JP2021161264A - Optical laminate - Google Patents

Abstract

To provide an optical laminate appropriate for manufacturing a self-luminous type display device such as a mini/micro LED display device with improved antireflection function of metal wiring and contrast, while enhancing luminous efficiency.SOLUTION: An optical laminate 10 includes a laminate structure with a first adhesive layer 1, a first substrate S, and a second adhesive layer 2 laminated in this order. Visible light transmittance T1 of the first adhesive layer 1 and visible light transmittance T2 of the second adhesive layer 2 satisfy T1<T2. Visible light transmittance T1 of the first adhesive layer 1 and visible light transmittance TS of the first substrate S preferably satisfy T1<TS.SELECTED DRAWING: Figure 1

Description

The present invention relates to an optical laminate suitable for sealing a light emitting element of a self-luminous display device such as a mini / micro LED.

In recent years, as a next-generation display device, a self-luminous display device represented by a mini / micro LED display device (Mini / Micro Light Emitting Diode Display) has been devised. As a basic configuration of a mini / micro LED display device, a substrate in which a large number of minute LED light emitting elements (LED chips) are arranged at high density is used as a display panel, and the LED chips are sealed with a sealing material. A cover member such as a resin film or a glass plate is laminated on the outermost layer.

There are several self-luminous display devices such as mini / micro LED display devices, such as a white backlight system, a white emission color filter system, and an RGB system. In the white emission color filter system and the RGB system, the display panel is used. A black encapsulant may be used to prevent reflection of metal wiring or metal oxides such as ITO arranged on the substrate (see, for example, Patent Documents 1 to 3). Above all, in the RGB type mini / micro LED display device in which the LED chips are arranged, the black encapsulant can contribute to the prevention of RGB color mixing and the improvement of contrast.

JP-A-2019-204905 JP-A-2017-203810 Special Table 2018-523854

When the black encapsulant is used, the upper part (image display side) of the light emitting element such as an LED chip is covered with the black encapsulant having a reduced transmittance for visible light, so that the luminous efficiency is reduced and the image becomes dark. There is a problem of becoming. In order to deal with this, when the output of the LED chip is increased to increase the emission brightness, there is also a problem that the power consumption is increased.

When the transmittance of the black encapsulant to visible light is increased in order to increase the luminous efficiency, there is a trade-off relationship between the above-mentioned antireflection function such as metal wiring, RGB color mixing prevention, and a decrease in contrast. Making them compatible was a difficult problem to solve.

On the other hand, as the black encapsulant, a liquid curable resin containing a black colorant (dye or pigment) or a pressure-sensitive adhesive is used. When a liquid curable resin containing a black colorant is used, there is a problem that the blackness becomes uneven due to the uneven thickness.

The present invention has been conceived under the above circumstances, and an object of the present invention is a mini / micro LED having improved antireflection function such as metal wiring and contrast while improving luminous efficiency. It is an object of the present invention to provide an optical laminate suitable for manufacturing a self-luminous display device such as a display device.

As a result of diligent studies to achieve the above object, the present inventors use an optical laminate in which two pressure-sensitive adhesive layers having different transmittances are laminated via a base material for manufacturing a self-luminous display device. As a result, it has been found that it is possible to manufacture a self-luminous display device that has both an improvement in luminous efficiency, an antireflection function such as metal wiring, and an improvement in contrast. The present invention has been completed based on these findings.

That is, the first aspect of the present invention has a laminated structure in which the first pressure-sensitive adhesive layer, the base material, and the second pressure-sensitive adhesive layer are laminated in this order, and the first pressure-sensitive adhesive layer is visible. The light transmittance T _{1 and the visible light transmittance T 2} of the second pressure-sensitive adhesive layer provide an optical laminate satisfying _{T 1} <T _2.

In the optical laminate of the first aspect of the present invention, the visible light transmittance of the first pressure-sensitive adhesive layer T _1, and the visible light transmittance T ₂ of the second pressure-sensitive adhesive layer, satisfy T ₁ <T ₂ That is, the configuration in which the visible light transmittance of the first pressure-sensitive adhesive layer is lower than the visible light transmittance of the second pressure-sensitive adhesive layer makes the optical laminate on the first side surface of the present invention self-luminous. By using it in the manufacture of a display device, the first pressure-sensitive adhesive layer is preferable in preventing reflection due to metal wiring or the like on the display panel, preventing color mixing between arranged light emitting elements, and improving contrast. Further, in the configuration, the second pressure-sensitive adhesive layer showing a higher visible light transmittance than the first pressure-sensitive adhesive layer is located above the light emitting element (image display side), and the luminous efficiency is improved. This is preferable in that the image can be brightened and the power consumption due to the increase in output for increasing the luminous brightness can be reduced.
That is, the optical laminate on the first side surface of the present invention is provided with the above configuration to improve the luminous efficiency, and also has an antireflection function for metal wiring and the like, which has a trade-off relationship with the optical laminate, and RGB color mixing. It also solves the problems of prevention and improvement of contrast.

In the optical laminate of the first aspect of the present invention, the visible light transmittance T _S of the visible light transmittance T _1, and the base of the first pressure-sensitive adhesive layer preferably satisfy T ₁ <T _S .. In this configuration, the base material exhibiting a higher visible light transmittance than the first pressure-sensitive adhesive layer is located above the light emitting element (image display side), and the luminous efficiency is improved to brighten the image. It is preferable in that it can reduce the power consumption due to the increase in output for increasing the luminous brightness.

In the optical laminate of the first side surface of the present invention, the visible light transmittance T ₁ of the first pressure-sensitive adhesive layer is preferably 80% or less. This configuration is preferable in that it has an antireflection function such as the above-mentioned metal wiring, RGB color mixing prevention, and further improvement of contrast. _{The visible light transmittance T 2} of the second pressure-sensitive adhesive layer is preferably 85 to 100%. This configuration is preferable in that the above-mentioned luminous efficiency is further improved. That is, the visible light transmittance T ₁ of the first pressure-sensitive adhesive layer is 80% or less, and the visible light transmittance T ₂ of the second pressure-sensitive adhesive layer is 85 to 100%, which means that the luminous efficiency is improved. It is extremely suitable for making it possible to achieve both the antireflection function of metal wiring and the like, the prevention of RGB color mixing, and the improvement of contrast, which are in a trade-off relationship with the improvement.

In the optical laminate of the first side surface of the present invention, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer have a pressure-sensitive adhesive composition selected from a photocurable pressure-sensitive adhesive composition and a solvent-type pressure-sensitive adhesive composition. It is preferably an adhesive layer formed from an object. The pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer preferably contains a colorant. These configurations are such that the T ₁ and the T ₂ satisfy T ₁ <T ₂ , and the above-mentioned luminous efficiency, antireflection function such as metal wiring, RGB color mixing prevention, and contrast are further improved. , Suitable.

Further, when the pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer contains a colorant, the configuration in which the base material is laminated between the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer is not applicable. The colorant (particularly the dye) contained in the first pressure-sensitive adhesive layer moves to the second pressure-sensitive adhesive layer, the visible light transmittance of the second pressure-sensitive adhesive layer is lowered, and the above-mentioned light emission efficiency is lowered. It is preferable to prevent the above.

In the optical laminate of the first side surface of the present invention, the pressure-sensitive adhesive composition preferably contains an acrylic polymer. The acrylic polymer preferably contains a (meth) acrylic block copolymer. The pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer is preferably a solvent-type pressure-sensitive adhesive composition containing a (meth) acrylic block copolymer. In these configurations, when the optical laminate on the first side surface of the present invention is used for manufacturing a self-luminous display device, the first pressure-sensitive adhesive layer has a gap between steps of light emitting elements arranged on the display panel. It is preferable because it is filled without any problem, has excellent step absorption, and is also excellent in workability.

In the optical laminate of the first side surface of the present invention, the thickness of the first pressure-sensitive adhesive layer is preferably 10 to 300 μm, more preferably 15 to 200 μm. The thickness of the second pressure-sensitive adhesive layer is preferably 1 to 500 μm, more preferably 10 to 300 μm, and even more preferably 15 to 200 μm. The ratio of the thickness of the second pressure-sensitive adhesive layer to the thickness of the first pressure-sensitive adhesive layer (thickness of the second pressure-sensitive adhesive layer / thickness of the first pressure-sensitive adhesive layer) is preferably 1.0 to 5.0. , 1.2 to 4.0, more preferably 1.3 to 3.0. In these configurations, the first adhesive layer sufficiently seals between the light emitting elements arranged on the display panel of the self-luminous display device to prevent reflection of metal wiring and prevent RGB color mixing. It is preferable that the contrast is improved and the luminous efficiency can be improved by covering the upper part (image display side) of the light emitting element with the second pressure-sensitive adhesive layer having high transparency.

It is preferable that the second base material is further laminated on the surface of the second pressure-sensitive adhesive layer on which the base material is not laminated. With this configuration, the first pressure-sensitive adhesive layer serves as a sealing material for sealing the light emitting elements arranged on the display panel, and the second base material serves as a cover member for the outermost layer, and thus is separately covered after sealing. It is not necessary to stack the members, the number of processes and the required members can be reduced, and the manufacturing efficiency is improved.

In the optical laminate of the first side surface of the present invention, it is preferable that the surface of the second base material on which the second pressure-sensitive adhesive layer is not laminated is subjected to antireflection treatment and / or antiglare treatment. The antireflection treatment and / or antiglare treatment is preferably an antiglare layer provided on one side of the second base material. The anti-glare layer is formed by using an anti-glare layer forming material containing a resin, particles and a thixotropy-imparting agent, and the anti-glare layer is formed on the surface of the anti-glare layer by aggregating the particles and the thixotropy-imparting agent. It is preferable to have an agglomerated portion that forms a convex portion. In the convex portion on the surface of the anti-glare layer, the average inclination angle θa (°) is preferably in the range of 0.1 to 5.0. These configurations impart an antireflection function and / or an antiglare function to the surface of the optical laminate on the first side surface of the present invention, and prevent deterioration of visibility due to reflection of external light, reflection of an image, or the like. It is preferable from the viewpoint of adjusting the appearance such as glossiness.

In the optical laminate on the first side surface of the present invention, a surface protective film may be further laminated on the surface of the second base material on which the second pressure-sensitive adhesive layer is not laminated. Such a configuration is suitable for preventing the adhesion of scratches and stains during the manufacture, transportation, and shipment of the optical laminate and the optical products containing the same.

The second side surface of the present invention is a self-luminous display device including a display panel in which a plurality of light emitting elements are arranged on one side of a substrate and an optical laminate of the first side surface of the present invention. Provided is a self-luminous display device in which a surface on which light emitting elements of a display panel are arranged and a first pressure-sensitive adhesive layer of the optical laminate are laminated. In the self-luminous display device on the second side surface of the present invention, the display panel may be an LED panel in which a plurality of LED chips are arranged on one side of a substrate. Such a configuration is preferable in that the self-luminous display device on the second side of the present invention can improve the luminous efficiency, prevent reflection of metal wiring on the substrate, prevent RGB color mixing, and improve contrast.

By using the optical laminate of the present invention for manufacturing a self-luminous display device, it is possible to efficiently manufacture a self-luminous display device having improved luminous efficiency, antireflection function such as metal wiring, and contrast.

FIG. 1 is a schematic view (cross-sectional view) showing an embodiment of the optical laminate of the present invention. FIG. 2 is a schematic view (cross-sectional view) showing another embodiment of the optical laminate of the present invention. FIG. 3 is a schematic view (cross-sectional view) showing another embodiment of the optical laminate of the present invention. FIG. 4 is a schematic view (cross-sectional view) showing another embodiment of the optical laminate of the present invention. FIG. 5 is a schematic view (cross-sectional view) showing an embodiment of the self-luminous display device (mini / micro LED display device) of the present invention. FIG. 6 is a schematic view (cross-sectional view) showing another embodiment of the self-luminous display device (mini / micro LED display device) of the present invention. FIG. 7 is a schematic view (cross-sectional view) showing another embodiment of the self-luminous display device (mini / micro LED display device) of the present invention.

The first aspect of the present invention provides an optical laminate. The optical laminate on the first side surface of the present invention includes a first pressure-sensitive adhesive layer, a base material (sometimes referred to as a "first base material" in the present specification), and a second pressure-sensitive adhesive layer. , It has a laminated structure in which it is laminated in this order. The visible light transmittance of the first pressure-sensitive adhesive layer T _1, and the visible light transmittance T ₂ of the second pressure-sensitive adhesive layer is to satisfy T ₁ <T _2.

"Optical" in the optical laminate on the first side surface of the present invention means that it is used for optical purposes, and more specifically, it is used for manufacturing a product (optical product) using an optical member or the like. Means to be. Examples of optical products include an image display device, an input device such as a touch panel, and a self-luminous display device such as a mini / micro LED display device and an organic EL (electroluminescence) display device is preferable, and a mini is particularly preferable. / Can be suitably used for manufacturing a micro LED display device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited thereto and is merely an example.

1 to 4 are schematic views (cross-sectional views) showing an embodiment of the optical laminate of the first side surface of the present invention. 5 to 7 are schematic views (cross-sectional views) showing an embodiment of a self-luminous display device (mini / micro LED display device) on the second side surface of the present invention.

In FIG. 1, the optical laminated body 10 has a laminated structure in which a first pressure-sensitive adhesive layer 1, a first base material S, and a second pressure-sensitive adhesive layer 2 are laminated in this order.
In this embodiment, the visible light transmittance of the first adhesive layer 1 T _1, and the visible light transmittance T ₂ of the second pressure-sensitive adhesive layer 2, satisfy T ₁ <T _2. That is, the visible light transmittance of the first pressure-sensitive adhesive layer 1 is lower than the visible light transmittance of the second pressure-sensitive adhesive layer 2.

In the optical laminate 10 of the present embodiment, the first base material S is laminated between the first pressure-sensitive adhesive layer 1 and the second pressure-sensitive adhesive layer 2. With this configuration, the first base material S physically separates the first pressure-sensitive adhesive layer 1 and the second pressure-sensitive adhesive layer 2, and for example, the first pressure-sensitive adhesive layer 1 is a colorant (particularly a dye) as described later. When the above is contained, it is possible to prevent the colorant from migrating to the second pressure-sensitive adhesive layer 2 and lowering the transmittance.

In this embodiment, the visible light transmittance T _S of the first visible light transmittance T ₁ of the adhesive layer 1, and the first substrate S is preferably satisfy T ₁ <T _S. That is, the visible light transmittance of the first base material S is preferably higher than the visible light transmittance of the first pressure-sensitive adhesive layer 2. Since the visible light transmittance of the first base material S is higher than the visible light transmittance of the first pressure-sensitive adhesive layer 1, it has sufficient transparency in the visible light region. Since the first base material S having higher transparency is located on the upper part (display image side) of each LED chip 7, the absorption of visible light emitted from each LED chip 7 is suppressed to a low level, and the luminous efficiency is high. Therefore, the image can be made brighter.

In FIG. 2, in the optical laminated body 20, the second base material 3 is further laminated on the surface 2a on which the first base material S of the second adhesive layer 2 of the optical laminated body 10 is not laminated. In FIG. 3, in the optical laminate 21, the surface 3a of the optical laminate 20 on which the second adhesive layer 2 of the second base material 3 is not laminated is subjected to antireflection treatment and / or antiglare treatment 4. .. In FIG. 4, in the optical laminate 22, an anti-glare layer 4a is formed on the surface 3a of the optical laminate 20 as an antireflection treatment and / or an anti-glare treatment.

In FIG. 5, the self-luminous display device (mini / micro LED display device) 30 includes a display panel in which a plurality of LEDs 7 are arranged on one side of a substrate 5, and an optical laminate 20 according to the first side surface of the present invention. .. The surface on the display panel on which the LED chips 7 are arranged is laminated with the first adhesive layer 1 of the optical laminate 20. In FIG. 6, the self-luminous display device (mini / micro LED display device) 31 is subjected to antireflection treatment and / or antiglare treatment 4 on the surface 3a of the self-luminous display device (mini / micro LED display device) 30. Has been done. In FIG. 7, the self-luminous display device (mini / micro LED display device) 32 has an anti-glare layer on the surface 3a of the self-luminous display device (mini / micro LED display device) 30 as antireflection treatment and / or anti-glare treatment. 4a is formed.

In the present embodiment, a metal wiring layer 6 for sending a light emission control signal to each LED chip 7 is laminated on the substrate 5 of the display panel. The LED chips 7 that emit light of each color of red (R), green (G), and blue (B) are alternately arranged on the substrate 5 of the display panel via the metal wiring layer 6. The metal wiring layer 6 is formed of a metal such as copper, and reflects the light emitted from each LED chip 7 to reduce the visibility of the image. Further, the light emitted from each LED chip 7 of each color of RGB is mixed, and the contrast is lowered.

In the present embodiment, each LED chip 7 arranged on the display panel is tightly sealed by the first adhesive layer 1. That is, the first pressure-sensitive adhesive layer 1 can serve as a sealing material for each LED chip 7.

In the present embodiment, the first pressure-sensitive adhesive layer 1 seals between the LED chips 7 arranged on the display panel and the metal wiring layer 6. Since the visible light transmittance of the first pressure-sensitive adhesive layer 1 is lower than the visible light transmittance of the second pressure-sensitive adhesive layer 2, it has sufficient light-shielding property in the visible light region. Since the first adhesive layer 1 having a higher light-shielding property seals between the LED chips 7 without a gap, it is possible to prevent color mixing between the LED chips 7 and improve the contrast. Further, since the first adhesive layer 1 having a higher light-shielding property also seals the surface of the metal wiring layer 6, reflection by the metal wiring layer 6 can be prevented.

In the present embodiment, the second adhesive layer 2 is laminated on the upper part (display image side) of each LED chip 7 arranged on the display panel via the first base material S, and the second base material 3 is attached. It functions as an interlayer filler for bonding. Since the visible light transmittance of the second pressure-sensitive adhesive layer 2 is higher than the visible light transmittance of the first pressure-sensitive adhesive layer 1, it has sufficient transparency in the visible light region. Since the second adhesive layer 2 having higher transparency is located on the upper part (display image side) of each LED chip 7, the absorption of visible light emitted from each LED chip 7 is suppressed to a low level, and the luminous efficiency is reduced. Since it can be raised, the image can be made brighter. Further, since it is not necessary to increase the output to increase the emission brightness, the power consumption can be suppressed to a low level.

The mini / micro LED display devices 30 to 32 of the present embodiment each have a display panel in which a plurality of LED chips 7 are arranged on one side of a substrate 5, and a first pressure-sensitive adhesive layer of the optical laminates 20 to 22 of the present embodiment. Can be manufactured by laminating. At that time, the second base material 3 can be a cover member forming the outermost surface layer of the self-luminous display device (mini / micro LED display device). Therefore, according to the present embodiment, the step of separately attaching the cover member can be omitted, the required members and the number of steps can be reduced, and the production efficiency can be improved.

Further, in the mini / micro LED display device 31 of the present embodiment, the surface 3a of the second base material 3 is subjected to antireflection treatment and / or antiglare treatment 4, and in the mini / micro LED display device 32, the first An anti-glare layer 4a is formed on the surface 3a of the base material 3 as an anti-glare treatment. The antireflection treatment and / or the antiglare treatment 4, particularly the antiglare layer 4a, prevents deterioration of visibility due to reflection of external light or reflection of an image on the surface 3a of the second base material 3 as a cover member, and / Alternatively, the appearance such as glossiness is adjusted.
Hereinafter, each configuration will be described in detail.

<First base material>
In the present embodiment, the first base material S is not particularly limited, and examples thereof include glass and a transparent plastic film base material. The transparent plastic film base material is not particularly limited, but is preferably one having excellent light transmittance of visible light and excellent transparency (preferably one having a haze value of 5% or less), and for example, JP-A-2008-90263. The transparent plastic film base material described in the above can be mentioned. As the transparent plastic film base material, one having less birefringence optically is preferably used. In the present embodiment, the first base material S can be used, for example, as a constituent optical member of a self-luminous display device. In this case, the transparent plastic film base material is triacetyl cellulose (TAC). A film formed of polyester (eg, polyethylene terephthalate, polyethylene naphthalate, etc.), polycarbonate, acrylic polymer, polyolefin having a cyclic or norbornene structure, or the like is preferable.

In the optical laminate of the present embodiment, the visible light transmittance T _S of the first visible light transmittance T ₁ of the adhesive layer 1, and the first substrate S is preferably satisfy T ₁ <T _S. In this configuration, the first base material S, which exhibits a higher visible light transmittance than the first pressure-sensitive adhesive layer 1, is located above the light emitting element (image display side), and the luminous efficiency is improved to display an image. It is preferable in that it can be brightened and the power consumption due to the increase in output for increasing the luminous brightness can be reduced. The visible light transmittance T ₃ of the first base material S is not particularly limited, but may be, for example, 85 to 100%, and may be 88% or more, 90% or more, or 92% or more.

In the present embodiment, the thickness of the first base material S is not particularly limited, but is preferably in the range of 10 to 500 μm, more preferably in consideration of, for example, workability such as strength and handleability and thin layer property. Is in the range of 20 to 300 μm, and optimally in the range of 30 to 200 μm. The refractive index of the first base material S is not particularly limited, but is, for example, in the range of 1.30 to 1.80, preferably in the range of 1.40 to 1.70.

<Second base material>
In the present embodiment, the second base material 3 is not particularly limited, and examples thereof include glass and a transparent plastic film base material. The transparent plastic film base material is not particularly limited, but is preferably one having excellent light transmittance of visible light and excellent transparency (preferably one having a haze value of 5% or less), and for example, JP-A-2008-90263. The transparent plastic film base material described in the above can be mentioned. As the transparent plastic film base material, one having less birefringence optically is preferably used. In the present embodiment, the second base material 3 can be used, for example, as a cover member of a self-luminous display device. In this case, the transparent plastic film base material includes triacetyl cellulose (TAC) or polycarbonate. , Acrylic polymers, films formed from polyolefins having a cyclic or norbornene structure and the like are preferable. Further, in the present embodiment, the second base material 3 may be the cover member itself. With such a configuration, it is possible to reduce the steps of separately laminating the cover members in the manufacture of the self-luminous display device, so that the number of steps and the required members can be reduced, and the production efficiency can be improved. Further, with such a configuration, the cover member can be made thinner. When the second base material 3 is a cover member, the surface 3a is the outermost surface of the self-luminous display device.

In the optical laminate of the present embodiment, the visible light transmittance T ₃ of the first visible light transmittance T ₁ of the adhesive layer 1, and the second substrate 3, it is preferable to satisfy T ₁ <T _3. In this configuration, the second base material 3 showing a higher visible light transmittance than the first pressure-sensitive adhesive layer 1 is located above the light emitting element (image display side), and the luminous efficiency is improved to display an image. It is preferable in that it can be brightened and the power consumption due to the increase in output for increasing the luminous brightness can be reduced. The visible light transmittance T ₃ of the second base material 3 is not particularly limited, but may be, for example, 85 to 100%, and may be 88% or more, 90% or more, or 92% or more.

In the present embodiment, the thickness of the second base material 3 is not particularly limited, but is preferably in the range of 10 to 500 μm, more preferably in consideration of, for example, workability such as strength and handleability and thin layer property. Is in the range of 20 to 300 μm, and optimally in the range of 30 to 200 μm. The refractive index of the second base material 3 is not particularly limited, but is, for example, in the range of 1.30 to 1.80, preferably in the range of 1.40 to 1.70.

In the present embodiment, it is preferable that the surface 3a of the second base material 3 is subjected to a reflective surface treatment and / or an anti-glare treatment 4. When the surface 3a of the second base material 3 is subjected to the reflective surface treatment and / or the anti-glare treatment 4, the surface 3a becomes the outermost surface of the self-luminous display device, and is caused by reflection of external light, reflection of an image, or the like. It is possible to prevent a decrease in visibility or adjust the appearance such as glossiness. An anti-glare treatment that is easy to manufacture and low in cost is preferable.

As the antireflection treatment, a known antireflection treatment can be used without particular limitation, and examples thereof include an antireflection (AR) treatment.

As the antireflection (AR) treatment, a known AR treatment can be applied without particular limitation. Specifically, an optical thin film whose thickness and refractive index are strictly controlled on the surface 3a of the second base material 3 Alternatively, it can be carried out by forming an antireflection layer (AR layer) in which two or more layers of the optical thin films are laminated. The AR layer exhibits an antireflection function by canceling each other's reversed phases of incident light and reflected light by utilizing the interference effect of light. The wavelength region of visible light that exhibits the antireflection function is, for example, 380 to 780 nm, and the wavelength region having particularly high visual sensitivity is in the range of 450 to 650 nm, and the reflectance of 550 nm, which is the central wavelength thereof, is minimized. It is preferable to design the AR layer as described above.

Examples of the AR layer include a multi-layer antireflection layer having a structure in which two or five optical thin layers (thin films whose thickness and refractive index are strictly controlled) are laminated, and components having different refractive indexes are specified. By forming multiple layers with the same thickness as the above, the degree of freedom in the optical design of the AR layer is increased, the antireflection effect can be further improved, and the spectral reflection characteristics can be made uniform (flat) in the visible light region. become. Since high thickness accuracy is required for the optical thin film, the formation of each layer is generally carried out by a dry method such as vacuum vapor deposition, sputtering, or CVD.

As the anti-glare (AG) treatment, a known AG treatment can be applied without particular limitation, and can be carried out, for example, by forming an anti-glare layer 4a on the surface 3a of the second base material 3. As the anti-glare layer 4a, known ones can be adopted without limitation, and generally, it is formed as a layer in which inorganic or organic particles are dispersed as an anti-glare agent in a resin.

In the present embodiment, the anti-glare layer 4a is formed by using an anti-glare layer forming material containing a resin, particles and a thixotropy-imparting agent, and the surface of the anti-glare layer 4a is formed by agglutination of the particles and the thixotropy-imparting agent. A convex portion is formed on the surface. Due to this configuration, the anti-glare layer 4a has excellent display characteristics that achieve both anti-glare properties and prevention of white blur, and despite the fact that the anti-glare layer is formed by utilizing the aggregation of particles, the appearance is defective. It is possible to prevent the generation of protrusions on the surface of the anti-glare layer and improve the yield of the product.

Examples of the resin include thermosetting resins and ionizing radiation curable resins that are cured by ultraviolet rays or light. As the resin, a commercially available thermosetting resin, an ultraviolet curable resin, or the like can also be used.

As the heat-curable resin or the ultraviolet-curable resin, for example, a curable compound having at least one of an acrylate group and a methacrylate group that is cured by heat, light (ultraviolet rays, etc.), an electron beam, or the like can be used. Silicone resin, polyester resin, polyether resin, epoxy resin, urethane resin, alkyd resin, spiroacetal resin, polybutadiene resin, polythiol polyene resin, oligomers such as methacrylate and prepolymers of polyfunctional compounds such as polyhydric alcohol can give. One of these may be used alone, or two or more thereof may be used in combination.

For the resin, for example, a reactive diluent having at least one group of an acrylate group and a methacrylate group can also be used. As the reactive diluent, for example, the reactive diluent described in JP-A-2008-88309 can be used, and includes, for example, monofunctional acrylate, monofunctional methacrylate, polyfunctional acrylate, polyfunctional methacrylate and the like. As the reactive diluent, trifunctional or higher functional acrylates and trifunctional or higher functional methacrylates are preferable. This is because the hardness of the anti-glare layer 4a can be made excellent. Examples of the reactive diluent include butanediol glycerin ether diacrylate, isocyanuric acid acrylate, and isocyanuric acid methacrylate. One of these may be used alone, or two or more thereof may be used in combination.

The main function of the particles for forming the anti-glare layer 4a is to shape the surface of the formed anti-glare layer 4a into an uneven shape to impart anti-glare properties, and to control the haze value of the anti-glare layer 4a. The haze value of the anti-glare layer 4a can be designed by controlling the difference in refractive index between the particles and the resin. Examples of the particles include inorganic particles and organic particles. The inorganic particles are not particularly limited, and for example, silicon oxide particles, titanium oxide particles, aluminum oxide particles, zinc oxide particles, tin oxide particles, calcium carbonate particles, barium sulfate particles, talc particles, kaolin particles, calcium sulfate particles and the like. Can be given. The organic particles are not particularly limited, and for example, polymethylmethacrylate resin powder (PMMA fine particles), silicone resin powder, polystyrene resin powder, polycarbonate resin powder, acrylic styrene resin powder, benzoguanamine resin powder, melamine resin powder, and polyolefin. Examples thereof include resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, and polyfluorinated ethylene resin powder. One type of these inorganic particles and organic particles may be used alone, or two or more types may be used in combination.

The weight average particle size (D) of the particles is preferably in the range of 2.5 to 10 μm. By setting the weight average particle size of the particles in the above range, for example, more excellent anti-glare properties and white blurring can be prevented. The weight average particle size of the particles is more preferably in the range of 3 to 7 μm. The weight average particle size of the particles can be measured by, for example, the Coulter counting method. For example, using a particle size distribution measuring device (trade name: Coulter Multisizer, manufactured by Beckman Coulter) using the pore electrical resistance method, an electrolytic solution corresponding to the volume of the particles when the particles pass through the pores. By measuring the electrical resistance, the number and volume of the particles are measured, and the weight average particle size is calculated.

The shape of the particles is not particularly limited, and may be, for example, a bead-shaped substantially spherical shape or an irregular shape such as powder, but a substantially spherical shape is preferable, and an aspect ratio is more preferable. It is a substantially spherical particle having a ratio of 1.5 or less, and most preferably a spherical particle.

The proportion of the particles in the anti-glare layer 4a is preferably in the range of 0.2 to 12 parts by weight, more preferably in the range of 0.5 to 12 parts by weight, still more preferably 1 with respect to 100 parts by weight of the resin. It is in the range of ~ 7 parts by weight. Within the above range, for example, more excellent anti-glare property and white blurring can be prevented.

Examples of the thixotropy-imparting agent for forming the anti-glare layer 4a include organic clay, polyolefin oxide, modified urea and the like.

The organic clay is preferably an organically treated clay in order to improve the affinity with the resin. Examples of the organic clay include layered organic clay. The organic clay may be prepared in-house or a commercially available product may be used. Examples of the commercially available products include Lucentite SAN, Lucentite STN, Lucentite SEN, Lucentite SPN, Somasif ME-100, Somasif MAE, Somasif MTE, Somasif MEE, and Somasif MPE (trade names, all of which are CO-OP CHEMICAL CO., LTD. ); Esben, Esben C, Esben E, Esben W, Esben P, Esben WX, Esben N-400, Esben NX, Esben NX80, Esben NO12S, Esben NEZ, Esben NO12, Esben NE, Esben NZ, Esben NZ70, Organite, Organite D, Organite T (trade name, all manufactured by Hojun Co., Ltd.); Kunipia F, Kunipia G, Kunipia G4 (trade name, all manufactured by Kunimine Kogyo Co., Ltd.); Chixogel VZ, Clayton HT , Clayton 40 (trade name, all manufactured by Rockwood Additives) and the like.

The polyolefin oxide may be prepared in-house or a commercially available product may be used. Examples of the commercially available product include Disparon 4200-20 (trade name, manufactured by Kusumoto Kasei Co., Ltd.), Fronon SA300 (trade name, manufactured by Kyoeisha Chemical Co., Ltd.) and the like.

The modified urea is a reaction product of an isocyanate monomer or an adduct thereof and an organic amine. The modified urea may be prepared in-house or a commercially available product may be used. Examples of the commercially available product include BYK410 (manufactured by Big Chemie).

The thixotropy-imparting agent may be used alone or in combination of two or more.

In the present embodiment, the height of the convex portion from the roughness average line of the anti-glare layer 4a is preferably less than 0.4 times the thickness of the anti-glare layer 4a. More preferably, it is in the range of 0.01 times or more and less than 0.4 times, and further preferably, it is in the range of 0.01 times or more and less than 0.3 times. Within this range, it is possible to suitably prevent the formation of protrusions, which are defects in appearance, on the convex portion. The anti-glare layer 4a of the present embodiment has a convex portion having such a height, so that appearance defects can be less likely to occur. Here, the height from the average line can be measured by, for example, the method described in JP-A-2017-138620.

The ratio of the thixotropy-imparting agent in the anti-glare layer 4a is preferably in the range of 0.1 to 5 parts by weight, more preferably in the range of 0.2 to 4 parts by weight, based on 100 parts by weight of the resin.

The thickness (d) of the anti-glare layer 4a is not particularly limited, but is preferably in the range of 3 to 12 μm. By setting the thickness (d) of the anti-glare layer 4a within the above range, for example, the occurrence of curl of the optical laminate 12 can be prevented, and the problem of reduced productivity such as poor transportability can be avoided. When the thickness (d) is in the range, the weight average particle size (D) of the particles is preferably in the range of 2.5 to 10 μm as described above. When the thickness (d) of the anti-glare layer 4a and the weight average particle size (D) of the particles are the combination described above, the anti-glare property can be further improved. The thickness (d) of the anti-glare layer 4a is more preferably in the range of 3 to 8 μm.

The relationship between the thickness (d) of the anti-glare layer 4a and the weight average particle size (D) of the particles is preferably in the range of 0.3 ≦ D / d ≦ 0.9. By having such a relationship, it is possible to obtain an anti-glare layer which is more excellent in anti-glare property, can prevent white blurring, and has no appearance defect.

In the optical laminate 12 of the present embodiment, as described above, the anti-glare layer 4a forms a convex portion on the surface of the anti-glare layer 4a by aggregating the particles and the thixotropy-imparting agent. In the agglomerated portion forming the convex portion, a plurality of the particles are present in a state of being gathered in the plane direction of the anti-glare layer 4a. As a result, the convex portion has a gentle shape. By having the convex portion having such a shape, the anti-glare layer 4a of the present embodiment can maintain anti-glare properties, prevent white blurring, and further reduce appearance defects. can.

The surface shape of the anti-glare layer 4a can be arbitrarily designed by controlling the aggregated state of the particles contained in the anti-glare layer forming material. The agglomerated state of the particles can be controlled by, for example, the material of the particles (for example, the chemically modified state of the particle surface, the affinity for a solvent or a resin, etc.), the type of the resin (binder) or the solvent, the combination, and the like. Here, in the present embodiment, the aggregated state of the particles can be controlled by the thixotropy-imparting agent contained in the antiglare layer forming material. As a result, in the present embodiment, the agglomerated state of the particles can be made as described above, and the convex portion can be made into a gentle shape.

In the optical laminate 12 of the present embodiment, when the second base material 3 is formed of a resin or the like, it is preferable to have a permeation layer at the interface between the second base material 3 and the anti-glare layer 4a. The permeation layer is formed by permeating the resin component contained in the material for forming the antiglare layer 4a into the second base material 3. When the permeation layer is formed, the adhesion between the second base material 3 and the anti-glare layer 4a can be improved, which is preferable. The permeation layer preferably has a thickness in the range of 0.2 to 3 μm, more preferably in the range of 0.5 to 2 μm. For example, when the second base material 3 is triacetyl cellulose and the resin contained in the anti-glare layer 4a is an acrylic resin, the permeation layer can be formed. The permeation layer can be confirmed, for example, by observing the cross section of the optical laminate 12 with a transmission electron microscope (TEM), and the thickness can be measured.

In the present embodiment, even when applied to the optical laminate 12 having such a penetrating layer, a desired smooth surface uneven shape having both anti-glare property and prevention of white blur can be easily formed. Can be done. It is preferable that the permeation layer is formed thicker as the second base material 3 has poor adhesion to the anti-glare layer 4a in order to improve the adhesion.

In the present embodiment, it is preferable that the anti-glare layer 4a has one or less appearance defects having a maximum diameter of 200 μm or more ^{per 1 m 2 of the anti-glare layer 4a.} More preferably, there is no such appearance defect.

In the present embodiment, the second base material 3 on which the anti-glare layer 4a is formed preferably has a haze value in the range of 0 to 10%. The haze value is a haze value (cloudiness) according to JIS K 7136 (2000 version). The haze value is more preferably in the range of 0 to 5%, and even more preferably in the range of 0 to 3%. In order to set the haze value in the above range, it is preferable to select the particles and the resin so that the difference in refractive index between the particles and the resin is in the range of 0.001 to 0.02. When the haze value is in the above range, a clear image can be obtained and the contrast in a dark place can be improved.

In this embodiment, the average inclination angle θa (°) is determined in the uneven shape of the surface of the anti-glare layer 4a. It is preferably in the range of 1 to 5.0, more preferably in the range of 0.3 to 4.5, further preferably in the range of 1.0 to 4.0, and 1.6 to 4 It is particularly preferably 0.0. Here, the average inclination angle θa is a value defined by the following mathematical formula (1). The average inclination angle θa is, for example, a value measured by the method described in JP-A-2017-138620.
Average inclination angle θa = tan-1Δa (1)

In the above formula (1), Δa is the peak and valley of the adjacent peaks in the reference length L of the roughness curve defined in JIS B 0601 (1994 version), as shown in the following formula (2). It is a value obtained by dividing the total (h1 + h2 + h3 ... + Hn) of the difference (height h) from the lowest point by the reference length L. The roughness curve is a curve obtained by removing a surface waviness component longer than a predetermined wavelength from a cross-sectional curve with a phase difference compensation type high frequency filter. Further, the cross-sectional curve is a contour that appears at the cut end when the target surface is cut on a plane perpendicular to the target surface.
Δa = (h1 + h2 + h3 ... + hn) / L (2)

When θa is in the above range, the anti-glare property is more excellent and white blurring can be prevented.

In forming the anti-glare layer 4a, it is preferable that the prepared anti-glare layer forming material (coating liquid) exhibits thixotropic properties, and the Ti value defined below is in the range of 1.3 to 3.5. It is preferably in the range of 1.3 to 2.8.
Ti value = β1 / β2
Here, β1 is a viscosity measured under the condition of a shear rate of 20 (1 / s) using a HAAKE Leostress 6000, and β2 is a viscosity of 200 (1 / s) using a HAAKE Leostress 6000. Viscosity measured under conditions.

If the Ti value is less than 1.3, appearance defects are likely to occur, and the characteristics regarding anti-glare property and white blur are deteriorated. Further, when the Ti value exceeds 3.5, the particles are less likely to aggregate and are likely to be in a dispersed state.

The method for producing the anti-glare layer 4a of the present embodiment is not particularly limited and may be produced by any method. For example, the anti-glare layer forming material (coating) containing the resin, the particles, the thixotropy-imparting agent and the solvent. Liquid) is prepared, the anti-glare layer forming material (coating liquid) is applied to the surface 3a of the second base material 3 to form a coating film, and the coating film is cured to form an anti-glare layer 4a. As a result, it can be manufactured. In the present embodiment, a transfer method using a mold, a method of imparting an uneven shape by an appropriate method such as sandblasting or embossing roll, or the like can also be used.

The solvent is not particularly limited, and various solvents can be used, and one type may be used alone or two or more types may be used in combination. There are optimum solvent types and solvent ratios depending on the composition of the resin, the types of the particles and the thixotropy-imparting agent, the content, and the like. The solvent is not particularly limited, but for example, alcohols such as methanol, ethanol, isopropyl alcohol, butanol and 2-methoxyethanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclopentanone; methyl acetate and ethyl acetate. , Esters such as butyl acetate; ethers such as diisopropyl ether and propylene glycol monomethyl ether; glycols such as ethylene glycol and propylene glycol; cellosolves such as ethyl cellosolve and butyl cellosolve; aliphatic hydrocarbons such as hexane, heptane and octane. Kind: Aromatic hydrocarbons such as benzene, toluene, xylene and the like.

When, for example, triacetyl cellulose (TAC) is used as the second base material 3 to form the permeation layer, a good solvent for TAC can be preferably used. Examples of the solvent include ethyl acetate, methyl ethyl ketone, cyclopentanone and the like.

Further, by appropriately selecting the solvent, the thixotropy of the thixotropy-imparting agent can be satisfactorily exhibited in the antiglare layer forming material (coating liquid). For example, when organic clay is used, toluene and xylene can be preferably used alone or in combination. For example, when polyolefin oxide is used, methyl ethyl ketone, ethyl acetate, and propylene glycol monomethyl ether are preferably used alone. It can be used or used in combination. For example, when modified urea is used, butyl acetate and methyl isobutyl ketone can be preferably used alone or in combination.

Various leveling agents can be added to the anti-glare layer forming material. As the leveling agent, for example, a fluorine-based or silicone-based leveling agent can be used for the purpose of preventing uneven coating (uniformizing the coated surface). In the present embodiment, depending on the case where the surface of the anti-glare layer 4a is required to have antifouling property, or the case where an antireflection layer (low refractive index layer) or a layer containing an interlayer filler is formed on the anti-glare layer 4a. Therefore, the leveling agent can be appropriately selected. In the present embodiment, for example, by incorporating the thixotropy-imparting agent, the thixotropy can be exhibited in the coating liquid, so that uneven coating is less likely to occur. Therefore, the present embodiment has an advantage that, for example, the options of the leveling agent can be expanded.

The blending amount of the leveling agent is, for example, 5 parts by weight or less, preferably 0.01 to 5 parts by weight, based on 100 parts by weight of the resin.

Pigments, fillers, dispersants, plasticizers, ultraviolet absorbers, surfactants, antifouling agents, antioxidants and the like are added to the anti-glare layer forming material, if necessary, as long as the performance is not impaired. You may. One type of these additives may be used alone, or two or more types may be used in combination.

As the anti-glare layer forming material, for example, a conventionally known photopolymerization initiator as described in JP-A-2008-88309 can be used.

Examples of the method of applying the anti-glare layer forming material on the surface 3a of the second base material 3 include a fanten coating method, a die coating method, a spin coating method, a spray coating method, a gravure coating method, a roll coating method, and a bar. A coating method such as a coating method can be used.

The anti-glare layer forming material is applied to form a coating film on the second base material 3, and the coating film is cured. It is preferable to dry the coating film prior to the curing. The drying may be, for example, natural drying, air drying by blowing wind, heat drying, or a method in which these are combined.

The means for curing the coating film of the anti-glare layer forming material is not particularly limited, but ultraviolet curing is preferable. The irradiation amount of the energy radiation source is preferably ^{50 to 500 mJ / cm 2} as the integrated exposure amount at the ultraviolet wavelength of 365 nm. When the irradiation amount is 50 mJ / cm ² or more, the curing becomes more sufficient, and the hardness of the formed anti-glare layer becomes more sufficient. Further, if it is 500 mJ / cm ² or less, coloring of the formed anti-glare layer can be prevented.

As described above, the anti-glare layer 4a can be formed on the surface 3a of the second base material 3. The anti-glare layer 4a may be formed by a manufacturing method other than the above-mentioned method. The hardness of the anti-glare layer 4a of the present embodiment is affected by the thickness of the layer in terms of pencil hardness, but it is preferably 2H or more.

In the present embodiment, the anti-glare layer 4a may have a multi-layer structure in which two or more layers are laminated.

In the present embodiment, the above-mentioned AR layer (low refractive index layer) may be arranged on the anti-glare layer 4a. For example, when the optical laminate 12 according to the present embodiment is attached to the self-luminous display device, one of the factors that reduce the visibility of the image is the reflection of light at the interface between the air and the anti-glare layer. The AR layer reduces its surface reflection. The anti-glare layer 3a and the anti-reflection layer may each have a multi-layer structure in which two or more layers are laminated.

Further, in order to prevent the adhesion of contaminants and improve the ease of removing the adhered contaminants, a contamination prevention layer formed of a fluorine group-containing silane compound, a fluorine group-containing organic compound, or the like is provided on the antiglare layer 4a. It is preferable to stack them.

In the present embodiment, it is preferable to perform surface treatment on at least one of the second base material 3 and the anti-glare layer 4a. If the surface of the second base material 3 is surface-treated, the adhesion to the anti-glare layer 4a is further improved. Further, if the surface of the anti-glare layer 4a is surface-treated, the adhesion to the AR layer is further improved.

In order to prevent curling of the second base material 3, the other surface of the anti-glare layer 4a may be treated with a solvent. Further, in order to prevent the occurrence of curl, a transparent resin layer may be formed on the other surface of the anti-glare layer 4a.

<Adhesive layer>
In the present embodiment, the first pressure-sensitive adhesive layer 1 and the second pressure-sensitive adhesive layer 2 are pressure-sensitive adhesive layers formed from a pressure-sensitive adhesive composition selected from a photocurable pressure-sensitive adhesive composition and a solvent-type pressure-sensitive adhesive composition. ..

In the present embodiment, both the first pressure-sensitive adhesive layer 1 and the second pressure-sensitive adhesive layer 2 may be a pressure-sensitive adhesive layer formed of a photocurable pressure-sensitive adhesive composition, and both may be a solvent-type pressure-sensitive adhesive composition. It may be a pressure-sensitive adhesive layer formed from, one is a pressure-sensitive adhesive layer formed from a photocurable pressure-sensitive adhesive composition, and the other is a pressure-sensitive adhesive layer formed from a solvent-type pressure-sensitive adhesive composition. May be good.

In the present embodiment, the first pressure-sensitive adhesive layer 1 is preferably a pressure-sensitive adhesive layer formed from a solvent-type pressure-sensitive adhesive composition because it is excellent in step absorption and processability. On the other hand, the second pressure-sensitive adhesive layer 2 may be a pressure-sensitive adhesive layer formed from a photocurable pressure-sensitive adhesive composition or a pressure-sensitive adhesive layer formed from a solvent-type pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer 1 preferably contains a colorant. When the pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer 1 contains a colorant, the transparency of the first pressure-sensitive adhesive layer 1 to visible light is lowered, and _{T 1 and T 2} are T ₁ <T. It is preferable to have a configuration that satisfies _2. The first pressure-sensitive adhesive layer 1 having reduced transparency to visible light and imparted light-shielding property is used between the metal wiring layer 6 of the self-luminous display device (mini / micro LED display device) of the present embodiment and the LED chip. By sealing, reflection due to metal wiring or the like is prevented, color mixing between LED chips is prevented, and image contrast is improved.

Pressure-sensitive adhesive composition for forming the second adhesive layer 2 may also contain a coloring agent, from the viewpoint of the T _1, and the T ₂ is configured to satisfy T ₁ <T _2, colorants Is preferably not contained.

<Photocurable adhesive composition>
The photocurable pressure-sensitive adhesive composition contains a polymer, a photopolymerizable compound, and a photopolymerization initiator. That is, the photocurable pressure-sensitive adhesive composition used for forming the first pressure-sensitive adhesive layer 1 and the second pressure-sensitive adhesive layer 2 of the present embodiment contains a polymer, a photopolymerizable compound, and a photopolymerization initiator. ..

The pressure-sensitive adhesive layer formed by using the photocurable pressure-sensitive adhesive composition is a type that performs photo-curing (first form) and a type that does not perform photo-curing and is photo-cured after being bonded to a display panel described later. It is roughly divided into types (second form). Both the first pressure-sensitive adhesive layer 1 and the second pressure-sensitive adhesive layer 2 may be the pressure-sensitive adhesive layer of the first form, both may be the pressure-sensitive adhesive layer of the second form, and one of them may be the first type. One form of the pressure-sensitive adhesive layer and the other may be the second form of the pressure-sensitive adhesive layer.

[First form]
The pressure-sensitive adhesive layer of the first form is formed by applying a photocurable pressure-sensitive adhesive composition containing a polymer, a photopolymerizable compound, and a photopolymerization initiator on a release film and performing photo-curing. can do.

<Photocurable adhesive composition>
(polymer)
Examples of the polymer contained in the photocurable pressure-sensitive adhesive composition include acrylic polymers, silicone-based polymers, polyesters, polyurethanes, polyamides, polyvinyl ethers, vinyl acetate / vinyl chloride copolymers, modified polyolefins, epoxy-based polymers, fluorine-based polymers, and natural rubbers. , Rubber-based polymers such as synthetic rubber, and the like. In particular, an acrylic polymer is preferably used because it exhibits adhesive properties such as appropriate wettability, cohesiveness and adhesiveness, and is also excellent in weather resistance and heat resistance.

The acrylic polymer contains (meth) acrylic acid alkyl ester as a main constituent monomer component. In addition, in this specification, "(meth) acrylic" means acrylic and / or methacryl. The amount of the (meth) acrylic acid alkyl ester with respect to the total amount of the monomer components constituting the acrylic polymer is preferably 50% by weight or more, more preferably 55% by weight or more, still more preferably 60% by weight or more.

As the (meth) acrylic acid alkyl ester, a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 20 carbon atoms is preferably used. The (meth) acrylic acid alkyl ester may have a branched alkyl group or a cyclic alkyl group.

Specific examples of the (meth) acrylic acid alkyl ester having a chain alkyl group include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylate, and (meth). S-butyl acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, neopentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, 2-Ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate , (Meta) undecyl acrylate, (meth) dodecyl acrylate, (meth) isotridodecyl acrylate, (meth) tetradecyl acrylate, (meth) isotetradecyl acrylate, (meth) pentadecyl acrylate, (meth) Examples thereof include cetyl acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, isooctadecil (meth) acrylate, and nonadecil (meth) acrylate. Examples of the (meth) acrylic acid alkyl ester having a preferable chain alkyl group used in the first form include butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octadecyl (meth) acrylate, and (meth) acrylic. Dodecyl acid. The amount of the (meth) acrylic acid alkyl ester having a chain alkyl group with respect to the total amount of the monomer components constituting the acrylic polymer is, for example, about 40 to 90% by weight, and 45 to 80% by weight or 50 to 70% by weight. There may be.

Specific examples of the (meth) acrylic acid alkyl ester having an alicyclic alkyl group include cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, cycloheptyl (meth) acrylate, cyclooctyl (meth) acrylate and the like. (Meta) acrylic acid cycloalkyl ester; (meth) acrylic acid ester having a bicyclic aliphatic hydrocarbon ring such as (meth) acrylic acid isobornyl; dicyclopentanyl (meth) acrylate, dicyclopentanyloxy Three rings such as ethyl (meth) acrylate, tricyclopentanyl (meth) acrylate, 1-adamantyl (meth) acrylate, 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) acrylate Examples thereof include (meth) acrylic acid esters having the above aliphatic hydrocarbon rings. Examples of the (meth) acrylic acid alkyl ester having a preferable alicyclic alkyl group used in the first form are cyclohexyl (meth) acrylic acid and isobornyl (meth) acrylic acid. The amount of the (meth) acrylic acid alkyl ester having an alicyclic alkyl group with respect to the total amount of the monomer components constituting the acrylic polymer is, for example, about 3 to 50% by weight, and 5 to 40% by weight or 10 to 30% by weight. It may be.

The acrylic polymer may contain a polar group-containing monomer such as a hydroxyl group-containing monomer, a carboxy group-containing monomer, and a nitrogen-containing monomer as a constituent monomer component. When the acrylic polymer contains a polar group-containing monomer as a constituent monomer component, the cohesive force of the pressure-sensitive adhesive is enhanced, and the adhesive force tends to be improved. Preferred polar group-containing monomers used in the first form are hydroxyl group-containing monomers and nitrogen-containing monomers. The amount of the polar group-containing monomer (total of the hydroxy group-containing monomer, the carboxy group-containing monomer, and the nitrogen-containing monomer) with respect to the total amount of the monomer components constituting the acrylic polymer is, for example, about 3 to 50% by weight, and is 5 to 40. It may be% by weight or 10 to 30% by weight.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and (meth) acrylic. Examples thereof include (meth) acrylic acid esters such as 8-hydroxyoctyl acid, 10-hydroxydecyl (meth) acrylic acid, 12-hydroxylauryl (meth) acrylic acid and (4-hydroxymethylcyclohexyl) -methyl (meth) acrylate. .. When a cross-linked structure is introduced into the polymer by an isocyanate cross-linking agent, the hydroxyl group can be a reaction point (cross-linking point) with the isocyanate group. Preferred hydroxyl group-containing monomers used in the first form are 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate. The amount of the hydroxyl group-containing monomer with respect to the total amount of the monomer components constituting the acrylic polymer is, for example, about 3 to 50% by weight, and may be 5 to 40% by weight or 10 to 30% by weight.

Examples of the carboxy group-containing monomer include acrylic monomers such as (meth) acrylic acid, carboxyethyl (meth) acrylate, and carboxypentyl (meth) acrylate, and itaconic acid, maleic acid, fumaric acid, and crotonic acid. .. When a crosslinked structure is introduced into the polymer by an epoxy-based crosslinking agent, the carboxy group can be a reaction point (crosslinking point) with the epoxy group. A preferred carboxy group-containing monomer used in the first form is (meth) acrylic acid. The amount of the carboxy group-containing monomer with respect to the total amount of the monomer components constituting the acrylic polymer is, for example, about 3 to 50% by weight, and may be 5 to 40% by weight or 10 to 30% by weight.

Examples of the nitrogen-containing monomer include N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, vinylmorpholin, (meth) acryloylmorpholin, and N-vinyl. Examples thereof include vinyl-based monomers such as carboxylic acid amides, N-vinylcaprolactam and acrylamide, and cyano group-containing monomers such as acrylonitrile and methacrylonitrile. The preferred nitrogen-containing monomer used in the first form is N-vinylpyrrolidone. The amount of the nitrogen-containing monomer with respect to the total amount of the monomer components constituting the acrylic polymer is, for example, about 3 to 50% by weight, and may be 5 to 40% by weight or 10 to 30% by weight.

Acrylic polymers contain acid anhydride group-containing monomers, (meth) acrylic acid caprolactone adducts, sulfonic acid group-containing monomers, and phosphoric acid groups as monomer components other than the above (sometimes referred to as "other monomers"). Vinyl-based monomers such as monomers, vinyl acetate, vinyl propionate, styrene, α-methylstyrene, etc .; Epoxy group-containing monomers such as glycidyl (meth) acrylate; Polyethylene glycol (meth) acrylate, Polypropylene glycol (meth) acrylate Glycol-based acrylic ester monomers such as methoxyethylene glycol (meth) acrylate and methoxypolypropylene glycol (meth) acrylate; tetrahydrofurfuryl (meth) acrylate, fluorine (meth) acrylate, silicone (meth) acrylate and (meth) It may contain an acrylic acid ester-based monomer such as 2-methoxyethyl acrylate.

The glass transition temperature (Tg) of the polymer contained in the photocurable pressure-sensitive adhesive composition is preferably 0 ° C. or lower. The glass transition temperature of the polymer may be −5 ° C. or lower, −10 ° C. or lower, or −15 ° C. or lower. The glass transition temperature of the polymer is the peak top temperature of the loss tangent (tan δ) measured by dynamic viscoelasticity measurement. When a crosslinked structure is introduced into the polymer, the glass transition temperature may be calculated from the composition of the polymer based on the theoretical Tg. The theoretical Tg is calculated by the Fox formula described later.

A polymer can be obtained by polymerizing the above-mentioned monomer components by various known methods. The polymerization method is not particularly limited, but it is preferable to prepare the polymer by photopolymerization. Since the polymer can be prepared without using a solvent in photopolymerization, it is not necessary to dry and remove the solvent when forming the pressure-sensitive adhesive layer, and a thick pressure-sensitive adhesive layer can be uniformly formed.

In the preparation of the pressure-sensitive adhesive layer of the first form, it is preferable to prepare it as a polymer (prepolymer) having a low degree of polymerization in which a part of the monomer components remains unreacted. The composition used for preparing the prepolymer (composition for forming the prepolymer) preferably contains a photopolymerization initiator in addition to the monomer. The photopolymerization initiator may be appropriately selected depending on the type of monomer. For example, a photoradical polymerization initiator is used for the polymerization of an acrylic polymer. Examples of the photopolymerization initiator include a benzoin ether-based photopolymerization initiator, an acetophenone-based photopolymerization initiator, an α-ketol-based photopolymerization initiator, an aromatic sulfonyl chloride-based photopolymerization initiator, and a photoactive oxime-based photopolymerization initiator. Examples thereof include benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, and acylphosphine oxide-based photopolymerization initiators.

At the time of polymerization, a chain transfer agent, a polymerization inhibitor (polymerization delaying agent) or the like may be used for the purpose of adjusting the molecular weight. Examples of the chain transfer agent include thiols such as α-thioglycerol, lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, and 2,3-dimercapto-1-propanol. Examples thereof include α-methylstyrene dimer.

The polymerization rate of the prepolymer is not particularly limited, but is preferably 3 to 50% by weight, more preferably 5 to 40% by weight, from the viewpoint of obtaining a viscosity suitable for coating on a substrate. The polymerization rate of the prepolymer can be adjusted to a desired range by adjusting the type and amount of the photopolymerization initiator, the irradiation intensity and irradiation time of active light such as UV light, and the like. The polymerization rate of the prepolymer is a non-volatile component when heated at 130 ° C. for 3 hours, and is calculated by the following formula. The polymerization rate (nonvolatile content) of the pressure-sensitive adhesive layer is also measured by the same method.
Polymerization rate (%) = weight after heating / weight before heating x 100

As described above, the photocurable pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer contains a polymer, a photopolymerizable compound, and a photopolymerization initiator. For example, a photocurable pressure-sensitive adhesive composition can be obtained by adding a photopolymerizable compound and a photopolymerization initiator to the prepolymer. Instead of using a prepolymer, a low molecular weight polymer (oligomer) is used, and the low molecular weight polymer is mixed with a photopolymerizable compound, a photopolymerization initiator and a colorant to prepare a photocurable pressure-sensitive adhesive composition. You may.

(Photopolymerizable compound)
The photopolymerizable compound contained in the photocurable pressure-sensitive adhesive composition has one or more photopolymerizable functional groups in one molecule. The photopolymerizable functional group may be radically polymerizable, cationically polymerizable or anionically polymerizable, but since it is excellent in reactivity, it is a radically polymerizable functional group having an unsaturated double bond (ethylenically unsaturated group). Is preferable.

The prepolymer contains an unreacted monomer with the polymer, and the unreacted monomer retains photopolymerizability. Therefore, it is not always necessary to add a photopolymerizable compound in the preparation of the photocurable pressure-sensitive adhesive composition. When the photopolymerizable compound is added to the prepolymer, the photopolymerizable compound to be added may be the same as or different from the monomer used for preparing the prepolymer.

When the polymer is an acrylic polymer, the compound added as the photopolymerizable compound is preferably a monomer or oligomer having a (meth) acryloyl group as the photopolymerizable functional group because it has high compatibility with the polymer. The photopolymerizable compound may be a polyfunctional compound having two or more photopolymerizable functional groups in one molecule. Examples of the photopolymerizable polyfunctional compound include polyfunctional (meth) acrylate. Examples of the polyfunctional (meth) acrylate include polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, polytetramethylene glycol di (meth) acrylate, bisphenol A ethylene oxide-modified di (meth) acrylate, and bisphenol A propylene oxide. Modified di (meth) acrylate, alcandiol di (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, pentaeristol di (meth) acrylate, neopentyl glycol di (meth) acrylate, glycerin di (meth) acrylate , Bifunctional (meth) acrylic acid esters such as urethane di (meth) acrylates; trifunctional (meth) acrylates such as pentaeristol tri (meth) acrylates, trimethylpropantri (meth) acrylates, and tri (meth) acrylates of ethoxylated isocyanuric acid. Meta) acrylic acid ester; tetrafunctional (meth) acrylic acid ester such as ditrimethylolpropane tetra (meth) acrylate, ethoxylated pentaeristol tetra (meth) acrylate, pentaeristol tetra (meth) acrylate; dipentaeryristol penta Examples thereof include (meth) acrylates and the like, and pentafunctional or higher functional (meth) acrylic acid esters such as dipentaeryristolhexa (meth) acrylate.

When a polyfunctional compound is used as the photopolymerizable compound, the amount of the polyfunctional compound used is preferably 10 parts by weight or less, more preferably 0.001 to 1 part by weight, based on 100 parts by weight of the polymer (including the prepolymer). Parts, more preferably 0.005 to 0.5 parts by weight. When the amount of the polyfunctional monomer used is excessively large, the viscosity of the pressure-sensitive adhesive layer after photocuring is low, and the adhesive strength may be poor. The amount of the polyfunctional compound used may be 10 parts by weight or less, 5 parts by weight or less, 3 parts by weight or less, or 1 part by weight or less. The amount of the polyfunctional monomer used may be 0, and may be 0.001 part by weight or more, 0.01 part by weight or more, or 0.1 part by weight or more.

When a monomer forming a prepolymer is used as the photopolymerizable compound, a hydroxyl group-containing monomer is preferable, and 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are more preferable. When a hydroxyl group-containing monomer is used as the photopolymerizable compound, the amount of the hydroxyl group-containing monomer used is preferably 40 parts by weight or less, more preferably 1 to 30 parts by weight, based on 100 parts by weight of the polymer (including the prepolymer). Yes, more preferably 5 to 20 parts by weight. The amount of the hydroxyl group-containing monomer used may be 40 parts by weight or less, 30 parts by weight or less, and 20 parts by weight or less. The amount of the hydroxyl group-containing monomer used may be 0, or may be 1 part by weight or more, 5 parts by weight or more, or 10 parts by weight or more.

(Photopolymerization initiator)
The photocurable pressure-sensitive adhesive composition contains a photopolymerization initiator. The photopolymerization initiator generates radicals, acids, bases and the like by irradiation with active light such as ultraviolet rays, and can be appropriately selected depending on the type of the photopolymerizable compound and the like. When the photopolymerizable compound is a compound having a (meth) acryloyl group (for example, a monofunctional or polyfunctional (meth) acrylate), it is preferable to use a photoradical polymerization initiator as the photopolymerization initiator. The photopolymerization initiator may be used alone or in combination of two or more.

If the photopolymerization initiator used in the preparation (polymerization) of the polymer (including the prepolymer) remains without being inactivated, the addition of the photopolymerization initiator may be omitted. When a photopolymerization initiator is added to the polymer, the photopolymerization initiator added may be the same as or different from the photopolymerization initiator used in the preparation of the polymer.

The photopolymerization initiator contained in the photocurable pressure-sensitive adhesive composition preferably has an absorption maximum in a wavelength region where light absorption by a colorant described later is small. Specifically, the photopolymerization initiator preferably has an absorption maximum in the wavelength region of 330 to 400 nm. Since the photopolymerization initiator has an absorption maximum in a region where the light absorption by the colorant is small, the curing inhibition by the colorant is suppressed, so that the polymerization rate can be sufficiently increased by the photocuring. Examples of the photoradical polymerization initiator having an absorption maximum in the wavelength region of 330 to 400 nm include hydroxyketones, benzyldimethylketals, aminoketones, acylphosphine oxides, benzophenones, trichloromethyl group-containing triazine derivatives and the like. ..

The content of the photopolymerization initiator in the photocurable pressure-sensitive adhesive composition is 0.01 to 10% by weight with respect to 100 parts by weight of the total amount of the monomers (monomer used for polymer preparation and photopolymerizable compound added to the polymer). The amount is about 0.05 to 5 parts by weight, preferably about 0.05 to 5 parts by weight.

(Colorant)
The photocurable pressure-sensitive adhesive composition used in the first form may contain a colorant. In particular, it is preferable that the photocurable pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer 1 further contains a colorant. When the photocurable pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer 1 contains a colorant, the permeability of the first pressure-sensitive adhesive layer 1 to visible light is reduced, and _{T 1 and T 2} are T. It is preferable to have a configuration that satisfies ₁ <T _2. The first pressure-sensitive adhesive layer 1 having reduced transparency to visible light and imparted light-shielding property is used between the metal wiring layer 6 of the self-luminous display device (mini / micro LED display device) of the present embodiment and the LED chip. By sealing, reflection due to metal wiring or the like is prevented, color mixing between LED chips is prevented, and image contrast is improved.

The colorant may be a dye or a pigment as long as it can be dissolved or dispersed in the photocurable pressure-sensitive adhesive composition. Dyes are preferable because low haze can be achieved even with a small amount of addition, and unlike pigments, they do not have sedimentation properties and can be easily distributed uniformly. In addition, pigments are also preferable because they have high color development even when added in a small amount. When a pigment is used as a colorant, it preferably has low or no conductivity. In addition, when a dye is used, it is preferable to use it in combination with an antioxidant described later.

The colorant is not particularly limited, but one that absorbs visible light and has ultraviolet transmittance is preferable. That is, the colorant preferably has an average transmittance at a wavelength of 330 to 400 nm higher than the average transmittance at a wavelength of 400 to 700 nm. The transmittance of the colorant is adjusted by using an appropriate solvent such as tetrahydrofuran (THF) or a dispersion medium (an organic solvent having a small absorption in the wavelength range of 330 to 700 nm) so that the transmittance at a wavelength of 400 nm is about 50 to 60%. Measure with a diluted solution or dispersion.

Examples of the ultraviolet-transparent black pigment having a smaller absorption of ultraviolet rays than the absorption of visible light include "9050BLACK" and "UVBK-0001" manufactured by Tokushiki. Examples of the ultraviolet-transparent black dye include "SOC-L-0123" manufactured by Orient Chemical Industries.

Carbon black and titanium black, which are generally used as black colorants, absorb ultraviolet rays more than they absorb visible light (the ultraviolet transmittance is smaller than the visible light transmittance). Therefore, when a colorant such as carbon black is added to the photocurable pressure-sensitive adhesive composition having sensitivity to ultraviolet rays, most of the ultraviolet rays irradiated for photocuring are absorbed by the colorant, and the amount of light absorbed by the photopolymerization initiator. Is small, and it takes time to photo-cure (the amount of integrated irradiation light increases). Further, when the thickness of the pressure-sensitive adhesive layer is large, the amount of ultraviolet rays reaching the surface opposite to the light irradiation surface is small, so that the photocuring tends to be insufficient even if the light irradiation is performed for a long time. On the other hand, by using a colorant having a higher transmittance of ultraviolet rays than visible light, it is possible to suppress curing inhibition caused by the colorant.

The content of the colorant in the photocurable pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer is, for example, about 0.01 to 20 parts by weight with respect to 100 parts by weight of the total amount of the monomers. , The color tone of the pressure-sensitive adhesive layer, the light transmittance, and the like may be appropriately set. The colorant may be added to the composition as a solution or dispersion dissolved or dispersed in an appropriate solvent.

The photocurable pressure-sensitive adhesive composition forming the second pressure-sensitive adhesive layer preferably does not contain a colorant. Since the photocurable pressure-sensitive adhesive composition forming the second pressure-sensitive adhesive layer does not contain a colorant, the transparency to visible light is increased, and the luminous efficiency of the self-luminous display device (mini / micro LED display device) is improved. improves. When the photocurable pressure-sensitive adhesive composition forming the second pressure-sensitive adhesive layer contains a colorant, the content thereof is, for example, about 0.1 part by weight or less with respect to 100 parts by weight of the total amount of the monomers. Even when the colorant is not blended in the photocurable pressure-sensitive adhesive composition forming the second pressure-sensitive adhesive layer, the colorant blended in the first pressure-sensitive adhesive layer may be transferred to the second pressure-sensitive adhesive layer.

(Silane coupling agent)
The photocurable pressure-sensitive adhesive composition may contain a silane coupling agent as long as the effects of the present invention are not impaired. When the photocurable pressure-sensitive adhesive composition contains a silane coupling agent, the adhesion reliability to the glass (particularly, the adhesion reliability to the glass in a high temperature and high humidity environment) is improved, which is preferable.

The silane coupling agent is not particularly limited, but is limited to γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-aminopropyltrimethoxysilane, and N-phenyl-aminopropyltrimethoxysilane. , 3-Acryloxypropyltrimethoxysilane and the like are preferable. Of these, γ-glycidoxypropyltrimethoxysilane is preferable. Further, as a commercially available product, for example, the product name "KBM-403" (manufactured by Shin-Etsu Chemical Co., Ltd.) can be mentioned. The silane coupling agent may be used alone or in combination of two or more.

The content of the silane coupling agent in the photocurable pressure-sensitive adhesive composition is not particularly limited, but is preferably 0.01 to 1 part by weight, more preferably 0.03 to 0.5 parts by weight, based on 100 parts by weight of the polymer. It is a part by weight.

(Other ingredients)
In the first embodiment, the photocurable pressure-sensitive adhesive composition may contain components other than the polymer, the photopolymerizable compound, the photopolymerization initiator and the colorant. For example, a chain transfer agent may be contained for the purpose of adjusting the photocuring rate or the like. Further, an oligomer or a tackifier may be contained for the purpose of adjusting the viscosity of the photocurable pressure-sensitive adhesive composition, adjusting the adhesive force of the pressure-sensitive adhesive layer, and the like. As the oligomer, for example, one having a weight average molecular weight of about 1000 to 30,000 is used. As the oligomer, an acrylic oligomer is preferable because it has excellent compatibility with an acrylic polymer. The photocurable pressure-sensitive adhesive composition may contain additives such as a plasticizer, a softener, an antioxidant, a filler, an antioxidant, a surfactant, and an antistatic agent.

[Second form]
The pressure-sensitive adhesive layer of the second form is a type of pressure-sensitive adhesive layer that is not photo-cured, and the photo-curable pressure-sensitive adhesive composition is formed in the form of a sheet. Since the pressure-sensitive adhesive layer of the second form contains the photopolymerizable compound in an unreacted state, the pressure-sensitive adhesive layer has photocurability.

The photocurable pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer of the second form contains a polymer, a photopolymerizable compound, and a photopolymerization initiator.

(polymer)
As the polymer contained in the pressure-sensitive adhesive composition, various polymers can be applied as in the first form, and an acrylic polymer is preferably used. The monomer components constituting the acrylic polymer are the same as those in the first form.

In order to introduce a crosslinked structure with a crosslinking agent described later, it is preferable that the monomer component constituting the polymer contains a hydroxy group-containing monomer and / or a carboxy group-containing monomer. For example, when an isocyanate-based cross-linking agent is used, it is preferable to contain a hydroxy group-containing monomer as a monomer component. When an epoxy-based cross-linking agent is used, it is preferable to contain a carboxy group-containing monomer as the monomer.

In the second form, since photocuring is not performed on the substrate, a polymer having a relatively large molecular weight is used as a polymer contained in the photocurable pressure-sensitive adhesive composition in order to form a solid (standard) pressure-sensitive adhesive layer. Used. The weight average molecular weight of the polymer is, for example, about 100,000 to 2 million.

Since the high molecular weight polymer is a solid, the pressure-sensitive adhesive composition is preferably a solution in which the polymer is dissolved in an organic solvent. For example, a polymer solution can be obtained by solution-polymerizing the monomer components. A polymer solution may be prepared by dissolving a solid polymer in an organic solvent.

Ethyl acetate, toluene and the like are generally used as the solvent for solution polymerization. The solution concentration is usually about 20 to 80% by weight. The polymerization initiator includes an azo-based initiator, a peroxide-based initiator, a redox-based initiator that combines a peroxide and a reducing agent (for example, a combination of a persulfate and sodium hydrogen sulfite, a peroxide and an ascorbin). A thermal polymerization initiator such as (combination of sodium acid acid) is preferably used. The amount of the polymerization initiator used is not particularly limited, but is preferably about 0.005 to 5 parts by weight, more preferably about 0.02 to 3 parts by weight, based on 100 parts by weight of the total amount of the monomer components forming the polymer. preferable.

(Photopolymerizable compound)
The photopolymerizable compound contained in the pressure-sensitive adhesive composition in the second form is the same as that described above for the first form, and a compound having one or more photopolymerizable functional groups is used.

(Photopolymerization initiator)
The photopolymerization initiator contained in the pressure-sensitive adhesive composition in the second form is the same as that described above for the first form, and preferably has an absorption maximum in the wavelength region of 330 to 400 nm. The amount of the photopolymerization initiator is about 0.01 to 10 parts by weight, preferably about 0.05 to 5 parts by weight, based on 100 parts by weight of the polymer.

(Colorant)
It may contain a pressure-sensitive adhesive composition and a colorant used in the second form. In particular, it is preferable that the photocurable pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer 1 further contains a colorant. When the photocurable pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer 1 contains a colorant, the permeability of the first pressure-sensitive adhesive layer 1 to visible light is reduced, and _{T 1 and T 2} are T. It is preferable to have a configuration that satisfies ₁ <T _2. The first pressure-sensitive adhesive layer 1 having reduced transparency to visible light and imparted light-shielding property is used between the metal wiring layer 6 of the self-luminous display device (mini / micro LED display device) of the present embodiment and the LED chip. By sealing, reflection due to metal wiring or the like is prevented, color mixing between LED chips is prevented, and image contrast is improved.

The colorant contained in the pressure-sensitive adhesive composition used in the second form is the same as that described above for the first form, and the average transmittance at a wavelength of 330 to 400 nm is larger than the average transmittance at a wavelength of 400 to 700 nm. Those are preferable.

(Crosslinking agent)
The pressure-sensitive adhesive composition of the second form preferably contains a cross-linking agent capable of cross-linking with the above polymer. Specific examples of the cross-linking agent for introducing a cross-linked structure into the polymer include an isocyanate-based cross-linking agent, an epoxy-based cross-linking agent, an oxazoline-based cross-linking agent, an aziridine-based cross-linking agent, a carbodiimide-based cross-linking agent, a metal chelate-based cross-linking agent, and the like. Be done. Of these, isocyanate-based cross-linking agents and epoxy-based cross-linking agents are preferable because they have high reactivity with the hydroxyl groups and carboxy groups of the polymer and the cross-linked structure can be easily introduced. These cross-linking agents react with functional groups such as hydroxyl groups and carboxy groups introduced into the polymer to form a cross-linked structure.

As the isocyanate-based cross-linking agent, polyisocyanate having two or more isocyanate groups in one molecule is used. Examples of the isocyanate-based cross-linking agent include lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate; 2,4-tolylene diisocyanate. Aromatic isocyanates such as isocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate; trimethylolpropane / trimylene diisocyanate trimer adduct (eg, "Coronate L" manufactured by Toso), trimethylolpropane / hexamethylene Diisocyanate trimeric adduct (eg, Tosoh's "Coronate HL"), xylylene diisocyanate trimethylolpropane adduct (eg, Mitsui Chemicals' "Takenate D110N", hexamethylene diisocyanate isocyanurate (eg, Tosoh's "Coronate HL") Examples thereof include isocyanate additives such as "Coronate HX").

As the epoxy-based cross-linking agent, a polyfunctional epoxy compound having two or more epoxy groups in one molecule is used. The epoxy group of the epoxy-based cross-linking agent may be a glycidyl group. Examples of the epoxy-based cross-linking agent include N, N, N', N'-tetraglycidyl-m-xylene diamine, diglycidyl aniline, 1,3-bis (N, N-diglycidyl aminomethyl) cyclohexane, 1, 6-Hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, penta Ellisritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipate diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris (2-hydroxyethyl) isocyanurate, Examples thereof include resorcin diglycidyl ether and bisphenol-S-diglycidyl ether. As the epoxy-based cross-linking agent, commercially available products such as "Denacol" manufactured by Nagase ChemteX and "Tetrad X" and "Tetrad C" manufactured by Mitsubishi Gas Chemical Company may be used.

The amount of the cross-linking agent is about 0.01 to 5 parts by weight with respect to 100 parts by weight of the polymer, and may be 0.05 parts by weight or more, 0.1 parts by weight or more, or 0.2 parts by weight or more. It may be 3 parts by weight or less, 2 parts by weight or less, or 1 part by weight or less.

(Other ingredients)
In addition to the above components, the pressure-sensitive adhesive composition of the second form includes oligomers, tackifiers, silane coupling agents, chain transfer agents, plasticizers, softeners, deterioration inhibitors, fillers, antioxidants, and surfactants. It may contain an agent, an antistatic agent, and the like.

In the present embodiment, the first pressure-sensitive adhesive layer 1 and the second pressure-sensitive adhesive layer 2 may be a pressure-sensitive adhesive layer (third form) formed from a solvent-type pressure-sensitive adhesive composition. The solvent-type pressure-sensitive adhesive composition contains at least a polymer and a solvent, and may contain a cross-linking agent. That is, the solvent-type pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer of the third form contains a polymer and a solvent, and may contain a cross-linking agent if necessary.

[Third form]
The pressure-sensitive adhesive layer of the third form is formed by applying a solvent-type pressure-sensitive adhesive composition containing a polymer and a solvent and, if necessary, a cross-linking agent, onto a release film and drying and removing the solvent. can do.

<Solvent type pressure-sensitive adhesive composition>
The solvent-based pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer of the third form contains a polymer and a solvent, and optionally contains a cross-linking agent.

(polymer)
As the polymer contained in the solvent-type pressure-sensitive adhesive composition, various polymers can be applied as in the first form, and an acrylic polymer is preferably used. The monomer components constituting the acrylic polymer are the same as those in the first form.

In the third form, in order to form a solid (standard) pressure-sensitive adhesive layer on the base material, a polymer having a relatively large molecular weight is used as the polymer contained in the solvent-type pressure-sensitive adhesive composition. The weight average molecular weight of the polymer is, for example, about 100,000 to 2 million.

The acrylic polymer contained in the solvent-based pressure-sensitive adhesive composition of the third form may be a (meth) acrylic block copolymer. When the first pressure-sensitive adhesive layer 1 and / or the second pressure-sensitive adhesive layer 2 is formed from a solvent-type pressure-sensitive adhesive composition containing a (meth) acrylic block copolymer, it is excellent in step absorption and processability. Since it is excellent, it can be sealed without leaving gaps in the steps of a plurality of LED chips arranged on the substrate of the display panel, and it is also excellent in workability, so that the adhesive layer is removed from the end during storage. It is unlikely that the problem of sticking out will occur.

In the present embodiment, the pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer 1 is preferably a solvent-type pressure-sensitive adhesive composition containing a (meth) acrylic block copolymer. With this configuration, the first pressure-sensitive adhesive layer 1 is excellent in step absorption and processability, and bubbles are generated in the steps in a plurality of LED chips and metal wiring arranged on the substrate of the display panel. Since the LED chips can be sealed without leaving any gaps, color mixing between the LED chips can be prevented, image contrast can be improved, and reflection due to metal wiring or the like can be efficiently prevented.

In the present embodiment, the (meth) acrylic block copolymer has a high Tg segment having a glass transition temperature of 0 ° C. or higher and 100 ° C. or lower and a low Tg segment having a glass transition temperature of -100 ° C. or higher and lower than 0 ° C. It is preferable to have a peak of tan δ in a region of 0 ° C. or higher and a region of lower than 0 ° C., respectively.

In the present specification, "high Tg segment having a glass transition temperature of 0 ° C. or higher and 100 ° C. or lower" is simply referred to as "high Tg segment", and "low Tg segment having a glass transition temperature of -100 ° C. or higher and lower than 0 ° C." is simply referred to as "high Tg segment". "Low Tg segment", the peak of tan δ in the region above 0 ° C is simply "high temperature region tan δ peak", the peak of tan δ in the region below 0 ° C is simply "low temperature region tan δ peak", the high Tg segment and the low Tg A solvent-based pressure-sensitive adhesive containing "(meth) acrylic block copolymer A" as a (meth) acrylic block copolymer having a segment, a high temperature region tanδ peak, and a low temperature region tanδ peak, and the (meth) acrylic block copolymer A. The composition may be referred to as "solvent type pressure-sensitive adhesive composition A".

The “segment” in the high Tg segment and the low Tg segment refers to a partial structure constituting each block unit of the (meth) acrylic block copolymer A.

The structure of the (meth) acrylic block copolymer A may be a linear block copolymer, a branched (star) block copolymer, or a mixture thereof. The structure of such a block copolymer may be appropriately selected according to the required physical properties of the block copolymer, but from the viewpoint of cost and ease of manufacture, it is preferably a linear block copolymer. The linear block copolymer may have any structure (arrangement), but from the viewpoint of the physical properties of the linear block copolymer or the physical properties of the solvent-type pressure-sensitive adhesive composition A, (AB) _n- type, ( _{AB) It is preferable that it is a block copolymer having at least one structure selected from the group consisting of n-} A type (n is an integer of 1 or more, for example, an integer of 1 to 3). In these structures, A and B mean segments composed of different monomer compositions. In the present specification, the segment represented by A constituting the linear block copolymer may be referred to as "A segment", and the segment represented by B may be referred to as "B segment".

Among these, AB type diblock copolymers represented by AB and ABA type triblock copolymers represented by ABA are selected from the viewpoints of ease of production, physical properties of the solvent-based pressure-sensitive adhesive composition A, and the like. Preferably, more preferably, it is an ABA type triblock copolymer. In ABA-type triblock copolymers, the cross-linking structure between block copolymers becomes higher due to pseudo-crosslinking between A segments at both ends, the cohesive force of block copolymers is improved, and higher adhesion (adhesive force) is exhibited. It is thought that it can be done. In the ABA type triblock copolymer, the two A segments located at both ends may be the same or different from each other.

When the (meth) acrylic block copolymer A is an ABA type triblock copolymer, at least one is a high Tg segment and at least one is a low Tg segment in two A segments and one B segment (three in total). It can be a segment. From the viewpoint of ease of production, physical properties of the solvent-based pressure-sensitive adhesive composition A, and the like, an ABA-type triblock copolymer in which the A segment is the high Tg segment and the B segment is the low Tg segment is preferable. In that case, an ABA-type triblock copolymer in which at least one of the two A segments is a high Tg segment and the B segment is a low Tg segment is preferred, and both of the two A segments are high Tg segments and the B segment. ABA-type triblock copolymers having a low Tg segment are more preferable.

As described above, the glass transition temperature (Tg) of the high Tg segment constituting the (meth) acrylic block copolymer A is 0 ° C. or higher and 100 ° C. or lower. When the Tg of the high Tg segment is in this range, the storage elastic modulus of the solvent-type pressure-sensitive adhesive composition A at room temperature (25 ° C.) can be easily controlled to be high, and the solvent-type pressure-sensitive adhesive composition A is hard and has excellent workability, and in a region exceeding 50 ° C. The storage elastic modulus tends to be significantly reduced, resulting in a highly fluid pressure-sensitive adhesive composition. From the viewpoint of improving the processability of the solvent-type pressure-sensitive adhesive composition A at room temperature (25 ° C.), the Tg of the high Tg segment is preferably 4 ° C. or higher, more preferably 6 ° C. or higher, further preferably 8 ° C. or higher. 10 ° C. or higher is even more preferable, and 12 ° C. or higher is particularly preferable. On the other hand, the Tg of the high Tg segment is 90 ° C. or lower from the viewpoint that the storage elastic modulus (G') of the solvent-type pressure-sensitive adhesive composition A is remarkably lowered in the region exceeding 50 ° C. and tends to have high fluidity. Preferably, 85 ° C. or lower is more preferable, 60 ° C. or lower is further preferable, 50 ° C. or lower is even more preferable, and 35 ° C. or lower is particularly preferable.

As described above, the Tg of the low Tg segment constituting the (meth) acrylic block copolymer A is −100 ° C. or higher and lower than 0 ° C. When the glass Tg of the low Tg segment is in this range, only the low Tg segment is fluidized at room temperature (25 ° C.), and an appropriate adhesive force is applied to the solvent-type pressure-sensitive adhesive composition A while ensuring processability. It tends to be granted. The Tg of the low Tg segment is preferably −95 ° C. or higher, more preferably −90 ° C. or higher, from the viewpoint that the storage elastic modulus of the solvent-type pressure-sensitive adhesive composition A does not easily decrease at room temperature (25 ° C.) and the processability can be improved. It is preferable, and more preferably −80 ° C. or higher. On the other hand, the Tg of the low Tg segment is preferably −5 ° C. or lower, more preferably −10 ° C. or lower, from the viewpoint of improving the appropriate adhesive strength and processability of the solvent-type pressure-sensitive adhesive composition A at room temperature (25 ° C.). Preferably, it is more preferably −20 ° C. or lower, even more preferably −30 ° C. or lower, and particularly preferably −40 ° C. or lower.

The difference between the Tg of the high Tg segment and the Tg of the low Tg segment (Tg of the high Tg segment-Tg of the low Tg segment) constituting the (meth) acrylic block copolymer A is not particularly limited, but is the same as that of the solvent-type pressure-sensitive adhesive composition A. From the viewpoint that the storage elastic modulus at room temperature (25 ° C.) is high and easy to control, it is hard and excellent in workability, and the storage elastic modulus is remarkably lowered in the region exceeding 50 ° C. to obtain a highly fluid pressure-sensitive adhesive composition. Therefore, it is preferably 30 ° C. or higher, more preferably 35 ° C. or higher, more preferably 40 ° C. or higher, more preferably 45 ° C. or higher, still more preferably 50 ° C. or higher, particularly preferably 55 ° C. or higher, and preferably 120 ° C. or lower. , More preferably 115 ° C. or lower, more preferably 110 ° C. or lower, more preferably 105 ° C. or lower, still more preferably 100 ° C. or lower, and particularly preferably 95 ° C. or lower.

The glass transition temperature (Tg) of the high Tg segment and the low Tg segment constituting the (meth) acrylic block copolymer A is a calculated glass transition temperature calculated from the following Fox formula. This calculated glass transition temperature is calculated based on the type and amount of each monomer component constituting the high Tg segment or the low Tg segment of the (meth) acrylic block copolymer A, and therefore the monomer component of each segment. It can be adjusted by selecting the type and amount of the above.

The calculated glass transition temperature (calculated Tg) can be calculated from the following Fox equation [1].
1 / Calculation Tg = W1 / Tg (1) + W2 / Tg (2) + ... + Wn / Tg (n) [1]
Here, W1, W2, ... Wn are the respective weight fractions (% by weight) of the monomer component (1), the monomer component (2), ... the monomer component (n) constituting the copolymer with respect to all the monomer components. ), And Tg (1), Tg (2), ... Tg (n) is a glass transition of the homopolymer of the monomer component (1), the monomer component (2), ... Represents temperature (unit is absolute temperature: K).
The glass transition temperature of homopolymers is known from various documents and catalogs, and is described in, for example, J. Brandup, EH Immergut, EA Grulke: Polymer Handbook: JOHNWILEY & SONS, INC. For monomers for which there are no numerical values in various documents, values measured by general thermal analysis, for example, differential thermal analysis, dynamic viscoelasticity measurement method, or the like can be adopted.

As described above, the temperature region in which the high temperature region tan δ peak of the (meth) acrylic block copolymer A appears is 0 ° C. or higher (for example, 0 ° C. or higher and 100 ° C. or lower). When the tan δ peak in the high temperature region is in this temperature range, the storage elastic modulus of the solvent-type pressure-sensitive adhesive composition A at room temperature (25 ° C.) can be easily controlled to be high, and it is hard and excellent in workability, and in the region exceeding 50 ° C. The storage elastic modulus tends to be significantly reduced, resulting in a highly fluid pressure-sensitive adhesive composition. From the viewpoint of improving the processability of the solvent-type pressure-sensitive adhesive composition A at room temperature (25 ° C.), the temperature at which the tanδ peak in the high temperature region appears is preferably 3 ° C. or higher, more preferably 6 ° C. or higher, and further 9 ° C. or higher. Preferably, 12 ° C. or higher is even more preferable, and 15 ° C. or higher is particularly preferable. On the other hand, the temperature at which the tan δ peak in the high temperature region appears is 90 ° C. from the viewpoint that the storage elastic modulus (G') of the solvent-type pressure-sensitive adhesive composition A is remarkably lowered in the region exceeding 50 ° C. and tends to have high fluidity. The following is preferable, 80 ° C. or lower is more preferable, 70 ° C. or lower is further preferable, 65 ° C. or lower is further preferable, and 60 ° C. or lower is particularly preferable.

The temperature region in which the low temperature region tan δ peak of the (meth) acrylic block copolymer A appears is less than 0 ° C. (for example, −100 ° C. or higher and lower than 0 ° C.) as described above. Since the tan δ peak in the low temperature region is in this temperature range, only the low Tg segment is fluidized at room temperature (25 ° C.), and an appropriate adhesive force is imparted to the solvent-type pressure-sensitive adhesive composition A while ensuring processability. There is a tendency to be able to do it. From the viewpoint that the storage elastic modulus of the solvent-type pressure-sensitive adhesive composition A does not easily decrease at room temperature (25 ° C.) and the processability can be improved, the temperature at which the tanδ peak in the low temperature region appears is preferably −95 ° C. or higher, preferably −90 ° C. The above is more preferable, −80 ° C. or higher is further preferable, and −70 ° C. or higher is further preferable. On the other hand, from the viewpoint of improving the appropriate adhesive strength and processability of the solvent-type pressure-sensitive adhesive composition A at room temperature (25 ° C.), the temperature at which the tanδ peak in the low temperature region appears is preferably −5 ° C. or lower, preferably −10 ° C. or lower. Is more preferable, −20 ° C. or lower is further preferable, −30 ° C. or lower is even more preferable, and −40 ° C. or lower is particularly preferable.

The maximum value of the tan δ peak in the high temperature region is not particularly limited, but is preferably 0.5 to 3.0. When the maximum value of the tan δ peak in the high temperature region is in this range, it is preferable in that excellent processability and shape stability of the (meth) acrylic block copolymer A can be realized. The maximum value of the tan δ peak in the high temperature region is preferably 0.6 or more, more preferably 0.7 or more, in that excellent workability can be realized. Further, the maximum value of the tan δ peak in the high temperature region is preferably 2.5 or less, more preferably 2.2 or less, from the viewpoint that dents are unlikely to occur.

The maximum value of the tan δ peak in the low temperature region is not particularly limited, but is preferably 0.1 to 2.0. When the maximum value of the tan δ peak in the low temperature region is in this range, it is preferable in that excellent processability and shape stability of the (meth) acrylic block copolymer A can be realized. The maximum value of the tan δ peak in the high temperature region is preferably 0.2 or more, more preferably 0.3 or more, in that excellent workability can be realized. Further, the maximum value of the tan δ peak in the low temperature region is preferably 1.5 or less, more preferably 1 or less, from the viewpoint that dents are unlikely to occur.

The high temperature region tan δ peak and the low temperature region tan δ peak, and the temperature and maximum value at which they appear are measured by dynamic viscoelasticity measurement.

The (meth) acrylic block copolymer A is composed of a plurality of segments (including a high Tg segment and a low Tg segment) obtained by polymerizing a monomer component, and the monomer component has a (meth) acryloyl group in the molecule. It contains a monomer (acrylic monomer) having.
The (meth) acrylic block copolymer A or each segment thereof preferably contains an acrylic monomer in an amount of 70% by weight or more, more preferably 80% by weight or more, and 90% by weight, based on the total amount (100% by weight) of the monomer components. It is particularly preferable to contain% or more.

Examples of the acrylic monomer constituting the (meth) acrylic block copolymer A or each segment thereof (including a high Tg segment and a low Tg segment) include an acrylic acid alkyl ester having a linear or branched alkyl group, and an acrylic acid alkyl ester having a linear or branched alkyl group. / Or, a monomer component derived from a methacrylic acid alkyl ester having a linear or branched alkyl group is contained as the main monomer unit having the largest weight ratio.

The (meth) acrylic acid alkyl ester having a linear or branched alkyl group for forming a segment of the (meth) acrylic block copolymer A is a (meth) acrylic acid having the above-mentioned chain alkyl group. Specific examples of alkyl esters can be given. As the (meth) acrylic acid alkyl ester for the segment, one kind of (meth) acrylic acid alkyl ester may be used, or two or more kinds of (meth) acrylic acid alkyl esters may be used. The (meth) acrylic acid alkyl ester for the segment is preferably methyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate, t-butyl acrylate, hexyl acrylate, heptyl acrylate, acrylic. At least one selected from the group consisting of octyl acid acid and isononyl acrylate is used.

The segment of the (meth) acrylic block copolymer A may contain a monomer unit derived from an alicyclic monomer. Examples of the alicyclic monomer for forming the monomer unit of the segment include specific examples of the (meth) acrylic acid alkyl ester having the alicyclic alkyl group described above. The alicyclic alkyl group may have a substituent. Examples of the substituent include a halogen atom (eg, fluorine atom, chlorine atom, bromine atom, iodine atom) and a linear or branched alkyl group having 1 to 6 carbon atoms (eg, methyl group, ethyl group, n-propyl). Group, isopropyl group, etc.) and the like. The number of the substituents is not particularly limited and can be appropriately selected from 1 to 6. When there are two or more substituents, the two or more substituents may be the same or different. As the alicyclic monomer for the segment, one kind of alicyclic monomer may be used, or two or more kinds of alicyclic monomers may be used. The alicyclic monomer for the segment is preferably a cyclo having 4 to 10 carbon atoms which may have a substituent (eg, a linear or branched alkyl group having 1 to 6 carbon atoms). It is a (meth) acrylic acid cycloalkyl ester having an alkyl group, and more preferably at least one selected from the group consisting of cyclohexyl acrylate and 3,3,5-trimethylcyclohexyl (meth) acrylic acid is used.

The segment of the (meth) acrylic block copolymer A may contain a monomer unit derived from a hydroxyl group-containing monomer. The hydroxyl group-containing monomer is a monomer having at least one hydroxyl group in the monomer unit. When the segment in the (meth) acrylic block copolymer A contains a hydroxyl group-containing monomer unit, it is easy to obtain adhesiveness and appropriate cohesive force in the solvent-type pressure-sensitive adhesive composition A.

Specific examples of the above-mentioned hydroxyl group-containing monomer can be mentioned as the hydroxyl group-containing monomer for forming the monomer unit of the segment. As the hydroxyl group-containing monomer for the segment, one type of hydroxyl group-containing monomer may be used, or two or more types of hydroxyl group-containing monomers may be used. The hydroxyl group-containing monomer for the segment is preferably a hydroxyl group-containing (meth) acrylic acid ester, more preferably 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, and methacrylic acid. At least one selected from the group consisting of 2-hydroxypropyl, 4-hydroxybutyl acrylate, and 4-hydroxybutyl methacrylate is used.

The segment of the (meth) acrylic block copolymer A may contain a monomer unit derived from a nitrogen atom-containing monomer. A nitrogen atom-containing monomer is a monomer that will have at least one nitrogen atom in the monomer unit. When the segment of the (meth) acrylic block copolymer A contains a nitrogen atom-containing monomer unit, it is easy to obtain hardness and good adhesive reliability in the solvent-based pressure-sensitive adhesive composition A.

Specific examples of the above-mentioned nitrogen atom-containing monomer can be mentioned as examples of the nitrogen atom-containing monomer for forming the segment. As the nitrogen atom-containing monomer for the acrylic polymer, one kind of nitrogen atom-containing monomer may be used, or two or more kinds of nitrogen atom-containing monomers may be used. As the nitrogen atom-containing monomer for the segment, N-vinyl-2-pyrrolidone is preferably used.

The segment of the (meth) acrylic block copolymer A may contain a monomer unit derived from a carboxy group-containing monomer. The carboxy group-containing monomer is a monomer having at least one carboxy group in the monomer unit. When the segment of the (meth) acrylic block copolymer A contains a carboxy group-containing monomer unit, good adhesive reliability may be obtained in the solvent-based pressure-sensitive adhesive composition A.

Specific examples of the above-mentioned carboxy group-containing monomer can be mentioned as examples of the carboxy group-containing monomer for forming the monomer unit of the segment. As the carboxy group-containing monomer for the segment, one kind of carboxy group-containing monomer may be used, or two or more kinds of carboxy group-containing monomers may be used. Acrylic acid is preferably used as the carboxy group-containing monomer for the segment.

Further, examples of the monomer unit for forming the segment include the above-mentioned other monomers. The content of other monomers in the monomer unit constituting the segment of the (meth) acrylic block copolymer A is not particularly limited as long as it is 30% by weight or less with respect to the total amount of the monomer components (100% by weight), and the present invention. It is appropriately selected within the range that does not impair the effect of.

As the monomer component constituting the high Tg segment of the (meth) acrylic block copolymer A, it is easy to control the Tg of the high Tg segment within a predetermined range, and it is possible to impart desired physical properties to the (meth) acrylic block copolymer A. From the viewpoint, a (meth) acrylic acid alkyl ester having a linear alkyl group having 1 to 3 carbon atoms (hereinafter, may be referred to as _{"(meth) acrylic acid C 1-3 linear alkyl ester".} ), (Meta) acrylic acid alkyl ester having a branched alkyl group having 3 or 4 carbon atoms (hereinafter, _{may be referred to as "(meth) acrylic acid C 3-4} branched chain alkyl ester"). And at least one selected from the group consisting of an alicyclic monomer is preferably contained. Since homopolymers of these monomers have a relatively high Tg, it is easy to control the Tg of the high Tg segment within a predetermined range of the present invention by containing a monomer selected from these as a monomer component constituting the high Tg segment.

The alicyclic monomer has a cycloalkyl group having 4 to 10 carbon atoms which may have a substituent (eg, a linear or branched alkyl group having 1 to 6 carbon atoms) (meth). ) Acrylic acid cycloalkyl ester is preferable, and an acrylic having a cycloalkyl group having 4 to 10 carbon atoms, which may have a substituent (eg, a linear or branched alkyl group having 1 to 6 carbon atoms). Acid cycloalkyl esters are more preferred, and cyclohexyl acrylate (homopolymer Tg: 15 ° C.) and (meth) acrylic acid 3,3,5-trimethylcyclohexyl (homopolymer Tg: 52 ° C.) are particularly preferred.

When the alicyclic monomer is contained as the monomer component constituting the high Tg segment, the content of the alicyclic monomer with respect to the total amount (100% by weight) of the monomer component makes it easy to control the Tg of the high Tg segment within a predetermined range. From the viewpoint of imparting desired physical properties to the (meth) acrylic block copolymer A, it is preferably 10% by weight or more (for example, 10 to 100% by weight), more preferably 20% by weight or more, and more preferably 30% by weight or more. , More preferably 30% by weight or more, more preferably 40% by weight or more, more preferably 50% by weight or more, more preferably 60% by weight or more, more preferably 70% by weight or more, more preferably 80% by weight or more, more. It is preferably 80% by weight or more, more preferably 90% by weight or more, and particularly preferably 95% by weight or more.

As the (meth) acrylic acid C _1-3 linear alkyl ester, acrylic acid C _1-3 linear alkyl ester is preferable, and methyl acrylate (tg of homopolymer: 8 ° C.) is particularly preferable.
As the (meth) acrylic acid C _3-4 branched chain alkyl ester, acrylic acid C _3-4 branched chain alkyl ester is preferable, and t-butyl acrylate (tg of homopolymer: 35 ° C.) is particularly preferable.

_{When (meth) acrylic acid C 1-3} linear alkyl ester and / or (meth) acrylic acid C _3-4 branched chain alkyl ester is contained as a monomer component constituting the high Tg segment, (meth) acrylic acid The _{content of C 1-3} linear alkyl ester and / or (meth) acrylic acid C _3-4 branched chain alkyl ester with respect to the total amount (100% by weight) of the monomer components is such that Tg of the high Tg segment is within a predetermined range. From the viewpoint of being easy to control and imparting desired physical properties to the (meth) acrylic block copolymer A, it is preferably 10% by weight or more (for example, 10 to 100% by weight), more preferably 20% by weight or more, and more preferably. 30% by weight or more, more preferably 30% by weight or more, more preferably 40% by weight or more, more preferably 50% by weight or more, more preferably 60% by weight or more, more preferably 70% by weight or more, more preferably 80% by weight. % Or more, more preferably 80% by weight or more, still more preferably 90% by weight or more, and particularly preferably 95% by weight or more.

As the monomer component constituting the low Tg segment of the (meth) acrylic block copolymer A, it is easy to control the Tg of the low Tg segment within a predetermined range, and it is possible to impart desired physical properties to the (meth) acrylic block copolymer A. From the viewpoint, a (meth) acrylic acid alkyl ester having a linear or branched alkyl group having 4 to 18 carbon atoms (hereinafter, may be referred to as _{"(meth) acrylic acid C 4-18 alkyl ester".} ) And at least one selected from the group consisting of hydroxyl group-containing monomers. That is, since the homopolymer of the (meth) acrylic acid C _4-18 alkyl ester has a relatively low Tg, by containing this as a monomer component constituting the low Tg segment, the Tg of the low Tg segment is defined in the present invention. Easy to control within the range of. On the other hand, the hydroxyl group-containing monomer also has a relatively low Tg, and the (meth) acrylic block copolymer A can easily obtain adhesiveness and appropriate cohesive force. _{Therefore, it is more preferable to contain both the (meth) acrylic acid C 4-18} alkyl ester and the hydroxyl group-containing monomer as the monomer component constituting the low Tg segment of the (meth) acrylic block copolymer A.

As the (meth) acrylic acid C _4-18 alkyl ester, acrylic acid C _4-18 alkyl ester is preferable, and butyl acrylate (Tg of homopolymer: -55 ° C.) and 2-ethylhexyl acrylate (Tg of homopolymer). : -70 ° C), n-hexyl acrylate (Tg of homopolymer: -57 ° C), n-octyl acrylate (Tg of homopolymer: -65 ° C), isononyl acrylate (Tg of homopolymer: -58 ° C) ) Is particularly preferable.

_{When the (meth) acrylic acid C 4-18} alkyl ester is contained as the monomer component constituting the low Tg segment, the content of the (meth) acrylic acid C _4-18 alkyl ester with respect to the total amount (100% by weight) of the monomer component is From the viewpoint that the Tg of the low Tg segment can be easily controlled within a predetermined range and the desired physical properties can be imparted to the (meth) acrylic block copolymer A, it is preferably 10% by weight or more (for example, 10 to 100% by weight). It is preferably 20% by weight or more, more preferably 30% by weight or more, more preferably 30% by weight or more, more preferably 40% by weight or more, more preferably 50% by weight or more, more preferably 60% by weight or more, more preferably. It is 70% by weight or more, more preferably 80% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight or more, and particularly preferably 95% by weight or more.

As the hydroxyl group-containing monomer, a hydroxyl group-containing (meth) acrylic acid alkyl ester is preferable, and 4-hydroxybutyl acrylate (Tg of homopolymer: −65 ° C.) and 2-hydroxyethyl acrylate (Tg of homopolymer: −15 ° C.) are preferable. ℃) is particularly preferable.

When a hydroxyl group-containing monomer is contained as a monomer component constituting the low Tg segment, the content of the hydroxyl group-containing monomer with respect to the total amount (100% by weight) of the monomer component makes it easy to control the Tg of the low Tg segment within a predetermined range (meth). ) From the viewpoint of imparting desired physical properties to the acrylic block copolymer A, it is preferably 1% by weight or more, more preferably 1.5% by weight or more, more preferably 2% by weight or more, still more preferably 2.5% by weight. As mentioned above, it is particularly preferably 3% by weight or more. On the other hand, the content of the hydroxyl group-containing monomer with respect to the total amount (100% by weight) of the monomer components is preferably 50% by weight or less, more preferably 40% by weight or less, more preferably 30% by weight or less, still more preferably 20% by weight or less. It is more preferably 10% by weight or less, and particularly preferably 5% by weight or less.

_{When both the (meth) acrylic acid C 4-18} alkyl ester and the hydroxyl group-containing monomer are contained as the monomer components constituting the low Tg segment of the (meth) acrylic block copolymer A, the hydroxyl group-containing monomer and the (meth) acrylic acid The ratio of the C _4-18 alkyl ester (hydroxyl-containing monomer / (meth) acrylic acid C _4-18 alkyl ester) is not particularly limited, but the lower limit is preferably 1/99, more preferably 1.5 / 98. 5, more preferably 2/98, still more preferably 2.5 / 97.5, particularly preferably 3/97, while the upper limit is 50/50, more preferably 40/60, more preferably 30/97. 70, more preferably 20/80.

The (meth) acrylic block copolymer A can be produced by the living radical polymerization method of the above-mentioned monomer components. The living radical polymerization method maintains the simplicity and versatility of the conventional radical polymerization method, but is less likely to cause a termination reaction or chain transfer, and grows without deactivating the growth end. Therefore, the molecular weight distribution is precisely controlled and uniform. It is preferable in that it is easy to produce a polymer having a suitable composition.

In the living radical polymerization method, the high Tg segment may be produced first and the monomer of the low Tg segment may be polymerized on the high Tg segment; the low Tg segment may be produced first and the monomer of the high Tg segment may be produced on the low Tg segment. May be polymerized.

When the (meth) acrylic block copolymer A is an ABA-type triblock copolymer, it is preferable to produce the A segment first and polymerize the B segment monomer to the A segment from the viewpoint of ease of production.

As the living radical polymerization method, a known method can be used without particular limitation, and a method using a transition metal catalyst (ATRP method) depending on the method for stabilizing the polymerization growth end; reversible addition of a sulfur system. There are methods such as a method using a cleavage chain transfer agent (RAFT agent) (RAFT method); a method using an organic tellurium compound (TERP method). Among these methods, it is preferable to use the RAFT method from the viewpoints of the variety of monomers that can be used, the ease of controlling the molecular weight, and the fact that the metal does not remain in the solvent-type pressure-sensitive adhesive composition.

In the RAFT method, a known method can be used without particular limitation. For example, a step 1 (first RAFT polymerization) in which a monomer component is polymerized using a RAFT agent to prepare a first segment (first RAFT polymerization). ) And the first segment obtained in step 1, a monomer component having a different monomer composition from that in step 1 is further added and polymerized, and the second segment is added to the first segment in step 2 (first segment). 2 RAFT polymerization). After the second RAFT polymerization, the RAFT polymerizations of the third, fourth ... May be carried out in the same manner as the second RAFT polymerization, and the segments of the third, fourth ... May be further added.

The steps 1 and 2 can be carried out by a known and commonly used method, for example, a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, and a polymerization method by irradiation with heat or active energy rays (thermal polymerization method, active energy ray polymerization). Method) and so on. Above all, the solution polymerization method is preferable in terms of transparency, water resistance, cost and the like. The polymerization is preferably carried out while avoiding contact with oxygen from the viewpoint of suppressing polymerization inhibition by oxygen. For example, it is preferable to carry out the polymerization in a nitrogen atmosphere.

When the (meth) acrylic block copolymer A is an ABA-type triblock copolymer, it is preferable to prepare the A segment in the step 1 and add the B segment to the obtained A segment in the step 2. .. In this case, the A segment is preferably a high Tg segment, and the B segment is preferably a low Tg segment.

As the RAFT agent, known ones can be used without particular limitation, and for example, compounds represented by the following formulas (1), (2), or formulas (3) (trithiocarbonate, dithioester, etc.) can be used. Dithiocarbonate) is preferred.

In formula (1), formula (2), or formula (3) [formulas (1) to (3)], R ^1a and R ^1b have the same or different hydrogen atoms, hydrocarbon groups, or cyano groups. show. R ^1c represents a hydrocarbon group which may have a cyano group. Examples ^{of the hydrocarbon groups as R 1a} , R ^1b , and R ^1c include hydrocarbon groups having 1 to 20 carbon atoms (straight, branched, or cyclic saturated or unsaturated hydrocarbon groups, etc.). Among them, hydrocarbon groups having 1 to 12 carbon atoms are preferable. Specific examples of the hydrocarbon group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a cyclohexyl group, a dodecyl group, an octadecyl group and the like. A linear, branched, or cyclic alkyl group having 1 to 12 carbon atoms; an aryl group having 6 to 12 carbon atoms such as a phenyl group; an arylalkyl group having a total carbon number of 7 to 10 such as a benzyl group and a phenethyl group, etc. Can be mentioned. Examples of the ^{hydrocarbon group having a cyano group as R 1c} include a group in which 1 to 3 hydrogen atoms of the above-mentioned hydrocarbon group are substituted with a cyano group.

In formulas (1) to (3), R ² represents a hydrocarbon group or a group in which a part of the hydrogen atom of the hydrocarbon group is substituted with a carboxyl group (for example, a carboxylalkyl group). Examples of the hydrocarbon group include hydrocarbon groups having 1 to 20 carbon atoms (straight chain, branched chain, cyclic saturated or unsaturated hydrocarbon groups, etc.), and among them, hydrocarbon groups having 1 to 12 carbon atoms. Hydrocarbon groups are preferred. Specific examples of the hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, cyclohexyl group, dodecyl group, octadecyl group and the like. Linear, branched, or cyclic alkyl groups having 1 to 12 carbon atoms; arylalkyl groups having a total carbon number of 7 to 10 such as benzyl group and phenethyl group can be mentioned.

In the RAFT method, the polymerization proceeds by reacting so that the raw material monomer is inserted between the sulfur atom in the RAFT agent represented by the formulas (1) to (3) and the methylene group adjacent to the sulfur atom.

Many of the RAFT agents are commercially available. Those that are not commercially available can be easily synthesized by known or conventional methods. In the present invention, one type of RAFT agent may be used alone, or two or more types may be used in combination.

RAFT agents include trithiocarbonates such as dibenzyltrithiocarbonate and S-cyanomethyl-S-dodecyltrithiocarbonate; cyanoethyl dithiopropionate, benzyl dithiopropionate, benzyl dithiobenzoate, acetoxyethyl dithiobenzoate and the like. Dithioesters; O-ethyl-S- (1-phenylethyl) dithiocarbonate, O-ethyl-S- (2-propoxyethyl) dithiocarbonate, O-ethyl-S- (1-cyano-1-methylethyl) Examples thereof include dithiocarbonates such as dithiocarbonate, of which trithiocarbonates are preferable, trithiocarbonates having a symmetrical structure in the formula (1) are more preferable, and dibenzyltrithiocarbonate and bis {4 are particularly preferable. -[Ethyl- (2-acetyloxyethyl) carbamoyl] benzyl} trithiocarbonate is preferred.

The step 1 can be performed by polymerizing the monomer components in the presence of a RAFT agent. The amount of the RAFT agent used in step 1 is usually 0.05 to 20 parts by weight, preferably 0.05 to 10 parts by weight, based on 100 parts by weight of the total amount of the monomer components. With such an amount used, the reaction can be easily controlled, and the weight average molecular weight of the obtained segment can be easily controlled.
The step 2 can be performed by adding a monomer component to the polymerization reaction mixture obtained in the step 1 and further polymerizing the mixture.

The RAFT method is preferably carried out in the presence of a polymerization initiator. Examples of the polymerization initiator include ordinary organic polymerization initiators, and specific examples thereof include peroxides and azo compounds. Among these, azo compounds are preferable. The polymerization initiator may be used alone or in combination of two or more.

Examples of the peroxide-based polymerization initiator include benzoyl peroxide and tert-butyl permalate.
Examples of the azo compound include 2,2'-azobisisobutyronitrile, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), and 2,2'-azobis (2-cyclopropyl). Propionitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile) , 2- (Carbamoylazo) isobutyronitrile, 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis ( N, N'-dimethyleneisobutylamidine), 2,2'-azobis (isobutylamide) dihydrate, 4,4'-azobis (4-cyanopentanoic acid), 2,2'-azobis (2-cyanopropanol), Examples thereof include dimethyl-2,2'-azobis (2-methylpropionate) and 2,2'-azobis [2-methyl-N- (2-hydroxyethyl) propionamide].

The amount of the polymerization initiator used is usually 0.001 to 2 parts by weight, preferably 0.002 to 1 part by weight, based on 100 parts by weight of the total amount of the monomer components. With such an amount, it is easy to control the weight average molecular weight of the obtained segment.

The RAFT method may be bulk polymerization that does not use a polymerization solvent, but it is preferable to use a polymerization solvent. Examples of the polymerization solvent include aromatic hydrocarbons such as benzene, toluene and xylene; aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane and n-octane; cyclopentane, cyclohexane, cycloheptane and cyclo. Alicyclic hydrocarbons such as octane; halogenated hydrocarbons such as chloroform, carbon tetrachloride, 1,2-dichloroethane, chlorobenzene; diethyl ether, diisopropyl ether, 1,2-dimethoxyethane, dibutyl ether, tetrahydrofuran, dioxane, anisole , Ethers such as phenylethyl ether and diphenyl ether; esters such as ethyl acetate, propyl acetate, butyl acetate and methyl propionate; ketones such as acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone and cyclohexanone; N, N-dimethylformamide, N , N-dimethylacetamide, amides such as N-methylpyrrolidone; nitriles such as acetonitrile and benzonitrile; sulfoxides such as dimethylsulfoxide and sulfolanes. The polymerization solvent may be used alone or in combination of two or more.

The amount of the polymerization solvent used is not particularly limited, and is, for example, 0.01 mL or more, more preferably 0.05 mL or more, still more preferably 0.1 mL or more, and 50 mL or less with respect to 1 g of the monomer component. It is preferably 10 mL or less, still more preferably 1 mL or less.

The reaction temperature in the RAFT method is usually 60 to 120 ° C., preferably 70 to 110 ° C., and is usually carried out in an atmosphere of an inert gas such as nitrogen gas. This reaction can be carried out under normal pressure, pressurization or reduced pressure, and is usually carried out at normal pressure. The reaction time is usually 1 to 20 hours, preferably 2 to 14 hours.

The polymerization reaction conditions of the RAFT method described above can be applied to step 1 and step 2, respectively.

After completion of the polymerization reaction, the target (meth) acrylic block copolymer A can be separated from the obtained reaction mixture by removing the solvent used, residual monomers and the like by ordinary separation and purification means.

When the high Tg segment or the low Tg segment of the (meth) acrylic block copolymer A is prepared in the step 1, the weight average molecular weight (Mw) of the high Tg segment or the low Tg segment is not particularly limited, but is preferably 10. It is 000 to 1,000,000, more preferably 50,000 to 500,000, and even more preferably 100,000 to 300,000. The fact that the Mw of the high Tg segment or the low Tg segment is within this range is suitable for the above-mentioned effect of the present invention.
The Mw is the sum of Mw when two or more high Tg segments or low Tg segments are present in the (meth) acrylic block copolymer A.

The weight average molecular weight (Mw) of the (meth) acrylic block copolymer A is not particularly limited, but is preferably 200,000 (200,000) or more, more preferably 300,000 to 5,000,000, and even more preferably. Is between 400,000 and 2,500,000. It is suitable for the above-mentioned effect of the present invention that the Mw of the (meth) acrylic block copolymer A is within this range.

The molecular weight distribution (Mw / Mn) of the (meth) acrylic block copolymer A is not particularly limited, but is preferably larger than 1, more preferably 1.5 or more, still more preferably 2 or more, and particularly preferably 2. It is 5 or more, preferably 5 or less, more preferably 4.5 or less, still more preferably 4 or less, and particularly preferably 3.5 or less.

The weight average molecular weight (Mw) and the molecular weight distribution (Mw / Mn) are measured by the GPC method.

The content of the high Tg segment in the (meth) acrylic block copolymer A is preferably 10% by weight or more, more preferably 20% by weight or more, still more preferably 20% by weight or more in 100% by weight of the entire (meth) acrylic block copolymer A. It is 25% by weight or more, particularly preferably 30% by weight or more, preferably 95% by weight or less, more preferably 90% by weight or less, still more preferably 85% by weight or less.

The content of the low Tg segment in the (meth) acrylic block copolymer A is preferably 5% by weight or more, more preferably 10% by weight or more, still more preferably 10% by weight or more in 100% by weight of the entire (meth) acrylic block copolymer A. It is 15% by weight or more, preferably 60% by weight or less, more preferably 50% by weight or less, still more preferably 40% by weight or less, and particularly preferably 30% by weight or less.

The content of each of the segments and their ratio can be calculated from the weight average molecular weight (Mw) of each segment or the (meth) acrylic block copolymer A obtained in each step of the RAFT method, and when each segment is formed. It can be controlled by the charging ratio of the monomers, the polymerization rate of each monomer, and the like.

The content of the (meth) acrylic block copolymer A in the solvent-based pressure-sensitive adhesive composition A is not particularly limited, but is excellent in processability at room temperature (25 ° C.) and excellent step absorption in a region exceeding 50 ° C. From the viewpoint of obtaining the above, the amount is preferably 50% by weight or more (for example, 50 to 100% by weight), more preferably 60% by weight, based on the total amount (total weight, 100% by weight) of the solvent-type pressure-sensitive adhesive composition A. As mentioned above, it is more preferably 80% by weight or more, and particularly preferably 90% by weight or more.

(solvent)
Since the polymer in the third form is a solid, the solvent-based pressure-sensitive adhesive composition is a solution in which the polymer is dissolved in an organic solvent. For example, a polymer solution can be obtained by solution-polymerizing the monomer components. A polymer solution may be prepared by dissolving a solid polymer in an organic solvent.

As the solvent, ethyl acetate, toluene and the like are generally used. The solution concentration is usually about 20 to 80% by weight.

Examples of the polymerization initiator when the monomer component is solution-polymerized include an azo-based initiator, a peroxide-based initiator, and a redox-based initiator that combines a peroxide and a reducing agent (for example, persulfate and sodium bisulfite). , A combination of peroxide and sodium ascorbate) and other thermal polymerization initiators are preferably used. The amount of the polymerization initiator used is not particularly limited, but is preferably about 0.005 to 5 parts by weight, more preferably about 0.02 to 3 parts by weight, based on 100 parts by weight of the total amount of the monomer components forming the polymer. preferable.

(Colorant)
The solvent-based pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer of the third form may contain a colorant. In particular, it is preferable that the solvent pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer 1 further contains a colorant. When the solvent-type pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer 1 contains a colorant, the permeability of the first pressure-sensitive adhesive layer 1 to visible light is lowered, and _{T 1 and T 2} are T _1. <Preferable for a configuration that satisfies _{T 2.} The first pressure-sensitive adhesive layer 1 having reduced transparency to visible light and imparted light-shielding property is used between the metal wiring layer 6 of the self-luminous display device (mini / micro LED display device) of the present embodiment and the LED chip. By sealing, reflection due to metal wiring or the like is prevented, color mixing between LED chips is prevented, and image contrast is improved.

The colorant may be a dye or a pigment as long as it can be dissolved or dispersed in the solvent-type pressure-sensitive adhesive composition. Dyes are preferable because low haze can be achieved even with a small amount of addition, and unlike pigments, they do not have sedimentation properties and can be easily distributed uniformly. In addition, pigments are also preferable because they have high color development even when added in a small amount. When a pigment is used as a colorant, it preferably has low or no conductivity. When a dye is used, it is preferably used in combination with an antioxidant or the like.

The colorant contained in the solvent-type pressure-sensitive adhesive composition in the third form includes an ultraviolet-absorbing colorant in addition to the ultraviolet-transmissive colorant described above for the first form.

Examples of the ultraviolet-transparent black pigment include "9050BLACK" and "UVBK-0001" manufactured by Tokushiki. Examples of the ultraviolet-absorbing black dye include "VALIFAST BLACK 3810" and "NUBIAN Black PA-2802" manufactured by Orient Chemical Industries. Examples of the ultraviolet-absorbing black pigment include carbon black and titanium black.

The content of the colorant in the solvent-type pressure-sensitive adhesive composition is, for example, about 0.01 to 20 parts by weight with respect to 100 parts by weight of the total amount of the monomers, and the type of colorant, the color tone of the pressure-sensitive adhesive layer, and light transmittance. It may be set appropriately according to the rate and the like. The colorant may be added to the composition as a solution or dispersion dissolved or dispersed in an appropriate solvent.

(Crosslinking agent)
The solvent-based pressure-sensitive adhesive composition of the third form may contain a cross-linking agent capable of cross-linking with the above polymer. When the solvent-based pressure-sensitive adhesive composition contains a (meth) acrylic block copolymer, the pressure-sensitive adhesive layer of the third form has sufficient shape stability and may not contain a cross-linking agent.

When the solvent-type pressure-sensitive adhesive composition contains a cross-linking agent in the third form, the cross-linking agent is the same as that described above for the second form, and an isocyanate-based cross-linking agent and an epoxy-based cross-linking agent are preferable.

When the solvent-type pressure-sensitive adhesive composition contains a cross-linking agent in the third embodiment, the content thereof is about 0.01 to 5 parts by weight with respect to 100 parts by weight of the polymer, and 0.05 parts by weight or more, 0. It may be 1 part by weight or more or 0.2 parts by weight or more, and may be 3 parts by weight or less, 2 parts by weight or less, or 1 part by weight or less.

(Other ingredients)
In addition to the above components, the solvent-based pressure-sensitive adhesive composition of the third form includes oligomers, tackifiers, silane coupling agents, chain transfer agents, plasticizers, softeners, deterioration inhibitors, fillers, antioxidants, and the like. It may contain a surfactant, an antistatic agent and the like.

<Optical laminate>
In the present embodiment, the optical laminate 10 can be prepared by laminating the first pressure-sensitive adhesive layer 1 and the second pressure-sensitive adhesive layer 2 on both sides of the first base material S, respectively. The order in which the first pressure-sensitive adhesive layer 1 and the second pressure-sensitive adhesive layer 2 are laminated on both sides of the first base material S is not particularly limited.

In the present embodiment, the optical laminates 20 to 22 have the optical laminate 10 on one side of the second base material 3 (the surface that has not been treated for antireflection and / or antiglare treatment). 2 It can be prepared by laminating the pressure-sensitive adhesive layer 2.
Further, the optical laminates 20 to 22 have the second adhesive layer 2 and the first on one surface of the second base material 3 (the surface not treated with the antireflection treatment and / or the antiglare treatment). It can also be produced by sequentially laminating the base material S and the first pressure-sensitive adhesive layer 1 in this order.

[First form]
The method of laminating the first adhesive layer 1 and the second adhesive layer 2 of the first form on the first base material S is not particularly limited, and for example, the photocurable pressure-sensitive adhesive composition is placed on a release film. It can be applied and molded on a sheet, photocured to prepare a sheet-shaped first pressure-sensitive adhesive layer 1 and a second pressure-sensitive adhesive layer 2, and then bonded to both sides of the first base material S, respectively. can.

A method of laminating the second adhesive layer 2 of the optical laminate 10 on one surface of the second base material 3 (the surface that has not been treated for antireflection and / or antiglare treatment), the second unit. The second pressure-sensitive adhesive layer 2, the first base material S, and the first pressure-sensitive adhesive layer 1 are applied to one side of the material 3 (the side that has not been treated for antireflection and / or antiglare treatment). The method of sequentially laminating in this order can also be performed by performing the same laminating.

The first form is obtained by applying the photocurable pressure-sensitive adhesive composition on a release film in a sheet form (layered form) and irradiating the coating film of the pressure-sensitive adhesive composition on the release film with ultraviolet rays to perform photo-curing. A first pressure-sensitive adhesive layer or a second pressure-sensitive adhesive layer is obtained. When photocuring, a release film is further attached to the surface of the coating film, and the photocurable pressure-sensitive adhesive composition is sandwiched between the two release films and irradiated with ultraviolet rays to inhibit polymerization by oxygen. It is preferable to prevent it. Prior to photo-curing, the sheet-shaped coating film may be heated for the purpose of removing the solvent or dispersion medium of the colorant. When removing the solvent or the like by heating, it is preferable to carry out before attaching the release film.

As the film base material of the release film, a film made of various resin materials is used. Resin materials include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyether sulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, and (meth) acrylic resins. Examples thereof include polyvinyl chloride-based resins, polyvinylidene chloride-based resins, polystyrene-based resins, polyvinyl alcohol-based resins, polyarylate-based resins, and polyphenylene sulfide-based resins. Among these, polyester resins such as polyethylene terephthalate are particularly preferable. The thickness of the film substrate is preferably 10 to 200 μm, more preferably 25 to 150 μm. Examples of the material of the release layer include a silicone-based release agent, a fluorine-based release agent, a long-chain alkyl-based release agent, a fatty acid amide-based release agent, and the like. The thickness of the release layer is generally about 10 to 2000 nm.

As a method of applying the adhesive composition on the release film, roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat , Lip coat, die coater and the like are used.

The thickness of the first pressure-sensitive adhesive layer 1 is not particularly limited, and the upper part (image display side) of the light-emitting element is the first base material S and the first base material S while sufficiently sealing the light-emitting elements arranged on the display panel described later. 2 It may be appropriately set so as to be covered with the pressure-sensitive adhesive layer 2. For example, the thickness of the first pressure-sensitive adhesive layer is 1.0 to 4.0 times, preferably 1.1 to 3.0 times, more preferably 1.2 to 2.5 times the height of the light emitting element. More preferably, it is adjusted to be 1.3 to 2.0 times. Specifically, the thickness of the first pressure-sensitive adhesive layer is, for example, about 10 to 300 μm, preferably 15 to 200 μm. Specifically, the thickness of the first pressure-sensitive adhesive layer may be 10 μm or more, 15 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, or 50 μm or more. Further, when the first pressure-sensitive adhesive layer contains an ultraviolet-transmissive colorant, the photocurable pressure-sensitive adhesive composition can be uniformly photo-cured in the thickness direction even when the thickness of the first pressure-sensitive adhesive layer is large. Is. The thickness of the first pressure-sensitive adhesive layer may be 300 μm or less, 250 μm or less, or 200 μm or less.

The thickness of the second pressure-sensitive adhesive layer 2 is not particularly limited, and may be appropriately set so as to sufficiently transmit light at the upper portion (image display side) of the light emitting element. Specifically, the thickness of the second pressure-sensitive adhesive layer is, for example, about 1 to 500 μm, more preferably 10 to 300 μm, and even more preferably 15 to 200 μm. Specifically, the thickness of the second pressure-sensitive adhesive layer may be 1 μm or more, 10 μm or more, 15 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, or 50 μm or more. The thickness of the second pressure-sensitive adhesive layer may be 400 μm or less, 300 μm or less, 250 μm or less, or 200 μm or less.

The ratio of the thickness of the second pressure-sensitive adhesive layer to the thickness of the first pressure-sensitive adhesive layer (thickness of the second pressure-sensitive adhesive layer / thickness of the first pressure-sensitive adhesive layer) is not particularly limited and is arranged on a display panel described later. The upper part (image display side) of the light emitting element may be appropriately set so as to be covered with the second adhesive layer while sufficiently sealing the light emitting element. Specifically, (thickness of the second pressure-sensitive adhesive layer / thickness of the first pressure-sensitive adhesive layer) is, for example, about 1.0 to 5.0, preferably 1.2 to 4.0, and more preferably 1.2 to 4.0. It may be 1.3 to 3.0.

By irradiating the photocurable pressure-sensitive adhesive composition coated in layers on the release film with ultraviolet rays, active species are generated from the photopolymerization initiator, the photopolymerizable compound is polymerized, and the polymerization rate is increased (unreacted). With the reduction of the monomer), the liquid photocurable pressure-sensitive adhesive composition becomes a solid (standard) pressure-sensitive adhesive layer. The light source for ultraviolet irradiation is not particularly limited as long as the photopolymerization initiator contained in the photocurable pressure-sensitive adhesive composition can irradiate light in a sensitive wavelength range, and an LED light source, a high-pressure mercury lamp, or the like. Ultra-high pressure mercury lamps, metal halide lamps, xenon lamps, etc. are used.

The integrated light amount of the irradiation light is, for example, about ^{100 to 5000 mJ / cm 2.} The polymerization rate (nonvolatile content) of the pressure-sensitive adhesive layer made of the photo-curable product of the photocurable pressure-sensitive adhesive composition is preferably 80% or more, more preferably 85% or more, still more preferably 90% or more. The polymerization rate may be 93% or more or 95% or more. In order to reduce the non-volatile content, the pressure-sensitive adhesive layer may be heated to remove volatile components such as residual monomers, unreacted polymerization initiators, and solvents.

When the release films are provided on both sides of the pressure-sensitive adhesive layer, the thickness of one release film and the thickness of the other release film may be the same or different. The peeling force when peeling the release film temporarily attached to one surface from the pressure-sensitive adhesive layer and the peeling force when peeling the release film temporarily attached to the other surface from the pressure-sensitive adhesive layer are the same but different. You may. When the peeling forces of the two are different, the peeling film (light peeling film) having a relatively small peeling force is first peeled from the first pressure-sensitive adhesive layer 1 and the second pressure-sensitive adhesive layer 2, respectively, to form the first base material S. By laminating both sides, the optical laminate 10 having the first adhesive layer and the second adhesive layer of the first form can be produced.

Further, the photocurable pressure-sensitive adhesive composition is applied to both surfaces of the first base material S, molded on a sheet, and then a release film is attached to the surface of the coating film and irradiated with ultraviolet rays. An optical laminate 10 having the first adhesive layer and the second adhesive layer of the first embodiment is provided in the same manner as above except that the first adhesive layer and the second adhesive layer are laminated on the base material S, respectively. It can also be made.

When the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer contains a colorant, it has light absorption in visible light. The visible light transmittance of the optical laminate of the first form is, for example, 80% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, or 5 It may be less than or equal to%.

In the first embodiment, the visible light transmittance T ₁ of the first pressure-sensitive adhesive layer is not particularly limited, but is, for example, 80% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less. , 20% or less or 10% or less. _{When the visible light transmittance T 1} of the first pressure-sensitive adhesive layer is 80% or less, it becomes easier to lower the transmittance than _{the visible light transmittance T 2} of the second pressure-sensitive adhesive layer. By sealing between the metal wiring of the light emitting display device and the light emitting element, it is possible to prevent reflection of the metal wiring or the like, prevent color mixing between the light emitting elements, and improve the contrast. Further, as described above, when the colorant absorption is less ultraviolet than the absorption of visible light on the first adhesive layer is used, the first adhesive layer, the average transmittance T _UV wavelength in the wavelength 330~400nm It is larger than the average transmittance T _VIS of 400 to 700 nm. _{The average transmittance T VIS} of the first pressure-sensitive adhesive layer at a wavelength of 400 to 700 nm is, for example, 80% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, 20% or less, or 10 It may be less than or equal to%. Average transmittance T _UV wavelength 330~400nm the first pressure-sensitive adhesive layer is preferably at least 5%, 10% or more, 15% or more, may be 20% or more or 25% or more. The difference T _UV -T _VIS between T _UV and T _VIS is more than 3%, 5% or more, or may be more than 8% or 10% or more.

In the first form, the visible light transmittance T ₂ of the second pressure-sensitive adhesive layer is not particularly limited, but is, for example, 85 to 100%, and may be 88% or more, 90% or more, or 92% or more. As described above, the luminous efficiency is improved by covering the upper part (image display side) of the light emitting element of the self-luminous display device with the second adhesive layer having high transparency.

In the first embodiment, the shear storage elastic modulus G'25 ° C. of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer at a temperature of 25 ° C. is, for example, about 10 to 1000 kPa, and is 30 kPa or more, 50 kPa or more, 70 kPa or more, or 100 kPa or more. It may be 700 kPa or less, 500 kPa or less, 300 kPa or less, or 200 kPa or less. The shear storage elastic modulus G'85 ° C. at a temperature of the pressure-sensitive adhesive layer at 85 ° C. is, for example, about 3 to 300 kPa, may be 5 kPa or more, 7 kPa or more, or 10 kPa or more, and is 200 kPa or less, 150 kPa or less, or 100 kPa. It may be as follows. When the shear storage elastic modulus of the pressure-sensitive adhesive layer is within the above range, both appropriate flexibility and adhesiveness can be achieved. The shear storage elastic modulus is a value measured by dynamic viscoelasticity measurement at a frequency of 1 Hz.

[Second form]
In the optical laminate 10 having the pressure-sensitive adhesive layer of the second form, the photocurable pressure-sensitive adhesive composition of the second form is applied onto a release film, and if necessary, the solvent is dried and removed to remove the first pressure-sensitive adhesive. It can be prepared by forming the layer 1 and the second pressure-sensitive adhesive layer 2 and attaching them to both sides of the first base material S, respectively.

Further, in the optical laminate 10 having the pressure-sensitive adhesive layer of the second form, the photocurable pressure-sensitive adhesive composition of the second form is applied to both surfaces of the first base material 3, and the solvent is dried and removed if necessary. It can also be prepared by.

The optical laminates 20 to 22 having the pressure-sensitive adhesive layer of the second form are optically laminated on one side of the second base material 3 (the surface not treated with antireflection treatment and / or antiglare treatment). It can be prepared by attaching the second pressure-sensitive adhesive layer 2 of the body 10.
Further, the optical laminates 20 to 22 having the pressure-sensitive adhesive layer of the second form are formed on one side of the second base material 3 (the surface not treated, if antireflection treatment and / or antiglare treatment is performed). It can also be prepared by sequentially laminating the second pressure-sensitive adhesive layer 2, the first base material S, and the first pressure-sensitive adhesive layer 1 in this order.

When the photocurable pressure-sensitive adhesive composition contains a solvent, it is preferable to dry the solvent after applying the pressure-sensitive adhesive composition. As the drying method, an appropriate method can be appropriately adopted depending on the purpose. The heating and drying temperature is preferably 40 ° C. to 200 ° C., more preferably 50 ° C. to 180 ° C., and particularly preferably 70 ° C. to 170 ° C. As the drying time, an appropriate time can be adopted as appropriate. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 15 minutes, and particularly preferably 10 seconds to 10 minutes.

After applying the photocurable pressure-sensitive adhesive composition, a crosslinked structure is introduced into the polymer by heating as necessary. The heating temperature and heating time may be appropriately set depending on the type of the cross-linking agent used, and are usually in the range of 20 ° C. to 160 ° C. for about 1 minute to 7 days. The heating for drying the solvent may also serve as the heating for crosslinking. The introduction of the crosslinked structure does not necessarily have to be accompanied by heating.

The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer of the second form have the same thickness (first pressure-sensitive adhesive layer and second pressure-sensitive adhesive layer) as the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer of the first form, respectively. Each thickness, the ratio of the thickness), the light transmittance, and the shear storage elastic modulus are preferable. Since the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer of the second form are not photocured, the photopolymerizable compound is contained in an unreacted state. That is, the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer of the second form are photocurable pressure-sensitive adhesives containing a polymer, a photopolymerizable compound, a photopolymerization initiator, and a colorant if necessary. It is a layer.

The optical laminate having the photocurable first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer of the second form is photo-cured by irradiating with ultraviolet rays after being bonded to a display panel described later. Can be done. The adhesive force between the optical laminate and the display panel can be changed by photocuring. For example, since the adhesive layer before photo-curing has high flexibility, it is possible to fill the uneven shape and steps formed by the light emitting elements arranged on the display panel, and after photo-curing, the adhesive force to the display panel. And adhesion reliability can be improved.

Ultraviolet rays are used as the active rays for photocuring the pressure-sensitive adhesive layer. Similar to the pressure-sensitive adhesive layer of the first form, when an ultraviolet-transmissive colorant is used, the transmittance of ultraviolet rays is higher than that of visible light. Curing inhibition can be suppressed.

The optical laminate having the first adhesive layer and / or the second adhesive layer of the first form and the second form containing the ultraviolet transmissive colorant has light absorption in visible light. It is desirable that the optical laminates of the first form and the second form have a maximum transmittance at 350 nm to 450 nm.

The visible light transmittance of the optical laminates of the first form and the second form is, for example, 80% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, 20% or less, 10 It may be% or less or 5% or less.

[Third form]
In the optical laminate 10 having the pressure-sensitive adhesive layer of the third form, the solvent-type pressure-sensitive adhesive composition of the third form is applied onto a release film, and if necessary, the solvent is dried and removed to remove the first pressure-sensitive adhesive layer. It can be prepared by forming the first and second pressure-sensitive adhesive layers and attaching them to both sides of the first base material S, respectively.

Further, in the optical laminate 10 having the pressure-sensitive adhesive layer of the third form, the solvent-type pressure-sensitive adhesive composition of the third form is applied to both surfaces of the first base material S, and the solvent is removed by drying if necessary. Therefore, it can also be prepared by forming the first pressure-sensitive adhesive layer 1 and the second pressure-sensitive adhesive layer.

The optical laminates 20 to 22 having the pressure-sensitive adhesive layer of the third form are optically laminated on one side of the second base material 3 (the surface not treated with antireflection treatment and / or antiglare treatment). It can be prepared by attaching the second pressure-sensitive adhesive layer 2 of the body 10.
Further, the optical laminates 20 to 22 having the pressure-sensitive adhesive layer of the third form are formed on one side of the second base material 3 (the surface not treated, if antireflection treatment and / or antiglare treatment is performed). It can also be prepared by sequentially laminating the second pressure-sensitive adhesive layer 2, the first base material S, and the first pressure-sensitive adhesive layer 1 in this order.

After applying the solvent-type pressure-sensitive adhesive composition, the solvent is dried. As the drying method, an appropriate method can be appropriately adopted depending on the purpose. The heating and drying temperature is preferably 40 ° C. to 200 ° C., more preferably 50 ° C. to 180 ° C., and particularly preferably 70 ° C. to 170 ° C. As the drying time, an appropriate time can be adopted as appropriate. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 15 minutes, and particularly preferably 10 seconds to 10 minutes.

After applying the solvent-type pressure-sensitive adhesive composition, heating may be performed if necessary. The heating temperature and heating time may be appropriately set depending on the type of the cross-linking agent used, and are usually in the range of 20 ° C. to 160 ° C. for about 1 minute to 7 days.

The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer of the third form have the same thickness as the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer of the first form (of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer, respectively). It is preferable to have each thickness (thickness, ratio of thickness), light transmittance, and shear storage elastic modulus.

Further, when the solvent-type pressure-sensitive adhesive composition contains (meth) acrylic block copolymer A, the storage elastic modulus of the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer (particularly, the first pressure-sensitive adhesive layer) at 25 ° C. (G'25) is not particularly limited, but is preferably 1 MPa or more, more preferably 1.5 MPa or more, more preferably 2 MPa or more, more preferably 2.5 MPa or more, and more, from the viewpoint of improving workability at room temperature. It is preferably 3 MPa or more, and from the viewpoint of improving the adhesive reliability at room temperature, it is preferably 50 MPa or less, more preferably 45 MPa or less, more preferably 40 MPa or less, more preferably 35 MPa or less, and even more preferably 30 MPa or less.

The storage elasticity (G) of the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer (particularly, the first pressure-sensitive adhesive layer) at 50 ° C. when the solvent-based pressure-sensitive adhesive composition contains (meth) acrylic block copolymer A. '50) is not particularly limited, but is preferably 0.5 MPa or less, more preferably 0.45 MPa or less, more preferably 0.4 MPa or less, more preferably 0.4 MPa or less, from the viewpoint of improving the step absorption in the region exceeding 50 ° C. Is 0.35 MPa or more, more preferably 0.3 MPa or less, and from the viewpoint of improving the handleability of the region exceeding 50 ° C., 0.0001 MPa or more is preferable, 0.0005 MPa or more, more preferably 0. It is 001 MPa or more, more preferably 0.005 MPa or more, and more preferably 0.01 MPa or more.

The storage elastic modulus of the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer (particularly, the first pressure-sensitive adhesive layer) at 25 ° C. when the solvent-based pressure-sensitive adhesive composition contains (meth) acrylic block copolymer A and 50. The ratio of storage elastic modulus at ° C. (G'25 / G'50) is not particularly limited, but is 3 or more from the viewpoint of improving workability at room temperature and improving step absorption in a region exceeding 50 ° C. It is preferably 5 or more, more preferably 10 or more, still more preferably 15 or more, particularly preferably 20 or more, and from the viewpoint of adhesive reliability, handleability, etc., 100 or less is preferable, and 95 or less is more preferable. It is more preferably 90 or less, still more preferably 85 or less, and particularly preferably 80 or less.

The storage elastic modulus at 25 ° C. (G'25), the storage elastic modulus at 50 ° C. (G'25), and their ratio (G'25 / G'50) are measured by dynamic viscoelasticity measurement. Is to be done.

The optical laminate having the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer of the third form containing the colorant has light absorption in visible light.

The visible light transmittance of the optical laminate of the third form is, for example, 80% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, 20% or less, 10% or less, or 5 It may be less than or equal to%.

In the optical laminate 10 of the present embodiment (first to third forms), a release film may be provided on each of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer until use. Further, in the optical laminates 20 to 22 of the present embodiment (first to third forms), release films may be provided on the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer, respectively, until use.

Further, in the optical laminate of the present embodiment (first to third embodiments), a surface protective film may be laminated on the surface 3a of the second base material 3. The surface protective film is suitable for preventing the adhesion of scratches and stains during the manufacture, transportation, and shipment of the optical laminate and the optical products containing the optical laminate.

The optical laminate (first to third forms) of the present embodiment includes a first pressure-sensitive adhesive layer 1, a second pressure-sensitive adhesive layer 2, a first base material S, a second base material 3, a release film, and a surface protective film. In addition to the above, other layers, for example, base materials other than the first base material and the second base material 3, the first pressure-sensitive adhesive layer 1 and the second pressure-sensitive adhesive layer 2, other than the above, as long as the effects of the present invention are not impaired. A pressure-sensitive adhesive layer, an intermediate layer, an undercoat layer, and the like may be provided on the surface or between arbitrary layers.

<Self-luminous display device>
In the self-luminous display device according to the second aspect of the present invention, a small number of light emitting elements are arranged on a wiring substrate, and each light emitting element is selectively emitted by a light emitting control means connected thereto. , A display device capable of directly displaying visual information such as characters, images, and moving images on a display screen by blinking each light emitting element. Examples of the self-luminous display device include a mini / micro LED display device and an organic EL (electroluminescence) display device. The optical laminate according to the first aspect of the present invention is particularly suitably used for manufacturing a mini / micro LED display device.

5 to 7 are schematic views (cross-sectional views) showing an embodiment of a self-luminous display device (mini / micro LED display device) according to the second aspect of the present invention. The mini / micro LED display device 30 according to the present embodiment includes a display panel in which a plurality of LEDs 7 are arranged on one side of a substrate 5, and an optical laminate 20. The surface on the display panel on which the LED chips 7 are arranged is laminated with the first adhesive layer 1 of the optical laminate 20. In the mini / micro LED display device 31, the surface 3a on which the second adhesive layer 2 of the second base material 3 is not laminated is subjected to antireflection treatment and / or antiglare treatment 4. In the mini / micro LED display device 32, an anti-glare layer 4a is formed as an anti-glare treatment on the surface 3a on which the second adhesive layer 2 of the second base material 3 is not laminated.

In the present embodiment, a metal wiring layer 6 for sending a light emission control signal to each LED chip 7 is laminated on the substrate 5 of the display panel. The LED chips 7 that emit light of each color of red (R), green (G), and blue (B) are alternately arranged on the substrate 5 of the display panel via the metal wiring layer 6. The metal wiring layer 6 is formed of a metal such as copper, and reflects the light emitted from each LED chip 6 to reduce the visibility of the image. Further, the light emitted from each LED chip 7 of each color of RGB is mixed, and the contrast is lowered.

In the mini / micro LED display device of the present embodiment, the first adhesive layer 1 seals between the LED chips 7 arranged on the display panel and the metal wiring layer 6. Since the visible light transmittance of the first pressure-sensitive adhesive layer 1 is lower than the visible light transmittance of the second pressure-sensitive adhesive layer 2, it has sufficient light-shielding property in the visible light region. Since the first adhesive layer 1 having a higher light-shielding property (low transparency) seals between the LED chips 7 without a gap, it is possible to prevent color mixing between the LED chips 7 and improve the contrast. Can be done. Further, since the first pressure-sensitive adhesive layer 1 having a higher light-shielding property (low transparency) also seals the surface of the metal wiring layer 6, it is possible to prevent reflection by the metal wiring layer 6.

In the present embodiment, the second adhesive layer 2 is laminated on the upper part (display image side) of each LED chip 7 arranged on the display panel via the first base material S, and the second base material 3 is attached. It functions as an interlayer filler for bonding. Since the visible light transmittance of the second pressure-sensitive adhesive layer 2 is higher than the visible light transmittance of the first pressure-sensitive adhesive layer 1, it has sufficient transparency in the visible light region. Since the second adhesive layer 2 having higher transparency is located on the upper part (display image side) of each LED chip 7, the absorption of visible light emitted from each LED chip 7 is suppressed to a low level, and the luminous efficiency is reduced. Since it can be raised, the image can be made brighter. Further, since it is not necessary to increase the output to increase the emission brightness, the power consumption can be suppressed to a low level.

As described above, since the optical laminate according to the present embodiment contains the first pressure-sensitive adhesive layer having higher light-shielding property (lower transparency), when the metal adherend is laminated on the first pressure-sensitive adhesive layer. Even so, it is possible to prevent reflection and gloss on the metal surface. The reflectance of the 5 ° specular visible light region of the substrate surface 3a when the metal adherend is laminated on the first pressure-sensitive adhesive layer of the optical laminate of the present embodiment is preferably 50% or less. , 30% or less, more preferably 15% or less, and particularly preferably 10% or less. The glossiness (based on JIS Z 8741-1997) of the base material surface 3a when the metal adherend is laminated on the first pressure-sensitive adhesive layer of the optical laminate of the present embodiment is preferably 100% or less. , 80% or less, more preferably 60% or less, and particularly preferably 50% or less.
As the metal adherend, copper, aluminum, stainless steel, or the like can be used.

In the mini / micro LED display device of the present embodiment, the first base material S is laminated between the first pressure-sensitive adhesive layer 1 and the second pressure-sensitive adhesive layer 2. With this configuration, the first base material S physically separates the first pressure-sensitive adhesive layer 1 and the second pressure-sensitive adhesive layer 2, and for example, as described above, the first pressure-sensitive adhesive layer 1 is a colorant (particularly a dye). When the above is contained, it is possible to prevent the colorant from migrating to the second pressure-sensitive adhesive layer 2 and reducing the transmittance and the luminous efficiency.

In mini / micro LED display device of the present embodiment, the visible light transmittance T _S of the first visible light transmittance T ₁ of the adhesive layer 1, and the first substrate S may be filled with T ₁ <T _S preferable. That is, the visible light transmittance of the first base material S is preferably higher than the visible light transmittance of the first pressure-sensitive adhesive layer 2. Since the visible light transmittance of the first base material S is higher than the visible light transmittance of the first pressure-sensitive adhesive layer 1, it has sufficient transparency in the visible light region. Since the first base material S having higher transparency is located on the upper part (display image side) of each LED chip 7, the absorption of visible light emitted from each LED chip 7 is suppressed to a low level, and the luminous efficiency is high. Therefore, the image can be made brighter.

Further, in the mini / micro LED display device of the present embodiment, when the surface 3a of the second base material 3 is subjected to the antireflection treatment and / or the antiglare treatment 4, the reflection of external light on the surface 3a of the second base material 3a. The deterioration of visibility due to the reflection of images and images is prevented, or the appearance such as glossiness is adjusted. In the mini / micro LED display device 22 according to the present embodiment, the anti-glare layer 4a is formed on the surface 3a of the base material 3. The average inclination angle θa (°) of the anti-glare layer 4a of the mini / micro LED display device 22 according to the present embodiment is the same as described above.

The self-luminous display device of the present embodiment may include an optical member other than the display panel and the optical laminate. The optical member is not particularly limited, and examples thereof include a polarizing plate, a retardation plate, an antireflection film, a viewing angle adjusting film, and an optical compensation film. The optical member shall also include a member (design film, decorative film, surface protective plate, etc.) that plays a role of decoration and protection while maintaining the visibility of the display device and the input device.

In the mini / micro LED display devices 30 to 32 of the present embodiment, a display panel in which a plurality of LED chips are arranged on one side of a substrate and a first adhesive layer of the optical laminates 20 to 22 according to the present embodiment are respectively attached. It can be manufactured by manufacturing by combining.

Specifically, the display panel and the optical laminate having the first adhesive layer and / or the second adhesive layer of the first form can be attached by laminating under heating and / or pressure. .. When the display panel and the optical laminate having the first adhesive layer and / or the second adhesive layer of the second form are attached, they are laminated under heating and / or pressure and then photocured. be able to. The photo-curing can be performed in the same manner as the photo-curing that forms the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer of the first form.

When the first pressure-sensitive adhesive layer and / or the second pressure-sensitive adhesive layer is formed from a solvent-type pressure-sensitive adhesive composition containing (meth) acrylic block copolymer A, the bonding is performed by heating and pressurizing at 50 ° C. or higher. Is preferable. By heating and pressurizing at 50 ° C. or higher, the pressure-sensitive adhesive layer becomes highly fluid, sufficiently follows the steps of the LED chips arranged on the substrate, and can adhere to each other without gaps. The heating is carried out at 50 ° C. or higher, preferably 60 ° C. or higher, and more preferably 70 ° C. or higher. The pressurization is not particularly limited, but is performed at, for example, 1.5 atm or more, preferably 2 atm or more, and more preferably 3 atm or more. The heating and pressurizing can be performed using, for example, an autoclave or the like. After the mini / micro LED display device manufactured by this method is returned to room temperature (25 ° C.), the storage elastic modulus of the pressure-sensitive adhesive layer is increased, and the processability and adhesive reliability are improved.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to these Examples. The various characteristics in the following production examples were evaluated or measured by the following methods.

(Surface shape measurement)
A glass plate (thickness 1.3 mm) manufactured by Matsunami Glass Industry Co., Ltd. is attached to the surface of the anti-glare film on which the anti-glare layer is not formed with an adhesive, and a high-precision fine shape measuring instrument (trade name: Surfcoder ET4000) is attached. The surface shape of the anti-glare layer was measured under the condition of a cutoff value of 0.8 mm, and an average inclination angle θa was obtained. The high-precision fine shape measuring instrument automatically calculates the average inclination angle θa. The average inclination angle θa is based on JIS B 0601 (1994 edition).

(Haze)
By the method specified by JIS 7136, a haze meter (manufactured by Murakami Color Science Laboratory Co., Ltd., trade name "HN-150") was installed so that light was incident from the anti-glare layer surface of the anti-glare film, and the haze value was measured.

(Visible light transmittance of adhesive sheet)
The release film on one side was peeled off from the adhesive sheet, and non-alkali glass was attached to the exposed side. Then, the release film on the other surface was peeled off from the pressure-sensitive adhesive sheet to obtain a sample in which the pressure-sensitive adhesive sheet was bonded on a non-alkali glass plate. Using this sample, the transmission spectrum of the evaluation sample was measured with a visible ultraviolet spectrophotometer (manufactured by Hitachi High-Technologies Corporation, trade name "U-4100"). With the non-alkali glass (single substance) as the baseline, the ratio of the transmittance (transmitted light amount) of the evaluation sample to the transmittance (transmitted light amount) of the non-alkali glass was defined as the transmittance of the adhesive sheet. From the transmission spectrum of the adhesive sheet was calculated transmittance T _VIS wavelength 550 nm.

(Visible light transmittance of anti-glare film)
An anti-glare film was placed on a spectrophotometer U4100 (manufactured by Hitachi High-Technology Co., Ltd.) so that light was incident from the anti-glare layer side, and the transmittance (%) in the visible light region was measured. This transmittance is a Y value measured by a two-degree field of view (C light source) of JIS Z8701 and corrected for luminosity factor.

Manufacturing example 1
(Preparation of anti-glare film)
As a resin contained in the anti-glare layer, 100 parts by weight of an ultraviolet curable urethane acrylate resin (manufactured by DIC Corporation, trade name "Unidic 17-806", solid content 80%) was prepared. Styrene crosslinked particles (manufactured by Soken Kagaku Co., Ltd., trade name "MX-350H", weight average particle size: 3.5 μm, refractive index 1.59) per 100 parts by weight of the resin solid content of the resin. 14 parts by weight, 2.5 parts by weight of synthetic smectite (manufactured by Kunimine Kogyo Co., Ltd., trade name "Smecton SAN"), which is an organic clay as a styrene-imparting agent, photopolymerization initiator (manufactured by BASF, trade name "OMNIRAD907") ”) Was mixed in 5 parts by weight, and a leveling agent (manufactured by DIC Co., Ltd., trade name “Megafuck F-556”, 100% solid content) was mixed in 0.5 parts by weight. A light diffusing element forming material (coating liquid) was prepared by diluting this mixture with a mixed solvent of toluene / ethyl acetate (weight ratio 90/10) so that the solid content concentration was 30% by weight.
An anti-glare layer forming material (coating liquid) is applied to one side of a triacetyl cellulose (TAC) film (manufactured by Fujifilm, product name "TG60UL", thickness: 60 μm) that can function as a protective layer using a bar coater. A coating film was formed. Then, the transparent TAC film base material on which this coating film was formed was transported to a drying step. In the drying step, the coating film was dried by heating at 110 ° C. for 1 minute. Then, an ultraviolet ray having an integrated light amount of 300 mJ / cm ² is irradiated with a high-pressure mercury lamp, and the coating film is cured to form a light diffusing element having a thickness of 5.0 μm on one side of the TAC film to obtain an antiglare film 1. rice field. The haze value of the anti-glare film 1 was 42%. The θa (°) of the anti-glare layer of the anti-glare film 1 was 1.22. The visible light transmittance of the anti-glare film 1 was 90%.

Manufacturing example 2
(Preparation of anti-glare film)
As light diffusing fine particles, 14 parts by weight of amorphous silica (manufactured by Fuji Silysia Chemical Ltd., trade name "Silohobic 100", weight average particle size: 2.6 μm) was added, and the thickness after curing was increased to 7. An anti-glare film 2 was obtained by forming a light diffusing element on one side of the TAC film in the same manner as in Production Example 1 except that the thickness was set to 0 μm. The haze value of the anti-glare film 2 was 11%. The θa (°) of the anti-glare layer of the anti-glare film 2 was 1.43. The visible light transmittance of the anti-glare film 2 was 91%.

Manufacturing example 3
(Preparation of anti-glare film)
As a resin contained in the anti-glare layer forming material, 100 parts by weight of an ultraviolet curable urethane acrylate resin (manufactured by DIC Corporation, trade name "Unidic 17-806", solid content 80%) was prepared. 7 parts by weight of amorphous silica (manufactured by Fuji Silysia Chemical Ltd., trade name "Silohobic 702") and amorphous silica (Fuji Silysia Chemical Ltd.) per 100 parts by weight of the resin solid content of the resin. ), Product name "Silica Hobic 100") is 6.5 parts by weight, photopolymerization initiator (BASF, product name "OMNIRAD184") is 5 parts by weight, leveling agent (manufactured by DIC Corporation, product name) "Mega Fuck F-556") was mixed in an amount of 0.5 parts by weight. This mixture was diluted with toluene so that the solid content concentration became 30% to prepare an antiglare layer forming material (coating liquid).
As a translucent base material, a transparent plastic film base material (TAC film, manufactured by Fuji Film Co., Ltd., trade name "TD80UL", thickness: 80 μm) was prepared. A coating film of the anti-glare layer forming material (coating liquid) was formed on one side of the transparent plastic film base material using a bar coater. Then, the transparent plastic film base material on which this coating film was formed was transported to a drying step. In the drying step, the coating film was dried by heating at 110 ° C. for 1 minute. Then, an ultraviolet ray having an integrated light intensity of 300 mJ / cm ² was irradiated with a high-pressure mercury lamp, and the coating film was cured to form an anti-glare layer having a thickness of 5.0 μm to obtain an anti-glare film 3. The θa (°) of the anti-glare layer of the anti-glare film 3 was 3.5. The visible light transmittance of the anti-glare film 3 was 91%.

Manufacturing example 4
(Preparation of anti-glare film)
As anti-glare layer forming particles, 6.5 parts by weight of amorphous silica (manufactured by Fuji Silysia Chemical Ltd., trade name "Silohobic 702"), amorphous silica (manufactured by Fuji Silysia Chemical Ltd., trade name "Silohobic") Except that 6.5 parts by weight of 200 ") was added and 2.5 parts by weight of a thickener (manufactured by Corp Chemical, trade name" Lucentite SAN ") was added to make the thickness after curing treatment 8.0 μm. Obtained an antiglare film 4 in the same manner as in Production Example 3. The θa (°) of the anti-glare layer of the anti-glare film 4 was 2.3. The visible light transmittance of the anti-glare film 4 was 91%.

Production example 5
(Preparation of prepolymer)
In a separable flask equipped with a thermometer, agitator, a reflux cooling tube and a nitrogen gas introduction tube, 67 parts by weight of butyl acrylate (BA), cyclohexyl acrylate (CHA, manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "Viscoat # 155") 14 By weight, 19 parts by weight of 4-hydroxybutyl acrylate (4-HBA), 0.09 parts by weight of photopolymerization initiator (BASF, trade name "Irgacure 184"), and photopolymerization initiator (BASF, product) After 0.09 part by weight of the name "Irgacure 651") was added, nitrogen gas was flowed and nitrogen substitution was carried out for about 1 hour while stirring. Then, UVA was irradiated at 5 mW / cm ² to carry out polymerization, and the reaction rate was adjusted to 5 to 15% to obtain an acrylic prepolymer solution.
(Preparation of adhesive composition)
In the acrylic prepolymer solution obtained above (the total amount of the prepolymer is 100 parts by weight), 9 parts by weight of 2-hydroxyethyl acrylate (HEA), 8 parts by weight of 4-hydroxybutyl acrylate (4-HBA), and more. Add 0.12 parts by weight of dipentaerythritol hexaacrylate (manufactured by Shin-Nakamura Kogyo Kagaku, trade name "KAYARAD DPHA") as a functional monomer, and 0.35 parts by weight of 3-glycidoxypropyltrimethoxysilane as a silane coupling agent. To prepare a photopolymerizable pressure-sensitive adhesive composition solution.
(Preparation of adhesive sheet)
The photopolymerizable pressure-sensitive adhesive composition solution prepared above is cured on the peeling surface of a release film R1 (manufactured by Mitsubishi Resin Co., Ltd., trade name "MRF # 38") having a thickness of 38 μm in which one side of the polyester film is a peeling surface. After that, the film was applied so as to have a thickness of 100 μm, and the polyester film was covered with a release film R2 (MRE # 38 manufactured by Mitsubishi Resin Co., Ltd.) having a release surface on one side to block air. Ultraviolet rays were irradiated from one side of this laminate using a black light (manufactured by Toshiba Corporation, trade name "FL15BL") under ^{the conditions of an illuminance of 5 mW / cm 2} and an integrated light intensity of 1300 mJ / cm ^2. As a result, a pressure-sensitive adhesive sheet 1 having a thickness of 100 μm in which the photocrosslinkable pressure-sensitive adhesive, which is a cured product of the black pressure-sensitive adhesive composition, was sandwiched between the release films R1 and R2 was obtained in the form of a base material-less pressure-sensitive adhesive sheet.
The visible light transmittance of the adhesive sheet 1 was 90%.

Production example 6
(Preparation of adhesive polymer)
In a reaction vessel equipped with a thermometer, a stirrer, a reflux cooling tube and a nitrogen gas introduction tube, 63 parts by mass of 2-ethylhexyl acrylate (2EHA), 15 parts by mass of N-vinylpyrrolidone (NVP), and methyl methacrylate as monomer components. 9 parts by mass of (MMA), 13 parts by mass of 2-hydroxyethyl acrylate (HEA), 0.2 parts by mass of azobisisobutyronitrile as a polymerization initiator, and 233 parts by mass of ethyl acetate as a solvent were added, and nitrogen gas was added. Was allowed to flow, and the mixture was replaced with nitrogen for about 1 hour with stirring. Then, the mixture was heated to 60 ° C. and reacted for 7 hours to obtain a solution of a sticky polymer having a weight average molecular weight (Mw) of 1200,000.
The glass dislocation temperature of the adhesive polymer calculated by the FOX formula was −34 ° C.
(Preparation of adhesive composition)
In the adhesive polymer solution obtained above, Takenate D-110N (75% ethyl acetate solution of trimethylolpropane adduct of xylylene diisocyanate, manufactured by Mitsui Chemicals, Inc.) was added as a cross-linking agent to the adhesive polymer solution. 1.1 parts by mass with respect to 100 parts by mass of the adhesive polymer, 0.5 mass by mass of the dye (NUBIAN Black PA-2802, manufactured by Orient Chemical Industry Co., Ltd.) with respect to 100 parts by mass of the adhesive polymer in the solution of the adhesive polymer. Parts were added and mixed uniformly to prepare a solution of a black solvent-type pressure-sensitive adhesive composition.
(Preparation of adhesive sheet)
On one side of a polyethylene terephthalate film having a thickness of 50 μm that has been surface-released, the solution of the black solvent-type pressure-sensitive adhesive composition obtained above is applied by a fountain roll so that the thickness after drying is 25 μm. It was applied and dried at 130 ° C. for 1 minute to remove the solvent. As a result, an adhesive layer was formed. Further, a release-treated surface of a release film (a polyethylene terephthalate film having a thickness of 25 μm with a silicone release-treated surface) was attached to one surface of the pressure-sensitive adhesive. Then, the aging treatment was carried out in an atmosphere of 25 ° C. for 4 days to allow the cross-linking reaction to proceed. As a result, the pressure-sensitive adhesive sheet 2 (a 25 μm pressure-sensitive adhesive layer) was obtained in the form of a base material-less pressure-sensitive adhesive sheet.
The visible light transmittance of the adhesive sheet 2 was 55%.

Production example 7
An adhesive sheet 3 (25 μm adhesive layer) was obtained in the form of a base material-less adhesive sheet in the same manner as in Production Example 6 except that a dye (NUBIAN Black PA-2802 manufactured by Orient Chemical Industries Co., Ltd.) was not blended. rice field.
The visible light transmittance of the adhesive sheet 3 was 90%.

Example 1
(Preparation of optical laminate)
One of the release films was peeled off from the adhesive sheet 1 obtained in Production Example 5, and the exposed adhesive surface was cut into 50 mm × 50 mm and bonded to TAC film 1 (thickness: 60 μm; visible light transmittance: 91%). rice field. Then, the other release film was peeled from the adhesive sheet 1, and the exposed adhesive surface was attached to a TAC film 2 (thickness: 60 μm; visible light transmission: 91%) cut into 50 mm × 50 mm, and further, a production example. One of the release films is peeled off from the adhesive sheet 2 obtained in No. 6, and the exposed adhesive surfaces are bonded to each other to form an optical laminate composed of TAC film 1 / adhesive sheet 1 / TAC film 2 / adhesive sheet 2 / release film. I got 1.

Example 2
(Preparation of optical laminate)
TAC film 1 / adhesive sheet 1 / TAC film 3 / adhesive in the same manner as in Example 1 except that TAC film 3 (thickness: 40 μm; visible light transmittance: 90%) was used instead of TAC film 2. An optical laminate 2 made of a sheet 2 / release film was obtained.

Example 3
(Preparation of optical laminate)
TAC film 1 / adhesive sheet 1 / PET film 1 / adhesive in the same manner as in Example 1 except that PET film 1 (thickness: 50 μm; visible light transmittance: 90%) was used instead of TAC film 2. An optical laminate 3 made of a sheet 2 / release film was obtained.

Example 4
(Preparation of optical laminate)
An optical laminate 4 composed of TAC film 1 / adhesive sheet 3 / TAC film 2 / adhesive sheet 2 / release film was obtained in the same manner as in Example 1 except that the adhesive sheet 3 was used instead of the adhesive sheet 1. rice field.

Example 5
(Preparation of optical laminate)
TAC film 1 / adhesive sheet 3 / TAC film 3 / adhesive sheet 2 in the same manner as in Example 1 except that the TAC film 3 was used instead of the TAC film 2 and the adhesive sheet 3 was used instead of the adhesive sheet 1. / An optical laminate 5 made of a release film was obtained.

Example 6
(Preparation of optical laminate)
TAC film 1 / adhesive sheet 3 / PET film 1 / adhesive sheet 2 in the same manner as in Example 1 except that the PET film 1 was used instead of the TAC film 2 and the adhesive sheet 3 was used instead of the adhesive sheet 1. / An optical laminate 6 made of a release film was obtained.

Comparative Example 1
(Preparation of optical laminate)
One of the release films was peeled off from the adhesive sheet 1 obtained in Production Example 5, and the exposed adhesive surface was attached to the TAC film 1 cut into 50 mm × 50 mm. Then, the other release film was peeled off from the pressure-sensitive adhesive sheet 1, and the exposed pressure-sensitive adhesive surface was peeled off from the pressure-sensitive adhesive sheet 2 obtained in Production Example 6, and the exposed pressure-sensitive adhesive surface was bonded to each other. An optical laminate 7 composed of a TAC film 1 / adhesive sheet 1 / adhesive sheet 2 / release film was obtained.

Comparative Example 2
(Preparation of optical laminate)
An optical laminate 8 composed of a TAC film 1 / adhesive sheet 3 / adhesive sheet 2 / release film was obtained in the same manner as in Comparative Example 1 except that the adhesive sheet 3 was used instead of the adhesive sheet 1.

(evaluation)
The following evaluations were made using the optical laminates obtained in the above Examples and Comparative Examples. The evaluation method is shown below.

(1) Evaluation of Color Transfer The optical laminates obtained in Examples and Comparative Examples were cut by a microtome after the initial and reliability tests, and then the cut surface was observed with an optical microscope to observe the black color contained in the adhesive sheet 2. It was confirmed whether the dye had transferred to the pressure-sensitive adhesive sheet 1 or 3 and turned black. Those without color transfer were evaluated as 〇, and those without color transfer were evaluated as ×. The results are shown in Table 1.
The reliability test was carried out by allowing the mixture to stand for 350 hours in an environment with a temperature of 85 ° C. and a humidity of 85%.

(2) Visible light transmittance The optical laminates obtained in the above Examples and Comparative Examples are installed in a spectrophotometer U4100 (manufactured by Hitachi High-Technology Co., Ltd.) so that light is incident from the glass plate side, and is visible. The transmittance (%) in the optical region was measured. This transmittance is a Y value measured by a two-degree field of view (C light source) of JIS Z8701 and corrected for luminosity factor. The results are shown in Table 1.

(3) Reflectance An aluminum foil was attached to a black acrylic plate to prepare a laminated plate. The adhesive surface exposed by peeling off the release film of the optical laminate obtained in the above Examples and Comparative Examples was laminated on the aluminum foil side of the above plate to prepare a sample. The obtained sample was placed on a spectrophotometer U4100 (manufactured by Hitachi High-Technology Co., Ltd.) with an antiglare film / TAC film on the light source side, and the reflectance (%) in the visible light region of 5 ° specular reflection was measured. The results are shown in Table 1.

Example 7
(Preparation of optical laminate)
One of the release films was peeled off from the pressure-sensitive adhesive sheet 1 obtained in Production Example 5, and the exposed adhesive surface was cut to 50 mm × 50 mm to form the anti-glare layer of the anti-glare film 1 obtained in Production Example 1. Stick it on the surface. Then, the other release film is peeled from the adhesive sheet 1, and the exposed adhesive surface is attached to the TAC film 2 cut into 50 mm × 50 mm, and further, one release film from the adhesive sheet 2 obtained in Production Example 6 is attached. Is peeled off, and the exposed adhesive surfaces are laminated to obtain an optical laminate 9 composed of an antiglare film 1 / adhesive sheet 1 / TAC film 2 / adhesive sheet 2 / release film.

Examples 8-10
(Preparation of optical laminate)
Anti-glare films 2-4 // adhesive sheet 1 in the same manner as in Example 7 except that the anti-glare films 2 to 4 obtained in Production Examples 2 to 4 were used instead of the anti-glare films 1. An optical laminate 10 to 12 composed of / TAC film 2 / adhesive sheet 2 / release film is obtained.

10, 20, 21, 22 Optical laminate 1 1st adhesive layer 2 2nd adhesive layer S 1st base material 3 2nd base material 4 Antireflection treatment and / or anti-glare treatment 4a Anti-glare layers 30, 31, 32 Luminous display device (mini / micro LED display device)
5 Substrate 6 Metal wiring layer 7 Light emitting element (LED chip)

Claims (20)

The first pressure-sensitive adhesive layer, the base material, and the second pressure-sensitive adhesive layer have a laminated structure in which they are laminated in this order.
The visible light transmittance of the first pressure-sensitive adhesive layer T _1, and the visible light transmittance T ₂ of the second adhesive layer satisfy T ₁ <T _2, the optical stack. The visible light transmittance of the first pressure-sensitive adhesive layer T _1, and the visible light transmittance T _S of the substrate, T ₁ <satisfy T _S, claim 1 laminated body for optical purposes according. The optical laminate according to claim 1 or 2, _{wherein the visible light transmittance T 1} of the first pressure-sensitive adhesive layer is 80% or less. The optical laminate according to any one of claims 1 to 3, _{wherein the visible light transmittance T 2} of the second pressure-sensitive adhesive layer is 85 to 100%. The first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are pressure-sensitive adhesive layers formed from a pressure-sensitive adhesive composition selected from a photocurable pressure-sensitive adhesive composition and a solvent-type pressure-sensitive adhesive composition. The optical laminate according to any one of 4. The optical laminate according to claim 5, wherein the pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer contains a colorant. The optical laminate according to claim 5 or 6, wherein the pressure-sensitive adhesive composition contains an acrylic polymer. The optical laminate according to claim 7, wherein the acrylic polymer contains a (meth) acrylic block copolymer. The optical laminate according to claim 8, wherein the pressure-sensitive adhesive composition forming the first pressure-sensitive adhesive layer is a solvent-type pressure-sensitive adhesive composition containing a (meth) acrylic block copolymer. The optical laminate according to any one of claims 1 to 9, wherein the thickness of the first pressure-sensitive adhesive layer is 10 to 300 μm. The optical laminate according to any one of claims 1 to 10, wherein the thickness of the second pressure-sensitive adhesive layer is 1 to 500 μm. The ratio of the thickness of the second pressure-sensitive adhesive layer to the thickness of the first pressure-sensitive adhesive layer (thickness of the second pressure-sensitive adhesive layer / thickness of the first pressure-sensitive adhesive layer) is 1.0 to 5.0. The optical laminate according to any one of 1 to 11. The optical laminate according to any one of claims 1 to 12, wherein the surface of the second pressure-sensitive adhesive layer on which the base material is not laminated is further laminated with the second base material. The optical laminate according to claim 13, wherein the surface of the second base material on which the second pressure-sensitive adhesive layer is not laminated is subjected to antireflection treatment and / or antiglare treatment. The optical laminate according to claim 14, wherein the anti-glare prevention treatment is an anti-glare layer provided on one side of the second base material. The anti-glare layer is formed using an anti-glare layer-forming material containing a resin, particles and a thixotropy-imparting agent.
The optical laminate according to claim 14, wherein the anti-glare layer has an aggregated portion that forms a convex portion on the surface of the anti-glare layer by aggregating the particles and the thixotropy-imparting agent. The optical laminate according to claim 16, wherein the average inclination angle θa (°) is in the range of 0.1 to 1.5 in the convex portion on the surface of the anti-glare layer. The optical laminate according to any one of claims 13 to 17, wherein a surface protective film is laminated on a surface of the second base material on which the second pressure-sensitive adhesive layer is not laminated. A display panel in which multiple light emitting elements are arranged on one side of the substrate,
A self-luminous display device comprising the optical laminate according to any one of claims 1 to 18.
A self-luminous display device in which the surface on which the light emitting elements of the display panel are arranged and the first pressure-sensitive adhesive layer of the optical laminate are laminated. The self-luminous display device according to claim 19, wherein the display panel is an LED panel in which a plurality of LED chips are arranged on one side of a substrate.

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