Method for producing optical laminate with pressure-sensitive adhesive layer

Abstract

To provide a method for manufacturing an optical laminate with an adhesive layer which can suppress erroneous detection of defects in defect inspection.SOLUTION: A method for manufacturing an optical laminate with an adhesive layer having an optical laminate and an adhesive layer arranged on its one surface includes a step A of obtaining the optical laminate with the adhesive layer where a second release liner is arranged on the surface of the adhesive layer, and a step B of inspecting the optical laminate with the adhesive layer in a state where the second release liner is arranged on the surface of the adhesive layer, wherein the step A includes re-labeling a first release liner arranged on the surface of the adhesive layer to a release liner with a surface protective film having the second release liner and the surface protective film arranged on its surface, and then releasing the surface protective film.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for producing a pressure-sensitive adhesive layer-attached optical laminate. [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 polarizing components and phase difference components are generally used to realize image display and improve the performance of the image display (see, for example, Patent Document 1).

[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. In VR goggles, the image displayed on the display is enlarged for the viewer to view, so the optical components used in VR goggles require stricter defect control than the optical components used in conventional image display devices. [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] A pressure-sensitive adhesive layer-attached optical laminate, which includes one or more optical components and has a pressure-sensitive adhesive layer on the outermost layer for bonding to adjacent components, typically protects the surface of the pressure-sensitive adhesive layer with a release liner until use. Therefore, the optical laminate is inspected with the release liner still attached. However, as mentioned above, optical laminates used in goggles with displays require stricter defect control than conventional methods. Automated optical inspection (AOI) is used to detect defects of a size that cannot be detected visually (scratches, stains, irregularities, foreign matter, etc.), such as defects with a diameter of 80 μm or less, for example, 50 μm or less. In this case, if foreign matter adheres to the surface of the release liner, the foreign matter may be erroneously detected as a defect in the pressure-sensitive adhesive layer-attached optical laminate by AOI.

[0006] The present invention is directed to solving the above-mentioned problems, and its main object is to provide a method for producing an optical laminate with a pressure-sensitive adhesive layer that can suppress erroneous detection of defects in defect inspection. [Means for solving the problem]

[0007] [1] According to one aspect of the present invention, there is provided a method for producing an optical laminate with a pressure-sensitive adhesive layer, which has an optical laminate and a pressure-sensitive adhesive layer disposed on one side thereof, the method comprising: step A of obtaining the optical laminate with a pressure-sensitive adhesive layer, in which a second release liner is disposed on the surface of the pressure-sensitive adhesive layer; and step B of inspecting the optical laminate with a pressure-sensitive adhesive layer, with the second release liner disposed on the surface of the pressure-sensitive adhesive layer, wherein step A comprises replacing the first release liner disposed on the surface of the pressure-sensitive adhesive layer with a release liner with a surface protective film, which has the second release liner and a surface protective film disposed on one side of the second release liner, and then peeling off the surface protective film. [2] In the manufacturing method of [1] above, the above step A may include step A-1a of preparing a first intermediate film having the above adhesive layer and the above first release liner disposed on the surface of the above adhesive layer, step A-2a of peeling the above first release liner from the above first intermediate film and laminating the above release liner with a surface protection film on the exposed above adhesive layer to obtain a second intermediate film, step A-3a of laminating a third intermediate film on the side opposite to the side where the above release liner with a surface protection film of the above second intermediate film is disposed to obtain a fourth intermediate film, and step A-4a of peeling the above surface protection film from the above fourth intermediate film. [3] In the manufacturing method of [2] above, the above first intermediate film may further have a polarizing member, and the above third intermediate film may have a first λ / 4 member. [4] In the manufacturing method of [3] above, the above first intermediate film may be produced by a method including preparing a laminate of the above first release liner and the above adhesive layer, and laminating the above laminate with the above polarizing member by the above adhesive layer. [5] In the manufacturing method according to any one of [1] to [4] above, the peeling force of the above surface protection film from the above second release liner (peeling angle 180°, peeling speed 300 mm / min) may be 0.005 N / 50 mm or more and 0.095 N / 50 mm or less. [6] In the manufacturing method according to any one of [1] to [5] above, the peeling force X of the above surface protection film from the above second release liner (peeling angle 180°, peeling speed 300 mm / min) and the peeling force Y of the above second release liner from the above adhesive layer (peeling angle 180°, peeling speed 300 mm / min) may satisfy the relationship 0.2 < X / Y < 1. [7] In the manufacturing method according to any one of [1] to [6] above, the total light transmittance of the above second release liner may be 80% or more. [8] In the manufacturing method according to any one of [1] to [7] above, the total light transmittance of the above first release liner may be 95% or less. [9] In the manufacturing method according to any one of the above [1] to [8], the surface protection film may have a total light transmittance of 95% or less. [Effects of the Invention]

[0008] According to the method for producing a pressure-sensitive adhesive layer-attached optical laminate according to an embodiment of the present invention, during the production of the pressure-sensitive adhesive layer-attached optical laminate, the first release liner protecting the pressure-sensitive adhesive layer is replaced with a release liner with a surface protective film, and only the surface protective film is peeled off and removed before inspection. This makes it possible to provide for inspection a pressure-sensitive adhesive layer-attached optical laminate in which the surface of the pressure-sensitive adhesive layer is protected by the second release liner to which foreign matter adhesion is suppressed. [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] 2(a) and 2(b) are schematic cross-sectional views showing examples of pressure-sensitive adhesive layer-attached optical laminates that can be used in the display system shown in FIG. 1. [Figure 3] FIG. 2 is a schematic diagram illustrating one embodiment of step A. [Figure 4] FIG. 2 is a schematic diagram illustrating one embodiment of step A. [Figure 5] FIG. 10 is a schematic diagram illustrating one embodiment of step B. 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. 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 symbol "to" indicating a numerical range includes the upper and lower limits, and "(meth)acrylic" means "acrylic and / or methacrylic."

[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 an angle is referred to herein, the angle includes both clockwise and counterclockwise angles relative to a reference direction. Thus, for example, "45°" means ±45°. 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°, and "substantially perpendicular" includes angles within a range of 90°±10°, such as 90°±5°, preferably 90°±3°, and more preferably 90°±1°.

[0012] A. Display System According to one aspect of the present invention, a display system is provided. 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 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 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 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 element between the reflective polarizing element 14 and the second lens portion 24 .

[0013] The display element 12 is, for example, a liquid crystal display or an organic EL display, and has a display surface 12a for displaying an image. The light emitted from the display surface 12a 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.

[0014] 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. Note that in the illustrated example, a space is interposed between the first phase difference member 20 and the display element 12, but the first phase difference member 20 and the display element 12 may be provided integrally by using an optical laminate with a pressure-sensitive adhesive layer described in Section B, for example.

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

[0016] 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 unit 16.

[0017] 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 unit 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.

[0018] 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.

[0019] As described above, the display system 2 may include an absorption-type polarizing member (typically, an absorption-type polarizing film) in front of (the side closer to the eyes) the reflective polarizing member 14. The reflection axis of the reflective polarizing member 14 and the absorption axis of the absorption-type polarizing member may be arranged substantially parallel to each other. Thereby, the third linearly polarized light transmitted through the reflective polarizing member 14 can directly transmit through the absorption-type polarizing member. The reflective polarizing member and the absorption-type polarizing member may be laminated via, for example, an adhesive layer.

[0020] The light transmitted through the reflective polarizing member 14 passes through the second lens unit 24 and enters the user's eyes 26.

[0021] 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 arranged substantially parallel to each other or substantially perpendicular to each other. The angle formed by 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 retardation member 20 is, for example, 40° to 50°, may be 42° to 48°, or may be about 45°. The angle formed by the absorption axis of the polarizing member included in the display element 12 and the slow axis of the second λ / 4 member included in the second retardation member 22 is, for example, 40° to 50°, may be 42° to 48°, or may be about 45°.

[0022] The in-plane retardation Re(550) of the first λ / 4 member 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. The first λ / 4 member preferably exhibits an inverse-dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light. The first λ / 4 member preferably satisfies the relationship of Re(450) < Re(550) < Re(650). The Re(450) / Re(550) of the second 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.

[0023] The in-plane phase difference Re(550) of the second λ / 4 member 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. The second λ / 4 member preferably exhibits an inverse dispersion wavelength characteristic in which the phase difference value increases according to the wavelength of the measurement light. The second λ / 4 member preferably satisfies the relationship Re(450) < Re(550) < Re(650). Re(450) / Re(550) of the second 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.

[0024] B. Optical laminate with an adhesive layer According to another aspect of the present invention, an optical laminate with an adhesive layer is provided. The optical laminate with an adhesive layer according to an embodiment of the present invention can be used for the display system described in section A. FIGS. 2(a) and (b) are schematic cross-sectional views showing the schematic configuration of an example of the optical laminate with an adhesive layer.

[0025] The optical laminate 200a with an adhesive layer illustrated in FIG. 2(a) includes an optical laminate 100a including a polarizing member 10, a first phase difference member 20, and a protective member 30 in this order, and an adhesive layer 110 disposed on the surface of the polarizing member 10 side. In the optical laminate 100a, the first phase difference member 20 includes only the first λ / 4 member 20a as the phase difference member. Therefore, the first phase difference member 20 corresponds to the first λ / 4 member. The polarizing member 10 can correspond to the polarizing member included in the display element (for example, a liquid crystal display or an organic EL display) of the display system described in section A. Therefore, the angle formed by the absorption axis of the polarizing member 10 and the slow axis of the first λ / 4 member 20a is, as described above, for example, 40° to 50°, may be 42° to 48°, or may be about 45°. The polarizing member 10, the first phase difference member 20, and the protective member 30 are laminated via an adhesive layer (not shown). The adhesive layer is typically an adhesive layer or a tacky adhesive layer, and preferably a tacky adhesive layer. The thickness of the adhesive layer is, for example, 0.05 μm to 30 μm.

[0026] The pressure-sensitive adhesive layer-attached optical laminate 200b illustrated in FIG. 2(b) includes an optical laminate 100b including a polarizing member 10, a first phase difference member 20, and a protective member 30, in this order, and a pressure-sensitive adhesive layer 110 disposed on the surface of the polarizing member 10 side. The pressure-sensitive adhesive layer-attached optical laminate 200b differs from the pressure-sensitive adhesive layer-attached optical laminate 200a in that the first phase difference member 20 includes, in addition to a 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 are typically laminated via an adhesive layer (not shown). As illustrated, the first λ / 4 member 20a is preferably positioned closer to the polarizing member 10 than the first positive C plate 20b, but their arrangement may be reversed.

[0027] A second release liner 320 is temporarily attached to the surface of the pressure-sensitive adhesive layer-attached optical laminates 200a, 200b on the side of the pressure-sensitive adhesive layer 110. By peeling the second release liner 320 from the pressure-sensitive adhesive layer-attached optical laminates 200a, 200b and bonding the pressure-sensitive adhesive layer-attached optical laminates 200a, 200b to a member constituting the display element 12 using the exposed pressure-sensitive adhesive layer 110, a display system 2 in which the display element 12 and the first retardation member 20 are integrated can be obtained.

[0028] As shown in the illustrated example, a second surface protective film 360 may be further temporarily attached to the surface of the pressure-sensitive adhesive layer-attached optical laminates 200a, 200b facing the protective member 30. This makes it possible to suitably protect the surface of the pressure-sensitive adhesive layer-attached optical laminates 200a, 200b facing the protective member 30.

[0029] The thickness of the optical laminates 100a and 100b is, for example, 50 μm or more and 500 μm or less, and preferably 100 μm or more and 200 μm or less.

[0030] Hereinafter, each of the members constituting the pressure-sensitive adhesive layer-attached optical laminate will be specifically described.

[0031] <Polarizing components> The polarizing element 10 is typically an absorptive polarizing element 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 attached 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.

[0032] 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.

[0033] 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: Ts, Tp, and Tc are Y values ​​measured using a 2-degree visual field (C light source) according to JIS Z8701 and corrected for luminosity. Polarization degree P(%)={(Tp-Tc) / (Tp+Tc)} 1 / 2 ×100

[0034] 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 10 μm or less, or 8 μm or less, or may be 5 μm or less.

[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, 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 dyeing and underwater stretching. 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 protective layer is formed of any suitable 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. Also included are thermosetting or ultraviolet-curable resins such as (meth)acrylic resins, urethane resins, (meth)acrylic urethane resins, epoxy resins, and silicone resins. The term "(meth)acrylic resin" refers to an acrylic resin and / or a methacrylic resin. 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 for this film include resin compositions containing a thermoplastic resin with substituted or unsubstituted imide groups in its side chains and a thermoplastic resin with substituted or unsubstituted phenyl and nitrile groups in its side chains. Examples include 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.

[0040] 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, more preferably 15 μm to 35 μm.

[0041] <First λ / 4 member> The in-plane retardation Re(550) of the first λ / 4 member 20a 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. The first λ / 4 member preferably exhibits an inverse-dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light. Re(450) / Re(550) of the first 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.

[0042] The first λ / 4 member 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 first λ / 4 member is preferably 0.9 to 3, more preferably 0.9 to 2.5, still more preferably 0.9 to 1.5, and particularly preferably 0.9 to 1.3.

[0043] The first λ / 4 member is formed of any suitable material that can satisfy the above characteristics. The first λ / 4 member can be, for example, a stretched film of a resin film or an alignment cured layer of a liquid crystal compound.

[0044] 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 first λ / 4 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.

[0045] 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 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 of these publications are incorporated herein by reference.

[0046] 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.

[0047] The above-mentioned liquid crystal compound alignment / solidification 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 / solidification layer" encompasses an alignment / solidification 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.

[0048] 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.

[0049] 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.

[0050] 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 crosslinking treatment.

[0051] 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.

[0052] 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.

[0053] <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" encompasses 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.

[0054] The positive C plate can be formed of 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.

[0055] <Protective materials> The protective member 30 typically includes a substrate. The substrate can be made 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-based, 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.

[0056] The protective member preferably has a substrate and a surface treatment layer formed on the substrate. The protective member having the surface treatment layer can be arranged 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. The surface treatment layer can 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.

[0057] 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. In one embodiment, the antireflection layer is provided on the outermost surface of the protective member. According to an embodiment in which the antireflection layer is provided on the outermost surface of the protective member, an excellent antireflection effect can be obtained in a display system in which a space is formed between the half mirror 18 and the first retardation member 20.

[0058] 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.

[0059] <Adhesive layer> The adhesive layer 110 is composed of any appropriate adhesive. The adhesive constituting the adhesive layer 110 typically contains a (meth)acrylic polymer, a urethane polymer, a silicone polymer, or a rubber polymer as a base polymer. Preferably, the adhesive is a (meth)acrylic adhesive containing a (meth)acrylic polymer as a main component.

[0060] The (meth)acrylic polymer contains structural units derived from alkyl (meth)acrylate. The content of the structural units derived from alkyl (meth)acrylate in the (meth)acrylic polymer is typically 50% by weight or more, for example, 80% by weight or more, preferably 90% by weight or more, more preferably 93% by weight or more, and for example, 100% by weight or less, preferably 98% by weight or less.

[0061] The alkyl group in the alkyl (meth)acrylate may be linear or branched. The number of carbon atoms in the alkyl group is, for example, 1 or more and 18 or less. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a 2-ethylhexyl group, a decyl group, an isodecyl group, and an octadecyl group. The alkyl (meth)acrylates may be used alone or in combination. The average number of carbon atoms in the alkyl group is preferably 3 to 10.

[0062] The (meth)acrylic polymer may contain, in addition to the structural unit derived from the alkyl (meth)acrylate, a structural unit derived from a copolymerizable monomer polymerizable with the alkyl (meth)acrylate. Examples of the copolymerizable monomer include a carboxyl group-containing monomer, a hydroxyl group-containing monomer, and a nitrogen-containing monomer. The copolymerizable monomers can be used alone or in combination.

[0063] The carboxyl group-containing monomer is a compound that contains a carboxyl group in its structure and a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Examples of the carboxyl group-containing monomer include (meth)acrylic acid, carboxyethyl (meth)acrylate, maleic acid, fumaric acid, and crotonic acid, and preferably (meth)acrylic acid. When the (meth)acrylic polymer contains a structural unit derived from the carboxyl group-containing monomer, the adhesive properties of the pressure-sensitive adhesive layer can be improved. When the (meth)acrylic polymer contains a structural unit derived from the carboxyl group-containing monomer, the content of the structural unit derived from the carboxyl group-containing monomer in the (meth)acrylic polymer is preferably 0.01% by weight or more and 10% by weight or less.

[0064] The hydroxyl group-containing monomer is a compound containing a hydroxyl group in its structure and a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)-methyl acrylate. Preferred examples include 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate, and more preferred examples include 2-hydroxyethyl (meth)acrylate. When the (meth)acrylic polymer contains a structural unit derived from a hydroxyl group-containing monomer, the durability of the pressure-sensitive adhesive layer can be improved. When the (meth)acrylic polymer contains a structural unit derived from a hydroxyl group-containing monomer, the content of the structural unit derived from the hydroxyl group-containing monomer in the (meth)acrylic polymer is preferably 0.01% by weight or more and 10% by weight or less.

[0065] Examples of nitrogen-containing monomers include nitrogen-containing vinyl monomers and cyanoacrylate monomers. Examples of nitrogen-containing vinyl monomers include N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole, vinylmorpholine, (meth)acryloylmorpholine, N-vinylcarboxylic acid amides, and N-vinylcaprolactam. Examples of cyanoacrylate monomers include acrylonitrile and methacrylonitrile. When the (meth)acrylic polymer contains a structural unit derived from a nitrogen-containing monomer, the content of the structural unit derived from the nitrogen-containing monomer in the (meth)acrylic polymer is preferably 0.01% by weight or more and 10% by weight or less.

[0066] The weight average molecular weight Mw of the (meth)acrylic polymer is, for example, 1,000,000 to 3,000,000, and preferably 1,200,000 to 2,500,000.

[0067] The content of the (meth)acrylic polymer in the pressure-sensitive adhesive is, for example, 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more, and even more preferably 80% by weight or more, in terms of solid content. The upper limit of the content can be, for example, 99.9% by weight or less, preferably 99.8% by weight or less.

[0068] The (meth)acrylic adhesive may also contain a crosslinking agent. Typical examples of the crosslinking agent include organic crosslinking agents and polyfunctional metal chelates, with organic crosslinking agents being preferred. Examples of the organic crosslinking agent include isocyanate crosslinking agents, peroxide crosslinking agents, epoxy crosslinking agents, and imine crosslinking agents, with isocyanate crosslinking agents being more preferred. When the adhesive contains a crosslinking agent, the crosslinking agent content is typically 0.01 to 15 parts by weight, for example, 0.1 to 10 parts by weight, per 100 parts by weight of the (meth)acrylic polymer.

[0069] The (meth)acrylic pressure-sensitive adhesive may contain, as necessary, a solvent or various additives, such as a polymerization initiator, a polymerization catalyst, a crosslinking catalyst, a silane coupling agent, a tackifier, a plasticizer, a softener, an antidegradant, a filler, a colorant, an ultraviolet absorber, an antioxidant, a surfactant, an antistatic agent, etc., within a range that does not impair the properties of the present invention.

[0070] The thickness of the pressure-sensitive adhesive layer 110 is, for example, 12 μm or more, preferably 15 μm or more, and for example, 100 μm or less, preferably 80 μm or less.

[0071] C. Method for producing an optical laminate with a pressure-sensitive adhesive layer According to another aspect of the present invention, there is provided a method for producing a pressure-sensitive adhesive layer-attached optical laminate. According to the method for producing a pressure-sensitive adhesive layer-attached optical laminate according to an embodiment of the present invention, the pressure-sensitive adhesive layer-attached optical laminate described in section B can be suitably produced. A method for producing a pressure-sensitive adhesive layer-attached optical laminate according to an embodiment of the present invention includes: Step A of obtaining a pressure-sensitive adhesive layer-attached optical laminate in which a second release liner is disposed on the surface of the pressure-sensitive adhesive layer; and Step B of inspecting the pressure-sensitive adhesive layer-attached optical laminate in a state where the second release liner is placed on the surface of the pressure-sensitive adhesive layer; Including, Step A includes replacing the first release liner arranged on the surface of the pressure-sensitive adhesive layer with a release liner with a surface protective film having a second release liner and a surface protective film arranged on one side of the second release liner, and then peeling off the surface protective film. According to the method for producing a pressure-sensitive adhesive layer-attached optical laminate according to an embodiment of the present invention, step A includes replacing the first release liner with the second release liner, and the second release liner can be protected with a surface protective film until immediately before step B. As a result, foreign matter adhering to the surface of the release liner is prevented from being erroneously detected as a defect in the pressure-sensitive adhesive layer-attached optical laminate in the inspection in step B, and a high-quality pressure-sensitive adhesive layer-attached optical laminate can be suitably produced. In this specification, a release liner is a film that does not itself have adhesive properties and is placed (laminated) on the surface of an adhesive layer to protect the adhesive layer, and a surface protection film is a film that has an adhesive surface on at least one side and is attached to an adherend via the adhesive surface to protect the adherend.

[0072] C-1.Process A In step A, a pressure-sensitive adhesive layer-attached optical laminate is obtained in which a second release liner is disposed on the surface of the pressure-sensitive adhesive layer. Figure 3 is a schematic view illustrating one embodiment of step A. In the embodiment shown in FIG. 3, step A comprises: A step A-1a of preparing a first intermediate film 410 having a pressure-sensitive adhesive layer 110 and a first release liner 310 disposed on the surface of the pressure-sensitive adhesive layer 110; A step A-2a of peeling the first release liner 310 from the first intermediate film 410 and laminating a release liner with a surface protective film 350 having a second release liner 320 and a surface protective film 330 disposed on one side of the second release liner 320 to the exposed pressure-sensitive adhesive layer 110 to obtain a second intermediate film 420; A step A-3a of laminating a third intermediate film 430 on the side of the second intermediate film 420 opposite to the side on which the release liner 350 with the surface protective film is disposed to obtain a fourth intermediate film 440; and A step A-4a of peeling the surface protection film 330 from the fourth intermediate film 440; Includes: In one embodiment, the first intermediate film and the second intermediate film may be formed in a long shape. The long second intermediate film may be cut or punched to a predetermined size to form a sheet of film before step A-3a, and then laminated with a similarly formed third intermediate film in step A-3a. This embodiment is preferable when the first intermediate film has a polarizing element and the third intermediate film has a first λ / 4 element, since it is easy to precisely control the axial relationship between the two. Furthermore, in this embodiment, foreign matter is likely to adhere to the surface protective film during cutting or punching into sheet films. However, by peeling and removing the surface protective film in step A-4a, it is possible to effectively prevent foreign matter from being introduced into the inspection in step B. In this specification, the term "long shape" refers to a long, narrow shape whose length is sufficiently longer than its width, and includes, for example, a long, narrow shape whose length is 10 times or more, preferably 20 times or more, the width.

[0073] C-1-1. Process A-1a In step A-1a, a first intermediate film is prepared, which has a pressure-sensitive adhesive layer and a first release liner disposed on the surface of the pressure-sensitive adhesive layer. As shown in FIG. 3(a), the first intermediate film 410 may have a polarizing member 10, a pressure-sensitive adhesive layer 110, and a first release liner 310, in that order. The polarizing member and the pressure-sensitive adhesive layer are as described in section B. The first intermediate film may contain other components as long as the effects of the present invention are obtained.

[0074] The first release liner 310 protects the PSA layer 110. The first release liner 310 is formed of any appropriate resin film. Specific examples of resins that form the main component of the resin film include polyolefin, polyester, acrylic, polyamide, polyimide, polyvinyl chloride, polyvinylidene chloride, cellulose, modified cellulose, polystyrene, and polycarbonate. Examples of polyolefins include polyethylene, polypropylene, cycloolefin polymer (COP), poly-1-butene, poly-4-methyl-1-pentene, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-vinyl alcohol copolymer. Examples of polyesters include polyethylene terephthalate (PET), polyethylene naphthalate, and polybutylene terephthalate. Examples of polyamides include polyamide 6, polyamide 6,6, and partially aromatic polyamide. Examples of modified celluloses include triacetyl cellulose (TAC). From the viewpoint of obtaining heat resistance that can withstand the application and drying of the pressure-sensitive adhesive, the resin film preferably contains PET, COP, etc. The resin film materials can be used alone or in combination. Furthermore, the resin film may contain a filler from the viewpoint of improving heat resistance, mechanical strength, etc.

[0075] A release treatment layer may be provided on the surface of the first release liner 310 that comes into contact with the pressure-sensitive adhesive layer 110. Examples of release treatment agents that form the release treatment layer include silicone-based release treatment agents, fluorine-based release treatment agents, and long-chain alkyl acrylate-based release treatment agents. The release treatment agents can be used alone or in combination. The thickness of the release treatment layer is typically 50 nm or more and 400 nm or less.

[0076] The thickness of first release liner 310 is typically 5 μm or more, preferably 20 μm or more, and typically 60 μm or less, preferably 45 μm or less. If a release-treated layer is provided, the thickness of the first release liner includes the thickness of the release-treated layer.

[0077] First release liner 310 does not need to have high transparency because it is peeled off and removed before inspection. The total light transmittance of the first release liner may be, for example, 95% or less, or, for example, 90% or less or 80% or less, with no particular lower limit and may be, for example, 50% or more.

[0078] The peel strength of first release liner 310 from adhesive layer 110 (peel angle 180°, peel speed 300 mm / min) is, for example, 0.001 N / 50 mm or more, preferably 0.004 N / 50 mm or more, and for example, 0.5 N / 50 mm or less, preferably 0.1 N / 50 mm or less.

[0079] The first intermediate film 410 can be obtained by any appropriate method. In one embodiment, the first intermediate film 410 can be obtained by a method including preparing a laminate of a first release liner 310 and a pressure-sensitive adhesive layer 110, and bonding the laminate to a polarizing member 10 via the pressure-sensitive adhesive layer 110. For example, the pressure-sensitive adhesive layer 110 can be formed by applying a pressure-sensitive adhesive to the first release liner 310 and drying the applied layer. The first intermediate film 410 can be obtained by bonding the resulting laminate of the first release liner 310 and the pressure-sensitive adhesive layer 110 to the polarizing member 10 via the pressure-sensitive adhesive layer 110. Alternatively, the first intermediate film 410 can be obtained by applying a pressure-sensitive adhesive to a substrate and drying the applied layer to form the pressure-sensitive adhesive layer 110, transferring the pressure-sensitive adhesive layer to the first release liner 310, and then bonding the resulting laminate to the polarizing member 10.

[0080] The drying temperature of the coating layer is preferably 40°C or higher, for example, 50°C or higher, 70°C or higher, 100°C or higher, or 130°C or higher, for example, 200°C or lower. The drying time is, for example, 5 seconds or higher, preferably 10 seconds or higher, for example, 1200 seconds or lower. When the PSA contains a crosslinking agent, the crosslinking reaction can be sufficiently promoted during the drying. When a PSA layer is formed by applying a PSA to a release liner with a surface protective film, the heat during drying can cause the surface protective film to deteriorate (denaturation, deformation, etc.). In contrast, according to the method for producing an optical laminate with a PSA layer according to an embodiment of the present invention, the release liner with a surface protective film is bonded to a PSA layer separately formed on a substrate (e.g., a first release liner), and therefore the problem of deterioration of the surface protective film does not occur.

[0081] C-1-2. Process A-2a In step A-2a, as shown in Figures 3(b) and (c), the first release liner 310 is peeled off from the first intermediate film 410, and a release liner with a surface protective film 350 having a second release liner 320 and a surface protective film 330 disposed on one side thereof is bonded to the exposed adhesive layer 110 to obtain a second intermediate film 420.

[0082] Peeling of first release liner 310 from first intermediate film 410 is carried out, for example, using a film peeling device. The bonding of release liner 350 with surface protective film is preferably carried out consecutively with the peeling of first release liner 310. By bonding the release liner with surface protective film immediately after peeling of the first release liner, adhesion of foreign matter to the surface of the PSA layer can be suitably prevented.

[0083] The second release liner 320 is formed of any appropriate resin film. Specific examples of the resin that is the main component of the resin film include those listed for the first release liner. From the viewpoint of achieving high transparency suitable for defect inspection, the resin film preferably contains COP, PET, or the like. The resin film materials can be used alone or in combination.

[0084] The resin film preferably does not contain or substantially does not contain filler. Such a resin film has excellent transparency and reduces false detection of defects caused by filler. Note that "a resin film substantially does not contain filler" means that the filler content in the resin film is 0.05 wt% or less. Furthermore, if the resin film contains filler, the filler is preferably a nanofiller (nanofiller refers to particles with a maximum length of 100 nm or less).

[0085] A release-treated layer may be provided on the surface of second release liner 320 that comes into contact with PSA layer 110. The same explanation as for the first release liner applies to the release treatment agent that forms the release-treated layer and the thickness of the release-treated layer.

[0086] The thickness of the second release liner 320 can be determined in the same manner as for the first release liner.

[0087] Since the second release liner 320 is subjected to inspection together with the pressure-sensitive adhesive layer-attached optical laminate, it is preferable that the second release liner 320 has excellent transparency. The total light transmittance of the second release liner is, for example, 80% or more, preferably 90% or more, more preferably 95% or more, and even more preferably 97% or more.

[0088] The peel force of the second release liner 320 from the pressure-sensitive adhesive layer 110 (peel angle 180°, peel speed 300 mm / min) is, for example, 0.01 N / 50 mm or more, preferably 0.02 N / 50 mm or more, more preferably 0.04 N / 50 mm or more, and for example, 0.5 N / 50 mm or less, preferably 0.2 N / 50 mm or less, more preferably 0.1 N / 50 mm or less. If the peel force is less than 0.01 N / 50 mm, the second release liner may peel off when the surface protective film is peeled off in step A-4a. If the peel force exceeds 0.5 N / 50 mm, the ease of peeling the second release liner may decrease when the pressure-sensitive adhesive layer-attached optical laminate is used.

[0089] The surface protection film 330 prevents foreign matter from adhering to the surface of the second release liner until the second release liner together with the adhesive layer-attached optical laminate is subjected to inspection.

[0090] The peel force (adhesive force) of the surface protection film 330 with respect to the second release liner 320 (peel angle 180°, peel speed 300 mm / min) is, for example, 0.005 N / 50 mm or more, preferably 0.007 N / 50 mm or more, more preferably 0.01 N / 50 mm or more, and for example, 0.095 N / 50 mm or less, preferably 0.07 N / 50 mm or less, more preferably 0.05 N / 50 mm or less. If the peel force of the surface protection film with respect to the second release liner is less than 0.005 N / 50 mm, when attaching the release liner 350 with the surface protection film to the adhesive layer 110 in step A-2a, the surface protection film 330 may float from the second release liner 320. If the peel force of the surface protection film 330 with respect to the second release liner 320 exceeds 0.095 N / 50 mm, when peeling the surface protection film 330 in step A-4a, the second release liner 320 may also be peeled off together.

[0091] The peel force X (peel angle 180°, peel speed 300 mm / min) of the surface protection film 330 with respect to the second release liner 320 and the peel force Y (peel angle 180°, peel speed 300 mm / min) of the second release liner 320 with respect to the adhesive layer 110 satisfy, for example, the relationship of 0.2 < X / Y < 1, preferably satisfy the relationship of 0.25 < X / Y < 0.7. Thereby, the problem of the surface protection film floating in step A-2a and the problem of the second release liner peeling in step A-4a can be preferably prevented.

[0092] Since the surface protection film 330 is peeled off before inspection, it does not need to have high transparency. The total light transmittance of the surface protection film may be, for example, 95% or less, or for example, 90% or less or 80% or less, and its lower limit value is not particularly limited and may be, for example, 60% or more.

[0093] For example, a film that can be attached to an adherend by its own adhesiveness without using adhesive or other adhesive means (hereinafter referred to as a self-adhesive film) can be used as the surface protection film 330. A self-adhesive film can preferably obtain the above-mentioned peel strength.

[0094] Typically, a polyolefin film is used as the self-adhesive film. Specifically, the self-adhesive film is preferably made of polyethylene, polypropylene, or a mixture thereof. Here, polyethylene includes ethylene homopolymers and copolymers of ethylene and other olefins. Polypropylene includes propylene homopolymers and copolymers of propylene and other olefins.

[0095] Specific examples of the polyethylene include high density polyethylene (HDPE), low density polyethylene (LDPE), and linear low density polyethylene (L-LDPE).

[0096] Examples of the other olefin include ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, and decene. Among these, ethylene, propylene, and butene are preferably used. In preparing a copolymer of ethylene or propylene with the other olefin, the blending ratio of the other olefin is preferably 40 parts by weight or less, more preferably 30 parts by weight or less, and even more preferably 20 parts by weight or less, per 100 parts by weight of the total of ethylene or propylene and the other olefin.

[0097] In one embodiment, the polyolefin film preferably contains polyethylene. Specifically, the polyolefin film is preferably a polyethylene film or a mixture film of polyethylene and polypropylene. When the polyolefin film contains a mixture of polyethylene and polypropylene, the content of polyethylene is preferably 60 parts by weight or more and 97 parts by weight or less, more preferably 70 parts by weight or more, and even more preferably 80 parts by weight or more, per 100 parts by weight of the total of polyethylene and polypropylene.

[0098] The self-adhesive film (polyolefin film) may contain other ingredients such as particles, pigments, colorants, antistatic agents, ultraviolet absorbers, antioxidants, heat stabilizers, and chlorine scavengers.

[0099] The self-adhesive film (polyolefin film) may be a single layer with a uniform composition, or may have a laminated structure of two or more layers with different compositions. Specific examples of the laminated structure include a two-layer structure with a first layer and a second layer with different compositions, and a three-layer structure with a first layer, a second layer, and a third layer. The first layer and the third layer may have substantially the same composition or different compositions. The self-adhesive film (polyolefin film) may be a non-stretched film or a stretched film, but is preferably a non-stretched film.

[0100] The surface roughness Ra of the self-adhesive film (surface roughness Ra before being attached to the second release liner) is, for example, 0.05 μm or more and 0.5 μm or less.

[0101] The thickness of the self-adhesive film is preferably 15 μm to 60 μm, and more preferably 20 μm to 50 μm.

[0102] Examples of materials for forming the substrate of the pressure-sensitive adhesive film include polyester polymers such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; cellulose polymers such as diacetyl cellulose and triacetyl cellulose; polycarbonate polymers; (meth)acrylic polymers such as polymethyl methacrylate; and cycloolefin polymers such as polynorbornene. These may be used alone or in combination of two or more.

[0103] Any appropriate adhesive may be used for the adhesive layer of the adhesive film. Specific examples include acrylic adhesives, rubber adhesives, silicone adhesives, polyester adhesives, urethane adhesives, epoxy adhesives, and polyether adhesives. By adjusting the type, number, combination, and compounding ratio of monomers forming the base resin of the adhesive, as well as the amount of crosslinking agent, reaction temperature, reaction time, and the like, it is possible to prepare an adhesive having desired properties according to the intended purpose. The base resin of the adhesive may be used alone or in combination of two or more types. The base resin is preferably an acrylic resin (specifically, the adhesive layer is preferably composed of an acrylic adhesive). For details on acrylic adhesives, see, for example, JP 2013-79360 A and JP 2019-127526 A. The thickness of the adhesive layer is, for example, 5 μm to 30 μm, preferably 5 μm to 20 μm, and more preferably 5 μm to 15 μm.

[0104] The release liner 350 with surface protective film can be obtained, for example, by laminating the surface protective film 330 and the second release liner 320 (e.g., roll-to-roll lamination). When a self-adhesive film is used as the surface protective film, the peel strength of the self-adhesive film from the second release liner can be adjusted (e.g., increased) by laminating the self-adhesive film and the second release liner 320 and then heating the laminate. The treatment temperature is, for example, 40°C or higher, preferably 45°C or higher, and, for example, 60°C or lower, preferably 55°C or lower. The treatment time may be any time that provides the desired release strength, and is, for example, 600 minutes or higher, preferably 1200 minutes or higher, and, for example, 48 hours or shorter, preferably 36 hours or shorter. The heating treatment is preferably performed while pressure is applied to the release liner with surface protective film. For example, the effect of increasing the release strength can be suitably achieved by heating a release liner with surface protective film wound into a roll.

[0105] C-1-3. Process A-3a 3(d) and (e), a third intermediate film 430 is laminated on the side of the second intermediate film 420 opposite to the side on which the release liner 350 with the surface protective film is disposed, to obtain a fourth intermediate film 440. The second intermediate film and the third intermediate film are typically bonded together with an adhesive layer (e.g., a pressure-sensitive adhesive layer).

[0106] The third intermediate film 430 may include a first retardation member 20 and a protective member 30. In the illustrated example, the third intermediate film 430 further includes a second surface protective film 360 on the side of the protective member 30 opposite the side on which the first retardation member 20 is disposed. By including the second surface protective film in the third intermediate film, the surface on the protective member side can be suitably protected. The second surface protective film may be configured by laminating two or more surface protective films. The surface protective film used for the second surface protective film may be the same as that described in Section C-1-2. The first retardation member and the protective member are as described in Section B. Although not illustrated, the third intermediate film may preferably further include an adhesive layer on the side of the first retardation member opposite the side on which the protective member is disposed. By including an adhesive layer in the third intermediate film, lamination to the second intermediate film can be easily performed. The second intermediate film having a polarizing element and the third intermediate film having a first λ / 4 element can be laminated so that the absorption axis of the polarizing element and the slow axis of the first λ / 4 element are at an angle of, for example, 40° to 50°, 42° to 48°, or approximately 45°.

[0107] The third intermediate film can be obtained by laminating each component, optionally via an adhesive layer. The order in which each component is laminated is not limited. For example, the third intermediate film can be obtained by a method including laminating a first λ / 4 component and a positive C plate via an adhesive layer (e.g., an adhesive layer) to obtain a first retardation component, and laminating a protective component on one side of the first retardation component via an adhesive layer (e.g., a pressure-sensitive adhesive layer). If necessary, a pressure-sensitive adhesive layer may be laminated on the other side of the first retardation component, or a second surface protective film may be attached to the surface of the protective component.

[0108] C-1-4. Process A-4a In step A-4a, as shown in FIG. 3(f), the surface protection film 330 is peeled off from the fourth intermediate film 440. This results in an adhesive-layer-attached optical laminate 450 (sometimes referred to as an "adhesive-layer-attached optical laminate of inspection configuration") in which a second release liner is disposed on the surface of the adhesive layer. The adhesive-layer-attached optical laminate 450 of inspection configuration is, for example, chucked at the edge and subjected to inspection. By peeling off the surface protection film 330 and subjecting the laminate to inspection immediately, it is possible to suitably prevent foreign matter from being introduced into the inspection.

[0109] The pressure-sensitive adhesive layer-attached optical laminate 450 in the inspection configuration shown in the figure has the second surface protective film 360 laminated on the protective member 30 side, but may be subjected to inspection after peeling off the second surface protective film 360. When the second surface protective film 360 includes two or more surface protective films, the outer surface protective film may be peeled off and the inner surface protective film may be laminated and subjected to inspection in that state.

[0110] C-1-5. Modification of Process A Step A is not limited to the above embodiment as long as a pressure-sensitive adhesive layer-attached optical laminate in which a second release liner is disposed on the surface of the pressure-sensitive adhesive layer can be obtained. For example, in the above embodiment, the third intermediate film has a first retardation member and a protective member, but an intermediate film having a first retardation member and an intermediate film having a protective member may be prepared separately and then laminated sequentially on the first intermediate film.

[0111] In another embodiment, step A comprises the steps of: A step A-1b of preparing a fifth intermediate film 460 having a pressure-sensitive adhesive layer-attached optical laminate 200 having an optical laminate 100 and a pressure-sensitive adhesive layer 110 disposed on one side of the optical laminate 100, and a first release liner 310 disposed on the surface of the pressure-sensitive adhesive layer-attached optical laminate 200 on the pressure-sensitive adhesive layer 110 side; A step A-2b of peeling the first release liner 310 from the fifth intermediate film 460; A step A-3b of laminating a release liner with a surface protective film (350) having a second release liner (320) and a surface protective film (330) disposed on one side thereof to the pressure-sensitive adhesive layer-attached optical laminate (200) so that the second release liner (320) is in contact with the release surface, thereby obtaining a sixth intermediate film (470); and A step A-4b of peeling the surface protection film 330 from the sixth intermediate film 470; may include: In this embodiment, the pressure-sensitive adhesive layer-attached optical laminate 200 can be obtained by stacking each member in any appropriate order. For example, the pressure-sensitive adhesive layer-attached optical laminate can be produced by roll-to-roll production using a long polarizing member having an absorption axis in the longitudinal direction or width direction and a long first λ / 4 member having a slow axis oblique to the longitudinal direction, or a long polarizing member having an absorption axis oblique to the longitudinal direction and a long first λ / 4 member having a slow axis in the longitudinal direction or width direction. From the viewpoint of optimally obtaining the effects of the present invention, also in this embodiment, it is preferable that the peel force X of the surface protection film to the second release liner, the peel force Y of the second release liner to the pressure-sensitive adhesive layer, and the ratio of the peel force X to the peel force Y are within the above-mentioned ranges.

[0112] C-2.Process B In step B, the pressure-sensitive adhesive layer-attached optical laminate is inspected with the second release liner disposed on the surface of the pressure-sensitive adhesive layer. In other words, the pressure-sensitive adhesive layer-attached optical laminate 450 is inspected using the inspection configuration described above. For example, the pressure-sensitive adhesive layer-attached optical laminate is inspected for defects, and the pressure-sensitive adhesive layer-attached optical laminate is judged as a good product or a defective product. The defect inspection is performed using any appropriate defect inspection device. As the defect inspection device, a known defect inspection device can be used, and an automated optical inspection (AOI) device is preferably used. Examples of literature describing defect inspection devices include WO 2011 / 148790, JP 2003-344302 A, JP 2011-226957 A, JP 2016-70856 A, and JP 2021-135219 A. The defect inspection may further include a visual inspection, if necessary. The number of foreign matter particles having a diameter of 10 μm or more adhering to the surface of the second release liner of the pressure-sensitive adhesive layer-attached optical laminate in the inspection configuration is, for example, 300 or less per sheet, preferably 200 or less per sheet, and more preferably 100 or less per sheet. The size of the pressure-sensitive adhesive layer-attached optical laminate in the inspection configuration is not particularly limited, but may be, for example, 20,000 mm 2 or more, for example, 50,000 mm 2 For example, 100,000 mm 2 Below, for example, 70,000 mm 2 The following is the result.

[0113] 5, the effective inspection range on the main surface of the pressure-sensitive adhesive layer-attached optical laminate 450 in the inspection configuration is divided into a plurality of virtual areas E based on the size of the final product, and the presence or absence of defects is inspected in the plurality of virtual areas E. The size of the defects to be inspected is typically 5 μm or more and 300 μm or less, 5 μm or more and 200 μm or less, or 5 μm or more and 100 μm or less. Next, if the proportion of virtual areas E that contain defects (number of virtual areas that contain defects / total number of virtual areas × 100; hereinafter referred to as the defect occupancy rate) is within a specified range, the product is judged to be good, and if it is outside the specified range, the product is judged to be defective. The upper limit of the defect occupancy is a criterion for determining whether a product is good or bad, and is, for example, 10% or less, preferably 5% or less. The lower limit of the defect occupancy is, for example, 0% or more. When the criteria for determining whether a product is good or bad are set at the upper limit values ​​described above, the rate at which defective final products are manufactured can be further reduced. The pressure-sensitive adhesive layer-attached optical laminate determined to be a defective product may be rejected (typically discarded).

[0114] The pressure-sensitive adhesive layer-attached optical laminate determined to be a non-defective product in the above inspection is sent to, for example, a punching process, where it is punched to a predetermined size. This results in a pressure-sensitive adhesive layer-attached optical laminate piece (more specifically, a pressure-sensitive adhesive layer-attached optical laminate piece in which the pressure-sensitive adhesive layer is protected by the second release liner) as the final product. The punching is typically performed along the dividing lines of multiple imaginary areas in the inspection. [Example]

[0115] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The thicknesses are values ​​measured by the following measurement method. <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"). <Total light transmittance> Measurement was carried out using a spectrophotometer (Hitachi High-Tech Science Corporation, product name "U4100"). <Peeling force> [Release liner with surface protection film 1-4] (1-1) Peel strength of surface protection film to second release liner A laminate of the first release liner obtained in Production Example 6 and the pressure-sensitive adhesive layer 1 formed on one side thereof was bonded to a SUS plate (SUS304BA) via the pressure-sensitive adhesive layer 1, and then the first release liner was peeled off to expose the pressure-sensitive adhesive layer 1. A release liner with a surface protective film cut to a size of 50 mm × 150 mm was attached to this laminate so that the surface of the second release liner was in contact with the pressure-sensitive adhesive layer 1. The peel force was measured using a universal tensile tester (manufactured by Minebea Co., Ltd., product name: TCM-1kNB) in an environment of 23°C and 65% RH, at a peel rate of 300 mm / min and a peel angle of 180° when the surface protective film was peeled off from the second release liner. (1-2) Peel strength of second release liner from adhesive layer 1 After the measurement in (1-1) above, the peel force was measured when the second release liner was peeled from the pressure-sensitive adhesive layer 1 at a peel speed of 300 mm / min and a peel angle of 180 degrees. [Release liner with surface protection film 5-7] (2-1) Peel strength of surface protection film to secondary release liner The release liner with the surface protective film was cut to a size of 50 mm × 150 mm, and the second release liner side was attached to a SUS plate (SUS304BA) using double-sided tape. The peel force (peel speed 300 mm / min, peel angle 180°) when the surface protective film was peeled from the second release liner was measured in the same manner as in (1-1) above. (2-2) Peel strength of second release liner from adhesive layer 1 In the same manner as in (1-1) above, pressure-sensitive adhesive layer 1 was fixed to a SUS plate (SUS304BA), and a release liner with a surface protective film cut to a size of 50 mm × 150 mm was attached so that the surface of the second release liner was in contact with pressure-sensitive adhesive layer 1. In the same manner as in (1-1) above, the peel force (peel speed 300 mm / min, peel angle 180°) when the release liner with the surface protective film was peeled from pressure-sensitive adhesive layer 1 was measured. <In-plane phase difference> The in-plane retardation at 23° C. was measured using a KOBRA-WPR manufactured by Oji Scientific Instruments.

[0116] [Production Example 1A: Release liner with surface protection film 1] A self-adhesive film (Toray Industries, Inc., "Tretec 7832C," 50 μm thick, with a total light transmittance of 90%) was used as the surface protection film, and a PET film with a release-treated layer (Toray Industries, Inc., "Cerapeel," with a total light transmittance of 92%) was used as the second release liner. A second release liner was laminated on one side (adhesive side) of the surface protective film under pressure bonding conditions of 23.5°C and 3.0 MPa to obtain release liner with surface protective film 1. At this time, the second release liner was laminated so that the side opposite the release-treated layer side faced the surface protective film.

[0117] [Production Example 1B: Release liner with surface protection film 2] A release liner 2 with a surface protective film was obtained in the same manner as in Production Example 1A, except that a self-adhesive film (manufactured by Toray Industries, Inc., "Tretec 7832C", thickness 30 μm, total light transmittance 90%) was used as the surface protective film, and the long laminate obtained by laminating the surface protective film and the second release liner was wound into a roll and heated in a heating chamber at 50°C for 24 hours.

[0118] [Production Example 1C: Release liner with surface protection film 3] A release liner 3 with a surface protective film was obtained in the same manner as in Production Example 1B, except that a self-adhesive film (manufactured by Toray Industries, Inc., "Tretec 7832C", thickness 50 μm, total light transmittance 90%) was used as the surface protective film.

[0119] [Production Example 1D: Release liner with surface protection film 4] A release liner 4 with a surface protective film was obtained in the same manner as in Production Example 1A, except that a self-adhesive film (Toray Industries, Inc., "Tretec 7832C", thickness 30 μm, total light transmittance 90%) was used as the surface protective film.

[0120] [Production Example 1E: Release liner 5 with surface protection film] A release liner 5 with a surface protective film was obtained in the same manner as in Production Example 1A, except that an adhesive film 1 (substrate thickness 38 μm, adhesive layer thickness 20 μm, total light transmittance 89%) having a PET substrate and an acrylic adhesive layer prepared as described below was used as the surface protective film, and a second release liner was laminated on the adhesive layer surface. <Preparation of adhesive film 1> A reaction vessel equipped with a thermometer, stirrer, condenser, and nitrogen gas inlet tube was charged with 100 parts by weight of 2-ethylhexyl acrylate (2EHA) and 4 parts by weight of hexyl acrylate as monomer components, and 0.2 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator, along with 150 parts by weight of ethyl acetate. Nitrogen gas was introduced while gently stirring at 23°C to perform nitrogen substitution. The liquid temperature was then maintained at around 65°C, and a polymerization reaction was carried out for 6 hours to prepare a solution of acrylic polymer A (concentration 40% by weight). The weight-average molecular weight of acrylic polymer A was 530,000. Ethyl acetate was added to the solution of acrylic polymer A to dilute it to a concentration of 20% by weight. To 500 parts by weight of this solution (solid content 100 parts by weight), 4 parts by weight of an isocyanurate of hexamethylene diisocyanate ("Coronate HX" manufactured by Tosoh Corporation) as a crosslinking agent and 0.2 parts by weight of a surfactant ("Aqualon HS-10" manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were added and stirred to prepare PSA composition A. Pressure-sensitive adhesive composition A was applied to the surface (corona-treated surface) of a substrate (PET film, manufactured by Mitsubishi Chemical Corporation, product number T100C38, thickness 38 μm) and then dried to form a pressure-sensitive adhesive layer (thickness 20 μm).

[0121] [Production Example 1F: Release liner with surface protection film 6] A release liner 6 with a surface protection film was obtained in the same manner as in Production Example 1A, except that an adhesive film 2 (substrate thickness 38 μm, adhesive layer thickness 5 μm, total light transmittance 89%) having a PET substrate and an acrylic adhesive layer prepared as described below was used as the surface protection film, and a second release liner was laminated on the adhesive layer surface. <Preparation of adhesive film 2> A reaction vessel equipped with a thermometer, stirrer, condenser, and nitrogen gas inlet tube was charged with 96.2 parts by weight of 2-ethylhexyl acrylate (2EHA) and 3.8 parts by weight of hydroxyethyl acrylate (HEA) as monomer components, and 0.2 parts by weight of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator, along with 150 parts by weight of ethyl acetate. Nitrogen gas was introduced while gently stirring at 23°C to perform nitrogen substitution. The liquid temperature was then maintained at around 65°C, and a polymerization reaction was carried out for 6 hours to prepare a solution of acrylic polymer B (concentration 40% by weight). The weight-average molecular weight of acrylic polymer B was 540,000. Ethyl acetate was added to the solution of acrylic polymer B to dilute it to a concentration of 20% by weight. To 500 parts by weight of this solution (solid content 100 parts by weight), 4 parts by weight of an isocyanurate of hexamethylene diisocyanate ("Coronate HX" manufactured by Tosoh Corporation) as a crosslinking agent and 3 parts by weight (solid content 0.03 parts by weight) of dibutyltin dilaurate (1% by weight ethyl acetate solution) as a crosslinking catalyst were added and stirred to prepare PSA composition B. Pressure-sensitive adhesive composition B was applied to the surface (corona-treated surface) of a substrate (PET film, manufactured by Mitsubishi Chemical Corporation, product number T100C38, thickness 38 μm) and then dried to form a pressure-sensitive adhesive layer (thickness 5 μm).

[0122] [Production Example 1G: Release liner with surface protection film 7] Release liner 7 with surface protective film was obtained in the same manner as in Production Example 1A, except that a second release liner was laminated to the corona-treated surface of a self-adhesive film (Toray Industries, Inc., "Tretec 7832C", thickness 50 μm, total light transmittance 90%) that had been corona-treated on one side.

[0123] [Production Example 2: Polarizing Film 1] A long roll of a 30 μm-thick polyvinyl alcohol (PVA) resin film (manufactured by Kuraray Co., Ltd., product name "PE3000") was uniaxially stretched in the longitudinal direction by 5.9 times using a roll stretching machine, while simultaneously undergoing swelling, dyeing, crosslinking, and washing processes, and finally drying, to produce a 12 μm-thick absorptive polarizing film. Specifically, the film was stretched 2.2 times while being treated with pure water at 20°C for swelling. Then, for dyeing, the film was stretched 1.4 times while being treated in a 30°C aqueous solution containing iodine and potassium iodide at a weight ratio of 1:7, with the iodine concentration adjusted so that the resulting absorptive polarizing film had a single transmittance of 45.0%. Furthermore, a two-stage crosslinking treatment was employed. In the first stage, the film was stretched 1.2 times while being treated in a 40°C aqueous solution containing boric acid and potassium iodide. The boric acid content of the aqueous solution used in the first stage was 5.0 wt % and the potassium iodide content was 3.0 wt %. In the second stage, the film was stretched 1.6 times while being treated in a 65°C aqueous solution containing boric acid and potassium iodide. The boric acid content of the aqueous solution used in the second stage was 4.3 wt % and the potassium iodide content was 5.0 wt %. The film was washed with an aqueous potassium iodide solution at 20°C. The potassium iodide content of the aqueous solution used for the washing treatment was 2.6% by weight. Finally, the film was dried at 70°C for 5 minutes to obtain an absorptive polarizing film. A triacetyl cellulose (TAC) resin film with a hard coat layer (TAC thickness: 25 μm, HC layer thickness: 7 μm) was laminated to one side of the obtained absorptive polarizing film, and a cycloolefin resin film (thickness: 13 μm) was laminated to the other side as a protective layer. Specifically, a curable adhesive was applied so that the total thickness was approximately 1 μm, and the films were laminated using a roller. Then, UV light was irradiated from the TAC film side to cure the adhesive. As a result, a polarizing film 1 (thickness: 57 μm) having a structure of [HC-attached TAC film / absorptive polarizing film / COP film] was obtained.

[0124] [Manufacturing example 3: λ / 4 member 1] 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 weight (0.046 mol) of bis[9-(2-phenoxycarbonylethyl)fluoren-9-yl]methane, 29.21 parts by weight (0.200 mol) of isosorbide (ISB), 42.28 parts by weight (0.139 mol) of spiroglycol (SPG), 63.77 parts by weight (0.298 mol) of diphenyl carbonate (DPC), and 1.19 × 10 calcium acetate monohydrate as a catalyst. -2 Weight part (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.

[0125] The resulting polyester carbonate resin pellets were vacuum-dried at 80°C for 5 hours and then processed into a 135µm-thick, long resin film 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: 200mm, 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 times. This resulted in a 47µm-thick stretched film (λ / 4 member 1). The Re(590) of the λ / 4 member 1 was 143nm, the Re(450) / Re(550) was 0.86, and the Nz coefficient was 1.12.

[0126] [Manufacturing Example 4: Positive C Plate 1] 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 represent the mole percent of the monomer unit, and are conveniently expressed as a block polymer; weight-average molecular weight 5000), 80 parts by weight of a polymerizable liquid crystal exhibiting a nematic liquid crystal phase (BASF: trade name Paliocolor LC242), and 5 parts by weight of a photopolymerization initiator (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 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 it, forming a positive C-plate 1 with a thickness of 4 μm and an Rth(550) of -100 nm on the substrate. [ka]

[0127] [Manufacturing Example 5: Protective Member 1] The anti-reflection layer-forming material shown below was applied to an acrylic film having a lactone ring structure and heated at 80°C for 1 minute. After heating, the coating 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 kJ / cm to form an antireflection layer having a thickness of 4 μm, thereby obtaining a protective member 1 (thickness: 44 μm) having a structure of [acrylic film / antireflection layer].

[0128] (Anti-reflection layer forming material) 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 the mixture was added 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 as a dilution solvent, so that the total solid content was 4% by weight, and the mixture was stirred to prepare an anti-reflection layer-forming material.

[0129] [Production Example 6: Adhesive Layer 1] (Acrylic polymer 1) A four-neck flask equipped with a stirring blade, thermometer, nitrogen gas inlet, and condenser was charged with a monomer mixture containing 80.3 parts butyl acrylate, 16 parts phenoxyethyl acrylate, 3 parts N-vinyl-2-pyrrolidone (NVP), 0.3 parts acrylic acid, and 0.4 parts 4-hydroxybutyl acrylate. Furthermore, 0.1 parts 2,2'-azobisisobutyronitrile as a polymerization initiator and 100 parts ethyl acetate were charged to 100 parts of the above monomer mixture (solids). Nitrogen gas was introduced with gentle stirring to replace the atmosphere. The temperature in the flask was maintained at around 55°C, and the polymerization reaction was carried out for 8 hours to prepare a solution of acrylic polymer 1. The weight-average molecular weight of acrylic polymer 1 was 1.5 million.

[0130] <Adhesive solution 1> Acrylic adhesive solution 1 was prepared by mixing 0.3 parts of benzoyl peroxide (BPO: Niper BMT manufactured by NOF Corporation) as a crosslinking agent with 100 parts by weight of the solid content of the acrylic polymer 1 solution.

[0131] <Adhesive layer 1> The acrylic adhesive solution 1 was applied to the release-treated layer surface of a PET film ("MRF38", manufactured by Mitsubishi Chemical Polyester Film Corporation, total light transmittance 86%) having a release-treated layer as a first release liner, and dried and crosslinked at 155°C for 3 minutes to form an adhesive layer 1 having a thickness of 20 μm after drying on the long first release liner.

[0132] [Example 1] A laminate of the adhesive layer 1 and the first release liner was roll-to-roll bonded to the COP film side of the polarizing film 1 to obtain a long first intermediate film 1 having a structure of [first release liner / adhesive layer 1 / polarizing film 1] (step A-1a). The first release liner was peeled from the first intermediate film 1, and the above-mentioned release liner 1 with surface protective film was laminated to the exposed pressure-sensitive adhesive layer 1 by roll-to-roll bonding, with the second release liner facing the pressure-sensitive adhesive layer 1. The lamination of the release liner 1 with surface protective film was carried out under a nip roll pressure of 3.0 MPa. This yielded a long second intermediate film 1 having a structure of [release liner 1 with surface protective film / pressure-sensitive adhesive layer 1 / polarizing film 1] (step A-2a). The positive C plate 1 was attached to the λ / 4 member 1 via an ultraviolet curing adhesive (thickness after curing: 1 μm), and then the base material was peeled off and removed to obtain a retardation member 1. An acrylic pressure-sensitive adhesive layer (thickness: 15 μm) laminated on a substrate was attached to the λ / 4 member 1 side of the retardation member 1 together with the substrate. Next, the protective member 1 was attached to the positive C plate 1 side of the retardation member 1 via an acrylic pressure-sensitive adhesive layer (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 1 side (in other words, so that the antireflection layer was the outermost surface). The lamination was carried out by roll-to-roll, thereby obtaining a long third intermediate film 1 having a structure of [substrate / acrylic pressure-sensitive adhesive layer / λ / 4 member 1 / positive C plate 1 / protective member 1]. The long second intermediate film 1 and third intermediate film 1 were each punched out to a size of 371.87 mm x 236.58 mm to obtain a sheet of film. The second intermediate film 1 was punched out so that the long side of the sheet of film was parallel to the longitudinal direction. The third intermediate film 1 was punched out so that the long side formed a 45° angle with the longitudinal direction. The substrate was peeled off from a sheet of third intermediate film 1 to expose the acrylic pressure-sensitive adhesive layer, which was then attached to the polarizing member side of a sheet of second intermediate film 1. This resulted in a fourth intermediate film 1 having a configuration of [release liner with surface protective film 1 / pressure-sensitive adhesive layer 1 / polarizing film 1 / λ / 4 member 1 / positive C plate 1 / protective member 1] (step A-3a). In fourth intermediate film 1, the angle between the absorption axis of the absorptive polarizing film and the slow axis of the λ / 4 member 1 was 45°. Next, the surface protective film was peeled off from the fourth intermediate film 1 to obtain an optical laminate with an adhesive layer 1 of the test configuration (specifically, an optical laminate with an adhesive layer having the configuration [second release liner / adhesive layer 1 / polarizing film 1 / λ / 4 member 1 / positive C plate 1 / protective member 1]) (step A-4a).

[0133] [Example 2] An optical laminate 2 with a pressure-sensitive adhesive layer having an inspection configuration was obtained in the same manner as in Example 1, except that a release liner 2 with a surface protective film was used instead of a release liner 1 with a surface protective film.

[0134] [Example 3] An optical laminate 3 with a pressure-sensitive adhesive layer having an inspection configuration was obtained in the same manner as in Example 1, except that a release liner 3 with a surface protective film was used instead of a release liner 1 with a surface protective film.

[0135] [Example 4] An optical laminate 4 with a pressure-sensitive adhesive layer having an inspection configuration was obtained in the same manner as in Example 1, except that a release liner 4 with a surface protective film was used instead of a release liner 1 with a surface protective film.

[0136] [Example 5] An optical laminate 5 with a pressure-sensitive adhesive layer having a test configuration was obtained in the same manner as in Example 1, except that a release liner 5 with a surface protective film was used instead of a release liner 1 with a surface protective film.

[0137] [Example 6] An optical laminate 6 with a pressure-sensitive adhesive layer having a test configuration was obtained in the same manner as in Example 1, except that a release liner 6 with a surface protective film was used instead of a release liner 1 with a surface protective film.

[0138] [Example 7] An optical laminate 7 with a pressure-sensitive adhesive layer having an inspection configuration was obtained in the same manner as in Example 1, except that a release liner 7 with a surface protective film was used instead of a release liner 1 with a surface protective film.

[0139] [Comparative Example 1] An optical laminate C1 with a pressure-sensitive adhesive layer of the test configuration was obtained in the same manner as in Example 1, except that the second release liner was used alone instead of the release liner 1 with a surface protective film and step A-4a was not performed.

[0140] The pressure-sensitive adhesive layer-attached optical laminates 1 to 7 and C1 having the test configurations obtained in the above Examples and Comparative Examples were evaluated as follows. The evaluation results are shown in Table 1 together with the peel force X of the surface protective film from the second release liner for each release liner with surface protective film, and the ratio (X / Y) of the peel force X to the peel force Y of the second release liner from the pressure-sensitive adhesive layer 1. The peel force Y was 0.05 N / 50 mm. <Foreign matter adhesion> The surface of the second release liner of the pressure-sensitive adhesive layer-attached optical laminates 1 to 7 and C1 in the test configuration was observed with an optical microscope at 20x magnification, and the number and size of foreign matter in an area of ​​45mm x 50mm was measured and evaluated according to the following criteria. The results are shown in Table 1. Good: There are less than 10 foreign objects of 50 μm or more in size. × (Fail): There are 10 or more foreign objects with a size of 50 μm or more. <Evaluation of surface protection film lift-off when replacing release liner> The same procedure was carried out a total of 20 times for each of Examples 1 to 7 and Comparative Example 1, and the number of times that lifting occurred between the second release liner and the surface protective film when the first release liner was peeled off from the first intermediate film and the release liner with the surface protective film attached was laminated to the release surface was counted and evaluated according to the following criteria. The results are shown in Table 1. Good: No lifting occurred in all 20 attempts △ (Acceptable): Floating occurred in some of the 20 attempts × (bad): Floating occurred in all 20 tests <Evaluation of peeling of secondary release liner when peeling surface protection film> The same procedure was carried out a total of 20 times for each of Examples 1 to 7 and Comparative Example 1, and the number of times the second release liner was also peeled off when the surface protection film was peeled off from the fourth intermediate film was counted and evaluated according to the following criteria. The results are shown in Table 1. Good: Only the surface protection film was peeled off in all 20 attempts △ (Acceptable): In some of the 20 tests, the second release liner peeled off along with the surface protective film. × (bad): The second release liner peeled off together with the surface protective film in all 20 tests

[0141] [Table 1]

[0142] As shown in Table 1, during the preparation of an optical laminate with an adhesive layer of the inspection configuration, the first release liner protecting the adhesive layer is replaced with a release liner with a surface protective film, and only the surface protective film is peeled off and removed, thereby preventing foreign matter from adhering to the second release liner and, as a result, preventing the false detection of defects during inspection.

[0143] Furthermore, it can be seen that by adjusting the peel force X of the surface protective film to the second release liner and the ratio of this peel force X to the peel force Y of the second release liner to the adhesive layer, it is possible to effectively prevent the problem of the surface protective film lifting when the first release liner is replaced with a release liner with a surface protective film attached, and the problem of the second release liner peeling when the surface protective film is peeled off.

[0144] 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]

[0145] The method for producing a pressure-sensitive adhesive layer-attached optical laminate according to an embodiment of the present invention can be used, for example, to produce goggles with a display, such as VR goggles. [Explanation of symbols]

[0146] 2 display system, 10 polarizing element, 12 display element, 14 reflective polarizing element, 16 first lens portion, 18 half mirror, 20 first phase difference element, 22 second phase difference element, 24 second lens portion, 100 optical laminate, 110 pressure-sensitive adhesive layer, 200 pressure-sensitive adhesive layer-attached optical laminate, 310 first release liner, 320 second release liner, 330 surface protective film, 350 release liner with surface protective film, 410 first intermediate film, 420 second intermediate film, 430 third intermediate film, 440 fourth intermediate film, 450 pressure-sensitive adhesive layer-attached optical laminate of inspection configuration, 460 fifth intermediate film, 470 sixth intermediate film

Claims

1. A method for producing a pressure-sensitive adhesive layer-attached optical laminate having an optical laminate and a pressure-sensitive adhesive layer disposed on one surface of the optical laminate, comprising: Step A of obtaining the pressure-sensitive adhesive layer-attached optical laminate in which a second release liner is disposed on the surface of the pressure-sensitive adhesive layer; and Step B: inspecting the pressure-sensitive adhesive layer-attached optical laminate in a state where the second release liner is placed on the surface of the pressure-sensitive adhesive layer; Including, The manufacturing method, wherein step A comprises replacing the first release liner arranged on the surface of the pressure-sensitive adhesive layer with a release liner with a surface protective film having the second release liner and a surface protective film arranged on one side of the second release liner, and then peeling off the surface protective film.

2. The step A A step A-1a of preparing a first intermediate film having the pressure-sensitive adhesive layer and the first release liner disposed on the surface of the pressure-sensitive adhesive layer; A step A-2a of peeling the first release liner from the first intermediate film and laminating the release liner with the surface protective film to the exposed pressure-sensitive adhesive layer to obtain a second intermediate film; A step A-3a of laminating a third intermediate film on the side of the second intermediate film opposite to the side on which the release liner with the surface protective film is disposed to obtain a fourth intermediate film; and A step A-4a of peeling the surface protective film from the fourth intermediate film; The method of claim 1 , comprising:

3. the first intermediate film further comprises a polarizing member, The method of claim 2 wherein the third intermediate film comprises a first λ / 4 element.

4. preparing a laminate of the first release liner and the pressure-sensitive adhesive layer; and The method according to claim 3 , wherein the first intermediate film is produced by a method including bonding the laminate to the polarizing member with the pressure-sensitive adhesive layer.

5. The method according to claim 1 , wherein the peel force of the surface protection film from the second release liner (at a peel angle of 180° and a peel rate of 300 mm / min) is 0.005 N / 50 mm or more and 0.095 N / 50 mm or less.

6. 2. The manufacturing method according to claim 1, wherein a peel force X of the surface protective film to the second release liner (peel angle 180°, peel speed 300 mm / min) and a peel force Y of the second release liner to the pressure-sensitive adhesive layer (peel angle 180°, peel speed 300 mm / min) satisfy the relationship 0.2<X / Y<1.

7. The method of claim 1 , wherein the second release liner has a total light transmittance of 80% or more.

8. The method of claim 1 , wherein the first release liner has a total light transmittance of 95% or less.

9. The method according to claim 1 , wherein the surface protection film has a total light transmittance of 95% or less.

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