KR20210005064A - Optical laminate and its manufacturing method - Google Patents

Abstract

An object of the present invention is to provide an optical laminate having a colored layer and having durability against warpage. An optical laminate comprising a front plate, a bonding layer, and a back plate in this order, further comprising a colored layer provided on a part of the surface of the rear plate on the bonding layer side.

Description

Optical laminate and its manufacturing method

The present invention relates to an optical laminate and a method of manufacturing the same, and also to an image display device and a polarizing plate having a colored layer.

BACKGROUND ART As various image display devices such as a liquid crystal display device and an organic electroluminescent display device, there is known a configuration in which a front plate is provided on the visible side of the display panel for the purpose of protecting the display panel. When the display panel is a touch panel, the front panel may also function as a touch surface.

In Japanese Patent Laid-Open No. 2014-238533 (Patent Document 1), it is described that a front plate is provided on the viewer side of a display panel of an image display device, and in the peripheral portion of the surface of the display panel side of the front plate as a colored layer It is described to provide a printing layer. The colored layer also functions as a shielding layer forming a non-display area of the image display device.

Patent Document 1: Japanese Patent Laid-Open No. 2014-238533

In recent years, expectations for flexible image display devices are increasing. The flexible image display device can be installed on a non-planar surface or a bent surface, and can be folded or rolled into a winding shape when carrying, thereby improving portability.

In order to construct a flexible image display device, it is required to have durability against bending for each component. With respect to the colored layer, cracks and discoloration may occur by repeating warping, and there was a problem that durability against warping was not sufficient.

The present invention provides an optical laminate having a colored layer and having durability against warpage, an image display device having the optical laminate, a polarizing plate having a colored layer having the colored layer, and a method of manufacturing the optical laminate It aims to provide.

The present invention provides an optical laminate shown below, an image display device, a polarizing plate having a colored layer, and a method for producing an optical laminate.

[1] As an optical laminate comprising a front plate, a bonding layer, and a back plate in this order,

The optical laminated body further comprising a colored layer provided on a part of the surface of the rear plate on the bonding layer side.

[2] The optical laminate according to [1], in which the thickness of the colored layer is 3 μm or more.

[3] The optical laminate according to [1] or [2], in which the front plate is a resin film.

[4] The optical laminate according to any one of [1] to [3], in which the back plate has a polarizing plate.

[5] An image display device comprising the optical laminate according to any one of [1] to [4], and wherein the front plate is disposed on a front surface.

[6] 　 a polarizing plate, and

A polarizing plate having a colored layer, comprising a colored layer provided on a part of the surface on the viewing side of the polarizing plate.

[7] As a manufacturing method for manufacturing the optical laminate according to any one of [1] to [4],

A colored layer forming step of forming the colored layer on a part of the outermost layer on the side of the bonding layer of the back plate, and

A manufacturing method having a lamination step of laminating the bonding layer on the outermost layer after the colored layer forming step.

[8] As an optical laminate comprising a front plate, a bonding layer, and a back plate in this order,

Further comprising a colored layer provided on a part of the surface of the back plate on the bonding layer side,

The colored layer comprises a plating layer, the optical laminate.

[9] The optical laminate according to [8], wherein the colored layer further includes a protective layer covering the plating layer.

[10] The optical laminate according to [8] or [9], wherein the colored layer further has a base layer covered with the plating layer.

[11] The optical laminate according to [10], wherein the base layer contains a black pigment.

[12] The optical laminate according to any one of [8] to [11], wherein the colored layer has a thickness of 1 µm or more and 30 µm or less.

[13] 　 The optical laminate is divided into a display area and a non-display area in a plane direction orthogonal to the stacking direction,

The colored layer is provided in the non-display area,

The optical laminate according to any one of [8] to [12], wherein the non-display region has an optical density of 3 or more.

[14] 　 The optical laminated body according to any one of [8] to [13], wherein the front plate is a resin film.

[15] The optical laminate according to any one of [8] to [14], in which the back plate has a polarizing plate.

[16] An image display device comprising the optical laminate according to any one of [8] to [15], and wherein the front plate is disposed on the entire surface.

[17] 　 a polarizing plate, and

And a colored layer provided on a part of the surface of the polarizing plate on the viewing side,

The colored layer has a plating layer, and a polarizing plate having a colored layer.

[18] As a method of manufacturing the optical laminate according to any one of [8] to [15],

A manufacturing method having a colored layer forming step of forming the colored layer on a part of the outermost layer on the side of the bonding layer of the back plate, and a lamination step of laminating the bonding layer on the outermost layer after the colored layer forming step .

According to the present invention, an optical laminate having a colored layer and having durability against warping, an image display device having the optical laminate, a polarizing plate having a colored layer having the colored layer, and manufacturing the optical laminate Can provide a way.

1 is a schematic cross-sectional view of an optical laminate according to an embodiment of the present invention.
2 is a schematic cross-sectional view of an image display device according to an embodiment of the present invention.
3 is a top view of the optical laminate as viewed from the front plate side.
FIG. 4 is a diagram illustrating an example of a bending form when the image display device is a flexible display.
5 is a schematic cross-sectional view of an image display device according to a first embodiment of the present invention.
6 is a schematic cross-sectional view of an image display device according to a second embodiment of the present invention.
7 is a schematic cross-sectional view of an image display device according to a third embodiment of the present invention.
8 is a schematic cross-sectional view of an image display device according to a fourth embodiment of the present invention.
9 is a cross-sectional view schematically showing an example of a method for manufacturing an optical laminate of the present invention.
10 is a diagram schematically showing a test method for evaluating the flexibility.
11 is a cross-sectional view schematically showing a method of manufacturing an optical laminate in Example 1. FIG.
12 is a cross-sectional view schematically showing a method of manufacturing an optical laminate in Comparative Example 1. FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. In all the drawings below, the scale is appropriately adjusted to make each component easier to understand, and the scale of each component shown in the drawings does not necessarily coincide with the scale of the actual component.

[Optical laminate]

1 is a schematic cross-sectional view of an optical laminate according to an embodiment of the present invention. The optical laminated body 100 of this embodiment is provided with the front plate 10, the bonding layer 20, and the back plate 30 in order from the viewer side. The optical laminate 100 includes a colored layer 40, and the colored layer 40 is provided on a part of the rear plate 30 on the surface of the bonding layer 20 side. The optical laminate 100 may be divided into a display area A and a non-display area B in a plane direction orthogonal to the stacking direction, and in this case, it is preferable to provide a colored layer 40 in the non-display area B. . In addition, below, the case where the optical laminated body 100 is divided into a display area A and a non-display area B, and the non-display area B includes the colored layer 40 will be described as an example.

[Image display device]

2 is a schematic cross-sectional view of an image display device according to an embodiment of the present invention. The image display device 300 of the present embodiment includes an optical laminate 100 including a front plate 10 disposed on the front surface, and a display laminate 200 including a display unit.

3 is a top view of the image display device 300 as viewed from the front plate 10 side. The non-display area B preferably has an optical density of 3 or more, and more preferably 3.2 or more. When the optical density of the non-display area B is within the above numerical range, elements such as wiring arranged in the non-display area B are sufficiently shielded, and the visibility of the image in the display area A is improved. The colored layer 40 contributes to the improvement of the optical density of the non-display area B. In addition, since the shape and color of the colored layer 40 is visually recognized through the bonding layer 20 and the front plate 10, the colored layer 40 also contributes to the design of the image display device 300. The colored layer 40 of the present invention may contain a metal, and when it contains a metal, the reflected light from the metal is visually recognized as the color of the colored layer 40, thus contributing to a design having a sense of quality.

The shape and size of the optical laminate 100 in the plane direction corresponds to the shape and size of the image display device 300 in which it 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 a rectangle. 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, 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 optical laminated body 100 has a square shape, at least one type of processing consisting of R processing, notch processing, and drilling processing may be performed.

The thickness of the optical laminate 100 is preferably designed appropriately according to the functions of the front plate 10 and the rear plate 30, and is not particularly limited, but is, for example, 40 μm to 300 μm, Preferably it is 70㎛ ~ 200㎛.

It is preferable that the optical laminated body 100 is foldable. Being bendable means that good results are obtained in a bending test with a bending curvature of 2.5R. In the optical layered product according to a preferred embodiment of the present invention, good results are obtained in a bending test having a bending curvature of 2.5 R. The bending test with a bending curvature of 2.5 R is performed according to the method described in Examples to be described later.

The image display device 300 can be configured as a flexible display panel. Fig. 4 shows an example of a bending form when the image display device is a flexible display panel. FIG. 4(a) is a flexible display 305 configured to fold the view-side surface inward, and FIG. 4(b) is a flexible display 306 that can be wound.

When the image display device 300 is a flexible display, cracks or discoloration may be caused by repeatedly applying a bending force to the colored layer 40 or continuously applying a bending force. In the image display device 300, if a crack or discoloration occurs in the colored layer 40, it is not preferable because it is easily visually recognized. In addition, regardless of whether the image display device 300 is a flexible display or not, when the optical laminate 100 alone has flexibility, there is a case where a bending force is applied even when the optical laminate 100 is transported. Therefore, it may cause cracks or discoloration in the colored layer 40.

In the optical laminate 100 and the image display device 300 of the present invention, the stacking position of the colored layer 40 is on the surface of the bonding layer 20 side of the rear plate 30, and the bending force is repeated or Even if it is added continuously, occurrence of cracks and discoloration in the colored layer 40 can be suppressed. The optical laminated body 100 and the image display device 300 of the present invention, the colored layer 40 for the bending force with the front plate 10 inwardly and the bending force with the front plate 10 inwardly. ) Can prevent cracks or discoloration. Compared to the case where the colored layer 40 is disposed on the surface of the front plate 10, the stacking position of the colored layer 40 can be approached to the center in the stacking direction of the optical laminate 100.

For this reason, it is considered that the stress generated in the colored layer 40 due to bending is small, and the above effect is exhibited.

Based on this point of view, the distance d1 from the surface of the colored layer 40 on the side close to the front plate 10 to the outermost surface of the optical laminate 100 on the front plate 10 side (Fig. And the distance d2 from the surface of the colored layer 40 on the far side from the front plate 10 to the outermost surface of the optical laminate 100 on the rear plate 30 side (shown in FIG. 1) The size of the difference may be 0 µm or more and 50 µm or less, and preferably 30 µm or less.

The relative size D (%) of the difference between the distance d1 and the distance d2 is preferably 25% or less, more preferably 20% or less, and more preferably 15% or less. The lower limit is not particularly limited, and may be 0%. The relative magnitude D (%) of the difference is the following equation:

D=100×|(d1-d2)/(d1+d2)|

Is calculated from

The image display device 300 can be configured as a touch panel type image display device. A touch panel type image display device includes a touch sensor panel, and the front plate 10 provided in the optical laminate 100 constitutes a touch surface.

Hereinafter, a specific form (first to fourth embodiments) of the image display device according to the present invention will be shown, and each component will be described in detail.

<First embodiment>

5 is a schematic cross-sectional view of an image display device according to a first embodiment of the present invention. The image display device of this embodiment is a touch panel type liquid crystal display device. The liquid crystal display device 301 is, in order from the viewer side, a front plate 10, a bonding layer 20, a polarizing plate 60a, a touch sensor panel 70, a liquid crystal display element unit 81, and a polarizing plate 60b. , And a backlight unit 90. The liquid crystal display device 301 includes a colored layer 40 provided on a part of the surface of the polarizing plate 60a on the bonding layer 20 side. The liquid crystal display device 301 may be divided into a display area A and a non-display area B in the plane direction, and in this case, it is preferable to provide a colored layer 40 in the non-display area B.

In the liquid crystal display device 301, a laminate comprising a front plate 10, a bonding layer 20, and a polarizing plate 60a, and having a colored layer 40 is constituted as an optical laminate 101, such as A liquid crystal display device 301 is configured by using the optical laminate 101. In this embodiment, the polarizing plate 60a also functions as the rear plate 30 of the optical laminate 101.

<2nd embodiment>

6 is a schematic cross-sectional view of an image display device according to a second embodiment of the present invention. The image display device of this embodiment is a touch panel type liquid crystal display device. In the liquid crystal display device 302, the stacking position of the polarizing plate 60a and the touch sensor panel 70 is changed from that of the liquid crystal display device 301 shown in FIG. 5, so that the colored layer 40 is formed of the touch sensor panel 70. It differs only in that it is provided on the surface of the bonding layer 20 side.

In the liquid crystal display device 302, a laminate comprising a front plate 10, a bonding layer 20, and a touch sensor panel 70, and a laminate having a colored layer 40 is configured as an optical laminate 102, , A liquid crystal display device 302 is configured using the optical laminate 102. In this embodiment, the touch sensor panel 70 also functions as the back plate 30 of the optical laminate 102.

<3rd embodiment>

7 is a schematic cross-sectional view of an image display device according to a third embodiment of the present invention. The image display device of this embodiment is a touch panel type organic electroluminescent (EL) display device. The organic EL display device 303 includes a front plate 10, a bonding layer 20, a polarizing plate 60c, a touch sensor panel 70, and an organic EL unit 82 in order from the viewing side. The organic EL display device 303 includes a colored layer 40 provided on a part of the surface of the polarizing plate 60c on the bonding layer 20 side. The organic EL display device 303 may be divided into a display area A and a non-display area B in the plane direction, and in this case, it is preferable to provide the colored layer 40 in the non-display area B.

In the organic EL display device 303, a laminate comprising the front plate 10, the bonding layer 20, and the polarizing plate 60c, and the colored layer 40 is constituted by the optical laminate 103, An organic EL display device 303 is constructed using such an optical laminate 103. In this embodiment, the polarizing plate 60c also functions as the rear plate 30 of the optical laminate 103.

<4th embodiment>

8 is a schematic cross-sectional view of an image display device according to a fourth embodiment of the present invention. The image display device of this embodiment is an organic EL display device of a touch panel system. In the organic EL display device 304, the stacking position of the polarizing plate 60c and the touch sensor panel 70 is changed from that of the organic EL display device 303 shown in FIG. 7, so that the colored layer 40 is It differs only in that it is provided on the surface of the bonding layer 20 side of 70).

In the organic EL display device 304, a laminate comprising a front plate 10, a bonding layer 20, and a touch sensor panel 70, and a multilayer body having a colored layer 40 is configured as an optical laminate 104 Then, the organic EL display device 304 is constituted by using the optical laminate 104. In this embodiment, the touch sensor panel 70 also functions as the back plate 30 of the optical laminate 104.

(Display unit)

Examples of the display units included in the image display device 300 include display units including display elements 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. have.

The image display device 300 can be used as a flexible display. In this case, it is preferable that the display element is a liquid crystal display element, an organic EL display element, or an inorganic EL display element from the viewpoint of providing flexibility.

(Front panel)

The front plate 10 is not limited in material and thickness as long as it is a plate-like body capable of transmitting light, and may be a single layer or a multi-layered body, and a plate-like body made of glass (for example, a glass plate, a glass film, etc.), made of resin. The plate-shaped body (for example, a resin plate, a resin sheet, a resin film, etc.) is illustrated.

As the glass plate, tempered glass for displays is preferably used. The thickness of the glass plate is, for example, 50 µm to 1000 µm. By using a glass plate, the front plate 10 having excellent mechanical strength and surface hardness can be configured.

The resin film is not limited as long as it is a resin film that 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, Polyethersulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyether sulfone, polymethyl methacrylic And films formed of polymers such as polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, and polyamideimide. These polymers can be used alone or in combination of two or more. When the image display device 300 is a flexible display, a resin film formed of a polymer such as polyimide, polyamide, and polyamideimide, which can be configured to have excellent flexibility, high strength, and high transparency, is formed. It is used suitably.

The resin film may be a film in which hardness is further improved by providing a hard coat layer on at least one surface of the base film. The hard coat layer may be formed on one surface of the base film or may be formed on both surfaces. When the image display device 300 is a touch panel type image display device, since the surface of the front plate 10 becomes a touch surface, a resin film having a hard coat layer is suitably used. By providing a hard coat layer, it can be set as the resin film which improved hardness and scratch property. The hard coat layer is, for example, a cured layer of an ultraviolet curable resin. Examples of the ultraviolet-curable resin include acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, and epoxy resins. The hard coat layer may contain an additive in order to improve strength. The additive is not limited, and inorganic fine particles, organic fine particles, or mixtures thereof are exemplified. The thickness of the resin film is, for example, 30 µm to 2000 µm.

The front plate 10 may not only have a function of protecting the front surface of the image display device 300, but may also have a function as a touch sensor, a blue light cut function, a viewing angle adjustment function, and the like.

The thickness of the front plate 10 may be 10 ~ 500㎛, preferably 20 ~ 100㎛. When the front plate has a hard coat layer, the thickness of the front plate also includes the thickness of the hard coat layer.

(Lamination layer)

The bonding layer 20 is a layer interposed between the front plate 10 and the rear plate 30 to bond them, and is an adhesive layer or an adhesive layer. It is preferable that the bonding layer 20 is an adhesive layer from the viewpoint of being able to absorb the level difference of the colored layer 40 satisfactorily.

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

As the (meth)acrylic resin (base polymer) used in the pressure-sensitive adhesive composition, for example, (meth)acrylic acid butyl, (meth)acrylate ethyl, (meth)acrylate isooctyl, (meth)acrylate 2-ethylhexyl, such as ( Polymers or copolymers containing one or two or more kinds of meth)acrylic esters as monomers are suitably used. It is preferable to copolymerize a polar monomer to the base polymer. As a polar monomer, for example, (meth)acrylic acid, (meth)acrylic acid 2-hydroxypropyl, (meth)acrylic acid hydroxyethyl, (meth)acrylamide, N,N-dimethyl aminoethyl (meth)acrylate , Monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group, and the like, such as glycidyl (meth)acrylate.

The pressure-sensitive adhesive composition may contain only the base polymer, but usually further contains a crosslinking agent. Examples of the crosslinking agent include divalent or higher metal ions, and forming a carboxylic acid metal salt between a carboxyl group; As a polyamine compound, forming an amide bond between a carboxyl group; A polyepoxy compound or a polyol that forms an ester bond between a carboxyl group; As a polyisocyanate compound, what forms an amide bond between a carboxyl group is illustrated. Among them, polyisocyanate compounds are preferable.

The active energy ray-curable pressure-sensitive adhesive composition has a property of curing by irradiation with active energy rays such as ultraviolet rays or electron beams, so it has adhesiveness before active energy ray irradiation and can adhere to an adherend such as a film, and is cured by irradiation with active energy rays. It is a pressure-sensitive adhesive composition having a property that can adjust the adhesive force. It is preferable that an active energy ray-curable pressure-sensitive adhesive composition is 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, or 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 or other inorganic powders, etc.), antioxidants, Additives such as an ultraviolet absorber, a dye, a pigment, a colorant, a defoaming agent, a corrosion inhibitor, and a photopolymerization initiator may be included.

It can be formed by applying a diluent of the organic solvent of the pressure-sensitive adhesive composition on a substrate and drying it. When an 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 an active energy ray.

The thickness of the bonding layer 20 is preferably thicker than the thickness of the colored layer 40 from the viewpoint of absorbing the step difference of the colored layer 40, for example, it is preferably 3 μm to 100 μm, and 5 μm It is more preferably ~ 50㎛.

(Back panel)

The material and thickness of the back plate 30 are not limited as long as it is a plate-like body capable of transmitting light, and may be a single layer or a multilayer. The thickness of the back plate may be 10 μm to 1000 μm, preferably 20 μm to 500 μm, and more preferably 50 μm to 100 μm. The display unit may not be included in the rear plate.

As the rear plate 30, as described above, components used in a typical image display device, such as polarizing plates 60a and 60c, and touch sensor panel 70, can be used. Using these components as the rear plate 30 is preferable because the number of components of the image display device 300 can be reduced, and thus the thickness of the image display device 300 can be realized.

In the above, the case where the back plate 30 is also the polarizing plates 60a and 60c and the touch sensor panel 70 was illustrated, but the back plate 30 is not limited to these, and the protective film on the visible side of the polarizing plate Or it may be a laminate of a polarizing plate and a touch sensor panel.

As the back plate 30, like the front plate 10, a plate-like body made of glass (for example, a glass plate, a glass film, etc.), a plate-like body made of resin (for example, a resin plate, a resin sheet, and a resin film) Etc.) can also be used. As a specific example of the glass-made plate-shaped body and the resin-made plate-shaped body, the description mentioned above regarding the front plate 10 is applied.

(Colored layer)

The shape and color of the colored layer 40 are not limited and can be appropriately selected according to the use or design. As the colored layer 40, a layer colored in a color such as black, red, white, dark blue, silver or gold can be illustrated. The colored layer 40 may be formed in a single layer or in a plurality of layers. When the colored layer 40 is formed from a plurality of layers, as the color of the colored layer 40, one type of color may be employed or a plurality of colors may be employed. The colored layer 40 may contain a metal, and such a metal may be contained in the plating layer.

The colored layer 40 can be formed by a printing method using an ink or a paint, a method of forming a colored layer 40 containing a metallic pigment in advance, and bonding them. Moreover, you may combine these methods. It is preferable to form the colored layer 40 on the surface of the back plate 30. Specific examples of the printing method include gravure printing, offset printing, screen printing, and transfer printing from a transfer sheet. Printing according to the printing method may be repeatedly performed to obtain the colored layer 40 having a desired thickness. The ink or paint used to form the colored layer 40 contains, for example, a binder, a colorant, a solvent, and optional additives.

Examples of the binder include chlorinated polyolefin (eg, chlorinated polyethylene, chlorinated polypropylene), polyester resin, urethane resin, acrylic resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer, and cellulose resin. Binder resins may be used alone or in combination of two or more. The binder resin may be a thermally polymerizable resin or a photopolymerizable resin.

The colorant may be appropriately selected depending on the desired coloration. Examples of the colorant include inorganic pigments such as titanium white, zincated, carbon black, iron black, bengala, chrome vermilion, ultramarine, cobalt blue, yellow lead, and titanium yellow; Organic pigments or dyes such as phthalocyanine blue, indusrene blue, isoindolinone yellow, benzidine yellow, quinacridone red, polyazo red, perylene red, and aniline black; Metallic pigments made of scale flakes such as aluminum and brass; And pearlescent pigments (pearl pigments) made of scaly flakes such as titanium dioxide-coated mica and basic lead carbonate. 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 colored layer 40 is preferably 1 µm to 50 µm, more preferably 3 µm to 30 µm, and 3 µm to 20 µm, from the viewpoint of improving the shielding effect while suppressing visible steps. It may be µm. When the colored layer 40 is black, a high shielding effect can be obtained compared to other colors even if the thickness is thin. In Fig. 1, a case in which the thickness of the colored layer 40 is uniform and the cross-sectional shape is rectangular is illustrated, but the thickness of the colored layer 40 does not need to be uniform, for example, a taper that decreases in thickness toward the inside. It may be a cross-sectional shape having a portion. By having a tapered portion, it is possible to suppress mixing of air that is likely to occur during lamination. When the thickness of the colored layer 40 is not uniform, the numerical range described above as the thickness of the colored layer 40 is the maximum thickness of the colored layer 40. It is preferable that the colored layer 40 has an appropriate elastic force from the viewpoint of suppressing a visible step difference. The elastic force of the colored layer 40 can be adjusted according to the type of binder to be used, the mixing ratio, and the like.

When the colored layer 40 is provided on the periphery of the rear plate 30, it is not limited to a form provided on all sides of the periphery, and may be provided only on a part of the periphery according to a desired design or the like. When the colored layer 40 is provided on the periphery of the rear plate 30, the width can be appropriately determined according to the size of the display area, a desired design, etc., for example, in the range of 1 mm to 20 mm. desirable.

As long as the colored layer 40 is provided on a part on the surface of the bonding layer 20 side of the back plate 30, the arrangement position in the surface direction is not limited. In the case of a configuration in which the colored layer 40 is disposed at the periphery, as in the image display device 300 shown in Figs. 2 and 3, light leakage from the periphery can be suppressed, and design is possible in that it is visually recognized like a frame. Can improve.

When the colored layer 40 contains a metal, it is preferable that such a metal is included as a plating layer. The colored layer 40 is a form containing a metal, and a form in which a metallic pigment is included in the printing layer or coating layer is also possible, but the present inventors believe that the plating layer is not warped compared to the printing layer or the coating layer containing the metallic pigment. The knowledge that the durability of the seaweed is higher was obtained. Therefore, when the colored layer 40 contains a metal, it contributes to the improvement of durability against warpage by setting it as the structure which contains a metal as a plating layer.

When the colored layer 40 includes a plating layer, the thickness of the colored layer 40 is preferably 30 μm or less, and more preferably 15 μm or less. Since the thickness of the colored layer 40 is within the above numerical range, durability against warpage can be improved. The thickness of the colored layer 40 is preferably 3 μm or more, and more preferably 6 μm or more. When the thickness of the colored layer 40 is 3 μm or more, the colored layer 40a is easily visually recognized, contributing to improvement in design, and also contributing to improvement in the optical density of the non-display area B.

The optical laminated body 100 may be provided with a shielding layer on the surface of the rear plate 30 on the side opposite to the surface of the bonding layer 20 side, apart from the colored layer 40. The shielding layer can be provided in the non-display area B of the optical laminate 100 and is preferably provided on the colored layer 40 through the rear plate 30. The shielding layer contributes to the improvement of the optical density of the non-display area B. Therefore, when the optical density of the non-display area B does not reach a desired value only in the colored layer 40, it is preferable to provide a shielding layer.

In this specification, the layer formed by the plating method is referred to as a plating layer. Therefore, on the surface of the rear plate 30 or on the surface of the base layer formed on the surface of the rear plate 30, even if it is a plated layer formed by the direct plating method, a layer including the plated layer formed on the substrate is deposited on the surface of the rear plate 30 Even if it is a plated layer formed by transferring, it is included in the plated layer defined in this specification. The plating layer formed by the direct plating method is preferable because it has higher durability against warpage. In addition, in the case of forming the colored layer 40 by transferring to the surface of the rear plate 30, for example, a thermal transfer method may be employed, but according to the thermal transfer method, the rear plate 30 is deformed and size changed by heat. Since, etc. may occur, the direct plating method is also preferable from this point.

As a specific example of the plating method, known plating methods, such as electrolytic plating, electroless plating, hot dip plating, chemical vapor deposition, and physical vapor deposition, are mentioned. Examples of the physical vapor deposition include an evaporation system including a method of heating and evaporating an evaporation source such as vacuum vapor deposition, molecular beam vapor deposition, and ion beam vapor deposition, and sputtering systems such as magnetron sputtering and ion beam sputtering. In the present specification, examples of the metal constituting the plating layer include Al ₂ O ₃ , TiO ₂ , SiO ₂ , In, and the like.

The formation of the plating layer can be configured to obtain a desired shape by combining patterning. By performing patterning, a plating layer can be provided on a part of the surface of the rear plate 30 on the bonding layer 20 side. For this reason, since the plating layer formed in the display area A can be removed, for example, the distinction between the non-display area B and the display area A can be clarified, and the visibility of the display area A can be improved. In the case of forming the plating layer according to the direct plating method, as a specific method of patterning,

i) After the plating layer is formed on the entire surface of the back plate 30, the transparent protective layer is covered only in the area corresponding to the complex layer 40 of the plating layer, and the area not covered with the protective layer is removed by etching. How to,

ii) A method of protecting the surface of the rear plate 30 other than the region corresponding to the colored layer 40 with a mask, and then forming a plating layer only in the region corresponding to the colored layer 40, etc.

Can be mentioned.

The thickness of the plating layer is preferably 100 nm or more and 3000 nm or less, and more preferably 500 nm or more and 2000 nm or less. When the thickness of the plating layer is 100 nm or more, the reflected light from the plating layer is easily recognized. Further, by setting the thickness of the plating layer to 3000 nm or less, durability against warpage can be improved.

When the colored layer 40 has a plated layer, it may be constituted by a single layer of a plated layer, or may be constituted by a plurality of layers including a plated layer. In the case of a configuration in which the colored layer 40 has another layer on the upper side of the plating layer (the bonding layer 20 side), the layer on the upper side of the plating layer is preferably a layer that is at least transparent to the extent that reflected light from the plating layer is visible. And, for example, it is preferable that it is a transparent protective layer. Specifically, in the process of patterning, a transparent protective layer provided to prevent the plating layer of the colored layer 40 from being removed can be used. The colored layer 40 may have a colorant-containing layer having high light-shielding property or a base layer for improving adhesion, on the lower side of the plating layer (the back plate 30 side). The protective layer provided so as to cover the plating layer may be formed so as to cover at least a part of the surface on the visible side of the plating layer, and does not need to be formed so as to cover the entire surface including the side surface of the plating layer. The base layer provided on the lower side of the plating layer is covered with a plating layer, and the plating layer may be formed to cover at least a part of the visible side of the base layer, and is formed to cover the entire surface including the side surfaces of the base layer. It doesn't have to be.

Examples of the colorant contained in the colorant-containing layer include carbon black such as acetylene black, and black colorant such as iron black. The protective layer and the colorant-containing layer can be formed by a method such as a printing method or a coating method. Specific examples of the printing method include gravure printing, offset printing, screen printing, and transfer printing from a transfer sheet. Printing according to a printing method may be repeatedly performed to obtain a layer having a desired thickness. The ink used in the printing method includes, for example, an ink containing a binder, a solvent, and optional additives. In the case of forming a colored layer-containing layer, an ink containing a colorant is used.

Examples of the binder include chlorinated polyolefin (eg, chlorinated polyethylene, chlorinated polypropylene), polyester resin, urethane resin, acrylic resin, vinyl acetate resin, vinyl chloride-vinyl acetate copolymer, and cellulose resin. The binder resin may be used alone or in combination of two or more. The binder resin may be a thermally polymerizable resin or a photopolymerizable resin.

In the case of forming the colorant-containing layer according to the printing method, it is preferable to use an ink containing 50 to 200 parts by mass of the colorant relative to 100 parts by mass of the binder resin.

When the colored layer 40 is provided on the periphery of the rear plate 30, it is not limited to a form provided on all sides of the periphery, and may be provided only on a part of the periphery according to a desired design or the like. When the colored layer 40 is provided on the periphery of the rear plate 30, the width can be appropriately determined according to the size of the display area, a desired design, etc., for example, in the range of 1 mm to 20 mm. desirable. In addition, although it is preferable that the colored layer 40 is provided in the entire area of the non-display area, it may be formed in a partial area of the non-display area.

(Polarizer)

Examples of the polarizing plate include a stretched film in which a dye having absorption anisotropy is adsorbed, or a film including a film obtained by coating and curing a dye having absorption anisotropy as a polarizer.

As a dye having absorption anisotropy, a dichroic dye can be mentioned, for example. Specifically, as a dichroic dye, iodine or a dichroic organic dye is used. For dichroic organic dyes, 　C.I. A dichroic direct dye composed of a disazo compound such as DIRECT 　 RED 　 39 　, a dichroic direct dye composed of a compound such as tris azo and tetrakis azo are included. As a film to which a dye having absorption anisotropy is applied as a polarizer, a stretched film in which a dye having absorption anisotropy is adsorbed, or a composition containing a dichroic dye having liquid crystal properties, or a dichroic dye and a polymerizable liquid crystal are included. And a film having a layer obtained by coating and curing the composition described above. The film obtained by coating and curing a dye having absorption anisotropy is preferable because it is not limited to the bending direction as compared to a stretched film to which a dye having absorption anisotropy is adsorbed.

(1) Polarizing plate provided with a stretched film as a polarizer

A polarizing plate provided with a stretched film adsorbing a dye having absorption anisotropy as a polarizer will be described. A stretched film in which a dye having absorption anisotropy, which is a polarizer, is adsorbed is usually a step of uniaxially stretching a polyvinyl alcohol-based resin film, and the dichroic dye is adsorbed by dyeing the polyvinyl alcohol-based resin film with a dichroic dye. It is produced through a step of treating, a step of treating a polyvinyl alcohol-based resin film adsorbed with a dichroic dye with an aqueous boric acid solution, and a step of washing with water after treatment with an aqueous boric acid solution. You may use such a polarizer as it is as a polarizing plate, and you may use the thing which laminated|attached a transparent protective film on one side or both sides of it as a polarizing plate. The thickness of the polarizer thus obtained is preferably 2 µm to 40 µm.

Polyvinyl alcohol-based resin is obtained by saponifying a polyvinyl acetate-based resin. As the polyvinyl acetate-based 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 which can be copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

The degree of saponification 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 degree of polymerization of the polyvinyl alcohol-based resin is usually about 1,000 to 10,000, and preferably in the range of 1,500 to 5,000.

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

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

The material of the protective film bonded to one side or both sides of the polarizer is not particularly limited, but, for example, a cyclic polyolefin resin film, an cellulose acetate resin film made of a resin such as triacetyl cellulose, and diacetyl cellulose, Polyethylene terephthalate, polyethylene naphthalate, polyester resin film made of a resin such as polybutylene terephthalate, polycarbonate resin film, (meth)acrylic resin film, polypropylene resin film, and other films known in the art Can be mentioned. From the viewpoint of thinning, 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. 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 used as a polarizer, a composition containing a dichroic dye having liquid crystal properties, or a film obtained by coating and curing a composition containing a dichroic dye and a liquid crystal compound on a substrate, etc. Can be mentioned. 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 sides thereof. As said protective film, the same thing as the polarizing plate provided with the said stretched film as a polarizer is mentioned.

A thin film obtained by coating and curing a dye having absorption anisotropy is preferably thin, but if it is too thin, the strength decreases and workability tends to be inferior. The thickness of the film is usually 20 μm or less, preferably 5 μm or less, and more preferably 0.5 μm or more and 3 μm or less.

As a film obtained by applying the dye having absorption anisotropy, specifically, a film described in Japanese Patent Application Laid-Open No. 2013-37353 or Japanese Patent Application Laid-Open No. 2013-33249 can be mentioned.

The polarizing plate may further include a retardation film. The retardation film may include one or two or more retardation layers. The retardation layer may be a positive A plate such as a λ/4 plate or a λ/2 plate, and a positive C plate. The retardation layer may be formed of a resin film exemplified as a material of the above-described protective film, or may be formed of a layer obtained by curing a polymerizable liquid crystal compound. The retardation film may further contain an alignment film or a base film. When the polarizer and the retardation film are arranged so that the absorption axis of the polarizer and the slow axis of the retardation film form a predetermined angle, the polarizing plate may have an antireflection function, that is, function as a circular polarizing plate.

(Touch sensor panel)

As for the touch sensor panel, as long as it is a sensor capable of detecting a touched position, the detection method is not limited, such as a resistive film method, a capacitive coupling method, an optical sensor method, an ultrasonic method, an electromagnetic inductive coupling method, and a surface acoustic wave method. A touch sensor panel is illustrated. In view of low cost, a resistive film type and a capacitive coupling type touch sensor panel are suitably used.

An example of a resistive film type touch sensor panel is a pair of substrates disposed opposite to each other, an insulating spacer sandwiched between the pair of substrates, a transparent conductive film provided as a resistive film on the entire inner surface of each substrate, and touch It is composed of a position detection circuit. In the image display device provided with the resistive film type touch sensor panel, when the surface of the front plate 10 is touched, the opposite resistive film is short-circuited, and a current flows through the resistive film. The touch position detection circuit detects a change in voltage at this time, and the touched position is detected.

An example of a capacitive coupling type touch sensor panel is constituted by a substrate, a position detection transparent electrode provided on the entire surface of the substrate, and a touch position detection circuit. In the image display device provided with the capacitive coupling type touch sensor panel, when the surface of the front plate 10 is touched, the transparent electrode is grounded through the capacitance of the human body at the touched point. The touch position detection circuit detects the ground of the transparent electrode, and the touched position is detected.

The thickness of the touch sensor panel may be 5 to 500 μm, and is preferably 10 to 100 μm.

[Manufacturing method of optical laminate]

In the manufacturing method of an optical laminate according to an embodiment of the present invention, after the colored layer forming step of forming the colored layer on a part of the outermost layer on the bonding layer side of the rear plate, and the colored layer forming step, the outermost layer It has a lamination process of laminating the said bonding layer to. 9 is a cross-sectional view schematically showing a method of manufacturing an optical laminate according to an embodiment of the present invention. In the manufacturing method of an optical laminate according to one embodiment of the present invention, the step of preparing the rear plate 30 (Fig. 9(a)), forming the colored layer 40 on the surface of the rear plate 30 A colored layer forming process (Fig. 9(b)), and a lamination process for obtaining an optical laminate 100 by laminating the back plate 30 on which the colored layer 40 is formed, the bonding layer 20, and the front plate 10 (Fig. 9(e)).

Before the lamination process (FIG. 9(e)), the process of preparing the front plate 10 (FIG. 9(c)), and the process of providing the bonding layer 20 on the surface of the front plate 10 (FIG. 9 You may have (d)).

When the back plate 30 is a polarizing plate, the back plate with the colored layer 40 obtained in the intermediate step of the manufacturing method (the laminate obtained in Fig. 9(b)) becomes a polarizing plate having a colored layer. The surface of the rear plate 30 on which the colored layer 40 is formed is the surface on the viewing side of the polarizing plate. As described above, the polarizing plate having a colored layer is useful in order to obtain the optical laminate 100 having high durability against warping.

When the back plate 30 is a composite layer, in Fig. 9(a), instead of the step of preparing the back plate 30, the rear surface including the outermost layer on the side of the bonding layer 20 of the back plate 30 It may be a step of preparing a part of the plate 30. In this case, the timing at which the rear plate 30 made of the composite layer is formed is not limited, and may be after the step of Fig. 9(e). The method shown in Fig. 11 described later corresponds to this method. In addition, the expression of the outermost layer on the side of the bonding layer of the rear plate 30 includes either the outermost layer before the rear plate 30 is configured and the outermost layer after the rear plate 30 is configured.

[Use of image display device]

The image display device according to the present invention can be used as mobile devices such as smart phones and tablets, televisions, digital photo frames, electronic signs, measuring devices and instruments, office devices, medical devices, computing devices, and the like. The optical laminate of the present invention has a colored layer and has durability against warping, and thus it is possible to provide a high-quality image display device in which the occurrence of appearance defects is suppressed.

Example

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

(Examples 1 to 3, Comparative Examples 1 and 2)

<Preparation of the composition for forming a colored layer (black)>

[Ink component]

Acetylene black 15% by mass

Polyester 75% by mass

Dimethyl glutamate 2.5% by mass

Succinic acid 2% by mass

Isophorone 5.5% by mass

[Hardener]

Aliphatic polyisocyanate 75% by mass

Ethyl acetate 25% by mass

[menstruum]

Isophorone

[Production method]

To 100 parts by mass of the ink component, 10 parts by mass of a curing agent and 10 parts by mass of a solvent were added and stirred to obtain a composition for forming a colored layer (black).

<Preparation of the composition for forming a colored layer (white)>

[Ink component]

Titanium dioxide 50% by mass

Polyester 39% by mass

Dimethyl glutamate 2.5% by mass

Succinic acid 2% by mass

Isophorone 6.5% by mass

[Hardener]

Aliphatic polyisocyanate 75% by mass

Ethyl acetate 25% by mass

[menstruum]

Isophorone

[Production method]

To 100 parts by mass of the ink component, 10 parts by mass of a curing agent and 10 parts by mass of a solvent were added and stirred to obtain a composition for forming a colored layer (white).

<Example 1>

In the procedure shown in FIG. 11, the optical laminated body of Example 1 was produced. Specifically, a 70 µm-thick window film (substrate film 50 µm, each hard coat layer 10 µm, length 177 mm × width 105 mm) was prepared as the front plate 10 with hard coat layers formed on both sides of the base film. (Fig. 11(c)), as the bonding layer 20, a (meth)acrylic pressure-sensitive adhesive layer (thickness 25 μm, length 177 mm × width 105 mm) was prepared. The base film of the window film is a polyimide resin film, and the hard coat layer is a layer formed of a composition containing a dendrimer compound having a polyfunctional acrylic group at the terminal. Then, corona treatment was performed on the bonding surface of the window film with the adhesive layer, and the bonding surface of the adhesive layer with the window film.

And the window film and the adhesive layer were bonded together, and the window film which has the adhesive layer was obtained (FIG. 11(d)).

Further, a composition containing a dichroic dye and a polymerizable liquid crystal compound was applied to a substrate and cured to obtain a polarizer having a thickness of 2 μm. On the polarizer, a 25 µm-thick triacetylcellulose (TAC) film was bonded to each other through an adhesive layer. A retardation film comprising a layer obtained by peeling off the substrate and curing by polymerizing a liquid crystal compound on the exposed surface (thickness 17 μm, layer configuration: overcoat layer (cured layer of acrylic resin composition, thickness 1 μm)/adhesive layer (thickness 5 µm) / λ/4 plate (thickness 3 µm) / adhesive layer (thickness 5 µm) / positive C plate (thickness 3 µm) consisting of a layer cured with a liquid crystal compound and an alignment film consisting of a layer cured with a liquid crystal compound and an alignment film ) Was attached. Thus prepared polarizing plate 60d (layer structure of "TAC/polarizer/phase difference film", thickness 44 µm, length 177 mm × width 105 mm) was prepared (Fig. 11(a)), and the polarizing plate 60d On the surface of the TAC, using the composition for forming a colored layer (black) prepared above as ink, by screen printing using a 460 mesh screen, printing of a discharge amount having a coating thickness of 3 μm after drying is repeated twice. Then, a black colored layer 40 having a thickness of 6 μm and a width of 5 mm was formed on all sides of the peripheral portion to obtain a polarizing plate having a colored layer (Fig. 11(b)).

Thereafter, the window film having the pressure-sensitive adhesive layer and the polarizing plate having the colored layer were subjected to corona treatment on the surfaces on which the pressure-sensitive adhesive layer and the colored layer were formed, respectively, and then laminated so that these surfaces were inside, and bonded using a roll bonding machine. (Fig. 11(e)). In addition, on the surface of the polarizing plate 60d on the opposite side of the window film side, through the pressure-sensitive adhesive layer 21 (thickness 25 μm), touch on the touch sensor panel 71 (cyclic olefin resin film (thickness 23 μm)). The sensor pattern (those having a thickness of 10 µm) was laminated so that the cyclic olefin resin film became a surface layer to obtain an optical laminate of Example 1 (Fig. 11(f)). In the optical laminated body of Example 1, a laminate made of "polarizing plate 60d/adhesive layer 21/touch sensor panel 71" corresponds to the rear plate 30. The distance d1 from the surface of the colored layer 40 on the side close to the window film to the outermost surface on the side of the window film in the optical laminate was 89 µm. The distance d2 from the surface of the colored layer 40 on the far side from the window film to the outermost surface on the side of the cyclic olefin resin film in the optical laminate was 102 µm. The size of the difference between the two was 13 μm, and the size D of the relative difference was 6.8% (≒100×|(102-89)/(102+89)|).

<Example 2>

When forming the colored layer, by screen printing, printing of a discharge amount having a coating thickness of 6 µm after drying is repeatedly performed twice to form a colored layer 40 having a thickness of 12 µm and a width of 5 mm on all sides of the periphery. Except for one point, an optical laminate was produced by the same method as in Example 1. The distance d1 was 83 μm, the distance d2 was 102 μm, the difference between the two was 19 μm, and the relative size D was 10.3% (≒100×|(102-83)/(102+83)|).

<Example 3>

When forming the colored layer, by screen printing the colored layer forming composition (black) as an ink, printing of the discharge amount having a coating thickness of 3 μm after drying is repeatedly performed twice, and thereafter, on the printed layer, By screen printing the composition for forming a colored layer (white) as an ink, printing a discharge amount having a coating thickness of 5 μm after drying is repeatedly performed three times, and coloring white with a thickness of 21 μm and a width of 5 mm on all sides of the periphery An optical laminate was produced in the same manner as in Example 1 except that the layer 40 was formed. The distance d1 was 74 μm, the distance d2 was 102 μm, the difference between the two was 28 μm, and the relative size D was 15.9% (≒100×|(102-74)/(102+74)|).

<Comparative Example 1>

In the procedure shown in FIG. 12, the optical laminated body of Comparative Example 1 was produced. Specifically, as the front plate 10, a 70 µm-thick window film (substrate film 50 µm, each hard coat layer 10 µm, length 177 mm x 105 mm in width) with hard coat layers formed on both sides of the base film was prepared. (Fig. 12(b)). The base film of the window film is a polyimide resin film, and the hard coat layer is a layer formed of a composition containing a dendrimer compound having a polyfunctional acrylic group at the terminal. Then, on the bonding surface of the window film with the pressure-sensitive adhesive layer, by screen printing using the composition for forming a colored layer (black) prepared above as ink, printing of a discharge amount having a coating thickness of 6 μm after drying was repeatedly performed 2 It performed twice, and formed a black colored layer 41 having a thickness of 12 µm and a width of 5 mm on all sides of the periphery to obtain a window film having a colored layer (Fig. 12(c)).

Further, as the bonding layer 20, a (meth)acrylic pressure-sensitive adhesive layer (thickness 25 µm, length 177 mm × width 105 mm) was prepared, and corona treatment was performed on the bonding surface with the window film. Then, after corona treatment was performed on the surface of the window film on which the colored layer was formed, the pressure-sensitive adhesive layer was bonded to obtain a window film provided with the colored layer and the pressure-sensitive adhesive layer (Fig. 12(d)).

Further, a composition containing a dichroic dye and a polymerizable liquid crystal compound was applied to a substrate and cured to obtain a polarizer having a thickness of 2 μm. On the polarizer, an adhesive layer was released, and a 25 µm-thick triacetylcellulose (TAC) film was adhered. A retardation film comprising a layer obtained by peeling off the substrate and curing by polymerizing a liquid crystal compound on the exposed surface (thickness 17 μm, layer configuration: overcoat layer (cured layer of acrylic resin composition, thickness 1 μm)/adhesive layer (thickness 5 µm) / λ/4 plate (thickness 3 µm) / adhesive layer (thickness 5 µm) / positive C plate (thickness 3 µm) consisting of a layer cured with a liquid crystal compound and an alignment film consisting of a layer cured with a liquid crystal compound and an alignment film ) Was attached. Thus produced polarizing plate 60d (layer structure of "TAC/polarizer/phase difference film", thickness 44 µm, length 177 mm x width 105 mm) was prepared (Fig. 12(a)). After that, corona treatment is performed on the TAC side surface of the polarizing plate 60d, and a polarizing plate is laminated so that the TAC side is inside on the surface on which the colored layer and the pressure-sensitive adhesive layer are formed of the window film on which the colored layer and the pressure-sensitive adhesive layer are installed, They were bonded together using a bonding machine (Fig. 12(e)). In addition, on the surface of the polarizing plate 60d on the opposite side of the window film side, through the pressure-sensitive adhesive layer 21 (thickness 25 μm), touch on the touch sensor panel 71 (cyclic olefin resin film (thickness 23 μm)). The sensor pattern (those having a thickness of 10 µm) was laminated so that the cyclic olefin resin film became a surface layer to obtain an optical laminate of Comparative Example 1 (Fig. 12(f)). In the optical laminated body of Comparative Example 1, a laminate made of "polarizing plate 60d/adhesive layer 21/touch sensor panel 71" corresponds to the rear plate 30. The distance d1 from the surface of the colored layer 41 on the side near the window film to the outermost surface on the window film side in the optical laminate was 70 µm. The distance d2 from the surface of the colored layer 41 on the far side from the window film to the outermost surface on the side of the cyclic olefin resin film in the optical laminate was 115 µm. The size of the difference between the two was 45㎛, and the size of the relative difference was 24.3% (≒100×|(115-70)/(115+70)|).

<Comparative Example 2>

When forming the colored layer, by screen printing the colored layer forming composition (black) as an ink, printing of the discharge amount having a coating thickness of 3 μm after drying is repeatedly performed twice, and thereafter, on the printed layer, By screen printing the composition for forming a colored layer (white) as an ink, printing a discharge amount having a coating thickness of 5 μm after drying is repeatedly performed three times, and coloring white with a thickness of 21 μm and a width of 5 mm on all sides of the periphery An optical laminate was produced in the same manner as in Comparative Example 1 except that the layer 41 was formed. The distance d1 was 70 μm, the distance d2 was 106 μm, the difference between the two was 36 μm, and the relative size D was 20.5% (≒100×|(106-70)/(106+70)|).

[Evaluation test]

For the optical laminates of Examples 1 to 3 and Comparative Examples 1 and 2, an evaluation test was performed to confirm the durability against bending using a bending evaluation equipment (manufactured by Science 　 Town, STS-VRT-500). 10 is a diagram schematically showing a method of this evaluation test. As shown in Fig. 10, two mounting tables 501 and 502 that can be moved individually are arranged so that the gap C is 2.5 mm, and the optical laminate 100 is positioned so that the center of the gap C in the width direction is located. ) Was fixed and placed (Fig. 10(a)). At this time, the optical laminated body 100 was arrange|positioned so that the window film (front plate 10) may become upper. In addition, the two mounting tables 501 and 502 were rotated 90 degrees upward as the centers of the rotation axis of the position P1 and the position P2, so that a bending force was applied to the region of the optical laminate 100 corresponding to the gap C of the mounting table. (Fig. 10(b)). After that, the two mounting tables 501 and 502 were returned to their original positions (Fig. 10(a)). After the above series of operations were completed, the number of times the bending force was applied was counted once. Accumulate the number of times of addition of the bending force, check the occurrence of cracks in the colored layer in the region of the optical laminate 100 corresponding to the gap C of the mounting tables 501 and 502, and the bending force at the time when the cracks occur The addition was stopped, and evaluation was performed according to the following criteria. Table 1 shows the evaluation results. The moving speeds of the mounting tables 501 and 502 and the additional face of the bending force were set to the same conditions in the evaluation test for any optical laminate.

A: No cracking occurred even when the number of times of applying the bending force reached 200,000.

B: Cracks occurred when the number of times the bending force was applied was 150,000 or more and less than 200,000.

C: Cracks occurred when the number of times the bending force was applied was 100,000 or more and less than 150,000.

D: Cracks occurred when the number of times the bending force was applied was 50,000 or more and less than 100,000.

E: Cracks occurred when the number of times the bending force was applied was less than 50,000.

(Examples 4 and 5)

<Preparation of a composition for forming a colorant-containing layer (black)>

[Ink component]

Acetylene black 15% by mass

Polyester 75% by mass

Dimethyl glutamate 2.5% by mass

Succinic acid 2% by mass

Isophorone 5.5% by mass

[Hardener]

Aliphatic polyisocyanate 75% by mass

Ethyl acetate 25% by mass

[menstruum]

Isophorone

[Preparation method]

With respect to 100 parts by mass of the ink component, 10 parts by mass of a curing agent and 10 parts by mass of a solvent were added and stirred to obtain a composition for forming a colorant-containing layer (black).

<Preparation of the composition for forming a protective layer (transparent)>

[Ink component]

Polyester 90% by mass

Dimethyl glutamate 2.5% by mass

Succinic acid 2% by mass

Isophorone 5.5% by mass

[Hardener]

Aliphatic polyisocyanate 75% by mass

Ethyl acetate 25% by mass

[menstruum]

Isophorone

[Preparation method]

To 100 parts by mass of the ink component, 10 parts by mass of a curing agent and 10 parts by mass of a solvent were added and stirred to obtain a composition for forming a protective layer.

<Preparation of a composition for forming a colorant-containing layer (metal silver color)>

[Ink component]

Aluminum powder (metal pigment) 15% by mass

Polyester 75% by mass

Dimethyl glutamate 2.5% by mass

Succinic acid 2% by mass

Isophorone 5.5% by mass

[Hardener]

Aliphatic polyisocyanate 75% by mass

Ethyl acetate 25% by mass

[menstruum]

Isophorone

[Preparation method]

To 100 parts by mass of the ink component, 10 parts by mass of a curing agent and 10 parts by mass of a solvent were added and stirred to obtain a composition for forming a colorant-containing layer (metal silver color).

<Preparation of photosensitive resin composition>

[Suzy]

Acrylate polymer 7% by mass

Methacrylate monomer 81% by mass

[Hardener]

1, 6-hexane diisocyanate 10% by mass

Triphenyl phosphine 2% by mass

[Preparation method]

Each of the above components was mixed and stirred to obtain a photosensitive resin composition.

<Production of adhesive sheet>

On a mass basis, 84 parts of 2-ethylhexyl acrylate, 15 parts of isobornyl acrylate, 1 part of hydroxy propyl acrylate, and 0.02 parts of 1-hydroxycyclohexylphenyl ketone as a polymerization initiator were mixed. The mixture was irradiated with ultraviolet rays to polymerize the monomer.

Thereafter, 0.4 parts of 1-hydroxycyclohexylphenyl ketone, 0.3 parts of lauryl acrylate, 0.05 parts of polyethylene glycol (200) caracrylate, 0.05 parts of (3-glycidyloxypropyl) trimethoxysilane as polymerization initiators Was added to the mixture to prepare a pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition was coated on a polyethylene terephthalate film (release film) whose surface was treated with silicone. The coating thickness was set to 25 µm. Another release film was prepared and laminated on the coating film. The laminate having a layer structure of a release film/adhesive composition coating/release film was irradiated with ultraviolet rays. In the ultraviolet irradiation step, ultraviolet rays of 300 to 400 nm (the luminous intensity becomes maximum at 365 nm) were irradiated to the laminate so that the accumulated light amount became 1500 mJ/cm 2. In this way, an adhesive sheet provided with a (meth)acrylic adhesive layer was produced.

<Example 4>

(Production of a window film having an adhesive layer)

In the procedure shown in FIG. 9, the optical laminated body of Example 1 was produced. Specifically, a 70 µm-thick window film (substrate film 50 µm, each hard coat layer 10 µm, length 177 mm × width 105 mm) was prepared as the front plate 10 with hard coat layers formed on both sides of the base film. (Fig. 9(c)), as the bonding layer 20, the (meth)acrylic pressure-sensitive adhesive layer (thickness 25 μm, length 177 mm × width 105 mm) of the pressure-sensitive adhesive sheet produced above was used. The base film of the window film is a polyimide resin film, and the hard coat layer is a layer formed of a composition containing a dendrimer compound having a polyfunctional acrylic group at the terminal. Then, corona treatment was performed on the bonding surface of the window film with the adhesive layer and the bonding surface of the window film of the adhesive layer. And the window film and the adhesive layer were bonded together, and the window film which has the adhesive layer was obtained (FIG. 9(d)).

(Manufacture of polarizing plate)

After forming the photo-alignment film on the substrate, a composition containing a dichroic dye and a polymerizable liquid crystal compound was applied to the substrate, aligned and cured to obtain a polarizer having a thickness of 2 μm. On the polarizer, a 25 µm-thick triacetylcellulose (TAC) film was bonded to each other through an adhesive layer. A retardation film (17 µm in thickness, layer configuration: overcoat layer (cured layer of acrylic resin composition, 1 µm in thickness)/adhesive layer (thickness) comprising a layer obtained by peeling the base material and curing the liquid crystal compound on the exposed surface 5 μm)/λ/4 plate (thickness 3 μm)/adhesive layer (thickness 5 μm)/positive C plate (thickness 3 μm) consisting of a layer cured with a liquid crystal compound and an alignment film consisting of an alignment film and a layer cured with a liquid crystal compound ) Was attached. The thus-prepared polarizing plate (layer structure of "TAC/polarizer/phase difference film", thickness 44 µm, length 177 mm × width 105 mm) was prepared as the rear plate 30 (Fig. 9(a)).

(Formation of colored layer)

On the surface of the TAC of the polarizing plate, using the composition for forming a colorant-containing layer (black) prepared above as ink, by screen printing using a 460 mesh screen, printing of a discharge amount having a coating thickness of 3 μm after drying was performed, A black print layer having a thickness of 3 µm and a width of 5 mm was formed in the non-display area.

Using an electron beam evaporation device (product name: UNIVAC2050, manufactured by UNIVAC) on the TAC surface of the polarizing plate on which the black printed layer is formed, an 80Å-thick evaporation layer is formed using TiO ₂ as a evaporation source, and In is deposited on it. A deposition layer having a thickness of 500 Å was formed as, and a deposition layer having a thickness of 150 Å was formed using TiO ₂ as a deposition source, and a deposition layer having a thickness of 150 Å was formed thereon using Al ₂ O ₃ as a deposition source. In this way, a gold deposition layer (plating layer, thickness <1 µm) consisting of four layers was formed over all areas including the non-display area and the display area. Thereafter, in the non-display area of the surface of the gold deposition layer, the coating thickness after drying was 5 μm by screen printing using a 460 mesh screen using the composition for forming a protective layer (transparent) prepared above as ink. A protective layer was formed by printing the discharged amount, and the gold deposited layer in the area (display area) where the protective layer was not formed was removed by etching. In this way, in the non-display area, the layer structure of "black evaporation layer (thickness 3 μm)/gold color evaporation layer (thickness <1 μm)/protection layer (thickness 5 μm)” (overall thickness of 8 μm and less than 9 μm) ) To form the colored layer 40 (Fig. 9(b)).

(Production of optical laminate)

After that, corona treatment is performed on the side of the pressure-sensitive adhesive layer of the window film having the pressure-sensitive adhesive layer and the side on which the colored layer 40 of the polarizing plate is formed, and the window film having the pressure-sensitive adhesive layer so that the corona-treated side is inside The hyperpolarizing plate was laminated and bonded together using a roll bonding machine, and the optical laminated body of Example 4 was obtained (FIG. 9(e)).

<Example 5>

The optical laminate of Example 2 was obtained in the same manner as in Example 3 except that the colored layer 40 was formed by the thermal transfer method as follows (Fig. 9(e)).

The photosensitive resin composition prepared above was applied to the surface of the substrate film (100 μm thick PET film) for thermal transfer so that the thickness after curing became 8 μm, and an ultraviolet irradiation device (product name: UV　Pattern　Machine, JM　UV　Tech) ) By irradiation with ultraviolet rays to cure the coating layer to form a resin layer.

On the entire surface of the resin layer on the surface of the base film, an e-beam evaporation device (product name: UNIVAC2050, manufactured by UNIVAC) was used to form an 80Å-thick evaporation layer using TiO ₂ as the evaporation source, and on it In as the evaporation source. A deposition layer having a thickness of 500 Å was formed, a deposition layer having a thickness of 150 Å was formed on the TiO ₂ as a deposition source, and a deposition layer having a thickness of 150 Å was formed thereon using Al ₂ O ₃ as a deposition source. In this way, a gold evaporation layer (plating layer, thickness <1 µm) consisting of four layers was formed. Thereafter, in the area corresponding to the non-display area on the surface of the gold-colored evaporation layer, the coating thickness after drying by screen printing using a 460 mesh screen using the above prepared colorant-containing layer-forming composition (black) as ink A black print layer (thickness of 3 µm) was formed by printing at a discharge amount of 3 mu m, and the gold deposited layer in the region where the black print layer was not formed (a region corresponding to the display region) was removed by etching. In this way, a colored layer precursor having a layered configuration of “gold vapor deposition layer (thickness <1 μm)/black print layer (thickness 3 μm)” was formed on the base film for thermal transfer.

The coating thickness after drying was 3 μm by screen printing using a 460 mesh screen using the protective layer forming composition (transparent) prepared above as ink on the entire surface of the base film on which the colored layer precursor was formed. The resulting discharge amount was printed to form a semi-dry protective layer (functions as an adhesive layer during thermal transfer). Then, using a thermal transfer device (product name: 2D transfer equipment, manufactured by Iroomo), the resin layer containing the colored layer precursor was thermally transferred to the TAC surface of the polarizing plate, and the “gold deposited layer (thickness <1 μm)/ A colored layer precursor having a layered configuration of a black printing layer (thickness 3 μm)” was provided on the TAC surface of the polarizing plate, and this was used as the colored layer 40.

[Evaluation test]

For the optical laminates of Examples 4 and 5, an evaluation test was performed to confirm the durability against warpage using a flexure evaluation facility (Science® Town, STS-VRT-500). 10 is a diagram schematically showing a method of this evaluation test. As shown in FIG. 10, two mounting tables 501 and 502 that can be moved individually are arranged so that the gap C is 5.0 mm (2.5 R), and the center of the width direction is located at the center of the gap C. The sieve 100 was fixed and placed (Fig. 10(a)). At this time, the optical laminated body 100 was arrange|positioned so that the window film (front plate 10) may become upper. In addition, the two mounting tables 501 and 502 were rotated 90 degrees upward as the centers of the rotation axis of the position P1 and the position P2, so that a bending force was applied to the region of the optical laminate 100 corresponding to the gap C of the mounting table. (Fig. 10(b)). After that, the two mounting tables 501 and 502 were returned to their original positions (Fig. 10(a)). The above series of operations were completed, and the number of times the bending force was applied was counted once. By accumulating the number of times the bending force was applied, it was confirmed whether or not cracks of the colored layer occurred in the region of the optical laminate 100 corresponding to the gap C of the mounting tables 501 and 502, and warped at the time when the cracks occurred. The addition of force was stopped, and evaluation was performed based on the following criteria. Table 1 shows the evaluation results. The moving speeds of the mounting tables 501 and 502 and the additional face of the bending force were set to the same conditions in the evaluation test for any optical laminate.

A: No cracking occurred even when the number of times of applying the bending force reached 200,000.

B: Cracks occurred when the number of times the bending force was applied was 150,000 or more and less than 200,000.

C: Cracks occurred when the number of times the bending force was applied was 100,000 or more and less than 150,000.

D: Cracks occurred when the number of times the bending force was applied was 50,000 or more and less than 100,000.

E: Cracks occurred when the number of times the bending force was applied was less than 50,000.

10 front panel,
20 laminated layers,
30 back plate,
40, 41 colored layers,
60a, 60b, 60c, 60d polarizer,
70 touch sensor panel,
81 liquid crystal display unit,
82 organic EL display unit,
90 backlight units,
100, 101, 102, 103, 104 optical laminate,
200 indication laminate,
300 image display,
301, 302 liquid crystal display,
303, 304 organic EL display,
305, 306 flexible display.
501, 502 wit,
A display area,
B Non-display area,
C break.

Claims (18)

As an optical laminate comprising a front plate, a bonding layer, and a back plate in this order,
The optical laminated body further comprising a colored layer provided on a part of the surface of the rear plate on the bonding layer side. The method of claim 1,
The optical layered product, wherein the colored layer has a thickness of 3 μm or more. The method according to claim 1 or 2,
The optical laminated body, wherein the front plate is a resin film. The method according to any one of claims 1 to 3,
The optical laminated body, wherein the back plate has a polarizing plate. An image display device comprising the optical laminate according to any one of claims 1 to 4, wherein the front plate is disposed on the entire surface. A polarizing plate, and
A polarizing plate having a colored layer comprising a colored layer provided on a part of the surface on the viewing side of the polarizing plate. As a manufacturing method for manufacturing the optical laminated body according to any one of claims 1 to 4,
A colored layer forming step of forming the colored layer on a part of the outermost layer on the side of the bonding layer of the back plate, and
A manufacturing method having a lamination step of laminating the bonding layer on the outermost layer after the colored layer forming step. As an optical laminate comprising a front plate, a bonding layer, and a back plate in this order,
Further comprising a colored layer provided on a part of the surface of the back plate on the bonding layer side,
The colored layer comprises a plating layer, the optical laminate. The method of claim 8,
The colored layer further has a protective layer covering the plating layer. The method according to claim 8 or 9,
The colored layer further has a base layer covered with the plating layer. The method of claim 10,
The said base layer is an optical laminated body containing a black pigment. The method according to any one of claims 8 to 11,
The said colored layer is an optical laminated body whose thickness is 1 micrometer or more and 30 micrometers or less. The method according to any one of claims 8 to 12,
The optical laminate is divided into a display area and a non-display area in a plane direction orthogonal to the stacking direction,
The colored layer is provided in the non-display area,
The non-display area has an optical density of 3 or more. The method according to any one of claims 8 to 13,
The optical laminated body, wherein the front plate is a resin film. The method according to any one of claims 8 to 14,
The optical laminated body, wherein the back plate has a polarizing plate. An image display device comprising the optical laminate according to any one of claims 8 to 15, wherein the front plate is disposed on the entire surface. A polarizing plate, and
And a colored layer provided on a part of the surface of the polarizing plate on the viewing side,
The colored layer has a plating layer, and a polarizing plate having a colored layer. As a method for producing the optical laminate according to any one of claims 8 to 15,
A manufacturing method having a colored layer forming step of forming the colored layer on a part of the outermost layer on the side of the bonding layer of the back plate, and a lamination step of laminating the bonding layer on the outermost layer after the colored layer forming step .

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