Optical laminate with surface protective film and method for producing same

Abstract

To provide an optical laminate to be applied to a VR goggle, the optical laminate capable of simultaneously realizing a surface protection and a detailed examination of a defect.SOLUTION: An optical laminate having a surface protective film includes: an optical laminate including at least one optical member and to be used for a goggle having a display; and a first surface protective film and a second surface protective film laminated outward in this order on one face of the optical laminate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an optical laminate with a surface protective film and a method for producing the same. [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 panel is enlarged for viewing by the viewer, so the optical laminates used in VR goggles require stricter defect control than the optical laminates 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] As described above, optical laminates used in VR goggles require strict defect control, and therefore undergo precise defect inspection capable of detecting even minute defects. Meanwhile, it is preferable that the surface of the optical laminate be protected until the final assembly process. Therefore, a primary object of the present invention is to provide an optical laminate used in VR goggles that can achieve both surface protection and precise defect inspection. [Means for solving the problem]

[0006] According to one aspect of the present invention, there are provided an optical laminate with a surface protective film [1] to [9], a method for manufacturing an optical laminate with a surface protective film

[10] , and a method for manufacturing a display system

[11] . [1] An optical laminate with a surface protective film, comprising an optical laminate including at least one optical element and used in goggles with a display, and a first surface protective film and a second surface protective film attached in this order outward to one surface of the optical laminate. [2] The optical laminate with a surface protective film according to [1], wherein the haze of the first surface protective film is less than 5%. [3] An optical laminate with a surface protective film described in [1] or [2], obtained by adhering a surface protective film to the optical laminate, the surface protective film having a first substrate and a first adhesive layer laminated on the first substrate, wherein the absolute value of the maximum valley depth (Sv) of the surface of the first adhesive layer opposite the first substrate is 500 nm or less, and when the first substrate is observed under a microscope, the number of defects with a maximum Feret's diameter of 10 μm or more in an observation area of ​​100 μm x 100 μm is less than three. [4] The optical laminate with a surface protective film according to [3], wherein the absolute value of the arithmetic mean height (Sa) of the surface of the first pressure-sensitive adhesive layer opposite to the first substrate is 25 nm or less. [5] The optical laminate with a surface protective film according to [1] or [2], obtained by attaching, to the optical laminate, a surface protective film having, as the first surface protective film, a first substrate and a first pressure-sensitive adhesive layer laminated on the first substrate, wherein the surface of the first pressure-sensitive adhesive layer opposite to the first substrate satisfies the following formula (1):

number

[10] A method for producing an optical laminate with a surface protective film, the method comprising: attaching a first surface protective film and a second surface protective film to one surface of an optical laminate having at least one optical member, the first surface protective film being selected from (i) and (ii); (i) a first substrate and a first pressure-sensitive adhesive layer laminated on the first substrate; the absolute value of the maximum valley depth (Sv) of the surface of the first pressure-sensitive adhesive layer opposite to the first substrate is 500 nm or less; a surface protection film in which, when the first substrate is observed under a microscope, the number of defects having a maximum Feret's diameter of 10 μm or more is less than three in an observation area of ​​100 μm × 100 μm; (ii) a first substrate and a first pressure-sensitive adhesive layer laminated on the first substrate; a surface protection film on the surface of the first pressure-sensitive adhesive layer opposite to the first substrate, the surface protection film satisfying the following formula (1):

number

[11] A method for manufacturing a display system, comprising: attaching another member to the side of the optical laminate with a surface protective film according to any one of [1] to [9] opposite to the side to which the first surface protective film and the second surface protective film are attached, to obtain a secondary laminate with a surface protective film; peeling off the second surface protective film from the secondary laminate with the surface protective film; inspecting the secondary laminate with the surface protective film for defects; and peeling off the first surface protective film from the secondary laminate with the surface protective film to obtain a secondary laminate; in this order, The method of manufacturing wherein the display system is goggles with a display. [Effects of the Invention]

[0007] The optical laminate with surface protective films according to the embodiment of the present invention has a configuration in which two surface protective films are attached to the surface of the optical laminate. Therefore, even if the outer surface protective film is peeled off and removed before defect inspection, the optical laminate can be inspected for defects while the surface is protected by the inner surface protective film, and scratches and the like can be prevented until just before the assembly process. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view of an optical laminate with a surface protective film according to one embodiment of the present invention. [Figure 2] FIG. 1 is a schematic cross-sectional view illustrating a surface protective film that can be used in an optical laminate with a surface protective film according to an embodiment of the present invention. [Figure 3] 1 is a schematic diagram showing a general configuration of a display system according to an embodiment of the present invention. [Figure 4] 4 is a schematic cross-sectional view showing an example of an optical laminate that can be used in the display system shown in FIG. 3. FIG. [Figure 5] 4 is a schematic cross-sectional view showing an example of an optical laminate that can be used in the display system shown in FIG. 3. FIG. [Figure 6A] 1A-1C are schematic diagrams illustrating a method for manufacturing a display system according to one embodiment of the present invention. [Figure 6B] This is a continuation of Figure 6A. [Figure 6C] This is a continuation of Figure 6B. [Figure 6D] This is a continuation of Figure 6C. [Figure 6E] This is a continuation of Figure 6D. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. In addition, in order to clarify the description, the drawings may show the width, thickness, shape, etc. of each part more schematically than in the embodiment, but these are merely examples and do not limit the interpretation of the present invention.

[0010] (Definition of terms and symbols) The definitions of terms and symbols used in this specification are as follows. (1) Refractive index (nx, ny, nz) "nx" is the refractive index in the direction in which the in-plane refractive index is 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° clockwise or counterclockwise. Furthermore, in this specification, "substantially parallel" includes angles within a range of 0°±10°, such as 0°±5°, preferably 0°±3°, and more preferably 0°±1°. "Substantially perpendicular" includes angles within a range of 90°±10°, such as 90°±5°, preferably 90°±3°, and more preferably 90°±1°.

[0011] A. Optical laminate with surface protection film FIG. 1 is a schematic cross-sectional view of an optical laminate with a surface protective film according to one embodiment of the present invention. The optical laminate with a surface protective film 200 includes an optical laminate 100 that includes at least one optical member and is used in goggles with a display, and a first surface protective film 110 and a second surface protective film 120 that are adhered outward in this order to one surface of the optical laminate 100. The optical laminate 100 may have a pressure-sensitive adhesive layer on the side opposite to the side to which the first surface protective film 110 and the second surface protective film 120 are adhered. In this case, the pressure-sensitive adhesive layer may be protected by a release liner. The first surface protective film 110, the second surface protective film 120, and the release liner are processing components that are temporarily attached (temporarily attached) to the optical laminate 100 and are peeled off and removed when the optical laminate 100 is used.

[0012] The optical laminate with a surface protective film can be produced by attaching a first surface protective film and a second surface protective film to one side of the optical laminate. The first surface protective film and the second surface protective film may be attached to one side of the optical laminate in this order, or a laminate of the first surface protective film and the second surface protective film may be laminated on the optical laminate.

[0013] A-1. First surface protection film 1 and 2, the first surface protective film 110 has a first base material 112 and a first pressure-sensitive adhesive layer 114 laminated on the first base material 112. A release liner 116 is attached (temporarily attached) to the first pressure-sensitive adhesive layer 114 to protect the first pressure-sensitive adhesive layer 114 until the first surface protective film 110 is put into use.

[0014] The haze of the first surface protective film is, for example, 5% or less, preferably 4% or less, more preferably 3% or less, even more preferably 2% or less, and even more preferably 1.5% or less, and typically 0.05% or more. If the haze of the first surface protective film is within the above range, precise defect inspection can be performed even when the surface of the optical laminate is protected by the first surface protective film. A surface protective film having a haze within the above range can be obtained, for example, by using a low-haze substrate and / or pressure-sensitive adhesive layer.

[0015] The 90° trigger peel force (P1) of the first surface protective film against the optical laminate is, for example, 0.05 N to 0.25 N, preferably 0.08 N to 0.2 N, and more preferably 0.10 N to 0.15 N. The 180° trigger peel force (P1') of the first surface protective film against the optical laminate is, for example, 0.05 N to 0.25 N, preferably 0.08 N to 0.2 N, and more preferably 0.10 N to 0.15 N. Generally, when a film is peeled from an edge at a constant peeling speed, the peel force of the film increases with the peel length immediately after peeling begins, reaches a peak, then decreases, and stabilizes at a constant value after a predetermined time has passed. In this specification, the trigger peel force refers to the peak value (maximum value) of the peel force immediately after peeling begins, and the normal peel force refers to the stabilized peel force after a predetermined time has passed since peeling began.

[0016] The ratio (P2 / P1) of the 90° trigger peel strength (P1) of the first surface protective film from the optical laminate to the 90° trigger peel strength (P2) of the second surface protective film from the first surface protective film (the surface of the first surface protective film facing the first substrate) is, for example, 0.1 to 2.0, preferably 0.3 to 1.5, more preferably 0.5 to 1.0, and even more preferably 0.5 to 0.9. The ratio (P2' / P1') of the 180° trigger peel strength (P1') of the first surface protective film from the optical laminate to the 180° trigger peel strength (P2') of the second surface protective film from the first surface protective film (the surface of the first surface protective film facing the first substrate) is, for example, 0.1 to 1.5, preferably 0.3 to 1.2, more preferably 0.5 to 1.0, and even more preferably 0.5 to 0.9.

[0017] The normal peel force of the first surface protective film from the optical laminate (peel angle 180°, tensile speed 300 mm / min) is, for example, 0.01 N / 25 mm to 0.2 N / 25 mm, preferably 0.02 N / 25 mm to 0.12 N / 25 mm, and more preferably 0.03 N / 25 mm to 0.08 N / 25 mm.

[0018] The ratio (P2'' / P1'') of the normal peel strength (P1'') of the first surface protective film from the optical laminate to the normal peel strength (P2'') of the second surface protective film from the first surface protective film (the surface of the first surface protective film facing the first substrate) is, for example, 0.1 to 3.0, preferably 0.5 to 2.5, and more preferably 1.0 to 2.0.

[0019] In one embodiment, when the first surface protective film (with the release liner peeled off) is observed under a microscope, the number of defects with a maximum Feret's diameter of 10 μm or more in an observation area of ​​100 μm × 100 μm is preferably less than 3, more preferably 1 or less, and even more preferably 0. When the number of defects with a diameter of 10 μm or more under a microscope is equal to or less than the above upper limit, false detections caused by the surface protective film in foreign matter inspection can be more stably reduced.

[0020] In one embodiment, when the first surface protective film (with the release liner peeled off) is observed under a microscope, the number of defects with a maximum Feret's diameter of less than 10 μm in an observation area of ​​100 μm × 100 μm is, for example, 10 or less, preferably 5 or less, even more preferably 3 or less, and even more preferably 1 or less. Even if defects are observed during microscope observation of the surface protective film, as long as the maximum Feret's diameter is less than 10 μm and the number is equal to or less than the above upper limit, it is possible to prevent the defects from being erroneously detected during foreign matter inspection.

[0021] <First base material> When the first substrate 114 is observed under a microscope, the number of defects with a maximum Feret's diameter of 10 μm or more in an observation area of ​​100 μm × 100 μm is preferably less than three, more preferably one or less, and even more preferably zero. If the number of defects in the substrate is equal to or less than the above upper limit, false detections caused by the surface protection film in foreign matter inspection can be reduced. Details of the microscope observation will be described in the examples below.

[0022] The tear strength of the first substrate is, for example, 0.5 N / mm or more, preferably 1 N / mm or more, and more preferably 2 N / mm or more. If the tear strength of the first substrate is equal to or greater than the above lower limit, false detections caused by the surface protection film in foreign matter inspection can be further reduced. The tear strength of the first substrate is typically 200 N / mm or less. The tear strength of the first substrate can be measured in accordance with JIS K7128-1:1998.

[0023] The first substrate is formed of any suitable resin film that can be used as a surface protection film. Specific examples of materials that can be the main component of the resin film include cycloolefin (COP) resins such as polynorbornene, polyesters such as polyethylene terephthalate (PET), cellulose resins such as triacetyl cellulose (TAC), and transparent resins such as polycarbonate (PC), (meth)acrylic, polyvinyl alcohol, polyamide, polyimide, polyethersulfone, polysulfone, polystyrene, polyolefin, and acetate. Examples of suitable resins include thermosetting or ultraviolet-curable resins such as (meth)acrylic, urethane, (meth)acrylic urethane, epoxy, and silicone. The term "(meth)acrylic resin" refers to acrylic resins and / or methacrylic resins. Other examples include glassy polymers such as siloxane polymers. The 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.

[0024] The first substrate preferably contains at least one transparent resin selected from the group consisting of COP, PET, TAC, PC, and (meth)acrylic resins, more preferably at least one transparent resin selected from the group consisting of COP, PET, PC, and (meth)acrylic resins, and even more preferably at least one transparent resin selected from the group consisting of COP, PET, and PC. When the first substrate contains the transparent resin, false detections due to the surface protective film in foreign body inspection and air bubble inspection can be more stably reduced. Furthermore, when the first substrate contains one of the COP, PET, PC, and (meth)acrylic transparent resins, false detections due to the surface protective film in foreign body inspection can be reduced compared to when the first substrate contains a TAC resin. In particular, when the first substrate contains one of the COP, PET, and PC transparent resins, false detections due to the surface protective film in foreign body inspection can be more stably reduced.

[0025] The first substrate may contain an antioxidant, an ultraviolet absorber, a light stabilizer, a nucleating agent, a filler, a pigment, a surfactant, an antistatic agent, etc. The surface of the first substrate (the surface opposite to the first pressure-sensitive adhesive layer) may be provided with an easy-adhesion layer, an easy-slip layer, an antiblocking layer, an antistatic layer, an antireflection layer, an oligomer prevention layer, etc.

[0026] The thickness of the first substrate is typically 5 μm or more, preferably 20 μm or more, and typically 200 μm or less, preferably 100 μm or less.

[0027] <First adhesive layer> The absolute value of the maximum valley depth (Sv) of the surface 114a of the first pressure-sensitive adhesive layer 114 opposite the first substrate 112 before being attached to the optical laminate is, for example, 500 nm or less, preferably 300 nm or less, more preferably 250 nm or less, particularly preferably 200 nm or less, particularly preferably 100 nm or less, and most preferably 50 nm or less. The absolute value of the maximum valley depth (Sv) of the surface 114a is typically 5 nm or more. The maximum valley depth (Sv) can be measured in accordance with JIS B0681-2:2018. When the absolute value of the maximum valley depth (Sv) of the surface 114a of the first pressure-sensitive adhesive layer 114 before being attached to the optical laminate is equal to or less than the above upper limit, false detections due to the surface protection film can be reduced even when the surface protection film is subjected to defect inspection (e.g., air bubble inspection) while attached to the optical laminate.

[0028] The absolute value of the arithmetic mean height (Sa) of the surface 114a of the first pressure-sensitive adhesive layer 114 opposite the first substrate 112 before being attached to the optical laminate is preferably 25 nm or less, more preferably 10 nm or less, even more preferably 6 nm or less, and particularly preferably 5 nm or less. The absolute value of the arithmetic mean height (Sa) of the surface 114a is typically 0 nm or more. The arithmetic mean height (Sa) can be measured in accordance with JIS B0681-2:2018. If the absolute value of the arithmetic mean height (Sa) of the surface 114a of the first pressure-sensitive adhesive layer 114 before being attached to the optical laminate is equal to or less than the above upper limit, false detections due to the surface protective film in defect inspections (e.g., air bubble inspections) can be stably reduced.

[0029] The surface 114a of the first adhesive layer 114 opposite the first substrate 112 before being attached to the optical laminate preferably satisfies the following formula (1), more preferably satisfies the following formula (2), and even more preferably satisfies the following formula (3).

number

number

number

[0030] In the two-dimensional image before binarization, among the recessed portions present on the surface of the first pressure-sensitive adhesive layer opposite the first substrate, portions corresponding to recesses having a depth exceeding the detection limit of the white light interferometer are black regions, and portions not corresponding to the black regions are white regions. The area B-BA of the black regions in the two-dimensional image before binarization is, when the measurement field of view area S of the white light interferometer is taken as 100%, for example, 1.5% or less, preferably 0.3% or less, more preferably 0.2% or less, even more preferably 0.1% or less, and typically 0% or more.

[0031] In the two-dimensional image after binarization (hereinafter sometimes referred to as a binarized image), the area that is -100 nm or less from the measurement surface becomes a white area, and the other area (area that exceeds -100 nm from the measurement surface) becomes a black area. When the measurement field area S of the white light interferometer is taken as 100%, the area A-WA of the white area in the binarized image is, for example, 1.3% or less, preferably 0.2% or less, more preferably 0.1% or less, even more preferably 0.08% or less, and typically 0% or more.

[0032] If the surface of the first adhesive layer opposite the first substrate before being attached to the optical laminate has a shape that satisfies the above formula (1), preferably formula (2), and more preferably formula (3), even if the surface protection film is subjected to defect inspection (e.g., air bubble inspection) while attached to the optical laminate, false detections caused by the surface protection film can be suitably reduced.

[0033] The first pressure-sensitive adhesive layer typically contains at least one pressure-sensitive adhesive selected from the group consisting of (meth)acrylic pressure-sensitive adhesives, urethane pressure-sensitive adhesives, and silicone pressure-sensitive adhesives. Preferably, the first pressure-sensitive adhesive layer contains a (meth)acrylic pressure-sensitive adhesive.

[0034] The (meth)acrylic pressure-sensitive adhesive contains a polymer (hereinafter referred to as a (meth)acrylic polymer) of a monomer component whose main component is alkyl(meth)acrylate. In other words, 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 mass or more, preferably 80% by mass or more, more preferably 93% by mass or more, and for example 100% by mass or less, preferably 98% by mass or less.

[0035] 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 butyl group, a 2-ethylhexyl group, a decyl group, an isodecyl group, and an octadecyl group. The alkyl (meth)acrylates can be used alone or in combination. The average number of carbon atoms in the alkyl group is preferably 3 to 10.

[0036] 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 and a hydroxyl group-containing monomer. The copolymerizable monomers can be used alone or in combination.

[0037] 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 is preferably 0.01% by mass or more and 10% by mass or less.

[0038] The hydroxyl group-containing monomer is a compound containing a hydroxyl group and a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group in its structure. 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 mass or more and 10% by mass or less.

[0039] The weight average molecular weight Mw of the (meth)acrylic polymer is, for example, 100,000 to 2,000,000, and preferably 200,000 to 1,000,000.

[0040] The (meth)acrylic pressure-sensitive 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 pressure-sensitive adhesive contains a crosslinking agent, the content of the crosslinking agent is typically 0.01 to 15 parts by mass per 100 parts by mass of the (meth)acrylic polymer.

[0041] The above-mentioned pressure-sensitive adhesives ((meth)acrylic pressure-sensitive adhesives, urethane pressure-sensitive adhesives, and silicone pressure-sensitive adhesives) may contain various additives in appropriate proportions as necessary. By adjusting the composition of the base polymer (e.g., the type and content of the monomer, the type and content of the cross-linking agent), the molecular weight of the base polymer, the type or content of the additive, etc., a pressure-sensitive adhesive layer having the desired adhesiveness to the adherend can be obtained.

[0042] Examples of additives include polymerization initiators, solvents, polymerization catalysts, crosslinking catalysts, silane coupling agents, tackifiers, plasticizers, softeners, antidegradants, fillers, colorants (pigments, dyes, etc.), ultraviolet absorbers, antioxidants, surfactants, antistatic agents, and chain transfer agents.

[0043] The thickness of the first pressure-sensitive adhesive layer is typically 1 μm or more, preferably 5 μm or more, more preferably 10 μm or more, and typically 30 μm or less, preferably 20 μm or less.

[0044] The first PSA layer may be formed on the surface of the first substrate by direct printing or by transfer printing. In the case of direct printing, the PSA is directly applied to the surface of the first substrate to form the first PSA layer. In the case of transfer printing, the PSA is applied to the surface of a release liner to form the first PSA layer, and then the substrate is attached to the first PSA layer. In particular, when the first substrate contains an amorphous resin with a relatively low glass transition temperature Tg (e.g., 150°C or lower), the first PSA layer is preferably formed by a transfer process. The transfer process can prevent the high temperature during drying required to form the first PSA layer from affecting the first substrate.

[0045] <Release liner> The release liner 116 is formed of any suitable resin film that can be used as a release liner. Specific examples of materials that are the main components of the resin film include polyethylene terephthalate (PET), polyethylene, and polypropylene. The resin film materials can be used alone or in combination. The release liner 116 may or may not be transparent.

[0046] A release treatment layer may be provided on the surface of the release liner 116 that comes into contact with the surface 114a of the first pressure-sensitive adhesive layer 114. 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, preferably silicone-based release treatment agents, and more preferably vinyl group-containing addition silicones. 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.

[0047] The contact surface of the release liner 116 with the surface 114a of the first PSA layer 114 is smooth. Specifically, the absolute value of the maximum peak height (Sp) at the contact surface of the release liner 116 with the first PSA layer 114 is typically 500 nm or less, preferably 400 nm or less, more preferably 300 nm or less, and even more preferably 100 nm or less. When the absolute value of the maximum peak height (Sp) at the contact surface is the above-mentioned upper limit or less, the maximum valley depth (Sv) of the surface of the first PSA layer opposite the first substrate can be stably adjusted to be the above-mentioned upper limit or less. Furthermore, when the absolute value of the maximum peak height (Sp) at the contact surface is the above-mentioned upper limit or less, the surface of the first PSA layer opposite the first substrate can be stably adjusted to satisfy the above-mentioned formula (1). The absolute value of the maximum peak height (Sp) at the contact surface is typically 10 nm or more. The maximum peak height (Sp) can be measured in accordance with JIS B0681-2:2018.

[0048] The absolute value of the arithmetic mean height (Sa) of the contact surface of release liner 116 with surface 114a of first PSA layer 114 is typically 30 nm or less, preferably 20 nm or less, more preferably 10 nm or less, and even more preferably 5 nm or less. The absolute value of the arithmetic mean height (Sa) of the contact surface is typically 0 nm or more.

[0049] The thickness of the release liner 116 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 treatment layer is applied, the thickness of the release liner includes the thickness of the release treatment layer.

[0050] A-2. Secondary surface protection film 1, the second surface protective film 120 has a second substrate 122 and a second pressure-sensitive adhesive layer 124 laminated on the second substrate. As with the first surface protective film, a release liner is attached (temporarily attached) to the second pressure-sensitive adhesive layer to protect the second pressure-sensitive adhesive layer until the second surface protective film is put into use.

[0051] The second surface protection film may be transparent (for example, haze ≦5%) or opaque.

[0052] The 90° trigger peel force of the second surface protective film from the first surface protective film (the surface of the first surface protective film facing the first substrate) is, for example, 0.01 N to 0.20 N, preferably 0.03 N to 0.15 N, and more preferably 0.05 N to 0.12 N. The 180° trigger peel force of the second surface protective film from the first surface protective film (the surface of the first surface protective film facing the first substrate) is, for example, 0.01 N to 0.20 N, preferably 0.03 N to 0.15 N, and more preferably 0.05 N to 0.12 N.

[0053] The typical peel force (peel angle 180°, tensile speed 300 mm / min) of the second surface protection film from the first surface protection film (surface of the first surface protection film facing the first substrate) is, for example, 0.01 N / 25 mm to 0.2 N / 25 mm, preferably 0.03 N / 25 mm to 0.15 N / 25 mm, and more preferably 0.05 N / 25 mm to 0.1 N / 25 mm.

[0054] <Second base material> The second substrate is formed of any suitable resin film that can be used as a surface protection film. Specific examples of the material that is the main component of the resin film are as described above for the first substrate.

[0055] The second substrate may contain an antioxidant, an ultraviolet absorber, a light stabilizer, a nucleating agent, a filler, a pigment, a surfactant, an antistatic agent, etc. The surface of the second substrate (the surface opposite to the second pressure-sensitive adhesive layer) may be provided with an easy-adhesion layer, an easy-slip layer, an antiblocking layer, an antistatic layer, an antireflection layer, an oligomer prevention layer, etc.

[0056] The thickness of the second substrate is typically 5 μm or more, preferably 20 μm or more, and typically 200 μm or less, preferably 100 μm or less.

[0057] <Second adhesive layer> The second pressure-sensitive adhesive layer typically contains at least one pressure-sensitive adhesive selected from the group consisting of (meth)acrylic pressure-sensitive adhesives, urethane pressure-sensitive adhesives, and silicone pressure-sensitive adhesives. Preferably, the second pressure-sensitive adhesive layer contains a (meth)acrylic pressure-sensitive adhesive. Details of the (meth)acrylic pressure-sensitive adhesive are as described above for the first pressure-sensitive adhesive layer.

[0058] The above-mentioned pressure-sensitive adhesives ((meth)acrylic pressure-sensitive adhesives, urethane pressure-sensitive adhesives, and silicone pressure-sensitive adhesives) may contain a base polymer (or its constituent monomer components) and, if necessary, additives. Specific examples of the additives are as described above for the first pressure-sensitive adhesive layer.

[0059] The thickness of the second pressure-sensitive adhesive layer is typically 1 μm or more, preferably 5 μm or more, and typically 30 μm or less, preferably 15 μm or less.

[0060] The second pressure-sensitive adhesive layer may be formed by the same method as the first pressure-sensitive adhesive layer.

[0061] A-3. Optical laminate The optical laminate includes at least one optical member, and is used in goggles with a display. Examples of the optical member include a polarizing member (an absorptive polarizing member or a reflective polarizing member) and a phase difference member.

[0062] A-3-1. Display system to which the optical laminate can be applied FIG. 3 is a schematic diagram showing the general configuration of a display system (goggles with a display) to which the optical laminate can be applied. FIG. 3 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 element 14, a first lens unit 16, a half mirror 18, a first phase difference element 20, a second phase difference element 22, and a second lens unit 24. The reflective polarizing element 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 element 14, and the half mirror 18 is disposed between the display element 12 and the first lens unit 16. The first phase difference element 20 is disposed on the optical path between the display element 12 and the half mirror 18, and the second phase difference element 22 is disposed on the optical path between the half mirror 18 and the reflective polarizing element 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 .

[0063] The components arranged in front of the half mirror (in the illustrated example, the half mirror 18, the first lens section 16, the second phase difference member 22, the reflective polarizing member 14, and the second lens section 24) may be collectively referred to as the lens section (lens section 4).

[0064] 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 a polarizing member (typically, a polarizing film) 10 that may be included in the display element 12, and is converted into first linearly polarized light.

[0065] 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. The first phase difference member 20 may be provided integrally with the display element 12.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] The light transmitted through the reflective polarizing member 14 passes through the second lens portion 24 and enters the eye 26 of the user.

[0071] For example, the absorption axis of the polarizing member 10 included in the display element 12 and the reflection axis of the reflective polarizing member 14 may be disposed approximately parallel to each other or approximately perpendicular to each other. The angle formed between the absorption axis of the polarizing member 10 included in the display element 12 and the slow axis of the first λ / 4 member included in the first retardation member 20 is, for example, 40° to 50°, or may be 42° to 48°, or may be approximately 45°. The angle formed between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the second λ / 4 member included in the second retardation member 22 is, for example, 40° to 50°, or may be 42° to 48°, or may be approximately 45°.

[0072] In the lens unit 4, a space may be formed between the first lens unit 16 and the second lens unit 24. In this case, the member disposed between the first lens unit 16 and the second lens unit 24 is preferably provided integrally with either the first lens unit 16 or the second lens unit 24. For example, the member disposed between the first lens unit 16 and the second lens unit 24 is preferably integrated with either the first lens unit 16 or the second lens unit 24 via an adhesive layer. This configuration can improve the ease of handling of each member, for example. The adhesive layer may be formed of an adhesive or a pressure-sensitive adhesive. Specifically, the adhesive layer may be an adhesive layer or a pressure-sensitive adhesive layer. The thickness of the adhesive layer is, for example, 0.05 μm to 30 μm.

[0073] A-3-2. Configuration of optical laminate FIG. 4 is a schematic cross-sectional view of an optical laminate that can be used in the display system illustrated in FIG. 3. The optical laminate 100a includes, in this order, a pressure-sensitive adhesive layer 31, a polarizing member 10, a first retardation member 20, and a first protective member 41. The polarizing member 10, the first retardation member 20, and the first protective member 41 are laminated via adhesive layers 51 and 52. The adhesive layers 51 and 52 are typically adhesive layers or pressure-sensitive adhesive layers, and are preferably pressure-sensitive adhesive layers. The thickness of the adhesive layer is, for example, 0.05 μm to 30 μm. The surface of the pressure-sensitive adhesive layer 31 is protected by a release liner 61 until use. The first surface protective film and the second surface protective film are attached to the surface of the optical laminate 100a facing the first protective member 41.

[0074] In the example shown in FIG. 4, the first phase difference member 20 includes, in addition to the first λ / 4 member 20a, a member (so-called positive C plate) 20b whose refractive index characteristics can exhibit the relationship nz>nx=ny. The first phase difference member 20 has a laminated structure of the first λ / 4 member 20a and the first positive C plate 20b. As shown in the example, the first λ / 4 member 20a is preferably located closer to the polarizing member 10 than the first positive C plate 20b, but their locations may be reversed. The first positive C plate 20b may also be omitted. The first λ / 4 member 20a and the first positive C plate 20b are laminated, for example, via an adhesive layer (not shown). In the first phase difference member 20, the angle between the absorption axis of the polarizing member 10 and the slow axis of the first λ / 4 member 20a is preferably 40° to 50°, more preferably 42° to 48°, e.g., approximately 45°.

[0075] The optical laminate 100a can be used to manufacture a display system according to an embodiment shown in FIG. 3, in which the first retardation member 20 is integrally provided with the display element 12. For example, a display system in which the first retardation member 20 is integrally provided with the liquid crystal panel (display element) can be manufactured by peeling the release liner 61 from the optical laminate 100a and bonding the polarizing member 10 to a liquid crystal cell together with a rear-side polarizing member so that the polarizing member 10 serves as the front-side (viewing side) polarizing member of the liquid crystal cell. Alternatively, a display system in which the first retardation member 20 is integrally provided with the organic EL panel (display element) can be manufactured by peeling the release liner 61 from the optical laminate 100a and bonding the optical laminate 100a to the front of the organic EL panel via the adhesive layer 31. In this case, a third retardation member including a third λ / 4 member can be disposed between the optical laminate 100a and the organic EL panel to prevent reflection. The third retardation member may be included in the optical laminate. For example, the optical laminate may have a pressure-sensitive adhesive layer, a third retardation member, a polarizing member, a first retardation member, and a protective member in this order. The same explanation as for the first λ / 4 member can be applied to the third λ / 4 member. The third retardation member can be arranged so that the slow axis of the third λ / 4 member forms an angle of, for example, 40° to 50°, 42° to 48°, or approximately 45° with the absorption axis of the polarizing member 10.

[0076] <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.

[0077] The crossed transmittance (Tc) of the absorptive polarizing element (absorptive polarizing film) is preferably 0.5% or less, more preferably 0.1% or less, and even more preferably 0.05% or less. The single transmittance (Ts) of the absorptive polarizing element (absorptive polarizing film) is, for example, 41.0% to 45.0%, and preferably 42.0% or more. The polarization degree (P) of the absorptive polarizing element (absorptive polarizing film) is, for example, 99.0% to 99.997%, and preferably 99.9% or more.

[0078] 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

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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 through treatment steps, such as dyeing and underwater stretching, in which the laminate is immersed in a liquid. 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.

[0084] 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.

[0085] 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.

[0086] <The 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.

[0087] The first λ / 4 member preferably exhibits a refractive index characteristic in the relation 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] <First positive C-plate> The thickness direction retardation Rth(550) of the first 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 first positive C plate is, for example, less than 10 nm.

[0099] The first positive C plate can be formed of any appropriate material. The first 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 the retardation layer described in

[0020] to

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

[0100] <First protective member> The first protective member 41 typically includes a substrate. The substrate may 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, 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.

[0101] The first protective member preferably has a substrate and a surface treatment layer formed on the substrate. The first 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 100a. 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 first protective member may have two or more surface treatment layers. The water contact angle of the surface of the surface treatment layer can be, for example, 90° or more and 125° or less, or, for example, 100° or more and 115° or less.

[0102] 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), or 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 first protective member, and a first surface protective film is attached to the surface of the antireflection layer. According to an embodiment in which the antireflection layer is provided on the outermost surface of the first 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.

[0103] 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.

[0104] <Adhesive layer> The adhesive layer 31 may be composed of any appropriate adhesive. 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 the monomers forming the base resin of the adhesive, as well as the amount of crosslinking agent, reaction temperature, reaction time, etc., it is possible to prepare an adhesive having desired properties according to the purpose. The base resin of the adhesive may be used alone or in combination of two or more types. An acrylic resin is preferably used as the base resin. Specifically, the adhesive layer is preferably composed of an acrylic adhesive.

[0105] The thickness of the pressure-sensitive adhesive layer is typically 1 μm or more, preferably 5 μm or more, more preferably 12 μm or more, and typically 60 μm or less, preferably 30 μm or less, more preferably 23 μm or less.

[0106] <Release liner> The release liner 61 is formed of any appropriate resin film. Specific examples of materials that are the main components of the resin film include polyethylene terephthalate (PET), polyethylene, and polypropylene. The resin film materials can be used alone or in combination. The release liner may be transparent (e.g., with a haze of 5% or less, e.g., 3% or less), or may not be transparent.

[0107] A release treatment layer may be provided on the surface of the release liner 61 that comes into contact with the pressure-sensitive adhesive layer 31. 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.

[0108] The thickness of the release liner is typically 5 μm or more, preferably 20 μm or more, and typically 60 μm or less, preferably 45 μm or less. When a release treatment layer is applied, the thickness of the release liner includes the thickness of the release treatment layer.

[0109] FIG. 5 is a schematic cross-sectional view of another optical laminate that can be used in the display system illustrated in FIG. 3. The optical laminate 100b includes, in this order, a pressure-sensitive adhesive layer 32, a second retardation member 22, and a second protective member 42. The second retardation member 22 and the second protective member 42 are laminated via an adhesive layer 53. The adhesive layer 53 is typically an adhesive layer or a pressure-sensitive adhesive layer, and is preferably a pressure-sensitive adhesive layer. The thickness of the adhesive layer is, for example, 0.05 μm to 30 μm. The surface of the pressure-sensitive adhesive layer 32 is protected by a release liner 62 until use. The first surface protective film and the second surface protective film are attached to the second protective member 42 side of the optical laminate 100b.

[0110] In the example shown in FIG. 5, the second phase difference member 22 includes, in addition to the second λ / 4 member 22a, a member (so-called positive C plate) 22b whose refractive index characteristics can satisfy the relationship nz>nx=ny. The second phase difference member 22 has a laminated structure of the second λ / 4 member 22a and the second positive C plate 22b. As shown in the example, the second λ / 4 member 22a is preferably located closer to the second protective member 42 than the second positive C plate 22b, but this arrangement may be reversed. Furthermore, the second positive C plate 22b may be omitted. The second λ / 4 member 22a and the second positive C plate 22b are laminated together, for example, via an adhesive layer (not shown).

[0111] The optical laminate 100b can be applied to the manufacture of a display system in an embodiment where the second retardation member 22 is integrally provided on the first lens unit 16, for example, in the display system illustrated in FIG. 3. Specifically, by peeling off the release liner 62 from the optical laminate 100b and bonding it to the first lens unit 16 via the adhesive layer 32, a display system in which the second retardation member 22 is integrally provided on the first lens unit 16 can be manufactured.

[0112] <Second λ / 4 member> The in-plane retardation Re(550) of the second λ / 4 member 22a 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 retardation value increases according to the wavelength of the measurement light. 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.

[0113] The second 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 second 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.

[0114] The second λ / 4 member is formed of any suitable material that can satisfy the above characteristics. The second λ / 4 member can be, for example, a stretched film of a resin film or an alignment cured layer of a liquid crystal compound. For the second λ / 4 member composed of a stretched film of a resin film or an alignment cured layer of a liquid crystal compound, the same description as that of the first λ / 4 member can be applied. The first λ / 4 member and the second λ / 4 member may have the same configuration (for example, forming material, thickness, optical characteristics, etc.) or different configurations.

[0115] <Second positive C-plate> The thickness direction retardation Rth(550) of the second positive C plate 22b 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 second positive C plate is, for example, less than 10 nm.

[0116] The second positive C plate is formed of any appropriate material that can satisfy the above characteristics. The same explanation as for the first positive C plate can be applied to the constituent material of the second positive C plate. The first positive C plate and the second positive C plate may have the same configuration (e.g., forming material, thickness, optical properties, etc.) or different configurations.

[0117] <Second protective member> The second protective member 42 typically includes a substrate, and preferably has a substrate and a surface treatment layer formed on the substrate. In this case, the surface treatment layer may be located on the outermost surface of the optical laminate 100b. Details of the substrate and the surface treatment layer can be similar to those of the first protective member. According to an embodiment in which an anti-reflection layer is provided on the outermost surface of the second protective member 42 as the surface treatment layer, an excellent anti-reflection effect can be obtained in a display system in which the second retardation member 22 is integrated with the first lens unit 16, the reflective polarizing member 14 is integrated with the second lens unit 24, and a space is formed between them.

[0118] The same explanations as for the pressure-sensitive adhesive layer 31 and release liner 61 used in the optical laminate 100a can be applied to the pressure-sensitive adhesive layer 32 and release liner 62 used in the optical laminate 100b.

[0119] B. Display System Manufacturing Method According to another aspect of the present invention, there is provided a method for manufacturing a display system (goggles with a display) using the optical laminate with a surface protective film described in Section A. The method for manufacturing a display system according to an embodiment of the present invention includes peeling the second surface protective film from the optical laminate with a surface protective film described in Section A to obtain an optical laminate with only the first surface protective film attached, and inspecting an object for defects in which the optical laminate with only the first surface protective film attached is bonded to another member. The second surface protective film may be peeled off before or after the object is produced (i.e., the optical laminate with a surface protective film is bonded to another member). A method for manufacturing a display system according to one embodiment of the present invention includes: Attaching another member to the side of the optical laminate with a surface protective film described in item A opposite to the side to which the first surface protective film and the second surface protective film are attached, thereby obtaining a secondary laminate with a surface protective film; peeling off the second surface protective film from the secondary laminate with the surface protective film; inspecting the secondary laminate with the surface protective film for defects; and peeling off the first surface protective film from the secondary laminate with the surface protective film to obtain a secondary laminate; Contains, in this order: The resulting secondary laminate is subjected to an assembly process and assembled with other components to form a display system. An example of a method for manufacturing the display system of the present invention will now be described with reference to FIG.

[0120] The optical laminate 200 with a surface protective film shown in FIG. 6A has the optical laminate 100a illustrated in FIG. 4, with a first surface protective film 110 and a second surface protective film 120 adhered outward in this order to the surface of the first protective material 41 of the optical laminate 100a. In one embodiment, the optical laminate 100a is processed into a shape corresponding to the shape of the object to be adhered (another member 300 shown in FIG. 6(b)). For example, the optical laminate 200 with a surface protective film is processed into the desired shape by cutting, punching, machining, etc. As shown in Figure 6B, the release liner 61 is peeled off from the optical laminate 200 with the surface protective film, and the exposed adhesive layer 31 is attached to the viewing side (front) surface of an optical component (e.g., a liquid crystal cell, an organic EL panel) 300 to obtain a secondary laminate 400a with the surface protective film. Next, as shown in FIG. 6C, the second surface protective film 120 is peeled off from the secondary laminate with the surface protective film 400a to obtain a secondary laminate with the surface protective film 400b. Next, as shown in FIG. 6D, a defect inspection is carried out on the secondary laminate 400b with the surface protective film, the surface of which is protected by the first surface protective film 110. 6E, the first surface protective film 110 is peeled off from the secondary laminate 400b with the surface protective film that has been determined to be a non-defective product in the defect inspection, to obtain a secondary laminate 400c, which is then used to assemble a display system.

[0121] According to the above manufacturing method, it is possible to preferably prevent scratches, foreign matter, dirt, etc. from adhering to the surface of the optical laminate until immediately before incorporation into the display system, and it is also possible to perform precise defect inspection on the optical member immediately before incorporation into the display system. Such an effect is particularly advantageous when processes such as manufacturing the optical laminate, manufacturing the display element, and assembling the display system are carried out in different locations. In one embodiment, the optical laminate is shipped to a display element manufacturer as a first semi-finished product in the form of an optical laminate with surface protection films attached to two surface protection films (e.g., Figure 6A); by attaching the optical laminate with surface protection films to an optical component such as a liquid crystal cell or an organic EL element, a display element (liquid crystal panel, organic EL panel, etc.) with the optical laminate with surface protection films attached is obtained (e.g., Figure 6B); from this, the second surface protection film is peeled off, and the display element is inspected for defects while its surface is protected by the first surface protection film (e.g., Figures 6C and D); a display element that is determined to be good in the defect inspection is shipped to a display system manufacturer as a second semi-finished product with the first surface protection film attached; after peeling off the first surface protection film, the display element can be assembled with other components (e.g., Figure 6E). According to the manufacturing method of this embodiment, it is possible to effectively prevent defects (scratches, foreign matter, dirt, etc.) when shipping the first semi-finished product, to inspect for defects when manufacturing the second semi-finished product, and to effectively prevent defects (scratches, foreign matter, dirt, etc.) when shipping the second semi-finished product, which can ultimately contribute to the efficient manufacturing of final products.

[0122] The manufacturing method of the display system is not limited to the illustrated example. For example, the second surface protective film may be peeled off before the release liner is peeled off and the optical element is attached, and the defect inspection may be performed before the optical element is attached. For example, the second surface protective film and the release liner may be peeled off, and the optical laminate with only the first surface protective film attached may be inspected for defects, and then the optical laminate may be attached to the optical element. Also, for example, the second surface protective film may be peeled off, and the optical laminate with the first surface protective film and the release liner attached may be inspected for defects, and then the release liner may be peeled off, and the optical laminate may be attached to the optical element.

[0123] The defect inspection can be performed by automated optical inspection (AOI), visual inspection, etc. Preferably, the defect inspection includes automated optical inspection (AOI). The defect inspection may be performed using a transmission optical system, a reflection optical system, or a combination of these, depending on the purpose. [Example]

[0124] 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"). <Haze of surface protection film> For each surface protection film, the release liner was peeled off from the adhesive layer, and the haze was measured in accordance with JIS K7136 using a haze meter ("NDH-5000" manufactured by Nippon Denshoku Industries Co., Ltd.) by irradiating light from the substrate side of the surface protection film.

[0125] [Production Example 1A: Preparation of Surface Protection Film A] <Acrylic polymer A> 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 A (concentration 40% by weight). The weight-average molecular weight of acrylic polymer A was 540,000.

[0126] <Adhesive composition A> Ethyl acetate was added to the solution of acrylic polymer A to dilute it to a concentration of 20% by mass. To 500 parts by mass of this solution (solid content 100 parts by mass), 4 parts by mass of an isocyanurate of hexamethylene diisocyanate ("Coronate HX" manufactured by Tosoh Corporation) as a crosslinking agent and 3 parts by mass (solid content 0.03 parts by mass) of dibutyltin dilaurate (1% by mass ethyl acetate solution) as a crosslinking catalyst were added and stirred to prepare PSA composition A.

[0127] <Surface protection film A> PSA composition A was applied to one side of a substrate (PET film, "CE905-38" manufactured by KOLON Co., Ltd., thickness 38 μm) and then dried to form a PSA layer (thickness 15 μm). Next, a release liner (manufactured by Toyobo Co., Ltd., product number TG704) was attached to the surface of the PSA layer opposite the substrate. This gave surface protection film A. The haze of surface protection film A was 1.8%.

[0128] [Production Example 1B: Preparation of Surface Protection Film B] A pressure-sensitive adhesive layer (thickness 15 μm) was formed in the same manner as in Production Example 1A, except that a PET film ("CE901-38" manufactured by KOLON Co., Ltd., thickness 38 μm) was used as the substrate. Next, a release liner (manufactured by Toyobo Co., Ltd., product number TG704) was attached to the surface of the pressure-sensitive adhesive layer opposite the substrate. This resulted in surface protection film B. The haze of surface protection film B was 3.9%.

[0129] [Production Example 1C: Preparation of Surface Protection Film C] A surface protection film C was obtained in the same manner as in Production Example 1A, except that a PET film (product number T100C38, manufactured by Mitsubishi Chemical Corporation, thickness 38 μm) was used as the substrate and PSA composition A was applied to its corona-treated surface to form a PSA layer with a thickness of 5 μm. The haze of surface protection film C was 2.6%.

[0130] The above surface protection film B and the release liner used in the production thereof were evaluated in the following items (1) to (5). (1) Surface shape evaluation test of adhesive layer In the surface protection film, the release liner was peeled off from the pressure-sensitive adhesive layer to expose the surface of the pressure-sensitive adhesive layer opposite to the substrate. Next, the surface protection film from which the release liner had been removed was set in a white light interferometer (manufactured by Zygo, trade name Zygo NewView7300) so that the exposed surface of the adhesive layer faced the objective lens, and the interference data of the adhesive layer surface was measured under the following conditions. White light interferometer measurement conditions: Objective lens: ×10 Internal lens: ×1.0 Resolution; 1.09μm Measurement field of view area (S); 0.3641mm 2 Removed;Cylinder The obtained interference data was subjected to frequency domain analysis (calculation software: MetroPro) within an analysis range (depth direction) of -1000 nm to -2000 nm relative to the measurement surface (reference surface), and a two-dimensional image was obtained in which the corresponding areas were shown as black regions. The measurement plane (reference plane) was set based on the plane with the average height within the measurement field of view. The area of ​​the black region in the two-dimensional image (B-BA) is shown in Table 2. The two-dimensional image was then subjected to binarization analysis with a threshold of -100 nm relative to the measurement surface, resulting in a binarized image in which the area below -100 nm was a white region. The area of ​​the white region in the binarized image (A-WA) is shown in Table 2. Next, the ratio of the total area of ​​the black region in the two-dimensional image (B-BA) and the total area of ​​the white region in the binarized image (A-WA) to the measurement field area S of the white light interferometer was calculated (see formulas (1) to (3) above). The results are shown in Table 2.

[0131] (2) Measurement of maximum valley depth and arithmetic mean height on the surface of the adhesive layer In the two-dimensional image obtained from the measurement using the white light interferometer described above, the minimum value relative to the average surface within the measurement field of view was taken as the maximum valley depth (Sv). The Ra value was taken as the arithmetic mean height (Sa). The maximum valley depth and arithmetic mean height were calculated by averaging the data from three randomly selected points. The results are shown in Table 2.

[0132] (3) Measurement of the maximum peak height and arithmetic mean height of the release liner In (1) above, the release liner peeled from the adhesive layer was set in the white light interferometer, and the interference data of the release liner was measured under the conditions described above to obtain a two-dimensional image. The maximum value relative to the average surface within the measurement field of view in the obtained two-dimensional image was taken as the maximum peak height (Sp). The Ra value was taken as the arithmetic mean height (Sa). The maximum peak height and arithmetic mean height were calculated by averaging the data from three randomly selected points. The results are shown in Table 1.

[0133] (4) Measuring the number of defects on the substrate by microscopic observation The surface of the substrate was observed using a microscope (OLYMPUS Corporation, product name BX51, eyepiece magnification 10x, objective lens magnification 10x). Next, a 0.1 mm x 0.1 mm area was randomly selected from the observation field, and the number of defects with a maximum Feret's diameter of 10 μm or more was visually counted. The results are shown in Table 1.

[0134] (5) Measurement of the tear strength of the substrate Measurements were basically carried out in accordance with JIS K7128-1:1998. Specifically, the substrate was cut into a size of 150 mm x 50 mm. Next, a 75 mm slit was made parallel to the long side from the center of the end of the short side to prepare a sample piece. For the MD tear strength, the long side was parallel to the MD, and for the TD tear strength, the long side was parallel to the TD. The obtained test specimen was attached to a tensile tester and evaluated at a pulling rate of 200 mm / min (in an atmosphere of 23°C and 50% relative humidity) to measure the tear strength. The tear strength f was calculated from the obtained tear force. (f = Ft / d (Ft: tear strength of test specimen [N], d: thickness of test specimen [mm])) The results are shown in Table 1.

[0135] [Table 1]

[0136] [Table 2]

[0137] [Peeling force evaluation: initial peeling force] For surface protection films A and B, the 90° and 180° trigger peel strengths were measured against the surface of the surface treatment layer side of the protective member produced in Production Example 5 described below. Furthermore, for surface protection film C, the 90° and 180° trigger peel strengths were measured against the surface of surface protection film A or B facing the substrate side. Measurements were performed with N=10, and the average value was taken as the trigger peel strength. The results are shown in Table 3. The trigger peel strength was measured as follows: <Method for measuring initial peel strength> (1) Surface protection films A and B The protective member was cut into a rectangular film piece (50 mm x 50 mm) and attached to a SUS plate via double-sided adhesive tape (Nitto Denko Corporation, "No. 535A"). The acrylic film was attached to the SUS plate. Next, surface protection film A or B, cut to the same shape, was laminated onto the surface of the surface treatment layer of the protective member using a hand roller, with one stroke back and forth. This resulted in a laminate having a [SUS plate / protective member / surface protection film] configuration. A piece of adhesive tape (Nitto Denko Corporation, "No. 315", 25 mm wide) cut to a length of approximately 10 cm was placed 2 cm from the corner of the surface protection film of the laminate, and the tape was then laminated using a 2 kg roller, with one stroke back and forth. A measurement sample was obtained. For the above measurement samples, the peel force when peeling the surface protection film from a corner of the measurement sample was measured under the following conditions, and the peak value immediately after the start of measurement was taken as the initial peel force of surface protection film A or B. Measurement equipment: Tensile testing machine (Kyowa Interface Science Co., Ltd., adhesive coating peeling analysis device "VPA-2"; turn on the power and allow to age for at least 30 minutes.) Measurement environment: 23±5°C, 60±20% RH Peeling speed: 300mm / min Peel angle: 90° or 180° (2) Surface protection film C Surface protection film A or B was cut into a rectangular film piece (50 mm x 50 mm), the release liner was peeled off, and the piece was bonded to a SUS plate via the exposed adhesive layer. Surface protection film C was then bonded to the surface of the base layer of the surface protection film, and the initial peel force of protection film C was measured in the same manner as above (1), except that [Table 3]

[0138] [Peeling force evaluation: normal peeling force] For surface protection films A and B, the normal peel strength was measured against the surface of the surface treatment layer side of the protective member of the optical laminate produced in Example 1 described below. Furthermore, for surface protection film C, the normal peel strength was measured against the surface of surface protection film A or B facing the substrate side. N=30 measurements were performed, and the average value was taken as the normal peel strength. The results are shown in Table 4. The normal peel strength was measured as follows: <Normal peel strength measurement method> The surface protection film was cut into a size of 25 mm wide and 100 mm long, the release liner was peeled off from the adhesive layer, and the sample was roll-bonded to the adherend at a pressure of 0.25 MPa and a feed rate of 0.3 m / min. This sample was then left to stand in an environment at a temperature of 23°C and a relative humidity of 50% for 30 minutes, after which a peel test was conducted in the same environment at a peel angle of 180° and a pulling rate of 300 mm / min, and the 180° peel strength was measured. [Table 4]

[0139] [Production Example 2: Preparation of polarizing film] 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 aqueous solution used for the washing treatment had a potassium iodide content of 2.6% by weight. Finally, the film was dried at 70°C for 5 minutes to obtain an absorptive polarizing film. A hydroxylated triacetylcellulose (TAC) resin film (TAC thickness: 25 μm, HC 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, the 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 having a structure of [TAC film (protective layer) / absorptive polarizing film / COP film (protective layer)] was obtained.

[0140] [Manufacturing Example 3: Fabrication of λ / 4 components] Polymerization was carried out using a batch polymerization apparatus consisting of two vertical reactors equipped with stirring blades and reflux condensers controlled at 100° C. The polymerization mixture contained 29.60 parts by mass (0.046 mol) of bis[9-(2-phenoxycarbonylethyl)fluoren-9-yl]methane, 29.21 parts by mass (0.200 mol) of isosorbide (ISB), 42.28 parts by mass (0.139 mol) of spiroglycol (SPG), 63.77 parts by mass (0.298 mol) of diphenyl carbonate (DPC), and 1.19 × 10 calcium acetate monohydrate as a catalyst. -2 Part of mass (6.78×10 -5 (mol) was charged. After purging the reactor with nitrogen under reduced pressure, heating was performed using a heat transfer medium. Stirring was initiated when the internal temperature reached 100°C. Forty minutes after the start of the temperature increase, the internal temperature reached 220°C. This temperature was maintained while simultaneously reducing the pressure. 90 minutes after reaching 220°C, the pressure was reduced to 13.3 kPa. Phenol vapor by-produced during the polymerization reaction was introduced into a reflux condenser at 100°C, and the small amount of monomer components contained in the phenol vapor was returned to the reactor. Uncondensed phenol vapor was collected by introducing nitrogen into the first reactor and temporarily restoring the pressure to atmospheric pressure. The oligomerized reaction liquid in the first reactor was then transferred to the second reactor. Next, heating and depressurization of the second reactor were initiated, and the internal temperature reached 240°C and the pressure reached 0.2 kPa in 50 minutes. The polymerization was then allowed to proceed until the specified stirring power was reached. When the predetermined power was reached, nitrogen was introduced into the reactor to restore pressure, and the polyester carbonate resin produced was extruded into water, and the strands were cut to obtain pellets.

[0141] 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 to obtain a 47µm thick stretched film (λ / 4 member). The resulting stretched film had an Re(550) of 143nm, an Re(450) / Re(550) of 0.86, and an Nz coefficient of 1.12.

[0142] [Manufacturing Example 4: Preparation of positive C-plate] 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 with a thickness of 4 μm and an Rth(550) of -100 nm on the substrate. [ka]

[0143] [Manufacturing Example 5: Preparation of protective member] The hard coat layer-forming material shown below was applied to an acrylic film (thickness: 40 μm) having a lactone ring structure, and the applied layer was dried to form a hard coat layer with a thickness of 0.5 μm. Next, the antireflection layer-forming material shown below was applied to the surface of the hard coat layer and heated at 80°C for 1 minute. After heating, the applied layer was irradiated with a high-pressure mercury lamp at an integrated light intensity of 300 mJ / cm. 2 The coating layer was cured by irradiation with ultraviolet light of 1000 kJ / cm 2 to form an antireflection layer having a thickness of 0.1 μm, thereby obtaining a protective member having a structure of [acrylic film / hard coat layer / antireflection layer].

[0144] (Hard Coat Layer Forming Material) A hard coat layer-forming material was prepared by adding 0.5 wt% of a leveling agent to an acrylic resin raw material (manufactured by Dai Nippon Ink Co., Ltd., product name: GRANDIC PC1071) and further diluting with ethyl acetate to a solids concentration of 50 wt%. The leveling agent was a copolymer copolymerized in a molar ratio of dimethylsiloxane:hydroxypropylsiloxane:6-isocyanatehexylisocyanuric acid:aliphatic polyester = 6.3:1.0:2.2:1.0.

[0145] (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.

[0146] [Production Example 6: Preparation of adhesive layer] 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 (solid content). Nitrogen gas was introduced and purged with nitrogen while gently stirring. The liquid temperature in the flask was then maintained at approximately 55°C for 8 hours to prepare an acrylic polymer solution. The weight-average molecular weight of the acrylic polymer was 1.5 million. 0.3 parts benzoyl peroxide (BPO: Niper BMT, manufactured by NOF Corporation) as a crosslinking agent was blended with 100 parts of the resulting acrylic polymer solution (solid content) to prepare an acrylic adhesive solution. The obtained adhesive composition was applied to the release-treated layer surface of a release liner (Cerapeel, manufactured by Toray Industries, Inc.) and dried at 155°C for 3 minutes to form an adhesive layer with a thickness of 20µm.

[0147] [Example 1] (1) A surface protective film laminate was obtained using surface protective film A as the first surface protective film and surface protective film C as the second surface protective film. Specifically, the release liner was peeled from surface protective film C and attached to the substrate surface of surface protective film A to obtain a surface protective film laminate having a configuration of [release liner / surface protective film A / surface protective film C]. (2) The pressure-sensitive adhesive layer obtained in Production Example 6 was attached to the COP protective layer side surface of the polarizing film obtained in Production Example 2 together with a release liner to obtain a polarizing film with a pressure-sensitive adhesive layer. (3) The positive C-plate was transferred to a λ / 4 member (stretched film) via a UV-curable adhesive (thickness 1 μm after curing) to obtain a retardation member. The protective member obtained in Production Example 5 was attached to the positive C-plate side of the obtained retardation member via another acrylic pressure-sensitive adhesive layer. At this time, the acrylic film of the protective member was attached to the retardation member side (in other words, the antireflection layer was attached to the outermost surface). Next, another acrylic pressure-sensitive adhesive layer formed on a release liner was attached to the surface of the λ / 4 member. This resulted in a laminate having a configuration of [protective member / positive C-plate / λ / 4 member / acrylic pressure-sensitive adhesive layer / release liner]. (4) The surface protection film laminate obtained in (1) was bonded to the protective member side surface of the laminate obtained in (3) via the adhesive layer exposed by peeling off the release liner on the surface protection film A side. Immediately after bonding, rectangular Film A was punched out by cutting with a blade from above. Note that rectangular Film A was punched with a blade die such that the slow axis of the λ / 4 component was parallel to the short direction. Similarly, rectangular Film B was punched out by cutting with a blade from above the polarizing film with adhesive layer obtained in (2). Note that rectangular Film B was punched with a blade die such that the absorption axis of the absorptive polarizing film was at a 45° angle to the longitudinal direction. The release liner of Film A was peeled off, and Film A was bonded to Film B with its longitudinal direction aligned without tension. As described above, Film A was punched so that the slow axis of the λ / 4 component was parallel to the short direction, and Film B was punched so that the absorption axis of the absorptive polarizing film was at a 45° angle. Therefore, the angle between the absorption axis of the absorptive polarizing film and the slow axis of the λ / 4 component was 45°. In this way, an optical laminate with a surface protective film having a structure of [optical laminate (release liner / adhesive layer / polarizing member / λ / 4 member / positive C plate / protective member) / surface protective film A / surface protective film C] was obtained.

[0148] [Example 2] An optical laminate with a surface protective film having a structure of [optical laminate / surface protective film B / surface protective film C] was obtained in the same manner as in Example 1, except that the above-mentioned surface protective film B was used as the first surface protective film.

[0149] [Comparative Example 1] An optical laminate with a surface protective film having a configuration of [optical laminate / surface protective film C] was obtained in the same manner as in Example 1, except that only surface protective film C was attached to the protective member side surface (anti-reflection layer surface) of the laminate obtained in (3) of Example 1 above.

[0150] Comparative Example 2 An optical laminate with a surface protective film having a configuration of [optical laminate / surface protective film A] was obtained in the same manner as in Example 1, except that only surface protective film A was attached to the protective member side surface (anti-reflection layer surface) of the laminate obtained in (3) of Example 1 above.

[0151] Comparative Example 3 An optical laminate with a surface protective film having a configuration of [optical laminate / surface protective film B] was obtained in the same manner as in Example 1, except that only surface protective film B was attached to the protective member side surface (anti-reflection layer surface) of the laminate obtained in (3) of Example 1 above.

[0152] [Defect inspection] The optical laminates with surface protective films obtained in the above Examples and Comparative Examples were cut to a size of 371.87 mm × 236.58 mm and used as test samples. The test samples of Examples 1 and 2 were subjected to defect inspection with the release liner and second surface protective film removed, while the test samples of Comparative Examples 1 to 3 were subjected to defect inspection with the release liner removed. Specifically, the test samples were set in the chucking section of an optical automatic appearance inspection device, and defects of 100 μm or larger (scratches, foreign matter, air bubbles, etc.) were detected. Next, the areas where defects of 100 μm or larger were detected were observed under a microscope to determine whether they were false detections of defects caused by the surface protective film or defects in the optical laminate. The test failure rate was calculated based on the formula: "Test failure rate (%) = number of false detections / total number of detections × 100," and the effectiveness of the test was evaluated based on the following criteria. Furthermore, the presence or absence of scratches of 100 μm or larger on the surface of the surface protective film was confirmed, and scratch evaluation was performed based on the following criteria. The results are shown in Table 5. <Evaluation of the effectiveness of testing> Good: Inspection failure rate: 0% △ (Acceptable): Inspection failure rate: Over 0% and less than 10% × (defective): Inspection defect rate 10% or more <Scratch evaluation> Good: No scratches of 100 μm or more × (Fail): Scratches of 100 μm or more

[0153] [Table 5]

[0154] As shown in Table 5, the optical laminate with surface protective film of the example, which has a configuration in which two surface protective films are attached to the surface of the optical laminate, is protected from scratches by the outer surface protective film before defect inspection. Furthermore, even if the outer surface protective film is peeled off and removed during defect inspection, the optical laminate can be inspected for defects with the inner surface protective film still attached, and its surface can be suitably protected until it is used for assembly. Furthermore, by using an inner surface protective film with low haze, automatic inspection of the optical laminate can be suitably performed with the surface protective film still attached.

[0155] 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]

[0156] The protective film-attached optical laminate according to an embodiment of the present invention can be used, for example, in the manufacture of goggles with a display, such as VR goggles. [Explanation of symbols]

[0157] 2 Display System 4 Lens section 10 Polarizing element 12 Display element 14 Reflective polarizing element 16 First lens part 18 Half Mirror 20 First phase difference member 22 Second phase difference member 24 Second lens section 100 Optical laminate 110 First Surface Protection Film 120 Second Surface Protection Film 200 Optical laminate with surface protection film

Claims

1. An optical laminate including at least one optical element and used in goggles with a display; a first surface protective film and a second surface protective film attached in this order outward to one surface of the optical laminate; An optical laminate with a surface protective film, The first surface protective film may include: A first substrate and a first pressure-sensitive adhesive layer laminated on the first substrate, an optical laminate with a surface protective film, obtained by attaching a surface protective film satisfying the following formula (1) to the surface of the first pressure-sensitive adhesive layer opposite to the first substrate, to the optical laminate; [Equation 1] (In formula (1), S represents the measurement field area of ​​the white light interferometer in the surface shape evaluation test described below; B-BA represents the area of ​​the black region in the two-dimensional image before binarization obtained in the surface shape evaluation test described below; and A-WA represents the area of ​​the white region in the two-dimensional image after binarization obtained in the surface shape evaluation test described below.) <Surface shape evaluation test> measuring the surface of the first pressure-sensitive adhesive layer opposite to the first substrate using a white light interferometer; The obtained interference data is subjected to frequency domain analysis within an analysis range of −1000 nm to −2000 nm relative to the measurement surface to obtain a two-dimensional image in which the corresponding areas become black regions; The two-dimensional image is subjected to binarization analysis with a threshold value of −100 nm relative to the measurement surface, to obtain a binarized image in which the area below −100 nm becomes a white area.

2. The optical laminate with a surface protective film according to claim 1 , wherein the first surface protective film has a haze of less than 5%.

3. 2. An optical laminate with a surface protective film as described in claim 1, wherein when the first substrate is observed under a microscope, the number of defects with a maximum Feret diameter of 10 μm or more is less than three in an observation area of ​​100 μm x 100 μm.

4. The optical laminate with a surface protective film according to claim 1 , wherein the optical laminate has a polarizing member, a first phase difference member, and a protective member in this order toward the first surface protective film.

5. the protective member includes a surface treatment layer, The optical laminate with a surface protective film according to claim 4 , wherein the first surface protective film is attached to the surface treatment layer.

6. The optical laminate with a surface protective film according to claim 1, wherein the optical laminate has an adhesive layer on the side opposite to the side to which the first surface protective film and the second surface protective film are attached.

7. A method for producing an optical laminate with a surface protective film, comprising: a first surface protective film and a second surface protective film attached to one surface of an optical laminate having at least one optical member; a production method in which the first surface protective film has a first substrate and a first pressure-sensitive adhesive layer laminated on the first substrate, and a surface of the first pressure-sensitive adhesive layer opposite to the first substrate satisfies the following formula (1): [Equation 2] (In formula (1), S represents the measurement field area of ​​the white light interferometer in the surface shape evaluation test described below; B-BA represents the area of ​​the black region in the two-dimensional image before binarization obtained in the surface shape evaluation test described below; and A-WA represents the area of ​​the white region in the two-dimensional image after binarization obtained in the surface shape evaluation test described below.) <Surface shape evaluation test> measuring the surface of the first pressure-sensitive adhesive layer opposite to the first substrate using a white light interferometer; The obtained interference data is subjected to frequency domain analysis within an analysis range of −1000 nm to −2000 nm relative to the measurement surface to obtain a two-dimensional image in which the corresponding areas become black regions; The two-dimensional image is subjected to binarization analysis with a threshold value of −100 nm relative to the measurement surface, to obtain a binarized image in which the area below −100 nm becomes a white area.

8. 1. A method for manufacturing a display system, comprising:

7. A secondary laminate with a surface protective film is obtained by attaching another member to the side of the optical laminate with a surface protective film according to claim 1 opposite to the side to which the first surface protective film and the second surface protective film are attached. peeling off the second surface protective film from the secondary laminate with the surface protective film; inspecting the secondary laminate with the surface protective film for defects; and peeling off the first surface protective film from the secondary laminate with the surface protective film to obtain a secondary laminate; in this order, The method of manufacturing wherein the display system is goggles with a display.

Images