axis direction) and the direction in which the absorption axis of the polarizer extends (absorption axis direction), respectively, with the long side direction of the laminate chip. The peripheral edge of the laminated chip had a first long side, a second long side, a first short side, and a second short side when viewed from the stacking direction. The laminated chip also had, as its specially shaped portion, a recess recessed inward (in the short side direction) from the center of the first long side, a first chamfered portion where the corner between the first long side and the first short side was chamfered, and a second chamfered portion where the corner between the first long side and the second short side was chamfered. That is, the recessed direction of the recessed portion was substantially parallel to the second direction in which the reflective axis of the brightness enhancement film extended. The angle formed between the recessed direction of the recessed portion and the second direction in which the reflective axis of the brightness enhancement film extended (the reflective axis direction) is shown in Table 1.

[0068] Thereafter, the outer peripheral surface of the obtained laminated chip was subjected to end face machining using an end mill.

[0069] As a result of the above, an optical laminate having a structure of resin film / second adhesive layer / brightness enhancement film / first adhesive layer / polarizing plate / third adhesive layer / release liner, and having irregularly shaped processed portions (recesses, first chamfered portions, and second chamfered portions), was obtained.

[0070] [Example 2] An optical laminate was obtained in the same manner as in Example 1, except that the 40 μm thick resin film (product name: TG40UL, manufactured by Fujifilm Corporation) was changed to a 25 μm thick resin film (product name: TJ25UL, manufactured by Fujifilm Corporation).

[0071] [Example 3] An optical laminate was obtained in the same manner as in Example 1, except that the resin film having a TAC film and an HC layer (product name: TG40UL, Fujifilm, thickness 40 μm) was changed to a resin film having an acrylic film (substrate) with a glutarimide structure and an HC layer.

[0072] [Example 4] An optical laminate was obtained in the same manner as in Example 1, except that the resin film having a TAC film and an HC layer (product name: TG40UL, manufactured by Fujifilm Corporation, thickness 40 μm) was changed to one having an HC layer formed on the resin film obtained by forming a film of thickness 60 μm using a polycarbonate (PC) resin (product name: DURABIO, manufactured by Mitsubishi Chemical Corporation).

[0073] [Example 5] An optical laminate was obtained in the same manner as in Example 1, except that the resin film having a TAC film and an HC layer (product name: TG40UL, manufactured by Fujifilm Corporation, thickness 40 μm) was changed to one having an HC layer formed on the resin film obtained by forming a 40 μm thick film using a polycarbonate (PC) resin (product name: DURABIO, manufactured by Mitsubishi Chemical Corporation).

[0074] [Example 6] An optical laminate having a structure of resin film / second adhesive layer / brightness enhancing film / first adhesive layer / polarizing plate / third adhesive layer / release liner was obtained in the same manner as in Example 1, except that the brightness enhancing film (manufactured by 3M, product name "APF-V3", thickness 26 μm) was changed to a brightness enhancing film (manufactured by 3M, product name "APF-T35", thickness 38 μm).

[0075] [Comparative Example 1] An optical laminate having a structure of brightness enhancement film / first adhesive layer / polarizing plate / third adhesive layer / release liner was obtained in the same manner as in Example 1, except that the brightness enhancement film (manufactured by 3M, product name "APF-V3", thickness 26 μm) was changed to a brightness enhancement film (manufactured by 3M, product name "APF-T35", thickness 38 μm) and that no resin film was attached to the brightness enhancement film.

[0076] Comparative Example 2 An optical laminate having a structure of brightness enhancement film / first adhesive layer / polarizing plate / third adhesive layer / release liner was obtained in the same manner as in Example 1, except that no resin film was attached to the brightness enhancement film.

[0077] [Reference example 1] An optical laminate was obtained in the same manner as in Comparative Example 1, except that laminate chips were punched out from the raw film so that the second direction in which the reflection axis of the brightness enhancement film extended and the recessed direction of the recesses were substantially perpendicular to each other.

[0078] [Table 1]

[0079] [evaluation] As is clear from Comparative Examples 1 and 2, if the recesses are recessed in the reflection axis direction of the brightness enhancement film, cracks may occur in the brightness enhancement film and the polarizer during the heat shock test. In this regard, as in the examples of the present application, if a resin film is attached to the brightness enhancement film on the side opposite the polarizing plate via a second adhesive layer, it is possible to suppress cracks from occurring in the brightness enhancement film and the polarizer during the heat shock test. In particular, it is clear that if the breaking strength of the brightness enhancement film is 150 MPa or more, cracks in the brightness enhancement film and the polarizer during the heat shock test can be stably suppressed. [Industrial Applicability]

[0080] The optical laminate according to the embodiment of the present invention can be used in various industrial products, and is particularly suitable for use in display devices such as liquid crystal display devices, organic EL display devices, and inorganic EL display devices. [Explanation of symbols]

[0081] 1 Brightness enhancement film 2 Polarizing Plate 21 Polarizer 22 Protective layer 3 Resin film

Claims

1. An optical laminate having a contoured processed portion, a brightness enhancement film that transmits polarized light having a specific polarization state and reflects light having other polarization states; a polarizing plate attached to the brightness enhancement film via a first adhesive layer; a resin film attached to the brightness enhancement film on the opposite side of the polarizing plate via a second adhesive layer, the polarizing plate includes a polarizer, the brightness enhancement film has a transmission axis extending in a first direction and a reflection axis extending in a second direction perpendicular to the first direction; The optical laminate, wherein the irregularly shaped portion includes a recess that is recessed inward in the second direction from a peripheral edge of the optical laminate when viewed from the stacking direction of the optical laminate.

2. The optical laminate according to claim 1 , wherein the polarizer has a thickness of 8 μm or less.

3. The optical laminate according to claim 1 , wherein the brightness enhancement film has a breaking strength in the second direction at 23° C. of 150 MPa or more.

4. The optical laminate according to claim 1 or 2, wherein the resin film has a thickness of 25 μm or more.

5. The optical laminate according to claim 1 , wherein the resin film has a breaking strength in the second direction at 23° C. of 85 MPa or more.

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