Optical laminate and image display device

Abstract

To provide an optical laminate capable of effectively reducing reflection unevenness of external light reflection. And an image display device including such an optical laminate.SOLUTION: An optical laminate according to an embodiment of the present invention is an optical laminate in which a first light-transmitting optical film and a second light-transmitting optical film are bonded to each other through an adhesive layer, wherein the thickness of the adhesive layer is 50nm or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical laminate and an image display device. [Background technology]

[0002] Image display devices such as liquid crystal display devices and organic EL display devices usually include an optical laminate including a plurality of light-transmitting optical films. In such an optical laminate, a pressure-sensitive adhesive is used to bond the plurality of light-transmitting optical films together.

[0003] In image display devices, the occurrence of reflection unevenness that is visually recognized due to reflection of external light in a non-illuminated (OFF) state has become a problem.

[0004] Recently, a molecular adhesion technique that bonds materials by chemical bonding has been reported as a pressure-sensitive adhesive used in optical laminates (Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2022 / 172755 Brochure Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide an optical laminate that can effectively reduce reflection unevenness in external light reflection, and to provide an image display device that includes such an optical laminate. [Means for solving the problem]

[0007] An image display device typically includes an optical laminate in which many optical films are laminated, in addition to a display element that forms an image. This optical laminate serves to improve the display performance of the image display device and to add an anti-reflection function, and is an essential component of the image display device. From the viewpoint of power consumption, the mainstream image display device typically displays black in a non-illuminated state, which is called normally black.

[0008] When external light (visible light) enters an image display device, it is reflected at the interfaces of the optical elements that make up the optical laminate. Such reflection of light at the interfaces of optical elements is particularly noticeable in organic EL displays when the display is not lit. Furthermore, when the thickness between optical elements is in the range of several hundred nanometers to several micrometers, the reflected light appears colored due to the interference of reflected light at adjacent interfaces.

[0009] Recently, the occurrence of reflection unevenness, which is visible due to the reflection of external light when the image display device is turned off, has become a problem. This reflection unevenness is observed as a change in the reflection spectrum, and is typically seen as a relatively strong pink reflection in a weak green reflected light. It is thought that the coloring that occurs when reflected light interferes at two thin interfaces between optical elements is the cause of reflection unevenness.

[0010] Therefore, the present inventors investigated the cause of such reflection unevenness. First, they considered that the reflection unevenness is caused by a change in wavelength of constructive interference caused by a change in thickness of two thin interfaces between optical elements, resulting in a strong observed color change. They then considered that the optical elements, particularly the interface between the adhesive layer bonding the translucent optical film and the adjacent translucent optical film, have a significant influence on this reflection unevenness. They considered that the occurrence of unevenness or waviness in the thickness of the adhesive layer causes a change in the interference wavelength at which the reflected light generated at the two interfaces sandwiching the adhesive layer constructively or destructively interferes, and that this is observed as color unevenness.

[0011] Furthermore, it is considered that when there is a large difference in refractive index between the pressure-sensitive adhesive layer and the light-transmitting optical film bonded adjacent to it, the presence of an interface between the pressure-sensitive adhesive layer and the optical element bonded adjacent to it, particularly the light-transmitting optical film, causes noticeable reflection of external light.

[0012] Therefore, the present inventors considered that when thickness unevenness or waviness occurs in the adhesive layer, there are parts where the optical path length of the reflected light (the product of the thickness and the refractive index) differs within the plane, causing interference unevenness of the reflected light at the interface, and as a result, the reflection unevenness becomes noticeable. They investigated whether the problem could be solved by technical means that take the optical path length into consideration, and considered that if the optical path length is made sufficiently small for the target visible light wavelength, the adhesive layer will lose its sensitivity to light and interference of the reflected light will not occur.

[0013] Based on the above-mentioned concept, the present inventors have conducted extensive studies and found that, taking a thickness of 1 / 10 of the wavelength of external light as a standard for the pressure-sensitive adhesive layer, by adopting an adhesive layer thinner than 1 / 10 of the wavelength of external light, even if there is a large difference in refractive index between the adhesive layer and the adjacent light-transmitting optical film bonded thereto, the optical path length (product of thickness and refractive index) of the adhesive layer can be made small because the thickness of the adhesive layer is thin, thereby eliminating the sensitivity of the adhesive layer to light and preventing interference of reflected light. This is thought to be because, when the thickness of the adhesive layer is set as described above, the adhesive layer can be treated as if it does not exist to light, and even if there is thickness unevenness in the adhesive layer, the adhesive layer itself is in a state that is imperceptible to light in the first place, so there is no interference of reflected light due to interfacial reflection at the two interfaces between the adhesive layer and its adjacent layer, and therefore the reflection unevenness itself is not observed. In particular, because the wavelengths of ambient light with high luminosity are in the 500 to 610 nm range, centered around 555 nm, where luminosity is at its highest, the researchers found that if the adhesive layer thickness is 1 / 10 of 500 nm, i.e., 50 nm or less, reflection unevenness at wavelengths longer than 500 nm is more effectively suppressed, and the thinner the thickness, the greater the effect of suppressing reflection unevenness. If the adhesive layer is made even thinner, for example, to 30 nm, even if the adhesive layer has a high refractive index of about 1.60, the optical path length will be 48 nm, which is about 1 / 8 to 1 / 16 of the visible light wavelengths (380 to 780 nm). For light with wavelengths of 500 nm or longer, which is particularly important as a cause of reflection unevenness, the optical path length will be less than 1 / 10, resulting in extremely high reflection unevenness suppression.

[0014] In addition, when the adhesive layer is sufficiently thick, for example, more than 20 μm, there are many wavelengths in the visible light range that constructively interfere with each other and destructively interfere with each other due to the interference of reflected light at the interface, and therefore the order of interference is sufficiently large, making it difficult to observe interference colors and the reflected light becomes nearly achromatic. Therefore, even if the thickness of the adhesive layer varies, reflection unevenness as color unevenness is not observed in practice.

[0015] [1] The optical laminate according to an embodiment of the present invention is An optical laminate in which a first light-transmitting optical film and a second light-transmitting optical film are bonded together with an adhesive layer, The adhesive layer has a thickness of 50 nm or less. [2] In the optical laminate described in [1] above, the adhesive layer may have a thickness of less than 30 nm. [3] In the optical laminate according to the above [1] or [2], the difference in in-plane refractive index between the first light-transmitting optical film and the adhesive layer may be 0.05 or more. [4] In the optical laminate according to any one of the above items [1] to [3], the first light-transmitting optical film may have an in-plane refractive index of 1.50 or more. [5] In the optical laminate according to any one of the above items [1] to [4], the difference in in-plane refractive index between the second light-transmitting optical film and the adhesive layer may be 0.05 or more. [6] In the optical laminate according to any one of the above items [1] to [5], the second light-transmitting optical film may have an in-plane refractive index of 1.50 or more. [7] In the optical laminate according to any one of the above items [1] to [6], at least one of the first light-transmitting optical film and the second light-transmitting optical film may be a retardation film. [8] In the optical laminate according to any one of [1] to [7] above, the adhesive layer may be formed from an aqueous adhesive solution containing at least one amino compound. [9] In the optical laminate according to any one of [1] to [8] above, the adhesive layer may be formed from an aqueous adhesive solution containing at least one amino compound and an epoxy compound.

[10] In the optical laminate according to any one of the above items [1] to [9], the adhesive layer may contain an organosilicon compound.

[11] An image display device according to an embodiment of the present invention includes the optical laminate according to any one of the above items [1] to

[10] . [Effects of the Invention]

[0016] According to an embodiment of the present invention, an optical laminate capable of effectively reducing reflection unevenness of external light reflection can be provided. Also, according to an embodiment of the present invention, an image display device including such an optical laminate can be provided. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic cross-sectional view of one embodiment of an optical laminate of the present invention. [Figure 2] 1 is a schematic cross-sectional view of one embodiment of an optical member including an optical laminate according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] When the expression "weight" appears in this specification, it may be read as "mass," which is a commonly used SI unit indicating weight.

[0019] The definitions of terms and symbols used in this specification are as follows. (1) Refractive index (nx, ny, nz) "nx" is the refractive index in the direction in which the in-plane refractive index is maximum (i.e., the slow axis direction), "ny" is the refractive index in the direction perpendicular to the slow axis in the plane (i.e., the fast axis direction), and "nz" is the refractive index in the thickness direction. Note that when the expression "in-plane refractive index" is used in this specification, it refers to "nx." (2) In-plane phase difference (Re) "Re(λ)" is the in-plane retardation of a film measured with light of wavelength λ nm at 23°C. For example, "Re(550)" is the in-plane retardation of a film measured with light of wavelength 550 nm at 23°C. Re(λ) is calculated by the formula: Re=(nx-ny)×d, where d(nm) is the thickness of the film. (3) Thickness direction retardation (Rth) "Rth(λ)" is the thickness direction retardation of a film measured with light of wavelength λ nm at 23°C. For example, "Rth(550)" is the thickness direction retardation of a film measured with light of wavelength 550 nm at 23°C. Rth(λ) is calculated by the formula: Rth=(nx-nz)×d, where d (nm) is the thickness of the film.

[0020] ≪1. Optical laminate≫ An optical laminate according to an embodiment of the present invention is an optical laminate in which a first light-transmitting optical film and a second light-transmitting optical film are bonded together with an adhesive layer, i.e., the optical laminate according to an embodiment of the present invention has, in this order, a first light-transmitting optical film, an adhesive layer, and a second light-transmitting optical film.

[0021] Fig. 1 is a schematic cross-sectional view of one embodiment of the optical laminate of the present invention. In Fig. 1, the optical laminate 100 includes a first light-transmitting optical film 10 and a second light-transmitting optical film 20 bonded together with an adhesive layer 30.

[0022] The thickness of the optical laminate according to the embodiment of the present invention may be any appropriate thickness as long as the effects of the present invention are not impaired. Such a thickness is, for example, 1 μm to 400 μm, or may be 2 μm to 200 μm. From the viewpoint of thinning, the thickness of the light-transmitting optical film is, for example, 1 μm to 100 μm, or may be 2 μm to 80 μm, 2 μm to 60 μm, 2 μm to 40 μm, 2 μm to 20 μm, or 2 μm to 10 μm.

[0023] The thickness of the adhesive layer is preferably thinner than 1 / 10 of the wavelength of external light. In this way, if the thickness of the adhesive layer is thinner than 1 / 10 of the wavelength of external light, even if there is a large difference in refractive index between the adhesive layer and the adjacently bonded light-transmitting optical film, the adhesive layer's thin thickness makes it possible to reduce the optical path length of the adhesive layer (the product of the thickness and the refractive index), thereby eliminating the optical sensitivity of the adhesive layer and preventing interference of reflected light, and the thinner this thickness is, the greater the effect of suppressing reflection unevenness can be.

[0024] The thickness of the adhesive layer is preferably 1 / 10 of the wavelength of 500 nm, which has a particularly high luminosity, i.e., 50 nm or less. Furthermore, even with light having a wavelength shorter than 500 nm, interference is sufficiently suppressed and coloring is lighter compared to an adhesive layer thicker than 1 μm, making it fully practical. Furthermore, since visible light is 380 nm to 780 nm, the thickness of the adhesive layer is preferably 38 nm or less, and even more preferably 30 nm or less. Furthermore, considering that the optical path length is preferably 1 / 10 of the target visible light wavelength and that the refractive index of the adhesive layer is typically around 1.40 to 1.60, the thickness of the adhesive layer is preferably 30 nm or less. Furthermore, when manufacturing industrially, considering the margin of the adhesive layer, it is preferable that the maximum thickness of the adhesive layer does not exceed 30 nm, and the average thickness is preferably 25 nm or less.

[0025] For the above reasons, in the optical laminate according to the embodiment of the present invention, the thickness of the adhesive layer is very small, preferably 50 nm or less, and may be 40 nm or less, 38 nm or less, 35 nm or less, 30 nm or less, less than 30 nm, 25 nm or less, 20 nm or less, 15 nm or less, or 10 nm or less. The lower limit of the thickness of the adhesive layer is, for example, 1 nm or more, or 2 nm or more. In the optical laminate according to the embodiment of the present invention, by setting the thickness of the adhesive layer as described above, an unexpectedly excellent effect can be achieved, in particular, that uneven reflection of external light can be effectively reduced even when there is a large difference in refractive index between the adhesive layer and the translucent optical film bonded adjacent to it.

[0026] In an optical laminate according to an embodiment of the present invention, reflection unevenness in external light reflection can be effectively reduced even if there is a large difference in refractive index between the adhesive layer and the translucent optical film bonded adjacent to it. Therefore, in an optical laminate according to an embodiment of the present invention, the in-plane refractive index difference between the first translucent optical film and the adhesive layer may be large, and the in-plane refractive index difference between the second translucent optical film and the adhesive layer may be large. That is, a translucent optical film having a high refractive index can be used as the first translucent optical film or the second translucent optical film. Conventionally, optical laminates in which two translucent optical films having high refractive indexes are bonded together with an adhesive have had noticeable reflection unevenness in external light reflection. However, according to the present invention, reflection unevenness in external light reflection can be effectively reduced even when a translucent optical film having a high refractive index is used as the first translucent optical film or the second translucent optical film.

[0027] The in-plane refractive index difference (absolute value) between the first light-transmitting optical film and the adhesive layer is preferably 0.05 or more, and may be 0.08 or more, 0.10 or more, 0.12 or more, 0.14 or more, or 0.16 or more. The upper limit of the in-plane refractive index difference (absolute value) between the first light-transmitting optical film and the adhesive layer is, for example, 0.26 or less.

[0028] The in-plane refractive index difference (absolute value) between the second light-transmitting optical film and the adhesive layer is preferably 0.05 or more, and may be 0.08 or more, 0.10 or more, 0.12 or more, 0.14 or more, or 0.16 or more. The upper limit of the in-plane refractive index difference (absolute value) between the second light-transmitting optical film and the adhesive layer is, for example, 0.26 or less.

[0029] <1-1.Translucent optical film> The first light-transmitting optical film and the second light-transmitting optical film (for convenience of explanation, these two light-transmitting optical films may be simply referred to as "light-transmitting optical films") may be the same type of light-transmitting optical film or different types of light-transmitting optical films.

[0030] The thickness of each of the first light-transmitting optical film and the second light-transmitting optical film may be any appropriate thickness as long as the effects of the present invention are not impaired. Such a thickness is, for example, 0.5 μm to 200 μm, or may be 1 μm to 100 μm, or may be 1 μm to 50 μm. From the viewpoint of thinning, the thickness of the light-transmitting optical film is, for example, 0.5 μm to 50 μm, or may be 1 μm to 40 μm, or may be 1 μm to 30 μm, or may be 1 μm to 20 μm, or may be 1 μm to 10 μm, or may be 1 μm to 5 μm.

[0031] The in-plane refractive index of the first translucent optical film is preferably 1.50 or more, and may be 1.52 or more, 1.54 or more, 1.56 or more, 1.58 or more, 1.60 or more, 1.61 or more, or 1.62 or more. The upper limit of the in-plane refractive index of the first translucent optical film tends to be higher, but based on practical material selection, etc., it is, for example, 1.72 or less. The optical laminate according to the embodiment of the present invention can effectively reduce reflection unevenness of external light reflection even when the in-plane refractive index of the first translucent optical film is as high as described above. The in-plane refractive index of the second translucent optical film is preferably 1.50 or more, and may be 1.52 or more, 1.54 or more, 1.56 or more, 1.58 or more, 1.60 or more, 1.61 or more, or 1.62 or more. The upper limit of the in-plane refractive index of the second translucent optical film tends to be higher, but based on practical material selection, etc., it is, for example, 1.72 or less. The optical laminate according to the embodiment of the present invention can effectively reduce reflection unevenness of external light reflection even when the in-plane refractive index of the second translucent optical film is as high as described above.

[0032] As the light-transmissive optical film, any appropriate light-transmissive optical film can be adopted as long as the effects of the present invention are not impaired. Examples of such light-transmissive optical films include retardation films (retardation layers), polarizers, polarizing films (laminated films including polarizers and polarizer protective films), polarizer protective films, brightness enhancement films, and resin base films.

[0033] As the material constituting the light-transmissive optical film, any appropriate material can be adopted as long as the effects of the present invention are not impaired. Examples of such materials include polycarbonate resins (including polyester carbonate resins), polyester resins (such as PET), polyvinyl acetal resins, polyarylate resins, polyolefin resins, cyclic polyolefin resins (e.g., norbornene resins), cycloolefin resins, cellulose resins, polyvinyl alcohol resins, polyamide resins, polyimide resins, polyether resins, polystyrene resins, acrylic resins, and polyvinyl alcohol resins. These resins may be used alone or in combination of two or more (e.g., blended or copolymerized).

[0034] One of the preferred embodiments of the present invention is that at least one of the first light-transmissive optical film and the second light-transmissive optical film is a retardation film, and both the first light-transmissive optical film and the second light-transmissive optical film may be retardation films. When both the first light-transmissive optical film and the second light-transmissive optical film are retardation films, combinations of a λ / 2 plate and a λ / 4 plate, or a λ / 3 plate and a λ / 6 plate, a λ / 2 plate and a C plate, or a λ / 4 plate and a C plate may be used. Here, an optical element with a relationship of in-plane refractive indices nx, ny and refractive index nz in the thickness direction of nx = ny > nz is called a negative C plate, and an optical element with nx = ny < nz is called a positive C plate. These are collectively called C plates. Here, "nx = ny" includes not only the case where nx and ny are exactly equal but also the case where nx and ny are substantially equal. That is, the in-plane retardation Re(550) of the retardation film can be 20 nm or less, preferably 10 nm or less, and more preferably 5 nm or less.

[0035] The light-transmitting optical film may have any appropriate treatment layer formed on its surface, as long as the effects of the present invention are not impaired. Examples of such treatment layers include a hard coat layer, an easy-adhesion layer, an anti-reflection treatment, an anti-glare treatment, and an anti-sticking treatment layer.

[0036] The surface of the light-transmitting optical film may be subjected to any appropriate activation treatment within the scope of the present invention, for the purpose of improving adhesiveness, etc. Examples of such activation treatments include corona treatment, plasma treatment, saponification treatment, and low-pressure UV treatment.

[0037] The light-transmitting optical film may be a stretched film. Generally, optical anisotropy is imparted to a retardation film or a polarizer by orienting a polymer chain or a dichroic material through stretching. In the present invention, an optical laminate may be produced using a light-transmitting optical film that has been stretched in advance to impart optical anisotropy, or an optical laminate produced using a light-transmitting optical film may be stretched to impart optical anisotropy.

[0038] The light-transmitting optical film may contain any appropriate additives as long as the effects of the present invention are not impaired. Such additives may be one type only or two or more types. Examples of such additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, color inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, and colorants.

[0039] As described above, any appropriate light-transmitting optical film can be used as the light-transmitting optical film as long as the effects of the present invention are not impaired. Hereinafter, as one embodiment of the light-transmitting optical film, a case where the light-transmitting optical film is a retardation film will be described.

[0040] <1-1-a. First retardation film> When the first light-transmitting optical film is a retardation film, it is referred to as a first retardation film.

[0041] In one embodiment, the first retardation film has a refractive index characteristic that satisfies the relationship nx>ny, where the relationship between ny and nz is ny<nz、ny=nz、ny> In one embodiment, the first retardation film may function as a λ / 2 plate. In one embodiment, the first retardation film may function as a λ / 3 plate.

[0042] In one embodiment, the first retardation film has a refractive index characteristic that exhibits a relationship of nx=ny, where the relationship between nx and nz is<nz、n> In one embodiment, the first retardation film may function as a C-plate.

[0043] The first retardation film may be, for example, a retardation film that is a λ / 2 plate having a front retardation of 200 nm or more and a thickness direction retardation of 0 nm or more. The front retardation is usually controlled in the range of 200 nm to 350 nm, and the thickness direction retardation is usually controlled in the range of 0 nm to 450 nm. Another example is a retardation film that is a C plate having a front retardation of 0 nm and a thickness direction retardation of -50 nm or less or 50 nm or more. The front retardation is usually controlled in the range of -10 nm to 10 nm, and the thickness direction retardation is usually controlled in the range of -200 nm to 200 nm.

[0044] The first retardation film may exhibit an inverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light, may exhibit a positive wavelength dispersion characteristic in which the retardation value decreases according to the wavelength of the measurement light, or may exhibit a flat wavelength dispersion characteristic in which the retardation value changes little depending on the wavelength of the measurement light.

[0045] As the first retardation film, for example, when the in-plane retardation measured with light of wavelengths of 450 nm and 550 nm at 23° C. is Re(450) and Re(550), respectively, and the refractive indices of the retardation film in the slow axis direction and the fast axis direction are nx and ny, respectively, the in-plane birefringence, nx-ny, is Δn, and when nz is the refractive index in the thickness direction of the retardation film, the ratio of nx-nz, which is the thickness direction birefringence, to nx-ny, which is the in-plane birefringence, is NZ, 1.00 <Re(450) / Re(550)<1.20 0.08<Δn<0.15 1.00 <NZ<1.20 It may be a retardation film of a positive wavelength dispersion type that satisfies the above.

[0046] The Re(550) of the first retardation film is, for example, 130 nm to 350 nm, may be 160 nm to 330 nm, or may be 200 nm to 300 nm.

[0047] The first retardation film is formed of any appropriate material that can satisfy the above characteristics. The first retardation film can be composed of, for example, a resin film or an oriented and solidified layer of a liquid crystal compound, and is preferably an oriented and solidified layer of a liquid crystal compound. By using an oriented and solidified layer of a liquid crystal compound as the retardation film, it is possible to achieve a desired in-plane retardation with a thickness that is significantly thinner than that of a resin film. As a result, it is possible to significantly reduce the thickness of the optical laminate.

[0048] Examples of resins contained in the resin film include polycarbonate resins (including polyester carbonate resins), polyester resins, polyvinyl acetal resins, polyarylate resins, polyolefin resins, cyclic polyolefin resins (e.g., norbornene resins), cycloolefin resins, cellulose resins, polyvinyl alcohol resins, polyamide resins, polyimide resins, polyether resins, polystyrene resins, acrylic resins, and polyvinyl alcohol resins. These resins may be used alone or in combination (e.g., blends or copolymers).

[0049] When the first retardation film exhibits reverse dispersion wavelength characteristics, a resin film containing a polycarbonate-based resin (including polyester carbonate-based resin) can be suitably used.

[0050] Any suitable polycarbonate-based resin may be used as the polycarbonate-based resin as long as it does not impair the effects of the present invention. The polycarbonate-based resin may, for example, contain structural units derived from a fluorene-based dihydroxy compound, structural units derived from an isosorbide-based dihydroxy compound, and structural units derived from at least one dihydroxy compound selected from the group consisting of alicyclic diols, alicyclic dimethanols, di-, tri-, or polyethylene glycols, and alkylene glycols or spiroglycols. The polycarbonate-based resin preferably contains structural units derived from a fluorene-based dihydroxy compound, structural units derived from an isosorbide-based dihydroxy compound, structural units derived from an alicyclic dimethanol, and / or structural units derived from di-, tri-, or polyethylene glycol; more preferably, it contains structural units derived from a fluorene-based dihydroxy compound, structural units derived from an isosorbide-based dihydroxy compound, and structural units derived from di-, tri-, or polyethylene glycol. The polycarbonate-based resin may also contain structural units derived from other dihydroxy compounds, as needed. Details of polycarbonate-based resins that can be suitably used for the first retardation film are described in, for example, JP 2014-10291 A, JP 2014-26266 A, JP 2015-212816 A, JP 2015-212817 A, and JP 2015-212818 A, and the descriptions of these publications are incorporated herein by reference.

[0051] When the first retardation film exhibits flat wavelength dispersion characteristics, a resin film containing a cycloolefin resin can be suitably used.

[0052] Cycloolefin resin is a general term for resins polymerized using cycloolefin as a polymerization unit, and examples thereof include those described in JP-A-1-240517, JP-A-3-14882, and JP-A-3-122137. Examples of cycloolefin resins include ring-opening (co)polymers of cycloolefins, addition polymers of cycloolefins, copolymers (typically random copolymers) of cycloolefins with α-olefins such as ethylene and propylene, graft-modified products of these modified with unsaturated carboxylic acids or their derivatives, and hydrogenated products thereof. Specific examples of cycloolefins include norbornene-based monomers.Examples of norbornene-based monomers include norbornene and its alkyl and / or alkylidene substituted derivatives and polar group substituted derivatives such as halogen (e.g., 5-methyl-2-norbornene, 5-dimethyl-2-norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5-ethylidene-2-norbornene), dicyclopentadiene, 2,3-dihydrodicyclopentadiene, dimethanooctadecane, and the like. Hydronaphthalene and its alkyl and / or alkylidene substituted derivatives and polar group substituted derivatives such as halogen (e.g., 6-methyl-1,4:5,8-dimethano-1,4,4a,5,6,7,8,8a-octahydronaphthalene, 6-ethyl-1,4:5,8-dimethano-1,4,4a,5,6,7,8,8a-octahydronaphthalene, 6-ethylidene-1,4:5,8-dimethano-1,4,4a,5,6,7,8, 8a-Octahydronaphthalene, 6-chloro-1,4:5,8-dimethano-1,4,4a,5,6,7,8,8a-octahydronaphthalene, 6-cyano-1,4:5,8-dimethano-1,4,4a,5,6,7,8,8a-octahydronaphthalene, 6-pyridyl-1,4:5,8-dimethano-1,4,4a,5,6,7,8,8a-octahydronaphthalene, 6-methoxycarbonyl-1,4:5,8-dimethano Examples of suitable cycloolefins include 4,9:5,8-dimethano-3a,4,4a,5,8,8a,9,9a-octahydro-1H-benzoindene and 4,11:5,10:6,9-trimethano-3a,4,4a,5,5a,6,9,9a,10,10a,11,11a-dodecahydro-1H-cyclopentaanthracene. Other cycloolefins capable of ring-opening polymerization may be used in combination. Examples of such other cycloolefins include compounds having one reactive double bond, such as cyclopentene, cyclooctene, and 5,6-dihydrodicyclopentadiene.

[0053] Various cycloolefin resin products are commercially available. Specific examples of commercially available cycloolefin resin products include "ZEONEX" and "ZEONOR" manufactured by Zeon Corporation, "Arton" manufactured by JSR Corporation, "TOPUS" manufactured by TICONA, and "APEL" manufactured by Mitsui Chemicals, Inc.

[0054] The first retardation film made of a resin film can be obtained, for example, by stretching an unstretched resin film. Any appropriate stretching method, stretching conditions (e.g., stretching temperature, stretching ratio, stretching direction), and stretching direction can be employed for stretching. The stretching temperature is, for example, Tg-30°C to Tg+60°C, and may be Tg-10°C to Tg+50°C, relative to the glass transition temperature (Tg) of the resin film. In one embodiment, the first retardation film can be obtained by uniaxially stretching or fixed-end uniaxially stretching an unstretched resin film. A specific example of fixed-end uniaxial stretching is a method in which a resin film is stretched in the width direction (transverse direction) while traveling in the longitudinal direction. The stretching ratio is preferably 1.1 to 3.5. The thickness of the first retardation film made of a resin film is, for example, 10 μm to 100 μm, may be 10 μm to 70 μm, may be 10 μm to 60 μm, or may be 20 μm to 50 μm.

[0055] When the first retardation film is composed of an oriented and solidified layer of a liquid crystal compound, the first retardation film is typically oriented in a state where rod-shaped liquid crystal compounds are aligned in the slow axis direction of the first retardation film (homogeneous orientation). Examples of rod-shaped liquid crystal compounds include liquid crystal polymers and liquid crystal monomers. The liquid crystal compound is preferably polymerizable. If the liquid crystal compound is polymerizable, the orientation state of the liquid crystal compound can be fixed by aligning the liquid crystal compound and then polymerizing it.

[0056] An alignment and solidification layer of a liquid crystal compound (liquid crystal alignment and solidification layer) can be formed by performing an alignment treatment on the surface of a predetermined substrate, applying a coating liquid containing a liquid crystal compound to the surface to align the liquid crystal compound in a direction corresponding to the alignment treatment, and fixing the alignment state. Any appropriate alignment treatment can be used as the alignment treatment. Examples of the alignment treatment include mechanical alignment treatment, physical alignment treatment, and chemical alignment treatment. Specific examples of mechanical alignment treatment include rubbing treatment and stretching treatment. Specific examples of physical alignment treatment include magnetic field alignment treatment and electric field alignment treatment. Specific examples of chemical alignment treatment include oblique deposition and photoalignment treatment. Any appropriate treatment conditions can be used for the alignment treatment depending on the purpose.

[0057] The alignment of the liquid crystal compound can be achieved by treating the liquid crystal compound at a temperature at which the liquid crystal compound exhibits a liquid crystal phase depending on the type of liquid crystal compound. By performing such temperature treatment, the liquid crystal compound assumes a liquid crystal state and is aligned in accordance with the alignment treatment direction of the substrate surface.

[0058] In one embodiment, the alignment state is fixed by cooling the aligned liquid crystal compound. When the liquid crystal compound is polymerizable or crosslinkable, the alignment state is fixed by subjecting the aligned liquid crystal compound to a polymerization treatment or a crosslinking treatment.

[0059] Any suitable liquid crystal polymer and / or liquid crystal monomer can be used as the liquid crystal compound. The liquid crystal polymer and liquid crystal monomer may each be one type only, or two or more types. Specific examples of liquid crystal compounds and methods for producing a liquid crystal alignment solidified layer are described in, for example, JP 2006-163343 A, JP 2006-178389 A, and WO 2018 / 123551 A. The descriptions in these publications are incorporated herein by reference.

[0060] When the first retardation film is composed of a layer of fixed alignment of a liquid crystal compound, the thickness of the first retardation film, which is a layer of fixed alignment of a liquid crystal compound, is, for example, 0.5 μm to 10 μm, or may be 0.5 μm to 8 μm, or 0.5 μm to 6 μm, or may be 0.5 μm to 4 μm.

[0061] <1-1-b. Second retardation film> When the second light-transmitting optical film is a retardation film, it is referred to as a second retardation film.

[0062] In one embodiment, the second retardation film has a refractive index characteristic that satisfies the relationship nx>ny, where the relationship between ny and nz is ny<nz、ny=nz、ny> In one embodiment, the second retardation film may function as a λ / 4 plate. In another embodiment, the second retardation film may function as a λ / 5 plate or a λ / 6 plate.

[0063] In one embodiment, the second retardation film has a refractive index characteristic that exhibits a relationship of nx=ny, where the relationship between nx and nz is<nzまたはnx> In one embodiment, the second retardation film may function as a C-plate.

[0064] The second retardation film may be, for example, a λ / 4 plate having a front retardation of 90 nm or more and a thickness retardation of 0 nm or more. The front retardation is usually controlled within a range of 90 nm to 200 nm, and the thickness retardation is usually controlled within a range of 0 nm to 240 nm. Another example is a C-plate retardation film having a front retardation of 0 nm and a thickness retardation of −50 nm or less or 50 nm or more. The front retardation is usually controlled within a range of −10 nm to 10 nm, and the thickness retardation is usually controlled within a range of −200 nm to 200 nm.

[0065] The second retardation film may exhibit an inverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light, may exhibit a positive wavelength dispersion characteristic in which the retardation value decreases according to the wavelength of the measurement light, or may exhibit a flat wavelength dispersion characteristic in which the retardation value hardly changes depending on the wavelength of the measurement light.

[0066] As the second retardation film, for example, when the in-plane retardation measured with light of wavelengths of 450 nm and 550 nm at 23° C. is Re(450) and Re(550), respectively, and the refractive indices of the retardation film in the slow axis direction and the fast axis direction are nx and ny, respectively, the in-plane birefringence, nx-ny, is Δn, and when nz is the refractive index in the thickness direction of the retardation film, the ratio of nx-nz, which is the birefringence in the thickness direction, to nx-ny, which is the in-plane birefringence, is NZ, 1.00 <Re(450) / Re(550)<1.20 0.08<Δn<0.15 1.00 <NZ<1.20 It may be a retardation film of a positive wavelength dispersion type that satisfies the above.

[0067] The Re(550) of the second retardation film is, for example, 70 nm to 200 nm, may be 90 nm to 160 nm, or may be 120 nm to 140 nm.

[0068] The arrangement order of the first retardation film and the second retardation film may be reversed.

[0069] The second retardation film is formed of any appropriate material that can satisfy the above characteristics. The second retardation film can be composed of, for example, a resin film or an oriented and solidified layer of a liquid crystal compound, and is preferably an oriented and solidified layer of a liquid crystal compound. By using an oriented and solidified layer of a liquid crystal compound as the retardation film, it is possible to achieve a desired in-plane retardation with a thickness that is significantly thinner than that of a resin film. As a result, it is possible to significantly reduce the thickness of the optical laminate.

[0070] The second retardation film made of a resin film may be described in the same manner as the first retardation film made of a resin film. The second retardation film made of a layer of a liquid crystal compound with a fixed orientation may be described in the same manner as the first retardation film made of a layer of a liquid crystal compound with a fixed orientation.

[0071] <1-2.Adhesive layer> The adhesive layer may be formed from any suitable adhesive as long as the effects of the present invention are not impaired. Examples of such adhesive layers include an aqueous adhesive solution and an active energy ray-curable adhesive.

[0072] In order to further enhance the effects of the present invention, the adhesive layer is preferably formed from an aqueous adhesive solution. Examples of aqueous adhesive solutions include a solution containing polyvinyl alcohol and a solution containing at least one amino compound. The solution containing at least one amino compound may be a solution containing at least one amino compound and an epoxy compound. By employing such an adhesive layer and making the adhesive layer very thin, as described above, the reflection unevenness of external light reflection can be more effectively reduced. In particular, even if there is a large difference in refractive index between the adhesive layer and the translucent optical film attached adjacent to it, the reflection unevenness of external light reflection can be more effectively reduced.

[0073] In one embodiment, the solution containing polyvinyl alcohol may contain a metal compound colloid. The metal compound colloid is a dispersion of metal compound fine particles in a dispersion medium, which is electrostatically stabilized due to mutual repulsion of like-charged particles of the fine particles, and may have permanent stability.

[0074] The average particle size of the fine particles forming the metal compound colloid can be set to any appropriate value as long as it does not adversely affect optical properties such as transparency and polarization characteristics. It is preferably 1 nm to 100 nm, and more preferably 1 nm to 50 nm, because this allows the fine particles to be uniformly dispersed in the adhesive layer.

[0075] Any suitable compound can be used as the metal compound. Examples include metal oxides such as alumina, silica, zirconia, and titania; metal salts such as aluminum silicate, calcium carbonate, magnesium silicate, zinc carbonate, barium carbonate, and calcium phosphate; and minerals such as celite, talc, clay, and kaolin. A colloidal metal compound having a positive charge is preferably used as the metal compound. Examples of such metal compounds include alumina and titania, with alumina being particularly preferred.

[0076] The adhesive layer formed from a solution containing at least one amino compound preferably contains an organosilicon compound.

[0077] As the amino compound that can be contained in the aqueous adhesive solution, any appropriate amino compound can be adopted as long as it does not impair the effects of the present invention. The amino compound may be only one type or two or more types. Examples of such amino compounds include amino-based silane coupling agents.

[0078] As amino-based silane coupling agent, as long as it is the organosilicon compound having amino group, can adopt any suitable amino-based silane coupling agent within the scope that does not impair the effect of the present invention.As this amino-based silane coupling agent, for example, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane, N-2-(aminoethyl)-3-aminopropyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyldiethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyldimethylmethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and their hydrochlorides can be enumerated. Commercially available amino silane coupling agents include, for example, KBM-602, KBM-603, KBM-903, KBE-603, KBE-903, and X-12-972F (all manufactured by Shin-Etsu Chemical Co., Ltd.), Z-6011, Z-6020, Z-6026, Z-6032, Z-6094, and Z-6610 (all manufactured by Dow Corning Toray Co., Ltd.), and A-1100, A-1110, A-1120, A-2120, and Y-9669 (all manufactured by Momentive Performance Materials).

[0079] As the amino compound that can be contained in the aqueous adhesive solution, in addition to an amino-based silane coupling agent, a compound having an amino group at the terminal is preferable, and examples thereof include polyethyleneimine, polyetheramine, etc. Commercially available polyethyleneimine products include, for example, SP-200, P-1000, and SP-006 (all manufactured by Nippon Shokubai Co., Ltd.), and commercially available polyetheramine products include, for example, PEA D230, PEA D400, and PEA D2000 (all manufactured by Mitsui Fine Chemicals, Inc.).

[0080] As the epoxy compound that can be contained in the aqueous adhesive solution, any appropriate epoxy compound can be used as long as it does not impair the effects of the present invention. The epoxy compound may be one type or two or more types. Examples of such epoxy compounds include epoxy-based silane coupling agents.

[0081] As the epoxy silane coupling agent, as long as it is the organosilicon compound having epoxy group, any suitable epoxy silane coupling agent can be adopted within the scope that does not impair the effect of the present invention.As this epoxy silane coupling agent, for example, 2-(3,4-epoxycyclohexyl) ethyl methyl dimethoxysilane, 2-(3,4-epoxycyclohexyl) ethyl methyl diethoxysilane, 2-(3,4-epoxycyclohexyl) ethyl trimethoxysilane, 2-(3,4-epoxycyclohexyl) ethyl triethoxysilane, 3-glycidoxypropyl methyl dimethoxysilane, 3-glycidoxypropyl methyl diethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl triethoxysilane. Commercially available epoxy silane coupling agents include, for example, KBM-303, KBM-402, KBM-403, KBE-402, KBE-403, KR-516, and X-12-981S (all manufactured by Shin-Etsu Chemical Co., Ltd.), SH6040, Z-6040, Z-6042, Z-6043, and Z-6044 (all manufactured by Dow Corning Toray Co., Ltd.), and A-186, A-187, and A-1871 (all manufactured by Momentive Performance Materials).

[0082] Examples of epoxy compounds that can be contained in the aqueous adhesive solution include, in addition to epoxy silane coupling agents, sorbitol polyglycidyl ethers and water-soluble epoxy resins. Commercially available epoxy compounds include Denacol EX-612, EX-614, and EX-622 (all manufactured by Nagase ChemteX Corporation), W2801, W2821R70, and WD11M60 (all manufactured by Mitsubishi Chemical Corporation).

[0083] When the aqueous adhesive solution contains at least one amino compound and one epoxy compound, the molar ratio of the amino compound to the epoxy compound in the aqueous adhesive solution is preferably 8:92 to 60:40, or alternatively 10:90 to 55:45, 15:85 to 50:50, 20:80 to 45:55, or 25:75 to 40:60. When the molar ratio of the amino compound to the epoxy compound in the aqueous adhesive solution is within the above range, the effects of the present invention can be more effectively exhibited.

[0084] The total content of the amino compound and the epoxy compound in the aqueous adhesive solution is preferably less than 50% by weight, and may be 0.01% by weight to 40% by weight, 0.1% by weight to 30% by weight, 0.1% by weight to 20% by weight, 0.3% by weight to 10% by weight, 0.4% by weight to 5% by weight, or 0.5% by weight to 2% by weight.

[0085] The aqueous adhesive solution may contain a solvent. The solvent may be a single solvent or a mixed solvent. Examples of the solvent include water and organic solvents. Examples of the organic solvent include esters such as ethyl acetate, butyl acetate, and 2-hydroxyethyl acetate; ketones such as methyl ethyl ketone, acetone, cyclohexanone, methyl isobutyl ketone, diethyl ketone, methyl-n-propyl ketone, and acetylacetone; cyclic ethers such as tetrahydrofuran (THF) and dioxane; aliphatic or alicyclic hydrocarbons such as n-hexane and cyclohexane; aromatic hydrocarbons such as toluene and xylene; aliphatic or alicyclic alcohols such as methanol, ethanol, n-propanol, isopropanol, and cyclohexanol; glycol ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and diethylene glycol monoethyl ether; and glycol ether acetates such as diethylene glycol monomethyl ether acetate and diethylene glycol monoethyl ether acetate.

[0086] The solvent preferably contains water, and the water content in the solvent is preferably 50% to 100% by weight, but may be 60% to 100% by weight, 70% to 100% by weight, 80% to 100% by weight, 90% to 100% by weight, 95% to 100% by weight, 98% to 100% by weight, or even substantially 100% by weight. When the solvent contains water in the above range (typically, a water-based adhesive), the solvent evaporates easily when the water-based adhesive solution is applied and dried, making it easier to achieve a thinner film. Furthermore, water causes less damage to polarizers and translucent optical films, and is therefore effective in preventing deterioration of product quality when, for example, an optical component including an optical laminate according to an embodiment of the present invention and a polarizer is produced.

[0087] The solvent may not contain aliphatic or alicyclic alcohols. The content of aliphatic or alicyclic alcohols in the solvent is preferably 0% by weight to 50% by weight, and may be 0% by weight to 40% by weight, 0% by weight to 30% by weight, 0% by weight to 20% by weight, 0% by weight to 10% by weight, 0% by weight to 5% by weight, 0% by weight to 2% by weight, or substantially 0% by weight.

[0088] The content of the solvent in the aqueous adhesive solution is preferably 50% by weight or more, and may be 60% by weight to 99.99% by weight, 70% by weight to 99.9% by weight, 80% by weight to 99.8% by weight, 90% by weight to 99.7% by weight, 95% by weight to 99.6% by weight, or 98% by weight to 99.5% by weight.

[0089] The aqueous adhesive solution may contain any appropriate additives as long as they do not impair the effects of the present invention. Such additives may be used alone or in combination of two or more. Examples of such additives include binder resins, surfactants, plasticizers, tackifiers, low-molecular-weight polymers, polymerizable monomers, surface lubricants, leveling agents, antioxidants, corrosion inhibitors, light stabilizers, UV absorbers, polymerization inhibitors, silane coupling agents, titanium coupling agents, inorganic or organic fillers, metal powders, particles, and foil-like materials. Examples of binder resins include acrylic resins, styrene resins, polyvinyl alcohol resins, urethane resins, polyester resins, polypropylene resins, polyethylene resins, epoxy resins, and polycarbonate resins.

[0090] The content of the additive in the aqueous adhesive solution is preferably 0% by weight to 10% by weight, and may be 0% by weight to 5% by weight, 0% by weight to 3% by weight, 0% by weight to 2% by weight, 0% by weight to 1% by weight, or 0% by weight to 0.5% by weight.

[0091] 2. Manufacturing of optical laminates The optical laminate according to the embodiment of the present invention can be produced by any appropriate method as long as the effects of the present invention are not impaired.

[0092] In one embodiment of the method for producing an optical laminate according to the present invention, an aqueous adhesive solution for forming an adhesive layer is applied onto a first light-transmitting optical film to form a coating film, and then the solvent contained in the aqueous adhesive solution is removed by drying as necessary. A second light-transmitting optical film is laminated onto the formed coating film, and the coating film between the first light-transmitting optical film and the second light-transmitting optical film is heat-pressed to form an adhesive layer, thereby producing an optical laminate in which the first light-transmitting optical film and the second light-transmitting optical film are bonded together by the adhesive layer.

[0093] In another embodiment of the method for producing an optical laminate according to the present invention, an aqueous adhesive solution for forming an adhesive layer is applied onto a first light-transmitting optical film to form a coating film, and then a second light-transmitting optical film is laminated on the formed coating film, and if necessary, the solvent contained in the aqueous adhesive solution is removed by drying, and the coating film between the first light-transmitting optical film and the second light-transmitting optical film is cured to form an adhesive layer, thereby producing an optical laminate in which the first light-transmitting optical film and the second light-transmitting optical film are bonded together via the adhesive layer.

[0094] In yet another embodiment of the method for producing an optical laminate according to the present invention, an aqueous adhesive solution for forming an adhesive layer is applied onto a first light-transmitting optical film to form a coating film, and an aqueous adhesive solution for forming an adhesive layer is applied onto a second light-transmitting optical film to form a coating film, the first light-transmitting optical film on which the coating film has been formed and the second light-transmitting optical film on which the coating film has been formed are laminated together with the coating film facing inward, and the solvent contained in the aqueous adhesive solution is removed by drying as necessary, and the coating film between the first light-transmitting optical film and the second light-transmitting optical film is cured to form an adhesive layer, thereby producing an optical laminate in which the first light-transmitting optical film and the second light-transmitting optical film are bonded together with the adhesive layer.

[0095] In yet another embodiment of the method for producing an optical laminate according to the present invention, an aqueous adhesive solution is poured so that the first and second light-transmitting optical films are sandwiched between them, and then the films are passed between a pair of laminating rolls, and if necessary, the solvent contained in the aqueous adhesive solution is removed by drying, and the coating film between the first and second light-transmitting optical films is cured to form an adhesive layer, thereby producing an optical laminate in which the first and second light-transmitting optical films are bonded together with the adhesive layer.

[0096] The method for producing an optical laminate according to an embodiment of the present invention is not limited to the above-exemplified embodiment, of course.

[0097] Any appropriate method can be used to apply the aqueous adhesive solution for forming an adhesive layer on the first light-transmitting optical film as long as the effects of the present invention are not impaired. Examples of such application methods include a method of immersing the first light-transmitting optical film in the aqueous adhesive solution (dip coating), curtain coating, spray coating, bar coating, rod coating, roll coating, die coating, and gravure coating.

[0098] Before applying an aqueous adhesive solution for forming an adhesive layer onto the first translucent optical film, the surface of the first translucent optical film may be subjected to any appropriate activation treatment within a range that does not impair the effects of the present invention. Examples of such activation treatments include corona treatment, plasma treatment, saponification treatment, and low-pressure UV treatment. In particular, when a first translucent optical film made of a material that does not have polar groups is used, polar groups such as hydroxyl groups may be introduced into the surface of the first translucent optical film by the activation treatment.

[0099] When an aqueous adhesive solution for forming an adhesive layer is applied to a first light-transmitting optical film to form a coating film, and then the solvent contained in the molecular adhesive solution is removed by drying, any appropriate drying method can be used as long as the effects of the present invention are not impaired. Examples of such drying methods include heat drying. Conditions such as temperature and time for heat drying can be any appropriate conditions depending on the composition of the molecular adhesive solution, etc. Examples of such conditions include a heating temperature of 35°C to 120°C and a heating time of 30 seconds to 10 minutes.

[0100] Before laminating a second light-transmitting optical film on the coating film formed on the first light-transmitting optical film, the surface of the second light-transmitting optical film may be subjected to any appropriate activation treatment within a range that does not impair the effects of the present invention. Examples of such activation treatments include corona treatment, plasma treatment, saponification treatment, and low-pressure UV treatment. In particular, when a second light-transmitting optical film made of a material that does not have polar groups is used, polar groups such as hydroxyl groups may be introduced into the surface of the first light-transmitting optical film by the activation treatment.

[0101] As a method for laminating the second light-transmitting optical film on the coating film formed on the first light-transmitting optical film, any appropriate lamination method can be adopted as long as it does not impair the effects of the present invention. Examples of such lamination methods include lamination by pressure using a laminator or the like.

[0102] Before lamination, the first translucent optical film may have another film (for example, a supporting substrate) laminated on the surface opposite to the surface on which the adhesive layer is provided. Before lamination, the second translucent optical film may have another film (for example, a supporting substrate) laminated on the surface opposite to the surface on which the adhesive layer is provided. Such a supporting substrate may be finally peeled off and removed, or may be used as another optical film to be further laminated on the optical laminate according to the embodiment of the present invention.

[0103] Any appropriate curing method can be used to cure the coating between the first and second light-transmitting optical films to form an adhesive layer, as long as the effects of the present invention are not impaired. Examples of such curing methods include curing by heating. Conditions for curing by heating, such as temperature and time, can be any appropriate conditions depending on the composition of the molecular adhesive solution. Examples of such conditions include a heating temperature of 40°C to 150°C and a heating time of 1 minute to 20 minutes.

[0104] 3. Uses of optical laminates The optical laminate according to the embodiment of the present invention can be used for any suitable application. The optical laminate according to the embodiment of the present invention can be used, for example, in an image display device such as a liquid crystal display device or an organic EL display device. That is, the image display device according to the embodiment of the present invention includes the optical laminate according to the embodiment of the present invention.

[0105] The optical laminate according to the embodiment of the present invention can be used by laminating any other appropriate optical film, and can be used by providing any other appropriate layer. Examples of other optical films include a retardation film, a polarizer, a polarizing film (a laminate film including a polarizer and a polarizer protective film), a polarizer protective film, a brightness enhancement film, and a resin substrate film. Examples of other layers include a pressure-sensitive adhesive layer, another adhesive layer, a hard coat layer, an anti-reflection layer, and an anti-glare layer.

[0106] Fig. 2 is a schematic cross-sectional view of one embodiment of an optical member including an optical laminate according to an embodiment of the present invention. The optical member 1000 shown in Fig. 2 includes a polarizing film 40, an adhesive layer 50, an optical laminate 100 according to an embodiment of the present invention (a first light-transmitting optical film 10, an adhesive layer 30, and a second light-transmitting optical film 20), and a panel-side pressure-sensitive adhesive layer 60. The panel-side pressure-sensitive adhesive layer 60 enables the optical member 1000 to be attached to an image display cell, thereby constituting an image display device.

[0107] The image display device according to the embodiment of the present invention can be manufactured, for example, by appropriately assembling the optical laminate according to the embodiment of the present invention with other optical films, an image display cell, a backlight, etc., and incorporating a drive circuit. In the configuration of the image display device according to the embodiment of the present invention, the optical laminate according to the embodiment of the present invention can be used on one or both sides of the image display cell. [Example]

[0108] The present invention will be specifically described below using examples, but the present invention is not limited to these examples. The test and evaluation methods used in the examples are as follows. The term "parts" means "parts by weight" unless otherwise specified, and the term "%" means "% by weight" unless otherwise specified.

[0109] <Measurement of adhesive layer thickness> Using a Hitachi High-Technologies Corporation "HT7820" device, cross-sectional TEM observation was performed using the frozen ultrathin sectioning method including heavy metal staining to measure the thickness of the adhesive layer. The accelerating voltage during the measurement was 100 kV.

[0110] <Refractive index measurement> The refractive index of the adhesive layer was measured using an ellipsometer (manufactured by J.A. Woollam Japan, trade name "RC2") after preparing a thin adhesive layer 200 nm thick on an acrylic film (manufactured by Mitsubishi Chemical Corporation, trade name "Acryplene", thickness: 20 μm).

[0111] <Evaluation of uneven reflection> [Evaluation 1] An adhesive tape was attached to the second light-transmitting optical film surface of the optical laminate obtained in the Examples and Comparative Examples, and then the laminate was attached to a black acrylic plate. When a carrier was laminated on the light-transmitting optical film, the carrier film was peeled off before the laminate was attached to the acrylic plate. A fluorescent lamp was lit from the first light-transmitting optical film side, and observation was performed. The adhesive tape used was prepared by the following method. [Preparation of Acrylic Polymer] A four-neck flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser was charged with 92 parts by weight of butyl acrylate, 5 parts by weight of N-acryloylmorpholine (ACMO), 2.9 parts by weight of acrylic acid, 0.1 parts by weight of 2-hydroxyethyl acrylate, 0.1 parts by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator, and 200 parts by weight of ethyl acetate. Nitrogen gas was introduced while gently stirring to replace the atmosphere. The liquid temperature in the flask was maintained at around 55°C, and the polymerization reaction was carried out for 8 hours to prepare an acrylic polymer solution. The weight-average molecular weight of the resulting acrylic polymer was 1.78 million. [Preparation of adhesive tape] The acrylic polymer solution obtained above was applied to one side of a silicone-treated polyethylene terephthalate (PET) film (manufactured by Mitsubishi Chemical, thickness = 38 μm), and dried and crosslinked at 150 °C for 3 minutes to form a pressure-sensitive adhesive layer with a thickness of 5 μm after drying. The gel fraction of the pressure-sensitive adhesive layer at this time was 83 wt %, and the amount of decomposed peroxide after drying was 91 wt %. [Evaluation 2] In Evaluation 1, an irradiation-side linear polarizer was attached to the irradiation direction side of the fluorescent lamp used, and the fluorescent lamp was illuminated from the first light-transmitting optical film side through the irradiation-side linear polarizer. On the viewing side, a viewing-side linear polarizer was placed so as to be orthogonal (crossed Nicols) to the irradiation-side linear polarizer, and observation was made from the first light-transmitting optical film side through the viewing-side linear polarizer. Observation was made under conditions that suppressed surface reflection of the first light-transmitting optical film using the irradiation-side linear polarizer and the viewing-side linear polarizer. The evaluation was based on the following criteria. ⊚: No reflection unevenness was visible in either evaluation 1 or evaluation 2. ◯: Weak reflection unevenness was visible in evaluation 2, but no reflection unevenness was visible in evaluation 1. Δ: Reflection unevenness was visible in evaluation 2, but not in evaluation 1. ×: Evaluation 2: Reflection unevenness was visually recognized, and evaluation 1: Weak reflection unevenness was visually recognized. XX: Reflection unevenness was visible in evaluation 2, and reflection unevenness was visible in evaluation 1.

[0112] <Evaluation of Adhesion> A 15 mm wide rectangular sample (when the second translucent optical film was a λ / 4 plate retardation film, a sample cut to a width of 15 mm along the slow axis) was prepared from the optical laminate obtained in each of the Examples and Comparative Examples. The first translucent optical film was fixed to a glass plate with adhesive tape (manufactured by Nitto Denko Corporation, product name "No. 5000NS", thickness: 160 μm). The second translucent optical film was backed with polyimide tape (manufactured by Nitto Denko Corporation, product name "No. 360A", thickness: 25 μm) using a hand roller. Peeling of the polyimide tape-backed second translucent optical film was attempted at a peel angle of 90° and a peel rate of 20,000 mm / min under an environment of a temperature of 23°C and a humidity of 50% RH. The evaluation was based on the following criteria. ◯: Peeling force was 1.5 N / 15 mm or more, or peeling was not possible. △: The peeling force was 0.3 N / 15 mm or more and less than 1.5 N / 15 mm. ×: The peeling force was less than 0.3 N / 15 mm.

[0113] <Evaluation of smoothness> The smoothness of the laminate was measured using a phase-shifting laser interferometer (manufactured by Zygo, product name "DynaFiz") Specifically, the sample was attached to a microslide glass (manufactured by Matsunami Glass Industry Co., Ltd., product name "S200200") with a 5 μm-thick acrylic adhesive layer with minimal unevenness to obtain a measurement sample. The 5 μm thick acrylic pressure-sensitive adhesive layer with minimal irregularities was the pressure-sensitive adhesive layer obtained in the production of the pressure-sensitive adhesive tape used in the above-mentioned evaluation 1 of reflection unevenness. The sample to be measured was placed on a vibration-isolating measurement table, and a single-wavelength (633 nm) laser was used to interfere with a standard with guaranteed flatness, measuring the relative displacement within a specified area (a circle of 30 mm diameter). For analysis, the "Slope Magnitude RMS" angle index obtained by extracting frequency values ​​from 0.1 / mm to 1 / mm was doubled (equivalent to 2σ) to define the laminate smoothness (unit: arcmin). The adhesive used here was 0.25 arcmin or less. The evaluation was based on the following criteria. ◯: The smoothness of the laminate was 0.4 arcmin or less. ×: The smoothness of the laminate exceeded 0.4 arcmin.

[0114] [Production Example 1] Production of photopolymerizable liquid crystal composition A photopolymerizable liquid crystal compound exhibiting a nematic liquid crystal phase (BASF's "Paliocolor LC242") was dissolved in cyclopentanone to prepare a solution with a solids concentration of 30 wt%. A surfactant (BYK-Chemie's "BYK-360") and a photopolymerization initiator (IGM Resins BV's "Omnirad907") were added to this solution to prepare a liquid crystal composition solution. The amounts of surfactant and photopolymerization initiator added were 0.01 and 3 parts by weight, respectively, per 100 parts by weight of the photopolymerizable liquid crystal compound.

[0115] [Production Example 2] Production of Retardation Film 1 (λ / 2 Retardation Film) A biaxially stretched norbornene film (manufactured by Zeon Corporation, trade name "ZEONORFILM", thickness = 33 μm, front retardation = 135 nm) was used as a substrate. The liquid crystal composition solution prepared in Production Example 1 was applied to this substrate using a bar coater so that the phase difference was λ / 2, and the liquid crystal was aligned by heating at 100°C for 3 minutes. After cooling to room temperature, the film was irradiated with an integrated light dose of 400 mJ / cm under a nitrogen atmosphere. 2 The film was photocured by irradiating it with ultraviolet light, to obtain a laminate (1) having a structure of substrate / retardation film 1 (first liquid crystal alignment solidified layer). The first liquid crystal alignment solidified layer was homogeneously aligned and had a thickness of 2 μm.

[0116] [Production Example 3] Production of Retardation Film 2 (λ / 4 Retardation Film) A biaxially stretched norbornene film (manufactured by Zeon Corporation, trade name "ZEONORFILM", thickness = 33 μm, front retardation = 135 nm) was used as a substrate, and the liquid crystal composition solution prepared in Production Example 1 was applied to this substrate using a bar coater so that the phase difference was λ / 4, and the liquid crystal was aligned by heating at 100°C for 3 minutes. After cooling to room temperature, the film was irradiated with an accumulated light dose of 400 mJ / cm under a nitrogen atmosphere. 2The film was photocured by irradiating it with ultraviolet light, to obtain a laminate (2) having a structure of substrate / retardation film 2 (second liquid crystal alignment solidified layer). The second liquid crystal alignment solidified layer was homogeneously aligned and had a thickness of 1 μm.

[0117] [Production Example 4] Preparation of an olefin-based film as a light-transmitting optical film An olefin film (manufactured by Nippon Zeon Co., Ltd., trade name "Zeonorfilm") having a thickness of 3 μm was used.

[0118] [Manufacturing Example 5] Preparation of PET film as a light-transmitting optical film A 38 μm thick polyethylene terephthalate (PET) film (manufactured by Toray Industries, Inc., trade name "Lumirror") was used.

[0119] [Manufacturing Example 6] Preparation of acrylic film as a light-transmitting optical film A 20 μm thick polymethyl methacrylate (PMMA) film (manufactured by Mitsubishi Chemical Corporation, trade name "Acryplene") was used.

[0120] [Production Example 7] Preparation of adhesive solution (1) An aqueous solution was prepared by mixing an amino silane coupling agent (N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM-603") and an epoxy silane coupling agent (3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM-403") in a weight ratio of 1:1, with the total concentration of these (total concentration of the amino compound and the epoxy compound) being 1.0 wt%. To 100 parts by weight of the obtained aqueous solution, 0.2 parts by weight of a surfactant (manufactured by Nissin Chemical Industry Co., Ltd., trade name "EXP4200") was added to prepare an adhesive solution (1).

[0121] [Production Example 8] Preparation of adhesive solution (2) An adhesive solution (2) was prepared in the same manner as in Production Example 7, except that the total concentration of the amino compound and the epoxy compound was adjusted to 2.5 wt % in the aqueous solution.

[0122] [Production Example 9] Preparation of adhesive solution (3) An adhesive solution (3) was prepared in the same manner as in Production Example 7, except that the total concentration of the amino compound and the epoxy compound was adjusted to 3.0 wt % in the aqueous solution.

[0123] [Production Example 10] Preparation of adhesive solution (4) An adhesive solution (4) was prepared in the same manner as in Production Example 7, except that the total concentration of the amino compound and the epoxy compound was adjusted to 5.0 wt % in the aqueous solution.

[0124] [Production Example 11] Preparation of adhesive solution (5) An adhesive solution (5) was prepared in the same manner as in Production Example 7, except that the total concentration of the amino compound and the epoxy compound was adjusted to 0.2 wt % in the aqueous solution.

[0125] [Production Example 12] Preparation of adhesive solution (6) An adhesive solution (6) was prepared in the same manner as in Production Example 7, except that the total concentration of the amino compound and the epoxy compound was adjusted to 7.0 wt % in the aqueous solution.

[0126] [Production Example 13] Preparation of adhesive solution (7) An adhesive solution (7) was prepared in the same manner as in Production Example 7, except that the total concentration of the amino compound and the epoxy compound was adjusted to 6.0 wt % in the aqueous solution.

[0127] [Production Example 14] Preparation of adhesive solution (8) An aqueous solution of N,N'-bis(2-aminoethyl)-6-(3-trihydroxysilylpropyl)amino-1,3,5-triazine-2,4-diamine (manufactured by Io Chemical Research Institute) as an amino compound was prepared to a concentration of 1.0 wt %. To 100 parts by weight of the obtained aqueous solution, 0.2 parts by weight of a surfactant (manufactured by Nissin Chemical Industry Co., Ltd., trade name "EXP4200") was added to prepare an adhesive solution (8).

[0128] [Production Example 15] Preparation of adhesive solution (9) An aqueous solution was prepared by mixing N,N'-bis(2-aminoethyl)-6-(3-trihydroxysilylpropyl)amino-1,3,5-triazine-2,4-diamine (manufactured by Io Chemical Research Institute) as an amino compound, an amino silane coupling agent (N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM-603"), and an epoxy silane coupling agent (3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM-403") in a weight ratio of 4:1:1, with the total concentration (total concentration of the amino compound and the epoxy compound) being 1.0 wt%. To 100 parts by weight of the obtained aqueous solution, 0.2 parts by weight of a surfactant (manufactured by Nissin Chemical Industry Co., Ltd., trade name "EXP4200") was added to prepare an adhesive solution (9).

[0129] [Production Example 16] Preparation of adhesive solution (10) An aqueous solution was prepared by mixing N,N'-bis(2-aminoethyl)-6-(3-trihydroxysilylpropyl)amino-1,3,5-triazine-2,4-diamine (manufactured by Io Chemical Research Institute) as an amino compound, an amino silane coupling agent (N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM-603"), and an epoxy silane coupling agent (3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., product name "KBM-403") in a weight ratio of 1:1:1, with the total concentration of these (total concentration of the amino compound and the epoxy compound) being 1.0 wt%. To 100 parts by weight of the obtained aqueous solution, 0.2 parts by weight of a surfactant (manufactured by Nissin Chemical Industry Co., Ltd., trade name "EXP4200") was added to prepare an adhesive solution (10).

[0130] [Production Example 17] Preparation of adhesive solution (11) 20 parts by weight of N-acryloylmorpholine (manufactured by KJ Chemicals), 10 parts by weight of Plaxel FA1DDM (manufactured by Daicel Corporation), 60 parts by weight of OGSOLEA-F5710 (manufactured by Osaka Gas Chemicals Co., Ltd.), 5 parts by weight of ARUFON UP-1190 (manufactured by Toagosei Co., Ltd.), 3 parts by weight of Omnirad907 (manufactured by IGM Resins BV), and 3 parts by weight of KAYACURE DETX-S (manufactured by Nippon Kayaku Co., Ltd.) were mixed and diluted with ethyl acetate to a concentration of 3.0% by weight to prepare an adhesive solution (11).

[0131] [Production Example 18] Preparation of adhesive solution (12) An adhesive solution (12) was prepared in the same manner as in Production Example 17, except that the solution was not diluted with ethyl acetate.

[0132] [Production Example 19] Preparation of adhesive solution (13) An adhesive solution (13) was prepared by mixing 20 parts by weight of N-acryloylmorpholine (manufactured by KJ Chemicals), 50 parts by weight of Plaxel FA1DDM (manufactured by Daicel Corporation), 10 parts by weight of Light Acrylate 1,9ND-A (manufactured by Kyoeisha Chemical Co., Ltd.), 15 parts by weight of ARUFON UP-1190 (manufactured by Toagosei Co., Ltd.), 3 parts by weight of Omnirad907 (manufactured by IGM Resins BV), and 3 parts by weight of KAYACURE DETX-S (manufactured by Nippon Kayaku Co., Ltd.).

[0133] [Production Example 20] Preparation of adhesive solution (14) An adhesive solution (14) was prepared by mixing 6.02 parts by weight of acetoacetyl-modified PVA (degree of polymerization 1200, degree of acetoacetyl modification 4.6%, degree of saponification 99.0 mol% or more, solids concentration 4%, manufactured by Mitsubishi Chemical Corporation, product name "Gohsenex Z-200"), 25 parts by weight of an aqueous solution containing positively charged alumina colloid (average particle diameter 15 nm) at a solids concentration of 3.2%, and 18.98 parts by weight of pure water.

[0134] [Example 1] The first liquid crystal alignment solidified layer side of the laminate (1) obtained in Production Example 2 and the second liquid crystal alignment solidified layer side of the laminate (2) obtained in Production Example 3 were treated with a corona treatment machine at a treatment density of 50 W·min / m 2Corona treatment was carried out. Using an MCD coater (manufactured by Fuji Machinery Co., Ltd.) (cell shape: honeycomb, gravure roll ruling: 1000 rolls / inch, rotation speed 130% / line speed), the adhesive solution (1) obtained in Production Example 7 was coated to a coating thickness of 1 μm on the corona-irradiated surface of the laminate (1), and the laminate (2) was laminated using a laminating roll machine so that the corona-irradiated surface of the laminate (2) faced the coated surface. The lamination line speed was 15 m / min. The lamination was performed so that the slow axis of retardation film 2 (λ / 4 retardation film) was at a 60° angle with the slow axis of retardation film 1 (λ / 2 retardation film). After lamination, the laminate was heated and dried at 60°C for 10 minutes to form an adhesive layer (1) from the adhesive solution (1), and the biaxially stretched norbornene-based films on both sides were peeled off from the resulting laminate to obtain an optical laminate (1) having a configuration of retardation film 1 / adhesive layer (1) / retardation film 2. The results are shown in Table 1.

[0135] [Example 2] The same procedure as in Example 1 was carried out except that the adhesive solution (2) obtained in Production Example 8 was used instead of the adhesive solution (1) obtained in Production Example 7, and an optical laminate (2) having a configuration of retardation film 1 / adhesive layer (2) / retardation film 2 was obtained. The results are shown in Table 1.

[0136] [Example 3] The same procedure as in Example 1 was carried out except that the adhesive solution (3) obtained in Production Example 9 was used instead of the adhesive solution (1) obtained in Production Example 7, and an optical laminate (3) having a configuration of retardation film 1 / adhesive layer (3) / retardation film 2 was obtained. The results are shown in Table 1.

[0137] [Example 4] The same procedure as in Example 1 was carried out except that the adhesive solution (4) obtained in Production Example 10 was used instead of the adhesive solution (1) obtained in Production Example 7, and an optical laminate (4) having a configuration of retardation film 1 / adhesive layer (4) / retardation film 2 was obtained. The results are shown in Table 1.

[0138] [Example 5] The same procedure as in Example 1 was carried out except that the adhesive solution (5) obtained in Production Example 11 was used instead of the adhesive solution (1) obtained in Production Example 7, and an optical laminate (5) having a configuration of retardation film 1 / adhesive layer (5) / retardation film 2 was obtained. The results are shown in Table 1.

[0139] [Example 6] One side of the olefin-based film prepared in Production Example 4 was treated with a corona treatment machine at a treatment density of 50 W·min / m 2 Two sheets of this were prepared. Using an MCD coater (manufactured by Fuji Machinery Co., Ltd.) (cell shape: honeycomb, gravure roll line count: 1000 rolls / inch, rotation speed 130% / line speed), the adhesive solution (1) obtained in Production Example 7 was coated to a coating thickness of 1 μm on the corona-irradiated surface of one of the above olefin-based films, and then the other olefin-based film was laminated using a laminating roll machine so that the corona-irradiated surface faced the coated surface. The lamination line speed was 15 m / min. After lamination, the films were heated and dried at 60°C for 10 minutes to form an adhesive layer (1) from the adhesive solution (1), thereby obtaining an optical laminate (6) having a structure of olefin-based film / adhesive layer (1) / olefin-based film. The results are shown in Table 1.

[0140] [Example 7] The same procedure as in Example 6 was carried out, except that the PET film prepared in Production Example 5 was used instead of the olefin-based film prepared in Production Example 4, to obtain an optical laminate (7) having a structure of PET film / adhesive layer (1) / PET film. The results are shown in Table 1.

[0141] [Example 8] The same procedure as in Example 6 was carried out, except that the acrylic film prepared in Production Example 6 was used instead of the olefin-based film prepared in Production Example 4, to obtain an optical laminate (8) having a structure of acrylic film / adhesive layer (1) / acrylic film. The results are shown in Table 1.

[0142] [Example 9] The same procedure as in Example 1 was carried out except that the adhesive solution (8) obtained in Production Example 14 was used instead of the adhesive solution (1) obtained in Production Example 7, and an optical laminate (9) having a configuration of retardation film 1 / adhesive layer (8) / retardation film 2 was obtained. The results are shown in Table 1.

[0143] [Example 10] The same procedure as in Example 1 was carried out except that the adhesive solution (9) obtained in Production Example 15 was used instead of the adhesive solution (1) obtained in Production Example 7, and an optical laminate (10) having a configuration of retardation film 1 / adhesive layer (9) / retardation film 2 was obtained. The results are shown in Table 1.

[0144] [Example 11] The same procedure as in Example 1 was carried out except that the adhesive solution (10) obtained in Production Example 16 was used instead of the adhesive solution (1) obtained in Production Example 7, and an optical laminate (11) having a configuration of retardation film 1 / adhesive layer (10) / retardation film 2 was obtained. The results are shown in Table 1.

[0145] [Example 12] One side of the acrylic film prepared in Production Example 6 was treated with a corona treatment machine at a treatment density of 50 W·min / m 2 Corona treatment was carried out. The second liquid crystal alignment solidified layer side of the laminate (2) obtained in Production Example 3 was treated with a corona treatment machine at a treatment density of 50 W·min / m 2 Corona treatment was carried out. Using an MCD coater (manufactured by Fuji Machinery Co., Ltd.) (cell shape: honeycomb, gravure roll line count: 1000 / inch, rotation speed 130% / line speed), the adhesive solution (1) obtained in Production Example 7 was coated to a coating thickness of 1 μm on the corona-irradiated surface of the acrylic film, and the laminate (2) was laminated using a laminating roll machine so that the corona-irradiated surface faced the coated surface. The lamination line speed was 15 m / min. After lamination, the laminate was heated and dried at 60°C for 10 minutes to form an adhesive layer (1) from the adhesive solution (1), and the biaxially stretched norbornene-based film on one side of the resulting laminate was peeled off to obtain an optical laminate (12) having a configuration of acrylic film / adhesive layer (1) / retardation film 2. The results are shown in Table 1.

[0146] [Example 13] The adhesive solution (11) obtained in Production Example 17 was used instead of the adhesive solution (1) obtained in Production Example 7. The retardation film 1 and the retardation film 2 were laminated together, and then, instead of being dried by heating at 60°C for 10 minutes, a visible light irradiation device (manufactured by Excelitas, Light HAMMER10 Mark III, bulb: V bulb, peak irradiance: 1600 mW / cm) was used from the side of the retardation film 2. 2 , cumulative irradiation dose 1000 / mJ / cm 2 The same procedure as in Example 1 was carried out except that the adhesive layer (11) was formed from the adhesive solution (11) by irradiating the adhesive solution (11) with active energy rays using a condenser (10) to obtain an optical laminate (13) having a configuration of retardation film 1 / adhesive layer (11) / retardation film 2. The illuminance of visible light was measured using a Sola-Check system manufactured by Solatell. The results are shown in Table 1.

[0147] [Example 14] The same procedure as in Example 1 was carried out except that the adhesive solution (14) obtained in Production Example 20 was used instead of the adhesive solution (1) obtained in Production Example 7, and an optical laminate (14) having a configuration of retardation film 1 / adhesive layer (14) / retardation film 2 was obtained. The results are shown in Table 1.

[0148] [Comparative Example 1] The same procedure as in Example 1 was carried out except that the adhesive solution (6) obtained in Production Example 12 was used instead of the adhesive solution (1) obtained in Production Example 7, and an optical laminate (C1) having a configuration of retardation film 1 / adhesive layer (6) / retardation film 2 was obtained. The results are shown in Table 1.

[0149] Comparative Example 2 The same procedure as in Example 1 was carried out except that the adhesive solution (7) obtained in Production Example 13 was used instead of the adhesive solution (1) obtained in Production Example 7, and an optical laminate (C2) having a configuration of retardation film 1 / adhesive layer (7) / retardation film 2 was obtained. The results are shown in Table 1.

[0150] Comparative Example 3 The adhesive solution (12) obtained in Production Example 18 was used instead of the adhesive solution (1) obtained in Production Example 7. The retardation film 1 and the retardation film 2 were laminated together, and then, instead of being dried by heating at 60°C for 10 minutes, a visible light irradiation device (manufactured by Excelitas, Light HAMMER10 Mark III, bulb: V bulb, peak irradiance: 1600 mW / cm) was used from the side of the retardation film 2. 2 , cumulative irradiation dose 1000 / mJ / cm 2 The same procedure as in Example 1 was carried out except that the adhesive layer (12) was formed from the adhesive solution (12) by irradiating the adhesive solution (12) with active energy rays using a condenser (100) . The optical laminate (C3) having a configuration of retardation film 1 / adhesive layer (12) / retardation film 2 was obtained. The illuminance of visible light was measured using a Sola-Check system manufactured by Solatell. The results are shown in Table 1.

[0151] Comparative Example 4 One side of the olefin-based film prepared in Production Example 4 was treated with a corona treatment machine at a treatment density of 50 W·min / m 2 Two sheets of this were prepared. Using an MCD coater (manufactured by Fuji Machinery Co., Ltd.) (cell shape: honeycomb, gravure roll line count: 1000 rolls / inch, rotation speed 130% / line speed), the adhesive solution (12) obtained in Production Example 18 was coated to a coating thickness of 1 μm on the corona-irradiated surface of the olefin-based film, and the olefin-based film was laminated using a laminating roll machine so that the corona-irradiated surface of the olefin-based film faced the coated surface. The line speed for lamination was 15 m / min. After lamination, one of the olefin-based films was irradiated with visible light using a visible light irradiation device (Excelitas Light HAMMER10 Mark III, bulb: V bulb, peak irradiance: 1600 mW / cm 2 , cumulative irradiation dose 1000 / mJ / cm 2 ) to irradiate the adhesive solution (12) with active energy rays to form an adhesive layer (12), thereby obtaining an optical laminate (C4) having a configuration of olefin-based film / adhesive layer (12) / olefin-based film. The illuminance of visible light was measured using a Sola-Check system manufactured by Solatell. The results are shown in Table 1.

[0152] Comparative Example 5 The same procedure as in Comparative Example 4 was carried out, except that the PET film prepared in Production Example 5 was used instead of the olefin-based film prepared in Production Example 4, and the adhesive solution (13) obtained in Production Example 19 was used instead of the adhesive solution (12) obtained in Production Example 18, to obtain an optical laminate (C5) having a configuration of PET film / adhesive layer (13) / PET film. The results are shown in Table 1.

[0153] Comparative Example 6 The same procedure as in Comparative Example 4 was carried out except that the acrylic film prepared in Production Example 6 was used instead of the olefin-based film prepared in Production Example 4, and an optical laminate (C6) having a structure of acrylic film / adhesive layer (12) / acrylic film was obtained. The results are shown in Table 1.

[0154] Comparative Example 7 One side of the acrylic film prepared in Production Example 6 was treated with a corona treatment machine at a treatment density of 50 W·min / m 2 Corona treatment was carried out. The second liquid crystal alignment solidified layer side of the laminate (2) obtained in Production Example 3 was treated with a corona treatment machine at a treatment density of 50 W·min / m 2 Corona treatment was carried out. Using an MCD coater (manufactured by Fuji Machinery Co., Ltd.) (cell shape: honeycomb, gravure roll ruling: 1000 rolls / inch, rotation speed 130% / line speed), the adhesive solution (12) obtained in Production Example 18 was coated to a coating thickness of 1 μm on the corona-irradiated surface of the acrylic film, and the laminate (2) was laminated using a laminating roll machine so that the corona-irradiated surface faced the coated surface. The line speed for lamination was 15 m / min. After lamination, the laminate was heated and dried at 60°C for 10 minutes to form an adhesive layer (12) from the adhesive solution (12), and the biaxially stretched norbornene-based film on one side was peeled off from the resulting laminate to obtain an optical laminate (C7) having a configuration of acrylic film / adhesive layer (12) / retardation film 2. The results are shown in Table 1.

[0155] [Table 1] [Industrial Applicability]

[0156] The optical laminate according to the embodiment of the present invention can be used for any appropriate purpose, and can be suitably used for, for example, image display devices such as liquid crystal display devices and organic EL display devices. [Explanation of symbols]

[0157] 1000 Optical Components 100 Optical laminate 10 First light-transmitting optical film 20 Second light-transmitting optical film 30 Adhesive layer 40 Polarizing Film 50 adhesive layer 60 Panel side adhesive layer

Claims

1. An optical laminate in which a first light-transmitting optical film and a second light-transmitting optical film are bonded together with an adhesive layer, The thickness of the adhesive layer is 50 nm or less. Optical laminate.

2. The optical laminate according to claim 1 , wherein the adhesive layer has a thickness of less than 30 nm.

3. The optical laminate according to claim 1 , wherein the difference in in-plane refractive index between the first light-transmitting optical film and the adhesive layer is 0.05 or more.

4. The optical laminate according to claim 1 , wherein the first light-transmitting optical film has an in-plane refractive index of 1.50 or more.

5. The optical laminate according to claim 1 , wherein the difference in in-plane refractive index between the second light-transmitting optical film and the adhesive layer is 0.05 or more.

6. The optical laminate according to claim 1 , wherein the second light-transmitting optical film has an in-plane refractive index of 1.50 or more.

7. The optical laminate according to claim 1 , wherein at least one of the first light-transmitting optical film and the second light-transmitting optical film is a retardation film.

8. The optical laminate according to claim 1 , wherein the adhesive layer is formed from a water-based adhesive solution containing at least one amino compound.

9. The optical laminate according to claim 8 , wherein the adhesive layer is formed from a water-based adhesive solution containing at least one amino compound and an epoxy compound.

10. The optical laminate according to claim 1 , wherein the adhesive layer comprises an organosilicon compound.

11. An image display device comprising the optical laminate according to any one of claims 1 to 10.

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