CN112041914A

CN112041914A - Optical laminate and method for producing same

Info

Publication number: CN112041914A
Application number: CN201980027034.0A
Authority: CN
Inventors: 朴一雨; 姜大山
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 2018-04-24
Filing date: 2019-04-05
Publication date: 2020-12-04
Also published as: TW201945772A; KR20210005063A; JP2019191560A

Abstract

The invention aims to provide an optical laminate which is provided with a colored layer and has suppressed bubbles. An optical laminate comprising a front plate (10), a bonding layer (20), and a back plate (30) in this order in the lamination direction, and further comprising a colored layer (40) provided on a 1 st surface of the back plate (30) on the bonding layer (20) side or a part of a 2 nd surface on the opposite side of the 1 st surface, wherein the colored layer (40) has a thickness of 13 [ mu ] m or less and is disposed so that the front plate (10) is positioned in front of an image display device.

Description

Optical laminate and method for producing same

Technical Field

The present invention relates to an optical laminate and a method for producing the same, and also relates to an image display device and a polarizing plate with a colored layer.

Background

As various image display devices such as liquid crystal display devices and organic electroluminescence display devices, there is known a structure in which a front panel is provided on the visible side of a display panel for the purpose of protecting the display panel. When the display panel is a touch panel, the front panel may function as a touch surface.

Jp 2014-238533 a (patent document 1) describes that a front panel is provided on a visible side of a display panel of an image display device, and a printed layer is provided as a colored layer on a peripheral portion of a surface of the front panel on the display panel side. The colored layer also functions as a shielding layer forming a non-display region of the image display device.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2014-238533.

Disclosure of Invention

The present inventors have found that when a layer having a colored layer is laminated with another layer to form an optical laminate, bubbles may be generated.

The invention aims to provide an optical laminate which is provided with a colored layer and inhibits air bubbles from mixing, an image display device with the optical laminate, a polarizing plate with the colored layer used for the optical laminate, and a manufacturing method of the optical laminate.

The invention provides an optical laminate, an image display device, a polarizing plate with a colored layer, and a method for manufacturing the optical laminate, which are described below.

[ 1] an optical laminate comprising a front plate, a bonding layer, and a back plate in this order in the lamination direction, and further comprising a colored layer provided on a 1 st surface of the back plate on the bonding layer side or a part of a 2 nd surface on the opposite side of the 1 st surface,

the thickness of the colored layer is 13 μm or less,

the front panel is disposed in front of the image display device.

The optical laminate according to [ 1], further comprising a shielding layer not in contact with the colored layer,

the shielding layer is arranged at the following positions: and a position which is farther from the front panel than the colored layer in the stacking direction and at least partially overlaps the colored layer in a plane direction orthogonal to the stacking direction.

The optical laminate according to [ 3] or [ 2], wherein the thickness of the blocking layer is 1 μm to 13 μm.

[ 4 ] the optical laminate according to [ 2] or [ 3], wherein the blocking layer contains a black pigment.

[ 5 ] the optical laminate according to any one of [ 1] to [ 4 ], wherein the optical laminate is divided into a display region and a non-display region in a plane direction orthogonal to the lamination direction,

the colored layer is provided in the non-display region,

the optical density of the non-display region is 3 or more.

The optical laminate according to any one of [ 1] to [ 5 ], wherein the front sheet is a resin film.

An optical laminate according to any one of [ 1] to [ 6 ], wherein the back plate has a polarizing plate.

An image display device comprising the optical laminate according to any one of [ 1] to [ 7 ], wherein the front panel is disposed on a front surface.

[ 9 ] A polarizing plate with a colored layer, comprising:

a polarizing plate, and

a colored layer provided on a part of a surface of the polarizing plate on the visible side;

the colored layer has a thickness of 13 μm or less.

[ 10 ] the polarizing plate with a colored layer according to [ 9 ], wherein a shielding layer is further provided on a surface of the polarizing plate opposite to the surface on the visible side, and the shielding layer is provided on the colored layer with the polarizing plate interposed therebetween.

[ 11 ] A method for producing the optical laminate according to [ 1], comprising a lamination step of laminating the back plate, the adhesive layer, and the front plate to obtain the optical laminate,

the method further includes a coloring layer forming step of forming the coloring layer on the 1 st surface or a part of the 2 nd surface of the rear plate before the laminating step.

The method for producing the optical laminate according to [ 2], comprising:

a laminating step of laminating the back plate, the adhesive layer, and the front plate to obtain the optical laminate, and

a coloring layer forming step of forming the coloring layer on a part of the 1 st surface of the rear plate before the laminating step;

the method further comprises a shielding layer forming step of forming the shielding layer on the 2 nd surface of the rear panel.

According to the present invention, it is possible to provide an optical laminate which includes a colored layer and in which generation of bubbles generated during lamination is suppressed, an image display device including the optical laminate, a polarizing plate with a colored layer used for the optical laminate, and a method for manufacturing the optical laminate.

Drawings

Fig. 1 is a schematic cross-sectional view of an optical laminate according to an embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view of a modification of the optical laminate shown in fig. 1.

Fig. 3 is a schematic cross-sectional view of an image display device according to an embodiment of the present invention.

Fig. 4 is a plan view of the optical layered body viewed from the front panel side.

Fig. 5 is a diagram showing an example of a curved form in the case where the image display device is a flexible display.

Fig. 6 is a schematic cross-sectional view of an image display device according to embodiment 1 of the present invention.

Fig. 7 is a schematic cross-sectional view of an image display device according to embodiment 2 of the present invention.

Fig. 8 is a schematic cross-sectional view of an image display device according to embodiment 3 of the present invention.

Fig. 9 is a schematic cross-sectional view of an image display device according to embodiment 4 of the present invention.

Fig. 10 is a schematic cross-sectional view of an image display device according to embodiment 5 of the present invention.

Fig. 11 is a schematic cross-sectional view of an image display device according to embodiment 6 of the present invention.

Fig. 12 is a sectional view schematically showing an example of the method for producing an optical laminate according to the present invention.

Fig. 13 is a cross-sectional view schematically showing another example of the method for producing an optical laminate according to the present invention.

Detailed Description

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

[ optical layered body ]

Fig. 1 is a schematic cross-sectional view of an optical laminate according to an embodiment of the present invention. The optical laminate 100 of the present embodiment includes a front plate 10, a bonding layer (1 st bonding layer) 20, and a back plate 30 in this order from the visible side. The optical laminate 100 includes a colored layer 40, and the colored layer 40 is provided on a part of the surface (hereinafter also referred to as "1 st surface") of the back surface plate 30 on the 1 st adhesive layer 20 side. Colored layer 40 may be provided on a part of the surface of back surface plate 30 opposite to surface 1 (hereinafter also referred to as "surface 2"). The optical laminate 100 may further include an optical sheet not shown in fig. 1. Examples of the optical sheet include a front optical sheet stacked at a position between the back sheet 30 and the front sheet 10, and a rear optical sheet stacked at a position opposite to the front sheet 10 with respect to the back sheet 30. The optical laminate 100 can be divided into a display region a and a non-display region B in a plane direction perpendicular to the lamination direction, and in this case, the colored layer 40 is preferably provided in the non-display region B.

Fig. 2 is a schematic cross-sectional view of an optical laminate 100' according to a modification of the optical laminate 100 shown in fig. 1. Optical laminate 100' includes colored layer 40 on the 1 st surface of back plate 30 and shielding layer 50 on the 2 nd surface. In this specification, the shielding layer 50 means that it is provided so as not to contact with the colored layer 40 to be distinguished from the colored layer 40. The shielding layer 50 is provided at the following positions: a position which is farther from the front panel 10 than the colored layer 40 in the stacking direction and at least partially overlaps the colored layer 40 in a plane direction orthogonal to the stacking direction. The formation surface of the shielding layer 50 is not limited to the 2 nd surface of the back surface plate 30, and may be provided on any surface of the rear optical plate, for example.

Hereinafter, a case where the optical layered body is divided into a display region a and a non-display region B, and the non-display region B includes the colored layer 40 or includes the colored layer 40 and the shielding layer 50 will be described as an example.

[ image display apparatus ]

Fig. 3 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 the front panel 10 disposed on the front surface, a display laminate 200 including a display unit, and a 2 nd adhesive layer 21 interposed between the optical laminate 100 and the display laminate 200.

Fig. 4 is a plan view of the image display device 300 viewed from the front panel 10 side. The optical density of the non-display region B is preferably 3 or more, and more preferably 3.2 or more. By setting the optical density of the non-display region B to the above numerical range, elements such as wiring disposed in the non-display region B are sufficiently shielded, and the visibility of the image in the display region a is improved. The colored layer 40 contributes to an increase in optical density of the non-display region B. In addition, since the shape and color of the colored layer 40 are visible through the adhesive layer 20 and the front panel 10, the colored layer 40 also contributes to the design of the image display device 300. As long as the colored layer 40 is provided in the non-display region B, the arrangement position in the plane direction is not limited. As shown in the image display device 300 shown in fig. 3 and 4, by disposing the colored layer 40 in the peripheral portion, light leakage can be suppressed, and design can be improved as seen in a frame.

The colored layer 40 has a thickness d3 (shown in fig. 1) of 13 μm or less, preferably 10 μm or less, and more preferably 8 μm or less. When the thickness of the colored layer 40 is within the above numerical range, bubbles generated at the interface can be suppressed. The thickness of the colored layer 40 is preferably 1 μm or more, and more preferably 2 μm or more. By setting the thickness of the colored layer 40 to 1 μm or more, the colored layer 40 is easily visible, contributing to improvement in design, and also contributing to improvement in optical density of the non-display region B.

Although fig. 1 to 3 illustrate the case where the colored layer 40 has a uniform thickness and a rectangular cross-sectional shape, the colored layer 40 may have a non-uniform thickness, and may have a cross-sectional shape having a tapered portion that becomes thinner toward the inside. By having the tapered portion, the entry of air that is likely to occur during lamination can be suppressed. 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.

The shielding layer 50 may be provided at a position at least partially overlapping the colored layer 40 in a plane direction orthogonal to the lamination direction, and is preferably provided in the non-display region B. That is, the shielding layer 50 is preferably provided at a corresponding position of the colored layer 40. The blocking layer 50 disposed in the non-display area B contributes to an increase in optical density of the non-display area B. Therefore, when the optical density of the non-display region B is only the colored layer 40 and does not reach a desired value, the shielding layer 50 is preferably provided. Further, by providing the shielding layer 50 contributing to the improvement of the optical density of the non-display region B separately from the colored layer 40, the function of improving the optical density to be borne by the colored layer 40 is reduced, the adjustment of the thickness of the colored layer 40 is facilitated, and the generation of bubbles at the interface of the colored layer 40 can be suppressed. The thickness of the shielding layer 50 is preferably 1 μm to 13 μm, and more preferably 2 μm to 10 μm.

The total thickness of the colored layer 40 and the shielding layer 50 is preferably 20 μm or less, more preferably 15 μm or less, and still more preferably 12 μm or less. When the amount is within the above range, the step on the surface of the optical layered body can be prevented from being conspicuous.

In fig. 2 and 3, the case where the thickness of the shielding layer 50 is uniform and the sectional shape is rectangular is illustrated, but the thickness of the shielding layer 50 may be non-uniform, and for example, the sectional shape may be a tapered shape in which the thickness becomes thinner toward the inside. By having the tapered portion, it is possible to suppress the entry of air that is likely to be generated during lamination. When the thickness of the mask layer 50 is not uniform, the numerical range described above as the thickness of the mask layer 50 is the maximum thickness of the mask layer 50.

The shape and size of the optical layered body 100 in the plane direction correspond to those of the image display device 300 using the same. The shape of the image display device 300 in the plane direction is preferably a square shape, and more preferably a square shape having long sides and short sides. The 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, 50mm to 300mm, preferably 100mm to 280 mm. The length of the short side is, for example, 30mm to 250mm, preferably 60mm to 220 mm. When the optical layered body 100 has a square shape, at least one of the R process, the notch process, and the hole forming process may be performed.

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

The image display device 300 may be configured as a flexible display panel. Fig. 5 shows an example of a curved form in the case where the image display device is a flexible display panel. Fig. 5(a) shows a flexible display 305 which is configured to be foldable with a visible-side surface as an inner side, and fig. 5(b) shows a flexible display 306 which can be rolled.

When the image display device 300 is a flexible display, a force of repeatedly applying bending to the color layer 40 or a force of continuously applying bending may cause cracks or discoloration. In the image display device 300, cracks and discoloration of the colored layer 40 are not preferable because they are easily visible. In addition, regardless of whether the image display device 300 is a flexible display, when the optical laminate 100 alone has flexibility, a bending force may be applied to the optical laminate 100 when it is transported, and the bending force may cause cracking or discoloration of the color layer 40.

In the optical laminate and the image display device of the present invention, by providing the position of the colored layer 40 on the 1 st surface or the 2 nd surface of the back plate 30, the occurrence of cracks or discoloration of the colored layer 40 can be suppressed even when a bending force is repeatedly or continuously applied. The optical laminate and the image display device of the present invention can prevent the occurrence of cracks and discoloration of the colored layer 40 against a force of bending the front panel 10 inward or a force of bending the front panel 10 outward.

The position of stacking the colored layers 40 can be closer to the center in the stacking direction of the optical layered body 100 than in the case where the colored layers 40 are disposed on the front surface of the front plate 10. That is, the optical layered body 100 may be disposed behind the front surface of the front panel 10. Therefore, it is considered that the stress generated in the colored layer 40 due to the bending is reduced, and the above-described effect is obtained.

From such a viewpoint, when the distance from the surface of the colored layer 40 on the side closer to the front panel 10 to the outermost surface of the optical layered body 100, 100' on the side closer to the front panel 10 is d1 (as shown in fig. 1 and 2), the distance d1 is preferably 50 μm or more, and more preferably 70 μm or more, from the viewpoint of suppressing the occurrence of cracks in bending and the step absorption. When the distance from the surface of the colored layer 40 on the side away from the front panel 10 to the outermost surface (except when the colored layer 40 or the shielding layer 50 is provided on the outermost surface) of the optical layered body 100, 100' on the side opposite to the side where the front panel 10 is arranged is d2 (as shown in fig. 1 and 2), "d 1-d 2" may have an absolute value of 0 μm to 50 μm, for example, 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 still more preferably 15% or less. The lower limit is not particularly limited, and may be 0%. The relative size D (%) of the above difference is calculated by the following formula:

D＝100×|(d1－d2)/(d1+d2)|。

the image display device 300 may be configured as a touch panel type image display device. The touch panel type image display device includes a touch sensor panel, and the front panel 10 included in the optical laminate 100' constitutes a touch surface.

Hereinafter, specific embodiments (embodiments 1 to 6) of the image display device of the present invention are shown, and each constituent element will be described in detail.

< embodiment 1 >

Fig. 6 is a schematic cross-sectional view of an image display device according to embodiment 1 of the present invention. The image display device of the present embodiment is a touch panel liquid crystal display device. The liquid crystal display device 301 includes, in order from the visible side, a front panel 10, a 1 st adhesive layer 20, a polarizing plate 60a, a 2 nd adhesive layer 21, a touch sensor panel 70, a liquid crystal display element unit 81, a polarizing plate 60b, and a backlight unit 90. The colored layer 40 is provided on a part of the surface (the 1 st surface) of the polarizing plate 60a on the 1 st laminating layer 20 side. The shielding layer 50 is preferably provided on a part of the surface (the 2 nd surface) of the polarizing plate 60a on the 2 nd adhesive layer 21 side and on the colored layer 40 with the polarizing plate 60a interposed therebetween. In the liquid crystal display device 301, the display region a and the non-display region B may be divided in the plane direction, and in this case, the colored layer 40 and the shielding layer 50 are preferably provided in the non-display region B.

In the liquid crystal display device 301, a laminate including the front panel 10, the 1 st adhesive layer 20, and the polarizing plate 60a and including the colored layer 40 and the shielding layer 50 is configured as an optical laminate 101, and the liquid crystal display device 301 is configured using the optical laminate 101. In the present embodiment, the polarizing plate 60a also functions as the back panel 30 of the optical laminate 101.

< embodiment 2 >

Fig. 7 is a schematic cross-sectional view of an image display device according to embodiment 2 of the present invention. The image display device of the present embodiment is a touch panel liquid crystal display device. The liquid crystal display device 305 differs from the liquid crystal display device 301 shown in fig. 6 only in that the colored layer 40 is provided on a part of the surface (2 nd surface) of the polarizing plate 60a on the 2 nd adhesive layer 21 side and the shielding layer 50 is not provided. In the liquid crystal display device 305 of the present embodiment, a laminate including the front panel 10, the 1 st adhesive layer 20, and the polarizing plate 60a and including the colored layer 40 is configured as an optical laminate 105, and the liquid crystal display device 305 is configured using the optical laminate 105. In the present embodiment, the polarizing plate 60a also functions as the back panel 30 of the optical laminate 105.

< embodiment 3 >

Fig. 8 is a schematic cross-sectional view of an image display device according to embodiment 3 of the present invention. The image display device of the present embodiment is a touch panel liquid crystal display device. The liquid crystal display device 306 differs from the liquid crystal display device 301 shown in fig. 6 only in that the colored layer 40 is provided on a part of the visible surface (surface No. 1) of the touch sensor panel 70 and the shielding layer 50 is not provided. In the liquid crystal display device 306 of the present embodiment, a laminate including the front panel 10, the 1 st adhesive layer 20, the polarizing plate 60a, the 2 nd adhesive layer 21, and the touch sensor panel 70 and including the colored layer 40 is formed as the optical laminate 106, and the liquid crystal display device 306 is formed using the optical laminate 106. In the present embodiment, the touch sensor panel 70 also functions as the back surface plate 30 of the optical layered body 106.

< embodiment 4 >

Fig. 9 is a schematic cross-sectional view of an image display device according to embodiment 4 of the present invention. The image display device of the present embodiment is a touch panel liquid crystal display device. The liquid crystal display device 302 differs from the liquid crystal display device 301 shown in fig. 6 only in that the lamination position of the polarizing plate 60a and the touch sensor panel 70 is changed, the colored layer 40 is provided on the surface (1 st surface) on the 1 st adhesive layer 20 side of the touch sensor panel 70, and the shielding layer 50 is provided on the surface (2 nd surface) on the 2 nd adhesive layer 21 side of the touch panel sensor 71.

In the liquid crystal display device 302, a laminate including the front panel 10, the 1 st adhesive layer 20, and the touch sensor panel 70 and including the colored layer 40 and the shielding layer 50 is configured as an optical laminate 102, and the liquid crystal display device 302 is configured using the optical laminate 102. In the present embodiment, the touch sensor panel 70 also functions as the back surface plate 30 of the optical layered body 102.

< embodiment 5 >

Fig. 10 is a schematic cross-sectional view of an image display device according to embodiment 5 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 front panel 10, a 1 st adhesive layer 20, a polarizing plate 60c, a 2 nd adhesive layer 21, a touch sensor panel 70, and an organic EL unit 82 in this order from the visible side. The organic EL display device 303 includes a colored layer 40 provided on a part of the surface (the 1 st surface) of the polarizing plate 60c on the 1 st adhesive layer 20 side. The organic EL display device 303 may have the shielding layer 50, and the shielding layer is preferably provided on a part of the surface (2 nd surface) of the polarizing plate 60c on the 2 nd adhesive layer 21 side and on the coloring layer 40 with the polarizing plate 60c interposed therebetween. The organic EL display device 303 may be divided into a display region a and a non-display region B in the plane direction, and in this case, the colored layer 40 and the shielding layer 50 are provided in the non-display region B.

In the organic EL display device 303, a laminate including the front panel 10, the 1 st adhesive layer 20, and the polarizing plate 60c and including the colored layer 40 and the shielding layer 50 is configured as an optical laminate 103, and the organic EL display device 303 is configured by using the optical laminate 103. In the present embodiment, the polarizing plate 60c also functions as the back panel 30 of the optical layered body 103.

< embodiment 6 >

Fig. 11 is a schematic cross-sectional view of an image display device according to embodiment 6 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. 10 only in that the lamination position of the polarizing plate 60c and the touch sensor panel 70 is changed, the coloring layer 40 is provided on the surface (1 st surface) of the touch sensor panel 70 on the 1 st adhesive layer 20 side, and the shielding layer 50 is provided on the surface (2 nd surface) of the touch sensor panel 70 on the 2 nd adhesive layer 21 side.

In the organic EL display device 304, a laminate including the front panel 10, the 1 st adhesive layer 20, and the touch sensor panel 70 and including the colored layer 40 and the shielding layer 50 is configured as an optical laminate 104, and the organic EL display device 304 is configured using the optical laminate 104.

In the present embodiment, the touch sensor panel 70 also functions as the back surface plate 30 of the optical layered body 104.

(display unit)

Examples of the display unit included in the image display device 300 include display units including display elements such as liquid crystal display elements, organic EL display elements, inorganic EL display elements, plasma display elements, and field emission display elements.

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

(front panel)

The material and thickness of the front panel 10 are not limited as long as the front panel is a plate-like body that can transmit light, and a single layer or a plurality of layers may be used. The front panel 10 may constitute the outermost surface of the image display device.

As the glass plate, strengthened glass for display is preferably used. The thickness of the glass plate is, for example, 50 to 1000. mu.m. By using the glass plate, the front panel 10 having excellent mechanical strength and surface hardness can be constituted.

The resin film is not limited as long as it is a resin film that can transmit light.

Examples of the film include films formed of polymers such as cellulose triacetate, cellulose acetate butyrate, ethylene-vinyl acetate copolymer, cellulose propionate, cellulose butyrate, cellulose acetate propionate, polyester, polystyrene, polyamide, polyetherimide, polyacrylic acid, polyimide, polyethersulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polyethersulfone, polymethyl methacrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, and polyamideimide. These polymers may be used alone or in combination of 2 or more. When the image display device 300 is a flexible display, a resin film made of a polymer such as polyimide, polyamide, or polyamideimide, which has excellent flexibility, high strength, and high transparency, is preferably used.

The resin film may be a film having a hard coat layer provided on at least one surface of the base film to further increase the hardness. The hard coat layer may be formed on one surface of the base film or on both surfaces. When the image display device 300 is a touch panel type image display device, the surface of the front panel 10 is a touch surface, and a resin film having a hard coat layer is preferably used. By providing the hard coat layer, a resin film having improved hardness and scratch resistance can be formed. The hard coat layer is a cured layer of, for example, an ultraviolet curable resin. Examples of the ultraviolet curable resin include acrylic resins, silicone resins, polyester resins, polyurethane resins, amide resins, and epoxy resins. The hard coating may contain additives for the purpose of improving strength. The additive is not limited, and examples thereof include inorganic fine particles, organic fine particles, and a mixture thereof. The thickness of the resin film is, for example, 30 to 2000. mu.m.

The front panel 10 may have not only a function of protecting the front of the image display device 300 but also a function as a touch sensor, a blue blocking function, a viewing angle adjusting function, and the like.

(layer 1)

The 1 st adhesive layer 20 is a layer interposed between the front panel 10 and the back panel 30, and is an adhesive layer or an adhesive layer. When the 1 st adhesive layer 20 is provided at a position in contact with the colored layer 40 (for example, embodiment 1 and 4 to 6), an adhesive layer is preferable in terms of being able to favorably absorb the step of the colored layer 40.

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

As the (meth) acrylic resin (base polymer) used in the adhesive composition, for example, a polymer or copolymer in which 1 or 2 or more kinds of (meth) acrylic esters such as butyl (meth) acrylate, ethyl (meth) acrylate, isooctyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate are used as monomers is preferably used. It is preferred to copolymerize polar monomers to the base polymer. Examples of the polar monomer include monomers having a carboxyl group, a hydroxyl group, an amide group, an amino group, an epoxy group, and the like, such as (meth) acrylic acid, 2-hydroxypropyl (meth) acrylate, hydroxyethyl (meth) acrylate, (meth) acrylamide, N-dimethylaminoethyl (meth) acrylate, and glycidyl (meth) acrylate.

The adhesive composition may contain only the above-mentioned base polymer, but usually also contains a crosslinking agent. Examples of the crosslinking agent include metal ions having a valence of 2 or more and a metal carboxylate salt formed between the crosslinking agent and a carboxyl group; polyamine compounds and substances which form amide bonds with carboxyl groups; a polyepoxy compound, a polyhydric alcohol, and a substance forming an ester bond with a carboxyl group; a polyisocyanate compound and a substance forming an amide bond with a carboxyl group. Among them, polyisocyanate compounds are preferable.

The active energy ray-curable pressure-sensitive adhesive composition has a property of being cured by irradiation with an active energy ray such as ultraviolet ray or electron beam, and has a property of being capable of having adhesiveness even before irradiation with an active energy ray to be in close contact with an adherend such as a film and of being capable of adjusting the adhesion force by curing with irradiation with an active energy ray. The active energy ray-curable adhesive composition is preferably an ultraviolet-curable adhesive composition. The active energy ray-curable adhesive composition further contains an active energy ray-polymerizable compound in addition to the base polymer and the crosslinking agent. The photopolymerization initiator, the photosensitizer and the like may be contained as necessary.

The binder composition may contain additives such as fine particles, beads (resin beads, glass beads, and the like), glass fibers, resins other than the base polymer, tackifiers, fillers (metal powders, other inorganic powders, and the like), antioxidants, ultraviolet absorbers, dyes, pigments, colorants, defoamers, anticorrosion agents, and photopolymerization initiators for imparting light scattering properties.

The organic solvent diluted solution of the adhesive composition may be applied to a substrate and dried. When an active energy ray-curable pressure-sensitive adhesive composition is used, a cured product having a desired degree of curing can be formed by irradiating the formed pressure-sensitive adhesive layer with active energy rays.

When the 1 st adhesive layer 20 is provided at a position in contact with the colored layer 40 (for example, embodiment 1, and embodiments 4 to 6), the thickness is preferably larger than the thickness of the colored layer 40, for example, preferably 3 μm to 100 μm, and more preferably 5 μm to 50 μm, in view of absorbing the step of the colored layer 40.

(Back plate)

The material and thickness are not limited as long as the back panel 30 is a plate-like body that can transmit light, and may be a single layer or a plurality of layers. The thickness of the back plate is preferably 50 μm to 1000 μm. The rear plate may not include the display unit.

As described above, the rear panel 30 may be formed using components used in a general image display device, such as the

polarizing plates

60a and 60c and the touch sensor panel 70. The use of such a component as back surface plate 30 is preferable because the number of components of image display device 300 can be reduced, and image display device 300 can be made thinner.

In the above, the case where the back panel 30 is the

polarizing plates

60a and 60c or the touch sensor panel 70 has been exemplified, but the back panel 30 is not limited to these, and may be a protective film on the visible side of the polarizing plate or a laminate of the polarizing plate and the touch sensor panel.

As the rear panel 30, a glass plate (e.g., a glass plate, a glass film, etc.) or a resin plate (e.g., a resin plate, a resin sheet, a resin film, etc.) may be used as well as the front panel 10. As specific examples of the glass plate-like body and the resin plate-like body, the above description about the front panel 10 can be applied.

(colored layer)

The shape and color of the colored layer 40 are not limited, and can be appropriately selected according to the use and design of the image display device. The colored layer 40 contains a colorant. The colored layer 40 may be formed of a single layer or a plurality of layers. When the colored layer 40 is formed of a plurality of layers, at least one of the plurality of layers is a colorant-containing layer containing a colorant, and the remaining layers may or may not contain a colorant. Examples of the color of the colorant include black, red, white, navy blue, silver, and gold. The colored layer 40 may have a colorant-containing layer having high light-shielding properties, a base layer for improving adhesion, or the like below the colorant-containing layer containing a colorant. In addition, there may be a transparent protective layer covering the colorant-containing layer.

The colorant may be appropriately selected according to the desired color. Examples of the colorant include inorganic pigments such as carbon black such as titanium dioxide, zinc white and acetylene black, iron black, red iron oxide, vermilion, ultramarine, cobalt blue, chrome yellow and titanium yellow; organic pigments or dyes such as phthalocyanine blue, indanthrene blue, isoindolinone yellow, benzidine yellow, quinacridone red, polyazo red, perylene red, aniline black, and the like; metal pigments made of flake foils such as aluminum and brass; a pearl pigment (pearl pigment) comprising a scaly foil such as titanium dioxide-coated mica or basic lead carbonate. In this specification, the metal contained in the plating layer is also contained in the colorant.

Each layer of the colored layer 40 can be formed by a printing method, a coating method, a plating method, or the like. Colored layer 40 may be formed directly on the 1 st surface of back surface plate 30, or may be formed by transferring a layer formed on another substrate onto the 1 st surface. Specific examples of the printing method include gravure printing, offset printing, screen printing, and transfer printing using a transfer sheet. Printing by a printing method can be repeated to obtain a colored layer 40 having a desired thickness. Examples of the ink used in the printing method include inks containing a colorant, a binder, a solvent, and an optional additive.

Examples of the binder include chlorinated polyolefins (e.g., chlorinated polyethylene and chlorinated polypropylene), polyester resins, polyurethane resins, acrylic resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymers, and cellulose resins. The binder resin may be used alone, or 2 or more kinds may be used in combination. The binder resin may be a thermally polymerizable resin or a photopolymerizable resin.

When the colorant-containing layer is formed by a printing method, it is preferable to use an ink containing 50 to 200 parts by mass of a colorant per 100 parts by mass of a binder resin.

Specific examples of the plating method include known plating methods such as electroplating, electroless plating, hot dip plating, chemical vapor deposition, and physical vapor deposition. Examples of physical vapor deposition include vapor deposition systems including methods 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. These methods may be combined with patterning as desired. In this specification, a layer formed by a plating method is referred to as a plating layer.

When the colored layer 40 is provided in the peripheral portion of the back panel 30, the colored layer is not limited to the form provided over the entire periphery of the peripheral portion, and may be provided only in a part of the peripheral portion in accordance with a desired design or the like. When the colored layer 40 is provided in the peripheral portion of the rear plate 30, the width thereof may be appropriately determined depending on the size of the display region, the desired design, and the like, and is preferably in the range of 1mm to 20mm, for example.

(polarizing plate)

Examples of the polarizing plate include a stretched film having a dye having absorption anisotropy adsorbed thereon, and a film containing a polarizer obtained by coating and curing a dye having absorption anisotropy.

Examples of the dye having absorption anisotropy include dichroic dyes. As the dichroic dye, specifically, iodine or a dichroic organic dye can be used. The dichroic organic dye includes a dichroic direct dye composed of a disazo compound such as c.i. direct RED 39, and a dichroic direct dye composed of a compound such as trisazo or tetraazo. Examples of the film used as a polarizer and coated with a dye having absorption anisotropy include a stretched film having a dye having absorption anisotropy adsorbed thereon, and a film having a layer obtained by coating and curing a composition containing a dichroic dye having liquid crystallinity or a composition containing a dichroic dye and a polymerizable liquid crystal. A film coated with a dye having absorption anisotropy and cured is preferable because it is not limited in the bending direction as compared with a stretched film having an absorbed dye having absorption anisotropy.

(1) Polarizing plate having stretched film as polarizer

A polarizing plate including a stretched film having a dye having anisotropy adsorbed thereon as a polarizer will be described. A stretched film as a polarizer, to which a dye having absorption anisotropy is adsorbed, is generally produced through the following steps: a step of uniaxially stretching a polyvinyl alcohol resin film; a step of dyeing a polyvinyl alcohol resin film with a dichroic dye, thereby adsorbing the dichroic dye; and a step of treating the polyvinyl alcohol resin film having the dichroic dye adsorbed thereon with an aqueous boric acid solution; and a step of washing with water after the treatment with the boric acid aqueous solution. The polarizer may be used as it is, or a laminate having a transparent protective film attached to one or both surfaces thereof may be used as the polarizing plate. The thickness of the polarizer thus obtained is preferably 2 to 40 μm.

The polyvinyl alcohol resin can be obtained by saponifying a polyvinyl acetate 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 may be used. Examples of the other monomer 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 resin is usually about 85 to 100 mol%, and preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, and for example, polyvinyl formal or polyvinyl acetal obtained by modifying aldehydes may be used. The polymerization degree of the polyvinyl alcohol resin is usually about 1000 to 10000, and preferably in the range of 1500 to 5000.

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

The uniaxial stretching of the polyvinyl alcohol resin film may be performed before, simultaneously with, or after the dyeing with the dichroic dye. In the case of uniaxial stretching after dyeing, the uniaxial stretching may be performed before boric acid treatment or may be performed during boric acid treatment. In addition, uniaxial stretching can be performed at these multiple stages. In the case of uniaxial stretching, the stretching may be performed uniaxially between rolls having different peripheral speeds, or uniaxially by using a heat roll. The uniaxial stretching may be dry stretching in which stretching is performed in the air, or wet stretching in which stretching is performed in a state where the polyvinyl alcohol resin film is swollen with a solvent. The draw 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, and examples thereof include films known in the art, such as a cyclic polyolefin resin film, a cellulose acetate resin film made of a resin such as cellulose triacetate and cellulose diacetate, a polyester resin film made of a resin such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, a polycarbonate resin film, a (meth) acrylic resin film, and a polypropylene resin film. From the viewpoint of light 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, preferably 20 μm or more. The protective film may or may not have a phase difference.

(2) Polarizing plate having polarizer made of film formed of liquid crystal layer

A polarizing plate including a film formed of a liquid crystal layer as a polarizer will be described. Examples of the film used as a polarizer and coated with a dye having absorption anisotropy include a film obtained by applying a composition containing a dichroic dye having liquid crystallinity or a composition containing a dichroic dye and a liquid crystal compound to a substrate and curing the applied composition. The film may be used as a polarizing plate by peeling off a substrate or using the film together with a substrate, or may be used as a polarizing plate having a protective film on one surface or both surfaces thereof. Examples of the protective film include those similar to polarizing plates provided with the stretched film as a polarizer.

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

Specific examples of the film coated with the dye having absorption anisotropy include films described in japanese patent application laid-open nos. 2013-37353 and 2013-33249.

The polarizing plate may further include a retardation film. The retardation film may include 1 or 2 or more retardation layers. The retardation layer may be a positive A plate or a positive C plate such as a λ/4 plate or a λ/2 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 include an alignment film or a substrate film.

(touch sensor panel)

The touch sensor panel is not limited to a detection method as long as it is a sensor capable of detecting a touched position, and examples thereof include touch sensor panels of a resistive film method, a capacitive coupling method, an optical sensor method, an ultrasonic wave method, an electromagnetic induction coupling method, a surface acoustic wave method, and the like. Since the cost is low, a resistive touch sensor panel or a capacitive touch sensor panel is preferably used.

An example of a resistive touch sensor panel includes a pair of substrates arranged to face each other, an insulating spacer sandwiched between the pair of substrates, a transparent conductive film as a resistive film provided on the front surface of the inner side of each substrate, and a touch position detection circuit. In an image display device provided with a resistive touch sensor panel, when the surface of the front panel 10 is touched, the opposing resistive films are short-circuited, and a current flows through the resistive films. The touch position detection circuit detects a change in voltage at that time, and detects the touched position.

An example of a capacitive coupling type touch sensor panel includes a substrate, a position detection transparent electrode 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 front panel 10 is touched, the transparent electrode is grounded via the capacitance of the human body at the touched point. The touch position detection circuit detects the grounding of the transparent electrode and detects the touched position.

The touch sensor panel may be a panel of the resistive film type or the capacitive coupling type, for example, formed on a substrate layer with a separator layer interposed therebetween, or may be configured to be separated between the substrate layer and the separator layer so that the separator layer is exposed on the outermost surface.

(Barrier layer)

The shielding layer 50 is preferably provided so as to correspond to the colored layer 40, and the width of the shielding layer 50 in the plane direction is preferably almost the same as the width of the colored layer 40 in the plane direction. The barrier layer contains a colorant. The colorant preferably contains a colorant having a high function of increasing optical density, and for example, preferably contains a black pigment such as carbon black or iron black. The shielding layer 50 may be formed of a single layer or a plurality of layers. When the optical laminate includes the shielding layer, the colored layer is present between the front panel and the shielding layer.

The shielding layer 50 can be formed by a printing method, a coating method, or the like. The shielding layer 50 may be formed directly on the 2 nd surface of the back panel 30, or may be formed by transferring a layer formed on another substrate to the 2 nd surface. The above description of the colored layer 40 is applied to the printing method.

(second adhesive layer)

The 2 nd adhesive layer 21 is an adhesive layer or an adhesive layer. When the 2 nd adhesive layer 21 is provided at a position in contact with the colored layer 40 or the shielding layer 50, an adhesive layer is preferable in terms of absorbing the step difference therebetween. The above description of the 1 st laminated layer 20 is applied as a material of the 2 nd laminated layer 21.

[ method for producing optical laminate ]

The method for producing an optical laminate of the present invention includes a laminating step of laminating a back plate, a bonding layer, and a front plate to obtain an optical laminate, and further includes a coloring layer forming step of forming a coloring layer on a part of the 1 st surface or the 2 nd surface of the back plate before the laminating step.

Fig. 12 is a sectional view schematically showing an example of the method for manufacturing the optical laminate 100' shown in fig. 2. The manufacturing method shown in fig. 12 includes: a step of preparing back plate 30 (fig. 12 a); a coloring layer forming step of forming a coloring layer 40 on the 1 st surface of the rear plate 30 (fig. 12 (b)); a mask layer forming step of forming a mask layer 50 on the 2 nd surface of the back panel 30 (fig. 12 (b)); a laminating step of laminating the rear panel 30 on which the coloring layer 40 and the shielding layer 50 are formed, the 1 st laminating layer 20, and the front panel 10 to obtain an optical laminate 100' (fig. 12 (e)). The method of forming the colored layer is as described above. The shielding layer forming step of forming the shielding layer 50 on the No. 2 surface of the back panel 30 may be performed after the laminating step (fig. 12 (e)).

The method may further include a step of preparing the front panel 10 (fig. 12 c) and a step of providing the 1 st bonding layer 20 on the surface of the front panel 10 (fig. 12 d) before the laminating step (fig. 12 e). According to the above-described manufacturing method, the generation of bubbles in the 1 st adhesive layer 20 layer can be suppressed by setting the thickness of the colored layer 40 to 13 μm or less.

When the back panel 30 is a polarizing plate, the back panel (a laminate obtained in fig. 12(b)) obtained in an intermediate stage of the above-described manufacturing method and having the colored layer 40 and the shielding layer 50 formed thereon becomes a polarizing plate with a colored layer. The 1 st surface of the back panel 30 is the visible side surface of the polarizer. The polarizing plate with a colored layer is used to obtain the optical laminate 100 in which the generation of bubbles is suppressed as described above.

Fig. 13 is a sectional view schematically showing an example of the method for manufacturing the optical laminate 100 shown in fig. 1. The manufacturing method shown in fig. 13 is different from the manufacturing method shown in fig. 12 only in that the mask layer forming step for forming the mask layer 50 is not performed. When the back panel 30 is a polarizing plate, the back panel having the colored layer 40 formed thereon obtained in the intermediate stage of the above-described manufacturing method (the laminate obtained in fig. 13(b)) is a polarizing plate with a colored layer.

[ use of image display device ]

The image display device according to the present invention can be used for mobile devices such as smartphones and tablets, televisions, digital cameras, electronic billboards, measuring instruments and meters, business machines, medical machines, and computing machines. According to the present invention, it is possible to suppress the generation of bubbles in the 1 st adhesive layer 20 which is easily visible, and thus it is possible to provide a high-quality image display device in which the generation of defects in appearance is suppressed.

Examples

The present invention will be described in further detail with reference to examples, but the present invention is not limited to these examples.

< preparation of composition for Forming colorant-containing layer (Black) >

[ ink Components ]

Acetylene black 15% by mass

75% by mass of polyester

2.5% by mass of dimethyl glutamate

Succinic acid 2% by mass

Isofluorone 5.5% by mass

[ curing agent ]

75% by mass of aliphatic polyisocyanate

25% by mass of ethyl acetate

[ solvent ]

Isofluorone

[ production method ]

The curing agent 10 parts by mass and the solvent 10 parts by mass were added to 100 parts by mass of the ink components, and the mixture was stirred to obtain a colorant layer-containing composition (black color).

< preparation of composition for Forming colorant-containing layer (white) >

[ ink Components ]

Titanium dioxide 50% by mass

39% by mass of a polyester

2.5% by mass of dimethyl glutamate

Succinic acid 2% by mass

Isofluorone 6.5% by mass

[ curing agent ]

75% by mass of aliphatic polyisocyanate

25% by mass of ethyl acetate

[ solvent ]

Isofluorone

[ production method ]

The curing agent 10 parts by mass and the solvent 10 parts by mass were added to 100 parts by mass of the ink components, and the mixture was stirred to obtain a colorant-containing layer-forming composition (white).

< preparation of composition for Forming protective layer (transparent) >

[ ink Components ]

90% by mass of polyester

2.5% by mass of dimethyl glutamate

Succinic acid 2% by mass

Isofluorone 5.5% by mass

[ curing agent ]

75% by mass of aliphatic polyisocyanate

25% by mass of ethyl acetate

[ solvent ]

Isofluorone

[ production method ]

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

< example 1 >

(preparation of Window film with adhesive layer)

The optical laminate of example 1 was produced in the order shown in fig. 12. Specifically, a window film having a thickness of 70 μm (50 μm base film, 10 μm hard coat layers, 177mm in length × 105mm in width) having hard coat layers formed on both surfaces of the base film was prepared as the front panel 10 (fig. 12(c)), and a (meth) acrylic pressure-sensitive adhesive layer (25 μm in thickness, 177mm in length × 105mm in width) was prepared as the 1 st adhesive layer 20. The base film of the window film is a polyimide resin film, and the hard coat layer is a layer formed from a composition containing a dendritic polymer compound having a polyfunctional acrylic group at the end. Thereafter, the surface of the window film that is bonded to the adhesive layer and the surface of the adhesive layer that is bonded to the window film are subjected to corona treatment. Then, the window film and the adhesive layer are bonded to each other to obtain a window film with an adhesive layer (fig. 12 (d)).

(preparation of polarizing plate)

After a photo-alignment film was formed on a substrate, a composition containing a dichroic dye and a polymerizable liquid crystal compound was applied to the substrate, and the substrate was aligned and cured to obtain a polarizer having a thickness of 2 μm. A cellulose Triacetate (TAC) film having a thickness of 25 μm was bonded to the polarizer via an adhesive layer. The substrate was peeled off, and a retardation film (thickness 17 μm, layer composition: protective film 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) comprising layer cured of liquid crystal compound and alignment film was formed on the exposed surface. The polarizing plate thus produced (layer composition of "TAC/polarizer/retardation film", thickness 44 μm, longitudinal 177mm × transverse 105mm) was prepared as the back plate 30 (fig. 12 (a)).

(formation of coloring layer and shielding layer)

Next, on the surface of the TAC of the polarizing plate (the 1 st surface of the back plate), the prepared colorant layer-forming composition (black) was used as an ink, and printing was performed by screen printing using a 460-mesh screen, after drying, with a discharge amount of 3 μm thick, and a colored layer 40 composed of a black printed layer having a thickness of 3 μm and a width of 5mm was formed over the entire circumference of the peripheral portion (fig. 12 (b)). Further, a shielding layer 50 composed of a black printed layer (3 μm thick) was formed on the surface of the retardation film of the polarizing plate (the 2 nd surface of the rear plate) by the same method as the coloring layer 40 (fig. 12 (b)).

(production of optical layered body)

Then, the surface of the adhesive layer of the window film with the adhesive layer and the TAC side surface of the polarizing plate were subjected to corona treatment, and the window film with the adhesive layer and the polarizing plate were laminated so that the corona-treated surface was on the inner side, and were bonded to each other using a roll bonder and subjected to aging treatment in an autoclave, thereby obtaining an optical laminate of example 1 (fig. 12 (e)).

The corona treatment was carried out under the following conditions.

Frequency: 20 kHz/Voltage: 8.6 kV/power: 2.5 kW/speed: 6 m/min

< example 2 >

An optical laminate of example 2 was obtained in the same manner as in example 1 except that the colored layer 40 and the shielding layer 50 were formed as follows, the colored layer 40 was constituted by a gold vapor-deposited layer and a transparent protective layer, and the shielding layer 50 was constituted by 2 black printed layers (each black printed layer having a thickness of 3 μm), and (fig. 12 (e)).

TiO was deposited on the TAC surface (No. 1 surface of the back plate) of the polarizer by using an electron beam deposition apparatus (product name: UNIVAC2050, manufactured by UNIVAC corporation)₂As a vapor deposition source, is formed

On which In is formed as a deposition source

On which TiO is deposited₂Formed as a vapor deposition sourceA vapor deposition layer of thickness of (1), on which Al is deposited₂O₃Formed as a vapor deposition source

The thickness of (3) is as small as possible. Thus, a gold vapor-deposited layer (thickness < 1 μm) composed of 4 layers was formed. Thereafter, in the colored layer formation region, the gold vapor deposition layer in the region where the protective layer was not formed was removed by etching by printing with a screen printing of 460 mesh using the prepared protective layer forming composition (transparent) as an ink and a coating thickness of 5 μm after drying. Thus, a colored layer 40 having a layer structure of "gold vapor deposition layer (thickness < 1 μm)/protective layer (thickness 5 μm)" (entire thickness is more than 5 μm and less than 6 μm) is formed over the entire periphery of the peripheral portion (fig. 12 (b)).

Next, on the surface of the retardation film of the polarizing plate (the 2 nd surface of the back sheet), the same printing as that in the formation of the shielding layer in example 1 was performed 2 times, and the shielding layer 50 having a layer structure of "black printed layer (thickness 3 μm)/black printed layer (thickness 3 μm)" (thickness 6 μm as a whole) was formed (fig. 12 (b)).

< example 3 >

An optical laminate of example 3 was obtained in the same manner as in example 1 except that the colored layer 40 and the shielding layer 50 were formed as follows, and the colored layer 40 was constituted by 3 white printed layers (each white printed layer having a thickness of 3 μm) and the shielding layer 50 was constituted by 2 black printed layers (each black printed layer having a thickness of 3 μm) (fig. 12 (e)).

On the TAC surface of the polarizing plate (the 1 st surface of the back sheet), the same printing as that in the formation of the colored layer in example 1 was performed 3 times using the prepared colorant layer-forming composition (white), and a colored layer 40 having a layer structure of "white printed layer (thickness 3 μm)/white printed layer (thickness 3 μm)" (thickness of the whole 9 μm) was formed (fig. 12 (b)).

< example 4 >

An optical laminate of example 4 was obtained in the same manner as in example 1 except that the colored layer 40 was formed in the following manner without forming the shielding layer 50 (fig. 13 (e)).

On the TAC surface of the polarizing plate (the 1 st surface of the back surface plate), the same printing as that in the formation of the colored layer in example 1 was performed 2 times, and a colored layer 40 having a layer configuration of "black printed layer (thickness 3 μm)/black printed layer (thickness 3 μm)" (thickness 6 μm as a whole) was formed (fig. 13 (b)).

< example 5 >

An optical laminate of example 5 was obtained in the same manner as in example 1, except that the colored layer 40 was formed as follows and the shielding layer 50 was not formed.

On the surface of the retardation film of the polarizing plate (the 2 nd surface of the back plate), the same printing as that in the case of forming the colored layer of example 1 was performed 2 times, and the colored layer 40 having a layer structure of "black printed layer (thickness 3 μm)/black printed layer (thickness 3 μm)" (thickness 6 μm as a whole) was formed.

< example 6 >

A laminate was obtained by laminating a window film with an adhesive layer and a polarizing plate in the same manner as in example 1, except that the colored layer 40 and the shielding layer 50 were not formed on the surface of the polarizing plate. The touch sensor panel with a colored layer prepared in advance was bonded to the polarizer side of the laminate via the 2 nd bonding layer so that the colored layer 40 side was on the inner side, thereby obtaining an optical laminate of example 6 (optical laminate 106 in fig. 8). As the 2 nd adhesive layer, the same (meth) acrylic adhesive layer (thickness 25 μm, 177mm in length × 105mm in width) as that of the 1 st adhesive layer was used.

In this embodiment, a touch sensor panel configured as follows was manufactured: a separation layer, a patterned electrode layer, and an insulating layer covering the electrode layer are sequentially stacked on a base layer, and the separation layer is separated between the base layer and the separation layer to expose the separation layer on the outermost surface. The touch sensor panel thus produced (layer structure of "insulating layer/electrode layer/separation layer", thickness 7 μm, longitudinal 177mm × lateral 105mm) was prepared as a back plate. Next, on the surface of the separation layer of the touch sensor panel (the 1 st surface of the back sheet), the same printing as that in the case of forming the colored layer in example 1 was performed 2 times to form the colored layer 40 having a layer configuration of "black printed layer (thickness 3 μm)/black printed layer (thickness 3 μm)" (thickness 6 μm as a whole), and a colored layer-attached touch sensor panel was obtained.

< example 7 >

An optical laminate of example 7 was obtained in the same manner as in example 1 except that the colored layer 40 was formed as follows and the shielding layer 50 was not formed (fig. 13 (e)).

On the TAC surface of the polarizing plate, "black printed layer (thickness 3 μm)/black printed layer (thickness 3 μm)" was formed by performing 2 times the same printing as that in the formation of the colored layer in example 1. On this, by the same method as in example 2, a colored layer 40 (the entire thickness exceeds 11 μm and is less than 12 μm) of a layer composition of "gold vapor-deposited layer (thickness < 1 μm)/protective layer (thickness 5 μm)", and "black printed layer (thickness 3 μm)/gold vapor-deposited layer (thickness < 1 μm)/protective layer (thickness 5 μm)" was formed (fig. 13 (e)).

< comparative example 1 >

An optical laminate of comparative example 1 was obtained in the same manner as in example 1 except that the coloring layer 40 was formed in the following manner without forming the shielding layer 50 (fig. 12 (e)).

On the TAC surface of the polarizing plate, "black printed layer (thickness 3 μm)/black printed layer (thickness 3 μm)" was formed by performing 2 times the same printing as that in the formation of the colored layer in example 1. On the printed layer, the same printing as that in the case of the colored layer formation of example 3 was performed, and a colored layer 40 (15 μm in thickness as a whole) having a layer structure of "white printed layer (3 μm in thickness)/white printed layer (3 μm in thickness)" and "black printed layer (3 μm in thickness)/white printed layer (3 μm in thickness)" was formed (fig. 12 (e)).

[ measurement of Optical Density ]

Samples each composed of a layer of "substrate/colored layer" in which a colored layer was formed on a substrate (polarizing plate produced in example 1) in the same order as in each example and comparative example were prepared, and each sample was cut into 5cm × 5cm to be used as a measurement sample for optical density measurement in each example and comparative example. The measurement sample was placed in an optical density measuring instrument (product name: 361T, manufactured by X-rite Co., Ltd.), a light source located on the upper portion of the measurement sample on the coloring layer side was turned on to focus on the coloring layer of the measurement sample, the light source located on the base material side of the measurement sample was turned off, and then a light source for measurement was turned on to measure the optical density with the coloring layer as a measurement area. Table 1 shows the measurement results.

[ evaluation of bubble Generation ]

The optical laminates of examples 1 to 7 and comparative example 1 were evaluated with respect to the occurrence of bubbles by visual observation according to the following criteria. The evaluation results are shown in table 3.

A: no air bubbles were observed immediately after the attachment,

b: although a slight amount of bubbles were observed immediately after bonding, no bubbles were observed after autoclave treatment,

c: bubbles were observed only in the periphery (non-display area) of the colored layer in the laminating layer,

d: bubbles were observed in the periphery (non-display area) and the display area of the colored layer in the adhesive layer.

[ evaluation of bendability ]

The optical laminates of examples 1 to 7 and comparative example 1 were fixed in a bending tester (CFT-720C, manufactured by Covotech corporation), and then a bending test was performed so that the front panel was on the inside and the distance between films at the time of bending was 5.0mm (2.5R). Thereafter, based on the number of times of bending when cracks were generated in the bent portion and the adhesive floated (hereinafter referred to as "number of times of bending with failure").

A: the bending times are more than 20 ten thousand times under the unfavorable condition,

b: the number of times of bending is 10 ten thousand or more and less than 20 ten thousand or less,

c: the number of times of bending is more than 5 ten thousand and less than 10 ten thousand under bad conditions,

d: the number of times of bending is less than 5 ten thousand times when the defect occurs.

[ evaluation of step Difference ]

The optical layered bodies of examples 1 to 7 and comparative example 1 were measured for the difference between the highest height and the lowest height of the outermost surface of the front panel, and based on the difference, the following judgment was made.

A: less than 50 μm, and is suitable for use in,

b: 50 μm or more and less than 100 μm,

c: 100 μm or more and less than 500 μm,

d: more than 500 μm.

[ Table 1]

[ Table 2]

[ Table 3]

	Bubble generation	Flexibility	Step difference
				Example 1	A	B	A
Example 2	A	B	B
				Example 3	B	B	B
Example 4	B	B	B
				Example 5	A	B	B
Example 6	A	A	A
				Example 7	C	B	C
Comparative example 1	D	D	D

Conform to the description

10 front panel, 20 first laminating layer, 21 second laminating layer, 30 back panel, 40 coloring layer, 50 shielding layer, 60a, 60b, 60c polarizer, 70 touch sensor panel, 81 liquid crystal display unit, 82 organic EL display unit, 90 backlight unit, 100, 100', 101, 102, 103, 104, 105, 106 optical laminate, 200 display laminate, 300 image display device, 301, 302 liquid crystal display device, 303, 304 organic EL display device, 305, 306 flexible display.

Claims

1. An optical laminate comprising a front plate, a bonding layer and a back plate in this order in the lamination direction,

further comprising a colored layer provided on a 1 st surface of the back surface plate on the side of the bonding layer or a part of a 2 nd surface on the side opposite to the 1 st surface,

the thickness of the colored layer is 13 [ mu ] m or less,

the use is configured in such a manner that the front panel is located in front of the image display apparatus.

2. The optical laminate according to claim 1, further comprising a blocking layer which is not in contact with the colored layer,

3. The optical stack according to claim 2, wherein the thickness of the blocking layer is from 1 μm to 13 μm.

4. The optical stack according to claim 2 or 3, wherein the blocking layer comprises a black pigment.

5. The optical laminate according to any one of claims 1 to 4, wherein the optical laminate is divided into a display region and a non-display region in a plane direction orthogonal to the lamination direction,

the colored layer is provided in the non-display region,

the optical density of the non-display region is 3 or more.

6. The optical stack according to any one of claims 1 to 5, wherein the front sheet is a resin film.

7. The optical stack of any of claims 1-6, wherein the back panel comprises a polarizer.

8. An image display device comprising the optical laminate according to any one of claims 1 to 7, wherein the front panel is disposed on the front surface.

9. A polarizing plate with a colored layer is provided with:

a polarizing plate, and

a colored layer provided on a part of a surface on a visible side of the polarizing plate;

the colored layer has a thickness of 13 μm or less.

10. The colored-layer-attached polarizing plate according to claim 9, further comprising a shielding layer on a surface of the polarizing plate on the opposite side to the surface on the visible side,

the shielding layer is provided on the colored layer with the polarizing plate interposed therebetween.

11. A method for producing the optical laminate according to claim 1, comprising a lamination step of laminating the back surface plate, the adhesive layer, and the front surface plate to obtain the optical laminate,

the method further includes a coloring layer forming step of forming the coloring layer on the 1 st surface or a part of the 2 nd surface of the rear panel before the laminating step.

12. A method of manufacturing the optical stack of claim 2, comprising:

a laminating step of laminating the back surface plate, the adhesive layer, and the front surface plate to obtain the optical laminate, and

a coloring layer forming step of forming the coloring layer on a part of the 1 st surface of the rear panel before the laminating step;

and a shielding layer forming step of forming the shielding layer on the 2 nd surface of the rear panel.