Optical laminated film with adhesive layer and method for producing the same

Abstract

The object of the present invention is to provide an optical laminated film with an adhesive layer in which crack generation is suppressed. An optical laminated film with an adhesive layer is an optical laminated film with an adhesive layer, which is an optical laminated film including a polarizer layer adsorbed and oriented with a dichroic pigment, and an optical laminated film with an adhesive layer in sequence, wherein at least a portion of a side surface of the optical laminated film with an adhesive layer is a protective region in which the adhesive layer protrudes outward from the end position of the polarizer layer and warps toward the polarizer layer side.

Description

Technical Field

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

[0002] In recent years, the design of image display devices has gradually diversified. Influenced by this trend, optical laminated films including linear polarizing films are also required to cope with various shapes. In Japanese Patent Publication No. 2018-25630, a polarizing plate with a concave portion at the outer edge and a polarizing plate with a through hole in the plane are disclosed.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-25630 Summary of the invention

[0006] Problems to be solved by the invention

[0007] An optical layered film having a shape having a concave portion at an outer edge portion and an optical layered film having a shape having a through hole in a plane have a problem that cracks are easily generated.

[0008] An object of the present invention is to provide an optical laminated film with a pressure-sensitive adhesive layer in which crack generation is suppressed, and a method for producing the same.

[0009] Methods used to solve problems

[0010] The present invention provides the following optical laminated film with a pressure-sensitive adhesive layer and a method for producing the optical laminated film with a pressure-sensitive adhesive layer.

[0011] [1] An optical laminated film with an adhesive layer, comprising an optical laminated film and an adhesive layer in this order, wherein the optical laminated film comprises a polarizing layer to which a dichroic dye is adsorbed and oriented,

[0012] At least a portion of a side surface of the optical laminate film with an adhesive layer is a protection region in which the adhesive layer protrudes outward from an end position of the polarizer layer and rises toward the polarizer layer.

[0013] [2] The optical laminate film with an adhesive layer according to [1], wherein at least a portion of the side surface of the optical laminate film with an adhesive layer is a curved surface region, that is, the contour of the surface of the optical laminate film on the side opposite to the adhesive layer side is a curved line,

[0014] At least a portion of the curved surface area is the protection area.

[0015] [3] An optical laminate film with an adhesive layer according to [2], wherein the protective area in the curved area includes a portion in which an angle θ between the contour and the absorption axis direction of the polarizer layer changes continuously, and the angle θ is greater than 0° and less than 90°.

[0016] [4] The optical laminate film with a pressure-sensitive adhesive layer according to any one of [1] to [3], wherein the protection region is a cut surface.

[0017] [5] The optical laminate film with an adhesive layer according to any one of [1] to [4], wherein the protective region includes a region where a distance d between the end position of the adhesive layer and the end position of the polarizer layer is 10 μm or more.

[0018] [6] The optical laminated film with a pressure-sensitive adhesive layer according to any one of [1] to [5], further comprising a separator releasably bonded to a surface of the pressure-sensitive adhesive layer on the side opposite to the optical laminated film side.

[0019] [7] The pressure-sensitive adhesive layer-carrying optical laminate film according to any one of [1] to [6], wherein the optical laminate film comprises a liquid crystal cured layer containing a polymerized cured product of a polymerizable liquid crystal compound.

[0020] [8] The optical laminated film with a pressure-sensitive adhesive layer according to any one of [1] to [7], wherein the optical laminated film includes a protective layer on the side opposite to the pressure-sensitive adhesive layer when viewed from the polarizer layer.

[0021] The protective layer includes a hard coat layer constituting a surface opposite to the polarizer layer side.

[0022] [9] A method for producing an optical laminated film with an adhesive layer, comprising:

[0023] A step of preparing a raw laminate film, the raw laminate film comprising, in order, an optical laminate film including a polarizer layer on which a dichroic dye is adsorbed and oriented, an adhesive layer, and a separator releasably bonded to the adhesive layer; and

[0024] In the cutting step, an etching knife is inserted into the original material laminate film from the diaphragm side to cut the original material laminate film and form a side surface.

[0025]

[10] A method for producing an optical laminate film with an adhesive layer according to [9], wherein at least a portion of the side surface is a protective region in which the adhesive layer protrudes outward from the end position of the polarizer layer and warps toward the polarizer layer.

[0026] Effects of the Invention

[0027] According to the present invention, an optical laminated film with a pressure-sensitive adhesive layer in which generation of cracks is suppressed can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic cross-sectional view schematically showing an example of the optical laminated film with a pressure-sensitive adhesive layer of the present invention.

[0029] Figure 2 This is a plan view showing an example of an optical laminate film with a pressure-sensitive adhesive layer having a curved surface region on a side surface.

[0030] Figure 3 This is a plan view showing another example of an optical laminate film with a pressure-sensitive adhesive layer having a curved surface region on a side surface.

[0031] Figure 4 It is a schematic cross-sectional view schematically showing the optical laminated film with a pressure-sensitive adhesive layer according to the first embodiment.

[0032] Figure 5 It is a schematic cross-sectional view schematically showing an optical laminated film with a pressure-sensitive adhesive layer according to the second embodiment.

[0033] Figure 6 It is a top view showing an example of an etching die.

[0034] Figure 7 Yes means Figure 6 A cross-sectional view of the etching knife is shown.

[0035] Figure 8 It is a cross-sectional view schematically showing a cutting step in the production method of the present invention.

[0036] Fig. 9 This is a cross-sectional view schematically showing an example of the cross-sectional shape of an etching blade.

[0037] Fig.10 This is a cross-sectional view schematically showing an example of the cross-sectional shape of an etching blade.

[0038] Fig.11 This is a cross-sectional view schematically showing an example of the cross-sectional shape of an etching blade.

[0039] Fig.12 It is a cross-sectional view schematically showing an observed image of the cross section of the pressure-sensitive adhesive layer-attached optical layered films A and B observed under an optical microscope.

[0040] Fig.13 It is a cross-sectional view schematically showing an observed image of the cross section of the pressure-sensitive adhesive layer-attached optical laminated films C and D observed using an optical microscope.

[0041] Fig.14 The optical microscope images show the upper surfaces of the optical layered films A and B with pressure-sensitive adhesive layers.

[0042] Fig.15 This is a schematic diagram showing a method for measuring the push force.

[0043] Fig.16 It is a graph showing the measurement results of the pushing force.

[0044] Description of Reference Numerals

[0045] 20 optical laminate film, 21 polarizing 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 diaphragm, 51 through hole, 52 corner, 53 concave portion, 100, 110, 120, 130, 140 optical laminate film with adhesive layer, 100a, 130a, 140a protection area, 121 etching knife die, 122 etching knife, 122a knife tip, 122b main body, 150 raw material laminate film, 160 pad. DETAILED DESCRIPTION

[0046] [Optical laminated film with adhesive layer]

[0047] Figure 1 Schematic cross-sectional view schematically showing an example of an optical laminate film with an adhesive layer of the present invention. Figure 1 As shown, the optical laminated film 100 with a pressure-sensitive adhesive layer includes an optical laminated film 20 including a polarizing layer 21 to which a dichroic dye is adsorbed and oriented, and a pressure-sensitive adhesive layer 31 in this order.

[0048] At least a portion of the side surface of the optical laminate film 100 with an adhesive layer is a protective area. The "protective area" referred to in this specification refers to the area on the side surface where the adhesive layer 31 is in a state of protruding outward compared to the end position of the polarizer layer 21 and warping toward the polarizer layer 21 side. The range of the "side area" in this specification is set to a range in which all positions arranged along the stacking direction on the side surface are included in the same area. In this specification, the so-called warping toward the polarizer layer 21 side means that the protruding portion of the adhesive layer 31 has a portion that is closer to the polarizer layer 21 side than other portions. The protruding portion of the adhesive layer 31 may be close to the polarizer layer 21 side, and the adhesive layer 31 may contact the entire side surface of the polarizer layer 21, or may contact a portion of the side surface of the polarizer layer 21, as in Figure 1 As shown, the adhesive layer 31 does not contact the side surface of the polarizing plate layer 21 but is bent toward the polarizing plate layer 21 side. Figure 1The side area 100a shown is a protection area.

[0049] The optical laminate film 100 with an adhesive layer can suppress the generation of cracks by having a protective region 100a on the side surface. It is presumed that this is because the generation of cracks is suppressed in the protective region 100a because the side surface of the optical laminate film 20 is protected by the adhesive layer 31. Cracks are likely to be generated starting from the side surface or the vicinity of the side surface.

[0050] For the side of the optical laminated film 100 with an adhesive layer, at least a portion of the area is the protective area 100a, but from the viewpoint of suppressing the generation of cracks, it is preferred that the ratio of the area as the protective area 100a is high. Alternatively, it is preferred that the area of ​​the side where cracks are likely to occur is the protective area 100a. For example, more than 10% of the total area of ​​the side of the optical laminated film 100 with an adhesive layer is the protective area 100a. Or, for example, at least a portion of the curved surface area of ​​the side of the optical laminated film 100 with an adhesive layer includes the protective area 100a, and more than 50% of the total area of ​​the curved surface area is the protective area 100a.

[0051] The "curved surface region" in this specification refers to a region where the contour of the surface 20a on the side opposite to the adhesive layer 31 side of the optical laminate film 20 is a curved side. The "curved surface" in this part means that the angle θ formed with the absorption axis direction of the polarizer layer 21 changes continuously. In the curved surface region, cracks are likely to be generated starting from the side surface or the vicinity of the side surface.

[0052] Figure 2 This is a plan view showing an example of a pressure-sensitive adhesive layer optical laminate film having a curved surface region on a side surface. Figure 2 This is a plan view of the optical laminate film 110 with a pressure-sensitive adhesive layer as viewed from the surface opposite to the pressure-sensitive adhesive layer side. Figure 2 The optical laminate film 110 with an adhesive layer shown is a rounded square and has a through hole 51. The so-called rounded square means that one or more of the corners of the square are curved, that is, one or more of the corners of the square are rounded. All corners 52 of the optical laminate film 110 with an adhesive layer are rounded. Figure 2 The optical laminate film with a pressure-sensitive adhesive layer 110 shown has a curved surface region on the inner wall of the through hole 51 and the side surface of the corner portion 52. The angle θ formed by the contour of the curved surface region and the absorption axis direction of the polarizer layer changes continuously.

[0053] Figure 3 This is a plan view showing another example of an optical laminate film with a pressure-sensitive adhesive layer having a curved surface region on a side surface. Figure 3This is a plan view of the optical laminate film 120 with a pressure-sensitive adhesive layer as viewed from the surface opposite to the pressure-sensitive adhesive layer side. Figure 3 The optical laminate film 120 with an adhesive layer shown is in the shape of a square with rounded corners and has a concave portion 53 at the outer edge. Figure 3 The side surfaces of the concave portion 53 and the corner portion 52 of the outer edge of the optical laminate film with a pressure-sensitive adhesive layer 120 shown have curved surface regions. The angle θ formed between the contour of the curved surface region and the absorption axis of the polarizing layer changes continuously.

[0054] The optical laminate film with an adhesive layer may be as follows in a top view: Figure 2 , 3 The rounded square shown may also be a square. A square is a shape in which all four corners are not rounded. In addition, in this specification, a square is a rectangle or a square.

[0055] The angle θ between the profile of the side surface on the surface 20a and the absorption axis direction of the polarizer layer 31 is 0° to 90°, and the area where the angle θ changes continuously is set as the curved surface area. The curved surface area includes a portion where the angle θ is greater than 0° and less than 90°. This is because the curved surface area including such a portion is prone to cracks starting from the side surface or the vicinity of the side surface, so the effect of suppressing the generation of cracks brought about by the present invention is more significant.

[0056] Figure 1 In the protective region 100a of the optical laminate film 100 with an adhesive layer, the distance d between the end position of the adhesive layer 31 and the end position of the polarizer layer 21 is shown. The protective region 100a preferably includes a region where the distance d is greater than 10 μm, and more preferably includes a region where the distance d is greater than 15 μm. In such a region, it is easier to suppress the generation of cracks. In the protective region 100a, the distance d between the end position of the adhesive layer 31 and the end position of the polarizer layer 21 is, for example, less than 30 μm.

[0057] In the optical laminate film 100 with an adhesive layer, the side with the protection area 100a is, for example, a cut surface formed by cutting the laminate using a cutting knife. By adjusting the cutting knife used in cutting, the cutting direction, the cutting speed, the in-plane tension applied to the laminate during cutting, etc., a side with a protection area can be formed, and the protection area is an area where the adhesive layer 31 protrudes outward compared to the end position of the polarizer layer 21 and tilts toward the polarizer layer 21. If an etching knife (pointed knife) with a tip formed by etching is used as a cutting knife, the adhesive layer 31 protrudes and tilts, and the above-mentioned protection area 100a can be formed. In addition, the above-mentioned protection area 100a can also be formed in the same manner by increasing the cutting speed, that is, increasing the speed at which the cutting knife enters the laminate. If the in-plane tension applied to the laminate is increased, the above-mentioned protection area 100a can be formed. To increase the in-plane tension, for example, it is sufficient to increase the pressure of clamping the laminate during cutting.

[0058] The adhesive layer 31 can be used as an adhesive layer for bonding the optical laminate film 20 to an adherend such as a liquid crystal cell, an organic EL display element or other optical components. The optical laminate film 100 with an adhesive layer can have a separator that can be bonded to the surface of the adhesive layer 31 on the opposite side of the optical laminate film 20 side in a releasable manner.

[0059] The optical laminate film 20 may include other layers different from the polarizer layer 21, and examples of the other layers 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 side when viewed from the polarizer layer 31, and the protective layer may include a hard coating layer constituting the surface on the side opposite to the polarizer layer 21 side.

[0060] <First embodiment>

[0061] Figure 4 Schematic cross-sectional view schematically showing an optical laminate film with an adhesive layer according to the first embodiment. Figure 4 As shown, the optical laminated film 130 with a pressure-sensitive adhesive layer includes an optical laminated film 20 and a pressure-sensitive adhesive layer 31 in this order, and further includes a separator 32 releasably bonded to the surface of the pressure-sensitive adhesive layer 31 on the side opposite to the optical laminated film 20 .

[0062] The optical laminate film 20 sequentially comprises a surface protection film 24, a first protection layer 22, a polarizer layer 21, and a second protection layer 23. The first protection layer 22 has a hard coat layer constituting the surface opposite to the adhesive layer 31 side, and the surface protection film 24 is releasably bonded to the surface of the hard coat layer.

[0063] In the optical laminate film 130 with an adhesive layer, Figure 4The area 130a on the side shown is a protective area. In the protective area 130a, the adhesive layer 31 protrudes outward compared to the outermost end position of the polarizer layer 21 and is warped toward the polarizer layer 21 side.

[0064] <Second Embodiment>

[0065] Figure 5 is a schematic cross-sectional view schematically showing an optical laminate film with an adhesive layer according to the second embodiment. As Figure 5 shown, the optical laminate film 140 with an adhesive layer sequentially includes an optical laminate film 20 and an adhesive layer 31, and also includes a separator 32 that can be detachably attached to the surface on the side opposite to the optical laminate film 20 side of the adhesive layer 31.

[0066] The optical laminate film 20 sequentially includes a surface protective film 24, a first protective layer 22, a polarizer layer 21, a second protective 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. The first protective layer 22 has a hard coat that constitutes the surface on the side opposite to the adhesive layer 31 side, and the surface protective film 24 is detachably attached to the surface of the hard coat.

[0067] In the optical laminate film 140 with an adhesive layer, Figure 5 the area 140a on the side shown is a protective area. In the protective area 140a, the adhesive layer 31 protrudes outward compared to the outermost end position of the polarizer layer 21 and is warped toward the polarizer layer 21 side.

[0068] In the protective area 140a of the optical laminate film 140 with an adhesive layer, for other layers other than the adhesive layer 31, they may protrude outward compared to the outermost end position of the polarizer layer 21 in the same manner as the adhesive layer 31, or may also be in a shape that is warped toward the polarizer layer 21 side. Figure 5 shows the following situation, that is, in the protective area 140a, on the basis of the adhesive layer 31, the first bonding layer 25, the first liquid crystal curing layer 26, and the second liquid crystal curing layer 28 are also in a shape that protrudes outward compared to the outermost end position of the polarizer layer 21 and is warped toward the polarizer layer 21 side in the same manner as the adhesive layer 31. It can be speculated that in the side surface as a cut surface, in the layers where the slope of the pushing-in force (Japanese: 傾き) measured by the test method of the following examples is 50 g / mm or less, since the behavior when introducing the cutting knife is similar to that of the adhesive layer 31, it is likely to become a shape that protrudes outward compared to the outermost end position of the polarizer layer 21 and is also warped toward the polarizer layer 21 side in the same manner as the adhesive layer 31.

[0069] The optical laminate film with an adhesive layer of the present invention may include a layer with a slope of the pushing-in force of 50 g / mm or less.

[0070] Hereinafter, the materials and the like of the respective layers forming the optical laminated film with a pressure-sensitive adhesive layer will be described in detail.

[0071] (Optical laminate film 20)

[0072] The optical laminated film 20 includes a polarizer layer 21. The thickness of the optical laminated film 20 can be generally 5 μm or more and 200 μm or less, and may be 150 μm or less, or 120 μm or less.

[0073] (Polarizing Plate Layer 21)

[0074] As the polarizer layer 21, a stretched film or stretched layer adsorbed with a pigment having absorption anisotropy, a layer formed by coating a pigment having absorption anisotropy and curing the same, etc. can be cited. As the pigment having absorption anisotropy, for example, a dichroic pigment can be cited. As the dichroic pigment, specifically, iodine and dichroic organic dyes are used. The dichroic organic dyes include CIDIRECT RED 39 and other dichroic direct dyes composed of disazo compounds, and dichroic direct dyes composed of compounds such as triazo and tetrazo.

[0075] 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, 15 μm or less, or 10 μm or less.

[0076] (1) Polarizer layer as stretched film or stretched layer

[0077] As the polarizer layer formed by coating and curing a dye having absorption anisotropy, there can be cited a polarizer layer containing a cured product of a polymerizable liquid crystal compound, such as a layer obtained by coating and curing a composition containing a dichroic dye having liquid crystal properties or a composition containing a dichroic dye and a polymerizable liquid crystal. Compared with a stretched film or stretched layer adsorbed with a dye having absorption anisotropy, a polarizer layer formed by coating and curing a dye having absorption anisotropy is not limited in the bending direction and is therefore preferred.

[0078] The polarizing layer as a stretched film on which a dye having absorption anisotropy is adsorbed can generally be manufactured through the following steps, namely, a step of uniaxially stretching a polyvinyl alcohol resin film, a step of adsorbing the dichroic dye by dyeing the polyvinyl alcohol resin film with a dichroic dye, a step of treating the polyvinyl alcohol resin film on which the dichroic dye is adsorbed with an aqueous boric acid solution, and a step of washing the film with water after the treatment with the aqueous boric acid solution.

[0079] The polyvinyl alcohol resin can be obtained by saponifying a polyvinyl acetate resin. As the polyvinyl acetate resin, polyvinyl acetate, which is a homopolymer of vinyl acetate, can be used, and copolymers of vinyl acetate and other monomers copolymerizable therewith can also be used. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth)acrylamides having an ammonium group.

[0080] The saponification degree of the polyvinyl alcohol resin is usually 85 mol% or more and 100 mol% or less, preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, for example, polyvinyl formal and polyvinyl acetal modified by aldehydes may be used. The polymerization degree of the polyvinyl alcohol resin is usually 1000 or more and 10000 or less, preferably 1500 or more and 5000 or less.

[0081] The polarizer layer as a stretched layer adsorbed with a pigment having anisotropy of absorption can usually be manufactured through the following steps, that is, a step of applying a coating liquid containing the above-mentioned polyvinyl alcohol resin on a substrate film, a step of uniaxially stretching the obtained laminated film, a step of adsorbing the dichroic pigment and forming a polarizer layer by dyeing the polyvinyl alcohol resin layer of the laminated film through uniaxial stretching with a dichroic pigment, a step of treating the film adsorbed with the dichroic pigment with an aqueous boric acid solution, and a step of washing with water after the treatment with an aqueous boric acid solution. The substrate film can be peeled off from the polarizer layer as needed. For the material of the substrate film, the same material as the substrate film of the surface protection film 24 described later can be exemplified.

[0082] (2) A polarizing layer formed by coating and curing a pigment having anisotropic absorption

[0083] As the polarizer layer formed by coating with anisotropic absorption pigment and solidifying it, the composition comprising a polymerizable dichroic pigment with liquid crystal or the composition comprising a dichroic pigment and polymerizable liquid crystal can be enumerated, and the layer obtained by coating the composition on the substrate film and solidifying it, etc., comprises a polarizer layer of a solidified material of a polymerizable liquid crystal compound. As required, the substrate film can be peeled off and removed from the polarizer layer. For the material of the substrate film, the material identical with the substrate film of the surface protection film 24 described later can be exemplified.

[0084] (First protective layer 22, second protective layer 23)

[0085] The optical laminate film 20 may include a first protective layer 22 laminated on the surface of the polarizer layer 21 opposite to the adhesive layer 31 side, and may include a second protective layer 23 laminated on the surface of the polarizer layer 21 on the adhesive layer 31 side. The first protective layer 22 and the second protective layer 23 can be set as an optically transparent coating or film containing a thermoplastic resin, for example, it can be set as a polyolefin resin such as a chain polyolefin resin (polypropylene resin, etc.), a cyclic polyolefin resin (norbornene resin, etc.); a cellulose resin such as triacetyl cellulose and diacetyl cellulose; a polyester resin such as polyethylene terephthalate and polybutylene terephthalate; a polycarbonate resin; a (meth) acrylic resin such as methyl methacrylate resin; a polystyrene resin; a polyvinyl chloride resin; 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 a coating or film of a mixture of one or more of them. The thickness of the protective layer is usually 1 μm or more and 100 μm or less, and may be 5 μm or more and 80 μm or less, 60 μm or less, or 50 μm or less.

[0086] The protective film can be bonded to the polarizer layer 21 via an adhesive layer, for example. Examples of the adhesive forming the adhesive layer include water-based adhesives, active energy ray-curable adhesives, and thermosetting adhesives, and water-based adhesives and active energy ray-curable adhesives are preferably used.

[0087] The two surfaces facing each other to be bonded together via the adhesive layer may be subjected to corona treatment, plasma treatment, flame treatment or the like in advance, or may have a primer layer or the like.

[0088] The first protective layer 22 and the second protective layer 23 may be protective layers made of the same material or 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, an anti-reflection layer, a hard coating layer, an antistatic layer, an antifouling layer, and other surface treatment layers on its surface. When the first protective layer 22 has a hard coating layer, cracks are easily generated. However, according to the present invention, even with such a structure, the generation of cracks can be suppressed.

[0089] (Surface protection film 24)

[0090] The optical laminate film 20 may include a surface protection film 24 constituting the surface opposite to the surface on the side of the adhesive layer 31. For example, after the optical laminate film with an adhesive layer is bonded to an image display device or other optical member, the surface protection film 24 is peeled off together with the adhesive layer it has.

[0091] 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 to 100 μm, preferably 20 μm to 80 μm, and more preferably 30 μm to 60 μm.

[0092] The resin forming the substrate film can be, for example, a chain polyolefin resin such as polyethylene and polypropylene; a cyclic polyolefin resin such as a norbornene resin; a polyester resin such as polyethylene terephthalate and polyethylene naphthalate; a polycarbonate resin; a thermoplastic resin such as a mixture of one or more of them. The substrate layer may be a single-layer structure or a multi-layer structure, but from the viewpoints of ease of manufacture and manufacturing cost, a single-layer structure is preferred. The substrate layer may be a uniaxially stretched film or a biaxially stretched film, but from the viewpoints of mechanical strength of the film, ease of manufacture and manufacturing cost, a biaxially stretched film is preferred.

[0093] The adhesive layer can be composed of an adhesive composition having a resin such as (meth) acrylic acid, rubber, urethane, ester, silicone, or polyvinyl ether as a main component. Among them, an adhesive composition having excellent transparency, weather resistance, heat resistance, etc. and having a (meth) acrylic resin as a base polymer is suitable. The adhesive composition can be an active energy ray curable type or a heat curable type.

[0094] (First Liquid Crystal Cured Layer 26, Second Liquid Crystal Cured Layer 28)

[0095] The optical laminate film 20 may contain one or more layers of a liquid crystal cured layer containing a polymerizable liquid crystal compound. The optical laminate film 140 with a laminating layer of the second embodiment includes a first liquid crystal cured layer 26 and a second liquid crystal cured layer 28 as liquid crystal cured layers. The liquid crystal cured layer may, for example, include a layer that functions as a phase difference layer. The liquid crystal cured layer may be formed by applying a composition containing a polymerizable liquid crystal compound to a substrate film and curing it. An orientation layer may be formed between the substrate film and the coating layer. The liquid crystal cured layer may be assembled into the optical laminate film 20 in a form having an orientation layer and / or a substrate film.

[0096] The liquid crystal cured layer can be formed using a known polymerizable liquid crystal compound. The type of the liquid crystal compound is not particularly limited, and a rod-like liquid crystal compound, a disc-like liquid crystal compound, and a mixture thereof can be used. Examples of the polymerizable liquid crystal compound include those described in JP-A-11-513019, JP-A-2005-289980, JP-A-2007-108732, JP-A-2010-244038, JP-A-2010-31223, JP-A-2010-270108, JP-A-2011-6360, JP-A-2011-207765, JP-A-2016-81035, International Publication No. 2017 / 043438, and JP-A-2011-207765.

[0097] For example, a composition containing a polymerizable liquid crystal compound is applied onto the alignment layer to form a coating film, and the coating film is cured to form a liquid crystal cured layer. The thickness of the liquid crystal cured layer is preferably 0.5 μm to 10 μm, more preferably 0.5 μm to 5 μm.

[0098] The composition containing the polymerizable liquid crystal compound may contain a polymerization initiator, a polymerizable monomer, a surfactant, a solvent, a close fit improver, a plasticizer, an alignment agent, etc. in addition to the polymerizable liquid crystal compound. As a coating method for the composition containing the polymerizable liquid crystal compound, a well-known method such as a die coating method can be cited. As a curing method for the composition containing the polymerizable liquid crystal compound, a well-known method such as irradiation with active energy rays (such as ultraviolet rays) can be cited.

[0099] (First bonding layer 25, second bonding layer 27)

[0100] In the optical laminated film 20, a laminating layer for bonding two layers may be included. The optical laminated film 140 with laminating layers of the second embodiment includes a first laminating layer 25 and a second laminating layer 27 as laminating layers. As laminating layers, adhesive layers, adhesive layers, etc. may be cited. The adhesive layer may use a water-based adhesive, an active energy ray-curable adhesive, or a thermosetting adhesive, etc. For the adhesive layer, the description of the adhesive layer provided on the surface protective film 24 may be applied.

[0101] The two surfaces facing each other to be bonded via the bonding layer may be subjected to corona treatment, plasma treatment, flame treatment or the like in advance, or may have a primer layer or the like.

[0102] (Phase difference layer)

[0103] The optical laminate film 20 may include one or more phase difference layers. The phase difference layer may be a liquid crystal solidification layer as described above, or may be a resin film. Examples of the phase difference layer include positive A plates such as a λ / 4 plate and a λ / 2 plate, and positive C plates.

[0104] <Adhesive layer 31>

[0105] The adhesive layer 31 may be composed of an adhesive composition having a resin such as (meth) acrylic acid, rubber, urethane, ester, silicone, or polyvinyl ether as a main component. Among them, an adhesive composition having (meth) acrylic acid resin as a base polymer having excellent transparency, weather resistance, and heat resistance is suitable. The adhesive composition may also be an active energy ray curing type or a heat curing type.

[0106] As the (meth)acrylic resin (base polymer) used in the adhesive composition, for example, a polymer or copolymer having one or more of (meth)acrylates such as butyl (meth)acrylate, ethyl (meth)acrylate, isooctyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate as monomers can be suitably used. It is preferred to copolymerize a polar monomer with the base polymer. As polar monomers, for example, monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group, and the like such as (meth)acrylic acid, 2-hydroxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate, (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylate, and glycidyl (meth)acrylate can be cited.

[0107] The adhesive composition may contain only the above-mentioned base polymer, but usually also contains a crosslinking agent. Examples of the crosslinking agent include a crosslinking agent that is a metal ion with a valence of two or more and forms a carboxylic acid metal salt with a carboxyl group; a crosslinking agent that is a polyamine compound and forms an amide bond with a carboxyl group; a crosslinking agent that is a polyepoxide compound or a polyol and forms an ester bond with a carboxyl group; and a crosslinking agent that is a polyisocyanate compound and forms an amide bond with a carboxyl group. Among them, a polyisocyanate compound is preferred.

[0108] The so-called active energy ray-curable adhesive composition is an adhesive composition having the following properties, that is, it is cured by irradiation with active energy rays such as ultraviolet rays and electron beams, and it has adhesiveness before irradiation with active energy rays and can be closely attached to adherends such as films, and it can be cured by irradiation with active energy rays to achieve adjustment of the close adhesion. The active energy ray-curable adhesive composition is preferably an ultraviolet curable type. The active energy ray-curable adhesive composition contains an active energy ray polymerizable compound on the basis of containing a base polymer and a crosslinking agent. In addition, it sometimes contains a photopolymerization initiator, a photosensitizer, etc. as needed.

[0109] The adhesive composition may contain additives such as microparticles for imparting light scattering properties, beads (resin beads, glass beads, etc.), glass fibers, resins other than base polymers, thickeners, fillers (metal powders, other inorganic powders, etc.), antioxidants, ultraviolet absorbers, dyes, pigments, colorants, defoaming agents, anticorrosive agents, photopolymerization initiators, and the like.

[0110] The adhesive layer 31 can be formed on the optical laminate film 20 by, for example, dissolving or dispersing the adhesive composition in an organic solvent such as toluene or ethyl acetate to prepare an adhesive solution, and applying it directly to the target surface of the polarizing plate to form the adhesive layer 31; forming the adhesive layer 31 in a sheet form on a separator subjected to a demolding treatment in advance, and then transferring it to the target surface of the optical laminate film 20. The adhesive layer 31 can be formed by applying an organic solvent dilution of the adhesive composition on a substrate and drying it. In the case of using an active energy ray-curable adhesive composition, a cured product having a desired degree of curing can be prepared by irradiating the formed adhesive layer 31 with active energy rays.

[0111] The thickness of the adhesive layer 31 is determined based on its adhesive strength and the like, and is preferably in the range of 1 μm to 50 μm, and preferably 2 μm to 40 μm.

[0112] The storage modulus of the adhesive layer 31 measured at a temperature of 20° C. and an angular frequency of 100 rad / s is usually 1 MPa or less, preferably 0.15 MPa or less. The storage modulus of the adhesive is usually 0.001 MPa or more, preferably 0.01 MPa or more.

[0113] <Diaphragm 32>

[0114] The optical laminated film with an adhesive layer may include a separator 32 provided on the surface of the adhesive layer 31. The separator 32 may be a film containing a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, a polyester resin such as polyethylene terephthalate, etc. Among them, a stretched film of polyethylene terephthalate is preferred. After the separator 32 is peeled off, the optical laminated film 20 is attached to the adherend via the adhesive layer 31.

[0115] [Method for producing an optical laminated film with an adhesive layer]

[0116] The manufacturing method of the optical laminated film with an adhesive layer of the present invention comprises: a step of preparing a raw laminated film, wherein the raw laminated film sequentially comprises an optical laminated film including a polarizer layer 21 on which a dichroic pigment is adsorbed and oriented, an adhesive layer, and a separator attached to the adhesive layer in a releasable manner; and a cutting step of inserting an etching knife into the raw laminated film from the separator side to cut the raw laminated film and form a side surface. As an optical laminated film with an adhesive layer obtained by such a manufacturing method, the above-mentioned optical laminated film with an adhesive layer having a protective region on the side surface can be exemplified.

[0117] Figure 6 It means in Figure 3 1 is a top view of an example of an etching die having an etching knife used in a cutting step in a method for manufacturing an optical laminate film 120 with an adhesive layer. The etching die 121 is a shape in which the etching knife protrudes three-dimensionally by etching a metal plate. Figure 6 The outline 122 shown represents the tip of the etching knife, which is consistent with the outline of the optical laminate film 120 with the adhesive layer.

[0118] The etching die 121 is pressed against the original laminated film, and the etching knife 122 is inserted into the original laminated film to cut, thereby punching out the optical laminated film 120 with an adhesive layer while forming the side. The original laminated film to be punched out can be stacked in multiple sheets. Since the dimensional accuracy of the resulting polarizing plate is good, one sheet is preferred. According to the etching die 121, six optical laminated films with an adhesive layer can be simultaneously produced in each original laminated film by punching out once. The sides of the optical laminated film 120 with an adhesive layer produced in this way are all cut surfaces.

[0119] The etching die 121 is manufactured by etching after patterning the resist film by laser irradiation. Therefore, a die with high dimensional accuracy can be obtained. On the other hand, since it is manufactured by etching, its blade tip is not relatively sharp. An etching knife is also called a pointed knife. In contrast, a Thomson knife is manufactured by mechanical grinding, so its blade tip is relatively sharp. As a reason why an optical laminate film with an adhesive layer having a protective area on the side can be obtained by the manufacturing method of the present invention, it can be inferred that by using a pointed knife as an etching knife during cutting, it is easier to apply force to the layer direction of the adhesive layer 31, thereby forming a protrusion on the adhesive layer 31, and by allowing the pointed knife to enter from the side of the diaphragm 32, the protrusion is easy to warp toward the polarizer layer 21 side.

[0120] Figure 71 is a cross-sectional view of the etching blade 122. The etching blade 122 includes a blade tip 122a and a body 122b. The angle β of the blade tip 122a is preferably 20° to 40°, more preferably 25° to 35°. The thickness t of the body 122b is preferably 0.1 mm to 1 mm, more preferably 0.2 mm to 0.6 mm.

[0121] Figure 8 1 is a cross-sectional view schematically showing a cutting process using an etching knife 122. Figure 8 As shown, the raw laminated film 150 is placed on the pad 160. At this time, one sheet of the raw laminated film 150 is placed in an orientation such that the optical laminated film 20 of the raw laminated film 150 is located on the pad 160 side and the diaphragm 32 side is located on the side away from the pad 160. The raw laminated film 150 can be placed in a stacked manner and multiple sheets can be punched at the same time. Thereafter, the etching knife 122 is inserted into the raw laminated film 150 from the diaphragm 32 side. When the etching knife 122 reaches the pad 160, the etching knife 122 is pulled out from the raw laminated film 150 to end the punching.

[0122] Figures 9 to 11 Each of them is a cross-sectional view schematically showing an example of the cross-sectional shape of the etching blade 122. Fig. 9 As shown, the etching blade 122 may be a so-called double-edged blade, that is, after cutting, the surface of the optical laminate film with the adhesive layer (hereinafter referred to as "surface A") and the surface on the opposite side (hereinafter referred to as "surface B") are both inclined relative to the vertical line (entry direction). Fig.10 As shown, the etching knife 122 can also be a so-called single-edged blade, that is, the A surface is parallel to the vertical line (entry direction), and only the B surface is inclined relative to the vertical line (entry direction). Fig.11 As shown, the etching knife 122 may also be a double-edged blade with the inclination angle of the A surface relative to the vertical line (entry direction) being different from the inclination angle of the B surface relative to the vertical line (entry direction).

[0123] The angle α1 of the A surface of the etching knife 122 relative to the vertical direction (entry direction) is preferably 0° to 20°. The angle α2 of the B surface of the etching knife 122 relative to the vertical direction (entry direction) is preferably 14° to 20°. The sum of the two angles (α1+α2) is preferably greater than 20° based on the point that the strength of the cutting knife is sufficient, and is preferably less than 40° based on the point that cutting is easy. The two angles (α1, α2) can be the same (α1=α2). In this case, the etching knife 122 is as follows: Fig. 9 The two angles (α1, α2) can also be different. In this case, the etching knife 122 can be as follows: Fig.10 The single blade with angle α1 of 0° is shown. Fig.11The double-edged blade is shown as α1<α2, but it can also be α1>α2. Generally, when the two angles (α1, α2) are different, α1<α2.

[0124] From the viewpoint of increasing the distance d, the angle α1 is preferably large. On the other hand, from the viewpoint of reducing damage (scratches, etc.) to the optical laminate film with an adhesive layer due to the entry of an etching blade during dicing, the angle α1 is preferably small.

[0125] During punching, the side surface having a protection region can be formed by allowing the etching knife 122 to enter from the side of the diaphragm 32. In addition, by adjusting the shape of the etching knife 122, the speed at which the etching knife 122 enters the original laminated film 150, etc., the distance d between the end position of the adhesive layer 31 and the end position of the polarizer layer 21 can be adjusted. The larger the angle (α1+α2) of the tip of the etching knife 122 is and the blunter the tip is, the larger the distance d can be.

[0126] The material of the backing plate 160 is not limited, and for example, a backing plate made of polypropylene can be used.

[0127] exist Figure 2 In the method for producing the optical laminate film 110 with a pressure-sensitive adhesive layer, the punching of the outer frame and the punching of the through-holes 51 may be performed simultaneously or at different times. From the viewpoint of improving the positional accuracy of the punching, it is preferable to perform them simultaneously.

[0128] In the method for manufacturing an optical laminate film with an adhesive layer, for the cutting step, the side is preferably formed by punching using an etching knife. In addition, a cutting method using a router and a punching method using a rotary cutting tool such as a drill may be combined.

[0129] [Image display device]

[0130] The optical laminated film with an adhesive layer can be used in an image display device. As the image display element used in the image display device, for example, a liquid crystal display element, an organic EL display element, etc. can be cited. When constructing a liquid crystal display device, the optical laminated film with an adhesive layer can be configured on the visible side for use, can be configured on the backlight side for use, and can also be used on both the visible side and the backlight side.

[0131] Example

[0132] The present invention will be described in further detail below using examples, but the present invention is not limited to these examples. "%" and "parts" in the examples are mass % and mass parts unless otherwise specified. Tests and measurements were performed as follows.

[0133] [Optical laminate film A with adhesive layer] (Example)

[0134] <Production process of raw material laminated film>

[0135] As shown below, Figure 4 The optical laminate film 130 with pressure-sensitive adhesive layers of the first embodiment shown is a raw laminate film having the same layer structure of “surface protection film 24 / first protection layer 22 / polarizer layer 21 / second protection layer 23 / pressure-sensitive adhesive layer 31 / separator 32”.

[0136] (Production of Polarizer Layer 21)

[0137] After dyeing a long strip of polyvinyl alcohol film in an aqueous solution containing iodine, the film is uniaxially stretched to 6 times in the length direction between rollers with different speed ratios in an aqueous solution containing boric acid to obtain a long strip of polarizing film layer having an absorption axis in the length direction. After stretching, the long strip of polarizing film layer is wound to form a roll. The visibility-corrected polarization degree of the polarizing film layer is about 99.995%, the visibility-corrected single transmittance is 42.7%, and the thickness is 12μm.

[0138] (Preparation of the First Protective Layer 22)

[0139] As the first protective layer 22 , a long triacetyl cellulose film with a hard coat layer (thickness 32 μm, manufactured by Toppan Printing Co., Ltd., trade name: 25KCHCN-TC) was prepared.

[0140] (Preparation of Second Protective Layer 23)

[0141] As the second protective layer 23 , a long cyclic polyolefin resin film (thickness 13 μm, Zeonor Film manufactured by Zeon Corporation of Japan, trade name: ZF14-013) was prepared.

[0142] (Lamination process)

[0143] After the polarizer layer 21, the first protective layer 22, and the second protective layer 23 prepared or produced as described above are cut into 300 mm × 400 mm, the first protective layer 22 and the second protective layer 23 are bonded to both sides of the polarizer layer 21 via a polyvinyl alcohol-based adhesive, and placed in an 80°C drying oven for 3 minutes. Then, after the surface of the second protective layer 23 is corona treated, an acrylic adhesive layer 31 (thickness 20 μm) with a separator 32 is laminated on the corona-treated side. Finally, a release film with a micro-adhesive as a surface protective film 24 is laminated on the surface of the first protective layer 22 to obtain an original laminated film. Corona treatment is performed using a corona discharge device manufactured by Kasuga Electric Co., Ltd. Specifically, a corona surface treatment rack "STR-1764", a high-frequency power supply "CT-0212", and a high-voltage transformer "CT-T02W" are used. This raw laminated film has a polyvinyl alcohol-based adhesive layer (thickness of 0.2 μm or less) interposed between the polarizer layer 21 and the first protective layer 22 , and also has a polyvinyl alcohol-based adhesive layer (thickness of 0.2 μm or less) interposed between the polarizer layer 21 and the second protective layer 22 .

[0144] <Cutting process>

[0145] A sheet of the obtained raw material laminated film (300 mm × 400 mm) was prepared as follows Figure 8 The etching knife is used to punch out Figure 3 The shape of the optical laminated film with an adhesive layer shown in the figure was obtained to obtain an optical laminated film A with an adhesive layer. As an etching knife, a Fig. 9 The double-edged etching knife with α1=α2=15° is shown. Figure 8 During the punching shown, the original laminated film 150 is placed in a direction such that the surface protection film 24 of the original laminated film is located on the side of the pad 160 and the diaphragm 32 is located on the side away from the pad 160, and the four corners are fixed to the pad 160 with a curing tape, so that the etching knife enters the original laminated film from the side of the diaphragm 32. Punching is performed in a manner such that the absorption axis of the polarizer layer 21 is parallel to the length direction of the optical laminated film A with an adhesive layer. It should be noted that the cutting knife uses a cutting knife that can move back and forth along the punching direction with a stroke of 24mm (sufficiently exceeding the thickness of the original laminated film) (set to "1 stroke"), and moves back and forth for 1 stroke in 1.5 seconds, and cuts the original laminated film 150 at the turning point of the reciprocating motion. As the pad 160, a pad obtained by overlapping one acrylic sheet (thickness 3.5mm) and one polypropylene sheet (thickness 1.0mm) is used. The backing plate 160 is used so that the polypropylene sheet side is in contact with the original laminated film 150 .

[0146] [Optical laminate film B with pressure-sensitive adhesive layer] (Comparative example)

[0147] <Production process of raw material laminated film>

[0148] A raw laminated film was produced by the same method as the production process of the optical laminated film A with a pressure-sensitive adhesive layer.

[0149] <Cutting process>

[0150] A sheet of the obtained raw material laminated film (300 mm × 400 mm) was prepared as follows Figure 8 The etching knife is used to punch out Figure 3 The shape of the optical laminated film with an adhesive layer shown above was used to obtain an optical laminated film B with an adhesive layer. Figure 8 During the punching shown, the original laminated film 150 is placed in a direction such that the diaphragm 32 of the original laminated film is located on the side of the pad 160 and the surface protection film 24 is located on the side away from the pad 160, and the four corners are fixed to the pad 160 with a curing tape, so that the etching knife enters the original laminated film from the side of the surface protection film 24. Punching is performed in a manner such that the absorption axis of the polarizer layer 21 is parallel to the length direction (length 400mm) of the optical laminated film B with an adhesive layer. It should be noted that the cutting knife uses a cutting knife that can move back and forth along the punching direction with a stroke of 24mm (sufficiently exceeding the thickness of the original laminated film) (set to "1 stroke"), and moves back and forth for 1 stroke in 1.5 seconds, and cuts the original laminated film 150 at the turning point of the reciprocating motion. As the pad 160, a pad obtained by overlapping one acrylic sheet (thickness 3.5mm) and one polypropylene sheet (thickness 1.0mm) is used. The backing plate 160 is used so that the polypropylene sheet side is in contact with the original laminated film 150 .

[0151] [Optical laminate film C with adhesive layer] (Example)

[0152] <Production process of raw material laminated film>

[0153] As shown below, Figure 5 The optical laminate film 140 with an adhesive layer of the second embodiment shown has the same layer structure as "surface protection film 24 / first protective layer 22 / polarizer layer 21 / second protective 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 / diaphragm 32" as the original laminate film.

[0154] (Production of Polarizer Layer 21)

[0155] After dyeing a long strip of polyvinyl alcohol film in an aqueous solution containing iodine, the film is uniaxially stretched to 6 times between rollers at different speed ratios in an aqueous solution containing boric acid to obtain a long strip of polarizing film having an absorption axis in the length direction. After stretching, the long strip of polarizing film is rolled up to form a roll. The visibility-corrected polarization degree of the polarizing film layer is about 99.995%, the visibility-corrected single transmittance is 42.7%, and the thickness is 12 μm.

[0156] (Preparation of the First Protective Layer 22)

[0157] As the first protective layer 22 , a long triacetyl cellulose film with a hard coat layer (thickness 32 μm, manufactured by Toppan Printing Co., Ltd., trade name: 25KCHCN-TC) was prepared.

[0158] (Preparation of Second Protective Layer 23)

[0159] As the second protective layer 23 , a long triacetyl cellulose film (thickness 40 μm, manufactured by Konica Minolta, trade name: KC4UYW) was prepared.

[0160] (Preparation of First Liquid Crystal Solidified Layer 26)

[0161] As the first liquid crystal solidified layer 26, a film (thickness 1 μm) consisting of a layer obtained by solidifying a nematic liquid crystal compound and an alignment film was prepared. The in-plane phase difference value Re(550) of the first liquid crystal solidified layer 26 was 140 nm, Re(450) / Re(550) was less than 1.0, and Re(650) / Re(550) was greater than 1.0. For the first liquid crystal solidified layer 26, the thrust force measured by the thrust force measurement method described later was 8.8 g / mm.

[0162] (Preparation of Second Liquid Crystal Solidified Layer 28)

[0163] As the second liquid crystal solidification layer 28, a film (thickness 2 μm) consisting of a layer obtained by solidifying a rod-shaped liquid crystal compound and an alignment film was prepared. The second liquid crystal solidification layer 28 satisfies the relationship Nz>Nx=Ny in its plane, and its in-plane phase difference value Re(550) is 0.6nm, and the phase difference value Rth(550) in the thickness direction is -69.6nm. For the second liquid crystal solidification layer 28, the thrust force measured by the thrust force measurement method described later is 38.1g / mm.

[0164] (Lamination process)

[0165] 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 made or prepared as described above are cut into 300mm×400mm, respectively, and the first protective layer 22 and the second protective layer 23 are bonded to both sides of the polarizer layer 21 via a polyvinyl alcohol-based adhesive, and placed in a drying oven at 80°C for 3 minutes. Then, after the surface of the second protective layer 23 side is corona treated, an acrylic adhesive (thickness 5μm) is laminated on the corona-treated surface as the first bonding layer 25. The laminate obtained in this way is called the first laminate. Corona treatment is 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" are used.

[0166] Then, a UV curing adhesive was applied to the surface of the first liquid crystal curing layer 26, and the second liquid crystal curing layer 28 was attached. An ultraviolet irradiation device (manufactured by FUSION UV SYSTEMS Co., Ltd.) was used from the second liquid crystal curing layer 28 side to irradiate the surface of the first liquid crystal curing layer 26 at a cumulative light intensity of 400 mJ / cm 2 (UV-B) Irradiate with ultraviolet rays to cure the adhesive. The laminated body having the laminated structure of "first liquid crystal cured layer 26 / second bonding layer 27 composed of an adhesive layer / second liquid crystal cured layer 28" obtained in this manner is referred to as a second laminated body.

[0167] The first laminate and the second laminate obtained as described above are laminated so that the first laminating layer 25 of the first laminate and the first liquid crystal solidified layer 26 of the second laminate are laminated. At this time, the slow axis of the first liquid crystal solidified layer 26 forms an angle of -45° with respect to the absorption axis of the polarizer layer 31.

[0168] Then, an acrylic adhesive layer 31 (thickness 20 μm) with a separator 32 bonded thereto was laminated on the surface of the second liquid crystal solidified layer 28. Finally, a release film with a slight adhesive was laminated on the surface of the first protective layer 22 as a surface protective film 24 to obtain an original laminated film.

[0169] <Cutting process>

[0170] A sheet of the obtained raw material laminated film (300 mm × 400 mm) was prepared as follows Figure 8 The etching knife is used to punch out Figure 3 The shape of the optical laminated film with an adhesive layer shown above was used to obtain an optical laminated film C with an adhesive layer. Figure 8During the punching shown, the original laminated film 150 is placed in a direction such that the surface protection film 24 of the original laminated film is located on the pad 160 side and the diaphragm 32 is located on the side away from the pad 160, and the four corners are fixed to the pad 160 with a curing tape, so that the etching knife enters the original laminated film from the diaphragm 32 side. Punching is performed in a manner such that the absorption axis (stretching direction) of the polarizer layer 21 is parallel to the length direction (400mm) of the optical laminated film C with an adhesive layer. It should be noted that the cutting knife uses a cutting knife that can move back and forth along the punching direction with a stroke of 24mm (sufficiently exceeding the thickness of the original laminated film) (hereinafter referred to as "1 stroke"), and moves back and forth for 1 stroke in 1.5 seconds, and cuts the original laminated film 150 at the turning point of the reciprocating motion. As the pad 160, a pad obtained by overlapping one acrylic sheet (thickness 3.5mm) and one polypropylene sheet (thickness 1.0mm) is used. The backing plate 160 is used so that the polypropylene sheet side is in contact with the original laminated film 150 .

[0171] [Optical laminated film D with adhesive layer] (Comparative example)

[0172] <Production process of raw material laminated film>

[0173] A raw laminated film was produced by the same method as the production process of the optical laminated film D with a pressure-sensitive adhesive layer.

[0174] <Blanking process>

[0175] A sheet of the obtained raw material laminated film (300 mm × 400 mm) was prepared as follows Figure 8 The etching knife is used to punch out Figure 3 Sample 4 was obtained by adopting the shape of the optical laminated film with the adhesive layer shown in FIG. Figure 8 During the punching shown, the original laminated film 150 is placed in a direction such that the diaphragm 32 of the original laminated film is located on the side of the pad 160 and the surface protection film 24 is located on the side away from the pad 160, and the four corners are fixed to the pad 160 with a curing tape, so that the etching knife enters the original laminated film from the side of the surface protection film 24. Punching is performed in a manner such that the absorption axis of the polarizer layer 21 is parallel to the length direction (400mm) of the optical laminated film D with an adhesive layer. It should be noted that the cutting knife uses a cutting knife that can move back and forth along the punching direction with a stroke of 24mm (sufficiently exceeding the thickness of the original laminated film) (hereinafter referred to as "1 stroke"), and moves back and forth for 1 stroke in 1.5 seconds, and cuts the original laminated film 150 at the turning point of the reciprocating motion. As the pad 160, a pad obtained by overlapping one acrylic sheet (thickness 3.5mm) and one polypropylene sheet (thickness 1.0mm) is used. The backing plate 160 is used so that the polypropylene sheet side is in contact with the original laminated film 150 .

[0176] [Side view]

[0177] About the optical laminated films AD with pressure-sensitive adhesive layers, the cross-sectional shapes of the starting positions of the curved surface regions on the side surfaces were observed with an optical microscope. Fig.12 (a) and (b) schematically show images of the pressure-sensitive adhesive layer-attached optical layered films A and B observed using an optical microscope. Fig.13 (a) and (b) schematically show images of the pressure-sensitive adhesive layer-attached optical layered films C and D observed using an optical microscope.

[0178] from Fig.12 , Fig.13 It can be seen that the adhesive layer 31 on the side of the optical laminated film A and C with an adhesive layer protrudes outward compared to the end position of the polarizer layer 21 and warps toward the polarizer layer 21 side. That is, a protective area is formed. On the other hand, in the side of the optical laminated film B and D with an adhesive layer, although the adhesive layer 31 protrudes outward compared to the end position of the polarizer layer 21, it warps to the side opposite to the polarizer layer 21. That is, there is no protective area. It should be noted that the distance d between the end position of the adhesive layer 31 of the optical laminated film A with an adhesive layer and the end position of the polarizer layer 21 of the optical laminated film D with an adhesive layer is 15 μm. In addition, the optical laminated film A with an adhesive layer and the optical laminated film D with an adhesive layer did not observe the polyvinyl alcohol-based adhesive layer sandwiched between the polarizer layer 21 and the first protective layer 22, and the polyvinyl alcohol-based adhesive layer sandwiched between the polarizer layer 21 and the second protective layer 23. In the optical laminate film C with adhesive layer and the optical laminate film D with adhesive layer, the first laminating layer 25, the second liquid crystal cured layer 26, the second laminating layer 27 and the second liquid crystal cured layer 28 are not respectively identifiable and observed, but are integrated layers ( Fig.13 (a) (b) is observed in the form of layer 29).

[0179] [Thermal shock test]

[0180] The optical laminated films A to D with pressure-sensitive adhesive layers were bonded to the surface of alkali-free glass (EAGLE XG manufactured by Corning, 120×200×0.7 mm) which had been thoroughly cleaned with ethanol, and then autoclaved at 50° C. and 0.5 MPa (gauge pressure) for 20 minutes. The obtained products were used as evaluation samples.

[0181] The evaluation sample was placed in a heat shock test tank, and heat stimulation was applied at -40°C and 85°C in cycles of 30 minutes each. Heat stimulation from low temperature to high temperature was defined as one cycle, and each sample was tested for a total of 100 cycles.

[0182] [Crack Evaluation]

[0183] The generation of cracks in the evaluation sample after the 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 generated cracks is shown in FIG. Fig.14 This figure (optical microscope image) is an optical microscope image observed from the upper surface of a specific region common to the optical laminate films A and B with adhesive layers. Cracks generated from the curved surface region defined in a manner that is the same range for each evaluation sample were observed, and the cracks were classified as shown below based on the length of the cracks, and the number of cracks contained in each classification was measured. The results are shown in Table 1.

[0184] Short crack: Cracks less than 100 μm in length

[0185] Medium crack: A crack with a length of 100 μm or more and less than 200 μm

[0186] Long crack: Crack with a length of more than 200 μm

[0187]

Table 1

[0188] Punching direction Presence of protected areas Short crack Medium Crack Long crack Optical laminated film A with adhesive layer From the SP side have 0 0 0 Optical laminated film B with adhesive layer From the Pf side none 5 1 2 Optical laminated film C with adhesive layer From the SP side have 0 0 0 Optical laminate film D with adhesive layer From the Pf side none 2 3 2

[0189] As shown in Table 1, the optical laminate films A and C with pressure-sensitive adhesive layers of the present invention did not generate cracks even after 100 cycles of the heat shock test.

[0190] [Measurement of push force]

[0191] A triacetyl cellulose film with a thickness of 60 μm was prepared as sample A, a triacetyl cellulose film with a thickness of 20 μm was prepared as sample B, a cycloolefin polymer film with a thickness of 23 μm was prepared as sample C, and a first liquid crystal solidified layer 26 and a second liquid crystal solidified layer 28 were prepared when preparing optical laminated films C and D with adhesive layers as samples D and E, and the pushing force of each sample was measured using the following method.

[0192] like Fig.15 As shown in the top view shown in (a) and the cross-sectional view shown in (b), each sample 170 was cut into a 30 mm × 30 mm rectangle and attached to a backing paper 171 (85 μm thick, 30 mm × 30 mm rectangle) having a 10 mm × 10 mm rectangular opening 171a at the center, with the opening 171a blocked via a 25 μm thick adhesive layer 172. Thereafter, an iron rod 173 having a tip diameter of 1.0 mm was pressed in from above the sample 170 side of the blocked opening 171a at a speed of 0.33 mm / s, and the pushing force relative to the deformation in the thickness direction was measured using a portable compression tester (KEN-G5, manufactured by Katotech Co., Ltd.). Fig.16 Table 2 shows the measurement results. Fig.16 The slope of the pushing force calculated from the measurement results.

[0193]

Table 2

[0194] Push force slope (g / mm) Sample A (TAC, thickness 60 μm) 477.05 Sample B (TAC, thickness 20 μm) 266.55 Sample C (COP, thickness 23 μm) 226.65 Sample D (liquid crystal cured layer) 8.8 Sample E (liquid crystal cured layer) 38.1

Claims

1. An optical laminated film with an adhesive layer, which is an optical laminated film with an adhesive layer having an optical laminated film and an adhesive layer in this order, wherein the optical laminated film comprises a polarizer layer to which a dichroic dye is adsorbed and oriented, The optical laminate film with an adhesive layer has a through hole or a concave portion at the outer edge. The optical laminate film includes a protective layer on the side opposite to the pressure-sensitive adhesive layer when viewed from the polarizer layer, wherein the protective layer includes a hard coating layer constituting a surface on the side opposite to the polarizer layer side. At least a portion of a side surface of the optical laminate film with an adhesive layer is a protection region in which the adhesive layer protrudes outward from an end position of the polarizer layer and rises toward the polarizer layer.

2. The optical laminate film with an adhesive layer according to claim 1, wherein At least a portion of the side surface of the optical laminate film with an adhesive layer is a curved surface region, that is, the contour of the surface of the optical laminate film on the side opposite to the adhesive layer side is a curved line. At least a portion of the curved surface area is the protection area.

3. The optical laminate film with an adhesive layer according to claim 2, wherein: The protective region in the curved surface region includes a portion where an angle θ between the contour and the absorption axis direction of the polarizing plate layer changes continuously, and the angle θ is greater than 0° and equal to or less than 90°. 4 . The optical laminated film with a pressure-sensitive adhesive layer according to claim 1 , wherein: The protection area is a cutting surface.

5. The optical laminated film with a pressure-sensitive adhesive layer according to any one of claims 1 to 3, wherein The protective region includes a region where a distance d between an end position of the pressure-sensitive adhesive layer and an end position of the polarizer layer is 10 μm or more. 6 . The optical laminated film with a pressure-sensitive adhesive layer according to claim 1 , further comprising a separator releasably bonded to a surface of the pressure-sensitive adhesive layer on the side opposite to the optical laminated film side.

7. The optical laminated film with a pressure-sensitive adhesive layer according to any one of claims 1 to 3, wherein The optical laminate film includes a liquid crystal cured layer including a polymerized cured product of a polymerizable liquid crystal compound.

8. The optical laminated film with a pressure-sensitive adhesive layer according to any one of claims 1 to 3, wherein The adhesive layer is an adhesive layer for bonding to an adherend.

9. A method for producing an optical laminated film with an adhesive layer, comprising: A step of preparing a raw laminate film, the raw laminate film comprising, in order, an optical laminate film including a polarizer layer on which a dichroic dye is adsorbed and oriented, an adhesive layer, and a separator releasably bonded to the adhesive layer; and a cutting step, wherein an etching knife enters the original material laminate film from the diaphragm side to cut the original material laminate film and form a side surface; At least a portion of the side surface is a protection region in which the pressure-sensitive adhesive layer protrudes outward from an end position of the polarizing plate layer and rises toward the polarizing plate layer.

10. The method for producing an optical laminated film with an adhesive layer according to claim 9, wherein: The etching knife used had a tip angle of 25° to 35° and a body thickness of 0.2 mm to 0.6 mm.

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