WO2023234100A1

WO2023234100A1 - Polarizing plate with retardation layer and image display device

Info

Publication number: WO2023234100A1
Application number: PCT/JP2023/018935
Authority: WO
Inventors: 雅人藤田
Original assignee: 日東電工株式会社
Priority date: 2022-05-31
Filing date: 2023-05-22
Publication date: 2023-12-07
Also published as: TW202411695A

Abstract

The present invention provides a polarizing plate with a retardation layer, the polarizing plate being capable of contributing to the improvement of durability of an image display device in a high-temperature high-humidity environment. A polarizing plate with a retardation layer according to the present invention sequentially comprises, in the following order: a polarizing plate that has a first main surface and a second main surface, which are opposite to each other, while comprising a polarizer from the first main surface toward the second main surface; a first adhesive layer; a first retardation layer; a bonding agent layer; a second retardation layer; and a second adhesive layer. This polarizing plate with a retardation layer also comprises an adhesive layer that contains an antistatic agent. With respect to this polarizing plate with a retardation layer, the tensile elastic modulus at 110°C of an adjacent layer that is adjacent to the second main surface side of the first retardation layer is 1 MPa or more; the addition amount of the antistatic agent in the adhesive layer that contains the antistatic agent is 5 phr or less; and if this polarizing plate with a retardation layer is bonded to a multilayer body, which comprises a polyethylene terephthalate resin film having a thickness of 50 µm and an aluminum layer that is provided on one surface of the polyethylene terephthalate resin film and has a thickness of 0.05 µm, in such a manner that the second adhesive layer is bonded to the surface of the aluminum layer, the resistivity change of the aluminum layer after being maintained in the bonded state at 110°C and 85% RH for 36 hours is 2 or less.

Description

Polarizing plate with retardation layer and image display device

The present invention relates to a polarizing plate with a retardation layer and an image display device.

In recent years, image display devices typified by liquid crystal display devices and electroluminescence (EL) display devices (eg, organic EL display devices, inorganic EL display devices) have rapidly become popular. In general, a polarizing plate with a retardation layer that integrates a polarizing plate and a retardation layer is widely used in these image display devices for the purpose of optical compensation, prevention of external light reflection, etc. (Patent Document 1, etc.) ). For example, in an organic EL display device, a polarizing plate with a retardation layer (circularly polarizing plate) is disposed on the viewing side of the organic EL panel to prevent reflection of external light by electrodes provided on the panel.

In addition, in a polarizing plate with a retardation layer disposed on the viewing side of an image display panel such as an organic EL panel or a liquid crystal panel, by incorporating an antistatic agent into at least one of the constituent members, it is possible to prevent images caused by charging. Efforts are being made to prevent defects in display devices.

On the other hand, with the diversification of usage environments, image display devices are required to have improved durability under high temperature and high humidity environments.

Japanese Patent Application Publication No. 2022-013705

The inventors investigated the durability of image display devices under high temperature and high humidity environments, and found that under high temperature and high humidity conditions, cracks occur in the retardation layer and iodine contained in the polarizer reaches the image display panel. It has been found that the antistatic agent may leak out or the antistatic agent may leak onto the image display panel, which can cause corrosion to the electrodes provided on the image display panel. In addition, as the retardation layer, a retardation film composed of a stretched resin film or a retardation film composed of an alignment solidified layer of a liquid crystal compound is mainly used, but such problems arise due to the reflection properties. It was also found that this phenomenon tends to occur more easily when using a retardation film composed of a stretched film of a resin film with better quality, and less likely to occur when using a retardation film composed of an alignment solidified layer of a liquid crystal compound. .

The present invention has been made based on the above findings, and its main purpose is to provide a polarizing plate with a retardation layer that can contribute to improving the durability of image display devices under high temperature and high humidity conditions.

According to embodiments of the present invention, the following polarizing plates with retardation layers or image display devices are provided: [1] to [10].
[1] Having a first main surface and a second main surface facing each other, from the first main surface toward the second main surface, a polarizing plate including a polarizer, a first adhesive layer, and a first adhesive layer. A polarizing plate with a retardation layer, which includes a first retardation layer, an adhesive layer, a second retardation layer, and a second adhesive layer in this order, and includes an adhesive layer containing an antistatic agent. , the tensile modulus at 110° C. of the adjacent layer adjacent to the second main surface side of the first retardation layer is 1 MPa or more, and the amount of the antistatic agent added in the adhesive layer containing the antistatic agent. is 5 phr or less, and the polarizing plate with a retardation layer is placed on the surface of the aluminum layer of a laminate including a polyethylene terephthalate resin film with a thickness of 50 μm and an aluminum layer with a thickness of 0.05 μm provided on one surface thereof. A polarizing plate with a retardation layer, wherein the aluminum layer has a resistivity change of 2 or less after being held for 36 hours at 110° C. and 85% RH in a state where the aluminum layer is bonded via the second adhesive layer.
[2] The first retardation layer is a stretched resin film, Re (550) of the first retardation layer is 100 nm to 190 nm, and Re (450)/Re (550) is 0. .8 or more and less than 1, and the angle between the slow axis of the first retardation layer and the absorption axis of the polarizer is 40° to 50°, the polarized light with a retardation layer according to [1]. Board.
[3] The polarizing plate with a retardation layer according to [1] or [2], wherein the first retardation layer has a thickness of 10 μm or more.
[4] The polarizing plate with a retardation layer according to [2], wherein the second retardation layer exhibits a refractive index characteristic of nz>nx=ny.
[5] The retardation layer according to any one of [1] to [4], wherein the first adhesive layer and/or the second adhesive layer has a surface resistivity of 9×10 ¹¹ Ω/□ or less. With polarizing plate.
[6] The retardation according to any one of [1] to [5], wherein the antistatic agent contains an ionic compound containing bistrifluoromethanesulfonylimide (N(SO ₂ CF ₃ ) ₂ ⁻ ) as an anion. Layered polarizing plate.
[7] The polarizing plate with a retardation layer according to any one of [1] to [6], wherein the adjacent layer is the adhesive layer.
[8] The retardation layer according to any one of [1] to [6], wherein the adjacent layer is a hard coat layer formed directly on the second main surface side surface of the first retardation layer. Polarizer.
[9] An image display device comprising an image display panel and the polarizing plate with a retardation layer according to any one of [1] to [8] arranged on the viewing side of the image display panel.
[10] The image display device according to [9], wherein the image display panel includes an electrode, and the change in resistivity of the electrode after being maintained at 110° C. and 85% RH for 36 hours is 2 or less.

According to the embodiment of the present invention, by providing a high elasticity layer adjacent to the first retardation layer, thermal contraction of the first retardation layer and generation of cracks caused by the thermal contraction are suppressed, and charging The amount of the inhibitor added is within a range that provides a practically sufficient antistatic function without significantly plasticizing the adhesive layer. As a result, it is possible to suppress the outflow of iodine or antistatic agent to the image display panel, and prevent problems caused by these, and as a result, the durability of the image display device under high temperature and high humidity can be improved. I can do it.

FIG. 1 is a schematic cross-sectional view of a polarizing plate with a retardation layer in one embodiment of the present invention. FIG. 1 is a schematic cross-sectional view of a polarizing plate with a retardation layer in one embodiment of the present invention. FIG. 2 is a schematic diagram illustrating how a polarizing plate with a retardation layer is used in one embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. In order to 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 only an example and does not limit the interpretation of the present invention. isn't it. Moreover, in this specification, (meth)acrylic refers to acrylic and/or methacryl.

(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 and 45° counterclockwise.

A. Polarizing Plate with Retardation Layer A polarizing plate with a retardation layer according to an embodiment of the present invention has a first main surface and a second main surface facing each other, and extends from the first main surface to the second main surface. , a polarizing plate including a polarizer, a first adhesive layer, a first retardation layer, an adhesive layer, a second retardation layer, and a second adhesive layer, in this order, and the first The tensile modulus at 110° C. of the adjacent layer adjacent to the second main surface side of the retardation layer is 1 MPa or more, and the adhesive layer includes an antistatic agent, and the adhesive layer includes the antistatic agent. The amount of the antistatic agent added is 5 phr or less. In the present invention, the adjacent layer adjacent to the second main surface side of the first retardation layer is a layer adjacent to the first retardation layer so as to be in direct contact with the first retardation layer.

A polarizing plate with a retardation layer according to an embodiment of the present invention has a second adhesive on the surface of the aluminum layer of a laminate including a PET resin film with a thickness of 50 μm and an aluminum layer with a thickness of 0.05 μm provided on one surface of the PET resin film. The change in resistivity of the aluminum layer (resistivity after holding/resistivity before holding) after holding for 36 hours at 110°C and 85% RH in a state where the aluminum layer is laminated via a chemical layer is typically It is 2 or less, preferably 1.8 or less, more preferably 1.5 or less, and still more preferably 1.2 or less. The change in resistivity of the aluminum layer can be determined by the method described in Examples.

A-1. Overall Configuration of Polarizing Plate with Retardation Layer FIG. 1 is a schematic cross-sectional view of a polarizing plate with a retardation layer according to one embodiment of the present invention. The polarizing plate 100A with a retardation layer has a first main surface 100a and a second main surface 100b, and the polarizing plate 10 and the first adhesive layer are arranged from the first main surface 100a toward the second main surface 100b. 20, a first retardation layer 30, an adhesive layer 40, a second retardation layer 50, and a second adhesive layer 60 in this order. The polarizing plate 10 includes a polarizer 12, a first protective layer 14a disposed on the opposite side of the polarizer 12 to the side on which the first retardation layer 30 is disposed, and a side on which the first retardation layer 30 is disposed. and a second protective layer 14b disposed on the second protective layer 14b. The polarizing plate 10 and the first retardation layer 30 are bonded together via the first adhesive layer 20. Further, the first retardation layer 30 and the second retardation layer 50 are bonded together with an adhesive layer 40 interposed therebetween. In this embodiment, the adjacent layer adjacent to the second main surface 100b side of the first retardation layer 30 is the adhesive layer 40.

FIG. 2 is a schematic cross-sectional view of a polarizing plate with a retardation layer according to one embodiment of the present invention. The polarizing plate 100B with a retardation layer has a first main surface 100a and a second main surface 100b, and the polarizing plate 10 and the first adhesive layer are arranged from the first main surface 100a toward the second main surface 100b. 20, a first retardation layer 30, a hard coat layer 70, an adhesive layer 40, a second retardation layer 50, and a second adhesive layer 60 in this order. The polarizing plate 10 includes a polarizer 12, a first protective layer 14a disposed on the opposite side of the polarizer 12 to the side on which the first retardation layer 30 is disposed, and a side on which the first retardation layer 30 is disposed. and a second protective layer 14b disposed on the second protective layer 14b. The polarizing plate 10 and the first retardation layer 30 are bonded together via the first adhesive layer 20. Further, the hard coat layer 70 is directly formed on the second main surface 100b side surface of the first retardation layer 30, and the second retardation layer 50 is formed on the second main surface side via the adhesive layer 40. It is pasted together. In this embodiment, the adjacent layer adjacent to the second main surface 100b side of the first retardation layer 30 is the hard coat layer 70.

A polarizing plate with a retardation layer according to an embodiment of the present invention includes an adhesive layer containing an antistatic agent. Typically, at least one selected from the first adhesive layer and the second adhesive layer contains an antistatic agent. For example, in an organic EL display device incorporating a touch panel, unintended light emission may occur when a finger touches the display portion. The light emission is mainly caused by electrostatic charging caused by contact. Furthermore, in a liquid crystal display device, static electricity may induce poor alignment of liquid crystal compounds. On the other hand, by using an adhesive layer containing an antistatic agent, it is possible to prevent such adverse effects of static electricity on the image display device. When the second adhesive layer present near the image display panel contains an antistatic agent, it is possible to suitably prevent such adverse effects of static electricity on the image display device. On the other hand, when the first adhesive layer located far from the image display panel contains an antistatic agent, in addition to preventing such adverse effects, it also suppresses corrosion of the touch sensor electrode such as the aluminum layer caused by the antistatic agent. It can be advantageous in that it can be done.

In the polarizing plate with a retardation layer according to the embodiment of the present invention, the surface resistivity of the surface on the second adhesive layer side is preferably 9.0×10 ¹¹ Ω/□ or less, more preferably 1.0×10 ⁸ Ω. /□ to 8.0× ^{10 11} Ω/□, more preferably 5.0×10 ⁸ Ω/□ to 6.0×10 ¹¹ Ω/□.

The configuration of the polarizing plate with a retardation layer according to the embodiment of the present invention is not limited to the illustrated example. Specifically, one of the first protective layer 14a and the second protective layer 14b, for example, the second protective layer 14b, may be omitted depending on the purpose. Further, a release liner (not shown) may be temporarily attached to the second adhesive layer 60 side surface of the

polarizing plates

100A and 100B with retardation layers. The release liner can protect the second adhesive layer 60 until the retardation layer-attached

polarizing plate

100A, 100B is used. Practically, as shown in FIG. 3, in the polarizing plate 100 with a retardation layer, the second principal surface 100b side is the viewing side of the image display panel 200 such as an organic EL panel or a liquid crystal panel with the second adhesive layer interposed therebetween. is attached to constitute the image display device 300. The image display panel 200 typically includes, on its surface and/or inside, an electrode for driving a display element or for a touch sensor (such as a conductive layer including a laminated structure of an Al layer and a Ti layer).

The polarizing plate with a retardation layer may be elongated or sheet-like. Here, "elongated shape" refers to an elongated shape whose length is sufficiently longer than its width, for example, an elongated shape whose length is 10 times or more, preferably 20 times or more as compared to its width. The elongated polarizing plate with a retardation layer can be wound into a roll.

The thickness of the polarizing plate with a retardation layer excluding the second adhesive layer (thickness from the polarizing plate to the second retardation layer) is, for example, 50 μm to 120 μm, preferably 70 μm to 100 μm, and more preferably 80 μm to 90 μm.

A-2. Polarizing Plate The polarizing plate 10 typically includes a polarizer and a protective layer disposed on one or both sides of the polarizer. Preferably, the polarizing plate 10 includes a polarizer 12 and a first protective layer 14a disposed on a side of the polarizer 12 opposite to the side on which the first retardation layer 30 is disposed. The second protective layer 14b disposed on the first retardation layer 30 side of the polarizer 12 may be omitted depending on the purpose. In one embodiment, the polarizer and the protective layer are bonded together via an adhesive layer (typically, an adhesive layer). For example, the polarizer and the protective layer are bonded together using an active energy ray-curable adhesive. In another embodiment, the polarizer and the protective layer are laminated in close contact with each other without using an adhesive layer.

A-2-1. Polarizer A polarizer is typically a resin film containing a dichroic substance (eg, iodine). Examples of the resin film include hydrophilic polymer films such as polyvinyl alcohol (PVA) films, partially formalized PVA films, and partially saponified ethylene/vinyl acetate copolymer films.

The thickness of the polarizer is preferably 18 μm or less, more preferably 15 μm or less, and even more preferably 12 μm or less. On the other hand, the thickness of the polarizer is preferably 1 μm or more.

The polarizer preferably exhibits absorption dichroism at a wavelength of 380 nm to 780 nm. The single transmittance of the polarizer is, for example, 41.5% to 46.0%, preferably 42.0% to 46.0%, and more preferably 44.5% to 46.0%. The degree of polarization of the polarizer is preferably 97.0% or more, more preferably 99.0% or more, and still more preferably 99.9% or more.

A polarizer can be produced by any suitable method. Specifically, the polarizer may be produced from a single layer resin film or may be produced using a laminate of two or more layers.

The method for producing a polarizer from the above-mentioned single-layer resin film typically includes subjecting the resin film to a dyeing treatment with a dichroic substance such as iodine or a dichroic dye, and a stretching treatment. As the 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 used. The method may further include insolubilization treatment, swelling treatment, crosslinking treatment, and the like. Since such a manufacturing method is well known and commonly used in the art, detailed explanation will be omitted.

A polarizer obtained using the above-mentioned laminate can be produced using, for example, a laminate of a resin base material and a resin film or a resin layer (typically, a PVA-based resin layer). Specifically, applying a PVA-based resin solution to a resin base material and drying it to form a PVA-based resin layer on the resin base material to obtain a laminate of the resin base material and the PVA-based resin layer; It can be produced by stretching and dyeing the laminate to use the PVA resin layer as a polarizer. In this embodiment, preferably, a PVA-based resin layer containing a halide and a PVA-based 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. can be achieved. Furthermore, when the PVA-based resin layer is immersed in a liquid, disturbance of the orientation of PVA molecules and deterioration of the orientation can be suppressed compared to when the PVA-based resin layer does not contain a halide, and high optical properties can be achieved. It can be achieved. Furthermore, high optical properties can be achieved by shrinking the laminate in the width direction through drying shrinkage treatment. A polarizing plate can be obtained by laminating a protective layer on the peeled surface where the resin base material is peeled from the obtained resin base material/polarizer laminate, or on the surface opposite to the peeled surface. Details of the method for manufacturing such a polarizer 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.

A-2-2. First Protective Layer The first protective layer may be formed of, for example, any suitable resin film that can be used as a protective layer of a polarizer. Specific examples of resins that are the main components of the resin film include cellulose resins such as triacetyl cellulose (TAC), polyester resins, polyvinyl alcohol resins, polycarbonate resins, polyamide resins, polyimide resins, and polyethers. Examples include sulfone resins, polysulfone resins, polystyrene resins, cycloolefin resins such as polynorbornene, polyolefin resins, (meth)acrylic resins, acetate resins, and the like.

The polarizing plate with a retardation layer is typically placed on the viewing side of an image display device (for example, an organic EL display device), and the first protective layer is placed on the viewing side. Therefore, the first protective layer may be subjected to surface treatments such as hard coat (HC) treatment, antireflection treatment, antisticking treatment, and antiglare treatment, as necessary.

The thickness of the first protective layer is preferably 5 μm to 80 μm, more preferably 10 μm to 40 μm, and even more preferably 15 μm to 35 μm. In addition, when the said surface treatment is performed, the thickness of a 1st protective layer is the thickness including the thickness of a surface treatment layer.

A-2-3. Second Protective Layer The second protective layer may be formed of, for example, any suitable resin film that can be used as a protective layer of a polarizer. The same explanation as for the first protective layer can be applied to the second protective layer when it is formed of a resin film. For example, the second protective layer may be a solidified layer or a hardened layer of a coating film of an organic solvent solution containing a resin. When the second protective layer is a solidified layer or a hardened layer of a coating film of an organic solvent solution containing a resin, the adhesion to the polarizer can be improved.

In one embodiment, the resin (base polymer) forming the solidified layer or hardened layer may have a glass transition temperature (Tg) of 85° C. or higher, and a weight average molecular weight Mw of 25,000 or higher. When the Tg and Mw of the resin are within these ranges, excellent durability in a high temperature and high humidity environment can be achieved despite the extremely thin thickness. The Tg of the resin is preferably 90°C or higher, more preferably 100°C or higher, even more preferably 110°C or higher, and particularly preferably 120°C or higher. Tg can be, for example, 200°C or less. Further, the Mw of the resin is preferably 30,000 or more, more preferably 35,000 or more, and still more preferably 40,000 or more. Mw can be, for example, 150,000 or less.

As the resin, any suitable resin can be used as long as it can form a solidified or cured product (for example, a thermoset) of a coating film of an organic solvent solution. Thermoplastic resins or thermosetting resins having Tg and Mw as described above are preferred, and thermoplastic resins are more preferred. Only one type of resin may be used, or two or more types may be used in combination.

Examples of thermoplastic resins include acrylic resins and epoxy resins. You may use a combination of an acrylic resin and an epoxy resin.

Acrylic resins typically contain repeating units derived from (meth)acrylic acid ester monomers having a linear or branched structure as a main component. The acrylic resin may contain repeating units derived from any suitable comonomer depending on the purpose. Examples of the comonomer (comonomer) include carboxyl group-containing monomers, hydroxyl group-containing monomers, amide group-containing monomers, aromatic ring-containing (meth)acrylates, and heterocycle-containing vinyl monomers. By appropriately setting the type, number, combination, copolymerization ratio, etc. of monomer units, an acrylic resin having the above-mentioned predetermined Tg and Mw can be obtained. Specific examples of the acrylic resin include boron-containing acrylic resins and lactone ring-containing acrylic resins described in [0034] to [0056] of JP-A No. 2021-117484.

As the epoxy resin, preferably an epoxy resin having an aromatic ring is used. By using an epoxy resin having an aromatic ring as the epoxy resin, the adhesion between the protective layer and the polarizer can be improved. Furthermore, when the adhesive layer is disposed adjacent to the protective layer, the anchoring power of the adhesive layer can be improved. Examples of epoxy resins having an aromatic ring include bisphenol epoxy resins such as bisphenol A epoxy resin, bisphenol F epoxy resin, and bisphenol S epoxy resin; phenol novolak epoxy resin, cresol novolac epoxy resin, and hydroxybenzaldehyde phenol novolak. Novolak type epoxy resin such as epoxy resin; polyfunctional type epoxy resin such as glycidyl ether of tetrahydroxyphenylmethane, glycidyl ether of tetrahydroxybenzophenone, epoxidized polyvinylphenol, naphthol type epoxy resin, naphthalene type epoxy resin, biphenyl type Examples include epoxy resin. Preferably, bisphenol A type epoxy resin, biphenyl type epoxy resin, and bisphenol F type epoxy resin are used. Only one type of epoxy resin may be used, or two or more types may be used in combination.

The second protective layer may be formed by applying an organic solvent solution of the resin to form a coating film, and solidifying or thermosetting the coating film. As the organic solvent, any suitable organic solvent that can dissolve or uniformly disperse the acrylic resin or epoxy resin can be used. Specific examples of organic solvents include ethyl acetate, toluene, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), cyclopentanone, and cyclohexanone. The resin concentration of the solution is preferably 3 to 20 parts by weight based on 100 parts by weight of the solvent. With such a resin concentration, a uniform coating film can be formed.

The solution may be applied to any suitable substrate or may be applied to a polarizer. When applying a solution to a base material, the solidified or cured product (resin layer) of the coating film formed on the base material is transferred to a polarizer. When a solution is applied to a polarizer, a protective layer is directly formed on the polarizer by drying (solidifying) or curing the coating film. Preferably, the solution is applied to a polarizer to form a protective layer directly on the polarizer. With such a configuration, the adhesive layer or pressure-sensitive adhesive layer required for transfer can be omitted, so the polarizing plate can be made even thinner. Any suitable method can be adopted as a method for applying the solution. Specific examples include roll coating, spin coating, wire bar coating, dip coating, die coating, curtain coating, spray coating, and knife coating (comma coating, etc.).

A protective layer can be formed by solidifying or thermally curing a coating film of a solution. The heating temperature for solidification or thermosetting is preferably 100°C or lower, more preferably 50°C to 70°C. If the heating temperature is within this range, adverse effects on the polarizer can be prevented. Heating time can vary depending on the heating temperature. The heating time can be, for example, 1 minute to 10 minutes.

The second protective layer (substantially an organic solvent solution of the resin) may contain any suitable additives depending on the purpose. Specific examples of additives include ultraviolet absorbers; leveling agents; antioxidants such as hindered phenol, phosphorus, and sulfur; stabilizers such as light stabilizers, weather stabilizers, and heat stabilizers; glass fibers; Reinforcing materials such as carbon fibers; near-infrared absorbers; flame retardants such as tris(dibromopropyl) phosphate, triallyl phosphate, and antimony oxide; antistatic agents such as anionic, cationic, and nonionic surfactants; inorganic pigments , coloring agents such as organic pigments and dyes; organic fillers or inorganic fillers; resin modifiers; organic fillers and inorganic fillers; plasticizers; lubricants; flame retardants and the like. The type, number, combination, amount, etc. of additives can be appropriately set depending on the purpose.

The thickness of the second protective layer when it is a solidified layer or a hardened layer of a coating film of an organic solvent solution containing a resin is preferably 0.05 μm to 10 μm, more preferably 0.08 μm to 5 μm, and even more preferably is 0.1 μm to 1 μm, particularly preferably 0.2 μm to 0.7 μm.

A-3. First Retardation Layer The first retardation layer 30 may have any appropriate optical properties and/or mechanical properties depending on the purpose. The first retardation layer typically has a slow axis. In one embodiment, the angle θ between the slow axis of the first retardation layer 30 and the absorption axis of the polarizer 12 is, for example, 40° to 50°, preferably 42° to 48°, More preferably, it is about 45°. If the angle θ is in such a range, by using a λ/4 plate as the first retardation layer, a retardation layer having extremely excellent circularly polarizing properties (as a result, extremely excellent antireflection properties) can be obtained. A polarizing plate can be obtained.

The first retardation layer preferably exhibits a refractive index characteristic of nx>ny≧nz. In one embodiment, the first retardation layer can function as a λ/4 plate. In this case, the in-plane retardation Re (550) of the first retardation layer is, for example, 100 nm to 190 nm, preferably 110 nm to 170 nm, and more preferably 130 nm to 160 nm. Note that "ny=nz" here includes not only the case where ny and nz are completely equal, but also the case where they 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 retardation layer is preferably 0.9 to 3, more preferably 0.9 to 2.5, even more preferably 0.9 to 1.5, particularly preferably 0.9 to 1.3. It is. By satisfying such a relationship, when the obtained polarizing plate with a retardation layer is used in an image display device, an extremely excellent reflected hue can be achieved.

The first retardation layer may exhibit inverse dispersion wavelength characteristics in which the retardation value increases depending on the wavelength of the measurement light, and may exhibit positive wavelength dispersion characteristics in which the retardation value decreases in accordance with the wavelength of the measurement light. Alternatively, the phase difference value may exhibit flat wavelength dispersion characteristics that hardly change depending on the wavelength of the measurement light. In one embodiment, the first retardation layer exhibits inverse dispersion wavelength characteristics. In this case, Re(450)/Re(550) of the retardation layer is, for example, 0.8 or more and less than 1, preferably 0.8 or more and 0.95 or less. With such a configuration, extremely excellent antireflection properties can be achieved.

The absolute value of the photoelastic coefficient of the first retardation layer is preferably 2×10 ⁻¹¹ m ² /N or less, more preferably 2.0×10 ⁻¹³ m ² /N to 1.5×10 ⁻¹¹ m ² /N, more preferably 1.0×10 ⁻¹² m ² /N to 1.2× ^{10 −11} m ² /N. If the absolute value of the photoelastic coefficient is within this range, phase difference changes are unlikely to occur when shrinkage stress occurs during heating. As a result, thermal unevenness in the resulting image display device can be effectively prevented.

The first retardation layer is typically composed of a stretched resin film. The thickness of the first retardation layer is, for example, 10 μm or more, preferably 10 μm to 70 μm, more preferably 10 μm to 50 μm, and still more preferably 20 μm to 40 μm. If the thickness of the first retardation layer is within such a range, it is possible to satisfactorily suppress curling during heating and to satisfactorily adjust curling during bonding.

The first retardation layer may be composed of any suitable resin film that can satisfy the above characteristics. Typical examples of such resins include polycarbonate resins, polyester carbonate resins, polyester resins, polyvinyl acetal resins, polyarylate resins, cyclic olefin resins, cellulose resins, polyvinyl alcohol resins, and polyamide resins. , polyimide resin, polyether resin, polystyrene resin, and acrylic resin. These resins may be used alone or in combination (for example, blended or copolymerized). When the first retardation layer is composed of a resin film exhibiting reverse dispersion wavelength characteristics, polycarbonate resin or polyester carbonate resin (hereinafter sometimes simply referred to as polycarbonate resin) may be suitably used.

Any suitable polycarbonate resin can be used as the polycarbonate resin as long as the effects of the present invention can be obtained. 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 retardation layer and the method for forming the first retardation layer can be found, for example, in JP-A No. 2014-10291, JP-A No. 2014-26266, and JP-A No. 2015-2015. It is described in JP-A-212816, JP-A-2015-212817, and JP-A-2015-212818, and the descriptions of these publications are incorporated herein by reference.

The first retardation layer may contain any suitable additive depending on the purpose. Specific examples of additives include ultraviolet absorbers; leveling agents; antioxidants; stabilizers such as light stabilizers, weather stabilizers, and heat stabilizers; and the like. In one embodiment, the first retardation layer contains an ultraviolet absorber. The UV absorption capacity usually increases in proportion to the thickness of the material. Therefore, by adding an ultraviolet absorber to the first retardation layer that is made of a resin film and has a predetermined thickness, the addition concentration can be reduced, and as a result, excessive addition can be avoided. Solubility can be ensured and precipitation problems can be prevented. The type, number, combination, amount, etc. of additives can be appropriately set depending on the purpose.

In one embodiment, the second main surface side of the first retardation layer is brought into contact with an organic solvent, and then an adhesive layer is provided on the contact surface. A compatible region in which the composition changes continuously from the first retardation layer side to the adhesive layer side can be formed. Formation of a compatible region in which the components of the first retardation layer and the components of the adhesive layer are compatible with each other can improve the adhesiveness between the first retardation layer and the second retardation layer. On the other hand, from the viewpoint of severely suppressing moisture penetration into the first retardation layer (as a result, swelling of the first retardation layer), it is preferable not to provide a compatible region. Therefore, it is preferable that the compatible region is formed as necessary, taking into consideration the adhesion between the first retardation layer and the second retardation layer, the use of the polarizing plate with the retardation layer, the usage environment, etc. Details of the method for forming the compatible region are described in JP-A-2019-56820, and the description is incorporated herein as a reference.

A-4. Second Retardation Layer The second retardation layer 50 may typically be a so-called positive C plate whose refractive index characteristics exhibit a relationship of nz>nx=ny. By using a positive C plate as the second retardation layer, reflection in an oblique direction can be effectively prevented, and the antireflection function can provide a wide viewing angle.

The retardation Rth (550) in the thickness direction of the second retardation layer is preferably -50 nm to -300 nm, more preferably -70 nm to -250 nm, even more preferably -90 nm to -200 nm, particularly preferably -100 nm to - It is 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. That is, the in-plane retardation Re(550) of the second retardation layer may be less than 10 nm.

The second retardation layer having a refractive index characteristic of nz>nx=ny may be formed of any suitable material. The second retardation layer preferably consists of a film containing a liquid crystal material fixed in a homeotropic alignment. The liquid crystal material (liquid crystal compound) that can be homeotropically aligned may be a liquid crystal monomer or a liquid crystal polymer. Specific examples of the liquid crystal compound and the method for forming the retardation layer include the liquid crystal compound and the method for forming the retardation layer described in [0020] to [0028] of JP-A No. 2002-333642. In this case, the thickness of the second retardation layer is preferably 0.5 μm to 10 μm, more preferably 0.5 μm to 8 μm, and even more preferably 0.5 μm to 5 μm.

A-5. Adhesive layer The first adhesive layer 20 and the second adhesive layer 60 (hereinafter, the first adhesive layer and the second adhesive layer may be collectively referred to as the adhesive layer) are each stored at 110°C. The elastic modulus is preferably 0.01 MPa or more, more preferably 0.01 MPa to 1 MPa, and even more preferably 0.02 MPa to 0.5 MPa. Further, the storage modulus of each of the first adhesive layer 20 and the second adhesive layer 60 at 23° C. is preferably 0.05 MPa or more, more preferably 0.05 MPa to 1 MPa, and more preferably 0.05 MPa or more. 07 MPa to 0.5 MPa. By using an adhesive layer having such a storage modulus, it is possible to suppress thermal shrinkage of the first retardation layer under high temperature and high humidity, and as a result, the effects of the present invention can be more suitably obtained. obtain.

The adhesive constituting the adhesive layer typically contains a (meth)acrylic polymer, a urethane polymer, a silicone polymer, or a rubber polymer as a base polymer, preferably a (meth)acrylic polymer. contains. When a (meth)acrylic polymer is used as the base polymer, the adhesive layer is formed, for example, from an adhesive containing a (meth)acrylic polymer.

A-5-1. (Meth)acrylic polymer The (meth)acrylic polymer preferably has a structural unit derived from an alkyl (meth)acrylate having an alkyl group having 1 to 30 carbon atoms in the side chain. The alkyl group may be linear or branched. Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, isoheptyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate , isooctyl (meth)acrylate, n-nonyl (meth)acrylate, isononyl (meth)acrylate, n-decyl (meth)acrylate, isodecyl (meth)acrylate, n-dodecyl (meth)acrylate (lauryl (meth)acrylate), Examples include n-tridecyl (meth)acrylate and n-tetradecyl (meth)acrylate. Further, an alkyl (meth)acrylate having a long chain alkyl group (for example, an alkyl group having 6 to 30 carbon atoms) in a side chain such as n-dodecyl (meth)acrylate (lauryl (meth)acrylate) can also be used. One or more types of alkyl (meth)acrylates may be used.

The content of alkyl (meth)acrylate in all the monomers constituting the (meth)acrylic polymer is, for example, 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more, and still more preferably 80% by weight or more. It is. The upper limit of the content ratio may be, for example, 99.9% by weight or less.

The (meth)acrylic polymer may have structural units other than those derived from alkyl (meth)acrylate. The structural unit is derived from a monomer copolymerizable with an alkyl (meth)acrylate (copolymerizable monomer). The (meth)acrylic polymer may have one or more types of structural units derived from copolymerization monomers.

Examples of copolymerizable monomers include aromatic ring-containing monomers. The aromatic ring-containing monomer may be an aromatic ring-containing (meth)acrylic monomer. Specific examples of aromatic ring-containing monomers include phenyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, ethylene oxide-modified nonylphenol (meth)acrylate, and hydroxyethylated β- Examples include naphthol (meth)acrylate and biphenyl (meth)acrylate. The content ratio of the aromatic ring-containing monomer in all the monomers constituting the (meth)acrylic polymer is, for example, 0% to 50% by weight, 1% to 30% by weight, 5% to 25% by weight, and 8% by weight. % to 20% by weight.

Another example of the copolymerizable monomer is (meth)acrylate shown in the following chemical formula (1). R ¹ in formula (1) is an alkyl group. The alkyl group may be linear or branched. R ¹ is preferably a linear alkyl group. Examples of R ¹ are methyl and ethyl groups. n in formula (1) is an integer from 1 to 15.

Specific examples of the (meth)acrylate shown in formula (1) include 2-methoxyethyl (meth)acrylate, 2-ethoxyethyl (meth)acrylate, and methoxytriethylene glycol (meth)acrylate. By using the (meth)acrylate of formula (1), when an antistatic agent is blended into the pressure-sensitive adhesive layer, it is possible to realize a pressure-sensitive adhesive layer with a low surface resistivity with a small amount blended. The content ratio of the (meth)acrylate of formula (1) in all the monomers constituting the (meth)acrylic polymer is, for example, 5% to 95% by weight, 10% to 90% by weight, 20% to 80% by weight. % by weight, or from 25% to 75% by weight.

The copolymerizable monomer may be a polar group-containing monomer selected from carboxyl group-containing monomers, amino group-containing monomers, hydroxyl group-containing monomers, and amide group-containing monomers. According to the base polymer having a polar group, when an antistatic agent is blended, outflow of the antistatic agent can be suppressed more suitably. Specific examples of carboxyl group-containing monomers include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Specific examples of the amino group-containing monomer include N,N-dimethylaminoethyl (meth)acrylate and N,N-dimethylaminopropyl (meth)acrylate. Specific examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl ( Hydroxyalkyl (meth)acrylates such as meth)acrylate, 10-hydroxydecyl (meth)acrylate, and 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)-methyl acrylate. Specific examples of amide group-containing monomers include (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropylacrylamide, N-methyl(meth)acrylamide, N- Butyl (meth)acrylamide, N-hexyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methylol-N-propane (meth)acrylamide, aminomethyl (meth)acrylamide, aminoethyl (meth)acrylamide, mercaptomethyl Acrylamide monomers such as (meth)acrylamide and mercaptoethyl (meth)acrylamide; N-acryloyl heterocyclic monomers such as N-(meth)acryloylmorpholine, N-(meth)acryloylpiperidine, and N-(meth)acryloylpyrrolidine ; and N-vinyl group-containing lactam monomers such as N-vinylpyrrolidone and N-vinyl-ε-caprolactam.

The total content of the polar group-containing monomers in all the monomers constituting the (meth)acrylic polymer is, for example, 15% by weight or less, preferably 0.1% to 10% by weight, more preferably 0.1% by weight or less. It is 1% to 5% by weight. When a (meth)acrylic polymer is used in combination with an antistatic agent, the total content of the polar group-containing monomers in all monomers constituting the (meth)acrylic polymer is, for example, 0.1% by weight or more, and is preferably is 0.5% to 10% by weight, more preferably 0.5% to 8% by weight.

The copolymerizable monomer may be a polyfunctional monomer. Examples of polyfunctional monomers include hexanediol di(meth)acrylate (1,6-hexanediol di(meth)acrylate), butanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly) Propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, trimethylolpropane tri(meth)acrylate , polyfunctional acrylates such as tetramethylolmethane tri(meth)acrylate, allyl(meth)acrylate, vinyl(meth)acrylate, epoxy acrylate, polyester acrylate, and urethane acrylate; and divinylbenzene. Preferred examples of the polyfunctional acrylate include 1,6-hexanediol diacrylate and dipentaerythritol hexa(meth)acrylate.

The content of the polyfunctional monomer in all the monomers constituting the (meth)acrylic polymer is preferably 1% by weight or less, more preferably 0.9% by weight or less, even more preferably 0.8% by weight or less. be. The lower limit of the total content ratio is, for example, 0.01% by weight or more, and may be 0.015% by weight or more, or 0.02% by weight or more. The (meth)acrylic polymer does not need to contain structural units derived from polyfunctional monomers.

Other copolymerizable monomers include epoxy group-containing monomers such as glycidyl (meth)acrylate and methylglycidyl (meth)acrylate; sulfonic acid group-containing monomers such as sodium vinyl sulfonate; phosphoric acid group-containing monomers; (Meth)acrylic acid esters having alicyclic hydrocarbon groups such as cyclopentyl acrylate, cyclohexyl (meth)acrylate, and isobornyl (meth)acrylate; Vinyl esters such as vinyl acetate and vinyl propionate; styrene, vinyl Examples include aromatic vinyl compounds such as toluene; olefins or dienes such as ethylene, propylene, butadiene, isoprene, and isobutylene; vinyl ethers such as vinyl alkyl ether; and vinyl chloride.

The total content of the other copolymerizable monomers in all the monomers constituting the (meth)acrylic polymer is, for example, 30% by weight or less, preferably 10% by weight or less, and may be 0% by weight.

The (meth)acrylic polymer can be formed by polymerizing one or more of the above-mentioned monomers by a known method. A monomer and a partial polymer (oligomer) of the monomer may be polymerized. Using a monomer with a high glass transition temperature (Tg) (for example, methyl (meth)acrylate, phenoxyethyl acrylate, benzyl acrylate, etc.) and/or an oligomer with a high Tg, and the resulting (meth)acrylic polymer with a high Tg. A highly elastic pressure-sensitive adhesive layer can be obtained by combining it with an additive (for example, a crosslinking agent). Polymerization can be carried out by, for example, solution polymerization, emulsion polymerization, bulk polymerization, thermal polymerization, or active energy ray polymerization (eg, UV polymerization). From the viewpoint of forming an adhesive layer with excellent optical transparency, solution polymerization or active energy ray polymerization is preferred.

The weight average molecular weight (Mw) of the (meth)acrylic polymer is, for example, 1 million to 2.8 million, and from the viewpoint of the durability and heat resistance of the adhesive layer, it is preferably 1.2 million or more, more preferably 1.4 million. That's all. The weight average molecular weight (Mw) is determined as a value (in terms of polystyrene) based on GPC (gel permeation chromatography) measurement.

The content of the (meth)acrylic polymer in the adhesive is, for example, 50% by weight or more, preferably 60% by weight or more, more preferably 70% by weight or more, and still more preferably 80% by weight or more. be. The upper limit of the content ratio may be, for example, 99.9% by weight or less, preferably 99.8% by weight or less.

A-5-2. Antistatic Agent As mentioned above, at least one of the first adhesive layer and the second adhesive layer contains an antistatic agent. The surface resistivity of the adhesive layer containing the antistatic agent is preferably 9.0×10 ¹¹ Ω/□ or less, more preferably 1.0×10 ⁸ Ω/□ to 8.0×10 ¹¹ Ω/□, More preferably, it is 5.0×10 ⁸ Ω/□ to 6.0×10 ¹¹ Ω/□.

Examples of the antistatic agent include ionic compounds such as salts, conductive polymers, and the like. The antistatic agent may be used alone or in combination of two or more.

Examples of ionic compounds include ionic liquids that are liquid at room temperature (25°C). When blended into the adhesive layer, the ionic compound has high compatibility with the base polymer (typically (meth)acrylic polymer) and can maintain optical transparency.

Cations constituting the ionic compound include metal ions and onium ions. Metal ions include alkali metal ions and alkaline earth metal ions. Alkali metal ions are, for example, lithium ions, sodium ions, and potassium ions, and may also be lithium ions. Alkaline earth metal ions are, for example, magnesium ions and calcium ions.

Examples of onium ions include ions in which at least one atom selected from nitrogen atoms, phosphorus atoms, and sulfur atoms is positively charged (+). The onium ion may be an organic ion, and in this case, it may be an ion of a cyclic organic compound or an ion of a chain organic compound. The cyclic organic compound may be aromatic or non-aromatic such as aliphatic. Specific examples of onium ions include N-ethyl-N,N-dimethyl-N-(2-methoxyethyl)ammonium ion, N,N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium ion, N-ethyl-N,N-dimethyl-N-propylammonium ion, N-methyl-N,N,N-trioctylammonium ion, N,N,N-trimethyl-N-propylammonium ion, tetrabutylammonium ion, Quaternary ammonium ions such as tetramethylammonium ion, tetrahexylammonium ion, and N-methyl-N,N,N-tributylammonium ion; Pyridinium such as N-alkylpyridinium substituted with an alkyl group having 4 to 16 carbon atoms Ion: 1,3-alkylmethylimidazolium ion substituted with an alkyl group having 2 to 10 carbon atoms (e.g. ethyl group), 1,2-dimethyl-3-alkyl substituted with an alkyl group having 2 to 10 carbon atoms Imidazolium ions such as imidazolium; phosphonium ions, pyrrolidinium ions, pyridazinium ions, pyrimidinium ions, pyrazinium ions, pyrazolium ions, thiazolium ions, oxazolium ions, triazolium ions, and piperidinium ions Can be mentioned.

Specific examples of anions constituting the ionic compound include fluoride, chloride, bromide, iodide, perchlorate (ClO ₄ ⁻ ), hydroxide (OH ⁻ ), carbonate (CO ₃ ²⁻ ), and nitrate (NO ₃ ⁻ ). , sulfonate (SO ₄ ⁻ ), methylbenzenesulfonate (CH ₃ (C ₆ H ₄ )SO ₃ ⁻ ), p-toluenesulfonate (CH ₃ C ₆ H ₄ SO ₃ ⁻ ), carboxybenzenesulfonate (COOH (C ₆ H ₄ ) SO ₃ ⁻ ), trifluoromethanesulfonate (CF ₃ SO ₂ ⁻ ), benzoate (C ₆ H ₅ COO ⁻ ), acetate (CH ₃ COO ⁻ ), trifluoroacetate (CF ₃ COO ⁻ ), tetrafluoroborate ( BF ₄ ⁻ ), tetrabenzylborate (B(C ₆ H ₅ ) ₄ ⁻ ), hexafluorophosphate (PF ₆ ⁻ ), trispentafluoroethyl trifluorophosphate (P(C ₂ F ₅ ) ₃ F ₃ ⁻ ), Bisfluorosulfonylimide (N(SO ₂ F) ₂ ⁻ ), bistrifluoromethanesulfonylimide (N(SO ₂ CF ₃ ) ₂ ⁻ ), bispentafluoroethanesulfonylimide (N(SOC ₂ F ₅ ) ₂ ⁻ ), Bispentafluoroethanecarbonylimide (N(COC ₂ F ₅ ) ₂ ⁻ ), bisperfluorobutanesulfonylimide (N(SO ₂ C ₄ F ₉ ) ₂ ⁻ ), bisperfluorobutane carbonylimide (N(COC ₄ F ₉ ) ₂ ⁻ ), tristrifluoromethanesulfonylmethide (C(SO ₂ CF ₃ ) ₃ ⁻ ), and tristrifluoromethanecarbonylmethide (C(SO ₂ CF ₃ ) ₃ ⁻ ).

The ionic compound may contain an anion containing a sulfur atom. Specific examples of anions containing a sulfur atom include bisfluorosulfonylimide (N(SO ₂ F) ₂ ⁻ ) and bistrifluoromethanesulfonylimide (N(SO ₂ CF ₃ ) ₂ ⁻ ).

The ionic compound may be an organic salt. Further, the ionic compound may be a lithium salt, or a lithium organic salt containing a lithium ion and an organic ion as a cation and an anion, respectively.

Specific examples of ionic compounds include 1-ethyl-3-methylimidazolium bisfluorosulfonylimide, lithium bis(trifluoromethanesulfonyl)imide (LiTFSi), and ethylmethylpyrrolidinium bis(trifluoromethanesulfonyl)imide (EMP-TFSi). ) and tributylmethylammonium bis(trifluoromethanesulfonyl)imide (TBMA-TFSi).

The ionic compound does not need to contain a phosphorus atom. Ionic compounds containing phosphorus atoms tend to corrode the touch panel (more specifically, the conductive layer of the touch panel).

Examples of the conductive polymer include polythiophene, polyaniline, polypyrrole, polyquinoxaline, polyacetylene, polyphenylene vinylene, polynaphthalene, and derivatives thereof. The conductive polymer is preferably polythiophene, polyaniline, and derivatives thereof, more preferably polythiophene derivatives.

The conductive polymer may have a hydrophilic functional group. Examples of hydrophilic functional groups include sulfone groups, amino groups, amide groups, imino groups, hydroxyl groups, mercapto groups, hydrazino groups, carboxyl groups, sulfate ester groups, phosphate ester groups, and salts thereof (for example, quaternary ammonium base).

From the viewpoint of conductivity and chemical stability, the conductive polymer is preferably poly(3,4-disubstituted thiophene). Poly(3,4-disubstituted thiophene) includes poly(3,4-alkylenedioxythiophene) and poly(3,4-dialkoxythiophene), preferably poly(3,4-disubstituted thiophene). oxythiophene). Poly(3,4-alkylenedioxythiophene) has, for example, a structural unit represented by the following formula (2).

R ² in formula (2) is, for example, an alkylene group having 1 to 4 carbon atoms. The alkylene group may be linear or branched. Examples of alkylene groups include methylene group, 1,2-ethylene group, 1,3-propylene group, 1,4-butylene group, 1-methyl-1,2-ethylene group, and 1-ethyl-1,2-ethylene group. group, 1-methyl-1,3-propylene group, and 2-methyl-1,3-propylene group, preferably methylene group, 1,2-ethylene group, and 1,3-propylene group, more preferably is a 1,2-ethylene group. The conductive polymer may be poly(3,4-ethylenedioxythiophene) (PEDOT).

A polyanion may be used as the dopant. When the conductive polymer is polythiophene (or a derivative thereof), the polyanion may form an ion pair with the polythiophene (or derivative thereof). The polyanion is not particularly limited, and includes, for example, carboxylic acid polymers such as polyacrylic acid, polymaleic acid, and polymethacrylic acid; and sulfonic acid polymers such as polystyrene sulfonic acid, polyvinyl sulfonic acid, and polyisoprene sulfonic acid. The polyanion may be a copolymer of vinyl carboxylic acids or vinyl sulfonic acids and other monomers. Other monomers include (meth)acrylate compounds; aromatic vinyl compounds such as styrene and vinylnaphthalene. The polyanion is preferably polystyrene sulfonic acid (PSS). The conductive polymer that is a complex with a dopant can be, for example, a complex of poly(3,4-ethylenedioxythiophene) and polystyrene sulfonic acid (PEDOT/PSS).

The amount of antistatic agent added in the adhesive layer is typically 5 phr (per hundred resin) or less. Specifically, the amount of the antistatic agent in the adhesive layer is typically 5 parts by weight or less, preferably 0.05 parts to 4 parts by weight, more preferably 0.05 parts by weight to 4 parts by weight, based on 100 parts by weight of the base polymer. The amount is 0.1 parts by weight to 3 parts by weight. If the amount of the antistatic agent exceeds 5 phr, the antistatic agent may leak into the image display panel and cause adverse effects. In addition, the adhesive layer may become plasticized and the effect of suppressing the first retardation layer from shrinking due to heat or swelling due to moisture absorption may be reduced. In one embodiment, the amount of the antistatic agent containing a phosphorus atom in the adhesive layer is preferably 2.5 parts by weight or less, more preferably 2 parts by weight or less, and even more preferably may be 1.5 parts by weight or less, for example 0 parts by weight.

A-5-3. Additives The adhesive may further contain additives other than antistatic agents. Specific examples of additives include silane coupling agents, crosslinking agents, antioxidants, colorants, powders such as pigments, dyes, surfactants, plasticizers, tackifiers, surface lubricants, leveling agents, Examples include softeners, anti-aging agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, inorganic or organic fillers, metal powders, particles, and foils. Further, within a controllable range, a redox system may be employed in which a reducing agent is added. The type, number, combination, content, etc. of additives can be set to any appropriate value depending on the purpose.

Examples of crosslinking agents include organic crosslinking agents and polyfunctional metal chelates. Examples of organic crosslinking agents are isocyanate crosslinking agents, peroxide crosslinking agents, epoxy crosslinking agents, and imine crosslinking agents. The crosslinking agent is preferably a peroxide crosslinking agent or an isocyanate crosslinking agent. Only one type of crosslinking agent may be used, or two or more types may be used in combination. For example, a peroxide-based crosslinking agent and an isocyanate-based crosslinking agent can be used together.

The blending amount of the crosslinking agent in the adhesive is, for example, 0.01 parts by weight to 10 parts by weight, preferably 0.1 parts by weight to 5 parts by weight, more preferably is 0.1 parts by weight to 3 parts by weight.

A typical example of the silane coupling agent is a functional group-containing silane coupling agent. Examples of functional groups include epoxy groups, mercapto groups, amino groups, isocyanate groups, isocyanurate groups, vinyl groups, styryl groups, acetoacetyl groups, ureido groups, thiourea groups, (meth)acrylic groups, heterocyclic groups, and acid groups. Includes anhydride groups and combinations thereof. Only one type of silane coupling agent may be used, or two or more types may be used in combination.

The amount of the silane coupling agent in the adhesive is, for example, 0.01 to 5 parts by weight, preferably 0.01 to 3 parts by weight, based on 100 parts by weight of the (meth)acrylic polymer. More preferably, it is 0.01 part by weight to 1 part by weight.

The thickness of the first adhesive layer is typically 1 μm to 25 μm, preferably 2 μm to 20 μm, and more preferably 3 μm to 18 μm.

The thickness of the second adhesive layer is typically 5 μm to 50 μm, preferably 7 μm to 40 μm, and more preferably 10 μm to 30 μm.

A-6. Adhesive Layer Any suitable adhesive may be employed as the adhesive constituting the adhesive layer 40. Typical examples of the adhesive include active energy ray-curable adhesives. Examples of active energy ray curable adhesives include ultraviolet ray curable adhesives and electron beam curable adhesives. From the viewpoint of the curing mechanism, active energy ray-curable adhesives include, for example, radical-curable adhesives, cation-curable adhesives, anion-curable adhesives, and hybrids of radical-curable and cationic-curable adhesives. Typically, a radical-curable ultraviolet curable adhesive may be used. This is because it has excellent versatility and its characteristics can be easily adjusted.

The adhesive typically contains a curing component and a photopolymerization initiator. The curing component typically includes monomers and/or oligomers having functional groups such as (meth)acrylate groups and (meth)acrylamide groups. Specific examples of curing components include tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecanedimethanol diacrylate, phenoxydiethylene glycol acrylate, cyclic trimethylolpropane formal acrylate, dioxane glycol diacrylate, and EO modification. Diglycerin tetraacrylate, γ-butyrolactone acrylate, acryloylmorpholine, unsaturated fatty acid hydroxyalkyl ester modified ε-caprolactone, N-methylpyrrolidone, hydroxyethylacrylamide, N-methylolacrylamide, N-methoxymethylacrylamide, N-ethoxymethylacrylamide Can be mentioned. These curing components may be used alone or in combination of two or more.

The adhesive may include a curing component having a heterocycle. Examples of the curing component having a heterocycle include acryloylmorpholine, γ-butyrolactone acrylate, unsaturated fatty acid hydroxyalkyl ester modified ε-caprolactone, and N-methylpyrrolidone.

The adhesive may further contain an oligomer component in addition to the above-mentioned curing component. By using the oligomer component, the viscosity of the adhesive before curing can be reduced and the operability can be improved. A typical example of the oligomer component is a (meth)acrylic oligomer. Examples of (meth)acrylic monomers constituting the (meth)acrylic oligomer include (meth)acrylic acid (carbon number 1 to 20) alkyl esters, cycloalkyl (meth)acrylates (such as cyclohexyl (meth)acrylate, cyclopentyl (meth)acrylate, etc.), aralkyl (meth)acrylates (e.g., benzyl (meth)acrylate, etc.), polycyclic (meth)acrylates (e.g., 2-isobornyl (meth)acrylate, 2-norbornylmethyl (meth)acrylate, etc. ) acrylate, 5-norbornen-2-yl-methyl (meth)acrylate, 3-methyl-2-norbornylmethyl (meth)acrylate, etc.), hydroxyl group-containing (meth)acrylic esters (for example, hydroxyethyl ( (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2,3-dihydroxypropylmethyl-butyl (meth)methacrylate, etc.), (meth)acrylic acid esters containing an alkoxy group or phenoxy group (2-methoxyethyl (meth)acrylate, etc.) Acrylate, 2-ethoxyethyl (meth)acrylate, 2-methoxymethoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, ethyl carbitol (meth)acrylate, phenoxyethyl (meth)acrylate, etc.), epoxy group-containing (meth)acrylic esters (e.g., glycidyl (meth)acrylate, etc.), halogen-containing (meth)acrylic esters (e.g., 2,2,2-trifluoroethyl (meth)acrylate, 2,2,2- trifluoroethyl ethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate, hexafluoropropyl (meth)acrylate, octafluoropentyl (meth)acrylate, heptadecafluorodecyl (meth)acrylate, etc.), alkylaminoalkyl (meth)acrylate Acrylates (eg, dimethylaminoethyl (meth)acrylate, etc.) can be mentioned. Specific examples of (meth)acrylic acid (1 to 20 carbon atoms) alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, and 2-methyl -2-Nitropropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, t- Pentyl (meth)acrylate, 3-pentyl (meth)acrylate, 2,2-dimethylbutyl (meth)acrylate, n-hexyl (meth)acrylate, cetyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 4-methyl-2-propylpentyl (meth)acrylate, and n-octadecyl (meth)acrylate. These (meth)acrylates may be used alone or in combination of two or more.

As the photopolymerization initiator, a photopolymerization initiator well known in the industry can be used in a blending amount well known in the industry, so a detailed explanation will be omitted.

The tensile modulus of the adhesive layer can be adjusted to a desired value by adjusting the types, amounts, etc. of the curing component and photopolymerization initiator.

The thickness of the adhesive layer (after curing) is typically 0.1 μm to 5 μm, preferably 0.2 μm to 4 μm, and more preferably 0.3 μm to 3 μm.

A-7. Hard Coat Layer The hard coat layer 70 is typically formed by applying a hard coat layer forming composition containing a curing component and a photopolymerization initiator to the second main surface side of the first retardation layer and curing the composition. It can be formed by

A typical example of the curing component is active energy ray-curable (meth)acrylate. Examples of active energy ray-curable (meth)acrylates include ultraviolet ray-curable (meth)acrylates and electron beam-curable (meth)acrylates. Preferably, it is an ultraviolet curable (meth)acrylate. This is because the hard coat layer can be efficiently formed through simple processing operations.

UV-curable (meth)acrylates include UV-curable monomers, oligomers, polymers, etc. The ultraviolet curable (meth)acrylate contains a monomer component and an oligomer component having preferably two or more, more preferably three to six, ultraviolet polymerizable functional groups. Specific examples of ultraviolet curable (meth)acrylates include urethane acrylate, pentaerythritol triacrylate, ethoxylated glycerin triacrylate, and polyether urethane diacrylate. In addition to these, the curing components of the active energy ray-curable adhesive described in Section A-6 may also be used. The curing components may be used alone or in combination of two or more. The curing method may be a radical polymerization method or a cationic polymerization method. In one embodiment, an organic-inorganic hybrid material in which silica particles, a polysilsesquioxane compound, etc. are blended with (meth)acrylate may be used. Constituent materials and forming methods of the hard coat layer are described in, for example, JP-A No. 2011-237789, JP-A No. 2020-064236, and JP-A No. 2010-152331. The descriptions of these publications are incorporated herein by reference.

The tensile modulus of the hard coat layer can be adjusted to a desired value by adjusting the types, amounts, etc. of the curing component and photopolymerization initiator.

The thickness of the hard coat layer is, for example, 0.1 μm to 5 μm, preferably 0.2 μm to 4 μm, more preferably 0.3 μm to 3 μm.

A-8. Adjacent Layer As described above, the adjacent layer is a layer adjacent to the first retardation layer 30 so as to be in direct contact with the second main surface 100b side. In one embodiment, the adjacent layer is an adhesive layer 40 provided for bonding the first retardation layer 30 and the second retardation layer 50 together. In another embodiment, the adjacent layer is a hard coat layer formed on the second main surface 100b side surface of the first retardation layer 30.

The tensile modulus of the adjacent layer at 110°C is 1 MPa or more, typically 10 MPa or more, preferably 20 MPa or more, more preferably 20 MPa to 100 GPa, and even more preferably 20 MPa to 10 GPa. By providing a layer having such a tensile modulus in close contact with the first retardation layer, it is possible to contribute to suppressing thermal shrinkage of the first retardation layer under high temperature and high humidity conditions. As a result, generation of cracks in the first retardation layer is suppressed, and leakage of iodine and antistatic agent to the image display panel can also be suppressed.

The tensile modulus of the adjacent layer at 23° C. is preferably 10 MPa or more, more preferably 20 MPa or more, and even more preferably 20 MPa to 100 GPa. By providing a layer having such a tensile modulus in close contact with the first retardation layer, it is possible to contribute to suppressing thermal shrinkage of the first retardation layer under high temperature and high humidity conditions. As a result, generation of cracks in the first retardation layer is suppressed, and leakage of iodine and antistatic agent to the image display panel can also be suppressed.

A-9. Release Liner Examples of release liners include flexible plastic films. Examples of the plastic film include polyethylene terephthalate film, polyethylene film, polypropylene film, and polyester film. The thickness of the release liner is, for example, 3 μm or more and, for example, 200 μm or less. The surface of the release liner is coated with a release agent. Specific examples of the release agent include silicone release agents, fluorine release agents, and long-chain alkyl acrylate release agents.

B. Method for manufacturing a polarizing plate with a retardation layer The polarizing plate with a retardation layer described in section A is manufactured by: (Step 1) bonding a polarizing plate and a first retardation layer via a first adhesive layer; 2) bonding the first retardation layer and the second retardation layer via an adhesive layer, and (step 3) forming a second retardation layer on the side opposite to the first retardation layer of the second retardation layer. It can be manufactured by a manufacturing method including providing two adhesive layers. The order of steps 1 to 3 is not particularly limited. For example, a first retardation layer and a second retardation layer are bonded together via an adhesive layer to produce a laminate (step 2), and the laminate is It can be bonded to a polarizing plate via the first adhesive layer (step 1), and a second adhesive layer can be laminated on the polarizing plate with a retardation layer obtained thereby (step 3). The adhesive layer can be formed by applying an adhesive to one of the adherends, laminating the other adherend on the coating layer, and then irradiating the adhesive with active energy rays. Irradiation conditions can be appropriately set depending on the composition of the adhesive, the purpose, etc.

C. Image display device The polarizing plate with a retardation layer described in section A can be applied to an image display device. Therefore, embodiments of the present invention also include image display devices having such a polarizing plate with a retardation layer. Typical examples of image display devices include liquid crystal display devices and organic EL display devices. The image display device according to the embodiment of the present invention includes, for example, as shown in FIG. A polarizing plate 100 with a retardation layer is provided. At this time, the polarizing plate 100 with a retardation layer is bonded to the image display panel 200 via the second adhesive layer so that the second principal surface 100b faces the image display panel 200 side. Further, the image display panel 200 typically has electrodes (such as a conductive layer including a laminated structure of an Al layer and a Ti layer) for driving a display element or for a touch sensor on its surface and/or inside. include. In one embodiment, the change in resistivity of the electrode after holding the image display device under conditions of 110° C. and 85% RH for 36 hours (resistivity after holding/resistivity before holding) is 2 or less, preferably It is 1.8 or less, more preferably 1.5 or less, and still more preferably 1.2 or less.

Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited to these Examples. Unless otherwise specified, "parts" and "%" in Examples and Comparative Examples are based on weight.

<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”).
<Tensile modulus>
A tensile test was conducted at 23°C or 110°C in accordance with JIS K 7127, and the tensile modulus was calculated from linear regression of the resulting stress-strain curve. For the tensile test, a sample for measurement was prepared by cutting an adhesive layer formed to a thickness of 1 mm into a strip shape of 10 mm in width, and 20 mm of each end of the sample for measurement was sandwiched between the chucks of a universal tensile tester. The test was carried out under the conditions that the distance between the chucks was 60 mm and the pulling speed was 150 mm/min.
<Storage modulus>
Dynamic viscoelasticity was measured using Rheometric Scientific's "Advanced Rheometric Expansion System (ARES)" using a measurement sample made by laminating multiple adhesive layers to a thickness of approximately 1.5 mm under the following conditions. From the measurement results, the storage modulus at 23°C or 110°C was read.
(Measurement condition)
Deformation mode: Torsion Measurement frequency: 1Hz
Heating rate: 5°C/min Measurement temperature: -50 to 150°C Shape: Parallel plate 8.0mmφ
<Surface resistivity>
Of the first adhesive layer and second adhesive layer used to produce the polarizing plate with a retardation layer, the adhesive layer containing an antistatic agent was stored indoors in the state of a laminate of [release liner/adhesive layer]. After leaving it for 1 minute at a temperature of 25±5° C. and a relative humidity of 50±10%, its surface resistivity was measured using a high resistance resistivity meter (Hiresta MCP-HT450, manufactured by Mitsubishi Chemical Analytech). In addition, regarding Comparative Example 2, surface resistivity was measured in the same manner as above for both the first adhesive layer and the second adhesive layer. The upper limit of surface resistivity measurement was 1×10 ¹⁴ Ω/□.

[Production Example 1: Polarizing plate]
As the thermoplastic resin base material, a long, amorphous isophthalic copolymerized polyethylene terephthalate film (thickness: 100 μm) having a Tg of approximately 75° C. was used, and one side of the resin base material was subjected to corona treatment.
100 parts by weight of a PVA resin prepared by mixing polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Nippon Gosei Kagaku Kogyo Co., Ltd., trade name "Gosefaimer") at a ratio of 9:1. to which 13 parts by weight of potassium iodide was added was dissolved in water to prepare a PVA aqueous solution (coating solution).
The PVA aqueous solution was applied to the corona-treated surface of the resin base material and dried at 60° C. to form a PVA-based resin layer with a thickness of 13 μm, thereby producing a laminate.
The obtained laminate was uniaxially stretched 2.4 times in the vertical direction (longitudinal direction) in an oven at 130° C. (in-air auxiliary stretching treatment).
Next, the laminate was immersed for 30 seconds in an insolubilization bath (boric acid aqueous solution obtained by blending 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40° C. (insolubilization treatment).
Next, the final polarizer was added to a dyeing bath (an aqueous iodine solution obtained by blending iodine and potassium iodide at a weight ratio of 1:7 to 100 parts by weight of water) at a liquid temperature of 30°C. The sample was immersed for 60 seconds while adjusting the concentration so that the single transmittance (Ts) became a desired value (staining treatment).
Next, it was immersed for 30 seconds in a crosslinking bath (an aqueous boric acid solution obtained by blending 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 40°C. (Crosslinking treatment).
Thereafter, while immersing the laminate in a boric acid aqueous solution (boric acid concentration: 4% by weight, potassium iodide concentration: 5% by weight) at a liquid temperature of 70°C, the laminate was completely rolled in the longitudinal direction (longitudinal direction) between rolls having different circumferential speeds. Uniaxial stretching was performed so that the stretching ratio was 5.5 times (underwater stretching treatment).
Thereafter, the laminate was immersed in a cleaning bath (an aqueous solution obtained by blending 4 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 20° C. (cleaning treatment).
Thereafter, while drying in an oven kept at about 90°C, it was brought into contact with a SUS heating roll whose surface temperature was kept at about 75°C (drying shrinkage treatment).
In this way, a polarizer with a thickness of about 5 μm was formed on the resin base material.
An HC-TAC film (first protective layer) was attached as a protective layer to the surface of the obtained polarizer (the surface opposite to the resin base material) via an ultraviolet curable adhesive. Specifically, the curable adhesive was applied to a thickness of 1.0 μm and bonded together using a roll machine. Thereafter, the adhesive was cured by irradiating UV light from the protective layer side. The HC-TAC film is a film in which a hard coat (HC) layer (7 μm thick) is formed on a triacetyl cellulose (TAC) film (25 μm thick), and is pasted with the TAC film facing the polarizer. Combined.
Methyl methacrylate (MMA, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name "Methyl methacrylate monomer") 97.0 parts, 3.0 parts of copolymerization monomer represented by the following formula (1e), polymerization initiator (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd., trade name: "2,2'-Azobis(isobutyronitrile)") 0.2 parts was dissolved in 200 parts of toluene. Next, a polymerization reaction was carried out for 5.5 hours while heating at 70° C. in a nitrogen atmosphere to obtain a boron-containing acrylic resin solution (solid content concentration: 33%). The obtained boron-containing acrylic polymer had a Tg of 110°C and a Mw of 80,000. 20 parts of the obtained boron-containing acrylic resin was dissolved in 80 parts of methyl ethyl ketone to obtain a resin solution (20%).
After peeling off the resin base material from the above polarizer and applying a resin solution to the peeled surface using a wire bar, the coated film was dried at 60°C for 5 minutes, and the coated film of the organic solvent solution of the resin was solidified. A second protective layer (thickness: 400 nm) was formed. Thereby, a polarizing plate having the structure of [HC layer-attached TAC film (first protective layer)/polarizer/solidified layer of boron-containing acrylic resin (second protective layer)] was obtained.

[Production Example 2: First retardation layer]
29.60 weight of bis[9-(2-phenoxycarbonylethyl)fluoren-9-yl]methane was added to a batch polymerization apparatus consisting of two vertical reactors equipped with a stirring blade and a reflux condenser controlled at 100°C. part (0.046 mol), isosorbide (ISB) 29.21 parts by weight (0.200 mol), spiroglycol (SPG) 42.28 parts by weight (0.139 mol), diphenyl carbonate (DPC) 63.77 parts by weight (0 .298 mol) and 1.19×10 ⁻² parts by weight (6.78×10 ⁻⁵ mol) of calcium acetate monohydrate as a catalyst were charged. 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 the predetermined power is reached, nitrogen is introduced into the reactor to restore the pressure, and after melting and kneading 0.7 parts by mass of PMMA to 100 parts by weight of the produced polyester carbonate-based resin, it is extruded into water and the strands are cut. to obtain pellets.
The obtained polyester carbonate resin (pellet) was vacuum-dried at 80°C for 5 hours, and then placed in 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). ), a film forming apparatus equipped with a chill roll (set temperature: 120 to 130°C) and a winder, a long resin film with a thickness of 105 μm was produced. The obtained elongated resin film was stretched 2.8 times in the width direction at 138° C. while adjusting to obtain a predetermined retardation to obtain a retardation film with a thickness of 38 μm. Re(550) of the obtained retardation film was 144 nm, and Re(450)/Re(550) was 0.86.

[Manufacturing Example 3: Second retardation layer]
20 parts by weight of a side chain type liquid crystal polymer represented by the following chemical formula (3) (numbers 65 and 35 in the formula indicate mol% of monomer units, and are conveniently expressed as a block polymer body: 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 liquid crystal alignment solidified layer (thickness: 3 μm) exhibiting a refractive index characteristic of nz>nx=ny was formed on the base material.

[Manufacturing Example 4A: Adhesive]
5 parts by weight of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM-303"), 35 parts by weight of 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) ), 24 parts by weight of neopentyl glycol diacrylate (manufactured by Kyoeisha Kagaku Co., Ltd., trade name "Light Acrylate NP-A"), 10 parts by weight of isocyanuric acid EO-modified triacrylate (manufactured by Toagosei Co., Ltd., trade name "Aronix M-") 315"), 5 parts by weight of pentaerythritol triacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., trade name "A-TMM-3LM-N"), 15 parts by weight of polyurethane-based acrylic oligomer (manufactured by Mitsubishi Chemical Co., Ltd., trade name "UV3000B") ), 3 parts by weight of a photopolymerization initiator (manufactured by IGM Resins, trade name: "Omnirad 184"), 2 parts by weight of a photopolymerization initiator (manufactured by Sun-Apro, trade name: "CPI-100P"), and 1 part by weight of boric acid (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) was mixed and stirred for 3 hours to obtain active energy ray-curable adhesive 4A.

[Manufacturing Example 4B: Adhesive]
20 parts by weight of acryloylmorpholine (manufactured by Kojinsha, trade name: ACMO), 50 parts by weight of unsaturated fatty acid hydroxyalkyl ester modified ε-caprolactone (manufactured by Daicel, trade name: Plaxel FA1DDM), 10 parts by weight of PEG400# Diacrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Light Acrylate 9EG-A), 34/66 molar ratio copolymer oligomer of butyl acrylate and methacrylate (manufactured by Toagosei Co., Ltd., trade name: ARUFON UP-1190) , 3 parts by weight of 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (photopolymerization initiator) (manufactured by IGM Resins, trade name "Omnirad 907"), and 2 parts by weight Active energy ray-curable adhesive 4B was obtained by mixing diethylthioxanthone (photopolymerization initiator) (manufactured by Nippon Kayaku Co., Ltd., trade name: KAYACURE DETX-S) and stirring for 3 hours.

[Production Examples 5A-5H: Adhesive layer]
1. Synthesis of (meth)acrylic polymer A four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with monomer components having the composition shown in Table 1, and then polymerization was started. After adding the agent and replacing the inside of the flask with nitrogen by introducing nitrogen gas while stirring gently, the polymerization reaction was allowed to proceed for 7 hours while maintaining the liquid temperature in the flask at around 55°C. Next, ethyl acetate was added to the obtained reaction solution to adjust the solid content concentration to 12% by weight to obtain solutions of (meth)acrylic polymers 5A to 5H.

2. Preparation of Adhesive Add a crosslinking agent and, if necessary, a solution of (meth)acrylic polymers 5A to 5H so that the amount of the (meth)acrylic polymer based on 100 parts by weight of the solid content is as shown in Table 2. Then, a silane coupling agent and/or an antistatic agent were mixed to obtain adhesives 5A to 5H. In the table, LiTFSi is lithium bis(trifluoromethanesulfonyl)imide, EMP-TFSi is ethylmethylpyrrolidinium bis(trifluoromethanesulfonyl)imide, and TBMA-TFSi is tributylmethylammonium bis(trifluoromethanesulfonyl)imide. ) imide and MOPy-PF6 is methyloctylpyridinium hexafluorophosphate.

3. Formation of Adhesive Layer Adhesives 5A to 5H were applied to the release surface of a 38 μm thick PET film (manufactured by Mitsubishi Chemical Polyester Film Co., Ltd., MRF38), which is a release liner whose release surface was treated with silicone. Thereafter, it was dried in an air circulating constant temperature oven set at a predetermined temperature to form adhesive layers 5A to 5H having a predetermined thickness.

[Example 1]
The adhesive layer 5A (thickness: 5 μm) obtained in Production Example 5A was transferred from a release liner onto the surface of the second protective layer of the polarizing plate obtained in Production Example 1, and the adhesive layer 5A obtained in Production Example 2 was transferred via the adhesive layer 5A. The first retardation layer was bonded to a polarizing plate to obtain a laminate. At this time, the slow axis of the first retardation layer was arranged at an angle of 45° with respect to the absorption axis of the polarizer.
The active energy ray-curable adhesive obtained in Production Example 4A was applied to one side of the second retardation layer obtained in Production Example 3 using an MCD coater (manufactured by Fuji Kikai Co., Ltd.) so that the thickness after curing would be 1 μm. It was applied onto the surface of the first retardation layer of the laminate using a roll machine. Thereafter, the adhesive was cured by irradiating ultraviolet rays from the second retardation layer side using an active energy ray irradiation device at a cumulative light amount of 4500 mJ/cm ² , and then dried with hot air at 70° C. for 3 minutes.
The adhesive layer 5E (thickness: 20 μm) obtained in Production Example 5E was transferred from the release liner to the surface of the second retardation layer of the laminate obtained as described above, and [Polarizing plate/first adhesive layer (adhesive Polarizing plate with a retardation layer having the following configuration: layer 5A)/first retardation layer/adhesive layer (cured layer of adhesive 4A)/second retardation layer/second adhesive layer (adhesive layer 5E)] I got it.

[Examples 2 to 4, Comparative Examples 1 to 5]
In Examples 2 to 4 and Comparative Examples 3 to 5, polarizing plates with retardation layers were prepared in the same manner as in Example 1 except that the first adhesive layer and the second adhesive layer were changed as shown in Table 3. I got it.
Furthermore, in Comparative Examples 1 and 2, the first adhesive layer, the adhesive layer, and the second adhesive layer were changed as shown in Table 3, and the first retardation layer was bonded to the polarizing plate. Thereafter, a polarizing plate with a retardation layer was obtained in the same manner as in Example 1 except that the adhesive shown in Production Example 4B was applied to the surface of the first retardation layer and then the second retardation layer was attached. . An ultrathin section was prepared from the obtained polarizing plate with a retardation layer, and TEM observation revealed that a compatible region with a thickness of about 100 nm was formed on the adhesive layer side of the first retardation layer. The compatible region can be formed by the acrylic monomer shown in the adhesive shown in Production Example 4B, especially acryloylmorpholine (manufactured by Kojinsha, trade name: ACMO).

The following characteristics were evaluated for the polarizing plates with retardation layers obtained in Examples and Comparative Examples.
1. Resistivity of sensor electrode in wet heat test A test specimen was prepared for evaluating the resistivity of a touch sensor electrode assuming a touch panel. Specifically, an Al vapor-deposited film (manufactured by Toray Industries, product number "DMS-X42G"), in which an aluminum vapor-deposited layer (thickness: 0.05 μm) was provided on one side of a PET resin film (thickness: 50 μm), was 70 mm long and wide. A 150 mm piece was cut out and the PET resin film surface was bonded to a glass plate via an acrylic adhesive layer to prepare a glass plate with an Al vapor deposited layer having a configuration of [aluminum vapor deposited layer/resin film/glass plate]. The polarizing plate with a retardation layer produced in Examples and Comparative Examples was cut out to a length of 70 mm and a width of 150 mm, and a second plate was cut out onto the aluminum vapor-deposited layer surface of the glass plate with an Al vapor-deposited layer, with the ends in the length direction and width direction aligned. They were laminated via an adhesive layer. Thereby, a test specimen for resistivity evaluation was obtained. The test specimen was left in a heated and humidified atmosphere at a temperature of 110° C. and a relative humidity of 85% for 36 hours. Next, the test specimen was returned to an atmosphere with a temperature of 25°C and a relative humidity of 50%, and the surface resistivity (Ω/□) of the aluminum vapor-deposited layer was measured using Napson's EC-80 (non-contact resistance measuring device). did. The value obtained by dividing the surface resistivity after the wet heat test by the surface resistivity before the test is shown in Table 3 as "sensor electrode resistivity change".

2. Cracks in moist heat test The polarizing plates with retardation layers obtained in Examples and Comparative Examples were cut into a size of 7 cm width x 15 cm length. The cut out polarizing plate with a retardation layer is attached to a glass plate via a second adhesive layer, and a glass plate is also attached to the polarizing plate side via an acrylic adhesive. A test sample having a structure of "layered polarizing plate/glass plate" was prepared.
A test sample was subjected to a heat-and-moisture test in which it was left standing in an atmosphere at a temperature of 110° C. and a relative humidity of 85% for 36 hours.
The test sample after the moist heat test was observed under a microscope and evaluated based on the following criteria. The results are shown in Table 3.
○: A crack that penetrates the first retardation layer in the thickness direction does not occur. ×: A crack that penetrates the first retardation layer in the thickness direction.

As shown in Table 3, the polarizing plate with a retardation layer of the example was able to suppress the adverse effects on the image display panel under high temperature and high humidity conditions while maintaining a practically sufficient antistatic function. On the other hand, the polarizing plates with retardation layers of Comparative Examples 1 and 2 had a large change in sensor electrode resistivity after the wet heat test. This is because the tensile modulus at 110°C is less than 1 MPa, as is clear from the fact that the adhesive layer, which is the layer adjacent to the first retardation layer, has a tensile modulus of 2.6 × 10 ⁶ Pa at 23°C. As a result, cracks in the first retardation layer could not be sufficiently suppressed, and it is presumed that iodine or the antistatic agent leaked out. Furthermore, in the polarizing plates with retardation layers of Comparative Examples 3 to 5, the sensor electrode resistivity change after the wet heat test was greater than 2, but this was due to the antistatic agent contained in the adhesive layer. It is presumed that this is due to corrosion of the layer (Al layer).

The laminate according to the embodiment of the present invention can be used, for example, to manufacture a polarizing plate with a retardation layer used in an image display device. Typical image display devices include liquid crystal display devices, organic EL display devices, and inorganic EL display devices.

10 Polarizing plate 12 Polarizer 14 Protective layer 20 First adhesive layer 30 First retardation layer 40 Adhesive layer 50 Second retardation layer 60 Second adhesive layer 70 Hard coat layer 100 Polarizing plate with retardation layer 200 Image Display panel 300 Image display device

Claims

having a first main surface and a second main surface facing each other,
From the first main surface toward the second main surface, a polarizing plate including a polarizer, a first adhesive layer, a first retardation layer, an adhesive layer, a second retardation layer, and a second retardation layer are arranged. 2 adhesive layers in this order,
A polarizing plate with a retardation layer, comprising an adhesive layer containing an antistatic agent,
The tensile modulus at 110° C. of the adjacent layer adjacent to the second main surface side of the first retardation layer is 1 MPa or more,
The amount of the antistatic agent added in the adhesive layer containing the antistatic agent is 5 phr or less,
The polarizing plate with a retardation layer is formed by applying the second adhesive layer to the surface of the aluminum layer of a laminate including a polyethylene terephthalate resin film having a thickness of 50 μm and an aluminum layer having a thickness of 0.05 μm provided on one surface thereof. The change in resistivity of the aluminum layer after being held for 36 hours at 110° C. and 85% RH is 2 or less when bonded through the aluminum layer.
Polarizing plate with retardation layer.
The first retardation layer is a stretched film of a resin film,
Re(550) of the first retardation layer is 100 nm to 190 nm, Re(450)/Re(550) is 0.8 or more and less than 1,
The polarizing plate with a retardation layer according to claim 1, wherein the angle between the slow axis of the first retardation layer and the absorption axis of the polarizer is 40° to 50°.
The polarizing plate with a retardation layer according to claim 1, wherein the first retardation layer has a thickness of 10 μm or more.
The polarizing plate with a retardation layer according to claim 2, wherein the second retardation layer exhibits a refractive index characteristic of nz>nx=ny.
The polarizing plate with a retardation layer according to claim 1, wherein the first adhesive layer and/or the second adhesive layer has a surface resistivity of 9×10 11 Ω/□ or less.
The polarizing plate with a retardation layer according to claim 1, wherein the antistatic agent contains an ionic compound containing bistrifluoromethanesulfonylimide as an anion.
The polarizing plate with a retardation layer according to claim 1, wherein the adjacent layer is the adhesive layer.
The polarizing plate with a retardation layer according to claim 1, wherein the adjacent layer is a hard coat layer formed directly on the second main surface side surface of the first retardation layer.
An image display device comprising an image display panel and the polarizing plate with a retardation layer according to any one of claims 1 to 8 arranged on the viewing side of the image display panel.
the image display panel includes electrodes,
The image display device according to claim 9, wherein the change in resistivity of the electrode after being held for 36 hours under conditions of 110° C. and 85% RH is 2 or less.