Layered optical film with adhesive layer and method for manufacturing the same

Abstract

[Project] The objective is to provide an optical laminate film with an adhesive layer attached that suppresses the occurrence of cracks. [Solution] An optical laminated film comprising a polarizer layer in which a dichroic pigment is adsorbed and oriented, and an adhesive layer attached to the optical laminated film, wherein at least a portion of the side of the adhesive layer attached to the optical laminated film is a protective region in which the adhesive layer protrudes outwardly from the shortest position of the polarizer layer and is folded up toward the polarizer layer.

Description

Technology Field

[0001] The present invention relates to an optical laminate film with an adhesive layer attached and a method for manufacturing the same. Background Technology

[0002] Recently, the design capabilities of image display devices have become more diverse. Influenced by this trend, there is a demand for optical laminated films, including linear polarizing films, to accommodate various shapes. Japanese Patent Publication No. 2018-25630 discloses a polarizing plate having a concave portion on its outer edge and a polarizing plate having a through hole within its plane. Prior art literature

[0003] Patent Document 1: Japanese Patent Publication No. 2018-25630 The problem to be solved

[0004] Optical laminated films with a shape having a concave portion on the outer edge and optical laminated films with a shape having a through hole within the plane have a problem in that they are prone to cracking.

[0005] The present invention aims to provide an optical laminate film with an adhesive layer attached that suppresses the occurrence of cracks, and a method for manufacturing the same. means of solving the problem

[0006] The present invention provides the following optical laminated film with an adhesive layer attached and a method for manufacturing the optical laminated film with an adhesive layer attached.

[0007] [1] An optical laminated film comprising a polarizer layer in which a dichroic pigment is adsorbed and oriented, and an adhesive layer attached to the optical laminated film, wherein the adhesive layer is attached in sequence,

[0008] An optical laminate film with an adhesive layer attached, wherein at least a portion of the side of the optical laminate film with the adhesive layer attached is a protective region in which the adhesive layer protrudes outwardly from the shortest position of the polarizer layer and is folded up toward the polarizer layer.

[0009] [2] At least a portion of the side of the optical laminate film with the adhesive layer attached is a curved region in which the contour on the surface opposite to the adhesive layer side of the optical laminate film is curved, and

[0010] At least a portion of the above-mentioned curved surface area is an optical laminate film with an adhesive layer attached, as described in [1], which is the above-mentioned protective area.

[0011] [3] The protective region in the curved region is an optical laminate film with an adhesive layer attached as described in [2], wherein the angle θ formed by the contour with respect to the absorption axis direction of the polarizer layer changes continuously, and the angle θ is greater than 0° and less than or equal to 90°.

[0012] [4] An optical laminate film with an adhesive layer attached, as described in any one of [1] to [3], wherein the above-mentioned protective area is a cut surface.

[0013] [5] An optical laminate film with an adhesive layer attached as described in any one of [1] to [4], wherein the protective region comprises a region in which the distance d formed by the shortest position of the adhesive layer and the shortest position of the polarizer layer is 10 μm or more.

[0014] [6] An optical laminate film with an adhesive layer attached as described in any one of [1] to [5], having a peelable separator film further bonded to the surface opposite to the side of the optical laminate film of the adhesive layer.

[0015] [7] The optical laminate film described above is an optical laminate film with an adhesive layer attached, comprising a liquid crystal curing layer made of a polymerized cured product of a polymerizable liquid crystal compound, as described in any one of [1] to [6].

[0016] [8] The optical laminated film includes a protective layer on the side opposite to the adhesive layer when viewed from the polarizer layer, and

[0017] The above protective layer is an optical laminate film with an adhesive layer attached as described in any one of claims [1] to [7], comprising a hard coating layer constituting a surface opposite to the polarizer layer side.

[0018] [9] A process for preparing a laminated film having, in this order, an optical laminated film comprising a polarizer layer in which a dichroic pigment is adsorbed and oriented, an adhesive layer, and a separate film peelably bonded to the adhesive layer, and

[0019] A method for manufacturing an optical laminate film with an adhesive layer attached, comprising a cutting process in which an etching blade is introduced from the side of the separator film into the laminated film to cut the laminated film and form a side.

[0020]

[10] A method for manufacturing an optical laminate film with an adhesive layer attached, as described in [9], wherein at least a portion of the above-mentioned side is a protective region in which the adhesive layer protrudes outward from the shortest position of the polarizer layer and is folded up toward the polarizer layer. Effects of the invention

[0021] According to the present invention, an optical laminate film with an adhesive layer attached, in which the occurrence of cracks is suppressed, can be provided. Brief explanation of the drawing

[0022] FIG. 1 is a schematic cross-sectional view schematically illustrating an example of an optical laminate film with an adhesive layer attached according to the present invention. FIG. 2 is a top view showing an example of an optical laminate film with an adhesive layer attached having a curved area on the side. FIG. 3 is a top view showing another example of an optical laminate film with an adhesive layer attached having a curved area on the side. FIG. 4 is a schematic cross-sectional view schematically showing an optical laminate film with an adhesive layer attached according to a first embodiment. FIG. 5 is a schematic cross-sectional view schematically showing an optical laminate film with an adhesive layer attached according to a second embodiment. Figure 6 is a top view showing an example of an etching blade type. Figure 7 shows a cross-sectional view of the corrosion blade shown in Figure 6. FIG. 8 is a cross-sectional view schematically illustrating a cutting process related to the manufacturing method of the present invention. FIG. 9 is a cross-sectional view schematically showing an example of the cross-sectional shape of an etching blade. FIG. 10 is a cross-sectional view schematically showing an example of the cross-sectional shape of an etching blade. FIG. 11 is a cross-sectional view schematically showing an example of the cross-sectional shape of an etching blade. FIG. 12 is a cross-sectional view schematically showing an observation image of cross-sections of optical laminated films A and B with adhesive layers attached, observed by optical microscope images. FIG. 13 is a cross-sectional view schematically showing an observation image of the cross-section of optical laminated films C and D with adhesive layers attached, observed by optical microscope image. Figure 14 is an optical microscope image showing the upper surface of optical laminated films A and B with adhesive layers attached. Figure 15 is a schematic diagram showing the method of measuring indentation force. Figure 16 is a diagram showing the measurement results of the indentation force. Specific details for implementing the invention

[0023] [Adhesive Layer Attached Optical Laminated Film]

[0024] FIG. 1 is a schematic cross-sectional view schematically illustrating an example of an optical laminate film with an adhesive layer attached according to the present invention. As shown in FIG. 1, the optical laminate film (100) with an adhesive layer attached comprises, in sequence, an optical laminate film (20) comprising a polarizer layer (21) in which a dichroic pigment is adsorbed and oriented, and an adhesive layer (31).

[0025] At least a portion of the side of the optical laminate film (100) with the adhesive layer attached is a protected area. In this specification, "protected area" refers to a side area in which the adhesive layer (31) protrudes outward from the shortest position of the polarizer layer (21) and is also folded up toward the polarizer layer (21). Regarding the scope of the "side area" in this specification, all positions arranged in the lamination direction on the side are considered to be included in the same area. In this specification, "folded up toward the polarizer layer (21)" means that the protruding portion of the adhesive layer (31) has a portion that is closer to the polarizer layer (21) compared to other portions. The protruding portion of the adhesive layer (31) is close to the polarizer layer (21), so that the adhesive layer (31) may be in contact with the entire side of the polarizer layer (21) or a part of the side of the polarizer layer (21), or as shown in FIG. 1, the adhesive layer (31) may be curved toward the polarizer layer (21) without contacting the side of the polarizer layer (21). The side area (100a) shown in FIG. 1 is a protective area.

[0026] The optical laminate film (100) with an adhesive layer attached can suppress the occurrence of cracks by having a protective area (100a) on its side. It is presumed that the occurrence of cracks is suppressed because the side of the optical laminate film (20) is protected by the adhesive layer (31) in the protective area (100a). Cracks are prone to occur starting from the side or near the side.

[0027] For the side of the optical laminate film (100) with the adhesive layer attached, at least a portion of the area may be a protected area (100a), but from the perspective of suppressing crack occurrence, it is preferable for the proportion of the area that is the protected area (100a) to be higher. Alternatively, it is preferable for the side area prone to crack occurrence to be the protected area (100a). For example, at least 10% of the total area of ​​the side of the optical laminate film (100) with the adhesive layer attached is the protected area (100a). Or, for example, at least a portion of the curved area of ​​the side of the optical laminate film (100) with the adhesive layer attached includes the protected area (100a), and at least 50% of the total area of ​​the curved area is the protected area (100a).

[0028] In this specification, the term "curved area" refers to a side area on the surface (20a) opposite to the adhesive layer (31) side of the optical laminated film (20) where the contour is curved. The term "curved" here means that the angle θ formed with the absorption axis direction of the polarizer layer (21) changes continuously. In the curved area, cracks are prone to occur starting from the side or near the side.

[0029] FIG. 2 is a top view showing an example of an adhesive layer optical laminate film having a curved area on its side. FIG. 2 is a top view of the adhesive layer-attached optical laminate film (110) seen from a surface opposite to the adhesive layer side. The adhesive layer-attached optical laminate film (110) shown in FIG. 2 is a square with rounded corners and has a through hole (51). A square with rounded corners refers to a shape in which one or more of the corners of the square are curved, that is, one or more of the corners of the square are rounded. The adhesive layer-attached optical laminate film (110) has all corners (52) rounded. The adhesive layer-attached optical laminate film (110) shown in FIG. 2 has a curved area on the inner wall of the through hole (51) and the side of the corner (52). The contour of the curved area has an angle θ formed with the absorption axis direction of the polarizer layer that changes continuously.

[0030] FIG. 3 is a top view showing another example of an optical laminate film with an adhesive layer attached having a curved area on its side. FIG. 3 is a top view of the optical laminate film with an adhesive layer attached (120) seen from a surface opposite to the adhesive layer side. The optical laminate film with an adhesive layer attached (120) shown in FIG. 3 is a square with rounded corners and has a concave portion (53) on its outer edge. The optical laminate film with an adhesive layer attached (120) shown in FIG. 3 has a curved area on the side of the concave portion (53) and the corner portion (52) on its outer edge. The contour of the curved area has a continuously changing angle θ formed with the absorption axis of the polarizer layer.

[0031] The optical laminate film with the adhesive layer attached may be a square with rounded corners as shown in FIGS. 2 and 3 when viewed in planar view, or it may be a square. A square refers to a shape in which all four corners are not rounded. In addition, in this specification, a square refers to a rectangular shape or a square.

[0032] The contour of the side on the surface (20a) is such that the angle θ formed with the absorption axis direction of the polarizer layer (31) is 0° to 90°, and the region where the angle θ changes continuously is a curved region. The curved region includes a portion where the angle θ is greater than 0° and less than or equal to 90°. This is because the curved region including such portion is prone to cracks starting from the side or the vicinity of the side, and thus the crack suppression effect according to the present invention becomes more pronounced.

[0033] FIG. 1 shows the distance d formed between the shortest position of the adhesive layer (31) and the shortest position of the polarizer layer (21) in the protection area (100a) of the optical laminate film (100) with the adhesive layer attached. The protection area (100a) preferably includes an area where the distance d is 10 μm or more, and more preferably includes an area where the distance d is 15 μm or more. In such an area, it becomes easier to suppress the occurrence of cracks. In the protection area (100a), the distance d formed between the shortest position of the adhesive layer (31) and the shortest position of the polarizer layer (21) is, for example, 30 μm or less.

[0034] In an optical laminate film (100) with an adhesive layer attached, the side having a protective region (100a) is, for example, a cut surface formed by cutting the laminate with a cutting blade. By adjusting the cutting blade used for cutting, the cutting direction, the cutting speed, and the in-plane tension applied to the laminate during cutting, a side having a protective region can be formed in which the adhesive layer (31) protrudes outward from the shortest position of the polarizer layer (21) and is folded up toward the polarizer layer (21). If an etching blade (pinnacle blade) with a tip formed by etching is used as the cutting blade, the adhesive layer (31) protrudes and is folded up to form the protective region (100a). In addition, the protective region (100a) can be formed in the same way even if the cutting speed, that is, the entry speed when the cutting blade enters the laminate, is increased. The protective region (100a) can be formed by increasing the in-plane tension applied to the laminate. To increase in-plane tension, for example, the pressure holding the laminate together during cutting must be increased.

[0035] The adhesive layer (31) is used as an adhesive layer for bonding, for example, an optical laminate film (20) to an image display element such as a liquid crystal cell, an organic EL display element, or other optical components. The optical laminate film (100) with the adhesive layer attached may have a peelable separator film bonded to a surface opposite to the side of the optical laminate film (20) of the adhesive layer (31).

[0036] The optical laminate film (20) may include a different layer separate from the polarizer layer (21), and other layers may include a protective layer, a liquid crystal curing layer, a phase difference layer, a bonding layer, etc. The optical laminate film (20) may have a protective layer on the side opposite to the adhesive layer (31) when viewed from the polarizer layer (31), and this protective layer may include a hard coating layer constituting the surface opposite to the polarizer layer (21).

[0037] <First Embodiment>

[0038] FIG. 4 is a schematic cross-sectional view schematically illustrating an optical laminate film with an adhesive layer attached according to a first embodiment. As shown in FIG. 4, the optical laminate film (130) with an adhesive layer attached has an optical laminate film (20) and an adhesive layer (31) in sequence, and further has a separator film (32) peelably bonded to the surface of the adhesive layer (31) on the side opposite to the optical laminate film (20).

[0039] The optical laminated film (20) has a surface protection film (24), a first protection layer (22), a polarizer layer (21), and a second protection layer (23) in this order. The first protection layer (22) has a hard coating layer constituting a surface opposite to the adhesive layer (31) side, and the surface protection film (24) is peelably bonded to the surface of the hard coating layer.

[0040] In the optical laminate film (130) with an adhesive layer attached, the side region (130a) shown in FIG. 4 is a protective region. In the protective region (130a), the adhesive layer (31) protrudes outward from the shortest position of the polarizer layer (21) and is folded up toward the polarizer layer (21).

[0041] <Second Embodiment>

[0042] FIG. 5 is a schematic cross-sectional view schematically illustrating an optical laminate film with an adhesive layer attached according to a second embodiment. As shown in FIG. 5, the optical laminate film (140) with an adhesive layer attached has an optical laminate film (20) and an adhesive layer (31) in sequence, and further has a separator film (32) peelably bonded to the surface of the adhesive layer (31) on the side opposite to the optical laminate film (20).

[0043] The optical laminated film (20) has a surface protection film (24), a first protection layer (22), a polarizer layer (21), a second protection layer (23), a first bonding layer (25), a first liquid crystal curing layer (26), a second bonding layer (27), and a second liquid crystal curing layer (28) in this order. The first protection layer (22) has a hard coating layer constituting a surface opposite to the adhesive layer (31) side, and the surface protection film (24) is peelably bonded to the surface of the hard coating layer.

[0044] In the optical laminate film (140) with an adhesive layer attached, the side region (140a) shown in FIG. 5 is a protective region. In the protective region (140a), the adhesive layer (31) protrudes outward from the shortest position of the polarizer layer (21) and is folded up toward the polarizer layer (21).

[0045] In the protective region (140a) of the optical laminate film (140) with the adhesive layer attached, regarding the other layer other than the adhesive layer (31), it may protrude outwardly from the shortest position of the polarizer layer (21) just like the adhesive layer (31), and may also have a shape that is folded up toward the polarizer layer (21). FIG. 5 shows a case in which, in the protective region (140a), in addition to the adhesive layer (31), the first bonding layer (25), the first liquid crystal curing layer (26), and the second liquid crystal curing layer (28) protrude outwardly from the shortest position of the polarizer layer (21) just like the adhesive layer (31) and have a shape that is folded up toward the polarizer layer (21). In the cutting side, in the layer where the indentation of the indentation force measured by the test method of the embodiment described later is 50 g / mm or less, the behavior when a cutting blade is inserted is similar to that of the adhesive layer (31), so it is presumed that it is likely to protrude outward from the shortest position of the polarizer layer (21) and also bend upward toward the polarizer layer (21), just like the adhesive layer (31).

[0046] The optical laminate film with an adhesive layer attached according to the present invention may include a layer having an indentation of 50 g / mm or less.

[0047] Below, the materials of each layer constituting the optical laminate film with the adhesive layer attached will be described in detail.

[0048] (Optical laminated film (20))

[0049] The optical laminate film (20) includes a polarizer layer (21). The thickness of the optical laminate film (20) can typically be 5 μm or more and 200 μm or less, and may be 150 μm or less and 120 μm or less.

[0050] (Polarizer layer (21))

[0051] Examples of the polarizer layer (21) include a stretched film or stretched layer in which a pigment having absorption anisotropy is adsorbed, or a layer formed by applying and curing a pigment having absorption anisotropy. Examples of pigments having absorption anisotropy include dichroic pigments. Specifically, iodine or dichroic organic dyes are used as dichroic pigments. Dichroic organic dyes include dichroic direct dyes composed of disazo compounds such as CI DIRECT RED 39, and dichroic direct dyes composed of compounds such as trisazo and tetrakisazo.

[0052] The thickness of the polarizer layer (21) is, for example, 2 μm or more and 40 μm or less. The thickness of the polarizer layer may be 5 μm or more, 20 μm or less, further 15 μm or less, and further 10 μm or less.

[0053] (1) Polarizer layer which is a stretched film or stretched layer

[0054] Examples of polarizer layers formed by applying and curing a pigment having absorption anisotropy include a polarizer layer comprising a cured product of a polymerizable liquid crystal compound, such as a layer obtained by applying and curing a composition containing a dichroic pigment having liquid crystal properties or a composition containing a dichroic pigment and a polymerizable liquid crystal. A polarizer layer formed by applying and curing a pigment having absorption anisotropy is preferred because, compared to a stretched film or stretched layer adsorbed with a pigment having absorption anisotropy, there is no restriction on the bending direction.

[0055] A polarizer layer, which is a stretched film adsorbing a pigment having absorption anisotropy, can be manufactured by a process of uniaxially stretching a polyvinyl alcohol-based resin film, a process of adsorbing the dichroic pigment by dyeing the polyvinyl alcohol-based resin film with a dichroic pigment, a process of treating the polyvinyl alcohol-based resin film with the adsorbed dichroic pigment with an aqueous boric acid solution, and a process of washing with water after treatment with the aqueous boric acid solution.

[0056] Polyvinyl alcohol-based resins are obtained by saponifying polyvinyl acetate-based resins. As polyvinyl acetate-based resins, in addition to polyvinyl acetate, which is a homopolymer of vinyl acetate, copolymers of vinyl acetate and other monomers copolymerizable thereto are used. 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.

[0057] The degree of saponification of the polyvinyl alcohol-based resin is typically 85 mol% or more and 100 mol% or less, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The degree of polymerization of the polyvinyl alcohol-based resin is typically 1,000 or more and 10,000 or less, preferably 1,500 or more and 5,000 or less.

[0058] A polarizer layer, which is an extended layer adsorbing a pigment having absorption anisotropy, can be manufactured by typically applying a coating solution containing the above-mentioned polyvinyl alcohol-based resin onto a base film, uniaxially stretching the obtained laminated film, dyeing the polyvinyl alcohol-based resin layer of the uniaxially stretched laminated film with a dichroic pigment to adsorb the dichroic pigment and form it into a polarizer layer, treating the film with the adsorbed dichroic pigment with an aqueous boric acid solution, and washing with water after treatment with the aqueous boric acid solution. If necessary, the base film may be peeled off from the polarizer layer. The material of the base film is exemplified as the same material as the base film of the surface protection film (24) described later.

[0059] (2) A polarizer layer formed by applying and curing a pigment having absorption anisotropy.

[0060] As a polarizer layer formed by applying and curing a pigment having absorption anisotropy, examples include a polarizer layer comprising a cured product of a polymerizable liquid crystal compound, such as a layer obtained by applying and curing a composition containing a polymerizable dichroic pigment having liquid crystal properties or a composition containing a dichroic pigment and a polymerizable liquid crystal to a base film. If necessary, the base film may be peeled off from the polarizer layer. The material of the base film is exemplified as the same material as the base film of the surface protection film (24) described later.

[0061] (1st protective layer (22), 2nd protective layer (23))

[0062] The optical laminated film (20) may include a first protective layer (22) laminated on a surface opposite to the adhesive layer (31) side of the polarizer layer (21), and may also include a second protective layer (23) laminated on the adhesive layer (31) side of the polarizer layer (21). The first protective layer (22) and the second protective layer (23) may be an optically transparent thermoplastic resin, such as a polyolefin resin (e.g., polypropylene resin), a cyclic polyolefin resin (e.g., norbornene resin); a cellulose resin (e.g., triacetylcellulose, diacetylcellulose); a polyester resin (e.g., polyethylene terephthalate, polybutylene terephthalate); a polycarbonate resin; a (meth)acrylic resin (e.g., methyl methacrylate resin); a polystyrene resin; a polyvinyl chloride resin; The coating layer or film may be composed of an acrylonitrile-butadiene-styrene resin; an acrylonitrile-styrene resin; a polyvinyl acetate resin; a polyvinylidene chloride resin; a polyamide resin; a polyacetal resin; a modified polyphenylene ether resin; a polysulfone resin; a polyethersulfone resin; a polyarylate resin; a polyamideimide resin; a polyimide resin; or one or more of these. The thickness of the protective layer is typically 1 μm or more and 100 μm or less, but may be 5 μm or more and 80 μm or less, 60 μm or less, or 50 μm or less.

[0063] The protective film can be bonded to the polarizer layer (21), for example, through an adhesive layer. Examples of adhesives forming the adhesive layer include water-based adhesives, active energy beam curable adhesives, or thermosetting adhesives, and it is preferable to use water-based adhesives or active energy beam curable adhesives.

[0064] Two opposing surfaces bonded through an adhesive layer may be subjected to corona treatment, plasma treatment, flame treatment, etc. beforehand, or may have a primer layer, etc.

[0065] The first protective layer (22) and the second protective layer (23) may be protective layers made of the same material or protective layers made of different materials. The first protective layer (22) may have an optical functional layer such as an anti-glare layer, a light diffusion layer, a phase difference layer, or an anti-reflection layer, or a surface treatment layer such as a hard coating layer, an antistatic layer, or an anti-fouling layer on its surface. When the first protective layer (22) has a hard coating layer, cracks are prone to occur, but according to the present invention, even with such a configuration, the occurrence of cracks can be suppressed.

[0066] (Surface protection film (24))

[0067] The optical laminate film (20) may include a surface protection film (24) that forms a surface opposite to the surface on the adhesive layer (31) side. The surface protection film (24) is peeled off for each adhesive layer after the optical laminate film with the adhesive layer attached is bonded to, for example, an image display element or other optical member.

[0068] The surface protection film (24) has a base film and an adhesive layer. The thickness of the surface protection film (24) is, for example, 15 μm or more and 100 μm or less, preferably 20 μm or more and 80 μm or less, and more preferably 30 μm or more and 60 μm or less.

[0069] The resin forming the base film may be a thermoplastic resin such as a chain-type polyolefin resin like polyethylene or polypropylene; a cyclic polyolefin resin like norbornene resin; a polyester resin like polyethylene terephthalate or polyethylene sodium phthalate; a polycarbonate resin; or a mixture of one or more of these. The base layer may have a single-layer structure or a multi-layer structure, but is preferably a single-layer structure from the perspective of ease of manufacturing and manufacturing cost. The base layer may be a uniaxially stretched film or a biaxially stretched film, but is preferably a biaxially stretched film from the perspective of the mechanical strength of the film, ease of manufacturing, and manufacturing cost.

[0070] The adhesive layer may be composed of an adhesive composition having resins such as (meth)acrylic, rubber, urethane, ester, silicone, or polyvinyl ether resins as the main component. Among these, an adhesive composition having (meth)acrylic resin as the base polymer, which has excellent transparency, weather resistance, and heat resistance, is suitable. The adhesive composition may be of the active energy beam curing type or the thermosetting type.

[0071] (First liquid crystal curing layer (26), second liquid crystal curing layer (28))

[0072] The optical laminate film (20) may include a liquid crystal curing layer composed of one or more polymerized cured products of a polymerizable liquid crystal compound. The optical laminate film (140) with a bonding layer attached according to the second embodiment includes a first liquid crystal curing layer (26) and a second liquid crystal curing layer (28) as liquid crystal curing layers. The liquid crystal curing layer may, for example, function as a phase difference layer. The liquid crystal curing layer may be formed by applying a composition containing a polymerizable liquid crystal compound to a base film and curing it. An alignment layer may be formed between the base film and the coating layer. The liquid crystal curing layer may be inserted into the optical laminate film (20) in a form having an alignment layer and / or a base film.

[0073] The liquid crystal curing layer can be formed using a known polymerizable liquid crystal compound. The type of liquid crystal compound is not particularly limited, and rod-shaped liquid crystal compounds, disc-shaped liquid crystal compounds, and mixtures thereof may be used. Examples of polymerizable liquid crystal compounds include the polymerizable liquid crystal compounds described in Japanese Patent Publication No. Hei 11-513019, Japanese Patent Publication No. 2005-289980, Japanese Patent Publication No. 2007-108732, Japanese Patent Publication No. 2010-244038, Japanese Patent Publication No. 2010-31223, Japanese Patent Publication No. 2010-270108, Japanese Patent Publication No. 2011-6360, Japanese Patent Publication No. 2011-207765, Japanese Patent Publication No. 2016-81035, International Publication No. 2017 / 043438 and Japanese Patent Publication No. 2011-207765.

[0074] For example, a liquid crystal curing layer can be formed by applying a composition containing a polymerizable liquid crystal compound onto an orientation layer to form a film, and then curing the film. The thickness of the liquid crystal curing layer is preferably 0.5 μm to 10 μm, and more preferably 0.5 μm to 5 μm.

[0075] A composition containing a polymerizable liquid crystal compound may include, in addition to the polymerizable liquid crystal compound, a polymerization initiator, a polymerizable monomer, a surfactant, a solvent, an adhesion improver, a plasticizer, an orientation agent, etc. Known methods such as die coating may be used as a method for applying the composition containing the polymerizable liquid crystal compound. Known methods such as irradiating with active energy rays (e.g., ultraviolet rays) may be used as a method for curing the composition containing the polymerizable liquid crystal compound.

[0076] (First bonding layer (25), second bonding layer (27))

[0077] In the optical laminated film (20), a bonding layer for bonding two layers may be included. The optical laminated film (140) with a bonding layer attached according to the second embodiment includes a first bonding layer (25) and a second bonding layer (27) as bonding layers. Examples of bonding layers include an adhesive layer, a pressure-sensitive adhesive layer, etc. For the adhesive layer, a water-based adhesive, an active energy beam curable adhesive, or a thermosetting adhesive is used. For the pressure-sensitive adhesive layer, the description of the pressure-sensitive adhesive layer formed on the surface protection film (24) applies.

[0078] The two opposing surfaces bonded through the bonding layer may be pre-treated with corona treatment, plasma treatment, flame treatment, etc., or may have a primer layer, etc.

[0079] (Phase difference layer)

[0080] The optical laminated film (20) may include one or more phase difference layers. As previously mentioned, the phase difference layer may be a liquid crystal cured layer or a resin film. Examples of the phase difference layer include positive A plates and positive C plates, such as λ / 4 plates or λ / 2 plates.

[0081] <Adhesive layer (31)>

[0082] The adhesive layer (31) may be composed of an adhesive composition having a resin as the main component, such as (meth)acrylic, rubber, urethane, ester, silicone, or polyvinyl ether resins. Among these, an adhesive composition having a (meth)acrylic resin as the base polymer, which has excellent transparency, weather resistance, and heat resistance, is suitable. The adhesive composition may be an active energy beam curing type or a heat curing type.

[0083] As a (meth)acrylic resin (base polymer) used in an adhesive composition, a polymer or copolymer having one or more types of (meth)acrylic acid esters, such as butyl (meth)acrylate, ethyl (meth)acrylate, isooctyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate, as monomers is suitably used. It is preferable to copolymerize a polar monomer into the base polymer. Examples of polar monomers include monomers having carboxyl groups, hydroxyl groups, amide groups, amino groups, epoxy groups, etc., such as (meth)acrylic acid, 2-hydroxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate, (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylate, and glycidyl (meth)acrylate.

[0084] The adhesive composition may comprise only the base polymer, but typically further comprises a crosslinking agent. Examples of crosslinking agents include: a metal ion with a divalent or higher valence that forms a metal carboxylate salt with a carboxyl group; a polyamine compound that forms an amide bond with a carboxyl group; a polyepoxy compound or a polyol that forms an ester bond with a carboxyl group; and a polyisocyanate compound that forms an amide bond with a carboxyl group. Among these, a polyisocyanate compound is preferred.

[0085] An active energy beam curable adhesive composition is an adhesive composition that has the property of curing upon irradiation with active energy beams, such as ultraviolet rays or electron beams, and possesses adhesive properties even before irradiation with active energy beams, allowing it to adhere to substrates such as films, and has the property of curing upon irradiation with active energy beams to adjust the adhesion strength. It is preferable that the active energy beam curable adhesive composition be of the ultraviolet curable type. The active energy beam curable adhesive composition further contains an active energy beam polymerizable compound in addition to a base polymer and a crosslinking agent. Additionally, if necessary, a photopolymerization initiator or a photosensitizer may be included.

[0086] The adhesive composition may include additives such as fine particles for imparting light scattering properties, beads (resin beads, glass beads, etc.), glass fibers, resins other than base polymers, tackifiers, fillers (metal powders or other inorganic powders, etc.), antioxidants, ultraviolet absorbers, dyes, pigments, colorants, defoaming agents, corrosion inhibitors, photopolymerization initiators, etc.

[0087] The formation of the adhesive layer (31) on the optical laminate film (20) can be performed by, for example, by preparing an adhesive liquid by dissolving or dispersing an adhesive composition in an organic solvent such as toluene or ethyl acetate and directly coating the adhesive liquid onto the target surface of a polarizing plate to form the adhesive layer (31), or by forming the adhesive layer (31) in a sheet form on a release-treated separator film and transferring it to the target surface of the optical laminate film (20). The adhesive layer (31) can be formed by applying an organic solvent diluted solution of the adhesive composition onto a substrate and drying it. When an active energy beam curing type adhesive composition is used, the formed adhesive layer (31) can be made into a cured material having a desired degree of curing by irradiating the formed adhesive layer (31) with an active energy beam.

[0088] The thickness of the adhesive layer (31) is determined according to its adhesive strength, etc., but a range of 1 μm or more and 50 μm or less is suitable, and preferably 2 μm or more and 40 μm or less.

[0089] The adhesive layer (31) has a storage modulus of typically 1 MPa or less, preferably 0.15 MPa or less, measured at a temperature of 20°C and an angular frequency of 100 rad / s. The storage modulus of the adhesive is typically 0.001 MPa or more, preferably 0.01 MPa or more.

[0090] <Separate film (32)>

[0091] The optical laminate film with an adhesive layer attached may include a separator film (32) formed on the surface of the adhesive layer (31). The separator film (32) may be a film composed of a polyethylene-based resin such as polyethylene, a polypropylene-based resin such as polypropylene, a polyester-based resin such as polyethylene terephthalate, etc. Among these, a stretched film of polyethylene terephthalate is preferred. The separator film (32) is peeled off, and the optical laminate film (20) is bonded to the substrate through the adhesive layer (31).

[0092] [Method for manufacturing an optical laminate film with an adhesive layer attached]

[0093] The method for manufacturing an optical laminate film with an adhesive layer attached according to the present invention comprises a process of preparing a base laminate film having, in this order, an optical laminate film including a polarizer layer (21) in which a dichroic pigment is adsorbed and oriented, an adhesive layer, and a separator film peelably bonded to the adhesive layer, and a cutting process of cutting the base laminate film by introducing an etching blade from the separator film side into the base laminate film to form a side. An example of an optical laminate film with an adhesive layer attached obtained by this manufacturing method is the aforementioned optical laminate film with a protective area on its side.

[0094] FIG. 6 is a top view showing an example of an etching blade type having an etching blade used in a cutting process in a method for manufacturing an optical laminate film (120) with an adhesive layer attached as shown in FIG. 3. The etching blade type (121) is a shape in which an etching blade formed by etching a metal plate is protruded in three dimensions, and the outline (122) shown in FIG. 6 represents the tip of the etching blade and matches the outline of the optical laminate film (120) with an adhesive layer attached.

[0095] By pressing the etching blade (121) against the laminated film and inserting the etching blade (122) into the laminated film to cut it, a side surface is formed and an optical laminated film (120) with an adhesive layer attached is punched. The laminated film to be punched may consist of multiple layers. It is preferable to have only one layer, as this improves the dimensional accuracy of the polarizing plate obtained. With this etching blade (121), six optical laminated films with adhesive layers attached can be produced simultaneously per laminated film by a single punching operation. The side surface of the optical laminated film (120) with an adhesive layer attached produced in this way is a cut surface.

[0096] The etching blade shape (121) is manufactured by patterning the resist film by laser irradiation and etching. Because of this, a blade shape with high dimensional accuracy is obtained. On the other hand, since it is manufactured by etching, the blade tip is not relatively sharp. The etching blade is also called a pinnacle blade. In contrast, the Thomson blade is manufactured by mechanical polishing, so the blade tip is relatively sharp. It is speculated that the reason an optical laminate film with an adhesive layer attached having a protective area on the side is obtained by the manufacturing method of the present invention is that when cutting, the pinnacle blade, which is an etching blade, is used, and compared to the case where the Thomson blade, which has a relatively sharp blade tip, is used, force is easily applied in the layer direction of the adhesive layer (31), and by this, a protrusion is formed on the adhesive layer (31), and by introducing the pinnacle blade from the side of the separator film (32), the protrusion is easily bent upward toward the polarizer layer (21).

[0097] FIG. 7 shows a cross-sectional view of an etching blade (122). The etching blade (122) consists of a blade tip (122a) and a body (122b). The angle β of the blade tip (122a) is preferably 20° to 40°, and more preferably 25° to 35°. The thickness t of the body (122b) is preferably 0.1 mm to 1 mm, and more preferably 0.2 mm to 0.6 mm.

[0098] FIG. 8 is a cross-sectional view schematically illustrating a cutting process using an etching blade (122). As shown in FIG. 8, a fabric laminate film (150) is placed on a butt plate (160). At this time, one fabric laminate film (150) is placed in a direction such that the optical laminate film (20) of the fabric laminate film (150) is positioned toward the butt plate (160), and the separator film (32) is positioned toward the side furthest from the butt plate (160). Multiple fabric laminate films (150) may be stacked and arranged, and multiple films may be punched simultaneously. Then, the etching blade (122) is introduced into the fabric laminate film (150) from the separator film (32) side. When the etching blade (122) reaches the butt plate (160), the etching blade (122) is removed from the fabric laminate film (150), and the punching is completed.

[0099] FIGS. 9 to 11 are cross-sectional views schematically illustrating examples of cross-sectional shapes of an etching blade (122). As shown in FIG. 9, the etching blade (122) may be a so-called double blade in which the side that becomes the optical laminate film with the adhesive layer attached after cutting (hereinafter referred to as "Side A") and the opposite side (hereinafter referred to as "Side B") are both inclined with respect to the perpendicular line (entry direction). As shown in FIG. 10, the etching blade (122) may be a so-called single blade in which Side A is parallel to the perpendicular line (entry direction) and only Side B is inclined with respect to the perpendicular line (entry direction). As shown in FIG. 11, the etching blade (122) may be a double blade in which the angle of inclination of Side A with respect to the perpendicular line (entry direction) and the angle of inclination of Side B with respect to the perpendicular line (entry direction) are different.

[0100] It is preferable that the angle α1 with respect to the perpendicular direction (entry direction) of the A side of the etching blade (122) is 0° to 20°. It is preferable that the angle α2 with respect to the perpendicular direction (entry direction) of the B side of the etching blade (122) is 14° to 20°. The sum of the two angles (α1+α2) is preferably 20° or more to ensure sufficient strength of the cutting blade, and preferably 40° or less to ensure easy cutting. Both angles (α1, α2) may be the same (α1=α2). In this case, the etching blade (122) is double-edged as shown in FIG. 9. Both angles (α1, α2) may be different. In this case, the etching blade (122) may be a single blade with an angle α1 of 0° as shown in FIG. 10, a double blade with α1 < α2 as shown in FIG. 11, or a double blade with α1 > α2. Typically, when the two angles (α1, α2) are different, α1 < α2.

[0101] From the perspective of increasing the distance d, it is preferable for the angle α1 to be large. On the other hand, from the perspective of minimizing damage (such as deterioration) to the optical laminate film with the adhesive layer attached due to the entry of the etching blade during cutting, it is preferable for the angle α1 to be small.

[0102] When punching, a side having a protective area can be formed by introducing the etching blade (122) from the side of the separator film (32). Additionally, by adjusting the shape of the etching blade (122) and the speed of the etching blade (122) entering the laminated film (150), the distance d between the shortest position of the adhesive layer (31) and the shortest position of the polarizer layer (21) can be adjusted. The larger the angle (α1+α2) of the tip of the etching blade (122) and the blunter the tip, the larger the distance d can be.

[0103] The material of the butt plate (160) is not limited, but, for example, a butt plate made of polypropylene can be used.

[0104] In the method for manufacturing an optical laminate film (110) with an adhesive layer attached as shown in FIG. 2, the punching of the outer frame and the punching of the through hole (51) may be performed simultaneously or at different timings. From the perspective of improving the positional accuracy of the punching, it is preferable to perform them simultaneously.

[0105] In a method for manufacturing an optical laminate film with an adhesive layer attached, the cutting process preferably involves forming the side surface by punching with an etching blade, and may also be combined with methods such as cutting using a router, or performing perforation using a rotary cutting mechanism such as a drill.

[0106] [Image display device]

[0107] An optical laminate film with an adhesive layer attached can be used in an image display device. Examples of image display elements used in an image display device include liquid crystal display elements and organic EL display elements. When constructing a liquid crystal display device, the optical laminate film with an adhesive layer attached may be used by being placed on the viewing side, may be used by being placed on the backlight side, or may be used on both the viewing side and the backlight side.

[0108] Examples

[0109] The present invention will be explained in more detail below using examples, but the present invention is not limited to these examples. In the examples, "%" and "parts" refer to mass % and mass parts, respectively, unless otherwise specified. Tests and measurements were performed as follows.

[0110] [Optical laminate film with adhesive layer attached A] (Example)

[0111] <Manufacturing Process of Fabric Laminated Film>

[0112] A laminated film having the same layer composition as the optical laminated film (130) with an adhesive layer attached in the first embodiment shown in FIG. 4, “surface protection film (24) / first protection layer (22) / polarizer layer (21) / second protection layer (23) / adhesive layer (31) / separator film (32)” was manufactured as follows.

[0113] (Fabrication of polarizer layer (21))

[0114] A long-length polyvinyl alcohol film was dyed in an aqueous solution containing iodine, and then uniaxially stretched six times in the longitudinal direction between rolls with different speed ratios in an aqueous solution containing boric acid to obtain a long-length polarizer layer having an absorption axis in the longitudinal direction. After stretching, this long-length polarizer layer was wound to form a wound body. The luminous sensitivity-corrected polarization degree of the polarizer layer was approximately 99.995%, the luminous sensitivity-corrected single transmittance was 42.7%, and the thickness was 12 μm.

[0115] (Preparation of the first protective layer (22))

[0116] As the first protective layer (22), a long-length hard-coating layer attached triacetylcellulose film (thickness 32 μm, manufactured by Toppan Printing Company, product name: 25KCHCN-TC) was prepared.

[0117] (Preparation of the second protective layer (23))

[0118] As a second protective layer (23), a long ring-shaped polyolefin resin film (thickness 13 μm, Zeonoa film manufactured by Nippon Zeon Co., Ltd., product name: ZF14-013) was prepared.

[0119] (Lamination process)

[0120] After cutting the polarizer layer (21), the first protective layer (22), and the second protective layer (23) prepared or manufactured as described above into 300 mm × 400 mm sections, the first protective layer (22) and the second protective layer (23) were bonded to both sides of the polarizer layer (21) using a polyvinyl alcohol-based adhesive, and placed in an 80°C drying oven for 3 minutes. Next, the surface of the second protective layer (23) was corona treated, and an acrylic adhesive layer (31) (thickness 20 μm) with a separator film (32) bonded to the corona treated surface was laminated. Finally, a non-adhesive release film, which is a surface protection film (24), was laminated to the surface of the first protective layer (22) to obtain a laminated film. The corona treatment was performed using a corona discharge device manufactured by Kasuga Electric Co., Ltd. Specifically, a corona surface treatment frame "STR-1764", a high-frequency power supply "CT-0212", and a high-voltage transformer "CT-T02W" were used. In this laminated film, a polyvinyl alcohol-based adhesive layer (thickness 0.2 μm or less) is interposed between the polarizer layer (21) and the first protective layer (22), and a polyvinyl alcohol-based adhesive layer (thickness 0.2 μm or less) is also interposed between the polarizer layer (21) and the second protective layer (22).

[0121] <Cutting Process>

[0122] One sheet of the obtained laminated film (300 mm × 400 mm) was punched into the shape of the optical laminated film with an adhesive layer attached as shown in FIG. 3 using an etching blade as shown in FIG. 8 to obtain an optical laminated film with an adhesive layer attached A. As the etching blade, a double-edged etching blade with α1 = α2 = 15° as shown in FIG. 9 was used. During the punching shown in FIG. 8, the laminated film (150) was positioned such that the surface protection film (24) of the laminated film was positioned toward the butt plate (160) and the separator film (32) was positioned toward the butt plate (160). The four corners were each fixed to the butt plate (160) with curing tape, and the etching blade was inserted into the laminated film from the separator film (32) side. The punching was performed so that the absorption axis of the polarizer layer (21) became parallel to the longitudinal direction of the optical laminated film with an adhesive layer attached A. Additionally, the cutting blade was used to reciprocate for a stroke of 24 mm (sufficiently exceeding the thickness of the laminated fabric film) in the punching direction (referred to as "one stroke"), and the laminated fabric film (150) was cut at the return point of the reciprocating motion by reciprocating for 1.5 seconds. As for the butting plate (160), one acrylic sheet (thickness 3.5 mm) and one polypropylene sheet (thickness 1.0 mm) were polymerized. The butting plate (160) was used so that the polypropylene sheet side was in contact with the laminated fabric film (150).

[0123] [Optical laminate film B with adhesive layer attached] (Comparative example)

[0124] <Manufacturing Process of Fabric Laminated Film>

[0125] A raw material laminated film was produced by the same method as the production process in optical laminated film A with an adhesive layer attached.

[0126] <Cutting Process>

[0127] One sheet of the obtained laminated film (300 mm × 400 mm) was punched into the shape of the optical laminated film with an adhesive layer attached as shown in FIG. 3 using an etching blade as shown in FIG. 8 to obtain an optical laminated film with an adhesive layer attached B. During the punching shown in FIG. 8, the laminated film (150) was positioned such that the separator film (32) of the laminated film was positioned toward the butt plate (160) and the surface protection film (24) was positioned toward the butt plate (160). The four corners were each fixed to the butt plate (160) with curing tape, and the etching blade was inserted into the laminated film from the side of the surface protection film (24). The punching was performed so that the absorption axis of the polarizer layer (21) became parallel to the length direction (length 400 mm) of the optical laminated film with an adhesive layer attached B. Additionally, the cutting blade was used to reciprocate for a stroke of 24 mm (sufficiently exceeding the thickness of the laminated fabric film) in the punching direction (referred to as "one stroke"), and the laminated fabric film (150) was cut at the return point of the reciprocating motion by reciprocating for 1.5 seconds. As for the butting plate (160), one acrylic sheet (thickness 3.5 mm) and one polypropylene sheet (thickness 1.0 mm) were polymerized. The butting plate (160) was used so that the polypropylene sheet side was in contact with the laminated fabric film (150).

[0128] [Optical laminate film C with adhesive layer attached] (Example)

[0129] <Manufacturing Process of Fabric Laminated Film>

[0130] A laminated film having the same layer composition as the optical laminated film (140) with an adhesive layer attached in the second embodiment shown in FIG. 5, “surface protection film (24) / first protection layer (22) / polarizer layer (21) / second protection layer (23) / first bonding layer (25) / first liquid crystal curing layer (26) / second bonding layer (27) / second liquid crystal curing layer (28) / adhesive layer (31) / separator film (32)” was manufactured as follows.

[0131] (Fabrication of polarizer layer (21))

[0132] A long-length polyvinyl alcohol film was dyed in an aqueous solution containing iodine, and then uniaxially stretched six times between rolls with different speed ratios in an aqueous solution containing boric acid to obtain a long-length polarizer layer having an absorption axis in the longitudinal direction. After stretching, this long-length polarizer layer was wound to form a wound body. The luminous sensitivity-corrected polarization degree of the polarizer layer was approximately 99.995%, the luminous sensitivity-corrected single transmittance was 42.7%, and the thickness was 12 μm.

[0133] (Preparation of the first protective layer (22))

[0134] As the first protective layer (22), a long-length hard-coating layer attached triacetylcellulose film (thickness 32 μm, manufactured by Toppan Printing Company, product name: 25KCHCN-TC) was prepared.

[0135] (Preparation of the second protective layer (23))

[0136] As a second protective layer (23), a long triacetylcellulose film (thickness 40 μm, manufactured by Konica Minolta, product name: KC4UYW) was prepared.

[0137] (Preparation of the first liquid crystal curing layer (26))

[0138] As the first liquid crystal curing layer (26), a film (thickness 1 μm) consisting of a layer cured from a nematic liquid crystal compound and an alignment layer was prepared. The in-plane phase difference value Re (550) of this first liquid crystal curing layer (26) was 140 nm, Re (450) / Re (550) was less than 1.0, and Re (650) / Re (550) was 1.0 second. With respect to this first liquid crystal curing layer (26), the indentation force measured by the indentation force measurement method described later was 8.8 g / mm.

[0139] (Preparation of the second liquid crystal curing layer (28))

[0140] As a second liquid crystal curing layer (28), a film (thickness 2 μm) composed of a layer cured of a rod-shaped liquid crystal compound and an alignment layer was prepared. This second liquid crystal curing layer (28) satisfies the relationship Nz > Nx = Ny within its plane, and the in-plane phase difference value Re (550) is 0.6 nm, and the thickness direction phase difference value Rth (550) is -69.6 nm. With respect to this second liquid crystal curing layer (28), the indentation force measured by the indentation force measurement method described later was 38.1 g / mm.

[0141] (Lamination process)

[0142] After cutting the polarizer layer (21), the first protective layer (22), the second protective layer (23), the first liquid crystal curing layer (26), and the second liquid crystal curing layer (28) produced or prepared as described above into 300 mm × 400 mm sections, the first protective layer (22) and the second protective layer (23) were bonded to both sides of the polarizer layer (21) using a polyvinyl alcohol-based adhesive, and placed in a drying oven at 80°C for 3 minutes. Subsequently, the surface of the second protective layer (23) was corona treated, and then an acrylic adhesive (thickness 5 μm) was laminated as the first bonding layer (25) on the corona-treated surface. The laminate obtained in this way is called the first laminate. The corona treatment was performed using a corona discharge device manufactured by Kasuga Electric Co., Ltd. Specifically, a corona surface treatment frame "STR-1764", a high-frequency power supply "CT-0212", and a high-voltage transformer "CT-T02W" were used.

[0143] Next, a UV-curable adhesive is applied to the surface of the first liquid crystal curing layer (26) to bond the second liquid crystal curing layer (28), and the adhesive is cured by irradiating ultraviolet light with an integrated light amount of 400 mJ / ㎠ (UV-B) using an ultraviolet irradiation device [manufactured by Fusion UV Systems Co., Ltd.] from the second liquid crystal curing layer (28). The laminated structure obtained in this way, consisting of a “first liquid crystal curing layer (26) / second bonding layer (27) composed of an adhesive layer / second liquid crystal curing layer (28)”, is called the second laminated body.

[0144] The first laminate and the second laminate obtained as described above were laminated such that the first bonding layer (25) of the first laminate and the first liquid crystal curing layer (26) of the second laminate were bonded. At this time, the lamination was performed such that the ground axis of the first liquid crystal curing layer (26) formed an angle of -45° with respect to the absorption axis of the polarizer layer (31).

[0145] After that, an acrylic adhesive layer (31) (thickness 20 μm) with a separating film (32) bonded to the surface of the second liquid crystal curing layer (28) was laminated. Finally, a non-adhesive release film, which is a surface protection film (24), was laminated to the surface of the first protective layer (22) to obtain a laminated film.

[0146] <Cutting Process>

[0147] One sheet of the obtained laminated film (300 mm × 400 mm) was punched into the shape of the optical laminated film with an adhesive layer attached as shown in FIG. 3 using an etching blade as shown in FIG. 8 to obtain an optical laminated film with an adhesive layer attached C. During the punching shown in FIG. 8, the laminated film (150) was positioned such that the surface protection film (24) of the laminated film was positioned toward the butt plate (160) and the separator film (32) was positioned toward the butt plate (160). The four corners were each fixed to the butt plate (160) with curing tape, and the etching blade was inserted into the laminated film from the separator film (32) side. The punching was performed so that the absorption axis (stretching direction) of the polarizer layer (21) became parallel to the length direction (400 mm) of the optical laminated film with an adhesive layer attached C. Additionally, the cutting blade was used to reciprocate for a stroke of 24 mm (sufficiently exceeding the thickness of the laminated fabric film) in the punching direction (hereinafter referred to as "one stroke"), and the laminated fabric film (150) was cut at the return point of the reciprocating motion by reciprocating for 1.5 seconds. As for the butting plate (160), one acrylic sheet (thickness 3.5 mm) and one polypropylene sheet (thickness 1.0 mm) were polymerized. The butting plate (160) was used so that the polypropylene sheet side was in contact with the laminated fabric film (150).

[0148] [Optical laminate film D with adhesive layer attached] (Comparative example)

[0149] <Manufacturing Process of Fabric Laminated Film>

[0150] A raw material laminated film was produced by the same method as the production process of optical laminated film D with an adhesive layer attached.

[0151] Punching Process

[0152] Sample 4 was obtained by punching one sheet of the obtained laminated film (300 mm × 400 mm) into the shape of the optical laminated film with an adhesive layer attached as shown in FIG. 3 using an etching blade as shown in FIG. 8. During the punching shown in FIG. 8, the laminated film (150) was positioned such that the separator film (32) of the laminated film was positioned toward the butt plate (160) and the surface protection film (24) was positioned toward the butt plate (160). The four corners were each fixed to the butt plate (160) with curing tape, and the etching blade was inserted into the laminated film from the side of the surface protection film (24). The punching was performed so that the absorption axis of the polarizer layer (21) became parallel to the length direction (400 mm) of the optical laminated film with an adhesive layer attached D. Additionally, the cutting blade was used to reciprocate for a stroke of 24 mm (sufficiently exceeding the thickness of the laminated fabric film) in the punching direction (hereinafter referred to as "one stroke"), and the laminated fabric film (150) was cut at the return point of the reciprocating motion by reciprocating for 1.5 seconds. As for the butting plate (160), one acrylic sheet (thickness 3.5 mm) and one polypropylene sheet (thickness 1.0 mm) were polymerized. The butting plate (160) was used so that the polypropylene sheet side was in contact with the laminated fabric film (150).

[0153] [Side view]

[0154] Regarding optical laminated films A to D with adhesive layers attached, the cross-sectional shape of the starting position of the curved surface region on the side was observed using an optical microscope. Figures 12 (a) and (b) are schematic diagrams showing observation images by an optical microscope regarding optical laminated films A and B with adhesive layers attached. Figures 13 (a) and (b) are schematic diagrams showing observation images by an optical microscope regarding optical laminated films C and D with adhesive layers attached.

[0155] As can be seen in FIGS. 12 and 13, the side of optical laminate films A and C, which have adhesive layers attached, has the adhesive layer (31) protruding outward from the shortest position of the polarizer layer (21) and is also folded toward the polarizer layer (21). In other words, a protective area was formed. Meanwhile, the side of optical laminate films B and D, which have adhesive layers attached, has the adhesive layer (31) protruding outward from the shortest position of the polarizer layer (21), but is folded toward the opposite side of the polarizer layer (21). In other words, it did not have a protective area. Also, for all optical laminate films A to D, the distance d between the shortest position of the adhesive layer (31) and the shortest position of the polarizer layer (21) was 15 μm. In addition, for all optical laminate films A to D with adhesive layers attached, the polyvinyl alcohol-based adhesive layer interposed between the polarizer layer (21) and the first protective layer (22), and the polyvinyl alcohol-based adhesive layer interposed between the polarizer layer (21) and the second protective layer (23) were not observed. For both optical laminate films C and D with adhesive layers attached, the first bonding layer (25), the second liquid crystal curing layer (26), the second bonding layer (27), and the second liquid crystal curing layer (28) could not be observed separately, but were observed as a single layer (shown as layer (29) in (a) and (b) of FIG. 13).

[0156] [Thermal Shock Test]

[0157] Regarding optical laminate films A to D with adhesive layers attached, they were bonded to the surface of alkali-free glass (Corning Eagle XG, 120×200×0.7 mm) that had been wiped with ethanol, and then autoclaved for 20 minutes at 50°C and 0.5 MPa (gauge pressure). This was used as an evaluation sample.

[0158] Evaluation samples were placed in a thermal shock test chamber, and thermal stimuli of -40°C and 85°C were applied for 30-minute cycles each. With the thermal stimulation from low temperature to high temperature counting as one cycle, a total of 100 cycles of testing were performed for each sample.

[0159] [Crack Evaluation]

[0160] The occurrence of cracks in the evaluation samples after the above thermal shock test was observed using an optical microscope. In particular, the curved surface area was observed in detail. An optical microscope image of an example of the cracks that occurred is shown in FIG. 14. This figure (optical microscope image) is an optical microscope image taken from the upper surface of a specific area common to optical laminate films A and B with adhesive layers attached. Cracks occurring from the curved surface area defined to be the same range for each evaluation sample were observed, and the cracks were classified as follows based on the length of the cracks, and the number of cracks included in each classification was measured. The results are shown in Table 1.

[0161] Short cracks: Cracks with a length of less than 100 µm

[0162] Intermediate crack: A crack with a length of 100 µm or more and less than 200 µm

[0163] Long crack: A crack with a length of 200 µm or more

[0164]

[0165] As shown in Table 1, optical laminate films A and C with adhesive layers attached according to the present invention did not develop cracks even after 100 cycles of thermal shock testing.

[0166] [Measurement of Indentation Force]

[0167] As sample A, a triacetylcellulose film with a thickness of 60 μm; as sample B, a triacetylcellulose film with a thickness of 20 μm; as sample C, a cycloolefin polymer film with a thickness of 23 μm; and as samples D and E, a first liquid crystal curing layer (26) and a second liquid crystal curing layer (28) prepared during the production of optical laminate films C and D with adhesive layers attached were prepared, and the indentation force of each sample was measured by the following method.

[0168] As shown in FIG. 15 (a) as a top view and (b) as a cross-sectional view, each sample (170) was cut into a 30 mm × 30 mm rectangle, and a thick paper (171) (thickness 85 μm, 30 mm × 30 mm rectangle) having a 10 mm × 10 mm rectangular opening (171a) in the center was adhered to the opening (171a) by blocking it through an adhesive layer (172) with a thickness of 25 μm. Then, from the upper side of the sample (170) at the blocked opening (171a), an iron rod (173) with a tip diameter of 1.0 mm was pressed in at a speed of 0.33 mm / s, and the indentation force for the amount of deformation in the thickness direction was measured using a handheld compression tester (KEN-G5, manufactured by Kato Tech Co., Ltd.). FIG. 16 shows the measurement results. Table 2 shows the slope of the indentation force calculated based on the measurement results of Figure 16.

[0169] Explanation of the symbols

[0170] 20: Optical laminated film, 21: Polarizer layer, 22: First protective layer, 23: Second protective layer, 24: Surface protective film, 25: First bonding layer, 26: First liquid crystal curing layer, 27: Second bonding layer, 28: Second liquid crystal curing layer, 31: Adhesive layer, 32: Separator film, 51: Through hole, 52: Corner portion, 53: Concave portion, 100, 110, 120, 130, 140: Optical laminated film with adhesive layer attached, 100a, 130a, 140a: Protective area, 121: Etching blade type, 122: Etching blade, 122a: Blade tip, 122b: Main body, 150: Fabric laminated film, 160: Butt plate.

Claims

Claim 1 An optical laminated film comprising a polarizer layer in which a dichroic pigment is adsorbed and oriented, and an adhesive layer for bonding the optical laminated film to a substrate, wherein the adhesive layer-attached optical laminated film has a through hole or a concave portion on its outer edge, and at least a portion of the side of the through hole or the concave portion of the adhesive layer-attached optical laminated film is a protective region in which the adhesive layer protrudes outwardly from the shortest position of the cross-section of the polarizer layer and is folded up toward the polarizer layer. Claim 2 In claim 1, the optical laminate film with an adhesive layer attached has through holes. Claim 3 In claim 1, the optical laminate film with an adhesive layer attached has a concave portion on its outer edge. Claim 4 delete Claim 5 In claim 1, at least a portion of the side surface of the optical laminate film with the adhesive layer attached is a curved region in which the contour on the surface opposite to the adhesive layer side of the optical laminate film is curved, and at least a portion of the curved region is the protective region, the optical laminate film with the adhesive layer attached. Claim 6 An optical laminate film with an adhesive layer attached, wherein the protective region in the curved region comprises a portion in which the angle θ formed by the contour with respect to the absorption axis direction of the polarizer layer changes continuously and the angle θ is greater than 0° and less than or equal to 90°. Claim 7 An optical laminate film with an adhesive layer attached, wherein, in any one of claims 1 to 3, 5 and 6, the protective area is a cut surface. Claim 8 An optical laminate film with an adhesive layer attached, wherein, in any one of claims 1 to 3, 5 and 6, the protective region comprises a region in which the distance d formed by the shortest position of the cross-section of the adhesive layer and the shortest position of the cross-section of the polarizer layer is 10 μm or more. Claim 9 An optical laminate film with an adhesive layer attached, wherein, in any one of claims 1 to 3, 5 and 6, a separator film peelably bonded to a surface opposite to the side of the optical laminate film of the adhesive layer. Claim 10 An optical laminate film with an adhesive layer attached, wherein, in any one of claims 1 to 3, 5 and 6, the optical laminate film comprises a liquid crystal curing layer formed of a polymerized cured product of a polymerizable liquid crystal compound. Claim 11 An optical laminate film with an adhesive layer attached, wherein, in any one of claims 1 to 3, 5 and 6, the optical laminate film comprises a protective layer on the side opposite to the adhesive layer when viewed from the polarizer layer, and the protective layer comprises a hard coating layer constituting a surface on the side opposite to the polarizer layer. Claim 12 A method for manufacturing an optical laminate film with an adhesive layer attached as described in any one of claims 1 to 3, 5 and 6, comprising: a process of preparing a base laminate film having, in this order, an optical laminate film including a polarizer layer in which a dichroic pigment is adsorbed and oriented, an adhesive layer, and a separate film peelably bonded to the adhesive layer; and a cutting process of introducing an etching blade into the base laminate film from the side of the separate film to cut the base laminate film to form a through hole or a concave portion, and forming a protective region on at least a part of the side of the through hole or the side of the concave portion in which the adhesive layer protrudes outwardly from the shortest position of the cross-section of the polarizer layer and is folded up toward the polarizer layer. Claim 13 delete Claim 14 A method for manufacturing an optical laminate film with an adhesive layer attached, wherein, in claim 12, the etching blade has an angle of 25° to 35° at the tip and a body thickness of 0.2 mm to 0.6 mm.

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