JP6670894B2 - Laminate and image display device - Google Patents

Description

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

In recent years, image display devices equipped with a touch panel and an organic electroluminescence (hereinafter abbreviated as “EL”) display element have been widely used.
Organic EL display elements are known to reduce display quality especially when viewed outdoors, because external light is reflected inside the image display device, and the reflection of external light is suppressed using a circularly polarizing plate. Techniques have been proposed (for example, see Patent Document 1).
In recent years, an organic EL display element having flexibility has been proposed, and a touch panel mounted with the organic EL display element has also been developed in a flexible sheet shape.

On the other hand, as a circularly polarizing plate, a laminate of a linearly polarizing plate and a quarter-wave plate is widely used.
Further, as a linear polarizing plate, a polarizing plate formed by stretching a composite of polyvinyl alcohol and iodine and having both surfaces sandwiched by a pair of protective films is widely used.

JP 2012-32418 A

The present inventors have studied the use of a polarizing plate without a protective film on one side of a polarizer as a linear polarizing plate in a circular polarizing plate from the viewpoint of thinning the device.
As a result of the study, the present inventors have clarified that a polarizing plate in which the protective film on one side of the polarizer is omitted has a problem in that the polarizing plate is curved by temperature or humidity because of low self-supporting property. In particular, the present inventors have found that a laminate obtained by laminating a polarizer and a touch panel (especially a flexible touch panel) from which the protective film on one side of the polarizer has been omitted is bent in the manufacturing process depending on temperature or humidity. And reduced productivity.

  Therefore, an object of the present invention is to provide a laminate of a polarizer and a touch panel, which has a small degree of curvature due to the influence of temperature or humidity, and an image display device including the laminate and an image display element. .

The present inventors have intensively studied to solve the above problems.
First, the present inventors have paid attention to the fact that a polarizing plate from which the protective film on one side of the polarizer is omitted always bends in the stretching direction when it is bent by temperature or humidity.
Here, the stretched film inevitably has anisotropy in internal stress, and also has anisotropy in change in internal stress generated inside the film due to temperature change or humidity change.
Then, when a perturbation of a temperature change or a humidity change is given to the stretched film, the stretched film swells or shrinks in order to eliminate the change in the generated internal stress. Since the change in the internal stress is anisotropic, the degree of swelling or shrinking is also anisotropic.
Here, in the case of a stretched film formed using a polymer as a main material, the main chain of the polymer is generally arranged in the stretching direction, so that the stretched film is considered to swell or shrink significantly in the stretching direction. A commonly used polarizer is a film formed by stretching a composite of polyvinyl alcohol and iodine.
Therefore, the present inventors believe that the fact that the polarizer is formed by stretching is an essential cause of the fact that the polarizing plate is significantly curved by temperature or humidity. It is assumed that the reason for this is that even in a laminate obtained by laminating the touch panel having a touch panel), the temperature or the humidity causes the laminate to bend significantly.
Therefore, if it is possible to develop a laminate of a polarizer and a touch panel having no anisotropy in the change of internal stress due to a change in temperature or humidity, not only can productivity be improved, but also a device that is desired by society. It is thought that it can contribute to thinning.

As described above, since the stretched film has anisotropy in the internal stress change caused by temperature change or humidity change inside the film, the present inventors use the stretched film as a polarizer. Rather, it is conceived that if a polarizer formed by a coating method is laminated on a touch panel, a laminate of a polarizer and a touch panel having a small degree of curvature due to the influence of temperature or humidity can be manufactured, and the present invention is completed. Reached.
That is, it has been found that the above-described object can be achieved by the following configuration.

[1] A laminate having a touch panel and a polarizer laminated on the touch panel and formed by a coating method.
[2] The laminate according to [1], wherein the polarizer is a dye-based polarizer containing at least one type of thermotropic liquid crystalline dichroic dye.
[3] The laminate according to [1] or [2], wherein a touch panel, a polarizer, and an optical film A having in-plane retardation are laminated in this order.
[4] The laminate according to [3], wherein the optical film A satisfies the following formula (I).
120 nm <Re (550) <160 nm ... Formula (I)
Here, in the formula (I), Re (550) represents in-plane retardation at a wavelength of 550 nm.
[5] The laminate according to [3] or [4], wherein the optical film A satisfies the following formula (II).
Re (450) ≦ Re (550) ≦ Re (650) (II)
Here, in the formula (II), Re (450), Re (550) and Re (650) represent in-plane retardations at wavelengths of 450 nm, 550 nm and 650 nm, respectively.
[6] The laminate according to any one of [3] to [5], wherein the optical film A is a film formed by a coating method.
[7] The laminate according to any one of [3] to [6], wherein a touch panel, a polarizer, an optical film A, and an optical film B having a retardation in a thickness direction are laminated in this order. body.
[8] The laminate according to [7], wherein the optical film B satisfies the following formula (III).
-100 nm <Rth (550) <-20 nm Formula (III)
Here, in the formula (III), Rth (550) represents retardation in the thickness direction at a wavelength of 550 nm.
[9] An image display device comprising the laminate according to any one of [1] to [8] and an image display element.
[10] The image display device according to [9], wherein the image display device is an organic EL display device.

  According to the present invention, the present invention provides a laminate of a polarizer and a touch panel, which has a small degree of curvature due to the influence of temperature or humidity, and an image display device including the laminate and an image display element. Can be.

FIG. 1 is a schematic sectional view showing an example of an embodiment of the image display device of the present invention.

Hereinafter, the present invention will be described in detail.
The description of the components described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments.
In addition, in this specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit and an upper limit.
Also, in this specification, a polarizing plate refers to a polarizing plate in which a protective film or a functional layer is disposed on at least one surface of a polarizer, and a polarizing plate and a polarizer are used separately.
Next, terms used in the present specification will be described.

<Letteration>
In this specification, “Re (λ)” and “Rth (λ)” represent an in-plane retardation and a retardation in a thickness direction at a wavelength λ, respectively.
Re (λ) is measured using KOBRA 21ADH or KOBRA WR (both manufactured by Oji Scientific Instruments) by irradiating light having a wavelength of λ nm in the normal direction of the film. In selecting the measurement wavelength λ nm, the measurement can be performed by manually exchanging the wavelength selection filter or converting the measured value by a program or the like.

Here, when the film to be measured is represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method.
Rth (λ) is defined as Re (λ), with the in-plane slow axis (determined by KOBRA 21ADH or KOBRA WR) as the tilt axis (rotation axis) (in the absence of the slow axis, the in-plane film axis). (Any direction is defined as the axis of rotation) With respect to the normal direction of the film, light of wavelength λ nm is incident from the inclined direction in steps of 10 degrees from the normal direction to 50 degrees on one side from each direction, and a total of six points are measured. It is calculated in KOBRA 21ADH or KOBRA WR based on the measured retardation value, the assumed value of the average refractive index, and the input film thickness value.

In the above, in the case of a film having a direction in which the retardation value becomes zero at a certain inclination angle with the in-plane slow axis as a rotation axis from the normal direction, the retardation at an inclination angle larger than the inclination angle The value is calculated in KOBRA 21ADH or KOBRA WR after changing its sign to negative.
In addition, a retardation value is measured from any two inclined directions, with the slow axis as a tilt axis (rotation axis) (when there is no slow axis, an arbitrary direction in the film plane is used as a rotation axis), Rth can also be calculated from the following formulas (1) and (2) based on the value, the assumed value of the average refractive index, and the input film thickness value.

  In the formula, Re (θ) represents a retardation value in a direction inclined by an angle θ from a normal direction. Further, nx represents the refractive index in the direction of the slow axis in the plane, ny represents the refractive index in the direction perpendicular to nx in the plane, and nz represents the refractive index in the direction perpendicular to nx and ny. d represents the thickness of the film.

If the film to be measured cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film having no so-called optical axis (OPTIC AXIS), Rth (λ) is calculated by the following method.
Rth (λ) is obtained by calculating Re (λ) by using an in-plane slow axis (determined by KOBRA 21ADH or KOBRA WR) as an inclination axis (rotation axis) from −50 degrees to +50 degrees with respect to the film normal direction. The light having a wavelength of λ nm is incident from each inclined direction at 10-degree steps, and 11 points are measured. Based on the measured retardation value, the assumed value of the average refractive index, and the input film thickness value, KOBRA 21ADH is measured. Alternatively, it is calculated by KOBRA WR.

  In the above measurement, as the assumed value of the average refractive index, a value from a catalog of various optical films or a polymer handbook (JOHN WILEY & SONS, INC) can be used. If the value of the average refractive index is not known, it can be measured with an Abbe refractometer. Examples of average refractive index values of main optical films are as follows: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59). By inputting these assumed values of the average refractive index and the film thickness, nx, ny and nz are calculated in KOBRA 21ADH or KOBRA WR. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

[Laminate]
The laminate of the present invention is a laminate having a touch panel and a polarizer laminated on the touch panel and formed by a coating method.
Hereinafter, members used for the laminate of the present invention will be described in detail.

[Touch panel]
The touch panel included in the laminate of the present invention is an input device capable of inputting information corresponding to an instruction image by touching the instruction image displayed in an image display area of an image display device with a finger or a touch pen. means.
Examples of the touch panel type include a projection type capacitive type, a surface type capacitive type, a resistive type, and the like, but are not particularly limited in the present invention, and any type of touch panel is suitable. Can be used for

In the present invention, the member on the surface of the touch panel on which a polarizer to be described later is formed is preferably a flexible member having an average transmittance of visible light (400 to 800 nm) of 80% or more, and a polymer film. It can be suitably used.
As the polymer film, specifically, for example, a cellulose acylate film (for example, a cellulose triacetate film, a cellulose diacetate film, a cellulose acetate butyrate film, a cellulose acetate propionate film and the like); a polyolefin such as polyethylene and polypropylene Polyester resin films such as polyethylene terephthalate and polyethylene naphthalate; polyethersulfone films; polyacrylic resin films such as polymethyl methacrylate; polyurethane resin films; polycarbonate films; polysulfone films; polyether films; Pentene film; polyetherketone film; (meth) acrylonitrile film; Imide film; polyamide film; polymer film having an alicyclic structure (for example, norbornene-based resin film such as ARTON (manufactured by JSR)); amorphous polyolefin (for example, cycloolefin polymer such as ZEONEX (manufactured by Nippon Zeon)) ) Film;

(Polarizer)
The polarizer of the laminate of the present invention is not particularly limited as long as it is formed by a coating method among so-called linear polarizers having a function of converting natural light into specific linearly polarized light.
In the present invention, an absorption polarizer and a reflection polarizer can be used, and it is preferable to use an absorption polarizer.

｝ Polarizer material｝
The polarizer is not particularly limited as long as it can be formed by a coating method, and an iodine-based polarizer, a dye-based polarizer using a dichroic dye, a polyene-based polarizer, or the like can be used. Among them, a dye-based polarizer using a dichroic dye is preferably used.
Examples of dichroic dyes include, for example, WO 1997/007184, JP-A-10-095980, JP-A-10-279945, JP-A-11-080735, JP-A-11-172252, and JP-A-2000-239664. JP-A-2008-179670, JP-A-2009-007485, JP-A-2009-0074486, JP-A-2010-155924, JP-A-2011-231245, JP-A-2012-031384, JP-A-2013-139521 Can be used.

In the present invention, it is preferable to use a dye-based polarizer using a thermotropic liquid crystalline dichroic dye from the viewpoint of easily forming a polarizer by a coating method.
The method for producing a dye-based polarizer using a thermotropic liquid crystal dichroic dye is not particularly limited. For example, after forming an alignment film on a support (for example, a touch panel or a temporary support), a thermotropic liquid crystal is formed. It can be prepared by applying a composition containing a dichroic dye, an aligning agent, a leveling agent, other additives and a solvent.

<Thermotropic liquid crystalline dichroic dye>
As the thermotropic liquid crystal dichroic dye, for example, a thermotropic liquid crystal dichroic dye described in JP-A-2011-237513 can be suitably used.

  Specific examples of the thermotropic liquid crystalline dichroic dye are shown below, but the invention is not limited to these compounds.

<Orienting agent>
Examples of the aligning agent include compounds (horizontal aligning agents) represented by general formulas (1) to (3) described in paragraphs [0253] to [0292] of JP-A-2011-237513. , The contents of which are incorporated herein by reference.

<Leveling agent>
As the leveling agent, for example, a coating leveling agent such as a fluorine-based nonionic surfactant, a special acrylic resin-based leveling agent, and a silicone-based leveling agent can be used.

<solvent>
As the solvent, specifically, for example, ketones (eg, acetone, 2-butanone, methyl isobutyl ketone, cyclopentatanone, cyclohexanone, etc.), ethers (eg, dioxane, tetrahydrofuran, etc.), aliphatic hydrocarbons (Eg, hexane), alicyclic hydrocarbons (eg, cyclohexane), aromatic hydrocarbons (eg, toluene, xylene, trimethylbenzene, etc.), and halogenated carbons (eg, dichloromethane, dichloroethane, dichlorobenzene) , Chlorotoluene, etc.), esters (eg, methyl acetate, ethyl acetate, butyl acetate, etc.), water, alcohols (eg, ethanol, isopropanol, butanol, cyclohexanol, etc.), and cellosolves (eg, methyl cellosolve, ethyl cellulose). Solvent), cellosolve acetates, sulfoxides (eg, dimethyl sulfoxide), amides (eg, dimethylformamide, dimethylacetamide, etc.) and the like. These may be used alone, or two or more kinds may be used. You may use together.

<< Method of forming polarizer (coating method) >>
The method of applying a coating solution (hereinafter, also referred to as “polarizer-forming coating solution”) composed of a composition containing the above-described thermotropic liquid crystalline dichroic dye is not particularly limited, and for example, a spin coating method. A well-known method such as a gravure printing method, a flexographic printing method, an ink jet method, a die coating method, a slit die coating method, a cap coating method, and dipping can be performed.

In the present invention, a polarizer formed by coating on a temporary support (hereinafter, also referred to as a “polarizer with a temporary support”) is directly or directly mounted on a touch panel using an adhesive or an adhesive. The touch panel surface may be chemically or physically treated and then bonded.
When a polarizer with a temporary support is attached to the touch panel, the temporary support may be attached to the touch panel, or the polarizer may be attached to the touch panel.
When a polarizer with a temporary support is attached to the touch panel on the polarizer side, the temporary support may be peeled off and removed, or may remain as part of the panel layer configuration. When the temporary support remains as part of the layer structure of the panel, the temporary support may function as an optical film described later or may not function.
When the coating liquid for forming a polarizer is applied on the temporary support, the temporary support is preferably a transparent member having a flexibility in which the average transmittance of visible light (400 to 800 nm) is 80% or more, A polymer film can be suitably used.
As the polymer film, specifically, for example, a cellulose acylate film (for example, a cellulose triacetate film, a cellulose diacetate film, a cellulose acetate butyrate film, a cellulose acetate propionate film and the like); a polyolefin such as polyethylene and polypropylene Polyester resin films such as polyethylene terephthalate and polyethylene naphthalate; polyethersulfone films; polyacrylic resin films such as polymethyl methacrylate; polyurethane resin films; polycarbonate films; polysulfone films; polyether films; Pentene film; polyetherketone film; (meth) acrylonitrile film; Imide film; polyamide film; polymer film having an alicyclic structure (for example, norbornene-based resin film such as ARTON (manufactured by JSR)); amorphous polyolefin (for example, cycloolefin polymer such as ZEONEX (manufactured by Nippon Zeon)) ) Film;

<< Thickness of polarizer >>
The thickness of the polarizer is not particularly limited, and the lower limit is preferably 250 nm or more, more preferably 350 nm or more, and even more preferably 450 nm or more. The upper limit is preferably 50 μm or less, more preferably 30 μm or less, and even more preferably 20 μm or less. When a dye-based polarizer is used, the thickness is preferably 5 μm or less, more preferably 3 μm or less, and still more preferably 1 μm or less.

[Optical film A having in-plane retardation]
The laminate of the present invention is, for the purpose of suppressing external light incident from the touch panel side from being reflected inside the image display device, the above-described touch panel, the above-described polarizer, and the optical film A having in-plane retardation. Are preferably laminated in this order.

The optical film A preferably has a λ / 4 plate function of converting linearly polarized light into circularly polarized light.
Further, the optical film A may have a λ / 4 plate function in a single layer, or may have a λ / 4 plate function in a plurality of layers as a whole. Examples of the combination of a plurality of layers include a combination of a λ / 4 plate and a λ / 2 plate.

In consideration of the case where the polarizer has a retardation and the wavelength dispersion characteristics, the in-plane retardation of the optical film A does not need to be strictly λ / 4, but preferably satisfies the following formula (I).
120 nm <Re (550) <160 nm ... Formula (I)
Here, in the formula (I), Re (550) represents in-plane retardation at a wavelength of 550 nm.

The optical film A preferably satisfies the following formula (II) for the purpose of suppressing a change in the tint of reflected light.
Re (450) ≦ Re (550) ≦ Re (650) (II)
Here, in the formula (II), Re (450), Re (550) and Re (650) represent in-plane retardations at wavelengths of 450 nm, 550 nm and 650 nm, respectively.

In recent years, there has been a strong demand for a thinner image display device, and the optical film A may be made by applying a material having a high refractive index anisotropy from the viewpoint of realizing a thinner device. preferable.
As a material to be applied, a material that spontaneously exhibits optical anisotropy after application is preferable, and a liquid crystal compound can be particularly preferably used. The refractive index anisotropy of the applied material at a wavelength of 550 nm is preferably 0.01 or more, more preferably 0.03 or more, and even more preferably 0.05 or more.
The material to be applied may be applied as it is, or may be dissolved in a solvent and applied in a solution state.
The material to be applied is applied directly or after chemically or physically treating the surface on the surface of the polarizer or on the surface of the optical film B having retardation in the thickness direction described later. You may.
The material to be applied is formed on the temporary support by coating, and then has a retardation on the surface of the polarizer, or a thickness direction described later, using an adhesive or an adhesive. It may be transferred directly onto the surface of the optical film B or after the surface is chemically or physically treated.

  The laminating method when the optical film A has a plurality of layers is not particularly limited. For example, a method of bonding separately prepared layers with an adhesive, a method of directly applying another layer to the previously prepared layer, and the like. Is mentioned.

[Optical film B having retardation in thickness direction]
The laminated body of the present invention, for the purpose of favorably suppressing the reflection of external light from directions other than the normal to the image display element surface, the touch panel described above, the polarizer described above, and the optical film A described above, It is preferable that the optical film B having a retardation in the thickness direction is laminated in this order.

The optical film B preferably further satisfies the following formula (III) for the purpose of better suppressing the reflection of external light from directions other than the normal to the image display element surface.
-100 nm <Rth (550) <-20 nm Formula (III)
Here, in the formula (III), Rth (550) represents retardation in the thickness direction at a wavelength of 550 nm.

The optical film B may have a preferable retardation in a thickness direction in a single layer, or may have a preferable retardation in a thickness direction in a plurality of layers as a whole.
The lamination method when the optical film B has a plurality of layers is not particularly limited. For example, a method of laminating separately prepared layers with an adhesive or directly applying another layer to the previously prepared layer is used. Method and the like.

｝ Material of optical film｝
The material of the optical films A and B is not particularly limited, and may be a polymer film or a layer formed from a liquid crystal compound.
From the viewpoint that the thickness of the optical film can be reduced, it is preferable to use a layer formed from a liquid crystal compound.

<Liquid crystal compound>
The liquid crystal compound is not particularly limited, and various known liquid crystal compounds can be used according to the desired optical characteristics.
The method for forming the layer formed from the liquid crystal compound is not particularly limited. For example, a composition including an alignment film formed on a support and containing a liquid crystal compound, an alignment agent, a leveling agent, other additives, a solvent, and the like. Can be produced by coating. The type of liquid crystal compound in the composition may be one or more.

<Liquid crystal compound for optical film having in-plane retardation>
As the liquid crystal compound that can be used when producing the optical film A having in-plane retardation, any conventionally known liquid crystal compound may be used. For example, a general liquid crystal compound described in JP-A-2008-297210 may be used. Compounds represented by the formula (I) (especially, compounds described in paragraphs 0034 to 0039) and compounds represented by the general formula (1) described in JP-A-2010-84032 (especially, paragraphs 0067 to 0067) 0073) and the like.
Further, particularly in combination with other liquid crystal compounds, azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, A rod-shaped liquid crystal compound selected from alkoxy-substituted phenylpyrimidines, phenyldioxanes, tolanes, and alkenylcyclohexylbenzonitrile may be used.

Particularly preferred examples of the liquid crystal compound that can be used when producing the optical film A having in-plane retardation include a compound represented by the following general formula (II).
L ₁ -G ₁ -D ₁ -Ar-D ₂ -G ₂ -L ₂ General formula (II)
In the formula, D ₁ and D ₂ are each independently -CO-O-, -O-CO-, -C (= S) O-, -OC (= S)-, -CR ¹ R ^{2 -, - CR 1 R 2 -CR} 3 R 4 -, - O-CR 1 R 2 -, - CR 1 R 2 -O -, - CR 1 R 2 -O-CR 3 R 4 -, - CR 1 R ^{2 -O-CO -, - O} -CO-CR 1 R 2 -, - CR 1 R 2 -O-CO-CR 3 R 4 -, - CR 1 R 2 -CO-O-CR 3 R 4 -, —NR ¹ —CR ² R ³ —, —CR ¹ R ² —NR ³ —, —CO—NR ¹ —, or —NR ¹ —CO—, wherein R ¹ , R ² , R ³ , and R ⁴ are Independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, and G ₁ and G ₂ each independently represent a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms. , Methylene contained in the alicyclic hydrocarbon group Groups, -O -, - S -, - N (R 6) - may be substituted by, R ⁶ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, L ₁ and L _2, Each independently represents a monovalent organic group, and at least one selected from the group consisting of L ₁ and L ₂ represents a monovalent group having a polymerizable group, and Ar represents the following general formula (II-1): Represents a divalent aromatic ring group represented by (II-2), (II-3), or (II-4):

In the formulas (II-1) to (II-4), Q ₁ represents —S—, —O—, or NR ¹¹ —, and R ¹¹ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. , Y ₁ represents an aromatic hydrocarbon group having 6 to 12 carbon atoms or an aromatic heterocyclic group having 3 to 12 carbon atoms, and Z ₁ , Z ₂ and Z ₃ each independently represent a hydrogen atom Or an aliphatic hydrocarbon group having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, a halogen atom, a cyano group, a nitro group, —NR ¹² R ¹³ or SR ¹² , wherein Z ₁ and Z ₂ may combine with each other to form an aromatic ring or an aromatic heterocyclic ring, and R ¹² and R ¹³ each independently represent a hydrogen atom or a carbon atom; represents the number 1-6 alkyl group, a ₁ and a ₂ each independently ^{is, -O -, - NR 21 -} (R 21 also represents a hydrogen atom Represents a substituent.), -S- and CO-, and X represents a hydrogen atom or a non-metallic atom of Groups 14 to 16 to which a substituent may be bonded, and Ax represents Represents an organic group having 2 to 30 carbon atoms and having at least one aromatic ring selected from the group consisting of an aromatic hydrocarbon ring and an aromatic heterocyclic ring, and Ay is a hydrogen atom or a carbon atom which may have a substituent. Represents an organic group having 2 to 30 carbon atoms and having at least one aromatic ring selected from the group consisting of an alkyl group of formulas 1 to 6, or an aromatic hydrocarbon ring and an aromatic heterocyclic ring, and having Ax and Ay. The aromatic ring may have a substituent, Ax and Ay may combine to form a ring, and Q ₂ is a hydrogen atom or a carbon atom which may have a substituent. Represents an alkyl group of 1 to 6.

For the definition and the preferred range of each substituent of the compound represented by the general formula (II), D ¹ , D ² , G ¹ , G ² , and L for compound (A) described in JP-A-2012-21068 ¹ , L ² , R ¹ , R ² , R ³ , R ⁴ , X ¹ , Y ¹ , Q ¹ , Q ² are described as D ₁ , D ₂ , G ₁ , G ₂ , L ₁ , L ₂ , respectively. Reference can be made to R ¹ , R ² , R ³ , R ⁴ , X ¹ , and Y ¹ , Z ₁ , Z ₂ ;
JP A ₁ of the compound represented by formula (I) described in 2008-107767 JP, A _2, and the description of X respectively A _1, A _2, and X can refer for, in WO2013 / 018526 Ax of the compound represented by the general formula described (I), Ay, the description with respect to Q ¹ can refer Ax, Ay, for Q _2, respectively. As for Z ₃ , the description of Q ¹ relating to compound (A) described in JP 2012-21068 A can be referred to.

In particular, the organic groups represented by L ₁ and L ₂ are particularly preferably groups represented by -D ₃ -G ₃ -Sp-P ₃ , respectively. D ₃ has the same meaning as D ₁ . G ₃ represents a single bond, a divalent aromatic or heterocyclic group having 6 to 12 carbon atoms, or a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, and the alicyclic hydrocarbon group May be substituted with —O—, —S—, and —NR ⁷ —, wherein R ⁷ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Sp is a single _{bond, - (CH 2) n -} , - (CH 2) n -O -, - (CH 2 -O-) n -, - (CH 2 CH 2 -O-) m, -O- _{(CH 2) n -, -} O- (CH 2) n -O -, - O- (CH 2 -O-) n -, - O- (CH 2 CH 2 -O-) m, -C (= _{O) -O- (CH 2) n} -, - C (= O) -O- (CH 2) n -O -, - C (= O) -O- (CH 2 -O-) n -, - C (= O) -O- (CH 2 CH 2 -O-) m, -C (= O) -N (R 8) - (CH 2) n -, - C (= O) -N (R 8 _{) - (CH 2) n -O} -, - C (= O) -N (R 8) - (CH 2 -O-) n -, - C (= O) -N (R 8) - (CH 2 CH ₂ —O—) represents a spacer group represented by _m . Here, n represents an integer of 2 to 12, m represents an integer of 2 to 6, and R ⁸ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. P ₃ represents a polymerizable group.

The polymerizable group is not particularly limited, but a polymerizable group capable of radical polymerization or cationic polymerization is preferable. As the radical polymerizable group, a generally known radical polymerizable group can be used, and preferable examples thereof include an acryloyl group and a methacryloyl group. In this case, the polymerization rate is generally known that the acryloyl group is fast, acryloyl group is preferred from the viewpoint of productivity improvement, methacryloyl group is also used as a polymerizable group of high birefringence liquid crystal. be able to. As the cationically polymerizable group, generally known cationically polymerizable groups can be used, and specifically, an alicyclic ether group, a cyclic acetal group, a cyclic lactone group, a cyclic thioether group, a spiroorthoester group, a vinyloxy group And the like. Of these, an alicyclic ether group and a vinyloxy group are preferred, and an epoxy group, an oxetanyl group, and a vinyloxy group are particularly preferred.
Examples of particularly preferred polymerizable groups include the following.

In the present specification, the “alkyl group” may be linear, branched, or cyclic. For example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, neopentyl group, 1,1-dimethyl Examples thereof include a propyl group, an n-hexyl group, an isohexyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.
Preferred examples of the compound represented by the general formula (II) are shown below, but are not particularly limited thereto.

<Liquid crystal compound for optical film having retardation in thickness direction>
As the liquid crystal compound that can be used when producing the optical film B having a retardation in the thickness direction, a rod-shaped liquid crystal compound is preferable.
The liquid crystal compound is preferably a liquid crystal compound exhibiting a smectic phase or a nematic phase liquid crystal state, and more preferably a liquid crystal compound exhibiting a nematic phase liquid crystal state.
As the liquid crystalline compound that can be used when producing the optical film B having a retardation in the thickness direction, the liquid crystalline compound that can be used when producing the optical film A having the in-plane retardation described above, Although a similar liquid crystal compound can be used, a compound represented by the following general formula (IA) or a compound represented by the following general formula (IIA) can also be used.

In Formulas (IA) and (IIA), R ^{101 to} R ¹⁰⁴ are each independently — (CH ₂ ) _n —OOC—CH ＝ CH ₂ , and n represents an integer of 2 to 8. X ₁₀₁ and Y ₁₀₁ each independently represent a hydrogen atom or a methyl group.
From the viewpoint of suppressing crystal precipitation, it is preferable that X and Y in formula (IA) or (IIA) represent a methyl group. From the viewpoint of exhibiting properties as a liquid crystal, n is preferably an integer of 4 to 8.

[Image display device]
The image display device of the present invention includes a laminate including the polarizer of the present invention and a touch panel, and an image display element.

FIG. 1 is a schematic sectional view showing an example of an embodiment of the image display device of the present invention.
As shown in FIG. 1, the image display device 10 includes a laminate 3 having a touch panel 1 and a polarizer 2, and an image display element 4.
In the present invention, another member may be provided between each member.

The image display device used in the present invention is not particularly limited, and various known devices such as a liquid crystal display device and an organic EL display device can be used.
Among them, the organic EL display element is preferable because the original reflectance is large and the effect of the present invention is large.

  Hereinafter, the present invention will be specifically described based on examples. Materials, reagents, substance amounts and their ratios, operations, and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the present invention is not limited to the following examples.

[Example 1]
<Production of touch panel 1>
In Example 101 of JP-A-2014-10814, the same as Example 101 except that a commercially available polymethyl methacrylate film having a thickness of 50 μm was used as the transparent substrate (front plate) instead of a glass transparent substrate. A capacitance type input device (hereinafter, referred to as “touch panel 1”) was manufactured by the method described above.

<Surface treatment of touch panel 1: formation of alignment film 1a>
An alignment film 1a was formed on the surface of the touch panel 1 on the polymethyl methacrylate film side using a coating liquid for forming an alignment film 1 having the following composition, and a rubbing treatment was performed on the surface of the alignment film 1a.
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Composition of the coating liquid for forming the alignment film 1 ―――――――――――――――――――――――――――――――
The following modified polyvinyl alcohol 2.4 parts by mass Isopropyl alcohol 1.6 parts by mass Methanol 36 parts by mass Water 60 parts by mass ―――――――――――――――――――――――――― ―――――――

<Preparation of Polarizer 1: Preparation of Laminated Body of Touch Panel 1 and Polarizer 1>
A dye polarizer coating solution 1 having the following composition was prepared.
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Composition of Coating Solution 1 for Dye Polarizer ――――――――――――――――――――――――――――――――
Dichroic dye PB-7 50 parts by mass Dichroic dye C-3 30 parts by mass Dichroic dye C-19 20 parts by mass Fluorine-containing compound C 0.3 part by mass Chloroform 1130 parts by mass ―――――――――――――――――――――――――――

Fluorine-containing compound C

The coating liquid 1 for a dye polarizer was cast on the surface of the rubbed alignment film 1a at 2000 rpm for 10 seconds using a spin coater.
Next, the film was aged for 15 seconds while maintaining the temperature of the coating film at 160 ° C., and then cooled to room temperature to form the polarizer 1 on the touch panel 1. In the formed polarizer 1, the absorption axis was oriented parallel to the rubbing direction.
By the above procedure, a laminate of the touch panel 1 and the polarizer 1 (hereinafter, referred to as “touch panel 1 with polarizer”) was produced.

[Example 2]
<Surface treatment of polarizer 1: formation of alignment film 1b>
An alignment film 1b was formed on the surface of the touch panel with a polarizer 1 manufactured in Example 1 on the surface of the polarizer 1 side using the above-described coating liquid for forming an alignment film 1. Further, a rubbing treatment was performed on the surface of the alignment film 1b in a direction at 45 ° to the rubbing direction performed on the surface of the alignment film 1a.

<Production of A-plate 1: Production of laminate of touch panel 1 with polarizer and A-plate 1>
An A-plate coating solution 1 having the following composition to form an optical film having an in-plane retardation (hereinafter, referred to as “A-plate”) was prepared.
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Composition of coating solution 1 for A-plate ―――――――――――――――――――――――――――――――――
The following reverse-dispersion liquid crystal compound R-3 100 parts by mass A photopolymerization initiator (Irgacure 819, manufactured by BASF Corporation) 3.0 parts by mass The following fluorine-containing compound A 0.8 parts by mass The following crosslinkable polymer O-20 3 parts by mass 588 parts by mass chloroform ――――――――――――――――――――――――――――――――

The coating solution 1 for A plate was applied on the surface of the rubbed alignment film 1b using a bar coater.
Next, after aging for 60 seconds while maintaining the temperature of the coating film at 100 ° C., it was cooled to 70 ° C., and an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 70 mW / cm ² under air was used. The A plate 1 was formed by irradiating 1000 mJ / cm ² ultraviolet rays to fix the alignment state.
According to the above procedure, a laminate (hereinafter, referred to as “the touch panel 1 with a circularly polarizing plate”) in which the A plate 1 was formed on the polarizer 1 side of the touch panel with a polarizer 1 produced in Example 1 was produced.

The measurement of the retardation of the A plate 1 in the touch panel 1 with a circularly polarizing plate was performed as follows.
An alignment film 1b was formed on the surface of the glass substrate and rubbed by the same method except that the touch panel 1 was changed to a commercially available glass substrate. Next, an A-plate 1 was formed on the alignment film 1b using the A-plate coating solution 1 in the same manner as in Example 2.
Using the A plate 1 produced on the surface of the glass substrate as a sample, the retardation of the A plate 1 in the touch panel 1 with a circularly polarizing plate was measured. When the retardation was measured using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments), Re at wavelengths of 450 nm, 550 nm and 650 nm was 108 nm, 130 nm and 137 nm, respectively. Was. Rth at a wavelength of 550 nm was 65 nm.

[Example 3]
<Preparation of temporary support with alignment film 2>
On a surface of a commercially available PET (polyethylene terephthalate) film, an alignment film 2 is formed using a coating solution for forming an alignment film 2 having the following composition to prepare a temporary support with an alignment film 2 using PET as a temporary support. did.
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Composition of the coating liquid for forming the alignment film 2 ―――――――――――――――――――――――――――――――
Polyvinyl alcohol PVA103 (manufactured by Kuraray) 2.4 parts by mass Isopropyl alcohol 1.6 parts by mass Methanol 36 parts by mass Water 60 parts by mass ―――――――――――――――――――― ―――――――――――

<Preparation of C plate 1>
A coating liquid 1 for a C plate having the following composition to form an optical film having a retardation in the thickness direction (hereinafter, referred to as a “C plate”) was prepared.
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Composition of coating solution 1 for C-plate ――――――――――――――――――――――――――――――――
80 parts by mass of the following liquid crystalline compound B01 20 parts by mass of the following liquid crystalline compound B02 1 part by mass of the following vertical aligning agent S01 0.5 part by mass of the following vertical aligning agent S02 0.5 part by mass of ethylene oxide modified trimethylolpropane triacrylate (V # 360, Osaka Organic Chemicals) 8 mass parts Irgacure 907 (manufactured by BASF) 3 mass parts Kayacure DETX (manufactured by Nippon Kayaku Co., Ltd.) 1 mass part Fluorine-containing compound B03 0.4 mass parts Methyl ethyl ketone 170 mass parts Cyclohexanone 30 parts by mass ―――――――――――――――――――――――――――――――――

The coating solution 1 for C plate was applied on the surface of the alignment film 2 of the temporary support with the alignment film 2 prepared above using a bar coater.
Next, the coating film was aged for 60 seconds while maintaining the temperature of the coating film at 60 ° C., and then exposed to air of 1000 mJ / cm ² using an air-cooled metal halide lamp (manufactured by Eye Graphics Co., Ltd.) of 70 mW / cm ² in air. To form a C-plate 1 by fixing the alignment state, thereby preparing a temporary support with the C-plate 1.

<Lamination of C plate 1>
The C plate 1 side of the temporary support with the C plate 1 was bonded to the side of the A plate 1 of the touch panel 1 with a circularly polarizing plate manufactured in Example 2 using an adhesive (SK2057, manufactured by Soken Chemical Co., Ltd.). After bonding, the temporary support was peeled off, and a laminate of the touch panel 1 with a circularly polarizing plate and the C plate 1 (hereinafter, referred to as “touch panel 2 with a circularly polarizing plate”) was produced.

The measurement of the retardation of the C plate 1 in the touch panel 2 with a circularly polarizing plate was performed as follows.
An alignment film 2 was formed on the glass substrate surface in the same manner as in Example 3, except that the surface of the PET film was changed to a commercially available glass substrate surface. Further, in the same manner as in Example 3, the C plate 1 was formed on the surface of the alignment film 2 using the C plate coating liquid 1.
Using the C plate 1 produced on the surface of the glass substrate as a sample, the retardation of the C plate 1 in the touch panel 2 with a circularly polarizing plate was measured. When the phase difference was measured using an automatic birefringence meter (KOBRA-21ADH, manufactured by Oji Scientific Instruments), Re was 0 nm and Rth was −60 nm at a wavelength of 550 nm.

[Comparative Example 1]
<Preparation of polarizing plate 1>
<< Preparation of Polarizer 2 >>
A roll-shaped polyvinyl alcohol film having a thickness of 80 μm was continuously stretched 5 times in the transport direction in an aqueous iodine solution, and dried to obtain a polarizer 2 having a thickness of 20 μm.

｝ Preparation of protective film｝
The surface of a cellulose triacetate film (TD80UL, manufactured by FUJIFILM) was subjected to an alkali saponification treatment to produce a protective film.
In the alkali saponification treatment, first, a cellulose triacetate film is immersed in an aqueous 1.5 N sodium hydroxide solution at 55 ° C. for 2 minutes, and then washed in a water washing bath at room temperature, and 0.1 N sulfuric acid at 30 ° C. is used. And neutralized. Next, it was washed again in a water washing bath at room temperature, and further dried with hot air at 100 ° C.

<< Lamination of polarizer 2 and protective film >>
The alkali saponified surface of the cellulose triacetate film was bonded to one surface of the polarizer 2. For bonding, an aqueous solution of a polyvinyl alcohol-based adhesive was used.
According to the above procedure, the polarizing plate 1 in which the protective film was bonded to one side of the polarizer 2 was produced.

<Production of a laminate of the touch panel 1 and the polarizer 2>
The protective film side of the polarizing plate 1 was bonded to the polymethyl methacrylate film side of the touch panel 1 prepared above using an adhesive (SK2057, manufactured by Soken Chemical Co., Ltd.). According to this procedure, a laminate of the touch panel 1 and the polarizer 2 (hereinafter, referred to as “touch panel 2 with polarizer”) was manufactured.

[Comparative Example 2]
<Surface treatment of polarizer 2>
The surface of the polarizer 2 of the touch panel with polarizer 2 produced in Comparative Example 1 was subjected to a rubbing treatment in a direction at 45 ° to the stretching direction of the polarizer 2.

<Preparation of A plate 1>
On the surface of the rubbed polarizer 2 of the touch panel 2 with a polarizer, the A-plate coating solution 1 was applied in the same manner as in Example 2 to form the A-plate 1.
According to the above procedure, a laminate in which the A plate 1 was formed on the polarizer 2 side of the touch panel 2 with a polarizer (hereinafter, referred to as “the touch panel 3 with a circular polarizer”) was produced.
The touch panel 3 with a circularly polarizing plate was curved during the aging process for forming the A plate 1.

[Comparative Example 3]
<Preparation of C plate 1>
On the side of the A plate 1 of the touch panel 3 with a circularly polarizing plate manufactured in Comparative Example 2, the C plate of the temporary support with the C plate 1 manufactured in Example 3 using an adhesive (SK2057, manufactured by Soken Chemical). One side was bonded. After bonding, the temporary support was peeled off, and a laminate of the touch panel 3 with a circularly polarizing plate and the C plate 1 (hereinafter, referred to as “touch panel 4 with a circularly polarizing plate”) was produced.
Since the touch panel 3 with a circularly polarizing plate was curved, a touch panel 4 with a circularly polarizing plate was also obtained that was curved to the same extent.

[An endurance test]
Durability tests (heat resistance test and moisture resistance test) of the touch panels 1 and 2 with polarizers and the touch panels 1 and 2 with circular polarizers were performed. The results are shown in Table 1 below.
Note that the durability tests were not performed on the touch panels 3 and 4 with circularly polarizing plates manufactured in Comparative Examples 2 and 3 because the touch panels 3 and 4 were already curved at the time of completion of the manufacturing.

<Heat resistance test>
Samples of 5 cm square touch panels 1 and 2 with polarizers and touch panels 1 and 2 with circular polarizers of the same size were placed in an environment at a temperature of 25 ° C. and a volume absolute humidity of 11.5 g / m ³ (50% relative humidity). After being placed for a time, the degree of bending after being placed for 24 hours in an environment at a temperature of 60 ° C. and a volume absolute humidity of 11.7 g / m ³ (9% relative humidity) was measured.
The degree of bending was measured by placing the sample on a horizontal table so that the bending direction was on the upper surface, and measuring the maximum value of the height of the bent portion floating from the horizontal table.
The evaluation criteria were A for less than 1 mm, B for 1 mm or more and less than 5 mm, and C for 5 mm or more.

<Moisture resistance test>
Samples of 5 cm square touch panels 1 and 2 with polarizers and samples of touch panels 1 and 2 with circular polarizers of the same size were placed in an environment at a temperature of 25 ° C. and a volume absolute humidity of 11.5 g / m ³ (50% relative humidity). After being left for a period of time, the degree of bending after being further placed in an environment at a temperature of 25 ° C. and a volume absolute humidity of 2.3 g / m ³ (10% relative humidity) for 24 hours was measured. The measurement of the degree of bending and the evaluation criteria are in accordance with the heat resistance test.

From the results shown in Table 1, the touch panel 1 with a polarizer and the touch panels 1 and 2 with a polarizing plate both have the evaluation results of the heat resistance test and the humidity resistance test of A, and have a small degree of curvature due to the influence of temperature or humidity. (Examples 1 to 3).
On the other hand, the evaluation results of the heat resistance test and the humidity resistance test of the touch panel 2 with a polarizer were both C, indicating that the degree of curvature due to the influence of temperature or humidity was large (Comparative Example 1). Further, since the touch panels 3 and 4 with polarizing plates were curved by 5 mm or more before the endurance test was performed, it is considered that the degree of curvature due to the influence of temperature or humidity was large (Comparative Examples 2 to 3).
From the above results, it was found that the touch panel with a polarizer manufactured by laminating the polarizers produced in the coating step, and the touch panel with a circular polarizer had a smaller degree of curvature due to the influence of temperature or humidity. .

[Mounting on organic EL display element and evaluation of reflected light]
GALAXY S4 manufactured by SAMSUNG equipped with an organic EL display element is disassembled, the circularly polarizing plate used and the touch panel are separated, and the touch panels 1 and 2 with circularly polarizing plates produced in Examples 2 and 3 are pressure-sensitive adhesives. To produce an organic EL image display device. It was confirmed that each of the touch panels with a circularly polarizing plate functions well as an anti-reflection plate.

DESCRIPTION OF SYMBOLS 1 Touch panel 2 Polarizer 3 Laminated body 4 Image display element 10 Image display device

Claims (10)

A touch panel, a polarizer laminated on the touch panel and formed by a coating method, and an optical film A having an in-plane retardation are laminated in this order,
The touch panel has flexibility,
A laminate, wherein the transparent substrate forming the touch panel is a polymer film.   The laminate according to claim 1, wherein the polarizer is a dye-based polarizer including at least one type of thermotropic liquid crystalline dichroic dye. The laminate according to claim 1, wherein an axial relationship between an absorption axis of the polarizer and a slow axis of the optical film A is not parallel or orthogonal. The laminate according to any one of claims 1 to 3, wherein the optical film A satisfies the following formula (I).
120 nm <Re (550) <160 nm ... Formula (I)
Here, in the above formula (I), Re (550) represents in-plane retardation at a wavelength of 550 nm. The laminate according to any one of claims 1 to 4, wherein the optical film A satisfies the following formula (II).
Re (450) ≦ Re (550) ≦ Re (650) (II)
Here, in the formula (II), Re (450), Re (550) and Re (650) represent in-plane retardations at a wavelength of 450 nm, 550 nm and 650 nm, respectively.   The laminate according to any one of claims 1 to 5, wherein the optical film A is a film formed by a coating method.   The laminate according to any one of claims 1 to 6, wherein the touch panel, the polarizer, the optical film A, and the optical film B having a retardation in a thickness direction are laminated in this order. body. The laminate according to claim 7, wherein the optical film B satisfies the following formula (III).
-100 nm <Rth (550) <-20 nm Formula (III)
Here, in the above formula (III), Rth (550) represents retardation in the thickness direction at a wavelength of 550 nm.   An image display device, comprising: the laminate according to claim 1; and an image display element.   The image display device according to claim 9, wherein the image display device is an organic electroluminescence display device.