JP2020030395A - Composite front plate and method for manufacturing the same - Google Patents

Abstract

To provide a new composite front plate which is flexible and has a colored layer in a display-side surface.SOLUTION: The present invention relates to a composite front plate 100 arranged on the front plate side of an image display device for usage, the composite front plate 100 including a first resin layer 10 and a colored layer 20 partially provided and having a recognition side surface as a flat surface formed on the recognition side surface of the first resin layer 10 and a display side surface as a flat surface made of the display side surface of the first resin layer 10 and the display side surface of the colored layer 20.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a composite front plate and a method for manufacturing the same, and further relates to an optical laminate and an image display device.

  2. Description of the Related Art As various image display devices such as a liquid crystal display device and an organic electroluminescence display device, a configuration in which a front panel is provided on the viewing side of a display panel for the purpose of protecting the display panel is known. When the display panel is a touch panel, the front panel can also function as a touch surface.

  Japanese Patent Application Laid-Open No. 2014-238533 (Patent Document 1) discloses that a coloring layer is provided on a peripheral portion of a display side surface (a surface opposite to a viewing side surface) of a front plate provided on a viewing side of a display panel of an image display device. Is described as providing a printing layer. It is described that with such a configuration, an image display device that does not use a bezel can be realized.

JP 2014-238533 A

  In recent years, expectations for a flexible image display device have increased. The flexible image display device can be installed on a non-planar surface or a bent surface, and can be folded or formed into a scroll shape when being carried to improve portability.

  Patent Literature 1 describes that a resin film having flexibility can be used as a front plate. That is, a composite front plate in which a colored layer is provided on a display side surface of a resin film is disclosed.

  An object of the present invention is to provide a composite front panel having flexibility and having a coloring layer on a display side surface, and a novel composite front panel and a method for manufacturing the same. Specifically, it is an object of the present invention to provide a composite front panel in which air bubbles are less likely to be generated when the composite front panel is bonded to another member.

  The present invention provides a composite front plate, an optical laminate, an image display device, and a method of manufacturing the composite front plate described below.

[1] A composite front plate used by being arranged on the front side of an image display device,
Having a first resin layer and a coloring layer provided on a part thereof,
The viewing side surface is a plane configured by the viewing side surface of the first resin layer,
The composite front panel, wherein the display side surface is a plane formed by the display side surface of the first resin layer and the display side surface of the colored layer.

[2] The composite front panel according to [1], wherein the coloring layer contains a binder resin.
[3] When the thickness of the first resin layer is a (μm) and the thickness of the coloring layer is b (μm), the thickness ratio T1 (%) calculated by the following equation (1) is: The composite front plate according to [1] or [2], which satisfies the relationship of (2a).

T1 = b / a × 100 (1)
5 ≦ T1 ≦ 42 (2a)
[4] The composite front panel according to any one of [1] to [3], and a shielding layer laminated at a position corresponding to the coloring layer on the display side surface of the composite front panel. , Optical laminate.

[5] The optical laminate according to [4], wherein the thickness of the shielding layer is 12 μm or less.
[6] In the optical laminate, when the thickness of the first resin layer is a (μm), the thickness of the coloring layer is b (μm), and the thickness of the shielding layer is c (μm), the following formula ( The optical laminate according to [4] or [5], wherein the thickness ratio T2 (%) calculated in 3) satisfies the relationship of the following formula (4a).

T2 = (b + c) / a × 100 (3)
T2 ≧ 30 (4a)
[7] The composite front panel according to any one of [1] to [3],
An optical laminate comprising: a second resin layer laminated on the viewing side surface of the composite front panel; and at least one of a third resin layer laminated on the display side surface of the composite front panel.

[8] having the third resin layer laminated on the display side surface of the composite front panel via an adhesive layer,
The optical laminate according to [7], wherein the pressure-sensitive adhesive layer has a thickness of 2 μm to 25 μm.

  [9] An image display device comprising the composite front panel according to any one of [1] to [3], which is disposed on a front side.

[10] The method for producing a composite front panel according to any one of [1] to [3],
Forming the colored layer on a part of the substrate film,
A step of applying a resin layer-forming composition on the base film so as to cover the visible side surface of the colored layer, and drying to form the first resin layer;
Peeling the base film.

  According to the present invention, a novel composite front panel having flexibility and having a colored layer on the display side surface can be provided. Specifically, the present invention can provide a composite front plate that is less likely to generate bubbles when the composite front plate is bonded to another member.

It is an outline sectional view showing one form of a compound front board of the present invention. It is a schematic sectional drawing which shows an example of the manufacturing method of a composite front plate. It is a schematic sectional view showing a 1st embodiment of an optical layered product of the present invention. FIG. 5 is a schematic sectional view illustrating a second embodiment of the optical laminate of the present invention. It is an outline sectional view showing a 3rd embodiment of the optical layered product of the present invention. FIG. 2 is a schematic sectional view illustrating an example of an image display device 300. FIG. 3 is a top view of the image display device 300 as viewed from the viewing side. 4 shows an example of a bending mode when the image display device is a flexible display. FIG. 1 is a schematic sectional view showing a first embodiment of the image display device of the present invention. It is a schematic sectional view showing a 2nd embodiment of the image display device of the present invention. It is a schematic sectional view showing a 3rd embodiment of the image display device of the present invention. It is an outline sectional view showing a 4th embodiment of the image display device of the present invention. FIG. 2 is a schematic cross-sectional view illustrating an example of an optical laminate having a shielding layer according to the present invention. It is a schematic sectional view showing the modification of the optical layered product of a 1st embodiment. It is an outline sectional view showing the modification of the optical layered product of a 2nd embodiment. It is an outline sectional view showing the modification of the optical layered product of a 3rd embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings below, the scales are appropriately adjusted to facilitate understanding of the components, and the scales of the components shown in the drawings do not always match the scales of the actual components. The same reference numerals denote the same components, and the description of the same components is common unless otherwise specified.

[Composite front panel]
<Structure>
FIG. 1 is a schematic sectional view showing one embodiment of the composite front plate of the present invention. The composite front panel 100 shown in FIG. 1 has a first resin layer 10 and a coloring layer 20 provided partially. The composite front panel 100 has a display area A and a non-display area B, and the coloring layer 20 is provided in an area corresponding to the non-display area B.

  The viewing side surface 100a of the composite front panel 100 is a plane formed by the viewing side surface 10a of the first resin layer 10. The display side surface 100b of the composite front panel 100 is a plane formed by the display side surface 10b of the resin layer 10 and the display side surface 20b of the coloring layer 20.

  The composite front plate 100 has a function of protecting the front surface of the image display device, and may have a function as a touch sensor, a blue light cut function, a viewing angle adjustment function, and the like.

  The thickness of the composite front panel 100 is, for example, 20 μm or more and 1000 μm or less, preferably 30 μm or more and 500 μm or less, and more preferably 30 μm or more and 100 μm or less. The thickness of the coloring layer 20 is, for example, 80% or less, 60% or less, or 50% or less of the thickness of the composite front panel 100.

  When the thickness of the first resin layer 10 is a (μm) and the thickness of the colored layer 20 is b (μm), the composite front plate 100 has a thickness ratio T1 (%) calculated by the following equation (1). It is preferable to satisfy the relationship of the following formula (2a). The thickness of the first resin layer 10 means the thickness of the thickest part in the first resin layer 10, and thus matches the thickness of the composite front plate 100.

T1 = b / a × 100 (1)
5 ≦ T1 ≦ 42 (2a)
When the thickness ratio T1 exceeds 42%, it may be difficult to maintain the flatness of the viewing side surface of the composite front panel 100, and a concave step may be generated in the display area A on the viewing side surface. If the thickness ratio T1 is less than 5%, it may be difficult to obtain a sufficient optical density. More preferably, the thickness ratio T1 satisfies the relationship of the following expression (2b).

7.5 ≦ T1 ≦ 30 (2b)
Although the composite front panel 100 includes the colored layer 20 exposed on the display side surface 100b, the damage of the colored layer 20 can be suppressed because the display side surface 100b is flat. In addition, since the display-side surface 100b is flat, it is possible to suppress the incorporation of air bubbles due to the step between the colored layer and the resin layer during bonding with another layer.

<Production method>
2A to 2D are schematic cross-sectional views illustrating an example of a method for manufacturing the composite front panel 100. First, the base film 110 is prepared (FIG. 2A), and the coloring layer 20 is formed in a partial region on the base film 110 (FIG. 2B). Next, the resin layer forming composition is applied so as to cover the viewing side surface 20a of the colored layer 20, and the resin layer forming composition is dried or cured to form the resin layer 10 (FIG. 2 (c)). )). Next, the base film 110 is peeled off, and the display side surface 20b of the colored layer 20 and the display side surface 10b of the resin layer 10 are exposed to obtain a composite front plate sheet 100 '(FIG. 2 (d)). . Next, if necessary, the composite front panel sheet 100 'is cut, and unnecessary portions are cut and removed to obtain the composite front panel panel 100.

  The base film 110 is not particularly limited as long as it is not modified in the formation of the colored layer 20 and the resin layer 10 and can be separated from the composite front plate sheet 100 '. As a material for forming the base film 110, for example, a thermoplastic resin having excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, stretchability, and the like is used.

  Examples of such a thermoplastic resin include polyolefin resins such as chain polyolefin resins, cyclic polyolefin resins (norbornene resins), polyester resins, (meth) acrylic resins, cellulose triacetate, cellulose diacetate, and the like. Cellulose ester resin, polycarbonate resin, polyvinyl alcohol resin, polyvinyl acetate resin, polyarylate resin, polystyrene resin, polyethersulfone resin, polysulfone resin, polyamide resin, polyimide resin, or these And mixtures thereof. Further, a copolymer obtained by copolymerizing monomers of the above resin may be used as a material for forming the base film. Among these, polyolefin resins such as polypropylene and polyester resins such as amorphous polyethylene terephthalate are preferred.

  The thickness of the base film 110 is preferably from 1 to 500 μm, more preferably from 1 to 300 μm, further preferably from 5 to 200 μm, particularly preferably from 5 to 150 μm, from the viewpoint of strength and handleability.

(Colored layer)
The shape and color of the coloring layer 20 are not limited, and can be appropriately selected according to the application and design. As the coloring layer 20, a layer colored in a color such as black, red, white, dark blue, silver, or gold can be exemplified. The coloring layer 20 may be formed from a single layer, or may be formed from a plurality of layers. When the coloring layer 20 is formed from a plurality of layers, the coloring layer 20 may employ one color or a plurality of colors.

  When the coloring layer 20 is an organic layer containing a binder resin or the like, the thickness tends to be thicker than an inorganic layer containing a metal layer in order to achieve a certain optical density. When the coloring layer is thick, a step is likely to occur on the surface on the viewing side of the resin layer. According to one embodiment of the present invention, even when the coloring layer is formed of an organic layer, the step can be reduced by controlling the thickness ratio.

  The coloring layer 20 is formed on the base film by a printing method using an ink or a paint, a vapor deposition method using a powder of a metal pigment, a coloring layer 20 containing a metal pigment is previously formed, and this is bonded. The method can be used. Further, these methods may be combined. Specific examples of the printing method include gravure printing, offset printing, screen printing, and transfer printing from a transfer sheet. Printing by a printing method may be repeatedly performed to obtain the colored layer 20 having a desired thickness. The ink or paint used to form the colored layer 20 includes, for example, a binder resin, a colorant, a solvent, and any additives.

  Examples of the binder resin 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. Can be The binder resin may be used alone or in combination of two or more. The binder resin may be a thermopolymerizable resin or a photopolymerizable resin. The fact that the coloring layer contains a binder resin can contribute to improving the adhesion of the coloring layer 20 to the resin layer 10.

  The coloring agent can be appropriately selected according to the desired coloring. Examples of the colorant include inorganic pigments such as titanium white, zinc white, carbon black, iron black, red iron oxide, chrome vermillion, ultramarine, cobalt blue, graphite, titanium yellow, and the like; phthalocyanine blue, indaslen blue, and isoindia Organic pigments or dyes such as linone yellow, benzidine yellow, quinacridone red, polyazo red, perylene red, and aniline black; metal pigments composed of scale-like foil pieces such as aluminum and brass; scale-like forms such as titanium dioxide-coated mica and basic lead carbonate Pearlescent pigments (pearl pigments) composed of foil pieces are exemplified. The colorant is preferably contained in an amount of 50 to 200 parts by mass based on 100 parts by mass of the binder resin.

  The thickness of the coloring layer 20 is not particularly limited as long as it is a thickness that is not exposed on the viewing side surface 100a of the composite front panel 100. From the viewpoint of improving the shielding effect of the colored layer 20, the thickness is preferably 1 μm to 50 μm, more preferably 3 μm to 30 μm, and may be 3 μm to 20 μm. When the colored layer 20 is black, a high shielding effect can be obtained as compared with other colors even if the thickness is small.

The colored layer 20 has an optical density of preferably 2.0 or more, more preferably 2.5 or more, as measured by a method described in Examples described later.
The visible side surface 20a of the colored layer 20 is not limited to a shape substantially parallel to the display side surface 20b as shown in FIG. In order to provide design, the surface may be inclined or jagged. In addition, from the viewpoint of improving the bondability with the resin layer 10, the surface may be roughened.

  The colored layer is preferably one that does not dissolve or swell with the solvent contained in the resin layer forming composition.

  When the coloring layer 20 is provided on the peripheral edge of the composite front panel 100, the coloring layer 20 is not limited to the configuration provided on the entire circumference of the peripheral edge, but may be provided only on a part of the peripheral edge according to a desired design or the like. There may be. The width of the coloring layer 20 can be appropriately determined according to the size of the display area, a desired design, and the like, and can be, for example, in a range of 1 mm to 20 mm.

(First resin layer)
The polymer material contained in the first resin layer 10 is not particularly limited as long as it can transmit light. For example, triacetyl cellulose, acetyl cellulose butyrate, ethylene-vinyl acetate copolymer, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, polyester, polystyrene, polyamide, polyetherimide, polyacryl, polyimide, polyether sulfone, polysulfone , Polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyether sulfone, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene na A polymer material such as phthalate, polycarbonate, polyamideimide, alone or It can be assumed to include more. Among them, a resin layer containing a polymer material such as polyimide, polyamide, or polyamideimide, which can form a resin layer having excellent flexibility, high strength, and high transparency, is preferable.

  The composition for forming a resin layer contains a precursor of a polymer material or a polymer material, and a solvent capable of dissolving or dispersing these. It is preferable to select a solvent that does not swell or dissolve the colored layer. From such a viewpoint, as the solvent, N, N-dimethylacetamide (DMAc), N, N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), γ-butyrolactone (GBL), N-methylpyrrolidone (NMP) , Ethyl acetate, methyl ethyl ketone (MEK), tetrahydrofuran, 1,4-dioxane, acetone, cyclopentanone, dimethyl sulfoxide, xylene and combinations thereof. The composition for forming a resin layer may contain additives known in the art, such as a polymerization initiator, a polymerization initiation aid, a leveling agent, an antioxidant, and a light stabilizer, as necessary.

  The method for applying the resin-forming composition is performed using a conventionally known application method. Conventionally known coating methods include, for example, wire bar coating, reverse coating, roll coating such as gravure coating, die coating, comma coating, lip coating, screen coating, fountain coating, dipping, and spraying. And the like.

[Optical laminate]
One embodiment of the optical laminate of the present invention includes the above-described composite front panel 100 and a shielding layer laminated at a position corresponding to the colored layer 20 on the display side surface of the composite front panel.

  FIG. 13 is a cross-sectional view illustrating an example of an optical laminate having a shielding layer. The optical laminated body 501 shown in FIG. 13 has the composite front plate 100 shown in FIG. 1, and further has a shielding layer 25 laminated at a position corresponding to the colored layer 20 on the display side surface 100b. By having the shielding layer 25, the optical density of the non-display area B can be improved. The optical density of the non-display area B having the shielding layer 25 is preferably 3.0 or more.

  The thickness of the shielding layer 25 is 12 μm or less in order to prevent air bubbles from entering due to the shielding layer 25 protruding from the display side surface of the composite front panel 100 at the time of joining with another layer. It is more preferable that the thickness be 6 μm or less. The thickness of the shielding layer 25 can be, for example, 1 μm or more.

  In the optical laminate having the shielding layer 25, when the thickness of the first resin layer 10 is a (μm), the thickness of the coloring layer 20 is b (μm), and the thickness of the shielding layer 25 is c (μm), From the viewpoint of improving the optical density of the display area B, the thickness ratio T2 (%) calculated by the following equation (3) preferably satisfies the relationship of the following equation (4a).

T2 = (b + c) / a × 100 (3)
T2 ≧ 30 (4a)
Note that, in the optical laminated body configured using the composite front plate satisfying the following equation (2c), the above equation (4a) is always satisfied, but the following equation (2d) is not satisfied because the following equation (2c) is not satisfied. Even when the above condition is satisfied, an optical laminate satisfying the above formula (4a) can be formed by adjusting the thickness of the shielding layer 25. As one preferred embodiment of the optical laminate having the shielding layer 25, an optical laminate having the composite front plate 100 satisfying the following formula (2d) and the shielding layer 25 and satisfying the above formula (4a) is given. .

T1 ≧ 30 (2c)
T1 <30 (2d)
In the optical laminate having the shielding layer 25, the thickness ratio T2 (%) preferably satisfies the relationship of the following expression (4b).

T2 ≦ 50 (4b)
One embodiment of the optical laminate of the present invention includes, in addition to the composite front plate 100 described above, a second resin layer laminated on the viewing side surface 100a of the composite front plate 100, and a display side surface 100b of the composite front plate 100. It has at least one of the laminated third resin layers. The second resin layer is, for example, a hard coat layer. The third resin layer is, for example, a hard coat layer, a protective film, or the like. The protective film can be laminated via a bonding layer.

<First embodiment>
FIG. 3 is a schematic sectional view showing the first embodiment of the optical laminate of the present invention. The optical laminate 201 shown in FIG. 3 has the composite front plate 100, and further has the second resin layer 30 laminated on the viewing side surface 100a. FIG. 14 shows an optical laminate 502 which is a modification of the optical laminate 201 of the first embodiment. The optical laminate 502 differs from the optical laminate 201 only in having the shielding layer 25.

<Second embodiment>
FIG. 4 is a schematic sectional view showing a second embodiment of the optical laminate of the present invention. The optical laminate 202 shown in FIG. 4 has the composite front plate 100, and has the bonding layer 50 and the third resin layer 40 laminated on the display side surface 100b. FIG. 15 shows an optical laminate 503 which is a modification of the optical laminate 202 of the second embodiment. The optical laminate 503 differs from the optical laminate 202 only in having the shielding layer 25.

<Third embodiment>
FIG. 5 is a schematic sectional view showing a third preferred embodiment of the optical laminate of the present invention. The optical laminate 203 shown in FIG. 5 has the composite front plate 100, and includes the second resin layer 30 laminated on the viewing side surface 100a, the bonding layer 50 laminated on the display side surface 100b, and the third layer. And a resin layer 40. FIG. 16 shows an optical laminate 504 which is a modification of the optical laminate 203 of the third embodiment. The optical laminate 504 differs from the optical laminate 203 only in having the shielding layer 25.

(Second resin layer)
The second resin layer 30 laminated on the viewing side surface 100a of the composite front panel 100 is, for example, a hard coat layer. For example, when the optical laminate is used on the front surface of a touch panel type image display device, the second resin layer 30 having a high hardness and scratch resistance is preferably used because the second resin layer 30 serves as a touch surface. The hard coat layer is, for example, a cured layer of an ultraviolet curable resin. Examples of the ultraviolet curable resin include an acrylic resin, a silicone resin, a polyester resin, a urethane resin, an amide resin, and an epoxy resin. The hard coat layer may contain an additive to improve the strength. The additive is not limited, and examples thereof include inorganic fine particles, organic fine particles, and a mixture thereof.

(Third resin layer)
The third resin layer 40 laminated on the display side surface 100b of the composite front panel 100 is, for example, a hard coat layer, a protective film, or the like. As the third resin layer 40, a material having high hardness and scratch resistance is preferably used from the viewpoint of preventing damage during transportation and storage. The description of the second resin layer is applied to the hard coat layer.

  As the protective film, a protective film usually used in this technical field can be used. The material of the protective film is not particularly limited, for example, a cyclic polyolefin resin film, triacetyl cellulose, cellulose acetate resin film made of a resin such as diacetyl cellulose, polyethylene terephthalate, polyethylene naphthalate, poly Films known in the art, such as a polyester resin film made of a resin such as butylene terephthalate, a polycarbonate resin film, a (meth) acrylic resin film, and a polypropylene resin film, may be used. The thickness of the protective film is usually 300 μm or less, preferably 200 μm or less, more preferably 100 μm or less, and usually 30 μm or more, and preferably 40 μm or more, from the viewpoint of thinning. . The protective film may or may not have a retardation.

(Lamination layer)
The bonding layer 50 is a layer interposed between the composite front plate 100 and the third resin layer and bonded to each other. The bonding layer 50 is an adhesive layer or an adhesive layer, and the adhesive layer is suitably used.

  Since the coloring layer 20 is included in the composite front panel 100, the bonding layer 50 does not need to absorb the thickness of the coloring layer 20 and can be thin. The thickness of the bonding layer is, for example, 2 μm to 100 μm, and can be 2 μm to 25 μm, and 2 μm to 20 μm.

  The pressure-sensitive adhesive layer can be composed of a pressure-sensitive adhesive composition containing a resin such as a (meth) acrylic, rubber-based, urethane-based, ester-based, silicone-based, or polyvinyl ether-based resin as a main component. Among them, a pressure-sensitive adhesive composition using a (meth) acrylic resin having excellent transparency, weather resistance, heat resistance and the like as a base polymer is preferable. The pressure-sensitive adhesive composition may be an active energy ray-curable type or a thermosetting type.

  Examples of the (meth) acrylic resin (base polymer) used in the pressure-sensitive adhesive composition include butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, and 2- (meth) acrylate. A polymer or copolymer having one or more (meth) acrylates such as ethylhexyl as a monomer is preferably used. Preferably, a polar monomer is copolymerized with the base polymer. Examples of the polar monomer include (meth) acrylic acid, 2-hydroxypropyl (meth) acrylate, hydroxyethyl (meth) acrylate, (meth) acrylamide, N, N-dimethylaminoethyl (meth) acrylate, and glycidyl ( Examples thereof include monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group, and the like, such as (meth) acrylate.

  The pressure-sensitive adhesive composition may contain only the base polymer, but usually further contains a crosslinking agent. The crosslinking agent is a divalent or higher valent metal ion that forms a carboxylic acid metal salt with a carboxyl group; a polyamine compound that forms an amide bond with a carboxyl group; Epoxy compounds and polyols that form an ester bond with a carboxyl group; polyisocyanate compounds that form an amide bond with a carboxyl group are exemplified. Among them, a polyisocyanate compound is preferable.

  The active energy ray-curable pressure-sensitive adhesive composition has a property of being cured by being irradiated with an active energy ray such as an ultraviolet ray or an electron beam. And the like. The pressure-sensitive adhesive composition has a property of being able to adhere to an adherend such as that described above, and having a property of being hardened by irradiation with active energy rays to adjust the adhesion. The active energy ray-curable pressure-sensitive adhesive composition is preferably of an ultraviolet-curable type. The active energy ray-curable pressure-sensitive adhesive composition further contains an active energy ray-polymerizable compound in addition to the base polymer and the crosslinking agent. Further, if necessary, a photopolymerization initiator, a photosensitizer and the like may be contained.

  The pressure-sensitive adhesive composition includes fine particles for imparting light scattering properties, beads (resin beads, glass beads, etc.), glass fibers, resins other than base polymers, tackifiers, fillers (metal powders and other inorganic powders). Etc.), additives such as antioxidants, ultraviolet absorbers, dyes, pigments, colorants, defoamers, corrosion inhibitors, photopolymerization initiators and the like.

  It can be formed by applying an organic solvent diluted solution of the above-mentioned pressure-sensitive adhesive composition on a substrate and drying it. When the active energy ray-curable pressure-sensitive adhesive composition is used, a cured product having a desired degree of curing can be obtained by irradiating the formed pressure-sensitive adhesive layer with active energy rays.

(Shielding layer)
The shielding layer 25 is provided so as to correspond to the coloring layer 20, and the width of the shielding layer 25 in the plane direction is preferably substantially the same as the width of the coloring layer 20 in the plane direction. The shielding layer 25 contains a coloring agent. The coloring agent preferably contains a coloring agent having a high function of improving the optical density, and for example, preferably contains a black pigment such as carbon black or iron black. The shielding layer 25 may be formed from a single layer, or may be formed from a plurality of layers.

  The shielding layer 25 can be formed by a printing method, a coating method, or the like. The shielding layer 25 may be formed directly on the display side surface of the composite front panel 100, or may be formed by transferring what is formed on another base material onto the display side surface. The above description regarding the coloring layer 20 is applied to the printing method.

[Image display device]
The image display device of the present invention includes the above-described composite front panel 100 or the above-described optical laminate and a display laminate including a display panel, which are disposed on the front surface. The composite front panel or optical laminate and the display laminate can be laminated via a bonding layer.

  FIG. 6 is a schematic sectional view showing an example of the image display device 300. The image display device 300 has the composite front panel 100 on the viewing side, and has the bonding layer 51 and the display laminate 400 laminated on the display side surface of the composite front panel 100. As for the bonding layer 51, the description of the bonding layer 50 in the above-described optical laminate is applied.

  FIG. 7 is a top view of the image display device 300 as viewed from the viewing side. In the non-display area B at the peripheral portion, the colored layer 20 is visible. According to the coloring layer 20, wirings and the like arranged in the non-display area B can be shielded. As long as the colored layer 20 is provided so as to correspond to the non-display area B, the in-plane arrangement position is not limited. However, by arranging the colored layer 20 in the peripheral portion, light leakage can be suppressed, and like a frame. Thus, the design can be improved.

  The shape and size of the composite front panel 100 in the surface direction in the image display device 300 correspond to the shape and size in the surface direction of the image display device 300 in which the composite front plate 100 is used. The shape of the image display device 300 in the plane direction is preferably a square shape, and more preferably a square shape having a long side and a short side. This square shape is preferably rectangular. When the shape of the image display device 300 in the plane direction is rectangular, the length of the long side is, for example, 50 mm to 300 mm, and preferably 100 mm to 280 mm. The length of the short side is, for example, 30 mm to 250 mm, and preferably 60 mm to 220 mm. When the composite front plate 100 has a rectangular shape, at least one type of processing including rounding, notching, and drilling may be performed.

  The image display device 300 can be configured as a flexible display panel. FIG. 8 shows an example of a bending mode when the image display device is a flexible display. FIG. 8A shows a flexible display 305 configured to be foldable with the viewing side surface inside, and FIG. 8B shows a flexible display 306 that can be wound.

  The image display device 300 can be configured as a touch panel type image display device. The touch panel type image display device includes a touch sensor panel, and a composite front panel 100 provided on the front surface forms a touch surface. In the image display device of the touch sensor panel type, a configuration in which a hard coat layer is laminated on the viewing side surface of the composite front panel 100 is preferable.

<First embodiment>
FIG. 9 is a schematic sectional view showing a first embodiment of the image display device of the present invention. The image display device of the present embodiment is a touch panel type liquid crystal display device. The liquid crystal display device 301 includes a composite front panel 100, a bonding layer 51, a polarizing plate 60a, a touch sensor panel 70, a liquid crystal display element unit 81, a polarizing plate 60b, and a backlight unit 90 in this order from the viewing side. The liquid crystal display device 301 has a display area A and a non-display area B, and includes a colored layer 20 corresponding to the non-display area B in the composite front panel 100.

<Second embodiment>
FIG. 10 is a schematic sectional view showing a second embodiment of the image display device of the present invention. The image display device of the present embodiment is a touch panel type liquid crystal display device. The liquid crystal display device 302 is different from the liquid crystal display device 301 shown in FIG. 9 only in that the lamination positions of the polarizing plate 60a and the touch sensor panel 70 are interchanged.

<Third embodiment>
FIG. 11 is a schematic sectional view showing a third embodiment of the image display device of the present invention. The image display device of the present embodiment is a touch panel type organic electroluminescence (EL) display device. The organic EL display device 303 includes a composite front panel 100, a bonding layer 51, a polarizing plate 60c, a touch sensor panel 70, and an organic EL unit 82 in this order from the viewing side. The organic EL display device 303 has a display area A and a non-display area B, and includes a colored layer 20 corresponding to the non-display area in the composite front panel 100.

<Fourth embodiment>
FIG. 12 is a schematic sectional view showing a fourth embodiment of the image display device of the present invention. The image display device of the present embodiment is a touch panel type organic EL display device. The organic EL display device 304 is different from the organic EL display device 303 shown in FIG. 11 only in that the lamination positions of the polarizing plate 60c and the touch sensor panel 70 are switched.

(Display unit)
Examples of the display unit included in the image display device 300 include a display unit including a display element such as a liquid crystal display element, an organic EL display element, an inorganic EL display element, a plasma display element, and a field emission display element.

  The image display device 300 can be used as a flexible display. In this case, the display element is preferably a liquid crystal display element, an organic EL display element, or an inorganic EL display element because flexibility can be provided.

(Polarizer)
Examples of the polarizing plate include a stretched film on which a dye having absorption anisotropy is adsorbed, and a film containing, as a polarizer, a film coated with a dye having absorption anisotropy and cured. Examples of the dye having absorption anisotropy include dichroic dyes. As the dichroic dye, specifically, iodine or a dichroic organic dye is used. The dichroic organic dyes include dichroic direct dyes composed of disazo compounds such as CI DIRECT RED 39 and dichroic direct dyes composed of compounds such as trisazo and tetrakisazo. Examples of the film to which a dye having absorption anisotropy is applied, which is used as a polarizer, include a stretched film on which a dye having absorption anisotropy is adsorbed, a composition containing a dichroic dye having liquid crystallinity, and A film having a layer obtained by applying and curing a composition containing a colorant and a polymerizable liquid crystal is exemplified. A film coated with a dye having absorption anisotropy and cured is preferable, as compared with a stretched film on which a dye having absorption anisotropy is adsorbed, because there is no restriction on the bending direction.

  Depending on the type of the image display device, the polarizing plate may include a retardation film or a brightness enhancement film. When applied to an organic EL display device, the polarizing plate may be a film composed of a λ / 4 plate and a positive C plate as a retardation film, or a circularly polarizing plate provided with a film composed of a λ / 4 plate and a λ / 2 plate. it can. The retardation film can be formed from a material for forming a protective film described later or a composition containing a polymerizable liquid crystal compound.

(1) Polarizing plate having stretched film as polarizer A polarizing plate having a stretched film on which a dye having absorption anisotropy is adsorbed as a polarizer will be described. A stretched film on which a dye having absorption anisotropy is adsorbed, which is a polarizer, is usually formed by uniaxially stretching a polyvinyl alcohol-based resin film, and dyeing the polyvinyl alcohol-based resin film with a dichroic dye. It is manufactured through a step of adsorbing the dichroic dye, a step of treating the polyvinyl alcohol-based resin film to which the dichroic dye is adsorbed with a boric acid aqueous solution, and a step of washing with water after the treatment with the boric acid aqueous solution. Such a polarizer may be used as it is as a polarizing plate, or one obtained by bonding a transparent protective film on one or both surfaces thereof may be used as a polarizing plate. The thickness of the polarizer thus obtained is preferably 2 μm to 40 μm.

  The polyvinyl alcohol-based resin is obtained by saponifying a polyvinyl acetate-based resin. As the polyvinyl acetate resin, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, a copolymer of vinyl acetate and another monomer copolymerizable therewith is used. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

  The saponification degree of the polyvinyl alcohol-based resin is usually about 85 to 100 mol%, and preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The polymerization degree of the polyvinyl alcohol-based resin is generally about 1,000 to 10,000, and preferably in the range of 1,500 to 5,000.

  A film formed of such a polyvinyl alcohol-based resin is used as a raw film of a polarizing plate. The method of forming the polyvinyl alcohol-based resin is not particularly limited, and the film can be formed by a known method. The thickness of the polyvinyl alcohol-based raw film can be, for example, about 10 μm to 150 μm.

  The uniaxial stretching of the polyvinyl alcohol-based resin film can be performed before, simultaneously with, or after dyeing with the dichroic dye. When the uniaxial stretching is performed after the dyeing, the uniaxial stretching may be performed before the boric acid treatment or may be performed during the boric acid treatment. Moreover, it is also possible to perform uniaxial stretching in these multiple steps. In the uniaxial stretching, the film may be uniaxially stretched between rolls having different peripheral speeds, or may be uniaxially stretched using a hot roll. The uniaxial stretching may be dry stretching in which stretching is performed in the air, or wet stretching in which a polyvinyl alcohol-based resin film is stretched using a solvent while being swollen. The stretching ratio is usually about 3 to 8 times.

  The material of the protective film to be bonded to one or both surfaces of the polarizer is not particularly limited, for example, cyclic polyolefin resin film, triacetyl cellulose, cellulose acetate based resin such as diacetyl cellulose Films known in the art, such as resin films, polyester resin films made of resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, polycarbonate resin films, (meth) acrylic resin films, and polypropylene resin films. Can be mentioned. The thickness of the protective film is usually 300 μm or less, preferably 200 μm or less, more preferably 100 μm or less, and usually 5 μm or more and preferably 20 μm or more from the viewpoint of thinning. . The protective film may or may not have a retardation.

(2) Polarizing plate provided with a film formed of a liquid crystal layer as a polarizer A polarizing plate provided with a film formed of a liquid crystal layer as a polarizer will be described. As a film coated with a dye having absorption anisotropy, which is used as a polarizer, a composition containing a dichroic dye having liquid crystallinity, or a composition containing a dichroic dye and a liquid crystal compound as a base material Films obtained by coating and curing are exemplified. The film may be used as a polarizing plate by peeling the base material or together with the base material, or may be used as a polarizing plate in a configuration having a protective film on one or both surfaces thereof. As the protective film, the same one as the polarizing plate including the above-described stretched film as a polarizer can be used.

  It is preferable that the film obtained by applying and curing a dye having absorption anisotropy is thin, but if it is too thin, the strength tends to decrease and the processability tends to be poor. The thickness of the film is usually 20 μm or less, preferably 5 μm or less, more preferably 0.5 μm or more and 3 μm or less.

  Specific examples of the film obtained by applying the dye having the absorption anisotropy include the films described in JP-A-2013-37353 and JP-A-2013-33249.

(Touch sensor panel)
As long as the touch sensor panel is a sensor capable of detecting a touched position, the detection method is not limited, and a resistance film method, a capacitance coupling method, an optical sensor method, an ultrasonic method, and an electromagnetic induction coupling are used. And a touch sensor panel of a surface acoustic wave type. Since the cost is low, a touch sensor panel of a resistive film type or a capacitive coupling type is preferably used.

  An example of a resistive touch panel is a pair of substrates arranged opposite to each other, an insulating spacer sandwiched between the pair of substrates, and a transparent film provided as a resistive film on the inner front surface of each substrate. It is composed of a conductive film and a touch position detection circuit. In the image display device provided with the resistive touch panel, when the surface of the composite front panel 100 is touched, the opposing resistive film is short-circuited and a current flows through the resistive film. The touch position detection circuit detects the change in the voltage at this time, and the touched position is detected.

  One example of a capacitively-coupled touch sensor panel includes a substrate, a transparent electrode for position detection provided on the entire surface of the substrate, and a touch position detection circuit. In an image display device provided with a capacitive coupling type touch sensor panel, when the surface of the composite front panel 100 is touched, the transparent electrode is grounded via the capacitance of the human body at the touched point. A touch position detection circuit detects grounding of the transparent electrode, and detects a touched position.

[Use of image display device]
The image display device according to the present invention can be used as mobile devices such as smartphones and tablets, televisions, digital photo frames, electronic signs, measuring instruments and instruments, office equipment, medical equipment, computer equipment, and the like. The bending direction of the image display device may be bending with the composite front panel 100 inside or bending with the composite front panel 100 outside. According to the present invention, the degree of freedom in design is higher than in the case where the colored layer 20 is arranged so as to protrude from the surface of the composite front plate 100, and the air can be prevented from being trapped during lamination.

  Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

[Preparation of Colorant-Containing Layer-Forming Composition (Black)]
<Ink component>
Acetylene black 15% by mass
75% by mass of polyester
Glutaric acid dimethyl ester 2.5% by mass
Succinic acid 2% by mass
5.5% by mass of isophorone
<Curing agent>
75% by mass of aliphatic polyisocyanate
Ethyl acetate 25% by mass
<Solvent>
Isophorone <Preparation method>
10 parts by mass of a curing agent and 10 parts by mass of a solvent were added to 100 parts by mass of the ink component, followed by stirring to obtain a colorant-containing layer forming composition (black).

[Preparation of composition for forming protective layer (transparent)]
<Ink component>
90% by mass of polyester
Glutaric acid dimethyl ester 2.5% by mass
Succinic acid 2% by mass
5.5% by mass of isophorone
<Curing agent>
75% by mass of aliphatic polyisocyanate
Ethyl acetate 25% by mass
<Solvent>
Isophorone <Preparation method>
10 parts by mass of a curing agent and 10 parts by mass of a solvent were added to 100 parts by mass of the ink component, followed by stirring to obtain a composition for forming a protective layer.

[Preparation of adhesive layer]
A (meth) acrylic pressure-sensitive adhesive layer (25 μm in thickness) was prepared.

[Preparation of resin composition for forming second resin layer]
An ultraviolet curable acrylic resin composition was prepared.

[Preparation of third resin layer]
A TAC film (25 μm in thickness) was prepared.

[Examples 1 to 5]
<Example 1>
(Preparation of composite front plate)
The composite front panel of Example 1 was manufactured according to the procedures shown in FIGS. Specifically, a PET film (125 μm thick, RFSeries manufactured by SKC HASS) having a size of 210 cm × 279 cm is prepared as the base film 110, and the colorant-containing material prepared above is provided on the surface of the base film 110. Using the composition for forming a layer (black) as an ink, screen printing using a 460-mesh screen was performed, and printing was performed twice so that the coating thickness after drying was 6 μm. Printing with a discharge amount of 3 μm was performed once to form a colored layer 20 composed of a black print layer having a thickness of 15 μm and a width of 25 mm on the entire periphery of the peripheral portion (FIG. 2B).

  A resin composition for forming the first resin layer (containing a polyimide resin) is applied on the surface of the base film 110 on which the colored layer 20 is formed so that the thickness after drying becomes 50 μm, and the thickness is 30 ° C. at 80 ° C. Prebaked for minutes. Thereafter, the base film 110 was peeled off, the display side surface 20b of the colored layer 20 and the display side surface 10b of the resin layer 10 were exposed, and post-baked at 200 ° C. for 30 minutes to obtain the composite front panel 100. (FIG. 2 (d)).

<Example 2>
The composite of Example 2 differs from the composite front panel 100 produced in Example 1 only in that the thickness of the colored layer 20 after drying is 18 μm and the thickness of the first resin layer after drying is 70 μm. A front plate was produced. Regarding the formation of the colored layer 20, in Example 1, printing was performed twice at an ejection amount at which the coating thickness after drying was 6 μm, and then printing was performed once at an ejection amount at which the coating thickness after drying was 3 μm. However, in Example 2, printing was performed three times at a discharge amount at which the coating thickness after drying was 6 μm.

<Example 3>
The composite of Example 3 is different from the composite front plate 100 produced in Example 1 only in that the thickness of the colored layer 20 after drying is 3 μm and the thickness of the first resin layer after drying is 40 μm. A front plate was produced. Regarding the formation of the colored layer 20, in Example 1, printing was performed twice at an ejection amount at which the coating thickness after drying was 6 μm, and then printing was performed once at an ejection amount at which the coating thickness after drying was 3 μm. However, in the third embodiment, printing was performed only once with a discharge amount at which the coating thickness after drying was 3 μm.

<Example 4>
The composite front plate of Example 4 was different from the composite front plate 100 produced in Example 1 only in that the thickness of the colored layer 20 after drying was 2.5 μm. Regarding the formation of the colored layer 20, in Example 1, printing was performed twice at an ejection amount at which the coating thickness after drying was 6 μm, and then printing was performed once at an ejection amount at which the coating thickness after drying was 3 μm. However, in Example 4, printing was performed only once with a discharge amount at which the coating thickness after drying was 2.5 μm.

<Example 5>
The composite front plate of Example 5 was different from the composite front plate 100 produced in Example 1 only in that the thickness of the colored layer 20 after drying was 21 μm. Regarding the formation of the colored layer 20, in Example 1, printing was performed twice at an ejection amount at which the coating thickness after drying was 6 μm, and then printing was performed once at an ejection amount at which the coating thickness after drying was 3 μm. However, in Example 5, after printing was performed three times with the ejection amount at which the coating thickness after drying was 6 μm, printing was performed once with the ejection amount at which the coating thickness after drying was 3 μm.

[Evaluation]
<Air bubbles during bonding>
Since the display front surfaces of the composite front plates of Examples 1 to 5 are flush with each other, no air bubbles are generated when the composite front plates are bonded to another member via the adhesive layer.

<Concave steps on the viewing side>
For the composite front plates of Examples 1 to 5, the viewing side surface was observed with an interferometer microscope (Bruker, Contour GT), and the height of the step (the maximum height) between the display region and the non-display region where the colored layer was formed was determined. And the minimum height). In the composite front plates of Examples 1 to 4, no step was observed. That is, the height of the step was 0 (zero) μm. On the other hand, in the composite front panel of Example 5, a step in which the non-display area was raised compared to the display area was observed, and the height of the step was 4.6 μm. Table 1 shows the evaluation results.

<Measurement of optical density>
With respect to the composite front plates of Examples 1 to 5, an area where the colored layer 20 was formed (non-display area) was cut out into a size of 117 mm × 154 mm to be a sample for optical density measurement. Set this sample on an optical density meter (product name: 361T, manufactured by X-rite), turn on the light source on the viewing side surface of the sample, focus on the colored layer of the sample, and turn off the light source on the top After that, the lower light source located on the display side surface of the sample was turned on, and the optical density was measured using the colored layer as a measurement area. Table 1 shows the measurement results.

[Test Examples 1 to 6]
<Test Example 1>
(Preparation of optical laminate)
Corona treatment was applied to the display side surface of the composite front panel of Example 1 and the surface on the side to which the third resin layer was bonded. Then, the respective layers were laminated so as to be “composite front plate / adhesive layer / third resin layer of Example 1”, bonded using a roll bonding machine, and cured in an autoclave. An optical laminate of Test Example 1 having the same configuration as the optical laminate 202 shown was obtained.

<Test Example 2>
An optical laminated body identical to the optical laminated body 202 of Test Example 1 was prepared, and then a resin composition for forming a second resin layer was applied to the viewing side surface of the optical laminated body 202 and cured by irradiating ultraviolet rays. A second resin layer having a thickness of 10 μm was formed, and a test having the same configuration as the optical laminate 203 shown in FIG. 5 consisting of “second resin layer / composite front plate of Example 1 / adhesive layer / third resin layer” An optical laminate of Example 2 was obtained.

<Test Example 3>
460 mesh using a colorant-containing layer forming composition (black) as an ink at a position corresponding to the colored layer 20 on the display side surface of the composite front panel of Example 1 so as to have the same width as the colored layer 20. A screen printing using a screen is performed once with a discharge amount such that the coating thickness after drying becomes 3 μm, and a shielding layer 25 made of a black printing layer having a thickness of 3 μm and a width of 25 mm is formed on the entire periphery of the peripheral portion. The optical laminated body 501 having the configuration shown in FIG. 13 was obtained.

  The corona treatment was performed on the display side surface of the obtained optical laminate 501 and the surface on the side where the third resin layer was bonded. Then, the respective layers are laminated so as to be “optical laminated body 501 / adhesive layer / third resin layer”, bonded by using a roll bonding machine, cured by auto grading, and shown in FIG. An optical laminate 503 was obtained.

  A resin composition for forming a second resin layer is applied to the visible side surface of the obtained optical laminate 503, and cured by irradiating ultraviolet rays to form a second resin layer having a thickness of 10 μm. An optical laminate of Test Example 3 having the same configuration as the optical laminate 504 shown in FIG. 16 and consisting of “/ optical laminate 501 / adhesive layer / third resin layer” was obtained.

<Test Example 4>
A front plate different from the composite front plate 100 prepared in Example 1 only in that it did not have the coloring layer 20 was prepared. Specifically, without performing the step of forming the colored layer 20, the thickness of the resin composition (containing the polyimide resin) for forming the first resin layer on the surface of the base film 110 is 50 μm after drying. And baked at 80 ° C. for 30 minutes. Thereafter, the base film 110 was peeled off, the display side surface 10b of the resin layer 10 was exposed, and post-baked at 200 ° C. for 30 minutes to obtain a front plate used in Test Example 4.

  On the display side surface of such a front plate, a colorant-containing layer forming composition (black) was used as an ink by screen printing using a 460-mesh screen to print an ejection amount at which the coating thickness after drying was 6 μm. The printing is performed once, and then the printing is performed once so that the coating thickness after drying becomes 3 μm, and a shielding layer 25 made of a black printing layer having a thickness of 15 μm and a width of 25 mm is formed on the entire periphery of the peripheral portion to form an optical layer. A laminate was obtained.

  The display side surface of the obtained optical laminated body and the surface on the side where the third resin layer is bonded were subjected to corona treatment. Then, the respective layers are laminated so as to be “front plate (on which a shielding layer is formed) / adhesive layer / third resin layer”, bonded using a roll bonding machine, and cured with an auto grave. Was performed to obtain an optical laminate.

  A resin composition for forming a second resin layer is applied to the visible side surface of the obtained optical laminate, and cured by irradiating ultraviolet rays to form a second resin layer having a thickness of 10 μm. An optical laminate of Test Example 3 consisting of "front plate (on which shielding layer is formed) / adhesive layer / third resin layer" was obtained. The optical laminate of Test Example 3 has no colored layer.

<Test Example 5>
It differs from the optical laminate of Test Example 2 only in the thickness of the colored layer in the composite front plate. Specifically, in Test Example 2, an optical laminate was produced using the composite front plate 100 of Example 1, whereas in Test Example 5, an optical laminate was produced using the composite front plate 100 of Example 5. Produced.

<Test Example 6>
The optical laminate of Test Example 3 is different from the optical laminate of Test Example 3 in the thickness of the first resin layer 10 in the composite front panel, the thickness of the coloring layer 20, and the thickness of the shielding layer 25. Specifically, in Test Example 3, an optical laminate was manufactured using the composite front plate 100 of Example 1, whereas in Test Example 6, the thickness of the first resin layer 10 was 60 μm, and Used was a composite front plate having a thickness of 12 μm. At the time of manufacturing the composite front plate, the colored layer 20 was formed by performing printing twice at a discharge amount at which the coating thickness after drying was 6 μm.

  A colorant-containing layer forming composition (black) is used as an ink at a position corresponding to the colored layer 20 on the display side surface of such a composite front panel using a 460 mesh screen so as to have the same width. By performing screen printing once, printing is performed at an ejection amount such that the coating thickness after drying becomes 6 μm, and a shielding layer 25 made of a black printing layer having a thickness of 6 μm and a width of 25 mm is formed on the entire periphery of the periphery. 13 was obtained.

  The corona treatment was performed on the display side surface of the obtained optical laminate 501 and the surface on the side where the third resin layer was bonded. Then, the respective layers are laminated so as to be “optical laminated body 501 / adhesive layer / third resin layer”, bonded by using a roll bonding machine, cured by auto grading, and shown in FIG. An optical laminate 503 was obtained.

  A resin composition for forming a second resin layer is applied to the visible side surface of the obtained optical laminate 503, and cured by irradiating ultraviolet rays to form a second resin layer having a thickness of 10 μm. The optical laminate of Test Example 6 having the same configuration as the optical laminate 504 shown in FIG. 16 and consisting of “/ optical laminate 501 / adhesive layer / third resin layer” was obtained.

[Evaluation]
<Air bubbles on the surface of the adhesive layer>
With respect to the optical laminates of Test Examples 1 to 6, the surface of the pressure-sensitive adhesive layer on the composite front plate side was observed with an optical microscope (manufactured by Olympus Corporation), and the generation of bubbles was evaluated according to the following criteria. Table 2 shows the evaluation results.
A: No bubbles were observed,
B: Air bubbles were observed only around the colored layer (non-display area),
C: Bubbles were observed around the colored layer (non-display area) and other areas (display area).

<Concave steps on the viewing side>
With respect to the optical laminates of Test Examples 1 to 6, the viewing side surface was observed with an interferometer microscope (Bruker, Contour GT), and the height of the step (the maximum height) between the display region and the non-display region where the colored layer was formed was determined. And the minimum height). In the optical laminates of Test Examples 1 to 3, no step was observed. That is, the height of the step was 0 (zero) μm. Table 2 shows the evaluation results.

<Measurement of optical density>
A region (non-display region) where the colored layer 20 was formed was cut out from the optical laminates of Test Examples 1 to 6 in a size of 117 mm × 154 mm to obtain a sample for optical density measurement. Set this sample on an optical density meter (product name: 361T, manufactured by X-rite), turn on the light source on the surface on the viewing side of the sample, and turn on the colored layer of the sample (if a shielding layer is formed). Focuses on the composite layer consisting of the colored layer and the shielding layer, turns off the upper light source, and then turns on the lower light source located on the display side surface of the sample. The optical density was measured using a composite layer composed of a colored layer and a shielding layer as a measurement area. Table 2 shows the measurement results.

  Reference Signs List 10 first resin layer, 20 coloring layer, 25 shielding layer, 30 second resin layer, 40 third resin layer, 50, 51 bonding layer, 60 a, 60 b, 60 c polarizing plate, 70 touch sensor panel, 81 liquid crystal display unit , 82 organic EL display unit, 90 backlight unit, 100 composite front panel, 100 ′ composite front panel sheet, 100a viewing side surface, 100b display side surface, 110 base film, 201, 202, 203 optical laminate, 300 image Display device, 301, 302 Liquid crystal display device, 303, 304 Organic EL display device, 305, 306 Flexible display, 400 display laminate, 501, 502, 503 Optical laminate, A display area, B non-display area.

Claims (10)

A composite front plate used by being arranged on the front side of the image display device,
Having a first resin layer and a coloring layer provided on a part thereof,
The viewing side surface is a plane configured by the viewing side surface of the first resin layer,
The composite front panel, wherein the display side surface is a plane formed by the display side surface of the first resin layer and the display side surface of the colored layer.   The composite front panel according to claim 1, wherein the coloring layer includes a binder resin. When the thickness of the first resin layer is a (μm) and the thickness of the coloring layer is b (μm), the thickness ratio T1 (%) calculated by the following equation (1) is represented by the following equation (2a). The composite front panel according to claim 1 or 2, which satisfies the following relationship.
T1 = b / a × 100 (1)
5 ≦ T1 ≦ 42 (2a)   An optical laminate comprising: the composite front panel according to any one of claims 1 to 3; and a shielding layer laminated at a position corresponding to the coloring layer on the display-side surface of the composite front panel.   The optical laminate according to claim 4, wherein the thickness of the shielding layer is 12 μm or less. In the optical laminate, when the thickness of the first resin layer is a (μm), the thickness of the coloring layer is b (μm), and the thickness of the shielding layer is c (μm), the following formula (3) is used. The optical laminate according to claim 4 or 5, wherein the calculated thickness ratio T2 (%) satisfies the relationship of the following expression (4a).
T2 = (b + c) / a × 100 (3)
T2 ≧ 30 (4a) A composite front panel according to any one of claims 1 to 3,
An optical laminate comprising: a second resin layer laminated on the viewing side surface of the composite front panel; and at least one of a third resin layer laminated on the display side surface of the composite front panel. Having the third resin layer laminated on the display side surface of the composite front panel via an adhesive layer,
The optical laminate according to claim 7, wherein a thickness of the pressure-sensitive adhesive layer is 2 μm to 25 μm.   An image display device comprising the composite front panel according to any one of claims 1 to 3, which is disposed on a front side. It is a manufacturing method of the composite front plate as described in any one of Claims 1-3,
Forming the colored layer on a part of the substrate film,
A step of applying a resin layer-forming composition on the base film so as to cover the visible side surface of the colored layer, and drying to form the first resin layer;
Peeling the base film.

Images