Optical laminate and image display device

Abstract

The present invention provides an optical laminate comprising an adhesive sheet formed from a photocurable adhesive composition, the optical laminate being capable of suppressing occurrence of light leakage caused by a local load. Also provided is an image display device including such an optical laminate. An optical laminate according to an embodiment of the present invention comprises a first optical member, a first adhesive sheet, a second optical member, a second adhesive sheet, and a polarizing film in the stated order. The first adhesive sheet is formed from a photocurable first adhesive composition. The second adhesive sheet is formed from a photocurable second adhesive composition. The total thickness of the first adhesive sheet and the second adhesive sheet is equal to or greater than 30 μｍ.

Description

Optical laminates and image display devices

[0001] This invention relates to an optical laminate and an image display device.

[0002] In image display devices (such as liquid crystal displays, organic EL displays, and quantum dot displays), a polarizing film is often placed on at least one side of the display cell, depending on the image formation method. It is widely known that the polarizing film placed on the viewing side of an image display device is provided with optical elements such as an anti-reflective layer or an anti-reflection layer on the viewing side to prevent reflection and glare of external light onto the display screen.

[0003] Typically, a bonding layer is placed between multiple optical components to join them together. An example of a bonding layer is an adhesive sheet formed from an adhesive composition. Patent Document 1 discloses an example of an adhesive sheet. In Patent Document 1, the adhesive sheet is made from a thermosetting adhesive composition. In addition to thermosetting adhesive compositions, there are also known photocurable adhesive compositions that can be used to produce adhesive sheets using light.

[0004] Japanese Patent Publication No. 2017-14376

[0005] Foldable image display devices, such as laptop computers, where the image display unit is located on the inside when folded, are widely used. However, when such image display devices are folded, if foreign objects get caught in the fold, a localized load caused by these objects is applied to the image display unit. This localized load can damage the polarizing film or other components, resulting in a problem where light leakage occurs in the image display unit.

[0006] The object of the present invention is to provide an optical laminate comprising an adhesive sheet formed from a photocurable adhesive composition, which can suppress the occurrence of light loss due to localized load. Furthermore, the invention aims to provide an image display device comprising such an optical laminate.

[0007] [1] An optical laminate according to an embodiment of the present invention comprises a first optical member, a first adhesive sheet, a second optical member, a second adhesive sheet, and a polarizing film in this order, wherein the first adhesive sheet is formed from a photocurable first adhesive composition, the second adhesive sheet is formed from a photocurable second adhesive composition, and the sum of the thickness of the first adhesive sheet and the thickness of the second adhesive sheet is 30 μm or more. [2] An optical laminate according to an embodiment of the present invention comprises a first optical member, a first adhesive sheet, a second optical member, a second adhesive sheet, a third optical member, a polarizing film, a first phase difference film, and a second phase difference film in this order, wherein the thickness of the second phase difference film is 10 μm or more, the first adhesive sheet is formed from a photocurable first adhesive composition, the second adhesive sheet is formed from a photocurable second adhesive composition, and the sum of the thickness of the first adhesive sheet and the thickness of the second adhesive sheet is 20 μm or more. [3] In the optical laminate described in [1] or [2] above, at least one selected from the group consisting of the thickness of the first adhesive sheet and the thickness of the second adhesive sheet may be 20 μm or more. [4] In the optical laminate described in any of [1] to [3] above, the total value may be less than 60 μm. [5] The optical laminate described in [1] above may further include a first phase difference film and a second phase difference film located on the opposite side of the first optical member from the polarizing film, and the polarizing film, the first phase difference film and the second phase difference film may be arranged in this order. [6] In the optical laminate described in [5] above, the thickness of the second phase difference film may be 10 μm or more. [7] In the optical laminate described in any of [1] to [6] above, the first adhesive composition may contain monomer component M1, and the monomer component M1 may contain a nitrogen atom-containing monomer. [8] In the optical laminate described in any of [1] to [7] above, the second adhesive composition may contain monomer component M2, and the monomer component M2 may contain a nitrogen atom-containing monomer.[9] In the optical laminate described in any of [1] to [8] above, the first optical member may have a hard coat layer.

[10] In the optical laminate described in [9] above, the indentation modulus of the hard coat layer may be 5 GPa or more.

[11] An image display device according to an embodiment of the present invention comprises the optical laminate described in any of [1] to

[10] above.

[0008] According to embodiments of the present invention, it is possible to provide an optical laminate comprising an adhesive sheet formed from a photocurable adhesive composition, which can suppress the occurrence of light loss due to localized loads. Furthermore, it is possible to provide an image display device equipped with such an optical laminate.

[0009] This is a schematic cross-sectional view of an optical laminate according to one embodiment of the present invention. This is a schematic cross-sectional view of an optical laminate according to another embodiment of the present invention.

[0010] [Regarding Terminology] In this specification, where the term "weight" appears, it may be interpreted as "mass," which is the commonly used SI unit for weight. The reverse is also true.

[0011] In this specification, the expression "(meth)acrylic" means "acrylic and / or methacrylic," the expression "(meth)acrylate" means "acrylate and / or methacrylate," the expression "(meth)allyl" means "allyl and / or methallyl," and the expression "(meth)acrolein" means "acrolein and / or metacrolein."

[0012] In this specification, "monomer component" as a criterion for the content of various components in an adhesive composition means the sum of monomer components that have not been partially polymerized and monomer components that have been used to form partially polymerized products that may be contained in the adhesive composition.

[0013] In this specification, with respect to the refractive index (nx, ny, nz), "nx" is the refractive index in the direction in which the refractive index is maximum in the plane (i.e., in the direction of the slow phase axis), "ny" is the refractive index in the direction perpendicular to the slow phase axis in the plane (i.e., in the direction of the fast phase axis), and "nz" is the refractive index in the thickness direction. In this specification, nx, ny, and nz are values ​​for light with a wavelength of 550 nm.

[0014] In this specification, with respect to the in-plane phase difference (Re), "Re(λ)" is the in-plane phase difference of the film measured with light of wavelength λ nm at 23°C. For example, "Re(550)" is the in-plane phase difference of the film measured with light of wavelength 550 nm at 23°C. Re(λ) can be calculated by the formula: Re = (nx - ny) × d, where d (nm) is the thickness of the film.

[0015] In this specification, with respect to the phase difference in the thickness direction (Rth), "Rth(λ)" is the phase difference in the thickness direction of the film measured with light of wavelength λ nm at 23°C. For example, "Rth(550)" is the phase difference in the thickness direction of the film measured with light of wavelength 550 nm at 23°C. Rth(λ) can be calculated by the formula: Rth = (nx - nz) × d, where the thickness of the film is d (nm).

[0016] In this specification, the "Nz coefficient" is determined by Nz = Rth / Re.

[0017] In this specification, when an angle is mentioned, unless otherwise specified, that angle includes angles in both clockwise and counterclockwise directions.

[0018] ≪≪1. Optical Laminate≫≫ An optical laminate according to an embodiment of the present invention comprises a first optical member, a first adhesive sheet, a second optical member, a second adhesive sheet, and a polarizing film in this order. The first adhesive sheet is formed from a photocurable first adhesive composition. The second adhesive sheet is formed from a photocurable second adhesive composition. The sum of the thicknesses of the first adhesive sheet and the second adhesive sheet is 30 μm or more.

[0019] The optical laminate may include any other suitable components as long as it has the above-mentioned components, without impairing the effects of the present invention. For example, the optical laminate may further include a third optical component, a first phase difference film, and a second phase difference film, and more specifically, it may include a first optical component, a first adhesive sheet, a second optical component, a second adhesive sheet, a third optical component, a polarizing film, a first phase difference film, and a second phase difference film in this order. In this configuration, the thickness of the second phase difference film is, for example, 10 μm or more. When the optical laminate includes a third optical component, the sum of the thicknesses of the first adhesive sheet and the second adhesive sheet does not necessarily have to be 30 μm or more; the sum may be 20 μm or more.

[0020] ≪1-1. Overall Configuration of the Optical Laminate≫ Figure 1 is a typical schematic cross-sectional view of an optical laminate according to an embodiment of the present invention. The optical laminate 100 shown in Figure 1 comprises a first optical member 31, a first adhesive sheet 21, a second optical member 32, a second adhesive sheet 22, and a polarizing film 10 in this order. The first optical member 31, the first adhesive sheet 21, the second optical member 32, and the second adhesive sheet 22 are located, for example, on the viewing side of the polarizing film 10. The first optical member 31 and the second optical member 32 may be bonded together via the first adhesive sheet 21, and the second optical member 32 and the polarizing film 10 may be bonded together via the second adhesive sheet 22.

[0021] As shown in Figure 1, the optical laminate 100 may further include a first phase difference film 40 and a second phase difference film 50 located on the opposite side of the polarizing film 10 from the first optical member 31. The first phase difference film 40 and the second phase difference film 50 are located, for example, on the opposite side of the polarizing film 10 from the viewing side. In the optical laminate 100, the polarizing film 10, the first phase difference film 40, and the second phase difference film 50 may be arranged in this order.

[0022] As shown in Figure 1, the optical laminate 100 may further include a panel-side adhesive sheet 60. The panel-side adhesive sheet 60 is positioned on the opposite side of the first phase difference film 40 to the second phase difference film 50. When the optical laminate 100 includes the panel-side adhesive sheet 60, the panel-side adhesive sheet 60 allows the optical laminate 100 to be attached to an image display cell. The optical laminate 100 shown in Figure 1 typically has the following configuration from the viewing side: first optical member 31 / first adhesive sheet 21 / second optical member 32 / second adhesive sheet 22 / polarizing film 10 / first phase difference film 40 / second phase difference film 50 / panel-side adhesive sheet 60.

[0023] Figure 2 is a schematic cross-sectional view of another representative optical laminate according to an embodiment of the present invention. The optical laminate 100 shown in Figure 2 comprises a first optical member 31, a first adhesive sheet 21, a second optical member 32, a second adhesive sheet 22, a third optical member 33, and a polarizing film 10 in this order. The first optical member 31, the first adhesive sheet 21, the second optical member 32, the second adhesive sheet 22, and the third optical member 33 are located, for example, on the viewing side of the polarizing film 10. The first optical member 31 and the second optical member 32 may be bonded together via the first adhesive sheet 21, and the second optical member 32 and the third optical member 33 may be bonded together via the second adhesive sheet 22.

[0024] As shown in Figure 2, the optical laminate 100 may further include a third adhesive sheet 23 positioned between the third optical member 33 and the polarizing film 10. The third optical member 33 and the polarizing film 10 may be bonded together via the third adhesive sheet 23.

[0025] As shown in Figure 2, the optical laminate 100 may further include a first phase difference film 40 and a second phase difference film 50 located on the opposite side of the first optical member 31 from the polarizing film 10. The first phase difference film 40 and the second phase difference film 50 are located, for example, on the opposite side of the polarizing film 10 from the viewing side. In the optical laminate 100, the polarizing film 10, the first phase difference film 40, and the second phase difference film 50 may be arranged in this order.

[0026] As shown in FIG. 2, the optical laminate 100 may further include a panel-side adhesive sheet 60. The panel-side adhesive sheet 60 is disposed on the opposite side of the first retardation film 40 with respect to the second retardation film 50. When the optical laminate 100 includes the panel-side adhesive sheet 60, the optical laminate 100 can be attached to an image display cell by the panel-side adhesive sheet 60. The optical laminate 100 shown in FIG. 2 typically has a configuration of, in order from the viewing side, a first optical member 31 / a first adhesive sheet 21 / a second optical member 32 / a second adhesive sheet 22 / a third optical member 33 / a third adhesive sheet 23 / a polarizing film 10 / a first retardation film 40 / a second retardation film 50 / a panel-side adhesive sheet 60.

[0027] The optical laminate according to the embodiment of the present invention may adopt any appropriate configuration as long as it includes a first optical member, a first adhesive sheet, a second optical member, a second adhesive sheet, and a polarizing film in this order. Typically, it is the configuration shown in FIGS. 1 to 2 above. For example, in the configuration shown in FIG. 1 (the configuration of the first optical member 31 / the first adhesive sheet 21 / the second optical member 32 / the second adhesive sheet 22 / the polarizing film 10), the number of components provided between the first optical member 31 and the polarizing film 10 can be reduced, which can be advantageous from the viewpoints of cost and environment. In the case of the configuration shown in FIG. 2 (the configuration of the first optical member 31 / the first adhesive sheet 21 / the second optical member 32 / the second adhesive sheet 22 / the third optical member 33 / the polarizing film 10), there is a tendency to more effectively suppress the occurrence of light leakage due to local load.

[0028] The total thickness of the optical laminate 100 according to the embodiment of the present invention can adopt any appropriate total thickness as long as the effects of the present invention are not impaired. In terms of more effectively expressing the effects of the present invention, the total thickness of the optical laminate 100 according to the embodiment of the present invention is preferably 200 μm or more, more preferably 200 μm to 400 μm, still more preferably 220 μm to 380 μm, particularly preferably 250 μm to 350 μm, and most preferably 260 μm to 330 μm.

[0029] In the optical laminate 100 according to an embodiment of the present invention, the total value of the thickness of the first adhesive sheet 21 and the thickness of the second adhesive sheet 22 is 30 μm or more as described above, and may be 35 μm or more, 40 μm or more, 45 μm or more, 50 μm or more, and further may be 55 μm or more. The larger this total value is, the more likely it is to suppress the occurrence of light leakage due to local load. The upper limit of the total value may be, for example, 100 μm or less, 80 μm or less, 70 μm or less, 65 μm or less, 60 μm or less, less than 60 μm, and further may be 58 μm or less. According to the study by the present inventors, when the total value is small, the pencil hardness of the optical laminate tends to increase and the scratch resistance tends to improve. The total value is preferably 30 μm or more and less than 60 μm.

[0030] As described above, when the optical laminate 100 further includes the third optical member 33, it is not always necessary for the total value of the thickness of the first adhesive sheet 21 and the thickness of the second adhesive sheet 22 to be 30 μm or more. In this case, the total value may be 20 μm or more, may be 23 μm or more, 25 μm or more, and further may be 28 μm or more. The total value may be 20 μm or more and less than 30 μm.

[0031] In the optical laminate 100 according to an embodiment of the present invention, the thicknesses of the first adhesive sheet 21 and the second adhesive sheet 22 may adopt any appropriate thickness as long as the effects of the present invention are not impaired. In terms of more effectively expressing the effects of the present invention, at least one selected from the group consisting of the thickness of the first adhesive sheet 21 and the thickness of the second adhesive sheet 22 is preferably, for example, 12 μm or more, 13 μm or more, 15 μm or more, 18 μm or more, and further preferably 20 μm or more.

[0032] The thickness of the first adhesive sheet 21 may be, for example, 5 μm or more, 10 μm or more, 13 μm or more, 15 μm or more, 18 μm or more, 20 μm or more, and further may be 25 μm or more. The upper limit of the thickness of the first adhesive sheet 21 may be, for example, 80 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 35 μm or less, and further may be 30 μm or less. The thickness of the first adhesive sheet 21 is preferably 10 μm to 50 μm, and more preferably 20 μm to 40 μm.

[0033] The thickness of the second adhesive sheet 22 is, for example, 5 μm or more, and may be 10 μm or more, 13 μm or more, 15 μm or more, 18 μm or more, 20 μm or more, and even 25 μm or more. The upper limit of the thickness of the second adhesive sheet 22 is, for example, 80 μm or less, and may be 60 μm or less, 50 μm or less, 40 μm or less, 35 μm or less, and even 30 μm or less. The thickness of the second adhesive sheet 22 is preferably 10 μm to 50 μm, and more preferably 20 μm to 40 μm. The thickness of the second adhesive sheet 22 may be greater than or less than the thickness of the first adhesive sheet 21. The thickness of the second adhesive sheet 22 may be the same as the thickness of the first adhesive sheet 21.

[0034] The optical laminate 100 according to the embodiment of the present invention preferably has a maximum allowable load of 7 kg or more, more preferably 8 kg or more, 9 kg or more, and even more preferably 10 kg or more, as determined by the method described later. The upper limit of the maximum allowable load may be, for example, 30 kg or less, 20 kg or less, and even 15 kg or less.

[0035] The maximum allowable load mentioned above can be determined by the following method. First, a test sample is prepared by cutting the optical laminate to a size of 50 mm x 50 mm and attaching it to a 1.2 mm thick glass plate via an adhesive sheet (specifically, an adhesive sheet on the panel side). Next, at room temperature (23°C ± 3°C), a piercing jig with a tip radius of curvature R of 550 μm is pierced into the optical laminate of the test sample with a load of 5 kg. After the piercing test, the polarizer of the optical laminate and the polarizer attached to the microscope are positioned to form crossed nicols, and the light leakage at this time is observed with a microscope.

[0036] If the puncture test results show no light leakage, or only slight leakage that does not pose a practical problem (Evaluation A), the load on the puncture jig used to puncture the test sample is increased by 1 kg (changing the load to 6 kg), and the puncture test is repeated using the same method as above. In this way, the puncture test is repeated by increasing the load on the puncture jig used to puncture the test sample by 1 kg each time, as long as Evaluation A is obtained. The puncture test is terminated when light leakage is observed to an extent that has a practical impact or is unacceptable for practical purposes (Evaluation B), and the load on the puncture jig used in the last puncture test that obtained Evaluation A is identified as the maximum allowable load. The maximum allowable load is an indicator of the resistance to light leakage caused by localized loads.

[0037] The optical laminate 100 according to the embodiment of the present invention preferably has a pencil hardness of H or higher, and may be 2H or higher, and more preferably 3H or higher. The upper limit of the pencil hardness is, for example, 9H or lower, and may be 8H or lower, 7H or lower, 6H or lower, and even more preferably 5H or lower.

[0038] The pencil hardness described above can be determined by the following method. First, a test sample is prepared by cutting the optical laminate to a size of 50 mm x 150 mm and attaching it to a 1.2 mm thick glass plate via an adhesive sheet (specifically, an adhesive sheet on the panel side). A pencil hardness test is then performed on the surface of this test sample (specifically, the surface of the first optical component). The pencil hardness test is performed using a commercially available pencil hardness tester under the following conditions: pencil hardness H, load 500 g, sliding speed 30 mm / min, sliding distance 10 mm, and number of sliding cycles 1.

[0039] If, after performing the above pencil hardness test five times, scratches or dents occur on the surface of the test sample once or less (Evaluation A), the pencil hardness is increased by one step (changed to 2H), and the pencil hardness test is repeated using the same method as above. In this way, the pencil hardness test is repeated by increasing the hardness of the pencil used by one step each time, as long as Evaluation A is obtained. If scratches or dents occur on the surface of the test sample two or more times out of five (Evaluation B), the pencil hardness test is terminated, and the hardness of the pencil used in the last pencil hardness test that obtained Evaluation A is identified as the pencil hardness of the optical laminate.

[0040] The following describes the components of the optical laminate.

[0041] ≪1-2. Polarizing Film≫ The polarizing film 10 typically comprises a polarizer and a protective layer positioned on the viewing side of the polarizer. The protective layer is typically bonded to the viewing side of the polarizer via any suitable adhesive layer (not shown). That is, the polarizing film 10 may consist of a polarizer, an adhesive layer, and a protective layer. The adhesive layer refers to at least one selected from the group consisting of a tack layer and an adhesive layer.

[0042] Using the embodiment shown in Figure 1 as an example, the protective layer is located between the polarizer and the second adhesive sheet 22 and is in contact with the second adhesive sheet 22. The protective layer may be pressure-sensitively bonded to the second adhesive sheet 22. The polarizing film 10 may further include a second protective layer on the side opposite to the viewing side of the polarizer.

[0043] <1-2-a. Polarizer> Any suitable polarizer can be used as the polarizer. For example, the resin film forming the polarizer may be a single layer resin film or a laminate of two or more layers.

[0044] A specific example of a polarizer composed of a single layer of resin film is one in which a PVA-based resin film has been subjected to iodine dyeing and stretching (typically uniaxial stretching). Iodine dyeing is performed, for example, by immersing the PVA-based resin film in an iodine aqueous solution. The stretching ratio is preferably 3 to 7 times. Stretching may be performed after the dyeing treatment, or during the dyeing process. Alternatively, dyeing may be performed after stretching. If necessary, the PVA-based resin film may be subjected to swelling, crosslinking, washing, drying, etc. For example, immersing the PVA-based resin film in water and washing it before dyeing can not only wash away dirt and blocking agents from the surface of the PVA-based resin film, but also swell the PVA-based resin film to prevent uneven dyeing.

[0045] Specific examples of polarizers composed of two or more laminates include polarizers composed of a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or polarizers composed of a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate. A polarizer composed of a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate can be produced, for example, by applying a PVA-based resin solution to a resin substrate, drying it to form a PVA-based resin layer on the resin substrate to obtain a laminate of the resin substrate and the PVA-based resin layer, and then stretching and dyeing the laminate to make the PVA-based resin layer a polarizer. In a preferred embodiment, a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin is formed on one side of the resin substrate. Stretching typically includes immersing the laminate in an aqueous boric acid solution and stretching it. Furthermore, the stretching process may, if necessary, further include air stretching of the laminate at a high temperature (e.g., 95°C or higher) before stretching in an aqueous boric acid solution. In addition, in a preferred embodiment, the laminate is subjected to a drying shrinkage treatment in which it shrinks by 2% or more in the width direction by heating while being transported in the longitudinal direction. Typically, the laminate is subjected to air auxiliary stretching, dyeing, water stretching, and drying shrinkage treatment in this order. By introducing auxiliary stretching, it is possible to increase the crystallinity of PVA even when PVA is coated onto a thermoplastic resin, thereby achieving high optical properties. At the same time, by increasing the orientation of PVA in advance, it is possible to prevent problems such as a decrease in the orientation of PVA or dissolution when immersed in water in the subsequent dyeing and stretching processes, thereby achieving high optical properties. Furthermore, when the PVA-based resin layer is immersed in a liquid, the disorder of the orientation of polyvinyl alcohol molecules and the decrease in orientation can be suppressed compared to when the PVA-based resin layer does not contain halides. This makes it possible to improve the optical properties of polarizers obtained through processing steps that involve immersing the laminate in a liquid, such as dyeing and underwater stretching. Furthermore, the optical properties can be improved by shrinking the laminate in the width direction through a drying shrinkage treatment.The resulting resin substrate / polarizer laminate may be used as is (i.e., the resin substrate may be used as a protective layer for the polarizer), or the resin substrate may be peeled off from the resin substrate / polarizer laminate, and any appropriate protective layer may be laminated onto the peeled surface according to the purpose. Details of such polarizer manufacturing methods are described, for example, in Japanese Patent Application Publication No. 2012-73580 and Japanese Patent No. 6470455. The entire contents of these publications are incorporated herein by reference.

[0046] The polarizer is preferably composed of a laminate of two or more layers, and more preferably composed of a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate.

[0047] The thickness of the polarizer can be any appropriate thickness, as long as it does not impair the effects of the present invention. In terms of better exhibiting the effects of the present invention, the thickness of the polarizer is preferably 1 μm to 15 μm, more preferably 2 μm to 12 μm, even more preferably 3 μm to 10 μm, and particularly preferably 3 μm to 8 μm.

[0048] The polarizer preferably exhibits absorption dichroism at any wavelength between 380 nm and 780 nm. The transmittance of the polarizer is, for example, 41.5% to 46.0%, preferably 43.0% to 46.0%, and more preferably 44.5% to 46.0%. The degree of polarization of the polarizer is preferably 97.0% or higher, more preferably 99.0% or higher, and even more preferably 99.9% or higher.

[0049] <1-2-b. Protective Layer> The protective layer can be formed from any suitable film that can be used as a protective layer for the polarizer. Examples of materials that make up the main components of the above film include cellulosic resins such as triacetylcellulose (TAC), polyester resins, polyvinyl alcohol resins, polycarbonate resins, polyamide resins, polyimide resins, polyethersulfone resins, polysulfone resins, polystyrene resins, polynorbornene resins, polyolefin resins, (meth)acrylic resins, acetate resins, and other transparent resins. Other examples of materials that make up the main components of the above film include thermosetting resins or UV-curing resins such as (meth)acrylic, urethane, (meth)acrylic urethane, epoxy, and silicone. In addition, other examples of materials that make up the main components of the above film include glassy polymers such as siloxane polymers and polymer films described in Japanese Patent Application Publication No. 2001-343529 (WO01 / 37007). Furthermore, as the main component material of the above film, a resin composition containing a thermoplastic resin having substituted or unsubstituted imide groups in its side chains, and a thermoplastic resin having substituted or unsubstituted phenyl groups and nitrile groups in its side chains can also be used. For example, a resin composition having an alternating copolymer of isobutene and N-methylmaleimide and an acrylonitrile-styrene copolymer can be used, and the film may be, for example, an extruded product of such a resin composition.

[0050] One embodiment of the protective layer includes a (meth)acrylic resin. As the (meth)acrylic resin, for example, a (meth)acrylic resin having a glutarimide structure is used. A (meth)acrylic resin having a glutarimide structure is described, for example, in Japanese Patent Publication No. 2006-309033, 2006-317560, 2006-328329, 2006-328334, 2006-337491, 2006-337492, 2006-337493, 2006-337569, 2007-009182, 2009-161744, and 2010-284840. These statements are incorporated herein by reference.

[0051] The thickness of the protective layer can be any appropriate thickness as long as it does not impair the effects of the present invention. In order to better express the effects of the present invention, the thickness of the protective layer is typically 300 μm or less, preferably 3 μm to 100 μm, more preferably 5 μm to 80 μm, and even more preferably 10 μm to 60 μm. If the protective layer is surface-treated, the thickness of the protective layer includes the thickness of the layer formed by the surface treatment (surface-treated layer).

[0052] ≪1-3. First Adhesive Sheet≫ As shown in Figures 1 and 2, the first adhesive sheet 21 is positioned on the viewing side of the polarizing film 10, and the first optical member 31 may be attached to the first adhesive sheet 21 on the side opposite to the polarizing film 10 as seen from the first adhesive sheet 21.

[0053] As described above, the first adhesive sheet is formed from a photocurable first adhesive composition. More specifically, the first adhesive sheet is composed of a first adhesive formed from the first adhesive composition. The first adhesive composition can form the first adhesive by being irradiated with light.

[0054] Furthermore, compared to thermosetting adhesives, which primarily use heat to form adhesive sheets, photocurable adhesive compositions can reduce the amount of energy required for forming adhesive sheets, making them particularly preferable for environmental protection and sustainability. In addition, adhesive sheets formed from photocurable adhesive compositions have higher smoothness than adhesive sheets formed from thermosetting adhesive compositions, making them suitable for improving the visibility of image display devices.

[0055] The first adhesive composition includes, for example, a monomer component M1. A portion of the monomer component M1 may be a partially polymerized product. The content of monomer component M1 in the first adhesive composition is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 70% by weight or more, and particularly preferably 80% by weight or more.

[0056] The monomer component M1 preferably includes a (meth)acrylic monomer. Examples of (meth)acrylic monomers include alkyl (meth)acrylates. There may be only one alkyl (meth)acrylate or two or more alkyl (meth)acrylates. Typically, alkyl (meth)acrylates are alkyl (meth)acrylates in which the alkyl group of the alkyl ester portion has 1 to 20 carbon atoms. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 10, even more preferably 1 to 8, and particularly preferably 2 to 6. The alkyl group may be linear or branched. Specific examples of alkyl methacrylates include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Examples of alkyl esters (meth)acrylates include n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate (lauryl (meth)acrylate), n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, and octadecyl (meth)acrylate. Among these, n-butyl (meth)acrylate is preferred as the alkyl (meth)acrylate, and n-butyl acrylate is more preferred, in terms of being able to better express the effects of the present invention.

[0057] The content of alkyl (meth)acrylate in monomer component M1 is preferably 40% to 100% by weight, more preferably 50% to 99.9% by weight, even more preferably 55% to 99% by weight, and particularly preferably 60% to 99% by weight. In one embodiment, this content may be 65% to 99% by weight, 70% to 99% by weight, 75% to 99% by weight, 80% to 99% by weight, 85% to 99% by weight, 90% to 99% by weight, 91% to 99% by weight, 92% to 98% by weight, or 93% to 97% by weight. In another embodiment, this content may be 60% to 95% by weight, 65% to 90% by weight, 68% to 88% by weight, or 70% to 85% by weight.

[0058] The monomer component M1 preferably contains a nitrogen atom-containing monomer. A nitrogen atom-containing monomer means a monomer that has at least one nitrogen atom in its molecule (one molecule). There may be only one type of nitrogen atom-containing monomer, or there may be two or more types.

[0059] Examples of nitrogen atom-containing monomers include amide group-containing monomers. There may be only one amide group-containing monomer or two or more. An amide group-containing monomer is a compound that contains an amide group in its structure and also contains a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. The amide group-containing monomer is preferably an amide group-containing (meth)acrylate.

[0060] Examples of amide group-containing monomers include acrylamide monomers such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropylacrylamide, N-methyl(meth)acrylamide, N-butyl(meth)acrylamide, N-hexyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylol-N-propane(meth)acrylamide, aminomethyl(meth)acrylamide, aminoethyl(meth)acrylamide, mercaptomethyl(meth)acrylamide, and mercaptoethyl(meth)acrylamide; N-acryloyl heterocyclic monomers such as N-(meth)acryloylmorpholine, N-(meth)acryloylpiperidine, and N-(meth)acryloylpyrrolidine; and N-vinyl group-containing lactam monomers such as N-vinylpyrrolidone and N-vinyl-ε-caprolactam, with N-vinylpyrrolidone being preferred.

[0061] Nitrogen atom-containing monomers other than amide group-containing monomers include amino group-containing monomers such as (meth)aminoethyl acrylate, (meth)dimethylaminoethyl acrylate, (meth)dimethylaminopropyl acrylate, and (meth)butylaminoethyl acrylate; cyano group-containing monomers such as acrylonitrile and methacrylonitrile; (meth)acryloylmorpholine, N-vinylpiperazine, N-vinylpyrrole, N-vinylimidazole, N-vinylpyrazine, N-vinylmorpholine, N-vinylpyrazole, vinylpyridine, vinylpyrimidine, vinyloxazole, vinylisoxazole, vinylthiazole, vinylisothiazole, vinylpyridazine, (meth)acryloylpyrrolidone, (meth)acryloylpyrrolidine, (meth)acryloylpiperidine, and N-methylvinylpyrrolidone Examples include heterocyclic monomers such as: maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, and N-phenylmaleimide; itaconimide monomers such as N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-laurylitaconimide, and N-cyclohexylitaconimide; imide group-containing monomers of succinimide monomers such as N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, and N-(meth)acryloyl-8-oxyoctamethylenesuccinimide; and isocyanate group-containing monomers such as 2-(meth)acryloyloxyethyl isocyanate.

[0062] The content of nitrogen atom-containing monomers in monomer component M1 is, for example, 0% to 50% by weight. In one embodiment, this content may be 0.1% to 45% by weight, 0.1% to 40% by weight, 0.1% to 35% by weight, 0.1% to 30% by weight, 0.1% to 25% by weight, 1% to 20% by weight, 3% to 15% by weight, or 3% to 10% by weight.

[0063] Monomer component M1 may contain an aromatic ring-containing monomer. The aromatic ring-containing monomer may be one type or two or more types. The aromatic ring-containing monomer is a compound that contains an aromatic ring in its structure and also contains a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group.

[0064] Examples of aromatic ring-containing monomers include phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, ethylene oxide-modified nonylphenol (meth)acrylate, hydroxyethylated β-naphthol (meth)acrylate, and biphenyl (meth)acrylate, with benzyl (meth)acrylate being preferred and benzyl acrylate being more preferred. The content of aromatic ring-containing monomers in monomer component M1 is preferably 0% to 50% by weight, more preferably 1% to 30% by weight, even more preferably 5% to 25% by weight, particularly preferably 8% to 20% by weight, and most preferably 10% to 20% by weight.

[0065] Monomer component M1 may contain a carboxyl group-containing monomer. The carboxyl group-containing monomer may be one type or two or more types. The carboxyl group-containing monomer is a compound that contains a carboxyl group in its structure and also contains a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Examples of carboxyl group-containing monomers include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid, with (meth)acrylic acid being preferred and acrylic acid being more preferred. The content of the carboxyl group-containing monomer in monomer component M1 is preferably 0% to 10% by weight, more preferably 0.1% to 10% by weight, even more preferably 1% to 9% by weight, particularly preferably 2% to 8% by weight, and most preferably 3% to 7% by weight.

[0066] Monomer component M1 may contain a hydroxyl group-containing monomer. There may be only one hydroxyl group-containing monomer or two or more. A hydroxyl group-containing monomer is a compound that contains a hydroxyl group in its structure and also contains a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Examples of hydroxyl group-containing monomers include hydroxyl group-containing (meth)acrylates with 1 to 20 carbon atoms, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)-methyl acrylate, with 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate being preferred. The content of hydroxyl group-containing monomers in monomer component M1 is, for example, 0% to 20% by weight, may be 0% to 15% by weight, 0% to 10% by weight, 0% to 7% by weight, or 0% to 5% by weight.

[0067] Monomer component M1 may contain an ether group-containing monomer. There may be only one ether group-containing monomer or two or more. An ether group-containing monomer is a compound that contains an ether group in its structure and also contains a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Examples of ether group-containing monomers include alkoxy group-containing monomers. Examples of alkoxy group-containing monomers include alkylene oxide adducts shown in the following chemical formula (1). In chemical formula (1), R 1 R is a hydrogen atom or a methyl group, 2 R is an alkyl group. 2 It may be linear or branched, but is preferably linear. 2 Typical examples include the methyl group and the ethyl group. In chemical formula (1), n ​​is an integer from 1 to 30, preferably an integer from 1 to 12, and more preferably an integer from 1 to 5.

[0068] Specific examples of alkylene oxide adducts shown in chemical formula (1) include, for example, 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, and methoxypolyethylene glycol (meth)acrylate.

[0069] The ether group-containing monomer is not limited to the alkylene oxide adducts described above. The ether group-containing monomer may have a ring structure, and this ring structure may contain an ether group. Examples of ring structures containing an ether group include a tetrahydrofuran ring and a dioxane ring. Specific examples of ether group-containing monomers having a ring structure include cyclic trimethylolpropane formal (meth)acrylate and tetrahydrofurfuryl (meth)acrylate.

[0070] The content of the ether group-containing monomer in monomer component M1 is, for example, 0% to 20% by weight, may be 0% to 15% by weight, 0% to 10% by weight, 0% to 7% by weight, or 0% to 5% by weight.

[0071] The monomer component may contain other copolymer monomers. The other copolymer monomers may be one type or two or more types. Examples of other copolymer monomers include: acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; caprolactone adducts of acrylic acid; sulfonic acid group-containing monomers such as allyl sulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidepropanesulfonic acid, and sulfopropyl (meth)acrylate; phosphate group-containing monomers such as 2-hydroxyethyl acryloyl phosphate; vinyl monomers such as vinyl acetate and vinyl propionate; epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate; carbitol (meth)acrylate, ethyl carbitol (meth)acrylate, polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, Examples include glycol-based (meth)acrylates such as methoxypolypropylene glycol (meth)acrylate; (meth)acrylates such as tetrahydrofurfuryl (meth)acrylate, fluorine (meth)acrylate, and silicone (meth)acrylate; and silane monomers containing silicon atoms such as 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, and 10-acryloyloxydecyltriethoxysilane.

[0072] The content of other copolymer monomers in monomer component M1 is, for example, 0% to 10% by weight, may be 0% to 5% by weight, or 0% to 3% by weight.

[0073] The first adhesive composition may contain a partially polymerized monomer component M1. The partially polymerized monomer may be a monopolymer or a copolymer. The partially polymerized monomer may moderately increase the viscosity of the first adhesive composition, thereby contributing to the stable formation of the coating layer described later.

[0074] The first adhesive composition may contain a photopolymerization initiator. Any suitable photopolymerization initiator can be used as the photopolymerization initiator, as long as it does not impair the effects of the present invention. Examples of photopolymerization initiators include photoradical generators that generate radicals in response to visible light and / or ultraviolet light with wavelengths shorter than 450 nm. There may be only one type of photopolymerization initiator or two or more types.

[0075] Examples of photopolymerization initiators include α-ketol compounds such as 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, and 1-hydroxycyclohexylphenylketone; acetophenone compounds such as methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, and 2-methyl-1-[4-(methylthio)-phenyl]-2-morpholinopropane-1; benzoin ether compounds such as benzoin ethyl ether, benzoin isopropyl ether, and anisoin methyl ether; and ketal compounds such as benzyldimethyl ketal. Examples include: aromatic sulfonyl chloride compounds such as 2-naphthalenesulfonyl chloride; photoactive oxime compounds such as 1-phenone-1,1-propanedione-2-(o-ethoxycarbonyl)oxime; benzophenone compounds such as benzophenone, benzoylbenzoic acid, and 3,3'-dimethyl-4-methoxybenzophenone; thioxanthone compounds such as thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, and 2,4-diisopropylthioxanthone; camphorquinone; halogenated ketones; acylphosphinoxides; and acylphosphonates.

[0076] As a photopolymerization initiator, a photopolymerization initiator having two or more (preferably two to five) photodegradable groups may be used. A photodegradable group is a functional group that absorbs irradiated active energy rays and generates radicals. Specific examples include ketone groups, halogenated alkyl groups, ester groups, sulfone groups, and peroxy groups.

[0077] Examples of photopolymerization initiators having two or more photodegradable groups include 2-hydroxy-1-[4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]phenyl]-2-methylpropan-1-one (commercially available, for example, trade name "Omnirad127D", manufactured by IGM Resins B.V.), 1-[4-(4-benzoixylphenylsulfanyl)phenyl]-2-methyl-2-(4-methylphenylsulfonyl)propan-1-one (commercially available, for example, trade name "ESURE1001M"), methylbenzoylformate (commercially available, for example, trade name "SPEEDCURE MBF", manufactured by ARKEMA Sartomer), and o-ethoxyimino-1-phenylpropan-1-one (commercially available, for example, trade name "SPEEDCURE PDO", manufactured by ARKEMA Sartomer). Examples include Sartomer's oligo[2-hydroxy-2-methyl-4-(1-methylvinyl)phenyl]propanone (a commercially available product, for example, is sold under the trade name "ESCURE KIPI50" by LAMBERTI).

[0078] Compounds containing a phosphorus atom and / or a nitrogen atom may be used as photopolymerization initiators. Examples of such photopolymerization initiators include 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (commercially available, for example, trade name "Omnirad 907", manufactured by IGM Resins B.V.), 2-benzyl-2-(dimethylamino)-4'-morpholinobylophenone (commercially available, for example, trade name "Omnirad 369", manufactured by IGM Resins B.V.), and 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-ylphenyl)butan-1-one (commercially available, for example, trade name "Omnirad 379", manufactured by IGM Resins B.V. (Manufactured by IGM Resins B.V.), bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (commercially available, e.g., trade name "Omnirad819", manufactured by IGM Resins B.V.), 2,4,6-trimethylbenzoyl-diphenylphosphine oxide (commercially available, e.g., trade name "OmniradTPO", manufactured by IGM Resins B.V.), 1,2-octanedione-1-[4-(phenylthio)phenyl-2-(O-benzoyloxime)] (commercially available, e.g., trade name "OmniradOXE01", manufactured by IGM Resins B.V.) Examples include [etanone-morpholinopropane-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyloxime), manufactured by IGM Resins B.V. (a commercially available product is, for example, trade name "OmniradOXE02", manufactured by IGM Resins B.V.).

[0079] The amount of photopolymerization initiator in the first adhesive composition can be any appropriate amount, as long as it does not impair the effects of the present invention. The amount of such photopolymerization initiator is, for example, 0.02 parts by weight to 10 parts by weight, preferably 0.05 parts by weight to 5 parts by weight, per 100 parts by weight of monomer component M1.

[0080] The first adhesive composition may contain a crosslinking agent. The crosslinking agent may be one type or two or more types.

[0081] Examples of crosslinking agents include polyfunctional (meth)acrylates (such as ester compounds of polyhydric alcohols and (meth)acrylic acid), allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy (meth)acrylate, polyester (meth)acrylate, urethane (meth)acrylate, butyl di(meth)acrylate, and hexyl di(meth)acrylate.

[0082] Examples of polyfunctional (meth)acrylates include difunctional (meth)acrylates, trifunctional (meth)acrylates, and polyfunctional (meth)acrylates with four or more functions.

[0083] Examples of difunctional (meth)acrylates include (poly)ethylene glycol di(meth)acrylates such as ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, and tetraethylene glycol di(meth)acrylate; (poly)propylene glycol di(meth)acrylates such as propylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, and tetrapropylene glycol di(meth)acrylate; and neop Examples include ethyl glycol di(meth)acrylate; pentaerythritol di(meth)acrylate; 1,2-ethylene glycol di(meth)acrylate; 1,6-hexanediol di(meth)acrylate; 1,9-nonanediol diacrylate (NDDA); 1,12-dodecanediol di(meth)acrylate; glycerin di(meth)acrylate; stearic acid-modified pentaerythritol di(meth)acrylate; dicyclopentadienyl di(meth)acrylate; di(meth)acryloyl isocyanurate; and ethoxylated bisphenol A di(meth)acrylate.

[0084] Examples of trifunctional (meth)acrylates include pentaerythritol tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, and tris((meth)acryloyloxyethyl) isocyanurate.

[0085] Examples of polyfunctional (meth)acrylates with four or more functions include di(trimethylolpropane)tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol monohydroxypenta(meth)acrylate, and alkyl-modified dipentaerythritol penta(meth)acrylate.

[0086] One preferred embodiment of the polyfunctional (meth)acrylate is 1,9-nonanediol di(meth)acrylate (e.g., 1,9-nonanediol diacrylate (NDDA)) or di(trimethylolpropane)tetra(meth)acrylate. As for di(trimethylolpropane)tetra(meth)acrylate, a commercially available product such as "PHOTOMER 4306" (manufactured by IGM Resins B.V.) can be used.

[0087] As for epoxy (meth)acrylate, commercially available products such as "EBECRYL3700" (manufactured by Daicel Ornex Co., Ltd.) can be used.

[0088] As for polyester (meth)acrylate, commercially available products such as "PHOTOMER 5429" (manufactured by IGM Resins B.V.) can be used.

[0089] As for urethane (meth)acrylate, commercially available products such as "EBECRYL4859" (manufactured by Daicel Ornex Co., Ltd.) can be used.

[0090] A polyfunctional oligomer may be used as a crosslinking agent. Only one polyfunctional oligomer may be used, or two or more may be used. Examples of polyfunctional oligomers include urethane (meth)acrylate oligomers (oligomers having a urethane skeleton and two or more (meth)acryloyl groups), epoxy (meth)acrylate oligomers (oligomers having an epoxy skeleton and two or more (meth)acryloyl groups), and silicone (meth)acrylate oligomers (oligomers having a siloxane skeleton and two or more (meth)acryloyl groups). Preferably, a urethane (meth)acrylate oligomer is used as the polyfunctional oligomer. Examples of commercially available urethane (meth)acrylate oligomers include the product names "Art Resin UN-333", "Art Resin UN-350", "Art Resin UN-353", "Art Resin UN-5500", and "Art Resin UN-5590" manufactured by Negami Kogyo Co., Ltd.

[0091] The weight-average molecular weight (Mw) of the polyfunctional oligomer is, for example, 1,000 to 50,000, but may also be 5,000 to 40,000, 8,000 to 30,000, 11,000 to 25,000, 14,000 to 23,000, or 16,000 to 22,000. Such a configuration is preferred from the viewpoint of appropriately adjusting the viscoelasticity (e.g., shear storage modulus and loss tangent) of the base polymer. The weight-average molecular weight (Mw) as used herein is a value (polystyrene equivalent) based on GPC (gel permeation chromatography) measurements.

[0092] In order to better exhibit the effects of the present invention, it is preferable to select at least one from the group consisting of polyfunctional (meth)acrylate, epoxy (meth)acrylate, polyester (meth)acrylate, urethane (meth)acrylate, and polyfunctional oligomer as the crosslinking agent.

[0093] As a crosslinking agent, an isocyanate-based crosslinking agent may be used in combination with the above-mentioned crosslinking agent. Such an isocyanate-based crosslinking agent may be one type or two or more types. The content of the isocyanate-based crosslinking agent in the total amount of crosslinking agent is preferably 0% to 50% by weight, more preferably 0% to 30% by weight, even more preferably 0% to 10% by weight, particularly preferably 0% to 5% by weight, and most preferably 0% to 1% by weight.

[0094] Any suitable isocyanate crosslinking agent that is generally known can be used. As the isocyanate crosslinking agent, a compound having at least two isocyanate groups (isocyanate compound) can be used. Preferably, the number of isocyanate groups contained in the isocyanate compound is three or more. The upper limit of the number of isocyanate groups is not particularly limited, for example, five. Examples of isocyanate compounds include aromatic isocyanate compounds, alicyclic isocyanate compounds, and aliphatic isocyanate compounds.

[0095] Examples of aromatic isocyanate compounds include phenylenediisocyanate, 2,4-tolylenediisocyanate, 2,6-tolylenediisocyanate, 2,2'-diphenylmethanediisocyanate, 4,4'-diphenylmethanediisocyanate, 4,4'-toluidinediisocyanate, 4,4'-diphenyletherdiisocyanate, 4,4'-diphenyldiisocyanate, 1,5-naphthalenediisocyanate, and xylylenediisocyanate.

[0096] Examples of alicyclic isocyanate compounds include 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated tetramethylxylylene diisocyanate.

[0097] Examples of aliphatic isocyanate compounds include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI), 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, and 2,4,4-trimethylhexamethylene diisocyanate.

[0098] Examples of isocyanate-based crosslinking agents include polymers (dimers, trimers, pentamers, etc.) of the above-mentioned isocyanate compounds, adducts obtained by adding them to polyhydric alcohols such as trimethylolpropane, urea-modified compounds, biuret-modified compounds, allophanate-modified compounds, isocyanurate-modified compounds, carbodiimide-modified compounds, and urethane prepolymers obtained by adding them to polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, polyisoprene polyols, etc.

[0099] The isocyanate crosslinking agent may contain at least one derivative selected from alicyclic isocyanate compounds and aliphatic isocyanate compounds. It is particularly preferable that the isocyanate crosslinking agent is at least one selected from the group consisting of pentamethylene diisocyanate (PDI) crosslinking agents (PDI and its derivatives) and hexamethylene diisocyanate (HDI) crosslinking agents (HDI and its derivatives). Specific examples of PDI crosslinking agents include, for example, isocyanurate-modified PDI. Specific examples of HDI crosslinking agents include, for example, isocyanurate-modified HDI and biuret-modified HDI.

[0100] The amount of crosslinking agent in the first adhesive composition can be appropriately set based on the molecular weight, the number of functional groups, etc. In order to better express the effects of the present invention, the amount of crosslinking agent per 100 parts by weight of monomer component M1 is preferably 0.01 to 20 parts by weight. In one embodiment, this amount may be 0.05 to 10 parts by weight, 0.05 to 5 parts by weight, 0.05 to 3 parts by weight, 0.05 to 2 parts by weight, or 0.05 to 1.5 parts by weight. In another embodiment, this amount may be 0.01 to 10 parts by weight, 0.01 to 7 parts by weight, 0.01 to 5 parts by weight, 0.02 to 5 parts by weight, or 0.03 to 5 parts by weight.

[0101] When polyfunctional (meth)acrylate is used as a crosslinking agent, the content of polyfunctional (meth)acrylate relative to 100 parts by weight of monomer component M1 in the first adhesive composition is preferably 0.01 to 20 parts by weight, in order to better exhibit the effects of the present invention. In one embodiment, this content may be 0.05 to 10 parts by weight, 0.05 to 5 parts by weight, 0.05 to 3 parts by weight, 0.05 to 1 part by weight, or 0.05 to 0.5 parts by weight. In another embodiment, this content may be 0.01 to 10 parts by weight, 0.01 to 5 parts by weight, 0.01 to 1 part by weight, 0.01 to 0.5 parts by weight, or 0.01 to 0.1 parts by weight.

[0102] When at least one selected from the group consisting of epoxy (meth)acrylate, polyester (meth)acrylate, and urethane (meth)acrylate is used as the crosslinking agent, the content of the above crosslinking agent per 100 parts by weight of monomer component M1 in the first adhesive composition is preferably 0.01 to 20 parts by weight, more preferably 0.1 to 10 parts by weight, even more preferably 0.2 to 5 parts by weight, even more preferably 0.3 to 3 parts by weight, particularly preferably 0.3 to 2 parts by weight, and most preferably 0.4 to 1.5 parts by weight.

[0103] When a polyfunctional oligomer is used as a crosslinking agent, the content of the polyfunctional oligomer relative to 100 parts by weight of monomer component M1 in the first adhesive composition is preferably 0.01 to 20 parts by weight, but may also be 0.1 to 15 parts by weight, 0.5 to 10 parts by weight, or 1 to 5 parts by weight, in order to better express the effects of the present invention.

[0104] The first adhesive composition may contain any other suitable additives, as long as they do not impair the effects of the present invention. The other additives may be one or more. Examples of such other additives include chain transfer agents, silane coupling agents, viscosity modifiers, tackifiers, plasticizers, softeners, anti-aging agents, fillers, colorants, rust inhibitors, antioxidants, antistatic agents, ultraviolet absorbers, and solvents.

[0105] In one embodiment of the first adhesive composition, the amount of ultraviolet absorber per 100 parts by weight of monomer component M1 in the first adhesive composition is preferably 0 to 5 parts by weight, but may be 0 to 3 parts by weight, 0 to 2 parts by weight, 0 to 1 part by weight, or substantially 0 parts by weight.

[0106] The first adhesive composition may contain a solvent. The solvent content in the first adhesive composition may be, for example, 5% by weight or less, 4% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, or even 0.5% by weight or less. The adhesive composition may not contain a solvent substantially. Substantially solvent-free means that a solvent derived from additives, etc., may be permitted at a content of, for example, 0.1% by weight or less, preferably 0.05% by weight or less, and more preferably 0.01% by weight or less.

[0107] The viscosity of the first adhesive composition is, for example, 5 poise to 150 poise at 25°C.

[0108] The first adhesive sheet can be formed from the first adhesive composition by any suitable method, provided that the effects of the present invention are not impaired.

[0109] One embodiment of a method for forming a first adhesive sheet from a first adhesive composition is to prepare a laminate comprising, for example, a base sheet, a coating layer containing the first adhesive composition, and a release liner in that order, and then to cure the coating layer by irradiating the resulting laminate with light to form the first adhesive sheet. This yields a laminate comprising a base sheet, a first adhesive sheet, and a release liner in that order.

[0110] A laminate comprising a base sheet, a coating layer containing the first adhesive composition, and a release liner in this order can be manufactured by any suitable method without impairing the effects of the present invention. For example, such a manufacturing method involves applying the first adhesive composition onto a release liner and then laminating the base sheet onto the formed coating surface.

[0111] The base sheet may be in the form of a single leaf or a long length. Examples of base sheets include resin films. Examples of resins that make up the resin film include polyester such as polyethylene terephthalate, acetate resin, polyethersulfone, polycarbonate, polyamide, polyimide, polyolefin, (meth)acrylic resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl alcohol, polyarylate, and polyphenylene sulfide. Preferably, the resin that makes up the resin film is polyester such as polyethylene terephthalate.

[0112] The thickness of the base sheet can be any appropriate thickness as long as it does not impair the effects of the present invention. For example, such a thickness is 10 μm to 200 μm, and preferably 25 μm to 150 μm.

[0113] The base sheet may have a release layer on the side facing the coated layer. Any suitable release layer can be used as the release layer, as long as it does not impair the effects of the present invention. For example, a commonly known release layer can be used as such. Typically, such a release layer is a cured layer of a release agent composition containing a release agent. Various release agents can be used as the release agent, such as silicone-based release agents, fluorine-based release agents, long-chain alkyl-based release agents, fatty acid amide-based release agents, and silica powder. The thickness of the release layer can be any suitable thickness, as long as it does not impair the effects of the present invention. For example, such a thickness is 10 nm to 300 nm.

[0114] Examples of the base material for the release liner (hereinafter referred to as "liner base material") include a resin film. Examples of resins that make up the resin film include polyester such as polyethylene terephthalate, acetate resin, polyethersulfone, polycarbonate, polyamide, polyimide, polyolefin, (meth)acrylic resin, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl alcohol, polyarylate, and polyphenylene sulfide. Preferably, the resin that makes up the resin film is polyester such as polyethylene terephthalate. The thickness of the release liner is, for example, 10 μm to 200 μm.

[0115] The release liner may include layers other than the liner substrate. The release liner may include a release layer. For example, the release liner includes a liner substrate and a release layer formed on one side of the liner substrate. In the release liner, the release layer may be on the side of the coating layer.

[0116] The coating layer can be formed by any suitable method, provided that it does not impair the effects of the present invention. For example, the coating layer is formed by applying the first adhesive composition to the surface of the release liner (preferably on the side of the release layer if a release layer is provided). Various coating methods can be used, such as roll coating, kiss roll coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, lip coating, and die coating. After coating, heating and drying may be performed as needed.

[0117] The thickness of the coating layer can be adjusted according to the final thickness of the first adhesive sheet.

[0118] The light to be irradiated can be any suitable light under any suitable conditions, as long as it does not impair the effects of the present invention. The light to be irradiated is, for example, visible light or ultraviolet light having a wavelength shorter than 450 nm. The light source for the irradiated light is, for example, a light irradiation device equipped with an ultraviolet irradiation lamp. Examples of ultraviolet irradiation lamps include ultraviolet light LEDs, low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, xenon lamps, microwave-excited mercury lamps, black light lamps, chemical lamps, germicidal lamps, low-pressure discharge mercury lamps, and excimer lasers, and two or more ultraviolet irradiation lamps may be combined. The illuminance of the irradiated light is, for example, 1 mW / cm². 2 ~20 mW / cm² 2 The irradiation time of the light is, for example, 5 minutes to 5 hours. The integrated light intensity of the irradiated light is, for example, 100 mJ / cm². 2 ~5000mJ / cm 2 That is the case.

[0119] Another embodiment of the method for forming a first adhesive sheet from a first adhesive composition is to prepare a laminate comprising, for example, a base sheet, a coating layer containing the first adhesive composition, and a release liner in that order, cure the coating layer by irradiating the resulting laminate with light, peel off the release liner, apply an additive solution to the surface of the exposed cured layer, dry it as needed, then bond the release liner to the side with the additive solution coating, and irradiate the resulting laminate with light to form the first adhesive sheet. This yields a laminate comprising a base sheet, a first adhesive sheet, and a release liner in that order.

[0120] In this embodiment, instead of applying the additive solution to the surface of the exposed cured layer, drying it as necessary, and then attaching a release liner to the side where the additive solution was applied and curing it by irradiating it with light, the first optical member may be attached to the side where the additive solution was applied first, and light may be irradiated through the first optical member to form a first adhesive sheet. This results in a laminate containing the base sheet, the first adhesive sheet, and the first optical member in that order.

[0121] Any suitable light can be used as the light irradiated for curing, as long as it does not impair the effects of the present invention.

[0122] As the above-mentioned additives, any suitable additive can be used as long as it does not impair the effects of the present invention. Examples of such additives include at least one selected from the group consisting of photopolymerization initiators, crosslinking agents, monomer components, ultraviolet absorbers, rust inhibitors, and antistatic agents. There may be only one additive or two or more additives. Note that the additives referred to herein do not contain solvents. As described later, the additives can be used as an additive solution by mixing them with a solvent.

[0123] One preferred embodiment of the additive is at least one selected from the group consisting of photopolymerization initiators, crosslinking agents, and monomer components.

[0124] As the photopolymerization initiator that can be used as the additive described above, any suitable photopolymerization initiator can be used as long as it does not impair the effects of the present invention. Such photopolymerization initiators may be those described above. There may be only one type of photopolymerization initiator, or two or more types.

[0125] The amount of the photopolymerization initiator that can be used as an additive can be any appropriate amount as long as it does not impair the effects of the present invention. The amount of such photopolymerization initiator may be, for example, 0 to 15 parts by weight per 100 parts by weight of solids of the first adhesive composition, and may also be 0.01 to 10 parts by weight or 0.1 to 5 parts by weight.

[0126] One embodiment of the amount of photopolymerization initiator that can be used as an additive is, for example, 0 to 10 parts by weight, relative to 100 parts by weight of monomer component M1 in the first adhesive composition, and may be 0.01 to 10 parts by weight, 0.05 to 5 parts by weight, 0.1 to 3 parts by weight, or 0.3 to 1 part by weight.

[0127] As the crosslinking agent that can be used as the additive described above, any suitable crosslinking agent can be used as long as it does not impair the effects of the present invention. Such crosslinking agents may be those described above. There may be only one crosslinking agent, or two or more.

[0128] The amount of the crosslinking agent that can be used as an additive can be any appropriate amount as long as it does not impair the effects of the present invention. The amount of such crosslinking agent may be, for example, 0 to 40 parts by weight, 1 to 35 parts by weight, or 5 to 30 parts by weight, per 100 parts by weight of solid content of the first adhesive composition.

[0129] One embodiment of the amount of crosslinking agent that can be used as an additive is, for example, 0 to 100 parts by weight, 0.1 to 100 parts by weight, 1 to 70 parts by weight, 5 to 50 parts by weight, 10 to 40 parts by weight, or 15 to 35 parts by weight, relative to 100 parts by weight of monomer component M1 in the first adhesive composition.

[0130] As the monomer component that can be used as the additive described above, any suitable monomer component can be used as long as it does not impair the effects of the present invention. The description of monomer component M1 in the first adhesive composition described earlier can be used as an example of such a monomer component. There may be only one monomer component or two or more.

[0131] One embodiment of the amount of monomer component that can be used as an additive is, for example, 0 to 100 parts by weight, 0.1 to 100 parts by weight, 0.5 to 70 parts by weight, 1 to 50 parts by weight, 1.5 to 40 parts by weight, 2 to 35 parts by weight, 3 to 30 parts by weight, 4 to 25 parts by weight, or 5 to 20 parts by weight, relative to 100 parts by weight of monomer component M1 in the first adhesive composition.

[0132] UV absorbers may be used as the above-mentioned additives. However, UV absorbers may be omitted in order to better exhibit the effects of the present invention. Any suitable UV absorber can be used as such, as long as it does not impair the effects of the present invention. Examples of such UV absorbers include triazine-based UV absorbers, benzotriazole-based UV absorbers, benzophenone-based UV absorbers, oxybenzophenone-based UV absorbers, salicylate-based UV absorbers, and cyanoacrylate-based UV absorbers.

[0133] The ultraviolet absorber that can be used as an additive is preferably 0% to 5% by weight, 0% to 3% by weight, 0% to 2% by weight, 0% to 1% by weight, or substantially 0% by weight, based on 100 parts by weight of monomer component M1 in the first adhesive composition.

[0134] The amount of the above additive added per 100 parts by weight of the total amount of the first adhesive composition (typically the sum of monomer component M1, crosslinking agent, photopolymerization initiator, and other components as needed) is, for example, 1 to 100 parts by weight, may be 3 to 70 parts by weight, 5 to 50 parts by weight, 7 to 40 parts by weight, or 10 to 30 parts by weight.

[0135] As previously stated, the above-mentioned additives can be used as a solution of the additives. The solvent that can be used to make a solution of the additives may be one type or two or more types. Examples of such solvents include esters such as methyl acetate, ethyl acetate, isopropyl acetate, and butyl acetate; aromatic hydrocarbons such as toluene, xylene, and ethylbenzene; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone; aliphatic hydrocarbons such as hexane, heptane, and octane; alicyclic hydrocarbons such as cyclohexane; halogenated hydrocarbons such as chloroform, dichloromethane, and 1,2-dichloroethane; ethers such as diethyl ether, dimethoxyethane, tetrahydrofuran, and dioxane; amides such as N,N-dimethylformamide and N,N-dimethylacetamide; nitriles such as acetonitrile, propionitrile, and benzonitrile; and alcohols such as methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, sec-butanol, and tert-butanol.

[0136] The amount of the solvent can be any appropriate amount, as long as it does not impair the effects of the present invention.

[0137] Details of another embodiment of the method for forming a first adhesive sheet from the first adhesive composition described above are described, for example, in Japanese Patent Application Publication No. 2021-155733. The entire description of this publication is incorporated herein by reference.

[0138] ≪1-4. Second Adhesive Sheet≫ As shown in Figures 1 and 2, the second adhesive sheet 22 is positioned on the viewing side of the polarizing film 10, and the second optical member 32 may be attached to the second adhesive sheet 22 on the side opposite to the polarizing film 10 as seen from the second adhesive sheet 22.

[0139] As described above, the second adhesive sheet is formed from a photocurable second adhesive composition. More specifically, the second adhesive sheet is composed of a second adhesive formed from the second adhesive composition. The second adhesive composition can form the second adhesive by being irradiated with light.

[0140] The second adhesive composition includes, for example, a monomer component M2. A portion of the monomer component M2 may be a partially polymerized product. The content of monomer component M2 in the second adhesive composition is preferably 50% by weight or more, more preferably 60% by weight or more, even more preferably 70% by weight or more, and particularly preferably 80% by weight or more.

[0141] The monomer component M2 preferably includes a (meth)acrylic monomer. Examples of (meth)acrylic monomers include alkyl (meth)acrylates. For examples of alkyl (meth)acrylates and the content ratio of alkyl (meth)acrylates in monomer component M2, refer to the explanation in section 1-3. First Adhesive Sheet.

[0142] The monomer component M2 may contain monomers other than alkyl (meth)acrylate. Examples of other monomers and the proportion of other monomers in monomer component M2 can be found in the explanation in section 1-3. First Adhesive Sheet. It is preferable that monomer component M2 contains a nitrogen atom-containing monomer as the other monomer.

[0143] The second adhesive composition may contain a partially polymerized monomer component M2. The partially polymerized monomer may be either a monopolymer or a copolymer. The partially polymerized monomer can contribute to the stable formation of the coating layer described later by moderately increasing the viscosity of the second adhesive composition.

[0144] The second adhesive composition may contain a photopolymerization initiator. Examples of photopolymerization initiators and the content of photopolymerization initiators in the second adhesive composition can be found by referring to the explanation in section 1-3. First Adhesive Sheet.

[0145] The second adhesive composition may contain a crosslinking agent. Examples of crosslinking agents and the content of crosslinking agents in the second adhesive composition can be found by referring to the explanation in section 1-3. First Adhesive Sheet.

[0146] The second adhesive composition may contain other additives. Examples of other additives and the content of other additives in the second adhesive composition can be found by referring to the explanation in section 1-3. First Adhesive Sheet.

[0147] The composition of the second adhesive composition may be the same as or different from the composition of the first adhesive composition.

[0148] The viscosity of the second adhesive composition is, for example, 5 poise to 150 poise at 25°C.

[0149] The second adhesive sheet can be formed from the second adhesive composition by any suitable method, provided that the effects of the present invention are not impaired. The method for forming the second adhesive sheet from the second adhesive composition can be described by referring to the explanation in section 1-3. First Adhesive Sheet.

[0150] ≪1-5. Third Adhesive Sheet≫ As shown in Figure 2, the third adhesive sheet 23 is positioned on the viewing side of the polarizing film 10, and the third optical member 33 may be attached to the third adhesive sheet 23 on the side opposite to the polarizing film 10 as seen from the third adhesive sheet 23.

[0151] As the third adhesive sheet, any suitable adhesive sheet can be used as long as it does not impair the effects of the present invention. Preferably, the third adhesive sheet is formed from a thermosetting (solvent-type) third adhesive composition. More specifically, the third adhesive sheet is composed of a third adhesive formed from the third adhesive composition. The third adhesive composition can be formed, for example, by utilizing heat.

[0152] The third adhesive composition typically comprises a base polymer and a crosslinking agent. Examples of adhesives that constitute the third adhesive sheet obtained from the third adhesive composition include acrylic adhesives, polyester adhesives, rubber adhesives, vinyl alkyl ether adhesives, silicone adhesives, polyamide adhesives, urethane adhesives, fluorine adhesives, epoxy adhesives, and polyether adhesives.

[0153] The following explanation will describe a typical example where the adhesive constituting the third adhesive sheet is an acrylic adhesive, but the adhesive constituting the third adhesive sheet is not limited to this.

[0154] The acrylic adhesive composition that forms the acrylic adhesive preferably contains an acrylic polymer and a crosslinking agent, in that it can better exhibit the effects of the present invention.

[0155] Acrylic polymers can be referred to as so-called base polymers in the field of acrylic adhesives. There may be only one type of acrylic polymer, or two or more types.

[0156] The content of acrylic polymer in the acrylic adhesive composition is preferably 50% to 99.9% by weight, more preferably 60% to 99.5% by weight, even more preferably 70% to 99% by weight, particularly preferably 80% to 99% by weight, and most preferably 90% to 99% by weight, based on solid content.

[0157] As the acrylic polymer, any suitable acrylic polymer can be used, as long as it does not impair the effects of the present invention.

[0158] The weight-average molecular weight (Mw) of the acrylic polymer is preferably 100,000 to 3,000,000, more preferably 150,000 to 2,000,000, even more preferably 200,000 to 1,500,000, and particularly preferably 250,000 to 1,000,000. The weight-average molecular weight (Mw) as used herein is a value (polystyrene equivalent) based on GPC (gel permeation chromatography) measurements.

[0159] The glass transition temperature (Tg) of the acrylic polymer is preferably -100°C to 30°C, more preferably -95°C to 20°C, even more preferably -90°C to 10°C, and particularly preferably -80°C to 0°C.

[0160] Acrylic polymers can typically be obtained by polymerization of monomer compositions containing alkyl (meth)acrylates. That is, acrylic polymers can typically have constituent units derived from alkyl (meth)acrylates. There may be only one alkyl (meth)acrylate or two or more. Typically, alkyl (meth)acrylates are alkyl (meth)acrylates in which the alkyl group of the alkyl ester portion has 1 to 20 carbon atoms. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 10, even more preferably 1 to 8, and particularly preferably 2 to 6. The alkyl group may be linear or branched.

[0161] Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Examples include acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate (lauryl (meth)acrylate), n-tridecyl (meth)acrylate, n-tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, and octadecyl (meth)acrylate.

[0162] The content of constituent units derived from alkyl (meth)acrylate in the total constituent units of the acrylic polymer is preferably 50% by weight or more, more preferably 60% to 100% by weight, even more preferably 70% to 100% by weight, and particularly preferably 80% to 100% by weight. The content of alkyl (meth)acrylate in the monomer composition is preferably 50% by weight or more, more preferably 60% to 100% by weight, even more preferably 70% to 100% by weight, and particularly preferably 80% to 100% by weight.

[0163] Acrylic polymers may have structural units other than those derived from alkyl (meth)acrylates. Such structural units are derived from other monomers copolymerizable with alkyl (meth)acrylates.

[0164] Other monomers include, for example, aromatic ring-containing monomers, hydroxyl group-containing monomers, carboxyl group-containing monomers, amino group-containing monomers, amide group-containing monomers, polyfunctional monomers, and other copolymerizable monomers. These other monomers may be one type or two or more types.

[0165] Examples of aromatic ring-containing monomers include phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, ethylene oxide-modified nonylphenol (meth)acrylate, hydroxyethylated β-naphthol (meth)acrylate, and biphenyl (meth)acrylate.

[0166] The content of constituent units derived from aromatic ring-containing monomers in all constituent units of the acrylic polymer is preferably 0% to 50% by weight, more preferably 1% to 30% by weight, even more preferably 5% to 25% by weight, particularly preferably 8% to 20% by weight, and most preferably 10% to 18% by weight. The content of aromatic ring-containing monomers in the monomer composition is preferably 0% to 50% by weight, more preferably 1% to 30% by weight, even more preferably 5% to 25% by weight, particularly preferably 8% to 20% by weight, and most preferably 10% to 18% by weight.

[0167] Examples of hydroxyl group-containing monomers include hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate, as well as (4-hydroxymethylcyclohexyl)-methyl acrylate.

[0168] The content of constituent units derived from hydroxyl group-containing monomers in all constituent units of the acrylic polymer is preferably 0% to 20% by weight, more preferably 0% to 10% by weight, even more preferably 0% to 5% by weight, particularly preferably 0% to 3% by weight, and most preferably 0% to 1% by weight. The content of hydroxyl group-containing monomers in the monomer composition is preferably 0% to 20% by weight, more preferably 0% to 10% by weight, even more preferably 0% to 5% by weight, particularly preferably 0% to 3% by weight, and most preferably 0% to 1% by weight.

[0169] Examples of monomers containing a carboxyl group include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid.

[0170] Examples of amino group-containing monomers include N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate.

[0171] Examples of amide group-containing monomers include acrylamide monomers such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropylacrylamide, N-methyl(meth)acrylamide, N-butyl(meth)acrylamide, N-hexyl(meth)acrylamide, N-methylol(meth)acrylamide, N-methylol-N-propane(meth)acrylamide, aminomethyl(meth)acrylamide, aminoethyl(meth)acrylamide, mercaptomethyl(meth)acrylamide, and mercaptoethyl(meth)acrylamide; N-acryloyl heterocyclic monomers such as N-(meth)acryloylmorpholine, N-(meth)acryloylpiperidine, and N-(meth)acryloylpyrrolidine; N-vinylpyrrolidone; and N-vinyl group-containing lactam monomers such as N-vinyl-ε-caprolactam.

[0172] Examples of polyfunctional monomers include polyfunctional acrylates such as hexanediol di(meth)acrylate (1,6-hexanediol di(meth)acrylate), butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, allyl(meth)acrylate, vinyl(meth)acrylate, epoxy acrylate, polyester acrylate, and urethane acrylate; and divinylbenzene.

[0173] The total content of carboxyl group-containing monomers, amino group-containing monomers, amide group-containing monomers, and polyfunctional monomers in the total constituent units of the acrylic polymer is preferably 0% to 20% by weight, more preferably 0% to 10% by weight, even more preferably 0% to 8% by weight, particularly preferably 0% to 5% by weight, and most preferably 0% to 3% by weight. The total content of carboxyl group-containing monomers, amino group-containing monomers, amide group-containing monomers, and polyfunctional monomers in the monomer composition is preferably 0% to 20% by weight, more preferably 0% to 10% by weight, even more preferably 0% to 8% by weight, particularly preferably 0% to 5% by weight, and most preferably 0% to 3% by weight.

[0174] Other copolymerizable monomers include, for example, alkoxyalkyl esters of (meth)acrylates such as 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, methoxytriethylene glycol (meth)acrylate, 3-methoxypropyl (meth)acrylate, 3-ethoxypropyl (meth)acrylate, 4-methoxybutyl (meth)acrylate, and 4-ethoxybutyl (meth)acrylate; epoxy group-containing monomers such as glycidyl (meth)acrylate and methylglycidyl (meth)acrylate; sulfonic acid group-containing monomers such as sodium vinyl sulfonate; phosphate group-containing monomers; alicyclic hydrocarbon group-containing (meth)acrylate esters such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, and isobornyl (meth)acrylate; vinyl esters such as vinyl acetate and vinyl propionate; aromatic vinyl compounds such as styrene and vinyltoluene; olefins or dienes such as ethylene, propylene, butadiene, isoprene, and isobutylene; vinyl ethers such as vinyl alkyl ethers; and vinyl chloride.

[0175] The content of constituent units derived from other copolymerizable monomers in the total constituent units of the acrylic polymer is preferably 0% to 20% by weight, more preferably 0% to 10% by weight, even more preferably 0% to 5% by weight, particularly preferably 0% to 3% by weight, and most preferably 0% to 1% by weight. The content of other copolymerizable monomers in the monomer composition is preferably 0% to 20% by weight, more preferably 0% to 10% by weight, even more preferably 0% to 5% by weight, particularly preferably 0% to 3% by weight, and most preferably 0% to 1% by weight.

[0176] Acrylic polymers can be obtained by polymerization of monomer components. Examples of polymerization methods include solution polymerization, emulsion polymerization, bulk polymerization, thermal polymerization, and active energy ray polymerization, with solution polymerization and active energy ray polymerization being preferred.

[0177] Examples of solvents used in solution polymerization include esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; and ketones such as methyl ethyl ketone and methyl isobutyl ketone. The solvent may be a single solvent or two or more solvents.

[0178] Polymerization initiators may be used in the polymerization of monomer components. The type of polymerization initiator can be appropriately selected depending on the polymerization reaction, and may include, for example, thermal polymerization initiators and photopolymerization initiators.

[0179] Polymerization initiators used in solution polymerization include, for example, azo polymerization initiators, peroxide polymerization initiators, and redox polymerization initiators. Peroxide polymerization initiators include, for example, dibenzoyl peroxide and t-butyl permaleate. Among these, the azo polymerization initiator disclosed in Japanese Patent Application Publication No. 2002-69411 is preferred. Examples of azo polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis(2-methylpropionic acid)dimethyl, and 4,4'-azobis-4-cyanovaleric acid. The amount of polymerization initiator used is preferably 0.05 to 0.5 parts by weight, and more preferably 0.1 to 0.3 parts by weight, per 100 parts by weight of the total amount of monomer components.

[0180] Active energy rays used in active energy ray polymerization include ionizing radiation such as alpha rays, beta rays, gamma rays, neutron rays, and electron beams, as well as ultraviolet rays, with ultraviolet rays being preferred. Polymerization by irradiation with ultraviolet rays is also called photopolymerization. The polymerization system for active energy ray polymerization typically includes a photopolymerization initiator.

[0181] Examples of photopolymerization initiators include benzoin ether-based photopolymerization initiators, acetophenone-based photopolymerization initiators, α-ketol-based photopolymerization initiators, aromatic sulfonyl chloride-based photopolymerization initiators, photoactive oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, and thioxanthone-based photopolymerization initiators.

[0182] Examples of benzoin ether-based photopolymerization initiators include benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2,2-dimethoxy-1,2-diphenylethane-1-one, and anisole methyl ether. Examples of acetophenone-based photopolymerization initiators include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenyl ketone, 4-phenoxydichloroacetophenone, and 4-(t-butyl)dichloroacetophenone. Examples of α-ketol-based photopolymerization initiators include 2-methyl-2-hydroxypropiophenone and 1-[4-(2-hydroxyethyl)phenyl]-2-methylpropan-1-one. Examples of aromatic sulfonyl chloride-based photopolymerization initiators include 2-naphthalenesulfonyl chloride. Examples of photoactive oxime-based photopolymerization initiators include 1-phenyl-1,1-propanedione-2-(o-ethoxycarbonyl)-oxime. Examples of benzoin-based photopolymerization initiators include benzoin. Examples of benzyl-based photopolymerization initiators include benzyl. Examples of benzophenone-based photopolymerization initiators include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, polyvinylbenzophenone, and α-hydroxycyclohexylphenyl ketone. Examples of ketal-based photopolymerization initiators include benzyldimethylketal. Examples of thioxanthone-based photopolymerization initiators include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-diisopropylthioxanthone, and dodecylthioxanthone.

[0183] The amount of photopolymerization initiator used is preferably 0.01 to 1 part by weight, and more preferably 0.05 to 0.5 parts by weight, per 100 parts by weight of the total amount of monomer components.

[0184] Examples of crosslinking agents include polyfunctional isocyanate crosslinking agents, epoxy crosslinking agents, melamine crosslinking agents, peroxide crosslinking agents, as well as urea crosslinking agents, metal alkoxide crosslinking agents, metal chelate crosslinking agents, metal salt crosslinking agents, carbodiimide crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, and amine crosslinking agents. Among these, polyfunctional isocyanate crosslinking agents are preferred in that they can better exhibit the effects of the present invention.

[0185] Examples of polyfunctional isocyanate crosslinking agents include lower aliphatic polyisocyanates such as 1,2-ethylene diisocyanate, 1,4-butylene diisocyanate, and 1,6-hexamethylene diisocyanate; alicyclic polyisocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated xylene diisocyanate; and aromatic polyisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate. Examples of polyfunctional isocyanate crosslinking agents include commercially available products such as trimethylolpropane / tolylene diisocyanate adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate L"), trimethylolpropane / hexamethylene diisocyanate adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name "Coronate HL"), trade name "Coronate HX" (manufactured by Nippon Polyurethane Industry Co., Ltd.), and trimethylolpropane / xylylene diisocyanate adduct (manufactured by Mitsui Chemicals, Inc., trade name "Takenate 110N").

[0186] Examples of epoxy crosslinking agents (polyfunctional epoxy compounds) include N,N,N',N'-tetraglycidyl-m-xylenediline, diglycidylaniline, 1,3-bis(N,N-diglycidylaminomethyl)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 Examples of epoxy crosslinking agents include diglycidyl ethers, glycerol polyglycidyl ethers, pentaerythritol polyglycidyl ethers, polyglycerol polyglycidyl ethers, sorbitan polyglycidyl ethers, trimethylolpropane polyglycidyl ethers, diglycidyl adipate esters, diglycidyl o-phthalate esters, triglycidyl-tris(2-hydroxyethyl) isocyanurate, resorcinol diglycidyl ethers, bisphenol-S-diglycidyl ethers, and epoxy resins having two or more epoxy groups in the molecule. Commercially available epoxy crosslinking agents include the trade name "Tetrad C" (manufactured by Mitsubishi Gas Chemical Company, Inc.).

[0187] The amount of crosslinking agent in the acrylic adhesive composition can be any appropriate amount, as long as it does not impair the effects of the present invention. For example, in order to better express the effects of the present invention, the amount is preferably 0.1 to 30 parts by weight, more preferably 0.1 to 10 parts by weight, even more preferably 0.1 to 5.0 parts by weight, even more preferably 0.2 to 4.5 parts by weight, particularly preferably 0.3 to 4.0 parts by weight, and most preferably 0.4 to 3.5 parts by weight, relative to the solid content (100 parts by weight) of the acrylic polymer.

[0188] The acrylic adhesive composition may contain any other suitable components as long as they do not impair the effects of the present invention. Examples of such other components include polymer components other than acrylic polymers, crosslinking accelerators, crosslinking catalysts, silane coupling agents, tackifying resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), anti-aging agents, inorganic fillers, organic fillers, metal powders, colorants (pigments, dyes, etc.), foils, UV absorbers, antioxidants, light stabilizers, chain transfer agents, plasticizers, softeners, surfactants, antistatic agents, conductive agents, stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, lubricants, solvents, catalysts, and the like.

[0189] The solid content concentration of the acrylic adhesive composition is, for example, 5% to 50% by weight, preferably 10% to 40% by weight.

[0190] The third adhesive sheet can be formed from the acrylic adhesive composition by any suitable method, as long as it does not impair the effects of the present invention.

[0191] One embodiment of a method for forming a third adhesive sheet from an acrylic adhesive composition is to apply the acrylic adhesive composition to a base sheet to form a coating layer, dry the resulting coating layer, and then form a third adhesive sheet. This yields a laminate containing the base sheet and the third adhesive sheet in that order.

[0192] As the base sheet, for example, a release film can be used. Examples of materials that make up the release film include porous materials such as plastic film, paper, cloth, and nonwoven fabric; nets; foamed sheets; metal foils; and laminates thereof.

[0193] Examples of plastic films include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene-vinyl acetate copolymer film.

[0194] The thickness of the release film is, for example, 5 μm to 200 μm, preferably about 5 μm to 100 μm. The release film may be treated with various release agents, such as silicone-based release agents, fluorine-based release agents, long-chain alkyl-based release agents, fatty acid amide-based release agents, and silica powder.

[0195] Methods for applying acrylic adhesive compositions to a substrate sheet include, for example, roll coating, kiss roll coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, lip coating, and die coating by extrusion. The amount applied can be adjusted as appropriate depending on the purpose.

[0196] By drying the coating layer, the coating layer hardens and a third adhesive sheet is formed. The drying temperature of the coating layer can be any suitable temperature within a range that does not impair the effects of the present invention. Such drying temperatures are, for example, 30°C to 130°C, preferably 50°C to 125°C, more preferably 60°C to 120°C, even more preferably 70°C to 110°C, and particularly preferably 80°C to 100°C.

[0197] The drying time of the coated layer can be any appropriate drying time within a range that does not impair the effects of the present invention. For example, such a drying time is 10 seconds to 1000 seconds, preferably 30 seconds to 300 seconds, more preferably 40 seconds to 240 seconds, and particularly preferably 60 seconds to 180 seconds.

[0198] Furthermore, the third adhesive sheet is not limited to being formed from a thermosetting third adhesive composition. The third adhesive sheet may also be formed from a photocuring adhesive composition. For the photocuring adhesive composition, refer to the description of the first adhesive composition in section 1-3. First Adhesive Sheet.

[0199] The thickness of the third adhesive sheet can be any appropriate thickness as long as it does not impair the effects of the present invention. In terms of better exhibiting the effects of the present invention, the thickness of the third adhesive sheet is preferably 5 μm to 20 μm, more preferably 5 μm to 17 μm, even more preferably 5 μm to 16 μm, particularly preferably 5 μm to 15 μm, and most preferably 5 μm to 14 μm.

[0200] ≪1-6. First Optical Component≫ As the first optical component, any suitable optical component can be used, provided that it is a component capable of imparting optical functionality to the optical laminate according to the embodiment of the present invention, as long as it does not impair the effects of the present invention. Examples of such optical components include anti-reflective laminates and sunglasses-resistant laminates. The first optical component preferably has a hard coat layer, which will be described later.

[0201] The thickness of the first optical element is typically 40 μm to 120 μm, and preferably 70 μm to 100 μm.

[0202] One embodiment of the first optical component is an anti-reflective laminate. The anti-reflective laminate typically includes a first substrate, a hard coat layer disposed on the viewing side of the first substrate, and an anti-reflective layer disposed on the viewing side of the hard coat layer. The hard coat layer may be formed directly on the viewing side surface of the first substrate. The anti-reflective layer may be formed directly on the viewing side surface of the hard coat layer. The anti-reflective laminate may be a component with a laminated structure of anti-reflective layer / hard coat layer / first substrate. In the anti-reflective laminate, the first substrate is laminated with a first adhesive sheet.

[0203] <1-6-a. First Substrate> The first substrate is typically used to form a hard coat layer and an anti-reflective layer. Any suitable resin film can be used as the first substrate. Examples of materials for forming the first substrate include polyester resins such as polyethylene terephthalate (PET), cycloolefin resins such as norbornene resins, resins obtained by addition polymerization of cycloolefins (e.g., norbornene) and α-olefins (e.g., ethylene) (COC), and cellulose resins such as triacetylcellulose (TAC). One embodiment of the first substrate includes a cellulose resin such as TAC.

[0204] The thickness of the first substrate can be appropriately set depending on the purpose. Typically, the thickness of the first substrate is 20 μm to 200 μm, preferably 50 μm to 150 μm, and more preferably 70 μm to 90 μm.

[0205] <1-6-b. Hard Coat Layer> The hard coat layer can, for example, impart excellent pencil hardness to the optical laminate. Furthermore, by appropriately adjusting the refractive index difference between the hard coat layer and the anti-reflective layer, the reflectivity of the optical laminate can be further reduced.

[0206] The hard coat layer preferably has sufficient surface hardness, excellent mechanical strength, and excellent light transmittance. The hard coat layer can be formed from any suitable resin, as long as it has these desired properties. Specific examples of resins include thermosetting resins, thermoplastic resins, UV-curable resins, electron beam-curable resins, and two-component mixed resins. Among the resins used to form the hard coat layer, UV-curable resins are preferred. When the resin is UV-curable, the hard coat layer can be formed with simple operation and high efficiency.

[0207] Specific examples of UV-curable resins include, for example, polyester-based, acrylic-based, urethane-based, amide-based, silicone-based, and epoxy-based UV-curable resins. UV-curable resins include UV-curable monomers, oligomers, and polymers. Preferred UV-curable resins include resin compositions containing acrylic monomer or oligomer components having preferably two or more, more preferably three to six, UV-polymerizable functional groups. Typically, UV-curable resins contain photopolymerization initiators.

[0208] The hard coat layer can be formed by any suitable method. For example, the hard coat layer can be formed by coating a hard coat layer forming resin composition onto a first substrate, drying it, and curing the dried coating film by irradiating it with ultraviolet light.

[0209] The thickness of the hard coat layer is, for example, 0.5 μm to 20 μm, preferably 1 μm to 15 μm. The thickness of the hard coat layer may also be 5 μm to 20 μm.

[0210] The indentation modulus of the hard coat layer is, for example, 1 GPa or more, and may be 3 GPa or more, 5 GPa or more, 8 GPa or more, or even 10 GPa or more. The higher the indentation modulus of the hard coat layer, the higher the pencil hardness of the optical laminate tends to be. The upper limit of the indentation modulus of the hard coat layer is not particularly limited, and may be, for example, 20 GPa or less, 15 GPa or less, or even 13 GPa or less.

[0211] The indentation modulus of a hard coat layer can be measured, for example, by the following method. First, an anti-reflective laminate embedded in embedding resin is cut along the thickness direction with an ultramicrotome to obtain a sample for measurement. Next, the sample is fixed with the cross-section facing upwards on the stage of a nanoindenter (for example, Bruker's "TI950 TriboIndenter"). Then, under a measurement environment of 23°C and 50% relative humidity, a Birkovich (triangular pyramidal) type diamond indenter (radius of curvature of the tip: 0.1 μm) is used to gradually apply a load from the surface of the central part of the hard coat layer in the thickness direction of the cross-section of the sample, and after reaching the maximum load, the load is gradually reduced to 0. The indentation modulus Er at a depth of approximately 200 nm is calculated using the following formula (1), and the obtained calculated value can be considered as the indentation modulus of the hard coat layer. Er = (S√π) / (2√A) (1)

[0212] In formula (1) above, S represents the slope of the unloading curve, π represents pi, and A represents the projected contact area between the indenter and the sample. The projected contact area A between the indenter and the sample can be determined by the method described in Japanese Patent Application Publication No. 2005-195357.

[0213] Details regarding the hard coat layer and the adhesion structure between the hard coat layer and the anti-reflective layer are described, for example, in Japanese Patent Application Publication No. 2016-224443, the description of which is incorporated herein by reference.

[0214] <1-6-c. Anti-reflective layer> An anti-reflective layer is provided to prevent reflection of external light (e.g., fluorescent lamps). Any appropriate configuration can be adopted for the anti-reflective layer. Typical configurations of an anti-reflective layer include, for example, (1) a single layer of low refractive index layer with an optical film thickness of 120 nm to 140 nm and a refractive index of about 1.35 to 1.55; (2) a laminate having a medium refractive index layer, a high refractive index layer and a low refractive index layer in order from the first substrate; and (3) an alternating multilayer laminate of high refractive index layers and low refractive index layers.

[0215] Examples of materials that can form a low refractive index layer include silicon dioxide (SiO2) and magnesium fluoride (MgF2). The refractive index of the low refractive index layer is typically around 1.35 to 1.55. Examples of materials that can form a high refractive index layer include titanium dioxide (TiO2), niobium oxide (Nb2O3 or Nb2O5), tin-doped indium oxide (ITO), antimond-doped tin oxide (ATO), and ZrO2-TiO2. The refractive index of the high refractive index layer is typically around 1.60 to 2.20. Examples of materials that can form a medium refractive index layer include titanium dioxide (TiO2) and mixtures of materials that can form a low refractive index layer and materials that can form a high refractive index layer (for example, a mixture of titanium dioxide and silicon dioxide). The refractive index of the medium refractive index layer is typically around 1.50 to 1.85. The thicknesses of the low refractive index layer, medium refractive index layer, and high refractive index layer can be set to achieve an appropriate optical film thickness according to the layer structure of the anti-reflective layer, the desired anti-reflective performance, etc.

[0216] Anti-reflective layers are typically formed by dry processes. Specific examples of dry processes include PVD (Physical Vapor Deposition) and CVD (Chemical Vapor Deposition). Examples of PVD methods include vacuum deposition, reactive deposition, ion beam assisted deposition, sputtering, and ion plating. An example of a CVD method is plasma CVD. The dry process for forming the anti-reflective layer is preferably sputtering.

[0217] The thickness of the anti-reflective layer is, for example, about 20 nm to 300 nm.

[0218] The anti-reflective layer preferably has a difference of 2.0% or less, more preferably 1.9% or less, and even more preferably 1.8% or less between its maximum and minimum reflectance in the wavelength range of 400 nm to 700 nm. When the difference between the maximum and minimum reflectance is within this range, the coloration of reflected light can be effectively prevented.

[0219] The antireflection layer is typically located on the outermost surface on the visible side of the optical laminate. The moisture permeability of the antireflection layer is typically 1.0 g / mm 2 or less, preferably 0.01 g / mm 2 to 0.1 g / mm 2 . The moisture permeability can be measured as the amount of water vapor (g) passing through a sample with an area of 1 m 2 in 24 hours in an atmosphere of a temperature of 40°C and a humidity of 92% RH in accordance with the moisture permeability test (cup method) of JIS Z0208. If the moisture permeability of the antireflection layer located on the outermost surface is below the above upper limit, the warping of the optical laminate in a high-humidity environment can be more stably suppressed.

[0220] The antireflection layer does not necessarily have to be located on the outermost surface of the optical laminate. The antireflection laminate may be provided with an outermost surface layer on the visible side of the antireflection layer, if necessary. That is, the antireflection laminate may be composed of a first base material, a hard coat layer, an antireflection layer, and an outermost surface layer. The range of the moisture permeability of the outermost surface layer is the same as the range of the moisture permeability of the above-described antireflection layer. Examples of the outermost surface layer include an antifouling layer. The antifouling layer contains, for example, a fluorine group-containing silane compound (e.g., an alkoxysilane compound having a perfluoropolyether group) or a fluorine group-containing organic compound. The antifouling layer preferably exhibits water repellency with a water contact angle of 110 degrees or more.

[0221] ≪1-7. Second optical member≫ The second optical member may employ any appropriate optical member as long as the effects of the present invention are not impaired. The second optical member is typically a member that can impart excellent resistance to local loads to the optical laminate according to an embodiment of the present invention.

[0222] When the optical laminate according to an embodiment of the present invention has the configuration shown in FIG. 1, the second optical member 32 is bonded, for example, to the visible side of the polarizing film 10 via the second adhesive sheet 22. The second optical member 32 is disposed between the first adhesive sheet 21 and the second adhesive sheet 22. The second optical member 32 is in contact with the first adhesive sheet 21 and the second adhesive sheet 22 and may be pressure-sensitive adhered to the first adhesive sheet 21 and the second adhesive sheet 22.

[0223] In the configuration shown in Figure 2 for the optical laminate according to an embodiment of the present invention, the second optical member 32 is bonded to the viewing side of the third optical member 33 via the second adhesive sheet 22. The second optical member 32 is positioned between the first adhesive sheet 21 and the second adhesive sheet 22. The second optical member 32 is in contact with the first adhesive sheet 21 and the second adhesive sheet 22, and may be pressure-sensitively bonded to the first adhesive sheet 21 and the second adhesive sheet 22.

[0224] The second optical member is formed from any suitable film. Specific examples of the main component material of the second optical member include, for example, the same materials as the main component material of the protective layer described in section <1-2-b. Protective Layer> (the transparent resin, the thermosetting resin or UV-curing resin, the glassy polymer, and the resin composition described above). In one embodiment of the present invention, the second optical member includes a (meth)acrylic resin, preferably a (meth)acrylic resin having a glutarimide structure. That is, both the protective layer and the second optical member include a (meth)acrylic resin. By using a (meth)acrylic resin as the protective layer and the second optical member, light leakage can be stably suppressed when a load exceeding a predetermined value is locally applied to the optical laminate.

[0225] The second optical component may, if necessary, be subjected to the surface treatment described above and / or the treatment described above to improve visibility, similar to the protective layer.

[0226] The thickness of the second optical element is typically 20 μm to 70 μm, preferably 30 μm to 50 μm. When the thickness of the second optical element is within this range, it is possible to provide the optical laminate with excellent resistance to localized loads and to sufficiently suppress warping of the optical laminate in high-humidity environments.

[0227] ≪1-8. Third Optical Component≫ As the third optical component, any suitable optical component can be used, provided that it is a component capable of imparting an optical function to the optical laminate according to the embodiment of the present invention, and does not impair the effects of the present invention. Examples of such optical components include anti-reflection laminates and sunglasses-resistant laminates.

[0228] When the optical laminate according to an embodiment of the present invention includes a third optical member, the configuration shown in Figure 2 can typically be adopted.

[0229] The thickness of the third optical element is typically 20 μm to 60 μm, preferably 30 μm to 50 μm.

[0230] One embodiment of the third optical component is an anti-reflection laminate. The anti-reflection laminate includes an anti-reflection layer and a second substrate positioned on the viewing side of the anti-reflection layer. The anti-reflection layer is supported by the second substrate. The anti-reflection layer is positioned on the viewing side of, for example, a protective layer of a polarizing film and is bonded to the protective layer via a third adhesive sheet 23. The anti-reflection layer is in contact with the third adhesive sheet 23 and may be pressure-sensitively bonded to the third adhesive sheet 23. The second substrate is located on the opposite side of the third adhesive sheet 23 from the anti-reflection layer. The second substrate is in contact with a second adhesive sheet 22 and is pressure-sensitively bonded to the second adhesive sheet 22.

[0231] <1-8-a. Anti-reflection layer> The anti-reflection layer is provided to prevent reflections of the user's face, the keyboard of the image display device, external light (e.g., fluorescent lights), etc. In one embodiment of the present invention, the anti-reflection layer is an orientation-solidified layer of a liquid crystal compound. In this specification, "orientation-solidified layer" refers to a layer in which a liquid crystal compound is oriented in a predetermined direction within the layer and that orientation state is fixed. Note that "orientation-solidified layer" is a concept that includes orientation-hardened layers obtained by hardening liquid crystal monomers. The liquid crystal compound may be a rod-shaped liquid crystal compound, a discotic (disc-shaped) liquid crystal compound, or a combination thereof.

[0232] In one embodiment of the present invention, the anti-reflection layer comprises a discotic liquid crystal compound. More specifically, the anti-reflection layer is a layer in which the discotic liquid crystal compound is immobilized in a state oriented in a predetermined direction. A discotic liquid crystal compound generally refers to a liquid crystal compound having a disc-shaped molecular structure in which a cyclic parent core such as benzene, 1,3,5-triazine, or calixarene is positioned at the center of the molecule, and linear alkyl groups, alkoxy groups, substituted benzoyloxy groups, etc., are radially substituted as side chains. Representative examples of discotic liquid crystals include benzene derivatives, triphenylene derivatives, tolkene derivatives, and phthalocyanine derivatives described in the research report of C. Destrade et al., Mol. Cryst. Liq. Cryst. Vol. 71, p. 111 (1981), and the research report of B. Kohne et al., Angew. Chem. Examples of cyclohexane derivatives described in Volume 96, page 70 (1984), and azacrown and phenylacetylene macrocycles described in the research report by J. M. Lehn et al., J. Chem. Soc. Chem. Commun., page 1794 (1985), and the research report by J. Zhang et al., J. Am. Chem. Soc., Volume 116, page 2655 (1994). Further specific examples of discotic liquid crystal compounds include, for example, the compounds described in Japanese Patent Publication No. 2006-133652, Japanese Patent Publication No. 2007-108732, Japanese Patent Publication No. 2010-244038, and Japanese Patent Publication No. 2014-214177. The descriptions in the above literature and publications are incorporated herein by reference. The anti-reflection layer containing a discotic liquid crystal compound can typically be a so-called negative A plate having a refractive index characteristic of nx = nz > ny.

[0233] In another embodiment, the anti-reflection layer includes rod-shaped liquid crystal compounds. More specifically, the anti-reflection layer is oriented such that the rod-shaped liquid crystal compounds are aligned in a predetermined direction (typically, in the slow phase axis direction) (homogenous orientation). Examples of rod-shaped liquid crystal compounds include liquid crystal compounds in which the liquid crystal phase is a nematic phase (nematic liquid crystal). Examples of such liquid crystal compounds include liquid crystal polymers and liquid crystal monomers. The mechanism by which the liquid crystal properties of the liquid crystal compound are expressed may be either lyotropic or thermotropic. Liquid crystal polymers and liquid crystal monomers may be used individually or in combination. Any suitable liquid crystal monomer can be used as the liquid crystal monomer. For example, polymerizable mesogenic compounds described in JP 2002-533742 (WO00 / 37585), EP358208 (US5211877), EP66137 (US4388453), WO93 / 22397, EP0261712, DE19504224, DE4408171, and GB2280445 can be used. Specific examples of such polymerizable mesogenic compounds include, for example, BASF's trade name LC242, Merck's trade name E7, and Wacker-Chem's trade name LC-Silicon-CC3767. As the liquid crystal monomer, nematic liquid crystal monomers are preferred. Specific examples of liquid crystal compounds are described, for example, in JP 2006-163343. The descriptions in these publications are incorporated herein by reference. The anti-reflection layer containing the rod-shaped liquid crystal compound can typically be a so-called positive A plate having a refractive index characteristic of nx > ny = nz.

[0234] The anti-reflection layer can typically function as a λ / 2 plate. When the anti-reflection layer functions as a λ / 2 plate, reflections can be effectively prevented by controlling its orientation angle (or the direction of the slow phase axis). The in-plane phase difference Re(550) of such an anti-reflection layer is 220 nm to 320 nm, more preferably 240 nm to 300 nm, and even more preferably 250 nm to 280 nm.

[0235] The angle between the slow axis of the anti-reflection layer and the absorption axis of the polarizer is preferably 35° to 55°, more preferably 40° to 50°, and even more preferably about 45°. By arranging the anti-reflection layer, which functions as a λ / 2 plate, at such an axial angle, reflections can be effectively prevented.

[0236] The thickness of the anti-reflection layer is preferably 1 μm to 5 μm, and more preferably 1 μm to 3 μm.

[0237] When an alignment film is used for the orientation of a liquid crystal compound, the anti-reflection laminate further comprises an alignment film between the anti-reflection layer and the second substrate. That is, the anti-reflection laminate may consist of an anti-reflection layer, an alignment film, and a second substrate. The alignment film generally contains a polymer material as its main component. Typical examples of polymer materials include polyvinyl alcohol, polyimide, and their derivatives. In one embodiment of the present invention, modified or unmodified polyvinyl alcohol is preferred. As the alignment film, for example, modified polyvinyl alcohol described in WO01 / 88574A1, Japanese Patent No. 3907735, can be used. The alignment film is typically subjected to an alignment treatment. Typical examples of alignment treatments include rubbing treatment and photo-alignment treatment. Since rubbing treatment is well known in the industry, a detailed explanation is omitted. As the photo-oriented orientation film (photo-alignment film), for example, those described in WO2005 / 096041, or Rolic Technologies' product name LPP-JP265CP can be used. The thickness of the orientation film is, for example, 0.01 μm to 10 μm, preferably 0.01 μm to 1 μm, and more preferably 0.01 μm to 0.5 μm.

[0238] An anti-reflection layer can be formed, for example, by the following procedure. First, an alignment film forming coating solution is applied to a second substrate and dried to form a coating film. This coating film is subjected to a rubbing treatment in a predetermined direction to form an alignment film on the second substrate. This predetermined direction may correspond to the slow axis direction of the resulting anti-reflection layer. Next, an anti-reflection layer forming coating solution (for example, a solution containing a liquid crystal compound and, if necessary, a crosslinkable monomer) is applied to the formed alignment film and heated. Heating removes the solvent from the coating solution and promotes the orientation of the liquid crystal compound. Heating may be performed in one stage or in multiple stages by changing the temperature. Then, the crosslinkable (or polymerizable) monomer is crosslinked (or polymerized) by ultraviolet irradiation to fix the orientation of the liquid crystal compound. In this way, an anti-reflection layer is formed on the second substrate (substantially on the alignment film). Methods for aligning discotic liquid crystal compounds are described, for example, in Japanese Patent Publication No. 2014-214177, and methods for aligning rod-shaped liquid crystal compounds are described, for example, in Japanese Patent Publication No. 2006-163343. The descriptions in these publications are incorporated herein by reference. The alignment film may be omitted depending on the desired alignment state and the type of liquid crystal compound.

[0239] <1-8-b. Second Substrate> The second substrate can be used to form an anti-reflection layer.

[0240] As the second substrate, any suitable resin film can be used. Examples of resin film forming materials include polyester resins such as polyethylene terephthalate (PET), cycloolefin resins such as norbornene resins, resins obtained by addition polymerization of cycloolefins (e.g., norbornene) and α-olefins (e.g., ethylene) (COC), and cellulose resins such as triacetylcellulose (TAC). In one embodiment of the present invention, the second substrate includes a cellulose resin such as TAC.

[0241] The thickness of the second substrate can be appropriately set depending on the purpose. Typically, the thickness of the second substrate is 20 μm to 200 μm, preferably 25 μm to 100 μm, and more preferably 30 μm to 50 μm.

[0242] ≪1-9. First Phase Difference Film≫ The first phase difference film may consist of a phase difference film having any suitable optical and / or mechanical properties depending on the purpose. The first phase difference film is located on the opposite side of the polarizing film from the viewing side. Typically, the first phase difference film is bonded to the opposite side of the polarizing film from the viewing side via any suitable adhesive layer. The first phase difference film may also serve as a protective layer on the opposite side of the polarizer from the viewing side.

[0243] The thickness of the first phase difference film is, for example, 5 μm to 60 μm, and may be 10 μm to 50 μm, 13 μm to 30 μm, or even 15 μm to 20 μm.

[0244] The in-plane phase difference Re(550) of the first phase difference film is preferably 80 nm to 150 nm, more preferably 90 nm to 140 nm, and even more preferably 100 nm to 130 nm.

[0245] The refractive index characteristics of the first phase difference film can be any appropriate refractive index characteristics within a range that does not impair the effects of the present invention. Preferably, the refractive index characteristics of such a first phase difference film are nx > ny > nz. With such refractive index characteristics, it is possible to impart a desired optical compensation function to the optical laminate. The Nz coefficient of the first phase difference film is preferably 1.1 to 3.0, and more preferably 1.3 to 2.7.

[0246] The first phase difference film may preferably be positioned such that its slow phase axis is substantially parallel to the absorption axis of the polarizer. In this specification, the terms “substantially parallel” and “approximately parallel” include the case where the angle between the two directions is 0° ± 7°, preferably 0° ± 5°, and more preferably 0° ± 3°. The terms “substantially orthogonal” and “approximately orthogonal” include the case where the angle between the two directions is 90° ± 7°, preferably 90° ± 5°, and more preferably 90° ± 3°. Furthermore, in this specification, when simply “orthogonal” or “parallel” is used, it may include substantially orthogonal or substantially parallel conditions.

[0247] The first phase difference film has a photoelastic coefficient of preferably 2 × 10⁻⁶. -11 I understand 2 Contains resin with a coefficient of 1 / N or less. The absolute value of this photoelastic coefficient is more preferably 2.0 × 10⁻⁶. -13 I understand 2 / N ~ 1.5 × 10 -11 I understand 2 / N, and more preferably 1.0 × 10 -12 I understand 2 / N ~ 1.2 × 10 -11 I understand 2 The value is / N. By appropriately adjusting the photoelastic coefficient of the first phase difference film, an optical laminate more suitable for suppressing display defects can be obtained even when a small object collides with or presses against the screen over a narrow contact area. If the absolute value of the photoelastic coefficient is within this range, phase difference changes are less likely to occur when shrinkage stress occurs during heating. Therefore, by forming the first phase difference film using a resin having such an absolute value of photoelastic coefficient, thermal unevenness can be effectively prevented when the optical laminate is applied to an image display device.

[0248] The first phase difference film may exhibit inverse dispersion wavelength characteristics in which the phase difference value increases with the wavelength of the measured light, positive wavelength dispersion characteristics in which the phase difference value decreases with the wavelength of the measured light, or flat wavelength dispersion characteristics in which the phase difference value hardly changes with the wavelength of the measured light. It is preferable that the first phase difference film exhibits flat wavelength dispersion characteristics. Specifically, the Re(450) / Re(550) of the first phase difference film is preferably 0.99 to 1.03, and the Re(650) / Re(550) is preferably 0.98 to 1.02. By arranging a λ / 2 plate (first phase difference film) and a λ / 4 plate (second phase difference film) having flat wavelength dispersion characteristics at a predetermined axial angle, it is possible to obtain characteristics close to ideal inverse wavelength dispersion characteristics, and as a result, extremely excellent anti-reflective properties can be realized.

[0249] The first phase difference film can be composed of any suitable resin film that can satisfy the above-described characteristics. Representative examples of such resins include cyclic olefin resins, polycarbonate resins, cellulose resins, polyester resins, polyvinyl alcohol resins, polyamide resins, polyimide resins, polyether resins, polystyrene resins, and acrylic resins. Among these, cyclic olefin resins can be preferably used. The first phase difference film can be obtained, for example, by stretching a film formed from the above-described resin. Details of the cyclic olefin resin and the method for stretching the resin film (method for forming the phase difference film) are described, for example, in Japanese Patent Application Publication No. 2015-210459 and Japanese Patent Application Publication No. 2016-105166. The descriptions in these publications are incorporated herein by reference.

[0250] ≪1-10. Second Phase Difference Film≫ The second phase difference film may consist of a phase difference film having any suitable optical and / or mechanical properties as appropriate for the purpose. The second phase difference film is located on the opposite side of the first phase difference film from the viewing side. Typically, the second phase difference film is bonded to the opposite side of the first phase difference film from the viewing side via any suitable adhesive layer.

[0251] The thickness of the second phase difference film is, for example, 10 μm or more. According to the inventors' studies, in conventional optical laminates, when a second phase difference film with a thickness of 10 μm or more is provided, light leakage due to localized loads tends to occur easily. However, in the optical laminate according to the embodiment of the present invention, the components provided in the optical laminate and the sum of the thicknesses of the first adhesive sheet and the second adhesive sheet are appropriately adjusted, thereby suppressing the occurrence of light leakage due to localized loads, even when a second phase difference film with a thickness of 10 μm or more is provided.

[0252] The thickness of the second phase difference film may be 13 μm or more, 15 μm or more, 18 μm or more, or even 20 μm or more. The upper limit of the thickness of the second phase difference film is, for example, 50 μm or less, 40 μm or less, 30 μm or less, or even 25 μm or less. The thickness of the second phase difference film is preferably 10 μm to 50 μm, and more preferably 20 μm to 40 μm. In some cases, the thickness of the second phase difference film may be less than 10 μm, or 1 μm or more and less than 10 μm.

[0253] The indentation modulus of the second phase difference film is, for example, 0.5 GPa to 4.5 GPa, and may be 1.0 GPa to 4.0 GPa, 1.5 GPa to 4.0 GPa, or even 2.0 GPa to 3.0 GPa. The indentation modulus of the second phase difference film can be measured by the same method as the measurement method for the indentation modulus described in section <1-6-b. Hard Coat Layer>, except that the indentation modulus Er at a depth of approximately 500 nm is calculated using formula (1).

[0254] The in-plane phase difference Re(550) of the second phase difference film is preferably 10 nm to 60 nm, more preferably 20 nm to 50 nm, and even more preferably 30 nm to 40 nm.

[0255] As for the refractive index characteristics of the second phase difference film, any appropriate refractive index characteristics can be adopted within a range that does not impair the effects of the present invention. Preferably, such refractive index characteristics of the second phase difference film are nz > nx > ny. With such refractive index characteristics, it is possible to impart a desired optical compensation function to the optical laminate. The Nz coefficient of the second phase difference film is preferably -10 to -0.1, and more preferably -5 to -1.

[0256] The second phase difference film may preferably be positioned such that its slow phase axis is substantially perpendicular to the absorption axis of the polarizer.

[0257] The second phase difference film can be composed of any suitable resin film that satisfies the above-described properties. Typical examples of such resins include polymers having negative intrinsic birefringence. A polymer having negative intrinsic birefringence refers to one in which, when oriented by stretching or other means, the refractive index in the orientation direction becomes relatively small. Examples of polymers having negative intrinsic birefringence include those in which chemical bonds or functional groups with high polarization anisotropy, such as aromatic or carbonyl groups, are introduced into the side chains of the polymer. Specific examples include modified polyolefin resins (e.g., modified polyethylene resins), acrylic resins, styrene resins, maleimide resins, and fumarate ester resins. The second phase difference film can be obtained, for example, by appropriately stretching a film formed from the above-described resin.

[0258] In one embodiment of the present invention, the optical laminate comprises a first phase difference film and a second phase difference film, but the optical laminate may not include the first phase difference film and / or the second phase difference film.

[0259] ≪1-11. Panel-side adhesive sheet≫ The panel-side adhesive sheet is located on the side opposite to the viewing side of the second phase difference film. The panel-side adhesive sheet may be formed by coating any suitable adhesive onto the second phase difference film. The thickness of the panel-side adhesive sheet is preferably 1 μm to 60 μm, and more preferably 5 μm to 30 μm. In one embodiment of the present invention, the optical laminate includes a panel-side adhesive sheet, but the optical laminate does not need to include a panel-side adhesive sheet.

[0260] As the panel-side adhesive sheet, any suitable adhesive sheet can be used as long as it does not impair the effects of the present invention. Typical examples of such adhesive sheets include those composed of any suitable adhesive that can be used for joining a phase difference film to other members. For example, the descriptions of the first adhesive sheet in section 1-3. First Adhesive Sheet and the third adhesive sheet in section 1-5. Third Adhesive Sheet can be referenced. In particular, the description of the third adhesive sheet obtained from a thermosetting third adhesive composition in section 1-5. Third Adhesive Sheet can be preferably referenced.

[0261] ≪≪2. Image Display Device≫≫ The optical laminate according to an embodiment of the present invention can be applied to an image display device. Therefore, one embodiment of the present invention also includes an image display device using such an optical laminate. Typical examples of image display devices include liquid crystal display devices and organic EL display devices. The image display device according to an embodiment of the present invention typically includes the optical laminate according to an embodiment of the present invention on its viewing side. The image display device includes an image display panel. The image display panel includes an image display cell. Note that the image display device may be referred to as an optical display device, the image display panel may be referred to as an optical display panel, and the image display cell may be referred to as an optical display cell.

[0262] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way to these examples. The test and evaluation methods in the examples are as follows. When "parts" is written, it means "parts by weight" unless otherwise specified, and when "%" is written, it means "percent by weight" unless otherwise specified.

[0263] <Pencil Hardness> Test samples were prepared by cutting the optical laminates prepared in the examples and comparative examples to a size of 50 mm x 150 mm and bonding them to a 1.2 mm thick glass plate via an adhesive sheet on the panel side. A pencil hardness test was performed on the surface of this test sample (specifically, the surface of the first optical component). The pencil hardness test was performed using a pencil hardness tester (Tester Industries, HA-301-S) under the following conditions: pencil hardness H, load 500 g, sliding speed 30 mm / min, sliding distance 10 mm, and number of sliding cycles 1.

[0264] When the above pencil hardness test was performed five times, if scratches or dents occurred on the surface of the test sample once or less (evaluation A), the pencil hardness was increased by one step (the hardness was changed to 2H), and the pencil hardness test was repeated using the same method as above. In this way, the pencil hardness test was repeated by increasing the hardness of the pencil by one step each time as long as evaluation A was obtained. When scratches or dents occurred on the surface of the test sample two or more times out of five (evaluation B), the pencil hardness test was terminated, and the hardness of the pencil used in the last pencil hardness test that obtained evaluation A was identified as the pencil hardness of the optical laminate.

[0265] <Maximum Allowable Load> Test samples were prepared by cutting the optical laminates prepared in the examples and comparative examples to a size of 50 mm x 50 mm and bonding them to a 1.2 mm thick glass plate via an adhesive sheet on the panel side. Next, the test samples were placed on the stage of an indenter CMS testing machine (Instron 5581, manufactured by Instron Corporation) equipped with a piercing jig. The tip of the piercing jig was rounded and pointed, and its radius of curvature R was 550 μm. Under room temperature conditions (23°C ± 3°C), the piercing jig was pierced into the optical laminate of the test sample on the stage with a load of 5 kg. After the piercing test, the polarizer of the optical laminate and the polarizer attached to the microscope were positioned to form crossed nicols, and the light leakage at this time was observed with a microscope.

[0266] If the above puncture test showed no light leakage, or only slight leakage that did not pose a practical problem (Evaluation A), the load of the puncture jig used to puncture the test sample was increased by 1 kg (changing the load to 6 kg), and the puncture test was repeated using the same method as above. In this way, the puncture test was repeated by increasing the load of the puncture jig used to puncture the test sample by 1 kg each time, as long as an Evaluation A was obtained. The puncture test was terminated when the light leakage was found to have a practical impact or to an extent that was unacceptable for practical use (Evaluation B), and the load of the puncture jig used in the last puncture test that obtained an Evaluation A (maximum allowable load) was identified.

[0267] <Smoothness> Evaluation samples were prepared by attaching the optical laminates made in the examples and comparative examples to a black board via a panel-side adhesive sheet. The smoothness of these evaluation samples was observed visually from the first optical component side and evaluated according to the following criteria. This smoothness can serve as an indicator of the smoothness of the first and second adhesive sheets. A: No noticeable unevenness was observed. B: Significantly noticeable unevenness was observed.

[0268] <Photoelastic Coefficient> The sample to be measured was cut to a size of 20 mm x 100 mm to prepare a sample. The prepared sample was measured using an ellipsometer (JASCO Corporation, M-150) with light at a wavelength of 550 nm to determine the photoelastic coefficient.

[0269] [Manufacturing Example 1] Production of Polarizing Film As a thermoplastic resin substrate, an amorphous isophthalic copolymer polyethylene terephthalate film (thickness: 100 μm) with a long length and a Tg of approximately 75°C was used, and one side of the resin substrate was subjected to corona treatment. A PVA aqueous solution (coating solution) was prepared by dissolving 100 parts by weight of a PVA-based resin, which was a mixture of polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gosephymer") in a 9:1 ratio, with 13 parts by weight of potassium iodide added, in water. The PVA aqueous solution was applied to the corona-treated surface of the resin substrate and dried at 60°C to form a PVA-based resin layer with a thickness of 13 μm, thereby producing a laminate. The obtained laminate was uniaxially stretched 2.4 times in the longitudinal direction (longitudinal direction) in an oven at 130°C (air-assisted stretching treatment). Next, the laminate was immersed for 30 seconds in an insolubilization bath at a liquid temperature of 40°C (a boric acid aqueous solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) (insolubilization treatment). Next, it was immersed for 60 seconds in a staining bath at a liquid temperature of 30°C (a iodine aqueous solution obtained by mixing iodine and potassium iodide in a weight ratio of 1:7 with 100 parts by weight of water) while adjusting the concentration so that the final transmittance (Ts) of the polarizer obtained would be the desired value (staining treatment). Next, it was immersed for 30 seconds in a crosslinking bath at a liquid temperature of 40°C (a boric acid aqueous solution obtained by mixing 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with 100 parts by weight of water) (crosslinking treatment). Subsequently, the laminate was immersed in a boric acid aqueous solution (boric acid concentration 4% by weight, potassium iodide concentration 5% by weight) at a liquid temperature of 70°C and uniaxially stretched in the longitudinal direction (longitudinal direction) between rolls with different peripheral speeds to achieve a total stretch ratio of 5.5 times (water stretching treatment). After that, the laminate was immersed in a washing bath at a liquid temperature of 20°C (an aqueous solution obtained by mixing 4 parts by weight of potassium iodide with 100 parts by weight of water) (washing treatment). After that, while drying in an oven maintained at approximately 90°C, it was brought into contact with a heated roll made of stainless steel with a surface temperature maintained at approximately 75°C (drying shrinkage treatment). In this way, a polarizer with a thickness of approximately 5 μm was formed on the resin substrate.An acrylic resin film (manufactured by Kaneka Corporation, product name "HTX") (thickness = 40 μm) having a glutarimide structure as a protective layer was bonded to the surface of the obtained polarizer (the side opposite to the resin substrate) via an ultraviolet-curing adhesive. Specifically, the curing adhesive was applied to a total thickness of approximately 2.0 μm and bonded using a roll press. Then, UV light was irradiated from the acrylic resin film side to cure the adhesive. Next, the resin substrate was peeled off to obtain a polarizing film having a 45 μm thick acrylic resin film (protective layer) / polarizer configuration.

[0270] [Manufacturing Example 2] Preparation of the First Phase Difference Film A cyclic olefin film (manufactured by Zeon Corporation, product name "Zeonor Film ZT12-50135") was used as the first phase difference film. The thickness of the first phase difference film was 18 μm. The photoelastic coefficient of the first phase difference film was 1 × 10⁻⁶ -12 I understand 2 It was / N.

[0271] [Production Example 3] Production of the second phase difference film 58.76 g of diisopropyl fumarate, 12.04 g of diethyl fumarate, and 0.39 g of t-butyl peroxypivalate, a polymerization initiator, were placed in a 75 mL glass ampoule tube. After purging with nitrogen, the tube was sealed under reduced pressure. Radical polymerization was carried out by holding this ampoule at 50°C for 24 hours. After cooling to room temperature, the resulting polymer was dissolved in tetrahydrofuran. A white powder polymer was obtained by adding the obtained polymer solution to excess methanol. The obtained polymer was washed three times with methanol and dried under reduced pressure at 80°C to obtain a fumarate ester resin. The number-average molecular weight of the obtained fumarate ester resin was 240,000. The monomer constituent units of the obtained fumarate ester resin were 80.6 mol% of diisopropyl fumarate residues and 19.4 mol% of diethyl fumarate residues. Next, 50 g of the obtained fumarate ester resin was dissolved in a mixed solvent of ethyl acetate (boiling point: 77°C) / methyl isobutyl ketone (boiling point: 116°C) = 50:50 (weight ratio), and then 2 g of plasticizer (Alfon, manufactured by Toagosei Co., Ltd.) was added to the resulting solution. The resin solution was then stirred with a disperser mixer for 60 minutes, and then allowed to stand for 48 hours to degas, obtaining a resin solution with a resin concentration of 18% by weight and a viscosity of 2.4 Pa·s. The degassed resin solution was then coated onto a substrate (50 μm thick polyethylene terephthalate (PET) film, trade name "RS11", manufactured by Toray Industries, Inc.) using an applicator to form a coating film. The substrate (sample) with the coated film was then dried at 55°C for 1 minute using a forced-air oven (ESPEC "SPH-202") (first drying step). Next, the sample after the first drying step was dried at 135°C for 1 minute using a forced-air oven (SPH-202, manufactured by ESPEC) (second drying step) to obtain a resin film with a substrate. The resin film with the substrate was uniaxially stretched at the free end under conditions of a stretching temperature of 210°C and a stretching speed of 0.1% / second relative to the film before stretching, and then the substrate was peeled off to obtain a phase difference film (second phase difference film). The stretching ratio was 1.06 times. The thickness of the second phase difference film was 21 μm. The indentation modulus of the second phase difference film was 2.3 GPa.

[0272] [Manufacturing Example 4] Preparation of the First Optical Component (1a) An anti-reflective laminate was used as the first optical component (1a). As the anti-reflective laminate, an AR film manufactured by Dexerials Corporation (AR + HC thickness: 4 μm, substrate thickness: 80 μm, total thickness: 85 μm) was used. The indentation modulus of the hard coat layer of this anti-reflective laminate was 6 GPa.

[0273] [Manufacturing Example 5] Preparation of the First Optical Component (1b) An anti-reflective laminate was used as the first optical component (1a). The anti-reflective laminate used was manufactured by Nippon Paper Industries Co., Ltd. (total thickness 95 μm). The indentation modulus of the hard coat layer (thickness 15 μm) of this anti-reflective laminate was 11.4 GPa.

[0274] [Manufacturing Example 6] Preparation of the second optical component (2) An acrylic resin film having a glutarimide structure (manufactured by Kaneka Corporation, product name "HTX") (thickness = 40 μm) was used as the second optical component (2).

[0275] [Manufacturing Example 7] Preparation of the third optical component (3) An anti-reflection laminate was used as the third optical component (3). As the anti-reflection laminate, a TAC film with a phase difference film (product name "HL214", thickness = 42 μm) manufactured by Fujifilm Corporation was used.

[0276] [Production Example 8] Preparation of Adhesive Composition (1) 72.6 parts by weight of n-butyl acrylate (BA), 3.0 parts by weight of acrylic acid (AA), 4.4 parts by weight of N-vinyl-2-pyrrolidone (NVP), and 20.0 parts by weight of benzyl acrylate (BzA), along with 0.2 parts by weight of Omnirad 127D (manufactured by IGM Resin) as a photopolymerization initiator, were placed in a four-necked flask. Next, a light source was placed 5 cm above the liquid surface in the flask, and under a nitrogen atmosphere, an illuminance of 1.2 mW / cm was applied. 2A monomer syrup (1) was obtained by partially photopolymerizing the monomer components by irradiation with ultraviolet light. The ultraviolet irradiation was carried out until the viscosity of the liquid in the flask (measurement conditions: BH viscometer No. 5 rotor, 10 rpm, measurement temperature 30°C) reached 20 Pa·s. To the obtained monomer syrup (1), 0.1 parts by weight of 1,9-nonanediol diacrylate (NDDA) as a crosslinking agent and 0.2 parts by weight of a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM-403") were mixed with 100 parts by weight of the monomer components of the monomer syrup (1). This yielded a photocurable adhesive composition (1).

[0277] [Production Example 9] Preparation of Adhesive Composition (2) 100 parts by weight of n-butyl acrylate and 5 parts by weight of acrylic acid were charged into a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser. Furthermore, 0.1 parts by weight of 2,2'-azobisisobutyronitrile was added to 100 parts by weight of this monomer mixture as a polymerization initiator along with 100 parts by weight of ethyl acetate. After introducing nitrogen gas and purging with nitrogen while gently stirring, the polymerization reaction was carried out for 8 hours while maintaining the liquid temperature in the flask at around 55°C to prepare a solution of acrylic polymer with a weight-average molecular weight (Mw) of 1.6 million. 0.45 parts by weight of an isocyanate crosslinking agent (Coronate L, trimethylolpropanetylene diisocyanate, manufactured by Tosoh Corporation) was added to 100 parts by weight of the solid content of the obtained acrylic polymer solution to obtain a thermosetting adhesive composition (2).

[0278] [Production Example 10] Preparation of adhesive composition (3) 100 parts by weight of n-butyl acrylate (BA), 5 parts by weight of acrylic acid (AA), and 0.2 parts by weight of 2-hydroxy-1-(4-(4-(2-hydroxy-2-methylpropionyl)benzyl)phenyl)-2-methylpropan-1-one (Omnirad 127D, manufactured by IGM Resins B.V.) as a photopolymerization initiator were placed in a four-necked flask and irradiated with ultraviolet light under a nitrogen atmosphere to obtain a partially photopolymerized monomer syrup (2). The ultraviolet irradiation was carried out until the viscosity of the liquid in the flask was about 20 Pa·s. The viscosity was measured using a BH viscometer No. 5 rotor at 10 rpm and a measurement temperature of 30°C. To the obtained monomer syrup (2), 0.05 parts by weight of 1,9-nonanediol diacrylate (NDDA) as a crosslinking agent and 15 parts by weight of N-acryloylmorpholine (ACMO) (KJ Chemicals Co., Ltd.) as a nitrogen atom-containing monomer were mixed to obtain a photocurable adhesive composition (3).

[0279] [Production Example 11] Preparation of adhesive composition (4) 81.9 parts by weight of n-butyl acrylate, 13.2 parts by weight of benzyl acrylate, 0.1 parts by weight of 4-hydroxybutyl acrylate, and 4.8 parts by weight of acrylic acid were charged into a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser. Furthermore, 0.1 parts by weight of 2,2'-azobisisobutyronitrile was added to 100 parts by weight of this monomer mixture as a polymerization initiator along with 100 parts by weight of ethyl acetate. After introducing nitrogen gas and purging with nitrogen while gently stirring, the polymerization reaction was carried out for 8 hours while maintaining the liquid temperature in the flask at around 55°C to prepare a solution of an acrylic polymer with a weight-average molecular weight (Mw) of 1.6 million. A thermosetting adhesive composition (4) was obtained by blending 0.2 parts by weight of an oligomer-type mercapto group-containing silane coupling agent (X-41-1810, manufactured by Shin-Etsu Chemical Co., Ltd.) and 0.45 parts by weight of an isocyanate-based crosslinking agent (Coronate L, trimethylolpropane tolylene diisocyanate, manufactured by Tosoh Corporation) with 100 parts by weight of the solid content of the obtained acrylic polymer solution.

[0280] [Production Example 12] Preparation of Additive Solution (1) Additive solution (1) was prepared by mixing 100 parts by weight of 1,9-nonanediol diacrylate (NDDA) as a crosslinking agent, 3.0 parts by weight of bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (trade name "Omnirad 819", manufactured by IGM Resins B.V.) as a photopolymerization initiator, and 103 parts by weight of ethyl acetate as a solvent.

[0281] [Comparative Example 1] A laminate was prepared by laminating the polarizing film obtained in Production Example 1 (acrylic resin film (protective layer) / polarizer), the first phase difference film obtained in Production Example 2, and the second phase difference film obtained in Production Example 3 in this order. The first phase difference film was bonded to the polarizer side of the polarizing film. Specifically, an ultraviolet-curing adhesive was used for bonding, and the first phase difference film was bonded so that its slow phase axis was at an angle of 0° with respect to the absorption axis of the polarizer, and the second phase difference film was bonded so that its slow phase axis was at an angle of 90° with respect to the absorption axis of the polarizer. As a result, a laminate P1 with the laminated structure of "polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm)" was obtained. Separately, the adhesive composition (1) obtained in Production Example 8 was applied to the release surface of a release liner A (PET film with release treatment, manufactured by Mitsubishi Chemical, MRF38) using an applicator to form a coating layer. Next, a release liner B (a PET film with a release treatment (PET film thickness of 38 μm), manufactured by Nitto Denko Corporation) was placed on the formed coating layer to obtain laminate A1. The release liner B was positioned so that the release layer was in contact with the coating layer. Next, an illuminance of 9 mW / cm was applied from the side of the release liner A in laminate A1. 2 The conditions (cumulative light intensity 800 mJ / cm²) 2Light was irradiated using an LED. The peak wavelength of the irradiated light from the LED was 340 nm. As a result, the coated layer was photocured, and a laminate B1 consisting of a release liner A / second adhesive sheet (1) (thickness 12 μm) / release liner B was formed. The illuminance of the light was measured using an illuminance meter (Topcon Techno House, UD-T3040T2) at a position near the incident surface of ultraviolet light on the release liner A. Next, the release liner B was peeled off the laminate B1, and the second optical member (2) obtained in manufacturing example 6 (an acrylic resin film having a glutarimide structure as a reinforcing layer) was placed on the exposed surface of the second adhesive sheet (1). As a result, a laminate Q1 with a laminated structure of "release liner A / second adhesive sheet (1) (thickness 12 μm) / second optical member (2) (thickness 40 μm)" was obtained. The release liner A was peeled off from the laminate Q1, and the exposed second adhesive sheet (1) was bonded to the protective layer of the laminate P1. This resulted in the creation of a laminate R1 with the following lamination configuration: "second optical component (2) (thickness 40 μm) / second adhesive sheet (1) (thickness 12 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm)". Separately, the adhesive composition (1) obtained in Manufacturing Example 8 was applied to the release surface of the release liner A (a PET film treated with a release agent, manufactured by Mitsubishi Chemical, MRF38) using an applicator to form a coating layer. Next, the release liner B (a PET film treated with a release agent (PET film thickness 38 μm), manufactured by Nitto Denko Corporation) was placed on the formed coating layer to obtain the laminate C1. The release liner B was positioned so that its release layer was in contact with the coating layer. Next, from the side of the peeling liner A in the laminate C1, the illuminance was 9 mW / cm². 2 The conditions (cumulative light intensity 800 mJ / cm²) 2Light was irradiated using an LED. The peak wavelength of the irradiated light from the LED was 340 nm. As a result, the coating layer was photocured, and a laminate D1 consisting of peel liner A / first adhesive sheet (1) (thickness 12 μm) / peel liner B was formed. The illuminance of the light was measured using an illuminance meter (Topcon Techno House, UD-T3040T2) at a position near the incident surface of ultraviolet light on peel liner A. Next, peel liner B was peeled off from laminate D1, and the first optical member (1a) obtained in manufacturing example 4 was placed on the exposed surface of the first adhesive sheet (1). As a result, a laminate S1 with a laminated structure of "peel liner A / first adhesive sheet (1) (thickness 12 μm) / first optical member (1a) (thickness 85 μm)" was obtained. The release liner A was peeled off from the laminate S1, and the exposed first adhesive sheet (1) was bonded to the second optical member (2) of the laminate R1. As a result, a laminate T1 was obtained with the following lamination configuration: "first optical member (1a) (thickness 85 μm) / first adhesive sheet (1) (thickness 12 μm) / second optical member (2) (thickness 40 μm) / second adhesive sheet (1) (thickness 12 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm)". Separately, the adhesive composition (4) obtained in manufacturing example 11 was applied to the release surface of the release liner A (PET film that has undergone release treatment, manufactured by Mitsubishi Chemical, MRF38) to form a coating film. Next, the coating layer was dried at 155°C for 1 minute. As a result, the coating layer was heat-cured, forming a laminate E1 composed of a release liner A and a panel-side adhesive sheet (thickness 15 μm). Next, the panel-side adhesive sheet of laminate E1 was transferred to the side of the second phase difference film of laminate T1 opposite to the first phase difference film. Through the above steps, an optical laminate (1) with the laminated structure of "first optical member (1a) (thickness 85 μm) / first adhesive sheet (1) (thickness 12 μm) / second optical member (2) (thickness 40 μm) / second adhesive sheet (1) (thickness 12 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm) / panel-side adhesive sheet (thickness 15 μm)" was obtained.

[0282] [Reference Example 1] In the same manner as in Comparative Example 1, a laminate P1 was obtained with a laminated structure of "polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm)". Separately, the adhesive composition (2) obtained in Manufacturing Example 9 was applied to the release surface of a release liner A (PET film that has undergone release treatment, manufactured by Mitsubishi Chemical, MRF38) to form a coating film. Next, the coating layer was dried at 155°C for 1 minute. As a result, the coating layer was heat-cured, and a laminate B2 composed of release liner A / second adhesive sheet (2) (thickness 25 μm) was formed. Next, the second adhesive sheet (2) of laminate B2 was bonded to the protective layer of laminate P1. Furthermore, the release liner A was peeled off, and the second optical member (2) obtained in Manufacturing Example 6 (acrylic resin film having a glutarimide structure as a reinforcing layer) was placed on the exposed surface of the second adhesive sheet (2). As a result, a laminate R2 was obtained with a laminated structure of "second optical member (2) (thickness 40 μm) / second adhesive sheet (2) (thickness 25 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm)". Separately, the adhesive composition (2) obtained in manufacturing example 9 was applied to the release surface of a release liner A (PET film that has undergone release treatment, manufactured by Mitsubishi Chemical, MRF38) to form a coating film. Next, the coating layer was dried at 155°C for 1 minute. As a result, the coating layer was heat-cured, and a laminate D2 composed of release liner A / first adhesive sheet (2) (thickness 25 μm) was formed. Next, the first adhesive sheet (2) of laminate D2 was bonded to the second optical member (2) of laminate R2. Furthermore, the release liner A was peeled off, and the first optical member (1a) obtained in Manufacturing Example 4 was placed on the exposed surface of the first adhesive sheet (2). As a result, a laminate T2 was obtained with the laminated structure of "first optical member (1a) (thickness 85 μm) / first adhesive sheet (2) (thickness 25 μm) / second optical member (2) (thickness 40 μm) / second adhesive sheet (2) (thickness 25 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm)". Next, the panel-side adhesive sheet of the laminate E1 obtained in Comparative Example 1 was transferred to the side of the second phase difference film of the laminate T2 opposite to the first phase difference film.Based on the above, an optical laminate (2) was obtained with the laminated structure of "first optical member (1a) (thickness 85 μm) / first adhesive sheet (2) (thickness 25 μm) / second optical member (2) (thickness 40 μm) / second adhesive sheet (2) (thickness 25 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm) / panel-side adhesive sheet (thickness 15 μm)".

[0283] [Example 1] The procedure was the same as in Comparative Example 1, except that the thickness of the second adhesive sheet was changed to 20 μm. As a result, an optical laminate (3) with the laminated structure of "first optical member (1a) (thickness 85 μm) / first adhesive sheet (1) (thickness 12 μm) / second optical member (2) (thickness 40 μm) / second adhesive sheet (3) (thickness 20 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm) / panel-side adhesive sheet (thickness 15 μm)" was obtained.

[0284] [Example 2] The procedure was the same as in Comparative Example 1, except that the thickness of the second adhesive sheet was changed to 40 μm. As a result, an optical laminate (4) with the following laminated configuration was obtained: "first optical member (1a) (thickness 85 μm) / first adhesive sheet (1) (thickness 12 μm) / second optical member (2) (thickness 40 μm) / second adhesive sheet (4) (thickness 40 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm) / panel-side adhesive sheet (thickness 15 μm)".

[0285] [Example 3] The procedure was the same as in Comparative Example 1, except that the thickness of the first adhesive sheet was changed to 20 μm and the thickness of the second adhesive sheet was changed to 20 μm. As a result, an optical laminate (5) with the laminated structure of "first optical member (1a) (thickness 85 μm) / first adhesive sheet (3) (thickness 20 μm) / second optical member (2) (thickness 40 μm) / second adhesive sheet (3) (thickness 20 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm) / panel-side adhesive sheet (thickness 15 μm)" was obtained.

[0286] [Example 4] The procedure was the same as in Comparative Example 1, except that the thickness of the first adhesive sheet was changed to 25 μm and the thickness of the second adhesive sheet was changed to 25 μm. As a result, an optical laminate (6) with the laminated configuration of "first optical member (1a) (thickness 85 μm) / first adhesive sheet (4) (thickness 25 μm) / second optical member (2) (thickness 40 μm) / second adhesive sheet (5) (thickness 25 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm) / panel-side adhesive sheet (thickness 15 μm)" was obtained.

[0287] [Example 5] The procedure was the same as in Comparative Example 1, except that the thickness of the first adhesive sheet was changed to 30 μm and the thickness of the second adhesive sheet was changed to 30 μm. As a result, an optical laminate (7) with the laminated structure of "first optical member (1a) (thickness 85 μm) / first adhesive sheet (5) (thickness 30 μm) / second optical member (2) (thickness 40 μm) / second adhesive sheet (6) (thickness 30 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm) / panel side adhesive sheet (thickness 15 μm)" was obtained.

[0288] [Example 6] The procedure was the same as in Comparative Example 1, except that the thickness of the first adhesive sheet was changed to 35 μm and the thickness of the second adhesive sheet was changed to 15 μm. As a result, an optical laminate (8) with the laminated structure of "first optical member (1a) (thickness 85 μm) / first adhesive sheet (6) (thickness 35 μm) / second optical member (2) (thickness 40 μm) / second adhesive sheet (7) (thickness 15 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm) / panel-side adhesive sheet (thickness 15 μm)" was obtained.

[0289] [Example 7] In the same manner as in Comparative Example 1, a laminate R1 was obtained with a laminated structure of "second optical member (2) (thickness 40 μm) / second adhesive sheet (1) (thickness 12 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm)". Separately, the adhesive composition (3) obtained in Manufacturing Example 10 was applied to the release surface of a first release liner (product name "Diafoil MRF", thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) having a release surface on one side using an applicator to form a coating layer. Next, the release surface of a second release liner (product name "Diafoil MRE", thickness 75 μm, manufactured by Mitsubishi Chemical Corporation) having a release surface on one side was bonded onto the coating layer formed on the first release liner. Next, an illuminance of 9 mW / cm was applied to the coating layer between the release liners from the first release liner side. 2 The conditions (cumulative light intensity 2700 mJ / cm²) 2Light was irradiated using an LED. This caused the coating layer to photocur, forming a laminate composed of a first release liner, a first adhesive sheet precursor (32 μm thick), and a second release liner. An LED was used as the light source. With the LED, the peak wavelength of the irradiated light was 340 nm. Next, the second release liner was peeled off the obtained laminate, and the additive solution (1) obtained in Production Example 12 was applied to the exposed surface of the first adhesive sheet precursor. The amount of additive solution (1) applied was determined so that the total amount of additives in the additive solution (1) was 20 parts by weight for every 80 parts by weight of the adhesive composition (3) used to form the first adhesive sheet precursor, resulting in a coating thickness of approximately 17 μm. A bar coater RDS No. 30 manufactured by R.D.SPECIALTIES was used for application. Next, it was dried in a 110°C oven for 3 minutes. Through coating and drying processes, the additive components were permeated into the first adhesive sheet precursor, and the solvent was vaporized. The first adhesive sheet precursor was transformed into a photocurable first adhesive sheet precursor due to the permeation of the additive components. Next, the release surface of a third peel-off liner (product name "Diafoil MRE", thickness 75 μm, manufactured by Mitsubishi Chemical Corporation), which has a release surface on one side, was bonded onto the photocurable first adhesive sheet precursor on the first peel-off liner. Next, a black light (manufactured by Toshiba, wavelength 320 nm to 400 nm, illuminance 2.5 mW / cm) was applied to the photocurable first adhesive sheet precursor between the peel-off liners from the first peel-off liner side. 2 , cumulative light intensity 2400 mJ / cm 2Light was irradiated onto the material. As a result, the photocurable first adhesive sheet precursor was photocured, and a laminate D3 consisting of a first release liner, a first adhesive sheet (7) (thickness 40 μm), and a third release liner was formed. Next, the third release liner was peeled off from the laminate D3, and the first optical member (1a) obtained in Manufacturing Example 4 was placed on the exposed surface of the first adhesive sheet (7). This obtained a laminate S2 with a laminated structure of "first release liner / first adhesive sheet (7) (thickness 40 μm) / first optical member (1a) (thickness 85 μm)". The first release liner was peeled off from the laminate S2, and the exposed first adhesive sheet (7) was bonded to the second optical member (2) of the laminate R1. As a result, a laminate T3 was obtained with the following lamination configuration: "First optical member (1a) (thickness 85 μm) / First adhesive sheet (7) (thickness 40 μm) / Second optical member (2) (thickness 40 μm) / Second adhesive sheet (1) (thickness 12 μm) / Polarizing film (thickness 45 μm) / First phase difference film (thickness 18 μm) / Second phase difference film (thickness 21 μm)". Next, the panel-side adhesive sheet of the laminate E1 obtained in Comparative Example 1 was transferred to the side of the second phase difference film of the laminate T3 opposite to the first phase difference film. Based on the above, an optical laminate (9) was obtained with the laminated structure of "first optical member (1a) (thickness 85 μm) / first adhesive sheet (7) (thickness 40 μm) / second optical member (2) (thickness 40 μm) / second adhesive sheet (1) (thickness 12 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm) / panel-side adhesive sheet (thickness 15 μm)".

[0290] [Example 8] The procedure was the same as in Example 4, except that the first optical member (1b) obtained in Manufacturing Example 5 was used instead of the first optical member (1a). As a result, an optical laminate (10) with the laminated structure of "first optical member (1b) (thickness 95 μm) / first adhesive sheet (4) (thickness 25 μm) / second optical member (2) (thickness 40 μm) / second adhesive sheet (5) (thickness 25 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm) / panel-side adhesive sheet (thickness 15 μm)" was obtained.

[0291] [Example 9] A laminate P1 with a laminated structure of "polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm)" was obtained in the same manner as in Comparative Example 1. Separately, the adhesive composition (2) obtained in Manufacturing Example 9 was applied to the release surface of a release liner A (PET film that has undergone a release treatment, manufactured by Mitsubishi Chemical, MRF38) to form a coating film. Next, the coating layer was dried at 155°C for 1 minute. As a result, the coating layer was heat-cured, and a laminate F1 composed of release liner A / third adhesive sheet (1) (thickness 12 μm) was formed. Next, the third adhesive sheet (1) of laminate F1 was bonded to the protective layer of laminate P1. Furthermore, the release liner A was peeled off, and the third optical member (3) (anti-reflection laminate) obtained in Manufacturing Example 7 was placed on the exposed surface of the third adhesive sheet (1). Specifically, the anti-reflection layer (orientation solidification layer of liquid crystal compound) of the third optical member (3) was brought into contact with the third adhesive sheet (1), and the third optical member (3) was bonded to the polarizing film via the third adhesive sheet (1). At this time, the slow axis of the anti-reflection layer was adjusted to form a 45° angle with respect to the absorption axis of the polarizer. Next, a laminate Q1 with a laminated structure of "peel liner A / second adhesive sheet (1) (thickness 12 μm) / second optical member (2) (thickness 40 μm)" was obtained in the same manner as in Comparative Example 1. The peel liner A was peeled off from the laminate Q1, and the exposed second adhesive sheet (1) was bonded to the second substrate of the third optical member (3). As described above, a laminate was obtained with the following lamination configuration: "second optical member (2) (thickness 40 μm) / second adhesive sheet (1) (thickness 12 μm) / third optical member (3) (thickness 42 μm) / third adhesive sheet (1) (thickness 12 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm)". Next, a laminate S1 was obtained with the following lamination configuration: "release liner A / first adhesive sheet (1) (thickness 12 μm) / first optical member (1a) (thickness 85 μm)" in the same manner as in Comparative Example 1. The release liner A was peeled off from the laminate S1, and the exposed first adhesive sheet (1) was attached to the second optical member (2).As a result, a laminate T4 was obtained with the following lamination configuration: "First optical member (1a) (thickness 85 μm) / First adhesive sheet (1) (thickness 12 μm) / Second optical member (2) (thickness 40 μm) / Second adhesive sheet (1) (thickness 12 μm) / Third optical member (3) (thickness 42 μm) / Third adhesive sheet (1) (thickness 12 μm) / Polarizing film (thickness 45 μm) / First phase difference film (thickness 18 μm) / Second phase difference film (thickness 21 μm)". Next, the panel-side adhesive sheet of the laminate E1 obtained in Comparative Example 1 was transferred to the side of the second phase difference film of the laminate T4 opposite to the first phase difference film. Based on the above, an optical laminate (11) with the laminated structure of "first optical member (1a) (thickness 85 μm) / first adhesive sheet (1) (thickness 12 μm) / second optical member (2) (thickness 40 μm) / second adhesive sheet (1) (thickness 12 μm) / third optical member (3) (thickness 42 μm) / third adhesive sheet (1) (thickness 12 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm) / panel-side adhesive sheet (thickness 15 μm)" was obtained.

[0292] [Example 10] The procedure was the same as in Example 9, except that the thickness of the first adhesive sheet was changed to 20 μm. As a result, an optical laminate (12) with the laminated configuration of "first optical member (1a) (thickness 85 μm) / first adhesive sheet (3) (thickness 20 μm) / second optical member (2) (thickness 40 μm) / second adhesive sheet (1) (thickness 12 μm) / third optical member (3) (thickness 42 μm) / third adhesive sheet (1) (thickness 12 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm) / panel-side adhesive sheet (thickness 15 μm)" was obtained.

[0293] [Example 11] The procedure was the same as in Example 9, except that the thickness of the first adhesive sheet was changed to 20 μm and the thickness of the second adhesive sheet was changed to 20 μm. As a result, an optical laminate (13) with the laminated configuration of "first optical member (1a) (thickness 85 μm) / first adhesive sheet (3) (thickness 20 μm) / second optical member (2) (thickness 40 μm) / second adhesive sheet (3) (thickness 20 μm) / third optical member (3) (thickness 42 μm) / third adhesive sheet (1) (thickness 12 μm) / polarizing film (thickness 45 μm) / first phase difference film (thickness 18 μm) / second phase difference film (thickness 21 μm) / panel side adhesive sheet (thickness 15 μm)" was obtained.

[0294]

[0295]

[0296] As can be seen from Tables 1 and 2, the optical laminates of Examples 1 to 8 and 10 to 11, in which the sum of the thicknesses of the first adhesive sheet and the second adhesive sheet was 30 μm or more, had a maximum allowable load value greater than that of Comparative Example 1. In addition, the optical laminate of Example 9, which was further equipped with a third optical member and in which the sum of the thicknesses of the first adhesive sheet and the second adhesive sheet was 20 μm or more, also had a maximum allowable load value greater than that of Comparative Example 1. From these results, it can be said that the optical laminates of the examples have a configuration that suppresses the occurrence of light leakage due to localized loads.

[0297] As can be seen from the results of Reference Example 1, even when using a thermosetting adhesive composition, the maximum allowable load increased by adjusting the sum of the thicknesses of the first adhesive sheet and the second adhesive sheet to 30 μm or more. However, in this case, a noticeably uneven surface was observed in the optical laminate, indicating a problem with smoothness.

[0298] The optical laminate according to the embodiment of the present invention can be suitably used in image display devices (typically liquid crystal display devices and organic EL display devices).

Claims

The device comprises a first optical component, a first adhesive sheet, a second optical component, a second adhesive sheet, and a polarizing film in this order. The first adhesive sheet is formed from a photocurable first adhesive composition, The aforementioned second adhesive sheet is formed from a photocurable second adhesive composition, An optical laminate in which the sum of the thickness of the first adhesive sheet and the thickness of the second adhesive sheet is 30 μm or more. 　 The device comprises a first optical component, a first adhesive sheet, a second optical component, a second adhesive sheet, a third optical component, a polarizing film, a first phase difference film, and a second phase difference film in this order. The thickness of the second phase difference film is 10 μm or more. The first adhesive sheet is formed from a photocurable first adhesive composition, The aforementioned second adhesive sheet is formed from a photocurable second adhesive composition, An optical laminate in which the sum of the thickness of the first adhesive sheet and the thickness of the second adhesive sheet is 20 μm or more. 　 The optical laminate according to claim 1 or 2, wherein at least one selected from the group consisting of the thickness of the first adhesive sheet and the thickness of the second adhesive sheet is 20 μm or more. 　 The optical laminate according to claim 1 or 2, wherein the total value is less than 60 μm. 　 The polarizing film further comprises a first phase difference film and a second phase difference film located on the opposite side of the first optical member from the polarizing film, The optical laminate according to claim 1, wherein the polarizing film, the first phase difference film, and the second phase difference film are arranged in this order. 　 The optical laminate according to claim 5, wherein the thickness of the second phase difference film is 10 μm or more. 　 The first adhesive composition comprises monomer component M1, The optical laminate according to claim 1 or 2, wherein the monomer component M1 contains a nitrogen atom-containing monomer. 　 The second adhesive composition comprises monomer component M2, The optical laminate according to claim 1 or 2, wherein the monomer component M2 contains a nitrogen atom-containing monomer. 　 The optical laminate according to claim 1 or 2, wherein the first optical member has a hard coat layer. 　 The optical laminate according to claim 9, wherein the indentation modulus of the hard coat layer is 5 GPa or more. 　 An image display device comprising the optical laminate according to claim 1 or 2.

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