JP2023072971A - Optical multilayer body and image display device - Google Patents

Abstract

To provide an image display device comprising a colored part provided along the outer periphery of a display screen, making inconspicuous a difference in outer appearance between a display area and a non-display area with the display switched off.SOLUTION: The present invention provides: an optical multilayer body which sequentially comprises, in the following order, a polarizing plate that comprises a polarizer, a print layer that is provided along the outer periphery of the polarizing plate, and a first adhesive layer that contains a colorant; and an image display device which sequentially comprises a display element and the optical multilayer body in this order toward the viewing side, wherein the optical multilayer body is arranged in such a manner that the print layer is closer to the viewing side than the polarizing plate.SELECTED DRAWING: Figure 2A

Description

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

In recent years, automobiles are equipped with displays for various purposes such as various instrument displays, car navigation, back monitors, audio visuals, and the like. In such in-vehicle displays, in general, for the purpose of harmonizing the appearance with the frame member of the display itself, the surrounding members such as the instrument panel and console, and shielding wiring, terminals, etc., the display screen is covered. A colored portion is provided along the outer periphery to form a display area and a non-display area. Moreover, in tablet terminals for general use or business use, a colored portion is often provided along the outer peripheral portion of the display screen.

In an image display device in which a colored portion is provided along the outer periphery of the display screen, the difference in appearance between the display area (black screen) and the non-display area (colored portion) is conspicuous when the display is not displayed (when the power is turned off). In some cases, improvements are required from the viewpoint of designability.

In relation to the above demand, Patent Document 1 proposes a display body in which the color difference between the display area and the non-display area is reduced when the display is not displayed, but there is a demand for further improvement.

Japanese Patent Application Laid-Open No. 2020-192708

The present invention has been made to solve the above problems, and its main object is to provide an image display device in which a colored portion is provided along the outer periphery of the display screen, and a display area and a display area when not displaying. To provide an image display device in which the difference in appearance from a non-display area is difficult to recognize.

According to one aspect of the present invention, a polarizing plate containing a polarizer, a printed layer provided along the outer periphery of the polarizing plate, and a first adhesive layer containing a coloring material are provided in this order. , an optical stack is provided.
In one embodiment, the first adhesive layer has a total light transmittance of 10% to 90%.
In one embodiment, the first pressure-sensitive adhesive layer has a haze of more than 1.0% and 10.0% or less.
In one embodiment, the printing layer has a thickness of 3 μm to 30 μm.
In one embodiment, the polarizing plate has a second pressure-sensitive adhesive layer on the opposite side of the printed layer.
In one embodiment, it has a surface substrate layer on the side opposite to the side on which the printed layer of the first pressure-sensitive adhesive layer is arranged.
In one embodiment, the first pressure-sensitive adhesive layer has a release liner on the side opposite to the side on which the printed layer is arranged.
According to one aspect of the present invention, the display element and the optical layered body are provided in this order toward the viewing side, and the optical layered body is arranged such that the printed layer is on the viewing side of the polarizing plate. An image display device is provided, which is arranged in a
In one embodiment, the SCI method L*a*b* color difference (CIE 1976 ) is less than 2.0.
In one embodiment, the display element comprises a liquid crystal cell, an organic electronic element or an inorganic electronic element.
In one embodiment, the display element further includes a touch panel.

An image display device according to an embodiment of the present invention has a structure in which a display element, a polarizer, a printed layer constituting a non-display area, and an adhesive layer containing a coloring material are arranged in this order toward the viewing side. have. By adopting such a configuration, it is possible to make it difficult to recognize the difference in appearance between the display area and the non-display area when not displaying.

(a) is a schematic cross-sectional view of an optical layered body according to one embodiment of the present invention, and (b) is a schematic top view of the optical layered body shown in (a). 1 is a schematic cross-sectional view of an optical stack according to one embodiment of the invention; FIG. 1 is a schematic cross-sectional view of an optical stack according to one embodiment of the invention; FIG. 1 is a schematic cross-sectional view of an optical stack according to one embodiment of the invention; FIG. 1 is a schematic cross-sectional view of an image display device according to one embodiment of the present invention; FIG. 1 is a schematic cross-sectional view of an image display device according to one embodiment of the present invention; FIG. 1 is a schematic cross-sectional view of an image display device according to one embodiment of the present invention; FIG.

Preferred embodiments of the present invention will be described below, but the present invention is not limited to these embodiments. In this specification, "-" representing a numerical range includes its upper and lower limits.

A. Optical Layered Body An optical layered body according to an embodiment of the present invention includes a polarizing plate containing a polarizer, a printed layer provided along the outer peripheral portion of the polarizing plate, a first adhesive layer containing a coloring material, in this order. The optical laminate is preferably used for producing an image display device. At this time, a first layer containing a coloring material is placed on the viewing side of a display element such as an organic electroluminescence (EL) element, an inorganic EL element, or a liquid crystal cell. is arranged so that the pressure-sensitive adhesive layer of is on the viewing side of the printed layer. By arranging the first pressure-sensitive adhesive layer containing the coloring material on the viewing side of the printed layer, the reflected light from the display area and the non-display area on the display screen of the image display device when not displaying is appropriately absorbed and By diffusing, the color difference and reflectance difference between the display area and the non-display area can be reduced. In the following description, making it difficult to recognize the difference in appearance between the display area and the non-display area (making it less noticeable) may be referred to as "making the display area and the non-display area seamless."

A-1. Overall Configuration of Optical Layered Body FIG. 1A is a schematic cross-sectional view (a) and a schematic top view (b) of an optical layered body according to one embodiment of the present invention. The optical layered body 100a shown in FIG. 1A has a polarizing plate 10 containing a polarizer 12, a printed layer 20, and a first adhesive layer 30 containing a coloring material in this order. As shown in FIG. 1(b), the printed layer 20 is provided in a frame shape along the outer peripheral portion on the main surface of the polarizing plate 10, and the optical layered body 100a is arranged on the display element. When an image display device is configured, the portion where the print layer 20 is not provided (in other words, the portion surrounded by the print layer 20) becomes the display area A, and the portion where the print layer 20 is provided is non-display. area B.

1B-1D are each schematic cross-sectional views of optical stacks according to one embodiment of the present invention. The optical layered body 100b shown in FIG. 1B further has a second adhesive layer 40 on the opposite side of the polarizing plate 10 to the printed layer 20 side. The second pressure-sensitive adhesive layer 40 is typically used to bond the optical laminate to adjacent members such as display elements.

In addition to the second adhesive layer 40, the optical laminate 100c shown in FIG. It has release liners 50a, 50b, respectively, on the side opposite to the side on which layer 20 is located.

An optical laminate 100d shown in FIG. 1D includes a surface base layer 60 on the side of the first pressure-sensitive adhesive layer 30 opposite to the side on which the printed layer 20 is arranged, in addition to the second pressure-sensitive adhesive layer 40 and the release liner 50a. have

The optical layered body according to the embodiment of the present invention is not limited to the configuration of the illustrated example. For example, each embodiment can be combined as appropriate. In addition, the optical layered body may further have any appropriate component depending on the purpose. Such components include, for example, a retardation layer and a surface protection film. Each component may be laminated via any appropriate adhesive layer (adhesive layer, adhesive layer, etc.) as necessary.

The total light transmittance of the display area of the optical laminate is, for example, 15.0% or more, preferably 20.0% to 45%, more preferably 40% to 45%.

The reflectance (SCI method) of the non-display area of the optical laminate is, for example, less than 10%, preferably 1.0% to 10%, more preferably 1.0% to 5.0%. The reflectance of the display area (SCI method) is, for example, less than 10%, preferably 1.0% to 10%, more preferably 1.0% to 5.0%. When the optical laminate includes a surface substrate layer (for example, a surface substrate layer having an antireflection layer), the reflectance (SCI method) of the non-display area of the optical laminate is, for example, less than 2.5%, preferably may be between 0.5% and 2.0%, more preferably between 0.5% and 1.0%. The reflectivity of the display area (SCI method) can be, for example, less than 2.5%, preferably 0.5% to 2.0%, more preferably 0.5% to 1.0%.

The reflectance (SCE method) of the non-display area of the optical layered body is, for example, less than 1.5%, preferably 0.1% to 1.0%, more preferably 0.1% to 0.5%. The reflectance of the display area (SCE method) is, for example, less than 1.5%, preferably 0.1% to 1.0%, more preferably 0.1% to 0.5%.

The thickness of the optical layered body is, for example, 100 μm to 4000 μm, preferably 200 μm to 2000 μm.

A-2. Polarizing Plate A polarizing plate includes a polarizer, and typically includes a polarizer and a protective layer provided on one side or both sides thereof.

A-2-1. Polarizer A polarizer is typically composed of a polyvinyl alcohol-based resin film containing a dichroic substance (eg, iodine). The polarizer may be composed of a single-layer resin film, or may be manufactured using 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 polyvinyl alcohol (PVA) films, partially formalized PVA films, and partially saponified ethylene/vinyl acetate copolymer films. In addition, polyene-based oriented films such as those subjected to dyeing treatment and stretching treatment with dichroic substances such as iodine and dichroic dyes, and dehydrated PVA and dehydrochlorinated polyvinyl chloride films. A polarizer obtained by dyeing a PVA-based film with iodine and uniaxially stretching the film is preferably used because of its excellent optical properties.

The dyeing with iodine is performed by, for example, immersing the PVA-based film in an aqueous iodine solution. The draw ratio of the uniaxial drawing 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 swelling treatment, cross-linking treatment, washing treatment, drying treatment, and the like. For example, by immersing the PVA-based film in water and washing it with water before dyeing, it is possible not only to wash away stains and anti-blocking agents on the surface of the PVA-based film, but also to swell the PVA-based film to remove uneven dyeing. can be prevented.

Specific examples of the polarizer obtained using a laminate include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a resin substrate and the resin A polarizer obtained by using a laminate with a PVA-based resin layer formed by coating on a substrate can be mentioned. A polarizer obtained by using a laminate of a resin base material and a PVA-based resin layer formed by coating on the resin base material is obtained, for example, by applying a PVA-based resin solution to the resin base material and drying the resin base material. forming a PVA-based resin layer thereon to obtain a laminate of a resin substrate and a PVA-based resin layer; stretching and dyeing the laminate to use the PVA-based resin layer as a polarizer; obtain. In this embodiment, stretching typically includes immersing the laminate in an aqueous boric acid solution and stretching. Furthermore, stretching may further include stretching the laminate in air at a high temperature (eg, 95° C. or higher) before stretching in an aqueous boric acid solution, if necessary. The obtained resin substrate/polarizer laminate may be used as it is (that is, the resin substrate may be used as a protective layer for the polarizer), or the resin substrate may be peeled off from the resin substrate/polarizer laminate. Then, any appropriate protective layer may be laminated on the release surface according to the purpose. Details of a method for manufacturing such a polarizer are described, for example, in Japanese Patent Application Laid-Open No. 2012-73580. The publication is incorporated herein by reference in its entirety.

The thickness of the polarizer is, for example, 30 μm or less, preferably 15 μm or less, more preferably 1 μm to 12 μm, even more preferably 2 μm to 10 μm, still more preferably 2 μm to 8 μm.

The polarizer preferably exhibits absorption dichroism at any wavelength of 380 nm to 780 nm. The single transmittance of the polarizer is, for example, 41.0% or more, preferably 43.0% to 46.0%, and more preferably 44.5% to 46.0%. The degree of polarization of the polarizer is preferably 97.0% or higher, more preferably 99.0% or higher, still more preferably 99.9% or higher.

A-2-2. Protective Layer The protective layer is composed of any suitable film that can be used as a protective layer for a polarizer. Specific examples of materials that are the main component of the film include cellulose resins such as triacetyl cellulose (TAC), polyesters, polyvinyl alcohols, polycarbonates, polyamides, polyimides, polyethersulfones, and polysulfones. , polystyrene-based, polynorbornene-based, polyolefin-based, (meth)acrylic-based, and acetate-based transparent resins. Thermosetting resins such as (meth)acrylic, urethane, (meth)acrylic urethane, epoxy, and silicone, or ultraviolet curable resins may also be used. In addition, for example, a glassy polymer such as a siloxane-based polymer can also be used. Further, polymer films described in JP-A-2001-343529 (WO01/37007) can also be used. Materials for this film include, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in a side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and nitrile group in a side chain. can be used, for example, a resin composition comprising an alternating copolymer of isobutene and N-methylmaleimide and an acrylonitrile/styrene copolymer. The polymer film can be, for example, an extrudate of the resin composition.

When the polarizing plate is applied to an image display device, the protective layer (outer protective layer) disposed on the side opposite to the display element typically has a thickness of 300 µm or less, preferably 100 µm or less, and more preferably 5 µm. ~80 μm, more preferably 10 μm to 60 μm. In addition, when the surface treatment is performed, the thickness of the outer protective layer is the thickness including the thickness of the surface treatment layer.

The thickness of the protective layer (inner protective layer) disposed on the display element side when the polarizing plate is applied to an image display device is preferably 5 μm to 200 μm, more preferably 10 μm to 100 μm, and still more preferably 10 μm to 60 μm. .

In one embodiment, the inner protective layer is optically isotropic. As used herein, “optically isotropic” means that the in-plane retardation Re (550) of the retardation layer is 0 nm to 10 nm, and the thickness direction retardation Rth (550) is −10 nm to +10 nm. It means that In another embodiment, the inner protective layer is a retardation layer that is optically anisotropic and has any suitable retardation value. The in-plane retardation Re(550) of the retardation layer is, for example, 120 nm to 160 nm, preferably 135 nm to 155 nm. In this case, the inner protective layer is a λ / 4 plate, the angle formed by the slow axis direction and the absorption axis direction of the polarizer is, for example, 45 ° ± 10 °, preferably 45 ° ± 5 °, more preferably A circularly polarizing plate can be obtained by arranging them at an angle of 45°. Here, “Re(550)” is an in-plane retardation measured with light having a wavelength of 550 nm at 23° C., and is obtained by the formula: Re=(nx−ny)×d. "Rth(550)" is the retardation in the thickness direction measured with light having a wavelength of 550 nm at 23° C., and is obtained by the formula: Rth(λ)=(nx−nz)×d. Here, “nx” is the refractive index in the direction in which the in-plane refractive index is maximized (that is, the slow axis direction), and “ny” is the in-plane direction orthogonal to the slow axis (that is, the fast is the refractive index in the axial direction), 'nz' is the refractive index in the thickness direction, and 'd' is the layer (film) thickness (nm).

A-3. Printed Layer The printed layer is a colored layer colored by printing according to the application and desired design. The printed layer may be a design layer having a predetermined design, or may be a solid colored layer. The printed layer is preferably a solid colored layer, and more preferably dark colors such as black, blue, navy blue, purple, and brown (for example, L* in the SCI system L*a*b* color space is 50 or less, a* value of +10 to −10 and b* value of +10 to −10), more preferably black (for example, L* in L*a*b* color space of SCI system is 20 or less). , an a* value of +5 to −5 and a b* value of +5 to −5). By using a black colored layer as the printed layer, the wiring, terminals, backlight, and other parts can be suitably hidden in the non-display area.

The printed layer can be formed in any suitable pattern depending on the purpose. Typically, the printed layer is formed on the main surface of the polarizing plate in a frame-like shape along the outer periphery thereof, and can be formed, for example, at a position corresponding to the bezel. With such a configuration, the non-display area can be hidden without using a bezel.

The printed layer can be formed by any appropriate printing method using the printed layer forming composition. Specific examples of printing methods include gravure printing, offset printing, silk screen printing, and transfer printing from a transfer sheet.

The print layer-forming composition typically contains a binder, a coloring material, a solvent, and any appropriate additive that can be used as necessary. Binders include chlorinated polyolefins (eg, chlorinated polyethylene, chlorinated polypropylene), polyester resins, urethane resins, acrylic resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymers, and cellulose resins. . Binder resin may be used independently and may use 2 or more types together. In one embodiment, the binder resin is a thermopolymerizable resin. Since the thermal polymerizable resin can be used in a smaller amount than the photopolymerizable resin, it is possible to increase the amount of the colorant used (colorant content in the colored layer). As a result, particularly in the case of forming a black colored layer, a colored layer having a very small total light transmittance and excellent hiding power can be formed. In one embodiment, the binder resin is a (meth)acrylic resin, preferably a (meth)acrylic resin containing a polyfunctional monomer (eg, pentaerythritol tri(meth)acrylate) as a copolymerization component. By using a (meth)acrylic resin containing a polyfunctional monomer as a copolymerization component, a print layer having an appropriate elastic modulus can be formed. In addition, a step is also formed due to the thickness of the printed layer, and the step can effectively function to prevent blocking.

Any appropriate coloring material can be used as the coloring material depending on the purpose and desired color. The coloring material may be a pigment or a dye, preferably a pigment. Specific examples of the coloring material include inorganic pigments such as titanium white, zinc white, carbon black, iron black, red iron oxide, chrome vermilion, ultramarine blue, cobalt blue, yellow lead, titanium yellow; phthalocyanine blue, indanthrene blue, iso Organic pigments or dyes such as indolinone yellow, benzidine yellow, quinacridone red, polyazo red, perylene red, aniline black; metal pigments consisting of scale-like foils such as aluminum and brass; scales such as titanium dioxide-coated mica and basic lead carbonate Pearl luster pigments (pearl pigments) consisting of shaped foil pieces can be mentioned. When forming a black colored layer, carbon black, iron black, and aniline black are preferably used. In this case, it is preferable to use a coloring material together. This is because it can absorb visible light in a wide range and evenly, and can form a colorless (that is, pitch black) colored layer. For example, an azo compound and/or a quinone compound may be used in addition to the coloring materials described above. In one embodiment, the colorant contains carbon black as a main component and another colorant (eg, an azo compound and/or a quinone compound). According to such a configuration, it is possible to form a colored layer that is free from coloring and has excellent stability over time. When forming a black colored layer, the coloring material may be used in a proportion of preferably 50 to 200 parts by weight with respect to 100 parts by weight of the binder resin. In this case, the content of carbon black in the coloring material is preferably 80% to 100%. By using a coloring material (especially carbon black) in such a ratio, a colored layer having a very low total light transmittance and excellent stability over time can be formed.

The total light transmittance of the print layer is preferably 0.01% or less, more preferably 0.008% or less. If the total light transmittance is within such a range, the non-display area of the image display device can be satisfactorily concealed.

The thickness of the printed layer is, for example, 3 μm to 30 μm, preferably 5 μm to 20 μm, more preferably 10 μm to 15 μm. If the thickness of the printed layer is within this range, the seamless effect between the display area and the non-display area can be preferably obtained.

A-4. First Adhesive Layer The first adhesive layer is formed from an adhesive composition containing a coloring material. The first pressure-sensitive adhesive layer containing a coloring material moderately absorbs and diffuses reflected light in the display area and the non-display area. display area can be made seamless.

The total light transmittance of the first adhesive layer is preferably 10% to 90%, more preferably 30% to 85%, still more preferably 50% to 80%. If the total light transmittance of the first pressure-sensitive adhesive layer is within this range, the seamless effect between the display area and the non-display area can be obtained while ensuring a practically acceptable luminance when applied to an image display device. can be obtained.

The haze of the first pressure-sensitive adhesive layer is preferably more than 1.0% and 10.0% or less, more preferably 1.1% to 5.0%, still more preferably 1.2% to 3.0%, Even more preferably 1.2% to 2.8%. If the haze of the first pressure-sensitive adhesive layer is within this range, it is suitable for making the display area and the non-display area seamless.

Any appropriate pressure-sensitive adhesive composition can be used as the pressure-sensitive adhesive composition. 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 adhesive compositions. Among them, an acrylic pressure-sensitive adhesive composition is preferably used because of its excellent adhesive properties, weather resistance, heat resistance, and the like.

The acrylic pressure-sensitive adhesive composition contains, as a base polymer, a partial polymer of a 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 the ester end. Alkyl (meth)acrylate can be used individually by 1 type or in combination of 2 or more types. In this specification, "(meth)acrylate" means acrylate and/or methacrylate.

Examples of the alkyl (meth)acrylates include branched alkyl (meth)acrylates having 4 to 9 carbon atoms. The alkyl (meth)acrylate is preferable in that 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, etc., and these may be used alone or in combination of two or more. be able to.

The alkyl (meth)acrylate having an alkyl group having 1 to 24 carbon atoms at the ester end is preferably 40% by weight or more with respect to the total amount of the monofunctional monomer component forming the (meth)acrylic polymer, 50% by weight or more is more preferable, and 60% by weight or more is even more preferable.

The monomer component includes, as a monofunctional monomer component, a copolymerizable monomer other than the alkyl (meth)acrylate (e.g., carboxyl group-containing monomer, hydroxyl group-containing monomer, amide group-containing monomer, aromatic ring-containing (meth)acrylate, etc.). ). A copolymerizable monomer can be used as the remainder of the alkyl (meth)acrylate in the monomer component.

The copolymerization monomer and the amount used thereof are described in paragraphs 0029 to 0042 of JP-A-2016-157077 and the amount thereof used, or paragraphs 0022-0036 of JP-A-2016-190996. of copolymerized monomers and amounts used thereof can be applied.

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

Polyfunctional monomers are monomers having at least two polymerizable functional groups having unsaturated double bonds such as (meth)acryloyl groups or vinyl groups, 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, tetramethylolmethane tri(meth)acrylate, etc. Ester compounds of polyhydric alcohol 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, etc. is mentioned. Among these, trimethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, and dipentaerythritol hexa(meth)acrylate can be preferably used. A polyfunctional monomer can be used individually by 1 type or in combination of 2 or more types.

The amount of the polyfunctional monomer used varies depending on its molecular weight, the number of functional groups, etc., but it is preferably used in an amount of 3 parts by weight or less, more preferably 2 parts by weight or less, with respect to a total of 100 parts by weight of the monofunctional monomers. 1 part by weight or less is more preferable. Although the lower limit is not particularly limited, it is preferably 0 parts by weight or more, more preferably 0.001 parts by weight or more. By setting the amount of the polyfunctional monomer to be used within the above range, the adhesive strength can be improved.

The (meth)acrylic polymer has a weight average molecular weight of, for example, 1,000,000 to 2,500,000, preferably 1,200,000 to 2,000,000. Further, the molecular weight distribution (weight average molecular weight (Mw)/number average molecular weight (Mn)) is preferably 1.8 or more and 10 or less, more preferably 1.8 to 7, 1.8 to 5 is more preferable. The weight average molecular weight and molecular weight distribution (Mw/Mn) are measured by GPC (gel permeation chromatography) and obtained from values calculated by polystyrene conversion.

The (meth)acrylic polymer can be produced by any appropriate method. For example, radical polymerization methods such as solution polymerization, radiation polymerization such as ultraviolet (UV) polymerization, bulk polymerization, and 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 generally about 50-80° C., and the reaction time is 1-8 hours. Moreover, among the above production methods, the solution polymerization method is preferable, and ethyl acetate, toluene, etc. are generally used as the solvent for the (meth)acrylic polymer. The solution concentration is usually about 20 to 80% by weight. The (meth)acrylic polymer to be obtained may be any of random copolymers, block copolymers, graft copolymers, and the like.

The pressure-sensitive adhesive composition can contain a cross-linking agent. Examples of cross-linking agents include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, silicone-based cross-linking agents, oxazoline-based cross-linking agents, aziridine-based cross-linking agents, silane-based cross-linking agents, alkyl-etherified melamine-based cross-linking agents, metal chelate-based cross-linking agents, oxides and the like. The cross-linking agents can be used singly or in combination of two or more. Among these, isocyanate-based cross-linking agents are preferably used.

The mixing ratio of the (meth)acrylic polymer and the cross-linking agent is usually about 0.001 to 20 parts by weight of the cross-linking agent (solid content) per 100 parts by weight of the (meth)acrylic polymer (solid content). is preferred, and about 0.01 to 15 parts by weight is more preferred.

Any appropriate coloring material may be used as the coloring material depending on the hue of the printed layer. The coloring material may be a pigment or a dye, preferably a pigment. The total light transmittance and haze of the first pressure-sensitive adhesive layer can be adjusted to desired values by adjusting the particle size and content of the pigment.

Specific examples of the pigment include the coloring materials exemplified for the printed layer, and preferably the same coloring materials as those blended in the composition for forming the printed layer can be used. In one embodiment, when the printed layer is a black colored layer, a black colorant such as carbon black, iron black, or aniline black may optionally be added to other colorants (e.g., azo compounds and/or quinone compounds). The first pressure-sensitive adhesive layer when the printed layer is a black colored layer, for example, in the L*a*b* color space, L* is 90 or less, a* value is +10 to -10, b* value is It may have a transmission color of +10 to -10, preferably an L* of 90 or less, an a* value of -5 to +5, and a b* value of -5 to +5.

The average particle size of the coloring material can be, for example, 0.05 μm to 5 μm, preferably 0.1 μm to 3 μm, more preferably 0.15 μm to 1 μm. If the average particle size of the coloring material is within the above range, a pressure-sensitive adhesive layer having suitable haze and total light transmittance can be obtained. In addition, the said average particle diameter is a value calculated|required by a dynamic-light-scattering method.

The amount of the coloring material is, for example, 0.01 parts by weight or more, preferably 0.03 parts by weight or more, and more preferably 0.06 parts by weight or more with respect to 100 parts by weight of the (meth)acrylic polymer (solid content). is. If the blending amount of the coloring material is within the above range, an excellent seamless effect can be obtained. Further, the upper limit of the amount of the coloring material to be blended may be 3.0 parts by weight or less with respect to 100 parts by weight of the (meth)acrylic polymer (solid content) from the viewpoint of ensuring the brightness of the image display device. It can be 0.2 parts by weight or less, or, for example, 0.12 parts by weight or less.

The above-mentioned pressure-sensitive adhesive composition may optionally contain an ultraviolet absorber; a tackifier such as a rosin derivative resin, a polyterpene resin, a petroleum resin, or an oil-soluble phenol resin; a plasticizer; a filler such as a hollow glass balloon; antioxidants; anti-aging agents; silane coupling agents, and other various additives. The amount of additive used can be appropriately set according to 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 to 100 parts by weight of the monofunctional monomer component forming the (meth)acrylic polymer. 1 part by weight, more preferably 0.02 to 0.6 parts by weight.

The pressure-sensitive adhesive composition is preferably adjusted to have a viscosity suitable for application work. Viscosity can be adjusted by adding a thickening polymer, a polyfunctional monomer, or the like, by partially polymerizing the monomer component in the pressure-sensitive adhesive composition, or the like. The partial polymerization may be performed before the addition of the viscosity-increasing polymer, the polyfunctional monomer, or the like, or may be performed after the addition. Since the viscosity of the pressure-sensitive adhesive composition may vary depending on the composition of the monomer components, the types and amounts of additives, etc., it is difficult to unambiguously determine a preferable polymerization rate for partial polymerization, but the polymerization rate is For example, it can be about 20% or less, preferably about 3% to 20%, more preferably about 5% to 15%. If the polymerization rate in the partial polymerization exceeds 20%, the viscosity becomes too high, making it difficult to apply to the substrate.

The pressure-sensitive adhesive layer is formed by applying the above-described pressure-sensitive adhesive composition to various substrates and, if necessary, performing drying, radiation irradiation, and the like. 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 for use.

The thickness of the first adhesive layer (thickness in the display area) is, for example, 50 μm to 1000 μm, preferably 200 μm to 750 μm, more preferably 250 μm to 500 μm.

A-5. Second Pressure-sensitive Adhesive Layer As the pressure-sensitive adhesive composition forming the second pressure-sensitive adhesive layer, any suitable pressure-sensitive adhesive composition applicable to optical applications can be used. The total light transmittance of the second pressure-sensitive adhesive layer is preferably 85% or higher, more preferably 88% or higher. Also, the haze of the second pressure-sensitive adhesive layer is preferably 1.0% or less, more preferably 0.8% or less.

Any appropriate pressure-sensitive adhesive composition can be used as the pressure-sensitive adhesive composition. 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 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. Such an acrylic pressure-sensitive adhesive composition is the same as the pressure-sensitive adhesive composition described in Section A-4 as the pressure-sensitive adhesive composition for forming the first pressure-sensitive adhesive layer, except that it does not contain a coloring material. can be used.

The thickness of the second adhesive layer can be, for example, 1 μm to 150 μm, preferably 5 μm to 100 μm, more preferably 10 μm to 50 μm.

A-6. Surface Base Material Layer The surface base material layer can function as a front plate of an image display device. The surface substrate layer includes a substrate film and, if necessary, may further include functional layers such as an antireflection layer, an antifouling layer, and a hard coat layer. The surface substrate layer preferably includes an antireflection layer. As the antireflection layer, for example, a thin layer type that prevents reflection by utilizing the effect of canceling reflected light due to the interference of light as disclosed in JP-A-2005-248173, JP-A-2011-2759. and a surface structure type that develops a low reflectance by imparting a fine structure to the surface disclosed in . The functional layer can be used singly or in combination of two or more. The functional layer may be laminated on the base film via an adhesive layer (e.g., adhesive layer, adhesive layer) while being formed on the support film as necessary, or may be laminated without the adhesive layer. It may be formed directly on the base film.

A glass film or a resin film can be used as the base film.

Examples of glass constituting the glass film include soda-lime glass, boric acid glass, aluminosilicate glass, and quartz glass according to classification according to composition. Further, according to the classification by alkali component, for example, non-alkali glass and low-alkali glass can be mentioned. The thickness of the glass film is preferably 100 μm to 2000 μm, more preferably 200 μm to 1000 μm.

Resins constituting resin films include polyethylene terephthalate-based resins, polyethylene naphthalate-based resins, acetate-based resins, polyethersulfone-based resins, polycarbonate-based resins, polyamide-based resins, polyimide-based resins, polyamide-imide-based resins, and polyolefin-based resins. , (meth)acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, polyphenylene sulfide resins, and the like. Among them, preferred are polyamide-based resins, polyimide-based resins, polyamideimide-based resins, polyethylene naphthalate-based resins, and polycarbonate-based resins, and more preferred are polyimide-based resins. These resins may be used alone or in combination of two or more. The thickness of the resin film is preferably 100 μm to 2000 μm, more preferably 200 μm to 1000 μm.

A-7. Release liner The release liner is, for example, a plastic (e.g., polyethylene terephthalate (PET), polyethylene, polypropylene) film surface-coated with a release agent such as a silicone-based release agent, a fluorine-based release agent, or a long-chain alkyl acrylate-based release agent. , non-woven fabric or paper. The thickness of the release liner is, for example, 10 μm to 100 μm.

A-8. Other Components The surface protective film includes a substrate and an adhesive layer provided on one side of the substrate. The surface protective film is provided to prevent the surface of the optical layered body (for example, the surface of the surface substrate layer) from being scratched or soiled, and is usually peeled off before use.

As the retardation layer, a retardation layer that functions as a λ/4 plate is preferably used. A retardation layer functioning as a λ/4 plate has an in-plane retardation Re(550) of, for example, 120 nm to 160 nm, preferably 135 nm to 155 nm. Further, the retardation layer functioning as a λ / 4 plate, the slow axis direction and the absorption axis direction of the polarizing plate (polarizer), for example 45 ° ± 10 °, preferably 45 ° ± 5 °, more preferably 45 It can be arranged on the back side of the polarizing plate (the side opposite to the viewing side) so as to form an angle of .degree. With this structure, an excellent circularly polarized light function can be exhibited, and an antireflection function can be exhibited when used in combination with an organic EL element, for example.

A retardation layer functioning as a λ/2 plate may be arranged between the polarizing plate and the retardation layer functioning as a λ/4 plate. In this case, the angle formed by the absorption axis of the polarizing plate (polarizer) and the slow axis of the λ/4 plate is preferably 65° to 85°, more preferably 72° to 78°, further preferably is approximately 75°. The angle formed by the absorption axis of the polarizing plate (polarizer) and the slow axis of the λ/2 plate is preferably 10° to 20°, more preferably 13° to 17°, more preferably about 15 °. A retardation layer functioning as a λ/2 plate has an in-plane retardation Re(550) of, for example, 210 nm to 280 nm, preferably 230 nm to 240 nm.

The retardation layer is typically arranged between the polarizing plate and the second pressure-sensitive adhesive layer via an adhesive layer.

B. Image display device An image display device according to an embodiment of the present invention includes a display element and the optical layered body described in Section A in this order toward the viewing side, and the optical layered body has a printed layer that is more than a polarizing plate. are arranged so as to be on the viewing side. In other words, the image display device according to the embodiment of the present invention includes a display element, a polarizing plate, a printed layer provided along the outer periphery of the polarizing plate, and a first adhesive layer containing a coloring material. , are provided in this order toward the viewing side. The image display device having such a configuration has a display area (an area in which the printed layer is not provided in a plan view) and a non-display area (an area in which the printed layer is provided in the plan view) on the display screen when not displaying. Since the difference in appearance is small, it can be excellent in design.

In the SCI L*a*b* color space of the display area on the display screen when not displaying, for example, L* is preferably 15 or less, more preferably 10 or less, a* is preferably −10 to +10, It is more preferably -5 to +5, and b* is preferably -10 to +10, more preferably -5 to +5. In addition, in the SCE system L*a*b* color space of the display area on the display screen when not displaying, L* is preferably 10 or less, more preferably 5 or less, and a* is preferably −10 to +10. , more preferably -5 to +5, and b* is preferably -10 to +10, more preferably -5 to +5.

The SCI method L*a*b* color difference (CIE 1976) ΔE*ab between the display area and the non-display area on the display screen when not displaying is preferably less than 2.0, more preferably 1.8 or less. , and more preferably 1.6 or less. In addition, the SCE L*a*b* color difference (CIE 1976) ΔE*ab is preferably less than 4.0, more preferably 3.5 or less, still more preferably 3.0 or less. If ΔE*ab is within the above range, it is difficult to recognize the difference in appearance between the display area and the non-display area on the display screen during non-display. Note that L*a*b* color difference (CIE 1976) ΔE*ab is a value calculated by the following formula (where L* is lightness, a* is chromaticity a*, b* is chromaticity b * represents).
ΔE*ab=[(ΔL*) ² +(Δa*) ² +(Δb*) ² ] ^1/2

The reflectance of the SCI method in the display area of the display screen during non-display is preferably less than 2.5%, more preferably 2.0% or less, and even more preferably 1.5% or less. The reflectance in the non-display area is preferably 2.5% or less, more preferably 2.0% or less, and even more preferably 1.5% or less. The difference in reflectance between the two regions is preferably 0.3% or less, more preferably 0.15% or less.

The reflectance of the SCE system in the display area of the display screen during non-display is preferably 1.0% or less, more preferably 0.5% or less, and still more preferably 0.3% or less. The reflectance in the non-display area is preferably 1.0% or less, more preferably 0.5% or less, and even more preferably 0.3% or less. The difference in reflectance between the two regions is preferably 0.3% or less, more preferably 0.15% or less.

Examples of the display device include a liquid crystal cell, an organic EL device, an inorganic EL device, and the like. Also, the display element may further include a touch panel. Since these display elements are well known to those skilled in the art, detailed description thereof will be omitted.

FIG. 2A is a schematic cross-sectional view of an image display device (liquid crystal display device) including a liquid crystal cell as a display element. The image display device 200a includes a backlight unit 110, a rear-side polarizing plate 120, a liquid crystal cell 130, and an optical layered body 100 in this order toward the viewing side. Preferably, the optical layered body 100 has a second adhesive layer (not shown) and is attached to the liquid crystal cell 130 via the second adhesive layer. In the optical laminate 100, typically, the absorption axis direction of the polarizing plate 10 (polarizer 12) and the absorption axis direction of the rear-side polarizing plate 120 are substantially orthogonal (for example, 90°±5°, preferably 90°±3°), and the polarizing plate 10, the liquid crystal cell 130 and the rear side polarizing plate 120 constitute a liquid crystal panel.

FIG. 2B is a schematic cross-sectional view of an image display device (liquid crystal display device) including a liquid crystal cell and a touch panel as display elements. The image display device 200b includes a backlight unit 110, a rear-side polarizing plate 120, a liquid crystal cell 130, a touch panel 140, and an optical laminate 100 in this order facing the viewing side. The optical laminate 100 is preferably attached to the touch panel 140 via a second adhesive layer (not shown). The optical layered body 100 is arranged such that the absorption axis direction of the polarizing plate (viewing side polarizing plate) 10 and the absorption axis direction of the rear side polarizing plate 120 are substantially perpendicular to each other. In the illustrated example, the touch panel has an on-cell structure, but it may have an in-cell structure.

FIG. 2C is a schematic cross-sectional view of an image display device (organic EL display device) including organic EL elements as display elements. The image display device 200c has the organic EL element 150 and the optical layered body 100 in this order toward the viewing side. The optical laminate 100 has a retardation layer 70 which is a λ/4 plate on the back side of the polarizing plate 10, and the angle between the absorption axis direction of the retardation layer 70 and the absorption axis direction of the polarizer 12 is 45. °. The optical laminate 100 is preferably attached to the organic EL element 150 via a second adhesive layer (not shown).

EXAMPLES The present invention will be specifically described below 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 Measured using a digital gauge (manufactured by Ozaki Seisakusho Co., Ltd., product name “PEACOCK”).
(2) L*a*b* color space, color difference ΔE*ab, and reflectance Using a spectrophotometer (CM-2600d, manufactured by Konica Minolta), the spectral reflectance was measured under the following measurement conditions. *a*b* was determined.
(Measurement condition)
Type of light receiving optical system: SCI (including regular reflection light) or SCE (excluding regular reflection light)
Measurement wavelength range: 360nm-740nm
Light source: D65
Measurement diameter MAV: φ8mm
Further, the color difference (ΔE*ab) was calculated by the following formula.
ΔE*ab=[(ΔL*) ² +(Δa*) ² +(Δb*) ² ] ^1/2
(3) Single transmittance of polarizer, degree of polarization Polarizing plate A (protective layer / polarizer / protective layer) was measured using an ultraviolet-visible near-infrared spectrophotometer (manufactured by JASCO Corporation V-7100). The transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc were defined as Ts, Tp, and Tc of the polarizer, respectively. These Ts, Tp and Tc are Y values measured with a 2-degree field of view (C light source) according to JIS Z8701 and subjected to visibility correction. From the obtained Tp and Tc, the degree of polarization was determined using the following formula.
Degree of polarization (%) = {(Tp-Tc)/(Tp+Tc)} ^1/2 × 100
(4) Total light transmittance A transparent acrylic pressure-sensitive adhesive layer (manufactured by Nitto Denko, thickness 20 μm, total light transmittance of 88% or more, haze 0.8% or less) is provided, and a glass film having a thickness of 1 mm (manufactured by Matsunami Glass Industry Co., Ltd., product name "soda lime glass") is laminated via the acrylic adhesive layer as a measurement sample. The transmittance at a wavelength of 380 nm to 780 nm when measured using an infrared spectrophotometer (manufactured by JASCO Corporation, V-7100) was taken as the total light transmittance. The total light transmittance is a Y value measured with a 2-degree field of view (C light source) according to JIS Z8701 and subjected to visibility correction.
(5) Haze Measured using a haze meter (manufactured by Murakami Color Science Laboratory, trade name "HN-150") according to the method defined in JIS 7136.

[Production Example 1: Adhesive Layer A Containing Colorant]
Butyl acrylate (BA): 60 parts by weight, cyclohexyl acrylate (CHA): 6 parts by weight, 4-hydroxybutyl acrylate (4HBA): 26 parts by weight, hydroxyethyl acrylate (HEA): 8 parts by weight. , 2,2-dimethoxy-1,2-diphenyl-1-one (trade name “Irgacure 651”, manufactured by BASF Japan): 0.09 parts by weight, and 1-hydroxy-cyclohexyl-phenyl-ketone (trade name “ Irgacure 184", manufactured by BASF Japan): 0.09 part by weight is put into a four-necked flask and partially photopolymerized by exposing it to ultraviolet rays in a nitrogen atmosphere to obtain a portion with a polymerization rate of about 10%. A polymer (monomer syrup) was obtained. To 100 parts by weight of this partial polymer, 0.12 parts by weight of dipentaerythritol hexaacrylate (“KAYARAD DPHA” manufactured by Nippon Kayaku Co., Ltd.) as a polyfunctional polymerizable compound, and 3-glycidoxypropyl as a silane coupling agent Trimethoxysilane (manufactured by Shin-Etsu Chemical "KBM-403"): Add 0.3 parts by weight and mix uniformly to prepare an adhesive (adhesive composition), 9050 BLACK (manufactured by Tokushiki) as a coloring material was added in an amount of 0.09 parts per 100 parts by weight of the polymer. Thus, an adhesive composition A was obtained.

The pressure-sensitive adhesive composition A obtained above was applied to a release liner R1 (manufactured by Mitsubishi Plastics, Inc., MRF#38) having a thickness of 38 μm and having one side of the polyester film as the release surface, and one side of the polyester film was the release surface. A release liner R2 (manufactured by Mitsubishi Plastics Co., Ltd., MRE #38) with a thickness of 38 μm is covered to block air, and the pressure-sensitive adhesive layer A (thickness: 250 μm, total light transmission modulus 71.0%, haze 1.9%).

[Production Example 2: Adhesive layer B containing no colorant]
A pressure-sensitive adhesive layer B (thickness: 250 μm, total light transmittance: 92.0%, haze: 0.3%) was formed in the same manner as in Production Example 1, except that the pressure-sensitive adhesive composition was prepared without blending the coloring material. bottom.

[Production Example 3: Printed layer forming composition A]
As a coloring material (black pigment), "HF GV3 RX01" manufactured by Seiko Advance Co., Ltd. was impregnated in a solvent at a concentration of 10% by weight to obtain a composition for forming a black printed layer.

[Production Example 4: Printed Layer Forming Composition B]
A black printed layer-forming composition B was obtained in the same manner as in Production Example 3, except that the concentration of the coloring material was 15% by weight.

[Production Example 5: Polarizing plate A]
1. Preparation of Polarizer A polyvinyl alcohol film having an average degree of polymerization of 2,400, a degree of saponification of 99.9 mol % and a thickness of 45 μm was prepared. A polyvinyl alcohol film is immersed in a swelling bath (water bath) at 20° C. for 30 seconds between rolls having different circumferential speed ratios, and stretched by 2.2 times in the conveying direction while swelling (swelling step). While immersed in a dyeing bath (an aqueous solution with an iodine concentration of 0.1% by weight and a potassium iodide concentration of 0.9% by weight) at 30°C for 30 seconds to dye, the original polyvinyl alcohol film (completely stretched in the conveying direction) It was stretched 3.3 times in the conveying direction (dyeing process) based on the polyvinyl alcohol film that was not uncoated). Next, the dyed polyvinyl alcohol film is immersed in a 40° C. crosslinking bath (aqueous solution with boric acid concentration of 3.0% by weight and potassium iodide concentration of 3.0% by weight) for 28 seconds to restore the original polyvinyl alcohol film. The film was stretched up to 3.6 times in the transport direction (crosslinking step). Furthermore, the obtained polyvinyl alcohol film was immersed in a 61° C. stretching bath (an aqueous solution with a boric acid concentration of 4.0% by weight and a potassium iodide concentration of 5.0% by weight) for 60 seconds to stretch the original polyvinyl alcohol film. After stretching up to 6.0 times in the conveying direction with respect to the alcohol film (stretching step), it was immersed for 10 seconds in a washing bath (aqueous solution having a potassium iodide concentration of 2.0% by weight) at 20 ° C. (washing process). The washed polyvinyl alcohol film was dried at 40° C. for 30 seconds to prepare a polarizer. The thickness of the polarizer was 18 μm.

2. Preparation of polarizing plate As an adhesive, a polyvinyl alcohol resin containing an acetoacetyl group (average degree of polymerization: 1,200, saponification degree: 98.5 mol%, acetoacetylation degree: 5 mol%) and methylolmelamine were used. An aqueous solution containing 3:1 weight ratio was used. Using this adhesive, a 30 μm thick protective layer made of (meth)acrylic resin (modified acrylic polymer having a lactone ring structure) was formed on one surface (display element side) of the polarizer obtained above. A transparent protective film (manufactured by Nippon Shokubai Co., Ltd.) of 49 μm in thickness is formed by forming HC on a triacetyl cellulose film (manufactured by Fujifilm, product name “TJ40UL”) as a protective layer on the other side (viewing side). After laminating the protective films with a roll laminator, they were subsequently heat-dried in an oven (at a temperature of 90°C for 10 minutes) to prepare a polarizing plate in which transparent protective films were laminated on both sides of the polarizer. bottom. The obtained polarizer had a single transmittance of 41.7% and a degree of polarization of 99.9%.

[Production Example 6: Surface base material layer A]
An antireflection film (manufactured by Nitto Co., Ltd., (product name: "T-60LA28HCAR6N", thickness: 85 μm) were bonded together to obtain a surface base layer A having a structure of [glass film/TAC film/antireflection layer].

[Example 1]
By silk screen printing, the printed layer forming composition A was applied along the outer periphery of one surface of the polarizing plate A (TAC surface with HC) in a frame shape having a width of 1.5 mm in plan view, and allowed to dry naturally. to form a black printed layer with a thickness of 5 μm. Then, the printed layer forming composition A was applied in the same manner by silk screen printing again on the printed layer and dried at 50 ° C. for 1 hour to form a black printed layer having a thickness of 5 μm (finally formed thickness of printed layer A applied: 10 μm). Next, the pressure-sensitive adhesive layer A is transferred from the release liner to the side of the polarizing plate A on which the printed layer is formed, and the surface base layer A is laminated thereon so that the glass film faces the pressure-sensitive adhesive layer A side. rice field. At this time, the step portion at the boundary between the printed layer A and the polarizing plate A was completely filled with the pressure-sensitive adhesive layer A, and no gap was formed. As a result, an optical laminate having a structure of [polarizing plate A/printing layer A/adhesive layer A/surface base layer A] was obtained.

[Example 2]
The composition of [polarizing plate A/printing layer B/adhesive layer A/surface base layer A] was prepared in the same manner as in Example 1 except that the printing layer B was formed using the printing layer forming composition B. An optical laminate having

[Comparative Example 1]
In the same manner as in Example 1 except that the adhesive layer B was used instead of the adhesive layer A, an optical having a configuration of [polarizing plate A/printing layer A/adhesive layer B/surface base layer A] A laminate was obtained.

[Comparative Example 2]
By silk screen printing, the printed layer forming composition A is applied along the outer periphery of the glass film surface of the surface base layer A in a frame shape with a width of 1.5 mm in plan view, and naturally dried to a thickness of 5 μm. A black printed layer was formed. Then, the printed layer forming composition A was applied in the same manner by silk screen printing again on the printed layer and dried at 50 ° C. for 1 hour to form a black printed layer having a thickness of 5 μm (finally formed thickness of printed layer A applied: 10 μm). Next, the pressure-sensitive adhesive layer A was transferred from the release liner to the surface of the glass film on which the printed layer was formed, and the polarizing plate A was attached thereon. At this time, the step portion at the boundary between the printed layer A and the glass film was completely filled with the pressure-sensitive adhesive layer A, and no gap was generated. As a result, an optical laminate having a configuration of [polarizing plate A/adhesive layer A/printing layer A/surface base layer A] was obtained.

[Comparative Example 3]
In the same manner as in Comparative Example 2 except that the adhesive layer B was used instead of the adhesive layer A, an optical having a configuration of [polarizing plate A/adhesive layer B/printing layer A/surface base layer A] A laminate was obtained.

[Comparative Example 4]
In the same manner as in Example 2 except that the adhesive layer B was used instead of the adhesive layer A, an optical having a configuration of [polarizing plate A/printing layer B/adhesive layer B/surface base layer A] A laminate was obtained.

A transparent acrylic pressure-sensitive adhesive layer (manufactured by Nitto Denko Corporation, thickness 20 μm, total light transmittance 88% or more, haze 0.8% or less) was provided on the polarizing plate A side of the optical laminates of Examples and Comparative Examples, A black acrylic plate (manufactured by Nitto Jushi Kogyo Co., Ltd., product name “CLAREX”) as a substitute for a display element during non-display was attached via the acrylic pressure-sensitive adhesive layer to obtain an evaluation sample. Regarding the evaluation sample, the color difference ΔE*ab between the display area and the non-display area and the reflectance were measured.

In addition, regarding the above evaluation samples, boundary visibility evaluation between the display area and the non-display area was performed under fluorescent lamp lighting. Evaluation criteria are as follows.
[Evaluation criteria]
+2: The boundary is almost invisible.
+1: Improved compared to Comparative Example 3, but the boundary is visible.
0: The difference in appearance between the display area and the non-display area (border visibility) is about the same as in Comparative Example 3.
-1: The boundary is visible compared to Comparative Example 3.
-2: The boundary is clearly visible.

Table 1 shows the configuration and evaluation results of each optical layered body.

As shown in Table 1, according to the optical layered body according to the embodiment of the present invention, when used in an image display device, compared to the optical layered body of the comparative example, ΔE*ab is small, thereby making it difficult to recognize the difference in appearance between the display area and the non-display area when not displayed, and good seamlessness can be achieved. Here, the optical layered body of Comparative Example 2 has the configuration proposed in Patent Document 1, and the optical layered body of Comparative Example 3 has the prior art configuration. Comparing Comparative Example 1 and Comparative Example 3, simply providing the printed layer on the visible side surface of the polarizing plate increases the color difference, and the seamless effect is not confirmed. The color difference between the display area and the non-display area can be greatly reduced by providing a colored pressure-sensitive adhesive layer having a light absorbing function thereon, and good seamlessness is achieved. Further, when comparing Comparative Examples 1 and 4, the color difference is affected by the different colors of the printing layers. It can be seen that even when the colors of the layers are different, the effect on the color difference is suppressed and the seamless effect is maintained.

The optical laminate of the present invention can be suitably used for image display devices.

REFERENCE SIGNS LIST 10 polarizing plate 12 polarizer 20 printing layer 30 first adhesive layer 40 second adhesive layer 50 release liner 60 surface substrate layer 100 optical laminate 110 backlight unit 120 polarizing plate 130 liquid crystal cell 140 touch panel 150 organic EL Element 200 Image display device

Claims (11)

An optical layered body comprising, in this order, a polarizing plate containing a polarizer, a printed layer provided along the outer periphery of the polarizing plate, and a first pressure-sensitive adhesive layer containing a coloring material. 2. The optical laminate according to claim 1, wherein the total light transmittance of the first pressure-sensitive adhesive layer is 10% to 90%. 3. The optical laminate according to claim 1, wherein the haze of the first pressure-sensitive adhesive layer is more than 1.0% and not more than 10.0%. The optical laminate according to any one of claims 1 to 3, wherein the printed layer has a thickness of 3 µm to 30 µm. 5. The optical laminate according to any one of claims 1 to 4, further comprising a second pressure-sensitive adhesive layer on the opposite side of the polarizing plate to the printed layer. 6. The optical laminate according to any one of claims 1 to 5, further comprising a surface base material layer on the side of the first pressure-sensitive adhesive layer opposite to the side on which the printed layer is arranged. 6. The optical laminate according to any one of claims 1 to 5, further comprising a release liner on the side of the first pressure-sensitive adhesive layer opposite to the side on which the printed layer is arranged. A display element and the optical laminate according to any one of claims 1 to 6 are provided in this order toward the viewing side,
An image display device, wherein the optical layered body is arranged such that the printed layer is on the viewer side of the polarizing plate. The SCI method L*a*b* color difference (CIE 1976) between the portion provided with the print and the portion not provided with the print layer when viewed from the viewing side when not displayed is less than 2.0 9. The image display device according to claim 8, wherein: 10. An image display device according to claim 8 or 9, wherein said display element comprises a liquid crystal cell, an organic electronic element or an inorganic electronic element. 11. The image display device according to claim 10, wherein said display element further includes a touch panel.

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