Composite polarizing plate and image display device

Abstract

The invention provides a composite polarizing plate and an image display device. Red discoloration of a polarizing plate is suppressed. A composite polarizing plate (10) is provided with a polarizing plate (30) having a polarizing plate (31) in which a dichroic pigment is adsorbed and oriented on a polyvinyl alcohol resin film, a first protective film (33) laminated on one surface of the polarizing plate (31), and a second protective film (34) laminated on the other surface of the polarizing plate (31). In the composite polarizing plate (10), an ammonia gas barrier layer (50) having an ammonia gas transmission concentration of 500 ppm or less is further laminated on a surface of the first protective film (33) opposite to the polarizer (31). In the composite polarizing plate (10), an adhesive layer (42) is further laminated on the surface of the second protective film (34) opposite to the polarizer (31).

Description

Technical Field

[0001] The present invention relates to a composite polarizing plate and an image display device. Background Art

[0002] As described in Patent Document 1, a phenomenon known to occur when a polarizing plate is placed in a high-temperature environment causes a red shift. This phenomenon is a phenomenon in which the transmittance increases at a long wavelength of approximately 700 nm, resulting in the polarizing plate being observed as red when arranged in a crossed Nicol configuration.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-152862 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] The present invention aims to suppress the occurrence of red discoloration in polarizing plates. The inventors have discovered a correlation between the contact of ammonia gas that has entered the polarizing plate from the outside with the polarizer and the occurrence of red discoloration.

[0008] Means for solving problems

[0009] The present invention includes the following inventions.

[0010] [1]

[0011] A composite polarizing plate comprises a polarizing plate having a polarizer formed by adsorbing and aligning a dichroic dye on a polyvinyl alcohol-based resin film, a first protective film laminated on one surface of the polarizer, and a second protective film laminated on the other surface of the polarizer.

[0012] An ammonia barrier layer having an ammonia permeation concentration of 500 ppm or less is further laminated on the surface of the first protective film opposite to the polarizer.

[0013] A pressure-sensitive adhesive layer is further laminated on the surface of the second protective film opposite to the polarizer.

[0014] [2]

[0015] The composite polarizing plate according to [1], wherein the ammonia gas barrier layer is a layer comprising at least one selected from the group consisting of a cyclic olefin resin film and an acrylic resin film.

[0016] [3]

[0017] The composite polarizing plate according to [1] or [2], wherein the polarizer and the first protective film, and the polarizer and the second protective film are laminated via an adhesive layer, and the adhesive layer contains at least one urea compound selected from urea, urea derivatives, thiourea, and thiourea derivatives.

[0018] [4]

[0019] The composite polarizing plate according to any one of [1] to [3], wherein the moisture permeability of the first protective film is 200 g / (m 2 24 hours) or less.

[0020] [5]

[0021] The composite polarizing plate according to any one of [1] to [4], wherein the first protective film and the ammonia barrier layer are laminated via a tacky adhesive layer having a thickness of 10 μm or less.

[0022] [6]

[0023] An image display device comprising a composite polarizing plate according to any one of [1] to [5] and an image display panel stacked together.

[0024] The image display panel is laminated on the surface of the second protective film opposite to the polarizer via the adhesive layer.

[0025] Effects of the Invention

[0026] According to the present invention, red discoloration of a polarizing plate can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic cross-sectional view showing a composite polarizing plate including a polarizing plate.

[0028] Figure 2 It is a schematic cross-sectional view showing an image display device including a composite polarizing plate. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of a composite polarizing plate and an image display device will be described.

[0030] Composite polarizing plate

[0031] like Figure 1 As shown, the composite polarizing plate 10 includes a polarizing plate 30, an ammonia barrier layer 50, and an adhesive layer 42. The ammonia barrier layer 50 is laminated on the polarizing plate 30, for example, via an adhesive layer 41. Hereinafter, the ammonia barrier layer may also be simply referred to as a barrier layer. The adhesive layer 42 is laminated on the surface of the polarizing plate 30 opposite to the surface on which the barrier layer 50 is laminated.

[0032] As will be described later, the composite polarizing plate 10 can be bonded to the image display panel 60 by attaching the adhesive layer 42 to the image display panel 60. Figure 2 The composite polarizing plate 10 can be used as an image display device 20 as shown. The composite polarizing plate 10 can be arranged on the viewing side of the image display panel 60. In the composite polarizing plate 10, the side close to the adhesive layer 42 is called the panel side, and the side close to the barrier layer 50 is called the viewing side.

[0033] Polarizing Plate

[0034] The polarizing plate 30 includes a polarizing plate 31 . The polarizing plate 30 includes a protective film for protecting the polarizing plate 31 .

[0035] like Figure 1 As shown in FIG. 3 , the polarizing plate 30 has a first protective film 33 laminated on one surface of a polarizer 31 via a lamination layer 32. Figure 1 As shown, the polarizing plate 30 has a second protective film 34 laminated on the other side of the polarizer 31 via a laminating layer 32. The first protective film 33 is a protective film laminated on the viewing side. The second protective film 34 is a protective film laminated on the panel side. The first protective film 33 and the second protective film 34 can be laminated using, for example, a roll laminator.

[0036] Polarizing Plate

[0037] The polarizer is a polarizer formed by adsorption and orientation of a dichroic pigment on a uniaxially stretched polyvinyl alcohol resin film. As the polyvinyl alcohol resin, for example, a resin obtained by saponifying a polyvinyl acetate resin can be used. The degree of saponification of the polyvinyl acetate resin is preferably 85 mol% or more, more preferably 90 mol% or more, and even more preferably 99 mol% or more.

[0038] Examples of polyvinyl acetate resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate and other copolymerizable monomers. Examples of other copolymerizable monomers include unsaturated carboxylic acids, olefins, vinyl ethers, and unsaturated sulfonic acids.

[0039] The degree of polymerization of the polyvinyl alcohol-based resin is preferably 1,000 or more and 10,000 or less, and more preferably 1,500 or more and 5,000 or less.

[0040] The polyvinyl alcohol-based resin may be modified. Examples of the modified polyvinyl alcohol-based resin include polyvinyl formal, polyvinyl acetal, and polyvinyl butyral modified with aldehydes.

[0041] Examples of the dichroic pigment include iodine and water-soluble dichroic dyes.

[0042] The thickness of the polarizer is not particularly limited, but is, for example, 1 μm or more, preferably 5 μm or more, more preferably 8 μm or more, and is 50 μm or less, preferably 30 μm or less.

[0043] The manufacturing method of the polarizer can adopt a well-known method. As this manufacturing method, for example, a polyvinyl alcohol-based resin film is used as the raw material film, and a swelling process, a dyeing process, a cross-linking process, a cleaning process, and a drying process are carried out in sequence. The swelling process is a treatment process in which the raw material film is swollen by immersing it in a swelling liquid. The dyeing process is a treatment process in which the film after the swelling process is immersed in a dyeing liquid containing a dichroic pigment so that the dichroic pigment is adsorbed and oriented on the film. The cross-linking process is a treatment process in which a cross-linking liquid is brought into contact with the film to perform a cross-linking treatment. Between each process, that is, before or after any one or more treatment processes or during the treatment process, a uniaxial stretching process can be implemented as a stretching process.

[0044] The crosslinking step is a treatment step performed for purposes such as water resistance through crosslinking, color adjustment (color correction), etc. The crosslinking treatment may be performed multiple times. When multiple crosslinking treatments are performed, the crosslinking treatments may be performed multiple times for the purpose of water resistance through crosslinking, or multiple times for the purpose of color adjustment. Preferably, at least one crosslinking treatment for the purpose of water resistance through crosslinking and at least one crosslinking treatment for the purpose of color adjustment are performed. More preferably, the crosslinking treatment for the purpose of color adjustment is performed after the crosslinking treatment for the purpose of water resistance through crosslinking is performed.

[0045] It should be noted that the term "at least one" as used in this specification refers to "one or more" of the desired options. For example, if the number of options is three or more, the term "at least one" as used in this specification means "only one option" or "a combination of two or more options."

[0046] <Protective film>

[0047] The protective film is not particularly limited, and various transparent protective films that can be used in polarizing plates can be used. As the material constituting the protective film, for example, a thermoplastic resin with excellent transparency, mechanical strength, thermal stability, moisture barrier properties, isotropy, etc. can be used. Examples of the above-mentioned thermoplastic resins include cellulose ester resins such as triacetylcellulose, 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 having a ring system or norbornene structure (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. In addition, the protective film can use a cured layer formed from a thermosetting resin such as a (meth)acrylic resin, urethane resin, acrylic urethane resin, epoxy resin, silicone resin, or a UV-curable resin. Among them, cellulose ester resins, polycarbonate resins, (meth)acrylic resins, cyclic polyolefin resins, and polyester resins are suitable.

[0048] The surface of the protective film not bonded with the polarizer may be provided with a functional layer such as a hard coating layer, an anti-reflection layer, an anti-adhesion layer, a diffusion layer, or an anti-glare layer. It should be noted that the functional layers such as the hard coating layer, the anti-reflection layer, the anti-adhesion layer, the diffusion layer, and the anti-glare layer may be provided on the protective film itself or as a separate layer from the protective film.

[0049] The surface of the protective film to be bonded to the polarizer and the surface of the polarizer to be bonded to the protective film may be subjected to a surface treatment, or both surfaces thereof. Examples of the surface treatment include corona treatment, plasma treatment, primer treatment, and saponification treatment.

[0050] The thickness of the protective film is not particularly limited. From the perspective of handleability in the manufacturing process, it is 1 μm or more, preferably 10 μm or more, and more preferably 30 μm or more. From the perspective of thin film polarizing plates, it is 200 μm or less, preferably 100 μm or less, more preferably 80 μm or less, and even more preferably 60 μm or less.

[0051] The moisture permeability of the protective film is not particularly limited. The moisture permeability of the first protective film 33 on the observation side of the protective film in an environment of a temperature of 40° C. and a relative humidity of 90% is, for example, 350 g / (m 2 · 24 hours) or less. The above-mentioned moisture permeability is, for example, 50g / (m 2 The moisture permeability can be measured according to the moisture permeability test (cup method) of JIS Z0208.

[0052] The moisture permeability is preferably 50 g / (m 2 24 hours) or more and 350g / (m 2 ·24 hours) or less, more preferably 80g / (m 2 24 hours) or more and 300g / (m 2 ·24 hours) or less, more preferably 100g / (m 2 24 hours) or more and 200g / (m 2 24 hours) or less.

[0053] The ammonia permeation concentration of the protective film is not particularly limited. The ammonia permeation concentration of the first protective film 33 on the observation side of the protective film can be 1000 ppm or less. The ammonia permeation concentration of the first protective film 33 can be 800 ppm or less, 100 ppm or greater, or 300 ppm or greater. The ammonia permeation concentration, which correlates with the gas permeability of the first protective film 33, can be measured using the measurement method described below.

[0054] <Lamination layer>

[0055] The lamination layer 32 may be a pressure-sensitive adhesive layer or an adhesive layer. The lamination layer 32 is preferably an adhesive layer.

[0056] As the adhesive composition forming the adhesive layer, any conventionally known adhesive composition having excellent optical transparency can be used without particular limitation. For example, an adhesive composition having a base polymer such as an acrylic resin, a urethane resin, a silicone resin, or a polyvinyl ether resin can be used. Among them, an adhesive composition having an acrylic resin as a base polymer, which exhibits excellent transparency, adhesion, removability, weather resistance, and heat resistance, is particularly suitable. The adhesive composition may further contain a crosslinking agent, a silane compound, an antistatic agent, and the like.

[0057] As the adhesive composition forming the adhesive layer, various adhesive compositions that can be used for polarizing plates can be applied, including aqueous adhesive compositions obtained by dissolving or dispersing a curable adhesive component in water, and active energy ray-curable adhesive compositions containing an active energy ray-curable compound. Examples of aqueous adhesive compositions include isocyanate adhesives, polyvinyl alcohol adhesives, gelatin adhesives, vinyl latex adhesives, and aqueous polyester adhesives. The adhesive composition is preferably an aqueous solution obtained by dissolving the adhesive component in water. The solid content concentration of the adhesive composition is preferably 0.5 to 20% by mass, and more preferably 1 to 15% by mass.

[0058] When a polyvinyl alcohol resin is used as the main component of the adhesive composition, the polyvinyl alcohol resin may be a polyvinyl alcohol resin such as partially saponified polyvinyl alcohol, completely saponified polyvinyl alcohol, or a modified polyvinyl alcohol resin. Examples of the modified polyvinyl alcohol resin include carboxyl-modified polyvinyl alcohol resins and acetoacetyl-modified polyvinyl alcohol resins.

[0059] From the viewpoint of adhesiveness, the average degree of polymerization of the polyvinyl alcohol-based resin (preferably an acetoacetyl-modified polyvinyl alcohol-based resin) is preferably 100 to 5500, and more preferably 500 to 4500.

[0060] The degree of saponification of the polyvinyl alcohol-based resin (preferably an acetoacetyl-modified polyvinyl alcohol-based resin) is generally 80 mol % to 100 mol %, and preferably 85 mol % or more.

[0061] From the viewpoint of adhesion, the degree of modification (modification amount) of the acetoacetyl group in the acetoacetyl-modified polyvinyl alcohol-based resin is generally 0.1 mol % to 40 mol %, preferably 0.5 mol % to 20 mol %.

[0062] Among water-based adhesive compositions, polyvinyl alcohol-based adhesive compositions are preferred, and acetoacetyl-modified polyvinyl alcohol-based adhesive compositions are more preferred. That is, the lamination layer 32 is preferably a cured layer of a water-based adhesive composition containing a polyvinyl alcohol-based resin.

[0063] In addition to the aforementioned water-based adhesive compositions, adhesive compositions also include active energy ray-curable adhesive compositions such as UV-curable adhesive compositions and electron beam-curable adhesive compositions. Examples of active energy ray-curable adhesive compositions include (meth)acrylate adhesives. Examples of curable components in (meth)acrylate adhesives include compounds containing (meth)acryloyl groups and compounds containing vinyl groups. Examples of compounds containing (meth)acryloyl groups 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-containing (meth)acrylates; and epoxy-containing (meth)acrylates such as glycidyl (meth)acrylate. (Meth)acrylate adhesives can contain nitrogen-containing monomers such as hydroxyethyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-ethoxymethyl (meth)acrylamide, (meth)acrylamide, and (meth)acryloylmorpholine. (Meth)acrylate adhesives can also contain multifunctional monomers such as tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecane dimethanol diacrylate, cyclic trimethylolpropane formal acrylate, dioxanediol diacrylate, and EO-modified diglycerol tetraacrylate as crosslinking components. Furthermore, compounds containing epoxy or oxetane groups can also be used as cationic polymerization-curable adhesives. The epoxy 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.

[0064] The active energy ray-curable adhesive composition may contain appropriate additives as needed. Examples of the additives include coupling agents such as silane coupling agents and titanium coupling agents, adhesion promoters such as ethylene oxide, ultraviolet absorbers, degradation inhibitors, dyes, processing aids, ion traps, antioxidants, tackifiers, fillers, plasticizers, leveling agents, foaming inhibitors, antistatic agents, heat stabilizers, and hydrolysis stabilizers.

[0065] The adhesive composition can be applied to either the protective film side or the polarizer side, or to both. After lamination, a drying step is performed to form an adhesive layer consisting of the applied dried layer. After the drying step, ultraviolet light or electron beam irradiation can be performed as needed.

[0066] The adhesive composition forming the lamination layer 32 may contain a urea compound. Hereinafter, the urea compound and other components that may be contained in the adhesive composition will be described.

[0067] Urea compounds

[0068] The urea compound is, for example, at least one selected from urea, urea derivatives, thiourea, and thiourea derivatives. One urea compound may be used alone or in combination of two or more. Urea compounds include water-soluble urea compounds and poorly water-soluble urea compounds, and any urea compound may be used. When using a poorly water-soluble urea compound in a water-soluble adhesive, it is preferable to design a dispersion method after forming the adhesive layer so as not to cause an increase in haze. Urea is preferably the urea compound.

[0069] (Urea derivatives)

[0070] Urea derivatives are compounds in which at least one of the four hydrogen atoms in the urea molecule is replaced by a substituent. In this case, the substituent is not particularly limited, but preferably comprises a carbon atom, a hydrogen atom, and an oxygen atom.

[0071] Specific examples of urea derivatives include monosubstituted urea, such as methyl urea, ethyl urea, propyl urea, butyl urea, isobutyl urea, N-octadecyl urea, 2-hydroxyethyl urea, hydroxyurea, acetyl urea, allyl urea, 2-propynyl urea, cyclohexyl urea, phenyl urea, 3-hydroxyphenyl urea, (4-methoxyphenyl) urea, benzyl urea, benzoyl urea, o-tolyl urea, and p-tolyl urea.

[0072] Examples of the disubstituted urea include 1,1-dimethylurea, 1,3-dimethylurea, 1,1-diethylurea, 1,3-diethylurea, 1,3-bis(hydroxymethyl)urea, 1,3-tert-butylurea, 1,3-dicyclohexylurea, 1,3-diphenylurea, 1,3-bis(4-methoxyphenyl)urea, 1-acetyl-3-methylurea, 2-imidazolidinone (ethylene urea), and tetrahydro-2-pyrimidinone (propylene urea).

[0073] Examples of the tetrasubstituted urea include tetramethylurea, 1,1,3,3-tetraethylurea, 1,1,3,3-tetrabutylurea, 1,3-dimethoxy-1,3-dimethylurea, 1,3-dimethyl-2-imidazolidinone, and 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone.

[0074] (Thiocarbamide derivatives)

[0075] Thiourea derivatives are compounds in which at least one of the four hydrogen atoms in the thiourea molecule is replaced by a substituent. In this case, the substituent is not particularly limited, but preferably contains a carbon atom, a hydrogen atom, and an oxygen atom.

[0076] Specific examples of the thiourea derivative include monosubstituted thiourea, such as N-methylthiourea, ethylthiourea, propylthiourea, isopropylthiourea, 1-butylthiourea, cyclohexylthiourea, N-acetylthiourea, N-allylthiourea, (2-methoxyethyl)thiourea, N-phenylthiourea, (4-methoxyphenyl)thiourea, N-(2-methoxyphenyl)thiourea, N-(1-naphthyl)thiourea, (2-pyridyl)thiourea, o-tolylthiourea, and p-tolylthiourea.

[0077] Examples of the disubstituted thiourea include 1,1-dimethylthiourea, 1,3-dimethylthiourea, 1,1-diethylthiourea, 1,3-diethylthiourea, 1,3-dibutylthiourea, 1,3-diisopropylthiourea, 1,3-dicyclohexylthiourea, N,N-diphenylthiourea, N,N'-diphenylthiourea, 1,3-di(o-tolyl)thiourea, 1,3-di(p-tolyl)thiourea, 1-benzyl-3-phenylthiourea, 1-methyl-3-phenylthiourea, N-allyl-N'-(2-hydroxyethyl)thiourea, and ethylenethiourea.

[0078] Examples of the trisubstituted thiourea include trimethylthiourea, and examples of the tetrasubstituted thiourea include tetramethylthiourea and 1,1,3,3-tetraethylthiourea.

[0079] The content of the urea compound in the adhesive composition is preferably within the following ranges, for example. For example, when the adhesive composition is a water-based adhesive containing a polyvinyl alcohol resin, the content of the urea compound is preferably 0.1 parts by mass to 400 parts by mass, more preferably 1 part by mass to 200 parts by mass, and even more preferably 3 parts by mass to 100 parts by mass, relative to 100 parts by mass of the polyvinyl alcohol resin. The addition of a urea compound can inhibit polyene formation in high-temperature environments, but this effect may be insufficient when the urea compound content is less than 0.1 parts by mass relative to 100 parts by mass of the polyvinyl alcohol resin. When the urea compound content exceeds 400 parts by mass relative to 100 parts by mass of the polyvinyl alcohol resin, the urea compound may precipitate, resulting in adverse effects such as increased haze.

[0080] [Other ingredients]

[0081] The adhesive composition may contain an organic solvent. From the perspective of miscibility with water, the organic solvent is preferably an alcohol, and among alcohols, methanol or ethanol is more preferred. The concentration of the organic solvent in the aqueous adhesive is preferably 10% by mass or more and 70% by mass or less, more preferably 15% by mass or more and 60% by mass or less, and further preferably 20% by mass or more and 60% by mass or less. By setting the concentration of the organic solvent to 10% by mass or more, it is easier to suppress the polyeneization of the PVA-based resin under high temperature environments. In addition, by setting the content of the organic solvent to 70% by mass or less, it is possible to suppress the deterioration of the hue. Some of the above-mentioned urea derivatives have low solubility in water, but on the other hand, they have sufficient solubility in alcohol. In this case, dissolving the urea compound in alcohol to prepare an alcohol solution of the urea compound is also one of the preferred methods, and then adding the alcohol solution of the urea compound to the PVA aqueous solution to prepare the adhesive.

[0082] Water-based adhesive compositions may contain a crosslinking agent. Crosslinking agents typically include compounds containing at least two functional groups per molecule that are reactive with the polymer or other components that comprise the adhesive. Examples include alkylenediamines, isocyanates, epoxies, aldehydes, amino-formaldehydes such as methylolurea and methylolmelamine, glyoxal, and glyoxal derivatives. The amount of crosslinking agent added to the adhesive is typically approximately 5 to 60 parts by mass per 100 parts by mass of the polymer or other components that comprise the adhesive.

[0083] The thickness of the laminating layer 32 is not particularly limited. For example, when using a water-based adhesive composition, the thickness is preferably about 1 to 5000 nm, more preferably about 10 to 1000 nm. For example, when using an active energy ray-curable adhesive composition, the thickness is preferably about 0.1 to 10 μm, more preferably about 0.5 to 5 μm. For example, when using an adhesive composition, the thickness is generally preferably 0.1 to 30 μm, more preferably 3 to 30 μm, and even more preferably 5 to 25 μm.

[0084] <Ammonia barrier>

[0085] The ammonia barrier layer 50 is laminated on the surface of the first protective film 33 opposite to the polarizer 31 .

[0086] The ammonia permeation concentration of the barrier layer 50 is 500 ppm or less. The ammonia permeation concentration of the barrier layer 50 is preferably 220 ppm or less, and more preferably 140 ppm or less. The lower the ammonia permeation concentration of the barrier layer 50, the more effectively reddening of the polarizing plate can be suppressed. The ammonia permeation concentration, which is related to the gas permeability of the barrier layer 50, can be measured using the measurement method described below.

[0087] The other configurations of the barrier layer 50 are not limited as long as the ammonia gas permeation concentration thereof is within the above-specified range.

[0088] Examples of the barrier layer 50 include layers formed from films such as triacetyl cellulose film, acrylic resin film, and cyclic olefin resin film. The triacetyl cellulose film may be provided with a hard coat layer. Surface treatment may be applied to either or both surfaces of the film. Examples of surface treatments include corona treatment, plasma treatment, primer treatment, and saponification treatment.

[0089] The barrier layer 50 may be a single layer or a multilayer structure of two or more layers. For example, in the case of a multilayer barrier layer 50 composed of two or more films, a tacky adhesive layer interposed between the films may be included in the barrier layer 50. This tacky adhesive layer may be, for example, the same tacky adhesive layer or adhesive layer as exemplified in this specification. In the case of a multilayer barrier layer 50 composed of films, only one type of film may be used, or a combination of two or more types of films may be used.

[0090] The barrier layer 50 is preferably a layer including at least one selected from the group consisting of a cyclic olefin-based resin film and an acrylic resin film.

[0091] There is no particular limitation on the thickness of the barrier layer 50. The thickness of the barrier layer 50 is, for example, 5 μm to 100 μm, preferably 20 μm to 80 μm, and more preferably 13 μm to 50 μm.

[0092] The moisture permeability of the barrier layer 50 is not particularly limited. For example, the moisture permeability of the barrier layer 50 is 2 g / (m 2 24 hours) or more and 450g / (m 2 ·24 hours) or less, preferably 2g / (m 2 24 hours) or more and 350g / (m 2 ·24 hours) or less, more preferably 2g / (m 2 24 hours) or more and 100g / (m 2 · 24 hours) or less. The moisture permeability of the barrier layer 50 may be 5g / (m 2 The moisture permeability can be measured according to the moisture permeability test (cup method) of JIS Z0208.

[0093] <Adhesive layer>

[0094] The adhesive layer 41 is in direct contact with, for example, the first protective film 33 and the ammonia barrier layer 50 .

[0095] The adhesive layer 41 may be a pressure-sensitive adhesive layer or an adhesive layer. The pressure-sensitive adhesive layer or adhesive layer constituting the pressure-sensitive adhesive layer 41 may be appropriately selected from the pressure-sensitive adhesive layers or adhesive layers described as the lamination layer 32 .

[0096] The thickness of the adhesive layer 41 is not particularly limited, and is, for example, 0.015 μm or more, preferably 25 μm or less. The thickness of the adhesive layer 41 is preferably 0.015 μm or more and 15 μm or less, more preferably 0.015 μm or more and 10 μm or less, and most preferably 3 μm or more and 8 μm or less.

[0097] <Adhesive layer>

[0098] The adhesive layer 42 is in direct contact with the second protective film 34, for example. The adhesive layer 42 may be laminated via another layer laminated on the surface of the second protective film 34 on the opposite side to the polarizer 31.

[0099] The adhesive composition forming the adhesive layer 42 can be appropriately selected from the adhesive compositions described as the lamination layer 32. The thickness of the adhesive layer 42 is not particularly limited, and is, for example, about 1 to 100 μm, preferably about 2 to 50 μm.

[0100] <Image Display Device>

[0101] Figure 2 An example of the image display device 20 is shown.

[0102] like Figure 2 As shown, the composite polarizing plate 10 can be used in an image display device 20 .

[0103] The image display device 20 includes, for example, an image display panel 60 . In the image display device 20 , the image display panel 60 is laminated on the surface of the second protective film 34 opposite to the polarizing plate 31 via the adhesive layer 42 .

[0104] It should be noted that, in the composite polarizing plate 10 before being bonded to the image display panel 60, a film having a release layer may be laminated on the adhesive layer 42 of the composite polarizing plate 10. The film having the release layer is peeled off and removed during the manufacture of the image display device 20. By removing the film having the release layer, the exposed adhesive layer 42 can be bonded to the image display panel 60. The release layer may be any known release layer, for example, a layer formed by applying a release agent such as a fluorine compound or an organosilicon compound to a base film.

[0105] The image display device 20 includes, for example, a transparent member 70. In the image display device 20, for example, the transparent member 70 is laminated on the barrier layer 50 of the composite polarizing plate 10 via the front bonding layer 43.

[0106] The front laminating layer 43 is, for example, an adhesive layer. As the adhesive composition forming the adhesive layer, one can appropriately select from the adhesive compositions described as the laminating layer 32 .

[0107] Examples of the transparent member 70 include a front transparent plate (window layer) and a touch panel. The front transparent plate can be a transparent plate with appropriate mechanical strength and thickness. Examples of such a transparent plate include a transparent resin plate such as an acrylic resin or a polycarbonate resin, a glass plate, or a laminate thereof. The touch panel can be a variety of touch panels, such as resistive, capacitive, optical, and ultrasonic touch panels, as well as glass plates and transparent resin plates with touch sensor functionality.

[0108] The image display panel 60 is not particularly limited, and examples thereof include a liquid crystal display panel, an organic electroluminescent (organic EL) display panel, an inorganic electroluminescent (inorganic EL) display panel, a plasma display panel, and an electric field emission display panel.

[0109] Examples of applications of image display devices include televisions, personal computers, mobile phones, tablet terminals, and other mobile devices, as well as in-vehicle applications. Specific examples of in-vehicle applications include car navigation systems, speedometers, air-conditioning touch panels, backup monitors, and rearview cameras.

[0110] <Effects of this embodiment>

[0111] There is a problem with the phenomenon of red discoloration caused by the polarizing plate being placed in a high temperature environment. The more easily ammonia gas from the outside penetrates into the polarizing plate, the more likely the red discoloration is to occur.

[0112] The composite polarizing plate and image display device of this embodiment include an ammonia barrier layer with an ammonia permeability concentration of 500 ppm or less on the viewing side relative to the polarizing plate. This prevents ammonia gas, which is present or generated externally (i.e., on the viewing side relative to the polarizing plate), from entering the polarizing plate. This also suppresses the occurrence of red discoloration. Even when exposed to high temperatures, the composite polarizing plate and image display device of this embodiment are less susceptible to red discoloration.

[0113] Composite polarizing plates and image displays that are less susceptible to reddening even when exposed to high temperatures can be suitable for applications that are sometimes exposed to high temperatures for extended periods. For example, in-vehicle image displays such as car navigation systems and backup cameras are sometimes exposed to high temperatures for extended periods. The composite polarizing plates and image displays of this embodiment can also be suitable for in-vehicle applications.

[0114] In this embodiment, “under a high temperature environment” means an environment of 100° C. or higher, for example, 105° C. or higher. Also, “for a long time” means 100 hours or more, for example, 120 hours.

[0115] The source of external ammonia gas is not particularly limited, and examples of external ammonia gas include ammonia gas present in the air and ammonia gas generated in the storage, transportation, and use environments of composite polarizing plates and image display devices.

[0116] Example

[0117] The composite polarizing plate and the image display device will be described in further detail based on the following examples. It should be noted that the composite polarizing plate and the image display device are not limited to the configurations described in the examples.

[0118] <Measurement of Moisture Permeability of Films and Film Laminates>

[0119] The moisture permeability of the film and the laminate of the films used for producing the composite polarizing plate was measured at a temperature of 40° C. and a relative humidity of 90% in accordance with the moisture permeability test (cup method) of JIS Z0208.

[0120] <Measurement of Ammonia Permeation Concentration of Membranes and Membrane Laminates>

[0121] The ammonia permeation concentration of the film used in the production of the composite polarizing plate was measured by the following measurement method. The ammonia permeation concentration of the laminated product of the film used in the production of the composite polarizing plate was measured by replacing the film in the following measurement method with the laminated product.

[0122] Add 0.07 ml of 10% ammonia solution to the cup of the moisture permeability test (cup method) according to JIS L1099, and process the cup to a 28.26 cm2 area. 2 The cup is covered with a film. Next, the film is pressed with an O-ring, and the butterfly nut is tightened to secure the cup and ring. Next, the cup is inserted into an aluminum vapor-deposited bag (1 liter capacity), and the opening of the bag is sealed by heat sealing. After standing at 23°C for 2 hours, a gas detection tube manufactured by Gastec Co., Ltd. is inserted into the aluminum vapor-deposited bag to measure the ammonia concentration inside the bag. The ammonia concentration inside the aluminum vapor-deposited bag represents the concentration of ammonia that has leaked out of the cup after permeating the film.

[0123] (Manufacturing Example 1: Preparation of Polarizing Plate)

[0124] A 30μm-thick polyvinyl alcohol-based resin film was immersed in pure water at 21.5°C for 79 seconds (swelling step), then immersed in a 23°C aqueous solution containing 1.0 mM iodine at a mass ratio of 2 / 2 / 100 for 151 seconds (dyeing step). The film, drawn from this aqueous solution, was then immersed in a 68.5°C aqueous solution containing a mass ratio of 2.5 / 4 / 100 for 76 seconds (first crosslinking step). The film, drawn from this aqueous solution, was then immersed in a 45°C aqueous solution containing a mass ratio of 3 / 5.5 / 0.6 / 100 for 11 seconds (second crosslinking step, metal ion treatment step). The film, drawn from this aqueous solution, was then immersed in a cleaning solution for washing (cleaning step). The film, drawn from the cleaning solution, was then dried at 38°C (drying step), resulting in a 12μm-thick polarizer in which iodine was adsorbed and oriented on the polyvinyl alcohol. Stretching was mainly performed in the dyeing step and the first crosslinking step, and the total stretching ratio was 5.85. The thickness of the obtained polarizing plate was measured using a digital micrometer "MH-15M" manufactured by Nikon Corporation.

[0125] (Manufacturing Example 2: Preparation of Adhesive Composition)

[0126] 50 g of an acetoacetyl-modified polyvinyl alcohol-based resin (manufactured by Mitsubishi Chemical Co., Ltd.: GOHSEN XZ-410) was dissolved in 950 g of pure water, and the mixture was heated at 90° C. for 2 hours and then cooled to room temperature to obtain an acetoacetyl-modified polyvinyl alcohol-based resin solution.

[0127] To the resulting acetoacetyl-modified polyvinyl alcohol-based resin solution, maleic acid, a 40% by mass solution of glyoxal, urea, and pure water were blended in the amounts shown in Table 1 below to prepare Adhesive Composition 1. Separately, to the resulting acetoacetyl-modified polyvinyl alcohol-based resin solution, maleic acid, a 40% by mass solution of glyoxal, and pure water were blended in the amounts shown in Table 1 below to prepare Adhesive Composition 2.

[0128] [Table 1]

[0129]

[0130] Polarizing Plate Production

[0131] Prepare the following membranes.

[0132] Film F1: Saponified triacetyl cellulose film with a hard coat layer (trade name "40FJCHCN-LMP" manufactured by Toppan Printing Co., Ltd., triacetyl cellulose film thickness: 40 μm, hard coat layer thickness: 7 μm). Moisture permeability: 200 g / (m2 ·24 hours), the ammonia permeation concentration is 400ppm.

[0133] Film F2: A laminated retardation film described in International Publication No. 2022 / 158482

[0147] . This laminated retardation film comprises a liquid crystal layer (first retardation layer) and a cycloolefin polymer film (second retardation layer).

[0134] Film F3: acrylic resin film (manufactured by Toyo Kohan Co., Ltd.: product name "HX-40NE"). Thickness: 40 μm. Water vapor permeability: 60 g / (m 2 ·24 hours), the ammonia permeation concentration is 10ppm.

[0135] Film F4: Cycloolefin polymer film (thickness 23 μm, manufactured by ZEON Corporation, Japan). Water vapor permeability 6 g / (m 2 ·24 hours), the ammonia permeation concentration was 220ppm.

[0136] (Manufacturing Example 3: Preparation of Polarizing Plates 1 and 2)

[0137] On one side of the polarizer manufactured in Manufacturing Example 1, the film F1 was laminated with the side without the hard coat layer as the polarizer side via the adhesive composition 1 prepared in Manufacturing Example 2. In addition, on the other side of the polarizer, the first phase difference layer of the film F2 was laminated as the polarizer side via the adhesive composition 1 prepared in Manufacturing Example 2 so that the slow axis of the second phase difference layer was parallel to the absorption axis of the polarizer, and the film was laminated using a roll laminator. Then, it was dried at 75°C for 8 minutes to obtain a polarizing plate 1. The film F1 and film F2 laminated on the polarizer correspond to protective films for protecting the polarizer. It should be noted that the thickness of the adhesive layer formed by the adhesive composition 1 after drying was 80nm.

[0138] Polarizing plate 2 was produced in the same manner as polarizing plate 1 except that adhesive composition 1 was replaced with adhesive composition 2. The thickness of the adhesive layer formed from adhesive composition 2 after drying was 80 nm.

[0139] (Manufacturing Example 4: Preparation of a PSA Sheet Having a PSA Layer)

[0140] Adhesive sheet A: A sheet comprising a commercially available sheet of acrylic adhesive layer A with a 38 μm polyethylene terephthalate (PET) film with a release agent on both sides. Adhesive layer A had a thickness of 5 μm and a storage elastic modulus of 0.14 MPa.

[0141] Adhesive sheet B: A sheet having a 38 μm PET film with a release agent on both sides of a commercially available sheet-shaped acrylic adhesive layer B. The adhesive layer B had a thickness of 25 μm and a storage elastic modulus of 0.06 MPa.

[0142] (Example 1: Preparation of Optical Layered Body 1)

[0143] One of the release-adhesive PET films in adhesive sheet A was peeled off to expose adhesive layer A. This adhesive layer A was then applied to the film F1 side of the polarizing plate 1 prepared above, i.e., the exposed hard coat surface. Next, film F3 (acrylic resin film) was applied to the adhesive layer A exposed by peeling off the other release-adhesive PET film in adhesive sheet A. In this manner, film F3 (acrylic resin film) was laminated onto the film F1 side of the polarizing plate 1 via adhesive layer A. Next, one of the release-adhesive PET films in adhesive sheet B was peeled off to expose adhesive layer B. This adhesive layer B was then applied to the film F2 side of the polarizing plate 1, thereby producing an optical laminate 1 with adhesive layer B laminated onto the film F2 side of the polarizing plate 1. The resulting optical laminate 1 had a layer structure of "film F3 (acrylic resin film) / adhesive layer A / polarizing plate 1 / adhesive layer B / PET film with release agent." In the above and following layer structures, " / " indicates that the layers preceding and following the " / " are directly in contact. The film F1, the first protective film laminated on the surface opposite the polarizer of the polarizing plate 1, corresponds to the ammonia barrier layer. Specifically, the film F3 corresponds to the ammonia barrier layer. The laminate obtained by peeling and removing the PET film with a release agent from the optical layered body 1 and the optical layered bodies 2 to 6 described below corresponds to the composite polarizing plate.

[0144] (Example 2: Preparation of Optical Layered Body 2)

[0145] An optical layered body 2 was produced in the same manner except that the film F3 of the optical layered body 1 produced above was replaced with the film F4 and the bonding surface of the film F4 was subjected to a corona treatment. In the optical layered body 2, the film F4 served as an ammonia gas barrier layer.

[0146] (Example 3: Preparation of Optical Layered Body 3)

[0147] Optical layered body 3 was produced in the same manner except that film F3 of the optical layered body 1 produced above was replaced with film F1 and the surface of film F1 not laminated with the hard coat layer was used as the bonding surface with adhesive layer A. In optical layered body 3, film F1 served as an ammonia barrier layer.

[0148] (Example 4: Preparation of Optical Layered Body 4)

[0149] An optical layered body 4 was produced in the same manner except that the polarizing plate 1 of the optical layered body 1 produced above was replaced with the polarizing plate 2. In the optical layered body 4, the film F3 served as an ammonia gas barrier layer.

[0150] (Preparation of a laminate of film F4)

[0151] Two sheets of the above-mentioned film F4 were bonded together via the adhesive sheet A to prepare a two-sheet laminate (film F4 2). Separately, three sheets of the above-mentioned film F4 were bonded together via the adhesive sheet A to prepare a three-sheet laminate (film F4 3). It should be noted that when the films F4 were bonded together with the adhesive sheet A, the surface of the film F4 bonded to the adhesive sheet A was subjected to a corona treatment. 2) In the middle, the moisture permeability is 5g / (m 2 ·24 hours), the ammonia permeation concentration is 100ppm. For the 3-sheet laminate (membrane F4 3) For moisture permeability, it is 3g / (m 2 ·24 hours), the ammonia permeation concentration is 40ppm.

[0152] (Example 5: Preparation of Optical Layered Body 5)

[0153] The film F3 of the optical laminate 1 produced above was replaced with two laminated products (film F4 2) The two laminated products (film F4 2) was subjected to corona treatment on the surface to be bonded to the polarizing plate 1, an optical laminate 5 was produced in the same manner. In the optical laminate 5, two laminated products (film F4) having a multilayer structure 2) It is an ammonia barrier layer.

[0154] (Example 6: Preparation of Optical Layered Body 6)

[0155] The film F3 of the optical laminate 1 produced above was replaced with a three-layer laminate (film F4 3) The three-layered product (film F4 3) was subjected to corona treatment on the surface to be bonded to the polarizing plate 1, an optical laminate 6 was produced in the same manner. In the optical laminate 6, three laminated products (film F4) having a multilayer structure 3) It is an ammonia barrier layer.

[0156] (Comparative Example 1: Preparation of Optical Layered Body 7)

[0157] One of the PET films with a release agent in the adhesive sheet B was peeled off to expose the adhesive layer B, and the adhesive layer B was bonded to the film F2 of the polarizing plate 1 prepared above, thereby producing an optical laminate 7 in which the adhesive layer B was laminated on the film F2 of the polarizing plate 1. The resulting optical laminate had a layer structure of "polarizing plate 1 / adhesive layer B / PET film with a release agent."

[0158] <Ammonia exposure test>

[0159] The optical laminate 1 was cut into a size of 40 mm × 35 mm so that the absorption axis was parallel to the long side. Next, the PET film with the release agent was peeled off, and a 50 mm × 40 mm alkali-free glass ("EAGLE XG" manufactured by Corning) was bonded to the surface of the adhesive layer B to obtain a laminate (1) with a glass plate for evaluation. The obtained laminate (1) with a glass plate for evaluation had a layer structure of "film F3 (acrylic resin film) / adhesive layer A / polarizing plate 1 / adhesive layer B / glass plate". Except that optical laminates 2 to 7 were used instead of optical laminate 1, the same operation as above was performed to obtain laminates (2) to (7) with glass plates for evaluation.

[0160] For the laminated bodies (1) to (7) with glass plates, the temperature was 50°C and the pressure was 5 kgf / cm 2 The autoclave treatment was carried out at (490.3 kPa) for 15 minutes to prepare evaluation samples (A1) to (A7).

[0161] The cross transmittance of evaluation samples (A1) to (A7) at a wavelength of 700 nm was measured using a spectrophotometer with an integrating sphere (V-7100 manufactured by JASCO Corporation). The cross transmittance was 0.01% or less in all cases.

[0162] Next, each evaluation sample and 0.07 ml of a 10% ammonia solution were placed in a 500 ml sealed plastic bottle and placed in a 60°C environment for 120 hours. The evaluation samples were removed, and their crossed transmittance was measured using a spectrophotometer with an integrating sphere (JASCO Corporation, V-7100). The results are shown in Table 2. The ammonia concentration in the sealed plastic bottle during this test was 20,000 ppm.

[0163] [Table 2]

[0164]

[0165] As shown in Table 2, it was confirmed that the lower the ammonia gas permeation concentration of the barrier layer, the more the increase in the cross transmittance at a wavelength of 700 nm after the evaluation sample was exposed to ammonia gas was suppressed. In other words, the relationship was confirmed that the easier the ammonia gas permeation, the more likely the red discoloration was to occur.

[0166] <High temperature durability test>

[0167] (Manufacture of analog image display device (1) with front panel)

[0168] The optical laminate 1 obtained in Example 1 was cut into a size of 90 mm × 100 mm so that the absorption axis was parallel to the long side. The PET film with the release agent was then peeled off, and a 100 mm × 100 mm piece of alkali-free glass ("EAGLE XG" manufactured by Corning) was bonded to the surface of the adhesive layer B to obtain a laminate (1) with a glass plate.

[0169] Next, a 100 mm × 100 mm alkali-free glass ("EAGLE XG" manufactured by Corning) was bonded to the surface of the laminate (1) with the glass plate not bonded to the glass plate via a 250 μm thick adhesive layer. 2 The simulated image display device (1) with a front panel was produced by autoclaving at 490.3 kPa for 15 minutes. The simulated image display device (1) with a front panel thus obtained had a layer structure of "glass plate / adhesive layer / film F3 (acrylic resin film) / adhesive layer A / polarizing plate 1 / adhesive layer B / glass plate".

[0170] The simulated image display device refers to a laminate for a high-temperature durability test simulating an image display device in which the image display panel of the image display device is replaced with a glass plate.

[0171] (Manufacture of analog image display devices (2) to (7) with front panels)

[0172] Simulated image display devices (2) to (7) with a front plate were produced in the same manner except that the optical layered body 1 of the simulated image display device (1) with a front plate was replaced with the optical layered bodies 2 to 7.

[0173] (Preparation of Samples for Orthogonal Transmittance Measurement)

[0174] Using an adhesive sheet having PET films with a release agent on both sides of the adhesive layer, one of the PET films with a release agent was peeled off to expose the adhesive layer. Next, the adhesive layer was bonded to the film F2 of the polarizing plate 1 prepared above, thereby producing a laminate R for measuring the cross transmittance of the evaluation sample. The resulting laminate R had a layer structure of "polarizing plate 1 / adhesive layer / PET film with a release agent."

[0175] The obtained laminate R was cut into a size of 90 mm×100 mm so that the absorption axis was parallel to the short side, thereby preparing a sample for orthogonal transmittance measurement.

[0176] [Evaluation of initial optical properties]

[0177] The single-unit transmittance of the analog image display devices (1) to (7) with front panels obtained above was measured using a spectrophotometer / colorimeter (CM-3700A, manufactured by Konica Minolta, Inc.). The obtained single-unit transmittance was corrected for visibility using a 2-degree field of view (illuminant C) in accordance with JIS Z 8701:1999 "Methods of indicating color - XYZ colorimetric system and X10Y10Z10 colorimetric system" to obtain the visibility-corrected single-unit transmittance.

[0178] The PET film with a release agent of the laminate R was peeled off and removed, thereby exposing the adhesive layer. The adhesive layer of the laminate R was bonded to the glass plate on the side of the simulated image display device (1) with the front panel to which the film F2 was laminated via the adhesive layer B, thereby obtaining an evaluation sample (B1). The simulated image display device (1) and the laminate R were bonded so that the polarizing plate of the sample for measuring the orthogonal transmittance formed a crossed Nicol prism relative to the polarizing plate of the simulated image display device (1). The evaluation sample (B1) had a layer structure of "glass plate / adhesive layer / film F3 (acrylic resin film) / adhesive layer A / polarizing plate 1 / adhesive layer B / glass plate / adhesive layer / polarizing plate 1".

[0179] Furthermore, evaluation samples (B2) to (B7) were obtained in the same manner as in the evaluation sample (B1), except that the analog image display device (1) with a front panel was replaced with the analog image display devices (2) to (7).

[0180] The cross transmittance of evaluation samples (B1) to (B7) at a wavelength of 700 nm was measured using a spectrophotometer / colorimeter (CM-3700A, manufactured by Konica Minolta, Inc.). The cross transmittance was 0.01% or less.

[0181] [High temperature durability evaluation]

[0182] After the initial optical property evaluation, each evaluation sample was allowed to stand for 670 hours in an environment at a temperature of 105° C. For each evaluation sample after standing, the visibility-corrected single transmittance and the orthogonal transmittance at a wavelength of 700 nm were measured in the same manner as above.

[0183] The difference between the initial and the corrected single transmittance of each evaluation sample after standing at 105°C for 670 hours was evaluated in three levels according to the following criteria: Evaluations A and B indicated that the change in the corrected single transmittance was acceptable.

[0184] A: Visibility correction: Single transmittance change is less than 2.0%

[0185] B: Visibility correction: Single transmittance change is 2.0% or more and less than 3.0%

[0186] C: Visibility correction: Single transmittance change of 3.0% or more

[0187] Table 3 shows the results of the three-stage evaluation of the visibility-corrected single transmittance change and the results of the orthogonal transmittance at a wavelength of 700 nm after the high-temperature durability test.

[0188] [Table 3]

[0189]

[0190] As shown in Table 3, it was confirmed that the changes in the transmittance of the visibility correction agent alone were within acceptable levels, and polyeneization was also suppressed. In particular, in Examples 1 to 3, 5, and 6, in which the urea-containing adhesive composition 1 was used for lamination between the polarizer and the protective film, the changes in the transmittance of the visibility correction agent alone were smaller than in Example 4, in which the urea-free adhesive composition 2 was used.

[0191] As shown in Table 3, in evaluation sample (B7) using optical layered body 7 (polarizing plate) from Comparative Example 1, the cross transmittance at a wavelength of 700 nm increased to 1.50 after the high-temperature durability test. In contrast, in evaluation samples (B1) to (B6) using composite polarizing plates from Examples 1 to 6, the cross transmittance at a wavelength of 700 nm after the high-temperature durability test was 0.13, 0.80, 1.00, 0.13, 0.78, and 0.79, respectively. These results confirm that, in Examples 1 to 6, the increase in cross transmittance at a wavelength of 700 nm under high-temperature conditions was suppressed compared to Comparative Example 1. Furthermore, it was found that the lower the ammonia permeation concentration in the barrier layer, the more the increase in cross transmittance at a wavelength of 700 nm after the high-temperature durability test was suppressed, regardless of the moisture permeability value.

[0192] Description of Reference Numerals

[0193] 10…Composite polarizing plate

[0194] 20…Image display device

[0195] 30…Polarizing plate

[0196] 31…Polarizer

[0197] 32…Lamination layer

[0198] 33…1st protective film

[0199] 34…Second protective film

[0200] 41…adhesive layer

[0201] 42…adhesive layer

[0202] 43…Front lamination layer

[0203] 50…Ammonia barrier

[0204] 60…Image display panel

[0205] 70…Transparent components

Claims

1. A composite polarizing plate comprising a polarizing plate having a polarizer formed by adsorption and orientation of a dichroic dye on a polyvinyl alcohol-based resin film, a first protective film laminated on one surface of the polarizer, and a second protective film laminated on the other surface of the polarizer. An ammonia barrier layer having an ammonia permeation concentration of 500 ppm or less is further laminated on the surface of the first protective film opposite to the polarizer. A pressure-sensitive adhesive layer is further laminated on the surface of the second protective film opposite to the polarizer.

2. The composite polarizing plate according to claim 1, wherein The ammonia gas barrier layer is a layer including at least one selected from the group consisting of a cyclic olefin resin film and an acrylic resin film.

3. The composite polarizing plate according to claim 1 or 2, wherein: The polarizer and the first protective film, and the polarizer and the second protective film are laminated via an adhesive layer, and the adhesive layer contains at least one urea compound selected from the group consisting of urea, urea derivatives, thiourea, and thiourea derivatives.

4. The composite polarizing plate according to claim 1 or 2, wherein: The moisture permeability of the first protective film at a temperature of 40°C and a relative humidity of 90% is 200 g / (m 2 24 hours) or less.

5. The composite polarizing plate according to claim 1 or 2, wherein: The first protective film and the ammonia barrier layer are laminated via a tacky adhesive layer having a thickness of 10 μm or less.

6. An image display device, wherein: The composite polarizing plate according to claim 1 or 2 and an image display panel are laminated. The image display panel is laminated on the surface of the second protective film opposite to the polarizer via the adhesive layer.

Images