JP2021105716A - Laminated optical film with adhesive layer and manufacturing method therefor - Google Patents

Abstract

To provide a laminated optical film with an adhesive layer, which is less susceptible to cracking.SOLUTION: A laminated optical film with an adhesive layer is provided, comprising a laminated optical film including a polarizer layer having a dichroic pigment absorbed and aligned therein and an adhesive layer stacked in the described order. At least a portion of a side face of the laminated optical film with an adhesive layer forms a protective region where the adhesive layer protrudes outward from an edge of the polarizer layer and is warped upward toward the polarizer layer.SELECTED DRAWING: Figure 1

Description

The present invention relates to an optical laminated film with an adhesive layer and a method for producing the same.

In recent years, the design of image display devices has been diversified. Under the influence of this trend, optical laminated films including linearly polarizing films are also required to support various shapes. Japanese Unexamined Patent Publication No. 2018-25630 discloses a polarizing plate having a concave portion on an outer edge portion and a polarizing plate having a through hole in the plane.

Japanese Unexamined Patent Publication No. 2018-25630

The optical laminated film having a concave portion on the outer edge portion and the optical laminated film having a through hole in the surface have a problem that cracks are likely to occur.

An object of the present invention is to provide an optical laminated film with an adhesive layer in which the occurrence of cracks is suppressed, and a method for producing the same.

The present invention provides the following optical laminated film with an adhesive layer and a method for producing an optical laminated film with an adhesive layer.

[1] An optical laminated film with an adhesive layer having an optically laminated film containing a polarizing element layer in which a dichroic dye is adsorbed and oriented, and an adhesive layer in this order.
At least a part of the side surface of the optical laminated film with the pressure-sensitive adhesive layer is a protective region in which the pressure-sensitive adhesive layer protrudes outward from the most extreme position of the polarizer layer and warps toward the polarizer layer. , Optical laminated film with adhesive layer.

[2] At least a part of the side surface of the optical laminated film with the pressure-sensitive adhesive layer is a curved surface region in which the contour of the surface of the optical laminated film on the side opposite to the pressure-sensitive adhesive layer side is curved.
The optical laminated film with an adhesive layer according to [1], wherein at least a part of the curved surface region is the protective region.

[3] The protected region in the curved surface region includes a portion where 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 more than 0 ° and 90 ° or less. The optical laminated film with an adhesive layer according to [2].

[4] The optical laminated film with an adhesive layer according to any one of [1] to [3], wherein the protective region is a cut surface.

[5] Any one of [1] to [4], the protective region includes a region where the distance d between the end position of the pressure-sensitive adhesive layer and the end position of the polarizer layer is 10 μm or more. The optical laminated film with an adhesive layer according to item 1.

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

[7] The optical laminated film with an adhesive layer according to any one of [1] to [6], wherein the optical laminated film contains a liquid crystal cured layer made of a polymerized cured product of a polymerizable liquid crystal compound.

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

[9] A raw fabric laminated film having an optical laminated film including a polarizing element layer in which a dichroic dye is adsorbed and oriented, an adhesive layer, and a separate film detachably bonded to the adhesive layer in this order. And the process of preparing
A method for producing an optical laminated film with an adhesive layer, which comprises a cutting step of inserting a corrosive blade into the raw fabric laminated film from the separate film side to cut the raw fabric laminated film to form a side surface.

[10] At least a part of the side surface is a protective region in which the pressure-sensitive adhesive layer protrudes outward from the most extreme position of the polarizer layer and warps toward the polarizer layer, [9]. The method for producing an optical laminated film with an adhesive layer according to the above method.

According to the present invention, it is possible to provide an optical laminated film with an adhesive layer in which the occurrence of cracks is suppressed.

It is schematic cross-sectional view which shows typically an example of the optical laminated film with an adhesive layer of this invention. It is a top view which shows an example of the optical laminated film with an adhesive layer which has a curved surface region on the side surface. It is a top view which shows another example of the optical laminated film with an adhesive layer which has a curved surface region on the side surface. It is the schematic sectional drawing which shows typically the optical laminated film with the pressure-sensitive adhesive layer of 1st Embodiment. It is the schematic sectional drawing which shows typically the optical laminated film with the pressure-sensitive adhesive layer of 2nd Embodiment. It is a top view which shows an example of a corrosive blade type. A cross-sectional view of the corroded blade shown in FIG. 6 is shown. It is sectional drawing which shows typically the cutting process which concerns on the manufacturing method of this invention. It is sectional drawing which shows typically an example of the cross-sectional shape of a corrosive blade. It is sectional drawing which shows typically an example of the cross-sectional shape of a corrosive blade. It is sectional drawing which shows typically an example of the cross-sectional shape of a corrosive blade. It is sectional drawing which shows typically the observation image which observed the cross section of the optical laminated film A, B with an adhesive layer by the optical microscope image. It is sectional drawing which shows typically the observation image which observed the cross section of the optical laminated film C, D with an adhesive layer by the optical microscope image. It is an optical microscope image which shows the upper surface of the optical laminated film A, B with an adhesive layer. It is a schematic diagram which shows the measuring method of a pushing force. It is a figure which shows the measurement result of the pushing force.

[Optical laminated film with adhesive layer]
FIG. 1 is a schematic cross-sectional view schematically showing an example of an optical laminated film with an adhesive layer of the present invention. As shown in FIG. 1, the optical laminated film 100 with an adhesive layer has an optical laminated film 20 including a polarizing element layer 21 in which a dichroic dye is adsorbed and oriented, and an adhesive layer 31 in this order.

At least a part of the side surface of the optical laminated film 100 with an adhesive layer is a protective region. As used herein, the "protected area" means a side area in which the pressure-sensitive adhesive layer 31 projects outward from the most extreme position of the polarizer layer 21 and warps toward the polarizer layer 21. Regarding the range of the "side area" in the present specification, all the positions arranged in the stacking direction on the side surface are included in the same area. In the present specification, the fact that the adhesive layer 31 is warped toward the polarizer layer 21 means that the protruding portion of the pressure-sensitive adhesive layer 31 has a portion closer to the polarizer layer 21 side as compared with other portions. do. Even if the protruding portion of the pressure-sensitive adhesive layer 31 is close to the polarizer layer 21 side and the pressure-sensitive adhesive layer 31 is in contact with all the side surfaces of the polarizer layer 21 or a part of the side surface of the polarizer layer 21. Alternatively, as shown in FIG. 1, the pressure-sensitive adhesive layer 31 may be curved toward the polarizer layer 21 side without contacting the side surface of the polarizer layer 21. The side area 100a shown in FIG. 1 is a protected area.

The optical laminated film 100 with an adhesive layer has a protective region 100a on the side surface, so that the occurrence of cracks can be suppressed. In the protective region 100a, since the side surface of the optical laminated film 20 is protected by the pressure-sensitive adhesive layer 31, it is presumed that the occurrence of cracks is suppressed. Cracks are likely to occur from the side surface or the vicinity of the side surface.

At least a part of the side surface of the optical laminated film 100 with an adhesive layer may be a protective region 100a, but from the viewpoint of suppressing the occurrence of cracks, it is preferable that the proportion of the region that is the protective region 100a is high. Alternatively, the side area where cracks are likely to occur is preferably the protected area 100a. For example, a region of 10% or more of the entire side surface of the optical laminated film 100 with an adhesive layer is a protective region 100a. Alternatively, for example, at least a part of the curved surface region on the side surface of the optical laminated film 100 with the adhesive layer includes the protective region 100a, and 50% or more of the total region of the curved surface region is the protective region 100a.

In the present specification, the “curved surface region” means a side region having a curved contour on the surface 20a on the side opposite to the pressure-sensitive adhesive layer 31 side of the optical laminated film 20. The "curve" as used herein means that the angle θ formed by the polarizing element layer 21 with respect to the absorption axis direction continuously changes. In the curved surface region, cracks are likely to occur starting from the side surface or the vicinity of the side surface.

FIG. 2 is a top view showing an example of an adhesive layer optical laminated film having a curved surface region on the side surface. FIG. 2 is a top view of the optical laminated film 110 with an adhesive layer as viewed from the surface opposite to the adhesive layer side. The optical laminated film 110 with an adhesive layer shown in FIG. 2 has a square shape with rounded corners and has through holes 51. The rounded square shape means 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 is rounded. In the optical laminated film 110 with an adhesive layer, all the corners 52 are rounded. The optical laminated film 110 with an adhesive layer shown in FIG. 2 has a curved surface region on the inner wall of the through hole 51 and the side surface of the corner portion 52. For the contour of the curved surface region, the angle θ formed by the direction of the absorption axis of the polarizer layer changes continuously.

FIG. 3 is a top view showing another example of the optical laminated film with an adhesive layer having a curved surface region on the side surface. FIG. 3 is a top view of the optical laminated film 120 with an adhesive layer as viewed from the surface on the side opposite to the adhesive layer side. The optical laminated film 120 with an adhesive layer shown in FIG. 3 has a square shape with rounded corners and has a concave portion 53 on the outer edge. The optical laminated film 120 with an adhesive layer shown in FIG. 3 has a curved surface region on the side surface of the concave portion 53 and the corner portion 52 on the outer edge. In the contour of the curved surface region, the angle θ formed by the absorption axis of the polarizer layer changes continuously.

The optical laminated film with the pressure-sensitive adhesive layer may have a square shape with rounded corners as shown in FIGS. 2 and 3 in a plan view, or may have a square shape. The square shape means a shape in which none of the four corners is rounded. Further, in the present specification, the square shape means a rectangular shape or a square shape.

The contour of the side surface on the surface 20a has an angle θ formed by the polarizing element layer 31 with respect to the absorption axis direction of 0 ° to 90 °, and a region in which the angle θ continuously changes is defined as a curved surface region. The curved surface region includes a portion where the angle θ is more than 0 ° and 90 ° or less. This is because the curved surface region including such a portion is likely to have cracks starting from the side surface or the vicinity of the side surface, and therefore the effect of suppressing the generation of cracks according to the present invention becomes more remarkable.

FIG. 1 shows a distance d between the end position of the pressure-sensitive adhesive layer 31 and the end position of the polarizer layer 21 in the protective region 100a of the optical laminated film 100 with the pressure-sensitive adhesive layer. The protected region 100a preferably includes a region having a distance d of 10 μm or more, and more preferably a region having a distance d of 15 μm or more. In such a region, it becomes easier to suppress the occurrence of cracks. In the protected region 100a, the distance d between the end position of the pressure-sensitive adhesive layer 31 and the end position of the polarizer layer 21 is, for example, 30 μm or less.

In the optical laminated film 100 with an adhesive layer, the side surface having the protective region 100a is, for example, a cut surface formed by cutting the laminated body with a cutting blade. By adjusting the cutting blade used for cutting, the cutting direction, the cutting speed, the in-plane tension applied to the laminated body at the time of cutting, etc., the pressure-sensitive adhesive layer 31 protrudes outward from the most extreme position of the polarizer layer 21 and is a polarizer layer. It is possible to form a side surface having a protective area that is curved toward the 21 side. When a corrosive blade (pinnacle blade) whose tip is formed by etching is used as the cutting blade, the adhesive layer 31 protrudes and warps to form the protective region 100a. Further, even if the cutting speed, that is, the approaching speed when the cutting blade is made to enter the laminated body is increased, the protective region 100a can be formed in the same manner. By increasing the in-plane tension applied to the laminated body, the protective region 100a can be formed. In order to increase the in-plane tension, for example, the pressure for sandwiching the laminated body at the time of cutting may be increased.

The pressure-sensitive adhesive layer 31 is used, for example, as a pressure-sensitive adhesive layer for bonding the optical laminated film 20 to an image display element such as a liquid crystal cell or an organic EL display element, or an adherend such as another optical member. The optical laminated film 100 with an adhesive layer may have a separate film peelably bonded to the surface of the adhesive layer 31 on the side opposite to the optical laminated film 20 side.

The optical laminated film 20 may include another layer different from the polarizer layer 21, and examples of the other layer include a protective layer, a liquid crystal curing layer, a retardation layer, and a bonding layer. The optical laminated film 20 may have a protective layer on the side opposite to the pressure-sensitive adhesive layer 31 side when viewed from the polarizing layer 31, and the protective layer has a surface on the side opposite to the polarizing layer 21 side. It may include a constituent hard coat layer.

<First Embodiment>
FIG. 4 is a schematic cross-sectional view schematically showing the optical laminated film with an adhesive layer of the first embodiment. As shown in FIG. 4, the optical laminated film 130 with an adhesive layer has an optical laminated film 20 and an adhesive layer 31 in this order, and is on the surface of the adhesive layer 31 opposite to the optical laminated film 20 side. Further, it has a separate film 32 that is peelably bonded.

The optical laminated film 20 has a surface protective film 24, a first protective layer 22, a polarizer layer 21, and a second protective layer 23 in this order. The first protective layer 22 includes a hard coat layer forming a surface opposite to the pressure-sensitive adhesive layer 31 side, and a surface protective film 24 is detachably bonded to the surface of the hard coat layer.

In the optical laminated film 130 with an adhesive layer, the side area 130a shown in FIG. 4 is a protective area. In the protective region 130a, the pressure-sensitive adhesive layer 31 protrudes outward from the most extreme position of the polarizer layer 21 and warps toward the polarizer layer 21.

<Second embodiment>
FIG. 5 is a schematic cross-sectional view schematically showing the optical laminated film with an adhesive layer of the second embodiment. As shown in FIG. 5, the optical laminated film 140 with an adhesive layer has an optical laminated film 20 and an adhesive layer 31 in this order, and is on the surface of the adhesive layer 31 opposite to the optical laminated film 20 side. Further, it has a separate film 32 that is peelably bonded.

The optical laminated film 20 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, and a second. The bonded layer 27 and the second liquid crystal cured layer 28 are provided in this order. The first protective layer 22 includes a hard coat layer forming a surface opposite to the pressure-sensitive adhesive layer 31 side, and a surface protective film 24 is detachably bonded to the surface of the hard coat layer.

In the optical laminated film 140 with an adhesive layer, the side area 140a shown in FIG. 5 is a protective area. In the protective region 140a, the pressure-sensitive adhesive layer 31 protrudes outward from the most extreme position of the polarizer layer 21 and warps toward the polarizer layer 21.

In the protective region 140a of the optical laminated film 140 with the pressure-sensitive adhesive layer, layers other than the pressure-sensitive adhesive layer 31 may also protrude outward from the most extreme position of the polarizing element layer 21, similarly to the pressure-sensitive adhesive layer 31. Further, the shape may be warped toward the polarizer layer 21 side. In FIG. 5, in the protective region 140a, in addition to the pressure-sensitive adhesive layer 31, the first bonding layer 25, the first liquid crystal curing layer 26, and the second liquid crystal curing layer 28 are formed in the same manner as the pressure-sensitive adhesive layer 31. , The case where the shape protrudes outward from the most extreme position of the polarizer layer 21 and warps toward the polarizer layer 21 is shown. On the side surface, which is the cut surface, the behavior when the cutting blade is inserted is similar to that of the pressure-sensitive adhesive layer 31 in the layer in which the inclination of the pushing force measured by the test method of the examples described later is 50 g / mm or less. Therefore, it is presumed that, like the pressure-sensitive adhesive layer 31, the shape tends to protrude outward from the most extreme position of the polarizer layer 21 and further warp toward the polarizer layer 21 side.

The optical laminated film with an adhesive layer according to the present invention may include a layer having a pushing force inclination of 50 g / mm or less.

Hereinafter, the materials and the like of each layer forming the optical laminated film with the adhesive layer will be described in detail.

(Optical Laminated Film 20)
The optical laminated film 20 includes a polarizer layer 21. The thickness of the optical laminated film 20 can usually be 5 μm or more and 200 μm or less, and may be 150 μm or less, or 120 μm or less.

(Polarizer layer 21)
Examples of the polarizer layer 21 include a stretched film or a stretched layer on which a dye having absorption anisotropy is adsorbed, a layer obtained by applying and curing a dye having absorption anisotropy, and the like. Examples of the dye having absorption anisotropy include a dichroic dye. Specifically, as the dichroic dye, iodine or a dichroic organic dye is used. For dichroic organic dyes, C.I. I. Included are dichroic direct dyes made of disuazo compounds such as DIRECT RED 39 and dichroic direct dyes made of compounds such as trisazo and tetrakisazo.

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.

(1) Stretched film or polarizing layer as a stretched layer As the polarizing layer formed by applying and curing a dye having absorption anisotropy, a composition containing a dichroic dye having a liquid crystal crystal or a dichroic dye. Examples thereof include a polarizer layer containing a cured product of a polymerizable liquid crystal compound, such as a layer obtained by applying and curing a composition containing a polymerizable liquid crystal and a polymerizable liquid crystal. A polarizer layer obtained by applying and curing a dye having an absorption anisotropy is preferable because there is no limitation in the bending direction as compared with a stretched film or a stretched layer on which a dye having an absorption anisotropy is adsorbed.

The polarizer layer, which is a stretched film on which a dye having absorption anisotropy is adsorbed, is usually obtained by dyeing the polyvinyl alcohol-based resin film with a dichroic dye in a step of uniaxially stretching the polyvinyl alcohol-based resin film. It can be produced through a step of adsorbing a dichroic dye, a step of treating a polyvinyl alcohol-based resin film on which the dichroic dye is adsorbed with an aqueous boric acid solution, and a step of washing with water after the treatment with the aqueous boric acid solution.

The polyvinyl alcohol-based resin is obtained by saponifying the polyvinyl acetate-based resin. As the polyvinyl acetate-based resin, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable therewith is 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.

The saponification degree of the polyvinyl alcohol-based resin is usually about 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 can also be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually 1,000 or more and 10,000 or less, preferably 1,500 or more and 5,000 or less.

The polarizer layer, which is a stretched layer on which a dye having absorption anisotropy is adsorbed, is usually a step of applying a coating liquid containing the polyvinyl alcohol-based resin on a base film, and uniaxially stretching the obtained laminated film. Step, A step of dyeing a polyvinyl alcohol-based resin layer of a uniaxially stretched laminated film with a bicolor dye to adsorb the bicolor dye to form a polarizer layer, a film on which the bicolor dye is adsorbed. Can be produced through a step of treating with an aqueous boric acid solution and a step of washing with water after the treatment with the aqueous boric acid solution. If necessary, the base film may be peeled off from the polarizer layer. As the material of the base film, the same material as the base film of the surface protection film 24 described later is exemplified.

(2) Polarizer layer formed by applying and curing a dye having absorption anisotropy The polarizing layer layer formed by applying and curing a dye having absorption anisotropy is a liquid crystalline, polymerizable dichroic layer. Examples thereof include a polarizer layer containing a cured product of a polymerizable liquid crystal compound, such as a layer obtained by applying a composition containing a dye or a composition containing a dichroic dye and a polymerizable liquid crystal to a base film and curing the mixture. If necessary, the base film may be peeled off from the polarizer layer. As the material of the base film, the same material as the base film of the surface protection film 24 described later is exemplified.

(1st protective layer 22, 2nd protective layer 23)
The optical laminated film 20 can include a first protective layer 22 laminated on the surface of the polarizer layer 21 opposite to the pressure-sensitive adhesive layer 31 side, and the surface of the polarizer layer 21 on the pressure-sensitive adhesive layer 31 side. The second protective layer 23 laminated on the surface can be included. The first protective layer 22 and the second protective layer 23 are optically transparent thermoplastic resins, for example, polyolefins such as chain polyolefin resins (polypropylene resins and the like) and cyclic polyolefin resins (norbornene resins and the like). Based resin; Cellular resin such as triacetyl cellulose and diacetyl cellulose; Polyester based resin such as polyethylene terephthalate and polybutylene terephthalate; Polycarbonate resin; (Meta) acrylic resin such as methyl methacrylate resin; Polystyrene based Resin; Polyvinyl chloride resin; Acrylonitrile / butadiene / styrene resin; Acrylonitrile / styrene resin; Polyvinyl acetate resin; Polyvinylidene chloride resin; Polyamide resin; Polyacetal resin; Modified polyphenylene ether resin; Polysulfone system Resin; polyether sulfone-based resin; polyarylate-based resin; polyamideimide-based resin; polyimide-based resin; a coating layer or film composed of one or a mixture of two or more of these can be used. The thickness of the protective layer is usually 1 μm or more and 100 μm or less, may be 5 μm or more and 80 μm or less, 60 μm or less, or 50 μm or less.

The protective film can be attached to the polarizer layer 21 via, for example, an adhesive layer. Examples of the adhesive forming the adhesive layer include a water-based adhesive, an active energy ray-curable adhesive, and a thermosetting adhesive, and a water-based adhesive and an active energy ray-curable adhesive may be used. preferable.

The two opposing surfaces bonded 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.

The first protective layer 22 and the second protective layer 23 may be a protective layer made of the same material or a protective layer made of different materials. The first protective layer 22 has an optical functional layer such as an antiglare layer, a light diffusion layer, a retardation layer, and an antireflection layer, and a surface treatment layer such as a hard coat layer, an antistatic layer, and an antifouling layer on the surface thereof. May be provided. When the first protective layer 22 has a hard coat layer, cracks are likely to occur, but according to the present invention, the occurrence of cracks can be suppressed even with such a configuration.

(Surface protection film 24)
The optical laminated film 20 can include a surface protective film 24 that constitutes a surface opposite to the surface on the pressure-sensitive adhesive layer 31 side. The surface protective film 24 is peeled off and removed together with the pressure-sensitive adhesive layer that the surface-protecting film 24 has, for example, after the optical laminated film with the pressure-sensitive adhesive layer is bonded to an image display element or another optical member.

The surface protective film 24 has a base film and an adhesive layer. The thickness of the surface protective 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.

The resin forming the base film is, for example, a chain polyolefin resin such as polyethylene or polypropylene; a cyclic polyolefin resin such as norbornene resin; a polyester resin such as polyethylene terephthalate or polyethylene naphthalate; a polycarbonate resin; It can be a thermoplastic resin such as one or a mixture of two or more of these. The base material layer may have a single-layer structure or a multi-layer structure, but is preferably a single-layer structure from the viewpoint of ease of manufacture, production cost, and the like. The base material layer may be a uniaxially stretched film or a biaxially stretched film, but is preferably a biaxially stretched film from the viewpoint of the mechanical strength of the film, ease of production, production cost, and the like. Is preferable.

The pressure-sensitive adhesive layer can be composed of a pressure-sensitive adhesive composition containing a resin as a main component, such as (meth) acrylic-based, rubber-based, urethane-based, ester-based, silicone-based, and polyvinyl ether-based. Among them, a pressure-sensitive adhesive composition using a (meth) acrylic resin having excellent transparency, weather resistance, heat resistance and the like as a base polymer is preferable. The pressure-sensitive adhesive composition may be an active energy ray-curable type or a thermosetting type.

(1st liquid crystal cured layer 26, 2nd liquid crystal cured layer 28)
The optical laminated film 20 may include one layer or two or more liquid crystal cured layers made of a polymerized cured product of a polymerizable liquid crystal compound. The optical laminated film 140 with a bonding layer of the second embodiment includes the first liquid crystal curing layer 26 and the second liquid crystal curing layer 28 as the liquid crystal curing layer. Examples of the liquid crystal cured layer include those that function as a retardation layer. The liquid crystal cured layer can be formed by applying a composition containing a polymerizable liquid crystal compound to a base film and curing it. An orientation layer may be formed between the base film and the coating layer. The liquid crystal cured layer may be incorporated into the optical laminated film 20 in the form of having an alignment layer and / or a base film.

The liquid crystal cured layer can be formed by using a known polymerizable liquid crystal compound. The type of the liquid crystal compound is not particularly limited, and a rod-shaped liquid crystal compound, a disk-shaped liquid crystal compound, and a mixture thereof can be used. Examples of the polymerizable liquid crystal compound include JP-A-11-513019, JP-A-2005-289980, JP-A-2007-108732, JP-A-2010-2404038, and JP-A-2010-31223. Described in JP-A-2010-270108, JP-A-2011-6360, JP-A-2011-207765, JP-A-2016-81035, WO2017 / 043438 and JP-A-2011-207765. Examples include polymerizable liquid crystal compounds.

For example, a liquid crystal cured layer can be formed by applying a composition containing a polymerizable liquid crystal compound on an alignment layer to form a coating film and curing the coating film. The thickness of the liquid crystal cured layer is preferably 0.5 μm to 10 μm, and more preferably 0.5 μm to 5 μm.

The composition containing the polymerizable liquid crystal compound may contain a polymerization initiator, a polymerizable monomer, a surfactant, a solvent, an adhesion improver, a plasticizer, an orienting agent, and the like, in addition to the polymerizable liquid crystal compound. Examples of the method for applying the composition containing the polymerizable liquid crystal compound include known methods such as a die coating method. Examples of the curing method of the composition containing the polymerizable liquid crystal compound include known methods such as irradiation with active energy rays (for example, ultraviolet rays).

(1st bonded layer 25, 2nd bonded layer 27)
The optical laminated film 20 may include a laminating layer for joining the two layers. The optical laminated film 140 with a bonding layer of the second embodiment includes the first bonding layer 25 and the second bonding layer 27 as the bonding layer. Examples of the bonding layer include an adhesive layer and an adhesive layer. For the adhesive layer, a water-based adhesive, an active energy ray-curable adhesive, a thermosetting adhesive, or the like is used. The description of the pressure-sensitive adhesive layer provided on the surface protective film 24 is applied to the pressure-sensitive adhesive layer.

The two opposing surfaces that are 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.

(Phase difference layer)
The optical laminated film 20 may include one layer or two or more retardation layers. The retardation layer may be a liquid crystal cured layer as described above, or may be a resin film. Examples of the retardation layer include a positive A plate such as a λ / 4 plate and a λ / 2 plate, a positive C plate, and the like.

<Adhesive layer 31>
The pressure-sensitive adhesive layer 31 can be composed of a pressure-sensitive adhesive composition containing a resin as a main component, such as (meth) acrylic-based, rubber-based, urethane-based, ester-based, silicone-based, and polyvinyl ether-based. Among them, a pressure-sensitive adhesive composition using a (meth) acrylic resin having excellent transparency, weather resistance, heat resistance and the like as a base polymer is preferable. The pressure-sensitive adhesive composition may be an active energy ray-curable type or a thermosetting type.

Examples of the (meth) acrylic resin (base polymer) used in the pressure-sensitive adhesive composition include butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, and 2- (meth) acrylate. A polymer or copolymer containing one or more (meth) acrylic acid esters such as ethylhexyl as a monomer is preferably used. It is preferable that the base polymer is copolymerized with a polar monomer. Examples of the polar monomer include (meth) acrylic acid, 2-hydroxypropyl (meth) acrylate, hydroxyethyl (meth) acrylate, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, and glycidyl (). Examples thereof include monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group and the like, such as meta) acrylate.

The pressure-sensitive adhesive composition may contain only the above-mentioned base polymer, but usually further contains a cross-linking agent. The cross-linking agent is a divalent or higher metal ion that forms a carboxylic acid metal salt with a carboxyl group; a polyamine compound that forms an amide bond with a carboxyl group; poly. Epoxy compounds and polyols that form an ester bond with a carboxyl group; polyisocyanate compounds that form an amide bond with a carboxyl group are exemplified. Of these, polyisocyanate compounds are preferable.

The active energy ray-curable pressure-sensitive adhesive composition has a property of being cured by being irradiated with active energy rays such as ultraviolet rays and electron beams, and has adhesiveness even before irradiation with active energy rays. It is a pressure-sensitive adhesive composition having the property of being able to adhere to an adherend such as, etc., and being cured by irradiation with active energy rays to adjust the adhesion force. The active energy ray-curable pressure-sensitive adhesive composition is preferably an ultraviolet-curable type. The active energy ray-curable pressure-sensitive adhesive composition further contains an active energy ray-polymerizable compound in addition to the base polymer and the cross-linking agent. Further, if necessary, a photopolymerization initiator, a photosensitizer, or the like may be contained.

The pressure-sensitive adhesive composition includes fine particles for imparting light scattering properties, beads (resin beads, glass beads, etc.), glass fibers, resins other than the base polymer, pressure-sensitive imparting agents, and fillers (metal powders and other inorganic powders). Etc.), antioxidants, UV absorbers, dyes, pigments, colorants, antifoaming agents, corrosion inhibitors, photopolymerization initiators and other additives can be included.

To form the pressure-sensitive adhesive layer 31 on the optical laminated film 20, for example, the pressure-sensitive adhesive composition is dissolved or dispersed in an organic solvent such as toluene or ethyl acetate to prepare a pressure-sensitive adhesive liquid, which is applied to the target surface of the polarizing plate. The pressure-sensitive adhesive layer 31 is formed by direct coating, or the pressure-sensitive adhesive layer 31 is formed in a sheet shape on a separate film that has been subjected to a mold release treatment, and the pressure-sensitive adhesive layer 31 is transferred to the target surface of the optical laminated film 20. It can be done by the method of wearing. The pressure-sensitive adhesive layer 31 can be formed by applying an organic solvent-diluted solution of the pressure-sensitive adhesive composition onto a substrate and drying it. When the active energy ray-curable pressure-sensitive adhesive composition is used, the formed pressure-sensitive adhesive layer 31 can be irradiated with active energy rays to obtain a cured product having a desired degree of curing.

The thickness of the pressure-sensitive adhesive layer 31 is determined according to its adhesive strength and the like, but a range of 1 μm or more and 50 μm or less is appropriate, and preferably 2 μm or more and 40 μm or less.

The pressure-sensitive adhesive layer 31 has a storage elastic modulus of usually 1 MPa or less, preferably 0.15 MPa or less, as measured at a temperature of 20 ° C. and an angular frequency of 100 radians / second. The storage elastic modulus of the pressure-sensitive adhesive is usually 0.001 MPa or more, preferably 0.01 MPa or more.

<Separate film 32>
The optical laminated film with the pressure-sensitive adhesive layer may include a separate film 32 provided on the surface of the pressure-sensitive adhesive layer 31. The separate film 32 can be a film made of a polyethylene resin such as polyethylene, a polypropylene resin such as polypropylene, a polyester resin such as polyethylene terephthalate, or the like. Of these, a polyethylene terephthalate stretched film is preferable. The separate film 32 is peeled off, and the optical laminated film 20 is attached to the adherend via the pressure-sensitive adhesive layer 31.

[Manufacturing method of optical laminated film with adhesive layer]
In the method for producing an optical laminated film with an adhesive layer of the present invention, an optical laminated film including a polarizer layer 21 in which a bicolor dye is adsorbed and oriented, an adhesive layer, and the adhesive layer are detachably bonded to each other. A step of preparing a raw fabric laminated film having the separated separate films in this order, and a cutting step of inserting a corrosive blade into the raw fabric laminated film from the separate film side to cut the raw fabric laminated film to form a side surface. Have. As the 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 a side surface is exemplified.

FIG. 6 is a top view showing an example of a corrosive blade type including a corrosive blade used in the cutting step in the method for manufacturing the optical laminated film 120 with an adhesive layer shown in FIG. The corrosive blade type 121 has a shape in which a corrosive blade formed by etching a metal plate projects three-dimensionally, and the contour 122 shown in FIG. 6 indicates the cutting edge of the corrosive blade and is optically laminated with an adhesive layer. It matches the contour of the film 120.

The corrosive blade mold 121 is pressed against the raw fabric laminated film, and the corrosive blade 122 is inserted into the raw fabric laminated film to be cut, thereby forming a side surface and punching out the optical laminated film 120 with an adhesive layer. A plurality of raw fabric laminated films to be punched may be laminated. One sheet is preferable because the dimensional accuracy of the obtained polarizing plate is good. According to the corrosive blade type 121, six optical laminated films with an adhesive layer can be produced at the same time by one punching. The side surfaces of the optical laminated film 120 with an adhesive layer produced in this manner are all cut surfaces.

The corrosive blade type 121 is manufactured by patterning a resist film by laser irradiation and etching. Therefore, a blade mold with high dimensional accuracy can be obtained. On the other hand, since it is manufactured by etching, its cutting edge is not relatively sharp. Corroded blades are also called pinnacle blades. On the other hand, since the Thomson blade is manufactured by mechanical polishing, its cutting edge is relatively sharp. The reason why the optical laminated film with an adhesive layer having a protective region on the side surface can be obtained by the manufacturing method of the present invention is that a pinnacle blade, which is a corrosive blade at the time of cutting, is used, and a Thomson blade having a relatively sharp cutting edge is used. Compared with the case, a force is more likely to be applied in the layer direction of the pressure-sensitive adhesive layer 31, whereby a protrusion is formed on the pressure-sensitive adhesive layer 31, and the protrusion is formed by a polarizer by allowing the pinnacle blade to enter from the separate film 32 side. It is presumed that it tends to warp toward the layer 21 side.

FIG. 7 shows a cross-sectional view of the corrosive blade 122. The corroded blade 122 includes a cutting edge 122a and a main body 122b. The angle β of the cutting edge 122a is preferably 20 ° to 40 °, more preferably 25 ° to 35 °. The thickness t of the main body 122b is preferably 0.1 mm to 1 mm, more preferably 0.2 mm to 0.6 mm.

FIG. 8 is a cross-sectional view schematically showing a cutting process using the corrosive blade 122. As shown in FIG. 8, the raw fabric laminated film 150 is placed on the backing plate 160. At this time, one raw fabric laminated film 150 is placed so that the optical laminated film 20 of the raw fabric laminated film 150 is located on the backing plate 160 side and the separate film 32 side is located on the side far from the backing plate 160. A plurality of raw fabric laminated films 150 may be laminated and placed, and a plurality of sheets may be punched at the same time. Then, the corrosive blade 122 is made to enter the raw fabric laminated film 150 from the separate film 32 side. When the corroded blade 122 reaches the backing plate 160, the corroded blade 122 is pulled out from the raw fabric laminated film 150, and the punching is completed.

9 to 11 are cross-sectional views schematically showing an example of the cross-sectional shape of the corrosive blade 122, respectively. As shown in FIG. 9, the corrosive blade 122 has a surface to be the target optical laminated film side with an adhesive layer (hereinafter referred to as “A surface”) and a surface on the opposite side (hereinafter, “A surface”) after cutting. The "B surface") may be a so-called double-edged blade that is inclined with respect to the perpendicular line (entrance direction). As shown in FIG. 10, the corrosive blade 122 may be a so-called single-edged blade in which the A surface is parallel to the perpendicular line (approach direction) and only the B surface is inclined with respect to the perpendicular line (approach direction). .. As shown in FIG. 11, the corrosive blade 122 may be a double-edged blade in which the inclination angle with respect to the perpendicular line (approach direction) of the A surface and the inclination angle with respect to the perpendicular line (approach direction) of the B surface are different.

_{The A surface of the corrosive blade 122 preferably has an angle α 1} with respect to the perpendicular direction (approach direction) of 0 ° to 20 °. _{The B surface of the corrosive blade 122 preferably has an angle α 2} with respect to the perpendicular direction (approach direction) of 14 to 20 °. The sum of both angles (α ₁ + α ₂ ) is preferably 20 ° or more in terms of making the cutting blade strong enough, and preferably 40 ° or less in terms of facilitating cutting. .. Both angles (α ₁ , α ₂ ) may be the same (α 1 = α 2). In this case, the corroded blade 122 is a double-edged blade as shown in FIG. Both angles (α ₁ , α ₂ ) may be different. In this case, the corroded blade 122 has _{α 1} > α ₂ regardless of whether it is a single _{blade having an angle α 1} of 0 ° as shown in FIG. 10 or a double blade _{having α 1} <α _{2 as shown in FIG.} It may be a double-edged blade. Normally, when both angles (α ₁ , α ₂ ) are different, α ₁ <α ₂ .

The angle α ₁ is preferably large from the viewpoint that the distance d can be increased. On the other hand, the angle α ₁ is preferably small from the viewpoint of reducing damage (damage, etc.) to the optical laminated film with the adhesive layer due to the entry of the corrosive blade during cutting.

By allowing the corrosive blade 122 to enter from the separate film 32 side at the time of punching, a side surface having a protective region can be formed. Further, by adjusting the shape of the corrosive blade 122, the speed at which the corrosive blade 122 enters the raw fabric laminated film 150, and the like, the distance between the end position of the pressure-sensitive adhesive layer 31 and the end position of the polarizer layer 21. d can be adjusted. _{The larger the angle (α 1} + α ₂ ) of the tip of the corrosive blade 122 and the duller the tip, the larger the distance d can be.

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

In the method for manufacturing the optical laminated film 110 with an adhesive layer shown in FIG. 2, the punching of the outer frame and the punching of the through hole 51 may be performed at the same time, or may be performed at different timings. From the viewpoint of improving the position accuracy of punching, it is preferable to perform the punching at the same time.

In the method for manufacturing an optical laminated film with an adhesive layer, it is preferable that the side surface is formed by punching with a corrosive blade, a method of cutting with a router, and a rotary cutting tool such as a drill. A method of performing drilling may be combined.

[Image display device]
The optical laminated film with an adhesive layer can be used in an image display device. Examples of the image display element used in the image display device include a liquid crystal display element, an organic EL display element, and the like. In constructing the liquid crystal display device, the optical laminated film with an adhesive layer may be used by arranging it on the viewing side, may be used by arranging it on the backlight side, or may be used on the viewing side and the backlight side. It may be used for both.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. Unless otherwise specified, "%" and "part" in the example are mass% and parts by mass. The tests and measurements were carried out as follows.

[Optical Laminated Film A with Adhesive Layer] (Example)
<Manufacturing process of raw fabric laminated film>
The same layer structure as the optical laminated film 130 with an adhesive layer shown in FIG. 4 "Surface protective film 24 / first protective layer 22 / polarizer layer 21 / second protective layer 23 / adhesive layer 31 / A raw fabric laminated film of "separate film 32" was produced as follows.

(Preparation of Polarizer Layer 21)
A long polyvinyl alcohol film is dyed in an aqueous solution containing iodine, and then uniaxially stretched 6 times in the longitudinal direction between rolls having different speed ratios in the aqueous solution containing boric acid to form an absorption axis in the longitudinal direction. An elongated polarizer layer having the same was obtained. This elongated polarizer layer was stretched and then wound up to form a wound body. The luminous efficiency correction polarization degree of the polarizer layer was about 99.995%, the luminous efficiency correction simple substance transmittance was 42.7%, and the thickness was 12 μm.

(Preparation of the first protective layer 22)
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.

(Preparation of the second protective layer 23)
As the second protective layer 23, a long cyclic polyolefin resin film (thickness 13 μm, Zeonoa film manufactured by Nippon Zeon Corporation, trade name: ZF14-013) was prepared.

(Laminating process)
After cutting out the polarizer layer 21, the first protective layer 22, and the second protective layer 23 produced or prepared as described above to a size of 300 mm × 400 mm, respectively, both sides of the polarizer layer 21 are interposed via a polyvinyl alcohol-based adhesive. The first protective layer 22 and the second protective layer 23 were bonded to each other and placed in a drying oven at 80 ° C. for 3 minutes. Next, after the surface of the second protective layer 23 was corona-treated, an acrylic pressure-sensitive adhesive layer 31 (thickness 20 μm) to which a separate film 32 was bonded was laminated on the corona-treated surface side. Finally, a release film with a slight adhesive, which is a surface protective film 24, was laminated on the surface of the first protective layer 22 to obtain a raw fabric laminated film. The corona treatment was performed by a corona discharge device manufactured by Kasuga Electric Works Ltd. Specifically, the corona surface treatment frame "STR-"
1764 ", a high frequency power supply" CT-0212 ", and a high voltage transformer" CT-T02W "were used. In this raw fabric laminated film, a polyvinyl alcohol-based adhesive layer was used between the polarizer layer 21 and the first protective layer 22. 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 (thickness 0.2 μm or less).

<Cutting process>
One of the obtained raw fabric laminated films (300 mm × 400 mm) is punched into the shape of the optical laminated film with an adhesive layer shown in FIG. 3 using a corrosive blade as shown in FIG. A laminated film A was obtained. As the corroding blade, a double-edged blade as shown in FIG. 9 was used, and a corroding blade having _{α 1} = α _{2 = 15 ° was used.} At the time of punching shown in FIG. 8, the raw fabric laminated film 150 was placed so that the surface protective film 24 of the raw fabric laminated film was located on the backing plate 160 side and the separate film 32 was located on the side far from the backing plate 160. The four corners were fixed to the backing plate 160 with curing tape, and the corrosive blade was inserted into the raw film laminated film from the separate film 32 side. The punching was performed so that the absorption axis of the polarizer layer 21 was parallel to the longitudinal direction of the optical laminated film A with the pressure-sensitive adhesive layer. The cutting blade used is one that can reciprocate a stroke (referred to as "1 stroke") of 24 mm (sufficiently exceeding the thickness of the original fabric laminated film) in the punching direction, and one stroke takes 1.5 seconds. By reciprocating, the raw fabric laminated film 150 was cut at the turning point of the reciprocating motion. As the backing plate 160, a stack of one acrylic sheet (thickness 3.5 mm) and one polypropylene sheet (thickness 1.0 mm) was used. The backing plate 160 was used so that the polypropylene sheet side was in contact with the raw fabric laminated film 150.

[Optical Laminated Film B with Adhesive Layer] (Comparative Example)
<Manufacturing process of raw fabric laminated film>
A raw fabric laminated film was prepared by the same method as the manufacturing step in the optical laminated film A with an adhesive layer.

<Cutting process>
One of the obtained raw fabric laminated films (300 mm × 400 mm) is punched into the shape of the optical laminated film with an adhesive layer shown in FIG. 3 using a corrosive blade as shown in FIG. A laminated film B was obtained. At the time of punching shown in FIG. 8, the raw fabric laminated film 150 was placed so that the separate film 32 of the raw fabric laminated film was located on the backing plate 160 side and the surface protective film 24 was located on the side far from the backing plate 160. The four corners were fixed to the backing plate 160 with curing tape, and the corrosive blade was allowed to enter the raw fabric laminated film from the surface protective film 24 side. The punching was performed so that the absorption axis of the polarizer layer 21 was parallel to the longitudinal direction (length 400 mm) of the optical laminated film B with the pressure-sensitive adhesive layer. The cutting blade used is one that can reciprocate a stroke (referred to as "1 stroke") of 24 mm (sufficiently exceeding the thickness of the original fabric laminated film) in the punching direction, and one stroke takes 1.5 seconds. By reciprocating, the raw fabric laminated film 150 was cut at the turning point of the reciprocating motion. As the backing plate 160, a stack of one acrylic sheet (thickness 3.5 mm) and one polypropylene sheet (thickness 1.0 mm) was used. The backing plate 160 was used so that the polypropylene sheet side was in contact with the raw fabric laminated film 150.

[Optical Laminated Film C with Adhesive Layer] (Example)
<Manufacturing process of raw fabric laminated film>
The same layer structure as the optical laminated film 140 with an adhesive layer shown in FIG. 5 "Surface protective film 24 / first protective layer 22 / polarizer layer 21 / second protective layer 23 / first bonded layer" A raw fabric laminated film of "25 / first liquid crystal cured layer 26 / second bonded layer 27 / second liquid crystal cured layer 28 / adhesive layer 31 / separate film 32" was prepared as follows.

(Preparation of Polarizer Layer 21)
A long polyvinyl alcohol film is dyed in an aqueous solution containing iodine, then uniaxially stretched 6 times between rolls having different speed ratios in an aqueous solution containing boric acid, and has an absorption axis in the longitudinal direction. A shape of a polarizer layer was obtained. This elongated polarizer layer was stretched and then wound up to form a wound body. The luminous efficiency correction polarization degree of the polarizer layer was about 99.995%, the luminous efficiency correction simple substance transmittance was 42.7%, and the thickness was 12 μm.

(Preparation of the first protective layer 22)
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.

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

(Preparation of the first liquid crystal cured layer 26)
As the first liquid crystal cured layer 26, a film (thickness 1 μm) composed of a layer on which the nematic liquid crystal compound was cured and an alignment film was prepared. The in-plane retardation value Re (550) of the first liquid crystal cured layer 26 is 140 nm, Re (450) / Re (550) is less than 1.0, and Re (650) / Re (550) is 1. It was over 0.0. The pushing force of the first liquid crystal cured layer 26 measured by the pushing force measuring method described later was 8.8 g / mm.

(Preparation of the second liquid crystal cured layer 28)
As the second liquid crystal cured layer 28, a film (thickness 2 μm) composed of a layer on which the rod-shaped liquid crystal compound was cured and an alignment film was prepared. The second liquid crystal cured layer 28 satisfies the relationship of Nz> Nx = Ny in its plane, its in-plane retardation value Re (550) is 0.6 nm, and its in-plane retardation value Rth (thickness direction). 550) was -69.6 nm. With respect to the second liquid crystal cured layer 28, the pushing force measured by the pushing force measuring method described later was 38.1 g / mm.

(Laminating process)
After cutting out the polarizer layer 21, the first protective layer 22, the second protective layer 23, the first liquid crystal cured layer 26, and the second liquid crystal cured layer 28 produced or prepared as described above to 300 mm × 400 mm, respectively. The first protective layer 22 and the second protective layer 23 were bonded to both sides of the polarizing element layer 21 via a polyvinyl alcohol-based adhesive, and placed in a drying oven at 80 ° C. for 3 minutes. Then, after the surface on the side of the second protective layer 23 was corona-treated, an acrylic pressure-sensitive adhesive (thickness 5 μm) was laminated on the corona-treated surface as the first bonding layer 25. The laminated body thus obtained is called a first laminated body. The corona treatment was performed by a corona discharge device manufactured by Kasuga Electric Works 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.

Next, an ultraviolet curable adhesive is applied to the surface of the first liquid crystal curable layer 26, the second liquid crystal curable layer 28 is bonded, and an ultraviolet irradiation device [Fusion UV Systems Co., Ltd.] is applied from the second liquid crystal curable layer 28 side. The adhesive was cured by irradiating ultraviolet rays with an integrated light amount of 400 mJ / cm ^{2 (UV-B).} The laminated body having a laminated structure of "the first liquid crystal cured layer 26 / the second bonded layer 27 composed of the adhesive layer / the second liquid crystal cured layer 28" obtained in this way is called a second laminated body.

The first laminated body and the second laminated body obtained as described above are bonded together with the first bonded layer 25 of the first laminated body and the first liquid crystal cured layer 26 of the second laminated body. Laminated in. At this time, the slow axis of the first liquid crystal cured layer 26 was laminated so as to form an angle of −45 ° with respect to the absorption axis of the polarizer layer 31.

Then, an acrylic pressure-sensitive adhesive layer 31 (thickness 20 μm) to which the separate film 32 was bonded was laminated on the surface of the second liquid crystal cured layer 28. Finally, a release film with a slight adhesive, which is a surface protective film 24, was laminated on the surface of the first protective layer 22 to obtain a raw fabric laminated film.

<Cutting process>
One of the obtained raw fabric laminated films (300 mm × 400 mm) is punched into the shape of the optical laminated film with an adhesive layer shown in FIG. 3 using a corrosive blade as shown in FIG. Laminated film C was obtained. At the time of punching shown in FIG. 8, the raw fabric laminated film 150 was placed so that the surface protective film 24 of the raw fabric laminated film was located on the backing plate 160 side and the separate film 32 was located on the side far from the backing plate 160. The four corners were fixed to the backing plate 160 with curing tape, and the corrosive blade was inserted into the raw film laminated film from the separate film 32 side. The punching was performed so that the absorption axis (stretching direction) of the polarizer layer 21 was parallel to the longitudinal direction (400 mm) of the optical laminated film C with the pressure-sensitive adhesive layer. The cutting blade is a cutting blade capable of reciprocating a stroke (hereinafter referred to as "1 stroke") of 24 mm (sufficiently exceeding the thickness of the original fabric laminated film) in the punching direction, and one stroke is 1.5. The film was reciprocated in seconds, and the raw fabric laminated film 150 was cut at the turning point of the reciprocating motion. As the backing plate 160, a stack of one acrylic sheet (thickness 3.5 mm) and one polypropylene sheet (thickness 1.0 mm) was used. The backing plate 160 was used so that the polypropylene sheet side was in contact with the raw fabric laminated film 150.

[Optical Laminated Film D with Adhesive Layer] (Comparative Example)
<Manufacturing process of raw fabric laminated film>
A raw fabric laminated film was produced by the same method as in the process of producing the optical laminated film D with an adhesive layer.

<Punching process>
One of the obtained raw fabric laminated films (300 mm × 400 mm) was punched into the shape of the optical laminated film with an adhesive layer shown in FIG. 3 using a corrosive blade as shown in FIG. 8 to obtain a sample 4. .. At the time of punching shown in FIG. 8, the raw fabric laminated film 150 was placed so that the separate film 32 of the raw fabric laminated film was located on the backing plate 160 side and the surface protective film 24 was located on the side far from the backing plate 160. The four corners were fixed to the backing plate 160 with curing tape, and the corrosive blade was allowed to enter the raw fabric laminated film from the surface protective film 24 side. The punching was performed so that the absorption axis of the polarizer layer 21 was parallel to the longitudinal direction (400 mm) of the optical laminated film D with the pressure-sensitive adhesive layer. The cutting blade is a cutting blade capable of reciprocating a stroke (hereinafter referred to as "1 stroke") of 24 mm (sufficiently exceeding the thickness of the original fabric laminated film) in the punching direction, and one stroke is 1.5. The film was reciprocated in seconds, and the raw fabric laminated film 150 was cut at the turning point of the reciprocating motion. As the backing plate 160, a stack of one acrylic sheet (thickness 3.5 mm) and one polypropylene sheet (thickness 1.0 mm) was used. The backing plate 160 was used so that the polypropylene sheet side was in contact with the raw fabric laminated film 150.

[Side observation]
With respect to the optical laminated films A to D with the adhesive layer, the cross-sectional shape of the starting position of the curved surface region on the side surface was observed with an optical microscope. 12 (a) and 12 (b) are drawings schematically showing an observation image of the optical laminated films A and B with an adhesive layer by an optical microscope. 13 (a) and 13 (b) are drawings schematically showing an observation image of the optical laminated films C and D with an adhesive layer with an optical microscope.

As can be seen from FIGS. 12 and 13, the side surfaces of the optical laminated films A and C with the pressure-sensitive adhesive layer have the pressure-sensitive adhesive layer 31 protruding outward from the most extreme position of the polarizing layer 21 and warped toward the polarizing layer 21. Was there. That is, a protected area was formed. On the other hand, on the side surfaces of the optical laminated films B and D with the pressure-sensitive adhesive layer, although the pressure-sensitive adhesive layer 31 protrudes outward from the most extreme position of the polarizer layer 21, it is warped on the opposite side to the polarizer layer 21. .. That is, it did not have a protected area. In each of the optical laminated film A with the pressure-sensitive adhesive layer and the optical laminated film D with the pressure-sensitive adhesive layer, the distance d between the end position of the pressure-sensitive adhesive layer 31 and the end position of the polarizer layer 21 was 15 μm. Further, each of the optical laminated film A with an adhesive layer to the optical laminated film D with an adhesive layer is a polyvinyl alcohol-based adhesive layer interposed between the polarizer layer 21 and the first protective layer 22, and the polarizer layer 21. The polyvinyl alcohol-based adhesive layer interposed between the second protective layer 23 and the second protective layer 23 was not observed. In each of the optical laminated film C with an adhesive layer and the optical laminated film D with an adhesive layer, the first bonded layer 25, the second liquid crystal cured layer 26, the second bonded layer 27, and the second liquid crystal cured layer 28 are respectively. Could not be identified and observed, and was observed as an integral layer (shown as layer 29 in FIGS. 13 (a) and 13 (b)).

[Thermal impact test]
The optical laminated films A to D with an adhesive layer were bonded to the surface of non-alkali glass (Eagle XG manufactured by Corning, 120 × 200 × 0.7 mm) whose surface was cleaned with ethanol, and then at 50 ° C. An autoclave treatment was performed at 0.5 MPa (gauge pressure) for 20 minutes. This was used as an evaluation sample.

An evaluation sample was placed in a thermal shock test tank, and thermal stimulation at −40 ° C. and 85 ° C. was applied in a cycle of 30 minutes each. A total of 100 cycles were tested for each sample, with the thermal stimulation from low temperature to high temperature as one cycle.

[Crack evaluation]
The occurrence of cracks in the evaluation sample after the thermal shock test was observed with an optical microscope. In particular, the curved surface region was observed in detail. An optical microscope image of an example of the cracks generated is shown in FIG. This figure (optical microscope image) is an optical microscope image from the upper surface of a specific region common to the optical laminated films A and B with an adhesive layer. Observe the cracks generated from the curved surface region defined so that each evaluation sample has the same range, classify the cracks as follows based on the length of the cracks, and determine the number of cracks included in each classification. Measured. The results are shown in Table 1.
Short cracks: Cracks with a length of less than 100 μm Medium cracks: Cracks with a length of 100 μm or more and less than 200 μm Length cracks: Cracks with a length of 200 μm or more

As shown in Table 1, the optical laminated films A and C with the pressure-sensitive adhesive layer according to the present invention did not crack even after 100 cycles in the thermal shock test.

[Measurement of pushing force]
A triacetyl cellulose film having a thickness of 60 μm as a sample A, a triacetyl cellulose film having a thickness of 20 μm as a sample B, a cycloolefin polymer film having a thickness of 23 μm as a sample C, and an optical laminated film C with an adhesive layer as samples D and E.
The first liquid crystal cured layer 26 and the second liquid crystal cured layer 28 prepared at the time of producing D were prepared, and the pushing force of each sample was measured by the following method.

As shown in (a) of FIG. 15 and a cross-sectional view of (b), each sample 170 is cut into a rectangular shape of 30 mm × 30 mm, and a mount having a rectangular opening 171a of 10 mm × 10 mm in the center. It was attached onto 171 (a rectangle having a thickness of 85 μm and a thickness of 30 mm × 30 mm) so as to close the opening 171a via an adhesive layer 172 having a thickness of 25 μm. Then, from above the sample 170 side of the closed opening 171a, an iron rod 173 with a tip diameter of 1.0 mm was pushed in at a speed of 0.33 mm / s, and a handy compression tester (KEN-G5, Kato Tech Co., Ltd.) The pushing force with respect to the amount of deformation in the thickness direction was measured using (manufactured by the company). FIG. 16 shows the measurement result. Table 2 shows the slope of the pushing force calculated based on the measurement result of FIG.

20 Optical laminated film, 21 Polarizer layer, 22 First protective layer, 23 Second protective layer, 24 Surface protective film, 25 First bonded layer, 26 First liquid crystal cured layer, 27 Second bonded layer, 28th 2 Liquid crystal curing layer, 31 Adhesive layer, 32 Separate film, 51 Through hole, 52 Square part, 53 Concave part, 100, 110, 120, 130, 140 Optical laminated film with adhesive layer, 100a, 130a, 140a Protective area , 121 Corrosion blade type, 122 Corrosion blade, 122a cutting edge, 122b main body, 150 original fabric laminated film, 160 backing plate.

Claims (10)

An optical laminated film with an adhesive layer having an optically laminated film containing a polarizing element layer in which a dichroic dye is adsorbed and oriented, and an adhesive layer in this order.
At least a part of the side surface of the optical laminated film with the pressure-sensitive adhesive layer is a protective region in which the pressure-sensitive adhesive layer protrudes outward from the most extreme position of the polarizer layer and warps toward the polarizer layer. , Optical laminated film with adhesive layer. At least a part of the side surface of the optical laminated film with the pressure-sensitive adhesive layer is a curved surface region in which the contour of the surface of the optical laminated film on the side opposite to the pressure-sensitive adhesive layer side is curved.
The optical laminated film with an adhesive layer according to claim 1, wherein at least a part of the curved surface region is the protective region. 2. The protected region in the curved surface region includes a portion where 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 more than 0 ° and 90 ° or less. The optical laminated film with an adhesive layer according to the above. The optical laminated film with an adhesive layer according to any one of claims 1 to 3, wherein the protective region is a cut surface. The protection region according to any one of claims 1 to 4, wherein the protective region includes a region where the distance d between the end position of the pressure-sensitive adhesive layer and the end position of the polarizer layer is 10 μm or more. Optical laminated film with adhesive layer. The optical lamination with an adhesive layer according to any one of claims 1 to 5, further comprising a separate film detachably bonded to the surface of the pressure-sensitive adhesive layer on the side opposite to the optical lamination film side. the film. The optical laminated film with an adhesive layer according to any one of claims 1 to 6, wherein the optical laminated film contains a liquid crystal cured layer made of a polymerized cured product of a polymerizable liquid crystal compound. The optical laminated film includes a protective layer on the side opposite to the pressure-sensitive adhesive layer when viewed from the polarizer layer.
The optical laminated film with an adhesive layer according to any one of claims 1 to 7, wherein the protective layer includes a hard coat layer forming a surface opposite to the polarizer layer side. A raw fabric laminated film having an optical laminated film including a polarizing element layer in which a dichroic dye is adsorbed and oriented, an adhesive layer, and a separate film detachably bonded to the adhesive layer is prepared in this order. Process and
A method for producing an optical laminated film with an adhesive layer, which comprises a cutting step of inserting a corrosive blade into the raw fabric laminated film from the separate film side to cut the raw fabric laminated film to form a side surface. The adhesive according to claim 9, wherein at least a part of the side surface is a protective region in which the pressure-sensitive adhesive layer protrudes outward from the most extreme position of the polarizer layer and warps toward the polarizer layer. A method for manufacturing an optical laminated film with an agent layer.

Images