TW202325537A - Optical laminate and image display device - Google Patents

Abstract

The present invention provides: an optical laminate in which a first polarizing plate and a second polarizing plate each including a polarizer are layered such that the absorption axis directions of the polarizers are substantially parallel, and a print layer is provided along the outer peripheral section of the surface of the first polarizing plate on the side where the second polarizing plate is disposed; and an image display device comprising a display element and the optical laminate in this order toward the viewing side.

Description

Optical laminate and image display device

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

In recent years, automobiles have been equipped with displays for various purposes such as various meter displays, car navigation, rear monitors, and audio-visual. In the above-mentioned vehicle-mounted display, in order to harmonize the appearance of the frame member of the display itself or the surrounding members such as the instrument panel and the console, and to shield the wiring, terminals, etc., a colored portion is provided along the outer periphery of the display screen, thereby forming display area and non-display area. Moreover, the tablet terminal for general use or business use is also often provided with a colored portion along the outer peripheral portion of the display screen.

In an image display device with a colored portion along the outer periphery of the display screen, there may be a significant difference in appearance between the display area (black screen) and the non-display area (colored portion) during non-display (when the power is turned off), Improvement is needed from a design point of view.

With regard to the above requirements, Patent Document 1 proposes a display body that reduces the color difference between the display area and the non-display area during non-display, but further improvement is still needed. prior art literature patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2020-192708

The problem to be solved by the invention The present invention is made to solve the above-mentioned problems, and its main purpose is to provide an image display device, which is provided with a colored portion along the outer periphery of the display screen, and it is difficult to recognize the difference in appearance between the display area and the non-display area when the display is not displayed.

means to solve problems According to one aspect of the present invention, there is provided an optical layered body, in which a first polarizer and a second polarizer each including a polarizer are laminated in such a way that the absorption axes of the polarizers are substantially parallel to each other; and the optical layered system is along the first polarizer. A printed layer is provided on the outer peripheral portion of the surface of the first polarizing plate on which the second polarizing plate is disposed. In one embodiment, the total light transmittance of the optical laminate is greater than 35.0%. In one embodiment, the above-mentioned printing layer has a thickness of 3 μm˜30 μm. In one embodiment, the first polarizing plate and the second polarizing plate are bonded through an adhesive layer. In one embodiment, a surface base material layer is laminated on the side of the first polarizing plate opposite to the side where the second polarizing plate is arranged. In one embodiment, a surface base material layer is laminated on the side of the second polarizing plate opposite to the side where the first polarizing plate is arranged. According to another aspect of the present invention, there is provided an image display device, which includes a display element and the above-mentioned optical laminate in sequence toward the viewing side. In one embodiment, the L*a*b* color difference (CIE 1976) of the part provided with the printed layer and the part not provided with the printed layer is less than 1.5 when viewed from the viewing side during non-display. In one embodiment, when viewed from the viewing side during non-display, the reflectance of the portion provided with the printed layer by the SCI method is 2.5% or less. In one embodiment, the display element includes a liquid crystal cell, an organic electronic element, or an inorganic electronic element. In one embodiment, the above-mentioned display element further includes a touch panel.

Invention effect An image display device according to an embodiment of the present invention has a configuration in which two polarizers are stacked coaxially on the viewing side of a display element, and a printed layer is disposed therebetween. By adopting such a configuration, the difference in appearance between the display area and the non-display area can be hardly recognized when the display is not displayed without greatly reducing the brightness of the display area.

Preferred embodiments of the present invention will be described below, but the present invention is not limited to these embodiments. In addition, in this specification, the symbol "~" which shows a numerical range includes the numerical value of the upper limit and the lower limit.

A. Optical laminate The optical layered body of the embodiment of the present invention has the following structure: the first polarizing plate and the second polarizing plate each including a polarizer are laminated in a manner that the absorption axis directions of the polarizers are substantially parallel to each other; A printed layer is provided on the outer peripheral portion of the surface of the polarizing plate on which the second polarizing plate is disposed. The optical laminate is suitable for making an image display device. In this case, it is arranged on the viewing side of display elements such as organic electroluminescent (EL) elements, inorganic EL elements, and liquid crystal cells. Align the absorption axis directions of the two polarizers and stack them on the viewing side of the display element, and arrange a printed layer between the polarizers, thereby suppressing the decrease in brightness of the image display device and reducing the display during non-display The color difference and reflectivity between the display area and the non-display area in the screen can obtain the effect that the boundary is not easy to be identified. In addition, in the following description, the case where it is difficult to recognize (inconspicuous) the difference in appearance between the display area and the non-display area may be referred to as "the seamlessness of the display area and the non-display area".

A-1. The overall composition of the optical laminate Fig. 1A is a schematic cross-sectional view (a) and a schematic plan view (b) of an optical laminate according to an embodiment of the present invention. In the optical laminate 100a shown in FIG. 1A, the first polarizing plate 10 comprising the first polarizing element 12 and the second polarizing plate 20 comprising the second polarizing element 22 are substantially opposite to each other in the direction of the absorption axes of the polarizing elements 12 and 22. Lay layers in parallel. Moreover, the printed layer 30 is provided along the outer peripheral part of the surface of the 1st polarizer 10 on the side where the 2nd polarizer 20 is arrange|positioned. As shown in FIG. 1(b), the printed layer 30 is provided in a frame shape along the outer periphery of the main surface of the first polarizer 10 on the side of the second polarizer 20, and the optical laminate 100a is disposed on the display element. When constituting an image display device, the portion not provided with the printed layer 30 (in other words, the portion surrounded by the printed layer 30 ) becomes the display area A, and the portion provided with the printed layer 30 becomes the non-display area B. In addition, in the example shown in the figure, the first polarizing plate 10 and the second polarizing plate 20 are bonded through the adhesive layer 40, but as long as the effect of the present invention can be obtained, they can also be adhesive layers that do not pass through the adhesive layer, adhesive layer, etc. And the composition of simple layers. In addition, in this specification, substantially parallel includes the range where the angle formed by two directions is 0°±10°, preferably includes 0°±5°, more preferably includes 0°±3°.

1B and 1C are schematic cross-sectional views of an optical laminate according to an embodiment of the present invention, respectively. In the optical layered body 100b shown in FIG. 1B, the surface base material layer 50 is laminated|stacked on the side opposite to the side where the 2nd polarizer 20 of the 1st polarizer 10 is arrange|positioned. The surface substrate layer 50 is a layer that can function as a front panel of an image display device. Therefore, the optical laminate 100b can be used to make the polarizing plate with a printed layer, that is, the first polarizing plate 10, more visible than the second polarizing plate 20. The side is configured on the viewing side of the display element.

In the optical layered body 100c shown in FIG. 1C, the surface base material layer 50 is laminated|stacked on the side opposite to the side where the 1st polarizer 10 is arrange|positioned of the 2nd polarizer 20. As shown in FIG. As mentioned above, the surface base material layer 50 is a layer that can function as the front panel of an image display device. Therefore, the optical laminate 100c can make the second polarizing plate 20 more compact than the first polarizing plate 10, which is a polarizing plate with a printed layer. It is arranged on the viewing side of the display element by means of the viewing side.

Although not shown in the figure, the above-mentioned optical layered body may further include an adhesive layer for bonding to adjacent members such as display elements. For example, an adhesive layer may be provided on either or both surfaces of the optical layered body 100a, the surface of the optical layered body 100b on the second polarizing plate 20 side, or the surface of the optical layered body 100c on the first polarizing plate 10 side. These pressure-sensitive adhesive layers disposed on the outermost layer of the optical laminate may be protected by a release liner until it is used.

The optical layered body according to the embodiment of the present invention is not limited to the configuration of the illustrated examples. For example, each embodiment can be combined suitably. Moreover, an optical layered body may further have arbitrary appropriate components according to the purpose. The constituent elements include, for example, a retardation layer, a surface protection film, and the like. Each constituent element may be laminated through any appropriate adhesive layer (adhesive layer, adhesive layer, etc.) as needed.

The total light transmittance of the display area of the optical laminate is, for example, greater than 35.0%, preferably 39.0%-42.5%, more preferably 42.5%-45%.

The reflectance (SCI method) of the non-display area of the optical laminate is, for example, 10% or less, preferably 1.0%-10%, more preferably 1.0%-5.0%. The reflectance (SCI method) of the display area is, for example, less than 10% or less than 10%, preferably 1.0%-10%, more preferably 1.0%-5.0%. When the optical laminate has a surface substrate layer (such as a surface substrate layer with an anti-reflection layer), the reflectance (SCI method) of the non-display region of the optical laminate may be less than 2.5%, preferably 0.5% to 2.0 %, preferably 0.5%~1.0%. The reflectivity (SCI method) of the display area may be less than 2.5%, preferably 0.5%-2.0%, more preferably 0.5%-1.0%.

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

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

A-2. The first polarizing plate and the second polarizing plate Each of the first polarizer and the second polarizer includes a polarizer, and typically each further includes a protective layer disposed on one side or both sides of the polarizer. The first polarizing plate and the second polarizing plate may have the same configuration or different configurations. Regarding the polarizer and the protective layer that may be included in the first polarizing plate and the second polarizing plate, the following description can be applied in the same manner unless otherwise specified. In addition, the surface substrate layer that can function as the front panel may have a larger size than other components, and when the first polarizing plate is placed on the viewing side of the second polarizing plate, the first polarizing plate may also be Formed to have the same size as the surface base material layer.

A-2-1. Polarizer The polarizer is typically composed of a polyvinyl alcohol-based resin film containing a dichroic substance (such as iodine). The polarizer can be made of a single-layer resin film, or a laminate of two or more layers.

Specific examples of polarizers composed of a single-layer resin film include polyvinyl alcohol (PVA)-based films, partially formalized PVA-based films, ethylene-vinyl acetate Ester copolymers are partially saponified films and other hydrophilic polymer films that are dyed and stretched; polyene-based oriented films such as dehydrated PVA or dehydrochloridized polyvinyl chloride. In view of excellent optical properties, it is preferable to use a polarizer obtained by dyeing a PVA film with iodine and uniaxially stretching it.

The above-mentioned dyeing with iodine can be performed, for example, by immersing a PVA-based film in an iodine aqueous solution. The elongation ratio of the above-mentioned uniaxial stretching is preferably 3 to 7 times. Elongation can be performed after dyeing or while dyeing. In addition, dyeing after stretching is also possible. Swelling treatment, crosslinking treatment, washing treatment, drying treatment, etc. are performed on the PVA-based film as necessary. For example, by immersing the PVA-based film in water for washing before dyeing, not only can the dirt and anti-adhesive agent on the surface of the PVA-based film be cleaned, but also the PVA-based film can be swelled to prevent uneven dyeing.

Specific examples of a polarizer using a laminate include a polarizer using a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a polarizer using a resin substrate. A polarizer obtained by coating a laminate of a base material and a PVA-based resin layer formed on the resin base material. A polarizer obtained by using a laminate of a resin base material and a PVA-based resin layer coated and formed on the resin base material can be produced, for example, by the following steps: apply a PVA-based resin solution to the resin base material and make it drying, forming a PVA-based resin layer on the resin substrate to obtain a laminate of the resin substrate and the PVA-based resin layer; and stretching and dyeing the laminate to make the PVA-based resin layer into a polarizer. In the present embodiment, extending typically includes immersing and extending the laminate in an aqueous solution of boric acid. And, if necessary, the stretching may further include stretching the laminate in air at a high temperature (for example, above 95° C.) before stretching in the boric acid aqueous solution. The laminate of the resin substrate/polarizer obtained can be used directly (that is, the resin substrate can also be used as a protective layer of the polarizer), or the resin substrate can be peeled off from the laminate of the resin substrate/polarizer and placed on the Any suitable protective layer suitable for the purpose is used by peeling off the surface layer. The details of the manufacturing method of the polarizer are described in, for example, Japanese Patent Laid-Open No. 2012-73580. In this specification, the entire description of the publication is incorporated by reference.

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

The polarizer should exhibit absorption dichroism at any wavelength between 380nm and 780nm. The single transmittance of the polarizer is, for example, above 41.0%, preferably 43.0%~46.0%, more preferably 44.5%~46.0%. The degree of polarization of the polarizer should be above 97.0%, more preferably above 99.0%, more preferably above 99.9%.

A-2-2. Protective layer The protective layer is composed of any appropriate film that can be used as a protective layer of a polarizer. Specific examples of the material used as the main component of the film include cellulose-based resins such as cellulose triacetate (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyamide-based resins, etc. Imide-based, polyether-based, poly-based, polystyrene-based, polynorthylene-based, polyolefin-based, (meth)acrylic-based and acetate-based transparent resins, etc. Further, (meth)acrylic, urethane, (meth)acrylate urethane, epoxy, polysiloxane and other thermosetting resins or ultraviolet curable resins may also be mentioned. Other examples include glassy polymers such as siloxane polymers. Moreover, the polymer film described in Unexamined-Japanese-Patent No. 2001-343529 (WO01/37007) can also be used. As the material of the 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, Examples thereof include a resin composition having an alternating copolymer of isobutylene and N-methylmaleimide and an acrylonitrile-styrene copolymer. The polymer film can be, for example, an extruded product of the above-mentioned resin composition.

When the polarizing plate is applied to an image display device, the thickness of the protective layer (outer protective layer) arranged on the opposite side to the display element is typically not more than 300µm, preferably not more than 100µm, more preferably 5µm~80µm, more preferably 10µm ~60µm. In addition, when surface treatment is applied, the thickness of the outer protective layer is the thickness including the thickness of the surface treatment layer.

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

In one embodiment, the inner protective layer is optically isotropic. In this specification, "optically isotropic" means that the in-plane retardation Re(550) of the retardation layer is 0nm~10nm, and the retardation Rth(550) in the thickness direction is -10nm~+10nm. In another embodiment, the inner protective layer (typically, the inner protective layer of the polarizing plate disposed on the display element side) is optically anisotropic, and is a retardation layer having any appropriate 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, and it is arranged such that the angle formed by its slow axis direction and the absorption axis direction of the polarizer is, for example, 45°±10°, preferably 45°±5°, more preferably 45° , which can be made into a circular polarizer. Here, "Re(550)" refers to the in-plane retardation measured at 23°C with light having a wavelength of 550nm, and can be obtained by the formula: Re=(nx-ny)×d. Also, "Rth(550)" is the retardation in the thickness direction measured at 23°C with light with a wavelength of 550nm, and can be obtained by the formula: Rth(λ)=(nx-nz)×d. Here, "nx" is the refractive index in the direction where the in-plane refractive index reaches the maximum (that is, the direction of the slow axis), and "ny" is the refractive index in the direction that is perpendicular to the slow axis in the plane (that is, the direction of the fast axis) , "nz" is the refractive index in the thickness direction, and "d" is the thickness (nm) of the layer (film).

A-3. Printing layer The printing layer is a colored layer that is colored by printing according to the application and desired design. The printing layer can be a design layer with a predetermined design, or a full-page coloring layer. The printing layer should be a full-page coloring layer, preferably black, blue, dark blue, purple, brown and other dark colors (for example, in the L*a*b* color space of the SCI method, the L* is below 50, and the a* value is + 10~-10, b* value is in the range of +10~-10), the coloring layer is more preferably black (for example, the L* of the L*a*b* color space of the SCI method is below 20, and the a* value is + 5~-5, b* value in the range of +5~-5) colored layer. By making the printed layer a black colored layer, it is possible to properly shield wiring, terminals, backlights, and other parts in the non-display area.

The printed layer can be formed in any appropriate pattern according to the purpose. Representatively, the printing layer can be formed into a frame shape on the main surface of the polarizer along its outer periphery, for example, it can be formed at a position corresponding to the frame. According to the above configuration, the non-display area can be shielded without using a frame.

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

The composition for forming a printing layer typically includes a binder, a colorant, a solvent, and any appropriate additives that may be used as needed. Binders include polychlorinated olefins (such as chlorinated polyethylene, chlorinated polypropylene), polyester resins, urethane resins, acrylic resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymers , Cellulose resin. Binder resins may be used alone or in combination of two or more. In one embodiment, the binder resin is a thermopolymerizable resin. Compared with photopolymerizable resin, the amount of thermopolymerizable resin can be used less, so the amount of colorant used (colorant content in the colored layer) can be increased. As a result, especially when a black colored layer is formed, a colored layer having a very small total light transmittance and excellent shielding properties can be formed. In one embodiment, the binder resin is a (meth)acrylic resin, preferably a (meth)acrylic resin containing a multifunctional monomer (such as neopentylthritol tri(meth)acrylate) as a copolymerization component. . By using a (meth)acrylic resin containing a multifunctional monomer as a copolymerization component, a printing layer having an appropriate modulus of elasticity can be formed. Moreover, the height difference can also be formed by the thickness of the printing layer, and the height difference can effectively play the function of preventing adhesion.

Colorant Any appropriate colorant can be used according to the purpose and desired color. The coloring material can be a pigment or a dye, preferably a pigment. Specific examples of pigments include: inorganic pigments such as titanium dioxide, zinc white, carbon black, iron ink, red lead, chrome vermilion, ultramarine blue, cobalt blue, chrome yellow, titanium yellow; phthalocyanine blue, indanthrene blue , isoindolinone yellow, benzidine yellow, quinacridone red, polyazo red, perylene red, aniline black and other organic pigments or dyes; metal pigments composed of aluminum, brass and other scaly foils; titanium dioxide Pearlescent pigments composed of scaly steel foils coated with mica and basic lead carbonate. When forming a black colored layer, carbon black, iron ink, and aniline black can be used suitably. At this time, it is advisable to use coloring materials together. This is because it can absorb visible light in a wide range and uniformly to form an uncolored (that is, completely black) colored layer. For example, azo compounds and/or quinone compounds may be used in addition to the above-mentioned colorants. In one embodiment, the coloring material includes carbon black and other coloring materials (such as azo compounds and/or quinone compounds) as main components. According to such a constitution, it is possible to form a colored layer that is colorless and excellent in stability over time. When forming a black colored layer, the coloring material is preferably used in a ratio of 50 parts by weight to 200 parts by weight relative to 100 parts by weight of the binder resin. At this time, the content ratio of carbon black in the pigment should be 80%~100%. By using the coloring material (especially carbon black) in such a ratio, a colored layer having a very small total light transmittance and excellent stability over time can be formed.

The total light transmittance of the printing layer is preferably less than 0.01%, more preferably less than 0.008%. If the total light transmittance is within the above range, the non-display area of the image display device can be well shielded.

The thickness of the printing 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 printing layer is within this range, the seamless effect of the display area and the non-display area can be properly obtained.

A-4. Adhesive layer The adhesive composition for forming the adhesive layer for laminating the first polarizing plate and the second polarizing plate and for laminating any other constituent elements may be any appropriate adhesive composition applicable to optical applications things. The total light transmittance of the adhesive layer is preferably above 85%, more preferably above 88%. Also, the haze of the adhesive layer is preferably 1.0% or less, more preferably 0.8% or less.

Any appropriate adhesive composition can be used for the above-mentioned adhesive composition. Examples include rubber-based, acrylic-based, silicone-based, urethane-based, vinyl alkyl ether-based, polyvinyl alcohol-based, polyvinylpyrrolidone-based, polyacrylamide-based, cellulose-based, etc. Adhesive composition. Among them, an acrylic adhesive composition is preferably used in terms of excellent optical transparency, adhesive properties, weather resistance, heat resistance, and the like.

The above-mentioned acrylic adhesive composition contains a (meth)acrylic polymer as a base polymer, and the (meth)acrylic polymer is a partial polymer containing a monomer component containing an alkyl (meth)acrylate and /or obtained from the monomer component.

The above-mentioned alkyl (meth)acrylate can be exemplified by one having a linear or branched alkyl group having 1 to 24 carbon atoms at the end of the ester group. Alkyl (meth)acrylate can be used individually by 1 type or in combination of 2 or more types. In addition, in this specification, "(meth)acrylate" means acrylate and/or methacrylate.

The above-mentioned alkyl (meth)acrylate may, for example, be a (meth)acrylate having a branched chain alkyl group having 4 to 9 carbon atoms. This alkyl (meth)acrylate is ideal in that it is easy to achieve a balance of adhesive properties. Specifically, n-butyl (meth)acrylate, secondary butyl (meth)acrylate, tertiary butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate ester, isopentyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate and ( Isononyl methacrylate, etc. can be used individually by 1 type or in combination of 2 or more types.

The above-mentioned alkyl (meth)acrylate having an alkyl group having 1 to 24 carbon atoms at the end of the ester group is preferably 40% by weight relative to the total amount of monofunctional monomer components forming a (meth)acrylic polymer Above, more preferably 50% by weight or more, more preferably 60% by weight or more.

In the above-mentioned monomer components, comonomers other than the above-mentioned alkyl (meth)acrylates (such as carboxyl-containing monomers, hydroxyl-containing monomers, amide-containing monomers, aromatic ring-containing (meth)acrylates, etc. etc.) as a monofunctional monomer component. The copolymerizable monomer can be used as the remainder of the above-mentioned alkyl (meth)acrylate in the monomer component.

The above-mentioned comonomers and their usage amounts can be applied to the comonomers and their usage amounts recorded in paragraphs 0029-0042 of Japanese Patent Application Laid-Open No. 2016-157077 or paragraphs 0022-0036 of Japanese Patent Application Laid-Open No. 2016-190996 The comonomers and their usage amounts described in the paragraphs.

In addition to the monofunctional monomer, the above-mentioned monomer component forming the (meth)acrylic polymer may optionally contain a polyfunctional monomer in order to adjust the cohesive force of the adhesive.

A polyfunctional monomer is a monomer having at least two polymerizable functional groups with unsaturated double bonds such as (meth)acryl or vinyl, for example: (poly)ethylene glycol di(methyl) Acrylates, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, neopentyl glycol tri(meth)acrylate , Dineopentylthritol hexa(meth)acrylate, 1,2-ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,12-dodecyl Esters of polyols such as alkanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate and (meth)acrylic acid; (meth)acrylic acid base) allyl acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butyl di(meth)acrylate, di(meth)acrylate Hexyl acrylate, etc. Among these, trimethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, and dipenteoerythritol hexa(meth)acrylate are suitably used. A polyfunctional monomer can be used individually by 1 type or in combination of 2 or more types.

The amount of polyfunctional monomers used varies depending on their molecular weight or functional groups, but relative to the total of 100 parts by weight of monofunctional monomers, it is better to use less than 3 parts by weight, more preferably less than 2 parts by weight. More preferably, it is 1 part by weight or less. Also, there is no particular limitation on the lower limit, but it is preferably 0 part by weight or more, more preferably 0.001 part by weight or more. When the usage-amount of a polyfunctional monomer exists in the said range, adhesive force can be improved.

The weight average molecular weight of the above-mentioned (meth)acrylic polymer is, for example, 1 million to 2.5 million, preferably 1.2 million to 2 million. Also, the molecular weight distribution (weight average molecular weight (Mw)/number average molecular weight (Mn)) is preferably 1.8 to 10, more preferably 1.8 to 7, more preferably 1.8 to 5. The weight average molecular weight and molecular weight distribution (Mw/Mn) are measured by GPC (gel permeation chromatography), and are calculated|required from the value calculated by polystyrene conversion.

The above (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, block polymerization, and emulsion polymerization can be appropriately selected. As the radical polymerization initiator, various known azo-based and peroxide-based ones can be used. The reaction temperature is usually set at about 50 to 80° C., and the reaction time is set at 1 to 8 hours. Also, among the above-mentioned production methods, the solution polymerization method is preferable, and ethyl acetate, toluene, etc. are generally used as solvents for (meth)acrylic polymers. The solution concentration is usually about 20 to 80% by weight. Moreover, the (meth)acrylic polymer obtained may be any of a random copolymer, a block copolymer, a graft copolymer, etc.

The above adhesive composition may contain a crosslinking agent. Examples of crosslinking agents include: isocyanate-based crosslinking agents, epoxy-based crosslinking agents, polysiloxane-based crosslinking agents, oxazoline-based crosslinking agents, acridine-based crosslinking agents, silane-based crosslinking agents, alkyl Etherified melamine crosslinking agent, metal chelate crosslinking agent, peroxide, etc. The crosslinking agent may be used alone or in combination of two or more. Among these, an isocyanate-based crosslinking agent can be used suitably.

The blending ratio of the (meth)acrylic polymer and the crosslinking agent is usually preferably 0.001 to 20 parts by weight of the crosslinking agent (solid content) per 100 parts by weight of the (meth)acrylic polymer (solid content). About, preferably about 0.01 to 15 parts by weight.

The above-mentioned adhesive composition may further contain: ultraviolet absorbers; tackifiers such as rosin derivative resins, polyterpene resins, petroleum resins, and oil-soluble phenol resins; plasticizers; fillers such as hollow glass spheres; pigments; agent; antioxidant; anti-aging agent; silane coupling agent and other additives. The amount of additives used can be appropriately set according to the purpose. For example, relative to 100 parts by weight of the above-mentioned monofunctional monomer components forming (meth)acrylic polymers, the amount of silane coupling agent used is preferably less than 1 part by weight, more preferably 0.01 parts by weight to 1 part by weight, more preferably It is 0.02 to 0.6 parts by weight.

The above-mentioned adhesive composition should be adjusted to a viscosity suitable for coating operations. Viscosity can be adjusted by adding a thickening polymer, a multifunctional monomer, etc., and partially polymerizing monomer components in the adhesive composition. This partial polymerization may be performed before adding the tackifier polymer, polyfunctional monomer, etc., or may be performed after adding it. The viscosity of the adhesive composition may vary due to the composition of the monomer components, the type and blending amount of additives, etc., so it is difficult to define the ideal polymerization rate of partial polymerization, but the polymerization rate can be 20% for example Below about 3%~20%, more preferably about 5%~15%. If the polymerization rate of partial polymerization is greater than 20%, the viscosity will become too high, making it difficult to coat the substrate.

The adhesive layer is formed by applying the above-mentioned adhesive composition on various base materials, followed by drying, radiation irradiation, etc. as required. When the adhesive layer is formed on a release film, the adhesive layer can be used by transferring from the release film to a desired member.

The thickness of the adhesive layer (thickness of the display area) for laminating the first polarizing plate and the second polarizing plate is, for example, 50 µm-1000 µm, preferably 200 µm-750 µm, more preferably 250 µm-500 µm. The thickness of the adhesive layer for laminating any other constituent elements may be, for example, 1 µm to 300 µm, preferably 5 µm to 100 µm, more preferably 10 µm to 50 µm.

A-5. Surface substrate layer The surface substrate layer can function as a front panel of an image display device. Therefore, when the optical layered body is arranged on the viewing side of the display element, the surface base material layer is preferably arranged at the outermost position. The surface substrate layer includes a substrate film, and may further include functional layers such as an antireflection layer, an antifouling layer, and a hard coat layer as required. The surface substrate layer preferably comprises an antireflection layer. The anti-reflection layer can be, for example, the following types: the thin-layer type disclosed in Japanese Patent Laid-Open No. 2005-248173, which uses the effect of offsetting reflected light by light interference to prevent reflection; Japanese Patent Laid-Open 2011- The surface structure type disclosed in Gazette No. 2759 exhibits low reflectivity by imparting a fine structure to the surface. A functional layer can be used 1 type or in combination of 2 or more types. The functional layer can be laminated on the base film through an adhesive layer (such as an adhesive layer, adhesive layer) in the state formed on the support film as required, or can be formed directly on the base film without passing through the adhesive layer.

As the base film, a glass film or a resin film can be used.

The glass constituting the glass film is classified according to its composition, such as soda-lime glass, borate glass, aluminosilicate glass, and quartz glass. Moreover, it classifies according to an alkali component, For example, non-alkali glass and low-alkali glass are mentioned. The thickness of the glass film is preferably 100µm~2000µm, more preferably 200µm~1000µm.

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

A-6. Peel off the liner The release liner can be, for example, a plastic (such as polyethylene terephthalate (PET)) 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. , polyethylene, polypropylene) film, non-woven fabric or paper, etc. The thickness of the release liner is, for example, 10 µm to 100 µm.

A-7. Other components The surface protection film has a base material and an adhesive layer arranged on one side of the base material. The surface protection film is provided to prevent scratches or stains on the surface of the optical layered body (for example, the surface of the surface substrate layer), and is usually peeled off before use.

As the retardation layer, a retardation layer functioning as a λ/4 plate can be suitably used. The retardation layer functioning as a λ/4 plate has, for example, an in-plane retardation Re(550) of 120 nm to 160 nm, preferably 135 nm to 155 nm. Also, the retardation layer functioning as a λ/4 plate can be arranged such that the direction of its slow axis and the direction of the absorption axis of the polarizer (polarizer) become, for example, 45°±10°, preferably 45°±5°, more preferably 45° angle. With this configuration, excellent circular polarization performance can be exhibited, for example, antireflection function can be exhibited when used in combination with an organic EL element.

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

The retardation layer is typically disposed on the display element side of the polarizing plate disposed on the display element side, and the axial relationship between the polarizing plate and the polarizing plate is as described above.

B. Image display device The image display device according to the embodiment of the present invention includes a display element and the optical laminate described in item A sequentially toward the viewing side. In one embodiment, the image display device includes a display element, a second polarizing plate, a printing layer, and a first polarizing plate in sequence toward the viewing side; the printing layer is arranged on the side of the first polarizing plate where the second polarizing plate The surface is arranged along its outer periphery; and the first polarizing plate and the second polarizing plate are arranged such that the directions of the absorption axes of the respective polarizers are substantially parallel to each other. In another embodiment, the image display device includes a display element, a first polarizing plate, a printing layer, and a second polarizing plate in sequence toward the viewing side; the printing layer is arranged on the side of the first polarizing plate where the second polarizing plate is arranged The surface is arranged along its outer periphery; and the first polarizing plate and the second polarizing plate are arranged such that the absorption axis directions of the respective polarizers are substantially parallel to each other. The image display device with the above structure has little difference in appearance between the display area (the area where the printed layer is not provided in the top view) and the non-display area (the area where the printing layer is provided in the top view) in the display screen during non-display, so the design excellent. Also, since the optical layered body itself has a high transmittance, reduction in luminance is suppressed.

The L*a*b* color space of the SCI mode of the display area in the display screen during non-display For example: L* should be below 15, more preferably below 10; a* should be -10~+10, preferably - 5~+5; b* should be -10~+10, more preferably -5~+5. In addition, the L*a*b* color space of the SCE mode of the display area in the display screen during non-display is: L* should be less than 10, more preferably less than 5; a* should be -10~+10, more preferably -5~+5; b* should be -10~+10, more preferably -5~+5.

The L*a*b* color difference (CIE 1976) ΔE*ab of the SCI method between the display area and the non-display area of the display screen during non-display mode should be less than 1.5, more preferably less than 1.4, and more preferably less than 1.3. 1.2 or less. Also, the L*a*b* color difference (CIE 1976)) ΔE*ab of the SCE method is preferably less than 4.0, more preferably 2.5 or less, more preferably 1.5 or less. When 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. In addition, L*a*b* color difference (CIE 1976) ΔE*ab is a value calculated by the following formula (where L* represents lightness, a* represents chroma a*, b* represents chroma b*) . 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 less than 2.0%, and more preferably less than 1.5%. The reflectance of the non-display area is preferably 2.5% or less, more preferably 2.0% or less, more preferably 1.5% or less. The reflectance difference between the two areas is preferably less than 0.3%, more preferably less than 0.15%.

The reflectance of the SCE method in the display area of the display screen during non-display is preferably 1.0% or less, more preferably 0.5% or less, more preferably 0.3% or less. The reflectance of the non-display area is preferably 1.0% or less, more preferably 0.5% or less, more preferably 0.3% or less. The reflectance difference between the two areas is preferably less than 0.3%, more preferably less than 0.15%.

Examples of the above-mentioned display elements include liquid crystal cells, organic EL elements, inorganic EL elements, and the like. Moreover, the display element may further include a touch panel. These display elements are well known to those skilled in the art, so detailed description thereof will be omitted.

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 200 a includes a backlight unit 110 , a rear-side polarizing plate 120 , a liquid crystal unit 130 , and an optical laminate 100 in order toward the viewing side. Preferably, the optical laminate 100 has an adhesive layer (not shown) on the outside of the second polarizer 20 , and is bonded to the liquid crystal unit 130 through the adhesive layer. In addition, the optical laminate 100 is arranged on the upper side so that the absorption axis direction of the second polarizing plate 20 (polarizer 22) is substantially perpendicular to the absorption axis direction of the back side polarizing plate 120 (for example, 90°±5°, preferably 90°). °±3°), and the second polarizer 20, the liquid crystal cell 130, and the rear side polarizer 120 constitute a liquid crystal panel.

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 200 b includes a backlight unit 110 , a backside polarizing plate 120 , a liquid crystal unit 130 , a touch panel 140 , and an optical laminate 100 in order toward the viewing side. Preferably, the optical laminate 100 has an adhesive layer (not shown) on the outside of the second polarizer 20 , and is bonded to the touch panel 140 through the adhesive layer. In addition, the optical layered body 100 is arranged such that the direction of the absorption axis of the second polarizing plate 20 (polarizer 22 ) is substantially perpendicular to the direction of the absorption axis of the back-side polarizing plate 120 . In the illustrated example, the touch panel is an upper structure, but it may also be a built-in structure.

2C is a schematic cross-sectional view of an image display device (organic EL display device) including an organic EL element as a display element. The image display device 200c includes the organic EL element 150 and the optical layered body 100 in this order toward the viewing side. The optical layered body 100 has a retardation layer 60 as a λ/4 plate on the back side of the second polarizing plate 20, and the retardation layer 60 is arranged such that the angle formed by the direction of its absorption axis and the direction of the absorption axis of the polarizer 22 becomes 45°. °. The optical laminate 100 is preferably bonded to the organic EL element 150 through an adhesive layer (not shown) disposed outside the retardation layer 60 .

In the example of the drawing above, the configuration in which the first polarizing plate is placed closer to the viewing side than the second polarizing plate is shown, but the configuration in which the second polarizing plate is closer to the viewing side than the first polarizing plate may also be used. Of course, no matter in any configuration, the surface base material layer is arranged on the surface of the viewing side.

EXAMPLES Hereinafter, the present invention will be specifically described by means of examples, but the present invention is not limited by these examples. In addition, the measurement method of each characteristic is as follows. (1) Thickness was measured with 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 to obtain L*a* b*. (Measurement conditions) Type of optical system for receiving light: SCI (including specular reflection light) or SCE (specular reflection exclusion) Measuring wavelength range: 360nm-740nm Light source: D65 Measuring diameter MAV: φ8mm Also, chromatic aberration (ΔE*ab) system It is calculated by the following formula. ΔE*ab=[(ΔL*) ² +(Δa*) ² +(Δb*) ² ] ^1/2 (3) The single transmittance and polarization degree of the polarizer use the ultraviolet-visible-near-infrared spectrophotometer (Japan Spectrophotometer V-7100 manufactured by the company) to measure the polarizing plate (protective layer/polarizer/protective layer), and use the measured single transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc 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) of JIS Z8701 and corrected for visual sensitivity. From the obtained Tp and Tc, the degree of polarization was calculated by the following formula. Degree of polarization (%)={(Tp-Tc)/(Tp+Tc)} ^{1 /2} ×100 (4) Total light transmittance A transparent acrylic system was installed on the polarizer side of the optical laminates obtained in the examples and comparative examples Adhesive layer (manufactured by Nitto Denko Co., Ltd., thickness 20µm, total light transmittance of more than 88%, haze less than 0.8%), and laminated on a glass film (manufactured by Matsuba Glass Industry Co., Ltd., product) with a thickness of 1 mm through the acrylic adhesive layer called "soda-lime glass"), the resulting product was used as a measurement sample, and measured using an ultraviolet-visible-near-infrared spectrophotometer (V-7100 manufactured by JASCO Corporation), and the transmittance at a wavelength of 380nm to 780nm at this time as total light transmittance. The total light transmittance is measured with the 2-degree field of view (C light source) of JIS Z8701 and the Y value after the sensitivity correction. (5) Haze According to the method prescribed|regulated to JIS7136, it measured using the haze meter (made by Murakami Color Research Laboratory Co., Ltd., brand name "HN-150").

[Manufacturing example 1: Adhesive layer A without colorant] Based on 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 Co., Ltd.): 0.09 parts by weight and 1-hydroxy- Cyclohexyl-phenyl-ketone (trade name "IRGACURE 184", manufactured by BASF Japan): 0.09 parts by weight were put into a four-necked flask, and exposed to ultraviolet rays under a nitrogen atmosphere to perform partial photopolymerization, thereby obtaining a polymerization rate of about 10%. Part of the polymer (monomer pulp). To 100 parts by weight of the polymer, diperythritol hexaacrylate ("KAYARAD DPHA" manufactured by Nippon Kayaku Co., Ltd.: 0.12 parts by weight) and 3-epoxy as a silane coupling agent were added as a polyfunctional polymerizable compound. Propoxypropyltrimethoxysilane ("KBM-403" manufactured by Shin-Etsu Chemical): 0.3 parts by weight, uniformly mixed to prepare an adhesive (adhesive composition). Thus, an adhesive composition A was obtained.

The adhesive composition A obtained above was coated on a release liner R1 (manufactured by Mitsubishi Plastics Corporation, MRF#38) with a thickness of 38 µm and one side of the polyester film was used as the release surface, and the one side of the polyester film was coated as the release surface Release liner R2 (manufactured by Mitsubishi Plastics Co., Ltd., MRE#38) with a thickness of 38 µm blocks the air, and is cured by irradiating ultraviolet rays to form an adhesive layer A (thickness 250 µm, total light transmittance 92.0%, haze 0.3%) .

[Manufacturing Example 2: Adhesive Layer B Containing Pigment] Adhesive layer B (thickness 250 µm, total light transmittance 71.0%, haze 1.9%).

[Manufacturing Example 3: Composition for Printing Layer Formation] "HF GV3 RX01" manufactured by Seiko Advance Ltd. as a colorant (black pigment) was impregnated in the solvent at a concentration of 10% by weight to obtain a black composition for printing layer formation.

[Manufacturing example 4: Polarizing plate] 1. Production 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. While immersing the polyvinyl alcohol film in a swelling bath (water bath) at 20°C for 30 seconds between rollers with different circumferential speed ratios to make it swell, extend it to 2.2 times in the conveying direction (swelling step), and then swell it at 30°C. ℃ 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) for 30 seconds for dyeing. Extend to 3.3 times in the conveying direction as a reference (dyeing step). Next, immerse the dyed polyvinyl alcohol film in a cross-linking bath (an aqueous solution with a boric acid concentration of 3.0% by weight and a potassium iodide concentration of 3.0% by weight) at 40°C for 28 seconds, and use the original polyvinyl alcohol film as a benchmark Extended to 3.6 times in the transport direction (cross-linking step). Then immerse the obtained polyvinyl alcohol film in a stretching bath (an aqueous solution with a concentration of boric acid of 4.0% by weight and a concentration of potassium iodide of 5.0% by weight) at 61°C for 60 seconds, and use the original polyvinyl alcohol film as a standard in the conveying direction After stretching to 6.0 times (stretching step), it was immersed in a 20° C. cleaning bath (an aqueous solution having a potassium iodide concentration of 2.0% by weight) for 10 seconds (washing step). The washed polyvinyl alcohol film was dried at 40° C. for 30 seconds to produce a polarizer. The thickness of the polarizer is 18µm.

2. Production of polarizing plate Adhesives use the following aqueous solution: polyvinyl alcohol resin containing acetoacetyl group in a weight ratio of 3:1 (average degree of polymerization 1,200, degree of saponification 98.5 mole%, degree of acetoacetylation 5 mole%) Those with hydroxymethylmelamine. Using this adhesive, bond a layer of (meth)acrylic resin (modified acrylic polymer having a lactone ring structure) with a thickness of 30 µm to one side of the polarizer (display element side) obtained above using a roll laminating machine. A transparent protective film (manufactured by Nippon Shokubai) is used as a protective layer, and on the other side (viewing side), a cellulose triacetate film (manufactured by FUJIFILM, trade name "TJ40UL") is attached to form a transparent protective film with a thickness of 49 µm of HC. After the film is used as a protective layer, it is then heated and dried in an oven (at a temperature of 90° C. for 10 minutes) to produce a polarizing plate with a transparent protective film attached to both sides of the polarizer. The single transmittance of the obtained polarizer was 41.7%, and the degree of polarization was 99.9%.

[Manufacturing Example 5: Surface Base Material Layer] An antireflection film (manufactured by Nitto, product name) having an antireflection layer/TAC film was attached to one side of a glass film (manufactured by Matsunami Glass Industry Co., Ltd., product name "soda-lime glass") with a thickness of 1 mm through the adhesive layer A. name "T-60LA28HCAR6N", thickness 85µm), and obtain a surface substrate layer with the composition of [glass film/TAC film/anti-reflection layer].

[Example 1] The polarizing plate produced in Production Example 4 was used as the first polarizing plate and the second polarizing plate. By screen printing, the composition for forming the printing layer was applied along the outer periphery of one surface of the first polarizing plate (the TAC surface with HC) in a frame shape with a width of 1.5 mm in plan view, and allowed to dry naturally A black printing layer with a thickness of 5 µm is formed. Next, the composition for forming a printing layer was applied in the same manner by screen printing again on the printing layer, and dried at 50° C. for 1 hour to form a black printing layer with a thickness of 5 μm (the final printing Layer thickness: 10 µm). Next, the adhesive layer A was transferred from the release liner to the side of the first polarizing plate on which the printed layer was formed, and the second polarizing plate was laminated thereon. At this time, the first polarizing plate and the second polarizing plate were arranged so that the absorption axes of the polarizers were parallel to each other. Also, the height difference between the printed layer and the first polarizing plate is completely filled by the adhesive layer A without creating voids. Next, on the opposite side of the first polarizing plate to the side on which the second polarizing plate is arranged, the surface base material layer is bonded through the adhesive layer A so that the glass film is on the side of the first polarizing plate. Thereby, the optical laminated body which has the structure of [2nd polarizing plate/adhesive layer A/printed layer/1st polarizing plate/surface base material layer] was obtained.

[Comparative example 1] By screen printing, the composition for forming the printing layer was applied along the outer periphery of the glass film surface of the surface substrate layer in a frame shape with a width of 1.5 mm in plan view, and dried at 80° C. for 15 minutes. Form a black printing layer with a thickness of 5 µm. Next, the composition for forming a printing layer was coated in the same manner by screen printing again on the printing layer, and dried at 120° C. for 30 minutes to form a black printing layer with a thickness of 5 μm (the final printing Layer thickness: 10 µm). Next, the 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 obtained in Production Example 4 was bonded thereon. At this time, the height difference between the printing layer and the glass film is completely filled by the adhesive layer A without creating any gaps. Thereby, the optical laminated body which has the structure of [polarizing plate/adhesive layer A/printed layer/surface base material layer] was obtained.

[Comparative example 2] Except for using the adhesive layer B when attaching the surface substrate layer with the printed layer and the polarizing plate, in the same manner as in Comparative Example 1, a product having [polarizing plate/adhesive layer B/printing layer/surface substrate layer was obtained. ] The composition of the optical laminate.

[Comparative example 3] By screen printing, the composition for forming the printing layer was applied along the outer peripheral portion of one surface of the polarizing plate obtained in Production Example 4 (the TAC surface with HC) in a frame shape with a width of 1.5 mm in plan view, and the It dries naturally to form a black printing layer with a thickness of 5 µm. Next, the composition for forming a printing layer was applied in the same manner by screen printing again on the printing layer, and dried at 50° C. for 1 hour to form a black printing layer with a thickness of 5 μm (the final printing Layer thickness: 10 µm). Next, the adhesive layer B was transferred from the release liner to the side of the polarizing plate on which the printed layer was formed, and then the surface substrate layer was bonded thereon so that the glass film was on the side of the polarizing plate. At this time, the height difference between the printing layer and the polarizing plate is completely filled by the adhesive layer B without any void. Thereby, the optical laminated body which has the structure of [polarizing plate/printed layer/adhesive layer B/surface base material layer] was obtained.

[Comparative example 4] In the same manner as in Comparative Example 3, except for laminating two sheets of adhesive layer B (as a result, a colored adhesive layer with a thickness of 500 µm was used), a product having [polarizing plate/printing layer/adhesive layer B/adhesive Layer B/Surface substrate layer] The optical layered body of the composition.

A transparent acrylic adhesive layer (manufactured by Nitto Denko Co., Ltd., thickness 20 µm, total light transmittance of 88% or more, and haze of 0.8% or less) was provided on the polarizing plate side of the optical laminates of Examples and Comparative Examples, and the acrylic adhesive layer was transmitted through the polarizer. The adhesive layer was bonded to a black acrylic plate (manufactured by Nitto Jushi Kogyo Co., Ltd., product name "CLAREX") as a substitute for a display element in non-display mode to prepare an evaluation sample. Regarding this evaluation sample, the color difference ΔE*ab and the reflectance between the display area and the non-display area were measured.

Moreover, with respect to the said evaluation sample, the boundary visibility evaluation of a display area and a non-display area was performed under lighting of a fluorescent lamp. The evaluation criteria are as follows. [Evaluation benchmark] +2: Almost impossible to see borders. +1: Improved compared to Comparative Example 1, but boundaries can be seen. 0: The difference in appearance (visibility of the boundary) between the display area and the non-display area is at the same level as that of Comparative Example 1. -1: Compared with Comparative Example 1, the boundary can be recognized. -2: The boundary can be clearly seen.

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

As shown in Table 1, when the optical laminate according to the embodiment of the present invention is used in an image display device, compared with the image display device of the comparative example, the color difference and reflectance between the display area and the non-display area during non-display are reduced. , and achieve good seamlessness.

Industrial availability The optical layered body of the present invention can be suitably used for image display devices.

10: 1st polarizer 12: The first polarizer 20: Second polarizer 22: The second polarizer 30: printing layer 40: Adhesive layer 50: surface substrate layer 60: Retardation layer 100,100a~100c: optical laminates 110: Backlight unit 120: polarizer 130: LCD unit 140: Touch panel 150: Organic EL element 200, 200a~200c: image display device A: display area B: non-display area

In Fig. 1A, (a) is a schematic cross-sectional view of an optical layered body according to an embodiment of the present invention; (b) is a schematic plan view of the optical layered body shown in (a). Fig. 1B is a schematic cross-sectional view of an optical laminate according to an embodiment of the present invention. Fig. 1C is a schematic cross-sectional view of an optical laminate according to an embodiment of the present invention. Fig. 2A is a schematic cross-sectional view of an image display device according to an embodiment of the present invention. Fig. 2B is a schematic cross-sectional view of an image display device according to an embodiment of the present invention. Fig. 2C is a schematic cross-sectional view of an image display device according to an embodiment of the present invention.

10: 1st polarizer

12: The first polarizer

20: Second polarizer

22: The second polarizer

30: printing layer

40: Adhesive layer

50: surface substrate layer

100: Optical laminate

110: Backlight unit

120: polarizer

130: LCD unit

200a: image display device

Claims (11)

An optical layered body, in which a first polarizing plate and a second polarizing plate each including a polarizer are laminated such that the absorption axis directions of the polarizers are substantially parallel to each other; and The optical layer system is provided with a printing layer along the outer peripheral portion of the surface of the first polarizing plate on which the second polarizing plate is disposed. For the optical laminated body of claim 1, the total light transmittance is greater than 35.0%. The optical laminate according to claim 1 or 2, wherein the thickness of the aforementioned printing layer is 3 µm to 30 µm. The optical laminate according to any one of claims 1 to 3, wherein the first polarizing plate and the second polarizing plate are bonded together through an adhesive layer. The optical laminate according to any one of claims 1 to 4, wherein a surface substrate layer is laminated on the side of the first polarizing plate opposite to the side where the second polarizing plate is disposed. The optical laminate according to any one of claims 1 to 4, wherein a surface base material layer is laminated on the side of the second polarizing plate opposite to the side where the first polarizing plate is disposed. An image display device comprising a display element and an optical laminate according to any one of Claims 1 to 6 in sequence toward the viewing side. Such as the image display device of claim 7, when it is viewed from the viewing side when it is not displayed, the L*a*b* color difference (CIE 1976) of the SCI method between the part provided with the aforementioned printed layer and the part not provided with the aforementioned printed layer ) is less than 1.5. In the image display device according to claim 7 or 8, when viewed from the viewing side during non-display mode, the reflectance obtained by the SCI method of the portion provided with the printing layer is 2.5% or less. The image display device according to any one of claims 7 to 9, wherein the display element includes a liquid crystal cell, an organic electronic element or an inorganic electronic element. The image display device according to claim 10, wherein the display element further includes a touch panel.

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