Optical laminate and display system

Abstract

To provide an optical laminate having excellent moisture resistance while improving the visibility of VR goggles. The optical laminate (1) includes a polarizing member (13), a first λ / 4 member (20), an adhesive layer (50), and another retardation layer (23) in this order. The polarizing member (13) includes a polarizing film (13a) containing iodine and a protective layer (13b). The first λ / 4 member (20) is disposed adjacent to the polarizing film (13a). The optical laminate (1) has a moisture permeability of 100 g / m at 40°C and 92% RH. 2 The adhesive layer 50 has a thickness of 2.0 μm or more.

Description

[Technical Field]

[0001] The present invention relates to an optical stack and a display system. [Background technology]

[0002] Image display devices, such as liquid crystal display devices and electroluminescence (EL) display devices (e.g., organic EL display devices), are rapidly becoming popular. In image display devices, optical components such as retardation components and polarizing components are generally used to realize image display and improve image display performance (see, for example, Patent Document 1). These optical components can be integrated in advance and mounted on the image display device as an optical laminate.

[0003] In recent years, new applications for image display devices have been developed. For example, goggles with displays (VR goggles) for realizing virtual reality (VR) have begun to be commercialized. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-103286 Summary of the Invention [Problem to be solved by the invention]

[0005] Since VR goggles are being considered for use in a variety of situations, moisture resistance may be required, and moisture resistance may also be required for optical laminates containing optical members used in VR goggles.

[0006] In view of the above, a main object of the present invention is to provide an optical laminate that improves the visibility of VR goggles while also having excellent moisture resistance. [Means for solving the problem]

[0007] 1. An optical laminate according to an embodiment of the present invention is an optical laminate used in a display method, the display method including the steps of: passing light representing an image emitted via a polarizing member through a first λ / 4 member; passing the light that has passed through the first λ / 4 member through a half mirror and a first lens unit; passing the light that has passed through the half mirror and the first lens unit through a second λ / 4 member; reflecting the light that has passed through the second λ / 4 member toward the half mirror with a reflective polarizing member; and enabling the light reflected by the reflective polarizing member and the half mirror to pass through the reflective polarizing member with the second λ / 4 member. The optical laminate includes, in this order, the polarizing member, the first λ / 4 member, an adhesive layer, and another retardation layer. The polarizing member includes a polarizing film containing iodine and a protective layer. The first λ / 4 member is disposed adjacent to the polarizing film. The optical laminate has a moisture permeability of 100 g / m at 40°C and 92% RH. 2 24 hours or less, and the thickness of the adhesive layer is 2.0 μm or more. 2. In the optical laminate described in 1 above, the first λ / 4 member may be made of a resin film. 3. In the optical laminate according to 1 or 2 above, the first λ / 4 member may have a thickness of 30 μm or more. 4. In the optical laminate according to any one of the above items 1 to 3, the adhesive layer may be a cured resin layer. 5. In the optical laminate according to any one of the above 1 to 4, a pressure-sensitive adhesive layer having a thickness of 20 μm or less may be provided between the polarizing film and the first λ / 4 member. 6. In the optical laminate described in any one of 1 to 5 above, the number of bubbles present in the adhesive layer is 10 / m 2 It may be the following: 7. A display system according to another embodiment of the present invention is a display system for displaying an image to a user, comprising: a display element having a display surface that emits light representing an image forward through a polarizing element; a reflective polarizing element disposed in front of the display element and reflecting the light emitted from the display element; a first lens unit disposed on an optical path between the display element and the reflective polarizing element; and a second lens unit disposed between the display element and the first lens unit, which transmits the light emitted from the display element and reflects the light reflected by the reflective polarizing element. a half mirror that reflects light toward an optical element, a first λ / 4 element that is disposed on an optical path between the display element and the half mirror, and a second λ / 4 element that is disposed on an optical path between the half mirror and the reflective polarizing element, the optical laminate including the polarizing element, the first λ / 4 element, an adhesive layer, and another retardation layer in this order, the polarizing element including a polarizing film containing iodine and a protective layer, the first λ / 4 element being disposed adjacent to the polarizing film, and having a moisture permeability of 100 g / m at 40°C and 92% RH 2 24 hours or less, and the thickness of the adhesive layer is 2.0 μm or more. [Effects of the Invention]

[0008] According to the optical laminate according to the embodiment of the present invention, it is possible to achieve excellent moisture resistance while improving the visibility of VR goggles. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing a general configuration of a display system according to an embodiment of the present invention. [Figure 2] 1 is a schematic cross-sectional view showing the general configuration of an optical laminate according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. In order to clarify the description, the drawings may schematically show the width, thickness, shape, etc. of each part compared to the embodiments, but these are merely examples and do not limit the interpretation of the present invention. Furthermore, in the drawings, the same or equivalent elements are given the same reference numerals, and duplicate explanations may be omitted.

[0011] (Definition 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 in which the in-plane refractive index is greatest (i.e., the slow axis direction), "ny" is the refractive index in the direction perpendicular to the slow axis in the plane (i.e., the fast axis direction), and "nz" is the refractive index in the thickness direction. (2) In-plane phase difference (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 calculated 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 calculated 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 calculated by Nz=Rth / Re. (5)Angle When angles are referred to herein, unless otherwise specified, the angles include both clockwise and counterclockwise angles relative to a reference direction. Thus, for example, "45°" means ±45°. Furthermore, in this specification, "substantially parallel" includes a range of 0°±10°, preferably within a range of 0°±5°, more preferably within a range of 0°±3°, and even more preferably within a range of 0°±1°. "Substantially perpendicular" includes a range of 90°±10°, preferably within a range of 90°±5°, more preferably within a range of 90°±3°, and even more preferably within a range of 90°±1°.

[0012] [Display System] FIG. 1 is a schematic diagram showing the overall configuration of a display system according to one embodiment of the present invention. FIG. 1 schematically illustrates the arrangement and shape of each component of a display system 2. The display system 2 includes a display element 12, a reflector 14 including a reflective polarizing member, a first lens unit 16, a half mirror 18, a first λ / 4 member 20, a second λ / 4 member 22, and a second lens unit 24. The reflector 14 is disposed in front of the display surface 12a of the display element 12 and can reflect light emitted from the display element 12. The first lens unit 16 is disposed on the optical path between the display element 12 and the reflector 14, and the half mirror 18 is disposed between the display element 12 and the first lens unit 16. The first λ / 4 member 20 is disposed on the optical path between the display element 12 and the half mirror 18, and the second λ / 4 member 22 is disposed on the optical path between the half mirror 18 and the reflector 14.

[0013] The display element 12 is, for example, a liquid crystal display or an organic EL display (preferably, a micro organic EL display), and has a display surface 12a for displaying an image. The light emitted from the display surface 12a passes through, for example, a polarizing member (typically, a polarizing film) that may be included in the display element 12, and is converted into first linearly polarized light.

[0014] The first linearly polarized light incident on the first λ / 4 member 20 is converted into first circularly polarized light. The first λ / 4 member 20 may be provided integrally with the display element 12. For example, the first λ / 4 member 20 may be provided integrally with a polarizing member that may be included in the display element 12.

[0015] The half mirror 18 transmits light emitted from the display element 12 and reflects the light reflected by the reflecting portion 14 back toward the reflecting portion 14. The half mirror 18 is provided integrally with the first lens portion 16.

[0016] The second λ / 4 member 22 can transmit light reflected by the reflecting unit 14 and the half mirror 18 through the reflecting unit 14, which includes a reflective polarizing member. The second λ / 4 member 22 may be provided integrally with the first lens unit 16.

[0017] The first circularly polarized light output from the first λ / 4 member 20 passes through the half mirror 18 and the first lens unit 16, and is converted into the second linearly polarized light by the second λ / 4 member 22. The second linearly polarized light output from the second λ / 4 member 22 is reflected toward the half mirror 18 without passing through the reflective polarizing member included in the reflecting unit 14. At this time, the polarization direction of the second linearly polarized light that entered the reflective polarizing member included in the reflecting unit 14 is the same as the reflection axis of the reflective polarizing member. Therefore, the second linearly polarized light that entered the reflecting unit 14 is reflected by the reflective polarizing member.

[0018] The second linearly polarized light reflected by the reflecting unit 14 is converted into 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 unit 16 and is reflected by the half mirror 18. The circularly polarized light reflected by the half mirror 18 passes through the first lens unit 16 and is converted into third linearly polarized light by the second λ / 4 member 22. The third linearly polarized light passes through the reflective polarizing member included in the reflecting unit 14. At this time, the polarization direction of the third linearly polarized light incident on the reflective polarizing member included in the reflecting unit 14 is the same direction as the transmission axis of the reflective polarizing member. Therefore, the third linearly polarized light incident on the reflecting unit 14 passes through the reflective polarizing member.

[0019] The light transmitted through the reflecting portion 14 passes through the second lens portion 24 and enters the eye 26 of the user.

[0020] 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 reflector 14 may be disposed approximately parallel to each other or approximately perpendicular to each other. The angle formed 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°, or may be 42° to 48°, or may be approximately 45°. The angle formed 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°, or may be 42° to 48°, or may be approximately 45°.

[0021] The in-plane retardation Re(550) of the first λ / 4 member 20 is, for example, 100 nm to 190 nm, may be 110 nm to 180 nm, may be 130 nm to 160 nm, or may be 135 nm to 155 nm.

[0022] The first λ / 4 component 20 preferably exhibits an inverse dispersion wavelength characteristic in which the retardation value increases with the wavelength of the measurement light. The Re(450) / Re(550) of the first λ / 4 component 20 is, for example, less than 1, and may be 0.95 or less, or even less than 0.90, or even 0.85 or less. The Re(450) / Re(550) of the first λ / 4 component 20 is, for example, 0.75 or more.

[0023] In one embodiment, the first λ / 4 member 20 satisfies all of Re(400) / Re(550) < 0.85, Re(650) / Re(550) > 1.03, and Re(750) / Re(550) > 1.05. The first λ / 4 member 20 preferably satisfies at least one selected from 0.65 < Re(400) / Re(550) < 0.80 (preferably, 0.7 < Re(400) / Re(550) < 0.75), 1.0 < Re(650) / Re(550) < 1.25 (preferably, 1.05 < Re(650) / Re(550) < 1.20), and 1.05 < Re(750) / Re(550) < 1.40 (preferably, 1.08 < Re(750) / Re(550) < 1.36), more preferably satisfies at least two, and even more preferably satisfies all of them.

[0024] The first λ / 4 member 20 preferably exhibits a refractive index characteristic showing a relationship of nx > ny ≧ nz. Here, "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 not impairing the effects of the present invention, ny < nz may occur. The Nz coefficient of the first λ / 4 member 20 is preferably 0.9 to 3, more preferably 0.9 to 2.5, even more preferably 0.9 to 1.5, and particularly preferably 0.9 to 1.3. <000​​​​​​​​​​In one embodiment, the second λ / 4 member 22 satisfies all of Re(400) / Re(550) < 0.85, Re(650) / Re(550) > 1.03, and Re(750) / Re(550) > 1.05. The second λ / 4 member 22 preferably satisfies at least one selected from 0.65 < Re(400) / Re(550) < 0.80 (preferably, 0.7 < Re(400) / Re(550) < 0.75), 1.0 < Re(650) / Re(550) < 1.25 (preferably, 1.05 < Re(650) / Re(550) < 1.20), and 1.05 < Re(750) / Re(550) < 1.40 (preferably, 1.08 < Re(750) / Re(550) < 1.36), more preferably satisfies at least two, and even more preferably satisfies all of them.

[0028] The second λ / 4 member 22 preferably exhibits a refractive index characteristic of nx > ny ≧ nz. Here, "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 second λ / 4 member 22 is preferably 0.9 to 3, more preferably 0.9 to 2.5, even more preferably 0.9 to 1.5, and particularly preferably 0.9 to 1.3.

[0029] The first λ / 4 member 20 and the second λ / 4 member 22 are each formed of any suitable material that can satisfy the above characteristics. For example, the first λ / 4 member 20 and the second λ / 4 member 22 can each be a resin film (typically, a stretched resin film) or an alignment cured layer of a liquid crystal compound (liquid crystal alignment cured layer). The first λ / 4 member 20 and the second λ / 4 member 22 may be members having the same configuration (forming material, thickness, optical characteristics, etc.) or members having different configurations.

[0030] The reflective polarizing element can transmit light polarized parallel to its transmission axis (typically, linearly polarized light) while maintaining its polarization state, and reflect light polarized in other states. The orthogonal transmittance (Tc) of the reflective polarizing element can be, for example, 0.01% to 3%. The single transmittance (Ts) of the reflective polarizing element can be, for example, 43% to 49%, preferably 45% to 47%. The degree of polarization (P) of the reflective polarizing element can be, for example, 92% to 99.99%. The reflective polarizing element is typically composed of a film having a multilayer structure (sometimes referred to as a reflective polarizing film). Commercially available reflective polarizing films include, for example, "DBEF" and "APF" manufactured by 3M and "APCF" manufactured by Nitto Denko Corporation.

[0031] As described above, the first λ / 4 member 20 may be provided integrally with a polarizing member that may be included in the display element 12. In this case, it is preferable to form an optical laminate in which the polarizing member that may be included in the display element 12 and the first λ / 4 member 20 are integrated.

[0032] [Optical laminate] 2 is a schematic cross-sectional view showing the general configuration of an optical laminate according to one embodiment of the present invention. The optical laminate 1 includes a polarizing member 13 that can be included in a display element 12, and a first retardation member 21 disposed on one side (the front side, the upper side in FIG. 2) of the polarizing member 13.

[0033] The polarizing member 13 includes at least a polarizing film 13a. In the example shown in FIG. 2, the polarizing member 13 includes a protective layer 13b in addition to the polarizing film 13a. The polarizing member 13 has a laminated structure of the polarizing film 13a and the protective layer 13b. The polarizing film 13a and the protective layer 13b are laminated together via, for example, an adhesive layer (not shown). In this case, the polarizing member 13 includes the polarizing film 13a, the adhesive layer, and the protective layer 13b, in this order. In the example shown in FIG. 2, the protective layer 13b is provided only on one side of the polarizing film 13a. With this configuration, for example, the optical laminate 1 can be made thinner and have low reflectivity.

[0034] The polarizing film 13a is typically an absorptive polarizing film and may be made of a resin film containing a dichroic material (typically, iodine). The thickness of the polarizing film 13a is, for example, 1 μm or more and 15 μm or less, preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 7 μm or less. The thickness of the polarizing member 13 is preferably 60 μm or less, more preferably 50 μm or less. The thickness of the polarizing member 13 is, for example, 10 μm or more, and may be 20 μm or more.

[0035] The absorptive polarizing film may be made from a single layer of resin film or may be made from a laminate of two or more layers.

[0036] When fabricating from a single-layer resin film, an absorptive polarizing film can be obtained by dyeing 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 with iodine or a dichroic substance such as a dichroic dye, stretching, etc. Among these, an absorptive polarizing film obtained by dyeing a PVA film with iodine and uniaxially stretching it is preferred.

[0037] The dyeing with iodine is carried out, for example, by immersing the PVA film in an aqueous iodine solution. The stretching ratio of the uniaxial stretching is preferably 3 to 7 times. The stretching may be carried out after the dyeing treatment or while dyeing. Alternatively, the stretching may be followed by dyeing. If necessary, the PVA film may be subjected to a swelling treatment, a crosslinking treatment, a washing treatment, a drying treatment, etc.

[0038] Examples of laminates produced using the two or more layer laminate include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a laminate of a resin substrate and a PVA-based resin layer formed by coating on the resin substrate. An absorptive polarizing film obtained using a laminate of a resin substrate and a PVA-based resin layer formed by coating on the resin substrate can be produced, for example, by applying a PVA-based resin solution to the resin substrate and drying the resin substrate to form a PVA-based resin layer on the resin substrate, thereby obtaining a laminate of the resin substrate and the PVA-based resin layer; and then stretching and dyeing the laminate to convert the PVA-based resin layer into an absorptive polarizing film. In this embodiment, a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin is preferably formed on one side of the resin substrate. The stretching typically involves immersing the laminate in an aqueous boric acid solution and stretching it. Furthermore, the stretching may further include, if necessary, in-air stretching of the laminate at an elevated temperature (e.g., 95°C or higher) before stretching in the aqueous boric acid solution. Additionally, in this embodiment, the laminate is preferably subjected to a drying shrinkage treatment by heating while being transported in the longitudinal direction, thereby shrinking the laminate by 2% or more in the width direction. Typically, the manufacturing method of this embodiment includes subjecting the laminate to an in-air auxiliary stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying shrinkage treatment, 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 substrate, thereby achieving high optical properties. Furthermore, by simultaneously increasing the orientation of PVA in advance, problems such as a decrease in orientation or dissolution of PVA when immersed in water in the subsequent dyeing and stretching steps can be prevented, thereby achieving high optical properties. Furthermore, when the PVA-based resin layer is immersed in a liquid, the disordering 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 a halide. This can improve the optical properties of an absorptive polarizing film obtained by immersing the laminate in a liquid through treatment steps such as a dyeing treatment and an underwater stretching treatment. Furthermore, the optical properties can be improved by shrinking the laminate in the width direction through drying shrinkage treatment.The obtained resin substrate / absorptive polarizing film laminate may be used as is (i.e., the resin substrate may be used as a protective layer for the absorptive polarizing film), or any suitable protective layer may be laminated depending on the purpose on the surface obtained by peeling the resin substrate from the resin substrate / absorptive polarizing film laminate, or on the surface opposite to the peeled surface. Details of such methods for producing absorptive polarizing films are described in, for example, JP 2012-73580 A and Japanese Patent No. 6470455 A. The entire disclosures of these publications are incorporated herein by reference.

[0039] The polarizing member (absorptive polarizing film) preferably has a crossed transmittance (Tc) of 0.5% or less, more preferably 0.1% or less, and even more preferably 0.05% or less. The polarizing member (absorptive polarizing film) has a single transmittance (Ts) of, for example, 41.0% to 45.0%, and preferably 42.0% or more. The polarizing member (absorptive polarizing film) has a degree of polarization (P) of, for example, 99.0% to 99.997%, and preferably 99.9% or more.

[0040] The crossed transmittance, single transmittance, and degree of polarization can be measured, for example, using an ultraviolet-visible spectrophotometer. The degree of polarization P can be calculated from the obtained Tp and Tc by measuring the single transmittance Ts, parallel transmittance Tp, and crossed transmittance Tc using an ultraviolet-visible spectrophotometer, using the following formula. Note that Ts, Tp, and Tc are Y values ​​measured using a 2-degree visual field (C light source) according to JIS Z 8701 and corrected for luminosity. Polarization degree P(%)={(Tp-Tc) / (Tp+Tc)} 1 / 2 ×100

[0041] The protective layer 13b that can be included in the polarizing member 13 can be made of, for example, any appropriate film. Examples of materials that can be used as the main component of the film that makes up the protective layer include cellulose-based resins such as triacetyl cellulose (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, polysulfone-based, polystyrene-based, cycloolefin-based resins such as polynorbornene, polyolefin-based, (meth)acrylic, and acetate-based resins. Here, (meth)acrylic refers to acrylic and / or methacrylic.

[0042] The thickness of the protective layer 13b is preferably 5 μm to 80 μm, more preferably 8 μm to 60 μm, and even more preferably 10 μm to 50 μm.

[0043] The first retardation member 21 includes at least a first λ / 4 member 20. In the example shown in FIG. 2, the first retardation member 21 includes, in addition to the first λ / 4 member 20, another retardation layer 23. The another retardation layer 23 is formed, for example, by a member whose refractive index characteristics can exhibit the relationship nz>nx=ny (a so-called positive C plate). The first retardation member 21 has a layered structure of the first λ / 4 member 20 and the another retardation layer 23. The first λ / 4 member 20 and the another retardation layer 23 are layered via an adhesive layer 50. In this case, the first retardation member 21 includes the first λ / 4 member 20, the adhesive layer 50, and the another retardation layer 23.

[0044] The first λ / 4 member 20 is disposed adjacent to the polarizing film 13a. For example, the first λ / 4 member 20 can function as a protective layer for the polarizing film 13a. In this specification, "adjacent" includes not only being directly adjacent, but also being adjacent via an adhesive layer. Examples of the adhesive layer include an adhesive layer formed from an adhesive and a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive.

[0045] The first λ / 4 member 20 may be formed of any appropriate material that can satisfy the above characteristics. Preferably, the first λ / 4 member 20 has a moisture permeability of, for example, 200 g / m at 40° C. and 92% RH. 2 24h or less, preferably 150g / m 2 24 hours or less, preferably 100 g / m 2 24 hours or less. By disposing such a first λ / 4 member 20 adjacent to the polarizing film 13a, the optical laminate 1 can have extremely excellent moisture resistance. Such a first λ / 4 member 20 can function as a blocking layer that blocks the movement of iodine contained in the polarizing film 13a. Specifically, it can prevent iodine from passing through a member disposed adjacent to the polarizing film 13a and causing discoloration of the polarizing film 13a. On the other hand, the moisture permeability of the first λ / 4 member 20 at 40°C and 92% RH is, for example, 50 g / m 2 - 24 hours or more.

[0046] The first λ / 4 member 20 can be made of any appropriate material as long as it satisfies the above-mentioned characteristics. Specifically, the first λ / 4 member 20 may be made of a resin film (typically, a stretched resin film) or a liquid crystal alignment solidified layer. Preferably, the first λ / 4 member 20 is made of a resin film. In this case, the thickness of the first λ / 4 member 20 is, for example, 10 μm to 100 μm, preferably 10 μm to 70 μm, more preferably 20 μm to 60 μm, and even more preferably 30 μm to 50 μm. The first λ / 4 member can be made of a resin film, and the first λ / 4 member 20 made of a resin film satisfies the above-mentioned moisture permeability requirement and can function well as an iodine blocking layer.

[0047] Examples of resins contained in the 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 alone or in combination. Examples of methods for combining include blending and copolymerization. When the retardation member exhibits reverse 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.

[0048] Any suitable polycarbonate-based resin can be used as the polycarbonate-based resin. For example, the polycarbonate-based resin contains structural units derived from a fluorene-based dihydroxy compound, structural units derived from an isosorbide-based dihydroxy compound, and structural units derived from at least one dihydroxy compound selected from the group consisting of alicyclic diols, alicyclic dimethanols, di-, tri-, or polyethylene glycols, and alkylene glycols or spiroglycols. Preferably, the polycarbonate-based resin contains structural units derived from a fluorene-based dihydroxy compound, structural units derived from an isosorbide-based dihydroxy compound, structural units derived from an alicyclic dimethanol, and / or structural units derived from di-, tri-, or polyethylene glycol; more preferably, it contains structural units derived from a fluorene-based dihydroxy compound, structural units derived from an isosorbide-based dihydroxy compound, and structural units derived from di-, tri-, or polyethylene glycol. The polycarbonate-based resin may contain structural units derived from other dihydroxy compounds as needed. Details of polycarbonate-based resins that can be suitably used for phase difference members and methods for forming phase difference members are described, for example, in JP-A-2014-10291, JP-A-2014-26266, JP-A-2015-212816, JP-A-2015-212817, and JP-A-2015-212818, and the descriptions in these publications are incorporated herein by reference.

[0049] When the other retardation layer 23 is composed of a positive C plate, it is preferable that the other retardation layer (positive C plate) 23 is located in front of the first λ / 4 member 20 in the first retardation member 21, as shown in FIG. 2, from the viewpoint of visibility.

[0050] The thickness direction retardation Rth(550) of the positive C plate is preferably -50 nm to -300 nm, more preferably -60 nm to -250 nm, even more preferably -65 nm to -200 nm, and particularly preferably -70 nm to -150 nm. "nx=ny" includes not only the case where nx and ny are strictly equal, but also the case where nx and ny are substantially equal. The in-plane retardation Re(550) of the positive C plate is, for example, less than 10 nm.

[0051] The positive C plate can be formed from any suitable material, but is preferably composed of a film containing a liquid crystal material fixed in homeotropic alignment. The liquid crystal material (liquid crystal compound) that can be homeotropically aligned may be a liquid crystal monomer or a liquid crystal polymer. Specific examples of such liquid crystal compounds and methods for forming a positive C plate include the liquid crystal compounds and methods for forming the retardation layer described in

[0020] to

[0028] of JP 2002-333642 A. In this case, the thickness of the positive C plate is preferably 0.5 μm to 5 μm.

[0052] The adhesive layer 50 can be formed of any appropriate adhesive. For example, the adhesive irreversibly changes state from liquid to solid during the process of forming the adhesive layer, has fluidity when applied, and has the property of being hardened by a hardening treatment (for example, irradiation with active energy rays, heating). A curable adhesive is preferably used as the adhesive. Specifically, the adhesive layer 50 is preferably a cured layer of resin. An ultraviolet-curable adhesive is preferably used as the hardening adhesive.

[0053] The ultraviolet-curable adhesive contains a curable monomer such as a compound having a (meth)acryloyl group or a compound having a vinyl group. Preferably, a compound having a (meth)acryloyl group is used. Here, the (meth)acryloyl group refers to an acryloyl group and / or a methacryloyl group.

[0054] It is preferable that there are substantially no air bubbles in the adhesive layer 50. Specifically, the number of air bubbles present in the adhesive layer 50 is preferably 10 bubbles / m 2 More preferably, 7 particles / m 2 More preferably, 5 particles / m or less. 2 It is particularly preferable that the number of particles is 3 or less per m 2 or less, and most preferably 1 particle / m 2 The following is the result.

[0055] The thickness of the adhesive layer 50 is preferably 2.0 μm or more. Such a thickness allows for a satisfactory number of bubbles to be achieved, thereby achieving excellent visibility in the display system. Specifically, in the display system, bubbles present in the optical laminate may enlarge and be visually perceived as defects. Therefore, the absence of bubbles in the optical laminate can significantly contribute to improved visibility. While a thick adhesive layer tends to reduce moisture resistance, as described above, the first λ / 4 member 20 can function sufficiently as an iodine blocking layer, allowing an adhesive layer 50 of 2.0 μm or more to be provided while maintaining moisture resistance. The thickness of the adhesive layer 50 is preferably 3.0 μm or less, and more preferably 2.5 μm or less.

[0056] A first adhesive layer 41 is provided between the polarizing member 13 and the first retardation member 21. The first adhesive layer 41 is in direct contact with the polarizing film 13a of the polarizing member 13 and the first λ / 4 member 20 of the first retardation member 21.

[0057] The optical laminate 1 further includes a protective member 30 disposed in front of the first retardation member 21. The protective member 30 is laminated to the first retardation member 21 via a second pressure-sensitive adhesive layer 42. In the display system 2, a space is typically formed between the optical laminate 1 and the first lens unit 16. The protective member 30 can be located on the outermost surface of the optical laminate 1, and can protect components disposed behind it (below in FIG. 2 ).

[0058] The protective member 30 typically includes a substrate. The thickness of the substrate is preferably 5 μm to 80 μm, more preferably 10 μm to 50 μm, and even more preferably 15 μm to 40 μm. The substrate can be made of any appropriate film. Examples of materials that form the main component of the film that constitutes the substrate include cellulose-based resins such as triacetyl cellulose (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, polysulfone-based, polystyrene-based, cycloolefin-based resins such as polynorbornene, polyolefin-based, (meth)acrylic-based, and acetate-based resins.

[0059] The protective member 30 preferably has a substrate and a surface treatment layer formed on the substrate. The protective member 30 having the surface treatment layer can be disposed so that the surface treatment layer is located on the front side. Specifically, the surface treatment layer can be located on the outermost surface of the optical laminate 1. The surface treatment layer can have any appropriate function. For example, from the viewpoint of improving visibility, the surface treatment layer preferably has an anti-reflection function. The thickness of the surface treatment layer is preferably 0.5 μm to 10 μm, more preferably 1 μm to 7 μm, and even more preferably 2 μm to 5 μm.

[0060] The first pressure-sensitive adhesive layer 41 and the second pressure-sensitive adhesive layer 42 can each be composed of any appropriate pressure-sensitive adhesive. Specific examples include acrylic pressure-sensitive adhesives, rubber pressure-sensitive adhesives, silicone pressure-sensitive adhesives, polyester pressure-sensitive adhesives, urethane pressure-sensitive adhesives, epoxy pressure-sensitive adhesives, and polyether pressure-sensitive adhesives. Pressure-sensitive adhesives with desired properties can be prepared according to the intended purpose by adjusting the type, number, combination, and compounding ratio of monomers forming the base resin of the pressure-sensitive adhesive, as well as the amount of cross-linking agent, reaction temperature, reaction time, etc. The base resin of the pressure-sensitive adhesive may be used alone or in combination of two or more types. An acrylic resin is preferably used as the base resin. Specifically, the pressure-sensitive adhesive layer is preferably composed of an acrylic pressure-sensitive adhesive.

[0061] The thickness of each of the first pressure-sensitive adhesive layer 41 and the second pressure-sensitive adhesive layer 42 is preferably 3 μm or more and 25 μm or less, more preferably 20 μm or less, and may be 15 μm or less. A thin pressure-sensitive adhesive layer can have excellent smoothness.

[0062] The optical laminate preferably has an ellipticity of 0.90 or more, more preferably 0.93 or more, and even more preferably 0.95 or more, for transmitted light at a wavelength of 590 nm, measured at a polar angle of 30° and an azimuth angle of 0° to 360°. By using an optical laminate exhibiting such an ellipticity, a display system with excellent display characteristics can be obtained. Such an optical laminate can reduce the so-called ghost phenomenon, in which overlapping displayed images are perceived, in the display system. It can also suppress light leakage and contribute to higher resolution. The ellipticity of the optical laminate for transmitted light at a wavelength of 590 nm, measured at a polar angle of 30° and an azimuth angle of 0° to 360°, is, for example, 0.99 or less. Here, "ellipticity" refers to the ratio of the minor axis to the major axis of circularly polarized light, and is an absolute value. For example, the ellipticity of perfectly circularly polarized light is 1, and the ellipticity of perfectly linearly polarized light is 0.

[0063] In one embodiment, the ellipticity of transmitted light of a predetermined wavelength measured at a polar angle of 30° and an azimuth angle of 0° to 360° is the ellipticity measured at every 11.25° azimuth angle in the range of 0° to 360° for light of the predetermined wavelength incident from the polarizing member side at a polar angle of 30° and emitted at a polar angle of 30°. Therefore, "the ellipticity is X or more" measured at an azimuth angle of 0° to 360° means that the minimum value of the 32 measured values ​​obtained is X.

[0064] The optical laminate preferably has an ellipticity of 0.94 or more, more preferably 0.95 or more, and even more preferably 0.96 or more, for transmitted light at a wavelength of 590 nm measured at a polar angle of 0° (front direction). Within these ranges, an optical laminate can be obtained that exhibits significant effects in reducing ghosting, suppressing light leakage, and achieving high definition. The ellipticity of the optical laminate for transmitted light at a wavelength of 590 nm measured at a polar angle of 0° (front direction) is, for example, 0.99 or less.

[0065] The ellipticity is measured, for example, using a Mueller matrix polarimeter (manufactured by Axometrics, product name "Axoscan") at 23°C by irradiating light of a predetermined wavelength (e.g., 590 nm) onto the polarizing member side of the optical laminate.

[0066] The reflectance Y value of the optical laminate is, for example, 0.30% to 0.70%, and preferably 0.40% or less. [Example]

[0067] The present invention will be specifically described below using examples, but the present invention is not limited to these examples. The test and evaluation methods used in the examples are as follows. The term "parts" means "parts by weight" unless otherwise specified, and the term "%" means "% by weight" unless otherwise specified.

[0068] (1) Thickness Thicknesses of 10 μm or less were measured using a scanning electron microscope (manufactured by JEOL Ltd., product name "JSM-7100F"), and thicknesses of more than 10 μm were measured using a digital micrometer (manufactured by Anritsu Corporation, product name "KC-351C"). (2) Phase difference value The retardation value at a predetermined wavelength was measured at 23° C. using a retardation / ellipsoidal polarization measuring device (manufactured by Oji Scientific Instruments, product names "KOBRA-HBR" and "KOBRA-HBPR"). (3) Single transmittance and polarization degree of polarizing element The polarizing element's single transmittance Ts, parallel transmittance Tp, and crossed transmittance Tc were measured using a spectrophotometer (Otsuka Electronics Co., Ltd., "LPF-200"). These Ts, Tp, and Tc are Y values ​​measured using a 2-degree visual field (C light source) according to JIS Z 8701 and corrected for visibility. The degree of polarization of the polarizing element was calculated from the obtained Tp and Tc using the following formula. Degree of polarization (%)={(Tp-Tc) / (Tp+Tc)} 1 / 2 ×100 (4) Moisture permeability The moisture permeability was determined by the cup method (JIS Z 0208). (5) Number of bubbles in the adhesive layer Test pieces measuring 240 mm x 400 mm were cut out from the retardation members of Production Examples 2-1 and 2-2 below. The test pieces were subjected to reflective automated optical inspection (AOI) using an automated optical inspection device. The defect size for each bubble was calculated by dividing the length by two (long side + short side), and bubbles with a defect size of 30 μm or more were counted to calculate the number of bubbles per unit area.

[0069] [Manufacturing Example 1] (Fabrication of an absorption polarizing film) A long, amorphous isophthalic copolymerized polyethylene terephthalate film (thickness: 100 μm) having a Tg of about 75° C. was used as the thermoplastic resin substrate, and one side of the resin substrate was subjected to a corona treatment. A PVA aqueous solution (coating liquid) was prepared by dissolving 100 parts by weight of a PVA-based resin made by mixing polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Mitsubishi Chemical Corporation, trade name "Gohsenex Z410") in a 9:1 ratio, to which 13 parts by weight of potassium iodide was added, in water. The above PVA aqueous solution was applied to the corona treated surface of the resin substrate and dried at 60° C. to form a PVA resin layer with a thickness of 13 μm, thereby producing a laminate. The resulting laminate was uniaxially stretched 2.4 times in the machine direction (longitudinal direction) in an oven at 130°C (auxiliary in-air stretching treatment). Next, the laminate was immersed in an insolubilizing bath (a boric acid aqueous solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40°C for 30 seconds (insolubilizing treatment). Next, the laminate was immersed in a dye bath (an aqueous iodine solution obtained by mixing iodine and potassium iodide in a weight ratio of 1:7 with 100 parts by weight of water) at a liquid temperature of 30°C for 60 seconds while adjusting the concentration so that the single transmittance (Ts) of the absorptive polarizing film finally obtained would have the desired value (dyeing treatment). Next, the laminate was immersed in a crosslinking bath (a boric acid aqueous solution obtained by blending 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40°C for 30 seconds (crosslinking treatment). The laminate was then immersed in a boric acid aqueous solution (boric acid concentration 4 wt %, potassium iodide concentration 5 wt %) at a liquid temperature of 70°C and uniaxially stretched in the longitudinal direction (longitudinal direction) between rolls with different peripheral speeds to a total stretch ratio of 5.5 times (underwater stretching treatment). Thereafter, the laminate was immersed in a cleaning bath (aqueous solution obtained by mixing 4 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 20° C. (cleaning treatment). The laminate was then dried in an oven maintained at approximately 90°C and brought into contact with a SUS heated roll whose surface temperature was maintained at approximately 75°C (drying shrinkage treatment). The shrinkage rate of the laminate in the width direction due to the drying shrinkage treatment was 5.2%. In this way, an absorptive polarizing film having a thickness of about 5 μm was formed on the resin substrate.

[0070] (Preparation of polarizing member) A 40 μm-thick acrylic film having a lactone ring structure was attached as a protective layer to the surface of the obtained absorptive polarizing film (the surface opposite to the resin substrate) via a UV-curable adhesive. Specifically, the curable adhesive was applied to a thickness of 2 μm, and the films were attached using a roller. The adhesive was then cured by irradiating it with UV light from the acrylic film side. The resin substrate was then peeled off. In this way, a polarizing element having an acrylic film / absorptive polarizing film configuration was obtained. The single transmittance (Ts) of the obtained polarizing element was 43.4%, and the polarization degree was 99.993%.

[0071] (protective layer with hard coat layer) The following hard coat layer forming material was applied to a TAC film (thickness 25 μm) and heated at 90°C for 1 minute, and then the coated layer after heating was irradiated with a high-pressure mercury lamp at an integrated light intensity of 300 mJ / cm 2 The coating layer was cured by irradiating it with ultraviolet light at 1000 kJ / cm, thereby obtaining a TAC film having a hard coating layer with a thickness of 7 μm.

[0072] (Hard Coat Layer Forming Material) A hard coat layer-forming material was prepared by mixing 50 parts of a urethane acrylic oligomer (manufactured by Shin-Nakamura Chemical Co., Ltd., "NK Oligo UA-53H"), 30 parts of a multifunctional acrylate whose main component is pentaerythritol triacrylate (manufactured by Osaka Organic Chemical Industry Ltd., trade name "Viscoat #300"), 20 parts of 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Ltd.), 1 part of a leveling agent (manufactured by DIC Corporation, "GRANDIC PC4100"), and 3 parts of a photopolymerization initiator (manufactured by Ciba Japan, "Irgacure 907") and diluting with methyl isobutyl ketone to a solids concentration of 50%.

[0073] [Manufacturing Example 2-1] (Fabrication of λ / 4 components) Polymerization was carried out using a batch polymerization apparatus consisting of two vertical reactors equipped with stirring blades and reflux condensers controlled at 100° C. The polymerization mixture contained 29.60 parts by mass (0.046 mol) of bis[9-(2-phenoxycarbonylethyl)fluoren-9-yl]methane, 29.21 parts by mass (0.200 mol) of isosorbide (ISB), 42.28 parts by mass (0.139 mol) of spiroglycol (SPG), 63.77 parts by mass (0.298 mol) of diphenyl carbonate (DPC), and 1.19 × 10 calcium acetate monohydrate as a catalyst. -2 Part of mass (6.78×10 -5(mol) was charged. After purging the reactor with nitrogen under reduced pressure, heating was performed using a heat transfer medium. Stirring was initiated when the internal temperature reached 100°C. Forty minutes after the start of the temperature increase, the internal temperature reached 220°C. This temperature was maintained while simultaneously reducing the pressure. 90 minutes after reaching 220°C, the pressure was reduced to 13.3 kPa. Phenol vapor by-produced during the polymerization reaction was introduced into a reflux condenser at 100°C, and the small amount of monomer components contained in the phenol vapor was returned to the reactor. Uncondensed phenol vapor was collected by introducing nitrogen into the first reactor and temporarily restoring the pressure to atmospheric pressure. The oligomerized reaction liquid in the first reactor was then transferred to the second reactor. Next, heating and depressurization of the second reactor were initiated, and the internal temperature reached 240°C and the pressure reached 0.2 kPa in 50 minutes. The polymerization was then allowed to proceed until the specified stirring power was reached. When the predetermined power was reached, nitrogen was introduced into the reactor to restore pressure, and the polyester carbonate resin produced was extruded into water, and the strands were cut to obtain pellets.

[0074] The resulting polyester carbonate resin pellets were vacuum-dried at 80°C for 5 hours, and then a 135 μm-thick long resin film was produced using a film-forming device equipped with a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder temperature setting: 250°C), a T-die (width: 200 mm, temperature setting: 250°C), a chill roll (temperature setting: 120-130°C), and a winder. The resulting long resin film was stretched in the width direction at a stretching temperature of 143°C and a stretch ratio of 2.8 to obtain a 47 μm-thick stretched film. The resulting stretched film had an Re(550) of 143 nm, an Re(450) / Re(550) of 0.86, and an Nz coefficient of 1.12. The moisture permeability of the resulting stretched film at 40°C and 92% RH was 79.61 g / m 2 -It was 24 hours.

[0075] (Positive C-plate formation) A liquid crystal coating solution was prepared by dissolving 20 parts by weight of a side-chain liquid crystal polymer represented by the following chemical formula (1) (the numbers 65 and 35 in the formula indicate the mole percentage of the monomer unit, and are conveniently represented as a block polymer: weight-average molecular weight 5000), 80 parts by weight of a polymerizable liquid crystal exhibiting a nematic liquid crystal phase (manufactured by BASF: trade name Paliocolor LC242), and 5 parts by weight of a photopolymerization initiator (manufactured by Ciba Specialty Chemicals: trade name Irgacure 907) in 200 parts by weight of cyclopentanone. The coating solution was then applied to a PET substrate that had been subjected to a vertical alignment treatment using a bar coater, and the liquid crystal was aligned by heating and drying at 80°C for 4 minutes. The liquid crystal layer was irradiated with ultraviolet light to harden the liquid crystal layer, resulting in a moisture permeability of 100 g / m at 40°C and 92% RH. 2 After more than 24 h, a positive C-plate with a thickness of 4 μm and Rth(550) of -80 nm was formed on the substrate. [ka]

[0076] (Production of first phase difference member) The following adhesive was applied to each of the λ / 4 member and the positive C plate, and the applied adhesives were superimposed on each other using a roll-to-roll method while being transported by rolls to obtain a first retardation member. The adhesive was applied so that the thickness of the adhesive layer obtained by curing the adhesive would be 2.3 μm. The number of bubbles in the resulting adhesive layer with a thickness of 2.3 μm was 0.4 bubbles / m 2 It was.

[0077] (Preparation of adhesive) An adhesive was prepared by mixing 62 parts by weight of hydroxyethyl acrylamide (manufactured by Kojin Co., Ltd., trade name "HEAA"), 25 parts by weight of acryloylmorpholine (manufactured by Kojin Co., Ltd., 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.

[0078] [Production Example 2-2] (Production of first phase difference member) A first retardation member was obtained in the same manner as in Production Example 2-1, except that the adhesive was applied so that the thickness of the adhesive layer obtained by curing the adhesive would be 1.0 μm. The number of bubbles in the resulting adhesive layer with a thickness of 1.0 μm was 12 / m 2 It was.

[0079] [Manufacturing Example 3] (Production of protective material) The hard coat layer-forming material described below was applied to an acrylic film (thickness: 40 μm) having a lactone ring structure and heated at 90°C for 1 minute. After heating, the applied layer was irradiated with a high-pressure mercury lamp at an integrated light intensity of 300 mJ / cm. 2 The coating layer was cured by irradiation with ultraviolet light of 1000 kJ / cm, thereby producing an acrylic film (thickness: 44 μm) on which a hard coat layer having a thickness of 4 μm was formed. Next, the following coating solution A for forming an antireflection layer was applied onto the hard coat layer using a wire bar, and the applied coating solution was heated at 80°C for 1 minute and dried to form a coating film. The dried coating film was then irradiated with a high-pressure mercury lamp at an integrated light intensity of 300 mJ / cm. 2 The coating was cured by irradiating it with ultraviolet light of 1,000 ohms, to form an antireflection layer A having a thickness of 140 nm. Next, the following coating solution B for forming an antireflection layer was applied onto the antireflection layer A using a wire bar, and the applied coating solution was heated at 80°C for 1 minute and dried to form a coating film. The dried coating film was irradiated with an integrated light dose of 300 mJ / cm using a high-pressure mercury lamp. 2 The coating was cured by irradiating it with ultraviolet light of 1000 kJ / cm 2 , thereby forming an antireflection layer B having a thickness of 105 nm. In this way, a protective member (thickness: 44 μm) was obtained.

[0080] (Hard Coat Layer Forming Material) A hard coat layer-forming material was prepared by mixing 50 parts of a urethane acrylic oligomer (manufactured by Shin-Nakamura Chemical Co., Ltd., "NK Oligo UA-53H"), 30 parts of a multifunctional acrylate whose main component is pentaerythritol triacrylate (manufactured by Osaka Organic Chemical Industry Ltd., trade name "Viscoat #300"), 20 parts of 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Ltd.), 1 part of a leveling agent (manufactured by DIC Corporation, "GRANDIC PC4100"), and 3 parts of a photopolymerization initiator (manufactured by Ciba Japan, "Irgacure 907") and diluting with methyl isobutyl ketone to a solids concentration of 50%.

[0081] (Anti-reflection layer forming coating solution A) 100 parts by weight of a multifunctional acrylate (manufactured by Arakawa Chemical Industries, Ltd., trade name "Opstar KZ6728", solid content 20% by weight), 3 parts by weight of a leveling agent (manufactured by DIC Corporation, "GRANDIC PC4100"), and 3 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name "OMNIRAD907", solid content 100% by weight) were mixed. The mixture was diluted with butyl acetate as a dilution solvent to a solid content of 12% by weight, and the mixture was stirred to prepare Coating Solution A for forming an antireflection layer.

[0082] (Anti-reflection layer forming coating solution B) 100 parts by weight of a polyfunctional acrylate containing pentaerythritol triacrylate as the main component (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "Viscoat #300", solid content 100 wt%), 150 parts by weight of hollow nanosilica particles (manufactured by JGC Catalysts and Chemicals Industries, Ltd., trade name "Sururia 5320", solid content 20 wt%, weight average particle diameter 75 nm), 50 parts by weight of solid nanosilica particles (manufactured by Nissan Chemical Industries, Ltd., trade name "MEK-2140Z-AC", solid content 30 wt%, weight average particle diameter 10 nm), 12 parts by weight of a fluorine-containing additive (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KY-1203", solid content 20 wt%), and 3 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name "OMNIRAD907", solid content 100 wt%) were mixed. To this mixture, a mixed solvent of TBA (tertiary butyl alcohol), MIBK (methyl isobutyl ketone), and PMA (propylene glycol monomethyl ether acetate) in a weight ratio of 60:25:15 was added as a dilution solvent to make the total solid content 4% by weight, and the mixture was stirred to prepare coating solution B for forming an anti-reflection layer.

[0083] [Manufacturing Example 4] (Formation of adhesive layer) A four-neck flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser was charged with 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. Furthermore, 0.3 parts by weight of dibenzoyl peroxide as a polymerization initiator was charged along with ethyl acetate for 100 parts by weight of this monomer mixture. Nitrogen gas was introduced into the flask with gentle stirring to replace the atmosphere with nitrogen. The temperature in the flask was maintained at 60°C, and the polymerization reaction was carried out for 7 hours. Ethyl acetate was then added to the resulting reaction solution to adjust the solids concentration to 30% by weight, producing an acrylic polymer solution with a weight-average molecular weight (Mw) of 2.2 million. An acrylic adhesive was prepared by blending 0.6 parts by weight of a trimethylolpropane / tolylene diisocyanate adduct (trade name: Coronate L, manufactured by Tosoh Corporation) and 0.075 parts by weight of a silane coupling agent (trade name: KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) with 100 parts by weight of the solid content of the obtained acrylic polymer solution. The obtained acrylic pressure-sensitive adhesive was coated on a substrate film, and the resulting coating film on the substrate film was dried in an oven to form pressure-sensitive adhesive layers with thicknesses of 12 μm and 15 μm.

[0084] [Example 1] The first retardation member obtained in Production Example 2-1 was attached to the absorptive polarizing film side of the polarizing member obtained in Production Example 1 via the 15 μm-thick pressure-sensitive adhesive layer obtained in Production Example 4. At this time, the attachment was performed so that the angle between the absorption axis of the polarizing member and the slow axis of the λ / 4 member of the first retardation member was 45°. The attachment was also performed so that the λ / 4 member of the first retardation member was positioned on the polarizing member side. Next, the protective member obtained in Production Example 3 was attached to the positive C plate side of the first retardation member via the 12 μm-thick pressure-sensitive adhesive layer obtained in Production Example 4. At this time, the acrylic film of the protective member was attached so as to be positioned on the polarizing member side. Next, a release liner having a 20 μm thick pressure-sensitive adhesive layer formed thereon was attached to the protective layer side of the polarizing member. In this way, an optical laminate was obtained.

[0085] [Comparative Example 1] An optical laminate was obtained in the same manner as in Example 1, except that the first retardation member obtained in Production Example 2-2 was used as the first retardation member.

[0086] Comparative Example 2 An optical laminate was obtained in the same manner as in Comparative Example 1, except that when the polarizing element and the first phase difference element were bonded together, the positive C plate of the first phase difference element was positioned closer to the polarizing element than the λ / 4 element.

[0087] Comparative Example 3 An optical laminate was obtained in the same manner as in Example 1, except that when the polarizing element and the first phase difference element were bonded together, the positive C plate of the first phase difference element was positioned closer to the polarizing element than the λ / 4 element.

[0088] <Evaluation> The following evaluations were carried out for each of the Examples and Comparative Examples. The evaluation results are summarized in Table 1 together with the number of bubbles present in the adhesive layer of the first retardation member.

[0089] 1. Moisture resistance The obtained optical laminate was attached to an alkali-free glass plate and then placed in an environment of 65°C and 90% RH for 120 hours (humidification test). The transmittance Ts and degree of polarization of the optical laminate before and after the humidification test were measured using a spectrophotometer (Otsuka Electronics Co., Ltd., "LPF-200"), and the change in transmittance ΔTs (ΔTs = Ts after humidification test - Ts before humidification test) and the change in polarization ΔP (ΔP = P before humidification test - P after humidification test) were calculated.

[0090] 2. Ellipticity Using a Mueller matrix polarimeter (manufactured by Axometrics, product name "Axoscan"), light of a specified wavelength (590 nm) was incident on the polarizing element side of the optical laminate at 23°C, and the ellipticity of the light emitted from the first phase difference element was measured. The incident angle and the outgoing angle were set to a polar angle of 30°, and the ellipticity was measured at azimuth angles of 11.25° in the range of azimuth angles from 0° to 360°, and the average value of 32 measured values ​​was calculated. The ellipticity was also measured with the incident angle and the exit angle set as a polar angle of 0°.

[0091] 3. Reflectance Y value The obtained optical laminate was attached to a black plate, and then the regular reflectance was measured using an ultraviolet-visible-near-infrared spectrophotometer (Hitachi High-Tech Science Corporation, "UH4150") to calculate the Y value. Specifically, using a 2-degree field of view (C light source) according to JIS Z 8701, the regular reflectance was measured at 10 nm intervals at a measurement wavelength range of 300 nm to 800 nm, and the Y value was calculated.

[0092] [Table 1]

[0093] The optical laminate of Example 1 has excellent moisture resistance, and the display system described above can achieve excellent visibility using the optical laminate of Example 1. In Comparative Examples 2 and 3, it is believed that iodine contained in the absorptive polarizing film was absorbed into the adhesive layer after passing through the positive C plate of the first retardation member.

[0094] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the configurations shown in the above-described embodiment can be replaced with configurations that are substantially the same as those shown in the above-described embodiment, that have the same effects, or that can achieve the same purpose. [Industrial Applicability]

[0095] A display system according to an embodiment of the present invention can be used in a display such as VR goggles, for example. [Explanation of symbols]

[0096] 1 optical laminate, 2 display system, 12 display element, 12a display surface, 13 polarizing member, 13a polarizing film, 13b protective layer, 14 reflective portion (reflective polarizing member), 16 first lens portion, 18 half mirror, 20 first λ / 4 member, 21 first retardation member, 22 second λ / 4 member, 23 other retardation layer, 24 second lens portion, 30 protective member, 41 first adhesive layer, 42 second adhesive layer, 50 adhesive layer.

Claims

1. A step of passing the light representing the image emitted through the polarizing member through a first λ / 4 member; a step of causing the light that has passed through the first λ / 4 member to pass through a half mirror and a first lens unit; a step of passing the light that has passed through the half mirror and the first lens portion through a second λ / 4 member; A step of reflecting the light that has passed through the second λ / 4 member toward the half mirror by a reflective polarizing member; allowing the light reflected by the reflective polarizing element and the half mirror to pass through the reflective polarizing element by the second λ / 4 element; An optical laminate used in a display method, The polarizing member, the first λ / 4 member, an adhesive layer, and another retardation layer are included in this order, the polarizing member includes a polarizing film containing iodine and a protective layer, The first λ / 4 member is disposed adjacent to the polarizing film and has a moisture permeability of 100 g / m at 40° C. and 92% RH. ２ - 24 hours or less, The thickness of the adhesive layer is 2.0 μm or more. Optical laminate.

2. The optical laminate according to claim 1 , wherein the first λ / 4 member is made of a resin film.

3. The optical laminate according to claim 1 , wherein the first λ / 4 member has a thickness of 30 μm or more.

4. The optical laminate according to claim 1 , wherein the adhesive layer is a cured resin layer.

5. The optical laminate according to claim 1 , wherein a pressure-sensitive adhesive layer having a thickness of 20 μm or less is provided between the polarizing film and the first λ / 4 member.

6. The number of bubbles present in the adhesive layer is 10 / m ２ The optical laminate according to claim 1, wherein:

7. 1. A display system for displaying an image to a user, 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 disposed on an optical path between the display element and the reflective polarizing member; a half mirror disposed between the display element and the first lens portion, the half mirror transmitting light emitted from the display element and reflecting light reflected by the reflective polarizing element toward the reflective polarizing element; a first λ / 4 member disposed on an optical path between the display element and the half mirror; a second λ / 4 member disposed on an optical path between the half mirror and the reflective polarizing member, an optical laminate having the polarizing member, the first λ / 4 member, an adhesive layer, and another retardation layer in this order; the polarizing member includes a polarizing film containing iodine and a protective layer, The first λ / 4 member is disposed adjacent to the polarizing film and has a moisture permeability of 100 g / m at 40° C. and 92% RH. ２ - 24 hours or less, The thickness of the adhesive layer is 2.0 μm or more. Display system.

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