WO2020080055A1 - Optical laminate and display device - Google Patents

Abstract

The objective of the invention is to provide an optical laminate that is bendable and comprises a front plate and a back plate layered with an adhesive layer therebetween, and a colored layer formed in a portion of the surface of the front plate or the back plate on the adhesive layer side, wherein entry of air bubbles of 10 μm or greater between the layers has been suppressed. This optical laminate comprises a front plate, an adhesive layer including a first adhesive layer and a second adhesive layer, and a back plate, which have been layered in this order, and a colored layer formed in a portion of either one of the front plate or the back plate on the adhesive layer side thereof, wherein the adhesive layer is disposed in such a manner that the second adhesive layer is on the colored layer side, and layered in such a manner as to cover at least the end portion on the inner side of the colored layer in a planar view of the optical laminate, the first adhesive layer and the second adhesive layer containing a (meth)acrylic resin, and satisfying (1) 0.01 MPa ≤ storage modulus of the first adhesive layer and the second adhesive layer ≤ 0.1 MPa and (2) 0.5 ≤ loss tangent of the second adhesive layer ≤ 0.8.

Description

Optical laminated body and display device

The present invention relates to an optical laminate and a display device.

Patent Document 1 describes a foldable display device in which a display panel, a polarizing member provided on the display panel, and a window provided on the polarizing member are adhered by adhesive members.

Patent Document 2 describes a double-sided pressure-sensitive adhesive sheet having a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer for bonding a display device and an optical member together. Patent Document 3 describes a pressure-sensitive adhesive sheet having a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer arranged between a protective panel and a polarizing film.

JP, 2017-126061, A JP, 2016-194085, A Japanese Patent No. 4806730

A bendable optical laminate in which a front plate and a back plate are laminated via an adhesive layer, and a colored layer is partially formed on the adhesive layer side of the front plate or the back plate has a size of 10 μm or more between the layers. Bubbles having a certain size may be mixed.

The present invention is a bendable optical laminate in which a front plate and a back plate are laminated via a pressure-sensitive adhesive layer, and a colored layer is partially formed on the pressure-sensitive adhesive layer side of the front plate or the back plate, It is an object of the present invention to provide an optical layered body in which the inclusion of bubbles having a size of 10 μm or more between layers is suppressed.

The present invention provides the following laminated body and display device.
[1] A front plate, a pressure-sensitive adhesive layer, and a back plate, which are laminated in this order, and are partially formed on either the pressure-sensitive adhesive layer side of the front plate or the pressure-sensitive adhesive layer side of the back plate. A laminate having layers,
The pressure-sensitive adhesive layer includes a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer, and the second pressure-sensitive adhesive layer is laminated so as to be on the colored layer side,
The pressure-sensitive adhesive layer is arranged so as to cover at least an end portion inside the colored layer in a plan view of the optical laminate,
The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer include a (meth) acrylic resin,
An optical laminate satisfying the following (1) and (2).
(1) 0.01 MPa ≤ storage elastic modulus of first adhesive layer and second adhesive layer ≤ 0.1 MPa (2) 0.5 ≤ loss tangent of second adhesive layer ≤ 0.8
[2] The optical laminate according to [1], wherein the loss tangent of the first pressure-sensitive adhesive layer is different from the loss tangent of the second pressure-sensitive adhesive layer.
[3] The optical laminate according to [1] or [2], wherein the thickness of the second pressure-sensitive adhesive layer is larger than the thickness of the colored layer.
[4] The optical laminate according to any one of [1] to [3], wherein the total thickness of the first adhesive layer and the second adhesive layer is 25 μm or more and 150 μm or less.
[5] A display device including the optical layered body according to any one of [1] to [4].
[6] The optical layered body according to any one of [1] to [4], wherein the compression elastic modulus of the first pressure-sensitive adhesive layer is 3 MPa or more and 12 MPa or less.
[7] The optical layered body according to any one of [1] to [4], wherein the compression elastic modulus of the second pressure-sensitive adhesive layer is 3 MPa or more and 5 MPa or less.

According to the present invention, there is provided a bendable optical laminate in which a front plate and a back plate are laminated via an adhesive layer, and a colored layer is partially formed on the adhesive layer side of the front plate or the back plate. As a result, an optical layered body in which the inclusion of air bubbles having a size of 10 μm or more is suppressed between layers is provided.

It is a schematic sectional drawing which shows the optical laminated body which concerns on 1 aspect of this invention. It is a schematic sectional drawing of the laminated body which shows the manufacturing method of the laminated body of this invention typically. It is a schematic sectional drawing of the laminated body which shows the manufacturing method of the laminated body of this invention typically.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. In all the drawings below, the scales are appropriately adjusted and shown for easy understanding of the respective components, and the scales of the respective components shown in the drawings do not necessarily match the actual scales of the components.

<Optical laminate>
FIG. 1 is a schematic sectional view of an optical laminate according to an embodiment of the present invention. The optical layered body 100 (hereinafter, also abbreviated as “layered body”) 100 shown in FIG. 1 has a front plate 10, a pressure-sensitive adhesive layer 20, and a back plate 30 laminated in this order. The laminated body 100 further includes a colored layer 40 that is partially formed on the adhesive layer 20 side of the back plate 30. The pressure-sensitive adhesive layer 20 includes a first pressure-sensitive adhesive layer 21 and a second pressure-sensitive adhesive layer 22, and the second pressure-sensitive adhesive layer 22 is laminated so as to be on the colored layer side.
The colored layer 40 may be partially formed on the adhesive layer 20 side of the front plate 10 instead of being partially formed on the adhesive layer 20 side of the back plate 30.

The laminated body 100 can be bent. The term “bendable” means that it can be bent with a radius of curvature of 3 mm. The laminate 100 preferably has no cracks even when the inner surface of the laminate 100 has a curvature radius of 3 mm and the number of bends is 10,000.

The thickness of the laminated body 100 is not particularly limited because it varies depending on the function required for the laminated body and the application of the laminated body, but is, for example, 50 μm or more and 1,000 μm or less, preferably 100 μm or more and 500 μm or less.

The planar view shape of the laminated body 100 may be, for example, a rectangular shape, preferably a rectangular shape having long sides and short sides, and more preferably a rectangle. When the shape of the laminate 100 in the surface direction is rectangular, the length of the long side may be, for example, 10 mm or more and 1400 mm or less, and preferably 50 mm or more and 600 mm or less. The length of the short side is, for example, 5 mm or more and 800 mm or less, preferably 30 mm or more and 500 mm or less, and more preferably 50 mm or more and 300 mm or less.

When the planar view shape of the laminated body 100 is a square shape, the lengths of the sides of the front plate 10 and the back plate 30 may be the same, and the positions of the end portions of the front plate 10 and the back plate 30 are the same. Preferably there is. When the laminate 100 has a rectangular shape in a plan view, the positions of the ends of the pressure-sensitive adhesive layer 20 may be the same as the positions of the ends of the front plate 10 or the back plate 30, or may be inside. .

The laminated body 100 can be used, for example, in a display device or the like. The display device is not particularly limited, and examples thereof include an organic electroluminescence (organic EL) display device, an inorganic electroluminescence (inorganic EL) display device, a liquid crystal display device, and an electroluminescent display device. The display device may have a touch panel function. The laminated body 100 is suitable for a display device having flexibility.

Conventionally, a flexible optical laminate in which a colored layer is partially formed on the surface of the front plate or the back plate on the side of the pressure-sensitive adhesive has a flexibility between the colored layer and the pressure-sensitive adhesive layer or between the first pressure-sensitive adhesive layer and the first pressure-sensitive adhesive layer. There is a problem that bubbles having a length of 10 μm or more (hereinafter, also referred to as specific bubbles) are formed between the second pressure-sensitive adhesive layer and between the front plate or the back plate and the pressure-sensitive adhesive layer. The present inventor has conducted extensive research on suppression of bubbles, and as a result, a step is formed in the thickness direction of the laminate between the region where the colored layer is present and the region where the colored layer is not present, and the adhesive formed on the step. The agent layer cannot follow the step, and bubbles are likely to occur between the adhesive layer and the front plate or the back plate on which the colored layer is formed, particularly in the step between the front plate or the back plate and the colored layer. stopped. Therefore, when further research was conducted focusing on the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer was made to have a two-layer structure, and the loss tangent (hereinafter also referred to as tan δ) of the layer in contact with the colored layer was set within a specific range. It has been found that each adhesive layer contains an acrylic resin and exhibits a specific storage elastic modulus, whereby bubbles can be suppressed without impairing the flexibility.

The specific bubbles can be observed by observing the transmission image of the laminate with an optical microscope. The specific bubbles are often generated in parallel with the end portion inside the colored layer in the plane direction of the laminate. Therefore, the shape of the specific bubble is often linear. When the specific bubbles are linear, the length may be 10 μm or more and the width may be, for example, 0.01 μm or more and 5 μm or less. When specific bubbles are generated, they are often generated both between the colored layer and the pressure-sensitive adhesive layer and between the front plate or the back plate and the pressure-sensitive adhesive layer. When the reference is used, it often occurs at a position with the reference as the axis of symmetry.

(Front plate)
The front plate 10 is not limited in material and thickness as long as it is a plate that can transmit light, and may be composed of only one layer or may be composed of two or more layers. Examples thereof include a resin plate-shaped body (for example, a resin plate, a resin sheet, a resin film, etc.) and a glass plate-shaped body (for example, a glass plate, a glass film, etc.). The front plate can be a layer forming the outermost surface of the display device.

The thickness of the front plate 10 may be, for example, 30 μm or more and 2,000 μm or less, preferably 50 μm or more and 1,000 μm or less, and more preferably 50 μm or more and 500 μm or less. In the present invention, the thickness of each layer can be measured according to the thickness measuring method described in Examples below.

When the front plate 10 is a resin plate, the resin plate is not limited as long as it can transmit light. Examples of the resin include triacetyl cellulose, acetyl cellulose butyrate, ethylene-vinyl acetate copolymer, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, polyester, polystyrene, polyamide, polyetherimide, poly (meth) acryl, polyimide , Polyethersulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyether sulfone, polymethyl methacrylate, polyethylene terephthalate, Polymers such as polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyamide-imide Formed film. These polymers can be used alone or in combination of two or more. From the viewpoint of improving strength and transparency, a resin film formed of a polymer such as polyimide, polyamide, or polyamide-imide is preferable. The thickness of the resin plate may be, for example, 30 μm or more and 2,000 μm or less, preferably 50 μm or more and 1,000 μm or less, more preferably 50 μm or more and 500 μm or less, and may be 100 μm or less. .

The front plate 10 may be a film in which a hard coat layer is provided on at least one surface of the base film to further improve hardness. As the substrate film, a film made of the above resin can be used. The hard coat layer may be formed on one surface of the base film, or may be formed on both surfaces. By providing the hard coat layer, it is possible to obtain a resin film having improved hardness and scratch resistance. The hard coat layer is, for example, a cured layer of an ultraviolet curable resin. Examples of the ultraviolet curable resin include acrylic resin, silicone resin, polyester resin, urethane resin, amide resin, and epoxy resin. The hard coat layer may contain an additive in order to improve the strength. The additive is not limited and includes inorganic fine particles, organic fine particles, or a mixture thereof.

When the front plate 10 is a glass plate, tempered glass for display is preferably used as the glass plate. The thickness of the glass plate may be, for example, 10 μm or more and 1,000 μm or less.
By using the glass plate, the front plate 10 having excellent mechanical strength and surface hardness can be formed.

When the laminated body 100 is used in a display device, the front plate 10 may have a function as a window film in the display device. The front plate 10 may have a function as a touch sensor, a blue light cut function, a viewing angle adjustment function, and the like.

(Adhesive layer)
The pressure-sensitive adhesive layer 20 may be a layer that is interposed between the front plate 10 and the back plate 30 to bond them.

The adhesive layer 20 includes a first adhesive layer 21 and a second adhesive layer 22. The first adhesive layer 21 and the second adhesive layer 22 may have different adhesive compositions. The adhesive layer 20 may be, for example, a laminate in which a first adhesive layer 21 and a second adhesive layer 22 are laminated, and the first adhesive layer 21 and the second adhesive layer 22 are laminated in contact with each other. May be done. The pressure-sensitive adhesive layer 20 is laminated on the front plate 10 or the rear plate 30 so that the second pressure-sensitive adhesive layer 22 is on the colored layer 40 side. The pressure-sensitive adhesive layer 20 may be laminated such that the second pressure-sensitive adhesive layer 22 is closer to the colored layer 40 than the first pressure-sensitive adhesive layer 21, or may be laminated so as to be in contact with the colored layer 40. Moreover, the pressure-sensitive adhesive layer 20 is laminated so as to cover at least an end portion inside the colored layer 40 in a plan view of the optical laminate 100. The step due to the colored layer 40 is absorbed by the pressure-sensitive adhesive layer 20 including the first pressure-sensitive adhesive 21 having a specific storage elastic modulus and the second pressure-sensitive adhesive layer 22 having a specific elastic modulus and loss tangent, and thus the adhesiveness is increased. The surface of the agent layer tends to be smooth, and mixing of specific bubbles tends to be suppressed easily. From the viewpoint of step difference absorption, the pressure-sensitive adhesive layer 20 preferably covers the entire colored layer 40 and the entire portion of the front plate 10 or the rear plate 30 where the colored portion is not formed in plan view of the optical laminate 100. It is stacked. In the present specification, the plan view means viewing from the thickness direction of the layer.

(First adhesive layer)
The first pressure-sensitive adhesive layer 21 may be attached to one of the front plate 10 or the rear plate 30 on which the colored layer 40 is not formed. The first pressure-sensitive adhesive layer 21 contains a (meth) acrylic resin.

The storage elastic modulus of the first adhesive layer 21 is 0.01 MPa or more and 0.1 MPa or less, and preferably 0.02 MPa or more and 0.08 MPa or less. When the storage elastic modulus of the first pressure-sensitive adhesive layer 21 is 0.01 MPa or more and 0.1 MPa or less, the laminate 100 tends to have excellent flexibility. In the present invention, the storage elastic modulus can be measured according to the measuring method described in the section of Examples below. As the storage elastic modulus, a value at room temperature (temperature 23 ° C.) can be adopted.

The storage elastic modulus of the first pressure-sensitive adhesive layer 21 is determined by selecting the material forming the first pressure-sensitive adhesive layer 21, the thickness of the first pressure-sensitive adhesive layer 21, the manufacturing conditions of the first pressure-sensitive adhesive layer 21, such as the first pressure-sensitive adhesive. When the layer 21 is composed of an active energy ray-curable pressure-sensitive adhesive composition, it can be adjusted by UV irradiation amount and the like, and a combination thereof. For example, the storage elastic modulus of the first pressure-sensitive adhesive layer 21 tends to increase when a monomer having a relatively large molecular weight is used for producing the (meth) acrylic resin contained in the pressure-sensitive adhesive composition 1 described later. Further, for example, when the UV irradiation amount is increased, the storage elastic modulus of the first pressure-sensitive adhesive layer 21 tends to increase.

The loss tangent of the first pressure-sensitive adhesive layer 21 is, for example, 0.7 or less, preferably less than 0.5, and more preferably 0.3 or less.

The first pressure-sensitive adhesive layer 21 can be formed from a pressure-sensitive adhesive composition containing a (meth) acrylic resin as a main component (hereinafter, also referred to as pressure-sensitive adhesive composition 1). In the present specification, the term “(meth) acrylic resin” means at least one selected from the group consisting of acrylic resins and methacrylic resins. The same applies to other terms with "(meta)". The pressure-sensitive adhesive composition 1 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 1 include butyl (meth) acrylate, ethyl (meth) acrylate, hexyl (meth) acrylate, and octyl (meth) acrylate. One of (meth) acrylic acid ester such as lauryl (meth) acrylate, isooctyl (meth) acrylate, isodecyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) acrylate or Polymers or copolymers having two or more monomers as monomers are preferably used. It is preferable to copolymerize a polar monomer with the base polymer. Examples of polar monomers include (meth) acrylic acid, (meth) acrylic acid 4-hydroxybutyl acrylate, (meth) acrylic acid 2-hydroxypropyl, (meth) acrylic acid hydroxyethyl, (meth) acrylamide, N, N 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 dimethylaminoethyl (meth) acrylate and glycidyl (meth) acrylate.

The pressure-sensitive adhesive composition 1 may contain only the above base polymer, but usually further contains a crosslinking agent. As the cross-linking agent, a metal ion having a valence of 2 or more and forming a carboxylic acid metal salt with a carboxyl group; a polyamine compound forming an amide bond with a carboxyl group; Examples thereof include epoxy compounds and polyols that form an ester bond with a carboxyl group; and polyisocyanate compounds that form an amide bond with a carboxyl group. 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 an active energy ray such as an ultraviolet ray or an electron beam, and has adhesiveness even before irradiation with the active energy ray. It is a pressure-sensitive adhesive composition having a property that it can be brought into close contact with an adherend such as the above, and can be cured by irradiation with an active energy ray to adjust the adhesion. The active energy ray-curable pressure-sensitive adhesive composition is preferably UV-curable. 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 crosslinking agent. Further, if necessary, a photopolymerization initiator, a photosensitizer or the like may be contained.

The pressure-sensitive adhesive composition 1 includes fine particles for imparting light-scattering property, beads (resin beads, glass beads, etc.), glass fibers, resins other than base polymers, tackifiers, fillers (metal powder and other inorganic materials). Powder, etc.), antioxidants, ultraviolet absorbers, dyes, pigments, colorants, defoamers, corrosion inhibitors, photopolymerization initiators, and other additives.

It can be formed by applying a diluted solution of the pressure-sensitive adhesive composition 1 in an organic solvent onto a substrate and drying. When the active energy ray-curable pressure-sensitive adhesive composition is used, the formed pressure-sensitive adhesive layer can be irradiated with an active energy ray to give a cured product having a desired degree of curing.

The thickness of the first pressure-sensitive adhesive layer 21 is preferably thin from the viewpoint of conformability and flexibility, and is preferably, for example, 3 μm or more and 100 μm or less, more preferably 5 μm or more and 50 μm or less, and 20 μm or more. Good.

(Second adhesive layer)
The second pressure-sensitive adhesive layer 22 can be attached to either the front plate 10 or the rear plate 30 on which the colored layer 40 is formed. The second pressure-sensitive adhesive layer 22 contains a (meth) acrylic resin.

The loss tangent of the second pressure-sensitive adhesive layer 22 is 0.5 or more and 0.8 or less, preferably 0.55 or more and 0.75 or less. When the loss tangent of the second pressure-sensitive adhesive layer 22 is 0.5 or more and 0.8 or less, excellent followability tends to be easily obtained. In the present invention, the loss tangent can be measured according to the measuring method described in the section of Examples below. As the loss tangent, a value at room temperature (temperature 23 ° C) can be adopted.

The loss tangent of the second pressure-sensitive adhesive layer 22 should be adjusted by selecting the material for forming the second pressure-sensitive adhesive layer 22, the thickness of the second pressure-sensitive adhesive layer 22, the combination of the manufacturing conditions of the second pressure-sensitive adhesive layer 22, and the like. You can
For example, the loss tangent of the second pressure-sensitive adhesive layer 22 tends to increase when a monomer having a relatively large molecular weight is used for producing the (meth) acrylic resin contained in the pressure-sensitive adhesive composition 2 described later.

The storage elastic modulus of the second pressure-sensitive adhesive layer 22 is 0.01 MPa or more and 0.1 MPa or less, and preferably 0.02 MPa or more and 0.08 MPa or less. When the storage elastic modulus of the second pressure-sensitive adhesive layer 22 is 0.01 MPa or more and 0.1 MPa or less, the laminate 100 tends to have excellent flexibility.

The method of adjusting the storage elastic modulus of the second pressure-sensitive adhesive layer 22 is the same as the method exemplified in the above description of the first pressure-sensitive adhesive layer 21. The second pressure-sensitive adhesive layer 22 can be formed from a pressure-sensitive adhesive composition (hereinafter, also referred to as pressure-sensitive adhesive composition 2). The pressure-sensitive adhesive composition 2 can be formed from the pressure-sensitive adhesive composition containing the above-mentioned (meth) acrylic resin as a main component. From the viewpoint of loss tangent, the pressure-sensitive adhesive composition 2 is preferably an active energy ray-curable type.

The (meth) acrylic resin (base polymer), the cross-linking agent, the photopolymerization initiator, the additives and the like contained in the pressure-sensitive adhesive composition 2 are the same as those exemplified in the description of the pressure-sensitive adhesive composition 1. The method for forming the second adhesive layer may be the same as the method for forming the first adhesive layer.

The thickness of the second pressure-sensitive adhesive layer 22 is preferably larger than the thickness of the colored layer 40 from the viewpoint of absorbing the step difference of the colored layer 40, for example, preferably 3 μm or more and 100 μm or less, and 5 μm or more and 50 μm or less. More preferably, it may be 20 μm or more.

(Total thickness of adhesive layer)
The total thickness of the first adhesive layer 21 and the second adhesive layer 22 may be, for example, 25 μm or more and 150 μm or less, preferably 30 μm or more and 125 μm or less, and more preferably 40 μm or more and 100 μm or less. When the total thickness is within the above range, good step followability and bending resistance tend to be easily obtained.

(Difference in loss tangent)
The loss tangent of the first pressure-sensitive adhesive layer 21 may be different from the loss tangent of the second pressure-sensitive adhesive layer 22, for example, and is preferably smaller than the loss tangent of the second pressure-sensitive adhesive layer 22. When the loss tangents of the first adhesive layer 21 and the second adhesive layer 22 are different, the absolute value of the difference may be, for example, 0.05 or more, and preferably 0.25 or more and 0.5 or less. .

(Compression modulus)
The compression elastic modulus of the first pressure-sensitive adhesive layer may be, for example, 3 MPa or more and 12 MPa or less. When the compressive elastic modulus of the first pressure-sensitive adhesive layer is 3 MPa or more, the first pressure-sensitive adhesive layer tends to be hardly peeled off from the adherend during bending. On the other hand, when the compressive elastic modulus of the first pressure-sensitive adhesive layer is 12 MPa or less, cracks tend not to easily occur on the front plate and the back plate during bending. The compression modulus of the first pressure-sensitive adhesive layer is preferably 3 MPa or more and 10 MPa or less from the viewpoint of suppressing the peeling and cracking.

The compressive elastic modulus of the second pressure-sensitive adhesive layer may be, for example, 3 MPa or more and 5 MPa or less. When the compression elastic modulus of the second pressure-sensitive adhesive layer is within the above range, the step-following property of the second pressure-sensitive adhesive layer tends to be excellent.

(Back plate)
As the back plate 30, it is possible to use a plate-like body capable of transmitting light, components used in a normal display device, and the like.

The thickness of the back plate 30 may be, for example, 5 μm or more and 2,000 μm or less, preferably 10 μm or more and 1,000 μm or less, and more preferably 15 μm or more and 500 μm or less.

The plate-shaped body used for the back plate 30 may be composed of only one layer, or may be composed of two or more layers, and the plate-shaped body described for the back plate 10 may be used. it can.

The components used in the normal display device used for the back plate 30 include, for example, a polarizing plate, a touch sensor panel, a retardation film, and the like.

(Polarizer)
Examples of the polarizing plate include a stretched film having a dye having absorption anisotropy adsorbed thereon, or a film containing a film obtained by coating and curing a dye having absorption anisotropy as a polarizer. Examples of the dye having absorption anisotropy include dichroic dyes. As the dichroic pigment, specifically, iodine or a dichroic organic dye is used. The dichroic organic dye includes C.I. I. A dichroic direct dye composed of a disazo compound such as DIRECT RED 39 and a dichroic direct dye composed of a compound such as trisazo and tetrakisazo are included. The film coated with a dye having absorption anisotropy, which is used as a polarizer, is a stretched film on which a dye having absorption anisotropy is adsorbed, or a composition or a dichroic dye containing liquid crystallinity. Examples thereof include a film having a layer obtained by applying a composition containing a colorant and a polymerizable liquid crystal and curing the composition. A film coated with a dye having absorption anisotropy and cured is preferable because it has no limitation in the bending direction as compared with a stretched film to which a dye having absorption anisotropy is adsorbed.

(1) Polarizing Plate Having Stretched Film as Polarizer A polarizing plate having a stretched film having a dye having absorption anisotropy adsorbed thereon as a polarizer will be described. The stretched film, which is a polarizer and has a dye having absorption anisotropy adsorbed, is usually a step of uniaxially stretching a polyvinyl alcohol-based resin film, by staining the polyvinyl alcohol-based resin film with a dichroic dye, It is manufactured through a step of adsorbing a dichroic dye, a step of treating the polyvinyl alcohol-based resin film on which the dichroic pigment is adsorbed with a boric acid aqueous solution, and a step of washing with water after the treatment with the boric acid aqueous solution. Such a polarizer may be used as it is as a polarizing plate, or one having a transparent protective film laminated on one side or both sides may be used as a polarizing plate. The thickness of the thus obtained polarizer is preferably 2 μm or more and 40 μm or less.

Polyvinyl alcohol resin is obtained by saponifying polyvinyl acetate resin. As the polyvinyl acetate 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 the other monomer copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

The saponification degree of the polyvinyl alcohol resin is usually 85 mol% or more and 100 mol% or less, and 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 polymerization degree of the polyvinyl alcohol-based resin is usually about 1,000 or more and 10,000 or less, preferably 1,500 or more and 5,000 or less.

A film produced from such a polyvinyl alcohol resin is used as a raw film for polarizing plates. The method for forming the polyvinyl alcohol-based resin into a film is not particularly limited, and the film can be formed by a known method. The film thickness of the polyvinyl alcohol-based raw film can be, for example, about 10 μm or more and 150 μm or less.

Uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before dyeing with the dichroic dye, simultaneously with dyeing, or after dyeing. When the uniaxial stretching is performed after dyeing, the uniaxial stretching may be performed before the boric acid treatment or during the boric acid treatment. It is also possible to carry out uniaxial stretching in these plural stages. In uniaxial stretching, stretching may be performed uniaxially between rolls having different peripheral speeds, or uniaxial stretching may be performed using a heat roll. The uniaxial stretching may be dry stretching in which the stretching is performed in the air, or wet stretching in which the polyvinyl alcohol resin film is swollen with a solvent. The draw ratio is usually about 3 to 8 times.

The thickness of a polarizing plate provided with a stretched film as a polarizer may be, for example, 1 μm or more and 400 μm or less, or may be 5 μm or more and 100 μm or less.

The material of the protective film to be attached to one side or both sides of the polarizer is not particularly limited, for example, cyclic polyolefin resin film, triacetyl cellulose, cellulose acetate-based resin consisting of diacetyl cellulose. Films known in the art such as resin films, polyester resin films made of resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, polycarbonate resin films, (meth) acrylic resin films, polypropylene resin films, etc. Can be mentioned. From the viewpoint of thinning, the thickness of the protective film is usually 300 μm or less, preferably 200 μm or less, more preferably 100 μm or less, and usually 5 μm or more, preferably 20 μm or more. . The protective film may or may not have a retardation.

(2) Polarizing Plate Having Film Formed from Liquid Crystal Layer as Polarizer A polarizing plate having a film formed from liquid crystal layer as a polarizer will be described. As a film coated with a dye having absorption anisotropy, which is used as a polarizer, a composition containing a dichroic dye having liquid crystallinity or a composition containing a dichroic dye and a liquid crystal compound is used as a base material. Examples thereof include films obtained by applying and curing. The film may be used as a polarizing plate by peeling the base material or together with the base material, or may be used as a polarizing plate with a structure having a protective film on one side or both sides thereof. The protective film may be the same as the polarizing plate including the above-mentioned stretched film as a polarizer.

It is preferable that the film obtained by applying and curing a dye having absorption anisotropy is thin, but if it is too thin, the strength tends to decrease and the processability tends to deteriorate. The thickness of the film is usually 20 μm or less, preferably 5 μm or less, and more preferably 0.5 μm or more and 3 μm or less.

Specific examples of the film obtained by applying the dye having the absorption anisotropy include those described in JP 2012-33249 A and the like.

The thickness of a polarizing plate provided with a film formed of a liquid crystal layer as a polarizer may be, for example, 1 μm or more and 50 μm or less.

A circular polarizing plate can be obtained by laminating a retardation film described later (for example, a retardation film including a λ / 4 plate as a retardation layer) on a polarizing plate. At this time, the angle formed by the absorption axis of the polarizer and the slow axis of the λ / 4 plate can be 45 ° ± 10 °.

(Touch sensor panel)
The touch sensor panel is not limited in detection method as long as it is a sensor that can detect a touched position, and includes a resistive film method, a capacitive coupling method, an optical sensor method, an ultrasonic method, and an electromagnetic induction coupling. Examples of the touch sensor panel include a touch panel and a surface acoustic wave type touch sensor panel. A resistance film type or a capacitive coupling type touch sensor panel is preferably used because of its low cost.

An example of a resistive film type touch sensor panel is a pair of substrates arranged to face each other, an insulating spacer sandwiched between the pair of substrates, and a transparent film provided as a resistive film on the inner front surface of each substrate. It is composed of a conductive film and a touch position detection circuit. In an image display device provided with a resistive film type touch sensor panel, when the surface of the front plate 10 is touched, the opposing resistive films are short-circuited and a current flows through the resistive film. The touch position detection circuit detects the change in voltage at this time, and the touched position is detected.

An example of a capacitive coupling type touch sensor panel is composed of a substrate, a position detection transparent electrode provided on the entire surface of the substrate, and a touch position detection circuit. In an image display device provided with a capacitive coupling type touch sensor panel, when the surface of front plate 10 is touched, the transparent electrode is grounded via the electrostatic capacitance of the human body at the touched point. The touch position detection circuit detects the grounding of the transparent electrode and the touched position is detected.

The thickness of the touch sensor panel may be, for example, 5 μm or more and 2,000 μm or less, or may be 5 μm or more and 100 μm or less.

(Retardation film)
The retardation film may include one layer or two or more retardation layers. The retardation layer may be a positive A plate such as a λ / 4 plate or a λ / 2 plate, and a positive C plate. The retardation layer may be formed of the resin film exemplified as the material of the protective film described above, or may be formed of a layer in which a polymerizable liquid crystal compound is cured. The retardation film may further include an alignment film and a base film.

The thickness of the retardation film may be, for example, 1 μm or more and 50 μm or less.

(Color layer)
When used for a display device, for example, the coloring layer 40 has a function of improving the visibility of the displayed image and the like and preventing the wiring and the like in the display device from being seen from the outside of the display device. The colored layer 40 may have an optical density of 3 or more, and preferably 5.0 or more.

The shape and color of the colored layer 40 are not limited, and can be appropriately selected depending on, for example, the use and design of the display device using the laminate. The coloring layer 40 contains a coloring agent. The colored layer 40 may be composed of only one layer, or may be composed of two or more layers. When the colored layer 40 is composed of two or more layers, at least one layer of the two or more layers is a colorant-containing layer containing a colorant and the remaining layers contain a colorant, It may not contain a coloring agent. Examples of the color of the colorant include black, red, white, navy blue, silver and gold. The colored layer 40 may have a colorant-containing layer having a high light-shielding property, a base layer for improving adhesion, or the like below the colorant-containing layer containing a colorant. Moreover, you may have a transparent protective layer which covers a coloring agent containing layer.

The colorant can be appropriately selected according to the desired color. Examples of the colorant include inorganic pigments such as titanium dioxide, zinc white, carbon black such as acetylene black, iron black, rouge, chrome vermilion, ultramarine blue, cobalt blue, yellow lead, and titanium yellow; phthalocyanine blue, indance. Organic pigments or dyes such as lenblue, isoindolinone yellow, benzidine yellow, quinacridone red, polyazo red, perylene red, aniline black; metal pigments composed of scale-like foil pieces such as aluminum and brass; titanium dioxide coated mica, basic carbonic acid Examples include pearlescent pigments (pearl pigments) made of flaky foil pieces such as lead. In the present specification, the metal contained in the plating layer is also contained in the colorant.

Each layer of the colored layer 40 can be formed by a method such as a printing method, a coating method, or a plating method. The colored layer 40 may be partially formed on the surface of the back plate 30 on the adhesive layer 20 side, or the colored layer 40 may be partially formed on the surface of the front plate 10 on the adhesive layer 20 side. It may have been done.
The colored layer 40 may be directly formed on the surface of the front plate 10 on the side of the pressure-sensitive adhesive layer 20 or on the surface of the back plate 30 on the side of the pressure-sensitive adhesive layer 20, or may be formed on another substrate. It may be transferred and formed on the surface of the front plate 10 on the side of the adhesive layer 20 or on the surface of the back plate 30 on the side of the adhesive layer 20. Specific examples of the printing method include gravure printing, offset printing, screen printing, and transfer printing from a transfer sheet. Printing by the printing method may be repeated to obtain the colored layer 40 having a desired thickness. Examples of the ink used in the printing method include an ink containing a colorant, a binder, a solvent, and any additive. The colored layer 40 is preferably partially formed on the surface of the back plate 30 on the side of the second pressure-sensitive adhesive layer 22 from the viewpoint of reducing steps.

Examples of the binder include chlorinated polyolefin (for example, chlorinated polyethylene and chlorinated polypropylene), polyester resin, urethane resin, acrylic resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer, and cellulose resin. . The binder resin may be used alone or in combination of two or more kinds. The binder resin may be a thermopolymerizable resin or a photopolymerizable resin.

When the colorant-containing layer is formed by a printing method, it is preferable to use an ink containing 50 parts by mass or more and 200 parts by mass or less of the colorant with respect to 100 parts by mass of the binder resin.

Specific examples of the plating method include known plating methods such as electrolytic plating, electroless plating, hot dip plating, chemical vapor deposition and physical vapor deposition. Examples of the physical vapor deposition include an evaporation system including a method of heating and evaporating an evaporation source such as vacuum evaporation, molecular beam evaporation, and ion beam evaporation, and a sputtering system such as magnetron sputtering and ion beam sputtering. These methods can combine patterning as needed. In this specification, a layer formed by a plating method is called a plating layer.

When the colored layer 40 is provided on the peripheral portion of the front plate 10 or the back plate 30, the colored layer 40 is not limited to being provided on the entire peripheral portion, and may be provided only on a part of the peripheral portion according to a desired design or the like. It may be in the form. When the colored layer 40 is provided on the peripheral portion of the front plate 10 or the rear plate 30, the width thereof can be appropriately determined according to the size of the display area, the desired design, etc., for example, in the range of 1 mm or more and 20 mm or less. Preferably there is.

The thickness of the colored layer 40 may be, for example, 50 μm or less, preferably 30 μm or less, and more preferably 25 μm or less. When the thickness of the coloring layer 40 is within the above numerical range, bubbles tend to be easily suppressed at the interface with the pressure-sensitive adhesive layer. The colored layer 40 may have a thickness of, for example, 0.1 μm or more, and preferably 3 μm or more. When the thickness of the colored layer 40 is 0.1 μm or more, the colored layer 40 is easily visually recognized, which contributes to the improvement of the design and also contributes to the improvement of the optical density.

Although FIG. 1 illustrates the case where the colored layer 40 has a uniform thickness and a rectangular cross-sectional shape, the colored layer 40 does not have to have a uniform thickness, and for example, the thickness decreases toward the inside. The cross-sectional shape may be such that it has a tapered portion. By having the taper portion, it tends to be easy to suppress the entrapment of air that is likely to occur during stacking. When the thickness of the colored layer 40 is not uniform, the numerical range described above as the thickness of the colored layer 40 is the maximum thickness of the colored layer 40.

<Display device>
A display device according to another aspect of the present invention includes a stacked body 100. The laminated body 100 can be arranged on the viewing side of the display device so that the front plate is on the outside. The display device is not particularly limited, and examples thereof include an organic electroluminescence (organic EL) display device, an inorganic electroluminescence (inorganic EL) display device, a liquid crystal display device, and an electroluminescent display device. The display device may have a touch panel function. The laminated body 100 is suitable for a display device having flexibility.

<Method of manufacturing laminated body>
The first embodiment of the method for manufacturing the laminated body 100 includes the following steps.
1) Step of partially forming the colored layer 40 on one surface of the back plate 30 (FIG. 2A)
2) A step of preparing the second pressure-sensitive adhesive sheet 60 having the second pressure-sensitive adhesive layer 22 between the release film 61 and the release film 62 (FIG. 2B).
3) A step of peeling the release film 62 and bonding the second adhesive sheet 60 to the surface of the back plate 30 on the side of the colored layer 40 (FIG. 2C).
4) A step of preparing the first pressure-sensitive adhesive sheet 70 having the first pressure-sensitive adhesive layer 21 between the peeling films 71 and 72 (FIG. 2D).
5) A step of bonding the second adhesive layer 22 of the second adhesive sheet 60 from which the release film 61 has been peeled off and the first adhesive layer 21 of the first adhesive sheet 70 from which the release film 72 has been peeled (see FIG. e))
6) A step of peeling the release film 71 and bonding the front plate 10 to the surface of the first adhesive layer 21 (FIG. 2 (f)).

The second embodiment of the method for manufacturing the laminated body 100 includes the following steps.
1) Step of partially forming the colored layer 40 on one surface of the back plate 30 (FIG. 3A)
2) A step of preparing the second pressure-sensitive adhesive sheet 60 having the second pressure-sensitive adhesive layer 22 between the release film 61 and the release film 62 (FIG. 3B).
3) A step of peeling the release film 62 and bonding the second adhesive sheet 60 to the surface of the back plate 30 on the side of the colored layer 40 (FIG. 3C).
4) A step of preparing the first pressure-sensitive adhesive sheet 70 having the first pressure-sensitive adhesive layer 21 between the release films 71 and 72 (FIG. 3D).
5) A step of peeling off the release film 72 and bonding the first adhesive sheet 70 to the surface of the front plate 10 (FIG. 3 (e)).
6) A step of bonding the second pressure-sensitive adhesive layer 22 of the second pressure-sensitive adhesive sheet 60 from which the release film 61 has been peeled off and the first pressure-sensitive adhesive layer 21 of the first pressure-sensitive adhesive sheet 70 from which the release film 71 has been peeled (Fig. 3 ( f))

When laminating the first pressure-sensitive adhesive layer 21 and the second pressure-sensitive adhesive layer 22, or when bonding the pressure-sensitive adhesive layer 20 to the front plate 10 or the back plate 30, a corona treatment or a plasma treatment is performed on the bonding surface. Etc. can be processed.

The first pressure-sensitive adhesive sheet 70 and the second pressure-sensitive adhesive sheet 60 are prepared by, for example, dissolving or dispersing the pressure-sensitive adhesive composition in an organic solvent such as toluene or ethyl acetate to prepare a pressure-sensitive adhesive liquid, and subjecting the liquid to a release treatment for release. A layer made of a pressure-sensitive adhesive is formed in a sheet shape on the film 71 or 72 and the peeling film 61 or 62, and another peeling film 72 or 71 and the peeling film 62 or 61 are attached to the pressure-sensitive adhesive layer. It can be manufactured by a combination method or the like.

In the first and second embodiments of the method for manufacturing the laminated body 100, in step 1), instead of partially forming the coloring layer 40 on one surface of the back plate 30, the coloring layer 40 is formed on the front plate 10. It can also be partially formed on one surface of the.

The present invention will be described more specifically by showing Examples and Comparative Examples, but the present invention is not limited to these Examples.

<Thickness>
The laminate was cut with a laser cutter. The cross section of the cut laminated body was observed using a transmission electron microscope (SU8010; Horiba, Ltd.), and the thickness of each layer was measured from the obtained observed image.

<Storage elastic modulus>
The storage elastic modulus (G ′) was measured under the following conditions using a rheometer (Anton Parr, MCR-301) for the samples in which the pressure-sensitive adhesive layers were stacked to have a thickness of 150 μm.
Conditions: stress 1%, frequency 1Hz

<Loss tangent>
Tan δ was measured under the following conditions using a rheometer (Anton Parr, MCR-301) for the samples in which the pressure-sensitive adhesive layers were stacked to have a thickness of 150 μm.
Conditions: stress 1%, frequency 1Hz

<Flexibility>
After fixing the laminate to a bending tester (Covotech, CFT-720C), a bending test was performed so that the distance between films when bent was 6 mm with the window film inside. After that, the following judgment was made based on the number of times of bending when cracks or floating of the adhesive occurred in the bent portion.
◎: 200,000 times or more, ○: 100,000 times or more and less than 200,000 times, ×: less than 100,000 times

<Bubbling evaluation>
The laminate was left in an oven at 85 ° C. and a humidity of 85% for about 1 hour and then taken out. The number of bubbles having a size of 10 μm or more was counted by observing the step portion of the step portion of the colored layer in an area of 1 cm × 1 cm with an optical microscope. In addition, the number described in the column of "presence or absence of bubbles" in Table 1 represents the number of bubbles.
○: 10 or less, ×: over 10

Production Example 1-1 (acrylic copolymer A1)
Nitrogen gas was refluxed, and 25 parts by weight of 4-hydroxybutyl acrylate (4-HBA) and 2-ethylhexyl acrylate (2-EHA) were added to a 500 ml 4-neck reactor equipped with a cooling device to facilitate temperature control. After 50 parts by weight, 15 parts by weight of methyl acrylate (MA) and 10 parts by weight of isobornyl acrylate (IBOA) were added, 100 parts by weight of ethyl acetate (EAc) was added as a solvent. Then, after purging with nitrogen gas for 1 hour to remove oxygen, the temperature was maintained at 60 ° C. After homogenizing the mixture, 0.07 parts by mass of a reaction initiator, azobisisobutyronitrile (AIBN), was added to 100 parts by mass of the mixture. The reaction was carried out for about 5 hours to produce an acrylic copolymer A1 having a weight average molecular weight of about 800,000.

Production Example 1-2 (acrylic copolymer A2)
Acrylic copolymer A2 was produced in the same manner as in Production Example 1-1, except that butyl acrylate (BA) was used instead of methyl acrylate (MA).

Production Example 1-3 (acrylic copolymer A3)
Acrylic copolymer A3 was produced in the same manner as in Production Example 1-1, except that hexyl acrylate (HA) was used instead of methyl acrylate (MA).

Production Example 1-4 (acrylic copolymer A4)
Acrylic copolymer A4 was produced in the same manner as in Production Example 1-1, except that lauryl acrylate (LA) was used instead of methyl acrylate (MA).

Production Example 2-1 (acrylic copolymer B1)
20 parts by mass of methyl acrylate (MA) and 40 parts by mass of 4-hydroxybutyl acrylate (4-HBA) were added to a 500 ml 4-neck reactor in which a cooling device was installed so that nitrogen gas was refluxed and temperature control was facilitated. After each adding 40 parts by mass of octyl acrylate (OA), nitrogen gas was purged for 1 hour to remove oxygen, and then maintained at 80 ° C. After uniformly mixing the mixture, 3 parts by mass of the reactive photoinitiator, hydroxycyclohexyl phenyl ketone, was added to the mixture. Then, it was irradiated with ultraviolet rays (10 mW) with stirring to produce an acrylic copolymer B1.

Production Example 2-2 (acrylic copolymer B2)
Acrylic copolymer B2 was produced in the same manner as in Production Example 2-1 except that 2-ethylhexyl acrylate (2-EHA) was used instead of methyl acrylate (MA).

Production Example 2-3 (acrylic copolymer B3)
Acrylic copolymer B3 was produced in the same manner as in Production Example 2-1 except that lauryl acrylate (LA) was used instead of methyl acrylate (MA).

(First adhesive sheet)
A mixture obtained by adding 0.5 parts by mass of a crosslinking agent (CORONATE-L, Tosoh Corp.) to 100 parts by mass of the acrylic copolymer shown in Table 1 on a release film coated with a silicone release agent. Applied. The applied mixture was dried at 100 ° C. for 1 minute. The thickness after drying was 25 μm. By joining a release film thereon, a first pressure-sensitive adhesive sheet (length 177 mm × width 105 mm) was produced.

(Second adhesive sheet)
On a release film coated with a silicone release agent, 10 parts by weight of a reactive diluent (isodecyl acrylate) and 100 parts by weight of an acrylic copolymer shown in Table 1 and a photopolymerization initiator (hydroxycyclohexylphenyl) were used. (Ketone) 0.1 part by mass was added to apply the mixture. A high-pressure mercury UV lamp was used to irradiate the light amount shown in Table 1 to obtain a second adhesive sheet (length 177 mm × width 105 mm) having a thickness of 25 μm.

(Preparation of Colorant-Containing Layer Forming Composition (Black))
[Ink component]
Acetylene black 15 mass%
Polyester 75 mass%
Glutaric acid dimethyl ester 2.5 mass%
Succinic acid 2% by mass
Isophorone 5.5 mass%
[Curing agent]
Aliphatic polyisocyanate 75% by mass
Ethyl acetate 25% by mass
[solvent]
Isophorone [Preparation method]
10 parts by mass of a curing agent and 10 parts by mass of a solvent were added to 100 parts by mass of the ink component, and the mixture was stirred to obtain a colorant-containing layer forming composition (black).

(Preparation of protective layer forming composition (transparent))
[Ink component]
90% by weight of polyester
Glutaric acid dimethyl ester 2.5 mass%
Succinic acid 2% by mass
Isophorone 5.5 mass%
[Curing agent]
Aliphatic polyisocyanate 75% by mass
Ethyl acetate 25% by mass
[solvent]
Isophorone [Preparation method]
10 parts by mass of a curing agent and 10 parts by mass of a solvent were added to 100 parts by mass of the ink component, and the mixture was stirred to obtain a composition for forming a protective layer.

(Front plate)
A 70 μm thick window film (base film 50 μm, each hard coat layer 10 μm, length 177 mm × width 105 mm) having hard coat layers formed on both sides of the base film was prepared as a front plate. The base film of the window film is a polyimide resin film, and the hard coat layer is a layer formed from a composition containing a dendrimer compound having a polyfunctional acrylic group at the end.

(Back plate)
A circularly polarizing plate prepared as follows was used as a back plate.
After forming a photo-alignment film on the substrate, a composition containing a dichroic dye and a polymerizable liquid crystal compound was applied to the substrate, aligned and cured to obtain a polarizer having a thickness of 2 μm. A 25 μm-thick triacetyl cellulose (TAC) film was attached onto the polarizer via an adhesive layer. A phase difference film (thickness: 17 μm, layer structure: overcoat layer (cured layer of acrylic resin composition, thickness: 1 μm) including a layer in which a substrate is peeled off and an exposed surface is polymerized and cured by a liquid crystal compound. / Adhesive layer (thickness 5 μm) / λ / 4 plate (thickness 3 μm) consisting of cured layer of liquid crystal compound and alignment film / Adhesive layer (thickness 5 μm) / From cured liquid crystal compound layer and alignment film A positive C plate (thickness 3 μm)) was attached. The circularly polarizing plate thus prepared (layer structure of "TAC / polarizer / retardation film", thickness 44 μm, length 177 mm × width 105 mm) was prepared as a back plate. The angle formed by the absorption axis of the polarizer and the slow axis of the λ / 4 plate was 45 °.

(Laminate)
After peeling off one of the release films of the second adhesive sheet, the exposed second adhesive layer was subjected to corona treatment.

On the surface of the TAC of the circularly polarizing plate, the colorant-containing layer forming composition (black) prepared above is used as an ink and screen-printed using a 460-mesh screen so that the coating thickness after drying is 3 μm. The amount of printing was performed to form a black print layer having a thickness of 3 μm and a width of 5 mm in the non-display area.

On the TAC surface of the circularly polarizing plate on which the black printed layer is formed, an electron beam vapor deposition device (product name: UNIVAC2050, manufactured by UNIVAC) is used to form a vapor deposition layer having a thickness of 80Å using TiO ₂ as a vapor deposition source. Then, a vapor deposition layer with a thickness of 500 Å is formed on it with In as a vapor deposition source, a vapor deposition layer with a thickness of 150 Å is formed on it with TiO ₂ as a vapor deposition source, and an Al ₂ O ₃ vapor deposition source is formed on it. As a result, a vapor deposition layer having a thickness of 150Å was formed. In this way, a four-layer gold vapor deposition layer (plating layer, thickness <1 μm) was formed in the entire area including the non-display area and the display area.
Then, the composition for forming a protective layer (transparent) prepared above was used as an ink in a non-display area on the surface of the gold vapor deposition layer by screen printing using a 460 mesh screen to obtain a coating thickness after drying of 5 μm. The printing was performed with the following discharge amount to form a protective layer, and the gold deposition layer in the region (display region) where the protective layer was not formed was removed by etching. Thus, in the non-display area, the layer structure of “black printed layer (thickness 3 μm) / gold vapor deposition layer (thickness <1 μm) / protective layer (thickness 5 μm)” (total thickness more than 8 μm and less than 9 μm The colored layer 40 of 4) was formed.

Corona treatment was applied to the surface of the circularly polarizing plate on the black print layer side. The second pressure-sensitive adhesive layer and the circularly polarizing plate were attached to each other so that the surface subjected to the corona treatment was the attachment surface.

After peeling off the other release film of the second adhesive sheet, the exposed second adhesive layer was subjected to corona treatment. Corona treatment was applied to the first adhesive layer in the first adhesive sheet. The second pressure-sensitive adhesive layer and the first pressure-sensitive adhesive layer were bonded together such that the surface subjected to corona treatment became the bonding surface.

The release film was peeled off from the first adhesive sheet, and the exposed first adhesive layer was subjected to corona treatment. Corona treatment was applied to one surface of the window film. The first pressure-sensitive adhesive layer and the window film were bonded together so that the surface subjected to corona treatment became the bonding surface.

In this way, a laminated body composed of the window film / first adhesive layer / second adhesive layer / circularly polarizing plate was produced.

All corona treatments were performed under the following conditions.
Frequency: 20 kHz / Voltage: 8.6 kV / Power: 2.5 kW / Speed: 6 m / min

<Compression modulus>
A measurement sample (size 50 mm × 50 mm) was cut out from the pressure-sensitive adhesive layer used in each example and comparative example. Regarding the sample for measurement, the indenter was pressed in the direction of indentation using a micro hardness tester (HM-500, manufactured by Helmut Fischer, indenter type: diamond regular quadrangular pyramid) according to ISO-FDIS 14577-1 2013 (E). The test was carried out as follows at a measurement temperature of 25 ° C. so as to be perpendicular to the main surface (surface perpendicular to the thickness direction) of the measurement sample. Even when the measurement is performed so that the pushing direction of the indenter is perpendicular to the side surface of the measurement sample (the plane parallel to the thickness direction), the measured value is the indentation direction of the main surface of the measurement sample. This is the same as when the measurement is performed so as to be perpendicular to.
While the indenter was in contact with the measurement sample and applying a load, after reaching the set test force (1 mN), it was held for 5 seconds for unloading. The slope of the tangent line at the maximum test force was obtained from the stress-strain curve obtained during unloading and defined as the compressive elastic modulus (E '= δ / ε). The results are shown in Table 2.

10 front plate, 21 first adhesive layer, 61, 62, 71, 72 release film, 70 first adhesive sheet, 22 second adhesive layer, 60 second adhesive sheet, 30 back plate, 40 colored layer, 100 laminated body.

Claims (7)

The front plate, the pressure-sensitive adhesive layer, and the back plate are laminated in this order, and has a colored layer partially formed on either the pressure-sensitive adhesive layer side of the front plate or the pressure-sensitive adhesive layer side of the back plate. An optical laminate,
The pressure-sensitive adhesive layer includes a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer, and the second pressure-sensitive adhesive layer is laminated so as to be on the colored layer side,
The pressure-sensitive adhesive layer is arranged so as to cover at least an end portion inside the colored layer in a plan view of the optical laminate,
The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer include a (meth) acrylic resin,
An optical laminate satisfying the following (1) and (2).
(1) 0.01 MPa ≤ storage elastic modulus of first adhesive layer and second adhesive layer ≤ 0.1 MPa (2) 0.5 ≤ loss tangent of second adhesive layer ≤ 0.8 The optical laminate according to claim 1, wherein the loss tangent of the first pressure-sensitive adhesive layer is different from the loss tangent of the second pressure-sensitive adhesive layer. The optical laminate according to claim 1 or 2, wherein the thickness of the second pressure-sensitive adhesive layer is larger than the thickness of the colored layer. The optical laminate according to any one of claims 1 to 3, wherein the total thickness of the first adhesive layer and the second adhesive layer is 25 µm or more and 150 µm or less. A display device comprising the optical laminate according to any one of claims 1 to 4. The optical laminate according to any one of claims 1 to 4, wherein the compression elastic modulus of the first pressure-sensitive adhesive layer is 3 MPa or more and 12 MPa or less. The optical laminate according to any one of claims 1 to 4 and 6, wherein the second adhesive layer has a compressive elastic modulus of 3 MPa or more and 5 MPa or less.

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