Composite polarizing plate and image display device

Abstract

This suppresses the reddening that occurs in polarizing plates. [Solution] The composite polarizing plate 10 comprises a polarizer 31 on which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol-based resin film, a first protective film 33 laminated on one side of the polarizer 31, and a second protective film 34 laminated on the other side of the polarizer 31. The composite polarizing plate 10 further has an ammonia gas blocking layer 50 with an ammonia gas permeation concentration of 500 ppm or less laminated on the side of the first protective film 33 opposite to the polarizer 31. The composite polarizing plate 10 further has an adhesive layer 42 laminated on the side 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 technology]

[0002] As described in Patent Document 1, it is known that a phenomenon called reddening occurs when a polarizing plate is exposed to a high-temperature environment. Reddening is a phenomenon in which the transmittance on the long wavelength side of approximately 700 nm increases, causing the polarizing plate to appear red when arranged in a crossed nicol configuration. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2019-152862 [Overview of the project] [Problems that the invention aims to solve]

[0004] The present invention aims to suppress the occurrence of red discoloration in polarizing plates. The inventors have found a correlation between contact between ammonia gas entering the polarizing plate from the outside and the polarizer, and the occurrence of red discoloration. [Means for solving the problem]

[0005] This invention includes the following inventions. [1] A composite polarizing plate comprising a polarizer having a dichroic dye adsorbed and oriented on a polyvinyl alcohol-based resin film, a first protective film laminated on one side of the polarizer, and a second protective film laminated on the other side of the polarizer, An ammonia gas blocking layer having an ammonia gas permeation concentration of 500 ppm or less is further laminated on the side of the first protective film opposite to the polarizer. A composite polarizing plate in which an adhesive layer is further laminated on the surface of the second protective film opposite to the polarizer.

[0006] [2] The composite polarizing plate according to [1], wherein the ammonia gas blocking layer is a layer containing at least one selected from the group consisting of a cyclic olefin resin film and an acrylic resin film.

[0007] [3] 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 containing at least one urea compound selected from the group consisting of urea, urea derivatives, thiourea, and thiourea derivatives.

[0008] [4] 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.

[0009] [5] The composite polarizing plate according to any one of [1] to [4], wherein the first protective film and the ammonia gas blocking layer are laminated via an adhesive layer having a thickness of 10 μm or less.

[0010] [6] An image display device in which the composite polarizing plate according to any one of [1] to [5] and an image display panel are laminated, An image display device in which the image display panel is laminated on the surface of the second protective film opposite to the polarizer via the adhesive layer.

Advantages of the Invention

[0011] According to the present invention, it is possible to suppress the occurrence of red discoloration in the polarizing plate.

Brief Description of the Drawings

[0012] [Figure 1]FIG. 1 is a schematic cross-sectional view showing a composite polarizing plate including a polarizing plate. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an image display device including a composite polarizing plate.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the composite polarizing plate and the image display device will be described. <Composite Polarizing Plate> As shown in FIG. 1, the composite polarizing plate 10 includes a polarizing plate 30, an ammonia gas blocking layer 50, and an adhesive layer 42. The ammonia gas blocking layer 50 is laminated on the polarizing plate 30 via, for example, an adhesive layer 41. Hereinafter, the ammonia gas blocking layer may be simply referred to as a blocking layer. The adhesive layer 42 is laminated on the surface of the polarizing plate 30 opposite to the surface on which the blocking layer 50 is laminated.

[0014] As will be described later, the composite polarizing plate 10 can be used as the image display device 20 as shown in FIG. 2 by bonding the adhesive layer 42 to the image display panel 60. The composite polarizing plate 10 can be a composite polarizing plate disposed on the viewing side of the image display panel 60. In the composite polarizing plate 10, the side closer to the adhesive layer 42 is referred to as the panel side, and the side closer to the blocking layer 50 is referred to as the viewing side.

[0015] <Polarizing Plate> The polarizing plate 30 includes a polarizer 31. The polarizing plate 30 includes a protective film for protecting the polarizer 31.

[0016] As shown in FIG. 1, the polarizing plate 30 has a first protective film 33 laminated on one surface of the polarizer 31 via a bonding layer 32. As shown in FIG. 1, the polarizing plate 30 has a second protective film 34 laminated on the other surface of the polarizer 31 via a bonding 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 bonded, for example, using a roll laminator.

[0017] <Polarizer> The polarizer is a uniaxially stretched polyvinyl alcohol-based resin film on which a dichroic dye is adsorbed and oriented. As the polyvinyl alcohol-based resin, for example, a saponified 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.

[0018] Examples of polyvinyl acetate resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate with other monomers copolymerizable thereto. Examples of other copolymerizable monomers include unsaturated carboxylic acids, olefins, vinyl ethers, and unsaturated sulfonic acids.

[0019] The degree of polymerization of the polyvinyl alcohol-based resin is preferably 1000 to 10000, and more preferably 1500 to 5000. The polyvinyl alcohol-based resin may not be modified. Examples of modified polyvinyl alcohol-based resins include polyvinyl formal, polyvinyl acetal, and polyvinyl butyral modified with aldehydes.

[0020] Examples of dichroic dyes include iodine and water-soluble dichroic dyes. The thickness of the polarizer is not particularly limited, but is, for example, 1 μm or more, preferably 5 μm or more, and more preferably 8 μm or more. It is also 50 μm or less, and preferably 30 μm or less.

[0021] A known method can be used to manufacture a polarizer. For example, in this manufacturing method, a polyvinyl alcohol-based resin film is used as the base film and subjected to a swelling process, a dyeing process, a crosslinking process, a washing process, and a drying process in order. The swelling process is a process in which the base film is swollen by immersing it in a swelling solution. The dyeing process is a process in which the film after the swelling process is immersed in a dyeing solution containing a dichroic dye to adsorb and orient the dichroic dye onto the film. The crosslinking process is a process in which the film is brought into contact with a crosslinking solution to perform a crosslinking process. Uniaxial stretching can be performed as a stretching process between each process, that is, before or after any one or more of the process processes, or during the process processes.

[0022] The crosslinking process is a treatment process performed for purposes such as water resistance or hue adjustment (complementary color) through crosslinking. The crosslinking process may be performed multiple times. When the crosslinking process is performed multiple times, the crosslinking process may be performed multiple times for the purpose of water resistance through crosslinking, or multiple crosslinking processes may be performed multiple times for the purpose of hue adjustment. However, it is preferable to perform the crosslinking process for water resistance through crosslinking at least once and the crosslinking process for hue adjustment at least once, and it is more preferable to perform the crosslinking process for hue adjustment after the crosslinking process for water resistance through crosslinking.

[0023] In this specification, the expression "at least one" means "one or more" of the desired options. For example, if there are three or more options, the expression "at least one" means "only one option" or "a combination of two or more arbitrary options."

[0024] <Protective film> The protective film is not particularly limited, and various transparent protective films that can be used for polarizing plates can be employed. As materials constituting the protective film, for example, thermoplastic resins 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 polyamides, polyimide resins, polyolefin resins such as polyethylene, polypropylene, and ethylene-propylene copolymers, (meth)acrylic resins, cyclic polyolefin resins having a cyclo or norbornene structure (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. Furthermore, the protective film can utilize a cured layer formed from thermosetting resins such as (meth)acrylic, urethane, acrylic urethane, epoxy, and silicone resins, or UV-curable resins. Among these, cellulose ester resins, polycarbonate resins, (meth)acrylic resins, cyclic polyolefin resins, and polyester resins are preferred.

[0025] On the surface of the protective film where the polarizer is not attached, functional layers such as a hard coat layer, anti-reflective layer, anti-sticking layer, diffusion layer, or anti-glare layer may be provided. These functional layers, such as the hard coat layer, anti-reflective layer, anti-sticking layer, diffusion layer, and anti-glare layer, can be provided on the protective film itself, or they can be provided separately as components distinct from the protective film.

[0026] Either one or both of the surfaces of the protective film to which the polarizer is bonded, and the surface of the polarizer to which the protective film is bonded, may be surface-treated. Examples of surface treatments include corona treatment, plasma treatment, primer treatment, and saponification treatment.

[0027] The thickness of the protective film is not particularly limited, but from the perspective of handling properties in the manufacturing process, it is 1 μm or more, preferably 10 μm or more, more preferably 30 μm or more. Also, from the perspective of thinning the polarizing plate, 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.

[0028] The moisture permeability of the protective film is not particularly limited, but for the first protective film 33 on the visible side of the protective film, the moisture permeability under the environment of a temperature of 40°C and a relative humidity of 90% is, for example, 350 g / (m 2 ·24 h) or less. The above moisture permeability is, for example, 50 g / (m 2 ·24 h) or more. The measurement of the moisture permeability can be carried out in accordance with the moisture permeability test (cup method) of JIS Z0208.

[0029] The above moisture permeability is preferably 50 g / (m 2 ·24 h) or more and 350 g / (m 2 ·24 h) or less, more preferably 80 g / (m 2 ·24 h) or more and 300 g / (m 2 ·24 h) or less, and even more preferably 100 g / (m 2 ·24 h) or more and 200 g / (m 2 ·24 h) or less.

[0030] The ammonia gas permeation concentration of the protective film is not particularly limited, but for the first protective film 33 on the visible side of the protective film, the ammonia gas permeation concentration can be 1000 ppm or less. The ammonia gas permeation concentration of the first protective film 33 may be 800 ppm or less, may be 100 ppm or more, or may be 300 ppm or more. The measurement of the ammonia gas permeation concentration related to the gas permeability of the first protective film 33 can be carried out by the measurement method described below.

[0031] <Laminating layer> The laminating layer 32 may be an adhesive layer or an adhesive agent layer. Preferably, the laminating layer 32 is an adhesive agent layer.

[0032] The adhesive composition used to form the adhesive layer can be any conventionally known adhesive composition with excellent optical transparency, without any particular limitations. For example, adhesive compositions having a base polymer such as acrylic resin, urethane resin, silicone resin, or polyvinyl ether resin can be used. Among these, adhesive compositions using acrylic resin as the base polymer, which have excellent transparency, adhesive strength, re-peelability, weather resistance, and heat resistance, are preferred. The adhesive composition may further contain a crosslinking agent, a silane compound, an antistatic agent, etc.

[0033] Various adhesive compositions suitable for use in polarizing plates can be used as adhesive compositions for forming the adhesive layer. Examples include aqueous adhesive compositions in which a curable adhesive component is dissolved or dispersed 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, and the solid content concentration of the adhesive composition is preferably 0.5 to 20% by mass, and more preferably 1% to 15% by mass.

[0034] When a polyvinyl alcohol-based resin is used as the main component of an adhesive composition, the polyvinyl alcohol-based resin may be a polyvinyl alcohol resin such as partially saponified polyvinyl alcohol or fully saponified polyvinyl alcohol, or a modified polyvinyl alcohol-based resin. Examples of modified polyvinyl alcohol-based resins include carboxyl group-modified polyvinyl alcohol-based resins and acetoacetyl group-modified polyvinyl alcohol-based resins.

[0035] The average degree of polymerization of the polyvinyl alcohol-based resin (preferably acetoacetyl-modified polyvinyl alcohol-based resin) is preferably 100 to 5500, and more preferably 500 to 4500, from the viewpoint of adhesion.

[0036] The degree of saponification of polyvinyl alcohol-based resins (preferably acetoacetyl-modified polyvinyl alcohol-based resins) is typically 80 mol% to 100 mol%, and preferably 85 mol% or more.

[0037] In acetoacetyl-modified polyvinyl alcohol resins, the degree of modification (amount of modification) by acetoacetyl groups is typically 0.1 mol% to 40 mol%, and preferably 0.5 mol% to 20 mol%, from the viewpoint of adhesion.

[0038] Among water-based adhesive compositions, polyvinyl alcohol-based adhesive compositions are preferred, and acetoacetyl-modified polyvinyl alcohol-based adhesive compositions are more preferred. In other words, the bonded layer 32 is preferably a cured layer of a water-based adhesive composition containing a polyvinyl alcohol-based resin.

[0039] Examples of adhesive compositions include the above-mentioned aqueous adhesive compositions, as well as active energy ray curable adhesive compositions such as ultraviolet 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 having a (meth)acryloyl group and compounds having a vinyl group. Examples of compounds having a (meth)acryloyl group include alkyl (meth)acrylates such as chain-like 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. (Meth)acrylate adhesives may 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 may also contain polyfunctional monomers as crosslinking components, such as tripropylene glycol diacrylate, 1,9-nonanediol diacrylate, tricyclodecanedimethanol diacrylate, cyclic trimethylolpropaneformal acrylate, dioxane glycol diacrylate, and EO-modified diglycerin tetraacrylate. Compounds having epoxy groups or oxetanyl groups can also be used as cationic polymerization-curable adhesives. Compounds having epoxy groups are not particularly limited as long as they have at least two epoxy groups in the molecule, and various generally known curable epoxy compounds can be used.

[0040] The above-mentioned active energy ray curable adhesive composition may contain appropriate additives as needed. Examples of 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 trapping agents, antioxidants, tackifiers, fillers, plasticizers, leveling agents, foam inhibitors, antistatic agents, heat stabilizers, hydrolysis stabilizers, and the like.

[0041] The adhesive composition may be applied to either the protective film side, the polarizer side, or both. After bonding, a drying process is performed to form an adhesive layer consisting of the applied and dried layer. After the drying process, ultraviolet light or electron beams may be irradiated as needed.

[0042] The adhesive composition forming the bonding layer 32 may contain a urea compound. The urea compound and other components that the adhesive composition may contain are described below. [Urea compound] The urea compound is, for example, at least one selected from the group consisting of urea, urea derivatives, thiourea, and thiourea derivatives. The urea compound can be used alone or in combination of two or more. Urea compounds include water-soluble and poorly water-soluble types, and both types can be used. When using a poorly water-soluble urea compound in a water-soluble adhesive, it is preferable to devise a dispersion method to prevent haze formation and other issues after the adhesive layer is formed. Urea is preferred as the urea compound.

[0043] (urea derivative) A urea derivative is a compound in which at least one of the four hydrogen atoms of a urea molecule is substituted with a substituent. In this case, there are no particular restrictions on the substituent, but it is preferable that the substituent consists of a carbon atom, a hydrogen atom, and an oxygen atom.

[0044] Specific examples of urea derivatives include monosubstituted ureas such as methylurea, ethylurea, propylurea, butylurea, isobutylurea, N-octadecylurea, 2-hydroxyethylurea, hydroxyurea, acetylurea, allylurea, 2-propynylurea, cyclohexylurea, phenylurea, 3-hydroxyphenylurea, (4-methoxyphenyl)urea, benzylurea, benzoylurea, o-tolylurea, and p-tolylurea.

[0045] Examples of disubstituted ureas 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 (ethyleneurea), and tetrahydro-2-pyrimidinone (propyleneurea).

[0046] Examples of 4-substituted ureas 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.

[0047] (Thiourea derivatives) Thiourea derivatives are compounds in which at least one of the four hydrogen atoms of a thiourea molecule is substituted with a substituent. In this case, there are no particular restrictions on the substituent, but it is preferable that the substituent consists of a carbon atom, a hydrogen atom, and an oxygen atom.

[0048] Specific examples of thiourea derivatives include monosubstituted thioureas 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.

[0049] Examples of disubstituted thioureas 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.

[0050] Examples of 3-substituted thioureas include trimethylthiourea, and examples of 4-substituted thioureas include tetramethylthiourea and 1,1,3,3-tetraethylthiourea. The content of the urea compound in the adhesive composition is preferably within the following ranges. 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 or more and 400 parts by mass or less, more preferably 1 part by mass or more and 200 parts by mass or less, and even more preferably 3 parts by mass or more and 100 parts by mass or less, per 100 parts by mass of the polyvinyl alcohol resin. Adding a urea compound provides an effect of suppressing polyene formation in high-temperature environments, but if the amount of urea compound is less than 0.1 parts by mass per 100 parts by mass of the polyvinyl alcohol resin, the effect may not be sufficient. If the amount of urea compound exceeds 400 parts by mass per 100 parts by mass of the polyvinyl alcohol resin, the urea compound may precipitate, causing problems such as increased haze.

[0051] [Other ingredients] The adhesive composition may contain an organic solvent. Alcohols are preferred as the organic solvent because they are miscible with water, and methanol or ethanol are more preferred among alcohols. The concentration of the organic solvent in the water-based 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 even more preferably 20% by mass or more and 60% by mass or less. A concentration of 10% by mass or more of the organic solvent makes it easier to suppress polyene formation of the PVA resin under high-temperature conditions. Furthermore, a content of 70% by mass or less of the organic solvent can suppress deterioration of the hue. Some of the urea derivatives mentioned above have low solubility in water but sufficient solubility in alcohol. In such cases, it is also a preferred embodiment to dissolve the urea compound in alcohol to prepare an alcohol solution of the urea compound, and then add this alcohol solution to an aqueous PVA solution to prepare the adhesive.

[0052] Water-based adhesive compositions may contain a crosslinking agent. Typically, the crosslinking agent is a compound having at least two functional groups in one molecule that are reactive with the polymer and other components that make up the adhesive. Examples include alkylenediamines; isocyanates; epoxys; aldehydes; amino-formaldehydes such as methylolurea and methylolmelamine; glyoxal; and glyoxal derivatives. The amount of crosslinking agent in the adhesive is usually about 5 to 60 parts by mass per 100 parts by mass of the polymer and other components that make up the adhesive.

[0053] The thickness of the bonding layer 32 is not particularly limited. For example, when using a water-based adhesive composition, it is preferably about 1 to 5000 nm, and more preferably about 10 to 1000 nm. For example, when using an active energy ray-curable adhesive composition, it is preferably about 0.1 to 10 μm, and more preferably about 0.5 to 5 μm. For example, when using an adhesive composition, it is usually preferably about 0.1 to 30 μm, more preferably 3 to 30 μm, and even more preferably 5 to 25 μm.

[0054] <Ammonia gas block layer> The ammonia gas block layer 50 is laminated on the side of the first protective film 33 opposite to the polarizer 31.

[0055] The block layer 50 has an ammonia gas permeation concentration of 500 ppm or less. Preferably, the ammonia gas permeation concentration of the block layer 50 is 220 ppm or less, and more preferably 140 ppm or less. The lower the ammonia gas permeation concentration of the block layer 50, the more effectively the red distortion of the polarizing plate can be suppressed. The ammonia gas permeation concentration related to the gas permeability of the block layer 50 can be measured by the measurement method described later.

[0056] The block layer 50 is not limited in its other configuration, as long as the ammonia gas permeation concentration is within the specified range described above. The block layer 50 may be a film layer such as a triacetylcellulose film, an acrylic resin film, or a cyclic olefin resin film. The triacetylcellulose film may have a hard coat layer. One or both sides of the film may be surface-treated. Examples of surface treatments include corona treatment, plasma treatment, primer treatment, and saponification treatment.

[0057] The block layer 50 may be a single layer or a multilayer structure of two or more layers. For example, if the block layer 50 is composed of two or more films, an adhesive layer interposed between the films may be included in the block layer 50. The adhesive layer may be, for example, similar to the adhesive layer or bonding layer exemplified herein. When the multilayer block layer 50 is composed of films, only one type of film may be used, or two or more types of films may be used in combination.

[0058] The block layer 50 is preferably a layer comprising at least one selected from the group consisting of cyclic olefin resin films and acrylic resin films. The thickness of the block layer 50 is not particularly limited. For example, the thickness of the block layer 50 is 5 μm or more and 100 μm or less, preferably 20 μm or more and 80 μm or less, and more preferably 13 μm or more and 50 μm or less.

[0059] The moisture permeability of block layer 50 is not particularly limited. For example, the moisture permeability of block layer 50 is 2 g / (m³) in an environment with a temperature of 40°C and a relative humidity of 90%. 2 ·24 hours) or more 450g / (m 2 • 24 hours or less, preferably 2 g / (m 2 ·24 hours) or more 350g / (m 2 • 24 hours or less, more preferably 2 g / (m 2 ·24 hours) or more 100g / (m 2 • 24 hours) or less. The moisture permeability of block layer 50 is 5 g / (m 2• 24 hours or longer is also acceptable. Moisture vapor permeability can be measured in accordance with the moisture vapor permeability test (cup method) of JIS Z0208.

[0060] <Adhesive layer> The adhesive layer 41 is in direct contact with, for example, the first protective film 33 and the ammonia gas block layer 50.

[0061] The adhesive layer 41 may be either an adhesive layer or an adhesive layer. The adhesive layer or adhesive layer constituting the adhesive layer 41 can be appropriately selected from those described as the bonding layer 32. The thickness of the adhesive layer 41 is not particularly limited, but is preferably, for example, 0.015 μm or more and 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. Most preferably 3 μm or more and 8 μm or less.

[0062] <Adhesive layer> The adhesive layer 42 is in direct contact with, for example, the second protective film 34. The adhesive layer 42 may also be laminated via another layer that is laminated on the side of the second protective film 34 opposite to the polarizer 31.

[0063] The adhesive composition for forming the adhesive layer 42 can be appropriately selected from those described as the bonding layer 32. The thickness of the adhesive layer 42 is not particularly limited, but is preferably about 1 to 100 μm, and preferably about 2 to 50 μm.

[0064] <Image display device> Figure 2 shows an example of an image display device 20. As shown in Figure 2, the composite polarizing plate 10 can be used in the image display device 20.

[0065] 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 side of the second protective film 34 opposite to the polarizer 31 via an adhesive layer 42.

[0066] Before being bonded to the image display panel 60, the composite polarizing plate 10 may have a film with a release layer laminated on its adhesive layer 42. This film with the release layer is peeled off and removed during the manufacturing of the image display device 20. The adhesive layer 42 exposed by removing the film with the release layer can then be bonded to the image display panel 60. The release layer can be any known release layer, such as a layer formed by coating a base film with a release agent such as a fluorine compound or a silicone compound.

[0067] 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 block layer 50 of the composite polarizing plate 10 via a front bonding layer 43.

[0068] The front bonding layer 43 is, for example, an adhesive layer. The adhesive composition forming the adhesive layer can be appropriately selected from those described as the bonding layer 32. Examples of transparent components 70 include a front transparent plate (window layer) and a touch panel. For the front transparent plate, a transparent plate with appropriate mechanical strength and thickness is used. Such transparent plates may include, for example, transparent resin plates such as acrylic resin or polycarbonate resin, glass plates, or laminates thereof. For the touch panel, various types of touch panels such as resistive, capacitive, optical, and ultrasonic touch panels, as well as glass plates or transparent resin plates equipped with touch sensor functions, may be used.

[0069] The image display panel 60 is not particularly limited and includes, for example, liquid crystal display panels, organic electroluminescent (organic EL) display panels, inorganic electroluminescent (inorganic EL) display panels, plasma display panels, field emission type display panels, etc.

[0070] Applications for image display devices include, for example, televisions, personal computers, mobile devices such as mobile phones and tablet terminals, and automotive applications. Specific examples of automotive applications include car navigation systems, speedometers, touch panels for air conditioning, backup monitors, and rear monitors.

[0071] <Effects of this embodiment> There is a problem where polarizing plates undergo a phenomenon called reddening when exposed to high-temperature environments. Regarding this reddening, the easier it is for ammonia gas from the outside to penetrate the polarizing plate, the more likely this reddening is to occur.

[0072] The composite polarizer and image display device of this embodiment are equipped with an ammonia gas blocking layer on the viewing side of the polarizer, with an ammonia gas permeation concentration of 500 ppm or less. Therefore, it is possible to suppress the penetration of ammonia gas from the outside, i.e., on the viewing side of the polarizer, into the polarizer. This suppresses the occurrence of red distortion. The composite polarizer and image display device of this embodiment are less prone to red distortion of the polarizer even when placed in a high-temperature environment.

[0073] The composite polarizing plate and image display device, which are less prone to reddening even when exposed to high-temperature environments, can be suitably used in applications where they may be exposed to high-temperature environments for extended periods. For example, image display devices for in-vehicle applications such as car navigation systems and backup monitors may be exposed to high-temperature environments for long periods. The composite polarizing plate and image display device of this embodiment can be suitably used in in-vehicle applications.

[0074] In this embodiment, "high temperature environment" means an environment of 100°C or higher, for example, 105°C or higher. Also, "long duration" means 100 hours or longer, for example, 120 hours.

[0075] The source of external ammonia gas is not particularly limited. Examples of external ammonia gas include ammonia gas present in the air, and ammonia gas generated in the storage, transportation, and usage environments of composite polarizing plates and image display devices. [Examples]

[0076] The composite polarizing plate and image display device will be described in more detail below based on the embodiments described. However, the composite polarizing plate and image display device are not limited to the configurations described in the embodiments section.

[0077] <Measurement of moisture permeability of films and film laminates> The moisture permeability of the film and film laminates used in the manufacture of composite polarizing plates 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.

[0078] <Measurement of ammonia gas permeation concentration in films and film laminates> The ammonia gas permeation concentration of the film used in the manufacture of the composite polarizer was measured using the following measurement method. The ammonia gas permeation concentration of the laminated film used in the manufacture of the composite polarizer was measured by replacing the film with the laminated film in the following measurement method.

[0079] A 10% ammonia aqueous solution was placed in a cup conforming to the JIS L1099 moisture permeability test (cup method), and the permeable ammonia gas area was measured at 28.26 cm². 2 The cup was covered with a processed film. Next, the film was secured with an O-ring, and then a wing nut was tightened to fix the cup and ring in place. Then, the cup was inserted into an aluminum-metallized bag (capacity 1 liter), and the opening of the aluminum-metallized bag was sealed with heat seal. After being left for 2 hours at a temperature of 23°C, a gas detection tube manufactured by Gastec Co., Ltd. was inserted into the aluminum-metallized bag, and the ammonia gas concentration inside the bag was measured. The ammonia gas concentration inside the aluminum-metallized bag is the concentration of ammonia gas that permeated through the film and leaked out of the cup.

[0080] (Manufacturing Example 1: Fabrication of a polarizer) A 30 μm thick polyvinyl alcohol-based resin film was immersed in pure water at 21.5°C for 79 seconds (swelling step), and then immersed for 151 seconds in an aqueous solution at 23°C with a mass ratio of potassium iodide / boric acid / water of 2 / 2 / 100 and containing 1.0 mM iodine (dyeing step). Subsequently, the film removed from the aqueous solution was immersed for 76 seconds in an aqueous solution at 68.5°C with a mass ratio of potassium iodide / boric acid / water of 2.5 / 4 / 100 (first crosslinking step). Subsequently, the film removed from the aqueous solution was immersed for 11 seconds in an aqueous solution at 45°C with a mass ratio of potassium iodide / boric acid / zinc chloride / water of 3 / 5.5 / 0.6 / 100 (second crosslinking step, metal ion treatment step). Subsequently, the film extracted from the aqueous solution was immersed in a washing solution (washing step), and the film extracted from the washing solution was dried at 38°C (drying step) to obtain a polarizer with a thickness of 12 μm in which iodine was adsorbed and oriented on polyvinyl alcohol. Stretching was mainly carried out in the dyeing step and the first crosslinking step, and the total stretching ratio was 5.85 times. The thickness of the obtained polarizer was measured using a Nikon Corporation digital micrometer "MH-15M".

[0081] (Manufacturing Example 2: Preparation of Adhesive Composition) 50 g of acetoacetyl-modified polyvinyl alcohol resin (manufactured by Mitsubishi Chemical Corporation: Gosenex Z-410) was dissolved in 950 g of pure water, heated at 90°C for 2 hours, and then cooled to room temperature to obtain an acetoacetyl-modified polyvinyl alcohol resin solution.

[0082] Adhesive composition 1 was prepared by adding maleic acid, a 40% by mass solution of glyoxal, urea, and pure water to the obtained acetoacetyl-modified polyvinyl alcohol resin solution in the amounts shown in Table 1 below. Adhesive composition 2 was prepared by adding maleic acid, a 40% by mass solution of glyoxal, and pure water to the acetoacetyl-modified polyvinyl alcohol resin solution obtained above in the amounts shown in Table 1 below.

[0083] [Table 1]

[0084] <Fabrication of polarizing plates> The following films were prepared. Film F1: Saponified triacetylcellulose film with hard coat layer (Toppan Printing Co., Ltd., product name "40FJCHCN-LMP", triacetylcellulose film thickness: 40 μm, hard coat layer thickness: 7 μm). Moisture permeability is 200 g / m². 2 (After 24 hours), the ammonia gas permeation concentration was 400 ppm. • Film F2: A laminated phase difference film described in International Publication No. 2022 / 158482

[0147] . This laminated phase difference film consists of a liquid crystal layer (first phase difference layer) and a cycloolefin polymer film (second phase difference layer). • Film F3: Acrylic resin film (manufactured by Toyo Kohan Co., Ltd.: product name "HX-40NE"). Thickness 40 μm. Moisture permeability 60 g / m². 2 (After 24 hours), the ammonia gas permeation concentration was 10 ppm. • Film F4: Cycloolefin polymer film (thickness 23 μm, manufactured by Nippon Zeon Co., Ltd.). Moisture permeability is 6 g / m². 2 (After 24 hours), the ammonia gas permeation concentration was 220 ppm.

[0085] (Manufacturing Example 3: Fabrication of Polarizing Plates 1 and 2) Film F1, prepared in Manufacturing Example 2, was laminated to one side of the polarizer manufactured in Manufacturing Example 1 via adhesive composition 1, with the side without the hard coat layer facing the polarizer. Film F2, prepared in Manufacturing Example 2, was laminated to the other side of the polarizer via adhesive composition 1, with the first phase difference layer facing the polarizer, and the slow layer axis of the second phase difference layer parallel to the absorption axis of the polarizer. The films were then bonded using a roll laminating machine. The films were then dried at 75°C for 8 minutes to obtain a polarizing plate 1. Films F1 and F2 laminated to the polarizer correspond to protective films for the polarizer. The adhesive layers, each made of adhesive composition 1, had a thickness of 80 nm after drying.

[0086] Furthermore, polarizing plate 2 was prepared in the same manner as polarizing plate 1, except that adhesive composition 1 was replaced with adhesive composition 2. The adhesive layer made of adhesive composition 2 had a thickness of 80 nm after drying.

[0087] (Manufacturing Example 4: Preparation of an adhesive sheet with an adhesive layer) • Adhesive sheet A: A sheet comprising a commercially available sheet-type acrylic adhesive layer A with 38 μm polyethylene terephthalate (PET) film with release agent on both sides. The thickness of adhesive layer A is 5 μm, and its storage modulus is 0.14 MPa. • Adhesive sheet B: A sheet comprising a commercially available sheet-type acrylic adhesive layer B with a 38 μm PET film with a release agent on both sides. The thickness of adhesive layer B is 25 μm, and its storage modulus is 0.06 MPa.

[0088] (Example 1: Fabrication of optical laminate 1) One side of the PET film with a release agent on adhesive sheet A was peeled off to expose adhesive layer A, which was then laminated to the film F1 side of the polarizing plate 1 prepared above, i.e., the side where the hard coat layer was exposed. Next, the other side of the PET film with a release agent on adhesive sheet A was peeled off to expose adhesive layer A, and film F3 (acrylic resin film) was then laminated to it. In this way, film F3 (acrylic resin film) was laminated to the film F1 side of the polarizing plate 1 via adhesive layer A. Subsequently, adhesive layer B, which was peeled off one side of the PET film with a release agent on adhesive sheet B to expose it, was laminated to the film F2 side of the polarizing plate 1, thereby creating an optical laminate 1 in which adhesive layer B was laminated to the film F2 side of the polarizing plate 1. The resulting optical laminate 1 has 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 notation of the layer configurations described above and below, " / " indicates that the layers described before and after the " / " are in direct contact. The film laminated on the side opposite the polarizer in film F1, which is the first protective film of polarizing plate 1, corresponds to the ammonia gas block layer. That is, film F3 corresponds to the ammonia gas block layer. The laminates obtained by peeling and removing the PET film with release agent from optical laminate 1 and optical laminates 2 to 6 below correspond to composite polarizing plates.

[0089] (Example 2: Fabrication of optical laminate 2) Optical laminate 2 was fabricated in the same manner as optical laminate 1, except that film F3 was replaced with film F4 and corona treatment was performed on the bonding surface of film F4. In optical laminate 2, film F4 is the ammonia gas block layer.

[0090] (Example 3: Fabrication of optical laminate 3) Optical laminate 3 was fabricated in the same manner as optical laminate 1, except that film F3 was replaced with film F1, and the side of film F1 without a hard coat layer was used as the bonding surface with adhesive layer A. In optical laminate 3, film F1 is the ammonia gas block layer.

[0091] (Example 4: Fabrication of optical laminate 4) Optical laminate 4 was fabricated in the same manner as optical laminate 1, except that polarizer plate 1 was replaced with polarizer plate 2. In optical laminate 4, film F3 is the ammonia gas block layer.

[0092] (Preparation of laminated film F4) Two layers of the above film F4 were bonded together via adhesive sheet A to prepare a two-layer laminate (film F4*2). Three layers of the above film F4 were bonded together via adhesive sheet A to prepare a three-layer laminate (film F4*3). When bonding the films F4 together with adhesive sheet A, the surface of film F4 that bonded to adhesive sheet A was subjected to corona treatment. In the two-layer laminate (film F4*2), the moisture permeability was 5 g / m². 2 • After 24 hours, the ammonia gas permeation concentration was 100 ppm. In the 3-layer laminate (film F4*3), the moisture permeability was 3 g / (m²). 2 (After 24 hours), the ammonia gas permeation concentration was 40 ppm.

[0093] (Example 5: Fabrication of optical laminate 5) An optical laminate 5 was fabricated in the same manner as described above, except that the film F3 of the optical laminate 1 was replaced with a two-layer laminate (film F4*2), and corona treatment was performed on the bonding surface with the polarizing plate 1 of the two-layer laminate (film F4*2). In the optical laminate 5, the multilayer two-layer laminate (film F4*2) is the ammonia gas block layer.

[0094] (Example 6: Fabrication of optical laminate 6) An optical laminate 6 was fabricated in the same manner as described above, except that the film F3 of the optical laminate 1 was replaced with a three-layer laminate (film F4*3), and corona treatment was performed on the bonding surface with the polarizing plate 1 of the three-layer laminate (film F4*3). In the optical laminate 6, the three-layer laminate (film F4*3) is the ammonia gas block layer.

[0095] (Comparative Example 1: Fabrication of Optical Laminate 7) An optical laminate 7 was fabricated by peeling off one of the release agent-coated PET films on adhesive sheet B to expose the adhesive layer B, and then laminating the exposed adhesive layer B onto the film F2 of the polarizing plate 1 prepared above. The resulting optical laminate has a layer structure of "polarizing plate 1 / adhesive layer B / release agent-coated PET film".

[0096] <Ammonia gas exposure test> In optical laminate 1, the material was cut to a size of 40 mm x 35 mm so that the absorption axis was parallel to the longer side. Next, the PET film with the release agent was peeled off and a 50 mm x 40 mm alkali-free glass (Corning "EAGLE XG") was bonded to the surface of adhesive layer B to obtain evaluation laminate with glass plate (1). The obtained evaluation laminate with glass plate (1) has the layer structure of "film F3 (acrylic resin film) / adhesive layer A / polarizing plate 1 / adhesive layer B / glass plate". Evaluation laminates with glass plates (2) to (7) were obtained in the same manner as above, except that optical laminates 2 to 7 were used instead of optical laminate 1.

[0097] For the laminated structures with glass plates (1) to (7), the temperature was 50°C and the pressure was 5 kgf / cm². 2 Evaluation samples (A1) to (A7) were prepared by autoclaving at (490.3 kPa) for 15 minutes.

[0098] The orthogonal transmittance at a wavelength of 700 nm was measured for evaluation samples (A1) to (A7) using a spectrophotometer with an integrating sphere (V-7100, manufactured by JASCO Corporation). The orthogonal transmittance was 0.01% or less for all samples.

[0099] Next, each evaluation sample and 0.07 ml of 10% ammonia aqueous solution were placed in a 500 ml sealed plastic bottle and immersed in a 60°C environment for 120 hours. The evaluation samples were removed, and the orthogonal 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 in this test was 20,000 ppm.

[0100] [Table 2]

[0101] As shown in Table 2, we confirmed that the lower the ammonia gas permeation concentration in the block layer, the more suppressed the increase in orthogonal transmittance at a wavelength of 700 nm after exposure of the evaluation sample to ammonia gas. In other words, we confirmed that the easier it is for ammonia gas to penetrate, the more likely red discoloration is to occur.

[0102] <High Temperature Durability Test> (Manufacturing of a pseudo-image display device with a front panel (1)) In the optical laminate 1 obtained in Example 1, it was cut to a size of 90 mm x 100 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 100 mm x 100 mm alkali-free glass (Corning's "EAGLE XG") was bonded to the surface of the adhesive layer B to obtain a laminate with a glass plate (1).

[0103] Next, a 100mm x 100mm alkali-free glass (Corning's "EAGLE XG") was bonded to the side of the laminated body (1) without the glass plate, via a 250μm thick adhesive layer, at a temperature of 50°C and a pressure of 5kgf / cm². 2 A pseudo-image display device (1) with a front panel was fabricated by autoclaving at (490.3 kPa) for 15 minutes. The resulting pseudo-image display device (1) with a front panel has the following layer structure: "glass plate / adhesive layer / film F3 (acrylic resin film) / adhesive layer A / polarizing plate 1 / adhesive layer B / glass plate".

[0104] Furthermore, a pseudo-image display device refers to a laminated structure used for high-temperature durability testing that mimics an image display device by replacing the image display panel of an image display device with a glass plate. (Manufacturing of pseudo-image display devices with front panels (2) to (7)) Pseudo-image display devices with front panels (2) to (7) were manufactured in the same manner as the pseudo-image display device with front panel (1), except that optical laminate 1 was replaced with optical laminates 2 to 7.

[0105] (Preparation of samples for orthogonal transmittance measurement) An adhesive sheet with a release agent-coated PET film on both sides of the adhesive layer was used, and the adhesive layer was exposed by peeling off one of the release agent-coated PET films. Next, the adhesive layer was laminated to the film F2 of the polarizing plate 1 prepared above to create a laminate R to be used to measure the orthogonal transmittance of the evaluation sample. The resulting laminate R has a layer structure of "polarizing plate 1 / adhesive layer / release agent-coated PET film".

[0106] The resulting laminate R was cut to a size of 90 mm x 100 mm so that the absorption axis was parallel to the shorter side, and a sample for orthogonal transmittance measurement was prepared. [Evaluation of initial optical properties] The pseudo-image display devices with front panels (1) to (7) obtained above were subjected to individual transmittance measurements using a spectrophotometer / colorimeter (Konica Minolta, Inc. "CM-3700A"). The obtained individual transmittances were then corrected for luminous sensitivity using a 2-degree field of view (C light source) according to JIS Z 8701:1999 "Methods of color representation - XYZ color system and X10Y10Z10 color system" to determine the luminous sensitivity corrected individual transmittance.

[0107] The adhesive layer was exposed by peeling and removing the PET film with release agent from the laminate R. An evaluation sample (B1) was obtained by bonding the adhesive layer of the laminate R to the glass plate on the side where the film F2 of the pseudo-image display device (1) with a front plate is laminated via adhesive layer B. The bonding of the pseudo-image display device (1) and the laminate R was performed so that the polarizer of the sample for orthogonal transmittance measurement was crossed with respect to the polarizer of the pseudo-image display device (1). The evaluation sample (B1) has the layer configuration of "glass plate / adhesive layer / film F3 (acrylic resin film) / adhesive layer A / polarizer 1 / adhesive layer B / glass plate / adhesive layer / polarizer 1".

[0108] Furthermore, evaluation samples (B2) to (B7) were obtained in the same manner as evaluation sample (B1), except that the pseudo-image display device with a front panel (1) was replaced with pseudo-image display devices (2) to (7). For evaluation samples (B1) to (B7), the orthogonal transmittance at a wavelength of 700 nm was measured using a spectrophotometer / colorimeter (Konica Minolta, Inc. "CM-3700A"). The orthogonal transmittance was 0.01% or less for all samples.

[0109] [High-temperature durability evaluation] After the initial optical property evaluation described above, each evaluation sample was left to stand for 670 hours in an environment at a temperature of 105°C. For each evaluation sample after standing, the luminous efficiency-corrected single-unit transmittance and the orthogonal transmittance at a wavelength of 700 nm were measured in the same manner as described above.

[0110] Each evaluation sample was evaluated in three stages according to the following criteria, based on the difference in luminous efficiency-corrected single-unit transmittance between the initial state and the state after being left standing for 670 hours in an environment at a temperature of 105°C. Both evaluations A and B indicate that the change in luminous efficiency-corrected single-unit transmittance is at an acceptable level. • A: Transmittance change with luminous sensitivity correction alone is less than 2.0% • B: Transmittance change due to luminous sensitivity correction alone is 2.0% or more, but less than 3.0%. • C: Transmittance change of 3.0% or more with luminous sensitivity correction alone Table 3 shows the results of a three-stage evaluation of the change in transmittance due to luminous efficiency correction, and the results of the orthogonal transmittance at a wavelength of 700 nm after the high-temperature durability test.

[0111] [Table 3]

[0112] As shown in Table 3, the changes in the luminous efficiency correction unit transmittance were all within acceptable levels, and polyene formation was confirmed to be suppressed. In particular, in Examples 1-3, 5, and 6, which used adhesive composition 1 containing urea for bonding the polarizer and protective film, the change in luminous efficiency correction unit transmittance was smaller compared to Example 4, which used adhesive composition 2 that did not contain urea.

[0113] As shown in Table 3, in the evaluation sample (B7) using the optical laminate 7 (polarizer) of Comparative Example 1, the orthogonal transmittance at a wavelength of 700 nm increased to 1.50 after the high-temperature durability test. In contrast, in the evaluation samples (B1) to (B6) using the composite polarizers of Examples 1 to 6, the orthogonal 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. From these results, it was confirmed that in all of Examples 1 to 6, the increase in orthogonal transmittance at a wavelength of 700 nm under high-temperature conditions was suppressed compared to Comparative Example 1. Furthermore, it can be seen that the increase in orthogonal transmittance at a wavelength of 700 nm after the high-temperature durability test tends to be suppressed as the ammonia gas permeation concentration of the block layer decreases, regardless of the moisture permeability value. [Explanation of symbols]

[0114] 10…Composite polarizing plate 20…Image display device 30…Polarizing plate 31… Polarizer 32…Laminated layer 33…First protective film 34…Second protective film 41…Adhesive layer 42…Adhesive layer 43…Front lamination layer 50…Ammonia gas block layer 60…Image display panel 70…Transparent material

Claims

1. A composite polarizing plate comprising a polarizer having a dichroic dye adsorbed and oriented on a polyvinyl alcohol-based resin film, a first protective film laminated on one side of the polarizer, and a second protective film laminated on the other side of the polarizer, An ammonia gas blocking layer having an ammonia gas permeation concentration of 500 ppm or less is further laminated on the side of the first protective film opposite to the polarizer. A composite polarizing plate in which an adhesive layer is further laminated on the side of the second protective film opposite to the polarizer.

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

3. The composite polarizer 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 containing at least one urea compound selected from the group consisting of urea, urea derivatives, thiourea, and thiourea derivatives.

4. The moisture permeability of the first protective film at a temperature of 40°C and a relative humidity of 90% is 200 g / m². ２ A composite polarizing plate according to claim 1 or 2, wherein the time is 24 hours or less.

5. The composite polarizing plate according to claim 1 or 2, wherein the first protective film and the ammonia gas block layer are laminated via an adhesive layer with a thickness of 10 μm or less.

6. An image display device comprising a composite polarizing plate according to claim 1 or 2 and an image display panel laminated together, An image display device in which the image display panel is laminated on the side of the second protective film opposite to the polarizer via the adhesive layer.

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