Protective film, polarizing plate, method for manufacturing a polarizing plate, and method for manufacturing an image display device.

Abstract

To suppress the deformation of the polarizing plate. [Solution] The protective film according to an embodiment of the present invention comprises a base film having a first main surface and a second main surface facing each other, and an adhesive layer disposed on the first main surface side of the base film, wherein the peel force to an adherend with a water contact angle of 90° or more is 0.03 N / 25 mm or more, and the in-plane shear force to the adherend is 35 N / 100 mm 2 The following applies:

Description

[Technical Field]

[0001] The present invention relates to a protective film, a polarizing plate, a method for manufacturing a polarizing plate, and a method for manufacturing an image display device. [Background technology]

[0002] Image display devices, such as liquid crystal displays and electroluminescent (EL) displays (e.g., organic EL displays and inorganic EL displays), are rapidly becoming widespread. Polarizing plates are generally used in the image display panels mounted on image display devices. Typically, polarizing plates with a phase difference layer, which integrate a polarizing plate and a phase difference plate, are widely used (e.g., Patent Document 1).

[0003] The above polarizing plate is typically obtained by laminating a polarizer having a polarizing function with a protective member. Similarly, the above image display panel is typically obtained by bonding a polarizing plate to the image display panel body. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Patent No. 3325560 [Overview of the project] [Problems that the invention aims to solve]

[0005] During the manufacturing process of the polarizing plates and image display devices described above, the polarizing plates may deform due to handling, resulting in damage to their appearance. For example, indentations may be left on the polarizing plates due to handling.

[0006] In view of the above, the main objective of the present invention is to suppress deformation of the polarizing plate during the manufacturing process. [Means for solving the problem]

[0007] According to an embodiment of the present invention, a protective film is provided. This protective film comprises a base film having a first main surface and a second main surface facing each other, and an adhesive layer disposed on the first main surface side of the base film, wherein the peel force to an adherend with a water contact angle of 90° or more is 0.03 N / 25 mm or more, and the in-plane shear force to the adherend is 35 N / 100 mm 2 The following applies: In one embodiment, the thickness of the adhesive layer exceeds 10 μm. In one embodiment, the adhesive layer comprises an acrylic adhesive, the acrylic adhesive comprises a (meth)acrylic polymer having polar functional groups, and the content of the monomer component having polar functional groups is 2 parts by weight or more per 100 parts by weight of the monomer forming the (meth)acrylic polymer. According to another embodiment of the present invention, a polarizing plate is provided. This polarizing plate comprises the protective film, a laminated film having a substrate and a surface treatment layer having a water contact angle of 90° or more, and a polarizer, wherein the protective film is bonded to the surface treatment layer. A further embodiment of the present invention provides a method for manufacturing a polarizing plate. This method for manufacturing a polarizing plate includes laminating a protective film to the surface treatment layer of a laminated film having a substrate and a surface treatment layer having a water contact angle of 90° or more, and laminating a polarizer on the substrate side of the laminated film. According to yet another embodiment of the present invention, a method for manufacturing an image display device is provided. This method for manufacturing an image display device includes laminating a polarizing plate obtained by the above manufacturing method onto an image display panel body. [Effects of the Invention]

[0008] According to embodiments of the present invention, the occurrence of deformation of the polarizing plate can be suppressed. [Brief explanation of the drawing]

[0009] [Figure 1A] This figure shows the manufacturing process 1 of a polarizing plate according to one embodiment of the present invention. [Figure 1B]It is a diagram showing Step 2 following the above Step 1. [Figure 1C] It is a diagram showing Step 3 following the above Step 2. [Figure 2] It is a schematic cross-sectional view showing a modified example of a polarizing plate. [Figure 3] In an organic EL display device according to one embodiment of the present invention, it is a schematic cross-sectional view showing an outline of a state where a polarizing plate is disposed on an organic EL panel. [Figure 4] It is a diagram for explaining a method of measuring a shearing force. [Figure 5] It is a diagram for explaining a method of evaluating deformation. [Embodiments for Carrying Out the Invention]

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. Also, in order to make the description clearer, the drawings may schematically show the width, thickness, shape, etc. of each part as compared with the embodiments, but this is merely an example and does not limit the interpretation of the present invention.

[0011] (Definitions of Terms and Symbols) The definitions of terms and symbols in this specification are as follows. (1) Refractive Index (nx, ny, nz) "nx" is the refractive index in the direction where the in-plane refractive index is maximum (i.e., the slow axis direction), "ny" is the refractive index in the direction orthogonal to the slow axis in the plane (i.e., the fast axis direction), and "nz" is the refractive index in the thickness direction. (2) In-Plane Phase Difference (Re) "Re(λ)" is the in-plane phase difference measured with light of wavelength λ nm at 23°C. For example, "Re(550)" is the in-plane phase difference measured with light of wavelength 550 nm at 23°C. Re(λ) is obtained by the formula: Re(λ) = (nx - ny) × d when the thickness of the layer (film) is d (nm). (3) Phase Difference in the Thickness Direction (Rth) "Rth(λ)" is the phase difference in the thickness direction measured with light of wavelength λnm at 23°C. For example, "Rth(550)" is the phase difference in the thickness direction measured with light of wavelength 550nm at 23°C. Rth(λ) can be calculated using the formula: Rth(λ) = (nx - nz) × d, where d (nm) is the thickness of the layer (film). (4) Nz coefficient The Nz coefficient is calculated using the formula Nz = Rth / Re.

[0012] A method for manufacturing a polarizing plate according to one embodiment of the present invention includes laminating a protective film onto the surface treatment layer of a laminated film having a substrate and a surface treatment layer, and laminating a polarizer on the substrate side of the laminated film.

[0013] Figures 1A to 1C show the manufacturing process of a polarizing plate according to one embodiment of the present invention.

[0014] Figure 1A, showing step 1, shows the completed laminate 90, which is formed by laminating a polarizer 30 onto the base material 21 side of a laminated film 20 having a base material 21 and a surface treatment layer 22, and then laminating a protective layer 40 onto the polarizer 30. The laminate 90 has the laminated film 20, the polarizer 30, and the protective layer 40 in this order. The base material 21 of the laminated film 20 can function as a protective layer for the polarizer 30. The protective layer 40 may function as a phase difference layer (for example, a λ / 4 plate). The laminate 90 is typically elongated and can be wound into a roll. Here, "elongated" refers to an elongated shape in which the length is sufficiently long relative to the width, for example, an elongated shape in which the length is 10 times or more, preferably 20 times or more, relative to the width.

[0015] Figure 1B, showing step 2, illustrates the completed polarizing plate 100 after forming the adhesive layer 50 on the protective layer 40 side of the laminate 90. Although not shown, a release liner is practically bonded to the surface of the adhesive layer 50. Using a release liner protects the adhesive layer 50 and enables the formation of the polarizing plate in roll form.

[0016] Figure 1C, showing step 3, illustrates the state in which the protective film 10 has been attached to the surface treatment layer 22 of the laminated film 20 of the polarizing plate 100. Hereinafter, the state in which the protective film (10) has been attached may be referred to as the protective film-attached polarizing plate (110).

[0017] The protective film 10 comprises a base film 11 having a first main surface 11a and a second main surface 11b facing each other, an adhesive layer 12 disposed on the first main surface 11a side of the base film 11, and a processing layer 13 disposed on the second main surface 11b side of the base film 11. The protective film 10 is laminated to the laminated film 20, for example, by conveying them on a roll (so-called roll-to-roll).

[0018] The protective film 10 is peelably bonded to the laminated film 20. The protective film 10 may be peeled off before the polarizing plate obtained according to the embodiment of the present invention is put into use (for example, before it is laminated onto the image display panel body), or during the manufacturing process of the final product (image display device), or it may be mounted on the final product as is.

[0019] The stacking order of the components constituting the polarizing plate (polarizing plate with protective film) is not particularly limited. For example, in the illustrated example, the protective film 10 is attached to the laminated film 20 after the laminated film 20 and the polarizer 30 have been stacked, but the laminated film 20 and the polarizer 30 may be stacked after the protective film 10 has been attached to the laminated film 20.

[0020] In the illustrated example, the polarizing plate 100 has a protective layer 40 and an adhesive layer 50 in addition to the laminated film 20 and polarizer 30, but the polarizing plate 100 only needs to have at least the laminated film 20 and polarizer 30. On the other hand, although not shown, the polarizing plate 100 may have other components. In the example shown in Figure 2, the polarizing plate 100 (polarizing plate with protective film 110) further has a phase difference layer (e.g., a λ / 4 plate) 60 and an adhesive layer 52 in addition to the configuration shown in Figure 1C. Although not shown, a release liner is practically bonded to the surface of the adhesive layer 52.

[0021] Each of the above components can be laminated via any suitable adhesive layer. Specific examples of adhesive layers include adhesive layers and tack layers. For example, the polarizer and the protective layer are bonded together via an adhesive layer. Specifically, the polarizer and the protective layer are bonded together using an active energy ray curable adhesive. The thickness of the active energy ray curable adhesive after curing (thickness of the adhesive layer) is, for example, 0.2 μm to 3.0 μm, preferably 0.4 μm to 2.0 μm, and more preferably 0.6 μm to 1.5 μm.

[0022] [polarizer] The polarizer described above is typically a resin film containing a dichroic substance (e.g., iodine). Examples of resin films include hydrophilic polymer films such as polyvinyl alcohol (PVA) films, partially formalized PVA films, and partially saponified ethylene-vinyl acetate copolymer films.

[0023] 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.

[0024] The polarizer preferably exhibits absorption dichroism at any wavelength between 380 nm and 780 nm. The 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 higher, more preferably 99.0% or higher, and even more preferably 99.9% or higher.

[0025] Polarizers can be fabricated by any suitable method. Specifically, polarizers may be fabricated from a single layer of resin film, or from a laminate of two or more layers.

[0026] The method for producing polarizers from the single-layer resin film described above typically involves dyeing the resin film with a dichroic substance such as iodine or a dichroic dye, and then stretching it. Examples of hydrophilic polymer films used as resin films include polyvinyl alcohol (PVA) films, partially formalized PVA films, and partially saponified ethylene-vinyl acetate copolymer films. This method may further include insolubilization, swelling, and crosslinking treatments. Since such manufacturing methods are well-known and commonly used in this industry, a detailed explanation is omitted.

[0027] A polarizer obtained using the above laminate can be manufactured, for example, using a laminate of a resin substrate and a resin film or resin layer (typically a PVA-based resin layer). Specifically, it can be manufactured by applying a PVA-based resin solution to a resin substrate, drying it to form a PVA-based resin layer on the resin substrate, thereby obtaining a laminate of a resin substrate and a PVA-based resin layer; and stretching and dyeing the laminate to make the PVA-based resin layer 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 substrate. Stretching typically includes immersing the laminate in an aqueous boric acid solution and stretching it. Furthermore, stretching may, if necessary, further include air-stretching the laminate at a high temperature (e.g., 95°C or higher) before stretching in the aqueous boric acid solution. In addition, in this embodiment, preferably, the laminate is subjected to a drying shrinkage treatment in which it shrinks by 2% or more in the width direction by heating while being transported in the longitudinal direction. Typically, the manufacturing method of this embodiment involves subjecting the laminate to an air-assisted stretching treatment, a dyeing treatment, a water-assisted stretching treatment, and a drying shrinkage treatment in that order. By introducing auxiliary stretching, it is possible to increase the crystallinity of PVA even when PVA is coated on a thermoplastic resin, thereby achieving high optical properties. At the same time, by increasing the orientation of PVA in advance, problems such as a decrease in the orientation of PVA and dissolution can be prevented when immersed in water during the subsequent dyeing and stretching processes, thereby achieving high optical properties. Furthermore, when the PVA-based resin layer is immersed in a liquid, compared to when the PVA-based resin layer does not contain halides, disorder in the orientation of PVA molecules and a decrease in orientation can be suppressed, thereby achieving high optical properties. Furthermore, by shrinking the laminate in the width direction through the drying shrinkage treatment, high optical properties can be achieved. A polarizing plate can be obtained by laminating a protective layer on the peeled surface obtained by peeling the resin substrate from the obtained resin substrate / polarizer laminate, or on the surface opposite to the peeled surface. Details of the manufacturing method of such polarizers are described, for example, in Japanese Patent Publication No. 2012-73580 and Japanese Patent No. 6470455. The entire contents of these publications are incorporated herein by reference.

[0028] [Protective layer] The protective layer described above can be formed from any suitable film that can be used as a protective layer for a polarizer. Specific examples of materials that make up the main component of the film include cellulosic resins such as triacetylcellulose (TAC), polyester, polyvinyl alcohol, polycarbonate, polyamide, polyimide, polyethersulfone, polysulfone, polystyrene, cycloolefins such as polynorbornene, polyolefins, (meth)acrylic, and acetate resins.

[0029] The thickness of the 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.

[0030] In one embodiment, the protective layer 40, which is positioned on the side of the polarizer 30 where the laminated film 20 is not positioned, is preferably optically isotropic. In this specification, "optically isotropic" means that the in-plane phase difference Re(550) is 0 nm to 10 nm and the phase difference Rth(550) in the thickness direction is -10 nm to +10 nm.

[0031] [Laminated film] The laminated film described above comprises a substrate and a surface treatment layer formed on the substrate. The substrate can function as a protective layer for a polarizer, and its details are as described above. The polarizer obtained according to the embodiment of the present invention is typically placed on the viewing side of an image display device, and the laminated film is also placed on the viewing side. In one embodiment, the surface treatment layer of the laminated film is located on the outermost surface of the image display device. Therefore, it is preferable that the substrate (protective layer on the viewing side) has a surface treatment layer formed on it, such as a hard coat (HC) treatment, anti-reflective treatment, anti-sticking treatment, anti-glare treatment, or anti-fouling treatment.

[0032] In one embodiment, the surface treatment layer has anti-glare and anti-reflective properties. Specifically, the surface treatment layer has an anti-glare layer and an anti-reflective layer in that order from the substrate side. The anti-glare layer typically contains a resin and a filler. Specifically, anti-glare properties are obtained by incorporating a filler into the resin to create a fine uneven surface on the resulting layer (anti-glare layer). By providing an anti-glare layer, for example, on the surface of an image display device, external light such as fluorescent lamps or sunlight can be scattered, suppressing image reflection and preventing a decrease in contrast. The anti-reflective layer can reduce reflection on the surface of the anti-glare layer. The reflectance of the surface treatment layer side of the laminated film is preferably 3% or less, and more preferably 1% or less.

[0033] The anti-reflective layer described above can be obtained, for example, by applying an anti-reflective layer forming coating liquid onto the anti-glare layer and then drying and curing the resulting coating film. The anti-reflective layer forming coating liquid may contain, for example, a resin component (curable compound), a fluorine-containing additive, hollow particles, solid particles, and a solvent, and can be obtained, for example, by mixing these.

[0034] Examples of curing mechanisms for the resin component (curable compound) contained in the anti-reflective coating liquid include thermosetting and photocuring types. Examples of resin components include curable compounds having at least one of an acrylate group and a methacrylate group, such as oligomers or prepolymers of polyfunctional compounds such as silicone resins, polyester resins, polyether resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and polyhydric alcohols, such as acrylates or methacrylates. These may be used individually or in combination of two or more types.

[0035] The above resin component may also be a reactive diluent having at least one of an acrylate group and a methacrylate group. The reactive diluent may be, for example, the reactive diluent described in Japanese Patent Application Publication No. 2008-88309, and includes, for example, monofunctional acrylate, monofunctional methacrylate, polyfunctional acrylate, polyfunctional methacrylate, etc. From the viewpoint of obtaining excellent hardness, a trifunctional or more acrylate or trifunctional or more methacrylate is preferably used as the reactive diluent. Examples of reactive diluents include butanediol glycerin ether diacrylate, isocyanuric acid acrylate, isocyanuric acid methacrylate, etc. These may be used individually or in combination of two or more. For curing the above resin component, a curing agent may be used, for example. As a curing agent, for example, a known polymerization initiator (e.g., a thermal polymerization initiator, a photopolymerization initiator, etc.) can be used.

[0036] The fluorine-containing additive mentioned above may be, for example, an organic compound containing fluorine, or an inorganic compound containing fluorine. Examples of organic compounds containing fluorine include fluorine-containing antifouling coatings, fluorine-containing acrylic compounds, and fluorine-silicon-containing acrylic compounds. Commercially available organic compounds containing fluorine can be used. Specific examples of commercially available products include "KY-1203" manufactured by Shin-Etsu Chemical Co., Ltd., and "Megafac" manufactured by DIC Corporation. The amount of the fluorine-containing additive may be, for example, 0.05 parts by weight or more, 0.1 parts by weight or more, 0.15 parts by weight or more, 0.20 parts by weight or more, or 0.25 parts by weight or more per 100 parts by weight of the resin component, or it may be 20 parts by weight or less, 15 parts by weight or less, 10 parts by weight or less, 5 parts by weight or less, or 3 parts by weight or less.

[0037] Examples of hollow particles used include silica particles, acrylic particles, and acrylic-styrene copolymer particles. Commercially available hollow silica particles (for example, "Thru-Ria 5320" and "Thru-Ria 4320" manufactured by JGC Catalysts & Chemicals Co., Ltd.) can be used. The weight-average particle diameter of the hollow particles may be, for example, 30 nm or more, 40 nm or more, 50 nm or more, 60 nm or more, or 70 nm or more, and may also be 150 nm or less, 140 nm or less, 130 nm or less, 120 nm or less, or 110 nm or less. The shape of the hollow particles is not particularly limited, but is preferably approximately spherical. Specifically, the aspect ratio of the hollow particles is preferably 1.5 or less. The content of hollow particles may be, for example, 30 parts by weight or more, 50 parts by weight or more, 70 parts by weight or more, 90 parts by weight or more, or 100 parts by weight or more per 100 parts by weight of the above resin component, or it may be 300 parts by weight or less, 270 parts by weight or less, 250 parts by weight or less, 200 parts by weight or less, or 180 parts by weight or less.

[0038] Examples of solid particles used include silica particles, zirconia particles, and titania particles. Commercially available solid silica particles (for example, Nissan Chemical Industries, Ltd.'s product names "MEK-2140Z-AC", "MIBK-ST", and "IPA-ST") can be used. The weight-average particle diameter of the solid particles may be, for example, 5 nm or more, 10 nm or more, 15 nm or more, 20 nm or more, or 25 nm or more, and may also be 330 nm or less, 250 nm or less, 200 nm or less, 150 nm or less, or 100 nm or less. The shape of the hollow particles is not particularly limited, but is preferably approximately spherical. Specifically, the aspect ratio of the hollow particles is preferably 1.5 or less. The content of solid particles may be, for example, 5 parts by weight or more, 10 parts by weight or more, 15 parts by weight or more, 20 parts by weight or more, or 25 parts by weight or more per 100 parts by weight of the resin component, or it may be 150 parts by weight or less, 120 parts by weight or less, 100 parts by weight or less, or 80 parts by weight or less.

[0039] Any suitable solvent can be used as the solvent mentioned above. Examples of solvents include alcohols such as methanol, ethanol, isopropyl alcohol, butanol, TBA (tert-butyl alcohol), and 2-methoxyethanol; ketones such as acetone, methyl ethyl ketone, MIBK (methyl isobutyl ketone), and cyclopentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, and PMA (propylene glycol monomethyl ether acetate); ethers such as diisopropyl ether and propylene glycol monomethyl ether; glycols such as ethylene glycol and propylene glycol; cellosolves such as ethyl cellosolve and butyl cellosolve; aliphatic hydrocarbons such as hexane, heptane, and octane; and aromatic hydrocarbons such as benzene, toluene, and xylene. These may be used individually or in combination of two or more. The solvent content may be such that, for example, the weight of the solids relative to the total weight of the anti-reflective coating liquid is, for example, 0.1% by weight or more, 0.3% by weight or more, 0.5% by weight or more, 1.0% by weight or more, or 1.5% by weight or more, or 20% by weight or less, 15% by weight or less, 10% by weight or less, 5% by weight or less, or 3% by weight or less.

[0040] As a coating method for the anti-reflective layer forming coating liquid described above, known coating methods such as the fountain coating method, die coating method, spin coating method, spray coating method, gravure coating method, roll coating method, and bar coating method can be used. The drying temperature of the coating film is, for example, 30°C to 200°C, and the drying time is, for example, 30 seconds to 90 seconds. The coating film can be cured by, for example, heating or light irradiation (typically ultraviolet irradiation). As a light source for light irradiation, for example, a high-pressure mercury lamp can be used. The irradiation dose for ultraviolet irradiation is 50 mJ / cm² as the integrated exposure dose at an ultraviolet wavelength of 365 nm. 2 ~500mJ / cm 2 It is preferable that this be the case.

[0041] Preferably, the surface treatment layer may have antifouling properties. Specifically, the surface treatment layer may contain at least one of fluorine or silicon. On the other hand, such a surface treatment layer may reduce the adhesion to the protective film.

[0042] The thickness of the surface treatment layer is, for example, 1 μm to 20 μm, preferably 2 μm to 15 μm, and more preferably 3 μm to 10 μm.

[0043] The water contact angle of the surface of the surface treatment layer (laminated film) is 90° or more, preferably 93° or more. On the other hand, the water contact angle of the surface of the surface treatment layer (laminated film) is, for example, 125° or less.

[0044] [Retardation layer] The retardation layer may be a single layer or may have a laminated structure (for example, a two-layer structure). The retardation layer can be composed of any suitable material. Specifically, the retardation layer may be a resin film (a stretched film of a resin film), a liquid crystal compound alignment curing layer, or a combination thereof. The resin film typically contains a resin containing at least one bonding group selected from the group consisting of carbonate bonds and ester bonds. In other words, the resin film contains a polycarbonate-based resin, a polyester-based resin, or a polyester carbonate-based resin.

[0045] The retardation layer may have any suitable optical properties depending on the application and the like. In one embodiment, the retardation layer includes a first retardation layer that can function as a λ / 4 plate. The first retardation layer typically exhibits a refractive index characteristic of nx > ny = nz. The in-plane retardation Re(550) of the retardation layer is preferably 100 nm to 190 nm, more preferably 110 nm to 170 nm, and even more preferably 120 nm to 160 nm. Here, "ny = nz" includes not only the case where ny and nz are exactly equal but also the case where they are substantially equal. Therefore, within the range that does not impair the effects of the present invention, ny > nz or ny < nz may occur.

[0046] The Nz coefficient of the first phase difference layer described above is preferably 0.9 to 1.5, and more preferably 0.9 to 1.3. The first phase difference layer may exhibit inverse dispersion wavelength characteristics in which the phase difference value increases with the wavelength of the measured light. In this case, the Re(450) / Re(550) of the phase difference layer is preferably 0.8 or more and less than 1, and more preferably 0.8 or more and 0.95 or less.

[0047] When the above-mentioned first phase difference layer is composed of a resin film, its thickness is preferably 10 μm or more and 70 μm or less, and more preferably 20 μm or more and 60 μm or less.

[0048] [Protective film] The protective film described above comprises a base film having a first main surface and a second main surface facing each other, and an adhesive layer disposed on the first main surface side of the base film.

[0049] The base film constituting the protective film is formed from any suitable resin. Examples of materials for forming the base film include ester resins such as polyethylene terephthalate (PET) resins, cycloolefin resins such as norbornene resins, olefin resins such as polypropylene, polyamide resins, polycarbonate resins, and copolymer resins thereof. Preferably, an ester resin (for example, polyethylene terephthalate resin) is used.

[0050] The thickness of the base film is preferably 10 μm to 150 μm, more preferably 20 μm to 100 μm, and even more preferably 30 μm to 50 μm.

[0051] The peeling force of the protective film on an substrate with a water contact angle of 90° or more is 0.03 N / 25 mm or more. Satisfying this peeling force can prevent the protective film from lifting or peeling off the substrate during the manufacturing process of polarizing plates and image display devices, thereby contributing to improved yield. On the other hand, the peeling force of the protective film on an substrate with a water contact angle of 90° or more may be, for example, 0.09 N / 25 mm or less, or even 0.08 N / 25 mm or less.

[0052] Typically, the adherend is a polarizing plate. More specifically, it is the laminated film (the surface treatment layer of the laminated film).

[0053] The in-plane shear force of the protective film on the above-mentioned substrate is 35 N / 100 mm 2 The following, preferably 30N / 100mm 2 The following applies. By satisfying such shear force, deformation of polarizing plates due to handling can be suppressed during the manufacturing process of polarizing plates and image display devices. Specifically, when an external force is applied locally to the polarizing plate from the protective film side, the restraining force due to shear displacement that may occur at the interface between the protective film and the adherend (polarizing plate) can be weakened, and deformation (e.g., indentations) can be suppressed. Alternatively, deformation that has occurred can be reversed. On the other hand, the in-plane shear force of the protective film on the adherend is, for example, 10 N / 100 mm 2 That's all, 15N / 100mm 2 That's fine too.

[0054] The thickness of the adhesive layer constituting the protective film is, for example, greater than 10 μm, preferably 13 μm or more. On the other hand, the thickness of the adhesive layer constituting the protective film is, for example, 30 μm or less, preferably 27 μm or less. In one embodiment, the shear force is controlled by adjusting the thickness of the adhesive layer. For example, by adjusting the thickness of the adhesive layer, the shear force can be satisfied while ensuring adhesion to an adherend with a water contact angle of 90° or more.

[0055] The adhesive layer constituting the protective film typically contains an acrylic adhesive. The acrylic adhesive preferably contains a (meth)acrylic polymer having polar functional groups. The (meth)acrylic polymer having polar functional groups is typically a polymer of a monomer having polar functional groups and an alkyl (meth)acrylate. (Meth)acrylate refers to acrylate and / or methacrylate.

[0056] Examples of monomers having the above-mentioned polar functional groups include carboxyl group-containing monomers and hydroxyl group-containing monomers. These can be used alone or in combination. Preferably, carboxyl group-containing monomers are used.

[0057] The above-mentioned carboxyl group-containing monomers are compounds that have a carboxyl group and a polymerizable unsaturated double bond such as a (meth)acryloyl group or a vinyl group. 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. Among these, acrylic acid is preferably used.

[0058] In the above-mentioned (meth)acrylic polymer having polar functional groups, the content of the monomer component having polar functional groups is preferably 2 parts by weight or more, and more preferably 2.5 parts by weight or more, per 100 parts by weight of the monomer forming the (meth)acrylic polymer. With such a polymer, the above-mentioned peeling force can be achieved well. On the other hand, the content of the monomer component having polar functional groups is, for example, 10 parts by weight or less, preferably 5 parts by weight or less, and more preferably 3 parts by weight or less, per 100 parts by weight of the monomer forming the (meth)acrylic polymer. With such a polymer, the above-mentioned shear force can be achieved well.

[0059] Examples of the alkyl group contained in the above alkyl (meth)acrylate include linear or branched alkyl groups having 1 to 18 carbon atoms. Specific examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, amyl group, hexyl group, cyclohexyl group, heptyl group, 2-ethylhexyl group, isooctyl group, nonyl group, decyl group, isodecyl group, dodecyl group, isomyristyl group, lauryl group, tridecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group. These can be used alone or in combination. The average carbon number of the alkyl group is preferably 3 to 10. Among them, 2-ethylhexyl group is preferred.

[0060] In the (meth)acrylic polymer having the above polar functional group, the content of the alkyl (meth)acrylate is, for example, 10 parts by weight to 90 parts by weight, preferably 20 parts by weight to 80 parts by weight, more preferably 30 parts by weight to 70 parts by weight, based on 100 parts by weight of the monomers forming the (meth)acrylic polymer.

[0061] In one embodiment, the (meth)acrylic polymer contains structural units derived from other copolymerizable monomers. Examples of the other copolymerizable monomers include vinyl esters such as vinyl acetate and vinyl propionate. These can be used alone or in combination. Preferably, vinyl acetate is used.

[0062] In the (meth)acrylic polymer having the above polar functional group, the content of the other copolymerizable monomers is, for example, 5 parts by weight or more and 60 parts by weight or less, preferably 15 parts by weight or more and 55 parts by weight or less, more preferably 25 parts by weight or more and 50 parts by weight or less, based on 100 parts by weight of the monomers forming the (meth)acrylic polymer.

[0063] The weight average molecular weight Mw of the (meth)acrylic polymer having the above polar functional group is, for example, 30×10 4 ~60×10 4 and preferably 40×10 4 ~50×104 That is the case.

[0064] The glass transition temperature (Tg) of the (meth)acrylic polymer having the above polar functional group is preferably -15°C or lower, more preferably -20°C or lower, and even more preferably -25°C or lower. Such a polymer can effectively achieve the above shear force. On the other hand, the Tg of the (meth)acrylic polymer having the polar functional group is, for example, -70°C or higher, may be -60°C or higher, or -50°C or higher.

[0065] The above Tg (in K) can be determined from Fox's equation: 1 / Tg = Σ(Wi / Tgi). In Fox's equation, Tg represents the glass transition temperature of the copolymer (in K), Wi represents the weight fraction of monomer i in the copolymer (weight-based copolymerization ratio), and Tgi represents the glass transition temperature of the homopolymer of monomer i (in K). The glass transition temperature of the homopolymer can be the value described in publicly available documents.

[0066] The glass transition temperatures of typical monomer homopolymers are as follows: 2-Ethylhexyl acrylate: -70℃ Vinyl acetate: 32℃ Acrylic acid: 106℃ 2-Hydroxyethyl acrylate: 15℃ 4-Hydroxybutyl acrylate: -40℃

[0067] The above-mentioned acrylic adhesive can contain a crosslinking agent. Typically, the crosslinking agent is included in the acrylic adhesive in the form after the crosslinking reaction in the resulting adhesive layer. By including a crosslinking agent, for example, an appropriate cohesive force can be imparted to the acrylic adhesive. Examples of crosslinking agents include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, silicone-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, silane-based crosslinking agents, alkyl etherified melamine-based crosslinking agents, metal chelate-based crosslinking agents, peroxides, and polyfunctional monomers. These can be used alone or in combination.

[0068] The amount of crosslinking agent is, for example, 0.1 to 10 parts by weight, preferably 1 to 8 parts by weight, per 100 parts by weight of the (meth)acrylic polymer having the polar functional group described above.

[0069] The above-mentioned acrylic adhesive may contain any suitable additives. Examples of additives include leveling agents, crosslinking aids, tackifiers, plasticizers, pigments, dyes, fillers, anti-aging agents, conductive materials, antistatic agents, UV absorbers, light stabilizers, release modifiers, softeners, surfactants, flame retardants, and antioxidants. In one embodiment, the acrylic adhesive contains substantially no additives. Specifically, the content of the additive is preferably 0.01 parts by weight or less, and more preferably 0.001 parts by weight or less, per 100 parts by weight of the (meth)acrylic polymer having the polar functional group. For example, by adjusting the type and content of monomers forming the (meth)acrylic polymer to control the release force, the use of additives can be reduced, and the adhesion of dirt to the adherend (polarizing plate) can be prevented.

[0070] The surface resistance of the protective film (the surface resistance of the second main surface of the base film) is 1.0 × 10 8 It is preferable that the ratio is Ω / □ or greater, and more preferably 1.0 × 10⁻⁶. 9 The surface resistance is Ω / □ or greater. Such a surface resistance can be well achieved by providing a treatment layer on the second main surface side of the base film, as shown in Figure 1C. On the other hand, the surface resistance of the protective film is, for example, 1.0 × 10 13 It is less than or equal to Ω / □, preferably 1.0 × 10⁻⁶. 12 It is less than or equal to Ω / □, and more preferably 1.0 × 10 11 It is less than or equal to Ω / □.

[0071] The above-mentioned treatment layer typically contains an antistatic agent. Specifically, the above-mentioned treatment layer can be formed by applying and drying a coating solution containing an antistatic agent and a solvent (e.g., an organic solvent, an aqueous solvent such as water) onto a substrate film. Examples of antistatic agents include quaternary ammonium cation-containing polymers and polyaniline sulfonic acid-based antistatic agents, with quaternary ammonium cation-containing polymers being preferred.

[0072] Examples of quaternary ammonium cations contained in the above-mentioned quaternary ammonium cation-containing polymer include trimethylammonium cation, triethylammonium cation, tripropylammonium cation, methyldiethylammonium cation, ethyldimethylammonium cation, methyldipropylammonium cation, dimethylbenzylammonium cation, diethylbenzylammonium cation, methyldibenzylammonium cation, and ethyldibenzylammonium cation. Among these, trimethylammonium cation is preferably used.

[0073] A method for manufacturing an image display device according to one embodiment of the present invention includes attaching the polarizing plate (polarizing plate with protective film) to the image display panel body. Hereinafter, an organic EL display device will be used as an example of the image display device.

[0074] Figure 3 is a schematic cross-sectional view showing an outline of an organic EL display device according to one embodiment of the present invention, in which a polarizing plate is arranged on an organic EL panel. The organic EL panel 200 comprises an organic EL panel body 70 and a polarizing plate 110 with a protective film. The polarizer 30 of the polarizing plate 110 with a protective film is positioned on the organic EL panel body 70 side of the laminated film 20. Specifically, the polarizing plate 100 is attached to the organic EL panel body 70 by an adhesive layer 52.

[0075] The organic EL panel body 70 includes a substrate 71 and an upper structure layer 72 including a circuit layer containing thin-film transistors (TFTs), organic light-emitting diodes (OLEDs), and a sealing film that encloses the OLEDs. For example, when a flexible substrate (e.g., a resin substrate) is used as the substrate 71, the resulting organic EL display device can be curved, bent, folded, and rolled up.

[0076] Although not shown in the diagram, when used as an image display device for mobile devices, the organic EL panel body 70 may typically be equipped with a touch panel. The protective film 10 that may be located on the outermost surface of the organic EL panel 200 has the above surface resistance value (1.0 × 10 8 By satisfying the requirement of Ω / □ or higher, the occurrence of touch panel sensor errors in the manufacturing process of organic EL display devices can be suppressed, thereby improving manufacturing efficiency. Here, a touch panel sensor error refers to a phenomenon in the manufacturing process of an image display panel (image display device) (for example, the inspection process) where the screen does not respond or becomes unresponsive when touched with a finger to check the operability of the touch panel. [Examples]

[0077] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The thickness, water contact angle, and surface resistance values ​​were measured using the measurement methods described below. Unless otherwise specified, "parts" and "%" in the examples and comparative examples are based on weight. 1. Thickness Thicknesses of 10 μm or less were measured using a scanning electron microscope (JEOL Ltd., product name "JSM-7100F"). Thicknesses exceeding 10 μm were measured using a digital micrometer (Anritsu Corporation, product name "KC-351C"). 2.Water contact angle The water contact angle on the surface treatment layer side of the laminated film was measured. Specifically, the measurement was performed using the droplet method with a contact angle meter (Kyowa Interface Science Co., Ltd., product name "DMo-501", control box "DMC-2", control and analysis software "FAMAS (version 5.0.30)") in an environment of 23°C and 50% RH. The amount of distilled water dropped was 2 μL, and the contact angle was calculated from the image 5 seconds after dropping using the θ / 2 method. 3. Surface resistance value Surface resistance was measured using the eddy current method with a non-contact surface resistance meter, product name "EC-80," manufactured by Napson Corporation. The measurement temperature was 23°C.

[0078] [Example 1] (Fabrication of polarizers) A 12 μm thick polarizer was fabricated by uniaxially stretching a 30 μm thick polyvinyl alcohol (PVA) resin film (manufactured by Kuraray, product name "PE3000") in the longitudinal direction using a roll stretching machine to 5.9 times its length, while simultaneously applying swelling, dyeing, crosslinking, and washing treatments in that order, and finally drying the film. The above swelling treatment involved stretching the material 2.2 times while treating it with pure water at 20°C. Next, the dyeing treatment involved stretching the material 1.4 times while treating it in an aqueous solution at 30°C with an iodine-to-potassium iodide weight ratio of 1:7, where the iodine concentration was adjusted so that the individual transmittance of the resulting polarizer was 45.0%. Next, the crosslinking treatment was performed in two stages. In the first stage, the material was stretched 1.2 times while treating it in an aqueous solution of boric acid and potassium iodide at 40°C. The boric acid content of the aqueous solution for the first stage of crosslinking was 5.0% by weight, and the potassium iodide content was 3.0% by weight. In the second stage of crosslinking, the material was stretched 1.6 times while treating it in an aqueous solution of boric acid and potassium iodide at 65°C. The boric acid content of the aqueous solution for the second stage of crosslinking was 4.3% by weight, and the potassium iodide content was 5.0% by weight. Next, the polarizers were washed with an aqueous potassium iodide solution at 20°C. The potassium iodide content of the aqueous solution used for washing was 2.6% by weight. Finally, the polarizers were dried at 70°C for 5 minutes.

[0079] (Laminate fabrication) A TAC film (25 μm thick, Fujifilm Corporation, product name "TJ25UL") was bonded to one side of the obtained polarizer via an ultraviolet-curing adhesive, and a TAC film (laminated film, 32 μm thick) with a surface treatment layer formed on it was bonded to the other side of the polarizer via an ultraviolet-curing adhesive to obtain a laminate. The TAC film with the surface treatment layer formed on it is a TAC film (25 μm thick, Fujifilm Corporation, product name "TJ25UL") with a surface treatment layer (thickness: 7 μm, water contact angle: 93.3°) formed on it, and the surface treatment layer was formed by the procedure shown below.

[0080] <Surface treatment layer> 1. Formation of an anti-glare layer A mixture was prepared consisting of 50 parts by weight of UV-curable urethane acrylate resin (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., product name "UV1700TL", solids content 80%) and 50 parts by weight of polyfunctional acrylate mainly composed of pentaerythritol triacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., product name "Viscoat #300", solids content 100%). For every 100 parts by weight of the resin solids content of the mixture, 4 parts by weight of cross-linked polymethyl methacrylate particles (manufactured by Sekisui Chemical Co., Ltd., trade name "Techpolymer", weight-average particle size: 3 μm, refractive index: 1.525), 1.5 parts by weight of synthetic smectite (manufactured by Coop Chemical Co., Ltd., trade name "Lucentite SAN"), an organic clay (thixotropy imparting agent), 3 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name "OMNIRAD907"), and 0.15 parts by weight of a leveling agent (manufactured by Kyoeisha Chemical Co., Ltd., trade name "LE303", solids content 40%) were mixed. Here, the organic clay was diluted with toluene to a solids content of 6%. The resulting mixture was diluted with a toluene / ethyl acetate / cyclopentanone (CPN) mixed solvent (weight ratio 35 / 41 / 24) to a solid content concentration of 40% by weight to prepare an anti-glare layer forming material (coating solution).

[0081] The obtained anti-glare layer forming material (coating liquid) was coated onto a TAC film (25 μm thick, Fujifilm Corporation, product name "TJ25UL"). Subsequently, ultraviolet light with a wavelength of 365 nm was emitted from a high-pressure mercury lamp, with an integrated light intensity of 300 mJ / cm². 2 The coating film was irradiated in such a manner, and then heated at 80°C for 60 seconds to dry it, forming an anti-glare layer with a thickness of 7 μm.

[0082] 2. Formation of the anti-reflective layer A mixture was prepared by combining 100 parts by weight of a polyfunctional acrylate mainly composed of pentaerythritol triacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., product name "Viscoat #300", solid content 100% by weight), 100 parts by weight of hollow nanosilica particles (manufactured by JGC Catalysts & Chemicals Co., Ltd., product name "Thru-Ria 5320", solid content 20% by weight, weight-average particle size 75 nm), solid nanosilica particles (manufactured by Nissan Chemical Industries, Ltd., product name "MEK-2140Z-AC", solid content 30% by weight, weight-average particle size 10 nm), 12 parts by weight of a fluorine-containing additive (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KY-1203", solid content 20% by weight), and 3 parts by weight of a photopolymerization initiator (manufactured by BASF, product name "OMNIRAD907", solid content 100% by weight). A mixed solvent consisting of TBA, MIBK, and PMA in a weight ratio of 60:25:15 was added to the mixture to adjust the total solid content to 4% by weight, and the mixture was stirred to prepare a coating solution for forming an anti-reflective layer.

[0083] The obtained anti-reflective coating solution was applied to the anti-glare layer using a wire bar. The applied coating solution was heated at 80°C for 1 minute and dried to form a coating film. The resulting coating film was exposed to a high-pressure mercury lamp with an integrated light intensity of 300 mJ / cm². 2 The material was cured by irradiation with ultraviolet light to form an anti-reflective layer with a thickness of 0.1 μm. In this way, a surface treatment layer was formed.

[0084] (Fabrication of Laminate I) An acrylic adhesive layer (12 μm thick) was formed on the TAC film side of the obtained laminate, and a release liner was bonded to the surface of the formed adhesive layer. Next, a protective film was bonded to the laminated film side of the obtained laminate to obtain laminate I. The protective film used was prepared by the procedure shown below.

[0085] <Protective film> A PET film (38 μm thick, manufactured by Mitsubishi Chemical, product name "Diafoil T100M38") has an antistatic layer containing a quaternary ammonium cation-containing polymer formed on one side. The side without the antistatic layer is coated with the following adhesive composition A, and heated at 130°C for 1 minute to form an adhesive layer with a thickness of 13 μm and a surface resistance of 2.0 × 10⁻⁶. 9 A protective film with a value of Ω / □ was obtained.

[0086] <Adhesive composition A> A monomer composition containing 54.1 parts by weight of 2-ethylhexyl acrylate, 43.2 parts by weight of vinyl acetate, and 2.7 parts by weight of acrylic acid was polymerized to obtain an acrylic polymer (Tg: -32°C). 100 parts by weight of the obtained acrylic polymer was mixed with 4 parts by weight of an epoxy crosslinking agent (manufactured by Mitsubishi Gas Chemical, trade name "Tetrad C") and toluene as a solvent to prepare adhesive composition A.

[0087] (Fabrication of Laminate II) A 15 μm thick acrylic adhesive layer was formed on the surface of a 52 μm thick resin film (Teijin Corporation, "PureAce RM-147") that constitutes the phase difference layer. A polyethylene terephthalate film (38 μm thick, Mitsubishi Chemical Polyester Films Corporation, "MRF38") treated with a silicone-based release agent was laminated to the surface of this adhesive layer as a release liner to obtain laminate II.

[0088] (Fabrication of polarizing plates with protective film) The release liner of the laminate I was peeled off, and laminate I was bonded to the phase difference layer side of laminate II to obtain a polarizing plate with a protective film. The above bonding processes were carried out while the materials were being transported in a roll.

[0089] [Example 2] A polarizing plate with a protective film was obtained in the same manner as in Example 1, except that the thickness of the adhesive layer of the protective film was set to 15 μm.

[0090] [Example 3] A polarizing plate with a protective film was obtained in the same manner as in Example 1, except that the thickness of the adhesive layer of the protective film was set to 18 μm.

[0091] [Example 4] A polarizing plate with a protective film was obtained in the same manner as in Example 1, except that the thickness of the adhesive layer of the protective film was set to 23 μm.

[0092] [Example 5] A polarizing plate with a protective film was obtained in the same manner as in Example 1, except that the thickness of the adhesive layer of the protective film was set to 28 mm.

[0093] [Comparative Example 1] A polarizing plate with a protective film was obtained in the same manner as in Example 1, except that the thickness of the adhesive layer of the protective film was set to 5 μm.

[0094] [Comparative Example 2] A polarizing plate with a protective film was obtained in the same manner as in Example 1, except that the thickness of the adhesive layer of the protective film was set to 10 μm.

[0095] [Comparative Example 3] A polarizing plate with a protective film was obtained in the same manner as in Example 1, except that the adhesive layer constituting the protective film was formed with the adhesive composition B described below, and the thickness of the adhesive layer was set to 10 μm.

[0096] <Adhesive composition B> An acrylic polymer (Tg: -66°C) was obtained by polymerizing a monomer composition containing 96.2 parts by weight of 2-ethylhexyl acrylate and 3.8 parts by weight of 2-hydroxyethyl acrylate. Adhesive composition B was prepared by mixing 100 parts by weight of the obtained acrylic polymer with 3 parts by weight of aromatic polyisocyanate (manufactured by Tosoh, trade name "Coronate L") as a crosslinking agent, 0.02 parts by weight of dioctyl tin silaurate (manufactured by Tokyo Fine Chemical, trade name "Envirizer OL-1") as a crosslinking aid, 0.5 parts by weight of polyoxypropylene glycol (manufactured by Sanyo Chemical Industries, trade name "Sannix PP-3000") as a release aid, and toluene as a solvent.

[0097] [Comparative Example 4] A polarizing plate with a protective film was obtained in the same manner as in Example 1, except that the adhesive layer constituting the protective film was formed with the adhesive composition C described below, and the thickness of the adhesive layer was set to 23 μm.

[0098] <Adhesive composition C> A monomer composition containing 96.2 parts by weight of 2-ethylhexyl acrylate and 3.8 parts by weight of 2-hydroxyethyl acrylate was polymerized to obtain an acrylic polymer (Tg: -66°C). 100 parts by weight of the obtained acrylic polymer was mixed with 5 parts by weight of aliphatic polyisocyanate (manufactured by Tosoh, trade name "Coronate HX") as a crosslinking agent, 0.03 parts by weight of dioctyl tin silaurate (manufactured by Tokyo Fine Chemical, trade name "Envirizer OL-1") as a crosslinking aid, 0.3 parts by weight of polyoxyethylene alkylpropenylphenyl ether sulfate ammonium salt (manufactured by Daiichi Kogyo Seiyaku, trade name "Aqualon HS-10") as a release aid, and toluene as a solvent to prepare adhesive composition C.

[0099] The following evaluations were conducted on the examples and comparative examples. The evaluation results are summarized in Table 1. <Rating> 1. Shear force (in-plane direction) The shear force of the protective film against the polarizing plate was measured using a universal tensile and compression testing machine (manufactured by Shimadzu Corporation, product name "AUTOGRAPH AG-X plus"). Specifically, as shown in Figure 4, one end (10mm x 10mm) of a sample cut from the obtained protective film to a size of 10mm wide and 50mm long was attached to the center of the upper end of a polarizing plate (surface treatment layer side) cut to a size of 70mm long and 100mm wide. The other end (10mm x 10mm) of the sample and the center of the lower end of the polarizing plate were then clamped with a chuck. Under conditions of an initial chuck distance of 60mm and a tensile speed of 0.06mm / min, the sample was pulled in the longitudinal direction, and the maximum value within a 2.0mm stretch was recorded as the shear force (unit: N / 100mm). 2 The result was calculated as follows. The measurements were taken under conditions of 23°C and 50% RH. 2. Transformation As shown in Figure 5, a polarizing plate with protective film (a test piece measuring 60 mm in length and 60 mm in width) S was placed on the upper surface of a test plate P, which had a recess measuring 25 mm in length, 25 mm in width, and 1 mm in depth formed on its upper surface, with its release liner facing the test plate P. In this state, a rod with a radius of 8 mm was pressed from the upper surface (protective film side) of the polarizing plate S toward the bottom surface of the center of the recess in the test plate P. This position was held for 1.0 second, and when the rod was removed from the polarizing plate S, it was checked whether or not an indentation remained on the polarizing plate S. (Evaluation Criteria) Good: No indentations remain. Defect: Leaves indentations. 3. Peeling force Samples cut from the protective film-coated polarizing plates to a size of 50 mm in width and 100 mm in length were tested using a universal tensile testing machine (Shimadzu Corporation, product name "AUTOGRAPH AG-X plus") at a peeling speed of 300 mm / min and a peeling angle of 180°. The peeling force (unit: N / 25 mm) was measured in the longitudinal direction. Specifically, the peeling force of the protective film against the polarizing plate (surface treatment layer) was measured. The measurements were performed under conditions of 23°C and 50% RH. 4. Adhesion During roll transport, we checked whether the protective film on the polarizing plate with protective film lifted or peeled off. (Evaluation Criteria) Good: No lifting or peeling of the protective film occurs. Defect: The protective film may lift or peel off.

[0100] [Table 1]

[0101] In Comparative Examples 1-3, during the evaluation of deformation, the polarizing plates (polarizing plates with protective film) deformed upon indentation, and the deformation did not recover, leaving indentations. [Industrial applicability]

[0102] The polarizing plates obtained according to embodiments of the present invention can be suitably used as polarizing plates in image display devices. Typical image display devices include liquid crystal displays, organic EL displays, and inorganic EL displays. [Explanation of Symbols]

[0103] 10 Protective Films 11. Base film 12 Adhesive layer 13 Processing Layers 20 Laminated Film 21 Base material (protective layer) 22 Surface treatment layer 30 polarizers 40 protective layer 50 Adhesive layer 52 Adhesive layer 60 Retardation layer 90 Laminates 100 polarizing plates 110 Polarizing plate with protective film 200 Image display panel (OLED panel)

Claims

[Claim 1] It comprises a base film having a first main surface and a second main surface facing each other, and an adhesive layer disposed on the first main surface side of the base film, The peeling force for an adherend with a water contact angle of 90° or more is 0.03 N / 25 mm or more. The in-plane shear force on the adherend is 35 N / 100 mm. ２ The following is: Protective film.

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