WO2021106744A1 - Optical laminate and image displaying device - Google Patents

Abstract

The present invention can realize a display screen capable of exhibiting an appearance in harmony with the design of a peripheral part thereof during non-displaying and clearly displaying an image by an image display device during displaying. The present invention provides an optical laminate having, sequentially from a viewing side, a light diffusion layer, a light transmissive reflection plate, and an absorption-type polarizer.

Description

Optical laminate and image display device

The present invention relates to an optical laminate and an image display device including the optical laminate.

In recent years, electrical appliances and in-vehicle equipment have become more sophisticated, and the mounting area of display screens such as operation screens and monitor screens tends to increase. Since the display screen is usually observed in black when it is not displayed, it may not be compatible with the design of the peripheral portion of the housing or the like, and the overall design may be deteriorated.

As a method of making it difficult to recognize the difference between the appearance of the display screen and the design of the peripheral portion and thereby improving the design as a whole, Patent Documents 1 and 2 can harmonize the display screen with the peripheral portion. It is proposed to cover it with a decorative sheet. However, with the techniques of Patent Documents 1 and 2, it is difficult to realize a display screen that exhibits an appearance in harmony with the design of the peripheral portion when not displayed and can clearly display an image by an image display device when displayed. is there.

Japanese Unexamined Patent Publication No. 2018-128581 JP-A-2019-120833

The present invention has been made to solve the above-mentioned conventional problems, and its main purpose is to exhibit an appearance in harmony with the design of the peripheral portion when not displayed, and to clarify an image by an image display device when displayed. The purpose is to realize a display screen that can be displayed on.

According to one aspect of the present invention, there is provided an optical laminate having a light diffusing layer, a light transmitting reflector, and an absorption type polarizer in this order from the viewing side.
In one embodiment, the optical laminate has a light-transmitting colored layer on the visual side of the light-transmitting reflector.
In one embodiment, the optical laminate has the light diffusing layer on the outermost surface, and the haze of the light diffusing layer is 5% or more.
In one embodiment, the optical laminate has a protective layer on the outermost surface, and the haze of the light diffusion layer is 5% or more.
In one embodiment, the single transmittance of the light transmissive reflector is 10% to 70%.
In one embodiment, the light transmissive reflector comprises a reflective polarizer.
In one embodiment, the reflection axis direction of the reflection type polarizer and the absorption axis direction of the absorption type polarizer are arranged so as to be substantially parallel to each other.
According to another aspect of the present invention, there is provided an image display device including the above optical laminate.

According to the optical laminate of the present invention, it is possible to realize a display screen that exhibits an appearance in harmony with the design of the peripheral portion when not displayed and can clearly display an image by the image display device when displayed. More specifically, since the optical laminate of the present invention has a light diffusion layer on the visual side of the light transmissive reflector, it is possible to diffusely reflect incident light (external light) and suppress glossiness. As a result, it is possible to exhibit a metallic opaque luster and harmonize the texture with the peripheral portion of the housing or the like.

It is the schematic sectional drawing of the optical laminated body by one Embodiment of this invention. It is the schematic sectional drawing of the optical laminated body by one Embodiment of this invention. It is a schematic perspective view of an example of a reflective polarizer that can be used in the present invention. It is the schematic sectional drawing of the optical laminated body by one Embodiment of this invention. It is the schematic sectional drawing of the optical laminated body by one Embodiment of this invention. It is the schematic sectional drawing of the optical laminated body by one Embodiment of this invention. It is the schematic sectional drawing of the image display device by one Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

A. Definition of terms (1) The expression "substantially orthogonal" includes the case where the angle between the two directions is 90 ° ± 10 °, preferably 90 ° ± 7 °, and more preferably 90 °. It is ± 5 °. Further, the term "orthogonal" in the present specification may include a substantially orthogonal state.
(2) The expression "substantially parallel" includes the case where the angle formed by the two directions is 0 ° ± 10 °, preferably 0 ° ± 7 °, and more preferably 0 ° ± 5 °. Is. Further, the term "parallel" in the present specification may include a substantially parallel state.
(3) The terms "layer", "board", "sheet" and "film" are not distinguished from each other based solely on the difference in designation. For example, the term "layer" is a concept that includes members that can be called "plates", "sheets", "films".

B. Optical laminate B-1. Overall Configuration of Optical Laminates FIG. 1 is a schematic cross-sectional view of an optical laminate according to one embodiment of the present invention. The optical laminate 100a has a light diffusing layer 10, a light transmitting reflector 20, and an absorbing polarizing element 30 in this order from the viewing side. The optical laminate 100a is typically applied to an image display device having an optical cell such as a liquid crystal display device having a liquid crystal cell and an organic EL display device having an organic electroluminescence (EL) cell. At this time, the light transmissive reflector 20 is arranged on the visible side of the optical cell so as to be on the visible side of the absorption type polarizer 30. By arranging in this way, when the image display device is hidden, the incident light (external light) can be diffusely reflected to suppress the glossiness, and as a result, the display screen has a metallic opaque gloss (silver metallic). ), And it can be harmonized with the texture of the peripheral part such as the housing. Further, at the time of display, the image by the image display device can be clearly visually recognized by observing the light emitted from the optical cell side and transmitted through the absorption type polarizer 30.

FIG. 2 is a schematic cross-sectional view of an optical laminate according to another embodiment of the present invention. The optical laminate 100b has a light diffusing layer 10, a light transmitting colored layer 40, a light transmitting reflector 20, and an absorbing polarizing element 30 in this order from the visual side. The optical laminate 100b is typically applied to an image display device provided with an optical cell like the optical laminate 100a, in which case the light transmissive reflector 20 is on the visual side of the absorption type polarizer 30. It is arranged on the visual side of the optical cell so as to be. By arranging in this way, it is possible to exhibit a metallic opaque gloss (color metallic) with a tint due to the light-transmitting colored layer 40, and as a result, the peripheral portion such as the housing and the tint can be exhibited. It is possible to realize a display screen in which both the texture and the texture are in harmony.

In FIG. 2, the light-transmitting colored layer 40 is arranged between the light-diffusing layer 10 and the light-transmitting reflector 20, but the optical laminate of the present invention is not limited to this configuration. For example, the light-transmitting colored layer 40 may be arranged on the visual side of the light-diffusing layer 10, and the light-transmitting colored layer 10 may also serve as the light-transmitting colored layer 40.

In the optical laminate 100a or 100b, protective layers (first protective layer 52, second protective layer 54) are arranged on both sides of the absorption type polarizing element 30, but whichever is used depending on the purpose and configuration. One (eg, first protective layer 52) or both protective layers may be omitted.

The components constituting the optical laminate 100a or 100b are laminated via any appropriate adhesive layer (not shown) such as an adhesive layer and an adhesive layer, if necessary. , It is closely laminated without going through an adhesive layer. Further, on the side of the second protective layer 54 opposite to the side on which the absorption type polarizer 30 is arranged, an adhesive layer or the like for bonding the optical laminate 100a or 100b to the adjacent member is provided, if necessary. It may be provided.

The glossiness of the optical laminate can be appropriately adjusted by the design of the peripheral portion of the display screen, but is, for example, 130% or less, preferably 120% or less, more preferably 110% or less, still more preferably. It can be 100% or less. Further, the lower limit of the glossiness of the optical laminate can be, for example, 40%. When the glossiness is within the above range, it is possible to realize a display screen in which a metallic opaque gloss is exhibited and the texture is in harmony with the peripheral portion such as the housing when the image display device is not displayed. The glossiness means mirror glossiness and can be obtained by the method specified in JIS Z8741-1997.

The metric saturation of the reflected light in the SCI method of the optical laminate can be appropriately adjusted by the design of the peripheral portion of the display screen, but is typically 3 or more, for example 5 or more, and for example 10 or more. Also, for example, it can be 20 or more. Further, the upper limit of the metric saturation of the reflected light can be, for example, 80. The metric saturation is ^{a value obtained by the following equation using the a *} value and the b ^{* value in the L *} a ^* b ^* color system, and represents the distance from the central axis (achromatic axis) of the color space.
Metric saturation (C ^* ) = √ (a ^{* 2} + b ^{* 2} )

The simple substance transmittance of the optical laminate is, for example, 3% or more, preferably 5% or more, and more preferably 30% or more. Further, the simple substance transmittance can be, for example, 46% or less, and can be, for example, 40% or less. By having such a transmittance, an image by an image display device can be clearly displayed.

B-2. Light diffusing layer The light diffusing layer may be made of a light diffusing element or a light diffusing adhesive. The light diffusing element includes a matrix made of a solidified or cured resin and light diffusing fine particles dispersed in the matrix. In the light diffusing pressure-sensitive adhesive, the matrix is composed of the pressure-sensitive adhesive.

The light diffusion performance of the light diffusion layer can be expressed by, for example, a haze value. The haze value of the light diffusing layer can be appropriately set according to the design of the peripheral portion of the display screen. When the light diffusing layer is arranged on the outermost surface of the optical laminate, the haze value of the light diffusing layer is, for example, 5% or more, preferably 10% or more. When the light diffusing layer is arranged inside the optical laminate, the haze value of the light diffusing layer is, for example, 5% or more, preferably 10% or more, more preferably 30% or more, and further preferably 50. % Or more. By setting the haze value in the above range, it is possible to realize a display screen in which the image display device exhibits a metallic opaque gloss when the image display device is not displayed, and the image by the image display device can be clearly seen when the image display device is displayed. The light diffusing performance of the light diffusing layer can be determined by adjusting the constituent materials of the matrix (adhesive in the case of the light diffusing adhesive), the constituent materials of the light diffusing fine particles, the volume average particle size, the blending amount, and the like. Can be controlled.

The simple substance transmittance of the light diffusion layer is preferably 70% or more, more preferably 80% or more, and further preferably 90% or more.

The thickness of the light diffusion layer can be appropriately adjusted according to the configuration, diffusion performance, and the like. For example, when the light diffusing layer is composed of a light diffusing element, the thickness is preferably 5 μm to 200 μm. Further, for example, when the light diffusion layer is composed of a light diffusion adhesive, the thickness is preferably 5 μm to 100 μm.

When the light diffusing layer is made of a light diffusing element, the matrix is made of, for example, an ionizing wire curable resin. Examples of the ionized wire include ultraviolet rays, visible light, infrared rays, and electron beams. It is preferably UV light, and therefore the matrix is preferably composed of UV curable resin. Examples of the ultraviolet curable resin include acrylic resins, aliphatic (for example, polyolefin) resins, and urethane resins. The form of the light diffusing fine particles in which the light diffusing layer is composed of the light diffusing adhesive will be described later.

The light diffusing element is a resin film that forms an arbitrary suitable base material (for example, a protective layer) with a coating liquid for forming a light diffusing element (for example, a dispersion liquid containing a curable resin for forming a matrix and light diffusing fine particles). ) Can be obtained by coating on, curing and / or drying. Moreover, you may use a commercially available light diffusing film.

When the light diffusing layer is composed of a light diffusing pressure-sensitive adhesive, the light diffusing layer contains the pressure-sensitive adhesive and light-diffusing fine particles dispersed in the pressure-sensitive adhesive. Any suitable adhesive can be used as the pressure-sensitive adhesive. Specific examples thereof include rubber-based pressure-sensitive adhesives, acrylic-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, epoxy-based pressure-sensitive adhesives, cellulose-based pressure-sensitive adhesives, and the like, and acrylic-based pressure-sensitive adhesives are preferable. By using an acrylic pressure-sensitive adhesive, a light diffusion layer having excellent heat resistance and transparency can be obtained. The pressure-sensitive adhesive may be used alone or in combination of two or more.

Any suitable acrylic adhesive can be used. The glass transition temperature of the acrylic pressure-sensitive adhesive is preferably −60 ° C. to −10 ° C., more preferably −55 ° C. to −15 ° C. The weight average molecular weight of the acrylic pressure-sensitive adhesive is preferably 200,000 to 2 million, more preferably 250,000 to 1.8 million. By using an acrylic pressure-sensitive adhesive having such characteristics, appropriate pressure-sensitive adhesiveness can be obtained. The refractive index of the acrylic pressure-sensitive adhesive is preferably 1.40 to 1.65, and more preferably 1.45 to 1.60.

The acrylic pressure-sensitive adhesive is usually obtained by polymerizing a main monomer that imparts tackiness, a comonomer that imparts cohesiveness, and a functional group-containing monomer that serves as a cross-linking point while imparting tackiness. Acrylic adhesives having the above properties can be synthesized by any appropriate method. For example, they can be synthesized with reference to "Adhesive / Adhesive Chemistry and Applications" published by Dainippon Tosho Co., Ltd., Katsuhiko Nakamae.

The content of the pressure-sensitive adhesive in the light diffusion layer is preferably 50% by weight to 99.7% by weight, more preferably 52% by weight to 97% by weight.

Any suitable light diffusing fine particles can be used. Specific examples include inorganic fine particles and polymer fine particles. The light diffusing fine particles are preferably polymer fine particles. Examples of the material of the polymer fine particles include silicone resin, methacrylic resin (for example, polymethyl methacrylate), polystyrene resin, polyurethane resin, and melamine resin. Since these resins have excellent dispersibility with respect to the pressure-sensitive adhesive and an appropriate refractive index difference with the pressure-sensitive adhesive, a light diffusion layer having excellent diffusion performance can be obtained. Preferably, it is a silicone resin or polymethyl methacrylate. The shape of the light diffusing fine particles can be, for example, a true spherical shape, a flat shape, or an indefinite shape. The light diffusing fine particles may be used alone or in combination of two or more.

The volume average particle size of the light diffusing fine particles is preferably 1 μm to 10 μm, and more preferably 1.5 μm to 6 μm. By setting the volume average particle size in the above range, a light diffusing layer having excellent light diffusing performance can be obtained. The volume average particle size can be measured using, for example, an ultracentrifugal automatic particle size distribution measuring device.

The refractive index of the light diffusing fine particles is preferably 1.30 to 1.70, and more preferably 1.40 to 1.65.

The absolute value of the difference in refractive index between the light diffusing fine particles and the matrix (typically, an ionizing wire curable resin or an adhesive) is preferably more than 0 and 0.2 or less, and more preferably more than 0. It is 0.15 or less, more preferably 0.01 to 0.13.

The content of the light diffusing fine particles in the light diffusing layer is preferably 0.3% by weight to 50% by weight, more preferably 3% by weight to 48% by weight. By setting the blending amount of the light diffusing fine particles within the above range, a light diffusing layer having excellent light diffusing performance can be obtained.

B-3. Light-transmitting reflector The light-transmitting reflector has transmission characteristics and reflection characteristics that reflect a part of incident light and transmit the remaining light. The single transmittance of the light-transmitting reflector is preferably 10% to 70%, more preferably 15% to 65%, and even more preferably 20% to 60%. The reflectance of the light-transmitting reflector is preferably 30% or more, more preferably 40% or more, still more preferably 45% or more. As the light transmissive reflector, for example, a half mirror, a reflective polarizer, a louver film, or the like can be used.

As the half mirror, for example, a multilayer laminate in which two or more dielectric films having different refractive indexes are laminated can be used. Such a half mirror preferably has a metallic luster.

Examples of the material for forming the dielectric film include metal oxides, metal nitrides, metal fluorides, thermoplastic resins (for example, polyethylene terephthalate (PET)) and the like. The multilayer laminated body of the dielectric film reflects a part of the incident light at the interface due to the difference in the refractive index of the laminated dielectric films. The reflectance can be adjusted by changing the phase of the incident light and the reflected light according to the thickness of the dielectric film and adjusting the degree of interference between the two lights. The thickness of the half mirror made of a multilayer laminate of dielectric films can be, for example, 50 μm to 200 μm. As such a half mirror, for example, a commercially available product such as the trade name "Picassus" manufactured by Toray Industries, Inc. can be used.

The half mirror includes, for example, aluminum (Al), indium (In), zinc (Zn), lead (Pb), copper (Cu), silver (Ag), or an alloy thereof on a resin film such as PET. A metal-deposited film on which a metal such as the above is vapor-deposited can be used. The metal vapor-deposited film has a metallic luster due to reflection when observed from the vapor-deposited film side, but can transmit light from the resin film side, and by changing the vapor-deposited film thickness, the light transmittance Can be controlled. The vapor deposition film thickness is preferably 1 nm to 50 nm, more preferably 10 nm to 30 nm. The film thickness of the resin film is preferably 1 μm to 1000 μm, more preferably 20 μm to 100 μm.

The reflective polarizer has a function of transmitting polarized light in a specific polarized state (polarizing direction) and reflecting light in other polarized states. The reflective polarizer may be a linearly polarized light separated type or a circularly polarized light separated type, but a linearly polarized light separated type is preferable. The linearly polarized light separation type reflective polarizer is arranged so that the reflection axis direction is substantially parallel to the absorption axis direction of the absorption type polarizer. Hereinafter, as an example, a linearly polarized light separation type reflective polarizer will be described. Examples of the circularly polarized light separation type reflective polarizer include a laminate of a film on which a cholesteric liquid crystal is immobilized and a λ / 4 plate.

FIG. 3 is a schematic perspective view of an example of a reflective polarizer. The reflective polarizer is a multilayer laminate in which a layer A having birefringence and a layer B having substantially no birefringence are alternately laminated. For example, the total number of layers of such a multi-layer laminate can be 50-1000. In the illustrated example, the refractive index nx in the x-axis direction of the A layer is larger than the refractive index ny in the y-axis direction, and the refractive index nx in the x-axis direction of the B layer and the refractive index ny in the y-axis direction are substantially the same. is there. Therefore, the difference in refractive index between the A layer and the B layer is large in the x-axis direction and substantially zero in the y-axis direction. As a result, the x-axis direction becomes the reflection axis, and the y-axis direction becomes the transmission axis. The difference in refractive index between the A layer and the B layer in the x-axis direction is preferably 0.2 to 0.3. The x-axis direction corresponds to the stretching direction of the reflective polarizer in the manufacturing method described later.

The layer A is preferably composed of a material that exhibits birefringence by stretching. Representative examples of such materials include polyester naphthalenedicarboxylic acid (eg, polyethylene naphthalate), polycarbonate and acrylic resins (eg, polymethylmethacrylate). Polyethylene naphthalate is preferred. The B layer is preferably composed of a material that does not substantially exhibit birefringence even when stretched. A typical example of such a material is a copolyester of naphthalenedicarboxylic acid and terephthalic acid.

The reflective polarizing element transmits light having a first polarization direction (for example, a p wave) at the interface between the A layer and the B layer, and has a second polarization direction orthogonal to the first polarization direction. Reflects light (eg, s waves). At the interface between the A layer and the B layer, the reflected light is partially transmitted as light having a first polarization direction and partially reflected as light having a second polarization direction. By repeating such reflection and transmission many times inside the reflective polarizer, the efficiency of light utilization can be improved.

In one embodiment, the reflective polarizer may include a reflective layer R as the outermost layer on the side opposite to the visual viewing side, as shown in FIG. By providing the reflective layer R, it is possible to further utilize the light that has returned to the outermost side of the reflective polarizer without being finally utilized, so that the efficiency of light utilization can be further improved. The reflective layer R typically exhibits a reflective function due to the multilayer structure of the polyester resin layer.

The overall thickness of the reflective polarizer can be appropriately set according to the purpose, the total number of layers contained in the reflective polarizer, and the like. The overall thickness of the reflective polarizer is preferably 10 μm to 150 μm.

The reflective polarizer can be typically produced by combining coextrusion and transverse stretching. Coextrusion can be done in any suitable manner. For example, it may be a feed block system or a multi-manifold system. For example, the material forming the A layer and the material forming the B layer are extruded in the feed block, and then multi-layered using a multiplier. Such a multi-layer device is known to those skilled in the art. Next, the obtained elongated multilayer laminate is typically stretched in a direction (TD) orthogonal to the transport direction. The material (for example, polyethylene naphthalate) constituting the layer A has an increased refractive index only in the stretching direction due to the lateral stretching, and as a result, exhibits birefringence. The refractive index of the material constituting the B layer (for example, copolyester of naphthalenedicarboxylic acid and terephthalic acid) does not increase in any direction by the transverse stretching. As a result, a reflective polarizer having a reflection axis in the stretching direction (TD) and a transmission axis in the transport direction (MD) can be obtained (TD corresponds to the x-axis direction of FIG. 3 and MD corresponds to the y-axis. Corresponds to the direction). The stretching operation can be performed using any suitable device.

As the reflective polarizer, for example, those described in JP-A-9-507308 can be used. Further, as the reflective polarizer, a commercially available product may be used as it is, or the commercially available product may be used after secondary processing (for example, stretching). Examples of commercially available products include the product name "APCF" manufactured by Nitto Denko Corporation, the product name "DBEF" manufactured by 3M Company, and the product name "APF" manufactured by 3M Company.

B-4. Absorption-type polarizer The absorption-type polarizer (hereinafter, may be simply referred to as “polarizer”) is typically composed of a resin film containing iodine. As the resin film, any suitable resin film that can be used as a polarizer can be adopted. The resin film is typically a polyvinyl alcohol-based resin (hereinafter, referred to as “PVA-based resin”) film. The resin film may be a single-layer resin film or a laminated body having two or more layers.

Specific examples of the polarizer composed of a single-layer resin film include those obtained by subjecting a PVA-based resin film to a dyeing treatment with iodine and a stretching treatment (typically, uniaxial stretching). The dyeing with iodine is performed, for example, by immersing a PVA-based film in an aqueous iodine solution. The draw ratio of the uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after the dyeing treatment or while dyeing. Alternatively, it may be stretched and then dyed. If necessary, the PVA-based resin film is subjected to a swelling treatment, a cross-linking treatment, a cleaning treatment, a drying treatment and the like. For example, by immersing the PVA-based resin film in water and washing it with water before dyeing, not only can the stains on the surface of the PVA-based film and the blocking inhibitor be washed, but also the PVA-based resin film is swollen to cause uneven dyeing. Etc. can be prevented.

Specific examples of the polarizer obtained by using the laminate include a laminate of a resin base material and a PVA-based resin layer (PVA-based resin film) laminated on the resin base material, or a resin base material and the resin. Examples thereof include a polarizer obtained by using a laminate with a PVA-based resin layer coated and formed on a base material. The polarizer obtained by using the laminate of the resin base material and the PVA-based resin layer coated and formed on the resin base material is, for example, a resin base material obtained by applying a PVA-based resin solution to the resin base material and drying the resin base material. It is produced by forming a PVA-based resin layer on the resin layer to obtain a laminate of a resin base material and a PVA-based resin layer; and stretching and dyeing the laminate to use the PVA-based resin layer as a polarizer. obtain. In the present embodiment, stretching typically includes immersing the laminate in an aqueous boric acid solution for stretching. Further, stretching may further include, if necessary, stretching the laminate in the air at a high temperature (eg, 95 ° C. or higher) prior to stretching in boric acid aqueous solution. The obtained resin base material / polarizer laminate may be used as it is (that is, the resin base material may be used as a protective layer for the polarizer), and the resin base material is peeled off from the resin base material / polarizer laminate. Then, an arbitrary appropriate protective layer according to the purpose may be laminated on the peeled surface. Details of the method for producing such a polarizer are described in, for example, Japanese Patent Application Laid-Open No. 2012-73580 and Japanese Patent No. 6470455. The entire description of these publications is incorporated herein by reference.

The thickness of the polarizer is preferably 40 μm or less, more preferably 30 μm or less. Further, the lower limit of the thickness may be, for example, 2 μm, or for example, 3 μm.

The polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The simple substance transmittance of the polarizer is preferably 43.0% to 46.0%, 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.

B-5. Light-Transparent Colored Layer As the light-transmitting colored layer, a layer having a single transmittance of 15% or more, preferably 40% or more, more preferably 80% or more, and an object color of color is used. The upper limit of the single transmittance of the light-transmitting colored layer can be, for example, 95%, or 93%, for example. Further, the object color of the light-transmitting colored layer, which is colored, may be a color generated by transmitted light (transmitted color) and / or a color emitted by reflection (surface color).

The color of the object color of the light-transmitting colored layer can be appropriately selected according to the design of the peripheral portion of the display screen. For example, the light-transmitting colored layer may be a single color, may have multiple colors and / or shades, and may form a pattern.

The light-transmitting colored layer is, for example, a component of a conventional polarizing plate having a polarizing element containing iodine and a protective layer provided on at least one side thereof, and the polarizing plate is arranged on the visible side of an optical cell. When this is done, a colored component arranged on the visual side of the polarizing element is used. Examples of such a component include a protective layer, an adhesive layer, an adhesive layer and the like. Among them, those in which the protective layer and / or the pressure-sensitive adhesive layer are colored are preferable, and those in which the pressure-sensitive adhesive layer is colored can be more preferably used. Coloring can be performed by mixing a colorant with the forming material of the above components (eg, protective layer or pressure-sensitive adhesive layer). The type of colorant and the amount thereof can be appropriately selected according to the design of the peripheral portion of the display screen. Further, the protective layer may be colored by providing a colored coating layer on the surface of the protective layer.

In one embodiment, the light-transmitting colored layer containing the colorant selectively absorbs light in a specific wavelength range between wavelengths of 380 nm to 780 nm (that is, absorption maximum in a specific wavelength band). Has a wavelength). The light-transmitting colored layer may have two or more absorption maximum wavelengths. A light-transmitting colored layer having two or more absorption maximum wavelengths can be obtained, for example, by using a plurality of types of colorants.

The transmittance of the light-transmitting colored layer at the absorption maximum wavelength is preferably 15% to 80%, more preferably 15% to 70%. When the transmittance of the absorption layer at the absorption maximum wavelength is within such a range, the effect of the present invention can be suitably exhibited.

The thickness of the light-transmitting colored layer is preferably 1 μm to 100 μm, and more preferably 2 μm to 30 μm. When the thickness of the light-transmitting colored layer is within such a range, the effect of the present invention can be suitably exhibited.

Specific examples of colorants include, for example, anthraquinone-based, triphenylmethane-based, naphthoquinone-based, thioindigo-based, perinone-based, perylene-based, squarylium-based, cyanine-based, porphyrin-based, azaporphyrin-based, phthalocyanine-based, subphthalocyanine-based, Quinoline, polymethin, rhodamine, oxonor, quinone, azo, xanthene, azomethin, quinacridone, dioxazine, diketopyrrolopyrrole, anthraquinone, isoindrinone, indanslon Examples thereof include dyes such as indigo-based, thioindigo-based, quinophthalone-based, quinoline-based, and triphenylmethane-based dyes.

A pigment may be used as the colorant. Specific examples of pigments include black pigments (carbon black, bone black, graphite, iron black, titanium black, etc.), azo pigments, phthalocyanine pigments, polycyclic pigments (quinacridone, perylene, perinone, etc.). Isoindrinone-based, isoindolin-based, dioxazine-based, thioindigo-based, anthraquinone-based, quinophthalone-based, metal complex-based, diketopyrrolopyrrole-based, dye lake pigments, white / extender pigments (titanium oxide, zinc oxide, sulfide) Zinc, clay, talc, barium sulfate, calcium carbonate, etc.), chromatic pigments (yellow lead, cadmium, chrome vermilion, nickel titanium, chrome titanium, yellow iron oxide, red iron oxide, zinc chromate, lead tan, ultramarine, dark blue, Cobalt blue, chrome green, chromium oxide, bismuth vanadate, etc.), bright material pigments (pearl pigments, aluminum pigments, bronze pigments, etc.), fluorescent pigments (zinc sulfide, strontium sulfide, strontium aluminate, etc.) and the like can be mentioned.

The content ratio of the colorant can be any appropriate ratio depending on the type of the colorant, the desired light absorption characteristics, and the like. The content ratio of the colorant in the light-transmitting colored layer is preferably 0.01% by weight to 5.00% by weight, more preferably 0.05% by weight to 3.00% by weight.

Further, for example, a polarizer containing a dichroic substance other than iodine (hereinafter, may be referred to as a "dyed polarizer") can be used as a light-transmitting colored layer. In this case, by arranging the absorption axis direction of the absorption type polarizer and the absorption axis direction of the dyed polarizer so as to be substantially parallel, the light transmissive colored layer in the image displayed by the image display device is caused. Coloring can be suppressed. The dyed polarizer and the method for producing the same are described in, for example, Japanese Patent Application Laid-Open No. 06-666001, Japanese Patent Application Laid-Open No. 2012-73580, and Japanese Patent Application Laid-Open No. 2018-22125. The entire description of the publication is incorporated herein by reference.

The dyed polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The simple substance transmittance of the dyed polarizer is, for example, 10% to 90%, preferably 10% to 80%, and more preferably 20% to 70%. The degree of polarization of the dyed polarizer is, for example, 15% or more, preferably 40% or more, more preferably 80% or more, still more preferably 90% or more.

FIG. 4 is a schematic cross-sectional view of an example of an optical laminate having a light-transmitting colored layer. The optical laminate 100c includes a light diffusing element 10a, a third protective layer 56, a light transmitting colored layer (for example, a colored pressure-sensitive adhesive layer, a dyed polarizing element) 40, a light transmitting reflector 20, and the light transmitting reflector 20. The absorption type polarizer 30 is provided in this order from the viewing side.

FIG. 5 is a schematic cross-sectional view of another example of an optical laminate having a light-transmitting colored layer. The optical laminate 100d includes a third protective layer (surface protective layer) 56, a light diffusing pressure-sensitive adhesive layer 10b, a light-transmitting colored layer (for example, a colored pressure-sensitive adhesive layer, a dyed polarizing element) 40, and light. The transmissive reflector 20 and the absorption type polarizer 30 are provided in this order.

FIG. 6 is a schematic cross-sectional view of another example of an optical laminate having a light-transmitting colored layer. The optical laminate 100e includes a third protective layer (surface protective layer) 56, a colored light diffusing adhesive layer 10b (which also serves as a light transmissive colored layer 40), a light transmissive reflector 20, and an absorption type. The polarizer 30 is provided in this order from the viewing side.

B-6. Protective layer The protective layer is formed of any suitable film that can be used as a protective layer for the polarizer. The protective layer is preferably colorless and transparent, and has a transmittance of 85% or more, preferably 93% or more, for example, over the entire measurement wavelength region of 420 nm to 780 nm.

Specific examples of the material that is the main component of the film forming the protective layer include cellulose resins such as triacetyl cellulose (TAC), polyesters, polyvinyl alcohols, polycarbonates, polyamides, polyimides, and polyethers. Examples thereof include transparent resins such as sulfone-based, polysulfone-based, polystyrene-based, polynorbornene-based, polyolefin-based, (meth) acrylic-based, and acetate-based. Further, thermosetting resins such as (meth) acrylic, urethane, (meth) acrylic urethane, epoxy, and silicone, or ultraviolet curable resins can also be mentioned. In addition to this, for example, glassy polymers such as siloxane-based polymers can also be mentioned. Further, the polymer film described in JP-A-2001-343529 (WO01 / 37007) can also be used. As the material of this film, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in the side chain. Can be used, and examples thereof include a resin composition having an alternating copolymer composed of isobutene and N-methylmaleimide and an acrylonitrile / styrene copolymer. The polymer film can be, for example, an extruded product of the above resin composition.

In one embodiment, as the (meth) acrylic resin, a (meth) acrylic resin having a cyclic structure such as a lactone ring or a glutarimide ring in the main chain is used. Examples of the (meth) acrylic resin having a glutarimide ring (hereinafter, also referred to as glutarimide resin) include JP-A-2006-309033, JP-A-2006-317560, JP-A-2006-328329, and JP-A. 2006-328334, 2006-337491, 2006-337492, 2006-337493, 2006-337569, 2007-009182, 2009- It is described in Japanese Patent Application Laid-Open No. 161744 and Japanese Patent Application Laid-Open No. 2010-284840. These statements are incorporated herein by reference.

When the optical laminate is applied to an image display device, the thickness of the outer protective layers (protective layers 52 and 56) arranged on the visual side of the absorption type polarizer is typically 300 μm or less, preferably 100 μm. Hereinafter, it is more preferably 5 μm to 80 μm, still more preferably 10 μm to 60 μm. When the surface treatment is applied, the thickness of the outer protective layer is the thickness including the thickness of the surface treatment layer.

When the optical laminate is applied to an image display device, the thickness of the inner protective layer (protective layer 54) arranged on the optical cell side of the absorption type polarizer is preferably 5 μm to 200 μm, more preferably 10 μm to 100 μm. More preferably, it is 10 μm to 60 μm. In one embodiment, the inner protective layer is a retardation layer with any suitable retardation value. In this case, the in-plane retardation Re (550) of the retardation layer is, for example, 110 nm to 150 nm. “Re (550)” is an in-plane phase difference measured with light having a wavelength of 550 nm at 23 ° C., and is obtained by the formula: Re = (nx−ny) × d. Here, "nx" is the refractive index in the direction in which the in-plane refractive index is maximized (that is, the slow-phase axis direction), and "ny" is the in-plane direction orthogonal to the slow-phase axis (that is, phase-advance). It is the refractive index in the axial direction), “nz” is the refractive index in the thickness direction, and “d” is the thickness (nm) of the layer (film).

B-7. Adhesive layer The adhesive layer is typically an adhesive layer or an adhesive layer. The adhesive layer is preferably colorless and transparent, and has a transmittance of 80% or more, preferably 90% or more over the entire measurement wavelength region of 420 nm to 780 nm.

Any suitable 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, and curable adhesive compositions such as ultraviolet curable adhesives and electron beam-curable adhesives. And so on. The thickness of the adhesive layer can be, for example, 0.05 μm to 1.5 μm.

Any suitable pressure-sensitive adhesive composition can be used as the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer. Examples thereof include rubber-based, acrylic-based, silicone-based, urethane-based, vinyl alkyl ether-based, polyvinyl alcohol-based, polyvinylpyrrolidone-based, polyacrylamide-based, and cellulose-based pressure-sensitive adhesive compositions. Among them, an acrylic pressure-sensitive adhesive composition is preferably used because of its excellent optical transparency, 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.

C. Image display device The optical laminate according to item B above can be applied to an image display device. Therefore, the present invention includes an image display device including the above optical laminate. Typical examples of the image display device include a liquid crystal display device provided with a liquid crystal cell, an organic EL display device provided with an organic electroluminescence (EL) cell, and the like. In one embodiment, the optical laminate is arranged on the visible side of an optical cell such as a liquid crystal cell or an organic EL cell so that the light transmissive reflector is on the visible side of the absorption type polarizer. Since the liquid crystal cell and the organic EL cell are not characteristic parts of the present invention and can adopt a configuration well known in the industry, detailed description thereof will be omitted.

FIG. 7 is a schematic cross-sectional view of a liquid crystal display device according to one embodiment of the present invention. The liquid crystal display device 200 includes a liquid crystal panel 160 and a backlight unit 180 having an optical laminate 100, a liquid crystal cell 120, and a backside polarizing element 140 in this order from the viewing side. The optical laminate 100 is the optical laminate according to item B, so that the light transmissive reflector 20 is on the visual side of the absorption type polarizer 30 and the absorption shaft and the back surface of the absorption type polarizer 30. It is arranged so that the absorption axis of the side polarizer 140 is substantially orthogonal to the absorption axis. As the back side polarizer, the same one as that of the absorption type polarizer can be used.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. The measurement method of each characteristic is as follows. Unless otherwise specified, "parts" and "%" in Examples and Comparative Examples are based on weight.

(1) Thickness Measured using a digital gauge (manufactured by Ozaki Seisakusho Co., Ltd., product name "PEACOCK").
(2) Reflected Hue and Metric Saturation From the reflected hues a * and b * measured with a spectrophotometer (CM-2600d manufactured by Konica Minolta) for the optical laminate, the metric saturation was calculated using the following formula. I asked.
Metric saturation (C ^* ) = √ (a ^{* 2} + b ^{* 2} )
(3) Single Transmittance and Degree of Polarization of Polarizer For the iodine-based polarizer, the polarizing plate A (iodine-based polarizer / protective layer) obtained in Production Example 1 was used as an ultraviolet-visible near-infrared spectrophotometer (Japan). The single transmittance Ts, the parallel transmittance Tp, and the orthogonal transmittance Tc measured using V-7100) manufactured by Spectronizing Co., Ltd. were defined as the polarizers Ts, Tp, and Tc, respectively. These Ts, Tp and Tc are Y values measured by the JIS Z8701 2 degree field of view (C light source) and corrected for luminosity factor. From the obtained Tp and Tc, the degree of polarization was determined using the following formula.
Polarization degree (%) = {(Tp-Tc) / (Tp + Tc)} ^1/2 x 100
The dyed polarizers obtained in Production Examples 2 to 4 were also measured by the same method.
(4) Glossiness The glossiness of the optical laminate was measured using a glossiness meter (manufactured by Murakami Color Chemistry Laboratory, trade name "GM-26 PRO") by the method specified in JIS Z8741-1997.
(5) Single Transmittance The transmittance Ts having a wavelength of 380 nm to 780 nm as measured using an ultraviolet-visible near-infrared spectrophotometer (V-7100 manufactured by JASCO Corporation) was defined as the single transmittance Ts. However, the single transmittance of the light-transmitting reflector was measured using an ultraviolet-visible near-infrared spectrophotometer (U-4100 or UH-4150 manufactured by Hitachi High-Tech Science Co., Ltd.). This Ts is a Y value measured by a JIS Z8701 double field of view (C light source) and corrected for luminosity factor.
(6) Haze value The light diffusing layer was measured using a haze meter (manufactured by Murakami Color Science Laboratory Co., Ltd., trade name "HN-150") by the method specified by JIS 7136.

<Manufacturing Example 1 Fabrication of Polarizing Plate>
As the thermoplastic resin base material, an amorphous isophthal copolymer polyethylene terephthalate film (thickness: 100 μm) having a long shape and a Tg of about 75 ° C. was used, and one side of the resin base material was subjected to corona treatment.
100 parts by weight of PVA-based resin in which polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gosefimmer") are mixed at a ratio of 9: A PVA aqueous solution (coating solution) was prepared by dissolving 13 parts by weight of potassium iodide in water.
The PVA aqueous solution was applied to the corona-treated surface of the resin base material and dried at 60 ° C. to form a PVA-based resin layer having a thickness of 13 μm to prepare a laminate.
The obtained laminate was uniaxially stretched 2.4 times in the longitudinal direction (longitudinal direction) in an oven at 130 ° C. (aerial auxiliary stretching treatment).
Next, the laminate was immersed in an insolubilizing bath at a liquid temperature of 40 ° C. (an aqueous boric acid solution obtained by blending 4 parts by weight of boric acid with 100 parts by weight of water) for 30 seconds (insolubilization treatment).
Next, in a dyeing bath having a liquid temperature of 30 ° C. (an aqueous iodine solution obtained by mixing iodine and potassium iodide in a weight ratio of 1: 7 with respect to 100 parts by weight of water), the polarizer finally obtained Immersion was carried out for 60 seconds while adjusting the concentration so that the simple substance transmittance (Ts) became a desired value (staining treatment).
Then, it was immersed in a cross-linked bath at a liquid temperature of 40 ° C. (an aqueous boric acid solution obtained by blending 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with respect to 100 parts by weight of water) for 30 seconds. (Crossing treatment).
Then, while immersing the laminate in a boric acid aqueous solution (boric acid concentration 4% by weight, potassium iodide concentration 5% by weight) at a liquid temperature of 70 ° C., the total in the longitudinal direction (longitudinal direction) between rolls having different peripheral speeds. Uniaxial stretching was performed so that the stretching ratio was 5.5 times (underwater stretching treatment).
Then, the laminate was immersed in a washing bath at a liquid temperature of 20 ° C. (an aqueous solution obtained by blending 4 parts by weight of potassium iodide with 100 parts by weight of water) (cleaning treatment).
Then, while drying in an oven kept at about 90 ° C., it was brought into contact with a heating roll made of SUS whose surface temperature was kept at about 75 ° C. (dry shrinkage treatment).
In this way, an iodine-based polarizer (absorption-type polarizer) having a thickness of about 5 μm was formed on the resin substrate, and a laminate having a resin substrate / iodine-based polarizer configuration was obtained.
An acrylic resin film (thickness: 40 μm) having a lactone ring structure as a protective layer is applied to the surface of the iodine-based polarizer obtained above (the surface opposite to the resin base material) via an ultraviolet curable adhesive. And pasted together. Next, the resin base material was peeled off to obtain a polarizing plate A having an iodine-based polarizer / protective layer structure. The single-unit transmittance of the polarizing plate A (substantially an iodine-based polarizing element) was 42.4%, and the degree of polarization was 99.999%.

<Manufacturing Example 2 Production of Red Polarizer>
A red polarizing element in the same manner as in Production Example 1 except that 4 parts of Direct Red 81 (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the dyeing bath instead of iodine with respect to 100 parts by weight of water. Got The simple substance transmittance of the polarizer was 44.4%, and the degree of polarization was 58.6%.

<Manufacturing Example 3 Production of Blue Polarizer>
A blue polarizer was obtained in the same manner as in Production Example 2 except that 4 parts of Direct Blue 1 (manufactured by Tokyo Chemical Industry Co., Ltd.) was used as the dichroic dye. The simple substance transmittance of the polarizer was 42.1%, and the degree of polarization was 68.9%.

<Manufacturing Example 4 Production of Yellow Polarizer>
A yellow polarizer was obtained in the same manner as in Production Example 2 except that 4 parts of Direct Yellow 4 (manufactured by Tokyo Chemical Industry Co., Ltd.) were used as the dichroic dye. The simple substance transmittance of the polarizer was 79.9%, and the degree of polarization was 17.9%.

<Manufacturing Example 5 Production of Red Adhesive Sheet>
≪Preparation of adhesive composition≫
100 parts of a monomer mixture containing 2-ethylhexyl acrylate (2EHA), NVP, and hydroxyethyl acrylate (HEA) in a weight ratio of 78/18/4 as a photopolymerization initiator, trade name: Irgacure 651 (manufactured by Ciba Specialty Chemicals). ) 0.035 parts and trade name: Irgacure 184 (manufactured by Ciba Specialty Chemicals) 0.035 parts and put into a four-necked flask, and the viscosity (BH viscometer, No. 5 rotor, 10 rpm, measurement) under a nitrogen atmosphere. A monomer syrup containing a partial polymer of the above-mentioned monomer mixture was prepared by irradiating with ultraviolet rays until the temperature (temperature: 30 ° C.) reached about 15 Pa · s and photopolymerizing.
In 100 parts of this monomer syrup, 17.6 parts of hydroxyethyl acrylate (HEA), 5.9 parts of acrylic oligomer, 0.088 part of 1,6-hexanediol diacrylate (HDDA), and 3-glyceride as a silane coupling agent. Sidoxypropyltrimethoxysilane (trade name: KBM-403, manufactured by Shin-Etsu Chemical Industry Co., Ltd.) 0.35 part, Ajinomoto Fine-Techno Co., Ltd. azisper PB821 as a dispersant, 2,9-Dimethylquinolino [2,3-b] as a pigment A red pressure-sensitive adhesive composition was prepared by blending 0.05 parts by mass of aryline-7,14 (5H, 12H) -dione (manufactured by BLD Phasetech Ltd.).

As the acrylic oligomer, one synthesized by the following method was used.
≪Synthesis of acrylic oligomer≫
100 parts of toluene, 60 parts of dicyclopentanyl methacrylate (DCPMA) (trade name: FA-513M, manufactured by Hitachi Kasei Kogyo Co., Ltd.), 40 parts of methyl methacrylate (MMA), and 3.5 parts of α-thioglycerol as a chain transfer agent. Was put into a four-necked flask. Then, after stirring at 70 ° C. in a nitrogen atmosphere for 1 hour, 0.2 part of AIBN was added as a thermal polymerization initiator, and the mixture was reacted at 70 ° C. for 2 hours and then at 80 ° C. for 2 hours. Then, the reaction solution was put into a temperature atmosphere of 130 ° C., and toluene, the chain transfer agent, and the unreacted monomer were dried and removed to obtain a solid acrylic oligomer. The Tg of this acrylic oligomer was 144 ° C. and the Mw was 4300.

≪Preparation of adhesive sheet≫
The red adhesive composition obtained above is applied to a release film R1 (MRF # 38, manufactured by Mitsubishi Resin Co., Ltd.) having a thickness of 38 μm in which one side of the polyester film is a release surface, and one side of the polyester film is a release surface. By covering with a 38 μm thick release film R2 (MRE # 38 manufactured by Mitsubishi Resin Co., Ltd.) to block air and irradiating with ultraviolet rays to cure, the thickness is 50 μm and the single transmission rate is 19.3%. A red pressure-sensitive adhesive sheet (red pressure-sensitive adhesive layer) was formed.

<Manufacturing Example 6 Production of Blue Adhesive Sheet>
Similar to Production Example 5, thickness 50 μm, single transmission, except that 0.05 parts of blue pigment (manufactured by Tokyo Chemical Industry Co., Ltd., product name “Pigment Blue 15”) was used instead of 0.05 parts of red pigment. A blue pressure-sensitive adhesive sheet having a rate of 24.2% was obtained.

<Manufacturing Example 7 Production of Yellow Adhesive Sheet>
Similar to Production Example 5, except that 0.05 parts of a yellow pigment (manufactured by Oakwood Products, Inc., product name "Dalamar Yellow") was used instead of 0.05 parts of a red pigment, a single substance having a thickness of 50 μm. A yellow pressure-sensitive adhesive sheet having a transmittance of 57.9% was obtained.

<Manufacturing Example 8 Preparation of Green Adhesive Sheet>
0.03 parts of blue pigment (manufactured by Tokyo Chemical Industry Co., Ltd., product name "Pigment Blue 15") and yellow pigment (manufactured by Oakwood Products, Inc., product name "Dalamar Yellow") 0 instead of 0.05 parts of red pigment A green pressure-sensitive adhesive sheet having a thickness of 50 μm and a single permeability of 43.3% was obtained in the same manner as in Production Example 5 except that .03 parts were mixed and used.

<Manufacturing Example 9 Preparation of Light Diffusion Adhesive Sheet>
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a cooler, 94.9 parts of butyl acrylate, 5 parts of acrylic acid, 0.1 part of 4-hydroxybutyl acrylate, and 2, as a polymerization initiator. 0.1 part of 2'-azobisisobutyronitrile was charged together with 100 parts of ethyl acetate (monomer concentration 50%), nitrogen gas was introduced with gentle stirring to replace nitrogen, and then the liquid temperature in the flask was adjusted. The polymerization reaction was carried out at around 55 ° C. for 8 hours to prepare a solution of an acrylic polymer having a weight average molecular weight (Mw) of 2.02 million and Mw / Mn = 3.2. With respect to 100 parts of the solid content of the acrylic polymer solution thus obtained, an isocyanate cross-linking agent (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate L", trimethylolpropane tolylene diisocyanate adduct) 0. 45 parts and 0.1 part of benzoyl polymer (manufactured by Nippon Oil & Fats Co., Ltd., trade name "Niper BMT"), and light diffusing fine particles (manufactured by Momentive Performance Materials, trade name "Tospearl 145", particle size 4. 5 μm) 26 parts were blended to prepare an acrylic light diffusing pressure-sensitive adhesive composition. Next, the acrylic light-diffusing pressure-sensitive adhesive composition was dried on one side of a silicone-treated 38 μm-thick polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., trade name “MRF38”). The pressure-sensitive adhesive layer was applied so as to have a thickness of 23 μm, and dried at 155 ° C. for 1 minute to form a light-diffusing pressure-sensitive adhesive sheet (light-diffusing pressure-sensitive adhesive layer, haze: 80%).

<Manufacturing Example 10 Fabrication of Light Diffusing Element A>
As a resin contained in the light diffusing element, 100 parts by weight of an ultraviolet curable urethane acrylate resin (manufactured by DIC Corporation, trade name "Unidic 17-806", solid content 80%) was prepared. Styrene crosslinked particles (manufactured by Soken Kagaku Co., Ltd., trade name "MX-350H", weight average particle size: 3.5 μm, refractive index 1.59) per 100 parts by weight of the resin solid content of the resin. 14 parts by weight, 2.5 parts by weight of synthetic smectite (manufactured by Kunimine Kogyo Co., Ltd., trade name "Smecton SAN") having an organic viscosity as a thixotropy-imparting agent, photopolymerization initiator (manufactured by BASF, trade name "OMNIRAD907") 5 parts by weight and 0.5 part by weight of a leveling agent (manufactured by DIC Co., Ltd., trade name "Megafuck F-556", 100% solid content) were mixed. The light diffusing element forming material (coating liquid) was prepared by diluting this mixture with a mixed solvent of toluene / ethyl acetate (weight ratio 90/10) so that the solid content concentration was 30%.
A light diffusing element forming material (coating liquid) is applied to one side of a triacetyl cellulose (TAC) film (manufactured by Fujifilm, product name "TG60UL", thickness: 60 μm) that can function as a protective layer using a bar coater. , A coating film was formed. Then, the transparent plastic film base material on which this coating film was formed was transported to a drying step. In the drying step, the coating film was dried by heating at 110 ° C. for 1 minute. Then, an ultraviolet ray having an integrated light amount of 300 mJ / cm ² was irradiated with a high-pressure mercury lamp, and the coating film was cured to form a light diffusing element A having a thickness of 5.0 μm on one side of the TAC film. The haze value of the light diffusing element A was 42%.

<Manufacturing Example 11 Fabrication of Light Diffusing Element B>
As light diffusing fine particles, 14 parts by weight of amorphous silica (manufactured by Fuji Silysia Chemical Ltd., trade name "Silohobic 100", weight average particle size: 2.6 μm) was added, and the thickness after curing treatment was increased to 7. The light diffusing element B was formed on one side of the TAC film by the same method as in Production Example 10 except that the thickness was set to 0 μm. The haze value of the light diffusing element B was 11%.

[Example 1]
Reflective polarizing element (manufactured by Nitto Denko Co., Ltd., product name "APCF", single transmittance:) on the surface of the iodine-based polarizing element of the polarizing plate A obtained in Production Example 1 via an acrylic pressure-sensitive adhesive layer (thickness: 23 μm). 47%) was laminated to obtain a laminate having a structure of a protective layer / iodine-based polarizer / reflective polarizer. At this time, the reflection axis of the reflective polarizer and the absorption axis of the iodine-based polarizer were laminated so as to be parallel to each other. The red adhesive sheet (thickness: 50 μm, single transmittance: 19.3%) obtained in Production Example 5 was applied to the surface of the reflective polarizer of the obtained laminate, and then the light obtained in Production Example 10 was applied. A TAC film having a diffusing element A on one surface was bonded so that the TAC film was on the red adhesive sheet side to obtain an optical laminate 1.

[Example 2]
An optical laminate in the same manner as in Example 1 except that the blue adhesive sheet (thickness: 50 μm, single transmittance: 24.2%) obtained in Production Example 6 was used instead of the red adhesive sheet. I got 2.

[Example 3]
An optical laminate in the same manner as in Example 1 except that the yellow adhesive sheet (thickness: 50 μm, single transmittance: 57.9%) obtained in Production Example 7 was used instead of the red adhesive sheet. I got 3.

[Example 4]
An optical laminate in the same manner as in Example 1 except that the green adhesive sheet (thickness: 50 μm, single transmittance: 43.3%) obtained in Production Example 8 was used instead of the red adhesive sheet. I got 4.

[Example 5]
Example 1 except that a TAC film having the light diffusing element B obtained in Production Example 11 on one surface was used instead of the TAC film having the light diffusing element A obtained in Production Example 10 on one surface. In the same manner as above, an optical laminate 5 was obtained.

[Example 6]
In the same manner as in Example 1, a laminate having a protective layer / iodine-based polarizer / reflective polarizer configuration was obtained. The red pressure-sensitive adhesive sheet (thickness: 50 μm, single transmittance: 19.3%) obtained in Production Example 5 and the light-diffusing pressure-sensitive adhesive obtained in Production Example 9 were placed on the surface of the reflective polarizer of the obtained laminate. Sheets (thickness: 23 μm, haze value: 80%) are bonded in this order, and then a TAC film (manufactured by Fujifilm, product name “TG60UL”, thickness: 60 μm) is bonded to the surface of the light-diffusing adhesive sheet. The optical laminate 6 was obtained.

[Example 7]
An optical laminate in the same manner as in Example 6 except that the blue adhesive sheet (thickness: 50 μm, single transmittance: 24.2%) obtained in Production Example 6 was used instead of the red adhesive sheet. I got 7.

[Example 8]
An optical laminate in the same manner as in Example 6 except that the yellow adhesive sheet (thickness: 50 μm, single transmittance: 57.9%) obtained in Production Example 7 was used instead of the red adhesive sheet. I got 8.

[Example 9]
An optical laminate in the same manner as in Example 6 except that the green adhesive sheet (thickness: 50 μm, single transmittance: 43.3%) obtained in Production Example 8 was used instead of the red adhesive sheet. I got 9.

[Example 10]
In the same manner as in Example 1, a laminate having a protective layer / iodine-based polarizer / reflective polarizer configuration was obtained. The red polarizer obtained in Production Example 2 was laminated on the surface of the reflective polarizer of the obtained laminate via an acrylic pressure-sensitive adhesive layer (thickness: 23 μm). At this time, the reflection axis of the reflective polarizer and the absorption axis of the red polarizer were bonded so as to be parallel to each other. Next, a TAC film having the light diffusing element A obtained in Production Example 10 on one surface is provided on the surface of the red polarizing element via an acrylic pressure-sensitive adhesive layer (thickness: 23 μm), and the TAC film is on the pressure-sensitive adhesive layer side. The optical laminate 10 was obtained by laminating them so as to be.

[Example 11]
An optical laminate 11 was obtained in the same manner as in Example 10 except that the blue polarizer obtained in Production Example 3 was used instead of the red polarizer.

[Example 12]
An optical laminate 12 was obtained in the same manner as in Example 10 except that the yellow polarizer obtained in Production Example 4 was used instead of the red polarizer.

[Example 13]
Example 10 except that a TAC film having the light diffusing element B obtained in Production Example 11 on one surface was used instead of the TAC film having the light diffusing element A obtained in Production Example 10 on one surface. In the same manner as above, an optical laminate 13 was obtained.

[Example 14]
In the same manner as in Example 1, a laminate having a protective layer / iodine-based polarizer / reflective polarizer configuration was obtained. The red polarizer obtained in Production Example 2 was laminated on the surface of the reflective polarizer of the obtained laminate via an acrylic pressure-sensitive adhesive layer (thickness: 23 μm). At this time, the reflection axis of the reflective polarizer and the absorption axis of the red polarizer were bonded so as to be parallel to each other. Next, on the surface of the red polarizing element, a TAC film (manufactured by Fujifilm, product name "TG60UL", thickness) was passed through the light diffusing adhesive sheet (thickness: 23 μm, haze value: 80%) obtained in Production Example 9. : 60 μm) was laminated to obtain an optical laminate 14.

[Example 15]
An optical laminate 15 was obtained in the same manner as in Example 14 except that the blue polarizer obtained in Production Example 3 was used instead of the red polarizer.

[Example 16]
An optical laminate 16 was obtained in the same manner as in Example 14 except that the yellow polarizer obtained in Production Example 4 was used instead of the red polarizer.

[Comparative Example 1]
In the same manner as in Example 1, a laminate having a protective layer / iodine-based polarizer / reflective polarizer configuration was obtained. A TAC film (manufactured by FUJIFILM Corporation, manufactured by Fujifilm Co., Ltd.) is placed on the surface of the reflective polarizer of the obtained laminate via the red adhesive sheet (thickness: 50 μm, single transmittance: 19.3%) obtained in Production Example 5. The name "TG60UL", thickness: 60 μm) was laminated to obtain an optical laminate C1.

[Comparative Example 2]
In the same manner as in Example 1, a laminate having a protective layer / iodine-based polarizer / reflective polarizer configuration was obtained. The red polarizer obtained in Production Example 2 was laminated on the surface of the reflective polarizer of the obtained laminate via an acrylic pressure-sensitive adhesive layer (thickness: 23 μm). At this time, the reflection axis of the reflective polarizer and the absorption axis of the red polarizer were bonded so as to be parallel to each other. Next, a TAC film (manufactured by FUJIFILM Corporation, product name "TG60UL", thickness: 60 μm) is attached to the surface of the red polarizing element via an acrylic pressure-sensitive adhesive layer (thickness: 23 μm) to form an optical laminate C2. Got

[Comparative Example 3]
An optical laminate C3 was obtained in the same manner as in Comparative Example 2 except that the blue polarizer obtained in Production Example 3 was used instead of the red polarizer.

[Comparative Example 4]
An optical laminate C4 was obtained in the same manner as in Comparative Example 2 except that the yellow polarizer obtained in Production Example 4 was used instead of the red polarizer.

[Comparative Example 5]
The polarizing plate A having the structure of the polarizer / protective layer obtained in Production Example 1 was used as it was as the optical laminate C5.

Table 1 shows the configurations and optical characteristics of the optical laminates obtained in Examples and Comparative Examples.

As is clear from Table 1, the optical laminate of the example has a higher metric saturation of the reflected light than the conventional polarizing plate (Comparative Example 5), and therefore, when the image display device is not displayed (power off). It can be seen that the display screen of (hours) can exhibit a color that is in harmony with the design of the peripheral part. Further, the optical laminate of the example has a suppressed glossiness as compared with the optical laminate of the comparative example having no light diffusion layer, and therefore, it exhibits a metallic opaque gloss and the peripheral portion. It can be seen that a display screen that exhibits a texture that is in harmony with the design can be realized.

The optical laminate and image display device of the present invention can be suitably used, for example, as a display unit for electric appliances such as rice cookers, refrigerators, and microwave ovens, and as a display unit for car navigation systems and instruments in a vehicle interior space.

10 Light-diffusing layer 20 Light-transmitting reflector 30 Absorption-type polarizing element 40 Light-transmitting colored layer 100 Optical laminate

Claims (8)

1. An optical laminate having a light diffusion layer, a light transmissive reflector, and an absorption type polarizer in this order from the visual side.
2. The optical laminate according to claim 1, which has a light-transmitting colored layer on the visual side of the light-transmissive reflector.
3. It has the light diffusion layer on the outermost surface,
   The optical laminate according to claim 1 or 2, wherein the haze of the light diffusion layer is 5% or more.
4. It has a protective layer on the outermost surface
   The optical laminate according to claim 1 or 2, wherein the haze of the light diffusion layer is 5% or more.
5. The optical laminate according to any one of claims 1 to 4, wherein the light-transmitting reflector has a single transmittance of 10% to 70%.
6. The optical laminate according to any one of claims 1 to 5, wherein the light-transmitting reflector includes a reflective polarizing element.
7. The optical laminate according to claim 6, wherein the reflection axis direction of the reflective polarizer and the absorption axis direction of the absorption polarizer are arranged so as to be substantially parallel to each other.
8. An image display device comprising the optical laminate according to any one of claims 1 to 7.

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