WO2023176589A1

WO2023176589A1 - Optical laminate equipped with surface protection film, and production method therefor

Info

Publication number: WO2023176589A1
Application number: PCT/JP2023/008560
Authority: WO
Inventors: 健太郎小野; 祥明麻野井; 周作後藤
Original assignee: 日東電工株式会社
Priority date: 2022-03-14
Filing date: 2023-03-07
Publication date: 2023-09-21
Also published as: TW202402524A

Abstract

The main purpose of the present invention is to provide an optical laminate that is applied to VR goggles, and that can satisfy both of surface protection and minute defect inspection. The present invention provides an optical laminate equipped with a surface protection film, comprising: an optical laminate which includes at least one optical member and is for use in display-equipped goggles; and a first surface protection film and a second surface protection film that are stuck on one surface of the optical laminate in the stated order toward the outer side.

Description

Optical laminate with surface protection film and manufacturing method thereof

The present invention relates to an optical laminate with a surface protection film and a method for manufacturing the same.

Image display devices represented by liquid crystal display devices and electroluminescence (EL) display devices (eg, organic EL display devices) are rapidly becoming popular. In image display devices, optical members such as polarizing members and retardation members are generally used to realize image display and improve image display performance (see, for example, Patent Document 1).

In recent years, new uses for image display devices have been developed. For example, goggles with a display (VR goggles) for realizing Virtual Reality (VR) are beginning to be commercialized. In VR goggles, the image displayed on the display panel is enlarged for the viewer to see, so the optical laminate used in VR goggles is more expensive than the optical laminate used in conventional image display devices. Strict defect management is also required.

JP2021-103286A

As mentioned above, strict defect management is required for optical laminates applied to VR goggles, so a precise defect inspection that can detect even the smallest defects is performed. On the other hand, the surface of the optical laminate is preferably protected until the final assembly process. Therefore, the main object of the present invention is to provide an optical laminate that can be applied to VR goggles and is capable of both surface protection and precise defect inspection.

According to one aspect of the present invention, the optical laminate with a surface protection film of [1] to [9], the method of manufacturing an optical laminate with a surface protection film of [10], and the production of a display system of [11] A method is provided.
[1] An optical laminate that includes at least one optical member and is used for goggles with a display, and a first surface protection film that is adhered to one surface of the optical laminate in this order outward. and a second surface protection film, an optical laminate with a surface protection film.
[2] The optical laminate with a surface protection film according to [1], wherein the first surface protection film has a haze of less than 5%.
[3] The first surface protection film has a first base material and a first adhesive layer laminated on the first base material, and the first base material in the first adhesive layer A defect in which the absolute value of the maximum valley depth (Sv) on the opposite surface is 500 nm or less, and the maximum Feret diameter is 10 μm or more in an observation area of 100 μm x 100 μm when the first base material is observed with a microscope. The optical laminate with a surface protection film according to [1] or [2], which is obtained by attaching less than three surface protection films to the optical laminate.
[4] The optical laminate with a surface protection film according to [3], wherein the absolute value of the arithmetic mean height (Sa) of the surface of the first adhesive layer opposite to the first base material is 25 nm or less. .
[5] The first surface protection film has a first base material and a first adhesive layer laminated on the first base material, and the first base material in the first adhesive layer The surface on the opposite side is the optical laminate with a surface protection film according to [1] or [2], which is obtained by attaching a surface protection film satisfying the following formula (1) to the optical laminate. ;

(In formula (1), S represents the measurement field area of the white interferometer in the following surface shape evaluation test; B-BA is the area of the black area in the two-dimensional image before binarization obtained in the following surface shape evaluation test. (A-WA indicates the area of the white region in the two-dimensional image after binarization obtained in the surface shape evaluation test below.)
<Surface shape evaluation test>
measuring the surface of the first adhesive layer opposite to the first base material using a white interferometer;
After calculating the obtained interference data by frequency domain analysis in the analysis range of -1000 nm to -2000 nm with respect to the measurement surface to obtain a two-dimensional image in which the corresponding location becomes a black area;
The two-dimensional image is binarized and analyzed using −100 nm as a threshold value with respect to the measurement surface to obtain a binarized image in which the portion below −100 nm is a white region.
[6] The optical device with a surface protection film according to [5], wherein when the first base material is observed under a microscope, the number of defects with a maximum Feret diameter of 10 μm or more is less than 3 in an observation area of 100 μm x 100 μm. laminate.
[7] The optical laminate includes a polarizing member, a first retardation member, and a protective member in this order toward the first surface protection film, according to any one of [1] to [6]. Optical laminate with surface protection film.
[8] The optical laminate with a surface protection film according to [7], wherein the protection member includes a surface treatment layer, and the first surface protection film is attached to the surface treatment layer.
[9] Any one of [1] to [8], wherein the optical laminate has an adhesive layer on the side opposite to the side to which the first surface protection film and the second surface protection film are attached. An optical laminate with a surface protection film according to claim 1.
[10] A method for producing an optical laminate with a surface protection film, which comprises attaching a first surface protection film and a second surface protection film to one surface of an optical laminate having at least one optical member. A manufacturing method comprising: the first surface protection film selected from (i) and (ii);
(i) having a first base material and a first adhesive layer laminated on the first base material,
The absolute value of the maximum valley depth (Sv) of the surface of the first adhesive layer opposite to the first base material is 500 nm or less,
A surface protection film having less than three defects with a maximum Feret diameter of 10 μm or more in an observation area of 100 μm x 100 μm when the first base material is observed under a microscope;
(ii) having a first base material and a first adhesive layer laminated on the first base material,
The surface of the first adhesive layer opposite to the first base material is a surface protection film that satisfies the following formula (1);

(In formula (1), S represents the measurement field area of the white interferometer in the following surface shape evaluation test; B-BA is the area of the black area in the two-dimensional image before binarization obtained in the following surface shape evaluation test. (A-WA indicates the area of the white region in the two-dimensional image after binarization obtained in the surface shape evaluation test below.)
<Surface shape evaluation test>
measuring the surface of the first adhesive layer opposite to the first base material using a white interferometer;
After calculating the obtained interference data by frequency domain analysis in the analysis range of -1000 nm to -2000 nm with respect to the measurement surface to obtain a two-dimensional image in which the corresponding location becomes a black area;
The two-dimensional image is binarized and analyzed using −100 nm as a threshold value with respect to the measurement surface to obtain a binarized image in which the portion below −100 nm is a white region.
[11] A method for manufacturing a display system, wherein the first surface protection film and the second surface protection film of the optical laminate with a surface protection film according to any one of [1] to [9] are pasted. Obtaining a secondary laminate with a surface protection film by pasting another member on the side opposite to the side on which it was applied;
Peeling the second surface protection film from the surface protection film-attached secondary laminate;
inspecting the secondary laminate with the surface protection film for defects; and peeling the first surface protection film from the secondary laminate with the surface protection film to obtain a secondary laminate;
In this order,
A manufacturing method, wherein the display system is goggles with a display.

The optical laminate with a surface protection film according to the embodiment of the present invention has a configuration in which two surface protection films are attached to the surface of the optical laminate. Therefore, even if the outer surface protection 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 protection film, and scratches etc. can be prevented until just before the assembly process. can be prevented.

1 is a schematic cross-sectional view of an optical laminate with a surface protection film according to one embodiment of the present invention. 1 is a schematic cross-sectional view illustrating a surface protection film that can be used in an optical laminate with a surface protection film according to an embodiment of the present invention. 1 is a schematic diagram showing a general configuration of a display system according to one embodiment of the present invention. 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. 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. 1 is a schematic diagram illustrating a method of manufacturing a display system according to one embodiment of the present invention. FIG. It is a figure following FIG. 6A. It is a figure following FIG. 6B. It is a figure following FIG. 6C. It is a figure following FIG. 6D.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. Further, in order to make the explanation more clear, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the embodiment, but this is just an example, and the interpretation of the present invention is It is not limited.

(Definition of terms and symbols)
Definitions of terms and symbols used herein are as follows.
(1) Refractive index (nx, ny, nz)
"nx" is the refractive index in the direction in which the in-plane refractive index is maximum (i.e., slow axis direction), and "ny" is the direction perpendicular to the slow axis in the plane (i.e., fast axis direction) "nz" is the refractive index in the thickness direction.
(2) In-plane phase difference (Re)
"Re(λ)" is an in-plane retardation measured with light having a wavelength of λnm at 23°C. For example, "Re(550)" is an in-plane retardation measured with light having a wavelength of 550 nm at 23°C. Re(λ) is determined by the formula: Re(λ)=(nx−ny)×d, where d (nm) is the thickness of the layer (film).
(3) Phase difference in thickness direction (Rth)
"Rth (λ)" is a retardation in the thickness direction measured with light having a wavelength of λ nm at 23°C. For example, "Rth (550)" is the retardation in the thickness direction measured with light having a wavelength of 550 nm at 23°C. Rth(λ) is determined 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 determined by Nz=Rth/Re.
(5) Angle When an angle is referred to in this specification, the angle includes both clockwise and counterclockwise directions with respect to the reference direction. Thus, for example, "45°" means 45° clockwise or counterclockwise. In addition, in this specification, "substantially parallel" includes cases within the range of 0°±10°, for example, 0°±5°, preferably 0°±3°, more preferably 0°±1 90°±5°, preferably 90°±3°, more preferably 90°±1 within the range of °.

A. Optical laminate with surface protection film FIG. 1 is a schematic cross-sectional view of an optical laminate with a surface protection film according to one embodiment of the present invention. The optical laminate 200 with a surface protection film includes at least one optical member, and is attached to the optical laminate 100 and one surface of the optical laminate 100 in this order toward the outside, for use in goggles with a display. It has a first surface protection film 110 and a second surface protection film 120. The optical laminate 100 may have an adhesive layer on the surface opposite to the side to which the first surface protection film 110 and the second surface protection film 120 are attached. In this case, the adhesive layer may be protected with a release liner. The first surface protection film 110, the second surface protection film 120, and the release liner are process members that are temporarily attached (temporary attachment) to the optical laminate 100, and are used when the optical laminate 100 is put into use. When it is removed, it is peeled off and removed.

The optical laminate with a surface protection film can be produced by attaching a first surface protection film and a second surface protection film to one surface of the optical laminate. A first surface protection film and a second surface protection film may be attached in this order to one surface of the optical laminate, and a laminate of the first surface protection film and the second surface protection film may be laminated to the optical laminate. You may.

A-1. First surface protection film As shown in FIGS. 1 and 2, the first surface protection film 110 includes a first base material 112 and a first adhesive layer 114 laminated on the first base material 112. have A release liner 116 is attached (temporarily attached) to the first adhesive layer 114 to protect the first adhesive layer 114 until the first surface protection film 110 is put into use. .

The haze of the first surface protection film is, for example, 5% or less, preferably 4% or less, more preferably 3% or less, even more preferably 2% or less, even more preferably 1.5% or less, and typically 0. It is .05% or more. If the haze of the first surface protection 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 protection film. A surface protection film having a haze within the above range can be obtained, for example, by using a low haze base material and/or an adhesive layer.

The 90° triggered peeling force (P1) of the first surface protection film against the optical laminate is, for example, 0.05N to 0.25N, preferably 0.08N to 0.2N, more preferably 0.10N to 0.15N. be. The 180° triggered peeling force (P1') of the first surface protection film against the optical laminate is, for example, 0.05N to 0.25N, preferably 0.08N to 0.2N, more preferably 0.10N to 0.15N. It is. Generally, when peeling a film from the edge at a constant peeling speed, the peeling force of the film increases depending on the peeling length immediately after the start of peeling, reaches a peak, then decreases, and then reaches a certain level after a predetermined period of time. Stabilize at the value. In this specification, triggered peeling force means the peak value (maximum value) of peeling force immediately after the start of peeling, and normal peeling force means the stabilized peeling force after a predetermined period of time has passed from the start of peeling. do.

90° triggered peeling force (P1) of the first surface protection film against the optical laminate and 90° triggered peeling force of the second surface protection film against the first surface protective film (first substrate side surface of the first surface protective film) The ratio (P2/P1) to (P2) is, for example, 0.1 to 2.0, preferably 0.3 to 1.5, more preferably 0.5 to 1.0, even more preferably 0.5 to It is 0.9. In addition, the 180° triggered peeling force (P1') of the first surface protection film against the optical laminate and the 180° trigger peeling force (P1') of the second surface protection film against the first surface protection film (first substrate side surface of the first surface protection film) The ratio (P2'/P1') to the triggered peeling force (P2') is, for example, 0.1 to 1.5, preferably 0.3 to 1.2, more preferably 0.5 to 1.0, and Preferably it is 0.5 to 0.9.

The normal peeling force of the first surface protection film against 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 0.02 N/25 mm. 12N/25mm, more preferably 0.03N/25mm to 0.08N/25mm.

The normal peeling force (P1'') of the first surface protection film against the optical laminate and the normal peeling force (P2'') of the second surface protection film against the first surface protection film (first substrate side surface of the first surface protection film). '') is, for example, 0.1 to 3.0, preferably 0.5 to 2.5, more preferably 1.0 to 2.0.

In one embodiment, when the first surface protection film (with the release liner removed) is observed under a microscope, the number of defects with a maximum Feret diameter of 10 μm or more is preferably 3 in an observation area of 100 μm x 100 μm. It is less than 1, more preferably 1 or less, and even more preferably 0. When the number of defects of 10 μm or more in microscopic observation of the surface protection film is below the above upper limit, false detections caused by the surface protection film can be more stably reduced in foreign matter inspection.

In one embodiment, when the first surface protection film (with the release liner peeled off) is observed under a microscope, the number of defects with a maximum Feret diameter of less than 10 μm in an observation area of 100 μm x 100 μm is, for example, 10 or less. , preferably 5 or less, more preferably 3 or less, more preferably 1 or less. Even if a defect is observed in microscopic observation of the surface protection film, as long as the maximum Feret diameter is less than 10 μm and the number is below the above upper limit, it is possible to suppress the defect from being erroneously detected in a foreign object inspection.

<First base material>
When the first base material 114 is observed under a microscope, the number of defects with a maximum Feret diameter of 10 μm or more in an observation area of 100 μm x 100 μm is preferably less than 3, more preferably 1 or less, and even more preferably 0. It is. If the number of defects in the base material is below the above upper limit, false detections caused by the surface protection film can be reduced in foreign matter inspection. Note that details of the microscopic observation will be explained in Examples described later.

The tear strength of the first base material 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 base material is equal to or higher 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 base material is typically 200 N/mm or less. Note that the tear strength of the first base material can be measured in accordance with JIS K7128-1:1998.

The first base material is formed of any suitable resin film that can be used as a surface protection film. Specific examples of materials that are the main components of the resin film include cycloolefin (COP) systems such as polynorbornene systems, polyester systems such as polyethylene terephthalate (PET) systems, cellulose resins such as triacetyl cellulose (TAC), Examples include transparent resins such as polycarbonate (PC), (meth)acrylic, polyvinyl alcohol, polyamide, polyimide, polyethersulfone, polysulfone, polystyrene, polyolefin, and acetate. Further, thermosetting resins or ultraviolet curable resins such as (meth)acrylic, urethane, (meth)acrylic urethane, epoxy, and silicone resins may also be mentioned. Note that "(meth)acrylic resin" refers to acrylic resin and/or methacrylic resin. Other examples include glassy polymers such as siloxane polymers. Furthermore, the polymer film described in JP-A-2001-343529 (WO01/37007) can also be used. Materials for this film include, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in its side chain, and a thermoplastic resin having a substituted or unsubstituted phenyl group and nitrile group in its side chain. For example, a resin composition containing an alternating copolymer of isobutene and N-methylmaleimide and an acrylonitrile/styrene copolymer can be used. The polymer film may be, for example, an extrusion molded product of the resin composition. The materials for the resin film can be used alone or in combination.

The first base material preferably contains at least one transparent resin selected from the group consisting of COP-based, PET-based, TAC-based, PC-based, and (meth)acrylic-based, and more preferably COP-based, PET-based, etc. The resin contains at least one transparent resin selected from the group consisting of COP-based, PC-based, and (meth)acrylic-based, and more preferably at least one transparent resin selected from the group consisting of COP-based, PET-based, and PC-based. Contains resin. When the first base material contains the above-mentioned transparent resin, false detections caused by the surface protection film can be more stably reduced in foreign object inspection and air bubble inspection. In addition, when the first base material contains any one of COP-based, PET-based, PC-based, and (meth)acrylic-based transparent resins, compared to the case where the first base material contains TAC-based resins, foreign matter inspection Erroneous detections caused by surface protection films can be reduced. In particular, when the first base material contains any one of COP-based, PET-based, and PC-based transparent resins, it is possible to more stably reduce false detections caused by the surface protection film in foreign matter inspection.

The first base material may contain an antioxidant, an ultraviolet absorber, a light stabilizer, a nucleating agent, a filler, a pigment, a surfactant, an antistatic agent, and the like. The surface of the first base material (the surface opposite to the first adhesive layer) is provided with an easy-adhesion layer, an easy-slip layer, an anti-blocking layer, an antistatic layer, an anti-reflection layer, an anti-oligomer layer, etc. Good too.

The thickness of the first base material is typically 5 μm or more, preferably 20 μm or more, and typically 200 μm or less, preferably 100 μm or less.

<First adhesive layer>
The absolute value of the maximum valley depth (Sv) of the surface 114a opposite to the first base material 112 in the first adhesive layer 114 before being attached to the optical laminate is, for example, 500 nm or less, preferably 300 nm. The thickness is 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. Note that 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 adhesive layer 114 before being attached to the optical laminate is below the above upper limit, the state in which the surface protection film is attached to the optical laminate Even when subjected to defect inspection (for example, bubble inspection), false detections caused by the surface protection film can be reduced.

The absolute value of the arithmetic mean height (Sa) of the surface 114a opposite to the first base material 112 in the first adhesive layer 114 before being attached to the optical laminate is preferably 25 nm or less, more preferably 10 nm. The thickness is more preferably 6 nm or less, 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. Note that 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 adhesive layer 114 before being attached to the optical laminate is equal to or less than the above upper limit, the surface protective film will not be used in defect inspection (for example, bubble inspection). It is possible to stably reduce false detections caused by

The surface 114a of the first adhesive layer 114 opposite to the first base material 112 before being attached to the optical laminate preferably satisfies the following formula (1), more preferably satisfies the following formula (2). More preferably, the following formula (3) is satisfied.

(In formula (1), S represents the measurement field area of the white interferometer in the following surface shape evaluation test; B-BA is the area of the black area in the two-dimensional image before binarization obtained in the following surface shape evaluation test. (A-WA indicates the area of the white region in the two-dimensional image after binarization obtained in the surface shape evaluation test below.)
<Surface shape evaluation test>
measuring the surface of the first adhesive layer opposite to the first base material with a white interferometer;
After calculating the obtained interference data by frequency domain analysis in the analysis range of -1000 nm to -2000 nm with respect to the measurement surface to obtain a two-dimensional image in which the corresponding location becomes a black area;
The two-dimensional image is binarized and analyzed using −100 nm as a threshold value with respect to the measurement surface to obtain a binarized image in which the portion below −100 nm is a white region. Note that details of the surface shape evaluation test will be explained in Examples described later.

In the two-dimensional image before binarization, among the depressions existing on the surface of the first adhesive layer opposite to the first base material, the depressions have a depth exceeding the detection limit of the white interferometer. The portion becomes a black area, and the portion that does not correspond to the black area becomes a white area. The area B-BA of the black area in the two-dimensional image before binarization is, for example, 1.5% or less, preferably 0.3% or less, when the measurement field area S of the white interferometer is 100%. It is preferably 0.2% or less, more preferably 0.1% or less, and typically 0% or more.

In the two-dimensional image after binarization (hereinafter sometimes referred to as a binarized image), the part corresponding to -100 nm or less with respect to the measurement surface becomes a white region, and the other part (with respect to the measurement surface) becomes a white region. (exceeding −100 nm) becomes a black region. The area A-WA of the white region in the binarized image is, for example, 1.3% or less, preferably 0.2% or less, more preferably 0.2% or less, when the measurement field area S of the white interferometer is 100%. It is 1% or less, more preferably 0.08% or less, and typically 0% or more.

The surface of the first adhesive layer opposite to the first base material before being attached to the optical laminate has a shape that satisfies the above formula (1), preferably formula (2), and more preferably formula (3). If it has, even if the surface protection film is subjected to defect inspection (for example, bubble inspection) with the surface protection film attached to the optical laminate, false detections caused by the surface protection film can be suitably reduced.

The first adhesive layer typically contains at least one type of adhesive selected from the group consisting of (meth)acrylic adhesives, urethane adhesives, and silicone adhesives. Preferably, the first adhesive layer contains a (meth)acrylic adhesive.

The (meth)acrylic pressure-sensitive adhesive contains a polymer (hereinafter referred to as (meth)acrylic polymer) of a monomer component whose main component is alkyl (meth)acrylate. In other words, the (meth)acrylic polymer contains a structural unit derived from alkyl (meth)acrylate. The content of structural units derived from alkyl (meth)acrylate is typically 50% by mass or more, preferably 80% by mass or more, more preferably 93% by mass or more, for example 100% by mass or more, preferably 80% by mass or more, and more preferably 93% by mass or more in the (meth)acrylic polymer. It is not more than 98% by mass, preferably not more than 98% by mass.

The alkyl group that the alkyl (meth)acrylate has 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 methyl group, ethyl group, butyl group, 2-ethylhexyl group, decyl group, isodecyl group, and octadecyl group. 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.

In addition to structural units derived from alkyl (meth)acrylates, the (meth)acrylic polymer may also contain structural units derived from copolymerizable monomers that are polymerizable with alkyl (meth)acrylates. Examples of the copolymerizable monomer include carboxyl group-containing monomers and hydroxyl group-containing monomers. Copolymerizable monomers can be used alone or in combination.

A carboxyl group-containing monomer is a compound that contains a carboxyl group in its structure and also contains 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, with (meth)acrylic acid being preferred. When the (meth)acrylic polymer contains a structural unit derived from a carboxyl group-containing monomer, the adhesive properties of the adhesive layer can be improved. When the (meth)acrylic polymer contains a structural unit derived from a carboxyl group-containing monomer, the content ratio 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.

A hydroxyl group-containing monomer is a compound that contains a hydroxyl group in its structure and also contains a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. Examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4-hydroxymethyl cyclohexyl)-methyl acrylate, preferably 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, more preferably 2-hydroxyethyl (meth)acrylate. When the (meth)acrylic polymer contains a structural unit derived from a hydroxyl group-containing monomer, the durability of the 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 is preferably 0.01% by mass or more and 10% by mass in the (meth)acrylic polymer. % or less.

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

Additionally, the (meth)acrylic pressure-sensitive adhesive can contain a crosslinking agent. The crosslinking agent typically includes an organic crosslinking agent and a polyfunctional metal chelate, preferably an organic crosslinking agent. Examples of the organic crosslinking agent include an isocyanate crosslinking agent, a peroxide crosslinking agent, an epoxy crosslinking agent, and an imine crosslinking agent, and more preferably an isocyanate crosslinking agent. When the adhesive contains a crosslinking agent, the content of the crosslinking agent is usually 0.01 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the (meth)acrylic polymer.

The above adhesives ((meth)acrylic adhesives, urethane adhesives, and silicone adhesives) may contain various additives in appropriate proportions, if necessary. By adjusting the composition of the base polymer (for example, the type and content ratio of monomers, the type and content ratio of crosslinking agents, etc.), the molecular weight of the base polymer, and the type or content ratio of additives, An adhesive layer having desired adhesiveness can be obtained.

Additives include polymerization initiators, solvents, polymerization catalysts, crosslinking catalysts, silane coupling agents, tackifiers, plasticizers, softeners, deterioration inhibitors, fillers, colorants (pigments, dyes, etc.), and ultraviolet rays. Examples include absorbents, antioxidants, surfactants, antistatic agents, chain transfer agents, and the like.

The thickness of the first 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.

The first adhesive layer may be formed on the surface of the first base material by direct copying or by transfer. In the case of direct copying, the adhesive is directly applied to the surface of the first base material to form the first adhesive layer. In the case of transfer, a first adhesive layer is formed by applying an adhesive to the surface of a release liner, and then a base material is attached to the first adhesive layer. In particular, when the first base material includes an amorphous resin having a relatively low glass transition temperature Tg (for example, 150° C. or lower), the first adhesive layer is preferably formed by a transfer process. With the transfer process, it is possible to prevent the high temperature during drying required for forming the first adhesive layer from affecting the first base material.

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

A release treatment layer may be provided on the surface of the release liner 116 that contacts the surface 114a of the first adhesive layer 114. Examples of the mold release agent forming the mold release treatment layer include silicone-based mold release agents, fluorine-based mold release agents, and long-chain alkyl acrylate-based mold release agents, and preferably silicone-based mold release agents. Examples include vinyl group-containing addition type silicones, and more preferably vinyl group-containing addition type silicones. The mold 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.

The contact surface of the release liner 116 with the surface 114a of the first adhesive 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 adhesive layer 114 is typically 500 nm or less, preferably 400 nm or less, more preferably 300 nm or less, and Preferably it is 100 nm or less. If the absolute value of the maximum peak height (Sp) on the contact surface is below the above upper limit, the maximum valley depth (Sv) on the surface opposite to the first base material in the first adhesive layer is stabilized below the above upper limit. can be adjusted. Further, if the absolute value of the maximum peak height (Sp) on the contact surface is below the above upper limit, the surface of the first adhesive layer on the opposite side to the first base material is stabilized so as to satisfy the above formula (1). can be adjusted. The absolute value of the maximum peak height (Sp) on the contact surface is typically 10 nm or more. Note that the maximum peak height (Sp) can be measured in accordance with JIS B0681-2:2018.

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

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. In addition, when a mold release treatment layer is applied, the thickness of the release liner is the thickness including the thickness of the mold release treatment layer.

A-2. Second Surface Protection Film As shown in FIG. 1, the second surface protection film 120 includes a second base material 122 and a second adhesive layer 124 laminated on the second base material. Similar to the first surface protection film, a release liner is attached (temporarily attached) to the second adhesive layer until the second surface protection film is put into use. is protected.

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

The 90° trigger peeling force of the second surface protection film against the first surface protection film (the surface of the first surface protection film on the first base material side) is, for example, 0.01N to 0.20N, preferably 0.03N to 0.01N. 15N, more preferably 0.05N to 0.12N. The 180° triggered peeling force of the second surface protection film against the first surface protection film (the surface of the first surface protection film on the first base material side) is, for example, 0.01N to 0.20N, preferably 0.03N to 0.2N. 15N, more preferably 0.05N to 0.12N.

The normal peeling force (peel angle 180°, tensile speed 300 mm/min) of the second surface protection film against the first surface protection film (the surface of the first surface protection film on the first substrate side) is, for example, 0.01 N/25 mm to 0.2N/25mm, preferably 0.03N/25mm to 0.15N/25mm, more preferably 0.05N/25mm to 0.1N/25mm.

<Second base material>
The second base material 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 regarding the first base material.

The second base material may contain antioxidants, ultraviolet absorbers, light stabilizers, nucleating agents, fillers, pigments, surfactants, antistatic agents, and the like. The surface of the second base material (the surface opposite to the second adhesive layer) is provided with an easy-adhesion layer, an easy-slip layer, an anti-blocking layer, an antistatic layer, an anti-reflection layer, an anti-oligomer layer, etc. Good too.

The thickness of the second base material is typically 5 μm or more, preferably 20 μm or more, and typically 200 μm or less, preferably 100 μm or less.

<Second adhesive layer>
The second adhesive layer typically contains at least one type of adhesive selected from the group consisting of (meth)acrylic adhesives, urethane adhesives, and silicone adhesives. Preferably, the second adhesive layer contains a (meth)acrylic adhesive. The details of the (meth)acrylic adhesive are as described above regarding the first adhesive layer.

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

The thickness of the second adhesive layer is typically 1 μm or more, preferably 5 μm or more, and typically 30 μm or less, preferably 15 μm or less.

The method for forming the second adhesive layer includes the same method as the method for forming the first adhesive layer.

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 polarizing members (absorbing polarizing member, reflective polarizing member), retardation members, and the like.

A-3-1. Display system to which the optical laminate can be applied FIG. 3 is a schematic diagram showing a general configuration of a display system (goggles with a display) to which the optical laminate can be applied. FIG. 3 schematically shows the arrangement, shape, etc. of each component of the display system 2. As shown in FIG. The display system 2 includes a display element 12, a reflective polarizing member 14, a first lens section 16, a half mirror 18, a first retardation member 20, a second retardation member 22, and a second lens section 24. It is equipped with The reflective polarizing member 14 is disposed at the front of the display element 12 on the display surface 12a side, and can reflect light emitted from the display element 12. The first lens section 16 is arranged on the optical path between the display element 12 and the reflective polarizing member 14, and the half mirror 18 is arranged between the display element 12 and the first lens section 16. The first retardation member 20 is arranged on the optical path between the display element 12 and the half mirror 18, and the second retardation member 22 is arranged on the optical path between the half mirror 18 and the reflective polarizing member 14. There is. Although not shown, the display system 2 may further include an absorptive polarizing member between the reflective polarizing member 14 and the second lens section 24.

The components disposed in front of the half mirror (in the illustrated example, the half mirror 18, the first lens section 16, the second retardation member 22, the reflective polarizing member 14, and the second lens section 24) are collectively assembled into a lens section ( It may also be referred to as a lens section 4).

The display element 12 is, for example, a liquid crystal display or an organic EL display, and has a display surface 12a for displaying images. For example, 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 emitted as first linearly polarized light.

The first retardation member 20 includes a first λ/4 member that can convert the first linearly polarized light incident on the first retardation member 20 into first circularly polarized light. When the first retardation member does not include any member other than the first λ/4 member, the first retardation member may correspond to the first λ/4 member. The first retardation member 20 may be provided integrally with the display element 12.

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

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

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

The second linearly polarized light reflected by the reflective polarizing member 14 is converted into second circularly polarized light by the second λ/4 member included in the second retardation member 22, and is emitted from the second λ/4 member. The second circularly polarized light passes through the first lens section 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 section 16 and is converted into third linearly polarized light by the second λ/4 member included in the second retardation member 22. The third linearly polarized light is transmitted through the reflective polarizing member 14 . At this time, the polarization direction of the third linearly polarized light incident on the reflective polarizing member 14 is the same direction as the transmission axis of the reflective polarizing member 14. Therefore, the third linearly polarized light incident on the reflective polarizing member 14 is transmitted through the reflective polarizing member 14.

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

For example, the absorption axis of the polarizing member 10 and the reflection axis of the reflective polarizing member 14 included in the display element 12 may be arranged substantially parallel to each other, or may be arranged substantially perpendicular to each other. The angle 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°, and 42°. ˜48°, and may be about 45°. The angle between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the second λ/4 member included in the second retardation member 22 is, for example, 40° to 50°, and 42° to 50°. It may be 48° or about 45°.

In the lens portion 4, a space may be formed between the first lens portion 16 and the second lens portion 24. In this case, the member disposed between the first lens section 16 and the second lens section 24 is preferably provided integrally with either the first lens section 16 or the second lens section 24. For example, it is preferable that the member disposed between the first lens part 16 and the second lens part 24 be integrated with either the first lens part 16 or the second lens part 24 via an adhesive layer. According to such a configuration, for example, each member can be easily handled. The adhesive layer may be formed of an adhesive or a pressure-sensitive adhesive. Specifically, the adhesive layer may be an adhesive layer or an adhesive layer. The thickness of the adhesive layer is, for example, 0.05 μm to 30 μm.

A-3-2. Configuration of Optical Laminate FIG. 4 is a schematic cross-sectional view of an optical layered body that can be used in the display system illustrated in FIG. 3. The optical laminate 100a includes an adhesive layer 31, a polarizing member 10, a first retardation member 20, and a first protective member 41 in this order. The polarizing member 10, the first retardation member 20, and the first protection member 41 are laminated with

adhesive layers

51 and 52 interposed therebetween. The adhesive layers 51 and 52 are typically adhesive layers or adhesive layers, preferably adhesive layers. The thickness of the adhesive layer is, for example, 0.05 μm to 30 μm. The surface of the adhesive layer 31 is protected by a release liner 61 until it is used. Note that the first surface protection film and the second surface protection film are attached to the surface of the optical laminate 100a on the first protection member 41 side.

In the example shown in FIG. 4, the first retardation 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. Contains. The first retardation member 20 has a laminated structure of a first λ/4 member 20a and a first positive C plate 20b. As shown in the illustrated example, it is preferable that the first λ/4 member 20a is located closer to the polarizing member 10 than the first positive C plate 20b, but these arrangements may be reversed. Furthermore, the first positive C plate 20b may 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). Further, in the first retardation 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 The angle is 48°, for example about 45°.

The optical laminate 100a can be applied, for example, to manufacturing a display system illustrated in FIG. 3, in which the first retardation member 20 is integrally provided with the display element 12. For example, the release liner 61 is peeled off from the optical laminate 100a, and the polarizing member 10 is attached to the liquid crystal cell together with the back side polarizing member so that the polarizing member 10 becomes the front side (viewing side) polarizing member of the liquid crystal cell. A display system in which the retardation member 20 is integrally provided with a liquid crystal panel (display element) can be manufactured. Further, for example, the first retardation member 20 is integrated with the organic EL panel (display element) by peeling off the release liner 61 from the optical laminate 100a and bonding it to the front of the organic EL panel via the adhesive layer 31. A display system can be manufactured that is provided with a display system. In this case, from the viewpoint of antireflection, a third retardation member including a third λ/4 member may be disposed between the optical laminate 100a and the organic EL panel. The third retardation member may be included in the optical laminate. For example, the optical laminate may include an adhesive layer, a third retardation member, a polarizing member, a first retardation member, and a protection 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 is configured such that the slow axis of the third λ/4 member makes an angle of, for example, 40° to 50°, 42° to 48°, or about 45° with the absorption axis of the polarizing member 10. may be placed.

<Polarizing member>
The polarizing member 10 is typically an absorption type polarizing member including a resin film containing a dichroic substance (sometimes referred to as an absorption type polarizing film), and if necessary, a protective layer is provided on one or both sides thereof. may further include. The protective layer is typically bonded to the absorption polarizing film via any suitable adhesive layer. A typical example of the adhesive forming the adhesive layer is an ultraviolet curable adhesive.

The orthogonal transmittance (Tc) of the absorption type polarizing member (absorption type polarizing film) is preferably 0.5% or less, more preferably 0.1% or less, and still more preferably 0.05% or less. be. The single transmittance (Ts) of the absorption type polarizing member (absorption type polarizing film) is, for example, 41.0% to 45.0%, preferably 42.0% or more. The degree of polarization (P) of the absorption type polarizing member (absorption type polarizing film) is, for example, 99.0% to 99.997%, preferably 99.9% or more.

The above-mentioned orthogonal transmittance, single transmittance, and degree of polarization can be measured using, for example, an ultraviolet-visible spectrophotometer. The degree of polarization P can be determined by measuring the single transmittance Ts, parallel transmittance Tp, and cross transmittance Tc using an ultraviolet-visible spectrophotometer, and from the obtained Tp and Tc using the following formula. Note that Ts, Tp, and Tc are Y values measured using a 2-degree field of view (C light source) according to JIS Z8701 and subjected to visibility correction.
Polarization degree P (%) = {(Tp-Tc)/(Tp+Tc)} ^1/2 ×100

The thickness of the absorption type polarizing film is, for example, 1 μm or more and 20 μm or less, may be 2 μm or more and 15 μm or less, may be 12 μm or less, may be 10 μm or less, or may be 8 μm or less, It may be 5 μm or less.

The above-mentioned absorption type polarizing film may be produced from a single layer resin film, or may be produced using a laminate of two or more layers.

When manufacturing from a single-layer resin film, for example, 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 is coated with iodine or dichloromethane. An absorption type polarizing film can be obtained by performing a dyeing treatment with a dichroic substance such as a color dye, a stretching treatment, and the like. Among these, an absorption type polarizing film obtained by dyeing a PVA film with iodine and uniaxially stretching it is preferred.

The above-mentioned staining with iodine is performed, for example, by immersing the PVA-based film in an iodine aqueous solution. The stretching ratio of the above-mentioned uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after the dyeing process or may be performed while dyeing. Alternatively, it may be dyed after being stretched. If necessary, the PVA film is subjected to swelling treatment, crosslinking treatment, washing treatment, drying treatment, etc.

The laminate produced using the above-mentioned laminate of two or more layers is a laminate of a resin base material and a PVA resin layer (PVA resin film) laminated on the resin base material, or a laminate of a resin base material and a PVA resin layer (PVA resin film) laminated on the resin base material, or Examples include a laminate of a material and a PVA-based resin layer formed by coating on the resin base material. An absorption type polarizing film obtained by using a laminate of a resin base material and a PVA resin layer coated on the resin base material can be obtained by, for example, applying a PVA resin solution to the resin base material, drying it, and applying the resin. Forming a PVA-based resin layer on a base material to obtain a laminate of the resin base material and the PVA-based resin layer; stretching and dyeing the laminate to make the PVA-based resin layer an absorption type polarizing film. can be produced by; In this embodiment, preferably, a polyvinyl alcohol resin layer containing a halide and a polyvinyl alcohol resin is formed on one side of the resin base material. Stretching typically includes immersing the laminate in an aqueous boric acid solution and stretching. Furthermore, the stretching may further include stretching the laminate in air at a high temperature (for example, 95° C. or higher) before stretching in the boric acid aqueous solution, if necessary. In addition, in the present embodiment, the laminate is preferably subjected to a drying shrinkage treatment in which the laminate is heated while being conveyed in the longitudinal direction to shrink 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 process, a dyeing process, an underwater stretching process, and a drying shrinkage process in this order. By introducing auxiliary stretching, even when PVA is applied onto a thermoplastic resin, it becomes possible to improve the crystallinity of PVA and achieve high optical properties. At the same time, by increasing the orientation of PVA in advance, it is possible to prevent problems such as deterioration of orientation and dissolution of PVA when it is immersed in water during the subsequent dyeing and stretching processes, resulting in high optical properties. becomes possible to achieve. Furthermore, when the PVA-based resin layer is immersed in a liquid, disturbance in the orientation of polyvinyl alcohol molecules and deterioration of orientation can be suppressed compared to when the PVA-based resin layer does not contain a halide. Thereby, the optical properties of an absorption polarizing film obtained through a treatment process performed by immersing the laminate in a liquid, such as dyeing treatment and underwater stretching treatment, can be improved. Furthermore, optical properties can be improved by shrinking the laminate in the width direction by drying shrinkage treatment. The obtained resin base material/absorption type polarizing film laminate may be used as is (that is, the resin base material may be used as a protective layer of the absorption type polarizing film), or the resin base material/absorption type polarizing film laminate may be used as is. Any suitable protective layer depending on the purpose may be laminated on the peeled surface from which the resin base material is peeled off, or on the surface opposite to the peeled surface. Details of the manufacturing method of such an absorption type polarizing film are described in, for example, Japanese Patent Application Publication No. 2012-73580 and Japanese Patent No. 6470455. The entire descriptions of these publications are incorporated herein by reference.

The protective layer is formed of any suitable film that can be used as a protective layer of an absorption polarizing film. Specific examples of materials that are the main components of the film include cycloolefin (COP) systems such as polynorbornene systems, polyester systems such as polyethylene terephthalate (PET) systems, cellulose resins such as triacetyl cellulose (TAC), and polycarbonate. Examples include transparent resins such as (PC), (meth)acrylic, polyvinyl alcohol, polyamide, polyimide, polyethersulfone, polysulfone, polystyrene, polyolefin, and acetate. Further, thermosetting resins or ultraviolet curable resins such as (meth)acrylic, urethane, (meth)acrylic urethane, epoxy, and silicone resins may also be mentioned. Note that "(meth)acrylic resin" refers to acrylic resin and/or methacrylic resin. Other examples include glassy polymers such as siloxane polymers. Furthermore, the polymer film described in JP-A-2001-343529 (WO01/37007) can also be used. Materials for this film include, for example, a resin composition containing a thermoplastic resin having a substituted or unsubstituted imide group in its side chain, and a thermoplastic resin having a substituted or unsubstituted phenyl group and nitrile group in its side chain. For example, a resin composition containing an alternating copolymer of isobutene and N-methylmaleimide and an acrylonitrile/styrene copolymer can be used. The polymer film may be, for example, an extrusion molded product of the resin composition. The materials for the resin film can be used alone or in combination.

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.

<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. Good too. The first λ/4 member preferably exhibits inverse dispersion wavelength characteristics in which the retardation value increases depending on 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.

The first λ/4 member preferably exhibits a refractive index characteristic of nx>ny≧nz. Here, "ny=nz" includes not only the case where ny and nz are completely equal, but also the case where ny and nz are substantially equal. Therefore, there may be a case where ny<nz within a range that does not impair the effects of the present invention. The Nz coefficient of the first λ/4 member is preferably 0.9 to 3, more preferably 0.9 to 2.5, even more preferably 0.9 to 1.5, and particularly preferably is 0.9 to 1.3.

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

The resins contained in the above resin film include polycarbonate resin, polyester carbonate resin, polyester resin, polyvinyl acetal resin, polyarylate resin, cyclic olefin resin, cellulose resin, polyvinyl alcohol resin, and polyamide resin. , polyimide resin, polyether resin, polystyrene resin, acrylic resin, and the like. These resins may be used alone or in combination. Examples of the combination method 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) may be suitably used.

Any suitable polycarbonate resin can be used as the polycarbonate resin. For example, polycarbonate resins contain structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, alicyclic diols, alicyclic dimethanols, di-, tri-, or polyethylene glycols, and alkylene-based dihydroxy compounds. a structural unit derived from at least one dihydroxy compound selected from the group consisting of glycol or spiroglycol. Preferably, the polycarbonate resin contains a structural unit derived from a fluorene dihydroxy compound, a structural unit derived from an isosorbide dihydroxy compound, a structural unit derived from an alicyclic dimethanol, and/or a di, tri, or polyethylene glycol. More preferably, it contains a structural unit derived from a fluorene dihydroxy compound, a structural unit derived from an isosorbide dihydroxy compound, and a structural unit derived from di, tri or polyethylene glycol. . The polycarbonate resin may contain structural units derived from other dihydroxy compounds as necessary. In addition, details of the polycarbonate resin that can be suitably used for the first λ/4 member and the method for forming the first λ/4 member can be found in, for example, JP 2014-10291A and JP 2014-26266A. , JP 2015-212816, A, JP 2015-212817, and JP 2015-212818, and the descriptions of these publications are incorporated herein by reference.

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.

The liquid crystal compound alignment and 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. In addition, the "alignment hardened layer" is a concept that includes an orientation hardened layer obtained by curing a liquid crystal monomer as described below. In the first λ/4 member, rod-shaped liquid crystal compounds are typically 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.

The liquid crystal compound alignment and solidification layer (liquid crystal alignment solidification layer) is produced by subjecting the surface of a predetermined base material to an alignment treatment, applying a coating liquid containing the liquid crystal compound to the surface, and subjecting the liquid crystal compound to the alignment treatment. It can be formed by orienting it in a corresponding direction and fixing the orientation state. Any suitable orientation treatment may be employed as the orientation treatment. Specifically, mechanical alignment treatment, physical alignment treatment, and chemical alignment treatment can be mentioned. 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 photo alignment treatment. As the treatment conditions for various orientation treatments, any appropriate conditions may be adopted depending on the purpose.

The alignment of the liquid crystal compound is carried out by treatment at a temperature that exhibits a liquid crystal phase depending on the type of liquid crystal compound. By performing such temperature treatment, the liquid crystal compound assumes a liquid crystal state, and the liquid crystal compound is oriented in accordance with the orientation treatment direction of the substrate surface.

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 polymerization treatment or crosslinking treatment.

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 may be used alone or in combination. Specific examples of liquid crystal compounds and methods for producing liquid crystal alignment solidified layers are described in, for example, JP 2006-163343A, JP 2006-178389A, and WO 2018/123551A. The descriptions of these publications are incorporated herein by reference.

The thickness of the first λ/4 member composed 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 still more preferably 1 μm to 4 μm. be.

<First positive C plate>
The retardation Rth (550) in the thickness direction of the first positive C plate 20b is preferably -50 nm to -300 nm, more preferably -70 nm to -250 nm, and still more preferably -90 nm to -200 nm. , particularly preferably -100 nm to -180 nm. Here, "nx=ny" includes not only the case where nx and ny are strictly equal, but also the case where nx and ny are substantially equal. The in-plane retardation Re (550) of the first positive C plate is, for example, less than 10 nm.

The first positive C-plate may be formed of any suitable material. The first positive C-plate preferably consists of a film containing liquid crystal material fixed in a homeotropic orientation. 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 the method for forming such a liquid crystal compound and positive C plate include the method for forming the liquid crystal compound and the retardation layer described in [0020] to [0028] of JP-A No. 2002-333642. In this case, the thickness of the first positive C plate is preferably 0.5 μm to 5 μm.

<First protection member>
The first protection member 41 typically includes a base material. The substrate may be comprised of any suitable film. Materials that are the main components of the film constituting the base material include, for example, cellulose resins such as triacetyl cellulose (TAC), polyesters, polyvinyl alcohols, polycarbonates, polyamides, polyimides, polyethersulfones, Examples include polysulfone-based, polystyrene-based, cycloolefin-based resins such as polynorbornene, polyolefin-based resins, (meth)acrylic-based resins, and acetate-based resins. The thickness of the base material is preferably 5 μm to 80 μm, more preferably 10 μm to 40 μm, and even more preferably 15 μm to 35 μm.

The first protective member preferably has a base material and a surface treatment layer formed on the base material. The first protection member having the surface treatment layer may be arranged such that the surface treatment layer is located on the front side. Specifically, the surface treatment layer may be located on the outermost surface of the optical laminate 100a. The surface treatment layer may have any suitable function. Examples of the surface treatment layer include a hard coat layer, an antireflection layer, an antisticking layer, and an antiglare layer. The first protection member may have two or more surface treatment layers. The water contact angle on the surface of the surface treatment layer may be, for example, 90° or more and 125° or less, or, for example, 100° or more and 115° or less.

The antireflection layer is provided to prevent reflection of external light and the like. Examples of the antireflection layer include a fluororesin layer, a resin layer containing nanoparticles (typically hollow nanoparticles, such as hollow nanosilica particles), or an antireflection layer having a nanostructure (e.g. 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 thermosetting method using isocyanate, and an ionizing radiation curing method using a crosslinking monomer (e.g., polyfunctional acrylate) and a photopolymerization initiator (typically a photopolymerization method). curing method). In one embodiment, the antireflection layer is provided on the outermost surface of the first protective member, and the first surface protection film is attached to the surface of the antireflection layer. According to the embodiment in which the antireflection layer is provided on the outermost surface of the first protective member, an excellent antireflection effect can be achieved in a display system in which a space is formed between the half mirror 18 and the first retardation member 20. Obtainable.

The hard coat layer preferably has sufficient surface hardness, excellent mechanical strength, and excellent light transparency. The hard coat layer may be formed from any suitable resin. The hard coat layer is typically formed from an ultraviolet curable resin. Examples of the ultraviolet curable resin include polyester, acrylic, urethane, amide, silicone, and epoxy 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.

<Adhesive layer>
Adhesive layer 31 may be composed of any suitable 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 blending ratio of monomers that form the base resin of the adhesive, as well as the amount of crosslinking agent, reaction temperature, reaction time, etc., adhesives can have desired characteristics depending on the purpose. can be prepared. The base resin of the adhesive may be used alone or in combination of two or more types. As the base resin, acrylic resin is preferably used. Specifically, the adhesive layer is preferably composed of an acrylic adhesive.

The thickness of the 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.

<Release liner>
Release liner 61 is formed of any suitable resin film. Specific examples of the material that is the main component of the resin film include polyethylene terephthalate (PET), polyethylene, and polypropylene. The materials for the resin film can be used alone or in combination. The release liner may be transparent (eg, haze of 5% or less, and such as 3% or less) or non-transparent.

A release treatment layer may be provided on the surface of the release liner 61 that comes into contact with the adhesive layer 31. Examples of the mold release treatment agent forming the mold release treatment layer include silicone mold release treatment agents, fluorine mold release treatment agents, and long chain alkyl acrylate type mold release treatment agents. The mold 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.

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. In addition, when a mold release treatment layer is applied, the thickness of the release liner is the thickness including the thickness of the mold release treatment layer.

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

In the example shown in FIG. 5, the second retardation 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 exhibit the relationship nz>nx=ny. Contains. The second retardation member 22 has a laminated structure of a second λ/4 member 22a and a second positive C plate 22b. As shown in the illustrated example, it is preferable that the second λ/4 member 22a is located closer to the second protection member 42 than the second positive C plate 22b, but these arrangements may be reversed. . Further, the second positive C plate 22b may be omitted. The second λ/4 member 22a and the second positive C plate 22b are laminated, for example, via an adhesive layer (not shown).

The optical laminate 100b can be applied, for example, to manufacturing a display system in an embodiment in which the second retardation member 22 is integrally provided with the first lens portion 16 in the display system illustrated in FIG. Specifically, by peeling off the release liner 62 from the optical laminate 100b and bonding it to the first lens part 16 via the adhesive layer 32, the second retardation member 22 is integrally attached to the first lens part 16. A display system provided can be manufactured.

<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. Good too. The second λ/4 member preferably exhibits inverse dispersion wavelength characteristics in which the retardation value increases depending on 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.

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 completely equal, but also the case where ny and nz are substantially equal. Therefore, there may be a case where ny<nz within a range that does not impair the effects of the present invention. The Nz coefficient of the second λ/4 member is preferably 0.9 to 3, more preferably 0.9 to 2.5, even more preferably 0.9 to 1.5, and particularly preferably is 0.9 to 1.3.

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

<Second positive C plate>
The retardation Rth (550) in the thickness direction of the second positive C plate 22b is preferably -50 nm to -300 nm, more preferably -70 nm to -250 nm, and still more preferably -90 nm to -200 nm. , particularly preferably -100 nm to -180 nm. Here, "nx=ny" includes not only the case where nx and ny are strictly equal, but also the case where nx and ny are substantially equal. The in-plane retardation Re (550) of the second positive C plate is, for example, less than 10 nm.

The second positive C plate is formed of any suitable 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 (for example, forming material, thickness, optical properties, etc.) or may have different configurations.

<Second protection member>
The second protection member 42 typically includes a base material, and preferably includes a base material and a surface treatment layer formed on the base material. In this case, the surface treatment layer may be located on the outermost surface of the optical laminate 100b. Regarding the details of the base material and the surface treatment layer, the same explanation as for the first protective member can be applied. According to an embodiment in which an antireflection layer is provided as a surface treatment layer on the outermost surface of the second protection member 42, the second retardation member 22 is integrated with the first lens portion 16, and the reflective polarizing member 14 is integrated with the second protection member 42. In a display system that is integrated with the lens portion 24 and a space is formed between them, an excellent antireflection effect can be obtained.

The same explanation as for the adhesive layer 31 and release liner 61 used in the optical laminate 100a can be applied to the adhesive layer 32 and release liner 62 used in the optical laminate 100b, respectively.

B. Method for manufacturing a display system 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 protection film described in Section A. A method for manufacturing a display system according to an embodiment of the present invention includes peeling off the second surface protection film from the optical laminate with a surface protection film described in Section A, and producing an optical laminate to which only the first surface protection film is attached. and inspecting for defects an object to be inspected in which an optical laminate to which only the first surface protection film is attached is bonded to another member. The second surface protection film may be peeled off before or after the production of the object to be inspected (that is, bonding the optical laminate with the surface protection film to another member).
A method of manufacturing a display system according to one embodiment of the present invention includes:
Another member is pasted on the side opposite to the side to which the first surface protection film and the second surface protection film of the optical laminate with a surface protection film according to item A are pasted, to form a secondary surface protection film-attached optical laminate. obtaining a laminate;
Peeling the second surface protection film from the surface protection film-attached secondary laminate;
inspecting the secondary laminate with the surface protection film for defects; and peeling the first surface protection film from the secondary laminate with the surface protection film to obtain a secondary laminate;
In this order.
The obtained secondary laminate is subjected to an assembly process and assembled with other members to form a display system. Hereinafter, an example of a method for manufacturing the display system of the present invention will be described with reference to FIG. 6.

The optical laminate 200 with a surface protection film shown in FIG. 6A has the optical laminate 100a illustrated in FIG. The protective film 120 is pasted outward in this order. 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 protection film is processed into a desired shape by cutting, punching, machining, or the like.
As shown in FIG. 6B, the release liner 61 is peeled off from the optical laminate 200 with a surface protection film, and the viewing side of the optical member (e.g., liquid crystal cell, organic EL panel) 300 ( (front) surface to obtain a secondary laminate 400a with a surface protection film.
Next, as shown in FIG. 6C, the second surface protection film 120 is peeled off from the surface protection film-attached secondary laminate 400a to obtain a surface protection film-attached secondary laminate 400b.
Next, as shown in FIG. 6D, a defect inspection is performed on the surface protection film-equipped secondary laminate 400b whose surface is protected by the first surface protection film 110.
Next, as shown in FIG. 6E, the first surface protection film 110 is peeled off from the surface protection film-attached secondary laminate 400b, which was determined to be good in the defect inspection, to obtain a secondary laminate 400c. The secondary laminate 400c is used for assembly of a display system.

According to the above manufacturing method, it is possible to suitably prevent scratches, foreign matter, dirt, etc. from adhering to the surface of the optical laminate until immediately before it is incorporated into the display system, and it is also possible to conduct precise defect inspection on the optical member immediately before it is incorporated into the display system. It can be performed. Such an effect is particularly advantageous when processes such as manufacturing the optical laminate, manufacturing the display element, and assembling the display system are performed at different locations. In one embodiment, the optical laminate is shipped to a display element manufacturer as a first semi-finished product in the state of an optical laminate with a surface protection film to which two surface protection films are attached (for example, FIG. 6A). ; By pasting the optical laminate with a surface protection film on an optical member such as a liquid crystal cell or an organic EL element, the display element (liquid crystal panel, organic EL panel, etc.) to which the optical laminate with a surface protection film is pasted can be produced. ) is obtained (for example, FIG. 6B); from here, the second surface protection film is peeled off, and the display element is inspected for defects with the surface protected by the first surface protection film (for example, 6C and D); Display elements determined to be non-defective in the defect inspection are shipped to a display system manufacturer as a second semi-finished product with the first surface protection film attached; After peeling off the surface protection film, it can be assembled with other components (eg, FIG. 6E). According to the manufacturing method of the present embodiment, defects (scratches, foreign objects, dirt, etc.) can be prevented when shipping the first semi-finished product, defect inspection can be performed when manufacturing the second semi-finished product, and It is possible to suitably prevent defects (scratches, foreign objects, dirt, etc.) when shipping semi-finished products, and as a result, it can contribute to efficient production of final products.

The method of manufacturing the display system is not limited to the illustrated example. For example, the second surface protection film may be peeled off before the release liner is peeled off and attached to the optical member, and the defect inspection may be performed before the release liner is attached to the optical member. For example, after the second surface protection film and release liner are peeled off and the optical laminate with only the first surface protection film attached is inspected for defects, the optical laminate can be bonded to the optical member. For example, after peeling off the second surface protection film and inspecting the optical laminate with the first surface protection film and release liner attached, the release liner is peeled off and the optical laminate is attached to the optical member. Can be matched.

Defect inspection may be performed by automated optical inspection (AOI), visual inspection, etc. Preferably, the defect inspection includes automated optical inspection (AOI). Defect inspection may be performed using a transmission optical system, a reflection optical system, or a combination thereof depending on the purpose.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples. Note that the thickness is a value measured by the following measuring method.
<Thickness>
The thickness of 10 μm or less was measured using a scanning electron microscope (manufactured by JEOL Ltd., product name “JSM-7100F”). Thickness exceeding 10 μm was 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 is peeled off from the adhesive layer, and light is irradiated from the base material side of the surface protection film using a haze meter ("NDH-5000" manufactured by Nippon Denshoku Industries Co., Ltd.) to meet JIS K7136. Haze was measured according to .

[Production Example 1A: Production of surface protection film A]
<Acrylic polymer A>
In a reaction vessel equipped with a thermometer, a stirrer, a cooler, and a nitrogen gas introduction tube, 96.2 parts by mass of 2-ethylhexyl acrylate (2EHA) and 3.8 parts by mass of hydroxyethyl acrylate (HEA) were placed as monomer components. 0.2 parts by mass of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator was charged together with 150 parts by mass of ethyl acetate, and nitrogen gas was introduced while stirring gently at 23°C to perform nitrogen substitution. Ta. Thereafter, a polymerization reaction was carried out for 6 hours while maintaining the liquid temperature at around 65° C. to prepare a solution of acrylic polymer A (concentration: 40% by mass). The weight average molecular weight of acrylic polymer A was 540,000.

<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 dibutyltin dilaurate (1% by mass ethyl acetate) as a crosslinking catalyst. Solution) 3 parts by mass (solid content: 0.03 parts by mass) were added and stirred to prepare adhesive composition A.

<Surface protection film A>
Adhesive composition A was applied to one side of a base material (PET film, "CE905-38" manufactured by KOLON, thickness 38 μm), and then dried to form an adhesive layer (thickness 15 μm). Next, a release liner (manufactured by Toyobo Co., Ltd., product number TG704) was attached to the surface of the adhesive layer opposite to the base material. As a result, surface protection film A was obtained. The haze of surface protection film A was 1.8%.

[Production Example 1B: Production of surface protection film B]
An 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, thickness: 38 μm) was used as the base material. Next, a release liner (manufactured by Toyobo Co., Ltd., product number TG704) was attached to the surface of the adhesive layer opposite to the base material. As a result, surface protection film B was obtained. The haze of surface protection film B was 3.9%.

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

Regarding the surface protection film B and the release liner used in its production, the following evaluations (1) to (5) were performed.
(1) Surface shape evaluation test of adhesive layer In the surface protection film, the release liner was peeled off from the adhesive layer to expose the surface of the adhesive layer on the side opposite to the base material.
Next, the surface protective film from which the release liner was removed was set in a white interferometer (manufactured by Zygo, trade name: Zygo NewView 7300) so that the exposed surface of the adhesive layer faced the objective lens, and the surface of the adhesive layer was exposed. Interference data was measured under the following conditions.
Measurement conditions for white interferometer:
Objective lens; ×10
Internal lens; ×1.0
Resolution: 1.09μm
Measurement visual field area (S): 0.3641mm ²
Removed; Cylinder
The obtained interference data is calculated in the analysis range (depth direction) from -1000 nm to -2000 nm with respect to the measurement surface (reference surface) using frequency domain analysis (calculation software; MetroPro), and the corresponding location is determined as a black area. A two-dimensional image was obtained.
Note that the measurement plane (reference plane) was set based on the plane that was the average height within the measurement visual field area. Table 2 shows the area of the black area (B-BA) in the two-dimensional image.
Next, the two-dimensional image was binarized and analyzed using −100 nm as a threshold value with respect to the measurement surface, to obtain a binarized image in which the portion below −100 nm was a white region. Table 2 shows the area (A-WA) of the white region in the binarized image.
Next, the ratio of the sum of the area of the black area in the two-dimensional image (B-BA) and the area of the white area in the binarized image (A-WA) to the measurement field area S of the white interferometer was calculated (as described above). (See formulas (1) to (3).) The results are shown in Table 2.

(2) Measurement of the maximum valley depth and arithmetic mean height of the surface of the adhesive layer Among the two-dimensional images obtained from the above-mentioned white interferometer measurement, the maximum valley depth is determined by the minimum value with respect to the average plane within the measurement field of view area. It was set as (Sv). Further, the value of Ra was defined as the arithmetic mean height (Sa). Note that the maximum valley depth and arithmetic mean height were determined by averaging data from three randomly selected points. The results are shown in Table 2.

(3) Measurement of maximum peak height and arithmetic mean height of release liner In (1) above, the release liner that has been peeled off from the adhesive layer is set in the above white interferometer, and the interference data of the release liner is measured under the above conditions. Measurements were taken to obtain two-dimensional images. Among the obtained two-dimensional images, the maximum value with respect to the average plane within the measurement visual field area was defined as the maximum peak height (Sp). Further, the value of Ra was defined as the arithmetic mean height (Sa). In addition, the maximum peak height and the arithmetic mean height were determined by averaging data from three randomly selected points. The results are shown in Table 1.

(4) Determination of the number of defects by microscopic observation of the substrate The surface of the substrate was observed with a microscope (manufactured by OLYMPUS, trade name BX51, eyepiece magnification 10×, objective lens magnification 10×). 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 diameter of 10 μm or more was visually measured.
The results are shown in Table 1.

(5) Measurement of tear strength of base material Measurement was basically based on JIS K7128-1:1998.
Specifically, the base material was cut into a size of 150 mm x 50 mm. Next, a 75 mm slit was made from the center of the short side end in a direction parallel to the long side to prepare a sample piece. The sample was prepared so that the tear strength in the MD direction was such that the long side direction was parallel to the MD direction, and the tear strength in the TD direction was such that the long side direction was parallel to the TD direction.
The obtained test piece was attached to a tensile testing machine and evaluated at a tensile rate of 200 mm/min (in an atmosphere of 23° C./50% relative humidity) to measure the tear force. Tear strength f was calculated from the obtained tear force. (f=Ft/d (Ft: tear force of test piece [N], d: thickness of test piece [mm])) The results are shown in Table 1.

[Peeling force evaluation: triggered peeling force]
Regarding the surface protection films A and B, the 90° and 180° trigger peel forces against the surface-treated layer side surface of the protective member produced in Production Example 5, which will be described later, were measured. Further, for the surface protection film C, the 90° and 180° trigger peel forces against the substrate side surface of the surface protection film A or B were measured. The measurement was performed with N=10, and the average value was taken as the trigger peeling force. The results are shown in Table 3. The method for measuring the triggered peel force is as follows.
<Measurement method of triggered peel force>
(1) Surface protection films A and B
The protective member was cut into a rectangular film piece (50 mm x 50 mm) and bonded to a SUS board via double-sided adhesive tape (manufactured by Nitto Denko Corporation, "No. 535A"). At this time, the acrylic film side was attached to the SUS plate side. Next, the surface protection film A or B cut out in the same shape is laminated and laminated on the surface treated layer surface of the protection member using one reciprocation of a hand roller, thereby forming the structure of [SUS board/protection member/surface protection film]. A laminate having the following properties was obtained. Place an adhesive tape (manufactured by Nitto Denko Corporation, "No. 315", width 25 mm) cut to a length of about 10 cm at a point 2 cm from the corner of the surface protection film of the laminate, and paste together with one round trip with a 2 kg roller. A measurement sample was obtained.
Regarding the above measurement sample, the peeling force when peeling the surface protection film from the corner of the measurement sample was measured under the following conditions, and the peak value immediately after the start of the measurement was taken as the trigger peeling force of the surface protection film A or B.
・Measuring device: Tensile tester (manufactured by Kyowa Interface Science Co., Ltd., adhesive film peeling analyzer "VPA-2", turn on the power and let it age for at least 30 minutes.)
・Measurement environment: 23±5℃, 60±20RH%
・Peeling speed: 300mm/min ・Peeling angle: 90° or 180°
(2) Surface protection film C
Cut out the surface protection film A or B into a rectangular film piece (50 mm x 50 mm), peel off the release liner and attach it to the SUS board via the exposed adhesive layer, and apply it to the surface of the base layer of the surface protection film. The trigger peeling force of the protective film C was measured in the same manner as in (1) above, except that the surface protective film C was attached.

[Peeling force evaluation: Normal peeling force]
Regarding the surface protection films A and B, the normal peeling force against the surface of the surface treatment layer side of the protective member of the optical laminate produced in Example 1, which will be described later, was measured. Furthermore, the normal peeling force of surface protection film C against the substrate side surface of surface protection film A or B was measured. The measurement was performed with N=30, and the average value was taken as the normal peeling force. The results are shown in Table 4. Note that the peeling force is usually measured as follows.
<Normal peeling force measurement method>
The surface protection film was cut into a size of 25 mm in width and 100 mm in length, the release liner was peeled off from the adhesive layer, and the film 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 allowed to stand for 30 minutes in an environment with a temperature of 23°C and a relative humidity of 50%, and then a peel test was conducted under the same environment at a peel angle of 180° and a tensile speed of 300 mm/min, and the 180° peel force was measured. .

[Production Example 2: Production of polarizing film]
A long roll of polyvinyl alcohol (PVA) resin film (manufactured by Kuraray Co., Ltd., product name "PE3000") with a thickness of 30 μm was uniaxially stretched in the longitudinal direction so as to be 5.9 times the length in the longitudinal direction using a roll stretching machine. At the same time, swelling, dyeing, crosslinking, and washing treatments were performed, and finally a drying treatment was performed to prepare an absorption type polarizing film with a thickness of 12 μm.
Specifically, in the swelling treatment, the film was stretched 2.2 times while being treated with pure water at 20°C. Next, the dyeing process was carried out in an aqueous solution at 30°C in which the weight ratio of iodine and potassium iodide was 1:7, and the iodine concentration was adjusted so that the single transmittance of the obtained absorption type polarizing film was 45.0%. It was stretched 1.4 times during processing. Furthermore, a two-stage crosslinking process was adopted for the crosslinking process, and the first crosslinking process was performed in an aqueous solution containing boric acid and potassium iodide at 40°C, and was stretched to 1.2 times. The boric acid content of the aqueous solution for the first stage crosslinking treatment was 5.0% by weight, and the potassium iodide content was 3.0% by weight. In the second stage of crosslinking treatment, the film was stretched to 1.6 times while being treated in an aqueous solution containing boric acid and potassium iodide at 65°C. The boric acid content of the aqueous solution for the second stage crosslinking treatment was 4.3% by weight, and the potassium iodide content was 5.0% by weight. Further, the cleaning treatment was performed using a potassium iodide aqueous solution at 20°C. The potassium iodide content of the aqueous solution for cleaning treatment was 2.6% by weight. Finally, the drying process was carried out at 70° C. for 5 minutes to obtain an absorption type polarizing film.
A triacetyl cellulose (TAC) resin film with HC (TAC thickness: 25 μm, HC thickness: 7 μm) was placed on one side of the obtained absorption type polarizing film, and a cycloolefin resin film (thickness: 13 μm) was placed on the other side. were laminated together as a protective layer. Specifically, the curable adhesive was coated to a total thickness of about 1 μm, and then bonded together using a roll machine. Thereafter, UV light was irradiated from the TAC film side to cure the adhesive.
Thereby, a polarizing film having the structure of [TAC film (protective layer)/absorption type polarizing film/COP film (protective layer)] was obtained.

[Manufacturing Example 3: Fabrication of λ/4 member]
Polymerization was carried out using a batch polymerization apparatus consisting of two vertical reactors equipped with a stirring blade and a reflux condenser controlled at 100°C. Bis[9-(2-phenoxycarbonylethyl)fluoren-9-yl]methane 29.60 parts by mass (0.046 mol), isosorbide (ISB) 29.21 parts by mass (0.200 mol), spiroglycol (SPG) 42 .28 parts by mass (0.139 mol), 63.77 parts by mass (0.298 mol) of diphenyl carbonate (DPC), and 1.19×10 ⁻² parts by mass (6.78×10 −2 of calcium acetate monohydrate as a catalyst ^{). 5} mol) was prepared. After the inside of the reactor was replaced with nitrogen under reduced pressure, it was heated with a heating medium, and when the internal temperature reached 100°C, stirring was started. 40 minutes after the start of temperature rise, the internal temperature was controlled to reach 220°C, and at the same time, pressure reduction was started to maintain this temperature, and the pressure was reduced to 13.3 kPa in 90 minutes after reaching 220°C. Phenol vapor produced as a by-product during the polymerization reaction was led to a reflux condenser at 100°C, a small amount of monomer component contained in the phenol vapor was returned to the reactor, and uncondensed phenol vapor was led to a condenser at 45°C for recovery. After nitrogen was introduced into the first reactor and the pressure was once restored to atmospheric pressure, the oligomerized reaction liquid in the first reactor was transferred to the second reactor. Next, temperature increase and pressure reduction in the second reactor were started, and the internal temperature was 240° C. and the pressure was 0.2 kPa in 50 minutes. Thereafter, polymerization was allowed to proceed until a predetermined stirring power was reached. When a predetermined power was reached, nitrogen was introduced into the reactor to restore the pressure, the produced polyester carbonate resin was extruded into water, and the strands were cut to obtain pellets.

After vacuum drying the obtained polyester carbonate resin (pellets) at 80°C for 5 hours, a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder temperature setting: 250°C) and a T-die (width 200mm, setting temperature: 250°C) were used. A long resin film with a thickness of 135 μm was produced using a film forming apparatus equipped with a chill roll (set temperature: 120 to 130° C.), a winder and a winder. The obtained elongated resin film was stretched in the width direction at a stretching temperature of 143° C. and a stretching ratio of 2.8 times to obtain a stretched film (λ/4 member) with a thickness of 47 μm. The obtained stretched film had Re(550) of 143 nm, Re(450)/Re(550) of 0.86, and Nz coefficient of 1.12.

[Manufacture example 4: Preparation of positive C plate]
20 parts by weight of a side chain type liquid crystal polymer represented by the following chemical formula (1) (numbers 65 and 35 in the formula indicate mol% of monomer units, 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 (manufactured by BASF, trade name Paliocolor LC242) and 5 parts by weight of a photopolymerization initiator (manufactured by Ciba Specialty Chemicals, trade name Irgacure 907) were dissolved in 200 parts by weight of cyclopentanone. A liquid crystal coating solution was prepared. Then, the coating solution was applied to a PET substrate subjected to vertical alignment treatment using a bar coater, and then heated and dried at 80° C. for 4 minutes to align the liquid crystal. By irradiating this liquid crystal layer with ultraviolet rays and curing the liquid crystal layer, a positive C plate having a thickness of 4 μm and an Rth (550) of −100 nm was formed on the base material.

[Production Example 5: Production of protective member]
A hard coat layer forming material shown below was applied to an acrylic film (40 μm thick) having a lactone ring structure, and the applied layer was dried to form a 0.5 μm thick hard coat layer. Next, the antireflection layer forming material shown below was applied to the surface of the hard coat layer, heated at 80°C for 1 minute, and the heated coating layer was irradiated with ultraviolet rays at a cumulative light intensity of 300 mJ/cm ² using a high-pressure mercury lamp. The coating layer was cured to form an antireflection layer with a thickness of 0.1 μm. Thereby, a protective member having the structure of [acrylic film/hard coat layer/antireflection layer] was obtained.

(Material for forming hard coat layer)
By adding 0.5% by weight of a leveling agent to acrylic resin raw material (manufactured by Dainippon Ink Co., Ltd., product name: GRANDIC PC1071), and further diluting with ethyl acetate so that the solid content concentration is 50% by weight, A material for forming a hard coat layer was prepared. The leveling agent is a copolymer copolymerized at a molar ratio of dimethylsiloxane: hydroxypropylsiloxane: 6-isocyanatehexylisocyanuric acid: aliphatic polyester = 6.3:1.0:2.2:1.0. It is.

(Anti-reflection layer forming material)
100 parts by weight of polyfunctional acrylate whose main component is pentaerythritol triacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., product name "Viscoat #300", solid content 100% by weight), hollow nano silica particles (JGC Catalysts & Chemicals Co., Ltd.) 150 parts by weight, solid nano silica particles (manufactured by Nissan Chemical Industries, Ltd., trade name "MEK-2140Z-AC", solid content 20% by weight, weight average particle diameter 75 nm), solid content 30% 50 parts by weight (wt%, weight average particle diameter 10 nm), 12 parts by weight of a fluorine element-containing additive (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KY-1203", solid content 20 wt%), and a photopolymerization initiator ( 3 parts by weight of "OMNIRAD907" (trade name, manufactured by BASF, solid content: 100% by weight) were mixed. To the mixture, a mixed solvent of TBA (tertiary butyl alcohol), MIBK (methyl isobutyl ketone) and PMA (propylene glycol monomethyl ether acetate) mixed in a weight ratio of 60:25:15 was added as a diluting solvent to dissolve the entire solid. The content was adjusted to 4% by weight and stirred to prepare an antireflection layer forming material.

[Production Example 6: Preparation of adhesive layer]
In a four-neck flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser, add 80.3 parts of butyl acrylate, 16 parts of phenoxyethyl acrylate, 3 parts of N-vinyl-2-pyrrolidone (NVP), and acrylic acid. A monomer mixture containing 0.3 parts and 0.4 parts of 4-hydroxybutyl acrylate was charged. Further, to 100 parts of the above monomer mixture (solid content), 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator was charged together with 100 parts of ethyl acetate, and nitrogen gas was added while stirring gently. The atmosphere was replaced with nitrogen. Next, a polymerization reaction was carried out for 8 hours while maintaining the liquid temperature in the flask at around 55° C. to prepare an acrylic polymer solution. The weight average molecular weight of the acrylic polymer was 1.5 million. An acrylic adhesive solution was prepared by adding 0.3 parts of benzoyl peroxide (BPO: Niper BMT manufactured by NOF Corporation) as a crosslinking agent to 100 parts of the solid content of the obtained acrylic polymer solution.
The obtained adhesive composition was applied to the release-treated layer surface of a release liner (manufactured by Toray Industries, Inc., Therapel) and dried at 155° C. for 3 minutes to form an adhesive layer with a thickness of 20 μm.

[Example 1]
(1) A surface protection film laminate was obtained using surface protection film A as the first surface protection film and surface protection film C as the second surface protection film. Specifically, a release liner is peeled off from surface protection film C and bonded to the base material surface of surface protection film A to form a surface protection film having the configuration of [release liner/surface protection film A/surface protection film C]. A laminate was obtained.
(2) The adhesive layer obtained in Production Example 6 was laminated together with a release liner on the COP protective layer side surface of the polarizing film obtained in Production Example 2 to obtain a polarizing film with an adhesive layer.
(3) The positive C plate was transferred to a λ/4 member (stretched film) via an ultraviolet curable adhesive (thickness after curing: 1 μm) to obtain a retardation member. The protective member obtained in Production Example 5 was bonded to the positive C plate side of the obtained retardation member via another acrylic adhesive layer. At this time, they were bonded together so that the acrylic film of the protective member was located on the retardation member side (in other words, so that the antireflection layer was on the outermost surface). Next, another acrylic adhesive layer formed on the release liner was attached to the λ/4 member side surface. Thereby, a laminate having the structure of [protective member/positive C plate/λ/4 member/acrylic adhesive layer/release liner] was obtained.
(4) Apply the surface protection film laminate obtained in (1) 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. Combined. Immediately after bonding, rectangular film A was punched out by inserting a blade from above. Note that the rectangular film A is punched out with a blade such that the slow axis of the λ/4 member is parallel to the transverse direction. Similarly, a rectangular film B was punched out by inserting a blade into the adhesive layer-attached polarizing film obtained in (2) from above. Note that the rectangular film B is punched out with a blade so that the absorption axis of the absorption type polarizing film is inclined at 45 degrees with respect to the longitudinal direction. The release liner of Film A was peeled off and the film was bonded to Film B with the longitudinal direction aligned without applying tension. As mentioned above, film A is punched so that the slow axis of the λ/4 member is parallel to the transverse direction, and film B is punched so that the absorption axis of the absorption type polarizing film is diagonally 45 degrees. The angle between the absorption axis of the absorption type polarizing film and the slow axis of the λ/4 member is 45°.
As described above, the surface protection having the structure of [optical laminate (release liner/adhesive layer/polarizing member/λ/4 member/positive C plate/protective member)/surface protection film A/surface protection film C] An optical laminate with film was obtained.

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

[Comparative example 1]
[Optical laminate/ An optical laminate with a surface protection film having the structure of [Surface Protection Film C] was obtained.

[Comparative example 2]
[Optical laminate/ An optical laminate with a surface protection film having the structure of [Surface Protection Film A] was obtained.

[Comparative example 3]
[Optical laminate/ An optical laminate with a surface protection film having the structure of [Surface Protection Film B] was obtained.

[Defect inspection]
The optical laminates with surface protection films obtained in the above Examples and Comparative Examples were cut into a size of 371.87 mm x 236.58 mm and used as samples to be tested. The samples to be inspected in Examples 1 and 2 were subjected to defect inspection with the release liner and second surface protection film removed, and the samples to be inspected in Comparative Examples 1 to 3 were subjected to defect inspection with the release liner removed. Specifically, the sample to be inspected was set in the chucking part of an automatic optical visual inspection device, and defects (scratches, foreign objects, air bubbles, etc.) with a size of 100 μm or more in the sample were detected. Next, by observing with a microscope the locations where defects with a size of 100 μm or more were detected, it was confirmed whether the defects were erroneously detected due to the surface protection film or defects in the optical laminate. The inspection failure rate was calculated based on the formula: Inspection failure rate (%) = number of false positives/total number of detections x 100, and the effectiveness of the test was evaluated based on the following criteria. In addition, the presence or absence of scratches with a size of 100 μm or more on the surface of the surface protection film was checked, and scratch evaluation was performed based on the following criteria. The results are shown in Table 5.
<Evaluation of effectiveness of inspection>
〇 (Good): Inspection defect rate: 0%
△ (Acceptable): Inspection failure rate: More than 0% and less than 10% × (Poor): Inspection failure rate 10% or more <Flaw evaluation>
〇 (Good): No scratches of 100 μm or more × (Bad): Scratches of 100 μm or more

As shown in Table 5, the optical laminate with a surface protection film of the example, which has a structure in which the surface protection film is double affixed to the surface of the optical laminate, is Scratches are prevented. In addition, even if the outer surface protection film is peeled off and removed during defect inspection, the optical laminate can be inspected for defects with the inner surface protection film attached, and the surface remains unchanged until it is used for assembly. can be protected. Furthermore, by using a film with a small haze as the inner surface protection film, the optical laminate can be suitably inspected automatically with the surface protection film attached.

The present invention is not limited to the above embodiments, and various modifications are possible. For example, it can be replaced with a configuration that is substantially the same as the configuration shown in the above embodiment, a configuration that has the same effect, or a configuration that can achieve the same objective.

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

2 Display system 4 Lens section 10 Polarizing member 12 Display element 14 Reflective polarizing member 16 First lens section 18 Half mirror 20 First retardation member 22 Second retardation member 24 Second lens section 100 Optical laminate 110 First surface Protective film 120 Second surface protection film 200 Optical laminate with surface protection film

Claims

An optical laminate including at least one optical member and used for goggles with a display;
a first surface protection film and a second surface protection film that are attached to one surface of the optical laminate in this order outward;
An optical laminate with a surface protection film.
The optical laminate with a surface protection film according to claim 1, wherein the first surface protection film has a haze of less than 5%.
As the first surface protection film,
comprising a first base material and a first adhesive layer laminated on the first base material,
The absolute value of the maximum valley depth (Sv) of the surface of the first adhesive layer opposite to the first base material is 500 nm or less,
A surface protection film is attached to the optical laminate, in which the number of defects with a maximum Feret diameter of 10 μm or more is less than 3 in an observation area of 100 μm x 100 μm when the first base material is observed under a microscope. An optical laminate with a surface protection film according to claim 1 obtained.
The optical laminate with a surface protection film according to claim 3, wherein the absolute value of the arithmetic mean height (Sa) of the surface of the first adhesive layer opposite to the first base material is 25 nm or less.
As the first surface protection film,
comprising a first base material and a first adhesive layer laminated on the first base material,
According to claim 1, the surface of the first adhesive layer opposite to the first base material is obtained by attaching a surface protection film to the optical laminate that satisfies the following formula (1). Optical laminate with surface protection film;

(In formula (1), S represents the measurement field area of the white interferometer in the following surface shape evaluation test; B-BA is the area of the black area in the two-dimensional image before binarization obtained in the following surface shape evaluation test. (A-WA indicates the area of the white region in the two-dimensional image after binarization obtained in the surface shape evaluation test below.)
<Surface shape evaluation test>
measuring the surface of the first adhesive layer opposite to the first base material using a white interferometer;
After calculating the obtained interference data by frequency domain analysis in the analysis range of -1000 nm to -2000 nm with respect to the measurement surface to obtain a two-dimensional image in which the corresponding location becomes a black area;
The two-dimensional image is binarized and analyzed using −100 nm as a threshold value with respect to the measurement surface to obtain a binarized image in which the portion below −100 nm is a white region.
The optical laminate with a surface protection film according to claim 5, wherein when the first base material is observed under a microscope, the number of defects with a maximum Feret diameter of 10 μm or more is less than 3 in an observation area of 100 μm x 100 μm.
The optical laminate with a surface protection film according to claim 1, wherein the optical laminate includes a polarizing member, a first retardation member, and a protection member in this order toward the first surface protection film.
The protective member includes a surface treatment layer,
The optical laminate with a surface protection film according to claim 7, wherein the first surface protection film is attached to the surface treatment layer.
The optical laminate with a surface protection film according to claim 1, wherein the optical laminate has an adhesive layer on a surface opposite to the side to which the first surface protection film and the second surface protection film are attached. body.
A method for producing an optical laminate with a surface protection film, the method comprising:
Affixing a first surface protection film and a second surface protection film to one surface of an optical laminate having at least one optical member,
A manufacturing method, wherein the first surface protection film is selected from (i) and (ii);
(i) having a first base material and a first adhesive layer laminated on the first base material,
The absolute value of the maximum valley depth (Sv) of the surface of the first adhesive layer opposite to the first base material is 500 nm or less,
A surface protection film having less than three defects with a maximum Feret diameter of 10 μm or more in an observation area of 100 μm x 100 μm when the first base material is observed under a microscope;
(ii) having a first base material and a first adhesive layer laminated on the first base material,
The surface of the first adhesive layer opposite to the first base material is a surface protection film that satisfies the following formula (1);

(In formula (1), S represents the measurement field area of the white interferometer in the following surface shape evaluation test; B-BA is the area of the black area in the two-dimensional image before binarization obtained in the following surface shape evaluation test. (A-WA indicates the area of the white region in the two-dimensional image after binarization obtained in the surface shape evaluation test below.)
<Surface shape evaluation test>
measuring the surface of the first adhesive layer opposite to the first base material using a white interferometer;
After calculating the obtained interference data by frequency domain analysis in the analysis range of -1000 nm to -2000 nm with respect to the measurement surface to obtain a two-dimensional image in which the corresponding location becomes a black area;
The two-dimensional image is binarized and analyzed using −100 nm as a threshold value with respect to the measurement surface to obtain a binarized image in which the portion below −100 nm is a white region.
A method of manufacturing a display system, the method comprising:
Another member is pasted on the side opposite to the side to which the first surface protection film and the second surface protection film of the optical laminate with a surface protection film according to any one of claims 1 to 9 are pasted. to obtain a secondary laminate with a surface protection film,
Peeling the second surface protection film from the surface protection film-attached secondary laminate;
inspecting the secondary laminate with the surface protection film for defects; and peeling off the first surface protection film from the secondary laminate with the surface protection film to obtain a secondary laminate.
In this order,
A manufacturing method, wherein the display system is goggles with a display.