JP2019215480A - Optical laminate with touch sensor layer, image display device, and method of manufacturing optical laminate - Google Patents

Abstract

To provide an optical laminate with a touch sensor layer, which allows for minimizing change in hue with an angle of polarized sunglasses and preventing misalignment and entrapment of air bubbles when laminating a touch sensor layer.SOLUTION: An optical laminate comprises a touch sensor layer, a first retardation layer, a second retardation layer, a polarizer, and a third retardation layer laminated in the described order from the viewer side, the touch sensor layer and the first retardation layer being stacked together with an adhesive layer in between.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical laminate with a touch sensor layer, an image display device, and a method for manufacturing the optical laminate.

  In order to improve the visibility when viewing the display screen of the image display device with polarized sunglasses, an image display device using a 用 い wavelength plate as a protective base material of the viewing side polarizing plate is known ( Patent Document 1). The image display device of Patent Document 1 has a quarter-wave plate on the viewing side of the viewing-side polarizing plate, and the angle between the absorption axis of the viewing-side polarizing plate and the slow axis of the quarter-wave plate is 45 °. It is said. Thereby, circularly polarized light is emitted from the display screen, and as a result, when the display screen is observed in a state where the transmission axis of the polarized sunglasses is orthogonal to the transmission axis of the viewing side polarizing plate, the display screen becomes dark. Can be resolved.

JP-A-10-10523

  However, in the above-described conventional image display device, there is a problem that when viewing the display screen with polarized sunglasses, a hue change and a transmittance change occur according to the angle of the polarized sunglasses, and visibility is reduced.

  Further, in the production of a touch panel type image display device in which a touch sensor layer is stacked on the viewing side of the viewing side polarizing plate, misalignment or mixing of bubbles may occur when the touch sensor layers are stacked.

  The present invention has been made in order to solve the above-mentioned conventional problems, and its main object is to improve visibility by suppressing a change in hue according to the angle of polarized sunglasses, and to stack a touch sensor layer. An object of the present invention is to provide an optical laminate with a touch sensor layer in which sticking and bubbles are prevented from being mixed at the time, an image display device including the optical laminate, and a method for manufacturing the optical laminate.

The optical laminate of the present invention includes a touch sensor layer, a first retardation layer, a second retardation layer, a polarizer, and a third retardation layer which are laminated in this order from the viewer side. The touch sensor layer and the first retardation layer are laminated via an adhesive layer.
In one embodiment, the in-plane retardation Re1 of the first retardation layer is:
Re1 (450) / Re1 (550) <1.03
Re1 (650) / Re1 (550)> 0.97
The filling,
The in-plane retardation Re2 of the second retardation layer is:
Re2 (450) / Re2 (550) ≧ 1.03
Re2 (650) / Re2 (550) ≦ 0.97
(Where Re1 (450) and Re2 (450) represent in-plane retardation measured with light having a wavelength of 450 nm at 23 ° C., and Re1 (550) and Re2 (550) represent wavelengths of 550 nm at 23 ° C.) , And Re1 (650) and Re2 (650) represent the in-plane retardations measured with light having a wavelength of 650 nm at 23 ° C.).
In one embodiment, the in-plane retardation Re1 (550) of the first retardation layer is 105 nm to 115 nm, and the in-plane retardation Re2 (550) of the second retardation layer is 190 nm to 260 nm. The angle θ1 between the absorption axis of the polarizer and the slow axis of the first retardation layer is 19 ° to 35 °, and the absorption axis of the polarizer and the second retardation layer Whether the angle θ2 with the slow axis is 77 ° to 85 °,
The first retardation layer has an in-plane retardation Re1 (550) of 116 nm to 125 nm, the second retardation layer has an in-plane retardation Re2 (550) of 200 nm to 260 nm, and the polarizer has an in-plane retardation Re2 (550) of 200 nm to 260 nm. An angle θ1 formed between the absorption axis and the slow axis of the first retardation layer is 15 ° to 35 °, and the angle between the absorption axis of the polarizer and the slow axis of the second retardation layer. Whether the angle θ2 is 75 ° to 85 °,
The first retardation layer has an in-plane retardation Re1 (550) of 126 nm to 135 nm, and the second retardation layer has an in-plane retardation Re2 (550) of 210 nm to 260 nm. An angle θ1 formed between the absorption axis and the slow axis of the first retardation layer is 15 ° to 35 °, and the angle between the absorption axis of the polarizer and the slow axis of the second retardation layer. Whether the angle θ2 is 75 ° to 85 °,
Or
The first retardation layer has an in-plane retardation Re1 (550) of 136 nm to 145 nm, and the second retardation layer has an in-plane retardation Re2 (550) of 220 nm to 270 nm. The angle θ1 between the absorption axis and the slow axis of the first retardation layer is 15 ° to 31 °, and the angle between the absorption axis of the polarizer and the slow axis of the second retardation layer is The angle θ2 is 75 ° to 83 °.
In one embodiment, the first retardation layer is composed of a stretched polymer film, and the second retardation layer is composed of an alignment solidified layer of a liquid crystal compound.
In one embodiment, the in-plane retardation Re1 of the first retardation layer is:
Re1 (450) / Re1 (550) <1.03
Re1 (650) / Re1 (550)> 0.97
The filling,
The in-plane retardation Re2 of the second retardation layer is:
Re2 (450) / Re2 (550) <1.03
Re2 (650) / Re2 (550)> 0.97
(Where Re1 (450) and Re2 (450) represent in-plane retardation measured with light having a wavelength of 450 nm at 23 ° C., and Re1 (550) and Re2 (550) represent wavelengths of 550 nm at 23 ° C.) , And Re1 (650) and Re2 (650) represent the in-plane retardations measured with light having a wavelength of 650 nm at 23 ° C.).
In one embodiment, the refractive index ellipsoid of the first retardation layer satisfies the relationship of nx = nz> ny, and the refractive index ellipsoid of the second retardation layer has the relationship of nx> ny = nz. Satisfy the relationship.
In one embodiment, the refractive index ellipsoid of the first retardation layer satisfies the relationship of nx> ny = nz, and the refractive index ellipsoid of the second retardation layer has the relationship of nx = nz> ny. Satisfy the relationship.
According to another aspect of the present invention, an image display device is provided. An image display device of the present invention includes the above optical laminate.
According to still another aspect of the present invention, there is provided a method for producing the optical laminate. The method for producing an optical laminate according to the present invention includes a long first film constituting the first retardation layer, a long second film constituting the second retardation layer, and a long film. A step of producing a polarizing plate with a retardation layer by continuously bonding each of the above-mentioned polarizer and the long third film constituting the third retardation layer to an adjacent film while being transported. And a step of bonding the touch sensor layer to the first film side of the polarizing plate with a retardation layer via an adhesive layer.

  According to the present invention, it is possible to suppress a hue change depending on the angle of the polarized sunglasses when viewing the display screen with the polarized sunglasses, and as a result, the visibility can be improved. Conventionally, when a touch sensor layer is laminated on the surface of an image display panel such as a liquid crystal panel, it is common to use an optical transparent adhesive liquid (LOCA) from the viewpoint of improving contrast and the like. On the other hand, according to the present invention, instead of LOCA, the first retardation layer and the touch sensor layer are laminated using the pressure-sensitive adhesive composition, so that misalignment and trapping of air bubbles can be prevented well. be able to. Furthermore, in the image display panel of the narrow frame design, by laminating the first retardation layer and the touch sensor layer using the adhesive composition, the LOCA overflows from the edge of the panel and runs behind. In addition, it is possible to avoid a decrease in productivity due to an increase in labor for wiping the overflowing LOCA, and as a result, it is possible to contribute to an improvement in productivity.

It is a sectional view of an optical layered product concerning one embodiment of the present invention. It is sectional drawing of the optical laminated body which concerns on another embodiment of this invention. FIG. 4 is a diagram showing hues obtained by transmittance spectrum measurement through the optical laminates of Example 1, Comparative Example 1, and Comparative Example 2. FIG. 9 is a diagram showing a change in transmittance obtained by transmittance spectrum measurement through the optical laminates of Example 1, Comparative Example 1, and Comparative Example 2.

  Hereinafter, although embodiment of this invention is described, this invention is not limited to these embodiment.

(Definition of terms and symbols)
The definitions of terms and symbols in this specification are as follows.
(1) Refractive index (nx, ny, nz)
“Nx” is the refractive index in the direction in which the in-plane refractive index is maximized (ie, the slow axis direction), and “ny” is the direction perpendicular to the slow axis in the plane (ie, the fast axis direction). And “nz” is the refractive index in the thickness direction.
(2) In-plane retardation (Re)
“Re (λ)” is the in-plane retardation measured with light having a wavelength of λ nm at 23 ° C. For example, “Re (550)” is the in-plane retardation measured with light having a wavelength of 550 nm at 23 ° C. Re (λ) is determined by the formula: Re (λ) = (nx−ny) × d, where d (nm) is the thickness of the layer (film).
(3) Phase difference in thickness direction (Rth)
“Rth (λ)” is a retardation in the thickness direction measured with light having a wavelength of λ nm at 23 ° C. For example, “Rth (550)” is a phase difference in the thickness direction measured with light having a wavelength of 550 nm at 23 ° C. Rth (λ) is determined by the formula: Rth (λ) = (nx−nz) × d, where d (nm) is the thickness of the layer (film).
(4) Nz coefficient The Nz coefficient is obtained by Nz = Rth / Re.

A. FIG. 1 is a cross-sectional view of an optical laminate according to one embodiment of the present invention. The optical laminate 10 includes a touch sensor layer 1, a first retardation layer 2, a second retardation layer 3, a polarizer 4, and a third retardation layer 5, which are laminated in this order. Having a configuration. The optical laminate 10 is typically used for an image display device (typically, a liquid crystal display device or an organic EL display device). The optical laminate 10 is disposed on the image display device such that the touch sensor layer 1 is on the viewing side. That is, in a state where the optical laminate 10 is arranged in the image display device, the touch sensor layer 1, the first retardation layer 2, the second retardation layer 3, the polarizer 4, and the third retardation layer 5 Are arranged in this order from the viewing side of the image display device.

  The lamination of each layer is typically performed via any appropriate adhesive layer (for example, an adhesive layer or a pressure-sensitive adhesive layer). Specifically, the touch sensor layer 1 is laminated on the first retardation layer 2 via the adhesive layer 7.

In one embodiment, the first retardation layer 2 shows a flat chromatic dispersion characteristic in which the in-plane retardation value hardly changes regardless of the wavelength of the measurement light, and the second retardation layer 3 The larger the wavelength of the light, the smaller the in-plane retardation value. The in-plane retardation Re1 of the first retardation layer 2 and the in-plane retardation Re2 of the second retardation layer 3 preferably satisfy the following equations (1) to (4).
Re1 (450) / Re1 (550) <1.03 (1)
Re1 (650) / Re1 (550)> 0.97 (2)
Re2 (450) / Re2 (550) ≧ 1.03 (3)
Re2 (650) / Re2 (550) ≦ 0.97 (4)
When the first retardation layer 2 shows a flat wavelength dispersion characteristic and the second retardation layer 3 shows a positive wavelength dispersion characteristic, the in-plane retardation Re1 (550) of the first retardation layer, 2, the in-plane retardation Re2 (550) of the retardation layer, the angle θ1 between the absorption axis of the polarizer and the slow axis of the first retardation layer, and the absorption axis of the polarizer and the second retardation. The angle θ2 between the layer and the slow axis preferably satisfies any of the following (A) to (D).
(A) Re1 (550) is 105 nm to 115 nm, Re2 (550) is 190 nm to 260 nm, θ1 is 19 ° to 35 °, and θ2 is 77 ° to 85 °.
(B) Re1 (550) is 116 nm to 125 nm, Re2 (550) is 200 nm to 260 nm, θ1 is 15 ° to 35 °, and θ2 is 75 ° to 85 °.
(C) Re1 (550) is 126 nm to 135 nm, Re2 (550) is 210 nm to 260 nm, θ1 is 15 ° to 35 °, and θ2 is 75 ° to 85 °.
(D) Re1 (550) is 136 nm to 145 nm, Re2 (550) is 220 nm to 270 nm, θ1 is 15 ° to 31 °, and θ2 is 75 ° to 83 °.

In another embodiment, the first retardation layer 2 has a flat wavelength dispersion characteristic in which the in-plane retardation value hardly changes regardless of the wavelength of the measurement light, and the second retardation layer 3 similarly has And a flat wavelength dispersion characteristic in which the in-plane retardation value hardly changes regardless of the wavelength of the measurement light. The in-plane retardation Re1 of the first retardation layer 2 and the in-plane retardation Re2 of the second retardation layer 3 preferably satisfy the following equations (5) to (8).
Re1 (450) / Re1 (550) <1.03 (5)
Re1 (650) / Re1 (550)> 0.97 (6)
Re2 (450) / Re2 (550) <1.03 (7)
Re2 (650) / Re2 (550)> 0.97 (8)

  Typically, one of the first retardation layer 2 and the second retardation layer 3 satisfies a relationship of nx = nz> ny, and the other refractive index ellipse has a relationship of nx> nx. ny = nz. That is, one of the first retardation layer 2 and the second retardation layer 3 is a negative A plate, and the other is a positive A plate. Typically, the first retardation layer 2 is composed of a stretched body of a polymer film, and the second retardation layer 3 is composed of an alignment solidified layer of a liquid crystal compound. In the third retardation layer 5, the refractive index ellipsoid typically satisfies the relationship of nx> nz> ny. The optical laminated body 10 according to the embodiment of the present invention includes the touch sensor layer 1, the first retardation layer 2, the second retardation layer 3, the polarizer 4, and the third retardation layer 5 from the viewer side. By applying to the image display device so as to be arranged in order, it is possible to suppress the hue change according to the angle of the polarized sunglasses when viewing the display screen with the polarized sunglasses, and as a result, the visibility can be improved. . Note that the description of “ny = nz” in the positive A plate or the description of “nx = nz” in the negative A plate means that the in-plane refractive index (nx or ny) and the refractive index nz in the thickness direction are not necessarily completely. No need to match. For example, if the Nz coefficient is larger than 0.9 and smaller than 1.1, it can be regarded as a positive A plate of ny = nz, and if the Nz coefficient is larger than -0.1 and smaller than 0.1, nx = nz can be considered as a negative A plate.

  The optical laminate 10 may have a surface protective layer such as a cover glass on the opposite side of the touch sensor layer 1 from the first retardation layer 2 for practical use, and the polarizer of the third retardation layer 5 4 may have an adhesive layer on the opposite side. Further, the optical laminate 10 may have a protective layer disposed on one side or both sides of the polarizer 4. Alternatively, the second retardation layer 3 and / or the third retardation layer 5 may also function as a protective layer of the polarizer.

  FIG. 2 is a sectional view of an optical laminate according to another embodiment of the present invention. The optical laminate 11 includes a touch sensor layer 1, a first retardation layer 2, a second retardation layer 3, a polarizer 4, a third retardation layer 5, and a fourth retardation layer. 6 are laminated in this order, and the touch sensor layer 1 is laminated on the first retardation layer 2 via the adhesive layer 7. In the present embodiment, typically, the refractive index ellipsoid of the third retardation layer 5 satisfies the relationship of nx> ny> nz, and the refractive index ellipsoid of the fourth retardation layer 6 is nz> nx> ny.

  The optical laminate may be in the form of a single sheet or may be long.

B. First Retardation Layer The first retardation layer preferably has a flat wavelength dispersion characteristic in which the in-plane retardation value hardly changes regardless of the wavelength of the measurement light, and Re1 (450) / Re1 (550). Is smaller than 1.03, and Re1 (650) / Re1 (550) is larger than 0.97. Re1 (450) / Re1 (550) is more preferably 0.98 to 1.02, and Re1 (650) / Re1 (550) is more preferably 0.98 to 1.02.

  The thickness of the first retardation layer can be set so as to obtain a desired in-plane retardation. Specifically, the thickness is preferably 1 μm to 80 μm, more preferably 10 μm to 60 μm, and most preferably 30 μm to 50 μm.

The first retardation layer preferably has an absolute value of a photoelastic coefficient of 2 × 10 ⁻¹¹ m ² / N or less, more preferably 2.0 × 10 ⁻¹³ m ² / N to 1.5 × 10 ^−11. m ² / N, more preferably from ^{1.0 × 10 -12 m 2 /N~1.2×10 -11} m 2 / N resin. If the absolute value of the photoelastic coefficient is in such a range, a phase difference change is unlikely to occur when contraction stress occurs during heating.

  In one embodiment, the index ellipsoid of the first retardation layer satisfies the relationship of nx> ny = nz, and the Nz coefficient of the first retardation layer is, for example, greater than 0.9 and less than 1.1. is there. In another embodiment, the refractive index ellipsoid of the first retardation layer satisfies the relationship of nx = nz> ny, and the Nz coefficient of the first retardation layer is greater than −0.1 and less than 0.1, for example. is there.

B-1. First retardation layer whose refractive index ellipsoid satisfies the relationship of nx> ny = nz The first retardation layer whose refractive index ellipse satisfies the relationship of nx> ny = nz has the above optical characteristics and It can be composed of any suitable material that can satisfy the mechanical properties. In one embodiment, the first retardation layer can be composed of any appropriate resin film. A typical example of such a resin is a cyclic olefin-based resin.

  The cyclic olefin-based resin is a general term for resins polymerized with a cyclic olefin as a polymerized unit, and is described, for example, in JP-A-1-240517, JP-A-3-14882, JP-A-3-122137, and the like. Resin. Specific examples include a ring-opened (co) polymer of a cyclic olefin, an addition polymer of a cyclic olefin, and a copolymer of a cyclic olefin with an α-olefin such as ethylene or propylene (typically, a random copolymer). And a graft-modified product obtained by modifying these with an unsaturated carboxylic acid or a derivative thereof, and a hydride thereof. Specific examples of the cyclic olefin include a norbornene-based monomer. Examples of the norbornene-based monomer include monomers described in JP-A-2015-210449.

  In the present invention, other ring-opening polymerizable cycloolefins can be used in combination within a range that does not impair the object of the present invention. Specific examples of such cycloolefins include, for example, compounds having one reactive double bond such as cyclopentene, cyclooctene, and 5,6-dihydrodicyclopentadiene.

  The cyclic olefin resin preferably has a number average molecular weight (Mn) of 25,000 to 200,000, more preferably 30,000 to 100, as measured by gel permeation chromatography (GPC) using a toluene solvent. 000, most preferably 40,000-80,000. When the number average molecular weight is in the above range, a material having excellent mechanical strength, good solubility, moldability, and casting operability can be obtained.

  Various products are commercially available as the cyclic olefin-based resin. Specific examples include "ZEONEX" and "ZEONOR", trade names of Zeon Corporation, "Arton", trade name of JSR, "TOPUS", trade name of TICONA, and trade name of Mitsui Chemicals, Inc. "APEL" is mentioned.

  The first retardation layer is obtained, for example, by stretching a film formed from the cyclic olefin-based resin. As a method for forming a film from the cyclic olefin-based resin, any appropriate forming method can be adopted. Since many film products of the cyclic olefin-based resin are commercially available, the commercially available film may be directly subjected to a stretching treatment.

  The film constituting the first retardation layer may be a single-wafer shape or a long shape. In one embodiment, the first retardation layer is produced by cutting out the resin film stretched in the elongate direction at a predetermined angle with respect to the elongate direction. In another embodiment, the first retardation layer is manufactured by continuously and obliquely stretching the long resin film in a direction at a predetermined angle with respect to the long direction. In still another embodiment, the first retardation layer diagonally stretches a laminate of a supporting substrate and a resin layer laminated on the supporting substrate, and forms a diagonally stretched resin layer (resin film). It is produced by transferring to another layer. By adopting the oblique stretching, a long stretched film having an orientation angle of a predetermined angle with respect to the long direction of the film (slow axis in the direction of the angle) can be obtained, for example, with another layer. Can be roll-to-rolled when laminating, and the manufacturing process can be simplified. The predetermined angle may be an angle between the absorption axis (long direction) of the polarizer and the slow axis of the first retardation layer.

  As a stretching machine used for oblique stretching, for example, a tenter-type stretching machine capable of applying a feeding force, a pulling force, or a pulling force at different speeds in the lateral and / or longitudinal directions can be used. The tenter-type stretching machine includes a horizontal uniaxial stretching machine, a simultaneous biaxial stretching machine, and the like. Any appropriate stretching machine can be used as long as a long resin film can be continuously and obliquely stretched.

  By appropriately controlling the left and right speeds in the stretching machine, a first retardation layer having the desired in-plane retardation and having a slow axis in the desired direction can be obtained.

  The stretching temperature of the film may vary depending on the in-plane retardation value and thickness desired for the first retardation layer, the type of resin used, the thickness of the film used, the stretching ratio, and the like. Specifically, the stretching temperature is preferably Tg-30 ° C to Tg + 30 ° C, more preferably Tg-15 ° C to Tg + 15 ° C, and most preferably Tg-10 ° C to Tg + 10 ° C. By stretching at such a temperature, a first retardation layer having an in-plane retardation capable of appropriately exhibiting the effects of the present invention can be obtained. Here, Tg is the glass transition temperature of the constituent material of the film.

B-2. First retardation layer whose refractive index ellipsoid satisfies the relationship of nx = nz> ny The first retardation layer whose refractive index ellipse satisfies the relationship of nx = nz> ny has the above optical characteristics and It can be composed of any suitable material that can satisfy the mechanical properties. In one embodiment, the first retardation layer may be composed of any appropriate resin film whose main component is a thermoplastic resin having a negative intrinsic birefringence value. The thermoplastic resin having negative intrinsic birefringence refers to a resin having a relatively small refractive index in the orientation direction when oriented by stretching or the like. Examples of the thermoplastic resin having a negative intrinsic birefringence include those in which a chemical bond or a functional group having a large polarization anisotropy such as an aromatic or carbonyl group is introduced into a side chain of the polymer. Specifically, an acrylic resin, a styrene resin, a maleimide resin, a fumarate resin, and the like can be given.

  The first retardation layer is obtained, for example, by stretching a resin film containing a thermoplastic resin having a negative intrinsic birefringence value as a main component. Any appropriate stretching method can be adopted as the stretching method. Preferably, a method in which a shrinkable film is bonded to both sides of a resin film containing a thermoplastic resin as a main component and heated and stretched by a longitudinal uniaxial stretching method using a roll stretching machine. The shrinkable film is used for imparting a shrinking force in a direction orthogonal to the stretching direction at the time of heating stretching, and increasing the refractive index (nz) in the thickness direction. The method for bonding the shrinkable film to both surfaces of the resin film is not particularly limited, but an acrylic pressure-sensitive adhesive containing a (meth) acrylic polymer as a base polymer is provided between the resin film and the shrinkable film. A method of providing a layer and bonding is preferred from the viewpoint of excellent workability and economy. The details of the method for forming the resin film constituting the first retardation layer of the present embodiment are described in JP-A-2007-193365. The description of this publication is incorporated herein by reference. In one embodiment, the first retardation layer is manufactured by continuously and obliquely stretching the long resin film in a direction at a predetermined angle with respect to the long direction. In this case, preferably, the resin film obtained by laminating the shrinkable film is laminated on a support substrate, the laminate is obliquely stretched, and the obliquely stretched resin film is transferred to another layer. You.

C. Second retardation layer In one embodiment, the second retardation layer exhibits a positive wavelength dispersion characteristic in which the in-plane retardation value decreases as the wavelength of the measuring light increases, and Re2 (450) / Re2 ( 550) is 1.03 or more, and Re2 (650) / Re2 (550) is 0.97 or less. Re2 (450) / Re2 (550) is more preferably from 1.03 to 1.15, and Re2 (650) / Re2 (550) is more preferably from 0.90 to 0.97. In another embodiment, the second retardation layer has a flat chromatic dispersion characteristic in which the in-plane retardation value hardly changes regardless of the wavelength of the measurement light, and Re2 (450) / Re2 (550) is 1 0.03, and Re2 (650) / Re2 (550) is larger than 0.97. Re2 (450) / Re2 (550) is more preferably 0.98 to 1.02, and Re2 (650) / Re2 (550) is more preferably 0.98 to 1.02.

C-1. Second retardation layer exhibiting positive wavelength dispersion characteristics In the case where the first retardation layer exhibits flat wavelength dispersion characteristics and the second retardation layer exhibits positive wavelength dispersion characteristics, Re1 ( 550), Re2 (550), θ1, and θ2 preferably satisfy any of the following (A) to (D).
(A) Re1 (550) is 105 nm to 115 nm, Re2 (550) is 190 nm to 260 nm, θ1 is 19 ° to 35 °, and θ2 is 77 ° to 85 °.
(B) Re1 (550) is 116 nm to 125 nm, Re2 (550) is 200 nm to 260 nm, θ1 is 15 ° to 35 °, and θ2 is 75 ° to 85 °.
(C) Re1 (550) is 126 nm to 135 nm, Re2 (550) is 210 nm to 260 nm, θ1 is 15 ° to 35 °, and θ2 is 75 ° to 85 °.
(D) Re1 (550) is 136 nm to 145 nm, Re2 (550) is 220 nm to 270 nm, θ1 is 15 ° to 31 °, and θ2 is 75 ° to 83 °.

When the first retardation layer shows a flat wavelength dispersion characteristic and the second retardation layer shows a positive wavelength dispersion characteristic, Re1 (550), Re2 (550), θ1, and θ2 are more preferable. Satisfies any of the following (E) to (G).
(E) Re1 (550) is 105 nm to 115 nm, Re2 (550) is 210 nm to 250 nm, θ1 is 19 ° to 35 °, and θ2 is 77 ° to 85 °.
(F) Re1 (550) is 116 nm to 135 nm, Re2 (550) is 220 nm to 260 nm, θ1 is 19 ° to 31 °, and θ2 is 77 ° to 83 °.
(G) Re1 (550) is 136 nm to 145 nm, Re2 (550) is 220 nm to 260 nm, θ1 is 19 ° to 27 °, and θ2 is 77 ° to 81 °.

When the first retardation layer has a flat wavelength dispersion characteristic and the second retardation layer has a positive wavelength dispersion characteristic, Re1 (550), Re2 (550), θ1, and θ2 are most preferable. Satisfies any of the following (H) to (K).
(H) Re1 (550) is 105 nm to 115 nm, Re2 (550) is 220 nm to 230 nm, θ1 is 23 ° to 27 °, and θ2 is 79 ° to 81 °.
(I) Re1 (550) is 116 nm to 125 nm, Re2 (550) is 220 nm to 250 nm, θ1 is 19 ° to 27 °, and θ2 is 77 ° to 81 °.
(J) Re1 (550) is 126 nm to 135 nm, Re2 (550) is 230 nm to 250 nm, θ1 is 19 ° to 27 °, and θ2 is 77 ° to 81 °.
(K) Re1 (550) is 136 nm to 145 nm, Re2 (550) is 245 nm to 255 nm, θ1 is 19 ° to 23 °, and θ2 is 77 ° to 79 °.

  The thickness of the second retardation layer can be set so as to obtain a desired in-plane retardation. Specifically, the thickness is preferably 1 μm to 80 μm. When the second retardation layer is composed of an alignment solidified layer of a liquid crystal compound, the thickness is more preferably 1 μm to 10 μm, and still more preferably 1 μm to 6 μm.

  In one embodiment, the refractive index ellipsoid of the second retardation layer satisfies the relationship of nx = nz> ny, and the Nz coefficient of the second retardation layer is, for example, greater than −0.1 and less than 0.1. It is. In another embodiment, the refractive index ellipsoid of the second retardation layer satisfies the relationship nx> ny = nz, and the Nz coefficient of the second retardation layer is, for example, greater than 0.9 and less than 1.1. .

C-1-1. Second retardation layer whose refractive index ellipsoid satisfies the relationship of nx> ny = nz The second retardation layer whose refractive index ellipse satisfies the relationship of nx> ny = nz has the above optical characteristics and It can be composed of any suitable material that can satisfy the mechanical properties. In one embodiment, the second retardation layer can be constituted by an alignment solidified layer of a liquid crystal compound. By using a liquid crystal compound, the difference between nx and ny of the obtained retardation layer can be significantly increased as compared with a non-liquid crystal material. Therefore, the thickness of the retardation layer for obtaining a desired in-plane retardation can be obtained. Can be significantly reduced. As a result, it is possible to further reduce the thickness of the optical laminate (finally, the image display device). In this specification, the “solidified alignment layer” refers to a layer in which a liquid crystal compound is aligned in a predetermined direction in the layer and the alignment state is fixed. In the present embodiment, typically, a rod-shaped liquid crystal compound is aligned in a state of being aligned in the slow axis direction of the second retardation layer (homogeneous alignment). Examples of the liquid crystal compound include a liquid crystal compound in which the liquid crystal phase is a nematic phase (nematic liquid crystal). As such a liquid crystal compound, for example, a liquid crystal polymer or a liquid crystal monomer can be used. The mechanism of developing the liquid crystal properties of the liquid crystal compound may be either lyotropic or thermotropic. The liquid crystal polymer and the liquid crystal monomer may be used alone or in combination.

  When the liquid crystal compound is a liquid crystal monomer, the liquid crystal monomer is preferably a polymerizable monomer and a crosslinkable monomer. This is because the alignment state of the liquid crystal monomer can be fixed by polymerizing or crosslinking the liquid crystal monomer. After the liquid crystal monomers are aligned, for example, if the liquid crystal monomers are polymerized or cross-linked, the alignment state can be fixed. Here, a polymer is formed by polymerization, and a three-dimensional network structure is formed by crosslinking, but these are non-liquid crystalline. Therefore, in the formed second retardation layer, for example, a transition to a liquid crystal phase, a glass phase, or a crystal phase due to a temperature change specific to the liquid crystalline compound does not occur. As a result, the second retardation layer becomes a very stable retardation layer that is not affected by temperature changes.

  The temperature range in which the liquid crystal monomer exhibits liquid crystal properties varies depending on the type. Specifically, the temperature range is preferably 40 ° C to 120 ° C, more preferably 50 ° C to 100 ° C, and most preferably 60 ° C to 90 ° C.

  Any appropriate liquid crystal monomer can be employed as the liquid crystal monomer. For example, polymerizable mesogen compounds described in JP-T-2002-533742 (WO 00/37585), EP 358208 (US Pat. No. 5,211,877), EP 66137 (US Pat. No. 4,388,453), WO 93/22397, EP 0261712, DE195504224, DE44040817, GB2280445 and the like can be used. Specific examples of such a polymerizable mesogen compound include, for example, trade name LC242 of BASF, trade name E7 of Merck, and trade name LC-Silicon-CC3767 of Wacker-Chem. As the liquid crystal monomer, for example, a nematic liquid crystal monomer is preferable.

  The alignment solidified layer of the liquid crystal compound is subjected to an alignment treatment on the surface of a predetermined base material, and is coated with a coating liquid containing the liquid crystal compound on the surface to align the liquid crystal compound in a direction corresponding to the alignment treatment. It can be formed by fixing the orientation state. In one embodiment, the substrate is any suitable resin film, and the alignment solidified layer formed on the substrate can be transferred to the surface of the first retardation layer.

  As the alignment treatment, any appropriate alignment treatment can be adopted. Specifically, a mechanical alignment treatment, a physical alignment treatment, and a chemical alignment treatment may be mentioned. Specific examples of the mechanical orientation treatment include a rubbing treatment and a stretching treatment. Specific examples of the physical orientation treatment include a magnetic field orientation treatment and an electric field orientation treatment. Specific examples of the chemical alignment treatment include an oblique deposition method and a photo-alignment treatment. Any appropriate conditions can be adopted as the processing conditions for the various alignment processes depending on the purpose.

  The alignment of the liquid crystal compound is performed by performing treatment at a temperature that indicates a liquid crystal phase according to the type of the liquid crystal compound. By performing such a temperature treatment, the liquid crystal compound assumes a liquid crystal state, and the liquid crystal compound is oriented according to the orientation direction of the substrate surface.

  In one embodiment, the alignment state is fixed by cooling the liquid crystal compound aligned as described above. When the liquid crystal compound is a polymerizable monomer or a crosslinkable monomer, the alignment state is fixed by subjecting the liquid crystal compound aligned as described above to a polymerization treatment or a crosslinking treatment.

  Specific examples of the liquid crystal compound and details of the method for forming the alignment fixed layer are described in JP-A-2006-163343. The description of this publication is incorporated herein by reference.

C-1-2. Second retardation layer whose refractive index ellipsoid satisfies the relationship of nx = nz> ny The second retardation layer whose refractive index ellipse satisfies the relationship of nx = nz> ny has the above-described optical characteristics and It can be composed of any suitable material that can satisfy the mechanical properties.

  In one embodiment, the second retardation layer may be constituted by an alignment solidified layer of a liquid crystal composition containing a discotic liquid crystal compound that is substantially vertically aligned. In the present specification, the "discotic liquid crystal compound" has a disk-shaped mesogen group in a molecular structure, and 2 to 8 side chains are radially formed on the mesogen group by an ether bond or an ester bond. It refers to what is connected. Examples of the mesogen group include, for example, P.I. of Liquid Crystal Dictionary (published by Baifukan). 22, the structure shown in FIG. Specific examples include benzene, triphenylene, truxene, pyran, rufigallol, porphyrin, and metal complexes. Ideally, a substantially vertically aligned discotic liquid crystal compound has an optical axis in one direction in the plane of the film. "Discotic liquid crystal compound oriented substantially vertically" means that the discotic liquid crystal compound has a disc surface perpendicular to the film plane and an optical axis parallel to the film plane. Say.

  The liquid crystalline composition containing the above discotic liquid crystal compound is not particularly limited as long as it contains a discotic liquid crystal compound and exhibits liquid crystallinity. The content of the discotic liquid crystal compound in the liquid crystal composition is preferably from 40 parts by weight to less than 100 parts by weight, more preferably 50 parts by weight, based on 100 parts by weight of the total solid content of the liquid crystal composition. The content is at least 70 parts by weight and less than 100 parts by weight.

  The retardation film comprising an alignment solidified layer of a liquid crystalline composition containing a discotic liquid crystal compound which is substantially vertically aligned can be obtained, for example, by the method described in JP-A-2001-56411. The discotic liquid crystal compound in the above liquid crystal composition can be aligned along a regulating force given by an alignment treatment such as a rubbing treatment or a photo alignment treatment. Therefore, by performing an alignment treatment so that a regulating force acts in a desired direction, and by coating the liquid crystal composition thereon, thereafter, without performing stretching or shrinking treatment, having a slow axis in a desired direction. A roll-shaped retardation film (negative A plate) can be produced. The roll-shaped retardation film having a slow axis in the desired direction can be roll-to-roll when laminated with the polarizer or the first retardation layer.

  In another embodiment, the second retardation layer may be constituted by an alignment solidified layer of a liquid crystalline composition containing a homogeneously aligned lyotropic liquid crystal compound. In the present specification, the “lyotropic liquid crystal compound” refers to a liquid crystal compound in which a liquid crystal phase is developed depending on the concentration of a solute in a solution. Any appropriate lyotropic liquid crystal compound can be used. Specific examples of the lyotropic liquid crystal compound include an amphipathic compound having a hydrophilic group and a hydrophobic group at both ends of the molecule, a chromonic compound having an aromatic ring provided with water solubility, and a cellulose derivative, a polypeptide, And high molecular compounds having a rod-like skeleton in the main chain of nucleic acids and the like. Among these, the retardation film used for the second retardation layer is preferably an alignment-solidified layer of a liquid crystalline composition containing a homogeneously oriented lyotropic liquid crystal compound, wherein the lyotropic liquid crystal compound is soluble in water. Is a chromonic compound having an aromatic ring provided with

  The liquid crystal composition containing the lyotropic liquid crystal compound is not particularly limited as long as it contains a lyotropic liquid crystal compound and exhibits liquid crystallinity. The content of the discotic liquid crystal compound in the liquid crystal composition is preferably 40 parts by weight or more and less than 100 parts by weight, and more preferably 50 parts by weight or more and 100 parts by weight, based on the total solid content of the liquid crystal composition. It is less than 70 parts by weight, most preferably less than 100 parts by weight.

  The retardation film composed of the alignment-solidified layer of the liquid crystalline composition containing the homogeneously aligned lyotropic liquid crystal compound can be obtained, for example, by the method described in JP-A-2002-296415. The lyotropic liquid crystal compound in the above liquid crystal composition can be aligned along a regulating force given by an alignment treatment such as a rubbing treatment or a photo alignment treatment. Therefore, by performing an alignment treatment so that a regulating force acts in a desired direction, and by coating the liquid crystal composition thereon, thereafter, without performing stretching or shrinking treatment, having a slow axis in a desired direction. A roll-shaped retardation film can be produced. The roll-shaped retardation film having a slow axis in the desired direction can be roll-to-roll when laminated with the polarizer or the first retardation layer.

C-2. Second retardation layer showing flat chromatic dispersion characteristics As described above, the second retardation layer has a flat chromatic dispersion characteristic in which the in-plane retardation value hardly changes regardless of the wavelength of the measurement light. It may be a layer.

  The thickness of the second retardation layer can be set so as to obtain a desired in-plane retardation. Specifically, the thickness is preferably 1 μm to 160 μm, more preferably 10 μm to 80 μm, and most preferably 20 μm to 50 μm.

  In one embodiment, the index ellipsoid of the second retardation layer satisfies the relationship nx> ny = nz, and the Nz coefficient of the second retardation layer is greater than 0.9 and less than 1.1, for example. is there. In another embodiment, the index ellipsoid of the second retardation layer satisfies the relationship nx = nz> ny, and the Nz coefficient of the second retardation layer is, for example, greater than −0.1 and less than 0.1. is there.

  The second retardation layer in which the refractive index ellipsoid satisfies the relationship of nx> ny = nz can be made of any appropriate material that can satisfy the above optical and mechanical properties. Examples of the material include the materials described in the above section B-1. The second retardation layer whose index ellipsoid satisfies the relationship of nx = nz> ny can also be made of any appropriate material that can satisfy the above-described optical and mechanical properties. Examples of the material include the materials described in the above section B-2.

D. Polarizer Any appropriate polarizer can be adopted as the polarizer. For example, the resin film forming the polarizer may be a single-layer resin film or a laminate of two or more layers.

  Specific examples of the polarizer composed of a single-layer resin film include hydrophilic polymer films such as a polyvinyl alcohol (PVA) film, a partially formalized PVA film, and an ethylene / vinyl acetate copolymer partially saponified film. And polyene-based oriented films such as those subjected to a dyeing treatment and a stretching treatment with a dichroic substance such as iodine or a dichroic dye, and a dehydration treatment of PVA and a dehydrochlorination treatment of polyvinyl chloride. Preferably, a polarizer obtained by dyeing a PVA-based film with iodine and uniaxially stretching is used because of its excellent optical properties.

  The dyeing with iodine is performed, for example, by immersing a PVA-based film in an aqueous iodine solution. The stretching ratio of the uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after the dyeing treatment or may be performed while dyeing. Moreover, you may dye after extending | stretching. If necessary, the PVA-based film is subjected to a swelling treatment, a crosslinking treatment, a washing treatment, a drying treatment and the like. For example, by immersing the PVA-based film in water and washing it with water before dyeing, not only can the dirt and the antiblocking agent on the surface of the PVA-based film be washed, but also the swelling of the PVA-based film causes uneven dyeing. Can be prevented.

  Specific examples of the polarizer obtained by using the laminate include a laminate of a resin base and a PVA-based resin layer (PVA-based resin film) laminated on the resin base, or a resin base and the resin A polarizer obtained by using a laminate with a PVA-based resin layer applied and formed on a substrate is exemplified. A polarizer obtained by using a laminate of a resin base material and a PVA-based resin layer applied and formed on the resin base material is, for example, a PVA-based resin solution applied to a resin base material and dried to form a resin base material. Forming a PVA-based resin layer thereon to obtain a laminate of a resin base material and a PVA-based resin layer; stretching and dyeing the laminate to form a PVA-based resin layer as a polarizer; obtain. In the present embodiment, the stretching typically includes immersing the laminate in a boric acid aqueous solution and stretching. Further, the stretching may optionally further include stretching the laminate in air at a high temperature (for example, 95 ° C. or higher) before stretching in a boric acid aqueous solution. The obtained resin substrate / polarizer laminate may be used as it is (that is, the resin substrate may be used as a protective layer of the polarizer), and the resin substrate is separated from the resin substrate / polarizer laminate. Then, any appropriate protective layer depending on the purpose may be laminated on the release surface. Details of such a method for producing a polarizer are described in, for example, JP-A-2012-73580. This publication is incorporated herein by reference in its entirety.

  The thickness of the polarizer is preferably 25 μm or less, more preferably 1 μm to 12 μm, and still more preferably 3 μm to 8 μm. When the thickness of the polarizer is within such a range, curling during heating can be favorably suppressed, and good appearance durability during heating can be obtained.

  The polarizer preferably exhibits absorption dichroism at any wavelength from 380 nm to 780 nm. The single transmittance of the polarizer is preferably 42.0% to 46.0%, and more preferably 44.5% to 46.0%. The degree of polarization of the polarizer is preferably 97.0% or more, more preferably 99.0% or more, and further preferably 99.9% or more.

E. FIG. Third retardation layer The thickness of the third retardation layer is preferably from 0.1 µm to 50 µm, more preferably from 10 µm to 30 µm. The third retardation layer preferably doubles as a protective layer of the polarizer. In this case, there is no need to provide a separate protective layer between the polarizer and the third retardation layer. In this case, the third retardation layer is laminated on the polarizer via any appropriate adhesive layer.

  In one embodiment, the refractive index ellipsoid of the third retardation layer satisfies the relationship of nx> nz> ny, and the Nz coefficient of the third retardation layer is, for example, 0.1 to 0.9.

  In another embodiment, the refractive index ellipsoid of the third retardation layer satisfies the relationship nx> ny> nz. The Nz coefficient of the third retardation layer is, for example, 1.1 or more, and is, for example, 20 or less. In this case, the optical laminate has a fourth retardation layer whose refractive index ellipsoid satisfies the relationship of nz> nx> ny.

E-1. Third retardation layer whose refractive index ellipsoid satisfies the relationship of nx>nz> ny The in-plane retardation Re3 (550) of the third retardation layer whose refractive index ellipse satisfies the relationship of nx>nz> ny , 150 nm to 400 nm, and more preferably 180 nm to 350 nm. The angle θ3 between the absorption axis of the polarizer and the slow axis of the third retardation layer is preferably 87 ° to 93 ° or -3 ° to 3 °, more preferably 89 ° to 91 ° or-. 1 ° to 1 °.

  The third retardation layer can be made of any appropriate material that satisfies the above optical and mechanical properties. In one embodiment, it can be composed of any suitable retardation film. Preferably, the retardation film contains at least one thermoplastic resin selected from a norbornene-based resin, a cellulose-based resin, a carbonate-based resin, and an ester-based resin. More preferably, the retardation film contains at least one thermoplastic resin selected from a norbornene-based resin and a carbonate-based resin. This is because it is excellent in heat resistance, transparency, and moldability. Any appropriate method can be adopted as a method for producing the retardation film. Typically, for example, a thermoplastic resin or a composition containing the thermoplastic resin is formed into a sheet to form a polymer film, and a shrinkable film is attached to one or both surfaces of the polymer film, and heated. A method of stretching is exemplified. The heating stretching may be, for example, stretching by heating with a roll stretching machine by a longitudinal uniaxial stretching method.

E-2. Third retardation layer whose refractive index ellipsoid satisfies the relationship of nx>ny> nz The in-plane retardation Re3 (550) of the third retardation layer whose refractive index ellipse satisfies the relationship of nx>ny> nz , 90 nm to 160 nm, and more preferably 110 nm to 155 nm. The angle θ3 between the absorption axis of the polarizer and the slow axis of the third retardation layer is preferably from 87 ° to 93 °, more preferably from 89 ° to 91 °. The third retardation layer can be made of any appropriate material that satisfies the above optical and mechanical properties.

  In one embodiment, the third retardation layer can be composed of any suitable retardation film. The resin forming the retardation film is preferably a norbornene resin or a polycarbonate resin. As a method for producing the retardation film, any appropriate method including a stretching step for a resin film can be adopted. Examples of the stretching method include transverse uniaxial stretching (fixed-end biaxial stretching) and sequential biaxial stretching. The stretching temperature is preferably 135 to 165 ° C, and more preferably 140 to 160 ° C. The stretching ratio is preferably 2.8 to 3.2 times, and more preferably 2.9 to 3.1 times.

  In another embodiment, the third retardation layer can be composed of any suitable non-liquid crystalline material. In this case, the thickness of the third retardation layer is typically 0.1 to 10 μm, more preferably 0.1 to 8 μm, and particularly preferably 0.1 to 5 μm. The non-liquid crystalline material is preferably a non-liquid crystalline polymer, and specifically, a polymer such as polyamide, polyimide, polyester, polyether ketone, polyamide imide, or polyester imide is preferred. One of these polymers may be used alone, or a mixture of two or more thereof may be used. The third retardation layer can be typically formed by applying a solution of the non-liquid crystal polymer to a base film and removing the solvent. In the third method for forming a retardation layer, a process (for example, a stretching process) for imparting optical biaxiality (nx> ny> nz) is preferably performed. By performing such a process, a difference in refractive index (nx> ny) can be reliably provided in the plane. In addition, as a specific example of the above-mentioned polyimide and a specific example of the method of forming the third retardation layer, a polymer and a production method described in JP-A-2006-234848 are exemplified.

F. Fourth retardation layer As described above, the fourth retardation layer has a refractive index characteristic of nz>nx> ny. The in-plane retardation Re4 (550) of the fourth retardation layer is preferably from 10 nm to 150 nm, more preferably from 10 nm to 80 nm. The Nz coefficient of the fourth retardation layer is, for example, -0.1 or less, and preferably -2.0 or less. The angle between the absorption axis of the polarizer and the slow axis of the fourth retardation layer is preferably 87 ° to 93 °, more preferably 89 ° to 91 °.

  The fourth retardation layer can be made of any appropriate material that can satisfy the above optical and mechanical properties. In one embodiment, the fourth retardation layer may be composed of a liquid crystal layer fixed in homeotropic alignment. The liquid crystal material (liquid crystal compound) that can be homeotropically aligned may be a liquid crystal monomer or a liquid crystal polymer. Specific examples of the liquid crystal compound and the method of forming the liquid crystal layer include liquid crystal compounds and formation methods described in [0020] to [0042] of JP-A-2002-333842. In this case, the thickness is preferably 0.1 μm to 6 μm, more preferably 0.2 μm to 3 μm. In another embodiment, the fourth retardation layer may be a retardation film formed of a fumaric acid diester-based resin described in JP-A-2012-32784. In this case, the thickness is preferably 5 μm to 50 μm, more preferably 5 μm to 35 μm.

G. Touch sensor layer As the touch sensor layer, any material that can function as a touch sensor for a touch panel can be used without particular limitation. The touch sensor layer has, for example, a transparent base material layer and a transparent conductive layer disposed on one or both sides thereof.

  The touch sensor layer is preferably a so-called “zero retardation” layer that has no retardation. The in-plane retardation Re (550) of the touch sensor layer is preferably 0 nm to 10 nm, more preferably 0 nm to 5 nm. The thickness direction retardation Rth (550) is preferably from -10 nm to 10 nm, more preferably from -5 nm to 5 nm.

G-1. Transparent base material layer The in-plane retardation Re (550) of the transparent base material layer is preferably 0 nm to 10 nm, more preferably 0 nm to 5 nm. Further, the thickness direction retardation Rth (550) of the transparent base material layer is preferably -10 nm to 10 nm, more preferably -5 nm to 5 nm. Since a resin film having no phase difference or having a small phase difference is unlikely to be thermally shrunk, even when a heat treatment is performed to form a transparent conductive layer (for example, a crystallized ITO layer), the resin film is not heat-shrinkable. Small dimensional change. Therefore, a high quality sheet sensor can be obtained.

  The glass transition temperature of the resin constituting the transparent base material layer is preferably from 50C to 200C, more preferably from 60C to 180C, and further preferably from 70C to 160C. When the glass transition temperature of the resin constituting the transparent base material layer is within such a range, deterioration during formation of the transparent conductive layer can be prevented.

  The resin film may include, for example, cycloolefin resin, polyimide resin, polyvinylidene chloride resin, polyvinyl chloride resin, polyethylene terephthalate resin, polyethylene naphthalate resin, and the like. Preferably, the resin film contains a cycloolefin-based resin and / or a polycarbonate-based resin. By using a cycloolefin-based resin, a transparent substrate layer having high moisture barrier properties can be obtained at low cost. By using a polycarbonate resin, a transparent substrate layer having excellent heat resistance can be obtained.

  As the cycloolefin-based resin, for example, polynorbornene can be preferably used. The polynorbornene refers to a (co) polymer obtained by using a norbornene-based monomer having a norbornene ring as a part or the whole of a starting material (monomer). Various products are commercially available as the polynorbornene. Specific examples include "ZEONEX" and "ZEONOR", trade names of Zeon Corporation, "Arton", trade name of JSR, "TOPUS", trade name of TICONA, and trade name of Mitsui Chemicals, Inc. "APEL" is mentioned.

  The resin film may further include any appropriate additive as needed. Specific examples of additives include plasticizers, heat stabilizers, light stabilizers, lubricants, antioxidants, ultraviolet absorbers, flame retardants, coloring agents, antistatic agents, compatibilizers, crosslinkers, and thickeners. And the like. The type and amount of the additive used can be appropriately set depending on the purpose.

  If necessary, various surface treatments may be performed on the resin film. As the surface treatment, any appropriate method is adopted depending on the purpose. For example, low pressure plasma treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, acid or alkali treatment can be mentioned. In one embodiment, the film surface is made hydrophilic. If the film surface is made hydrophilic, the processability when applying a conductive composition (described later) prepared with an aqueous solvent is excellent. Further, the adhesion between the transparent base material layer and the transparent conductive layer can be improved.

  The thickness of the resin film is preferably less than 75 μm, more preferably 30 μm to 70 μm, and still more preferably 40 μm to 60 μm.

  The total light transmittance of the transparent substrate layer (resin film) is preferably 80% or more, more preferably 85% or more, and further preferably 90% or more.

G-2. Transparent conductive layer The transparent conductive layer can function as an electrode of a touch sensor. The transparent conductive layer may be patterned. As a patterning method, any appropriate method can be adopted depending on the form of the transparent conductive layer. The shape of the pattern of the transparent conductive layer may be any appropriate shape depending on the application. For example, the patterns described in JP-T-2011-511357, JP-A-2010-164938, JP-A-2008-310550, JP-T-2003-511799, and JP-T-2010-541109 are exemplified. After the transparent conductive layer is formed on the transparent substrate, it can be patterned using any appropriate method depending on the form of the transparent conductive layer.

  The surface resistance of the transparent conductive layer is preferably 0.1 Ω / □ to 1000 Ω / □, more preferably 0.5 Ω / □ to 500 Ω / □, and particularly preferably 1 Ω / □ to 250 Ω / □. is there.

  The total light transmittance of the transparent conductive layer is preferably 85% or more, more preferably 90% or more, and further preferably 95% or more.

  In one embodiment, the transparent conductive layer is formed directly on the transparent base material layer. As a specific example of this embodiment, a metal oxide is formed on a transparent base material layer by any appropriate film forming method (for example, a vacuum deposition method, a sputtering method, a CVD method, an ion plating method, a spray method, or the like). A method of forming a layer to obtain a transparent conductive layer. The metal oxide layer may be used as it is as a transparent conductive layer, or may be further heated to crystallize the metal oxide. The temperature at the time of the heating is, for example, 120 ° C to 200 ° C. The transparent conductive layer containing a metal oxide can be patterned by an etching method, a laser method, or the like.

  Examples of the metal oxide include indium oxide, tin oxide, zinc oxide, indium-tin composite oxide, tin-antimony composite oxide, zinc-aluminum composite oxide, and indium-zinc composite oxide. Among them, indium-tin composite oxide (ITO) is preferable.

  The thickness of the transparent conductive layer is preferably 50 nm or less, more preferably 35 nm or less. Within such a range, a transparent conductive layer having excellent light transmittance can be obtained. The lower limit of the thickness of the transparent conductive layer is preferably 1 nm, more preferably 5 nm.

  As another method for directly forming a transparent conductive layer on the transparent substrate layer, for example, a method of applying a composition for forming a transparent conductive layer containing metal nanowires on a transparent substrate layer, a photosensitive method containing a silver salt, A method of forming a metal mesh by applying a conductive composition (a composition for forming a transparent conductive layer) on a transparent base material layer, thereafter performing an exposure treatment and a development treatment, and forming a thin metal wire in a predetermined pattern; A method of applying a composition for forming a transparent conductive layer containing a conductive polymer on a transparent base material layer may be used.

H. Adhesive layer The adhesive layer is typically an adhesive layer or a pressure-sensitive adhesive layer. The adhesive layer is preferably a transparent adhesive layer, and may have a light transmittance at a wavelength of 590 nm (23 ° C.) of, for example, 80% or more, preferably 85% or more, more preferably 90% or more. The average light transmittance of the adhesive layer at a wavelength of 450 nm to 500 nm is preferably 70% or more, more preferably 75% or more, and further preferably 80% or more. The average light transmittance of the adhesive layer at a wavelength of 500 nm to 780 nm is preferably 80% or more, more preferably 85% or more, and further preferably 90% or more.

  Any appropriate adhesive composition can be used as the adhesive composition constituting the adhesive layer. For example, water-based adhesive compositions such as isocyanate-based, polyvinyl alcohol-based, gelatin-based, vinyl-based latex-based, water-based polyurethane, and water-based polyester, curable adhesive compositions such as ultraviolet-curable adhesives and electron beam-curable adhesives And the like. The thickness of the adhesive layer can be, for example, 0.05 μm to 1.5 μm.

  Any appropriate pressure-sensitive adhesive composition can be used as the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer. For example, pressure-sensitive adhesive compositions such as rubber, acrylic, silicone, urethane, vinyl alkyl ether, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, and cellulose can be used. Above all, an acrylic pressure-sensitive adhesive composition is preferably used because it is excellent in optical transparency and excellent in adhesive properties, weather resistance, heat resistance and the like. The thickness of the pressure-sensitive adhesive layer can be, for example, 1 μm to 100 μm.

  The acrylic pressure-sensitive adhesive composition contains, as a base polymer, a partially polymerized monomer component containing an alkyl (meth) acrylate and / or a (meth) acrylic polymer obtained from the monomer component.

  Examples of the alkyl (meth) acrylate include those having a linear or branched alkyl group having 1 to 24 carbon atoms at an ester terminal. Alkyl (meth) acrylates can be used alone or in combination of two or more. In this specification, “(meth) acrylate” means acrylate and / or methacrylate.

  Examples of the alkyl (meth) acrylate include a branched alkyl (meth) acrylate having 4 to 9 carbon atoms. The alkyl (meth) acrylate is preferable because the adhesive properties are easily balanced. Specifically, n-butyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, isobutyl (meth) acrylate, n-pentyl (meth) acrylate, isopentyl (meth) acrylate, isohexyl (Meth) acrylate, isoheptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, and the like. These may be used alone or in combination of two or more. be able to.

  In the present invention, the alkyl (meth) acrylate having an alkyl group having 1 to 24 carbon atoms at the ester terminal is at least 40% by weight based on the total amount of the monofunctional monomer component forming the (meth) acrylic polymer. Is preferably 50% by weight or more, more preferably 60% by weight or more.

  The monomer component includes, as a monofunctional monomer component, a copolymerizable monomer other than the alkyl (meth) acrylate (for example, a carboxyl group-containing monomer, a hydroxyl group-containing monomer, an amide group-containing monomer, an aromatic ring-containing (meth) acrylate, etc.) ) Can be contained. The copolymerizable monomer can be used as the balance of the alkyl (meth) acrylate in the monomer component.

  As the above-mentioned copolymerized monomer and its use amount, the copolymerized monomer and its use amount described in paragraphs 0029 to 0042 of JP-A-2006-157077 or described in paragraphs 0022 to 0036 of JP-A-2006-190996 are described. And the amount used thereof can be applied.

  The monomer component forming the (meth) acrylic polymer may contain a polyfunctional monomer, if necessary, in addition to the monofunctional monomer in order to adjust the cohesive force of the pressure-sensitive adhesive.

  The polyfunctional monomer is a monomer having at least two polymerizable functional groups having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group, and includes, for example, (poly) ethylene glycol di (meth) acrylate, (Poly) propylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1,2-ethylene Glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,12-dodecanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylol methane tri (meth) acryl Ester compounds of polyhydric alcohols such as methacrylate and (meth) acrylic acid; allyl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butyl di (meth) acrylate, hexyl di ( (Meth) acrylate and the like. Among these, trimethylolpropane tri (meth) acrylate, hexanediol di (meth) acrylate, and dipentaerythritol hexa (meth) acrylate can be preferably used. The polyfunctional monomers can be used alone or in combination of two or more.

  The amount of the polyfunctional monomer varies depending on the molecular weight, the number of functional groups, and the like, but is preferably 3 parts by weight or less, more preferably 2 parts by weight or less, based on 100 parts by weight of the total of the monofunctional monomer. 1 part by weight or less is more preferable. The lower limit is not particularly limited, but is preferably 0 part by weight or more, and more preferably 0.001 part by weight or more. When the amount of the polyfunctional monomer used is within the above range, the adhesive strength can be improved.

  The (meth) acrylic polymer can be produced by any appropriate method. For example, radiation polymerization such as solution polymerization and ultraviolet (UV) polymerization, bulk polymerization, and radical polymerization such as emulsion polymerization can be appropriately selected. As the radical polymerization initiator, various known azo-based and peroxide-based initiators can be used. The reaction temperature is usually about 50 to 80 ° C, and the reaction time is 1 to 8 hours. Among the above production methods, a solution polymerization method is preferable, and as a solvent for the (meth) acrylic polymer, ethyl acetate, toluene, and the like are generally used. The solution concentration is usually about 20 to 80% by weight. Further, the obtained (meth) acrylic polymer may be any of a random copolymer, a block copolymer, a graft copolymer and the like.

  The pressure-sensitive adhesive composition can contain a crosslinking agent. Examples of the crosslinking agent include an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, a silicone-based crosslinking agent, an oxazoline-based crosslinking agent, an aziridine-based crosslinking agent, a silane-based crosslinking agent, an alkyletherified melamine-based crosslinking agent, a metal chelate-based crosslinking agent, Oxides and the like. The crosslinking agents may be used alone or in combination of two or more. Among these, an isocyanate-based crosslinking agent is preferably used.

  The mixing ratio of the (meth) acrylic polymer and the crosslinking agent is usually about 0.001 to 20 parts by weight of the crosslinking agent (solids) with respect to 100 parts by weight of the (meth) acrylic polymer (solids). Is preferable, and about 0.01 to 15 parts by weight is more preferable.

  The pressure-sensitive adhesive composition may be, if necessary, an ultraviolet absorber; a rosin derivative resin, a polyterpene resin, a petroleum resin, an oil-soluble phenol resin or other tackifier; a plasticizer; a filler such as a hollow glass balloon; a pigment; Various additives such as an antioxidant; an antioxidant; and a silane coupling agent. The amount of the additive used can be appropriately set depending on the purpose. For example, the amount of the silane coupling agent used is preferably 1 part by weight or less, more preferably 0.01 part by weight or less, based on 100 parts by weight of the monofunctional monomer component forming the (meth) acrylic polymer. 1 part by weight, more preferably 0.02 parts by weight to 0.6 parts by weight.

  The pressure-sensitive adhesive composition is preferably adjusted to a viscosity suitable for a coating operation. Adjustment of the viscosity can be performed by adding a thickening polymer, a polyfunctional monomer, or the like, or by partially polymerizing a monomer component in the pressure-sensitive adhesive composition. The partial polymerization may be performed before the addition of the thickening polymer, the polyfunctional monomer, or the like, or may be performed after the addition. Since the viscosity of the pressure-sensitive adhesive composition can vary depending on the composition of the monomer component, the type and the amount of the additive, etc., it is difficult to uniquely determine a preferable polymerization rate of the partial polymerization, but the polymerization rate is For example, it may be about 20% or less, preferably about 3% to 20%, and more preferably about 5% to 15%. If the degree of polymerization in the partial polymerization exceeds 20%, the viscosity becomes too high, and it becomes difficult to apply the composition to a substrate.

  In one embodiment, an adhesive composition containing a (meth) acrylic polymer and an oligomer type epoxy group-containing silane coupling agent can be preferably used. Such a pressure-sensitive adhesive composition has excellent durability and also has excellent adhesion to a transparent conductive layer, and thus is suitable for bonding the touch sensor layer and the first retardation layer. . Here, the oligomer type refers to a polymer of a monomer dimer or more and less than about 100 monomers, and the weight average molecular weight of the oligomer type silane coupling agent is preferably about 300 to 30,000.

  As the oligomer type epoxy group-containing silane coupling agent, an oligomer type epoxy group-containing silane coupling agent having two or more alkoxysilyl groups in a molecule is preferable. Specific examples include X-41-1053, X-41-1059A, and X-41-1056 manufactured by Shin-Etsu Chemical Co., Ltd. These coupling agents are difficult to volatilize and have a plurality of alkoxysilyl groups, so that they are effective in improving durability and are therefore preferable.

  The amount of the alkoxy group in the oligomer-type epoxy group-containing silane coupling agent is preferably 10 to 60% by weight, more preferably 20 to 50% by weight, and more preferably 20 to 40% by weight in the silane coupling agent. More preferably, it is% by weight.

  Although the type of the alkoxy group is not limited, examples thereof include an alkoxy group having 1 to 6 carbon atoms such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, and hexyloxy. Among these, methoxy and ethoxy are preferred, and methoxy is more preferred. It is also preferable that both methoxy and ethoxy are contained in one molecule.

  The epoxy equivalent of the oligomer type epoxy group-containing silane coupling agent is preferably 1000 g / mol or less, more preferably 500 g / mol or less, and even more preferably 300 g / mol or less. The lower limit of the epoxy equivalent is not particularly limited, but is preferably, for example, 200 g / mol or more.

  The oligomer-type epoxy group-containing silane coupling agent may be used alone or in combination of two or more, but the total content is the same as the (meth) acrylic polymer 100. The amount is preferably 0.01 to 6 parts by weight, more preferably 0.01 to 3 parts by weight, and still more preferably 0.05 to 1 part by weight with respect to parts by weight.

  For details of the pressure-sensitive adhesive composition containing the (meth) acrylic polymer and the oligomer type epoxy group-containing silane coupling agent, reference can be made to JP-A-2006-190996.

  The pressure-sensitive adhesive layer is formed by applying the above-mentioned pressure-sensitive adhesive composition to various substrates and, if necessary, drying and irradiating with radiation. When the pressure-sensitive adhesive layer is formed on a release film, the pressure-sensitive adhesive layer can be transferred from the release film onto a desired member and used.

I. Manufacturing method The manufacturing method of the optical laminated body of the present invention typically includes a long first film constituting the first retardation layer and a long second film constituting the second retardation layer. Each of the film, the long polarizer, and the long third film constituting the third retardation layer is continuously bonded to an adjacent film while being conveyed to form a polarizing plate with a retardation layer. And a step of bonding a touch sensor layer to the first film side of the polarizing plate with a retardation layer via an adhesive layer. There is no limitation on the bonding surface of the touch sensor layer.

  In one embodiment, the second film is formed on a substrate, and the method of manufacturing an optical laminate includes bonding the second film formed on the substrate to the first film, Peeling off. In another embodiment, the polarizer is formed on the base material, and the method for manufacturing an optical laminate includes peeling the base material after attaching the polarizer formed on the base material to the second film. Process. In still another embodiment, the third film is formed on a substrate, and the method for manufacturing an optical laminate includes bonding the third film formed on the substrate to a polarizer, and then bonding the substrate. Including a step of peeling. Note that two or more of the above embodiments may be combined.

J. et al. Image display device The above optical laminate can be applied to an image display device such as a liquid crystal display device. Therefore, the present invention includes an image display device using the above optical laminate. In the image display device according to the embodiment of the present invention, the touch sensor layer, the first retardation layer, the second retardation layer, the polarizer, and the third retardation layer are arranged in this order from the viewing side of the image display device. The optical laminate is provided so as to be arranged.

  Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. In addition, the measuring method of each characteristic is as follows.

(1) Thickness The thickness was measured using a digital micrometer (KC-351C manufactured by Anritsu Corporation).
(2) Retardation value The refractive indices nx, ny and nz of the retardation layers used in the examples and comparative examples were measured by an automatic birefringence measuring device (Oji Scientific Instruments Co., Ltd., automatic birefringence meter KOBRA-WPR). did. The measurement wavelength of the in-plane retardation Re was 450 nm, 550 nm, and 650 nm, the measurement wavelength of the thickness direction retardation Rth was 550 nm, and the measurement temperature was 23 ° C.
(3) Hue change and transmittance change according to the angle of polarized sunglasses A light source (manufactured by Iwasaki Electric Co., Ltd., product name “JCR 12V 50W 20H”) is provided on the back side (third retardation layer side) of the optical laminate. A polarizer simulating polarized sunglasses was disposed on the front side (touch sensor layer side) of the optical laminate. While rotating the polarizer in the range of 90 ° to −90 °, the light emitted from the light source and transmitted through the optical laminate and the polarizer is transmitted through an integrating sphere type high transmittance meter DOT-3C (manufactured by Co., Ltd.). (Murakami Color Research Laboratory). The hues a and b of the Hunter Lab color system were calculated from the spectrum of the obtained transmitted light, and plotted on coordinates where the horizontal axis is a and the vertical axis is b. The horizontal axis is plotted as the angle of the polarizer simulating polarized sunglasses, and the vertical axis is plotted as the transmittance (Y value).

<Example 1>
1. Preparation of Retardation Film A Constituting First Retardation Layer A cycloolefin resin film obtained by hydrogenating a ring-opened polymer of a long norbornene-based monomer (trade name “Zeonor ZF14” manufactured by Zeon Corporation) (Thickness: 55 μm) in the longitudinal direction at a stretching temperature of 145 ° C. and a stretching magnification of 1.5 times to obtain a stretched film having a thickness of 45 μm. Thereafter, the film was stretched in an oblique direction at a stretching ratio of 2.0 times and a stretching temperature of 142 ° C. to produce a retardation film A. This retardation film A has a thickness of 23 μm, an in-plane retardation Re (550) of 110 nm, Re (450) / Re (550) of 1.00, and Re (650) / Re (550). ) Is 1.00, the index ellipsoid satisfies the relationship of nx> nyｎnz (0.9 <Nz coefficient <1.1), and the angle between the slow axis and the elongate direction is 25 °. there were.

2. Preparation of alignment solidification layer B of liquid crystal compound constituting second retardation layer A photo-alignment film is coated on the surface of a long polyethylene terephthalate substrate (PET substrate) having a thickness of 100 μm, and Photo-alignment treatment in a direction of 10 °. On the other hand, 10 parts by weight of a polymerizable discotic liquid crystal compound described in paragraph 0111 of Patent No. 5,186,150 and 3 parts by weight of a photopolymerization initiator for the polymerizable liquid crystal monomer (trade name: Irgacure 907, manufactured by BASF) are mixed with 40 parts by weight of toluene. To prepare a liquid crystal coating solution. The coating liquid was coated on the surface of the PET substrate on which the photo-alignment treatment was performed by using a bar coater, and then heated and dried at 80 ° C. for 4 minutes to align the liquid crystal. By irradiating the liquid crystal layer with ultraviolet rays and curing the liquid crystal layer, a long laminate (alignment-solidification layer laminate) having the alignment-solidification layer B formed on the PET substrate was obtained. The orientation-solidified layer B has a thickness of 2 μm, an in-plane retardation Re (550) of 220 nm, Re (450) / Re (550) of 1.08, and Re (650) / Re (550). ) Was 0.96, the refractive index ellipsoid satisfied the relationship of nx = nz> ny, and the angle between the slow axis and the longitudinal direction was 80 °.

3. Preparation of Polarizer A long amorphous polyethylene terephthalate (A-PET) film (manufactured by Mitsubishi Plastics, trade name “Novaclear”, thickness: 100 μm) was prepared as a base material, and polyvinyl alcohol was applied to one surface of the base material. An aqueous solution of (PVA) resin (trade name “Gohsenol (registered trademark) NH-26” manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) was applied at 60 ° C. and dried to form a 7 μm-thick PVA-based resin layer. The laminate thus obtained was immersed in an insolubilization bath at a liquid temperature of 30 ° C. for 30 seconds (insolubilization step). Next, it was immersed in a dyeing bath at a liquid temperature of 30 ° C. for 60 seconds (dyeing step). Next, it was immersed in a crosslinking bath at a liquid temperature of 30 ° C for 30 seconds (crosslinking step). Thereafter, the laminate was uniaxially stretched in the longitudinal direction (long direction) between rolls having different peripheral speeds while being immersed in a boric acid aqueous solution at a liquid temperature of 60 ° C. The immersion time in the aqueous boric acid solution was 120 seconds, and the laminate was stretched immediately before breaking. Thereafter, the laminate was immersed in a washing bath, and then dried with warm air at 60 ° C. (washing and drying step). Thus, a long laminate (polarizer laminate) in which a polarizer having a thickness of 5 μm was formed on the substrate was obtained.

4. Preparation of Retardation Film C Constituting Third Retardation Layer A polymer film containing an elongated norbornene-based resin having a thickness of 100 μm (a thickness of one side of “ZEONOR ZF-14-100” (trade name, manufactured by Optes Corporation) A 60 μm shrinkable film (trade name “Trefane BO2873” manufactured by Toray Industries, Inc.) was bonded via an acrylic pressure-sensitive adhesive layer (thickness: 15 μm), and then 1.38 times in an air circulation oven at 146 ° C. To obtain a long laminate (retardation film laminate) in which a long retardation film C is formed on a shrinkable film.The retardation film C has a thickness of 17 μm. The in-plane retardation Re (550) is 275 nm, Re (450) / Re (550) is 1.10, Re (650) / Re (550) is 0.95, and the refractive index is Oval Body satisfies a relationship of nx>nz> ny, the angle between the slow axis and the longitudinal direction was 90 °.

5. Production of Touch Sensor Layer A long norbornene-based cycloolefin film (trade name “Zeonor ZF14”, manufactured by Zeon Corporation, thickness: 40 μm) was used as a transparent substrate. The in-plane retardation Re (550) of the norbornene-based cycloolefin film was 1.7 nm, and the retardation Rth (550) in the thickness direction was 1.8 nm.
The norbornene-based cycloolefin film was subjected to corona treatment to make the surface hydrophilic. Thereafter, a metal mesh was formed on the film by a screen printing method using a silver paste (trade name “RA FS 039” manufactured by Toyochem Corporation) (line width: 100 μm, pitch of 1.5 mm), Sintering was performed at 120 ° C. for 10 minutes to form a transparent conductive layer. Thus, a touch sensor layer was obtained. The total light transmittance of the touch sensor layer was 89.3%.

6). Preparation of pressure-sensitive adhesive composition A An acrylic pressure-sensitive adhesive composition A was prepared in the same manner as in Example 1 of JP-A-2006-190996.

7). Production of Optical Laminate The surface of the orientation-fixed layer B of the orientation-fixed layer laminate was bonded to one surface of the retardation film A by roll-to-roll in the longitudinal direction. Next, the PET substrate was peeled off from the orientation-fixed layer laminate, and the surface of the orientation-fixed layer B was bonded to the surface of the polarizer laminate by roll-to-roll in the longitudinal direction. Next, the base material was peeled off from the polarizer laminate, and the retardation film laminate was adhered to the surface of the polarizer in a roll-to-roll manner in the longitudinal direction. Next, the first retardation layer (retardation film A), the second retardation layer (alignment solidified layer B), the polarizer, and the third retardation layer are peeled off from the retardation film laminate. A polarizing plate with a retardation layer was obtained in which a retardation layer (retardation film C) was laminated in this order. An acrylic pressure-sensitive adhesive ("No. 18 *", manufactured by Nitto Denko Corporation) was used for bonding the components. Next, the acrylic pressure-sensitive adhesive composition A was applied to the other surface of the retardation film A so that the thickness after drying was 100 μm, and dried to form a pressure-sensitive adhesive layer. The transparent conductive layer surface of the touch sensor layer was adhered to the surface of the pressure-sensitive adhesive layer in a roll-to-roll manner in a longitudinal direction to obtain an optical laminate. At the time of lamination of the touch sensor layer, no lamination displacement occurred. In addition, when the optical laminated body after the bonding was visually observed, mixing of bubbles in the lamination of the touch sensor layers was not confirmed.

  In the obtained optical laminate, the angle between the absorption axis of the polarizer and the slow axis of the first retardation layer is 25 °, and the absorption axis of the polarizer and the slow axis of the second retardation layer are different. The angle with the axis is 80 °. The obtained optical laminate was subjected to evaluation of hue change and transmittance change according to the angle of polarized sunglasses. FIG. 3 shows the evaluation result of the hue change, and FIG. 4 shows the evaluation result of the transmittance change.

<Comparative Example 1>
1. Production of Retardation Film D A long film composed of polycarbonate resin pellets was obliquely stretched to obtain a long retardation film D. This retardation film D has a thickness of 67 μm, an in-plane retardation Re (550) of 125 nm, Re (450) / Re (550) of 1.06, and Re (650) / Re (550). ) Was 0.97, the refractive index ellipsoid satisfied the relationship of nx> ny = nz, and the angle between the slow axis and the long direction was 45 °.

2. Preparation of Optical Laminate Same as Example 1 except that the retarder film D and the alignment solidified layer B were replaced with the retardation film D and the polarizer surface of the polarizer laminate was bonded by roll-to-roll. Thus, an optical laminated body was produced. The obtained optical laminate is an optical laminate in which the touch sensor layer, the retardation film D, the polarizer, and the retardation film C are laminated in this order, and the absorption axis of the polarizer and the retardation of the retardation film D. The angle made with the phase axis is 45 °. The obtained optical laminate was subjected to evaluation of hue change and transmittance change in the same manner as in Example 1. The results are shown in FIGS. Note that, when the touch sensor layers were bonded, no displacement occurred. In addition, when the obtained optical laminate was visually observed, the inclusion of bubbles in the lamination of the touch sensor layers was not confirmed.

<Comparative Example 2>
1. Production of Retardation Film E In the same manner as in the production of the retardation film A, the in-plane retardation Re (550) is 100 nm, and the angle between the slow axis and the longitudinal direction is 45 °. Got.

2. Preparation of Optical Laminate Same as Example 1 except that the phase difference film E was replaced with the phase difference film E and the polarizer surface of the polarizer laminate was bonded by roll-to-roll instead of the layered product of the alignment fixed layer B. Thus, an optical laminated body was produced. The obtained optical laminate is an optical laminate in which a touch sensor layer, a retardation film E, a polarizer, and a retardation film C are laminated in this order, and the absorption axis of the polarizer and the retardation of the retardation film E The angle with the axis is 45 °. The obtained optical laminate was subjected to evaluation of hue change and transmittance change in the same manner as in Example 1. The results are shown in FIGS. Note that, when the touch sensor layers were bonded, no displacement occurred. In addition, when the obtained optical laminate was visually observed, the inclusion of bubbles in the lamination of the touch sensor layers was not confirmed.

<Comparative Example 3>
In the same manner as in Example 1, a first retardation layer (retardation film A), a second retardation layer (alignment solidified layer B), a polarizer, and a third retardation layer (retardation film C) Was obtained in this order to obtain a polarizing plate with a retardation layer. Next, LOCA (manufactured by Dexerials, product number “SVR1150”) was applied to the other surface of the retardation film A at an application amount of 50 g / m ² . On the coating layer, the touch sensor layer was laminated by roll-to-roll so that the transparent conductive layer face and the coating layer faced each other in the longitudinal direction. Next, UVA (wavelength: 365 nm) was irradiated from the touch sensor layer side at an illuminance of 200 mW / cm ² for 10 seconds to cure the LOCA. In the stacking of the touch sensor layers, a misalignment of about 1 ° occurred. Further, when the obtained optical laminate was visually observed, it was confirmed that about 50 bubbles per 1 m ² were mixed between the touch sensor layer and the first retardation layer.

<Evaluation>
As is clear from FIG. 3, the curve drawn by the hue plot obtained by the spectrum measurement through the optical laminate of Example 1 was obtained by the spectrum measurement through the optical laminate of Comparative Example 1 and Comparative Example 2. In comparison with the curve drawn by the hue plot, the inner area is smaller, or the width of change along the vertical axis is smaller. This means that the light transmitted through the optical laminate of Example 1 has a smaller hue change depending on the angle of the polarized sunglasses than the light transmitted through the optical laminates of Comparative Example 1 and Comparative Example 2. . The amplitude of the curve obtained by the transmittance measurement through the optical laminate of Example 1 is smaller than the amplitude of the curve obtained by the transmittance measurement through the optical laminate of Comparative Example 2. This means that the change in transmittance of the optical laminate of Example 1 due to the change in the angle of the polarizer simulating polarized sunglasses is smaller than that of the optical laminate of Comparative Example 2. In Comparative Example 3 in which the touch sensor layers were laminated using LOCA, misalignment and air bubbles occurred. However, in the embodiment in which the touch sensor layers were laminated via the adhesive layer, misalignment and air bubbles were prevented. Was done. This is presumably because, when the pressure-sensitive adhesive composition was used, the initial adhesion to the adherend was ensured, and no side slippage or accompanying air bubbles occurred during the process transfer.

  The optical laminate of the present invention is suitably used for an image display device (particularly, a liquid crystal display device).

DESCRIPTION OF SYMBOLS 1 Touch sensor layer 2 1st retardation layer 3 2nd retardation layer 4 Polarizer 5 3rd retardation layer 6 4th retardation layer 10 Optical laminated body 11 Optical laminated body

Claims (9)

A touch sensor layer, a first retardation layer, a second retardation layer, a polarizer, and a third retardation layer are stacked in this order from the viewer side,
The touch sensor layer and the first retardation layer are laminated via an adhesive layer,
Optical laminate. The in-plane retardation Re1 of the first retardation layer is:
Re1 (450) / Re1 (550) <1.03
Re1 (650) / Re1 (550)> 0.97
The filling,
The in-plane retardation Re2 of the second retardation layer is:
Re2 (450) / Re2 (550) ≧ 1.03
Re2 (650) / Re2 (550) ≦ 0.97
The optical laminate according to claim 1, which satisfies the following:
Here, Re1 (450) and Re2 (450) represent in-plane retardation measured at 23 ° C. with light having a wavelength of 450 nm, and Re1 (550) and Re2 (550) represent light having a wavelength of 550 nm at 23 ° C. Re1 (650) and Re2 (650) represent in-plane retardations measured at 23 ° C. with light having a wavelength of 650 nm. The in-plane retardation Re1 (550) of the first retardation layer is 105 nm to 115 nm, the in-plane retardation Re2 (550) of the second retardation layer is 190 nm to 260 nm, An angle θ1 formed between the absorption axis and the slow axis of the first retardation layer is 19 ° to 35 °, and the angle between the absorption axis of the polarizer and the slow axis of the second retardation layer. Whether the formed angle θ2 is 77 ° to 85 °,
The first retardation layer has an in-plane retardation Re1 (550) of 116 nm to 125 nm, the second retardation layer has an in-plane retardation Re2 (550) of 200 nm to 260 nm, and the polarizer has an in-plane retardation Re2 (550) of 200 nm to 260 nm. The angle θ1 between the absorption axis and the slow axis of the first retardation layer is 15 ° to 35 °, and the angle between the absorption axis of the polarizer and the slow axis of the second retardation layer is Whether the angle θ2 is 75 ° to 85 °,
The first retardation layer has an in-plane retardation Re1 (550) of 126 nm to 135 nm, and the second retardation layer has an in-plane retardation Re2 (550) of 210 nm to 260 nm. The angle θ1 between the absorption axis and the slow axis of the first retardation layer is 15 ° to 35 °, and the angle between the absorption axis of the polarizer and the slow axis of the second retardation layer is Whether the angle θ2 is 75 ° to 85 °,
Or
The first retardation layer has an in-plane retardation Re1 (550) of 136 nm to 145 nm, the second retardation layer has an in-plane retardation Re2 (550) of 220 nm to 270 nm, and the polarizer has an in-plane retardation Re2 (550) of 220 nm to 270 nm. An angle θ1 formed between the absorption axis and the slow axis of the first retardation layer is 15 ° to 31 °, and the angle between the absorption axis of the polarizer and the slow axis of the second retardation layer. The optical laminated body according to claim 2, wherein the angle θ2 is 75 ° to 83 °.   4. The optical laminate according to claim 1, wherein the first retardation layer is formed of a stretched polymer film, and the second retardation layer is formed of an alignment solidified layer of a liquid crystal compound. 5. body. The in-plane retardation Re1 of the first retardation layer is:
Re1 (450) / Re1 (550) <1.03
Re1 (650) / Re1 (550)> 0.97
The filling,
The in-plane retardation Re2 of the second retardation layer is:
Re2 (450) / Re2 (550) <1.03
Re2 (650) / Re2 (550)> 0.97
The optical laminate according to claim 1, which satisfies the following:
Here, Re1 (450) and Re2 (450) represent in-plane retardation measured at 23 ° C. with light having a wavelength of 450 nm, and Re1 (550) and Re2 (550) represent light having a wavelength of 550 nm at 23 ° C. Re1 (650) and Re2 (650) represent in-plane retardations measured at 23 ° C. with light having a wavelength of 650 nm. The refractive index ellipsoid of the first retardation layer satisfies the relationship of nx = nz> ny,
The optical laminate according to any one of claims 1 to 5, wherein the refractive index ellipsoid of the second retardation layer satisfies a relationship of nx> ny = nz. The refractive index ellipsoid of the first retardation layer satisfies the relationship of nx> ny = nz,
The optical laminate according to any one of claims 1 to 5, wherein the refractive index ellipsoid of the second retardation layer satisfies a relationship of nx = nz> ny.   An image display device comprising the optical laminate according to claim 1. It is a manufacturing method of the optical laminated body in any one of Claims 1-7,
The long first film constituting the first retardation layer, the long second film constituting the second retardation layer, the long polarizer, and the third position. A step of producing a polarizing plate with a retardation layer by continuously bonding each of the long third films constituting the retardation layer to an adjacent film while transporting the film, and A method for producing an optical laminate, comprising a step of attaching the touch sensor layer to a first film side via an adhesive layer.