TWI875949B - Optical laminate with adhesive layer and image display device, and manufacturing method thereof - Google Patents

Abstract

The present invention provides an optical multilayer with an adhesive layer, which can realize an image display device with high functions and a large display portion ratio without reducing the yield. The optical multilayer with an adhesive layer of the present invention has: an optical film; a first adhesive layer formed on one side of the optical film; and a second adhesive layer formed on the other side of the optical film. The optical multilayer with an adhesive layer has a through hole that integrally penetrates the first adhesive layer, the optical film, and the second adhesive layer.

Description

Optical laminate with adhesive layer and image display device, and manufacturing method thereof

The present invention relates to an optical multilayer body and an image display device with an adhesive layer, and a method for manufacturing the same.

Optical laminates including optical films such as polarizing elements and phase difference plates are used in image display devices such as smartphones, tablet terminals, and notebook personal computers (PCs). In recent years, image display devices have gradually become more functional, with various functions such as cameras, speakers, and various sensors. In addition, image display devices have gradually become full-screen displays. However, since the entire screen is used as a display, an optical laminate is also configured on the upper part of the portion where the above-mentioned camera, speaker, and various sensors are configured, and there is a situation where these required functions cannot be fully exerted. Therefore, an optical laminate having an opening portion formed in a manner corresponding to the portion having these functions is disclosed (Patent Document 1).

Optical laminates are usually bonded to other components via an adhesive layer. When an optical laminate with an opening is bonded to other components via an adhesive layer, it is difficult to align the components of the image display device, which reduces the yield. Therefore, there is a need to design to increase the non-display area, making it difficult to achieve full-screen display.

Prior art literature Patent Literature

Patent document 1: Japanese Patent Publication No. 2014-112238

This invention is made to solve the above-mentioned previous problems. Its main purpose is to provide an optical multilayer body with an adhesive layer, which can realize a high-function image display device with a larger display ratio without reducing the yield.

The optical laminate with adhesive layer of the present invention comprises: an optical film; a first adhesive layer formed on one side of the optical film; and a second adhesive layer formed on the other side of the optical film. The optical laminate has a through hole that integrally penetrates the first adhesive layer, the optical film and the second adhesive layer.

In one embodiment, the optical film is at least one selected from the group consisting of a polarizing plate, a phase difference film, a conductive film for a touch panel, a pressure-sensitive film, and a transparent plastic film.

In another embodiment of the present invention, a method for manufacturing an optical laminate with an adhesive layer is provided. The method for manufacturing the optical laminate includes the following steps: forming a first adhesive layer on one side of an optical film; forming a second adhesive layer on the other side of the optical film; and forming a through hole that integrally connects the first adhesive layer, the optical film, and the second adhesive layer.

According to the present invention, an optical multilayer with an adhesive layer is provided, which can realize an image display device with high functionality and a large display portion ratio without reducing the yield. The optical multilayer with an adhesive layer of the present invention has: an optical film; a first adhesive layer formed on one surface of the optical film; and a second adhesive layer formed on the other surface of the optical film. The optical multilayer with an adhesive layer of the present invention has a through hole that integrally penetrates the first adhesive layer, the optical film, and the second adhesive layer. By using the optical multilayer with an adhesive layer of the present invention, even when a camera, speaker, and various sensors are arranged in the display portion of an image display device, alignment is easy, which can improve the yield. Therefore, an image display device with a larger display area ratio (such as a full-screen display image display device) can also be realized.

10: Optical film

20: 1st adhesive layer

30: Second adhesive layer

40: Isolation film

50:Through hole

100: Optical laminate with adhesive layer attached

140: Glass layer or plastic layer

150: Display panel

200: Image display device

FIG1 is a schematic cross-sectional view of an optical laminate with an adhesive layer in one embodiment of the present invention.

Figure 2 is a schematic cross-sectional view of an image display device in one embodiment of the present invention.

The following describes the implementation methods of the present invention, but the present invention is not limited to these implementation methods.

A. Overall composition of optical laminate with adhesive layer attached

FIG1 is a schematic cross-sectional view of an optical laminate with adhesive layers in one embodiment of the present invention. The optical laminate with adhesive layers 100 shown in the figure has: an optical film 10; a first adhesive layer 20 formed on one surface of the optical film 10; and a second adhesive layer 30 formed on the other surface of the optical film 10. In terms of practicality, in order to properly protect the first adhesive layer 20 and the second adhesive layer 30 before use, a separation film 40 is temporarily and releasably adhered to the adhesive layers. The optical laminate 100 with adhesive layer has through holes 50 that integrally penetrate the optical film 10, the first adhesive layer 20, and the second adhesive layer 30. The through holes 50 are formed in a manner to correspond to the position, size, number, and shape of the camera, speaker, and various sensors mounted in the image display device. By making the optical laminate 100 with adhesive layer have such through holes 50, when the optical film is attached to other components, the optical film will not be misaligned with each adhesive layer, and alignment is easy. Furthermore, since the through hole 50 is formed in a manner corresponding to the camera, speaker, and various sensors, the functions of these devices can be fully exerted without being hindered by the optical film and adhesive layer. Typically, the optical multilayer body with an adhesive layer can be arranged in an image display device in a manner that the first adhesive layer becomes the viewing side of the image display device.

The through hole 50 is formed in any appropriate shape and size. As the shape of the through hole (shape when viewed from above), for example, a circular shape, a rectangular shape, etc. can be cited. When forming a circular through hole, for example, a through hole with a diameter of 1mm to 30mm is formed. The through hole can be a through hole that penetrates the optical multilayer in the form of a column such as a cylinder or a polygonal column, or a through hole that penetrates the optical multilayer in the form of a cone, i.e., a pyramid. In addition, the size of the through hole in each layer, such as the adhesive layer and the optical film, can also be different.

In one embodiment, the through hole is a through hole that penetrates the optical multilayer in a tapered shape. In order to improve the design of smart phones, perforated type is widely used as a setting method for the front camera. Due to the high demand for selfies, the front camera is required to have a wider angle and a larger aperture. On the other hand, in order to hide the cut surface of the hole or prevent light leakage from the display, black frame printing is required, but the expansion of the non-display area will reduce the design. By making the through hole tapered, a wide angle when configuring the camera and the hiding of the hole end can be achieved, and the black frame printing and the non-display area can be reduced. When the through hole is tapered, the size of the top view shape of the through hole on the outermost surface of the first adhesive layer (hereinafter, also referred to as the planar shape of the first through hole) and the top view shape of the through hole on the outermost surface of the second adhesive layer (hereinafter, also referred to as the planar shape of the second through hole) can be designed to have any appropriate difference. For example, when the planar shape of the through hole is circular, the difference between the diameter of the planar shape of the first through hole and the diameter of the planar shape of the second through hole is preferably 5μm to 500μm, more preferably 10μm to 250μm, and further preferably 20μm to 150μm. For example, when the planar shape of the through hole is rectangular or elliptical, the difference between the size of the planar shape of the first through hole (e.g., the length of one side, the minor diameter, the major diameter, etc.) and the size of the planar shape of the second through hole (e.g., the length of one side, the minor diameter, the major diameter, etc.) is preferably 5μm~500μm, more preferably 10μm~250μm, and further preferably 20μm~150μm. As for the difference in the size of the planar shape of the through hole, as long as the smallest difference is within the above range, it is sufficient. Furthermore, the planar shape of the first through hole and the planar shape of the second through hole can be different shapes or the same shape (i.e., similar shapes).

In one embodiment, the difference in size between the planar shape of the first through hole and the planar shape of the second through hole is preferably less than 500μm, more preferably less than 300μm, and further preferably less than 150μm. In order to improve the design of smart phones, perforation type is widely used as a setting method for the front camera. It is better to reduce the hole diameter in design, but due to the misalignment of the components when bonding or the uneven size of the through holes, there is a problem that the width of the black frame printing must be increased. By making the difference in the planar shape of the first through hole and the planar shape of the second through hole within the above range, the width of the black frame printing can be reduced, thereby improving the design.

In this embodiment, the planar shape of the first through hole can be larger, and the planar shape of the second through hole can also be larger. When the planar shape of the first through hole is larger than the planar shape of the second through hole, that is, when the planar shape of the through hole on the viewing side is larger, for example, when the through holes are arranged in a manner corresponding to the camera part, the camera can be widened and the hole end can be hidden, and the black frame printing and non-display area can be reduced. Furthermore, when the planar shape of the first through hole is smaller than the planar shape of the second through hole, that is, when the top view shape of the through hole on the viewing side is smaller, for example, when the through hole is arranged in a manner corresponding to the camera unit, the black frame printing and non-display area can be reduced to improve the design. Furthermore, the distance between the camera module and the viewing side can be shortened to achieve a wide angle, and interference with the camera module can be prevented.

In one embodiment, the through holes formed on the first adhesive layer and the second adhesive layer are preferably larger in size in top view than the through holes formed on the optical film. When the optical laminate with adhesive layer having through holes is bonded to an adherend, the adhesive may protrude into the through holes due to the pressure during bonding, resulting in a reduction in appearance quality or damage to the function of sensors such as cameras. The distance between the end of the through hole formed on the first adhesive layer and the second adhesive layer and the end of the through hole formed on the optical film is preferably 5 μm to 1000 μm, more preferably 10 μm to 500 μm, and further preferably 20 μm to 250 μm. By making the distance between the end of the through hole formed on the first adhesive layer and the second adhesive layer and the end of the through hole formed on the optical film within the above range, an optical laminate having excellent appearance and being able to well perform the function of a sensor such as a camera can be obtained. The distance between the end of the through hole formed on the first adhesive layer and the end of the through hole formed on the optical film and the distance between the end of the through hole formed on the second adhesive layer and the end of the through hole formed on the optical film may be the same or different.

In the example shown in the figure, the through hole 50 is formed in a manner that also penetrates the isolation film 40, but the through hole may not be formed in the isolation film 40. In addition, the isolation film 40 can be any material that can properly protect the first adhesive layer and the second adhesive layer before use, and may be the same shape as the optical film, the first and second adhesive layers, or may be a shape and size different from the optical film, the first and second adhesive layers.

Any appropriate surface treatment layer may be provided between the optical film 10 and the first adhesive layer 20 according to the purpose. Examples of the surface treatment layer include a hard coating layer, an anti-reflection layer, an anti-glare layer, and an antidazzle layer.

The optical film 10, the first adhesive layer 20, and the second adhesive layer 30 are described in detail below.

B. Optical film

As the optical film 10, any appropriate optical film can be used. The optical film can be a film composed of a single layer or a laminate. Specific examples of optical films composed of a single layer include polarizing elements and phase difference films. Specific examples of optical films composed of a laminate include polarizing plates (typically, laminates of polarizing elements and protective films), conductive films for touch panels, surface treatment films, pressure-sensitive films, and laminates in which the optical films composed of a single layer and/or optical films composed of a laminate are appropriately laminated according to the purpose (e.g., circular polarizing plates for antireflection, polarizing plates with conductive layers for touch panels). As an example, the polarizing plate is described in detail below. The optical film is preferably at least one selected from the group consisting of a polarizing plate, a phase difference film, a conductive film for a touch panel, a pressure-sensitive film, and a transparent plastic film (such as cycloolefin resin, polyethylene terephthalate resin, acrylic resin, polycarbonate resin, etc.).

B-1. Polarized version

Polarizing plates typically include polarizing elements and protective films. The above-mentioned surface treatment layer may be further provided depending on the application, etc.

B-1-1. Polarizing element

The polarizing element typically includes a resin film containing a dichroic substance. As the resin film, any appropriate resin film that can be used as a polarizing element can be adopted. The resin film is typically a polyvinyl alcohol-based resin (hereinafter referred to as "PVA-based resin") film.

As the PVA resin for forming the above-mentioned PVA resin film, any appropriate resin can be used. For example, polyvinyl alcohol and ethylene-vinyl alcohol copolymer can be cited. Polyvinyl alcohol can be obtained by saponifying polyvinyl acetate. Ethylene-vinyl alcohol copolymer can be obtained by saponifying ethylene-vinyl acetate copolymer. The saponification degree of PVA resin is usually 85 mol%~100 mol%, preferably 95.0 mol%~99.95 mol%, and further preferably 99.0 mol%~99.93 mol%. The saponification degree can be calculated according to JIS K 6726-1994. By using a PVA resin with such a saponification degree, a polarizing element with excellent durability can be obtained. When the saponification degree is too high, there is a risk of gelation.

The average degree of polymerization of PVA-based resins can be appropriately selected according to the purpose. The average degree of polymerization is usually 1000~10000, preferably 1200~4500, and more preferably 1500~4300. In addition, the average degree of polymerization can be obtained according to JIS K 6726-1994.

As dichroic substances contained in the resin film, for example, iodine, organic dyes, etc. can be cited. These can be used alone or in combination of two or more. It is preferred to use iodine.

The resin film can be a single layer of resin film or a laminate of two or more layers.

As a specific example of a polarizing element including a single-layer resin film, one can cite a PVA-based resin film subjected to a dyeing treatment using iodine and a stretching treatment (typically uniaxial stretching). The above-mentioned dyeing using iodine is performed, for example, by immersing the PVA-based resin film in an iodine aqueous solution. The stretching ratio of the above-mentioned uniaxial stretching is preferably 3 to 7 times. Stretching can be performed after the dyeing treatment, or it can be performed while dyeing. In addition, dyeing can also be performed after stretching. The PVA-based resin film is subjected to a swelling treatment, a crosslinking treatment, a washing treatment, a drying treatment, etc. as needed. For example, by immersing the PVA resin film in water and washing it before dyeing, not only can the dirt and anti-adhesive agent on the surface of the PVA resin film be washed away, but the PVA resin film can also be swollen to prevent uneven dyeing.

Specific examples of polarizing elements obtained using a laminate include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate. The polarizing element obtained by using a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate can be prepared, for example, by the following method: a PVA-based resin solution is coated on the resin substrate, and the laminate is dried to form a PVA-based resin layer on the resin substrate, thereby obtaining a laminate of the resin substrate and the PVA-based resin layer; the laminate is stretched and dyed to make the PVA-based resin layer a polarizing element. In this embodiment, stretching typically includes a step of immersing the laminate in a boric acid aqueous solution for stretching. Furthermore, the stretching may further include the step of stretching the laminate in the air at a high temperature (e.g., above 95°C) before stretching in a boric acid aqueous solution. The obtained laminate of the resin substrate/polarizing element can be used directly (i.e., the resin substrate can be used as a protective film for the polarizing element), or the resin substrate can be peeled off from the laminate of the resin substrate/polarizing element, and any appropriate protective film can be used on the peeled surface according to the target laminate. The details of the manufacturing method of such a polarizing element are described, for example, in the Japanese Patent Publication No. 2012-73580. The entire contents of the publication are cited in this specification by reference.

The polarizing element preferably exhibits absorption dichroism at any wavelength of 380nm~780nm. The single transmittance of the polarizing element is preferably 43.0%~46.0%, more preferably 44.5%~46.0%. The polarization degree of the polarizing element is preferably above 97.0%, more preferably above 99.0%, and further preferably above 99.9%.

The thickness of the polarizing element can be set to any appropriate value. The thickness is typically 0.5 μm to 80 μm, preferably 30 μm to 25 μm, more preferably 18 μm to 12 μm, and even more preferably less than 8 μm. The thickness of the polarizing element is preferably 1 μm or more.

B-1-2. Protective film

As the protective film, any appropriate resin film can be used. Examples of the material for forming the resin film include: (meth) acrylic resins; cellulose resins such as diacetyl cellulose and triacetyl cellulose; cycloolefin resins such as norbornene resins; olefin resins such as polypropylene; ester resins such as polyethylene terephthalate resins; polyamide resins; polycarbonate resins; copolymer resins thereof, etc. Furthermore, the so-called "(meth) acrylic resin" refers to acrylic resins and/or methacrylic resins.

The thickness of the protective film is typically 10μm~100μm, preferably 20μm~40μm. The protective film is typically laminated on the polarizing element via an adhesive layer (specifically, an adhesive layer, an adhesive layer). The adhesive layer is typically formed of a PVA adhesive or an active energy ray curing adhesive. The adhesive layer is typically formed of an acrylic adhesive. The acrylic adhesive may be the same as or different from the adhesive constituting the first adhesive layer or the second adhesive layer.

C. 1st adhesive layer

As the adhesive constituting the first adhesive layer, any appropriate adhesive having adhesiveness and transparency that can be used for optical purposes can be used. Specific examples include acrylic adhesives, rubber adhesives, silicone adhesives, polyester adhesives, urethane adhesives, epoxy adhesives, and polyether adhesives. The base resin of the adhesive may be used alone or in combination of two or more. From the viewpoints of transparency, processability, and durability, acrylic adhesives are preferred.

啉。丙烯酸系黏著劑組合物較佳為可含有矽 烷偶合劑及/或交聯劑。作為矽烷偶合劑，例如可例舉含有環氧基之矽烷偶合劑。作為交聯劑，例如可例舉異氰酸酯系交聯劑、過氧化物系交聯劑。此種黏著劑層或丙烯酸系黏著劑組合物之詳情例如記載於日本專利特開2014-115468號公報及日本專利第4140736號中，以參考之方式將該等公報之記載援引至本說明書中。 The acrylic adhesive composition typically contains a (meth)acrylic polymer as a main component (base polymer). The (meth)acrylic polymer can be contained in the adhesive composition in the following ratio, that is, in the solid content of the adhesive composition, for example, 50% by weight or more, preferably 70% by weight or more, and more preferably 90% by weight or more. The (meth)acrylic polymer contains an alkyl (meth)acrylate as a main component in the form of a monomer unit. Furthermore, (meth)acrylate refers to acrylate and/or methacrylate. As the alkyl group of the alkyl (meth)acrylate, for example, a straight chain or branched chain alkyl group having 1 to 18 carbon atoms can be cited. The average carbon number of the alkyl group is preferably 3 to 9. As monomers constituting the (meth)acrylic polymer, in addition to alkyl (meth)acrylates, there can be exemplified copolymerized monomers such as carboxyl-containing monomers, hydroxyl-containing monomers, amide-containing monomers, aromatic ring-containing (meth)acrylates, and heterocyclic (meth)acrylates. The copolymerized monomer is preferably a hydroxyl-containing monomer and/or a heterocyclic (meth)acrylate, and more preferably N-acryloyl

The acrylic adhesive composition preferably contains a silane coupling agent and/or a crosslinking agent. As the silane coupling agent, for example, a silane coupling agent containing an epoxy group can be exemplified. As the crosslinking agent, for example, an isocyanate crosslinking agent and a peroxide crosslinking agent can be exemplified. The details of such an adhesive layer or acrylic adhesive composition are described in, for example, Japanese Patent Publication No. 2014-115468 and Japanese Patent No. 4140736, and the descriptions of these publications are cited in this specification by reference.

The thickness of the first adhesive layer can be set to any appropriate value. The thickness of the first adhesive layer is preferably 20 μm or more, more preferably 40 μm or more, and further preferably 50 μm or more. In addition, the thickness of the first adhesive layer is preferably 500 μm or less, more preferably 350 μm or less, and further preferably 250 μm or less.

The storage modulus G' of the first adhesive layer at 25°C is preferably 1.0×10 ⁴ Pa to 1.0×10 ⁷ Pa, more preferably 3.0×10 ⁴ Pa to 7.0×10 ⁶ Pa, and further preferably 5.0×10 ⁴ Pa to 5.0×10 ⁶ Pa. By making the storage modulus G' at 25°C within this range, deformation of the adhesive layer can be prevented even when pressure is applied during bonding. Alternatively, through holes can be well formed in the optical laminate with the adhesive layer. Furthermore, in this specification, the storage modulus G' refers to the value measured according to the method described in JIS K 7244-1 "Plastics - Test methods for dynamic mechanical properties".

D. Second adhesive layer

As the adhesive constituting the second adhesive layer, the same adhesive as the adhesive constituting the first adhesive layer may be used, or an adhesive different therefrom may be used. When an adhesive different from the first adhesive layer is used, an adhesive commonly known in the industry may be used as the adhesive. Specifically, adhesives having a base polymer such as acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyvinyl ethers, vinyl acetate/vinyl chloride copolymers, modified polyolefins, epoxy-based, fluorine-based, natural rubber, synthetic rubber, and other rubber-based polymers may be cited.

The thickness of the second adhesive layer can be set to any appropriate value. Preferably, it is 3μm~500μm, more preferably, it is 5μm~350μm, further preferably, it is 10μm~250μm, and most preferably, it is 10μm~150μm.

The storage modulus G' of the second adhesive layer at 25°C is preferably 1.0×10 ⁴ Pa to 1.0×10 ⁷ Pa, more preferably 3.0×10 ⁴ Pa to 5.0×10 ⁶ Pa, and further preferably 5.0×10 ⁴ Pa to 1.0×10 ⁶ Pa. If the storage modulus G' of the second adhesive layer is within the above range, the optical laminate can be well bonded. Furthermore, through holes can be well formed in the optical laminate with the adhesive layer.

E. Other layers

The optical laminate with adhesive layer may further have any other appropriate layers other than the above-mentioned optical film, the first and second adhesive layers. Examples of other layers include the above-mentioned isolation film and optical functional film. The isolation film is used to properly protect the first adhesive layer and the second adhesive layer before use. The optical functional film is used to give the optical laminate with adhesive layer the desired optical function according to the purpose. Examples of optical functional films include protective films for polarizing elements or polarizing plates, anti-reflection films, anti-glare films, conductive films for touch panels, pressure-sensitive films, etc.

F. Method for manufacturing an optical laminate with an adhesive layer

The optical laminate with adhesive layer of the present invention can be manufactured by any appropriate method. The manufacturing method of the optical laminate with adhesive layer preferably includes the following steps: forming a first adhesive layer on one side of the optical film; forming a second adhesive layer on the other side of the optical film; and forming a through hole that integrally penetrates the first adhesive layer, the optical film and the second adhesive layer.

F-1. Formation of adhesive layer

The first adhesive layer and the second adhesive layer can be formed on the optical film by any appropriate method. For example, the adhesive layer can be formed by coating the adhesive forming the first adhesive layer or the adhesive forming the second adhesive layer on the optical film, or the adhesive layer can be formed by coating the adhesive on the isolation film or other resin film, and then the adhesive layer can be transferred to the optical film. In addition, the first adhesive layer and the second adhesive layer can be formed in any appropriate order.

In one embodiment, the through holes formed on the first adhesive layer and the second adhesive layer are larger than the through holes formed on the optical film. In this embodiment, for example, the adhesive layer can be formed in such a way that the end of the through hole formed on the adhesive layer and the end of the through hole formed on the optical film are at any appropriate distance.

As a coating method of the adhesive composition, any appropriate coating method can be used. For example, roller coating, contact roller coating, gravure coating, reverse coating, roller brush coating, spray coating, dip roller coating, rod coating, scraper coating, air knife coating, curtain coating, die lip coating, extrusion coating using a die nozzle coater, etc. can be cited.

F-2. Formation of through holes

Then, a through hole is formed on the optical film formed with the first adhesive layer and the second adhesive layer to penetrate the whole. When forming the through hole, in order to properly protect the adhesive layer, it is preferred to laminate an isolation film or a surface protection film on the first adhesive layer and the second adhesive layer.

Through holes can be formed by any appropriate method. For example, cutting using punching knives such as Thomson knives and pointed knives, rotating shafts, etc.; hole opening using cutting machines or lasers, etc. The processing conditions for forming through holes can be set to any appropriate conditions according to the through hole forming method used, the thickness of the first adhesive layer, the optical film, the second adhesive layer, and any isolation film or surface protection film, the type of optical film, etc.

In one embodiment, the through hole is formed by integrally penetrating the first adhesive layer, the optical film, and the second adhesive layer while the first adhesive layer and the second adhesive layer are laminated on the optical film. By forming the through hole while the first adhesive layer and the second adhesive layer are laminated with the optical film, deformation of the hole shape caused by tension and pressure when the layers are bonded and/or when the isolation film is peeled off can be suppressed.

F-3. Other steps

The manufacturing method of the optical laminate with adhesive layer of the present invention may include any other appropriate steps in addition to the above-mentioned steps of forming the adhesive layer and forming the through hole. For example, the following steps may be cited: peeling off the surface protection film used in the step of forming the through hole; and stacking an isolation film on the adhesive layer from which the surface protection film is peeled off.

G. Uses of optical laminates with adhesive layers

As described above, the optical multilayer with adhesive layer of the present invention can make the high-function image display device fully exert its various functions (such as the functions of cameras, speakers, and various sensors). Therefore, the optical multilayer of the present invention is suitable for image display devices. As image display devices, for example, liquid crystal display devices and organic EL (Electroluminescence) devices can be cited. Specifically, the liquid crystal display device has a liquid crystal panel, which includes a liquid crystal unit and the above-mentioned polarizing element arranged on one side or both sides of the liquid crystal unit. The organic EL device has an organic EL panel with the above-mentioned polarizing element arranged on the viewing side.

In an image display device, the optical multilayer with an adhesive layer of the present invention can be laminated on any appropriate adherend. For example, a glass plate, a liquid crystal unit, other optical multilayers, etc. are exemplified. The image display device is described in detail below.

G-1. Image display device

The image display device of the present invention includes: the optical laminate with an adhesive layer; a display panel disposed on one surface of the optical laminate with an adhesive layer and having a through hole at a portion corresponding to the through hole of the optical laminate with an adhesive layer; and a glass layer or a plastic layer disposed on the other surface of the optical laminate with an adhesive layer.

FIG2 is a schematic cross-sectional view of an image display device in one embodiment of the present invention. The image display device 200 shown in the figure includes an optical laminate 100 with an adhesive layer, and the optical laminate 100 with an adhesive layer has: an optical film 10; a first adhesive layer 20 formed on one side of the optical film 10; and a second adhesive layer 30 formed on the other side of the optical film 10. In the example shown in the figure, a glass layer or a plastic layer 140 is laminated on the first adhesive layer 20, and a display panel 150 is laminated on the second adhesive layer 30. The display panel 150 has a through hole at a position corresponding to the through hole formed on the optical laminate 100 with an adhesive layer. In the illustrated example, a glass layer or a plastic layer 140 is laminated on the first adhesive layer 20, and the display panel 150 having the through hole is laminated on the second adhesive layer 30, but the display panel 150 having the through hole may be laminated on the first adhesive layer 20, and the glass layer or the plastic layer 140 may be laminated on the second adhesive layer 30. As described above, the through holes of the optical laminate are formed in a manner that corresponds to the position, size, number and shape of the camera, speaker and various sensors mounted in the image display device. Not only does the optical laminate have through holes, but the display panel also has through holes corresponding to the through holes of the optical laminate, whereby the functions of the camera, speaker and various sensors can be fully utilized without being hindered by the optical laminate and the display panel. Typically, it can be configured as follows, that is, a glass layer or a plastic layer 140 is laminated on the first adhesive layer 20 of the optical laminate with an adhesive layer to form the viewing side of the image display device.

As described above, in one embodiment, the through hole is a through hole that penetrates the optical multilayer in a cone shape. In this embodiment, the size difference between the planar shape of the first through hole and/or the planar shape of the second through hole and the top view shape of the through hole formed on the display panel can be set to any appropriate value. The size difference between the planar shape of the first through hole and/or the planar shape of the second through hole and the top view shape of the through hole formed on the display panel is preferably 500 μm or less, more preferably 300 μm or less, and further preferably 100 μm or less. By making the size difference between the plane shape of the first through hole and/or the plane shape of the second through hole and the top view shape of the through hole formed on the display panel within the above range, the width of the black frame printing can be reduced, thereby improving the design. In addition, the size difference between the plane shape of the first through hole and the top view shape of the through hole formed on the display panel and the size difference between the plane shape of the second through hole and the top view shape of the through hole formed on the display panel can be the same or different as long as these two differences are within the above range.

The image display device 200 may further include any other appropriate components. For example, any other appropriate components may be included between the first adhesive layer and the second adhesive layer of the optical laminate 100 with an adhesive layer and the glass layer or plastic layer or the display panel with a through hole. As other components, for example, a phase difference layer, an anti-reflection layer, a protective layer, a conductive film for a touch panel, a pressure-sensitive film, etc. These other components may be bonded to the optical laminate 100 with an adhesive layer, the glass layer or plastic layer, or the display panel with a through hole via any appropriate adhesive layer or bonding agent layer.

G-2. Manufacturing method of image display device

The image display device of the present invention can be manufactured by any appropriate method. In one embodiment, the manufacturing method of the image display device of the present invention includes the following steps: forming a through hole in an optical film; forming a first adhesive layer on one side of the optical film; forming a through hole in the first adhesive layer; forming a second adhesive layer on the other side of the optical film; forming a through hole in the second adhesive layer; forming a through hole in a display panel; layering the display panel on one area of the optical film; and layering a glass layer or a plastic layer on another area of the optical film.

As described above, the optical film, the first adhesive layer, and the second adhesive layer included in the image display device have through holes. With regard to the through holes, the through holes may be formed in the optical film, the first adhesive layer, the second adhesive layer, and the display panel, respectively, and then the layers are laminated. Alternatively, the optical film, the first adhesive layer, the second adhesive layer, and the display panel may be laminated, and then the through holes may be formed in the laminated body (i.e., the through holes may be formed in the optical film, the first adhesive layer, the second adhesive layer, and the display panel at the same time). It is preferred to simultaneously perform the following steps: forming a through hole in the optical film; forming a through hole in the first adhesive layer; forming a through hole in the second adhesive layer; and forming a through hole in the display panel. As a method of simultaneously forming the through hole, for example, the through hole is formed in a state where the optical film, the first adhesive layer, the second adhesive layer, and the display panel are laminated.

In other embodiments, the image display device can also be manufactured by laminating the above-mentioned optical laminate and a display panel having a through hole corresponding to the through hole of the optical laminate. In this embodiment, the through hole is also formed in the adhesive layer formed between the optical laminate and the display panel. The step of forming the through hole in the adhesive layer can be performed at the same time as the step of forming the through hole in the display panel (in a state where the adhesive layer is laminated on the display panel), and the adhesive layer with a through hole formed separately can also be attached to the optical laminate or the display panel. The through holes formed on the adhesive layer are formed in positions and sizes corresponding to the through holes formed on the above-mentioned optical laminate and display panel.

The adhesive layer can be formed by any appropriate method. For example, it can be formed by the method described in F-1 above.

The through hole can be formed by any appropriate method. For example, it can be formed by the method described in F-2 above. When the through hole is formed by the adhesive layer, it is preferred to form the adhesive layer on any appropriate substrate and/or isolation film, and form the through hole in a state where the adhesive layer is sandwiched by the substrate and/or isolation film.

Implementation example

The present invention is described in detail below through examples, but the present invention is not limited to these examples. The evaluation items in the examples are as follows.

(1) Quality of through holes

The quality of the through holes of the display panels of each embodiment and comparative example was evaluated according to the following criteria. The status of the through holes was visually confirmed.

Best: The positions of holes between each layer are consistent, which can reduce the non-display area.

Good: The positions of the holes between the layers are somewhat deviated, and it can be practical by increasing the non-display area.

Unqualified: The hole position deviation is large and cannot be used.

(2) Suitability of the camera’s corresponding part

The image quality of the camera with the display panel of each embodiment and comparison example is evaluated according to the following criteria.

Good: Except for the outermost layer, all layers including the panel are provided with through holes to prevent light reflection on the interface, so the image quality is good and suitable for the camera counterpart.

Unqualified: There is a layer without through holes, and the light reflection on the interface causes the image quality to be damaged, which is not suitable for the corresponding part of the camera.

(3) Ease of production

The manufacturing steps of the display panels of each embodiment and comparative example are evaluated according to the following criteria.

Best: Fewer holes are drilled, and there is no need to align through holes during assembly.

Good: Fewer holes are drilled, but sometimes the through holes need to be aligned during bonding.

Unqualified: The number of hole openings is very large, and the number of times of lamination required to align the through holes is also large.

As the adhesive layer body A, a product named CS9866US manufactured by Nitto Denko Corporation was used (a product composed of a heavy-peel isolation film/adhesive layer A (thickness of 150 μm, storage modulus G' at 25°C of 0.14 MPa)/light-peel isolation film).

As the adhesive layer body B, a product named CS9864US manufactured by Nitto Denko Corporation was used (a product composed of a heavy-peel isolation film/adhesive layer B (thickness of 100 μm, storage modulus G' at 25°C of 0.14 MPa)/light-peel isolation film).

Manufacturing Example 1: Preparation of Adhesive Composition 1

Into a separable flask equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen inlet tube, 99 parts by weight of butyl acrylate (BA) as a monomer component, 1 part by weight of 4-hydroxybutyl acrylate (4HBA), 0.2 parts by weight of azobisisobutyronitrile as a polymerization initiator and ethyl acetate as a polymerization solvent were added in such a manner that the solid content was 20%. Then, nitrogen was introduced, and nitrogen replacement was performed for about 1 hour while stirring. Thereafter, the flask was heated to 60°C and reacted for 7 hours to obtain an acrylic polymer with a weight average molecular weight (Mw) of 1.1 million. To the above acrylic polymer solution (solid content: 100 parts by weight), 0.8 parts by weight of trihydroxymethylpropane toluene diisocyanate ("Coronate L" manufactured by Nippon Polyurethane Industry Co., Ltd.) as an isocyanate crosslinking agent and 0.1 parts by weight of a silane coupling agent ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.) were added to prepare an adhesive composition (solution).

Manufacturing Example 2: Preparation of Adhesive Layer C

The obtained adhesive solution was applied to a polyethylene terephthalate peeling pad having a thickness of 38 μm or 50 μm in such a manner that the thickness after drying became 20 μm, and then heated and dried at 60°C for 1 minute under normal pressure, and then heated and dried at 150°C for 1 minute to produce a laminate having an adhesive layer C (adhesive laminate). The adhesive laminate was used as adhesive laminate C.

<Production of polarizing elements>

A laminate having a polyvinyl alcohol (PVA) resin layer (thickness: 9μm) formed on an amorphous polyethylene terephthalate (PET) substrate was subjected to air-assisted stretching at a stretching temperature of 130°C to produce a stretched laminate. Then, the stretched laminate was dyed with iodine to obtain a colored laminate. Thereafter, the colored laminate was stretched in boric acid water at a stretching temperature of 65°C to a total stretching ratio of 5.94 times to produce a laminate having a 5μm thick PVA resin layer (polarizing element) stretched integrally with the amorphous PET substrate.

<Production of single-side protected polarizing plate>

On the surface of the polarizing element side of the laminate having the PVA resin layer, a polyvinyl alcohol adhesive is applied in such a way that the adhesive layer has a thickness of 0.1 μm, and a transparent protective film (obtained by corona treatment of a (meth) acrylic resin film having a lactone ring structure with a thickness of 20 μm (film b-1)) is attached, and dried at 50°C for 5 minutes. Then, the amorphous PET substrate is peeled off to prepare a single-sided protective polarizing plate.

<Implementation Example 1>

The adhesive layer C is bonded to the polarizing element of the single-sided protective polarizing plate through the adhesive layer C. Then, a separator film is peeled off from the adhesive layer A, and the peeled surface is bonded to the protective layer of the single-sided protective layer polarizing plate. A through hole (circular, 5 mm in diameter) is formed in the obtained optical laminate with adhesive layer, and an optical laminate with adhesive layer and separator film is obtained.

Similarly, a through hole (circular, with a diameter of 5 mm) is formed in the display panel (organic EL (OLED (Organic Light-Emitting Diode)) panel) at a position corresponding to the through hole of the optical laminate with the adhesive layer.

The adhesive layer A of the optical laminate with an adhesive layer attached to the isolation film is peeled off, and a cover glass (thickness of 0.5 mm) is attached. Furthermore, the adhesive layer C is peeled off from the isolation film, and a display panel with a through hole is attached in a manner that the position of the through hole of the display panel corresponds to the through hole of the optical laminate with the adhesive layer, thereby obtaining an image display device 1.

<Implementation Example 2>

A through hole (circular, 5mm in diameter) is formed in the adhesive layer A.

The adhesive layer C is bonded to the polarizing element of the single-sided protective polarizing plate through the adhesive layer C. Then, the peel-off pad is peeled off and the display panel (OLED panel) is bonded through the adhesive layer C. Then, a through hole (circular, 5 mm in diameter) is formed at a position corresponding to the through hole formed on the above-mentioned adhesive layer A, and a display panel with an optical layer having a through hole is obtained.

Afterwards, a spacer film is peeled off from the adhesive layer A and a cover glass (thickness of 0.5 mm) is bonded. Then, another spacer film of the adhesive layer A is peeled off, and the through hole of the adhesive layer A is aligned and bonded with the through hole of the display panel with the optical laminate, thereby obtaining an image display device 2.

<Implementation Example 3>

Adhesive layer A from which a spacer film has been peeled off is laminated on an optical film (manufactured by Japan Zeon Co., Ltd., product name: ZF14-050) via adhesive layer A. Then, adhesive layer B from which a spacer film has been peeled off is laminated on the other side of the optical film via adhesive layer B to form an optical film laminate. A through hole (circular, 5 mm in diameter) is formed in the obtained optical film laminate to obtain an optical film laminate having a through hole.

In addition, after the adhesive layer C is laminated on the polarizing element of the single-side protective polarizing plate by adhesive C, the isolation film is peeled off and the display panel (OLED panel) is attached to obtain a display panel with an optical laminate. Then, a through hole (circular, with a diameter of 5 mm) is formed at a position of the display panel with an optical laminate corresponding to the through hole of the optical film laminate with a through hole formed thereon, and a display panel with an optical laminate with a through hole formed thereon is obtained.

The isolation film is peeled off from the adhesive layer A of the optical film laminate having through holes, and a cover glass (thickness of 0.5 mm) is attached. Then, the isolation film is peeled off from the adhesive layer laminate B, and the display panel with the optical laminate having through holes is attached to the polarizing element of the optical film laminate having through holes in a manner that the through holes are aligned with each other, thereby obtaining an image display device 3.

<Implementation Example 4>

An adhesive layer A with a separator film peeled off is attached to one side of an optical film (manufactured by Japan Zeon Co., Ltd., product name: ZF14-050), and an adhesive layer B with a separator film peeled off is attached to the other side to obtain an optical film with an adhesive layer.

In addition, after the adhesive layer C is laminated on the polarizing element of the single-side protective polarizing plate by adhesive C, the isolation film is peeled off and the display panel (OLED panel) is attached to obtain a display panel with an optical laminate.

The isolation film is peeled off from the adhesive layer B of the optical film having the adhesive layer, and is bonded to the polarizing element of the display panel with the optical laminate through the adhesive layer B. Then, a through hole (circular, with a diameter of 5 mm) is formed at a specific position of the laminate obtained by bonding. Then, the isolation film is peeled off from the adhesive layer A, and a cover glass (thickness of 0.5 mm) is bonded, thereby obtaining an image display device 4.

<Implementation Example 5>

The adhesive layer C is bonded to the polarizing element of the single-side protective polarizing plate through the adhesive layer C to obtain a polarizing plate with an adhesive layer.

Then, through holes (circular, with a diameter of 5 mm) are formed at specific locations of the above-mentioned polarizing plate with adhesive layer, adhesive layer A, adhesive layer B, touch screen panel (TSP) and display panel (OLED panel).

Afterwards, the layers with through holes and the cover glass (thickness of 0.5 mm) are stacked in the order of cover glass/adhesive layer A/TSP/adhesive layer B/protective layer/polarizing element/adhesive layer C/display panel to obtain the image display device 5. Furthermore, the layers with through holes are bonded in a manner that the positions of the through holes correspond to each other.

<Implementation Example 6>

The configuration of the image display device is set to cover glass/adhesive layer A/protective layer/polarizing element/adhesive layer C/TSP/adhesive layer B/display panel. Otherwise, the image display device 6 is obtained in the same manner as in Example 3.

<Implementation Example 7>

The above-mentioned adhesive layer body C is bonded to the polarizing element of the single-sided protective polarizing plate through the adhesive layer C to obtain a polarizing plate with an adhesive layer. Then, a spacer film is peeled off from the above-mentioned adhesive layer body A, and the peeled surface is bonded to the protective layer of the single-sided protective layer polarizing plate. Thereafter, the spacer film is peeled off from the adhesive layer C, and a display panel (OLED panel) is bonded to form a through hole (circular, with a diameter of 5 mm) at a specific position. Thereafter, the spacer film is peeled off, and a glass (thickness of 0.5 mm) is covered through the adhesive layer A layer to obtain an image display device 7.

<Implementation Example 8>

The adhesive layer body C is bonded to the polarizing element of the single-side protective polarizing plate through the adhesive layer C, thereby obtaining the polarizing plate with the adhesive layer attached. Then, the separator film is peeled off from the adhesive layer C, and the polarizing element is bonded to the display panel (OLED panel) through the adhesive layer C. Next, adhesive layer B, TSP, and adhesive layer A are sequentially stacked on the protective layer side of the polarizing plate with an adhesive layer, and a laminate having adhesive layer A/TSP/adhesive layer B/protective layer/polarizing element/adhesive layer C/display panel is obtained. A through hole (circular, 5 mm in diameter) is formed at a specific position of the laminate. Thereafter, the isolation film is peeled off from the laminate having the through hole, and the laminate is covered with glass (0.5 mm thick) via the adhesive layer a to obtain an image display device 8.

(Comparison Example 1)

Form a through hole (circular, 5mm in diameter) in the display panel (OLED panel).

In addition, the above-mentioned adhesive layer body C is bonded to the polarizing element of the single-side protective polarizing plate through the adhesive layer C to obtain a polarizing plate with an adhesive layer. The isolation film is peeled off from the adhesive layer C of the polarizing plate with an adhesive layer, and bonded to the display panel formed with a through hole. Then, the adhesive layer body A is bonded to the protective layer of the polarizing plate with an adhesive layer, and the glass (thickness is 0.5 mm) is laminated through the adhesive layer A to obtain an image display device C1.

(Comparison Example 2)

Form a through hole (circular, 5mm in diameter) in the display panel (OLED panel).

Furthermore, the adhesive layer body C is bonded to a polarizing element of a single-side protective polarizing plate via an adhesive layer C, thereby obtaining a polarizing plate with an adhesive layer. The separator film is peeled off from the adhesive layer C of the polarizing plate with an adhesive layer, and bonded to a display panel having a through hole formed therein. Then, the adhesive layer body B is bonded to the protective layer of the polarizing plate with an adhesive layer, and TSP is laminated via the adhesive layer B. Afterwards, an adhesive layer A is deposited on the TSP, and a glass layer (thickness of 0.5 mm) is covered via the adhesive layer A to obtain an image display device C2.

<Implementation Examples 9~11> (Comparative Example 3)

A through hole (circular, 5 mm in diameter) was formed at a specific position of the above-mentioned single-sided protected polarizing plate. Then, through holes were formed on the adhesive layer A and the adhesive layer C respectively in such a manner that the distance from the end of the through hole formed on the single-sided protected polarizing plate became the value recorded in Table 2. Next, a spacer film is peeled off from the adhesive layer A and the adhesive layer C, and the optical laminate (spacer film/adhesive layer A/protective layer/polarizing element/adhesive layer C/spacer film) is obtained by laminating them in such a way that the center of the through hole formed on the adhesive layer is consistent with the center of the through hole formed on the polarizing plate. The through hole of the obtained optical laminate is visually confirmed from the side of the adhesive layer A to evaluate whether the adhesive layer protrudes.

<Implementation Example 12>

A separator film was peeled off from the adhesive layer B, and the adhesive layer B was laminated on the protective layer side of the above-mentioned single-sided protected polarizing plate. The adhesive layer D was obtained in the same manner as in Production Example 2 except that the coating was performed in such a manner that the thickness after drying became 25 μm. A separator film was peeled off from the obtained adhesive layer D, and the adhesive layer D was laminated on the polarizing element of the above-mentioned single-sided protected polarizing plate. A through hole (circular, 5 mm in diameter) is formed at a specific position of the obtained laminate of isolation film/adhesive layer B/protective layer/polarizing element/adhesive layer D/isolation film to obtain an optical laminate.

<Implementation Example 13>

Adhesive layer A was used instead of adhesive layer B, and a phase difference film (thickness of 50 μm) was used instead of a single-sided protective polarizing plate, and the coating was performed in such a way that the thickness after drying became 100 μm. Adhesive layer E was prepared in the same manner as in Example 2, and the optical layer was prepared in the same manner as in Example 12 except that the adhesive layer E was used.

<Implementation Example 14>

A transparent film (thickness of 50 μm) was used instead of the single-sided protective polarizing plate, and the coating was performed in such a way that the thickness after drying became 50 μm. In addition, an adhesive layer F was prepared in the same manner as in Example 2, and an optical layer was prepared in the same manner as in Example 12 using the adhesive layer F.

(Comparison Example 4)

A through hole (circular, diameter: 5 mm) is formed at a specific position of the adhesive layer B to obtain a laminate.

The following evaluation was performed using the multilayer bodies with through holes obtained in Examples 12 to 14 and Comparative Example 4.

After processing the diameter of the through hole of the laminate obtained in Examples 12 to 14 and Comparative Example 4, a piece of isolation film was peeled off and then immediately attached to the panel. The profile was then measured and calculated using the following formula based on the obtained values. In addition, regarding the diameter of the through hole, the value of the part with the largest diameter value was taken as the diameter of the through hole. The results are shown in Table 3.

Profile = designed through hole diameter / measured through hole diameter

<Implementation Examples 15~17> (Comparative Examples 5~6)

A separator is peeled off from the adhesive layer A, and the adhesive layer A is laminated on the protective layer of the single-sided protective polarizing plate. Then, a separator is peeled off from the adhesive layer C, and the adhesive layer C is laminated on the polarizing element of the single-sided protective polarizing plate to obtain an optical laminate. The diameter of the through hole on the outermost surface of the adhesive layer A (the surface on the isolation film side) is set to Φ1, and the diameter of the through hole on the outermost surface of the adhesive layer C (the surface on the isolation film side) is set to Φ2. A tapered through hole is formed in such a way that Φ1 and Φ2 become the values listed in Table 4, and an optical multilayer body having a through hole is obtained.

In addition, a black frame having the outer diameter, inner diameter and width shown in Table 4 is printed on the panel. Then, the isolation film of the adhesive layer C is peeled off, and the optical laminate is laminated with the panel in such a way that the center of the through hole is aligned with the center of the black frame printed on the panel.

The following evaluations were performed on the laminates of Examples 15 to 17 and Comparative Examples 5 to 6.

(Appearance)

Visually confirm the through-holes of the obtained laminate from the visual side (adhesive layer A side) and evaluate whether the cut surface of the hole and the cut surface of the display area can be seen.

(Wide angle)

The camera module is aligned with the through hole on the panel side of the obtained laminate, and the degree of wide angle is evaluated according to the following criteria based on the image taken.

Best: The shooting area is wider, and the cut surface of the through hole does not enter the shooting area at all, which does not hinder image shooting.

Good: The shooting area is slightly narrowed, but the cut surface of the through hole does not enter the shooting area, which does not hinder image shooting.

Pass: The shooting area becomes narrower, but the cut surface of the through hole does not enter the shooting area, and does not hinder image shooting.

Unqualified: The shooting area is narrow, and the cutting surface of the through hole is included in the shooting area.

(Design)

Evaluate the design of through holes according to the following criteria.

Best: No black frame can be seen on the through hole.

Good: Some black frames can be seen through the through hole.

Pass: The black frame can be seen through the through hole, but it does not hinder the design.

Unqualified: The black frame can be clearly seen from the through hole, and the size of the corresponding part of the camera is smaller than the designed size of the through hole.

[Table 4]

<Implementation Examples 18~20> (Comparative Example 7)

A separator is peeled off from the adhesive layer A, and the adhesive layer A is laminated on the protective layer of the single-sided protective polarizing plate. Then, a separator is peeled off from the adhesive layer C, and the adhesive layer C is laminated on the polarizing element of the single-sided protective polarizing plate to obtain an optical laminate. The diameter of the through hole on the outermost surface of the adhesive layer A (the surface on the isolation film side) is set to Φ1, and the diameter of the through hole on the outermost surface of the adhesive layer C (the surface on the isolation film side) is set to Φ2. A tapered through hole is formed in such a way that Φ1 and Φ2 become the values listed in Table 4, and an optical multilayer body having a through hole is obtained.

In addition, a black frame having the outer diameter, inner diameter and width shown in Table 5 is printed on the panel. Then, the isolation film of the adhesive layer C is peeled off, and the optical laminate is laminated with the panel in such a way that the center of the through hole is aligned with the center of the black frame printed on the panel.

The following evaluations were performed on the laminates of Examples 18 to 20 and Comparative Example 7.

(put one's oar in)

The camera module is aligned with the through hole on the panel side of the obtained laminate, and the camera module is evaluated according to the following criteria to see whether it interferes with the through hole. The results are shown in Table 5.

Best: The camera module does not contact the through hole, which can shorten the distance between the camera module and the visual side surface of the optical multilayer.

Good: Although the camera module is in contact with the through hole, the shooting function is not affected, and the distance between the camera module and the visual side surface of the optical multilayer can be shortened.

<Implementation Examples 21~23> (Comparative Example 8)

A separator is peeled off from the adhesive layer A, and the adhesive layer A is laminated on the protective layer of the single-sided protective polarizing plate. Then, a separator is peeled off from the adhesive layer C, and the adhesive layer C is laminated on the polarizing element of the single-sided protective polarizing plate to obtain an optical laminate. The diameter of the through hole on the outermost surface of the adhesive layer A (the surface on the isolation film side) is set to Φ1, and the diameter of the through hole on the outermost surface of the adhesive layer C (the surface on the isolation film side) is set to Φ2. A tapered through hole is formed in such a way that Φ1 and Φ2 become the values listed in Table 6, and an optical multilayer body having a through hole is obtained.

In addition, a black frame having the outer diameter, inner diameter and width listed in Table 6 is printed on the panel. Then, the isolation film of the adhesive layer C is peeled off, and the optical laminate is laminated with the panel in such a way that the center of the through hole is aligned with the center of the black frame printed on the panel.

The following evaluations were performed on the laminates of Examples 21 to 23 and Comparative Example 8. The results are shown in Table 6.

(End appearance)

Visually confirm the through hole from the viewing side and evaluate whether the end of the through hole cut surface can be seen from the through hole. All the examples and comparative examples have no visible end, which is the best result.

(Black frame width)

Evaluate the extent to which the opening of the through hole is affected by the black frame based on the following criteria.

Best: The end of the black frame cannot be seen through the through hole, which does not hinder the wide-angle of the camera.

Good: Although the end of the black frame can be seen through the through hole, it does not hinder the wide-angle of the camera.

Pass: Although the width of the black frame can be seen through the through hole, it does not hinder the wide-angle function of the camera.

Unqualified: A black frame can be seen from the opening of the through hole, and the camera cannot achieve wide-angle viewing.

[Industrial availability]

The optical multilayer body of the present invention is suitable for image display devices such as liquid crystal display devices and organic EL devices.

10: Optical film

20: 1st adhesive layer

30: Second adhesive layer

40: Isolation film

50:Through hole

100: Optical laminate with adhesive layer attached

Claims (7)

An optical laminate with an adhesive layer, comprising: an optical film; a first adhesive layer formed on one surface of the optical film; and a second adhesive layer formed on the other surface of the optical film; and having a through hole that integrally penetrates the first adhesive layer, the optical film, and the second adhesive layer, wherein the through hole formed in the first adhesive layer and the second adhesive layer has a larger size in top view than the through hole formed in the optical film. An optical laminate with an adhesive layer as claimed in claim 1, wherein the optical film is at least one selected from the group consisting of a polarizing plate, a phase difference film, a conductive film for a touch panel, a pressure-sensitive film, and a transparent plastic film. A method for manufacturing an optical laminate with an adhesive layer, comprising the following steps: forming a first adhesive layer on one side of an optical film; forming a second adhesive layer on the other side of the optical film; and forming a through hole that penetrates the first adhesive layer, the optical film, and the second adhesive layer; and the through hole formed in the first adhesive layer and the second adhesive layer has a top view that is larger than the through hole formed in the optical film. An image display device, comprising: an optical laminate with an adhesive layer as claimed in claim 1 or 2; a display panel disposed on one surface of the optical laminate with an adhesive layer and having a through hole at a portion corresponding to the through hole of the optical laminate with an adhesive layer; and a glass layer or a plastic layer disposed on the other surface of the optical laminate with an adhesive layer. As in claim 4, the through hole of the optical laminate with the adhesive layer and the through hole of the display panel are through holes that connect the optical laminate and the display panel as a whole. A method for manufacturing an image display device includes the following steps: forming a through hole in an optical film; forming a first adhesive layer on one side of the optical film; forming a through hole in the first adhesive layer; forming a second adhesive layer on the other side of the optical film; forming a through hole in the second adhesive layer; forming a through hole in a display panel; layering the display panel on one area of the optical film; and layering a glass layer or a plastic layer on another area of the optical film; and the through hole formed in the first adhesive layer and the second adhesive layer has a top view shape that is larger than the through hole formed in the optical film. The manufacturing method of claim 6, wherein the following steps are performed simultaneously: forming a through hole in the optical film; forming a through hole in the first adhesive layer; forming a through hole in the second adhesive layer; and forming a through hole in the display panel.