Optical laminate set

Abstract

Provided is an optical laminate by which it is possible to realize a display system having stable optical characteristics even in a harsh environment.　An optical laminate set according to an embodiment of the present invention is a set of a first optical laminate and a second optical laminate, the optical laminate set satisfying the relational expression of |XD-XL| ≤ 3 nm regarding a change (phase difference change XD) in the in-plane phase difference (590) of the first optical laminate when left in a 65°C / 90% environment for 500 hours and a change (phase difference change XL) in the in-plane phase difference (590) of the second optical laminate when left in a 65°C / 90% environment for 500 hours.

Description

Optical laminate set

[0001] The present invention relates to an optical laminate set.

[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 polarizing components and phase difference components are generally used to realize image display and improve image display performance (see, for example, Patent Document 1).

[0003] In recent years, new applications of image display devices have been developed. For example, goggles with displays (VR goggles) for realizing virtual reality (VR) have begun to be commercialized. Since the use of VR goggles in various situations is being considered, higher requirements are placed on the optical laminates applied to conventional image display devices in terms of stability in harsh environments such as high temperature and / or high humidity environments.

[0004] Japanese Patent Application Laid-Open No. 2021-103286

[0005] A main object of the present invention is to provide an optical laminate that enables a display system with stable optical properties even under harsh environments.

[0006] 1. A set of optical laminates according to an embodiment of the present invention is a set of a first optical laminate and a second optical laminate, wherein a change in in-plane retardation (590) of the first optical laminate when placed in a 65°C / 90% humidity environment for 500 hours (retardation change XD) and a change in in-plane retardation (590) of the second optical laminate when placed in a 65°C / 90% humidity environment for 500 hours (retardation change XL) satisfy the relationship |XD-XL|≦3 nm. 2. In the set of optical laminates described in 1 above, the first optical laminate may include three or more optical members. 3. In the set of optical laminates described in 2 above, the number of optical members in the second optical laminate may be smaller than the number of optical members in the first optical laminate. 4. In the set of optical laminates described in any one of 1 to 3 above, the first optical laminate and the second optical laminate may include a pressure-sensitive adhesive layer. 5. In the set of optical laminates described in 4 above, the number of pressure-sensitive adhesive layers in the first optical laminate may be greater than the number of pressure-sensitive adhesive layers in the second optical laminate. 6. In the set of optical laminates described in 4 or 5 above, the first optical laminate and the second optical laminate may comprise two or more types of pressure-sensitive adhesive layers. 7. In the set of optical laminates described in any of 4 to 6 above, the first optical laminate may comprise two or more pressure-sensitive adhesive layers, and at least two of the pressure-sensitive adhesive layers may have different thicknesses. 8. In the set of optical laminates described in any of 4 to 6 above, the second optical laminate may comprise two or more pressure-sensitive adhesive layers, and at least two of the pressure-sensitive adhesive layers may have different thicknesses. 9. In the set of optical laminates described in 7 above, the second optical laminate may comprise two or more pressure-sensitive adhesive layers, and at least two of the pressure-sensitive adhesive layers may have different thicknesses. 10. A method for controlling an in-plane retardation change X of an optical laminate under a high-humidity environment according to an embodiment of the present invention is a method for controlling an in-plane retardation change X of an optical laminate under a high-humidity environment, the method including adjusting the type and / or thickness of the pressure-sensitive adhesive layer.

[0007] According to an embodiment of the present invention, it is possible to provide an optical laminate that enables a display system with stable optical properties even in a harsh environment.

[0008] 1 is a schematic diagram showing a general configuration of a display system including an optical stack according to one embodiment of the present invention; 2 is a schematic cross-sectional view of a first optical stack according to one embodiment of the present invention; 3 is a schematic cross-sectional view of a second optical stack according to one embodiment of the present invention; 4 is a schematic cross-sectional view of a second optical stack according to one embodiment of the present invention;

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. Furthermore, in order to clarify the description, the drawings may show the width, thickness, shape, etc. of each part more schematically than in the embodiments, but these are merely examples and are not intended to limit the interpretation of the present invention. Furthermore, in this specification, the term "to" indicating a numerical range includes the upper and lower limits, and "(meth)acrylic" means "acrylic and / or methacrylic."

[0010] (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 maximum (i.e., the slow axis direction), "ny" is the refractive index in the in-plane direction perpendicular to the slow axis (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 having a wavelength of λ nm at 23°C. For example, "Re(550)" is the in-plane retardation measured with light having a wavelength of 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) Thickness Direction Retardation (Rth) "Rth(λ)" is the retardation in the thickness direction measured with light having a wavelength of λ nm at 23°C. For example, "Rth(550)" refers to the retardation in the thickness direction measured with light having a wavelength of 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 in this specification, they include both clockwise and counterclockwise angles with respect to a reference direction. Thus, for example, "45°" means 45° clockwise or counterclockwise. Furthermore, in this specification, "substantially parallel" includes angles within a range of 0°±10°, such as 0°±5°, preferably 0°±3°, and more preferably 0°±1°. "Substantially perpendicular" includes angles within a range of 90°±10°, such as 90°±5°, preferably 90°±3°, and more preferably 90°±1°.

[0011] A. Set of Optical Laminates A set of optical laminates according to an embodiment of the present invention is a set of a first optical laminate and a second optical laminate, in which the change in in-plane retardation (590) of the first optical laminate when placed in a 65°C / 90% humidity environment for 500 hours (retardation change XD) and the change in in-plane retardation (590) of the second optical laminate when placed in a 65°C / 90% humidity environment for 500 hours (retardation change XL) satisfy the relationship |XD-XL|≦3 nm.

[0012] The optical laminate set can be applied to a display system (for example, goggles with a display). Fig. 1 is a schematic diagram showing an example of a display system including the optical laminate set.

[0013] As shown in FIG. 1 , the display system 2 includes a display element 12, a reflective polarizing member 14, a first lens unit 16, a half mirror 18, a first phase difference member 20, a second phase difference member 22, and a second lens unit 24. The reflective polarizing member 14 is disposed in front of the display surface 12′ side 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 reflective polarizing member 14, and the half mirror 18 is disposed between the display element 12 and the first lens unit 16. The first phase difference member 20 is disposed on the optical path between the display element 12 and the half mirror 18, and the second phase difference member 22 is disposed on the optical path between the half mirror 18 and the reflective polarizing member 14. Although not shown, the display system 2 may further include an absorptive polarizing member between the reflective polarizing member 14 and the second lens unit 24.

[0014] The components arranged in front of the half mirror (in the illustrated example, the half mirror 18, the first lens section 16, the second phase difference member 22, the reflective polarizing member 14, and the second lens section 24) may be collectively referred to as the lens section (lens section 4).

[0015] The display element 12 is, for example, a liquid crystal display or an organic EL display, and has a display surface 12' for displaying an image. Light emitted from the display surface 12' passes through, for example, a polarizing member 10 that may be included in the display element 12, and is converted into first linearly polarized light.

[0016] The first phase difference member 20 includes a first λ / 4 member that can convert first linearly polarized light incident on the first phase difference member 20 into first circularly polarized light. When the first phase difference member does not include any member other than the first λ / 4 member, the first phase difference member may correspond to the first λ / 4 member. In addition to the first λ / 4 member, the first phase difference member 20 may also include a member whose refractive index characteristics satisfy the relationship nz > nx = ny (hereinafter also referred to as a "first positive C plate").

[0017] The half mirror 18 transmits light emitted from the display element 12 and reflects light reflected by the reflective polarizing member 14 toward the reflective polarizing member 14. The half mirror 18 can be provided integrally with the first lens portion 16.

[0018] The second phase difference member 22 includes a second λ / 4 member that can transmit light reflected by the reflective polarizing member 14 and the half mirror 18 through the reflective polarizing member 14. When the second phase difference member does not include any member other than the second λ / 4 member, the second phase difference member may correspond to the second λ / 4 member. The second phase difference member 22 may be provided integrally with the first lens portion 16.

[0019] The first circularly polarized light emitted from the first λ / 4 element included in the first phase difference element 20 passes through the half mirror 18 and the first lens portion 16, and is converted into the second linearly polarized light by the second λ / 4 element included in the second phase difference element 22. The second linearly polarized light emitted from the second λ / 4 element is reflected toward the half mirror 18 without passing through the reflective polarizing element 14. At this time, the polarization direction of the second linearly polarized light incident on the reflective polarizing element 14 is the same as the reflection axis of the reflective polarizing element 14. Therefore, the second linearly polarized light incident on the reflective polarizing element 14 is reflected by the reflective polarizing element 14.

[0020] The second linearly polarized light reflected by the reflective polarizing element 14 is converted into second circularly polarized light by the second λ / 4 element included in the second phase difference element 22, and the second circularly polarized light output from the second λ / 4 element passes through the first lens unit 16 and is reflected by the half mirror 18. The second 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 element included in the second phase difference element 22. The third linearly polarized light is transmitted through the reflective polarizing element 14. At this time, the polarization direction of the third linearly polarized light incident on the reflective polarizing element 14 is the same as the transmission axis of the reflective polarizing element 14. Therefore, the third linearly polarized light incident on the reflective polarizing element 14 is transmitted through the reflective polarizing element 14.

[0021] The display system 2 may include an absorptive polarizing element (typically, an absorptive polarizing film) in front of the reflective polarizing element 14 (the side closer to the eyes). The reflection axis of the reflective polarizing element 14 and the absorption axis of the absorptive polarizing element may be arranged substantially parallel to each other, and the transmission axis of the reflective polarizing element and the transmission axis of the absorptive polarizing element may be arranged substantially parallel to each other. This allows the third linearly polarized light that has passed through the reflective polarizing element 14 to pass directly through the absorptive polarizing element. The reflective polarizing element and the absorptive polarizing element may be laminated together, for example, via an adhesive layer.

[0022] The light transmitted through the reflective polarizing member 14 passes through the second lens portion 24 and enters the user's eye 26 .

[0023] For example, the absorption axis of the polarizing member 10 included in the display element 12 and the reflection axis of the reflective polarizing member 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 10 included in the display element 12 and the slow axis of the first λ / 4 member included in the first phase difference member 20 is, for example, 40° to 50°, may be 42° to 48°, or may be approximately 45°. The angle formed between the absorption axis of the polarizing member 10 included in the display element 12 and the slow axis of the second λ / 4 member included in the second phase difference member 22 is, for example, 40° to 50°, may be 42° to 48°, or may be approximately 45°.

[0024] Typically, the first optical laminate may include a first phase difference member 20. Therefore, the first optical laminate may be disposed on the optical path between the display element 12 and the half mirror 18. Furthermore, the second optical laminate may include a second phase difference member 22. Therefore, the second optical laminate may be disposed on the optical path between the half mirror 18 and the reflective polarizing member 14. When the set of optical laminates is applied to the display system, the phase difference change XD and the phase difference change XL satisfy the relationship |XD-XL|≦3 nm, thereby suppressing the occurrence of ghosting in the display system even in a high-humidity environment. According to an embodiment of the present invention, even if the phase difference changes of the first optical laminate and the second optical laminate are large, the display characteristics can be improved as described above. Therefore, the design freedom for the first optical laminate or the second optical laminate can be increased. For example, the thickness of the pressure-sensitive adhesive layer can be increased to improve the adhesiveness, etc. of the pressure-sensitive adhesive layer while preventing deterioration of the display characteristics.

[0025] The absolute value of the difference (|XD-XL|) between the change in in-plane retardation (590) of the first optical laminate when placed in a 65°C / 90% humidity environment for 500 hours (retardation change XD) and the change in in-plane retardation (590) of the second optical laminate when placed in a 65°C / 90% humidity environment for 500 hours (retardation change XL) is preferably 2.5 nm or less, more preferably 2.0 nm or less, even more preferably 1.5 nm or less, particularly preferably 1.0 nm or less, and most preferably 0.5 nm or less. Within such a range, the above-mentioned effect is remarkable. Note that the retardation changes XD and XL mean the difference between the in-plane retardation (590) at room temperature and the in-plane retardation (590) when placed in a high humidity environment (65°C / 90% humidity environment) for 500 hours (in-plane retardation in a high temperature environment - in-plane retardation at room temperature).

[0026] The absolute value of the change in in-plane retardation (590) of the first optical laminate (retardation change XD) is preferably 10 nm or less, more preferably 8 nm or less, and even more preferably 6 nm or less. The absolute value of the change in in-plane retardation (590) of the second optical laminate (retardation change XL) is preferably 10 nm or less, more preferably 8 nm or less, and even more preferably 6 nm or less.

[0027] In one embodiment, the first optical laminate and the second optical laminate include two or more optical members. The first optical laminate and the second optical laminate may include two or more types of optical members. The first optical laminate and the second optical laminate may include a pressure-sensitive adhesive layer. In each of the first optical laminate and the second optical laminate, the optical members may be laminated via a pressure-sensitive adhesive layer. In one embodiment, the phase difference change (the |XD-XL|) of the first optical laminate and the second optical laminate can be controlled by the number of layers, composition, thickness, etc. of the pressure-sensitive adhesive layer.

[0028] In one embodiment, the first optical laminate includes 3 or more, 4 or more, 5 or more, or 6 to 10 optical members. The first optical laminate may also include 3 or more, 4 or more, 5 or more, or 6 to 10 optical members.

[0029] In one embodiment, the second optical laminate includes 3 or more, 4 or more, 5 or more, or 6 to 10 optical members. The second optical laminate may also include 3 or more, 4 or more, 5 or more, or 6 to 10 optical members.

[0030] In one embodiment, the number of optical elements in the second optical stack is less than the number of optical elements in the first optical stack.

[0031] In one embodiment, the number of pressure-sensitive adhesive layers in the first optical laminate is 2 or more, 3 or more, 4 or more, or 5 to 9. The first optical laminate may also include 2 or more, 3 or more, 4 or more, or 5 to 9 types of pressure-sensitive adhesive layers. In this specification, different types of pressure-sensitive adhesive layers refer to pressure-sensitive adhesive layers with different compositions. Therefore, for example, pressure-sensitive adhesive layers that have the same composition but different thicknesses are considered to be the same type of pressure-sensitive adhesive layer.

[0032] In one embodiment, the number of pressure-sensitive adhesive layers in the second optical laminate is 2 or more, 3 or more, 4 or more, or 5 to 9. The second optical laminate may include 2 or more, 3 or more, 4 or more, or 5 to 9 types of pressure-sensitive adhesive layers.

[0033] In one embodiment, the number of pressure-sensitive adhesive layers in the first optical laminate is greater than the number of pressure-sensitive adhesive layers in the second optical laminate.

[0034] In one embodiment, the first optical laminate includes two or more pressure-sensitive adhesive layers, and at least two of the pressure-sensitive adhesive layers have different thicknesses.

[0035] In one embodiment, the second optical laminate includes two or more pressure-sensitive adhesive layers, and at least two of the pressure-sensitive adhesive layers have different thicknesses.

[0036] Examples of optical members included in the optical laminate include an absorptive polarizing member, a reflective polarizing member, a phase difference member, etc. In this specification, the optical member refers to a member having optical properties (e.g., polarization, light refraction, light scattering, light reflectivity, light transmittance, light absorption, light diffraction, optical rotation, etc.).

[0037] 2A and 2B are schematic cross-sectional views of a first optical laminate according to one embodiment of the present invention. The first optical laminate 100a shown in FIG. 2A includes, in this order, a first pressure-sensitive adhesive layer a1, a polarizing member 10, a second pressure-sensitive adhesive layer a2, a first phase difference member 20, a third pressure-sensitive adhesive layer a3, and a protective member 30. Specifically, the polarizing member 10 and the first phase difference member 20 are bonded together via the second pressure-sensitive adhesive layer a2, and the first phase difference member 20 and the protective member 30 are bonded together via the third pressure-sensitive adhesive layer a3. The first pressure-sensitive adhesive layer a1 is a pressure-sensitive adhesive layer for bonding the first optical laminate 100a to an adjacent member (e.g., another member constituting display-equipped goggles), and its surface may be protected by a release liner until use.

[0038] (Adhesive Layer) As described above, the first adhesive layer, the second adhesive layer and the third adhesive layer may be adhesive layers of the same type or different types.

[0039] The pressure-sensitive adhesive layer can 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. By adjusting the type, number, combination, and compounding ratio of monomers forming the base resin of the pressure-sensitive adhesive, as well as the compounding amount of cross-linking agent, reaction temperature, reaction time, etc., a pressure-sensitive adhesive having desired properties according to the purpose can be prepared. 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.

[0040] For example, the pressure-sensitive adhesive layer can be formed by applying a pressure-sensitive adhesive composition containing a base resin, additives such as a crosslinking agent, and a solvent, followed by drying. The pressure-sensitive adhesive composition may be applied directly to the adherend, or may be applied to a separately prepared substrate such as a base film (e.g., a release liner). Drying is typically performed by heating.

[0041] The thickness of the pressure-sensitive adhesive layer is, for example, 1 μm to 100 μm, preferably 3 μm to 70 μm, more preferably 5 μm to 50 μm, even more preferably 10 μm to 40 μm, and particularly preferably 15 μm to 30 μm. In one embodiment, the retardation change (XD, XL) of the optical laminate can be controlled by adjusting the thickness of the pressure-sensitive adhesive layer. For example, the retardation change (XD, XL) can be reduced by making the pressure-sensitive adhesive layer thinner.

[0042] In one embodiment, the pressure-sensitive adhesive layer is formed to a thickness of more than 5 μm. By increasing the thickness of the pressure-sensitive adhesive layer, adhesion can be improved. In particular, increasing the thickness of the pressure-sensitive adhesive layer (e.g., the first pressure-sensitive adhesive layer) used to attach the optical laminate to an adjacent member (e.g., another member constituting display-equipped goggles) is advantageous in that peeling from the member can be prevented. Furthermore, by increasing the thickness of the pressure-sensitive adhesive layer, the influence of foreign matter on the adherend can be alleviated. In the set of optical laminates, adjusting the relationship between the phase difference change XD of the first optical laminate and the phase difference change XL of the second optical laminate is a requirement for improving display characteristics. Therefore, even if the pressure-sensitive adhesive layer is made thicker, the influence (e.g., the influence of an increase in the phase difference change value of the optical laminate alone) can be suppressed, thereby improving display characteristics.

[0043] The storage modulus of the pressure-sensitive adhesive layer at 25°C is preferably 0.01 MPa to 3 MPa, more preferably 0.05 MPa to 1 MPa, and even more preferably 0.1 MPa to 0.5 MPa. In one embodiment, the retardation change (XD, XL) of the optical laminate can be controlled by adjusting the elastic modulus of the pressure-sensitive adhesive layer. For example, the retardation change (XD, XL) can be reduced by increasing the elastic modulus of the pressure-sensitive adhesive layer. The storage modulus can be determined, for example, by dynamic viscoelasticity measurement (e.g., measurement conditions: parallel plate (8.0 mmφ), torsion mode, frequency range 1 Hz) using a dynamic viscoelasticity measurement device ("Advanced Rheometric Expansion System (ARES)", manufactured by Rheometric Scientific).

[0044] The coefficient of linear expansion of the pressure-sensitive adhesive layer when heated from 60° C. to 70° C. is, for example, 6.5×10 －４ / ℃ or more 10.0 x 10 －４ / °C or less. In one embodiment, the phase difference change (XD, XL) of the optical laminate can be controlled by adjusting the linear expansion coefficient of the pressure-sensitive adhesive layer. For example, the phase difference change (XD, XL) can be reduced by reducing the linear expansion coefficient of the pressure-sensitive adhesive layer. The linear expansion coefficient is measured by TMA measurement. The TMA measurement can be performed under the following conditions. Measurement sample: 5 mm square x 1 mm Measurement device: "TMA / SS6000" manufactured by SII NanoTechnology Inc. Measurement mode: Compression expansion method Measurement load: 9.8 mN Probe diameter: 3.5 mmφ (compression expansion method) Temperature program: -60°C → 210°C → -70°C → 200°C Heating / cooling rate: 10°C / min Measurement atmosphere: N ２ (Flow rate: 200ml / min)

[0045] In one embodiment, there is provided a method for controlling the in-plane retardation change X of an optical laminate including a pressure-sensitive adhesive layer and an optical member in a high-humidity environment, the method comprising adjusting the type and / or thickness of the pressure-sensitive adhesive layer. The high-humidity environment may be, for example, an environment with a temperature of 40°C to 95°C and a humidity of 80% to 100%. The in-plane retardation change X may be a retardation change at a wavelength of 550 nm. The type of pressure-sensitive adhesive layer can be distinguished by adjusting the type, number, combination, and compounding ratio of monomers forming the base resin of the pressure-sensitive adhesive, as well as the compounding amount, reaction temperature, reaction time, etc. of the crosslinking agent (resulting in the physical properties of the pressure-sensitive adhesive layer).

[0046] (Polarizing Member) The polarizing member 10 is typically an absorptive polarizing member including a resin film (sometimes referred to as an absorptive polarizing film) containing a dichroic material, and may further include a protective layer on one or both sides thereof, as necessary. The protective layer is typically bonded to the absorptive polarizing film via any suitable adhesive layer. A typical example of the adhesive that forms the adhesive layer is an ultraviolet-curable adhesive.

[0047] 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.

[0048] 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 Z8701 and corrected for visibility. Degree of polarization P (%) = {(Tp - Tc) / (Tp + Tc)} １／２ ×100

[0049] The thickness of the absorptive polarizing film is, for example, 1 μm or more and 20 μm or less, or may be 2 μm or more and 15 μm or less, or may be 12 μm or less, or may be 10 μm or less, or may be 8 μm or less, or may be 5 μm or less.

[0050] 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.

[0051] When the absorptive polarizing film is produced from a single-layer resin film, for example, an absorptive polarizing film can be obtained by subjecting a hydrophilic polymer film such as a polyvinyl alcohol (PVA)-based film, a partially formalized PVA-based film, or a partially saponified ethylene-vinyl acetate copolymer-based film to a dyeing treatment with iodine or a dichroic substance such as a dichroic dye, a stretching treatment, etc. Among these, an absorptive polarizing film obtained by dyeing a PVA-based film with iodine and uniaxially stretching it is preferred.

[0052] The dyeing with iodine is carried out, for example, by immersing the PVA-based 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 PVA-based film may be dyed after stretching. If necessary, the PVA-based film may be subjected to a swelling treatment, a crosslinking treatment, a washing treatment, a drying treatment, or the like.

[0053] 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, and 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 solution 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 to stretch it. Furthermore, the stretching may optionally include in-air stretching of the laminate at a high temperature (e.g., 95°C or higher) before stretching in the boric acid aqueous solution. In addition, in this embodiment, the laminate is preferably subjected to a drying shrinkage treatment in which the laminate is heated 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 auxiliary in-air 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 the PVA, even when the PVA is coated on a thermoplastic resin, thereby achieving high optical properties. Furthermore, by simultaneously increasing the orientation of the PVA in advance, problems such as a decrease in orientation or dissolution of the PVA when immersed in water in the subsequent dyeing or 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 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 the absorptive polarizing film obtained through treatment steps in which the laminate is immersed in a liquid, such as dyeing treatment and underwater stretching treatment, etc. Furthermore, the optical properties can be improved by shrinking the laminate in the width direction through a 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 an absorptive polarizing film are described in, for example, JP-A-2012-73580 and Japanese Patent No. 6,470,455. The entire disclosures of these publications are incorporated herein by reference.

[0054] The protective layer is formed of any appropriate film that can be used as a protective layer for an absorptive polarizing film. Specific examples of materials that can be used as the main component of the film include cycloolefin (COP) resins such as polynorbornene resins, polyester resins such as polyethylene terephthalate (PET) resins, cellulose resins such as triacetyl cellulose (TAC), and transparent resins such as polycarbonate (PC), (meth)acrylic resins, polyvinyl alcohol resins, polyamides, polyimides, polyethersulfones, polysulfones, polystyrenes, polyolefins, and acetate resins. Other examples include thermosetting or ultraviolet-curing resins such as (meth)acrylic, urethane, (meth)acrylic urethane, epoxy, and silicone resins. Other examples include glassy polymers such as siloxane polymers. Polymer films described in JP 2001-343529 A (WO 01 / 37007) can also be used. Examples of materials that can be used for this film include resin compositions containing a thermoplastic resin having a substituted or unsubstituted imide group in its side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group in its side chain, such as a resin composition containing an alternating copolymer of isobutene and N-methylmaleimide and an acrylonitrile-styrene copolymer. The polymer film can be, for example, an extrusion molded product of the above resin composition. The resin film materials can be used alone or in combination.

[0055] The thickness of the protective layer is typically 100 μm or less, for example, 5 μm to 80 μm, preferably 10 μm to 50 μm, and more preferably 15 μm to 35 μm.

[0056] (First Retardation Member) The first retardation member 20 includes a first λ / 4 member 20a. The first λ / 4 member 20a is arranged so that the angle between the absorption axis of the polarizing member 10 (absorptive polarizing film) and the slow axis of the first λ / 4 member 20a is preferably 40° to 50°, more preferably 42° to 48°, for example, approximately 45°.

[0057] As shown in FIG. 2B , the first phase difference member 20 may include, in addition to the first λ / 4 member 20a, a member (so-called positive C plate) 20b whose refractive index characteristics can exhibit the relationship nz > nx = ny. The first λ / 4 member 20a and the positive C plate 20b may be laminated via an adhesive layer b1. As shown in the example, it is preferable that the first λ / 4 member 20a is located closer to the polarizing member 10 than the positive C plate 20b, but the arrangement may be reversed. The adhesive layer b1 is typically a pressure-sensitive adhesive layer or an adhesive layer.

[0058] The in-plane retardation Re(550) of the first λ / 4 component 20a is, for example, 100 nm to 190 nm, or may be 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The first λ / 4 component preferably exhibits an inverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light. The Re(450) / Re(550) of the first λ / 4 component may be, for example, 0.75 or more and less than 1, or 0.8 or more and 0.95 or less.

[0059] The first λ / 4 member preferably has a refractive index characteristic that satisfies the relationship nx>ny≧nz. Here, "ny=nz" does not only include the case where ny and nz are completely equal, but also includes the case where they are substantially equal. Therefore, there may be cases where ny<nz, as long as the effects of the present invention are not impaired. The Nz coefficient of the first λ / 4 member 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.

[0060] The first λ / 4 member may be made of any suitable material that satisfies the above-mentioned characteristics, and may be, for example, a stretched resin film or an oriented and solidified layer of a liquid crystal compound.

[0061] Examples of resins contained in the resin film include polycarbonate-based resins, polyester carbonate-based resins, polyester-based resins, polyvinyl acetal-based resins, polyarylate-based resins, cyclic olefin-based resins, cellulose-based resins, polyvinyl alcohol-based resins, polyamide-based resins, polyimide-based resins, polyether-based resins, polystyrene-based resins, and acrylic-based resins. These resins may be used alone or in combination. Examples of methods for combining include blending and copolymerization. When the first λ / 4 member exhibits reverse dispersion wavelength characteristics, a resin film containing a polycarbonate-based resin or a polyester carbonate-based resin (hereinafter sometimes simply referred to as a polycarbonate-based resin) can be suitably used.

[0062] Any suitable polycarbonate resin can be used as the polycarbonate resin. For example, the polycarbonate 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 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 resin may contain structural units derived from other dihydroxy compounds as needed. Details of polycarbonate-based resins that can be suitably used for the first λ / 4 member and methods for forming the first λ / 4 member are described, for example, in JP 2014-10291 A, JP 2014-26266 A, JP 2015-212816 A, JP 2015-212817 A, and JP 2015-212818 A, and the descriptions in these publications are incorporated herein by reference.

[0063] The thickness of the first λ / 4 member made of a stretched resin film is, for example, 10 μm to 100 μm, preferably 10 μm to 70 μm, and more preferably 20 μm to 60 μm.

[0064] The above-mentioned liquid crystal compound alignment solidified layer is a layer in which the liquid crystal compound is aligned in a predetermined direction within the layer and the alignment state is fixed. The term "alignment solidified layer" encompasses an alignment solidified layer obtained by curing a liquid crystal monomer, as described below. In the first λ / 4 member, typically, rod-shaped liquid crystal compounds are aligned in the slow axis direction of the first λ / 4 member (homogeneous alignment). Examples of rod-shaped liquid crystal compounds include liquid crystal polymers and liquid crystal monomers. The liquid crystal compound is preferably polymerizable. If the liquid crystal compound is polymerizable, the alignment state of the liquid crystal compound can be fixed by aligning the liquid crystal compound and then polymerizing it.

[0065] The alignment and solidification layer of the liquid crystal compound (liquid crystal alignment and solidification layer) can be formed by performing an alignment treatment on the surface of a predetermined substrate, applying a coating liquid containing a liquid crystal compound to the surface to align the liquid crystal compound in a direction corresponding to the alignment treatment, and fixing the alignment state. Any appropriate alignment treatment can be used as the alignment treatment. Specific examples include mechanical alignment treatment, physical alignment treatment, and chemical alignment treatment. Specific examples of mechanical alignment treatment include rubbing treatment and stretching treatment. Specific examples of physical alignment treatment include magnetic field alignment treatment and electric field alignment treatment. Specific examples of chemical alignment treatment include oblique vapor deposition and photoalignment treatment. Any appropriate treatment conditions can be used for the various alignment treatments depending on the purpose.

[0066] The alignment of liquid crystal compounds is achieved by treating them at a temperature at which they exhibit a liquid crystal phase depending on the type of liquid crystal compound. By performing such temperature treatment, the liquid crystal compounds assume a liquid crystal state and are aligned in accordance with the alignment treatment direction on the substrate surface.

[0067] In one embodiment, the alignment state is fixed by cooling the liquid crystal compound aligned as described above. When the liquid crystal compound is polymerizable or crosslinkable, the alignment state is fixed by subjecting the liquid crystal compound aligned as described above to a polymerization treatment or a crosslinking treatment.

[0068] Any suitable liquid crystal polymer and / or liquid crystal monomer can be used as the liquid crystal compound. The liquid crystal polymer and the liquid crystal monomer can be used alone or in combination. Specific examples of liquid crystal compounds and methods for producing a liquid crystal alignment solidified layer are described in, for example, JP 2006-163343 A, JP 2006-178389 A, and WO 2018 / 123551 A. The descriptions in these publications are incorporated herein by reference.

[0069] The thickness of the first λ / 4 member formed of the liquid crystal alignment solidified layer is, for example, 1 μm to 10 μm, preferably 1 μm to 8 μm, more preferably 1 μm to 6 μm, and even more preferably 1 μm to 4 μm.

[0070] (Protective Member) The protective member 30 typically includes a substrate. The substrate may be composed of any appropriate film. Examples of materials that form the main component of the film constituting 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, and acetate-based resins. The thickness of the substrate is preferably 5 μm to 80 μm, more preferably 10 μm to 40 μm, and even more preferably 15 μm to 35 μm.

[0071] The protective member preferably has a substrate and a surface treatment layer formed on the substrate. The surface treatment layer may be located on the outermost surface of the optical laminate 100a. The surface treatment layer may have any appropriate function. Examples of the surface treatment layer include a hard coat layer, an anti-reflection layer, an anti-sticking layer, and an anti-glare layer. The protective member may have two or more surface treatment layers.

[0072] The antireflection layer is provided to prevent reflection of external light, etc. Examples of the antireflection layer include a fluororesin layer, a resin layer containing nanoparticles (typically hollow nanoparticles, e.g., hollow nanosilica particles), and an antireflection layer having a nanostructure (e.g., a moth-eye structure). The thickness of the antireflection layer is preferably 0.05 μm to 1 μm. Examples of methods for forming the resin layer include a sol-gel method, a heat curing method using an isocyanate, and an ionizing radiation curing method (typically, a photocuring method) using a crosslinkable monomer (e.g., a polyfunctional acrylate) and a photopolymerization initiator.

[0073] The hard coat layer preferably has sufficient surface hardness, excellent mechanical strength, and excellent light transmittance. The hard coat layer can be formed from any appropriate resin. The hard coat layer is typically formed from an ultraviolet-curable resin. Examples of ultraviolet-curable resins include polyester-based, acrylic-based, urethane-based, amide-based, silicone-based, and epoxy-based resins. The thickness of the hard coat layer is, for example, 0.5 μm or more, preferably 1 μm or more, and, for example, 20 μm or less, preferably 15 μm or less.

[0074] (Positive C Plate) The thickness direction retardation Rth(550) of the positive C plate 20b is preferably −50 nm to −300 nm, more preferably −70 nm to −250 nm, even more preferably −90 nm to −200 nm, and particularly preferably −100 nm to −180 nm. Here, "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.

[0075] The positive C plate can be formed from any appropriate material. The positive C plate 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 a retardation layer described in paragraphs

[0020] to

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

[0076] 3A and 3B are schematic cross-sectional views of a second optical laminate according to one embodiment of the present invention. The second optical laminate 200a shown in Fig. 3A has, in this order, a fourth pressure-sensitive adhesive layer a4, a second phase difference member 22, a fifth pressure-sensitive adhesive layer a5, and a protective member 30. Specifically, the second phase difference member 22 and the protective member 30 are bonded together via the fifth pressure-sensitive adhesive layer a5. The fourth pressure-sensitive adhesive layer a4 is a pressure-sensitive adhesive layer for bonding the optical laminate 200a itself to an adjacent member (for example, another member constituting the display-equipped goggles), and the surface thereof may be protected by a release liner until use.

[0077] The adhesive layer and the protective member are as described above. The second retardation member 22 includes a third λ / 4 member 22a. The same description as for the first 4 / λ member applies to the third λ / 4 member. The first λ / 4 member and the third λ / 4 member may be identical in configuration (e.g., material, thickness, optical properties, etc.) or may be different in configuration. The in-plane retardation Re(550) of the third λ / 4 member is, for example, 100 nm to 190 nm, 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The third λ / 4 member preferably exhibits inverse dispersion wavelength characteristics in which the retardation value increases with the wavelength of the measurement light. The third λ / 4 member preferably satisfies the relationship Re(450)<Re(550)<Re(650). The Re(450) / Re(550) of the third λ / 4 member is, for example, 0.75 or more and less than 1, and may be 0.8 or more and 0.95 or less.

[0078] 3B , the second phase difference member 22 may include, in addition to the third λ / 4 member 22a, a member (so-called positive C plate) 22b whose refractive index characteristics can exhibit the relationship nz > nx = ny. The positive C plate is as described above. The third λ / 4 member 22a and the positive C plate 22b are laminated via an adhesive layer b1.

[0079] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. The thickness and other values ​​are measured by the following measurement methods. <Thickness> Thicknesses of 10 μm or less were measured using a scanning electron microscope (manufactured by JEOL Ltd., product name "JSM-7100F"). Thicknesses of more than 10 μm were measured using a digital micrometer (manufactured by Anritsu Corporation, product name "KC-351C"). <In-plane retardation> The in-plane retardation at 23°C was measured using a "KOBRA-WPR" manufactured by Oji Scientific Instruments.

[0080] [Production Example 1] (Formation of Pressure-Sensitive Adhesive Layers A and B) 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-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser. Furthermore, 0.3 parts by weight of dibenzoyl peroxide as a polymerization initiator was charged together 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, and the liquid temperature in the flask was maintained at 60°C, allowing the polymerization reaction to proceed for 7 hours. Ethyl acetate was then added to the resulting reaction solution to adjust the solids concentration to 30% by weight, thereby preparing a solution of an acrylic polymer having a weight-average molecular weight (Mw) of 2,200,000. An acrylic pressure-sensitive 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 solids content of the obtained acrylic polymer solution. The obtained acrylic pressure-sensitive adhesive was applied to a substrate film, and the resulting coating film on the substrate film was dried in an oven to form a pressure-sensitive adhesive layer A having a thickness of 12 μm and a pressure-sensitive adhesive layer B having a thickness of 20 μm.

[0081] [Production Example 2] (Formation of Pressure-Sensitive Adhesive Layer C) A four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with a monomer mixture containing 92 parts by weight of butyl acrylate, 5 parts by weight of N-acryloylmorpholine, 2.9 parts by weight of acrylic acid, and 0.1 parts by weight of 2-hydroxyethyl acrylate. Furthermore, 0.1 parts by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator was charged together with 100 parts by weight of ethyl acetate per 100 parts by weight of this monomer mixture. Nitrogen gas was introduced with gentle stirring to replace the atmosphere in the flask with nitrogen, and then the liquid temperature in the flask was maintained at around 55°C to carry out a polymerization reaction for 8 hours, thereby preparing a solution of an acrylic polymer having a weight average molecular weight (Mw) of 2,000,000. An acrylic pressure-sensitive adhesive was prepared by mixing 100 parts by weight of the solids content of the acrylic polymer solution with 0.15 parts by weight of dibenzoyl peroxide (1-minute half-life: 130°C) as a crosslinking agent and 0.6 parts by weight of a polyisocyanate crosslinking agent consisting of a trimethylolpropane adduct of tolylene diisocyanate (Coronate L, manufactured by Nippon Polyurethane Industry Co., Ltd.). The resulting acrylic pressure-sensitive adhesive was coated on a substrate film, and the resulting coating on the substrate film was dried in an oven to form a 5 μm-thick pressure-sensitive adhesive layer C.

[0082] [Production Example 3] (Preparation of Absorptive Polarizing Film) A long, amorphous, isophthalic-copolymerized polyethylene terephthalate film (thickness: 100 μm) with a Tg of approximately 75°C was used as the thermoplastic resin substrate. One side of the resin substrate was subjected to a corona treatment. A PVA-based resin (a 9:1 mixture of polyvinyl alcohol (degree of polymerization: 4200, degree of saponification: 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Mitsubishi Chemical Corporation, trade name "GOHSENEX Z410") was prepared by dissolving 100 parts by weight of the resulting PVA-based resin in water, along with 13 parts by weight of potassium iodide. The PVA-based resin was applied to the corona-treated surface of the resin substrate and dried at 60°C to form a 13 μm-thick PVA-based resin layer, producing a laminate. The resulting laminate was uniaxially stretched 2.4 times in the longitudinal direction (machine direction) in an oven at 130°C (in-air auxiliary stretching treatment). Next, the laminate was immersed for 30 seconds in an insolubilizing bath (a boric acid aqueous solution obtained by blending 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40°C (insolubilization treatment), then immersed for 60 seconds in a dyeing bath (an iodine aqueous solution obtained by blending 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 while adjusting the concentration so that the single-unit transmittance (Ts) of the finally obtained absorptive polarizing film would have a desired value (dyeing treatment), then immersed for 30 seconds 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 (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 (machine direction) between rolls operating at different peripheral speeds to a total stretch ratio of 5.5 (underwater stretching treatment). The laminate was then immersed in a cleaning bath (aqueous solution obtained by blending 4 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 20°C (washing treatment). The laminate was then dried in an oven maintained at approximately 90°C and brought into contact with a stainless steel heated roll maintained at a surface temperature of 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 manner, an absorptive polarizing film having a thickness of approximately 5 μm was formed on the resin substrate.

[0083] (Preparation of Absorptive Polarizing Element) A 40 μm-thick acrylic film having a lactone ring structure was bonded 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 UV-curable adhesive was applied to a thickness of 2 μm, and the films were bonded 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, an absorptive polarizing element 1 having an acrylic film / absorptive polarizing film configuration was obtained. The absorptive polarizing element 1 had a single transmittance (Ts) of 43.4% and a polarization degree of 99.993%.

[0084] [Production Example 4: Preparation of λ / 4 member] 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 Parts by mass (6.78×10 －５mol) was charged. After purging the reactor with nitrogen under reduced pressure, heating was performed with a heat medium, and stirring was initiated when the internal temperature reached 100°C. 40 minutes after the start of the temperature increase, the internal temperature reached 220°C, and while controlling to maintain this temperature, pressure reduction was initiated. 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 a small amount of monomer components contained in the phenol vapor were returned to the reactor, while uncondensed phenol vapor was introduced into a condenser at 45°C and recovered. Nitrogen was introduced into the first reactor, and the pressure was temporarily restored to atmospheric pressure. The oligomerized reaction liquid in the first reactor was then transferred to the second reactor. Next, heating and pressure reduction in the second reactor were initiated, and the internal temperature reached 240°C and the pressure reached 0.2 kPa in 50 minutes. Polymerization was then allowed to proceed until the predetermined stirring power was achieved. 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.

[0085] The obtained polyester carbonate resin (pellets) was vacuum-dried at 80 ° C for 5 hours, and then a film-forming device equipped with a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder set temperature: 250 ° C), a T-die (width 200 mm, set temperature: 250 ° C), a chill roll (set temperature: 120-130 ° C), and a winder was used to produce a long resin film with a thickness of 135 μm. The obtained long resin film was stretched in the width direction at a stretching temperature of 143 ° C and a stretch ratio of 2.8 times. This resulted in a stretched film (λ / 4 member 1) with a thickness of 47 μm. The Re (590) of the λ / 4 member 1 was 143 nm, the Re (450) / Re (550) was 0.86, and the Nz coefficient was 1.12.

[0086] [Production Example 5: Preparation of Protective Member] The hard coat layer-forming material shown below was applied to an acrylic film having a lactone ring structure, and the applied layer was dried to form a hard coat layer having a thickness of 0.5 μm. Next, the antireflection layer-forming material shown below was applied to the surface of the hard coat layer and heated at 80° 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. ２The coating layer was cured by irradiating it with ultraviolet light of 1000 W at ...

[0087] (Hard Coat Layer Forming Material) A hard coat layer forming material was prepared by adding 0.5 wt % of a leveling agent to an acrylic resin raw material (manufactured by Dai Nippon Ink & Chemicals, product name: GRANDIC PC1071) and further diluting with ethyl acetate to a solids concentration of 50 wt %. The leveling agent was a copolymer copolymerized in a molar ratio of dimethylsiloxane:hydroxypropylsiloxane:6-isocyanatehexylisocyanuric acid:aliphatic polyester = 6.3:1.0:2.2:1.0.

[0088] (Antireflection Layer-Forming Material) 100 parts by weight of a polyfunctional acrylate containing pentaerythritol triacrylate as a main component (manufactured by Osaka Organic Chemical Industry Ltd., trade name "Viscoat #300", solid content 100% by weight), 100 parts by weight of hollow nanosilica particles (manufactured by JGC Catalysts and Chemicals Industries, Ltd., trade name "Surulia 5320", solid content 20% by weight, weight average particle diameter 75 nm), 100 parts by weight of solid nanosilica particles (manufactured by Nissan Chemical Industries, Ltd., trade name "MEK-2140Z-AC", solid content 30% by weight, 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% by weight), and 3 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name "OMNIRAD907", solid content 100% by weight) were mixed. To this mixture was added a mixed solvent of tertiary butyl alcohol, methyl isobutyl ketone, and propylene glycol monomethyl ether acetate in a weight ratio of 60:25:15, and the mixture was stirred to give a total solids content of 4% by weight, thereby preparing an anti-reflection layer-forming material.

[0089] [Production Example 6: Production of retardation member (λ / 4 member / positive C plate)] A liquid crystal coating liquid was prepared by dissolving 20 parts by mass of a side-chain liquid crystal polymer represented by the following chemical formula (1) (in the formula, the numbers 65 and 35 indicate the mol % of the monomer unit, and for convenience, it is expressed as a block polymer; weight average molecular weight 5000), 80 parts by mass of a polymerizable liquid crystal exhibiting a nematic liquid crystal phase (manufactured by BASF: trade name Paliocolor LC242), and 5 parts by mass of a photopolymerization initiator (manufactured by Ciba Specialty Chemicals: trade name Irgacure 907) in 200 parts by mass of cyclopentanone. The coating liquid was then applied to a substrate film (norbornene-based resin film: manufactured by Nippon Zeon Corporation, trade name "Zeonex") 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, thereby forming a 4 μm-thick retardation member on the substrate. The retardation member thus obtained had a refractive index of nz > nx = ny. The retardation Rth (590) in the thickness direction of the retardation member (positive C plate) was 80 nm. This retardation member (positive C plate) and the λ / 4 member 1 produced in Production Example 4 were laminated together via an adhesive to obtain a retardation member A.

[0090] Example 1 An adhesive layer B (thickness: 20 μm) was bonded to one surface of an absorptive polarizing member 1, and an adhesive layer A (thickness: 12 μm) was bonded to the other surface. A retardation member A was then bonded thereon so that the λ / 4 member 1 and the absorptive polarizing member 1 faced each other. The absorptive polarizing member 1 and the retardation member A were positioned such that the absorption axis of the absorptive polarizing member 1 and the slow axis of the λ / 4 member 1 formed an angle of 45°. Next, another adhesive layer A (thickness: 12 μm) was placed on the surface of the λ / 4 member 1, and a protective member 1 was then bonded thereon. The protective member 1 was bonded such that the acrylic film-side surface of the protective member 1 faced the retardation member A (in other words, the surface treatment layer was the outermost surface). In this manner, a first optical laminate A having a configuration of [adhesive layer B / absorptive polarizing member 1 / adhesive layer A / retardation member A (positive C plate / λ / 4 member 1) / adhesive layer A / protective member 1] was obtained. A pressure-sensitive adhesive layer A (12 μm thick) was placed on one surface (the surface on the positive C plate side) of the retardation member A. Furthermore, a protective member 1 was bonded to the other surface of the retardation member A via the pressure-sensitive adhesive layer A (12 μm thick). At this time, the acrylic film-side surface of the protective member 1 was bonded to the retardation member A side (in other words, so that the surface treatment layer was the outermost surface). In this manner, a second optical laminate A having a configuration of [pressure-sensitive adhesive layer B / retardation member A (positive C plate / λ / 4 member 1) / pressure-sensitive adhesive layer A / protective member 1] was obtained. (Evaluation) The retardation changes of the first optical laminate A and the second optical laminate A were measured by the following method. The retardation values ​​at a predetermined wavelength were measured at 23° C. using a retardation measurement device (manufactured by Oji Scientific Instruments, product name "KOBRA-HBPR"). The first optical laminate A and the second optical laminate A attached to the glass were placed in a high-temperature, high-humidity environment (65°C, 90%) for 500 hours, then removed, and the retardation values ​​were measured in the same manner using a retardation measurement device. The retardation values ​​before and after being placed in the high-temperature, high-humidity environment were compared to calculate the change in retardation (after placement - before placement). The results are shown in Table 1.

[0091] Example 2 A first optical laminate A was obtained in the same manner as in Example 1. A pressure-sensitive adhesive layer A (thickness: 12 μm) was disposed on one surface (the surface on the positive C plate side) of the retardation member A. Furthermore, a protective member 1 was attached to the other surface of the retardation member A via a pressure-sensitive adhesive layer C (thickness: 5 μm). At this time, the acrylic film-side surface of the protective member 1 was attached to the retardation member A side (in other words, the surface treatment layer was attached to the outermost surface). In this manner, a second optical laminate B having a configuration of [pressure-sensitive adhesive layer A / retardation member A (positive C plate / λ / 4 member 1) / pressure-sensitive adhesive layer C / protective member 1] was obtained. (Evaluation) Using the first optical laminate A and the second optical laminate B, a sample similar to that in Example 1 was prepared, and the sample was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

[0092] [Example 3] A first optical laminate A was obtained in the same manner as in Example 1. A second optical laminate C was obtained in the same manner as in Example 1, except that the thickness of the pressure-sensitive adhesive layer A was set to 20 μm. (Evaluation) Using the first optical laminate A and the second optical laminate C, a sample similar to that in Example 1 was produced, and the sample was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

[0093] Comparative Example 1 An adhesive layer B (thickness: 20 μm) was bonded to one surface of an absorptive polarizing member 1, and an adhesive layer C (thickness: 5 μm) was bonded to the other surface. The retardation member A was then bonded thereon so that the λ / 4 member 1 and the absorptive polarizing member 1 faced each other. The absorptive polarizing member 1 and the retardation member A were positioned such that the absorption axis of the absorptive polarizing member 1 and the slow axis of the λ / 4 member 1 formed an angle of 45°. Next, an adhesive layer A (thickness: 12 μm) was placed on the surface of the λ / 4 member 1, and a protective member 1 was then bonded thereon. The protective member 1 was bonded such that the acrylic film-side surface of the protective member 1 faced the retardation member A (in other words, the surface treatment layer was the outermost surface). In this manner, a first optical laminate B having a configuration of [adhesive layer B / absorptive polarizing member 1 / adhesive layer C / retardation member A (positive C plate / λ / 4 member 1) / adhesive layer A / protective member 1] was obtained. An adhesive layer C (thickness: 5 μm) was placed on one surface (the surface on the positive C plate side) of the retardation member A. Furthermore, a protective member 1 was attached to the other surface of the retardation member A via an adhesive layer A (thickness: 12 μm). At this time, the protective member 1 was attached so that the acrylic film side surface of the protective member 1 faced the retardation member A side (in other words, so that the surface treatment layer was the outermost surface). In this way, a second optical laminate D having a configuration of [adhesive layer C / retardation member A (positive C plate / λ / 4 member 1) / adhesive layer A / protective member 1] was obtained. (Evaluation) Using the first optical laminate B and the second optical laminate D, a sample similar to that of Example 1 was prepared, and the sample was subjected to the same evaluation as that of Example 1. The results are shown in Table 1.

[0094] Comparative Example 2 A first optical laminate A was obtained in the same manner as in Example 1. A pressure-sensitive adhesive layer C (5 μm thick) was disposed on one surface (the surface on the positive C plate side) of the retardation member A. Furthermore, a protective member 1 was attached to the other surface of the retardation member A via the pressure-sensitive adhesive layer C (5 μm thick). At this time, the acrylic film-side surface of the protective member 1 was attached to the retardation member A side (in other words, the surface treatment layer was attached to the outermost surface). In this manner, a second optical laminate E having a configuration of [pressure-sensitive adhesive layer C / retardation member A (positive C plate / λ / 4 member 1) / pressure-sensitive adhesive layer C / protective member 1] was obtained. (Evaluation) Using the first optical laminate A and the second optical laminate E, a sample similar to that in Example 1 was prepared, and the sample was subjected to the same evaluation as in Example 1. The results are shown in Table 1.

[0095]

[0096] As shown in Table 1, in the examples, a set of optical laminates was obtained in which the difference between the change in in-plane retardation of the first optical laminate and the change in in-plane retardation of the second optical laminate was small. By using these optical laminates, a display system can be obtained in which the optical characteristics are stable even in harsh environments and the occurrence of ghosting is suppressed.

[0097] The optical laminate according to the embodiment of the present invention can be used, for example, in the manufacture of goggles with a display, such as VR goggles.

[0098] 2 Display system 4 Lens section 10 Polarizing member 12 Display element 14 Reflective polarizing member 16 First lens section 18 Half mirror 20 First phase difference member 22 Second phase difference member 24 Second lens section

Claims

1. A set of a first optical laminate and a second optical laminate, wherein the change in in-plane retardation (590) of the first optical laminate when placed in a 65°C / 90% humidity environment for 500 hours (retardation change XD) and the change in in-plane retardation (590) of the second optical laminate when placed in a 65°C / 90% humidity environment for 500 hours (retardation change XL) satisfy the relationship |XD-XL|≦3 nm.

2. The set of optical laminates according to claim 1, wherein the first optical laminate comprises three or more optical members.

3. The set of optical stacks according to claim 2, wherein the number of optical elements in the second optical stack is less than the number of optical elements in the first optical stack.

4. The set of optical laminates according to claim 1, wherein the first optical laminate and the second optical laminate include a pressure-sensitive adhesive layer.

5. The set of optical laminates according to claim 4, wherein the number of pressure-sensitive adhesive layers in the first optical laminate is greater than the number of pressure-sensitive adhesive layers in the second optical laminate.

6. The set of optical laminates according to claim 4, wherein the first optical laminate and the second optical laminate each include two or more types of pressure-sensitive adhesive layers.

7. The set of optical laminates according to claim 4, wherein the first optical laminate comprises two or more pressure-sensitive adhesive layers, and at least two of the pressure-sensitive adhesive layers have different thicknesses.

8. The set of optical laminates according to claim 4, wherein the second optical laminate comprises two or more pressure-sensitive adhesive layers, and at least two of the pressure-sensitive adhesive layers have different thicknesses.

9. The set of optical laminates according to claim 7, wherein the second optical laminate comprises two or more pressure-sensitive adhesive layers, and at least two of the pressure-sensitive adhesive layers have different thicknesses.

10. A method for controlling an in-plane retardation change X of an optical laminate comprising a pressure-sensitive adhesive layer and an optical member in a high-humidity environment, the method comprising adjusting the type and / or thickness of the pressure-sensitive adhesive layer.

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