TW202106504A - Optical laminate and display device - Google Patents

Abstract

The purpose of the present invention is to provide an optical laminate that is provided sequentially with a front surface plate, a polarizing plate, and a touch sensor panel and that has excellent shock resistance. This optical laminate is sequentially provided with: a front surface plate; a polarizing plate; a first adhesive layer; and a touch sensor panel. The polarizing plate is provided with a protective layer on the outermost surface on the first adhesive layer side. The protective layer satisfies formula (1a): a*b ≥ 700, where a [mJ/mm3] represents toughness, and b [[mu]m] represents thickness.

Description

Optical laminate and display device

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

Japanese Patent Application Laid-Open No. 2017-054140 (Patent Document 1) describes a touch panel laminate used for an optical display device. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2017-054140

[The problem to be solved by the invention] An object of the present invention is to provide an optical laminate having a front surface plate, a polarizing plate, and a touch sensor panel in this order, and having excellent impact resistance, and a display device including the optical laminate. [Means to solve the problem]

The present invention provides the following optical laminate and display device.

[1] An optical laminate, in turn comprising: a front surface plate, a polarizing plate, a first adhesive layer, and a touch sensor panel, wherein the polarizing plate is on the outermost surface of the first adhesive layer Including the protective layer. Regarding the protective layer, when the toughness is set to a [mJ/mm ³ ] and the thickness is set to b [μm], the relationship of the following formula (1a) is satisfied, a×b≧700 ( 1a).

[2] The optical laminate according to [1], further comprising a second adhesive layer, the second adhesive layer being disposed on the side of the touch sensor panel and the first adhesive layer On the opposite side of the surface, When the thickness of the first adhesive layer is set to t1 [μm] and the thickness of the second adhesive layer is set to t2 [μm], the following formula (2a) and the following formula (3a) are satisfied Relationship, t1/t2≧0.1 (2a) t1/t2≦2 (3a). [3] The optical laminate according to [1] or [2], wherein the protective layer is provided with a retardation layer on a surface opposite to the first adhesive layer side. [4] The optical laminate according to [3], wherein the retardation layer includes a cured product of a polymerizable liquid crystal compound. [5] The optical laminate according to any one of [1] to [4], wherein the retardation layer is a positive C layer or a quarter-wavelength layer. [6] The optical laminate according to any one of [1] to [5], wherein the touch sensor panel includes a substrate layer and a transparent conductive layer provided on the substrate layer. [7] A display device comprising the optical laminate according to any one of [1] to [6]. [Effects of the invention]

According to the present invention, an optical laminate having excellent impact resistance and a display device including the optical laminate can be provided.

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 following drawings, the scales are appropriately adjusted to make the constituent elements easy to understand, and the scales of the respective constituent elements shown in the drawings may not necessarily match the scales of the actual constituent elements.

＜Optical laminated body＞ Fig. 1 is a schematic cross-sectional view of an optical laminate according to an embodiment of the present invention. The optical laminate 100 shown in FIG. 1 sequentially includes a front surface plate 10, a bonding layer 43, a polarizing plate 20, a first adhesive layer 41, a touch sensor panel 30, and a second adhesive layer 42. The optical layered body 100 of the present invention may have a configuration without the second adhesive layer 42 or a configuration without the bonding layer 43.

The polarizing plate 20 includes a protective layer 201 on the outermost surface on the side of the first adhesive layer 41, and further includes a polarizing layer 200 including a polarizer. The touch sensor panel 30 includes a base layer 32 and a transparent conductive layer 31 provided on the surface of the base layer 32 on the side of the first adhesive layer 41. The touch sensor panel 30 may have a configuration without the base material layer 32.

The protective layer 201 of the polarizing plate 20 and the base layer 32 of the touch sensor panel 30 are usually a single layer, but for multiple layers including surface treatment layers, and multiple layers including multiple layers laminated without an adhesive layer, It is assumed that the protective layer 201 or the base layer 32 is constituted by multiple layers as a whole.

Regarding the protective layer 201 of the polarizing plate 20, when the toughness is set to a [mJ/mm ³ ] and the thickness is set to b [μm], the relationship of the following formula (1a) is satisfied. In this specification, the toughness a [mJ/mm ³ ] is a value measured by the method described in the below-mentioned Examples at normal temperature (temperature 23°C). a×b≧700 (1a).

In the optical layered body, by making the protective layer 201 satisfy the relationship of the formula (1a), the impact resistance can be improved. In the optical laminate, from the viewpoint of further improving impact resistance, the protective layer 201 preferably satisfies the relationship of the formula (1b), and more preferably satisfies the relationship of the formula (1c). The protective layer 201 may also satisfy the relationship of formula (1d). a×b≧1000 (1b) a×b≧2000 (1c) a×b≦5000 (1d)

In the optical laminate, from the viewpoint of improving the bending resistance, it is preferable to set the thickness of the first adhesive layer 41 to t1 [μm] and the thickness of the second adhesive layer 42 to t2 [μm] ，Satisfy the relationship of the following formula (2a) and the following formula (3a). t1/t2≧0.1 (2a) t1/t2≦2 (3a).

In the optical laminate, from the viewpoint of further improving the bending resistance, it is more preferable to satisfy the relationship of the following formula (3b), more preferably to satisfy the relationship of the following formula (3c), and still more preferably to satisfy the following formula ( 3d) relationship. The optical layered body may satisfy the relationship of the following formula (3e) and the following formula (3f). t1/t2≦1.5 (3b) t1/t2≦1 (3c) t1/t2≦0.8 (3d) t1/t2≦0.5 (3e) t1/t2≧0.2 (3f)

It is preferable that the optical laminate 100 can be bent at least in a direction in which the front surface plate 10 is outside. The bendable means that it can be bent in a direction in which the front surface plate 10 is outside without cracking. The optical laminate of the present invention is excellent in impact resistance, and can be made to be excellent in impact resistance and also excellent in bending resistance.

The shape of the optical laminate 100 in the surface direction may be, for example, a square shape, preferably a square shape having long sides and short sides, and more preferably a rectangular shape. When the shape of the optical layered body 100 in the plane direction is a rectangle, 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. For each layer constituting the optical layered body 100, R processing may be performed on the corner portion, or the end portion may be subjected to notching processing, or perforation processing may be performed.

The thickness of the optical layered body 100 varies depending on the functions required of the optical layered body and the use of the layered body, and therefore is not particularly limited, but is, for example, 20 μm or more and 1,000 μm or less, preferably 50 μm or more and 500 μm or less.

The optical laminate 100 can be used for, for example, a display device or the like. The display device is not particularly limited, and examples thereof include organic electroluminescence (EL) display devices, inorganic electroluminescence (inorganic EL) display devices, liquid crystal display devices, electroluminescence display devices, and the like. The optical laminate 100 is suitable for a display device having flexibility. The display device including the optical laminate of the present invention has excellent impact resistance.

The optical laminate 100 includes a front surface plate 10, a polarizing plate 20, and a touch sensor panel 30. The optical laminate 100 is used in a display device, and is preferably a structure that can be a part of the display device, and may include elements that a display device can include without limitation, such as a partially formed coloring layer, a protective film, a retardation film, etc. . These elements may be included in the polarizing layer 200 of the polarizing plate 20.

[Front Panel] The front surface plate 10 is not limited in material and thickness as long as it is a plate-shaped body capable of transmitting light, and may include only one layer or two or more layers. As an example, a resin plate-shaped body (for example, a resin plate, a resin sheet, a resin film, etc.), a glass plate-shaped body (for example, a glass plate, a glass film, etc.), etc. are mentioned. The front surface plate may be the layer constituting the most surface of the display device. The front surface plate may be a laminate of a plate-shaped body made of resin and a plate-shaped body made of glass.

The thickness of the front surface plate 10 may be, for example, 30 μm or more and 500 μm or less, preferably 40 μm or more and 200 μm or less, and more preferably 50 μm or more and 100 μm or less. In the present invention, the thickness of each layer can be measured in accordance with the thickness measurement method described in the below-mentioned Examples.

When the front surface plate 10 is a plate-shaped body made of resin, the plate-shaped body made of resin is not limited as long as it can transmit light. Examples of the resin constituting the resin plate-shaped body such as the resin film include: triacetyl cellulose, acetyl cellulose butyrate, ethylene-vinyl acetate copolymer, propylene cellulose, butyl cellulose, and ethyl acetate. Acrylic cellulose, polyester, polystyrene, polyamide, polyetherimide, poly(meth)acrylic acid, polyimide, polyether chrysene, poly chrysanthemum, polyethylene, polypropylene, polymethyl methacrylate Base pentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyether ether, polymethyl methacrylate, polyethylene terephthalate Films formed by polymers such as esters, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, and polyimide. These polymers can be used alone or in combination of two or more. From the viewpoint of improving the strength and transparency, a resin film formed of a polymer such as polyimide, polyimide, and polyimide is preferred.

The front surface plate 10 may be a film provided with a hard coat layer on at least one surface of a base film. As the base film, a film that can be made of the aforementioned resin can be used. The hard coat layer may be formed on one side of the base film or on both sides. By providing a hard coat layer, a resin film with improved hardness and scratch resistance can be made. The hard coat layer is, for example, a cured layer of ultraviolet curable resin. Examples of ultraviolet curable resins include acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, and epoxy resins. In order to increase the hardness, the hard coat layer may contain additives. The additives are not limited, and examples include inorganic fine particles, organic fine particles, or mixtures of these.

When the front surface plate 10 is a glass plate, it is preferable to use tempered glass for display as the glass plate. The thickness of the glass plate may be, for example, 10 μm or more and 1000 μm or less, 20 μm or more and 500 μm or less, or 50 μm or more and 500 μm or less. By using a glass plate, the front surface plate 10 having excellent mechanical strength and surface hardness can be constructed.

When the optical laminate 100 is used in a display device, the front surface plate 10 not only has the function of protecting the front surface (screen) of the display device (functioning as a window film), but can also be used as a touch sensor panel 30 The function of the detected touch operation surface, in addition, can also have a blue light blocking function, a viewing angle adjustment function, etc.

[Touch Sensor Panel] As the touch sensor panel 30, as long as it is a sensor that can detect the position touched on the front panel 10 and has a transparent conductive layer 31, the detection method is not limited, and examples thereof include: resistive film method, Touch sensor panels of electrostatic capacitance method, optical sensor method, ultrasonic method, electromagnetic induction coupling method, surface acoustic wave method, etc. Among them, in terms of low cost, fast response speed, and thin film, it is preferable to use an electrostatic capacitive touch sensor panel. From the viewpoint of improving impact resistance, the touch sensor panel 30 preferably includes a base layer 32 and a transparent conductive layer 31 provided on the surface of the base layer 32 on the side of the first adhesive layer 41 The composition. In the configuration in which the transparent conductive layer 31 is provided on the surface of the base layer 32, the base layer 32 and the transparent conductive layer 31 may be in contact with each other (for example, a touch sensor manufactured by the first method described later) Panel), or a configuration in which the base layer 32 and the transparent conductive layer 31 are not in contact with each other (for example, a touch sensor panel manufactured by the second method described later). The touch sensor panel 30 may include an adhesive layer, a separation layer, a protective layer, etc., which are different from the substrate layer 32 and the transparent conductive layer 31. Examples of the adhesive layer include an adhesive layer and an adhesive layer.

An example of the capacitive touch sensor panel includes a substrate layer, a transparent conductive layer for position detection provided on the surface of the substrate layer, and a touch position detection circuit. In a display device provided with an optical laminate including an electrostatic capacitive touch sensor panel, when the surface of the front surface plate 10 is touched, at the touched point, the transparent conductive layer is formed by the electrostatic capacitance of the human body. Grounded. The touch position detection circuit detects the grounding of the transparent conductive layer, thereby detecting the touched position. By having multiple transparent conductive layers separated from each other, more detailed position detection can be performed.

The transparent conductive layer may be a transparent conductive layer containing metal oxides such as indium tin oxide (ITO), or a metal layer containing metals such as aluminum, copper, silver, gold, or alloys of these.

The separation layer may be a layer formed on a substrate such as glass to separate the transparent conductive layer formed on the separation layer from the substrate together with the separation layer. The separation layer is preferably an inorganic layer or an organic layer. Examples of the material forming the inorganic layer include silicon oxide. As a material for forming the organic layer, for example, a (meth)acrylic resin composition, an epoxy resin composition, a polyimide resin composition, and the like can be used.

The touch sensor panel 30 may be provided with a protective layer contacting the transparent conductive layer 31 to protect the conductive layer. The protective layer includes at least one of an organic insulating film and an inorganic insulating film, and these films can be formed by a spin coating method, a sputtering method, an evaporation method, or the like.

The touch sensor panel 30 can be manufactured in the following manner, for example. In the first method, first, the base material layer 32 is laminated on the glass substrate via subsequent lamination. A transparent conductive layer 31 patterned by photolithography is formed on the base layer 32. The glass substrate and the base material layer 32 are separated by heating, thereby obtaining the touch sensor panel 30 including the transparent conductive layer 31 and the base material layer 32.

In the second method, a separation layer is first formed on a glass substrate, and a protective layer is formed on the separation layer as needed. A transparent conductive layer 31 patterned by photolithography is formed on the separation layer (or protective layer). A peelable protective film is laminated on the transparent conductive layer 31, transferred from the transparent conductive layer 31 to the separation layer, and the glass substrate is separated. The base layer 32 is bonded to the separation layer through the adhesive layer, and the peelable protective film is peeled off, thereby obtaining a touch sensor having a transparent conductive layer 31, a separation layer, an adhesive layer, and a base layer 32 in this order Panel 30. Furthermore, the laminate including the transparent conductive layer 31 and the separation layer can be used as the touch sensor panel 30 without being attached to the base layer 32.

Examples of the base layer 32 of the touch sensor panel include: triacetyl cellulose, polyethylene terephthalate, cycloolefin polymer, polyethylene naphthalate, polyolefin, and polycycloolefin , Polycarbonate, polyether ether, polyarylate, polyimide, polyamide, polystyrene, polynorbornene and other resin films. From the viewpoint of easy formation of a substrate layer having a desired toughness, polyethylene terephthalate is preferably used.

From the viewpoint of easy formation of an optical laminate having excellent bending resistance, the thickness of the base layer 32 of the touch sensor panel is preferably 50 μm or less, and more preferably 30 μm or less. The thickness of the base layer 32 of the touch sensor panel is, for example, 5 μm or more.

[Polarizer] As the polarizing plate 20, a film containing a stretched film to which a dichroic dye is adsorbed, or a liquid crystal layer formed by applying and curing a composition containing a dichroic dye and a polymerizable compound as a polarizing plate, etc. can be mentioned. The polarizing plate 20 includes a protective layer 201 in addition to the polarizer, and further includes a retardation layer and the like.

(Polarizer) As the dichroic dye, specifically, iodine or a dichroic organic dye can be used. Dichroic organic dyes include dichroic direct dyes containing C.I. Direct Red 39 and other bisazo compounds, and dichroic direct dyes containing compounds such as trisazo and tetrasazo. The polarizing plate obtained by coating and curing a composition containing a dichroic dye and a polymerizable compound is, for example, a liquid crystal layer that is coated with a composition containing a dichroic pigment having liquid crystallinity or a composition containing two colors A liquid crystal layer obtained by curing a composition of a sexual dye and a polymerizable liquid crystal. The liquid crystal layer obtained by applying and hardening a composition containing a dichroic dye and a polymerizable compound has no limitation in the bending direction compared to a stretched film in which the dichroic dye is adsorbed, and is therefore preferable.

(1) The polarizer is a polarizing plate with stretched film A polarizing plate provided with a stretched film that adsorbs a dichroic dye as a polarizing plate will be described. As a polarizer, a stretched film that adsorbs a dichroic dye is usually manufactured through the following steps: a step of uniaxially stretching a polyvinyl alcohol-based resin film; by using a dichroic dye to treat the polyvinyl alcohol-based resin film The step of dyeing to adsorb the dichroic pigment; the step of treating the polyvinyl alcohol-based resin film with the dichroic pigment adsorbed with the boric acid aqueous solution; and the step of washing with water after the treatment with the boric acid aqueous solution. The polarizer can be directly used as a polarizer, and a transparent protective film may be pasted on one or both sides of the polarizer as a polarizer. The thickness of the polarizing plate thus obtained is preferably 2 μm or more and 40 μm or less.

The polyvinyl alcohol-based resin is obtained by saponifying a 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 other monomers copolymerizable therewith is used. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

The degree of saponification of the polyvinyl alcohol-based resin is usually 85 mol% or more and 100 mol% or less, preferably 98 mol% or more. The polyvinyl alcohol-based resin can be modified. For example, polyvinyl formal or polyvinyl acetal modified with aldehydes can be used. The degree of polymerization of the polyvinyl alcohol-based resin is usually 1,000 or more and 10,000 or less, preferably in the range of 1,500 or more and 5,000 or less.

Those obtained by forming a film of such a polyvinyl alcohol-based resin can be used as a raw material film of a polarizing plate. The method of forming a polyvinyl alcohol-based resin into a film is not particularly limited, and a known method can be used for forming a film. The film thickness of the polyvinyl alcohol-based raw material film may be about 10 μm or more and 150 μm or less, for example.

The uniaxial stretching of the polyvinyl alcohol-based resin film can be carried out before dyeing with a dichroic dye, simultaneously with dyeing, or after dyeing. When uniaxial stretching is performed after dyeing, the uniaxial stretching may be performed before the boric acid treatment or may be performed during the boric acid treatment. In addition, it is also possible to perform uniaxial stretching in the multiple stages described above. In the case of uniaxial stretching, uniaxial stretching can be performed between rolls with different peripheral speeds, or a heated roll can be used for uniaxial stretching. In addition, uniaxial stretching can be either dry stretching or wet stretching, where dry stretching is performed in the atmosphere, and wet stretching is in a state where the polyvinyl alcohol resin film is swelled with a solvent. Stretching down. The stretching ratio is usually about 3 to 8 times.

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

The material of the protective film bonded on one or both sides of the polarizer is not particularly limited, and examples include cyclic polyolefin resin films, triacetyl cellulose, diacetyl cellulose, and other resin-containing acetic acid. Cellulose resin films, polyester resin films containing resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, polycarbonate resin films, (Meth)acrylic resin films, polypropylene resin films, and other films known in the art. 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 phase difference.

(2) The polarizer is a polarizer with a liquid crystal layer A polarizing plate provided with a liquid crystal layer as a polarizing plate will be described. As a polarizer, a liquid crystal layer formed by coating a composition containing a dichroic dye and a polymerizable compound includes: a composition containing a dichroic dye having liquid crystallinity, or a composition containing a dichroic dye And a liquid crystal layer obtained by coating and curing a composition of a liquid crystal compound on a substrate. The liquid crystal layer can be used as a polarizing plate by peeling off the base material or together with the base material, or can also be used as a polarizing plate with a structure having a protective film on one or both sides of the liquid crystal layer. As this protective film, the same protective film as the polarizing plate whose said polarizing plate is a stretched film is mentioned.

The liquid crystal layer obtained by applying and curing a composition containing a dichroic dye and a polymerizable compound is preferably thin, but if the thickness is too thin, the strength decreases and the workability tends to deteriorate. The thickness of the liquid crystal layer is usually 20 μm or less, preferably 5 μm or less, and more preferably 0.5 μm or more and 3 μm or less.

The thickness of the polarizing plate provided with the liquid crystal layer as the polarizing plate can be, for example, 1 μm or more and 50 μm or less.

(Retardation layer) The polarizing plate may include one layer or two or more retardation layers. The retardation layer is a layer that imparts a predetermined retardation to light, and can exemplify optical compensation layers such as a 1/2 wavelength layer, a quarter wavelength layer, and a positive C layer. The retardation layer may be a positive wavelength dispersion type retardation layer or a reverse wavelength dispersion retardation layer. The retardation layer may be an element of a retardation body formed together with other layers. Examples of layers other than the retardation layer in the retarder include a base layer, an alignment layer, and a protective layer. Furthermore, other layers may be layers that do not affect the retardation value.

Examples of the retardation layer include a liquid crystal layer containing a cured product of a polymerizable liquid crystal compound, or a stretched film. The retardation layer as a liquid crystal layer is generally easier to be thinner than a retardation layer as a stretched film.

When the retardation layer is a liquid crystal layer, the thickness is preferably 0.5 μm to 10 μm, more preferably 0.5 μm to 5 μm.

As the configuration of the polarizing plate 20, the following configuration including a polarizing plate and two retardation layers is exemplified. It can be enumerated: starting from the side close to the front surface plate 10 as follows: i) The combination of polarizer, 1/2 wavelength layer and 1/4 wavelength layer, ii) Combination of polarizer, 1/4 wavelength layer, positive C layer, etc. The configuration of i) and ii) can provide a circular polarizing plate. The optical laminate is provided with a circular polarizing plate as the polarizing plate 20, so that reflection of external light can be prevented.

The half-wavelength layer is a layer that gives a phase difference of π (=λ/2) to the electric field vibration direction (plane of polarization) of incident light, and has a function of changing the direction (polarization direction) of linearly polarized light. In addition, if circularly polarized light is incident, the direction of rotation of the circularly polarized light can be reversed.

The 1/2-wavelength layer is a layer in which Re(λ), which is an in-plane retardation value at a specific wavelength λ nm, satisfies Re(λ)=λ/2. Although Re(λ)=λ/2 can be realized at any wavelength in the visible light region, it is preferably realized at a wavelength of 550 nm. Re(550), which is the in-plane retardation value at a wavelength of 550 nm, preferably satisfies 210 nm≦Re(550)≦300 nm. In addition, it is more preferable to satisfy 220 nm≦Re(550)≦290 nm.

The quarter-wave layer is a layer that gives a phase difference of π/2 (=λ/4) to the electric field vibration direction (plane of polarization) of incident light, and has the function of converting linearly polarized light of a certain wavelength into circularly polarized light ( Or convert circularly polarized light into linearly polarized light).

The quarter-wavelength layer is a layer in which Re(λ), which is the in-plane retardation value at a specific wavelength λ nm, satisfies Re(λ) = λ/4. Although it can be realized at any wavelength in the visible light region, it is preferably It is realized at a wavelength of 550 nm. Re(550), which is the in-plane retardation value at a wavelength of 550 nm, preferably satisfies 100 nm≦Re(550)≦160 nm. In addition, it is more preferable to satisfy 110 nm≦Re(550)≦150 nm.

The so-called reverse wavelength dispersion is an optical characteristic in which the in-plane retardation value at a short wavelength is smaller than the in-plane retardation value at a long wavelength, and preferably satisfies the following formula (4): Re(450)≦Re(550)≦Re(650) (4).

As an optical compensation layer, a positive A layer, a positive C layer, etc. are mentioned, for example. The positive A layer satisfies Nx when the refractive index in the slow axis direction in the plane is Nx, the refractive index in the advancing axis direction in the plane is Ny, and the refractive index in the thickness direction is Nz. > The level of the relationship of Ny. The positive A layer preferably satisfies the relationship of Nx>Ny≧Nz. In addition, the positive A layer can also function as a quarter-wavelength layer. The positive C layer is a layer that satisfies the relationship of Nz>Nx≧Ny.

The optical properties of the retardation layer can be adjusted by the alignment state of the liquid crystal compound constituting the retardation layer or the stretching method of the stretched film constituting the retardation layer. By appropriately adjusting the optical characteristics of the retardation layer in the polarizing plate 20, the polarizing plate 20 with anti-reflection performance can be obtained.

(1) Retardation layer as a liquid crystal layer The case where the retardation layer is a liquid crystal layer will be described. 2 is a schematic cross-sectional view schematically showing an example of a phase difference body including a phase difference layer as a liquid crystal layer and other layers. As shown in FIG. 2, the retarder 50 is formed by sequentially laminating a base layer 51, an alignment layer 52, and a retardation layer 53 as a liquid crystal layer. The retarder 50 is not limited to the structure shown in FIG. 2 as long as it includes the retardation layer 53 as a liquid crystal layer, and may have a structure in which the base layer 51 is peeled off and only the alignment layer 52 and the retardation layer 53 are included. The base material layer 51 and the alignment layer 52 may be peeled off, and only the retardation layer 53 which is a liquid crystal layer may be included.

FIG. 3 is a schematic cross-sectional view schematically showing another example of a phase difference body including a phase difference layer as a liquid crystal layer and other layers. The retarder 55 shown in FIG. 3 is formed by laminating a base layer 56, an adhesive layer 57, and a retardation layer 53 in this order. The retardation body 55 bonds the retardation layer 53 of the retardation body 50 shown in FIG. 2 and the other base material layer 56 via the adhesive layer 57, and then peels off the base material layer 51, or peels off the base material layer 51 and the alignment layer 52 and formed. Examples of the adhesive layer 57 include an adhesive layer and an adhesive layer.

The base layer 51 functions as a support layer that supports the alignment layer 52 formed on the base layer 51 and the retardation layer 53 as a liquid crystal layer. The base layer 51 is preferably a film formed of a resin material.

As the resin material of the base material layer 51, for example, a resin material excellent in transparency, mechanical strength, thermal stability, stretchability, and the like is used. Specifically, examples include: polyolefin resins such as polyethylene and polypropylene; cyclic polyolefin resins such as norbornene-based polymers; polyethylene terephthalate, polyethylene naphthalate, and other polyolefin resins; Ester resins; (meth)acrylic resins such as (meth)acrylic acid and polymethyl (meth)acrylate; celluloses such as triacetyl cellulose, diacetyl cellulose and cellulose acetate propionate Ester resins; Vinyl alcohol resins such as polyvinyl alcohol and polyvinyl acetate; Polycarbonate resins; Polystyrene resins; Polyarylate resins; Polyurethane resins; Polyether oxide resins; Polyamides -Based resin; polyimide-based resin; polyetherketone-based resin; polyphenylene sulfide-based resin; polyphenylene ether-based resin, and mixtures and copolymers thereof. Among these resins, it is preferable to use any one or a mixture of cyclic polyolefin resins, polyester resins, cellulose ester resins, and (meth)acrylic resins. In addition, the term "(meth)acrylic acid" means "at least one of acrylic acid and methacrylic acid".

The base layer 51 may be a single layer mixed with one or two or more of the above-mentioned resins, or may have a multilayer structure of two or more layers.

Any additives can be added to the resin material forming the resin film. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, and coloring agents.

The thickness of the base layer 51 is not particularly limited, but generally, it is preferably from 5 μm to 200 μm, more preferably from 10 μm to 200 μm, and still more preferably from 10 μm to 150 μm in terms of handling properties such as strength and handling properties.

In order to improve the adhesion between the base layer 51 and the alignment layer 52, at least the surface of the base layer 51 on the side where the alignment layer 52 is formed may be corona treated, plasma treated, flame treated, etc., or a primer may be formed Layers and so on. Furthermore, when the base layer 51 is peeled, or the base layer 51 and the alignment layer 52 are peeled to form a retardation layer, the peeling can be made easy by adjusting the adhesion force at the peeling interface. For the material, thickness, treatment, and the like of the base layer 56, the description of the base layer 51 can be applied.

The alignment layer 52 has an alignment restricting force for aligning the liquid crystal compound contained in the phase difference layer 53 as a liquid crystal layer formed on the alignment layers 52 in a desired direction. Examples of the alignment layer 52 include an alignment polymer layer formed of an alignment polymer, a photoalignment polymer layer formed of a photoalignment polymer, and a groove having a concave-convex pattern or a plurality of grooves on the surface of the layer. Alignment layer. The thickness of the alignment layer 52 is usually 0.01 μm-10 μm, preferably 0.01 μm-5 μm.

The aligning polymer layer can be formed by dissolving the aligning polymer in a solvent, coating the resulting composition on the base layer 51, removing the solvent, and performing rubbing treatment as necessary. In this case, in the aligning polymer layer formed of the aligning polymer, the alignment restriction force can be arbitrarily adjusted according to the surface state of the aligning polymer and the friction conditions.

The photo-alignment polymer layer can be formed by applying a composition including a polymer or monomer having a photoreactive group and a solvent to the base layer 51 and irradiating it with polarized light. In this case, in the photo-alignment polymer layer, the alignment restriction force can be arbitrarily adjusted by the polarized light irradiation conditions of the photo-alignment polymer.

The groove alignment layer can be formed, for example, by a method or the like in which a concave-convex pattern is formed by exposing, developing, etc., on the surface of the photosensitive polyimide film through an exposure mask having a slit in a pattern shape; A method of forming an uncured layer of active energy ray curable resin on a plate-shaped master disk with grooves on the surface, and transferring the layer to the base layer 51 and then hardening; forming active energy rays on the base layer 51 The uncured layer of curable resin is a method of forming unevenness and curing by pressing a roller-shaped master disk having unevenness on the layer.

The retardation layer 53 as the liquid crystal layer is not particularly limited as long as it imparts a predetermined retardation to light, and examples thereof include optical compensation layers such as a 1/2 wavelength layer, a quarter wavelength layer, and a positive C layer.

The retardation layer 53 as a liquid crystal layer can be formed using a well-known liquid crystal compound. The type of the liquid crystal compound is not particularly limited, and rod-shaped liquid crystal compounds, disc-shaped liquid crystal compounds, and mixtures thereof can be used. In addition, the liquid crystal compound may be a polymer liquid crystal compound, or a polymerizable liquid crystal compound, or a mixture of these. As the liquid crystal compound, for example, Japanese Patent Application Publication No. 11-513019, Japanese Patent Application Publication No. 2005-289980, Japanese Patent Application Publication No. 2007-108732, Japanese Patent Application Publication No. 2010-244038, Japanese Patent Publication No. Japanese Patent Application Publication No. 2010-31223, Japanese Patent Application Publication No. 2010-270108, Japanese Patent Application Publication No. 2011-6360, Japanese Patent Application Publication No. 2011-207765, Japanese Patent Application Publication No. 2016-81035, International Publication A liquid crystal compound described in No. 2017/043438 and Japanese Patent Publication No. 2011-207765.

For example, in the case of using a polymerizable liquid crystal compound, a composition containing the polymerizable liquid crystal compound is applied on the alignment layer 52 to form a coating film, and the coating film is cured, whereby the retardation layer 53 can be formed. The retardation layer 53 formed in this manner includes a cured product of a polymerizable liquid crystal compound. The thickness of the retardation layer 53 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, in addition to the liquid crystal compound, a polymerization initiator, a polymerizable monomer, a surfactant, a solvent, an adhesion modifier, a plasticizer, an alignment agent, and the like. As a coating method of the composition containing a polymerizable liquid crystal compound, well-known methods, such as a die coating method, are mentioned. As a curing method of a composition containing a polymerizable liquid crystal compound, a known method such as irradiation with active energy rays (for example, ultraviolet rays) can be cited.

(2) As a retardation layer of a stretched film The case where the retardation layer is a stretched film will be described. Stretched films can generally be obtained by stretching a substrate. As a method of stretching the base material, for example, a roll (winding body) that winds the base material on a roll is prepared, the base material is continuously wound from the wound body, and the wound base material is transported to a heating furnace . The setting temperature of the heating furnace is set to the range of the glass transition temperature of the substrate (℃) ~ [glass transition temperature + 100] (℃), preferably around the glass transition temperature (℃) ~ [glass transition temperature + 50] (℃) range. In this heating furnace, when the substrate is stretched in the direction of travel or in the direction orthogonal to the direction of travel, the conveying direction and tension are adjusted to be inclined at an arbitrary angle, and then uniaxial or biaxial heat stretching is performed. . The stretching ratio is usually 1.1 to 6 times, preferably 1.1 to 3.5 times.

In addition, as a method of stretching in an oblique direction, as long as it is a method that can continuously incline the alignment axis at a desired angle, it is not particularly limited, and a known stretching method can be adopted. Examples of such a stretching method include methods described in Japanese Patent Laid-Open No. 50-83482 and Japanese Patent Laid-Open No. 2-113920. When the retardation property is imparted to the film by stretching, the thickness after stretching is determined by the thickness before stretching and the stretching ratio.

The substrate is usually a transparent substrate. The so-called transparent substrate refers to a substrate having transparency capable of transmitting light, particularly visible light, and the so-called transparency refers to the characteristic that the transmittance of light with a wavelength of 380 nm to 780 nm is 80% or more. As a specific transparent substrate, a translucent resin substrate can be cited. Examples of resins constituting the light-transmitting resin substrate include polyolefins such as polyethylene and polypropylene; cyclic olefin resins such as norbornene-based polymers; polyvinyl alcohol; polyethylene terephthalate; Methacrylate; polyacrylate; cellulose esters such as triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate; polyethylene naphthalate; polycarbonate; Ether stubble; polyether ketone; polyphenylene sulfide and polyphenylene ether. From the viewpoints of easy availability and transparency, polyethylene terephthalate, polymethacrylate, cellulose ester, cyclic olefin resin, or polycarbonate is preferred.

Cellulose esters are esters obtained by esterifying part or all of the hydroxyl groups contained in cellulose, and are easily available in the market. In addition, the cellulose ester substrate can also be easily obtained from the market. Examples of commercially available cellulose ester substrates include "FUJITAC (registered trademark) film" (Fuji Film Co., Ltd.); "KC8UX2M", "KC8UY" and "KC4UY" (Konica Minolta Up to precision optics (Konica Minolta Opto (stock)) and so on.

Polymethacrylate and polyacrylate (hereinafter, polymethacrylate and polyacrylate may be collectively referred to as (meth)acrylic resin) can be easily obtained from the market.

Examples of (meth)acrylic resins include homopolymers of alkyl methacrylates or alkyl acrylates, copolymers of alkyl methacrylates and alkyl acrylates, and the like. As the alkyl methacrylate, specifically, methyl methacrylate, ethyl methacrylate, propyl methacrylate, etc. can be cited, and as the alkyl acrylate, specifically, methyl acrylate, Ethyl acrylate, propyl acrylate, etc. As the (meth)acrylic resin, resins sold on the market as general-purpose (meth)acrylic resins can be used. As the (meth)acrylic resin, what is called an impact-resistant (meth)acrylic resin can be used.

In order to further increase the mechanical strength, it is preferable to also include rubber particles in the (meth)acrylic resin. The rubber particles are preferably acrylic rubber particles. Here, the acrylic rubber particles are obtained by polymerizing acrylic monomers mainly composed of butyl acrylate and 2-ethylhexyl acrylate and other alkyl acrylates in the presence of a polyfunctional monomer. Particles with rubber elasticity. The acrylic rubber particles may be formed in a single layer of such particles having rubber elasticity, or may be a multilayer structure having at least one rubber elastic layer. Examples of acrylic rubber particles with a multilayer structure include particles having rubber elasticity as described above as the core and covering the surrounding with a hard alkyl methacrylate polymer; and hard alkyl methacrylate. The base ester polymer is the core, and the surrounding area is covered with the rubber elastic acrylic polymer as described above; and the rigid core is covered with the rubber elastic acrylic polymer, and the surrounding area is covered with the rubber elastic acrylic polymer. Hard alkyl methacrylate polymer covered particles, etc. The average diameter of the rubber particles formed by the elastic layer is usually in the range of about 50 nm to 400 nm.

The content of the rubber particles in the (meth)acrylic resin is usually about 5 to 50 parts by mass per 100 parts by mass of the (meth)acrylic resin. Since the (meth)acrylic resin and acrylic rubber particles are marketed in a mixed state of these, the commercially available products can be used. Examples of commercially available products of (meth)acrylic resin prepared with acrylic rubber particles include "HT55X" and "Teno Roy (Technology) S001" sold by Sumitomo Chemical Co., Ltd. "Teno Roy (Technology) S001" is sold in the form of a film.

Cyclic olefin resins are easily available in the market. Examples of commercially available cyclic olefin resins include "Topas" (registered trademark) [Ticona (Germany)], "Arton" (registered trademark) [JSR (Share)], "ZEONOR" (registered trademark) [ZEON (Stock)], "ZEONEX" (registered trademark) [ZEON (Japan) (Shares)] and "APEL (APEL)" (registered trademarks) [Mitsui Chemicals (shares)]. Such a cyclic olefin-based resin is formed into a film by a known method such as a solvent casting method and a melt extrusion method to form a substrate. In addition, a commercially available cyclic olefin-based resin substrate may also be used. Examples of commercially available cyclic olefin resin substrates include "ESCENA" (registered trademark) [Sekisui Chemical Industry Co., Ltd.] and "SCA40" (registered trademark) [Sekisui Chemical Industry Co., Ltd.) ], "ZEONOR FILM" (registered trademark) [OPTES (shares)] and "ARTON FILM" (registered trademarks) [JSR (shares)].

When the cyclic olefin resin is a copolymer of a cyclic olefin and a chain olefin or an aromatic compound having a vinyl group, the content ratio of the structural unit derived from the cyclic olefin relative to all the structural units of the copolymer is usually 50 mol% or less, preferably in the range of 15 mol% to 50 mol%. Examples of chain olefins include ethylene and propylene, and examples of aromatic compounds having vinyl groups include styrene, α-methylstyrene, and alkyl-substituted styrene. When the cyclic olefin resin is a terpolymer of a cyclic olefin, a chain olefin, and an aromatic compound having a vinyl group, the content of the structural unit derived from the chain olefin relative to all the structural units of the copolymer The ratio is usually 5 mol% to 80 mol%, and the content ratio of the structural unit derived from the aromatic compound having a vinyl group relative to all the structural units of the copolymer is usually 5 mol% to 80 mol%. This kind of terpolymer has the advantage of reducing the amount of expensive cyclic olefin used in its manufacture.

(The protective layer) The protective layer 201 included in the polarizing plate 200 is not particularly limited as long as it satisfies the relational expression of formula (1a). As an example of the configuration of the polarizing plate 200, the following configuration can be cited: including the retardation body 50 shown in FIG. 2 or the retardation body 55 shown in FIG. 3, the base layer 51 of the retardation body 50 or the retardation body 55 The base layer 56 is a protective layer 201. In this case, the description of the base layer 51 and the base layer 56 described above is directly applicable as the description of the protective layer 201. For example, when the polarizing plate 200 is a circular polarizing plate having the configuration of i) above, the following configuration can be mentioned: the protective layer 201 can be used as the base layer 51 and the base layer 56 supporting the quarter-wavelength layer to protect The 1/4 wavelength layer is provided on the surface of the layer 201 on the opposite side to the first adhesive layer 41 side. In addition, in the case where the polarizing plate 200 is a circular polarizing plate having the above-mentioned ii) configuration, the following configuration may be mentioned: the protective layer 201 can be used as the base material layer 51 and the base material layer 56 supporting the positive C layer, and the protective layer A positive C layer is provided on the surface of 201 opposite to the first adhesive layer 41 side. In the above configuration, the retardation layer is provided on the surface of the protective layer 201. The protective layer 201 and the retardation layer may be in contact with each other (for example, the retardation body 50 shown in FIG. 2), or the protective layer The layer 201 and the retardation layer are not in contact with each other (for example, the retardation body 55 shown in FIG. 3).

As another example of the configuration of the polarizing plate 200, a configuration in which the protective film bonded to the surface on the side of the first adhesive layer 41 of the polarizing plate is the protective layer 201 can be cited. In this case, the above description of the protective film is directly applicable to the description of the protective layer 201. In addition, as another example of the configuration of the polarizing plate 200, a configuration in which the protective layer 201 is bonded to the surface on the side of the first adhesive layer 41 of the polarizing plate 200 as a component of the polarizing plate 200 can be cited. In this case, as the protective layer 201, the same protective layer as the protective layer described in the above-mentioned base layer 51 or the above-mentioned protective film can be used.

[Adhesive layer] The first adhesive layer 41 is a layer interposed between the polarizer 20 and the touch sensor panel 30. The second adhesive layer 42 is a layer provided on the surface of the touch sensor panel 30 opposite to the polarizing plate 20 side, and can be used for bonding the optical laminate 100 to other components such as a display panel. A release film may be attached to the surface of the second adhesive layer 42.

The first adhesive layer 41 and the second adhesive layer 42 may include (meth)acrylic resins, rubber-based resins, urethane-based resins, ester-based resins, silicone-based resins, and polyvinyl ether-based resins. Such resin as the main component of the adhesive composition. Among them, an adhesive composition using a (meth)acrylic resin excellent in transparency, weather resistance, heat resistance, etc., as a base polymer is preferred. The adhesive composition can be an active energy ray hardening type or a thermal hardening type.

As the (meth)acrylic resin (base polymer) used in the adhesive composition, for example, butyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate can be preferably used. A polymer or copolymer in which one or two or more of (meth)acrylates such as octyl ester and 2-ethylhexyl (meth)acrylate are used as monomers. The base polymer is preferably copolymerized with a polar monomer. Examples of polar monomers include (meth)acrylic acid, 2-hydroxypropyl (meth)acrylate, hydroxyethyl (meth)acrylate, (meth)acrylamide, N,N-dimethyl Monomers such as amino ethyl (meth)acrylate and glycidyl (meth)acrylate having carboxyl group, hydroxyl group, amide group, amino group, epoxy group and the like.

The adhesive composition may only contain the base polymer, but usually contains a crosslinking agent. Examples of the crosslinking agent include: a metal ion having a valence of 2 or higher and forming a metal carboxylate with a carboxyl group; a polyamine compound forming an amide bond with a carboxyl group; a polyepoxy compound or Polyols, which form ester bonds with carboxyl groups; polyisocyanate compounds, which form amide bonds with carboxyl groups. Among them, polyisocyanate compounds are preferred.

The so-called active energy ray curable adhesive composition refers to the following adhesive composition, which has the property of being cured by irradiation of active energy rays such as ultraviolet rays or electron rays, and has adhesiveness before the active energy rays are irradiated It can be closely adhered to adherends such as films, and can be cured by the irradiation of active energy rays, and the properties of adhesion can be adjusted. The active energy ray curable adhesive composition is preferably an ultraviolet curable adhesive composition. The active energy ray curable adhesive composition contains an active energy ray polymerizable compound in addition to the raw material polymer and the crosslinking agent. In addition, if necessary, a photopolymerization initiator, photosensitizer, and the like are also contained.

The adhesive composition may contain fine particles, beads (resin beads, glass beads, etc.), glass fibers, resins other than raw polymers, tackifiers, fillers (metal powder or other inorganic powders, etc.) for imparting light scattering properties. , Antioxidants, UV absorbers, dyes, pigments, colorants, defoamers, corrosion inhibitors, photopolymerization initiators and other additives.

It can be formed by applying an organic solvent diluent of the adhesive composition on a substrate and drying it. When an active energy ray curable adhesive composition is used, by irradiating the formed adhesive layer with active energy rays, a cured product having a desired degree of curing can be obtained.

The first adhesive layer 41 and the second adhesive layer 42 may include the same material or different materials. The thickness t1 of the first adhesive layer 41 and the thickness t2 of the second adhesive layer are not particularly limited. For example, it is 3 μm or more and 100 μm or less, preferably 5 μm or more and 50 μm or less, or 20 μm or more. The thickness t1 of the first adhesive layer 41 and the thickness t2 of the second adhesive layer are preferably selected in a manner that satisfies the aforementioned formulas (2a) and (3a).

The storage elastic coefficients of the first adhesive layer 41 and the second adhesive layer 42 at a temperature of 25° C. are preferably 0.005 Mpa or more and 1.0 Mpa or less, more preferably 0.01 Mpa or more and 0.5 Mpa or less, and more preferably 0.01 Mpa or more and 0.2 Below MPa. The storage elasticity coefficient is measured according to the method described in the below-mentioned Examples.

[Lamination layer] The bonding layer 43 is a layer interposed between the polarizing plate 20 and the front surface plate 10. The bonding layer 43 is not particularly limited, and may be formed of, for example, an adhesive layer, a water-based adhesive layer, an active energy ray curable adhesive layer, or the like. When the bonding layer 43 is formed of an adhesive, the above-mentioned adhesive composition can be used. The thickness of the bonding layer 43 is preferably 0.1 μm to 50 μm, more preferably 0.1 μm to 10 μm, and still more preferably 0.5 μm to 5 μm.

Hereinafter, the present invention will be described in further detail with examples, but the present invention is not limited by these examples. [Example]

Prepare the front surface plate A1, protective layer B1 to protective layer B4, polarizing plate C1 to polarizing plate C4, touch sensor panel D1, touch sensor panel D2, adhesive sheet E1 to adhesive sheet as shown below E5.

[Front Panel] (Front panel A1) After coating the hard coat composition on the surface of a transparent base film (polyamide imide film, thickness 50 μm), the solvent is dried, and ultraviolet (UV) curing is performed to produce the base film. The front surface plate A1 (thickness 70 μm, tensile modulus of elasticity 6 GPa, length 177 mm × width 105 mm) is formed with a hard coat layer of thickness 10 μm on both surfaces of the material film.

Regarding the composition for the hard coat layer, 30 parts by weight of multifunctional acrylate (MIWON Specialty Chemical, MIRAMER M340) were mixed with a blender, and 50 parts by weight dispersed in propylene glycol monomethyl Nanosilica gel in ether (average particle size 12 nm, solid content 40%), 17 parts by weight of ethyl acetate, 2.7 parts by weight of photopolymerization initiator (Ciba, I184), 0.3 Parts by weight of fluorine-based additives (Shin-Etsu Chemical Industry Co., Ltd., KY1203) are filtered using a polypropylene (PP) filter to produce a hard coat composition.

[Protective layer] (Protective layer B1) As the protective layer B1, a polyethylene terephthalate (PET) film (manufactured by SKC Corporation, trade name: SH34) with a thickness of 23 μm was prepared. The toughness of the PET film was measured by the method described later, and the result was 140 mJ/mm ³ .

(Protective layer B2) As the protective layer B2, a 40 μm-thick Triacetyl Cellulose (TAC) film made by Konica Minolta Co., Ltd., trade name: KC4UAW) was prepared. The toughness of the TAC film was measured by the method described later, and the result was 20 mJ/mm ³ .

(Protective Layer B3) As the protective layer B3, a 60 μm-thick Triacetyl Cellulose (TAC) film made by Konica Minolta Co., Ltd., trade name: KC6UAW) was prepared. The toughness of this TAC film was measured by the method described later, and the result was 18 mJ/mm ³ .

(Protective layer B4) As the protective layer B4, a cyclic olefin resin (Cyclo Olefin Polymer (COP)) film (manufactured by Zeon Corporation, Japan, trade name: ZF-16) with a thickness of 40 μm was prepared. ). The toughness of the COP film was measured by the method described later, and the result was 4 mJ/mm ³ .

(Determination of toughness) According to Japanese Industrial Standards (JIS) K7161, the toughness of the protective layer was measured as follows. Use a super cutter to cut out a rectangular piece of 110 mm long side × 10 mm short side from the protective layer. Next, use the upper and lower clamps of a tensile testing machine [Autograph AG-Xplus tester manufactured by Shimadzu Corporation] to clamp the both ends of the above-mentioned small piece in the longitudinal direction with an interval of 5 cm between the clamps. In an environment with a temperature of 23°C and a relative humidity of 55%, the sheet was stretched in the long-side direction at a stretching speed of 4 mm/min. The toughness is calculated as the integral value of the stress-strain curve from the initial stage to the fracture period.

[Polarizer] (Polarizer C1) The polarizing plate C1 is produced in the following manner. A photo-alignment layer is formed on a Triacetyl Cellulose (TAC) film (thickness 25 μm). A composition containing a dichroic dye and a polymerizable liquid crystal compound is coated on the alignment layer to align and harden the polymerizable liquid crystal compound to obtain a polarizing plate with a thickness of 2 μm. A resin composition containing polyvinyl alcohol and water was coated on the polarizing plate so that the thickness after drying was 1.0 μm. The coating film was dried at a temperature of 80°C for 3 minutes to form an overcoat layer. On the surface of the overcoat layer, the following retardation laminate is bonded via an adhesive layer. The retardation laminate includes: a λ/4 plate (thickness 3 μm) containing a cured layer of a polymerizable liquid crystal compound and an alignment layer/adhesive layer (thickness 5 μm)/ a layer cured by a polymerizable liquid crystal compound, and Positive C layer (thickness 3 μm)/base layer of the alignment layer. In this way, the polarizing plate C1 was produced. The polarizing plate C1 is a circular polarizing plate. The base layer in the retardation layered body corresponds to the base layer 51 shown in FIG. 2 used for forming the second retardation layer (positive C layer), and corresponds to the protective layer 201 shown in FIG. 1. In the polarizing plate C1, the protective layer B1 is used as the base layer 51.

(Polarizer C2～Polarizer C4) As the base material layer 51, the protective layer B2-the protective layer B4 were respectively used instead of the protective layer B1, and the polarizing plate C2-the polarizing plate C4 were produced similarly to the polarizing plate C1.

[Touch sensor panel] (Touch sensor panel D1) A touch sensor with a length of 177 mm × a width of 105 mm is prepared in which a transparent conductive layer, a separation layer, an adhesive layer, and a substrate layer are sequentially laminated Panel D1. The transparent conductive layer contains an ITO layer, and the separation layer contains a cured layer of an acrylic resin composition, and the total thickness of the two is 7 μm. The thickness of the adhesive layer is 2 μm. The substrate layer is a polyethylene terephthalate film with a thickness of 20 μm and a toughness of 69 mJ/mm ³ .

(Touch sensor panel D2) A touch sensor panel D2 with a length of 177 mm and a width of 105 mm is prepared with a transparent conductive layer and a separation layer laminated in this order. The transparent conductive layer contains an ITO layer, and the separation layer contains a hardened layer of an acrylic resin composition, and the total thickness of the two is 7 μm.

[Lamination layer] The adhesive composition forming the bonding layer was prepared in the ratio of each component shown in Table 1. Using an applicator, the adhesive composition was coated on the release-treated surface of the release-treated polyethylene terephthalate film (thickness 38 μm) so that the thickness after drying was 25 μm. The coating layer was dried at 100°C for 1 minute to obtain a film provided with a bonding layer. Then, another polyethylene terephthalate film (thickness 38 μm) that was subjected to a mold release treatment was bonded to the bonding layer. Then, it was cured for 7 days at a temperature of 23° C. and a relative humidity of 50% RH.

[Table 1] Adhesive composition [mass parts] Thickness (μm) Laminated layer Monomers constituting (meth)acrylic resins Crosslinking agent SC agent BA EHA AA 98.4 1 0.6 0.5 0.5 25 BA: Butyl acrylate EHA: 2-ethylhexyl acrylate AA: Acrylic acid crosslinking agent and silane coupling agent The following materials were used. Crosslinking agent: Coronate L (manufactured by Tosoh Co., Ltd.) Silane coupling (SC) agent: KBM-403 (manufactured by Shin-Etsu Chemical Co., Ltd.)

[Adhesive Tablets] (Adhesive sheet E1) (1) Preparation of acrylic polymer 54 parts by mass of n-butyl acrylate, 45 parts by mass of 2-ethylhexyl acrylate, and 1 part by mass of 4-hydroxybutyl acrylate were copolymerized to prepare an acrylic polymer. The weight average molecular weight (Mw) of this acrylic polymer was 800,000.

(2) Preparation of adhesive composition Modified xylylene diisocyanate (manufactured by Soken Chemical Co., Ltd., product name) with 100 parts by mass of the acrylic polymer obtained in the above steps (solid content conversion value; the same below) and trimethylolpropane as a thermal crosslinking agent TD-75") 0.25 parts by mass, and 0.2 parts by mass of 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM403") as a silane coupling agent, mixed, thoroughly stirred, and used The methyl ethyl ketone is diluted to obtain a coating solution of the adhesive composition. Table 2 shows each formulation (solid content conversion value) of the adhesive composition when the acrylic polymer is 100 parts by mass (solid content conversion value). In addition, the codes etc. described in Table 2 indicate the following. BA: n-butyl acrylate 2EHA: 2-ethylhexyl acrylate 4HBA: 4-hydroxybutyl acrylate

(3) Manufacture of adhesive sheet E1 The coating solution of the obtained adhesive composition was coated on the release treatment surface of a light release film (manufactured by LINTEC Corporation, product name "SP-PET752150") with a knife coater. Then, the coating layer was heat-treated at 90°C for 1 minute to form the coating layer. Then, the coating layer on the light release film obtained above and the heavy release film (manufactured by LINTEC, product name "SP-PET382120") were contacted with the coating layer on the release surface of the release film. The adhesive sheet E1 having an adhesive layer with a thickness of 10 μm was produced by curing for 7 days under the conditions of 23°C and 50% RH, that is, a light barrier film/adhesive layer (thickness: 10 μm). )/Adhesive sheet E1 composed of heavy isolation film. Let the adhesive layer of the adhesive sheet E1 be an adhesive layer E1. Table 2 shows the storage elastic coefficient measured for the adhesive sheet E1. In addition, the thickness and storage elasticity coefficient of the adhesive layer E1 are the values measured by the method mentioned later.

(Adhesive sheet E2) Use a coating solution of the same adhesive composition as the adhesive sheet E1, except that only the coating thickness is different, by the same method as the adhesive sheet E1 to produce a light release film/adhesive layer (thickness: 25 μm)/ Adhesive sheet E2 composed of heavy isolation film. Let the adhesive layer of the adhesive sheet E2 be an adhesive layer E2. The adhesive sheet E2 is made of the same adhesive composition as the adhesive sheet E1, so its storage elasticity coefficient is the same value as the adhesive sheet E1.

(Adhesive sheet E3) Use a coating solution of the same adhesive composition as the adhesive sheet E1, except that only the coating thickness is different, by the same method as the adhesive sheet E1 to produce a light release film/adhesive layer (thickness: 50 μm)/ Adhesive sheet E3 composed of heavy isolation film. Let the adhesive layer of the adhesive sheet E3 be an adhesive layer E3. The adhesive sheet E3 is made of the same adhesive composition as the adhesive sheet E1, so its storage elasticity coefficient is the same value as the adhesive sheet E1.

(Adhesive sheet E4) (1) Preparation of acrylic polymer The ratio of each monomer constituting the acrylic polymer was the same as that of the pressure-sensitive adhesive sheet E1, and an acrylic polymer having a weight average molecular weight (Mw) shown in Table 2 was prepared.

(2) Preparation of adhesive composition 100 parts by mass of the acrylic polymer obtained in the above step, and trimethylolpropane as a thermal crosslinking agent modified xylylene diisocyanate (manufactured by Soken Chemical Co., Ltd., product name "TD -75"), and 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Industry Co., Ltd., product name "KBM403") as a silane coupling agent, stir well, and dilute with methyl ethyl ketone. This obtains a coating solution of the adhesive composition.

(3) Manufacture of adhesive sheet E4 Using the obtained coating solution of the adhesive composition, except that only the coating thickness is different, a light release film/adhesive layer (thickness: 5 μm)/heavy release film is produced by the same method as the adhesive sheet E1 Composition of adhesive sheet E4. Let the adhesive layer of the adhesive sheet E4 be an adhesive layer E4. Table 2 shows the storage elastic coefficient measured for the adhesive sheet E4. In addition, the thickness and storage elasticity coefficient of the adhesive layer E4 are the values measured by the method mentioned later.

(Adhesive sheet E5) Use a coating solution of the same adhesive composition as the adhesive sheet E4, except that only the coating thickness is different, by the same method as the adhesive sheet E1 to produce a light release film/adhesive layer (thickness: 10 μm)/ Adhesive sheet E5 composed of heavy isolation film. Let the adhesive layer of the adhesive sheet E5 be an adhesive layer E5. The adhesive sheet E5 is made of the same adhesive composition as the adhesive sheet E4, so its storage elasticity coefficient is the same value as the adhesive sheet E4.

[Table 2] Adhesive sheet Adhesive composition Adhesive layer (Meth) acrylic polymer Thermal crosslinking agent (TD-75) SC agent (KBM403) Thickness (μm) Storage elasticity coefficient (MPa) BA 2EHA 4HBA Weight average molecular weight Mw E1 54 45 1 800 000 0.25 0.2 10 0.09 E2 54 45 1 800 000 0.25 0.2 25 0.09 E3 54 45 1 800 000 0.25 0.2 50 0.09 E4 54 45 1 1.2 million 0.15 0.2 5 0.1 E5 54 45 1 1.2 million 0.15 0.2 10 0.1

(Measurement of the thickness of the adhesive layer) The measurement was performed using a contact-type film thickness measuring device ("MS-5C" manufactured by Nikon Co., Ltd.).

(Measurement of storage elasticity coefficient) The sample laminated so that the adhesive layer is 150 μm is cut into a size of 5 mm × 30 mm, and a rheometer (MCR-301, manufactured by Anton Parr) is used to measure the temperature of 25 °, storage elasticity coefficient at 1% stress and frequency 1 Hz. The measurement results are shown in Table 2.

<Example 1> Corona treatment is performed on the surface of one hard-coat layer side of the front surface plate A1, the two surfaces of the polarizing plate C1, and the transparent conductive layer side of the touch sensor panel D1. Corona treatment was performed under the conditions of frequency: 20 kHz, voltage: 8.6 kV, power: 2.5 kW, and speed: 6 m/min. In addition, each layer is laminated so as to become "front surface plate A1/laminating layer/polarizing plate C1/adhesive layer E1/touch sensor panel D1/adhesive layer E3", and then glued together using a roll bonding machine. The autoclave was cured to obtain the optical layered body of Example 1 having the same configuration as the optical layered body 100 shown in FIG. 1. An impact resistance test and a bending resistance test were performed on the obtained optical laminate. The results are shown in Table 3.

<Example 2 to Example 7, Comparative Example 1, Comparative Example 2> In Example 1, the polarizers, touch sensor panels, and adhesive layers (first adhesive layer, second adhesive layer) shown in Table 3 were used, except for that, the same as Example 1 The optical laminates of Example 2 to Example 7, Comparative Example 1, and Comparative Example 2 were obtained. An impact resistance test and a bending resistance test were performed on the obtained optical laminate. The results are shown in Table 3.

＜impact resistance test＞ A super cutter was used to cut out rectangular small pieces of 150 mm long side × 70 mm short side from the optical laminate obtained in each of the Examples and Comparative Examples, and bonded to the acrylic board via the second adhesive layer of the small piece. In addition, in an environment of 23°C and a relative humidity of 55%, relative to the small piece, hold the evaluation pen with the tip at a height of 10 cm from the outermost surface of the front surface plate of the small piece, and the tip of the pen is downward. The evaluation falls with a pen. Mark the position of the pattern of the transparent conductive layer of the touch sensor panel on the front surface of the small piece, and drop the evaluation pen so that the tip of the pen touches the position where the transparent conductive layer is arranged. As the evaluation pen, a pen with a weight of 11 g and a pen tip diameter of 0.7 mm was used. The small piece after dropping the evaluation pen was visually observed and the function of the touch sensor panel was confirmed, and the evaluation was performed according to the following criteria. Table 3 shows the evaluation results. A: No cracks. Maintain the touch sensor panel function. B: There are cracks. Maintain the touch sensor panel function. C: There are cracks. No touch sensor panel function.

＜Bending resistance test＞ At a temperature of 25°C, perform the bendability test according to the following procedure. In a bending tester (CFT-720C, manufactured by Covotech), the optical laminates obtained in the respective examples and comparative examples were set in a flat state (unbent state), and the following bending operations were performed: The optical laminate is bent so that the distance between the opposing touch sensor panels is 4.0 mm when the touch sensor panel side is inside and the touch sensor panel is bent, and then returns to the original flat state. When this bending operation is performed once, it is calculated as the number of bending once, and the bending operation is repeated. The number of bending times when cracks and/or floating of the adhesive layer occurred in the bending area during the bending operation was confirmed as the limit bending number, and the following evaluation was performed. Table 3 shows the evaluation results. A: Even if the number of bending times reaches 200,000 times, the limit number of bending times is not reached. B: The number of bending reaches the limit when the number of bending is more than 100,000 times and less than 200,000 times, C: The number of bending times is more than 50,000 times and less than 100,000 times, reaching the limit of bending times, D: The number of bending times is less than 50,000 times, reaching the limit of bending times.

[table 3] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Comparative example 1 Comparative example 2 Front panel species A1 A1 A1 A1 A1 A1 A1 A1 A1 Polarizing plate species C1 C1 C2 C2 C3 C1 C1 C4 C4 Protective layer of polarizing plate species B1 B1 B2 B2 B3 B1 B1 B4 B4 Toughness a〔mJ/mm ³ 〕 140 140 20 20 18 140 140 4 4 Thickness b〔μm〕 twenty three twenty three 40 40 60 twenty three twenty three 40 40 First adhesive layer species E1 E2 El E2 E2 E2 E4 E1 E2 Thickness t1〔μm〕 10 25 10 25 25 25 5 10 25 Storage elasticity coefficient G'〔MPa〕 0.09 0.09 0.09 0.09 0.09 0.09 0.1 0.09 0.09 Touch sensor panel species D1 D1 D1 D1 D2 D1 D1 D1 D1 Second adhesive layer species E3 E2 E3 E2 E2 E5 E3 E3 E5 Thickness t2〔μm〕 50 25 50 25 25 10 50 50 10 Storage elasticity coefficient G'〔MPa〕 0.09 0.09 0.09 0.09 0.09 0.1 0.09 0.09 0.1 axb value 3220 3220 800 800 1080 3220 3220 160 160 t1/t2 value 0.2 1 0.2 1 1 2.5 0.1 0.2 2.5 Evaluation Impact resistance test A A B B B A B C C Bending resistance test A B A B B D D B D

10: Front panel 20: Polarizing plate 30: Touch sensor panel 31: Transparent conductive layer 32: Substrate layer 41: The first adhesive layer 42: second adhesive layer 43: Laminated layer 50, 55: Phase difference body 51, 56: substrate layer 52: Orientation layer 53: retardation layer 57: next layer 100: Optical laminate 200: Polarizing layer 201: Protective layer

Fig. 1 is a schematic cross-sectional view showing an example of the optical laminate of the present invention. 2 is a schematic cross-sectional view schematically showing an example of a retarder including a retardation layer as a liquid crystal layer. 3 is a schematic cross-sectional view schematically showing another example of a retarder including a retardation layer as a liquid crystal layer.

10: Front panel

20: Polarizing plate

30: Touch sensor panel

31: Transparent conductive layer

32: Substrate layer

41: The first adhesive layer

42: second adhesive layer

43: Laminated layer

100: Optical laminate

200: Polarizing layer

201: Protective layer

Claims (7)

An optical laminated body, which in turn includes: a front surface plate, a polarizing plate, a first adhesive layer, and a touch sensor panel, and in the optical laminated body, the polarizing plate is on the side of the first adhesive layer The outermost surface of includes a protective layer. Regarding the protective layer, when the toughness is set to a [mJ/mm ³ ] and the thickness is set to b [μm], the relationship of the following formula (1a) is satisfied, a×b ≧700 (1a). The optical laminate according to claim 1, further comprising a second adhesive layer disposed on the side of the touch sensor panel opposite to the side of the first adhesive layer on the surface, When the thickness of the first adhesive layer is set to t1 [μm] and the thickness of the second adhesive layer is set to t2 [μm], the following formula (2a) and the following formula (3a) are satisfied Relationship, t1/t2≧0.1 (2a) t1/t2≦2 (3a). The optical laminate according to claim 1 or 2, wherein the protective layer is provided with a retardation layer on a surface opposite to the first adhesive layer side. The optical laminate according to claim 3, wherein the retardation layer includes a cured product of a polymerizable liquid crystal compound. The optical laminate according to any one of claims 1 to 4, wherein the retardation layer is a positive C layer or a quarter-wavelength layer. The optical laminate according to any one of claims 1 to 5, wherein the touch sensor panel includes a substrate layer and a transparent conductive layer provided on the substrate layer. A display device comprising the optical laminate according to any one of claims 1 to 6.

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