Method for manufacturing optical laminates and optical components

Abstract

To provide an optical laminate in which the optical component is less likely to break when integrated with a component having a curved surface. [Solution] An optical laminate according to an embodiment of the present invention includes a first phase difference film having a first main surface and a second main surface, and is an optical laminate for integration with a member having a curved surface, wherein the first phase difference film is a laminate of an orientation solidification layer of a liquid crystal compound and an orientation film arranged in this order from the first main surface side, and when the elastic moduli of the first main surface and the second main surface of the first phase difference film measured by a nanoindenter are X1 and X2, respectively, X1 and X2 satisfy the relationship 0.58 ≤ X1 / X2 ≤ 1.65.

Description

Technical Field

[0001] The present invention relates to an optical laminate and a method for manufacturing an optical member.

Background Art

[0002] Image display devices typified by liquid crystal display devices and electroluminescence (EL) display devices (e.g., organic EL display devices) have been rapidly spreading. In image display devices, in order to realize image display and improve the performance of image display, generally, optical members such as retardation members and polarizing members are used (see, for example, Patent Document 1). These optical members can be pre-integrated and mounted on an image display device as an optical laminate.

[0003] In recent years, new applications of image display devices have been developed. For example, goggles with a display (VR goggles) for realizing Virtual Reality (VR) have begun to be commercialized. Since VR goggles are being considered for use in various scenarios, weight reduction, improvement of visibility, etc. are desired.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The weight reduction of the VR goggles described above can be achieved, for example, by thinning the lenses used in the VR goggles. On the other hand, the development of an optical laminate including the above optical members suitable for a display system using lenses is also desired. For example, the development of an optical laminate that can be suitably integrated with a lens having a curved surface is desired.

[0006] In view of the above, the main objective of the present invention is to provide an optical laminate that is less prone to fracture of the optical component when integrated with a member having a curved surface (for example, a lens). [Means for solving the problem]

[0007] [1] According to one aspect of the present invention, an optical laminate is provided which includes a first phase difference film having a first main surface and a second main surface, and is to be integrated into a member having a curved surface, wherein the first phase difference film is a laminate of an orientation solidified layer of a liquid crystal compound and an orientation film arranged in this order from the first main surface side, and when the elastic moduli of the first main surface and the second main surface of the first phase difference film measured by a nanoindenter are X1 and X2, respectively, X1 and X2 satisfy the relationship 0.58 ≤ X1 / X2 ≤ 1.65. [2] In the optical laminate described in [1] above, when the elastic recovery rates of the first main surface and the second main surface of the first phase difference film measured by a nanoindenter are Y1 and Y2, respectively, Y1 and Y2 may satisfy the relationship 0.80 ≤ Y1 / Y2 ≤ 1.10. [3] In the optical laminate described in [1] or [2] above, when the hardness of the first main surface and the second main surface of the first phase difference film measured by a nanoindenter are denoted as Z1 and Z2, respectively, Z1 and Z2 may satisfy the relationship 0.80 ≤ Z1 / Z2 ≤ 1.20. [4] The optical laminate described in any of [1] to [3] above may further include a second phase difference film composed of an orientation solidification layer of a liquid crystal compound. [5] In the optical laminate described in [4] above, the first phase difference film and the second phase difference film may be laminated with an adhesive layer in between, and the thickness of the adhesive layer may be 0.5 μm or more and 2 μm or less. [6] The optical laminate described in [4] or [5] above may further include an adhesive layer, and the adhesive layer, the first phase difference film, and the second phase difference film may be arranged in this order. [7] In the optical laminate described in any of [1] to [6] above, the radius of curvature of the curved portion of the member having the curved portion may be 20 mm or more and 150 mm or less. [8] The optical laminate described in any of [1] to [7] above may have an elastic modulus X1 of the first main surface of the first phase difference film of 1.0 GPa or more. [9] The optical laminate described in any of [1] to [8] above is used in a display system comprising: a display element having a display surface that emits light representing an image forward via a polarizing member; a reflective polarizing member disposed in front of the display element and reflecting light emitted from the display element; a first lens portion having a curved surface and disposed in the optical path between the display element and the reflective polarizing member; a half mirror disposed between the display element and the first lens portion, which transmits light emitted from the display element and reflects the light reflected by the reflective polarizing member toward the reflective polarizing member; a first λ / 4 member disposed in the optical path between the display element and the half mirror; and a second λ / 4 member disposed in the optical path between the half mirror and the reflective polarizing member, and may be integrated with the first lens portion.

[10] According to another aspect of the present invention, a method for manufacturing an optical member is provided, which includes integrating the optical laminate described in any of [1] to [9] above onto the curved portion of a member having a curved portion under heating conditions. [Effects of the Invention]

[0008] According to embodiments of the present invention, in an optical laminate using a phase difference film containing an orientation solidified layer of a liquid crystal compound, the breakage of the phase difference film when it is integrated into a member having a curved surface can be suppressed by adjusting the ratio of the elastic moduli of both main surfaces of the phase difference film containing the orientation solidified layer of a liquid crystal compound. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic cross-sectional view showing the general configuration of an optical laminate according to one embodiment of the present invention. [Figure 2]This is a schematic cross-sectional view showing the general configuration of an optical laminate according to one embodiment of the present invention. [Figure 3] This is a schematic cross-sectional view showing the general configuration of an optical laminate according to one embodiment of the present invention. [Figure 4] This is a schematic diagram illustrating an example of a method for integrating an optical laminate with a member having a curved surface. [Figure 5] This is a schematic cross-sectional view illustrating an example of a method for producing a phase difference film containing a liquid crystal alignment solidification layer. [Figure 6] This is a schematic cross-sectional view showing the general configuration of an optical laminate according to one embodiment of the present invention. [Figure 7] This is a schematic cross-sectional view showing the general configuration of an optical laminate according to one embodiment of the present invention. [Figure 8] This is a schematic diagram showing the general configuration of a display system to which an optical laminate according to an embodiment of the present invention may be applied. [Figure 9] Figure 8 is a schematic cross-sectional view showing an example of a configuration in which a component positioned between the first lens section and the second lens section of the display system is integrated with the first lens section. [Figure 10] Figure 8 is a schematic cross-sectional view showing an example of a configuration in which a component positioned between the first lens section and the second lens section of the display system is integrated with the first lens section. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments. While the drawings may schematically represent the width, thickness, shape, etc., of each part compared to the embodiments in order to clarify the explanation, these are merely examples and do not limit the interpretation of the present invention. Furthermore, in the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant explanations may be omitted.

[0011] (Definitions of terms and symbols) 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 where the in-plane refractive index is maximum (i.e., the slow axis direction), “ny” is the refractive index in the direction orthogonal to the slow axis in the plane (i.e., the fast axis direction), and “nz” is the refractive index in the thickness direction. (2) In-plane retardation (Re) “Re(λ)” is the in-plane retardation measured with light of wavelength λ nm at 23°C. For example, “Re(550)” is the in-plane retardation measured with light of wavelength 550 nm at 23°C. Re(λ) is obtained by the formula: Re(λ) = (nx - ny) × d, where d (nm) is the thickness of the layer (film). (3) Retardation in the thickness direction (Rth) “Rth(λ)” is the retardation in the thickness direction measured with light of wavelength λ nm at 23°C. For example, “Rth(550)” is the retardation in the thickness direction measured with light of wavelength 550 nm at 23°C. Rth(λ) is obtained by the formula: Rth(λ) = (nx - nz) × d, where d (nm) is the thickness of the layer (film). (4) Nz coefficient The Nz coefficient is obtained by Nz = Rth / Re. (5) Angle When referring to an angle in this specification, unless otherwise specified, the angle includes both clockwise and counterclockwise directions with respect to the reference direction. Thus, for example, “45°” means ±45°. Also, in this specification, “substantially parallel” includes the range of 0° ± 10°, preferably within the range of 0° ± 5°, more preferably within the range of 0° ± 3°, and even more preferably within the range of 0° ± 1°. “Substantially orthogonal” includes the range of 90° ± 10°, preferably within the range of 90° ± 5°, more preferably within the range of 90° ± 3°, and even more preferably within the range of 90° ± 1°.

[0012] A. Optical laminate According to an embodiment of the present invention, an optical laminate is provided which includes a first phase difference film having a first main surface and a second main surface, wherein the first phase difference film is a laminate of an alignment solidification layer of a liquid crystal compound (hereinafter sometimes referred to as the "liquid crystal alignment solidification layer") and an alignment film, arranged in this order from the first main surface side, and when the elastic moduli of the first main surface and the second main surface of the first phase difference film measured by a nanoindenter are denoted as X1 and X2, respectively, X1 and X2 satisfy the relationship 0.58 ≤ X1 / X2 ≤ 1.65.

[0013] Figures 1 to 3 are schematic cross-sectional views showing the general configuration of an optical laminate according to one embodiment of the present invention.

[0014] The optical laminate 100A shown in Figure 1 includes a first phase difference film 110 having a first main surface 110a and a second main surface 110b. The first phase difference film 110 is a laminate of a liquid crystal alignment solidification layer 112 and an alignment film 114 arranged in this order from the first main surface 110a side. The optical laminate 100A further includes an adhesive layer 120 arranged on the second main surface 110b side (alignment film 114 side) of the first phase difference film 110.

[0015] The optical laminate 100B shown in Figure 2 differs from the optical laminate 100A in that it further includes a second phase difference film 130 positioned on the first main surface 110a side (liquid crystal alignment solidification layer 112 side) of the first phase difference film 110. The first phase difference film 110 and the second phase difference film 130 are laminated with an adhesive layer 140 in between. The second phase difference film 130 has a first main surface 130a and a second main surface 130b and is composed of a liquid crystal alignment solidification layer 132.

[0016] The optical laminate 100C shown in Figure 3 differs from the optical laminate 100A in that it further includes another first phase difference film 110 positioned on the first main surface 110a side (liquid crystal alignment solidification layer 112 side) of the first phase difference film 110. The two first phase difference films 110 are laminated via an adhesive layer 140 such that the liquid crystal alignment solidification layers 112 face each other.

[0017] In optical laminates 100A to C, the orientation of the first main surface 110a and the second main surface 110b of the first phase difference film 110, and the orientation of the first main surface 130a and the second main surface 130b of the second phase difference film 130 are not limited. Specifically, in optical laminates 100A to C, the first phase difference film 110 and the second phase difference film 130 may be arranged such that the first main surfaces 110a, 130a and the second main surfaces 110b, 130b are on opposite sides, respectively. In practice, the orientation of the first and second main surfaces can be determined considering the handling of each phase difference film. Until the optical laminates 100A to C are put into use, a release liner may be temporarily attached to the surface of the adhesive layer 120. The adhesive layer 120 is typically provided as the outermost layer of the optical laminate and may be used to bond the optical laminate to adjacent members and integrate them.

[0018] The configuration of the optical laminate according to the embodiments of the present invention is not limited to the illustrated example above. For example, the optical laminate may include three or more first phase difference films. When the optical laminate includes two or more first phase difference films, each first phase difference film may have different configurations (forming material, thickness, etc.) and / or optical properties (in-plane phase difference, refractive index characteristics, etc.) as long as the relationship 0.58 ≤ X1 / X2 ≤ 1.65 is satisfied. Furthermore, the optical laminate may further include other optical members as long as the effects of the present invention are obtained. Examples of such optical members include reflective polarizing members, absorptive polarizing members, protective members, and phase difference members composed of resin films. These other optical members may be laminated, for example, via an adhesive layer. The optical laminate of this embodiment is a laminate of liquid crystal alignment solidification layers and alignment films arranged in this order from the first main surface side, and it is preferable that it does not contain a phase difference film such that the elastic modulus X1 of the liquid crystal alignment solidification layer surface (first main surface) and the elastic modulus X2 of the alignment film surface (second main surface), as measured by a nanoindenter, satisfy the relationship X1 / X2 < 0.58 or X1 / X2 > 1.65.

[0019] The total thickness of the optical laminate described above (excluding the outermost adhesive layer 120) may be, for example, 5 μm to 1000 μm, preferably 10 μm to 500 μm.

[0020] The optical laminate described above is typically used integrated with a member having a curved surface (for example, a lens member). Figure 4 is a schematic diagram illustrating an example of a process for integrating an optical laminate with a member having a curved surface. In Figure 4(a), the optical laminate 100, which has an adhesive layer as its outermost layer, is placed on member L such that the adhesive layer faces the member L that is the adherend. Member L is, for example, circular in plan view and has a concave shape on the top in cross-section. The optical laminate 100 can be positioned in a predetermined location by chucking its end with a fixing jig (not shown). The optical laminate 100 is positioned so that the adhesive layer is in contact with the edge of the concave surface of member L, and when softened by heating, it is pressed into the concave side of member L, thereby bonding it across the entire concave surface of member L, as shown in Figure 4(b). Subsequently, as shown in Figure 4(c), an integrated product can be obtained by removing unnecessary parts of the optical laminate 100 (for example, parts that protrude from member L in plan view).

[0021] As described above, when the optical laminate 100 is integrated with a member L having a curved portion, it can be stretched from a planar shape (e.g., circular shape) corresponding to the planar shape of member L to a curved shape that follows the curved shape of member L. In this way, tension can be applied to the optical laminate during integration with the curved portion. When the elastic moduli of the first main surface and the second main surface of the first phase difference film, measured by a nanoindenter, are denoted as X1 and X2, respectively, the relationship 0.58 ≤ X1 / X2 ≤ 1.65 can be satisfied by suppressing the fracture of the first phase difference film caused by the application of tension.

[0022] The radius of curvature of the curved portion of the member having the curved portion described above may be, for example, 20 mm or more, 25 mm or more, 30 mm or more, 150 mm or less, preferably 125 mm or less, more preferably 110 mm or less, and may also be 90 mm or less. The diameter (major axis) of the member having the curved portion may be, for example, 20 mm to 80 mm, or 30 mm to 70 mm. The effects of the present invention can be suitably obtained when integrating with a member having a curved portion with the above radius of curvature.

[0023] [Phase difference film] The first phase difference film and the second phase difference film each contain a liquid crystal alignment solidification layer. The liquid crystal alignment solidification layer is a layer in which liquid crystal compounds are aligned in a predetermined direction within the layer, and this alignment state is fixed. Note that the term "alignment solidification layer" is a concept that includes the alignment hardened layer obtained by curing liquid crystal monomers, as described later.

[0024] As shown in Figure 5, the liquid crystal alignment solidification layer 52 can be formed by providing an alignment film 56 on the surface of any suitable substrate 54, applying a coating liquid containing a liquid crystal compound to the surface of the alignment film 56 to orient the liquid crystal compound in a desired direction, and fixing the orientation ((a) and (b)). The liquid crystal alignment solidification layer 52 formed in this way is typically used in a state where it is bonded to another member 58 (c), at which time the substrate 54 can be peeled off. In this case, there are cases where only the substrate 54 is peeled off and the alignment film 56 remains on the surface of the liquid crystal alignment solidification layer 52 (d), and cases where the alignment film 56 is peeled off together with the substrate 54 (e). Alternatively, for example, the liquid crystal alignment solidification layer can be formed without forming an alignment film on the substrate, by using a stretched resin film or a resin film with an alignment agent adsorbed on it as the substrate, applying a coating liquid containing a liquid crystal compound to the surface of the substrate to orient the liquid crystal compound in a desired direction, and fixing the orientation. In such cases as well, the liquid crystal alignment solidification layer can be used in a state where the substrate has been peeled off.

[0025] In the fabrication of the liquid crystal alignment solidification layer as described above, the first phase difference film can be obtained when the liquid crystal alignment solidification layer is formed using an alignment film and the alignment film remains after peeling off the substrate (Figure 5(d)). The second phase difference film can be obtained when the liquid crystal alignment solidification layer is formed using an alignment film and the alignment film is peeled off together with the substrate (Figure 5(e)), or when the liquid crystal alignment solidification layer is formed without using an alignment film. Whether the alignment film peels off together with the substrate or remains can be determined by the adhesion between the substrate and the alignment film, the adhesion between the alignment film and the liquid crystal alignment solidification layer, etc. In this specification, the first main surface of the phase difference film including the liquid crystal alignment solidification layer corresponds to the surface opposite to the substrate side (Air surface) when fabricating the liquid crystal alignment solidification layer on the substrate, and the second main surface corresponds to the surface on the substrate side (substrate surface). Therefore, typically, the first main surface of the first phase difference film is the liquid crystal alignment solidification layer surface, and the second main surface is the alignment film surface. Both the first and second main surfaces of the second phase difference film are liquid crystal alignment solidification layer surfaces, but the second main surface is the surface (substrate surface) that was located closer to the substrate than the first main surface during the fabrication of the liquid crystal alignment solidification layer.

[0026] The alignment film described above has an orientation-regulating force that aligns the liquid crystal compound in a desired direction. Depending on the material used to form the alignment film and the orientation processing conditions, various orientations such as horizontal orientation (homogenous orientation), vertical orientation (homeotropic orientation), hybrid orientation, and tilted orientation can be controlled.

[0027] Examples of horizontal alignment films that exhibit orientation-regulating force in the horizontal direction include rubbing alignment films and photo-alignment films.

[0028] Orienting polymers can be used as materials for forming rubbing orientation films. Examples of oriented polymers include polyamides having amide bonds, gelatins, polyimides having imide bonds and their hydrolysates such as polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinylpyrrolidone, polyacrylic acid, and polyacrylic acid esters. Two or more oriented polymers may be used in combination.

[0029] A rubbing-oriented film can be obtained, for example, by dissolving an oriented polymer in a solvent to obtain an oriented polymer composition, applying the oriented polymer composition to a substrate and drying it, and further firing it if necessary to form a coating film, and then rubbing the coating film. The rubbing process can be performed, for example, by bringing the coating film into contact with a rotating rubbing roll around which a rubbing cloth is wrapped.

[0030] A photo-alignment film can be obtained, for example, by applying a photo-alignment film-forming composition containing a polymer or monomer having a photoreactive group and a solvent to a substrate, drying it, and then irradiating it with polarized light (preferably polarized UV). The direction of the alignment restricting force in the photo-alignment film can be arbitrarily controlled by selecting the polarization direction of the polarized light used for irradiation.

[0031] The above-mentioned photoreactive groups refer to groups that generate orientation ability upon light irradiation. Specifically, these include groups involved in photoreactions that are the origin of orientation ability, such as molecular orientation-inducing reactions, isomerization reactions, photodimerization reactions, photocrosslinking reactions, or photodegradation reactions, which are induced by light irradiation. As photoreactive groups, groups having unsaturated bonds, especially double bonds, are preferred, and groups having at least one selected from the group consisting of carbon-carbon double bonds (C=C bonds), carbon-nitrogen double bonds (C=N bonds), nitrogen-nitrogen double bonds (N=N bonds), and carbon-oxygen double bonds (C=O bonds) are more preferred.

[0032] Examples of photoreactive groups having a C=C bond include vinyl groups, polyene groups, stilbene groups, stilbazole groups, stilbazolium groups, chalcone groups, and cinnamoyl groups. Examples of photoreactive groups having a C=N bond include groups having structures such as aromatic Schiff bases and aromatic hydrazones. Examples of photoreactive groups having an N=N bond include azobenzene groups, azonaphthalene groups, aromatic heterocyclic azo groups, bisazo groups, formazan groups, and groups having an azoxybenzene structure. Examples of photoreactive groups having a C=O bond include benzophenone groups, coumarin groups, anthraquinone groups, and maleimide groups. These groups may have substituents such as alkyl groups, alkoxy groups, aryl groups, allyloxy groups, cyano groups, alkoxycarbonyl groups, hydroxyl groups, sulfonic acid groups, and halogenated alkyl groups.

[0033] As a vertically oriented film having orientation-restricting force in the vertical direction, materials that lower the surface tension of the substrate surface can be preferably applied. Examples of such materials include the above-mentioned oriented polymers, fluorine-based polymers such as perfluoroalkyls, polyimide compounds, silane compounds, and polysiloxane compounds obtained by their condensation reactions. Among these, silane compounds are preferred because they easily lower surface tension, silane compounds having alkyl groups at the molecular ends are more preferred, and silane compounds having alkyl groups with 6 to 20 carbon atoms are even more preferred. Since these silane compounds are often liquid, they may be applied directly to the substrate, or they may be dissolved in a solvent and applied to the substrate. Alternatively, they may be dissolved in a solvent together with various polymers as binders and applied to the substrate.

[0034] The thickness of the orientation film is, for example, 10 nm to 1000 nm, preferably 50 nm to 5000 nm, and more preferably 100 nm to 500 nm.

[0035] In the liquid crystal alignment curing layer, the liquid crystal compound can be in any suitable alignment state according to the desired optical properties. The alignment of the liquid crystal compound is performed by treating it at a temperature at which the liquid crystal phase is exhibited according to the type of the liquid crystal compound. By performing such temperature treatment, the liquid crystal compound assumes a liquid crystal state and aligns according to the alignment treatment direction of the substrate or the alignment film.

[0036] The fixation of the alignment state is performed, for example, by cooling the liquid crystal compound aligned as described above. When the liquid crystal compound is polymerizable or crosslinkable, the fixation of the alignment state is performed by subjecting the liquid crystal compound aligned as described above to a polymerization treatment or a crosslinking treatment.

[0037] In one embodiment, the liquid crystal alignment curing layer exhibits a refractive index characteristic of nx > ny ≥ nz. In this embodiment, typically, rod-shaped liquid crystal compounds are aligned in a state aligned in the direction of the slow axis of the liquid crystal alignment curing layer (homogeneous alignment). The liquid crystal compound is preferably polymerizable. When the liquid crystal compound is polymerizable, the alignment state of the liquid crystal compound can be fixed by polymerizing it after aligning the liquid crystal compound.

[0038] The liquid crystal alignment curing layer exhibiting the refractive index characteristic of nx > ny ≥ nz preferably exhibits an inverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light. Re(450) / Re(550) of the liquid crystal alignment curing layer is, for example, less than 1, may be 0.95 or less, may further be less than 0.90, and may further be 0.85 or less. Re(450) / Re(550) of the liquid crystal alignment curing layer is, for example, 0.75 or more.

[0039] Regarding the refractive index characteristic of nx > ny ≥ nz, "ny = nz" includes not only the case where ny and nz are exactly equal but also the case where they are substantially equal. Therefore, within a range that does not impair the effects of the present invention, ny < nz may occur. The Nz coefficient of the liquid crystal alignment curing layer exhibiting the refractive index characteristic of nx > ny ≥ nz is preferably 0.9 to 3, more preferably 0.9 to 2.5, still more preferably 0.9 to 1.5, and particularly preferably 0.9 to 1.3.

[0040] A liquid crystal alignment solidified layer exhibiting refractive index characteristics nx>ny≧nz can function as, for example, a λ / 4 plate. The in-plane phase difference Re(550) of a liquid crystal alignment solidified layer that can function as a λ / 4 plate is, for example, 100nm to 190nm, but may also be 110nm to 180nm, 130nm to 160nm, or 135nm to 155nm.

[0041] Furthermore, for example, a liquid crystal alignment solidified layer exhibiting refractive index characteristics nx>ny≧nz can function as a λ / 2 plate. The in-plane phase difference Re(550) of a liquid crystal alignment solidified layer that can function as a λ / 2 plate is, for example, 200nm to 330nm, but may also be 230nm to 330nm, 230nm to 290nm, or 250nm to 280nm.

[0042] As the above liquid crystal compound, any suitable liquid crystal polymer and / or liquid crystal monomer can be used. The liquid crystal polymer and liquid crystal monomer may be used individually or in combination. Specific examples of the above liquid crystal compound and methods for producing a liquid crystal orientation solidified layer are described, for example, in Japanese Patent Publication No. 2006-163343, Japanese Patent Publication No. 2006-178389, and International Publication No. 2018 / 123551. The descriptions in these publications are incorporated herein by reference.

[0043] In another embodiment, the liquid crystal alignment solidification layer is a so-called positive C plate exhibiting the refractive index characteristic nz>nx=ny. In this embodiment, typically, the liquid crystal compounds are oriented perpendicular to the main surface of the liquid crystal alignment solidification layer (homeotropic orientation). The liquid crystal compounds that can be homeotropically oriented may be liquid crystal monomers or liquid crystal polymers. Specific examples of methods for forming such liquid crystal compounds and liquid crystal alignment solidification layers can be found in paragraphs

[0020] to

[0028] of Japanese Patent Application Publication No. 2002-333642.

[0044] The phase difference Rth(550) in the thickness direction of the liquid crystal alignment solidified layer exhibiting the refractive index characteristics nz>nx=ny is preferably -20nm to -200nm, more preferably -30nm to -180nm, even more preferably -40nm to -160nm, and particularly preferably -50nm to -140nm. 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. The in-plane phase difference Re(550) of the liquid crystal alignment solidified layer exhibiting the refractive index characteristics nz>nx=ny is, for example, less than 10nm.

[0045] The thickness of the liquid crystal alignment solidification layer can be appropriately set according to the desired in-plane phase difference and / or phase difference in the thickness direction. The thickness of the liquid crystal alignment solidification layer is, for example, 10 μm or less, preferably 8 μm or less, more preferably 6 μm or less, even more preferably 5 μm or less, and may also be 4 μm or less. By satisfying such a thickness for the liquid crystal alignment solidification layer, the first phase difference film and the second phase difference film exhibit excellent smoothness, which can contribute to improved visibility when applied to a display system. The thickness of the liquid crystal alignment solidification layer is, for example, 1 μm or more.

[0046] The thickness of the first phase difference film is, for example, 1 μm to 10 μm, preferably 2 μm to 8 μm, and more preferably 2 μm to 6 μm. The thickness of the second phase difference film is as described above with respect to the thickness of the liquid crystal alignment solidification layer.

[0047] As described above, the first main surface of the first phase difference film is the liquid crystal alignment solidification layer surface, and the second main surface is the alignment film surface. Therefore, the two main surfaces of the first phase difference film may have different mechanical properties. The optical laminate according to the embodiment of the present invention includes a first phase difference film as a phase difference film containing a liquid crystal alignment solidification layer, in which the mechanical properties of both main surfaces satisfy a predetermined relationship, thereby suppressing the breakage of the phase difference film when it is integrated with a member having a curved surface. On the other hand, since both main surfaces of the second phase difference film are liquid crystal alignment solidification layer surfaces, they may have the same or similar mechanical properties.

[0048] The elastic modulus X1 of the first main surface and the elastic modulus X2 of the second main surface, measured by a nanoindenter of the first phase difference film, satisfy, for example, the relationship 0.58 ≤ X1 / X2 ≤ 1.65, preferably 0.60 ≤ X1 / X2 ≤ 1.63, and more preferably 0.62 ≤ X1 / X2 ≤ 1.60. X1 / X2 may be 0.80 or greater or 0.90 or greater. X1 is, for example, 1.0 GPa to 6.0 GPa, preferably 2.0 GPa to 5.0 GPa. X2 is, for example, 1.0 GPa to 6.0 GPa, preferably 2.0 GPa to 5.0 GPa.

[0049] The elastic recovery rate Y1 of the first main surface and the elastic recovery rate Y2 of the second main surface, measured by a nanoindenter of the first phase difference film, satisfy the relationship, for example, 0.80 ≤ Y1 / Y2 ≤ 1.10, preferably 0.81 ≤ Y1 / Y2 ≤ 1.08, and more preferably 0.82 ≤ Y1 / Y2 ≤ 1.06. Y1 is, for example, 50% to 90%, preferably 60% to 90%. Y2 is, for example, 50% to 90%, preferably 60% to 90%.

[0050] The hardness Z1 of the first main surface and the hardness Z2 of the second main surface of the first phase difference film, as measured by a nanoindenter, satisfy, for example, the relationship 0.80 ≤ Z1 / Z2 ≤ 1.20, preferably 0.82 ≤ Z1 / Z2 ≤ 1.19, and more preferably 0.85 ≤ Z1 / Z2 ≤ 1.18. Z1 is, for example, 0.1 GPa to 0.3 GPa, preferably 0.15 GPa to 0.25 GPa. Z2 is, for example, 0.1 GPa to 0.3 GPa, preferably 0.15 GPa to 0.25 GPa.

[0051] The elastic modulus X3 of the first main surface and the elastic modulus X4 of the second main surface, as measured by a nanoindenter of the second phase difference film, satisfy, for example, the relationship 0.80 ≤ X3 / X4 ≤ 1.20, preferably 0.85 ≤ X3 / X4 ≤ 1.15, and more preferably 0.90 ≤ X3 / X4 ≤ 1.10. X3 and X4 are independently, for example, 1.0 GPa to 6.0 GPa, preferably 2.0 GPa to 5.0 GPa.

[0052] The elastic recovery rates Y3 of the first main surface and Y4 of the second main surface, measured by a nanoindenter of the second phase difference film, satisfy, for example, the relationship 0.80 ≤ Y3 / Y4 ≤ 1.20, preferably 0.85 ≤ Y3 / Y4 ≤ 1.15, and more preferably 0.90 ≤ Y3 / Y4 ≤ 1.10. Y3 and Y4 are independently, for example, 50% to 90%, preferably 60% to 90%.

[0053] The hardness Z3 of the first main surface and the hardness Z4 of the second main surface, as measured by a nanoindenter of the second phase difference film, satisfy the relationship, for example, 0.70 ≤ Z3 / Z4 ≤ 1.30, preferably 0.80 ≤ Z3 / Z4 ≤ 1.20, and more preferably 0.85 ≤ Z3 / Z4 ≤ 1.15. Z3 and Z4 are independently, for example, 0.1 GPa to 0.3 GPa, preferably 0.15 GPa to 0.25 GPa.

[0054] The elastic modulus (X1, X3, and X4) and hardness (Z1, Z3, and Z4) of the liquid crystal alignment solidification layer can be increased, for example, by increasing the curing time (e.g., increasing the light irradiation time during photocuring) or by increasing the number of curing reaction points (e.g., the number of photocuring reaction points). The elastic recovery rate (Y1, Y3, and Y4) of the liquid crystal alignment solidification layer can be increased, for example, by increasing the layer thickness, decreasing the curing time (e.g., decreasing the light irradiation time during photocuring), or by decreasing the number of curing reaction points. The elastic modulus (X2) and hardness (Z2) of the alignment film can be increased, for example, by increasing the curing time during curing or by increasing the number of curing reaction points. The elastic recovery rate (Y2) of the alignment film can be increased, for example, by increasing the layer thickness, decreasing the curing time, or decreasing the number of curing reaction points.

[0055] [Adhesive layer] The adhesive layer described above can be composed of any suitable adhesive. Specific examples of adhesives include acrylic adhesives, rubber adhesives, silicone adhesives, polyester adhesives, urethane adhesives, epoxy adhesives, and polyether adhesives. By adjusting the type, number, combination, and blending ratio of monomers forming the base resin of the adhesive, as well as the amount of crosslinking agent, reaction temperature, reaction time, etc., an adhesive with desired properties for a specific purpose can be prepared. The base resin of the adhesive may be used alone or in combination of two or more types. Acrylic resins are preferably used as the base resin. Specifically, the adhesive layer is preferably composed of an acrylic adhesive.

[0056] The thickness of the adhesive layer may be, for example, 3 μm or more, 5 μm or more, 50 μm or less, or 25 μm or less.

[0057] [Reflective polarizing element] The above-described reflective polarizing member transmits light polarized parallel to its transmission axis (typically linearly polarized light) while maintaining its polarization state, and reflects light polarized in other states (typically light polarized perpendicular to its transmission axis). The reflective polarizing member is typically composed of a multilayer film (sometimes referred to as a reflective polarizing film). In this case, the thickness of the reflective polarizing member is, for example, 10 μm to 150 μm, preferably 20 μm to 100 μm, and more preferably 30 μm to 60 μm.

[0058] Examples of commercially available reflective polarizing films include the product names "DBEF" and "APF" from 3M, and "APCF" from Nitto Denko.

[0059] The orthogonal transmittance (Tc) of the reflective polarizing member (reflective polarizing film) may be, for example, 0.01% to 3%. The single-element transmittance (Ts) of the reflective polarizing member (reflective polarizing film) may be, for example, 43% to 49%, preferably 45% to 47%. The degree of polarization (P) of the reflective polarizing member (reflective polarizing film) may be, for example, 92% to 99.99%.

[0060] The above orthogonal transmittance, single-element transmittance, and polarization degree can be measured, for example, using a UV-Vis spectrophotometer. The polarization degree P can be calculated using a UV-Vis spectrophotometer to measure the single-element transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc, and then calculated from the obtained Tp and Tc using the following formula. Note that Ts, Tp, and Tc are Y values ​​measured using a 2-degree field of view (C light source) according to JIS Z 8701 and corrected for luminous efficiency. Polarization degree P(%)={(Tp-Tc) / (Tp+Tc)} 1 / 2 ×100

[0061] [Absorbing polarizing element] The above-mentioned absorption-type polarizing member may typically include a resin film containing a dichroic substance (sometimes referred to as an absorption-type polarizing film). The thickness of the absorption-type polarizing film is, for example, 1 μm or more and 20 μm or less, but may also be 2 μm or more and 15 μm or less, 12 μm or less, 10 μm or less, 8 μm or less, or 5 μm or less.

[0062] The above-mentioned absorption polarizing film may be made from a single layer of resin film, or it may be made using a laminate of two or more layers.

[0063] When manufactured from a single layer of resin film, for example, an absorption polarizing film can be obtained by subjecting a hydrophilic polymer film, such as a polyvinyl alcohol (PVA) film, a partially formalized PVA film, or a partially saponified ethylene-vinyl acetate copolymer film, to dyeing treatment with a dichroic substance such as iodine or a dichroic dye, and stretching treatment. Among these, an absorption polarizing film obtained by dyeing a PVA film with iodine and uniaxially stretching it is preferred.

[0064] The above iodine staining is carried out, for example, by immersing the PVA-based film in an iodine aqueous solution. The stretching ratio for the above uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after the staining treatment, or during the staining process. Alternatively, staining may be performed after stretching. If necessary, the PVA-based film may be subjected to swelling, crosslinking, washing, drying, etc.

[0065] When using the above-mentioned laminate of two or more layers, examples of laminates include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a laminate of a resin substrate and a PVA-based resin layer coated and formed on the resin substrate. An absorption polarizing film obtained using a laminate of a resin substrate and a PVA-based resin layer coated and formed on the resin substrate can be produced, for example, by applying a PVA-based resin solution to a resin substrate, drying it to form a PVA-based resin layer on the resin substrate, and obtaining a laminate of a resin substrate and a PVA-based resin layer; or by stretching and dyeing the laminate to make the PVA-based resin layer an absorption polarizing film. In this embodiment, preferably, a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin is formed on one side of the resin substrate. Stretching typically includes immersing the laminate in an aqueous boric acid solution and stretching it. Furthermore, stretching may, if necessary, further include air-stretching the laminate at a high temperature (e.g., 95°C or higher) before stretching in the aqueous boric acid solution. In addition, in this embodiment, the laminate is preferably subjected to a drying shrinkage treatment in which it shrinks by 2% or more in the width direction by heating while being transported in the longitudinal direction. Typically, the manufacturing method of this embodiment includes applying an air-assisted stretching treatment, a dyeing treatment, a water-based stretching treatment, and a drying shrinkage treatment to the laminate in this order. By introducing auxiliary stretching, it is possible to increase the crystallinity of PVA even when PVA is coated on a thermoplastic resin, making it possible to achieve high optical properties. At the same time, by increasing the orientation of PVA in advance, it is possible to prevent problems such as a decrease in the orientation of PVA and dissolution when immersed in water in the subsequent dyeing and stretching processes, making it possible to achieve high optical properties. Furthermore, when the PVA-based resin layer is immersed in a liquid, the disorder of the orientation of polyvinyl alcohol molecules and the decrease in orientation can be suppressed compared to when the PVA-based resin layer does not contain halides. As a result, the optical properties of the absorption polarizing film obtained through processing steps in which the laminate is immersed in a liquid, such as dyeing and water-based stretching, can be improved. Furthermore, by shrinking the laminate in the width direction through a drying shrinkage treatment, the optical properties can be improved.The resulting resin substrate / absorbent polarizing film laminate may be used as is (i.e., the resin substrate may be used as a protective layer for the absorbent polarizing film), or an appropriate protective layer may be laminated on the peeled surface obtained by removing the resin substrate from the resin substrate / absorbent polarizing film laminate, or on the surface opposite to the peeled surface, depending on the purpose. Details of such a method for manufacturing an absorbent polarizing film are described, for example, in Japanese Patent Application Publication No. 2012-73580 and Japanese Patent No. 6470455. The entire contents of these publications are incorporated herein by reference.

[0066] The orthogonal transmittance (Tc) of the absorbing polarizing member (absorbing polarizing film) is preferably 0.5% or less, more preferably 0.1% or less, and even more preferably 0.05% or less. The single-layer transmittance (Ts) of the absorbing polarizing member (absorbing polarizing film) is, for example, 41.0% to 45.0%, and preferably 42.0% or more. The degree of polarization (P) of the absorbing polarizing member (absorbing polarizing film) is, for example, 99.0% to 99.997%, and preferably 99.9% or more.

[0067] [Protective material] The above protective member typically includes a base material. The base material can be composed of any suitable film. Examples of materials that make up the main component of the film constituting the base material include cellulose resins such as triacetylcellulose (TAC), polyester resins, polyvinyl alcohol resins, polycarbonate resins, polyamide resins, polyimide resins, polyethersulfone resins, polysulfone resins, polystyrene resins, cycloolefin resins such as polynorbornene, polyolefin resins, (meth)acrylic resins, acetate resins, and other resins. The thickness of the base material is preferably 5 μm to 80 μm, more preferably 10 μm to 40 μm, and even more preferably 15 μm to 35 μm.

[0068] The protective member preferably comprises a substrate and a surface treatment layer formed on the substrate. In a protective member having a surface treatment layer, the surface treatment layer may be positioned as the outermost layer. The surface treatment layer may have any suitable function. For example, the surface treatment layer preferably has an anti-reflective function from the viewpoint of improving the visibility of the display system. The surface treatment layer may also include a hard coat layer. The thickness of the surface treatment layer is preferably 1 μm to 20 μm, more preferably 2 μm to 15 μm, and even more preferably 3 μm to 10 μm.

[0069] [Phase difference member made of resin film] A phase difference member composed of a resin film may, for example, be a stretched resin film. A phase difference member composed of a resin film may have any suitable optical properties (e.g., refractive index properties, in-plane phase difference, Nz coefficient, wavelength dispersion properties, etc.) depending on the purpose. In one embodiment, a phase difference member composed of a resin film may exhibit refractive index properties of nx>ny≧nz and may exhibit optical properties similar to those of a liquid crystal alignment solidified layer that can function as a λ / 4 plate or a λ / 2 plate.

[0070] Examples of resins included in the above-mentioned resin film include polycarbonate resins, polyester carbonate resins, polyester resins, polyvinyl acetal resins, polyarylate resins, cyclic olefin resins, cellulose resins, polyvinyl alcohol resins, polyamide resins, polyimide resins, polyether resins, polystyrene resins, and acrylic resins. These resins may be used individually or in combination. Methods of combination include blending and copolymerization. When the phase difference member exhibits inverse dispersion wavelength characteristics, a resin film containing a polycarbonate resin or a polyester carbonate resin (hereinafter sometimes simply referred to as a polycarbonate resin) can be suitably used.

[0071] Any suitable polycarbonate resin can be used as the above-mentioned polycarbonate resin. For example, the polycarbonate resin includes structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, and structural units derived from at least one dihydroxy compound selected from the group consisting of alicyclic diols, alicyclic dimethanol, di, tri, or polyethylene glycol, and alkylene glycol or spiroglycol. Preferably, the polycarbonate resin includes structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, structural units derived from alicyclic dimethanol, and / or structural units derived from di, tri, or polyethylene glycol; more preferably, it includes structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, and structural units derived from di, tri, or polyethylene glycol. The polycarbonate resin may optionally include structural units derived from other dihydroxy compounds. Further details regarding polycarbonate resins suitably used for phase difference members and methods for forming phase difference members are described, for example, in Japanese Patent Publication No. 2014-10291, Japanese Patent Publication No. 2014-26266, Japanese Patent Publication No. 2015-212816, Japanese Patent Publication No. 2015-212817, and Japanese Patent Publication No. 2015-212818, and the descriptions in these publications are incorporated herein by reference.

[0072] The thickness of the phase difference member, which is made of resin film, is, for example, 10 μm to 100 μm, preferably 10 μm to 70 μm, more preferably 10 μm to 60 μm, and even more preferably 20 μm to 50 μm.

[0073] [Adhesive layer] The adhesive layer is typically an adhesive layer or a tack layer. For example, an adhesive layer for bonding phase difference films together may be an adhesive layer. Also, for example, an adhesive layer for bonding a phase difference film to other optical components such as a reflective polarizing member, and an adhesive layer for bonding other optical components together, may be a tack layer. Examples of adhesives for forming the adhesive layer include UV-curing adhesives and water-based adhesives. The thickness of the adhesive layer is, for example, 0.5 μm to 2 μm, more preferably 0.8 μm to 1.5 μm. By using an adhesive layer with a small thickness, an optical laminate with improved smoothness can be obtained (for example, an optical laminate in which a first phase difference film and a second phase difference film are laminated with an adhesive layer of 0.5 μm to 2 μm thickness). Such an optical laminate can be applied to a display system to contribute to the refinement of the displayed image. The same explanation as above applies to the tack layer.

[0074] [Differentiation] According to another embodiment of the present invention, an optical laminate is provided that includes a second phase difference film having a first main surface and a second main surface, wherein the second phase difference film is composed of a liquid crystal alignment solidification layer. With respect to the second phase difference film, as described above, when the elastic moduli of the first main surface and the second main surface of the second phase difference film measured by a nanoindenter are denoted as X3 and X4, respectively, X3 and X4 typically satisfy the relationship 0.80 ≤ X3 / X4 ≤ 1.20. With an optical laminate that includes only a second phase difference film in which the mechanical properties of both main surfaces are similar as the phase difference film including the liquid crystal alignment solidification layer, it is possible to suppress the breakage of the phase difference film when it is integrated with a member having a curved surface.

[0075] Figures 6 and 7 are schematic cross-sectional views showing the general configuration of an example of an optical laminate according to the above embodiment, respectively.

[0076] The optical laminate 100D shown in Figure 6 includes a second phase difference film 130 having a first main surface 130a and a second main surface 130b. The second phase difference film 130 is composed of a liquid crystal alignment solidification layer 132. The optical laminate 100D further includes an adhesive layer 120 disposed on the first main surface 130a side of the second phase difference film 130.

[0077] The optical laminate 100E shown in Figure 7 includes two second phase difference films 130 laminated via an adhesive layer 140. The two second phase difference films 130 are arranged so that their first main surfaces 130a face each other. An adhesive layer 120 is located on the second main surface 130b side of one of the second phase difference films 130.

[0078] In optical laminates 100D and E, the orientation of the first main surface 130a and the second main surface 130b of the second phase difference film 130 is not limited. Specifically, in optical laminates 100D and E, the second phase difference film 130 may be arranged so that the first main surface 130a and the second main surface 130b are on opposite sides. Furthermore, a release liner may be temporarily attached to the surface of the adhesive layer 120 until the optical laminates 100D and E are put into use.

[0079] The optical laminate according to the above embodiment may further include other optical components depending on the application, purpose, etc. Examples of such optical components include reflective polarizing components, absorbing polarizing components, protective components, and phase difference components made of resin films. These other optical components are laminated, for example, via an adhesive layer. The other optical components and adhesive layer are as described above. The optical laminate of this embodiment does not necessarily include a first phase difference film that satisfies the relationship 0.58 ≤ X1 / X2 ≤ 1.65.

[0080] The total thickness of the optical laminate described above (excluding the outermost adhesive layer 120) may be, for example, 5 μm to 1000 μm, preferably 10 μm to 500 μm.

[0081] B. Display System Figure 8 is a schematic diagram showing the general configuration of an example of a display system to which the optical laminate described in Section A may be applied. Figure 8 schematically illustrates the arrangement and shape of each component of the display system 2. The display system 2 comprises a display element 12, a reflecting section 14 including a reflective polarizing member, a first lens section 16, a half mirror 18, a first λ / 4 member 20, a second λ / 4 member 22, and a second lens section 24. The reflecting section 14 is positioned in front of the display element 12 on the display surface 12a side and can reflect light emitted from the display element 12. The first lens section 16 is positioned in the optical path between the display element 12 and the reflecting section 14, and the half mirror 18 is positioned between the display element 12 and the first lens section 16. The first λ / 4 member 20 is positioned in the optical path between the display element 12 and the half mirror 18, and the second λ / 4 member 22 is positioned in the optical path between the half mirror 18 and the reflecting section 14.

[0082] The display element 12 is, for example, a liquid crystal display or an organic EL display, and has a display surface 12a for displaying an image. Light emitted from the display surface 12a passes through a polarizing member (typically a polarizing film) that may be included in the display element 12, and is emitted as first linearly polarized light.

[0083] The first linearly polarized light incident on the first λ / 4 member 20 is converted into the first circularly polarized light. The first λ / 4 member 20 may be integrally provided with the display element 12. For example, the first λ / 4 member 20 may be integrally provided with a polarizing member that may be included in the display element 12.

[0084] The half-mirror 18 transmits light emitted from the display element 12 and reflects the light reflected by the reflecting part 14 back towards the reflecting part 14. The half-mirror 18 is integrally provided with the first lens part 16.

[0085] The second λ / 4 member 22 can allow light reflected by the reflective portion 14 and the half mirror 18 to pass through the reflective portion 14, which includes the reflective polarizing member. The second λ / 4 member 22 may be provided integrally with the first lens portion 16.

[0086] The first circularly polarized light emitted from the first λ / 4 member 20 passes through the half mirror 18 and the first lens portion 16 and is converted into a second linearly polarized light by the second λ / 4 member 22. The second linearly polarized light emitted from the second λ / 4 member 22 is reflected towards the half mirror 18 without passing through the reflective polarizing member included in the reflecting portion 14. At this time, the polarization direction of the second linearly polarized light incident on the reflective polarizing member included in the reflecting portion 14 is in the same direction as the reflection axis of the reflective polarizing member. Therefore, the second linearly polarized light incident on the reflecting portion 14 is reflected by the reflective polarizing member.

[0087] The second linearly polarized light reflected by the reflective section 14 is converted into a second circularly polarized light by the second λ / 4 member 22, and the second circularly polarized light emitted from the second λ / 4 member 22 passes through the first lens section 16 and is reflected by the half mirror 18. The circularly polarized light reflected by the half mirror 18 passes through the first lens section 16 and is converted into a third linearly polarized light by the second λ / 4 member 22. The third linearly polarized light is transmitted through the reflective polarizing member included in the reflective section 14. At this time, the polarization direction of the third linearly polarized light incident on the reflective polarizing member included in the reflective section 14 is in the same direction as the transmission axis of the reflective polarizing member. Therefore, the third linearly polarized light incident on the reflective section 14 is transmitted through the reflective polarizing member. From the viewpoint of improving visibility, the reflective section 14 may further include an absorbing polarizing member positioned in front of the reflective polarizing member. In this case, the reflection axis of the reflective polarizing member and the absorption axis of the absorptive polarizing member may be arranged substantially parallel to each other, and the transmission axis of the reflective polarizing member and the transmission axis of the absorptive polarizing member may be arranged substantially parallel to each other.

[0088] Light that has passed through the reflective section 14 passes through the second lens section 24 and enters the user's eye 26.

[0089] For example, the absorption axis of the polarizing member included in the display element 12 and the reflection axis of the reflective polarizing member included in the reflection section 14 may be arranged substantially parallel to each other, or substantially orthogonal to each other.

[0090] The first λ / 4 member 20 and the second λ / 4 member 22 may each be a single-layer configuration including only a λ / 4 plate as the phase difference layer, or a laminated configuration including a λ / 2 plate and a λ / 4 plate as the phase difference layer. By combining a λ / 2 plate and a λ / 4 plate, a broadband λ / 4 member that can function as a λ / 4 plate over a wide wavelength range can be obtained. In one embodiment, the first λ / 4 member 20 and the second λ / 4 member 22 may each be a single-layer configuration including only a λ / 4 plate as the phase difference layer. In another embodiment, the first λ / 4 member 20 and the second λ / 4 member 22 may each be a laminated configuration including a λ / 2 plate and a λ / 4 plate as the phase difference layer.

[0091] The in-plane phase difference Re(550) of the λ / 4 plates included in the first λ / 4 member and the second λ / 4 member of the above single-layer configuration is, for example, 100 nm to 190 nm, but may also be 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. Preferably, each of the above λ / 4 plates exhibits an inverse dispersion wavelength characteristic in which the phase difference value increases with the wavelength of the measured light. The Re(450) / Re(550) of the above λ / 4 plates is, for example, 0.75 or more and less than 1, and may also be 0.8 or more and 0.95 or less.

[0092] The in-plane phase difference Re(550) of the λ / 4 plates included in the first and second λ / 4 members, which are broadband λ / 4 members, is, for example, 100 nm to 190 nm, but may also be 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The in-plane phase difference Re(550) of the λ / 2 plates included in the first and second λ / 4 members, which are broadband λ / 4 members, is, for example, 200 nm to 330 nm, but may also be 230 nm to 330 nm, 230 nm to 290 nm, or 250 nm to 280 nm. Preferably, the λ / 4 plates and λ / 2 plates exhibit inverse dispersion wavelength characteristics in which the phase difference value increases with the wavelength of the measured light. The Re(450) / Re(550) values ​​for the above λ / 4 plate and λ / 2 plate are, for example, 0.75 or more and less than 1, and may also be 0.8 or more and 0.95 or less.

[0093] When the first λ / 4 member 20 has a single-layer configuration, the angle between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the first λ / 4 member 20 is, for example, 40° to 50°, may be 42° to 48°, or may be approximately 45°.

[0094] When the first λ / 4 member 20 has a laminated configuration of a λ / 2 plate and a λ / 4 plate (in other words, when the first λ / 4 member 20 is a broadband λ / 4 member), the angle between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the λ / 2 plate is, for example, 5° to 25°, and may also be 10° to 20°, 12° to 18°, or about 15°; the angle between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the λ / 4 plate is, for example, 65° to 85°, and may also be 70° to 80°, 72° to 78°, or about 75°; and the angle between the slow axis of the λ / 2 plate and the slow axis of the λ / 4 plate is, for example, 50° to 70°, and may also be 55° to 65°, 57° to 63°, or about 60° (axis relationship A). Alternatively, the angle between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the λ / 2 plate may be, for example, 65° to 85°, but may also be 70° to 80°, 72° to 78°, or about 75°; the angle between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the λ / 4 plate may be, for example, 5° to 25°, but may also be 10° to 20°, 12° to 18°, or about 15°; and the angle between the slow axis of the λ / 2 plate and the slow axis of the λ / 4 plate may be, for example, 50° to 70°, but may also be 55° to 65°, 57° to 63°, or about 60° (axis relationship B). In one embodiment, the λ / 2 plate and the λ / 4 plate may be arranged in this order facing forward.

[0095] When the second λ / 4 member 22 has a single-layer configuration, the angle between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the second λ / 4 member 22 is, for example, 40° to 50°, may be 42° to 48°, or may be approximately 45°.

[0096] When the second λ / 4 member 22 has a laminated configuration of a λ / 2 plate and a λ / 4 plate (in other words, when the second λ / 4 member 22 is a broadband λ / 4 member), the angle between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the λ / 2 plate is, for example, 5° to 25°, and may also be 10° to 20°, 12° to 18°, or about 15°; the angle between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the λ / 4 plate is, for example, 65° to 85°, and may also be 70° to 80°, 72° to 78°, or about 75°; and the angle between the slow axis of the λ / 2 plate and the slow axis of the λ / 4 plate is, for example, 50° to 70°, and may also be 55° to 65°, 57° to 63°, or about 60° (axis relationship C). Alternatively, the angle between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the λ / 2 plate may be, for example, 65° to 85°, but may also be 70° to 80°, 72° to 78°, or about 75°; the angle between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the λ / 4 plate may be, for example, 5° to 25°, but may also be 10° to 20°, 12° to 18°, or about 15°; and the angle between the slow axis of the λ / 2 plate and the slow axis of the λ / 4 plate may be, for example, 50° to 70°, but may also be 55° to 65°, 57° to 63°, or about 60° (axis relationship D). In one embodiment, the λ / 4 plate and the λ / 2 plate may be arranged in this order facing forward.

[0097] When both the first λ / 4 member and the second λ / 4 member are broadband λ / 4 members, it is preferable to use a combination of the first λ / 4 member with axial relationship A and the second λ / 4 member with axial relationship D, or to use a combination of the first λ / 4 member with axial relationship B and the second λ / 4 member with axial relationship C. In this case, the absorption axis of the polarizing member included in the display element 12 and the reflection axis of the reflective polarizing member may be substantially orthogonal.

[0098] Figure 9 is a schematic cross-sectional view illustrating an example of a configuration in which an optical laminate 100F, including a member positioned between the first lens portion and the second lens portion, is integrated with the first lens portion 16 having a curved surface portion 16a in the display system 2. Although not shown, a half-mirror may also be provided integrally with the first lens portion 16.

[0099] The optical laminate 100F comprises, in this order, an adhesive layer 120, a phase difference member 23 exhibiting refractive index characteristics of nz≧nx=ny, a single-layer second λ / 4 member 22, a reflective polarizing member 14a, an absorbing polarizing member 14b, and a protective member 30. By using the phase difference member 23 exhibiting refractive index characteristics of nz≧nx=ny, light leakage (for example, light leakage in an oblique direction) can be prevented. As shown in Figure 9, it is preferable that the second λ / 4 member 22 is positioned in front of (to the right in Figure 9) the phase difference member 23 exhibiting refractive index characteristics of nz≧nx=ny. In the optical laminate 100F, each member other than the adhesive layer 120 is bonded together via an adhesive layer (not shown). For example, the phase difference member 23 exhibiting refractive index characteristics of nz≧nx=ny and the second λ / 4 member 22 can be bonded together via an adhesive layer or an adhesive layer. Also, for example, other members can be bonded together via an adhesive layer. The phase difference member 23, which exhibits refractive index characteristics of nz≧nx=ny, may be omitted depending on the purpose. Furthermore, although the optical laminate 100F includes a reflective portion 14 containing a reflective polarizing member 14a and an absorptive polarizing member 14b, the reflective portion 14 or the absorptive polarizing member 14b may be omitted depending on the purpose.

[0100] The optical laminate 100F is the optical laminate described in Section A. For example, in the optical laminate 100F, at least one of the phase difference member 23 and the second λ / 4 member 22 exhibiting refractive index characteristics nz≧nx=ny is the first phase difference film, and the other is the second phase difference film, or both are the first phase difference film, or both the phase difference member 23 and the second λ / 4 member 22 exhibiting refractive index characteristics nz≧nx=ny are the second phase difference films.

[0101] As a specific example, the optical laminate 100F may be an optical laminate that satisfies any of the following conditions (i) to (iv). Such an optical laminate 100F can be suitably applied to the display system 2, and when integrated with the curved surface of the first lens portion, the breakage of the phase difference film can be suppressed. (i) The phase difference member 23 exhibiting refractive index characteristics of nz≧nx=ny is a first phase difference film composed of a laminate of a liquid crystal alignment solidification layer and an alignment film, which is a positive C plate, and the second λ / 4 member 22 is a first phase difference film composed of a laminate of a liquid crystal alignment solidification layer and an alignment film that can function as a λ / 4 plate. (ii) The phase difference member 23 exhibiting refractive index characteristics nz≧nx=ny is a first phase difference film composed of a laminate of a liquid crystal alignment solidification layer which is a positive C plate and an alignment film, and the second λ / 4 member 22 is a second phase difference film composed of a liquid crystal alignment solidification layer which can function as a λ / 4 plate. (iii) The phase difference member 23 exhibiting refractive index characteristics nz≧nx=ny is a second phase difference film composed of a liquid crystal alignment solidification layer which is a positive C plate, and the second λ / 4 member 22 is a first phase difference film composed of a laminate of a liquid crystal alignment solidification layer and an alignment film which can function as a λ / 4 plate. (iv) The phase difference member 23 exhibiting refractive index characteristics nz≧nx=ny is a second phase difference film composed of a liquid crystal alignment solidification layer which is a positive C plate, and the second λ / 4 member 22 is a second phase difference film composed of a liquid crystal alignment solidification layer which can function as a λ / 4 plate.

[0102] Figure 10 is a schematic cross-sectional view illustrating an example of a configuration in which an optical laminate 100G, including a member positioned between the first lens portion and the second lens portion, is integrated with the first lens portion 16 having a curved surface portion 16a in the display system 2. Although not shown, a half-mirror may also be provided integrally with the first lens portion 16.

[0103] The optical laminate 100G comprises, in this order, an adhesive layer 120, a λ / 4 plate 22a, a λ / 2 plate 22b, a reflective polarizing member 14a, an absorbing polarizing member 14b, and a protective member 30. The λ / 4 plate 22a and the λ / 2 plate 22b are laminated at the predetermined angle described above, thereby forming a second λ / 4 member 22 that can function as a broadband λ / 4 member. As shown in Figure 10, it is preferable that the λ / 2 plate 22b is positioned in front of the λ / 4 plate 22a (to the right in Figure 10). In the optical laminate 100G, each member other than the adhesive layer 120 is bonded together via an adhesive layer (not shown). For example, the λ / 4 plate 22a and the λ / 2 plate 22b can be bonded together via an adhesive layer or an adhesive layer. Also, for example, other members can be bonded together via an adhesive layer. The optical laminate 100G may further include a phase difference member exhibiting refractive index characteristics of nz≧nx=ny, if necessary. The phase difference member exhibiting refractive index characteristics of nz≧nx=ny may be provided behind the second λ / 4 member 22 (on the left side in Figure 10). The optical laminate 100G also includes a reflective section 14 containing a reflective polarizing member 14a and an absorptive polarizing member 14b, but the reflective section 14 or the absorptive polarizing member 14b may be omitted depending on the purpose.

[0104] The optical laminate 100G is the optical laminate described in Section A. For example, in the optical laminate 100G, at least one of the λ / 4 plate 22a and the λ / 2 plate 22b is the first phase difference film and the other is the second phase difference film, or both are the first phase difference film, or both the λ / 4 plate 22a and the λ / 2 plate 22b are the second phase difference films.

[0105] As a specific example, the optical laminate 100G may be an optical laminate that satisfies any of the following conditions (v) to (viii). Such an optical laminate 100G can be suitably applied to the display system 2, and when integrated with the curved surface of the first lens portion, the breakage of the phase difference film can be suppressed. (v) The λ / 4 plate 22a is a first phase difference film composed of a laminate of a liquid crystal alignment solidification layer and an alignment film that can function as a λ / 4 plate, and the λ / 2 plate 22b is a first phase difference film composed of a laminate of a liquid crystal alignment solidification layer and an alignment film that can function as a λ / 2 plate. (vi) The λ / 4 plate 22a is a first phase difference film composed of a laminate of a liquid crystal alignment solidification layer and an alignment film that can function as a λ / 4 plate, and the λ / 2 plate 22b is a second phase difference film composed of a liquid crystal alignment solidification layer that can function as a λ / 2 plate. (vii) The λ / 4 plate 22a is a second phase difference film composed of a liquid crystal alignment solidification layer that can function as a λ / 4 plate, and the λ / 2 plate 22b is a first phase difference film composed of a laminate of a liquid crystal alignment solidification layer and an alignment film that can function as a λ / 2 plate. (viii) The λ / 4 plate 22a is a second phase difference film composed of a liquid crystal alignment solidification layer that can function as a λ / 4 plate, and the λ / 2 plate 22b is a second phase difference film composed of a liquid crystal alignment solidification layer that can function as a λ / 2 plate. [Examples]

[0106] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way to these examples. The test and evaluation methods in the examples are as follows. When "parts" is written, it means "parts by weight" unless otherwise specified, and when "%" is written, it means "percent by weight" unless otherwise specified.

[0107] (1) Thickness Thicknesses of 10 μm or less were measured using a scanning electron microscope (JEOL Ltd., product name "JSM-7100F"). Thicknesses exceeding 10 μm were measured using a digital micrometer (Anritsu Corporation, product name "KC-351C"). (2) Phase difference value Phase difference / elliptic polarization measurement devices (manufactured by Oji Instruments Co., Ltd., product names "KOBRA-HBR" and "KOBRA-HBPR") were used to measure the phase difference value at a predetermined wavelength at 23°C. (3) Transmittance and polarization degree of the polarizing material The single-unit transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc of the polarizing material were measured using a spectrophotometer (Otsuka Electronics Co., Ltd., "LPF-200"). These Ts, Tp, and Tc values ​​are Y values ​​obtained by measuring under a 2-degree field of view (C light source) according to JIS Z8701 and correcting for luminous sensitivity. From the obtained Tp and Tc values, the polarization degree of the polarizing material was determined using the following formula. Degree of polarization (%)={(Tp-Tc) / (Tp+Tc)} 1 / 2 ×100 (4) modulus of elasticity, hardness, and elastic recovery rate A phase difference film fixed to a predetermined support was used as the measurement sample, and nanoindation measurements were performed under the following conditions. • Measuring device: Manufactured by Hysitron Inc., product name "Triboindenter" ·Indenter used: Berkovich (triangular pyramid type) • Measurement method: Single indentation measurement ·Measurement temperature: Room temperature (25℃) • Indentation depth setting: 20nm

[0108] Using the software (triboscan) attached to the measuring device, the elastic modulus (S√π / 2√A), hardness (Pmax / A), and elastic recovery rate ((hmax-hf) / hmax×100) were calculated from the load-displacement curve obtained by measurement (S: contact stiffness (slope of the tangent to the unloading curve), A: contact projected area (area in contact between the indenter and the sample), Pmax: maximum load (load when the sample is indented to the deepest extent), hmax: maximum displacement (amount of displacement when the sample is indented to the deepest extent), hf: amount of plastic deformation (depth of deformation mark after unloading)).

[0109] The above nanoindation measurements were performed on both the surface of the phase difference film opposite to the substrate (first main surface) when it was formed on the substrate, and on the substrate-exposed surface (second main surface) of the phase difference film when it was transferred to another substrate via adhesive and the substrate was peeled off. The average values ​​of N=5 were taken as the elastic modulus, hardness, and elastic recovery rate of each main surface of the phase difference film.

[0110] [Manufacturing Example 1: Phase difference film 1A including a liquid crystal alignment solidification layer that can function as a λ / 4 plate] 55 parts by weight of the compound represented by formula (I), 25 parts by weight of the compound represented by formula (II), and 20 parts by weight of the compound represented by formula (III) were added to 400 parts by weight of cyclopentanone (CPN), and then heated to 60°C and stirred to dissolve. [ka]

[0111] The solution of the above compound was allowed to return to room temperature, and 3 parts by weight of Irgacure 907 (BASF Japan), 0.2 parts by weight of Megafac F-554 (DIC), and 0.1 parts by weight of p-methoxyphenol (MEHQ) were added to the solution and the mixture was further stirred. The solution after stirring was clear and homogeneous. The resulting solution was filtered through a 0.20 μm membrane filter to obtain a polymerizable composition. A diagonally oriented norbornene-based film (Zeonor Film (ZD12) manufactured by Zeon Corporation, 23 μm thick, with an in-plane phase difference of 140 nm) was prepared. The polymerizable composition was applied to the obliquely stretched norbornene-based film using a bar coater, and the liquid crystal compound was oriented by heating at 100°C for 3 minutes. After cooling to room temperature, the film was exposed to a nitrogen atmosphere with an integrated light intensity of 400 mJ / cm². 2 A liquid crystal alignment solidified layer (4 μm thick) was formed on an obliquely stretched norbornene-based film by photocuring using ultraviolet light. The in-plane phase difference Re(590) of the liquid crystal alignment solidification layer was 144 nm. Furthermore, the Re(450) / Re(550) ratio of the liquid crystal alignment solidification layer was 0.851, indicating inverse dispersion wavelength characteristics. This liquid crystal alignment solidification layer can function as a λ / 4 plate. When this liquid crystal alignment solidification layer was peeled off from the obliquely stretched norbornene-based film, a phase difference film 1A consisting of a liquid crystal alignment solidification layer capable of functioning as a λ / 4 plate was obtained.

[0112] [Manufacturing Example 2-1: Phase difference film 2A including a liquid crystal alignment solidification layer which is a positive C plate] We prepared a product from DNP Corporation named "MCP-N(80)1330-D". The product "MCP-N(80)1330-D" has a configuration in which a liquid crystal alignment solidification layer, which is a positive C plate, is formed on the surface of a vertical alignment film provided on a substrate. When this liquid crystal alignment solidification layer is peeled off from the substrate, the alignment film remains in close contact with the liquid crystal alignment solidification layer, and a phase difference film 2A having the configuration of [liquid crystal alignment solidification layer / alignment film which is a positive C plate] is obtained.

[0113] [Manufacturing Example 2-2: Phase difference film 2B including a liquid crystal alignment solidification layer that can function as a λ / 4 plate] 55 parts by weight of the compound represented by formula (I), 25 parts by weight of the compound represented by formula (II), and 20 parts by weight of the compound represented by formula (III) were added to 400 parts by weight of cyclopentanone (CPN), and then heated to 60°C and stirred to dissolve. The solution of the above compound was allowed to return to room temperature, and 3 parts by weight of Irgacure 907 (BASF Japan), 0.2 parts by weight of Megafac F-554 (DIC), and 0.1 parts by weight of p-methoxyphenol (MEHQ) were added to the solution and the mixture was further stirred. The solution after stirring was clear and homogeneous. The resulting solution was filtered through a 0.20 μm membrane filter to obtain a polymerizable composition. Furthermore, a polyimide solution for the alignment film was applied to a 0.7 mm thick glass substrate using a spin coating method, dried at 100°C for 10 minutes, and then baked at 200°C for 60 minutes to obtain a coating film (5 μm thick). The obtained coating film was then rubbed using a commercially available rubbing device to form an alignment film. Next, the polymerizable composition was applied to the surface of the substrate on the side where the orientation film was formed by spin coating and dried at 100°C for 2 minutes. After the obtained coating film has cooled to room temperature, it is heated using a high-pressure mercury lamp at 30 mW / cm². 2 A liquid crystal alignment solidification layer (3 μm thick) was formed by irradiating with ultraviolet light at this intensity for 30 seconds. The in-plane phase difference Re(590) of the liquid crystal alignment solidification layer was 140 nm. Furthermore, the Re(450) / Re(550) ratio of the liquid crystal alignment solidification layer was 0.851, indicating inverse dispersion wavelength characteristics. This liquid crystal alignment solidification layer can function as a λ / 4 plate. When this liquid crystal alignment solidification layer is peeled off from the glass substrate, the alignment film remains in close contact with the liquid crystal alignment solidification layer, and a phase difference film 2B having a configuration of [liquid crystal alignment solidification layer / alignment film that can function as a λ / 4 plate] is obtained.

[0114] [Manufacturing Example 2-3: Phase difference film 2C containing a liquid crystal alignment solidification layer that can function as a λ / 4 plate] 55 parts by weight of the compound represented by formula (I), 25 parts by weight of the compound represented by formula (II), and 20 parts by weight of the compound represented by formula (III) were added to 400 parts by weight of cyclopentanone (CPN), and then heated to 60°C and stirred to dissolve. The solution of the above compound was allowed to return to room temperature, and 3 parts by weight of Irgacure 907 (BASF Japan), 0.2 parts by weight of Megafac F-554 (DIC), and 0.1 parts by weight of p-methoxyphenol (MEHQ) were added to the solution and the mixture was further stirred. The solution after stirring was clear and homogeneous. The resulting solution was filtered through a 0.20 μm membrane filter to obtain a polymerizable composition. Furthermore, a polyimide solution for the alignment film was applied to a 0.7 mm thick glass substrate using a spin coating method, dried at 100°C for 10 minutes, and then baked at 250°C for 60 minutes to obtain a coating film (4 μm thick). The obtained coating film was then rubbed using a commercially available rubbing device to form an alignment film. Next, the polymerizable composition was applied to the surface of the substrate on the side where the orientation film was formed by spin coating and dried at 100°C for 2 minutes. After the obtained coating film has cooled to room temperature, it is heated using a high-pressure mercury lamp at 30 mW / cm². 2 A liquid crystal alignment solidification layer (3 μm thick) was formed by irradiating with ultraviolet light at this intensity for 30 seconds. The in-plane phase difference Re(590) of the liquid crystal alignment solidification layer was 140 nm. Furthermore, the Re(450) / Re(550) ratio of the liquid crystal alignment solidification layer was 0.851, indicating inverse dispersion wavelength characteristics. This liquid crystal alignment solidification layer can function as a λ / 4 plate. When this liquid crystal alignment solidification layer is peeled off from the glass substrate, the alignment film remains in close contact with the liquid crystal alignment solidification layer, and a phase difference film 2C having a configuration of [liquid crystal alignment solidification layer / alignment film that can function as a λ / 4 plate] is obtained.

[0115] [Manufacturing Example 3: Absorbing Polarizing Material] (Fabrication of absorbing polarizing films) As a thermoplastic resin substrate, an amorphous isophthalic copolymer polyethylene terephthalate film (thickness: 100 μm) in a long length with a Tg of approximately 75°C was used, and one side of the resin substrate was subjected to corona treatment. A PVA aqueous solution (coating solution) was prepared by dissolving 100 parts by weight of a PVA-based resin, which was prepared by mixing polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Mitsubishi Chemical Corporation, trade name "Gosenex Z410") in a 9:1 ratio, with 13 parts by weight of potassium iodide. A PVA aqueous solution was applied to the corona-treated surface of a resin substrate and dried at 60°C to form a 13 μm thick PVA-based resin layer, thereby creating a laminate. The resulting laminate was uniaxially stretched 2.4 times in the longitudinal direction (longitudinal direction) in an oven at 130°C (air-assisted stretching). Next, the laminate was immersed for 30 seconds in an insolubilization bath at a liquid temperature of 40°C (a boric acid aqueous solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) (insolubilization treatment). Next, the film was immersed for 60 seconds in a staining bath at 30°C (an iodine aqueous solution obtained by mixing iodine and potassium iodide in a weight ratio of 1:7 with 100 parts by weight of water) while adjusting the concentration so that the transmittance (Ts) of the final absorption polarizing film would be the desired value (staining treatment). Next, the material was immersed for 30 seconds in a crosslinking bath at a liquid temperature of 40°C (a boric acid aqueous solution obtained by mixing 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with 100 parts by weight of water) (crosslinking treatment). Subsequently, the laminate was immersed in a boric acid aqueous solution (boric acid concentration 4% by weight, potassium iodide concentration 5% by weight) at a liquid temperature of 70°C, and uniaxially stretched in the longitudinal direction (longitudinal direction) between rolls with different peripheral speeds to achieve a total stretch ratio of 5.5 times (underwater stretching treatment). Subsequently, the laminate was immersed in a washing bath at a liquid temperature of 20°C (an aqueous solution obtained by mixing 4 parts by weight of potassium iodide with 100 parts by weight of water) (washing treatment). Subsequently, the laminate was dried in an oven maintained at approximately 90°C while being brought into contact with a SUS (stainless steel) heated roll whose surface temperature was maintained at approximately 75°C (drying shrinkage treatment). The shrinkage rate in the width direction of the laminate due to the drying shrinkage treatment was 5.2%. In this way, an absorption-type polarizing film with a thickness of approximately 5 μm was formed on a resin substrate.

[0116] (Fabrication of absorption-type polarizing members) An acrylic film having a lactone ring structure with a thickness of 40 μm was bonded to the surface of the obtained absorbing polarizing film (the side opposite to the resin substrate) via an ultraviolet-curing adhesive as a protective layer. Specifically, the curing adhesive was coated to a thickness of 2 μm and bonded using a roll machine. Then, UV light was irradiated from the acrylic film side to cure the adhesive. Next, the resin substrate was peeled off. In this way, an absorbing polarizing member A having the configuration of acrylic film / absorbing polarizing film was obtained. The transmittance (Ts) of the absorbing polarizing member A was 43.4%, and the degree of polarization was 99.993%.

[0117] [Manufacturing Example 4: Reflective Polarizing Material] Nitto Denko's reflective polarizing film "APCF" was used as the reflective polarizing component A.

[0118] [Manufacturing Example 5: Adhesive Layer] A monomer mixture containing 94.9 parts by weight of butyl acrylate, 5 parts by weight of acrylic acid, and 0.1 parts by weight of 2-hydroxyethyl acrylate was charged into a four-necked flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser. Furthermore, 0.3 parts by weight of dibenzoyl peroxide was added to 100 parts by weight of this monomer mixture as a polymerization initiator along with ethyl acetate. After introducing nitrogen gas to purge the flask with nitrogen while gently stirring, the polymerization reaction was carried out for 7 hours while maintaining the temperature of the liquid in the flask at 60°C. Next, ethyl acetate was added to the resulting reaction solution to adjust the solid content concentration to 30% by weight, and a solution of an acrylic polymer with a weight-average molecular weight (Mw) of 2.2 million was prepared. An acrylic adhesive was prepared by mixing 0.6 parts by weight of trimethylolpropane / tolylene diisocyanate adduct (product name: Coronate L, manufactured by Tosoh Corporation) and 0.075 parts by weight of silane coupling agent (product name: KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) with 100 parts by weight of solids of the obtained acrylic polymer solution. The obtained acrylic adhesive was coated onto a base film, and the resulting coating film on the base film was dried in an oven to form an adhesive layer A with a thickness of 15 μm.

[0119] [Manufacturing Example 6: Adhesives] Adhesive A was prepared by mixing 62 parts by weight of hydroxyethyl acrylamide (manufactured by Kojinsha, trade name "HEAA"), 25 parts by weight of acryloylmorpholine (manufactured by Kojinsha, trade name "ACMO"), 7 parts by weight of PEG400# diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Light Acrylate 9EG-A"), 3 parts by weight of BASF's trade name "Irgacure 907", and 3 parts by weight of Nippon Kayaku's trade name "KAYACURE DETX-S" for 60 minutes.

[0120] [Example 1] A laminate 1 was obtained by bonding a reflective polarizing member A to the absorbing polarizing film side of an absorbing polarizing member A via an adhesive layer A. At this time, the bonding was performed so that the transmission axis of the absorbing polarizing film and the transmission axis of the reflective polarizing member A were parallel. An adhesive layer A was transferred from the base film to the reflective polarizing member side surface of the laminate 1. Next, a phase difference film 2A was transferred from the base to the surface of adhesive layer A, and another adhesive layer A was transferred from the base film to the surface on the side where the base was peeled off. As described above, an optical laminate having a laminated structure of [absorbing polarizing member A / reflective polarizing member A / phase difference film 2A / adhesive layer A] was obtained.

[0121] [Example 2] Adhesive A was applied to the liquid crystal alignment solidification layer side surface of phase difference film 1A, which was laminated on a substrate, so that the thickness after curing would be 1 μm to 2 μm. Next, phase difference film 2A, which was laminated on a substrate, was laminated so that the liquid crystal alignment solidification layer side surface was facing the coated layer side, and adhesive A was cured to obtain laminate 2. The adhesive layer A was transferred from the base film to the reflective polarizing member side surface of the laminate 1 obtained in the same manner as in Example 1. The base material on the phase difference film 1A side of the laminate 2 was peeled off, and the peeled surface was bonded to the adhesive layer A surface of the laminate 1. At this time, the bonded layers were made such that the slow axis of the phase difference film 1A made a 45° angle with the transmission axis of the reflective polarizing member. Next, the substrate on the phase difference film 2A side of the laminate 2 was peeled off, and another adhesive layer A was transferred from the substrate film to the peeled surface (orientation film surface). As described above, an optical laminate having a laminated structure of [absorbent polarizing member A / reflective polarizing member A / phase difference film 1A / phase difference film 2A / adhesive layer A] was obtained. [Example 3] Adhesive A was applied to the liquid crystal alignment solidification layer side surface of phase difference film 2A, which was laminated on a substrate, so that the cured thickness would be 1 μm to 2 μm. Next, another phase difference film 2A, which was laminated on a substrate, was laminated so that the liquid crystal alignment solidification layer side surface became the coated layer side, and the adhesive A was cured to obtain a laminate 3. The adhesive layer A was transferred from the base film to the reflective polarizing member side surface of the laminate 1 obtained in the same manner as in Example 1. The base material on one side of the laminate 3 was peeled off, and the peeled surface was bonded to the surface of the adhesive layer A of the laminate 1. Next, the substrate on the other side of the laminate 3 was peeled off, and another adhesive layer A was transferred from the substrate film to the peeled surface (orientation film surface). As described above, an optical laminate having a laminated structure of [absorbing polarizing member A / reflective polarizing member A / phase difference film 2A / phase difference film 2A / adhesive layer A] was obtained.

[0122] [Comparative Example 1] An adhesive layer A was transferred from the base film to the reflective polarizing member side surface of the laminate 1 obtained in the same manner as in Example 1. Next, a phase difference film 2B was transferred from the base to the surface of adhesive layer A, and another adhesive layer A was transferred from the base film to the surface on the side from which the base was peeled off. At this time, the phase difference film 2B was bonded so that its slow axis made a 45° angle with the transmission axis of the reflective polarizing member. As described above, an optical laminate having a laminated structure of [absorbing polarizing member A / reflective polarizing member A / phase difference film 2B / adhesive layer A] was obtained.

[0123] [Comparative Example 2] An adhesive layer A was transferred from the base film to the reflective polarizing member side surface of the laminate 1 obtained in the same manner as in Example 1. Next, a phase difference film 2C was transferred from the base to the surface of adhesive layer A, and another adhesive layer A was transferred from the base film to the surface on the side from which the base was peeled off. At this time, the phase difference film 2C was bonded so that its slow axis made a 45° angle with the transmission axis of the reflective polarizing member. As described above, an optical laminate having a laminated structure of [absorbing polarizing member A / reflective polarizing member A / phase difference film 2C / adhesive layer A] was obtained.

[0124] [Comparative Example 3] Adhesive A was applied to the liquid crystal alignment solidification layer side surface of phase difference film 1A, which was laminated on the substrate, so that the thickness after curing would be 1 μm to 2 μm. Next, phase difference film 2B, which was laminated on the substrate, was laminated so that the liquid crystal alignment solidification layer side surface was facing the coated layer side, and adhesive A was cured to obtain a laminate 4. The adhesive layer A was transferred from the base film to the reflective polarizing member side surface of the laminate 1 obtained in the same manner as in Example 1. The base material on the phase difference film 1A side of the laminate 4 was peeled off, and the peeled surface was bonded to the adhesive layer A surface of the laminate 1. Next, the substrate on the phase difference film 2B side of the laminate 4 was peeled off, and another adhesive layer A was transferred from the substrate film to the peeled surface (orientation film surface). As described above, an optical laminate having a laminated structure of [absorbent polarizing member A / reflective polarizing member A / phase difference film 1A / phase difference film 2B / adhesive layer A] was obtained.

[0125] [Comparative Example 4] Adhesive A was applied to the liquid crystal alignment solidification layer side surface of phase difference film 1A, which was laminated on a substrate, so that the cured thickness would be 1 μm to 2 μm. Next, phase difference film 2C, which was laminated on a substrate, was laminated so that the liquid crystal alignment solidification layer side surface was facing the coated layer side, and adhesive A was cured to obtain a laminate 5. The adhesive layer A was transferred from the base film to the reflective polarizing member side surface of the laminate 1 obtained in the same manner as in Example 1. The base material on the phase difference film 1A side of the laminate 5 was peeled off, and the peeled surface was bonded to the adhesive layer A surface of the laminate 1. Next, the substrate on the phase difference film 2C side of the laminate 5 was peeled off, and another adhesive layer A was transferred from the substrate film to the peeled surface (orientation film surface). As described above, an optical laminate having a laminated structure of [absorbent polarizing member A / reflective polarizing member A / phase difference film 1A / phase difference film 2C / adhesive layer A] was obtained.

[0126] [Reference example 1] An adhesive layer A was transferred from the base film to the reflective polarizing member side surface of the laminate 1 obtained in the same manner as in Example 1. Next, a phase difference film 1A was transferred from the base to the surface of adhesive layer A, and another adhesive layer A was transferred from the base film to the surface on the side where the base was peeled off. At this time, the phase difference film 1A was bonded so that its slow axis made a 45° angle with the transmission axis of the reflective polarizing member. As described above, an optical laminate having a laminated structure of [absorbing polarizing member A / reflective polarizing member A / phase difference film 1A / adhesive layer A] was obtained.

[0127] <Evaluation of adhesive bonding on curved surfaces> The optical laminates of each example, comparative example, and reference example were bonded to a lens having a circular concave portion in plan view. Specifically, using a TOM (Three-Dimensional Overlay Method) molding machine (manufactured by Fuse Vacuum Co., Ltd.), each optical laminate was bonded to the concave portion of the lens via an adhesive layer A at a temperature of 140°C to obtain an integrated member. The radius of curvature of the concave portion was 38.6 mm.

[0128] The integrated components were observed under a microscope to check whether or not a fracture had occurred in the phase contrast film, and were evaluated according to the following criteria. <Evaluation Criteria> ○: The phase difference film is not broken. ×: The phase difference film is broken.

[0129] The results of the curved surface bonding evaluation are shown in Tables 1 and 2. Additionally, the results of the nanoindentation measurement of the phase difference film are shown in Table 3.

[0130] [Table 1]

[0131] [Table 2]

[0132] [Table 3]

[0133] In the optical laminates of the examples and reference examples that did not include a phase difference film in which the elastic modulus ratio between the first main surface and the second main surface exceeded 1.65 during lamination to a curved surface, no rupture of the phase difference film occurred. On the other hand, in the optical laminate of the comparative example, phase difference films 2B and 2C, in which the elastic modulus ratio between the first main surface and the second main surface exceeded 1.65, ruptured.

[0134] The present invention is not limited to the embodiments described above, and various modifications are possible. For example, the configurations shown in the embodiments above can be replaced with configurations that are substantially the same, configurations that produce the same effects, or configurations that can achieve the same purpose. [Industrial applicability]

[0135] The display system according to an embodiment of the present invention can be used, for example, in a display device such as VR goggles. [Explanation of Symbols]

[0136] 2 Display system, 12 Display element, 12a Display surface, 14 Reflective part, 14a Reflective polarizing member, 14b Absorbing polarizing member, 16 First lens part, 18 Half mirror, 20 First λ / 4 member, 22 Second λ / 4 member, 24 Second lens part, 30 Protective member, 100 (A~F) Optical laminate, 110 First phase difference film, 120 Adhesive layer, 130 Second phase difference film.

Claims

1. An optical laminate comprising a first phase difference film having a first main surface and a second main surface, and to be integrated with a member having a curved surface portion, The first phase difference film is a laminate of an orientation solidification layer of liquid crystal compound and an orientation film arranged in this order from the first main surface side. An optical laminate in which, when the elastic moduli of the first main surface and the second main surface of the first phase difference film measured by a nanoindenter are X1 and X2, respectively, X1 and X2 satisfy the relationship 0.58 ≤ X1 / X2 ≤ 1.

65.

2. The optical laminate according to claim 1, wherein when the elastic recovery rates of the first main surface and the second main surface of the first phase difference film, measured by a nanoindenter, are Y1 and Y2, respectively, Y1 and Y2 satisfy the relationship 0.80 ≤ Y1 / Y2 ≤ 1.

10.

3. The optical laminate according to claim 1, wherein when the hardness of the first main surface and the second main surface of the first phase difference film, measured by a nanoindenter, are Z1 and Z2, respectively, Z1 and Z2 satisfy the relationship 0.80 ≤ Z1 / Z2 ≤ 1.

20.

4. The optical laminate according to claim 1, further comprising a second phase difference film composed of an orientation solidification layer of a liquid crystal compound.

5. The first phase difference film and the second phase difference film are laminated with an adhesive layer in between. The optical laminate according to claim 4, wherein the thickness of the adhesive layer is 0.5 μm or more and 2 μm or less.

6. Further containing an adhesive layer, The optical laminate according to claim 4, wherein the adhesive layer, the first phase difference film, and the second phase difference film are arranged in this order.

7. The optical laminate according to claim 1, wherein the radius of curvature of the curved portion of the member having the curved portion is 20 mm or more and 150 mm or less.

8. The optical laminate according to claim 1, wherein the elastic modulus X1 of the first main surface of the first phase difference film is 1.0 GPa or more.

9. A display element having a display surface that emits light representing an image forward via a polarizing member, A reflective polarizing member is positioned in front of the display element and reflects light emitted from the display element, A first lens portion having a curved surface is arranged in the optical path between the display element and the reflective polarizing member, A half-mirror is disposed between the display element and the first lens portion, which transmits light emitted from the display element and reflects the light reflected by the reflective polarizing member toward the reflective polarizing member, A first λ / 4 member is arranged in the optical path between the display element and the half mirror, Used in a display system comprising a second λ / 4 member positioned in the optical path between the half mirror and the reflective polarizing member, The optical laminate according to claim 1, which is integrated with the first lens portion.

10. A method for manufacturing an optical member, comprising integrating the optical laminate described in claim 1 onto the curved portion of a member having a curved portion under heating conditions.

Images