Image display panel

Abstract

Provided is an image display panel in which a first transparent protective film, a polarizing film, and an image display cell are provided in said order, the first transparent protective film having an anti-reflection layer, wherein: there is optionally a layer adjacent to a polarizing membrane constituting the polarizing film; the polarizing membrane has a thickness of no more than 20 μm; the first transparent protective film having the anti-reflection layer has a moisture transmissibility of no more than 50 g / m2 / 24h; and the polarizing membrane and / or the layer adjacent to the polarizing membrane includes a water-soluble radical scavenger. The image display panel has excellent durability in high temperature environments and moist heat environments.

Description

[Technical Field]

[0001] The present invention relates to an image display panel. [Background technology]

[0002] Conventionally, dyed polyvinyl alcohol films (containing dichroic substances such as iodine or dichroic dyes) have been used as polarizing films for various image display devices, such as liquid crystal display devices and organic electroluminescence (EL) display devices, because they combine high transmittance and high polarization. The polarizing films are produced by subjecting polyvinyl alcohol films to various treatments, such as swelling, dyeing, crosslinking, and stretching, in a bath, followed by washing and drying. Furthermore, the polarizing films are typically used as polarizing films (polarizing plates) with transparent protective films, such as triacetyl cellulose, attached to one or both sides of the film using an adhesive.

[0003] The polarizing film is used as a laminated polarizing film (optical laminate) by laminating other optical layers as needed, and the polarizing film or the laminated polarizing film (optical laminate) is used as an image display panel by being bonded to an image display cell such as a liquid crystal cell or an organic EL element (Patent Document 1).

[0004] Known examples of the laminated polarizing film include polarizing films with antireflection layers that are provided on the viewing side surface of image display devices for the purposes of preventing degradation of image quality due to external light reflection, improving contrast, etc. (Patent Documents 2-3). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-102353 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-189211 [Patent Document 3] Japanese Patent Application Publication No. 2017-227898 Summary of the Invention [Problem to be solved by the invention]

[0006] With the recent development of autonomous driving technology, display designs for in-vehicle image display panels are becoming increasingly irregular and larger. Along with these changes in display design, there is a demand for methods to further improve durability in high-temperature and humid-hot environments.

[0007] In view of the above circumstances, an object of the present invention is to provide an image display panel that is excellent in durability in a high-temperature environment and a humid and hot environment. [Means for solving the problem]

[0008] That is, the present invention provides an image display panel in which a first transparent protective film having an antireflection layer, a polarizing film, and an image display cell are provided in this order, and the image display panel optionally has a layer adjacent to a polarizing film constituting the polarizing film, the polarizing film having a thickness of 20 μm or less, and the first transparent protective film having the antireflection layer has a moisture permeability of 50 g / (m 2 24 hours) or less, and the polarizing film and / or a layer adjacent to the polarizing film contains a water-soluble radical scavenger. [Effects of the Invention]

[0009] Although the details of the mechanism of action of the effect of the image display panel of the present invention are unclear, it is presumed as follows: However, the present invention is not interpreted as being limited to this mechanism of action.

[0010] The image display panel of the present invention is an image display panel in which a first transparent protective film having an antireflection layer, a polarizing film, and an image display cell are provided in this order, and optionally has a layer adjacent to a polarizing film constituting the polarizing film, the polarizing film having a thickness of 20 μm or less, and the first transparent protective film having the antireflection layer has a moisture permeability of 50 g / (m 224h) or less, and the polarizing film and / or the layer adjacent to the polarizing film contain a water-soluble radical scavenger. 2 By keeping the retention time (24 h) or less, moisture can be prevented from entering from outside the image display panel system (the viewing side), thereby preventing the polarizing film from peeling off from the image display cell in a humid and hot environment. Furthermore, by keeping the thickness of the polarizing film to 20 μm or less, moisture in the polarizing film can be reduced and polyenization in a high-temperature environment can be suppressed. Furthermore, by including a water-soluble radical scavenger in the polarizing film and / or a layer adjacent to the polarizing film, generated radicals can be captured and polyenization can be suppressed even in a high-temperature environment where polyenization is likely to occur in the polarizing film, thereby improving the high-temperature durability of the polarizing film. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic cross-sectional view showing one embodiment of an image display panel. DETAILED DESCRIPTION OF THE INVENTION

[0012] Fig. 1 is a schematic cross-sectional view showing one embodiment of the image display panel of the present invention. In the image display panel 100 of Fig. 1, a first transparent protective film 12 having an antireflection layer, a polarizing film 1, and an image display cell 90 are provided in this order via pressure-sensitive adhesive or adhesive layers 20 and 30. The polarizing film 1 also has at least a polarizing film 11. A second transparent protective film 13 may be attached to the polarizing film 11 on the side of the first transparent protective film 12 having the antireflection layer, and a third transparent protective film 14 may be attached to the polarizing film 11 on the side of the image display cell 90. The image display panel 100 may also optionally have a layer (not shown) adjacent to the polarizing film 11.

[0013] The first transparent protective film 12 having the antireflection layer has an antireflection layer 6 provided on a transparent film 81. The antireflection layer is a laminate of two or more thin films, and Fig. 1 shows an antireflection layer 6 made up of a laminate of four thin films 61, 62, 63, and 64. A hard coat layer 71 may be provided on the surface of the transparent film 81 on which the antireflection layer is formed.

[0014] The image display panel of the present invention is an image display panel in which a first transparent protective film having an antireflection layer, a polarizing film, and an image display cell are provided in this order, and optionally has a layer adjacent to a polarizing film constituting the polarizing film, the polarizing film having a thickness of 20 μm or less, and the first transparent protective film having the antireflection layer has a moisture permeability of 50 g / (m 2 24 h) or less, and the polarizing film and / or a layer adjacent to the polarizing film contains a water-soluble radical scavenger.

[0015] <First Transparent Protective Film Having Antireflection Layer> The first transparent protective film having an antireflection layer of the present invention has an antireflection layer consisting of two or more thin films provided on a transparent film. Generally, the optical film thickness (product of refractive index and thickness) of the thin films in the antireflection layer is adjusted so that the reversed phases of incident light and reflected light cancel each other out. By forming the antireflection layer as a multilayer laminate of two or more thin films with different refractive indices, the reflectance can be reduced over a wide wavelength range of visible light.

[0016] Examples of materials for the thin film constituting the antireflection layer include metal oxides, nitrides, and fluorides. Examples of low-refractive-index materials with a refractive index of 1.6 or less at a wavelength of 550 nm include silicon oxide and magnesium fluoride. Examples of high-refractive-index materials with a refractive index of 1.9 or more at a wavelength of 550 nm include titanium oxide, niobium oxide, zirconium oxide, tin-doped indium oxide (ITO), and antimony-doped tin oxide (ATO). In addition to the low-refractive-index layer and the high-refractive-index layer, a thin film made of, for example, titanium oxide or a mixture of the low-refractive-index material and the high-refractive-index material may be formed as a medium-refractive-index layer with a refractive index of approximately 1.50 to 1.85. The thin film constituting the antireflection layer preferably has low optical absorption of visible light, and a material with an extinction coefficient of 0.5 or less at a wavelength of 550 nm is preferably used.

[0017] The antireflection layer may have a laminated structure, for example, a two-layer structure consisting of, from the transparent film side, a high refractive index layer having an optical thickness of about 240 nm to 260 nm and a low refractive index layer having an optical thickness of about 120 nm to 140 nm; a three-layer structure consisting of a medium refractive index layer having an optical thickness of about 170 nm to 180 nm, a high refractive index layer having an optical thickness of about 60 nm to 70 nm and a low refractive index layer having an optical thickness of about 135 nm to 145 nm; a high refractive index layer having an optical thickness of about 20 nm to 55 nm and a low refractive index layer having an optical thickness of about 15 nm to 75 nm; Examples of such antireflection layers include a four-layer structure consisting of a low-refractive index layer with an optical thickness of about 100 nm to 160 nm, a high-refractive index layer with an optical thickness of about 60 nm to 330 nm, and a low-refractive index layer with an optical thickness of about 100 nm to 160 nm; and a five-layer structure consisting of a low-refractive index layer with an optical thickness of about 15 nm to 30 nm, a high-refractive index layer with an optical thickness of about 20 nm to 40 nm, a low-refractive index layer with an optical thickness of about 20 nm to 40 nm, a high-refractive index layer with an optical thickness of about 240 nm to 290 nm, and a low-refractive index layer with an optical thickness of about 100 nm to 200 nm. The ranges of refractive index and thickness of the thin films constituting the antireflection layer are not limited to the above examples. The antireflection layer may also be a laminate of six or more thin films.

[0018] The antireflection layer is preferably an alternate laminate of low-refractive index layers and high-refractive index layers. To reduce reflection at the air interface, the thin film (e.g., thin film 64) provided as the outermost layer of the antireflection layer (the surface opposite the transparent film) is preferably a low-refractive index layer. As described above, oxides are preferred as materials for the low-refractive index layers and the high-refractive index layers. In particular, the antireflection layer is preferably an alternate laminate of a silicon oxide (SiO2) thin film as a low-refractive index layer and a niobium oxide (Nb2O5) thin film as a high-refractive index layer.

[0019] The transparent film preferably has a visible light transmittance of 80% or more, more preferably 90% or more. The thickness of the transparent film is not particularly limited, but from the viewpoints of strength, workability such as handleability, thinness, etc., it is preferably about 5 to 300 μm, more preferably 10 to 300 μm, and even more preferably 20 to 200 μm.

[0020] Examples of resin materials constituting the transparent film include thermoplastic resins having excellent transparency, mechanical strength, and thermal stability. Specific examples of such thermoplastic resins include cellulose-based resins such as triacetyl cellulose, polyester-based resins, polyethersulfone-based resins, polysulfone-based resins, polycarbonate-based resins, polyamide-based resins, polyimide-based resins, polyolefin-based resins, (meth)acrylic resins, cyclic polyolefin-based resins (norbornene-based resins), polyarylate-based resins, polystyrene-based resins, polyvinyl alcohol-based resins, and mixtures thereof.

[0021] The transparent film may contain any appropriate additives such as ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, coloring inhibitors, flame retardants, antistatic agents, pigments, and colorants.

[0022] The moisture permeability of the first transparent protective film having the anti-reflection layer is 50 g / (m 2 The moisture permeability of the first transparent protective film having the antireflection layer is 30 g / (m 2 ) or less from the viewpoint of improving durability in a humid and hot environment.2 24h) or less, and 10g / (m 2 24h) or less is more preferable, and 5g / (m 2 It is more preferable that the moisture permeability is 40°C, 90% relative humidity difference, 1 m2 area. 2 It is the weight of water vapor that permeates a sample in 24 hours and is measured in accordance with JIS K7129:2008 Appendix B.

[0023] The method for forming the antireflection layer on the transparent film is not particularly limited, and for example, the method described in JP 2017-227898 A can be used as reference.

[0024] A hard coat layer is preferably provided on the antireflection layer side of the transparent film from the viewpoint of improving the mechanical properties of the antireflection layer, such as hardness, elastic modulus, etc. The hard coat layer preferably has high surface hardness and excellent scratch resistance, and can be formed by applying a solution containing a curable resin such as a thermosetting resin, an ultraviolet curable resin, or an electron beam curable resin.

[0025] Examples of the curable resin include polyester, acrylic, urethane, acrylic urethane, amide, silicone, silicate, epoxy, melamine, oxetane, and acrylic urethane resins. Among these, acrylic resins, acrylic urethane resins, and epoxy resins are preferred because of their high hardness, UV curability, and excellent productivity. UV-curable resins include UV-curable monomers, oligomers, and polymers.

[0026] The hard coat layer may also have antiglare properties. Examples of antiglare hard coat layers include those in which fine particles are dispersed in the curable resins described above. Examples of the fine particles include, without limitation, various metal oxide fine particles such as silica, alumina, titania, zirconia, calcium oxide, tin oxide, indium oxide, cadmium oxide, and antimony oxide; glass fine particles; crosslinked or uncrosslinked organic fine particles made of various transparent polymers such as polymethyl methacrylate, polystyrene, polyurethane, acrylic-styrene copolymer, benzoguanamine, melamine, and polycarbonate; and silicone fine particles. The average particle diameter of the fine particles is approximately 1 to 10 μm. The proportion of the fine particles is not particularly limited, but is generally approximately 5 to 20 parts by weight per 100 parts by weight of the matrix resin.

[0027] The thickness of the hard coat layer is not particularly limited, but from the viewpoint of realizing high hardness, it is preferably 0.5 μm or more, more preferably 1 μm or more, and from the viewpoint of ease of formation by coating, it is preferably 15 μm or less, more preferably 10 μm or less.

[0028] The surface of the transparent film, the hard coat layer, etc. may be subjected to a surface modification treatment such as corona treatment, plasma treatment, flame treatment, ozone treatment, primer treatment, glow treatment, saponification treatment, treatment with a coupling agent, etc. Furthermore, a primer layer of a metal oxide, nitride, etc. may be provided on the surface of the transparent film, the hard coat layer, etc. for the purpose of improving adhesion to an antireflection layer, etc.

[0029] <Polarizing film> The polarizing film of the present invention has a transparent protective film bonded to at least one surface of a polarizing film. Here, the transparent protective film bonded to the first transparent protective film side of the polarizing film having the antireflection layer is referred to as the second transparent protective film, and the transparent protective film bonded to the image display cell side of the polarizing film is referred to as the third transparent protective film. From the viewpoint of appearance stability during handling, the polarizing film preferably has a second transparent protective film bonded to the first transparent protective film side of the polarizing film having the antireflection layer. The polarizing film and the transparent protective film are usually bonded together via a pressure-sensitive adhesive layer or an adhesive layer.

[0030] <Polarizing film> The polarizing film has a polarizing layer formed by adsorbing and aligning a dichroic material such as iodine or a dichroic dye on a polyvinyl alcohol-based film. From the viewpoint of the initial polarization performance of the polarizing film, the polarizing layer is preferably an iodine-based polarizing layer containing iodine as the dichroic material.

[0031] The polyvinyl alcohol (PVA) film is transparent in the visible light region and can be used without any particular limitation as long as it disperses and adsorbs dichroic substances such as iodine and dichroic dyes. Examples of materials for the polyvinyl alcohol film include polyvinyl alcohol and its derivatives. Examples of polyvinyl alcohol derivatives include polyvinyl formal, polyvinyl acetal; olefins such as ethylene and propylene; unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and their alkyl esters, modified with acrylamide, etc. The polyvinyl alcohol preferably has an average degree of polymerization of approximately 100 to 10,000, more preferably approximately 1,000 to 10,000, and even more preferably approximately 1,500 to 4,500. The polyvinyl alcohol preferably has a saponification degree of approximately 80 to 100 mol%, more preferably approximately 95 mol% to 99.95 mol%. The average degree of polymerization and the saponification degree can be determined in accordance with JIS K 6726.

[0032] From the viewpoint of improving durability in high-temperature environments, the polarizing film preferably contains a water-soluble radical scavenger. From the viewpoint of easy migration into moisture in the polarizing film, the water-soluble radical scavenger is preferably a compound that can dissolve at least 1 part by weight in 100 parts by weight of water at 25°C, more preferably a compound that can dissolve at least 2 parts by weight in 100 parts by weight of water at 25°C, and even more preferably a compound that can dissolve at least 5 parts by weight in 100 parts by weight of water at 25°C. The water-soluble radical scavengers may be used alone or in combination of two or more types.

[0033] The water-soluble radical scavenger is presumed to be capable of suppressing polyenation of the polarizing film in a high-temperature environment. Examples of the water-soluble radical scavenger include compounds having a radical scavenging function, such as hindered phenol-based, hindered amine-based, phosphorus-based, sulfur-based, benzotriazole-based, benzophenone-based, hydroxylamine-based, salicylic acid ester-based, and triazine-based compounds. From the viewpoint of the radical species generated in the polarizing film, the water-soluble radical scavenger is preferably, for example, a compound having a nitroxy radical or a nitroxide group.

[0034] As the nitroxy radical or the compound having a nitroxide group, an N-oxyl compound (having a functional group of CN(-C)-O) is preferred from the viewpoint of having a radical that is relatively stable in air at room temperature. · Compounds having the formula (O · represents an oxy radical), and known compounds can be used. Examples of N-oxyl compounds include compounds having an organic group with the following structure: [ka] (In general formula (1), R 1 represents an oxy radical, R 2 From R 5are each independently a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and n is 0 or 1.) In addition, in general formula (1), the left side of the dotted line represents any organic group.

[0035] Furthermore, from the viewpoint of being able to efficiently capture radicals generated in the polarizing film, the water-soluble radical scavenger preferably has a molecular weight of 1,000 or less, more preferably 500 or less, and even more preferably 300 or less.

[0036] When the polarizing film contains the water-soluble radical scavenger, the content of the water-soluble radical scavenger is preferably 0.005% by weight or more, more preferably 0.01% by weight or more, and even more preferably 0.1% by weight or more, from the viewpoint of improving durability in high-temperature environments, and is preferably 20% by weight or less, more preferably 15% by weight or less, and even more preferably 10% by weight or less.

[0037] The polarizing film can be obtained by a conventional method for producing a polarizing film, for example, by subjecting the polyvinyl alcohol film to any of a swelling step, a washing step, a dyeing step, a crosslinking step, and a stretching step. When the polarizing film contains the water-soluble radical scavenger, the treatment bath in at least one of the swelling step, the washing step, the dyeing step, the crosslinking step, and the stretching step may contain the water-soluble radical scavenger.

[0038] The polarizing film has a thickness of 20 μm or less from the viewpoint of reducing the moisture content in the polarizing film and suppressing polyenization in a high-temperature environment. The polarizing film preferably has a thickness of 1 μm or more, more preferably 2 μm or more, from the viewpoint of improving the initial polarization degree of the polarizing film. In particular, to obtain a polarizing film having a thickness of approximately 8 μm or less, the following method for producing a thin polarizing film can be applied, in which the polyvinyl alcohol-based film is a laminate including a polyvinyl alcohol-based resin layer formed on a thermoplastic resin substrate.

[0039] A polarizing film (thin polarizing film) can be obtained by a conventional polarizing film manufacturing method, for example, by forming a polyvinyl alcohol-based resin layer (PVA-based resin layer) containing a polyvinyl alcohol-based resin (PVA-based resin) on one side of a long thermoplastic resin substrate to prepare a laminate, and then, while transporting the obtained laminate in the longitudinal direction, subjecting the laminate to optional insolubilization treatment, crosslinking treatment, and washing treatment, and at least an auxiliary in-air stretching treatment, dyeing treatment, and underwater stretching treatment. When the polarizing film contains the water-soluble radical scavenger, the treatment bath in any one or more of the insolubilization treatment, crosslinking treatment, washing treatment, dyeing treatment, and underwater stretching treatment may contain the water-soluble radical scavenger.

[0040] <Transparent protective film> The transparent protective film is not particularly limited, and various transparent protective films used in polarizing films can be used. Examples of materials that can be used to form the transparent protective film include thermoplastic resins that are excellent in transparency, mechanical strength, thermal stability, moisture barrier properties, and isotropy. Examples of thermoplastic resins include cellulose ester resins such as triacetyl cellulose, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins such as nylon and aromatic polyamide, polyimide resins, polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers, (meth)acrylic resins, cyclic polyolefin resins (norbornene resins) having a cyclo- or norbornene structure, polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. The transparent protective film can also include a cured layer formed from a thermosetting resin or ultraviolet-curable resin, such as a (meth)acrylic, urethane, acrylic urethane, epoxy, or silicone resin. Among these, cellulose ester resins, polycarbonate resins, (meth)acrylic resins, cyclic polyolefin resins, and polyester resins are preferred.

[0041] The thickness of the transparent protective film can be determined as appropriate, but generally, from the viewpoints of workability such as strength and handling, thinness, etc., it is preferably about 1 to 500 μm, more preferably about 1 to 300 μm, and even more preferably about 5 to 100 μm.

[0042] When the transparent protective films are attached to both sides of the polarizing film, the transparent protective films on both sides may be the same or different.

[0043] The transparent protective film can be a retardation plate having a front retardation of 40 nm or more and / or a thickness retardation of 80 nm or more. The front retardation is usually controlled to be in the range of 40 to 200 nm, and the thickness retardation is usually controlled to be in the range of 80 to 300 nm. When a retardation plate is used as the transparent protective film, the retardation plate also functions as the transparent protective film, allowing for a thinner film.

[0044] Examples of the retardation plate include a birefringent film obtained by uniaxially or biaxially stretching a polymer material, an oriented film of a liquid crystal polymer, and an oriented layer of a liquid crystal polymer supported by a film. The thickness of the retardation plate is not particularly limited, but is generally about 20 to 150 μm. The retardation plate may be used by being attached to a transparent protective film that does not have a retardation.

[0045] The transparent protective film may contain any appropriate additives such as ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, coloring inhibitors, flame retardants, antistatic agents, pigments, and colorants.

[0046] The third transparent protective film has a moisture permeability of 300 g / (m) from the viewpoint of production efficiency in the drying process after lamination. 2 24h) or less, and 200g / (m 2 From the viewpoint of durability of the polarizing film under high temperature and high humidity, the second transparent protective film has a moisture permeability of 100 g / (m 2 24h) or more, and 200g / (m 2 24h) or more, and the moisture permeability is 1000g / (m 2 24h) or less, and 600g / (m 2The moisture permeability can be calculated in accordance with the moisture permeability test (cup method) of JIS Z0208 by cutting a sample to a diameter of 60 mm, placing it in a moisture permeability cup containing approximately 15 g of calcium chloride, placing it in an incubator at a temperature of 40°C and a humidity of 90% RH, and measuring the increase in weight of the calcium chloride before and after leaving it for 24 hours.

[0047] On the surface of the transparent protective film to which the polarizing film is not attached, other layers such as a hard coat layer, an anti-sticking layer, a diffusion layer, an anti-glare layer, etc. The above other layers may be provided on the protective film itself, or may be provided separately from the protective film.

[0048] <Adhesive layer> The adhesive layer may be formed from various adhesives used in polarizing films, such as rubber-based adhesives, acrylic-based adhesives, silicone-based adhesives, urethane-based adhesives, vinyl alkyl ether-based adhesives, polyvinyl alcohol-based adhesives, polyvinyl pollidone-based adhesives, polyacrylamide-based adhesives, and cellulose-based adhesives. Among these, acrylic-based adhesives are preferred. The acrylic-based adhesive contains an acrylic polymer as a base polymer, and examples of the acrylic-based adhesives include those described in JP 2017-75998 A and the like.

[0049] The acrylic polymer in the acrylic pressure-sensitive adhesive has a main skeleton of a (meth)acrylic acid alkyl ester monomer unit. A (meth)acrylic acid alkyl ester having an alkyl group containing 1 to 20 carbon atoms is preferably used as the (meth)acrylic acid alkyl ester. The content of the (meth)acrylic acid alkyl ester is preferably 40% by weight or more, more preferably 60% by weight or more, based on the total amount of monomer components constituting the base polymer. Furthermore, from the viewpoint of adjusting the adhesive properties of the pressure-sensitive adhesive, a monomer unit such as a nitrogen-containing monomer unit or a hydroxyl group-containing monomer may be contained. Furthermore, a crosslinking agent may be used to form a crosslinked structure in the pressure-sensitive adhesive layer. Examples of commonly used crosslinking agents include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, carbodiimide-based crosslinking agents, and metal chelate-based crosslinking agents. The amount of crosslinking agent used is typically 10 parts by weight or less, preferably 5 parts by weight or less, based on 100 parts by weight of the base polymer.

[0050] To the pressure-sensitive adhesive, tackifiers such as silane coupling agents, terpene-based tackifiers, styrene-based tackifiers, phenol-based tackifiers, rosin-based tackifiers, and epoxy-based tackifiers may be added in order to adjust the adhesive strength. Furthermore, to improve light resistance, ultraviolet absorbers may be added. In addition to the components exemplified above, the pressure-sensitive adhesive may contain additives such as plasticizers, softeners, antidegradants, fillers, colorants, antioxidants, surfactants, and antistatic agents, provided that the properties of the pressure-sensitive adhesive are not impaired.

[0051] Examples of methods for forming the pressure-sensitive adhesive layer include a method in which the pressure-sensitive adhesive is applied to a release-treated separator or the like, dried to form a pressure-sensitive adhesive layer, and then transferred to a polarizing film or the like, or a method in which the pressure-sensitive adhesive is applied to a polarizing film or the like, and dried to form a pressure-sensitive adhesive layer, etc. The thickness of the pressure-sensitive adhesive layer is not particularly limited and is, for example, about 1 to 100 μm, and preferably about 2 to 50 μm.

[0052] <Adhesive layer> The adhesive layer may be formed using various adhesives used in polarizing films, such as isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl latex-based adhesives, and water-based polyesters. These adhesives are usually used as aqueous solution adhesives (water-based adhesives) and contain 0.5 to 60% by weight of solids. Among these, polyvinyl alcohol-based adhesives are preferred, and acetoacetyl group-containing polyvinyl alcohol-based adhesives are more preferred.

[0053] The aqueous adhesive may contain a crosslinking agent. The crosslinking agent is typically a compound having at least two functional groups per molecule that are reactive with the polymer or other components that make up the adhesive, such as alkylenediamines, isocyanates, epoxies, aldehydes, and amino-formaldehydes such as methylol urea and methylol melamine. The amount of crosslinking agent in the adhesive is typically about 10 to 60 parts by weight per 100 parts by weight of the polymer or other components that make up the adhesive.

[0054] In addition to the above, examples of the adhesive include active energy ray-curable adhesives such as ultraviolet ray-curable adhesives and electron beam-curable adhesives. Examples of the active energy ray-curable adhesives include (meth)acrylate-based adhesives. Examples of the curable components in the (meth)acrylate-based adhesives include compounds having a (meth)acryloyl group and compounds having a vinyl group. Examples of the compounds having a (meth)acryloyl group include alkyl (meth)acrylates such as linear alkyl (meth)acrylates, alicyclic alkyl (meth)acrylates, and polycyclic alkyl (meth)acrylates having 1 to 20 carbon atoms; hydroxyl group-containing (meth)acrylates; and epoxy group-containing (meth)acrylates such as glycidyl (meth)acrylate. The (meth)acrylate adhesive may contain a nitrogen-containing monomer such as hydroxyethyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, (meth)acrylamide, or (meth)acryloylmorpholine. The (meth)acrylate adhesive may contain a polyfunctional monomer as a crosslinking component, such as tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecane dimethanol diacrylate, cyclic trimethylolpropane formal acrylate, dioxane glycol diacrylate, or EO-modified diglycerin tetraacrylate. Furthermore, compounds containing epoxy groups or oxetanyl groups can also be used as cationic polymerization-curable adhesives. The epoxy group-containing compound is not particularly limited as long as it has at least two epoxy groups in the molecule, and various commonly known curable epoxy compounds can be used.

[0055] The adhesive may contain appropriate additives as needed, such as coupling agents such as silane coupling agents and titanium coupling agents, adhesion promoters such as ethylene oxide, ultraviolet absorbers, anti-degradants, dyes, processing aids, ion trapping agents, antioxidants, tackifiers, fillers, plasticizers, leveling agents, foam inhibitors, antistatic agents, heat stabilizers, and hydrolysis stabilizers.

[0056] The adhesive may be applied to either the transparent protective film side (or the functional layer side) described below, the polarizing film side, or both. After lamination, a drying step is performed to form an adhesive layer consisting of the applied and dried layer. After the drying step, ultraviolet light or electron beams may be irradiated as necessary. The thickness of the adhesive layer is not particularly limited, and is preferably about 30 to 5,000 nm, more preferably about 100 to 1,000 nm, when a water-based adhesive or the like is used. When a UV-curable adhesive or an electron beam-curable adhesive is used, the thickness is preferably about 0.1 to 100 μm, more preferably about 0.5 to 10 μm.

[0057] The transparent protective film and the polarizing film may be laminated via an intervening layer such as a surface modification treatment layer, an easy-adhesive layer, a blocking layer, or a refractive index adjustment layer.

[0058] Examples of the surface modification treatment for forming the surface modification layer include corona treatment, plasma treatment, primer treatment, and saponification treatment.

[0059] Examples of the easy-adhesion adhesive that forms the easy-adhesion layer include forming materials containing various resins having a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, a polyurethane skeleton, a silicone skeleton, a polyamide skeleton, a polyimide skeleton, a polyvinyl alcohol skeleton, etc. The easy-adhesion layer is usually provided in advance on the protective film, and the easy-adhesion layer side of the protective film and the polarizing film are laminated with the pressure-sensitive adhesive layer or the adhesive layer.

[0060] The blocking layer has the function of preventing impurities such as oligomers and ions eluted from a transparent protective film, etc., from migrating (penetrating) into the polarizing film. The blocking layer may be any layer as long as it is transparent and can prevent impurities from eluting from a transparent protective film, etc. Examples of materials for forming the blocking layer include urethane prepolymer-based forming materials, cyanoacrylate-based forming materials, and epoxy-based forming materials.

[0061] The refractive index adjusting layer is a layer provided to suppress a decrease in transmittance due to reflection between layers having different refractive indices, such as the transparent protective film and a polarizing film, etc. Examples of refractive index adjusting materials that form the refractive index adjusting layer include forming agents containing various resins such as silica-based, acrylic-based, acrylic-styrene-based, and melamine-based resins and additives.

[0062] <Layer adjacent to the polarizing film> The layer adjacent to the polarizing film constituting the polarizing film of the present invention (layer adjacent to the polarizing film) is optionally provided, and specifically corresponds to the pressure-sensitive adhesive layer or the adhesive layer as well as a functional layer.

[0063] The layer adjacent to the polarizing film may contain a water-soluble radical scavenger, from the viewpoint that the water-soluble radical scavenger is easily transferred to the moisture in the polarizing film and can scavenge radicals that may be generated by the progress of polyenization.

[0064] When the layer adjacent to the polarizing film contains the water-soluble radical scavenger, the content of the water-soluble radical scavenger in the layer adjacent to the polarizing film is preferably 1 wt % or more, more preferably 5 wt % or more, and even more preferably 10 wt % or more, from the viewpoint of suppressing polyenization of the polarizing film. Furthermore, from the viewpoint of the appearance of the layer adjacent to the polarizing film, the content of the water-soluble radical scavenger in the layer adjacent to the polarizing film is preferably 50 wt % or less, more preferably 40 wt % or less, and even more preferably 30 wt % or less.

[0065] The functional layer can be formed from any material as long as it is a binder resin capable of forming a layer such as a coating film, and examples thereof include water-soluble plastic resins such as polyvinyl alcohol resins and polyacrylamides. Among these, polyvinyl alcohol resins are preferred from the viewpoints of adhesion to the polarizing film and durability. The binder resins can be used alone or in combination of two or more.

[0066] An example of the polyvinyl alcohol-based resin is polyvinyl alcohol. Polyvinyl alcohol can be obtained by saponifying polyvinyl acetate. Another example of the polyvinyl alcohol-based resin is a saponified copolymer of vinyl acetate and a copolymerizable monomer. When the copolymerizable monomer is ethylene, an ethylene-vinyl alcohol copolymer is obtained. Examples of the copolymerizable monomer include unsaturated carboxylic acids and their esters, such as maleic acid (anhydride), fumaric acid, crotonic acid, itaconic acid, and (meth)acrylic acid; α-olefins, such as ethylene and propylene; (meth)allylsulfonic acid (sodium); sodium sulfonate (monoalkyl maleate); sodium disulfonate alkyl maleate; N-methylolacrylamide; alkali salts of acrylamidoalkylsulfonic acid; N-vinylpyrrolidone; and N-vinylpyrrolidone derivatives. Another example of the polyvinyl alcohol-based resin is a modified polyvinyl alcohol-based resin having a hydrophilic functional group on the side chain of the polyvinyl alcohol or its copolymer. Examples of the hydrophilic functional group include an acetoacetyl group, a carbonyl group, etc. The modified polyvinyl alcohol resin may be a polyvinyl alcohol resin that has been acetalized, urethane-modified, etherified, grafted, phosphate-modified, or the like.

[0067] The saponification degree of the polyvinyl alcohol resin may be, for example, 88% or more, and from the viewpoint of optical durability under high temperature and high humidity, the saponification degree is preferably 90% or more, and more preferably 95% or more. The saponification degree can be determined in accordance with JIS K 6726.

[0068] The functional layer is formed from a resin composition containing the binder resin as a main component, and, for example, the proportion of the binder resin in the functional layer is preferably 70% by weight or more, more preferably 80% by weight or more, and even more preferably 90% by weight or more.

[0069] The resin composition may be prepared as a solution by dissolving or dispersing the binder resin in a solvent. Examples of the solvent include water, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, glycols, alcohols, and amines such as ethylenediamine and diethylenetriamine. The solvents may be used alone or in combination of two or more.

[0070] The functional layer may contain additives such as a crosslinking agent, a plasticizer, a surfactant, a coupling agent, a tackifier, a heat stabilizer, and a hydrolysis stabilizer.

[0071] The functional layer may be formed, for example, by applying the resin composition to the polarizing film and drying the applied composition. The application method is not particularly limited, and examples thereof include roll coating, spin coating, wire bar coating, dip coating, die coating, curtain coating, spray coating, and knife coating.

[0072] From the viewpoint of suppressing polyenization of the polarizing film, the functional layer preferably has a thickness of 0.1 μm or more, more preferably 0.2 μm or more, and even more preferably 0.5 μm or more, and from the viewpoint of optical durability under high temperature and high humidity conditions, the functional layer preferably has a thickness of 10 μm or less, more preferably 5 μm or less, and even more preferably 1 μm or less.

[0073] The polarizing film may also be a laminated polarizing film (optical laminate) in which the polarizing film is bonded to an optical layer. The optical layer is not particularly limited, and may be, for example, one or more optical layers that are sometimes used in the formation of liquid crystal displays, such as a reflector, a semi-transmitting plate, a retardation plate (including half-wave or quarter-wave plates), or a viewing angle compensation film. Examples of the polarizing film include a reflective polarizing film or a semi-transmitting polarizing film in which a reflector or semi-transmitting reflector is laminated on the polarizing film; an elliptical polarizing film or a circular polarizing film in which a retardation plate is laminated on the polarizing film; a wide-viewing-angle polarizing film in which a viewing angle compensation film is laminated on the polarizing film; and a polarizing film in which a brightness-enhancing film is laminated on the polarizing film.

[0074] The pressure-sensitive adhesive layer or adhesive layer may be applied in advance to one or both surfaces of the polarizing film in order to bond an image display cell such as a liquid crystal cell or an organic EL element, or a first transparent protective film having the anti-reflection layer.

[0075] It is preferable that a separator be temporarily attached to cover the exposed surface of the pressure-sensitive adhesive layer or the adhesive layer to prevent contamination, etc., until the product is put into practical use. This prevents contamination, etc., of the pressure-sensitive adhesive layer or the adhesive layer under normal handling conditions. Examples of the separator include appropriate thin sheets such as plastic films, rubber sheets, paper, cloth, nonwoven fabrics, nets, foam sheets, metal foils, and laminates thereof, which are coated with an appropriate release agent such as a silicone-based, long-chain alkyl-based, fluorine-based, or molybdenum sulfide-based release agent, as needed.

[0076] <Image display panel> The image display panel of the present invention comprises a first transparent protective film having the antireflection layer, the polarizing film, and an image display cell, which are provided in this order, and are usually bonded together via the pressure-sensitive adhesive layer or the adhesive layer.

[0077] <Image display cell> Examples of the image display cell of the present invention include a liquid crystal cell and an organic EL cell. The liquid crystal cell may be, for example, a reflective liquid crystal cell that utilizes external light, a transmissive liquid crystal cell that utilizes light from a light source such as a backlight, or a semi-transmissive semi-reflective liquid crystal cell that utilizes both external and light from the light source. When the liquid crystal cell utilizes light from a light source, the image display device (liquid crystal display device) has a polarizing film disposed on the side opposite the viewing side of the image display cell (liquid crystal cell), and further has a light source disposed thereon. The polarizing film on the light source side and the liquid crystal cell are preferably bonded together via an appropriate adhesive layer. The liquid crystal cell may be driven in any mode, such as VA mode, IPS mode, TN mode, STN mode, or bend alignment (π type).

[0078] The organic EL cell preferably has a light-emitting body (organic electroluminescence light-emitting body) formed by sequentially laminating a transparent electrode, an organic light-emitting layer, and a metal electrode on a transparent substrate. The organic light-emitting layer is a laminate of various organic thin films, and various layer configurations can be adopted, such as a laminate of a hole-injection layer made of a triphenylamine derivative or the like and a light-emitting layer made of a fluorescent organic solid such as anthracene, a laminate of such a light-emitting layer and an electron-injection layer made of a perylene derivative or the like, or a laminate of a hole-injection layer, a light-emitting layer, and an electron-injection layer.

[0079] The image display cell usually has an outermost surface (outermost layer) made of a plastic substrate or a glass substrate, but from the viewpoint of heat resistance and moist heat resistance, it is preferable that the outermost surface on the viewing side is a glass substrate. [Example]

[0080] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0081] Example 1 <Preparation of polarizing film> A polyvinyl alcohol film with an average degree of polymerization of 2,400, a degree of saponification of 99.9 mol%, and a thickness of 45 μm was prepared. The polyvinyl alcohol film was immersed in a 30°C swelling bath (water bath) for 30 seconds between rolls with different peripheral speed ratios, where it was stretched 2.2 times in the conveying direction while swelling (swelling step). Subsequently, the film was immersed in a 30°C dye bath (iodine solution obtained by blending iodine and potassium iodide in a weight ratio of 1:7 with 100 parts by weight of water) for 30 seconds, with the iodine concentration adjusted so that the polarizing film had the desired transmittance. The film was then stretched 3.3 times in the conveying direction relative to the original polyvinyl alcohol film (polyvinyl alcohol film that was not stretched in the conveying direction at all) while dyeing (dyeing step). The dyed polyvinyl alcohol film was then immersed in a 40°C crosslinking bath (aqueous solution containing 3.5 wt% boric acid, 3.0 wt% potassium iodide, and 3.6 wt% zinc sulfate) for 28 seconds and stretched 3.6 times in the machine direction relative to the original polyvinyl alcohol film (crosslinking step). The resulting polyvinyl alcohol film was then immersed in a 64°C stretching bath (aqueous solution containing 4.5 wt% boric acid, 5.0 wt% potassium iodide, and 5.0 wt% zinc sulfate) for 60 seconds and stretched 6.0 times in the machine direction relative to the original polyvinyl alcohol film (stretching step). The resulting polyvinyl alcohol film was then immersed in a 27°C washing bath (aqueous solution containing 2.3 wt% potassium iodide and 1.0 wt% water-soluble radical scavenger, a compound represented by the following general formula (2)) for 10 seconds (washing step). The washed polyvinyl alcohol film was dried at 40°C for 30 seconds to produce a polarizing film. The content of the compound represented by the following general formula (2) in the polarizing film was 0.3% by weight, and the thickness of the polarizing film was 18 μm. [ka]

[0082] <Method for measuring the content (wt%) of water-soluble radical scavenger in polarizing film> Approximately 20 mg of polarizing film was collected, quantified, and dissolved by heating in 1 mL of water, then diluted with 4.5 mL of methanol. The resulting extract was filtered through a membrane filter, and the concentration of the water-soluble radical scavenger in the filtrate was measured using HPLC (Waters ACQUITY UPLC H-class Bio).

[0083] <Preparation of polarizing film> The adhesive used was an aqueous solution containing an acetoacetyl group-containing polyvinyl alcohol resin (average polymerization degree 1,200, saponification degree 98.5 mol%, acetoacetylation degree 5 mol%) and methylolmelamine in a weight ratio of 3:1. Using this adhesive, a cycloolefin-based transparent protective film (Zeon Corporation, ZT12, moisture permeability 10 g / (m)) with a thickness of 18 μm was attached as a third transparent protective film to one side (the image display cell side) of the polarizing film obtained above. 2 On the other side (viewing side), a 48 μm thick transparent protective film (moisture permeability 300 g / (m)) was used as a second transparent protective film, which was made of triacetyl cellulose film (manufactured by Fujifilm, product name "TJ40UL") with HC formed thereon. 2 After laminating the polarizing film on both sides of the film using a roll laminator, the film was subsequently dried by heating in an oven (at 90°C for 10 minutes) to produce a polarizing film with transparent protective films laminated on both sides of the polarizing film.

[0084] <Preparation of acrylic adhesive> A four-neck flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser was charged with a monomer mixture containing 99 parts of butyl acrylate and 1 part of 4-hydroxybutyl acrylate. Furthermore, 0.1 parts of 2,2'-azobisisobutyronitrile as a polymerization initiator and 100 parts of ethyl acetate were charged to 100 parts of the monomer mixture (solid content). Nitrogen gas was introduced with gentle stirring to replace the atmosphere, and the temperature in the flask was maintained at around 55°C to carry out a polymerization reaction for 8 hours, producing an acrylic polymer solution with a weight-average molecular weight (Mw) of 1,800,000. Thereafter, 0.02 parts of an isocyanate crosslinking agent (manufactured by Tosoh Corporation, trade name "Takenate D110N", trimethylolpropane / xylylene diisocyanate adduct) and 0.2 parts of a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "X-41-1056") were blended with 100 parts of the solid content of the obtained acrylic polymer solution to prepare a solution of an acrylic pressure-sensitive adhesive composition.

[0085] <Preparation of polarizing film with adhesive layer> The solution of the acrylic pressure-sensitive adhesive composition obtained above was applied to one side of a polyethylene terephthalate film (Mitsubishi Chemical Polyester Film Co., Ltd., product name "MRF38", separator film) treated with a silicone-based release agent so that the thickness of the pressure-sensitive adhesive layer after drying would be 20 μm, and the film was dried at 90° C. for 1 minute to form a pressure-sensitive adhesive layer on the surface of the separator film. Next, the pressure-sensitive adhesive layer formed on the separator film was transferred to the protective film surface on the image display cell side of the polarized film prepared above, to prepare a polarized film with a pressure-sensitive adhesive layer.

[0086] <Preparation of First Transparent Protective Film Having Antireflection Layer> One hundred parts by weight (solid content) of ultraviolet-curable acrylic resin (DIC, product name "GRANDIC PC-1070") was applied to one side of a 40-μm-thick cellulose triacetate film (Fujifilm, product name "Fujitack") so that the thickness after drying would be 5 μm, and the film was dried at 80°C for 3 minutes. Thereafter, a high-pressure mercury lamp was used to apply the resin to the film with an integrated light intensity of 200 mJ / cm. 2The coating layer was cured by irradiating it with ultraviolet light, yielding a triacetyl cellulose film with a hard coat layer. The triacetyl cellulose film with the hard coat layer formed thereon was introduced into a roll-to-roll sputtering deposition apparatus. While the film was running, bombardment (plasma treatment with Ar gas) was performed on the surface on which the hard coat layer was formed. A 3.5 nm silicon oxide layer was then formed as a primer layer. A 12 nm Nb2O5 layer, a 28 nm SiO2 layer, a 100 nm Nb2O5 layer, and an 85 nm SiO2 layer were then sequentially formed on top of that to produce a first transparent protective film (Film A) with an anti-reflection layer. The bombardment was performed at a pressure of 0.5 Pa. The silicon oxide primer layer was formed by sputtering using a Si target at a substrate temperature of -8°C, an argon flow rate of 300 sccm, and a pressure of 0.2 Pa. A Si target was used to deposit the SiO2 layer, and a Nb target was used to deposit the Nb2O5 layer. Deposition was carried out at a substrate temperature of -8°C, an argon flow rate of 200 sccm, and a pressure of 0.10 Pa. During deposition of the SiO2 and Nb2O5 layers, the amount of oxygen introduced was adjusted using plasma emission monitoring (PEM) control to maintain the deposition mode in the transition region. The moisture permeability of the first transparent protective film with an anti-reflection layer was measured in accordance with JIS K7129:2008 Appendix B, as mentioned above.

[0087] <Preparation of Polarizing Film with First Transparent Protective Film Having Antireflection Layer> A 20 μm thick acrylic adhesive layer was transferred to the side of the first transparent protective film having the antireflection layer obtained above, on which the antireflection layer was not formed, and laminated to the transparent protective film surface on the viewing side of the polarizing film with the adhesive layer obtained above, thereby producing a polarizing film with a first transparent protective film having an antireflection layer.

[0088] <Fabrication of pseudo image display panel> The polarizing film with the first transparent protective film having an anti-reflection layer obtained above was cut to a size of 150 x 45 mm so that the absorption axis of the polarizing film was parallel to the long side, and a glass plate (EG-XG, manufactured by Hiraoka Special Glass Manufacturing Co., Ltd., 165 x 50 mm, thickness 0.7 mm) was attached via an adhesive layer, and the resulting film was autoclaved at 50°C and 0.5 MPa for 15 minutes to produce a pseudo-image display panel.

[0089] <Evaluation of durability in high temperature environments> The pseudo image display panel obtained above was left to stand in a hot air oven at a temperature of 105°C for 240 hours, and the single-piece transmittance (ΔTs) was measured before and after heating. The single-piece transmittance was measured using a spectrophotometer (LPF-200, manufactured by Otsuka Electronics Co., Ltd.). The single-piece transmittance is a Y value corrected for visibility using a 2-degree visual field (C light source) according to JIS Z 8701-1982. The measurement wavelength was 380 to 780 nm (in 5 nm increments). ΔTs(%)=Ts 240 -Ts0 where Ts0 is the initial (before heating) single-piece transmittance, and Ts 240 is the single-piece transmittance after heating for 240 hours. ΔTs (%) is preferably 0% or more and 3% or less, and more preferably 0% or more and 2% or less. The results are shown in Table 1.

[0090] <Evaluation of durability in a humid and hot environment> The pseudo-image display panel obtained above was wrapped in water-soaked Texwipe (manufactured by Iris Corporation, product name "TEXWIPE"), placed in a plastic bag and sealed, and left to stand in a moist heat oven at 60°C and 95% RH for 100 hours.The appearance was then visually evaluated according to the following criteria. ◯: No peeling occurred between the polarizing film and the glass plate. △: Slight peeling occurred between the polarizing film and the glass plate. ×: Significant peeling occurred between the polarizing film and the glass plate.

[0091] <Example 2> A pseudo-image display panel was prepared in the same manner as in Example 1, except that a polarizing film with a first transparent protective film (Film B) having an anti-reflection layer was used, which was formed under the following conditions: an argon flow rate of 400 sccm and a pressure of 0.2 Pa when forming the SiO2 layer, and an argon flow rate of 1200 sccm and a pressure of 0.4 Pa when forming the Nb2O5 layer.

[0092] Example 3 A pseudo-image display panel was prepared in the same manner as in Example 1, except that a polarizing film with a first transparent protective film (Film C) having an anti-reflection layer was used, which was formed under the following conditions: an argon flow rate of 600 sccm and a pressure of 0.2 Pa for forming the SiO2 layer, and an argon flow rate of 1250 sccm and a pressure of 0.4 Pa for forming the Nb2O5 layer.

[0093] Example 4 A pseudo-image display panel was prepared in the same manner as in Example 1, except that a polarizing film with a first transparent protective film (Film D) having an anti-reflection layer was used, which was formed under the following conditions: an argon flow rate of 800 sccm and a pressure of 0.3 Pa for forming the SiO2 layer, and an argon flow rate of 1300 sccm and a pressure of 0.4 Pa for forming the Nb2O5 layer.

[0094] <Example 5> A pseudo-image display panel was produced in the same manner as in Example 3, except that in producing the polarizing film, no compound represented by general formula (2) was added to the cleaning bath, and in producing the polarizing film, the water-soluble radical scavenger represented by general formula (2) was added to both adhesives used in the production of the polarizing film in a weight ratio of 4:3 to the polyvinyl alcohol resin, and potassium hydroxide was added to the water-soluble radical scavenger in a molar ratio of 1:1 to the water-soluble radical scavenger to adjust the pH (neutralize) so as not to affect the curing reaction of the adhesive.

[0095] <Comparative Example 1> A pseudo-image display panel was prepared in the same manner as in Example 1, except that a polarizing film with a first transparent protective film (Film E) having an anti-reflection layer was used, which was formed under the following conditions: an argon flow rate of 1100 sccm and a pressure of 0.4 Pa for forming the SiO2 layer, and an argon flow rate of 1500 sccm and a pressure of 0.5 Pa for forming the Nb2O5 layer.

[0096] <Comparative Example 2> A pseudo-image display panel was produced in the same manner as in Example 1, except that the polarizing film was produced without adding the compound represented by general formula (2) to the cleaning bath.

[0097] <Comparative Example 3> A pseudo-image display panel was produced in the same manner as in Example 3, except that in the preparation of the polarizing film, a polyvinyl alcohol film having a thickness of 75 μm was immersed in a swelling bath (water washing) at 35° C. between rolls having different peripheral speed ratios for 30 seconds, and stretched to 2.2 times its original size in the conveying direction while swelling (swelling step), and the compound represented by general formula (2) was not added to the washing bath.

[0098] The pseudo image display panels of the examples and comparative examples obtained above were used to evaluate the durability in a high-temperature environment and the peeling in a humid and hot environment. The results are shown in Table 1.

[0099] [Table 1] [Explanation of symbols]

[0100] 1: Polarizing film 11: Polarizing film 12: First transparent protective film having an anti-reflection layer 13: Second transparent protective film 14: Third transparent protective film 20, 30: Pressure sensitive adhesive layer or adhesive layer 81:Transparent film 6: Anti-reflection layer 61, 62, 63, 64: Thin film 71: Hard coat layer 90: Image display cell 100: Image display panel

Claims

1. An image display panel comprising a first transparent protective film having an anti-reflection layer, a polarizing film, and an image display cell having a glass substrate as its outermost surface, provided in this order, Optionally, the polarizing film may have a layer adjacent to the polarizing film, The polarizing film has a thickness of 20 μm or less, the first transparent protective film having the antireflection layer has a moisture permeability of 10 g / (m 2 ·24 h) or less; The polarizing film has a second transparent protective film having a moisture permeability of 200 g / (m 2 ·24 h) or more bonded to the first transparent protective film side of the polarizing film having the antireflection layer, An image display panel, wherein the polarizing film and / or a layer adjacent to the polarizing film contains a water-soluble radical scavenger.

2. 2. The image display panel according to claim 1, wherein the polarizing film has a third transparent protective film attached to the polarizing film on the image display cell side.

3. 3. The image display panel according to claim 1, wherein the layer adjacent to the polarizing film is a pressure-sensitive adhesive layer, an adhesive layer, or a functional layer.

4. 3. The image display panel according to claim 1, wherein the anti-reflection layer is a layer made up of two or more thin films with different refractive indices.

5. 3. The image display panel according to claim 1, wherein the first transparent protective film having the antireflection layer comprises a transparent film, a hard coat layer, and the antireflection layer in this order.

Images